RESUMO
BACKGROUND Chagas disease, resulting from Trypanosoma cruzi infections, continues to be a health concern mainly in Latin American countries where the parasite is endemic. The laboratory diagnosis of a chronic infection is determined through serological assays for antibodies against T. cruzi and several tests are available that differ in key components, formats and methodologies. To date, no single test meets the criteria of a gold standard. The situation is further complicated by the difficulties associated with performance comparisons between different immunoassays or methodologies executed at different times and geographical areas. OBJECTIVE To improve the diagnosis of Chagas disease, the WHO coordinated the development of two International Biological Reference Standards for antibodies against anti-T. cruzi: NIBSC 09/186 and NIBSC 09/188 that respectively represent geographical regions with the highest prevalence of TcII and TcI lineages of the parasite. METHODS The principle goal of this study was to verify the behavior of these standards when assayed by several commercially available serological tests that employ different methods to capture and detect human anti-T. cruzi antibodies. FINDINGS AND MAIN CONCLUSIONS The results reinforce the recommendation that these standards be considered for performance evaluations of commercialised immunoassays and should be an integral step in the development of new test components or assay paradigms.
Assuntos
Doença de Chagas/diagnóstico , Testes Sorológicos/normas , Trypanosoma cruzi/isolamento & purificação , Anticorpos Antiprotozoários/sangue , Doença de Chagas/parasitologia , Humanos , Imunoensaio/métodos , Padrões de Referência , Testes Sorológicos/métodos , Trypanosoma cruzi/imunologia , Organização Mundial da SaúdeRESUMO
Physical exercise is known to activate the sympathetic nervous system, which influences the production of saliva from salivary glands. Our examination of saliva collected from highly trained athletes before and after a number of physical competititions showed an increase in the secretion of S-type cystatins and cystatin C as a subacute response to aerobic and anaerobic exercise. The elevation in salivary cystatins was transient and the recovery time course differed from that of amylase and other salivary proteins. An in vitro assay was developed based on a cell line from a human submandibular gland (HSG) that differentiated into acinus-like structures. Treatments with the ß-adrenergic agonist isoproterenol caused a shift in the intracellular distribution of S-type cystatins and cystatin C, promoting their accumulation at the outer regions of the acinus prior to release and suggesting the activation of a directional transport involving co-migration of both molecules. In another treatment using non-differentiated HSG cells, it was evident that both expression and secretion of cystatin C increased upon addition of the ß-adrenergic agonist, and these effects were essentially eliminated by the antagonist propranolol. The HSG cell line appears to have potential as a model for exploring the mechanism of cystatin secretion, particularly the S-type cystatins that originate primarily in the submandibular glands.
Assuntos
Exercício Físico , Cistatinas Salivares/metabolismo , Glândula Submandibular/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Células Cultivadas , Humanos , Masculino , Glândula Submandibular/citologia , Glândula Submandibular/efeitos dos fármacosRESUMO
The technique of high-speed countercurrent chromatography was applied to the isolation of compounds in essential oil derived from the leaves of Piper mollicomum species. Plant leaves (200.0 g) were submitted to hydrodistillation in a modified Clevenger apparatus. The resulting crude leaf essential oil was analyzed by gas chromatography with flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) to determine the profile of the components. The purified fractions were composed of monoterpenes and sesquiterpenes such as camphor (85.0 mg at 98.5% purity), (E)-nerolidol (100.0 mg at 92.8% purity), and camphene (150.0 mg at 82.0% purity). A minor component of the essential oil, bornyl acetate (16.2 mg at 91.2% purity) was also isolated in the one-step separation protocol in 2 h. The countercurrent chromatography technique proved to be a fast and efficient method for the separation of volatile metabolites that conserved the solvent while delivering various fractions of high purity.
Assuntos
Cromatografia , Metabolômica , Óleos Voláteis/química , Piper/química , Folhas de Planta/química , Compostos Orgânicos Voláteis/química , Cromatografia/métodos , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Metabolômica/métodos , Estrutura Molecular , SolventesRESUMO
Together, the three human rhinovirus (RV) species are the most frequent cause of the common cold. Because of their high similarity with other viral species of the genus Enterovirus, within the large family Picornaviridae, studies on RV infectious activities often offer a less pathogenic model for more aggressive enteroviruses, e.g. poliovirus or EV71. Picornaviruses enter via receptor mediated endocytosis and replicate in the cytosol. Most of them depend on functional F-actin, Rab proteins, and probably motor proteins. To assess the latter, we evaluated the role of myosin light chain kinase (MLCK) and two myosin V isoforms (Va and Vb) in RV-B14 infection. We report that ML-9, a very specific MLCK inhibitor, dramatically reduced RV-B14 entry. We also demonstrate that RV-B14 infection in cells expressing dominant-negative forms of myosin Va and Vb was impaired after virus entry. Using immunofluorescent localization and immunoprecipitation, we show that myosin Va co-localized with RV-B14 exclusively after viral entry (15 min post infection) and that myosin Vb was present in the clusters of newly synthesized RNA in infected cells. These clusters, observed at 180 min post infection, are reminiscent of replication sites. Taken together, these results identify myosin light chain kinase, myosin Va and myosin Vb as new players in RV-B14 infection that participate directly or indirectly in different stages of the viral cycle.
Assuntos
Infecções por Enterovirus/prevenção & controle , Ácido Metilmalônico/análogos & derivados , Cadeias Pesadas de Miosina/antagonistas & inibidores , Miosina Tipo V/antagonistas & inibidores , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Infecções por Enterovirus/metabolismo , Infecções por Enterovirus/virologia , Células HeLa , Humanos , Ácido Metilmalônico/farmacologia , Fosforilação , Rhinovirus/efeitos dos fármacos , Rhinovirus/fisiologiaRESUMO
Echinodorus grandiflorus (Cham. & Schltdl.) Micheli is a native Brazilian species used in traditional practices for the treatment of several conditions such as inflammatory diseases, arthritis and hypertension. Through a systematic review of the accumulated knowledge about the species E. grandiflorus, the botanical, phytochemistry, ethnobotanical and pharmacological properties of this medicinal plant demonstrates its potential to naturally provide anti-inflammatory and anti-oxidant with a special emphasis on anti-hypertensive and cardioprotective effects. The body of literature reports that the chemical composition of crude E. grandiflorus extracts are notably composed of diterpenoids and flavonoids metabolites. Pharmacological studies have shown that oral treatments using the hydroalcoholic extracts of leaves from this plant has a significant anti-inflammatory, anti-hypertensive, diuretic and cardioprotective effects in rats with no toxicity. The holistic activities of complex extracts are corroborated by the individuals mechanisms of action, as well as, synergistic benefits attributed to the isolated chemical major constituents in this species. In light of the serious health concerns ascribed, it is important to investigate medicinal plant species with histories of traditional use for circulatory problems to meet the growing demands by scientifically validating their use and safety.
Assuntos
Alismataceae/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Anti-Hipertensivos/química , Anti-Hipertensivos/isolamento & purificação , Anti-Hipertensivos/farmacologia , Brasil , Humanos , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/isolamento & purificaçãoRESUMO
Aging represents a major risk factor for numerous illnesses that are of increasing importance to society, including two of the most prevalent: diabetes and Alzheimer's disease. Studies have shown that diabetes is a risk factor for spontaneous Alzheimer's disease. While these studies suggest that diabetes can contribute to Alzheimer's disease, the implications of AD on diabetes are practically unexplored. The major mediator of the pathophysiological effects, the Aß42 peptide, has been shown to enter neurons and lead to an alteration of the intracellular distribution of the molecular motor myosin Vb. Myosin Vb functions in memory and learning by participating in the strengthening of the long-term potentiation (LTP) of synaptic transmissions. It has also been implicated in the translocation of the glucose transporter, GLUT4, to the plasma membrane in response to insulin, a process that is defective in diabetes. Here, the effect on GLUT4 upon entry of the Aß42 peptide into cultured chick retinal neurons was explored. The results suggest an alteration in distribution and a reduced level at the cell surface, as well as an increased colocalization with myosin Vb, which can partially explain the changes in glucose metabolism associated with AD. It is also shown that the presence of the Aß40 peptide inhibits the internalization of the Aß42 peptide in cultured cells. Together, the results provide additional targets for the development of therapeutics against the progression and effects of Alzheimer's disease.