268 results on '"Tai C. Chen"'
Search Results
2. Alterations in Lipids and Adipocyte Hormones in Female-to-Male Transsexuals
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Prakash Chandra, Sukhdeep S. Basra, Tai C. Chen, and Vin Tangpricha
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Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Testosterone therapy in men and women results in decreased high-density lipoprotein cholesterol (HDL) and increased low-density lipoprotein cholesterol (LDL). We sought to determine whether testosterone therapy has this same effect on lipid parameters and adipocyte hormones in female-to-male (FTM) transsexuals. Twelve FTM transsexuals provided a fasting lipid profile including serum total cholesterol, HDL, LDL, and triglycerides prior to and after 1 year of testosterone therapy (testosterone enanthate or cypionate 50–125 mg IM every two weeks). Subjects experienced a significant decrease in mean serum HDL (52±11 to 40±7 mg/dL) (P
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- 2010
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3. MART-10, a 1α,25(OH)2D3 Analog, Potently Represses Metastasis of ER+ Breast Cancer Cells with VEGF-A Overexpression
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Masashi Takano, Sheng-Fong Kuo, Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Jong-Hwei S. Pang, Li-Wei Chen, Kun-Chun Chiang, Tai C. Chen, Ta-Sen Yeh, and Ming-Huang Chen
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Cancer Research ,030219 obstetrics & reproductive medicine ,Angiogenesis ,Chemistry ,Cell migration ,General Medicine ,medicine.disease ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Oncology ,MCF-7 ,Neuropilin 1 ,Cancer cell ,medicine ,Cancer research ,030212 general & internal medicine ,Autocrine signalling - Abstract
Background Breast cancer ranks second in the list of cancer-related deaths for women. Even under multidisciplinary treatment, 25-50% of patients with breast cancer still ultimately develop metastasis, leading to poor prognosis. In addition to inducing angiogenesis, vascular endothelial growth factor-A (VEGF-A) is believed to directly increase cancer cell metastatic potential and overexpression of VEGF-A is associated with higher invasiveness of breast cancer. 1α,25(OH)2D3, the active form of vitamin D, and its analogs have been widely applied as anticancer agents in the past. Material and methods Western blot, migration and invasion assays, enzyme-linked immunosorbent assay, and immunofluorescent stain were applied in this study. Result VEGF-A increased cell migration and invasion in estrogen receptor-positive (ER+) breast cancer MCF-7 cells. VEGF-A induced an autocrine loop in MCF-7 cells as VEGF-A treatment increased both VEGF-A expression and secretion. The expression of VEGF receptor type 2 (VEGFR2) and neuropilin 1 was also up-regulated by VEGF-A in MCF-7 cells. In addition, F-actin synthesis and LIM domain kinase 1 (LIMK-1) phosphorylation were increased by VEGF-A. VEGF-A also increased β-catenin expression and nuclear translocation of both β-catenin and nuclear factor-ĸB (NF-ĸB), indicating increased β-catenin and NF-ĸB activity. 1α,25(OH)2D3 and MART-10, an analog of 1α,25(OH)2D3, effectively repressed VEGF-A-induced MCF-7 cell migration and invasion and other VEGF-A-induced effects on MCF-7 cells, with MART-10 being more potent than 1α,25(OH)2D3 Conclusion: MART-10 can be deemed as a promising agent for prevention and treatment of metastasis of ER+ breast cancer with VEGF-A overexpression.
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- 2018
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4. ASSESSMENT OF SERUM 25-HYDROXYVITAMIN D CONCENTRATIONS IN TWO COLLECTIONS OF CAPTIVE GORILLAS (GORILLA GORILLA GORILLA)
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Eric J. Baitchman, Michael F. Tlusty, Tai C. Chen, Michael F. Holick, Hayley Murphy, and Susan L. Bartlett
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Male ,Vitamin ,040301 veterinary sciences ,Gorilla ,030204 cardiovascular system & hematology ,0403 veterinary science ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Animal science ,biology.animal ,Vitamin D and neurology ,Animals ,Primate ,Vitamin D ,Serum 25 hydroxyvitamin d ,Management practices ,Gorilla gorilla ,General Veterinary ,biology ,Ecology ,04 agricultural and veterinary sciences ,General Medicine ,Animal husbandry ,Housing, Animal ,chemistry ,Animals, Zoo ,Female ,Animal Science and Zoology ,Cholecalciferol - Abstract
Serum 25-hydroxyvitamin D concentrations were assessed in subadult to adult captive lowland gorillas (Gorilla gorilla gorilla) (n = 26) at two institutions with different husbandry and management practices. Serum 25-hydroxyvitamin D (25[OH]D) concentrations for gorillas managed predominantly indoors was low (14.2 ± 5.9 ng/ml), despite consuming commercial biscuits fortified with vitamin D3. Concentrations of 25(OH)D in gorillas with near daily outdoor access were significantly higher than gorillas managed indoors, although many individuals still had serum values below concentrations recommended for adult humans. Consideration should be given to assessing 25(OH)D concentrations in all captive gorillas and providing specific supplementation, particularly to juveniles without access to direct sunlight.
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- 2017
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5. HEALTH AND NUTRITIONAL ASSESSMENT OF FREE-RANGING EASTERN INDIGO SNAKES (DRYMARCHON COUPERI) IN GEORGIA, UNITED STATES
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Natalie L. Hyslop, Mark A. Mitchell, Terry M. Norton, Carolyn Cray, Stephen J. Divers, Marcie Oliva, Ellen S. Dierenfeld, Tai C. Chen, Nancy L. Stedman, Lance A. Durden, Samantha E. J. Gibbs, Robert H. Poppenga, Dirk J. Stevenson, and S. Emmanuelle Knafo
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Blood Glucose ,Male ,0106 biological sciences ,Veterinary medicine ,Georgia ,040301 veterinary sciences ,Endangered species ,Nutritional Status ,Animals, Wild ,Biology ,010603 evolutionary biology ,01 natural sciences ,0403 veterinary science ,Electrolytes ,Reference Values ,Animals ,Aspartate Aminotransferases ,Animal nutrition ,General Veterinary ,Alanine Transaminase ,Snakes ,04 agricultural and veterinary sciences ,General Medicine ,Pesticide ,Total dissolved solids ,Uric Acid ,Cross-Sectional Studies ,Fat-Soluble Vitamin ,Parasitology ,Blood chemistry ,Threatened species ,Female ,Serum Globulins ,Animal Science and Zoology ,Animal Distribution - Abstract
Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, United States. Health and nutritional assessments performed included hematology, serum biochemistry, fat-soluble vitamins, heavy metals, pesticide contaminants, parasitology, and surveys of other pathogens. Significant differences in total solids, packed cell volume, glucose, blood urea nitrogen, albumin : globulin ratio, amylase, triglycerides, and bile acids between males and females were observed. Additionally, there was a significant difference between liver and kidney concentrations for vitamins A and E. As previously noted in captive EIS, total Ca was elevated in comparison to concentrations reported in other snake species. Parasitism was a common finding in sampled EIS, but the overall health status of this free-ranging population appeared good. A winter-time dermatitis was found in most snakes, which resolved in the summer months. This study represents the first health and nutritional assessment of free-ranging EIS, and provides needed data to guide monitoring and conservation efforts.
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- 2016
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6. MART-10, a 1α,25(OH)
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Kun-Chun, Chiang, Chun-Nan, Yeh, Ta-Sen, Yeh, Horng-Heng, Juang, Li-Wei, Chen, Sheng-Fong, Kuo, Ming-Huang, Chen, Tai C, Chen, Masashi, Takano, Atsushi, Kittaka, and Jong-Hwei S, Pang
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Vascular Endothelial Growth Factor A ,Blotting, Western ,Fluorescent Antibody Technique ,Lim Kinases ,Antineoplastic Agents ,Breast Neoplasms ,Enzyme-Linked Immunosorbent Assay ,Vascular Endothelial Growth Factor Receptor-2 ,Neuropilin-1 ,Receptors, Estrogen ,MCF-7 Cells ,Humans ,Female ,Neoplasm Metastasis ,Cholecalciferol - Abstract
Breast cancer ranks second in the list of cancer-related deaths for women. Even under multidisciplinary treatment, 25-50% of patients with breast cancer still ultimately develop metastasis, leading to poor prognosis. In addition to inducing angiogenesis, vascular endothelial growth factor-A (VEGF-A) is believed to directly increase cancer cell metastatic potential and overexpression of VEGF-A is associated with higher invasiveness of breast cancer. 1α,25(OH)Western blot, migration and invasion assays, enzyme-linked immunosorbent assay, and immunofluorescent stain were applied in this study.VEGF-A increased cell migration and invasion in estrogen receptor-positive (ER+) breast cancer MCF-7 cells. VEGF-A induced an autocrine loop in MCF-7 cells as VEGF-A treatment increased both VEGF-A expression and secretion. The expression of VEGF receptor type 2 (VEGFR2) and neuropilin 1 was also up-regulated by VEGF-A in MCF-7 cells. In addition, F-actin synthesis and LIM domain kinase 1 (LIMK-1) phosphorylation were increased by VEGF-A. VEGF-A also increased β-catenin expression and nuclear translocation of both β-catenin and nuclear factor-ĸB (NF-ĸB), indicating increased β-catenin and NF-ĸB activity. 1α,25(OH)
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- 2018
7. MART-10, the vitamin D analog, is a potent drug to inhibit anaplastic thyroid cancer cell metastatic potential
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Masashi Takano, Kun-Chun Chiang, Chih-Hung Chen, Chun-Nan Yeh, Sheng-Fong Kuo, Atsushi Kittaka, Horng-Heng Juang, Li-Wei Chen, Shu-Fu Lin, Jen-Der Lin, Tai C. Chen, Jong-Hwei S. Pang, and Soh-Ching Ng
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Cancer Research ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Cell ,Antineoplastic Agents ,Metastasis ,chemistry.chemical_compound ,Downregulation and upregulation ,Cell Movement ,Cell Line, Tumor ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Thyroid Neoplasms ,Epithelial–mesenchymal transition ,Neoplasm Metastasis ,Anaplastic thyroid cancer ,Cholecalciferol ,business.industry ,Cancer ,medicine.disease ,Actins ,medicine.anatomical_structure ,Endocrinology ,Matrix Metalloproteinase 9 ,Oncology ,chemistry ,Cancer research ,Matrix Metalloproteinase 2 ,Drug Screening Assays, Antitumor ,business - Abstract
The survival rate of anaplastic thyroid cancer (ATC) is still very poor due to its fast growth and high metastatic potential. Currently, no effective treatment is available. The active form of vitamin D3, 1α,25(OH)2D3, has been shown to have a anti-metastatic effect in pre-clinical studies, however induction of hypercalcemia hampered its clinical application. The new class of less-calcemic vitamin D analog, 19-nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10), is much more potent than 1α,25(OH)2D3 to repress cancer growth and metastasis in a variety of cancers. In this study, we demonstrated that both 1α,25(OH)2D3 and MART-10 could effectively inhibit the migration and invasion of ATC cells, 8305C and 8505C, with MART-10 much more potent than 1α,25(OH)2D3. The anti-metastatic effect of 1α,25(OH)2D3 and MART-10 on ATC cells is mediated by reversal of cadherin switch (upregulation of E-cadherin and downregulation of N-cadherin), which led to the attenuation of EMT process, and decrease of F-actin formation. We further showed that the expressions of Slug, the EMT-related transcriptional factor, and MMP-9 were inhibited by 1α,25(OH)2D3 and MART-10 in 8505C cells, but not in 8303C cells. Since metastasis is the important cause of ATC-related death, our results strongly encourage the further in vivo study of MART-10 application against ATC.
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- 2015
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8. 19-Norvitamin D analogs for breast cancer therapy
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Tai C. Chen, Atsushi Kittaka, and Yotaro Matsumoto
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medicine.medical_specialty ,Calcitriol ,Physiology ,Breast Neoplasms ,Calcitriol receptor ,chemistry.chemical_compound ,Breast cancer ,CYP24A1 ,Cell Line, Tumor ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Humans ,Cholecalciferol ,Pharmacology ,Chemistry ,Cancer ,General Medicine ,medicine.disease ,Endocrinology ,Cancer cell ,Cancer research ,Receptors, Calcitriol ,Female ,Liver cancer ,medicine.drug - Abstract
The active form of vitamin D3, 1α,25-dihydroxyvitamin D3(1α,25(OH)2D3or calcitriol), is known to inhibit the proliferation and invasiveness of many types of cancer cells, including breast, colon, pancreatic, prostate, and liver cancer cells. These findings support the use of 1α,25(OH)2D3for the treatment of these types of cancer. However, 1α,25(OH)2D3can cause hypercalcemia, so analogs of 1α,25(OH)2D3that are less calcemic but exhibit more potent anti-tumor activity would be good candidates as therapeutic agents. Therefore, a series of 19-norvitamin D analogs, in which the methylidene group on C19 is replaced with 2 hydrogen atoms, have been synthesized by several laboratories. In our laboratory, we have designed and synthesized a series of 2α-functional group substituted 19-norvitamin D3analogs and examined their anti-proliferative activity. Among them, 2α- and 2β-(3-hydroxypropyl)-1α,25-dihydroxy-19-norvitamin D3(MART-10 and MART-11) were found to be the most promising. Here, we review the rationale and approaches for the synthesis of different 19-norvitamin D analogs, and the pre-clinical studies using these analogs in breast cancer cells, in particular, we chose MART-10 for its potential application to the prevention and treatment of breast cancer.
