Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 49
Filtrer
1.
Radiography (Lond) ; 28(2): 333-339, 2022 05.
Article de Anglais | MEDLINE | ID: mdl-34565679

RÉSUMÉ

INTRODUCTION: Digital Mammography (DM-2D) and more recently Digital Breast Tomosynthesis (DBT), are two of the most effective imaging modalities for breast cancer detection, often used in screening programmes. It may happen that exams using these two imaging modalities are inadvertently performed to pregnant women. The objective of this study is to assess the dose in the uterus due to DM-2D and DBT exams, according to two main irradiation scenarios: in the 1st scenario the exposure parameters were pre-selected directly by the imaging system, while in the 2nd scenario, the maximum exposure parameters were chosen. METHODS: The mammography equipment used was a Siemens Mammomat Inspiration. A physical anthropomorphic phantom, PMMA plates (simulating a breast thickness of 6 cm) and thermoluminescent dosimeters (TLDs) were used to measure entrance air kerma values on the phantom's breast and abdomen in order to successively estimate the mean glandular dose (MGD) and the dose in the uterus. For the two irradiation scenarios chosen, two-breast imaging modalities were selected: 1) DBT in Cranio-Caudal (CC) view (with 28 kV and 160 mAs as exposure parameters), 2) DBT and DM in Medio Lateral-Oblique (MLO) and CC views (with 34 kV and 250 mAs as exposure parameters). RESULTS: In the 1st scenario, the TLD measurements did not detect significant dose values in the abdomen whereas the MGD estimated using the D.R. Dance model was in close agreement with data available in the literature. In the 2nd scenario, there was no significant difference in MGD estimation between the different views, whereas the air kerma values in the abdomen (in DBT mode, CC and MLO) were 0.049 mGy and 0.004 mGy respectively. In CC DM-2D mode the abdomen air kerma value was 0.026 mGy, with no significant detected value in MLO view. CONCLUSIONS: For the dose in the uterus, the obtained values seem to indicate that DM-2D and DBT examinations inadvertently performed during pregnancy do not pose a significant radiological risk, even considering the case of overexposure in both breasts. IMPLICATIONS FOR PRACTICE: The accurate knowledge of the doses in DM-2D and DBT will contribute to raise the awareness among medical practitioners involved in breast imaging empowering them to provide accurate information about dose levels in the uterus, improving their radiation risk communication skills and consequently helping to reduce the anxiety of pregnant women undergoing this type of examinations.


Sujet(s)
Région mammaire , Mammographie , Région mammaire/imagerie diagnostique , Femelle , Humains , Mammographie/méthodes , Fantômes en imagerie , Grossesse , Dose de rayonnement , Utérus/imagerie diagnostique
2.
J Nutr Health Aging ; 25(6): 748-750, 2021.
Article de Anglais | MEDLINE | ID: mdl-34179928

RÉSUMÉ

OBJECTIVES: The aim of this study was to assess the association between the extracellular water/total body weight ratio (ECW/TBW) and SARC-F scores among elderly gastrointestinal cancer patients. MEASUREMENTS: A cross-sectional study was performed with 57 older male patients with gastrointestinal cancer. Muscle function was assessed using the SARC-F questionnaire. Total body water (TBW) and extracellular water (ECW) were determined using bioelectrical impedance analysis, and fluid retention was assessed as the ratio of ECW to TBW (ECW/TBW). Pearson´s correlation analysis was used to assess the relationship between the SARC-F score and ECW/TBW, TBW and water intake. Results were considered significant at p < 0.05. RESULTS: Of the 57 older patients evaluated (65 ± 7 y), 13 ± 8% presented severe weight loss in the last 6 months. The median SARC-F score was 1.0 (0-10), and only four patients had SARC-F ≥4, which indicates the risk of sarcopenia. There was a positive correlation between the SARC-F score and ECW/TBW (r = 0.26, p = 0.02). However, no correlation was found between daily water intake or TBW and the SARC-F score. CONCLUSION: In older gastrointestinal cancer outpatients, we found a positive, albeit low, correlation between the SARC-F score and the ECW/TBW ratio. This outcome indicates the likelihood of muscle function loss due to accumulation of extracellular fluid.


Sujet(s)
Tumeurs gastro-intestinales , Patients en consultation externe , Sujet âgé , Composition corporelle , Études transversales , Impédance électrique , Humains , Mâle , Adulte d'âge moyen
3.
Res Vet Sci ; 131: 222-231, 2020 Aug.
Article de Anglais | MEDLINE | ID: mdl-32413795

RÉSUMÉ

Skin lesions are normal to all species, regardless of gender or age. The skin, the largest organ of the body, has function as a primary barrier to the chemical, physical and biological aggressions of the environment. In animals, these lesions may be due to fights and/or predations, also as in humans, there is a very common cause of dermal lesions that are caused by burns and carcinomas. Looking for new techniques of tissue bioengineering, studies have been shown promising results for formulations of acellular biological scaffolds from tissue decellularization for the reconstitution of these lesions. The decellularization has its proof by a varied range of tests such as scanning electron microscopy and residual genomic DNA tests. Subsequently the tissue can go through the process of recellularization using cells of interest, even the animal that will receive this tissue, reducing the risks of rejection and improving the response to tissue transplantation. Thus, this manuscript aimed at the decellularization of the tissue with the use of chemical and physical means followed by sterilization and the establishment of a protocol for the recellularization of a decellularized scaffold from the Wistar rat dermis using murine fibroblasts and mesenchymal stem cells from canine adipose tissue for 7 days. After efficacy tests, the tissue recellularization were confirmed by immunofluorescence assays and scanning electron microscopy where the adherence of the cells in the biological scaffold was observed.


