130 results on '"Mika Takahashi"'
Search Results
52. Efficient removal of sulfide following integration of multiple copies of the sulfide-quinone oxidoreductase gene (sqr) into the Escherichia coli chromosome
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Ikuko Yamaguchi, Mika Takahashi, Shigeki Kobayashi, and Hiroomi Shibata
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Rhodobacter ,biology ,lac operon ,Bioengineering ,biology.organism_classification ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Molecular biology ,Enterobacteriaceae ,law.invention ,Plasmid ,law ,Recombinant DNA ,medicine ,Gene ,Escherichia coli ,Biotechnology ,Southern blot - Abstract
For the oxidation and removal of hydrogen sulfide, which causes an offensive odor from the contents of animal intestines, recombinant strains of Escherichia coli were constructed. The sulfide-quinone oxidoreductase gene (sqr) from Rhodobacter capsulatus was integrated in low copy numbers into the chromosome of Escherichia coli W3110. Multiple copies of sqr on plasmids were also delivered into the cytoplasm of the same strain. The sqr genes were homologously transducted onto the chromosomal lacZ region and their existence there was verified by Southern blot analysis. Sulfide oxidation in a chemical medium effectively increased for the recombinant strains which carried 2 approximately 3 copies of sqr under the control of the lac or tac promoter in the chromosome, and also for strains which carried 10 copies of sqr under the control of the lac or tac promoter on plasmids. In both types of recombinant, the tac promoter was more effective for SQR expression than the lac promoter. Construction of a recombinant with 3 copies of sqr under the control of the tac promoter in the chromosome was unsuccessful. In recombinants with SQR activity lower than 700 nmol/mg cell protein/min, oxygen consumption increased proportionally to SQR activity. An elevation in SQR activity in this range resulted in an increase in oxygen consumption and a decrease in sulfide concentration. When the recombinant cells were cultured until the 160th generation, WL2, WL3 and WT2, which carried 2, 3 and 2 copies of sqr in the chromosome, respectively, retained SQR activity similar to that of the first generation. For WL300 and WT20 which carried multi-copies of sqr in plasmids SQR activity was undetectable. The recombinant with 2 copies of sqr in the chromosome regulated by the tac promoter was most suitable for sulfide oxidation and growth of the cells.
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- 2001
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53. Studies on the carcinogenicity of potassium iodide in F344 rats
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Kazuo Yasuhara, Hiroshi Onodera, Mika Takahashi, Shimo T, Takegawa K, Kunitoshi Mitsumori, K. Kitaura, and Masao Hirose
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Male ,medicine.medical_specialty ,Carcinogenicity Tests ,chemistry.chemical_element ,Toxicology ,Iodine ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,Thyroid Neoplasms ,Chronic toxicity ,Carcinogen ,Dose-Response Relationship, Drug ,Salivary gland ,Thyroid ,Potassium Iodide ,General Medicine ,Salivary Gland Neoplasms ,Rats, Inbred F344 ,Rats ,Dose–response relationship ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Nitrosamine ,Toxicity ,Carcinogens ,Carcinoma, Squamous Cell ,Female ,Food Science - Abstract
A chronic toxicity and carcinogenicity study, in which male and female F344/DuCrj rats were given potassium iodide (KI) in the drinking water at concentrations of 0, 10, 100 or 1000 ppm for 104 weeks, and a two-stage carcinogenicity study of application at 0 or 1000 ppm for 83 weeks following a single injection of N-bis(2-hydroxypropyl)nitrosamine (DHPN), were conducted. In the former, squamous cell carcinomas were induced in the salivary glands of the 1000 ppm group, but no tumors were observed in the thyroid. In the two-stage carcinogenicity study, thyroidal weights and the incidence of thyroid tumors derived from the follicular epithelium were significantly increased in the DHPN+KI as compared with the DHPN alone group. The results of our studies suggest that excess KI has a thyroid tumor-promoting effect, but KI per se does not induce thyroid tumors in rats. In the salivary gland, KI was suggested to have carcinogenic potential via an epigenetic mechanism, only active at a high dose.
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- 2000
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54. Lack of carcinogenicity of gardenia blue colour given chronically in the diet to F344 rats
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Takako Ikeda, M Hirose, K Kasahara, Mika Takahashi, Fumio Furukawa, Takayoshi Imazawa, and A. Nishikawa
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Male ,Carcinogenicity Tests ,Administration, Oral ,Physiology ,Gardenia jasminoides ,Toxicology ,Glucosides ,Oral administration ,Animals ,Iridoids ,Survival rate ,Carcinogen ,Pyrans ,Dose-Response Relationship, Drug ,biology ,Traditional medicine ,Plant Extracts ,Incidence (epidemiology) ,Body Weight ,Neoplasms, Experimental ,Organ Size ,General Medicine ,biology.organism_classification ,Rats, Inbred F344 ,Rats ,Survival Rate ,Dose–response relationship ,Blood ,Gardenia ,Toxicity ,Female ,Food Science - Abstract
The carcinogenicity of gardenia blue colour was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the material at dietary doses of 0 (control), 2.5 or 5% for 104 weeks and then sacrificed. The doses were selected on the basis of results from a 13-week subchronic toxicity study. A slight increase in relative organ weights of the left lung was observed in male rats of the 5% group. However, no significant differences between the control and treated groups were noted with regard to clinical signs, mortality and haematological findings. A variety of tumours developed in all groups, including the controls, but all were histologically similar to those known to occur spontaneously in F344 rats, and no statistically significant increase in the incidence of any type of neoplastic lesion was found for either sex in the treated groups. Thus, it was concluded that, under the present experimental conditions, gardenia blue colour is not carcinogenic in F344 rats.
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- 2000
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55. Lack of carcinogenicity and increased survival in F344 rats treated with 5-fluorouracil for 2 years
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Kazuhiro Toyoda, Chikako Uneyama, H. Sato, Mika Takahashi, Makoto Shibutani, Y. Hayashi, and Masao Hirose
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medicine.medical_specialty ,Pituitary gland ,Adenoma ,Incidence (epidemiology) ,General Medicine ,Biology ,Toxicology ,medicine.disease ,Endocrinology ,medicine.anatomical_structure ,Oral administration ,Fluorouracil ,Internal medicine ,Toxicity ,medicine ,medicine.symptom ,Weight gain ,Carcinogen ,Food Science ,medicine.drug - Abstract
The carcinogenicity of 5-fluorouracil (5-FU), a compound employed as an antineoplastic drug, was investigated in F344 rats of both sexes. 5-FU was administered to groups of 50 male and 50 female rats ad lib. for 104 weeks, added to drinking water at concentrations of 0 (control), 62 and 125 ppm, these dose levels being selected on the basis of results of a 13-week subchronic toxicity study. Body weight gains were slightly depressed in the 125 ppm group of both sexes. While not statistically significant in females, final survival rates at week 111 in the 125 ppm group of both sexes were higher than those in the control group, suggesting an ability of 5-FU to prolong the lifespan. Histopathologically, a decreased incidence of islet cell adenomas in males and increased incidences of pituitary gland adenomas and pheochromocytomas in females were observed in the 62 ppm group without dose dependence. There was no significant induction of any other neoplastic or non-neoplastic lesions. These results indicate a lack of carcinogenicity of 5-FU under the present experimental conditions using rats.
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- 2000
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56. Influence on Cardiac Autonomic Function of Repeated Exposures to Air-Conditioned Environment in Summer
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Mika Takahashi, Yutaka Tochihara, and Hikaru Enomoto-Koshimizu
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Air cooling ,Autonomic function ,Meteorology ,Environmental science ,Temperature difference ,R-R Interval - Published
- 1999
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57. Suppressive effects of josamycin on the development of altered liver cell foci and chronic nephropathy in a carcinogenicity study
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A. Nishikawa, Takako Ikeda, Mika Takahashi, Fumio Furukawa, Tanakamaru Z, S. Ikezaki, Takayoshi Imazawa, K Kasahara, and H Takagi
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Male ,Pathology ,medicine.medical_specialty ,Josamycin ,Physiology ,Biology ,Kidney ,Toxicology ,Nephropathy ,Random Allocation ,Neoplasms ,medicine ,Animals ,Carcinogen ,Antibacterial agent ,Dose-Response Relationship, Drug ,Incidence ,Liver cell ,Body Weight ,Heart ,Organ Size ,General Medicine ,medicine.disease ,Rats, Inbred F344 ,Anti-Bacterial Agents ,Rats ,Dose–response relationship ,medicine.anatomical_structure ,Liver ,Toxicity ,Female ,Food Science ,medicine.drug - Abstract
The carcinogenicity of josamycin was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the compound in their diet at concentrations of 0 (control), 1.25 or 2.5% for 104-weeks; these dose levels were selected on the basis of the results of a subchronic study, in which animals rather rejected 5% josamycin. All surviving rats were killed at wk 106. A variety of tumours developed in all groups, including the control group, but all the neoplastic lesions were histologically similar to those known to occur spontaneously in this strain of rats, and no statistically significant increase in the incidence of any tumour was found in the treated groups of either sex. Interestingly, the josamycin treatment significantly reduced the development of altered liver cell foci and chronic nephropathy in a dose-dependent manner. Thus, it was concluded that, under the present experimental conditions, josamycin is not carcinogenic in F344 rats.
