17 results on '"Kelley JC"'
Search Results
2. Hypercalcemia Secondary to Elevated PTHrP in an Infant Followed by Progression to Nephrotic Syndrome.
- Author
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Gimeno AF, Hunley TE, and Kelley JC
- Abstract
In infants, hypercalcemia from elevated parathyroid hormone-related protein (PTHrP) is rare, often signaling neoplasm or renal or urinary anomalies. We report an infant who presented with failure to thrive and hypercalcemia at 10 months old, with initial evaluation showing elevated PTHrP of unclear etiology with imaging negative for neoplasm and no structural anomalies of the kidneys or ureters on ultrasound. Within 6 months of presentation, the patient developed nephrotic syndrome and by 2 years had progressed to end-stage kidney disease, necessitating kidney transplantation. Genetic testing was inconclusive but suggested congenital nephrotic syndrome. While reports of hypercalcemia secondary to elevated PTHrP exist in children with known structural renal anomalies, this is the first to demonstrate hypercalcemia and PTHrP elevation before detection of renal abnormalities. Experimental models have suggested a role for increased PTHrP expression in renal cells following acute kidney injury from nephrotic syndrome, and clinically detectable PTHrP levels may indicate progression of renal injury. We suggest monitoring of renal function for early detection of nephrotic syndrome in infants and children with elevated PTHrP who otherwise lack anatomical renal anomalies or detectable malignancies., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)
- Published
- 2024
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3. Protecting Outdoor Workers From Climate Change Impacts Through Interdisciplinary Collaboration.
- Author
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Kelley JC and Tsai JH
- Subjects
- Humans, Climate Change
- Abstract
Competing Interests: Conflict of InterestThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2024
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4. Intraoperative diagnosis of type 1 diabetes and diabetic ketoacidosis during scoliosis surgery.
- Author
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Loh KH, Kelley JC, and Eagle SS
- Subjects
- Child, Adolescent, Humans, Diabetes Mellitus, Type 1 complications, Diabetic Ketoacidosis diagnosis, Diabetic Ketoacidosis therapy, Scoliosis surgery
- Abstract
Diabetic ketoacidosis is the leading cause of morbidity and mortality in children with type 1 diabetes. Management of diabetic ketoacidosis requires meticulous monitoring and treatment of severe dehydration and metabolic derangement. We present an adolescent patient who was diagnosed with diabetic ketoacidosis during spinal fusion for idiopathic scoliosis and discuss the management of this unexpected intraoperative emergency., (© 2023 John Wiley & Sons Ltd.)
- Published
- 2023
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5. Long-term Continuous Glucose Monitor Use in Very Young Children With Type 1 Diabetes: One-Year Results From the SENCE Study.
- Author
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Van Name MA, Kanapka LG, DiMeglio LA, Miller KM, Albanese-O'Neill A, Commissariat P, Corathers SD, Harrington KR, Hilliard ME, Anderson BJ, Kelley JC, Laffel LM, MacLeish SA, Nathan BM, Tamborlane WV, Wadwa RP, Willi SM, Williams KM, Wintergerst KA, Woerner S, Wong JC, and DeSalvo DJ
- Subjects
- Humans, Child, Child, Preschool, Blood Glucose, Blood Glucose Self-Monitoring, Diabetes Mellitus, Type 1 drug therapy, Hypoglycemia, Hyperglycemia
- Abstract
