Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Clin Exp Immunol ; 190(1): 122-132, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28543170

RESUMO

Cardiomyopathy is the most severe outcome of Chagas disease, causing more than 12 000 deaths/year. Immune cells participate in cardiomyopathy development either by direct tissue destruction, or by driving inflammation. We have shown that CD4- CD8- [double-negative (DN)] T cells are major sources of inflammatory and anti-inflammatory cytokines, associated with the cardiac (CARD) and indeterminate (IND) forms of Chagas disease, respectively. Here, we sought to identify Trypanosoma cruzi-derived components that lead to activation of DN T cells in Chagas patients. Glycolipid (GCL), lipid (LIP) and protein-enriched (PRO) fractions derived from trypomastigote forms of T. cruzi were utilized to stimulate cells from IND and CARD patients to determine DN T cell activation by evaluating CD69 and cytokine expression. We observed that GCL, but not LIP or PRO fractions, induced higher activation of DN T cells, especially T cell receptor (TCR)-γδ DN T, from IND and CARD. GCL led to an increase in tumour necrosis factor (TNF) and interleukin (IL)-10 expression by TCR-γδ DN T cells from IND, while inducing IFN-γ expression by TCR-γδ DN T cells from CARD. This led to an increase in the ratio IFN-γ/IL-10 in TCR-γδ DN T cells from CARD, favouring an inflammatory profile. These results identify GCL as the major T. cruzi component responsible for activation of DN T cells in chronic Chagas disease, associated predominantly with an inflammatory profile in CARD, but not IND. These findings may have implications for designing new strategies of control or prevention of Chagas disease cardiomyopathy by modulating the response to GCL.


Assuntos
Antígenos de Protozoários/imunologia , Cardiomiopatias/imunologia , Doença de Chagas/imunologia , Glicolipídeos/imunologia , Inflamação/imunologia , Linfócitos T/imunologia , Trypanosoma cruzi/imunologia , Adulto , Idoso , Antígenos CD4/metabolismo , Antígenos CD8/metabolismo , Diferenciação Celular , Células Cultivadas , Citocinas/metabolismo , Progressão da Doença , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/microbiologia
2.
J Med Entomol ; 47(6): 1212-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21175074

RESUMO

The potential of Gafanhoto Park as an American cutaneous leishmaniasis (ACL) focus was evaluated by examination of sand fly vectors of the Leishmania parasite. This forest remnant is located in a periurban area of Divin6polis, Brazil, where autochthonous cases of ACL have been reported. Sand fly populations were monitored over a 2-yr period (2006-2008) by using light traps (HP and Shannon). During systematic collections with HP traps, 824 specimens in total (342 males and 482 females) of 21 species were captured. Most prevalent species were as follows: Brumptomyia brumpti (Larrouse), Lutzomyia aragaoi (Costa Lima), Lutzomyia lutziana (Costa Lima), Lutzomyia sordellii (Shannon & Del Ponte), and Lutzomyia whitmani (Antunes & Coutinho). Using Shannon traps, 257 specimens representing 15 species were collected (159 females and 98 males), with a high prevalence of L. whitmani and Lutzomyia neivai (Pinto), both vectors of Leishmania braziliensis (Vianna). To ascertain the level of natural infection, a sample of females captured in Shannon traps was assayed for the presence of Leishmania by using polymerase chain reaction-restriction fragment length polymorphism, where 39% of insects were positive. The most infected species was L. whitmani (29 sand flies; 18.2%), followed by L. neivai (21; 13.2%), Lutzomyia christenseni (Young & Duncan) (five; 3.1%), Lutzomyia pessoai (Coutinho & Barreto) (three; 1.9%), L. aragaoi (one; 0.6%), Lutzomyia fischeri (Pinto) (one; 0.6%), Lutzomyia lenti (Mangabeira) (one; 0.6%), L. lutziana (one; 0.6%), and Lutzomyia monticula (Costa Lima) (one; 0.6%). The finding of potential and incriminated vectors naturally infected with Leishmania reinforces the need of epidemiologic surveillance in the area.


