69 results on '"Stevens RB"'
Search Results
2. Uric Acid: Is It an Independent Risk Factor for Cardiovascular Disease in Diabetic and Non-Diabetic Recipients after Kidney Transplant?.
- Author
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Mukherjee, U, primary, Groggel, GC, additional, Witte, JM, additional, Hudson, TL, additional, Clure, CE, additional, Lyden, ER, additional, Yu, F, additional, Stevens, RB, additional, and Larsen, JL, additional
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- 2010
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3. Unverifiable Academic Work by Applicants to Primary Care Sports Medicine Fellowship Programs in the United States.
- Author
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Stevens RB, Hatzenbuehler JR, Dexter WW, Haskins AE, and Holt CT
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- Deception, Humans, Retrospective Studies, United States, Fellowships and Scholarships, Primary Health Care, Publications, Sports Medicine education
- Abstract
Background: In 2008, it was shown that 11% of applications to a primary care sports medicine program contained unverifiable citations for publications. In 2009, the American Medical Society for Sports Medicine changed the application requirements, requiring proof that all claimed citations (publications and presentations) be included with the fellowship application., Objective: We determined the rate of unverifiable academic citations in applications to primary care sports medicine fellowship programs after proof of citations was required., Methods: We retrospectively examined all applications submitted to 5 primary care sports medicine fellowship programs across the country for 3 academic years (2010-2013), out of 108 to 131 programs per year. For claimed citations that did not include proof of publication or presentation, we attempted to verify them using PubMed and Google Scholar searches, a medical librarian search, and finally directly contacting the publisher or sponsoring conference organization for verification., Results: Fifteen of 311 applications contained at least 1 unverifiable citation. The total unverifiable rate was 4.8% (15 of 311) for publications and 11% (9 of 85) for presentations. These rates were lower than previously published within the same medical subspecialty., Conclusions: After requiring proof of publication and presentation citations within applications to primary care sports medicine fellowship programs, unverifiable citations persisted but were less than previously reported., Competing Interests: The authors declare they have no competing interests.
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- 2016
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4. A Double-Blind, Double-Dummy, Flexible-Design Randomized Multicenter Trial: Early Safety of Single- Versus Divided-Dose Rabbit Anti-Thymocyte Globulin Induction in Renal Transplantation.
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Stevens RB, Wrenshall LE, Miles CD, Farney AC, Jie T, Sandoz JP, Rigley TH, and Osama Gaber A
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- Adult, Animals, Double-Blind Method, Female, Glomerular Filtration Rate, Graft Rejection etiology, Humans, Male, Middle Aged, Prospective Studies, Rabbits, Treatment Outcome, Antilymphocyte Serum administration & dosage, Graft Rejection drug therapy, Graft Survival drug effects, Immunosuppressive Agents administration & dosage, Kidney Transplantation adverse effects
- Abstract
A previous nonblinded, randomized, single-center renal transplantation trial of single-dose rabbit anti-thymocyte globulin induction (SD-rATG) showed improved efficacy compared with conventional divided-dose (DD-rATG) administration. The present multicenter, double-blind/double-dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD-rATG versus DD-rATG induction for noninferiority in early (7-day) safety and tolerability. Ninety-five patients (randomized 1:1) received 6 mg/kg SD-rATG or 1.5 mg/kg/dose DD-rATG, with tacrolimus-mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12-month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD-rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD-rATG induction to be noninferior to DD-rATG induction in early tolerability and equivalent in 12-month safety. (Clinical Trials.gov #NCT00906204.)., (© Copyright 2016 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of the American Society of Transplantation and the American Society of Transplant Surgeons.)
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- 2016
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5. A Randomized 2x2 Factorial Clinical Trial of Renal Transplantation: Steroid-Free Maintenance Immunosuppression with Calcineurin Inhibitor Withdrawal after Six Months Associates with Improved Renal Function and Reduced Chronic Histopathology.
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Stevens RB, Foster KW, Miles CD, Kalil AC, Florescu DF, Sandoz JP, Rigley TH, Malik T, and Wrenshall LE
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- Adolescent, Adult, Aged, Animals, Antilymphocyte Serum chemistry, Biopsy, Drug Administration Schedule, Female, Graft Rejection prevention & control, Humans, Male, Middle Aged, Mycophenolic Acid administration & dosage, Mycophenolic Acid analogs & derivatives, Prospective Studies, Rabbits, Sirolimus administration & dosage, Tacrolimus administration & dosage, Time Factors, Young Adult, Calcineurin Inhibitors administration & dosage, Immunosuppression Therapy methods, Immunosuppressive Agents administration & dosage, Kidney drug effects, Kidney Transplantation, Steroids administration & dosage
- Abstract
Introduction: The two most significant impediments to renal allograft survival are rejection and the direct nephrotoxicity of the immunosuppressant drugs required to prevent it. Calcineurin inhibitors (CNI), a mainstay of most immunosuppression regimens, are particularly nephrotoxic. Until less toxic antirejection agents become available, the only option is to optimize our use of those at hand., Aim: To determine whether intensive rabbit anti-thymocyte globulin (rATG) induction followed by CNI withdrawal would individually or combined improve graft function and reduce graft chronic histopathology-surrogates for graft and, therefore, patient survival. As previously reported, a single large rATG dose over 24 hours was well-tolerated and associated with better renal function, fewer infections, and improved patient survival. Here we report testing whether complete CNI discontinuation would improve renal function and decrease graft pathology., Methods: Between April 20, 2004 and 4-14-2009 we conducted a prospective, randomized, non-blinded renal transplantation trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment = 180). Subsequent maintenance immunosuppression consisted of tacrolimus, a CNI, and sirolimus, a mammalian target of rapamycin inhibitor. We report here the outcome of converting patients after six months either to minimized tacrolimus/sirolimus or mycophenolate mofetil/sirolimus. Primary endpoints were graft function and chronic histopathology from protocol kidney biopsies at 12 and 24 months., Results: CNI withdrawal (on-treatment analysis) associated with better graft function (p <0.001) and lower chronic histopathology composite scores in protocol biopsies at 12 (p = 0.003) and 24 (p = 0.013) months, without affecting patient (p = 0.81) or graft (p = 0.93) survival, or rejection rate (p = 0.17)., Conclusion: CNI (tacrolimus) withdrawal at six months may provide a strategy for decreased nephrotoxicity and improved long-term function in steroid-free low immunological risk renal transplant patients., Trial Registration: ClinicalTrials.gov NCT00556933.
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- 2015
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6. A randomized 2×2 factorial trial, part 1: single-dose rabbit antithymocyte globulin induction may improve renal transplantation outcomes.
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Stevens RB, Foster KW, Miles CD, Lane JT, Kalil AC, Florescu DF, Sandoz JP, Rigley TH, Nielsen KJ, Skorupa JY, Kellogg AM, Malik T, and Wrenshall LE
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- Adult, Animals, Antilymphocyte Serum adverse effects, Drug Administration Schedule, Drug Therapy, Combination, Female, Graft Rejection diagnosis, Graft Rejection immunology, Graft Rejection mortality, Humans, Immunosuppressive Agents adverse effects, Kaplan-Meier Estimate, Kidney Transplantation mortality, Male, Middle Aged, Multivariate Analysis, Mycophenolic Acid administration & dosage, Mycophenolic Acid analogs & derivatives, Proportional Hazards Models, Rabbits, Risk Factors, Sirolimus administration & dosage, Steroids administration & dosage, Tacrolimus administration & dosage, Time Factors, Treatment Outcome, Antilymphocyte Serum administration & dosage, Graft Rejection prevention & control, Graft Survival drug effects, Immunosuppressive Agents administration & dosage, Kidney Transplantation adverse effects
- Abstract
Background: We conducted a randomized and unblinded 2 × 2 sequential-factorial trial, composed of an induction arm (part 1) comparing single-dose (SD) versus divided-dose rabbit antithymocyte globulin (rATG), and a maintenance arm (part 2) comparing tacrolimus minimization versus withdrawal. We report the long-term safety and efficacy of SD-rATG induction in the context of early steroid withdrawal and tacrolimus minimization or withdrawal., Methods: Patients (n=180) received 6 mg/kg rATG, SD or four alternate-day doses (1.5 mg/kg/dose), with early steroid withdrawal and tacrolimus or sirolimus maintenance. After 6 months targeted maintenance levels were tacrolimus, 2 to 4 ng/mL and sirolimus, 4 to 6 ng/mL or, if calcineurin inhibitor-withdrawn, sirolimus 8 to 12 ng/mL with mycophenolate mofetil 2 g two times per day. Primary endpoints were renal function (abbreviated modification of diet in renal disease) and chronic graft histopathology (Banff). Secondary endpoints included patient survival, graft survival, biopsy-proven rejection, and infectious or noninfectious complications., Results: Follow-up averaged longer than 4 years. Tacrolimus or sirolimus and mycophenolate mofetil exposure was identical between groups. The SD-rATG associated with improved renal function (2-36 months; P<0.001) in deceased donor recipients. The SD-rATG associated with quicker lymphocyte, CD4 T cell, and CD4-CD8 recovery and fewer infections. Cox multivariate hazard modeling showed divided-dose-rATG (P=0.019), deceased donor (P=0.003), serious infection (P=0.0.018), and lower lymphocyte count (P=0.001) associated with increased mortality. Patients with all four covariates showed a 27-fold increased likelihood of death (P=0.00002). Chronic graft histopathology, rejection rates, and death-censored graft survival were not significantly different between groups., Conclusion: The SD-rATG induction improves the 3-year renal function in recipients of deceased donor kidneys. This benefit, along with possibly improved patient survival and fewer infections suggest that how rATG is administered may impact its efficacy and safety.
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- 2015
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7. Risk of serious opportunistic infections after solid organ transplantation: interleukin-2 receptor antagonists versus polyclonal antibodies. A meta-analysis.
