53 research outputs found
Stepwise Catalytic Mechanism via Short-Lived Intermediate Inferred from Combined QM/MM MERP and PES Calculations on Retaining Glycosyltransferase ppGalNAcT2
The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi). The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals
Aspects epidemio-clinique et therapeutique de la maladie veineuse thromboembolique A lâInstitut de Cardiologie dâAbidjan
Objectif : Le but de cette Ă©tude Ă©tait de dĂ©crire les aspects Ă©pidĂ©miologique, clinique et thĂ©rapeutique de la maladie thromboembolique veineuse Ă lâInstitut de Cardiologie dâAbidjan.
Patients et mĂ©thodes. Il sâagissait dâune Ă©tude rĂ©trospective monocentrique, Ă visĂ©e descriptive et analytique concernant les patients consĂ©cutifs hospitalisĂ©s Ă lâInstitut de Cardiologie dâAbidjan pour thrombose veineuse profonde des membres infĂ©rieurs et/ou embolie pulmonaire durant la pĂ©riode du 1er janvier 2006 au 31 dĂ©cembre 2016 documentĂ©es par un Ă©chodoppler veineux et/ou un angioscanner pulmonaire.
RĂ©sultats. La prĂ©valence de la maladie thromboembolique veineuse a Ă©tĂ© estimĂ©e Ă 5,4 % des patients hospitalisĂ©s. La thrombose veineuse profonde des membres infĂ©rieurs et Lâembolie pulmonaire (EP) Ă©taient isolĂ©es respectivement dans 60,6% et 25,6% des cas, et lâassociation embolie pulmonaire et thrombose veineuse profonde des membres Ă©tait de 13,8%. LâĂąge moyen des patients Ă©tait 50,26 ans ±16,15 avec des extrĂȘmes Ă 17 ans et Ă 93 ans. Le sexe fĂ©minin Ă©tait prĂ©dominant (53,6%, sexe ratio (H/F) Ă 0,87). Au moins un facteur de risque de la maladie thrombo-embolique Ă©tait retrouvĂ© dans 85,4% des cas. Lâalitement prolongĂ© (31,2%) et lâobĂ©sitĂ© (26,2%) Ă©taient les facteurs de risque thrombotique majeurs. Les facteurs de risque nĂ©oplasique et gynĂ©co-obstĂ©trical reprĂ©sentaient respectivement 9,2% et 3,2%, les facteurs post-chirurgicaux 9,2%, lâinfection Ă VIH 13,6% et 5 cas de dĂ©ficit en antithrombine III (1%). Dans 14,6% des cas, aucun facteur de risque nâa Ă©tĂ© mis en Ă©vidence. Les thromboses veineuses profondes Ă©taient majoritairement localisĂ©es au membre infĂ©rieur gauche (65,7%) et de siĂšge proximal (70%), les embolies pulmonaires Ă©taient le plus souvent proximales (82,8%). Les AVK Ă©taient la classe thĂ©rapeutique la plus prescrite Ă la sortie des patients (89%) suivis des anticoagulants oraux directs (8,6 %) avec cependant une augmentation progressive de cette derniĂšre classe aux files du temps. La durĂ©e moyenne du traitement anticoagulant Ă©tait de 11,06 ± 6,75 mois.
Conclusion. La maladie thromboembolique veineuse est frĂ©quemment rencontrĂ©e et diagnostiquĂ©e. Elle est associĂ©e Ă des facteurs de risque qui mĂ©ritent dâĂȘtre pris en compte pour une prise en charge adĂ©quate. Le traitement repose sur lâutilisation en grande majoritĂ© des antivitamines K dans notre contexte avec cependant une augmentation progressive des anticoagulants oraux directs.
Mots-clés. Maladie thromboembolique veineuse, épidémiologie, diagnostic, anticoagulants, Institut de Cardiologie Abidjan.
Objective. The aim of this study was to describe the epidemiological, clinical and therapeutic aspects of venous thromboembolic disease at the Abidjan Cardiology Institute.
Patients and methods. This was a monocentric, descriptive and analytical retrospective study of consecutive patients hospitalized at the Abidjan Cardiology Institute for deep vein thrombosis of the lower limbs and/or pulmonary embolism during the period from January 1st 2006 to December 31th 2016 documented by a venous echodoppler and/or pulmonary angio-scanner.
