Biological differences between reflux stimulated proliferative stomal lesions and N-methyl-N '-nitro-N-nitrosoguanidine induced carcinomas in Wistar rats.

The morphology and evolution of epithelial lesions that developed at a gastrojejunal stoma due to reflux of duodenal contents were compared with MNNG-induced carcinomas in the pyloric mucosa of rats in a long term experiment. Random bred male Wistar rats were given MNNG in drinking water (100 mg/l) for 12 weeks and then one group was submitted to a gastrojejunal anastomosis at the greater curvature in the oxyntic mucosa, Untreated rats underwent either gastrojejunostomy or gastrotomy. The animals were killed at the 24th and 66th weeks of the experiment. The lesions obtained in the pyloric mucosa and in the mucosa of the gastrojejunal stoma were analyzed histologically using hematoxylin and eosin staining and immunohistochemistry for pepsinogen isoenzyme 1. Duodenal reflux induced proliferative lesions at the gastrojejunal junction that increased in incidence and size with time. Histologically they consisted of benign epithelial proliferation of gastric type. No evidence of malignant transformation within the gastric components of the proliferative lesions at the gastrojejunal stoma was observed even at the 66th week, Adenocarcinomas induced by MNNG in the pyloric mucosa increased in size during the experiment and were morphologically and histochemically distinct from the proliferative lesions at the gastrojejunal junction. In conclusion, proliferative lesions at the gastrojejunal stoma stimulated by duodenal reflux are biologically distinct from adenocarcinomas induced by MNNG in the pyloric mucosa. They do not seem to be precursor lesions of gastric carcinogenesis, as they do not undergo malignant transformation even after long-term, up to 66 weeks, follow-up. (C) 1999 Elsevier B.V. Ireland Ltd. All rights reserved.

Effect of alveolex on the bone defects repair stimulated by rhBMP-2: Histomorphometric study

OBJECTIVE: The aim of this study was to evaluate histomorphometrically the effect of alveolex (Propolis 10%) on the repair of bone cavities in the calvaria of rats. MATERIALS and METHODS: A 5 mm diameter bone defect was made in the calvaria of male Wistar rats using the drill-type trephine. The defects were filled with rhBMP-21Alveolex, rhBMP-2, Alveolex, or coagulum. Twenty-eight animals with seven subjects on each were sacrificed 30 days after surgery and samples were fixed and embedded in paraffin. Histological sections stained by HE (hematoxylin and eosin) were obtained from the calvaria bone defect and analyzed by a differential point-counting method. RESULTS: Group I and II, rhBMP-21Alveolex and rhBMP-2, respectively, presented higher levels of newly formed bone than other groups (P < 0.001). There were not significant differences between groups I and II (P > 0.05). In addition, there was not significant difference between groups III and IV, Control-Coagulum and Alveolex, respectively (P > 0.05). CONCLUSION: Alveolex has increased the bone repair in calvaria defects of rats when associated to rhBMP-2, however without significant differences for rhBMP-2 isolated group; Alveolex isolated group showed the lowest levels of newly formed bone with no significant differences to coagulum group (control). Microsc. Res. Tech. 75: 36-41, 2012. (C) 2011 Wiley Periodicals, Inc.

Mineral trioxide aggregate but not light-cure mineral trioxide aggregate stimulated mineralization

The purpose of this study was to evaluate the subcutaneous response of rat connective tissue to light-cure MTA and Angelus MTA. These materials were placed in polyethylene and dentin tubes and implanted into dorsal connective tissue of Wistar rats for 30 and 60 days. The specimens were prepared to be stained with hematoxylin-eosin, Von Kossa, and without stain for polarized light and evaluated in an optic microscope. The Angelus MTA showed a mild inflammatory response at 30 days and none at 60 days, characterized by organized connective tissue, presence of some chronic inflammatory cells, and induction of mineralized tissue formation. Light-cure MTA presented a moderate chronic inflammatory response at 30 days that decreased at 60 days but was more intense than with Angelus MTA and without dystrophic calcifications. It was possible to conclude that light-cure MTA was similar to MTA at 60 days, but it did not stimulate mineralization.

A Mineral Trioxide Aggregate Sealer Stimulated Mineralization

The aim of this study was to evaluate the rat subcutaneous tissue response to implanted polyethylene tubes filled with Endo-CPM-Sealer (Portland Cement Modified Sealer) (EGEO S.R.L., Buenos Aires, Argentina) compared with Sealapex (SybronEndo, Glendora, CA) and Angelus MTA (Angelus, Londrina, Brazil). These materials were placed in polyethylene and dentin tubes and implanted into dorsal connective tissue of Wistar rats for 7, 15, 30, 60, and 90 days. The specimens were prepared to be stained with hematoxylin and eosin or Von Kossa or not stained for polarized light. Qualitative and quantitative evaluations of the reaction were performed. Both materials caused mild to moderate reactions at 7 days that decreased with time. The response was similar to the control on the 30th day with Endo-CPM-Sealer and Angelus MTA and on the 60th day with Sealapex. Mineralization and granulations birefringent to the polarized light were observed with all materials. it was possible to conclude that Endo-CPM-Sealer was biocompatible and stimulated mineralization. (J Endod 2009;35:256-260)

Tumor Necrosis Factor alpha and Interleukin-1 beta Modulate Calcium and Nitric Oxide Signaling in Mechanically Stimulated Osteocytes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Correlation between Clinical/Radiographic Features and Inflammatory Cytokine Networks Produced by Macrophages Stimulated with Endodontic Content

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

Activation of serotonergic 5-HT1A receptors in the lateral parabrachial nucleus increases NaCl intake

Previous studies using non-specific serotonergic agonists and antagonists have shown the importance of serotonergic inhibitory mechanisms in the lateral parabrachial nucleus (LPBN) for controlling sodium and water intake. In the present study, we investigated whether the serotonergic 5-HTIA receptor subtype in the LPBN participates in this control. Male Holtzman rats had cannulas implanted bilaterally into the LPBN. Bilateral injections of the 5-HTIA receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT, 0.1, 1.25, and 2.5 mu g/ 0.2 mu l), into the LPBN enhanced 0.3 M NaCl and water intake of rats injected subcutaneously with the diuretic furosemide (10 mg/kg bw) and a low dose of the angiotensin-converting enzyme inhibitor, captopril (5 mg/kg bw). The increase in NaCl intake produced by 8-OH-DPAT injections was reduced in dose-related manner by pre-treating the LPBN with the selective 5-HTIA serotonergic antagonist, WAY-100635 (WAY, I and 2 mu g/0.2 mu l). In contrast, WAY did not affect water intake produced by 8-OH-DPAT. WAY-100635 injected alone into the LPBN had no effect on NaCl ingestion. Injections of 8-OH-DAPT (0.1 mu g/0.2 mu l) into the LPBN also increased 0.3 M NaCl intake induced by 24-h sodium depletion (furosemide, 20 mg/kg bw plus 24 h of sodium-free diet). Serotonin (5-HT, 20 mu g/0.2 mu l) injected alone or combined with 8-OH-DPAT into the LPBN reduced 24-h sodium depletion-induced 0.3 M NaCl intake. Therefore, the activation of serotonergic 5-HTIA receptors in the LPBN increases stimulated hypertonic NaCl and water intake, while 5-HT injections into the LPBN reduce NaCl intake and prevent the effects of serotonergic 5-HTIA receptor activation. (c) 2005 Elsevier B.V. All rights reserved.

Water deprivation and the double- depletion hypothesis: common neural mechanisms underlie thirst and salt appetite

Water deprivation-induced thirst is explained by the double-depletion hypothesis, which predicts that dehydration of the two major body fluid compartments, the extracellular and intracellular compartments, activates signals that combine centrally to induce water intake. However, sodium appetite is also elicited by water deprivation. In this brief review, we stress the importance of the water-depletion and partial extracellular fluid-repletion protocol which permits the distinction between sodium appetite and thirst. Consistent enhancement or a de novo production of sodium intake induced by deactivation of inhibitory nuclei (e.g., lateral parabrachial nucleus) or hormones (oxytocin, atrial natriuretic peptide), in water-deprived, extracellular-dehydrated or, contrary to tradition, intracellular-dehydrated rats, suggests that sodium appetite and thirst share more mechanisms than previously thought. Water deprivation has physiological and health effects in humans that might be related to the salt craving shown by our species.

Purinergic mechanisms of lateral parabrachial nucleus facilitate sodium depletion-induced NaCl intake

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

Effects of Coccoloba uvifera L. on UV-stimulated melanocytes

Exposure to ultraviolet (UV) radiation induces generation of reactive oxygen species, production of proinflammatory cytokines and melanocyte-stimulating hormone (MSH) as well as increase in tyrosinase activity. The potential photoprotective effects of Coccoloba uvifera extract (CUE) were evaluated in UV-stimulated melanocytes.Human epidermal melanocytes were used as an in vitro model to evaluate the effects of CUE on the production interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), and alpha-MSH under basal and UV-stimulated conditions. Antioxidant and anti-tyrosinase activities were also evaluated in membrane lipid peroxidation and mushroom tyrosinase assay, respectively.Coccoloba uvifera L. showed antioxidant and anti-tyrosinase activities and also inhibited the production of IL-1 alpha, TNF-alpha and alpha-MSH in melanocytes subjected to UV radiation (P < 0.01). Moreover, CUE inhibited the activity of tyrosine kinase in cell culture under basal and UV radiation conditions (P < 0.001), corroborating the findings of the mushroom tyrosinase assay.This study supports the photoprotective potential of CUE.

Review of the large catfish fisheries in the upper Amazon and the stock depletion of piraiba (Brachyplatystoma filamentosum Lichtenstein)

In this paper we describe the present status of the large migratory catfish fisheries in the Upper Amazon. We present biological information about the main species and we give strong evidence that the stock of piraiba (Brachyplatystoma filamentosum), the largest catfish in the Amazon Basin is probably over-exploited. In conclusion, we raise some hypotheses about the causes and prospects for the future.

Calculation of the vacuum pressure gradient in field emission displays

The usual design of field-emission displays (FEDs) often results in high vacuum pressure gradients inside the glass plates of the device, and this is the main limitation to the widespread availability of large area FEDs. In this paper, we perform theoretical calculations using the finite element method for determining the pressure distributions in several pumping configurations, including a new FED configuration known as porous FED or pFED. The approach here is capable of clarifying the design issues influencing the final pressure relevant to the field-emission display devices. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Contrasting continuous emission versus freeze-out via HDT

The effect of continuous emission hypothesis on the two-pion Bose-Einstein correlation is discussed and compared with the corresponding results based on the usual freeze-out ansatz. Sizable differences in the correlation function are observed when comparing these two scenarios of the decoupling process. They could lead to entirely different interpretation of properties of the hot matter formed in high-energy heavy-ion collisions.

Morphology and Blue Photoluminescence Emission of PbMoO4 Processed in Conventional Hydrothermal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structural XANES characterization of Ca0.99Sm0.01TiO3 perovskite and correlation with photoluminescence emission

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