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- 2015
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9. Synthesis and metabolic studies of 1α,2α,25-, 1α,4α,25- and 1α,4β,25-trihydroxyvitamin D3
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G. Satyanarayana Reddy, Daisuke Sawada, Masashi Takano, Miyu Nishikawa, Tai C. Chen, Kaori Yasuda, Kyohei Horie, Atsushi Kittaka, Ken Ichiro Takagi, Akiko Takeuchi, and Toshiyuki Sakaki
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Vitamin ,Glucuronate ,Stereochemistry ,Endocrinology, Diabetes and Metabolism ,Metabolite ,Clinical Biochemistry ,Biochemistry ,Calcitriol receptor ,chemistry.chemical_compound ,Endocrinology ,Calcitriol ,CYP24A1 ,Vitamin D and neurology ,Animals ,Humans ,Molecular Biology ,Molecular Structure ,Stereoisomerism ,Biological activity ,Vitamins ,Cell Biology ,Metabolism ,Rats ,chemistry ,Molecular Medicine - Abstract
Three different A-ring perhydroxylated trihydroxyvitamin D3 metabolites were synthesized from their appropriate A-ring precursors and CD-ring for their potential therapeutic applications. We first chemically synthesized 1α,2α,25-trihydroxyvitamin D3 [1α,2α,25(OH)3D3] to study its VDR binding affinity because this metabolite is a product of recombinant human CYP3A4 catalysis when 2α-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3 (O2C3), a more potent vitamin D receptor (VDR) binder than 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], is used as the substrate. We found that this metabolite retained 27.3% of the VDR binding affinity compared to 1α,25(OH)2D3. The kcat/Km value of CYP24A1 for 1α,2α,25(OH)3D3 is 60% of that for 1α,25(OH)2D3. Since the biological activity and the metabolic fate of a naturally occurring C4-hydroxylated vitamin D2 metabolite found in the serum of rats treated with pharmacological doses of vitamin D2 have never been described, we next synthesized 1α,4α,25-trihydroxyvitamin D3 and its diastereoisomer, 1α,4β,25-trihydroxyvitamin D3, to study their metabolism and biological activities. Both 4-hydroxylated isomers showed weaker VDR binding affinity than 1α,25(OH)2D3. Although either 4-hydroxylated isomer can be metabolized by CYP24A1 almost at the same level as 1α,25(OH)2D3, their metabolic patterns catalyzed by uridine 5'-diphosphoglucuronosyltransferase (UGT) are different; only the 4α-hydroxylated analog can be metabolized by UGT to produce a glucuronate conjugate. The results provide important information for the synthesis of new novel chemotherapeutic vitamin D analogs which would be less subjective to degradation and therefore more bioavailable than 1α,25(OH)2D3. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.
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- 2015
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10. 1α,25(OH)2D3 Analog, MART-10, Inhibits Neuroendocrine Tumor Cell Metastasis After VEGF-A Stimulation
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Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Tai C. Chen, Kun-Chun Chiang, Jong-Hwei S. Pang, Jun-Te Hsu, Po-Jen Hsieh, Ta-Sen Yeh, Sheng-Fong Kuo, Li-Wei Chen, and Masashi Takano
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0301 basic medicine ,Cancer Research ,biology ,medicine.diagnostic_test ,Angiogenesis ,Chemistry ,Cell ,Cell migration ,General Medicine ,Neuroendocrine tumors ,medicine.disease ,Metastasis ,Fibronectin ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Oncology ,Western blot ,030220 oncology & carcinogenesis ,Neuropilin 1 ,medicine ,biology.protein ,Cancer research - Abstract
AIMS Pancreatic neuroendocrine tumors (PanNETs) are usually diagnosed in an advanced stage. Most patients with PanNETs die of metastasis. Vascular endothelial growth factor-A (VEGF-A) is a strong stimulator of angiogenesis and tumor metastasis. We aimed to investigate the effect of MART-10 [19-nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3], a 1α,25-dihydroxy-vitamin D3 (1α,25(OH)2D3) analog, on PanNET cell metastasis after VEGF-A stimulation. MATERIALS AND METHODS Migration and invasion assays, western blot, and immunofluorescent staining were applied in this study. RESULTS VEGF-A increased PanNET cell migration and invasion, which was attenuated by 1α,25(OH)2D3 and MART-10. VEGF-A treatment stimulated epithelial-mesenchymal transition (EMT) of PanNET cells. During this process, expression of snail family transcriptional repressor 1 and 2, and fibronectin was up-regulated. 1α,25(OH)2D3 and MART-10 counteracted VEGF-A-induced EMT. In addition, expression of neuropilin 1, a key protein in VEGF-A signaling, was down-regulated by 1α,25(OH)2D3 and MART-10. Furthermore, synthesis of F-actin was increased by VEGF-A and reduced by 1α,25(OH)2D3 and MART-10. CONCLUSION Our data indicate that MART-10 could be deemed a promising drug for PanNET treatment.
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- 2017
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11. 1α,25(OH)
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Kun-Chun, Chiang, Chun-Nan, Yeh, Jong-Hwei S, Pang, Jun-Te, Hsu, Ta-Sen, Yeh, Li-Wei, Chen, Sheng-Fong, Kuo, Masashi, Takano, Tai C, Chen, Atsushi, Kittaka, Po-Jen, Hsieh, and Horng-Heng, Juang
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Gene Expression Regulation, Neoplastic ,Vascular Endothelial Growth Factor A ,Cell Movement ,Tumor Cells, Cultured ,Animals ,Apoptosis ,Insulinoma ,Cell Proliferation ,Cholecalciferol ,Rats - Abstract
Pancreatic neuroendocrine tumors (PanNETs) are usually diagnosed in an advanced stage. Most patients with PanNETs die of metastasis. Vascular endothelial growth factor-A (VEGF-A) is a strong stimulator of angiogenesis and tumor metastasis. We aimed to investigate the effect of MART-10 [19-nor-2α-(3-hydroxypropyl)-1α,25(OH)Migration and invasion assays, western blot, and immunofluorescent staining were applied in this study.VEGF-A increased PanNET cell migration and invasion, which was attenuated by 1α,25(OH)Our data indicate that MART-10 could be deemed a promising drug for PanNET treatment.
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- 2017
12. MART-10 represses cholangiocarcinoma cell growth and high vitamin D receptor expression indicates better prognosis for cholangiocarcinoma
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Yu Chan Chang, Kun Chun Chiang, Cheng Cheng Huang, Jong-Hwei S. Pang, Atsushi Kittaka, Chi-Tung Cheng, Tai C. Chen, Michael Hsiao, Chun Nan Yeh, Horng-Heng Juang, Ta Sen Yeh, Jun-Te Hsu, and Masashi Takano
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Male ,0301 basic medicine ,Kaplan-Meier Estimate ,Mice, SCID ,Calcitriol receptor ,Article ,Cholangiocarcinoma ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,Mice, Inbred NOD ,Cell Line, Tumor ,Vitamin D and neurology ,Animals ,Humans ,Cyclin D3 ,neoplasms ,Aged ,Cell Proliferation ,Cholecalciferol ,Mice, Knockout ,Multidisciplinary ,integumentary system ,biology ,Cell growth ,Middle Aged ,Prognosis ,Xenograft Model Antitumor Assays ,030104 developmental biology ,Bile Duct Neoplasms ,chemistry ,Cell culture ,Gene Knockdown Techniques ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Receptors, Calcitriol ,Female ,Cyclin-dependent kinase 6 ,Growth inhibition - Abstract
Cholangiocarcinoma (CCA) is a devastating disease due to no effective treatments available. Since the non-mineral functions of vitamin D emerges, 1α,25(OH)2D3, the active form of vitamin D, has been applied in anti-cancer researches. In this study, we demonstrated that both the 1α,25(OH)2D3 analog, MART-10, and 1α,25(OH)2D3 possessed anti-growth effect on human CCA cells with MART-10 much more potent than 1α,25(OH)2D3. The growth inhibition of both drugs were mediated by induction of G0/G1 cell cycle arrest through upregulation of p27 and downregulation of CDK4, CDK6, and cyclin D3. Human neutrophil gelatinase associated lipocalin (NGAL) was found to be involved in 1α,25(OH)2D3 and MART-10 meditated growth inhibition for CCA as knockdown of NGAL decreased Ki-67 expression in SNU308 cells and rendered SNU308 cells less responsive to 1α,25(OH)2D3 and MART-10 treatment. Vitamin D receptor (VDR) knockdown partly abolished MART-10-induced inhibition of NGAL and cell growth in SNU308 cells. The xenograft animal study demonstrated MART-10 could effectively repressed CCA growth in vivo without inducing obvious side effects. The IHC examination of human CCA specimen for VDR revealed that higher VDR expression was linked with better prognosis. Collectively, our results suggest that MART-10 could be a promising regimen for CCA treatment.
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- 2017
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13. Clinical and Environmental Correlates of Serum BDNF: A descriptive study with plausible implications for AD research
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Faisal Rahman, Galit Weinstein, Sarah R. Preis, Tai C. Chen, Ramachandran S. Vasan, Bernhard M. Kaess, Sudha Seshadri, Claudia L. Satizabal, Emelia J. Benjamin, and Alexa S. Beiser
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0301 basic medicine ,Adult ,Male ,Cross-sectional study ,Offspring ,Physiology ,Enzyme-Linked Immunosorbent Assay ,Disease ,Article ,Cohort Studies ,03 medical and health sciences ,Basal (phylogenetics) ,0302 clinical medicine ,Framingham Heart Study ,Alzheimer Disease ,Humans ,Homocysteine ,Brain-derived neurotrophic factor ,Psychiatric Status Rating Scales ,Tumor Necrosis Factor-alpha ,Brain-Derived Neurotrophic Factor ,Middle Aged ,030104 developmental biology ,C-Reactive Protein ,Cross-Sectional Studies ,Neurology ,Cohort ,Linear Models ,Female ,Neurology (clinical) ,Psychology ,Neuroscience ,030217 neurology & neurosurgery ,Cohort study - Abstract
Background: Brain derived neurotrophic factor (BDNF) may play a central role in the pathogenesis of Alzheimer's disease (AD) through neurotrophic effects on basal cholinergic neurons. Reduced serum levels of BDND are observed among AD patients and may predict AD risk. Nevertheless, knowledge about factors associated with its levels in blood is lacking. Objective: To identify clinical and demographic correlates of serum BDNF levels. Methods: BDNF was measured from serum collected between 1992-1996 and 1998-2001 in participants from the Original and Offspring cohorts of the Framingham Study, respectively. A cross-sectional analysis was done to evaluate the relationship between clinical measures and BDNF levels using standard linear regression and stepwise models. Analyses were conducted in the total sample and separately in each cohort, and were adjusted for age and sex. Results: BDNF was measured in 3,689 participants (mean age 65 years, 56% women; 82% Offspring). Cigarette smoking and high total cholesterol were associated with elevated BDNF levels, and history of atrial fibrillation was associated with decreased levels. Elevated BDNF levels were related to greater physical activity and lower Tumor Necrosis Factor-α levels in Offspring. Stepwise models also revealed associations with statin use, alcohol consumption and Apolipoprotein Ee4 genotype. Conclusion: Serum BDNF correlates with various metabolic, inflammatory and life-style measures which in turn have been linked with risk of AD. Future studies of serum BDNF should adjust for these correlates and are needed to further explore the underlying interplay between BDNF and other factors in the pathophysiology of cognitive impairment and AD.
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- 2017
14. Circulating Fat-Soluble Vitamin Concentrations and Nutrient Composition of Aquatic Prey Eaten by American Oystercatchers (Haematopus palliatus palliatus) in the Southeastern United States
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Patrick G. R. Jodice, Brad Winn, Tai C. Chen, Ellen S. Dierenfeld, Mark D. Spinks, Felicia J. Sanders, Batsheva A. Glatt, Lisa M. Mazzaro, Daphne Carlson-Bremer, and Terry M. Norton
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Vitamin ,education.field_of_study ,biology ,Ecology ,Vitamin E ,medicine.medical_treatment ,Population ,Wildlife ,Aquatic animal ,General Medicine ,biology.organism_classification ,Predation ,chemistry.chemical_compound ,Blood chemistry ,chemistry ,Oystercatcher ,medicine ,Small Animals ,education - Abstract
The American oystercatcher (Haematopus palliatus palliatus) is currently listed as a species of high concern by the United States Shorebird Conservation Plan. Because nutritional status directly impacts overall health and reproduction of individuals and populations, adequate management of a wildlife population requires intimate knowledge of a species' diet and nutrient requirements. Fat-soluble vitamin concentrations in blood plasma obtained from American oystercatchers and proximate, vitamin, and mineral composition of various oystercatcher prey species were determined as baseline data to assess nutritional status and nutrient supply. Bird and prey species samples were collected from the Cape Romain region, South Carolina, USA, and the Altamaha River delta islands, Georgia, USA, where breeding populations appear relatively stable in recent years. Vitamin A levels in blood samples were higher than ranges reported as normal for domestic avian species, and vitamin D concentrations were lower than anticipated based on values observed in poultry. Vitamin E levels were within ranges previously reported for avian groups with broadly similar feeding niches such as herons, gulls, and terns (eg, aquatic/estuarine/marine). Prey species (oysters, mussels, clams, blood arks [Anadara ovalis], whelks [ Busycon carica ], false angel wings [ Petricola pholadiformis ]) were similar in water content to vertebrate prey, moderate to high in protein, and moderate to low in crude fat. Ash and macronutrient concentrations in prey species were high compared with requirements of carnivores or avian species. Prey items analyzed appear to meet nutritional requirements for oystercatchers, as estimated by extrapolation from domestic carnivores and poultry species; excesses, imbalances, and toxicities-particularly of minerals and fat-soluble vitamins-may warrant further investigation.
