Blood alcohol levels (BAL) were maintained at high levels (overall mean +/- S.D. achieved in 14 alcoholic rats was 216.0 +/- 120.1 mg%) in male Wistar rats for 15 to 85 days by continuous intragastric infusion of ethanol and nutritionally defined low fat liquid diet. The ethanol intake was progressively increased from 32% of total calories up to 41.4% in order to maintain high BAL. Pair-fed animals received isocaloric glucose solution and the liquid diet. Despite the low level of dietary fat (4.9% of total calories), histopathological evaluation of the liver revealed severe and progressive fatty infiltration in the alcoholic rats. In addition, following 30 days of intoxication, one third of the animals showed focal necrosis with mononuclear cell infiltration in centrilobular areas of the livers. This was correlated with the markedly elevated levels of SGOT and SGPT in these animals. Pair-fed controls showed no abnormality in the morphology of liver or blood chemistry. Chemical quantitation of liver triglycerides confirmed the histological observation, with triglyceride levels of 61.51 +/- 16.45 and 89.61 +/- 5.94 mg per gm at 30 and 85 days, respectively. Most importantly, the degree of steatosis was tightly and significantly correlated with the mean BAL achieved (r = 0.80, p less than 0.001). These data represent the first confirmation of the hypothesis that continuously high BAL correlate with the severity of alcohol-induced liver pathology.

Synthesis of an operon fusion protein was investigated in batch and fed-batch cultures at high cell densities of recombinant Escherichia coli JM105 [pBAD-GFP::CAT]. Glucose-limited growth was achieved without accumulation of inhibitory byproducts allowing high cell densities (110 g L(-1) DCW) to be attained. This was believed to be the highest reported value for dry cell mass of E. coli strain JM105 expressing two recombinant proteins. Transcription of the two reporter genes, green fluorescent protein (GFP) and chloramphenicol acetyltransferase (CAT), was under the control of the p(BAD) promoter of the araBAD (arabinose) operon. Each protein was independently translated via separate ribosome binding sites. CAT served as a model recombinant protein product to illustrate the noninvasive quantitative reporting ability of GFP during high cell density fermentations. Expression of GFP was monitored on-line using an intensity-based optical sensor. A linear correlation between the on-line GFP intensity and the enzymatic activity of CAT allowed for in vivo real-time quantitative monitoring of a fermentation product under conditions of high biomass concentration and high productivity.