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排序方式: 共有222条查询结果,搜索用时 15 毫秒
1.
Van de Velde H; De Vos A; Joris H; Nagy ZP; Van Steirteghem AC 《Human reproduction (Oxford, England)》1998,13(11):3160-3164
In human in-vitro fertilization (IVF), the oocytes are surrounded by
cumulus and corona cells at the time of insemination so that their maturity
cannot easily be evaluated. The best IVF results are obtained if the
oocytes are inseminated 2-6 h after retrieval. In the intracytoplasmic
sperm injection (ICSI) procedure, the oocytes are denuded by enzymatic and
mechanical treatment in order to be able to perform the injection. As a
consequence, the nuclear maturity of the oocytes can be evaluated and only
those that have extruded the first polar body are injected. However,
metaphase-II oocytes that have not yet reached cytoplasmic maturity cannot
be recognized. The purpose of this study was to investigate the effect of
different timing of cumulus- corona cell removal and injection on the
outcome of ICSI. For this we allowed the oocytes to complete in-vitro
cytoplasmic maturation in two different culture conditions: (i) surrounded
by their cumulus and corona cells or (ii) totally denuded. We performed
three different studies on sibling oocytes obtained after a standardized
buserelin/human menopausal gonadotrophin (HMG) protocol. We investigated
the effect of early (1-2 h after retrieval) and late (5-6 h after
retrieval) oocyte denudation and injection on the survival and
fertilization of the injected oocytes and on embryo cleavage after
fertilization. We found no statistically significant differences between
early and late injection, indicating that after a standardized
buserelin/HMG protocol the metaphase-II oocytes do not need time for
further cytoplasmic maturation. Furthermore, a different timing of
cumulus-corona cell removal has no effect on the outcome of ICSI,
suggesting that the surrounding cells are not necessary for survival,
fertilization and cleavage after ICSI.
相似文献
2.
Percoll gradient centrifugation can be omitted in sperm preparation for intracytoplasmic sperm injection 总被引:4,自引:3,他引:4
De Vos A; Nagy ZP; Van de Velde H; Joris H; Bocken G; Van Steirteghem A 《Human reproduction (Oxford, England)》1997,12(9):1980-1984
Prior to intracytoplasmic sperm injection (ICSI), seminal fluid is
currently washed out from the ejaculated semen and further sperm selection
is carried out by a discontinuous Percoll gradient. Possible deleterious
effects from the sperm-separating substance Percoll on sperm function or
embryo cleavage after in-vitro fertilization (IVF) have, to our knowledge,
not yet been reported and the use of Percoll has been widely accepted in
IVF. In this study, we examined whether the omission of the Percoll step in
the sperm preparation has any influence on the outcome of the ICSI
procedure. Two methods of sperm preparation for ICSI were compared in a
controlled study on sibling oocytes: washing the semen sample once,
followed by a Percoll gradient centrifugation versus washing the sperm
sample twice without a Percoll gradient centrifugation. The mean
fertilization rates were similar for the two sperm preparation methods:
78.2 +/- 21.4 and 75.0 +/- 24.1% respectively of the intact oocytes
displaying two pronuclei. Cleavage rates did not differ statistically
between the two groups. Whereas in both groups similar percentages of
excellent, good and poor quality embryos were obtained, the percentage of
fair quality embryos was significantly higher in the group without Percoll
(16.3 +/- 20.1 versus 9.1 +/- 15.7%). However, no statistical differences
were observed in either the percentage of transferable embryos or in the
percentage of embryos actually transferred or frozen in the two groups. In
conclusion, spermatozoa from ejaculates that are washed out from the
seminal fluid without any further selection can be used for ICSI without
any adverse effect on fertilization and embryo cleavage.
相似文献
3.
E A Dellers P T Valente P R Edmonds G Balsara 《Archives of pathology & laboratory medicine》1991,115(9):918-920
Mixed mesodermal tumors are uncommon outside the uterus. Nine extrauterine mixed mesodermal tumors (eight ovarian and one extragenital) were selected for histochemical and immunoperoxidase study. In eight cases, both epithelial and mesenchymal elements were malignant (chondroid in six, rhabdomyoid in four, and osteoid in two). One ovarian tumor was an adenosarcoma. All cases were stained with periodic acid-Schiff with and without diastase and for alpha 1-antitrypsin, myoglobin, keratin, vimentin, muscle-specific actin, and alpha 1-antichymotrypsin, by using the avidin-biotin-immunoperoxidase method. The periodic acid-Schiff-positive, diastase-resistant droplets in several of the tumors showed peripheral alpha 1-antitrypsin positivity. Keratin delineated epithelial areas well in seven cases, and rhabdomyoid differentiation was confirmed with myoglobin in four cases. However, squamous elements in one tumor were falsely positive for myoglobin. We concluded that despite occasional cross-reactivity, carefully interpreted immunoperoxidase stains can be useful in distinguishing epithelial and mesenchymal elements in these tumors. 相似文献
4.
5.
