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Biomedical subjects

J Svejcar

Publications and source records attributed to J Svejcar.

At least 37 records · Page 2Linked to original sources

Biochemical abnormalities in connective tissue of osteodysplasty of Melnick-Needles and dyssegmental dwarfism.

Biochemical findings in the connective tissue of two rare genetic skeletal dysplasias are reported. Osteodysplasty of Melnick-Needles showed an increased content of collagen; its increased synthesis may be the expression of the sclerosing process. In the neonatally lethal dyssegmental dwarfism, abnormal gel electrophoretic patterns of collagen peptides were found. These point to a deficiency in alpha 1-chains which may be the cause of an increase in cross-linking with a change in cleavage and extractibility of collagen.

Bone Diseases, Developmental↗

In vitro cellular immune response to homologous and heterologous antigens in rabbits sensitized by five species of Mycobacterium and Nocardia asteroides.

Rabbits were sensitized with killed Mycobacterium tuberculosis, M. kansasii, M. avium, M. scrofulaceum, M. fortuitum, and Nocardia asteroides, and their response to homologous and heterologous antigens was assessed in vitro by direct and indirect macrophage migration inhibition tests. The antigens were obtained by disintegration of bacterial mass and by purification of the supernatants by ultracentrifugation. In the direct test, hypersensitivity to homologous antigen was most marked with M. tuberculosis, M. kansasii, and M. avium (migration indices [MI] = 0.42 to 0.50), but was significantly weaker with organisms possessing a lower degree of pathogenic activity (MI for M. fortuitum and N. asteroides = 0.70 and 0.72, respectively). Reactivity to heterologous antigens was also highest in animals sensitized with strongly pathogenic species, approximating normal values in rabbits sensitized with weak pathogens. In the indirect test, the strongest responses were obtained again to homologous antigens (MI = 0.42 to 0.67), and they differed more markedly from reactions to heterologous antigens than in the direct test. The weakest activity of heterologous antigens was again found with M. fortuitum and N. asteroides, where MIs were 0.82 to 0.93.

Animals↗

[Dyssegmental dwarfism--report on two cases (author's transl)].

Report on 2 cases of dyssegmental dwarfism, a rare lethal form of dwarfism. Both male newborns died from asphyxia immediately after delivery. Its features are malformations of the first visceral arch (Pierre-Robin-Syndrome) malformations of all extremities (Camptomicromelia) and severe malformations of the spine (Anisospondyly), with the vertebral changes serving as the main differential diagnostic feature. Among other things, these malformations are due to defective enchondral ossification; and the disease is presumably autosomal recessive.

Abnormalities, Multiple↗

In vitro studies of cell-mediated immunity in rabbits sensitized with Mycobacterium kansasii and Mycobacterium tuberculosis.

Rabbits, sensitized with M. kansasii, responded by a profound inhibition of migration of macrophages elicited by both antigens: the migration index for homologous antigen was 0.51 in the direct test and 0.65 in the indirect test; for heterologous antigen the indexes were 0.53 and 0.67. However, significant differences in reactivity were found in rabbits sensitized with M. tuberculosis. In the homologous system, high reactivity was maintained and the migration index reached the value of 0.53 in the direct and 0.63 in the indirect test. On the other hand, the heterologous antigen M. kansasii influenced the migration in both direct and indirect assays significantly less, the migration indexes being 0.62 and 0.72. The differences were statistically significant at 1% and 5% levels.

Animals↗

Cell-mediated immunity to varicella-zoster virus as assessed by the migration inhibition test.

The migration inhibition method was used to test cell-mediated immunity to varicella-zoster (VZ) virus in 10 varicella and 11 herpes zoster patients. Control groups consisted of eight children susceptible to VZ infection on serological evidence and 49 normal persons of different age categories. Depending on the positivity criterion adopted, positive results during disease were obtained in 43% or 90% or all tests performed in varicella patients and 47% or 74% in herpes zoster patients. Irrespective of which criterion of positivity was applied, a high rate of positive results was obtained in the normal control groups; in the age range from 20--44 years it was comparable to that for patients. This finding would suggest a high activity of VZ virus among the human population. Since a positive result in migration inhibition test offers evidence of recent contact with antigen, either exogeneous contact with VZ infection or endogenous contact with latent VZ virus must have been involved.

Adult↗