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- 2014
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15. CYP24A1 as a Potential Target for Cancer Therapy
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Atsushi Kittaka, Keiko Yamamoto, Kaori Yasuda, Tai C. Chen, and Toshiyuki Sakaki
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Cancer Research ,Protein Conformation ,Vitamin D-binding protein ,Antineoplastic Agents ,Vitamin D3 24-Hydroxylase ,Pharmacology ,Biology ,Calcitriol receptor ,chemistry.chemical_compound ,CYP24A1 ,Neoplasms ,medicine ,Vitamin D and neurology ,Animals ,Humans ,Molecular Targeted Therapy ,Enzyme Inhibitors ,Cholecalciferol ,Cancer ,Biological activity ,Eldecalcitol ,medicine.disease ,chemistry ,Steroid Hydroxylases ,Molecular Medicine ,Metabolic Networks and Pathways - Abstract
Increasing evidence has accumulated to suggest that vitamin D may reduce the risk of cancer through its biologically active metabolite, 1α,25(OH)2D3, which inhibits proliferation and angiogenesis, induces differentiation and apoptosis, and regulates many other cellular functions. Thus, it is plausible to assume that rapid clearance of 1α,25(OH)2D3 by highly expressed CYP24A1 could interrupt the normal physiology of cells and might be one cause of cancer initiation and progression. In fact, enhancement of CYP24A1 expression has been reported in literature for many cancers. Based on these findings, CYP24A1-specific inhibitors and vitamin D analogs which are resistant to CYP24A1-dependent catabolism might be useful for cancer treatment. CYP24A1-specific inhibitor VID400, which is an azole compound, markedly enhanced and prolonged the antiproliferative activity of 1α,25(OH)2D3 in the human keratinocytes. Likewise, CYP24A1-resistant analogs such as 2α-(3-hydroxypropoxy)-1α,25(OH)2D3 (O2C3) and its C2-epimer ED-71 (Eldecalcitol), and 19nor- 2α-(3-hydroxypropyl)-1α,25(OH)2D3 (MART-10) showed potent biological effects. Our in vivo studies using rats revealed that MART-10 had a low calcemic effect, which is a suitable property as an anticancer drug. Much lower affinity of MART-10 for vitamin D binding protein (DBP) as compared with 1α,25(OH)2D3 may be related to its more potent cellular activities. Based on these results, we conclude that (1) high affinity for VDR, (2) resistance to CYP24A1-dependent catabolism, (3) low affinity for DBP, and (4) low calcemic effect may be required for designing potent vitamin D analogs for cancer treatment.
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- 2014
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16. FAT-SOLUBLE VITAMIN AND MINERAL COMPARISONS BETWEEN ZOO-BASED AND FREE-RANGING KOALAS (PHASCOLARCTOS CINEREUS)
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Debra A, Schmidt, Geoffrey W, Pye, Chris C, Hamlin-Andrus, William A, Ellis, Fred B, Bercovitch, Mark R, Ellersieck, Tai C, Chen, and Michael F, Holick
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inorganic chemicals ,Vitamin ,medicine.medical_treatment ,chemistry.chemical_element ,Animals, Wild ,Calcium ,chemistry.chemical_compound ,Nutrient ,Animal science ,Phascolarctos cinereus ,Reference Values ,biology.animal ,medicine ,Animals ,Minerals ,General Veterinary ,biology ,Ecology ,Phosphorus ,Vitamin E ,Vitamins ,General Medicine ,Fat-Soluble Vitamin ,chemistry ,Animals, Zoo ,Animal Science and Zoology ,Phascolarctidae ,Selenium - Abstract
As part of a health investigation on koalas at San Diego Zoo, serum samples were analyzed from 18 free-ranging and 22 zoo-based koalas, Phascolarctos cinereus. Serum concentrations of calcium, chloride, cobalt, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc, and vitamins A, E, and 25(OH)D3 were quantified. Calcium, chloride, molybdenum, selenium, and vitamin E concentrations were significantly higher in zoo-based koalas than in free-ranging koalas, whereas magnesium, manganese, phosphorus, and zinc concentrations were significantly higher in the free-ranging koalas. No significant differences were found between genders. The results from this study will help to establish a starting point for determining target circulating nutrient concentrations in koalas.
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- 2013
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17. MART-10, a novel vitamin D analog, inhibits head and neck squamous carcinoma cells growth through cell cycle arrest at G0/G1 with upregulation of p21 and p27 and downregulation of telomerase
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Chi-Chin Sun, Sheng-Fong Kuo, John N. Flanagan, Cheng-Cheng Huang, Shih-Wei Yang, Chun-Nan Yeh, Horng-Heng Juang, Tai C. Chen, Jong-Hwei S. Pang, Kun-Chun Chiang, Atsushi Kittaka, Li-Wei Chen, Jun-Te Hsu, and Masashi Takano
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Cyclin-Dependent Kinase Inhibitor p21 ,Telomerase ,Cell cycle checkpoint ,Endocrinology, Diabetes and Metabolism ,Blotting, Western ,Clinical Biochemistry ,Real-Time Polymerase Chain Reaction ,Biochemistry ,Endocrinology ,Downregulation and upregulation ,In vivo ,Cell Line, Tumor ,Humans ,Medicine ,Vitamin D ,neoplasms ,Molecular Biology ,Cholecalciferol ,Squamous Cell Carcinoma of Head and Neck ,Cell growth ,business.industry ,Cell Cycle ,Cell Cycle Checkpoints ,Cell Biology ,Flow Cytometry ,medicine.disease ,Head and neck squamous-cell carcinoma ,Squamous carcinoma ,stomatognathic diseases ,Head and Neck Neoplasms ,Cancer cell ,Immunology ,Carcinoma, Squamous Cell ,Cancer research ,Molecular Medicine ,business ,Cyclin-Dependent Kinase Inhibitor p27 - Abstract
For the head and neck squamous cell carcinoma (HNSCC), surgery in combination with radiation therapy is the current standard treatment. However, the complex anatomy and important functions over the head and neck region often make HNSCC patients with severe comorbidities. Even after aggressive treatment, the 5 year survival for HNSCC patients is only around 61%. Thus, new therapeutic regimens against HNSCC are urgently needed. 1α,25-Dihydroxyvitamin D 3 [1α,25(OH) 2 D 3 ] is a potent anti-tumor agent in a variety of pre-clinical studies, but its clinical application is impeded by hypercalcemic side effect. A new class of less-calcemic 1α,25(OH) 2 D 3 analog, MART-10 (19-nor-2α-(3-hydroxypropyl)- 1α,25-Dihydroxyvitamin D 3 ), has been shown to be much more potent than 1α,25(OH) 2 D 3 in inhibiting cancer cell growth in vitro and in vivo without inducing hypercalcemia. In this study, we compared the antiproliferative activity of MART-10 with 1α,25(OH) 2 D 3 and the mechanism responsible for the inhibition in FaDu and SCC-25 squamous carcinoma cells. Our results demonstrate that MART-10 is more potent than 1α,25(OH) 2 D 3 in suppressing FaDu and SCC-25 cell growth through greater cell cycle arrest at G 0 /G 1 , accompanied by a greater downregulation of ki-67 expression and upregulation of p21 and p27. We also showed that telomerase expression in SCC-25 was suppressed to a greater extent by MART-10 than by 1α,25(OH) 2 D 3. Thus, given the previously-proven in vivo antitumor effect and safety of MART-10 and bleak background of HNSCC, based on our current result, we concluded that MART-10 has a potential as a chemo-preventive and – therapeutic agent to treat HNSCC.
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- 2013
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18. Serum Brain–Derived Neurotrophic Factor and Vascular Endothelial Growth Factor Levels Are Associated With Risk of Stroke and Vascular Brain Injury
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Charles DeCarli, Sarah R. Preis, Rhoda Au, Demetrios Vorgias, Tai C. Chen, Ramachandran S. Vasan, Aleksandra Pikula, Sudha Seshadri, Alexa S. Beiser, Margaret Kelly-Hayes, Philip A. Wolf, and Carlos S. Kase
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Advanced and Specialized Nursing ,Brain-derived neurotrophic factor ,medicine.medical_specialty ,business.industry ,medicine.disease ,Hyperintensity ,Brain ischemia ,Vascular endothelial growth factor ,Vascular endothelial growth factor A ,chemistry.chemical_compound ,Framingham Heart Study ,chemistry ,Neurotrophic factors ,Internal medicine ,Physical therapy ,medicine ,Cardiology ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine ,business ,Stroke - Abstract
Background and Purpose— Brain-derived neurotrophic factor (BDNF), a major neurotrophin and vascular endothelial growth factor (VEGF) have a documented role in neurogenesis, angiogenesis, and neuronal survival. In animal experiments, they impact infarct size and functional motor recovery after an ischemic brain lesion. We sought to examine the association of serum BDNF and VEGF with the risk of clinical stroke or subclinical vascular brain injury in a community-based sample. Methods— In 3440 Framingham Study participants (mean age, 65±11 years; 56% women) who were free of stroke/transient ischemic attack (TIA), we related baseline BDNF and logVEGF to risk of incident stroke/TIA. In a subsample with brain MRI and with neuropsychological tests available (n=1863 and 2104, respectively; mean age, 61±9 years, 55% women, in each), we related baseline BDNF and logVEGF to log-white matter hyperintensity volume on brain MRI, and to visuospatial memory and executive function tests. Results— During a median follow-up of 10 years, 193 participants experienced incident stroke/TIA. In multivariable analyses adjusted for age, sex, and traditional stroke risk factors, lower BDNF and higher logVEGF levels were associated with an increased risk of incident stroke/TIA (hazard ratio comparing BDNF Q1 versus Q2–Q4, 1.47; 95% confidence interval, 1.09–2.00; P =0.012 and hazard ratio/SD increase in logVEGF, 1.21; 95% confidence interval, 1.04–1.40; P =0.012). Persons with higher BDNF levels had less log-white matter hyperintensity volume (β±SE=−0.05±0.02; P =0.025), and better visual memory (β±SE=0.18±0.07; P =0.005). Conclusions— Lower serum BDNF and higher VEGF concentrations were associated with increased risk of incident stroke/TIA. Higher levels of BDNF were also associated with less white matter hyperintensity and better visual memory. Our findings suggest that circulating BDNF and VEGF levels modify risk of clinical and subclinical vascular brain injury.
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- 2013
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19. A cross-sectional study of osteocalcin and body fat measures among obese adolescents
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Stephanie H. Abrams, Tai C. Chen, Henry A. Feldman, Richard T. Alongi, Darrell M. Wilson, Stephen E. Gitelman, Marcia S. Wertz, Michael F. Holick, Carine M. Lenders, Phillip D.K. Lee, William J. Klish, and George A. Taylor
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medicine.medical_specialty ,Intra-Abdominal Fat ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Parathyroid hormone ,Adipose tissue ,030209 endocrinology & metabolism ,vitamin D deficiency ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,medicine ,Vitamin D and neurology ,030304 developmental biology ,0303 health sciences ,Nutrition and Dietetics ,biology ,business.industry ,Leptin ,medicine.disease ,Osteocalcin ,biology.protein ,business ,Body mass index - Abstract
Osteocalcin (OCN), a marker of osteoblast activity, has been implicated in the regulation of energy metabolism by the skeleton and thus may affect body fat measures. We examined the relationships of OCN to body fat measures and whether they vary according to markers of energy and vitamin D metabolism. Data was obtained from 58 obese adolescents aged 13–17.9 years (38 females, 8 black or African-American). We calculated total fat mass (FM) [dual X-ray absorptiometry (DXA)] and visceral adipose tissue (VAT) [computerized axial tomography (CT)]. Blood tests included leptin, OCN, 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), thyroid function tests, and triglycerides. Markers of glucose metabolism were obtained from fasting and OGTT samples. Adolescents with 25(OH)D
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- 2013
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20. Human cytochrome P450-dependent differential metabolism among three 2α-substituted-1α,25-dihydroxyvitamin D3 analogs
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Toshiyuki Sakaki, Kaori Yasuda, Masashi Takano, Shinichi Ikushiro, Miho Ohta, Masaki Kamakura, Tai C. Chen, Nozomi Saito, and Atsushi Kittaka
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Stereochemistry ,Vitamin D-binding protein ,Endocrinology, Diabetes and Metabolism ,Metabolite ,Clinical Biochemistry ,Vitamin D3 24-Hydroxylase ,In Vitro Techniques ,Biochemistry ,Calcitriol receptor ,Hydroxylation ,Structure-Activity Relationship ,chemistry.chemical_compound ,Endocrinology ,Calcitriol ,Microsomes ,Intestine, Small ,Vitamin D and neurology ,Cytochrome P-450 CYP3A ,Humans ,Molecular Biology ,Cholecalciferol ,biology ,Cytochrome P450 ,Cell Biology ,Recombinant Proteins ,Kinetics ,chemistry ,Steroid Hydroxylases ,Microsomes, Liver ,biology.protein ,Microsome ,Receptors, Calcitriol ,Molecular Medicine - Abstract
Our previous studies revealed that C2α-substituted-1α,25(OH)(2)D(3) analogs had unique biological activities. For example, 19-nor-2α-(3-hydroxypropyl)-1α,25(OH)(2)D(3) (MART-10), which has a high affinity for vitamin D receptor (VDR), is more bioavailable and more potent than 1α,25(OH)(2)D(3) in inhibiting cancer cell growth and invasion because of its weaker binding to vitamin D binding protein (DBP), and more resistance to CYP24A1-dependent metabolism. In this study, we examined the metabolism of MART-10 and two other 2α-substituted analogs, 2α-(3-hydroxypropoxy)-1α,25(OH)(2)D(3) (O2C3) and 2α-(3-hydroxypropyl)-1α,25(OH)(2)D(3) (O1C3) by using human liver microsomes and human P450s. We demonstrated that O2C3 was converted to 1α,2α,25(OH)(3)D(3) in human liver microsomes, whereas both O1C3 and MART-10 were hardly metabolized. The metabolism of O2C3 was significantly inhibited by ketoconazole, and the recombinant human CYP3A4 converted O2C3 to 1α,2α,25(OH)(3)D(3), which suggests that CYP3A4 is responsible for the metabolism of O2C3 in human liver. The k(cat)/K(m) values of CYP3A4 for O1C3 and MART-10 are much smaller than that for O2C3. The k(cat)/K(m) values of human CYP24A1 for the three analogs are 1% (MART-10), 3% (O2C3), and 4% (O1C3) of that for 1α,25(OH)(2)D(3), indicating that MART-10 is the most resistant to CYP24A1 hydroxylation. On the other hand, 1α,2α,25(OH)(3)D(3), the metabolite of O2C3 by CYP3A4, was metabolized by CYP24A1 via multiple pathways similar to 1α,25(OH)(2)D(3), which suggests that O2C3 can be metabolized by two sequential hydroxylations, first by CYP3A4 and then by CYP24A1 in human body. These results suggest that modification at C-2α position and C-19 demethylenation markedly change metabolic profiles and biological activities of vitamin D analogs.
