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排序方式: 共有245条查询结果,搜索用时 15 毫秒
1.
Calcium ionophore-induced acrosome reaction correlates with fertilization rates in vitro in patients with teratozoospermic semen 总被引:5,自引:3,他引:5
The aim of this study was to determine the relationship between calcium
ionophore A23187-induced acrosome reaction (AR) and sperm fertilizing
ability. Semen samples remaining after preparation for standard IVF were
studied in 109 patients who had sperm concentrations > or =20 x
10(6)/ml. Ionophore-induced AR was performed on motile spermatozoa selected
by centrifugation on a Percoll gradient. Semen analysis was performed using
standard methods. Patients with higher (>50%, n = 76) fertilization
rates had significantly higher ionophore-induced AR than patients with
lower (<50%, n = 33) fertilization rates (49 +/- 14 versus 38 +/- 21%, P
< 0.05). When the data from all patients were analysed by logistic
regression, only the percentage sperm motility in insemination medium and
ionophore-induced AR were significantly related to fertilization rates.
Similar results were also obtained when the data from a subgroup of
patients with poor (<15% normal) sperm morphology were analysed.
However, when patients with normal sperm morphology > or =15% were
analysed separately, only sperm count and the percentage of spermatozoa
with progressive motility in semen were significantly related to
fertilization rates. In conclusion, ionophore- induced AR was significantly
related to fertilization rates in vitro mainly in patients with
teratozoospermic semen. Tests for ionophore- induced AR may provide
additional information about sperm fertilizing ability but may not indicate
specific defects of the physiological AR.
相似文献
2.
Stein TP; Oram-Smith JC; Leskiw MJ; Wallace HW; Long LC; Leonard JM 《The American journal of physiology》1976,230(5):1321-1325
3.
Interchromosomal duplications of the adrenoleukodystrophy locus: a phenomenon of pericentromeric plasticity 总被引:13,自引:5,他引:13
Eichler EE; Budarf ML; Rocchi M; Deaven LL; Doggett NA; Baldini A; Nelson DL; Mohrenweiser HW 《Human molecular genetics》1997,6(7):991-1002
A 9.7 kb segment encompassing exons 7-10 of the adrenoleukodystrophy (ALD)
locus of the X chromosome has duplicated to specific locations near the
pericentromeric regions of human chromosomes 2p11,10p11, 16p11 and 22q11.
Comparative sequence analysis reveals 92-96% nucleotide identity,
indicating that the autosomal ALD paralogs arose relatively recently during
the course of higher primate evolution (5-10 million years ago). Analysis
of sequences flanking the duplication region identifies the presence of an
unusual GCTTTTTGC repeat which may be a sequence-specific integration site
for the process of pericentromeric- directed transposition. The breakpoint
sequence and phylogenetic analysis predict a two-step transposition model,
in which a duplication from Xq28 to pericentromeric 2p11 occurred once,
followed by a rapid distribution of a larger duplicon cassette among the
pericentromeric regions. In addition to facilitating more effective
mutation detection among ALD patients, these findings provide further
insight into the molecular basis underlying a pericentromeric-directed
mechanism for non- homologous interchromosomal exchange.
相似文献
4.
Clarke GN; Bourne H; Hill P; Johnston WI; Speirs A; McBain JC; Baker HW 《Human reproduction (Oxford, England)》1997,12(4):722-726
Donor insemination (DI) using cryopreserved semen commenced at The Royal
Women's Hospital in 1976. Over the next 15 years we performed 5953
treatment cycles to achieve 816 pregnancies (13.7% per cycle) and 706 live
births. In-vitro fertilization (IVF) using donor spermatozoa commenced in
1986. Over the next 5 years we performed 303 treatment cycles for 185
couples. Including subsequent transfer of cryopreserved embryos, a total of
33% of couples achieved a successful pregnancy by IVF. Statistical analysis
indicated that, for DI pregnancies, the most important semen variable was
the percentage post-thaw motility, whilst for normal fertilization in IVF
it was the pre-freeze motility. These results may be explained by the
compensatory effects of post-thaw processing of spermatozoa for IVF, but
not for DI in our clinic.
相似文献
5.
Jiang WZ Jin NY Li ZJ Zhang LS Wang HW Zhang YJ Han WY 《第二军医大学学报》2006,27(4):434-434
To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1 (CN)) in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA (1.3 kb) was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows: BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting. 相似文献
6.
7.
The multifunctional US3 protein kinase is conserved among alphaherpesviruses. Like the herpes simplex virus US3 protein kinase, the pseudorabies virus (PRV) US3 protein confers resistance against apoptosis. In the current report, we introduced a point mutation in the putative ATP binding site of the PRV US3 protein kinase. We found that, in contrast to the wild type PRV US3, the point-mutated PRV US3 does not protect cells from apoptosis induced by PRV infection or staurosporine treatment. In addition, we found that the presence of wild type PRV US3, but not of the point-mutated PRV US3, results in phosphorylation of the pro-apoptotic Bad protein in PRV-infected ST and HEp-2 cells. In PRV-infected ST cells, but not in HEp-2 cells, an additional, US3- and phosphorylation-independent alteration of Bad could be observed. These results suggest that the kinase activity of the US3 protein of PRV is crucial to protect cells from apoptotic cell death during infection, at least partly by leading to phosphorylation of the pro-apoptotic Bad protein. 相似文献
8.
