197 research outputs found
Insights into the room temperature magnetism of ZnO/Co3O4 mixtures
The origin of room temperature (RT) ferromagneticlike behavior in ZnO-based
diluted magnetic semiconductors is still an unclear topic. The present work
concentrates on the appearance of RT magnetic moments in just mixed ZnO/Co3O4
mixtures without thermal treatment. In this study, it is shown that the
magnetism seems to be related to surface reduction of the Co3O4 nanoparticles,
in which, an antiferromagnetic Co3O4 nanoparticle (core) is surrounded by a
CoO-like shell. This singular superficial magnetism has also been found in
other mixtures with semiconductors such as TiO2 and insulators such as Al2O3
Enoxaparin does not ameliorate liver fibrosis or portal hypertension in rats with advanced cirrhosis
Background & Aims
Recent studies suggest that heparins reduce liver fibrosis and the risk of decompensation of liver disease. Here, we evaluated the effects of enoxaparin in several experimental models of advanced cirrhosis.
Methods
Cirrhosis was induced in male SpragueâDawley (SD) rats by: (i) Oral gavage with carbon tetrachloride (CCl4ORAL), (ii) Bile duct ligation (BDL) and (iii) CCl4 inhalation (CCl4INH). Rats received saline or enoxaparin s.c. (40 IU/Kg/d or 180 IU/Kg/d) following various protocols. Blood biochemical parameters, liver fibrosis, endotheliumâ and fibrosisârelated genes, portal pressure, splenomegaly, bacterial translocation, systemic inflammation and survival were evaluated. Endothelial dysfunction was assessed by in situ bivascular liver perfusions.
Results
Enoxaparin did not ameliorate liver function, liver fibrosis, profibrogenic gene expression, portal hypertension, splenomegaly, ascites development and infection, serum ILâ6 levels or survival in rats with CCl4ORAL or BDLâinduced cirrhosis. Contrarily, enoxaparin worsened portal pressure in BDL rats and decreased survival in CCl4ORAL rats. In CCl4INH rats, enoxaparin had no effects on hepatic endothelial dysfunction, except for correcting the hepatic arterial dysfunction when enoxaparin was started with the CCl4 exposure. In these rats, however, enoxaparin increased liver fibrosis and the absolute values of portal venous and sinusoidal resistance.
Conclusions
Our results do not support a role of enoxaparin for improving liver fibrosis, portal hypertension or endothelial dysfunction in active disease at advanced stages of cirrhosis. These diseaseârelated factors and the possibility of a limited therapeutic window should be considered in future studies evaluating the use of anticoagulants in cirrhosis
A Scoring System for Identifying Patients Likely to Be Diagnosed with Low-Grade Coeliac Enteropathy
Background & aims: Determining whether patients with lymphocytic enteritis (LE) have coeliac disease is a challenge. We analysed the variables associated with a low-grade coeliac enteropathy diagnosis in patients with suspected coeliac disease but without villous atrophy, and developed a scoring system to identify them. Methods: We collected data from 2010 through to 2016 on patients with lymphocytic enteritis and persistent symptoms compatible with the clinical spectrum of coeliac disease. One hundred and four patients starting on a gluten-free diet (GFD) were included. Duodenal biopsies were collected before the GFD and analysed for numbers of CD3+ T-cell receptor gamma delta+ (TCRγΎ+), and CD3- intraepithelial lymphocytes. We performed a logistic regression analysis to identify factors associated with a low-grade coeliac enteropathy diagnosis. Results: Sixty-two patients achieved clinical remission after the GFD. Fifty of these 62 patients were diagnosed with low-grade coeliac enteropathy. Multivariate analysis identified the presence of >25% intraepithelial lymphocytosis, HLA-DQ2.5, positive serology, and increased numbers of TCRγΎ+ cells with a low-grade coeliac enteropathy diagnosis. We developed a scoring system that identified patients with an area under the ROC curve (AUC) of 0.91. Scores of >10 had 86% sensitivity and 85% specificity. Conclusion: We developed a scoring system that identifies patients likely to be diagnosed with low-grade coeliac enteropathy with an AUC value of 0.91
Intestinal intraepithelial lymphocyte cytometric pattern is more accurate than subepithelial deposits of anti-tissue transglutaminase IgA for the diagnosis of celiac disease in lymphocytic enteritis
Background & Aims: An increase in CD3+TCRγΎ+ and a decrease in CD3â intraepithelial lymphocytes (IEL) is a characteristic flow cytometric pattern of celiac disease (CD) with atrophy. The aim was to evaluate the usefulness of both CD IEL cytometric pattern and anti-TG2 IgA subepithelial deposit analysis (CD IF pattern) for diagnosing lymphocytic enteritis due to CD. Methods: Two-hundred and five patients (144 females) who underwent duodenal biopsy for clinical suspicion of CD and positive celiac genetics were prospectively included. Fifty had villous atrophy, 70 lymphocytic enteritis, and 85 normal histology. Eight patients with non-celiac atrophy and 15 with lymphocytic enteritis secondary to Helicobacter pylori acted as control group. Duodenal biopsies were obtained to assess both CD IEL flow cytometric (complete