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Very Long Chain Lipids Favor the Formation of a Homogeneous Phase in Stratum Corneum Model Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13899-13907. [PMID: 33170015 DOI: 10.1021/acs.langmuir.0c02305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The stratum corneum (SC), the outermost layer of mammal epidermis, acts as a barrier dictating the rate of absorption of exogenous molecules through the skin, as well as to prevent excessive water loss from the body. The SC consists of protein-rich corneocytes embedded into a complex lipid mixture. The lipid fraction is mainly constituted of an equimolar mixture of ceramides (Cer), free fatty acids (FFA), and cholesterol (Chol), forming a solid phase in the intracellular space; this lipid phase is supposed to play a fundamental role in the SC barrier function. An unusual characteristic of this biological membrane is that its lipids generally bear very long acyl chains, with the 24-carbon long ones being the most abundant. In this work, we used Raman microspectroscopy and infrared spectroscopy to study the influence of the acyl chain length on the lipid mixing properties in SC model membranes. Our results revealed that the combination of ceramides and FFA bearing a very long chain is required for the formation of homogeneous lipid mixtures, while lipids with shorter chains (16-carbon and 20-carbon atom long) lead to domains with micrometer dimensions. It is proposed that the biological machinery necessary for acyl chain elongation occurring at the mammalian skin level is required to inhibit lipid phase separation, a critical feature in the proper barrier functioning.
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Abstract
Stratum corneum (SC), the outermost layer of the epidermis, is the primary barrier to percutaneous absorption. The diffusion of substances through the skin occurs through the SC lipid fraction, which is essentially constituted of an equimolar mixture of ceramides, free fatty acids, and cholesterol. The lipid constituents of SC are mainly forming continuous multilamellar membranes in the solid/crystalline state. However, recent findings suggest the presence of a highly disordered (liquid) phase formed by the unsaturated C18 chain of ceramide EOS, surrounded by a highly ordered lipid environment. The aim of the present work was to study the lipid spatial distribution of model SC membranes composed of ceramide EOS, ceramide NS, a mixture of free fatty acids, and cholesterol, using Raman microspectroscopy and AFM-IR spectroscopy techniques. The enhanced spatial resolution at the tens of nanometers scale of the AFM-IR technique revealed that the lipid matrix is overall homogeneous, with the presence of small, slightly enriched, and depleted regions in a lipid component. No liquid domains of ceramide EOS were observed at this scale, a result that is consistent with the model proposing that the oleate nanodrops are concentrated in the central layer of the three-layer organization of the SC membranes forming the long periodicity phase. In addition, both Raman microspectroscopy and AFM-IR techniques confirmed the fluid nature of the unsaturated chain of ceramide EOS while the rest of the lipid matrix was found highly ordered.
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Lipid composition modulates ATP hydrolysis and calcium phosphate mineral propagation by TNAP-harboring proteoliposomes. Arch Biochem Biophys 2020; 691:108482. [PMID: 32710882 DOI: 10.1016/j.abb.2020.108482] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/09/2020] [Accepted: 06/22/2020] [Indexed: 01/13/2023]
Abstract
Bone biomineralization is mediated by a special class of extracellular vesicles, named matrix vesicles (MVs), released by osteogenic cells. The MV membrane is enriched in sphingomyelin (SM), cholesterol (Chol) and tissue non-specific alkaline phosphatase (TNAP) compared with the parent cells' plasma membrane. TNAP is an ATP phosphohydrolase bound to cell and MV membranes via a glycosylphosphatidylinositol (GPI) anchor. Previous studies have shown that the lipid microenvironment influences the catalytic activity of enzymes incorporated into lipid bilayers. However, there is a lack of information about how the lipid microenvironment controls the ability of MV membrane-bound enzymes to induce mineral precipitation. Herein, we used TNAP-harboring proteoliposomes made of either pure dimyristoylphosphatidylcholine (DMPC) or DMPC mixed with either Chol, SM or both of them as MV biomimetic systems to evaluate how the composition modulates the lipid microenvironment and, in turn, TNAP incorporation into the lipid bilayer by means of calorimetry. These results were correlated with the proteoliposomes' catalytic activity and ability to induce the precipitation of amorphous calcium phosphate (ACP) in vitro. DMPC:SM proteoliposomes displayed the highest efficiency of mineral propagation, apparent affinity for ATP and substrate hydrolysis efficiency, which correlated with their highest degree of membrane organization (highest ΔH), among the tested proteoliposomes. Results obtained from turbidimetry and Fourier transformed infrared (FTIR) spectroscopy showed that the tested proteoliposomes induced ACP precipitation with the order DMPC:SM>DMPC:Chol:SM≈DMPC:Chol>DMPC which correlated with the lipid organization and the presence of SM in the proteoliposome membrane. Our study arises important insights regarding the physical properties and role of lipid organization in MV-mediated mineralization.
