Maximum non-reactive concentration of midazolam and ketamine for skin testing study in non-allergic healthy volunteers.

The objective of our study was to determine the maximal non-reactive concentrations for midazolam and ketamine in healthy volunteers using both prick and intradermal skin tests. Twenty-one healthy Caucasian volunteers were tested for midazolam and ketamine using more clustered concentrations (identical for both prick and intradermal tests) than those resulting from decimal dilutions. The criteria for positivity were based on dilutions of drugs that cause wheal and flare reactions in subjects without history of allergy. For the prick method, the concentrations that did not produce wheal and flare were 1 mg/ml for midazolam and 10 mg/ml for ketamine. For intradermal tests, using serial dilutions, we found that the highest concentration for which the subjects did not pass the positivity criteria was 0.25 mg/ml for both drugs.

Pharmacokinetics of rosuvastatin in patients with end-stage kidney disease undergoing peritoneal dialysis.

Patients undergoing dialysis treatment have a high incidence of dyslipidemia. Rosuvastatin is a potent statin drug that improves overall lipid profiles in dyslipidemic patients. However, the pharmacokinetics of rosuvastatin has not been studied in patients with end-stage kidney disease undergoing chronic peritoneal dialysis (PD). The goals of this study are to determine the pharmacokinetics and tolerability of a single oral dose of rosuvastatin in patients undergoing continuous ambulatory PD (CAPD). This was a nonrandomized, open-label, 1-week trial. Ten stable PD patients were given a single oral dose of rosuvastatin (10 mg). Serial blood samples were obtained over the next 48 hours, and the patients were followed for 1 week while they underwent CAPD. Rosuvastatin plasma concentration peaked (Cmax) at 3.68 +/- 2.3 ng/ml (geometric mean), 4.5 hours (median; range 2 - 6 hours) after oral dosing. The plasma concentration of rosuvastatin was 0.44 +/- 0.23 ng/ml at 24 hours (C24) and 0.14 +/- 0.07 ng/ml, with levels below the detectable range in 5 of 10 subjects, at 48 hours (C48). The area under the plasma concentration-time from 0 to 48 hours (AUC0-48) was 32.6 +/- 1.6 ng/ml/h. These pharmacokinetic profiles of rosuvastatin in CAPD patients are very similar to those observed in healthy volunteers, but different from patients with Stages 4 - 5 chronic kidney disease. A single oral dose of rosuvastatin was well tolerated in this small number of patients. We conclude that pharmacokinetic profiles of rosuvastatin in patients undergoing CAPD are similar to those observed in healthy volunteers. These findings suggest that a lower dose of rosuvastatin (<<= 10 mg) may be administered in CAPD patients without dose adjustment.

Interleukin-6 predicts hypoalbuminemia, hypocholesterolemia, and mortality in hemodialysis patients.

Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpreted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reaction to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necrosis factor-alfa (TNF-alpha) and interleukin-6 (IL-6) predict serum albumin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), malignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dyslipoproteinemia. IL-6 was the strongest predictor of mortality in univariate and multivariate analysis, followed by age, albumin level, and body mass index (BMI). Although the cause of hypercytokinemia was not addressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflammatory stimuli. These results suggest that efforts to identify the nature of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis.

Molecular executors of cell death--differential intrarenal expression of Fas ligand, Fas, granzyme B, and perforin during acute and/or chronic rejection of human renal allografts.

Two distinct cytolytic pathways have been characterized: one in which the interaction between the Fas antigen and its ligand results in apoptosis, and another in which the pore forming protein perforin and the serine protease granzyme B contribute to DNA fragmentation and cell death. We investigated intrarenal expression of these molecular executors of cell death in light of the potential participation of cytolytically active cellular elements in the antiallograft repertory. Reverse transcriptase-polymerase chain reaction was used to identify intrarenal expression of Fas antigen, Fas ligand, granzyme B and perforin in eighty human renal allograft biopsies; mRNA display was correlated with the Banff histological diagnosis of renal allografts. Our studies demonstrate that: (1) intrarenal expression of Fas ligand mRNA and of granzyme B mRNA are correlates of acute but not chronic rejection; (2) Fas ligand mRNA is not detectable in allografts in the absence of rejection; (3) intrarenal coexpression of members of each lytic pathway (Fas ligand and Fas, granzyme B, and perforin) and that of both pathways (e.g., Fas ligand and granzyme B) are correlates of acute rejection; and (4) a direct correlation exists between the histological severity of acute rejection and intrarenal coexpression of mRNA encoding Fas ligand, Fas, granzyme B, and perforin. Our studies identify, for the first time, the differential expression of the two major lytic pathways in acute and chronic allograft rejection and suggest that specific therapy directed at the cytotoxic attack molecules might be efficacious in the prevention and/or treatment of acute rejection.

Intragraft TGF-beta 1 mRNA: a correlate of interstitial fibrosis and chronic allograft nephropathy.

Chronic allograft nephropathy is a relentlessly progressive process and a major cause of long-term graft dysfunction and ultimate failure. Interstitial fibrosis, tubular atrophy, and glomerular and vascular lesions characterize this mechanistically unresolved disorder. Given the prominent role of TGF-beta 1 in tissue repair and in fibrosis, we have explored the hypothesis that fibrosis and chronic allograft nephropathy would be distinguished by intragraft TGF-beta 1 mRNA expression. This postulate was tested by mRNA phenotyping of RNA isolated from 127 human renal allograft biopsies. Reverse transcription assisted polymerase chain reaction was used to amplify and identify ingraft gene expression. Our investigation demonstrated a significant correlation between intragraft TGF-beta 1 mRNA display and renal allograft interstitial fibrosis and chronic allograft nephropathy. In contrast, intragraft expression of mRNA encoding immunoregulatory cytokines, IL-2, IFN-gamma, IL-4, IL-10, or cytotoxic attack molecules, granzyme B and perforin was not a correlate of interstitial fibrosis or chronic allograft nephropathy. Our studies identify, for the first time, a significant association between intragraft TGF-beta 1 mRNA expression and renal allograft interstitial fibrosis, and advance a candidate molecular mechanism for chronic allograft nephropathy.

Intragraft expression of IL-10 messenger RNA: a novel correlate of renal allograft rejection.

A major conceptual advance is the formulation that type I cytokines (such as IL-2 and IFN-gamma) enhance cellular immunity and are host-protective, and that type II cytokines (such as IL-4 and IL-10) dampen cellular immunity and facilitate the progression of infection. We have explored the intragraft expression of type I and type II cytokines during human renal allograft rejection. RNA was isolated from 98 allograft biopsies, and reverse transcription-PCR was used to amplify and identify intragraft expression of mRNA encoding IL-2, IFN-gamma, IL-4, or IL-10. Intragraft expression of IL-7 mRNA and TGF-beta 1 mRNA was also investigated. Our investigation demonstrated that: (a) intragraft expression of IL-10 mRNA and IL-2 mRNA are significant correlates of acute rejection; (b) IL-4, IL-7, IFN-gamma and TGF-beta 1 mRNA expression do not correlate with acute rejection; and (c) IL-10 does not prevent in vivo expression of IFN-gamma, IL-2, IL-7, or TGF-beta 1. Our studies identify, for the first time, a significant association between intragraft IL-10 mRNA expression and acute rejection, and suggest that treatment strategies capable of constraining IL-10 expression might be of value in the prevention of acute rejection.