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Biomedical subjects

J M Best

Publications and source records attributed to J M Best.

At least 127 records · Page 7Linked to original sources

Interferon studies with Japanese and U.S. rubella virus strains.

Japanese strains of rubella virus have been claimed not to be teratogenic, and tests on three Japanese strains showed that they induced high levels of interferon in human placental cell cultures obtained from conceptuses ranging from 13 to 24 weeks' gestational age, whereas two strains derived from the U.S.A. induced low levels. Both Japanese and U.S. strains induced similar but low levels in fetal lung cell cultures and leucocyte preparations. A representative Japanese strain and a U.S. strain were both interferon-sensitive. If indeed a strain can be shown to be non-teratogenic it could lead to an alternative, safer rubella vaccine.

Cells, Cultured↗

Further studies on the growth of rubella virus in human embryonic organ cultures: preliminary observations on interferon production in these cultures.

Organ cultures prepared from 15 different organs obtained from 43 fetuses were consistently found to support the growth of rubella virus, irrespective of the gestational age of the fetus or the strain of rubella virus inoculated. Although rubella virus replicated in fetal lenses, adult lenses did not support the growth of rubella virus. Organs obtained from four fetuses between 8 and 17 weeks gestational age produced similar titres of an inhibitor which had the characteristics of interferon. The use of Trowell T8 medium and incubation in a mixture of 5% CO(2) in oxygen provided the most suitable conditions for the maintenance of most organ cultures. Under these circumstances it was possible to obtain adequate histological preparations from these organs, but light microscopy studies revealed no significant differences in sections of rubella inoculated and control organ cultures.

Brain↗

Serological assessment of rubella during pregnancy.

In 45 patients with rubella-like illnesses during pregnancy serological tests showed that the clinical diagnosis had been accurate in only 20. Since only 16 of these patients had presented for laboratory investigations within a week of the onset of symptoms, the value of haemagglutination-inhibition tests was considerably reduced; the diagnosis in these cases was confirmed by complement-fixation and rubella-specific IgM tests.Of 172 patients exposed to a rubella-like illness, only 17 were seronegative; 105 sought advice within two weeks of exposure, and therefore the haemagglutination-inhibition antibody tests were useful in determining immunity. Since the clinical diagnosis of rubella was proved incorrect in a number of cases, these pregnancies were saved. Hence both doctors and patients should report both exposure to and rubella-like illnesses as early as possible, so that laboratory investigations may be carried out without delay.

Abortion, Therapeutic↗

Rubella virus infections during pregnancy, Toronto, 1963-66.

Among 670 pregnant women who attended the antenatal clinics of two Toronto city hospitals and one suburban hospital between May 1963 and January 1966, 29 of 550 patients apparently acquired rubella neutralizing antibodies, including 12 whose initial sera were collected during the first trimester. None developed overt rubella. Although rubella antibodies were detected in 61 to 79% of mothers aged 20 years or more, and antibody conversions were detected in 4 to 10% of mothers in each five-year age group between 16 and 39 years, tho rubella syndrome did not appear among any of their offspring. Five of seven other infants, aged 4 to 22 weeks, with the rubella syndrome excreted rubella virus. Rubella neutralizing antibodies were detected in all seven of these infants; these persisted at least 56 weeks in one subject. One mother who received gamma globulin during the first trimester was delivered of an infant who showed signs of the rubella syndrome.

Adolescent↗

Viral infections of Toronto children during 1965: II. Measles encephalitis and other complications.

Among 16 cases of measles encephalitis observed in Toronto during 1964 and 1965, including six who were stuporous or comatose on admission and five who presented with convulsions, measles virus was isolated from CSF of one patient, rising titres of measles antihemagglutinin were detected in another patient, and 14 showed high antibody titres in sera collected as early as two to five days after onset of the measles rash. Increasing levels of measles antibody were detected in paired sera from three of seven patients with uncomplicated measles, and elevated antihemagglutinin titres were found in 16 cases of measles without neural involvement. Measles virus was isolated from lung tissue of a fatal case of giant cell pneumonia. Administration of pooled human gamma globulin to one leukemic patient, and of leukocytes from a convalescent donor to another leukemic child, may have assisted their recovery from measles.

Child↗