Detection, by three techniques, of hepatitis B surface antigen (HBsAg) and determination of HBsAg and anti-HBs titres in patients with chronic liver disease.

The sensitivities of three technqiues used to detect serum hepatitis B surface antigen (HBsAg) were compared in 411 patients with various types of chronic liver disease. Counterimmunoelectrophoresis proved an unreliable test. Two haemagglutination technqiues were slightly less sensitive than radioimmunoassay but were more rapidly performed.

Improved technique for the analysis of amino acids and related compounds on thin layers of cellulose.XI. Direct, visual micro-method for investigating the primary structural sequence of collagen and other proteins.

The present paper describes a new variation of the "finger printing" technique for examining the primary structure of proteins. It is based on the production of a reproducible, partial acid hydrolysate consisting of amino acids and small peptides which are separated into compact spots by bi-dimensional thin-layer chromatography. The spots are characterized by ther Rf values and colour reactions with a variety of reagents.

Intrahepatic cholestasis in childhood.

The apparent well-being of some children who as neonates were believed to have obstructive jaundice prompted us to study the clinical course, histologic features and possible etiologic factors in 17 children with cholestasis in the neonatal period. During a follow-up period of five months to 22 years, all had signs of chronic cholestasis, but only four died (two from nonhepatic causes); the others live remarkably normal lives. Serial hepatic biopsies in 11 showed a variety of initial lesions, which progressed to hypoplasia of the intrahepatic bile ducts, increasing portal fibrosis and eventual cirrhosis.

A prospective controlled trial of azathioprine in primary biliary cirrhosis.

Between 1968 and 1974, azathioprine has been used in a controlled prospective trial to treat patients with symptomatic but precirrhotic primary cirrhosis. Forty-five patients were admitted, of whom 22 were given azathioprine in a dose of 2 mg per kg of body weight. During the 1st year, serum aspartate transaminase levels showed a significant change in favor of the treated group, but improvement did not continue.

Incidence and clinical significance of e antigen and antibody in acute and chronic liver disease.

"e" is a serum antigen associated with type-B hepatitis. It is found only in hepatitis B surface antigen (HBsAg) positive sera, but is antigenically distinct from HBsAg. e antigen was not detected in the serum of any of 99 cases of acute type-B hepatitis who recovered normally.

Improvements in the thin-layer chromatography of natural products. I. Thin-layer chromatography of the aflatoxins.

During the period which has elapsed since the aflatoxins were first isolated, one of the main problems has been the separation of the individual aflatoxins in pure form from aflatoxin-containing extracts. This separation has been best effected by thin-layer chromatography, and in this paper we describe how some of the difficulties may be overcome by using an appropriate combination of solvent system and silica gel preparation. For the examination of aflatoxin-containing extracts from the mycelia of Aspergillus flavus moulds, an initial freeze-drying step has been found to improve appreciably the quality of the chromatograms obtained.

An improved technique for the analysis of amino acids and related compounds on thin layers of cellulose. X. The characterization of some methionyl, phenylalanyl, tyrosyl and other peptides by thin-layer and ion-exchange chromatography.

This paper is a continuation of previous work (Parts VI, VIII, and IX) designed to identify small peptides in biological fluids by a combination of ion-exchange and thin-layer chromatography. Several series of peptides, mainly dipeptides, with methionine, phenylalanine, tyrosine, aspartic acid, serine, or glutamic acid as the N-terminal amino acid, have been examined.

The epidemiological importance of 'ay' and 'ad' subtypes of the HB-Ag.

The distribution of the subtypes ;ay' and ;ad' has been assessed in 159 hepatitis B antigen (HB-Ag) positive subjects with a variety of associated hepatic conditions. A specific subtype could not be correlated with any particular hepatic pathology when the whole group was considered. However, the distribution of these two subtypes did vary according to the geographical origin of the subject or infection, or the presumed route of infection, so that there was an apparent association of one subtype with a certain disease state.

Biological activity and electronic structure of the aflatoxins.

In theoretical studies of aromatic hydrocarbons, Pullman and Pullman (1969) used the molecular orbital method to correlate electronic structure with biological activity. They suggested that the interaction between carcinogens and their molecular receptors must occur through the K region of the carcinogenic molecule and involve a strong chemical binding of the type of an addition reaction. In the present work the electronic structures of aflatoxins B(1), G(1), 4-20 dehydro B(1) and of versicolorin A have been determined by the simple Hückel molecular orbital method using a computer, in order to see whether the correlation between electronic structure and biological activity is applicable to these compounds also.