19 results on '"Robert A Oster"'
Search Results
2. Randomized trial of weight loss in primary breast cancer: Impact on body composition, circulating biomarkers and tumor characteristics
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Robert A. Oster, Andrew D. Frugé, Lyse A. Norian, Eddy S. Yang, Helen Krontiras, Wendy Demark-Wahnefried, William E. Grizzle, Justin T. Gibson, Lee W. Jones, Shuko Harada, Maria Azrad, Deborah L. Della Manna, and Laura Q. Rogers
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Counseling ,Oncology ,Cancer Research ,medicine.medical_specialty ,Breast Neoplasms ,Overweight ,law.invention ,03 medical and health sciences ,breast cancer ,0302 clinical medicine ,Breast cancer ,Randomized controlled trial ,Weight loss ,law ,Internal medicine ,Weight Loss ,medicine ,Humans ,Aerobic exercise ,Obesity ,Cancer Therapy and Prevention ,Adverse effect ,Caloric Restriction ,exercise ,business.industry ,Cancer ,clinical trial ,medicine.disease ,Exercise Therapy ,030220 oncology & carcinogenesis ,Body Composition ,Female ,medicine.symptom ,diet ,business ,Ki67 ,Biomarkers - Abstract
Obesity adversely impacts overall and cancer‐specific survival among breast cancer patients. Preclinical studies demonstrate negative energy balance inhibits cancer progression; however, feasibility and effects in patients are unknown. A two‐arm, single‐blinded, randomized controlled weight‐loss trial was undertaken presurgery among 32 overweight/obese, Stage 0–II breast cancer patients. The attention control arm (AC) received basic nutritional counseling and upper‐body progressive resistance training whereas the weight loss intervention (WLI) arm received identical guidance, plus counseling on caloric restriction and aerobic exercise to promote 0.68–0.92 kg/week weight loss. Anthropometrics, body composition, blood and survey data were collected at baseline and presurgery ∼30 days later. Tumor markers (e.g., Ki67) and gene expression were assessed on biopsy and surgical specimens; sera were analyzed for cytokines, growth and metabolic factors. Significant WLI vs. AC differences were seen in baseline‐to‐follow‐up changes in weight (−3.62 vs. −0.52 kg), %body fat (−1.3 vs. 0%), moderate‐to‐vigorous physical activity (+224 vs. +115 min/week), caloric density (−0.3 vs. 0 kcal/g), serum leptin (−12.3 vs. −4.0 ng/dl) and upregulation of tumor PI3Kinase signaling and cell cycle‐apoptosis related genes (CC‐ARG; all p‐values, What's new? Obesity adversely impacts survival among breast cancer patients. Preclinical studies demonstrate negative energy balance inhibits cancer progression; however, effects in patients are unknown. This is the first randomized controlled trial to assess the impact of a pre‐surgical weight loss intervention among early‐stage breast cancer patients. Results show the effects of acute negative energy balance on tumor biology, circulating biomarkers, and quality‐of‐life. Short‐term weight loss interventions are feasible; however, mixed effects on tumor biology suggest unclear benefit to pre‐surgical caloric restriction. Such interventions may be better timed after surgical resection, though cell cycle‐apoptosis and DNA damage‐repair scores support increasing physical activity.
