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231.
景蓓蓓杨晓红张胜海答敏张萍朱依娜 《现代生物医学进展》2011,11(7):1359-1362
目的:基于钙黄绿素的荧光分光光度法建立一种测定谷胱甘肽的新方法。方法:在pH=8.0介质中,铜(Ⅱ)与钙黄绿素配位引起荧光猝灭,由于谷胱甘肽与铜(Ⅱ)的亲和力很强,可从钙黄绿素-铜离子的络合物中夺取铜离子而使钙黄绿素游离出来使荧光强度得以恢复,荧光恢复的程度与加入谷胱甘肽的浓度在一定浓度范围内成线性。结果:据此建立了一种测定谷胱甘肽的新方法,该方法的线性范围为2.0×10-6~1.4×10-5mol.L-1,F=8.1964C+196.43,检测限为1.0×10-6mol/L。结论:用此法测定谷胱甘肽简便快速,灵敏度高。 相似文献
232.
目的:研究功能矫形前伸大鼠下颌后浅层嚼肌细胞凋亡的变化规律,探讨功能矫形的肌肉改建机理。方法:选用50只5周龄Sprague-Dawley(SD)雄性大白鼠,随机分为实验组和对照组各25只。实验组大鼠戴自制上颌功能矫治嚣,引导下颌前伸,并打开咬合。利用RT-PCR方法检测两组大鼠浅层嚼肌Bcl-2和Bax基因表达情况,利用TUNEL方法检测浅层嚼肌细胞凋亡情况。结果:①Bcl-2和Bax基因表达随大鼠戴用矫治器时间的延长而升高,至第3周开始下降但仍高于对照组,但Bax的表达高于Bcl-2。Bax/Bcl-2比值随大鼠戴用矫治器时间的延长而升高,至第4周开始下降。②TUNEL实验结果显示浅层嚼肌细胞在戴用矫治器1天后,开始出现凋亡,随着时间延长而增加,至第3周达到顶峰,第4周开始下降。结论:①Bax/Bcl-2比值升高促进浅层嚼肌细胞凋亡。②功能矫形可引起浅层嚼肌细胞凋亡,导致肌肉的结构和功能发生适应性改建。 相似文献
233.
Involvement of the multilineage CD38 molecule in a unique pathway of cell activation and proliferation 总被引:26,自引:0,他引:26
A Funaro G C Spagnoli C M Ausiello M Alessio S Roggero D Delia M Zaccolo F Malavasi 《Journal of immunology (Baltimore, Md. : 1950)》1990,145(8):2390-2396
We report clear evidence that the interaction of the CD38 molecule with the specific mAb A10 on normal human cells and lines modulates the expression of surface activation markers relevant to T, NK, and plasma cell biology and functions. Moreover A10 mAb binding is followed by proliferation effects on all the target cells analyzed, and the phenomenon is accessory cell and IL-2 dependent. The effects of A10 mAb synergizing both CD2 and CD3 activation pathways indicate that CD38 signal transduction mechanism(s) are apparently different from the aforementioned. Nevertheless the decreased A10-driven proliferation after CD3-Ti modulation suggests a possible functional interdependence between these activation pathways. Taken together, the results indicate that the CD38 molecule might play a physiologic role in T, NK, and plasma cell regulation. 相似文献
234.
Hexose-6-phosphate dehydrogenase (H6PDH-A2; beta-D-glucose:NAD(P)+
oxido-reductase; E.C. 1.1.1.47) of the teleost Fundulus heteroclitus (L.)
shows clinal allelic variation along the east coast of North America. Three
of the major allelic isozymes have been purified and compared for native
molecular weight, subunit molecular weight, isoelectric point, thermal
stability, and steady-state kinetic properties (pH 8.0 and 25 degrees C).
