[Photosensitivity and stability of freeze-dried and/or reconstituted measles vaccines (Biken CAM-70 strain)]. / Fotossensibilidade e termoestabilidade de vacinas contra o sarampo (cepa Biken CAM-70) liofilizadas e/ou reconstituídas para administração.

Three different lots of measles vaccines produced with the Biken CAM-70 virus strain were requested from the central cold store of the Public Health Department of the State of S. Paulo, Brazil, and assays on photosensitivity at 2-8 degrees C, and on stability at 28, 36.5 and 45 degrees C were carried out to find out for how long these vaccines would maintain their minimum potency, established as being 3.70 log10 or 5000 TCID50 (50% tissue culture infective dose) per human dose. The analysis of the adjusted straight regression lines indicated that, with the passage of time, the potency of lyophilized or reconstituted vaccines, as well as of vaccines exposed to or protected from light decreased. Light-exposed vaccines, however, became less potent than vaccines protected from the light. None of the vaccine lots studied, reconstituted and stored at 2-8 degrees C, exhibited homogeneity as to sensitivity to light. When freeze-dried vaccines had their photosensitivity studied at 2-8 degrees C, lots 1 and 2 presented greater thermal degradation when exposed to light than when protected from it. However, in both instances, it was found that potency fell below that taken as minimum for the Biken CAM-70 virus strain. At all other temperatures considered, even when protected from light, lots 1 and 2 did not retain the minimum potency. Lot 3 kept the expected stability for 60 days at 2-8 degrees C when protected from light and for 40 days when unprotected, but its thermal degradation at other temperatures was more intense (28 degrees C: 5 days; 36.5 degrees C: 2 days; 45 degrees C: 0.5 day).(ABSTRACT TRUNCATED AT 250 WORDS)

[Mycoplasma as a contaminant of cell cultures maintained in laboratories of private and official institutions]. / Micoplasma como contaminante de culturas celulares mantidas em laboratórios de instituições particulares e oficiais.

Mycoplasma is one of the most serious contaminants of cell cultures. Its detection is very important in virology, as well as its eradication. The aim of this study was to verify the incidence of mycoplasma in cell lines maintained in seven laboratories of private, government and college institutions of the State of São Paulo, Brazil, for the purposes of research, production of reagents for diagnosis and production of biologicals for human and animal use. Of the 29 cell lines, eight were derived from human tissues and 21 from other animal species (dog, rabbit, mouse, hamster, monkey, pig, chicken and ox). Using the direct method with specific liquid and solid media for detection of mycoplasma, 48 out of the 106 cell samples tested were positive, corresponding to a contamination index of 45.28%. The incidence of contamination among the 35 cell samples of human origin was 51.43% (18 positive). Of the 71 samples originated from other species, 30 were positive (42.25%). The high incidence of contamination found calls for the adoption of measures for the prevention of this hazard: the elimination of mouth pipetting, the use of aseptic techniques and a rigid control of trypsin, serum and other components of cell culture media. The substitution of mycoplasma-free cultures for all contaminated ones and the performance of periodical tests for mycoplasma detection must also be carried out to prevent and avoid the dissemination of these organisms. Data obtained showed that contamination appeared in the 2nd (72.92%), in the 3rd (20.83%) and in the 4th passage (6.25%).(ABSTRACT TRUNCATED AT 250 WORDS)

Sorbitol-gelatin and glutamic acid-lactose solutions for stabilization of reference preparations of measles virus.

The work reported here sought to assess the protection afforded by two stabilizing solutions (sorbitol-gelatin and glutamic acid-lactose) in preserving the potency of freeze-dried Schwarz strain measles virus during storage with a view to the production of reference preparations and working lots of virus suspensions. Stabilized virus suspensions and control suspensions were stored at -70 degrees C or were freeze-dried and stored at -20 degrees C, and their potency was determined over a storage period of 21 months. It was found that the sorbitol-gelatin imparted more satisfactory stability (r = +0.18) to the freeze-dried virus suspensions than did the glutamic acid-lactose. The results also indicate that sorbitol-gelatin, used under the conditions of this study, is an effective stabilizer in the preparation of freeze-dried suspensions of Schwarz strain measles virus employed as reference preparation working lots.

Potency control of live, attenuated vaccines against measles used in children vaccinations in the State of Sao Paulo, Brazil (1976-1980).

Pela inoculacao de diluicoes seriadas da vacina viva, atenuada, contra o sarampo,em culturas de celulas Vero, foram titulados para controle de potencia, 161 lotes de vacinas importadas da Inglaterra, Franca e Belgica, destinadas a vacinacao da populacao infantil do Estado de Sao Paulo. Nas condicoes do teste, 20,0, 11,5 e 25,0% dos lotes de vacina testadas, importadas da Inglaterra, Franca e Belgica respectivamente, nao apresentaram o titulo minimo exigido; dentre os 72 lotes importados da Franca e liofilizados no Brasil, nao ocorreram impugnacoes devidas a insuficiencia de titulo