Estudo histoquímico comparativo da matriz extracelular de tumores primários e metastáticos em ratos nude xenotransplantados com células KB / Histochemical comparative study of primary and metastatic tumors in nude rates xenotransplanted with KB cells

Estudou-se comparativamente, através de métodos histoquímicos, a expressäo dos componentes da matriz extracelular de tumores primitivos e metastáticos em ratos nude, xenotransplantados com células KB. Em ambas as neoplasias observou-se uma variabilidade tanto qualitativa como quantitativa dos componentes matriciais, coexistência de diferentes tipos de fibras, pouca representatividade de fibras elásticas de glicosaminoglicanas ácidas e sulfatadas e de polissacarídeos neutros, além da ausência de membrana basal

Occurrence of tetrodotoxin and paralytic shellfish toxins in Phallusia nigra (Tunicata, Ascidiacea) from the brazilian coast

We have already shown the presence of guanidine neurotoxins in calcareous red algae and mussels collected in the Säo Sebastiäo channel State of Säo Paulo,Brazil). It is known that these neurotoxins comprise more than 25 analogues such as tetrodotoxin (TTX) and derivatives plus the paralytic shellfish toxins (PST) found in a variety of marine, freshwater and amphibious species. Filter feeding animals generally possess large amounts of these neurotoxins. The tunicates are sessil marine animals with a high rate of sea water filtration. The tunics and siphons of 50 specimens of Phallusia nigra were dissected and the visceral organs were immersed in methanol containing acetic acid 0.02 N ph 5.0. The extract was prepared by homogenization, filtration and the methanolic phase was concentrated under reduced pressure and defatted with chloroform. The polar phase was evaporated and the residue dissolved in deionized water for further purification in ionic-exchange resin column (Bio-Gel P-2) and HPLC analysis. The extract showed paralytic effects on mouse assay (26.9 MU/100mg) and on crustacean isolated nerve preparations. The chemical analysis for TTX and PST revealed toxins with retention times similar to gonyautoxins, saxitoxins and TTX. These findings are important to explain future toxin envenoming outbreaks on the Brazilian coast.

Caquexia cancerosa em modelo experimental rato nude atímico/tumor humano KB / Cancerous cachexia in athymic nude rat experimental model/human tumor KB

1. Newborn anthymic nude rats, innoculated with KB human tumor, normally develop a great level of tumoral taken. With the augmentation in volume of the tumoral mass, animals may enter in a cachetic state that leads them to death. 2. However, proportionally to the total of days of observation, the number of rats that enter in cachexia was significantly greater than in the group that did not develop growth of tumoral mass post-innoculum. 3. This fact may suggest that any factor produced by the organism, in an excessive amount, with the aim to hinder the development of the tumoral mass, ha d a parallel effect strondgly cachetizing. 4. Relevant is the fact that the production of this substance may be thymus-independent, since these animals are congenitally athymic

Flavivirus infections in Chiang Mai area, Thailand, in 1982.

Infection by JE virus still constitutes major cause of encephalitis in Chiang Mai Area, although some cases of possible dengue encephalopathy were observed. In spite of many apparent encephalitis cases, infection of vector mosquitoes by JE virus was not demonstrated. Virus isolation from hospitalized patients showed that the principal type of dengue virus circulating in Chiang Mai in 1982 was type 1 virus. Seroepidemiological survey on healthy humans indicated that the northern part of Chiang Mai Province in the region of the Maekong Valley has not yet been invaded so much by dengue viruses, compared with the Chiang Mai Valley, where dengue infection apparently became more prevalent than 12 years ago. The survey also indicated that the spread of JE virus in the study area was not uniform. Survey on vertebrates showed that anti-JE antibodies were highly prevalent among swine, horses, mules, sheep, and dogs. On the other hand, antibody prevalence was low in monkeys, ducks, and sparrows, and was negative among chickens and lizards. IgM-ELISA appeared to help differential diagnosis on JE from dengue even when the HI test did not give positive results.