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101.
用细胞内HRP染色的方法显示该神经元位于猫运动皮层十字沟后,在第Ⅱ/Ⅲ层之间(软膜以下438μm处),胞体截面积为15.6×28.1μm~2,呈多极形,树突呈串珠状,向四周扩展,无侧棘,轴突由胞体下方伸出,返折向上,包绕胞体周围,以软膜平行的吻尾方向行走为主,有一分枝向白质方向延伸.从立体重构图的不同角度观察,其形态不对称,如沿X轴方向旋转60°后,其形态呈扁平形,用胶体金免疫电镜观察,该神经元的递质性质为GABA能的.胞体及树突上分布有非对称型和对称型的突触,对称型的突触中有的是GABA能的,有的是非GABA能的.其轴突有髓鞘包绕,末梢与其它神经元的胞体形成一处以上相连或不相连的对称型突触,也可与其它树突形成对称型的突触.根据该神经元的形态,递质性质及突触分布的特征,可确认它是篮状细胞.  相似文献   
102.
M_φ介导的对肿瘤细胞的杀伤过程主要分三个步骤:(a)体内或体外对M_φ的激活;(b)效应细胞与靶细胞的紧密接触、即结合;(c)靶细胞的溶解,即效应细胞对靶细胞的杀伤。一般认为,效应细胞与靶细胞的结合是杀伤的先决条件。在肿瘤发  相似文献   
103.
Somatic mitochondrial mutation in gastric cancer.   总被引:11,自引:1,他引:11       下载免费PDF全文
Likely hot spots for mutations are mitochondrial sequences as there is less repair and more damage by carcinogens compared with nuclear sequences. A somatic 50-bp mitochondrial D-loop deletion was detected in four gastric adenocarcinomas. The deletion included the CSB2 region and was flanked by 9-bp direct repeats. The deletion was more frequent in adenocarcinomas arising from the gastroesophageal junction (4/32, 12.5%) compared with more distal tumors (0/45). Topographical analysis revealed the absence of the deletion from normal tissues except in focal portions of smooth muscle in one case. In two cases, apparent mutant homoplasmy was present throughout two tumors, including their metastases. In the two other cases, the mutation was present in only minor focal portions ( < 5%) of their primary tumors. These findings document the presence of somatic mitochondrial alterations in gastric cancer, which may reflect the environmental and genetic influences operative during tumor progression.  相似文献   
104.
Oxidative damage to mitochondrial DNA (mtDNA) increases with age in the brain and can induce G:C to T:A and T:A to G:C point mutations. Though rare at any particular site, multiple somatic mtDNA mutations induced by oxidative damage or by other mechanisms may accumulate with age in the brain and thus could play a role in aging and neurodegenerative diseases. However, no prior study has quantified the total burden of mtDNA point mutation subtypes in the brain. Using a highly sensitive cloning and sequencing strategy, we find that the aggregate levels of G:C to T:A and T:A to G:C transversions and of all point mutations increase with age in the frontal cortex (FCtx). In the substantia nigra (SN), the aggregate levels of point mutations in young controls are similar to the levels in the SN or FCtx of elderly subjects. Extrapolation from our data suggests an average of 2.7 (FCtx) to 3.2 (SN) somatic point mutations per mitochondrial genome in elderly subjects. There were no significant differences between Parkinson's disease (PD) patients and age-matched controls in somatic mutation levels. These results indicate that individually rare mtDNA point mutations reach a high aggregate burden in FCtx and SN of elderly subjects.  相似文献   
105.
The anatomical relationships between pro-opiomelanocortin-containing axons and serotonin neurons in the nucleus raphe dorsalis (NRD) of the rat were examined at the light microscope level with antibodies against CLIP (corticotropin-like intermediate lobe peptide), alpha-MSH (alpha-melanocyte-stimulating hormone) and serotonin. Sequential double labeling was performed with either immunofluorescence or peroxidase-antiperoxidase techniques. It was observed that the network of POMC-immunoreactive axons displayed a gradient of decreasing density from rostral to caudal levels and from dorsal to ventral parts or the NRD. The examples of close proximity between immunoreactive axons and serotonin cell bodies or dendrites were rather scarce. On the whole, the immunoreactive fibers seemed to run quasi-independently of the serotonin neurons.  相似文献   
106.
