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1.
Sci Rep ; 14(1): 8206, 2024 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589451

RESUMEN

The primary objective of this study was to evaluate the prevalence of low femoral and lumbar spine bone mineral density (BMD) in adults with arthrogryposis multiplex congenita (AMC). We performed a retrospective cohort analysis of adults with AMC who were enrolled in the French Reference Center for AMC and in the Pediatric and Adult Registry for Arthrogryposis (PARART, NCT05673265). Patients who had undergone dual-energy X-ray absorptiometry (DXA) and/or vitamin D testing were included in the analysis. Fifty-one patients (mean age, 32.9 ± 12.6 years) were included; 46 had undergone DXA. Thirty-two (32/51, 62.7%) patients had Amyoplasia, and 19 (19/51, 37.3%) had other types of AMC (18 distal arthrogryposis, 1 Larsen). Six patients (6/42, 14.3%) had a lumbar BMD Z score less than - 2. The mean lumbar spine Z score (- 0.03 ± 1.6) was not significantly lower than the expected BMD Z score in the general population. Nine (9/40, 22.5%) and 10 (10/40, 25.0%) patients had femoral neck and total hip BMD Z scores less than - 2, respectively. The mean femoral neck (- 1.1 ± 1.1) and total hip (- 1.2 ± 1.2) BMD Z scores in patients with AMC were significantly lower than expected in the general population (p < 0.001). Femoral neck BMD correlated with height (rs = 0.39, p = 0.01), age (rs = - 0.315, p = 0.48); total hip BMD correlated with height (rs = 0.331, p = 0.04) and calcium levels (rs = 0.41, p = 0.04). Twenty-five patients (25/51, 49.0%) reported 39 fractures. Thirty-one (31/36, 86.1%) patients had 25-hydroxyvitamin D levels less than 75 nmol/l, and 6 (6/36, 16.7%) had 25-hydroxyvitamin D levels less than 75 nmol/l. Adults with AMC had lower hip BMD than expected for their age, and they more frequently showed vitamin D insufficiency. Screening for low BMD by DXA and adding vitamin D supplementation when vitamin D status is insufficient should be considered in adults with AMC, especially if there is a history of falls or fractures.


Asunto(s)
Anomalías Múltiples , Artrogriposis , Adulto , Humanos , Persona de Mediana Edad , Adulto Joven , Absorciometría de Fotón , Densidad Ósea , Estudios Retrospectivos , Vitamina D
2.
Clin Immunol ; 259: 109876, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38145857

RESUMEN

Autoimmune tissues may contain ectopic germinal centers (EGCs). However, these structures have never been described in the liver of patients suffering from autoimmune hepatitis (AIH). We retrospectively reviewed histological features of 120 definite AIH cases, and found 10 cases harboring markers of EGCs. In these cases, CD21+ follicular dendritic cells were intermixed with CD3+ T and CD20+ B lymphocytes. The latter expressed the GC-specific marker bcl6, and some were proliferative as assessed by Ki67 expression. Antibody-secreting cells (ASCs) defined by expression of the mum-1 transcription factor and presence of cytoplasmic IgMs were usually present in the periphery of these structures, but some were also present within the EGCs. Notably, some ASCs were IgG-switched. Common treatment applied to AIH patients achieved biochemical normalization as efficiently as in patients without EGCs. In the present study, we provide the proof for the occurrence of functional EGCs enabling differentiation of B cells into ASCs and occurrence of immunoglobulin switch in AIH livers.


Asunto(s)
Hepatitis Autoinmune , Humanos , Estudios Retrospectivos , Centro Germinal , Linfocitos B/metabolismo
3.
Scand J Rheumatol ; 47(6): 440-446, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29774784

