Ornithine decarboxylase expression in the small intestine of broilers submitted to feed restriction and glutamine supplementation

Six hundred and forty one-day-old Cobb male broilers were used to evaluate ornithine decarboxylase (ODC) expression in the mucosa of the small intestine. Birds were submitted to early feed restriction from 7 to 14 days of age. The provided feed was supplemented with glutamine. A completely randomized design with a 2 x 2 factorial arrangement was used (with or without glutamine, with or without feed restriction). Restricted-fed birds were fed at 30% the amount of the ad libitum fed group from 7 to 14 days of age. Glutamine was added at the level of 1% in the diet supplied from 1 to 28 days of age. Protein concentration in the small intestine mucosa was determined, and ODC expression at 7, 14, 21, and 28 days of age was evaluated by dot blotting. ODC was present in the mucosa of broilers, and the presence of glutamine in the diet increased ODC activation. Glutamine prevented mucosa atrophy by stimulating protein synthesis, and was effective against the effects of feed restriction. Dot blotting can be used to quantify ODC expression in the intestinal mucosa of broilers.

Immunohistochemical characterization of mononuclear cells and MHC II expression in the brain of horses with experimental chronic Trypanosoma evansi infection

Este estudo objetivou caracterizar a resposta imune celular no sistema nervoso central (SNC) de eqüinos com infecção crônica experimental por Trypanosoma evansi. Para este propósito, foram utilizados os métodos histoquímicos (HE) e imunoistoquímicos do complexo avidina-biotina peroxidase (ABC). O fenótipo do infiltrado celular foi caracterizado com o auxílio de anticorpos anti - CD3, para linfócitos T e antiBLA36 para linfócitos B. Os macrófagos foram marcados com anticorpo antiantígenos da linhagem mielóide/histiócitos (Clone Mac387). A lesão no sistema nervoso central (SNC) dos eqüinos infectados com T. evansi foi caracterizada como meningoencefalite e meningomielite não supurativa. A gravidade das lesões variou em diferentes segmentos do SNC, refletindo distribuição irregular das alterações vasculares. A distribuição de células T e B e antígenos do complexo maior de histocompatibilidade classe II foram avaliados dentro do SNC de eqüinos cronicamente infectados com T. evansi. O infiltrado perivascular e meníngeo eram constituídos predominantemente por células T e B. Macrófagos foram raramente visualizados. T.evansi não foi identificado no parênquima do SNC dos eqüinos.

The maspin expression in canine mammary tumors: an immunohistochemical and molecular study

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

Sites of Defoliation by Atta sexdens rubropilosa (Hymenoptera, Formicidae) in Artificial Plants

This study aimed to achieve a better understanding about the foraging behavior of leaf-cutter ant (Atta sexdens rubropilosa Forel) workers with respect to defoliation sites in plants. To accomplish that, artificial plants 70 cm in height were prepared and divided into four levels (heights), having natural plant leaves attached to them. Evaluations during the bioassays included the number of leaves dropped by the ants, as well as the percentage of plant mass removed. In all replicates, it became evident that the most exploited plant site is the apical region, which significantly differed from other plant levels.

Cigarette smoke exposure severely reduces peripheral insulin sensitivity without changing GLUT4 expression in oxidative muscle of Wistar rats

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

BUBR1 expression in benign oral lesions and squamous cell carcinomas: Correlation with human papillomavirus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dexamethasone-induced insulin resistance is associated with increased connexin 36 mRNA and protein expression in pancreatic rat islets

Augmented glucose-stimulated insulin secretion (GSIS) is an adaptive mechanism exhibited by pancreatic islets from insulin-resistant animal models. Gap junction proteins have been proposed to contribute to islet function. As such, we investigated the expression of connexin 36 (Cx36), connexin 43 (Cx43), and the glucose transporter Glut2 at mRNA and protein levels in pancreatic islets of dexamethasone (DEX)-induced insulin-resistant rats. Study rats received daily injections of DEX (1 mg/kg body mass, i.p.) for 5 days, whereas control rats (CTL) received saline solution. DEX rats exhibited peripheral insulin resistance, as indicated by the significant postabsorptive insulin levels and by the constant rate for glucose disappearance (K-ITT). GSIS was significantly higher in DEX islets (1.8-fold in 16.7 mmol/L glucose vs. CTL, p < 0.05). A significant increase of 2.25-fold in islet area was observed in DEX vs. CTL islets (p < 0.05). Cx36 mRNA expression was significantly augmented, Cx43 diminished, and Glut2 mRNA was unaltered in islets of DEX vs. CTL (p < 0.05). Cx36 protein expression was 1.6-fold higher than that of CTL islets (p < 0.05). Glut2 protein expression was unaltered and Cx43 was not detected at the protein level. We conclude that DEX-induced insulin resistance is accompanied by increased GSIS and this may be associated with increase of Cx36 protein expression.

