Histological and immunological reaction of cattle skin to first-instar larvae of Dermatobia hominis

Six cattle that had earlier exposure to Dermatobia hominis were infested experimentally with first-instar larvae of the parasite. Skin biopsies taken at intervals were studied in wax and in plastic sections. The avidin-biotin-peroxidase method was used to detect the presence and localization of host immunoglobulins (Igs) G and M and antigens of first and second instar larvae of Dermatobia hominis. The larvae penetrated actively through the skin and migrated towards the subcutaneous tissues. The great numbers of eosinophils suggest that they are the most important cell in mediating damage to D.hominis larvae. The immunoglobulins bound only to dead or moulting larvae in which access to binding sites may have been altered. This could represent a morphological manifestation of a mechanism that protects larvae from the host immune response. Large amounts of soluble antigens detected along the fistulous tract may be important in the maintenance of this tract by disturbing the normal cicatrization process.

Antioxidant effect of saponin: potential action of a soybean flavonoid on glucose tolerance and risk factors for atherosclerosis

At the present time, much attention is being paid to antioxidant substances because many pathological conditions are associated with oxidative stress. The purpose of the present study was to discover the potency of saponin (2-phenyl-benzopyrane), a soybean flavonoid, with respect to its hypoglycaemic and hypolipidaemic action, and the association of these effects with oxidative stress. Male Wistar rats were divided into two groups (n = 6): control group and saponin-treated group (60 mg/kg) during 30 days. Saponin had no effects on glucose tolerance. Although no changes had been observed in low-density lipoprotein-cholesterol, saponin-treated animals had increased low-density lipoprotein-cholesterol/triacylglycerol ratio and decreased triacylglycerol, very low-density lipoprotein-cholesterol and total/high-density lipoprotein-cholesterol ratio than the control group. Saponin-treated rats showed lower lipid hydroperoxide than control rats, indicating decreased potential to atherosclerosis. No alterations were observed in antioxidant enzymes, superoxide dismutase and glutathione peroxidase, while lipid hydroperoxide were decreased in saponin-treated rats. In conclusion, the beneficial effects of saponin on serum lipids were related to a direct saponin antioxidant activity.

Leukocyte and thrombocyte reference values for channel catfish (Ictalurus punctatus Raf), with an assessment of morphologic, cytochemical, and ultrastructural features

Background: Hematology tests are useful to evaluate physiologic disturbances in fish and can provide important information for the diagnosis and prognosis of disease. Objectives: the primary purpose of this study was to define reference intervals for thrombocytes and leukocytes in healthy channel catfish (Ictalurus punctactus). In addition, the morphologic, cytochernical, and ultrastructural features of blood cells were assessed. Methods: Blood samples (0.5 mL were collected into EDTA from 40 clinically healthy catfish on a commercial fish farm in Jaboticabal, Brazil. Thrombocyte, total WBC, and differential WBC counts were determined and reference intervals were calculated as the 25-95th percentiles of data. Thrombocyte and leukocyte morphology was assessed in blood smears stained with May Griinwald-Giemsa-Wright and ultrastructurally by transmission electron microscopy. Cytochemical staining patterns were described using periodic acid-Schiff (PAS), peroxidase, nonspecific esterase, alkaline phosphatase, and toluidine blue. Results: Reference intervals were as follows: thrombocytes 58,802-99,569/mu L; total WBCs 27,460-41,523/mu L; lymphocytes 5380-11,581/mu L; monocytes 2949-7459/mu L; neutrophils 12,529-22,748/mu L, and basophils 736-2003/mu L. Neutrophils were positive for peroxidase and PAS; monocytes were positive for nonspecific esterase; and basophils were positive with toluidine blue. Conclusion: the morphologic and staining features of neutrophils and monocytes of channel catfish are similar to those of mammals, and the presence of basophils in this species was verified. These reference intervals and morphologic findings provide a foundation for future investigations on the functions and alterations of blood cells in channel catfish.

Qualidade do melão ‘Orange Flesh’ minimamente processado armazenado sob atmosfera modificada

This work aimed at evaluate the effect of the fresh cut 'Orange Flesh' melon stored under modified atmosphere. The cubes of melons were sanitizationed with 100 mg L-1 of hypoclorite of sodium for one minute, washed, drained and wrapped with different concentrations of O-2 and CO2 in plastic bags of polyethylene (Nylon Polished). They were appraised every other day for ten days as regards the firmness, total pectin, soluble pectin and activity of the polifenoloxidase and peroxidase. At the end of the conservation period, it was verified that melons sustained the firmest texture of the vegetable products under modified atmosphere, and the concentration of 5%O-2 + 3% CO2 showed smaller content of total pectin and together with the concentration of 100% N-2 the smallest content of soluble pectin, the polifenoloxidase activity was not verified as well as of the peroxidase.

Diets rich in saturated and polyunsaturated fatty acids: Metabolic shifting and cardiac health

OBJECTIVE: the aim of this study was to determine the effects of diets rich in saturated and polyunsaturated fatty acids on metabolic pathways and the relation of metabolic shifting to oxidative stress in cardiac tissue.METHODS: Male Wistar rats (age, 60 d; n = 10) were fed with a control low-fat diet, a diet rich in saturated fatty acids (SFAs), or a diet rich in polyunsaturated fatty acids (PUFAs). After 5 wk of treatment, sera were used for protein and lipid determinations. Protein, glycogen, triacylglycerol, lactate dehydrogenase, citrate synthase, beta-hydroxyacyl coenzyme-A dehydrogenase, catalase, glutathione peroxidase, superoxide dismutase, lipoperoxide, and lipid hydroperoxide were measured in cardiac tissue.RESULTS: the SFA group had higher triacylglycerol, cholesterol, low-density lipoprotein cholesterol, and atherogenic index (ratio of cholesterol to high-density lipoprotein) than did the PUFA and control groups. The PUFA group had low serum cholesterol, triacylglycerol, and low-density lipoprotein cholesterol as compared with the SFA group. SFA increased myocardial lipid hydroperoxide and diminished glutathione peroxidase. Despite the beneficial effects on serum lipids, the PUFA diet led to the highest levels of myocardial lipoperoxide and lipid hydroperoxide and diminished superoxide dismutase and catalase activities. The PUFA effects were related to increased feed efficiency, increased susceptibility to lipoperoxidation, and metabolic shifting in cardiac tissue. PUFA elevated triacylglycerol levels and decreased myocardial glycogen concentrations. The ratios of lactate dehydrogenase to citrate synthase and beta-hydroxyacyl coenzyme-A dehydrogenase to citrate synthase were increased, indicating myocardial reduction of tricarboxylic acid cycle.CONCLUSIONS: PUFAs have been recommended as a therapeutic measure in preventive medicine to lower serum cholesterol, but PUFAs increased oxidative stress in the heart by providing cardiac susceptibility to lipoperoxidation and shifting the metabolic pathway for energy production. The control diet, which was much lower in calories and fat, produced better overall clinical outcomes, better fat profiles, and less oxidative stress than did the diets rich in fatty acids.

Impact of the training program on lipid profile and cardiac health

The aim of this study was to investigate the effects of training programs on serum lipid profile and myocardial oxidative stress. Male Wistar rats (2 mo-old) were divided into three groups (n=8): sedentary (S), loadless trained (T) and trained-overload 2% body weight (TL). T and TL were trained through swimming for 9 weeks. T and TL rats had increased myocardial lipoperoxide (TBA) and lipid hydroperoxide (HP), whereas HP was higher in TL than in T animals. Superoxide dismutase (SOD) activities were lowest in TL. Myocardial glutathione peroxidase (GSH-Px) was lower in TL than in T and S rats. TL decreased HDL-cholesterol and increased LDL-cholesterol. The serum lactate dehydrogenase and TBA were increased, while SOD and GSH-Px activities were decreased in TL rats. Loadless training was able to improve HDL-cholesterol and to reduce LDL-cholesterol. In conclusion, the loadless training program induced beneficial effects on lipid profile, while overload training induced dyslipidemic profile that was associated with serum oxidative stress. The overload training program was deleterious relative to loadless training program, increasing myocardial oxidative stress.

