RESUMO
OBJETIVO: identificar la asociación de las determinantes de la seguridad alimentaria con el sobrepeso y obesidad de la población que acude a la Unidad de Epidemiología Clínica del IINSAD de la Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica UMSA. MATERIAL Y MÉTODO: estudio de Casos y Controles, desarrollado en la Unidad de Epidemiologia Clínica del IINSAD de la Facultad de Medicina, UMSA. Ingresaron al estudio 288 personas, 144 casos y 144 controles, se aplicó la encuesta alimentaria, identificando el consumo y la frecuencia de alimentos y preguntas específicas sobre disponibilidad, acceso físico y económico a los alimentos. Se realizó una evaluación antropométrica para identificar los casos y controles. RESULTADOS: existe una probabilidad mayor de presentar sobrepeso u obesidad en la población con insuficiente acceso económico a los alimentos OR= 2.1 (IC95% 1.3-3.6 p=0.003). A mayor proporción de gasto en alimentos de una familia, mayor es el consumo de energía provenientes de carbohidratos y grasas OR= 30 (IC95% 23.6-58.8) p=0.000. No se encontró asociación entre la disponibilidad de alimentos y el lugar de aprovisionamiento. CONCLUSIONES: son factores asociados para la presencia de sobrepeso y obesidad los determinantes de seguridad alimentaria nutricional como ingreso destinado a la compra de los alimentos, el consumo alimentario en cantidad y calidad de la dieta consumida y adecuación de nutrientes, la disponibilidad de alimentos y el lugar de aprovisionamiento no presenta asociación
OBJECTIVE: to identify the association of food security determinants of overweight and obesity in the population attending the Clinical Epidemiology Unit of IINSAD Faculty of Medicine, Nursing, Nutrition and Medical Technology - UMSA La Paz, 2015. MATERIAL AND METHODS: an observational analytical case-control study, 288 individuals attending the IINSAD of the Faculty of Medicine, Nursing, Nutrition and Medical Technology - UMSA. 144 cases and 144 controls were analyzed. A food survey, where the consumption and food frequency and specific questions about availability, physical and economic access to food occurred was applied. Anthropometric assessment was performed to identify cases and controls. RESULTS: there is a greater likelihood of becoming overweight or obese in people with insufficient economic access to food OR = 2.1 (95% CI 1.3-3.6 p = 0.003). The greater the food expenditure proportion of a family, the greater is the consumption the energy from carbohydrates and fats OR = 30 (95% CI 23.6-58.8 p = 0.000). No association between the availability of food and the place of supply is found. CONCLUSIONS: there are factors associated to the presence of overweight and obesity determinants of nutritional food security such as income for the purchase of food, food consumption in quantity and quality of consumed diet and nutrient adequacy, the availability of food and the place of supplying is not considered associated for this study
Assuntos
Humanos , Nutrientes/deficiência , Epidemiologia Nutricional , Alimentos, Dieta e Nutrição , ObesidadeRESUMO
Because of their high electrical conductivity CoSi2 nanostructures are potential candidates for preparing ordered nano-arrays to be used as electrode interconnectors and contacts in microelectronic devices. We here describe a controlled procedure for the endotaxial growth of hexagonal CoSi2 nanoplatelets buried in differently oriented single crystalline Si wafers on which a Co-doped SiO2 thin film was previously deposited. These nanomaterials were obtained by a clean procedure consisting of isothermal annealing at 750 °C under a He atmosphere of Co-doped SiO2 thin films deposited onto the surface of three differently oriented flat Si substrates, namely Si(001), Si(011) and Si(111). Buried CoSi2 nanoplatelets are in all cases spontaneously formed as a consequence of the diffusion of Co atoms into the silicon wafer and their reaction with host Si atoms. Our TEM and GISAXS analyses demonstrated that these arrays, irrespective of host Si orientation, consist of CoSi2 hexagonal nanoplatelets in all cases parallel to Si{111} crystallographic planes. Additionally, the dimensions of the nanoplatelets were consistently determined by TEM and GISAXS for the three different host Si single crystal orientations.