Assuntos
Leishmania/isolamento & purificação , Psychodidae/parasitologia , Animais , Brasil/epidemiologia , Cidades , Ecossistema , Feminino , Umidade , Masculino , Chuva , Temperatura , Fatores de Tempo , Urbanização
3.
Vet Comp Oncol ; 14(1): 88-100, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24571435

RESUMO

The immunological biomarkers profiles were evaluated using Luminex as putative measures to monitor canine mammary carcinomas (MCs). Forty female dogs were categorized into benign mixed tumour (MC-BMT = 28) and mammary carcinoma (MC=12). The ascendant biomarker signatures were used to compare the groups. For example, a higher frequency of MC-BMT animals producing IL-6, CXCL-8 and CXCL-10 was observed, whereas for the MC group IL-2 and CXCL-8 were detected. MC-BMT animals without metastasis had an increase in the levels of IL-2, CXCL-8, CXCL-10, IL-6, TNF-α, IL-15 and a decrease in IL-10 and CXCL-8. MC-BMT animals with metastasis showed only an increase in CXCL-10 and a decrease in IL-18. After comparing the ascendant signatures following the presence of metastasis in both groups, a higher frequency of dogs exhibiting IL-10 production was observed. Pearson correlation (P = 0.0273) and receiver operating characteristic (ROC) curve analysis revealed that this pattern was associated with worse outcome and lower survival rates in MC animals.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma/veterinária , Doenças do Cão/sangue , Neoplasias Mamárias Animais/sangue , Animais , Carcinoma/sangue , Carcinoma/metabolismo , Carcinoma/patologia , Citocinas/sangue , Citocinas/genética , Citocinas/metabolismo , Doenças do Cão/metabolismo , Doenças do Cão/patologia , Cães , Feminino , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia
4.
Chest ; 114(1): 236-40, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9674475

RESUMO

OBJECTIVES: Thrombin generated at sites of vascular injury not only participates in the coagulation cascade but can also signal other events related to cell mitogenesis and migration. In this report, we investigated the effects of thrombin on the proliferation of human arterial smooth muscle cells (SMCs) in culture and its interaction with platelet-derived growth factor (PDGF). MATERIAL AND METHODS: Human arterial SMCs originated from a renal artery were grown in cell culture. The effect of thrombin on DNA synthesis was evaluated by 3H-thymidine incorporation. The effect of thrombin on inositol-phosphate formation by SMCs was also analyzed as well as the binding of PDGF AA and BB to these cells. PDGF secretion was analyzed by radioimmunoassay (RIA). RESULTS: Exposure of cultured human SMCs to thrombin caused an increased rate of DNA synthesis in a dose-response manner, with a maximal stimulatory effect at a concentration of 2.0 U/mL. Thrombin was found to increase the accumulation of inositol phosphates and to increase the production of PDGF as measured by RIA. Exposure of cells to 2.0 U/mL thrombin resulted in a strong decrease in PDGF AA binding to PDGF receptors and did not change PDGF BB binding, probably indicating that PDGF alpha-receptors could be occupied by endogenously produced PDGF A. CONCLUSION: Thrombin stimulates human vascular SMC proliferation in a dose-response way, in part by the formation of inositol phosphates. The mechanism responsible for this effect involves, at least in part, an increased endogenous synthesis of PDGF.


Assuntos
Coagulantes/farmacologia , Mitógenos/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/biossíntese , Trombina/farmacologia , Anticoagulantes/metabolismo , Becaplermina , Coagulação Sanguínea/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Coagulantes/administração & dosagem , DNA/biossíntese , Relação Dose-Resposta a Droga , Humanos , Fosfatos de Inositol/biossíntese , Mitógenos/administração & dosagem , Fator de Crescimento Derivado de Plaquetas/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-sis , Compostos Radiofarmacêuticos , Receptores do Fator de Crescimento Derivado de Plaquetas/efeitos dos fármacos , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Artéria Renal/citologia , Estimulação Química , Trombina/administração & dosagem , Timidina/metabolismo , Trítio
5.
Am J Trop Med Hyg ; 62(1): 157-61, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10761743

RESUMO

We examined intraspecific variability in the genus Rhodnius using starch gel electrophoresis of salivary heme proteins. Salivary protein profiles of 8 Rhodnius species (R. prolixus, R. robustus, R. neglectus, R. nasutus, R. ecuadoriensis, R. pallescens, R. pictipes, and R. domesticus) were compared. All species could be distinguished by this technique. The greatest protein polymorphism was found in R. ecuadoriensis, R. nasutus, R. robustus, and R. pictipes, followed by R. prolixus, R. neglectus, R. pallescens, and R. domesticus. This approach was able to distinguish R. prolixus from R. robustus and R. neglectus from R. nasutus, species with extreme phenotypical similarity.


