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1.
J Med Microbiol ; 73(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38591530

RESUMO

Sexually transmitted infections (STI) are a public health problem. Real-time PCR assays are the most sensitive test for screening and diagnosis of these infections. The aim of this study was to evaluate a new CT/NG/TV/MG Real-Time PCR (RT-PCR) kit (Vircell) for the detection of Chamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis for the diagnosis of sexual transmitted infections using the Allplex STI Essential Assay (Seegene) as the reference's method. A total of 497 samples from different anatomical sites (endocervical, urethral, rectal, pharyngeal and urine) were analysed from October 2022 to February 2023. A total of 108 (21.73 %) and 106 (21.33 %) positive samples were found for any of the assays used. The most commonly detected pathogen was N. gonorrhoeae (52 samples; 10.46 %), and the least commonly detected was T. vaginalis (three samples; 0.60 %). The anatomical site with the highest prevalence of micro-organisms was a non-urogenital site, the pharynx (26 positive samples; 5.23 %). Using the Allplex STI Essential Assay (Seegene) as the reference method, the diagnosis performance showed that the average specificity of CT/NG/TV/MG RT-PCR Kit (Vircell) was 99.84 % and the sensitivity was 99.53 %. The overall concordance was k=0.98 (CI95 %; 0.96-1). In conclusion, the CT/NG/TV/MG RT-PCR Kit (Vircell) assay shows a good sensitivity and specificity and constitutes a promising and additional alternative to routine procedures for distinct types of clinical specimen in diagnosis STI.


Assuntos
Infecções por Chlamydia , Gonorreia , Infecções por Mycoplasma , Mycoplasma genitalium , Infecções Sexualmente Transmissíveis , Trichomonas vaginalis , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Chlamydia trachomatis/genética , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Trichomonas vaginalis/genética , Neisseria gonorrhoeae/genética , Mycoplasma genitalium/genética , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/epidemiologia , Tomografia Computadorizada por Raios X , Infecções por Chlamydia/diagnóstico , Gonorreia/diagnóstico , Gonorreia/epidemiologia
2.
Rev Clin Esp (Barc) ; 217(8): 454-459, 2017 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28830616

RESUMO

OBJECTIVES: In recent years, various scientific societies and healthcare organisations have created recommendations aimed at decreasing the use of healthcare interventions that have shown no efficacy or effectiveness. The aim of this study was to assess the impact of an intervention on 12 do-not-do recommendations regarding the laboratory in 7 hospital centres. METHODS: Before-after study conducted in 7 hospital centres of Cordoba and Jaen during 2015 and 2016. Based on the recommendations of existing scientific societies, a consensus was reached on various actions regarding laboratory measurements. We analysed the number and cost of measuring 6 tumour markers (carcinoembryonic antigen, prostate-specific antigen, carbohydrate antigen [CA] 15.3, CA125, CA19.9 and alpha-fetoprotein), thyrotropin, T3, T4, glycated haemoglobin, urea, ferritin and antigliadin antibodies, before and after implementing the consensus. RESULTS: Compared with the previous year, there were 55,902 fewer laboratory measurements (-19%) in 2016, with an overall savings of €82,100. The reduction in the number of measurements occurred mainly in plasma urea (-50.3%) and in the tumour markers CA125 (-16%), CA19.9 (-11.6%) and CA15.3 (-10.5%). The most pronounced savings were achieved in the measurements of urea (-€21,002), thyroid hormones (-€12,716) and thyrotropin (-€7,638). CONCLUSIONS: The adoption and consensus of do-not-do recommendations among healthcare levels resulted in a significant reduction in unnecessary measurements.

3.
Colloids Surf B Biointerfaces ; 152: 199-213, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28110042

RESUMO

Compartmentalization is a key feature of biological cells which conduct their metabolic activity in individual steps isolated in distinct, separated compartments. The creation of architectures containing multiple compartments with a structure that resembles that of a biological cell has generated significant research attention and these assemblies are proposed as candidate materials for a range of biomedical applications. In this Review article, the recent successes of multicompartment architectures as carriers for the delivery of therapeutic cargo or the creation of micro- and nanoreactors that mimic metabolic activities, thus acting as artificial cells or organelles, are discussed. The developed technologies to assemble such complex architectures are outlined, the multicompartment carriers' properties which contribute to their performance in diverse applications are discussed, and their successful applications are highlighted. Finally, future directions and developments in the field are suggested.


