1,935 research outputs found
Excessive growth hormone expression in male GH transgenic mice adversely alters bone architecture and mechanical strength
Patients with acromegaly have a higher prevalence of vertebral fractures despite normal bone mineral density (BMD), suggesting that GH overexpression has adverse effects on skeletal architecture and strength. We used giant bovine GH (bGH) transgenic mice to analyze the effects of high serum GH levels on BMD, architecture, and mechanical strength. Five-month-old hemizygous male bGH mice were compared with age- and sex-matched nontransgenic littermates controls (NT; n=16/group). Bone architecture and BMD were analyzed in tibia and lumbar vertebrae using microcomputed tomography. Femora were tested to failure using three-point bending and bone cellular activity determined by bone histomorphometry. bGH transgenic mice displayed significant increases in body weight and bone lengths. bGH tibia showed decreases in trabecular bone volume fraction, thickness, and number compared with NT ones, whereas trabecular pattern factor and structure model index were significantly increased, indicating deterioration in bone structure. Although cortical tissue perimeter was increased in transgenic mice, cortical thickness was reduced. bGH mice showed similar trabecular BMD but reduced trabecular thickness in lumbar vertebra relative to controls. Cortical BMD and thickness were significantly reduced in bGH lumbar vertebra. Mechanical testing of femora confirmed that bGH femora have decreased intrinsic mechanical properties compared with NT ones. Bone turnover is increased in favor of bone resorption in bGH tibia and vertebra compared with controls, and serum PTH levels is also enhanced in bGH mice. These data collectively suggest that high serum GH levels negatively affect bone architecture and quality at multiple skeletal sites
Utility of palliative EUS-guided biliary drainage using lumen-apposing metal stents: a prospective multicenter feasibility study (with video)
BACKGROUND AND AIMS: Biliary drainage with ERCP is successful in only 80% to 90% of extrahepatic cholangiocarcinoma and pancreatic cancer. We present the results of a multicenter prospective study assessing the safety, feasibility, and quality of life of patients after EUS-guided biliary drainage (EUS-BD) with lumen-apposing metal stents (LAMSs), after failed ERCP. METHODS: All consecutive adults with a dilated common bile duct (CBD) â„14 mm secondary to inoperable malignant distal common bile duct (CBD) stricture and failed ERCP biliary drainage were screened and recruited from 3 tertiary U.K. centers. Technical success of EUS-BD using LAMSs was the primary endpoint. Improvement in serum bilirubin, 30-day mortality, procedure-related adverse events, and quality of life were secondary endpoints. The quality of life improvement was measured using a validated questionnaire (EORTC QLQ-BIL21). RESULTS: Twenty patients were included in analysis. EUS-BD was technically successful in all patients and the clinical success was 95% (19/20) at day 7 (>50% reduction in bilirubin) and 92.3% (12/13) at day 30 (bilirubin <50 ÎŒmol/L). There were significant improvements in overall quality of life score (49 vs 42, p=0.03) at day 30. All cause 30-day mortality was 20% and the moderate adverse event rate was 10% (1 cholangitis and 1 stent migration). CONCLUSION: EUS-BD has acceptable technical success and safety as a second line palliative treatment for inoperable malignant distal CBD strictures. Randomized controlled studies comparing EUS-BD with percutaneous transhepatic biliary drainage (PTBD) are needed to determine their effectiveness in clinical practice
The influence of time and irrigant refreshment on biofilm removal from lateral morphological features of simulated root canals
Aim: To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates. Methodology: A dual-species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96Â h in plug inserts with anatomical features resembling an isthmus or lateral canal-like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1Â mLÂ sâ1. The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15Â min. A three-way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions. Results: For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (PÂ =Â 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (PÂ =Â 0.018 and PÂ =Â 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1Â mLÂ sâ1 flow rate and one or two refreshments removed significant more biofilm (PÂ =Â 0.04, 0.034 and 0.003, <0.001, respectively). Conclusions: In this model, refreshment did not improve biofilm removal from simulated lateral root canal spaces. NaOCl removed more biofilm from the lateral canal- and isthmus-like structure. A higher flow rate removed significantly more biofilm from the isthmus-like structure. There was always remaining biofilm left after the irrigation procedures
Vulnerability of Brazilian municipalities to hantavirus infections based on multiâcriteria decision analysis
Background: Hantavirus infection is an emerging zoonosis transmitted by wild rodents. In Brazil, high case-fatality rates among humans infected with hantavirus are of serious concern to public health authorities. Appropriate preventive measures partly depend on reliable knowledge about the geographical distribution of this disease. Methods: Incidence of hantavirus infections in Brazil (1993â2013) was analyzed. Epidemiological, socioeconomic, and demographic indicators were also used to classify citiesâ vulnerability to disease by means of multi-criteria decision analysis (MCDA). Results: From 1993 to 2013, 1752 cases of hantavirus were registered in 16 Brazilian states. The highest incidence of hantavirus was observed in the states of Mato Grosso (0.57/100,000) and Santa Catarina (0.13/100,000). Based on MCDA analysis, municipalities in the southern, southeastern, and midwestern regions of Brazil can be classified as highly vulnerable. Most municipalities in northern and northeastern Brazil were classified as having low vulnerability to hantavirus cardiopulmonary syndrome. Conclusions: Although most human infections by hantavirus registered in Brazil occurred in the southern region of the country, a greater vulnerability to hantavirus was found in the Brazilian Midwest. This result reflects the need to strengthen surveillance where the disease has thus far gone unreported
Multicenter experience from the UK and Ireland of use of lumen-apposing metal stent for transluminal drainage of pancreatic fluid collections
Background and study aims:âPancreatic fluid collection (PFC) is a common complication of pancreatitis for which endoscopic ultrasound-guided drainage is first-line treatment. A new single-device, lumen-apposing, covered self-expanding metal stent (LAMS) has been licensed for PFC drainage. We therefore present our multicenter experience with the LAMS for PFC drainage in a multicenter prospective case series to assess success and complication rates.