Time course of training-induced microcirculatory changes and of vegf expression in skeletal muscles of spontaneously hypertensive female rats

Exercise-induced vessel changes modulate arterial pressure (AP) in male spontaneously hypertensive rats (SHR). Vascular endothelial growth factor (VEGF) is important for angiogenesis of skeletal muscle. The present study evaluated the time course of VEGF and angiogenesis after short- and long-term exercise training of female SHR and Wistar Kyoto (WKY) rats, 8-9 weeks (200-250 g). Rats were allocated to daily training or remained sedentary for 3 days (N = 23) or 13 weeks (N = 23). After training, the carotid artery was catheterized for AP measurements. Locomotor (tibialis anterior and gracilis) and non-locomotor skeletal muscles (temporalis) were harvested and prepared for histologic and protein expression analyses. Training increased treadmill performance by all groups (SHR = 28%, WKY = 64%, 3 days) and (SHR = 141%, WKY = 122%, 13 weeks). SHR had higher values of AP than WKY (174 ± 4 vs 111 ± 2 mmHg) that were not altered by training. Three days of running increased VEGF expression (SHR = 28%, WKY = 36%) simultaneously with an increase in capillary-to-fiber ratio in gracilis muscle (SHR = 19%, WKY = 15%). In contrast, 13 weeks of training increased gracilis capillary-to-fiber ratio (SHR = 18%, WKY = 19%), without simultaneous changes in VEGF expression. Training did not change VEGF expression and capillarity of temporalis muscle. We conclude that training stimulates time- and tissue-dependent VEGF protein expression, independent of pressure levels. VEGF triggers angiogenesis in locomotor skeletal muscle shortly after the exercise starts, but is not involved in the maintenance of capillarity after long-term exercise in female rats.

Genotoxicity, cytotoxicity and gene expression in patients undergoing elective surgery under isoflurane anaesthesia

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

Triiodothyronine (T3) does not induce RANKL expression in rat ROS 17/2.8 cells

Osteoclastogenesis may be regulated via activation of the RANK/RANKL (receptor activator of nuclear factor-kappa B/ receptor activator of nuclear factor-kappa B ligand) system, which is mediated by osteoblasts. However, the bone loss mechanism induced by T3 (triiodothyronine) is still controversial. In this study, osteoblastic lineage rat cells (ROS 17/2.8) were treated with T3 (10(-8) M 10(-9) 10 M, and 10(-10) M), and RANKL mRNA (messenger RNA) expression was measured by semiquantitative RT-PCR. Our results show that T3 concentrations used did not significantly enhance RANKL expression compared to controls without hormone treatment. This data suggests that other mechanisms, unrelated to the RANK/RANKL system, might be to activate osteoclast differentiation in these cells.

Effect of Helicobacter pylori infection on IL-8, IL-1 and COX-2 expression in patients with chronic gastritis and gastric cancer

Objective. Helicobacter pylori infection is related to gastric cancer development, and chronic inflammation is presumed to be the main cause. The aim of the present study was to evaluate the influence of H. pylori cagA, vacA, iceA, and babA genotypes on COX-2, IL-1, and IL-8 expression. Material and methods. of the 217 patients included in the study, 26 were uninfected, 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by polymerase chain reaction (PCR), and the expression values were determined by quantitative real-time PCR and immunohistochemistry. Results. An association was found between the infection with cagA, vacA s1m1 strains and gastric cancer development. Regarding the 3' region of the cagA gene, we also found an association between the infection with cagA EPIYA-ABCCC strains and clinical outcome. Higher levels of IL-8, IL-1, and COX-2 were detected in gastric mucosa from infected patients with chronic gastritis, and they were also associated with the infection by cagA, vacA s1m1 strains. The IL-8 and IL-1 levels decrease significantly from chronic gastritis to gastric cancer, while the relative expression remained unaltered when COX-2 expression was analyzed among patients with gastritis and cancer. Conclusions. Since inflammatory response to H. pylori infection plays an important role in cellular proliferation and gastric mucosal damage, the up-regulation of IL-1, IL-8, and COX-2 in patients with chronic gastritis has an important clinical implication in gastric carcinogenesis.

Tamoxifen inhibits transforming growth factor-alpha gene expression in human breast carcinoma samples treated with triiodothyronine

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