Sujet(s)
Derme , Fibroblastes/physiologie , Cellules souches mésenchymateuses/physiologie , Ingénierie tissulaire/méthodes , Structures d'échafaudage tissulaires , Animaux , Chiens , Souris , Rats , Rat Wistar
4.
Clin Exp Immunol ; 189(3): 318-330, 2017 09.
Article de Anglais | MEDLINE | ID: mdl-28542701

RÉSUMÉ

Forkhead box P3 (FoxP3)+ regulatory T cells (Tregs ) are functionally deficient in systemic lupus erythematosus (SLE), characterized by reduced surface CD25 [the interleukin (IL)-2 receptor alpha chain]. Low-dose IL-2 therapy is a promising current approach to correct this defect. To elucidate the origins of the SLE Treg phenotype, we studied its role through developmentally defined regulatory T cell (Treg ) subsets in 45 SLE patients, 103 SLE-unaffected first-degree relatives and 61 unrelated healthy control subjects, and genetic association with the CD25-encoding IL2RA locus. We identified two separate, uncorrelated effects contributing to Treg CD25. (1) SLE patients and unaffected relatives remarkably shared CD25 reduction versus controls, particularly in the developmentally earliest CD4+ FoxP3+ CD45RO- CD31+ recent thymic emigrant Tregs . This first component effect influenced the proportions of circulating CD4+ FoxP3high CD45RO+ activated Tregs . (2) In contrast, patients and unaffected relatives differed sharply in their activated Treg CD25 state: while relatives as control subjects up-regulated CD25 strongly in these cells during differentiation from naive Tregs , SLE patients specifically failed to do so. This CD25 up-regulation depended upon IL2RA genetic variation and was related functionally to the proliferation of activated Tregs , but not to their circulating numbers. Both effects were found related to T cell IL-2 production. Our results point to (1) a heritable, intrathymic mechanism responsible for reduced CD25 on early Tregs and decreased activation capacity in an extended risk population, which can be compensated by (2) functionally independent CD25 up-regulation upon peripheral Treg activation that is selectively deficient in patients. We expect that Treg -directed therapies can be monitored more effectively when taking this distinction into account.


Sujet(s)
Famille , Sous-unité alpha du récepteur à l'interleukine-2/génétique , Lupus érythémateux disséminé/immunologie , Lymphocytes T régulateurs/immunologie , Adulte , Sujet âgé , Femelle , Cytométrie en flux , Humains , Interleukine-2/biosynthèse , Interleukine-2/immunologie , Sous-unité alpha du récepteur à l'interleukine-2/immunologie , Antigènes CD45/génétique , Antigènes CD45/immunologie , Antigènes CD45/métabolisme , Lupus érythémateux disséminé/physiopathologie , Activation des lymphocytes/immunologie , Mâle , Adulte d'âge moyen , Phénotype , Lymphocytes T régulateurs/classification , Régulation positive , Jeune adulte
5.
Braz J Biol ; 75(3): 718-25, 2015 Aug.
Article de Anglais | MEDLINE | ID: mdl-26465732

RÉSUMÉ

The species of the genus Smilax, popularly known as sarsaparilla, are widely used in folk medicine due to the antirheumatic properties of its underground structures. Smilax fluminensis and S. syphilitica occur in forested areas and form thickened stems called rhizophores from which adventitious roots grow. To provide information for more accurate identification of the commercialised product and for elucidating the process of stem thickening, a morphology and anatomy study of the underground organs of the two species was conducted. The adventitious roots differ in colour and diameter depending on the stage of development. They are white and have a larger diameter in the early stages of development, but as they grow, the adventitious roots become brown and have a smaller diameter due to the disintegration of the epidermis and virtually the entire cortex. In brown roots, the covering function is then performed by the lignified endodermis and the remaining walls of the cells from the last parenchyma cortical layer. These results are similar to those found in studies of other Smilax and suggest that the anatomy of the roots can be useful for identifying fraud in commercialised materials. The thickening process of the nodal regions of the rhizophores in both species involves the activity of axillary buds and pericyclic layers.


