142 results on '"Parvin, C. A."'
Search Results
102. Effect of streptozotocin-induced diabetes on NGF, P75NTR and TrkA content of prevertebral and paravertebral rat sympathetic ganglia
- Author
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Schmidt, R. E., Dorsey, D. A., Roth, K. A., Parvin, C. A., Hounsom, L., and Tomlinson, D. R.
- Published
- 2000
- Full Text
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103. Loci influencing development of Th responses. Identification from in vitro analysis
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Guler, M. L., Gorham, J. D., Dietrich, W. F., Steen, R. G., Parvin, C., Fenoglio, D., Grupe, A., Peltz, G., and Murphy, K. M.
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- 1999
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104. MAKING THE MOST OF YOUR OFFICE
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PARVIN, C.
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Offices -- Planning ,Business ,Business, general - Published
- 1980
105. Vacuolar neuritic dystrophy in aged mouse superior cervical sympathetic ganglia is strain-specific
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Schmidt, R. E., Dorsey, D. A., Beaudet, L. N., Plurad, S. B., Parvin, C. A., and Bruch, L. A.
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- 1998
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106. Hyperleptinaemia of end-stage renal disease is corrected by renal transplantation.
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Landt, M, Brennan, D C, Parvin, C A, Flavin, K S, Dagogo-Jack, S, and Coyne, D W
- Abstract
Previous studies have reported that patients with end-stage renal disease (ESRD) have elevated plasma leptin concentrations, but the cause and significance of the elevations are unknown. We studied leptin concentrations in 29 adults undergoing renal transplantation, to determine if restoration of renal function reduced leptin concentrations in ESRD.
- Published
- 1998
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107. Patterns and Potential Value of Cardiac Troponin I Elevations After Pediatric Cardiac Operations
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Hirsch, R., Dent, C. L., Wood, M. K., Huddleston, C. B., Mendeloff, E. N., Balzer, D. T., Landt, Y., Parvin, C. A., Landt, M., and Ladenson, J. H.
- Published
- 1998
- Full Text
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108. Combining laboratory data sets from multiple institutions using the logical observation identifier names and codes (LOINC)
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Baorto, D. M., Cimino, J. J., Parvin, C. A., and Kahn, M. G.
- Published
- 1998
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109. 1035-222 Local velocity estimation analysis during bipolar single site and linear triple site rapid pacing in canine models: Implications for antitachycardia pacing
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Ryu, Kyungmoo, Ghanem, Raja N, Khrestian, Celeen M, Sahadevan, Jayakumar, Dorostkar, Parvin C, Goldstein, Robert N, and Waldo, Albert L
- Published
- 2004
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110. Using Logical Observation Identifier Names and Codes (LOINC) to Exchange Laboratory Data among Three Academic Hospitals
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Baorto, D. M., James Cimino, Parvin, C. A., and Kahn, M. G.
111. Semi-automated direct colorimetric measurement of creatine kinase isoenzyme MB activity after extraction from serum by use of a CK-MB-specific monoclonal antibody.
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Landt, Y, primary, Vaidya, H C, primary, Porter, S E, primary, Whalen, K, primary, McClellan, A, primary, Amyx, C, primary, Parvin, C A, primary, Kessler, G, primary, Nahm, M H, primary, and Dietzler, D N, primary
- Published
- 1988
- Full Text
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112. A direct comparison of two slope-estimation techniques used in method-comparison studies.
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Parvin, C A, primary
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- 1984
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113. Enhanced glycemic responsiveness to epinephrine in insulin-dependent diabetes mellitus is the result of the inability to secrete insulin. Augmented insulin secretion normally limits the glycemic, but not the lipolytic or ketogenic, response to epinephrine in humans.
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Berk, M A, primary, Clutter, W E, additional, Skor, D, additional, Shah, S D, additional, Gingerich, R P, additional, Parvin, C A, additional, and Cryer, P E, additional
- Published
- 1985
- Full Text
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114. CARDIAC SURGERY OUTCOMES IN HETEROTAXY SYNDROME: 25 YEARS EXPERIENCE FROM A MULTICENTER CONSORTIUM
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Lazaros K. Kochilas, Parvin C. Dorostkar, and Shanthi Sivanandam
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medicine.medical_specialty ,Asplenia ,business.industry ,medicine.disease ,Cardiac surgery ,Heterotaxy Syndrome ,Internal medicine ,Cardiology ,medicine ,cardiovascular system ,Polysplenia ,business ,Cardiology and Cardiovascular Medicine ,Heterotaxy - Abstract
Heterotaxy syndromes of asplenia and polysplenia encompass a wide spectrum of complex cardiovascular abnormalities associated with left-right asymmetry. The combination of structural and electrical cardiac abnormalities along with extracardiac co-morbidity makes cardiac surgery in heterotaxy
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115. 1035-222 Local velocity estimation analysis during bipolar single site and linear triple site rapid pacing in canine models: Implications for antitachycardia pacing
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Albert L. Waldo, Jayakumar Sahadevan, Kyungmoo Ryu, Raja N. Ghanem, Celeen M. Khrestian, Parvin C. Dorostkar, and Robert N. Goldstein
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medicine.medical_specialty ,business.industry ,Velocity estimation ,Single site ,Internal medicine ,Antitachycardia Pacing ,Cardiology ,Medicine ,business ,Cardiology and Cardiovascular Medicine ,Rapid pacing - Full Text
- View/download PDF
116. Reply.
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Parvin, C. A., Kaplan, L. A., Chapman, J. F., McManamon, T. G., and Gronowski, A. M.
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GESTATIONAL age ,FETAL diseases ,LETTERS to the editor - Abstract
Presents a letter in response to a letter about the comprehensive research on the importance of gestational age in the risk factors of fetal lung maturity.
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- 2005
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117. Erythropoietin Therapy in Patients Undergoing Cardiac Operations
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Goodnough, L. T., Despotis, G. J., and Parvin, C. A.
