903 resultados para Indirectly affects


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The aim of this study was to investigate the hormonal regulation of the avian homolog of mammalian uncoupling protein (avUCP) by studying the impact of thyroid hormones and insulin on avUCP mRNA expression in chickens (Gallus gallus). For 3 wk, chicks received either a standard diet (control group), or a standard diet supplemented with triiodothyronine (T-3; T3 group) or with the thyroid gland inhibitor methimazole (MMI group). A fourth group received injections of the deiodinase inhibitor iopanoic acid (IOP group). During the 4th wk of age, all animals received two daily injections of either human insulin or saline solution. The results indicate a twofold overexpression of avUCP mRNA in gastrocnemius muscle of T3 birds and a clear downregulation (-74%) in MMI chickens compared with control chickens. Insulin injections had no significant effect on avUCP mRNA expression in chickens. This study describes for the first time induction of avUCP mRNA expression by the thermogenic hormone T3 in chickens and supports a possible involvement of avUCP in avian thermogenesis.

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Maternal separation is known to exert long-term effects on both behavior and the neuroendocrine system. We investigated cocaine-induced locomotor activation as well as the locomotor and corticosterone response to forced novelty in maternally separated adolescent and adult rats. Maternal separation consisted of separating litters from their darns daily during 5 h from postnatal days 2 to 6. Control animals were subjected only to regular cage changes. Cocaine- (10 mg/kg, i.p.) and novelty-induced locomotion were recorded in an activity cage. After the animals were tested for behavioral response to novelty, trunk blood samples were collected and plasma corticosterone levels were determined by radioimmunoassay. Adolescent rats exposed to maternal separation exhibited an increased locomotor response to novelty and cocaine; corticosterone levels were lower in these adolescent animals, after exposure to the novel environment. These effects of materrial separation were not observed in rats that were tested as adults. Thus the maternal separation protocol produced enduring but transient changes in the behavioral response to cocaine and in the stress response to novelty. (C) 2004 Elsevier B.V. All rights reserved.

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The putative translation factor eIF5A is essential for cell viability and is highly conserved from archebacteria to mammals. Although this protein was originally identified as a translation initiation factor, subsequent experiments did not support a role for eIF5A in general translation. In this work, we demonstrate that eIF-5A interacts with structural components of the 80S ribosome, as well as with the translation elongation factor 2 (eEF2). Moreover, eIF5A is further shown to cofractionate with monosomes in a translation-dependent manner. Finally, eIF5A mutants show altered polysome profiles and are sensitive to translation inhibitors. Our results re-establish a function for eIF5A in translation and suggest a role for this factor in translation elongation instead of translation initiation. (c) 2006 Elsevier B.V. All rights reserved.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Many of the nosological features, subtypes, biochemical, neurophysiological mechanisms, and therapeutic proposals are controversial in depression. Methods: We review theories and discuss affects and mood as criteria For depression or mania diagnosis. Results: Our work was to show that mood and affections are poorly conceived. Conclusions: Mood and affection do not serve as a basis for the diagnosis of depression or mania.

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While it has been clearly demonstrated that smoking is the most significant exogenous factor involved in oral carcinogenesis, little is known about the global molecular and cellular changes that occur prior to the appearance of clinically detectable symptoms. Thus, the aim of this study was to investigate the expressivity of bcl-2, bax and PCNA in the rat tongue mucosa exposed to cigarette smoke by means of immunohistochemistry. A total of twelve male Wistar rats were distributed into 2 groups: negative control and experimental group exposed to cigarette smoke during 75 days. After experimental period, no histopathological changes in the tongue mucosa were detected in the negative control and the experimental group. on the other hand, an overexpression of bcl-2 was detected (p < 0.01) throughout all layers of the epithelium, whereas bax did not show significant differences (p > 0.05). Also, the labeling index for bcl-2 and bax showed an increase 75 days after cigarette exposure (p < 0.01). PCNA-labeling index did not show remarkable changes between groups. Taken together, our results show that bcl-2 is overexpressed in the rat tongue keratinocytes after cigarette smoke exposure.

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Background: Very limited information is available from in vivo studies about whether smoking and/or nicotine affect gingival tissues in the absence of plaque. The purpose of this study is to evaluate the effect of the systemic administration of nicotine in the proliferation and counting of fibroblast-like cells in the gingival tissue of rats.Methods: Thirty adult male Wistar rats were randomly assigned into two groups to receive subcutaneous injections of a saline solution (control group = group C) or nicotine solution (group N; 3 mg/kg) twice a day. The animals were euthanized 37, 44, or 51 days after the first subcutaneous injection. Specimens were routinely processed for serial histologic sections. Five fields of view in the connective tissue adjacent to the gingival epithelium and above the alveolar bone crest of the maxillary first molar were selected for the counting of fibroblast-like cells. Data were statistically analyzed (P<0.05).Results: The intergroup analysis detected a lower number of fibroblast-like cells in group N compared to group C on days 37 (2.65 +/- 1.41 and 6.67 +/- 3.25, respectively), 44 (2.70 +/- 1.84 and 8.57 +/- 2.37, respectively), and 51(2.09 +/- 1.41 and 7.49 +/- 2.60, respectively) (P<0.05). The quantification of fibroblast-like cells showed no significant difference (P >0.05) in the intragroup analysis of control and nicotine throughout experimental periods. In the intergroup analysis, group N had reduced proliferating cell nuclear antigen positive fibroblasts compared to group C in all periods (P<0.05).Conclusion: The daily systemic administration of nicotine negatively affected, in vivo, the number and proliferation of fibroblast-like cells in the gingival tissue of rats. J Periodontol 2011;82:1206-1211.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Perinatal Pb exposure may modulate arterial tone through nitric oxide (NO) and cyclooxygenase products. To investigate this, Wistar dams received 1000 ppm of Pb or sodium acetate (control) in drinking water during pregnancy and lactation. Curves were constructed in phenylephrine-precontracted intact and/or denuded rings of thoracic aortas of weaned (23-day-old) male pups from their responses to N-omega-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and ACh in the absence or presence of indomethacin (10(-5)M, cyclooxygenase inhibitor) or L-NAME (3 x 10(-7)M and 3 x 10(-4)M). Blood lead concentration and systolic blood pressure (SBP) were higher in intoxicated than control pups (blood lead mu g/dl: control < 3.0, Pb 58.7 +/- 6.5*; SBP mmHg: control 111.4 +/- 2.3, Pb 135.5 +/- 2.4*). In L-NAME-treated rings maximal responses increased in Pb-exposed rats, and were higher in intact than in denuded aortas (contraction [% of phenylephrine] intact: control 184.3 +/- 23.7, Pb 289.1 +/- 18.3*; denuded: control 125.1 +/- 4.5, Pb 154.8 +/- 13.3*). ACh-induced relaxation in intact aortas from Pb-exposed rats presented rightward shift in L-NAME presence (EC50 x 10(-7)M: control 1.32 [0.33-5.18], Pb 4.88 [3.56-6.69]*) but moved left under indomethacin (EC50 x 10(-7)M: control 8.95 [3.47-23.07], Pb 0.97 [0.38-2.43]*). *p < 0.05 significant relative to the respective control; N = 7-9. Endothelium removal abolished ACh-induced relaxation. Perinatal Pb exposure caused hypertension associated with alterations in the production and/or release of basal and stimulated endothelium-derived relaxing factors-NO and constricting cyclooxygenase products. These findings may help explain the contribution of NO and cyclooxygenase products to the etiology and/or maintenance of Pb-induced hypertension and could ultimately lead to therapeutic advantages in plumbism.

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