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2.
Hellenic J Cardiol ; 61(3): 174-177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30639355

RESUMO

BACKGROUND: This study assessed the diagnostic reliability of automated office blood pressure (OBP) measurements in treated hypertensive patients in primary care by evaluating the prevalence of white coat hypertension (WCH) and masked uncontrolled hypertension (MUCH) phenomena. METHODS: Primary care physicians, nationwide in Greece, assessed consecutive hypertensive patients on stable treatment using OBP (1 visit, triplicate measurements) and home blood pressure (HBP) measurements (7 days, duplicate morning and evening measurements). All measurements were performed using validated automated devices with bluetooth capacity (Omron M7 Intelli-IT). Uncontrolled OBP was defined as ≥140/90 mmHg, and uncontrolled HBP was defined as ≥135/85 mmHg. RESULTS: A total of 790 patients recruited by 135 doctors were analyzed (age: 64.5 ± 14.4 years, diabetics: 21.4%, smokers: 20.6%, and average number of antihypertensive drugs: 1.6 ± 0.8). OBP (137.5 ± 9.4/84.3 ± 7.7 mmHg, systolic/diastolic) was higher than HBP (130.6 ± 11.2/79.9 ± 8 mmHg; difference 6.9 ± 11.6/4.4 ± 7.6 mmHg, p < 0.001). WCH phenomenon (high OBP with low HBP) was observed in 22.7% of the patients, MUCH (low OBP with high HBP) in 15.8%, uncontrolled hypertension (high OBP with high HBP) in 29.9%, and controlled hypertension (low OBP with low HBP) in 31.6%. In multivariate logistic regression analysis, WCH was determined by stage-1 systolic hypertension (odds ratio [OR] 8.6, 95% confidence intervals [CI] 5.7, 13.1) and female gender (OR 1.6, 95% CI 1.1, 2.4), whereas MUCH was determined by high-normal systolic OBP (OR 6.2, 95% CI 3.8, 10.1) and male gender (OR 2.0, 95% CI 1.2, 3.1). CONCLUSIONS: In primary care, automated OBP measurements are misleading in approximately 40% of treated hypertensive patients. HBP monitoring is mandatory to avoid overtreatment of subjects with WCH phenomenon and prevent undertreatment and subsequent excess cardiovascular disease in MUCH.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Hipertensão , Pressão Sanguínea , Determinação da Pressão Arterial , Feminino , Grécia/epidemiologia , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde , Reprodutibilidade dos Testes
3.
J Hum Hypertens ; 28(2): 98-104, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23863803

RESUMO

Preeclampsia is associated with a number of changes to maternal vascular function. Assessment of arterial stiffness using pulse wave analysis (PWA) has been proposed as a means of predicting preeclampsia before the onset of clinically detectable disease. One hundred and eighty women with 2 risk factors for preeclampsia were examined at gestational weeks 16 and 28, of whom 17 (9.4%) developed preeclampsia. To study the effects of pregnancy itself women were also examined at 6-9 months post-natally; an additional 30 healthy non-pregnant women were also examined. PWA was performed using SphygmoCor; augmentation index (AIx), a marker of arterial wave reflection, was also measured using EndoPAT-2000. Women who developed preeclampsia were more likely to be overweight and had a higher brachial and central diastolic BP at gestational week 16 than those who remained normotensive. There was no difference in any parameter of arterial wave reflection between non-pregnant and pregnant women, nor between those who developed preeclampsia and those who remained normotensive, when examined at weeks 16 and 28 or post-natally. In this cohort of women with risk factors for preeclampsia, PWA did not provide additional information beyond brachial blood pressure and maternal risk factor profile about the risk of future development of preeclampsia.