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- 1999
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58. Liver tumour-promoting effects of oxfendazole in rats
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Hiroshi Onodera, Mika Takahashi, Takayoshi Imazawa, Chikako Uneyama, T. Shoda, Tomoyuki Watanabe, Kazuo Yasuhara, Kunitoshi Mitsumori, and Takegawa K
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Male ,medicine.medical_specialty ,Oxfendazole ,medicine.medical_treatment ,Administration, Oral ,Cell Count ,Biology ,Toxicology ,Connexins ,Muscle hypertrophy ,chemistry.chemical_compound ,Liver Neoplasms, Experimental ,Cytochrome P-450 Enzyme System ,Internal medicine ,medicine ,Animals ,Diethylnitrosamine ,Anthelmintic ,education ,Saline ,Glutathione Transferase ,Anthelmintics ,Organelles ,education.field_of_study ,Cocarcinogenesis ,General Medicine ,Glutathione ,Rats, Inbred F344 ,Rats ,Endocrinology ,medicine.anatomical_structure ,Liver ,chemistry ,Enzyme Induction ,Hepatocyte ,Toxicity ,Carcinogens ,Connexin 32 ,Benzimidazoles ,Food Science ,medicine.drug - Abstract
To examine whether oxfendazole has tumour-promoting activity, a total of 100 male Fisher 344 rats were initiated with a single ip injection of 100 mg/kg of diethylnitrosamine (DEN) or given saline vehicle alone and starting 1 wk later given diet containing 500, 250, 100, 10 or 0 ppm of oxfendazole for 8 wk. Sub-groups of five rats each from the DEN plus 250 and 0 ppm groups were killed after wk 1 of oxfendazole treatment and the remaining animals at wk 8. At the termination relative liver weights were significantly increased in the DEN-initiated and non-initiated groups treated with 250 ppm and 100 ppm or more, respectively, compared with the corresponding controls values. Light microscopical examination showed centrilobular hepatocellular hypertrophy in all animals receiving 100 ppm or more. Electron microscopy also revealed marked increases in smooth endoplasmic reticulum in hepatocytes of the DEN plus 500 ppm group. Furthermore, induction of cytochrome P-450 (CYP) 1A1/2, 2B1/2 or 4A1 was observed in the DEN plus 100 ppm group, that of CYP 1A1/2 being most marked. A similar change in CYP 1A1/2 was seen in the DEN plus 10 ppm group. The numbers and areas of connexin 32 (Cx32)-positive spots per hepatocyte were also significantly decreased in a dose-dependent manner. Similar changes in liver weights, P-450 isozymes and Cx32 immunohistochemistry were already evident in the DEN plus 250 ppm group at wk 1. The number of placental form glutathione S-transferase positive single cells was significantly increased in the DEN-initiated groups treated with 250 ppm or more. The results therefore strongly suggest that oxfendazole exerts liver tumour promotion potential.
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- 1997
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59. Assessment of the carcinogenicity of stevioside in F344 rats
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Kazuhiro Toyoda, Chikako Uneyama, T. Shoda, K. Takada, Mika Takahashi, and H. Matsui
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Male ,medicine.medical_specialty ,Carcinogenicity Tests ,F344 rats ,Administration, Oral ,Biology ,Toxicology ,Body weight ,Nephropathy ,Eating ,Glucosides ,Internal medicine ,medicine ,Animals ,Stevioside ,Survival rate ,Carcinogen ,Terpenes ,Incidence (epidemiology) ,Body Weight ,Neoplasms, Experimental ,Organ Size ,General Medicine ,medicine.disease ,Rats, Inbred F344 ,Rats ,Survival Rate ,Endocrinology ,Sweetening Agents ,Toxicity ,Female ,Kidney Diseases ,Diterpenes ,Diterpenes, Kaurane ,Food Science - Abstract
The carcinogenic potential of stevioside, a compound that is used as a sweetener for food and drink, was examined in F344 rats of both sexes. Stevioside was added to powdered diet at concentrations of 0 (control), 2.5 and 5%. The doses were selected on the basis of results from a 13-wk subchronic toxicity study and administered to groups of 50 male and 50 female rats ad lib. for 104 wk. All surviving rats were killed at wk 108. Body weight gains were slightly depressed in line with the dose of stevioside, in both sexes, and a significant decrease in the final survival rate was observed for the 5% treated males. Histopathologically, however, there was no significantly altered development of neoplastic or non-neoplastic lesions attributable to the stevioside treatment in any organ or tissue, except for a decreased incidence of mammary adenomas in females and a reduced severity of chronic nephropathy in males. It is concluded that stevioside is not carcinogenic in F344 rats under the experimental conditions described.
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- 1997
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60. Lack of carcinogenicity of cyanoguanidine in F344 rats
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Mika Takahashi, Kunitoshi Mitsumori, Kazuo Yasuhara, K. Kitaura, Shimo T, and Hiroshi Onodera
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Male ,Lesion type ,Carcinogenicity Tests ,F344 rats ,Administration, Oral ,Physiology ,Toxicology ,Body weight ,Guanidines ,Eating ,Neoplasms ,medicine ,Animals ,Survival rate ,Carcinogen ,Kidney ,Chemistry ,Body Weight ,General Medicine ,Rats, Inbred F344 ,Treatment period ,Rats ,Survival Rate ,medicine.anatomical_structure ,Toxicity ,Female ,Food Science - Abstract
The carcinogenicity of cyanoguanidine, a compound used in the production of melamine, guanidine salts and guanamine derivatives, was examined in male and female Fischer 344 rats fed CRF-1 pulverized diets containing 0, 2.5 and 5% cyanoguanidine for up to 2 yr. The rats were randomly allocated to three groups, each consisting of 50 males and 50 females. The mean body weight gains in both sexes of the 5% group and in females of the 2.5% group were significantly lower than the control values after wk 1 of treatment. No other signs of toxicity were seen in any of the rats throughout the treatment period. Histopathologically, various tumours developed in all groups, including the control group, but these were all similar to those known to occur spontaneously in this strain of rats, and no toxicologically significant increase was found for any lesion type in the treated groups. On the basis of these results, it is concluded that cyanoguanidine exerts no carcinogenic potential in F344 rats when administered for up to 2 yr under the conditions of the present study.
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- 1997
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61. Repeated dose and reproductive/developmental toxicity of perfluorododecanoic acid in rats
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Hina, Kato, Sakiko, Fujii, Mika, Takahashi, Mariko, Matsumoto, Mutsuko, Hirata-Koizumi, Atsushi, Ono, and Akihiko, Hirose
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Male ,Fluorocarbons ,No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,Reproduction ,Lauric Acids ,Hypertrophy ,Spermatozoa ,Rats ,Necrosis ,Liver ,Maternal Exposure ,Pregnancy ,Paternal Exposure ,Animals ,Environmental Pollutants ,Female - Abstract
Perfluoroalkyl carboxylic acids (PFCAs) are a series of environmental contaminants that have received attention because of their possible adverse effects on wildlife and human health. Although many toxicological studies have been performed on perfluorooctanoic acid with carbon chain length C8, available toxicity data on PFCAs with longer chains are still insufficient to evaluate their hazard. A combined repeated dose and reproductive/developmental toxicity screening study for perfluorododecanoic acid (PFDoA; C12) was conducted in accordance with OECD guideline 422 to fill these toxicity data gaps. PFDoA was administered by gavage to male and female rats at 0.1, 0.5, or 2.5 mg/kg/day. The administration of PFDoA at 0.5 and 2.5 mg/kg/day for 42-47 days mainly affected the liver, in which hypertrophy, necrosis, and inflammatory cholestasis were noted. Body weight gain was markedly inhibited in the 2.5 mg/kg/day group, and a decrease in hematopoiesis in the bone marrow and atrophic changes in the spleen, thymus, and adrenal gland were also observed. Regarding reproductive/developmental toxicity, various histopathological changes, including decreased spermatid and spermatozoa counts, were observed in the male reproductive organs, while continuous diestrous was observed in the females of the 2.5 mg/kg/day group. Seven of twelve females receiving 2.5 mg/kg/day died during late pregnancy while four other females in this group did not deliver live pups. No reproductive or developmental parameters changed at 0.1 or 0.5 mg/kg/day. Based on these results, the NOAELs of PFDoA were concluded to be 0.1 mg/kg/day for repeated dose toxicity and 0.5 mg/kg/day for reproductive/developmental toxicity.
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- 2013
62. Isolation and expression of rainbow trout (Oncorhynchus mykiss) ovarian cDNA encoding 3β-hydroxysteroid dehydrogenase/Δ(5-4)-isomerase
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Noriyoshi Sakai, Minoru Tanaka, Yoshitaka Nagahama, Mika Takahashi, and Shinji Adachi
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chemistry.chemical_classification ,Cloning ,endocrine system ,Physiology ,cDNA library ,General Medicine ,Aquatic Science ,Biology ,Oocyte ,Biochemistry ,Molecular biology ,medicine.anatomical_structure ,Enzyme ,chemistry ,Complementary DNA ,medicine ,Rainbow trout ,Ovarian follicle ,Clone (B-cell biology) - Abstract
A distinct shift in steroidogenesis from testosterone to 17α-hydroxyprogesterone occurs in the salmonid ovarian thecal cell layers immediately prior to oocyte maturation, and is a prerequisite for the production of 17α,20β-dihydroxy-4-pregnen-3-one (maturation-inducing hormone of salmonid fishes) by granulosa cells during oocyte maturation. 17α-Hydroxylase/17,20-lyase cytochrome P-450 (P-45017α) and 3β-hydroxysteroid dehydrogenase/Δ(5-4)-isomerase (3β-HSD) are the two major steroidogenic enzymes involved in the production of 17α-hydroxyprogesterone and testosterone. Using mammalian cDNA probes, we isolated and characterized full-length cDNAs encoding these two enzymes from a rainbow trout (Oncorhynchus mykiss) ovarian thecal cell cDNA library. The cloning of 2.4-kilobase cDNA encoding P-45017α and transient expression of this clone in nonsteroidogenic monkey kidney tumor COS-1 cells have recently been reported (Sakai et al. 1992). We have isolated a 1.4-kilobase cDNA which is hybridized to the mammalian 3β-HSD cDNAs. Expression of this cDNA in COS-1 cells led to the production of an enzyme which is capable of converting dehydroepiandrosterone to androstenedione. In this study, enzymatic activities and expression of rainbow trout ovarian P-45017α and 3β-HSD are discussed in relation of the steroidogenic shift occurring in the ovarian follicle layers.
