左结肠动脉的应用解剖

在88例左半结肠标本上,观察了左结肠动脉。根据其行走位置不同,分为内侧型和外侧型。按左结肠动脉分叉点的高度不同又分为高位组、中位组和低位组。左结肠动脉分支中有一种直血管,向左连于降结肠的缘动脉,这些血管在作肠修复时,对促进左半结肠的血供有重要意义。根据左结肠动脉的解剖特点,提出了裁剪左半结肠时,切断左结肠动脉的要点。     

雷公藤红素对人肥大细胞系粘附能力和粘附分子表达的影响

雷公藤红素是雷公藤单体之一.本文研究雷公藤红素对人肥大细胞系HMC-1细胞粘附及粘附分子表达的影响.结果发现:HMC-1细胞能自发地表达β1、β3型整合素和CD44,不表达β2型整合素,具有迅速粘附于鼠尾胶的能力,在粘附过程中细胞由圆形、椭圆形变成梭形、多极形.雷公藤红素与HMC-1细胞在粘附前或粘附后共育均能以剂量和时间依赖方式抑制粘附和粘附过程中细胞形态的变化,并可下调粘附分子的表达.提示:雷公藤红素能抑制HMC-1细胞的粘附,这一作用与其抑制粘附分子表达和细胞形态的改变有关.     

Implantation of bone marrow mononuclear cells using injectable fibrin matrix enhances neovascularization in infarcted myocardium

Neovascularization may improve cardiac function and prevent further scar tissue formation in infarcted myocardium. A number of studies have demonstrated that bone marrow-derived cells have the potential to induce neovascularization in ischemic tissues. In this study, we hypothesized that implantation of bone marrow mononuclear cells (BMMNCs) using injectable fibrin matrix further enhances neovascularization in infarcted myocardium compared to BMMNC implantation without matrix. To test this hypothesis, infarction was induced in rat myocardium by cryoinjury. Three weeks later, rat BMMNCs were mixed with fibrin matrix and injected into the infarcted myocardium. Injection of either BMMNCs or medium alone into infarcted myocardium served as controls. Eight weeks after the treatments, histological analyses indicated that implantation of BMMNCs using fibrin matrix resulted in more extensive tissue regeneration in the infarcted myocardium compared to BMMNC implantation without matrix. Examination with fluorescence microscopy revealed that cells labeled with a fluorescent dye prior to implantation survived in the infarcted myocardium at 8 weeks of implantation. Importantly, implantation of BMMNCs using fibrin matrix resulted in much more extensive neovascularization in infarcted myocardium than BMMNC implantation without matrix. The microvessel density in infarcted myocardium was significantly higher (p < 0.05) when BMMNCs were implanted using fibrin matrix (350 +/- 22 microvessels/mm2) compared to BMMNC implantation without matrix (262 +/- 13 microvessels/mm2) and medium injection (76 +/- 9 microvessels/mm2). In addition, average internal diameter of microvessels was significantly larger (p < 0.05) in BMMNC implantation with fibrin matrix group (14.6 +/- 1.2 microm) than BMMNC implantation without matrix group (10.2 +/- 0.7 microm) and medium injection group (7.3 +/- 0.5 microm). These results suggest that fibrin matrix could serve as a cell implantation matrix that enhances neovascularization efficacy for myocardial infarction treatment.     

Immunohistochemical analysis of Smac/DIABLO expression in human carcinomas and sarcomas

Second mitochondria-derived activator of caspases (Smac/DIABLO) is released from mitochondria into the cytosol during apoptosis, promoting caspase activation by neutralizing the inhibition of inhibitor of apoptosis proteins (IAPs) on caspases. Alteration of apoptosis is essential for cancer development, and cancer cell death by radiation and chemotherapy is largely dependent upon apoptosis. In this study, archival tissues of 100 carcinomas and 50 sarcomas from various origins were analyzed by immunohistochemistry for the expression of Smac/DIABLO. Smac/DIABLO immunoreactivity was seen in 62 of 100 (62%) carcinomas, including 42 of 60 stomach carcinomas, 7 of 10 colorectal carcinomas, 4 of 10 lung carcinomas, 7 of 10 ovarian carcinomas, and 2 of 10 prostate carcinomas. Smac/DIABLO is expressed in 11 of 50 (22%) sarcomas, including 2 of 8 malignant schwannomas, 5 of 11 rhabdomyosarcomas, 2 of 7 malignant fibrous histiocytomas, 1 of 6 leiomyosarcomas, 0 of 8 angiosarcomas, 0 of 8 liposarcomas, and 1 of 2 Ewing's sarcomas. These data demonstrated that Smac/DIABLO expression levels vary depending on the individual cancer types. Furthermore, the present study showed that many human cancers do not express Smac/DIABLO, and suggest that lack of Smac/DIABLO expression in the cancer cells may inhibit apoptosis, thereby promoting their survival.     

