Biological science Institute

Belo Horizonte, Brazil

Biological science Institute

Belo Horizonte, Brazil
SEARCH FILTERS
Time filter
Source Type

Nunes K.P.,Biological Science Institute | Nunes K.P.,Georgia Regents University | Cordeiro M.N.,Ezequiel Dias Foundation | Richardson M.,Ezequiel Dias Foundation | And 8 more authors.
Journal of Sexual Medicine | Year: 2010

Introduction. Priapism is one of several symptoms observed in accidental bites by the spider Phoneutria nigriventer. The venom of this spider is comprised of many toxins, and the majority has been shown to affect excitable ion channels, mainly sodium (Na+) channels. It has been demonstrated that PnTx2-6, a peptide extracted from the venom of P. nigriventer, causes erection in anesthetized rats and mice.Aim. We investigated the mechanism by which PnTx2-6 evokes relaxation in rat corpus cavernosum.Main Outcome Measures. PnTx2-6 toxin potentiates nitric oxide (NO)-dependent cavernosal relaxation.Methods. Rat cavernosal strips were incubated with bretylium (3 × 10-5 M) and contracted with phenylephrine (PE; 10-5 M). Relaxation responses were evoked by electrical field stimulation (EFS) or sodium nitroprusside (SNP) before and after 4 minutes of incubation with PnTx2-6 (10-8 M). The effect of PnTx2-6 on relaxation induced by EFS was also tested in the presence of atropine (10-6 M), a muscarinic receptor antagonist, N-type Ca2+ channel blockers (ω-conotoxin GVIA, 10-6 M) and sildenafil (3 × 10-8 M). Technetium99m radiolabeled PnTx2-6 subcutaneous injection was administrated in the penis.Results. Whereas relaxation induced by SNP was not affected by PnTx2-6, EFS-induced relaxation was significantly potentiated by this toxin as well as PnTx2-6 plus SNP. This potentiating effect was further increased by sildenafil, not altered by atropine, however was completely blocked by the N-type Ca2+ channels. High concentrated levels of radiolabeled PnTx2-6 was specifically found in the cavernosum tissue, suggesting PnTx2-6 is an important toxin responsible for P. nigriventer spider accident-induced priapism.Conclusion. We show that PnTx2-6 slows Na+ channels inactivation in nitrergic neurons, allowing Ca2+ influx to facilitate NO/cGMP signalling, which promotes increased NO production. In addition, this relaxation effect is independent of phosphodiesterase enzyme type 5 inhibition. Our data displays PnTx2-6 as possible pharmacological tool to study alternative treatments for erectile dysfunction. © 2010 International Society for Sexual Medicine.


Santos S.H.S.,Federal University of Minas Gerais | Santos S.H.S.,Laboratory of Health Science | Fernandes L.R.,Biological science Institute | Pereira C.S.,Laboratory of Health Science | And 6 more authors.
Regulatory Peptides | Year: 2012

Introduction: The aim of the present study was to evaluate the effect of a transgenic-induced chronic increase of Ang-(1-7) on the expression of inflammatory markers in adipose tissue and the metabolic profile in rats treated with high-fat diet. Research design and methods: Transgenic rats expressing an Ang-(1-7)-producing fusion protein (TGR L-3292) and Sprague Dawley (SD) control rats 4. weeks old were treated for 8. weeks with a high-fat diet. Food intake and body weight were measured once a week. Glucose-tolerance and insulin sensitivity tests were performed one week before the sacrifice. At the end of the experiment plasma lipid concentrations were measured in TGR and SD rats. Adipose tissue were weighted and corrected by the body weight. Proinflammatory markers in adipose tissue were analyzed using Western-blotting, real time-PCR and immunohistochemistry. Results: High-fat diet TGR rats presented increased HDL cholesterol levels and decreased abdominal fat mass, without changes in food intake. In addition, rats with increased Ang-(1-7) levels had lower body weight. Molecular analysis revealed decreased IL-1β and COX-2 in adipose tissue. Conclusions: Taken together, these results show that chronic high circulating angiotensin-(1-7) levels protect against metabolic stress induced by a high-fat diet decreasing the proinflammatory profile of adipose tissue. © 2012 Elsevier B.V.


