Effects of vitamin A on proliferation of human distal airway epithelial cells in culture

Using a serum-free culture method, we investigated the effects of vitamin A on the proliferation of human distal airway epithelial cells. Outgrowth of epithelial cells from lung tissue explants was enhanced by treatment with all-trans retinol at concentrations of 10^–8 to 10^–7 M. The colony-forming activity of cells harvested from the primary culture and replated onto Swiss 3T3 fibroblastic feeders was, in contrast, significantly reduced by 10^–7 M to 10^–5 M retinol. When the primary cells were harvested and subcultured on Primaria plates, population expansion was also inhibited by retinol at 10^–10 to 10^–6 M. We further investigated the cells to determine whether there was any difference in sensitivity to the growth-inhibitory effects of vitamin A between cells from the primary culture incubated with and without retinol. The population increase in cells harvested from the primary culture was inhibited equally in retinol-treated and non-treated cells by subsequent treatment with retinol or retinoic acid, this inhibition being dose-dependent. DNA synthetic activity was also inhibited. Interestingly, both the growth rate and the colony-forming efficiency on feeders were greater in the subculture of cells from the retinol-treated primary culture than in those non-treated. When the cells in the secondary subculture were treated with retinoic acid and replated again, they showed a greater population increase rate than those non-treated. Our results showed that human distal airway epithelial cells isolated from lung tissue were sensitive to the growth-inhibitory effect of vitamin A, but the proliferative potential in some fraction of the epithelial cell population was possibly enhanced by vitamin A treatment.     

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。     

Safety of anti-immunoglobulin E therapy with omalizumab in allergic patients at risk of geohelminth infection

BACKGROUND: Although the role of immunoglobulin E (IgE) in immunity against helminth parasites is unclear, there is concern that therapeutic antibodies that neutralize IgE (anti-IgE) may be unsafe in subjects at risk of helminth infection. OBJECTIVE: We conducted an exploratory study to investigate the safety of omalizumab (anti-IgE) in subjects with allergic asthma and/or perennial allergic rhinitis at high risk of intestinal helminth infection. The primary safety outcome was risk of infections with intestinal helminths during anti-IgE therapy. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in 137 subjects (12-30 years) at high risk of geohelminth infection. All subjects received pre-study anthelmintic treatment, followed by 52 weeks' treatment with omalizumab or placebo. RESULTS: Of the omalizumab subjects 50% (34/68) experienced at least one intestinal geohelminth infection compared with 41% (28/69) of placebo subjects [odds ratio (OR) 1.47, 95% confidence interval (CI) 0.74-2.95, one-sided P=0.14; OR (adjusted for study visit, baseline infection status, gender and age) 2.2 (0.94-5.15); one-sided P=0.035], providing some evidence for a potential increased incidence of geohelminth infection in subjects receiving omalizumab. Omalizumab therapy was well tolerated, and did not appear to be associated with increased morbidity attributable to intestinal helminths as assessed by clinical and laboratory adverse events, maximal helminth infection intensities and additional anthelmintic requirements. Time to first infection (OR 1.30, 95% CI 0.79-2.15, one-sided P=0.15) was similar between treatment groups. Infection severity and response to anthelmintics appeared to be unaffected by omalizumab therapy. CONCLUSIONS: In this exploratory study of allergic subjects at high risk of helminth infections, omalizumab therapy appeared to be safe and well tolerated, but may be associated with a modest increase in the incidence of geohelminth infection.     

人乳头状瘤病毒16 E7 DNA在结直肠腺癌组织中的表达

结直肠癌与人类乳头状瘤病毒(Human papilloma virus,HPV)感染有一定的关系,但由于检测方法、标本选择及样本数量不同,各研究结果之间差异很大。为进一步明确结直肠癌变与HPV16感染的关系,采用多聚酶链反应(Polymerase chain reaction,PCR)对82例原发性结直肠腺癌患者手术切除的新鲜癌及癌旁正常粘膜组织进行了前瞻性对照研究,检测了组织中HPV16E7DNA的表达并进行测序鉴定。结果显示,结直肠腺癌组织HPV16E7的表达阳性率(42/82)明显高于癌旁正常粘膜组织(4/82);直肠癌组织中HPV16E7的表达(64.10%)明显高于升结肠癌(18.18%),即癌灶部位距肛门越近,感染率越高;HPV16阳性率与Dukes分期相关,Dukes分期越晚感染率越高;与癌组织分化程度无相关性。结果提示结直肠癌的发生、发展可能与HPV16感染有关。     

Lipid peroxidation and antioxidant status in human cervical carcinoma

Reactive oxygen species (ROS), represented by superoxide, hydrogen peroxide and hydroxyl radicals, have been implicated in many diseases including cancer. ROS have been known to play an important role in the initiation and promotion of multistep carcinogenesis. The cellular antioxidants play a crucial role in protection against neoplastic disease. However, very little is known about the antioxidant defense in cervical carcinoma. This is addressed in the present study. Lipid peroxides, glutathione content and the activities of antioxidant enzymes, together with vitamin C and E content, were estimated in patients who had carcinoma of the cervix, and the values were compared with those of normal women. The results showed a remarkable reduction in the content of glutathione, vitamin E and C. Activities of glutathione peroxidase and superoxide dismutase were also reduced in cervical cancer compared to normal controls (P < 0.001). This reduction was more marked in late stages (III, IV) than in early stages (I, II) (P < 0.001). Glutathione was reduced more in poorly differentiated tumors (grade III) than in well and moderately differentiated ones (grade I, II) (P < 0.05). Levels of lipid peroxides were found to be significantly higher in malignant than in normal tissue samples and their levels were correlated with advanced clinical stage (P < 0.001). Our results suggest impaired antioxidant status in carcinoma of the cervix. This impairment is related to tumor progression.     

