FF - Separatas (Biblioteca)
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- New antivirals against herpes virus and HIVPublication . Valdeira, Maria Luísa; Gonçalves, JoãoIn recent years, the demand for new antiviral compounds has increased markdly. There are many contributing factors to this increased demand, including the ever-increasing prevalence of chronic viral injections such as HIV and heRpes viruses and it is important to inactivate these viruses, because the viral strains are resislant to drugs employed in the treatment of infections. In our Iaboratory, we have studied many types of new compounds as antivirals agents from plants used in African traditional medicine, plants of lhe Portuguese flora and synthesis of new severa types of compounds. In this moment, the antiviral research has been done with new synthesized porphyrin derivatives that are photosensilizers useful to photodynamic therapy. In addilion, catechois from abietic acid were prepared and evaluated for antiviral activity. Their properties were compared with those of carnosic acid, a natural-occurring catechol possessing an abietane skeleton and known as a potent antioxidant with anticancer and antiviral properties.
- Evidence for an acid phosphatase in African swine fever virusPublication . Valdeira, Maria Luisa; Duque-Magalhães, M. C.; Geraldes, A.An acid phosphatase activity has been detected in purified preparations of African swine fever virus. Purified viral cores obtained after Nonidet-P40 and 2-mercaptoethanol treatment of the virus retained the activity as assayed with nitrophenyl phosphate as substrate at pH 5. Enzyme cytochemistry by electron microscopy showed that the acid phosphatase activity is localized mainly inside the core of the virion. The molecular weight and the isoelectric point of the virus acid phosphatase activity confirmed that it was distinct from the host cellular enzyme.
- Effect of chloroquine on african swine fever virus infectionPublication . Geraldes, A.; Valdeira, M.L.When present during the whole infective cycle, the lysosomotropic drug, chloroquine, inhibited cytopathic changes and production of African swine fever virus (ASFV) in Vero cells. This inhibition decreased when the drug was added from 1 h to 4 h after infection. Chloroquine had no direct effect on the virus nor on viral adsorption and internalization. Electron microscopy showed that, in the presence of the drug, the virions were retained in large vacuoles having a lysosomal appearance. This inhibition was fully reversible, even when the drug was removed as late as 72 h after infection. The results support the hypothesis that ASFV enters the cells by adsorptive endocytosis and not by fusion with the plasma membrane.
- Distribuição dos Serogrupos de Pseudomonas Aeruginosa em Portugal (Interesse Epidemiológico)Publication . Ferreira, Maria Odette SantosSerotyping Pseudomonas aeruginosa was effectuated in 833 strains isolated from pacients of various hospital Centers and of normal population. To the determination of the antigenic O groups (Habs classifications), we used a technic of agglutination in slides OMS, putting in contact the alive germen with the 15 serums anti-O (Pasteur Institut, Paris). The most frequent serogroups in decreasing order of importance, spread among the whole population are: 0:11, 0:3, 0:6, 0:1, 0:4, 0:5, 0:7, 0:10, 0:13, 0:2, 0:12, 0:9, 0:8, 0:14, and 0:15. The serogroup 0:11 is clearly dominant among hospital population (31,54 %). In respect to the normal population, the sequence is the following : 0:6, 0:1, 0:3, 0:11, 0:5, 0:2, 0:9, 0:7, 0:13, 0;10, O;4, 0;8, 0;12, 0;14, 0;15, and the serogroups 0:6 and 0:1 are the most frequent (31,05 %). This simple and quick method of determination of the serogroups of Pseudomonas aeruginosa can be very helpful in the epidemiological study on the Pseudomonas pyocyanea. The knowledge of the most common serogroups among portuguese population, wether hospitable or not hospitable, brought an important contribute to our study on: 1 — The ecology of the pyocyanic bacillus in the hospital circle. 2 — lhe mislead of exogenous or endogen infections of Ps. aeruginosa in the Intensive Care Centers, with tracheatomy (Reanimation Center). 3 — The serodiagnostic of the hospital strains made in order to establish the bases of an eventual anti-pyocyanic vaccination of the pacients with a great danger of infection. 4 — The confrontation of the results of the serotyping with the others two epidemiological «markers»: the lysotyping and the pyocynotyping. This work led us to a greater exactness in the epidemiological inquests about Pseudomonas aeruginosa made in Portugal, and allow us to compare our results with other countries’ ones.
- Soluções padrão de tampão citratoPublication . Lito, M. J. Guiomar H. M.; Camões, M. Filomena G. F. C.
- Die Glykoside der Wurzeln von Asclepias glaucophylla SchlechterPublication . Nascimento Jr., J. M.; Tamm, Ch.; Jager, Herb; Reichstein, T.The roots of Asclepias glaucophylla SCHLECHTER are very rich in steroids;two distinct groups are present: cardenolides and ester glycosides of pregnane derivatives.
- Os cardenólidos e outros constituintes das folhas de Asclepias glaucophylla (Schlechter)Publication . Nascimento, J. M.Isolou-se das falhas de Asclepias glaucophylla uma mistura de cardenólidos que se conseguiu resolver parcialmente nos seus componentes, com emprego de cromatografia de adsorção e repartição e na qual se identificaram: a uzarigenina, muito provavelmente a coroglaucigenina e um monoglicósido cuja açúcar é a glucose e de que as constantes físicas não correspondem a nenhuma dos substâncias já descritas. Além de outros cardenólidos, isolaram-se ainda duas substâncias, uma com carácter fracamente polar e um composto poli-hidroxilado de polaridade elevada.
- Micronuclei and sister chromatid exchanges induced by capsaicin in human lymphocytesPublication . Marques, S.; Oliveira, N. G.; Chaveca, T.; Rueff, J.Capsaicin is the main pungent and irritating component of hot peppers (species Capsicum annuum and C. frutescens). Genotoxicity and carcinogenicity studies evaluating capsaicin effects are sparse and contradictory. In this study, we investigated the genotoxicity of capsaicin (10–200 μM) in human peripheral blood lymphocytes using the cytokinesis-block micronucleus (CBMN) assay and the sister chromatid exchange (SCE) assay in the presence or absence of external metabolic activation. Capsaicin induced the formation of micronuclei (MN) in a dose-dependent manner in the cytokinesis-blocked lymphocytes. This increase was more evident in the absence of metabolic activation, with a maximum of 3.4-fold increase above the background. Some inter-individual variability was observed. The results for the SCE assay also show that capsaicin is genotoxic and in this case with a more homogenous response among donors. This end-point, however, has proven to be less sensitive than the CBMN assay for capsaicin.
- Animais de laboratório: será possível dispensá-los?Publication . Mota-Filipe, Helder
- Effects of tempol, a membrane-permeable radical scavenger, in a rodent model of carrageenan-induced pleurisyPublication . Cuzzocrea, Salvatore; McDonald, Michelle C.; Filipe, Helder Mota; Constantino, Giuseppina; Mazzon, Emanuela; Santagati, Sabrina; Caputi, Achille P.; Thiemermann, CristophCarrageenan causes enhanced formation of reactive oxygen species, which contribute to the pathophysiology of inflammation. We have investigated the effects of tempol, a membrane-permeable radical scavenger, in rats subjected to carrageenan-induced pleurisy. Treatment of rats with tempol (10, 30, or 100 mg/kg 15 min prior to carrageenan) attenuated the pleural exudation and the migration of polymorphonuclear cells caused by carrageenan dose dependently. Tempol also attenuated the lung injury (histology) as well as the increase in the tissue levels of myeloperoxidase and malondialdehyde caused by carrageenan in the lung. However, tempol did not inhibit the activity of inducible nitric oxide synthase in the lungs. Immunohistochemical analysis for nitrotyrosine revealed positive staining in lungs from carrageenan-treated rats. Lung tissue sections from carrageenan-treated rats also showed positive staining for poly-(ADP-ribose) synthetase (PARS). The degree of staining for nitrotyrosine and PARS was markedly reduced in tissue sections obtained from carrageenan-treated rats, which had received tempol (100 mg/kg). Furthermore, treatment of rats with tempol significantly reduced (i) the formation of peroxynitrite, (ii) the DNA damage, (iii) the impairment in mitochondrial respiration, and (iv) the fall in the cellular level of NAD+ observed in macrophages harvested from the pleural cavity of rats treated with carrageenan. Tempol also attenuated the cell injury caused by hydrogen peroxide (1 mM) in cultured human endothelial cells. This study provides the first evidence that tempol, a small molecule which permeates biological membranes and scavenges ROS, attenuates the degree of inflammation and tissue damage associated with carageenan-induced pleurisy in the rat. The mechanisms of the anti-inflammatory effect of tempol are discussed.