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- 2013
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21. 25(OH)D Is Effective to Repress Human Cholangiocarcinoma Cell Growth through the Conversion of 25(OH)D to 1α,25(OH)₂D₃
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Kun-Chun, Chiang, Chun-Nan, Yeh, Cheng-Cheng, Huang, Ta-Sen, Yeh, Jong-Hwei, S Pang, Jun-Te, Hsu, Li-Wei, Chen, Sheng-Fong, Kuo, Atsushi, Kittaka, Tai C, Chen, and Horng-Heng, Juang
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25-Hydroxyvitamin D3 1-alpha-Hydroxylase ,Male ,Mice, Inbred BALB C ,25(OH)D ,1α-OHase ,Mice, Nude ,vitamin D ,Immunohistochemistry ,Xenograft Model Antitumor Assays ,Article ,Cholangiocarcinoma ,Mice ,Calcitriol ,CYP27B1 ,Cell Line, Tumor ,Animals ,Humans ,Cell Proliferation - Abstract
Cholangiocarcinoma (CCA) is a devastating disease without effective treatments. 1α,25(OH)2D3, the active form of Vitamin D, has emerged as a new anti-cancer regimen. However, the side effect of hypercalcemia impedes its systemic administration. 25(OH)D is biologically inert and needs hydroxylation by CYP27B1 to form 1α,25(OH)2D3, which is originally believed to only take place in kidneys. Recently, the extra-renal expression of CYP27B1 has been identified and in vitro conversion of 25(OH)D to 1α,25(OH)2D3 has been found in some cancer cells with CYP27B1 expression. In this study, CYP27B1 expression was demonstrated in CCA cells and human CCA specimens. 25(OH)D effectively represses SNU308 cells growth, which was strengthened or attenuated as CYP27B1 overexpression or knockdown. Lipocalcin-2 (LCN2) was also found to be repressed by 25(OH)D. After treatment with 800 ng/mL 25(OH)D, the intracellular 1α,25(OH)2D3 concentration was higher in SNU308 cells with CYP27B1 overexpression than wild type SNU308 cells. In a xenograft animal experiment, 25(OH)D, at a dose of 6 μg/kg or 20 μg/kg, significantly inhibited SNU308 cells’ growth without inducing obvious side effects. Collectively, our results indicated that SNU308 cells were able to convert 25(OH)D to 1α,25(OH)2D3 and 25(OH)D CYP27B1 gene therapy could be deemed as a promising therapeutic direction for CCA.
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- 2016
22. MART-10, a newly synthesized vitamin D analog, represses metastatic potential of head and neck squamous carcinoma cells
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Atsushi Kittaka, Tai C. Chen, Jong-Hwei S. Pang, Yi-Chun Pan, Kun-Chun Chiang, Chun-Nan Yeh, Horng-Heng Juang, Shih-Wei Yang, Chi-Ying Tsai, and Masashi Takano
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Pharmaceutical Science ,Down-Regulation ,Antineoplastic Agents ,Metastasis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,Cell Line, Tumor ,Drug Discovery ,medicine ,Humans ,metastasis ,Epithelial–mesenchymal transition ,Neoplasm Metastasis ,Vitamin D ,neoplasms ,Cholecalciferol ,Original Research ,vitamin D analog ,Pharmacology ,Drug Design, Development and Therapy ,integumentary system ,business.industry ,EMT ,Cancer ,MART-10 ,medicine.disease ,Head and neck squamous-cell carcinoma ,In vitro ,Squamous carcinoma ,030104 developmental biology ,chemistry ,Matrix Metalloproteinase 9 ,Head and Neck Neoplasms ,030220 oncology & carcinogenesis ,Cancer research ,Carcinoma, Squamous Cell ,head and neck cancer ,business - Abstract
Shih-Wei Yang,1,* Chi-Ying Tsai,2,* Yi-Chun Pan,3 Chun-Nan Yeh,4 Jong-Hwei S Pang,5 Masashi Takano,6 Atsushi Kittaka,6 Horng-Heng Juang,7 Tai C Chen,8 Kun-Chun Chiang4,9 1Department of Otolaryngology– Head and Neck Surgery, Chang Gung Memorial Hospital, Keelung, 2Department of Oral and Maxillofacial Surgery, Chang Gung Memorial Hospital, Taoyuan, 3Department of General Dentistry, Chang Gung Memorial Hospital, Chang Gung University, Keelung, 4General Surgery Department, Chang Gung Memorial Hospital, Keelung, 5Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; 6Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan; 7Department of Anatomy, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; 8Endocrine Core Laboratory, Boston University School ofMedicine, Boston, MA,USA; 9Zebrafish Center, Chang GungMemorial Hospital, Keelung, Taiwan, Republic of China *These authors contributed equally tothiswork Abstract: Even with multidisciplinary treatment, the prognosis and quality of life of patients diagnosed with head and neck squamous cell carcinoma (HNSCC) are still not satisfactory. Previously, 19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3 (MART-10), the new brand 1α,25(OH)2D3 analog, has been demonstrated to be an effective drug to inhibit HNSCC growth in vitro. Since most cancer patients die of metastasis, in this study, the antimetastatic effect of MART-10 on HNSCC was investigated. Our results reveal that both 1α,25(OH)2D3 and MART-10 effectively repressed the migration and invasion of HNSCC cells, with MART-10 being much more potent than 1α,25(OH)2D3. The antimetastatic effect of 1α,25(OH)2D3 and MART-10 was mediated by attenuation of epithelial–mesenchymal transition (EMT), which was supported by the finding that the expression of EMT-inducing transcriptional factors, Sail and Twist, was inhibited by 1α,25(OH)2D3 and MART-10. The upregulation of E-cadherin and downregulation of N-cadherin in FaDu cells induced by both drugs further confirmed the repression of EMT. In addition, 1α,25(OH)2D3 and MART-10 treatment inhibited intracellular MMP-9 expression and extracellular MMP activity in FaDu cells. Collectively, our results suggest that the less-calcemia 1α,25(OH)2D3 analog, MART-10, is a promising drug for HNSCC treatment. Further clinical studies are warranted. Keywords: EMT, head and neck cancer, vitamin D analog, metastasis, MART-10
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- 2016
23. 1α,25(OH)2D3 Analog, MART-10, Inhibits Neuroendocrine Tumor Cell Growth Through Induction of G0/G1 Cell-cycle Arrest and Apoptosis
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Kun-Chun, Chiang, Chun-Nan, Yeh, Jong-Hwei S, Pang, Jun-Te, Hsu, Ta-Sen, Yeh, Li-Wei, Chen, Sheng-Fong, Kuo, Po-Jen, Hsieh, Yi-Chun, Pan, Masashi, Takano, Tai C, Chen, Tsui-Hsia, Feng, Atsushi, Kittaka, and Horng-Heng, Juang
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Cyclin-Dependent Kinase 4 ,Apoptosis ,Cell Growth Processes ,G1 Phase Cell Cycle Checkpoints ,Rats ,Pancreatic Neoplasms ,Neuroendocrine Tumors ,Calcitriol ,Cell Line, Tumor ,Animals ,Receptors, Calcitriol ,Insulinoma ,Cyclin-Dependent Kinase Inhibitor p27 ,Cholecalciferol - Abstract
Neuroendocrine tumors (NETs) are the second most common digestive malignancy. For advanced NETs, survival is not satisfactory. Vitamin D has emerged as a promising anticancer drug.Cell proliferation assay, western blot, flow cytometry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were applied.We demonstrated that RIN-m cells, neuroendocrine tumor cells, expressed vitamin D receptor (VDR) and VDR expression increased with increasing exposure to 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] or MART-10, a 1α,25(OH)2D3 analog. MART-10 had anti-growth effect on RIN-m cells comparable to those of 1α,25(OH)2D3 The growth inhibition of both drugs was mediated by induction of cell-cycle arrest at G0/G1 phase and apoptosis. Western blot assay further revealed that this G0/G1 arrest was due to the up-regulation of p27 and down-regulation of cyclin dependent kinase 4 (CDK4), with MART-10 also reducing CDK6. Apoptosis induction was further supported by increased cleaved caspase-3 expression after treatment.MART-10 appears to be a promising regimen for NET treatment.
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- 2016
24. Metabolism and Action of 25-Hydroxy-19-nor-Vitamin D₃ in Human Prostate Cells
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Eiji, Munetsuna, Atsushi, Kittaka, Tai C, Chen, and Toshiyuki, Sakaki
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Male ,Molecular Structure ,Humans ,Prostatic Neoplasms ,Receptors, Calcitriol ,Antineoplastic Agents ,Cell Proliferation ,Cholecalciferol - Abstract
Since the discovery of 1α,25(OH)2D3 in the early 1970s, it has been widely accepted that this metabolite is responsible for the biological actions of vitamin D. Likewise, we have assumed that 25(OH)-19-nor-D3-dependent growth inhibition of human prostate PZ-HPV-7 cells was the result of its subsequent conversion to 1α,25(OH)2-19-nor-D3, catalyzed by CYP27B1 within the prostate cells. However, further in vitro studies in a reconstituted system using recombinant CYP27B1 revealed that 25(OH)-19-nor-D3 was hardly converted to 1α,25(OH)2-19-nor-D3 by the enzyme. The kinetic analysis of 1α-hydroxylation of 25(OH)D3 and 25(OH)-19-nor-D3 demonstrated that the k(cat)/K(m) for 25(OH)-19-nor-D3 is less than 0.1% of that for 25(OH)D3. When 25(OH)-19-nor-D3 was added to cultured PZ-HPV-7 cells, eight metabolites were detected, while no 1α,25(OH)2-19-nor-D3 was found. In addition, the time course of VDR translocation into the nucleus induced by 100 nM 25(OH)-19-nor-D3, and the subsequent transactivation of CYP24A1 gene were almost identical to those induced by 1 nM 1α,25(OH)2-19-nor-D3. These results strongly suggest that 25(OH)-19-nor-D3 binds directly to VDR as a ligand to transport VDR into the nucleus to induce CYP24A1 gene transactivation. Furthermore, knockdown of CYP27B1 gene did not affect the antiproliferative activity of 25(OH)-19-nor-D3, whereas VDR knockdown attenuated the effect, suggesting that the antiproliferative activity of 25(OH)-19-nor-D3 is VDR dependent but CYP27B1 independent. Finally, our recent studies using the same cell line demonstrate that 25(OH)D3 can act as a VDR agonist to induce gene transactivation. These findings suggest that vitamin D analogs without 1α-hydroxyl group could be developed as drugs for osteoporosis or cancer treatment.
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- 2016
25. Effects of sunlight and diet on vitamin D status of pulmonary tuberculosis patients in Tbilisi, Georgia
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Veriko Mirtskhulava, Russell R. Kempker, Shabnam Seydafkan, Henry M. Blumberg, Tai C. Chen, Nirali S. Desai, Thomas R. Ziegler, Nestani Tukvadze, Maia Kipiani, Jennifer K. Frediani, Gautam Hebbar, Memorie Nichols, Vin Tangpricha, Ekaterine Sanikidze, Iagor Kalandadze, and Nilay Sutaria
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Adult ,Male ,medicine.medical_specialty ,Georgia ,Tuberculosis ,animal diseases ,Endocrinology, Diabetes and Metabolism ,Nutritional Status ,chemical and pharmacologic phenomena ,Gastroenterology ,Article ,vitamin D deficiency ,Nutrition Policy ,Young Adult ,7-Dehydrocholesterol ,chemistry.chemical_compound ,Dehydrocholesterols ,Pulmonary tuberculosis ,Internal medicine ,Prevalence ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Tuberculosis, Pulmonary ,Cholecalciferol ,Sunlight ,Nutrition and Dietetics ,business.industry ,Dietary intake ,Nutritional Requirements ,Vitamins ,biochemical phenomena, metabolism, and nutrition ,Middle Aged ,Vitamin D Deficiency ,medicine.disease ,Diet ,Endocrinology ,chemistry ,bacteria ,Female ,business - Abstract
Vitamin D deficiency is common in tuberculosis (TB) and this may modulate immune responses. This study investigated vitamin D status in patients with TB and examined the sources of vitamin D in Tbilisi, Georgia.We measured plasma 25-hydroxyvitamin D (25[OH]D) and dietary vitamin D intake in patients with pulmonary TB (n = 85) in Tbilisi, Georgia. To determine the impact of season on vitamin D status, we tested the in vitro conversion of 7-dehydrocholesterol (7-DHC) to previtamin D(3) after sunlight exposure.In subjects with TB, mean plasma 25(OH)D concentrations were 14.4 ± 7.0 ng/mL, and vitamin D insufficiency (25[OH]D30 ng/mL) occurred in 97% of subjects. The dietary sources of vitamin D were mainly fish, eggs, and butter. The daily intake was well below recommended daily intakes in subjects with TB (172 ± 196 IU). The conversion of 7-DHC to previtamin D(3) was undetectable from October to March and highest in June and July from 11:00 to 14:00 h.An insufficient vitamin D dietary intake and a limited production of vitamin D from sunlight for most of the year may explain the high prevalence of vitamin D insufficiency in patients with TB in Tbilisi.
