Identification of Vibrio alginolyticus virulent strain-specific DNA regions by suppression subtractive hybridization and PCR.

AIMS: Vibrio alginolyticus was frequently isolated from diseased farmed fish in the coaster waters of Hainan Island over the past two decades. In this study, we attempted to identify candidates of virulent strain-specific DNA regions for this pathogen. METHODS AND RESULTS: Suppression subtractive hybridization (SSH) and PCR were successively performed between the typical virulent strain and avirulent strain of V. alginolyticus, in which they shared 99·54% homology of 16S rDNAs. Out of 2873 subtracted clones, nine clones were finally indicated to harbour virulent strain-specific DNA fragments. The receivable functions of the major fragments in the nine clones were believed to encode methyl-accepting chemotaxis protein (n = 1), type VI secretion system-associated FHA domain protein TagH (n = 1), diguanylate cyclase (n = 1), AraC family transcriptional regulator (n = 1), ABC-type uncharacterized transport system permease component (n = 1) and hypothetical proteins (n = 4). Two hypothetical proteins contain several disordered regions. CONCLUSIONS: Some specific DNA regions existed in the virulent strain of V. alginolyticus, and the SSH assay could be a highly sensitive method for identifying virulent regions in pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: This report is the first to describe the identification of virulent strain-specific DNA regions in the V. alginolyticus genome, which is helpful in developing virulent strain-specific rapid detection methods and is a pivotal precondition for clarifying the molecular virulence mechanism of V. alginolyticus.

Low expression of integrin signaling pathway genes is associated with abdominal aortic aneurysm: a bioinformatic analysis by WGCNA.

OBJECTIVE: An abdominal aortic aneurysm (AAA) is a potentially fatal disease associated with a high risk of rupture. AAA is pathologically distinguished by atherosclerotic thrombosis, immune cell infiltration, smooth muscle cell apoptosis, and extracellular matrix degradation. Given that there are no effective target treatments, once ruptured, AAA leads to high mortality with few long-term survivors. The goal of this study is to identify novel key pathways and hub genes involved in AAA formation with the aim of providing promising therapeutic targets for AAA. MATERIALS AND METHODS: The transcriptome sequencing matrix of GSE47472 and GSE57691 were obtained from the GEO database. These datasets were further merged for differential expression analysis, weighted gene co-expression network analysis (WGCNA), and functional enrichment analysis in R (v4.0.2). A co-expression network was constructed with Cytoscape (v3.8.0) to generate the top 30 hub genes. Hub Genes with high clinical traits and potential values were further verified using a receiver operating characteristic (ROC) curve and qPCR analysis. RESULTS: A total of 745 differentially expressed genes were screened and 14 gene co-expression modules were established. Among these 14 modules, pink modules with a total of 118 genes showed the strongest correlation with AAA pathogenesis. Subsequently, 78 genes associated with a highly relevant clinical trait and the top 30 hub genes were intersected to generate 22 genes. Gene ontology functional enrichment analysis of the 22 genes revealed abnormal expression of genes relating to cell-matrix adhesion and integrin-mediated signaling pathway. LAMA5, ITGA8, ITGA1, and FERMT2 were associated with the integrin-mediated signaling pathway and cell-matrix adhesion while ACTN1 and CX3CL1 were simply associated with the latter. Low expressions of LAMA5, ACTN1, ITGA8, ITGA1, and FERMT2 were further verified through qPCR in a mouse model of AAA. CONCLUSIONS: Low expression of partial genes in the integrin signaling pathway was implicated in the function loss of mediated cell-matrix adhesion, which may offer novel targets for therapeutic intervention against AAA.

Quantitative evaluation of the radon and lung cancer association in a case control study of Chinese tin miners.

