537 research outputs found

    The Association of the Human Leukocyte Antigen (HLA) with the Pathogenesis of Helicobacter pylori

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    H. pylori pathogenesis is related to various virulence factor which some of them involved to adhesions. Urease as a main pathogenecity factor to attach to HLA-II is expressed on the surface of Gastric Epithelial Cells (GECs). Apoptosis induced by caspase3 activation as a result of urease effects on Spermine-Spermidine cycle. There is a contribution of HLA-DQA1 gene to the host's response against H. pylon. HLA allele type as an immune-genetic factors are related to host susceptibility to H. pylori. HLA-DQA1 might be contributed to the susceptibility or resistance to H. pylori infection. Based on the existed evidences the current review aimed to evaluate the results obtained by different studies carried out so far on correlation of human HLA and the pathogenesis of the H. pylori in gastric epithelial cells

    Effects of data resolution and stream delineation threshold area on the results of a kinematic wave based GIUH model

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    This research addresses the effect of using digital elevation models (DEMs) derived from different sources on the results of a kinematic wave based GIUH model. DEMs from different sources exhibit data-resolution effects on the important derived geomorphological properties of watersheds used in rainfall–runoff modelling. Using DEMs derived from topography maps (TOPO DEM) and the SRTM DEM, it was illustrated that different threshold areas for stream network extraction affect GIUH model performance. The results show that the SRTM DEM gives higher values for sub-basin and channel slope as well as number of streams, than the TOPO DEM, while mean length of overland and channel flow is greater for the latter source. The results also indicate that peak flow and slope of the hydrograph rising limb obtained from the SRTM DEM at different threshold areas (ranging from 0.25% to 3%) are greater than that for the TOPO DEM. Investigating the effects of stream network delineation threshold area on the simulated peak flow shows that the maximum and minimum differences (12% and 1%) occur at the threshold areas of 0.5% and 1%, respectively, while for threshold areas higher than 2% the difference in peak flow of the two sources is limited to 10%. Based on the results of this research, it is deduced that the effects of data resolution and stream network delineation threshold areas on the geomorphological parameter values and the performance of GIUH-based models are significant and should be  considered when using SRTM DEMs in ungauged watersheds.Keywords: SRTM DEM, topographic maps, rainfall–runoff Modelling, KW-GIUH, threshold are

    Finite element simulation of retrogressive failure of submarine slopes

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    To simulate earthquake-induced, retrogressive submarine slope failures, element removal capabilities of a finite element program are used to model a soil mass that fails and then flows away, causing upper parts of slope to fail retrogressively due to loss of support. It is explained how an initial failure leads to subsequent failures of a flat or gently sloping seafloor. Effects of a silt layer and gently sloping seafloor on the extension of retrogression in a sand deposit are studied. The extension of failure increases significantly for a gently sloping seafloor with the presence of a silt layer

    The role of T regulatory lymphocytes in lymphoma

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    T regulatory cells play a crucial role in immunological unresponsiveness to selfantigens and in suppressing excessive immune responses deleterious to the host. T regulatory cells are produced in the thymus as a functionally mature subpopulation of T cells. They can be induced from naive T cells in the periphery and express their marker as a forkhead/winged helix transcription factor called FoxP3. In patients with lymphomas where T regulatory cells serve as suppressor anti-tumor cytotoxicity, decreased numbers of T regulatory cells are associated with a favorable prognosis. In contrast, in patients with lymphomas where T regulatory cells function as anti-tumor cytotoxic agents, enhanced numbers of T regulatory cells are associated with a favorable prognosis. Tumors actively promote the accumulation of these cells through several mechanisms that involve activation of naturally occurring T regulatory cells as well as conversion of non-T regulatory cells into T regulatory cells. Tumor-derived prostaglandin E2 can increase T regulatory cell activity and induce a regulatory phenotype in CD4+CD25+T cells. On the other hand, a balance between T regulatory and Th17 cells is essential for maintaining homeostasis of anti-tumor immunity. Accelerating processes such as increasing the amounts of IL-6 or IL-17 can enhance FoxP3 T regulatory cell expression and result in a lymphoma or inactivation of T cell CD4+. This effect is the reason for malignancy and a reduction in anti-tumor immune response. In this systematic review we intend to analyze this relationship. We have collected and analyzed the majority of recently published articles on the role of T regulatory cells as a review article

