Capillary electrophoresis of caseino-peptides: influence of applied voltage and column temperature

The peptides formed upon action of purified cardoon rennet on the Ala₁₈₉-Phe₁₉₀-Leu₁₉₁-Leu₁₉₂-Tyr₁93 -casein fragment were separated by capillary electrophoresis in an uncoated fused silica capillary. There was a linear correlation between electrophoretic mobility and Z/M^2/3 (Z, net charge; M, molecular mass) under all experimental conditions tested; under the optimal condicitions, 25 kV and 40 °C, the correlation coefficient was 0.994. The reported method is fast (migration times less than 7 min) and may be used to study the action of aspartic proteinases on the C-terminal domain of -casein and thus to help elucidate their effect on cheese quality.     

Immunoblotting for the serodiagnosis of Helicobacter pylori infection in Brazilian patients with and without gastric carcinoma

We evaluated the performance of a commercial immunoblotting in the serodiagnosis of Helicobacter pylori infection in Brazilian patients. The presence of anti-H. pylori antibodies was also investigated in a group of 20 duodenal ulcer patients after successful treatment. One hundred and ninety one patients were studied. Among the 164 infected patients, 46 had gastric carcinoma. The duodenal ulcer patients were treated with antimicrobial drugs and the eradication of the microorganism was confirmed in all of them one month after the end of the treatment by the 13C-urea breath test. Sera were assayed for H. pylori antibodies using the Helicoblot 2.0 (Genelabs Diagnostics, Singapore). The sensitivity, specificity, positive, and negative predictive values of the test were 93.9%, 92.6%, 98.7%, and 71.4%, respectively. The sensitivity of the test was similar in patients with (93.5%) and without (95.7%) gastric carcinoma. Twenty-four months after the end of the treatment, the band of 116 kDa was still detected in one of the patients. In conclusion, the Helicoblot 2.0 is an accurate test to diagnose H. pylori infection and although it can not be employed to monitor the bacterium eradication, it may be useful for diagnosing past infection, especially in gastric carcinoma patients.     

Specific antibody levels and antigenic recognition of Wistar rats inoculated with distinct isolates of Trypanosoma evansi.

"Mal de Cadeiras", an enzootic disease caused by Trypanosoma evansi, is one of the most important trypanosomiases in the Brazilian Pantanal region. The disease affects mainly horses, which are widely used in extensive cattle production, an activity of greatest economical significance for the region. The parasite also infects sylvan (coatis and capybaras) and domestic (dogs) animals, respectively considered wild and domestic reservoirs of T. evansi. For a better understanding of the interaction of T. evansi with its rodent host, we evaluated the differences in the specific antibody level patterns and in the parasitic peptides recognition patterns of experimentally infected Wistar rats. The rats experimentally infected with T. evansi isolates obtained from coatis, dogs and horses were submitted to indirect immunofluorescence test (IgM e IgG) and Western blotting. The serological titers for IgM and IgG ranged between 1:40 and 1:160. The most recognized polypeptide profiles were in a range of 17 and 74 kDa. Our data suggest that the humoral immune response in Wistar rats is not sufficient for granting an effective control of T. evansi infections.     

Nitric oxide synthase-mediated phytoalexin accumulation in soybean cotyledons in response to the Diaporthe phaseolorum f. sp. meridionalis elicitor

Phytoalexin biosynthesis is part of the defense mechanism of soybean (Glycine max) plants against attack by the fungus Diaporthe phaseolorum f. sp. meridionalis (Dpm), the causal agent of stem canker disease. The treatment of soybean cotyledons with Dpm elicitor or with sodium nitroprusside (SNP), a nitric oxide (NO) donor, resulted in a high accumulation of phytoalexins. This response did not occur when SNP was replaced by ferricyanide, a structural analog of SNP devoid of the NO moiety. Phytoalexin accumulation induced by the fungal elicitor, but not by SNP, was prevented when cotyledons were pretreated with NO synthase (NOS) inhibitors. The Dpm elicitor also induced NOS activity in soybean tissues proximal to the site of inoculation. The induced NOS activity was Ca(2+)- and NADPH-dependent and was sensitive to the NOS inhibitors N(G)-nitro-L-arginine methyl ester, aminoguanidine, and L-N(6)-(iminoethyl) lysine. NOS activity was not observed in SNP-elicited tissues. An antibody to brain NOS labeled a 166-kD protein in elicited and nonelicited cotyledons. Isoflavones (daidzein and genistein), pterocarpans (glyceollins), and flavones (apigenin and luteolin) were identified after exposure to the elicitor or SNP, although the accumulation of glyceollins and apigenin was limited in SNP-elicited compared with fungal-elicited cotyledons. NOS activity preceded the accumulation of these flavonoids in tissues treated with the Dpm elicitor. The accumulation of these metabolites was faster in SNP-elicited than in fungal-elicited cotyledons. We conclude that the response of soybean cotyledons to Dpm elicitor involves NO formation via a constitutive NOS-like enzyme that triggers the biosynthesis of antimicrobial flavonoids.     