Benjamin J. Kopecky Christian Frye Yuriko Terada Keki R. Balsara Daniel Kreisel Kory J. Lavine 《American journal of transplantation》2020,20(5):1225-1235
Since the 1960s, heart and lung transplantation has remained the optimal therapy for patients with end‐stage disease, extending and improving quality of life for thousands of individuals annually. Expanding donor organ availability and immunologic compatibility is a priority to help meet the clinical demand for organ transplant. While effective, current immunosuppression is imperfect as it lacks specificity and imposes unintended adverse effects such as opportunistic infections and malignancy that limit the health and longevity of transplant recipients. In this review, we focus on donor macrophages as a new target to achieve allograft tolerance. Donor organ‐directed therapies have the potential to improve allograft survival while minimizing patient harm related to global suppression of recipient immune responses. Topics highlighted include the role of ontogenically distinct donor macrophage populations in ischemia–reperfusion injury and rejection, including their interaction with allograft‐infiltrating recipient immune cells and potential therapeutic approaches. Ultimately, a better understanding of how donor intrinsic immunity influences allograft acceptance and survival will provide new opportunities to improve the outcomes of transplant recipients. 相似文献
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8.
目的:肝脏可溶性复合物具有保护肝脏、刺激肝组织再生等生物学活性,观察天然物质肝脏可溶性复合物对肿瘤细胞生长增殖的抑制作用.方法:实验于2006-05/2007-02在四川大学华西医院生物治疗国家重点实验室实验肿瘤研究室完成.①分离人胚胎、成年及新生小鼠肝脏组织,生理盐水清洗、剪碎、筛网过滤,用生理盐水制备混悬液,3 000 r/min离心,收集上清,制备肝脏可溶性复合物.②体外实验:用上述不同来源的肝脏可溶性复合物体外处理肿瘤细胞,四甲基偶氮唑盐比色法测定其对乳腺癌细胞EMT6增殖的影响.③体内实验:观察成年鼠肝脏可溶物质对乳腺癌细胞EMT6体内生长的抑制作用及其对荷瘤鼠生存状况的影响,包括不同给药剂量及不同给药途径两个实验,给药途径包括在接种肿瘤细胞部位的对侧腋下、同侧腋下、腹腔注射及灌胃等.结果:①体外实验显示不同来源的肝脏可溶性复合物能明显抑制肿瘤细胞EMT6增殖率,肿瘤增殖抑制率均显著高于血清白蛋白处理组(P<0.05),并呈剂量依赖性.②成年鼠肝脏可溶物质8mg/L组抑瘤率高于2,4 mg/L组(P<0.05),未观察到明显毒副效应.③比较不同给药途径,成年鼠肝脏可溶物质同侧注射组的抑瘤率较其他3组的抑瘤率高(P<0.05),各成年鼠肝脏可溶物质给予组的体质量增长率比相应生理盐水对照组高(P<0.05).④与相应生理盐水对照组比较,在同侧腋下注射成年鼠肝脏可溶物质的小鼠生存期明显延长(P<0.05).结论:肝脏可溶性复合物具有抑制肿瘤细胞生长的作用,并且呈一定的剂量依赖性.不同的给药途径中,在接种肿瘤细胞部位的同侧腋下给药抑瘤效果最好. 相似文献
9.
Nora Barboza Svetlana Minakhina Daniel J. Medina Binaifer Balsara Sonya Greenwood Lien Huzzy Arnold B. Rabson Ruth Steward Dale G. Schaar 《Cancer biology & therapy》2013,14(6):546-555
PDCD2 is an evolutionarily conserved eukaryotic protein with unknown function. The Drosophila PDCD2 ortholog Zfrp8 has an essential function in fly hematopoiesis. Zfrp8 mutants exhibit marked lymph gland hyperplasia that results from increased proliferation of partially differentiated hemocytes, suggesting Zfrp8 may participate in cell growth. Based on the above observations we have focused on the role of PDCD2 in human cancer cell proliferation and hypothesized that aberrant PDCD2 expression may be characteristic of human malignancies. We report that PDCD2 is highly expressed in human acute leukemia cells as well as in normal hematopoietic progenitors. PDCD2 knockdown in cancer cells impairs their proliferation, but not viability relative to parental cells, supporting the notion that PDCD2 overexpression facilitates cancer cell growth. Prospective analysis of PDCD2 in acute leukemia patients indicates PDCD2 RNA expression correlates with disease status and is a significant predictor of clinical relapse. PDCD2’s role in cell proliferation and its high expression in human malignancies make it an attractive, novel potential molecular target for new anti-cancer therapies. 相似文献
10.
1. Radio-ligand binding study has demonstrated that flunarizine has a high affinity for the rat striatal D 2 dopamine (DA) receptors. 2. In the present behavioural study conducted in rats it was observed that flunarizine, unlike the postsynaptic striatal D 2 DA receptor agonist apomorphine, did not induce stereotyped behaviour (SB) in rats. This indicates that flunarizine does not act as an agonist at the postsynaptic striatal D 2 DA receptors. 3. Flunarizine however, like the postsynaptic striatal D 2 DA receptor antagonist haloperiodal, inhibited the conditioned avoidance response, induced catalepsy and antagonized the SB induced by the DA agonists apomorphine and methamphetamine. 4. Our findings indicate that flunarizine acts as a postsynaptic striatal D 2 DA receptor antagonist. 相似文献