包埋前免疫电镜双标技术在神经解剖学研究中的应用

目的　在超微结构水平观察两种神经递质在纤维终末内的共存或一种神经递质与其相应受体之间的关系。　方法　包埋前免疫电镜双重标记技术———酶标法和免疫金 银标记法相结合的方法。　结果　在免疫反应双重标记的纹状体切片上 ,电镜下观察到大量的SP样 (过氧化物酶免疫反应产物 )阳性终末和SP受体 (SPR ,免疫金 银标记颗粒 )样阳性神经元的胞体和树突 ,同时可见部分SP样阳性轴突终末分别与SPR样阳性神经元的胞体或树突形成对称性轴 体或轴 树突触联系。而在三叉神经脊束核尾侧亚核切片上 ,电镜下可观察到大量的两种囊泡膜谷氨酸转运体 ,即DNPI样 (过氧化物酶免疫反应产物 )和VGluT1样 (免疫金 银标记颗粒 )阳性轴突终末 ,同时还观察到DNPI样和VGluT1样双标的轴突终末与阴性树突形成非对称性突触。　结论　包埋前免疫电镜双重标记技术敏感性较高 ,组织的抗原性保存好 ,特别是在神经解剖学研究中 ,用于研究两种神经递质在同一个细胞或终末内的共存或分析神经递质与其相应受体之间的联系中有独到之处。     

Supradiaphragmatic ectopic adrenocorticotropic hormone-secreting adenoma

A 22-year-old woman with Cushing's syndrome, caused by an extremely rare suprasellar ectopic pituitary adenoma, is presented. Magnetic resonance imaging and computed tomography revealed a well-circumscribed mass in the right suprasellar region. Endocrinological tests showed elevated s-adrenocorticotropic hormone level and hypercortisolemia. The tumor was totally removed by right subfrontal approach. At the time of the operation, the tumor was in continuity with the distal pituitary stalk but not with the pituitary gland. The diaphragma sellae was intact. Histologic diagnosis of the tumor specimen was confirmed as a pituitary adenoma. After surgical removal of the tumor, continued improvement in the patient's laboratory results and disappearance of her endocrine symptoms strongly indicated the absence of adenoma cells in the pituitary gland or stalk. Six years post-surgery, there was no evidence of recurrence in the patient's clinical and laboratory examination. This tumor probably originated from aberrant anterior pituitary cells of the pituitary stalk.     

消化道平滑肌肿瘤超微结构观察

对20例消化道平滑肌肿瘤的电镜观察,发现并非所有病例均具有平滑肌细胞超微结构特征。7例见有肌微丝及相应的致密体,5例见有胞膜下增厚的致密斑,4例见有胞膜下吞饮小泡及膜外间断基底膜。上述改变出现于4例平滑肌瘤中的3例,10例高分化平滑肌肉瘤中的4例,6例分化较差平滑肌肉瘤及1例上皮样平滑肌瘤未发现。其他如内质网的扩张、线粒体的变形及糖元核醣体的广泛分布等改变亦可见到。     

Cyr61 protects against hyperoxia-induced cell death via Akt pathway in pulmonary epithelial cells

We have used gene expression profiling approaches to identify new molecular targets in various models of lung injury and human lung diseases. Among the many genes that are significantly induced in these studies, cysteine-rich61 (Cyr61) consistently ranks as one of the most significant genes. Here, we use the well-established model of hyperoxia to better understand the function of Cyr61 in acute lung injury. Cyr61, a stress-related immediate-early response gene, has known diverse functions involving angiogenesis, tumorigenesis, and wound repair. It belongs to the newly discovered "CCN" family containing six growth and regulatory factors. We showed that hyperoxia induces Cyr61 expression in a variety of pulmonary cells and in lung tissue in vivo. Loss of function studies, by suppressing Cyr61 expression by siRNA, accelerated lung epithelial cell death after hyperoxia. Gain of function studies, by overexpressing Cyr61, significantly conferred increased resistance to hyperoxia-induced cell death. Moreover, cells overexpressing Cyr61 induce Akt activation. Inhibition of Akt by siRNA abrogated the protective effects of Cyr61-overexpressing cells in response to hyperoxia. Taken together, our data demonstrate that Cyr61 expression provides cytoprotection in hyperoxia-induced pulmonary epithelial cell death and that this effect was in part mediated via the Akt signaling pathway.     

T-cell epitopes in variable segments of Chlamydia trachomatis major outer membrane protein elicit serovar-specific immune responses in infected humans

We previously identified 18 stimulatory Chlamydia trachomatis major outer membrane protein (MOMP) peptides containing at least 23 epitopes presented with various HLA class II allotypes. Only one peptide contained an epitope localized in a variable segment (VS2). Continued studies reported here identified a total of five VS peptides containing T-cell epitopes that are distributed among MOMPs VS1, VS2, and VS4. Only MOMP-primed T-cell cultures from subjects infected with serovar E responded to the serovar E VS peptides, while the response of such cultures to constant-segment peptides was independent of the infecting serovar. Furthermore, MOMP-primed T cells proliferated in response only to the VS peptides encoded in serovar E but not to the corresponding peptides derived from serovar F, I, or J, confirming that these responses were serovar specific.     