Leontien Van Wely Jeannette C Boiten John Verhoef Belinda HW Eijckelhof Susanne M Van Hooft AnneLoes Van Staa 《Physiotherapy theory and practice》2019,35(4):318-326
Self-management support programs are reported to have positive effects on the health and care of people with physical disabilities. It is unclear how physiotherapists (PTs) view self-management support. A cross-sectional study with mixed-methods design using Q-methodology was conducted to determine the perspectives of Dutch PTs on self-management support. PTs (n = 39) rank-ordered 37 validated statements about self-management support from “most disagree (?3)” to “most agree (+3).” Differences in perspectives on self-management support were explored in a by-person centroid factor analysis on the basis of the explained variance (R2). After having sorted the statements, PTs explained their ranking of ?3 and +3 statements in semi-structured interviews. All PTs recognized self-management support as intrinsic part of physiotherapy practice. Nevertheless, four particular perspectives could be identified: (1) the “externally driven educator” (R2 = 14%), (2) “internally driven educator” (R2 = 9%), (3) “client-centered coach” (R2 = 13%), and (4) “client-initiated coach” perspective (R2 = 15%). Each perspective reflects particular goals and perceptions of self-management support. Differences were identified with respect to the PTs’ role perception (educating or coaching), drive (external or internal), and collaboration with the patient (as partner or not). The identified perspectives can be used in the physiotherapy education curriculum to create awareness about the various ways of practicing self-management support and the skills needed to be able to tailor support to patient needs and to switch between perspectives. 相似文献
9.
Proliferation and cytogenetic analysis of hairy cell leukemia upon stimulation via the CD40 antigen 总被引:2,自引:0,他引:2
Kluin-Nelemans HC; Beverstock GC; Mollevanger P; Wessels HW; Hoogendoorn E; Willemze R; Falkenburg JH 《Blood》1994,84(9):3134-3141
Using the CD40 system, in vitro proliferation of hairy cell leukemia (HCL) was examined in 43 patients. In this culture system, cells were stimulated by interleukin-4 (IL-4) and anti-CD40 monoclonal antibodies (MoAbs) that were added in soluble form or were cross-linked via their Fc part using Fc gamma RII-transfected mouse fibroblast cells. Proliferation was induced and confirmed by 3H-thymidine incorporation in 14 cases and by the presence of metaphases in 42 cases. 3H-thymidine incorporation showed a heterogeneous pattern: cross-linking of anti- CD40 gave the highest proliferation in 8 cases; in 11 cases, stimulation with anti-CD40 MoAbs alone, without cross-linking also resulted in proliferation; the addition of IL-4 further enhanced 3H- thymidine incorporation in 5 cases, but suppressed this phenomenon in 5 other cases. The CD40 system proved to be very effective in obtaining cytogenetic data. With a success rate of 42 of 43 patients tested, we found clonal abnormalities in 8 cases (19%) and nonclonal abnormalities with involvement of one or two abnormal metaphases in another 7 cases. The chromosomes most frequently involved in the abnormal karyotypes, both structurally and numerically, were chromosomes 5, 7, and 14. By fluorescence-activated cell-sorting analysis of the cultured cells, and by immunophenotypic analysis of metaphase spreads, T-cell growth could be excluded and the HCL-lineage confirmed. Stimulation via the CD40 antigen is an excellent tool for growing hairy cell leukemia cells. 相似文献
10.
目的:研究胰腺内分泌肿瘤的胃肠多肽受体表达状况。方法:采用储磷放射自显影技术显示和定量分析胰泌素、蛙皮素、肠血管活性多肽、胆囊收缩素、生长抑素受体在胰腺内分泌肿瘤的表达特征。结果:胃泌素瘤表达蛙皮素、生长抑素受体,胰泌素和肠血管活性多肽受体,其中生长抑素受体亲和力及结合能力显高于其它受体。肠血管活性多肽瘤表达生长抑素,肠血管活性多肽和B型胆囊收缩素受体,以B型胆囊收缩素受体亲和力及结合能力最高。胃泌素瘤或VIP瘤所表达的胰泌素、蛙皮素、肠血管活性多肽、胆囊收缩素和生长抑素受体均呈高亲和力、单结合位点特征。生长抑素瘤和胰高糖素瘤未能测得上述5种胃肠多肽受体。结论:除生长抑素受体外,胃泌素瘤和肠血管活性多肽瘤还表达胰泌素、蛙皮素、肠血管活性多肽受体。 相似文献