Diagnostic and epidemiological significance of F-donor activity of Enterobacteria strains

The study of the circulating strains of enteropathogenic Escherichia coli (EPEC), shigellae and salmonellae for the presence of F-factor (the conjunction factor) was carried out. The study revealed that 85% of Shigella flexneri strains 2a had conjugative (F)-factor. The proportion of such strains was 63% among EPEC of different serovars and 15% among Salmonella enteritidis. As 63% EPEC strains had hemolytic activity and were found to carry F-conjugative plasmid it should be taken into consideration in the identification of microorganisms. The presence of conjugation plasmids is an important epidemiological marker.     

Conjugation resistance to Fusarium graminearum Schwabe with multiple molecular forms of some enzymes in winter wheat

Electrophoretic spectra of multiple molecular forms of peroxidase (EC 1.11.1.7), superoxide dismutase (EC 1.15.1.1), phenol oxidase (EC 1.10.3.1), and cytochrome oxidase (EC 1.9.3.1) in seedlings of two aegilops species and eleven genotypes of bread winter wheat differing in the level of their resistance to Fusarium infection are presented. Several izoforms of peroxidase, phenol oxidase, and superoxide dismutase correlate with the level of resistance to Fusarium. Infection of plants with the pathogen enhances expressiveness of some multiple forms of enzymes. Such response to infection in less pronounced in the sensitive genotypes as compared with that in the resistant ones.     

Characteristics of immune response in acute intestinal enterobacterial infections

Update literature on the problem of microorganism--host interactions with pathogenic enterobacteria as a model is reviewed. The activation of lymphoid cells and their protective role is shown to be due to the stimulating action of bacterial antigens. The role of cytokines and stimulation of their expression are discussed. Some phenomena of immunosuppression, phases of enteric mucosal immune response are described.     

Effect of temperature on seed production in the invasive grass Glyceria maxima (Hartm.) Holmb. (Poaceae) in South Africa

Temperature is one of the main factors that determine sexual reproduction in terrestrial and emergent aquatic plant species. The effect of temperature on sexual reproduction and seed production of Glyceria maxima (Hartm.) Holmb. in the southern hemisphere is unknown. Glyceria maxima collections in February 2010 at three isolated infestations in KwaZulu-Natal failed to yield a single seed, only empty panicles. Laboratory experiments showed that vernalisation had no consistent effect on seed production. Field- and laboratory-grown plants produced seeds in the 2010/2011 season, because of having sufficient time at optimum temperatures required for seed production (1 491 and 1 585 hours, respectively), compared to a shorter period (1 352 hours) of suitable temperatures during the 2009/2010 growing season. An inadequate period of optimum temperatures (15–25°C) during seed production resulted in the lack of seeds in the field in the 2009/2010 growing season. This study showed that temperature and duration of exposure thereto during the seed-production period play vital roles in G. maxima sexual reproduction.     

Isocitrate dehydrogenase 1 R132C mutation occurs exclusively in microsatellite stable colorectal cancers with the CpG island methylator phenotype

The CpG Island Methylator Phenotype (CIMP) is fundamental to an important subset of colorectal cancer; however, its cause is unknown. CIMP is associated with microsatellite instability but is also found in BRAF mutant microsatellite stable cancers that are associated with poor prognosis. The isocitrate dehydrogenase 1 (IDH1) gene causes CIMP in glioma due to an activating mutation that produces the 2-hydroxyglutarate oncometabolite. We therefore examined IDH1 alteration as a potential cause of CIMP in colorectal cancer. The IDH1 mutational hotspot was screened in 86 CIMP-positive and 80 CIMP-negative cancers. The entire coding sequence was examined in 81 CIMP-positive colorectal cancers. Forty-seven cancers varying by CIMP-status and IDH1 mutation status were examined using Illumina 450K DNA methylation microarrays. The R132C IDH1 mutation was detected in 4/166 cancers. All IDH1 mutations were in CIMP cancers that were BRAF mutant and microsatellite stable (4/45, 8.9%). Unsupervised hierarchical cluster analysis identified an IDH1 mutation-like methylation signature in approximately half of the CIMP-positive cancers. IDH1 mutation appears to cause CIMP in a small proportion of BRAF mutant, microsatellite stable colorectal cancers. This study provides a precedent that a single gene mutation may cause CIMP in colorectal cancer, and that this will be associated with a specific epigenetic signature and clinicopathological features.     

奥美拉唑联合法莫替丁治疗反流性食管炎的临床效果分析

目的：观察并分析奥关拉唑联合法莫替丁治疗反流性食管炎的临床效果。方法：选取2008年5月至2012年5月在本院确诊并治疗的反流性食管炎患者45例,随机平均分为三组。联合用药组（15例）：每日早餐前口服20mg奥关拉唑,睡前口服20mg法莫替丁;奥关拉唑组（15例）：每日口服两次奥美拉唑,每次20mg;法莫替丁组（15例）：每日口服两次法莫替丁,每次20mg。每组的治疗时间均为8周。在内镜指导下观察并比较三组患者的胸痛、反酸和烧心等主要病征的改善情况,综合评价三种治疗方法的临床疗效。结果：联合用药组较其他两组获得的疗效更明显,患者的症状得到较好的改善,差异有统计学意义（P〈0．05）。结论：奥美拉唑联合法莫替丁能够有效地抑制胃酸的分泌,对于反流性食管炎的,临床治疗具有良好的效果。     

Theory in motion

Modeling studies are now a significant part of mainstream research in motor control. Novel and classical modeling techniques used in recent work on small and large motor systems illustrate the different roles that models play in furthering our understanding of motor systems. The models presented reveal single neuron short-term memory, unexpected effects of reciprocal inhibition and methods for decoding activity in large populations of neurons.