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Determination of n-alkane partitioning within phosphatidylethanolamine Lα/HII phases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183201. [DOI: 10.1016/j.bbamem.2020.183201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/11/2019] [Accepted: 01/16/2020] [Indexed: 02/06/2023]
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Interface-driven Sr-morin complexation at Langmuir monolayers for bioactive coating design. Colloids Surf B Biointerfaces 2019; 181:856-863. [PMID: 31382333 DOI: 10.1016/j.colsurfb.2019.06.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/07/2019] [Accepted: 06/17/2019] [Indexed: 11/19/2022]
Abstract
Flavonoid-metal complexes are widely studied because of their interesting luminescent behavior and biological activity. Despite the extensive exploration of flavonoid-metal coordination processes in solution, the formation of complexes using the flavonoid molecule inserted in a lipid membrane has been little investigated. This effect could provide important insight into the biological activity of flavonoids at lipid membranes and could represent an attractive strategy to design supramolecular structures. Here, we studied the complexation between Sr2+ and morin inserted in an octadecylphosphonic acid (OPA) Langmuir monolayer. This is a relevant system due to the synergism imposed by the association of the Sr2+ ability to control bone formation/resorption with the morin antioxidative effect. Morin incorporation into the OPA monolayers and further Sr2+ complexation were monitored by surface pressure isotherms. Electronic absorption spectroscopy and fluorescence techniques showed Sr-morin complexation both in solution and at the air-liquid interface. Although morin complexation has been described to occur only at basic pH, the specific thermodynamic properties at the air-liquid interface drove metal complexation. LB films were deposited on Ti surfaces, and the resulting OPA/Sr-morin coatings exhibited high surface free energy and increase on its polar component. This optimized surface feature supported further serum protein adsorption and osteoblast growth and differentiation, indicating that these lipid-based coatings are promising for bioactive coating design. This study paves the way for the use of this lipid-based coating in the design of implants for faster osteointegration. Moreover, flavonoid-metal complexation at membranes could also help to shed light on the biological role played by flavonoids.
