Follow-up of mercury levels in fish,human hair and urine in the Madeira and Tapajós basins,Amazon, Brazil

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994).     

Accumulation of metals in macrophytes from water reservoirs of a power supply plant, Rio de Janeiro State, Brazil

Aquatic macrophytes are well known accumulators for heavy metals, the reason why they are used as bioindicators for water quality and in phytoremediaton strategies. This study reports on the elemental concentrations in four free-floating aquatic macrophytes (S. auriculata; P. stratiotes; E. crassipes and E. azurea) growing in two water reservoirs (Santana e Vigário, Rio de Janeiro State, Brazil) of an electric power plant that receive input from the polluted Paraíba do Sul River. Filtered water samples and water suspended solids from these environments were also analysed. Inductively coupled plasma mass spectrometry was used as the principal method, allowing the determination of up to 41 elements, including the rare-earth elements (REEs) and other trace metals not assayed before in these macrophytes. The results show that all elements studied are accumulated by the macrophytes with concentration ratios (CR = [plant]: [water]) varying from about 1,000 to 200,000, based on the dry weight of the plant species. With a few exceptions, highest accumulations were observed in E. crassipes in which CRs increase in the sequence: Cu < Mo < Cr < Pb < Tl < Fe < La < Zn < Ce< Mn. Surprisingly high CRs (e.g. Ce: 74,000) and corresponding mass concentrations were observed for the rare-earth elements (e.g. ∑REE: 112 mg kg^?1), also measured in the water suspended particle fraction. The results show that this fraction acts as an effective sink for trace metals in the aquatic system studied and seems to play also an important role in the transfer of metals from water to the plant species.     

Preservation of cadavers for surgical technique training

OBJECTIVE: To evaluate a technique for preservation of organoleptic tissue characteristics (color, odor, texture, and flexibility) in cadavers used for surgical instruction. STUDY DESIGN: Experimental study. ANIMALS: Forty-three canine cadavers. METHODS: Cadavers were preserved with a modified Larssen solution of the Hospital Cochim, Paris and cryopreservation. Tissue handling qualities were evaluated in surgical laboratory sessions. RESULTS: All cadavers kept texture and tissues consistency, especially skin and muscle, similar to those of live animals. Some skin desquamation and pallor of the mucous membranes occurred with repetitive freeze-thaw cycles. CONCLUSIONS: This preservation technique provides acceptable cadaver quality and tissue handling for use in surgical instruction. CLINICAL RELEVANCE: Preparation of patient cadavers by intravascular injection of modified Larssen solution yielded suitable instructional models for surgical training.     

Characterization of extraintestinal Escherichia coli isolated from a peacock (Pavo cristatus) with colisepticemia

Extraintestinal infections by avian pathogenic strains of Escherichia coli (APEC) are commonly reported in poultry, but there is little information on infections by APEC in other bird species. Here we report on the characterization of extraintestinal E. coli isolated from a domesticated peacock, from the south of Brazil, that died of colisepticemia. Necropsy examination revealed congested liver, hypertrophied kidneys, peritonitis, severe typhlitis suggestive of coligranuloma, pneumonia, and airsacculitis--typical signs of colisepticemia. The isolates from lungs, kidney, heart, intestine, liver, and bone marrow all harbored the same virulence-associated factors (iucD, colV, iss, mat, fimC, ompA, traT crl, csgA vgrG, and hcp), yielded the same band pattern in amplified ribosomal DNA restriction analysis, and were allocated to the Escherichia coli Reference Collection group B1. The isolates were resistant to bacitracin, trimethoprim, and tetracycline, but displayed slight differences in their resistance to other antimicrobials. The isolates also differed in their virulence in 1-day-old chickens, but none displayed high virulence in vivo. We conclude that the peacock died of colisepticemia after it was infected with an extraintestinal E. coli strain of low virulence that nevertheless harbored virulence factors generally associated with APEC. This study represents the first characterization of an APEC isolated from a nonpoultry bird species.     

Muscle reorganisation through local injection of stem cells in the diaphragm of mdx mice

Background

The diaphragm is the major respiratory muscle affected by Duchenne muscular dystrophy (DMD) and is responsible for causing 80% of deaths. The use of mechanical forces that act on the body or intermittent pressure on the airways improves the quality of life of patients but does not prevent the progression of respiratory failure. Thus, diseases that require tissue repair, such as DMD, represent a group of pathologies that have great potential for cell therapy. The application of stem cells directly into the diaphragm instead of systemic application can reduce cell migration to other affected areas and increase the chances of muscle reorganisation. The mdx mouse is a suitable animal model for this research because its diaphragmatic phenotype is similar to human DMD. Therefore, the aim of this study was to assess the potential cell implantation in the diaphragm muscle after the xenotransplantation of stem cells.

Methods

A total of 9 mice, including 3 control BALB/Cmice, 3 5-month-old mdx mice without stem cell injections and 3 mdx mice injected with stem cells, were used. The animals injected with stem cells underwent laparoscopy so that stem cells from GFP-labelled rabbit olfactory epithelium could be locally injected into the diaphragm muscle. After 8 days, all animals were euthanised, and the diaphragm muscle was dissected and subjected to histological and immunohistochemical analyses.