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- 1997
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118. Hypoxia reduces expression and function of system A amino acid transporters in cultured term human trophoblasts.
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Nelson DM, Smith SD, Furesz TC, Sadovsky Y, Ganapathy V, Parvin CA, and Smith CH
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- Cells, Cultured, Female, Fetal Growth Retardation physiopathology, Fetal Hypoxia physiopathology, Humans, Hypoxia metabolism, Hypoxia physiopathology, Placenta Diseases physiopathology, Pregnancy, Amino Acid Transport System A metabolism, Down-Regulation physiology, Fetal Growth Retardation metabolism, Fetal Hypoxia metabolism, Placenta Diseases metabolism, Trophoblasts metabolism
- Abstract
We tested the hypothesis that hypoxia diminishes the expression and transport of neutral amino acids by system A in full-term human trophoblasts. Cytotrophoblasts from normal human placentas were cultured in standard conditions of 20% O(2) or in 1% and 3% O(2) for 24 h before assay. Neutral amino acid transport for systems A, ASC, and L was assayed at 24 and 72 h by the cluster-tray technique. Hypoxia during the initial 24 h of culture reduced system A transport by 82% in 1% O(2) and by 37% in 3% O(2) (P < 0.01) compared with standard conditions. Hypoxia during the latter 24 h of the 72 h in culture reduced system A transport by 55% in 1% O(2) and by 20% in 3% O(2) (P < 0.05) compared with standard conditions at 72 h. Hypoxia (1% O(2)) also reduced total amino acid transport by 40% in the more differentiated syncytiotrophoblasts present at 72 h. Northern analysis of trophoblasts in standard conditions showed that subtypes of human amino acid transporter A (hATA1 and hATA2) were each expressed in cytotrophoblasts and syncytiotrophoblasts. Hypoxia decreased expression of hATA1 and hATA2 in both trophoblast phenotypes. We conclude that hypoxia downregulates system A transporter expression and activity in cultured human trophoblasts.
- Published
- 2003
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119. Inhibition of sorbitol dehydrogenase exacerbates autonomic neuropathy in rats with streptozotocin-induced diabetes.
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Schmidt RE, Dorsey DA, Beaudet LN, Plurad SB, Parvin CA, Yarasheski KE, Smith SR, Lang HJ, Williamson JR, and Ido Y
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- Animals, Anti-Bacterial Agents, Diabetes Mellitus, Experimental pathology, Diabetic Neuropathies pathology, Enzyme Inhibitors pharmacology, Ganglia, Sympathetic enzymology, Ganglia, Sympathetic pathology, Ganglia, Sympathetic ultrastructure, L-Iditol 2-Dehydrogenase metabolism, Male, Pyrimidines pharmacology, Rats, Rats, Sprague-Dawley, Sciatic Nerve enzymology, Sciatic Nerve pathology, Sciatic Nerve ultrastructure, Streptozocin, Diabetes Mellitus, Experimental enzymology, Diabetic Neuropathies enzymology, L-Iditol 2-Dehydrogenase antagonists & inhibitors
- Abstract
We have developed an animal model of diabetic autonomic neuropathy that is characterized by neuroaxonal dystrophy (NAD) involving ileal mesenteric nerves and prevertebral sympathetic superior mesenteric ganglia (SMG) in chronic streptozotocin (STZ)-diabetic rats. Studies with the sorbitol dehydrogenase inhibitor SDI-158, which interrupts the conversion of sorbitol to fructose (and reactions dependent on the second step of the sorbitol pathway), have shown a dramatically increased frequency of NAD in ileal mesenteric nerves and SMG of SDI-treated versus untreated diabetics. Although lesions developed prematurely and in greater numbers in SDI-treated diabetics, their distinctive ultrastructural appearance was identical to that previously reported in long-term untreated diabetics. An SDI effect was first demonstrated in the SMG of rats that were diabetic for as little as 5 wk and was maintained for at least 7.5 months. As in untreated diabetic rats, rats treated with SDI i) showed involvement of lengthy ileal, but not shorter, jejunal mesenteric nerves; ii) demonstrated NAD in paravascular mesenteric nerves distributed to myenteric ganglia while sparing adjacent perivascular axons ramifying within the vascular adventitia; and, iii) failed to develop NAD in the superior cervical ganglia (SCG). After only 2 months of SDI-treatment, tyrosine hydroxylase immunolocalization demonstrated marked dilatation of postganglionic noradrenergic axons in paravascular ileal mesenteric nerves and within the gut wall versus those innervating extramural mesenteric vasculature. The effect of SDI on diabetic NAD in SMG was completely prevented by concomitant administration of the aldose reductase inhibitor Sorbinil. Treatment of diabetic rats with Sorbinil also prevented NAD in diabetic rats not treated with SDI. These findings indicate that sorbitol pathway-linked metabolic imbalances play a critical role in the development of NAD in this model of diabetic sympathetic autonomic neuropathy.
- Published
- 2001
- Full Text
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120. Falsely increased i-STAT chloride results for blood samples with increased urea.
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Pinckard JK, Zahn J, Ashby L, Parvin CA, and Scott MG
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- False Positive Reactions, Humans, Kidney Diseases blood, Kidney Diseases surgery, Point-of-Care Systems, Reagent Kits, Diagnostic, Chlorides blood, Urea blood
- Published
- 2001
121. Evaluation of the TAS analyzer and the low-range heparin management test in patients undergoing extracorporeal membrane oxygenation.
