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991.
Summary All rodent oral epithelia are orthokeratinized. However, morphological, immunohistochemical and biochemical studies have shown that regional differences exist. In the present study, intraregional variations in differentiation patterns of rat oral epithelia are demonstrated using monoclonal anti-keratin antibodies AE1 and AE2 and antibodies to blood group antigens B and H. Well-defined areas of rat buccal and hard palate epithelium differed from the general staining patterns of these epithelia. These areas were associated with a papillary surface contour. These local variations were not found in the strain of mice examined. The results suggest that physiologically different vertical compartments of keratinocytes exist within one and the same region of rat oral mucosa, a phenomenon previously recognized in detail only in the epithelium of dorsal tongue. The papillary structures may have some functional significance related to the processing of food similar to that suggested for lingual filiform papillae.  相似文献   
992.
目的:探讨静脉注射乌拉地尔与硝酸甘油微泵对高血压患者拔牙术中血压及心率(HR)的影响。方法:选择自2015年1月到2016年10月在我院进行心电监护拔牙的高血压患者116例纳入本次研究,根据随机数字表法将患者分成观察组以及对照组各58例,对照组给予硝酸甘油加泵静点维持,观察组给予乌拉地尔加泵静点维持,对比两组术前、麻醉时、麻醉后10min、术中及术后10min收缩压(SBP)、舒张压(DBP)以及HR的变化,并对比两组不良反应情况。结果:两组术中及术后10min的SBP和DBP水平均分别明显低于术前,观察组术中的SBP和DBP水平均分别明显低于对照组,差异均有统计学意义(P0.05);对照组术中及术后10min的HR均明显高于术前,且观察组均明显低于对照组,差异均有统计学意义(P0.05)。观察组不良反应的总发生率是6.90%(4/58),与对照组的10.34%(6/58)相比,差异无统计学意义(P0.05)。结论:静脉注射乌拉地尔对高血压患者在拔牙术中血压及HR的影响较小,安全性较好,值得推广。  相似文献   
993.
C-type natriuretic peptide (CNP), a member of the family of natriuretic peptides, is synthesized and secreted from monocytes and macrophages that resulted to be a source of CNP at inflammatory sites. This suggests that special attention should be focused on the possible role of CNP in the immune system, in addition to its effects on the cardiovascular system. The aim of this study was to evaluate the possibility of measuring the mRNA expression of CNP and NPR-B, its specific receptor, in human whole blood samples of healthy (N; n=7) and heart failure (HF; n=7) subjects by Real-Time PCR (RT-PCR). Total RNA was extracted from leukocytes with QIAamp RNA Blood Kit and/or with PAXgene Blood RNA Kit. RT-PCR was performed and optimized for each primer. The experimental results were normalized with the three most stably expressed genes. CNP and NPR-B expression trend was similar in both fresh and frozen human whole blood. Significant higher levels of CNP and NPR-B mRNA expression were found in HF patients with respect to controls (CNP: N=1.23±0.33 vs. HF=6.54±2.09 p=0.027; NPR-B: N=0.85±0.23 vs. HF=5.31±1.98 p=0.04). A significant correlation between CNP and NPR-B (r=0.86, p<0.0001) was observed. Further studies are needed to clarify the pathophysiological properties of this peptide but the possibility to measure CNP and NPR-B mRNA expression in human leukocytes with a fast and easy procedure is a useful starting point for future investigation devoted to better understand the biomolecular processes associated to different diseases.  相似文献   
994.
Summary Human and rabbit erythroid and granulocytic precursors in bone marrow have been investigated to provide information concerning the number of nucleolar silverstained granules (SSGs), which represent active interphasic nucleolar organizer regions (NORs). The differentiation and maturation of precursor cells of both investigated cell lines are characterized by a gradual decrease in number of nucleolar SSGs. In advanced maturation stages of erythroblasts or granulocytes, which are known to lose the capacity to divide, the number of nucleolar SSGs is smaller than the reported average or maximal values of NORs determined for human or rabbit cells. Since committed stem cells from both cell lines contain several times the number of nucleolar SSGs than the last dividing maturation and differentiation stages, the number of active parts of interphasic NORs in committed stem cells seems to be increased and might represent a stock for the later stages. In addition, the number of nucleolar SSGs appear to be a very convenient marker of nucleolar biosynthetic activity in individual differentiating and maturing blood cells. The differences between erythroid and granulocytic stem cells with respect to the number of nucleolar SSGs disappear during the course of further differentiation and maturation.  相似文献   
995.