Assuntos
Pré-Eclâmpsia/diagnóstico , Análise de Onda de Pulso , Rigidez Vascular , Adulto , Pressão Arterial , Artéria Braquial/fisiopatologia , Feminino , Idade Gestacional , Humanos , Estudos Longitudinais , Pré-Eclâmpsia/etiologia , Pré-Eclâmpsia/fisiopatologia , Valor Preditivo dos Testes , Gravidez , Medição de Risco , Fatores de Risco , Adulto Jovem
4.
BJOG ; 119(13): 1564-71, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23121125

RESUMO

OBJECTIVE: To study gene expression profiles in human endothelial cells incubated with plasma from women who developed pre-eclampsia and women with normotensive pregnancies. DESIGN: A case-control study. SETTING: A longitudinal nested case-control study within three maternity units. POPULATION: A mixed obstetric population attending maternity hospitals in Glasgow. METHODS: Plasma was obtained at both 16 and 28 weeks of gestation from 12 women: six women subsequently developed pre-eclampsia (cases) and six women, matched for age, body mass index (BMI) and parity, remained normotensive (controls). Human umbilical vein endothelial cells (HUVECs) were incubated with plasma for 24 hour before RNA isolation. MAIN OUTCOME MEASURES: Gene expression profiles were compared between the two gestational time points using Illumina(®) HumanHT-12 v4 Expression BeadChips. Differential mRNA expression observed in microarray experiments were validated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), and gene networks were analysed using Ingenuity(®) pathway analysis. RESULTS: There was a significant difference in the expression of 25 genes following incubation with plasma from controls, and an increase in the expression of 11 genes following incubation with plasma from cases, with no overlap between the two groups (false discovery rate, FDR < 0.05). There was a 3.74-fold (FDR < 0.001) increase in the expression of the c-Fos gene (FOS) when HUVECs were incubated with control plasma from 16 and 28 weeks of gestation, with no significant difference between the two time points with plasma from cases. Similar findings for FOS were obtained by qRT-PCR. CONCLUSIONS: Plasma from women who subsequently develop pre-eclampsia appears to contain factors that lead to the dysregulation of FOS in endothelial cells during pregnancy. Reduced expression of c-Fos may lead to impaired vasculogenesis, and thereby contribute to the development of pre-eclampsia.


Assuntos
Regulação da Expressão Gênica , Genes fos , Células Endoteliais da Veia Umbilical Humana , Pré-Eclâmpsia/genética , Transcriptoma , Estudos de Casos e Controles , Células Cultivadas , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Marcadores Genéticos , Humanos , Estudos Longitudinais , Análise de Sequência com Séries de Oligonucleotídeos , Plasma , Pré-Eclâmpsia/sangue , Gravidez , Segundo Trimestre da Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Eur J Pain ; 16(7): 1053-63, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22337623

RESUMO

Chronic pain is pathological, persisting beyond normal tissue healing time. Previous work has suggested ∼50% variation in chronic pain development is heritable. No data are currently available on the heritability of pain categorized using the Chronic Pain Grade (CPG). Furthermore, few existing studies have accounted for potential confounders that may themselves be under genetic control or indeed 'heritable' non-genetic traits. This study aimed to determine the relative contributions of genetic, measured and shared environmental and lifestyle factors to chronic pain. Chronic pain status was determined and CPG measured in participants from Generation Scotland: the Scottish Family Health Study, a large cohort of well-characterized, extended families from throughout Scotland, UK. Heritability estimates (h (2) ) for 'any chronic pain' and 'severe' chronic pain (CPG 3 or 4) were generated using SOLAR software, with and without adjustment for shared household effects and measured covariates age, body mass index, gender, household income, occupation and physical activity. Data were available for 7644 individuals in 2195 extended families. Without adjustment, h (2) for 'any chronic pain' was 29% [standard errors (SE) 6%; p < 0.001], and for 'severe' chronic pain was 44% (SE 3%; p <0.001). After adjustment, 'any chronic pain' h(2) = 16% (SE 7%; p = 0.02) and 'severe' chronic pain h(2) = 30% (SE 13%; p = 0.007). Co-heritability of both traits was 11% (SE 76%). This study supports the use of chronic pain as a phenotype in genetic studies, with adequate correction for confounders to specifically identify genetic risk factors for chronic pain.


