638 research outputs found

    The association between right ventricular function and exercise capacity for hypertensive patients

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    Background: Transthoracic echocardiography (TTE) would be used to evaluate right ventricular (RV) function in patients with arterial hypertension, and the link between RV dysfunction and exercise capacity was studied in the study population.Objective: To establish a correlation with exercise capability in the study group by using transthoracic echocardiography (TTE) to evaluate RV function in patients with arterial hypertension.Patients and Methods: Patients with hypertension were surveyed in a cross-sectional research; those known and treated; whether controlled or not and patients who were recently discovered to be hypertensive. Ninety patients were included; gender and age were taken into account. A thorough examination was performed on each patient (TTE) as well as six minute walking distance (6MWD). For all we had a written informed consent prior to enrollment. Results: Patients with untreated and uncontrolled hypertension showed significantly reduced right ventricular systolic and diastolic functions compared to those with well-controlled hypertension. Patients with untreated or uncontrolled hypertension had significant (P <0.001) deterioration on S', wave and diastolic dysfunction parameters (E/A, DTt, E/e t and IVRT). Untreated and uncontrolled hypertension patients showed a significant decrease in 6MWD compared to the well-controlled individuals (P <0.001). Conclusion: Untreated or ineffectively treated hypertension individuals had considerably reduced right ventricular function and exercise capacity, according to our findings. In the entire research population, right ventricular functions are strongly linked to exercise ability

    The effect of placenta previa on fetal weight and feto-maternal blood flow: a prospective cohort study

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    Background: The current study aims to evaluate the effect of placenta previa on the fetal weight and to explore its effect on the uterine and umbilical arteries blood flow.Methods: The current study was a prospective cohort study conducted at Assiut Women’s Health Hospital, Egypt from 1st of October 2016 to 30th of September 2017 including placenta previa and non-placenta previa women. They were followed up by two-dimensional ultrasound and Doppler blood flow in the uterine and umbilical arteries. The main study outcome was the number of low birth weight (LBW) babies delivered at or beyond 37 weeks and blood flow changes in uterine and umbilical arteries.Results: Two hundred twelve women were divided into two groups; group I included 106 placenta previa women (PP group) and 106 non-placenta previa women (NPP group). The number of LBW babies were comparable in both groups without statistically significant difference (P value= 0.555). Neither; uterine artery nor umbilical artery blood flow had any significant differences between the groups.  Preterm delivery was significantly higher in the PP group (p value=0.000).Conclusions: Although there is no agreement, in the literature, on the association between placenta previa and LBW, authors suggest that placenta previa is not a reason for LBW babies. In addition, placenta previa shows no effect on uterine artery or umbilical artery blood flow

    Autonomous Optimal Absolute Orbit Keeping through Formation Flying Techniques

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    peer reviewedIn this paper, the problem of autonomous optimal absolute orbit keeping for a satellite mission in Low Earth Orbit using electric propulsion is considered. The main peculiarity of the approach is to support small satellite missions in which the platform is equipped with a single thruster nozzle that provides acceleration on a single direction at a time. This constraint implies that an attitude maneuver is necessary before or during each thrusting arc to direct the nozzle into the desired direction. In this context, an attitude guidance algorithm specific for the orbit maneuver has been developed. A Model Predictive Control scheme is proposed, where the attitude kinematics are coupled with the orbital dynamics in order to obtain the optimal guidance profiles in terms of satellite state, reference attitude, and thrust magnitude. The proposed control scheme is developed exploiting formation flying techniques where the reference orbit is that of a virtual spacecraft that the main satellite is required to rendezvous with. In addition to the controller design, the closed-loop configuration is presented supported by numerical simulations. The efficacy of the proposed autonomous orbit-keeping approach is shown in several application scenarios.Autonomous Constellation and Formation Control of Microsatellite

    Efficacy of Mesenchymal Stem Cells in Suppression of Hepatocarcinorigenesis in Rats: Possible Role of Wnt Signaling

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    <p>Abstract</p> <p>Background</p> <p>The present study was conducted to evaluate the tumor suppressive effects of bone marrow derived mesenchymal stem cells (MSCs) in an experimental hepatocellular carcinoma (HCC) model in rats and to investigate the possible role of Wnt signaling in hepato-carcinogenesis.</p> <p>Methods</p> <p>Ninety rats were included in the study and were divided equally into: Control group, rats which received MSCs only, rats which received MSCs vehicle only, HCC group induced by diethylnitroseamine (DENA) and CCl<sub><b>4</b></sub>, rats which received MSCs after HCC induction, rats which received MSCs before HCC induction. Histopathological examination and gene expression of Wnt signaling target genes by real time, reverse transcription-polymerase chain reaction (RT-PCR) in rat liver tissue, in addition to serum levels of ALT, AST and alpha fetoprotein were performed in all groups.</p> <p>Results</p> <p>Histopathological examination of liver tissue from animals which received DENA-CCl<sub>4 </sub>only, revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules type II with foci of large and small cell dysplasia. Administration of MSCs into rats after induction of experimental HCC improved the histopathological picture which showed minimal liver cell damage, reversible changes, areas of cell drop out filled with stem cells. Gene expression in rat liver tissue demonstrated that MSCs downregulated <it>β-catenin</it>, proliferating cell nuclear antigen (<it>PCNA</it>), <it>cyclin D </it>and <it>survivin </it>genes expression in liver tissues after HCC induction. Amelioration of the liver status after administration of MSCs has been inferred by the significant decrease of ALT, AST and Alpha fetoprotein serum levels. Administration of MSCs before HCC induction did not show any tumor suppressive or protective effect.</p> <p>Conclusions</p> <p>Administration of MSCs in chemically induced HCC has tumor suppressive effects as evidenced by down regulation of Wnt signaling target genes concerned with antiapoptosis, mitogenesis, cell proliferation and cell cycle regulation, with subsequent amelioration of liver histopathological picture and liver function.</p

