Regulation of human immunodeficiency virus env expression by the rev gene product.

A single simian virus 40 late replacement vector which expresses both the rev and envelope (env) genes of human immunodeficiency virus was used to examine the mechanism underlying the dependence of env gene expression on the rev protein. When rev was deleted from the vector, no envelope protein expression could be detected in transfected cells, and the levels of cytoplasmic env mRNA were dramatically reduced. In contrast to this, the levels of env RNA in total cellular RNA preparations were similar with or without rev coexpression, and analysis of nuclear RNA showed that the levels of nuclear env RNA were increased in the absence of rev. These results suggest that rev functions to regulate nuclear export of env mRNA. It was possible to restore env expression from the vector lacking rev by supplying rev in trans, provided that a cis-acting sequence was also present. This sequence was mapped to a 854-base-pair region within the env open reading frame, and it was shown that the sequence could be moved but that it worked only in its original orientation.

Urinary excretion of bile alcohols in normal children and patients with alpha 1-antitrypsin deficiency during development of liver disease.

Healthy infants and children were found to excrete bile alcohol glucuronides in urine. Following isolation and hydrolysis, the bile alcohols were estimated by capillary gas-liquid chromatography. The daily urinary excretion of the major compound, 27-nor-5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 24 xi, 25 xi-pentol (a C26 bile alcohol), ranged from 0.1 to 1.1 mumol/24 h per m2 body surface area for healthy infants and children. Two groups of patients with alpha 1-antitrypsin deficiency (phenotype PiZ) were also studied during infancy and childhood, and biochemical liver function tests and liver morphology were compared to the excretion of bile alcohols. The highest excretion of the C26 bile alcohol in urine was found in patients with alpha 1-antitrypsin deficiency and juvenile cirrhosis (2.1-8.4 mumol 24 h-1 m-2) regardless of preceding neonatal cholestasis. Patients with alpha 1-antitrypsin deficiency, neonatal cholestasis and subsequent fibrosis or normal liver morphology excreted bile alcohols within the normal range. The C26 bile alcohol constituted an average of 36% of the total bile alcohols in forty-three urine samples. This percentage was about the same in the three groups studied. The findings suggest that determination of urinary bile alcohols may be a valuable non-invasive diagnostic tool for patients with or at risk of developing liver cirrhosis.