Influence of murine Toxocara canis infection on plasma and bronchoalveolar lavage fluid eosinophil numbers and its correlation with cytokine levels     

Pecinali NR  Gomes RN  Amendoeira FC  Bastos AC  Martins MJ  Pegado CS  Bastos OM  Bozza PT  Castro-Faria-Neto HC 《Veterinary parasitology》2005,134(1-2):121-130

Toxocara canis is a nematode of the Ascaridae family that normally parasites the small intestine of canid species. Humans are accidentally infected upon ingestion of embryonated eggs, and can manifest several clinical alterations such as fever, hepatomegaly, splenomegaly, respiratory symptoms, muscle pain and anorexia. In the present work, we investigated the kinetics of tissue distribution of L2 larva in lungs, liver, kidney, brain, skeletal muscle and myocardium. Also, we analyzed the blood and bronchoalveolar lavage fluid (BAL) for levels of IL-6, IFN-gamma, eotaxin and Regulated on Activation Normal T Cell Expressed and Secreted (RANTES) in experimental murine T. canis infection. We observed liver, lung and kidney lesions correlated to larva migration as early as the first day of infection. After the seventh post-infection day, larva could also be detected in brain, skeletal muscle and heart, as an indicator of biphasic migration pattern. Increased inflammatory activity was detected in BAL and plasma of infected animals, as was an intense eosinophil migration associated with an increase in the levels of all the cytokines studied. In conclusion, our results establish a tight correlation between tissue lesions caused by larva migration and increased plasma levels of pro-inflammatory and eosinophil chemotactic cytokines. Thus, murine T. canis infection may prove to be useful in understanding the role of cytokines in infection.  相似文献   

Morphometric and quantitative evaluation of the NADH-diaphorase positive myenteric neurons of the jejunum of streptozotocin-diabetic rats supplemented with acetyl-L-carnitine     

De Miranda Neto MH  Defani MA  Fregonesi CE  Natali MR  Pereira A 《Anatomia, histologia, embryologia》2005,34(3):154-158

Summary In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia.  相似文献   

An attenuated Salmonella Enteritidis strain derivative of the main genotype circulating in Uruguay is an effective vaccine for chickens     

Betancor L  Schelotto F  Fernandez M  Pereira M  Rial A  Chabalgoity JA 《Veterinary microbiology》2005,107(1-2):81-89

We have recently reported that Salmonella enterica serovar Enteritidis (S. Enteritidis) strains circulating in Uruguay, are unevenly distributed among different genetic subtypes, with a predominant genotype that is a common contaminant of poultry-derived food and that accounts for the vast majority of human cases of food-borne disease. Herein, we describe the construction of a genetically-defined aroC derivative (LVR02) of a local strain of S. Enteritidis belonging to the major genetic type. We demonstrated the attenuation and the immunogenicity of that strain in a mouse model, and evaluated it as a vaccine for commercial layer chickens. LVR02 proved to be stable, attenuated, innocuous, immunogenic and to induce protective immunity against a S. Enteritidis challenge when used for oral vaccination. A single oral dose of LVR02 administered to newly hatched chickens induced protection against oral challenge with the parental virulent strain, preventing systemic and persistent intestinal infection and significantly reducing the shedding of the challenge strain in birds' feces. A second vaccine dose at 15 days post-hatching boosted the immunogenicity of the vaccine, and strengthened the protection achieved with a single dose. This strain may represent the basis of a live vaccine to be included in national control programs to reduce circulation of this pathogen in the country.  相似文献   

Phylogenetic analysis of the sigma 2 protein gene of turkey reoviruses     

Sellers HS  Linnemann EG  Pereira L  Kapczynski DR 《Avian diseases》2004,48(3):651-657

The open reading frame of the S3 segment encoding the sigma2 protein of four turkey reovirus field isolates was analyzed for sequence heterogeneity. The turkey reoviruses we present here have a 97% amino acid identity to turkey NC 98. The S3 nucleotide and amino acid sequence similarity was < or =61% and 78%-80%, respectively, when compared to the chicken reovirus isolates. Comparison of amino acid sequences from chickens and turkeys with that of a duck isolate revealed a 53% and 55% similarity, respectively. Phylogenetic analyses, based on both nucleotide and amino acid sequence, resulted in three major groups among the avian reoviruses; these groups were clearly separated by species. The results of this study provide further evidence, based on the deduced sigma2 sequence, that turkey reoviruses form a distinct, separate group relative to chicken and duck isolates. In addition, as a result of the limited sequence identity with their avian counterparts, turkey reoviruses could potentially be considered a separate virus species within subgroup 2 of the Orthoreovirus genus.  相似文献   

Cell proliferation in feline normal, hyperplastic and neoplastic mammary tissue--an immunohistochemical study     