or incomplete) and IF patterns. Results: Sensitivity of IF, and complete and incomplete cytometric patterns for CD diagnosis in patients with positive serology (Marsh 1+3) was 92%, 85 and 97% respectively, but only the complete cytometric pattern had 100% specificity. Twelve seropositive and 8 seronegative Marsh 1 patients had a CD diagnosis at inclusion or after gluten free-diet, respectively. CD cytometric pattern showed a better diagnostic performance than both IF pattern and serology for CD diagnosis in lymphocytic enteritis at baseline (95% vs 60% vs 60%, pâ=â0.039). Conclusions: Analysis of the IEL flow cytometric pattern is a fast, accurate method for identifying CD in the initial diagnostic biopsy of patients presenting with lymphocytic enteritis, even in seronegative patients, and seems to be better than anti-TG2 intestinal deposits
Plasma polyunsaturated fatty acid pattern in active inflammatory bowel disease
Plasma fatty acid patterns were assessed by gas liquid chromatography in 73 patients with active inflammatory bowel disease and 107 healthy controls. The influence of the disease activity on fatty acid profile was also investigated. Plasma fatty acid patterns in patients with ulcerative colitis and Crohn's disease were similar. Plasma C18:3n3 and C22:6n3 were significantly higher in active ulcerative colitis (p = 0.0143 and p < 0.00001 respectively) and in Crohn's disease (p < 0.00001 for both) than in controls, whereas C20:3n6 was significantly lower in patients than in controls, both in ulcerative colitis (p = 0.0001) and in Crohn's disease (p = 0.0041). In more severe disease, plasma polyunsaturated fatty acid concentrations fell with a significant stepwise decrease in the desaturation index (p = 0.0031 in ulcerative colitis and p = 0.0355 in Crohn's disease). Even in patients with severe disease, however, plasma n3 fatty acids (C18:3n3 and C22:6n3) never fell below those of healthy controls. These findings suggest that in active inflammatory bowel disease, an increased biosynthesis might coexist with an increased consumption of polyunsaturated fatty acids. These observations may be of relevance in the pathogenesis of the disease as polyunsaturated fatty acids are involved in tissue eicosanoid synthesis and cellular membrane function, including that of immunocompetent cells. These results also question the rationale of using n3 polyunsaturated fatty acids in the treatment of inflammatory bowel disease
Trade-offs among aboveground, belowground, and soil organic carbon stocks along altitudinal gradients in Andean tropical montane forests
Tropical montane forests (TMFs) play an important role as a carbon reservoir at a global scale. However, there is a lack of a comprehensive understanding on the variation in carbon storage across TMF compartments [namely aboveground biomass (AGB), belowground biomass (BGB), and soil organic matter] along altitudinal and environmental gradients and their potential trade-offs. This study aims to: 1) understand how carbon stocks vary along altitudinal gradients in Andean TMFs, and; 2) determine the influence of climate, particularly precipitation seasonality, on the distribution of carbon stocks across different forest compartments. The study was conducted in sixty 0.1 ha plots along two altitudinal gradients at the Podocarpus National Park (Ecuador) and RĂo Abiseo National Park (Peru). At each plot, we calculated the amount of carbon in AGB (i.e. aboveground carbon stock, AGC), BGB (i.e. belowground carbon stock, BGC), and soil organic matter (i.e. soil organic carbon stock, SOC). The mean total carbon stock was 244.76 ± 80.38 Mg haâ1 and 211.51 ± 46.95 Mg haâ1 in the Ecuadorian and Peruvian plots, respectively. Although AGC, BGC, and SOC showed different partitioning patterns along the altitudinal gradient both in Ecuador and Peru, total carbon stock did not change with altitude in either site. The combination of annual mean temperature and precipitation seasonality explained differences in the observed patterns of carbon stocks across forest compartments between the two sites. This study suggests that the greater precipitation seasonality of colder, higher altitudes may promote faster turnover rates of organic matter and nutrients and, consequently, less accumulation of SOC but greater AGC and BGC, compared to those sites with lesser precipitation seasonality. Our results demonstrate the capacity of TMFs to store substantial amounts of carbon and suggest the existence of a trade-off in carbon stocks among forest compartments, which could be partly driven by differences in precipitation seasonality, especially under the colder temperatures of high altitudesAuthorizations to work in protected areas were granted by national authorities: Ecuador (MAE-DNB-CM2015-0016) and PerĂș (001-2016-SERNANP-PNRA-JEF
Genetic variants of innate immunity receptors are associated with mortality in cirrhotic patients with bacterial infection
BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is characterized by acute decompensation of cirrhosis (AD), organ failure(s) and high risk of short-term mortality with bacterial infection frequently as precipitating event. Innate immune pattern recognition receptors and members of the lectin pathway of complement activation are crucial to the innate immune response to pathogens. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) of innate immune components are associated with the occurrence of bacterial infections or mortality in patients with cirrhosis hospitalized for AD or ACLF. METHODS: Twenty-one innate immunity SNPs with known functional implications were genotyped in 826 AD/ACLF patients included in the CANONIC study. Associations between baseline characteristics of the patients, the occurrence of bacterial infections and survival rate at 90 days of follow-up in relation to the innate immunity genetic variants were analysed. RESULTS: The NOD2-G908R genetic variant was associated with mortality (HR 2.25, P = .004) independently of age and MELD Score. This association was also found in a predefined subgroup analysis in patients with bacterial infections (HR 2.78, P < .001) along with MBL_Yx (HR 1.72, P = .008) and MASP2_371 (HR 1.67, P = .012) genetic variants. None of the analysed SNPs were significantly associated with the occurrence of acute bacterial infections or spontaneous bacterial peritonitis in particular. CONCLUSIONS: Innate immune system-specific NOD2-G908R, MBL_Yx and MASP2_371 genetic variants were independently associated with increased risk of short-term mortality in AD/ACLF patients with bacterial infection
Effects of an intensive lifestyle intervention program on portal hypertension in patients with cirrhosis and obesity: The sportdiet study
Obesity increases the risk of clinical decompensation in cirrhosis, possibly by increasing portal pressure. Whether weight reduction can be safely achieved through lifestyle (LS) changes (diet and exercise) in overweight/obese patients with cirrhosis, and if weight loss reduces portal pressure in this setting, is unknown. This prospective, multicentric, uncontrolled pilot study enrolled patients with compensated cirrhosis, portal hypertension (hepatic venous pressure gradient [HVPG] â„6 mm Hg), and body mass index (BMI) â„26 kg/m2 in an intensive 16âweek LS intervention program (personalized hypocaloric normoproteic diet and 60 min/wk of supervised physical activity). We measured HVPG, body weight (BW) and composition, adipokines, healthârelated quality of life, and safety data before and after the intervention. Changes in HVPG and BW were predefined as clinically relevant if â„10% and â„5%, respectively. Safety and BW were reassessed after 6 months. 60 patients were included and 50 completed the study (56 ± 8 years old; 62% male; nonalcoholic steatohepatitis etiology 24%; BMI 33.3 ± 3.2 kg/m2; Child A 92%; HVPG â„10 mm Hg, 72%). LS intervention significantly decreased BW (average, -5.0 ± 4.0 kg; P < 0.0001), by â„5% in 52% and â„10% in 16%. HVPG also significantly decreased (from 13.9 ± 5.6 to 12.3 ± 5.2 mm Hg; P < 0.0001), by â„10% in 42% and â„20% in 24%. A â„10% BW loss was associated with a greater decrease in HVPG (-23.7 ± 19.9% vs. -8.2 ± 16.6%; P = 0.024). No episodes of clinical decompensation occurred. Weight loss achieved at 16 weeks was maintained at 6 months; Child and Model for EndâStage Liver Disease scores did not change. Conclusion: Sixteen weeks of diet and moderate exercise were safe and reduced BW and portal pressure in overweight/obese patients with cirrhosis and portal hypertension
Rebleeding prophylaxis improves outcomes in patients with hepatocellular carcinoma. A multicenter case-control study
Outcome of variceal bleeding (VB) in patients with hepatocellular carcinoma (HCC) is unknown. We compared outcomes after VB in patients with and without HCC. All patients with HCC and esophageal VB admitted between 2007 and 2010 were included. Follow-up was prolonged until death, transplantation, or June 2011. For each patient with HCC, a patient without HCC matched by age and Child-Pugh class was selected. A total of 292 patients were included, 146 with HCC (Barcelona Classification of Liver Cancer class 0-3 patients, A [in 25], B [in 29], C [in 45], and D [in 41]) and 146 without HCC. No differences were observed regarding previous use of prophylaxis, clinical presentation, endoscopic findings, and initial endoscopic treatment. Five-day failure was similar (25% in HCC versus 18% in non-HCC; P = 0.257). HCC patients had greater 6-week rebleeding rate (16 versus 7%, respectively; P = 0.025) and 6-week mortality (30% versus 15%; P = 0.003). Fewer patients with HCC received secondary prophylaxis after bleeding (77% versus 89%; P = 0.009), and standard combination therapy was used less frequently (58% versus 70%; P = 0.079). Secondary prophylaxis failure was more frequent (50% versus 31%; P = 0.001) and survival significantly shorter in patients with HCC (median survival: 5 months versus greater than 38 months in patients without HCC; P < 0.001). Lack of prophylaxis increased rebleeding and mortality. On multivariate analysis Child-Pugh score, presence of HCC, portal vein thrombosis, and lack of secondary prophylaxis were predictors of death. Conclusions: Patients with HCC and VB have worse prognosis than patients with VB without HCC. Secondary prophylaxis offers survival benefit in HCC patient
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