The heterozygosity status of polymorphic elements of the immune system, such as the major histocompatibility complex (MHC), is known to increase the potential to cope with a wider variety of ...pathogens. Pre‐ and postcopulatory processes may regulate MHC heterozygosity. In a population where mating occurs among individuals that share identical MHC haplotypes, postcopulatory selection may disfavour homozygous offspring or ones with two MHC haplotypes identical to its mother. We tested these ideas by determining the incidence of MHC‐heterozygous and MHC‐homozygous individuals in a pedigreed, partially consanguineous captive rhesus monkey colony. Bayesian statistics showed that when parents share MHC haplotypes, the distribution of MHC‐heterozygous and MHC‐homozygous individuals significantly fitted the expected Mendelian distribution, both for the complete MHC haplotypes, and for MHC class I or II genes separately. Altogether, we found in this captive colony no evidence for postcopulatory selection against MHC‐homozygous individuals. However, the distribution of paternally and maternally inherited MHC haplotypes tended to differ significantly from expected. Individuals with two MHC haplotypes identical to their mother were underrepresented and offspring with MHC haplotypes identical to their father tended to be overrepresented. This suggests that postcopulatory processes affect MHC haplotype combination in offspring, but do not prevent low MHC heterozygosity.
The bacterial species Staphylococcus aureus, including its methicillin-resistant variant (MRSA), finds its primary ecological niche in the human nose, but is also able to colonize the intestines and ...the perineal region. Intestinal carriage has not been widely investigated despite its potential clinical impact. This review summarizes literature on the topic and sketches the current state of affairs from a microbiological and infectious diseases' perspective. Major findings are that the average reported detection rate of intestinal carriage in healthy individuals and patients is 20% for S. aureus and 9% for MRSA, which is approximately half of that for nasal carriage. Nasal carriage seems to predispose to intestinal carriage, but sole intestinal carriage occurs relatively frequently and is observed in 1 out of 3 intestinal carriers, which provides a rationale to include intestinal screening for surveillance or in outbreak settings. Colonization of the intestinal tract with S. aureus at a young age occurs at a high frequency and may affect the host's immune system. The frequency of intestinal carriage is generally underestimated and may significantly contribute to bacterial dissemination and subsequent risk of infections. Whether intestinal rather than nasal S. aureus carriage is a primary predictor for infections is still ill-defined.
Summary
Background
It has been suggested that patients presenting with upper gastrointestinal bleeding (UGIB) during the weekend have a worse outcome compared with weekdays, with an increased risk of ...recurrent bleeding and mortality.
Aim
To investigate the association between timing of admission and adverse outcome after UGIB.
Methods
We prospectively collected data from patients presenting with symptoms suggestive of UGIB to the emergency room of eight participating hospitals. Using standard descriptive statistics and logistic regression analyses, differences in 30‐day mortality, rebleeding rate, and need for angiography and surgical intervention were assessed for week‐ and weekend admissions and time of admission. Moreover, patient‐ and procedure‐related factors were identified that could influence outcome.
Results
In total, 571 patients were included with suspected UGIB. Patient admitted during the weekend had a higher mortality rate than patients admitted during the week 9% vs.3%; adjusted odds ratio 2.68 (95%CI 1.07–6.72). Weekend admissions were not associated with other adverse outcomes. Patients admitted during the weekend presented more often with bleeding and had a significantly lower systolic and diastolic blood pressure. No differences were found in procedure‐related factors. Time of admission was not associated with an adverse outcome, although patients admitted during the evening had a significantly longer time to endoscopy (15, 22 and 16 h for day, evening and night admissions respectively, P < 0.01).
Conclusion
Although quality of care did not appear to differ between week/weekend admissions, patients with suspected upper gastrointestinal bleeding admitted during the weekend were at higher risk of an adverse outcome. This might be due to the fact that these patients have more severe haemorrhage.
We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 ...and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed.
RNA-binding proteins are key regulators of post-transcriptional processes such as alternative splicing and mRNA stabilization. Rbm24 acts as a regulator of alternative splicing in heart and skeletal ...muscle, and is essential for sarcomere assembly. Homozygous inactivation of Rbm24 in mice disrupts cardiac development and results in embryonic lethality around E12.5. In the present study, we generated somatic Rbm24 knockout (KO) mice and investigated the effects of reduced levels of Rbm24 in the adult heart. Due to the embryonic lethality of Rbm24 KO mice, we examined cardiac structure and function in adult Rbm24 heterozygotes (HETs). Rbm24 protein expression was 40% downregulated in HET hearts compared to WT hearts. Force measurements on isolated membrane-permeabilized myocytes showed increased sarcomere slack length and lower myofilament passive stiffness in adult Rbm24 HET compared to wildtype cardiomyocytes. As a result of the differences in sarcomere slack length, the relations between force development and sarcomere length differed between WT and Rbm24 HET hearts. No differences in sarcomere structure and titin isoform composition were observed. Likewise, in vivo cardiac function and myocardial structure was unaltered in Rbm24 HET mice compared to WT, at baseline and upon pressure overload after transverse aortic constriction. In conclusion, we generated a somatic Rbm24 KO model and recapitulated the previously reported embryonic phenotype. In adult Rbm24 HET cardiomyocytes we observed increased sarcomere slack length, but no difference in sarcomere structure and cardiac function.
Several algorithms predicting outcomes in acute gastrointestinal bleeding have been developed over the past three decades. These algorithms differ substantially and therefore the aim of the current ...study was to conduct a systematic review to compare their predictive performance and methodological quality in gastrointestinal bleeding.
A PubMed literature search was performed up to 1 July 2011. All studies reporting prediction scores in gastrointestinal bleeding were included. Studies were analyzed for predictive performance, and a quality appraisal of these rules was performed for which a score range of 0 (lowest) to 29 (highest) was used.
A total of 372 studies were identified, of which 16 were eligible for inclusion. The studies evaluated different outcomes: mortality (n = 5), rebleeding (n = 2), intervention required (n = 2), or a combination (n = 7). The predictive performance of the identified prediction scores varied between an area under the curve of 0.71 - 0.92 (if given). The mean overall quality rating was 17 (SD 4.0, range 9 - 25). Major methodological shortcomings were the absence of validation and absence of impact analyses. Eight of 16 scores (50 %) were determined "easy to use," and five scores (31 %) reported some type of action based on the results.
Substantial heterogeneity in outcomes and results was seen in the 16 identified prediction scores. Moreover, the methodological quality was suboptimal in most studies. However, we suggest that clinicians should use the "best available" scores according to performance and quality, which are the Blatchford score to assess the need for intervention, and the scores of Villanueva et al. for poor outcome, Guglielmi et al. for rebleeding, and Chiu et al. for mortality risk.
Complete Genome Sequence of Lactobacillus plantarum WCFS1 Kleerebezem, Michiel; Boekhorst, Jos; van Kranenburg, Richard ...
Proceedings of the National Academy of Sciences - PNAS,
02/2003, Letnik:
100, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The 3,308,274-bp sequence of the chromosome of Lactobacillus plantarum strain WCFS1, a single colony isolate of strain NCIMB8826 that was originally isolated from human saliva, has been determined, ...and contains 3,052 predicted protein-encoding genes. Putative biological functions could be assigned to 2,120 (70%) of the predicted proteins. Consistent with the classification of L. plantarum as a facultative heterofermentative lactic acid bacterium, the genome encodes all enzymes required for the glycolysis and phosphoketolase pathways, all of which appear to belong to the class of potentially highly expressed genes in this organism, as was evident from the codon-adaptation index of individual genes. Moreover, L. plantarum encodes a large pyruvate-dissipating potential, leading to various end-products of fermentation. L. plantarum is a species that is encountered in many different environmental niches, and this flexible and adaptive behavior is reflected by the relatively large number of regulatory and transport functions, including 25 complete PTS sugar transport systems. Moreover, the chromosome encodes >200 extracellular proteins, many of which are predicted to be bound to the cell envelope. A large proportion of the genes encoding sugar transport and utilization, as well as genes encoding extracellular functions, appear to be clustered in a 600-kb region near the origin of replication. Many of these genes display deviation of nucleotide composition, consistent with a foreign origin. These findings suggest that these genes, which provide an important part of the interaction of L. plantarum with its environment, form a lifestyle adaptation region in the chromosome.
The synthesis of large, defect-free two-dimensional materials (2DMs) such as graphene is a major challenge toward industrial applications. Chemical vapor deposition (CVD) on liquid metal catalysts ...(LMCats) is a recently developed process for the fast synthesis of high-quality single crystals of 2DMs. However, up to now, the lack of in situ techniques enabling direct feedback on the growth has limited our understanding of the process dynamics and primarily led to empirical growth recipes. Thus, an in situ multiscale monitoring of the 2DMs structure, coupled with a real-time control of the growth parameters, is necessary for efficient synthesis. Here we report real-time monitoring of graphene growth on liquid copper (at 1370 K under atmospheric pressure CVD conditions) via four complementary in situ methods: synchrotron X-ray diffraction and reflectivity, Raman spectroscopy, and radiation-mode optical microscopy. This has allowed us to control graphene growth parameters such as shape, dispersion, and the hexagonal supra-organization with very high accuracy. Furthermore, the switch from continuous polycrystalline film to the growth of millimeter-sized defect-free single crystals could also be accomplished. The presented results have far-reaching consequences for studying and tailoring 2D material formation processes on LMCats under CVD growth conditions. Finally, the experimental observations are supported by multiscale modeling that has thrown light into the underlying mechanisms of graphene growth.
Abstract Left atrial catheter ablation is an established non-pharmacological therapy for the treatment of atrial fibrillation. The importance of a noninvasive multimodality imaging approach is ...emphasized by the current guidelines for the various phases of the ablation work-up e.g. patient identification, therapy guidance and procedural evaluation. Advances in the capabilities of imaging modalities and the increasing cost of healthcare warrant a review of the multimodality approach. This review discusses the application of cardiac imaging for pulmonary vein and left atrial ablation divided into stages: pre-procedural stage (assessment of left atrial dimensions, left atrial appendage thrombus and pulmonary vein anatomy), peri-procedural stage (integration of anatomical and electrical information) and post-procedural stage (evaluation of efficacy by assessment of tissue properties). Each section is dedicated to one of the subtopics of a stage, allowing a thorough comparison to be made between the strengths and weaknesses of the different imaging modalities and the identification of one that exhibits the potential for a single technique approach.
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