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1.
BMC Public Health ; 22(1): 1470, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35915479

RESUMEN

BACKGROUND: Regular testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is an important strategy for controlling virus outbreaks on university campuses during the COVID-19 pandemic but testing participation rates can be low. The Residence-Based Testing Participation Pilot (RB-TPP) was a novel intervention implemented at two student residences on a large UK university campus over 4 weeks. The aim of the pilot was to increase the frequency of asymptomatic SARS-CoV-2 saliva testing onsite. This process evaluation aimed to determine whether RB-TPP was implemented as planned and identify implementation barriers and facilitators. METHODS: A mixed-methods process evaluation was conducted alongside the RB-TPP. Evaluation participants were students (opting in, or out of RB-TPP) and staff with a role in service provision or student support. Monitoring data were collected from the intervention delivery team and meeting records. Data were collected from students via online survey (n = 152) and seven focus groups (n = 30), and from staff via individual interviews (n = 13). Quantitative data were analysed descriptively and qualitative data thematically. Barriers and facilitators to implementation were mapped to the 'Capability, Opportunity, Motivation-Behaviour' (COM-B) behaviour change framework. RESULTS: Four hundred sixty-four students opted to participate in RB-TPP (98% of students living onsite). RB-TPP was implemented broadly as planned but relaxed social distancing was terminated early due to concerns relating to national escalation of the COVID-19 Delta variant, albeit testing continued. Most students (97.9%) perceived the period of relaxed social distancing within residences positively. The majority engaged in asymptomatic testing (88%); 46% (52% of testers) were fully compliant with pre-determined testing frequency. Implementation was facilitated by convenience and efficiency of testing, and reduction in the negative impacts of isolation through opportunities for students to socialise. Main barriers to implementation were perceived mixed-messages about the rules, ambivalent attitudes, and lack of adherence to COVID-19 protective measures in the minority. CONCLUSIONS: This process evaluation identifies factors that help or hinder the success of university residence-based outbreak prevention and management strategies. RB-TPP led to increased rates of SARS-CoV-2 testing participation among students in university residences. Perceived normalisation of university life significantly enhanced student mental wellbeing. The complexity and challenge generated by multiple lines of communication and rapid adaptions to a changing pandemic context was evident. TRIAL REGISTRATION NUMBER: UKAS 307727-02-01; Pre-results. CLINICALTRIALS: gov Identifier: NCT05045989 ; post-results (first posted, 16/09/21). ETHICAL APPROVAL: Faculty of Medicine & Health Sciences Research Ethics Committee, University of Nottingham (Ref: FMHS 96-0920).


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , COVID-19/prevención & control , Prueba de COVID-19 , Humanos , Pandemias/prevención & control , Reino Unido/epidemiología , Universidades
3.
Gynecol Obstet Fertil Senol ; 50(2): 142-150, 2022 Feb.
Artículo en Francés | MEDLINE | ID: mdl-34562643

RESUMEN

INTRODUCTION: Organized and individual breast screening have been accompanied by an increase in the detection of "atypical breast lesions (ABL)". Recently, the NOMAT multicenter study proposed a predictive model of the risk of developing breast cancer after detection of an ABL in order to avoid surgical removal of "low-risk" lesions. It also aimed to provide information on psychological experience, in particularly anxiety, to assist in the shared medical decision process. METHODS: Three hundred women undergoing surgery for ABL were included between 2015 and 2018 at 18 French centers. Women completed questionnaires before and after surgery assessing their level of anxiety (STAI-State, STAI-Trait), their level of tolerance to uncertainty, their perceived risk of developing a breast cancer, and their satisfaction with the management care. RESULTS: One hundred nighty nine patients completed the STAI-Status before and after surgery. Overall, a decrease in anxiety level (35.4 vs 42.7, P<0.001) was observed. Anxious temperament and greater intolerance to uncertainty were significantly associated swith decreased anxiety (33%), whereas younger age was associated with increased anxiety (8%). CONCLUSION: Surgery for ABL seems to be associated with only a few cases with an increase in anxiety and seems to increase the perception of the risk of developing breast cancer. Taking into account the psychological dimension remains in all cases essential in the process of shared therapeutic decision.


