46 results on '"Roos B"'
Search Results
2. Contributors
- Author
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Abe, C., primary, Accardi, G., additional, Andres-Lacueva, C., additional, Appendino, G., additional, Armentia, A., additional, Arora, R., additional, Azevedo, V., additional, Badole, S.L., additional, Bae, S.-C., additional, Baliga, M.S., additional, Balistreri, C.R., additional, Bermúdez-Humarán, L.G., additional, Bhat, H., additional, Bodhankar, S.L., additional, Bolling, S.F., additional, Bollor, R., additional, Bowden, R.G., additional, Bravo-Clouzet, R., additional, Calder, P.C., additional, Câmara, N.O.S., additional, Candore, G., additional, Castell, M., additional, Castellote, C., additional, Castrodeza, J., additional, Cerón, J.M., additional, Chacko, J., additional, Chowdhury, Z.T., additional, Comalada, M., additional, Contreras-Moreno, J., additional, Cordova, F.M., additional, Correa-Matos, N.J., additional, Crespo, J., additional, de Cienfuegos, G.Á., additional, de Gaetano, G., additional, de Luis, D., additional, de Moreno de LeBlanc, A., additional, de Pablo, M.A., additional, de Roos, B., additional, del Carmen, S., additional, Díaz, L.E., additional, di Giuseppe, R., additional, Donati, M.B., additional, Egger, G., additional, Elias, R.M., additional, Fayad, R., additional, Fazal, F., additional, Feleszko, W., additional, Fischer, A.K., additional, Franch, À., additional, Galena, A.E., additional, Gálvez, J., additional, Gómez-Martínez, S., additional, Graziano, C., additional, Hall, J., additional, Haniadka, R., additional, Hurst, R.D., additional, Hurst, S.M., additional, Iacoviello, L., additional, Inglada, L., additional, Jaffe, R., additional, Jaworska, J., additional, Kaufman, P.B., additional, Khan, N., additional, Kirakosyan, A., additional, Langella, P., additional, Latheef, L., additional, LeBlanc, J.G., additional, Llorach, R., additional, Lucas, E.A., additional, Malhotra, P., additional, Marcos, A., additional, Marín-Casino, M., additional, Martín-Armentia, S., additional, Mateu-de Antonio, J., additional, Menaa, A., additional, Menaa, B., additional, Menaa, F., additional, Mes, J., additional, Minato, K.I., additional, Miyoshi, A., additional, Monagas, M., additional, Moreillon, J., additional, Mullin, G.E., additional, Neyestani, T.R., additional, Oommen, B., additional, Pai, C., additional, Pai, R.J., additional, Pérez-Berezo, T., additional, Pérez-Cano, F.J., additional, Pérez de Heredia, F., additional, Petro, T.M., additional, Pozo-Rubio, T., additional, Prabhala, H.K., additional, Prabhala, R.H., additional, Pravettoni, V., additional, Prescott, S.L., additional, Primavesi, L., additional, Puertollano, E., additional, Puertollano, M.A., additional, Ramos-Romero, S., additional, Rastmanesh, R., additional, Rendina, E., additional, Romeo, J., additional, Sabetisoofyani, A., additional, Sampath, P., additional, Schauss, A.G., additional, Seymour, E.M., additional, Sharma, A., additional, Shelmadine, B., additional, Smith, B.J., additional, Somasundaram, S.G., additional, Sung, M.-K., additional, Togni, S., additional, Urpi-sarda, M., additional, Vaghefi, S.B., additional, Watson, R.R., additional, Weber, C.E., additional, West, C.E., additional, Wichers, H., additional, Wood, L.G., additional, Xaus, J., additional, Yashawanth, H.S., additional, and Zibadi, S., additional
- Published
- 2013
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3. The behaviour of Rn-222 decay products at the air–glass interface and its implication for retrospective radon exposure estimates
- Author
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Roos, B., primary and Samuelsson, C., additional
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- 2005
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4. Macrophage Functions in Immune Responses to Tumors
- Author
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Cottier, H., primary, Bürki, H., additional, Hess, M.W., additional, Keller, H.U., additional, and Roos, B., additional
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- 1975
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5. Discussion of 5-Hydroxyindoles in Phenylketonuric and Nonphenylketonuric Mental Defectives
- Author
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ROOS, B, primary
- Published
- 1968
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6. CHEMISTRY OF CYTOTOXIC SUBSTANCES IN AMPHIBIAN TOXINS
- Author
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BACHMAYER, H., primary, MICHL, H., additional, and ROOS, B., additional
- Published
- 1967
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7. How good are we at predicting the individual response to personalized diets?
- Author
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de Roos B
- Subjects
- Humans, Diet, Precision Medicine
- Published
- 2024
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8. The upper extremity postthrombotic syndrome score: an international Delphi consensus study to determine the score's functional disability component.
- Author
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Schropp L, Cats RB, de Kleijn RJCMF, van Hattum ES, Middeldorp S, Nijkeuter M, Westerink J, Petri BJ, and de Borst GJ
- Abstract
Background: In upper extremity thrombosis research, the occurrence of upper extremity postthrombotic syndrome (UE-PTS) is commonly used as the main outcome parameter. However, there is currently no reporting standard or a validated method to assess UE-PTS presence and severity. In a recent Delphi study, consensus was reached on a preliminary UE-PTS score, combining 5 symptoms, 3 signs, and the inclusion of a functional disability score. However, no consensus was reached on which functional disability score to be included., Objectives: The aim of the current Delphi consensus study was to determine the specific type of functional disability score to finalize UE-PTS score., Methods: This Delphi project was designed as a three-round study using open text questions, statements with 7-point Likert scales, and multiple-choice questions. The CREDES recommendations for Delphi studies were applied. In this context, a systematic review was conducted before the start of the Delphi rounds to identify the available functional disability scores as available in the literature and present these to the expert panel., Results: Thirty-five of 47 initially invited international experts from multiple disciplines completed all the Delphi rounds. In the second round, consensus was reached on the incorporation of the quick disabilities of the arm, shoulder, and hand (QuickDASH) in the UE-PTS score, rendering the third round obsolete., Conclusion: Consensus was reached that the QuickDASH should be incorporated in the UE-PTS score. The UE-PTS score will need to be validated in a large cohort of patients with upper extremity thrombosis before it can be used in clinical practice and future research., (© 2023 The Author(s).)
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- 2023
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9. Diet, blood pressure, and heart disease-precision nutrition approaches to understand response to diet and predict disease risk.
- Author
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de Roos B
- Subjects
- Blood Pressure, Humans, Nutritional Status, Diet, Heart Diseases
- Published
- 2021
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10. Nicotinic α7 acetylcholine receptor (α7nAChR) in human airway smooth muscle.
- Author
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Borkar NA, Roos B, Prakash YS, Sathish V, and Pabelick CM
- Subjects
- Adult, Aged, Aged, 80 and over, Asthma metabolism, Asthma pathology, Bronchi drug effects, Bronchi metabolism, Bronchi pathology, Cigarette Smoking adverse effects, Cyclic AMP Response Element-Binding Protein genetics, Cyclic AMP Response Element-Binding Protein metabolism, Female, Gene Expression Regulation, Humans, Interleukin-13 pharmacology, Male, Middle Aged, Muscle, Smooth drug effects, Muscle, Smooth metabolism, Muscle, Smooth pathology, Myocytes, Smooth Muscle metabolism, Myocytes, Smooth Muscle pathology, NF-kappa B genetics, NF-kappa B metabolism, Primary Cell Culture, Protein Isoforms genetics, Protein Isoforms metabolism, Severity of Illness Index, Transcription Factor AP-1 genetics, Transcription Factor AP-1 metabolism, Tumor Necrosis Factor-alpha pharmacology, alpha7 Nicotinic Acetylcholine Receptor metabolism, Asthma genetics, Bronchoconstriction drug effects, Complex Mixtures pharmacology, Myocytes, Smooth Muscle drug effects, Nicotine pharmacology, alpha7 Nicotinic Acetylcholine Receptor genetics
- Abstract
Diseases such as asthma are exacerbated by inflammation, cigarette smoke and even nicotine delivery devices such as e-cigarettes. However, there is currently little information on how nicotine affects airways, particularly in humans, and changes in the context of inflammation or asthma. Here, a longstanding assumption is that airway smooth muscle (ASM) that is key to bronchoconstriction has muscarinic receptors while nicotinic receptors (nAChRs) are only on airway neurons. In this study, we tested the hypothesis that human ASM expresses α7nAChR and explored its profile in inflammation and asthma using ASM of non-asthmatics vs. mild-moderate asthmatics. mRNA and western analysis showed the α7 subunit is most expressed in ASM cells and further increased in asthmatics and smokers, or by exposure to nicotine, cigarette smoke or pro-inflammatory cytokines TNFα and IL-13. In these effects, signaling pathways relevant to asthma such as NFκB, AP-1 and CREB are involved. These novel data demonstrate the expression of α7nAChR in human ASM and suggest their potential role in asthma pathophysiology in the context of nicotine exposure., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2021
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11. Perspective: Application of N-of-1 Methods in Personalized Nutrition Research.