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- 2012
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26. Synthesis and Biological Activities of 1α,4α,25- and 1α,4β,25-Trihydroxyvitamin D3 and Their Metabolism by Human CYP24A1 and UDP-Glucuronosyltransferase
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Ken Ichiro Takagi, Kazuya Takenouchi, Toshiyuki Sakaki, Kaori Yasuda, Daisuke Sawada, Tai C. Chen, Yuya Tsukuda, Hiroshi Saito, G. Satyanarayana Reddy, and Atsushi Kittaka
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Chemistry ,Metabolite ,Vitamin D3 24-Hydroxylase ,General Chemistry ,General Medicine ,Metabolism ,Calcitriol receptor ,chemistry.chemical_compound ,Transactivation ,Biochemistry ,CYP24A1 ,Drug Discovery ,Vitamin D and neurology ,Receptor - Abstract
A previous report has demonstrated the existence of a C4-hydroxylated vitamin D(2) metabolite in serum of rats treated with pharmacological doses of vitamin D(2). However, the biological significance and metabolic fate of this metabolite have not been described. To explore its potential biological activities, we therefore synthesized 1α,4α,25-trihydroxyvitamin D(3) and its diastereoisomer, 1α,4β,25-trihydroxyvitamin D(3), using Trost Pd-mediated coupling reaction, and studied their vitamin D receptor (VDR) binding affinity, osteocalcin promoter transactivation activity, and their further metabolism by human CYP24A1 as well as by human liver microsomal fraction based on CYP- and UDP-glucuronosyltransferases (UGTs)-reactions.
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- 2012
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27. 19-Nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10) is a potent cell growth regulator with enhanced chemotherapeutic potency in liver cancer cells
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Jim-Ming Lee, Masashi Takano, Tai C. Chen, Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Kun-Chun Chiang, Huang-Yang Chen, and Miin-Fu Chen
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Cyclin-Dependent Kinase Inhibitor p21 ,medicine.medical_specialty ,Clinical Biochemistry ,Antineoplastic Agents ,Apoptosis ,Biology ,Biochemistry ,Calcitriol receptor ,Endocrinology ,Downregulation and upregulation ,Internal medicine ,medicine ,Humans ,Vitamin D ,Molecular Biology ,Cell Proliferation ,Cholecalciferol ,Pharmacology ,Cell growth ,Cell Cycle ,Liver Neoplasms ,Organic Chemistry ,Hep G2 Cells ,Cell cycle ,medicine.disease ,VDRE ,Gene Expression Regulation, Neoplastic ,Cancer cell ,Cancer research ,Liver cancer ,Cyclin-Dependent Kinase Inhibitor p27 - Abstract
The discovery that the active form of vitamin D, 1α,25-dihydroxyvitamin D [1α,25(OH)(2)D] can modulate cellular proliferation and differentiation of cancer cells has led to its potential application as a chemotherapeutic agent to treat a variety of cancers. However, the use of 1α,25(OH)(2)D is limited due to its lethal side effect of hypercalcemia upon systemic administration. To overcome this drawback, numerous analogs have been synthesized. In this report, we examined the anti-proliferative activity of a new analog, 19-nor-2α-(3-hydroxypropyl)-1α,25(OH)(2)D(3) (MART-10), in HepG2 liver cancer cells, and studied the potential mechanisms mediating this action. We found that MART-10 exhibited approximately 100-fold greater activity than 1α,25(OH)(2)D(3) in inhibiting HepG2 cell proliferation as determined by cell number counting method. MART-10 was also approximately 100-fold more potent than 1α,25(OH)(2)D(3) in the upregulation of p21 and p27, that in turn arrested HepG2 cells at the G(0)/G(1) phase to a greater extent. Given that no active caspase 3 was detected and treatment with 1α,25(OH)(2)D(3) or MART-10 did not further increase the fractions of apoptotic and necrosis cells over the controls, the growth-inhibitory effect of 1α,25(OH)(2)D(3) and MART-10 on HepG2 cells may not involve apoptosis. Overall, our findings suggest that MART-10 is a good candidate as a novel therapeutic regimen against liver cancer. Further pre-clinical studies using animal models and the subsequent human clinical trials are warranted.
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- 2011
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28. Investigating the mechanism for maintaining eucalcemia despite immobility and anuria in the hibernating American black bear (Ursus americanus)
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Clifford J. Rosen, Randal A. Cross, William A. Halteman, Walter J. Jakubas, Richard M. Seger, Rita L. Seger, Frederick A. Servello, Caren M. Gundberg, Tai C. Chen, Thomas O. Carpenter, Michael F. Holick, Duane H. Keisler, and Robert Causey
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Hibernation ,medicine.medical_specialty ,Histology ,Physiology ,Endocrinology, Diabetes and Metabolism ,Parathyroid hormone ,Anuria ,Collagen Type I ,Bone resorption ,Bone remodeling ,Immobilization ,chemistry.chemical_compound ,Osteogenesis ,biology.animal ,Internal medicine ,medicine ,Animals ,Ursus ,biology ,Leptin ,Alkaline Phosphatase ,biology.organism_classification ,United States ,Endocrinology ,chemistry ,Organ Specificity ,Bone Morphogenetic Proteins ,Sclerostin ,Calcium ,Female ,Bone Remodeling ,Seasons ,Peptides ,American black bear ,Biomarkers ,Ursidae - Abstract
Ursine hibernation uniquely combines prolonged skeletal unloading, anuria, pregnancy, lactation, protein recycling, and lipolysis. This study presents a radiographic and biochemical picture of bone metabolism in free-ranging, female American black bears (Ursus americanus) that were active (spring bears and autumn bears) or hibernating (hibernating bears). Hibernating bears included lactating and non-lactating individuals. We measured serum calcium, albumin, inorganic phosphate, creatinine, bone specific alkaline phosphatase (BSALP), CTX, parathyroid hormone, insulin-like growth factor-I (IGF-l), leptin, 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and sclerostin from 35 to 50 tranquilized hibernating bears and 14 to 35 tranquilized spring bears. We compared metacarpal cortical indices (MCI), measured by digital X-ray radiogrammetry, from 60 hunter-killed autumn bears and 79 tranquilized, hibernating bears. MCI was greater in autumn than winter in younger bears, but showed no seasonal difference in older bears. During hibernation eucalcemia was maintained, BSALP was suppressed, and CTX was in the range expected for anuria. During hibernation 1,25(OH)(2)D was produced despite anuria. 1,25(OH)(2)D and IGF-I were less in hibernating than spring bears. In a quarter of hibernating bears, sclerostin was elevated. Leptin was greater in hibernating than spring bears. In hibernating bears, leptin correlated positively with BSALP in non-lactating bears and with CTX in lactating bears. Taken together the biochemical and radiographic findings indicate that during hibernation, bone turnover was persistent, balanced, and suppressed; bone resorption was lower than expected for an unloaded skeleton; and there was no unloading-induced bone loss. The skeleton appears to perceive that it was loaded when it was actually unloaded during hibernation. However, at the level of sclerostin, the skeleton recognized that it was unloaded. During hibernation leptin appeared anabolic in non-lactating bears and catabolic in lactating bears. We hypothesize that ursine hibernation may represent a natural model in which suppression of the sympathetic nervous system prevents unloading-induced bone loss by influencing leptin's skeletal effects and preventing transmission of loading information.
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- 2011
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29. Hepatocellular carcinoma and vitamin D: A review
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Chun-Nan Yeh, Tai C. Chen, Kun-Chun Chiang, and Miin-Fu Chen
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Hepatology ,business.industry ,medicine.medical_treatment ,Gastroenterology ,medicine.disease ,vitamin D deficiency ,Steroid hormone ,Regimen ,Hepatocellular carcinoma ,Immunology ,medicine ,Carcinoma ,Vitamin D and neurology ,Cancer research ,business ,Receptor ,Inhibitory effect - Abstract
The non-classical actions of vitamin D, namely antiproliferation, pro-differentiation, pro-apoptosis, anti-inflammation, and immune regulation, have received great attention during the past decade. Increasing evidence from epidemiological studies showing the inverse association between vitamin D status and incidence of many forms of cancer as well as biochemical studies has suggested that vitamin D deficiency may play a role in the cause and progression of these types of cancer. Recently, vitamin D and its analogs have been deemed as potential regimen to treat a variety of cancers alone or in combination with other drugs. Although, the epidemiologic evidence regarding the association of vitamin D and hepatocellular carcinoma (HCC) is still inconclusive, biochemical evidence clearly indicates that HCC cells are responsive to the inhibitory effect of vitamin D and its analogs. In this review, we discuss the current status of HCC and its treatment, the source, metabolism, functions, and the mechanism of actions of vitamin D, and the biochemical studies of vitamin D analogs and their implications in the prevention and treatment of HCC.
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- 2011
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30. Use of a novel vitamin D bioavailability test demonstrates that vitamin D absorption is decreased in patients with quiescent crohnʼs disease1,2,3
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Kleanthis Dendrinos, Tai C. Chen, H. Nimitphong, A. Vijjeswarapu, Rachael M. Biancuzzo, Michael F. Holick, A. B. Boulanger, Francis A. Farraye, Arthur F. Stucchi, and A. Tanennbaum
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Vitamin ,medicine.medical_specialty ,Crohn's disease ,Malabsorption ,business.industry ,Gastroenterology ,Case-control study ,medicine.disease ,vitamin D deficiency ,Intestinal absorption ,Bioavailability ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,medicine ,Vitamin D and neurology ,Immunology and Allergy ,business - Abstract
Background: Vitamin D deficiency is a common problem in patients with Crohn's disease (CD). The aim of this study was to determine the ability of normal subjects and patients with quiescent CD to absorb vitamin D2 using a novel vitamin D bioavailability test. In addition, we evaluated whether the location of disease or previous surgery had any influence on the bioavailability of vitamin D2 in CD patients. Methods: Ten normal subjects (50% female) and 37 CD patients with quiescent disease (51% female) were included in this study. Subjects who recently received any vitamin D2 were excluded. The vitamin D bioavailability test was performed in all subjects. After a baseline blood draw, all subjects were then given a single 50,000 IU oral dose of vitamin D2 in a capsule formulation and had their blood drawn 12 hours later to determine serum vitamin D2, which reflected their vitamin D2 absorption capacity. Results: Forty-two percent and 29% of CD patients were found to be either vitamin D-deficient (25-hydroxyvitamin D [25(OH)D] ≤20 ng/mL] or insufficient [25(OH)D 21–29 ng/mL], respectively. Twelve hours after ingesting 50,000 IU vitamin D2, vitamin D2 levels rose from a baseline of 0.7 ± 0.7 ng/mL (mean ± SEM) to 49.8 ± 3.0 ng/mL in normal subjects. In CD patients, baseline vitamin D2 levels rose from 0 ng/mL to 34.8 ± 2.8 ng/mL. CD patients had on average a 30% decrease in their ability to absorb vitamin D2 (P = 0.01). Moreover, we found a wide variability of vitamin D2 bioavailability in CD patients. Analysis of variance (ANOVA) revealed no statistical difference of vitamin D2 bioavailability between patients in the CD subgroup stratified by the location of disease, the type of surgery, and receiving or not receiving surgery. Conclusions: More than 70% of the patients with quiescent CD were vitamin D-deficient or insufficient. The ability to absorb vitamin D2 in CD patients is unpredictable and the only way to determine this is to perform a vitamin D bioavailability test. Use of this test may guide clinicians in administering the appropriate therapeutic dose of vitamin D for treating vitamin D deficiency in patients with CD. (Inflamm Bowel Dis 2011;)
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- 2011
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31. Mechanism of the anti-proliferative action of 25-hydroxy-19-nor-vitamin D3 in human prostate cells
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Toshiyuki Sakaki, Kaori Yasuda, Atsushi Kittaka, Masaki Kamakura, Tai C. Chen, Eiji Munetsuna, Midori A. Arai, Shinichi Ikushiro, Rie Kawanami, Miho Ohta, and Sachie Nakabayashi
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Reverse Transcriptase Polymerase Chain Reaction ,Blotting, Western ,Vitamin D3 24-Hydroxylase ,Calcitriol receptor ,Molecular biology ,Cell Line ,Hydroxylation ,Protein Transport ,chemistry.chemical_compound ,Transactivation ,Endocrinology ,Calcitriol ,chemistry ,CYP24A1 ,Steroid Hydroxylases ,Vitamin D and neurology ,Humans ,Receptors, Calcitriol ,RNA, Small Interfering ,Cholecalciferol ,Receptor ,Molecular Biology ,Cell Proliferation - Abstract
According to the prevailing paradigm, 1α-hydroxylation of 25-hydroxyvitamin D3 (25(OH)D3) and its analogs is a pre-requisite step for their biological effects. We previously reported that 25-hydroxy-19-nor-vitamin D3 (25(OH)-19-nor-D3) had anti-proliferative activity in a cell line, PZ-HPV-7, which was derived from human non-cancerous prostate tissue, and suggested that 25(OH)-19-nor-D3 acted after 1α-hydroxylation by vitamin D 1α-hydroxylase (CYP27B1). However, metabolic studies of 25(OH)-19-nor-D3 using recombinant CYP27B1 revealed that 25(OH)-19-nor-D3 was rarely subjected to 1α-hydroxylation. Therefore, in this report, we attempted to clarify the mechanism of 25(OH)-19-nor-D3 action in intact cells using PZ-HPV-7 prostate cells. After incubating the cells with 25(OH)-19-nor-D3, eight metabolites of 24-hydroxylase (CYP24A1) were detected, whereas no products of CYP27B1 including 1α,25-dihydroxy-19-nor-vitamin D3 (1α,25(OH)2-19-nor-D3) were found. Furthermore, the time-dependent nuclear translocation of vitamin D receptor (VDR) and the subsequent transactivation of cyp24A1 gene in the presence of 25(OH)-19-nor-D3 were almost identical as those induced by 1α,25(OH)2-19-nor-D3. These results strongly suggest that 25(OH)-19-nor-D3 directly binds to VDR as a ligand and transports VDR into the nucleus to induce transcription of cyp24A1 gene. In addition, knock down of cyp27B1 gene did not affect the anti-proliferative activity of 25(OH)-19-nor-D3, whereas knock down of VDR attenuated the inhibitory effect. Thus, our results clearly demonstrate that the anti-proliferative activity of 25(OH)-19-nor-D3 is VDR dependent but 1α-hydroxylation independent, suggesting that 25(OH)D3 analogs such as 25(OH)-19-nor-D3 could be attractive candidates for anticancer therapy.
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- 2011
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32. Vitamin D Status, Adiposity, and Lipids in Black American and Caucasian Children
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SoJung Lee, Tai C. Chen, Javier de las Heras, Silva A. Arslanian, Kumaravel Rajakumar, and Michael F. Holick
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Male ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Adipose tissue ,Biochemistry ,Body Mass Index ,chemistry.chemical_compound ,Endocrinology ,Risk Factors ,polycyclic compounds ,Vitamin D ,Child ,Adiposity ,African american ,Vitamina d ,Vitamins ,Lipids ,Adipose Tissue ,Female ,lipids (amino acids, peptides, and proteins) ,Seasons ,Lipoproteins, HDL ,psychological phenomena and processes ,medicine.medical_specialty ,Adolescent ,Black People ,Nutritional Status ,White People ,vitamin D deficiency ,Internal medicine ,mental disorders ,medicine ,Vitamin D and neurology ,Endocrine Research ,Humans ,Obesity ,business.industry ,Cholesterol ,Puberty ,Biochemistry (medical) ,nutritional and metabolic diseases ,medicine.disease ,United States ,chemistry ,Dihydroxycholecalciferols ,Linear Models ,business ,Body mass index - Abstract
The aim of the study was to examine the relationship between vitamin D status, total and abdominal adiposity, and lipids in black and white children.Plasma 25-hydroxyvitamin D [25(OH)D], adiposity [body mass index (BMI), percentage of total body fat, visceral adipose tissue (VAT), sc adipose tissue (SAT)], and fasting lipids were assessed in healthy obese and nonobese 8- to 18-yr-old black and white children.We studied 237 children (mean ± sd age, 12.7 ± 2.2 yr; 47% black, 47% obese, and 43% male). Mean 25(OH)D concentration for the entire cohort was 19.4 ± 7.4 ng/ml. The majority of the children were vitamin D deficient [25(OH)D20 ng/ml; 73% blacks, 40% whites]. Plasma 25(OH)D was associated inversely with BMI, BMI percentile, percentage of total body fat, VAT, and SAT and positively with HDL cholesterol in the entire cohort. VAT was higher in vitamin D-deficient whites, and SAT was higher in vitamin D-deficient blacks compared with their respective vitamin D-nondeficient counterparts. Race, season, pubertal status, and VAT were independent significant predictors of 25(OH)D status.In black and white youth examined together, lower levels of 25(OH)D are associated with higher adiposity measures and lower HDL. Furthermore, vitamin D deficiency is associated with higher VAT in whites and greater SAT in blacks. Besides therapeutic interventions to correct the high rates of vitamin D deficiency in youth, benefits of vitamin D optimization on adiposity measures and lipid profile need to be explored.
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- 2011
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33. Nutritional supplementation of hop rho iso-alpha acids, berberine, vitamin D3, and vitamin K1 produces a favorable bone biomarker profile supporting healthy bone metabolism in postmenopausal women with metabolic syndrome
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Joseph J. Lamb, Veera Konda, Alex Hsi, Matthew L. Tripp, Jyh-Lurn Chang, Deanna M. Minich, Jacob Kornberg, Robert Lerman, Anuradha Desai, Tai C. Chen, Michael F. Holick, Melissa Austin, and Jeffrey S. Bland
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Vitamin ,medicine.medical_specialty ,Nutrition and Dietetics ,Bone density ,biology ,Endocrinology, Diabetes and Metabolism ,Osteoporosis ,Parathyroid hormone ,Placebo ,medicine.disease ,Bone remodeling ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,medicine ,Osteocalcin ,biology.protein ,Metabolic syndrome - Abstract
Metabolic syndrome poses additional risk for postmenopausal women who are already at risk for osteoporosis. We hypothesized that a nutritional supplement containing anti-inflammatory phytochemicals and essential bone nutrients would produce a favorable bone biomarker profile in postmenopausal women with metabolic syndrome. In this 14-week, randomized trial, 51 women were instructed to consume a modified Mediterranean-style, low-glycemic-load diet and to engage in aerobic exercise. Those in the intervention arm (n = 25) additionally received 200 mg hop rho iso-alpha acids, 100 mg berberine sulfate trihydrate, 500 IU vitamin D₃, and 500 μg vitamin K₁ twice daily. Forty-five women completed the study. Baseline nutrient intake did not differ between arms. Compared with baseline, the intervention arm exhibited an approximate 25% mean decrease (P < .001) in serum osteocalcin (indicative of bone turnover), whereas the placebo arm exhibited a 21% increase (P = .003). Serum 25-hydroxyvitamin D increased 23% (P = .001) in the intervention arm and decreased 12% (P = .03) in the placebo arm. The between-arm differences for osteocalcin and 25-hydroxyvitamin D were statistically significant. Serum insulin-like growth factor I was statistically increased in both arms, but the between-arm differences were not statistically significant. Subanalysis showed that among those in the highest tertile of baseline insulin-like growth factor I, the intervention arm exhibited a significant increase in amino-terminal propeptide of type I collagen, whereas the placebo arm showed a significant decrease at 14 weeks. Treatment with rho iso-alpha acids, berberine, vitamin D₃, and vitamin K₁ produced a more favorable bone biomarker profile indicative of healthy bone metabolism in postmenopausal women with metabolic syndrome.
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- 2011
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34. Umbilical cord plasma 25-hydroxyvitamin D concentration and immune function at birth: the Urban Environment and Childhood Asthma study
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Cynthia M. Visness, George T. O'Connor, Amy Chi, Gordon R. Bloomberg, Frank R. Witter, Diane R. Gold, James E. Gern, Peter J. Gergen, Tai C. Chen, Jeremy Wildfire, Meyer Kattan, Michael F. Holick, Rachel M. McLoughlin, and Robert A. Wood
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medicine.medical_specialty ,Pregnancy ,Calcitriol ,business.industry ,medicine.medical_treatment ,Immunology ,medicine.disease ,Umbilical cord ,respiratory tract diseases ,Steroid hormone ,medicine.anatomical_structure ,Immune system ,Endocrinology ,Internal medicine ,medicine ,Vitamin D and neurology ,Immunology and Allergy ,Young adult ,business ,Asthma ,medicine.drug - Abstract
Background Recent studies have reported conflicting data on the association between maternal intake of vitamin D during pregnancy and asthma.
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- 2011
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35. Vitamin D and Pancreatic Cancer—An Update
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Chun-Nan Yeh, Kun-Chun Chiang, and Tai C. Chen
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Cancer Research ,medicine.medical_specialty ,pancreatic cancer ,vitamin D ,Review ,Calcitriol receptor ,lcsh:RC254-282 ,Immune system ,prevention ,Internal medicine ,Pancreatic cancer ,Vitamin D and neurology ,Medicine ,vitamin D receptor ,chemoprevention ,Inhibitory effect ,adenocarcinoma ,treatment ,business.industry ,Cancer ,medicine.disease ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Endocrinology ,Oncology ,Etiology ,Cancer research ,Adenocarcinoma ,business - Abstract
The non-classical actions of vitamin D, namely anti-proliferation, pro-differentiation, immune function modulation, and anti-inflammation, have received great attention during the past decade, in particular, the potential of vitamin D analogs alone or in combination with other anticancer agents for the treatment of a variety of cancers. The association between vitamin D status and the higher incidence of many forms of cancer has suggested that vitamin D may play a role in the etiology of these types of cancer. Although it is still controversial whether this association exists for pancreatic cancer, biochemical evidence clearly indicates pancreatic cancer cells are responsive to the inhibitory effect of vitamin D and its analogs. In this review, we discuss briefly the origin and current therapy of pancreatic cancer, the history, source, metabolism and functions of vitamin D, the recent progress in the epidemiological studies of sunlight, and vitamin D status, and biochemical studies of vitamin D analogs in the prevention and treatment of pancreatic cancer.
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- 2011
36. Quantifying the vitamin D3 synthesizing potential of UVB lamps at specific distances over time
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Daniel R. Boehm, Matthew F. Campbell, Michael F. Holick, Diane Mulkerin, Debra A. Schmidt, Zhiren Lu, Mark R. Ellersieck, and Tai C. Chen
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Incandescent light bulb ,Time Factors ,Radiometer ,Artificial light ,Ultraviolet Rays ,business.industry ,Previtamin D3 ,Irradiance ,General Medicine ,In Vitro Techniques ,Biology ,Animal Welfare ,Fluorescence ,law.invention ,Mercury-vapor lamp ,chemistry.chemical_compound ,Optics ,chemistry ,law ,Animal Science and Zoology ,Least-Squares Analysis ,business ,Lighting ,Fluorescent lamp ,Cholecalciferol - Abstract
The purpose of this study was to quantify the ultraviolet B (UVB) output and in vitro previtamin D3 synthesis over time from various artificial light sources. Three incandescent lamps, T-Rex Active UVHeat 160 watt spot, T-Rex Active UVHeat 160 watt flood, and ZooMed PowerSun 160 watt flood, and two 1.2 m fluorescent lamps, Sylvania Blacklight 350 BL and ZooMed Reptisun 5.0, were studied. Total UVB irradiance and concentration of previtamin D synthesized using an in vitro ampoule model were quantified initially and at monthly intervals for 1 year. Incandescent lamps were measured at distances of 0.9 and 1.5 m while fluorescent lamps were measured at distances of 30.5 and 45.7 cm at the lamp's center, using both the radiometer and ampoules. Fluorescent lamp irradiance was also measured at the lamp's ends. Data were analyzed as a repeated measures split-plot in time using SAS with all mean differences determined using Least Squares Means. Incandescent lamp irradiance differences were seen at various distances. The UVHeat lamps had consistently higher previtamin D3 production and irradiance readings compared with the PowerSun lamp. Reptisun 5.0 was consistently higher in UVB irradiance over Sylvania BL 350 at both 30.5 and 45.7 cm. However, there were no differences when comparing conversion of 7-dehydrocholesterol to previtamin D3. Irradiance differences were detected between the centers and ends of the fluorescent lamps. Until UVB requirements for vitamin D3 synthesis in animals are determined, it is impossible to state that one light is superior to another. Zoo Biol 29:741–752, 2010. © 2010 Wiley-Liss, Inc.
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- 2010
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37. Three-step hydroxylation of vitamin D3 by a genetically engineered CYP105A1
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Shinichi Ikushiro, Ronald L. Horst, Masaki Kamakura, Miho Ohta, Tai C. Chen, Hiroshi Sugimoto, Keiko Hayashi, Yoshitsugu Shiro, Toshiyuki Sakaki, Atsushi Kittaka, and Kaori Yasuda
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Vitamin ,Stereochemistry ,Metabolite ,Hydroxylation ,Polymorphism, Single Nucleotide ,Biochemistry ,Catalysis ,Mass Spectrometry ,chemistry.chemical_compound ,Bacterial Proteins ,Cytochrome P-450 Enzyme System ,Enzyme Stability ,Escherichia coli ,Vitamin D and neurology ,Molecular Biology ,Cholecalciferol ,chemistry.chemical_classification ,biology ,Chemistry ,Genetic Variation ,Cytochrome P450 ,Active site ,Biological activity ,Cell Biology ,Recombinant Proteins ,Kinetics ,Enzyme ,biology.protein ,Streptomyces lividans ,Genetic Engineering ,Chromatography, Liquid ,Plasmids - Abstract
Our previous studies revealed that the double variant of cytochrome P450 (CYP)105A1, R73V/R84A, has a high ability to convert vitamin D(3) to its biologically active form, 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2)D(3)], suggesting the possibility for R73V/R84A to produce 1α,25(OH)(2)D(3). Because Actinomycetes, including Streptomyces, exhibit properties that have potential advantages in the synthesis of secondary metabolites of industrial and medical importance, we examined the expression of R73V/R84A in Streptomyces lividans TK23 cells under the control of the tipA promoter. As expected, the metabolites 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1α,25(OH)(2)D(3) were detected in the cell culture of the recombinant S. lividans. A large amount of 1α,25(OH)(2)D(3), the second-step metabolite of vitamin D(3), was observed, although a considerable amount of vitamin D(3) still remained in the culture. In addition, novel polar metabolites 1α,25(R),26(OH)(3)D(3) and 1α,25(S),26(OH)(3)D(3), both of which are known to have high antiproliferative activity and low calcemic activity, were observed at a ratio of 5:1. The crystal structure of the double variant with 1α,25(OH)(2)D(3) and a docking model of 1α,25(OH)(2)D(3) in its active site strongly suggest a hydrogen-bond network including the 1α-hydroxyl group, and several water molecules play an important role in the substrate-binding for 26-hydroxylation. In conclusion, we have demonstrated that R73V/R84A can catalyze hydroxylations at C25, C1 and C26 (C27) positions of vitamin D(3) to produce biologically useful compounds.
