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Biomedical subjects

R Sohier

Publications and source records attributed to R Sohier.

At least 37 records · Page 2Linked to original sources
PubMed1975

Nasopharyngeal carcinoma. IX. Antibodies to EBNA and correlation with response to other ebv antigens in chinese patients.

Ninety-five sera from Chinese NPC patients in different stages of the disease, 38 sera from Chinese patients with other cancers, and 50 normal Chinese sera, were titrated for EBNA, VCA, EA and complement-fixing (CF/S) EBV-specific antibodies. The geometric mean (GMT) EBNA antibody titre of patients with NPC at stage I was found to be four times higher than that of normal individuals and increased in parallel with clinical deterioration. Antibody titres against EBNA did not correlate with either VCA or EA antibodies but, in general, correlated with CF/S antibodies. EA antibodies correlated relatively well with VCA antibodies and discriminated better than EBNA titre between NPC at stage I and controls.

Antibodies, Viral↗
PubMed1975

Sero-epidemiology of the Epstein-Barr virus: preliminary analysis of an international study - a review.

Samples of Chinese, Indian, African and Caucasian populations, randomly selected in Hong Kong, Singapore, the West Nile District of Uganda, and Nancy, France, were titrated for antibodies to EBV, viral capsid (VCA) and complement-fixing soluble (CF/S) antigens. The age-specific prevalence of infection (as reflected by the proportion of VCA-positive individuals) varied greatly up to the age of 10 years in the four populations studied, the West Nile District of Uganda being outstanding in having an early and massive infection rate. Differences were also observed between ethnic groups in Singapore, where the Chinese appeared to have a delayed infection rate compared to the Indians. Immune response, as measured by the prevalence of CF/S antibodies and by the geometric mean titres (GMT) of VCA and CF/S antibodies, differed significantly between ethnic groups, Ugandan infants (1-3-year age-groups) having a humoral response to VCA and CF/S antigens as high as or higher than that of Burkitt's lymphoma patients, decreasing thereafter to levels lower than those of any other ethnic group observed. Indians in Singapore, known to be at no risk for NPC and BL, exhibited a higher and steadier immune response to VCA in going from young to old age-groups than did the Chinese.

Adolescent↗
PubMed1974

Persistence of Adenovirus 5 in guinea pigs.

One intracardiac inoculation of adenovirus 5 in guinea pigs leads to virus persistence in different organs, viz., 5 days in lungs and liver, 14 days in blood and lymph nodes, and 56 days or more in the spleen. After cultivation of tissue cells for 1 week, virus was recovered from blood, lymph nodes, or spleen lymphocytes, but virus could be detected directly in cells only when organs were removed within 48 h of inoculation. To determine how the virus persisted in low concentrations and as a latent infection, spleens were primarily selected for study by three techniques: homogenization of spleens, suspended Maitland fragment cultures, and in vitro cultivation of spleen cells. The last procedure showed virus in fibroblast-like cells (probably macrophages or reticuloendothelial cells) for 56 days after infection of guinea pigs. With other methods, the virus was found only within the first 2 days after inoculation.

Adenoviridae↗
PubMed1974

The variability in immunofluorescent viral capsid antigen antibody tests in population surveys of Epstein-Barr virus infections.

A comparative study of the extent of Epstein-Barr virus (EBV) infections in populations that differ with respect to the incidence of tumours associated with this virus is now in progress in different countries. In these surveys of antibody titres from the various study populations, it is of critical importance that strict comparability be maintained. Despite standardization of techniques and reagents in the cooperating laboratories, considerable variation in the results has remained. The components of the total variability in the results of the immunofluorescence test for estimating the antibody titres against viral capsid antigens (VCA) of the EBV have been investigated. With repeated tests on the same sera, four sources of variation were measured: the reading of the slides, the performance of the tests, the use of various batches of the same cell line as antigen, and the use of different cell lines. The greatest variations were due to the use of different cell lines and to differences in performing the test; the reading of the slides caused only minor variations. Both the systematic and unsystematic variations were measured. The systematic variation was great in tests between laboratories and when different cell lines were used as antigens. Most of the systematic variation resulting from the use of different cell batches from the same cell line could be accounted for by the differing proportions of brilliant fluorescent cells. Adjustments are possible to correct the systematic variation whenever this has been measured, but not the unsystematic "residual" variability, which presents the real obstacle to the comparison of results obtained in different laboratories or by different observers. To attain full comparability of VCA antibody tests the sera from the different surveys should all be tested in the same laboratory.

Analysis of Variance↗
PubMed1974

Comparison of the immune response of the rabbit to virulent and attenuated strains of type 1 poliovirus.

Rabbits were immunized with the attenuated LSc, 2a(1)b or the virulent Mahoney strain of type 1 poliovirus, or with a partially purified preparation of the latter. It was found that the animals responded in a heterogeneous manner to antigens with a homogeneous virion population, such as LSc,2a(1)b and, to a lesser extent, the partially purified Mahoney antigen. This heterogeneous immune response permits the preparation of specific antisera for intratypic serodifferentiation tests. However, the unpurified Mahoney strain, which has a heterogeneous virion population, induced a homogeneous immune response; all the antisera had a wide spectrum of antibodies and could not distinguish the wild from the attenuated strain. The differentiation capacity of the specific antisera was found to be linked to either the IgM or the IgG. The possible implications of these findings for human vaccination against poliomyelitis are discussed.

Analysis of Variance↗
PubMed1973

Enterovirus type 70: the etiologic agent of pandemic acute haemorrhagic conjunctivitis.

A new enterovirus, now classified as enterovirus type 70, was isolated from the conjunctiva of patients with acute haemorrhagic conjunctivitis during the 1971 epidemics that occurred in Japan, Singapore, and Morocco. These epidemics were parts of a pandemic involving Africa (Algeria, Ghana, Morocco, Nigeria, and Tunisia), Asia (Cambodia, China (Province of Taiwan), Hong Kong, India, Indonesia, Japan, Malaysia, the Philippines, Singapore, and Thailand), and England during 1969-71. A representative strain from each of the three epidemic areas was studied cooperatively. The strains exhibited the physicochemical characteristics of enteroviruses. Cross-neutralization tests showed that these viruses were distinct from all known human enterovirus immunotypes, but that they were antigenically closely related. The human origin of the viruses was demonstrated by the appearance of homologous neutralizing antibodies during convalescence in patients with acute haemorrhagic conjunctivitis.

Acute Disease↗