- Published
- 2013
63. Efficacy and Safety of Enoxaparin for Preventing Venous Thromboembolic Events following Urologic Laparoscopic Surgery
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Fuminori Sato, Mayuka Shinohara, Mika Takahashi, Takeo Nomura, Tomoya Oribe, Kazunori Iwasaki, Hiromitsu Mimata, Yuko Fukuda, and Shinsuke Mizoguchi
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Laparoscopic surgery ,Prothrombin time ,medicine.medical_specialty ,medicine.diagnostic_test ,Article Subject ,business.industry ,medicine.medical_treatment ,medicine.disease ,Surgery ,Pulmonary embolism ,Clinical Study ,Medicine ,In patient ,business ,Adverse effect ,Venous thromboembolism ,Normal range ,Partial thromboplastin time - Abstract
There is a paucity of definitive evidence that supports the use of enoxaparin to prevent venous thromboembolism (VTE) after urologic laparoscopic surgery. The purpose of this study was to evaluate the efficacy and safety of postoperative subcutaneous enoxaparin injection in patients who underwent urologic laparoscopic surgery. A total of 63 patients were evaluated from June 2010 to December 2012. All patients received postoperative prophylaxis with enoxaparin (2000 IU twice daily for 5 days). None of the patients treated with enoxaparin developed symptomatic VTE, but two cases (3.2%) of pulmonary embolism were noted before initial enoxaparin administration. Statistically significant differences were observed between the prothrombin time (PT) and activated partial thromboplastin time (APTT) values and D-dimer levels obtained at baseline and on day 7 after surgery; however, the PT and APTT values did not exceed the normal range. In addition, signs of any adverse events were not encountered in any of the patients treated with enoxaparin. The use of enoxaparin immediately after a surgery may confer valuable thromboprophylaxis benefits for urologic laparoscopic surgery.
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- 2013
64. Generation of App knock-in mice reveals deletion mutations protective against Alzheimer’s diseaselike pathology.
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Kenichi Nagata, Mika Takahashi, Yukio Matsuba, Fumi Okuyama-Uchimura, Kaori Sato, Shoko Hashimoto, Takashi Saito, and Saido, Takaomi C.
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Although, a number of pathogenic mutations have been found for Alzheimer’s disease (AD), only one protective mutation has been identified so far in humans. Here we identify possible protective deletion mutations in the 3′-UTR of the amyloid precursor protein (App) gene in mice. We use an App knock-in mouse model carrying a humanized Aβ sequence and three AD mutations in the endogenous App gene. Genome editing of the model zygotes using multiple combinations of CRISPR/Cas9 tools produces genetically mosaic animals with various App 3′-UTR deletions. Depending on the editing efficiency, the 3′-UTR disruption mitigates the Aβ pathology development through transcriptional and translational regulation of APP expression. Notably, an App knock-in mouse with a 34-bp deletion in a 52-bp regulatory element adjacent to the stop codon shows a substantial reduction in Aβ pathology. Further functional characterization of the identified element should provide deeper understanding of the pathogenic mechanisms of AD. [ABSTRACT FROM AUTHOR]
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- 2018
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65. Long-term toxicity/carcinogenicity study of l-histidine monohydrochloride in F344 rats
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Enami T, Mika Takahashi, Takayoshi Imazawa, Mitsui M, Tanakamaru Z, In-Seon Lee, S. Ikezaki, Fumio Furukawa, A. Nishikawa, and H C Kim
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Male ,medicine.medical_specialty ,F344 rats ,Administration, Oral ,Biology ,Weight Gain ,Toxicology ,Eating ,Random Allocation ,Neoplasms ,Internal medicine ,Adrenal Glands ,medicine ,Animals ,Histidine ,Lung ,Essential amino acid ,Carcinogen ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,Sperm granuloma ,Brain ,Organ Size ,General Medicine ,Epididymis ,Rats, Inbred F344 ,Blood Cell Count ,Rats ,Specific Pathogen-Free Organisms ,Dose–response relationship ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Toxicity ,Female ,Food Science - Abstract
The long-term toxicity and carcinogenicity of histidine, an essential amino acid for most animal species, were examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given L-histidine monohydrochloride (HMHC) in their diet at concentrations of 0 (control), 1.25 and 2.5% for 104 wk; these dose levels were selected on the basis of the results of a subchronic toxicity study, in which body weights were depressed and formation of sperm granulomas in the epididymis was histologically evident in males fed 5.0% HMHC. All surviving rats were killed at wk 107. Increases in red blood cell count, haemoglobin value and haematocrit level were observed in male rats given 2.5% HMHC. A variety of tumours developed in all groups, including the control group, but all the neoplastic lesions were histologically similar to those known to occur spontaneously in this strain of rats, and no statistically significant increase in the incidence of any tumor was found in the treated groups of either sex. Thus, it was concluded that, under the present experimental conditions, HMHC is not carcinogenic in F344 rats.
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- 1996
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66. Inhibitory effects of the dietary antioxidants butylated hydroxyanisole and butylated hydroxytoluene on bronchioloalveolar cell proliferation during the bleomycin-induced pulmonary fibrosing process in hamsters
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Enami T, Chikako Uneyama, Takayoshi Imazawa, A. Nishikawa, Fumio Furukawa, Shoji Fukushima, S. Ikezaki, and Mika Takahashi
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Male ,medicine.medical_specialty ,Pathology ,Antioxidant ,Pulmonary Fibrosis ,medicine.medical_treatment ,Butylated Hydroxyanisole ,Bronchi ,Biology ,Toxicology ,Bleomycin ,Antioxidants ,chemistry.chemical_compound ,Fibrosis ,Cricetinae ,Internal medicine ,Macrophages, Alveolar ,Pulmonary fibrosis ,medicine ,Animals ,Butylated hydroxytoluene ,Lung ,Mesocricetus ,Organ Size ,General Medicine ,Butylated Hydroxytoluene ,medicine.disease ,Diet ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Toxicity ,Pulmonary alveolus ,Butylated hydroxyanisole ,Cell Division ,Food Science - Abstract
The effects of dietary antioxidants on bleomycin (BLM)-induced pulmonary fibrosis were investigated in Syrian golden hamsters. In addition, the influence on cell proliferative activity in bronchioloalveolar hyperplastic lesions during the lung fibrosing process was evaluated in terms of argyrophil nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA). Male 6-wk-old hamsters were divided into six groups. Groups 1-3 were intratracheally instilled with BLM at a dose of 2.5 U/kg body weight on days 0 and 14, and then given a diet supplemented with 1% butylated hydroxyanisole (BHA), or 1% butylated hydroxytoluene (BHT), or basal diet alone for the following 41 days. Groups 4-6 were given 1% BHA, 1% BHT or basal diet without BLM treatment for the same time period as that in those of groups 1-3. The mortality rate of animals in group 1 (BLM/BHA) (one in 20; 5%) was lower than in those of groups 2 (BLM/BHT) (three in 20; 15%) and 3 (BLM alone) (four in 20; 20%). BHA and BHT treatments significantly inhibited lung weight gains by BLM (P0.05). Histopathologically, both BHA and BHT reduced BLM-induced pulmonary histopathological changes such as fibrosis, macrophage aggregation and epithelial proliferation, with a tendency for correlation with accumulation of type III collagen. In addition, antioxidant treatment significantly lowered the mean numbers of AgNORs (P0.01) and PCNA-labelling indices (P0.05) in the hyperplastic bronchioloalveolar lesions. The results thus indicate that these antioxidants exert inhibitory effects on proliferation of hyperplastic lesions associated with lung fibrosis.
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- 1996
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67. Effects of Kabosu (Citrus sphaerocarpa Hort.) on Serum and Liver Cholesterol Levels in Rats
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Ayako Yamamoto, Mika Takahashi, and Satoshi Mochizuki
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Liver cholesterol ,Biochemistry ,Traditional medicine ,biology ,Kabosu ,Citrus sphaerocarpa ,biology.organism_classification - Abstract
カボスを種々の方法で分画し, それぞれの画分を飼料に添加してラットに投与し, 血清および肝臓コレステロールレベルに対する影響を検討した。1) 高コレステロール食にカボス画分を添加した飼料をラットに与えたところ, 果実の搾汁粕にはコレステロール上昇抑制作用が認められなかった。一方, 果汁にエタノールを添加して得られた沈澱物とそのヘキサン抽出残渣には強いコレステロール上昇抑制作用が認められた。2) PCB添加食にカボス画分を添加して同様に検討したところ, 果実搾汁粕, 果汁エタノール沈澱物, およびそのヘキサン抽出残渣には強いコレステロール上昇抑制作用が認められた。3) 高コレステロール食, PCB添加食のいずれを与えた場合にも, コレステロール上昇抑制作用をもつ画分を与えたときには, 糞中への中性ステロールならびに胆汁酸の排泄量が増加しており, これがコレステロール上昇抑制作用の一つの作用機構であると考えられた。
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- 1996
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68. Effects of a Ethanol Precipitated Fraction of Kabosu (Citrus sphaerocarpa Hort.) Juice on Cholesterol Metabolism in Rats
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Ayako Yamamoto, Mika Takahashi, and Satoshi Mochizuki
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Excretion ,chemistry.chemical_compound ,Ethanol ,Biochemistry ,biology ,chemistry ,Kabosu ,Fraction (chemistry) ,Secretion ,Citrus sphaerocarpa ,Cholesterol metabolism ,biology.organism_classification - Abstract
カボス果汁にエタノールを加えて得られた沈澱物 (カボス果汁粕) を飼料に添加してラットに与え, コレステロール代謝に対する影響を検討した。1) カボス果汁粕の投与量を2.5, 5, 10%として高コレステロール食に添加して与えたところ, 血中および肝臓コレステロールレベルはカボス果汁粕の投与量の増加に伴って低下した。また, 糞中への中性ステロールならびに胆汁酸の排泄量は, ほぼ投与量に依存して増加していた。2) 無コレステロール食および高コレステロール食にカボス果汁粕を10%添加して与えた場合には, 早い時期からカボス果汁粕のコレステロール上昇抑制効果が認められ, その効果は持続した。3) カボス果汁粕の血清コレステロール濃度上昇抑制効果の機構の一つとして, 肝臓から血液へのコレステロールの分泌速度の低下が明らかとなった。4) カボス果汁粕を乾熱あるいはオートクレーブによる加熱を行ってから与えてもコレステロール上昇抑制効果が弱まることはなかった。
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- 1996
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69. Effects of 'Kajime' Ecklonia cava Kjellman on Glucose Tolerance in Rats
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Ayako Yamamoto, Satoshi Mochizuki, and Mika Takahashi
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medicine.medical_specialty ,Ecklonia cava ,biology ,Gastric emptying ,Chemistry ,Insulin ,medicine.medical_treatment ,Aquatic Science ,Body weight ,biology.organism_classification ,Endocrinology ,Internal medicine ,Time course ,medicine ,Stomach tube - Abstract
Male Wistar rats, starved for 24 hours, were given a glucose solution with a stomach tube to provide 250mg of glucose per 100g of body weight. Blood samples were collected after intubation and blood glucose was measured. The time course of blood glucose concentration after an administration of glucose solution containing “kajime” powder changed more gently than that of glucose solution alone. The degree of the effect depended on the amount of “kajime”. Secretion of insulin was also depressed by the administration of “kajime”. We concluded that “kajime” had blood glucose-and serum insulin-flattening activity. The delay of gastric emptying was assumed to be one of main factors in the activity.
