Phylogenetic group B2 Escherichia coli strains from the bowel microbiota of Pakistani infants carry few virulence genes and lack the capacity for long-term persistence

Escherichia coli strains of phylogenetic group B2 obtained from Western human hosts are enriched in virulence-associated genes and have a superior capacity to persist in the colonic microbiota. Here, E . coli strains from 22 infants born in Pakistan whose rectal flora was sampled regularly over the first 6 months of life were examined. B2 strains did not carry the virulence-associated genes sfaD/E , papC , neuB or hlyA more often than strains of other phylogenetic groups . B2 origin was not associated with persistence in the bowel microbiota. As compared with B2 strains from Swedish infants, Pakistani B2 strains carried significantly less often the virulence genes fimH (p 0.04), papC (p 0.02), papG class III (p 0.01), sfaD / E (p ≤0.0001), neuB (p ≤0.0001), and hlyA (p 0.005), and also the high-pathogenicity island (p ≤0.0001). A minority of Pakistani B2 strains belonged to recognized uropathogenic O-groups, which are common among 'Western' B2 strains. Thus, extra-intestinal pathogenicity may be the foremost characteristic of B2 strains colonizing Western populations.     

Norovirus seasonality and the potential impact of climate change

Seasonal variation in norovirus infection is a recognized but poorly understood phenomenon. It is likely to be based on biological, environmental and behavioural factors that regulate transmission, virulence and persistence of the virions in host populations. Understanding the seasonal dependency of norovirus infection is an important step towards understanding its epidemiology, with subsequent implementation of efficient measures of surveillance and control. Whether or not climate change could influence the seasonal patterns of norovirus infection, by impacting on its transmission, geographic distribution and prevalence, has not yet been considered. This review addresses the question.     

Memory impairment induced by IL-1β is reversed by α-MSH through central melanocortin-4 receptors

Interleukin-1beta (IL-1β) significantly influences memory consolidation. Treatments that raise the level of IL-1β in the brain, given after training, impair contextual fear conditioning. The melanocortin α-MSH exerts potent anti-inflammatory actions by physiologically antagonizing the effect of pro-inflammatory cytokines. Five subtypes of melanocortin receptors (MC1R–MC5R) have been identified, with MC3R and MC4R predominating in the central nervous system. The present experiments show that injection of IL-1β (5 ng/0.25 μl) in dorsal hippocampus up to 15 min after training decreased freezing during the contextual fear test. The treatment with IL-1β (5 ng/0.25 μl) 12 h after conditioning cause amnesia when animals were tested 7 days post training. Thus, our results also demonstrated that IL-1β can influence persistence of long-term memory. We determined that animals previously injected with IL-1β can acquire a new contextual fear memory, demonstrating that the hippocampus was not damaged. Treatment with α-MSH (0.05 μg/0.25 μl) blocked the effect of IL-1β on contextual fear memory. Administration of the MC4 receptor antagonist HS014 (0.5 μg/0.25 μl) reversed the effect of α-MSH. However, treatment with γ-MSH (0.5 μg/0.25 μl), an MC3 agonist, did not affect IL-1β-induced impairment of memory consolidation. These results suggest that α-MSH, through central MC4R can inhibit the effect of IL-1β on memory consolidation.     

长期单眼配戴角膜塑形镜对眼表的影响

目的：探讨持续单眼配戴角膜塑形镜对眼表的影响。

方法：回顾性研究2013-01/2015-12在无锡市101医院眼科门诊就诊的单眼近视眼(对侧眼为正视眼)持续配戴角膜塑形镜6mo以上的患者。观察戴镜眼和非戴镜眼在戴镜前和戴镜后各时间点(1wk,1、3、6mo)的泪膜破裂时间、泪液基础分泌量、角膜中央厚度、角膜内皮细胞密度、结膜充血、角膜上皮荧光素染色的情况。

结果：单眼持续配戴角膜塑形镜患者共53例,年龄10.43±1.70岁,等效球镜度-3.37±1.50D。戴镜眼戴镜1wk泪膜破裂时间缩短,戴镜后1wk与戴镜后1、3、6mo泪膜破裂时间相比,差异无统计学意义(P>0.05); 非戴镜眼泪膜破裂时间各时间点无明显差异(P>0.05)。戴镜眼和非戴镜眼戴镜后各时间点泪液基础分泌量与戴镜前相比,差异均不明显(P>0.05)。戴镜后各时间点角膜中央厚度和角膜内皮细胞密度与戴镜前比较,差异均无统计学意义(P>0.05)。戴镜眼角膜上皮染色主要为Ⅰ级点染,Ⅰ级点染在戴镜后1wk,1、3、6mo分别为10眼(19%)、6眼(11%)、8眼(15%)、6眼(11%),Ⅱ级点染分别为1眼(2%)、0眼、0眼、1眼(2%)。10例患者戴镜后会出现结膜充血(评分1分)。所有病例在及时停戴、使用抗生素及角膜修复剂后,角膜上皮点状染色均消失,结膜充血消退。非戴镜眼观察期内未见明显结膜充血,角膜上皮染色均为0级。

结论：持续配戴角膜塑形镜会引起泪膜稳定性的下降,结膜、角膜上皮会出现不同程度的影响,但对泪液分泌、角膜厚度和角膜内皮细胞无明显影响。非戴镜眼无明显眼表损害。     

Electrophysiological correlates of personality dimensions measured by Temperament and Character Inventory

The present exploratory study was attempted to investigate the relationship between components of event-related potential (ERP) and Cloninger's personality dimensions. The ERP was measured using the auditory oddball paradigm, and personality was evaluated by Temperament and Character Inventory (TCI) in 25 healthy subjects. The results showed that P300 amplitude at Fz was significantly associated with reward dependence, and that P300 latency was positively correlated with persistence, and negatively correlated with novelty seeking. No correlations were found between N100, P200 and personality dimensions. These results indicate that personality dimension is related to information-processing in the brain. The neurobiological and psychological aspects of personality, which may relate to the P300 were considered.     

Spatial-frequency- and contrast-dependent visible persistence and reading disorder: no evidence for a basic perceptual deficit

Summary. The aetiology of dyslexia is still unclear, the most widely and controversially discussed theory is the magnocellular deficit hypothesis. One of the first and most influential paradigms used to investigate this visual deficit in dyslexia is the visible persistence (VP). However results on VP are decisively influenced by the method measuring VP. Lovegrove et al. (1986) repeatedly found a longer VP in reading disabled children which is significantly influenced by spatial frequency and contrast. However, these results were not investigated with the same method to date. Seventy-six unselected 2^nd grade students (41 boys, 35 girls) of a rural primary school were investigated with an identical experimental design comparable to the Lovegrove et al. (1986) studies. Comparing reading disabled (n=17) with controls (n=34) no evidence for a longer VP in the reading disabled group was found. Additionally, correlation analysis revealed no evidence for a significance of VP for spelling, phoneme awareness and speech discrimination. This study does not encourage either a magnocellular nor parvocellular deficit in dyslexia.     

Selection of an Escherichia coli O157:H7 bacteriophage for persistence in the circulatory system of mice infected experimentally

A bacteriophage lytic for Escherichia coli O157:H7 was isolated from bovine manure. Following in-vivo selection, the phage acquired the capacity to persist in the circulatory system of mice for at least 38 days. When mice were infected experimentally with E. coli O157:H7 (10(7) CFU/mouse), simultaneous injection of the mice with phage (10(8) PFU/mouse) cleared E. coli O157:H7 from the mice within 48 h.