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Kalil AC, Florescu MC, Grant W, Miles C, Morris M, Stevens RB, Langnas AN, and Florescu DF
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- Graft Rejection epidemiology, Humans, Opportunistic Infections epidemiology, Randomized Controlled Trials as Topic, Risk Assessment, Transplantation Immunology, Antibodies therapeutic use, Immunosuppressive Agents therapeutic use, Opportunistic Infections complications, Organ Transplantation, Postoperative Complications microbiology, Receptors, Interleukin-2 antagonists & inhibitors
- Abstract
Background: We aimed to evaluate and quantify the risk of serious opportunistic infections after induction with polyclonal antibodies versus IL-2 receptor antagonists (IL-2RAs) in randomized clinical trials., Methods: PRISMA guidelines were followed and random-effects models were performed., Results: 70 randomized clinical trials (10,106 patients) were selected: 36 polyclonal antibodies (n = 3377), and 34 IL-2RAs (n = 6729). Compared to controls, polyclonal antibodies showed higher risk of serious opportunistic infections (OR: 1.93, 95% CI: 1.34-2.80; p < 0.0001); IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.80, 95% CI: 0.68-0.94; p = 0.009). Polyclonal antibodies were associated with higher risk of bacterial (OR: 1.58, 95% CI: 1.00-2.50; p = 0.049) and viral infections (OR: 2.37, 95% CI: 1.60-3.49; p < 0.0001), while IL-2RAs were associated with lower risk of cytomegalovirus (CMV) disease (OR: 0.73, 95% CI: 0.56-0.97; p = 0.032). Adjusted indirect comparison: compared to polyclonal antibodies, IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.41, 95% CI: 0.34-0.49; p < 0.0001), bacterial infections (OR: 0.51, 95% CI: 0.39-0.67; p < 0.0001) and CMV disease (OR: 0.58, 95% CI: 0.34-0.98; p = 0.043). Results remained consistent across allografts., Conclusion: The risk of serious opportunistic infections, bacterial infections and CMV disease were all significantly decreased with IL-2RAs compared to polyclonal antibodies.
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- 2014
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8. Antithymocyte globulin induction in living donor renal transplant recipients: final report of the TAILOR registry.
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Gaber AO, Matas AJ, Henry ML, Brennan DC, Stevens RB, Kapur S, Ilsley JN, Kistler KD, and Cosimi AB
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- Adult, Animals, Antilymphocyte Serum adverse effects, Antiviral Agents therapeutic use, Creatinine blood, Female, Graft Survival, Humans, Male, Middle Aged, Rabbits, Registries, Antilymphocyte Serum therapeutic use, Immunosuppressive Agents therapeutic use, Kidney Transplantation, Living Donors
- Abstract
Background: The Thymoglobulin Antibody Immunosuppression in Living Donor Recipients registry was established to assess clinical experience with rabbit antithymocyte globulin (rATG; Thymoglobulin) in living donor renal transplant recipients., Methods: From 2003 to 2008, US transplant centers prospectively entered information on patients who received rATG induction. In addition to standard United Network for Organ Sharing registry data elements, information was collected regarding immunosuppression, viral prophylaxis, acute rejection, and adverse events., Results: Data on 2322 patients from 49 transplant centers were enrolled and met inclusion criteria for analysis. Patient and graft survival were 99.3% and 99.0% at 6 months and 98.4% and 98.2% at 12 months as recorded in Thymoglobulin Antibody Immunosuppression in Living Donor Recipients registry and were 91.5% and 83.2% at 5 years by Kaplan-Meier estimates based on linked United Network for Organ Sharing registry records. Freedom from rejection was 93.6% through 5 years. Mean rATG cumulative dose was 5.29 mg/kg. More than one-third of patients (37.6%) were steroid-free at discharge, and nearly half of patients (48%) were steroid-free at 12 months. Before discharge, 3.2% experienced serious adverse events, with 11 events (0.005%) reported as possibly or probably related to rATG. Incidence of cytomegalovirus infection was 4.2% at 12 months, and 99.1% of patients were posttransplant lymphoproliferative disorder-free through 5 years., Conclusions: rATG induction in living donor renal transplantation is safe and associated with a low incidence of acute rejection and posttransplantation complications.
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- 2012
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9. Interleukin-2 is present in human blood vessels and released in biologically active form by heparanase.
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Miller JD, Clabaugh SE, Smith DR, Stevens RB, and Wrenshall LE
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- Animals, Aortic Aneurysm metabolism, Arteries cytology, Arteries metabolism, Cells, Cultured, Endothelial Cells metabolism, Extracellular Matrix Proteins metabolism, Heparan Sulfate Proteoglycans metabolism, Humans, Mice, Mice, Knockout, Receptors, Interleukin-2 metabolism, Endothelium, Vascular metabolism, Glucuronidase metabolism, Interleukin-2 metabolism, Muscle, Smooth, Vascular metabolism
- Abstract
Interleukin-2 (IL-2) is a multifaceted cytokine with immunostimulatory and immunosuppressive properties. Our laboratory recently demonstrated that the availability of IL-2 is regulated, in part, by association with perlecan, a heparan sulfate proteoglycan. Given the abundance of perlecan in blood vessels, we asked whether IL-2 is present in vessel walls. Our results indicate that IL-2 is associated with endothelial and smooth muscle cells within the human arterial wall. This IL-2 is released by heparanase, and promotes the proliferation of an IL-2-dependent cell line. Given the presence of IL-2 in human arteries, we asked whether the large vessels of IL-2-deficient mice were normal. The aortas of IL-2-deficient mice exhibited a loss of smooth muscle cells, suggesting that IL-2 may contribute to their survival. In their entirety, these results suggest a here-to-fore unrecognized role of IL-2 in vascular biology, and have significant implications for both the immune and cardiovascular systems.
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- 2012
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10. Single-dose rATG induction at renal transplantation: superior renal function and glucoregulation with less hypomagnesemia.
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Stevens RB, Lane JT, Boerner BP, Miles CD, Rigley TH, Sandoz JP, Nielsen KJ, Skorupa JY, Skorupa AJ, Kaplan B, and Wrenshall LE
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- Adult, Aged, Animals, Diabetes Mellitus etiology, Female, Follow-Up Studies, Humans, Hyperglycemia etiology, Immunosuppressive Agents therapeutic use, Kidney Function Tests, Male, Middle Aged, Prognosis, Prospective Studies, Rabbits, Renal Tubular Transport, Inborn Errors etiology, Survival Rate, Young Adult, Antilymphocyte Serum administration & dosage, Blood Glucose metabolism, Diabetes Mellitus prevention & control, Graft Rejection prevention & control, Hyperglycemia prevention & control, Kidney Transplantation, Renal Tubular Transport, Inborn Errors prevention & control
- Abstract
Background: Rabbit anti-thymocyte globulin (rATG) induction reduces reperfusion injury and improves renal function in kidney recipients by means of properties unrelated to T-cell lysis. Here, we analyze intensive rATG induction (single dose, rATG(S) , vs. divided dose, rATG(D) ) for improved renal function and protection against hyperglycemia., Methods: Patients without diabetes (n = 98 of 180) in a prospective randomized trial of intensive rATG induction were followed for six months for the major secondary composite end point of impaired glucose regulation (hyperglycemia and new-onset diabetes after transplantation, NODAT). Prospectively collected data included fasting blood glucose and HbA(1c). Serum Mg(++) was routinely collected and retrospectively analyzed., Results: Induction with rATG(S) produced less impaired glucose regulation (p = 0.05), delayed NODAT development (p = 0.02), less hyperglycemia (p = 0.02), better renal function (p = 0.04), and less hypomagnesemia (p = 0.02), a factor associated with a lower incidence of NODAT. Generalized linear modeling confirmed that rATG(S) protects against a synergistic interaction between tacrolimus and sirolimus that otherwise increased hypomagnesemia (p = 0.008) and hyperglycemia (p = 0.03)., Conclusions: rATG(S) initiated before renal reperfusion improved early renal function and reduced impaired glucose regulation, an injury by diabetogenic maintenance agents (tacrolimus and sirolimus)., (© 2011 John Wiley & Sons A/S.)
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- 2012
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11. Loss of renal allografts secondary to Candida vascular complications in two recipients from the same donor.
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Yannam GR, Wrenshall L, and Stevens RB
- Abstract
Infections remain a major cause of morbidity and mortality in transplant patients. Organ recipients are also susceptible to donor-derived pathogens and the majority of donor infections are easily treatable. Rarely, some pathogens have produced life-threatening complications by compromising the vascular anastomosis. In this case series we report loss of two kidney allografts secondary to vascular complications due to Candida albicans. Both recipients received grafts from a common donor, in whom Candida bacteremia in the donor was not apparent at the time of organ acceptance but became apparent on delayed cultures.
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- 2012
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12. Walkable new urban LEED_Neighborhood-Development (LEED-ND) community design and children's physical activity: selection, environmental, or catalyst effects?
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Stevens RB and Brown BB
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- Child, Female, Humans, Male, Schools, Transportation methods, Walking, Child Welfare, Environment, Exercise, Residence Characteristics, Social Change, Urban Population
- Abstract
Background: Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development) community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA) across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends., Methods: Fifth graders (n = 187) were sampled from two schools representing three communities: (1) a walkable community, Daybreak, designed with new urbanist and LEED-ND pilot design standards; (2) a mixed community (where students lived in a less walkable community but attended the walkable school so that part of the route to school was walkable), and (3) a less walkable community. Selection threats were addressed through controlling for parental preferences for their child to walk to school as well as comparing in-school MVPA for the walkable and mixed groups., Results: Minutes of MVPA were tested with 3 × 2 (Community by Gender) analyses of covariance (ANCOVAs). Community walkability related to more MVPA during the half hour before and after school and, among boys only, more MVPA after school. Boys were more active than girls, except during the half hour after school. Students from the mixed and walkable communities--who attended the same school--had similar in-school MVPA levels, and community groups did not differ in weekend MVPA, providing little evidence of selection effects., Conclusions: Even after our controls for selection effects, we find evidence of environmental effects on MVPA. These results suggest that walkable community design, according to new urbanist and LEED_ND pilot design standards, is related to higher MVPA among students at certain times.
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- 2011
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13. Sitagliptin therapy in kidney transplant recipients with new-onset diabetes after transplantation.
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Lane JT, Odegaard DE, Haire CE, Collier DS, Wrenshall LE, and Stevens RB
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- Female, Glomerular Filtration Rate, Glycated Hemoglobin analysis, Humans, Male, Middle Aged, Pyrazines adverse effects, Sitagliptin Phosphate, Triazoles adverse effects, Diabetes Mellitus drug therapy, Dipeptidyl-Peptidase IV Inhibitors therapeutic use, Kidney Transplantation adverse effects, Pyrazines therapeutic use, Triazoles therapeutic use
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- 2011
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14. Albuminuria after renal transplantation: maintenance with sirolimus/low-dose tacrolimus vs. mycophenolate mofetil/high-dose tacrolimus.
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Miles CD, Skorupa JY, Sandoz JP, Rigley TH, Nielsen KJ, and Stevens RB
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- Adult, Albuminuria etiology, Case-Control Studies, Dose-Response Relationship, Drug, Female, Follow-Up Studies, Humans, Kidney Transplantation mortality, Male, Middle Aged, Mycophenolic Acid administration & dosage, Prognosis, Retrospective Studies, Survival Rate, Albuminuria drug therapy, Graft Rejection prevention & control, Immunosuppressive Agents administration & dosage, Kidney Transplantation adverse effects, Mycophenolic Acid analogs & derivatives, Sirolimus administration & dosage, Tacrolimus administration & dosage
- Abstract
Maintenance immunosuppression with sirolimus (SRL) in renal transplantation has been associated with proteinuria. We report long-term outcomes of kidney transplant recipients maintained on steroid-free regimens, either SRL with low-dose tacrolimus (SRL/L-Tac) or mycophenolate mofetil (MMF) with high-dose tacrolimus (MMF/H-Tac). We conducted a case-matched study of 50 patients receiving MMF/H-Tac, matched 1:2 with 100 patients maintained on SRL/L-Tac. All patients were induced with rabbit antithymocyte globulin followed by early steroid withdrawal. Comparisons were made of patient and graft survival, graft function, acute rejection, and albuminuria. There were no significant differences between the SRL/L-Tac and MMF/H-Tac groups for patient survival, graft survival, occurrence of acute rejection, or graft function. There was no difference in the proportion of patients with albumin/creatinine ratio (ACR) ≥300 μg/mg (19% vs. 20%), but more patients in the SRL group were receiving renin-angiotensin system blocking agents (72% vs. 53%, p = 0.04). Only flushing the donor kidney with histidine-tryptophan-ketoglutarate solution (vs. UW solution) was predictive of albuminuria. Long-term outcomes are similar at our center for kidney transplant patients receiving either SRL/L-Tac or MMF/H-Tac. Although the occurrence of albuminuria was not different, significantly more SRL-treated patients were receiving antiproteinuric medications., (© 2010 John Wiley & Sons A/S.)
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- 2011
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15. Time use choices and healthy body weight: a multivariate analysis of data from the American Time Use Survey.
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Zick CD, Stevens RB, and Bryant WK
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- Adult, Body Composition, Body Mass Index, Cross-Sectional Studies, Energy Intake, Female, Food, Food Preferences, Health Behavior, Humans, Income, Male, Middle Aged, Motor Activity, Multivariate Analysis, Nutrition Surveys methods, Obesity epidemiology, Risk Factors, Socioeconomic Factors, Television, United States, Body Weight, Choice Behavior, Feeding Behavior
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Background: We examine the relationship between time use choices and healthy body weight as measured by survey respondents' body mass index (BMI). Using data from the 2006 and 2007 American Time Use Surveys, we expand upon earlier research by including more detailed measures of time spent eating as well as measures of physical activity time and sedentary time. We also estimate three alternative models that relate time use to BMI., Results: Our results suggest that time use and BMI are simultaneously determined. The preferred empirical model reveals evidence of an inverse relationship between time spent eating and BMI for women and men. In contrast, time spent drinking beverages while simultaneously doing other things and time spent watching television/videos are positively linked to BMI. For women only, time spent in food preparation and clean-up is inversely related to BMI while for men only, time spent sleeping is inversely related to BMI. Models that include grocery prices, opportunity costs of time, and nonwage income reveal that as these economic variables increase, BMI declines., Conclusions: In this large, nationally representative data set, our analyses that correct for time use endogeneity reveal that the Americans' time use decisions have implications for their BMI. The analyses suggest that both eating time and context (i.e., while doing other tasks simultaneously) matters as does time spent in food preparation, and time spent in sedentary activities. Reduced form models suggest that shifts in grocery prices, opportunity costs of time, and nonwage income may be contributing to alterations in time use patterns and food choices that have implications for BMI.
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- 2011
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16. Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?
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Ichim TE, Minev B, Braciak T, Luna B, Hunninghake R, Mikirova NA, Jackson JA, Gonzalez MJ, Miranda-Massari JR, Alexandrescu DT, Dasanu CA, Bogin V, Ancans J, Stevens RB, Markosian B, Koropatnick J, Chen CS, and Riordan NH
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- Ascorbic Acid pharmacology, Ascorbic Acid Deficiency complications, Endothelium drug effects, Endothelium physiopathology, Humans, Immunity drug effects, Injections, Intravenous, Sepsis etiology, Sepsis physiopathology, Ascorbic Acid administration & dosage, Ascorbic Acid therapeutic use, Neoplasms complications, Sepsis drug therapy, Sepsis prevention & control
- Abstract
The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis.
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- 2011
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17. Experience of laparoscopic incisional hernia repair in kidney and/or pancreas transplant recipients.
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Yannam GR, Gutti TL, High R, Stevens RB, Thompson JS, and Morris MC
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- Case-Control Studies, Female, Humans, Intestinal Perforation etiology, Male, Middle Aged, Postoperative Complications etiology, Recurrence, Retrospective Studies, Seroma etiology, Surgical Mesh adverse effects, Surgical Wound Infection etiology, Hernia, Abdominal etiology, Hernia, Abdominal surgery, Kidney Transplantation adverse effects, Laparoscopy adverse effects, Pancreas Transplantation adverse effects
- Abstract
Despite the wide popularity of laparoscopic incisional hernia repair (LIHR) in the nontransplant population, there are very few reports of LIHR available in abdominal organ transplant patients and none exclusively on kidney and/or pancreas (KP) transplant patients. We retrospectively reviewed a consecutive series of LIHR in KP transplant recipients performed over a period of 4 years and compared the results with LIHR in non-transplant patients during the same period. A total of 36 transplant patients were compared with 62 nontransplant patients. There were five patients converted to the open procedure in the transplant and four in nontransplant patients (p-NS). There were three seromas and one patient had a bowel perforation in the transplant group versus eight seromas, one bowel perforation and one small bowel obstruction noted in the nontransplant group. One patient in each group had a mesh infection requiring explant. Patients were followed up for a mean period of 2.2 years in the transplant group and 3 years in the nontransplant group. Overall there were five recurrences in the transplant group and four in the nontransplant group (p = NS). These results suggest that that LIHR is a safe and effective alternative to open repair., (©2011 The Authors Journal compilation©2011 The American Society of Transplantation and the American Society of Transplant Surgeons.)
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- 2011
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18. Trends in Americans' food-related time use: 1975-2006.
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Zick CD and Stevens RB
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- Adult, Energy Intake physiology, Female, Food, Humans, Leisure Activities, Male, Middle Aged, Nutrition Surveys, Obesity etiology, Time Factors, United States epidemiology, Cooking statistics & numerical data, Diet trends, Eating physiology, Obesity epidemiology
- Abstract
Objective: To describe how the time spent in food-related activities by Americans has changed over the past 30 years., Design: Data from four national time diary surveys, spanning 1975-2006, are used to construct estimates of trends in American adults' time spent in food-related activities. Multivariate Tobits assess how food-related activities have changed over time controlling for sociodemographic and economic covariates., Results: Both bivariate and multivariate estimates reveal that between 1975 and 2006, American women's time spent in food preparation declined substantially, whereas the time spent in these activities by American men changed very little. On the contrary, grocery shopping time increased modestly for both men and women. The primary eating time (i.e. time when eating/drinking was the respondent's main focus) declined for both men and women over this historical period, and the composition of this time changed with less primary eating time being done alone. Concurrently, secondary eating time (i.e. time when something else had the respondent's primary attention, but eating/drinking simultaneously occurred) rose precipitously for both women and men between 1975 and 1998., Conclusions: The total time spent in eating (i.e. primary plus secondary eating time) has increased over the past 30 years, and the composition of this time has shifted from situations in which energy intake can be easily monitored to those in which energy intake may be more difficult to gauge. Less time is also being spent in food preparation and clean-up activities. Future research should explore possible links between these trends and Americans' growing obesity risk.
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- 2010
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19. Presumptive serum sickness as a complication of rabbit-derived antithymocyte globulin immunosuppression.
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Snow MH, Cannella AC, Stevens RB, and Mikuls TR
- Subjects
- Adult, Animals, Antilymphocyte Serum therapeutic use, Graft Rejection immunology, Graft Rejection prevention & control, Humans, Immunosuppressive Agents therapeutic use, Kidney Transplantation immunology, Male, Middle Aged, Rabbits, Antilymphocyte Serum adverse effects, Immunosuppressive Agents adverse effects, Serum Sickness chemically induced, Serum Sickness diagnosis
- Published
- 2009
- Full Text
- View/download PDF
20. Successful urgent transplantation of an adult kidney into a child with inferior vena cava thrombosis.
- Author
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Stevens RB, Yannam GR, Hill BC, Rigley TH, Penn DM, and Skorupa JY
- Subjects
- Child, Preschool, Humans, Kidney pathology, Magnetic Resonance Angiography, Male, Organ Size, Radiography, Renal Veins surgery, Treatment Outcome, Vena Cava, Inferior diagnostic imaging, Kidney Transplantation, Vena Cava, Inferior surgery, Venous Thrombosis surgery
- Abstract
Poor venous drainage options following inferior vena cava (IVC) thrombosis have been considered to complicate or preclude renal transplantation of adult kidneys into pediatric patients. We describe urgent renal transplantation in a 5-year-old (15.3 kg) male with IVC thrombosis using an adult living donor. Preoperative magnetic resonance venography revealed a patent infrahepatic/suprarenal vena cava and portal system. In surgery, the right liver lobe was mobilized sufficiently to anastomose the graft renal vein to the native IVC at the confluence of the native left renal vein and proximal vena cava. Graft function has remained excellent with serum creatinine of 0.5 mg/dL at 36 months. IVC thrombosis need not preclude successful transplantation of adult-sized kidneys into children.
- Published
- 2009
- Full Text
- View/download PDF
21. Acute transverse myelitis and paralysis in a kidney-pancreas recipient.
- Author
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Stevens RB, Yannam GR, Skorupa JY, Rigley TH, Penn DM, and Wrenshall LE
- Subjects
- Adult, Diabetes Mellitus, Type 1 complications, Humans, Immunosuppressive Agents adverse effects, Immunosuppressive Agents therapeutic use, Inflammation, Magnetic Resonance Imaging methods, Male, Pancreas pathology, Renal Insufficiency therapy, T-Lymphocytes immunology, Kidney Transplantation adverse effects, Myelitis, Transverse etiology, Pancreas Transplantation adverse effects, Paralysis etiology, Postoperative Complications etiology
- Published
- 2009
- Full Text
- View/download PDF
22. Increased primary non-function in transplanted deceased-donor kidneys flushed with histidine-tryptophan-ketoglutarate solution.
- Author
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Stevens RB, Skorupa JY, Rigley TH, Yannam GR, Nielsen KJ, Schriner ME, Skorupa AJ, Murante A, Holdaway E, and Wrenshall LE
- Subjects
- Adenosine, Adult, Aged, Allopurinol, Female, Glucose adverse effects, Glutathione, Humans, Insulin, Kidney Function Tests, Male, Mannitol adverse effects, Middle Aged, Potassium Chloride adverse effects, Procaine adverse effects, Raffinose, Renal Dialysis, Cadaver, Delayed Graft Function epidemiology, Kidney Transplantation physiology, Organ Preservation Solutions adverse effects, Tissue Donors
- Abstract
Histidine-Tryptophan-Ketoglutarate (HTK) solution is increasingly used to flush and preserve organ donor kidneys, with efficacy claimed equivalent to University of Wisconsin (UW) solution. We observed and reported increased graft pancreatitis in pancreata flushed with HTK solution, which prompted this review of transplanting HTK-flushed kidneys. We analyzed outcomes of deceased-donor kidneys flushed with HTK and UW solutions with a minimum of 12 months follow-up, excluding pediatric and multi-organ recipients. We evaluated patient and graft survival and rejection rates, variables that might constitute hazards to graft survival and renal function. Two-year patient survival, rejection, renal function and graft survival were not different, but early graft loss (<6 months) was worse in HTK-flushed kidneys (p < 0.03). A Cox analysis of donor grade, cold ischemic time, panel reactive antibodies (PRA), donor race, first vs. repeat transplant, rejection and flush solution showed that only HTK use predicted early graft loss (p < 0.04; relative risk = 3.24), almost exclusively attributable to primary non-function (HTK, n = 5 (6.30%); UW, n = 1 (0.65%); p = 0.02). Delayed graft function and early graft loss with HTK occurred only in lesser grade kidneys, suggesting it should be used with caution in marginal donors.
- Published
- 2009
- Full Text
- View/download PDF
23. Modern approaches to combining sirolimus with calcineurin inhibitors.
- Author
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Stevens RB
- Subjects
- Adrenal Cortex Hormones therapeutic use, Animals, Glomerular Filtration Rate drug effects, Graft Rejection prevention & control, Graft Survival drug effects, Graft Survival immunology, Humans, Immunosuppressive Agents therapeutic use, Kidney Transplantation mortality, Prednisone therapeutic use, Probability, Rabbits, Survival Analysis, Survivors, Transplantation, Homologous immunology, Antilymphocyte Serum therapeutic use, Calcineurin Inhibitors, Graft Rejection immunology, Kidney Transplantation immunology, Sirolimus therapeutic use
- Abstract
Routine renal transplantation maintenance immunosuppression at the University of Nebraska Medical Center consists of rabbit anti-thymocyte globulin (rATG) induction with early steroid withdrawal followed by maintenance with sirolimus and tacrolimus, a regimen we have used with >900 patients. Induction consists of 6 mg/kg rATG in 4 doses of 1.5 mg/kg each on days 0, 2, 4, and 6. Prednisone is used only in association with rATG administration. Maintenance agents are introduced gradually depending on renal function. Since April 2004, we have been conducting a prospective, randomized trial of this regimen versus 2 modifications: administering the rATG induction dose (6 mg/kg) in a single infusion over 24 hours; and, after 6 months, replacing tacrolimus with mycophenolate mofetil (MMF) in half of the study subjects. This study has shown several benefits of single-dose rATG induction, including significantly improved early graft function with both living and deceased donor kidneys and improved 2- to 12-month function in deceased donor organs (P = .026). Single-dose lymphocyte counts return to baseline sooner (2.2 vs 15.3 years; P < .05) without increased rejection (1 year; 8.5% single vs 12.5% divided; P = NS), and single-dose induction reduces chronic allograft nephropathy at 1 year (P = .05). Preliminary results of replacing tacrolimus with MMF show immediately improved renal function (months 1 and 2; P = .02 and .05; months 1-6, P = .058) without increased rejection.
- Published
- 2008
- Full Text
- View/download PDF
24. Increased pancreatitis in allografts flushed with histidine-tryptophan-ketoglutarate solution: a cautionary tale.
- Author
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Alonso D, Dunn TB, Rigley T, Skorupa JY, Schriner ME, Wrenshall LE, and Stevens RB
- Subjects
- Adult, Follow-Up Studies, Glucose adverse effects, Glucose economics, Graft Survival, Humans, Mannitol adverse effects, Mannitol economics, Middle Aged, Organ Preservation Solutions economics, Pancreatitis diagnosis, Pancreatitis therapy, Potassium Chloride adverse effects, Potassium Chloride economics, Procaine adverse effects, Procaine economics, Survival Analysis, Time Factors, Transplantation, Homologous, Treatment Outcome, Organ Preservation Solutions adverse effects, Pancreas Transplantation, Pancreatitis etiology, Transplants
- Abstract
We reviewed pancreas transplantation outcomes after Histidine-Tryptophan-Ketoglutarate (HTK) and University of Wisconsin (UW) preservation solution use between 2001 and 2007 at two transplant centers. While equivalence has been claimed for kidney and liver transplant outcomes after the use of HTK or UW preservation solution, consensus has not been reached on equivalence when flushing pancreata. Others have reported comparable patient and graft survival rates, but found an association between the use of HTK and an increase in the incidence of acute rejection and pancreatitis. In reviewing our experiences, we found in pancreata flushed with HTK a higher incidence of postoperative complications including graft pancreatitis, use of octreotide and a decreased rate of insulin-independence at hospital discharge. These findings prompted us to critically review our centers' experience to determine if there is a basis for suspecting a causal relationship.
- Published
- 2008
- Full Text
- View/download PDF
25. Randomized trial of single-dose versus divided-dose rabbit anti-thymocyte globulin induction in renal transplantation: an interim report.
- Author
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Stevens RB, Mercer DF, Grant WJ, Freifeld AG, Lane JT, Groggel GC, Rigley TH, Nielsen KJ, Henning ME, Skorupa JY, Skorupa AJ, Christensen KA, Sandoz JP, Kellogg AM, Langnas AN, and Wrenshall LE
- Subjects
- Adult, Animals, Antilymphocyte Serum administration & dosage, Drug Administration Schedule, Drug Monitoring methods, Drug Therapy, Combination, Female, Glomerular Filtration Rate, Graft Survival drug effects, Humans, Kidney Transplantation adverse effects, Kidney Transplantation mortality, Male, Middle Aged, Patient Selection, Rabbits, Sirolimus therapeutic use, Survival Analysis, Tacrolimus therapeutic use, Transplantation, Homologous, Antilymphocyte Serum therapeutic use, Kidney Transplantation immunology
- Abstract
Background: The optimal dosing protocol for rabbit anti-thymocyte globulin (rATG) induction in renal transplantation has not been determined, but evidence exists that rATG infusion before renal allograft reperfusion improves early graft function. Infusing a large rATG dose over a short interval has not previously been evaluated for its effect on renal function and allograft nephropathy in a prospective, randomized comparison against conventional rATG induction., Methods: Between April 20, 2004 and December 26, 2007 we enrolled renal transplant patients into a prospective, randomized, nonblinded trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment=160) followed after 6 months by calcineurin-inhibitor withdrawal. Primary endpoints are renal function by calculated glomerular filtration rate (GFR) and chronic allograft nephropathy at protocol biopsy. We now present the early GFR data of all 160 patients and safety and efficacy data of the first 142 patients with 6 months follow up and before calcineurin inhibitor withdrawal (average follow up=23.3+/-11.6 months)., Results: There were no differences between groups in rATG-related adverse events, patient and graft survival, acute rejection, or chronic allograft nephropathy rate at 6 months. Calculated DeltaGFR (POD 1-4) was significantly better in the single-dose group (P=0.02), with a trend toward improved renal function from months 2 to 6 in recipients of deceased donor kidneys (P=0.08)., Conclusions: This study demonstrates that administering 6 mg/kg of rATG over 24 hr is safe and is associated with improved early renal function compared with administering rATG in alternate-day doses.
- Published
- 2008
- Full Text
- View/download PDF
26. Dyslipidemia can be controlled in diabetic as well as nondiabetic recipients after kidney transplant.
- Author
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Shivaswamy V, Stevens RB, Zephier R, Zephier M, Sun J, Groggel G, Erickson J, and Larsen J
- Subjects
- Adult, Diabetes Mellitus, Type 1 blood, Diabetes Mellitus, Type 1 complications, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 complications, Female, Follow-Up Studies, Humans, Immunosuppressive Agents therapeutic use, Kidney Transplantation immunology, Lipoproteins, LDL blood, Male, Middle Aged, Time Factors, Triglycerides blood, Cholesterol blood, Diabetic Nephropathies drug therapy, Diabetic Nephropathies surgery, Dyslipidemias drug therapy, Dyslipidemias etiology, Kidney Transplantation adverse effects, Lipids blood, Postoperative Complications drug therapy
- Abstract
Background: Patients with diabetes have been reported to have greater dyslipidemia after kidney transplant (KTX). Because postKTX management of diabetes has changed markedly since those reports, we hypothesized that lipids can be controlled as well in diabetic as in nondiabetic recipients., Methods: We compared lipid levels up to 2 years after KTX (n=192) between diabetic and nondiabetic recipients. The cohort was subdivided into nondiabetic (nonDM-K; n=123), type 2 (DM2-K; n=33), or type 1 diabetes after KTX (DM1-K; n=14), or type 1 after kidney-pancreas transplant (DM1-KP; n=22)., Results: Mean age and body mass index of DM2-K were greater than the others (P<0.01), and diabetes groups had a higher pretransplant A1C than nonDM-K (P<0.001). After KTX, lipid levels were not higher in diabetic than in nondiabetic recipients, and did not increase in any group. Total and low-density lipoprotein cholesterol levels decreased in DM1-K (P<0.001), high-density lipoprotein levels decreased in DM1-KP (P=0.02), and triglyceride levels were unchanged after KTX for all groups. A1C improved in DM1-K and DM1-KP (P<0.0001). There was less improvement in lipid levels with tacrolimus-sirolimus immunosuppression than with other steroid-containing regimens (P<0.05)., Conclusions: Multiple mechanisms may contribute to better lipid levels in both groups as well as the lack of difference between diabetic and nondiabetic recipients compared with what has been reported previously: greater use of and more effective lipid-lowering agents, no significant weight gain, no difference in renal function between groups, and better control of glucose in the diabetic group. Thus, overall, lipids can be controlled as well in diabetic as in nondiabetic KTX recipients.
- Published
- 2008
- Full Text
- View/download PDF
27. Hashimoto's encephalopathy after intensive lymphocyte depletion with rabbit anti-thymocyte globulin in a renal transplant patient.
- Author
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Stevens RB, Wakefield CB, Alonso D, Skorupa JY, Rigley TH, Penn DM, and Wrenshall LE
- Subjects
- Animals, Diabetes Mellitus, Type 1 complications, Diabetes Mellitus, Type 1 immunology, Diabetes Mellitus, Type 1 surgery, Diabetic Coma complications, Female, Hashimoto Disease diagnosis, Hashimoto Disease immunology, Hashimoto Disease surgery, Humans, Middle Aged, Rabbits, Antilymphocyte Serum adverse effects, Hashimoto Disease etiology, Kidney Transplantation, Lymphocyte Depletion
- Abstract
There has been no reported case of Hashimoto's encephalopathy (HE) ('steroid-responsive encephalopathy associated with autoimmune thyroiditis', 'SREAT'), in the renal transplant recipient population. We describe the case of a 55-year-old female with Type-1 diabetes who presented 2 years posttransplantation in a comatose state that had developed over the preceding 24 h. The patient had received a short, intensive course of rATG induction at the time of transplantation and early steroid withdrawal. After 6 months she had been withdrawn from calcineurin inhibitors and was maintained on mycophenolate mofetil and sirolimus. Systematic workup determined the cause of her coma to be HE. High-dose steroid therapy resulted in complete resolution of the patient's symptoms. The literature regarding the diagnosis, course and treatment of HE is reviewed and the possibility that increased use of steroid-free immunosuppression and intensive lymphocyte depletion regimens may increase the prevalence of de novo autoimmune disease is discussed.
- Published
- 2008
- Full Text
- View/download PDF
28. New-onset diabetes after kidney transplantation: an application of 2003 International Guidelines.
- Author
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Sulanc E, Lane JT, Puumala SE, Groggel GC, Wrenshall LE, and Stevens RB
- Subjects
- Adult, Cyclosporine adverse effects, Diabetes Mellitus diagnosis, Female, Graft Rejection drug therapy, Humans, Immunosuppressive Agents adverse effects, Incidence, Male, Middle Aged, Risk Factors, Sirolimus adverse effects, Tacrolimus adverse effects, Diabetes Mellitus epidemiology, Diabetes Mellitus etiology, Kidney Transplantation, Practice Guidelines as Topic
- Abstract
Background: The 2003 International Consensus Guidelines defined new-onset diabetes after transplantation. This study determined the risk of new-onset diabetes following kidney transplantation using these criteria., Methods: Consecutive nondiabetic patients who received kidney transplantation between August 2001 and March 2003 (recent, n=61) and before August 2001 (earlier, n=61) were retrospectively evaluated., Results: In all, 74% in the recent group and 56% in the earlier group developed diabetes by 1 year posttransplant. Median time to diabetes development was 23 days in the recent vs. 134 days in the earlier group (P=0.0304). Most patients developed diabetes within 60 days after transplantation. Immunosuppression was the strongest correlate of diabetes development; tacrolimus and cyclosporine A treatments were associated with increased risk. The rate of development was also greater when rapamycin was added to tacrolimus, compared to when it was not. The risk was double in African-Americans compared to whites. Age, body mass index, family history of diabetes, and etiology of renal failure did not predict diabetes; however, the mean age of patients was greater than previously reported., Conclusions: The majority of patients are at risk of developing new-onset diabetes within a short time after kidney transplantation. The risk may be due to preexisting risk factors, immunosuppressive agents, or older age. The significance of these findings is not clear, but demands appropriate follow-up studies related to glycemia, end-organ complications, and graft function. It remains to be determined whether the 2003 International Consensus Guidelines are adequate to appropriately diagnose diabetes in the posttransplant time period, with special emphasis on the first 3 months.
- Published
- 2005
- Full Text
- View/download PDF
29. Histoplasmosis in solid organ transplant recipients at a large Midwestern university transplant center.
- Author
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Freifeld AG, Iwen PC, Lesiak BL, Gilroy RK, Stevens RB, and Kalil AC
- Subjects
- Adolescent, Adult, Female, Histoplasma isolation & purification, Histoplasmosis diagnosis, Histoplasmosis microbiology, Humans, Male, Middle Aged, Nebraska epidemiology, Academic Medical Centers, Histoplasmosis epidemiology, Organ Transplantation adverse effects
- Abstract
Histoplasma capsulatum sporadically causes severe infections in solid organ transplant (SOT) patients in the Midwest, but it has been an unusual infection among those patients followed at the University of Nebraska Medical Center (UNMC), located at the western edge of the 'histo belt.' Nine SOT patients with histoplasmosis are described (6 renal or renal-pancreas and 3 liver recipients) who developed severe histoplasmosis over a recent 2.5-year period at UNMC. Symptoms started a median of 11 months (range, 1.2-90 months) after organ transplant and consisted primarily of fever, cough, shortness of breath, and malaise or fatigue present for approximately 30 days prior to medical evaluation. All patients had an abnormal chest radiograph and/or computed tomographic scan. Tacrolimus was the main immunosuppressant in all 9 patients, along with prednisone or mycophenolate. Dacluzimab or thymoglobulin had been given around the time of transplant in 6 of 9. None was treated for an episode of acute rejection within 2 months before onset of histoplasmosis, although 2 were on high-dose immunosuppression after recent transplants. Diagnosis was made by culture in 8 of the 9 patients, with positive serum and urine histoplasma antigen tests in all 9 cases. From 1997 to 2001, during a period of relative quiescence of the disease in the general population, the rate of clinical histoplasmosis among SOT patients at UNMC was estimated at 0.11%, whereas during 2002 through the first half of 2004, the rate rose 17-fold to 1.9%. Histoplasmosis can present as a prolonged febrile illness with subacute pulmonary symptoms in a cohort of SOT patients, despite the absence of a regional outbreak.
- Published
- 2005
- Full Text
- View/download PDF
30. Greater early pancreas graft loss in women compared with men after simultaneous pancreas-kidney transplantation.
- Author
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Colling C, Stevens RB, Lyden E, Lane J, Mack-Shipman L, Wrenshall L, and Larsen J
- Subjects
- Adult, Age Factors, Body Mass Index, Diabetes Complications physiopathology, Female, Follow-Up Studies, Humans, Immunosuppression Therapy, Male, Middle Aged, Pancreas Transplantation methods, Sex Factors, Survival Rate, Time Factors, Treatment Outcome, Graft Survival physiology, Kidney Transplantation methods, Pancreas Transplantation physiology
- Abstract
Background: Gender differences in graft survival has been reported after some types of organ transplantation, but not after pancreas transplantation. This study compares graft survival between women and men after simultaneous pancreas-kidney transplantation (SPK)., Methods: All first time SPK (n = 163) transplants (109 M/54 F) performed between 1989 and 2000 at University of Nebraska Medical Center, where data was available, were analyzed for overall graft and patient survival. Graft failure was then subdivided into early (<6 months), and late (>6 months), and compared between women and men., Results: The 5-yr pancreas and kidney graft survival rates for all SPK recipients was 86% [95% confidence interval (CI) = 81-92%] and 87% (95% CI = 82-93%), respectively. While overall pancreas graft survival in women was similar to men (p = 0.16), early pancreas graft failure was greater in women than men (p = 0.010) with no one cause for failure predominant. There was no gender difference in late pancreas graft failure or in early, or late kidney graft failure in the same recipients. The gender difference was unexplained by differences in age, immunosuppression, body mass index (BMI), or diabetes duration between women and men., Conclusions: This is the first report of a gender difference in pancreas graft survival after SPK with greater early (<6 months) pancreas graft failure in women than men. With no gender difference in kidney graft failure in the same individuals, gender differences in immune responses are unlikely to be the cause. Multiple variables likely contribute.
- Published
- 2005
- Full Text
- View/download PDF
31. Confidence in vaccination: a parent model.
- Author
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Keane MT, Walter MV, Patel BI, Moorthy S, Stevens RB, Bradley KM, Buford JF, Anderson EL, Anderson LP, Tibbals K, and Vernon TM
- Subjects
- Adolescent, Child, Health Care Surveys, Health Knowledge, Attitudes, Practice, Humans, Parents psychology, Patient Acceptance of Health Care, Vaccination
- Abstract
Although vaccination has been heralded as one of the 10 greatest public health achievements, how parents differ in their views about vaccination is not well understood. A deeper understanding of these attitudes and beliefs may improve the effectiveness of vaccine communications. In this mailed survey of U.S. parents in January 2001 (return response rate 49%), parental confidence in vaccination was very high, although there was significant variation among parents. Using multivariate analyses to group and profile parents, 90% of parents (n=1820) were classified into one of four distinct parent groups: (1) "Vaccine Believer" parents who were convinced of the benefit of vaccination; (2) "Cautious" parents noteworthy for a high emotional investment in their child; (3) "Relaxed" parents characterized by a less involved parenting style and some skepticism about vaccines; and (4) "Unconvinced" parents distinguished by their distrust of vaccinations and vaccination policy. These findings suggest that messages that are customized to parents' attitudes and beliefs may improve their understanding and acceptance of vaccination.
- Published
- 2005
- Full Text
- View/download PDF
32. West Nile virus-associated encephalitis in recipients of renal and pancreas transplants: case series and literature review.