Results. The prevalence of venous thromboembolic disease was estimated at 5.4% of hospitalized patients. Deep vein thrombosis of the lower limbs and pulmonary embolism (PE) were isolated in 60.6% and 25.6% of cases respectively, and the association of pulmonary embolism and deep vein thrombosis of the limbs was 13.8%. The average age of the patients was 50.26 years ±16.15 with extremes at 17 years and 93 years. The female sex was predominant (53.6%, sex ratio (H/F) to 0.87). At least one risk factor for thromboembolic disease was found in 85.4% of cases. Bed rest (31.2%) and obesity (26.2%) were the major thrombotic risk factors. Neoplasia and gyneco-obstetric risk factors accounted for 9.2% and 3.2% respectively, post-surgical factors 9.2%, HIV infection 13.6% and 5 cases of antithrombin III deficiency (1%). In 14.6% of cases, no risk factors were identified. Deep vein thrombosis was mostly localized to the left lower limb (65.7%) and proximal (70%), pulmonary embolisms were most often proximal (82.8%). VKA were the most prescribed therapeutic class at patient discharge (89%) follow-up direct oral anticoagulants (8.6%) with a gradual increase in the latter class to the time lines. The average duration of anticoagulant treatment was 11.06 ± 6.75 months.
Conclusion. Venous thromboembolic disease is frequently encountered and diagnosed. It is associated with risk factors that deserve to be taken into account for proper management. Treatment is based on the use of the vast majority of vitamins K antagonist in our context with a gradual increase in direct oral anticoagulants.
Keywords: Venous thromboembolic disease, epidemiology, diagnostic, anticoagulant, Abidjan Cardiology Institute
Les troubles de la conduction cardiaque dans le syndrome coronarien aigu avec sus-decalage de segment st : Etude de 53 cas
Objectifs : PrĂ©ciser la prĂ©valence, les facteurs de risque, les aspects Ă©lectrocardiographiques, thĂ©rapeutiques et Ă©volutifs des troubles de la conduction cardiaque chez les patients atteints dâun syndrome coronarien aigu avec sus-dĂ©calage du segment ST.Patients et mĂ©thode : Il sâagissait dâune Ă©tude rĂ©trospective descriptive portant sur une pĂ©riode de 8 ans (Octobre 2010 Ă Octobre 2018) et concernant 53 cas de troubles de la conduction cardiaque observĂ©s parmi 320 cas de syndrome coronariens avec susdĂ©calage du segment ST.RĂ©sultats : La prĂ©valence des troubles de la conduction cardiaque Ă©tait de 16,5%. La moyenne dâĂąge de nos patients concernĂ©s Ă©tait de 58 ans (extrĂȘmes : 26 et 81 ans). Lâhypertension artĂ©rielle Ă©tait le facteur de risque prĂ©dominant (60,4 %). La localisation infĂ©rieure Ă©tait la plus frĂ©quente (53%) et les troubles de cardiaques Ă©taient dominĂ©s par le bloc de branche droit (35,8%). La coronarographie a Ă©tĂ© rĂ©alisĂ©e chez tous nos patients ; les lĂ©sions retrouvĂ©es concernaient davantage lâartĂšre circonflexe (32,1%) et lâartĂšre inter ventriculaire antĂ©rieure (28,3%). Lâangioplastie a Ă©tĂ© rĂ©alisĂ©e dans 66% des cas et la thrombolyse dans 9,4%. Lâimplantation dâun pace maker provisoire a Ă©tĂ© faite dans 32% des cas LâĂ©volution Ă©tait favorable chez tous nos patients.Conclusion : Les troubles de la conduction cardiaque au cours du syndrome coronarien avec sus-dĂ©calage du segment ST doivent ĂȘtre diagnostiquĂ©s prĂ©cocement et prises en charge immĂ©diatement en raison du risque de mort subite.
Mots clés : Hypertension artérielle, Bloc de branche droit, Syndrome coronarien aigu avec sus-décalage de ST.
English Title: Cardiac conduction disorders in acute coronary syndrome with st elevation: Study of 53 cases
Introduction: Cardiac conduction disorders are quite common in the clinical evolution of acute coronary syndrome with ST segment elevation and have a significant influence on the patients prognosis.Objective: The determine the epidemiological clinical and therapeutic aspects of rhythm disorders with elevation in the ST segment.Methods: We have performed a descriptive retrospective study of 53 cases of rhythm disorder among 320 cases of coronaries syndromes with ST segment elevation.Results: The prevalence of cardiac conduction disorders was 16,5% over a period of 8 years. The average age of our patients was 58 years old (extremes: 26 to 81 years old). Hypertension was the most prevalent risk factor (60.4%). Low location was the most found (53%) and conduction disorders were dominated by right bundle branch block (35, 8%).Coronary angiography was performed in all our patients. The found lesions incoronary angiography concerned more the circumflex (32,1%) and anterior inter ventricular artery (28,3%). Coronary angioplasty has been performed in 66 % of cases, and thrombolysis in 9, 4%. The implantation of temporary pace maker was done in 32% of cases. The evolution was favorable for all our patients.Conclusion: Arrhythmias in ST-segment elevation coronary syndrome should be diagnosed early and immediately be taken care of because of the risk of sudden death.
Keywords: Arterial hypertension; Right bundle branch block, Acute coronary syndrome with ST elevation
Evaluation de lâexperience des aidants naturels des patients en insuffisance cardiaque
Introduction : Lâaidant naturel de lâinsuffisant cardiaque est sollicitĂ© au quotidien dans la prise en charge tant sur le plan financier, physique que psychologique. Cette sollicitation peut avoir des effets nĂ©gatifs sur la vie de la personne aidante. Lâobjectif de notre Ă©tude Ă©tait d'Ă©valuer lâexpĂ©rience de lâaidant naturel d'un patient atteint dâinsuffisance cardiaque.MĂ©thodologie et rĂ©sultats : Il sâagissait dâune Ă©tude transversale Ă visĂ©e descriptive et analytique ayant inclus 150 patients et 150 aidants naturels. LâexpĂ©rience des aidants naturels a Ă©tĂ© Ă©valuĂ©e avec lâĂ©chelle des 24 questions du « Caregiver reaction assessment » (CRA). Des coefficients de corrĂ©lation de Pearson ont Ă©tĂ© calculĂ©s par rĂ©gression linĂ©aire. Lâabsence dâassurance maladie avait un impact financier significatif sur les aidants (r=0,8 ; p=0,03). Le nombre dâhospitalisation pour insuffisance cardiaque influençait pĂ©jorativement lâestime de soi (r=-0,3 ; p=0,02) et avait un impact significatif sur la santĂ© de lâaidant (r=0,1 ; p=0,01). Le niveau dâinstruction apparaissait comme un facteur prĂ©dictif de lâimpact financier (r=-0,1; p=0,03).Conclusion : Lâinsuffisance cardiaque a un impact moral, physique et financier sur lâaidant naturel. La reconnaissance du rĂŽle de lâaidant naturel et son intĂ©gration aux sĂ©ances dâĂ©ducation thĂ©rapeutique pourrait allĂ©ger le fardeau liĂ© Ă la prise en charge des patients insuffisants cardiaques.
Mots-clés : Insuffisance cardiaque- aidant naturel- échelle du « caregiver reaction assessment
English Abstract:
Assessment of the experience of family caregivers for heart failure patients
Background : The family caregiver of heart failure patient is daily sollicited for financial, physical and psychological support. Unfortunately, this help can have negative effects on the caregiver's life. The aim of our study was to evaluate the experience of familycaregiver of heart failure patient.Methodology and results: This was a prospective study that included 150 patients and 150 caregivers. Caregiverâs experience was assessed using the Caregiver Reaction Assessment (CRA) 24-question scale. Pearson correlation coefficients were calculated using linear regression. Lack of health insurance had a significant financial impact on caregivers (r=0.8; p=0.03). The number of hospitalizations for heart failure had a negative impact on self-esteem (r=-0.3; p=0.02) and a significant impact on the caregiver's health (r=0.1; p=0.01). Education level appeared to be a predictor of financial impact (r=-0.1; p=0.03).Conclusion: Heart failure has a moral, physical and financial impact on the caregiver. Recognizing the role of the family caregivers and including them in therapeutic education meetings could reduce caregiving burden.