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Ambrose TM, Parvin CA, Mendeloff E, and Luchtman-Jones L
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- Adolescent, Adult, Child, Child, Preschool, Extracorporeal Membrane Oxygenation, Humans, Infant, Infant, Newborn, Reference Standards, Anticoagulants analysis, Blood Coagulation Tests methods, Heparin analysis, Point-of-Care Systems
- Abstract
Background: The new Low-Range Heparin Management Test (LHMT), a method for point-of-care testing (POCT) of heparinization, has been designed to function at the low to moderate heparin concentrations typically found in patients undergoing extracorporeal membrane oxygenation (ECMO). In this study, the new method is compared with two POCT methods and a laboratory-based anti-Xa assay., Methods: We obtained 760 whole blood samples from 13 patients undergoing ECMO. All samples were tested immediately by the LHMT, the Activated Clotting Time (ACT) test, and its low-range counterpart (ACT-LR). Aliquots from the same blood draw were frozen for later anti-Xa analysis using the Diagnostica Stago method on the Roche Cobas Fara-II., Results: The precision was best for duplicate citrated LHMT samples (CV = 3.1%). LHMT clotting times (overall median, 162 s) were typically shorter than ACT or ACT-LR times (247 and 235 s, respectively). The relationship between the LHMT and the other POCT methods differed significantly from patient to patient (P <0.0001), and a meaningful single relationship between the methods could not be obtained. The overall correlation coefficient between clotting time values and actual heparin concentrations was < or = 0.48 for each of the instruments tested, although time plots of each analyzer's data suggested that they detected heparin dosage changes within single patients., Conclusions: The performance of the LHMT on the TAS Analyzer is equivalent to that of currently commercially available POCT methods. The lack of agreement between absolute clotting time values and heparin concentrations suggests the need for reexamination of current ECMO patient management strategy.
- Published
- 2001
122. Correction of positive bias of the Roche Tina-quant II hemoglobin A1c (HbA1c) assay at low HbA1c percentages.
- Author
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Nowatzke WL, Parvin CA, Scott MG, Hock K, and Cole TG
- Subjects
- Humans, Reagent Kits, Diagnostic, Regression Analysis, Glycated Hemoglobin analysis
- Published
- 2001
123. Effect of NGF and neurotrophin-3 treatment on experimental diabetic autonomic neuropathy.
- Author
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Schmidt RE, Dorsey DA, Beaudet LN, Parvin CA, and Escandon E
- Subjects
- Animals, Axons drug effects, Axons pathology, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental metabolism, Disease Models, Animal, Ganglia, Sympathetic drug effects, Ganglia, Sympathetic ultrastructure, Intestines innervation, Male, Microscopy, Electron, Nerve Growth Factor metabolism, Neurotrophin 3 metabolism, Rats, Rats, Sprague-Dawley, Superior Cervical Ganglion drug effects, Superior Cervical Ganglion pathology, Sympathetic Fibers, Postganglionic drug effects, Sympathetic Fibers, Postganglionic ultrastructure, Diabetic Neuropathies drug therapy, Diabetic Neuropathies pathology, Ganglia, Sympathetic pathology, Nerve Growth Factor pharmacology, Neurotrophin 3 pharmacology, Sympathetic Fibers, Postganglionic pathology
- Abstract
Peripheral neuropathy is a significant complication of diabetes resulting in increased patient morbidity and mortality. Deficiencies of neurotrophic substances (e.g. NGE NT-3, and IGF-I) have been proposed as pathogenetic mechanisms in the development of distal symmetrical sensory diabetic polyneuropathy, and salutary effects of exogenous NGF administration have been reported in animal models. In comparison, relatively little is known concerning the effect of NGF on experimental diabetic sympathetic autonomic neuropathy. We have developed an experimental animal model of diabetic autonomic neuropathy characterized by the regular occurrence of pathologically distinctive dystrophic axons in prevertebral sympathetic ganglia and ileal mesenteric nerves of rats with chronic streptozotocin (STZ)-induced diabetes. Treatment of STZ-diabetic rats for 2-3 months with pharmacologic doses of NGF or NT-3, neurotrophic substances with known effects on the adult sympathetic nervous system, did not normalize established neuroaxonal dystrophy (NAD) in diabetic rats in the prevertebral superior mesenteric ganglia (SMG) and ileal mesenteric nerves as had pancreatic islet transplantation and IGF-I in earlier experiments. NGF treatment of control animals actually increased the frequency of NAD in the SMG. New data suggests that, in adult sympathetic ganglia. NGF may contribute to the pathogenesis of NAD rather than its amelioration, perhaps as the result of inducing intraganglionic axonal sprouts in which dystrophic changes are superimposed. NT-3 administration did not alter the frequency of NAD in diabetic animals, although it resulted in a significant decrease in NAD in control SMG. Although deficiencies of neurotrophic substances may represent the underlying pathogenesis of a variety of experimental neuropathies, delivery of excessive levels of selected substances may produce untoward effects.
- Published
- 2001
- Full Text
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124. Leptin in cerebrospinal fluid from children: correlation with plasma leptin, sexual dimorphism, and lack of protein binding.
- Author
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Landt M, Parvin CA, and Wong M
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- Adolescent, Body Mass Index, Child, Child, Preschool, Female, Humans, Infant, Leptin metabolism, Male, Protein Binding, Reference Values, Leptin blood, Leptin cerebrospinal fluid, Sex Characteristics
- Abstract
Background: Previous studies in adults have established that leptin is present at very low concentrations in cerebrospinal fluid (CSF), but few data exist concerning CSF leptin in children. Current evidence suggests that CSF leptin concentrations interact with hypothalamic centers controlling food intake. Serum leptin concentrations manifest a sexual dimorphism that arises during puberty., Methods: Leptin concentrations were determined in CSF from 42 pre- and postpubertal children who had been objectively classified into non-neurological disease or aseptic meningitis groups. Multivariate analysis of the dependence of CSF leptin on gender, pubertal state, body mass index (BMI), presence of aseptic meningitis, and CSF protein concentration was performed., Results: CSF leptin concentrations correlated with log-transformed plasma leptin concentrations in concomitantly collected samples (r = 0.582; P = 0.029). BMI and gender were significant determinants of CSF leptin in postpubertal children, but only BMI was significant in prepubertal children. Analysis with HPLC to separate protein-bound and free forms of leptin found only free leptin in CSF., Conclusions: CSF leptin concentrations in children reflect plasma leptin concentrations, including the advent of sexual dimorphism at puberty. Only free leptin is detectable in CSF, suggesting that it is the biologically active form.
- Published
- 2000
125. Insulin-like growth factor I reverses experimental diabetic autonomic neuropathy.
- Author
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Schmidt RE, Dorsey DA, Beaudet LN, Plurad SB, Parvin CA, and Miller MS
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- Animals, Diabetes Mellitus, Experimental pathology, Diabetes Mellitus, Experimental physiopathology, Diabetic Neuropathies pathology, Diabetic Neuropathies physiopathology, Humans, Insulin-Like Growth Factor I therapeutic use, Male, Microscopy, Electron, Rats, Rats, Sprague-Dawley, Streptozocin, Sympathetic Nervous System physiopathology, Sympathetic Nervous System ultrastructure, Diabetes Mellitus, Experimental drug therapy, Diabetic Neuropathies drug therapy, Insulin-Like Growth Factor I pharmacology, Sympathetic Nervous System drug effects
- Abstract
Recent studies have suggested a role for neurotrophic substances in the pathogenesis and treatment of diabetic neuropathy. In this study, the effect of insulin-like growth factor I (IGF-I) on diabetic sympathetic autonomic neuropathy was examined in an experimental streptozotocin-induced diabetic rat model. Two months of IGF-I treatment of chronically diabetic rats with established neuroaxonal dystrophy (the neuropathological hallmark of the disease) involving the superior mesenteric ganglion and ileal mesenteric nerves resulted in nearly complete normalization of the frequency of neuroaxonal dystrophy in both sites without altering the severity of diabetes. Treatment with low-dose insulin (to control for the transient glucose-lowering effects of IGF-I) failed to affect the frequency of ganglionic or mesenteric nerve neuroaxonal dystrophy or the severity of diabetes. The striking improvement in the severity of diabetic autonomic neuropathy shown with IGF-I treatment in these studies and the fidelity of the rat model to findings in diabetic human sympathetic ganglia provide promise for the development of new clinical therapeutic strategies.
- Published
- 1999
- Full Text
- View/download PDF
126. Tpm1, a locus controlling IL-12 responsiveness, acts by a cell-autonomous mechanism.
- Author
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Guler ML, Gorham JD, Dietrich WF, Murphy TL, Steen RG, Parvin CA, Fenoglio D, Grupe A, Peltz G, and Murphy KM
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- Alleles, Animals, Base Sequence, Chromosome Mapping, Crosses, Genetic, DNA Primers genetics, Female, Genetic Linkage, Genetic Markers, Genotype, Male, Mice, Mice, Inbred BALB C, Mice, Transgenic, Phenotype, Receptors, Antigen, T-Cell, alpha-beta genetics, Receptors, Interleukin genetics, Receptors, Interleukin-12, Recombination, Genetic, Sequence Tagged Sites, CD4-Positive T-Lymphocytes immunology, Interleukin-12 pharmacology
- Abstract
Th phenotype development is controlled not only by cytokines but also by other parameters including genetic background. One site of genetic variation between murine strains that has direct impact on Th development is the expression of the IL-12 receptor. T cells from B10.D2 and BALB/c mice show distinct control of IL-12 receptor expression. When activated by Ag, B10.D2 T cells express functional IL-12 receptors and maintain IL-12 responsiveness. In contrast, under the same conditions, BALB/c T cells fail to express IL-12 receptors and become unresponsive to IL-12, precluding any Th1-inducing effects if subsequently exposed to IL-12. Previously, we identified a locus, which we termed T cell phenotype modifier 1 (Tpm1), on murine chromosome 11 that controls this differential maintenance of IL-12 responsiveness. In this study, we have produced a higher resolution map around Tpm1. We produced and analyzed a series of recombinants from a first-generation backcross that significantly narrows the genetic boundaries of Tpm1. This allowed us to exclude from consideration certain previous candidates for Tpm1, including IFN-regulatory factor-1. Also, cellular analysis of F1(B10.D2 x BALB/c) T cells demonstrates that Tpm1 exerts its effect on IL-12 receptor expression in a cell-autonomous manner, rather than through influencing the extracellular milieu. This result strongly implies that despite the proximity of our locus to the IL-13/IL-4 gene cluster, these cytokines are not candidates for Tpm1.
- Published
- 1999
127. Effect of analytical run length on quality-control (QC) performance and the QC planning process.
- Author
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Parvin CA and Gronowski AM
- Subjects
- Chemistry, Clinical methods, Probability, Chemistry, Clinical statistics & numerical data, Quality Control
- Abstract
The performance measure traditionally used in the quality-control (QC) planning process is the probability of rejecting an analytical run when an out-of-control error condition exists. A shortcoming of this performance measure is that it doesn't allow comparison of QC strategies that define analytical runs differently. Accommodating different analytical run definitions is straightforward if QC performance is measured in terms of the average number of patient samples to error detection, or the average number of patient samples containing an analytical error that exceeds total allowable error. By using these performance measures to investigate the impact of different analytical run definitions on QC performance demonstrates that during routine QC monitoring, the length of the interval between QC tests can have a major influence on the expected number of unacceptable results produced during the existence of an out-of-control error condition.