RESUMO
Nowadays, the implementation of sophisticated in situ electron microscopy tests is providing new insights in several areas. In this work, an in situ high-temperature strain test into a scanning electron microscope was developed. This setup was used to study the grain boundary sliding mechanism and its effect on the ductility dip cracking. This methodology was applied to study the mechanical behaviour of Ni-base filler metal alloys ERNiCrFe-7 and ERNiCr-3, which were evaluated between 700°C and 1000°C. The ductility dip cracking susceptibility (threshold strain; εmin) for both alloys was quantified. The εmin of ERNiCrFe-7 and ERNiCr-3 alloys were 7.5% and 16.5%, respectively, confirming a better resistance of ERNiCr-3 to ductility dip cracking. Furthermore, two separate components of grain boundary sliding, pure sliding (Sp) and deformation sliding (Sd), were identified and quantified. A direct and quantitative link between grain boundary tortuosity, grain boundary sliding and ductility dip cracking resistance has been established for the ERNiCrFe-7 and ERNiCr-3 alloys.
RESUMO
Vampire bat rabies causes significant impacts within its endemic range in Mexico. These impacts include livestock mortality, animal testing costs, post-exposure prophylaxis costs, and human mortality risk. Mitigation of the impacts can be achieved by vaccinating livestock and controlling vampire bat populations. A benefit-cost analysis was performed to examine the economic efficiency of these methods of mitigation, and Monte Carlo simulations were used to examine the impact that uncertainty has on the analysis. We found that livestock vaccination is efficient, with benefits being over six times higher than costs. However, bat control is inefficient because benefits are very unlikely to exceed costs. It is concluded that when these mitigation methods are judged by the metric of economic efficiency, livestock vaccination is desirable but bat control is not.
Assuntos
Doenças dos Bovinos/economia , Quirópteros/virologia , Surtos de Doenças/economia , Vacina Antirrábica/economia , Vírus da Raiva/imunologia , Raiva/veterinária , Vacinação/veterinária , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/virologia , Análise Custo-Benefício , Surtos de Doenças/prevenção & controle , Surtos de Doenças/veterinária , Reservatórios de Doenças/veterinária , Reservatórios de Doenças/virologia , México/epidemiologia , Raiva/economia , Raiva/prevenção & controle , Raiva/virologia , Vacina Antirrábica/administração & dosagem , Vacinação/economiaRESUMO
High-resolution transmission electron microscopy (HRTEM) and ab initio quantum-mechanical calculations of electronic structure were combined to investigate the structure of the hydroxyapatite (HA) (010) surface, which plays an important role in HA interactions with biological media. HA was synthesized by in vitro precipitation at 37°C. HRTEM images revealed thin elongated rod nanoparticles with preferential growth along the [001] direction and terminations parallel to the (010) plane. The focal series reconstruction (FSR) technique was applied to develop an atomic-scale structural model of the high-resolution images. The HRTEM simulations identified the coexistence of two structurally distinct terminations for (010) surfaces: a rather flat Ca(II)-terminated surface and a zig-zag structure with open OH channels. Density functional theory (DFT) was applied in a periodic slab plane-wave pseudopotential approach to refine details of atomic coordination and bond lengths of Ca(I) and Ca(II) sites in hydrated HA (010) surfaces, starting from the HRTEM model.