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- 1995
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70. Effects of caffeine on glandular stomach carcinogenesis induced in rats by N-methyl-N′-nitro-N-nitrosoguanidine and sodium chloride
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S. Ikezaki, Tohru Hasegawa, Mika Takahashi, A. Nishikawa, Takayoshi Imazawa, and Fumio Furukawa
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Male ,Methylnitronitrosoguanidine ,medicine.medical_specialty ,Sodium ,chemistry.chemical_element ,Adenocarcinoma ,Sodium Chloride ,Toxicology ,chemistry.chemical_compound ,Basal (phylogenetics) ,Tap water ,Stomach Neoplasms ,Caffeine ,Internal medicine ,medicine ,Animals ,Drug Interactions ,Rats, Wistar ,Anticarcinogen ,Hyperplasia ,Stomach ,Body Weight ,Biological activity ,General Medicine ,Pylorus ,Rats ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Gastric Mucosa ,Biological Assay ,Lipid Peroxidation ,Precancerous Conditions ,Cell Division ,Food Science - Abstract
The modifying effects of caffeine ingestion on glandular stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and sodium chloride (NaCl) were investigated in male Wistar rats. Animals were given a MNNG solution (100 ppm) as their drinking water and simultaneously fed a diet supplemented with 5% NaCl for 8 wk. They then received 0.25% caffeine solution (groups 1 and 3) or tap water (groups 2 and 4) as the drinking water, and were fed the NaCl diet (groups 1 and 2) or basal diet (groups 3 and 4) for the following 32 wk. Both caffeine and NaCl treatments exerted growth retardation effects, the suppression being stronger with caffeine than NaCl, and animals in group 1 (NaCl plus caffeine) showing the lowest body weight. The incidence of adenocarcinomas in the pylorus was significantly decreased in group 1 compared with the group 2 (NaCl) value (P0.05). The incidence of atypical hyperplasias in the fundus was also lower in group 1 than in group 2, although in both cases significantly higher (P0.05 and P0.01) than in group 4 (no treatment). These results were in good agreement with short-term assay findings whereby lipid peroxidation in the glandular stomach mucosa induced by 4% NaCl ingestion was inhibited by caffeine treatment. In group 3 (caffeine), caffeine intake by itself did not modulate glandular stomach tumour development. The results thus suggest that caffeine inhibits the gastric tumour promotion activity of NaCl in rats.
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- 1995
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71. [Toxicity effects of phthalate substitute plasticizers used in toys]
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Mutsuko, Hirata-Koizumi, Mika, Takahashi, Mariko, Matsumoto, Tomoko, Kawamura, Atsushi, Ono, and Akihiko, Hirose
- Subjects
No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,Reproduction ,Phthalic Acids ,Administration, Oral ,Kidney ,Play and Playthings ,Rats ,Structure-Activity Relationship ,Dogs ,Liver ,Plasticizers ,Animals ,Humans ,Polyvinyl Chloride - Abstract
Phthalate esters are widely used as plasticizers in polyvinyl chloride products. Because of human health concerns, regulatory authorities in Japan, US, Europe and other countries control the use of di(2-ethylhexyl) phthalate, diisononyl phthalate, di-n-butyl phthalate, butylbenzyl phthalate, diisodecyl phthalate and di-n-octyl phthalate for the toys that can be put directly in infants' mouths. While these regulatory actions will likely reduce the usage of phthalate esters, there is concern that other plasticizers that have not been sufficiently evaluated for safety will be used more frequently. We therefore collected and evaluated the toxicological information on di(2-ethylhexyl) terephthalate (DEHT), 1,2-cyclohexanedicarboxylic acid, diisononyl ester (DINCH), diisononyl adipate (DINA), 2,2,4-trimetyl-1,3-pentanediol diisobutyrate (TXIB), tri-n-butyl citrate (TBC) and acetyl tri-n-butyl citrate (ATBC) which were detected at a relatively high frequency in toys. The collected data have shown that chronic exposure to DEHT affects the eye and nasal turbinate, and DINCH exerts effects on the thyroid and kidney in rats. DINA and TXIB have been reported to have hepatic and renal effects in dogs or rats, and ATBC slightly affected the liver in rats. The NOAELs for repeated dose toxicity are relatively low for DINCH (40 mg/kg bw/day) and TXIB (30 mg/kg bw/day) compared with DEHT, DINA and ATBC. DEHT, TXIB and ATBC have been reported to have reproductive/developmental effects at relatively high doses in rats. For DINA and TBC, available data are insufficient for assessing the hazards, and therefore, adequate toxicity studies should be conducted. In the present review, the toxicity information on 6 alternatives to phthalate plasticizers is summarized, focusing on the effects after oral exposure, which is the route of most concern.
- Published
- 2012
72. Reproductive and developmental toxicity screening test of 3-cyanopyridine in rats
- Author
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Mutsuko Hirata-Koizumi, Mariko Matsumoto, Hina Kato, Tomoko Kawamura, Mika Takahashi, Atsushi Ono, Kaoru Yabe, and Akihiko Hirose
- Subjects
Male ,medicine.medical_specialty ,Screening test ,Pyridines ,Developmental toxicity ,Physiology ,Estrous Cycle ,Biology ,Toxicology ,Corpus Luteum ,Pregnancy ,Lactation ,Internal medicine ,medicine ,Animals ,Liver damage ,Mating ,Spermatogenesis ,reproductive and urinary physiology ,Estrous cycle ,No-Observed-Adverse-Effect Level ,Reproduction ,Organ Size ,Rats ,medicine.anatomical_structure ,Endocrinology ,Liver ,Toxicity ,Gestation ,Female - Abstract
Crl:CD(SD)rats were given 3-cyanopyridine by gavage at 0, 5, 30 or 180 mg/kg/day. Males were dosed for 42 days beginning 14 days before mating, and females for 40–53 days beginning 14 days before mating to day 3 of lactation, including throughout the mating and gestation periods. General toxicity, mainly liver damage, was observed in males at ≥30 mg/kg/day and in females at ≥5 mg/kg/day. Sertoli cell vacuolation was observed at 180 mg/kg/day, and spermatocyte damages were observed at ≥30 mg/kg/day. Effects on estrous cycles, corpora lutea and implantations, and unsuccessfully mated females, despite additional mating, were observed at 180 mg/kg/day. Delayed initiation of delivery, dystocia, and deaths or moribundities of pregnant females were observed at 180 mg/kg/day, and only two pregnant rats delivered live pups at that dose. The NOAEL for reproductive/developmental toxicity was concluded to be 30 mg/kg/day.
- Published
- 2012
73. Uretero-Internal Pudendal Artery Fistula with Longterm Indwelling of Ureteral Stent: A Case Report
- Author
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Takeo Nomura, Tadasuke Ando, Yasuhiro Takayama, Hideo Yuki, Mika Takahashi, Yasuhiro Sumino, Masahisa Takuma, Hiromitsu Mimata, and Fuminori Sato
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Cervical cancer ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Fistula ,lcsh:R ,lcsh:Medicine ,Stent ,Case Report ,General Medicine ,medicine.disease ,urologic and male genital diseases ,female genital diseases and pregnancy complications ,Surgery ,Urethra ,medicine.anatomical_structure ,medicine.artery ,Angiography ,Medicine ,Ureteral Stricture ,Internal pudendal artery ,Radical Hysterectomy ,business - Abstract
A 74-year-old woman presenting with bilateral ureteral stricture was referred to our hospital. She had undergone radical hysterectomy and adjuvant irradiation therapy for cervical cancer in 2000. Double-J stents were inserted in both the ureters and replaced at regular intervals. Eighteen months after ureteral stenting, she complained of gross hematuria and was managed with hemostatic agents. During a routine replacement of the right double-J stent, massive bleeding was observed from the urethra which continued intermittently. The source of bleeding was not identified on computed tomography and angiography. We kept her at rest, which reduced the bleeding. However, she required intermittent transfusions. Angiography was performed at the time of bleeding on March 5, 2011. A uretero-internal pudendal artery fistula was found, and coil embolization was performed. Thereafter, hematuria did not recur up to the last followup in July 2011.
