Hepatitis B treatment: Lessons for the nephrologist.

Hepatitis B affects approximately 350 million people worldwide, and an estimated 1.25 million people in the United States. Although most people infected with the virus do not develop significant hepatic disease from hepatitis B, 15-40% will develop serious complications. These complications include cirrhosis, the development of hepatocellular carcinoma , and hepatic decompensation. Patients with renal failure have increased risk of acquiring the virus through blood transfusions and contact with bodily fluids at hemodialysis centers, and of developing complications from hepatitis B virus infection. Renal transplant patients are at increased risk for exacerbations of hepatitis B with immunosuppression. Thus, it is crucial for the nephrologist to have a clear understanding of the natural history and treatment of hepatitis B, both pre- and post-renal transplant.

Biodegradation of ortho-cresol by a mixed culture of nitrate-reducing bacteria growing on toluene.

A mixed culture of nitrate-reducing bacteria degraded o-cresol in the presence of toulene as a primary growth substrate. No degradation of o-cresol was observed in the absence of toluene or when the culture grew on p-cresol and 2,4-dimethylphenol. In batch cultures, the degradation of o-cresol started after toluene was degraded to below 0.5 to 1.0 mg/liter but continued only for about 3 to 5 days after the depletion of toluene since the culture had a limited capacity for o-cresol degradation once toluene was depleted. The total amount of o-cresol degraded was proportional to the amount of toluene metabolized, with an average yield of 0.47 mg of o-cresol degraded per mg of toluene metabolized. Experiments with [ring-U-14C]o-cresol indicated that about 73% of the carbon from degraded o-cresol was mineralized to CO2 and about 23% was assimilated into biomass after the transient accumulation of unidentified water-soluble intermediates. A mathematical model based on a simplified Monod equation is used to describe the kinetics of o-cresol degradation. In this model, the biomass activity toward o-cresol is assumed to decay according to first-order kinetics once toluene is depleted. On the basis of nonlinear regression of the data, the maximum specific rate of o-cresol degradation was estimated to be 0.4 mg of o-cresol per mg of biomass protein per h, and the first-order decay constant for o-cresol-degrading biomass activity was estimated to be 0.15 h-1.(ABSTRACT TRUNCATED AT 250 WORDS)