1,860 research outputs found

    Evaluation of radiation dose and image quality following changes to tube potential (kVp) in conventional paediatric chest radiography

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    Purpose: A study of radiation dose and image quality following changes to the tube potential (kVp) in paediatric chest radiography. and Method: A total of 109 patients ranging from 1 month to 15 years were included in two phases of the study. Phase 1 investigated the range of entrance surface air kerma (ESAK) values received from patients exposed to the existing exposure factors. In the second phase, new exposure factors using recommended values of tube potential (kVp) with reduced mAs were used. ESAK values were measured using thermoluminescent dosemeters (TLDs). Image quality in both phases was evaluated using image quality criteria proposed by the Council of the European Communities (CEC). Results of both techniques were analysed for any differences. Results: The overall mean ESAK before the changes was 0.22 mGy (range: 0.05-0.43) Following changes in tube potential, the overall mean reduced to 0.15 mGy (range: 0.03-0.38), a significant reduction by 34%. The interquartile range was reduced from 45% to 40%. However, doses to those below a year in age still remained high. Assessment of image quality was found to have no significant differences as far as the two techniques used were concerned. However, higher image scores were achieved using higher kVps. Conclusion: Significant dose reduction was achieved through appropriate changes in tube potential and reduction of mAs without any loss in image quality. © 2006 Biomedical Imaging and Intervention Journal. All rights reserve

    Molecular and morphological peculiarities of chronic placental insufficiency formation caused by different types of diabetes mellitus

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    Рathogenesis of the chronic placental insufficiency is largely determined by the type of diabetes mellitus and the degree of its compensation. Trophic function failure of placenta changes its hormonal activity, formation of respiratory disorders and development of oxidative stress. The histological structure of placentas among patients with type 1 diabetes mellitus (T1D) is represented by reduced chorionic villi dimensions of all levels. Stromal edema and increased number of mesenchymal stromal cells are found in the stem and intermediate villi, and hypervascularisation and thickening of syncytiocapillary membranes are detected in terminal villi. In type 2 diabetes mellitus (T2D), the histological structure of the placenta may be represented as a premature maturation and abnormal immaturity of the villous tree with focal fibrosis of villi stroma, hypervascularisation of villi, abundance of syncytial nodules and infarction in the subchorial space. The peculiarity of the placenta structure in gestational diabetes mellitus is predominantly an intermediate immature type of development with angiogenesis abnormality. Angiogenesis processes failure and endothelial dysfunction in chorionic villi associated with hyperglycaemia change the permeability of cell membranes, transferring cells to anaerobic respiration. Metabolic imbalance in the placenta causes the development of diabetic micro-angiopathy in the fetal-placental complex, antenatal hypoxia and negative perinatal outcomes

    Discovery and Validation of a New Class of Small Molecule Toll-Like Receptor 4 (TLR4) Inhibitors

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    Many inflammatory diseases may be linked to pathologically elevated signaling via the receptor for lipopolysaccharide (LPS), toll-like receptor 4 (TLR4). There has thus been great interest in the discovery of TLR4 inhibitors as potential anti-inflammatory agents. Recently, the structure of TLR4 bound to the inhibitor E5564 was solved, raising the possibility that novel TLR4 inhibitors that target the E5564-binding domain could be designed. We utilized a similarity search algorithm in conjunction with a limited screening approach of small molecule libraries to identify compounds that bind to the E5564 site and inhibit TLR4. Our lead compound, C34, is a 2-acetamidopyranoside (MW 389) with the formula C17H27NO9, which inhibited TLR4 in enterocytes and macrophages in vitro, and reduced systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. Molecular docking of C34 to the hydrophobic internal pocket of the TLR4 co-receptor MD-2 demonstrated a tight fit, embedding the pyran ring deep inside the pocket. Strikingly, C34 inhibited LPS signaling ex-vivo in human ileum that was resected from infants with necrotizing enterocolitis. These findings identify C34 and the β-anomeric cyclohexyl analog C35 as novel leads for small molecule TLR4 inhibitors that have potential therapeutic benefit for TLR4-mediated inflammatory diseases. © 2013 Neal et al

    The performance of mHealth in cancer supportive care:A research agenda

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    Background: Since the advent of smartphones, mhealth has risen to the attention of all actors in the health care system as something that could radically change the way health care has been thought of, managed, and delivered to date. This is particularly relevant for cancer, as it is one of the leading causes of death worldwide, and for cancer supportive care (CSC) since patients and care givers have a key role in managing side effects: given adequate knowledge, they are able to expect appropriate assessments and interventions. In this scenario, mhealth has great potential for linking patients, care givers, and health care professionals, for enabling early detection and intervention, for lowering costs and achieving better quality of life. Given its great potential, it is important to evaluate the performance of mhealth. This can be considered from several perspectives, of which organizational performance is a particularly relevant dimension, since mhealth may increase the productivity of health care providers and as a result even the productivity of health care systems. Objective: This paper aims to review studies on the evaluation of the performance of mhealth, with particular focus on cancer care and cancer supportive care processes, concentrating on its contribution to organizational performance, and identifying some indications for a further research agenda. Methods: We carried out a review of literature, aimed at identifying studies related to the performance of mhealth in general or focusing on cancer care and cancer supportive care. Results: Our analysis revealed that studies are almost always based on a single dimension of performance. Any evaluations of the performance of mhealth are based on very different methods and measures, with a prevailing focus on issues linked to efficiency. This fails to consider the real contribution that mhealth can offer for improving the performance of health care providers, health care systems, and the quality of life in general

    BCAA catabolism in brown fat controls energy homeostasis through SLC25A44.

