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Biomedical subjects

J Robinson

Publications and source records attributed to J Robinson.

At least 523 records · Page 29Linked to original sources
PubMed1975

Aminocentesis: its impact on mothers and infants. A 1-year follow-up study.

In a 1-year follow-up study, the effects of amniocentesis for genetic diagnosis upon 22 infants and their mothers were assessed. The infants were tested at 1 year of age on the Bayley Infant Scale of Mental and Motor Development. No deviations from normal mental or motor development were found. The mothers were interviewed at the same time, in order to better understand the emotional aspects of the experience. Women between ages 35-39 with no previously affected child tended to accept amniocentesis easily, as an appropriate part of parnatal care. Mothers with a previous defective child tended to have more painful emotional reactions, including higher anxiety over the test and more conflict about a possible abortion. They needed more intensive and extended counseling. We suggest that the issue of abortion is important, even if manageable by most women, and that a chance to discuss it may be significant.

Abortion, Therapeutic↗
PubMed1975

Assay for Epstein-Barr virus based on stimulation of DNA synthesis in mixed leukocytes from human umbilical cord blood.

Relationships between the rate of DNA synthesis in cultured human umbilical cord leukocytes and the multiplicity of added Epstein-Barr virus (EBV) were studied. At low multiplicities of approximately 0.1 transforming units/cell (approximately 10 physical particles/cell), inoculated cultures demonstrated increased rates of DNA synthesis, by comparison to uninoculated cultures, 3 days after inoculation. Stimulation of DNA synthesis was evident of progressively longer intervals after inoculations of 10-fold dilutions of virus. The rate of DNA synthesis, determined by short [-3H]thymidine pulses, reflected as small as twofold changes in multiplicity and thus can serve as a quantitative assay for the virus. Changes in the rate of DNA synthesis were evident before increases in cell number or alteration in morphology. Stimulation of DNA synthesis in umbilical cord leukocytes was inhibited by treatment of EBV with antibody and also in graded fashion, by progressive doses of UV irradiation to the virus. Induction of DNA synthesis by EBV was serum dependent. Estimates of the number of cells transformed were obtained by extrapolation from a standard curve relating known numbers of transformed cells to [-3H]thymidine incorporation and also by cloning cells after exposure to virus. At the low multiplicities of infection used in these experiments approximately 0.04 to 0.002 of the total cellular population was transformed. The high efficiency of cell transformation by EBV by comparison to other DNA tumor viruses is emphasized.

Antiviral Agents↗
PubMed1975

Differences between laboratory strains of Epstein-Barr virus based on immortalization, abortive infection and interference.

Biological activities of extracellular Epstein-Barr virus (EBV) from two laboratory strains, namely P3J-HR-1 (P-H) from Burkitt's lymphoma and B95-8 (B95) from infectious mononucleosis, were compared. Virus stocks from both sources contained approximately the same number of virions. Virus from the P-H line induced early antigen in six non-producer EBV-genome carrier cell lines; virus from B95 did not induce early antigen. Extracellular virus from B95 regularly caused lymphocytes from human umbilical cords to form continuous lines (immortalization); P-H virus did not cause primary cultures of human lymphocytes to grow continuously. B95 virus stimulated DNA synthesis, as determined by the rate of incorporation of 3H-thymidine into acid-insoluble material; P-H virus did not stimulate DNA synthesis. Pretreatment of lymphocytes with undiluted P-H virus inhibited immortalization and stimulation of DNA synthesis by B95 virus. The inhibitory properties of the P-H virus were sedimented at 100 000 g and inactivated by heat and UV irradiation; interference by the P-H virus was neutralized by human serum with antibody to EBV and not by antibody-negative human serum. The hypothesis most consistent with these results is that the P-H virus is defective in gene(s) needed for initiation of immortalization. We speculate that the absence of this gene allows early antigen to be expressed upon superinfection of non-producer cell lines. The availability of two laboratory strains of two laboratory strains of EBV that differ in biological behaviour provides starting material for analysis of the mechanism of lymphocyte immortalization by EBV and of virus structural differences that affect immortalization.

Animals↗
PubMed1974

Differences between laboratory strains of Epstein-Barr virus based on immortalization, abortive infection, and interference.

Biologic activities of extracellular Epstein-Barr virus (EB virus) from two laboratory strains, namely, P(3)J-HR-1 (P-H) from Burkitt lymphoma and B95-8 (B95) from infectious mononucleosis, were compared. Virus stocks from both sources contained approximately the same number of virions. Virus from the P-H line induced "early antigen" in six nonproducer EB virus genome carrier cell lines; virus from B95 did not induce "early antigen." Extracellular virus from B95 regularly caused lymphocytes from human umbilical cords to form continuous lines (immortalization); P-H virus did not cause primary cultures of human lymphocytes to grow continuously. B95 virus stimulated DNA synthesis as determined by rate of incorporation of [(3)H]thymidine into acid-insoluble material; P-H virus did not stimulate DNA synthesis. Pretreatment of lymphocytes with undiluted P-H virus inhibited immortalization and stimulation of DNA synthesis by B95 virus. The inhibitory properties of the P-H virus were sedimented at 100,000 x g and inactivated by heat and UV irradiation; interference by the P-H virus was neutralized by human serum with antibody to EB virus and not by antibody-negative human serum. The hypothesis most consistent with these results is that the P-H virus is defective in gene(s) needed for initiation of immortalization. We speculate that the absence of this gene allows early antigen to be expressed upon super-infection of nonproducer cell lines. The availability of two laboratory strains of EB virus which differ in biologic behavior provides starting material for analysis of the mechanism of lymphocyte immortalization by EB virus and of virus structural differences which affect immortalization.

Antigens, Viral↗