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991.
本实验研究切除卵巢造成肾虚骨质疏松症大鼠模型。通过观测红细胞膜蛋白激酶C(PKC)和Ca2+-Mg2_-ATP酶的活性,探讨肾虎骨质疏松症病理机制中肌醇脂质系统的变化,并结合全身和脊柱骨密度(BMD)指标观察了补肾中药(密骨灵)的疗效,与正常对照组、模型空白组和阳性药(骨疏康颗粒剂)对照组进行对照,探讨补肾法的防治机理。结果表明;模型空白组大鼠红细胞膜PKC和Ca2+-Mg2+-ATP酶、Mg2+-ATP酶的活性明显低于正常组(p均<0.05);密骨灵组与骨疏康组大鼠全身、脊柱BMD和红细胞膜PKC、Ca2+-Mg2+-ATP酶的活性均明显高于模型空白组(p均<0.05),并且与正常组大鼠无明显差别(p均>0.05);密骨灵组大鼠红细胞膜Mg2+-ATP酶活性高于模型空白组和骨疏康组(p<0.05),并且与正常组无显著性差异(p>0.05);密骨灵组大鼠红细胞膜PKC活性高于骨疏康组(P<0.05)。结论:肾虎骨质疏松症具有红细胞膜PKC和Ca2+-Mg2+-ATP酶、Mg2+-ATP酶活性的改变;密骨灵可以恢复肾虎骨质疏松症大鼠全身骨量,达到防治目的;补肾中药可以恢复红细胞膜PKC活性和钙镁泵的活性,是补  相似文献   
992.
The electrodeposition of Ag on Pt(100)-(1 × 1) in perchlorate electrolyte was studied by means of time-resolved in situ scanning tunnelling microscopy (STM) and cyclic voltammetry. One monolayer of Ag is deposited underpotentially (upd) ca. 500 mV positive of the Ag+/Ag equilibrium potential. Several millivolts positive of the equilibrium potential, a second well defined upd layer forms. Its growth was observed to proceed via island formation and coalescence. This process occurs in two separate stages that manifest themselves in voltammetric peaks as well as in the STM images.  相似文献   
993.
Granulocyte colony-stimulating factor (G-CSF) is being considered as adjuvant treatment for infections in non-neutropenic patients. Normal healthy donors were given rHuG-CSF (Lenograstim) at 2.5, 5.0 and 7.5 μg/kg subcutaneously daily for 5 d. Polymorphonuclear leucocyte (PMN) function tests were carried out on peripheral blood PMN before the first injection and at 24 h and 96 h. Circulating PMN levels were also measured at these time intervals and found to be significantly increased with all doses by 24 and 96 h. Investigation of cell surface antigen expression revealed no changes in β2 integrin (CD11b/CD18) expression. L-selectin (CD62L) expression was reduced with all doses by 96 h, this being significant with the 7.5 μg/kg dose. FcγRI (CD64) levels were significantly up-regulated with the 7.5 μg/kg dose by 96 h whereas FcγRIII (CD16) expression was found to be reduced during G-CSF treatment. Superoxide anion production was significantly increased in response to N -formylmethionylleucylphenylalanine (FMLP) and opsonized Staphylococcus epidermidis stimulation at 24 h and 96 h with the 5.0 and 7.5 μg/kg doses. The initial rate of phagocytosis (0–2 min) appeared to have increased with the 7.5 and 5.0 μg/kg doses at 96 and 24 h compared with PMN responses pretreatment, although these increases were not statistically significant. These results show that G-CSF enhances the functional responses of PMN stimulated by physiological agonists and may help in the treatment of infections.  相似文献   
994.
Experimental composites using either bisGMA/TEGDMA or UEDMA/ TEGDMA matrices, quartz or barium glass fillers, and 2 different filler silanization methods were evaluated regarding monomer leachability in distilled water. The leached amount was detected and quantified using gas chromatography. The results showed that twice as much TEGDMA is leached from a bisGMA/TEGDMA based composite than from an UEDMA/ TEGDMA based composite, when both contain 50 wt% TEGDMA. The hypothesis suggested that the higher degree of cure of UEDMA/TEGDMA based composites would be reflected in a lower monomer leaching value, and this hypothesis was supported by the findings. Whether such a correlation exists within groups of UEDMA/TEGDMA based matrices having different degrees of cure was not determined and needs to be investigated in future studies. Variables such as filler composition and silane treatment did not affect the leaching values of TEGDMA in water. That finding suggests that future studies should target differences in matrices, and that the need for considering effects of filler composition and silane treatment methods should not receive the same priority.  相似文献   
995.
采集23名产妇的脐带血和8名正常成人的外周血制备LAK细胞,随机分为4组,在培养第3,5,7,14天,分别利用MTT法和^125I-UdR释放法对4组LAK细胞的增殖力和杀伤活性进行了测定,同时用细胞毒方法测定培养7天的LAK细胞的免疫表型。结果发现,在不同培养时间,脐血来源的LAK细胞增殖力显著高于成人血LAK细胞(P〈0.05或P〈0.01),成人血清组,脐血血清组,红细胞组LAK细胞增殖力有  相似文献   
996.