Studies of underground miners have consistently shown an increased risk of lung cancer with cumulative exposure to radon-222 and its decay products. Although the deleterious effects of high radon exposure are clear, questions regarding the shape of the exposure-response relationship, and the effects of time factors such as attained age, time since exposure and early age at first exposure, the effect of exposure rate, and the joint association of radon exposure and tobacco use have not yet been fully clarified. This report considers these questions by fitting various models for the relative odds of disease to 74 male lung cancer cases who were diagnosed between 1981 and 1984 and were alive in 1985 and an equal number of controls. All subjects are current or past employees of the Yunnan Tin Corporation, Gejiu City, China, who reside in the local area. Workers were interviewed to obtain information on work history, from which radon exposure in cumulative working level months and arsenic exposure were estimated, and on tobacco use. Results indicate that excess relative risk increases by 1.7% per cumulative working level month [95% confidence interval (0.5, 5.4)]. The linear exposure response relationship significantly declines with year since last radon exposure (P = 0.02). The risk trend also declines with increasing exposure rate (P = 0.001), indicating that long duration of exposure at a low rate may be more deleterious than short duration of exposure at a high rate. A unique aspect of this study population is the very early ages at first radon exposure for many of the workers, about 37% of the radon-exposed workers were first exposed under the age of 13 years. The analysis shows no modification of the radon lung cancer relationship with age at first exposure. These patterns of risk with radon exposure are generally consistent with those reported in the recent National Academy of Sciences' Biological Effects of Ionizing Radiations IV report. The primary method of tobacco consumption in this area of China is by waterpipe. Lung cancer risk increases with pipe-years of use. The joint analysis of tobacco use and radon exposure supports the Biological Effects of Ionizing Radiations IV conclusion that the most likely model is between additive and multiplicative. The variations of the radon lung cancer relationship by years since last exposure and exposure rate are not affected by adjustment for arsenic exposure.

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan, China. A pilot study.

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 micrograms of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05 +/- 0.008 microgram/mL) and hair (0.442 +/- 0.085 microgram/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 micrograms Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.

A cohort study in southern China of tin miners exposed to radon and radon decay products.

Several studies of underground miners have demonstrated that exposure to radioactive radon gas (more precisely, 222Rn and its short-lived decay products) at levels historically found in mines increases the risk of lung cancer. Because of small numbers of lung cancers, previous studies have had limited power to evaluate temporal and other characteristics of patterns of risk. Herein we report on a historical cohort study of male employees of the Yunnan Tin Corporation in southern China. The cohort consists of 17,143 workers with 175,143 person-years of observation and 981 lung cancer events. Eighty percent of the workers were employed underground and exposed to radon. The excess relative risk increased linearly with exposure, rising 0.6% per working level month (95% confidence interval = 0.4-0.8). In the mines, workers were also exposed to arsenic-containing dusts. Adjustment for arsenic exposure, a known lung carcinogen, reduced the effect of radon exposure to 0.2% per working level month (95% confidence interval = 0.1-0.2). The excess relative risk/working level month declined significantly with attained age and with radon exposure rate as measured by the cumulative working level month divided by duration of exposure. It also declined significantly with years from last exposure and with time since exposure, but these declines were consistent only after adjustment for arsenic exposure. In this cohort, 41% of the underground workers were first exposed when < 15 y old; however, lung cancer risk did not vary consistently with age at first radon exposure. A joint analysis of radon exposure and smoking status (smoker vs. nonsmoker) rejected both an additive and a multiplicative association; the relationship was consistent with an intermediate association.

Relation of arsenic exposure to lung cancer among tin miners in Yunnan Province, China.

The relation of mining and smelting exposure to arsenic and lung cancer was studied among tin miners in Yunnan Province in the People's Republic of China. Interviews were conducted in 1985 with 107 living tin miners who had lung cancer and an equal number of age matched controls from among tin miners without lung cancer to obtain information on risk factors for lung cancer including detailed history of employment and tobacco use. Occupational history was combined with industrial hygiene data to estimate cumulative arsenic exposure. Similar methods were also used to estimate radon exposure for simultaneous evaluation in this analysis. The results indicate that subjects in the highest quarter of cumulative arsenic exposure have a relative risk of 22.6 compared with subjects without exposure after adjusting for tobacco and radon exposure, and a positive dose response relation was observed. Simultaneous evaluation of arsenic and tobacco exposure indicates a greater risk for arsenic, whereas simultaneous assessment of arsenic and radon exposure suggests radon to be the greater risk. There is no evidence of synergism between arsenic and tobacco exposure. Among arsenic exposed individuals, cases of lung cancer have longer duration but lower average intensity of arsenic exposure than controls, indicating that duration of exposure to arsenic may be more important than intensity in the aetiology of lung cancer. Finally, risk of lung cancer among workers exposed to arsenic only in mining is only slightly less than for miners whose exposure to arsenic was limited to smelting, although risks are highest when workers were exposed to both mining and smelting.

Relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province, China.