Keywords: Heart failure- family caregiver, caregiver reaction assessment, scal
Evaluation du risque de deces dans les syndromes coronariens aigus par le score de GRACE en CĂŽte dâIvoire
Rationnel : Le score de GRACE est un score recommandĂ© pour lâĂ©valuation pertinente du risque de dĂ©cĂšs pour une prise en charge efficiente des syndromes coronariens aigus (SCA).
Objectif : DĂ©terminer le risque de dĂ©cĂšs des SCA Ă Abidjan afin dâamĂ©liorer la prise en charge
MatĂ©riel et MĂ©thode : Nous avons menĂ© une Ă©tude observationnelle transversale sur une pĂ©riode de quatre ans du 01 Janvier 2010 au 31 DĂ©cembre 2013. Tous les patients consĂ©cutifs ĂągĂ©s dâau moins 18 ans, admis en unitĂ© de soins intensifs de lâInstitut de cardiologie dâAbidjan pour SCA ont Ă©tĂ© inclus. Les donnĂ©es Ă©pidĂ©miologiques, cliniques et thĂ©rapeutiques ont Ă©tĂ© analysĂ©es. Le risque de dĂ©cĂšs a Ă©tĂ© Ă©valuĂ© Ă partir du score de GRACE.
RĂ©sultats : 370 patients ont Ă©tĂ© inclus. L'Ăąge moyen des patients Ă©tait de 55,4 ans. On notait une prĂ©dominance masculine avec un sex-ratio de 3,87. Le dĂ©lai mĂ©dian dâadmission Ă©tait de 20 heures. Dans 20,8% des cas, les patients ont bĂ©nĂ©ficiĂ© dâune angioplastie coronaire. La thrombolyse a Ă©tĂ© rĂ©alisĂ©e chez 8,3% des patients admis pour SCA ST+. Le score de GRACE moyen Ă©tait de 96.36 ± 32.18. Il Ă©tait significativement plus Ă©levĂ© en cas de SCA ST+ (p<0.01). Le taux de dĂ©cĂšs Ă©tait de 10%. En analyse uni variable, le sexe fĂ©minin (p=0,005), lâinsuffisance cardiaque Ă lâadmission (p=0,01), la dysfonction ventriculaire gauche (p=0,04) et score de le score de GRACE (p<0,001) Ă©taient associĂ©s Ă la survenue de dĂ©cĂšs dans les SCA avec sus dĂ©calage persistant du segment ST. Dans les SCA sans sus dĂ©calage du segment ST, le diabĂšte (p=0,01) et la dysfonction ventriculaire gauche (p=0,02) Ă©taient les facteurs de risque de dĂ©cĂšs.
Conclusion : LâĂ©valuation du risque de dĂ©cĂšs par le score de GRACE pourrait sâintĂ©grer dans une Ă©valuation plus large des patients admis pour SCA, et contribuer Ă amĂ©liorer leur prise en charge.
English title: Mortality-risk assessment by grace score in acute coronary syndromes in CĂŽte dâIvoire
Abstract
Introduction: The GRACE score is a useful tool for mortality-risk assessment and management of patients hospitalized for an acute coronary syndrome (ACS).
Objective: To assess the risk of death of ACS patients in order to improve their management
Patients and methods: We carried out a cross-sectional observational study over a four-year period from January 01, 2010 to December 31, 2013. All consecutive patients aged 18 years or older, who presented to intensive care unit of Abidjan Heart Institute for ACS were included. Epidemiological, clinical and therapeutic data were analyzed. The risk of death was assessed by the GRACE score.
Results: 370 patients were included. The mean age was 55.4 years. There was a male predominance with a sex ratio of 3.87. The median delay between onset of symptoms and admission was 20.0 hours. In 11.1% of cases, patients underwent coronary angioplasty. Thrombolysis was performed in 8.3% of patients admitted for STEMI. The average GRACE score was 96.36 ± 32.18. It was significantly higher in STEMI (p <0.01). In NSTEMI, the risk of death was significantly higher in diabetics (p = 0.005) as well as in those with left ventricular failure (p = 0.002). In-hospital death rate was 10%. In univariate analysis, female sex (p=0.005), heart failure at admission (p=0.01), reduced ejectional fraction (p=0.04) and GRACE score (p<0.001) were associated factors for death in ST-elevation myocardial infarction patients. In non ST-elevation ACS, diabetes (p=0.01) and reduced ejectional fraction (p=0.02) were predictive factors for death.