- Published
- 2020
3. Increased troponin I is associated with fatal outcome in acquired thrombotic thrombocytopenic purpura
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Robert A. Oster, Jill Adamski, Jason Brazelton, Marisa B. Marques, Brandi McCleskey, and Jessica Fuller
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medicine.medical_specialty ,Anemia ,Thrombotic thrombocytopenic purpura ,Renal function ,030204 cardiovascular system & hematology ,Gastroenterology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,hemic and lymphatic diseases ,Internal medicine ,Troponin I ,medicine ,Creatinine ,Univariate analysis ,Acquired Thrombotic Thrombocytopenic Purpura ,biology ,business.industry ,Hematology ,General Medicine ,medicine.disease ,Surgery ,chemistry ,biology.protein ,Creatine kinase ,business ,030215 immunology - Abstract
Thrombotic thrombocytopenic purpura (TTP) has >90% mortality without therapeutic plasma exchange (TPE). Despite TPE, approximately 10% of patients still die, presumably from cardiac ischemia. We sought clinical or laboratory parameters associated with death by reviewing the records of all patients hospitalized with acquired TTP in our institution for 10 years, and collect demographics and results for hemoglobin, platelet count, creatinine, lactate dehydrogenase, transaminases, total bilirubin, creatinine kinase (CK), CK-MB, and troponin I. Sixty-eight patients were admitted 88 times, and 11 died. Survivors and non-survivors were similar in terms of sex, ethnicity, thrombocytopenia, and degree of anemia at presentation, while the latter were older, had worse renal function and higher CK, CK-MB, and troponin I (univariate analysis). However, only troponin I remained significant on multivariate analyses. We propose that patients with TTP should be monitored with troponin I to detect significant myocardial ischemia that could predict death despite TPE.
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- 2016
4. Microleakage around Class V Composite Restorations after Ultrasonic Scaling and Sonic Toothbrushing around their Margin
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Suruchi Lamba, John O. Burgess, Ronald E. Goldstein, Robert A. Oster, Nathaniel C. Lawson, and Preston Beck
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Molar ,Materials science ,Enamel paint ,business.industry ,medicine.medical_treatment ,Composite number ,Dentistry ,030206 dentistry ,Apical margin ,Bevel ,stomatognathic diseases ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,visual_art ,visual_art.visual_art_medium ,medicine ,Ultrasonic sensor ,business ,General Dentistry ,Scaling ,Dental restoration ,030217 neurology & neurosurgery - Abstract
Objectives To measure microleakage around class V composite restorations after piezoelectric ultrasonic scaling and sonic toothbrushing. Methods 3 mm × 2 mm × 1.5 mm boxes were prepared on buccal and lingual surfaces of extracted molars centered on the cementum-enamel junction. Half the preparations were beveled (0.5 mm). Preparations were restored with composite and polished. Restorations on one side of the teeth were either traced with an ultrasonic scaler (60 seconds, n = 16) or brushed in a sonic toothbrushing machine (2 hours, n = 16). After thermocycling (10,000 cycles/5–55°C), specimens were immersed in 5 wt% Fuchsine solution (24 hours). Samples were sectioned and evaluated for percentage of dye penetration. Data were analyzed with an exact Wilcoxon rank-sum test and exact Wilcoxon signed-rank test (alpha = 0.05). Results Microleakage was observed at the cementum-composite interface but not the enamel-composite interface. There was not a statistically significant effect of the bevel for ultrasonic scaling or for sonic toothbrushing. Data obtained with and without a bevel were combined and a statistically significant difference in microleakage between the treatment and control sides of the tooth were found for ultrasonic scaling (32.5%±44.9%, n = 16; p = 0.016) but not sonic toothbrushing (2.5% ± 41.2%, n = 16; p = 1.0). Conclusions Piezoelectric ultrasonic scaling increased microleakage at cementum-composite interface and there was no difference in microleakage with the use of a bevel. Clinical Significance Piezoelectric sonic scaling around Class V composite restorations with margins in cementum should be avoided. Beveled margins will not reduce the incidence of microleakge resulting from ultrasonic scaling in Class V restorations. Placing the apical margin of the restoration in enamel should be attempted whenever possible to prevent future microleakage. (J Esthet Restor Dent 29:41–48, 2017)
- Published
- 2016
5. Risk stratification model to detect early pulmonary disease in infants with cystic fibrosis diagnosed by newborn screening
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LaCrecia J. Britton, Hector H. Gutierrez, Staci Thrasher Self, Gabriela R. Oates, Robert A. Oster, Robert Bradley Troxler, Wynton C. Hoover, and William T. Harris
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Pulmonary and Respiratory Medicine ,Newborn screening ,Pediatrics ,medicine.medical_specialty ,business.industry ,Pulmonary disease ,Retrospective cohort study ,medicine.disease ,Cystic fibrosis ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,030225 pediatrics ,Pediatrics, Perinatology and Child Health ,Risk stratification ,medicine ,Respiratory system ,business ,Socioeconomic status - Abstract
SummaryObjective The clinical benefit of newborn screening (NBS) for cystic fibrosis (CF) has been primarily nutritional, with less overt respiratory impact. Identification of risk factors for infant CF lung disease could facilitate targeted interventions to improve pulmonary outcomes. Methods This retrospective study evaluated socioeconomic information, clinical data, and results from routine infant pulmonary function testing (iPFT) of infants diagnosed with CF through NBS (N = 43) at a single CF center over a 4-year period (2008–2012). A five-item composite clinical score was developed and combined with socioeconomic indicators to facilitate identification of CF infants at increased risk of early-onset respiratory impairment. Results Paternal education was positively associated with lung function (P = 0.02). Clinical score
- Published
- 2016
6. Economic hardship of minority and non-minority cancer survivors 1 year after diagnosis: Another long-term effect of cancer?
