Investigations on the presence of antibodies to papova viruses in patients with different forms of cancer and in other categories of patients or apparently healthy subjects. Note II. Hemagglutination-inhibiting serum antibodies to BK virus.

Hemagglutination-inhibiting serum antibodies to BK virus (BKV were detected in patients with different forms of cancer and in blood donors (positivity percentages: 67.04 and 57.78, respectively). No such antibodies were found in a group of children 1 to 14 years of age. The data point to the presence of a latent human infection with BKV in the population of Romania.

Investigations on the presence of antibodies to papova viruses in patients with different forms of cancer and in other categories of patients or apparently healthy subjects. Note III. Hemagglutination-inhibiting serum antibodies to polyoma virus.

Hemagglutination-inhibiting antibodies to polyoma virus could be detected in sera from apparently healthy subjects, patients with nonmalignant respiratory diseases and patients with different forms of cancer. The positivity percentages (12.97, 12.92 and 16.36, respectively) and the titers recorded were lower than in the case of BK virus. The results obtained suggest a slight antigenic relationship between polyoma and BK virus.

[Preliminary note on the circulation of some human respiratory viruses by wild birds]. / Note préliminaire sur la circulation de quelques virus respiratoires humains par l'intermédiaire des oiseaux sauvages.

With a view to detecting infections and carriage of human respiratory viruses in wild birds, 349 serum samples collected from 21 bird species -- sedentary ones and birds with large or limited migration areas -- were investigated. The following antigens were used: influenza virus A/Hong Kong 1/68 (H3N2)), A2 England 42/73 (H3N2), A2 Victoria 3/75 (H3N2), A/New Jersey 8/76 (HswN1), B/Hong Kong 5/72; parainfluenza virus type I Sendai and type II, coronavirus OC/43. An elevated incidence of antibodies to A2 Victoria 3/75 (H3N2) and parainfluenza type I virus was detected in herons (Ardea cinerea, Nyctycorax myctycorax). The high incidence of antibodies to B/Hong Kong 5/72 (30.7% of the samples exhibited significant titers) found in the crow (Corvus corone sardonius) is ascribed to the fact that this bird is carnivorus, feeding on corpses of mammals.

An antigen for the diagnosis of M. pneumoniae infections by passive hemagglutination.

The authors establish the optimal conditions (protein concentration, temperature) for the coupling of purified mycoplasma antigen to sheep red blood cells, in order to obtain an antigenic complex stable for at least 1 year. This comples allows specific determination by passive hemagglutination--a simple and rapid technique--of anti-mycoplasma antibodies in the sera of men or animals suspected of mycoplasma infections. Under the stated experimental conditions, antibody titers equal to or higher than 1/128 indicate an infection with M. pneumoniae.

Passive hemagglutination and complement fixation reactions in the early diagnosis of Mycoplasma pneumoniae infections.

Complement fixation (CF) and passive hemagglutination (PHA) tests (the latter with a M. pneumoniae antigen coupled by glutaraldehyde onto red blood cells) were performed in 263 patients with various infectious diseases (mostly in the 1st and 2nd week after onset) and non-infectious ones. CF reaction proved to be inappropriate for the early etiological diagnosis of mycoplasma infections, since the high titers were distributed undifferentially among the various patient groups and many sera (38%) showed anticomplementary activity. A PHA titer of at least 1/128 (preferably of 1/512) points to the presence of a M. pneumoniae infection, especially if clinical, radiological and laboratory data suggest a nonbacterial or mixed pneumonia. The diagnosis is often early enough to orientate the etiological therapy towards macrolides and tetracyclines. The PHA reaction recommended is specific, sensitive, reproducible and easy to perform.

Investigations on some antigenic relationships between different human, mammalian and avian Chlamydia strains.

Serological investigations were performed in order to establish the antigenic relationships between three Chlamydia strains: T44(subgroup A), T13 and Q18 (subgroup B). By using monospecific mouse immune sera a certain degree of antigenical relationships was made evident and the strains could be typed by microagglutination and microimmlnofluorescence reactions. Similar results were obtained by seroneutralization with hyperimmune sera prepared in the rooster. Complement fixation proved to be a group-specific reaction unable to reveal significant differences between the strains studied, not even with monospecific mouse sera. The antigenic relationships established between strains T44 (trachoma) and T13 (psittacosis) suggest the existence features common to subgroup A and B Chlamudia strains. The importance of typing Chlamudia strains with a view to specific prophylaxis is emphasized.

Preliminary investigations on the diagnostic value of passive hemagglutination and complement fixation tests in infections with Mycoplasma pneumoniae.

In order to evaluate the efficiency of passive hemagglutination (PHA) and complement fixation (CF) tests for the diagnosis of M. pneumoniae infections, 144 serum samples--out of which 81 from patients with respiratory and cutaneous infections and 63 from subjects with other diseases (controls)--were comparatively investigated by the two methods. The PHA test made evident a positivity index of 65% in the case of mixed pneumonias, as against 17% in controls, while the results obtained by CF were almost identical in the two groups investigated. The high specificity and sensitivity of the PHA reaction recommend this method for the diagnosis of acute M. pneumoniae infections.