Asunto(s)
Ansiedad , Neoplasias de la Mama , Ansiedad/diagnóstico , Ansiedad/psicología , Mama , Neoplasias de la Mama/diagnóstico , Femenino , Humanos , Estudios Prospectivos , Encuestas y Cuestionarios
4.
Mol Biol Cell ; 32(20): ar10, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34379441

RESUMEN

Mutations in the genes that encode α- and ß-tubulin underlie many neurological diseases, most notably malformations in cortical development. In addition to revealing the molecular basis for disease etiology, studying such mutations can provide insight into microtubule function and the role of the large family of microtubule effectors. In this study, we use budding yeast to model one such mutation-Gly436Arg in α-tubulin, which is causative of malformations in cortical development-in order to understand how it impacts microtubule function in a simple eukaryotic system. Using a combination of in vitro and in vivo methodologies, including live cell imaging and electron tomography, we find that the mutant tubulin is incorporated into microtubules, causes a shift in α-tubulin isotype usage, and dramatically enhances dynein activity, which leads to spindle-positioning defects. We find that the basis for the latter phenotype is an impaired interaction between She1-a dynein inhibitor-and the mutant microtubules. In addition to revealing the natural balance of α-tubulin isotype utilization in cells, our results provide evidence of an impaired interaction between microtubules and a dynein regulator as a consequence of a tubulin mutation and sheds light on a mechanism that may be causative of neurodevelopmental diseases.


Asunto(s)
Dineínas/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Tubulina (Proteína)/genética , Dineínas/genética , Tomografía con Microscopio Electrónico/métodos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Microtúbulos/metabolismo , Mutación , Trastornos del Neurodesarrollo/metabolismo , Neurogénesis , Fenotipo , Receptores Mitogénicos/genética , Receptores Mitogénicos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Huso Acromático/metabolismo , Tubulina (Proteína)/metabolismo
6.
Nanoscale ; 6(10): 5138-45, 2014 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-24643337

RESUMEN

A great number of studies focus their interest on the photophysical properties of fluorescent hybrid gold nanoparticles for potential applications in biotechnologies such as imaging and/or treatment. Spherical gold nanoparticles are known to quench a chromophore fluorescent signal, when moieties are located in their close vicinity. The use of a polymer spacer on such a system allowed only partial recovery of the dye emission by controlling the surface to dye distance. Gold-based anisotropic sharp nanostructures appear to exhibit more interesting features due to the strong electric field generated at their edges and tips. In this paper, a complete study of hybrid fluorescent bipyramidal-like gold nanostructures is presented. We describe the chemical synthesis of gold bipyramids functionalized with fluorescent water-soluble polymers and their photophysics both in solution and on a single object. We show that the use of a bipyramidal shape instead of a spherical one leads to total recovery of the fluorescence and even to an enhancement of the emission of the dyes by a factor of 1.4.

7.
Food Chem Toxicol ; 49(7): 1565-71, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21515331

RESUMEN

This study was designed to investigate the hypothesis that the toxic effects of di(2-ethylhexyl)phthalate (DEHP), the most abundantly used plasticizer and ubiquitous environmental contaminant that cause alterations in endocrine and spermatogenic functions in animals is mediated through the induction of reactive oxygen species (ROS) and activation of nuclear p53 and p21 proteins in LNCaP human prostate adenocarcinoma cell line. Protective effects of two selenocompounds, sodium selenite (SS) and selenomethionine (SM) were also examined. It was demonstrated that 24 h exposure of the cells to 3 mM DEHP or its main metabolite, mono(2-ethylhexyl)phthalate (MEHP, 3 µM) caused strongly amplified production of ROS. Both SS (30 nM) and SM (10 µM) supplementations reduced ROS production, and p53 and p21 activation that induced significantly only by MEHP-exposure. The overall results of this study indicated that the induction of oxidative stress is one of the important mechanisms underlying the toxicity of DEHP and this is mainly through the effects of the metabolite, MEHP. Generated data also emphasized the critical role of Se in modulation of intracellular redox status, implicating the importance of the appropriate Se status in cellular response against testicular toxicity of phthalates.


Asunto(s)
Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Dietilhexil Ftalato/análogos & derivados , Especies Reactivas de Oxígeno/metabolismo , Selenometionina/farmacología , Selenito de Sodio/farmacología , Proteína p53 Supresora de Tumor/metabolismo , Línea Celular Tumoral , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Citoprotección/efectos de los fármacos , Dietilhexil Ftalato/toxicidad , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Estrés Oxidativo/efectos de los fármacos , Ácidos Ftálicos/toxicidad , Plastificantes/toxicidad , Espermatogénesis/efectos de los fármacos , Enfermedades Testiculares/inducido químicamente , Enfermedades Testiculares/tratamiento farmacológico , Testículo/citología , Proteína p53 Supresora de Tumor/genética
8.
Eur J Clin Nutr ; 64(10): 1057-64, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20664619

RESUMEN

BACKGROUND/OBJECTIVES: Few studies have been conducted on determinants of serum zinc concentration, especially in France. The aim of this study was to investigate the relationships between serum zinc concentrations, and age, education, living area and life style in a large sample cohort of French adults. SUBJECTS/METHODS: Blood samples were collected after 12-h fasting in French adults (7448 women, 35-65 years old and 4926 men, 45-65 years old) participating to the SUpplementation in AntioXidant VItamins and Minerals cohort at enrolment. Serum zinc was determined by flame atomic absorption. RESULTS: Serum zinc concentration was lower in women (mean: 12.9 µmol/l, 95% confidence interval: 9.2-16.6 µmol/l) compared with men (mean: 13.4 µmol/l, 95% confidence interval: 9.7-17.1 µmol/l, P<0.0001). In total, 10% of the women showed serum zinc values <10.7 µmol/l and 10% of the men showed serum zinc values <11.3 µmol/l. Age was negatively associated with serum zinc only in men (P=0.001). In women, a positive association between smoking and serum zinc concentration (P=0.0003), and a negative relationship between highest education level and serum zinc concentration (P=0.01) were observed. With regard to geographical areas, the highest serum zinc concentrations were found in the Center, and the lowest in the Southwest of France for both men and women. The association between serum zinc concentrations and food categories or macronutrient intake disappeared after stratifying by gender. CONCLUSIONS: Age, gender and geographic area seem the main determinants of serum zinc concentrations in this study.


Asunto(s)
Estilo de Vida , Zinc/sangre , Adulto , Anciano , Envejecimiento , Estudios de Cohortes , Enfermedades Carenciales/epidemiología , Dieta , Registros de Dieta , Escolaridad , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Características de la Residencia , Caracteres Sexuales , Fumar , Espectrofotometría Atómica , Zinc/deficiencia
9.
Med Trop (Mars) ; 70(1): 13-7, 2010 Feb.
Artículo en Francés | MEDLINE | ID: mdl-20337109

RESUMEN

The purpose of this report is to describe the experience of a specialized medico-surgical ENT team sent to hospital centers in Atalaha and Tulear, Madagascar by a nonprofit organization called "Terre rouge" from the Reunion Island. In three separate short-term missions, a total of 93 patients received care. Discussion focuses on the particular pathological, cultural, and pedagogical features of the Island and on the resources that were deployed during the missions. Providing ENT care in district hospitals in Madagascar requires adaptation to the difficult climatic conditions, poor hospital facilities (infrastructure, equip ment, and personnel), and advanced stage of diseases. To ensure continuous access to ENT care, it will be necessary to provide practical and didactic training for healthcare personnel in the country.


Asunto(s)
Misiones Médicas , Enfermedades Otorrinolaringológicas/terapia , Grupo de Atención al Paciente , Femenino , Hospitales de Distrito , Humanos , Madagascar , Masculino , Organizaciones sin Fines de Lucro , Estudios Retrospectivos
10.
Acta Biol Hung ; 60(1): 79-88, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19378926

RESUMEN

The research was conducted to investigate the toxic effects of cadmium chloride (CdCl2), administered during gestation period on female Wistar rats. Pregnant rats received CdCl2 (20 mg/l, orally) from Day 6 to Day 19 of pregnancy. Results showed that Cd treatment induced a decrease in body weight gain. The relative liver weight increased significantly, with a marked decrease of glycogen and total lipids content. The administration of Cd induced hepatotoxicity as indicated by elevations in plasma alanine aminotransferase (ALT), aspartate aminotransferase and lactate dehydrogenase (LDH) activities (p < 0.05). Treatment with CdCl2 caused a significant (p < 0.05) increase in glucose. A significant increase was observed in the level of MDA and 8-oxodGuo tissues in the cadmium-exposed group compared to the control group (p < 0.05). Results showed that cadmium given to dams led to an oxidative stress and DNA damage in tissues of pregnant rats.


Asunto(s)
Cloruro de Cadmio/toxicidad , Daño del ADN/efectos de los fármacos , Riñón/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Administración Oral , Alanina Transaminasa/metabolismo , Animales , Antioxidantes/metabolismo , Aspartato Aminotransferasas/metabolismo , Cadmio/toxicidad , Cloruro de Cadmio/administración & dosificación , Intoxicación por Cadmio/metabolismo , Intoxicación por Cadmio/patología , Femenino , Riñón/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Hígado/metabolismo , Hígado/patología , Tamaño de los Órganos/efectos de los fármacos , Estrés Oxidativo , Embarazo , Complicaciones del Embarazo/metabolismo , Complicaciones del Embarazo/patología , Ratas , Ratas Wistar , Aumento de Peso/efectos de los fármacos
11.
Lab Chip ; 8(10): 1713-22, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18813395

RESUMEN

DNA repair mechanisms constitute major defences against agents that cause cancer, degenerative disease and aging. Different repair systems cooperate to maintain the integrity of genetic information. Investigations of DNA repair involvement in human pathology require an efficient tool that takes into account the variety and complexity of repair systems. We have developed a highly sensitive damaged plasmid microarray to quantify cell lysate excision/synthesis (ES) capacities using small amounts of proteins. This microsystem is based on efficient immobilization and conservation on hydrogel coated glass slides of plasmid DNA damaged with a panel of genotoxic agents. Fluorescent signals are generated from incorporation of labelled dNTPs by DNA excision-repair synthesis mechanisms at plasmid sites. Highly precise DNA repair phenotypes i.e. simultaneous quantitative measures of ES capacities toward seven lesions repaired by distinct repair pathways, are obtained. Applied to the characterization of xeroderma pigmentosum (XP) cells at basal level and in response to a low dose of UVB irradiation, the assay showed the multifunctional role of different XP proteins in cell protection against all types of damage. On the other hand, measurement of the ES of peripheral blood mononuclear cells from six donors revealed significant diversity between individuals. Our results illustrate the power of such a parallelized approach with high potential for several applications including the discovery of new cancer biomarkers and the screening of chemical agents modulating DNA repair systems.


Asunto(s)
Reparación del ADN , Plásmidos , Línea Celular Transformada , Células HeLa , Humanos , Espectrometría de Fluorescencia
12.
Nucleic Acids Symp Ser (Oxf) ; (52): 249-50, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18776347

RESUMEN

An original oligonucleotide-array, coupled with SPR-imaging detection, has been developed to study biological interactions between DNA base lesions and DNA repair enzymes. This bioanalytical tool constitutes an efficient screening platform to quantify DNA repair activities and to search for new DNA repair inhibitors.


Asunto(s)
Daño del ADN , Reparación del ADN , ADN-Formamidopirimidina Glicosilasa/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Resonancia por Plasmón de Superficie , 8-Hidroxi-2'-Desoxicoguanosina , Desoxiadenosinas/química , Desoxiguanosina/análogos & derivados , Desoxiguanosina/química , Proteínas de Escherichia coli/metabolismo
13.
Diabetes Metab ; 34(2): 148-54, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18329309

RESUMEN

OBJECTIVE: Fructose consumption is increasing worldwide and is likely to play a role in metabolic disorders. Dietary fructose is often recommended for diabetic patients, as this form of carbohydrate leads to a lower postprandial rise in plasma glucose and insulin. However, fructose contributes to the generation of free radicals. The aim of this work was to investigate the acute effects of a fructose load in patients with type 2 diabetes mellitus (T2DM), compared with healthy controls, on several metabolic oxidative biomarkers, particularly plasma 15-F2t isoprostanes (15-F2t isoPs). RESEARCH DESIGN AND METHODS: Six T2DM patients and six healthy subjects were recruited. All patients underwent a single fructose tolerance test (75 g of anhydrous fructose). Plasma 15-F2t isoPs concentrations, plasma total antioxidant capacity (TAS) and thiobarbituric acid reactive substances (TBARS) were measured at baseline, and at 60, 120, 180 and 240 min after fructose absorption. RESULTS: Baseline plasma 15-F2t isoPs concentrations were significantly increased in T2DM patients compared with controls (310+/-47 versus 237+/-20 pg/mL, respectively; P<0.01) and rose significantly (P<0.01) to 414+/-45 pg/mL in diabetic patients. No change in TAS or TBARS was observed in either group. CONCLUSION: Plasma 15-F2t isoPs are increased during acute fructose loading in T2DM. Knowing the potentially deleterious effect of plasma 15-F2t isoPs-in particular, vascular lesions-and in light of our results, it is necessary to reconsider fructose consumption in T2DM patients, as we can now show, for the first time, a possible association between acute fructose loading and deleterious effects in such patients.


Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Dinoprost/análogos & derivados , Fructosa/farmacología , Adulto , Glucemia/análisis , Índice de Masa Corporal , Colesterol/sangre , Dinoprost/sangre , Ayuno , Femenino , Humanos , Lactatos/sangre , Lipoproteínas/sangre , Masculino , Persona de Mediana Edad , Valores de Referencia , Triglicéridos/sangre
14.
Eur Respir J ; 31(5): 1046-53, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18256067

RESUMEN

Antioxidant counteraction of oxidative stress has been poorly explored in obstructive sleep apnoea (OSA). Serum albumin is a major antioxidant agent and structural modifications induced by glucose or free radicals impair its antioxidant properties. The aim of the present study was to compare antioxidant capacities and structural changes of albumin in nonobese OSA patients and healthy volunteers. Albumin structural changes were studied by quenching of fluorescence in the presence of acrylamide. Albumin thiols and fructosamines, reflecting oxidation- and glycation-induced changes in serum albumin, respectively, were assessed. Albumin structural changes were demonstrated by a significant decrease in quenching of fluorescence in OSA patients. Oxidation, resulting in a significant decrease in thiol groups (3.7+/-0.7 versus 2.3+/-0.4 micromol x g(-1) protein), and glycation, associated with a significant increase in fructosamines (226.6+/-27 versus 286+/-44.4 micromol x L(-1)), were found when comparing healthy volunteers with OSA patients. There was a significant relationship between both parameters and sleep apnoea severity. After continuous positive airway pressure intervention, albumin thiol groups were reassessed in seven of the 16 OSA patients and increased significantly from 2.25+/-0.39 to 2.79+/-0.31 micromol x g(-1) protein. Obstructive sleep apnoea patients demonstrated a reduction in serum albumin antioxidant properties that may aggravate oxidative stress and, thus, contribute to cardiovascular and metabolic morbidities.


Asunto(s)
Antioxidantes/farmacología , Albúmina Sérica/farmacología , Apnea Obstructiva del Sueño/fisiopatología , Adulto , Antioxidantes/química , Antioxidantes/metabolismo , Estudios de Casos y Controles , Presión de las Vías Aéreas Positiva Contínua , Fructosamina/sangre , Glicosilación , Humanos , Isoprostanos/orina , Persona de Mediana Edad , Oxidación-Reducción , Albúmina Sérica/química , Albúmina Sérica/metabolismo , Apnea Obstructiva del Sueño/sangre , Compuestos de Sulfhidrilo/sangre
15.
Zygote ; 16(1): 9-13, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18221576

RESUMEN

Careful attention has been focused recently on DNA quality in human IVF. Therefore a variety of methods has been developed to evaluate DNA integrity, especially concerning fragmentation. Using liquid chromatography and mass spectrometry (LC/MS/MS) for our best sperm samples, we have established reference values for several oxidative lesions, in order to gain insights into the cause of DNA lesions. Besides 8-oxodeoxyguanosine, we found rather high levels of two ethenonucleosides: 1,N6-ethenoadenosine and 1,N2-ethenoguanosine. These compounds probably arise from a reaction with 4-hydroxy-2-nonenal, the main aldehyde compound released during lipid peroxidation, or after occupational exposure to vinyl chloride. The quantity of chlorinated bases detected is low. All of this decay has to be repaired by the oocytes at the time of fertilization or immediately after. This aspect should not be overlooked in assisted reproductive technology, in order to understand risks and limitations.


Asunto(s)
Adenosina/análogos & derivados , Aductos de ADN/metabolismo , Daño del ADN , Desoxiguanosina/análogos & derivados , Guanosina/análogos & derivados , Espermatozoides/metabolismo , 8-Hidroxi-2'-Desoxicoguanosina , Adenosina/metabolismo , Cromatografía Líquida de Alta Presión , Desoxiguanosina/metabolismo , Guanosina/metabolismo , Humanos , Masculino , Espectrometría de Masas , Estrés Oxidativo
16.
Eur J Clin Nutr ; 62(10): 1155-61, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17622261

RESUMEN

OBJECTIVE: To measure the correlations between habitual intakes of individual n-6 and n-3 polyunsaturated fatty acids (PUFA) and their percentages in total plasma fatty acids in a population of adult men and women. SUBJECTS/METHODS: Two hundred and seventy-six men and 257 women aged 45-60 (men) or 35-60 (women) at baseline, volunteers of the French SU.VI.MAX cohort. Fifteen 24-h record questionnaires were used to estimate the habitual intake of energy, total fat and linoleic, alpha-linolenic acid, arachidonic, eicosapentaenoic (EPA), n-3 docosapentaenoic (DPA) and docosahexaenoic (DHA) acids. Fatty acid composition of fasting plasma total lipids has been determined at baseline. RESULTS: Dietary intakes of linoleic acid, arachidonic acid, EPA and DHA were weakly but significantly correlated (0.16

Asunto(s)
Dieta , Grasas Insaturadas en la Dieta/administración & dosificación , Ácidos Grasos Omega-3/sangre , Ácidos Grasos Omega-6/sangre , Adulto , Biomarcadores/sangre , Estudios de Cohortes , Estudios Transversales , Grasas Insaturadas en la Dieta/metabolismo , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Grasos Omega-6/administración & dosificación , Conducta Alimentaria , Femenino , Francia , Humanos , Ácido Linoleico/administración & dosificación , Ácido Linoleico/metabolismo , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Ácido alfa-Linolénico/administración & dosificación , Ácido alfa-Linolénico/metabolismo
17.
Ann Biol Clin (Paris) ; 65(4): 393-8, 2007.
Artículo en Francés | MEDLINE | ID: mdl-17627920

RESUMEN

Total plasma homocysteine emerged in the past few years as an independent risk factor for cardiovascular diseases. This test is now currently prescribed for the diagnosis of unexplained thrombosis in young adults or recurrent thrombosis in patients with arteriopathy. This sulphured amino-acid is an important intermediate in transsulfuration and remethylation pathways of methionine metabolism. Within the context of a collaboration between Monastir and Grenoble Universities and because a gas chromatograph mass spectrometer (GC-MS) instrument was available in Monastir, we proposed to transpose a GC-MS method previously developed in Grenoble's hospital for this parameter and to validate it by comparison with the liquid chromatography tandem mass spectrometry (LC-MS-MS) method, used at present. Analytical performances were good: detection limit 0.4 micromol/L and linear range up to 4 mg/L (29.6 micromol/L), and between-run and within-run precision with coefficients of variation < 5% and < 8 %, respectively. The comparison with LC-MS-MS method showed a good correlation (y = 0.9874 x -0.208; r(2) = 0.84). Mean difference from LC-MS-MS was -0.4 micromol/L. Plasma concentrations of homocysteine (mean + SD) determined among Tunisian adults, 29 men, 27 women, of the same age were respectively: 11.6 +/- 2.4 micromol/L and 10.1 +/- 2.7 micromol/L, p = 0.025. This method is now currently used to evaluate tHcy concentration in patients with risk factors for cardiovascular disease.


Asunto(s)
Homocisteína/sangre , Adulto , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/epidemiología , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Espectrometría de Masas , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad , Trombosis/epidemiología , Túnez
18.
Br J Dermatol ; 157(1): 26-32, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17578435

