1,127 research outputs found
Domain and Geometry Agnostic CNNs for Left Atrium Segmentation in 3D Ultrasound
Segmentation of the left atrium and deriving its size can help to predict and
detect various cardiovascular conditions. Automation of this process in 3D
Ultrasound image data is desirable, since manual delineations are
time-consuming, challenging and observer-dependent. Convolutional neural
networks have made improvements in computer vision and in medical image
analysis. They have successfully been applied to segmentation tasks and were
extended to work on volumetric data. In this paper we introduce a combined
deep-learning based approach on volumetric segmentation in Ultrasound
acquisitions with incorporation of prior knowledge about left atrial shape and
imaging device. The results show, that including a shape prior helps the domain
adaptation and the accuracy of segmentation is further increased with
adversarial learning
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Identification of a Hemolysis Threshold That Increases Plasma and Serum Zinc Concentration.
Background: Plasma or serum zinc concentration (PZC or SZC) is the primary measure of zinc status, but accurate sampling requires controlling for hemolysis to prevent leakage of zinc from erythrocytes. It is not established how much hemolysis can occur without changing PZC/SZC concentrations.Objective: This study determines a guideline for the level of hemolysis that can significantly elevate PZC/SZC.Methods: The effect of hemolysis on PZC/SZC was estimated by using standard hematologic variables and mineral content. The calculated hemolysis threshold was then compared with results from an in vitro study and a population survey. Hemolysis was assessed by hemoglobin and iron concentrations, direct spectrophotometry, and visual assessment of the plasma or serum. Zinc and iron concentrations were determined by inductively coupled plasma spectrometry.Results: A 5% increase in PZC/SZC was calculated to result from the lysis of 1.15% of the erythrocytes in whole blood, corresponding to ∼1 g hemoglobin/L added into the plasma or serum. Similarly, the addition of simulated hemolysate to control plasma in vitro caused a 5% increase in PZC when hemoglobin concentrations reached 1.18 ± 0.10 g/L. In addition, serum samples from a population nutritional survey were scored for hemolysis and analyzed for changes in SZC; samples with hemolysis in the range of 1-2.5 g hemoglobin/L showed an estimated increase in SZC of 6% compared with nonhemolyzed samples. Each approach indicated that a 5% increase in PZC/SZC occurs at ∼1 g hemoglobin/L in plasma or serum. This concentration of hemoglobin can be readily identified directly by chemical hemoglobin assays or indirectly by direct spectrophotometry or matching to a color scale.Conclusions: A threshold of 1 g hemoglobin/L is recommended for PZC/SZC measurements to avoid increases in zinc caused by hemolysis. The use of this threshold may improve zinc assessment for monitoring zinc status and nutritional interventions
In-vitro and in-vivo evaluation of the antistaphylococcal activity of S-5556, a new 16-membered macrolide
During recent years, a resurgence of interest in the macrolides had led to the discovery of new derivatives of erythromycin with improved antibacterial activity and pharmacokinetic properties. In this study the in-vitro and in-vivo antistaphylococcal activity of S-5556, a 16-membered macrolide, was evaluated. In vitro, S-5556 was slightly less active than erythromycin against methicillin-susceptible Staphylococcus aureus. In contrast, it had superior activity for methicillin-resistant S. aureus (MRSA); several of these strains with inducible resistance to the macrolides-lincosamides-streptogramins group were susceptible to S-5556 whereas erythromycin was inactive. The combination of S-5556 with oxatillin was synergic for most MRSA strains tested. In vivo, a single prophylactic dose of S-5556 prevented 75%-100% of the cases of acute staphylococcal subcutaneous foreign body infection in a guinea pig-model. In a rat-model of chronic implant infection due to a methicillin- and erythromycin-resistant S. aureus strain, S-5556 significantly decreased the bacteria] concentration around the foreign material, however resistant mutants emerge
Comparative in-vitro activity of new quinolones against clinical isolates and resistant mutants