Sujet(s)
Smilax/anatomie et histologie , Brésil , Racines de plante/anatomie et histologie
6.
Neuroscience ; 296: 55-65, 2015 Jun 18.
Article de Anglais | MEDLINE | ID: mdl-25827498

RÉSUMÉ

What do animals hear? While it remains challenging to adequately assess sensory perception in animal models, it is important to determine perceptual abilities in model systems to understand how physiological processes and plasticity relate to perception, learning, and cognition. Here we discuss hearing in rodents, reviewing previous and recent behavioral experiments querying acoustic perception in rats and mice, and examining the relation between behavioral data and electrophysiological recordings from the central auditory system. We focus on measurements of critical bands, which are psychoacoustic phenomena that seem to have a neural basis in the functional organization of the cochlea and the inferior colliculus. We then discuss how behavioral training, brain stimulation, and neuropathology impact auditory processing and perception.


Sujet(s)
Cortex auditif/physiologie , Perception auditive/physiologie , Cochlée/physiologie , Colliculus inférieurs/physiologie , Souris/physiologie , Plasticité neuronale , Rats/physiologie , Stimulation acoustique , Animaux , Voies auditives/physiologie , Modèles animaux , Masquage perceptif/physiologie
7.
Acta Biomater ; 10(7): 3145-55, 2014 Jul.
Article de Anglais | MEDLINE | ID: mdl-24650971

RÉSUMÉ

Skin regeneration remains a challenge, requiring a well-orchestrated interplay of cell-cell and cell-matrix signalling. Cell sheet (CS) engineering, which has the major advantage of allowing the retrieval of the intact cell layers along with their naturally organized extracellular matrix (ECM), has been poorly explored for the purpose of creating skin substitutes and skin regeneration. This work proposes the use of CS technology to engineer cellular constructs based on human keratinocytes (hKC), key players in wound re-epithelialization, dermal fibroblasts (hDFb), responsible for ECM remodelling, and dermal microvascular endothelial cells (hDMEC), part of the dermal vascular network and modulators of angiogenesis. Homotypic and heterotypic three-dimensional (3-D) CS-based constructs were developed simultaneously to target wound re-vascularization and re-epithelialization. After implantation of the constructs in murine full-thickness wounds, human cells were engrafted into the host wound bed and were present in the neotissue formed up to 14 days post-implantation. Different outcomes were obtained by varying the composition and organization of the 3-D constructs. Both hKC and hDMEC significantly contributed to re-epithelialization by promoting rapid wound closure and early epithelial coverage. Moreover, a significant increase in the density of vessels at day 7 and the incorporation of hDMEC in the neoformed vasculature confirmed its role over neotissue vacularization. As a whole, the obtained results confirmed that the proposed 3-D CS-based constructs provided the necessary cell machinery, when in a specific microenvironment, guiding both re-vascularization and re-epithelialization. Although dependent on the nature of the constructs, the results obtained sustain the hypothesis that different CS-based constructs lead to improved skin healing.


Sujet(s)
Néovascularisation physiologique , Réépithélialisation , Peau/cytologie , Animaux , Cellules cultivées , Humains , Hybridation in situ , Mâle , Souris , Transplantation de peau
8.
Biomacromolecules ; 14(11): 3997-4008, 2013 Nov 11.
Article de Anglais | MEDLINE | ID: mdl-24093541

RÉSUMÉ

Among the wide range of strategies to target skin repair/regeneration, tissue engineering (TE) with stem cells at the forefront, remains as the most promising route. Cell sheet (CS) engineering is herein proposed, taking advantage of particular cell-cell and cell-extracellular matrix (ECM) interactions and subsequent cellular milieu, to create 3D TE constructs to promote full-thickness skin wound regeneration. Human adipose derived stem cells (hASCs) CS were obtained within five days using both thermoresponsive and standard cell culture surfaces. hASCs-based constructs were then built by superimposing three CS and transplanted into full-thickness excisional mice skin wounds with delayed healing. Constructs obtained using thermoresponsive surfaces were more stable than the ones from standard cell culture surfaces due to the natural adhesive character of the respective CS. Both CS-generating strategies lead to prolonged hASCs engraftment, although no transdifferentiation phenomena were observed. Moreover, our findings suggest that the transplanted hASCs might be promoting neotissue vascularization and extensively influencing epidermal morphogenesis, mainly through paracrine actions with the resident cells. The thicker epidermis, with a higher degree of maturation characterized by the presence of rete ridges-like structures, as well as a significant number of hair follicles observed after transplantation of the constructs combining the CS obtained from the thermoresponsive surfaces, reinforced the assumptions of the influence of the transplanted hASCs and the importance of the higher stability of these constructs promoted by cohesive cell-cell and cell-ECM interactions. Overall, this study confirmed the potential of hASCs CS-based constructs to treat full-thickness excisional skin wounds and that their fabrication conditions impact different aspects of skin regeneration, such as neovascularisation, but mainly epidermal morphogenesis.