Significant differences were found among the allelic isozymes for
isoelectric point, thermal stability, and some kinetic parameters. The
predominant allelic isozyme in northern populations (H6PDH-AcAc) was found
to be more sensitive to heat denaturation than were the predominant
homozygous allelic isozymes isolated from southern populations (H6PDH-AaAa
and H6PDH-AbAb). The H6PDH-AcAc allelic isozyme had both a significantly
greater Km for glucose-6-phosphate than did either of the southern
phenotypes and a significantly greater Km for NADP+ and Ki of NAD+ than did
one of the southern phenotypes (H6PDH-AaAa). While the allelic isozymes are
functionally nonequivalent, it is not yet known whether these differences
are reflected at higher levels of biological organization.
相似文献
235.
236.
D. Ausiello J. Handler J. Orloff 《Biochimica et Biophysica Acta (BBA)/General Subjects》1976,451(2):372-381
Suspensions of renal cortical tubules were incubated with 33Pi and exposed to parathyroid hormone (40 μg/ml) or 1 mM dibutyryl cyclic AMP. In other experiments homogenates of renal cortex were assayed for protein kinase and phosphoprotein phosphatase activity using [γ-32P]ATP with or without 5 mM cyclic AMP. Proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and phosphorylation of proteins measured by liquid scintillation counting of gel slices. The pattern of protein phosphorylation was similar in control tissue from both tubule suspensions and homogenates. In intact tubules, parathyroid hormone stimulated the phosphorylation of four proteins with molecular weights of approx. 1500 000, 125 000, 100 000 and 50 000 by 28%, 24%, 13%, and 20%, respectively. Results with dibutyryl cyclic AMP were comparable but more variable. Stimulation of phosphorylation by cyclic AMP in homogenates was more generalized with the major effect on a 50 000 dalton protein (50% stimulation). No effect of cyclic AMP on dephosphorylation of proteins was observed. The results are interpreted as indicating that increased phosphorylation of cell proteins is part of the cyclic AMP-mediated response of the renal cortex to parathyroid hormone. 相似文献
237.
238.
Frasca L Nasso M Spensieri F Fedele G Palazzo R Malavasi F Ausiello CM 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(3):1471-1481
Dendritic cells (DCs) are central players in immunity and are used in immune-adoptive vaccine protocols in humans. IFN-gamma, mandatory in Th-1 polarization and endowed with regulatory properties, is currently used to condition monocyte-derived DCs (MDDC) in cancer therapy and in clinical trials to treat chronic infectious diseases. We therefore performed a wide analysis of IFN-gamma signaling consequences on MDDC multiple effector functions. IFN-gamma itself induced IL-27p28 expression and survival but did not promote relevant CCR7-driven migration or activated Th-1 cell recruitment capacity in MDDC. Administered in association with classical maturation stimuli such as CD40 or TLR-4 stimulation, IFN-gamma up-regulated IL-27 and IL-12 production, CCR7-driven migration, and activated Th-1 cell recruitment, whereas it decreased IL-10 production and STAT3 phosphorylation. CD38 signaling, which orchestrates migration, survival, and Th-1 polarizing ability of mature MDDC, was involved in IFN-gamma-mediated effects. Thus, IFN-gamma is a modulator of multiple DC effector functions that can be helpful in MDDC-based vaccination protocols. These data also help understand the dual role exerted by this cytokine as both an inducer and a regulator of inflammation and immune response. 相似文献
239.
TT Chowdhury S Arghandawi J Brand OO Akanji DL Bader DM Salter DA Lee 《Arthritis research & therapy》2008,10(2):R35
Background
Nitric oxide and prostaglandin E2 (PGE2play pivotal roles in both the pathogenesis of osteoarthritis and catabolic processes in articular cartilage. These mediators are influenced by both IL-1β and mechanical loading, and involve alterations in the inducible nitric oxide synthase (iNOS) and cyclo-oxygenase (COX)-2 enzymes. To identify the specific interactions that are activated by both types of stimuli, we examined the effects of dynamic compression on levels of expression of iNOS and COX-2 and involvement of the p38 mitogen-activated protein kinase (MAPK) pathway. 相似文献240.