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排序方式: 共有400条查询结果,搜索用时 15 毫秒
131.
An improved Ficoll density gradient centrifugation method has been described for the isolation of goat caput-epididymal immature spermatozoa of a high purity and intactness. The method consists of layering freshly extracted sperm suspension on the top of a Ficoll gradient comprising 2.5 ml each of 2%, 4%, 6%, and 8% Ficoll-400 in a modified Ringer's solution and centrifugation at 300 g for 3 min in a swing bucket table centrifuge. Spermatozoa, free from fat globules and blood cells, sedimented at the bottom of the 8% Ficoll layer. The plasma membrane of the isolated cells showed a high degree of intactness (approximately 96%) as assessed by lactic dehydrogenase marker enzyme and ethidium bromide-fluorescence methods. 相似文献
132.
The effects of lanthanum chloride administration in newborn chicks on glutamate uptake and release by brain synaptosomes 总被引:4,自引:0,他引:4
Aruna Basu Krishanu Chakrabarty Subrata Haldar Sankar Addya Gora Chand Chatterjee 《Toxicology letters》1984,20(3):303-308
Acute i.p. administration of lanthanum chloride to newborn chicks at a single dose of 250 mg/kg body weight causes inhibition of the high affinity uptake of [14C]glutamate by isolated brain synaptosomes. There is also a marked decrease in the release of preloaded [14C]glutamate from brain synaptosomes in the presence of externally available Ca2+ (1.2 mM) or a high K+ concentration (71 mM). The inhibition of glutamate release has been discussed in relation to depletion of Ca2+ binding to the synaptosomal membrane under lanthanum intoxication. 相似文献
133.
Bhattacharyya N Pal A Patra S Haldar AK Roy S Ray M 《International immunopharmacology》2008,8(11):1503-1512
Methylglyoxal is a normal metabolite and has the potential to affect a wide variety of cellular processes. In particular, it can act selectively against malignant cells. The study described herein was to investigate whether methylglyoxal can enhance the non-specific immunity of the host against tumor cells. Methylglyoxal increased the number of macrophages in the peritoneal cavity of both normal and tumor-bearing mice. It also elevated the phagocytic capacity of macrophages in both these groups of animals. This activation of macrophages was brought about by increased production of Reactive Oxygen Intermediates (ROIs) and Reactive Nitrogen Intermediates (RNIs). The possible mechanism for the production of ROIs and RNIs can be attributed to stimulation of the respiratory burst enzyme NADPH oxidase and iNOS, respectively. IFN-gamma, which is a regulatory molecule of iNOS pathway also showed an elevated level by methylglyoxal. TNF-alpha, which is an important cytokine for oxygen independent killing by macrophage also increased by methylglyoxal in both tumor-bearing and non tumor-bearing animals. Methylglyoxal also played a role in the proliferation and cytotoxicity of splenic lymphocytes. In short, it can be concluded that methylglyoxal profoundly stimulates the immune system against tumor cells. 相似文献
134.
In blood-stage infection by the human malaria parasite Plasmodium falciparum, export of proteins from the intracellular parasite to the erythrocyte is key to virulence. This export is mediated by a host-targeting (HT) signal present on a "secretome" of hundreds of parasite proteins engaged in remodeling the erythrocyte. However, the route of HT-mediated export is poorly understood. Here we show that minimal soluble and membrane protein reporters that contain the HT motif and mimic export of endogenous P falciparum proteins are detected in the lumen of "cleft" structures synthesized by the pathogen. Clefts are efficiently targeted by the HT signal. Furthermore, the HT signal does not directly translocate across the parasitophorous vacuolar membrane (PVM) surrounding the parasite to deliver protein to the erythrocyte cytoplasm, as suggested by current models of parasite protein trafficking to the erythrocyte. Rather, it is a lumenal signal that sorts protein into clefts, which then are exported beyond the PVM. These data suggest that Maurer's clefts, which are unique to the virulent P falciparum species, are pathogen-induced secretory organelles that concentrate HT-containing soluble and membrane parasite proteins in their lumen for delivery to the host erythrocyte. 相似文献
135.
