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排序方式: 共有1932条查询结果,搜索用时 15 毫秒
1.
M A Akbarsha B Manivannan K S Hamid B Vijayan 《Indian journal of experimental biology》1990,28(5):421-426
Dry leaf powder of A. paniculata, when fed orally to male albino rats, at a dose level of 20 mg powder per day for 60 days, resulted in cessation of spermatogenesis, degenerative changes in the seminiferous tubules, regression of Leydig cells and regressive and/or degenerative changes in the epididymis, seminal vesicle, ventral prostate and coagulating gland. There was reduction in the weight and fluid content of the accessory glands. The treatment also resulted in accumulation of glycogen and cholesterol in the testis, and increased activities of lactate dehydrogenase in testis and alkaline phosphatase in testis and ventral prostate. The results suggest antispermatogenic and/or antiandrogenic effect of the plant. 相似文献
2.
Hamid Hadi-Alijanvand Elizabeth A. Proctor Bahram Goliaei Nikolay V. Dokholyan Ali A. Moosavi-Movahedi 《PloS one》2012,7(10)
Prolyl hydroxylase domain 2 containing protein (PHD2) is a key protein in regulation of angiogenesis and metastasis. In normoxic condition, PHD2 triggers the degradation of hypoxia-inducible factor 1 (HIF-1α) that induces the expression of hypoxia response genes. Therefore the correct function of PHD2 would inhibit angiogenesis and consequent metastasis of tumor cells in normoxic condition. PHD2 mutations were reported in some common cancers. However, high levels of HIF-1α protein were observed even in normoxic metastatic tumors with normal expression of wild type PHD2. PHD2 malfunctions due to protein misfolding may be the underlying reason of metastasis and invasion in such cases. In this study, we scrutinize the unfolding pathways of the PHD2 catalytic domain’s possible species and demonstrate the properties of their unfolding states by computational approaches. Our study introduces the possibility of aggregation disaster for the prominent species of PHD2 during its partial unfolding. This may justify PHD2 inability to regulate HIF-1α level in some normoxic tumor types. 相似文献
3.
Hamid Reza Noori 《Journal of biological physics》2012,38(4):597-606
The phenomena related to brain function occur as the interplay of various modules at different spatial and temporal scales. Particularly, the integration of the dynamical behavior of cells within the complex brain topology reveals a heterogeneous multi-scale problem, which has, to date, mainly been addressed by methods of statistical physics such as mean-field approximations. In contrast, the present study introduces an abstract mathematical model of a deterministic nature that provides a robust integral transformation of the microscopic activities into macroscopic spatiotemporal patterns. The existence of the transformation operator is guaranteed by the convergence of a repetitive patching of the network domain with its fundamental domains that express the local topologies of the tissue. Depending on the choice of the local connectivity function, this framework represents a computationally efficient generalization of the classical Kirchhoff’s, Hebbian, and Hopfield’s approaches. The capabilities of this multi-scale method have been evaluated within the structure of the dorsal striatum of rats, a brain region with major involvement in motor and cognitive information processing. Numerical simulations suggest the formation of characteristic spatiotemporal patterns due to the activation of cholinergic interneurons. 相似文献
4.
