[A comparison of serological methods and their use in the diagnosis of enzootic bovine leukemia]. / Porovnání nekterých sérologických metod a jejich vyuzití v diagnostice enzootické bovinní leukémie.

ELISA method with polystyrene micro-plates and rods was compared with the neutralization test in plaque modification (SN) and with the immunodiffusion method (ID). Micro-plates are the best for the adsorption of the virus, mainly in quantitative studies. In screening examinations it is also the diagnostic rods that give results comparable with the SN method. In the modified ELISA method, dubious results should also be regarded as diagnostically important. In mass examination, ELISA test can be considered as an alternative to the neutralization test. As demonstrated, the titres of antibodies from 80 to 100 determined by ELISA method in micro-plates or by the SN test represent the marginal titres of the positivity of ID test. The ELISA method is suitable mainly in the final stages of the sanitation of herds since infected animals are revealed with a high sensitivity and in time.

[Demonstration of immunoglobulin levels in aborted bovine fetuses in relation to the results of histological, microbiological and viro-serological investigations]. / Prukaz hladin imunoglobulinu u abortovaných fétu skotu ve vztahu k výsledkum histologického, mikrobiologického a virologicko-sérologického vysetrení.

In the pectoral body fluid or in the stomach contents of 63 aborted foetuses, IgG and IgM was demonstrated in 38 foetuses from the fourth month to the end of pregnancy. Out of the 38 foetuses in which immunoglobulins were found to be present, 23 had a positive bacteriological finding. In one case in which Streptococcus agalactiae was isolated, neither IgG nor IgM was found. In the foetuses with a positive bacteriological finding, IgG was found in the body fluid at the average level of 36.75 mg in 14 foetuses, and in the stomach contents at the average level of 17.48 mg per 100 ml in 17 foetuses. IgM was detected in nine foetuses, and in two cases the average level was 7.16 mg and 12.6 mg per 100 ml. In the foetuses with a negative bacteriological finding IgG was found in 14 body fluid samples at the level of 15.06 mg, and in nine foetuses IgG was present in the stomach contents at the level of 17.26 mg per 100 ml; IgM was found in three body fluid samples at the average level of 14.12 mg per 100 ml. Antibodies were demonstrated in the PI3 virus in 28 foetuses and in the BVD-MD virus in 35 foetuses. The serological examination with other antigens was negative. A suspected and positive histological finding was obtained in 30.2% of the foetuses studied. Immunoglobulins were detected in 43.5% of the foetuses with a positive and suspected histological finding. Immunoelectrophoretic examination revealed IgG in 24 foetuses and IgM in 12 foetuses. Transferrin was not demonstrated in nine foetuses at the age from the fifth to the seventh month of pregnancy. Albumin, alpha, and beta-globulins were demonstrated to be present in all foetuses.

[Cell culture preservation by automatic freezing in the adapted Höppler ultrathermostat of the NBE type]. / Konzervace bunecných kultur automatickým mrazením na upraveném ultratermostatu Höppler typu NBE.

A description is presented of an adapted ultrathermostat, respecting the requirement for a continuous decrease in temperature by 1 degree C per minute, as necessary for keeping the frozen cultures alive. Viability was evaluated in the primary cells of calf kidneys in the first subpassage and permanent cell lines PK and TL 72 after their freezing and preservation at -192 degrees C for 30 days. In comparison with regularly passaged cultures, the frozen cells had a high viability.

[Corticoid activation of infectious bovine rhinotracheitis virus--infectious pustular vulvovaginitis virus (IBR-IPV)]. / Aktivace viru infekcni bovinni rhinotracheitidy--infekcni pustulárni vulvovaginitidy (IBR-IPV) kortikoidy

The course of infection and IBR virus reactivation was studied in three experimentally infected weaned calves and three cows from naturally invaded herds. The animals were infected intranasally, intratracheally, and by contact. After 20, 41, and 105 days from primary infection, both in calves and in cows, dexametazon was applied in a series of six to seven intramuscular injections. The presence of the virus was examined in the nasal, conjunctival, vaginal and/or preputial secretions and in blood on diploid cells of calf kidneys and by the immunofluorescence method. In all infected calves, the disease took place with clinical signs of rhinotracheitis, mostly within the period of nine days. The second and third day after a temperature rise, the virus titre in nasal secretion reached the values ranging from 10(5) to 10(6.5). A markedly lower titre was obtained in the conjunctival secretion 10(0.5) to 10(3.5). In blood, the virus was found to be present on the first and fifth day from infection. After dexametazon application the calves and cows eliminated the virus mainly with the nasal secretion whose titre highly rose to the value of 10(3.5) to 10(47). In the conjunctival secretion the virus was present only irregularly and its quantities were very small. The greatest quantities of the virus were found in the nasal secretion on the sixth to the eight day from dexametazon application. The virus was not found in vaginal and preputial secretions. The levels of neutralizing antibodies were not affected by dexametazon in the calves; in cows they rose significantly from the titres of 1:2--1:4 to the titres of 1:16--1:32.

[Comparison of the sensitivity of laboratory animals and tissue cultures to infection with Aujeszky's disease virus]. / Porovnání vnímavosti laboratorních zvírat a tkánových kultur k infekci virem Aujeszkého choroby

In mice and guinea-pigs high susceptibility was demonstrated following i. c. administration of the virus, approximately equalling to that of rabbits and tissue cultures. Also a relatively high susceptibility of guinea-pigs was demonstrated, with very distinct clinical symptoms of the disease, as compared with mice and rats after the other manners of infection. On the basis of the results obtained white mice were utilized for routine diagnostic of Aujeszky disease. After i. c. administration of positive, virus-containing material encephalitis develops with a rapid exitus occurring 12-24 hours earlier than in the rabbits. In brain tissue antigen was always demonstrated by immunofluorescence examination. Along with the biological experiment replicas of pig organs were examined by immunofluorescence method. Maximum of positive yellow-green fluorescence is found in the cytoplasma of epithelial tonsillar cells, sporadically in the cell nuclei. Epithelial cells are deformed according to the infection degree. The amount of antigen in the brain tissue is not so pronounced as in the tonsillar tissue, yet in animals with clinical pathological symptoms the antigen was always demonstrated.