RC-IAL cell line: sensitivity of rubella virus grow.

OBJECTIVE: The rapid growth of the rubella virus in RC-IAL2 with development of cytopathic effect, in response to rubella virus infection, is described. For purposes of comparison, the rubella virus RA-27/3 strain was titered simultaneously in the RC-IAL, Vero, SIRC and RK13 cell lines. METHODS: Rubella virus RA-27/3 strain are inoculated in the RC-IAL cell line (rabbit Kidney, Institute Adolfo Lutz). Plates containing 1.5x10(5) cells/ml of RC-IAL line were inoculated with 0.1ml s RA-27/3 strain virus containing 1x 10(4)TCID50/0.1ml. A 25% cytopathic effect was observed after 48 hours and 100% after 96 hours. The results obtained were compared to those observed with the SIRC, Vero and RK13 cell lines. Rubella virus was detected by immunohistochemistry. RESULTS: With the results, it was possible to conclude that the RC-IAL cell line is a very good substrate for culturing rubella virus. The cells inoculated with rubella virus were examined by phase contrast microscopy and showed the characteristic rounded, bipolar and multipolar cells. The CPE in RC-IAL was observed in the first 48 hours and the curve of the increased infectivity was practically the same as observed in other cell lines. CONCLUSIONS: These findings are important since this is one the few cell lines described in the literature with a cytopathic effect. So it can be used for antigen preparation and serological testing for the diagnosis of specific rubella antibodies.

[Comparison of methods to test the "in vitro" cytotoxicity of biocompatible materials]. / Comparação de métodos para testar a citotoxicidade "in vitro" de materiais biocompatíveis.

OBJECTIVE: A comparison of the sensitivity of the agar diffusion method with that of extraction using cell-lines RC-IAL (fibroblastic of rabbit kidney) and HeLa (epithelial carcinoma cells from the cervix uteri of the human uterus), in the in vitro evaluation of materials of medical and hospital. MATERIALS AND METHODS: Fifteen samples chosen at random, from among the already known positives and negatives in our stock, were tested and identified as cotton, form, latex, cellulose and acrylic. Besides the samples mentioned, many SDS (GIbco) concentrations were tested experimentally in RC-IAL and HeLa cell cultures. RESULTS: Of the 50 samples tested, 44(88%) were positive by both methods. However, when the SDS were compared by using the two methods, positive results were noted in the concentrations of from 0.5 to 0.05 microgram/ml in the agar diffusion ans extraction methods. A cytotoxic effect was only noted in the concentrations of up to 0.25 microgram/ml. CONCLUSION: When the SDS was used, differences favorable to the agar diffusion method were observed in the two cell lines, in two concentrations; that is, the sensitivity of this method was quantitatively greater on inspection than that of the extraction method, as well as being the simpler method to use.

[RC-IAL: rabbit kidney continuous cell line--characteristics and substrate for viral replication]. / RC-IAL: linhagem celular contínua de rim de coelho--características esubstrato para replicação de vírus.

A rabbit kidney cell line RC-IAL, isolated in 1976 and at present at 150a passage, has had its characteristics analysed. The cells presented morphology similar to fibroblasts throughout their culture. The cellular growth proportion remained unaltered from its isolation, with a cloning efficiency of around 9%. The line showed growth dependent on anchorage and chromosomic analysis presented the modal number of the species with small variations to about one chromosome, to a total of about 50%. The line's species of origin was confirmed through indirect immunofluorescence reaction and susceptibility to some viruses with cytopathic effect was verified with vaccinia, cowpox, herpes simplex types 1 and 2 and rubella viruses. This cellular substract is free from contaminating agents, thus satisfying the conditions for its use in scientific work, especially that relating to public health.

Serologic studies on the behaviour of influenza virus type A in persons of greater Säo Paulo during 1976, 1978 and 1979

Foram estudados soros de pessoas de diferentes grupos etários coletados em 1976, 1978 e 1979 para verificar a presença de anticorpos inibidores da hemaglutinaçäo contra diversas estirpes de vírus da influenza A dos subtipos H3N2 e H1N1. A ocorrência da infecçäo pelo subtipo H3N2 foram detectados em 1976 e 1978 mas em 1979, a circulaçäo desse subtipo de vírus foi limitada. A prevalência de anticorpo contra A/Säo Paulo/1/78 (H1N1) foi significativamente maior do que para A/USSR/90/77 (H1N1) em 1978. No entanto em 1979, a estirpe predominante foi A/USSR/90/77 (H1N1). As pessoas com idade inferior a 20 anos foram as mais afetadas pelo subtipo H1N1, enquanto que indivíduos com mais de 20 anos já apresentavam anticorpos para esse subtipo em 1976, antes do resurgimento dessa estirpe. A infecçäo pelo vírus H3N2 em 1978 ocorreu em 65,4% de crianças do grupo etário de 0-4 anos; 47,0% de criancas do mesmo grupo tinham anticorpos para vírus H1N1 em 1979. Anticorpos para o vírus da influenza suina foram detectadas em 60% de pessoas com mais de 60 anos de idade

WHO collaborative study on the sero-epidemiology of rubella in Caribbean and Middle and South American populations in 1968.

Knowledge of the rubella antibody profiles of female populations of various ages and in various geographical areas is essential for an intelligent and effective administration of rubella vaccine. The investigation reported was undertaken to extend a previous WHO collaborative study to include additional areas of the Americas. As in the other mainland areas included in the earlier study, the presence of rubella haemagglutination-inhibiting antibody was found to be a likely event in over 80% of the females of child-bearing age in Argentina, Brazil, Chile, urban Peru (Lima) and Uruguay. Antibody rates were significantly lower in Jamaica, Panama, rural Peru and Trinidad. These data confirm and extend earlier findings of low levels of rubella immunity in certain island or isolated populations.