Powerful as well as cellspecific carry networks for intracellular birdwatcher ions
Therefore, scaling of cyclin-CDK levels with cell size, CDK inhibitory phosphorylation, PP2A, and DNA-dependent inhibition of CDK activity, all inform the cell cycle network of cell size, thus contributing to cell size homeostasis.During HIV-1 particle formation, the requisite plasma membrane curvature is thought to be solely driven by the retroviral Gag protein. Here, we reveal that the cellular I-BAR protein IRSp53 is required for the progression of HIV-1 membrane curvature to complete particle assembly. siRNA-mediated knockdown of IRSp53 gene expression induces a decrease in viral particle production and a viral bud arrest at half completion. Single-molecule localization microscopy at the cell plasma membrane shows a preferential localization of IRSp53 around HIV-1 Gag assembly sites. Tanzisertib mouse In addition, we observe the presence of IRSp53 in purified HIV-1 particles. Finally, HIV-1 Gag protein preferentially localizes to curved membranes induced by IRSp53 I-BAR domain on giant unilamellar vesicles. Overall, our data reveal a strong interplay between IRSp53 I-BAR and Gag at membranes during virus assembly. This highlights IRSp53 as a crucial host factor in HIV-1 membrane curvature and its requirement for full HIV-1 particle assembly.Most female meiotic spindles undergo striking morphological changes while transitioning from metaphase to anaphase. The ultra-structure of meiotic spindles, and how changes to this structure correlate with such dramatic spindle rearrangements remains largely unknown. To address this, we applied light microscopy, large-scale electron tomography and mathematical modeling of female meiotic Caenorhabditis elegans spindles. Combining these approaches, we find that meiotic spindles are dynamic arrays of short microtubules that turn over within seconds. The results show that the metaphase to anaphase transition correlates with an increase in microtubule numbers and a decrease in their average length. Detailed analysis of the tomographic data revealed that the microtubule length changes significantly during the metaphase-to-anaphase transition. This effect is most pronounced for microtubules located within 150 nm of the chromosome surface. To understand the mechanisms that drive this transition, we developed a mathematical model for the microtubule length distribution that considers microtubule growth, catastrophe, and severing. Using Bayesian inference to compare model predictions and data, we find that microtubule turn-over is the major driver of the spindle reorganizations. Our data suggest that in metaphase only a minor fraction of microtubules, those closest to the chromosomes, are severed. The large majority of microtubules, which are not in close contact with chromosomes, do not undergo severing. Instead, their length distribution is fully explained by growth and catastrophe. This suggests that the most prominent drivers of spindle rearrangements are changes in nucleation and catastrophe rate. In addition, we provide evidence that microtubule severing is dependent on katanin.Clostridioides difficile infection (CDI) remains an urgent global One Health threat. The genetic heterogeneity seen across C. difficile underscores its wide ecological versatility and has driven the significant changes in CDI epidemiology seen in the last 20 years. We analysed an international collection of over 12,000 C. difficile genomes spanning the eight currently defined phylogenetic clades. Through whole-genome average nucleotide identity, and pangenomic and Bayesian analyses, we identified major taxonomic incoherence with clear species boundaries for each of the recently described cryptic clades CI-III. The emergence of these three novel genomospecies predates clades C1-5 by millions of years, rewriting the global population structure of C. difficile specifically and taxonomy of the Peptostreptococcaceae in general. These genomospecies all show unique and highly divergent toxin gene architecture, advancing our understanding of the evolution of C. difficile and close relatives. Beyond the taxonomic ramifications, this work may impact the diagnosis of CDI.A tightly regulated innate immune response to trypanosome infections is critical to strike a balance between parasite control and inflammation-associated pathology. In this study, we make use of the recently established Trypanosoma carassii infection model in larval zebrafish to study the early response of macrophages and neutrophils to trypanosome infections in vivo. We consistently identified high- and low-infected individuals and were able to simultaneously characterise their differential innate response. Not only did macrophage and neutrophil number and distribution differ between the two groups, but also macrophage morphology and activation state. Exclusive to high-infected zebrafish, was the occurrence of foamy macrophages characterised by a strong pro-inflammatory profile and potentially associated with an exacerbated immune response as well as susceptibility to the infection. To our knowledge, this is the first report of the occurrence of foamy macrophages during an extracellular trypanosome infection.For a more complete understanding of molecular mechanisms, it is important to study macromolecules and their assemblies in the broader context of the cell. This context can be visualized at nanometer resolution in three dimensions (3D) using electron cryo-tomography, which requires tilt series to be recorded and computationally aligned, currently limiting throughput. Additionally, the high-resolution signal preserved in the raw tomograms is currently limited by a number of technical difficulties, leading to an increased false-positive detection rate when using 3D template matching to find molecular complexes in tomograms. We have recently described a 2D template matching approach that addresses these issues by including high-resolution signal preserved in single-tilt images. A current limitation of this approach is the high computational cost that limits throughput. We describe here a GPU-accelerated implementation of 2D template matching in the image processing software cisTEM that allows for easy scaling and improves the accessibility of this approach. We apply 2D template matching to identify ribosomes in images of frozen-hydrated Mycoplasma pneumoniae cells with high precision and sensitivity, demonstrating that this is a versatile tool for in situ visual proteomics and in situ structure determination. We benchmark the results with 3D template matching of tomograms acquired on identical sample locations and identify strengths and weaknesses of both techniques, which offer complementary information about target localization and identity.
