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911.
Albumin gradients do not enrich Y-bearing human spermatozoa 总被引:1,自引:0,他引:1
Flaherty SP; Michalowska J; Swann NJ; Dmowski WP; Matthews CD; Aitken RJ 《Human reproduction (Oxford, England)》1997,12(5):938-942
The aim of this study was to evaluate objectively whether or not
discontinuous albumin gradients enrich the proportion of Y-bearing human
sperm. A blinded, collaborative trial design was employed whereby a
licensed centre prepared the sperm fractions using licensed procedures,
coded the sperm slides and then sent them to an independent laboratory for
determination of the X:Y ratio in each sperm fraction using X and Y
chromosome-specific probes and double label fluorescence in-situ
hybridization (FISH). The identification codes and FISH results were
collated by an independent third observer. Two albumin gradient methods
which are currently used by licensed centres for male sex pre- selection,
protocol 3 and modified protocol 3, were tested. Essentially the same
results were obtained for the two methods. Highly motile sperm fractions
were recovered from the albumin gradients, and the recoveries of motile
spermatozoa (1.3-8.5%) were within the optimal range reported to produce
maximal enrichment of Y-bearing spermatozoa. FISH analysis, however,
revealed no enrichment for Y-bearing spermatozoa with either method, and
the overall X:Y ratios were not significantly different from 1.0. Some
samples showed marginal enrichment of Y-bearing spermaotozoa, whereas
others showed marginal enrichment of X-bearing spermaotozoa. In conclusion,
this collaborative study has demonstrated that the protocol 3 and modified
protocol 3 albumin gradient procedures do not enrich Y-bearing spermatozoa.
The clinical use of albumin gradients for male sex preselection should be
reconsidered in the light of this and other evidence.
相似文献
912.
癌化学预防药物的研究:一些酰胺化合物的合成袁占亮,徐世平(中国医学科学院,中国协和医科大学药物研究所北京100050)维甲类化合物的合成及生物活性研究,引起国内外学者的很大兴趣,尤其是对癌的化学预防方面的研究方兴未艾,是国际上公认为最成熟和最有希望的... 相似文献
913.
914.
Chloroquine, a well-known anti-malarial and anti-inflammatory agent, was studied with respect to its effect on the serum complement system. The drug exhibited significant in vitro anti-complementary activity only at a very high non-therapeutic dose of 48 mg/ml. Chloroquine-induced in vitro complement consumption was observed to take place even in the absence of Ca2+ and Mg2+ ions. The drug also haemolyses rabbit erythrocytes in the presence of Mg2+-EGTA and immunoelectrophoretic studies of fresh human serum and chloroquine incubation mixture against specific anti-C3 and anti-factor B antisera have demonstrated that it cleaves both C3 and factor B. In another experiment, chloroquine failed to exert inhibitory effects on complement utilisation by immune complexes. Studies of the serum complement profile of Plasmodium falciparum-infected malaria patients receiving chloroquine therapy indicated that, in contrast to the situation in vitro, the serum C3 level is invariably decreased. Marginal reductions in the levels of C4, factor B and properdin were also found in some of these patients, while administration of chloroquine to normal human individuals failed to produce any significant change in their serum complement profile. It is, therefore, probable that malarial parasites and not chloroquine are responsible for complement activation in patients suffering from malaria. 相似文献
915.
916.
917.
918.
Adriamycin and daunomycin produce dose-related cardiac toxicity that may be related to oxygen radicals. Addition of these compounds to human erythrocyte suspensions resulted in stimulation of hexose monophosphate shunt activity that was markedly impaired in the absence of oxyhemoglobin. Evidence for generation of hydrogen peroxide by these compounds was provided by oxidation of reduced glutathione, by 14C- formate oxidation, and by the catalase-aminotriazole trapping technique. These experiments indicate that Adriamycin and daunomycin interact with oxyhemoglobin to generate reactive oxygen metabolites. A similar interaction with oxymyoglobin may occur in the heart and produce oxygen radicals that injure cardiac myocytes. 相似文献
919.
The study was made with the help of a chemitrode placed in various areas of the hypothalamus by the stereotaxic technique, for electrical and chemical stimulation (noradrenaline or isoprenaline) before and after microinjection of respective blockers (phenoxybenzamine or practalol). The results indicated the presence of both alpha and beta-adrenoreceptors in the anterior and dorsomedial hypothalamus producing a depressor response, and, the presence of alpha adrenoreceptors in the posterior and lateral hypothalamus producing a pressor response. 相似文献
920.