幽门螺杆菌感染相关因素的研究进展

幽门螺杆菌（HP）是革兰阴性微需氧的螺旋样杆菌，主要通过口-口途径在人-人之间感染传播。HP的发现加深了人类对慢性感染、炎症和癌症之间关系的认识。其特定的螺旋形体型、鞭毛及动力、尿素酶和黏附素活性，以及细胞毒素基因A（cagA）、空泡细胞毒素基因A（vacA）等是影响HP感染研究较多的相关致病因素。HP感染在胃癌的发生、发展中可能具有重要作用，但尚未确切证实HP感染是导致胃癌的主因。文章概述了HP感染相关致病因素的研究进展。     

Validation of the Knowledge of Genome Sequencing (KOGS) scale in cancer patients

IntroductionThe Knowledge of Genome Sequencing (KOGS) questionnaire was recently developed to measure knowledge of genomic sequencing (GS), with preliminary psychometric data supporting its reliability and validity. The aim of this study was to test the reliability and validity of the KOGS in a larger sample, and to confirm its utility in a cancer setting.MethodsThe Genetic Cancer Risk in the Young (RisC) study recruits participants with a personal history of cancer, to investigate heritable cancer causes and future cancer risk using germline GS. Participants (n = 261) in a psychosocial substudy of RisC completed a questionnaire after consent to RisC but before GS, including the KOGS, the Intolerance of Uncertainty Scale, the Chew health literacy scale and items assessing demographic and disease variables. Confirmatory factor analysis (CFA), Cronbach alpha and correlational analyses were undertaken.ResultsThe CFA testing a single-factor model yielded a good model fit, χ2/df = 2.43, comparative fit index (CFI) = 0.97, root mean square error of approximation (RMSEA) = 0.07 and weighted mean root square (WRMR) = 1.03. Factor loadings of all items were above 0.60 and ranged between.66 and.93. The single factor score demonstrated excellent internal consistency (α = 0.82). KOGS scores were significantly associated with health literacy (r = 0.23, p < .001), having a university education [t(258) = ?4.53, p < .001] and having a medical or science background [t(259) = ?3.52, p < .001] but not with speaking a language other than English at home, time since diagnosis, previous genetic counselling/testing or intolerance of uncertainty.DiscussionThis study confirmed a single-factor structure for the KOGS, and its reliability and validity in a cancer population. Associations with measures of health literacy and education were significant and positive as expected, supporting the KOG’s construct validity. Previous genetic counselling may not be sufficient to provide specific knowledge of GS.     

Hepatitis B virus DNA in the fingernails and hair of children with acute hepatitis B

Hepatitis B virus (HBV) DNA is detectable in the nails and hair of patients with chronic HBV infection. However, it remains unclear whether HBV DNA can be detectable in the nails and hair of patients with acute HBV infection. We encountered two cases of children with acute HBV infection. HBV DNA in the nails and hair from the two children was evaluated by real-time PCR. To clarify the characteristics of HBV DNA, full-length HBV genome sequencing and phylogenetic tree analysis were performed. The levels of serum HBV DNA in children of cases 1 and 2 at day 0 were 7.6 Log IU/mL and 7.4 Log IU/mL, respectively. Nail HBV DNA was detected in both children (case 1: 4.6 Log IU/mL at day 0, case 2: 5.5 Log IU/mL at day 14). Moreover, hair HBV DNA was detectable in case 2 (4.0 Log IU/mL at day 14). Serum HBV DNA became undetectable within approximately 3–4 months after the first hospital visit. After the resolution of HBV viremia, nail and hair HBV DNA became undetectable. The sequence analysis of serum, nail and hair HBV DNA showed the same HBV genotype in each case (case1: genotype C, case 2: genotype A). In case 1, 3 nucleotides were different in the full-genome HBV sequence between the serum and nails. In case 2, the full-genome HBV sequences were identical among the serum, nails and hair. In conclusion, HBV DNA was detectable in nails and hair of children with acute HBV infection.     

Decoding and rejuvenating human ageing genomes: Lessons from mosaic chromosomal alterations

One of the most curious findings emerged from genome-wide studies over the last decade was that genetic mosaicism is a dominant feature of human ageing genomes. The clonal dominance of genetic mosaicism occurs preceding the physiological and physical ageing and associates with propensity for diseases including cancer, Alzheimer’s disease, cardiovascular disease and diabetes. These findings are revolutionizing the ways biologists thinking about health and disease pathogenesis. Among all mosaic mutations in ageing genomes, mosaic chromosomal alterations (mCAs) have the most significant functional consequences because they can produce intercellular genomic variations simultaneously involving dozens to hundreds or even thousands genes, and therefore have most profound effects in human ageing and disease etiology. Here, we provide a comprehensive picture of the landscapes, causes, consequences and rejuvenation of mCAs at multiple scales, from cell to human population, by reviewing data from cytogenetic, genetic and genomic studies in cells, animal models (fly and mouse) and, more frequently, large-cohort populations. A detailed decoding of ageing genomes with a focus on mCAs may yield important insights into the genomic architecture of human ageing, accelerate the risk stratification of age-related diseases (particularly cancers) and development of novel targets and strategies for delaying or rejuvenating human (genome) ageing.