Assuntos
Doença de Chagas/transmissão , Hemeproteínas/química , Insetos Vetores/classificação , Rhodnius/classificação , Proteínas e Peptídeos Salivares/química , Animais , Eletroforese em Gel de Amido , Hemeproteínas/genética , Hemeproteínas/metabolismo , Insetos Vetores/química , Insetos Vetores/genética , Fenótipo , Polimorfismo Genético/genética , Rhodnius/química , Rhodnius/genética , Glândulas Salivares/química , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/genética , Proteínas e Peptídeos Salivares/metabolismo , Trypanosoma cruzi/crescimento & desenvolvimento , Gravação de Videoteipe
6.
Acta Trop ; 72(1): 91-8, 1999 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9924964

RESUMO

Comparisons of electrophoretic profiles of triatomines (Panstrongylus megistus) from the Brazilian states of Bahia (BA), Minas Gerais (MG) and Santa Catarina (SC) revealed differences in the composition of the saliva between the three populations. A phenogram constructed on the basis of the most representative electrophoretic banding patterns allowed the specimens tested to be divided into two groups. The BA and SC populations could be completely separated while some individuals from MG could be placed in each group. The BA population presented fewer bands than the MG and SC ones. The populations studied also differed with regard to their degree of association with human habitations (sylvatic, peridomiciliary and/or intradomiciliary) and our results suggest that the proteinaceous composition of the saliva of the three distinct populations of triatomines could be related to the hosts each is likely to encounter.


Assuntos
Panstrongylus/química , Panstrongylus/classificação , Saliva/química , Animais , Brasil , Eletroforese em Gel de Poliacrilamida , Feminino , Masculino , Saliva/fisiologia
7.
Acta Trop ; 71(3): 285-91, 1998 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-9879737

RESUMO

Rhodnius prolixus interpopulation variability was studied based on a new approach using salivary heme proteins (nitrophorins) electrophoresis in starch gel. We compared salivary proteins profiles of R. prolixus from three different laboratory colonies from Honduras, Venezuela, Brazil and Rhodnius robustus from Venezuela, constructing a UPGMA. The Honduran and Venezuelan populations could not be distinguished from each other, but the Brazilian population was well separated from the others. The high similarity between Honduran and Venezuelan specimens lends support to current theories that the Central American populations of R. prolixus may have been introduced from a Venezuelan origin. The low polymorphism shown by the Honduran specimens is in agreement with a possible founder effect. This new approach also distinguished R. prolixus populations from R. robustus, species with extreme phenotypical similarity.


Assuntos
Hemeproteínas/isolamento & purificação , Rhodnius/classificação , Glândulas Salivares/química , Animais , Eletroforese em Gel de Amido , Variação Genética , Hemeproteínas/química , Honduras , Fenótipo , Rhodnius/genética , América do Sul , Especificidade da Espécie
8.
Braz J Med Biol Res ; 35(11): 1259-63, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12426624

RESUMO

The objective of the present study was to establish a method for quantitative analysis of von Willebrand factor (vWF) multimeric composition using a mathematical framework based on curve fitting. Plasma vWF multimers from 15 healthy subjects and 13 patients with advanced pulmonary vascular disease were analyzed by Western immunoblotting followed by luminography. Quantitative analysis of luminographs was carried out by calculating the relative densities of low, intermediate and high molecular weight fractions using laser densitometry. For each densitometric peak (representing a given fraction of vWF multimers) a mean area value was obtained using data from all group subjects (patients and normal individuals) and plotted against the distance between the peak and IgM (950 kDa). Curves were constructed for each group using nonlinear fitting. Results indicated that highly accurate curves could be obtained for healthy controls and patients, with respective coefficients of determination (r2) of 0.9898 and 0.9778. Differences were observed between patients and normal subjects regarding curve shape, coefficients and the region of highest protein concentration. We conclude that the method provides accurate quantitative information on the composition of vWF multimers and may be useful for comparisons between groups and possibly treatments.


