Helicobacter pylori infection occurs via close contact with infected individuals in early childhood

BACKGROUND: The manner in which Helicobacter pylori is transmitted is of fundamental importance when considering strategies for its control, yet, to date, the exact mode of transmission remains uncertain. METHODS: The seroprevalence of H. pylori in a relatively isolated rural town in Japan (A-town) was examined to analyse the H. pylori infection route. The immunoglobulin G antibodies against H. pylori in 1684 subjects who had received public health examinations in A-town were determined with an enzyme-linked immunosorbent assay. The seroprevalence was compared in five areas according to the water source. The possibility and frequency of intrafamilial infection was analysed by comparing the seroprevalence among family members residing in the same home. RESULTS: The seroprevalence of H. pylori did not differ significantly between the five areas examined. Seropositivity was significantly more common in the children whose mothers were seropositive (45.0%, 27/60) than in the children whose mothers were seronegative (10.0%, 2/20; odds ratio (OR) = 7.36, P = 0.0036, 95% confidence interval (CI) = 1.57-34.59). Seropositivity was significantly more common in the children whose older siblings were seropositive (55.0%, 22/40) than in the children whose older siblings were seronegative (23.5%, 20/85; OR = 3.97, P = 0.00051, 95% CI = 1.79-8.84). There was no significant relationship in seroprevalence between children and fathers, grandchildren and grandfathers, grandchildren and grandmothers, or within couples. Seropositivity was significantly more common in the adolescents who had attended a nursery school (44.4%, 20/45) than in the adolescents who had not attended a nursery school (25.6%, 109/426) (OR = 2.33, P = 0.0070, 95% CI = 1.24-4.36). CONCLUSIONS: The acquisition of H. pylori infection occurs by close contact with infected individuals in early childhood, especially via contact with infected mothers and other infected children.     

Global and Local Persistence of Influenza A(H5N1) Virus

An understanding of the global migration dynamics of highly pathogenic avian influenza A(H5N1) virus is helpful for surveillance and disease prevention. To characterize the migration network of this virus, we used genetic analysis, which supported a global persistence model in which each of 9 regions acts to some extent as a source. Siberia is the major hub for the dispersal of the virus. Southeast Asia and Africa are major sources of genetically and antigenically novel strains. We found evidence of local persistence of the virus in Southeast Asia and Africa, which is rare for human influenza A viruses. The differences in migration dynamics between avian and human influenza viruses might help with the design of region-specific surveillance efforts and the selection of vaccine candidates.     

太阳能热水系统在医院洗浴热水供应中的应用

文章通过太阳能热水系统与热媒换热系统、空气源热泵热水机组系统联合应用于山东省某医院洗浴热水系统中的实例,论述了系统的组成和工作原理,并分析其经济性。     

Astrocyte‐restricted disruption of connexin‐43 impairs neuronal plasticity in mouse barrel cortex

There is intensive gap‐junctional coupling between glial processes, but their significance in sensory functions remains unknown. Connexin‐43 (Cx43), a major component of astrocytic gap‐junction channels, is abundantly expressed in astrocytes. To investigate the role of Cx43‐mediated gap junctions between astrocytes in sensory functions, we generated Cx43 knockout (KO) mice with a mouse line carrying loxP sites flanking exon 2 of the Cx43 gene and the transgenic line expressing Cre recombinase under control of the glial fibrillary acidic protein promoter, which exhibited a significant loss of Cx43 in astrocytes in the barrel cortex. Although Cx43 expression between the astrocytes measured by immunohistochemistry was virtually abolished in Cx43 KO mice, they had normal architecture in the barrel cortex but the intensity of cytochrome oxide histochemistry decreased significantly. In vivo electrophysiological analysis revealed that the long‐term potentiation of the vibrissal evoked responses in the barrel cortex evoked by high‐frequency rhythmic vibrissal stimuli (100 Hz, 1 s) was abolished in Cx43 KO mice. Current source density analysis also revealed that astrocytic Cx43 was important to the flow of excitation within the laminar connections in barrel cortex. Behavioral tests showed that the ability of Cx43 KO mice to sense the environment with their whiskers decreased. Even so, the jump‐stand experiment showed that they could still discriminate rough from smooth surfaces. Our findings suggest that Cx43‐mediated gap‐junctional coupling between astrocytes is important in the neuron–glia interactions required for whisker‐related sensory functions and plasticity.     

Optimization of retinotopy constrained source estimation constrained by prior

Studying how the timing and amplitude of visual evoked responses (VERs) vary between visual areas is important for understanding visual processing but is complicated by difficulties in reliably estimating VERs in individual visual areas using noninvasive brain measurements. Retinotopy constrained source estimation (RCSE) addresses this challenge by using multiple, retinotopically mapped stimulus locations to simultaneously constrain estimates of VERs in visual areas V1, V2, and V3, taking advantage of the spatial precision of fMRI retinotopy and the temporal resolution of magnetoencephalography (MEG) or electroencephalography (EEG). Nonlinear optimization of dipole locations, guided by a group‐constrained RCSE solution as a prior, improved the robustness of RCSE. This approach facilitated the analysis of differences in timing and amplitude of VERs between V1, V2, and V3, elicited by stimuli with varying luminance contrast in a sample of eight adult humans. The V1 peak response was 37% larger than that of V2 and 74% larger than that of V3, and also ～10–20 ms earlier. Normalized contrast response functions were nearly identical for the three areas. Results without dipole optimization, or with other nonlinear methods not constrained by prior estimates were similar but suffered from greater between‐subject variability. The increased reliability of estimates offered by this approach may be particularly valuable when using a smaller number of stimulus locations, enabling a greater variety of stimulus and task manipulations. Hum Brain Mapp 35:1815–1833, 2014. © 2013 Wiley Periodicals, Inc.     

How ‘love’ and ‘hate’ differ from ‘sleep’: Using combined electro/magnetoencephalographic data to reveal the sources of early cortical responses to emotional words

Emotional words—as symbols for biologically relevant concepts—are preferentially processed in brain regions including the visual cortex, frontal and parietal regions, and a corticolimbic circuit including the amygdala. Some of the brain structures found in functional magnetic resonance imaging are not readily apparent in electro‐ and magnetoencephalographic (EEG; MEG) measures. By means of a combined EEG/MEG source localization procedure to fully exploit the available information, we sought to reduce these discrepancies and gain a better understanding of spatiotemporal brain dynamics underlying emotional‐word processing. Eighteen participants read high‐arousing positive and negative, and low‐arousing neutral nouns, while EEG and MEG were recorded simultaneously. Combined current‐density reconstructions (L2‐minimum norm least squares) for two early emotion‐sensitive time intervals, the P1 (80–120 ms) and the early posterior negativity (EPN, 200–300 ms), were computed using realistic individual head models with a cortical constraint. The P1 time window uncovered an emotion effect peaking in the left middle temporal gyrus. In the EPN time window, processing of emotional words was associated with enhanced activity encompassing parietal and occipital areas, and posterior limbic structures. We suggest that lexical access, being underway within 100 ms, is speeded and/or favored for emotional words, possibly on the basis of an “emotional tagging” of the word form during acquisition. This gives rise to their differential processing in the EPN time window. The EPN, as an index of natural selective attention, appears to reflect an elaborate interplay of distributed structures, related to cognitive functions, such as memory, attention, and evaluation of emotional stimuli. Hum Brain Mapp 35:875–888, 2014. © 2012 Wiley Periodicals, Inc.     

Healthy pregnant women in Canada are consuming more dietary protein at 16- and 36-week gestation than currently recommended by the Dietary Reference Intakes,primarily from dairy food sources

Adequate dietary protein intake throughout pregnancy is essential to ensure healthy fetal development. Insufficient and excessive maternal dietary protein intakes are both associated with intrauterine growth restriction, resulting in low birth weight infants. The aim of this study was to analyze the dietary protein intake patterns of healthy pregnant women in Vancouver, British Columbia, during early and late gestation. We hypothesized that women would be consuming higher protein during late stages of pregnancy compared with early stages of pregnancy. Interviewer-administered food frequency questionnaires were collected prospectively from 270 women at 16- and 36-week gestation; food frequency questionnaires from 212 women met study criteria. Maternal anthropometrics at both stages and infant weight at birth were collected. Wilcoxon signed rank tests were used to determine significant gestational differences in protein intakes. Spearman correlation was used to determine the influence of protein intakes and maternal anthropometrics on pregnancy outcomes. Median (25th and 75th percentiles) protein intakes adjusted for body weight were 1.5 (1.18 and 1.79) and 1.3 (1.04 and 1.60) g/kg per day at 16- than 36-week gestation, respectively. Primary protein sources were identified as dairy products. Protein intakes were negatively correlated with birth weight (P < .05), whereas maternal height, weight, body mass index, and weight gain to 36-week gestation were positively correlated with birth weight (P < .05). This study provides current dietary protein intake patterns among healthy Canadian women during pregnancy and indicates higher intakes than current Dietary Reference Intakes recommended dietary allowance of 1.1 g/kg per day, especially during early gestation.     

Strength estimation of a moving 125Iodine source during implantation in brachytherapy: application to linked sources

This study sought to demonstrate the feasibility of estimating the source strength during implantation in brachytherapy. The requirement for measuring the strengths of the linked sources was investigated. The utilized sources were ¹²⁵I with air kerma strengths of 8.38–8.63 U (μGy m² h^–1). Measurements were performed with a plastic scintillator (80 mm × 50 mm × 20 mm in thickness). For a source-to-source distance of 10.5 mm and at source speeds of up to 200 mm s^–1, a counting time of 10 ms and a detector-to-needle distance of 5 mm were found to be the appropriate measurement conditions. The combined standard uncertainty (CSU) with the coverage factor of 1 (k = 1) was ∼15% when using a grid to decrease the interference by the neighboring sources. Without the grid, the CSU (k = 1) was ∼5%, and an 8% overestimation due to the neighboring sources was found to potentially cause additional uncertainty. In order to improve the accuracy in estimating source strength, it is recommended that the measurment conditions should be optimized by considering the tradeoff between the overestimation due to the neighboring sources and the intensity of the measured value, which influences the random error.