Assuntos
Durapatita/química , Nanopartículas , Microscopia Eletrônica de Transmissão , Modelos Moleculares , Difração de Pó , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
Non-modulating is a highly reproducible type of sodium-sensitive hypertension. The aim of this study was to evaluate in non-modulating individuals the erythrocyte sodium-lithium countertransport (SLC) abnormalities, which have been mentioned as a marker of non-modulation, and the association with increased microalbuminuria, as a marker of an early kidney impairment. We measured erythrocyte SLC in 10 normotensives (NT, 28 +/- 4 years), 20 offspring of hypertensive parents being 10 modulating (MHO, 25 +/- 6 years) and 10 non-modulating (NMHO, 26 +/- 5 years), and 23 essential hypertensives being 12 modulating (MHT, 34 +/- 5 years) and 11 non-modulating (NMHT, 32 +/- 4 years). In all the subjects studied, microalbuminuria was determined by duplicate 24-h urine collection by radioimmunoassay. In non-modulating offspring of hypertensive parents and essential hypertensives. SLC was significantly elevated when compared either with normotensives without family history of hypertension, modulating offspring of hypertensive parents or essential hypertensives (P < 0.025). Likewise, 24-h urinary albumin excretion was found higher in non-modulating individuals (essential hypertensives and offspring of hypertensive parents) than in modulating individuals (P < 0.01). In conclusion, non-modulators with higher SLC countertransport sodium transport abnormalities showed higher elimination of microalbuminuria suggesting that non-modulators may have an increased risk for developing cardiovascular morbidity and kidney impairment even in normotensive subjects with familiarity history of hypertension.
Assuntos
Albuminúria/complicações , Antiporters/metabolismo , Eritrócitos/metabolismo , Hipertensão/genética , Hipertensão/metabolismo , Adulto , Análise de Variância , Transporte Biológico , Feminino , Humanos , Hipertensão/complicações , Masculino , Fatores de Risco , Estatísticas não ParamétricasRESUMO
The aim of this study was to compare the mechanical and intrinsic effects of an angiotensin converting enzyme inhibitor, vs a beta-blocker, on brachial arterial compliance. In a double blind study, 34 essential hypertensive patients were treated for 3 months with either ramipril 2.5-5.0 mg daily (n = 17, age 57 +/- 7 y, 11 males) or atenolol 50-100 mg daily (n = 17, age 53 +/- 8 y, 11 males). Blood pressure (BP), brachial artery diameter (D), brachial-radial pulse wave velocity (PWV) and effective compliance (Ceff), were measured before and at the end of the study. Isobaric evaluation (Ciso) was performed in the entire population studied at an average mean BP of 110 mmHg. Ramipril significantly reduced BP from 155 +/- 16/94 +/- 6 mmHg to 140 +/- 15/85 +/- 7 mmHg (p < 0.001) without affecting heart rate (HR; 74 +/- 10 vs. 75 +/- 12 bpm). In addition, it significantly improved both PWV (18%; p < 0.001) and arterial compliance (45%; p < 0.001), from which 35% was related to a pressure independent effect (p < 0.01). Atenolol also induced a reduction in both BP (159 +/- 17/96 +/- 10 to 133 +/- 13/81 +/- 8 mmHg; p < 0.001) and HR (76 +/- 10 to 57 +/- 7 bpm; p < 0.001). In a similar way, PWV (11%; p < 0.05) and Ceff (30%; p < 0.05) were significantly improved without significant change in Ciso. This suggests that blood pressure reduction was responsible for compliance improvement. In conclusion, it is suggested that atenolol induces only hemodynamic changes, mediated mainly by BP reduction. In contrast, the improved brachial buffering function observed after ramipril involves not only hemodynamic changes, but also changes mediated by other mechanisms, such as modification of wall structures.
Assuntos
Anti-Hipertensivos/farmacologia , Atenolol/farmacologia , Artéria Braquial/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Ramipril/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Artéria Braquial/fisiopatologia , Complacência (Medida de Distensibilidade) , Método Duplo-Cego , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-IdadeRESUMO
The metabolic syndrome is a complex association of several risk factors including insulin resistance, dyslipidemia, and essential hypertension. Insulin resistance has been associated with sympathetic activation and endothelial dysfunction, which are the main mechanisms involved in the pathophysiology of hypertension and its related cardiovascular risk. According to the Sixth Report of the Joint National Committee, and guidelines of the World Health Organization/International Society of Hypertension, the presence of multiple risk markers suggests that both hypertension and risk factors should be aggressively managed in order to obtain a better outcome. Primary prevention of obesity at different levels--individual, familial, and social-- starting early in childhood has proven to be cost effective, and will be mandatory to reduce the world epidemic of obesity and its severe consequences.