Patients and methods:âAll adult patients from 11 tertiary centers who had LAMS placement for PFC from July 2015 to July 2016 were included. Data including indications, technical success, clinical success, collection resolution, stent removal, early and late adverse events (AEs), mortality and recurrence at 6 months were collected.
Results:â116 patients, median age 52.5 years (range 16âââ80) and 67â% male, were treated with a single LAMS in each case. The indication was walled off necrosis (WON) in 70 and pseudocyst in 46. Median size of the PFC was 11âcm (5âââ21âcm) and the estimated median necrotic volume in WON was 30â% (5â%âââ90â%). Stent insertion was technically successful in 115 (99.1â%) and clinically successful in 109 (94â%). Early serious AEs (SAEs): nâ=â7 sepsis, nâ=â1 stent blockage with food, nâ=â1 stent migration requiring laparotomy, nâ=â1 stent dislodgement and nâ=â1 bleeding requiring emboliZation. Late AEs: nâ=â1 buried stent and nâ=â1 esophageal fistula. Non-procedure-related deaths: nâ=â3 (2.5â%).
Conclusion:âThis multicenter case series demonstrates that use of the new LAMS is feasible, effective and relatively safe in draining PFC with a technical success rate of 99â% and cumulative SAE rate of 11.2â%
Time spent with cats is never wasted: Lessons learned from feline acromegalic cardiomyopathy, a naturally occurring animal model of the human disease
<div><p>Background</p><p>In humans, acromegaly due to a pituitary somatotrophic adenoma is a recognized cause of increased left ventricular (LV) mass. Acromegalic cardiomyopathy is incompletely understood, and represents a major cause of morbidity and mortality. We describe the clinical, echocardiographic and histopathologic features of naturally occurring feline acromegalic cardiomyopathy, an emerging disease among domestic cats.</p><p>Methods</p><p>Cats with confirmed hypersomatotropism (IGF-1>1000ng/ml and pituitary mass; n = 67) were prospectively recruited, as were two control groups: diabetics (IGF-1<800ng/ml; n = 24) and healthy cats without known endocrinopathy or cardiovascular disease (n = 16). Echocardiography was performed in all cases, including after hypersomatotropism treatment where applicable. Additionally, tissue samples from deceased cats with hypersomatotropism, hypertrophic cardiomyopathy and age-matched controls (n = 21 each) were collected and systematically histopathologically reviewed and compared.</p><p>Results</p><p>By echocardiography, cats with hypersomatotropism had a greater maximum LV wall thickness (6.5mm, 4.1â10.1mm) than diabetic (5.9mm, 4.2â9.1mm; Mann Whitney, p<0.001) or control cats (5.2mm, 4.1â6.5mm; Mann Whitney, p<0.001). Left atrial diameter was also greater in cats with hypersomatotropism (16.6mm, 13.0â29.5mm) than in diabetic (15.4mm, 11.2â20.3mm; Mann Whitney, p<0.001) and control cats (14.0mm, 12.6â17.4mm; Mann Whitney, p<0.001). After hypophysectomy and normalization of IGF-1 concentration (n = 20), echocardiographic changes proved mostly reversible. As in humans, histopathology of the feline acromegalic heart was dominated by myocyte hypertrophy with interstitial fibrosis and minimal myofiber disarray.</p><p>Conclusions</p><p>These results demonstrate cats could be considered a naturally occurring model of acromegalic cardiomyopathy, and as such help elucidate mechanisms driving cardiovascular remodeling in this disease.</p></div
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Genetic analysis of a major international collection of cultivated apple varieties reveals previously unknown historic heteroploid and inbred relationships
Domesticated apple (Malus x domestica Borkh.) is a major global crop and the genetic diversity held within the pool of cultivated varieties is important for the development of future cultivars. The aim of this study was to investigate the diversity held within the domesticated form, through the analysis of a major international germplasm collection of cultivated varieties, the UK National Fruit Collection, consisting of over 2,000 selections of named cultivars and seedling varieties. We utilised Diversity Array Technology (DArT) markers to assess the genetic diversity within the collection. Clustering attempts, using the software STRUCTURE revealed that the accessions formed a complex and historically admixed group for which clear clustering was challenging. Comparison of accessions using the Jaccard similarity coefficient allowed us to identify clonal and duplicate material as well as revealing pairs and groups that appeared more closely related than a standard parent-offspring or full-sibling relations. From further investigation, we were able to propose a number of new pedigrees, which revealed that some historically important cultivars were more closely related than previously documented and that some of them were partially inbred. We were also able to elucidate a number of parent-offspring relationships that had resulted in a number of important polyploid cultivars. This included reuniting polyploid cultivars that in some cases dated as far back as the 18th century, with diploid parents that potentially date back as far as the 13th century
photoproduction on the proton for photon energies from 0.725 to 2.875 GeV
Differential cross sections for the reaction have been
measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged
photon beam with energies from 0.725 to 2.875 GeV. Where available, the results
obtained here compare well with previously published results for the reaction.
Agreement with the SAID and MAID analyses is found below 1 GeV. The present set
of cross sections has been incorporated into the SAID database, and exploratory
fits have been made up to 2.7 GeV. Resonance couplings have been extracted and
compared to previous determinations. With the addition of these cross sections
to the world data set, significant changes have occurred in the high-energy
behavior of the SAID cross-section predictions and amplitudes.Comment: 18 pages, 10 figure
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