Males of the predatory mirid bug Macrolophus caliginosus exploit plant volatiles induced by conspecifics as a sexual synomone 总被引:1,自引:0,他引:1
Hamid R. S. Moayeri Ahmad Ashouri Henrik F. Brødsgaard & Annie Enkegaard 《Entomologia Experimentalis et Applicata》2007,123(1):49-55
The olfactory responses of male and female Macrolophus caliginosus Wagner (Heteroptera: Miridae) adults towards volatiles from green bean plants previously exposed to feeding by conspecifics and to direct odours from conspecifics were tested in a Y-tube olfactometer. Female M. caliginosus did not respond to volatiles from plants exposed to mirid feeding or to odours emitted directly by adult mirids. In contrast, male mirid bugs were attracted both to volatiles from plants previously exposed to feeding by conspecific females and to odours emitted by conspecifics only with a marginally significant preference for the former. The gas chromatography-mass spectrometry analysis showed that mirid feeding induced the release of 11 additional compounds as compared to the volatiles emitted from clean plants. Three of these substances (5-ethyl-2(5H)-furanone, Z-3-hexenyl tiglate, and E,E-α-farnesene) were released only after feeding by females. Furthermore, 21 compounds were identified in volatiles emitted directly by mirids, 12 of which were unique to the mirids (i.e., not present in clean plants or plants previously exposed to mirid feeding). The results suggest that female-specific herbivore-induced plant volatiles play a role as mate-finding cues by the male mirids. The ecological implications of the findings are discussed, and the term ‘sexual synomone’ is introduced. 相似文献
5.
Javad Sajedianfard Zahra Behroozi Saeed Nazifi Hamid Rajaian 《International journal of peptide research and therapeutics》2013,19(2):93-98
The effect of oral administration of different doses of hydroalcoholic extract of silymarin on body weight, glucose concentration and indicators of oxidative stress superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and malondialdehyde (MDA) was investigated in the present study. Fifty adult male Wistar rats were used. The animals were divided into five groups and oral route of administration was used in control group (0.9 %, NaCl), control group patients (0.9 %, NaCl), diabetic group (100 mg/kg, silymarin), diabetic group (125 mg/kg, silymarin), diabetic group (250 mg/kg, silymarin) for 14 days with gavage. Diabetes was induced by a single injection of streptozotocin (45 mg/kg, i.p.). Before and 3 days after injection, and at 7 and 14 days of treatment, the fasting glucose level and weight were measured. At the end of 14 days, animals were anesthetized with ether and blood samples were taken by heart puncture and were analyzed for oxidative stress indicators. The results showed that hydroalcoholic extract of silymarin can increase the average body weight and decrease glucose and, at the end of 14 days, decrease MDA level and increase the level of antioxidant enzymes (SOD, GPX, CAT) in red blood cells in a dose-dependent manner (P < 0.05). In conclusion, the hydroalcoholic extract of silymarin has an overall beneficial effect on body weight, glucose level and oxidative stress. Therefore, silymarin may reduce oxidative stress via increasing antioxidant enzyme activity. 相似文献
6.
Shima Rajaei Saeed Karima Hessam Sepasi Tehrani Somayeh Shateri Somayeh Mahmoodi Baram Meisam Mahdavi Farzad Mokhtari Alimohammad Alimohammadi Abbas Tafakhori Abolfazl Amiri Vajiheh Aghamollaii Hamid Fatemi Masoumeh Rajabibazl Farzad Kobarfard Ali Gorji 《Journal of neurochemistry》2020,155(2):207-224
7.
Kim H Naura AS Errami Y Ju J Boulares AH 《Molecular medicine (Cambridge, Mass.)》2011,17(9-10):893-900
Cordycepin has been shown to interfere with a myriad of molecular processes from RNA elongation to kinase activity, and prevents numerous inflammatory processes in animal models. Here we show in a mouse model of LPS-induced acute lung injury that cordycepin prevents airway neutrophilia via a robust blockade of expression of several inflammatory genes, including the adhesion molecule ICAM-1 and VCAM-1, the cytokine/chemokine MCP-1, MIP-1α, MIP-2 and KC, and the chemokine receptor CXCR2. Such a blockade appears to be related to a severe reduction in TNF-α expression. Interestingly, in an in vitro system of A549 epithelial cell inflammation, cordycepin effectively blocked LPS-induced, but not TNF-α-induced, VCAM-1 expression. Such effects correlated with a marked reduction in p65-NF-κB activation as assessed by its phosphorylation at serine-536 but without an apparent effect on its nuclear translocation. The effects of cordycepin on the expression of VCAM-1 and ICAM-1, and of NF-κB activation and nuclear translocation upon TNF-α stimulation resembled the effects achieved upon poly(ADP-ribose) polymerase (PARP) inhibition, suggesting that cordycepin may function as a PARP inhibitor. Indeed, cordycepin blocked H(2)O(2)-induced PARP activation in A549 cells. In a cell-free system, cordycepin inhibited PARP-1 activity at nanomolar concentrations. Similar to PARP inhibitors, cordycepin significantly induced killing of breast cancer susceptibility gene (BRCA1)-deficient MCF-7 cells, supporting its therapeutic use for the treatment of BRCA-deficient breast cancers. With added antiinflammatory characteristics, therapies that include cordycepin may prevent potential inflammation triggered by traditional chemotherapeutic drugs. Cordycepin, to the best of our knowledge, represents the first natural product possessing PARP inhibitory traits. 相似文献
8.