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Efeitos de Diferentes Tratamentos de Superfície nas Características Superficiais e Resistência Adesiva da Zircônia Odontológica. JOURNAL OF HEALTH SCIENCES 2018. [DOI: 10.17921/2447-8938.2017v19n5p206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
O objetivo do estudo foi analisar características superficiais da zircônia, modificada superficialmente, por microscopia eletrônica de varredura (MEV), molhabilidade, energia de superfície, difração de raios x (DRX) e rugosidade superficial (Ra) e comparar a efetividade dos tratamentos na qualidade adesiva do material. Discos de zircônia foram distribuídos em sete grupos (n6): G1 (Rocatec), G2 (ácido hidrofluorídrico 40%, 210 segundos), G3 (ácido hidrofluorídrico 40%, 210 segundos + Rocatec), G4 (nanopartículas ZrO2), G5 (nanopartículas SiO2), G6 (nanopartículas SiO2 + ZrO2), G7 (nanopartículas SiO2 + ZrO2 + silano). Uma amostra por grupo (n1) foi analisada por DRX e MEV pós-tratamento e as demais, submetidas a microscopia confocal a laser (n5) para determinação da Ra. Sobre cada disco tratado foram cimentados 2 cilindros também de zircônia para teste de cisalhamento. Molhabilidade e energia de superfície foram desenvolvidas em triplicata (n3). G1, G3, G5 e G7 apresentaram valores de resistência ao cisalhamento superiores aos demais. (p<0,05). G5 e G7 apresentaram os maiores valores de Ra. Imagens em MEV mostraram modificações de superfície em todos os grupos. Em DRX, não houve alteração de fases da zircônia tratada. G1 e G3 apresentaram os menores ângulos de contato e G2, menor energia de superfície, sendo os demais estatisticamente semelhantes. Tratamentos que depositam sílica superficial são eficazes para união adesiva da zircônia. Nanopartículas de sílica parecem promissoras para o favorecimento da adesão em zircônia.Palavras-chave: Zircônio. Materiais Dentários. Nanopartículas.
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Influência de Dentifrícios Dessensibilizantes na Molhabilidade da Dentina Erodida. JOURNAL OF HEALTH SCIENCES 2018. [DOI: 10.17921/2447-8938.2017v19n5p97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
fragmentos de dentina bovina (7mm X 7mm) foram planificados, polidos e imersos em 10mL de ácido cítrico (pH 3,2) durante 2 horas e divididos aleatoriamente de acordo com o dentifrício (DD) utilizado: Colgate Total 12 (controle), Colgate Sensitive Pró- Alívio, Sensodyne Repair & Protect e Sensodyne Rápido Alívio e submetidos a escovação (TE) por 7 e 21 dias. Os espécimes foram submetidos a ciclos de escovação mecânica de 3 e 9 minutos, equivalente a 7 e 21 dias de escovação, respectivamente. Os espécimes foram condicionados com ácido fosfórico 37% por 15 segundos. Uma gota do sistema adesivo Single Bond Universal (3M) foi depositada sobre os espécimes e o ângulo de contato entre a superfície da dentina e o adesivo foi medido por meio de um Goniômetro. Doze espécimes (n 3) foram escovados nas mesmas condições experimentais por 21 dias e a topografia da dentina foi observada no Microscópio Confocal a Laser. Os dados foram submetidos à ANOVA 2 fatores (p>0,05). TE, isoladamente, foi estatisticamente significante (p<0,05) na molhabilidade da dentina erodida aos 21 dias (31,93±9,0). DD isoladamente e a interação DDxTE não apresentaram diferença estatística significante (p≤0,05). A microscopia indicou alterações topográficas em todos os grupos. Os dentifrícios dessensibilizantes não interferem na molhabilidade da dentina após 7 e 21 dias de escovação e todos os espécimes apresentaram túbulos dentinários abertos após o condicionamento ácido.Palavras-chave: Molhabilidade. Dentifrícios. Hipersensibilidade da Dentina.
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Evidence of hydrocarbon nanodrops in highly ordered stratum corneum model membranes. J Lipid Res 2017; 59:137-143. [PMID: 29092959 DOI: 10.1194/jlr.m080432] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/26/2017] [Indexed: 01/18/2023] Open
Abstract
The stratum corneum (SC), the top layer of skin, dictates the rate of both water loss through the skin and absorption of exogenous molecules into the body. The crystalline organization of the lipids in the SC is believed to be a key feature associated with the very limited permeability of the skin. In this work, we characterized the organization of SC lipid models that include, as in native SC, cholesterol, a series of FFAs (saturated with C16-C24 chains), as well as a ceramide bearing an oleate chain-linked to a very long saturated acyl chain [N-melissoyl-oleoyloxy hexacosanoyl-D-erythro-sphingosine (Cer EOS)]. The latter is reported to be essential for the native SC lipid organization. Our 2H-NMR, infrared, and Raman spectroscopy data reveal that Cer EOS leads to the formation of highly disordered liquid domains in a solid/crystalline matrix. The lipid organization imposes steric constraint on Cer EOS oleate chains in such a way that these hydrocarbon nanodroplets remain in the liquid state down to -30°C. These findings modify the structural description of the SC substantially and propose a novel role of Cer EOS, as this lipid is a strong modulator of SC solid/liquid balance.
