1,388 research outputs found
Cuantificación de insecticidas organoclorados en sangre
La cromatografía de gases fué empleada para el análisis de residuos de Insecticidas organoclorados de 195 muestras de sangre, divididas en 5 grupos de población con diferentes grados de exposición. El primer grupo: Grupo control con baja exposición está contaminado en el 100%con DDT total (DDT + DDE) con un promedio de 18 ppb (rango 3ppb - 69ppb), el 6% de las muestras contienen Lindano y el 8%Dieldrin. El segundo grupo: población urbana con baja exposición está contaminado en el 100% con DDT total con un promedio de 13.6 (rango 3ppb-69ppb), el 6% se halla contaminado con Lindano y el 10% con Dieldrin El tercer grupo: Floricultores se encuentra igualmente contaminado en el 100% con DDT total con un promedio de 18 ppb (Rango 3-28 ppb), el 10% de las muestras contienen Dieldrin y el 5% Heptacloro epóxido. El cuarto grupo: Aplicadores del Servicio de Erradicación de la Malaria todos presentan contaminación con DDT total con un promedio de 26 ppb (Rango 5-57 ppb), el 16% presenta contaminación con Dieldrin, el 8% está contaminado con heptacloro epóxido. El quinto grupo: Correspondiente al grupo de Formuladores está en su totalidad contaminado con DDT total con un promedio de 35 ppb (rango 6-91 ppb), el 14% está contaminado con Lindano, el 6% con Aldrin, el 94% con Dieldrin con un promedio de 8.5 ppb, el 35% se halla contaminado con heptacloro epóxido. Los valores reportados son representativos y el grado de contaminación puede considerarse igual o menor si se compara con la de otros paises.Gas chromatography analysis for organochlorine insecticides was performed in 195 blood samples from individuals belonging to 5 groups according to levels of exposure: a) control group with low exposure; b) city dwellers; c) workers in greenhouse floriculture; d) workers doing spraying for malaria control; e) workers mixing insecticides. All the samples had DDT which was expressed as total DDT (DDT + DDE). For the five groups these values were (mean and Range in ppb): a) 18 (3-69); b) 13.6 (3-69); C) 18(3-28); d) 26 (5-57); e) 35 (6-91). Lindane was found in 6% a, 10%b, 14% e. Dieldrin in 8% a, 10%b, 10% e, 16% d and 94%-(mean 8.5 ppb) e. Heptachloride epoxide 5%e, 8% d and 35% e. The reported measurements are representative and the level of contamination can be considered equal to or lower than that reported in otrher countries
Ausencia de un efecto estructural molecular sobre las propiedades termodinámicas de varios materiales tipo biodiesel
In the search to develop the production of vegetable oils for non-food purposes biodiesel stands out for its great versatility as technical material and a cleaner energy technology. Physic nut (Jatropha curcas), castor-oil (Ricinus communis), oil palm (Elaeis guineensis), wine palm (Attalea butyracea) and macaw palm (Acrocomia aculeata) were chosen for study in our laboratory, because they are oleaginous plants with convenient oil yields to produce biodiesel. No significant effect from the nature of fatty-acid chains in biodiesel is observed on thermodynamic properties such as heat of combustion, cubic-expansion thermal coefficient, isothermal compressibility, enthalpy of vaporisation and Hildebrand solubility parameter. Activation energies for viscous flow of biodiesels correlates with the same property of their vegetable oil feedstocks.En la búsqueda de desarrollar la producción de aceites vegetales para fines no alimenticios, el biodiesel se destaca por su gran versatilidad como material técnico y como una tecnología de energía más limpia. Tempate (Jatropha curcas), higuerilla (Ricinus communis), palma aceitera (Elaeis guineensis), palma real (Attalea butyracea) y coyol (Acrocomia aculeata) fueron elegidos para su estudio en nuestro laboratorio, porque son plantas oleaginosas con rendimientos convenientes para producir biodiesel. No se observa ningún efecto significativo de la naturaleza de las cadenas de ácidos grasos en el biodiesel sobre las propiedades termodinámicas como el calor de combustión, el coeficiente térmico de expansión cúbica, la compresibilidad isotérmica, la entalpía de vaporización y el parámetro de solubilidad de Hildebrand. Las energías de activación para el flujo viscoso de biodiesel se correlacionan con la misma propiedad de sus materias primas de aceite vegetal
Variedades mejoradas de soya para zonas productoras actuales y potenciales de Colombia.
En el artículo podemos encontrar un breve resumen sobre la soya, así mismo el mejoramiento genético de la soya en Colombia como la resistencia a enfermedades, a plagas, al estrés abiótico, al desgrane y al volcamiento, las variedades de soya desarrolladas por Corpoica y la adaptabilidad de las variedades de soya en Colombia en las diferentes regiones por ejemplo Orinoquia y Valle.Soya-Soja- Glycine ma
Isolation and characterization of salt-sensitive mutants of the moderate halophile Halomonas elongata and cloning of the ectoine synthesis genes
The moderate halophile Halomonas elongata Deustche Sommlung fur Mikroorganismen 3043 accumulated ectoine, hydroxyectoine, glutamate, and glutamine in response to osmotic stress (3 M NaCl). Two Tn1732-induced mutants, CHR62 and CHR63, that were severely affected in their salt tolerance were isolated. Mutant CHR62 could not grow above 0.75 M NaCl, and CHR63 did not grow above 1.5 M NaCl. These mutants did not synthesize ectoine but accumulated ectoine precursors, as shown by 13C NMR and mass spectroscopy. Mutant CHR62 accumulated low levels of diaminobutyric acid, and mutant CHR63 accumulated high concentrations of N-γ-acetyl-diaminobutyric acid. These results suggest that strain CHR62 could be defective in the gene for diaminobutyric acid acetyltransferase (ectB), and strain CHR63 could be defective in the gene for the ectoine synthase (ectC). Salt sensitivity of the mutants at 1.5-2.5 M NaCl could be partially corrected by cytoplasmic extracts of the wild-type strain, containing ectoine, and salt sensitivity of strain CHR62 could be partially repaired by the addition of extracts of strain CHR63, which contained N-γ-acetyldiaminobutyric acid. This is the first evidence for the role of N-γ-acetyldiaminobutyric acid as osmoprotectant. Finally, a cosmid from the H. elongata genomic library was isolated which complemented the Ect- phenotype of both mutants, indicating that it carried at least the genes ectB and ectC of the biosynthetic pathway of ectoin
Chapter 4.The oceanographic and climatic context
The Alboran Sea is the westernmost basin of the Mediterranean Sea. It is the first one receiving the Atlantic waters flowing through the Strait of Gibraltar and the last one crossed by Mediterranean waters on their way out to the Atlantic Ocean. Therefore, the main factor that determines the Alboran Sea circulation and its water mass distribution is the Atlantic–Mediterranean exchange forced by climatic conditions within the Mediterranean Sea and the Strait of Gibraltar geometry. This general circulation exhibits very strong energetic dynamics with the alternation of cyclonic and anticyclonic circulation cells.
The Alboran Sea circulation is highly variable in time at different scales. Some of the shortest ones are semidiurnal and diurnal, associated to the tidal dynamics. The sub-inertial time scale is mainly linked to the wind and atmospheric pressure field variability, and affects the main circulation patterns of the Alboran Sea. Seasonal variability and long-term changes associated with decadal or even longer term changes are caused by alterations in the heat and freshwater fluxes between the Mediterranean Sea, the atmosphere, the nearby Atlantic Ocean and the river basins on land. These changes directly affect the temperature and salinity of the water masses within the Alboran Sea, while it is difficult to predict how they could affect their circulation and dynamics. In this chapter, some of the observed trends in the Alboran Sea water masses are presented. These changes include temperature and salinity increases of the water column, very likely caused by the current climate change process.En prens
Increased levels of hexacosanoic acid in the brain of Wistar rats: a behavioral study
Introduction: X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal metabolic disorder associated with mutations in the ATP-binding cassette sub-family D member1 (ABCD1) gene. Practically all male patients with X-ALD develop adrenocortical insufficiency during childhood and progressive myelopathy and peripheral neuropathy in adulthood. However, some male patients develop a fatal cerebral demyelinating disease named cerebral adrenoleukodystrophy. Although the exact mechanisms underlying brain damage in X-ALD are still poorly elucidated, it is known that hexacosanoic acid (C26:0) accumulation represents a hallmark in the pathogenesis of this disease. In this study, we examined whether an overload of C26:0 injected in Wistar rats was capable of causing behavioral changes in these animals.Methods: Egg lecithin in ethanol was dried under a nitrogen stream and mixed with C26:0 methyl ester. Male Wistar rats at 2–3 weeks of age were obtained from Universidade Federal do Rio Grande do Sul (UFRGS), divided into 8 groups, and submitted to an open field test. We then analyzed line crossings (locomotion and exploration), rearing (orienting and investigatory responses), grooming (anxiety manifestation), and latency to move for each animal.Results: Animals subjected to C26:0 administration presented fewer crossings and rearing episodes and a higher latency to move 45 minutes after C26:0 injection. The present work yields experimental evidence that C26:0, the main accumulated metabolite in X-ALD, can cause behavioral alterations in rats such as the impairment of locomotion and exploratory capabilities, as well as a reduction in orienting and investigatory responses.Conclusion: Although our results are preliminary, they are extremely important for future studies that investigate C26:0 accumulation and locomotor impairment in patients with X-ALD