Assuntos
Doenças Cardiovasculares/fisiopatologia , Hipertensão/fisiopatologia , Doenças Metabólicas/etiologia , Humanos , Fatores de RiscoRESUMO
In this articulate it summarised the objectives and results of the National Program of Tuberculosis during 1999, when the rate of Tuberculosis all the forms were of 26.1 x 100.000 habitants and with results of 80% of cures in the cohort corresponding to 1998, the recommendations also included to improve the execution of the same one.
Assuntos
Programas Nacionais de Saúde , Tuberculose/prevenção & controle , Estudos de Coortes , Humanos , Avaliação de Programas e Projetos de Saúde , Tuberculose/tratamento farmacológico , VenezuelaRESUMO
The aim of this study was to compare the mechanical and intrinsic effects of an angiotensin converting enzyme inhibitor, vs a beta-blocker, on brachial arterial compliance. In a double blind study, 34 essential hypertensive patients were treated for 3 months with either ramipril 2.5-5.0 mg daily (n = 17, age 57 +/- 7 y, 11 males) or atenolol 50-100 mg daily (n = 17, age 53 +/- 8 y, 11 males). Blood pressure (BP), brachial artery diameter (D), brachial-radial pulse wave velocity (PWV) and effective compliance (Ceff), were measured before and at the end of the study. Isobaric evaluation (Ciso) was performed in the entire population studied at an average mean BP of 110 mmHg. Ramipril significantly reduced BP from 155 +/- 16/94 +/- 6 mmHg to 140 +/- 15/85 +/- 7 mmHg (p < 0.001) without affecting heart rate (HR; 74 +/- 10 vs. 75 +/- 12 bpm). In addition, it significantly improved both PWV (18
; p < 0.001) and arterial compliance (45
; p < 0.001), from which 35
was related to a pressure independent effect (p < 0.01). Atenolol also induced a reduction in both BP (159 +/- 17/96 +/- 10 to 133 +/- 13/81 +/- 8 mmHg; p < 0.001) and HR (76 +/- 10 to 57 +/- 7 bpm; p < 0.001). In a similar way, PWV (11
; p < 0.05) and Ceff (30
; p < 0.05) were significantly improved without significant change in Ciso. This suggests that blood pressure reduction was responsible for compliance improvement. In conclusion, it is suggested that atenolol induces only hemodynamic changes, mediated mainly by BP reduction. In contrast, the improved brachial buffering function observed after ramipril involves not only hemodynamic changes, but also changes mediated by other mechanisms, such as modification of wall structures.
RESUMO
BACKGROUND: A new procedure to improve the accuracy of inulin assessment and renal glomerular filtration rate (GFR) avoiding urine sampling was compared and validated versus the reference procedure (with urine sampling and Anthrone reaction) in conscious unrestrained male Wistar rats. METHODS: The hemodynamic study consisted of a priming dose of inulin (16 mg/kg) and para-aminohippurate (PAH; 8 mg/kg) followed by an infusion of inulin (36 mg/mL) and PAH (5.8 mg/mL) at a rate of 0.055 mL/min until steady-state conditions were reached (105 min). Inulin concentrations from samples were determined by a new enzymatic assay and Anthrone reaction. PAH concentrations were determined according to the standard method described by Smith et al. RESULTS: A high correlation was found between GFR and renal blood flow (RBF) values calculated using the alternative (without urine sampling) and the reference (with urine sampling) clearance techniques (r = 0.98, P < 0.001, and r = 0.97, P < 0.001, respectively). Moreover, a significant and positive correlation between the values obtained from enzymatic and Anthrone inulin assessments was found (r = 0.99, P < 0.001). Likewise, the values of the 95% confidence interval (mean +/- 2 SD) for the enzymatic inulin assay showed a good agreement with those achieved with Anthrone (1.14 +/- 0.21 and 1.14 +/- 0.19 mL. min-1. 100 g-1 rat body weight, respectively). CONCLUSIONS: This new approach has methodological and experimental advantages with respect to traditional procedures, making it a useful tool, not only for research purposes but also in the clinical setting.