Assuntos
Portadores de Fármacos , Células Artificiais , Nanoestruturas/química
4.
Cell Mol Biol (Noisy-le-grand) ; 56 Suppl: OL1434-41, 2010 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-21062577

RESUMO

As cholesterol, oxysterols, can insert the cell membrane and thereby modify the functions of membrane-bound proteins. The Na,K-ATPase is very sensitive to its lipid environment, seems to be involved in important endothelial functions as the regulation of nitric oxide (NO) release. The effects of 7-ketocholesterol , an oxysterol present in oxidized LDL, was investigated on Na,K-ATPase in isolated human endothelial cells. Cells were incubated 24h with lecithin-, cholesterol- or 7-ketocholesterol liposomes (6 µg/ml). K+-stimulated paranitrophenyl phosphatase activity, reflecting Na,K-ATPase activity, was evaluated as well as cell viability and lipoperoxidation. The expression of Na,K-ATPase subunits mRNAs and membrane fluidity were also investigated. As Na,K-ATPase and nitric oxide seem to be related, we determined the production of NO and the expression of endothelial NO synthase mRNAs. Na,K-ATPase activity was strongly decreased by 7-ketocholesterol. This decrease, not related to lipoperoxidation, was correlated with a decreased expression of the Na,K-ATPase α1-subunit messengers and with rigidity of plasma membranes. Cholesterol induced similar effects but was less potent than 7-ketocholesterol. Basal NO production and expression of endothelial NO synthase mRNAs were not modified by 7-ketocholesterol. Our new findings demonstrate that 7-ketocholesterol, used at non toxic doses, was very potent to disrupt the transport of ions by Na,K-ATPase and perturb membrane structure. These data demonstrate that 7-ketocholesterol induces endothelial dysfunction without cell death that may contribute to early events in atherosclerosis.


Assuntos
Células Endoteliais/enzimologia , Cetocolesteróis/farmacologia , Fluidez de Membrana/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Colesterol/farmacologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/citologia , Humanos , Lecitinas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , RNA Mensageiro/metabolismo , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo
5.
Cell Mol Biol (Noisy-le-grand) ; 54 Suppl: OL1032-42, 2008 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-18954552

RESUMO

Dietary antioxidants are frequently proposed as protective agents for the vascular endothelium during the onset of atherosclerosis. This protection may occur at two distinct levels. First, they prevent oxidative modification of atherogenic lipoproteins (LDL). Second, they can provide a cellular protection against oxidized LDL-mediated endothelium dysfunction, although this mechanism remains poorly considered in many instances. To gain insight into the mechanism underlying such cellular protection against oxidized LDL, we examined the impact of a popular traditional medicine, an extract from Ginkgo biloba with well-known antioxidant properties, on two endothelial cells properties: cell adhesion and ionic homeostasis. Cellular lipoperoxides levels were also measured as a marker of cellular oxidative stress. Human umbilical-vein endothelial cells were exposed to native (nat-) or oxidized (ox-) LDL, the latter prepared to be compatible with clinically observed levels of oxidation. Although nat-LDL had little effect, ox-LDL increased endothelial adhesive properties (35%, p<0.01) and lipoperoxidation (45%, p<0.01). Na,K-ATPase activity, a key regulator of ionic homeostasis, was significantly decreased after exposure to nat-LDL (30%, p<0.01) and dramatically depressed after exposure to ox-LDL (65%, p<0.001). The standardized preparation of Ginkgo biloba EGb-761 totally protected adhesive properties and endothelial lipoperoxide levels. Moreover, it limited the decrease in Na,K-ATPase activity induced by ox-LDL to levels similar to nat-LDL. This suggests that EGb-761 protects endothelial adhesive properties and helps prevent the disruption of ionic homeostasis. The EGb-761-mediated inhibition of ox-LDL-induced lipoperoxide levels in endothelial cells appears to be an important mechanism by which Ginkgo biloba extract protects endothelial properties.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Ginkgo biloba/química , Lipoproteínas LDL/farmacologia , Extratos Vegetais/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular , Células Endoteliais/citologia , Células Endoteliais/fisiologia , Endotélio Vascular/citologia , Homeostase , Humanos , Peroxidação de Lipídeos , ATPase Trocadora de Sódio-Potássio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
6.
Cell Mol Biol (Noisy-le-grand) ; 50(7): 809-14, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15672465

