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排序方式: 共有263条查询结果,搜索用时 187 毫秒
81.
Harish Rajak Bhupendra Singh Thakur Avineesh Singh Kamlesh Raghuvanshi Anil Kumar Sah Ravichandran Veerasamy Prabodh Chander Sharma Rajesh Singh Pawar Murli Dhar Kharya 《Bioorganic & medicinal chemistry letters》2013,23(3):864-868
Two novel series of N4-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N1-(2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enylidene)semicarbazide and N4-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N1-(3,7-dimethylocta-3,6-dienylidene)-semicarbazide were synthesized to meet structural prerequisite indispensable for anticonvulsant activity. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES), subcutaneous pentylenetrtrazole (scPTZ) and subcutaneous strychnine (scSTY) models. The rotorod test was conducted to evaluate neurotoxicity. Some of the selected active compounds were subjected to GABA assay to confirm their mode of action. The outcome of the present investigations proved that the four binding sites pharmacophore model is vital for anticonvulsant activity. The efforts were also made to establish structure–activity relationships among test compounds. 相似文献
82.
Numerous wild bovids are facing threat of extinction owing to the loss of habitat and various other reasons. Spermatogonial stem cells (SSCs) represent the only germline stem cells in adult body that are capable of self-renewal and that can undergo differentiation to produce haploid germ cells. SSCs can, therefore, serve as a useful resource for preservation of germplasm of threatened and endangered mammals. The Indian black buck (Antilope cervicapra L.) is a small Indian antelope that is listed as endangered by the Indian Wildlife Protection Act, 1972. Immunohistochemical analysis of testes tissues of black buck revealed the presence of spermatogonia that were specifically stained by lectin-Dolichos biflorus agglutinin (DBA). The expression of pluripotent cell-specific markers, NANOG and stage-specific embryonic antigen-1 (SSEA-1), was detected in spermatogonia. Interestingly, the expression of POU5F1 (OCT3/4) was absent from spermatogonia, however, it was detected in differentiating cells such as spermatocytes and round spermatids but not in elongated spermatids. The expression of NANOG protein was also present in spermatocytes but absent in round and elongated spermatids. Using the testis transplantation assay, stem cell potential of black buck spermatogonia was confirmed as indicated by the presence of colonized DBA-stained cells in the basal membrane of seminiferous tubules of xenotransplanted mice testis. The findings from this study suggest the presence of SSCs in the testis of an endangered bovid for the first time and open new possibility to explore the use of SSCs in conservation. 相似文献
83.
Integrins play a major role in cell adhesion and migration. Previous work reported that a cleaved form of integrin alpha6 (alpha6p) was detected in invasive human prostate cancer tissue, absent in normal prostate tissue and was produced by urokinase-type Plasminogen Activator (uPA) in a plasmin-independent manner. Using site-directed mutagenesis we identified amino acid residues R594 and R595, located in the "stalk" region of integrin alpha6, as essential for cleavage. The cleavage site is located on the extracellular region of the protein between the beta-barrel domain and the thigh domain. Prostate cancer cells (PC3N) were stably transfected to overexpress the cleavable, wild-type (PC3N-alpha6-WT) or the non-cleavable form of integrin alpha6 (PC3N-alpha6-RR). The number of cells invading laminin 111- and laminin 332-coated filters by PC3N-alpha6-WT cells increased by threefold as compared to PC3N-alpha6-RR cells. Plasminogen activator inhibitor-1 (PAI-1) reduced the invasion of PC3N-alpha6-WT cells by approximately 42% through laminin 332-coated filters and plasmin inhibitor aprotinin had no significant effect. Linear cell migration increased production of integrin alpha6p in the PC3N-alpha6-WT cells and not in the PC3N-alpha6-RR cells and 32% of the PC3N-alpha6-WT cells migrated on laminin 111 in the linear migration assay as compared to the 5% PC3N-alpha6-RR cells. These data taken together suggest that the uPA-mediated cell surface cleavage of the alpha6 integrin extracellular domain is involved in tumor cell invasion and migration on laminin. 相似文献
84.
Nina Schweizer Nisha Pawar Matthias Weiss Helder Maiato 《The Journal of cell biology》2015,210(5):695-704
The mitotic spindle is a microtubular assembly required for chromosome segregation during mitosis. Additionally, a spindle matrix has long been proposed to assist this process, but its nature has remained elusive. By combining live-cell imaging with laser microsurgery, fluorescence recovery after photobleaching, and fluorescence correlation spectroscopy in Drosophila melanogaster S2 cells, we uncovered a microtubule-independent mechanism that underlies the accumulation of molecules in the spindle region. This mechanism relies on a membranous system surrounding the mitotic spindle that defines an organelle-exclusion zone that is conserved in human cells. Supported by mathematical modeling, we demonstrate that organelle exclusion by a membrane system causes spatio-temporal differences in molecular crowding states that are sufficient to drive accumulation of mitotic regulators, such as Mad2 and Megator/Tpr, as well as soluble tubulin, in the spindle region. This membranous “spindle envelope” confined spindle assembly, and its mechanical disruption compromised faithful chromosome segregation. Thus, cytoplasmic compartmentalization persists during early mitosis to promote spindle assembly and function. 相似文献
85.
86.
The aim of the present investigation was to develop and optimize gastroretentive floating system of amoxicillin for the efficient
treatment of peptic ulcer induced by Helicobacter pylori infection. Floating microballoons were developed using central composite design (CCD), and optimization was done by employing
response surface methodology. The selected independent variables were cellulose acetate phthalate, drug–Eudragit S100 ratio,
and the ratio of dichloromethane/ethanol/isopropyl alcohol. The selected dependent variables were yield, mean particle size,
buoyancy, encapsulation efficiency, and drug release within 8 h. A quadratic polynomial model was generated which had linear,
interaction, and quadratic terms to predict and evaluate the independent variables with respect to the dependent variables.