Assuntos
Hipertensão Pulmonar/sangue , Fator de von Willebrand/química , Adolescente , Adulto , Western Blotting , Estudos de Casos e Controles , Criança , Pré-Escolar , Densitometria , Humanos , Medições Luminescentes , Matemática , Pessoa de Meia-Idade , Peso Molecular , Sensibilidade e Especificidade
9.
Braz J Med Biol Res ; 46(4): 375-81, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23558858

RESUMO

Changes in plasma von Willebrand factor concentration (VWF:Ag) and ADAMTS-13 activity (the metalloprotease that cleaves VWF physiologically) have been reported in several cardiovascular disorders with prognostic implications. We therefore determined the level of these proteins in the plasma of children with cyanotic congenital heart disease (CCHD) undergoing surgical treatment. Forty-eight children were enrolled (age 0.83 to 7.58 years). Measurements were performed at baseline and 48 h after surgery. ELISA, collagen-binding assays and Western blotting were used to estimate antigenic and biological activities, and proteolysis of VWF multimers. Preoperatively, VWF:Ag and ADAMTS-13 activity were decreased (65 and 71% of normal levels considered as 113 (105-129) U/dL and 91 ± 24% respectively, P < 0.003) and correlated (r = 0.39, P = 0.0064). High molecular weight VWF multimers were not related, suggesting an interaction of VWF with cell membranes, followed by proteolytic cleavage. A low preoperative ADAMTS-13 activity, a longer activated partial thromboplastin time and the need for cardiopulmonary bypass correlated with postoperative bleeding (P < 0.05). Postoperatively, ADAMTS-13 activity increased but less extensively than VWF:Ag (respectively, 2.23 and 2.83 times baseline, P < 0.0001), resulting in an increased VWF:Ag/ADAMTS-13 activity ratio (1.20 to 1.54, respectively, pre- and postoperative median values, P = 0.0029). ADAMTS-13 consumption was further confirmed by decreased ADAMTS-13 antigenic concentration (0.91 ± 0.30 to 0.70 ± 0.25 µg/mL, P < 0.0001) and persistent proteolysis of VWF multimers. We conclude that, in pediatric CCHD, changes in circulating ADAMTS-13 suggest enzyme consumption, associated with abnormal structure and function of VWF.


Assuntos
Proteínas ADAM/sangue , Cardiopatias Congênitas/sangue , Fator de von Willebrand/análise , Proteína ADAMTS13 , Biomarcadores/sangue , Western Blotting , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Cardiopatias Congênitas/cirurgia , Humanos , Lactente , Valor Preditivo dos Testes
10.
Pregnancy Hypertens ; 2(3): 318-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26105468

RESUMO

INTRODUCTION: The decision of a woman to get pregnant at later age of her reproductive cycle has be a phenomenon around the world. Epidemiology data show frequent increase of clinical complications in direct proportion in advanced age motherhood, hypertensive disturbances being more prevalent. OBJECTIVES: Analyse the prevalence of hypertensive syndromes in pre-determined age groups at Hospital Guilherme Álvaro in Santos, São Paulo, Brazil showing the different segments in each one. METHODS: From data collected in the outpatient department of Hospital Guilherme Álvaro of High Risk Pre-natal between 04/06/2008 and 30/05/2011, a prevalence transversal study was carried out where data were obtained from 628 patients aged between 16 and 46years. Procedures of homogeny analysts were set out, always collecting data such as age and disorder for high risk gestation. According to age, patients were divided into groups: precocious (up to 19years old), middle age (between 20 and 34) and late pregnancies (over 35). RESULTS: In the precocious pregnancies, clinical illnesses/no hypertension (31%) were observed in first place, 25% (8) twin pregnancy in second place, 19% (6) showed hypertensive disturbances. Concerning pregnancies between 20 and 34years old, 36% (144 patients) showed hypertensive syndromes, 23% (92 patients) showed endocrine disturbances, 22% (90 patients) showed clinical illnesses/no hypertension, and 9% twin pregnancy. Regarding late pregnancies, the most frequent disturbance was isolated hypertensive syndromes: 44% (88 patients) in first place, only endocrine disturbances, 24% (47 patients) in second place followed by association between hypertensive syndromes and endocrinopathy with 13% (26 patients). CONCLUSION: About precocious pregnancies, greater prevalence showed clinical illnesses/no hypertension, whereas middle age and late pregnancies showed greater hypertensive syndrome prevalence, results, which are compatible with other studies, have been observed that due to advance of age, hypertensive syndromes are more frequent. For late pregnancies, the prevalence of clinical illnesses/no hypertension was a lower percentage regarding the other two groups: precocious pregnancies (31%=10 women), middle age pregnancies (22%=90 women), and late pregnancies (2%=7 women). Considering the fact that the occurrence of pregnancy is more and more late in life, it can be concluded that the professionals must be prepared to attend pregnancies on women with hypertensive disturbances and their eventual complications.

12.
Braz J Med Biol Res ; 44(12): 1269-75, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22068906

RESUMO

Biomarkers have been identified for pulmonary arterial hypertension, but are less well defined for specific etiologies such as congenital heart disease-associated pulmonary arterial hypertension (CHDPAH). We measured plasma levels of eight microvascular dysfunction markers in CHDPAH, and tested for associations with survival. A cohort of 46 inoperable CHDPAH patients (age 15.0 to 60.2 years, median 33.5 years, female:male 29:17) was prospectively followed for 0.7 to 4.0 years (median 3.6 years). Plasma levels of von Willebrand factor antigen (VWF:Ag), tissue plasminogen activator (t-PA) and its inhibitor (PAI-1), P-selectin, reactive C-protein, tumor necrosis factor alpha, and interleukin-6 and -10 were measured at baseline, and at 30, 90, and 180 days in all subjects. Levels of six of the eight proteins were significantly increased in patients versus controls (13 to 106% increase, P < 0.003). Interleukin-10 level was 2.06 times normal (P = 0.0003; Th2 cytokine response). Increased levels of four proteins (t-PA, PAI-1, P-selectin, and interleukin-6) correlated with disease severity indices (P < 0.05). Seven patients died during follow-up. An average VWF:Ag (mean of four determinations) above the level corresponding to the 95th percentile of controls (139 U/dL) was independently associated with a high risk of death (hazard ratio = 6.56, 95%CI = 1.46 to 29.4, P = 0.014). Thus, in CHDPAH, microvascular dysfunction appears to involve Th2 inflammatory response. Of the biomarkers studied, plasma vWF:Ag was independently associated with survival.


Assuntos
Cardiopatias Congênitas/sangue , Hipertensão Pulmonar/sangue , Fator de von Willebrand/imunologia , Adolescente , Adulto , Biomarcadores/sangue , Métodos Epidemiológicos , Hipertensão Pulmonar Primária Familiar , Feminino , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/mortalidade , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/mortalidade , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Fator de von Willebrand/análise
13.
Int J Parasitol ; 41(3-4): 333-42, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21118695

RESUMO

Interspecies variations in lipophosphoglycan (LPG) have been the focus of intense study over the years due its role in specificity during sand fly-Leishmania interaction. This cell surface glycoconjugate is highly polymorphic among species with variations in sugars that branch off the conserved Gal(ß1,4)Man(α1)-PO(4) backbone of repeat units. However, the degree of intraspecies polymorphism in LPG of Leishmania infantum (syn. Leishmania chagasi) is not known. In this study, intraspecific variation in the repeat units of LPG was evaluated in 16 strains of L. infantum from Brazil, France, Algeria and Tunisia. The structural polymorphism in the L. infantum LPG repeat units was relatively slight and consisted of three types: type I does not have side chains; type II has one ß-glucose residue that branches off the disaccharide-phosphate repeat units and type III has up to three glucose residues (oligo-glucosylated). The significance of these modifications was investigated during in vivo interaction of L. infantum with Lutzomyia longipalpis, and in vitro interaction of the parasites and respective LPGs with murine macrophages. There were no consequential differences in the parasite densities in sand fly midguts infected with Leishmania strains exhibiting type I, II and III LPGs. However, higher nitric oxide production was observed in macrophages exposed to glucosylated type II LPG.


