171 research outputs found
Barrett's esophagus : high cancer-risk groups, cardiovascular co-morbidity and interaction with Helicobacter pylori
Barrett's esophagus (BE) has come to be regarded as an impOliant
premalignant condition. In recent years the incidence of adenocarcinoma of the
esophagus and of the gastric cardia has risen dramatically. Analyses of cancer
incidence data fi'om nine areas of the United States revealed steadily rising rates of
adenocarcinomas of the esophagus and gastric cardia from 1976 to 1987. The
increases among men in this period ranged from 4% to 10% per year, and exceeded
those of any other type of cancer. The rate of esophageal adenocarcinoma in
Denmark has increased eightfold over a 20-yr period. In the Netherlands the rate
of cardiacarcinoma has increased 35%, and since the early 90's mainly (Barrett's
related) adenocarcinomas ofthe esophagus have been on the rise (Ph.D. thesis
"Adenocarcinoma of the gastro-oesophageal junction - From gene to clinic" pages
71-73, B.P.L Wijnhoven, 2001). The reasons for this alarming rise are not clear but
many believe it to be a consequence of gastroesophageal-reflux disease (GERD) and
BE. This has led to an increased interest in research on BE and GERD
Elucidating the Binding Mechanism of a Novel Silica-Binding Peptide.
Linker-protein G (LPG) is a bifunctional fusion protein composed of a solid-binding peptide (SBP, referred as the "linker") with high affinity to silica-based compounds and a Streptococcus protein G (PG), which binds antibodies. The binding mechanisms of LPG to silica-based materials was studied using different biophysical techniques and compared to that of PG without the linker. LPG displayed high binding affinity to a silica surface (KD = 34.77 ± 11.8 nM), with a vertical orientation, in comparison to parent PG, which exhibited no measurable binding affinity. Incorporation of the linker in the fusion protein, LPG, had no effect on the antibody-binding function of PG, which retained its secondary structure and displayed no alteration of its chemical stability. The LPG system provided a milder, easier, and faster affinity-driven immobilization of antibodies to inorganic surfaces when compared to traditional chemical coupling techniques
Hypertension is frequently present in patients with reflux esophagitis or Barrett's esophagus but not in those with non-ulcer dyspepsia
Background: Elevated mortality due to cardiovascular disease has been reported for patients with Barrett's esophagus (BE). We compared the prevalence of risk factors for cardiovascular disease in patients with BE, reflux esophagitis (RE), and non-ulcer dyspepsia (NUD) with that of the general population. Methods: Patients with upper gastrointestinal complaints and BE, RE, or NUD were compared with a matched cohort from the general population using a questionnaire and blood pressure and cholesterol measurements. Results: Hypertension occurred more frequently in patients with BE (odds ratio 5.1, P<0.0001) and RE (odds ratio 3.8, P<0.001), but not in those with NUD. Serum total cholesterol was higher in BE (P=0.02) and borderline in RE (P=0.06) but not in NUD. Mean HDL cholesterol levels, body mass index, and smoking did not differ. Conclusions: This study suggests that BE and RE found at diagnostic endoscopy are associated with an increased prevalence of hypertension and a higher total cholesterol level than in the general population. If so, this would explain the increased mortality during the follow-up of BE patients, and it should be taken into account when designing or evaluating follow-up studies of BE
Purification and preliminary characterization of a xylanase from Thermomyces lanuginosus strain SS-8
Thermomyces lanuginosus SS-8 was isolated from soil samples that had been collected from near self-heating plant material and its extracellular cellulase-free xylanase purified approximately 160-fold using ion exchange chromatography and continuous elution electrophoresis. This xylanase was thermoactive (optimum temperature 60 °C) at pH 6.0 and had a molecular weight of 23.79 kDa as indicated by SDS-PAGE electrophoresis. The xylanase rapidly hydrolyzed xylan directly to xylose without the production of intermediary xylo-oligosaccharides within 15 min of incubation under optimum conditions. This trait of rapidly degrading xylan to xylose as a sole end-product could have biotechnological potential in degradation of agro-wastes for bioethanol manufacturing industry
Imprint of Climate Change on Pan-Arctic Marine Vegetation