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Manufacture of nanosized apatite coatings on titanium with different surface treatments using a supersaturated calcification solution. QUIM NOVA 2016. [DOI: 10.21577/0100-4042.20160161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Effect of Saturated Very Long-Chain Fatty Acids on the Organization of Lipid Membranes: A Study Combining 2H NMR Spectroscopy and Molecular Dynamics Simulations. J Phys Chem B 2016; 120:6951-60. [DOI: 10.1021/acs.jpcb.6b04958] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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The Chain Length of Free Fatty Acids Influences the Phase Behaviour of Stratum Corneum Model Membranes: A 2h-NMR and IR Investigation. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Poster session 2THE IMAGING EXAMINATIONP536Appropriate use criteria of transthoracic echocardiography and its clinical impact: a continuous challengeP537Implementation of proprietary plug-ins in the DICOM-based computerized echo reporting system fuels the use of 3D echo and deformation imaging in the clinical routine of a multivendor laboratoryP538Exercise stress echocardiography appropriate use criteria: real-life cases classification ease and agreement among cardiologistsANATOMY AND PHYSIOLOGY OF THE HEART AND GREAT VESSELSP539Functional capacity in older people with normal ejection fraction correlates with left ventricular functional reserve and carotid-femoral pulse wave velocity but not with E/e and augmentation indexP540Survey of competency of practitioners for diagnosis of acute cardiopulmonary diseases manifest on chest x-rayASSESSMENT OF DIAMETERS, VOLUMES AND MASSP541Left atrium remodeling in dialysis patients with normal ejection fractionP542The prediction of postinfarction left ventricular remodeling and the role of of leptin and MCP-1 in regard to the presence of metabolic syndromeP543Ascending aorta and common carotid artery: diameters and stiffness in a group of 584 healthy subjectsAssessments of haemodynamicsP544Alternate echo parameters in patients without estimable RVSPAssessment of systolic functionP545Reduced contractile performance in heart failure with preserved ejection fraction: determination using novel preload-adjusted maximal left ventricular ejection forceP546Left ventricular dimensions and prognosis in acute coronary syndromesP547Time course of myocardial alterations in a murine model of high fat diet: A strain rate imaging studyP548Subclinical left ventricular systolic dysfunction in patients with premature ventricular contractionsP549Global myocardial strain by CMR-based feature tracking (FT) and tagging to predict development of severe left ventricular systolic dysfunction after acute st-elevation myocardial infarctionP550Echocardiographic analysis of left and right ventricular function in patients after mitral valve reconstructionP551The role of regional longitudinal strain assessment in predicting response to cardiac resynchronization therapy in patients with left ventricular systolic dysfunction and left bundle branch blockP552Speckle tracking automatic border detection improves echocardiographic evaluation of right ventricular systolic function in repaired tetralogy of fallot patients: comparison with MRI findingsP553Echocardiography: a reproducible and relevant tool in pah? intermediate results of the multicentric efort echogardiographic substudy (evaluation of prognostic factors and therapeutic targets in pah)Assessment of diastolic functionP554Relationship between left ventricular filling pressures and myocardial fibrosis in patients with uncomplicated arterial hypertensionP555Cardiac rehabilitation improves echocardiographic parameters of diastolic function in patients with ischemic heart diseaseP556Diastolic parameters in the calcified mitral annulusP557Biomarkers and echocardiography - combined weapon to diagnose and prognose heart failure with and without preserved ejection fractionP558Diastolic function changes of the maternal heart in twin and singleton pregnancyIschemic heart diseaseP559Syntax score as predictor for the correlation between epicardial adipose tissue and the severity of coronary lesions in patients with significant coronary diseaseP560Impact of strain analysis in ergonovine stress