- Published
- 2012
74. Sub-acute oral toxicity study with fullerene C60 in rats
- Author
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Atsushi Ono, Mika Takahashi, Hina Kato, Akihiko Hirose, Reiji Kubota, Mutsuko Hirata-Koizumi, Tetsuji Nishimura, Akihiro Hagiwara, and Yuko Doi
- Subjects
Male ,medicine.medical_specialty ,Physiology ,Administration, Oral ,Spleen ,Toxicology ,Kidney ,Oral administration ,medicine ,Animals ,Large intestine ,Feces ,business.industry ,Stomach ,Kidney metabolism ,Organ Size ,Surgery ,Rats ,medicine.anatomical_structure ,Toxicity Tests, Subacute ,Liver ,Female ,Fullerenes ,business ,Corn oil - Abstract
To obtain initial information on the possible repeated-dose oral toxicity of fullerene C60, Crl:CD(SD) rats were administered fullerene C60 by gavage once daily at 0 (vehicle: corn oil), 1, 10, 100, or 1,000 mg/kg/day for 29 days, followed by a 14-day recovery period. No deaths occurred in any groups, and there were no changes from controls in detailed clinical observations, body weights, and food consumption in any treatment groups. Moreover, no treatment-related histopathological changes were found in any organs examined at the end of the administration period and at the end of the recovery period. Blackish feces and black contents of the stomach and large intestine were observed in males and females at 1,000 mg/kg/day in the treatment group. There were no changes from controls in the liver and spleen weights at the end of the administration period, but those weights in males in the 1,000 mg/kg/day group increased at the end of the recovery period. Using liquid chromatography-tandem mass spectrometry, fullerene C60 were not detected in the liver, spleen or kidney at the end of the administration period and also at the end of the recovery period. In conclusion, the present study revealed no toxicological effects of fullerene C60; however, the slight increases in liver and spleen weights after the 14-day recovery period may be because of the influence of fullerene C60 oral administration. In the future, it will be necessary to conduct a long-term examination because the effects of fullerene C60 cannot be ruled out.
- Published
- 2012
75. DFP-sensitive multicatalytic protease complexes (proteasomes) involved in the control of oocyte maturation in the toad,Bufo japonicus
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Mika Takahashi, Toshinobu Tokumoto, and Katsutoshi Ishikawa
- Subjects
Proteasome Endopeptidase Complex ,medicine.medical_specialty ,Proteases ,Isoflurophate ,Serine Proteinase Inhibitors ,medicine.medical_treatment ,Toad ,Cytosol ,Multienzyme Complexes ,biology.animal ,Internal medicine ,Genetics ,medicine ,Animals ,Progesterone ,Serine protease ,Protease ,Germinal vesicle ,biology ,urogenital system ,Cell Biology ,Oocyte ,Bufonidae ,Cell biology ,Cysteine Endopeptidases ,Kinetics ,Meiosis ,Endocrinology ,medicine.anatomical_structure ,Proteasome ,Oocytes ,biology.protein ,Female ,Developmental Biology - Abstract
The inhibition of progesterone-induced oocyte maturation by diisopropylfluorophosphate (DFP), a typical serine protease inhibitor, was investigated in oocytes of the Japanese toad Bufo japonicus for the first time. Oocytes to which DFP was externally applied did not undergo germinal vesicle breakdown (GVBD), which is an early signal of oocyte maturation, in response to progesterone. The more inhibitory period was found to be 0–0.5 GVBD50 on a relative time scale [when the time at which 50% of the oocytes had completed GVBD (GVBD50) was set at 1.0], namely, before the beginning of GVBD. DFP-sensitive proteases, which seem to be multifunctional nonlysosomal protease complexes (proteasomes), may already be present in the cytosol of premature oocytes. Peptide hydrolyzing activity, as reflected by proteasome activity, was found to be regulated before and after GVBD. In addition, immunoblotting regarding the native electrophoretic protein profile of the proteasomes throughout the maturational process demonstrated that they undergo alterations in mobility dependent upon the maturational process. These findings raise the possibility that the activities of some endogenous DFP-sensitive proteasomes play distinct, essential roles in oocyte maturation triggered by progesterone in Bufo. © 1994 Wiley-Liss, Inc.
- Published
- 1994
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76. Mirror biofeedback rehabilitation after administration of single-dose botulinum toxin for treatment of facial synkinesis
- Author
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Noriaki Takeda, Bukasa Kalubi, Mika Takahashi, Katsuhiko Nakamura, Seizo Ohyama, Takahiro Azuma, Naoki Toda, and Hidetaka Iwasaki
- Subjects
Adult ,Male ,medicine.medical_specialty ,Synkinesis ,medicine.medical_treatment ,Treatment outcome ,Facial Paralysis ,Facial Muscles ,Biofeedback ,Injections, Intramuscular ,Physical medicine and rehabilitation ,Medicine ,Humans ,In patient ,Prospective Studies ,Botulinum Toxins, Type A ,Aged ,Botulinum a toxin ,Rehabilitation ,Dose-Response Relationship, Drug ,business.industry ,Follow up studies ,Biofeedback, Psychology ,Middle Aged ,medicine.disease ,Botulinum toxin ,stomatognathic diseases ,Treatment Outcome ,Otorhinolaryngology ,Neuromuscular Agents ,Face ,Chronic Disease ,Surgery ,Female ,business ,medicine.drug ,Follow-Up Studies ,Muscle Contraction - Abstract
The efficacy of facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin on facial synkinesis was examined in patients with chronic facial palsy.Prospective clinical study.University hospital.The present study includes 8 patients with Bell palsy and 5 with herpes zoster oticus showing facial synkinesis. A single dose of botulinum A toxin was used as the initial process of facial rehabilitation. Patients then continued a daily facial biofeedback rehabilitation with a mirror at home. They were instructed to keep their eyes symmetrically open using a mirror during mouth movements. The degree of oral-ocular synkinesis was evaluated by the degree of asymmetry of eye opening width during mouth movements (% eye opening).After administration of a single dose of botulinum A toxin, temporary relief of facial synkinesis was observed in all patients. Patients were then instructed to continue the facial biofeedback rehabilitation with a mirror for 10 months. The mean values of the percent of eye opening during 3 designated mouth movements that included lip pursing /u:/, teeth baring /i:/, and cheek puffing /pu:/ increased significantly after 10 months when the effects of botulinum A toxin had completely disappeared.These findings demonstrate that facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin is a long-lasting treatment of established facial synkinesis in patients with chronic facial palsy.
- Published
- 2011
77. Reproductive and developmental toxicity screening study of 2,4-dinitrophenol in rats
- Author
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Masao Sunaga, Makoto Ema, Akihiko Hirose, Mika Takahashi, Eiichi Kamata, and Mutsuko Hirata-Koizumi
- Subjects
Male ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Developmental toxicity ,Physiology ,Management, Monitoring, Policy and Law ,Biology ,Toxicology ,Body weight ,2,4-Dinitrophenol ,chemistry.chemical_compound ,Pregnancy ,Internal medicine ,Lactation ,medicine ,Animals ,Screening study ,Reproduction ,Body Weight ,Abnormalities, Drug-Induced ,General Medicine ,Organ Size ,medicine.disease ,Rats ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Animals, Newborn ,Liver ,Toxicity ,Female ,Live birth - Abstract
Rats were treated by gavage once daily with 2,4-dinitrophenol (DNP) at 0 (control), 3, 10, or 30 mg/kg bw. Males were dosed for 46 days, beginning 14 days before mating, and females were dosed for 40-47 days, from 14 days before mating to day 3 of lactation. No deaths were observed in males and females of any group. A significant decrease in body weight gain and significant increase in liver weight were found in males and females at 30 mg/kg bw/day. The number of live pups on postnatal days (PNDs) 0 and 4, live birth index, and body weight of live male and female pups on PNDs 0 and 1 were significantly lowered at 30 mg/kg bw/day. External and internal examinations of pups revealed no increased incidence of malformations in DNP-treated groups. On the basis of these findings, we concluded that DNP has general and reproductive/developmental toxicity, but not teratogenicity, under the present conditions. The NOAEL of DNP is considered to be 10 mg/kg bw/day in rats.
- Published
- 2008
78. [Progress on OECD Chemicals Programme (13)--SIAM 22 in Paris, 2006]
- Author
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Mika, Takahashi, Mariko, Matsumoto, Kazumi, Kawahara, Seiichirou, Kanno, Yoshio, Sugaya, Akihiko, Hirose, Eiichi, Kamata, and Makoto, Ema
- Subjects
Male ,Paris ,International Cooperation ,Animals ,Humans ,International Agencies ,Female ,Environmental Exposure ,Rabbits ,Hazardous Substances ,Rats - Abstract
The 22nd Screening Information Data Set (SIDS) Initial Assessment Meeting (SIAM 22) was held at the Organisation for Economic Co-operation and Development (OECD) headquarters in Paris, France. The initial assessment documents of five substances (CAS numbers: 75-59-2, 80-51-3, 101-83-7, 103-24-2, 27813-02-1) sponsored by Japan were all agreed at the meeting. In this report, the documents of these substances are introduced.