Results showed that selected independent variables significantly affect the yield (30.53–82.71%), particle size (31.62–47.03 μm),
buoyancy (42.68–95.75%), encapsulation efficiency (56.96–93.13%), and cumulative drug release from the microballoons (34.01–74.65%).
The interaction and quadratic terms were also found to affect the process variables. An excellent agreement was found between
the actual value and predicted value. In conclusion, it can be said that CCD is a valuable second-degree design to develop
and optimize GFS of amoxicillin which in turn provides a basis to localize the drug release in the gastric region for effective
treatment of H. pylori-mediated infection. 相似文献
87.
Surmounting the constraints of limited solubilization efficiency and prime requisite of antioxidant for conventional lipid
formulations, the research work explores an edge over formulation utilizing potential applicability of rice germ oil (RGO)
as a multifunctional excipient. Self-microemulsifying drug delivery system (SMEDDS) of tacrolimus (TAC) was formulated with
RGO, an indigenous source of gamma-oryzanol. Being the same biological source, RGO and rice bran oil (RBO) were compared and
it was found that RGO have more solubilization potential for TAC (2.2-fold) as well as higher antioxidant activity (8.06-fold)
than the RBO. TAC-SMEDDS was prepared using RGO/Capmul PG8 (2:3) as an oil phase, Cremophore EL as a surfactant, and Transcutol
P as a cosurfactant. The approximate particle size of TAC-SMEDDS was found to be 38 nm by dynamic light scattering and 12 nm
by small angle neutron scattering. The in vitro dissolution studies showed complete and rapid drug release in 30 min compared to a plain drug (<5%) and marketed capsule
(<50%). AUC and C
max were found to be 45.05 ± 15.64 ng h/ml and 3.91 ± 1.2 ng/ml for TAC-SMEDDS, 12.59 ± 5.54 ng h/ml and 0.48 ± 0.12 ng/ml for
plain TAC, and 30.23 ± 10.34 ng h/ml and 2.31 ± 0.68 ng/ml for marketed formulation, respectively. The improved pharmacokinetic
profile of TAC-SMEDDS is correlating to the dissolution results. Thus, gamma-oryzanol-enriched RGO acts as a potential multifunctional
excipient for lipid formulations. 相似文献
88.
Mourya DT Yadav PD Shete AM Gurav YK Raut CG Jadi RS Pawar SD Nichol ST Mishra AC 《PLoS neglected tropical diseases》2012,6(5):e1653
Background
In January 2011, human cases with hemorrhagic manifestations in the hospital staff were reported from a tertiary care hospital in Ahmadabad, India. This paper reports a detailed epidemiological investigation of nosocomial outbreak from the affected area of Ahmadabad, Gujarat, India.Principal Findings
Samples from 3 suspected cases, 83 contacts, Hyalomma ticks and livestock were screened for Crimean-Congo hemorrhagic fever (CCHF) virus by qRT-PCR of which samples of two medical professionals (case C and E) and the husband of the index case (case D) were positive for CCHFV. The sensitivity and specificity of indigenous developed IgM ELISA to screen CCHFV specific antibodies in human serum was 75.0% and 97.5% respectively as compared to commercial kit. About 17.0% domestic animals from Kolat, Ahmadabad were positive for IgG antibodies while only two cattle and a goat showed positivity by qRT-PCR. Surprisingly, 43.0% domestic animals (Buffalo, cattle, sheep and goat) showed IgG antibodies in the adjoining village Jivanpara but only one of the buffalo was positive for CCHFV. The Hyalomma anatolicum anatolicum ticks were positive in PCR and virus isolation. CCHFV was isolated from the blood sample of case C, E in Vero E-6 cells and Swiss albino mice. In partial nucleocapsid gene phylogeny from CCHFV positive human samples of the years 2010 and 2011, livestock and ticks showed this virus was similar to Tajikistan (strain TAJ/), which belongs in the Asian/middle east genetic lineage IV. H08966Conclusions
The likely source of CCHFV was identified as virus infected Hyalomma ticks and livestock at the rural village residence of the primary case (case A). In addition, retrospective sample analysis revealed the existence of CCHFV in Gujarat and Rajasthan states before this outbreak. An indigenous developed IgM ELISA kit will be of great use for screening this virus in India. 相似文献89.
Yadav MR Pawar VP Marvaniya SM Halen PK Giridhar R Mishra AK 《Bioorganic & medicinal chemistry》2008,16(21):9443-9449
Quaternized tropinol ester derivatives of some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) or their active metabolites, were prepared and studied for their anti-inflammatory activity in a chronic inflammation model and for inflamed tissue tropism. The quaternized esters were radiolabeled with 99mTechnetium (99mTc) and their selective localization in the inflamed tissue was traced using scintigraphy. In the chronic arthritis rodent model, most of the quaternized esters exhibited anti-inflammatory effect comparable to their respective parent drugs. In the gamma-imaging studies only the quaternary derivatives exhibited selective accumulation into the inflamed tissue unlike the parent NSAIDs or the unquaternized tropinol esters. This work is a step ahead in the direction of use of quaternary ammonium ester derivatives for site specific chemical delivery of commonly used NSAIDs to the inflamed tissues to minimize their GIT side effect or other systemic toxicities. 相似文献
90.
Deepali Jain Vijay K Jain Rakesh K Vasishta Prabhat Ranjan Yashwant Kumar 《Diagnostic pathology》2008,3(1):1-11