2,931 research outputs found
Correlation of Helicobacter pylori genotypes with gastric histopathology in the central region of a South-European country
BACKGROUND:
Outcome of Helicobacter pylori (H. pylori) infection results from interaction of multiple variables including host, environmental and bacterial-associated virulence factors.
AIM:
This study aimed to investigate the correlation of cagA, cagE, vacA, iceA and babA2 genotypes with gastric histopathology and disease phenotype in the central region of a South-European country.
METHODS:
This prospective study involved 148 infected patients (110 female; mean age 43.5 ± 13.4 years) submitted to endoscopy with corpus and antrum biopsies. H. pylori was cultured and DNA extracted from the isolates. Genotypes were determined by PCR. Histopathological features were graded according to the updated Sydney system and OLGA/OLGIM classification. Only patients with single H. pylori genotypes and complete histopathological results were included.
RESULTS:
Antrum samples presented higher degrees of atrophy, intestinal metaplasia, chronic inflammation and neutrophil activity. Genotype distribution was as follows: cagA-31.8 %; cagE-45.9 %; vacA s1a-24.3 %; vacA s1b-19.6 %; vacA s1c-0.7 %; vacA s2-55.4 %; vacA m1-20.9 %; vacA m2-79.1 %; vacA s1m1-18.9 %; vacA s1m2-25.7 %; vacA s2m1-2 %; vacA s2m2-53.4 %; iceA1-33.8 %; iceA2-66.2 %; babA2-12.2 %. CagA genotype was significantly associated with higher degrees of intestinal metaplasia, neutrophil activity, chronic inflammation and OLGIM stages. BabA2 was linked with higher H. pylori density. Strains with vacA s1m1 or vacA s1m1 + cagA positive genotypes had a significant association with peptic ulcer and vacA s2m2 with iron-deficient anemia.
CONCLUSIONS:
cagA, vacA s1m1 and babA2 genotypes are relatively rare in the central region of Portugal. cagA-positive strains are correlated with more severe histopathological modifications. This gene is commonly associated with vacA s1m1, and such isolates are frequently found in patients with peptic ulcer.info:eu-repo/semantics/publishedVersio
Anemia grave como apresentação de linfoma T Angioimunoblástico : um caso clínico
Introdução: O linfoma T Angioimunoblástico é uma entidade rara, que representa 1 a 2% dos linfomas não Hodgkin, com envolvimento sistémico associado a fenómenos auto-imunes.1,2 Caracteriza-se por um comportamento agressivo e clinicamente por uma apresentação súbita de sintomas constitucionais, adenomegálias generalizadas, hepatoesplenomegália, anemia e hipergamaglobulinemia.2
Objetivos: Partilhar apresentação de um caso clínico de Linfoma T Angioimunoblástico e suas particularidades transfusionais.
Métodos: Observação, exame objectivo e recolha de história clínica junto da doente. Consulta de registos clínicos no programa Sorian e recolha de dados analíticos relevantes nos programas WebAppolo, ASIS e registos de estudos pré-transfusionais realizados no SSMT. Recolha de dados, telefonicamente, junto do IPST, relativamente aos estudos pré-transfusionais realizados no mesmo.
Resultados: Doente do sexo feminino, 72 anos, autónoma, sem antecedentes transfusionais, apresentava em consulta de ambulatório queixas de dor abdominal difusa, com três dias de evolução, sem alterações do trânsito intestinal. Exame objectivo sem alterações relevantes. Analiticamente apresentava Hb 11.1 g/dL. Realizou TC abdominal que mostrou “expressão quística parapiélica bilateral, adenomegálias ileo-pélvicas, pequenas adenopatias periaórticas e densificação retroperitoneal”.
Duas semanas mais tarde inicia quadro de cansaço para pequenos esforços, associado a anorexia, perda de peso e palidez cutânea, pelo que recorre ao Serviço de Urgência. Apresentava-se hemodinamicamente estável, pálida, com sudorese, apirética, polipneica. Sat O2-97% com 2L/min de O2. Ligeira dor à palpação abdominal nos quadrantes inferiores, sem defesa. Analiticamente: Hb 3.1 g/dL normocitica/normocrómica. Não reunia critérios de anemia hemolítica.
Foram requisitadas duas Unidades (U) de Concentrado Eritrocitário (CE). No estudo pré-transfusional, método em gel, encontrou-se: PAI positiva – Poliaglutinação (3+) tanto em meio de LISS/Coombs como enzimático. TAD positivo (Poliespecífico 4+; Monoespecíficos - IgG 4+; IgM 3+; C3c 3+; C3d 4+; Título de IgG 1:100); Provas de compatibilidade (PC), com várias unidades de CE, positivas (de pelo menos 2+) . Foi decidido protelar a transfusão por estabilidade hemodinâmica da doente.