Assuntos
Dor Crônica/genética , Característica Quantitativa Herdável , População Branca/genética , Adulto , Dor Crônica/diagnóstico , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Fenótipo , Índice de Gravidade de Doença
6.
Neuropathol Appl Neurobiol ; 37(7): 711-26, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21392049

RESUMO

AIMS: The spontaneously hypertensive stroke-prone rat (SHRSP) is a potential animal model of human lacunar stroke, but there is little information on SHRSP small vessel pathology, especially in young rats. We investigated the structural changes that occur in cortical and subcortical vessels and adjacent tissue in SHRSP before, during and after the onset of hypertension. METHODS: We examined brains from SHRSP and Wistar Kyoto rats (WKY) at 5, 16 and 21 weeks of age. Structural changes in small arterioles and adjacent tissue were studied using antibodies to investigate different components of the neurovascular unit. We quantified staining in three standard regions, at two coronal levels. RESULTS: Immunostaining for claudin-5, a marker of endothelial tight junctions, was reduced in SHRSP at all ages compared to age-matched WKY controls. Smooth muscle actin, glial fibrillary acidic protein and ionized calcium-binding adaptor molecule 1 were increased in SHRSP vs. WKY by 16 weeks. Additionally, 21-week-old WKY and SHRSP rats fed a high-salt diet showed differences in claudin-5, glial fibrillary acidic protein and matrix metalloproteinase 9 staining compared to those fed a normal diet. CONCLUSION: Endothelial tight junction alterations of SHRSP rats from the earliest ages point towards increased susceptibility to blood-brain barrier dysfunction and stroke, which is exacerbated by salt loading. Salt loading may also damage the neurovascular unit in WKY controls.


Assuntos
Encéfalo/patologia , Doenças de Pequenos Vasos Cerebrais/patologia , Endotélio Vascular/patologia , Hipertensão/patologia , Acidente Vascular Cerebral/patologia , Animais , Barreira Hematoencefálica/patologia , Barreira Hematoencefálica/fisiopatologia , Encéfalo/irrigação sanguínea , Doenças de Pequenos Vasos Cerebrais/fisiopatologia , Progressão da Doença , Endotélio Vascular/fisiopatologia , Hipertensão/fisiopatologia , Imuno-Histoquímica , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Cloreto de Sódio na Dieta , Acidente Vascular Cerebral/fisiopatologia
8.
Clin Endocrinol (Oxf) ; 67(6): 832-8, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17651452

RESUMO

BACKGROUND: Aldosterone is an important cardiovascular hormone; 15% of hypertensive subjects have alteration in aldosterone regulation, defined by a raised ratio of aldosterone to renin (ARR). Studies of the aldosterone synthase gene (CYP11B2) have focused on a single nucleotide polymorphism in the 5'promoter region (-344 C/T). In normotensive subjects, the T allele associates with raised levels of the 11-deoxysteroids, deoxycorticosterone and 11-deoxycortisol which are substrates for 11beta-hydroxylase, encoded by the adjacent and homologous gene, CYP11B1. We have speculated that this altered 11beta-hydroxylase efficiency leads to increased ACTH drive to the adrenal gland to maintain cortisol production and reported herein the association between the -344 C/T single nucleotide polymorphism (SNP) and adrenal steroid production in subjects with essential hypertension. METHODS: The CYP11B2-344 C/T polymorphism was genotyped and urinary excretion of adrenal steroid metabolites was measured (by GCMS) in 511 unrelated hypertensives from the Medical Research Council (MRC) British Genetics of Hypertension (BRIGHT) study. RESULTS: Thirty-five per cent of subjects were homozygous for the -344T allele whilst 16% were CC homozygotes. There was no difference in cortisol excretion rate between the two genotype groups but the index of adrenal 11beta-hydroxylation (ratio of tetrahydrodeoxycortisol/total cortisol) was significantly higher in the TT group (P < 0.005) than in the CC group. Excretion rates of the major urinary metabolite of aldosterone (tetrahydroaldosterone) correlated strongly with the ACTH-regulated steroids, cortisol (r = 0.437, P < 0.0001) and total androgen metabolites (r = 0.4, P < 0.0001) in TT but not CC subjects. CONCLUSIONS: Hypertensives homozygous for the -344 T allele of CYP11B2 demonstrate altered 11beta-hydroxylase efficiency (CYP11B1); this is consistent with the hypothesis of a genetically determined increase in adrenal ACTH drive in these subjects. The correlation between excretion of aldosterone and cortisol metabolites and suggests that, in TT subjects, ACTH exerts an important common regulatory influence on adrenal corticosteroid production in subjects with hypertension.