Sujet(s)
Tissu adipeux/cytologie , Cellules épidermiques , Morphogenèse , Cellules souches/cytologie , Ingénierie tissulaire , Cicatrisation de plaie , Tissu adipeux/composition chimique , Animaux , Cellules cultivées , Matrice extracellulaire/composition chimique , Humains , Mâle , Souris , Souris de lignée BALB C , Cellules souches/composition chimique
9.
Genet Mol Res ; 12(2): 1132-42, 2013 Apr 10.
Article de Anglais | MEDLINE | ID: mdl-23661438

RÉSUMÉ

Julocroton triqueter extracts have antileishmanial activity; however, the effect on genetic stability has not been studied. We evaluated genotoxic and cell death induction potential (in vitro and in vivo) of J. triqueter var. triqueter hydroalcoholic extracts, as well as their antigenotoxic potential in vivo. The in vitro genotoxic studies were performed using human leukocytes at four different concentrations. For the in vivo tests, Swiss mice were treated with 125, 250 or 500 mg/kg of extract injected intraperitoneally. Antigenotoxic effects of the extract were measured before and after cyclophosphamide treatment. An absence of genotoxic effects was observed both in vitro and in vivo. In the antigenotoxic studies, no significant difference was observed between the treatments and the positive control, indicating that the extracts did not protect against damage caused by cyclophosphamide. Hydroalcoholic extracts of J. triqueter did not provoke DNA damage at concentrations and doses normally used for antileishmanial treatment; however, they reduced apoptotic cell death and induced necrotic cell death.


Sujet(s)
Antiprotozoaires/toxicité , Croton/composition chimique , Leishmania/effets des médicaments et des substances chimiques , Extraits de plantes/toxicité , Animaux , Antiprotozoaires/composition chimique , Mort cellulaire/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Test des comètes , Femelle , Humains , Leucocytes/effets des médicaments et des substances chimiques , Leucocytes/métabolisme , Mâle , Souris , Tests de mutagénicité , Extraits de plantes/composition chimique
10.
Genet Mol Res ; 12(2): 1303-10, 2013 Apr 25.
Article de Anglais | MEDLINE | ID: mdl-23661453

RÉSUMÉ

The genus Smilax (Smilacaceae) includes species of medicinal interest; consequently, their identification is important for the control of raw material used in the manufacture of phytotherapeutic products. We investigated the karyotype of Smilax rufescens in order to look for patterns that would be useful for comparative studies of this genus. To accomplish this, we developed procedures to grow plants and optimize root pretreatment with mitotic fuse inhibitors to obtain metaphase spreads showing clear chromosome morphology. The karyotype, analyzed in Feulgen-stained preparations, was asymmetric, with N = 16 chromosomes gradually decreasing in size; the larger ones were subtelocentric and the smaller chromosomes were submetacentric or metacentric. Nearly terminal secondary constrictions were visualized on the short arm of chromosome pairs 7, 11, and 14, but they were clearly detected only in one of the homologues of each pair. The nucleolus organizer regions (NORs) were mapped by silver staining and fluorescent in situ hybridization of 45S rDNA probes. Silver signals (Ag-NORs) colocalized with rDNA loci were detected at the termini of the short arm of 6 chromosomes. The secondary constriction heteromorphism observed in Feulgen-stained metaphases suggests that differential rRNA gene expression between homologous rDNA loci can occur, resulting in different degrees of chromatin decondensation. In addition, a heteromorphic chromosome pair was identified and was interpreted as being a sex chromosome pair in this dioecious species.


Sujet(s)
Cartographie chromosomique , Chromosomes de plante , ADN ribosomique , Caryotype , ARN ribosomique , Smilax/génétique , Hybridation fluorescente in situ , Phénotype
11.
Braz J Med Biol Res ; 46(2): 164-70, 2013 Feb.
Article de Anglais | MEDLINE | ID: mdl-23558932

RÉSUMÉ

Myosin Va functions as a processive, actin-based motor molecule highly enriched in the nervous system, which transports and/or tethers organelles, vesicles, and mRNA and protein translation machinery. Mutation of myosin Va leads to Griscelli disease that is associated with severe neurological deficits and a short life span. Despite playing a critical role in development, the expression of myosin Va in the central nervous system throughout the human life span has not been reported. To address this issue, the cerebellar expression of myosin Va from newborns to elderly humans was studied by immunohistochemistry using an affinity-purified anti-myosin Va antibody. Myosin Va was expressed at all ages from the 10th postnatal day to the 98 th year of life, in molecular, Purkinje and granular cerebellar layers. Cerebellar myosin Va expression did not differ essentially in localization or intensity from childhood to old age, except during the postnatal developmental period. Structures resembling granules and climbing fibers in Purkinje cells were deeply stained. In dentate neurons, long processes were deeply stained by anti-myosin Va, as were punctate nuclear structures. During the first postnatal year, myosin Va was differentially expressed in the external granular layer (EGL). In the EGL, proliferating prospective granule cells were not stained by anti-myosin Va antibody. In contrast, premigratory granule cells in the EGL stained moderately. Granule cells exhibiting a migratory profile in the molecular layer were also moderately stained. In conclusion, neuronal myosin Va is developmentally regulated, and appears to be required for cerebellar function from early postnatal life to senescence.


Sujet(s)
Cervelet/métabolisme , Myosine de type V/métabolisme , Adolescent , Adulte , Facteurs âges , Sujet âgé , Sujet âgé de 80 ans ou plus , Cadavre , Enfant , Enfant d'âge préscolaire , Électrophorèse sur gel d'agar , Femelle , Humains , Immunotransfert , Immunohistochimie , Nourrisson , Nouveau-né , Mâle , Jeune adulte
12.
Braz. j. med. biol. res ; 46(2): 164-170, 01/fev. 2013. tab, graf
Article de Anglais | LILACS | ID: lil-668777

RÉSUMÉ

Myosin Va functions as a processive, actin-based motor molecule highly enriched in the nervous system, which transports and/or tethers organelles, vesicles, and mRNA and protein translation machinery. Mutation of myosin Va leads to Griscelli disease that is associated with severe neurological deficits and a short life span. Despite playing a critical role in development, the expression of myosin Va in the central nervous system throughout the human life span has not been reported. To address this issue, the cerebellar expression of myosin Va from newborns to elderly humans was studied by immunohistochemistry using an affinity-purified anti-myosin Va antibody. Myosin Va was expressed at all ages from the 10th postnatal day to the 98th year of life, in molecular, Purkinje and granular cerebellar layers. Cerebellar myosin Va expression did not differ essentially in localization or intensity from childhood to old age, except during the postnatal developmental period. Structures resembling granules and climbing fibers in Purkinje cells were deeply stained. In dentate neurons, long processes were deeply stained by anti-myosin Va, as were punctate nuclear structures. During the first postnatal year, myosin Va was differentially expressed in the external granular layer (EGL). In the EGL, proliferating prospective granule cells were not stained by anti-myosin Va antibody. In contrast, premigratory granule cells in the EGL stained moderately. Granule cells exhibiting a migratory profile in the molecular layer were also moderately stained. In conclusion, neuronal myosin Va is developmentally regulated, and appears to be required for cerebellar function from early postnatal life to senescence.


Sujet(s)
Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Nourrisson , Nouveau-né , Mâle , Jeune adulte , Cervelet/métabolisme , Myosine de type V/métabolisme , Facteurs âges , Cadavre , Électrophorèse sur gel d'agar , Immunotransfert , Immunohistochimie
13.
Neuroscience ; 231: 315-27, 2013 Feb 12.
Article de Anglais | MEDLINE | ID: mdl-23219939

RÉSUMÉ

Angiotensins (Angs) modulate blood pressure, hydro-electrolyte composition, and antinociception. Although Ang (5-8) has generally been considered to be inactive, we show here that Ang (5-8) was the smallest Ang to elicit dose-dependent responses and receptor-mediated antinociception in the rat ventrolateral periaqueductal gray matter (vlPAG). Ang (5-8) antinociception seems to be selective, because it did not alter blood pressure or act on vascular or intestinal smooth muscle cells. The non-selective Ang-receptor (Ang-R) antagonist saralasin blocked Ang (5-8) antinociception, but selective antagonists of Ang-R types I, II, IV, and Mas did not, suggesting that Ang (5-8) may act via an unknown receptor. Endopeptidase EP 24.11 and amastatin-sensitive aminopeptidase from the vlPAG catalyzed the synthesis (from Ang II or Ang III) and inactivation of Ang (5-8), respectively. Selective inhibitors of neuronal-nitric oxide (NO) synthase, soluble guanylyl cyclase (sGC) and a non-selective opioid receptor (opioid-R) inhibitor blocked Ang (5-8)-induced antinociception. In conclusion, Ang (5-8) is a new member of the Ang family that selectively and strongly modulates antinociception via NO-sGC and endogenous opioid in the vlPAG.


Sujet(s)
Angiotensine-I/pharmacologie , Guanylate cyclase/métabolisme , Monoxyde d'azote/métabolisme , Nociception/effets des médicaments et des substances chimiques , Peptides opioïdes/métabolisme , Fragments peptidiques/pharmacologie , Substance grise centrale du mésencéphale/effets des médicaments et des substances chimiques , Récepteurs cytoplasmiques et nucléaires/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Antagonistes des récepteurs aux angiotensines/pharmacologie , Animaux , Aorte/effets des médicaments et des substances chimiques , Relation dose-effet des médicaments , Rythme cardiaque/physiologie , Mâle , Contraction musculaire/effets des médicaments et des substances chimiques , Muscles lisses/effets des médicaments et des substances chimiques , Peptides opioïdes/antagonistes et inhibiteurs , Rats , Rat Wistar , Saralasine/pharmacologie , Soluble guanylyl cyclase , Téprotide/pharmacologie
14.
Braz J Biol ; 72(3): 553-62, 2012 Aug.
Article de Anglais | MEDLINE | ID: mdl-22990826

RÉSUMÉ

The Atlantic Rain forest, which is considered the second largest pluvial forest in the American continent, has had an estimated 93% of its original area destroyed. Although studies concerning the herpetofaunal diversity in this biome have been intensified in the past years, its diversity is still underestimated. The Nucleo Experimental de Iguaba Grande (NEIG) is included in an Environmental Protection Area (APA de Sapeatiba) in the Iguaba Grande municipality, Rio de Janeiro state, Brazil (22º 51' S and 42º 10' W). The goal of this study was to conduct an inventory of the reptile and amphibian species that occur in this area between July 2008 and December 2009. We recorded 19 species of amphibians (18 anurans and one caecilian) and 15 species of reptiles (three lizards, 11 snakes and one amphisbaenian). Leptodactylus latrans and L. mystacinus had the highest capture rates among amphibians captured, and among reptiles, Ameiva ameiva, Hemidactylus mabouia and Mabuya agilis had the highest capture rates. Rarefaction curves for both amphibians and reptiles did not reach the asymptote, indicating that the species richness in the NEIG is still underestimated.


Sujet(s)
Amphibiens/classification , Conservation des ressources naturelles , Reptiles/classification , Arbres , Animaux , Brésil , Densité de population , Dynamique des populations
15.
Braz J Med Biol Res ; 45(2): 163-71, 2012 02.
Article de Anglais | MEDLINE | ID: mdl-22310488

RÉSUMÉ

The objective of this study was to observe possible interactions between the renin-angiotensin and nitrergic systems in chronic hypoxia-induced pulmonary hypertension in newborn piglets. Thirteen chronically instrumented newborn piglets (6.3 ± 0.9 days; 2369 ± 491 g) were randomly assigned to receive saline (placebo, P) or the AT(1) receptor (AT(1)-R) blocker L-158,809 (L) during 6 days of hypoxia (FiO(2) = 0.12). During hypoxia, pulmonary arterial pressure (Ppa; P < 0.0001), pulmonary vascular resistance (PVR; P < 0.02) and the pulmonary to systemic vascular resistance ratio (PVR/SVR; P < 0.05) were significantly attenuated in the L (N = 7) group compared to the P group (N = 6). Western blot analysis of lung proteins showed a significant decrease of endothelial NOS (eNOS) in both P and L animals, and of AT(1)-R in P animals during hypoxia compared to normoxic animals (C group, N = 5; P < 0.01 for all groups). AT(1)-R tended to decrease in L animals. Inducible NOS (iNOS) did not differ among P, L, and C animals and iNOS immunohistochemical staining in macrophages was significantly more intense in L than in P animals (P < 0.01). The vascular endothelium showed moderate or strong eNOS and AT(1)-R staining. Macrophages and pneumocytes showed moderate or strong iNOS and AT(1)-R staining, but C animals showed weak iNOS and AT(1)-R staining. Macrophages of L and P animals showed moderate and weak AT(2)-R staining, respectively, but the endothelium of all groups only showed weak staining. In conclusion, pulmonary hypertension induced by chronic hypoxia in newborn piglets is partially attenuated by AT(1)-R blockade. We suggest that AT(1)-R blockade might act through AT(2)-R and/or Mas receptors and the nitrergic system in the lungs of hypoxemic newborn piglets.


Sujet(s)
Antagonistes du récepteur de type 1 de l'angiotensine-II/usage thérapeutique , Antihypertenseurs/usage thérapeutique , Hypertension pulmonaire/traitement médicamenteux , Hypoxie/complications , Imidazoles/usage thérapeutique , Nitric oxide synthase/effets des médicaments et des substances chimiques , Tétrazoles/usage thérapeutique , Animaux , Animaux nouveau-nés , Maladie chronique , Modèles animaux de maladie humaine , Hypertension pulmonaire/étiologie , Hypertension pulmonaire/métabolisme , Immunohistochimie , Nitric oxide synthase/métabolisme , Artère pulmonaire/effets des médicaments et des substances chimiques , Suidae , Résistance vasculaire/effets des médicaments et des substances chimiques
16.
Braz. j. med. biol. res ; 45(2): 163-171, Feb. 2012. ilus, tab
Article de Anglais | LILACS | ID: lil-614574

RÉSUMÉ

The objective of this study was to observe possible interactions between the renin-angiotensin and nitrergic systems in chronic hypoxia-induced pulmonary hypertension in newborn piglets. Thirteen chronically instrumented newborn piglets (6.3 ± 0.9 days; 2369 ± 491 g) were randomly assigned to receive saline (placebo, P) or the AT1 receptor (AT1-R) blocker L-158,809 (L) during 6 days of hypoxia (FiO2 = 0.12). During hypoxia, pulmonary arterial pressure (Ppa; P < 0.0001), pulmonary vascular resistance (PVR; P < 0.02) and the pulmonary to systemic vascular resistance ratio (PVR/SVR; P < 0.05) were significantly attenuated in the L (N = 7) group compared to the P group (N = 6). Western blot analysis of lung proteins showed a significant decrease of endothelial NOS (eNOS) in both P and L animals, and of AT1-R in P animals during hypoxia compared to normoxic animals (C group, N = 5; P < 0.01 for all groups). AT1-R tended to decrease in L animals. Inducible NOS (iNOS) did not differ among P, L, and C animals and iNOS immunohistochemical staining in macrophages was significantly more intense in L than in P animals (P < 0.01). The vascular endothelium showed moderate or strong eNOS and AT1-R staining. Macrophages and pneumocytes showed moderate or strong iNOS and AT1-R staining, but C animals showed weak iNOS and AT1-R staining. Macrophages of L and P animals showed moderate and weak AT2-R staining, respectively, but the endothelium of all groups only showed weak staining. In conclusion, pulmonary hypertension induced by chronic hypoxia in newborn piglets is partially attenuated by AT1-R blockade. We suggest that AT1-R blockade might act through AT2-R and/or Mas receptors and the nitrergic system in the lungs of hypoxemic newborn piglets.


