Hepatitis B virus genotype C prevails among chronic carriers of the virus in Korea

Hepatitis B virus (HBV) is one of the major causative agents of chronic liver diseases in Korea. HBV has been classified into 8 genotypes by a divergence of >8% in the entire genomic sequence, and have distinct geographic distributions. There are limited data on the relevance between HBV genotypes and clinical outcomes in Korea. To investigate the clinical feature relating to HBV genotype in Korea, a total 120 serum samples with HBsAg (65 from Seoul and 55 from the other city in Korea) were obtained from each 30 chronic HBV carriers with asymptomatic carrier (ASC), chronic hepatitis (CH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). HBV genotype was determined by either enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies against genotype-specific epitopes in the preS2-region or the direct sequencing of small S gene. HBV genotypes were determined in 105 (87.5%) of 120 samples. HBV genotype C was identified in all HBV carriers with ASC, CH, LC, and HCC. Genotypes A, B, D, E, F and G were not detected in any of them. Genotype C HBV prevails predominantly among chronic carriers of the virus in Korea, irrespective of their clinical stages of liver disease and geographic origin.     

Cbl-b differentially regulates activation-induced apoptosis in T helper 1 and T helper 2 cells

We previously reported that ligation of CD3 induces antiapoptotic signals in T helper 2 (Th2) cells, and in contrast causes Th1 cells to undergo apoptosis. Here we show that Cbl-b is accountable for the unequal response, revealing a previously unknown cell-specific regulatory function for the molecule. Absence of Cbl-b resulted in resistance to activation-induced apoptosis in murine Th1 cells following CD3 ligation, akin to what is observed in Th2 cells containing Cbl-b. Concurrent with the apoptosis profile, CD3 ligation in the absence of Cbl-b induced raft mobilization and cytoskeletal rearrangement in Th1 cells. Despite their ability to signal from CD3, Th2 cells did not aggregate their rafts, providing an explanation for cell-specific activity of Cbl-b.     

The effect of passive smoking on asthma symptoms,atopy,and airway hyperresponsiveness in schoolchildren

Passive smoking is a major cause of respiratory morbidity, and is associated with increased bronchial responsiveness in children. To evaluate the effect of smoking by a parent on asthma symptoms, atopy, and airway hyperresponsiveness (AHR), we conducted a cross-sectional survey of 503 schoolchildren that involved questionnaires, spirometry, allergy testing, and a bronchial challenge test. If the PC20 methacholine was less than 16 mg/mL, the subject was considered to have AHR. The prevalence of a parent who smoked was 68.7%. The prevalence of AHR was 45.0%. The sensitization rate to common inhalant allergens was 32.6%. Nasal symptoms such as rhinorrhea, sneezing, nasal itching, and nasal obstruction were present in 42.7%. Asthma symptoms such as cough and wheezing were present in 55.4%. The asthma symptoms were significantly more prevalent in children who had a parent who smoked than in those whose parents did not. The nasal symptoms, atopy, and AHR did not differ according to whether a parent smoked. In a multiple logistic regression model, the asthma symptoms and atopy were independently associated with AHR, when adjusted for confounding variables. Passive smoking contributed to asthma symptoms in schoolchildren and was not an independent risk factor of airway hyperresponsiveness in an epidemiological survey.     

Additive effect of TRAIL and p53 gene transfer on apoptosis of human lung cancer cell lines

TRAIL is a cytokine that can induce tumor-specific apoptosis through its specific death receptors (DR4 and DR5) and p53 has been proven to increase the expression of death receptors. To examine their interaction in tumor suppression, p53 and TRAIL genes were inserted in recombinant adenovirus vectors and transferred simultaneously into non-small cell lung cancer cell lines (NCI-H157, NCI-H358, NCI-H460 and A549). Western blot assay demonstrated production of TRAIL protein in NCI-H157 and A549 cell lines. Increased expressions of DR4 and DR5 of NCI-H157 and DR4 of A549 after p53 overexpression were confirmed by flow cytometry. p53 or TRAIL gene transfer increased sub-G1 fraction in cell cycle analysis and inhibited the tumor growth dose-dependently and the degree was potentiated by co-transfer. But isobologram analysis indicated an additive effect. Together, these data indicate that p53 and TRAIL interact additively on tumor apoptosis despite theoretical synergism.     

