BmK AS: new scorpion neurotoxin binds to distinct receptor sites of mammal and insect voltage-gated sodium channels

This study was undertaken to assess the binding properties of BmK AS on both mammal and insect excitable cell membranes. It was found that BmK AS bound specifically to a single class of non-interacting binding sites on both rat brain and cockroach nerve cord synaptosomes with high affinity (K(d) = 1.49 +/- 0.14 and 0.79 +/- 0.29 nM) and low capacity (B(max) = 1.39 +/- 0.09 and 6.60 +/- 1.25 pmol/mg protein), respectively. Binding kinetics showed that BmK AS could bind and reach equilibrium quickly, and dissociate partially from its binding sites on both kinds of synaptosomes. The binding of BmK AS was independent of membrane potential. Veratridine could not modify the binding of BmK AS. The competitive binding assay showed that specific binding of (125)I-BmK AS could be significantly inhibited by native BmK AS, BmK AS-1, BmK IT2 and BmK IT on both synaptosomes. Unexpectedly, only about 20-30% binding of BmK AS on mammal synaptosomes was inhibited by BmK I at 10(-5)-10(-9) M, but not on insect synaptosomes. It thus suggests that BmK AS type neurotoxins might bind to a distinct receptor site of sodium channels on mammal and insect excitable cell membranes with a manner similar to beta-scorpion toxins.     

Anti-inflammatory effect of Diammonium Glycyrrhizinate in a rat model of ulcerative colitis

AIM: To explore the anti-inflammatory mechanism of Diammonium Glycyrrhizinate in a rat model of ulcerative colitis induced by acetic acid. METHODS: Spragur-Dawley female rats were divided into four groups: Diammonium Glycyrrhizinate group, dexamethasone group, acetic acid control and normal control group. Colonic inflammation was evaluated by disease activity index, gross morphologic damage, histological injury and colonic myeloperoxidase activity. Immunohistochemistry was used to detect the expression of NF-κB, TNF-αand ICAM-1 in colonic mucosa. RESULTS: Compared to the acetic acid control, both Diammonium Glycyrrhizinate and dexamethasone showed a significant anti-inflammatory effect (P < 0.01). The expression of NF-κB, TNF-a and ICAM-1 in colonic mucosa was significantly lower in the Diammonium Glycyrrhizinate group and dexamethasone group than in the acetic acid group. CONCLUSION: Diammonium Glycyrrhizinate could reduce inflammatory injury in a rat model of ulcerative colitis. This may occur via suppression of NF-κB, TNF-a and ICAM-1 in colonic mucosa.     

不耐受标准治疗方案慢性丙型肝炎患者的低剂量干扰素治疗

目的 针对不能耐受标准治疗方案的慢性丙型肝炎(CHC)患者,探索低剂量干扰素联合利巴韦林长期维持治疗的效果,并分析与疗效相关的可能影响因素. 方法 对于白细胞低下、甲状腺功能异常等多种原因不能耐受标准治疗方案的CHC患者46例,给予个体化低剂量干扰素(标准干扰素60万～300万IU隔日一次,聚乙二醇干扰素50 ～ 90μg/周)联合利巴韦林0.6 ～ 0.9 g/d 长期维持治疗,疗程≥72周.连续变量两组间比较采用t检验或秩和检验,计数资料采用x2检验或Fisher’s exact test检验.结果 93.5％患者(43/46)可耐受不同低剂量干扰素联合利巴韦林长期维持治疗,只有3例不能耐受而被迫停药.不同节点的病毒学应答率为:快速病毒学应答10.9％、早期病毒学应答 30.4％、24周病毒学应答45.7％、48周病毒学应答47.8％.3例患者在治疗过程中肝脏B型超声显示形态学改善.快速病毒学应答、早期病毒学应答、24周病毒学应答者均可在48周时获得较高病毒学应答,尤其24周病毒学应答对48周病毒学应答具有较好预测作用,获得24周病毒学应答者其48周病毒学应答率为95.2％,而24周未获得病毒学应答者其48周未应答率为92.0％.结论 (1)对于不能耐受标准治疗方案的CHC患者予以低剂量干扰素联合利巴韦林长期维持治疗,可以获得较高的48周病毒学应答率(47.8％);(2)24周病毒学应答对48周病毒学应答具有较好预测作用;(3)疗程中严密监测、对症治疗原发病并给予患者足够的依从性教育和心理疏导是治疗得以维持的重要保证.     