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    Branched-chain amino acid (BCAA; valine, leucine and isoleucine) supplementation is often beneficial to energy expenditure; however, increased circulating levels of BCAA are linked to obesity and diabetes. The mechanisms of this paradox remain unclear. Here we report that, on cold exposure, brown adipose tissue (BAT) actively utilizes BCAA in the mitochondria for thermogenesis and promotes systemic BCAA clearance in mice and humans. In turn, a BAT-specific defect in BCAA catabolism attenuates systemic BCAA clearance, BAT fuel oxidation and thermogenesis, leading to diet-induced obesity and glucose intolerance. Mechanistically, active BCAA catabolism in BAT is mediated by SLC25A44, which transports BCAAs into mitochondria. Our results suggest that BAT serves as a key metabolic filter that controls BCAA clearance via SLC25A44, thereby contributing to the improvement of metabolic health

    Seronegative Herpes simplex Associated Esophagogastric Ulcer after Liver Transplantation

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    Herpes simplex infection is characterized by acute or subacute infection, often followed by a chronic carrier state. Consecutive recurrences may flare up if immunocompromise occurs. Herpes simplex associated esophagitis or duodenal ulcer have been reported in immunocompromised patients due to neoplasm, HIV/AIDS or therapeutically induced immune deficiency. Here we report the case of an HSV-DNA seronegative patient who developed grade III dysphagia 13 days after allogeneic liver transplantation. Endoscopy revealed an esophageal-gastric ulcer, and biopsy histopathology showed a distinct fibroplastic and capillary ulcer pattern highly suspicious for viral infection. Immunohistochemistry staining revealed a distinct nuclear positive anti-HSV reaction. Antiviral therapy with acyclovir and high-dose PPI led to a complete revision of clinical symptoms within 48 h. Repeat control endoscopy after 7 days showed complete healing of the former ulcer site at the gastroesophageal junction. Although the incidence of post-transplantation Herpes simplex induced gastroesophageal disease is low, the viral HSV ulcer may be included into a differential diagnosis if dysphagia occurs after transplantation even if HSV-DNA PCR is negative

    Investigation of spaceborne trace gas products over St Petersburg and Yekaterinburg, Russia, by using COllaborative Column Carbon Observing Network (COCCON) observations

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    This work employs ground- and space-based observations, together with model data, to study columnar abundances of atmospheric trace gases (XH2_2O, XCO2_2, XCH4_4 and XCO) in two high-latitude Russian cities, St. Petersburg and Yekaterinburg. Two portable COllaborative Column Carbon Observing Network (COCCON) spectrometers were used for continuous measurements at these locations during 2019 and 2020. Additionally, a subset of data of special interest (a strong gradient in XCH4 and XCO was detected) collected in the framework of a mobile city campaign performed in 2019 using both instruments is investigated. All studied satellite products (TROPOMI, OCO-2, GOSAT, MUSICA IASI) show generally good agreement with COCCON observations. Satellite and ground-based observations at high latitudes are much sparser than at low or mid latitudes, which makes direct coincident comparisons between remote-sensing observations more difficult. Therefore, a method of scaling continuous Copernicus Atmosphere Monitoring Service (CAMS) model data to the ground-based observations is developed and used for creating virtual COCCON observations. These adjusted CAMS data are then used for satellite validation, showing good agreement in both Peterhof and Yekaterinburg. The gradients between the two study sites (ΔXgas) are similar between CAMS and CAMS-COCCON datasets, indicating that the model gradients are in agreement with the gradients observed by COCCON. This is further supported by a few simultaneous COCCON and satellite ΔXgas measurements, which also agree with the model gradient. With respect to the city campaign observations recorded in St Petersburg, the downwind COCCON station measured obvious enhancements for both XCH4_4 (10.6 ppb) and XCO (9.5 ppb), which is nicely reflected by TROPOMI observations, which detect city-scale gradients of the order 9.4 ppb for XCH4_4 and 12.5 ppb for XCO

    Low doses of ethanol decrease the activity of the angiotensin-converting enzyme in the aorta of aging rats and rats treated with a nitric oxide synthase inhibitor and dexamethasone

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    A B S T R A C T In the present study, the activity of ACE (angiotensin-converting enzyme) in the aorta of senescent rats and rats treated with the NOS (NO synthase) inhibitor L-NAME (N G -nitro-L-arginine methyl ester) or dexamethasone and the effect of low doses of ethanol (0.2-1.2 g/kg of body weight, daily for 8-12 days) on this activity were studied. We found that ACE activity increased with age and in response to L-NAME and dexamethasone treatment. Ethanol at a dose of 0.4 g/kg of body weight per day decreased ACE activity in the aorta of aged rats and of rats treated with L-NAME or dexamethasone to the level of activity in young control rats. The optimal ethanol dose (the dose inducing a maximum decrease in ACE activity) increased with increasing doses of dexamethasone: 0.4 g/kg of body weight per day at 30 μg of dexamethasone/kg of body weight and 0.8 g/kg of body weight per day at 100 μg of dexamethasone/kg of body weight. It was also found that optimal doses of ethanol increased the number of cells in the thymus of rats treated with dexamethasone. The optimal dose of ethanol of 0.4 g/kg of body weight per day, which induced a maximum decrease in ACE activity in rat aorta, corresponded to a dose of 30 g of ethanol/day, which, according to epidemiological data, produces a maximum decrease in the incidence of cardiovascular disease in humans. In conclusion, the decrease in ACE activity in vessels may be one of the main mechanisms of the beneficial effects of low doses of ethanol on human health
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