Sujet(s)
Animaux , Antagonistes du récepteur de type 1 de l'angiotensine-II/usage thérapeutique , Hypoxie/complications , Antihypertenseurs/usage thérapeutique , Hypertension pulmonaire/traitement médicamenteux , Imidazoles/usage thérapeutique , Nitric oxide synthase/effets des médicaments et des substances chimiques , Tétrazoles/usage thérapeutique , Animaux nouveau-nés , Maladie chronique , Modèles animaux de maladie humaine , Hypertension pulmonaire/étiologie , Hypertension pulmonaire/métabolisme , Immunohistochimie , Nitric oxide synthase/métabolisme , Artère pulmonaire/effets des médicaments et des substances chimiques , Suidae , Résistance vasculaire/effets des médicaments et des substances chimiques
17.
Braz. j. med. biol. res ; 43(9): 890-898, Sept. 2010. ilus
Article de Anglais | LILACS | ID: lil-556861

RÉSUMÉ

Myosin Va is an actin-based, processive molecular motor protein highly enriched in the nervous tissue of vertebrates. It has been associated with processes of cellular motility, which include organelle transport and neurite outgrowth. The in vivo expression of myosin Va protein in the developing nervous system of mammals has not yet been reported. We describe here the immunolocalization of myosin Va in the developing rat hippocampus. Coronal sections of the embryonic and postnatal rat hippocampus were probed with an affinity-purified, polyclonal anti-myosin Va antibody. Myosin Va was localized in the cytoplasm of granule cells in the dentate gyrus and of pyramidal cells in Ammon's horn formation. Myosin Va expression changed during development, being higher in differentiating rather than already differentiated granule and pyramidal cells. Some of these cells presented a typical migratory profile, while others resembled neurons that were in the process of differentiation. Myosin Va was also transiently expressed in fibers present in the fimbria. Myosin Va was not detected in germinative matrices of the hippocampus proper or of the dentate gyrus. In conclusion, myosin Va expression in both granule and pyramidal cells showed both position and time dependency during hippocampal development, indicating that this motor protein is under developmental regulation.


Sujet(s)
Animaux , Femelle , Rats , Hippocampe/embryologie , Hippocampe/métabolisme , Myosine de type V/analyse , Gyrus denté/embryologie , Gyrus denté/métabolisme , Immunohistochimie , Myosine de type V/métabolisme , Cellules pyramidales/embryologie , Cellules pyramidales/métabolisme , Rat Wistar
18.
Braz J Med Biol Res ; 43(9): 890-8, 2010 Sep.
Article de Anglais | MEDLINE | ID: mdl-20730373

RÉSUMÉ

Myosin Va is an actin-based, processive molecular motor protein highly enriched in the nervous tissue of vertebrates. It has been associated with processes of cellular motility, which include organelle transport and neurite outgrowth. The in vivo expression of myosin Va protein in the developing nervous system of mammals has not yet been reported. We describe here the immunolocalization of myosin Va in the developing rat hippocampus. Coronal sections of the embryonic and postnatal rat hippocampus were probed with an affinity-purified, polyclonal anti-myosin Va antibody. Myosin Va was localized in the cytoplasm of granule cells in the dentate gyrus and of pyramidal cells in Ammon's horn formation. Myosin Va expression changed during development, being higher in differentiating rather than already differentiated granule and pyramidal cells. Some of these cells presented a typical migratory profile, while others resembled neurons that were in the process of differentiation. Myosin Va was also transiently expressed in fibers present in the fimbria. Myosin Va was not detected in germinative matrices of the hippocampus proper or of the dentate gyrus. In conclusion, myosin Va expression in both granule and pyramidal cells showed both position and time dependency during hippocampal development, indicating that this motor protein is under developmental regulation.