Objectives: Achieving optimal glycemic outcomes in young children with type 1 diabetes (T1D) is challenging. This study examined the durability of continuous glucose monitoring (CGM) coupled with a family behavioral intervention (FBI) to improve glycemia., Study Design: This one-year study included an initial 26-week randomized controlled trial of CGM with FBI ( CGM+FBI ) and CGM alone ( Standard-CGM ) compared with blood glucose monitoring (BGM), followed by a 26-week extension phase wherein the BGM Group received the CGM+FBI ( BGM-Crossover ) and both original CGM groups continued this technology., Results: Time in range (70-180 mg/dL) did not improve with CGM use (CGM+FBI: baseline 37%, 52 weeks 41%; Standard-CGM: baseline 41%, 52 weeks 44%; BGM-Crossover: 26 weeks 38%, 52 weeks 40%). All three groups sustained decreases in hypoglycemia (<70 mg/dL) with CGM use (CGM+FBI: baseline 3.4%, 52 weeks 2.0%; Standard-CGM: baseline 4.1%, 52 weeks 2.1%; BGM-Crossover: 26 weeks 4.5%, 52 weeks 1.7%, P -values <.001). Hemoglobin A1c was unchanged with CGM use (CGM+FBI: baseline 8.3%, 52 weeks 8.2%; Standard-CGM: baseline 8.2%, 52 weeks 8.0%; BGM-Crossover: 26 weeks 8.1%, 52 weeks 8.3%). Sensor use remained high (52-week study visit: CGM+FBI 91%, Standard-CGM 92%, BGM-Crossover 88%)., Conclusion: Over 12 months young children with T1D using newer CGM technology sustained reductions in hypoglycemia and, in contrast to prior studies, persistently wore CGM. However, pervasive hyperglycemia remained unmitigated. This indicates an urgent need for further advances in diabetes technology, behavioral support, and diabetes management educational approaches to optimize glycemia in young children.
- Published
- 2023
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6. Poor Glycemic Control Is Associated With Impaired Bone Accrual in the Year Following a Diagnosis of Type 1 Diabetes.
- Author
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Weber DR, Gordon RJ, Kelley JC, Leonard MB, Willi SM, Hatch-Stein J, Kelly A, Kosacci O, Kucheruk O, Kaafarani M, and Zemel BS
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- Adolescent, Bone Development, Bone and Bones pathology, C-Peptide metabolism, Cancellous Bone diagnostic imaging, Cancellous Bone pathology, Child, Cortical Bone diagnostic imaging, Cortical Bone pathology, Diabetes Mellitus, Type 1 drug therapy, Female, Humans, Hypoglycemic Agents therapeutic use, Male, Organ Size, Periosteum diagnostic imaging, Bone Density, Bone and Bones diagnostic imaging, Diabetes Mellitus, Type 1 metabolism, Glycated Hemoglobin metabolism, Osteogenesis
- Abstract
Context: Type 1 diabetes (T1D) is associated with an increased fracture risk across the life course. The effects on bone accrual early in the disease are unknown., Objective: To characterize changes in bone density and structure over the year following diagnosis of T1D and to identify contributors to impaired bone accrual., Design: Prospective cohort study., Setting: Academic children's hospital., Participants: Thirty-six children, ages 7 to 17 years, enrolled at diagnosis of T1D., Outcomes: Whole body and regional dual-energy X-ray absorptiometry and tibia peripheral quantitative computed tomography obtained at baseline and 12 months. The primary outcome was bone accrual assessed by bone mineral content (BMC) and areal bone mineral density (aBMD) velocity z score., Results: Participants had low total body less head (TBLH) BMC (z = -0.46 ± 0.76), femoral neck aBMD (z = -0.57 ± 0.99), and tibia cortical volumetric BMD (z = -0.44 ± 1.11) at diagnosis, compared with reference data, P < 0.05. TBLH BMC velocity in the year following diagnosis was lower in participants with poor (hemoglobin A1c ≥7.5%) vs good (hemoglobin A1c <7.5%) glycemic control at 12 months, z = -0.36 ± 0.84 vs 0.58 ± 0.71, P = 0.003. TBLH BMC velocity was correlated with gains in tibia cortical area (R = 0.71, P = 0.003) and periosteal circumference (R = 0.67, P = 0.007) z scores in participants with good, but not poor control., Conclusions: Our results suggest that the adverse effects of T1D on BMD develop early in the disease. Bone accrual following diagnosis was impaired in participants with poor glycemic control and appeared to be mediated by diminished bone formation on the periosteal surface., (Copyright © 2019 Endocrine Society.)
- Published
- 2019
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7. Relationship between chronic testicular pain and mental health diagnoses.
- Author
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Mwamukonda KB, Kelley JC, Cho DS, and Smitherman A
- Abstract
Background: Chronic testicular pain (orchialgia) has been defined as intermittent or constant unilateral or bilateral testicular pain that lasts 3 months or longer, significantly interfering with daily activities, and prompting the patient to seek medical attention. In many instances, the etiology of the pain is not identified. The contribution of psychological factors is unclear. The purpose of this study was to identify the categories of mental health (MH) diagnoses that are most frequently associated with orchialgia and determine if a correlation exists between MH diagnoses and orchialgia., Methods: A retrospective review was performed to identify all adult patients within the San Antonio Military Health System with a new diagnosis of orchialgia from January 2005 to April 2015. Patients with acute pathology or recent inguinal/scrotal surgery were excluded. A comparative cohort of all men presenting with hydroceles within the same timeframe was obtained. The presence of coexisting MH diagnoses in both cohorts was then determined., Results: Four hundred and forty-four men met the inclusion criteria for orchialgia, with 133 men presenting with hydroceles. The incidence of orchialgia increased significantly over the study period (P=0.001). MH diagnoses in the study population did trend upward over the years, but not significantly (P=0.063). MH diagnoses were not significantly higher in the cases compared to the controls (21.6% vs. 18.8%, P=0.479). The prevalence of anxiety was twice as high in the cases (9% vs. 4.5%), though not significantly (P=0.075). The prevalence of all MH diagnoses was significantly higher than in the general US population based on National Institute of Mental Health statistics., Conclusions: The incidence of orchialgia rose significantly over time, but it was not significantly associated with MH diagnoses. These results may also be skewed by the overall higher percentage of MH diagnoses in the study population than in the general population., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.
- Published
- 2019
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8. Effects of a Randomized Weight Loss Intervention Trial in Obese Adolescents on Tibia and Radius Bone Geometry and Volumetric Density.
- Author
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Kelley JC, Stettler-Davis N, Leonard MB, Hill D, Wrotniak BH, Shults J, Stallings VA, Berkowitz R, Xanthopoulos MS, Prout-Parks E, Klieger SB, and Zemel BS
- Subjects
- Adolescent, Body Composition, Body Mass Index, Female, Humans, Male, Bone Density, Obesity physiopathology, Obesity therapy, Radius pathology, Radius physiopathology, Tibia pathology, Tibia physiopathology, Weight Loss
- Abstract
Obese adolescents have increased fracture risk, but effects of alterations in adiposity on bone accrual and strength in obese adolescents are not understood. We evaluated 12-month changes in trabecular and cortical volumetric bone mineral density (vBMD) and cortical geometry in obese adolescents undergoing a randomized weight management program, and investigated the effect of body composition changes on bone outcomes. Peripheral quantitative computed tomography (pQCT) of the radius and tibia, and whole-body dual-energy X-ray absorptiometry (DXA) scans were obtained at baseline, 6 months, and 12 months in 91 obese adolescents randomized to standard care versus behavioral intervention for weight loss. Longitudinal models assessed effects of body composition changes on bone outcomes, adjusted for age, bone length, and African-American ancestry, and stratified by sex. Secondary analyses included adjustment for physical activity, maturation, vitamin D, and inflammatory biomarkers. Baseline body mass index (BMI) was similar between intervention groups. Twelve-month change in BMI in the standard care group was 1.0 kg/m
2 versus -0.4 kg/m2 in the behavioral intervention group (p < 0.01). Intervention groups were similar in bone outcomes, so they were combined for subsequent analyses. For the tibia, BMI change was not associated with change in vBMD or structure. Greater baseline lean body mass index (LBMI) associated with higher cortical vBMD in males, trabecular vBMD in females, and polar section modulus (pZ) and periosteal circumference (Peri-C) in both sexes. In females, change in LBMI positively associated with gains in pZ and Peri-C. Baseline visceral adipose tissue (VFAT) was inversely associated with pZ in males and cortical vBMD in females. Change in VFAT did not affect bone outcomes. For the radius, BMI and LBMI changes positively associated with pZ in males. Thus, in obese adolescents, weight loss intervention with modest changes in BMI was not detrimental to radius or tibia bone strength, and changes in lean, but not adiposity, measures were beneficial to bone development. © 2017 American Society for Bone and Mineral Research., (© 2017 American Society for Bone and Mineral Research.)- Published
- 2018
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9. A case of severe acquired hypertriglyceridemia in a 7-year-old girl.
