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Michael S. Rohr

Bio: Michael S. Rohr is an academic researcher from Wake Forest University. The author has contributed to research in topics: Transplantation & Kidney transplantation. The author has an hindex of 17, co-authored 33 publications receiving 1442 citations. Previous affiliations of Michael S. Rohr include Wake Forest Baptist Medical Center.

Papers
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Journal Article
01 Oct 1988-Surgery
TL;DR: Use of PTFE to construct permanent hemodialysis vascular access has a significantly higher incidence of thrombosis, infection, pseudoaneurysm formation, and limb loss and a significantly lower mean length of patency when compared with autogenous fistulas.

282 citations

Journal ArticleDOI
TL;DR: The use of ECD kidneys at the authors' center effectively doubled their transplant volume within 1 year, and a systematic approach to E CD kidneys based on nephron mass matching and nephrons sparing measures may provide optimal utilization with short-term outcomes and renal function comparable to SCD kidneys.
Abstract: Objective:To compare outcomes in recipients of expanded criteria donor (ECD) versus standard criteria donor (SCD) kidneys at a single center using a standardized approach with similar immunosuppression.Summary Background Data:Expanded criteria deceased organ donors (ECD) are a source of kidneys that

124 citations

Journal ArticleDOI
TL;DR: By appropriate donor and recipient profiling and the use of management algorithms to project and protect renal function, excellent intermediate-term outcomes can be achieved with ECD kidneys transplants that are comparable to SCD kidney transplants.
Abstract: The burgeoning crisis in organ supply challenges the transplant community to maximize and optimize the use of organs from all consented donors. According to United Network for Organ Sharing (UNOS) data, in 2005, more than 60,000 candidates were on the active waiting list for kidney transplantation in the United States, while less than 15,000 kidney transplants were performed in 2004.1 Depending on blood type, median waiting times for a kidney transplant in the United States currently range from 2 to 6 years and continue to increase. Only 25% of active wait-list candidates are transplanted in a given year, and the chance of receiving a deceased donor kidney transplant within 1 year of listing is less than 10%. The waiting list has become a “waiting to die” list, as 6% of patients on the kidney waiting list (10% of diabetic patients) die each year awaiting a potential life-enhancing and life-prolonging transplant.1 The scarcity of available donor kidneys is a pervasive problem and mandates an ongoing reappraisal of the limits of acceptability when accepting kidney offers from deceased donors (DDs). The escalating disparity between organ supply and demand fuels initiatives not only to increase but also to optimize the utilization of available organs. Similar to trends in the overall U.S. general population, there has been an increasing yet disproportionate shift toward increasing numbers of older donors and recipients in kidney transplantation. In the last decade, the proportion of DDs older than 50 years of age has increased from 21% to 31%.2 Cerebrovascular events are now the leading cause of brain death culminating in deceased organ donation.3 Because of the convergence of demographic inevitability and medical advances in the aged, the use of kidneys from older donors has become generally, albeit reluctantly, accepted.4 Expanded criteria deceased donors (ECDs) over age 60 years and those aged 50 to 59 years with additional risk factors accounted for 177 kidney transplants nationally in 1988 and more than 1300 in 2004.1 However, the value of transplanting ECD kidneys has been questioned because of concerns over diminished graft survival and predicted poorer intermediate-term outcomes.4–6 Because it is our contention that ECD kidneys are defined by suboptimal nephron mass, we think that appropriate donor and recipient profiling and selection may maximize and optimize the use of this scarce and controversial resource.7 The purpose of this study was to review retrospectively our intermediate-term single center outcomes in ECD versus concurrent standard criteria deceased donor (SCD) kidney transplantation in adult patients receiving similar immunosuppression and management algorithms implemented to reduce renal injury and preserve nephron function.7

