Biomedical subjects
Publications and source records attributed to R May.
Anti-Gerbich type anti-Ge3 antibodies were identified in the serum of a woman of mixed ethnic origin from Cape Town. The woman had type Ge:-2,-3 (Gerbich) red cells on which there was no evidence of weakened Kell antigens. Her red cells were also Dantu-positive.
The polymorphism of HLA-DR3 was investigated in families and unrelated individuals of three population groups: South African (SA) Negroes, Cape Coloureds and SA Caucasoids. Serological and restriction fragment length polymorphism (RFLP) analysis indicated that DR3 could be subdivided into DRw17 (previously DR3.1) and DRw18 (previously DR3.2). In contrast, the two-dimensional (2-D) gel electrophoresis patterns could not distinguish between the DRB1 gene products of the HLA-DRw17 and DRw18 cells. Two DRB3 variants, correlating with the T-cell defined specificities Dw24 and Dw25 were identified at the genomic and product level. Of ten haplotypes studied with the newly defined HLA-DRw18 specificity, all had the DRB3 RFLP pattern associated with Dw24. HLA-DRw17 was found in all three population groups tested, although in the SA Negroes HLA-DRw18 was the prevalent DR3 subgroup. This subgroup was also present in the Cape Coloureds but was absent in the SA Caucasoids tested. HLA-DRw18 forms part of the most characteristic SA Negro haplotype, Bw42, DQw4, Dw"RSH," while HLA-DRw17 is part of the classic Caucasoid haplotype, B8, DQw2, Dw3.
The HLA antigen Aw43 has been observed only in Southern African populations. In order to confirm its identity and clarify its definition, ten cells with this specificity were shipped to laboratories in England, the United States of America and Australia to be tested with the sera from the 10th International Histocompatibility Workshop. The results of tests on nine of these cells which were sufficiently viable indicated that HLA-Aw43 is a distinct serological specificity which could be distinguished from both the A10 cross-reacting group (A25, A26 and Aw34) and A29. The Aw43 specificity segregated in two South African Negro families, and occurred commonly in association with Bw70. The occurrence of HLA-Aw43 in South African Caucasoids, in contrast to its absence in other Caucasoid groups, is probably due to genetic admixture with indigenous South African populations.
Experiments were designed to test the hypothesis that the pineal gland mediates the effects of changing day length and thereby synchronizes implantation within the population of spotted skunks. Intact, sham-superior cervical ganglionectomized (SCGx), SCGx, and SCGx/bilateral orbitally enucleated (B1) pregnant skunks were subjected to a natural photoperiod, and the duration of the preimplantation period was monitored. In a second set of experiments, melatonin was administered to pregnant skunks via two methods to determine whether or not this pineal hormone would mimic the effects of short day photoperiods or B1 on duration of the preimplantation period. Bilateral SCGx, which presumably denervated the pineal, had no effect on the average duration of the preimplantation period (232 +/- 57 vs. 199 +/- 6 days). However, SCGx reversed the inhibitory effect of B1 on implantation as SCGx/B1 animals had an average duration of the preimplantation period that was not significantly different from intact controls (262 +/- 46 vs. 214 +/- 11 days) but was significantly shortened in comparison to enucleated animals (262 +/- 46 vs. 316 +/- 45 days). Melatonin significantly lengthened the duration of the preimplantation period in animals receiving either daily afternoon injections of melatonin or those receiving melatonin Silastic capsule implants. These results are consistent with the hypothesis that the pineal gland synchronizes photoperiod-induced blastocyst implantation in the western spotted skunk.
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The western spotted skunk has a well-developed retinohypothalamic tract projecting to the middle and caudal parts of the suprachiasmatic nuclei. The nuclei have a complex 3-dimensional shape and contain small neuronal somas.
The growth of all children from one referral centre alive and well more than three years following the diagnosis of malignancy was analysed. Those treated with chemotherapy alone showed significant catch up growth. Children treated with chemotherapy and spinal irradiation showed no overall height loss, but manifested significant reduction in sitting height. Those treated by cranial irradiation had a significant height loss in the first year from which no catch up growth occurred and also had significantly reduced sitting height.
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Anal fissures are both common and disabling. Patients can be in pain for weeks before receiving effective treatment, and unnecessary discomfort may be prevented by timely operation. Existing forms of treatment are reviewed with particular reference to lateral subcutaneous sphincterotomy.
Two hundred and thirty six children with untreated lymphoblastic leukaemia were compared for height with the normal population by calculation of their mean standard deviation score. As a group, they proved to be significantly taller (P less than 0.0001), which gives support to the theory that growth hormone or a somatomedin may be involved in the development of the disease.
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The antifungal activity of a new topical imidazole, bifonazole (BAY h 4502, Bayer AG Institute for Chemotherapy), was compared in vitro with that of clotrimazole (BAY b 5097, Schering Corporation) in tests with 67 pathogenic and commensal yeasts, 45 dermatophytes and 14 miscellaneous pathogenic fungi by an agar dilution method. Three media, Kimmig's agar, Sabouraud's agar, and casein-yeast extract-glucose agar were used. Bifonazole was inhibitory for nearly all the yeasts tested including Candida albicans, C. parapsilosis, and Torulopsis glabrata with geometric mean minimal inhibitory concentrations (G-MIC) averaging 5 micrograms ml-1 on all three media. Clotrimazole was the more active drug against these same species with G-MIC's ranging from 0 . 25 to 2 . 10 micrograms ml-1. Results with bifonazole were affected by choice of medium with Kimmig's agar generally giving the lowest MIC's; results with clotrimazole were also affected by choice of medium but to a lesser degree. In nearly all instances, both bifonazole and clotrimazole were inhibitory for the dermatophytic fungi at concentrations of 0 . 50 micrograms ml-1 or less and clotrimazole was the more active drug. Choice of medium was, in general, not a factor with these latter fungi which included Epidermophyton, Trichophyton, and Microsporum species. Both drugs were active against species of Aspergillus (G-MIC's of 3 . 18 micrograms ml-1), Fusarium (G-MIC's ranging from 1 . 59 to 12 . 70 micrograms ml-1) and Scopulariopsis (G-MIC's of 1 . 78 micrograms ml-1); clotrimazole was the more active drug by factors of 2- to 4-fold on all three media. Bifonazole MICs were shown to vary with pH (maximal activity at pH 6 . 5) with selected yeasts when tested on Kimmig's agar. Differences in results obtained with varying inoculum sizes for these same yeasts generally were unremarkable. With selected species of yeasts and dermatophytes, it was determined that the ratio of minimal fungicidal to inhibitory concentrations (MFC/MIC) was much lower for bifonazole than for clotrimazole.
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The concentrations of volatile hydrocarbons were studied in breath samples from patients before and after anaesthesia. In patients to whom halothane was administered, there was a significant increase in the concentration of isobutene (from 0.43 +/- 0.09 to 4.66 +/- 2.22 nmol litre-1). There was no change in the concentration of isobutene in six patients anaesthetized with ketamine and diazepam. The concentrations of ethane and pentane were not altered significantly in either group.