Bacteriology of sickle-cell leg ulcers in the equatorial forest belt of South-Western Nigeria

Forty-one sickle-cell leg ulcer patients attending the haematology out-patient clinic of the University of Benin Teaching Hospital, Benin City, Nigeria were included in this study and had swabs taken for bacterial studies. Single bacterial isolates were more frequent (68%) than mixed isolates (22%). No growth was obtained in 10% of patients. The relative frequency of Staphylococcus aureus was 57%; and the next most frequent organism was Escherichia coli (17%). Coliforms were relatively less frequent. Salmonella species and anaerobes were not isolated. The high incidence of skin pathogens (90%) raises the possibility of a bacterial role in the prevention of healing of these ulcers. A case is made for the use of appropriate antibiotics in promoting early healing.     

The state of sulphydryl groups in proteins isolated from normal and cataractous human lenses

Individual crystallins, urea-soluble and urea-insoluble proteins were isolated from the nucleus and cortex of types I-IV cataractous lenses and normal lenses. The levels of protein sulphydryls (P-SH), disulphides (S-S), as well as surface (F-SH) and buried (S-SH) in these proteins were determined by reaction with 5, 5'-dithiotris- (2-nitrobenzoic acid) or performic acid oxidation followed by amino acid analysis. During nuclear colour development there is a progressive decrease in the sulphydryl content of the crystallins. In the nuclei of advanced cataractous lenses, the P-SH decreases to 10% of the levels found in the normal nucleus. Similar but smaller changes take place in the cortex. No specific changes were found between the crystallins, with the exception of beta S crystallin. The cysteine remains constant in all lens types suggesting no higher oxidation products are formed. There is a significant shift in the distribution of cysteine in the nucleus of type III and IV lenses. Urea-insoluble proteins are the predominant species, accounting for about 70% of the total cysteine pool. This is consistent with the accumulation of modified insoluble polypeptides during senile nuclear cataract formation.     

Increased prevalence of apolipoprotein E2 in patients with retinitis pigmentosa

Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP.