RESUMO
Airborne particulate matter is a serious threat to human health, especially in fast-growing cities. In this study, we carried out a magnetic and elemental study on tree leaves used as passive captors and urban dust from various sites in the city of Santiago, Chile, to assess the reliability of magnetic and elemental measurements to characterize particulate matter pollution from vehicular origin. We found that the magnetic susceptibility and saturation isothermal remanent magnetization measured on urban tree leaves is a good proxy for tracing anthropogenic metallic particles and allow controlling the exposure time for particulate matter collection, in agreement with other studies carried out in large cities. Similar measurements on urban soil can be influenced by particles of detritic (natural) origin, and therefore, magnetic measurements on tree leaves can help to identify hotspots where fine particles are more abundant. Elemental particle-induced X-ray emission analysis of tree leaves showed the presence of a number of elements associated with vehicular emissions, in particular Cu, Zn, Fe, K and S which are present at every site, and As, Se, V, Ni, Sr, Zr, Mo and Pb identified at some sites. We observed a correlation between magnetic parameters and the concentrations of S and Br as well as Cu to a smaller extent. Moreover, this study shows the importance of selecting carefully the tree species as well as the location of trees in order to optimize phytoremediation.
Assuntos
Poluentes Atmosféricos , Material Particulado , Humanos , Material Particulado/análise , Árvores , Poluentes Atmosféricos/análise , Chile , Reprodutibilidade dos Testes , Monitoramento Ambiental , Folhas de Planta/química , Cidades , Fenômenos MagnéticosRESUMO
Introducción. El Tecnecio-99m (99mTc) es el radioisótopo más utilizado en medicina nuclear. Su uso en diagnóstico permite visualizar imágenes de estructuras anatómicas y brindar información sobre distintas funciones orgánicas. La gran demanda de este radionucleído se debe a sus favorables propiedades nucleares, a la gran cantidad de compuestos que se pueden marcar con él y al hecho de poder contar con generadores de 99mTc, lo que posibilita su obtención en lugares alejados de los centros de producción. Un generador de radioisótopos es un sistema mediante el cual un radionucleído padre genera por decaimiento radiactivo un radionucleído hijo de vida media más corta que la del padre. En el caso del generador de 99mTc, el radionucleído padre es el Molibdeno-99 (99Mo) cuya vida media es de 66 horas, mientras el radionucleído hijo, el 99mTc, tiene una vida media de 6 horas. Objetivo. La Comisión Chilena de Energía Nuclear (CCHEN) a través del Laboratorio de Producción de Radioisótopos realiza diariamente una producción de 99mTc, la cual entrega a Centros de Medicina Nuclear de la Región Metropolitana. Siin embargo, debido al método por el cual se obtiene, no es posible abastecer a los Centros de Medicina Nuclear de provincias. Conciente de esta necesidad, la CCHEN ha decidido poner en marcha el proyecto de fabricación de generadores de 99Mo - 99mTc, con lo cual nos situaremos en un breve plazo dentro del contexto de países que ya poseen esta tecnología. Materiales y Método. El método de fabricación se basa en la adsorción selectiva del 99Mo en óxido de aluminio (Al2O3 ), mientras el 99mTc que se genera por decaimiento radiactivo del 99Mo y que está débilmente unido a la alúmina, se puede eluir diariamente. Este tipo de generador es simple de operar y está diseñado en un sistema cerrado que permite mantener la esterilidad y proporcionar un producto de alta pureza. Resultados y Conclusión. La preparación de la alúmina, el acondicionamiento del Mo y las característica...
Assuntos
Geradores de Radionuclídeos , Preparações Farmacêuticas , Compostos Radiofarmacêuticos , Tecnécio , Tecnologia Farmacêutica , Chile , Molibdênio , Radioisótopos , Óxido de AlumínioRESUMO
La patogenia de la infecciones del pie diabético involucra la polineuropatía, la enfermedad macro y microvascular y el déficit funcional de los neutrófilos. La vasodilatación dependiente del endotelio, relacionada con el Oxido Nítrico (NO), está comprometida en diabéticos predispuestos a ulceración del pie. El NO, es producido también por neutrófilos y macrófagos estimulados por citoquinas o lipopolisacáridos bacterianos mediante la sintetasa de NO inducible (iNOS), ejerciendo actividad microbicida. La peroxidación lipídica reflejada por la producción de malondialdehido (MDA), está implicada en el desarrollo de microangiopatía diabética. Para comparar los niveles séricos de NO y MDA en pacientes con pie diabético con o sin infección, se estudiaron 27 individuos diabéticos tipo 2 con edades entre 38 y 65 años divididos en 3 grupos: 8 controles sin afección de los pies (A), 10 con pie diabético sin infección (B) y 9 con pie diabético infectado (C). El NO fué determinado mediante ensayo de diazotización y el MDA mediante la relación de Acido Thiobarbitúrico. B y C mostraron niveles de NO menores (p= 7.636 x 10-5 y p= 0,006) que A. El NO fue mayor en el grupo infectado que en el grupo sin infección (p=0,05), sin embargo los valores obtenidos no coinciden con lo esperado teniendo en cuenta las grandes cantidades de NO producido mediante iNOS, sugiriendo un defecto más del leucocito del diabético. No hubo diferencia significativa en el MDA entre los grupos, indicando ausencia de stress oxidativo relevante
Assuntos
Humanos , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Infecções , Malondialdeído , Biomarcadores , Óxido Nítrico , Pé Diabético/classificação , VenezuelaRESUMO
The role of prostaglandins (PGs) in hypertension (HT) is reviewed, emphasising their biochemical characteristics, physiological effects and functions, especially in the cardiovascular area, and the current evidence of their participation in the antihypertensive activity of a balanced mechanism to maintain normal blood pressure. Also, the clinical use of PGs and the future of such autacoids in the treatment of HT and other diseases or conditions is mentioned.