Appendectomy is the gold standard for treatment of acute appendicitis. However, recent studies favor primary antibiotic therapy. The aim of this observational study was to explore changes in the numbers of operations for acute appendicitis in the period 2010-2017, paying special attention to disease severity.
Data from diagnosis-related group statistics were used to analyze the trends, mortality, and complication rates in the surgical treatment of appendicitis in Germany between 2010 and 2017. All cases of appendectomy after a diagnosis of appendicitis were included.
Altogether, 865 688 inpatient cases were analyzed. The number of appendectomies went down by 9,8%, from 113 614 in 2010 to 102 464 in 2017, while the incidence fell from 139/100 000 in 2010 to 123/100 000 in 2017 (standardized by age group). This decrease is due to the lower number of operations for uncomplicated appendicitis (79 906 in 2017 versus 93 135 in 2010). Hospital mortality decreased both in patients who underwent surgical treatment of complicated appendicitis (0.62% in 2010 versus 0.42% in 2017) and in those with a complicated clinical course (5.4% in 2010 versus 3.4% in 2017).
Decisions on the treatment of acute appendicitis in German hospitals follow the current trend towards non-surgical management in selected patients. At the same time, the care of acute appendicitis has improved with regard to overall hospital morbidity and hospital mortality.
Decisions on the treatment of acute appendicitis in German hospitals follow the current trend towards non-surgical management in selected patients. At the same time, the care of acute appendicitis has improved with regard to overall hospital morbidity and hospital mortality.
The increasing use of cranial tomographic imaging has led to the more frequent discovery of pituitary tumors. In this review, we discuss the clinical symptoms that point toward a pituitary tumor, the required diagnostic studies, the potential need for follow-up studies, and the indications for neurosurgical treatment.
This review is based on pertinent publications from the years 2005-2020 that were retrieved by a selective search in PubMed, as well as on the current German S2k guideline, which was created with the present authors playing a coordinating role, and on further guidelines from abroad. Relevant information from older reviews was also considered.
The reported prevalence of pituitary tumors varies depending on the method of data acquisition. Autopsy studies yield a figure of 10.7%, while population-based studies reported 77.6-115.6 cases per 100 000 inhabitants. These lesions are nearly always benign, and 85% of them are pituitary adenomas. Pituitary adenomas measuring less than 1 cm in diameteclear indications for surgery, e.g., imminent loss of vision, but most asymptomatic pituitary tumors can be observed only.
The manifestations of pituitary tumors are first recognized by primary care physicians. The further diagnostic evaluation of these patients should be carried out in standardized and interdisciplinary fashion.
The manifestations of pituitary tumors are first recognized by primary care physicians. The further diagnostic evaluation of these patients should be carried out in standardized and interdisciplinary fashion.
Vaccination during pregnancy can protect both the expecting mother and the unborn and newborn child from infectious diseases.
This review is based on publications retrieved by a selective literature search on the immunological particularities of infectious diseases affecting pregnant women, unborn children, and neonates, with particular attention to the guidelines of the German Standing Committee on Vaccinations (Ständige Impfkommission, STIKO) and the pertinent guidelines.
Vaccination during pregnancy protects the expecting mother from a severe course of a number of different infectious diseases. Vaccination with inactivated vaccines against influenza, tetanus, and pertussis is effective, safe, and well tolerated. Women who are pregnant or of child-bearing age should be immunized against tetanus according to the STIKO recommendations. All pregnant women from the second trimester onward should receive an inactivated quadrivalent influenza vaccine. The immunity acquired after vaccination with an acellulamune protection against life-threatening infections by the vertical transmission of maternal antibodies until they are able to build up their own adaptive immunity.
A decline in the number of patients presenting with myocardial infarction was reported from the beginning of the COVID-19 pandemic onward. It is thought that measures introduced to stem the pandemic, such as the lockdown, contributed to this development. There are, however, conflicting data with respect to hospital referrals, delay times, and mortality.
Our systematic literature review and meta-analysis included studies reporting the number of hospital referrals of patients with ST-segment-elevation myocardial infarction (STEMI) and/or non-ST-segment-elevation myocardial infarction (NSTEMI) during lockdown episodes. We also collected data on delays caused by patient and system delay times, as well as on mortality.
Data from 27 studies on a total of 81 163 patients were included in our meta-analysis. We found that the number of hospital admissions with myocardial infarction was significantly lower during the lockdown than before the pandemic (incidence rate ratio [IRR] = 0.516, 95% CI [0.403; 0.660], I2 = 98%).