- Published
- 1997
128. Dystrophic axonal swellings develop as a function of age and diabetes in human dorsal root ganglia.
- Author
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Schmidt RE, Dorsey D, Parvin CA, Beaudet LN, Plurad SB, and Roth KA
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- Adolescent, Adult, Aged, Child, Diabetes Mellitus ethnology, Diabetes Mellitus physiopathology, Female, Humans, Male, Middle Aged, Racial Groups, Sex Characteristics, Aging physiology, Axons ultrastructure, Diabetes Mellitus pathology, Ganglia, Spinal pathology
- Abstract
Neuroaxonal dystrophy, characterized by swollen axon terminals and, to a lesser degree, enlarged initial segments of axons or perikaryal projections, develops in human dorsal root sensory ganglia as a function of aging and diabetes. Lesions are typically located within the satellite cell capsule and are intimately applied to sensory neuronal perikarya, which are compressed and distorted but are otherwise normal. Swollen axons contain large numbers of neurofilaments that are immunoreactive with antisera to highly phosphorylated neurofilament epitopes but fail to stain with antisera directed against hypophosphorylated neurofilament epitopes. Other dystrophic swellings contain collections of tubulovesicular profiles admixed with neurotransmitter granules. Neuroaxonal dystrophy involves subpopulations of intraganglionic axons and apparent terminals, notably those containing CGRP, while apparently sparing others, including noradrenergic sympathetic axons. Diabetic subjects develop lesions prematurely and in greater numbers than in aged subjects. Individual dystrophic axons in diabetics and aged human subjects are identical in their light microscopic, immunohistochemical and ultrastructural appearance, suggesting the possibility of shared pathogenetic mechanisms.
- Published
- 1997
- Full Text
- View/download PDF
129. Quality-control (QC) performance measures and the QC planning process.
- Author
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Parvin CA
- Subjects
- Chemistry, Clinical statistics & numerical data, Probability, Sensitivity and Specificity, Laboratories statistics & numerical data, Quality Control
- Abstract
Numerous outcome measures can be used to characterize and compare the performance of alternative quality-control (QC) strategies. The performance measure traditionally used in the QC planning process is the probability of rejecting an analytical run when a critical out-of-control error condition exists. Another performance measure that naturally fits within the total allowable error paradigm is the probability that a reported test result contains an analytical error that exceeds the total allowable error specification. In general, the out-of-control error conditions associated with the greatest chance of reporting an unacceptable test result are unrelated to the traditionally defined "critical" error conditions. If the probability of reporting an unacceptable test result is used as the primary performance measure, worst-case QC performance can be determined irrespective of the magnitude of any out-of-control error condition that may exist, thus eliminating the need for the concept of a "critical" out-of-control error.
- Published
- 1997
130. Using Logical Observation Identifier Names and Codes (LOINC) to exchange laboratory data among three academic hospitals.
- Author
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Baorto DM, Cimino JJ, Parvin CA, and Kahn MG
- Subjects
- Clinical Laboratory Techniques statistics & numerical data, Databases, Factual, Heart Failure diagnosis, Humans, Academic Medical Centers organization & administration, Clinical Laboratory Information Systems standards, Medical Record Linkage methods, Vocabulary, Controlled
- Abstract
Using a standard set of names and codes to exchange electronic laboratory data would facilitate multiinstitutional research and data pooling. This need has led to the development of the Logical Observation Identifier Names and Codes (LOINC) database and its test naming convention. We conducted a study which required 3 academic hospitals (in 2 separate medical centers) to extract raw laboratory data from their local information system for a defined patient population, translate tests into LOINC, and provide aggregate data which could then be used to compare laboratory utilization. We found that the coding of local tests into LOINC can often be complex, especially the "Kind of Property" field, and apparently trivial differences in choices made by individual institutions can result in nonmatches in electronically pooled data. In our study, 72-86% of the failures of LOINC to match the same tests between different institutions were due to differences in local coding choices. LOINC has tremendous potential to eliminate the needing for detailed human inspection during the pooling of laboratory data from diverse sites, and perhaps even a built-in capability to adjust matching stringency by selecting subsets of LOINC fields required to match. However, a quality, standard coding procedure at all sites is critical.
- Published
- 1997
131. The endogenous erythropoietin response and the erythropoietic response to blood loss anemia: the effects of age and gender.
- Author
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Goodnough LT, Price TH, and Parvin CA
- Subjects
- Adolescent, Adult, Aged, Anemia drug therapy, Anemia etiology, Bloodletting, Child, Female, Hematocrit, Hemoglobins metabolism, Humans, Male, Middle Aged, Aging blood, Anemia blood, Erythropoietin blood, Erythropoietin therapeutic use, Sex Characteristics
- Abstract
The endogenous erythropoietin (EPO) response and the erythropoietic response to anemia in the elderly, as compared with that in younger subjects, is controversial. We therefore studied autologous blood donors undergoing aggressive phlebotomy to determine the effect of age and gender on the EPO response to blood loss anemia, along with the erythropoietic response to endogenous EPO and to exogenous recombinant human EPO therapy. Seventy-one patients underwent phlebotomy, up to 6 units over 3 weeks, and received either placebo (n = 18), EPO 150 U/kg (n = 16), EPO 300 U/kg (n = 18), or EPO 600 U/kg (n = 19) at each of the six visits. Linear regression analysis of the hemoglobin/log EPO relationship for 18 placebo patients revealed no differences in the endogenous EPO response to phlebotomy, as determined by the slopes and intercepts, for males versus females or as a function of age. We found no differences in endogenous EPO-stimulated red blood cell (RBC) volume expansion for males and females (7.06 +/- 2.4 and 7.22 +/- 2.2 ml/kg, respectively, p = 0.88) or as a function of age (estimated rate of change = -0.58 +/- 0.33 ml/kg for every 10 years of life, p = 0.10). Similarly, we found no differences in RBC response to EPO for males versus females (1.4 +/- 0.3 ml/kg vs 1.5 +/- 0.3 ml/kg per 1000 U/kg EPO, respectively, p = 0.80) or as a function of age (estimated rate of change = 0.051 +/- 0.15 ml/kg per 1000 U/kg EPO for every 10 years of life, p = 0.74).(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1995
