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排序方式: 共有256条查询结果,搜索用时 15 毫秒
1.
Seyed Sajad Mohseni Salehi Monfared Shirin Pournourmohammadi 《Biological trace element research》2010,133(2):236-241
Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after
isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation
procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on
islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic
islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01
and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as
islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly
increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group
containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before
transplantation. 相似文献
2.
Oxygen-glucose deprivation (OGD) leads to depression of evoked synaptic transmission, for which the mechanisms remain unclear. We hypothesized that increased presynaptic [Ca2+]i during transient OGD contributes to the depression of evoked field excitatory postsynaptic potentials (fEPSPs). Additionally, we hypothesized that increased buffering of intracellular calcium would shorten electrophysiological recovery after transient ischemia. Mouse hippocampal slices were exposed to 2 to 8 min of OGD. fEPSPs evoked by Schaffer collateral stimulation were recorded in the stratum radiatum, and whole cell current or voltage clamp recordings were performed in CA1 neurons. Transient ischemia led to increased presynaptic [Ca2+]i, (shown by calcium imaging), increased spontaneous miniature EPSP/Cs, and depressed evoked fEPSPs, partially mediated by adenosine. Buffering of intracellular Ca2+ during OGD by membrane-permeant chelators (BAPTA-AM or EGTA-AM) partially prevented fEPSP depression and promoted faster electrophysiological recovery when the OGD challenge was stopped. The blocker of BK channels, charybdotoxin (ChTX), also prevented fEPSP depression, but did not accelerate post-ischemic recovery. These results suggest that OGD leads to elevated presynaptic [Ca2+]i, which reduces evoked transmitter release; this effect can be reversed by increased intracellular Ca2+ buffering which also speeds recovery. 相似文献
3.
Javad Tavakkoly Bazzaz Mahnaz Shojapoor Habibollah Nazem Parvin Amiri Hossein Fakhrzadeh Ramin Heshmat Maryam Parvizi Shirin Hasani Ranjbar Mahsa M. Amoli 《Molecular biology reports》2010,37(1):105-109
Methylenetetrahydrofolate reductase (MTHFR) polymorphism may play an important role in the pathophysiology of obesity and
diabetes accompanied by obesity due to its influence on plasma homocysteine levels. There are significant and sometimes very
strong relationship between levels of homocysteine and several multi-system diseases including CHD and CVA. To examine the
association between MTHFR gene C677T polymorphism in diabetes and obesity with serum homocysteine levels. A total of 682 subjects
were recruited in four groups (Normal, obese, diabetic and obese and diabetics). MTHFR gene C677T polymorphism was detected
using PCR-RFLP technique. Serum homocysteine levels were measured using HPLC. There was a significant increase in the mean
serum homocysteine levels in subjects carrying TT genotype (34.6 ± 26.5) compared to subjects carrying CC (15.1 ± 8) or CT
genotype (16.4 ± 7.8) (P < 0.000). We found no significant differences for MTHFR allele and genotype frequencies between different groups. Our data
have confirmed the association between serum homocysteine levels and MTHFR C677T genotype reported in other populations. 相似文献
4.
Anser C. Azim Joan H. M. Knoll Shirin M. Marfatia David J. Peel Peter J. Bryant Athar H. Chishti 《Genomics》1995,30(3)
The Drosophila discs large tumor suppressor protein, Dlg, is the prototype of a newly discovered family of proteins termed MAGUKs (membrane-associated guanylate kinase homologues). MAGUKs are localized at the membrane-cytoskeleton interface, usually at cell-cell junctions, where they appear to have both structural and signaling roles. They contain several distinct domains, including a modified guanylate kinase domain, an SH3 motif, and one or three copies of the DHR (GLGF/PDZ) domain. Recessive lethal mutations in the discs large tumor suppressor gene interfere with the formation of septate junctions (thought to be the arthropod equivalent of tight junctions) between epithelial cells, and they cause neoplastic overgrowth of imaginal discs, suggesting a role for cell junctions in proliferation control. A homologue of the Dlg protein, named Hdlg, has been isolated from human B lymphocytes. It shows 65-79% identity to Dlg in the different domains, and it binds to the cytoskeletal protein 4.1. Here, we report that the gene for lymphocyte Hdlg, named DLG1, is located at chromosome band 3q29. This finding identifies a novel site for a candidate tumor suppressor on chromosome 3. 相似文献
5.
6.
The minority culture of mobility of France's upwardly mobile descendants of North African immigrants
Shirin Shahrokni 《Ethnic and racial studies》2013,36(7):1050-1066
This article examines the challenges associated with the experience of upward educational mobility among descendants of North African immigrants in France. Drawing on in-depth, open-ended interviews with students and graduates of the prestigious grandes écoles, it sheds light on three specific ways in which class-based and ethno-racial inequalities intersect to shape the mobility costs that our respondents outline: (1) feelings of isolation resulting from being one of the only bursar recipients and ethno-racial minorities of their schools; (2) perceived conflation of their minority background with counter-elite dispositions; and (3) difficulties of adjusting to a student life reflecting the cultural styles of the predominantly white, upper-middle-class group. The article suggests that our respondents deploy a minority culture of mobility rooted in class and ethno-racial processes to overcome these challenges. It finally discusses implications for future research, stressing the need to examine the intersecting effect of multiple social categories in informing complex mobility experiences. 相似文献
7.
8.
A thermo-alkaliphilic lipase from Bacillus subtilis DR8806 was functionally expressed as an N-terminal 6xHis-tagged recombinant enzyme in Escherichia coli BL21 using pET-28a(+) expression vector. Sequence analysis revealed an open reading frame of 639 bp encoding a 212-amino acid protein containing the well-conserved Ala-His-Ser-Met-Gly motif. One-step purification of the His-tagged recombinant lipase was achieved using Ni-NTA affinity chromatography with a specific activity of 1364 U/mg. The purified enzyme with an apparent molecular mass of 26.8 kDa demonstrated the maximum activity at 70 °C and pH 8.0 for hydrolysis of p-nitrophenylbutyrate as substrate. The enzyme activity was strongly inhibited by divalent ions of heavy metals such as Hg2+ and Cu2+, while retained over 90% of the original activity in the presence of several reagents including DTNB (5,5′-dithiobis-(2-nitrobenzoic acid)), SDS (sodium dodecyl sulfate), urea, DMF (dimethylformamide), DTT (dithiothreitol), glycerol and Triton X-100. While being considerably stable in organic solvents, imidazolium-based ionic liquids (ILs) had stimulatory effects on the activity of purified lipase. Remarkable stabilization of enzyme at alkaline pH and in ionic liquids as well as its thermostability/thermoactivity are among the most fundamental characteristics which offer great potential for various biotechnological applications including detergent formulation, bioremediation processes and biotransformation in non-aqueous media. 相似文献
9.
Farhani Ibrahim Nezafat Navid Mahmoodi Shirin 《International journal of peptide research and therapeutics》2019,25(2):541-553
International Journal of Peptide Research and Therapeutics - Shigella spp. causes severe diarrhea and dysenteric disease, which known as shigellosis. Until now, no licensed vaccine is available for... 相似文献
10.
Bevacizumab Antibody Affinity Maturation to Improve Ovarian Cancer Immunotherapy: In Silico Approach
Eyvazi Shirin Payandeh Zahra Khalili Saeed Sefid Fatemeh Ouladsahebmadarek Elaheh 《International journal of peptide research and therapeutics》2019,25(4):1417-1430
International Journal of Peptide Research and Therapeutics - Ovarian cancer is one of the most lethal gynecologic cancers. The high mortality rate is due to lack of early symptoms and developing... 相似文献