Thrombin participates in coagulation, anticoagulation, and initiation of platelet activation. To fulfill its diverse roles and maintain hemostasis, this serine protease is regulated via the extended active site region and anion-binding exosites (ABEs) I and II. For the current project, amide proton hydrogen-deuterium exchange coupled with MALDI-TOF mass spectrometry was used to characterize ligand binding to individual exosites and to investigate the presence of exosite-active site and exosite-exosite interactions. PAR3(44–56) and PAR1(49–62) were observed to bind to thrombin ABE I and then to exhibit long range effects over to ABE II. By contrast, Hirudin(54–65) focused more on ABE I and did not transmit influences over to ABE II. Although these three ligands were each directed to ABE I, they did not promote the same conformational consequences. d-Phe-Pro-Arg-chloromethyl ketone inhibition at the thrombin active site led to further local and long range consequences to thrombin-ABE I ligand complexes with the autolysis loop often most affected. When Hirudin(54–65) was bound to ABE I, it was still possible to bind GpIbα(269–286) or fibrinogen γ′(410–427) to ABE II. Each ligand exerted its predominant influences on thrombin and also allowed interexosite communication. The results obtained support the proposal that thrombin is a highly dynamic protein. The transmission of ligand-specific local and long range conformational events is proposed to help regulate this multifunctional enzyme.  相似文献   
996.
Compound ITH33/IQM9.21 (ITH/IQM) belongs to a new family of l-glutamic acid derivatives with antioxidant and neuroprotective properties on in vitro and in vivo models of stroke. Because neuronal damage after brain ischemia is tightly linked to excess Ca2+ entry and neuronal Ca2+ overload, we have investigated whether compound ITH/IQM antagonises the elevations of the cytosolic Ca2+ concentrations ([Ca2+]c) and the ensuing exocytotic responses triggered by depolarisation of bovine chromaffin cells. In fluo-4-loaded cell populations, ITH/IQM reduced the K+-evoked [Ca2+]c transients with an IC50 of 5.31 μM. At 10 μM, the compound decreased the amplitude and area of the Ca2+ transient elicited by challenging single fura-2-loaded cells with high K+, by 40% and 80%, respectively. This concentration also caused a blockade of K+-induced catecholamine release at the single-cell level (78%) and cell populations (55%). These effects are likely due to blockade of the whole-cell inward Ca2+ currents (IC50 = 6.52 μM). At 10 μM, ITH/IQM also inhibited the Ca2+-dependent outward K+ current, leaving untouched the voltage-dependent component of IK. The inward Na+ current was unaffected. Inhibition of depolarisation-elicited Ca2+ entry, [Ca2+]c elevation and exocytosis could contribute to the neuroprotective effects of ITH/IQM in vulnerable neurons undergoing depolarisation during brain ischemia.  相似文献   
997.
许涛  钱琛  汪远金 《生物学杂志》2000,17(6):24-24,23
用腺嘌呤复制动物性慢性肾功能衰竭(CRF)模型。观察大鼠血浆血尿素氮(BuN)、血肌酐(Cr)、血红蛋白(Hb)、超氧化物歧化酶(SOD)和中分子物质(MMS)总量的变化。结果表明,CRF大鼠血浆BuN、Cr和MMS总量明显升高(P〈0.01)、Hb和SOD含量显著降低(P〈0.01)。提示CRF大鼠MMS总量升高、SOD活性降低。  相似文献   
998.