The Arctic climate is changing rapidly. The warming and resultant longer open water periods suggest a potential for expansion of marine vegetation along the vast Arctic coastline. We compiled and reviewed the scattered time series on Arctic marine vegetation and explored trends for macroalgae and eelgrass (Zostera marina). We identified a total of 38 sites, distributed between Arctic coastal regions in Alaska, Canada, Greenland, Iceland, Norway/Svalbard, and Russia, having time series extending into the 21st Century. The majority of these exhibited increase in abundance, productivity or species richness, and/or expansion of geographical distribution limits, several time series showed no significant trend. Only four time series displayed a negative trend, largely due to urchin grazing or increased turbidity. Overall, the observations support with medium confidence (i.e., 5–8 in 10 chance of being correct, adopting the IPCC confidence scale) the prediction that macrophytes are expanding in the Arctic. Species distribution modeling was challenged by limited observations and lack of information on substrate, but suggested a current (2000–2017) potential pan-Arctic macroalgal distribution area of 820.000 km2 (145.000 km2 intertidal, 675.000 km2 subtidal), representing an increase of about 30% for subtidal- and 6% for intertidal macroalgae since 1940–1950, and associated polar migration rates averaging 18–23 km decade–1. Adjusting the potential macroalgal distribution area by the fraction of shores represented by cliffs halves the estimate (412,634 km2). Warming and reduced sea ice cover along the Arctic coastlines are expected to stimulate further expansion of marine vegetation from boreal latitudes. The changes likely affect the functioning of coastal Arctic ecosystems because of the vegetation’s roles as habitat, and for carbon and nutrient cycling and storage. We encourage a pan-Arctic science- and management agenda to incorporate marine vegetation into a coherent understanding of Arctic changes by quantifying distribution and status beyond the scattered studies now available to develop sustainable management strategies for these important ecosystems.publishedVersio
Fish Oil-Derived Fatty Acids in Pregnancy and Wheeze and Asthma in Offspring
© 2016 Massachusetts Medical Society. Bisgaard, H., Stokholm, J., Chawes, B. L., Vissing, N. H., Bjarnadóttir, E., Schoos, A.-M. M., … Bønnelykke, K. (2016). Fish Oil–Derived Fatty Acids in Pregnancy and Wheeze and Asthma in Offspring. New England Journal of Medicine, 375(26), 2530–2539. https://doi.org/10.1056/NEJMoa1503734BACKGROUND Reduced intake of n-3 long-chain polyunsaturated fatty acids (LCPUFAs) may be a contributing factor to the increasing prevalence of wheezing disorders. We assessed the effect of supplementation with n-3 LCPUFAs in pregnant women on the risk of persistent wheeze and asthma in their offspring. METHODS We randomly assigned 736 pregnant women at 24 weeks of gestation to receive 2.4 g of n-3 LCPUFA (fish oil) or placebo (olive oil) per day. Their children formed the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC 2010) cohort and were followed prospectively with extensive clinical phenotyping. Neither the investigators nor the participants were aware of group assignments during follow-up for the first 3 years of the children's lives, after which there was a 2-year follow-up period during which only the investigators were unaware of group assignments. The primary end point was persistent wheeze or asthma, and the secondary end points included lower respiratory tract infections, asthma exacerbations, eczema, and allergic sensitization. RESULTS A total of 695 children were included in the trial, and 95.5% completed the 3-year, double-blind follow-up period. The risk of persistent wheeze or asthma in the treatment group was 16.9%, versus 23.7% in the control group (hazard ratio, 0.69; 95% confidence interval [CI], 0.49 to 0.97; P=0.035), corresponding to a relative reduction of 30.7%. Prespecified subgroup analyses suggested that the effect was strongest in the children of women whose blood levels of eicosapentaenoic acid and docosahexaenoic acid were in the lowest third of the trial population at randomization: 17.5% versus 34.1% (hazard ratio, 0.46; 95% CI, 0.25 to 0.83; P=0.011). Analyses of secondary end points showed that supplementation with n-3 LCPUFA was associated with a reduced risk of infections of the lower respiratory tract (31.7% vs. 39.1%; hazard ratio, 0.75; 95% CI, 0.58 to 0.98; P=0.033), but there was no statistically significant association between supplementation and asthma exacerbations, eczema, or allergic sensitization. CONCLUSIONS Supplementation with n-3 LCPUFA in the third trimester of pregnancy reduced the absolute risk of persistent wheeze or asthma and infections of the lower respiratory tract in offspring by approximately 7 percentage points, or one third. (Funded by the Lund-beck Foundation and others; ClinicalTrials.gov number, NCT00798226.)Lundbeck Foundatio