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- 2010
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38. HEALTH ASSESSMENT OF AMERICAN OYSTERCATCHERS (HAEMATOPUS PALLIATUS PALLIATUS) IN GEORGIA AND SOUTH CAROLINA
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Daphne Carlson-Bremer, Mareie Oliva, Carolyn Cray, Ellen S. Dierenfeld, Kirsten V. K. Gilardi, Tai C. Chen, Brad Winn, Terry M. Norton, Samantha E. J. Gibbs, Christine K. Johnson, Felicia J. Sanders, and Maria S. Sepúlveda
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Male ,Conservation of Natural Resources ,Food Chain ,Georgia ,Health Status ,South Carolina ,Population ,Wildlife ,Breeding ,Predation ,Charadriiformes ,Sex Factors ,Oystercatcher ,Animals ,education ,Ecosystem ,Ecology, Evolution, Behavior and Systematics ,Population Density ,education.field_of_study ,Ecology ,biology ,Bird Diseases ,Small population size ,biology.organism_classification ,Bivalvia ,Habitat destruction ,Habitat ,Threatened species ,Female - Abstract
The American Oystercatcher (Haematopus palliatus palliatus) is the only species of oystercatcher native to the Atlantic coast of North America and is restricted in distribution to intertidal shellfish beds in coastal areas. Currently, the American Oystercatcher population in South Carolina and Georgia is threatened by widespread habitat loss, resulting in low reproductive success and small population size. Oystercatchers could be an important indicator of ecosystem health because they depend on quality coastal breeding habitat and prey on bivalves, which can accumulate toxins and pathogens from the local environment. Data were collected from American Oystercatchers (n=171) captured at five sites in South Carolina and Georgia between 2001 and 2006. Iridial depigmentation was frequently noted during physical examination and was more prevalent in female birds. Female birds were larger than males on average, but ranges for weight and morphometric measurements had considerable overlap. Mean values were calculated for hematology, plasma biochemistry, and hormone levels, and prevalence of exposure to select pathogens was determined. Mercury was the only trace metal detected in blood samples. These data provide baseline health information needed for longitudinal monitoring and conservation efforts for American Oystercatchers. In addition, this study illustrates the potential use of this species as an indicator for the health of the southeastern US coastal nearshore ecosystem.
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- 2010
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39. Low 25-Hydroxyvitamin D Levels in Adolescents: Race, Season, Adiposity, Physical Activity, and Fitness
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Norman K. Pollock, Haidong Zhu, Tai C. Chen, Daniel Keeton, Inger Stallmann-Jorgensen, Michael F. Holick, B Gutin, Yanbin Dong, Karen Petty, and Ling Lan
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Male ,medicine.medical_specialty ,Waist ,Adolescent ,Physical fitness ,Physiology ,Physical exercise ,Article ,Mass Spectrometry ,White People ,vitamin D deficiency ,Body Mass Index ,Oxygen Consumption ,Internal medicine ,Prevalence ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Cardiovascular fitness ,Adiposity ,business.industry ,Vitamin D Deficiency ,medicine.disease ,Obesity ,United States ,Black or African American ,Cross-Sectional Studies ,Endocrinology ,Physical Fitness ,Pediatrics, Perinatology and Child Health ,Female ,Seasons ,business ,Body mass index ,Chromatography, Liquid - Abstract
OBJECTIVES: The objectives were to characterize the vitamin D status of black and white adolescents residing in the southeastern United States (latitude: ∼33°N) and to investigate relationships with adiposity. METHODS: Plasma 25-hydroxyvitamin D levels were measured with liquid chromatography-tandem mass spectroscopy for 559 adolescents 14 to 18 years of age (45% black and 49% female). Fat tissues, physical activity, and cardiovascular fitness also were measured. RESULTS: The overall prevalences of vitamin D insufficiency ( CONCLUSIONS: Low vitamin D status is prevalent among adolescents living in a year-round sunny climate, particularly among black youths. The relationships between 25-hydroxyvitamin D levels, adiposity, physical activity, and fitness seem to be present in adolescence.
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- 2010
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40. Widespread Vitamin D Deficiency in Urban Massachusetts Newborns and Their Mothers
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Anne Merewood, Supriya D. Mehta, Howard Bauchner, Jeffrey S. Mathieu, Tai C. Chen, Xena Grossman, and Michael F. Holick
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Adult ,Male ,Pediatrics ,medicine.medical_specialty ,Cross-sectional study ,Population ,Rickets ,vitamin D deficiency ,Cohort Studies ,Young Adult ,Vitamin D and neurology ,Humans ,Medicine ,Mass index ,Vitamin D ,education ,Maternal Welfare ,Prenatal vitamins ,education.field_of_study ,Pregnancy ,business.industry ,Infant, Newborn ,Urban Health ,Obstetrics and Gynecology ,General Medicine ,Odds ratio ,Vitamin D Deficiency ,medicine.disease ,Cross-Sectional Studies ,Massachusetts ,Pediatrics, Perinatology and Child Health ,Cohort ,Population study ,Gestation ,Female ,business ,Boston ,Cohort study - Abstract
Supplementation of milk with vitamin D virtually eliminated rickets, a disease once ubiquitous in industrialized nations in the early 20th century. In the last decade, however, several reports have indicated that vitamin D deficiency is widespread in industrialized nations, and that rickets is remerging. At present, vitamin D deficiency appears to be prevalent in women of childbearing age and young children. This retrospective cohort study examined vitamin D status in mothers and newborns in Boston and investigated factors associated with vitamin D deficiency. The study was performed between 2005 and 2007 at an urban teaching hospital with a population of primarily low-income Black and Hispanic patients. Blood samples were obtained by venipuncture from the mother and infant within 72 hours of birth. Data on potential variables associated with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] < 20 ng/mL) in mothers and infants were obtained from a questionnaire completed by the mothers and from medical records. The serum level of 25(OH)D level, the primary study outcome, was determined by competitive protein binding. A total of 458 mother/infant pairs were enrolled; after exclusions, the final study population was 376 newborns and 433 women. The median infant 25(OH)D level was 17.2 ng/mL (range, 5.0-60.8 ng/mL), with a 95% confidence interval (CI) of 16.0 to 18.8. The median maternal 25(OH)D level was 24.8 ng/mL (range, 5.0-79.2 ng/mL), with a 95% CI of 23.2 to 25.8. Vitamin D deficiency was found in 58% of the infants and 35.8% of the mothers, and severe deficiency (25[OH]D level
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- 2010
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41. Hop rho iso-alpha acids, berberine, vitamin D3 and vitamin K1 favorably impact biomarkers of bone turnover in postmenopausal women in a 14-week trial
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Deanna M. Minich, Joseph J. Lamb, Michael F. Holick, Jyh-Lurn Chang, Melissa Austin, Veera Konda, Jeffrey S. Bland, Matthew L. Tripp, Anuradha Desai, Tai C. Chen, Robert Lerman, Jacob Kornberg, Alex Hsi, and Gary Darland
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Vitamin ,medicine.medical_specialty ,Berberine ,Endocrinology, Diabetes and Metabolism ,Osteocalcin ,Osteoporosis ,Pilot Projects ,Bone remodeling ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,25-Hydroxyvitamin D 2 ,Vitamin D and neurology ,Humans ,Single-Blind Method ,Orthopedics and Sports Medicine ,Insulin-Like Growth Factor I ,Humulus ,Osteoporosis, Postmenopausal ,Calcifediol ,Cholecalciferol ,Bone Density Conservation Agents ,biology ,Plant Extracts ,business.industry ,Vitamin K 1 ,General Medicine ,Middle Aged ,medicine.disease ,Postmenopause ,chemistry ,Dietary Supplements ,biology.protein ,Female ,Bone Remodeling ,business ,Biomarkers ,Phytotherapy - Abstract
Osteoporosis is a major health issue facing postmenopausal women. Increased production of pro-inflammatory cytokines resulting from declining estrogen leads to increased bone resorption. Nutrition can have a positive impact on osteoporosis prevention and amelioration. The objective of this study was to investigate the impact of targeted phytochemicals and nutrients essential for bone health on bone turnover markers in healthy postmenopausal women. In this 14-week, single-blinded, 2-arm placebo-controlled pilot study, all women were instructed to consume a modified Mediterranean-style low-glycemic-load diet and to engage in limited aerobic exercise; 17 randomized to the placebo and 16 to the treatment arm (receiving 200 mg hop rho iso-alpha acids, 100 mg berberine sulfate trihydrate, 500 IU vitamin D(3) and 500 microg vitamin K(1), twice daily). Thirty-two women completed the study. Baseline nutrient intake did not differ between arms. At 14 weeks, the treatment arm exhibited an estimated 31% mean reduction (P = 0.02) in serum osteocalcin (a marker of bone turnover), whereas the placebo arm exhibited a 19% increase (P = 0.03) compared to baseline. Serum 25-hydroxyvitamin D (25(OH)D) increased by 13% (P = 0.24) in the treatment arm and decreased by 25% (P < 0.01) in the placebo arm. The between-arm differences for OC and 25(OH)D were statistically significant. Serum IGF-I was increased in both arms, but the increase was more significant in the treatment arm at 14 weeks (P < 0.01). Treatment with hop rho iso-alpha acids, berberine sulfate trihydrate, vitamin D(3) and vitamin K(1) produced a more favorable bone biomarker profile that supports a healthy bone metabolism.
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- 2009
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42. Relation of body fat indexes to vitamin D status and deficiency among obese adolescents
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Emily von Scheven, Anne Merewood, Carol Sweeney, William J. Klish, Michael F. Holick, Henry A. Feldman, Darrell M. Wilson, Phillip D.K. Lee, Marcia S. Wertz, Stephanie H. Abrams, Stephen E. Gitelman, Carine M. Lenders, George A. Taylor, and Tai C. Chen
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Male ,medicine.medical_specialty ,Adolescent ,Intra-Abdominal Fat ,Bone density ,Medicine (miscellaneous) ,Parathyroid hormone ,vitamin D deficiency ,Body Mass Index ,Absorptiometry, Photon ,Obesity and eating disorders ,Bone Density ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Obesity ,Vitamin D ,Tomography ,Bone mineral ,Analysis of Variance ,Nutrition and Dietetics ,Chemistry ,Vitamin D Deficiency ,medicine.disease ,Endocrinology ,Adipose Tissue ,Parathyroid Hormone ,Linear Models ,Lean body mass ,Female ,Body mass index - Abstract
Background: Data on the relation between vitamin D status and body fat indexes in adolescence are lacking. Objective: The objective was to identify factors associated with vitamin D status and deficiency in obese adolescents to further evaluate the relation of body fat indexes to vitamin D status and deficiency. Design: Data from 58 obese adolescents were obtained. Visceral adipose tissue (VAT) was measured by computed tomography. Dual-energy X-ray absorptiometry was used to measure total bone mineral content, bone mineral density, body fat mass (FM), and lean mass. Relative measures of body fat were calculated. Blood tests included measurements of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), osteocalcin, type I collagen C-telopeptide, hormones, and metabolic factors. Vitamin D deficiency was defined as 25(OH)D 65 ng/mL. Results: The mean (±SD) age of the adolescents was 14.9 ± 1.4 y; 38 (66%) were female, and 8 (14%) were black. The mean (±SD) body mass index (in kg/m2) was 36 ± 5, FM was 40.0 ± 5.5%, and VAT was 12.4 ± 4.3%. Seventeen of the adolescents were vitamin D deficient, but none had elevated PTH concentrations. Bone mineral content and bone mineral density were within 2 SDs of national standards. In a multivariate analysis, 25(OH)D decreased by 0.46 ± 0.22 ng/mL per 1% increment in FM (β ± SE, P = 0.05), whereas PTH decreased by 0.78 ± 0.29 pg/mL per 1% increment in VAT (P = 0.01). Conclusions: To the best of our knowledge, our results show for the first time that obese adolescents with 25(OH)D deficiency, but without elevated PTH concentrations, have a bone mass within the range of national standards (±2 SD). The findings provide initial evidence that the distribution of fat may be associated with vitamin D status, but this relation may be dependent on metabolic factors. This study was registered at www.clinicaltrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT00209482","term_id":"NCT00209482"}}NCT00209482, NCT00120146.
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- 2009
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43. Standard multivitamin supplementation does not improve vitamin D insufficiency after burns
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Tai C. Chen, David N. Herndon, Gordon L. Klein, Michael F. Holick, and Gabriela A. Kulp
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Male ,Vitamin ,medicine.medical_specialty ,Adolescent ,Bone density ,Diet therapy ,Endocrinology, Diabetes and Metabolism ,Parathyroid hormone ,Article ,vitamin D deficiency ,Phosphates ,chemistry.chemical_compound ,Endocrinology ,Bone Density ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Orthopedics and Sports Medicine ,Vitamin D ,Child ,Serum Albumin ,Lumbar Vertebrae ,business.industry ,Blood Proteins ,Vitamins ,General Medicine ,Vitamin D Deficiency ,medicine.disease ,Ergocalciferol ,Treatment Outcome ,chemistry ,Parathyroid Hormone ,Child, Preschool ,Dietary Supplements ,Ergocalciferols ,Calcium ,Female ,Burns ,Multivitamin ,business ,medicine.drug - Abstract
Children suffering severe burns develop progressive vitamin D deficiency because of inability of burned skin to produce normal quantities of vitamin D(3) and lack of vitamin D supplementation on discharge. Our study was designed to determine whether a daily supplement of a standard multivitamin tablet containing vitamin D(2) 400 IU (10 microg) for 6 months would raise serum levels of 25-hydroxyvitamin D [25(OH)D] to normal. We recruited eight burned children, ages 5-18, whose families were deemed reliable by the research staff. These children were given a daily multivitamin tablet in the hospital for 3 months in the presence of a member of the research staff and then given the remainder at home. At 6 months, the subjects returned for measurements of serum levels of 25(OH)D,1,25-dihydroxyvitamin D [1,25(OH)(2)D], intact parathyroid hormone (iPTH), Ca, P, albumin, and total protein as well as bone mass by dual energy X-ray absorptiometry. Serum 25(OH)D levels were compared to a group of seven age-matched burned children studied at an earlier date without the vitamin supplement but with the same method of determination of 25(OH)D at 6 months post-burn. In addition, the chewable vitamins were analyzed for vitamin D(2) content by high performance liquid chromatography. Serum concentration of 25(OH)D was 21 +/- 11(SD) ng/ml (sufficient range 30-100) with only one of the eight children having a value in the sufficient range. In comparison, the unsupplemented burn patients had mean serum 25(OH)D level of 16 +/- 7, P = 0.33 versus supplemented. Serum levels of 1,25(OH)(2)D, iPTH, Ca, P, albumin, and total protein were all normal in the supplemented group. Vitamin D(2) content of the chewable tablets after being saponified and extracted was 460 +/- 20 IU. Bone mineral content of the total body and lumbar spine, as well as lumbar spine bone density, failed to increase as expected in the supplemented group. No correlations were found between serum 25(OH)D levels and age, length of stay, percent body surface area burn or third-degree burn. Supplementation of burned children with a standard multivitamin tablet stated to contain 400 IU of vitamin D(2) failed to correct the vitamin D insufficiency.