132. Erythropoietin response to anaemia is not altered by surgery or recombinant human erythropoietin therapy.
- Author
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Goodnough LT, Price TH, Parvin CA, Friedman KD, Vogler WR, Khan N, Sacher R, Johnston M, Wissel M, and Ciavarella D
- Subjects
- Adult, Aged, Anemia etiology, Anemia therapy, Blood Transfusion, Autologous, Bloodletting, Double-Blind Method, Female, Hemoglobins analysis, Humans, Male, Middle Aged, Postoperative Period, Recombinant Proteins therapeutic use, Anemia blood, Erythropoietin blood, Erythropoietin therapeutic use, Surgical Procedures, Operative
- Abstract
Recombinant human erythropoietin (EPO) therapy has been shown to increase red blood cell (RBC) production and facilitate autologous blood donation before elective surgery. However, recent reports have suggested that surgery and/or EPO therapy may suppress endogenous erythropoietin secretion in response to anaemia. We therefore analysed the haemoglobin/erythropoietin relationship preoperatively and postoperatively in 71 autologous blood donors subjected to aggressive phlebotomy and six treatments with either EPO (150 U/kg, n = 16, 300 U/kg, n = 18, or 600 U/kg, n = 19) or placebo (n = 18). Using data from the three preoperative study visits, the linear relationship between log erythropoietin and haemoglobin was determined for each of the 18 placebo patients. We found no significant differences in the slopes of the relationships in this group during aggressive phlebotomy. Furthermore, there was no evidence of a significant difference in the erythropoietin level recorded postoperatively for each patient to that predicted from the patient's postoperative haemoglobin level, based on the haemoglobin/log erythropoietin relationship preoperatively. Similarly, for each of the EPO-treated groups, there was no evidence of a significant difference when comparing the recorded erythropoietin level to that predicted from each patient's postoperative haemoglobin level, based on the haemoglobin/log erythropoietin relationship preoperatively. We conclude that preoperative recombinant human erythropoietin therapy and/or surgery do not adversely affect the postoperative erythropoietin response to anaemia.
- Published
- 1994
- Full Text
- View/download PDF
133. Effect of diabetes and aging on human sympathetic autonomic ganglia.
- Author
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Schmidt RE, Plurad SB, Parvin CA, and Roth KA
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Aging physiology, Autonomic Nervous System Diseases pathology, Axons pathology, Female, Humans, Male, Middle Aged, Neurons pathology, Aging pathology, Diabetic Neuropathies pathology, Ganglia, Sympathetic pathology
- Abstract
Although autonomic dysfunction frequently complicates the clinical course of patients with diabetes, relatively little is known of its underlying neuropathology. Using experimental animal models as a guide, the prevertebral superior mesenteric (SMG) and paravertebral superior cervical (SCG) sympathetic ganglia have been examined in a series of adult autopsied diabetic and non-diabetic patients of various ages using histochemical, ultrastructural, morphometric, and immunohistochemical methods. Quantitative studies demonstrated that markedly swollen argyrophilic terminal axons (neuroaxonal dystrophy) containing large numbers of disorganized neurofilaments developed in the SMG but not SCG as a function of diabetes, increasing age, and gender (males were more severely affected than females). As in experimental animals, diabetic (types I and II) patients developed histologically identical lesions prematurely and in greater numbers than age-matched nondiabetic patients. Morphometric studies showed a small but statistically significant decrease in neuronal density in the SMG but not SCG of diabetic patients. The dimensions of individual sympathetic neurons were not significantly different in aging or diabetes. The pathological lesions identified in the SMG may contribute to the autonomic dysfunction so commonly observed in diabetic patients.
- Published
- 1993
134. Germinal center T cells are distinct helper-inducer T cells.
- Author
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Bowen MB, Butch AW, Parvin CA, Levine A, and Nahm MH
- Subjects
- Antigens, CD biosynthesis, Antigens, Differentiation, T-Lymphocyte biosynthesis, CD57 Antigens, Cells, Enzyme-Linked Immunosorbent Assay, Fluorescent Antibody Technique, HLA-DR Antigens biosynthesis, Histocompatibility Antigens biosynthesis, Humans, Immunophenotyping, Interferon-gamma analysis, Interleukin-2 metabolism, Interleukin-4 metabolism, Lectins, C-Type, Leukocyte Common Antigens, Palatine Tonsil immunology, Phytohemagglutinins pharmacology, Receptors, Interleukin-2 biosynthesis, Tumor Necrosis Factor-alpha biosynthesis, Lymph Nodes cytology, T-Lymphocytes, Helper-Inducer immunology
- Abstract
Germinal centers (GCs) contain a significant number of CD4+ T cells, but what role these T cells may play in the development of GC B cells has not been determined. To gain insight into their role, we studied the phenotype of GC T cells and the lymphokines secreted by GC T cells isolated from human tonsils obtained after tonsillectomies. In addition to confirming that a large fraction of GC T cells are Leu-7(CD57)+ and Leu-8-, we found that they have no binding sites for peanut agglutinin. Furthermore, we found that they are CD45RA- and CD45R0+, the phenotype of helper-inducer T cells. We also found that Leu-7(CD57)+ cells display CD69, a phenotypic marker of very early cell activation, but do not display three other markers of cell activation: CD25 [interleukin-2 (IL-2) receptor], CD71 (transferrin receptor), and DR. When isolated, Leu-7(CD57)+ cells were stimulated in vitro with a mitogen that can induce peripheral blood T cells with the helper-inducer phenotype to produce various cytokines, Leu-7(CD57)+ cells did not produce IL-2, interleukin-4 (IL-4), interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha) in significant amounts. Taken together, GC T cells from a distinct subpopulation of T cells with helper-inducer phenotype by their histologic location, by their surface phenotype, and by their ability to produce lymphokines. This finding is consistent with the possibility that GC T cells have been selectively recruited to actively help B cells develop in GCs.