- Author
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Potter T, Vieira R, and de Roos B
- Subjects
- Data Collection, Humans, Research Design, Diet, Feeding Behavior
- Abstract
Personalized and precision nutrition aim to examine and improve health on an individual level, and this requires reconsideration of traditional dietary interventions or behavioral study designs. The limited frequency of measurements in group-level human nutrition trials cannot be used to infer individual responses to interventions, while in behavioral studies, retrospective data collection does not provide an accurate measure of how everyday behaviors affect individual health. This review introduces the concept of N-of-1 study designs, which involve the repeated measurement of a health outcome or behavior on an individual level. Observational designs can be used to monitor a participant's usual health or behavior in a naturalistic setting, with repeated measurements conducted in real time using an Ecological Momentary Assessment. Interventional designs can introduce a dietary or behavioral intervention with predictors and outcomes of interest measured repeatedly either during or after 1 or more intervention and control periods. Due to their flexibility, N-of-1 designs can be applied to both short-term physiological studies and longer-term studies of eating behaviors. As a growing number of disease markers can be measured outside of the clinic, with self-reported data delivered via electronic devices, it is now easier than ever to generate large amounts of data on an individual level. Statistical techniques can be utilized to analyze changes in an individual or to aggregate data from sets of N-of-1 trials, enabling hypotheses to be tested on a small number of heterogeneous individuals. Although their designs necessitate extra methodological and statistical considerations, N-of-1 studies could be used to investigate complex research questions and to study underrepresented groups. This may help to reveal novel associations between participant characteristics and health outcomes, with repeated measures providing power and precision to accurately determine an individual's health status., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)
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- 2021
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12. Nutrigenomics: lessons learned and future perspectives.
- Author
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Brennan L and de Roos B
- Subjects
- Biomarkers, Eating, Humans, Nutritional Status, Precision Medicine, Weight Loss, Nutrigenomics, Research Design
- Abstract
The omics technologies of metabolomics, transcriptomics, proteomics, and metagenomics are playing an increasingly important role in nutrition science. With the emergence of the concept of precision nutrition and the need to understand individual responses to dietary interventions, it is an opportune time to examine the impact of these tools to date in human nutrition studies. Advances in our mechanistic understanding of dietary interventions were realized through incorporation of metabolomics, proteomics, and, more recently, metagenomics. A common observation across the studies was the low intra-individual variability of the omics measurements and the high inter-individual variation. Harnessing this data for use in the development of precision nutrition will be important. Metabolomics in particular has played a key role in the development of biomarkers of food intake in an effort to enhance the accuracy of dietary assessments. Further work is needed to realize the full potential of such biomarkers and to demonstrate integration with current strategies, with the goal of overcoming the well-established limitations of self-reported approaches. Although many of the nutrigenomic studies performed to date were labelled as proof-of-concept or pilot studies, there is ample evidence to support the use of these technologies in nutrition science. Incorporating omic technologies from the start of study designs will ensure that studies are sufficiently powered for such data. Furthermore, multi-disciplinary collaborations are likely to become even more important to aid analyses and interpretation of the data., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)
- Published
- 2021
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13. Arthroscopic Subcapital Realignment in Chronic and Stable Slipped Capital Femoral Epiphysis.
- Author
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Dutra Roos B, Camargo de Assis M, Roos MV, Camisa Júnior A, and Ungaretti Lima EM
- Abstract
Stable slipped capital femoral epiphysis (SCFE) is the most common disease in the adolescent hip, with an estimated frequency of 10.8 in every 100,000 individuals. Recent studies of the biomechanics of femoroacetabular impingement indicate that small anatomical deformities of the hip arising from SCFE can potentially cause permanent acetabular chondral damage. There is no consensus about the best treatment option, especially for cases of moderate or severe chronic slippage (Southwick classification). Some authors recommend treatment with fixation in situ, in the belief that remodeling of the residual deformity of the femoral neck during growth allows proper function of the hip joint. Others recommend correction at the site of the deformity (subcapital realignment), aiming for the anatomical reduction of the epiphysis and seeking to reduce the risk of chondral degeneration. The authors of this Technical Note present an alternative to the classical techniques of subcapital realignment for the treatment of moderate and severe chronic and stable SCFE, which allows adequate access to the hip joint and anatomical reduction of the slippage, besides having the theoretical advantage of rapid rehabilitation of the patient.
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- 2017
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14. Proteomic approaches to predict bioavailability of fatty acids and their influence on cancer and chronic disease prevention.
- Author
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de Roos B and Romagnolo DF
- Subjects
- Biological Availability, Biomarkers metabolism, Dietary Fats adverse effects, Fatty Acids pharmacokinetics, Humans, Neoplasms etiology, Protein Processing, Post-Translational, Chronic Disease prevention & control, Diet, Dietary Fats therapeutic use, Fatty Acids therapeutic use, Neoplasms prevention & control, Proteome metabolism, Proteomics
- Abstract
A low intake of fish and PUFA and high dietary trans- and SFA are considered to be among the main preventable causes of death. Unfortunately, epidemiological and preclinical studies have yet to identify biomarkers that accurately predict the influence of fatty acid intake on risk of chronic diseases, including cancer. Changes in protein profile and post-translational modifications in tissue and biofluids may offer important clues about the impact of fatty acids on the etiology of chronic diseases. However, conventional protein methodologies are not adequate for assessing the impact of fatty acids on protein expression patterns and modifications and the discovery of protein biomarkers that predict changes in disease risk and progression in response to fatty acid intake. Although fluctuations in protein structure and abundance and inter-individual variability often mask subtle effects caused by dietary intervention, modern proteomic platforms offer tremendous opportunities to increase the sensitivity of protein analysis in tissues and biofluids (plasma, urine) and elucidate the effects of fatty acids on regulation of protein networks. Unfortunately, the number of studies that adopted proteomic tools to investigate the impact of fatty acids on disease risk and progression is quite small. The future success of proteomics in the discovery of biomarkers of fatty acid nutrition requires improved accessibility and standardization of proteomic methodologies, validation of quantitative and qualitative protein changes (e.g., expression levels, post-translational modifications) induced by fatty acids, and application of bioinformatic tools that can inform about the cause-effect relationships between fatty acid intake and health response.
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- 2012
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15. Human O-sulfated metabolites of (-)-epicatechin and methyl-(-)-epicatechin are poor substrates for commercial aryl-sulfatases: implications for studies concerned with quantifying epicatechin bioavailability.