The in-vitro activity of five new fluoroquinolones, WIN 57273, sparfloxacin, flerox-acin, temafloxacin and tiprofloxacin was determined against 543 recent clinical isolates and eight quinolone resistant strains derived by mutation and their five parent strains. WIN 57273 was the most active compound against Gram-positive bacteria, sparfloxacin had a broad spectrum which was similar to that of cipro-floxacin. Ciprofloxacin showed the greatest activity against Gram-negative bacteria. Temafloxacin showing some activity against Gram-positive organisms and Acinetobacter spp. Fleroxacin was the least active compound studied. Compared to wild type parent strains, the mutated strains produced the following results. In Enterobacter cloacae OmpF deficiency increased the MICs of all quinolones by 8-32-fold. In Pseudomonas aeruginosa OmpF deficiency had a limited effect, Omp D2 deficiency combined with an increased lipopolysaccharide content produced greater resistance, i.e. 4-16-fold; mutations in gyrase were associated with variously increased MICs, depending on the strain and compound teste
Comparative in-vitro activity of new quinolones against clinical isolates and resistant mutants
A Systematic Review and Metaanalysis on the Effects of Garlic Preparations on Blood Pressure in Individuals With Hypertension
BACKGROUND Many patients prefer herbal medications to conventional drugs. Limited trial evidence suggests that garlic preparations reduce high blood pressure (BP). METHODS We searched electronic databases through March 2014 to identify all randomized controlled trials that compared a garlic preparation to placebo in hypertensive patients. Trials were required to report BP values at baseline and after a follow-up of at least 4 weeks. RESULTS Nine double-blind trials with 482 individuals fulfilled our inclusion criteria. Included trials were rather small, and the quality of the majority of included trials was moderate. Follow-up ranged from 8 to 26 weeks. All trials reported office BP measurements. Systolic BP and diastolic BP (SBP and DBP) were more effectively reduced in individuals treated with garlic preparations than in individuals treated with placebo. However, heterogeneity was high (weighted mean difference (WMD) for SBP was −9.1mm Hg; 95% confidence interval (CI), −12.7 to −5.4; P for heterogeneity = 0.0006; and I 2 = 71%; WMD for BP was −3.8mm Hg; 95% CI, −6.7 to −1.0; P for heterogeneity = 0.00001; I 2 = 80%). When analyses were restricted to higher-quality trials using intention-to-treat analysis or to trials with concealed treatment allocation and standardized and blinded BP measurement, effect sizes for SBP but not for DBP were lower and heterogeneity disappeared. CONCLUSIONS Although evidence from this review suggests that garlic preparations may lower BP in hypertensive individuals, the evidence is not strong. A well-conducted and powered trial of longer duration is needed to confirm these finding
Hypothyroidism in rats decreases peripheral glucose utilisation, a defect partially corrected by central leptin infusion
Aims/hypothesis: The aims of this work were to determine the effect of hypothyroidism on insulin-stimulated glucose turnover and to unravel the potential mechanisms involved in such an effect. Methods: Hypothyroidism was induced by administration of propylthiouracil, with partial T4 substitution. Euglycaemic-hyperinsulinaemic clamps, associated with the labelled 2-deoxy-d-glucose technique for measuring tissue-specific glucose utilisation, were used. To assess a possible involvement of leptin in the modulation of glucose metabolism by hypothyroidism, leptin was infused intracerebroventricularly for 6 days. A group of leptin-infused rats was treated with rT3 to determine a potential role of T3 in mediating the leptin effects. Results: Compared with euthyroid rats, hypothyroid animals exhibited decreased overall glucose turnover and decreased glucose utilisation indices in skeletal muscle and adipose tissue. Leptinaemia in hypothyroid rats was lower while resistin mRNA expression in adipose tissue was higher than in euthyroid animals. Intracerebroventricular leptin infusion in hypothyroid rats partially restored overall, muscle and adipose tissue insulin-stimulated glucose utilisation and improved the reduced glycaemic response observed during insulin tolerance tests. The leptin effects were due neither to the observed increase in plasma T3 levels nor to changes in the high adipose tissue resistin expression of hypothyroid rats. The administration of leptin to hypothyroid animals was accompanied by increased expression of muscle and adipose tissue carnitine palmitoyl transferases, decreased plasma NEFA levels and reduced muscle triglyceride content. Conclusions/interpretation: Hypothyroidism is characterised by decreased insulin responsiveness, partly mediated by an exaggerated glucose-fatty acid cycle that is partly alleviated by intracerebroventricular leptin administratio
