Alkaloids of Dyera costulata

Six bisindole alkaloids have been isolated from the leaves of Dyera costulata (Apocynaceae). One is the known ochrolifuanine A and the others are the novel ochrolifuanines E and F, and the 18-dehydroochrolifuanines A, E and F.     

Multiple Bacteriocin Production by Leuconostoc mesenteroidesTA33a and Other Leuconostoc/Weissella Strains

Leuconostoc (Lc.) mesenteroides TA33a produced three bacteriocins with different inhibitory activity spectra. Bacteriocins were purified by adsorption/desorption from producer cells and reverse phase high-performance liquid chromatography. Leucocin C-TA33a, a novel bacteriocin with a predicted molecular mass of 4598 Da, inhibited Listeria and other lactic acid bacteria (LAB). Leucocin B-TA33a has a predicted molecular mass of 3466 Da, with activity against Leuconostoc/Weissella (W.) strains, and appears similar to mesenterocin 52B and dextranicin 24, while leucocin A-TA33a, which also inhibited Listeria and other LAB strains, is identical to leucocin A-UAL 187. A survey of other known bacteriocin-producing Leuconostoc/Weissella strains for the presence of the three different bacteriocins revealed that production of leucocin A-, B- and C-type bacteriocins was widespread. Lc. carnosum LA54a, W. paramesenteroides LA7a, and Lc. gelidum UAL 187-22 produced all three bacteriocins, whereas W. paramesenteroides OX and Lc. carnosum TA11a produced only leucocin A- and B-type bacteriocins. Received: 11 April 1997 / Accepted: 10 June 1997     

Diastereomers of thymidine 3'-O-(methanephosphonothioate): synthesis, absolute configuration and reaction with 3'-methoxyacetylthymidine under conditions of triester approach to oligonucleotide synthesis

Diastereomers of the title compound were obtained and absolute configuration was assigned by means of stereochemical correlation. Their reaction with 3'-O-methoxyacetylthymidine in the presence of triisopropylbenzenesulphonyl (4-nitro) triazole is neither chemo- nor stereo-selective and leads to diastereomeric pairs of dithymidyl (3',5')methanephosphonate and -methanephosphonothioate. Obtained results are discussed in terms of mechanism of activation of phosphodiesters under conditions known as "phosphotriester approach to oligonucleotide synthesis".     

Isolation and chromosomal localization of the human glutathione peroxidase gene

We have isolated cDNA clones for the gene, termed GPX1, encoding the major human selenoprotein, glutathione peroxidase. Sequence analysis confirmed previous findings that the unusual amino acid seleno-cysteine is encoded by the opal terminator codon UGA. Southern blot analysis of human genomic DNA with the GPX1 cDNA showed that restriction endonucleases without sites in the probe sequence produced three hybridizing bands at standard stringency, diminishing to one strongly and one weakly hybridizing band at high stringency. In situ hybridization localized the human GPX1 gene to a single site on chromosome 3, at region 3q11-13.1. Thus, three genomic sites bear sequence homology to the GPX1 cDNA, and the one most homologous maps to 3q11-13.1.     

The effect of beta-estradiol, progesterone and testosterone on the production of human leukocyte derived interferons

Sex hormones including estrogens, progesterone and testosterones are known to have adverse effects on the immune system and particularly on the proliferative response. Since cytokine production is known to be dissociable from the proliferation of lymphocytes and since other steroid hormones profoundly affect cytokine production, we felt it would be important to know the effect of sex steroids on the production of interferons (IFN), particularly since the latter are known to be key substances in the immune response. We have shown estradiol can slightly reduce gamma IFN yields with certain inducers (Con A, SEA) but only in pharmacologic concentrations. Similarly, progesterone had a modest effect in the same concentrations but only when Con A was the inducer. Testosterone did not effect IFN titers at any concentration. None of the sex steroids affected alpha IFN production and none of them influenced the bioactivity of either IFN species. In all cases these hormones diminished proliferative responses as has been previously noted.     

Effect of individual and group rearing on age and size at maturity of male mosquitofish, Gambusia affinis

Age and size at sexual maturity were significantly greater for male mosquitofish, Gambusia affinis Baird and Girard, reared in sib-groups than for their sibs reared individually. Age at sexual maturity averaged 43.3 and 62.1 days for individually- and group-reared males, respectively, a 43% difference; final length and weight at maturity were 7.7 and 34.2% greater, respectively, for group-reared males than for their individually-reared sibs. The results were consistent among 30 families that represented the progeny of 30 wild-caught females. The observed differences may be attributable to behavioural interactions affecting the neuroendocrine control of the maturation process, as suggested by previous studies of Xiphophorus .     

Thermography as a predictive tool for laser treatment of port-wine stains

The argon laser, which has been proven both useful and safe for port-wine stain therapy, interacts with the hemoglobin of the vessels. In a percentage of cases, this treatment is still inefficient, and there is a lack of correlation between these bad results and clinical or histologic criteria. Thermography, which explores the vascularization of the port-wine stain, leads us to consider port-wine stains from a physical point of view. This very simple test shows no correlation with the clinical parameters of port-wine stain but is closely related to the results obtained with laser therapy. It seems to be a good criterion to estimate the argon laser treatment prognosis.