- Author
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Saha S, Hollands W, Needs PW, Ostertag LM, de Roos B, Duthie GG, and Kroon PA
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- Administration, Oral, Biological Availability, Biotransformation, Catechin administration & dosage, Catechin blood, Catechin metabolism, Catechin urine, Chromatography, Liquid, Cross-Over Studies, England, Female, Glucuronidase metabolism, Humans, Hydrogen-Ion Concentration, Hydrolysis, Male, Methylation, Reproducibility of Results, Substrate Specificity, Sulfuric Acid Esters administration & dosage, Sulfuric Acid Esters blood, Sulfuric Acid Esters urine, Tandem Mass Spectrometry, Time Factors, Arylsulfatases metabolism, Catechin analogs & derivatives, Sulfuric Acid Esters metabolism
- Abstract
Epicatechin is a widely consumed dietary flavonoid and there is substantial evidence that it contributes to the health benefits reported for flavanol-rich cocoa products including dark chocolate. Numerous reports have described the appearance of epicatechin and epicatechin phase-2 conjugates (sulfates and glucuronides of epicatechin and methylepicatechin) in blood and urine samples of subjects following ingestion of epicatechin. The most widely reported method of quantifying total epicatechin in plasma and urine samples involves hydrolysis with a mixture of β-glucuronidase and sulfatase to convert the conjugates to epicatechin aglycone which is subsequently quantified. We observed a lack of hydrolysis of epicatechin sulfates and methylepicatechin sulfates using commercial sulfatases and investigated this further. Samples of urine or plasma from subjects who had consumed epicatechin were subjected to enzyme hydrolysis and then analysed using LC-MS/MS, or analysed without enzyme hydrolysis. Attempts to increase the extent of hydrolysis of epicatechin conjugates were made by increasing the amount of enzyme, hydrolysis pH and length of incubations, and using alternative sources of enzyme. The standard hydrolysis conditions failed to hydrolyse the majority of epicatechin sulfates and methylepicatechin sulfates. Even when the quantity of enzyme and incubation period was increased, the pH optimised, or alternative sources of sulfatases were used, epicatechin monosulfates and methylepicatechin monosulfates remained as major peaks in the chromatograms of the samples. An assessment of literature data strongly suggested that the majority of reports where enzyme hydrolysis was used had significantly underestimated epicatechin bioavailability in humans. Methods for quantifying epicatechin concentrations in blood and urine need to take account of the lack of hydrolysis of (methyl)epicatechin-sulfates, for example by quantifying these directly using LC-MS/MS., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
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- 2012
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16. Dietary supplementation with cis-9,trans-11 conjugated linoleic acid and aortic stiffness in overweight and obese adults.
- Author
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Sluijs I, Plantinga Y, de Roos B, Mennen LI, and Bots ML
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- Adult, Aged, Aorta drug effects, Atherosclerosis prevention & control, Blood Pressure drug effects, Body Composition drug effects, Body Mass Index, C-Reactive Protein drug effects, C-Reactive Protein metabolism, Cardiovascular Diseases prevention & control, Double-Blind Method, Humans, Insulin Resistance physiology, Linoleic Acids, Conjugated administration & dosage, Middle Aged, Placebos, Pulse, Risk Factors, Waist-Hip Ratio, Aorta physiopathology, Dietary Supplements, Linoleic Acids, Conjugated pharmacology, Obesity physiopathology, Overweight physiopathology
- Abstract
Background: Animal studies suggest that dietary cis-9,trans-11 (c9,t11) conjugated linoleic acid (CLA) may inhibit or regress the development of atherosclerosis. The effect of CLA on atherosclerosis has not been assessed in humans., Objective: We investigated the effect of c9,t11 CLA supplementation on aortic pulse wave velocity (a marker of atherosclerosis) and on cardiovascular risk factors in overweight and obese but otherwise apparently healthy subjects., Design: In a double-blind, randomized, placebo-controlled, parallel-group trial, we randomly assigned 401 subjects, aged 40-70 y and with a body mass index (in kg/m(2)) > or = 25, to receive either 4 g CLA/d (2.5 g c9,t11 CLA/d and 0.6 g trans-10,cis-12 CLA/d) or placebo supplements for 6 mo. Aortic pulse wave velocity, blood pressure, anthropometric characteristics, and concentrations of fasting lipid, glucose, insulin, and C-reactive protein were measured before and after supplementation., Results: During the intervention, mean (+/-SE) pulse wave velocity did not change in the c9,t11 CLA group (Delta0.00 +/- 0.07) compared with the placebo group (Delta0.09 +/- 0.06). There was no effect of c9,t11 CLA supplementation on blood pressure, body composition, insulin resistance, or concentrations of lipid, glucose, and C-reactive protein., Conclusion: This study does not support an antiatherosclerotic effect or an effect on cardiovascular risk factors of c9,t11 CLA. This trial was registered at www.clinicaltrials.gov as NCT00706745.
- Published
- 2010
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17. Quantification of sugar phosphate intermediates of the pentose phosphate pathway by LC-MS/MS: application to two new inherited defects of metabolism.
- Author
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Wamelink MM, Struys EA, Huck JH, Roos B, van der Knaap MS, Jakobs C, and Verhoeven NM
- Subjects
- Cells, Cultured, Fibroblasts chemistry, Fibroblasts cytology, Fibroblasts enzymology, Humans, Lymphocytes chemistry, Lymphocytes cytology, Lymphocytes enzymology, Metabolism, Inborn Errors diagnosis, Metabolism, Inborn Errors metabolism, Reference Values, Reproducibility of Results, Sugar Phosphates blood, Sugar Phosphates metabolism, Transaldolase metabolism, Transketolase metabolism, Chromatography, Liquid methods, Pentose Phosphate Pathway, Spectrometry, Mass, Electrospray Ionization methods, Sugar Phosphates analysis
- Abstract
We describe a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to quantify pentose phosphate pathway intermediates (triose-3-phosphates, tetrose-4-phosphate, pentose-5-phosphate, pentulose-5-phosphates, hexose-6-phosphates and sedoheptulose-7-phosphate (sed-7P)) in bloodspots, fibroblasts and lymphoblasts. Liquid chromatography was performed using an ion pair loaded C(18) HPLC column and detection of the sugar phosphates was carried out by tandem mass spectrometry using an electron ion spray source operating in the negative mode and multiple reaction monitoring. Reference values for the pentose phosphate pathway intermediates in blood spots, fibroblasts and lymphoblasts were established. The method was applied to cells from patients affected with a deficiency of transaldolase. The transaldolase-deficient cells showed an increased concentration of sedoheptulose-7-phosphate. (Bloodspots: 5.19 and 5.43 micromol/L [0.49-3.33 micromol/L]; fibroblasts 7.43 and 26.46 micromol/mg protein [0.31-1.14 micromol/mg protein]; lymphoblasts 16.03 micromol/mg protein [0.61-2.09 micromol/mg protein].) The method was also applied to study enzymes of the pentose phosphate pathway by incubating fibroblasts or lymphoblasts homogenates with ribose-5-phosphate or 6-phosphogluconate and the subsequent analysis of the formed sugar phosphates.
- Published
- 2005
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18. Characterisation of the lipoprotein structure in the St. Thomas' Mixed Hyperlipidaemic (SMHL) rabbit.
- Author
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de Roos B, Caslake MJ, Milliner K, Benson GM, Suckling KE, and Packard CJ
- Subjects
- Animals, Apolipoproteins B blood, Cholesterol blood, Lipoproteins, IDL, Male, Phosphatidylcholines blood, Phospholipids blood, Rabbits, Sphingomyelins blood, Triglycerides blood, Hyperlipidemia, Familial Combined blood, Lipoproteins blood, Lipoproteins, LDL blood, Lipoproteins, VLDL blood
- Abstract
Familial combined hyperlipidaemia (FCHL) is a complex genetic disorder of unknown aetiology. Study of this human condition over many decades has been hampered by likely genetic heterogeneity. In order to find better phenotypic markers, we have characterised the structures of VLDL, IDL and LDL in the St. Thomas' Mixed Hyperlipidaemic (SMHL) rabbit--an animal model of FCHL in which the hyperlipidaemia is caused primarily by an increased production rate of apolipoprotein B (apoB)--containing lipoproteins-and compared them with those in the Watanabe Heritable Hyperlipidaemic (WHHL) rabbit, in which hyperlipidaemia is caused mainly by a defect in lipoprotein clearance, and those in the normolipidaemic New Zealand White (NZW) animal. All three rabbit strains were fed a cholesterol-enriched (0.08%, w/w) diet for at least 3 months prior to blood sampling. Both SMHL and WHHL rabbits showed combined hyperlipidaemia as evidenced by significantly increased levels of plasma cholesterol and triglycerides. Raised plasma lipids in the SMHL rabbit were attributable mainly to an overabundance of lipoprotein particles with the same lipid composition as those in NZW rabbits. VLDL and IDL in the SMHL rabbit showed a significantly increased sphingomyelin to phosphatidyl choline ratio. In the WHHL rabbit there was a high concentration of particles that were significantly enriched in cholesteryl esters and depleted in triglycerides. Phospholipids in all lipoprotein fractions from WHHL rabbits contained significantly more sphingomyelin and less phosphatidyl choline resulting in a significantly increased sphingomyelin to phosphatidyl choline ratio. We found that the VLDL of SMHL rabbits could be distinguished from that of NZW rabbits on the basis of the cholesterol:apoB and the sphingomyelin:phosphatidylcholine ratios, and from that of WHHL rabbits by the sphingomyelin:triglyceride ratio. Extrapolating these findings to the human condition, an assessment of particle core composition, together with the proportion of sphingomyelin in phospholipids especially in VLDL might help in the differentiation of the combined hyperlipidaemia of FCHL into disorders of lipoprotein overproduction versus decreased clearance.
