Metals contents in two fishes of different feeding behaviour in the Lower Paraná River and Río de la Plata Estuary

Cd, Cr, Cu and Pb concentrations were measured in the water and these plus Zn were measured in the diet, muscle and liver of the detritivorous fish Prochilodus lineatus and the omnivorous fish Pterodoras granulosus at two sites (Lower Paraná River and Río de la Plata right margin) located upstream and downstream, respectively, from Buenos Aires, an important source of xenobiotics. Cu and Cr concentrations in water were higher in the Río de la Plata coastal waters, while Cd and Pb were below detection limits. The stomach contents of P. lineatus showed a higher metal content at the estuary, attaining concentrations within the range reported for contaminated sediments. However, metals in fish tissue were not higher at the estuary and, except for Cd in liver, were lower than in the organic fraction of the stomach content. Thus, only Cd was accumulated. The P. granulosus diet was composed mainly of river vegetation debris and clams, Corbicula fluminea, at the estuary. Cd, Cu and Pb in liver were higher at the estuary while only Cu was higher in the diet at this site. The different nature of the diet seems associated with a differential bioavailability of its metal content. P. granulosus accumulates Cu at both sites and Cd at the estuary. Both fishes showed higher metal content in liver than in muscle. Cr in liver was below detection limits. No relation was found between metal content and fish size. Overall, metal content in fish tissues were low, except for Cu in P. granulosus and Cd in P. lineatus, similar to those of uncontaminated sites, suggesting that homeostatic mechanisms prevent metal accumulation.     

Recombinant Newcastle Disease Virus as a Vaccine Vector

A complete cDNA clone of the Newcastle disease virus (NDV) vaccine strain Hitchner B1 was constructed, and infectious recombinant virus expressing an influenza virus hemagglutinin was generated by reverse genetics. The rescued virus induces a strong humoral antibody response against influenza virus and provides complete protection against a lethal dose of influenza virus challenge in mice, demonstrating the potential of recombinant NDV as a vaccine vector.     

Developing a Social Autopsy Tool for Dengue Mortality: A Pilot Study

BackgroundDengue fever is a public health problem in the tropical and sub-tropical world. Dengue cases have grown dramatically in recent years as well as dengue mortality. Colombia has experienced periodic dengue outbreaks with numerous dengue related-deaths, where the Santander department has been particularly affected. Although social determinants of health (SDH) shape health outcomes, including mortality, it is not yet understood how these affect dengue mortality. The aim of this pilot study was to develop and pre-test a social autopsy (SA) tool for dengue mortality.ConclusionsThe SA tool is based on the scientific literature, a validated conceptual framework, researchers’ and health professionals’ expertise, and a pilot study. It is the first time that a SA tool has been created for the dengue mortality context. Our work furthers the study on SDH and how these are applied to neglected tropical diseases, like dengue. This tool could be integrated in surveillance systems to provide complementary information on the modifiable and avoidable death-related factors and therefore, be able to formulate interventions for dengue mortality reduction.     

Mapping of the mouse 86-kDa heat-shock protein expressed gene (Hsp86-1) on chromosome 12 and related genes on chromosomes 3, 4, 9, and 11

The HSP86 gene family in BALB/c, AKR/J, C58/J, and NFS/N inbred mice comprises an intron-containing expressed gene and, depending on the strain, two to four other HSP86-related members that are apparently processed pseudogenes. The expressed gene locus, Hsp86-1, was identified by its sequence identity with the mouse HSP86 cDNA coding region together with the presence of an intron at the same position as in the homologous human gene. Hsp86-1 was mapped 11.6 cM from the immunoglobulin heavy chain gene IgH on Chromosome 12 using an intersubspecies backcross. Two of the other loci that were common to all inbred strains tested, designated Hsp86-ps1 and Hsp86-ps2, were mapped to positions on Chromosomes 11 and 3, respectively. An HSP86-related locus specific to NFS/N and C58/J mice, designated Hsp86-ps3, was mapped on Chromosome 9. Also, an HSP86-related locus that was unique to NFS/N mice, designated Hsp86-ps4, was mapped to Chromosome 4.     

Comparative studies on blood serum alpha-L-fucosidases from several mammalian species.

1. Peripheral blood serum alpha-L-fucosidases have been studied from various mammalian species: Sus scropha var domestica L. (pig), Capra hircus L. (goat), Bos taurus L. (bull, races Morucha and Charolais), Equus caballus L. (horse) and Equus asinus L. (donkey). 2. Fluorimetric and spectrophotometric procedures were used for determination of alpha-L-fucosidases. 3. alpha-L-Fucosidases were more active towards fluorescent substrates than towards chromogenic substrates. 4. pH optima values of the enzymes are: (A) 5.5 for sera from all above-mentioned species when fluorescent substrates were employed; (B) 4.0 for goat, 4.5 for bull, 5.0 for pig and 4.5-5.0 for horse and donkey sera when chromogenic substrates were used. 5. pH activity profiles are very similar for two races (Morucha and Charolais) of the same species (Bos taurus L.) and also for two species of the same genus (Equus caballus and Equus asinus L.). 6. These serum alpha-L-fucosidases are very labile under heat treatment, even at 37 degrees C.     