Toxicity of ad lib. overfeeding: effects on cardiac tissue

The aim of the present study was to determine the effects of ad lib, overfeeding and of dietary restriction (DR) on oxidative stress in cardiac tissue. Lipoperoxide concentrations ere decreased and antioxidant enzymes ere increased in moderate-DR-fed rats. Severe-DR induced increased lipoperoxide concentrations. Overfeeding increased lipoperoxide levels in cardiac tissue. Total superoxide dismutase (SOD) and Cu-Zn superoxide dismutase (Cu-Zn SOD) activities were decreased in cardiac tissue at 35 days of overfeeding. As no changes in glutathione peroxidase (GSH-Px) ere observed in overfed rats, awhile SOD and Cu-Zn SOD activities were decreased in these animals. it is assumed that superoxide anion is an important intermediate in the toxicity of ad lib, overfeeding. Overfeeding induced alterations in markers of oxidative stress in cardiac tissue. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Absence of cross-reactivity to myeloperoxidase of anti-thyroid microsomal antibodies in patients with autoimmune thyroid diseases

Background: Thyroperoxidase is the major antigen of the thyroid microsomal antibodies (TMA) detected in autoimmune thyroid diseases. Its amino acid sequence has 44% homology with myeloperoxidase (MPO), an enzyme present in the primary granules of neutrophils and one of the major antineutrophil cytoplasmic antibodies (ANCA) antigens. The objective of the present study was to investigate the presence of cross-reactivity to MPO of TMA. Methods: We studied sera from 51 patients with autoimmune thyroid diseases, all of them TMA-positive. The presence of ANCA was investigated by indirect immunofluorescence and by capture enzyme-linked immunosorbent assay. Results: ANCA were positive in 3.9% of the TMA-positive sera and none of them reacted with MPO. In contrast, the ANCA-positive sera revealed antielastase activity. None of the ANCA-positive cases presented clinical signs of vasculitis. However, these 2 patients had been on prolonged treatment with propylthiouracil. Conclusions: We conclude that there is no cross-reactivity to MPO of TMA in patients with autoimmune thyroid diseases, possibly because of difference in the spatial configuration of the immunodominant region. The presence of ANCA in patients with autoimmune thyroid diseases without evidence of vasculitis might result from propylthiouracil-induced polyclonal activation.

INFLUENCE OF DIABETES-MELLITUS ON THE GLUTATHIONE REDOX SYSTEM OF HUMAN RED-BLOOD-CELLS

Several components of the erythrocyte-dependent glutathione redox system (reduced glutathione, GSH; oxidized glutathione, GSSG; glutathione peroxidase, GSH-Px; glutathione reductase, GSH-Red) were determined in patients with types I and II diabetes mellitus (DM). All groups studied were male subjects: G1, 20 young healthy individuals (aged 23.7 +/- 4.2 years); G2, 15 young insulin-treated type I DM patients; G3, 20 older insulin-treated type II DM patients; 04, 21 older oral hypoglycemic agent-treated type II DM patients; G5, 28 aged healthy individuals (aged 68.9 +/- 11.5 years). There were no differences between G1 and G2, G3 or G4 regarding erythrocyte GSH, GSSG, and GSH-Red (without FAD) levels. GSH-Px activity was significantly lower in G2 when compared to G1 (15.2 +/- 4.9 vs 20.6 +/- 6.6 IU/g Hb). The GSH-Red and GSH-Px activities and GSH levels were significantly higher in 03 (4.6 +/- 1.7 IU/g Hb, 20.2 +/- 8.7 IU/g Hb and 3.5 +/- 1.3-mu-M/g Hb) and G4 (5.0 +/- 2.2 IU/g Hb, 16.9 +/- 6.1 IU/g Hb and 5.0 +/- 2.3-mu-M/g Hb) when compared to G5 (3.4 +/- 0.9 IU/g Hb, 12.0 +/- 3.6 IU/g Hb and 2.3 +/- 0.9-mu-M/g Hb). The findings suggest that treatment of DM can stimulate the redox activity of red blood cells in aged subjects.