调查了90具童尸用状腺的基本形态,可分四型。其中以甲状腺由两侧叶及峡部组成者为最多,占50.22%。测量了甲状腺各部的长、宽、厚。分年龄组进行了数据的统计学处理,并计算出儿童与成人甲状腺各部相应值的百分比。结果显示:小儿甲状腺侧叶的长度和宽度在幼儿期(1—3岁)就已发育近成人的一半。随着年龄的增长,甲状腺各部的均值逐渐增加。除各部的宽度以及锥体叶的长度外,各相邻两组间同项均数的比较,经双侧T检验发现差异具有高度显著性(P<0.01)。  相似文献   
107.
Recently genotyping of JC virus (JCV) DNA in renal tissue was reported to be useful to identify the geographic origin of unidentified cadavers. In the above study, autopsied tissue samples without storage or stored in a frozen state were used. This study examined JCV DNA sequence modifications caused by formalin-fixation, in an attempt to elucidate whether formalin-fixed, paraffin-embedded tissue samples can also be used to determine the genotypes of JCV DNA in the kidney. In four cases, a 610 bp typing region of the JCV genome was PCR-amplified from renal tissues stored for 1 year in three different states: frozen at -80 degrees C [Amaker, B.H., Chandler, F.W., Huey, L.O., Colwell, R.M., 1997. Molecular detection of JC virus in embalmed, formalin-fixed, paraffin-embedded brain tissue. J. Forensic Sci., 1157-1159], formalin-fixed, paraffin-embedded [Ault, G.S., Stoner, G.L., 1992. Two major types of JC virus defined in progressive multifocal leukoencephalopathy brain by early and late coding region DNA sequences. J. Gen. Virol. 73, 2669-2678], and soaked in 5% formalin [Baksh, F.K., Finkelstein, S.D., Swalskey, P.A., Stoner, G.L., Ryschkewitsch, C.F., Randhawa, P.R., 2001. Molecular genotyping of BK and JC virus in human polyomavirus-associated interstitial nephritis after renal transplantation. Am. J. Kidney Dis. 38 (2), 354-365]. The amplified fragments were cloned, and the resultant clones were sequenced. In frozen samples, single sequences ('original' sequences) were detected in all cases. In formalin-fixed, paraffin-embedded samples, not only the original sequences but also those with 1-6 base substitutions were detected. From formalin-soaked samples, the original sequences and those with 1-5 and 10-13 substitutions were detected. The genotyping of JCV DNA was not hampered by the presence of 1-6 substitutions, but a shift in JCV genotypes was observed in sequences with 10-13 substitutions. Thus, it was concluded that the genotypes of JCV DNA in the kidney can be determined only with specimens stored in a frozen state or formalin-fixed for a short time.  相似文献   
108.
应用细胞原位杂交技术,观察经重组小鼠白细胞介素-19(IL-1β)处理后的体外培养的新生1d大鼠中脑黑质神经元c-jun基因的表达.结果显示,培养的黑质细胞多为酪氨酸羟化酶阳性神经元,IL-1β可诱导体外培养的黑质神经元c-junmRNA表达,高水平的表达出现在IL-1β处理后2~4h。说明IL-1β有兴奋黑质神经元的作用,并提示黑质神经元上可能存在IL-1β受体.  相似文献   
109.
采用半固体一步单层琼脂培养法和单克隆荧光抗体技术分别观察重症肝炎外周血TL-CFU和mIL-2R,发现重症肝炎患者TL-CFU(104.4±32.6)及mIL-2R(35.6±8.6)较正常人明显降低。在培养体系中加胎肝细胞质液后,无论在重症肝炎组还是在正常组均不能明显地提高TL-CFU,说明胎肝细胞质液不含具生物佐的促TL-CFU因子。但对mIL-2R表达的影响,在重症肝炎组病人,只有在PHA存在条件下才能促进mIL-2R的表达,说明胎肝细胞质波含有某种(些)物质能协同PHA促进重症肝炎患者外周血淋巴细胞mIL-2R表达。  相似文献   
110.
黄皮酰胺促钾通道开放   总被引:1,自引:0,他引:1  
一种新发现的具有促智作用的药物——黄皮酰胺能抑制去甲肾上腺素(NE)或KCl引起的血管平滑肌收缩。本研究旨在应用膜片钳(patch clamp)技术探讨黄皮酰胺对Wistar大鼠尾动脉平滑肌细胞膜钾离子通道的作用。单个平滑肌细胞用酶法分离,以细胞封接方式记录离子通道活动。在细胞池内注入2μM黄皮酰胺后,钾离子通道活动明显增强。用本实验室开发的计算机软件(patch clamp analysis system,Version 1.0)计算分析通道活动的特征参数。  相似文献   
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