Assuntos
Citocromo P-450 CYP11B2/genética , Hipertensão/genética , Esteroide 11-beta-Hidroxilase/genética , Hormônio Adrenocorticotrópico/metabolismo , Idoso , Aldosterona/sangue , Alelos , Cortodoxona/sangue , Feminino , Genótipo , Humanos , Hipertensão/sangue , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética
9.
Kidney Int ; 71(8): 816-21, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17332732

RESUMO

Chronic kidney disease coexists with metabolic syndrome and this relationship may be apparent before overt manifestations of cardiovascular disease. To investigate early stages of the natural history of associations between renal function and metabolic syndrome, we phenotyped 1572 young (mean age=18.4 years), apparently healthy men for metabolic risk factors and estimated their creatinine clearance based on the Cockcroft-Gault equation. High metabolic risk (clustering of at least three metabolic risk factors) was revealed in 8.7% (137) of the subjects and was associated with a 6.9-fold increase in the odds of glomerular hyperfiltration (95% confidence interval (CI): 3.9-11.5) when compared to reference (from none to two metabolic risk factors). Overweight, elevated blood pressure, and low high-density lipoprotein (HDL) cholesterol increased the multivariate-adjusted odds ratio of glomerular hyperfiltration to 6.6 (95% CI: 3.8-11.6), 1.8 (95% CI: 1.0-3.0), and 2.5 (95% CI: 1.5-4.3), respectively. Systolic and diastolic blood pressures clustered together with leptin in the factor analysis and this blood pressure-adiposity component correlated with estimated creatinine clearance (r=0.329, P<0.0001) and explained on its own 10.2% of the variance in the estimated renal function. Our data reveal the silent epidemics of metabolic risk among young, apparently healthy men. Furthermore, the results indicate that high metabolic risk is associated with glomerular hyperfiltration before overt manifestations of cardiovascular disease.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Nefropatias/fisiopatologia , Síndrome Metabólica/fisiopatologia , Adolescente , Adulto , Fatores Etários , Biomarcadores , Creatinina/sangue , Humanos , Hiperglicemia/fisiopatologia , Nefropatias/complicações , Leptina/sangue , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Prevalência , Fatores de Risco
10.
Kidney Int ; 71(1): 68-73, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17136027

RESUMO

Decreased arterial compliance in end-stage renal disease (ESRD) is associated with increased cardiovascular risk. Our aim was to examine aortic compliance in patients with ESRD using cardiac magnetic resonance imaging (MRI) and to compare these with patients with advanced atherosclerotic disease who are known to be at high cardiovascular risk. We examined a total of 83 subjects matched for age: 24 had ESRD and were on dialysis therapy for 3+/-6 years, 24 had severe coronary artery disease (CAD), 11 had both ESRD and CAD (4+/-5 years on dialysis therapy), and 24 healthy subjects with no evidence of CAD. Vascular and cardiac function was assessed using cardiac MRI. Aortic compliance was significantly reduced in patients with CAD compared to control subjects (11.3+/-6.3 ml x 10(-3)/mm Hg vs 15.6+/-6.0 ml x 10(-3)/mm Hg, P=0.009). Patients with ESRD also exhibited significantly reduced aortic compliance compared to healthy controls (12.4+/-5.8 ml x 10(-3)/mm Hg vs 15.6+/-6.0 ml 10(-3)/mm Hg, P=0.012), whereas there was no significant difference in aortic compliance between patients with CAD and ESRD. Even in the absence of symptomatic CAD, patients with ESRD have significantly reduced aortic compliance compared to normal subjects. Patients with ESRD have equivalent aortic compliance to patients with advanced CAD. These findings suggest that a significantly reduced aortic compliance is one of many mechanisms promoting premature cardiovascular events in patients with ESRD compared to age-matched controls from the general population.


Assuntos
Vasos Sanguíneos/fisiopatologia , Doença da Artéria Coronariana/fisiopatologia , Falência Renal Crônica/fisiopatologia , Idoso , Aorta/fisiopatologia , Estudos de Casos e Controles , Doença da Artéria Coronariana/complicações , Feminino , Humanos , Hipertrofia Ventricular Esquerda/complicações , Hipertrofia Ventricular Esquerda/fisiopatologia , Falência Renal Crônica/complicações , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Resistência Vascular
11.
J Steroid Biochem Mol Biol ; 96(1): 89-91, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15896953

RESUMO

Brain aromatase has been shown to be increased in expression after neurotoxic damage and to exert neuroprotection via generation of local oestrogens. The present study investigates the topography and time course of brain aromatase expression after experimental stroke (middle cerebral artery occlusion (MCAO)). Ovariectomised stroke prone spontaneously hypertensive rats underwent distal MCAO by electrocoagulation. Immunohistochemistry revealed increased brain aromatase expression at 24h and 8 days in the cortical penumbra/peri-infarct zones with no increase evident at 2h or 30 days post-MCAO. Double label studies indicate that some of the increased aromatase expression is associated with astrocytic processes. Thus, this is the first evidence that aromatase protein is increased after MCAO and the location (peri-infarct), time course (within 24h) and cellular localisation (astrocytic) indicate the potential for aromatase to promote the survival of cells in the penumbra after experimental stroke by local synthesis of oestrogens.


Assuntos
Aromatase/metabolismo , Encéfalo/enzimologia , Infarto Cerebral/metabolismo , Acidente Vascular Cerebral/enzimologia , Animais , Encéfalo/patologia , Sobrevivência Celular , Modelos Animais de Doenças , Estrogênios/biossíntese , Feminino , Lateralidade Funcional , Proteína Glial Fibrilar Ácida/metabolismo , Artéria Cerebral Média/enzimologia , Artéria Cerebral Média/patologia , Ratos , Ratos Endogâmicos SHR , Acidente Vascular Cerebral/patologia
12.
Diabetologia ; 48(3): 539-46, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15729573

RESUMO

AIMS/HYPOTHESIS: Insulin-stimulated glucose transport is impaired in a genetic model of hypertension, the stroke-prone spontaneously hypertensive rat (SHRSP), yet the molecular mechanisms that underlie this defect in the animals remain unclear. METHODS: We examined the effects of insulin on the trafficking of the insulin-responsive glucose transporter GLUT4 to the plasma membrane in isolated adipocytes from SHRSP and normotensive control Wistar-Kyoto (WKY) rats. RESULTS: Treatment of isolated adipocytes with insulin resulted in trafficking of GLUT4 to the plasma membrane. There was no significant difference in the magnitude of insulin-stimulated GLUT4 trafficking from intracellular membranes to the plasma membrane between strains. In contrast, we demonstrated that there is a significant reduction in GLUT4 accessible to the glucose photolabel Bio-LC-ATB-BGPA at the plasma membrane of SHRSP adipocytes compared with control rats. CONCLUSIONS/INTERPRETATION: We propose that a large proportion of GLUT4 translocated to the plasma membrane in response to insulin is not able to bind substrate and catalyse transport in the SHRSP. Therefore, there is a reduction in bioavailable GLUT4 in SHRSP animals that is likely to account, at least in part, for the reduced insulin-stimulated glucose uptake.


Assuntos
Adipócitos/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Disponibilidade Biológica , Membrana Celular/metabolismo , Transportador de Glucose Tipo 4 , Insulina/farmacologia , Masculino , Proteínas de Transporte de Monossacarídeos/genética , Proteínas Musculares/genética , Reação em Cadeia da Polimerase , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismo , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo
13.
Stroke ; 36(1): 135-41, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15569870