Results

Both the fresh diaphragm tissue and immunohistochemical analyses showed immunopositive GFP labelling of some of the cells and immunonegativity of myoblast bundles. In the histological analysis, we observed a reduction in the inflammatory infiltrate as well as the presence of a few peripheral nuclei and myoblast bundles.

Conclusion

We were able to implant stem cells into the diaphragm via local injection, which promoted moderate muscle reorganisation. The presence of myoblast bundles cannot be attributed to stem cell incorporation because there was no immunopositive labelling in this structure. It is believed that the formation of the bundles may have been stimulated by cellular signalling mechanisms that have not yet been elucidated.     

Hematological and coagulation profiles in dogs experimentally infected with Angiostrongylus vasorum (Baillet, 1866).

Hematological and coagulation profiles were studied in crossbred dogs experimentally infected with Angiostrongylus vasorum. Two groups of five dogs were experimentally inoculated with 50 and 100 third stage infective larvae (L(3)) of A. vasorum per kilogram of body weight. A third group of five uninfected animals was used as control. One sample of 10 ml of blood was collected from each animal on the 10, 20, 30, and 45 days after inoculation (dai) and at 30-day intervals thereafter for the remainder of the 210-day experimental period. The blood sample was used for the complete hemogram and platelet count, as well as measurements of prothrombin time, partial thromboplastin time and factors V and VIII. Anemia was observed in infected dogs, 6 weeks after the infection. The eosinophils presented peaks in four periods after infection. Thrombocytopenia became accentuated on the 72 dai. Decreased prothrombin time activity and increased partial thromboplastin time were observed at the 6 and 9 weeks after infection and decreased of factors VIII and V activities occurred from 4 to 6 weeks after infection. It may be conclude that infection by A. vasorum in dogs may cause a discrete anemia during the acute phase which is probably regenerative. In addition, important hemostatic alterations due to the infection suggest a chronic intravascular consumption coagulopathy.     

Performance, growth, and maturity of Nellore bulls

The objectives of this study were to evaluate the dry matter intake (DMI), digestibility, average daily gain (ADG), microbial efficiency, empty body weight (EBW) gain, and body composition of Nellore bulls. Additionally, Nellore bull maturity was estimated, and the prediction equation for DMI, suggested by the Brazilian nutrient requirements system (BR CORTE; Azevêdo et al. 2010), was evaluated. Thirty-three Nellore bulls, with a mean initial weight of 259?±?25 kg and age of 14?±?1 months, were used in this study. Five animals were slaughtered at the beginning of the experiment (control group), and the remaining 28 were divided into 4 groups, each slaughtered at 42-day intervals. Their diet was composed of corn silage and concentrate (55:45). The power model was used to estimate muscle tissue, bone tissue, crude protein (CP), mineral matter (MM), and water present in the empty body, while the exponential model was used to estimate adipose tissue and ether extract (EE) present in the empty body. When expressed in kilograms per day, differences were observed (P?<?0.05) only for the intake of EE and neutral detergent fiber as a function of feedlot time periods. Although there was a difference in relation to nutrient intake, it did not affect (P?>?0.05) digestibility, with the exception of EE digestibility. The equation suggested by BR CORTE correctly estimates the DMI of Nellore bulls. ADG was not affected (P?>?0.05) by time spent in the feedlot. No differences were observed (P?>?0.05) for microbial efficiency; a mean value of 142 g microbial crude protein/kg total digestible nutrients was achieved. The muscle and bone tissues, CP, MM, and water present in the empty body increased as the animal grew, although at a lower rate. The adipose tissue and EE present in the empty body increased their deposition rate when the animal reached its mature weight. Maturity is defined as when an animal reaches 22 % EE in the empty body, which corresponds to 456 kg of EBW in Nellore bulls. Therefore, this study can conclude that the feedlot time period does not affect DMI, nutrient intake, ADG, or microbial efficiency. The equation proposed by BR CORTE (Azevêdo et al. 2010) correctly estimates the DMI of Nellore bulls, which reach maturity when an EBW of 456 kg is attained.     

Anti HSV-1 Activity of Halistanol Sulfate and Halistanol Sulfate C Isolated from Brazilian Marine Sponge Petromica citrina (Demospongiae)

The n-butanol fraction (BF) obtained from the crude extract of the marine sponge Petromica citrina, the halistanol-enriched fraction (TSH fraction), and the isolated compounds halistanol sulfate (1) and halistanol sulfate C (2), were evaluated for their inhibitory effects on the replication of the Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the viral plaque number reduction assay. The TSH fraction was the most effective against HSV-1 replication (SI = 15.33), whereas compounds 1 (SI = 2.46) and 2 (SI = 1.95) were less active. The most active fraction and these compounds were also assayed to determine the viral multiplication step(s) upon which they act as well as their potential synergistic effects. The anti-HSV-1 activity detected was mediated by the inhibition of virus attachment and by the penetration into Vero cells, the virucidal effect on virus particles, and by the impairment in levels of ICP27 and gD proteins of HSV-1. In summary, these results suggest that the anti-HSV-1 activity of TSH fraction detected is possibly related to the synergic effects of compounds 1 and 2.