Effects of resection or bypass of the distal ileum on the lithogenicity of bile

Changes in the composition and lithogenicity of gallbladder bile after resection and bypass of the distal ileum were investigated in the prairie dog. In animals fed a trace cholesterol diet, both ileal resection and ileal bypass increased the cholesterol saturation of bile. In animals fed a cholesterol-enriched diet, the cholesterol saturation was increased by ileal resection but not by ileal bypass. In the animals fed the trace cholesterol diet, both ileal resection and ileal bypass induced the formation of bilirubinate gallstones.     

Development of a prolactin receptor-targeting fusion toxin using a prolactin antagonist and a recombinant form of <Emphasis Type="Italic">Pseudomonas</Emphasis> exotoxin A

Summary Human prolactin (hPRL) promotes the proliferation and differentiation of mammary epithelial cells during mammary gland development and has been linked to breast tumor development. The receptor for hPRL (hPRL-R) is elevated in a majority of human breast tumors, suggesting the overexpression of hPRL-R makes cancer cells highly sensitive to the mitogenic and anti-apoptotic activity of hPRL. These findings provide the rationale for the development of hPRL-R targeting breast cancer therapeutics. Previously, an hPRL-R antagonist, G129R, was developed that competitively binds to the hPRL-R resulting in growth inhibition and the induction of apoptosis in certain types of breast cancer cells. To further increase thepotency of G129R, we fused G129R to a truncated form of Pseudomonas exotoxin A (PE₄₀) that lacks the cell recognition domain of the toxin but retains the domains necessary for PE₄₀_ to translocate into the cytosol and inhibit protein synthesis. We postulated that the fusion of G129R with PE₄₀-KDEL would (1) deliver the recombinant toxin to breast cancer cells where hPRL-R is overexpressed; (2) block hPRL signaling via its G129R moiety; and (3) inhibit protein synthesis via its PE₄₀-KDEL moiety. We demonstrate that the fusion toxin can competitively bind to hPRL-Rs on T-47D human breast cancer cells and inhibit STAT5 phosphorylation induced by hPRL. In addition, we show that G129R-PE₄₀-KDEL is selectively cytotoxic to breast cancer cell lines expressing the hPRL-R and that cell death is associated with the inhibition of protein synthesis and does not involve caspase mediated apoptosis.     

人博卡病毒VP2蛋白的原核表达及血清学检测方法的建立

目的获得高表达量的人博卡病毒（HBoV1、HBoV2）VP2蛋白,建立血清学检测方法。方法按照大肠埃希菌密码子使用偏性,对HBoV1、HBoV2VP2衣壳蛋白基因编码区序列进行优化合成。将合成的目的基因克隆至表达载体pET30a,构建重组表达质粒pET30a-VP2,转化大肠埃希菌BL21（DE3）,使用IPTG诱导表达并摸索最佳表达条件;粗提取蛋白进行Ni亲和层析纯化后建立间接酶联免疫吸附试验（ELISA）,进行临床血清标本筛查,分析人群HBoV1、HBoV2感染情况。结果优化合成的HBoV1、HBoV2VP2基因正确连接至pET30a载体,开放阅读框正确,用1mmol／LIPTG过夜诱导表达（25℃）得到高表达量的VP2蛋白,目的蛋白主要以包涵体的形式存在。粗提取蛋白经Ni—NTA亲和层析,在pH4．5时获得较理想的纯化蛋白,以其为抗原建立ELISA检查方法,筛查临床血清标本IgG抗体水平,结果显示健康儿童HBoV1阳性率为62．2％,HBoV2阳性率为55．5％,混合感染率为37％。结论本研究成功将H-BoV1、HBoV2VP2衣壳蛋白基因编码区序列进行优化,得到了较高的蛋白表达量,所建立的ELISA法可以应用于HBoV1、HBoV2人群血清流行病学调查。     

TP53 Arg72Pro polymorphism is associated with esophageal cancer risk: a meta-analysis

AIM:To investigate the association between TP53 Arg72Pro polymorphism and esophageal cancer(EC)risk using meta-analysis. METHODS:All eligible studies published before March 1,2010 were selected by searching PubMed using keywordsp53orTP53,polymorphismorvariation, esophagealandcancerorcarcinoma.Crude odds ratios(ORs)with 95%confidence intervals(CIs)were assessed for EC risk associated with TP53 Arg72Pro polymorphism using fixed-and random-effects models. RESULTS:Nine case-control studies involving 5545 subjec...     

Clinicopathologic characteristics of sporadic Japanese Creutzfeldt–Jakob disease classified according to prion protein gene polymorphism and prion protein type

We analyzed neuropathologic features of 23 Japanese patients with sporadic Creutzfeldt–Jakob disease (sCJD) by means of prion protein (PrP) immunolabeling associated with codon 129 polymorphism of the PrP gene and western blot analysis of protease-resistant PrP (PrP type). Clinical features, particularly age at onset, disease duration, periodic synchronous discharge and presence of myoclonus, were also analyzed. This study included 11 cases of subacute spongiform encephalopathy (SSE), 10 cases of panencephalopathic (PE)-type sCJD and two cases of thalamic-type sCJD, classified according to cerebral pathology findings. According to PrP gene polymorphism and PrP type, 18 cases were classified as MM1-type, two as MV1-type, two as MM2-type and one as MM1 + 2-type sCJD. SSE and PE-type sCJD showed similar clinical features, with the exception of disease duration, codon 129 polymorphism and PrP type. Thalamic-type sCJD showed different clinical features and PrP type. We suggest that SSE and PE-type sCJD comprise the sCJD subtype and that PE-type sCJD is a prolonged pathologic phenotype of SSE. When we compare our results with those from a series of Caucasian sCJD patients, the percentages of codon 129 polymorphisms differed, as did classification based on PrP gene polymorphism and PrP type; our series included many PE-type sCJD cases and disease duration was relatively long and MM2-type cases showed clinicopathologic variability.     

MicroRNA-129-2对人鼻咽癌CNE1细胞裸鼠移植瘤的抑制及其可能的机制

目的：探讨microRNA-129-2（miR-129-2）对人鼻咽癌CNE1细胞裸鼠移植瘤生长的抑制作用及其可能的机制。方法：建立人鼻咽癌CNE1细胞裸鼠皮下移植瘤模型,按皮下注射的药剂将32只模型小鼠用随机数字表法分为4组：对照组（皮下注射生理盐水0.2 ml/d）、空白质粒组\[(50 μg/只,0.2 ml/次,1次/d\]、顺铂（cisplatin,DDP）阳性对照组(1 mg/kg, 0.2 ml/次,1次/d）、miR-129-2组\[(50 μg/只,0.2 ml/次,1次/d\],共治疗5周,记录裸鼠体质量、肿瘤体积、肿瘤质量。流式细胞术检测各组移植瘤组织S+G2-M期细胞比例,免疫组化和Western blotting方法检测miR-129-2对移植瘤组织中转录因子SOX4表达的影响。结果：成功建立CNE1细胞裸鼠皮下移植瘤模型,治疗第22天起,miR-129-2组移植瘤的体积和质量均显著低于对照组和空白质粒组（P<0.01）,而与DDP组始终无明显差异（P>0.05）;5周后,miR-129-2组荷瘤小鼠的体质量显著高于其他3组（均P<001）。miR-129-2组移植瘤组织S+G2-M期细胞比例显著低于与对照组和空白质粒组（P<0.01）,与DDP组无显著差异（P>0.05）。移植瘤组织SOX4表达显著高于瘤旁组织, miR-129-2组和DDP组移植瘤组织内SOX4蛋白表达均较对照组显著降低（均P<0.01）,且miR-129-2组SOX4蛋白表达显著低于DDP组 （P<0.05）。结论： miR-129-2对人鼻咽癌CNE1细胞裸鼠皮下裸移植瘤的生长有明显的抑制作用,其机制可能与SOX4表达下调有关。     

Influence of the TP53 codon 72 polymorphism on the cellular responses to X-irradiation in fibroblasts from nonagenarians

In mice, genetic modification of the gene encoding p53 affects both cancer incidence and longevity. In humans, we recently found that a TP53 codon 72 Arginine (Arg) to Proline (Pro) polymorphism affected both cancer incidence and longevity as well. The TP53 codon 72 polymorphism has previously been shown to influence the apoptotic potential of human cells in response to oxidative stress. Here, we studied the influence of this polymorphism on the cellular responses to X-irradiation of fibroblasts obtained from nonagenarians. We found that the average clonogenic survival after X-irradiation was similar for the three TP53 codon 72 genotype groups. As described before, X-irradiation did not induce an appreciable degree of apoptosis in human fibroblasts. However, percentages of senescence-associated (SA)-β-galactosidase positive cells (p < 0.001), micronucleated cells (p < 0.001) and cells displaying abnormal nuclear morphologies (p < 0.001) significantly increased with the radiation dose. Compared to Arg/Arg fibroblasts, Pro/Pro fibroblasts exhibited higher irradiation dose-dependent increases in SA-β-galactosidase positive cells (p_interaction = 0.018), micronucleated cells (p_interaction = 0.005) and cells displaying abnormal nuclear morphologies (p_interaction = 0.029) at 3 days after irradiation. Possibly, these differences in cellular responses to stress between the TP53 codon 72 genotypes contribute to the differences in cancer incidence and longevity observed earlier for these genotypes.     

Partial change in EphA4 knockout mouse phenotype: Loss of diminished GFAP upregulation following spinal cord injury

In a previous study we found that the EphA4 receptor inhibits regeneration following spinal cord injury by blocking regrowth of axons and regulation of astrocyte reactivity. In our original studies using EphA4 null mice [Goldshmit et al., J. Neurosci., 2004] we found attenuated astrocyte reactivity following spinal cord injury. Several other studies have now supported the role of EphA4 in regulating neural regeneration but a recent study [Herrmann et al., Exp. Neurol., 2010] did not find an effect of EphA4 on astrocyte reactivity. Re-examination of astrocytic gliosis following injury in our current cohort of EphA4 null mice revealed that they no longer showed attenuation of astrocyte reactivity, however other EphA4 null mouse phenotypes, such as decreased size of the dorsal funiculus were unaltered. We hypothesised that long-term breeding on the C57Bl/6 background may influence the EphA4-mediated astrocyte phenotype and compared astrocytic gliosis at 4 days following spinal cord injury in wildtype and EphA4 null mice on the C57Bl/6 background and backcrossed C57Bl/6×129Sv(F2) mice, as well as wildtype 129Sv mice. 129Sv mice had increased GFAP expression and increased numbers of reactive GFAP astrocytes compared to C57Bl/6 mice. There was no significant effect of EphA4 deletion on GFAP expression in C57Bl/6 mice or the F2 crosses other than a moderately decreased number of EphA4 null astrocytes in C57Bl/6 mice using one of two antibodies. Therefore, there has been an apparent change in EphA4-mediated astroglial phenotype associated with long term breeding of the EphA4 colony but it does not appear to be influenced by background mouse strain.