Studies on the quaternary structure of class I major histocompatibility complex antigens. Effect of different agents on the interaction between subunits

The effect of temperature, urea, guanidine HCl, ionic and nonionic detergents, organic solvents, chaotropic salts, pH, and divalent cations has been investigated on purified human histocompatibility antigens solubilized by papain (HLApap) or solubilized by sodium cholate (HLAchol). HLApap and HLAchol are fairly stable proteins to agents acting predominantly on hydrogen bonds (temperature, urea) or hydrophobic forces (ionic and nonionic detergents). However, agents which affect ionic interactions (pH, salts, divalent cations) dissociate the molecules into subunits. A single binding site for beta 2-microglobulin with an affinity constant of 1.0 X 10(7) M-1 was found for the alpha chain of HLAchol. The dissociated subunits can be separated by affinity chromatography on Sepharose-rabbit IgG anti-human beta 2-microglobulin and reassociate in vitro when incubated under the appropriate conditions. The results point toward an important role of ionic interactions between subunits in the stabilization of the quaternary structure of HLA.     

NPY- and CGRP-like immunoreactive nerve fibers in the testis and mesorchium of the toad (Bufo arenarum)

The presence and distribution of peptidergic nerve fibers were studied in the testis and mesorchium of the toad by means of immunohistochemistry. Cryostat sections of the testis and whole-mount preparations of mesorchia were immunostained with antisera to calcitonin gene-related peptide (CGRP) and neuropeptide tyrosine (NPY). After leaving the mesorchium CGRP-immunoreactive (IR) fibers were seen predominantly running in between the seminiferous tubules. In addition, a small population of CGRP-IR nerve fibers formed thin plexuses around blood vessels. Conversely, NPY-like immunoreactivity predominated in nerve fibers that formed dense plexuses around vessels both in the mesorchium and testis. Additionally, some single NPY-IR nerve fibers could be seen in both structures studied. The functional significance of these peptidergic systems in the testis of the toad remains to be analyzed.     

Binding of [H][D-Ala, MePhe, Gly-ol] Enkephalin, [H][D-Pen, D-Pen]Enkephalin, and [H]U-69,593 to Airway and Pulmonary Tissues of Normal and Sensitized Rats

Bhargava, H. N., V. M. Villar, J. Cortijo and E. J. Morcillo. Binding of [³H][D-Ala², MePhe⁴, Gly-ol⁵]enkephalin, [³H][D-Pen², D-Pen⁵]enkephalin, and [³H]U-69,593 to airway and pulmonary tissues of normal and sensitized rats. Peptides 18(10) 1603–1608, 1997.—The role of endogenous opioid peptides in the regulation of bronchomotor tone, as well as in the pathophysiology of asthma is uncertain. We have studied the binding of highly selective [³H]labeled ligands of μ-([D-Ala², MePhe⁴, Gly-ol⁵]enkephalin; DAMGO), δ ([D-Pen², D-Pen⁵]enkephalin; DPDPE), and κ-(U-69,593) opioid receptors to membranes of trachea, main bronchus, lung parenchyma and pulmonary artery obtained from normal (unsensitized) and actively IgE-sensitized rats acutely challenged with the specific antigen. [³H]DAMGO, [³H]DPDPE and [³H]U-69,593 bound to membranes of normal and sensitized tissues at a saturable, single high-affinity site. The rank order of receptor densities in normal tissues was δ- ≥ κ- ≥ μ-, with lung parenchyma exhibiting the greatest binding capacity for δ- and μ- receptors compared to the other regions examined. The K_d values showed small differences between ligands and regions tested. The μ- and δ-opioid receptor densities were decreased in sensitized main bronchus and lung parenchyma, respectively, compared to normal tissues. By contrast, κ-opioid receptor density was augmented in sensitized lung parenchyma but an increase in K_d values was also observed. These differential changes in the density and affinity of opioid receptor types may be related to alterations in endogenous opioid peptides during the process of sensitization.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration of two <Emphasis Type="Italic">Populus</Emphasis> hybrid clones. The role of pectin domains in cell processes underlying shoot organogenesis induction

An efficient plant regeneration protocol has been established for two commercial Populus hybrid clones, MC (Populus × euramericana) and UNAL (Populus × interamericana). The culture of internode segments on Murashige and Skoog (MS) medium with 0.5 μM α-naphthalene acetic acid (NAA) and 4 μM N⁶-benzyladenine for 7 weeks (2 weeks in absence of activated charcoal and 5 weeks in its presence) resulted in the highest frequency of shoot regeneration (100 % for MC and 82 % for UNAL). All regenerated shoots longer than 2 cm rooted on half-strength MS medium, independent of the addition of 0.1 μM NAA. Nevertheless, shoots developed better-formed roots in NAA-free medium, which had a positive effect on the acclimatization of plants. In order to know the cellular processes underlying in vitro shoot organogenesis, a histological study was made in UNAL internode-explants. Results revealed that in vitro culture caused swelling around the cut-off zones in all explants, but only those undergoing organogenesis formed proliferation centers under subepidermal cells, which led to formation of bud primordia. Moreover, in vivo tissues and explants with different in vitro response showed different immunolabelling patterns when they were treated with fluorescentmonoclonal antibodies directed to several pectin-polysaccharides of the cell wall. Results allow us to assign a predominant role of homogalacturonan with a low degree of methyl-esterification in the initiation of bud primordia, a role of β-1,4-D-galactan side chains of rhamnogalacturonan-I in the cellular differentiation, ra ole of α-1,5-L-arabinan side chains of rhamnogalacturonan-I and of homogalacturonan with a high degree of methyl-esterification in cell division and growth.