    Molecular characterization, toxin detection and resistance testing of human clinical Clostridium difficile isolates from Lebanon

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    Clostridium (Clostridioides) difficile is the main cause for nosocomial diarrhoea in industrialised nations. Epidemiologic data on the pathogen’s occurrence in other world regions are still scarce. In this context we characterized with phenotypic and molecular genetic methods C. difficile isolates stemming from hospitalised patients with diarrhoea in Lebanon. From 129 stool samples of symptomatic patients at a tertiary care University hospital in Lebanon, a total of 107 C. difficile strains were cultivated and underwent ribotyping, toxin gene detection and antibiotic resistance testing. Ribotype 014 (RT014, 16.8%) predominated, followed by RT002 (9.3%), RT106 (8.4%) and RT070 (6.5%). Binary toxin gene-positive isolates (RT023, RT078 and RT126) were rarely detected and RT027 was absent. Interestingly, within one isolate only the toxin A gene (tcdA) was detected. Multiple-locus variable-number tandem repeat analysis (MLVA) revealed strong strain diversity in most RTs. The isolates were sensitive to metronidazole and vancomycin, and only a small proportion of strains displayed resistance against moxifloxacin, rifampicin, and clarithromycin (5.6%, 1.9%, and 2.8%), respectively. The data indicate that the genetic strain composition of Lebanese strains differs markedly from the situation seen in Europe and North America. Especially the epidemic RTs seen in the latter regions were almost absent in Lebanon. Interestingly, most strains showed almost no resistance to commonly used antibiotics that are suspected to play a major role in the development of C. difficile infection, despite frequent use of these antibiotics in Lebanon. Thus, the role of antimicrobial resistance as a major driving force for infection development remains uncertain in this area

    Genome-wide coexpression of steroid receptors in the mouse brain: Identifying signaling pathways and functionally coordinated regions

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    Steroid receptors are pleiotropic transcription factors that coordinate adaptation to different physiological states. An important target organ is the brain, but even though their effects are well studied in specific regions, brain-wide steroid receptor targets and mediators remain largely unknown due to the complexity of the brain. Here, we tested the idea that novel aspects of steroid action can be identified through spatial correlation of steroid receptors with genome-wide mRNA expression across different regions in the mouse brain. First, we observed significant coexpression of six nuclear receptors (NRs) [androgen receptor (Ar), estrogen receptor alpha (Esr1), estrogen receptor beta (Esr2), glucocorticoid receptor (Gr), mineralocorticoid receptor (Mr), and progesterone recep

    Hypointense Hepatic Lesions Depicted on Gadobenate Dimeglumine-Enhanced Three-Hour Delayed Hepatobiliary-Phase MR Imaging: Differentiation between Benignancy and Malignancy

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    Gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging simultaneously provides both morphological and functional information by the acquisition of dynamic and hepatobiliary-phase imaging. Focal lesions with no functioning hepatocytes, where hepatobiliary metabolism is blocked or inhibited, are generally unable to uptake and excrete gadobenate dimeglumine into the bile. Such lesions are typically malignant and usually appear hypointense as compared to the normal liver parenchyma as seen on hepatobiliary-phase imaging. However, various benign hepatic lesions may also be hypointense due to (a) the presence of no functioning hepatocytes, (b) damage to the functioning hepatocytes or (c) impairment of biliary function as depicted on hepatobiliary-phase imaging. All of these imaging features may result in recognition of the benign hepatic lesions as hepatic malignancies. As depicted on three-hour delayed hepatobiliary-phase imaging, peripheral iso/hyperintensity due to fibrotic tissue compared to the hypointense center with a fuzzy margin may be a clue for the presence of a benign hepatic lesion. In contrast, peripheral hypointensity due to rich tumoral cellularity compared to the center with a clear margin may favor an indication of the presence of a malignant hepatic lesion

    Transcriptional Downregulation of Rice rpL32 Gene under Abiotic Stress Is Associated with Removal of Transcription Factors within the Promoter Region

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    Background: The regulation of ribosomal proteins in plants under stress conditions has not been well studied. Although a few reports have shown stress-specific post-transcriptional and translational mechanisms involved in downregulation of ribosomal proteins yet stress-responsive transcriptional regulation of ribosomal proteins is largely unknown in plants. Methodology/Principal Findings: In the present work, transcriptional regulation of genes encoding rice 60S ribosomal protein L32 (rpL32) in response to salt stress has been studied. Northern and RT-PCR analyses showed a significant downregulation of rpL32 transcripts under abiotic stress conditions in rice. Of the four rpL32 genes in rice genome, the gene on chromosome 8 (rpL32_8.1) showed a higher degree of stress-responsive downregulation in salt sensitive rice variety than in tolerant one and its expression reverted to its original level upon withdrawal of stress. The nuclear run-on and promoter:reporter assays revealed that the downregulation of this gene is transcriptional and originates within the promoter region. Using in vivo footprinting and electrophoretic mobility shift assay (EMSA), cis-elements in the promoter of rpL32_8.1 showing reduced binding to proteins in shoots of salt stressed rice seedlings were identified. Conclusions: The present work is one of the few reports on study of stress downregulated genes. The data revealed that rpL32 gene is transcriptionally downregulated under abiotic stress in rice and that this transcriptional downregulation i
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