Search results for "General Immunology and Microbiology"
showing 10 items of 784 documents
Uncoupling of dynamin polymerization and GTPase activity revealed by the conformation-specific nanobody dynab
2017
Dynamin is a large GTPase that forms a helical collar at the neck of endocytic pits, and catalyzes membrane fission (Schmid and Frolov, 2011; Ferguson and De Camilli, 2012). Dynamin fission reaction is strictly dependent on GTP hydrolysis, but how fission is mediated is still debated (Antonny et al., 2016): GTP energy could be spent in membrane constriction required for fission, or in disassembly of the dynamin polymer to trigger fission. To follow dynamin GTP hydrolysis at endocytic pits, we generated a conformation-specific nanobody called dynab, that binds preferentially to the GTP hydrolytic state of dynamin-1. Dynab allowed us to follow the GTPase activity of dynamin-1 in real-time. We…
Kinematic Sub-Populations in Bull Spermatozoa: A Comparison of Classical and Bayesian Approaches
2020
The ejaculate is heterogenous and sperm sub-populations with different kinematic patterns can be identified in various species. Nevertheless, although these sub-populations are statistically well defined, the statistical differences are not always relevant. The aim of the present study was to characterize kinematic sub-populations in sperm from two bovine species, and diluted with different commercial extenders, and to determine the statistical relevance of sub-populations through Bayesian analysis. Semen from 10 bulls was evaluated after thawing. An ISAS®
Optimized production and purification of Coxsackievirus B1 vaccine and its preclinical evaluation in a mouse model.
2017
Coxsackie B viruses are among the most common enteroviruses, causing a wide range of diseases. Recent studies have also suggested that they may contribute to the development of type 1 diabetes. Vaccination would provide an effective way to prevent CVB infections, and the objective of this study was to develop an efficient vaccine production protocol for the generation of novel CVB vaccines. Various steps in the production of a formalin-inactivated Coxsackievirus B1 (CVB1) vaccine were optimized including the Multiplicity Of Infection (MOI) used for virus amplification, virus cultivation time, type of cell growth medium, virus purification method and formulation of the purified virus. Safety…
Cortex-wide BOLD fMRI activity reflects locally-recorded slow oscillation-associated calcium waves.
2017
When a person is in a deep non-dreaming sleep, neurons in their brain alternate slowly between periods of silence and periods of activity. This gives rise to low-frequency brain rhythms called slow waves, which are thought to help stabilize memories. Slow wave activity can be detected on multiple scales, from the pattern of electrical impulses sent by an individual neuron to the collective activity of the brain’s entire outer layer, the cortex. But does slow wave activity in an individual group of neurons in the cortex affect the activity of the rest of the brain? To find out, Schwalm, Schmid, Wachsmuth et al. took advantage of the fact that slow waves also occur under general anesthesia, a…
Tracking zoonotic pathogens using blood-sucking flies as 'flying syringes'
2017
About 60% of emerging infectious diseases in humans are of zoonotic origin. Their increasing number requires the development of new methods for early detection and monitoring of infectious agents in wildlife. Here, we investigated whether blood meals from hematophagous flies could be used to identify the infectious agents circulating in wild vertebrates. To this aim, 1230 blood-engorged flies were caught in the forests of Gabon. Identified blood meals (30%) were from 20 vertebrate species including mammals, birds and reptiles. Among them, 9% were infected by different extant malaria parasites among which some belonged to known parasite species, others to new parasite species or to parasite …
Phylogenetic variation in cortical layer II immature neuron reservoir of mammals
2020
The adult mammalian brain is mainly composed of mature neurons. A limited amount of stem cell-driven neurogenesis persists in postnatal life and is reduced in large-brained species. Another source of immature neurons in adult brains is cortical layer II. These cortical immature neurons (cINs) retain developmentally undifferentiated states in adulthood, though they are generated before birth. Here, the occurrence, distribution and cellular features of cINs were systematically studied in 12 diverse mammalian species spanning from small-lissencephalic to large-gyrencephalic brains. In spite of well-preserved morphological and molecular features, the distribution of cINs was highly heterogeneou…
Introducing Clicker Training as a Cognitive Enrichment for Laboratory Mice
2017
Establishing new refinement strategies in laboratory animal science is a central goal in fulfilling the requirements of Directive 2010/63/EU. Previous research determined a profound impact of gentle handling protocols on the well-being of laboratory mice. By introducing clicker training to the keeping of mice, not only do we promote the amicable treatment of mice, but we also enable them to experience cognitive enrichment. Clicker training is a form of positive reinforcement training using a conditioned secondary reinforcer, the "click" sound of a clicker, which serves as a time bridge between the strengthened behavior and an upcoming reward. The effective implementation of the clicker trai…
Citations and metrics of journals discontinued from Scopus for publication concerns: the GhoS(t)copus Project
2020
Background: Scopus is a leading bibliometric database. It contains a large part of the articles cited in peer-reviewed publications. The journals included in Scopus are periodically re-evaluated to ensure they meet indexing criteria and some journals might be discontinued for 'publication concerns'. Previously published articles may remain indexed and can be cited. Their metrics have yet to be studied. This study aimed to evaluate the main features and metrics of journals discontinued from Scopus for publication concerns, before and after their discontinuation, and to determine the extent of predatory journals among the discontinued journals. Methods: We surveyed the list of discontinued jo…
What Healthcare Workers Should Know about Environmental Bacterial Contamination in the Intensive Care Unit
2017
Intensive care unit- (ICU-) acquired infections are a major health problem worldwide. Inanimate surfaces and equipment contamination may play a role in cross-transmission of pathogens and subsequent patient colonization or infection. Bacteria contaminate inanimate surfaces and equipment of the patient zone and healthcare area, generating a reservoir of potential pathogens, including multidrug resistant species. Traditional terminal cleaning methods have limitations. Indeed patients who receive a bed from prior patient carrying bacteria are exposed to an increased risk (odds ratio 2.13, 95% confidence intervals 1.62–2.81) of being colonized and potentially infected by the same bacterial spec…
Impact of freeze-thaw cytoablation on aqueous outflow patterns in ex vivo anterior chamber perfusion cultures and whole eyes
2022
Background: Porcine eyes have been widely used as ex vivo models in glaucoma research, as they share similar features with human eyes. Freeze-thawing is a non-invasive technique that has been used to obliterate living cells in anterior segment ex vivo cultures, to prepare them for further research such as cellular repopulation. This technique has previously been shown to reduce the intraocular pressure (IOP) in porcine eyes. The aim of this study was to investigate whether freeze-thaw cytoablation causes corresponding canalogram outflow changes in perfused anterior segment cultures (AFT) and whole porcine eyes (WFT). We hypothesized that the known IOP drop in AFT after trabecular meshwork a…