Assuntos
Taxa de Filtração Glomerular , Inulina , Circulação Renal , Ácido p-Aminoipúrico , Animais , Inulina/farmacocinética , Nefropatias/diagnóstico , Modelos Lineares , Masculino , Ratos , Ratos Wistar , Sensibilidade e Especificidade , Urina , Ácido p-Aminoipúrico/farmacocinéticaRESUMO
Non-modulators are a subset of essential hypertensive individuals in whom renal hemodynamic and adrenal aldosterone responses to angiotensin II fail to modulate appropriately during high dietary salt intake. The main aim of this study was to investigate the familial aggregation of non-modulation and several erythrocyte Na+ transport systems in normotensive and hypertensive individuals as well as offspring of hypertensive parents. An additional aim was to evaluate the effect of treatment with enalapril on erythrocyte Na+ transport. We studied 15 normotensive subjects (6 males, 27+/-6 years), 14 untreated modulating essential hypertensive subjects (7 males, 38+/-7 years), 12 untreated non-modulating essential hypertensive subjects (7 males, 38+/-6 years), 14 modulating offspring of hypertensive parents (8 males, 25+/-6 years), and 14 non-modulating offspring of hypertensive parents (8 males, 26+/-4 years). Blood pressure was recorded with an oscillometric device and renal plasma flow and glomerular filtration rate by clearances of para-aminohippurate and inulin, respectively. Non-modulating subjects were identified as individuals who failed to increase effective renal plasma flow by 30% and decrease filtration fraction by at least 30% 10 days after changing from a low (20 mmol/d) to a high (250 mmol/d) sodium intake. Erythrocyte Na+ transport was characterized by measurements of the Na+-K+ pump, Na+-Li+ countertransport, Na+-K+-Cl- cotransport, passive Na+ permeability, and Na+ content. After the initial studies, hypertensive individuals were treated with enalapril (20 mg/d P.O.) for 6 months, after which erythrocyte Na+ transport measurements were again made. The main findings were that Na+-Li+ countertransport is increased in non-modulating hypertensive subjects and non-modulating offspring of hypertensive parents, that the increase in blood pressure in response to high salt intake is greater in non-modulating than modulating hypertensive subjects, and that enalapril decreases Na+-Li+ countertransport activity to normal in non-modulating hypertensive subjects. These findings provide support for a possible genetic role in the development of salt sensitivity and suggest that Na+-Li+ countertransport and non-modulation are related phenotypes.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Enalapril/uso terapêutico , Eritrócitos/metabolismo , Hipertensão/tratamento farmacológico , Hipertensão/genética , Lítio/sangue , Sódio/sangue , Adulto , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Transporte Biológico , Cloretos/metabolismo , Interpretação Estatística de Dados , Enalapril/administração & dosagem , Feminino , Humanos , Hipertensão/metabolismo , Lítio/análise , Masculino , Pessoa de Meia-Idade , Sódio/análise , Sódio/metabolismo , Sódio na Dieta/efeitos adversos , ATPase Trocadora de Sódio-Potássio/metabolismo , Espectrofotometria Atômica , Fatores de TempoRESUMO
BACKGROUND: Non-modulating hypertensives are a subset of sodium-sensitive hypertensives characterized by a failure to modulate renal, vascular and adrenal glomerulosa responsivenesses to angiotensin II appropriately. OBJECTIVE: To investigate the plasma renin activity (PRA) and urinary kallikrein-like activity (Ku) under different sodium conditions in essential hypertensive patients and in the modulating and non-modulating subsets of hypertensives. Additionally, in these groups of patients, the effects on blood pressure of a sustained Na+ restriction were evaluated. METHODS: Fifteen normotensives (10 men, aged 29 +/- 5 years) and 54 untreated hypertensives (30 men, aged 34 +/- 7 years) were each administered subsequently three different diets containing 240, 140 and 50 mmol/day Na+, each diet for 10 days. At the end of each period, the PRA, Ku, 24 h urinary volume and urinary Na+ excretion were measured. Afterwards, the essential hypertensives were classified as 29 modulating essential hypertensives (MHT, 20 men, aged 32 +/- 7 years) and 25 non-modulating essential hypertensives (NMHT, 10 men, aged 36 +/- 8 years). Non-modulating ones were identified as individuals who failed to increase their effective renal plasma flow and to decrease their filtration fraction by at least 30% from baseline values, 10 days after changing from a low (10 mmol/day) to a high (260 mmol/day) Na+ intake. Blood pressure was measured with a Dinamap 8100 Critikon device. Both PRA and Ku were measured during normal Na+ intake by standard methods. Patients were administered a low-Na+ diet (10-50 mmol/day) for 12 months. RESULTS: In essential hypertensives, Ku was lower under the three Na+ diets than it was in normotensives (P < 0.01) whereas the PRA was higher in hypertensives only during the low Na+ intake (P < 0.01). The non-modulating patients showed significantly higher PRA levels (4.0 +/- 0.8 ng ml h, P < 0.05) than did modulating ones (2.6 +/- 1.0 ng ml h) or normotensives (2.3 +/- 1.0 ng ml h). Conversely, non-modulating hypertensives had lower Ku (4.1 +/- 1.0 IU/24 h, P < 0.025) than did modulating ones (6.2 +/- 1.0 IU/24 h) or normotensives (7.8 +/- 2.0 IU/24 h). Blood pressure was significantly reduced during low Na+ intake only in normotensives (month 6: 143 +/- 4/94 +/- 2 mmHg; month 12: 139 +/- 5/89 +/- 3 mmHg) compared with baseline values (169 +/- 4/102 +/- 6 mmHg, P < 0.025). CONCLUSIONS: It was shown that, in non-modulating hypertensives, in addition to an increased PRA, a reduced kallikrein-like activity coexists and seems to be associated with the impaired Na+ handling. Moreover, in these untreated patients the Na+ restriction was able to exert an antihypertensive effect even for long periods.
Assuntos
Dieta Hipossódica , Hipertensão/fisiopatologia , Sistema Renina-Angiotensina , Adulto , Pressão Sanguínea , Taxa de Filtração Glomerular , Humanos , Hipertensão/dietoterapia , Masculino , Natriurese , Renina/sangueRESUMO
OBJECTIVE: To study the effect of treatment with cilazapril versus nifedipine on the glomerular filtration rate (GFR), microalbumin excretion rate (mu Alb) and baseline plasma renin activity (PRA) levels in non-diabetic or diabetic essential hypertension. DESIGN AND METHODS: Thirty-four moderate essential hypertensives and thirty-two type II diabetic hypertensives with currently normal renal function completed the study, receiving treatment with a converting enzyme inhibitor (CEI, 5-10 mg/day cilazapril) or a non-CEI (20-40 mg slow-release nifedipine three times a day) during a 12-month controlled follow-up study. RESULTS: Either treatment induced a similar reduction in blood pressure. Patients with PRA > 3 ng/ml per h treated with cilazapril showed a proportional increase in GFR, whereas in those treated with a non-CEI there was a decline in GFR after 8 and 12 months. Only diabetic patients treated with cilazapril showed a mu Alb reduction associated with a stable GFR. CONCLUSION: PRA predicts the effect of CEI preserving renal function in essential and diabetic hypertension.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Hipertensão/fisiopatologia , Rim/efeitos dos fármacos , Renina/sangue , Adolescente , Adulto , Idoso , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-IdadeRESUMO
The atmospheric particulates from the Caracus Valley in Venezuela and the fluvial particulates transported by the Tuy River into the Caribbean sea have been evaluated for Pb, Cu and Zn with the purpose of determining the contamination levels in the study area. The atmospheric particulate samples were collected in the city of Caracas using a low volume sampler whereas the fluvial particulate were collected at the mouth of the Tuy River. The particulate samples were analysed by flame or graphite furnace atomic absorption spectrometry depending upon the concentration levels of the heavy metal under study. The results obtained for the fluvial particulates enabled estimates to be