Conclusion: As used in an integrated approach, GRACE score should be a useful tool in the management of ACS patients.
Key words: Acute Coronary Syndrome - GRACE score â CĂŽte dâIvoir
Effects of polymorphisms in alcohol metabolism and oxidative stress genes on survival from head and neck cancer
BACKGROUND: Heavy alcohol consumption increases risk of developing squamous cell carcinoma of the head and neck (SCCHN). Alcohol metabolism to cytotoxic and mutagenic intermediates acetaldehyde and reactive oxygen species is critical for alcohol-drinking-associated carcinogenesis. We hypothesized that polymorphisms in alcohol metabolism-related and antioxidant genes influence SCCHN survival. METHODS: Interview and genotyping data (64 polymorphisms in 12 genes) were obtained from 1227 white and African-American cases from the Carolina Head and Neck Cancer Epidemiology study, a population-based caseâcontrol study of SCCHN conducted in North Carolina from 2002 to 2006. Vital status, date and cause of death through 2009 were obtained from the National Death Index. KaplanâMeier log-rank tests and adjusted hazard ratios were calculated to identify alleles associated with survival. RESULTS: Most tested SNPs were not associated with survival, with the exception of the minor alleles of rs3813865 and rs8192772 in CYP2E1. These were associated with poorer cancer-specific survival (HR(rs3813865), 95%CI = 2.00, 1.33â3.01; HR(rs8192772), 95%CI = 1.62, 1.17â2.23). Hazard ratios for 8 additional SNPs in CYP2E1, GPx2, SOD1, and SOD2, though not statistically significant, were suggestive of differences in allele hazards for all-cause and/or cancer death. No consistent associations with survival were found for SNPs in ADH1B, ADH1C, ADH4, ADH7, ALDH2, GPx2, GPx4, and CAT. CONCLUSIONS: We identified some polymorphisms in alcohol and oxidative stress metabolism genes that influence survival in subjects with SCCHN. Previously unreported associations of SNPs in CYP2E1 warrant further investigation
The hypocretin/orexin system mediates the extinction of fear memories
Anxiety disorders are often associated with an inability to extinguish learned fear responses. The hypocretin/orexin system is involved in the regulation of emotional states and could also participate in the consolidation and extinction of aversive memories. Using hypocretin receptor-1 and hypocretin receptor-2 antagonists, hypocretin-1 and hypocretin-2 peptides, and hypocretin receptor-1 knockout mice, we investigated the role of the hypocretin system in cue- and context-dependent fear conditioning and extinction. Hypocretins were crucial for the consolidation of fear conditioning, and this effect was mainly observed in memories with a high emotional component. Notably, after the acquisition of fear memory, hypocretin receptor-1 blockade facilitated fear extinction, whereas hypocretin-1 administration impaired this extinction process. The extinction-facilitating effects of the hypocretin receptor-1 antagonist SB334867 were associated with increased expression of cFos in the basolateral amygdala and the infralimbic cortex. Intra-amygdala, but neither intra-infralimbic prefrontal cortex nor intra-dorsohippocampal infusion of SB334867 enhanced fear extinction. These results reveal a key role for hypocretins in the extinction of aversive memories and suggest that hypocretin receptor-1 blockade could represent a novel therapeutic target for the treatment of diseases associated with inappropriate retention of fear, such as post-traumatic stress disorder and phobias.This work was supported by the Instituto de Salud Carlos III grants, #PI13/00042 and #RD12/0028/0023 (RTA-RETICS), by the Spanish Ministry of Science #SAF2011-29864, the/nCatalan Government (SGR2009-00731), and by the Catalan Institution for Research and Advanced Studies (ICREA Academia program). Ăfrica Flores is a recipient of a predoctoral fellowship from the Spanish Ministry of Education
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