- Published
- 2008
79. [Progress on OECD chemicals programme (11)--SIAM 19 in Berlin, 2004]
- Author
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Mika, Takahashi, Mariko, Matsumoto, Kazumi, Kawahara, Seiichirou, Kanno, Yoshio, Sugaya, Akihiko, Hirose, Eiichi, Kamata, and Makoto, Ema
- Subjects
Berlin ,Male ,Japan ,International Cooperation ,Guinea Pigs ,Animals ,Humans ,International Agencies ,Female ,Environmental Exposure ,Rabbits ,Hazardous Substances ,Rats - Abstract
The 19th Screening Information Data Set (SIDS) Initial Assessment Meeting (SIAM 19) was held in Berlin, Germany, hosted by the Germen Federal Agency for the Environment. The initial assessment documents of four substances (CAS numbers: 92-70-6, 126-33-0,131-17-9, 7580-85-0) and one category (High Molecular Weight Phthalate Esters) at SIAM 19 were submitted by the Japanese Government with or without the International Council of Chemical Associations (ICCA) and all of them were agreed at the meeting. In this report, the documents of these substances are introduced.
- Published
- 2007
80. Challenge and current status of night outpatient chemotherapy in our institution
- Author
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Mika Takahashi, Yoko Tokumitsu, Kazue Hanyu, Ichiro Naruse, Yoshitaka Ando, Tomomi Shimizu, Hisanori Shoji, Kyoichi Kaira, Masahiko Motegi, and Takayuki Asao
- Subjects
medicine.medical_specialty ,Oncology ,Outpatient chemotherapy ,business.industry ,General surgery ,medicine ,Hematology ,Intensive care medicine ,business - Published
- 2015
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81. Derivation of subacute reference doses for drinking water quality management
- Author
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Mutsuko Hirata-Koizumi, Akihiko Hirose, Mariko Matsumoto, Atsushi Ono, Makoto Ema, Tomoko Nishimaki-Mogami, Mika Takahashi, Tetsuji Nishimura, and Tomoko Kawamura
- Subjects
Environmental chemistry ,Environmental science ,General Medicine ,Toxicology ,Water resource management ,Water quality management - Published
- 2015
- Full Text
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82. Is a 14-day dose setting study able to predict its 28-day repeated dose toxicity?
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Akihiko Hirose, Mutsuko Hirata-Koizumi, Mariko Matsumoto, Tomoko Kawamura, Atsushi Ono, and Mika Takahashi
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business.industry ,Anesthesia ,Toxicity ,Medicine ,General Medicine ,Toxicology ,business - Published
- 2015
- Full Text
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83. Susceptibility of newborn rats to 3-ethylphenol and 4-ethylphenol compared with that of young rats
- Author
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Yoshihiko Ito, Ryuichi Hasegawa, Mutsuko Hirata-Koizumi, Masao Sunaga, Makoto Ema, Nobuo Nishimura, Mika Takahashi, Sakiko Fujii, and Eiichi Kamata
- Subjects
Male ,Embryology ,medicine.medical_specialty ,No-observed-adverse-effect level ,Administration, Oral ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Age Distribution ,Phenols ,Oral administration ,Internal medicine ,Respiration ,Medicine ,Animals ,Sex Distribution ,3-Ethylphenol ,No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,business.industry ,Body Weight ,General Medicine ,Rats ,Dose–response relationship ,Endocrinology ,chemistry ,Animals, Newborn ,Liver ,Pediatrics, Perinatology and Child Health ,Toxicity ,Female ,Righting reflex ,business ,Hypoactivity ,Developmental Biology - Abstract
Newborn rat studies were conducted with oral administration of 3-ethylphenol (3EP) and 4-ethylphenol (4EP) on postnatal days (PND) 4-21 to allow comparison of no observed adverse effect level (NOAEL) and unequivocally toxic level (UETL) with those from 28-day studies of young rats starting at 5-6 weeks of age. In the newborn rat studies, slightly lowered body weight was observed after 3EP treatment, and deaths, hypoactivity, Straub tail, deep respiration and delayed righting reflex were clearly observed after 4EP treatment. In the young rat studies, salivation, staggering gait, changes in the liver including high values of liver weight and alanine aminotransferase or total cholesterol and the lesions in the forestomach were clearly observed after 3EP and 4EP treatments. NOAELs of 3EP and 4EP in the newborn rat studies appeared to be almost 3 times lower than those in the young rat studies. As a clear toxicity of 3EP was not observed in newborn rats, UETLs were not established for 3EP. Regarding 4EP, UETL of young rats was 4-5 times higher than that of newborn rats. In conclusion, newborn rats were 3-5 times more susceptible to 3EP and 4EP than young rats.
- Published
- 2006
84. [Progress on OECD chemicals programme (7)--SIAM 15 in Boston, 2002]
- Author
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Mika, Takahashi, Mutsuko, Hirata-Koizumi, Mariko, Matsumoto, Akihiko, Hirose, Eiichi, Kamata, Ryuichi, Hasegawa, and Makoto, Ema
- Subjects
Male ,Mice ,Japan ,International Cooperation ,Animals ,Humans ,International Agencies ,Rabbits ,Hazardous Substances ,Boston ,Rats - Abstract
The 15th Screening Information Data Set (SIDS) Initial Assessment Meeting (SIAM 15) was held in Boston, USA. The initial assessment documents of twelve substances at SIAM 15 (CAS numbers: 79-39-0, 88-60-8, 92-70-6, 102-76-1, 110-83-8, 135-19-3, 7647-01-0, 8007-18-9, 10043-52-4, 11070-44-3, 25321-09-9, 68186-90-3) were submitted by the Japanese Government with or without the International Council of Chemical Associations (ICCA) and all of them on the human health effect parts were agreed at the meeting. In this report, the human health effect parts in their 12 substance documents are introduced.
- Published
- 2006
85. A Case of Langerhans Cell Histiocytosis of the Temporal Bone
- Author
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Noriaki Takeda, Mika Takahashi, Koji Abe, and Hiroki Onishi
- Subjects
Pathology ,medicine.medical_specialty ,Otorhinolaryngology ,Langerhans cell histiocytosis ,business.industry ,Temporal bone ,Medicine ,business ,medicine.disease - Published
- 2014
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86. Comparative susceptibility of newborn and young rats to six industrial chemicals
- Author
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Makoto Ema, Ryuichi Hasegawa, Mika Takahashi, Eiichi Kamata, and Mutsuko Hirata-Koizumi
- Subjects
Trityl chloride ,Male ,Embryology ,No-observed-adverse-effect level ,Alpha (ethology) ,Physiology ,Kidney ,Toxicology ,Nitrophenols ,Rats, Sprague-Dawley ,Phenols ,Benzene Derivatives ,Animals ,No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,Phenols toxicity ,Chemistry ,Body Weight ,Stomach ,Trityl Compounds ,General Medicine ,Organ Size ,Rats ,Sprague dawley ,Dose–response relationship ,Animals, Newborn ,Liver ,Pediatrics, Perinatology and Child Health ,Toxicity ,Female ,Developmental Biology ,Chlorophenols - Abstract
To elucidate the comparative susceptibility of newborn rats to chemicals, newborn and young animals were administered six industrial chemicals by gavage from postnatal days (PND) 4 to 21, and for 28 days starting at 5-6 weeks of age respectively, under the same experimental conditions as far as possible. As two new toxicity endpoints specific to this comparative analysis, presumed no-observed-adverse-effect-levels (pNOAELs) were estimated based on results of both main and dose-finding studies, and presumed unequivocally toxic levels (pUETLs) were also decided. pNOAELs for newborn and young rats were 40 and 200 for 2-chlorophenol, 100 and 100 for 4-chlorophenol, 30 and 100 for p-(alpha,alpha-dimethylbenzyl) phenol, 100 and 40 for (hydroxyphenyl)methyl phenol, 60 and 12 for trityl chloride, and 100 and 300 mg/kg/day for 1,3,5-trihydroxybenezene, respectively. To determine pUETLs, dose ranges were adopted in several cases because of the limited results of experimental doses. Values for newborn and young rats were thus estimated as 200-250 and 1000 for 2-chlorophenol, 300 and 500 for 4-chlorophenol, 300 and 700-800 for p-(alpha,alpha-dimethylbenzyl) phenol, 140-160 and 1000 for (hydroxyphenyl)methyl phenol, 400-500 and 300 for trityl chloride, and 500 and 1000 mg/kg/day for 1,3,5-trihydroxybenzene, respectively. In most cases, newborn rats were 2-5 times more susceptible than young rats in terms of both the pNOAEL and the pUETL. An exception was that young rats were clearly more susceptible than their newborn counterparts for trityl chloride.
- Published
- 2005
87. Elevated susceptibility of newborn as compared with young rats to 2-tert-butylphenol and 2,4-di-tert-butylphenol toxicity
- Author
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Makoto Ema, Yoshihiko Ito, Hiromi Furukawa, Yumi Wako, Kotaro Yamashita, Mika Takahashi, Ryuichi Hasegawa, Naemi Fukuda, Eiichi Kamata, Mutsuko Hirata-Koizumi, and Masao Hamamura
- Subjects
Embryology ,medicine.medical_specialty ,Ontogeny ,Kidney ,Locomotor activity ,Rats, Sprague-Dawley ,Phenols ,Oral administration ,Internal medicine ,medicine ,2-tert-butylphenol ,Animals ,Organ weight ,No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,business.industry ,Body Weight ,Age Factors ,General Medicine ,Organ Size ,Rats ,Endocrinology ,Animals, Newborn ,Liver ,Anesthesia ,Pediatrics, Perinatology and Child Health ,Toxicity ,Reflex ,business ,Blood Chemical Analysis ,Developmental Biology - Abstract
In order to determine the susceptibility of newborn rats to 2-tert-butylphenol (2TBP) and 2,4-di-tert-butylphenol (DTBP) toxicity, studies were conducted with oral administration from postnatal days (PND) 4 to 21 and the findings were compared with results for young rats exposed from 5 or 6 weeks of age for 28 days. In the newborn rats, specific effects on physical and sexual development and reflex ontogeny were not observed. While there were no clear differences in toxicological profiles between newborn and young rats, the no-observed-adverse-effect levels (NOAELs) differed markedly. For 2TBP, clinical signs such as ataxic gait, decrease in locomotor activity and effects on liver, such as increase in organ weight, were observed and the NOAELs were concluded to be 20 and 100 mg/kg/day in newborn and young rats, respectively. Based on hepatic and renal toxicity (histopathological changes and increase in organ weight with blood biochemical changes), the respective NOAELs for DTBP were concluded to be 5 and 20 mg/kg/day. Therefore, the susceptibility of newborn rats to 2TBP and DTBP was found to be 4-5 times higher than that of young rats.
