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Crouch Forsyth posted an update 1 year, 6 months ago
In meiosis, DNA double-strand break (DSB) formation by Spo11 initiates recombination and enables chromosome segregation. Numerous factors are required for Spo11 activity, and couple the DSB machinery to the development of a meiosis-specific ‘axis-tethered loop’ chromosome organisation. Through in vitro reconstitution and budding yeast genetics, we here provide architectural insight into the DSB machinery by focussing on a foundational DSB factor, Mer2. We characterise the interaction of Mer2 with the histone reader Spp1, and show that Mer2 directly associates with nucleosomes, likely highlighting a contribution of Mer2 to tethering DSB factors to chromatin. We reveal the biochemical basis of Mer2 association with Hop1, a HORMA domain-containing chromosomal axis factor. Finally, we identify a conserved region within Mer2 crucial for DSB activity, and show that this region of Mer2 interacts with the DSB factor Mre11. In combination with previous work, we establish Mer2 as a keystone of the DSB machinery by bridging key protein complexes involved in the initiation of meiotic recombination.Enterohaemorrhagic Escherichia coli (EHEC) produces Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2). Although stx1 and stx2 were found within the late operons of the Stx-encoding phages (Stx-phages), stx1 could mainly be transcribed from the stx1 promoter (P Stx1), which represents the functional operator-binding site (Fur box) for the transcriptional regulator Fur (ferric uptake regulator), upstream of stx1. In this study, we found that the production of Stx1 by EHEC was affected by oxygen concentration. Increased Stx1 production in the presence of oxygen is dependent on Fur, which is an Fe2+-responsive transcription factor. The intracellular Fe2+ pool was lower under microaerobic conditions than under anaerobic conditions, suggesting that lower Fe2+ availability drove the formation of less Fe2+-Fur, less DNA binding to the P Stx1 region, and an increase in Stx1 production.Introduction. Human adenovirus (HAdV) is an important pathogen in acute respiratory tract infections (ARTIs) and HAdV genotypes are associated with disease severity.Hypothesis. Comparative analyses of clinical features could reveal the severity of different HAdV genotypes in ARTIs.Aim. This study aimed to investigate the molecular epidemiology of HAdV infections and explore the correlations between clinical features and HAdV genotypes.Methodology. A retrospective study was conducted on ARTIs at Beijing Chao-Yang Hospital during the period 2011-2016. A standardized data form was used to record the clinical information. HAdV was detected by FQ-PCR from respiratory specimens, and genotypes were determined by entire hexon gene sequencing.Results. A total of 8044 samples were collected, of which 296 (3.7 %) were HAdV-positive. Patients ≤44 years old were more likely to be positive for HAdV. There were three peak periods of adenoviral infections, with detection rates of 13.03, 9.39 and 10.38 %, respectively. Six HAdV genotypes (HAdV-55, -7, -3, -14, -50, -2) were identified, with HAdV-55 and HAdV-7 being the most prevalent (50.6 and 21.5 %). Compared with HAdV-7 and other types, patients infected with HAdV-55 had a longer duration of fever (P=0.0428). Infections with HAdV-55 and HAdV-7 were more severe compared to those caused by other types, with higher rates of oxygen therapy and mechanical ventilation (P=0.0172 and P=0.0144). All five deaths were caused by HAdV-55.Conclusion. This study describes the epidemiological characteristics of HAdV infections in North China, revealing the higher severity of HAdV-55 and HAdV-7 in ARTIs. Thus, strengthened surveillance of HAdV genotypes is warranted.The family Solemoviridae includes viruses with icosahedral particles (26-34 nm in diameter) assembled on T=3 symmetry with a 4-6 kb positive-sense, monopartite, polycistronic RNA genome. Transmission of members of the genera Sobemovirus and Polemovirus occurs via mechanical wounding, vegetative propagation, insect vectors or abiotically through soil; members of the genera Polerovirus and Enamovirus are transmitted by specific aphids. Most solemoviruses have a narrow host range. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Solemoviridae, which is available at ictv.global/report/solemoviridae.Monocercomonoides exilis is considered the first known eukaryote to completely lack mitochondria. This conclusion is based primarily on a genomic and transcriptomic study which failed to identify any mitochondrial hallmark proteins. However, the available genome assembly has limited contiguity and around 1.5 % of the genome sequence is represented by unknown bases. To improve the contiguity, we re-sequenced the genome and transcriptome of M. exilis using Oxford Nanopore Technology (ONT). The resulting draft genome is assembled in 101 contigs with an N50 value of 1.38 Mbp, almost 20 times higher than the previously published assembly. ETC-159 concentration Using a newly generated ONT transcriptome, we further improve the gene prediction and add high quality untranslated region (UTR) annotations, in which we identify two putative polyadenylation signals present in the 3’UTR regions and characterise the Kozak sequence in the 5’UTR regions. All these improvements are reflected by higher BUSCO genome completeness values. Regardless of an overall more complete genome assembly without missing bases and a better gene prediction, we still failed to identify any mitochondrial hallmark genes, thus further supporting the hypothesis on the absence of mitochondrion.
Morphine independently reduces the expression level of Brain-derived Neurotrophic Factor (BDNF) and Cyclic-AMP Response Element Binding protein (CREB). BDNF and CREB play a vital role in protecting and regulating the proper functioning of neurons. There has not been any study on the effect of methadone maintenance treatment and its comparison with morphine. Therefore, this study was conducted to examine the effect of methadone maintenance on the expression of BDNF and CREB genes in brain VTA of male morphine treated rats.
In this study, 24 Wistar rats (200-250g) were assigned to three experimental groups 1) Animals without morphine treatment (control); 2) Morphine treated animals (10 mg/kg, twice/day through subcutaneous injection for 21 days); 3) Animals under methadone maintenance after treatment with morphine (maintenance dose of methadone was achieved during 14 days equal to 1 mg per 100 ml at the first week and 2.5 mg per 100 ml at second week). To evaluate the expression of BDNF and CREB genes, real time PCR method was used, and ELISA was applied to measure the serum level of BDNF protein at the end of the experiment.
According to the findings of this study, similar to morphine treated group, methadone maintenance in morphine treated animals led to a significant reduction in the expression of BDNF and CREB genes at VTA as well BDNF serum level compared with the control group.
It was concluded that methadone, like morphine, causes a significant reduction in the expression of BDNF and CREB genes in the brain VTA area of rats as well as BDNF serum level compared with the control group.
It was concluded that methadone, like morphine, causes a significant reduction in the expression of BDNF and CREB genes in the brain VTA area of rats as well as BDNF serum level compared with the control group.
Mixed solvents MD simulations have proved to be a useful and increasingly accepted technique with several applications in structure-based drug discovery.
Mixed solvents MD simulations have proved to be a useful and increasingly accepted technique with several applications in structure-based drug discovery Result As such, they are hardly transferable to different molecules.
To achieve transferable energies, we present here a method for decomposing the molecular binding free energy into accurate atomic contributions and we demonstrate with two qualitative visual examples how the corrected energy maps better match known binding hotspots and how they can reveal hidden hotspots with actual drug design potential.
To achieve transferable energies, we present here a method for decomposing the molecular binding free energy into accurate atomic contributions and we demonstrate with two qualitative visual examples how the corrected energy maps better match known binding hotspots and how they can reveal hidden hotspots with actual drug design potential.Homocysteine (Hcy) is an important intermediate in methionine metabolism and generation of one-carbon unit, and its dysfunction is associated with many pathological states. Although Hcy is a non-protein amino acid, many studies have demonstrated protein-related homocysteine metabolism and possible mechanisms underlying homocysteinylation. Homocysteinylated proteins lose their original biological function and have a negative effect on the various disease phenotypes. Hydrogen sulfide (H2S) has been recognized as an important gaseous signaling molecule with mounting physiological properties. H2S modifies small molecules and proteins via sulfhydration, which is supposed to be essential in the regulation of biological functions and signal transduction in human health and disorders. This review briefly introduces Hcy and H2S, further discusses pathophysiological consequences of homocysteine modification and sulfhydryl modification, and ultimately makes a prediction that H2S might exert a protective effect on the toxicity of homocysteinylation of target protein via sulfhydration. The highlighted information here yields new insights for the role of protein modification by Hcy and H2S in diseases.Alzheimer’s disease (AD), the most common form of dementia, is pathologically characterized by the deposition of amyloid-β plaques and the formation of neurofibrillary tangles. In a neurodegenerative brain, glucose metabolism is also impaired and considered as one of the key features in AD patients. The impairment causes a reduction in glucose transporters and the uptake of glucose as well as alterations in the specific activity of glycolytic enzymes. Recently, it has been reported that α-amylase, a polysaccharide-degrading enzyme, is present in the human brain. The enzyme is known to be associated with various diseases such as type 2 diabetes mellitus and hyperamylasaemia. With this information at hand, we hypothesize that α-amylase could have a vital role in the demented brains of AD patients. This review aims to shed insight into the possible link between the expression levels of α-amylase and AD. Lastly, we also cover the diverse role of amylase inhibitors and how they could serve as a therapeutic agent to manage or stop AD progression.
Polytherapy and the anticholinergic activity of several drugs negatively influence cognition in the elderly. However, little is known on the effect on Mild Cognitive Impairment (MCI) in Parkinson’s Disease (PD).
Patients with PD belonging to the baseline PACOS cohort with full pharmacological data, have been included in this study. MCI diagnosis was made according to the MDS level II criteria. Polytherapy was defined as patients assuming ≥6 drugs. Anticholinergic burden has been calculated using the Anticholinergic Drug Scale (ADS). Molecules have been classified according to the ATC classification. Association with MCI has been assessed with a multivariate logistic regression analysis with MCI as the dependent variable.
Pharmacological data was available for 238 patients (mean age 64.7±9.7). One hundred (42.0%) were diagnosed as MCI. In the full multivariate model (correcting for age, sex, disease duration, education, UPDRS-ME, LEDD-DAs) no association was found with either polytherapy or the ADS. Concerning drug classes, anti-hypertensive medications increased the risk of PD-MCI (OR 2.
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