A sequence variant associating with educational attainment also affects childhood cognition
Only a few common variants in the sequence of the genome have been shown to impact cognitive traits. Here we demonstrate that polygenic scores of educational attainment predict specific aspects of childhood cognition, as measured with IQ. Recently, three sequence variants were shown to associate with educational attainment, a confluence phenotype of genetic and environmental factors contributing to academic success. We show that one of these variants associating with educational attainment, rs4851266-T, also associates with Verbal IQ in dyslexic children (P=4.3 x 10(-4), beta=0.16 s.d.). The effect of 0.16 s.d. corresponds to 1.4 IQ points for heterozygotes and 2.8 IQ points for homozygotes. We verified this association in independent samples consisting of adults (P=8.3 x 10(-5), beta=0.12 s.d., combined P=2.2 x 10(-7), beta=0.14 s.d.). Childhood cognition is unlikely to be affected by education attained later in life, and the variant explains a greater fraction of the variance in verbal IQ than in educational attainment (0.7% vs 0.12%,. P=1.0 x 10(-5))
A sequence variant associating with educational attainment also affects childhood cognition
Only a few common variants in the sequence of the genome have been shown to impact cognitive traits. Here we demonstrate that polygenic scores of educational attainment predict specific aspects of childhood cognition, as measured with IQ. Recently, three sequence variants were shown to associate with educational attainment, a confluence phenotype of genetic and environmental factors contributing to academic success. We show that one of these variants associating with educational attainment, rs4851266-T, also associates with Verbal IQ in dyslexic children (P=4.3 x 10(-4), beta=0.16 s.d.). The effect of 0.16 s.d. corresponds to 1.4 IQ points for heterozygotes and 2.8 IQ points for homozygotes. We verified this association in independent samples consisting of adults (P=8.3 x 10(-5), beta=0.12 s.d., combined P=2.2 x 10(-7), beta=0.14 s.d.). Childhood cognition is unlikely to be affected by education attained later in life, and the variant explains a greater fraction of the variance in verbal IQ than in educational attainment (0.7% vs 0.12%,. P=1.0 x 10(-5))
Solid-binding peptides for immobilisation of thermostable enzymes to hydrolyse biomass polysaccharides
Deciphering ligand specificity of a Clostridium thermocellum family 35 carbohydrate binding module (CtCBM35) for Gluco- and Galacto- Substituted mannans and Its calcium induced stability
Articles in International JournalsThis study investigated the role of CBM35 from Clostridium thermocellum (CtCBM35) in polysaccharide recognition. CtCBM35 was cloned into pET28a (+) vector with an engineered His6 tag and expressed in Escherichia coli BL21 (DE3) cells. A homogenous 15 kDa protein was purified by immobilized metal ion chromatography (IMAC). Ligand binding analysis of CtCBM35 was carried out by affinity electrophoresis using various soluble ligands. CtCBM35 showed a manno-configured ligand specific binding displaying significant association with konjac glucomannan (Ka = 14.3×104 M−1), carob galactomannan (Ka = 12.4×104 M−1) and negligible association (Ka = 12 µM−1) with insoluble mannan. Binding of CtCBM35 with polysaccharides which was calcium dependent exhibited two fold higher association in presence of 10 mM Ca2+ ion with konjac glucomannan (Ka = 41×104 M−1) and carob galactomannan (Ka = 30×104 M−1). The polysaccharide binding was further investigated by fluorescence spectrophotometric studies. On binding with carob galactomannan and konjac glucomannan the conformation of CtCBM35 changed significantly with regular 21 nm peak shifts towards lower quantum yield. The degree of association (Ka) with konjac glucomannan and carob galactomannan, 14.3×104 M−1 and 11.4×104 M−1, respectively, corroborated the findings from affinity electrophoresis. The association of CtCBM35with konjac glucomannan led to higher free energy of binding (ΔG) −25 kJ mole−1 as compared to carob galactomannan (ΔG) −22 kJ mole−1. On binding CtCBM35 with konjac glucomannan and carob galactomannan the hydrodynamic radius (RH) as analysed by dynamic light scattering (DLS) study, increased to 8 nm and 6 nm, respectively, from 4.25 nm in absence of ligand. The presence of 10 mM Ca2+ ions imparted stiffer orientation of CtCBM35 particles with increased RH of 4.52 nm. Due to such stiffer orientation CtCBM35 became more thermostable and its melting temperature was shifted to 70°C from initial 50°C
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