Breyner N.M.,Biological science Institute | Hell R.C.R.,Biological science Institute | Carvalho L.R.P.,Biological science Institute | MacHado C.B.,Biological science Institute | And 4 more authors.
Cells Tissues Organs | Year: 2010

Cartilage tissue has a poor capacity for self-repair, especially in the case of severe cartilage damage due to trauma or age-related degeneration. Cell-based tissue engineering using scaffolds has provided an option for the repair of cartilage tissue. The present work demonstrates that a three-dimensional (3D) chitosan scaffold increases the efficiency of the adhesion and differentiation of mesenchymal stem cells (MSCs) after the addition of a chondrogenic medium. These culture conditions promoted MSC differentiation into chondrocytes during the first 9 weeks of monolayer or 3D culture in a scaffold composed of chitosan or chitosan/gelatin. The results demonstrated that a chitosan scaffold caused a reduction in alkaline phosphatase production and an increase in the collagen concentration indicating phenotypic changes in the cells. In support of these results, the production of collagen type II by the MSCs cultured in the chitosan scaffold increased after 3 weeks of culture, indicating the beginning of differentiation. However, the addition of gelatin to the chitosan scaffold did not improve on the results obtained with chitosan alone. These results suggest that this 3D chitosan scaffold is a promising candidate for biomaterial implants designed to promote MSC colonization and has applications in regenerative medicine. Copyright © 2009 S. Karger AG, Basel.


Guimaraes P.S.,Biological Science Institute | Oliveira M.F.,Biological Science Institute | Braga J.F.,Biological Science Institute | Nadu A.P.,Biological Science Institute | And 3 more authors.
Hypertension | Year: 2014

We evaluated effects of chronic intracerebroventricular infusion of angiotensin (Ang)-(1-7) on cardiovascular and metabolic parameters in fructose-fed (FF) rats. After 6 weeks of fructose intake (10% in drinking water), Sprague-Dawley rats were subjected to intracerebroventricular infusion of Ang-(1-7) (200 ng/h; FF+A7 group) or 0.9% sterile saline (FF group) for 4 weeks with continued access to fructose. Compared with control rats, FF rats had increased mean arterial pressure and cardiac sympathetic tone with impaired baroreflex sensitivity. FF rats also presented increased circulating triglycerides, leptin, insulin, and glucose with impaired glucose tolerance. Furthermore, relative weights of liver and retroperitoneal adipose tissue were increased in FF rats. Glycogen content was reduced in liver, but increased in muscle. In contrast, fructose-fed rats subjected to chronic intracerebroventricular infusion of Ang-(1-7) presented reduced cardiac sympathetic tone with normalized mean arterial pressure, baroreflex sensitivity, glucose and insulin levels, and improved glucose tolerance. Relative weight of liver, and hepatic and muscle glycogen contents were also normalized in FF+A7 rats. In addition, FF+A7 rats had reduced mRNA expression for neuronal nitric oxide synthase and NR1 subunit of N-methyl-D-aspartate receptor in hypothalamus and dorsomedial medulla. Ang-(1-7) infusion did not alter fructose-induced hyperleptinemia and increased relative weight of retroperitoneal adipose tissue. There were no differences in body weights, neither in liver mRNA expression of phosphoenolpyruvate carboxykinase or glucose-6-phosphatase among the groups. These data indicate that chronic increase in Ang-(1-7) levels in the brain may have a beneficial role in fructose-fed rats by ameliorating cardiovascular and metabolic disorders. © 2014 American Heart Association, Inc.


Gomes C.C.,Biological science Institute | Diniz M.G.,Federal University of Minas Gerais | De Menezes G.H.F.,Federal University of Minas Gerais | Castro W.H.,Federal University of Minas Gerais | Gomez R.S.,Federal University of Minas Gerais
Pediatrics | Year: 2015

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that primarily affects the maxilla of infants during their first year of life. Complete resection is the conventional treatment and recurrence rates vary from 10% to 60%. The recurrent tumors grow more aggressively and can invade other anatomic structures, such as the nasal cavity, the orbit, and the skull base. The aggressive behavior of MNTIs may require radical resection, which may not be possible in some cases because of its rapid and invading growth together with invasion of vital structures. In these situations, adjunct radiotherapy or chemotherapy has been used. However, as there are no conclusive data regarding the molecular profile of this tumor, currently there is no targeted therapy that may be used in the treatment of selected aggressive cases. On the basis of MNTI similarities with melanomas, such as derivation from the neural crest cells and presence of large melanin-containing cells, we hypothesized that MNTIs also may harbor the BRAFV600E oncogenic mutation. We show for the first time that this important pediatric tumor may harbor the oncogenic BRAFV600E mutation, providing the first insights to their personalized treatment. © 2015 by the American Academy of Pediatrics.


