Helicobacter spp. Other Than Helicobacter pylori

Non- H. pylori Helicobacter species (NHPHS) are associated with several important human and animal diseases. In the past year research into this group of bacteria has continued to gain attention, and novel species have been described in new niches owing to improvements in detection methods. Polymerase chain reaction and/or sequencing remain the gold standard for the detection of this genus. New insights into the pathogenesis of the NHPHS in hepatobiliary, gastric, and intestinal diseases were gained. In particular, data revealed interaction between hepatic steatosis and infectious hepatitis in the development of hepatocellular carcinoma. Evidence of an association between hepatitis C virus and Helicobacter spp. in hepatocarcinoma development was also provided; and male sex hormone signaling appeared to influence infectious hepatitis induced by Helicobacter hepaticus . More findings support an association between Helicobacter heilmannii and gastric adenocarcinoma; and in mice, mucins MUC4 and MUC5 but not MUC1 influence the colonization and pathogenesis of Helicobacter felis . Data indicated that the roles of the adaptive immune system in H. hepaticus -induced intestinal tumorigenesis are different in the small and large intestines, and environmental factors, such as bile acids may modulate H. hepaticus carcinogenic potential. New reports in the prevention and eradication of NHPHS showed a protective response against Helicobacter suis induced by vaccine administration, and a successful cross-foster rederivation method successfully eradicated Helicobacter spp. from contaminated mice litters. Overall, the studies provided insights into the pathophysiology of Helicobacter species other than Helicobacter pylori.     

Long-term Administration of Probiotics to Asymptomatic Pre-school Children for Either the Eradication or the Prevention of Helicobacter pylori Infection

Background:  The role of probiotics in the armamentarium remains to be defined. The aims of this study were to investigate whether the long-time administration of Lactobacillus gasseri OLL2716 (LG21) strain can eradicate H. pylori in asymptomatic pre-school children and/or prevent H. pylori infection.
Methods: A total of 440 children, from 5–7 years of age, attending a kindergarten in Thailand were screened by the Helicobacter pylori stool antigen (HpSA) test. Thereafter 132 H. pylori positive and 308 H. pylori negative children were recruited to eradication and randomized prevention arms, respectively. Children in the active and placebo treatment groups received Lactobacillus gasseri OLL2716 (LG21) containing cheese and ordinary cheese, respectively, for 12 months. Eradication was defined as reversion by HpSA at 12 months. Prevention was defined as persistently HpSA negative at 12 months.
Results:  Eighty-two of 132 H. pylori positive (62%) completed the eradication arm, of which 24 (29.3%) were negative at 12 months according to the HpSA test. In the randomized prevention arm, 123 of 156 (79%) and 99 of 122 (81%) completed active and placebo arms, respectively, of which 4.1% and 8.1%, respectively, were HpSA positive at 12 months based on a per-protocol analysis ( p  = .21).
Conclusion: Further trials are needed.     

Phytoestrogens as natural prodrugs in cancer prevention: dietary flavonoids

There are many reasons why vegetables and fruits may protect against cancer. As well as containing vitamins and minerals, which help keep the body healthy and strengthen the immune system, they are also good sources of biologically active compounds, which can help to protect cells in the body from damage that can lead to cancer. Notably, dietary flavonoids and other polyphenols are thought to have an important role as chemopreventive agents. Most studies on the possible mechanism of the chemopreventive action of dietary compounds have assumed that free hydroxyl groups of flavonoids and other polyphenols are necessary for their biological effects. However, in the human body dietary polyphenols are rapidly conjugated by glucuronosyltransferases and sulfotransferases, two enzymes that are abundantly present in the small intestine and liver, through which all of the oral dose must pass. Thus, most polyphenols that have been studied, e.g. quercetin, kaempferol, diosmetin, and resveratrol, would not be expected to reach internal organs beyond sites directly along the gastrointestinal tract. When the hydroxyl groups in polyphenols are methylated, the resulting compounds are much less prone to glucuronidation and sulfation. Thus methoxylated compounds are more metabolically stable, increasing their bioavailablity. The peel of various Citrus species can contain high concentrations of polymethoxyflavones, whereas the juice mainly contains hydroxylated flavones. At present, very little is known about the mechanisms by which methoxylated flavones may affect growth and development of tumour cells. Recently, it was shown that tumour specific enzymes can catalyze the O-demethylation of methoxylated flavones, resulting in the formation of flavones with free hydroxyl groups. We propose that demethylation of methoxylated flavones is another example of bioactivation of naturally occurring prodrugs.     