Prevalence of cagA and vacA genes in isolates from patients with Helicobacter pylori-associated gastroduodenal diseases in Recife, Pernambuco, Brazil

Geographical differences in the prevalence of Helicobacter pylori genes and their association with disease severity have been identified. This study analyzes the prevalences of the cagA gene and alleles of the vacA gene in H. pylori-associated gastroduodenal diseases in isolates from Recife, PE, Brazil. Gastric biopsy of 61 H. pylori-positive patients were submitted to DNA extraction and gene amplification by polymerase chain reaction. Among the 61 patients, 21 suffered from duodenal ulcer (DU) and 40 from gastritis (GT). The prevalence of H. pylori strains harbouring the cagA gene was higher in the DU group (90.5%) than in the GT group (60%) (p=0.02). The vacA gene was amplified in 56 out of 61 biopsies, of which 43 (76.8%) contained bacteria carrying the s1 allele and 13 (23.2%) the s2. However, the prevalence of the vacA s1 genotyping was the same in either DU or GT group. The majority of the s1-typed strains, 39 (90.7%) out of 43, were subtype s1b. In resume there was a strong association between the H. pylori cagA+ gene and DU. However, there were no differences between the DU and GT groups in relation to the vacA s1 and s2 alleles distribution, albeit the subtype s1b was predominant.     

Trophic ecology of three stingrays (Myliobatoidei: Dasyatidae) off the Brazilian north-eastern coast: Habitat use and resource partitioning

Understanding the ecological role of species with overlapping distributions is central to inform ecosystem management. Here we describe the diet, trophic level and habitat use of three sympatric stingrays, Hypanus guttatus, H. marianae and H. berthalutzae, through combined stomach content and stable isotope (δ¹³C and δ¹⁵N) analyses. Our integrated approach revealed that H. guttatus is a mesopredator that feeds on a diverse diet of benthic and epibenthic marine and estuarine organisms, principally bivalve molluscs, Alpheus shrimp and teleost fishes. Isotopic data supported movement of this species between marine and estuarine environments. H. berthalutzae is also a marine generalist feeder, but feeds primarily on teleost fishes and cephalopods, and consequently occupies a higher trophic level. In contrast, H. marianae is a mesopredator specialized on shrimps and polychaetas occurring only in the marine environment and occupying a low niche breadth. While niche overlap occurred, the three stingrays utilized the same prey resources at different rates and occupied distinct trophic niches, potentially limiting competition for resources and promoting coexistence. These combined data demonstrate that these three mesopredators perform different ecological roles in the ecosystems they occupy, limiting functional redundancy.     

Terlipressin versus Norepinephrine in the Treatment of Hepatorenal Syndrome: A Systematic Review and Meta-Analysis

Background

Hepatorenal syndrome (HRS) is a severe and progressive functional renal failure occurring in patients with cirrhosis and ascites. Terlipressin is recognized as an effective treatment of HRS, but it is expensive and not widely available. Norepinephrine could be an effective alternative. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of norepinephrine compared to terlipressin in the management of HRS.

Methods

We searched the Medline, Embase, Scopus, CENTRAL, Lilacs and Scielo databases for randomized trials of norepinephrine and terlipressin in the treatment of HRS up to January 2014. Two reviewers collected data and assessed the outcomes and risk of bias. The primary outcome was the reversal of HRS. Secondary outcomes were mortality, recurrence of HRS and adverse events.

Results

Four studies comprising 154 patients were included. All trials were considered to be at overall high risk of bias. There was no difference in the reversal of HRS (RR = 0.97, 95% CI = 0.76 to 1.23), mortality at 30 days (RR = 0.89, 95% CI = 0.68 to 1.17) and recurrence of HRS (RR = 0.72; 95% CI = 0.36 to 1.45) between norepinephrine and terlipressin. Adverse events were less common with norepinephrine (RR = 0.36, 95% CI = 0.15 to 0.83).

Conclusions

Norepinephrine seems to be an attractive alternative to terlipressin in the treatment of HRS and is associated with less adverse events. However, these findings are based on data extracted from only four small studies.     

Endomycopsis montevidensis n. sp.

A new species of the genusEndomycopsis is proposed. It was isolated from wast water, at Montevideo-Uruguay.By its morphological and biochemical proprieties it differs from allEndomycopsis previously described.Este trabajo fue desarrollado en el Laboratorio de Micologia de la Facultad de Quimica de Montevideo, Uruguay y en uso de una beca de la Universidad Federal de Pernambuco para perfeccio bamiento en el estudo de las levaduras.