Detection of human chromosomal abnormalities using a new technique combining 4',6-diamidino-2-phenyl-indole staining and image analysis

Chromosomal abnormalities are associated with a variety of diseases. We have developed a new technique for detecting chromosomal abnormalities, and the technique combines conventional 4',6-diamidino-2-phenyl-indole staining (DAPI) with image analysis. The image analysis consists of two simple steps: deconvolution and three-dimensional reconstruction. The technique has been reported for analyzing plant chromosomes but has not been applied to analyze human chromosomes yet. To test the technique, we analyzed five translocations: 46,XX,t(3;21)(12;18), 46,XX,t(11;22), 46,XY,t(7;22), 46,XY,t(11;18), and 46,XY,t(3;7). The results showed that the karyotype of the 46,XX,t(3;21)(12;18) was 46,XX,t(3;21)(q11.1;p13),t(12;18) (q21.2;q23), and the karyotypes of the 46,XX,t(11;22), 46,XY,t(7;22), 46,XY,t(11;18), and 46,XY,t(3;7) were 46,XX,t(11;22)(q23;q12.1); 46,XY,t(7;22)(q32;q13.2); 46,XY,t(11;18)(q13.3;q23), and 46,XY,t(3;7)(q22.1;p13), respectively. The identity of derivative chromosomes involved in the translocations was verified by chromosome painting as well as FISH analyses with centromere probes. The new technique has two advantages: the procedure is simple and convenient, and the results are accurate. The technique has the potential to be used in cytogenetic studies and clinical diagnosis of human diseases in the future.     

Dual expression of the HA protein of H5N2 avian influenza virus in a baculovirus system

Baculovirus/insect cell system is used widely for recombinant protein production. The hemagglutinin (HA) gene of H5N2 avian influenza virus (AIV) 1209 strain and the enhanced green fluorescent protein (EGFP) gene were cloned into pFastBac DUAL vector that has two promoters and cloning sites, allowing simultaneous expression of these two genes. The HA protein of AIV was fused with a hexahistidine (His6) tag for purification. The coexpression of EGFP allowed identification of the recombinant baculoviruses in Sf-9 insect cells, eliminating cumbersome and time-consuming assays. A recombinant baculovirus, Bac-HA, was generated by transfecting pBac-HA to bacmid inside DH10B(AC)Escherichia coli by site-specific transposition, followed by transfection into the Sf-9 cells. Fluorescence in the insect cells was observed from 3 days post-infection. The expressed HA protein was confirmed by Western blot using an anti-HA monoclonal antibody. Also, different detergents and incubation times on ice were tested. The two-stage extraction with Triton X-100 or Tween 20 and incubation on ice for 2h exhibited high efficiency. Since purification of HA with ConA resin resulted in low protein recovery, lentil lectin affinity column was used and was useful for HA purification.     

套细胞淋巴瘤的临床病理特征及预后因素分析

目的探讨套细胞淋巴瘤（MCL）的临床病理特征及预后因素。方法对102例经形态学及免疫表型检测确定的MCL进行分析,组织病理制片和链霉素抗生物素蛋白过氧化物酶法或EnVision法染色,并进行了随访。结果102例患者中位年龄59岁（30～79岁）,男女之比约2．92：1。淋巴结是最常受累的部位（98／98,100％）,结外常受累的部位：骨髓（29／45,64．4％）、脾脏（36／57,63．2％）、咽淋巴环（15／48,31．3％）、外周血（15／51,29．4％）、肝脏（12／53,22．6％）及胃肠道（15／102,14．7％）;87．7％（71／81）初次就诊时处于临床Ⅲ～Ⅳ期,45．5％（25／55）患者有B症状;48．7％（19／39）患者血清乳酸脱氢酶升高。除7例（6．9％）因组织取材小无法区分病变模式外,余95例中12例（11．76％）为套区增生型,41例（40．2％）结节型,42例（41．2％）弥漫型。75．5％（77）经典型,24．5％（25例）瘤细胞呈母细胞样变型。102例均表达B细胞标记而不表达T细胞标记,96例（94．1％）肿瘤细胞表达细胞周期蛋白D1,70例（71．4％）CD5弱阳性。68例获得随访,中位生存时间10个月（0～89个月）。套区增生型＋结节型、经典型的核分裂象≤15／10HPF,增殖指数≤15％;骨髓无受累,提示患者预后好,而其他临床病理因素对患者生存未见影响。结论国内MCL患者病征与国外患者基本一致,其病变模式、细胞变型、核分裂象、增殖指数、骨髓是否受累及受累程度与预后有关。     