Assuntos
Glicoesfingolipídeos/química , Interações Hospedeiro-Parasita , Leishmania infantum/fisiologia , Macrófagos Peritoneais/parasitologia , Psychodidae/parasitologia , Argélia , Animais , Brasil , Sistema Digestório/parasitologia , França , Glicoesfingolipídeos/classificação , Glicoesfingolipídeos/genética , Leishmania infantum/metabolismo , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Tunísia
15.
Rev. bras. plantas med ; Rev. bras. plantas med;16(4): 832-838, oct.-dic. 2014. graf
Artigo em Português | LILACS | ID: lil-729891

RESUMO

O uso popular, e mesmo o tradicional, não são suficientes para validar as plantas medicinais como medicamentos eficazes e seguros. Para melhor entendimento, é necessário avaliar a relação risco/benefício de seu uso, por meio de estudos toxicológicos. O objetivo desta pesquisa foi estimar a toxicidade aguda do extrato etanólico das cascas secas de Pithecellobium cochliocarpum (Gomez) Macbr através da obtenção da dose letal (DL50) em roedores, e da Concentração letal (CL50) frente à Artemia salina Leach. Foram realizados experimentos por via oral e intraperitoneal utilizando camundongos fêmeas albinos Swiss (Mus musculus) (n=6). Por via oral foram administradas 3 doses (1.000, 3.000 e 5.000 mg Kg-1) e por via entraperitoneal, 5 doses (155, 160, 176, 345,6 e 414,72 Kg-1). Os sinais comportamentais foram avaliados durante uma hora após a administração do extrato, ficando em observação até 48 horas. O número de óbitos foi quantificado para posterior cálculo da DL50. A administração por via intraperitoneal foi realizada em intervalo de 5 minutos para cada animal. Nos ensaios de toxicidade por via oral a solução foi introduzida por via intragástrica através de cânula metálica acoplada a seringa (gavagem) no mesmo intervalo de tempo utilizado pela via intraperitoneal. Os animais do grupo de administração oral apresentaram algumas reações, porém não letais até a dose de 5.000 mg Kg-1. A DL50 para a via intraperitoneal foi 257, 49 mg Kg-1 (muito tóxico, grau 4) (Schuartsman, 1980). A CL50 (543,5 µg Kg-1) demonstrou ser tóxica frente à A. salina. Conclui-se que sob condições agudas de exposição, o extrato do Pithecellobium cochliocarpum é um agente tóxico, devendo ser considerado como tal, dependendo da dose administrada ou absorvida, do etempo e frequência de exposição e das vias de administração.


The popular use, and even the traditional one, is not enough to validate medicinal plants as effective and safe medicines. For a better understanding, it is necessary to assess the risk / benefit ratio of their use through toxicological studies. The aim of this work was to evaluate the acute toxicity of Pithecellobium cochliocarpum (Gomez) Macbr dried bark ethanolic extract through its lethal dose (LD50), in mice, and lethal concentration (LC50) in relation to Artemia salina Leach. Experiments were performed by oral and intraperitoneal route using female Swiss albino mice (Mus musculus) (n = 6). The first three doses were given orally (1,000, 3,000 and 5,000 mg kg-1) and the last five doses were given intraperitoneally (155, 160, 176, 345.6 and 414.72 Kg-1). The behavioral signs were evaluated one hour after administration of the extract, being observed up to 48 hours. The number of deaths was quantified for subsequent calculation of LD50. The intraperitoneal administration was carried out at an interval of 5 minutes for each animal. For the oral toxicity test, the solution was introduced in the digestive system of the animals through a metal cannula coupled to a syringe (gavage) at the same time interval used for the intraperitoneal route. The animals from the oral group presented some reactions, but they were not lethal up to the dose of 5.000 mg kg-1. The LD50 for the intraperitoneal group was 257.49 mg kg-1 (very toxic, grade 4) (Schuartsman, 1980). The LC50 (543.5 mg kg-1) was toxic to A. salina. We can conclude that, under acute conditions of exposure, the Pithecellobium cochliocarpum extract is a poisonous agent and should be considered as such depending on the administered or absorbed dose, the time and frequency of exposure, and the administration routes.


Assuntos
Animais , Feminino , Camundongos , Toxicidade , Extratos Vegetais/análise , Fabaceae/classificação , Plantas Medicinais/classificação , Fitoterapia/instrumentação
16.
Braz J Med Biol Res ; 41(8): 657-63, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18797697