124 citations

Journal Article
TL;DR: Tacrolimus has been shown to have less adverse effect on the lipid profiles of transplant patients when the drug is started as induction therapy as mentioned in this paper, and conversion from cyclosporine-treated renal transplant patients with established hyperlipidemia can be safely done after successful transplantation.
Abstract: Background Tacrolimus has been shown to have a less adverse effect on the lipid profiles of transplant patients when the drug is started as induction therapy. In order to determine the effect tacrolimus has on lipid profiles in stable cyclosporine-treated renal transplant patients with established hyperlipidemia, a randomized prospective study was undertaken by the Southeastern Organ Procurement Foundation. Methods. Patients of the 13 transplant centers, with cholesterol of 240 mg/dl or greater, who were at least 1 year posttransplant with stable renal function, were randomly assigned to remain on cyclosporine (control) or converted to tacrolimus. Patients converted to tacrolimus were maintained at a level of 5-15 ng/ml, and control patients remained at their previous levels of cyclosporine. Concurrent immunosuppressants were not changed. Levels of total cholesterol, triglycerides, total high-density lipoprotein, low-density lipoprotein (LDL), very-low-density lipoprotein, and apoproteins A and B were monitored before conversion and at months 1, 3, and 6. Renal function and glucose control were evaluated at the beginning and end of the study (month 6). Results. A total of 65 patients were enrolled; 12 patients failed to complete the study. None were removed as a result of acute rejection or graft failure. Fifty-three patients were available for analysis (27 in the tacrolimus group and 26 controls). Demographics were not different between groups. In patients converted to tacrolimus treatment, there was a -55 mg/dl (-16%) (P=0.0031) change in cholesterol, a -48 mg/dl (-25%) (P=0.0014) change in LDL cholesterol, and a -36 mg/dl (-23%) (P=0.034) change in apolipoprotein B. There was no change in renal function, glycemic control, or incidence of new onset diabetes mellitus in the tacrolimus group. Conclusion. Conversion from cyclosporine to tacrolimus can be safely done after successful transplantation. Introduction of tacrolimus to a stable renal patient does not effect renal function or glycemic control. Tacrolimus can lower cholesterol, LDL, and apolipoprotein B. Conversion to tacrolimus from cyclosporine should be considered in the treatment of posttransplant hyperlipidemia.

124 citations

Journal ArticleDOI
TL;DR: Prophylactic monthly administration of thiabendazole in immunocompromised patients who have survived strongyloides hyperinfection or dissemination can prevent reinfection.
Abstract: Opportunistic infections with the nematode Strongyloides stercoralis occur most often in patients with impaired T lymphocyte function, including recipients of renal allografts. Occult intestinal infection can remain quiescent for more than 30 years, becoming apparent only after the initiation of immunosuppression. Pulmonary and gastrointestinal symptoms predominate as initial clinical manifestations in patients with strongyloides hyperinfection or dissemination. Although thiabendazole remains the treatment of choice for all forms of strongyloidiasis, the duration of therapy must be individualized on the basis of frequent examinations of both stool and sputum. Transplantation centers drawing patients from areas with endemic Strongyloides should evaluate potential recipients closely for occult strongyloides infection prior to initiating immunosuppressive therapy. Empiric therapy with thiabendazole should be considered for renal allograft recipients with unexplained eosinophilia and a history of travel or residence in an area with endemic Strongyloides. Prophylactic monthly administration of thiabendazole in immunocompromised patients who have survived strongyloides hyperinfection or dissemination can prevent reinfection. Infections produced by the nematode Strongyloides stercoralis have occurred with increasing frequency during the past decade largely as a result of the widespread use of immunosuppressive agents in the prevention of allograft rejection as well as in the treatment of malignancies and collagen vascular diseases. Currently, 37 cases of strongyloidiasis complicating renal transplantation have been reported or abstracted in English. We describe herein a renal allograft recipient who developed recurrent strongyloides hyperinfection 114 months after his initial episode. The clinical manifestations of strongyloidiasis in renal allograft recipients are reviewed, and guidelines are provided for early diagnosis and treatment.

123 citations


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ReportDOI
01 Jan 1967

890 citations

Journal ArticleDOI
TL;DR: The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access.

858 citations

Journal ArticleDOI
TL;DR: Anthelmintic agents such as ivermectin have been used successfully in treating the hyperinfection syndrome as well as for primary and secondary prevention of hyper Infection in patients whose exposure history and underlying condition put them at increased risk.
Abstract: Strongyloides stercoralis is an intestinal nematode of humans that infects tens of millions of people worldwide. S. stercoralis is unique among intestinal nematodes in its ability to complete its life cycle within the host through an asexual autoinfective cycle, allowing the infection to persist in the host indefinitely. Under some conditions associated with immunocompromise, this autoinfective cycle can become amplified into a potentially fatal hyperinfection syndrome, characterized by increased numbers of infective filariform larvae in stool and sputum and clinical manifestations of the increased parasite burden and migration, such as gastrointestinal bleeding and respiratory distress. S. stercoralis hyperinfection is often accompanied by sepsis or meningitis with enteric organisms. Glucocorticoid treatment and human T-lymphotropic virus type 1 infection are the two conditions most specifically associated with triggering hyperinfection, but cases have been reported in association with hematologic malignancy, malnutrition, and AIDS. Anthelmintic agents such as ivermectin have been used successfully in treating the hyperinfection syndrome as well as for primary and secondary prevention of hyperinfection in patients whose exposure history and underlying condition put them at increased risk.

834 citations

Journal ArticleDOI
TL;DR: Current antirejection therapy, including calcineurin blockers such as cyclosporine and tacrolimus, the interleukin-2 signal-transduction inhibitor sirolimus and the purine-synthesis inhibitor mycophenolate mofetil are discussed, which inhibits the proliferation of T cells and B cells.
Abstract: This article provides a comprehensive, up-to-date review of methods to prevent early and late renal-allograft loss and to improve long-term outcomes in patients. The authors focus particular attention on the problem of late graft loss and discuss current antirejection therapy, including calcineurin blockers such as cyclosporine and tacrolimus, the interleukin-2 signal-transduction inhibitor sirolimus, and the purine-synthesis inhibitor mycophenolate mofetil, which inhibits the proliferation of T cells and B cells.

830 citations

Journal ArticleDOI
TL;DR: Critics have started to question current reliance on trough measurement during therapeutic drug monitoring, with instances of toxicity and rejection occurring when trough concentrations are within ‘acceptable’ ranges, and controversy exists as to whether this will provide any great benefit, given the added complexity in monitoring.
Abstract: The aim of this review is to analyse critically the recent literature on the clinical pharmacokinetics and pharmacodynamics of tacrolimus in solid organ transplant recipients. Dosage and target concentration recommendations for tacrolimus vary from centre to centre, and large pharmacokinetic variability makes it difficult to predict what concentration will be achieved with a particular dose or dosage change. Therapeutic ranges have not been based on statistical approaches. The majority of pharmacokinetic studies have involved intense blood sampling in small homogeneous groups in the immediate post-transplant period. Most have used nonspecific immunoassays and provide little information on pharmacokinetic variability. Demographic investigations seeking correlations between pharmacokinetic parameters and patient factors have generally looked at one covariate at a time and have involved small patient numbers. Factors reported to influence the pharmacokinetics of tacrolimus include the patient group studied, hepatic dysfunction, hepatitis C status, time after transplantation, patient age, donor liver characteristics, recipient race, haematocrit and albumin concentrations, diurnal rhythm, food administration, corticosteroid dosage, diarrhoea and cytochrome P450 (CYP) isoenzyme and P-glycoprotein expression. Population analyses are adding to our understanding of the pharmacokinetics of tacrolimus, but such investigations are still in their infancy. A significant proportion of model variability remains unexplained. Population modelling and Bayesian forecasting may be improved if CYP isoenzymes and/or P-glycoprotein expression could be considered as covariates. Reports have been conflicting as to whether low tacrolimus trough concentrations are related to rejection. Several studies have demonstrated a correlation between high trough concentrations and toxicity, particularly nephrotoxicity. The best predictor of pharmacological effect may be drug concentrations in the transplanted organ itself. Researchers have started to question current reliance on trough measurement during therapeutic drug monitoring, with instances of toxicity and rejection occurring when trough concentrations are within 'acceptable' ranges. The correlation between blood concentration and drug exposure can be improved by use of non-trough timepoints. However, controversy exists as to whether this will provide any great benefit, given the added complexity in monitoring. Investigators are now attempting to quantify the pharmacological effects of tacrolimus on immune cells through assays that measure in vivo calcineurin inhibition and markers of immunosuppression such as cytokine concentration. To date, no studies have correlated pharmacodynamic marker assay results with immunosuppressive efficacy, as determined by allograft outcome, or investigated the relationship between calcineurin inhibition and drug adverse effects. Little is known about the magnitude of the pharmacodynamic variability of tacrolimus.

741 citations