Rapid analysis of persistent organic pollutants by solid phase microextraction in serum samples.

A simple and rapid headspace solid-phase microextraction (HS SPME) based method is presented for the determination of Persistent Organic Pollutants (POPs) in human serum by gas chromatography (GC) coupled to mass detector (MS) with electron impact ionization (EI). As an outcome of the assessment of several polymer phases; the one with the best result was the PDMS fiber (100 µm). A multivariate analysis of variance by permutations (PERMANOVA) was performed to establish the optimal extraction conditions as a function of temperature and time variables. The results were 1 mL serum+200 µL H2SO4 9M+1 mL of deionized water at 600 rpm with a temperature of 80°C for 50 min to expose the fiber. The limits of detection (LOD) for POPs pesticides fell within the 0.22-5.41 ng/mL interval, and within 0.07-1.79 ng/mL for PCBs; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (15 ng/mL) were 67.8-120.2%, and at high concentrations (75 ng/mL) 80.2-119.2%. Evaluated precision as percentage Relative Standard Deviation (RSD%) of repeatability and reproducibility was within a range of 0.5-9% and 0.3-21%, respectively. This analytical method prevents some of the main problems for quantifying POPs in human serum, such as the elimination of the solvents, sample handling, integration of extraction steps, pre-concentration and introduction of samples; consequently, the time and cost of analyzing the sample can be significantly reduced. The method developed was applied to determine exposure to POPs in samples of children living in different polluted sites in Mexico. In children living in indigenous communities results show exposure to DDE (median 29.2 ng/mL range 17.4-52.2 ng/mL) and HCB (median 2.53 ng/mL range 2.50-2.64 ng/mL); whereas in the industrial scenario, exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (median Σ-PCBs 22.2 ng/ml range 8.2-74.6 ng/mL) and finally in petrochemical scenario was demonstrated exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (Σ-PCBs median 7.9 ng/mL range 5.4-114.5 ng/mL).

Arsenic and fluoride co-exposure affects the expression of apoptotic and inflammatory genes and proteins in mononuclear cells from children.

Humans may be exposed to arsenic (As) and fluoride (F) through water consumption. However, the interaction between these two elements and gene expression in apoptosis or inflammatory processes in children has not been thoroughly investigated. Herein, the expression of cIAP-1, XIAP, TNF-α, ENA-78, survivin, CD25, and CD40 was evaluated by RT-PCR. Additionally, the surface expression of CD25, CD40, and CD40L on peripheral blood mononuclear cells was analyzed by flow cytometry, and TNF-α was measured by Western blotting. This study examined 72 children aged 6-12 years who were chronically exposed to As (154.2µg/L) and F (5.3mg/L) in drinking water and in food cooked with the same water. The urine concentrations of As (6.9-122.4µg/L) were positively correlated with the urine concentrations of F (1.0-8.8mg/L) (r(2)=0.413, p<0.0001). The CD25 gene expression levels and urine concentrations of As and F were negatively correlated, though the CD40 expression levels were negatively correlated only with the As concentration. Age and height influenced the expression of cIAP-1, whereas XIAP expression was correlated only with age. Additionally, there was a lower percentage of CD25- and CD40-positive cells in the group of 6- to 8-year-old children exposed to the highest concentrations of both As and F when compared to the 9- to 12-year-old group (CD25: 0.7±0.8 vs. 1.1±0.9, p<0.0014; CD40: 16.0±7.0 vs. 21.8±5.8, p<0.0003). PHA-stimulated lymphocytes did not show any changes in the induction of CD25, CD69, or CD95. In summary, high concentrations of As and F alter the expression patterns of CD25 and CD40 at both the genetic and protein levels. These changes could decrease immune responses in children exposed to As and F.

Development and validation of an analytical method to determine Fipronil and its degradation products in soil samples.

