Comparative evaluation of PCR in Ziehl-Neelsen stained smears and PCR in tissues for diagnosis of Mycobacterium avium subsp. paratuberculosis

Thirty six tissues from sheep, previously diagnosed with paratuberculosis, were tested by PCR in positive Ziehl-Neelsen staining smears of tissues, and PCR in tissues targeting IS900 specific for Mycobacterium avium subsp. paratuberculosis. DNA amplification was achieved in 33.3% Ziehl-Neelsen smears, and in 61.1% tissue samples. Combination of both techniques found 66.7% samples as positive. Combination of techniques would, therefore, increase the sensitivity of diagnosis.     

Clomipramine Treatment and Repeated Restraint Stress Alter Parameters of Oxidative Stress in Brain Regions of Male Rats

This study aimed to compare the effects of repeated restraint stress alone and the combination with clomipramine treatment on parameters of oxidative stress in cerebral cortex, striatum and hippocampus of male rats. Animals were divided into control and repeated restraint stress, and subdivided into treated or not with clomipramine. After 40 days of stress and 27 days of clomipramine treatment with 30 mg/kg, the repeated restraint stress alone reduced levels of Na⁺, K⁺-ATPase in all tissues studied. The combination of repeated restraint stress and clomipramine increased the lipid peroxidation, free radicals and CAT activity as well as decreased levels of NP-SH in the tissues studied. However, Na⁺, K⁺-ATPase level decreased in striatum and cerebral cortex and the SOD activity increased in hippocampus and striatum. Results indicated that clomipramine may have deleterious effects on the central nervous system especially when associated with repeated restraint stress and chronically administered in non therapeutic levels.     

Altered expression of cytokeratins in primary,recurrent and syndrome keratocystic odontogenic tumors

Keratocystic odontogenic tumor (KOT) is a benign cystic tumor that affects the jaw bones and may be associated with the nevoid basal cell carcinoma syndrome (NBCCS). Twenty-five cases diagnosed as KOT, including primary and recurrent tumors and those associated with NBCCS, were submitted to immunohistochemical study for analysis of cytokeratins (CKs) 7, 8, 10, 13, 14, 18 and 19. The results showed CK13 immunostained on the intermediate layers and upper cells. CK14 was expressed in all epithelial layers and in those areas where inflammation and subepithelial splits were present; this protein was preserved within the basal cells. CK 18 was expressed mainly in the basal layer, whereas CK19 was expressed mainly on the intermediate and superficial layers. The remaining CKs tested were not immuoreactive. The status of maturation of cytokeratin seems to be altered on KOTs, and this is not distinct when different tumors are compared.     

The effects of dietary supplementation of methionine on genomic stability and p53 gene promoter methylation in rats

Methionine is a component of one-carbon metabolism and a precursor of S-adenosylmethionine (SAM), the methyl donor for DNA methylation. When methionine intake is high, an increase of S-adenosylmethionine (SAM) is expected. DNA methyltransferases convert SAM to S-adenosylhomocysteine (SAH). A high intracellular SAH concentration could inhibit the activity of DNA methyltransferases. Therefore, high methionine ingestion could induce DNA damage and change the methylation pattern of tumor suppressor genes. This study investigated the genotoxicity of a methionine-supplemented diet. It also investigated the diet's effects on glutathione levels, SAM and SAH concentrations and the gene methylation pattern of p53. Wistar rats received either a methionine-supplemented diet (2% methionine) or a control diet (0.3% methionine) for six weeks. The methionine-supplemented diet was neither genotoxic nor antigenotoxic to kidney cells, as assessed by the comet assay. However, the methionine-supplemented diet restored the renal glutathione depletion induced by doxorubicin. This fact may be explained by the transsulfuration pathway, which converts methionine to glutathione in the kidney. Methionine supplementation increased the renal concentration of SAH without changing the SAM/SAH ratio. This unchanged profile was also observed for DNA methylation at the promoter region of the p53 gene. Further studies are necessary to elucidate this diet's effects on genomic stability and DNA methylation.     