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- 2005
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19. 2-Methoxyestradiol induces G2/M arrest and apoptosis in prostate cancer.
- Author
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Qadan LR, Perez-Stable CM, Anderson C, D'Ippolito G, Herron A, Howard GA, and Roos BA
- Subjects
- 2-Methoxyestradiol, Administration, Oral, Amino Acid Chloromethyl Ketones pharmacology, Animals, Annexin A5 analysis, Antineoplastic Agents administration & dosage, Caspase Inhibitors, Cell Division drug effects, Cell Nucleus drug effects, Disease Models, Animal, Disease Progression, Dose-Response Relationship, Drug, Drug Implants, Drug Resistance, Neoplasm, Enzyme Inhibitors pharmacology, Estradiol administration & dosage, Estradiol analogs & derivatives, Flow Cytometry, Humans, Male, Mice, Mice, Transgenic, Prostatic Neoplasms chemistry, Prostatic Neoplasms pathology, Tumor Cells, Cultured, Antineoplastic Agents pharmacology, Apoptosis drug effects, Estradiol pharmacology, G2 Phase drug effects, Mitosis drug effects, Prostatic Neoplasms drug therapy
- Abstract
Few therapeutic treatment options are available for patients suffering from metastatic androgen-independent prostate cancer. We investigated the ability of the estrogen metabolite 2-methoxyestradiol to inhibit the proliferation of a variety of human prostate cancer cell lines in vitro and to inhibit the growth of androgen-independent prostate cancer in a transgenic mouse model in vivo. Our results showed that 2-methoxyestradiol is a powerful growth inhibitor of LNCaP, DU 145, PC-3, and ALVA-31 prostate cancer cells. Cell flow cytometry of 2-methoxyestradiol-treated DU 145 cells showed a marked accumulation of cells in the G2/M phase of the cell cycle and an increase in the sub-G1 fraction (apoptotic). In addition, staining for annexin V, changes in nuclear morphology, and inhibition of caspase activity support a role for apoptosis. More importantly, we showed that 2-methoxyestradiol inhibits prostate tumor progression in the Ggamma/T-15 transgenic mouse model of androgen-independent prostate cancer without toxic side effects. These results in cell culture and an animal model support investigations into the clinical use of 2-methoxyestradiol in patients with androgen-independent prostate cancer., (Copyright 2001 Academic Press.)
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- 2001
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20. Insulin resistance in the St. Thomas' mixed hyperlipidaemic (SMHL) rabbit, a model for familial combined hyperlipidaemia.
- Author
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de Roos B, Caslake MJ, Ardern HA, Martin Benson G, Suckling KE, and Packard CJ
- Subjects
- Animals, Area Under Curve, Cholesterol, Dietary administration & dosage, Cholesterol, Dietary metabolism, Disease Models, Animal, Glucose Tolerance Test, Hyperinsulinism complications, Hyperlipidemia, Familial Combined complications, Hypertriglyceridemia complications, Insulin pharmacokinetics, Male, Probability, Rabbits, Radioimmunoassay, Reference Values, Risk Assessment, Sensitivity and Specificity, Blood Glucose metabolism, Hyperinsulinism physiopathology, Hyperlipidemia, Familial Combined physiopathology, Hypertriglyceridemia physiopathology, Insulin metabolism, Insulin Resistance physiology
- Abstract
The St. Thomas mixed hyperlipidaemic (SMHL) rabbit exhibits an inherited hyperlipidaemia similar to that seen in familial combined hyperlipidaemia (FCHL). In this study, we investigated whether the SMHL rabbit is insulin resistant, a condition often associated with FCHL. Six young and six mature combined hyperlipidaemic SMHL rabbits, age/sex matched New Zealand White (NZW) control rabbits and six young hypercholesterolaemic Watanabe heritable hyperlipidaemic (WHHL) control rabbits were fed a 0.08% (w/w) cholesterol-enriched diet for at least 1 month prior to the start of the experiment. We performed an oral glucose tolerance test after an overnight fast by dosing the rabbits with a solution of 1 g of glucose per kg body weight. Blood was withdrawn just before and 15, 30, 45, 60 and 120 min after administration of the oral glucose dose. Plasma glucose levels were similar in SMHL, WHHL and NZW rabbits throughout the oral glucose tolerance test. Fasting glucose levels were slightly increased in WHHL rabbits but not in young and adult SMHL rabbits as compared to NZW rabbits. The area under the curve (AUC) for the insulin response was significantly increased for both young (P<0.05) and mature (P<0.05) SMHL rabbits, and in WHHL rabbits, compared with NZW rabbits. The AUC for the ratio of glucose:insulin response to the glucose dose was decreased in young and mature SMHL rabbits (P<0.05 and P<0.01, respectively) and in young WHHL rabbits (P<0.05), compared with NZW rabbits. Only WHHL rabbits showed an increased AUC for the non-esterified fatty acid response compared to NZW rabbits. Log-transformed plasma triglycerides values were significantly correlated with the log-transformed AUC for the insulin response in young SMHL rabbits (r=0.81; P<0.05) and with the AUC for the insulin response in mature SMHL rabbits (r=0.84; P<0.05). WHHL rabbits showed no significant correlation. In conclusion, SMHL rabbits are insulin resistant, the severity of which appears to increase with age. Therefore, the SMHL rabbit offers a valuable animal model in which to study the relation between hypertriglyceridaemia and insulin resistance.
- Published
- 2001
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21. Alpha particle emission from reference glass surfaces implanted with 210Po.
- Author
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Samuelsson C, Falk R, and Roos B
- Abstract
Implanted long-lived radon decay products in glass surfaces have been used as a measure of past radon exposure in homes. Special track-etch devices (so-called 'retro-detectors') attached to the glass surface, have the ability to specifically measure the implanted activity of 210Po in situ. Calibrating these devices for 210Po is fairly straightforward, but the retro-detectors are also sensitive to the background activity of the glass substrate. Thus, for the successful calibration of retro-detectors, it is necessary to determine the complete alpha emission energy spectrum of the reference glass sheet utilised as a calibration pad. In order to achieve accurate knowledge of the alpha surface emission rate, we have combined several different approaches, i.e. alpha spectrometry of the pad surface with both surface-barrier and pulse-ionisation detectors, and activity determination of the glass matrix by means of radiochemical methods. The part of the alpha emission spectrum originating from the glass volume is then calculated theoretically and compared with experimental results.
- Published
- 2001
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22. The coffee diterpene cafestol increases plasma triacylglycerol by increasing the production rate of large VLDL apolipoprotein B in healthy normolipidemic subjects.
- Author
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de Roos B, Caslake MJ, Stalenhoef AF, Bedford D, Demacker PN, Katan MB, and Packard CJ
- Subjects
- Adult, Alanine Transaminase blood, Apolipoproteins B metabolism, Humans, Lipid Metabolism, Lipids pharmacokinetics, Lipoproteins, VLDL chemistry, Lipoproteins, VLDL metabolism, Liver drug effects, Liver metabolism, Male, Models, Biological, Time Factors, Apolipoproteins B biosynthesis, Coffee chemistry, Diterpenes pharmacology, Lipoproteins, VLDL biosynthesis, Triglycerides blood
- Abstract
Background: Cafestol is a diterpene in unfiltered coffee that raises plasma triacylglycerol in humans., Objective: We studied whether cafestol increases plasma triacylglycerol by increasing the production rate or by decreasing the fractional catabolic rate of VLDL(1) [Svedberg flotation unit (S(f)) 60-400] apolipoprotein (apo) B. In addition, we studied the effect of cafestol on the composition of VLDL(1) and VLDL(2) (S(f) 20-60)., Design: Eight healthy normolipidemic men were administered a daily dose of 75 mg cafestol for 2 wk. A bolus injection of 7 mg L-[5,5,5-(2)H(3)]leucine/kg body wt was given after a baseline period with no cafestol and again after treatment with cafestol. We derived kinetic constants to describe the metabolism of VLDL(1) apo B by using a multicompartmental model., Results: Cafestol significantly increased plasma triacylglycerol by 31% or 0.32 mmol/L (95% CI: 0.03, 0.61); the increase was due mainly to a nonsignificant rise in VLDL(1) triacylglycerol of 57% or 0.23 mmol/L (95% CI: -0.02, 0.48). Cafestol significantly increased the mean rate of VLDL(1) apo B production by 80% or 755 mg/d (95% CI: 0.2, 5353), whereas it did not significantly change the mean fractional catabolic rate of VLDL(1) apo B (mean increase of 3 pools/d; 95% CI: -4, 10]). Cafestol did not change the composition of VLDL(1). A significant increase in the ratio of VLDL(2) cholesteryl ester to triacylglycerol indicates that VLDL(2) became enriched with cholesteryl esters at the cost of triacylglycerol., Conclusion: Cafestol increases plasma triacylglycerol by increasing the production rate of VLDL(1) apo B, probably via increased assembly of VLDL(1) in the liver.
- Published
- 2001
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23. Analysis of DES-induced micronuclei in binucleated rat fibroblasts: comparison between FISH with a rat satellite I probe and immunocytochemical staining with CREST serum.
- Author
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de Stoppelaar JM, de Roos B, Mohn GR, and Hoebee B
- Subjects
- Animals, Autoantibodies, CREST Syndrome immunology, Cells, Cultured, Centromere genetics, DNA, Satellite, Diethylstilbestrol, Fibroblasts, Humans, Male, Mitomycin, Mutagens, Rats, Rats, Wistar, DNA Probes, Fluorescent Antibody Technique, Indirect methods, In Situ Hybridization, Fluorescence methods, Micronucleus Tests methods
- Abstract
The usefulness of fluorescence in situ hybridization (FISH) with rat satellite I DNA was compared with immunocytochemical staining with CREST serum for the analysis of the content of micronuclei from primary rat fibroblasts. We analyzed micronuclei induced in vitro by the aneugenic compound diethylstilbestrol (DES) or the clastogenic compound mitomycin C (MMC). Since a centromeric probe was not available for the rat, we isolated rat satellite I DNA by PCR with primers designed on the basis of the known rat satellite I DNA sequence. The PCR products obtained as well as the cloned PCR products showed hybridization to the centromeric regions of a large number of chromosomes, but not of chromosome 1, 19, 20, X and Y. Clone 18-5 was further analyzed and was shown to contain at least 4 repeats of the rat satellite I family. This probe, which hybridizes in the centromeric region of 34 of the 42 chromosomes, was used throughout the study as a probe for the FISH analysis of the micronuclei. For the immunocytochemical staining, the commonly used commercial anti-centromeric antibodies could not be used because of the weakness of the fluorescent signals given. Consequently, CREST serum of a single patient was used, which showed bright and distinct signals on the kinetochores of each chromosome. After treatment of the cells with the aneugen DES an increase in centromere (FISH) and kinetochore (CREST) positive micronuclei was found, whereas after treatment with the clastogen MMC, the percentage of centromere-positive micronuclei was similar to that observed in controls. Analysis of a large number of DES-induced micronuclei showed that the immunocytochemical method is equally as or slightly less sensitive for the detection of chromosomes in micronuclei and we therefore recommend FISH with probe 18-5 for the detection of chromosome loss in rat cells.
- Published
- 1997
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24. The cholesterol-raising diterpenes from coffee beans increase serum lipid transfer protein activity levels in humans.
- Author
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van Tol A, Urgert R, de Jong-Caesar R, van Gent T, Scheek LM, de Roos B, and Katan MB
- Subjects
- Adult, Coffee adverse effects, Humans, Lipoproteins, HDL blood, Lipoproteins, LDL blood, Lipoproteins, VLDL blood, Male, Carrier Proteins blood, Diterpenes administration & dosage
- Abstract
Cafestol and kahweol-diterpenes present in unfiltered coffee-strongly raise serum VLDL and LDL cholesterol and slightly reduce HDL cholesterol in humans. The mechanism of action is unknown. We determined whether the coffee diterpenes may affect lipoprotein metabolism via effects on lipid transfer proteins and lecithin:cholesterol acyltransferase in a randomized, double-blind cross-over study with 10 healthy male volunteers. Either cafestol (61-64 mg/day) or a mixture of cafestol (60 mg/day) and kahweol (48-54 mg/day) was given for 28 days. Serum activity levels of cholesterylester transfer protein, phospholipid transfer protein and lecithin:cholesterol acyltransferase were measured using exogenous substrate assays. Relative to baseline values, cafestol raised the mean (+/- S.D.) activity of cholesterylester transfer protein by 18 +/- 12% and of phospholipid transfer protein by 21 +/- 14% (both P < 0.001). Relative to cafestol alone, kahweol had no significant additional effects Lecithin:cholesterol acyltransferase activity was reduced by 11 +/- 12% by cafestol plus kahweol (P = 0.02). It is concluded that the effects of coffee diterpenes on plasma lipoproteins may be connected with changes in serum activity levels of lipid transfer proteins.
- Published
- 1997
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25. The cupric geometry of blue copper proteins is not strained.
- Author
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Ryde U, Olsson MH, Pierloot K, and Roos BO
- Subjects
- Ligands, Oxidation-Reduction, Protein Conformation, Quantum Theory, Vacuum, Bacterial Proteins chemistry, Copper chemistry, Models, Molecular
- Abstract
The geometry of several realistic models of the metal coordination sphere in the blue copper proteins has been optimised using high-level quantum chemical methods. The results show that the optimal vacuum structure of the Cu(II) models is virtually identical to the crystal structure of oxidised blue copper proteins. For the reduced forms, the optimised structure seems to be more tetrahedral than the one found in the proteins, but the energy difference between the two geometries is less than 5 kJ/mol, i.e. within the error limits of the method. Thus, the results raise strong doubts against hypotheses (entatic state and the induced-rack theory) suggesting that blue copper proteins force the oxidised metal coordination sphere into a structure similar to that preferred by Cu(I) in order to minimise the reorganisation energy of the electron transfer reaction. Instead, a small reorganisation energy seems to be reached by an appropriate choice of metal ligands. In particular, the cysteine thiolate ligand appears to be crucial, changing the preferred geometry of the oxidised complexes from square-planar to a more trigonal geometry.
- Published
- 1996
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26. Review of the literature: severe hyperphosphatemia.
- Author
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Thatte L, Oster JR, Singer I, Bourgoignie JJ, Fishman LM, and Roos BA
- Subjects
- Acid-Base Equilibrium, Acidosis, Lactic blood, Acute Kidney Injury blood, Adult, Humans, Male, Phosphorus administration & dosage, Phosphorus blood
- Abstract
A patient with a markedly elevated serum phosphorus level (23.9 mg/dL) is described, followed by a brief review of severe hyperphosphatemia. Elevated serum phosphorus levels may be artifactual or true. True hyperphosphatemia is usefully subdivided according to (a) whether phosphorus is added to the extracellular fluid from a variety of exogenous or endogenous sources, or (b) whether the urinary excretion of phosphorus is reduced from either decreased glomerular filtration or increased tubular reabsorption. Severe hyperphosphatemia, defined herein as levels of 14 mg/dL or higher, is almost invariably multifactorial--usually resulting from addition of phosphorus to the extracellular fluid together with decreased phosphorus excretion. The hyperphosphatemia of the patient described herein appeared to result from a combination of dietary phosphorus supplementation, acute renal failure, acute pancreatitis, and ischemic bowel disease, complicated by lactic acidosis.
- Published
- 1995
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27. Observation of movements during sleep in ALTE (apparent life threatening event) and apnoeic infants--a pilot study.