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- 2009
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44. Restoring Vitamin D in Monitor Lizards: Exploring the Efficacy of Dietary and UVB Sources
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Brent Peavy, John E. Pinder, Ruston Hartdegen, Tai C. Chen, Gary W. Ferguson, William H. Gehrmann, Cathy Painter, and Michael F. Holick
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Vitamin ,medicine.medical_specialty ,Provitamin ,Previtamin D3 ,chemistry.chemical_element ,Half-life ,Biology ,Calcium ,chemistry.chemical_compound ,Endocrinology ,Blood serum ,chemistry ,Oral administration ,Internal medicine ,medicine ,Vitamin D and neurology - Abstract
We studied the effects of ultraviolet B (UVB) exposure or administration of dietary vitamin D3 on serum vitamin D3, serum 25-hydroxyvitamin D3 (25[OH]D), calcium, and phosphorus in juvenile black-throated monitor lizards (Varanus albigularis) deprived of all sources of vitamin D for 87 days. Deprivation resulted in significant decreases of circulating levels of 25(OH)D (25–35%), vitamin D3 (73–76%), calcium (6%), and phosphorus (16%). The half-life of circulating 25(OH)D during deprivation was estimated to be from 128–139 days. After deprivation, eight monitors were given a single dose of UVB from exposure for 10–20 minutes to a Spectroline UVB lamp. The dose resulted in an average of 14.2% conversion of provitamin D3 to previtamin D3 and photoproducts within in vitro models. When administered once every week for 92 days, the dose failed to significantly modify the decline of serum 25(OH)D; however, the decline of vitamin D3 seemed to level off. The overall effect of the UVB dosing was weak, and ...
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- 2009
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45. Plasma 25-Hydroxyvitamin D Levels in Young Children Undergoing Placement of Tympanostomy Tubes
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Richard D. Shindledecker, Linda A. Linday, Tai C. Chen, Jay N. Dolitsky, and Michael F. Holick
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Male ,Vitamin ,medicine.medical_specialty ,Pediatrics ,medicine.medical_treatment ,Rickets ,Gastroenterology ,chemistry.chemical_compound ,Internal medicine ,Blood plasma ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Tympanostomy tube ,Child ,Otitis Media with Effusion ,business.industry ,Infant ,General Medicine ,Prognosis ,medicine.disease ,Middle Ear Ventilation ,Eicosapentaenoic acid ,Ambulatory Surgical Procedures ,Otorhinolaryngology ,chemistry ,El Niño ,Child, Preschool ,Ambulatory ,Female ,business ,Biomarkers - Abstract
Objectives: We report the plasma 25-hydroxyvitamin D [25(OH)D] levels of 16 young children who were undergoing ambulatory surgery for placement of tympanostomy tubes. Methods: We previously obtained blood samples from young children who were undergoing ambulatory surgery and reported that they had lower blood levels than adults of eicosapentaenoic acid (an omega-3 fatty acid), vitamin A, and selenium. Plasma frozen continuously at −80°C was available from 16 subjects who were undergoing placement of tympanostomy tubes. Results: The mean (±SD) age of the patients was 3.7 ± 1.6 years (median, 2.9 years; range, 1.9 to 7.4 years). Sixty-two percent were male; half were white, and half were Hispanic. Sixty-two percent were private patients; the parents reported that half were taking vitamin supplements. None had a history of rickets. None had 25(OH)D levels less than 10 ng/mL; 50% had 25(OH)D levels less than 20 ng/mL (deficient in adults); another 31% had levels from 21 to 29 ng/mL (insufficient in adults). Conclusions: Vitamin D is essential for the production of endogenous antimicrobial peptides, and has been linked to seasonal, epidemic influenza A. However, the level of 25(OH)D needed to prevent infection with various human pathogens has not been defined. In view of increasing bacterial resistance and emerging new pathogens, further research on the relationship of infection to 25(OH)D and other nutritional factors is warranted.
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- 2008
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46. Serum 25-hydroxyvitamin D and bone mineral density among Hispanic men
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Andre B. Araujo, John B. McKinlay, Michael F. Holick, Tai C. Chen, Thomas G. Travison, and Gretchen R. Esche
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Adult ,Male ,Risk ,Gerontology ,medicine.medical_specialty ,Bone density ,Cross-sectional study ,Endocrinology, Diabetes and Metabolism ,Article ,vitamin D deficiency ,Fractures, Bone ,Bone Density ,Epidemiology ,Prevalence ,Vitamin D and neurology ,Humans ,Medicine ,Vitamin D ,Aged ,Bone mineral ,business.industry ,Hispanic or Latino ,Middle Aged ,Vitamin D Deficiency ,medicine.disease ,Cross-Sectional Studies ,Logistic Models ,Massachusetts ,Population study ,business ,Body mass index ,Biomarkers ,Demography - Abstract
There are few data on the skeletal health of Hispanic men. We observed differences in vitamin D deficiency and low BMD between Hispanic ethnic subgroups that persisted with adjustment for risk factors. Our data indicate a substantial burden of low BMD and vitamin D deficiency among Hispanic men. Disparities within ethnic groups are generally ignored, but in evolving populations they may have implications for public health. We examined ethnic variation in serum 25-hydroxyvitamin D [25(OH)D] and bone mineral density (BMD) among Hispanic American men. Three hundred and fifty-eight Hispanic males 30 to 79 years of age were studied. Logistic regression models assessed variation in odds of vitamin D deficiency (
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- 2008
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47. 25-Hydroxyvitamin D, cholesterol, and ultraviolet irradiation
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Mitchell A. Watsky, Nathaniel K. Wilkin, Karl T. Weber, Thomas A. Hughes, E. William Rosenberg, Tai C. Chen, Laura D Carbone, Syamal K. Bhattacharya, Michael F. Holick, John C. Dowdy, Elizabeth A. Tolley, Robert M. Sayre, and Karen D. Barrow
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Adult ,Male ,medicine.medical_specialty ,Apolipoprotein B ,Ultraviolet Rays ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Cardiovascular health ,vitamin D deficiency ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Apolipoprotein A-I ,biology ,Chemistry ,Cholesterol ,Cholesterol, HDL ,Cholesterol, LDL ,medicine.disease ,Steroid hormone ,biology.protein ,Ultraviolet irradiation ,Female ,lipids (amino acids, peptides, and proteins) ,Lipoprotein(a) ,Lipoprotein - Abstract
Vitamin D deficiency may have implications for cardiovascular health. The purpose of this study was to determine the relationship of 25-hydroxyvitamin D (25[OH]D) to cholesterol and lipoprotein particles and to determine whether increasing 25(OH)D through ultraviolet (UV) irradiation impacted on these parameters in healthy young men and women. This was a randomized trial of 51 adults exposed to suberythemal doses of whole-body irradiation using UV lamps that emitted UV-A and UV-B radiation, compared with a control group, twice weekly for 12 weeks. 25-Hydroxyvitamin D, cholesterol, and lipoprotein subfractions were measured at baseline and after 12 weeks. There was a significant (P < .03) positive association between 25(OH)D and apolipoprotein A-I (Apo A-I) and lipoprotein A-I (Lp A-I). The ratio of low-density lipoprotein to high-density lipoprotein was significantly (P < or = .044) negatively correlated with 25(OH)D levels. The levels of 25(OH)D increased significantly in the treated compared with control group (P < .05). Overall, there were no significant differences between the treated and control groups in any lipoproteins or apolipoproteins after administration of UV irradiation. Subgroup analysis for Apo A-II confined to those with 25(OH)D insufficiency (25[OH]D
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- 2008
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48. Kinetic Studies of 25-Hydroxy-19-nor-vitamin D3 and 1α,25-Dihydroxy-19-nor-vitamin D3 Hydroxylation by CYP27B1 and CYP24A1
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Midori A. Arai, Naoko Urushino, Keiko Yamamoto, Masaki Kamakura, Sachie Nakabayashi, Shinichi Ikushiro, Miho Ohta, Toshiyuki Sakaki, Keiko Hayashi, Atsushi Kittaka, Tai C. Chen, and Shigeaki Kato
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Male ,Models, Molecular ,Vitamin ,Stereochemistry ,Metabolite ,Kinetics ,Pharmaceutical Science ,Alpha (ethology) ,Thymus Gland ,Hydroxylation ,Calcitriol receptor ,Cell Line ,chemistry.chemical_compound ,Calcitriol ,Cytochrome P-450 Enzyme System ,CYP24A1 ,Escherichia coli ,Animals ,Humans ,Vitamin D3 24-Hydroxylase ,Chromatography, High Pressure Liquid ,Cell Proliferation ,Cholecalciferol ,25-Hydroxyvitamin D3 1-alpha-Hydroxylase ,Pharmacology ,Carbon Monoxide ,Prostate ,In vitro ,chemistry ,Steroid Hydroxylases ,Cattle ,Plasmids - Abstract
Our previous study demonstrated that 25-hydroxy-19-nor-vitamin D(3) [25(OH)-19-nor-D(3)] inhibited the proliferation of immortalized noncancerous PZ-HPV-7 prostate cells similar to 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)], suggesting that 25(OH)-19-nor-D(3) might be converted to 1 alpha,25-dihydroxy-19-nor-vitamin D(3) [1 alpha,25(OH)(2)-19-nor-D(3)] by CYP27B1 before exerting its antiproliferative activity. Using an in vitro cell-free model to study the kinetics of CYP27B1-dependent 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) and 25-hydroxyvitamin D(3) [25(OH)D(3)] and CYP24A1-dependent hydroxylation of 1 alpha,25(OH)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3), we found that k(cat)/K(m) for 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) was less than 0.1% of that for 25(OH)D(3), and the k(cat)/K(m) value for 24-hydroxylation was not significantly different between 1 alpha,25(OH)(2)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3). The data suggest a much slower formation and a similar rate of degradation of 1 alpha,25(OH)(2)-19-nor-D(3) compared with 1 alpha,25(OH)(2)D(3). We then analyzed the metabolites of 25(OH)D(3) and 25(OH)-19-nor-D(3) in PZ-HPV-7 cells by high-performance liquid chromatography. We found that a peak that comigrated with 1 alpha,25(OH)(2)D(3) was detected in cells incubated with 25(OH)D(3), whereas no 1 alpha,25(OH)(2)-19-nor-D(3) was detected in cells incubated with 25(OH)-19-nor-D(3). Thus, the present results do not support our previous hypothesis that 25(OH)-19-nor-D(3) is converted to 1 alpha,25(OH)(2)-19-nor-D(3) by CYP27B1 in prostate cells to inhibit cell proliferation. We hypothesize that 25(OH)-19-nor-D(3) by itself may have a novel mechanism to activate vitamin D receptor or it is metabolized in prostate cells to an unknown metabolite with antiproliferative activity without 1 alpha-hydroxylation. Thus, the results suggest that 25(OH)-19-nor-D(3) has potential as an attractive agent for prostate cancer therapy.
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- 2007
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49. High-Throughput System for Analyzing Ligand-Induced Cofactor Recruitment by Vitamin D Receptor
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Ken-ichi Takeyama, Midori A. Arai, Shigeaki Kato, Tai C. Chen, Atsushi Kittaka, and Saya Ito
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Vitamin ,VDR binding ,Drug Evaluation, Preclinical ,Biomedical Engineering ,Pharmaceutical Science ,Bioengineering ,Ligands ,Calcitriol receptor ,Cofactor ,Nuclear Receptor Coactivator 2 ,chemistry.chemical_compound ,Nuclear Receptor Coactivator 1 ,Cell Line, Tumor ,Formaldehyde ,Coactivator ,Vitamin D and neurology ,Humans ,Coenzyme A ,Vitamin D ,Histone Acetyltransferases ,Pharmacology ,biology ,Chemistry ,Organic Chemistry ,Biological activity ,Carbocyanines ,Ligand (biochemistry) ,Biochemistry ,biology.protein ,Receptors, Calcitriol ,Transcription Factors ,Biotechnology - Abstract
A high-throughput screening system for analyzing small molecule-induced coactivator (CoA) recruitment by the vitamin D receptor (VDR) has been developed. The vitamin D-induced protein-protein interactions between VDR and fluorophore (Cy3 or Cy5)-labeled TIF2 or SRC-1 were successfully detected by using a new HCHO fixing method of the protein complex on microplates. The results obtained from this screening of our synthetic vitamin D analogues suggest that the CoA-recruiting activities play an important role in determining the biological activity of various vitamin D analogues and explain the discrepancies between the VDR binding affinity and their biological activity.
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- 2007
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50. Treatment of low-risk myelodysplastic syndromes with high-dose daily oral cholecalciferol (2000–4000 IU vitamin D3)
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Gary G. Schwartz, David D. Hurd, S Cambra, Tai C. Chen, Richard P. McQuellon, Istvan Molnar, N. Stark, Bayard L. Powell, Michael F. Holick, Julia M. Cruz, James Lovato, and Jeffrey Mathieu
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Male ,musculoskeletal diseases ,Cancer Research ,medicine.medical_specialty ,Pediatrics ,Administration, Oral ,Vitamin d 3 ,chemistry.chemical_compound ,Quality of life ,Internal medicine ,polycyclic compounds ,Humans ,Medicine ,Aged ,Cholecalciferol ,Aged, 80 and over ,business.industry ,Myelodysplastic syndromes ,Hematology ,Middle Aged ,medicine.disease ,Endocrinology ,Oncology ,chemistry ,Myelodysplastic Syndromes ,Quality of Life ,Female ,lipids (amino acids, peptides, and proteins) ,business - Abstract
Treatment of low-risk myelodysplastic syndromes with high-dose daily oral cholecalciferol (2000–4000 IU vitamin D 3 )
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- 2007
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