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Michelle Y. Martin, Maria Pisu, Kimlin Tam Ashing, Mph Mona N. Fouad Md, Robert A. Oster, Kelly M. Kenzik, and Patricia Drentea
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Gerontology ,Cancer Research ,business.industry ,Colorectal cancer ,Ethnic group ,Cancer ,medicine.disease ,Economic hardship ,Quality of life (healthcare) ,Oncology ,Survivorship curve ,Medicine ,Term effect ,business ,Lung cancer ,human activities ,health care economics and organizations - Abstract
Background Current literature suggests that racial/ethnic minority survivors may be more likely than whites to experience economic hardship after a cancer diagnosis; however, little is known about such hardship.
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- 2015
7. Assessing Statistical Competencies in Clinical and Translational Science Education: One Size Does Not Fit All
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M.P.H. Bradley H. Pollock Ph.D., Elizabeth J. Kopras, Leah J. Welty, Borko Jovanovic, Christopher J. Lindsell, Madhu Mazumdar, M.P.H. Felicity T. Enders Ph.D., Sally W. Thurston, Mohammad H. Rahbar, Andrew J. Cucchiara, Rickey E. Carter, and Robert A. Oster
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Research design ,Medical education ,business.industry ,General Neuroscience ,Principal (computer security) ,General Medicine ,General Biochemistry, Genetics and Molecular Biology ,Learning potential ,Coursework ,Medicine ,General Pharmacology, Toxicology and Pharmaceutics ,Biostatistics ,Translational science ,business ,Baseline (configuration management) ,Medical literature - Abstract
Introduction Statistics is an essential training component for a career in clinical and translational science (CTS). Given the increasing complexity of statistics, learners may have difficulty selecting appropriate courses. Our question was: what depth of statistical knowledge do different CTS learners require? Methods For three types of CTS learners (principal investigator, co-investigator, informed reader of the literature), each with different backgrounds in research (no previous research experience, reader of the research literature, previous research experience), 18 experts in biostatistics, epidemiology, and research design proposed levels for 21 statistical competencies. Results Statistical competencies were categorized as fundamental, intermediate, or specialized. CTS learners who intend to become independent principal investigators require more specialized training, while those intending to become informed consumers of the medical literature require more fundamental education. For most competencies, less training was proposed for those with more research background. Discussion When selecting statistical coursework, the learner's research background and career goal should guide the decision. Some statistical competencies are considered to be more important than others. Baseline knowledge assessments may help learners identify appropriate coursework. Conclusion Rather than one size fits all, tailoring education to baseline knowledge, learner background, and future goals increases learning potential while minimizing classroom time.
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- 2014
8. Plasma TGF-β1 in pediatric cystic fibrosis: Potential biomarker of lung disease and response to therapy
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Michael R. Knowles, Marianne S. Muhlebach, William T. Harris, John P. Clancy, Robert A. Oster, and Terry L. Noah
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Pulmonary and Respiratory Medicine ,Pancreatic disease ,medicine.diagnostic_test ,Pseudomonas aeruginosa ,business.industry ,Respiratory disease ,medicine.disease ,medicine.disease_cause ,Cystic fibrosis ,Bronchoalveolar lavage ,Pediatrics, Perinatology and Child Health ,Immunology ,medicine ,Young adult ,Prospective cohort study ,business ,Transforming growth factor - Abstract
Introduction Transforming growth factor beta-1 (TGF-β1) is an important genetic modifier of lung disease severity in cystic fibrosis (CF), yet the mechanism behind this disease association remains unknown. Initial steps in the investigation of the relationship between TGF-β1 and CF lung disease include determining the most appropriate available biospecimen for TGF-β1 protein measurement.