- Author
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Lilley JS, Linton MF, Kelley JC, Graham TB, Fazio S, and Tavori H
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- Autoantibodies blood, Autoantibodies immunology, Autoimmunity immunology, Child, Female, Heterozygote, Humans, Hyperlipoproteinemia Type I blood, Hyperlipoproteinemia Type I immunology, Hyperlipoproteinemia Type I physiopathology, Lipoprotein Lipase immunology, Mutation, Prednisone administration & dosage, Sjogren's Syndrome genetics, Sjogren's Syndrome physiopathology, Autoimmunity genetics, Hyperlipoproteinemia Type I genetics, Lipoprotein Lipase genetics, Triglycerides blood
- Abstract
We report a case of severe type I hyperlipoproteinemia caused by autoimmunity against lipoprotein lipase (LPL) in the context of presymptomatic Sjögren's syndrome. A 7-year-old mixed race (Caucasian/African American) girl was admitted to the intensive care unit at Vanderbilt Children's Hospital with acute pancreatitis and shock. She was previously healthy aside from asthma and history of Hashimoto's thyroiditis. Admission triglycerides (TGs) were 2191 mg/dL but returned to normal during the hospital stay and in the absence of food intake. At discharge, she was placed on a low-fat, low-sugar diet. She did not respond to fibrates, prescription fish oil, metformin, or orlistat, and during the following 2 years, she was hospitalized several times with recurrent pancreatitis. Except for a heterozygous mutation in the promoter region of LPL, predicted to have no clinical significance, she had no further mutations in genes known to affect TG metabolism and to cause inherited type I hyperlipoproteinemia, such as APOA5, APOC2, GPIHBP1, or LMF1. When her TG levels normalized after incidental use of prednisone, an autoimmune mechanism was suspected. Immunoblot analyses showed the presence of autoantibodies to LPL in the patient's plasma. Autoantibodies to LPL decreased by 37% while patient was on prednisone, and by 68% as she subsequently transitioned to hydroxychloroquine monotherapy. While on hydroxychloroquine, she underwent a supervised high-fat meal challenge and showed normal ability to metabolize TG. For the past 3 years and 6 months, she has had TG consistently <250 mg/dL, and no symptoms of, or readmissions for, pancreatitis., (Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
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10. Bone Density in the Obese Child: Clinical Considerations and Diagnostic Challenges.
- Author
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Kelley JC, Crabtree N, and Zemel BS
- Subjects
- Absorptiometry, Photon, Body Composition, Child, Female, Humans, Male, Bone Density physiology, Obesity complications
- Abstract
The prevalence of obesity in children has reached epidemic proportions. Concern about bone health in obese children, in part, derives from the potentially increased fracture risk associated with obesity. Additional risk factors that affect bone mineral accretion, may also contribute to obesity, such as low physical activity and nutritional factors. Consequences of obesity, such as inflammation, insulin resistance, and non-alcoholic fatty liver disease, may also affect bone mineral acquisition, especially during the adolescent years when rapid increases in bone contribute to attaining peak bone mass. Further, numerous pediatric health conditions are associated with excess adiposity, altered body composition, or endocrine disturbances that can affect bone accretion. Thus, there is a multitude of reasons for considering clinical assessment of bone health in an obese child. Multiple diagnostic challenges affect the measurement of bone density and its interpretation. These include greater precision error, difficulty in positioning, and the effects of increased lean and fat tissue on bone health outcomes. Future research is required to address these issues to improve bone health assessment in obese children.
- Published
- 2017
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11. Increased Non-High-Density Lipoprotein Cholesterol in Children and Young Adults with Turner Syndrome Is Not Explained By BMI Alone.
- Author
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Kelley JC, Gutmark-Little I, Backeljauw P, and Bamba V
- Subjects
- Adolescent, Body Composition, Child, Cross-Sectional Studies, Female, Humans, Nutrition Surveys, Retrospective Studies, Body Mass Index, Cholesterol blood, Lipoproteins blood, Turner Syndrome blood
- Abstract
Background: Turner syndrome (TS) is associated with an increased risk of cardiovascular disease. Non-high-density lipoprotein cholesterol (non-HDL-C) is a convenient measure of atherogenicity (normal concentration <120 mg/dL) but has not been investigated in TS. We aim to evaluate non-HDL-C patterns in a cohort of pediatric and young adult females with TS., Methods: A retrospective chart review was used to obtain demographics, body composition, genetic reports, and lipid profiles in females with TS., Results: Lipid profiles were assessed in 158 females (mean age 13.6 years). Mean non-HDL-C was 118.9 mg/dL (±32.0); the prevalence of high non-HDL-C (≥144 mg/dL) was 17.7% (n = 28). In TS females aged 8-17 years (n = 46), the prevalence of high non-HDL-C was 23.9% (95% CI 11.1-36.7; n = 11) between 2011 and 2012, compared to 9.2% (95% CI 5.6-14.1) in females of the same age in the general population reported in the National Health and Nutrition Examination Survey (NHANES) dataset (p < 0.005). Body mass index (BMI) accounted for only 6% of variance in non-HDL-C values (β coefficient = 1.31, p < 0.05)., Conclusions: Children and adolescents aged 8-17 years with TS appear to have a greater prevalence of adverse non-HDL-C levels compared to the general adolescent population. The prevalence of high non-HDL-C was not fully explained by BMI., (© 2017 S. Karger AG, Basel.)
- Published
- 2017
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12. TeamSTEPPS Improves Operating Room Efficiency and Patient Safety.
- Author
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Weld LR, Stringer MT, Ebertowski JS, Baumgartner TS, Kasprenski MC, Kelley JC, Cho DS, Tieva EA, and Novak TE
- Subjects
- Checklist, Humans, Operating Rooms methods, Operating Rooms organization & administration, Operative Time, Quality of Health Care organization & administration, Quality of Health Care standards, Surgical Procedures, Operative methods, Surgical Procedures, Operative standards, Efficiency, Organizational standards, Operating Rooms standards, Patient Safety standards, Quality Improvement organization & administration
- Abstract
The objective was to evaluate the effect of TeamSTEPPS on operating room efficiency and patient safety. TeamSTEPPS consisted of briefings attended by all health care personnel assigned to the specific operating room to discuss issues unique to each case scheduled for that day. The operative times, on-time start rates, and turnover times of all cases performed by the urology service during the initial year with TeamSTEPPS were compared to the prior year. Patient safety issues identified during postoperative briefings were analyzed. The mean case time was 12.7 minutes less with TeamSTEPPS (P < .001). The on-time first-start rate improved by 21% with TeamSTEPPS (P < .001). The mean room turnover time did not change. Patient safety issues declined from an initial rate of 16% to 6% at midyear and remained stable (P < 0.001). TeamSTEPPS was associated with improved operating room efficiency and diminished patient safety issues in the operating room., (© The Author(s) 2015.)
- Published
- 2016
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13. Sonographic Renal Parenchymal Measurements for the Evaluation and Management of Ureteropelvic Junction Obstruction in Children.
- Author
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Kelley JC, White JT, Goetz JT, Romero E, Leslie JA, and Prieto JC
- Abstract
Purpose: To correlate sonographic renal parenchymal measurements among patients with ureteropelvic junction obstruction (UPJO) labeled society of fetal urology (SFU) hydronephrosis grades 1-4 and to examine whether sonographic renal parenchymal measurements could be used to differentiate conservative vs. surgical management., Materials and Methods: Retrospective chart review and sonographic renal parenchymal measurements (renal length, medullary pyramid thickness, and renal parenchymal thickness) were performed in patients with SFU grades 1-4 hydronephrosis secondary to UPJO managed between 2009 and 2014. Exclusion criteria included other concomitant genitourinary pathology or incomplete follow-up. Anterior-posterior renal pelvic diameter (APRPD) and radionuclide renography were also evaluated when available., Results: One hundred four patients with UPJO underwent 244 renal and bladder ultrasound (1,464 sonographic renal parenchymal measurements in 488 kidneys). Medullary pyramid thickness and renal parenchymal thickness progressively decreased from SFU grades 1-4 (p < 0.05). A similar trend was appreciated when comparing SFU grades 1 and 2 vs. 3 and 4, as well as SFU grades 3 vs. 4 (p < 0.05). SFU grade 3 and 4 patients who underwent pyeloplasty had longer renal length in comparison to those who were managed conservatively (p < 0.02)., Conclusion: This is the first study that evaluates these objective, quantifiable sonographic renal parenchymal measurements in children with unilateral UPJO. These sonographic renal parenchymal measurements correlate closely with worsening of hydronephrosis graded by the SFU and APRPD classification systems. Prospective studies are needed to elucidate the role of sonographic renal parenchymal measurements in the management of children with UPJO.
- Published
- 2016
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14. Subunit-dependent block by isoflurane of wild-type and mutant alpha(1)S270H GABA(A) receptor currents in Xenopus oocytes.
- Author
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Hall AC, Stevens RJ, Betts BA, Yeung WY, Kelley JC, and Harrison NL
- Subjects
- Animals, Bicuculline pharmacology, Dose-Response Relationship, Drug, Excitatory Postsynaptic Potentials drug effects, Excitatory Postsynaptic Potentials physiology, GABA Antagonists pharmacology, Membrane Potentials physiology, Mutation, Oocytes drug effects, Patch-Clamp Techniques, Picrotoxin pharmacology, Protein Subunits metabolism, Receptors, GABA-A genetics, Receptors, GABA-A metabolism, Recombinant Proteins drug effects, Substrate Specificity, Xenopus, Anesthetics, Inhalation pharmacology, Isoflurane pharmacology, Membrane Potentials drug effects, Protein Subunits drug effects, Receptors, GABA-A drug effects
- Abstract
The volatile anesthetic isoflurane both prolongs and reduces the amplitude of GABA-mediated inhibitory postsynaptic currents (IPSCs) recorded in neurons. To explore the latter effect, we investigated isoflurane-induced inhibition of steady-state desensitized GABA currents in Xenopus oocytes expressing wild-type alpha(1)beta(2), alpha(1)beta(2)gamma(2s), mutant alpha(1)(S270H)beta(2) (serine to histidine at residue 270) or alpha(1)(S270H)beta(2)gamma(2s) receptors. The alpha(1) serine 270 site in TM2 (second transmembrane domain of the subunit) is postulated as a binding site for some volatile agents and is critical for positive modulation of sub-maximal GABA responses by isoflurane. For all receptor combinations, at < or =0.6 mM isoflurane (< or =2 minimum alveolar concentration (MAC)) current inhibitions were not pronounced ( approximately 10%) with block reaching half-maximal levels at supraclinical concentrations ( approximately 2 mM isoflurane, 6 MAC). Comparisons with other GABA(A) receptor blockers indicated that isoflurane blocks in a similar manner to picrotoxin, possibly via the pore of the receptor. The extent of isoflurane-induced inhibition was significantly attenuated by inclusion of the gamma(2s)-subunit but was unaffected by introduction of the S270H mutation in the alpha(1)-subunit. In conclusion, isoflurane binds with low affinity and with subunit-specificity to an inhibitory site on the GABA(A) receptor that is distinct from the site that facilitates positive modulation at the extracellular end of the pore.
- Published
- 2005
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15. The effects of isoflurane on desensitized wild-type and alpha 1(S270H) gamma-aminobutyric acid type A receptors.
- Author
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Hall AC, Rowan KC, Stevens RJ, Kelley JC, and Harrison NL
- Subjects
- Animals, DNA, Complementary drug effects, DNA, Complementary genetics, Dose-Response Relationship, Drug, Humans, Kinetics, Mutation genetics, Mutation physiology, Oocytes metabolism, Xenopus, Anesthetics, Inhalation pharmacology, Isoflurane pharmacology, Receptors, GABA-A drug effects, Receptors, GABA-A genetics
- Abstract
Unlabelled: gamma-aminobutyric acid type A receptors (GABA(A)-R) mediate synaptic inhibition and meet many pharmacological criteria required of important general anesthetic targets. During synaptic transmission GABA release is sufficient to saturate, maximally activate, and transiently desensitize postsynaptic GABA(A)-Rs. The resulting inhibitory postsynaptic currents (IPSCs) are prolonged by volatile anesthetics like isoflurane. We investigated the effects of isoflurane on maximally activated and desensitized GABA(A)-R currents expressed in Xenopus oocytes. Wild-type alpha(1)beta(2) and alpha(1)beta(2)gamma(2s) receptors were exposed to 600 microM GABA until currents reached a steady-state desensitized level. At clinical concentrations (0.02-0.3 mM), isoflurane produced a dose-dependent enhancement of steady-state desensitized current in alpha(1)beta(2) receptors, an effect that was less apparent in receptors including a gamma(2s)-subunit. When serine at position 270 is mutated to histidine (alpha(1)(S270H)) in the second transmembrane segment of the alpha(1)-subunit, the currents evoked by sub-saturating concentrations of GABA became less sensitive to isoflurane enhancement. In addition, isoflurane enhancements of desensitized currents were greatly attenuated by this mutation and were undetectable in alpha(1)(S270H)beta(2)gamma(2s) receptors. In conclusion, isoflurane enhancement of GABA(A)-R currents evoked by saturating concentrations of agonist is subunit-dependent. The effects of isoflurane on desensitized receptors may be partly responsible for the prolongation of IPSCs during anesthesia., Implications: Isoflurane enhances desensitized gamma-aminobutyric acid type A receptor (GABA(A)-R) currents, an effect that is subunit-dependent and attenuated by a mutation in an alpha(1)-subunit pore residue of the GABA(A)-R. As GABA release at inhibitory synapses is typically saturating, isoflurane modulation of desensitized receptors may be partly responsible for prolongation of inhibitory postsynaptic currents during anesthesia.
- Published
- 2004
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16. Coupling of agonist binding to channel gating in the GABA(A) receptor.
- Author
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Kash TL, Jenkins A, Kelley JC, Trudell JR, and Harrison NL
- Subjects
- Binding Sites, Cell Line, Cysteine metabolism, Disulfides metabolism, Electrophysiology, Humans, Hydrophobic and Hydrophilic Interactions, Ligands, Models, Molecular, Mutation genetics, Protein Conformation, Receptors, GABA-A chemistry, Receptors, GABA-A genetics, Static Electricity, GABA-A Receptor Agonists, Ion Channel Gating, Receptors, GABA-A metabolism
- Abstract
Neurotransmitters such as acetylcholine and GABA (gamma-aminobutyric acid) mediate rapid synaptic transmission by activating receptors belonging to the gene superfamily of ligand-gated ion channels (LGICs). These channels are pentameric proteins that function as signal transducers, converting chemical messages into electrical signals. Neurotransmitters activate LGICs by interacting with a ligand-binding site, triggering a conformational change in the protein that results in the opening of an ion channel. This process, which is known as 'gating', occurs rapidly and reversibly, but the molecular rearrangements involved are not well understood. Here we show that optimal gating in the GABA(A) receptor, a member of the LGIC superfamily, is dependent on electrostatic interactions between the negatively charged Asp 57 and Asp 149 residues in extracellular loops 2 and 7, and the positively charged Lys 279 residue in the transmembrane 2-3 linker region of the alpha1-subunit. During gating, Asp 149 and Lys 279 seem to move closer to one another, providing a potential mechanism for the coupling of ligand binding to opening of the ion channel.
- Published
- 2003
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17. A new world culture.
- Author
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Kelley JC
- Published
- 1976
- Full Text
- View/download PDF
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