- Published
- 1991
- Full Text
- View/download PDF
135. Neuroaxonal dystrophy in aging human sympathetic ganglia.
- Author
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Schmidt RE, Chae HY, Parvin CA, and Roth KA
- Subjects
- Adult, Aged, Aging metabolism, Autopsy, Axons metabolism, Axons pathology, Axons ultrastructure, Enkephalin, Methionine metabolism, Ganglia, Sympathetic metabolism, Ganglia, Sympathetic ultrastructure, Gastrin-Releasing Peptide, Humans, Immunohistochemistry, Microscopy, Electron, Middle Aged, Nervous System Diseases metabolism, Neurons metabolism, Neurons pathology, Neurons ultrastructure, Neuropeptide Y metabolism, Peptides metabolism, Substance P metabolism, Synapses metabolism, Synapses pathology, Synapses ultrastructure, Time Factors, Tyrosine 3-Monooxygenase metabolism, Vasoactive Intestinal Peptide metabolism, Aging pathology, Ganglia, Sympathetic pathology, Nervous System Diseases pathology
- Abstract
Autonomic dysfunction is an increasingly recognized problem in aging animals and man. The pathologic changes that produce autonomic dysfunction in human aging are largely unknown; however, in experimental animal models specific pathologic changes have been found in selected sympathetic ganglia. To address whether similar neuropathologic changes occur in aging humans, the authors have examined paravertebral and prevertebral sympathetic ganglia from a series of 56 adult autopsied nondiabetic patients. They found significant, specific, age-related neuropathologic lesions in the prevertebral sympathetic superior mesenteric ganglia of autopsied patients. Markedly swollen dystrophic preterminal axons compressed or displaced the perikarya of principal sympathetic neurons. Ultrastructurally, these swollen presynaptic axons contained abundant disoriented neurofilaments surrounded by peripherally marginated dense core vesicles. Immunohistochemical studies demonstrated that dystrophic axons contained tyrosine hydroxylase and neuropeptide tyrosine (NPY)-like immunoreactivity but not other neuropeptides (VIP, substance P, gastrin-releasing peptide [GRP]/bombesin, met-enkephalin). Similar to the animal models of aging, lesions were much more frequent in the prevertebral superior mesenteric ganglia than in the paravertebral superior cervical ganglia. These studies demonstrate anatomic, peptidergic, and pathologic specificity in the aging human nervous system similar in many respects to that which the authors have described in experimental animal models. Neuroaxonal dystrophy in the sympathetic nervous system may underlie poorly understood alterations in clinical autonomic nervous system function that develop with age.
- Published
- 1990
136. Differential susceptibility of prevertebral and paravertebral sympathetic ganglia to experimental injury.
- Author
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Schmidt RE, McAtee SJ, Plurad DA, Parvin CA, Cogswell BE, and Roth KA
- Subjects
- Animals, Catecholamines analysis, Fluorescent Antibody Technique, Ganglia, Sympathetic drug effects, Ganglia, Sympathetic enzymology, Immune Sera, Nerve Growth Factors immunology, Nerve Growth Factors physiology, Neurons cytology, Neurons drug effects, Neurons enzymology, Neuropeptide Y analysis, Oxidopamine, Rats, Rats, Inbred Strains, Reference Values, Tyrosine 3-Monooxygenase metabolism, Ganglia, Sympathetic pathology, Guanethidine toxicity, Hydroxydopamines toxicity, Nerve Growth Factors pharmacology
- Abstract
To investigate the response of selected sympathetic ganglia to experimental injury, neonatal rat pups were treated with either 6-hydroxydopamine (6-OHDA), guanethidine, or antiserum to nerve growth factor (anti-NGF). When examined at one month of age, each of the treatments resulted in a significantly greater loss of neurons and tyrosine hydroxylase activity in paravertebral (superior cervical and stellate) versus prevertebral (superior mesenteric and celiac) sympathetic ganglia. Guanethidine treatment produced the largest differential in neuron loss and tyrosine hydroxylase activity between pre- and paravertebral ganglia. Histologically, the acute phase of guanethidine-induced injury in the superior cervical, paravertebral, ganglia was characterized by a prominent mononuclear cell infiltrate and extensive neuronal degeneration. Minimal histopathologic changes were seen in the superior mesenteric, prevertebral, ganglia of the same animals. Immunolocalization of tyrosine hydroxylase and neuropeptide Y (NPY) in guanethidine-treated animals showed a preferential loss of sympathetic innervation of the extramural mesenteric vasculature with relative sparing of the noradrenergic innervation of Auerbach's myenteric plexus. Differences in the susceptibility of sympathetic ganglia to various insults may underlie the selective and heterogeneous involvement of sympathetic ganglia in clinical and experimental situations.
- Published
- 1988
- Full Text
- View/download PDF
137. In vitro immunization to KLH. II. Limiting dilution analysis of antigen-reactive cells in primary and secondary culture.
- Author
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Gebel HM, Scott JR, Parvin CA, and Rodey GE
- Subjects
- Cells, Cultured, Dose-Response Relationship, Immunologic, Epitopes, Genes, MHC Class II, Hemocyanins immunology, Humans, Immunologic Memory, Receptors, Antigen, T-Cell immunology, Lymphocyte Activation, T-Lymphocytes immunology
- Abstract
Limiting dilution analysis was used to estimate the frequency of human peripheral blood T lymphocytes that proliferate in response to in vitro immunization with keyhole limpet hemocyanin (KLH). Antigen-reactive cells (ARC) were estimated 9 days after primary immunization with KLH. The ARC frequency of lymphocytes from 12 subjects ranged from 1:23,800 to 1:52,631. Lymphocytes from five of these subjects were also primed for 12 days with KLH, rechallenged in secondary culture with fresh adherent cells and KLH, and assayed 4 days later. The ARC frequency increased to 1:1,123 to 1:7,247, indicating that T cell clones responsive to KLH had expanded during primary culture. In addition, we observed that the proliferative response of lymphocytes from 5 of the 12 subjects were inhibited at high cell concentrations. Depletion of OKT8+ T cells before culturing with KLH however did not alter the inhibitory effect of high concentrations of T cells.