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- 2011
9. Dietary Calcium Intake Is Associated With Less Gain in Intra-Abdominal Adipose Tissue Over 1 Year
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Nikki C. Bush, Suzanne S. Choquette, Barbara A. Gower, Betty E. Darnell, Robert A. Oster, Gary R. Hunter, and Jessica A. Alvarez
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Adult ,medicine.medical_specialty ,Intra-Abdominal Fat ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,chemistry.chemical_element ,Adipose tissue ,Calcium ,Weight Gain ,Diet Records ,Article ,Young Adult ,Absorptiometry, Photon ,Endocrinology ,Weight loss ,Internal medicine ,medicine ,Body Fat Distribution ,Humans ,Longitudinal Studies ,Nutrition and Dietetics ,business.industry ,Confounding ,medicine.disease ,Subcutaneous Fat, Abdominal ,Calcium, Dietary ,Menopause ,Adipose Tissue ,Premenopause ,chemistry ,Female ,medicine.symptom ,Energy Intake ,business ,Weight gain - Abstract
Calcium intake is reported to enhance weight loss with a preferential loss in trunk fat. Discrepant findings exist as to the effects of calcium intake on longitudinal changes in total fat mass and central fat deposition. Therefore, the purpose of this study was to determine associations between dietary calcium intake and 1-year change in body composition and fat distribution, specifically intra-abdominal adipose tissue (IAAT). A total of 119 healthy, premenopausal women were evaluated at baseline and 1 year later. Average dietary calcium was determined via 4-day food records. Total fat was determined by dual-energy X-ray absorptiometry (DXA) and subcutaneous abdominal adipose tissue (SAAT) and IAAT by computed tomography. Over the study period, participants' reported daily calcium and energy intakes were 610.0 ± 229.9 mg and 1,623.1 ± 348.5 kcal, respectively. The mean change in weight, total fat, IAAT, and SAAT was 4.9 ± 4.4 kg, 5.3 ± 4.0 kg, 7.7 ± 19.5 cm(2), and 49.3 ± 81.1 cm(2), respectively. Average calcium intake was significantly, inversely associated with 1-year change in IAAT (standardized β: -0.23, P0.05) after adjusting for confounding variables. For every 100 mg/day of calcium consumed, gain in IAAT was reduced by 2.7 cm(2). No significant associations were observed for average calcium intake with change in weight, total fat, or SAAT. In conclusion, dietary calcium intake was significantly associated with less gain in IAAT over 1 year in premenopausal women. Further investigation is needed to verify these findings and determine the calcium intake needed to exert beneficial effects on fat distribution.