- Published
- 2005
88. In silico assessment of chemical mutagenesis in comparison with results of Salmonella microsome assay on 909 chemicals
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Mika Takahashi, Makoto Hayashi, Makoto Ema, Akihiko Hirose, Takeshi Morita, and Eiichi Kamata
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Salmonella ,Quantitative structure–activity relationship ,biology ,Databases, Factual ,Mutagenicity Tests ,Health, Toxicology and Mutagenesis ,Living environment ,In silico ,Mutagenesis (molecular biology technique) ,medicine.disease_cause ,biology.organism_classification ,Enterobacteriaceae ,Structure-Activity Relationship ,Biochemistry ,Microsomes ,Immunology ,Genetics ,medicine ,Microsome ,Biological Assay ,Computer Simulation ,Genotoxicity ,Mutagens - Abstract
Genotoxicity is one of the important endpoints for risk assessment of environmental chemicals. Many short-term assays to evaluate genotoxicity have been developed and some of them are being used routinely. Although these assays can generally be completed within a short period, their throughput is not sufficient to assess the huge number of chemicals, which exist in our living environment without information on their safety. We have evaluated three commercially available in silico systems, i.e., DEREK, MultiCASE, and ADMEWorks, to assess chemical genotoxicity. We applied these systems to the 703 chemicals that had been evaluated by the Salmonella/microsome assay from CGX database published by Kirkland et al. [1]. We also applied these systems to the 206 existing chemicals in Japan that were recently evaluated using the Salmonella/microsome assay under GLP compliance (ECJ database). Sensitivity (the proportion of the positive in Salmonella/microsome assay correctly identified by the in silico system), specificity (the proportion of the negative in Salmonella/microsome assay correctly identified) and concordance (the proportion of correct identifications of the positive and the negative in Salmonella/microsome assay) were increased when we combined the three in silico systems to make a final decision in mutagenicity, and accordingly we concluded that in silico evaluation could be optimized by combining the evaluations from different systems. We also investigated whether there was any correlation between the Salmonella/microsome assay result and the molecular weight of the chemicals: high molecular weight (>3000) chemicals tended to give negative results. We propose a decision tree to assess chemical genotoxicity using a combination of the three in silico systems after pre-selection according to their molecular weight.
- Published
- 2005
89. Electroneurography cannot predict when facial synkinesis develops in patients with facial palsy.
- Author
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Takahiro Azuma, Katsuhiko Nakamura, Mika Takahashi, Hitomi Miyoshi, Naoki Toda, Hidetaka Iwasaki, Teruhiko Fuchigami, Go Sato, Yoshiaki Kitamura, Koji Abe, and Noriaki Takeda
- Subjects
FACIAL paralysis ,REHABILITATION ,NEURAL conduction ,FACIAL dyskinesias ,FACIAL nerve diseases - Abstract
The objective of this study is to clarify when facial palsy patients with lower value of Electroneurography (ENoG) should begin the rehabilitation to prevent the development of facial synkinesis. For this purpose, we examined the relationship between the value of ENoG measured 10-14 days after facial palsy onset and the onset day of the development of oral-ocular synkinesis. Sixteen patients with facial palsy including 11 with Bell's palsy and 5 with Ramsay Hunt syndrome (7 men and 9 women ; 15-73 years old ; mean age, 41.6 years) were enrolled in this study. There was no correlation between ENoG value and the onset day of the development of oral-ocular synkinesis (p = .09, p = .73). Oral-ocular synkinesis began to develop in 4.0 ± 0.7 months (mean ± SD ; range : 3.1-5.0 months) after facial palsy onset regardless of ENoG value. In conclusion, ENoG value cannot predict when facial synkinesis develops in patients with facial palsy. We recommend that facial palsy patients with a high risk for the development of synkinesis begin the biofeedback rehabilitation with mirror to prevent the development of facial synkinesis 3 months after facial palsy onset. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
90. Comparative toxicity study of 2,4,6-trinitrophenol (picric acid) in newborn and young rats
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Hiroyuki Izumi, Makoto Ema, Mutsuko Hirata-Koizumi, Mika Takahashi, Masato Takechi, Hidehiro Ogata, Eiichi Kamata, Kotaro Yamashita, and Ryuichi Hasegawa
- Subjects
Hemolytic anemia ,Male ,Embryology ,Body weight ,Toxicology ,Lower body ,Animal science ,Picrates ,Pregnancy ,Testis ,Medicine ,Animals ,Behavior, Animal ,Dose-Response Relationship, Drug ,business.industry ,Body Weight ,General Medicine ,medicine.disease ,Rats ,Animals, Newborn ,Pediatrics, Perinatology and Child Health ,Toxicity ,Testicular toxicity ,Female ,business ,Developmental Biology - Abstract
The toxicity of oral 2,4,6-trinitrophenol (TNP) was determined in newborn rats, and compared with that in young rats. In newborn rats, males and females were given TNP at 0, 16.3, 81.4 or 407 mg/kg per day on postnatal days (PND) 4-17 for the dose-finding study, and at 0, 4.1, 16.3 or 65.1 mg/kg per day on PND 4-21 for the main study. Deaths, lower body weight (BW) and behavioral changes were found at 81.4 and 407 mg/kg per day in the dose-finding study, and lower BW was observed in males at 65.1 mg/kg per day during the dosing period of the main study. In young rats, 5-week-old males and females were given TNP at 0, 20, 100 or 500 mg/kg per day for 14 days as the dose-finding study and at 0, 4, 20 or 100 mg/kg per day for 28 days as the main study. Deaths were observed at 500 mg/kg per day in the dose-finding study. Deaths or changes in BW were not found at 100 mg/kg per day or less. At 100 mg/kg per day, hemolytic anemia and testicular toxicity were found. In conclusion, toxicity profiles induced by TNP were markedly different between newborn and young rats.
- Published
- 2004
91. Analysis of colors used on outdoor advertising in urban landscape: a case study in Osaka city
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Kazumi Fujibayashi, Tomomi Shimonaka, Kazuhiro Sawa, Mika Takahashi, and Masako Sato
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Harmony (color) ,Amusement ,Geography ,Point (typography) ,media_common.quotation_subject ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Advertising ,Atmosphere (architecture and spatial design) ,Urban landscape ,GeneralLiterature_MISCELLANEOUS ,Visual arts ,Business area ,media_common - Abstract
This is a case study for practical survey and assessment of urban landscapes containing outdoor advertisements in Osaka City, Japan. We practically surveyed and analyzed the colors used on the outdoor advertisements in the three urban areas: the business area long the main street, the amusement area along the shopping street, and the station plaza in front of the railroad terminal. Further by the laboratory experiments, we examined the interrelation between the atmosphere of the area and the impression arising from the outdoor advertisements using the pictures of street scenes on video monitor. In this experiment, eye movements of each subject observing the scene were analyzed by eye point recorder. (1) In general, vivid red, yellow, green and blue, and white and black were frequently used on the outdoor advertisements in every area. (2) The character of each area was respectively found out by analysis of the following factors: the type of advertisement, the size of each advertisement, and the arrangement of the advertisements. Vivid colors on the outdoor advertisements could be clearly perceived even from a distance. Then, our eyes would be attracted by vivid colors of them. (4) The atmosphere of the area would be affected by favorable or unfavorable impression from the outdoor advertisements. For instance, on the main street, the advertisements would impress us favorably if they are in harmony with each other and create an orderly and elegant streetscape. On the shopping street, various advertisements would impress us favorably if they create a lively and cheerful streetscape.
- Published
- 2002
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- View/download PDF
92. A quinol glucoside from Abeliophyllum distichum
- Author
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Mami Ito, Wu Hua-Xin, Kenichiro Inoue, Kiyokazu Takaishi, Mika Takahashi, and Hiroshi Kuwajima
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biology ,Stereochemistry ,Halleridone ,Calceolarioside ,Cyclohexanone ,Plant Science ,General Medicine ,Horticulture ,biology.organism_classification ,Biochemistry ,Abeliophyllum ,chemistry.chemical_compound ,Rutin ,Verbascoside ,chemistry ,Glucoside ,Molecular Biology ,Derivative (chemistry) - Abstract
Besides the known glucosides, calceolarioside D, verbascoside, cornoside, rutin and a cyclohexanone derivative, halleridone, a new quinol glucoside, ne
- Published
- 1993
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93. Sulfide oxidation by gene expressions of sulfide-quinone oxidoreductase and ubiquinone-8 biosynthase in Escherichia coli
- Author
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Hiroomi Shibata, Ikuko Yamaguchi, Mika Takahashi, and Shigeki Kobayashi
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chemistry.chemical_classification ,Rhodobacter ,Sulfide ,biology ,Hydrogen sulfide ,chemistry.chemical_element ,Bioengineering ,medicine.disease_cause ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Sulfur ,chemistry.chemical_compound ,chemistry ,Biochemistry ,medicine ,bacteria ,Oxidoreductase Gene ,Rhodospirillales ,Escherichia coli ,Rhodospirillaceae ,Biotechnology - Abstract
Sulfides (S 2− ,SH − ) such as hydrogen sulfide belong to a class of sulfur compounds with unpleasant odors. In order to confer sulfide-oxidizing ability on the intestine-inhabiting bacteria, the sulfide-quinone oxidoreductase gene (sqr) in Rhodobacter capsulatus DSM-155 and genes for quinone biosynthesis ( ubiC, ubiA and ispB ) in Escherichia coli XL1 Blue-MRF' were transduced into E. coli BL21(DE3). Plasmids pT7-7 and pSTV were used as vectors of sqr , and ubiCA and ispB , respectively. The recombinants sqr -BL21(DE3) and ubiCA,ispB-sqr -BL21(DE3) were successfully constructed. The maximal sulfide-removing activities of the whole cells and membrane fractions of sqr -BL21(DE3) attained at pH 8.0 and 7.8, were 267 nmol/mg cells (dry weight)/min and 1250 nmol/mg membrane fraction (protein)/min, respectively. The molecular ratio of sulfide (S 2− ) oxidized and oxygen (O 2 ) consumed was 2:1. SQR activity in the recombinant cells was positively restricted under anaerobic conditions and also by the addition of electron transfer inhibitors. Ubiquinone-8 (UQ-8) biosynthesis in the cells of ubiCA,ispB-sqr -BL21(DE3) increased as much as 2.2-fold compared with that of (pSTV)- sqr -BL21(DE3) during the 12–16 h incubation period. The maximal sulfide removal in the quinone-raised E. coli was attained slightly earlier, however, SQR activities thereafter were lower than those in (pSTV)- sqr -BL21(DE3).
