Stress-induced changes in the aged-rat adrenal cortex. Histological and histomorphometric study

Background: Stress exposure exerts direct effects on the morphology and functionality of the adrenal cortex. In addition, ageing effects growth, differentiation, apoptosis and cellularity of the cortex. The missing data is the combined effect of stress and ageing on the adrenal cortex. The aim of this study was to demonstrate the structural changes in the adrenal cortex following the exposure to stress in the adult and aged albino rats.   Materials and methods: Forty rats were divided into groups I and II (adult and senile). Each group was further subdivided into subgroups a and b (control and stressed). Light and electron microscopic studies were done. Area per cent of collagen fibres (Masson’s trichrome-stained sections), number of proliferating cells (optical density immunoreactivity in the Ki67 stained sections) and thickness of the three adrenal zones were also measured.   Results: Lamellar separation of the capsule with subcapsular spindle cell hyperplasia and areas of ghost cells were observed in zona glomerulosa (ZG) and zona fasciculata (ZF) in group I-b. Separation and indentation of the capsule with its lamellar separation were observed in group II-a with the existence of multiple scattered degenerative foci in ZF and zona reticularis (ZR). Similar and aggressive was the architectural pattern of ZF in group II-b with the presence of areas of homogenous degeneration. The nuclei of ZG had marginated chromatin in group I-b and were pyknotic with deformed irregular outlines in group II-b. Multiple lysosomes and vacuolar degeneration mitochondria were also seen in group I-b. The nuclei of ZF were irregular with condensed marginated heterochromatin in group I-b, irregular with scattered chromatin in group II-a and indented with areas of chromatin destruction in group II-b. Mitochondria with disrupted cristae and cristolysis were also detected in group I-b. Numerous lipofuscin granules and dilated smooth endoplasmic reticulum were revealed in group II-b. The mean collagen fibre area per cent and the mean number of the proliferating cells in group II-b were significantly higher by 39% and 23%. The thickness of ZG decreased significantly by 20% in group I-b. Contrary, the thickness of both ZF and ZR increased significantly by 10% in group I-b.   Conclusions: Histological alterations occurred in the adrenal cortex in response to stress, especially when coupled with the advance of age. This was accompanied by increase in the area per cent of collagen fibres and increase in the mean number of the proliferating cells in the adrenal cortex

Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk

Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored. Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10−4; OR, 1.04; 95% confidence interval (CI), 1.02–1.07] and rs77928427 (P = 1.86 × 10−4; OR, 1.04; 95% CI, 1.02–1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 ≥ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor–binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue. Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2. Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk

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

Natural gas dehydration by desiccant materials

Water vapor in a natural gas stream can result in line plugging due to hydrate formation, reduction of line capacity due to collection of free water in the line, and increased risk of damage to the pipeline due to the corrosive effects of water. Therefore, water vapor must be removed from natural gas to prevent hydrate formation and corrosion from condensed water. Gas dehydration is the process of removing water vapor from a gas stream to lower the temperature at which water will condense from the stream; this temperature is called the “dew point” of the gas. Molecular sieves are considered as one of the most important materials that are used as desiccant materials in industrial natural gas dehydration. This work shows a study of natural gas dehydration using 3A molecular sieve as a type of solid desiccant materials, the scope of this work was to build up a pilot scale unit for a natural gas dehydration as simulation of actual existing plant for Egyptian Western Desert Gas Company (WDGC). The effect of different operating conditions (water vapor concentration and gas flow rate) on dehydration of natural gas was studied. The experimental setup consists of cylinder filled with 3A molecular sieve to form a fixed bed, then pass through this bed natural gas with different water vapor concentration, The experimental setup is fitted with facilities to control bed pressure, flow rate, measure water vapor concentration and bed temperature, a gas heater was used to activate molecular sieve bed. Increasing water vapor concentration in inlet feed gas leads to a marked decrease in dehydration efficiency. As expected, a higher inlet flow rate of natural gas decrease dehydration efficiency. Increasing feed pressure leads to higher dehydration efficiency

Comparison between some techniques used for early detection of ventilator-associated infection

Background Although mechanical ventilation could be lifesaving, yet it could be the cause of death owing to its complications. One of the reasons of death is the infection being challenging to the clinicians to diagnose owing to the clinical variability and a wide scale of diseases causing fever and chest infiltrates. The earlier the established diagnosis and proper therapy, the better the outcome. The objective was to compare between different methods used for the early diagnosis of ventilator-associated infection. Patients and methods The study included 50 patients mechanically ventilated for 72 h. The patients were subjected to basic clinical data collection, laboratory investigations, chest radiography, endotracheal aspiration (ETA), and bronchoalveolar lavage (BAL). Direct Gram stain and bacterial culture were done for both the aspirate and the lavage fluid. Results and conclusion A total of 27 patients were found to be infected. Agreement between direct Gram staining and bacterial culture of ETA was recorded in 64% of the cases, whereas the agreement with BAL was recorded in 76%. Overall agreement between ETA and BAL culture results was seen in 44%. From the previous results, ETA should not replace BAL as a diagnostic modality

Parallel Combinatorial Optimization with Decision Diagrams

Abstract. We propose a new approach for parallelizing search for com-binatorial optimization that is based on a recursive application of approx-imate Decision Diagrams. This generic scheme can, in principle, be ap-plied to any combinatorial optimization problem for which a decision dia-gram representation is available. We consider the maximum independent set problem as a specific case study, and show how a recently proposed sequential branch-and-bound scheme based on approximate decision di-agrams can be parallelized efficiently using the X10 parallel program-ming and execution framework. Experimental results using our parallel solver, DDX10, running on up to 256 compute cores spread across a clus-ter of machines indicate that parallel decision diagrams scale effectively and consistently. Moreover, on graphs of relatively high density, paral-lel decision diagrams often outperform state-of-the-art parallel integer programming when both use a single 32-core machine.