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- 2010
10. A high-protein diet or combination exercise training to improve metabolic health in individuals with long-standing spinal cord injury: a pilot randomized study
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C. Scott Bickel, Ceren Yarar-Fisher, Robert A. Oster, Marcas M. Bamman, Keith F. L. Polston, Jia Li, Mualla Eraslan, Amie McLain, and Samuel T. Windham
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Central Nervous System ,Blood Glucose ,Male ,Physiology ,medicine.medical_treatment ,Deltoid curve ,Pilot Projects ,High-protein diet ,030204 cardiovascular system & hematology ,medicine.disease_cause ,Signalling Pathways ,law.invention ,0302 clinical medicine ,Randomized controlled trial ,law ,insulin resistance ,Homeostasis ,Spinal cord injury ,Original Research ,exercise ,Endurance and Performance ,Middle Aged ,Combined Modality Therapy ,Exercise Therapy ,Body Composition ,Diet, High-Protein ,Female ,Adult ,medicine.medical_specialty ,Immunology ,high‐protein diet ,030209 endocrinology & metabolism ,Neurological Conditions, Disorders and Treatments ,03 medical and health sciences ,Insulin resistance ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Muscle, Skeletal ,Spinal Cord Injuries ,business.industry ,Insulin ,Glucose transporter ,medicine.disease ,spinal cord injury ,Regimen ,Endocrinology ,Electrical stimulation ,Patient Compliance ,business - Abstract
We compared the effects of an 8‐week iso‐caloric high‐protein (HP) diet versus a combined exercise regimen (Comb‐Ex) in individuals with long‐standing spinal cord injury (SCI). Effects on metabolic profiles, markers of inflammation, and signaling proteins associated with glucose transporter 4 (GLUT‐4) translocation in muscles were evaluated. Eleven participants with SCI completed the study (HP diet: n = 5; Comb‐Ex: n = 6; 46 ± 8 years; C5‐T12 levels; American Spinal Injury Association Impairment Scale A or B). The Comb‐Ex regimen included upper body resistance training (RT) and neuromuscular electrical stimulation‐induced‐RT for paralytic quadriceps muscles, interspersed with high‐intensity (80–90% VO2 peak) arm cranking exercises 3 days/week. The HP diet included ~30% total energy as protein (carbohydrate to protein ratio
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- 2018
11. Associations of Free Fatty Acids With Insulin Secretion and Action Among African-American and European-American Girls and Women
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Robert A. Oster, Marian A. Brown, Barbara A. Gower, Laura Lee Goree, and Betty E. Darnell
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Aging ,Time Factors ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Medicine (miscellaneous) ,Fatty Acids, Nonesterified ,Absorptiometry, Photon ,Endocrinology ,Risk Factors ,Insulin ,Child ,Adiposity ,education.field_of_study ,Glucose tolerance test ,Nutrition and Dietetics ,medicine.diagnostic_test ,Age Factors ,Middle Aged ,Female ,lipids (amino acids, peptides, and proteins) ,hormones, hormone substitutes, and hormone antagonists ,Nadir (topography) ,Adult ,medicine.medical_specialty ,Adolescent ,Population ,Blood sugar ,Risk Assessment ,Article ,White People ,Young Adult ,Insulin resistance ,Internal medicine ,medicine ,Humans ,Obesity ,education ,Aged ,business.industry ,Glucose Tolerance Test ,medicine.disease ,United States ,Black or African American ,body regions ,Basal (medicine) ,Linear Models ,Insulin Resistance ,Tomography, X-Ray Computed ,business - Abstract
Ethnic differences in insulin secretion and action between African Americans (AAs) and European Americans (EAs) may influence mobilization of free fatty acids (FFAs). We tested the hypotheses that FFA concentrations would be associated with measures of insulin secretion and action before and during a glucose challenge test. Subjects were 48 prepubertal girls, 60 premenopausal women, and 46 postmenopausal women. Fasting insulin (insulin(0)), the acute insulin response to glucose (AIR(g)), the insulin sensitivity index (S(I)), basal and nadir FFA (FFA(0), FFA(nadir)), and nadir time (TIME(nadir)) were determined during an intravenous glucose tolerance test (IVGTT). Stepwise multiple linear regression (MLR) analysis was conducted to identify associations of FFA(0), FFA(nadir), and TIME(nadir) with ethnicity, age group, insulin measures, indexes of body composition from dual-energy X-ray absorptiometry, and measures of fat distribution from computed tomography scan. In this population, insulin(0) and AIR(g) were higher among AAs vs. EAs, whereas S(I) was lower, independent of age group. MLR analyses indicated that FFA(0) was best predicted by lean tissue mass (LTM), leg fat mass, ethnicity (lower in AAs), S(I), and insulin(0). FFA(nadir) was best predicted by FFA(0), age group, and intra-abdominal adipose tissue (IAAT). TIME(nadir) was best predicted by leg fat mass, AIR(g), and S(I). In conclusion, indexes of insulin secretion and action were associated with FFA dynamics in healthy girls and women. Lower FFA(0) among AAs was independent of insulin(0) and S(I). Whether lower FFA(0) is associated with substrate oxidation or risk for obesity remains to be determined.