RESUMEN

OBJECTIVE: We conducted this study to determine whether alcohol consumption influences radiological progression in early rheumatoid arthritis (RA). METHOD: Patients fulfilling the European League Against Rheumatism/American College of Rheumatology 2010 criteria in the early arthritis cohort ESPOIR (Étude et Suivi des Polyarthrites Indifférenciées Récentes) were included in this study. Alcohol consumption was collected at baseline and at each visit. We classified alcohol consumption into three groups: abstinent (0 g/day), moderate (≤ 20 g/day for women, ≤ 30 g/day for men), and abuse (> 20 g/day for women, > 30 g/day for men). The primary outcome was the occurrence of radiological progression, defined as an increase ≥ 5 points in the total Sharp/van der Heijde score. We investigated whether alcohol consumption is predictive of radiological progression at 1, 3, and 5 years by univariate and multivariate analysis adjusted for age, baseline erosion, rheumatoid factor, anti-citrullinated peptide antibody, smoking status, body mass index, and treatment with leflunomide or methotrexate and biologics. RESULTS: The study included 596 patients. When considering the influence of gender on the interaction between alcohol consumption and radiological progression, we showed a deleterious effect of moderate consumption in women [odds ratio (OR) = 1.73, 95% confidence interval (CI) 1.01; 2.96, p = 0.045] and a trend towards a protective effect of moderate consumption in men (OR = 0.50, 95% CI 0.21; 1.16, p = 0.106) in multivariate analysis. CONCLUSION: Our data suggest a deleterious effect of moderate consumption of alcohol on radiological progression in women, but not in men, with early RA.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Artritis Reumatoide/diagnóstico por imagen , Adulto , Artritis Reumatoide/patología , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Pie/diagnóstico por imagen , Pie/patología , Francia , Humanos , Masculino , Persona de Mediana Edad , Radiografía/métodos , Factores Sexuales , Articulación de la Muñeca/diagnóstico por imagen , Articulación de la Muñeca/patología
4.
Cell Death Dis ; 5: e1405, 2014 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-25188515

RESUMEN

The retinoblastoma gene, rb, ensures at least its tumor suppressor function by inhibiting cell proliferation. Its role in apoptosis is more complex and less described than its role in cell cycle regulation. Rbf1, the Drosophila homolog of Rb, has been found to be pro-apoptotic in proliferative tissue. However, the way it induces apoptosis at the molecular level is still unknown. To decipher this mechanism, we induced rbf1 expression in wing proliferative tissue. We found that Rbf1-induced apoptosis depends on dE2F2/dDP heterodimer, whereas dE2F1 transcriptional activity is not required. Furthermore, we highlight that Rbf1 and dE2F2 downregulate two major anti-apoptotic genes in Drosophila: buffy, an anti-apoptotic member of Bcl-2 family and diap1, a gene encoding a caspase inhibitor. On the one hand, Rbf1/dE2F2 repress buffy at the transcriptional level, which contributes to cell death. On the other hand, Rbf1 and dE2F2 upregulate how expression. How is a RNA binding protein involved in diap1 mRNA degradation. By this way, Rbf1 downregulates diap1 at a post-transcriptional level. Moreover, we show that the dREAM complex has a part in these transcriptional regulations. Taken together, these data show that Rbf1, in cooperation with dE2F2 and some members of the dREAM complex, can downregulate the anti-apoptotic genes buffy and diap1, and thus promote cell death in a proliferative tissue.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Factor de Transcripción E2F2/metabolismo , Proteínas Inhibidoras de la Apoptosis/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Factores de Transcripción/metabolismo , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Animales , Apoptosis , Proteínas Portadoras/antagonistas & inhibidores , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Caspasas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Regulación hacia Abajo , Drosophila/crecimiento & desarrollo , Proteínas de Drosophila/antagonistas & inhibidores , Proteínas de Drosophila/genética , Factor de Transcripción E2F2/genética , Proteínas Inhibidoras de la Apoptosis/genética , Fenotipo , Unión Proteica , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-myb/metabolismo , Interferencia de ARN , ARN Mensajero/metabolismo , Proteína de Retinoblastoma , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Alas de Animales/crecimiento & desarrollo , Alas de Animales/metabolismo
5.
Ann Phys Rehabil Med ; 56(9-10): 621-33, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24459695