9.
Competing for blood: the ecology of parasite resource competition in human malaria–helminth co‐infections 下载免费PDF全文
Sarah A. Budischak Aprilianto E. Wiria Firdaus Hamid Linda J. Wammes Maria M. M. Kaisar Lisette van Lieshout Erliyani Sartono Taniawati Supali Maria Yazdanbakhsh Andrea L. Graham 《Ecology letters》2018,21(4):536-545
Ecological theory suggests that co‐infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) between malaria and bloodsucking helminths can regulate malaria population dynamics, but the importance of RBC competition in human hosts was unknown. We analysed infection density (i.e. the concentration of parasites in infected hosts), from a 2‐year deworming study of over 4000 human subjects. After accounting for resource‐use differences among parasites, we find evidence of resource competition, priority effects and a competitive hierarchy within co‐infected individuals. For example reducing competition via deworming increased Plasmodium vivax densities 2.8‐fold, and this effect is limited to bloodsucking hookworms. Our ecological, resource‐based perspective sheds new light into decades of conflicting outcomes of malaria–helminth co‐infection studies with significant health and transmission consequences. Beyond blood, investigating within‐human resource competition may bring new insights for improving human health. 相似文献
10.
Shahabi V Whitney G Hamid O Schmidt H Chasalow SD Alaparthy S Jackson JR 《Cancer immunology, immunotherapy : CII》2012,61(5):733-737
Ipilimumab, a fully human monoclonal antibody against cytotoxic T lymphocyte antigen-4, has demonstrated significant improvement
in overall survival in previously treated advanced melanoma patients. The BRAF inhibitor, vemurafenib, has shown up to 78%
objective response rates in melanoma patients harboring the BRAF-V600E mutation but not in patients lacking the mutation.
As an immune potentiator, the mechanism of action of ipilimumab may not be dependent of the activity of the BRAF pathway.
To test this, we investigated whether the clinical activity of ipilimumab would be affected by the BRAF-V600E mutation status
of the tumors. Thus, this retrospective analysis was carried using a set of tumor biopsies from a completed phase II clinical
trial. CA184004 was a randomized, double-blind, multicenter trial of 82 previously treated or untreated patients with unresectable
stage III/IV melanoma. Patients received ipilimumab 3 or 10 mg/kg every 3 weeks for four doses followed by maintenance dosing
in eligible patients. The BRAF-V600E mutation status for 80 patients was determined in tumor biopsies by PCR-based assays.
Data on disease control were available for 69 patients with evaluated BRAF-V600E mutation status. Rates of objective responses
and stable disease in patients with BRAF-V600E mutation positive tumors (30%) were comparable to those in patients with the
wild-type gene (~33%). Eleven patients displayed Durable Disease Control (DDC) of which 55% had BRAF-V600E mutation positive
tumors and 45% did not. In the 48 patients showing no DDC, the mutation frequency was 50%. In this study, no association between
BRAF-V600E mutation status of melanoma tumors and DDC after treatment with ipilimumab was detected. 相似文献