抗生素与抗菌药物协同作用防控生物膜的研究进展

生物膜(Biofilm)是指微生物为适应周围环境,黏附于介质表面并被其自身分泌的胞外基质包裹而形成的一种复杂的、高度异质的聚合结构。生物膜对宿主防御和药物具有很强的抵御能力,使用单一药物防治往往效果不显著,而利用协同作用将不同抗菌药物的优势联合起来用于生物膜的防控则优势明显。重点阐述了抗生素与抗生素、抗生素与中药、抗生素与噬菌体、抗生素与酶的协同作用研究,以期为生物膜的防控提供新思路。     

The Thr300Ala variant of ATG16L1 is associated with decreased risk of brain metastasis in patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) often metastasizes to the brain, but identifying which patients will develop brain metastases (BM) is difficult. Macroautophagy/autophagy is critical for cancer initiation and progression. We hypothesized that genetic variants of autophagy-related genes may affect brain metastases (BM) in NSCLC patients. We genotyped 16 single nucleotide polymorphisms (SNPs) in 7 autophagy-related (ATG) genes (ATG3, ATG5, ATG7, ATG10, ATG12, ATG16L1, and MAP1LC3/LC3) by using DNA from blood samples of 323 NSCLC patients. Further, we evaluated the potential associations of these genes with subsequent BM development. Lung cancer cell lines stably transfected with ATG16L1: rs2241880 (T300A) were established. Mouse models of brain metastasis were developed using cells transfected with ATG16L1–300T or ATG16L1–300A. ATG10: rs10036653 and ATG16L1: rs2241880 were significantly associated with a decreased risk of BM (respective hazard ratios [HRs]=0.596, 95% confidence interval [CI] 0.398–0.894, P = 0.012; and HR = 0. 655, 95% CI 0.438–0.978, P = 0.039, respectively). ATG12: rs26532 was significantly associated with an increased risk of BM (HR=1.644, 95% CI 1.049–2.576, P = 0.030). Invasion and migration assays indicated that transfection with ATG16L1–300T (vs. 300A) stimulated the migration of A549 cells. An in vivo metastasis assay revealed that transfection with ATG16L1–300T (vs. 300A) significantly increased brain metastasis. Our results indicate that genetic variations in autophagy-related genes can predict BM and that genome analysis would facilitate stratification of patients for BM prevention trials.     

中国东北地区非点源污染研究进展

为掌握东北地区非点源污染研究动态和明确研究中存在的问题和不足,对近20年（1991-2008年）东北地区有关非点源污染研究成果进行检索、分类和统计分析,以便更好地进行区域水环境治理和污染防治.东北地区非点源污染研究总体呈增加趋势;研究内容包括水环境污染源调查分析与评价、污染负荷量化、机理探索、模型模拟和污染防治5类;研究对象包括氮、磷、泥沙、农药和重金属;经验方法估算污染负荷较多,机理模型应用成功实例较少;研究性论文中以农业非点源污染较多,城市非点源污染较少;治理措施停留在水土保持措施层面上,缺乏对水土保持措施的优选评价和对最佳管理措施的评价研究.目前,东北地区非点源污染研究处在理论探索阶段,非点源污染是否是主要污染源还存在争议.今后应着力于措施应用、评价和基础数据收集及区域非点源污染物的确定和污染负荷的量化研究;尝试新技术和多领域交叉合作,为区域水环境治理提供科学依据.