echocardiography for diagnosis vasospastic anginaP561Cardiac magnetic resonance tissue tracking: a novel method to predict infarct transmurality in acute myocardial infarctionP562Infarct size is correlated to global longitudinal strain but not left ventricular ejection fraction in the early stage of acute myocardial infarctionP563Magnetic resonance myocardial deformation assessment with tissue tracking and risk stratification in acute myocardial infarction patientsP564Increase in regional end-diastolic wall thickness by transthoracic echocardiography as a biomarker of successful reperfusion in anterior ST elevation acute myocardial infarctionP565Mitral regurgitation is associated with worse long-term prognosis in ST-segment elevation myocardial infarction treated with primary percutaneous coronary interventionP566Statistical significance of 3D motion and deformation indexes for the analysis of LAD infarctionHeart valve DiseasesP567Paradoxical low gradient aortic stenosis: echocardiographic progression from moderate to severe diseaseP568The beneficial effects of TAVI in mitral insufficiencyP569Impact of thoracic aortic calcification on the left ventricular hypertrophy and its regression after aortic valve replacement in patients with severe aortic stenosisP570Additional value of exercise-stress echocardiography in asymptomatic patients with aortic valve stenosisP571Valvulo-arterial impedance in severe aortic stenosis: a dual imaging modalities studyP572Left ventricular mechanics: novel tools to evaluate left ventricular performance in patients with aortic stenosisP573Comparison of long-term outcome after percutaneous mitral valvuloplasty versus mitral valve replacement in moderate to severe mitral stenosis with left ventricular dysfunctionP574Incidence of de novo left ventricular dysfunction in patient treated with aortic valve replacement for severe aortic regurgitationP575Transforming growth factor-beta dependant progression of the mitral valve prolapseP576Quantification of mitral regurgitation with multiple jets: in vitro validation of three-dimensional PISA techniqueP577Impaired pre-systolic contraction and saddle-shape deepening of mitral annulus contributes to atrial functional regurgitation: a three-dimensional echocardiographic studyP578Incidence and determinants of left ventricular (lv) reverse remodeling after MitraClip implantation in patients with moderate-to severe or severe mitral regurgitation and reduced lv ejection fractionP579Severe functional tricuspid regurgitation in rheumatic heart valve disease. New insights from 3D transthoracic echocardiographyP58015 years of evolution of the etiologic profile for prosthetic heart valve replacement through an echocardiography laboratoryP581The role of echocardiography in the differential diagnosis of prolonged fever of unknown originP582Predictive value for paravalvular regurgitation of 3-dimensional anatomic aortic annulus shape assessed by multidetector computed tomography post-transcatheter aortic valve replacementP583The significance and advantages of echo and CT imaging & measurement at transcatherter aortic valve implantation through the left common carotid accessP584Comparison of the self-expandable Medtronic CoreValve versus the balloon-expandable Edwards SAPIEN bioprostheses in high-risk patients undergoing transfemoral aortic valve implantationP585The impact of transcatheter aortic valve implantation on mitral regurgitation severityP586Echocardiographic follow up of children with valvular lesions secondary to rheumatic heart disease: Data from a prospective registryP587Valvular heart disease and different circadian blood pressure profilesCardiomyopathiesP588Comparison of transthoracic echocardiography versus cardiac magnetic for implantable cardioverter defibrillator therapy in primary prevention strategy dilated cardiomyopathy patientsP589Incidence and prognostic significance of left ventricle reverse remodeling in a cohort of patients with idiopathic dilated cardiomyopathyP590Early evaluation of diastolic function in fabry diseaseP591Echocardiographic predictors of atrial fibrillation development in hypertrophic cardiomyopathyP592Altered Torsion mechanics in patients with hypertrophic cardiomyopathy: LVOT-obstruction is the topdog?P593Prevention of sudden cardiac