SEROPOSITIVITY FOR ASCARIOSIS AND TOXOCARIOSIS AND CYTOKINE EXPRESSION AMONG THE INDIGENOUS PEOPLE IN THE VENEZUELAN DELTA REGION

The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.     

Acute toxicity of chlorpyrifos to the non-target organism Cnesterodon decemmaculatus

Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC₅₀ of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment.     

Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 10¹³ to 10⁵ Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods.     

Complete maternal uniparental isodisomy of chromosome 4 in a subject with major depressive disorder detected by high density SNP genotyping arrays.

Uniparental isodisomy (iUPD) is a rare genetic condition caused by non-disjunction during meiosis that ultimately leads to a duplication of either the maternal or paternal chromosome in the affected individual. Two types of disorders can result, those due to imprinted genes and those due to homozygosity of recessive disease-causing mutations. Here, we describe the third known case of complete chromosome 4 iUPD of maternal origin. This condition became apparent during whole genome linkage studies of psychiatric disorders in the Portuguese population. The proband is an adult female with normal fertility and no major medical complaints, but a history of major depressive disorder and multiple suicide attempts. The proband's siblings and parents had normal chromosome 4 genotypes and no history of mood disturbance. A brief review of other studies lends support for the possibility that genes on chromosome 4 might confer risk for mood disorders. We conclude that chromosome 4 maternal uniparental disomy (UPD) is a rare disorder that may present with a major depressive phenotype. The lack of a common disease phenotype between this and two other cases of chromosome 4 iUPD [Lindenbaum et al. [1991] Am J Med Genet 49(Suppl 285):1582; Spena et al. [2004] Eur J Hum Genet 12:891-898) would suggest that there is no vital maternal gene imprinting on chromosome 4. However, since there is no reported case of paternal chromosome 4 UPD, paternal gene imprinting on chromosome 4 cannot be excluded.     

Left pulmonary artery evaluation through transesophageal echocardiography.

INTRODUCTION: Transesophageal echocardiography (TEE) has become increasingly useful in the study of patients with suspected pulmonary thromboembolism. OBJECTIVE: The aim of this study was to prospectively evaluate the usefulness of TEE in the study of the distal part of the left pulmonary artery (LPA) as well as the influence of this procedure on total echocardiographic exam duration. METHODOLOGY: A prospective study in two groups of consecutive patients referred for TEE with a one- year interval between evaluation of Group A: 33 patients, 17 male, mean age 54 +/- 24 years, and Group B: 42 patients, 20 male, mean age 48 +/- 27 years (p = NS). The procedure was considered long when it took more than 3 min to evaluate the distal part of the LPA. RESULTS: In group A we were able to visualize the distal part of the LPA in 24 patients (73%) without significant prolongation of total exam duration in 16 patients (48% of group A). In one of the patients with suspected pulmonary thromboembolism thrombi were only observed in the distal part of the LPA. In group B we were able to visualize the distal part of the LPA in 36 patients (86%) without significant prolongation of total exam duration in 26 patients (61% of group B). CONCLUSIONS: 1. Visualization of the distal part of the LPA was possible in more patients, and with TEE time prolongation in less patients, in group B. These differences can be accounted for by the training of the operator in this technique. 2. The importance of visualization of this part of the LPA in guiding treatment in the subset of patients with pulmonary thromboembolism confirms the usefulness of this specific procedure.     

Direct effect of acute metabolic and respiratory acidosis on parathyroid hormone secretion in the dog.

Because both metabolic (Met Acid) and respiratory acidosis (Resp Acid) have diverse effects on mineral metabolism, it has been difficult to establish whether acidosis directly affects parathyroid hormone (PTH) secretion. Our goal was to determine whether acute Met Acid and Resp Acid directly affected PTH secretion. Three groups of dogs were studied: control, acute Met Acid induced by HCl infusion, and acute Resp Acid induced by hypoventilation. EDTA was infused to prevent acidosis-induced increases in ionized calcium, but more EDTA was needed in Met Acid than in Resp Acid. The PTH response to EDTA-induced hypocalcemia was evaluated also. Magnesium needed to be infused in groups receiving EDTA to prevent hypomagnesemia. The half-life of intact PTH (iPTH) was determined during hypocalcemia when PTH was measured after parathyroidectomy. During normocalcemia, PTH values were greater (p < 0.05) in Met Acid (92 +/- 19 pg/ml) and Resp Acid (77 +/- 22 pg/ml) than in controls (27 +/- 5 pg/ml); the respective pH values were 7.23 +/- 0.01, 7.24 +/- 0.01, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was greater (p < 0.05) in Met Acid (443 +/- 54 pg/ml) than in Resp Acid (267 +/- 37 pg/ml) and controls (262 +/- 48 pg/ml). The half-life of PTH was greater (p < 0.05) in Met Acid than in controls, but the PTH secretion rate also was greater (p < 0.05) in Met Acid than in the other two groups. In conclusion, (1) both acute Met Acid and Resp Acid increase PTH secretion when the ionized calcium concentration is normal; (2) acute Met Acid may increase the bone efflux of calcium more than Resp Acid; (3) acute Met Acid acts as a secretogogue for PTH secretion because it enhances the maximal PTH response to hypocalcemia.