Batista N.V.,Biological science Institute | Pereira R.V.S.,Biological science Institute | Noviello M.L.M.,Biological science Institute | Dourado L.P.A.,Biological science Institute | And 5 more authors.
Clinical and Experimental Immunology | Year: 2014

The prevalence of food allergy is rising in the western world. Allergen restriction is the chosen treatment in this condition, but continuous ingestion of the antigen has shown positive results in clinical trials. In a previous study, we have shown several allergic and metabolic alterations after 7 days of ovalbumin (OVA) ingestion by sensitized mice. The aim of this study was to investigate whether prolonged ingestion of antigen by sensitized mice would reverse the metabolic consequences caused by experimental food allergy. For this, allergic and metabolic parameters were analysed after prolonged ingestion of an OVA diet by OVA-sensitized mice. As shown previously, after 7 days of OVA consumption, sensitized mice showed increased serum levels of anti-OVA immunoglobulin (Ig)E and IgG1, aversion to the antigen ingestion, marked body and adipose tissue weight loss, followed by adipose tissue inflammation and decreased serum levels of adipokines, glucose and triglycerides. However, after 14 days of oral challenge, sensitized mice showed an anti-OVA IgE level similar to the mice that were only sensitized, but the specific IgG1 did not change. With this prolonged ingestion of OVA, sensitized mice were protected from OVA-induced anaphylaxis when the antigen was given systemically at a dose of 2mg/animal. Moreover, various parameters analysed were significantly ameliorated, including adipose tissue inflammation, body and adipose tissue loss, as well as serum levels of adipokines and triglycerides. Therefore, our data suggest that prolonged ingestion of OVA by sensitized mice results in an improvement of the metabolic consequences caused by experimental food allergy. © 2014 British Society for Immunology.


Costa E.L.O.,Federal University of Minas Gerais | de Azevedo G.M.,Biological science Institute | Petroianu A.,Federal University of Minas Gerais
Acta Cirurgica Brasileira | Year: 2014

PURPOSE: To investigate the effects of ileal exclusion on hepatic and renal morphology in extra-hepatic cholestasis. METHODS: Twenty four rats were distributed into three groups. Group 1 (control) underwent laparotomy and laparorrhaphy. The animals in groups 2 and 3 underwent hepatic duct ligature and kept in cholestasis for four weeks. After this period, the rats in groups 2 and 3 underwent internal biliary derivation. In Group 3, the last ten centimeters of the terminal ileum were by passed and excluded. Four weeks later, histological and biochemical analysis were performed in all animals of the three groups. RESULTS: In Group 1, no abnormalities regarding hepatic morphology were observed. All animals from groups 2 and 3 presented hepatic fibrosis. No difference was observed between the two groups. No morphological differences in renal histology could be identified among the three groups. There were differences in AST (p<0.05), ALT (p<0.05), direct bilirubin (p<0.05), ƔGT (p<0.05), urea (p<0.05) and creatinine (p<0.05) in Group 3 compared to control. CONCLUSION: The distal ileum exclusion had no influence upon the hepatic and renal morphological alterations, and biochemical liver and kidney tests have worsened. © 2014 Morphological changes in the liver and kidneys of rats subjected to terminal ileum exclusion during obstructive cholestasis. All rights reserved.


Lucena-Silva N.,Aggeu Magalhaes Research Center | De Souza V.S.B.,Virology Division | Gomes R.G.,Aggeu Magalhaes Research Center | Fantinatti A.,University of Sao Paulo | And 8 more authors.
Journal of Rheumatology | Year: 2013

Objective. HLA-G has well recognized tolerogenic properties in physiological and nonphysiological conditions. The 3' untranslated region (3'UTR) of the HLA-G gene has at least 3 polymorphic sites (14-bpINS/DEL, +3142C/G, and +3196C/G) described as associated with posttranscriptional influence on messenger RNA production; however, only the 14-bpINS/DEL and +3142C/G sites have been studied in systemic lupus erythematosus (SLE). Methods. We investigated the HLA-G 3'UTR polymorphic sites (14-bpINS/DEL, +3003C/T, +3010C/G, +3027A/C, +3035C/T, +3142C/G, +3187A/G, and +3196C/G) in 190 Brazilian patients with SLE and 282 healthy individuals in allele, genotype, and haplotype analyses. A multiple logistic regression model was used to assess the association of the disease features with the HLA-G 3'UTR haplotypes. Results. Increased frequencies were observed of the 14-bpINS (p = 0.053), +3010C (p = 0.008), +3142G (p = 0.006), and +3187A (p = 0.013) alleles, and increased frequencies of the 14-bpINS-INS (p = 0.094), +3010 C-C (p = 0.033), +3142 G-G (p = 0.021), and +3187 A-A (p = 0.035) genotypes. After Bonferroni correction, only the +3142G (p = 0.05) and +3010C (p = 0.06) alleles were overrepresented in SLE patients. The UTR-1 haplotype (14-bpDEL/+3003T/+3010G/ +3027C/+3035C/ +3142C/+3187G/+3196C) was underrepresented in SLE (pcorr = 0.035). Conclusion. These results indicate that HLA-G 3'UTR polymorphic sites, particularly +3142G and +3010C alleles, were associated with SLE susceptibility, whereas UTR-1 was associated with protection against development of SLE. Copyright © 2013 Journal of Rheumatology. All rights reserved.