- Author
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Einspieler C, Prechtl HF, van Eykern L, and de Roos B
- Subjects
- Aging, Electrocardiography, Electroencephalography, Electromyography, Electrooculography, Heart Rate, Humans, Infant, Pilot Projects, Respiration, Sleep physiology, Sleep, REM physiology, Video Recording, Movement, Sleep Apnea Syndromes physiopathology
- Abstract
Fourteen infants of 2 months or 6 months of age were video-recorded during polysomnography. Four were normal infants, five had a history of ALTE (apparent life threatening event) and five had repeated and prolonged apnoea during sleep. Two ALTE infants have been recorded at 2 months as well as at 6 months of age. Movements during sleep could be classified into general movements, isolated movements of the upper extremity, startles, head rotations, and trunk rotations. In the ALTE cases at 2 months of age, the motility was quantitatively not different from the control infants but was markedly reduced at 6 months of age. (All cases had their event before 8 weeks of age.) In contrast to these findings, infants with repeated apnoea did not show a clear change in the quantity of their movements. With the exception of one ALTE case at 2 months, all observed cases of ALTE and apnoeic infants showed an abnormal quality of their spontaneous movements during sleep. As reported in a previous study, all these cases had also been found moving abnormally during wakefulness. It is suggested that the abnormal motility is a sequelae of the event (ALTE or repeated apnoeas) with as a consequence, an impairment of neural functions.
- Published
- 1994
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28. Sleep disturbances in patients with asthma.
- Author
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Janson C, Gislason T, Boman G, Hetta J, and Roos BE
- Subjects
- Acute Disease, Adolescent, Adult, Aged, Asthma drug therapy, Asthma physiopathology, Female, Forced Expiratory Volume, Humans, Male, Middle Aged, Prospective Studies, Asthma complications, Sleep Wake Disorders etiology
- Abstract
The prevalence of sleep complaints and sleep disturbances was studied prospectively in 98 consecutive adult asthmatic patients (mean age 45 years, 46% men) attending an out-patient clinic by means of questionnaires and sleep diaries. The results were compared with those from an age- and sex-matched group of 226 healthy individuals. The most common sleep disturbances among the asthmatic patients were early morning awakening (51%), difficulty in maintaining sleep (DMS; 44%) and daytime sleepiness (44%). With decreasing asthma control (i.e. increased number of acute asthmatic attacks) there was an increase of DMS, nocturnal wakefulness, nocturnal breathing problems and bronchodilator inhalations at night. A decrease in estimated sleep time (P less than 0.05) and increase in nocturnal wakefulness (P less than 0.05) was seen with decreasing daytime FEV1--measured as percentage of the predicted value (%FEV1). There was also significant correlation between increasing age and decreasing %FEV1 (P less than 0.01). Among the 26 patients who were only taking one oral bronchodilator, no definite difference regarding sleep quality was found between those treated with theophylline and those taking an oral beta 2-agonist. The prevalence rates of DIS, DMS and daytime sleepiness were about twice as high among the asthmatic patients than in the healthy population. It is concluded that impaired quality of sleep, with disturbed sleep during the night, early morning awakenings and daytime sleepiness, is common among patients with bronchial asthma.
- Published
- 1990
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29. Retraction: Concurrent measurements of plasma levels of vitamin D3 and five of its metabolites in normal humans, chronic renal failure patients, and anephric subjects.
- Author
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Lambert PW, DeOreo PB, Hollis B, Fu IY, Ginsberg DJ, Roos B, and Behrman RE
- Published
- 1984
30. Concurrent measurement of plasma levels of vitamin D3 and five of its metabolites in normal humans, chronic renal failure patients, and anephric subjects.
- Author
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Lambert PW, DeOreo PB, Hollis BW, Fu IY, Ginsberg DJ, and Roos BA
- Subjects
- 24,25-Dihydroxyvitamin D 3, Calcifediol, Calcitriol blood, Cholecalciferol metabolism, Dihydroxycholecalciferols blood, Humans, Hydroxycholecalciferols blood, Methods, Cholecalciferol blood, Kidney Failure, Chronic blood, Nephrectomy
- Abstract
Here we report the use of newly developed and established techniques for the determination of plasma levels of a broad spectrum of vitamin D3 metabolites, including vitamin D3 and 25OHD3-lactone, in normal humans, chronic renal failure patients, and anephric subjects. The methodology described consisted of methanol-methylene chloride extraction, Lipidex-5000 chromatography with stepwise gradient elution, normal-phase HPLC with concave gradient elution, and sensitive ligand-binding assays. The results of the study strongly suggest an extrarenal source(s) for 24,25(OH)2D3 and 25,26(OH)2D3 and indicate that both 25OHD3-lactone and 1,25(OH)2D3 may be produced solely in the kidney of the human. Significant reductions or nondetectable plasma levels of vitamin D3 in the renal disease patients may reflect abnormalities in the hepatobiliary-intestinal and/or cutaneous metabolism of vitamin D.
- Published
- 1981
31. Vitamin D in plasma: quantitation by a nonequilibrium ligand binding assay.
- Author
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Hollis BW, Roos BA, and Lambert PW
- Subjects
- 24,25-Dihydroxyvitamin D 3, Animals, Binding, Competitive, Calcifediol, Carrier Proteins metabolism, Cattle, Cholecalciferol metabolism, Chromatography, High Pressure Liquid, Dihydroxycholecalciferols metabolism, Ergocalciferols metabolism, Humans, Hydroxycholecalciferols metabolism, Microchemistry methods, Vitamin D metabolism, Vitamin D toxicity, Vitamin D Deficiency blood, Vitamin D-Binding Protein, Vitamin D blood
- Abstract
The concentration of vitamin D was determined in human and bovine plasma samples under various physiological and nonphysiological conditions using a nonequilibrium ligand binding assay. Prior to ligand binding analysis the vitamin D in the plasma organic extracts was purified using chromatographic procedures involving Lipidex-5000 and high performance liquid chromatography. The use of a nonequilibrium assay system greatly increased the sensitivity of our assay allowing for a minimum volume of the initial plasma sample. The vitamin D levels in plasma responded to increased sun exposure as well as to the intoxication with vitamin D3. Analysis of a plasma sample from a vitamin D-deficient patient revealed that lipid interference was not a factor in this ligand binding assay.
- Published
- 1981
- Full Text
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32. Vitamin D and its metabolites in human and bovine milk.
- Author
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Hollis BW, Roos BA, Draper HH, and Lambert PW
- Subjects
- 24,25-Dihydroxyvitamin D 3, Animals, Calcifediol, Calcitriol, Cattle, Chromatography, High Pressure Liquid, Dihydroxycholecalciferols metabolism, Female, Humans, Hydroxycholecalciferols metabolism, Immunodiffusion, Lactation, Pregnancy, Radioligand Assay, Vitamin D isolation & purification, Milk metabolism, Milk, Human metabolism, Vitamin D metabolism
- Abstract
Human and bovine milk were analyzed for vitamin D, 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, 25,26-dihydroxyvitamin D and 1,25-dihydroxyvitamin D using exhaustive chromatographic purification procedures coupled with ligand binding assays. Human milk contained the following amounts of antirachitic sterols (pg/ml, mean +/- SD, n = 5): 39 +/- 9 vitamin D; 311 +/- 31 25-hydroxyvitamin D; 52 +/- 8 24,25-hydroxyvitamin D; 32 +/- 9 25,26-dihydroxyvitamin D; 5.1 +/- 0.3 1,25-dihydroxyvitamin D. Normal bovine milk contained levels of these sterols comparable to those found in human milk. Increasing the oral dose of vitamin D to the cows was reflected by an increase of the parent vitamin and 25-hydroxyvitamin D in the milk. Vitamin D-binding protein concentration in human milk whey, determined by Ouchterlony immunodiffusion and radioimmunoassay, was 1--2% of the levels observed in the plasma and was dependent on the stage of lactation. Vitamin D and its metabolites were shown initially to be present in the whey portion but with time migrated into the fat portion of milk. The antirachitic sterols detected account for approximately 25 IU/liter and 27 IU/liter of antirachitic activity in human and bovine milk, respectively. In both species 25-hydroxyvitamin D comprised the majority of the antirachitic sterols detected in normal milk.
