The important role of in-situ simulation in preparing surgeons for the COVID-19 pandemic

BackgroundEffective training is vital when facing viral outbreaks such as the SARS Coronavirus 2 (SARS-CoV-2) outbreak of 2019. The objective of this study was to measure the impact of in-situ simulation on the confidence of the surgical teams of two hospitals in assessing and managing acutely unwell surgical patients who are high-risk or confirmed to have COVID-19.MethodsThis was a quasi-experimental study with a pretest-posttest design. The surgical teams at each hospital participated in multi-disciplinary simulation sessions to explore the assessment and management of a patient requiring emergency surgery who is high risk for COVID-19. The participants were surveyed before and after receiving simulation training to determine their level of confidence on a Visual Analog Scale (VAS) for the premise stated in each of the nine questions in the survey, which represented multiple aspects of the care of these patients.Results27 participants responded the pre-simulation survey and 24 the one post-simulation. The level of confidence (VAS score) were statistically significantly higher for all nine questions after the simulation. Specific themes were identified for further training and changes in policy.ConclusionIn-situ simulation is an effective training method. Its versatility allows it to be set up quickly as rapid-response training in the face of an imminent threat. In this study, it improved the preparedness of two surgical teams for the challenges of the COVID-19 pandemic.     

Variability of tropism and replicative capacity of two naturally occurring influenza A H9N2 viruses in cell cultures from different tissues

Studies carried out on cell permissivity are of great interest to understand virus replication and pathogenicity. We described the results of a comparative analysis of replication efficiency of two naturally occurring influenza A H9N2 variants isolated from poultry and wild birds, differing by only two substitutions Q226L and T384N, in the receptor-binding site of haemagglutinin and the 380 loop region of NA proteins, respectively. Considering the overall growth of both viruses, lung cultures ensured the most efficient growth of TUN12L226N384 strain with titres up to 10⁹ TCID₅₀/ml whereas small intestine culture was highly susceptible to the TUN51Q226T384 virus reaching a titre of 10⁶ TCID50/ml. The lowest replication was shown in liver cells. The addition of trypsin was essential for the replication of either virus in primary fibroblasts, but it had a marginal positive effect on virus replication in the four other culture types with maximum titres of 10⁸ TCID₅₀/ml. This means that in chicken, the proteolytic activation of the H9N2 viruses with the cleavage motif RSSR may be mediated by other endoproteases than trypsin. Further investigations should concentrate on the production of the appropriate set of viruses by a reverse genetics approach and the examination of cellular protease expression in chicken tissues. This would lead to a more complete understanding of the tropism of low-pathogenic Influenza A viruses.     

A druggable addiction to de novo pyrimidine biosynthesis in diffuse midline glioma

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A patient with fever,abdominal pain and bicytopenia: Trouble once again with these IgM antibodies!

We here report the case of a 30-year old man with a history of ulcerative colitis, who presented clinical and biological features compatible with a viral hepatitis. Initial serological results revealed the presence of IgM antibodies against many viruses, and the most likely diagnosis was viral hepatitis A. However, further investigations were performed and concluded to cytomegalovirus primary infection.     

Neuropeptides in epilepsy

Neuropeptides play an important role in modulating seizures and epilepsy. Unlike neurotransmitters which operate on a millisecond time-scale, neuropeptides have longer half lives; this leads to modulation of neuronal and network activity over prolonged periods, so contributing to setting the seizure threshold. Most neuropeptides are stored in large dense vesicles and co-localize with inhibitory interneurons. They are released upon high frequency stimulation making them attractive targets for modulation of seizures, during which high frequency discharges occur. Numerous neuropeptides have been implicated in epilepsy; one, ACTH, is already used in clinical practice to suppress seizures. Here, we concentrate on neuropeptides that have a direct effect on seizures, and for which therapeutic interventions are being developed. We have thus reviewed the abundant reports that support a role for neuropeptide Y (NPY), galanin, ghrelin, somatostatin and dynorphin in suppressing seizures and epileptogenesis, and for tachykinins having pro-epileptic effects. Most in vitro and in vivo studies are performed in hippocampal tissue in which receptor expression is usually high, making translation to other brain areas less clear. We highlight recent therapeutic strategies to treat epilepsy with neuropeptides, which are based on viral vector technology, and outline how such interventions need to be refined in order to address human disease.     

Nucleostemin deletion reveals an essential mechanism that maintains the genomic stability of stem and progenitor cells

Stem and progenitor cells maintain a robust DNA replication program during the tissue expansion phase of embryogenesis. The unique mechanism that protects them from the increased risk of replication-induced DNA damage, and hence permits self-renewal, remains unclear. To determine whether the genome integrity of stem/progenitor cells is safeguarded by mechanisms involving molecules beyond the core DNA repair machinery, we created a nucleostemin (a stem and cancer cell-enriched protein) conditional-null allele and showed that neural-specific knockout of nucleostemin predisposes embryos to spontaneous DNA damage that leads to severe brain defects in vivo. In cultured neural stem cells, depletion of nucleostemin triggers replication-dependent DNA damage and perturbs self-renewal, whereas overexpression of nucleostemin shows a protective effect against hydroxyurea-induced DNA damage. Mechanistic studies performed in mouse embryonic fibroblast cells showed that loss of nucleostemin triggers DNA damage and growth arrest independently of the p53 status or rRNA synthesis. Instead, nucleostemin is directly recruited to DNA damage sites and regulates the recruitment of the core repair protein, RAD51, to hydroxyurea-induced foci. This work establishes the primary function of nucleostemin in maintaining the genomic stability of actively dividing stem/progenitor cells by promoting the recruitment of RAD51 to stalled replication-induced DNA damage foci.     

Update on the Human Immunodeficiency Virus

At the end of 2011, UNAIDS estimated that 34 million (31.4 to 35.9) individuals were infected by HIV worldwide and that 2.5 million were newly infected during the year. Since 2001, we have observed an increased number of HIV-infected patients in the world, due to an expanded access to antiretroviral drugs. More than 23,5 million (22.1 to 24.8) HIV-infected patients live in Sub-Saharan Africa. The number of HIV-infected patients in France is estimated at 152,000. Two types of HIV cause AIDS: HIV-1 and HIV-2 that are subdivided in groups (M, N, O, P for HIV-1; A to H for HIV-2), subtypes (A-D, F-H, J-K for HIV-1 group M), sub-subtype (A1-A4 for subtype A, F1 and F2 for subtype F in HIV-1 group M), circulating recombinant forms (CRF), and unique recombinant forms in a small number of patients. Virological diagnostic and monitoring techniques have been constantly upgraded since HIV-1 was isolated in 1983 and the first serological tests became available in 1985. This is especially true for HIV-1, the most prevalent worldwide.     

The Role of Chromatin in Adenoviral Vector Function

Vectors based on adenovirus (Ad) are one of the most commonly utilized platforms for gene delivery to cells in molecular biology studies and in gene therapy applications. Ad is also the most popular vector system in human clinical gene therapy trials, largely due to its advantageous characteristics such as high cloning capacity (up to 36 kb), ability to infect a wide variety of cell types and tissues, and relative safety due to it remaining episomal in transduced cells. The latest generation of Ad vectors, helper‑dependent Ad (hdAd), which are devoid of all viral protein coding sequences, can mediate high-level expression of a transgene for years in a variety of species ranging from rodents to non-human primates. Given the importance of histones and chromatin in modulating gene expression within the host cell, it is not surprising that Ad, a nuclear virus, also utilizes these proteins to protect the genome and modulate virus- or vector‑encoded genes. In this review, we will discuss our current understanding of the contribution of chromatin to Ad vector function.