Assuntos
Hipertensão/metabolismo , Prostaglandinas/fisiologia , Animais , Autacoides/uso terapêutico , Biomarcadores , Pressão Sanguínea/fisiologia , Endotélio Vascular/metabolismo , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiopatologia , Receptores de Prostaglandina/metabolismo , Vasoconstrição/fisiologiaRESUMO
Nitrendipine (NIT), a new potent calcium channel blocking agent, was administered to a patient with essential severe (191/119 mm Hg), refractory, and resistant hypertension (HT) to conventional triple drug regime. Three previous pregnancies had been unsuccessful in the past 4 years because of uncontrollable HT and repeated hypertensive crises. NIT (20 mg tablets) was given PO as a single morning dose and 15 months after BP control, she became pregnant again. With a 20 mg/day dose of NIT throughout pregnancy, a healthy 2400 g, 47 cm male boy was delivered by a non-emergency cesarean section at 37 weeks' pregnancy. Both mother and son remain normal months after birth. The results suggest NIT may be considered as an alternative for this type of patients and should be studied in clinical trials.
Assuntos
Hipertensão/tratamento farmacológico , Nitrendipino/uso terapêutico , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Adulto , Feminino , Humanos , GravidezRESUMO
Doxazosin, a new quinazoline-derivative postsynaptic alpha 1-adrenoceptor antagonist, was studied in this randomized, double-blind, placebo-controlled 12-week study. Its effects on blood pressure (BP), heart rate, metabolic functions and renal hormones were analyzed after administration of a single oral morning dose in a 3-phase fashion when administered to 17 patients (11 women, 6 men, 21 to 59 years) with mild to moderate uncomplicated essential hypertension. After titrating the antihypertensive effective dose biweekly from 1 to 8 mg/day and a mean end titration-point dose of 4.14 +/- 0.1 mg (mean +/- standard error of the mean) at week 8 of treatment, it was adjusted to maintain diastolic BP at levels less than or equal to 90 mm Hg for up to 12 weeks of treatment when, at a final mean dose of 4.35 +/- 0.2 mg/day, BP decreased in all patients by a mean 31 +/- 3/17 +/- 2 (supine) and 39 +/- 3/15 +/- 3 (standing) mm Hg (p less than 0.005) with no increase in heart rate and no "first-dose phenomenon." Neither the renin-aldosterone system nor electrolyte excretion was significantly affected. Renal function and metabolic parameters also remained unchanged. Urinary kallikrein excretion was augmented 2.47-fold (p less than 0.002). There was good tolerance; 1 patient discontinued the study because of dry nose. These results suggest that long-term monotherapy with doxazosin is an effective and safe antihypertensive agent for mild to moderate essential hypertension that stimulates urinary kallikrein excretion.
Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Calicreínas/urina , Prazosina/análogos & derivados , Sistema Renina-Angiotensina/efeitos dos fármacos , Adulto , Anti-Hipertensivos/administração & dosagem , Método Duplo-Cego , Doxazossina , Esquema de Medicação , Feminino , Humanos , Calicreínas/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Natriurese/efeitos dos fármacos , Prazosina/administração & dosagem , Prazosina/uso terapêuticoRESUMO
The antihypertensive efficacy of once-daily nitrendipine was studied in 18 patients with severe, resistant, refractory, and complicated hypertension. The dose range was 20-120 mg/day adjusted weekly for a total treatment period of 3 years. Nitrendipine produced a significant reduction in blood pressure compared to pretreatment baseline values with no significant effects on heart rate. Renal function was preserved and there was an increase in urine flow, urinary excretions of Na+, kallikrein, and prostaglandin E2, and plasma renin. Some patients experienced known calcium antagonist side effects but the drug was otherwise well tolerated.