Rosai-Dorfman病的临床病理、免疫表型和病原学观察

目的观察Rosai—Doffman病的临床病理特征,探讨多种抗原标记的免疫表型及HHV8-DNA、HPV—DNA和EBER的表达及其与病因的关系,并比较国内外Rosm—Doffman病的发病特征。方法对16例Rosm-Doffman病进行临床病理回顾性研究;9例行免疫表型检测,包括CD163、CD68（PG—M1）、CD21、CD1a、CD20、CIMSRO、CD8、CIM、S100、M—CSF和HHV8;用原位杂交技术进行EBV—mRNA和HPV—DNA检测。结果（1）男女之比为4．33：1。只有淋巴结病变的占62．5％（10／16）,颈淋巴结多见,50％的病例有多部位淋巴结累及;结外病变占37．5％（6／16）。结外病变者的局部复发率较高。（2）淋巴结病变以明显扩张的淋巴窦内有不等量体积大、多角形、胞质内含有淋巴细胞和浆细胞的组织细胞为特征;结外病变均有不同程度纤维组织增生和以浆细胞为主的混合炎细胞浸润,胞质内含有淋巴细胞和浆细胞的大多角形组织细胞数量多寡不一,呈簇状或散在分布,且随病程进展,纤维组织的量渐多,特征性组织细胞数量渐少。（3）病变组织中大多角形组织细胞均表达S—100蛋白,以及CD68PG—M1、CD163和M—CSF,均不表达CD1a和CD21;组织细胞吞入的有T和B细胞,以T细胞为多,且CIM和CD8表型细胞均有。9例均为HHV8和EBEV阴性。（4）国内报道共62例,其中仅淋巴结病变34例,仅结外病变18例,淋巴结和结外同时存在病变10例。比较国内外文献,国外患者年龄较国内的年轻10岁以上,且女性比例较高。结论Rosai—Dofman病在国内较少。结外Rosai—Dorfman病的诊断有一定难度。HHV8-DNA、HPV—DNA和EBER的表达与病因关联不明确。国内外患者的发病年龄和性别构成不同。     

Study on the haplotypes of MICA and MICB microsatellite and HLA-B locus in the Guangzhou Han population

The purpose of this study was to investigate the genetic polymorphisms and haplotypes of microsatellite locus in exon 5 of the MICA gene and intron 1 of the MICB gene and human leukocyte antigen-B (HLA-B) gene based on 106 samples of the Guangzhou Han population through means of polymerase chain reaction and the fluorescent technique (6-FAM). The corresponding haplotype frequencies, linkage disequilibrium values and relative linkage disequilibrium values were estimated based on population data. The results show that the genotype distributions of MICA and MICB microsatellite and HLA-B satisfy the Hardy-Weinberg equilibrium. In total, five alleles of MICA microsatellite locus and 14 alleles of MICB microsatellite locus were observed. MICA A5 was the most common allele (0.2877), whereas A4 was the least common (0.1321). MICB CA14 was the most common allele (0.3255), and CA19 and CA28 were the two least common (0.0047). CA27 was not observed at all. Five kinds of MICA-MICB haplotypes, 18 kinds of MICA-HLA-B haplotypes and 12 kinds of MICB-HLA-B haplotypes occurred at frequencies of more than 1%. The common haplotypes of MICA-MICB, MICA-HLA-B and MICB-HLA-B were A5-CA14, A5.1-CA18, A4-CA26, A9-CA15, A5-B*15(62), A5.1-B*1301/1302, A4-B*1301/1302, A6-B*51, A6-B*4403, A9-B*3802, CA14-B*4601, CA18-B*1301/1302 and CA26-B*1301/1302, and these haplotypes showed strong linkage disequilibrium. The polymorphisms and haplotype distributions of MICA and MICB microsatellite and HLA-B locus in the Guangzhou Han population have their own distinct genetic characteristics. The microsatellite locus of exon 5 of the MICA gene and intron 1 of the MICB gene could therefore be used as genetic markers in the studies of anthropology, gene linkage analysis in genetic diseases, individual identification and paternity testing in forensic medicine.     

Inverse correlation between gastroesophageal reflux disease and atrophic gastritis assessed by endoscopy and serology

BACKGROUND Helicobacter pylori(H.pylori)infection is known to prevent the occurrence of gastroesophageal reflux disease(GERD)by inducing gastric mucosal atrophy.However,little is known about the relationship between atrophic gastritis(AG)and GERD.AIM To confirm the inverse correlation between AG and the occurrence and severity of GERD.METHODS Individuals receiving health checkups who underwent upper gastrointestinal endoscopy at Seoul National University Healthcare System Gangnam Center were included.The grade of reflux esophagitis was evaluated according to the Los Angeles classification.Endoscopic AG(EAG)was categorized into six grades.Serologic AG(SAG)was defined as pepsinogen I≤70 ng/m L and pepsinogen I/II ratio≤3.0.The association between the extent of EAG and SAG and the occurrence and severity of GERD was evaluated using multivariate logistic regression analysis.RESULTS In total,4684 individuals with GERD were compared with 21901 healthy controls.In multivariate logistic regression analysis,advanced age,male sex,body mass index>23 kg/m2,presence of metabolic syndrome,current smoking,and alcohol consumption were associated with an increased risk of GERD.Seropositivity for H.pylori immunoglobulin G antibodies was associated with a decreased risk of GERD.There was an inverse correlation between the extent of EAG and occurrence of GERD:Odds ratio(OR),1.01[95%confidence interval(CI):0.90-1.14]in C1,0.87(0.78-0.97)in C2,0.71(0.62-0.80)in C3,0.52(0.44-0.61)in O1,0.37(0.29-0.48)in O2,and 0.28(0.18-0.43)in O3.Additionally,the extent of EAG showed an inverse correlation with the severity of GERD.The presence of SAG was correlated with a reduced risk of GERD(OR=0.49,95%CI:0.28-0.87,P=0.014).CONCLUSION The extent of EAG and SAG exhibited strong inverse relationships with the occurrence and severity of GERD.AG followed by H.pylori infection may be independently protect against GERD.     

Phosphatidylinositol 3-kinase-C2β inhibits cisplatin-mediated apoptosis via the Akt pathway in oesophageal squamous cell carcinoma

A major problem in treating oesophageal squamous cell carcinoma (ESCC) with cisplatin is the development of drug resistance. In order to determine whether phosphatidylinositol 3-kinase (PI3K)-C2β (encoded by the PIK3C2B gene) reduced the sensitivity of ESCC to cisplatin, transfected Eca109 cells that overexpressed PIK3C2B were produced. Additionally, PI3K-C2β-siRNA was used to silence endogenous PI3K-C2β in EC9706 cisplatin-resistant cells. The relationship between PIK3C2B expression and clinicopathological characteristics was also investigated in samples from 61 patients. The overexpression of PIK3C2B in Eca109 cells significantly inhibited cisplatin-induced apoptosis and cleavage of caspase-3. Knockdown of PI3K-C2β enhanced cisplatin-induced apoptosis in EC9706 cells. PIK3C2B expression was associated with an increased level of phosphorylated Akt. Based on the tumour samples, expression of PIK3C2B was associated with tumour metastasis and in vitro assay suggested that it mediated cell migration. These results indicated that PI3K-C2β, via the Akt signalling pathway, might play a key role in cisplatin resistance and that targeting this pathway might be useful in treating cisplatin-resistant tumours.