- Published
- 2010
12. Transforming growth factor-β1in bronchoalveolar lavage fluid from children with cystic fibrosis
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Robert A. Oster, Terry L. Noah, Michael R. Knowles, Marianne S. Muhlebach, and William T. Harris
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Male ,Pulmonary and Respiratory Medicine ,Pancreatic disease ,Cystic Fibrosis ,Neutrophils ,Inflammation ,Disease ,Severity of Illness Index ,Cystic fibrosis ,Pulmonary function testing ,Transforming Growth Factor beta1 ,medicine ,Humans ,Prospective Studies ,Child ,medicine.diagnostic_test ,business.industry ,Respiratory disease ,respiratory system ,medicine.disease ,Respiratory Function Tests ,respiratory tract diseases ,Cross-Sectional Studies ,Bronchoalveolar lavage ,El Niño ,Case-Control Studies ,Pediatrics, Perinatology and Child Health ,Immunology ,Disease Progression ,Airway Remodeling ,Female ,medicine.symptom ,business ,Bronchoalveolar Lavage Fluid ,Biomarkers - Abstract
Rationale Transforming factor β1 (TGF-β1) genetic polymorphisms have been identified as a modifier of cystic fibrosis (CF) lung disease severity. However, few data link TGF-β1 protein levels and clinical markers of CF lung disease severity. Objectives To determine the association between protein levels of TGF-β1 in pediatric CF bronchoalveolar lavage fluid (BALF) and clinical parameters of CF lung disease severity. Methods Total TGF-β1 was measured in BALF from 30 pediatric CF patients and 12 non-CF disease controls undergoing clinically indicated flexible bronchoscopy, and compared to four indicators of clinical disease: infection, inflammation, pulmonary function, and recent/recurrent hospitalization. Results TGF-β1 was elevated in CF BALF compared to non-CF controls (135 ± 15 pg/ml vs. 57 ± 10 pg/ml, P
- Published
- 2009
13. Predictors of response and relapse in a cohort of adults with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: a single-institution experience
- Author
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Robert A. Oster, Marisa B. Marques, Shu T. Huang, and Hande H. Tuncer
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Adult ,Male ,Hemolytic anemia ,medicine.medical_specialty ,Immunology ,Thrombotic thrombocytopenic purpura ,Severity of Illness Index ,Cohort Studies ,Sex Factors ,Predictive Value of Tests ,Recurrence ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Coagulopathy ,Humans ,Immunology and Allergy ,Obesity ,Retrospective Studies ,L-Lactate Dehydrogenase ,Plasma Exchange ,Purpura, Thrombotic Thrombocytopenic ,Vascular disease ,business.industry ,Anemia ,Hematology ,Microangiopathic hemolytic anemia ,Middle Aged ,Prognosis ,medicine.disease ,Surgery ,Treatment Outcome ,Hemolytic-Uremic Syndrome ,Cohort ,Population study ,Female ,business ,Kidney disease - Abstract
BACKGROUND: Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is a diagnosis of exclusion when a patient presents with the sine qua non findings of thrombocytopenia and microangiopathic hemolytic anemia without an identifiable cause. Although most patients respond to therapeutic plasma exchange (TPE), a significant number of patients relapse. The aim was to determine if clinical, laboratory, and/or treatment features could predict response and/or relapse. STUDY DESIGN AND METHODS: This study was a retrospective review of adults with TTP-HUS treated with TPE at our institution from January 1996 to February 2004. RESULTS: The study population consisted of 90 patients (69% female) with mean age of 45 years and mostly obese (65%). The majority of cases were considered idiopathic. Ten patients died (11%) from the disease before achieving a response, whereas 79 percent were considered responders. Obesity and severe anemia at presentation were predictors of response to TPE (p = 0.0126 and p = 0.0071, respectively). Among the responders, 28 percent relapsed in a median of 14 months. Male sex, severe thrombocytopenia (mean ± SD, 13 × 109 ± 8 × 109/L), and higher lactate dehydrogenase pre-/posttreatment ratio were associated with relapse (p values of 0.0141, 0.0199, and 0.0407, respectively). ADAMTS-13 values were not obtained on enough number of patients to provide important data. CONCLUSION: Although patient and laboratory characteristics associated with response and relapse were identified, there was significant overlap between patient groups. Thus, our findings offer preliminary evidence and do not yet justify short- or long-term changes in the management of patients with TTP-HUS.
