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1.
Health Promot Int ; 33(2): 279-287, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-27694228

RESUMEN

The World Health Organization recommend the Equity-Focused Health Impact Assessment (HIA) as a means to assess the impact of social and economic policies on the health of populations, and acknowledges their contribution to health inequality. We describe the application of the Equity-focused Impact Assessment methodology on the Portuguese law on Smoking Prevention and Tobacco Control (Law No. 37/2007). A rapid assessment was carried out to issue recommendations which could be incorporated into the law during a revision in 2014. Quantitative (consumption and health status indicators; equity analysis) and qualitative (Focus Group) approaches were taken to evaluate the impact of the law and formulate recommendations. Young people, men and women of low socioeconomic status, and pregnant women were identified as requiring specific and appropriate interventions to prevent smoking and support smoking cessation.


Asunto(s)
Evaluación del Impacto en la Salud/métodos , Indicadores de Salud , Prevención del Hábito de Fumar , Productos de Tabaco/legislación & jurisprudencia , Comercio/legislación & jurisprudencia , Femenino , Evaluación del Impacto en la Salud/legislación & jurisprudencia , Humanos , Masculino , Portugal , Pobreza , Cese del Hábito de Fumar
2.
Diabetes Metab Res Rev ; 29(4): 285-95, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23390053

RESUMEN

The relation between cancer and metabolic disorders was recognized several decades ago, but the underlying mechanisms involved in cancer development and progression remain obscure. In the last years, many groups have been studying systemic adipose tissue markers in cancer patients. However, few consistent results were obtained. On the other hand, several studies revealed many aspects of adipose tissue physiology in obesity. Nowadays, it is recognized that excessive lipid uptake in adipocytes leads to hypertrophy and consequently to metabolic dysregulation, hypoxia, inflammation, impaired adipocytokine expression and angiogenesis, insulin resistance and macrophage recruitment. In obese patients, tumours commonly colocalize with excessive adipose tissue accumulation, and most of the features of hypertrophic adipose tissue are observed in cancer patients, namely breast and colon. This review aimed to summarize pathological adipose tissue alterations that may contribute to cancer aetiology and development.


Asunto(s)
Tejido Adiposo/patología , Neoplasias/etiología , Obesidad/complicaciones , Animales , Humanos , Neoplasias/diagnóstico
3.
Nutr Metab Cardiovasc Dis ; 23(12): 1223-30, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23642929

RESUMEN

BACKGROUND AND AIMS: The influence of lifestyle is well documented, especially the diet regime, in the development of type 2 diabetes (T2D) and associated cardiovascular diseases. Diabetic patients have increased risk of suffering cardiac ischemia and impaired response to such accidents. Methylglyoxal (MG) circulates at high concentration in diabetics' blood and is linked to the development of diabetes chronic complications. We propose that besides promoting the cardiovascular disease, MG may also negatively regulate the endogenous cardioprotection pathways after ischemia. METHODS AND RESULTS: We performed a comparative study between three animal groups: normal Wistar (W), type 2 diabetic non-obese Goto-Kakizaki (GK) and normal rats submitted to MG chronic administration (3 months) with gradually enhanced concentration, up to 75 mg/Kg (WMG). Hearts were submitted to different experimental conditions: control, ischemia and ischemia-reperfusion. Levels of oxidative stress markers, advanced glycation end-products (AGEs) and their receptors (RAGEs) were evaluated. The serine/threonine protein kinase Akt (Akt), crucial for cardiomyocytes recovery after ischemia, and apoptosis markers were also assessed. Levels of MG, systemic and cardiac oxidative stress markers, AGEs and RAGEs were similar in GK and WMG groups. Akt protein was negatively regulated by MG, leading to impaired apoptotic markers. CONCLUSION: Chronic MG administration to normal rodents mimicked most diabetic alterations, being associated with the development of cardiovascular disease and the impairment of survival pathways. Our results demonstrate the negative effect of MG rich diet in healthy animals and suggest the potential of methylglyoxal as a therapeutic target in diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Corazón/efectos de los fármacos , Isquemia Miocárdica/inducido químicamente , Piruvaldehído/efectos adversos , Animales , Apoptosis/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Productos Finales de Glicación Avanzada/metabolismo , Corazón/fisiopatología , Masculino , Estrés Oxidativo/efectos de los fármacos , Piruvaldehído/administración & dosificación , Ratas , Ratas Wistar
4.
Eur Phys J E Soft Matter ; 34(1): 8, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21274676