RESUMEN

OBJECTIVE: To evaluate the reliability and functional acceptability of the ''Synthetic Autonomous Majordomo'' (SAM) robotic aid system (a mobile Neobotix base equipped with a semi-automatic vision interface and a Manus robotic arm). MATERIALS AND METHODS: An open, multicentre, controlled study. We included 29 tetraplegic patients (23 patients with spinal cord injuries, 3 with locked-in syndrome and 4 with other disorders; mean SD age: 37.83 13.3) and 34 control participants (mean SD age: 32.44 11.2). The reliability of the user interface was evaluated in three multi-step scenarios: selection of the room in which the object to be retrieved was located (in the presence or absence of visual control by the user), selection of the object to be retrieved, the grasping of the object itself and the robot's return to the user with the object. A questionnaire was used to assess the robot's user acceptability. RESULTS: The SAM system was stable and reliable: both patients and control participants experienced few failures when completing the various stages of the scenarios. The graphic interface was effective for selecting and grasping the object ­ even in the absence of visual control. Users and carers were generally satisfied with SAM, although only a quarter of patients said that they would consider using the robot in their activities of daily living.


Asunto(s)
Aceptación de la Atención de Salud , Robótica , Dispositivos de Autoayuda , Análisis y Desempeño de Tareas , Actividades Cotidianas , Adulto , Brazo , Vivienda , Humanos , Microcomputadores , Persona de Mediana Edad , Cuadriplejía/rehabilitación , Adulto Joven
6.
Ann Chir Plast Esthet ; 57(3): 250-3, 2012 Jun.
Artículo en Francés | MEDLINE | ID: mdl-21715075

RESUMEN

The management of patients with a cleft lip in developing countries is often the prerogative of humanitarian missions from developed countries. The goal of our work is to conduct a first epidemiological, clinical and therapeutic assessment of the management of cleft lips by a local team and to evidence the difficulties faced by us in our working conditions. In a retrospective study covering a period of about five years (January 2004 to March 2009), 205 cases of nasolabial clefts are assembled. The mean age at the time of the first visit is 17 months. A slight female predominance is observed. The majority of patients are from the capital city. A close relative with a cleft is found in 6.8% of them. In 44.9% of cases, it is a simple cleft lip. A cleft palate is associated in 47.8% of cases. Associated malformations are observed in 10.5% of cases. We operated on 110 patients. The mean age at the first surgery is two years. Millard's technique is our technique of choice. No operative mortality is observed. In 17.4% of cases, operative morbidity occurred in the form of suppuration with partial or complete early suture release. The esthetic result is satisfactory in 67.7% of cases. This management could be improved by creating a multidisciplinary team including--in addition to surgeons--dentists, speech-language pathologists, psychologists, etc.


Asunto(s)
Labio Leporino/cirugía , Fisura del Paladar/cirugía , Conducta Cooperativa , Países en Desarrollo , Accesibilidad a los Servicios de Salud , Comunicación Interdisciplinaria , Grupo de Atención al Paciente , Adolescente , Niño , Preescolar , Labio Leporino/epidemiología , Labio Leporino/etiología , Fisura del Paladar/epidemiología , Estudios Transversales , Femenino , Necesidades y Demandas de Servicios de Salud , Humanos , Lactante , Recién Nacido , Masculino , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Reoperación , Estudios Retrospectivos , Senegal , Dehiscencia de la Herida Operatoria/epidemiología , Dehiscencia de la Herida Operatoria/etiología , Dehiscencia de la Herida Operatoria/cirugía
7.
Rev Med Interne ; 31(6): 458-61, 2010 Jun.
Artículo en Francés | MEDLINE | ID: mdl-20398973

RESUMEN

Although S100 proteins represent 40% of the neutrophil cytoplasmic proteins, their physiological and pathological functions are still unclear. S100A8, S100A9 and S100A12 protein concentrations are dramatically enhanced in synovial fluid and synovium of patients suffering from rheumatoid arthritis. Their expression seems to correlate with disease activity and joint damage. These proteins are likely involved in rheumatoid arthritis pathogenesis by enhancing extracellular matrix proteolysis, autoimmunity and inducing the pseudotumoral phenotype of the synoviocytes in rheumatoid arthritis. S100A8, S100A9 and S100A12 assessment will probably constitute a relevant tool for rheumatoid arthritis diagnosis and will improve inflammatory arthritides management.


Asunto(s)
Artritis Reumatoide/diagnóstico , Artritis Reumatoide/inmunología , Calgranulina A/sangre , Calgranulina B/sangre , Proteínas S100/sangre , Artritis Reumatoide/sangre , Biomarcadores/sangre , Progresión de la Enfermedad , Humanos , Inflamación/inmunología , Valor Predictivo de las Pruebas , Proteína S100A12 , Sensibilidad y Especificidad , Líquido Sinovial/inmunología , Membrana Sinovial/inmunología
8.
Exp Cell Res ; 315(20): 3509-20, 2009 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-19632222

RESUMEN

To better understand the relationship between the subcellular compartmentalization of endothelial nitric oxide synthase (eNOS) and its function in endothelial cells, we addressed the roles of the microtubule network and of its dynamics in organizing Golgi-bound eNOS. We found that part of Golgi-bound eNOS localizes to the trans-Golgi network and/or to trans-Golgi network-derived vesicles and membrane tubules that are organized preferentially by stable microtubules. Also, while most of cellular eNOS was recovered in a detergent-resistant microtubule-enriched subcellular fraction, its recovery was impaired after total microtubule disassembly, but not after selective disassembly of dynamic microtubules or after microtubule stabilization. Basal eNOS phosphorylation on Ser(1177) further required the association of the trans-Golgi network to stable microtubules and was enhanced by microtubule stabilization. We finally show that the involvement of stable microtubules in basal eNOS phosphorylation involved alpha-tubulin acetylation. Microtubule-dependent organization of subcellular eNOS and control over its phosphorylation would thus be essential for endothelial cells to maintain their basal eNOS function.


Asunto(s)
Células Endoteliales/metabolismo , Microtúbulos/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosfoserina/metabolismo , Tubulina (Proteína)/metabolismo , Acetilación/efectos de los fármacos , Membrana Celular/metabolismo , Células Cultivadas , Citosol/metabolismo , Detergentes/química , Células Endoteliales/efectos de los fármacos , Aparato de Golgi/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Ácidos Hidroxámicos/farmacología , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Microdominios de Membrana/metabolismo , Microtúbulos/efectos de los fármacos , Nocodazol/farmacología , Paclitaxel/farmacología , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Unión Proteica/efectos de los fármacos , Unión Proteica/fisiología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Transfección , Tubulina (Proteína)/genética , Venas Umbilicales/citología , Red trans-Golgi/metabolismo
9.
Ann Rheum Dis ; 68(8): 1328-33, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18664547

RESUMEN

OBJECTIVES: The use of biologicals such as infliximab has dramatically improved the treatment of rheumatoid arthritis (RA). However, factors predictive of therapeutic response need to be identified. A proteomic study was performed prior to infliximab therapy to identify a panel of candidate protein biomarkers of RA predictive of treatment response. METHODS: Plasma profiles of 60 patients with RA (28 non-responders (as defined by the American College of Rheumatology 20% improvement criteria (ACR20)) negative and 32 responders (ACR70 positive) to infliximab) were studied by surface enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS) technology on two types of arrays, an anion exchange array (SAX2) and a nickel affinity array (IMAC3-Ni). Biomarker characterisation was carried out using classical biochemical methods (purification by ammonium sulfate precipitation or metal affinity chromatography) and identification by matrix assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS analysis. RESULTS: Two distinct protein profiles were observed on both arrays and several proteins were differentially expressed in both patient populations. Five proteins at 3.86, 7.77, 7.97, 8.14 and 74.07 kDa were overexpressed in the non-responder group, whereas one at 28 kDa was increased in the responder population (sensitivity>56%, specificity>77.5%). Moreover, combination of several biomarkers improved the sensitivity and specificity of the detection of patient response to over 97%. The 28 kDa protein was characterised as apolipoprotein A-I and the 7.77 kDa biomarker was identified as platelet factor 4. CONCLUSIONS: Six plasma biomarkers are characterised, enabling the detection of patient response to infliximab with high sensitivity and specificity. Apolipoprotein A-1 was predictive of a good response to infliximab, whereas platelet factor 4 was associated with non-responders.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Apolipoproteína A-I/sangre , Artritis Reumatoide/tratamiento farmacológico , Factor Plaquetario 4/sangre , Adulto , Anciano , Artritis Reumatoide/sangre , Biomarcadores/sangre , Monitoreo de Drogas/métodos , Femenino , Humanos , Infliximab , Masculino , Persona de Mediana Edad , Pronóstico , Proteómica/métodos , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Resultado del Tratamiento
10.
Chem Phys Lipids ; 146(2): 67-75, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17296172

RESUMEN

The aim of this study is to investigate the influence of ceramide head group architecture and free fatty acid (another main class of stratum corneum lipids) or protein (keratin), on the lamellar organization of the ceramide auto-associated in model films mimicking lipid organization within the stratum corneum. FTIR spectroscopy is a powerful technique for investigating the structure of such systems. This technique has already been used to characterize phase transitions of the SC and of related model systems. As temperature is known to modify the conformational order of lipids, we used it as a variable parameter to monitor the differences in the conformational stability of ceramides. Our study included four ceramides: ceramide 2, 3, 5 and 6 which differ by their head group architecture. Two kinds of lipid-lipid interactions were studied: non-polar and polar. We noted some structural factors which participated to the organizational behavior: insaturation of alkyl chain, alpha-hydroxyl on fatty acid moiety and sphingosine or phytosphingosine head group. There is a direct interaction of palmitic acid on alkyl chains organization and a weak interaction with polar head group in presence of keratin, both provoking a destabilization of the ceramidic orthorhombic organization.


Asunto(s)
Ceramidas/química , Epidermis/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Estructura Molecular
11.
J Chromatogr A ; 1117(2): 154-62, 2006 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-16620865

RESUMEN

The study of several structural variations (the length, the degree of unsaturation and hydroxylation of the alkyl chains, the number and nature of osidic residues) helped understand the behaviour of neutral glycosphingolipids (GSLs) on porous graphitic carbon stationary phase (PGC). Atmospheric pressure photoionization mass spectrometry (APPI) and tandem mass spectrometry were used to perform the detection and the identification of molecular species in positive mode where [M+H](+) and [M-H(2)O+H](+) ions provided structural information on the fatty acid and the sphingoid base. The retention of GSLs increased with the hydrocarboneous volume of their alkyl chains and with the number of osidic residues in agreement with hydrophobic properties and polar retention effect of graphite, respectively. The presence of polar groups, such as OH-group or double bond within alkyl chains, decreased their retention. The coupling of chromatography on PGC with APPI tandem mass spectrometry detection appeared a powerful technique to discriminate isobaric molecules. Isobaric solutes differing by the position of two double bonds or by the repartition of hydrocarboneous skeleton were discriminated according to their chromatographic comportment or their mass spectrum, respectively. Among isobaric molecules, only few structures differing by the nature of osidic residue were not discriminated (i.e. glucosylceramide and galactosylceramide with similar ceramide skeleton were co-eluted and no difference in mass spectra was observed).


Asunto(s)
Cromatografía Liquida/métodos , Glicoesfingolípidos/análisis , Grafito/química , Presión Atmosférica , Secuencia de Carbohidratos , Datos de Secuencia Molecular
12.
J Chromatogr A ; 1072(2): 149-57, 2005 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-15887484

RESUMEN

A general approach, still few exploited so far and never associated with microbore-LC, consisting of detection of various lipid classes (i.e. phospholipids, triglycerides, ceramides and glycosphingolipids) by non-covalent association with 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence probe is developed. This mode of detection was coupled with non-aqueous reversed-phase microbore-LC (C18) by using classical post-column fluorescence detection. The classical LC system was first adapted to microbore-chromatography (internal diameter 1 mm) without apparatus miniaturization of the solvent delivery system and the detection cell. For this purpose, the detection parameters (probe concentration, post-column flow rate, post-column reactor length and post-column system temperature) were optimized by a central composite design (CCD) using a mixture of phosphatidylcholine (PC) species as a lipid model and DPH (lambda(ex) = 350 nm, lambda(em) = 430 nm) as a fluorescence probe. The optimal conditions of detection for the various molecular species of PC were determined for a DPH concentration of 3.35 micromol/L, a post-column flow rate of 0.5 mL/min, a reactor length of 1.4 m and a temperature of 35 degrees C. The fluorescence response was linear over a wide range of PC species from 5 microg/mL to 100 microg/mL and the lower limit of detection (signal/noise = 3) was about 1 microg/mL, that is equivalent to evaporative light scattering detection (ELSD). Others molecular species of various classes of lipids, i.e. triglycerides, ceramides and glycosphingolipids were also easily detected. Thus, this study demonstrated the versatility of the proposed system of detection which was shown to be sensitive, easy to perform, non-destructive and allowed, in contrast to ELSD, for a linear response with various polarity lipid classes.


Asunto(s)
Cromatografía Liquida/métodos , Colorantes Fluorescentes/química , Lípidos/análisis , Sensibilidad y Especificidad
13.
Chem Phys Lipids ; 135(1): 55-68, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15854625

RESUMEN

The barrier function of skin resides in the lipid components of the stratum corneum, particularly their spatial organisation. FTIR spectroscopy has already been used as a relevant tool to study this lipid organisation: IR vibration band shifts have been attributed to the variations in lipid organisation induced by temperature. Our study included a stratum corneum model, composed of the three main lipids: palmitic acid as an example of fatty acids, cholesterol and ceramide III as an example of ceramide. Different films with various ratios of these lipids were studied. In our analytical strategy, the interest of using a chemometric analysis of global data obtained from ATR-FTIR spectra to highlight the main interactions involved in the molecular organisation of lipids has been demonstrated. Two kinds of interaction between the three main lipids have been shown: a non polar interaction between the long hydrocarbon chains and a polar interaction as the hydrogen bonding between polar functional groups. By varying the lipid ratio, we have shown first that the relative importance of each interaction was modified, second, that the induced modification of organisation can be detected by chemometric analysis of the ATR-FTIR spectra. The role of each kind of lipid in the organisation has been discussed. In conclusion, associating the ATR-FTIR with chemometric treatment is a promising tool: firstly, to understand the consequence of lipid relative compositions on the structural organisation of the stratum corneum, secondly, to show the relationship between lipid organisation and percutaneous penetration data. Indeed, this methodology will be transposed to in vivo studies with IR measurements through a probe.


Asunto(s)
Materiales Biomiméticos/química , Colesterol/química , Técnicas Químicas Combinatorias/métodos , Epidermis/química , Glicoesfingolípidos/química , Ácido Palmítico/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Animales , Materiales Biomiméticos/análisis , Colesterol/análisis , Glicoesfingolípidos/análisis , Humanos , Lípidos/análisis , Lípidos/química , Conformación Molecular , Ácido Palmítico/análisis , Transición de Fase
14.
Artículo en Inglés | MEDLINE | ID: mdl-15135109

RESUMEN

A simple method for the separation of the four major neutral glycosphingolipids, present in all human tissue, was developed. This gradient normal phase-HPLC method utilises a polyvinyl alcohol bonded stationary phase and an evaporative light-scattering detection (ELSD). Screening pure solvents in a binary gradient elution mode allowed, in a first step, to assess the behaviour of the studied solutes and to select the solvents for further mobile phase optimisation. The proportion of the remaining solvents was defined to reach a maximal resolution. The reduction of the analysis time and the enhancement of the signal were obtained by optimising the gradient slope and the flow-rate. Optimal levels of triethylamine and formic acid (TEA-FA) for the enhancement of the evaporative light scattering detector response were established at 0.1% (v/v). Thus, the optimal conditions for the separation of the four glycosphingolipids was obtained with a gradient elution from a 100% chloroform to a 100% acetone:methanol (90:10 (v/v)) mobile phase at 0.2 ml min-1, using a 10% min-1 gradient slope. Finally, this method was applied to detect the excess of one of the neutral sphingolipids, namely globotriaosylceramide (Gb3) in the urine of patients affected with Fabry disease. A liquid-liquid extraction of the sediments obtained from an aliquot of only ten ml of urine proved sufficient to detect the excess of Gb3 present in both hemizygote and heterozygote patients. In all, the ability of our method to detect abnormal amounts of Gb3 in urinary sediments could allow the diagnosis of weakly symptomatic Fabry patients in large screening programs


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Enfermedad de Fabry/orina , Glicoesfingolípidos/orina , Trihexosilceramidas/orina , Humanos , Sensibilidad y Especificidad
15.
Biomed Chromatogr ; 17(5): 297-305, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12884394

RESUMEN

The interests in liquid micro-chromatography (higher column efficiencies, increase in sensitivity) are now well established. The enhancement of fluorimetric response induced by the reduction of the inner diameter of columns (4.6, 3.0, 1.0 and 0.3 mm respectively) coupled with adapted detection cells to control the loss of efficiency (8 micro L for the two first columns and 100 nL for the two smaller ones) has been studied in the bioanalytical field, using the plasma determination of native fluorescent antibacterial agents: fluoroquinolones. Ten-fold enhancement of the signal can easily be obtained when substituting a 0.3 mm i.d. column and 100 nL detection cell for a 4.6 mm i.d. column, and 8 micro L detection cell. In addition to inner diameter reduction, the detection cell geometry appears to be an essential parameter to obtain the best enhancement of the recorded signal. Hence, the enhancement of signal with micro-chromatography with fluorimetric detection appears to be a compromise between column inner diameter and flow cell volume reduction.


Asunto(s)
Cromatografía Liquida/instrumentación , Fluoroquinolonas/sangre , Análisis de Inyección de Flujo , Fluoroquinolonas/química , Humanos , Miniaturización/instrumentación , Estructura Molecular , Sensibilidad y Especificidad , Espectrometría de Fluorescencia
16.
J Chromatogr A ; 928(2): 127-37, 2001 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-11587330

RESUMEN

Potentialities of polymerized vinyl alcohol on silica gel were assessed for class separation of simple lipids, sphingolipids, glyceroglycolipids and phospholipids by high-performance liquid chromatography. A screening of pure solvents in binary gradient elution and a chemometric approach was used to define a rugged two segment linear gradient formed from four solvents for total lipid class separation. Triethylamine and formic acid were added in all mobile phase components for acidic phospholipid separation and evaporative light scattering response enhancement. Simple analytical procedures are described for the analysis of complex lipid materials.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Lípidos/aislamiento & purificación , Alcohol Polivinílico/química , Luz , Dispersión de Radiación
17.
J Chromatogr A ; 917(1-2): 251-60, 2001 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-11403477

RESUMEN

A simple method using gas chromatography-mass spectrometry was applied to analyse structures of ceramides. Identification of trimethylsilylated ceramides were obtained in short analysis times (derivatization of ceramides in 30 min at room temperature and 20 min gas chromatography mass spectrometry run) even for complex mixtures. For example in ceramide Type III, 18 peaks were observed which represent 27 various structures. The coeluted compounds were ceramides containing the same functional groups and the same carbon number but with a different distribution on the two alkyl chains of the molecule. They were accurately differentiated by mass spectrometry. Therefore, 83 structures of trimethylsilylated ceramides were identified in 11 different commercial mixtures. For 52 structures of these, mass spectral data were not described in the literature, neither full mass spectra nor characteristic fragments.


Asunto(s)
Ceramidas/análisis , Ceramidas/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Estructura Molecular
20.
J Chromatogr A ; 883(1-2): 211-22, 2000 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-10910215

RESUMEN

This study was devoted to the development of an analytical method for ceramide analysis in packed subcritical fluid chromatography (pSubFC). Monofunctional grafted silica support was found to be more suitable for ceramide analysis. Five Kromasil columns were coupled and the parameters, temperature, pressure and percentage of organic modifier in CO2 were optimised, considering selectivity and analysis time. The final conditions were 31 degrees C, 6% of methanol (MeOH) and 13 MPa. In these conditions the selectivity for structural differences (methylene group, unsaturation or two different bases) were studied. As classically observed, the methylene selectivity decreased with the increase of the eluotropic strength. Moreover, unlike in non-aqueous reversed-phase liquid chromatography (NARP-LC), adding a further unsaturation and two further methylene groups on ceramide results to an increase of retention in pSubFC. Moreover, this last technique allowed to separate ceramides with the same total number of carbons containing unsaturated fatty acids, when the distribution of carbon number of the two chain is very different. These results had enabled to plot retention chart in order to predict ceramide structure in view to identify additional ceramide. This retention chart was finally compared with the one already obtained in NARP-LC.


Asunto(s)
Ceramidas/análisis , Cromatografía Liquida/métodos
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