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991.
Semen manipulation: improved sperm recovery and function with a two-layer Percoll gradient 总被引:6,自引:0,他引:6
The authors compared a simple, two-layer Percoll density gradient technique with the swim-up technique for semen preparation in 128 men. In samples from normospermic (n = 55), oligospermic (n = 26), and asthenospermic (n = 29) men, the Percoll technique significantly improved yield, percent motility, and absolute number of motile sperm recovered, but in samples from oligoasthenospermic men (n = 18), only percent motility was improved. The Percoll density gradient also selected sperm with markedly improved function as assessed by both the sperm penetration assay and the fertility index. In 37 samples negative on the sperm penetration assay when processed with the swim-up technique, 19 (51%) became positive when processed with the Percoll technique. The Percoll density gradient is an improved method for semen manipulation as it allows greater recovery of sperm with higher motility and improved sperm function. 相似文献
992.
993.
994.
Estrogen has received considerable attention recently as a potential therapeutic agent in vascular pathophysiological states such as stroke. The mechanisms by which estrogen influences cerebral arteries are incompletely understood. The present study was to examine the effect of ovariectomy and chronic estrogen or tamoxifen treatment on vascular reactivity in rat posterior communicating cerebral arteries with intact endothelium. Changes in vascular tension were measured by microvessel myograph. Ovariectomy significantly enhanced the constricting responses to endothelin I, but not to phenylephrine. Chronic treatment with estrogen or tamoxifen partially reversed or abolished the effect of ovariectomy. The contraction induced by high K+ solution was also enhanced in the ovariectomized rats and this enhancement was abolished by estrogen or tamoxifen treatment. Ovariectomy potentiated the relaxant response to nicardipine but not NS 1619. Estrogen but not tamoxifen reversed the effect of ovariectomy. The present results indicate that chronic tamoxifen may not act as an antagonist of estrogen, instead, chronic treatment with estrogen and tamoxifen has similar effect in inhibiting the increased vascular tension induced by ovariectomy. This study suggests the influence of physiological level of estrogen on vascular contractility. It is at present unknown what may have caused increased relaxant effect of nicardipine, a L-type Ca2+ channel blocker. More experiments are needed to show the role of endothelium in the altered vascular contractility in the ovariectomized and estrogen-treated rats. (supported by UPGC Direct Grant). 相似文献
995.
996.
997.
Membranous duodenal stenosis 总被引:1,自引:0,他引:1
C Mikaelsson E Arnbjörnsson CM Kullendorff 《Acta paediatrica (Oslo, Norway : 1992)》1997,86(9):953-955
The experience of our 16 patients treated for membranous duodenal stenosis is reported. Their treatment and course was analysed in a retrospective study. Eight patients were operated on within the first 16 days of life and in the remaining group surgery was performed at 1 month to 4 y of age. The presenting symptom leading to diagnosis was, in all but one case, non-bile-stained vomiting. Associated malformations were found in all but four patients, mostly morbus Down. The operative procedure performed was a partial excision of the duodenal membrane and a duodenoplasty in 10 patients, a duodenojejunostomy in 5 patients, and a duodenoplasty only in 1 patient. The postoperative course was without lethal complications. One late stricture in an anastomosis occurred. We conclude that in its presentation, duodenal stenosis differs from duodenal atresia, and can often be misinterpreted, resulting in a late diagnosis, and should be reported as a separate entity. 相似文献
998.
Vos Q; Ortaldo JR; Conan-Cibotti M; Vos MD; Young HA; Anderson SK; Witherspoon K; Prager I; Snapper CM; Mond JJ 《International immunology》1998,10(8):1093-1101
NK cells not only function as cytotoxic effector cells, but also have
immunoregulatory roles including the enhancement of Ig secretion. To have a
stable and uniform population of NK cells to study their role in Ig
secretion, we generated murine NK clones. Thus, culture of splenocytes from
mice that were homozygous for a mutation in the p53 tumor suppressor gene
(p53-KO) with IL-2 and poly(IC) resulted in a long-term NK line, from which
four stable clones were derived. This approach also yielded a long-term NK
line from splenocytes of normal C57BL/6 mice. Identification of the clones
as members of the NK lineage was based on large granular morphology,
expression of NK-TR and absence of TCR gene rearrangement. Flow cytometry
revealed that all clones expressed IL-2R alpha and beta, chains and B220,
but no CD3, NK1.1, DX5 or Ly-49. RT-PCR analysis showed heterogeneity in
NK1.1 gene expression, and demonstrated expression of perforin and several
granzymes in all clones. Three out of four clones lysed YAC-1, but not P815
target cells, corresponding to a pattern of NK specificity. All NK clones
enhanced Ig secretion in an in vitro model for T cell- independent type 2
antigens, albeit to varying degrees. We found no correlation between the
degree of helper activity of the NK clones and the level of their cytotoxic
activity on YAC-1 targets. Thus, we established murine NK clones, and show
that they mediate both cytotoxicity and enhancement of Ig secretion.
相似文献
999.
1000.
H.P. STEVENS L.S. OSTLERE CM. BLACK M.H.A. RUSTINA 《The British journal of dermatology》1993,129(4):455-457
We report a patient with generalized morphoea secondary to porphyria cutanea tarda. who responded to treatment with cyclosporin. The differences between the sclerodermatous skin changes seen in porphyria cutanea tarda and generalized morphoea are discussed. 相似文献