- Published
- 1981
- Full Text
- View/download PDF
33. Structure and expression of a gene encoding human calcitonin and calcitonin gene related peptide.
- Author
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Nelkin BD, Rosenfeld KI, de Bustros A, Leong SS, Roos BA, and Baylin SB
- Subjects
- Base Sequence, Calcitonin Gene-Related Peptide, Cell Line, DNA analysis, Humans, Nucleic Acid Hybridization, Poly A analysis, RNA, Messenger analysis, Thyroid Neoplasms analysis, Thyroid Neoplasms genetics, Calcitonin genetics, Gene Expression Regulation, Nerve Tissue Proteins genetics
- Abstract
Messenger RNAs for calcitonin (CT) and calcitonin gene related peptide (CGRP) have been detected in a human medullary thyroid carcinoma cell line. DNA sequences of their cloned cDNAs, and genomic restriction mapping, indicate that both mRNAs probably originate from a single gene; the separate mRNAs are derived by alternative processing. The calcitonin gene is expressed in 10 of 10 examined culture lines of human lung cancer; most of these lines express a higher ratio of CGRP to CT specific mRNA than does the medullary thyroid carcinoma cell line.
- Published
- 1984
- Full Text
- View/download PDF
34. Purification of a peptidylglycine alpha-amidating enzyme from transplantable rat medullary thyroid carcinomas.
- Author
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Mehta NM, Gilligan JP, Jones BN, Bertelsen AH, Roos BA, and Birnbaum RS
- Subjects
- Animals, Chromatography, Gel, Chromatography, Ion Exchange, Kinetics, Molecular Weight, Oxidoreductases Acting on CH-NH Group Donors metabolism, Rats, Mixed Function Oxygenases, Multienzyme Complexes, Oxidoreductases Acting on CH-NH Group Donors isolation & purification, Thyroid Neoplasms enzymology
- Abstract
A peptidyl glycine alpha-amidating activity has been isolated from total tissue extracts of rat medullary thyroid carcinoma (MTC). Purification of the activity by ammonium sulfate fractionation, Sephacryl S-300 chromatography, and strong anion-exchange chromatography at pH 6.0 has resolved at least four peaks of activity. The activity associated with peak III has been further purified to apparent homogeneity by strong anion-exchange chromatography at pH 8.0. The purified peak III enzyme has an apparent molecular mass of 75,000 Da as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identity of the 75,000-Da band as the alpha-amidating enzyme has been confirmed by recovery of activity from a nondenaturing polyacrylamide gel. The enzyme is catalytically active as a monomer, exhibits a pH optimum between 5.0 and 5.5, and has a turnover number of 300 min-1 for N-dansyl-Tyr-Val-Gly amidation at pH 5.5. The larger size, more acidic pH optimum, and higher specific activity distinguish the purified peak III rat MTC enzyme from the enzymes isolated from bovine and porcine pituitary or from frog skin.
- Published
- 1988
- Full Text
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35. Evidence for a pro-calcitonin.
- Author
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Roos BA, Okano K, and Deftos LJ
- Subjects
- Animals, Calcitonin immunology, Carbon Radioisotopes, Chromatography, Gel, Goats immunology, Immunologic Techniques, Leucine metabolism, Molecular Weight, Rabbits immunology, Radioimmunoassay, Time Factors, Trout, Ultimobranchial Body metabolism, Calcitonin biosynthesis, Protein Precursors biosynthesis
- Published
- 1974
- Full Text
- View/download PDF
36. Virus infections in infant mice causing persistent impairment of turnover of brain catecholamines.
- Author
-
Lycke E and Roos BE
- Subjects
- Age Factors, Animals, Body Weight, Coxsackievirus Infections metabolism, Dopamine metabolism, Herpes Simplex metabolism, Herpes Simplex mortality, Homovanillic Acid metabolism, Hydroxyindoleacetic Acid metabolism, Mice, Norepinephrine metabolism, Serotonin metabolism, West Nile Fever metabolism, Yellow Fever metabolism, Animals, Newborn metabolism, Brain metabolism, Catecholamines metabolism, Disease Models, Animal, Virus Diseases metabolism
- Abstract
Newborn mice were inoculated with attenuated Coxsackie type B4 virus. Three-to-4-day old mice were infected with yellow fever virus vaccine. A number of mice survived the acute infections. Some of these demonstrated residual neurological symptoms, some showed recovery from symptoms while others survived the infection without revealing symptoms of disease. Determinations of dopamine, noradrenaline, 5-hydroxytryptamine, homovanillic acid and 5-hydroxyindoleacetic acid in the inoculated brains indicated an imparied turnover of neurotransmitters. Subnormal concentrations of catecholamines and homovanillic acid were encountered in the acutely-infected mice as well as among the survivors. Failure to synthesize catecholamines was observed not only in mice demonstrating symptoms of disease or in animals which recovered from their infection but also among a proportion of the mice which never demonstrated neurological symptoms. In contrast, 6-week-old Swiss albino mice infected with West Nile virus showed no effect on the turnover of brain monoamines either in acutely infected mice or in animals which survived the acute infection. Herpes simplex virus infection of 3-week-old mice induced during the acute infection an increased release of neurotransmitters. When these mice were "cured" of the infection by increasing the environmental temperature the elevated turnover of monoamine metabolism was normalized. Two months later there were no differences in concentrations of catecholamines or homovanillic acid between infected animals or uninfected controls. Thus, persistent impairment of brain monoamine metabolism was induced in mice infected when very young. The possible importance of the observations, in particular the findings of an impaired turnover after subclinical infection, is discussed.
- Published
- 1975
- Full Text
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37. Paired-ion reversed-phase high-performance liquid chromatography of human and rat calcitonin.
- Author
-
Lambert PW and Roos BA
- Subjects
- Animals, Calcitonin blood, Chromatography, High Pressure Liquid methods, Humans, Microchemistry, Rats, Calcitonin analysis
- Abstract
Improved methods for isolation, characterization, and quantitation of immunochemically heterogeneous forms of calcitonin (CT) in tissue and plasma must be developed before the biological origins and clinical importance of CT moieties can be elucidated. We are now proposing reversed-phase high-performance liquid chromatography (RP-HPLC) as one possible means of achieving high recovery, high resolution of CT moieties. In this paper we report RP-HPLC analyses of trace amounts of radiolabeled and unlabeled synthetic human and rat CT. We have systematically evaluated our application of RP-HPLC by employing several elution modes, including isocratic and gradient elution, as well as several elution reagents. We determined that high recovery and high resolution were best achieved with alkyl ion-pairing reagents, such as tetrabutylammonium phosphate, pH 7.5, or sodium sulfonyl hexane, pH 3.5. The most sensitive UV detection of trace amounts of CT was achieved with tetrabutylammonium phosphate buffer (TBAP). We recommend for RP-HPLC of CT a C18-bonded silica column and elution with a 20-min linear gradient of methanol-water (20:80 to 80:20, v/v) containing 0.005 M TBAP. Combined with appropriate extraction procedures, such as silica adsorption or immuno-adsorbant chromatography, this paired-ion RP-HPLC method can be an important aid in achieving more accurate and extensive information about CT moieties in biological samples. This method will also allow the rapid, optical detection and quantitation of CT moieties recovered from tissues, and perhaps from plasmas.
- Published
- 1980
- Full Text
- View/download PDF
38. Letter: Potentiation of antidepressant action of clomipramine by tryptophan.
- Author
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Walinder J, Skott A, Nagy A, Carlsson A, and Roos BE
- Subjects
- Clinical Trials as Topic, Clomipramine therapeutic use, Drug Synergism, Drug Therapy, Combination, Humans, Male, Tryptophan therapeutic use, Clomipramine administration & dosage, Depression drug therapy, Dibenzazepines administration & dosage, Tryptophan administration & dosage
- Published
- 1975
- Full Text
- View/download PDF
39. Occurrence of vitamin D sulfate in human milk whey.
- Author
-
Hollis BW, Roos BA, Draper HH, and Lambert PW
- Subjects
- Cholecalciferol analysis, Chromatography, High Pressure Liquid methods, Ergocalciferols analysis, Female, Humans, Pregnancy, Milk, Human analysis, Sulfuric Acid Esters analysis, Sulfuric Acids analysis, Vitamin D analysis
- Abstract
Following reports that vitamin D sulfate is the major source of vitamin D activity in human milk, we investigated the presence of this compound in milk whey using a modification of techniques for the determination of vitamin D metabolites in plasma. Synthetic cholecalciferol sulfate, ergocalciferol sulfate an [3H]cholecalciferol sulfate were prepared by reacting radioactive cholecalciferol or nonradioactive cholecalciferol or ergocalciferol with sulfamic acid in pyridine. The products were purified sequentially by Sephadex LH-20 and high pressure liquid chromatography. The purified products were chromatographically homogeneous, exhibited an ultraviolet absorption spectrum identical to that of standard cholecalciferol, demonstrated a sulfonate ester linkage and upon saponification yielded the parent vitamin. Milk whey was extracted with methanol:methylene chloride (1:2 v/v) using [3H]cholecalciferol sulfate to estimate recovery of the compound. The extract was purified by chromatography on silica cartridges an reverse phase high pressure liquid chromatography and was quantitated by ultraviolet absorption (UV). Although added cholecalciferol sulfate was readily detected in human milk whey samples, no endogenous vitamin D sulfate was found (detection limit 1 ng/ml). The results indicate that vitamin D sulfate is not a major source of vitamin D activity in human milk.
- Published
- 1981
- Full Text
- View/download PDF
40. Influence of changes in brain monoamine metabolism on behaviour of herpes simplex-infected mice.
- Author
-
Lycke E and Roos BE
- Subjects
- Aggression, Animals, Apomorphine pharmacology, Brain drug effects, Brain enzymology, Clonidine pharmacology, Dihydroxyphenylalanine pharmacology, Disease Models, Animal, Disulfides pharmacology, Dopamine beta-Hydroxylase metabolism, Fenclonine pharmacology, Herpes Simplex enzymology, Homovanillic Acid metabolism, Humans, Hydroxyindoleacetic Acid metabolism, Methyltyrosines pharmacology, Mice, Motor Activity, Norepinephrine metabolism, Phenoxybenzamine pharmacology, Pimozide pharmacology, Receptors, Adrenergic drug effects, Tyrosine 3-Monooxygenase metabolism, Vaccinia metabolism, Virus Cultivation, Behavior, Animal, Brain metabolism, Dopamine metabolism, Herpes Simplex metabolism, Serotonin metabolism
- Published
- 1974
- Full Text
- View/download PDF
41. Radioimmunoassay of calcitonin in plasma, normal thyroid, and medullary thyroid carcinoma of the rat.
- Author
-
Roos BA, Deftos LJ, Roberts G, Wilson P, and Bundy L
- Subjects
- Animals, Calcitonin blood, Calcium pharmacology, Edetic Acid pharmacology, Humans, Male, Neoplasms, Experimental metabolism, Parathyroid Glands surgery, Pentagastrin pharmacology, Prostaglandins E pharmacology, Radioimmunoassay, Rats, Thyroidectomy, Calcitonin metabolism, Carcinoma metabolism, Thyroid Gland metabolism, Thyroid Neoplasms metabolism
- Abstract
We have developed a sensitive immunoassay for murine calcitonin which can measure the basal concentration of the hormone in peripheral plasma of rats as well as the calcitonin, extracted from rat thyroid tissue. Human calcitonin was used for tracer, standard, and antibody production. Assay methods were devised to minimize artifacts which have been shown to spuriously influence immunoassay performance. The basal plasma concentration of calcitonin in rats was 6 to 75 pg. per milliliter. Infusions of calcium, pentagastrin, and PGE2 produced a 2- to 7-fold increase in plasma calcitonin. Elevated concentrations of calcitonin were demonstrated in tumor specimens obtained from the second and fourth generations of a transplanted rat medullary thyroid carcinoma. Our results demonstrate that calcitonin circulates in the peripheral plasma of rats in the basal state and that hormone concentrations change during functional tests of secretion. This assay will permit studies of calcitonin secretion in physiological and pathophysiological states in the rat.
- Published
- 1976
42. Deficient calcitonin response to calcium stimulation in postmenopausal osteoporosis?
- Author
-
Taggart HM, Chesnut CH 3rd, Ivey JL, Baylink DJ, Sisom K, Huber MB, and Roos BA
- Subjects
- Aged, Bone and Bones metabolism, Calcitonin deficiency, Calcium metabolism, Female, Humans, Middle Aged, Osteoporosis etiology, Calcitonin pharmacology, Calcium pharmacology, Menopause, Osteoporosis blood
- Abstract
To test whether mobilisation of immunoreactive calcitonin in response to calcium challenge is reduced in postmenopausal osteoporosis, seventeen postmenopausal osteoporotic women with compression fractures and ten normal age-matched women were given intravenous infusions of 3 mg/kg elemental calcium over a 10 min period. Blood samples were obtained 5 min before and at 0, 10, 20, and 60 min after start of infusion for the measurement of serum calcium and plasma immunoreactive calcitonin. Serum calcium increased significantly from baseline in both normal and osteoporotic groups; immunoreactive calcitonin increased significantly in the controls 10 min and 20 min after the start of infusion, but in the women with osteoporosis calcitonin levels did not change significantly at any time. 20 min after the start of infusion the change in immunoreactive calcitonin from baseline was significantly less in osteoporotic women than in the controls. These data are consistent with a decreased immunoreactive calcitonin response to calcium infusion in postmenopausal osteoporotic women, and suggest that calcitonin deficiency may be involved in the development of postmenopausal osteoporosis.
- Published
- 1982
- Full Text
- View/download PDF
43. 25,26-Dihydroxycholecalciferol: a precursor in the renal synthesis of 25-hydroxycholecalciferol-26,23-lactone.
- Author
-
Hollis BW, Roos BA, and Lambert PW
- Subjects
- Animals, Chickens, Chromatography, Gel, Chromatography, High Pressure Liquid, Dihydroxycholecalciferols isolation & purification, Rickets metabolism, Tritium, Calcifediol analogs & derivatives, Dihydroxycholecalciferols metabolism, Hydroxycholecalciferols biosynthesis, Hydroxycholecalciferols metabolism, Kidney metabolism
- Published
- 1980
- Full Text
- View/download PDF
44. Identification of cellular prosomatostatin and nonsomatostatin peptides derived from its amino terminus.
- Author
-
Aron DC, Andrews PC, Dixon JE, and Roos BA
- Subjects
- Amino Acid Sequence, Animals, Cell Line, Chromatography, High Pressure Liquid, Molecular Weight, Radioimmunoassay, Rats, Peptide Fragments analysis, Protein Precursors analysis, Somatostatin analysis, Thyroid Neoplasms analysis
- Abstract
Rat prosomatostatin was isolated from a somatostatin-producing cell line and was partially microsequenced. This indicated the amino terminal structure of cellular prosomatostatin and implied a 92-amino acid sequence for the somatostatin precursor. Based on the structure for cellular prosomatostatin, a peptide was synthesized and used to develop a radioimmunoassay directed toward the amino terminal portion of prosomatostatin. This assay has revealed two peptides containing the amino-terminal portion of prosomatostatin in a somatostatin-secreting CA-77 rat medullary thyroid carcinoma cell line. These two peptides - MW 4000 and 8000 daltons - lack somatostatin immunoreactivity. Thus, processing of prosomatostatin occurs both at the amino and carboxyl regions. These results open the way for elucidation of the structure, function and metabolism of non-somatostatin peptides derived from the amino terminus of prosomatostatin.
- Published
- 1984
- Full Text
- View/download PDF
45. 5-hydroxytryptophan for depression.
- Author
-
Persson T and Roos BE
- Subjects
- Amitriptyline therapeutic use, Dihydroxyphenylalanine therapeutic use, Electroconvulsive Therapy, Humans, Male, Middle Aged, Psychopharmacology, 5-Hydroxytryptophan therapeutic use, Depression drug therapy
- Published
- 1967
- Full Text
- View/download PDF
46. 5-hydroxyindoleacetic and homovanillic acid levels in the cerebrospinal fluid of healthy volunteers and patients with Parkinson's syndrome.
- Author
-
Johansson B and Roos BE
- Subjects
- Adult, Aged, Basal Ganglia metabolism, Brain Stem metabolism, Caudate Nucleus metabolism, Chemistry, Clinical, Dopamine metabolism, Humans, Middle Aged, Norepinephrine metabolism, Serotonin metabolism, Hydroxyindoleacetic Acid cerebrospinal fluid, Parkinson Disease cerebrospinal fluid, Phenylacetates cerebrospinal fluid
- Published
- 1967
- Full Text
- View/download PDF
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