Study of peptide on-line complexation with transition-metal ions generated from sacrificial electrodes in thin-chip polymer microsprays
A miniaturized polymer electrospray-type interface is used to study metal-ion chelation with model peptides. Taking advantage of the intrinsic electrochemical behavior of electrospray, a sacrificial electrode is used to generate at the same time electrospray and transition-metal ions coming from the anodic dissolution of the electrode. The microspray interface provides enhanced mass transport due to its small dimensions, increasing the yield of possible reactions, in particular complex formation. Transition-metal electrodes, e.g. copper, zinc, nickel, iron and silver, are used to obtain on-line complexation with model peptides. It is demonstrated that the use of in-reservoir sacrificial electrodes is an efficient way to generate metal ions in order to form and study complexes with peptides, avoiding the addition of metallic salts
Peripheral, but not central, CB1 antagonism provides food intake-independent metabolic benefits in diet-induced obese rats.
OBJECTIVE
Blockade of the CB1 receptor is one of the promising strategies for the treatment of obesity. Although antagonists suppress food intake and reduce body weight, the role of central versus peripheral CB1 activation on weight loss and related metabolic parameters remains to be elucidated. We therefore specifically assessed and compared the respective potential relevance of central nervous system (CNS) versus peripheral CB1 receptors in the regulation of energy homeostasis and lipid and glucose metabolism in diet-induced obese (DIO) rats.
RESEARCH DESIGN AND METHODS
Both lean and DIO rats were used for our experiments. The expression of key enzymes involved in lipid metabolism was measured by real-time PCR, and euglycemic-hyperinsulinemic clamps were used for insulin sensitivity and glucose metabolism studies.
RESULTS
Specific CNS-CB1 blockade decreased body weight and food intake but, independent of those effects, had no beneficial influence on peripheral lipid and glucose metabolism. Peripheral treatment with CB1 antagonist (Rimonabant) also reduced food intake and body weight but, in addition, independently triggered lipid mobilization pathways in white adipose tissue and cellular glucose uptake. Insulin sensitivity and skeletal muscle glucose uptake were enhanced, while hepatic glucose production was decreased during peripheral infusion of the CB1 antagonist. However, these effects depended on the antagonist-elicited reduction of food intake.
CONCLUSIONS
Several relevant metabolic processes appear to independently benefit from peripheral blockade of CB1, while CNS-CB1 blockade alone predominantly affects food intake and body weight
SnBrP-A SnIP-type representative in the Sn-Br-P system
One-dimensional semiconductors are interesting materials due to their unique structural features and anisotropy, which grant them intriguing optical, dielectric and mechanical properties. In this work, we report on SnBrP, a lighter homologue of the first inorganic double helix compound SnIP. This class of compounds is characterized by intriguing mechanical and electronic properties, featuring a high flexibility without modulation of physical properties. Semiconducting SnBrP can be synthesized from red phosphorus, tin and tin(II)bromide at elevated temperatures and crystallizes as red-orange, cleavable needles. Raman measurements pointed towards a double helical building unit in SnBrP, showing similarities to the SnIP structure. After taking PL measurements, HR-TEM, and quantum chemical calculations into account, we were able to propose a sense full structure model for SnBrP
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