Dias Pereira P  Carvalheira J  Gärtner F 《Veterinary journal (London, England : 1997)》2004,168(2):180-185

The expression of a proliferation cell marker in neoplastic and non-neoplastic mammary tissue in 31 cats was assessed by immunohistochemistry in formalin-fixed paraffin-embedded samples using a monoclonal antibody against nuclear antigen Ki-67 (MIB-1). The results revealed that cell proliferation was more intense in hyperplastic than in normal mammary tissue. Carcinomas exhibited a higher MIB-1 index than benign tumours. There was also a positive correlation between proliferative activity and the histological grade of carcinomas. Fibroadenomatous change, which is considered to be hyperplastic and associated with favourable biological behaviour, exhibited high proliferative activity involving both epithelial and mesenchymal components. MIB-1 detected in formalin-fixed material with pre-treatment with antigen retrieval solution appeared to be a reliable marker of proliferation in feline mammary tumours, but further studies are needed to investigate the value of this proliferation marker in predicting clinical outcome and/or as a prognostic factor in feline mammary lesions.  相似文献   

Effects of long-term dietary supplementation of monensin or saccharomyces cerevisiae on blood acid-base and productive performance in growing feedlot steers     

Castillo C  Benedito JL  Méndez J  García-Partida P  Vázquez P  Pereira V  López-Alonso M  Hernández J 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(11-12):480-485

The aim of this study was to evaluate the effects of two dietary supplements (monensin and a live yeast culture) on acid-base balance in steers maintained in a commercial feedlot system, considering effects over the growing period (14 to 23 weeks of age). A 63-day feedlot study was performed using 42 double-muscled Belgian Blue steers. Steers were allotted randomly to one of the three study groups: (1) control group [no supplementation, C], (2) monensin supplementation [MON] at a concentration of 30 mg/kg (DM basis), and (3) live Saccharomyces cerevisiae strain supplementation [SACC] at a dose of 500 mg/kg (DM basis).Venous blood samples were collected for the measurement of acid-base parameters and L-lactate. Production parameters were also used as a complementary tool for understanding the internal changes associated with supplementation. Our results show that during the study period no statistical differences were observed between supplemented and control steers, although non-supplemented animals tended to gain more efficiently than those fed monensin or yeast. Nevertheless, taking into account blood parameters, these control animals showed a greater risk of acid overload due to a more marked decline in blood buffer levels over time in comparison with supplemented steers although no differences were observed between monensin or yeast supplemented animals. Additionally, significant effect of supplementation was observed in packed cell volume (PCV) values.  相似文献   

Influence of Grain Processing on Acid–Base Balance in Feedlot Steers     

Castillo C  Hernández J  Méndez J  Llena J  Pereira V  López-Alonso M  Benedito JL 《Veterinary research communications》2006,30(7):823-837

Grain processing (e.g. grinding, steaming, pelleting, flaking) has been reported to modify the incidence of ruminal disturbances in feedlot cattle. This study investigated the effects of two grain processing methods widely used in Spanish feedlots (grinding and pelleting) on animal performance, blood acid–base balance, blood electrolyte levels and serum lactate in a 140-day feedlot experiment with double-muscled Belgian Blue steers. The main aim of the study was to evaluate the way in which these two feeds modify blood acid–base balance, which is closely associated with ruminal pH. In light of our results we conclude that the animals that received the pelleted feed showed a more stable acid–base balance over time than those fed a ground feed. Nevertheless, higher levels of L-lactate and lower base excess (BE) and HCO₃ ⁻ values for cattle fed pelleted grain reflect a greater risk of grain-acid overload.  相似文献   

Investigating phenotypic variability in Colletotrichum lindemuthianum populations     

Pinto JM  Pereira R  Mota SF  Ishikawa FH  Souza EA 《Phytopathology》2012,102(5):490-497

Colletotrichum lindemuthianum, causal agent of anthracnose in the common bean, has wide genetic variability. Differential bean cultivars and morphological and physiological characteristics were used to analyze 74 isolates of C. lindemuthianum collected in two counties in the state of Minas Gerais, Brazil. Six different races were found, with a predominance of race 65 at both locations. Isolates were classified according to their sensitivities to the fungicide thiophanate-methyl, normally used in the control of common bean anthracnose. In all, ≈10% of isolates were resistant to the fungicide in vitro. Characteristics such as indexes of mycelia growth rate, colony diameter, sporulation capacity, and percentage of germination demonstrated the high genetic variability of C. lindemuthianum. We also observed variation in conidial cytology. The conidia of most isolates showed septa formation after germination, in contrast to septa absence, previously reported in the literature. Sexual and asexual reproduction were evaluated for mechanisms that may contribute in the generation of variability in C. lindemuthianum. Conidial anastomosis tubes were commonly found, indicating that asexual reproduction can help increase variability in this species. Information from this study confirmed high variability in C. lindemuthianum and will guide future studies in basic knowledge and applied technologies.  相似文献   