- Published
- 2007
14. Ability of the Actiwatch Accelerometer to Predict Free-Living Energy Expenditure in Young Children
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David A. Fields, Barbara A. Gower, Frank A. Franklin, Mardya López-Alarcón, Robert A. Oster, Jaime Merrifield, Richard M. Shewchuk, and Tena Hilario-Hailey
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Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Doubly labeled water ,Motor Activity ,Body weight ,White People ,Fat mass ,Endocrinology ,Animal science ,Internal medicine ,Linear regression ,Humans ,Medicine ,Child ,Monitoring, Physiologic ,business.industry ,Percentage body fat ,Public Health, Environmental and Occupational Health ,Black or African American ,Adipose Tissue ,Energy expenditure ,Child, Preschool ,Body Composition ,Linear Models ,Lean body mass ,Female ,Energy Metabolism ,business ,Food Science ,Field conditions - Abstract
Objective: To determine whether activity counts obtained with the Actiwatch monitor are associated with total expenditure and body composition in young children. Research Methods and Procedures: Actiwatch activity monitors were tested in 29 children 4 to 6 years old under field conditions over eight days. Total energy expenditure (TEE) was assessed with the doubly labeled water (DLW) technique. Correlation analyses were used to identify variables related to energy expenditure and percentage body fat. Multiple linear regression analyses were used to examine the variance in TEE and percentage body fat explained by activity counts after adjusting for relevant covariates. Results: Both average total daily activity counts (658, 816 ± 201, 657) and the pattern of activity were highly variable among subjects. TEE was significantly related to lean body mass (r = 0.45) and age (r = 0.48; p < 0.05 for both). Activity counts alone were not associated with TEE. In multiple linear regression analyses, TEE was independently associated with only lean body mass. Percentage fat mass was independently associated with body weight, being a girl, and being white, but not with average total activity counts. Discussion: Activity counts obtained with the Actiwatch under free-living conditions do not reflect TEE in 4- to 6-year-old children and are not correlated with percentage fat mass. Therefore, average total activity counts obtained with the Actiwatch may be of limited value in identifying children at risk for becoming obese.
- Published
- 2004
15. The effect of folic acid and folinic acid supplements on purine metabolism in methotrexate-treated rheumatoid arthritis
- Author
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Sarah L. Morgan, Joseph E. Baggott, Jeannette Y. Lee, Robert A. Oster, and Graciela S. Alarcón
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musculoskeletal diseases ,Vitamin ,medicine.drug_class ,business.industry ,Immunology ,AICA ribonucleotide ,Pharmacology ,Adenosine ,Antimetabolite ,Folinic acid ,chemistry.chemical_compound ,Rheumatology ,chemistry ,Antifolate ,medicine ,Immunology and Allergy ,Pharmacology (medical) ,Methotrexate ,skin and connective tissue diseases ,business ,Purine metabolism ,medicine.drug - Abstract
Objective To determine if folinic acid supplementation during methotrexate (MTX) therapy for rheumatoid arthritis (RA) reduces both urinary 5-aminoimidazole-4-carboxamide (AICA) and urinary adenosine excretion more than does folic acid supplementation. AICA and adenosine are markers for MTX interference with purine metabolism. Methods Forty patients with RA who received MTX for 6 weeks were randomized to receive either daily folic acid or folinic acid supplements during an additional week of MTX therapy. Colorimetric and radioimmunocompetition assays were used to measure 24-hour urinary AICA and adenosine excretion levels, respectively. Results At the end of 6 weeks, 24-hour urinary levels of AICA, but not adenosine, were elevated as compared with baseline levels (i.e., prior to MTX therapy). Folinic acid, but not folic acid, supplementation normalized urinary AICA levels during MTX therapy. Relatively high urinary levels of AICA were correlated with reduced disease activity. No similar correlations were seen with urinary adenosine levels. Conclusion The blockade of purine nucleotide biosynthesis by MTX at the AICA ribonucleotide transformylase–catalyzed step may be related to the efficacy of MTX, and this blockade is effectively relieved by folinic acid, but not by folic acid, supplementation.
