The microemulsion free-radical polymerization of styrene generates particles containing one or at most a few high molecular weight polymer chains. Space-filling considerations preclude such chains from adopting their random-coil conformation; rather, they adopt a highly compact globular conformation and below Te constitute essentially single-chain glasses. This paper reports apparent spectroscopic and thermal differences between single-chain and conventional multichain polystyrene glasses. FTIR measurements suggest that the conformational temperature of the single-chain glasses as prepared is higher than that for multichain glasses. DSC measurements on these same glasses displayed a first-order exotherm near to the conventional Te of polystyrene but thereafter exhibited behavior similar to the multichain samples. The results were explained in terms of the existence of nematic cohesional entanglements in polystyrene glasses.

The use of purified self-antigens can facilitate the further analysis of pathogenic mechanisms in autoimmunity (1, 2). This report describes the isolation of the nephritogenic antigen of anti-tubular basement membrane (a-TBM)l-induced interstitial nephritis.

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One hundred and eighteen missionaries working on 75 mission stations or hospitals in 24 sub-Saharan African countries provided information about their medical practice in the preceding year of 1981. Details were collected of the total number of patients seen and admitted during the year, and the number of cases of bloody diarrhoea, typhoid and inflammatory bowel disease. Over 1 million outpatients and about 190,000 inpatients were treated. These included 12,859 cases of bloody diarrhoea, of whom 1,914 had typhoid. Twenty-two cases of inflammatory bowel disease were also reported. Histological support was least available in West Africa and only 25% of hospitals had access to this facility. Nevertheless, the frequency with which inflammatory bowel disease was reported was very similar to that in South Africa. The differential diagnosis of inflammatory bowel disease in sub-Saharan Africa is difficult and limited by access to diagnostic facilities. It is likely to be some time before reliable estimates of the incidence and prevalance of Crohn’s disease and ulcerative colitis in the rural African population can be made.