载脂蛋白E不同基因型胆囊结石患者的血脂水平分析

为了解载脂蛋白Ｅ不同基因型胆囊结石患者的血脂水平，应用ＰＣＲ技术研究了８７例胆囊结石患者和５０例正常人的ＡｐｏＥ基因型，另测定参加者空腹血脂。结果发现：Ｅ２／３基因型的胆囊结石患者血清ＴＧ、ＶＬＤＬ－Ｃ水平显著升高，ＬＤＬ－Ｃ水平显著降低。Ｅ３／３基因型胆囊结石患者ＨＤＬ－Ｃ、ＨＤＬ２－Ｃ、ＨＤＬ３－Ｃ水平显著下降。Ｅ３／４基因型胆囊结石患者ＶＬＤＬ－Ｃ轻度降低，ＬＤＬ－Ｃ轻度升高。结果提示：同一ＡｐｏＥ基因型胆囊结石患者血脂异常较正常人突出，不同基因型的胆囊结石患者血脂异常的特征各不相同。为研究胆囊结石病发病机理提供了资料。     

Reproducibility of leukotriene D4 inhalation challenge in asthmatics

We have studied the reproducibility of a bronchial leukotriene (LT) provocation test in asthmatics, and the effect of prior treatment with an oral leukotriene D4/E4 antagonist (SR 2640) on LTD4-induced bronchoconstriction in nine asthmatics in a double-blind placebo-controlled randomized cross-over trial. The reproducibility of the bronchial leukotriene provocation test was high. For a specific patient, the replication variance is 0.2303, and the standard deviation is thus 0.4799, corresponding to 48%, i.e. one halving of the dose or half doubling of the dose. SR 2640 antagonised LTD4 induced bronchoconstriction causing a mean shift of 48% to the right of the dose-response curve as compared with placebo (95% confidence interval being 11-137%). This study demonstrates that bronchial LTD4 provocation test is a safe and reproducible method in asthmatics, and that the method can be used to detect LT-antagonism; furthermore that SR 2640 is a weak LTD4-antagonist in asthmatics.     

Induction of Ly-6A/E expression by murine lymphocytes after in vivo immunization is strictly dependent upon the action of IFN-alpha/beta and/or IFN-gamma

Ly-6A/E is a phosphatidylinositol-linked membrane protein which mediates murine T and B cell signalling. IFN-gamma, IFB-alpha/beta, LPS, and IL-4 have all been reported to induce or upregulate Ly-6A/E by normal lymphocytes. Since no systematic study has addressed the stimulant selectivity of Ly-6A/E expression by murine lymphocytes nor investigated its induction and regulation during primary in vivo immune responses we analyzed in vitro Ly-6A/E expression after murine stimuli and during a number of distinct in vivo immunizations. We show that LPS induces B cell Ly-6A/E in vitro by stimulating the release of IFN-alpha/beta by 'contaminating' adherent cells. In the presence of anti-IFN-gamma + anti-IFN-alpha/beta antibodies, no Ly-6A/E was induced upon addition of multiple cytokines, including IL-4, or mitogenic doses of anti-Ig antibody. Furthermore, IFN-gamma-containing, CD4+ T cell (Th1) supernatants potently induced Ly-6A/E by murine B cells whereas IL-4-containing (Th2) supernatants were either weak or ineffective; anti-IFN-gamma + anti-IFN-alpha/beta inhibited Ly-6A/E induction by both Th1 and Th2 supernatants. Immunization of mice with Brucella abortus or poly (I).poly (C) resulted in induction of Ly-6A/E expression by virtually all B and T cells, whereas injection of G alpha M delta led to peak induction of Ly-6A/E by approximately 50% of both B and T cells. Lymphocytes from mice infected with the nematode parasites Nippostrongylus brasiliensis or Heligmosomoides polygyrus expressed no Ly-6A/E.(ABSTRACT TRUNCATED AT 250 WORDS)     

糖皮质激素对前列腺素E2介导的主动脉平滑肌细胞cAMP生成的影响

目的观察地塞米松对前列腺素Ｅ２介导的离体培养兔主动脉平滑肌细胞的ｃＡＭＰ生成的影响。方法用蛋白竞争结合法测定细胞ｃＡＭＰ含量,并确定腺苷酸环化酶的活性。结果从１０ｐｍｏｌ／Ｌ到１０ｎｍｏｌ／Ｌ地塞米松对培养细胞的ｃＡＭＰ生成有明显抑制作用并呈现剂量依赖性,作用时间愈长,该抑制作用愈强。经地塞米松预处理８小时的培养细胞,其前列腺素Ｅ２介导的腺苷酸环化酶活性显著下降。结论糖皮质激素在腺苷酸环化酶水平抑制前列腺素Ｅ２介导的培养平滑肌细胞ｃＡＭＰ生成。另外还观察到地塞米松拮抗前列腺素Ｅ２的抑制培养细胞增生效应,但未发现地塞米松对培养平滑肌细胞增生的直接促进作用