    Temporal Segmentation of Surgical Sub-tasks through Deep Learning with Multiple Data Sources

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    Many tasks in robot-assisted surgeries (RAS) can be represented by finite-state machines (FSMs), where each state represents either an action (such as picking up a needle) or an observation (such as bleeding). A crucial step towards the automation of such surgical tasks is the temporal perception of the current surgical scene, which requires a real-time estimation of the states in the FSMs. The objective of this work is to estimate the current state of the surgical task based on the actions performed or events occurred as the task progresses. We propose Fusion-KVE, a unified surgical state estimation model that incorporates multiple data sources including the Kinematics, Vision, and system Events. Additionally, we examine the strengths and weaknesses of different state estimation models in segmenting states with different representative features or levels of granularity. We evaluate our model on the JHU-ISI Gesture and Skill Assessment Working Set (JIGSAWS), as well as a more complex dataset involving robotic intra-operative ultrasound (RIOUS) imaging, created using the da Vinci® Xi surgical system. Our model achieves a superior frame-wise state estimation accuracy up to 89.4%, which improves the state-of-the-art surgical state estimation models in both JIGSAWS suturing dataset and our RIOUS dataset

    Bacterial Heat Shock Protein Activity

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    Bacteria are exposed to different types of stress in their growth conditions. They have developed appropriate responses, modulated by the re-modeling of protein complexes and by phosphorylation dependent signal transduction systems, to adapt and to survive in a variety range of nature. Proteins are essential components for biologic activity in the eukaryotic and prokaryotic cell. Heat Shock Proteins (HSP) have been identified from various organisms and have critical role in cell hemostasis. Chaperone can sense environment and have different potential role in the organism evolution

    Sonographic evaluation of cervical lymphadenopathy; Comparison of metastatic and reactive lymph nodes in patients with head and neck squamous cell carcinoma using gray scale and doppler techniques

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    Background: Cervical lymphadenopathy could be seen in several pathologic processes. An accurate differentiation between these conditions is of utmost importance to select an appropriate therapy and assess the prognosis. Gray scale and Doppler are appropriate sonographic techniques for evaluating internal and external features of lymph nodes. Although, various criteria have been proposed to differentiate metastatic lymph nodes from benign ones, the most valuable and specific sonographic features are still under dispute. Objectives: The present study was designed to determine valuable sonographic features for differentiating metastasis from benign nodes using gray scale and Doppler sonography. Patients and Methods: A prospective diagnostic study was performed on 63 patients with head and neck squamous cell carcinoma (SCC) treated and referred to surgery clinic of Hazrat Rasoul Akram hospital from November 2010 to June 2012 with complaint of palpable cervical lymph node. All patients� necks were scanned multidirectionally by gray-scale and Doppler techniques. After sonography, lymph nodes were biopsied and investigated to find out whether they were metastatic or reactive. Finally, demographic, sonographic and pathologic data were statistically analyzed by SPSS ver. 16 software using t-test, a nonparametric test and ROC analysis. Ninety five percent confidence interval was considered for all parameters. Results: The study included 41 males and 22 females with a mean age of 57.56 ± 13.79 years. The number of metastatic lymph nodes was 47, while the remaining 16 were reactive. There were significant differences in length (P = 0.037), width (P = 0.001), resistance index (P < 0.001), pulsatility index (P < 0.001) and systolic velocity (P < 0.001) of metastatic and reactive lymph nodes. Cut points for resistive and pulsatility indexes and systolic velocity were calculated as 0.695, 1.35 and 16.5, respectively. The most valuable factor for defining a lymph node as metastatic was circulation pattern with accuracy, sensitivity and specificity of 94, 85 and 93, respectively. Conclusion: Gray scale sonography in combination with Doppler sonography could be a trustworthy technique in differentiating metastatic lymph nodes from reactive ones. Although, circulation pattern had a higher diagnostic accuracy in the present study, combination of sonographic characteristics could be more beneficial in differentiating metastatic cervical nodes from reactive ones. © 2015, Tehran University of Medical Sciences and Iranian Society of Radiology