A novel missense mutation (I344K) in the SPG4gene in a Korean family with autosomal-dominant hereditary spastic paraplegia

 Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower extremities. Among eight loci linked with autosomal-dominant (AD)-HSP, the SPG4 locus on chromosome 2p22 accounts for about 40% of all patients. Recently, mutations in a new member of the AAA protein family, called spastin, have been identified as responsible for SPG4-linked AD-HSP. Here, we describe a novel missense mutation (c.1031T>A; I344K) in exon 7 of the SPG4 gene identified in a Korean family with typical clinical features of pure AD-HSP. The mutation affects the third amino acid of the highly conserved AAA cassette domain, which is the most fore part of the domain altered by a missense mutation reported so far. Clinical presentations of affected individuals carrying the I344K mutation were not different from those of pure AD-HSP with SPG4 mutations reported previously. However, it is noteworthy that neither urinary dysfunction nor involvement of upper extremities was noticed in this family. To our knowledge, this is the first report of genetically confirmed AD-HSP in Korea. Received: February 20, 2002 / Accepted: May 21, 2002     

TRIM5alpha association with cytoplasmic bodies is not required for antiretroviral activity

The tripartite motif (TRIM) protein, TRIM5alpha, restricts infection by particular retroviruses. Many TRIM proteins form cytoplasmic bodies of unknown function. We investigated the relationship between cytoplasmic body formation and the structure and antiretroviral activity of TRIM5alpha. In addition to diffuse cytoplasmic staining, the TRIM5alpha proteins from several primate species were located in cytoplasmic bodies of different sizes; by contrast, TRIM5alpha from spider monkeys did not form cytoplasmic bodies. Despite these differences, all of the TRIM5alpha proteins exhibited the ability to restrict infection by particular retroviruses. Treatment of cells with geldanamycin, an Hsp90 inhibitor, resulted in disappearance or reduction of the TRIM5alpha-associated cytoplasmic bodies, yet exerted little effect on the restriction of retroviral infection. Studies of green fluorescent protein-TRIM5alpha fusion proteins indicated that no TRIM5alpha domain is specifically required for association with cytoplasmic bodies. Apparently, the formation of cytoplasmic bodies is not required for the antiretroviral activity of TRIM5alpha.     

酵母双杂合系统AD端阴离子交换蛋白C-末端表达质粒的构建

利用PCR方法，从阴离子交换蛋白1（AE1）全长cDNA中扩增出约350bp c末端cDNA片段，测序后将其克隆至pGADT7载体上，用醋酸锂法构建好的pADT7-AE1-c末端转染酵母菌HA109，观察其在选择性培养基上的表达情况。结果表明，获得了530bp AE1c－末端cDNA,pGADT7-AE1-c末端对酵母无毒性，不能激活检测基因，可作为酵母双杂合系统中的靶基因。     

Expression of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing rabbits compared with diet-restricted rabbits

The mechanism of body weight loss in the tumor-bearing state is still unclear. In this study, we investigated expressions of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing and diet-restricted rabbits, and tried to evaluate the differences between the two groups. The apoptotic index (AI) in the tumor-bearing group was 28.1+/-2.84 on day 10. By day 20, many more apoptotic cells were found (AI: 40.5+/-3.20), but then after day 20 their numbers gradually decreased (AI: 9.67+/-2.22 on day 30 and 0.93+/-0.96 on day 40). By contrast, no apoptotic cells were detected in the diet-restricted group at any of the times examined. Bcl-2 immunoreactivity was either not detected at all or only weakly observed in both groups. By contrast, Bax expression increased gradually after implantation in the tumor-bearing group. Bax expression in skeletal muscle cell was graded (moderate) 10 days after tumor implantation, and (high) by day 20, in 2 of the 5 tumor-bearing rabbits. After day 20, however, Bax immunoreactivity decreased continuously in the tumor-bearing group. By contrast, hardly any Bax-immuno-positive cells were detected in the diet-restricted group. These results suggest that loss of body weight in the tumor-bearing group is different from that in the diet-restricted group, and is related to apoptosis of skeletal muscles.     

Differential involvement of GABA system in mediating behavioral and neurochemical effect of acupuncture in ethanol-withdrawn rats

In our previous study we demonstrated that acupuncture at Shenmen (HT7) points suppressed a decrease of accumbal dopamine (DA) release in ethanol-withdrawn rats. Furthermore, here we found that it inhibited behavioral withdrawal signs of ethanol. In an effort to better understand the mechanisms underlying this inhibition, the potential role of GABA receptor system in acupuncture was investigated. Male Sprague–Dawley rats were treated with 3 g/kg/day of ethanol (20%, w/v) or saline by intraperitoneal injection for 21 days. Following 48 or 72 h of ethanol withdrawal, acupuncture was applied at bilateral HT7 for 1 min. The selective GABA_A antagonist bicuculline and the selective GABA_B antagonist SCH 50911 were injected intraperitoneally 20 min before acupuncture, respectively. Importantly, suppressive effects of acupuncture on DA deficiency were completely abolished by SCH 50911, but not by bicuculline, whereas ameliorating effects of acupuncture on ethanol withdrawal syndrome were completely blocked either by SCH 50911 or bicuculline. These results suggest that acupuncture at specific acupoint HT7 may normalize the DA release in the mesolimbic system and attenuate withdrawal syndrome through the GABA_B receptor system in ethanol-withdrawn rats.