胃肠道间质瘤的螺旋CT诊断价值

目的：探讨螺旋CT平扫和增强扫描对胃肠道间质瘤（GISTs）的诊断价值。方法：回顾性分析33例经手术、病理及免疫组化证实的GISTs患者螺旋CT表现。结果：平扫33例中，瘤体呈均匀等密度10例，肿块周边呈等密度中间略低或不均匀低密度23例。增强扫描16例中，病灶区呈中度或明显均匀强化9例，不均匀强化并可见囊状改变4例，病灶中央大片状坏死伴周边部明显强化3例。33例中良性9例，肿块直径多小于5cm，且呈圆形、类圆形，规则，边界尚清楚；恶性24例，直径多大于5cm，多数向腔外生长，边界不清楚，5例肿块中有坏死出血，4例发现转移灶。结论：螺旋CT检查对GISTs诊断虽无特异性，但可以准确定位，发现转移灶，显著提高GISTs的检出率，弥补常规胃肠道造影和内窥镜检查的不足，对GISTs术前定位和鉴别诊断均有重要价值。     

Locomotion defects, together with Pins, regulates heterotrimeric G-protein signaling during Drosophila neuroblast asymmetric divisions

Heterotrimeric G proteins mediate asymmetric division of Drosophila neuroblasts. Free Gbetagamma appears to be crucial for the generation of an asymmetric mitotic spindle and consequently daughter cells of distinct size. However, how Gbetagamma is released from the inactive heterotrimer remains unclear. Here we show that Locomotion defects (Loco) interacts and colocalizes with Galphai and, through its GoLoco motif, acts as a guanine nucleotide dissociation inhibitor (GDI) for Galphai. Simultaneous removal of the two GoLoco motif proteins, Loco and Pins, results in defects that are essentially indistinguishable from those observed in Gbeta13F or Ggamma1 mutants, suggesting that Loco and Pins act synergistically to release free Gbetagamma in neuroblasts. Furthermore, the RGS domain of Loco can also accelerate the GTPase activity of Galphai to regulate the equilibrium between the GDP- and the GTP-bound forms of Galphai. Thus, Loco can potentially regulate heterotrimeric G-protein signaling via two distinct modes of action during Drosophila neuroblast asymmetric divisions.     

Pale bodies in hepatocellular carcinoma

Histochemical, immunohistochemical and ultrastructural studies were performed on cases of hepatocellular carcinoma (HCC) with pale bodies (PB). HCC containing PBs was observed in 3 (5.5%) of 55 consecutively resected HCC cases. Histologically, a large number of hepatocytes displayed pale or eosinophilic staining of the cytoplasm, resulting in ground-glass appearance. They were aggregated in nodular pattern, or diffusely intermixed with other malignant hepatocytes. PBs were negative for periodic-acid Schiff and Masson's trichrome staining. The inclusions showed a strong positive reaction for fibrinogen and some of them were weakly positive for albumin but negative for hepatitis B surface antigen, hepatitis B core antigen, alpha-fetoprotein and alpha-1-antitrypsin. Ultrastructurally, PBs were membrane-bound and contained granular materials of moderate electron density, and were closely related to dilated rough endoplasmic reticulum. These findings support that PBs are secretory fibrinogen accumulated in cystic ER and that such intracellular accumulation possibly reflects a defective transport of fibrinogen.     

数值模拟鼻甲的切除对鼻腔内气体流场的影响

量化研究鼻腔结构的变化对鼻腔内气体流场分布的影响.通过CT图像对鼻腔结构进行三维重建并用有限元方法对气体流场进行数值分析.对重建的鼻腔模型的一侧,分别去掉部分中鼻甲和部分下鼻甲并用有限元方法再次进行数值分析,将得到的结果与原始模型进行比较.观察气体流场分布的变化,在两侧鼻腔的流量分布均有变化,在去掉部分鼻甲的一侧流场和气压的分布也有所改变.通过数值模拟,我们量化的显示了鼻腔结构的变化对鼻腔内气体流场分布的影响.     

Adaptation to stress increases the resistance of heart cell nuclei to the damaging action of single-stranded exogenous DNA

Research Institute of General Pathology and Pathophysiology, Academy of Medical Sciences of the USSR, Moscow. Leningrad Institute of Nuclear Physics, Academy of Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 5, pp. 460–462, May, 1991.     

大鼠肺泡巨噬细胞吞噬煤尘颗粒的实验研究

本实验用相差显微电影、溶酶体荧光定位和透射电镜等方法,研究了大鼠离体肺泡巨噬细胞吞噬煤尘的作用,并用二氧化矽和酵母菌作实验对照。结果表明,煤尘颗粒同二氧化矽类似,经过附着,迅速以吞噬体形式被摄入胞浆,而酵母菌呈典型的伪足包围和缓幔吞噬过程。实验证明,用吖啶橙作活细胞溶酶体定位是有效的。被标记的溶酶体发出强橙色荧光。当煤粒吞噬体进入胞浆后,常被多个溶酶体接触包围,形成次级溶酶体。电镜观察提示,煤尘可引起次级溶酶体膜的损害。     

血管内皮损伤标志物在2型糖尿病患者中的变化

目的:探讨2型糖尿病(DM)患者血管内皮损伤标志物的变化。方法:分别测定89例2型DM患者和76例正常对照者血浆可溶性血管内皮细胞蛋白C受体(sEPCR),血管性血友病因子(v WF)和可溶性血栓调节蛋白(sTM),并测定DM患者24h尿白蛋白排泄(UAE),根据尿UAE水平和病程分组进行比较分析。结果:2型DM患者血浆sEPCR、v WF及sTM水平高于正常对照组(P<0.05),并且与其尿UAE水平和病程呈显著正相关。结论:血浆sEPCR、v WF及sTM水平可作为观察2型DM并发血管病变以及严重程度的指标。     

肝外胆道系统管道异常扩张1例

在解剖一成年男性尸体时发现肝外胆道系统(除胆囊外)异常扩张。报道如下:肝脏外形形态正常,肝外胆道各管径变粗,与周围组织无粘连,肝左管、肝右管、肝总管、胆囊管、胆总管的管径异常扩张(表1,图1)。     

低氧导致培养心肌细胞Na+通道基因SCN5A mRNA表达改变

目的研究低氧培养大鼠心肌细胞Na 通道基因SCN5A mRNA表达的变化,并探讨其与丙二醛(M alond ialhyde,MDA)含量及超氧化物歧化酶(superoxide d ismutase,SOD)活性的关系。方法培养大鼠心肌细胞,检测各组培养液氧分压。用RT-PCR检测SCN5A mRNA表达,检测培养液MDA含量和细胞SOD活性。结果与对照组相比:SCN5A mRNA相对表达量低氧1 h和6 h组显著增高(P<0.001)、低氧12 h和24 h组显著降低(P<0.001);MDA含量显著增高而SOD活性显著降低。结论心肌细胞Na 通道基因SCN5A在低氧1 h和6 h mRNA表达上调,而在低氧12 h和24 h mRNA表达下调,且与脂质过氧化和SOD相关。