RESUMEN

We report on an experimental study of the structures presented by urethane/urea elastomeric films without and with ferromagnetic nanoparticles incorporated. The study is made by using the X-ray diffraction, nuclear magnetic resonance (NMR), optical, atomic and magnetic force (MFM) microscopy techniques, and mechanical assays. The structure of the elastomeric matrix is characterized by a distance of 0.46 nm between neighboring molecular segments, almost independent on the stretching applied. The shear casting performed in order to obtain the elastomeric films tends to orient the molecules parallel to the flow direction thus introducing anisotropy in the molecular network which is reflected on the values obtained for the orientational order parameter and its increase for the stretched films. In the case of nanoparticles-doped samples, the structure remains nearly unchanged although the local order parameter is clearly larger for the undoped films. NMR experiments evidence modifications in the molecular network local ordering. Micrometer size clusters were observed by MFM for even small concentration of magnetic particles.


Asunto(s)
Elastómeros/química , Hierro/química , Nanopartículas del Metal/química , Urea/química , Uretano/química , Espectroscopía de Resonancia Magnética , Microscopía de Fuerza Atómica , Tamaño de la Partícula , Dispersión del Ángulo Pequeño , Propiedades de Superficie , Difracción de Rayos X
5.
Radiol Med ; 116(4): 634-43, 2011 Jun.
Artículo en Inglés, Italiano | MEDLINE | ID: mdl-21424316

RESUMEN

PURPOSE: The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique. MATERIALS AND METHODS: Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated contrast-specific software [contrast tuned imaging (CnTI)]. Of these lesions, five were excluded from the analysis because the definitive diagnosis was not available (in two cases, the follow-up was still in progress, whereas in the remaining three, there was no follow-up). Our study, therefore, is based on 61 surgically excised lesions that were confirmed to be neurinomas by histology, which is regarded as the gold standard. RESULTS: In 41/61 cases (67.2%), we identified an enhancement pattern that we termed reticular owing to the interweaving of blood vessels, of which two subtypes were identified depending on whether the interwoven vessels were densely or sparsely packed: loose-knit reticular in 18/41, and tight-knit reticular in 23/41. In 20/61 (32.8%) cases, we observed a vascular pattern of diffuse heterogeneous enhancement, which was divided into two subtypes based on the presence of one (7/20) or more (13/20) avascular areas. CONCLUSIONS: Results showed that all neurinomas studied could be divided into two groups according to the type of enhancement pattern observed: reticular or diffuse heterogeneous.


Asunto(s)
Medios de Contraste , Neurilemoma/diagnóstico por imagen , Neoplasias del Sistema Nervioso Periférico/diagnóstico por imagen , Fosfolípidos , Hexafluoruro de Azufre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neurilemoma/irrigación sanguínea , Neoplasias del Sistema Nervioso Periférico/irrigación sanguínea , Ultrasonografía , Adulto Joven
6.
Exp Physiol ; 95(9): 955-70, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20562294

RESUMEN

Progressive microvascular complications are a main feature of diabetes and are associated with impairment of the angiogenic response. Methylglyoxal (MGO) has been implicated in the molecular events that lead to endothelial dysfunction in diabetes. In this study, we hypothesize that increased levels of MGO disrupt the ratio of vascular endothelial growth factor (VEGF) to angiopoietin 2 (Ang 2) secreted by retinal pigment epithelial (RPE) cells, which provides a key destabilizing signal that leads to apoptosis and decreased proliferation of retinal endothelial cells. Indeed, we show that MGO increases the levels of Ang 2 and dramatically decreases the levels of VEGF secreted by RPE cells in response to hypoxia. Downregulation of VEGF is likely to be related to decreased hypoxia-inducible factor-1alpha (HIF-1alpha) protein levels and HIF-1 transcriptional activity. Data further show that MGO-induced imbalance in the VEGF/Ang II ratio significantly changes the levels of BAX and Bcl-2 in endothelial cells. Moreover, this imbalance is accompanied by an increase in the activity of caspase-3 and decreased proliferation of endothelial cells. Data obtained in cell culture systems are consistent with observations in retinas of diabetic animals, where increased availability of MGO is associated with changes in distribution and levels of HIF-1alpha, VEGF and Ang 2 and increased microvascular permeability. In conclusion, the MGO-induced imbalance in the VEGF/Ang 2 ratio secreted by retinal epithelial cells activates apoptosis and decreases proliferation of retinal endothelial cells, which are likely to contribute to endothelial dysfunction in diabetic retinopathy.


Asunto(s)
Angiopoyetina 2/metabolismo , Retinopatía Diabética/metabolismo , Endotelio Vascular/metabolismo , Células Epiteliales/metabolismo , Piruvaldehído/metabolismo , Epitelio Pigmentado de la Retina/metabolismo , Vasos Retinianos/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Secuencia de Aminoácidos , Animales , Apoptosis , Línea Celular , Proliferación Celular , Medios de Cultivo Condicionados/metabolismo , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatología , Retinopatía Diabética/patología , Retinopatía Diabética/fisiopatología , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Células Endoteliales/patología , Endotelio Vascular/patología , Endotelio Vascular/fisiopatología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Masculino , Datos de Secuencia Molecular , Estabilidad Proteica , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Epitelio Pigmentado de la Retina/fisiopatología , Vasos Retinianos/patología , Vasos Retinianos/fisiopatología , Factores de Tiempo , Transcripción Genética , Transfección
7.
Physiol Res ; 58(2): 203-209, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-18380531

RESUMEN

Diabetes mellitus is characterized by oxidative stress, which in turn determines endothelial dysfunction. Gliclazide is a sulphonylurea antidiabetic drug with antioxidant effects due to its azabicyclo-octyl ring. It has been reported to potentially protect the vasculature through improvements in plasma lipid levels and platelet function. We hypothesized that gliclazide has a beneficial effect on endothelial function in Goto-Kakizaki rats (GK), an animal model of type 2 diabetes fed an atherogenic diet for 4 months. We evaluated the influence of gliclazide on both metabolic and oxidative status and NO-mediated vasodilation. GKAD rats showed increased oxidative stress and impaired endothelium-dependent vasodilation. GKAD rats treated with gliclazide showed increased sensitivity to NO-mediated vasodilation, a significant decrease in fasting glycemia and insulinemia, and a significant decrease in systemic oxidative stress. In conclusion, our results suggest that gliclazide treatment improves NO-mediated vasodilation in diabetic GK rats with dyslipidemia probably due to its antioxidant effects, although we cannot rule out substantial benefits due to a reduction in fasting blood glucose. The availability of a compound that simultaneously decreases hyperglycemia, hyperinsulinemia, and inhibits oxidative stress is a promising therapeutic candidate for the prevention of vascular complications of diabetes.


Asunto(s)
Antioxidantes/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/prevención & control , Grasas de la Dieta/farmacología , Gliclazida/farmacología , Hipoglucemiantes/farmacología , 8-Hidroxi-2'-Desoxicoguanosina , Acetilcolina/farmacología , Animales , Peso Corporal , Desoxiguanosina/análogos & derivados , Desoxiguanosina/orina , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Angiopatías Diabéticas/metabolismo , Modelos Animales de Enfermedad , Dislipidemias/complicaciones , Dislipidemias/metabolismo , Óxido Nítrico/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Mutantes , Ratas Wistar , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología
8.
Biomed Pharmacother ; 113: 108728, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30856536

RESUMEN

Glioblastoma, which is highly invasive and has a poor patient prognosis, is the most common type of brain tumor. Flavonoids have known antiproliferative and antineoplastic effects, such as apoptosis induction and tumor growth inhibition. We investigated the effects of treatment with three flavonoids (BAS-1, BAS-4, and BAS-6) isolated from the Amazon plant Brosimum acutifolium on the proliferation and migration of the C6 glioma cell line. Cytotoxicity was evaluated by MTT assay, and morphological changes were evaluated by phase-contrast microscopy and by transmission electron microscopy. Apoptosis was determined using Annexin V-FITC-propidium iodide (PI) staining. A hemolysis assay was used to evaluate plasma membrane injury. Antiproliferative effects were assessed by wound migration and colony formation assays. Mitochondrial transmembrane potential (ΔΨm) was determined using JC-1 dye and flow cytometry. To identify the flavonoid targets, western blotting was performed. BAS-1 and BAS-4 reduced C6 cell proliferation in a dose-dependent manner. BAS-6 showed no effect. Due to its high toxicity toward primary glial cells and its high hemolytic index, BAS-1 was not used in the remaining experiments. BAS-4 treatment did not induce cytotoxicity in primary glial cells; however, in glioma cells, it suppressed migration and invasion and led to apoptosis through mitochondrial damage, ΔΨm loss, cell cycle arrest, and reduced AKT phosphorylation, which is a component of the main cell survival pathway. We conclude that BAS-4 showed potential activity against glioma by inducing apoptosis mediated by ΔΨm loss and AKT pathway disruption, and future studies should further evaluate BAS-4 as a promising antineoplastic agent against glioblastoma.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Flavonoides/farmacología , Glioma/tratamiento farmacológico , Moraceae/química , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias Encefálicas/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Flavonoides/administración & dosificación , Flavonoides/aislamiento & purificación , Citometría de Flujo , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Glioma/patología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar
9.
Br J Pharmacol ; 153(5): 894-906, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17906683

RESUMEN

BACKGROUND AND PURPOSE: This study was conducted to investigate the effects of alpha-lipoic acid (alpha-LA) on endothelial function in diabetic and high-fat fed animal models and elucidate the potential mechanism underlying the benefits of alpha-LA. EXPERIMENTAL APPROACH: Plasma metabolites reflecting glucose and lipid metabolism, endothelial function, urinary albumin excretion (UAE), plasma and aortic malondialdehyde (MDA) and urinary 8-hydroxydeoxyguanosine (8-OHdG) were assessed in non-diabetic controls (Wistar rats), untreated Goto-Kakizaki (GK) diabetic and high-fat fed GK rats (fed with atherogenic diet only, treated with alpha-LA and treated with vehicle, for 3 months). Vascular eNOS, nitrotyrosine, carbonyl groups and superoxide anion were also assessed in the different groups. KEY RESULTS: alpha-LA and soybean oil significantly reduced both total and non-HDL serum cholesterol and triglycerides induced by atherogenic diet. MDA, carbonyl groups, vascular superoxide and 8-OHdG levels were higher in GK and high-fat fed GK groups and fully reversed with alpha-LA treatment. High-fat fed GK diabetic rats showed significantly reduced endothelial function and increased UAE, effects ameliorated with alpha-LA. This endothelial dysfunction was associated with decreased NO production, decreased expression of eNOS and increased vascular superoxide production and nitrotyrosine expression. CONCLUSIONS AND IMPLICATIONS: alpha-LA restores endothelial function and significantly improves systemic and local oxidative stress in high-fat fed GK diabetic rats. Improved endothelial function due to alpha-LA was at least partially attributed to recoupling of eNOS and increased NO bioavailability and represents a pharmacological approach to prevent major complications associated with type 2 diabetes.


Asunto(s)
Antioxidantes/farmacología , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Endotelio Vascular/efectos de los fármacos , Ácido Tióctico/farmacología , Envejecimiento , Animales , Colesterol/sangre , Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Grasas de la Dieta , Endotelio Vascular/fisiopatología , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Aceite de Soja/química , Triglicéridos/sangre
10.
Diabetes Metab ; 33(4): 296-302, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17553720

RESUMEN

Plasma glucose, insulin and glucose tolerance were quantified in diabetic Goto-Kakizaki (GK) rats (342+/-45 g, n = 5) and compared with weight-matched non-diabetic Wistars (307+/-30 g, n = 8). Compared to Wistars, GK rats had higher fasting plasma insulin (219+/-50 versus 44+/-14 pmol/l, P<0.002) and glucose (9.2+/-2.3 versus 5.5+/-0.5 mmol/l, P<0.025). GK rats showed impaired glucose tolerance (IPGTT 2 h plasma glucose=14+/-1.5 versus 6.4+/-0.1 mmol/l, P<0.001). Endogenous glucose production (EGP) from glycogenolysis, phosphoenolpyruvate (PEP) and glycerol after 6 hours of fasting was quantified by a primed infusion of [U-(13)C]glucose and (2)H(2)O tracers and (2)H/(13)C NMR analysis of plasma glucose. EGP was higher in GK compared to Wistar rats (191+/-16 versus 104+/-27 mumol/kg per min, P<0.005). This was sustained by increased gluconeogenesis from PEP (85+/-12 versus 35+/-4 mumol/kg per min, P<0.02). Gluconeogenesis from glycerol was not different (20+/-3 in Wistar versus 30+/-6 mumol/kg per min for GK), and glycogenolysis fluxes were also not significantly different (76+/-23 mumol/kg per min for GK versus 52+/-19 mumol/kg per min for Wistar). The Cori cycle accounted for most of PEP gluconeogenesis in both Wistar and GK rats (85+/-15% and 77+/-10%, respectively). Therefore, increased gluconeogenesis in GK rats is largely sustained by increased Cori cycling while the maintenance of glycogenolysis indicates a failure in hepatic autoregulation of EGP.


Asunto(s)
Glucemia/metabolismo , Glucosa/metabolismo , Animales , Glicerol/metabolismo , Espectroscopía de Resonancia Magnética , Masculino , Ratas , Ratas Endogámicas , Ratas Wistar
11.
Acta Diabetol ; 44(3): 121-30, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17721750

RESUMEN

We investigated the effect of sub-chronic soybean oil (SO) treatment on the insulin secretion and fatty acid composition of islets of Langerhans obtained from Goto-Kakizaki (GK), a model of type 2 diabetes, and normal Wistar rats. We observed that soybean-treated Wistar rats present insulin resistance and defective islet insulin secretion when compared with untreated Wistar rats. The decrease in insulin secretion occurred at all concentrations of glucose and arginine tested. Furthermore we observed that soybean-treated normal islets present a significant decrease in two saturated fatty acids, myristic and heneicosanoic acids, and one monounsaturated eicosenoic acid, and the appearance of the monounsaturated erucic acid. Concerning diabetic animals, we observed that soybean-treated diabetic rats, when compared with untreated GK rats, present an increase in plasma non-fasting free fatty acids, an exacerbation of islet insulin secretion impairment in all conditions tested and a significant decrease in the monounsaturated palmitoleic acid. Altogether our results show that SO treatment results in a decrease of insulin secretion and alterations on fatty acid composition in normal and diabetic islets. Furthermore, the impairment of insulin secretion, islet erucic acid and fasting plasma insulin levels are similar in treated normal and untreated diabetic rats, suggesting that SO could have a deleterious effect on beta-cell function and insulin sensitivity.


Asunto(s)
Glucosa/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Aceite de Soja/farmacología , Animales , Arginina/farmacología , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatología , Modelos Animales de Enfermedad , Ácidos Grasos/metabolismo , Femenino , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Ácido Mirístico/metabolismo , Ratas , Ratas Endogámicas , Valores de Referencia
12.
Med Chem ; 2(3): 299-308, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16948477

RESUMEN

This study evaluated and compared the effect of insulin treatment on the status of brain, heart and kidney mitochondria isolated from 12-week streptozotocin (STZ)-induced diabetic rats versus STZ-diabetic animals treated with insulin during a period of 4 weeks. Mitochondria isolated from 12-week citrate (vehicle)-treated rats were used as control. Several mitochondrial parameters were evaluated: respiratory indexes (state 3 and 4 of respiration, respiratory control and ADP/O ratios), transmembrane potential, depolarization and repolarization levels, ATP, glutathione and coenzyme Q contents, production of hydrogen peroxide, superoxide dismutase, glutathione peroxidase and glutathione reductase activities and the ability of mitochondria to accumulate calcium. We observed that diabetes promoted a significant decrease in kidney and brain mitochondrial coenzyme Q9 content while this parameter was increased in heart mitochondria. Furthermore, diabetes induced a significant increase in hydrogen peroxide production in kidney mitochondria this effect being accompanied by a significant increase in glutathione peroxidase and reductase activities. Furthermore, brain mitochondria isolated from diabetic animals presented a lower ATP content and ability to accumulate calcium. In contrast, heart and kidney mitochondria presented a slight higher capacity to accumulate calcium. Insulin treatment normalized the levels of coenzyme Q9 and glutathione peroxidase and reductase activities and increased ATP content and the ability to accumulate calcium. Altogether these results suggest that insulin treatment attenuates diabetes-induced mitochondrial alterations protecting against the increase in oxidative stress and improving oxidative phosphorylation efficiency. In this line, insulin therapy, besides its well-known importance in the maintenance of glycemic control, may help to protect against mitochondrial dysfunction associated to several age-related disorders such as diabetes.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Insulina/uso terapéutico , Mitocondrias/fisiología , Animales , Peso Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatología , Calcio/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Insulina/farmacología , Masculino , Mitocondrias/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fosforilación , Ratas , Ratas Wistar , Estreptozocina
13.
FEBS Lett ; 359(2-3): 137-41, 1995 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-7867786

RESUMEN

We have investigated the effects of the phorbol ester 12-myristate 13-acetate (PMA) on depolarization-evoked Ca2+ influx and catecholamine secretion in bovine adrenal chromaffin cells. PMA (100 nM) strongly inhibited K(+)-evoked [Ca2+]i transients and Mn2+ quenching of fura-2 fluorescence. In contrast, 4 alpha-phorbol 12,13-didecanoate, a phorbol ester inactive on protein kinase C (PKC), had no effect. Maximal PMA-mediated inhibition occurred at 5-10 min incubations and were variable from cell to cell, ranging from 25 to 65% of controls. The [Ca2+]i transients evoked by the L-type Ca2+ channel activator Bay K 8644 were strongly inhibited by 100 nM PMA. PMA (0.1-10 microM) inhibited K(+)-evoked adrenaline and noradrenaline release by 23-44%. The data indicate that phorbol ester-mediated activation of PKC inhibits voltage-sensitive Ca2+ channels in chromaffin cells, leading to a prominent depression of depolarization-evoked catecholamine secretion.


Asunto(s)
Corteza Suprarrenal/efectos de los fármacos , Bloqueadores de los Canales de Calcio/farmacología , Catecolaminas/metabolismo , Proteína Quinasa C/metabolismo , Acetato de Tetradecanoilforbol/farmacología , Corteza Suprarrenal/enzimología , Corteza Suprarrenal/metabolismo , Animales , Calcio/metabolismo , Bovinos , Electrofisiología , Técnicas In Vitro , Manganeso/metabolismo
14.
FEBS Lett ; 492(1-2): 146-50, 2001 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-11248253

RESUMEN

Selective protein kinase C (PKC) activators and inhibitors were used to investigate the involvement of specific PKC isoforms in the modulation of voltage-sensitive Ca(2+) channels (VSCCs) in bovine adrenal chromaffin cells. Exposure to the phorbol ester phorbol-12,13-dibutyrate (PDBu) inhibited the Ca(2+) currents elicited by depolarizing voltage steps. This inhibition was occluded by the PKC-specific inhibitor Ro 31-8220 but remained unaffected by Gö 6976, a selective inhibitor of conventional PKC isoforms. PDBu treatment caused the translocation of PKC-alpha and -epsilon isoforms from cytosol to membranes. PKC-iota and -zeta showed no signs of translocation. It is concluded that VSCCs are specifically inhibited by the activation of PKC-epsilon in chromaffin cells. This may be relevant to the action of phospholipase-linked receptors involved in the control of Ca(2+) influx, both in catecholaminergic cells and other cell types.


Asunto(s)
Canales de Calcio/metabolismo , Células Cromafines/enzimología , Proteína Quinasa C/metabolismo , Glándulas Suprarrenales/enzimología , Animales , Canales de Calcio/efectos de los fármacos , Bovinos , Células Cromafines/efectos de los fármacos , Células Cromafines/metabolismo , Técnicas In Vitro , Ésteres del Forbol/farmacología , Isoformas de Proteínas/efectos de los fármacos , Isoformas de Proteínas/metabolismo
15.
Eur J Pharmacol ; 366(2-3): 281-92, 1999 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-10082210

RESUMEN

Phorbol esters reduce depolarization-evoked Ca2+ influx in adrenal chromaffin cells, suggesting that voltage-sensitive Ca2+ channels (VSCCs) are inhibited by protein kinase C-mediated phosphorylation. We now address the possibility that L- and P/Q-type Ca2+ channel subtypes might be differentially involved in phorbol ester action. In bovine chromaffin cells, short-term (10 min) incubations with phorbol 12-myristate 13-acetate (PMA) inhibited early high K+-evoked rises in cytosolic free Ca2+ concentration ([Ca2+]i) and the early component of the depolarization-evoked Mn2+ quenching of fura-2 fluorescence in a dose-dependent manner (IC50: 18 and 7 nM; maximal inhibitions: 45 and 48%, respectively). The protein kinase C inhibitor staurosporine (100 nM) reverted the inhibitory action of PMA. PMA (0.1-1 microM) inhibited the early and late phases of the ionomycin (2 microM)-evoked [Ca2+]i transients by 14-23%. Omega-agatoxin IVA, a blocker of P/Q-type Ca2+ channels, inhibited high K+-evoked [Ca2+]i rises in a dose-dependent fashion (IC50 = 50 nM). In contrast, 0.1 microM omega-conotoxin GVIA, a blocker of N-type channels, was without effect. A sizeable (< 45%) component of early Ca2+ influx persisted in the combined presence of omega-agatoxin IVA (100 nM) and nitrendipine (1 microM). Simultaneous exposure to omega-agatoxin IVA and PMA inhibited both the early [Ca2+]i transients and Mn2+ quenching to a much greater extent than each drug separately. Inhibition of the [Ca2+]i transients by nitrendipine and PMA did not significantly exceed that produced by PMA alone. It is concluded that phorbol ester-mediated activation of protein kinase C inhibits preferentially L-type VSCCs over P/Q type channels in adrenal chromaffin cells. However, the possibility cannot be ruled out that dihydropyridine-resistant, non-P/Q type channels might also be negatively regulated by protein kinase C. This may represent an important pathway for the specific control of VSCCs by protein kinase C-linked receptors, not only in paraneurones but presumably also in neurones and other excitable cells.


Asunto(s)
Calcio/metabolismo , Células Cromafines/metabolismo , Proteína Quinasa C/metabolismo , Animales , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Canales de Calcio/fisiología , Carcinógenos/farmacología , Bovinos , Células Cromafines/citología , Células Cromafines/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Fluorescencia , Fura-2 , Manganeso/farmacología , Nitrendipino/farmacología , Péptidos/farmacología , Potasio/farmacología , Proteína Quinasa C/efectos de los fármacos , Venenos de Araña/farmacología , Estaurosporina/farmacología , Acetato de Tetradecanoilforbol/farmacología , omega-Agatoxina IVA , omega-Conotoxina GVIA
16.
J Pharm Biomed Anal ; 15(4): 487-93, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8953492

RESUMEN

A new amoxicillin sodium impurity was detected by reversed-phase HPLC in commercial injectable preparations only when examined very soon after the drug was dissolved in the solvent vial (within about 10 min). The stability of this impurity was investigated by the degradation kinetic of its aqueous solutions. Ionspray mass spectrometry with flow-injection analysis and HPLC-MS methods were used to establish its nature. Some hypotheses concerning its chemical structure were formulated. The most likely assumption referred to the (5S,6R) amoxicillin piperazinedione diasteroisomer. The presence of the amoxicilloic acid methyl ester, an intermediate of the amoxicillin degradation process, was also hypothesized.


Asunto(s)
Amoxicilina/análisis , Contaminación de Medicamentos , Cromatografía Líquida de Alta Presión/métodos , Análisis de Inyección de Flujo , Espectrometría de Masas
17.
Int J Biol Macromol ; 20(3): 193-204, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9218168

RESUMEN

This work analyzed the thermal denaturation process of defatted bovine serum albumin (BSA). DSC measurements were performed on changing the pH, the ionic strength and the sodium dodecyl sulfate (SDS) concentration. These data have been compared with those previously obtained by us and other authors. The purpose of these measurements was to study the correlation between the three-dimensional organization of BSA native protein structure and its thermodynamic stability and to clarify the non-covalent interactions between the globular proteins and amphipathic molecules. These measurements have shown that the thermal denaturation is always irreversible regardless of pH, ionic strength and SDS concentration. The nature of the irreversible process superimposed on the protein unfolding is discussed. The strong stabilizing effect of NaCl on the BSA native structure has been found for the range 0-1.0 M. It is worth noting that the calorimetric curves, confined to the pH region studied, could not be represented by a two-state transition model; they were deconvoluted as the sum of two independent two-state transitions. These transitions were correlated to the domain structure of BSA. Sodium dodecyl sulfate has a net stabilizing effect up to a molar ratio of 10:1 (ligand to protein). In this range of concentrations the presence of SDS cause a biphasic profile of excess heat capacity. A simple thermodynamic model was developed in attempt to reproduce the experimental DSC profiles and collect information regarding the binding equilibrium of SDS.


Asunto(s)
Rastreo Diferencial de Calorimetría/métodos , Albúmina Sérica Bovina/química , Dodecil Sulfato de Sodio/farmacología , Sitios de Unión , Relación Dosis-Respuesta a Droga , Concentración de Iones de Hidrógeno , Modelos Químicos , Concentración Osmolar , Desnaturalización Proteica/efectos de los fármacos , Pliegue de Proteína , Albúmina Sérica Bovina/efectos de los fármacos , Albúmina Sérica Bovina/metabolismo , Dodecil Sulfato de Sodio/química , Tensoactivos/química , Tensoactivos/farmacología , Termodinámica
18.
Arch Latinoam Nutr ; 38(4): 865-82, 1988 Dec.
Artículo en Español | MEDLINE | ID: mdl-3154297

RESUMEN

The composition of shrimp by-catch fish from the Central-Western region of Venezuela at different periods of the year was studied, as well as mean size and weight of same, and the yields obtained during processing, until the edible portion (pulp) was reached. The pulp was also analyzed from the physical, chemical and microbiological (pH, basic volatile N, trimethylamine, thiobarbituric acid test, moisture, fat, protein, ashes content and mesophyll and psychrophilic counts) points of view. The purpose of these studies was to determine its quality and freshness, since said pulp was utilized for the preparation of a canned and sterilized bread spread. Results obtained indicated the pulp to have an acceptable freshness, a fact which reflected in a final product with adequate characteristics. The bread spread was also analyzed from the physical, chemical, microbiological and sensory viewpoints (objective analyses of color and texture, pH, rancidity and sterility tests, moisture, fat protein, ashes, carbohydrates, sodium chloride contents, and sensory evaluation). In addition, these analyses were repeated monthly during the three-month storage period at two temperatures. On the basis of the above-mentioned findings, it was possible to determine that the bread spread had adequate acceptability and stability during storage. Furthermore, raw material variations did not affect the final product characteristics, which resulted in a product with commercial potential.


Asunto(s)
Productos Pesqueros , Manipulación de Alimentos , Tecnología de Alimentos , Productos Pesqueros/análisis , Microbiología de Alimentos , Conservación de Alimentos , Alimentos Formulados , Calor
19.
Rev Lat Am Enfermagem ; 9(1): 27-38, 2001 Jan.
Artículo en Portugués | MEDLINE | ID: mdl-12041050

RESUMEN

Aiming at valuing the use of strategies such as teaching and learning methods, the relaxation technique and coping are described in a case study concerning a hospitalized HIV-positive person presenting the Acquired Immuno-Defficiency Syndrome (AIDS). The Conceptual Model proposed by Dorothéia Orem (OREM, 1985), Risner's proposal for the conduction of diagnostic thinking and the Nursing Diagnostic Unifying System proposed by NANDA (NANDA, 1996) were use as theoretical framework. Among the identified diagnoses, three were selected in order to exemplify the planning, implementation and process evaluation phases.


Asunto(s)
Infecciones por VIH/enfermería , Proceso de Enfermería , Humanos
20.
Boll Chim Farm ; 128(2): 65-70, 1989 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2775519

RESUMEN

The level of particulate contamination in water small volume injections available in Italy has been determined. The influence of the ampoule size, breaking system, manual method of ampoule opening and the type of instrument used for the determination have been evaluated. The distribution of the particles inside the batch of the sample was also studied.


Asunto(s)
Contaminación de Medicamentos , Embalaje de Medicamentos , Estudios de Evaluación como Asunto , Infusiones Parenterales , Tamaño de la Partícula
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