death in hypertrophic cardiomyopathy: what has changed in the guidelines?P594Coronary microcirculatory function as determinator of longitudinal systolic left ventricular function in hypertrophic cardiomyopathyP595Detection of subclinical myocardial dysfunction by tissue Doppler ehocardiography in patients with muscular dystrophiesP596Speckle tracking myocardial deformation analysis and three dimensional echocardiography for early detection of chemotherapy induced cardiac dysfunction in bone marrow transplantation patientsP597Left ventricular non compaction or hypertrabeculation: distinguishing between physiology and pathology in top-level athletesP598Role of multi modality imaging in familiar screening of Danon diseaseP599Early impairment of global longitudinal left ventricular systolic function independently predicts incident atrial fibrillation in type 2 diabetes mellitusP600Fetal cardiovascular programming in maternal diabetes mellitus and obesity: insights from deformation imagingP601Longitudinal strain stress echo evaluation of aged marginal donor hearts: feasibility in the Adonhers project.P602Echocardiographic evaluation of left ventricular size and function following heart transplantation - Gender mattersSystemic diseases and other conditionsP603The impact of septal kinetics on adverse ventricular-ventricular interactions in pulmonary stenosis and pulmonary arterial hypertensionP604Improvement in right ventricular mechanics after inhalation of iloprost in pulmonary hypertensionP605Does the treatment of patients with metabolic syndrome correct the right ventricular diastolic dysfunction?P606Predictors of altered cardiac function in breast cancer survivors who were treated with anthracycline-based therapyP607Prevalence and factors related to left ventricular systolic dysfunction in asymptomatic patients with rheumatoid arthritis: a prospective tissue-doppler echocardiography studyP608Diastolic and systolic left ventricle dysfunction presenting different prognostic implications in cardiac amyloidosisP609Diagnostic accuracy of Bedside Lung Ultrasonography in Emergency (BLUE) protocol for the diagnosis of pulmonary embolismP610Right ventricular systolic dysfunction and its incidence in breast cancer patients submitted to anthracycline therapyP611Right ventricular dysfunction is an independent predictor of survival among cirrhotic patients undergoing liver transplantCongenital heart diseaseP612Hypoplasia or absence of posterior leaflet: a rare congenital anomaly of the mitral valveP613ECHO screening for Barlow disease in proband's relativesDiseases of the aortaP614Aortic size distribution and prognosis in an unselected population of patients referred for standard transthoracic echocardiographyP615Abdominal aorta aneurysm ultrasonographic screening in a large cohort of asympromatic volounteers in an Italian urban settingP616Thoracic aortic aneurysm and left ventricular systolic functionStress echocardiographyP617Wall motion score index, systolic mitral annulus velocity and left ventricular mass predicted global longitudinal systolic strain in 238 patients examined by stress echocardiographyP618Prognostic parameters of exercise-induced severe mitral valve regurgitation and exercise-induced systolic pulmonary hypertensionP619Risk stratification after myocardial infarction: prognostic value of dobutamine stress echocardiographyP620relationship between LV and RV myocardial contractile reserve and metabolic parameters during incremental exercise and recovery in healthy children using 2-D strain analysisP621Increased peripheral extraction as a mechanism compensatory to reduced cardiac output in high risk heart failure patients with group 2 pulmonary hypertension and exercise oscillatory ventilationP622Can exercise induced changes in cardiac synchrony predict response to CRT?Transesophageal echocardiographyP623Fully-automated software for mitral valve assessment in chronic mitral regurgitation by three-dimensional transesophageal echocardiographyP624Real-time 3D transesophageal echocardiography provides more accurate orifice measurement in percutaneous transcatheter left atrial appendage closureP625Percutaneous closure of left atrial appendage: experience of 36 casesReal-time three-dimensional TEEP626Real-time three-dimensional transesophageal