- Published
- 1983
138. Clinical predictors of theophylline blood levels in asthmatic patients.
- Author
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Stine RJ, Marcus RH, and Parvin CA
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Asthma drug therapy, Delayed-Action Preparations, Emergency Medical Services, Female, Humans, Male, Mathematics, Middle Aged, Outpatients, Theophylline therapeutic use, Asthma blood, Theophylline blood
- Abstract
To determine the usefulness of clinical information in predicting theophylline levels, 21 parameters were studied in 204 asthmatic patients. The best single parameter for predicting theophylline levels was the last outpatient level (r = 0.484), which was within +/- 5 micrograms/mL of the presenting theophylline level in 62.5% of cases. However, there was considerable variability in theophylline levels in the other 37.5% of cases. The best combination of predictors was the last outpatient level and time since the last dose in patients taking a short-acting preparation. Even with this combination, however, 20.8% of predicted levels fell outside a range of +/- 5 micrograms/mL of the presenting theophylline levels. The only patients in whom a theophylline level could be predicted reliably were those who reported taking a sustained-release or short-acting preparation more than 15 or 8 hours prior to evaluation, respectively. In these patients, all presenting theophylline levels were in the subtherapeutic range (ie, less than 10 micrograms/mL), with 92% of the levels less than 5 micrograms/mL. Except for these patients, readily available theophylline determinations are necessary in order to optimize theophylline therapy with minimal risk of toxicity.
- Published
- 1987
- Full Text
- View/download PDF
139. Cephalic index: a gestational age-dependent biometric parameter.
- Author
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Gray DL, Songster GS, Parvin CA, and Crane JP
- Subjects
- Female, Fetal Monitoring, Humans, Pregnancy, Reference Values, Ultrasonography, Cephalometry, Gestational Age
- Abstract
Cephalic index was proposed originally as a means of recognizing altered head shape and confirming the validity of biparietal diameter (BPD) measurements. Two previous studies found cephalic index to be gestational age-independent. We tested this relationship by regression analysis in 777 well-dated pregnancies, evenly distributed between 14-40 weeks' gestation. Significant variation in cephalic index was found with advancing gestational age, with the highest and lowest values observed at 14 and 28 weeks, respectively. Based upon application in a separate test population of 1361 normal fetuses, a threshold of +/- 1 SD maximized identification of misleading BPDs due to altered head shape.
- Published
- 1989
140. Aminophylline loading in asthmatic patients: a protocol trial.
- Author
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Stine RJ, Marcus RH, and Parvin CA
- Subjects
- Adolescent, Adult, Aged, Aging blood, Aging drug effects, Aminophylline adverse effects, Asthma blood, Body Weight, Clinical Trials as Topic, Emergencies, Female, Humans, Male, Middle Aged, Theophylline administration & dosage, Theophylline blood, Time Factors, Aminophylline administration & dosage, Asthma drug therapy
- Abstract
We tested an aminophylline loading-dose protocol in which asthmatic patients presenting to an emergency department were given a half (3 mg/kg) IV loading dose based on total body weight (TBW) if they had taken a short-acting or sustained-release theophylline preparation within 12 or 24 hours, respectively, prior to arrival: otherwise, a full (6 mg/kg) loading dose was administered. Of the 28 patients given a full loading dose, 20 (71.4%) achieved a postload therapeutic level (10 to 20 micrograms/mL), and none developed a toxic level (greater than 20 micrograms/mL). Although 34 (60.7%) of 56 patients given a half loading dose attained a postload therapeutic level, 13 patients (23.2%) entered the toxic range. We were able to predict that loading doses of 7.6 mg/kg and 3.8 mg/kg based on ideal body weight (IBW) would have yielded very similar results. The mean change in theophylline level per mg/kg TBW of administered aminophylline was 2.01 micrograms/mL. When calculated on the basis of IBW, the mean change in theophylline level was 1.58 micrograms/mL. Evaluation of the change in theophylline level resulting from aminophylline loading doses based on either TBW or IBW revealed that each dosing method produced changes in blood level with similar variability that were not independent of obesity, indicating that neither dosing method is superior to the other. Thus, patients who report not having taken a theophylline preparation within the above time limits can be given a full aminophylline loading dose of either 6 mg/kg based on TBW or 7.6 mg/kg based on IBW. Other patients, however, require a preload blood level determination to optimize therapy and avoid toxic levels.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1989
- Full Text
- View/download PDF
141. A BASIC computer program for evaluating the effect of sample distribution on the least-squares regression slope estimate.
- Author
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Parvin CA
- Subjects
- Clinical Laboratory Techniques, Humans, Microcomputers, Models, Theoretical, Sampling Studies, Computers, Regression Analysis, Software
- Abstract
Least-squares regression analysis is widely used in analytical method comparison studies even though model assumptions are typically violated. The advantages favoring the use of the least-squares technique, when applicable, are that its theoretical characteristics are thoroughly developed and the calculations are straightforward and universally known. In order to aid an investigator in determining whether or not the least-squares technique can be acceptably applied in a given method comparison situation, a BASIC computer program is developed that evaluates the bias of the least-squares slope estimate as a function of the precision characteristics of the analytical methods and the proposed sampling distribution for the method comparison experiment.
- Published
- 1985
- Full Text
- View/download PDF
142. Extending the capabilities of a laboratory computer system through cooperative processing.
- Author
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Parvin CA and Hockett RD
- Subjects
- Software, Clinical Laboratory Information Systems, Computer Communication Networks, Computer Graphics, Computer Systems, Information Systems, Laboratories, Hospital organization & administration, Medical Records
- Abstract
The concept of cooperative processing within the context of a hospital or laboratory computer systems environment is introduced. Two examples that produce graphical display of laboratory data are described to illustrate cooperative processing's ability to enhance a system's functionality without placing significant additional burden on system resources.
- Published
- 1987
- Full Text
- View/download PDF
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