Biometrical, biological, biochemical and molecular characteristics of Meloidogyne incognita isolates and related species     

Marcilene Fernandes Almeida dos Santos  Cleber Furlanetto  Maria Rita Alves Almeida  Marina Dechechi Gomes Carneiro  Fabiane Castro Mota  Ana Cristina Meneses Mendes Gomes  Natália Orrú Reis Silveira  Joelma Gardênia Pereira Silva  Philippe Castagnone-Sereno  Myrian Silvana Tigano  Regina Maria Dechechi Gomes Carneiro 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(4):671-684

Meloidogyne incognita is one of the most polyphagous species of root-knot nematodes occurring in Brazil and worldwide. Eight M. incognita isolates were studied, representing two enzymatic phenotypes (esterase and malate desydrogenase: I1/N1, I2/N1) and four cryptic Meloidogyne sp.1 (S2/N1) isolates, representing one cytological type (3n?=?40–46). Three M. hispanica isolates (Hi3/N1, 2n?=?32–36) and two of an atypical Meloidogyne sp.2 (S2a/N3, 3n?=?40–44) were included in this study for comparison. All isolates were tested with three M. incognita-specific molecular markers. The primer pairs B06F/R, miF/R and incK14F/R amplified three species-specific fragments of 1,200?bp, 955?bp and 399?bp, respectively for M. incognita and Meloidogyne sp.1 isolates. No amplification occurred in the M. hispanica and Meloidogyne sp.2 isolates, except with primers miF/R (1,650?bp). The genetic variability of the Meloidogyne spp. isolates was evaluated, using RAPD and ISSR markers. The phylogenetic analyses revealed two strongly supported monophyletic clades: clade I, consisting of M. hispanica and the atypical Meloidogyne sp.2 isolates, and clade II, clustering together all M. incognita and the Meloidogyne sp.1 isolates. Considering the biometrical, cytological and molecular approaches, it was possible to conclude that the isolates with three enzymatic phenotypes (I1/N1, I2/N1 and S2/N1) presented the characteristics described for M. incognita. Some correlations were detected between the isozymatic phenotypes and the tree topology (S2a/N3, Hi3/N1, I1/N1, S2/N1), but no strict correlation could be observed for the phenotype I2/N1 and one isolate of S2/N1. Morphologically, the Msp.2 isolates differ from M. incognita and M. hispanica by the female stylet features presenting straight cone tip and round pear shaped knobs, posteriorly sloping. The results of this study suggested that the Msp.2 isolates with phenotypes S2aN3 belong to a new or an unidentified species closely related to M. hispanica.  相似文献   

Sensitivity of Lasiodiplodia theobromae from Brazilian papaya orchards to MBC and DMI fungicides     

Alba Valéria da Silva Pereira  Ricardo Brainer Martins  Sami Jorge Michereff  Marcelo Bezerra da Silva  Marcos Paz Saraiva Camara 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(4):489-498

Stem rot caused by Lasiodiplodia theobromae is an important postharvest disease of papaya in Brazil, responsible for reducing the quality and quantity of fruits. Fungicide use is one of the main disease management measures. However, there are no estimates available of pathogen sensitivity to commonly employed fungicides. Therefore, the EC₅₀ from 120 isolates of L. theobromae from northeastern Brazil, representative of six populations of the pathogen, was estimated in vitro for fungicides of the methyl benzimidazole carbamates—MBC (benomyl and thiabendazole) and demethylation-inhibiting—DMI (imazalil, prochloraz, tebuconazole) groups. Mycelial growth on fungicide-free media and virulence on papaya fruits of the MBC-sensitive and non-sensitive isolates were compared. For MBCs, 8.4% of isolates were non-sensitive to fungicides. For the remaining 91.6%, the mean EC₅₀ ranged from 0.002 to 0.13 μg ml⁻¹ and 0.36 to 1.27 μg ml⁻¹ for benomyl and thiabendazole, respectively. For DMIs, the mean EC₅₀ range for imazalil was 0.001 to 2.27 μg ml⁻¹, 0.04 to 1.75 μg ml⁻¹ for prochloraz, and 0.14 to 4.05 μg ml⁻¹ for tebuconazole. The EC₅₀ values of non-sensitive isolates were significantly (P≤0.05) higher those for the sensitive isolates for each of the DMI fungicides. Differences (P≤0.05) were found in the levels of sensitivity to DMI fungicides among the isolate populations associated with orchards. The populations from two orchards were less sensitive to DMIs. No solid evidence was found for fitness costs relating to MBC non-sensitive isolates because mycelial growth in fungicide-free media and virulence on papaya fruits were similar to those of sensitive isolates.  相似文献