耐热可溶性戊型肝炎病毒基因工程抗原的表达

目的 利用硫氧还蛋白融合表达系统表达戊型肝炎病毒（Hepatitis E virus,HEV)结构基因片段，获得耐热，可溶、具有生物活性的HEV基因工程抗原。方法 将HEVORF26964-7126nt基因片段插入硫氧还蛋白融合表达载体pThioHisA，转化大肠埃希菌BL21，经IPTG诱导，表达融合蛋白。裂解细菌后，离心，取上清置于80℃处理10min，再次离心，取上清用ELISA方法测定表达产物的生物活性。结果 SDS-PAGE分析表明，HEV结构基因获得高效表达，相对分子质量约为20000，耐热，水溶性好，ELISA证实具有HEV特异抗原性。结论 应用硫氧还蛋白融合表达系统成功表达了耐热，可溶，具有生物活性的HEV基因工程抗原。     

Identification of the products of the equine herpesvirus type 4 gI and gE genes

Summary.  In order to identify the products of the equine herpesvirus type 4 (EHV-4) gI and gE genes, we have constructed recombinant vaccinia viruses containing the putative gI or gE genes. These recombinant viruses synthesized EHV-4 gI and gE with apparent molecular masses of 75 and 80 kDa, respectively. Antibodies raised against both recombinant viruses detected a 75 kDa gI and a 95 kDa gE in EHV-4-infected cells. The results also suggest that the EHV-4 gI and gE would form a complex like in other herpesviruses. Received October 29, 1999 Accepted January 21, 2000     

CD40靶向小干扰RNA抑制大鼠异体肢体移植急性排斥反应后细胞凋亡及P53、P21表达

目的探讨CD40靶向小干扰RNA（即短发夹RNA，shRNA）对大鼠异体肢体移植急性排斥反应及细胞凋亡的影响。方法以纯系SD大鼠为供体，纯系Wistar大鼠为受体，行同种异体右后肢移植。27只大鼠肢体移植后随机分为3组：实验组．注射梭华一Sofast（15μl）-siCD40—2，pSilencer（100μg）载体复合物600μl；空载体对照组，在肢体移植后，即注射Sofast（15μl）-pSilencer4．1-CMVneo（100μg）空载体复合物600μl；生理盐水对照组，在肢体移植注射生理盐水600μl。观察移植物排斥反应征象及存活情况，并于第7天对产生免疫耐受大鼠进行混合淋巴细胞反应（MLR），同时进行组织学检查。结果与其他组相比．实验组移植物发生排斥反应的时间及存活时间均显著延长（P〈0．01）（〉13d），未见排斥反应征象，其他组均于术后近期发生排斥反应；实验组大鼠对供体的淋巴细胞呈现低反应性，移植的供体同系大鼠的肢体得以存活。实验组移植物细胞凋亡率低于其他组。结论在术后不应用免疫抑制剂的情况下，CD40靶向的shRNA干扰可以抗大鼠异体肢体移植急性排斥反应。     

Assessment of cyclooxygenase inhibitors using in vitro assay systems

Various inhibitors of cyclooxygenase are known to mediate cancer chemopreventive effects. We currently describe two in vitro assay systems for measuring cyclooxygenase activity. These assays can be used in combination and thereby provide a rapid, reliable, and economical approach that is applicable for large-scale evaluation of test samples. This approach employs peroxidase co-substrate oxidation and oxygen consumption assays. The former system, adapted to a 96-well plate format, detects inhibitors that function as a radical scavengers or interact with the enzyme directly. The latter system specifically monitors cyclooxygenase inhibitors that interact with the enzyme itself. Thus, the peroxidase co-substrate oxidation assay serves as a pre-screening method, whereas the oxygen consumption assay is used subsequently to investigate the mode of action mediated by samples which test positive.