Débora Campos

Crude extracts from 17 plant species collected from an Atlantic Forest region in the State of São Paulo (Brazil) have been screened for antifungal, DNA-damaging and acetylcholinesterase inhibiting activities. Of the 34 extracts obtained from leaves and stems of plants assayed for antifungal activity with Cladosporium sphaerospermum and C. cladosporioides 26.5% were active. However, only the extract of leaves of Cabralea canjerana showed a strong inhibition of both fungi. The DNA-damaging assay with mutant strains of Saccharomyces cerevisiae resulted in 11.7 % of the extracts being active whereas 100% of them showed selectivity for the DNA-repair mechanism of topoisomerase II. Of the 17 species analysed, 12 showed anticholinesterasic activity in TLC assay. However, only extracts from Tetrastylidium grandifolium (stems) and Sloanea guianensis (leaves and stems) inhibited acetylcholinesterase activity more than 50% in quantitative assay.

Foram estudados tumores de mama em cadelas, comparando o seu padrão citológico, obtido através da Citologia Aspirativa por Agulha Fina (CAAF), com os resultados da histopatologia. Num período de um ano, as cadelas trazidas ao Hospital Veterinário ¾ UNESP ¾ Câmpus de Jaboticabal foram submetidas a exérese cirúrgica dos tumores mamários. As amostras foram avaliadas de acordo com parâmetros estruturais utilizados nos tumores mamários humanos, como grau de atipia, critérios nucleares, padrão de cromatina e nucléolos, alta celularidade e pouca coesão intercelular. Utilizaram-se estes critérios para diferenciar tumores mamários benignos de malignos com 63% de diagnósticos concordantes, sensibilidade de 73% e especificidade de 83%. Nossos dados mostraram ter uma correlação positiva com o prognóstico, demonstrando que é possível reconhecer variáveis estruturais de malignidade na citopatologia para obter um diagnóstico precoce e um prognóstico seguro.

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6%) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

The micronucleus (Mn) and other kinds of erythrocyte nuclear abnormality (ENA) assays were used to assess the genotoxic potential of the seawater in front of the Brazilian Antarctic Research Station “Comandante Ferraz” (King George Island). In two consecutive summers, the fish Trematomus newnesi was exposed to the seawater in front of the fuel storage tanks and the sewage discharge outlet of the Station in laboratory bioassays and in situ caging assays. After the exposure, frequencies of ENA and Mn were scored on blood smears. Significantly higher Mn and ENA frequencies in relation to those of the controls were observed in fish exposed to both types of water, in both types of experiment. Seawater in front of the fuel tanks and sewage discharge outlet at the Station was found to induce the formation of micronuclei and other ENAs, indicators of genotoxicity. The need for further investigation and the suitability of the methods for screening mutagenic pollution in polar waters are discussed.

The photo-induced toxicity of anthracene was investigated as the mortality in Antarctic shallow water amphipod, Gondogeneia antarctica, at different concentrations of anthracene and different periods of exposure to natural sunlight and artificial UVA and UVB radiations. When exposed to natural sunlight, animals contaminated in the dark and placed in clean water or in anthracene solutions showed different degrees of mortality, dose–time dependent. Effects were even more evident when these animals were exposed to artificial UVA or UVB radiations. Depuration seemed to be a slow process. The effects of UV radiation and anthracene alone and the effects of the interactions of these two stressors implied that solar radiation is an important parameter that deserves consideration in the environmental assessment of polycyclic aromatic hydrocarbons in Antarctic coastal waters. G. antarctica proved to be a good bioindicator for the phototoxicity of anthracene in Antarctic shallow waters.