Prevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in ovine from São Paulo State, Brazil

Serum samples from 597 sheep from S?o Paulo State, in the southeastern region of Brazil, were tested to determine the prevalence of antibodies directed against Toxoplasma gondii (> or = 1:64) and Neospora caninum (> or = 1:50) using the indirect fluorescent antibody test (IFAT). The animals were divided into three groups based on their age: < or = 1 year, 1-4 years, and > or = 4 years. Antibodies to T. gondii were observed in 34.7% of the samples with titers ranging from 64 to 16,384 and IgG antibodies directed against N. caninum were observed in 9.2%, with titers ranging from 50 to 3200. Only 3.5% of the sheep were positive for both agents. All farms had at least one positive animal for T. gondii, and 26 of the 30 farms had at least one positive animal for N. caninum. An association between seroprevalence and age was observed for T. gondii (P = 0.001), but not to N. caninum (P = 0.343). It was not possible to associate seroprevalence to T. gondii and the presence of domestic or feral cats, since in all farms there was at least one positive sheep. There was no association between seropositivity to N. caninum and the presence of domestic (P = 1.000) and feral dogs (P = 0.550).     

Evolutionary plasticity of monooxygenase-mediated resistance

The cytochrome P450 monooxygenases are an important metabolic system involved in the detoxification of xenobiotics, and are thus one of the major mechanisms by which insects evolve insecticide resistance. However, comparatively little is known about the evolutionary constraints of this insecticide resistance mechanism. We investigated the genetic basis of resistance in a strain of house fly (NG98) from Georgia, USA that had evolved 3700-fold resistance to the pyrethroid insecticide permethrin, and compared this to other permethrin resistant strains of house flies from the US and Japan. Resistance in NG98 was due to kdr on autosome 3 and monooxygenase-mediated resistance on autosomes 1, 2, and 5. These results indicate that the genes which evolve to produce monooxygenase-mediated resistance to permethrin are different between different populations, and that the P450 monooxygenases have some degree of plasticity in response to selection. Monooxygenase-mediated resistance appears to evolve using different P450s, and possibly different regulatory signals controlling P450 expression, even in strains selected with the same insecticide.     

Seroprevalence of Neospora caninum in female water buffaloes (Bubalus bubalis) from the southeastern region of Brazil

Antibodies to Neospora caninum were assayed in sera of 222 female water buffaloes from Ribeira Valley of S?o Paulo State, Brazil, using an indirect fluorescent antibody test (IFAT) and Neospora agglutination test (NAT). IFAT antibodies were found in 64% of buffaloes with titers of 1:25 (42 buffaloes), 1:50 (53 buffaloes), 1:100 (31 buffaloes), 1:200 (10 buffaloes), 1:400 (3 buffaloes), or > or =1:800 (3 buffaloes). NAT antibodies were found in 53% of buffaloes; in titers of 1:40 in 52 buffaloes, 1:80 in 27 buffaloes, 1:160 in 21 buffaloes, and > or =1:320 in 17 buffaloes. Results indicate a high prevalence of N. caninum exposure in water buffaloes in Brazil and warrant an investigation of the role of N. caninum as an abortifacient in water buffaloes.     

Influence of dietary conjugated linoleic acid isomers on early inflammatory responses in male broiler chickens

1. The influence of dietary conjugated linoleic acid isomer (CLA, 0 and 10 g/kg) on the metabolic and physiological responses to immune stimulation induced by a single injection of Salmonella enteritidis lipopolysaccharide (LPS) or repeated injections of LPS and Sephadex G-50 was determined in male broiler chicks. 2. In experiment 1, 10-d-old chicks were fed on experimental diets for 14 d and half of the birds fed on each diet were injected intraperitoneally with LPS (1.5 mg/kg body weight). In experiment 2,7-d-old chicks were fed on experimental diets for 18 d. Immune stimulation was started at 19 d old and continued for 5 d. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of LPS at 19, 21 and 23 d of age, and with 250 mg/kg body weight of Sephadex at 20 and 22 d of age to stimulate the immune system. 3. In experiment 1, giving CLA prevented an increase in blood heterophil to lymphocyte ratio 7 h after a single injection of LPS, and increases in plasma ceruloplasmin and alpha 1 acid glycoprotein (AGP) 24 h after the injection, but not 7 h after the injection. CLA also prevented a decrease in food intake for 24 h after LPS injection. 4. In experiment 2, the CLA diet partially prevented reductions in body weight gain and weight gain to feed intake ratio caused by repeated injections of LPS and Sephadex. Feeding CLA prevented increases in plasma ceruloplasmin and AGP at 24 d of age caused by repeated injections of LPS and Sephadex, but not at 20 d of age. 5. These results suggest that feeding CLA alleviates some undesirable metabolic and physiological changes induced by immunological stimulation in male broiler chicks.     

Heinz body hemolytic anemia with eccentrocytosis from ingestion of Chinese chive (Allium tuberosum) and garlic (Allium sativum) in a dog

A 4-year-old, intact male miniature schnauzer was presented with anorexia. The dog had ingested some Chinese steamed dumplings 2 days before, which contained Chinese chive (Allium tuberosum) and garlic (Allium sativum). Hematological examinations revealed severe Heinz body hemolytic anemia with eccentrocytosis and an increased concentration of methemoglobin, which was thought to result from oxidative damage to erythrocytes by constituents in these Allium plants. In this case, eccentrocytosis was a hallmark finding and could be detected easily, suggesting that this hematological abnormality is useful in diagnosing Allium plant-induced hemolysis.     

Protein synthesis and neurotrophin-dependent structural plasticity of single dendritic spines

Long-term potentiation (LTP) at glutamatergic synapses is considered to underlie learning and memory and is associated with the enlargement of dendritic spines. Because the consolidation of memory and LTP require protein synthesis, it is important to clarify how protein synthesis affects spine enlargement. In rat brain slices, the repetitive pairing of postsynaptic spikes and two-photon uncaging of glutamate at single spines (a spike-timing protocol) produced both immediate and gradual phases of spine enlargement in CA1 pyramidal neurons. The gradual enlargement was strongly dependent on protein synthesis and brain-derived neurotrophic factor (BDNF) action, often associated with spine twitching, and was induced specifically at the spines that were immediately enlarged by the synaptic stimulation. Thus, this spike-timing protocol is an efficient trigger for BDNF secretion and induces protein synthesis-dependent long-term enlargement at the level of single spines.     

Water Absorption Characteristics and Volume Changes of Milled and Brown Rice During Soaking

The water absorption characteristics and volume changes of rice with various degrees of milling during soaking were measured at five temperatures (5–40°C). The measured data were fitted to the exact solution for the infinite plane sheet diffusion model, which is an exact solution for the diffusion equation. The measured results agreed well with the model. The effects of temperature and the degree of milling on the water absorption rate constant were investigated. Volume changes of samples were determined by measuring particle density and bulk density. An empirical equation relating the moisture content of the sample during soaking and at temperatures of 10–50°C to specific volume was derived. In addition, bulk density was related to the quadratic function of the moisture content of the sample during soaking.