Analysis of tolerance to copper and zinc in Aechmea blanchetiana grown in vitro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Yeast biodiversity from oleic ecosystems: Study of their biotechnological properties

The aim of this study was to know the yeast biodiversity from fresh olive (Olea europaea L.) fruits, olive paste (crush olives) and olive pomace (solid waste) from Arbequina and Cornicabra varieties. Yeasts were isolated from fruits randomly harvested at various olive groves in the region of Castilla La Mancha (Spain). Olive paste and pomace, a byproduct of the processing of this raw material, were also collected in sterile flasks from different oil mills. Molecular identification methodology used included comparison of polymerase chain reaction (PCR) amplicons of their 5.8S rRNA gene and internal transcribed spacers ITS1 and ITS2 followed by restriction pattern analysis (RFLP). For some species, sequence analysis of the 5.8S rDNA gene was necessary. The results were compared to sequences held in public databases (BLAST). These techniques allowed to identify fourteen different species of yeasts, belonging to seven different genera (Zygosaccharomyces, Pichia, Lachancea, Kluyveromyces, Saccharomyces, Candida, Torulaspora) from the 108 yeast isolates. Species diversity was thus considerable: Pichia caribbica, Zygosaccharomyces fermentati (Lachancea fermentati) and Pichia holstii (Nakazawaea holstii) were the most commonly isolated species, followed by Pichia mississippiensis, Lachancea sp., Kluyveromyces thermotolerans and Saccharomyces rosinii. The biotechnological properties of these isolates, was also studied. For this purpose, the activity of various enzymes (beta-glucosidase, beta-glucanase, carboxymethylcellulase, polygalacturonase, peroxidase and lipase) was evaluated. It was important that none of species showed lipase activity, a few had cellulase and polygalacturonase activities and the majority of them presented beta-glucanase, beta-glucosidase and peroxidase activities. (C) 2010 Elsevier Ltd. All rights reserved.

Polysiloxane-poly(propylene oxide) hybrid discs as solid phase in anti-HCV detection using a recombinant core protein

In this work, siloxane-poly(propylene oxide) discs (PPO disc) prepared using the sol-gel process were used as solid phase in enzyme-linked immunosorbent assays (ELISA) for the detection of anti-hepatitis C virus (HCV) antibodies. The HCV RNA from serum (genotype 1b) was submitted to the RT-PCR technique and subsequent amplification of the HCV core 408 pb. This fragment was cloned into expression vector pET42a and expressed in Escherichia coli as recombinant protein with glutathione S-transferase (GST). Cell cultures were grown and induced having a final concentration of 0.4 x 10(-3) mol L-1 of IPTG. After induction, the cells were harvested and the soluble fraction was analyzed using polyacrilamide gel 15% showing a band with an approximate molecular weight of 44 kDa, the expected size for this GST-fused recombinant protein. The recombinant protein was purified and continued by immunological detection using HCV-positive serum and showed no cross-reactivity with positive samples for other infectious diseases. An ELISA was established using 1.25 ng of recombinant protein per PPO disc, a dilution of 1: 10,000 and 1:40 for a peroxidase conjugate and serum, respectively, and solutions of hydrogen peroxide and 3,3',5,5'-tetra-methylbenzidine in a ratio of 1: 1. The proposed methodology was compared with the ELISA conventional polystyrene-plate procedure and the performance of the PPO discs as a matrix for immunodetection gave an easy synthesis, good performance and reproducibility for commercial application. (c) 2007 Elsevier B.V. All rights reserved.

A disposable chitosan-modified carbon fiber electrode for dengue virus envelope protein detection

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Disulfide Biochemistry in 2-Cys Peroxiredoxin: Requirement of Glu50 and Arg146 for the Reduction of Yeast Tsa1 by Thioredoxin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)