PubMed | Biological science Institute
Type: Journal Article | Journal: Clinical and experimental immunology | Year: 2014

The prevalence of food allergy is rising in the western world. Allergen restriction is the chosen treatment in this condition, but continuous ingestion of the antigen has shown positive results in clinical trials. In a previous study, we have shown several allergic and metabolic alterations after 7 days of ovalbumin (OVA) ingestion by sensitized mice. The aim of this study was to investigate whether prolonged ingestion of antigen by sensitized mice would reverse the metabolic consequences caused by experimental food allergy. For this, allergic and metabolic parameters were analysed after prolonged ingestion of an OVA diet by OVA-sensitized mice. As shown previously, after 7 days of OVA consumption, sensitized mice showed increased serum levels of anti-OVA immunoglobulin (Ig)E and IgG1, aversion to the antigen ingestion, marked body and adipose tissue weight loss, followed by adipose tissue inflammation and decreased serum levels of adipokines, glucose and triglycerides. However, after 14 days of oral challenge, sensitized mice showed an anti-OVA IgE level similar to the mice that were only sensitized, but the specific IgG1 did not change. With this prolonged ingestion of OVA, sensitized mice were protected from OVA-induced anaphylaxis when the antigen was given systemically at a dose of 2 mg/animal. Moreover, various parameters analysed were significantly ameliorated, including adipose tissue inflammation, body and adipose tissue loss, as well as serum levels of adipokines and triglycerides. Therefore, our data suggest that prolonged ingestion of OVA by sensitized mice results in an improvement of the metabolic consequences caused by experimental food allergy.


PubMed | Biological Science Institute
Type: Journal Article | Journal: The journal of sexual medicine | Year: 2010

Priapism is one of several symptoms observed in accidental bites by the spider Phoneutria nigriventer. The venom of this spider is comprised of many toxins, and the majority has been shown to affect excitable ion channels, mainly sodium (Na(+) ) channels. It has been demonstrated that PnTx2-6, a peptide extracted from the venom of P. nigriventer, causes erection in anesthetized rats and mice.We investigated the mechanism by which PnTx2-6 evokes relaxation in rat corpus cavernosum.PnTx2-6 toxin potentiates nitric oxide (NO)-dependent cavernosal relaxation.Rat cavernosal strips were incubated with bretylium (3 10(-5) M) and contracted with phenylephrine (PE; 10(-5) M). Relaxation responses were evoked by electrical field stimulation (EFS) or sodium nitroprusside (SNP) before and after 4 minutes of incubation with PnTx2-6 (10(-8) M). The effect of PnTx2-6 on relaxation induced by EFS was also tested in the presence of atropine (10(-6) M), a muscarinic receptor antagonist, N-type Ca(2+) channel blockers (-conotoxin GVIA, 10(-6) M) and sildenafil (3 10(-8) M). Technetium99m radiolabeled PnTx2-6 subcutaneous injection was administrated in the penis.Whereas relaxation induced by SNP was not affected by PnTx2-6, EFS-induced relaxation was significantly potentiated by this toxin as well as PnTx2-6 plus SNP. This potentiating effect was further increased by sildenafil, not altered by atropine, however was completely blocked by the N-type Ca(2+) channels. High concentrated levels of radiolabeled PnTx2-6 was specifically found in the cavernosum tissue, suggesting PnTx2-6 is an important toxin responsible for P. nigriventer spider accident-induced priapism.We show that PnTx2-6 slows Na(+) channels inactivation in nitrergic neurons, allowing Ca(2+) influx to facilitate NO/cGMP signalling, which promotes increased NO production. In addition, this relaxation effect is independent of phosphodiesterase enzyme type 5 inhibition. Our data displays PnTx2-6 as possible pharmacological tool to study alternative treatments for erectile dysfunction.

Loading Biological science Institute collaborators
Loading Biological science Institute collaborators