Sujet(s)
Hippocampe/embryologie , Hippocampe/métabolisme , Myosine de type V/analyse , Animaux , Gyrus denté/embryologie , Gyrus denté/métabolisme , Femelle , Immunohistochimie , Myosine de type V/métabolisme , Cellules pyramidales/embryologie , Cellules pyramidales/métabolisme , Rats , Rat Wistar
19.
Acta Biomater ; 6(11): 4314-26, 2010 Nov.
Article de Anglais | MEDLINE | ID: mdl-20601228

RÉSUMÉ

The implantation of biomaterials may elicit a host response to this foreign body, and the magnitude of that reaction depends on the host and on the implanted material. The aim of this study was to compare the inflammatory response induced by the implantation of starch-based (SPCL) scaffolds in two implantation rat models: subcutaneous (SC) and intramuscular (IM). Moreover, two methodologies, wet spinning (WS) and fibre-bonding (FB), were used to prepare the scaffolds. The short-term inflammatory/immune host reaction was assessed by SC and IM implantations in rats after 1 and 2 weeks, and the long-term host response was addressed after 8 and 12 weeks of SC implantation of both types of SPCL scaffolds in rats. After each time period, the scaffolds, surrounding tissue and nearby lymph nodes were explanted, and used for histological analysis and molecular biology evaluation. The results showed that SPCL-WS scaffolds seem to induce a slight lower inflammatory/immune reaction in both types of implantation models. Nonetheless, comparing the two models, the IM implantation resulted in a slightly higher inflammatory response than the SC implantation with early activation of the lymph nodes. The overall data suggests a good integration of the materials in the host, independently of the tissue location with a normal progress of the reaction for all the conditions.


Sujet(s)
Réaction à corps étranger/anatomopathologie , Amidon/pharmacologie , Structures d'échafaudage tissulaires/composition chimique , Animaux , Électrophorèse sur gel d'agar , Régulation de l'expression des gènes/effets des médicaments et des substances chimiques , Noeuds lymphatiques/effets des médicaments et des substances chimiques , Noeuds lymphatiques/anatomopathologie , Mâle , Muscles/effets des médicaments et des substances chimiques , Muscles/anatomopathologie , Implantation de prothèse , Rats , Rat Sprague-Dawley , Tissu sous-cutané/effets des médicaments et des substances chimiques , Tissu sous-cutané/anatomopathologie , Facteurs temps , Ingénierie tissulaire
20.
Neuroscience ; 164(3): 1263-73, 2009 Dec 15.
Article de Anglais | MEDLINE | ID: mdl-19747525

RÉSUMÉ

Endogenous angiotensin (Ang) II and/or an Ang II-derived peptide, acting on Ang type 1 (AT(1)) and Ang type 2 (AT(2)) receptors, can carry out part of the nociceptive control modulated by periaqueductal gray matter (PAG). However, neither the identity of this putative Ang-peptide, nor its relationship to Ang II antinociceptive activity was clarified. Therefore, we have used tail-flick and incision allodynia models combined with an HPLC time course of Ang metabolism, to study the Ang III antinociceptive effect in the rat ventrolateral (vl) PAG using peptidase inhibitors and receptor antagonists. Ang III injection into the vlPAG increased tail-flick latency, which was fully blocked by Losartan and CGP 42,112A, but not by divalinal-Ang IV, indicating that Ang III effect was mediated by AT(1) and AT(2) receptors, but not by the AT(4) receptor. Ang III injected into the vlPAG reduced incision allodynia. Incubation of Ang II with punches of vlPAG homogenate formed Ang III, Ang (1-7) and Ang IV. Amastatin (AM) inhibited the formation of Ang III from Ang II by homogenate, and blocked the antinociceptive activity of Ang II injection into vlPAG, suggesting that aminopeptidase A (APA) formed Ang III from Ang II. Ang III can also be formed from Ang I by a vlPAG alternative pathway. Therefore, the present work shows, for the first time, that: (i) Ang III, acting on AT(1) and AT(2) receptors, can elicit vlPAG-mediated antinociception, (ii) the conversion of Ang II to Ang III in the vlPAG is required to elicit antinociception, and (iii) the antinociceptive activity of endogenous Ang II in vlPAG can be ascribed preponderantly to Ang III.


Sujet(s)
Analgésiques/pharmacologie , Angiotensine-III/métabolisme , Nocicepteurs/effets des médicaments et des substances chimiques , Douleur/métabolisme , Substance grise centrale du mésencéphale/métabolisme , Analgésiques/métabolisme , Angiotensine-II/pharmacologie , Angiotensine-III/pharmacologie , Antagonistes des récepteurs aux angiotensines , Animaux , Modèles animaux de maladie humaine , Interactions médicamenteuses/physiologie , Voies efférentes/effets des médicaments et des substances chimiques , Voies efférentes/métabolisme , Glutamyl aminopeptidase/biosynthèse , Losartan/pharmacologie , Mâle , Microinjections , Inhibition nerveuse/effets des médicaments et des substances chimiques , Inhibition nerveuse/physiologie , Nocicepteurs/métabolisme , Oligopeptides/pharmacologie , Douleur/traitement médicamenteux , Douleur/physiopathologie , Mesure de la douleur , Seuil nociceptif/effets des médicaments et des substances chimiques , Seuil nociceptif/physiologie , Peptides/pharmacologie , Substance grise centrale du mésencéphale/effets des médicaments et des substances chimiques , Rats , Rat Wistar , Récepteurs aux angiotensines/métabolisme
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE