Xylarenones C-E from an Endophytic Fungus Isolated from Alibertia macrophylla

Xylarenones C-E (2-4), three new eremophilane sesquiterpenes, have been isolated from solid substrate cultures of a Camarops-like endophytic fungus isolated from Alibertia macrophylla. The structures were elucidated by analysis of spectroscopic data. Compounds were evaluated in subtilisin and pepsin protease assays, and compound 2 showed potent inhibitory activity against both proteases.

Toxoplasma gondii: isolation of tachyzoites rhoptries and incorporation into Iscom

Rhoptries have been isolated from Toxoplasma gondii tachyzoites by subcellular fractionation in isopynic density sucrose gradient. Five bands were observed, and transmission electron microscopy of these indicated that rhoptries were in band 3. This band had a density of 1.17g/cm(3). Fraction 1 had membrane structures of the parasite. Fraction 2 contained membranes and mitochondria (Fig. 1 B). Fraction 4 had mostly conoid structure (Fig. 2B) and fraction 5 showed ghosts. The electrophoretic and Western blotting analysis of the fractions indicated the presence of a number of proteins. Iscoms were constructed from band 3, which contained the rhoptry structures. Iscom showed a only protein incorporated of 55 kDa. Isolation of the parasite organelles has got in this work is necessary to identification, characterization, and function elucidation of the organelle proteins. (C) 2004 Elsevier B.V. All rights reserved.

Dose-dependent effect of Resveratrol on bladder cancer cells: Chemoprevention and oxidative stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Taurine bromamine: A potent oxidant of tryptophan residues in albumin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Invasion of epithelial mammalian cells by Paracoccidioides brasiliensis leads to cytoskeletal rearrangement and apoptosis of the host cell

Paracoccidioides brasiliensis (Pb) yeast cells can enter mammalian cells and probably manipulate the host cell environment to favor their own growth and survival. We studied the uptake of strain Pb 18 into A549 lung and Vero epithelial cells, with an emphasis on the repercussions in the cytoskeleton and the apoptosis of host cells. Cytoskeleton components of the host cells, such as actin and tubulin, were involved in the P. brasiliensis invasion process. Cytochalasin D and colchicine treatment substantially reduced invasion, indicating the functional participation of microfilaments (MFs) and microtubules (MTs) in this mechanism. Cytokeratin could also play a role in the P. brasiliensis interaction with the host. Gp43 was recognized by anti-actin and anti-cytokeratin antibodies, but not by anti-tubulin. The apoptosis induced by this fungus in infected epithelial cells was demonstrated by various techniques: TUNEL, DNA fragmentation and Bak and Bcl-2 immunocytochemical expression. DNA fragmentation was observed in infected cells but not in uninfected ones, by both TUNEL and gel electrophoresis methods. Moreover, Bcl-2 and Bak did not show any differences until 24 h after infection of cells, suggesting a competitive mechanism that allows persistence of infection. Overexpression of Bak was observed after 48 h, indicating the loss of competition between death and survival signals. In conclusion, the mechanisms of invasion of host cells, persistence within them, and the subsequent induction of apoptosis of such cells may explain the efficient dissemination of P. brasiliensis. (C) 2004 Published by Elsevier SAS.

Expressão imunoistoquímica de Glut-1 e marcadores de proliferação e apoptose em anomalias vasculares orais

Vascular anomalies constitute a distinct group of lesions, but they may present similar clinical and histopatological characteristics, which can lead to diagnostic mistakes. This study aimed by histopathology and immunohistochemical expression of human glucose transporter protein (GLUT-1), correctly identify and classify oral vascular anomalies, besides analyzing the immunoexpression of markers proliferation and apoptosis (Ki-67 and Bcl-2). All cases diagnosed as "oral hemangiomas" belonging to the archives of the Service of Pathological Anatomy from the subject of Oral Pathology of the Department of Dentistry (DOD), of the Federal University of Rio Grande do Norte (UFRN) were reviewed, totalizing 77 cases. Immunohistochemical analysis for GLUT-1 showed that only 26 (33.8%) of the specimens were true infantile hemangiomas (IHs). The 51 (66.2%%) GLUT-1 negative specimens were then reclassified as pyogenic granulomas (PGs) and vascular malformations (VMs) from their histopathologic characteristics,totalizing 26 (33.8%) cases of IHs, 20 (26.0%) of PGs and 31 (40.2) cases of oral VMs. The cases analyzed by the marker Ki-67 showed different median IH (13,85), PG (33,70) and VM (4.55) with statistically significant differences between them (p <0.001). In relation to the protein Bcl-2, the groups also showed different median of the established scores IH (1.00), PG (1.50), VMs (0.0) demonstrating statistically significant differences between them (p<0,001). No statistically significant correlation between the indexes of positivity for Ki-67 and the scores of immunoexpression of Bcl-2 were observed in any group. Thus, we can conclude that it is necessary a careful and parameterized review of cases of vascular anomalies making use of auxiliary tools such as GLUT-1, since the histopathological findings alone, sometimes, are not sufficient to differentiate some anomalies. Furthermore, analysis of the expressions of markers involved in the levels of proliferation of lesions is important for a better understanding of its biological behavior aspect

Toxicidade da mitomicina C ao endotélio da córnea de coelhos

Purpose: To evaluate corneal endothelium alterations after applying mitomycin C to the sclera using transmission and scanning electron microscopy, correlating alterations with time, concentration, and evaluation methods. Methods: The corneal endothelium of both eyes of 32 albino rabbits was evaluated and distributed into four groups of 8. Mitomycin C was applied under a scleral flap in the right eye for 5 minutes. Mitomycin C concentrations were 0.5 mg/ml for G1 and G2 and 0.2 mg/ml for G3 and G4. Examinations were performed 15 days after application to G1 and G3, and 30 days after application to G2 and G4. Four cornea in each group were prepared for transmission electron microscopy and four for scanning electron microscopy. Left eyes of all animals were used as controls. Results: Transmission electron microscopy showed corneal endothelium alterations in all groups: rarefied cytoplasm, dilation and fragmentation of rough endoplasmic reticulum cisternae, Golgi apparatus with cisternal dilation, reduced vacuoles, and irregularities of internal membrane more noticeable in G1 and G2. Scanning electron microscopy revealed alterations in all groups except G1: changes in the shape and size of cells and longer filopodial projections. Conclusions: 1-Corneal endothelium alterations were seen at both 0.5 and 0.2 mg/ml concentrations and at 15 and 30 days after mytomicin C application; 2 - Alterations were more intense with higher mytomicin C concentration by transmission electron but not by scanning electron microscopy; 3 - The alterations correlated with time by scanning electron microscopy but not by transmission electron microscopy.

Estudo comparativo entre os métodos LSAB®+ e Herceptest® para a detecção de HER-2/neu em carcinoma de mama

INTRODUÇÃO: A hiperexpressão de human epidermal growth factor receptor (HER-2/neu) e a amplificação do seu gene são indicadores de formas mais agressivas do câncer de mama. A Food and Drug Administration (FDA) aprovou o teste denominado HercepTest® com a finalidade de selecionar pacientes com indicação para o uso de um anticorpo humanizado anti-HER-2/neu (trastuzumab), com efeito terapêutico comprovado. OBJETIVOS: O presente trabalho tem como objetivo comparar os resultados obtidos pelos métodos imuno-histoquímicos LSAB®+ com a utilização de anticorpo A0485 e HercepTest®. Material e métodos: Foram utilizados 50 casos de carcinoma de mama nos quais a pesquisa da hiperexpressão de HER-2 pelo método LSAB®+ já havia sido realizada. Foi repetida a pesquisa da hiperexpessão de HER-2/neu nos mesmos casos, utilizando-se o método do HercepTest®. RESULTADOS: 34 casos foram considerados negativos pelos dois métodos, com escore 0 pelo método HercepTest®. Destes, 12 obtiveram escore 1+ e 22 obtiveram escore 0 pelo método LSAB®+. em oito casos, o escore foi 2+ pelos dois métodos. Escore 3+ foi encontrado também em oito casos pelos dois métodos. DISCUSSÃO: O método mais prático utilizado em laboratório de rotina diagnóstica para investigar a hiperexpressão de HER-2/neu é o estudo imuno-histoquímico. em função de muitas variáveis, como tempo de fixação, tipo de fixador, duração da fixação, método de recuperação antigênica e tipo de anticorpo utilizado, pode haver divergência de resultados. CONCLUSÃO: O presente estudo concluiu que o método HercepTest®demonstrou resultados equivalentes aos resultados obtidos pelo método LSAB®+ em carcinoma de mama.

Evaluation of Carcinogenic Potential of Diuron in a Rat Mammary Two-Stage Carcinogenesis Model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of vitamin C in delayed tooth replantation

O objetivo deste trabalho foi avaliar microscopicamente, em reimplantes tardios de dentes de rato, os efeitos do tratamento da superfície radicular com diferentes soluções. Foram utilizados 30 ratos Rattus norvegicus albinos da linhagem Wistar que tiveram seus incisivos centrais extraídos e deixados sobre a bancada por 6 h. As polpas foram extirpadas e os canais irrigados com solução de hipoclorito de sódio a 1%. Após o preparo endodôntico, a superfície radicular de cada dente foi tratada com solução de hipoclorito de sódio a 1% por 10 min (trocada a cada 5 min) seguida de soro fisiológico por 10 min, e os dentes foram divididos em três grupos com 10 espécimes em cada um. Nos Grupos I, II e III, respectivamente, a superfície radicular foi tratada com fluoreto de sódio fosfato acidulado a 2%, vitamina C e vitamina C efervescente (2 g, Redoxon®). Após obturação com pasta de hidróxido de cálcio os dentes foram reimplantados e os animais foram sacrificados aos 10 e 60 dias. O Grupo I apresentou maiores áreas de reabsorção por substituição e anquilose. Comparando as formas de vitamina C utilizadas, a efervescente (Grupo III) foi a que apresentou resultados mais favoráveis com mais áreas de anquilose e reabsorção por substituição que áreas de reabsorção inflamatória.

Structural Basis of Importin-alpha-Mediated Nuclear Transport for Ku70 and Ku80

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tissue changes in senescent gerbil prostate after hormone deprivation leads to acquisition of androgen insensitivity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crystallization and preliminary X-ray crystallographic analysis of the heterodimeric crotoxin complex and the isolated subunits crotapotin and phospholipase A(2)

Crotoxin, a potent neurotoxin from the venom of the South American rattlesnake Crotalus durissus terrificus, exists as a heterodimer formed between a phospholipase A(2) and a catalytically inactive acidic phospholipase A(2) analogue (crotapotin). Large single crystals of the crotoxin complex and of the isolated subunits have been obtained. The crotoxin complex crystal belongs to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 38.2, b = 68.7, c = 84.2 angstrom, and diffracted to 1.75 angstrom resolution. The crystal of the phospholipase A(2) domain belongs to the hexagonal space group P6(1)22 (or its enantiomorph P6(5)22), with unit-cell parameters a = b = 38.7, c = 286.7 angstrom, and diffracted to 2.6 angstrom resolution. The crotapotin crystal diffracted to 2.3 angstrom resolution; however, the highly diffuse diffraction pattern did not permit unambiguous assignment of the unit-cell parameters.

Sol-gel synthesis and characterization of Fe(2)O(3) center dot CeO(2) doped with Pr ceramic pigments

Undoped x center dot alpha-Fe(2)O(3) y center dot CeO(2) and doped with praseodymium ceramic pigments were obtained by the sol-gel method after heat treatment at 800 degrees C for 2 h. These pigments were characterized by XRD, nitrogen adsorption, scanning electron microscopy, ultraviolet-visible absorption spectroscopy and colorimetrical measurements. Red and brown colors with several tonalities were observed after changes with Ce and Pr concentration.