    Response of lettuce to Cd-enriched water and irrigation frequencies

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    This pot experiment was an attempt to investigate a broad response of lettuce to different cadmium (Cd) levels of irrigation water (0, 5, 10 and 20 mg l-1) under different irrigation intervals (1, 2 and 4 days). The results showed that increased level of soil Cd through irrigation eventually decreased the yield of lettuce in all cases; however, in some cases yield was increased with lower doses of Cd application. No injury symptoms were observed other than plant height and yield reduction. Shoot dry weight proved to be the most sensitive parameters to the cadmium, especially under water stress conditions. The results also showed that the concentrations of nutrient elements in lettuce shoot were suppressed by water stress. The presence of cadmium in irrigation water did not significantly affect the absorption of nutrient elements by plants except for Fe. Shoot Cd concentration and its uptake decreased with increasing irrigation frequencies and the reverse trend occurred with increasing Cd levels of irrigation water. However, the values were higher than recommended guideline in all conditions. Also, shoot Cd content showed a significant positive correlation with the final accumulated Cd concentration of soil and was expressed by a plateau model under the dry irrigation regime and linear models at other irrigation intervals. Overall, shoot Cd concentration was predicted by using a simple linear regression model regardless of evapotranspiration and transpiration rate of plant.Key words: Cadmium toxicity; chemical composition; irrigation frequency; lettuce

    Contribution of Blastocystishominis subtypes and associated inflammatory factors in development of irritable bowel syndrome

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    Blastocystis hominis with worldwide distribution is a human intestinal protozoa found in all countries. There have been differences in the severity of the pathogenesis of various Blastocystis spp. and a concomitant variation in the plasma concentration of the cytokines in patients with irritable bowel syndrome. In the present study, we aimed to demonstrate the contribution of B. hominis subtypes in the development of irritable bowel syndrome. Stool samples were collected from patients with gastrointestinal disorders. All samples were evaluated through native-lugol method. Total DNA was extracted. A PCR protocol was developed to amplify a specific region of the SSU ribosomal DNA (rDNA) gene. Serum levels of IL-6 and TNF-alpha were determined by immunoassay methods. The ClustalW algorithm was applied to align and blast the nucleotide sequences of the amplified region of the SSU rDNA gene. To evaluate the phylogenetic and molecular evolutionary of the nucleotide sequences, we used the MEGA software. In this study, we found 26 haplotypes of B. hominis in the studied samples which were collectively belong to five subtypes (ST1, ST2 in patients without irritable bowel syndrome vs. ST3 and two unknown subtypes in patients with irritable bowel syndrome). Result of ELISA showed a high level of IL-6 and TNF-alpha in the serum of patients with irritable bowel syndrome. The genetic heterogeneity of B. hominis and the existence of different subtypes of the protozoan in patients with IBS may shed light to the fact that some subtypes of parasites may involve in the pathogenesis of IBS

    Contribution of Blastocystishominis subtypes and associated inflammatory factors in development of irritable bowel syndrome

    Get PDF
    Blastocystis hominis with worldwide distribution is a human intestinal protozoa found in all countries. There have been differences in the severity of the pathogenesis of various Blastocystis spp. and a concomitant variation in the plasma concentration of the cytokines in patients with irritable bowel syndrome. In the present study, we aimed to demonstrate the contribution of B. hominis subtypes in the development of irritable bowel syndrome. Stool samples were collected from patients with gastrointestinal disorders. All samples were evaluated through native-lugol method. Total DNA was extracted. A PCR protocol was developed to amplify a specific region of the SSU ribosomal DNA (rDNA) gene. Serum levels of IL-6 and TNF-alpha were determined by immunoassay methods. The ClustalW algorithm was applied to align and blast the nucleotide sequences of the amplified region of the SSU rDNA gene. To evaluate the phylogenetic and molecular evolutionary of the nucleotide sequences, we used the MEGA software. In this study, we found 26 haplotypes of B. hominis in the studied samples which were collectively belong to five subtypes (ST1, ST2 in patients without irritable bowel syndrome vs. ST3 and two unknown subtypes in patients with irritable bowel syndrome). Result of ELISA showed a high level of IL-6 and TNF-alpha in the serum of patients with irritable bowel syndrome. The genetic heterogeneity of B. hominis and the existence of different subtypes of the protozoan in patients with IBS may shed light to the fact that some subtypes of parasites may involve in the pathogenesis of IBS
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