非同位素PCR-SSCP方法的初步临床应用   总被引:1,自引:0,他引:1  
单链构象多态性检测法 (PCR-SSCP)是近年发展起来的一项检测人类基因组 突变的新技术。然而,在该技术中需要使用放射性同位素标记的核苷酸或引物,从而限制 了其广泛临床研究及诊断方面的应用。本文报告一种改进的PCR-SSCP方法, 该方法不用 同位素标记引物,而直接在溴乙啶染色的聚丙烯酰胺凝胶上显示SSCP。用该方法对55例 平滑肌肉瘤p53基因第7外显子突变的检测表明,38%的瘤组织DNA存在异常的SSCP。其中10例有HaeⅢ和MspⅠ酶切位点的突变(18%), 19例有突变型p53蛋白的过度表达(9例同时有异常SSCP改变)。而p53质粒D NA,平滑肌瘤及Alzheimer病患者基因组DNA无p53基因第7外显子扩增片段的异常SSCP改变。同时,还使用该方法对临床诊断的20例Alzheimer病患者和8例健康对照进行了β-淀粉样蛋白前体基因第16和17外显子的扩增及分析,均未发现有异常SSCP改变及EcoRⅠ,BclⅠ酶切位点的突变。本研究结果提示,该非同位素PCR-SSCP方法可靠、敏感、简便、快速,具有潜在的推广价值。  相似文献   
999.
The present study investigated the mechanism of diving bradycardia. A group of 14 healthy untrained male subjects were examined during breath-holding either out of the water (30–33°C), in head-out immersion, or in whole-body submersion (27–29°C) in a diving pool. Blood velocity, blood volume flow in the carotid artery, diastolic blood pressure and electrocardiogram were measured and recorded during the experiments. The peak blood velocity increased by 13.6% (P < 0.01) and R-wave amplitude increased by 57.1% (P < 0.005) when the subjects entered water from air. End-diastolic blood velocity in the carotid artery increased significantly during breath-holding, e.g. increased from 0.20 (SD 0.02) m · s−1 at rest to 0.33 (SD 0.04) m · s−1 (P < 0.001) at 50.0 s in breath-hold submersion to a 2.0-m depth. Blood volume flow in the carotid artery increased by 26.6% (P < 0.05) at 30 s and 36.6% (P < 0.001) at 40 s in breath-hold submersion to a 2.0-m depth. Diastolic blood pressure increased by 15.4% (P < 0.01) at 60 s during breath-holding in head-out immersion. Blood volume flow, and diastolic blood pressure increased significantly more and faster during breath-holding in submersion than out of the water. There was a good negative correlation with the heart rate: the root mean square correlation coefficient r was 0.73 (P < 0.001). It was concluded that an increased accumulation of blood in the aorta and arteries at end-diastole and decreased venous return, caused by an increase in systemic peripheral resistance during breath-holding, underlies diving bradycardia. Accepted: 22 November 1996  相似文献   
1000.
研究了克雷伯肺炎杆菌(Klebsiella pneumoniae)批式流加发酵生产1,3-丙二醇的发酵工艺,根据1,3-丙二醇的生产和菌体生长相关的特点,采用营养基质限制性流加的发酵工艺,通过控制氮源氯化铵以保持细胞稳定生长。结果表明:过低的氮源浓度,细胞生长受到限制,影响产物1,3-PD的合成;过高的氮源浓度,细胞比生长速率增加,但1,3-PD关于消耗甘油的得率降低,用于生长和维持代谢所消耗的甘油量增加。以0.41 g/(L·h)的氮源流加速率,残余氯化铵浓度在0.1 g/L时,转化率和生产强度最高。发酵25 h~28 h后,1,3-丙二醇最终浓度达到52.03 g/L,生产强度为2.04 g/(L·h),相对于甘油的摩尔转化率为0.66,分别比氮源限制前提高了28.0 %、35.1 %及29.4 %。通过限制性流加氯化铵,控制细胞的比生长速率,使底物甘油有效转变为发酵的目标产物1,3-PD,有效实现产物1,3-PD的高生产强度以及对甘油的高转化率。  相似文献   
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