echocardiography during pulmonary vein cryoballoon ablation for atrial fibrilationP627Three dimensional ultrasound anatomy of intact mitral valve and in the case of type 2 disfunctionTissue Doppler and speckle trackingP629Left ventricle wall motion tracking from echocardiographic images by a non-rigid image registrationP630The first experience with the new prototype of a robotic system for remote echocardiographyP631Non-invasive PCWP influence on a loop diuretics regimen monitoring model in ADHF patients.P632Normal range of left ventricular strain, dimensions and ejection fraction using three-dimensional speckle-tracking echocardiography in neonatesP633Circumferential ascending aortic strain: new parameter in the assessment of arterial stiffness in systemic hypertensionP634Aortic vascular properties in pediatric osteogenesis imperfecta: a two-dimensional echocardiography derived aortic strain studyP635Assessment of cardiac functions in children with sickle cell anemia: doppler tissue imaging studyP636Assessment of left ventricular function in type 1 diabetes mellitus patients by two-dimensional speckle tracking echocardiography: relation to duration and control of diabetesP637A study of left ventricular torsion in l-loop ventricles using speckle-tracking echocardiographyP638Despite No-Reflow, global and regional longitudinal strains assessed by two-dimensional speckle tracking echocardiography are predictive indexes of left ventricular remodeling in patients with STEMIP639The function of reservoir of the left atrium in patients with medicaly treated arterial hypertensionP640The usefulness of speckle tracking analysis for predicting the recovery of regional systolic function after myocardial infarctionP641Two dimensional speckle tracking echocardiography in assessment of left ventricular systolic function in patients with rheumatic severe mitral regurgitation and normal ejection fractionP642The prediction of left-main and tripple vessel coronary artery disease by tissue doppler based longitudinal strain and strain rate imagingP643Role of speckle tracking in predicting arrhythmic risk and occurrence of appropriate implantable defibrillator Intervention in patients with ischemic and non-ischemic cardiomyopathyComputed Tomography & Nuclear CardiologyP644Cardiac adrenergic activity in patients with nonischemic dilated cardiomyopathy. Correlation with echocardiographyP645Different vascular territories and myocardial ischemia, there is a gradient of association? Eur Heart J Cardiovasc Imaging 2015. [DOI: 10.1093/ehjci/jev278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Chain Length of Free Fatty Acids Influences the Phase Behavior of Stratum Corneum Model Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11621-11629. [PMID: 26442576 DOI: 10.1021/acs.langmuir.5b03271] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The skin, the largest organ of the human body, forms a flexible interface between our internal and external environment that protects our organism from exogenous compounds as well as excessive water loss. The stratum corneum (SC), the outermost layer of mammal epidermis, is mainly responsible for the skin impermeability. The SC is formed by corneocytes embedded in a lipid matrix, which is mostly constituted of ceramides (Cer), free fatty acids (FFA), and cholesterol (Chol), organized in two coexisting crystalline lamellar phases. This arrangement of lipids is crucial to skin barrier function. The aim of this paper is to determine the impact of FFA chain length on the phase behavior of SC model lipid membranes using solid-state deuterium NMR and IR spectroscopy. We studied ternary mixtures of N-lignoceroyl-d-erythro-sphingosine (Cer24), cholesterol, and palmitic (FFA16) or lignoceric (FFA24) acid in an equimolar ratio. This proportion replicates the lipid composition found in the SC lipid matrix. Our studies revealed that the phase behavior of Cer24/FFA/Chol ternary mixtures is strongly affected by the length of the FFA. We found the formation of phase-separated crystalline lipid domains when using palmitic acid whereas the use of lignoceric acid results in a more homogeneous mixture. In addition, it was observed that mixtures with lignoceric acid form a gel phase, a very unusual feature for SC model mixtures.
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Abstract
Obstruction of the portal vein may be related to constriction by malignant tumors or thrombosis associated with liver disease. We herein have reported our experience with patients undergoing liver transplantation with portal vein thrombosis (PVT) whose diagnosis was made intraoperatively. From September 1991 to May 2009, we studied 27/419 (6.4%) patients with PVT who were evaluated according to the presence of esophagogastric varices, underlying disease, malignancy, and if there was previous surgery, review of medical records on data collected prospectively. We observed 24 (88.9%) patients with PVT grade 1, 2 (7.4%) with grade 2, and 1 (3.7%) with grade 3. The average age of the PVT patients was 47.5 years; the average model for End-Stage Liver Discase score was 18.3, and the predominant diagnosis, hepatitis C cirrhosis. Eighteen underwent a sclerotherapy/ligature. The sensitivity of ultrasound for grade 1 thrombosis was 39.1%; for grade 2, 50%; and for grade 3, 100%. Portal vein thrombectomy was performed in 24 patients. In other patients (grade 2), we performed an anastomosis of the donor portal vein to the recipient gastric vein or to a greater splanchnic collateral vein. In only 1 patient was the graft performed using the donor portal vein-donor iliac vein-recipient superior mesenteric vein. None of the patients displayed PVT in the immediate postoperative period. Actuarial survivals at the years 1, 3, and 5 were 85%, 74%, and 63%, respectively. We concluded that PVT cannot be considered to be a contraindication for liver transplantation.
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[Historical review about the research on toxoplasmosis]. REVISTA CUBANA DE MEDICINA TROPICAL 2001; 53:111-7. [PMID: 15844299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Toxoplasmposis is one of the zoonotic diseases which is widely spread all over the world. It is caused by Toxoplasma gondii. In this paper we made a chronological synthesis of some of the numerous investigations that have been made in the world and in Cuba.
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Concentration of airborne pollen from Cupressaceae in Lisbon. ALLERGIE ET IMMUNOLOGIE 2000; 32:109-10. [PMID: 10815239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The concentration of airborne pollen from Cupressaceae was regularly monitored++ in Lisbon during 1997 and 1999, and the phenology of flowering cypress was studied in several species of the genus from 1992 to February 2000. Both methods showed a peak of pollen abundance during the month of February, with the airborne pollen concentration decreasing strongly to March and April. The results obtained are in accordance with the literature for the Mediterranean area, but in Lisbon the peak started and finished earlier than in other Mediterranean towns already studied.
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Abstract
Rotaviruses are known as major causal agents of diarrhea in humans and animals. They affect young animals in intensive rearing and cause great economic losses. This study evaluated the infectivity of porcine rotavirus maintained for 32 months at approximately 10 degrees C in the original stool specimens. Thirty stool specimens of 1-4-week-old piglets from breeding farms located in the southwest of the State of Parana were selected for this study. They were randomly chosen from stool samples positive for rotavirus RNA by polyacrylamide gel electrophoresis (PAGE) at the time of collection. The thirty stool samples maintained for 32 months were re-tested by PAGE and 11 out of 30 were still positive showing physical integrity of the eleven segments of viral RNA. In order to demonstrate the maintenance of viral infectivity processed fecal homogenates were inoculated in MA-104 cell cultures. After an average of three blind passages 5 out of 11 samples demonstrated cytopathic effect similar to that of a simian rotavirus (SA-11) used as positive control. To confirm these findings an immunofluorescence test was performed and typical cytoplasmatic granular fluorescence was observed. Electron microscopy of stool samples showed that most of the virus particles were single-shelled and some were found to be in advanced state of degradation. The viral nucleic acid extracted from six fecal specimens out of those that showed physical integrity of rotavirus RNA by PAGE were also amplified when submitted to RT-PCR demonstrating stability of viral RNA. We therefore concluded that porcine rotavirus infectivity is maintained for a long period of time in stool specimens at low temperature.
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