The frequency of vitamin D deficiency among asthmatic Egyptian children

Background: Vitamin D plays a role in the pathogenesis of asthma as it has a potent immunomodulatory effect acting on the cells of the innate immunity. It also reduces the risk of respiratory viral infections which are important initiators of asthma exacerbations. Besides, it potentiates the antiinflammatory action of corticosteroids which are considered the mosteffective controllers of asthma. Objective: To detect the frequency of vitamin D insufficiency and deficiency among Egyptian asthmatic children and to correlate vitamin D levels to the severity of asthma. Methods: This case control study was conducted on 60 asthmatic children and 40 healthy controls. All were subjected to clinical history taking including history of sun exposure and asthma medications and full clinical examination. Laboratory investigations included measurement of serum calcium, serum alkaline phosphatase and serum 25-OH-D levels and lung functions (spirometery). Results: There was a significant correlation between vitamin D deficiency and severity of asthma, yet there was no significant relation between sun exposure and 25-OH-D level. Moreover, there was a significant relation between decreased serum 25-OH-D levels and the intensity of corticosteroid use. Vitamin D was also significantly lower in asthmatic patients with coexistent allergic rhinitis. Conclusion: Vitamin D deficiency is prevalent in Egyptian children with asthma .Lower levels of serum vitamin D are associated with high asthma severity, reduced asthma control and increased corticosteroid use.Keywords: Vitamin D, Bronchial asthma, Egyptian, Childre

A Subset of Replication Proteins Enhances Origin Recognition and Lytic Replication by the Epstein-Barr Virus ZEBRA Protein

ZEBRA is a site-specific DNA binding protein that functions as a transcriptional activator and as an origin binding protein. Both activities require that ZEBRA recognizes DNA motifs that are scattered along the viral genome. The mechanism by which ZEBRA discriminates between the origin of lytic replication and promoters of EBV early genes is not well understood. We explored the hypothesis that activation of replication requires stronger association between ZEBRA and DNA than does transcription. A ZEBRA mutant, Z(S173A), at a phosphorylation site and three point mutants in the DNA recognition domain of ZEBRA, namely Z(Y180E), Z(R187K) and Z(K188A), were similarly deficient at activating lytic DNA replication and expression of late gene expression but were competent to activate transcription of viral early lytic genes. These mutants all exhibited reduced capacity to interact with DNA as assessed by EMSA, ChIP and an in vivo biotinylated DNA pull-down assay. Over-expression of three virally encoded replication proteins, namely the primase (BSLF1), the single-stranded DNA-binding protein (BALF2) and the DNA polymerase processivity factor (BMRF1), partially rescued the replication defect in these mutants and enhanced ZEBRA's interaction with oriLyt. The findings demonstrate a functional role of replication proteins in stabilizing the association of ZEBRA with viral DNA. Enhanced binding of ZEBRA to oriLyt is crucial for lytic viral DNA replication

ICAR: endoscopic skull‐base surgery

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The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Thymectomy in non thymomatous myasthenia gravis: Impact of pathology on outcome and role of survivin in pathogenesis

Background: Myasthenia gravis is an autoimmune disorder characterized by production of acetylcholine receptor antibodies. These antibodies are mainly produced by thymic B-lymphocytes. Our aim was to detect the correlation between thymic pathology and outcome of myasthenia gravis. Moreover, we tried to detect the involvement of survivin as an apoptosis inhibitor in pathogenesis of myasthenia. Methods: This study was a prospective study conducted on 36 non thymomatous myasthenic patients subjected to thymectomy. Patients were followed for 6 months after operation. Moreover, 36 control normal thymic specimens were obtained from patients operated for open heart surgery. Resected thymic tissue was sent for histopathological examination and immunohistochemical staining by survivin to examine its role in pathogenesis of myasthenia. Results: Patients were divided into group A with hyperplastic thymus and group B with atrophic thymus. Nine patients had no improvement after surgery and the remaining had variable degrees of clinical improvement. Pathology of thymus did not affect clinical outcome with significant improvement in both groups. Decreased duration of symptoms before surgery and female sex are statistically associated with more improvement of patients' symptoms. Positive expression of survivin was detected in germinal centers of all hyperplastic and atrophic thymuses. All the control thymuses were negative for survivin expression. Conclusion: Thymectomy for myasthenia gravis is an effective and beneficial procedure even in patients with atrophic thymus. Survivin is expressed in all myasthenic thymuses confirming its role in pathogenesis of myasthenia gravis

Use of non radioactive nucleic probes for epidemiological survey of potato tuber moth granulosis virus

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