Metabotropic glutamate and dopamine receptors co-regulate AMPA receptor activity through PKA in cultured chick retinal neurones: effect on GluR4 phosphorylation and surface expression

Glutamate receptor phosphorylation has been implicated in several forms of modulation of synaptic transmission. It has been reported that protein kinase A (PKA) can phosphorylate the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit GluR4 on Ser842, both in vitro and in vivo. Here, we studied the regulation of GluR4 phosphorylation and intracellular trafficking by PKA and by metabotropic receptors coupled to adenylyl cyclase (AC), in cultured chick retinal amacrine-like neurones, which are enriched in GluR4. The regulation of AMPA receptor activity by PKA and by metabotropic AC-coupled receptors was also investigated by measuring the [Ca2+]i response to kainate in Na(+)-free medium. Stimulation of AC with forskolin (FSK), or using the selective agonist of dopamine D1 receptors (+/-)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol (SKF38393), increased the [Ca2+]i response to kainate, GluR4 phosphorylation at Ser842 and GluR4 surface expression. Pre-incubation of the cells with (2S,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)glycine (DCG-IV), an agonist of group II metabotropic glutamate receptors (mGluR), which are coupled to inhibition of AC, inhibited the effect of FSK and of SKF38393 on AMPA receptor activity, GluR4 phosphorylation and expression at the plasma membrane. These results indicate that there is a functional cross-talk between dopamine D1 receptors and group II mGluR in the regulation of GluR4 phosphorylation and AMPA receptor activity. Our data show that GluR4 phosphorylation at Ser842 by PKA, and its recruitment to the plasma membrane upon phosphorylation, is regulated by metabotropic receptors.     

Hierarchical genetic and spatial structure among varieties and populations of Hymenaea stigonocarpa (Fabaceae) in Brazilian savannah

Tree Genetics & Genomes - Tree breeders must almost always address multiple traits. That entails choosing selection methods and weighing up known or assumed economic-worth functions for traits....     

Olfactory responses of Anaphes nitens (Hymenoptera,Mymaridae) to host and habitat cues

The eucalyptus weevil, Gonipterus spp. Schoenherr, 1833 (Coleoptera, Curculionidae) is considered a major pest of eucalyptus plantations. In regions where control is achieved, success is usually brought by the action of the solitary egg parasitoid Anaphes nitens (Girault, 1928) (Hymenoptera, Mymaridae). Research was conducted to ascertain which cues might mediate female wasp host location and selection. In Petri dish arenas, females were attracted to Gonipterus platensis Marelli, 1927 egg capsules, to G. platensis mated female faeces and to leaves of Eucalyptus globulus Labillardière, 1799. Gas chromatography–mass spectrometry electroantennographic detection analysis was conducted using extracts obtained from leaves of E. globulus, from G. platensis egg capsules, as well as from adults of both sexes and their faeces, in order to detect and identify compounds perceived by the wasp's olfactory system. The parasitoids were shown to detect a wide range of compounds emitted by each one of these sources, and for 31 compounds, antennal response was confirmed by dose-response tests. Further behavioural trials were conducted in Petri dishes in order to decode the effect, on parasitoid behaviour, of selected compounds emitted by E. globulus and of the pheromones, emitted by the weevils on parasitoid behaviour. Attraction was observed to two compounds emitted by E. globulus, namely 1,8-cineole and γ-terpinene, and to the main component of the male sex/aggregation pheromone, cis-verbenol. To our knowledge, this is the first report of attraction of a parasitoid from the family Mymaridae to a component of its host's sexual/aggregation pheromone. Similarly, to other egg parasitoid species, A. nitens females are likely to use the host plant volatiles as long-range host location cues and to adopt the ‘infochemical detour’ strategy in order to get in the vicinity of their hosts.