133 research outputs found

    Structural and functional studies of the heptose modifying enzymes that play a role in Campylobacter jejuni virulence.

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    Campylobacter jejuni is a major cause of gastroenteritis in humans. The capsule of some species contains unique modified heptoses. Heptose modification was elucidated for C. jejuni NCTC11168 and 18-176, and novel epimerases and reductases essential for the heptose modification were identified. We hypothesized that heptose modifying enzymes in C. jejuni have specific catalytic residues that allow for substrate and product specificity. Substrate synthesis, structural modeling, point mutations, and enzymatic analysis have been applied to map the active sites. Putative catalytic residues showed substrate and/or product specificity. The epimerases structures were solved by crystallography done by our collaborator. We also hypothesized that synthesis of the modified heptoses is important for biofilm formation. In vitro experiment of C. jejuni NCTC11168 showed that the heptose biosynthesis mutants have a significant reduction in biofilm formation under aerobic conditions. This project has provided essential information about the structure and mechanism of heptose modifying enzymes. It also will emphasize their importance in C. jejuni virulence

    Low Complexity V-BLAST MIMO-OFDM Detector by Successive Iterations Reduction

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    V-BLAST detection method suffers large computational complexity due to its successive detection of symbols. In this paper, we propose a modified V-BLAST algorithm to decrease the computational complexity by reducing the number of detection iterations required in MIMO communication systems. We begin by showing the existence of a maximum number of iterations, beyond which, no significant improvement is obtained. We establish a criterion for the number of maximum effective iterations. We propose a modified algorithm that uses the measured SNR to dynamically set the number of iterations to achieve an acceptable bit-error rate. Then, we replace the feedback algorithm with an approximate linear function to reduce the complexity. Simulations show that significant reduction in computational complexity is achieved compared to the ordinary V-BLAST, while maintaining a good BER performance.Comment: 6 pages, 7 figures, 2 tables. The final publication is available at www.aece.r

    A novel nonsense mutation in cathepsin C gene in an Egyptian patient presenting with Papillon–Lefe`vre syndrome

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    Background: Cathepsin C gene (CTSC) (MIM#602365) is a lysosomal cysteine proteinase coding gene which encodes for CTSC protein that plays a major role in the activation of granule serine proteases, particularly leukocyte elastase and granzymes A and B. This activity was proposed to play a role in epithelial differentiation and desquamation. Mutations that cause Disruption in the CTSC expression or function will result in loss of immunological response such as defects of phagocytic function and deregulation of localized polymorphonuclears response with subsequent clinical manifestation.Aim: The aim of this study is to detect the mutation in CTSC gene expected to be the cause of Papillon Lefe`vre syndrome (PLS) in an Egyptian patient clinically diagnosed as PLS and to characterize the clinical features.Patient and methods: A 5 year and 3 month old girl from the outpatient’s Oro-Dental Genetics clinic – National Research Center presented with the typical clinical findings of Papillon Lefevre syndrome. Genomic DNA was extracted from peripheral blood samples of the patient, her parents and 20 healthy Egyptian controls using standard procedures. All exons of the CTSC gene were amplified by PCR. Sequence analysis of the patient, her parents and controls was performed for mutation detection.Results: Mutation analysis of the CTSC gene in our patient revealed a novel homozygous nonsense mutation in exon 5 (W237X). Her parents revealed the presence of the same mutation in a heterozygous state. The 20 controls showed only the wild type sequence of all exons (no mutation).Conclusion: This study reported a novel nonsense mutation in the CTSC gene in an Egyptian patient. This novel nonsense mutation is predicted to produce truncated dipeptidyl-peptidase1 causing PLS phenotype in this patient

    Flexural Behavior of Lightweight Composite Ferrocement Plates

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    In recent years, producing lightweight structures is considered as one of the most important application of concrete. It has extensive applications in the architect and insulation work. The main objective of this study is to investigate the behavior and the performance of lightweight ferrocement (LWF) composite plates with lightweight materials as filler materials in flexural. Fifteen lightweight ferrocement (LWF) composite plates were investigated by conducting flexural tests. The main variables are (the thickness of plates, the type of filler materials, the type and number of layers of meshes). The behavior of lightweight ferrocement (LWF) composite plates is investigated by conducting flexural tests on fifteen simply supported rectangular plates under three lines loadings. Fifteen plates represented in twelve lightweight ferrocement (LWF) plates and three conventional reinforced concrete (RC) plates. The ferrocement plates were divided into three groups according to the thickness of plates 6cm, 8cm and 10cm. The structural performances of the LWF and RC plates are investigated in terms of crack load, load-deflection curves, stiffness, energy absorption capacity, ductility index, ultimate flexural load-to-weight ratio, load-strain curves, crack patterns, and the failure modes. The test results revealed remarkable enhancement in the flexural behavior and potential application of lightweight ferrocement (LWF) composite plates to produce lightweight structural elements as compared to that of the reinforced concrete (RC) plates, which lead towards the industrialization of building system and meets with innovation and expansible application of concrete construction technology results in better efficiency of developing of lightweight composite ferrocement plates