RESUMO

BACKGROUND AND PURPOSE: To identify if the stroke-prone spontaneously hypertensive rat (SHRSP) exhibits impaired functional recovery after stroke compared with its normotensive reference strain, the Wistar Kyoto rat (WKY). METHODS: In study 1, a 2-mm distal middle cerebral artery occlusion (middle cerebral artery occlusion) was performed in both strains and recovery assessed using a 33-point neurological score. Because SHRSPs displayed much larger infarcts than WKYs, study 2 and study 3 involved extending the length of middle cerebral artery (MCA) occlusion in the WKY to increase the volume and distribution of infarction to comparable levels with SHRSP. Animals were assessed with the neurological score, tapered beam walk, and cylinder tests. RESULTS: In study 1, infarct volume (expressed as a percent of contralateral hemisphere) was WKY 13.1+/-3% and SHRSP 19.8+/-1%. Initial neurological deficit was greater (WKY 25+/-1, SHRSP 22+/-1, out of a possible 33) and subsequent recovery was poorer in SHRSP. In studies 2 and 3, infarct volume and distribution (study 2, WKY 21.8+/-1.3%, SHRSP 22.9+/-3%; study 3, WKY 17.2+/-2%, SHRSP 16.5+/-3%) and initial neurological deficit at 2 hours after middle cerebral artery occlusion (study 2 WKY 23+/-1, SHRSP 22+/-2; study 3 WKY 25+/-1 and SHRSP 23+/-1; mean+/-SEM) were comparable between strains. However, whereas WKY recovered toward normal scores, SHRSP scored significantly lower 2 weeks (study 2) and 4 weeks (study 3) after middle cerebral artery occlusion. Beam walk data revealed long-term impairment in SHRSP contralateral limb use, compared with WKY, at days 3, 7, and 28 (P<0.05). CONCLUSIONS: SHRSP exhibit impaired functional recovery after stroke compared with WKY.


Assuntos
Hipertensão/complicações , Acidente Vascular Cerebral/fisiopatologia , Animais , Comportamento Animal , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/patologia , Masculino , Atividade Motora , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Acidente Vascular Cerebral/etiologia
15.
J Hum Hypertens ; 17(2): 81-6, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12574784

RESUMO

Prospective comparisons of different drug classes have shown that differences in blood pressure control, rather than differences between drug classes, have the over-riding influence on overall outcome. The same studies have also reinforced the need, in the majority of patients, to use combinations of drugs in order to achieve the target of <140/85 mmHg. By contrast, most patients in routine practice receive single agents and consequently fail to achieve target blood pressure. This failure reflects in part the emphasis in individual studies and subsequent guidelines on comparison of individual drugs. In this article we show how the consistency of both theory and a broad range of evidence permits a didactic approach to combination therapy. Our advice is based on the growing recognition that essential hypertension and its treatment fall into two main categories. Younger Caucasians usually have renin-dependent hypertension that responds well to angiotensin-converting-enzyme inhibition or angiotensin receptor blockade (A) or ss blockade (B). Most other patients have low-renin hypertension that responds better to calcium channel blockade (C) or diuretics (D). These latter drugs activate the renin system rendering patients responsive to the addition of renin suppressive therapy. Coincidence of the initials of these main drug classes with the first four letters of the alphabet permits an AB/CD rule, according to which recommended combinations are one drug from each of the "AB" and "CD" categories of drugs. However, the diabetogenic potential of the older "B" and "D" classes leads us to advise against combining "B" and "D" in older patients, and to recommend "A" + "C" + "D" as standard triple therapy for resistant hypertension.


Assuntos
Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Anti-Hipertensivos/farmacologia , Quimioterapia Combinada , Humanos
16.
Hum Reprod ; 17(7): 1918-24, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12093861