- Author
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Ravindra KV, Freifeld AG, Kalil AC, Mercer DF, Grant WJ, Botha JF, Wrenshall LE, and Stevens RB
- Subjects
- Adult, Child, Preschool, Encephalitis virology, Female, Humans, Immunocompromised Host, Immunosuppression Therapy, Male, Opportunistic Infections etiology, Opportunistic Infections virology, Transplantation, West Nile Fever virology, Encephalitis etiology, Kidney Transplantation adverse effects, Pancreas Transplantation adverse effects, West Nile Fever etiology, West Nile virus
- Abstract
Although West Nile fever is mild in the vast majority of infected persons, there is growing evidence that the disease may be more severe in the immunocompromised population. We describe 3 recipients of kidney or pancreas transplants who developed West Nile fever, 2 of whom had meningoencephalitis. As is the norm when treating serious infections in transplant recipients, a reduction of immunosuppression was pursued for these patients. Despite the severe nature of the disease in 2 patients, all recovered from the disease. The time course of neurologic recovery in the 2 patients with meningoencephalitis is highlighted. We also review the literature on West Nile fever in organ transplant recipients. In areas where West Nile virus is endemic, one must have a high index of suspicion for the illness when dealing with fever in transplant recipients.
- Published
- 2004
- Full Text
- View/download PDF
33. Extended donor iliac arterial patch for vascular reconstruction during pancreas transplantation.
- Author
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Mercer DF, Rigley T, and Stevens RB
- Subjects
- Adult, Female, Humans, Iliac Artery transplantation, Pancreas blood supply, Pancreas Transplantation
- Abstract
Iliac arteries in allograft pancreas recipients may be compromised by the patient's underlying disease or previous surgical intervention. We describe a previously unreported arterial reconstruction using an extended segmental common/external iliac artery patch with anastomosis of the pancreatic Y-graft to the patch internal iliac artery, and review the options for arterial reconstruction reported by others. This technique may find application in both pancreas and kidney transplantation to salvage a damaged or diseased iliac artery.
- Published
- 2004
- Full Text
- View/download PDF
34. There are no differences in pretransplant characteristics of individuals receiving simultaneous pancreas-kidney transplant and individuals with type 1 diabetes mellitus receiving living-related kidney transplant.
- Author
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Donigan L, Stevens RB, Wrenshall L, and Larsen J
- Subjects
- Blood Pressure, Body Mass Index, Family, Humans, Lipids blood, Preoperative Care, Retrospective Studies, Treatment Outcome, Diabetes Mellitus, Type 1 surgery, Diabetic Nephropathies surgery, Kidney Transplantation physiology, Living Donors, Pancreas Transplantation physiology
- Abstract
Simultaneous pancreas-kidney transplantation (SPK) recipients have longer survival compared to type 1 diabetes mellitus (DM1) cadaveric kidney recipients. However, DM1 living-related kidney transplant (KTX-LR) recipients have the same mortality as SPK recipients. It is unknown whether cardiovascular (CVD) risk factors pretransplant are similar between the two groups, SPK and DM1 KTX-LR. We analyzed pretransplant characteristics of SPK recipients (n = 39) and DM1 KTX-LR/living unrelated (LUR) recipients (KTX-LR/LUR, n = 20). In individuals who had multiple transplants, only pretransplant data from the first transplant was used. As all characteristics of KTX-LR/LUR recipients were the same, they were grouped for comparison with SPK. Pretransplant blood pressure (BP), body mass index, (BMI), hemoglobin A1c (A1c), total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides (TG), serum creatinine, type and duration of dialysis, and duration of diabetes were compared between the two groups. Mean age at time of transplantation was 41 +/- 1 years (mean +/- SEM) for SPK versus 39 +/- 2 years for KTX-LR/LUR (P = NS). Pretransplant BP, BMI, duration of diabetes, TC, HDL, LDL, TG, and lipid agent use were not different between the groups. Pretransplant A1c was 7.8 +/- 0.3% for SPK recipients and 8.3 +/- 0.5% for KTX-LR/LUR recipients (P = NS). Pretransplant serum creatinine was higher in KTX-LR/LUR compared to SPK (7.9 +/- 0.6 mg/dL versus 5.4 +/- 0.5 mg/dL; P =.01). Except for serum creatinine, there were no significant differences in traditional CVD risk factors pretransplant. However, factors posttransplant in addition to better glucose control with SPK may still be different between SPK and KTX-LR/LUR groups.
- Published
- 2004
- Full Text
- View/download PDF
35. Improved islet yields from Macaca nemestrina and marginal human pancreata after two-layer method preservation and endogenous trypsin inhibition.
- Author
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Matsumoto S, Rigley TH, Reems JA, Kuroda Y, and Stevens RB
- Subjects
- Animals, Humans, Macaca nemestrina, Transplantation, Heterologous, Islets of Langerhans Transplantation methods, Oxygen metabolism, Sulfones metabolism, Tissue Preservation methods, Trypsin, Trypsin Inhibitors
- Abstract
We tested whether two-layer method (TLM) pancreas preservation and trypsin inhibition (Pefabloc) during processing allows longer preservation while retaining or improving viable islet recovery. Non-marginal primate (Macaca nemestrina) and marginal human (ischemic or preservation-injured) pancreata were processed with a research-oriented pan technique (Seattle method). Organs were processed upon arrival (+/- Pefabloc), or after TLM or University of Wisconsin solution (UW) preservation (+ Pefabloc). Islet yield, viability, and function were assessed. Pefabloc increased M. nemestrina islet yields from 9696 +/- 1749 IE/g to 15 822 +/- 1332 IE/g (p < 0.01). Two-layer method preservation (< 6 h) further increased yields, to 23 769 +/- 2773 IE/g (vs. + Pefabloc; p < 0.01). Similarly, Pefabloc increased marginal human islet yields from 2473 +/- 472 IE/g to 4723 +/- 1006 IE/g (p < 0.04). This increase was maintained after lengthy TLM preservation (> 30 h; 4801 +/- 1066 IE/g). We also tested the applicability of TLM preservation (23.5 +/- 3.2 h) to the processing of marginal human pancreata by the Edmonton/Immune Tolerance Network clinical protocol. Islet yield and function approached published results of pancreata processed 4.8 +/- 0.8 h after organ recovery (p = 0.06). Pefabloc, and TLM vs. UW preservation, prolonged the tolerable interval between organ recovery and islet isolation. Islet yield, viability, and functionality improved from both marginal and nonmarginal pancreata.
- Published
- 2003
- Full Text
- View/download PDF
36. Efficacy of the oxygen-charged static two-layer method for short-term pancreas preservation and islet isolation from nonhuman primate and human pancreata.
- Author
-
Matsumoto S, Rigley TH, Qualley SA, Kuroda Y, Reems JA, and Stevens RB
- Subjects
- Adenosine pharmacology, Adenosine Triphosphate analysis, Allopurinol pharmacology, Animals, Cells, Cultured, Female, Glutathione pharmacology, Humans, Insulin pharmacology, Islets of Langerhans chemistry, Islets of Langerhans cytology, Macaca nemestrina, Male, Raffinose pharmacology, Transportation, Islets of Langerhans Transplantation, Organ Preservation Solutions, Oxygen pharmacology, Tissue Preservation methods
- Abstract
Previous reports indicate that the two-layer method (TLM) of human pancreas preservation is superior to University of Wisconsin solution (UW) when pancreata are preserved for extended periods (i.e., >24 h) prior to islet isolation. In this study, the efficacy of using the TLM for preserving pancreata for short periods (i.e., <13 h) was evaluated using both nonhuman primate and human pancreata preserved with a TLM kit precharged with oxygen. An oxygen precharged TLM (static TLM) was established and compared with the original TLM with continuous oxygen supply. For the static TLM, the perfluorochemical was fully oxygenated and the oxygen supply removed prior to pancreas preservation. In the primate model, pancreata were preserved by the static TLM, the original TLM, and UW for 5 h prior to islet isolation. In the human model, pancreata were preserved with the static TLM or the original TLM or UW for 4-13 h. Both primate and human pancreata were processed by intraductal collagenase injection and digestion followed by continuous density gradient purification to isolate islets. Islets were assessed for islet yield, purity, viability, and in vitro functionality. In the primate model, islet yield, viability, and in vitro functionality were significantly improved by both the static TLM and the original TLM with similar results. Postculture islet yields were 23,877 +/- 3619 IE/g in the static TLM, 21,895 +/- 3742 IE/g in the original TLM, and 6773 +/- 735 IE/g in UW. In the human model, both the static TLM and the original TLM significantly increased islet yield compared with UW with postculture islet yields of 2659 +/- 549 IE/g in the static TLM, 2244 +/- 557 IE/g in the original TLM, and 1293 +/- 451 IE/g in UW. Nonhuman primate and human pancreata stored in the static TLM, immediately upon procurement, yield isolated islets of a substantially higher quantity than when pancreata are stored in UW. Thus, the use of the static TLM should replace the use of UW for storage of pancreata during transport prior to islet isolation.
- Published
- 2002
37. Modulation of immune responses after portal venous injection of antigen.
- Author
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Wrenshall LE, Ansite JD, Eckman PM, Heilman MJ, Stevens RB, and Sutherland DE
- Subjects
- Adoptive Transfer, Animals, Antibody Formation, Cell Division physiology, Epitopes, Female, Injections, Intravenous, Lymph Nodes cytology, Mice, Mice, Inbred BALB C, Ovalbumin administration & dosage, Ovalbumin immunology, Portal Vein, Serum Albumin administration & dosage, Serum Albumin pharmacokinetics, Spleen, T-Lymphocytes cytology, T-Lymphocytes immunology, T-Lymphocytes transplantation, Tissue Distribution, Antigens administration & dosage, Antigens immunology, Immune Tolerance physiology, Liver immunology
- Abstract
Background: How the localization of antigen to the liver, through means such as oral ingestion, induces tolerance is poorly understood., Methods: To elucidate potential mechanisms we used an adoptive transfer system wherein ova-specific T cells were infused into a syngeneic host, and antigen-specific T-cell responses after delivery of soluble antigen into the liver were monitored., Results: After infusion of antigen into the portal vein, the frequency of antigen-specific T cells in lymph nodes draining the liver was lower than the frequency in peripheral lymph nodes. These findings were the reverse of what is typically observed after subcutaneous injection of antigen with adjuvant. Infusion of antigen with adjuvant into the portal vein did not alter this pattern of antigen-specific T-cell localization; however, an increased frequency of T cells, compared with antigen alone, was observed in peripheral lymph nodes and spleen. After exposure to antigen via the portal vein, T cells isolated from lymph nodes draining the liver and challenged with antigen in vitro exhibited a diminished proliferative response compared with T cells isolated from nondraining lymph nodes. This hyporesponsiveness was not observed when the antigen was administered with adjuvant., Conclusions: Our findings suggest that the influence of the liver on immune responses might reflect two processes: (1) loss of antigen-specific T cells after primary antigen injection, and (2) hyporesponsiveness on reexposure to antigen. These mechanisms may contribute to the prevention of undesirable immune responses to foods and enteric bacteria in the gastrointestinal tract. Furthermore, these results underscore the importance of minimizing inflammation in circumstances such as islet transplantation, if endogenous mechanisms of tolerance induction are to be maximized.
- Published
- 2001
- Full Text
- View/download PDF
38. University of wisconsin solution with trypsin inhibitor pefabloc improves survival of viable human and primate impure islets during storage.
- Author
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Matsumoto S, Lawrence O, Rigley TH, Lakey JR, Stevens RB, and Strong DM
- Abstract
Background. Recent studies suggest that impure islets (islets which have not been isolated from exocrine tissue and other parts of the pancreas) have great potential for successful transplantation. The evidence that supports this view includes findings that embedded islets (islets surrounded by exocrine tissue) undergo less apoptosis, peripancreatic lymph nodes prevent recurrence of IDDM (insulin dependent diabetes mellitus), and that islet yields and insulin content decrease during the purification process. Improved protocols have also been developed to prevent allorejection of impure islets. Despite these promising results, the storage of impure islets remains difficult, and was a method sought to decrease storage losses.Methods. Storage methods of impure human and non-human primate islets were compared, using either culture media or University of Wisconsin solution (UW). The effects of trypsin inhibition using Pefabloc (Roche Molecular Biochemicals, Indianapolis, IN) during storage period were also examined.Results. Low temperature and inhibition of trypsin activity during storage of impure islets improved both islet yield and viability. It was found that using UW solution and trypsin inhibition allowed perfect preservation of viable impure islets up to 48 h. A functional assay by glucose stimulation test showed these impure islet responded to glucose stimulation after 24 h.Conclusion. The benefits of storing impure islets using UW solution and Pefabloc at low temperature have been established. This improved method of preserving impure islets makes this model of transplantation even more viable.
- Published
- 2001
- Full Text
- View/download PDF
39. Modulation of macrophage and B cell function by glycosaminoglycans.
- Author
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Wrenshall LE, Stevens RB, Cerra FB, and Platt JL
- Subjects
- Animals, B-Lymphocytes immunology, Chondroitin Sulfates pharmacology, Cytotoxicity, Immunologic drug effects, Dermatan Sulfate pharmacology, Dinoprostone metabolism, Female, Heparin pharmacology, Heparitin Sulfate pharmacology, Histocompatibility Antigens Class II biosynthesis, Intercellular Adhesion Molecule-1 biosynthesis, Interleukin-1 metabolism, Interleukin-6 metabolism, Lipopolysaccharides pharmacology, Lymphocyte Culture Test, Mixed, Macrophages, Peritoneal physiology, Mice, Mice, Inbred BALB C, Nitric Oxide biosynthesis, Th1 Cells drug effects, Th1 Cells metabolism, Transforming Growth Factor beta metabolism, Tumor Necrosis Factor-alpha metabolism, Antigen Presentation drug effects, B-Lymphocytes drug effects, Glycosaminoglycans pharmacology, Macrophage Activation drug effects, Macrophages, Peritoneal drug effects
- Abstract
There is increasing evidence that the behavior of antigen-presenting cells may be regulated, in part, by the surrounding microenvironment. Components of the microenvironment of solid tissues that might influence antigen-presenting cell functions include glycosaminoglycans. We previously showed that heparan sulfate glycosaminoglycans activate macrophages, leading to profound alterations in T cell responses. Here we demonstrate the functional changes that occur in murine antigen-presenting cells induced by heparan sulfate and other glycosaminoglycans, and postulate how these functional changes influence the nature of local immune responses. Heparan sulfate triggered up-regulation of ICAM-1 and I-A, caused the release by antigen-presenting cells of interleukin (IL)-1, IL-6, tumor necrosis factor, IL-12, transforming growth factor beta, and prostaglandin E2 (PGE2), and (in macrophages) induced cytotoxic capability. Heparin induced IL-12 and interferon-gamma production but did not promote the release of other cytokines. Chondroitin sulfate and dermatan sulfate, although not stimulating the production of cytokines or of PGE2, elicited the production by macrophages of nitric oxide. These findings support a model in which the glycosaminoglycan composition of a given tissue, which may be altered by inflammatory processes, helps to regulate the behavior of antigen-presenting cells, which in turn determines the characteristics of the immune response that ensues.
- Published
- 1999
- Full Text
- View/download PDF
40. Renal pedicle torsion after simultaneous kidney-pancreas transplantation.
- Author
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West MS, Stevens RB, Metrakos P, Foshager MC, Jessurun J, Sutherland DE, and Gruessner RW
- Subjects
- Adult, Biopsy, Female, Humans, Kidney pathology, Kidney Diseases diagnostic imaging, Kidney Diseases pathology, Male, Middle Aged, Retrospective Studies, Torsion Abnormality diagnostic imaging, Torsion Abnormality etiology, Ultrasonography, Doppler, Color, Kidney Diseases etiology, Kidney Transplantation, Pancreas Transplantation, Postoperative Complications diagnostic imaging
- Abstract
Background: Simultaneous kidney-pancreas transplantation has become a recognized therapy for type I diabetes mellitus patients with diabetic nephropathy, neuropathy, and retinopathy. In the vast majority of these procedures, both grafts are placed intraperitoneally, which reduces posttransplant morbidity. Recently, in some of our recipients, we noted renal dysfunction related to complications of the renal pedicle. Our objectives in this study were to identify the cause of this renal dysfunction and to prevent its occurrence in future recipients., Study Design: We undertook a retrospective chart review of simultaneous kidney-pancreas recipients who experienced renal dysfunction related to renal pedicle complications., Results: We found four recipients with renal dysfunction related to renal pedicle torsion, diagnosed by serial ultrasound scans and kidney graft biopsies. Early diagnosis allowed salvage of three kidney grafts, but one was lost after late diagnosis., Conclusions: A high level of suspicion is needed to diagnose renal pedicle torsion. If simultaneous kidney-pancreas recipients have recurrent renal dysfunction, and rejection has been excluded, serial ultrasound scans with color flow Doppler examinations are needed. Once the diagnosis is made, a nephropexy to the anterior abdominal wall is indicated to prevent further torsion and save the kidney graft. We recommend prophylactic nephropexy of left renal grafts if the renal pedicle is > or = 5 cm long and if there is a 2 cm or more discrepancy between the length of the artery and the vein.
- Published
- 1998
- Full Text
- View/download PDF
41. Insulin down-regulates the inducible nitric oxide synthase pathway: nitric oxide as cause and effect of diabetes?
- Author
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Stevens RB, Sutherland DE, Ansite JD, Saxena M, Rossini TJ, Levay-Young BK, Hering BJ, and Mills CD
- Subjects
- Animals, Diabetes Mellitus metabolism, Diabetes Mellitus, Experimental etiology, Diabetes Mellitus, Experimental metabolism, Down-Regulation, Enzyme Induction, Macrophages metabolism, Nitric Oxide Synthase Type II, Rats, Rats, Inbred BB, Transforming Growth Factor beta metabolism, Diabetes Mellitus etiology, Insulin pharmacology, Nitric Oxide physiology, Nitric Oxide Synthase biosynthesis
- Abstract
Evidence in this paper indicates that insulin can down-regulate the inducible nitric oxide synthase (iNOS) pathway in vivo. The iNOS pathway is up-regulated in diabetes-prone rats and mice and is associated with an autoimmune process. However, the results presented here indicate that macrophage nitric oxide (NO) production and iNOS mRNA expression are also elevated in rats or mice made diabetic by streptozotocin injection in which there is no primary autoimmune component. Insulin administration reduces NO production in autoimmune-prone and streptozotocin-induced diabetic rodents. Finally, insulin decreases macrophage NO production in normal hosts. These results indicate that the autoimmune paradigm is inadequate to explain increased NO in diabetes. As a potential mechanism to explain insulin-mediated regulation of NO production, TGF-1 may be involved because 1) macrophages from diabetic mice produce less TGF-beta1 than macrophages from normal hosts; 2) the circulating TGF-beta1 level is lower in diabetic mice; and 3) insulin administration increases circulating TGF-beta1 in normal mice. Together, these results provide evidence that increased NO in diabetes is not only a cause but also an effect of beta-cell destruction and results in part from a heretofore unrecognized immunomodulatory activity of insulin.
- Published
- 1997
42. Nitric oxide mediates early dysfunction of rat and mouse islets after transplantation.
- Author
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Stevens RB, Ansite JD, Mills CD, Lokeh A, Rossini TJ, Saxena M, Brown RR, and Sutherland DE
- Subjects
- Animals, Arginine analogs & derivatives, Arginine pharmacology, Base Sequence, Enzyme Induction, Leukocytes, Mononuclear immunology, Liver drug effects, Liver metabolism, Male, Mice, Mice, Inbred C57BL, Molecular Sequence Data, Nitrates blood, Nitric Oxide biosynthesis, Nitric Oxide Synthase biosynthesis, Nitric Oxide Synthase metabolism, RNA, Messenger metabolism, Rats, Rats, Inbred Lew, Rats, Wistar, omega-N-Methylarginine, Islets of Langerhans physiology, Islets of Langerhans Transplantation, Nitric Oxide physiology
- Abstract
Evidence presented in this paper indicates that nitric oxide (NO), generated by a nonspecific "wound"-type of inflammation, is an important mediator of the early dysfunction of transplanted islets in rodents. Although allogeneic islets stimulate NO production to a greater degree than syngeneic islets, the amounts of NO produced after either are significantly elevated above baseline. Inhibition of NO production by N(G)-monomethyl-L-arginine (NMA), markedly decreases the time needed to restore euglycemia after intraportal transplantation of syngeneic islets in diabetic rats. The dose of NMA used was not observably toxic, with no significant changes in blood pressure, hepatic artery blood flow, serum hepatic enzyme levels, or in weight compared with control animals. In rat recipients of intraportal syngeneic transplants, evidence that NO is produced at the site of implantation includes (1) an early and transient increase in posttransplant hepatic vein nitrate levels (pretransplant, 90 microM; 24 hr, 230 microM; 48 hr, 250 microM; 72 hr, 170 microM; and 96 hr, 140 microM), (2) concurrent appearance of inducible NO synthase mRNA in liver extracts, and (3) immunohistochemical localization of inducible NO synthase within the transplanted islets. Suppression of NO production or inhibition of NO activity is a potential strategy to increase the early function and engraftment transplanted islets in the clinical setting.
- Published
- 1996
- Full Text
- View/download PDF
43. The effect of aging on the transarterial wall oxygen gradient.
- Author
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Santilli SM, Stevens RB, Anderson JG, and Caldwell MD
- Subjects
- Aging pathology, Analysis of Variance, Animals, Aorta, Abdominal pathology, Blood Pressure, Oxygen blood, Partial Pressure, Rats, Rats, Inbred F344, Aging metabolism, Aorta, Abdominal metabolism, Oxygen metabolism
- Abstract
Atherosclerosis is associated with aging based on numerous epidemiologic studies, whereas arterial wall hypoxia has been associated with other risk factors for atherosclerosis. We studied the effect of age on the transarterial wall oxygen gradient in the rat using an oxygen microelectrode. A decrease in oxygen tension in the outer 35% of the artery wall was noted in 36- to 40-week-old rats when compared to 3- to 4-week-old rats. These findings were noted despite no difference in arterial blood oxygen tension between the two groups and prior to any histologic evidence of atherosclerotic lesion formation. Our observations suggest that aging decreases the delivery of oxygen to the outer artery wall.
- Published
- 1995
- Full Text
- View/download PDF
44. Administration of NG-monomethyl-L-arginine in a marginal renal subcapsular mouse islet transplant model.
- Author
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Ansite JD, Stevens RB, Lokeh A, Brown RR, Saxena M, Mills CD, and Sutherland DE
- Subjects
- Animals, Arginine administration & dosage, Arginine pharmacology, Blood Glucose metabolism, Diabetes Mellitus, Experimental blood, Drug Administration Schedule, Infusions, Parenteral, Injections, Intraperitoneal, Mice, Mice, Inbred C57BL, Transplantation, Heterotopic, Transplantation, Isogeneic, omega-N-Methylarginine, Arginine analogs & derivatives, Diabetes Mellitus, Experimental therapy, Islets of Langerhans Transplantation physiology, Nitric Oxide antagonists & inhibitors
- Published
- 1995
45. Expression of intrahepatic inducible nitric oxide synthetase mRNA correlates with production of nitric oxide during intraportal isogeneic and allogeneic rat islet transplantation.
- Author
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Stevens RB, Ansite JD, Lokeh A, Rossini TJ, Mills CD, and Sutherland DE
- Subjects
- Animals, Arginine analogs & derivatives, Arginine pharmacology, Diabetes Mellitus, Experimental blood, Enzyme Induction, Graft Rejection physiopathology, Nitrates blood, Nitric Oxide antagonists & inhibitors, Nitric Oxide Synthase, Polymerase Chain Reaction, Portal System, RNA, Messenger analysis, RNA, Messenger biosynthesis, Rats, Rats, Inbred Lew, Rats, Wistar, T-Lymphocytes immunology, Time Factors, Transplantation, Homologous physiology, Transplantation, Isogeneic physiology, omega-N-Methylarginine, Amino Acid Oxidoreductases biosynthesis, Diabetes Mellitus, Experimental therapy, Gene Expression, Islets of Langerhans Transplantation physiology, Liver enzymology, Nitric Oxide biosynthesis
- Abstract
Intrahepatic NO production is related to the islet mass transplanted. Nitric oxide production is higher in recipients of allogeneic rather than syngeneic islets. In addition, in allogeneic recipients a possible second peak of NO production was observed at 120 hours corresponding to the time of cellular rejection of the islet grafts (P = .22 vs 96 hours). Finally, the time to rejection of Wistar rat donor islets transplanted into Lewis rat diabetic recipients treated with NMA was not affected. However, inhibiting NO production in the minimal islet transplant model decreased the time to islet function, it does not affect the time to clinical rejection in recipients of a high number of allogeneic islet, which functions immediately. High-level NO has been shown to inhibit T-cell activation in vitro, and thus decreasing the levels by administrating NMA may accentuate the rejection response, canceling out the beneficial effect that might otherwise have occurred on islet function. Further experiments are required to clarify these issues.
- Published
- 1995
46. Transarterial wall oxygen gradients at the dog carotid bifurcation.
- Author
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Santilli SM, Stevens RB, Anderson JG, Payne WD, and Caldwell MD
- Subjects
- Analysis of Variance, Animals, Blood Pressure, Carotid Arteries anatomy & histology, Dogs, Microelectrodes, Muscle, Smooth, Vascular anatomy & histology, Muscle, Smooth, Vascular physiology, Oxygen blood, Partial Pressure, Carotid Arteries physiology, Oxygen metabolism
- Abstract
The purpose of this study was to determine the effect of the carotid artery bifurcation on the delivery of oxygen to the artery wall by measuring the transarterial wall oxygen gradient. Transarterial wall oxygen gradient measurements were performed in dogs anesthetized with thiopental sodium and isoflurane by means of an oxygen microelectrode. Measurements were performed at six locations along the carotid bifurcation. Oxygen tensions at the carotid sinus were decreased in the inner 40% of the artery wall compared with control locations. Oxygen tensions at the flow divider were increased throughout the artery wall compared with control locations. These effects were noted without differences in blood pressure, arterial blood oxygen tension, or histological evidence of atherosclerotic lesion formation. These findings suggest that the delivery of oxygen to the artery wall is altered by the bifurcation of the carotid artery. Low arterial oxygen tensions at the carotid sinus support a role for artery wall hypoxia in the formation of atherosclerotic lesions.
- Published
- 1995
- Full Text
- View/download PDF
47. Nitric oxide in autoimmunity and cell transplantation.
- Author
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Mills CD, Stevens RB, and Sutherland DE
- Subjects
- Adenocarcinoma immunology, Adenocarcinoma physiopathology, Animals, Autoimmune Diseases immunology, Diabetes Mellitus, Type 1 immunology, Macrophages physiology, Mammary Neoplasms, Experimental immunology, Mammary Neoplasms, Experimental physiopathology, Mice, Mice, Inbred Strains, Neoplasm Transplantation, Nitric Oxide analysis, Rats, Rats, Inbred BB, Transplantation, Isogeneic, Autoimmune Diseases physiopathology, Autoimmunity, Cell Transplantation physiology, Diabetes Mellitus, Type 1 physiopathology, Nitric Oxide biosynthesis
- Published
- 1994
48. 15-Deoxyspergualin inhibits nitric oxide production in the BB/W rat: mechanism for inhibition of islet cell dysfunction in diabetes and transplantation.
- Author
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Stevens RB, Lokeh A, Ansite JD, Rossini TJ, Sutherland DE, and Mills CD
- Subjects
- Animals, Concanavalin A, Enzyme Induction, Islets of Langerhans drug effects, Islets of Langerhans Transplantation immunology, Lymphocyte Activation drug effects, Macrophages drug effects, Macrophages physiology, Nitric Oxide Synthase, Polymerase Chain Reaction methods, RNA, Messenger analysis, RNA, Messenger biosynthesis, Rats, Rats, Inbred BB, Rats, Inbred F344, Spleen immunology, T-Lymphocytes drug effects, T-Lymphocytes immunology, Amino Acid Oxidoreductases biosynthesis, Diabetes Mellitus, Type 1 therapy, Guanidines pharmacology, Immunosuppressive Agents pharmacology, Islets of Langerhans physiology, Islets of Langerhans Transplantation physiology, Nitric Oxide antagonists & inhibitors
- Published
- 1994
49. Administration of L-GN-monomethyl-arginine in a mouse islet transplant model.
- Author
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Stevens RB, Ansite JD, Lokeh A, Saxena M, Mills CD, and Sutherland DE
- Subjects
- Animals, Arginine therapeutic use, Blood Glucose metabolism, Diabetes Mellitus, Experimental blood, Mice, Mice, Inbred C57BL, Nitric Oxide antagonists & inhibitors, Transplantation, Heterotopic, omega-N-Methylarginine, Arginine analogs & derivatives, Diabetes Mellitus, Experimental therapy, Islets of Langerhans Transplantation physiology
- Published
- 1994
50. Eltoprazine in aggressive mentally handicapped patients: a double-blind, placebo- and baseline-controlled multi-centre study. The Eltoprazine Aggression Research Group.
- Author
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de Koning P, Mak M, de Vries MH, Allsopp LF, Stevens RB, Verbruggen R, Van den Borre R, van Peteghem P, Kohen D, and Arumainayagam M
- Subjects
- Adolescent, Adult, Aged, Dose-Response Relationship, Drug, Double-Blind Method, Female, Follow-Up Studies, Humans, Intellectual Disability psychology, Male, Middle Aged, Personality Assessment, Piperazines adverse effects, Serotonin Receptor Agonists adverse effects, Social Behavior, Treatment Outcome, Aggression drug effects, Intellectual Disability drug therapy, Piperazines therapeutic use, Serotonin Receptor Agonists therapeutic use
- Abstract
The efficacy of eltoprazine, a mixed 5-HT1 agonist, in treating aggressive behaviour in mentally handicapped patients was evaluated in a double-blind, placebo- and baseline-controlled study. In the total sample of 160 patients who entered the 8 week double-blind treatment phase, efficacy was not demonstrated. Also in a 28 week double-blind follow-up study, efficacy could not be demonstrated. Post-hoc exploratory analyses suggested eltoprazine was significantly better than placebo in reducing aggression scores of a subgroup of severely aggressive patients. There was no evident relationship between the plasma level of eltoprazine and therapeutic effect or safety and tolerance. The overall safety and tolerance of chronic eltoprazine treatment was good. In the discussion, several issues and pitfalls of aggression research are dealt with.
- Published
- 1994
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