The aim of this study was to develop a methodology for identifying and quantifying Fipronil and its degradation products in soil by gas chromatography-electron capture detector previously extracted using a focused ultrasound probe. This methodology was obtaining a range of recovery between 85% and 120%, decreasing approximately solvent used time and cost, respect to other methodologies such as bath ultrasonic, solid-phase extraction, liquid-liquid extraction and soxhlet. The method was validated in fortified matrix, presented linearity in the range of 25-400 µg kg(-1), and limit of detection for Fipronil and their products desulfinyl, sulfide and sulfone was 14.7, 9.8, 8.9 and 10.7 µg kg(-1), respectively. This process was applied to samples of agricultural soils, where two degradation products desulfinyl and sulfone were found.

Effect of arsenic on regulatory T cells.

INTRODUCTION: Arsenic (As) affects the function and survival of lymphocytes, and some arsenic compounds exert a relevant antineoplastic effect. We have explored the effect of As on T regulatory cells. RESULTS AND DISCUSSION: In vitro experiments with peripheral blood mononuclear cells from healthy subjects showed that low concentrations of As tended to increase the number of natural T regulatory (nTreg) lymphocytes, whereas concentrations >5.0 muM had an opposite effect. Furthermore, rats exposed to As showed redistribution of nTreg cells, and As administration to rats with experimental allergic encephalomyelitis increased the levels of nTreg cells in spleen and diminished the severity of this condition. On the other hand, in 47 apparently healthy subjects chronically exposed to As, we found significant inverse correlation between urinary As levels and the number and function of nTreg lymphocytes. Although most of these individuals showed enhanced levels of apoptotic lymphocytes in peripheral blood, with a diminution of mitochondrial membrane potential, no significant correlation between these parameters and urinary As was detected. CONCLUSION: Our data indicate that As seems to have a relevant and complex effect on nTreg cells.

Convulsiones afebriles asociadas con rotavirus / Afebrile convulsions associated to rotavirus

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Estudio de la Osteoporosis en un grupo de pacientes geriátricos

Se presenta un estudio en 42 pacientes geriátricos ingresados en el servicio de Geriatría del Hospital Docente Clínico Quirúrgico "10 de Octubre" en Ciudad de la Habana en el período comprendido entre enero de 1989 y enero de 90, con el fin de conocer la frecuencia de osteoporosis en la población geriátrica. Se le brinda en la introducción una breve reseña de las características principales de la enfermedad, así como sus manifestaciones clínicas. El trabajo se ejecutó sobre 42 pacientes, los cuales se clasificaron según grupos de edades, sexo, motivo de ingreso, hábitos tóxicos y nutricionales y actividad física. Se presentaron las manifestaciones clínicas de los pacientes, las investigaciones a que fueron sometidos y sus alteraciones radiológicas. Se analiza la frecuencia de la osteoporosis y sus tipos . Todos estos resultados se muestran en las tablas y los mismos se comparan con los resultados obtenidos por otros autores. Se brindan las conclusiones a que dan lugar estos resultados, así como las recomendaciones que se derivan de las mismas.(AU)

Estudio de la Osteoporosis en un grupo de pacientes geriátricos

Se presenta un estudio en 42 pacientes geriátricos ingresados en el servicio de Geriatría del Hospital Docente Clínico Quirúrgico "10 de Octubre" en Ciudad de la Habana en el período comprendido entre enero de 1989 y enero de 90, con el fin de conocer la frecuencia de osteoporosis en la población geriátrica. Se le brinda en la introducción una breve reseña de las características principales de la enfermedad, así como sus manifestaciones clínicas. El trabajo se ejecutó sobre 42 pacientes, los cuales se clasificaron según grupos de edades, sexo, motivo de ingreso, hábitos tóxicos y nutricionales y actividad física. Se presentaron las manifestaciones clínicas de los pacientes, las investigaciones a que fueron sometidos y sus alteraciones radiológicas. Se analiza la frecuencia de la osteoporosis y sus tipos. Todos estos resultados se muestran en las tablas y los mismos se comparan con los resultados obtenidos por otros autores. Se brindan las conclusiones a que dan lugar estos resultados, así como las recomendaciones que se derivan de las mismas.(AU)