RESUMO

The prostate gland is unique in its ability to secrete large amounts of zinc and citrate, suggesting that it employs unusual transport mechanisms. Intracellular ionic homeostasis in prostate is likely to be mediated by the Na,K-pump, yet there have been few studies of its regulation in this tissue. Accordingly, we explored the expression of the Na,K-pump in PC3 cells, an established cell line of human prostate epithelial cells. Total RNA from confluent monolayers of PC3 cells was isolated, reverse transcribed, and the resulting complementary DNA was amplified by polymerase chain reaction using primers specific for each of the pump's constituent subunits. The amplification revealed a complex pattern of Na,K-pump expression, with detection of mRNAs encoding the alpha1-, alpha3-, alpha4-, betal-, beta2- and beta3-isoforms. We next examined the effect on pump activity of prolactin, an important mediator of cell proliferation in prostate cancer. Monolayers exposed to 10 nM prolactin for 24 hr revealed an inhibition of 40% in ouabain-sensitive 86Rb+ uptake, a sensitive measure of pump-mediated transport. These experiments suggest that the unique transport properties of prostate may depend, at least in part, on a complicated pattern of Na,K-pump expression and regulation.


Assuntos
Prolactina/farmacologia , Neoplasias da Próstata/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Adenocarcinoma/patologia , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Epiteliais/enzimologia , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Ouabaína/farmacologia , Neoplasias da Próstata/patologia , RNA Mensageiro/genética , Radioisótopos/farmacocinética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rubídio/farmacocinética , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/genética , Fatores de Tempo
7.
Cell Mol Biol (Noisy-le-grand) ; 50(7): 869-74, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15672472

RESUMO

Hypertension and diabetes are commonly associated and strongly predispose to renal injuries. In general, antihypertensive therapies protect from these damages, but the effect of cicletanine, a new type of antihypertensive drug, is unknown. This study examines the effects of cicletanine on renal failure in spontaneously hypertensive rats with diabetes (SHRD). Diabetes mellitus was induced with streptozotocin in uninephrectomized SHR. Rats received the vehicle, 10 mg or 50 mg/kg per day of cicletanine for 6 weeks. Age-matched untreated Wistar-Kyoto rats were used as controls. Systolic blood pressure (SBP), microalbuminuria and proteinuria were assessed throughout the treatment. At the end of the study, creatinine clearance measurements and histological analysis of kidneys were performed. Cicletanine did not affect SBP but decreased the elevated albuminuria of diabetic SHR in a dose-dependent manner. Similar results were obtained for proteinuria. Treatment with the high dose of cicletanine also normalized the altered creatinine clearance of diabetic SHR. These results indicate that cicletanine has a renal-protective action, probably blood pressure-independent, in a model combining hypertension and diabetes. The mechanism of renal-protection of cicletanine is not clearly established but may be due to the stimulation of arterial prostacyclin synthesis and/or to the reduction of intraglomerular capillary pressure.


Assuntos
Anti-Hipertensivos/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Rim/efeitos dos fármacos , Substâncias Protetoras/uso terapêutico , Piridinas/farmacologia , Albuminúria/tratamento farmacológico , Animais , Pressão Sanguínea , Peso Corporal/efeitos dos fármacos , Creatinina/sangue , Creatinina/urina , Diabetes Mellitus Experimental/fisiopatologia , Relação Dose-Resposta a Droga , Rim/patologia , Masculino , Nefrectomia , Proteinúria , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
9.
Cell Mol Biol (Noisy-le-grand) ; 47(2): 313-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11355006

