[Foot-and-mouth disease in buffaloes (Bubalus bubalis, Linnaeus, 1758): search of antiantigen antibodies and isolation of the virus]. / Febre aftosa em búfalos (Bubalus bubalis, Linnaeus, 1758): pesquisa de anticorpos antiantígeno VIA e isolamento do vírus.

The immune response to virus-infection-associated (VIA) antigen was studied in 379 Indian buffalos (Bubalus bubalis). These animals were vaccinated three times a year with commercial acetylethyleneimine (AEI)--inactivated foot-and-mouth disease vaccines under field conditions. Two months after the last vaccination, antibody against virus-infection-associated (VIA) antigen was found in 23 per cent. Foot-and-mouth disease virus -- (FMDV) type C "Waldmann" was isolated from oesophageal/pharyngeal fluid of 7 samples buffalos.

[Isolation of bovine cell lines and susceptibility to foot-and-mouth disease virus]. / Isolamento de linhagens celulares bovinas e suscetibilidade ao vírus da febre aftosa.

Morphology and chromosomes of cell sublines derived from two new bovine kidney lines are reported. Cell susceptibility to the foot-and-mouth disease virus is discussed. One of the sublines showed epithelial-like cells, while the remainder, elonged fibroblastic-like cells. Most of them had a diploid number of chromosomes. From these sublines only one was sensible to the foot-and-mouth disease virus.

[Effects of polyionic compounds in the plaque formation of different strains of foot-and-mouth disease virus (FMDV) in the swine cell line IB-RS-2]. / Efeitos de compostos poliiônicos na formação de placas por diferentes amostras do vírus da febre aftosa (FMDV) na linhagem celular suína IB-RS-2.

The effects of dithylaminoethyl (DEAE)-dextran (DD) and dextran-sulfate (DS) were studied in some strains of the foot-and-mouth disease virus (FMDV). The strains ASQ-PG, CR and O, large plaque variants in IB-RS-2 cells, when DD or DS were added to the agar overlay, the plaques were inhibited. However, the strains ASQ-Pp and CI, that are small plaque variants in IB-RS-2 cells, when to the agar overlay was added DD the plaques were greatly enhanced while when was added DS the plaques were inhibited.

[Presence of virus-like particles in clonus C-13 and C-26-3 of swine cell line IB-RS-2]. / Presença de partículas semelhantes a vírus nos clones C-13 E C-26-3 da linhagem celular suína IB-RS-2.

Virus-like particles resembling those seen in baby hamster kidney (BHK-21) cell cultures, CK-bovine cells, pig kidney cell lines PK-13 and IB-RS-2 have been found in the clones C-13 and C-26-3 of the cell line IB-RS-2. The particle's average outer diameter is c.85nm and the core is c.53nm

[Ultrastructure of Mycoplasma sp. demonstrated by phosphotungstic acid-chromic acid pH 0,4]. / Ultraestrutura de Micoplasma sp. revelada pelo ácido fosfotúngstico-ácido crômico pH 0,4.

Ultrastructural observation of Mycoplasma sp. revealed by the phosphotungstic acid-cromic acid, pH 0,4. Arq. Inst. Biol., São Paulo, 45(3) :169-176, 1978. Cells of IB-RS-2 (clone C-26-3) swine line were examined under electron microscopy, employing the differential coloration with PTA-ACr 5 %, pH 0,4, during 30 minutes, at 37 degrees C. Through this method we could observe the intracitoplasmatic forms, electronically dense, rather pleomorfic, with sizes varying between 60nm and 640nm and a unitary membrane of 90A similar to the extracellular forms described as Mycoplasma sp.

[Effects of polyionic compounds on the metabolism of the swine cell line IB-RS-2]. / Efeitos de compostos poliônicos sobre o metabolismo de células da linhagem suína IB-RS-2.

The effects of polyons DEAE-dextran and dextran sulfate on IB-RS-2 cells were studied. DEAE-dextran (5 microgram/ml) inhibited cell growth and decreased the synthesis of proteins and RNA, while the synthesis of DNA remained essentially unchanged. Those effects depend on time of cell exposition to this compound. Dextran-sulfate (5 microgram/ml) increased cell growth, but inhibited protein synthesis and on a lesser extent the synthesis of RNA; those effects were seen 48 hours after the addition of Dextran-sulfate to the maintenance medium. The synthesis of DNA remained essentially unchanged.

[Serologic study of 2 strains of foot-and-mouth virus, cultured in cell line IB-RS-2, clone 26-3]. / Studo sorológico de z amostras do vírus da febre aftosa, cultivadas em células de linhagem IB-RS-2, clone 26-3.

The antigenic characteristics of the two FMDV plaque size variants ASQ-PG and ASQ-Pp were studied by serum neutralization kinetics. The results evidentiated that the antiserum ASQ-PG and ASQ-Pp neutralized both variants at the same extent. The plaque population of these variants after passage in laboratory animals was compared in IB-RS-2 cells.