    Light and electron microscopic study on the effect of antischizophrenic drugs on the structure of seminiferous tubules of adult male albino rats

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    Introduction. Sexual dysfunction and infertility are symptoms which have been rarely studied in patients treated with antischizophrenic drugs, aripiprazole and olanzapine, for long period. This work aimed to investigate the effects of aripiprazole and olanzapine on the structure of seminiferous tubules of rats at both light microscopic and ultrastructural levels. Material and methods. Sixty adult male rats were divided into 3 groups (n = 20): control group (Group I) and two experimental ones (II and III). Rats in Group II received 2 mg/kg/day aripiprazole while rats in Group III received 0.5 mg/kg/day olanzapine for 14 weeks. Thereafter, testis were removed and processed for both light and electron microscopic study. Qualitative morphological analyses and histomorphometric measurements of seminiferous tubules were performed. Results. Rats in Group II showed reduction of testicular weight, seminiferous tubules’ diameter, epithelial height, spermatogenic count, spermatogenic index and spermatogenic score whereas Sertoli cells count was increased. Olanzapine-treated rats also showed epithelial desquamation, separation and apoptotic changes of germ cells. Sertoli cells showed vacuolization, dilatation of smooth endoplasmic reticulum and accumulation of lipid droplets. Abnormality in the shape and structure of late spermatids and presence of giant cells were also demonstrated. Aripiprazole induced less adverse histological changes in rat testis than olanzapine. Conclusions. Olanzapine followed by aripiprazole had adverse histological effects on the structure of the semi­niferous tubules, which may affect spermatogenesis

    Medical image analysis for the early prediction of hypertension

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    Recently, medical image analysis has become a vital evolving technology that is used in the early diagnosis of various diseases. Medical imaging techniques enable physicians to capture noninvasive images of structures inside the human body (such as bones, tissues, or blood vessels) as well as their functions (such as brain activity). In this study, magnetic resonance angiography (MRA) images have been analyzed to help physicians in the early prediction of hypertension. Hypertension is a progressive disease that may take several years before being fully understood. In the United States, hypertension afflicts one in every three adults and is a leading cause of mortality in more than half a million patients every year. Specific alterations in human brains’ cerebrovasculature have been observed to precede the onset of hypertension. This study presents a computer-aided diagnosis system (CAD) that can predict hypertension prior to the systemic onset of the disease. This MRA-based CAD system is able to detect, track, and quantify the hypertension-related cerebrovascular alterations, then it makes a decision based on the analyzed data about whether each subject is at a high risk of developing hypertension or not. Such kind of prediction can help clinicians in taking proactive and preventative steps to stop the progress of the disease and mitigate adverse events

    الفائض التسويقي من الألبان في القرية المصرية

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    There is a deficit in domestic milk production to cover the national Consumption. The gap between consumption and production reached about 1.3 million tons in 2014.the slow growth in domestic production Indicates that such gap is expecting to expand in the future. The traditional mixed farming system which is the common agricultural system in the Egyptian villages produces about 82% of the domestic annual milk production in Egypt. However, the traditional farmers suffer from poor marketing system including unfair transactions. The study relied on another field survey designed and performed by this study through a Questionnaire. The data were collected during the year 2016 to cover the agricultural year 2015/ 2016. The sample size was 60 farms from two villages in Sharkia governorate. One village was near the urban markets and the other relatively far from those markets. Such field sample survey data were used to estimate an economic model of the dairy market surplus in the Egyptian village. The results of the economic model of the dairy market surplus in the Egyptian village showed that every additional 1- kg of milk production from adds about 0.87 kilograms to the milk marketed surplus. While a same increase of cow milk adds about 0.82 kilogram to the marketed surplus., the rest of the marginal increase, is directed to the consumption of the farm household. While the village fare from the urban market sold 64% of the milk marketed surplus to the wholesalers, only 46% was sold from the other village close to the market to the same outlet. The module, also showed that the market milk surplus from the village near the urban markets increased by 408 kilogram of buffalo milk and by 511 cow milk above that sold from the village far from the urban markets