RESUMO

Fatty acids are known as modulators of the vasoactive properties of the vessel wall and can influence the physical and functional properties of cell membrane. The membrane-bound enzyme Na,K-ATPase plays a central role in endothelial function such as vasoconstriction. In a previous study, we have shown that omega3 fatty acids inhibited Na,K-ATPase activity in human endothelial cells. As Mediterranean diet is known to protect from cardiovascular diseases, we have investigated the effects of Omegacoeur, a Mediterranean nutritional complement consisting of omega3, omega6, omega9 fatty acids, garlic and basil, on Na,K-ATPase activity in human endothelial cells (HUVECs). Cells were incubated for 18 hr with pure lecithin liposomes or Omegacoeur-enriched emulsions (4 mg lecithin/ml). Na,K-ATPase and 5'-nucleotidase activities were determined using coupled assay methods on microsomal fractions obtained from HUVECs. Cell fatty acid composition was evaluated by gas chromatography after extraction of lipids and fatty acids methylation. The results showed that Omegacoeur (0.1 mM) increased Na,K-ATPase activity by 40% without changes in 5'-nucleotidase activity. Cells incubated with Omegacoeur preferentially incorporated linoleic acid. Therefore, linoleic acid or others constituents of Omegacoeur could be responsible of the stimulation of the Na,K-ATPase activity that might be related to changes in endothelial membrane fluidity.


Assuntos
Suplementos Nutricionais , Endotélio Vascular/enzimologia , Ácidos Graxos/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , 5'-Nucleotidase/metabolismo , Fracionamento Celular , Células Cultivadas , Meios de Cultura Livres de Soro , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Humanos , Lipossomos/química , Lipossomos/metabolismo , Região do Mediterrâneo , Microssomos/química , Microssomos/metabolismo , Fosfatidilcolinas/química , Fosfatidilcolinas/farmacologia
10.
Int J Cardiol ; 78(1): 27-32, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11259810

RESUMO

A low frequency of ischaemic heart diseases in Eskimos has been related to polyunsaturated fatty acids. We therefore studied fatty acid patterns associated with coronary artery disease (CAD) for a possible relationship between fatty acid profile and CAD diagnosis in Mediterranean patients. The gas chromatography method was used to analyze the membranes of patients' erythrocytes. The patients without coronary stenosis were used as controls. Patients with CAD showed increased percentages of saturated fatty acids (35.8 vs. 34.2%, P<0.001) and monounsaturated fatty acids (14.6 vs. 13.6%, P<0.01), as well as reduced percentages of polyunsaturated fatty acids (38.5 vs. 41.3%, P<0.001). The decrease in polyunsaturated fatty acids percentages was due to the series of n-3 fatty acids (9.2 vs. 11.4%, P<0.001), mainly at the expense of docosahexaenoic acid [C22:6 (n-3)] (4.9+/-0.25% vs. 6.4+/-0.23%, P<0.001) and docosapentaenoic acid [C22:5 (n-3)] (3.0+/-0.19% vs. 3.9+/-0.12%, P<0.001). The study shows altered n-3 fatty acids in Mediterranean patients with CAD. Our data suggest that the percentage of docosahexaenoic and docosapentaenoic acids in erythrocytes could be used as indicators of an independent risk factor for coronary artery disease.


Assuntos
Doença das Coronárias/sangue , Membrana Eritrocítica/química , Ácidos Graxos/análise , Adulto , Idoso , Ácidos Graxos Ômega-3/análise , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade
11.
J Cardiovasc Electrophysiol ; 11(4): 432-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10809497

RESUMO

INTRODUCTION: Ventricular fibrillation induced by either digitalis intoxication or electrical stimulation is reported to alter myocardial energy by impairing the sarcolemmal Na,K-ATPase or the receptor for digitalis and the mitochondrial ATPase synthase or F0F1-ATPase. However, little is known about these membrane functions during atrial fibrillation (AF). METHODS AND RESULTS: We analyzed the effects of electrically induced AF on biochemical activities of atrial F0F1-ATPase and Na,K-ATPase in sheep. A group of six sheep was subjected to direct short electrical stimulation of the right atrium to induce AF. Sham-operated sheep served as a control group. Microsomal and mitochondrial membranes of atrial muscle were isolated and tested for enzymatic activity. All paced sheep developed multiple episodes of sustained AF, with a mean total duration of 110 minutes over a 2-hour period. Data showed that short-term pacing-induced AF significantly activated membrane F0F1-ATPase activity (P < 0.05) without changes in cytochrome-c oxidase activity, Na,K-ATPase activity, ouabain sensitivity, and alpha1-subunit expression. CONCLUSION: Specific activation of F0F1-ATPase activity is an early molecular consequence of sustained AF in sheep.


Assuntos
Fibrilação Atrial/enzimologia , Átrios do Coração/enzimologia , Mitocôndrias Cardíacas/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Regulação para Cima , Animais , Fibrilação Atrial/etiologia , Biomarcadores , Western Blotting , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Estimulação Elétrica/efeitos adversos , Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Ouabaína , ATPases Translocadoras de Prótons/antagonistas & inibidores , Ovinos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo
12.
J Cardiovasc Electrophysiol ; 11(4): 439-45, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10809498

RESUMO

INTRODUCTION: Electrical external cardioversion commonly used to treat atrial fibrillation (AF) is associated with myocardial membrane damage and disturbances in ionic homeostasis (hemodynamically unstable). The present study was designed to investigate whether alterations in ionic homeostasis observed were due in part to changes in the myocardial activity of Na,K-ATPase. METHODS AND RESULTS: AF was induced by pacing in ten anesthetized sheep divided into two groups. Group I (n = 4) received a single external countershock of 360 J after three episodes of AF lasting 10 minutes. Group II (n = 6) served as controls. Activity, responsiveness to ouabain, and membrane expression of catalytic alpha and beta subunits of Na,K-ATPase in sarcolemmal myocardial membrane fractions were investigated. Membrane fluidity and fatty acid composition, and plasma levels of atrial natriuretic factor (ANF) also were measured. One shock after episodes of AF significantly decreased ventricular Na,K-ATPase activity up to 50% (P < 0.001) without modification of atrial activity at the membrane level. Sites with low affinity to ouabain showed a fivefold lower affinity for ouabain in the cardioversion group than in the control group (IC50 = 7.9 micromol/L vs 40 micromol/L ouabain, P < 0.05). Plasma levels of ANF were significantly increased in the cardioversion group compared with the control group. These changes were independent of membrane modulation in terms of expression of Na,K-ATPase, membrane fluidity, and fatty acid composition. CONCLUSION: This study suggests that left ventricular perturbation of ionic homeostasis subsequent to transthoracic cardioversion could result from inactivation of Na,K-ATPase activity.


Assuntos
Fibrilação Atrial/terapia , Cardioversão Elétrica , Miocárdio/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Fibrilação Atrial/etiologia , Fibrilação Atrial/metabolismo , Fator Natriurético Atrial/sangue , Biomarcadores , Western Blotting , Estimulação Cardíaca Artificial/efeitos adversos , Modelos Animais de Doenças , Cardioversão Elétrica/métodos , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos , Ácidos Graxos/metabolismo , Transporte de Íons/fisiologia , Fluidez de Membrana , Microssomos/enzimologia , Ouabaína , Sarcolema/enzimologia , Ovinos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
13.
Can J Vet Res ; 64(2): 88-95, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10805246

RESUMO

Actinobacillus pleuropneumoniae causes pleuropneumonia in swine. This bacterium secretes proteases that degrade porcine hemoglobin and IgA in vitro. To further characterize A. pleuropneumoniae proteases, we constructed a genomic library expressed in Escherichia coli DH5alpha, and selected a clone that showed proteolytic activity. The recombinant plasmid carries an 800-base pair A. pleuropneumoniae gene sequence that.codes for a 24-kDa polypeptide. A 350-base pair PstI fragment from the sequence hybridized at high stringency with DNA from 12 serotypes of A. pleuropneumoniae, but not with DNA from Actinobacillus suis, Haemophilus parasuis, Pasteurella haemolytica, Pasteurella multocida A or D, or E. coli DH5alpha, thus showing specificity for A. pleuropneumoniae. The expressed polypeptide was recognized as an antigen by convalescent-phase pig sera. Furthermore, a polyclonal antiserum developed against the purified polypeptide recognized an A. pleuropneumoniae oligomeric protein in both crude-extract and cell-free culture media. This recombinant polypeptide cleaved azocoll, gelatin, and actin. Inhibition of the proteolytic activity by diethylpyrocarbonate suggests that this polypeptide is a zinc metalloprotease.


Assuntos
Infecções por Actinobacillus/patologia , Actinobacillus pleuropneumoniae/enzimologia , Metaloendopeptidases/metabolismo , Doenças dos Suínos/microbiologia , Actinobacillus pleuropneumoniae/classificação , Actinobacillus pleuropneumoniae/genética , Actinas/metabolismo , Animais , Clonagem Molecular , DNA Bacteriano , Biblioteca Gênica , Metaloendopeptidases/genética , Metaloendopeptidases/isolamento & purificação , Plasmídeos , Sorotipagem , Suínos , Zinco
14.
Eur J Biochem ; 267(7): 2071-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10727947

RESUMO

Na+/K+-ATPase during diabetes may be regulated by synthesis of its alpha and beta subunits and by changes in membrane fluidity and lipid composition. As these mechanisms were unknown in liver, we studied in rats the effect of streptozotocin-induced diabetes on liver Na+/K+-ATPase. We then evaluated whether fish oil treatment prevented the diabetes-induced changes. Diabetes mellitus induced an increased Na+/K+-ATPase activity and an enhanced expression of the beta1 subunit; there was no change in the amount of the alpha1 and beta3 isoenzymes. Biphasic ouabain inhibition curves were obtained for diabetic groups indicating the presence of low and high affinity sites. No alpha2 and alpha3 isoenzymes could be detected. Diabetes mellitus led to a decrease in membrane fluidity and a change in membrane lipid composition. The diabetes-induced changes are not prevented by fish oil treatment. The results suggest that the increase of Na+/K+-ATPase activity can be associated with the enhanced expression of the beta1 subunit in the diabetic state, but cannot be attributed to changes in membrane fluidity as typically this enzyme will increase in response to an enhancement of membrane fluidity. The presence of a high-affinity site for ouabain (IC50 = 10-7 M) could be explained by the presence of (alphabeta)2 diprotomeric structure of Na+/K+-ATPase or an as yet unknown alpha subunit isoform that may exist in diabetes mellitus. These stimulations might be related, in part, to the modification of fatty acid content during diabetes.


Assuntos
Diabetes Mellitus Experimental/enzimologia , Isoenzimas/metabolismo , Fígado/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Sequência de Bases , Glicemia/análise , Peso Corporal , Primers do DNA , Diabetes Mellitus Experimental/sangue , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/metabolismo , Isoenzimas/antagonistas & inibidores , Fígado/metabolismo , Masculino , Lipídeos de Membrana/metabolismo , Ouabaína/farmacologia , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Estreptozocina
15.
J Histochem Cytochem ; 47(6): 809-16, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10330457

RESUMO

Because diabetes causes alterations in hepatic membrane fatty acid content, these changes may affect the Na+,K+-ATPase. In this study we documented the effects of streptozotocin (STZ)-induced diabetes on hepatic Na+,K+-ATPase catalytic alpha1-subunit and evaluated whether these changes could be normalized by fish oil supplementation. Two groups of diabetic rats received fish oil or olive oil supplementation. Both groups had a respective control group. We studied the localization of catalytic alpha1-subunit on bile canalicular and basolateral membranes using immunocytochemical methods and confocal laser scanning microscopy, and the Na+, K+-ATPase activity, membrane fluidity, and fatty acid composition on isolated hepatic membranes. A decrease in the alpha1-subunit was observed with diabetes in the bile canalicular membranes, without changes in basolateral membranes. This decrease was partially prevented by dietary fish oil. Diabetes induces significant changes as documented by enzymatic Na+,K+-ATPase activity, membrane fluidity, and fatty acid content, whereas little change in these parameters was observed after a fish oil diet. In conclusion, STZ-induced diabetes appears to modify bile canalicular membrane integrity and dietary fish oil partly prevents the diabetes-induced alterations.


Assuntos
Diabetes Mellitus Experimental/enzimologia , Óleos de Peixe/uso terapêutico , Fígado/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Membrana Celular/química , Membrana Celular/enzimologia , Membrana Celular/fisiologia , Diabetes Mellitus Experimental/dietoterapia , Ácidos Graxos/análise , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Masculino , Ratos , Ratos Sprague-Dawley
16.
Atherosclerosis ; 142(2): 327-33, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10030384

RESUMO

We have investigated the effects of cholesterol and omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexenoic acid (DHA) on Na, K-ATPase activity in human endothelial cells (HUVEC). Cultured HUVEC were incubated for 18 h with pure egg phosphatidylcholine (PC), or cholesterol-enriched liposomes (4 mg PC/ml). EPA and DHA alpha-tocopherol-acetate were emulsified with PC and incubated with HUVEC (10 mM). Na, K-ATPase and 5'-nucleotidase activities were determined using the coupled assay method on microsomal fractions obtained from cultured cells using non treated cells as control. Cholesterol enrichment significantly reduced both Na, K-ATPase and 5'-nucleotidase activities by a similar level (- 40%), whereas pure phospholipid liposomes inhibited this activity only by 22%. The dose-response curves of Na, K-ATPase activity were all biphasic assuming the presence of two independent sites exhibiting different affinities for ouabain of nM and microM respectively. The cholesterol induced inhibitory effect was greater for low affinity sites (-54%) as compared to that of the high affinity sites (-24%) whereas omega-3 fatty acids reduced the activity of both sites by 22%. Short term effects of EPA and DHA on Na, K-ATPase activity were determined by incubating microsomal fractions from untreated cells with various concentrations of free fatty acids (from 1 to 200 microM) for 20 min. Both EPA and DHA significantly reduced Na, K-ATPase activity but inhibition by EPA seems to be more effective than DHA. These results suggest that cholesterol and omega-3 fatty acids reduce Na, K-ATPase activity in HUVEC.


Assuntos
Colesterol/farmacologia , Endotélio Vascular/enzimologia , Ácidos Graxos Ômega-3/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Membrana Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Membrana Celular/ultraestrutura , Células Cultivadas , Ácidos Docosa-Hexaenoicos/farmacologia , Relação Dose-Resposta a Droga , Ácido Eicosapentaenoico/farmacologia , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Microssomos/ultraestrutura , Ouabaína/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Ultracentrifugação , Veias Umbilicais/citologia , Veias Umbilicais/efeitos dos fármacos , Veias Umbilicais/enzimologia
17.
Rev Enferm ; 21(237): 65-9, 1998 May.
Artigo em Espanhol | MEDLINE | ID: mdl-9653340

RESUMO

The nursing personnel at the C.H. Xeral-Cíes participated in a study of various types of self-protection methods over two time spans. The hypotheses investigated were the following: 1. Is there a divergence in the percentage of personnel vaccinated against hepatitis B?, 2. Is there an increase in the level of knowledge about universal precautions?, and 3. Is there any improvement in self-protection methods in the latter study? The statistical analysis used has a variable range of < 0.05. The results indicated significant differences in the percentage of personnel vaccinated against hepatitis B, in knowledge about universal precautions, and in the number of accidental punctures reported to the Preventative Medicine Service.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Controle de Infecções/métodos , Recursos Humanos de Enfermagem/educação , Recursos Humanos de Enfermagem/psicologia , Saúde Ocupacional , Autocuidado , Autocuidado/métodos , Estudos Transversais , Humanos , Ferimentos Penetrantes Produzidos por Agulha/prevenção & controle , Autocuidado/psicologia , Inquéritos e Questionários , Precauções Universais , Vacinação
18.
Am J Med ; 76(1): 151-4, 1984 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6691353

RESUMO

A 24-year-old woman presented with clinical features suggesting hypoparathyroidism: tetany, basal ganglia calcification, and a history of a seizure disorder. Hypocalcemia was present on admission despite therapy with calcium and vitamin D. Hormonal evaluation revealed undetectable parathormone levels and a normal cyclic AMP and phosphaturic response to parathormone infusion, suggesting the diagnosis of idiopathic hypoparathyroidism. Additional testing, however, revealed hypomagnesemia and elevated urinary magnesium levels. Normomagnesemia could not be consistently achieved despite oral magnesium administration. When the serum magnesium level was temporarily normalized via intravenous magnesium supplementation, parathormone levels rose into the normal range. These data indicate that the patient's hypomagnesemia was most likely due to renal magnesium loss. The normalization of her parathormone level during magnesium replenishment, along with the parathormone infusion data, suggests that this patient's hypomagnesemia was responsible for decreased parathormone synthesis and/or secretion, while target tissue responsiveness to parathormone was maintained.


Assuntos
Hipoparatireoidismo/etiologia , Nefropatias/fisiopatologia , Magnésio/sangue , Hormônio Paratireóideo/metabolismo , Adulto , Cálcio/sangue , Feminino , Humanos , Hipocalcemia/etiologia , Hipoparatireoidismo/fisiopatologia , Deficiência de Magnésio/complicações , Hormônio Paratireóideo/sangue
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