The typical fourth criterion for transient entrainment is defined when both a sudden shortening in conduction interval to and a distinct change in electrogram morphology at a bipolar recording site are demonstrated while performing overdrive pacing of a reentrant tachycardia from a single pacing site at two different constant rates. The purpose of this article was to test the hypothesis that if an intracardiac recording site showing both orthodromic and antidromic capture with entrainment pacing is located suitably distant from the circuit, sudden shortening in conduction interval to that site may occur without any significant change in the bipolar electrogram morphology (i.e., atypical form of the fourth criterion). Atrial overdrive pacing of orthodromic tachycardia was performed in 20 patients with either left anterior (12 patients) or left posterior (8 patients) accessory pathways. We investigated the effects of overdrive pacing from the proximal or distal coronary sinus, specifically effects on the electrogram interval and the electrogram morphology at the right atrial appendage. Overdrive pacing of orthodromic tachycardia from the proximal coronary sinus was performed in 10 of the 12 patients with left anterior accessory pathways; those 10 patients demonstrated the first entrainment criterion at the right atrial appendage site. Overdrive pacing of orthodromic tachycardia at still shorter cycle lengths demonstrated a sudden shortening in conduction interval to the right atrial appendage site. Despite shortening in conduction interval the morphology of the right atrial appendage electrogram was completely or almost identical to that during orthodromic tachycardia, indicating an atypical form of the fourth criterion. This criterion was not demonstrated in patients with left posterior accessory pathways. Thus, atypical fourth entrainment criterion was demonstrated during overdrive pacing of orthodromic tachycardia from the proximal coronary sinus only in patients with left anterior accessory path ways. Demonstration of atypical fourth criterion seems largely dependent on the location of the accessory pathway, the pacing, and the recording sites.  相似文献   
997.
Protein tyrosine phosphatase ζ (PTPζRPTPβ) is a proteoglycan-type receptor-like protein tyrosine phosphatase specifically expressed in the brain. In addition to the transmembrane form (PTPζ-A), the extracellular splice variant (PTPζ-S) occurs as a major soluble chondroitin sulphate proteoglycan in the brain. We prepared antibodies which specifically recognize PTPζ-A and -S, and analysed the carbohydrate structures on the two PTPζ isoforms in the developing chick brain. lmmunoprecipitation experiments using these antibodies revealed that almost all of the keratan sulphate recognized by a monoclonal antibody (5D4) was exclusively bound to PTPζ-A and PTPζ-S. Addition of keratan sulphate to these proteoglycans markedly increased from embryonic day (E) 11, in contrast to the addition of LeX and HNK-1 carbohydrates, which gradually increased during development in accordance with expression of the core proteins, suggesting that keratan sulphate modification plays some specific roles. Moreover, at the early embryonic stage keratan sulphate was observed only in several restricted regions, especially at boundary regions such as the roof plate of the tectum, the zona limitans intrathalamica in the diencephalon, and the mesencephalon-metencephalon boundary. At the mesencephalon-metencephalon boundary, keratan sulphate modification of PTPζ isoforms was specifically observed from E3 to E6 on a ring of cells encircling the neural tube and their radially oriented processes, which were identified as radial glial fibres. This expression pattern of keratan sulphate spatiotemporally corresponded well to the formation of the fovea isthmi, a groove separating the mesencephalon from the metencephalon. These results suggest that carbohydrates including keratan sulphate on PTPζ isoforms play important roles in brain development by modulating the cell-cell and/or cell-substrate interactions mediated by these molecules.  相似文献   
998.
999.
应用蒙特卡洛法仿真辐射式金属换热器内的辐射传热过程,建立了换热器综合传热的数学模型,利用概率论原理,把辐射能迁移过程仿真为一定累积概率分面下的随机过程,该模型能较好地反映换热器内传热过程的真实情况,可以计算出换热器内烟气、筒壁、空气的温度和壁面热流分布,以及研究烟气进口温度、换热器筒径和狭逢宽度对换热效果的影响。  相似文献   
1000.
Anti-Ro sera immunoprecipitate Ro ribonucleoproteins (RNPs) from human cell extracts. Ro RNPs are biochemically heterogeneous particles whose functions are unknown and whose exact composition remains controversial. In addition to 60-kD Ro and to La proteins, a 52-kD polypeptide (p52) has been proposed to be a stable component of the Ro RNPs. To confirm the immunological studies supporting this hypothesis, we have biochemically purified Ro RNPs from HeLa cells using non-denaturing conditions. Ro RNPs segregated into three distinct populations, one of which only contained hY5 RNA (RohY5 RNPs). No p52 co-purified with Ro RNPs. Despite the absence of p52, purified Ro RNPs had biochemical and immunological properties identical to those of unfractionated Ro RNPs. Many anti-Ro sera only recognize p52 in immunoblots, and are said to be monospecific anti-p52. Preincubation with purified RohY5 RNPs (free of p52) of all human anti-Ro (including so-called monospecific anti-p52) sera abolished their capacity to immunoprecipitate Ro RNPs from unfractionated HeLa cell extracts. Conversely, preincubation of anti-Ro sera with purified p52 protein specifically inhibited recognition of p52 in immunoblots, but did not interfere with immunoprecipitation of Ro RNPs. Our data demonstrate that anti-p52 antibodies do not target intact Ro RNPs, nor do they target the native 60-kD Ro protein. Contrary to previous reports, p52 protein is not a stable component of antigenically intact Ro RNPs.  相似文献   
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