We studied the relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province in the People's Republic of China. Interviews were conducted in 1985 with 107 living tin miners with lung cancer and an equal number of age-matched controls from among tin miners without lung cancer to obtain information on lung cancer risk factors including a detailed history of employment and tobacco use. Occupational history was combined with extensive industrial hygiene data to estimate cumulative working level months (WLM) of radon daughter exposure. Similar data were also used to estimate arsenic exposure for control in the analysis. Results indicate an increased risk of lung cancer for water pipe smoking, a traditional form of tobacco use practiced in 91% of cases and 85% of controls. Ever use of water pipes was associated with a twofold elevation in risk when compared with tobacco abstainers, and a dose-response relation was observed with increasing categories of pipe-year (dose times duration) usage. Estimated WLM of radon exposure varied from 0 to 1,761 among subjects but averaged 515 in cases versus only 244 in controls. Analyses indicated that the persons in the highest quarter of the radon exposure distribution had an odds ratio (OR) = 9.5 (95% confidence interval = 2.7-33.1) compared to persons without radon exposure after controlling for arsenic exposure and other potential confounders. Examination of duration and rate of radon exposure indicated higher risk associated with long duration as opposed to high rate of exposure. Cross-categorizations of radon exposure and tobacco use suggest greater risk associated with radon exposure than tobacco in these workers.

Risk of lung cancer among cigarette and pipe smokers in southern China.

Studies in Shanghai and in north-east China indicate that cigarette smoking is a major contributor to the high rates of lung cancer in those areas, but doubts persist regarding the influence of cigarette use on lung cancer rates in other areas of China. In addition, the risk of lung cancer associated with other methods of tobacco consumption--in particular, the use of bamboo water-pipes and long-stem pipes--is uncertain. A population-based case-control study of 427 male lung cancer patients residing in a mining area of Southern China and 1,011 controls was carried out to address this and other issues. Of these patients, 63% smoked cigarettes and (water and long-stem) pipes; 17% and 14% smoked only cigarettes or pipes, respectively; and 6% did not smoke. Compared to non-smokers, smokers of cigarettes only, smokers of pipes only and mixed smokers were at increased risk; OR = 2.6 (95% CI 1.1-6.2), 1.8 (95% CI 0.8-4.2) and 4.1 (95% CI 2.3-9.2), respectively. Risk increased with duration of tobacco use; however, the rate of increase with years of cigarette use was significantly greater than for years of pipe use (p = 0.03). In addition, risks increased 8-fold in the highest quartile of number of cigarettes per day compared to non-cigarette smokers vs. 2.3-fold for the highest quartile of number of liang (50 g) smoked per month compared to non-pipe-smokers; the trends in the ORs differed significantly (p less than 0.001). Results suggest that, in this area of China, tobacco use is an important cause of lung cancer, and that smoking cigarettes may be more deleterious than smoking pipes (primarily water pipes).

Feasibility of conducting a lung-cancer chemoprevention trial among tin miners in Yunnan, P. R. China.

Tin miners in Yunnan Province in southern China have an extremely high rate of lung cancer, more than one percent per year among those at 'high risk' (40+ years old, with 10+ years of underground mining and/or smelting experience). The extraordinary lung cancer rates result from combined exposure to radon, arsenic, and tobacco smoking (cigarettes and/or bamboo water pipe). A study to determine the feasibility of conducting a large-scale, lung-cancer chemoprevention trial was conducted in 1986 among currently employed or retired miners from the Yunnan Tin Corporation in the city of Gejiu. The study was designed to answer four questions: (i) Could potentially eligible miners be identified and recruited? (ii) Could intervention agents be shipped successfully from the United States to the study area and be appropriately distributed? (iii) Would miners adequately adhere to the study protocol and comply with the intervention regimen? (iv) Could potential adverse effects be monitored and documented? The six-month feasibility study yielded affirmative answers to each of these questions. A roster of over 7,000 high-risk miners was compiled. Four agents (vitamin A, 25,000 IU; beta-carotene, 50 mg; vitamin E, 800 IU; and selenium, 400 micrograms) were administered daily with placebos to 350 miners according to a 2(4) factorial design. Adherence, assessed by pill counts and serum micronutrient levels, was approximately 90 percent. The findings from this preliminary study indicate that a full-scale, lung-cancer chemoprevention trial in this population is feasible.