Krishnayan Haldar Panagiotis Giamougiannis Robin Crawford 《International journal of gynaecology and obstetrics》2011,113(3):222-224
Objective
To evaluate institutional experiences regarding laparoscopic salpingo-oophorectomy in breast cancer patients and to compare the technique with gonadotropin-releasing hormone (GnRH) analogs among premenopausal women with hormone-sensitive breast cancer.Methods
Between 2004 and 2009, 103 women with breast cancer underwent laparoscopic salpingo-oophorectomy at Addenbrooke's Hospital, Cambridge, UK. All relevant medical records—including reasons for salpingo-oophorectomy, peri-operative events, and subsequent follow-up—were reviewed.Results
In the study period, 3 (2.9%) women experienced a recurrence of breast cancer but none had primary peritoneal/ovarian cancer within a median follow-up interval of 34 months (range, 0-70 months). No operative complications were noted among these women and all of them went home on the day of their operation.Conclusion
Laparoscopic salpingo-oophorectomy seems to be a safe, permanent, and cost-effective method of ovarian ablation compared with the use of GnRH analogs. Salpingo-oophorectomy also considerably reduces the risk of subsequent ovarian/fallopian tube malignancy in this high-risk population. 相似文献136.
Daily variation in the peripheral level of melatonin plays a major role in integrating reproduction and environmental information for seasonally breeding birds. However, the variation in immunity and reproduction has never been assessed in any avian species on a 24 h time scale. Therefore, to understand the relationship between immune function and reproductive phases in a seasonally breeding bird, Perdicula asiatica, the Indian jungle bush quail, we studied the daily variation of melatonin and testosterone levels along with expression of their receptors Mel(1a), Mel(1b), and androgen receptor in the spleen during the reproductively active phase. Immunocytochemistry for the melatonin receptors Mel(1a) and Mel(1b) presented a differential distribution pattern. Western blot of splenic protein suggested a daily rhythm of melatonin receptors, while acrophases for the two melatonin receptors Mel(1a) and Mel(1b) differed by 4 h, suggesting that the expression of the receptors may peak at different times, causing more of either Mel(1a) or Mel(1b) to be available at a particular time to mediate function. The circulatory melatonin level correlated with percentage stimulation ratio of splenocytes and plasma interleukin-2 level, but did not correlate with testosterone or androgen receptor, suggesting that melatonin could be a major hormone imparting a time-of-day effect on the modulation of immune function in a seasonally breeding bird during the reproductively active phase. 相似文献
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139.
Prevalence of human papillomavirus,Epstein‐Barr virus,and cytomegalovirus in fine needle aspirates from lung carcinoma: A case–control study with review of literature
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140.
Indrajit Karmakar Sagnik Haldar Mainak Chakraborty Keya Chaudhury Saikat Dewanjee 《Pharmaceutical biology》2016,54(3):503-508
Context: Many of the major chemotherapeutic agents are secondary metabolites found in nature. Zanthoxylum alatum Roxb. (Rutaceae) is traditionally used in the treatment of various diseases.Objective: The present study evaluates the apoptotic activity of methanol extract of Z. alatum (MEZA) on Ehrlich ascites tumor (EAT) in Swiss albino mice.Materials and methods: The presence of flavonoids in MEZA was standardized by HPLC. The in vitro cytotoxicity of MEZA was measured by the MTT assay. The in vivo antitumor activity of MEZA (100 and 200?mg/kg b.w., i.p. for 9 days) was also evaluated. On the 10th day, EAT tumor volume, cell viability, and hematological parameters were assayed. Apoptotic morphology was determined by acredine orange/ethedium bromide using fluorescence microscopy. Apoptosis percentage was measured by flow cytometric analysis using annexine-V-FITC. Also, DNA damage and bcl-2/bax were estimated by UV-method and western blot, respectively.Results and discussion: HPLC analysis revealed presence of three flavonoids, rutin, myricetin, and quercetin. MEZA showed satisfactory cytotoxicity in MTT assay (IC50?=?111.50?µg/ml). The extract significantly (p?<?0.01) changed the tumor volume, viable, non-viable cell count, and hematological parameters towards the normal. Apoptotic activity of MEZA was confirmed by acridine orange/ethidium bromide staining, annexin-V-FITC staining, DNA fragmentation, and Bcl-2/Bax ratio.Conclusion: The study showed that MEZA has antitumor activity which may be due to the presence of flavonoids in the extract. 相似文献