Investigação de erros inatos do metabolismo
Inborn errors of metabolism are inherited metabolic disorders individually rare, but, taken together, their overall frequence is about 1 case out of 1000 newborns. The present study aimed to describe the main clinical features, as well as the general principles of investigation for these diseases. They were divided into two categories, one of the small molecules (aminoacidopathies, organic acidemias, etc) and the other of the complex molecules (lisossomal storage disorders, peroxisomal disorders, etc). Some of the most frequent groups of inborn errors of metabolism such as the aminoacidopathies, the organic acidemias and the mucopolissacharidosis, were discussed in detail.Os erros inatos do metabolismo são doenças metabólicas hereditárias individualmente raras, mas que em seu conjunto apresentam uma incidência aproximada de pelo menos 1 caso para cada mil nascimentos. O presente trabalho teve por objetivos descrever as principais manifestações clínicas, bem como os protocolos gerais de investigação diagnóstica para a maioria destes distúrbios. Para fins práticos, estas doenças foram divididas em duas categorias: das moléculas pequenas (aminoacidopatias, acideias orgânicas, etc) e das moléculas complexas (doenças lisossômicas de depósito, doenças peroxissomais, etc). Alguns grupos mais prevalentes de erros inatos do metabolismo, tais como as aminoacidopatias, as acidemias orgânicas e as mucopolissacaridoses, foram discutidos com maior ênfase
Updating temperature and salinity mean values and trends in the Western Mediterranean: the RADMED project
Postprin
Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea
The warming of the surface ocean is expected to increase the stratification of the upper water column. This would decrease the efficiency of the wind-induced mixing, reducing the nutrient supply to the euphotic layer and the productivity of the oceans. Climatic projections show that the Mediterranean Sea will experience a strong warming and salting along the twenty first century. Nevertheless, very few works have found and quantified changes in the water column stratification of the Western Mediterranean. In this work, we obtain time series of Mixed Layer Depth (MLD) along the Spanish Mediterranean waters and the Gulf of Cádiz, using periodic CTD profiles collected under the umbrella of the Ocean Observing system of the Instituto Español de Oceanografía (IEO-CSIC). The length of the time series analyzed is variable, depending on the geographical area, but in some cases these time series extend from the beginning of the 1990s decade. Our results show that at present, no statistically significant changes can be detected. These results are confirmed by the analysis of MLD time series obtained from Argo profilers. Some of the meteorological factors that could affect the water column stratification (wind intensity and precipitation rates) did not experience significant changes for the 1990-2021 period, neither were observed long-term changes in the chlorophyll concentration. The hypothesis proposed to explain this lack of trends, is that the salinity increase of the surface waters has compensated for the warming, and consequently, the density of the upper layer of the Western Mediterranean (WMED) has remained constant. As the wind intensity has not experienced significant trends, the stratification of the Spanish Mediterranean waters and those of the Gulf of Cádiz would have not been affected. Nevertheless, we do not discard that our results are a consequence of the short length of the available time series and the large variance of the variables analyzed, evidencing the importance of the maintenance of the ocean monitoring programs.En prens
Globotriaosylceramide is correlated with oxidative stress and inflammation in Fabry patients treated with enzyme replacement therapy
AbstractFabry disease is an X-linked inborn error of glycosphingolipid catabolism due to deficient activity of α-galactosidase A that leads to accumulation of the enzyme substrates, mainly globotriaosylceramide (Gb3), in body fluids and lysosomes of many cell types. Some pathophysiology hypotheses are intimately linked to reactive species production and inflammation, but until this moment there is no in vivo study about it. Hence, the aim of this study was to investigate oxidative stress parameters, pro-inflammatory cytokines and Gb3 levels in Fabry patients under treatment with enzyme replacement therapy (ERT) and finally to establish a possible relation between them. We analyzed urine and blood samples of patients under ERT (n=14) and healthy age-matched controls (n=14). Patients presented decreased levels of antioxidant defenses, assessed by reduced glutathione (GSH), glutathione peroxidase (GPx) activity and increased superoxide dismutase/catalase (SOD/CAT) ratio in erythrocytes. Concerning to the damage to biomolecules (lipids and proteins), we found that plasma levels of malondialdehyde (MDA) and protein carbonyl groups and di-tyrosine (di-Tyr) in urine were increased in patients. The pro-inflammatory cytokines IL-6 and TNF-α were also increased in patients. Urinary Gb3 levels were positively correlated with the plasma levels of IL-6, carbonyl groups and MDA. IL-6 levels were directly correlated with di-Tyr and inversely correlated with GPx activity. This data suggest that pro-inflammatory and pro-oxidant states occur, are correlated and seem to be induced by Gb3 in Fabry patients
- …