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Biomedical subjects

K L Brayman

Publications and source records attributed to K L Brayman.

At least 37 records · Page 2Linked to original sources
PubMed1996

Reversal of acute renal allograft rejection by extracorporeal photopheresis: a case presentation and review of the literature.

There is a clear need for well-tolerated immunomodulatory agents that can aid in the prevention of acute solid organ rejection. Extracorporeal photopherosis is an apheresis-based therapy that is currently available at many medical centers worldwide. Preliminary studies utilizing photopheresis with standard immunosuppressives have shown this therapy to successfully reverse acute cellular rejection of cardiac allografts with minimal toxicity. No formal evaluation of the role of extracorporeal photopheresis had been performed in renal transplantation. In this report, photopheresis was successfully utilized to treat acute cellular rejection in a patient with a renal allograft. This lends further support to the existing literature suggesting that photopheresis may be useful for the reversal of acute solid organ rejection. Although our experience with this patient is anecdotal, photopheresis merits further study as treatment for severe renal allograft rejection.

Acute Disease↗
PubMed1996

Delayed function reduces renal allograft survival independent of acute rejection.

BACKGROUND: Mechanisms by which delayed allograft function reduces renal allograft survival are poorly understood. This study evaluated the relationship of delayed allograft function to acute rejection and long-term survival of cadaveric allografts. METHODS: 338 recipients of cadaveric allografts were followed until death, resumption of dialysis, retransplantation, loss to follow-up, or the study's end, which ever came first. Delayed allograft function was defined by dialysis during the first week following transplantation. Multivariate Cox proportional hazards survival analysis was used to assess the relationship of delayed allograft function to rejection and allograft survival. RESULTS: Delayed allograft function, recipient age, preformed reactive antibody levels, prior kidney transplantation, recipient race, rejection during the first 30 days and rejection subsequent to 30 days following transplantation were predictive of allograft survival in multivariate survival models. Delayed allograft function was associated with shorter allograft survival after adjustment for acute rejection and other covariates (relative rate of failure [RR]+1.72 [95% CI, 1.07, 2.76]). The adjusted RR of allograft failure associated with any rejection during the first 30 days was 1.99 (1.23, 3.21), and for rejection subsequent to the first 30 days was 3.53 (2.9 08, 6.00). The impact of delayed allograft function did not change substantially (RR=1.84 [1.15, 2.95]) in models not controlling for acute rejection. These results were stable among several subgroups of patients and using alternative definitions of allograft survival and delayed allograft function. CONCLUSIONS: This study demonstrates that delayed allograft function and acute allograft rejection have important independent and deleterious effects on cadaveric allograft survival. These results suggest that the effect of delayed allograft function is mediated, in part, through mechanisms not involving acute clinical rejection.

Acute Disease↗
PubMed1995

Cyclic AMP phosphodiesterases of human and rat islets of Langerhans: contributions of types III and IV to the modulation of insulin secretion.

This study evaluated the contribution of isozymes of cAMP phosphodiesterase (PDE) to total PDE activity in human and rat islets using type-selective inhibitors. The effects of selected PDE inhibitors on insulin secretion from human and rat islets were also measured in order to assess the contribution of the various PDE isozymes to the modulation of insulin secretion. The data suggest that PDE III is quantitatively the most important PDE isozyme present in islets, accounting for up to 70% of the total activity. Lower, but measurable, levels of PDE IV activity were present. Approximately 20% of islet PDE is not inhibitable by agents selective either for PDE III or IV. Selective inhibition of PDE III stimulated insulin secretion, but inhibition of PDE IV had no effect. The effects of type-selective inhibitors on PDE activity and insulin secretion were similar in human and rat islets.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1995

Analytic requirements for immunosuppressive drugs in clinical trials.

Essential to the evaluation of (1) the pharmacokinetics, (2) concentration-effect relationships, and (3) the application of therapeutic drug monitoring, during new immunosuppressive drug clinical trials, is the development of validated analytical methodology for the measurement of pharmacologically active drug and metabolites in biofluids and tissues. The characteristics of analytical methodology developed for cyclosporines A and G, FK-506, mycophenolate mofetil, and rapamycin during clinical trials will be described. The advantages of establishing validated analytical methodology as early as possible during clinical trials include: (a) early identification of metabolites and their quantitative and pharmacological significance; (b) early development of interpretable PK and PK-PD data; (c) accrual of experience that will be directly useful in patient monitoring after drug approval; (d) optimization of analysis conditions; and (e) early development of reference methodology for therapeutic drug monitoring tests. A suggested set of performance criteria for drug analysis during clinical trials and thereafter will be presented.

Clinical Trials as Topic↗