    استهلاك منتجات الألبان من إنتاج المزرعة والأمن الغذائي للأسرة الريفية

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    The study used the data of the household budget survey conducted by CAPMAS for the year 2014, to recognize the objective of this study. It was to specify the consumption pattern of milk and dairy products of the Egyptian rural household and to identify the socio-economic factors affecting this consumption pattern. The major results showed that the household with the small farm holding (less than 5 feddans) has a rational economic policy with concern of such vital food items, particularly for nutritionally vulnerable groups of the population. Such category of households represents 92% of the farm holders in Egypt. The identified econometric model for dairy products consumption showed that the household increases its homeproduced milk and dairy products as the market price of these food items surpasses the costs of production per 1-kg of home produced milk. Such policy decision empowers the household to face the price inflation by increasing self-reliance in the consumption. Of such vital food commodities. However, the households within the rural community decrease the share of home produced milk and dairy products as household income increases. At higher income level the household replace home produced and home processed dairy products for a wide variety of such products purchased from the market. Even though, the dairy products consumption of upper Egypt rural community and border governorates citizens is still affected by the traditions and local community cultures. While the upper Egypt community preference considers milk is children rather than men food, the border governorates prefer sheep and goats dairy products

    Using 3-D CNNs and Local Blood Flow Information to Segment Cerebral Vasculature

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    © 2018 IEEE. The variability of the strength (increase or decrease) of the blood flow signals throughout the range of slices of the MRA volume is a big challenge for any segmentation approach because it introduces more inhomogenities to the MRA data and hence less accuracy. In this paper, a novel cerebral blood vessel segmentation framework using Time-Of-Flight Magnetic Resonance Angiography (TOF-MRA) is proposed to handle this challenge. The segmentation framework is based on using three dimensional convolutional neural networks (3D-CNN) to segment the cerebral blood vessels taking into account the variability of blood flow signals throughout the MRA scans. It consists of the following two steps: i) bias field correction to handle intensity inhomogeneity which are caused by magnetic settings, ii)instead of constructing one CNN model for the whole TOF-MRA brain, the TOF-MRA volume is divided into two compartments, above Circle of Willis (CoW) and at and below CoW to account for blood flow signals variability across the MRA volume\u27s slices, then feed these two volumes into the three dimensional convolutional neural networks (3D-CNN). The final segmentation result is the combination of the output of each model. The proposed framework is tested on in-vivo data (30 TOF-MRA data sets). Both qualitative and quantitative validation with respect to ground truth (delineated by an MRA expert) are provided. The proposed approach achieved a high segmentation accuracy with 84.37% Dice similarity coefficient, sensitivity of 86.14%, and specificity of 99.00%

    Effect of Modifying Mechanical Ventilator Trigger Sensitivity on Arterial Blood Gases in ICU Patients

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    Background: Despite the fact that mechanical ventilation is an essential part in management of critically ill patients, mechanically ventilated patients have a higher risk of complications, which can lead to increased morbidity and mortality. Objective: This study aimed to study the effect of training inspiratory muscle through modifying mechanical ventilator (MV) trigger sensitivity on arterial blood gases in mechanically ventilated patients. Patients and Methods: Sixty adult patients diagnosed with acute respiratory failure, needed to be intubated and connected to mechanical ventilated. They were from both gender and their ages ranged from 50 to 70 years. The patient were chosen from Intensive Care Unit (ICU), Department of Chest Diseases, Cairo University Hospitals. They were randomly assigned into two equal groups. Group (A): included thirty patients who received training for inspiratory muscle through modifying MV trigger sensitivity plus usual physical therapy. Group (B): included thirty patients who received usual physical therapy only. Results: The results showed a significant increase in partial arterial pressure (PaO2) in both groups, this increasing was significantly higher in  patients who received training for the inspiratory muscle plus the usual chest physical therapy than patients who only received usual chest physical therapy (P-value < 0.001). The results showed no significant change in neither power of hydrogen (pH) nor partial pressure of carbon dioxide (PaCO2). Conclusion: Training to inspiratory muscles in mechanically ventilated patient through modifying mechanical ventilator trigger sensitivity can produce a significant increase in partial arterial pressure (PaO2). Although it has no effect in pH nor PaCO2
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