RESUMO

BACKGROUND: Estradiol exerts a number of biological effects that support extensive observational data suggesting a protective role for estrogen in cardiovascular disease prevention. These include effects on lipid and carbohydrate metabolism, coagulation/fibrinolysis as well as a possible effect on vascular reactivity. It has been proposed that this might be mediated by vascular endothelial nitric oxide (NO) production. Accordingly, we designed complementary in-vivo and in-vitro studies to investigate this hypothesis further. METHODS: Firstly, in a group of 10 healthy post-menopausal women, bilateral venous occlusion plethysmography was used to examine forearm vasoconstrictor responses to intrabrachial N(G)-monomethyl-l-arginine (l-NMMA; a substrate inhibitor of nitric oxide synthase) both before and after 4 weeks of treatment with transdermal 17beta-estradiol (E(2)) (80 microg/day). Secondly, we examined the direct effects of acute (24 h) and chronic (7 days) treatment with E(2) (10 pmol/l and 10 nmol/l) on endothelial nitric oxide synthase (eNOS) gene expression in cultured human aortic endothelial cells. RESULTS: No significant differences were observed between the vasoconstrictor responses to l-NMMA (2, 4, 8 micromol/min) before and after E(2) treatment. Comparison of E(2)-treated endothelial cells with control cells showed no significant increase in eNOS mRNA expression following either acute or chronic estradiol treatment. CONCLUSIONS: The present studies do not provide evidence for an eNOS-mediated cardioprotective response to estrogen and therefore suggest that additional mechanisms other than the endothelial NO system may have an important role in the cardiovascular effects of estrogen.


Assuntos
Cardiotônicos/farmacologia , Estradiol/farmacologia , Óxido Nítrico/fisiologia , Administração Cutânea , Adulto , Aorta/citologia , Aorta/metabolismo , Artéria Braquial , Cardiotônicos/administração & dosagem , Células Cultivadas , Sinergismo Farmacológico , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Estradiol/administração & dosagem , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Feminino , Antebraço/irrigação sanguínea , Humanos , Injeções Intra-Arteriais , Pessoa de Meia-Idade , Óxido Nítrico/genética , RNA Mensageiro/biossíntese , Receptores de Estrogênio/genética , Vasoconstrição , ômega-N-Metilarginina/administração & dosagem , ômega-N-Metilarginina/farmacologia
17.
Scott Med J ; 47(1): 7-9, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11980293

RESUMO

The localisation of quantitative trait loci (QTL) is the first step towards gene identification. This is then verified by the construction of reciprocal congenic strains. The hypertensive SHRSP and normotensive WKY strains were used in a speed congenic approach to confirm the existence of a QTL on rat chromosome 2. Systolic baseline and salt loaded blood pressures were measured by radiotelemetry. Transfer of the chromosome 2 blood pressure QTL region from WKY into an SHRSP background significantly reduced blood pressure, with the increased significance at the salt loaded period, compared to the SHRSP. The reciprocal congenic blood pressure showed a significantly increased baseline systolic pressure compared to the WKY, with no change in significance at the salt loaded period. Thus we have successfully captured a gene(s) which contribute to blood pressure regulation in both congenic strains. This will facilitate further positional cloning of the causative genes first in this model and then in human essential hypertension.


Assuntos
Pressão Sanguínea/genética , Hipertensão/genética , Característica Quantitativa Herdável , Análise de Variância , Animais , Animais Congênicos , Mapeamento Cromossômico , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
18.
Gene Ther ; 9(2): 110-7, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11857069

RESUMO

Gene transfer may be appropriate for therapeutic protocols targeted at the vascular endothelium. Endothelial dysfunction is the principal phenotype associated with atherosclerosis and hypertension. Oxidative stress has been implicated in the development of endothelial dysfunction. We have explored the ability of overexpressing anti-oxidant genes (superoxide dismutases; SODs) in vitro and in vivo to assess their potential for reversing endothelial dysfunction in a rat model, the stroke-prone spontaneously hypertensive rat (SHRSP). Western blotting and immunofluorescence assays in vitro showed efficient overexpression of MnSOD and ECSOD with respect to localisation to the mitochondria and extracellular surface, respectively. Transgene functional activity was quantified with SOD activity assays. MnSOD and ECSOD overexpression in intact SHRSP vessels in vivo led to endothelial and adventitial overexpression. Pharmacological assessment of transduced vessels following in vivo delivery by basal NO availability quantification demonstrated that the "null" adenovirus and MnSOD adenovirus did not significantly increase NO availability. However, AdECSOD-treated carotid arteries showed a significant increase in NO availability (1.91 +/- 0.04 versus 0.75 +/- 0.08 g/g, n = 6, P = 0.029). In summary, efficient overexpression of ECSOD, but not MnSOD in vivo, results in improved endothelial function in a rat model of hypertension and has important implications for the development of endothelial-based vascular gene therapy.


Assuntos
Endotélio Vascular/fisiopatologia , Sequestradores de Radicais Livres/metabolismo , Terapia Genética/métodos , Hipertensão/terapia , Superóxido Dismutase/metabolismo , Adenoviridae/genética , Animais , Western Blotting , Células Cultivadas , Técnicas de Transferência de Genes , Vetores Genéticos/uso terapêutico , Hipertensão/enzimologia , Hipertensão/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos SHR , Superóxido Dismutase/genética
19.
Atherosclerosis ; 160(2): 345-53, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11849657

RESUMO

Radial arteries, used in revascularisation surgery, are prone to spasm. We have examined the ability of nitrovasodilators, calcium channel blockers, and K(ATP) channel openers to cause vasodilation, and to attenuate contractions due to depolarisation and receptor activation in radial and mammary arteries used in coronary artery bypass graft surgery. Two to three millimetre rings of artery obtained from patients at surgery were studied in organ baths in vitro. Constriction to KC1 and phenylephrine was examined before and again after treatment of the rings with drug or vehicle. Calcium channel blockers were the only compounds to inhibit contractions to both KC1 and phenylephrine. Sodium nitroprusside attenuated constriction to phenylephrine but not KC1 in both vessels. K(ATP) channel openers similarly attenuated constriction to phenylephrine in radial arteries but were much less effective in mammary arteries. These studies support the continued use of calcium blockers after revascularisation with radial artery but suggest that other classes of drug may be as effective at minimising spasm due to receptor mediated constriction.


Assuntos
Artéria Torácica Interna/fisiologia , Artéria Radial/fisiologia , Vasoconstrição/efeitos dos fármacos , Vasodilatadores/farmacologia , Adulto , Idoso , Bloqueadores dos Canais de Cálcio/farmacologia , Ponte de Artéria Coronária , Cromakalim/farmacologia , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Artéria Torácica Interna/efeitos dos fármacos , Pessoa de Meia-Idade , Nicorandil/farmacologia , Nitroprussiato/farmacologia , Fenilefrina/farmacologia , Cloreto de Potássio/farmacologia , Artéria Radial/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
20.
Mol Ther ; 4(6): 534-42, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11735337

RESUMO

Adenovirus type 5 (Ad) based vectors transduce vascular endothelial cells (EC) and have been widely used for vascular gene transfer. However, many cell types express the Ad receptor (cox-sackievirus adenovirus receptor; CAR), preventing selective EC infection and precluding clinical use. We previously isolated the human EC-binding peptides SIGYPLP and LSNFHSS by phage display and demonstrated by means of a bispecific antibody that SIGYPLP directs efficient, high-level, EC-selective Ad-mediated gene transfer. We now generate genetically modified Ad fiber proteins with selective EC tropism by engineering these peptides into the HI loop of the Ad fiber. SIGYPLP, but not LSNFHSS, enhanced EC selectivity, demonstrating maintenance of peptide-cell binding fidelity upon incorporation into virions. Combining fiber mutations that block CAR binding (detargeting) with SIGYPLP insertion (retargeting) generated a novel Ad vector, AdKO1SIG, in a single component system. AdKO1SIG demonstrated efficient and selective tropism for EC compared with control Ad vectors. This is the first demonstration of genetic incorporation of a novel, mammalian, cell-selective ligand that retains its targeting fidelity in the Ad fiber HI loop, in combination with point mutations that abolish fiber-CAR interaction. This study demonstrates the potential for improving the cell-selectivity and safety of adenoviral vectors.


Assuntos
Adenoviridae/fisiologia , Endotélio Vascular/virologia , Terapia Genética/métodos , Fragmentos de Peptídeos/genética , Receptores Virais/metabolismo , Sítios de Ligação , Ligação Competitiva , Células Cultivadas , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Primers do DNA/química , Citometria de Fluxo , Marcação de Genes/métodos , Vetores Genéticos , Proteínas de Fluorescência Verde , Humanos , Immunoblotting , Proteínas Luminescentes/metabolismo , Plasmídeos/genética , Receptores Virais/genética , Linfócitos T/metabolismo , Transdução Genética , Transfecção
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