- Published
- 2004
16. ?-Agonist-induced alterations in organ weights and protein content: Comparison of racemic clenbuterol and its enantiomers
- Author
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Sidney Pitts, Brian A. Parks, Lawrence E. Wineski, Douglas F. Paulsen, Imad K. Abukhalaf, David E. Potter, Robert A. Oster, Hassan Y. Aboul-Enein, and Daniel A. von Deutsch
- Subjects
Pharmacology ,Agonist ,medicine.medical_specialty ,Anabolism ,medicine.drug_class ,Chemistry ,Organic Chemistry ,Skeletal muscle ,Partial agonist ,Catalysis ,Analytical Chemistry ,Muscle hypertrophy ,Endocrinology ,medicine.anatomical_structure ,Biochemistry ,Clenbuterol ,Internal medicine ,Drug Discovery ,medicine ,Racemic mixture ,Enantiomer ,Spectroscopy ,medicine.drug - Abstract
Clenbuterol is a relatively selective beta2-adrenergic partial agonist that has bronchodilator activity. This drug has been investigated as a potential countermeasure to microgravity- or disuse-induced skeletal muscle atrophy because of presumed anabolic effects. The purpose of this study was to: 1) analyze the anabolic effect of clenbuterol's (-)-R and (+)-S enantiomers (0.2 mg/kg) on muscles (cardiac and skeletal) and other organs; and 2) compare responses of enantiomers to the racemate (0.4 mg/kg and 1.0 mg/kg). Male Sprague Dawley rats were treated with: a) racemic clenbuterol (rac-clenbuterol, 0.4 or 1.0 mg/kg); b) enantiomers [clenbuterol (-)-R or (+)-S]; or c) vehicle (1.0 mL/kg buffered saline). Anabolic activity was determined by measuring tissue mass and protein content. HPLC teicoplanin chiral stationary phase was used to directly resolve racemic clenbuterol to its individual enantiomers. In skeletal muscle, both enantiomers had equal anabolic activity, and the effects were muscle- and anatomic region-specific in magnitude. Although the enantiomers did not affect the ventricular mass to body weight ratio, clenbuterol (+)-S induced a small but significant increase in ventricular mass. Both clenbuterol enantiomers produced significant increases in skeletal muscle mass, while being less active in producing cardiac ventricular muscle hypertrophy than the racemic mixture.
- Published
- 2000
17. Meta‐analysis of cancer incidence in folic acid supplementation trials
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Tsunenobu Tamura, Joseph E. Baggott, and Robert A. Oster
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medicine.medical_specialty ,Cancer incidence ,business.industry ,Internal medicine ,Meta-analysis ,Genetics ,medicine ,business ,Molecular Biology ,Biochemistry ,Gastroenterology ,Folic acid supplementation ,Biotechnology - Published
- 2010
18. The end of the beginning: A commentary on ‘Evaluation metrics for biostatistical and epidemiological collaborations’: A rejoinder
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Rafia Bhore, Leah J. Welty, Deborah J. del Junco, Robert A. Oster, Christopher J. Lindsell, Knut M. Wittkowski, Yi-Ju Li, Dave Demets, and Doris M. Rubio
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Statistics and Probability ,medicine.medical_specialty ,Epidemiology ,medicine ,Sociology ,Data science - Published
- 2011
19. Correction: Evaluation metrics for biostatistical and epidemiological collaborations
- Author
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Robert A. Oster, Leah J. Welty, Christopher J. Lindsell, Doris M. Rubio, Yi-Ju Li, Knut M. Wittkowski, Deborah J. del Junco, and Rafia Bhore
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Statistics and Probability ,medicine.medical_specialty ,Epidemiology ,Computer science ,medicine ,Data mining ,computer.software_genre ,Data science ,computer - Published
- 2012
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