RESUMEN

BACKGROUND: Sun irradiation causes skin ageing and cancer through the accumulation of damage to cell components. Intrinsic ageing is also associated with accumulation of oxidized macromolecules. OBJECTIVES: In this study we investigated the effects of sun exposure on response to an acute in vitro oxidative stress (H(2)O(2)) using normal human fibroblasts prepared from biopsies from 10 volunteers taken from sun-protected and sun-exposed sites. METHODS: Time-course experiments measuring repair of DNA strand-breaks and formamidopyrimidine DNA N-glycosylase-sensitive sites were conducted using the single-cell gel electrophoresis (comet) assay. RESULTS: Our results demonstrated that repair of strand-breaks was slower in sun-exposed compared with sun-protected cells. Interestingly, ageing was also associated with decreased DNA repair capacities for single-strand breaks in both sun-exposed and sun-protected cells whereas for formamidopyrimidine glycosylase (Fpg)-sensitive sites, this feature was in evidence only in sun-protected cells. Smoking, associated with age, was shown to have a markedly negative impact on DNA repair. CONCLUSIONS: Taken together our data suggest that stresses like ageing, sun exposure and smoking might have an additive effect contributing to the overall heterogeneity and decrease of DNA repair capacities in human cells and so increase the danger of sun exposure for health. They also emphasize the importance of the quality of the biological samples when repair studies on skin cells are to be conducted.


Asunto(s)
Daño del ADN/efectos de la radiación , Reparación del ADN/fisiología , Estrés Oxidativo/fisiología , Envejecimiento de la Piel/fisiología , Fumar/efectos adversos , Luz Solar/efectos adversos , Adulto , Factores de Edad , Daño del ADN/fisiología , Reparación del ADN/efectos de la radiación , Femenino , Fibroblastos/fisiología , Fibroblastos/efectos de la radiación , Humanos , Persona de Mediana Edad , Fumar/metabolismo , Fumar/fisiopatología
19.
Ann Pharm Fr ; 64(6): 390-6, 2006 Nov.
Artículo en Francés | MEDLINE | ID: mdl-17119468

RESUMEN

Oxidative stress is an abnormal phenomenon occurring inside our cells or tissues when production of oxygen radicals exceeds their antioxidant capacity. Excess of free radicals damage essential macromolecules of the cell, leading to abnormal gene expression, disturbance in receptor activity, proliferation or cell dye, immunity perturbation, mutagenesis, protein or lipofushin deposition. Numerous human diseases involve during the pathological process such a stress, localized or general (in the same way as inflammation). In many serious diseases such as cancer, ocular degeneration (age related macular degeneration or cataract), neurodegenerative diseases (ataxia, amyotrophic lateral sclerosis, Alzheimer's disease) stress is the factor original. In familial amyotrophic lateral sclerosis the genetic abnormality occurred an abnormal coding for an antioxidant enzyme, copper-zinc super oxide dismutase. In various other diseases oxidative stress occur secondary to the initial disease but plays an important in role immune or vascular complications. This is the case in infectious disease such as AIDS or septic shock, Parkinson's disease or renal failure. So antioxidant treatment seems logical to be tested in these pathologies. But they have to be applied early in the process, before irreversible mechanisms. They need also to be prescribed at low doses as baseline free radical production have to be preserved to maintain useful activity that cannot be suppressed.


Asunto(s)
Enfermedad , Estrés Oxidativo/fisiología , Humanos , Oxidantes/metabolismo
20.
Arch Mal Coeur Vaiss ; 99(7-8): 665-8, 2006.
Artículo en Francés | MEDLINE | ID: mdl-17061440

RESUMEN

The object of this work was to determine the risk of hypertension after 6.5 years'- follow-up of supplementation in vitamins and antioxidant minerals at nutritional doses in the SU.VI.MAX trial. The authors also studied the association with plasma concentrations of antioxidants at inclusion and at long term. This was a randomised nutritional primary prevention study including 5086 adults of the SU.VI.MAX trial. After 6.5 years' follow-up, no effect of supplementation on the risk of developing hypertension could be shown compared with the placebo group: odds ratios (OR IC 95%): 1.04 (0.87-1.23) in men and 1.10 (0.95-1.29) in women. Besides, in the male 2nd and 3rd tertiles of serum beta-carotene levels at inclusion the risk of hypertension was lower [multivariate OR: 0.70 (0.44-1.12) and 0.53 (0.33-0.86) for placebo, and 0.59 (0.37-0.94) and 0.67 (0.42-1.07) for the supplemented groups]. The authors conclude that, despite a reverse relationship in men between the plasma concentrations of beta-carotene and the risk of hypertension, supplementation in antioxidants at nutritional doses had no effect on the risk of developing hypertension after 6.5 years' follow-up.


Asunto(s)
Antioxidantes/uso terapéutico , Suplementos Dietéticos , Hipertensión/epidemiología , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , beta Caroteno/sangre
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