No dia seguinte por valor de Hb 2.6g/dL e agravamento do estado clínico, realizou, após administração de Hidrocortisona 200 mg e Clemastina 2mg, transfusão de 1 U de CE compatibilizada no IPST (PC positiva 1+, método em tubo). A transfusão decorreu sem intercorrências, no controlo pós-transfusional (CPT) - Hb 4.0g/dL, com melhoria franca da sintomatologia.
Inicia corticoterapia (Prednisolona 1 mg/Kg/dia).
Foi de novo transfundida dois dias mais tarde, Hb 3,7 g/dL, tendo sido enviada Unidade do (1U CE - IPST - PC negativa) . Não se registaram intercorrências, CPT - Hb 5.4g/dL.
Após 8 dias de Internamento, e a realização de diversos MCDTs foi diagnosticado um Linfoma T Angioimunoblástico.
Conclusão: O Linfoma T Angioimunoblástico pode apresentar-se com um quadro clínico inicial de anemia grave, de instalação rápida, que pelas suas características imunologicas, pode obrigar ao adiamento da transfusão.
REFERÊNCIAS BIBLIOGRÁFICAS
1- Zão, I., Dias, M., Castro, M., Coutinho, R., Cabral, R., Regadas, L., Casais, C., Xavier, L., Gonçalves, C., Mota, A., Pinho, L., Coutinho, J., . Manifestações auto-imunes do linfoma T angioimunoblástico . , 2017, Reunião Anual SPH, PO47
2- Xu, B., Liu. P., No Survival Improvement for Patients with Angioimmunoblastic T-Cell Lymphoma over the Past Two Decades: A Population-Based Study of 1207 Cases, 2014, PLOS ONE, Volume 9, Issue 3; e92585info:eu-repo/semantics/publishedVersio
Deposition and passage of transthyretin through the blood-nerve barrier in recipients of familial amyloid polyneuropathy livers
Familial amyloid polyneuropathy (FAP) is characterized by deposition of mutated transthyretin (TTR) in the peripheral nervous system. Prior to amyloid fibrils, nonfibrillar TTR aggregates are deposited inducing oxidative stress with increased nitration (3-NT). As the major source of TTR is the liver, liver transplantation (LT) is used to halt FAP. Given the shortage of liver donors, domino LT (DLT) using FAP livers is performed. The correlation between TTR deposition in the skin and nerve was tested in biopsies from normal individuals, asymptomatic carriers (FAP 0) and FAP patients; in FAP 0, nonfibrillar TTR was observed both in the skin and nerve in the same individuals; in patients, amyloid was detected in both tissues. The occurrence of amyloidosis in recipients of FAP livers was evaluated 1-7 years after DLT: TTR deposition occurred in the skin 3 years after transplantation either as amyloid or aggregates; in one of the recipients, fibrillar TTR was present in the epineurium 6 years after DLT. Deposits were scarce and 3-NT immunostaining was irrelevant. Nerve biopsies from DLT recipients had no FAP-related neuropathy. Our findings suggest that TTR amyloid formation occurs faster than predicted and that TTR of liver origin can cross the blood-nerve barrier. Recipients of FAP livers should be under surveillance for TTR deposition and tissue damag
Neuroprotection in a Novel Mouse Model of Multiple Sclerosis
The authors acknowledge the support of the Barts and the London Charity, the Multiple Sclerosis Society of Great Britain and Northern Ireland, the National Multiple Sclerosis Society, USA, notably the National Centre for the Replacement, Refinement & Reduction of Animals in Research, and the Wellcome Trust (grant no. 092539 to ZA). The siRNA was provided by Quark Pharmaceuticals. The funders and Quark Pharmaceuticals had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Vibrational analysis of d-PCL(530)/siloxane based hybrids doped with two lithium salts
Published online: 22 May 2013The present study has been focused on environmentally friendly sol-gel derived electrolytes based on a di-urethane cross-linked d-PCL(530)/siloxane network (where d represents di, PCL identifies the poly(ε–caprolactone) biopolymer and 530 is the average molecular weight in g.mol-1) doped with a wide range of concentration of lithium perchlorate (LiClO4) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Fourier Transform Infrared and Raman (FT-IR and FT-Raman, respectively) spectroscopies have been applied to evaluate the extent of ionic association. Characteristic bands of the PCL(530) segments, of the urethane cross-links and of the anions have been examined to gain insight into the cation/biopolymer, cation/anion and cation/cross-link interactions. In both electrolyte systems “free” ions and contact ions have been identified. The addition of salt modifies the hydrogen-bonded array of the host matrix, causing the destruction/formation of the urethane/urethane aggregates.Fundação para a Ciência e a Tecnologia (FCT
Magnetism and its microscopic origin in iron-based high-temperature superconductors
High-temperature superconductivity in the iron-based materials emerges from,
or sometimes coexists with, their metallic or insulating parent compound
states. This is surprising since these undoped states display dramatically
different antiferromagnetic (AF) spin arrangements and Nel
temperatures. Although there is general consensus that magnetic interactions
are important for superconductivity, much is still unknown concerning the
microscopic origin of the magnetic states. In this review, progress in this
area is summarized, focusing on recent experimental and theoretical results and
discussing their microscopic implications. It is concluded that the parent
compounds are in a state that is more complex than implied by a simple Fermi
surface nesting scenario, and a dual description including both itinerant and
localized degrees of freedom is needed to properly describe these fascinating
materials.Comment: 14 pages, 4 figures, Review article, accepted for publication in
Nature Physic
On a smoothed penalty-based algorithm for global optimization
This paper presents a coercive smoothed penalty framework for nonsmooth and nonconvex constrained global optimization problems. The properties of the smoothed penalty function are derived. Convergence to an ε -global minimizer is proved. At each iteration k, the framework requires the ε(k) -global minimizer of a subproblem, where ε(k)→ε . We show that the subproblem may be solved by well-known stochastic metaheuristics, as well as by the artificial fish swarm (AFS) algorithm. In the limit, the AFS algorithm convergence to an ε(k) -global minimum of the real-valued smoothed penalty function is guaranteed with probability one, using the limiting behavior of Markov chains. In this context, we show that the transition probability of the Markov chain produced by the AFS algorithm, when generating a population where the best fitness is in the ε(k)-neighborhood of the global minimum, is one when this property holds in the current population, and is strictly bounded from zero when the property does not hold. Preliminary numerical experiments show that the presented penalty algorithm based on the coercive smoothed penalty gives very competitive results when compared with other penalty-based methods.The authors would like to thank two anonymous referees for their valuable comments and
suggestions to improve the paper.
This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT
- Fundac¸ao para a Ci ˜ encia e Tecnologia within the projects UID/CEC/00319/2013 and ˆ
UID/MAT/00013/2013.info:eu-repo/semantics/publishedVersio
The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii
Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13)C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13)C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2), C(3) and C(4). The incorporation of [U-(14)C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal Grant PTDC/AGR-ALI/102608/2008 and by project FCOMP-01-0124-FEDER- 007047 and by FEDER through POFC - COMPETE and national funds from FCT - project PEst-C/BIA/UI4050/2011. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
The effect of agitation speed, enzyme loading and substrate concentration on enzymatic hydrolysis of cellulose from brewer’s spent grain
Brewer’s spent grain components (cellulose,
hemicellulose and lignin) were fractionated in a
two-step chemical pretreatment process using dilute
sulfuric acid and sodium hydroxide solutions. The
cellulose pulp produced was hydrolyzed with a
cellulolytic complex, Celluclast 1.5 L, at 45 ºC to
convert the cellulose into glucose. Several conditions
were examined: agitation speed (100, 150 and
200 rpm), enzyme loading (5, 25 and 45 FPU/g
substrate), and substrate concentration (2, 5 and 8%
w/v), according to a 2 3 full factorial design aiming to
maximize the glucose yield. The obtained results
were interpreted by analysis of variance and response
surface methodology. The optimal conditions for
enzymatic hydrolysis of brewer’s spent grain were
identified as 100 rpm, 45 FPU/g and 2% w/v substrate.
Under these conditions, a glucose yield of
93.1% and a cellulose conversion (into glucose and
cellobiose) of 99.4% was achieved. The easiness of
glucose release from BSG makes this substrate a raw material with great potential to be used in bioconversion
processes.Coordenação de Aperfeiçoamento de Pessoal de Nível
Superior (CAPES)Fundação de Amparo
à Pesquisa do Estado de São Paulo), Brazil. Novozymes ( FAPESP )Conselho Nacional de Desenvolvimento
Científico e Tecnológico (CNPq
Validation of Blood Gas Analysis in Arteriovenous Fistula for Hemodialysis
Introduction: Arterial blood gas analysis is a minimally invasive technique used in our daily practice but is not a complication free technique. The aim of this study was to validate results from blood gas analysis obtained from the arteriovenous fistula (AVF)/graft as a surrogate marker of the arterial blood gas analysis.
Methods: A prospective observational study was made in 45 patients. We performed arterial and AVF/graft blood gas analysis and results were compared by a paired sample t Student test.
Results: Most of our subjects was male (68.9%) and the mean age was 67 years (±14). Hemodialysis vintage was 63 months (±66), and vascular access age was 62 months (±56). The more prevalent vascular access was left radiocephalic AVF (n = 16; 35.6%) and the main puncture artery was right radial artery (n = 27; 60.0%). There were no statistically significant differences between the samples collected.
Conclusions: Our results suggest a possible alternative of arterial blood gas analysis in AVF/graft for hemodialysis patients. This could result in making an uncomfortable procedure almost painless and reducing complications. Future research should take place to include anatomical characteristics of the AVF or the circulation of recirculation.info:eu-repo/semantics/publishedVersio
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