- Published
- 1999
94. Higher susceptibility of newborn rats to 2-tert-butylphenol and 2,4-di-tert-butylphenol toxicity as compared with young rats
- Author
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Ryuichi Hasegawa, Kotaro Yamashita, Naemi Fukuda, Hiromi Furukawa, Makoto Ema, Eiichi Kamata, Mutsuko Hirata-Koizumi, Yoshihiko Ito, Yumi Wako, Masao Hamamura, and Mika Takahashi
- Subjects
Chemistry ,Toxicity ,2-tert-butylphenol ,General Medicine ,Toxicology ,Medicinal chemistry - Published
- 2007
- Full Text
- View/download PDF
95. Lack of carcinogenicity of medium-viscosity liquid paraffin given in the diet to F344 rats
- Author
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T. Shoda, Mika Takahashi, Chikako Uneyama, Kazuhiro Toyoda, and K. Takada
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Male ,medicine.medical_specialty ,Pathology ,Acceptable daily intake ,Liquid paraffin ,Physiology ,Administration, Oral ,Toxicology ,Eating ,Oral administration ,Internal medicine ,medicine ,Mesenteric lymph nodes ,Animals ,Mineral Oil ,Mesentery ,Carcinogen ,Hematology ,Emollients ,Chemistry ,Viscosity ,Incidence (epidemiology) ,Body Weight ,General Medicine ,Neoplasms, Experimental ,Organ Size ,Survival Analysis ,Rats, Inbred F344 ,Diet ,Rats ,medicine.anatomical_structure ,Toxicity ,Carcinogens ,Female ,Lymph Nodes ,Food Science - Abstract
The carcinogenicity of medium-viscosity liquid paraffin was examined in Fischer 344 rats. Groups of 50 males and 50 females were given the material at dietary doses of 0 (control), 2.5 or 5% for 104 wk. Slight increases in food consumption and body weight were observed in both sexes of the 5% group. However, no significant differences between the control and treated groups were noted with regard to clinical signs, mortality and haematology findings. A variety of tumours developed in all groups, including the control group, but all the neoplastic lesions were histologically similar to those known to occur spontaneously in F344 rats, and no statistically significant increase in the incidence of any tumour type was found for either sex in the treated groups. Granulomatous inflammation in the mesenteric lymph nodes, considered to be a reaction to paraffin absorption, was observed with similar incidence and severity in both sexes of the 2.5 and 5% groups. Thus, it is concluded that under the present experimental conditions, the high dose, about 2000-200,000 times higher than the current temporary acceptable daily intake, does not have any carcinogenic potential in F344 rats. Furthermore, granulomatous inflammation observed in mesenteric lymph nodes were not associated with any development of neoplastic lesions.
- Published
- 1998
96. Development of in silico genotoxicity predicting system on chromosomal aberration for existing industrial chemicals
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Akihiko Hirose, Makoto Ema, Makoto Hayashi, H. Akiyama, Mika Takahashi, and Eiichi Kamata
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Genetics ,business.industry ,In silico ,medicine ,General Medicine ,Chemical industry ,Biology ,Toxicology ,business ,medicine.disease_cause ,Genotoxicity - Published
- 2006
- Full Text
- View/download PDF
97. Promotional effects of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) on N-nitrosobis(2-oxopropyl)amine (BOP)-initiated carcinogenesis in hamsters
- Author
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Enami T, Fumio Furukawa, Takayoshi Imazawa, A. Nishikawa, H C Kim, Mika Takahashi, Mitsui M, K Kasahara, In-Seon Lee, and Tanakamaru Z
- Subjects
medicine.medical_specialty ,Nitrosamines ,Drinking ,Toxicology ,medicine.disease_cause ,chemistry.chemical_compound ,Islets of Langerhans ,Internal medicine ,Cricetinae ,medicine ,Endocrine system ,Animals ,Drug Interactions ,Lung ,Pancreas ,Pancreatic hormone ,Kidney ,geography ,geography.geographical_feature_category ,Mesocricetus ,General Medicine ,Islet ,Immunohistochemistry ,Pancreatic Neoplasms ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Liver ,Nitrosamine ,Carcinogens ,Female ,Carcinogenesis ,Precancerous Conditions ,Cell Division ,Food Science - Abstract
The effects of administration of low doses of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a tobacco-specific nitrosamine, were investigated in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Female Syrian golden hamsters were given a single sc injection of BOP at a dose of 10 mg/kg and then administered 2 or 5 ppm NNAL in their drinking water for 52 wk. Additional groups of animals received the BOP injection alone, or only the 2 or 5 ppm NNAL treatments as BOP-negative controls. At wk 53 of the experiment, all surviving animals were killed and the development of proliferative lesions was assessed histopathologically. The total incidence of combined carcinomatous and dysplastic lesions of the exocrine pancreas was significantly higher (P < 0.05) in the BOP/NNAL 5 ppm group than in the BOP alone group, although there was no statistically significant influence of NNAL on the development of either pancreatic adenocarcinomas or dysplastic lesions viewed singly. The treatments with NNAL alone did not induce any proliferative lesions of the exocrine pancreas. No significant intergroup differences were found in either incidence or multiplicity of islet cell proliferative lesions. Immunohistochemical examination of islet cell proliferative lesions (hyperplasias and adenomas) found in the BOP-treated animals showed no significant differences in pancreatic hormone production between NNAL-treated and -untreated groups. The NNAL treatment did not exert any influence on lung, liver or kidney tumorigenesis. Thus, the results suggest that NNAL enhances BOP-induced exocrine but not endocrine pancreatic tumorigenesis in hamsters when given in the post-initiation phase.
- Published
- 1997
98. Carcinogenicity study of beta-cyclodextrin in F344 rats
- Author
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Mika Takahashi, K. Takada, Chikako Uneyama, T. Shoda, and Kazuhiro Toyoda
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Male ,F344 rats ,Physiology ,Administration, Oral ,Biology ,Toxicology ,Basal (phylogenetics) ,Eating ,Neoplasms ,Ingestion ,Animals ,Carcinogen ,chemistry.chemical_classification ,Cyclodextrins ,Hematologic Tests ,Cyclodextrin ,Incidence (epidemiology) ,Body Weight ,beta-Cyclodextrins ,General Medicine ,Carbohydrate ,Rats, Inbred F344 ,Rats ,Survival Rate ,chemistry ,Chemistry, Clinical ,Toxicity ,Immunology ,Carcinogens ,Female ,Food Science - Abstract
The carcinogenicity of β-cyclodextrin, a cyclic, water-soluble carbohydrate comprising seven glucose units, was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the compound in their diet at concentrations of 0 (control), 2.5 or 5% for 104 wk. Surviving rats were then given a basal diet for a further 5 wk and killed at 109 wk. The dose levels were selected from the results of a 13-wk subchronic toxicity study. Dose-dependent inhibitory effects of β-cyclodextrin on growth were observed in both sexes of the treated groups. The survival rates, mean survival times and range, however, demonstrated no significant differences between the control and treated groups. A variety of tumours developed in all groups, including the control group, but all the neoplastic lesions were histologically similar to those known to occur spontaneously in this strain of rat, and no statistically significant increase in the incidence of any tumour was found for either sex of the treated groups. Thus, it is concluded that under the present experimental conditions, the high dose, about 340–400 times higher than the current daily human intake from ingestion as a food additive and from pharmaceutical use, does not have any carcinogenic potential in F344 rats.
- Published
- 1997
99. 2A2-H05 Operation of page turning machine baced on eyelid shape recognition : Shape approximation of eyelid using Bezier curve(Sense, Motion and Measurement (2))
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Michiko Ishibashi, Hiroki Murakawa, Nobuaki Nakazawa, and Mika Takahashi
- Subjects
medicine.anatomical_structure ,Shape approximation ,business.industry ,medicine ,Motion (geometry) ,Bézier curve ,Measurement 2 ,Computer vision ,Eyelid ,Artificial intelligence ,Sense (electronics) ,business ,Mathematics - Published
- 2013
- Full Text
- View/download PDF
100. 2A1-C07 System Constructions of Page Turning Machine by Gazing Actions(Sense, Motion and Measurement(1))
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Hiroki Murakawa, Mika Takahashi, Shinya Iizuka, and Nobuaki Nakazawa
- Subjects
Engineering ,Engineering drawing ,business.industry ,Sense (electronics) ,business ,Motion (physics) - Published
- 2012
- Full Text
- View/download PDF
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