Voltage-sensitive calcium channels in a human small-cell lung cancer cell line.

Utilizing the whole-cell patch-clamp method we assessed the Ca2+ current (ICa) in well-established cell lines from human small-cell carcinoma (SCC) of the lung, NCI-H209 and NCI-H187. The Ca2+ current was readily observed in H209 tumour cells (90% of the cells tested), whereas H187 tumour cells only occasionally expressed Ca2+ channels (26% of the cells tested). H209 Ca2+ current was evoked by potentials greater than -30 mV and exhibited partial inactivation over the duration of a 40 ms command potential. This inward current was unchanged by alteration of the holding potential from -80 to -40 mV and the activation phase of the Ca2+ current was best fitted by Hodgkin-Huxley m(t)2 kinetics. H209 Ca2+ current was reduced over 80% by verapamil (100 microM), whereas w-conotoxin (5 microM) appeared to be without effect. In contrast, H209 Ca2+ current was rapidly abolished by nifedipine (10 microM), strongly suggesting the presence of L-type Ca2+ channels. Voltage-gated Ca2+ channels may be important to the secretion of ectopic hormones and the etiology and pathogenesis of Lambert-Eaton syndrome, an autoimmune disorder of the motor nerve terminal in which autoantibodies directed against voltage-gated Ca2+ channels are produced.     

Colorectal adenocarcinoma as a second malignant neoplasm following rhabdomyosarcoma of the urinary bladder: a case report

Following improvements in therapy for childhood malignancies, the striking increase in survival rate over the past 30 years has led to the increase risk of developing second malignant neoplasms (SMNs). We report a case of colorectal carcinoma as a SMN, following treatment for rhabdomyosarcoma. The patient was diagnosed with rhabdomyosarcoma of the urinary bladder at his age of three years, and developed adenocarcinoma in the colon 13 years later. Histologic examination of the surgical specimen revealed adenocarcinoma involving the rectosigmoid area with radiation colitis in its background. The tumor cells showed strong immunoreactivity for p53 protein, suggesting the role of irradiation and p53 mutation in carcinogenesis. This case emphasizes the need for dose observation in survivors of early childhood malignancies treated with radiation and multiagent chemotherapy.     

hTRT催化功能区基因克隆及其在肿瘤中的表达

目的 研究端粒酶蛋白ｈＴＲＴ基因在肿瘤中的表达及其意义。方法 用ＲＴ－ＰＣＲ法检查Ｈｅｌａ细胞与ＰＧ细胞的ｈＴＲＴ表达水平,将Ｈｅｌａ细胞的ｈＴＲＴ催化功能克隆,并进行测序比较,应用原位杂交技术对肿瘤组织中的ｈＴＲＴ和ｈＴＲ（端粒酶ＲＮＡ组分）基因进行检测。结果 Ｈｅｌａ细胞与ＰＧ细胞均有ｈＴＲＴ表达,Ｈｅｌａ细胞ｈＴＲＴ催化功能区ｃＤＮＡ序列与文献报道一致,原位杂交结果显示ｈＴＲＴ与ｈＴＲ的协同     

Activation of Src tyrosine kinase in microglia in the rat hippocampus following transient forebrain ischemia

To better understand the pathophysiological role of Src protein, a non-receptor protein tyrosine kinase of 60kDa, in the ischemic brain, we investigated the time course and regional distribution of active Src expression by using a specific antibody against Tyr416 phosphorylated Src (phospho-Src) in the rat hippocampus after transient forebrain ischemia. In the hippocampus of the control animals, active Src expression was too low to be detected by immunolabeling. Beginning 4h after reperfusion, active Src expression became evident and, after 1 day, had increased preferentially in the CA field of the hippocampus proper and the dentate gyrus. By day 3, active Src expression markedly increased in the pyramidal cell layer of CA1 and the dentate hilar region in temporal correlation with neuronal cell death occurring in these areas, where cells typical of phagocytic microglia showed phospho-Src immunoreactivity. Double-labeling experiments revealed that cells expressing active Src were microglia that stained for biotinylated lectin derived from Griffonia simplicifolia (GSI-B4). Active Src expression began to decline at day 7 and returned to the basal level by day 14 after reperfusion. These results demonstrate increased phosphorylation of Src in activated microglia of the post-ischemic hippocampus, indicating that Src signaling may be involved in the microglial reaction to an ischemic insult.