RESUMO

We investigated whether chronic rosuvastatin administration could improve the abnormalities of the circulating levels of vascular dysfunction markers in pulmonary arterial hypertension (PAH). Sixty patients, aged 13 to 60 years, with idiopathic (N = 14) or congenital heart disease-associated PAH (N = 46) were equally but randomly assigned to rosuvastatin treatment (10 mg a day, orally) or placebo for 6 months in a blind fashion. Plasma levels of P-selectin, tissue-plasminogen activator and its inhibitor as well as von Willebrand factor antigen were measured by enzyme-linked immunoassay before and after 1, 3, and 6 months of treatment. Baseline levels of biomarkers were elevated (68, 16, 45 and 46% increase relative to controls, for P-selectin, von Willebrand factor antigen, tissue-plasminogen activator and its inhibitor, respectively; P < 0.001). P-selectin values at baseline, 1, 3, and 6 months were 39.9 +/- 18.5, 37.6 +/- 14.6, 34.8 +/- 14.6, and 35.4 +/- 13.9 ng/mL, respectively, for the rosuvastatin group and 45.7 +/- 26.8, 48.0 +/- 26.9, 48.1 +/- 25.7, and 45.7 +/- 25.6 ng/mL for the placebo group. The P-selectin level was lower in the rosuvastatin group compared with placebo throughout treatment (P = 0.037, general linear model). A trend was observed towards a decrease in tissue-plasminogen activator in the statin group (16% reduction, P = 0.094), with no significant changes in the other markers. Since P-selectin is crucial in inflammation and thrombosis, its reduction by rosuvastatin is potentially relevant in the pathophysiological scenario of PAH.


Assuntos
Endotélio Vascular/fisiopatologia , Fluorbenzenos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipertensão Pulmonar/tratamento farmacológico , Pirimidinas/uso terapêutico , Sulfonamidas/uso terapêutico , Adolescente , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Endotélio Vascular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Feminino , Cardiopatias Congênitas/complicações , Humanos , Hipertensão Pulmonar/sangue , Hipertensão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Selectina-P/sangue , Rosuvastatina Cálcica , Índice de Gravidade de Doença , Ativador de Plasminogênio Tecidual/antagonistas & inibidores , Ativador de Plasminogênio Tecidual/sangue , Adulto Jovem , Fator de von Willebrand/análise , Fator de von Willebrand/imunologia
17.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;46(4): 375-381, 05/abr. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-671392

RESUMO

Changes in plasma von Willebrand factor concentration (VWF:Ag) and ADAMTS-13 activity (the metalloprotease that cleaves VWF physiologically) have been reported in several cardiovascular disorders with prognostic implications. We therefore determined the level of these proteins in the plasma of children with cyanotic congenital heart disease (CCHD) undergoing surgical treatment. Forty-eight children were enrolled (age 0.83 to 7.58 years). Measurements were performed at baseline and 48 h after surgery. ELISA, collagen-binding assays and Western blotting were used to estimate antigenic and biological activities, and proteolysis of VWF multimers. Preoperatively, VWF:Ag and ADAMTS-13 activity were decreased (65 and 71% of normal levels considered as 113 (105-129) U/dL and 91 ± 24% respectively, P < 0.003) and correlated (r = 0.39, P = 0.0064). High molecular weight VWF multimers were not related, suggesting an interaction of VWF with cell membranes, followed by proteolytic cleavage. A low preoperative ADAMTS-13 activity, a longer activated partial thromboplastin time and the need for cardiopulmonary bypass correlated with postoperative bleeding (P < 0.05). Postoperatively, ADAMTS-13 activity increased but less extensively than VWF:Ag (respectively, 2.23 and 2.83 times baseline, P < 0.0001), resulting in an increased VWF:Ag/ADAMTS-13 activity ratio (1.20 to 1.54, respectively, pre- and postoperative median values, P = 0.0029). ADAMTS-13 consumption was further confirmed by decreased ADAMTS-13 antigenic concentration (0.91 ± 0.30 to 0.70 ± 0.25 µg/mL, P < 0.0001) and persistent proteolysis of VWF multimers. We conclude that, in pediatric CCHD, changes in circulating ADAMTS-13 suggest enzyme consumption, associated with abnormal structure and function of VWF.


Assuntos
Criança , Pré-Escolar , Humanos , Lactente , Proteínas ADAM/sangue , Cardiopatias Congênitas/sangue , Fator de von Willebrand/análise , Western Blotting , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática , Cardiopatias Congênitas/cirurgia , Valor Preditivo dos Testes
18.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;44(12): 1269-1275, Dec. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-606536

RESUMO

Biomarkers have been identified for pulmonary arterial hypertension, but are less well defined for specific etiologies such as congenital heart disease-associated pulmonary arterial hypertension (CHDPAH). We measured plasma levels of eight microvascular dysfunction markers in CHDPAH, and tested for associations with survival. A cohort of 46 inoperable CHDPAH patients (age 15.0 to 60.2 years, median 33.5 years, female:male 29:17) was prospectively followed for 0.7 to 4.0 years (median 3.6 years). Plasma levels of von Willebrand factor antigen (VWF:Ag), tissue plasminogen activator (t-PA) and its inhibitor (PAI-1), P-selectin, reactive C-protein, tumor necrosis factor alpha, and interleukin-6 and -10 were measured at baseline, and at 30, 90, and 180 days in all subjects. Levels of six of the eight proteins were significantly increased in patients versus controls (13 to 106 percent increase, P < 0.003). Interleukin-10 level was 2.06 times normal (P = 0.0003; Th2 cytokine response). Increased levels of four proteins (t-PA, PAI-1, P-selectin, and interleukin-6) correlated with disease severity indices (P < 0.05). Seven patients died during follow-up. An average VWF:Ag (mean of four determinations) above the level corresponding to the 95th percentile of controls (139 U/dL) was independently associated with a high risk of death (hazard ratio = 6.56, 95 percentCI = 1.46 to 29.4, P = 0.014). Thus, in CHDPAH, microvascular dysfunction appears to involve Th2 inflammatory response. Of the biomarkers studied, plasma vWF:Ag was independently associated with survival.


Assuntos
Adolescente , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Cardiopatias Congênitas/sangue , Hipertensão Pulmonar/sangue , Fator de von Willebrand/imunologia , Biomarcadores/sangue , Métodos Epidemiológicos , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/mortalidade , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/mortalidade , Fator de von Willebrand/análise
19.
Mem Inst Oswaldo Cruz ; 95(5): 707-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10998220

RESUMO

The alpha-glycerophosphate dehydrogenase (alpha-GPDH) activity in flight muscles of Panstrongylus megistus and Triatoma sordida, vectors of Chagas disease in Brazil, was studied. Both species showed higher enzymatic activities in fliers than in non-fliers insects. T. sordida exhibited a higher proportion of flier insects than P. megistus. A possible role of alpha-GPDH on triatomines flight is discussed.


Assuntos
Voo Animal/fisiologia , Glicerolfosfato Desidrogenase/metabolismo , Insetos Vetores/enzimologia , Músculos/enzimologia , Proteínas de Protozoários/metabolismo , Triatominae/enzimologia , Animais , Glicerolfosfato Desidrogenase/fisiologia , Panstrongylus/enzimologia , Proteínas de Protozoários/fisiologia , Triatoma/enzimologia
20.
Haemophilia ; 7(3): 299-305, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11380635

RESUMO

In families afflicted with haemophilia A, genetic counselling is often requested. Inversion mutations and polymorphic sites of the FVIII gene have been examined in a Brazilian population, with the aim of developing a strategy that would be accurate and informative for carrier analysis and prenatal diagnosis in Brazil. Patients with haemophilia A and families were studied. Inversion mutations in the FVIII gene were detected in 39.4% of severely affected patients, 85% of them being of distal type. No inversions were observed in patients with mild or moderate forms of the disease. Two bi-allelic polymorphisms were studied. Intron 18 SSCP and intron 19 RFLP analyses indicated the presence of a restriction site in 39.5% and 42.9% of haemophilics, respectively. Two multiallelic microsatellite polymorphisms in introns 13 and 22 were also studied; eight different alleles were detected in each system with a heterozygosity rate of 83.08% and 78.77%, respectively. When all four intragenic loci were examined in linkage analysis, the cumulative reliability was 100%. In conclusion, inversion mutation analysis should be the first-line test for Brazilian patients with severe haemophilia A. In cases of severe haemophilia A where no inversion could be detected or in mild or moderate haemophilia A, the use of all four polymorphisms is very informative for linkage analysis and should be used for carrier detection and genetic counselling in the Brazilian population.


Assuntos
Fator VIII/genética , Hemofilia A/genética , Brasil/epidemiologia , Inversão Cromossômica , Análise Mutacional de DNA , Saúde da Família , Feminino , Frequência do Gene , Triagem de Portadores Genéticos/métodos , Testes Genéticos , Humanos , Íntrons , Masculino , Polimorfismo Genético , Diagnóstico Pré-Natal/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA