Although the intestinal microbiome has been increasingly implicated in autoimmune diseases, much is unknown about its roles in Multiple Sclerosis (MS). Our aim was to compare the microbiome between ...treatment-naïve MS subjects early in their disease course and controls, and between Caucasian (CA), Hispanic (HA), and African American (AA) MS subjects. From fecal samples, we performed 16S rRNA V4 sequencing and analysis from 45 MS subjects (15 CA, 16 HA, 14 AA) and 44 matched healthy controls, and whole metagenomic shotgun sequencing from 24 MS subjects (all newly diagnosed, treatment-naïve, and steroid-free) and 24 controls. In all three ethnic groups, there was an increased relative abundance of the same single genus, Clostridium, compared to ethnicity-matched controls. Analysis of microbiota networks showed significant changes in the network characteristics between combined MS cohorts and controls, suggesting global differences not restricted to individual taxa. Metagenomic analysis revealed significant enrichment of individual species within Clostridia as well as particular functional pathways in the MS subjects. The increased relative abundance of Clostridia in all three early MS cohorts compared to controls provides candidate taxa for further study as biomarkers or as etiologic agents in MS.
The potential for Planck to detect clusters of dusty, star-forming galaxies at z > 1 is tested by examining the Herschel-SPIRE images of Planck Early Release Compact Source Catalog sources lying in ...fields observed by the Herschel Multitiered Extragalactic Survey. Of the 16 Planck sources that lie in the ∼90 sq. deg. examined, we find that 12 are associated with single bright Herschel sources. The remaining four are associated with overdensities of Herschel sources, making them candidate clusters of dusty, star-forming galaxies. We use complementary optical/near-IR data for these 'clumps' to test this idea, and find evidence for the presence of galaxy clusters in all four cases. We use photometric redshifts and red sequence galaxies to estimate the redshifts of these clusters, finding that they range from 0.8 to 2.3. These redshifts imply that the Herschel sources in these clusters, which contribute to the detected Planck flux, are forming stars very rapidly, with typical total cluster star formation rates >1000 M yr−1. The high-redshift clusters discovered in these observations are used to constrain the epoch of cluster galaxy formation, finding that the galaxies in our clusters are 1-1.5 Gyr old at z ∼ 1-2. Prospects for the discovery of further clusters of dusty galaxies are discussed, using not only all sky Planck surveys, but also deeper, smaller area, Herschel surveys.
Summary
Background
Helicobacter pylori prevalence in Western countries has been declining simultaneously with increases in childhood asthma and allergic diseases; prior studies have linked these ...phenomena.
Aims
To examine the association between H. pylori colonisation in children and risk of asthma and related conditions at school age. We secondly examined additional effects of maternal H. pylori status by pairing with children's status.
Methods
This study was embedded in a multi‐ethnic population‐based cohort in Rotterdam, The Netherlands. We measured anti‐H. pylori and anti‐CagA antibodies in serum of children obtained at age 6 years, and of their mothers obtained during midpregnancy. Asthma or related conditions were reported for children at age 6 years. We used multivariate logistic regression analyses among 3797 subjects.
Results
In children, the H. pylori positivity rate was 8.7%, and 29.2% of these were CagA‐positive. A child's colonisation with a CagA‐negative‐H. pylori strain was associated with an increased risk of asthma (Odds ratio 2.11; 95% CI 1.23–3.60), but this differed for European (3.64; 1.97–6.73) and non‐European (0.52; 0.14–1.89) children. When taking into account maternal H. pylori status, only H. pylori‐positive children with an H. pylori‐negative mother had increased risk of asthma (2.42; 1.11–5.27), accounting for 3.4% of the asthma risk.
Conclusions
Colonisation of a European child with a CagA‐negative‐H. pylori strain at age 6 was associated with an increased prevalence of asthma, but there was no association for non‐European children. The underlying mechanisms for the observed risk differences require further research.
Background and Purpose
Heteromerization of GPCRs is key to the integration of extracellular signals and the subsequent cell response via several mechanisms including heteromer‐selective ligand ...binding, trafficking and/or downstream signalling. As the lysophosphatidylinositol GPCR 55 (GPR55) has been shown to affect the function of the cannabinoid receptor subtype 2 (CB2 receptor) in human neutrophils, we investigated the possible heteromerization of CB2 receptors with GPR55.
Experimental Approach
The direct interaction of human GPR55 and CB2 receptors heterologously expressed in HEK293 cells was assessed by co‐immunoprecipitation and bioluminescence resonance energy transfer assays. The effect of cross‐talk on signalling was investigated at downstream levels by label‐free real‐time methods (Epic dynamic mass redistribution and CellKey impedance assays), ERK1/2‐MAPK activation and gene reporter assays.
Key Results
GPR55 and CB2 receptors co‐localized on the surface of HEK293 cells, co‐precipitated in membrane extracts and formed heteromers in living HEK293 cells. Whereas heteromerization led to a reduction in GPR55‐mediated activation of transcription factors (nuclear factor of activated T‐cells, NF‐κB and cAMP response element), ERK1/2‐MAPK activation was potentiated in the presence of CB2 receptors. CB2 receptor‐mediated signalling was also affected by co‐expression with GPR55. Label‐free assays confirmed cross‐talk between the two receptors.
Conclusions and Implications
Heteromers, unique signalling units, form in HEK293 cells expressing GPR55 and CB2 receptors. The signalling by agonists of either receptor was governed (i) by the presence or absence of the partner receptors (with the consequent formation of heteromers) and (ii) by the activation state of the partner receptor.
Methods to predict numbers of healthy oocytes in the ovaries of young adults could have important diagnostic relevance in family planning and animal agriculture. We have observed that peak antral ...follicle count (AFC) determined by serial ovarian ultrasonography during follicular waves is very highly reproducible within individual young adult cattle, despite 7-fold variation among animals. Herein, we tested the hypothesis that AFC is positively associated with the number of morphologically healthy oocytes and follicles in ovaries and with serum concentrations of anti-Müllerian hormone (AMH), an indirect marker for number of healthy follicles and oocytes in ovaries. In the present study, age-matched young adult cattle (12-18 mo old) were subjected to serial ultrasonography to identify animals with a consistently high (greater-than-or-equal25 follicles that were greater-than-or-equal3 mm in diameter) or low (less-than or equal to15 follicles) AFC during follicular waves. Differences in serum AMH concentrations, ovary weight, and number of morphologically healthy and atretic follicles and oocytes were determined. The phenotypic classifications of cattle based on AFC during follicular waves or AMH concentrations both predict reliably the relative number of morphologically healthy follicles and oocytes in ovaries of age-matched young adult cattle.
Multiple Helicobacter pylori strains may colonize an individual host. Using enzyme-linked immunosorbent assay and line probe assay (LiPA) techniques, we analyzed the prevalence of mixed H. pylori ...colonization in 127 subjects from Venezuela, a country of high H. pylori prevalence, from three regions representing different population groups: the Andes (Merida), where Caucasian mestizos predominate, a major city near the coast (Caracas), where Amerindian-Caucasian-African mestizos predominate, and an Amazonian community (Puerto Ayacucho), where Amerindians predominate and mestizos reflect Amerindian and Caucasian ancestry. Among 121 H. pylori-positive persons, the prevalence of cagA-positive strains varied from 50% (Merida) to 86% (Puerto Ayacucho) by LiPA. Rates of mixed colonization also varied, as assessed by LiPA of the vacA s (mean, 49%) and m (mean, 26%) regions. In total, 55% of the individuals had genotypic evidence of mixed colonization. vacA s1c, a marker of Amerindian (East Asian) origin, was present in all three populations, especially from Puerto Ayacucho (86%). These results demonstrate the high prevalence of mixed colonization and indicate that the H. pylori East Asian vacA genotype has survived in all three populations tested.
The seroprevalence of Helicobacter pylori infection was examined in the adult US population and among different ethnic groups. Stored sera from 7465 adult participants in the first phase of the third ...National Health and Nutritional Examination Survey (1988–1991) were tested with a sensitive and specific IgG ELISA, to diagnose infection. Seroprevalence of H. pylori among all participants was 32.5%. This increased with age, from 16.7% for persons 20–29 years old to 56.9% for those ⩾70 years old. Age-adjusted prevalence was substantially higher among non-Hispanic blacks (52.7%) and Mexican Americans (61.6%) than among non-Hispanic whites (26.2%). After controlling for age and other associated factors, the odds ratios relative to non-Hispanic whites decreased for non-Hispanic blacks, from 3.9 (95% confidence interval CI, 3.1–4.9) to 3.3 (95% CI, 2.6–4.2), and for Mexican Americans, from 6.3 (95% CI, 4.8–8.3) to 2.3 (95% CI, 1.6–3.5). The high prevalence of H. pylori infection among non-Hispanic blacks and Mexican Americans is partially explained by other factors associated with infection.
Detection of SARS-CoV-2 has created an enormous workload for laboratories worldwide resulting in a restriction at the time of massive testing. Pool testing is a strategy that reduces time and costs. ...However, beyond the detection of infectious diseases in blood banks, this approach is rarely implemented in routine laboratories. Therefore, what was learned from the SARS-CoV-2 pool testing should represent an opportunity to increase diagnostic capabilities. The present work, carried out in the context of a diagnostic laboratory of a public hospital during the COVID-19 pandemic, represents a contribution to this end. The main limitation of pool testing is the risk of false negatives that could have been identified by individual tests. These limitations are the dilution of samples with a low virus load during pooling and that the integrity of the sample may be affected by the quality of the sample collection. Fortunately, both limitations coincide with the main strengths of droplet digital PCR (ddPCR). ddPCR is a third-generation PCR that splits the amplification into thousands of droplets that work in parallel, increasing sensitivity and resistance to inhibitors. Therefore, ddPCR is particularly useful for pool testing. Here we show how to factor between test sensitivity and savings in test time and resources. We have identified and optimized critical parameters for pool testing. The present study, which analyzed 1000 nasopharyngeal samples, showed that the pool testing could detect even a single positive sample with a CT value of up to 30 in pools of 34 samples. This test was performed using three different standard extraction methods, the simplest being heating only, which resulted in substantial savings of extraction reagents in addition to PCR reagents. Moreover, we show that pooling can be extended to use saliva, which is less invasive and allows self-collection, reducing the risk for health personnel.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Plasmids are nucleic acid molecules that can drive their own replication in a living cell. They can be transmitted horizontally and can thrive in the host cell to high‐copy numbers. Plasmid ...replication and gene expression consume cellular resources and cells carrying plasmids incur fitness costs. But many plasmids carry genes that can be beneficial under certain conditions, allowing the cell to endure in the presence of antibiotics, toxins, competitors or parasites. Horizontal transfer of plasmid‐encoded genes can thus instantaneously confer differential adaptation to local or transient selection conditions. This conflict between cellular fitness and plasmid spread sets the scene for multilevel selection processes. We have engineered a system to study the short‐term evolutionary impact of different synonymous versions of a plasmid‐encoded antibiotic resistance gene. Applying experimental evolution under different selection conditions and deep sequencing allowed us to show rapid local adaptation to the presence of antibiotic and to the specific version of the resistance gene transferred. We describe the presence of clonal interference at two different levels: at the within‐cell level, because a single cell can carry several plasmids, and at the between‐cell level, because a bacterial population may contain several clones carrying different plasmids and displaying different fitness in the presence/absence of antibiotic. Understanding the within‐cell and between‐cell dynamics of plasmids after horizontal gene transfer is essential to unravel the dense network of mobile elements underlying the worldwide threat to public health of antibiotic resistance.
To determine whether infection with a Helicobacter pylori strain possessing cagA is associated with an increased risk of development of adenocarcinoma of the stomach, we used a nested case-control ...study based on a cohort of 5443 Japanese-American men in Oahu, Hawaii, who had a physical examination and a phlebotomy during 1967 to 1970. We matched 103 H. pylori-infected men who developed gastric cancer during a 21-year surveillence period with 103 H. pylori-infected men who did not develop gastric cancer and tested stored serum specimens from patients and controls for the presence of serum IgG to the cagA product of H. pylori using an ELISA. The serum IgG assay using a recombinant CagA fragment had a sensitivity of 94.4% and a specificity of 92.5% when used in a clinically defined population; serological results were stable for more than 7 years. For men with antibodies to CagA, the odds ratio of developing gastric cancer was 1.9 (95% confidence interval, 0.9-4.0); for intestinal type cancer of the distal stomach, the odds ratio was 2.3 (95% confidence interval, 1.0-5.2). Age < 72 years and advanced tumor stage at diagnosis were significantly associated with CagA seropositivity. We conclude that infection with a cagA-positive H. pylori strain in comparison with a cagA-negative strain somewhat increases the risk for development of gastric cancer, especially intestinal type affecting the distal stomach.
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