made of the total anthropogenic flux of Cu (383 ton year(-1)), Pb (528 ton year(-1)) and Zn (865 ton year(-1)). These results yield annual per capita inputs for Cu (96 g),Pb (132 g) and Zn (216 g) which greatly exceed those from global anthropogenic emissions. The weighted average concentration of Pb (1.13 %) found in the atmospheric particulates was much higher than those for Cu (140 mg kg(-1)) and Zn (200 mg kg(-1)) and reflects the high motor car traffic in the Caracas Valley. The anthropogenic/natural ratios estimated in this study were as follows: 2.6 for Pb; 1.5 for Cu and 1.5 for Zn. This indicates that anthropogenic inputs for Cu, Pb, and Zn in the study area exceed those from natural sources, cars being the major source for Pb and industrial activities the major sources for Cu and Zn.
RESUMO
1. The participation of 5-HT2 receptors in the modulation of the evoked release of [3H]noradrenaline from rat spinal cord slices has been examined. 2. In rat spinal cord slices preincubated with [3H]noradrenaline, the alpha 2-receptor agonist clonidine (10(-6) mol/l) decreased the release of tritium evoked by field stimulation (600 pulses at 5 Hz, 20 mA, 2 msec), while the alpha 2-antagonist yohimbine (10(-6) mol/l) increased it. 3. The 5-HT2/5-HT1c agonist DOI (3 x 10(-7) mol/l) decreased the evoked release of tritium, an effect which was prevented by ketanserin (10(-7) mol/l). 4. It is suggested that in addition to presynaptic alpha 2-adrenoceptors, there are 5-HT2 receptors which modulate the release of noradrenaline in the rat spinal cord.
Assuntos
Norepinefrina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , Medula Espinal/metabolismo , Anfetaminas/farmacologia , Animais , Clonidina/farmacologia , Estimulação Elétrica , Feminino , Alucinógenos/farmacologia , Técnicas In Vitro , Ketanserina/farmacologia , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa/efeitos dos fármacos , Receptores Adrenérgicos alfa/metabolismo , Medula Espinal/efeitos dos fármacos , Ioimbina/farmacologiaRESUMO
In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1%) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2%, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5% and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected
Assuntos
Humanos , Masculino , Feminino , Exercício Físico/fisiologia , Hipertensão/fisiopatologia , Função Ventricular Esquerda , Adulto , Idoso , Diástole , Ecocardiografia , Teste de Esforço , Imagem do Acúmulo Cardíaco de Comporta/métodos , Hipertensão , Hipertensão , Hipertrofia Ventricular Esquerda/fisiopatologia , Hipertrofia Ventricular Esquerda , Hipertrofia Ventricular EsquerdaRESUMO
In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1%) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2%, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5% and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected (Au)
Assuntos
Humanos , Masculino , Feminino , Estudo Comparativo , Exercício Físico/fisiologia , Hipertensão/fisiopatologia , Função Ventricular Esquerda , Adulto , Idoso , Diástole , Ecocardiografia , Teste de Esforço , Imagem do Acúmulo Cardíaco de Comporta/métodos , Hipertensão/diagnóstico por imagem , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/fisiopatologia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagemRESUMO
In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1%) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2%, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5% and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected.
Assuntos
Exercício Físico/fisiologia , Hipertensão/fisiopatologia , Função Ventricular Esquerda , Adulto , Idoso , Diástole , Ecocardiografia , Teste de Esforço , Feminino , Imagem do Acúmulo Cardíaco de Comporta/métodos , Humanos , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , SístoleRESUMO
In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1
) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2
, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5
and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected.