Low mitotic activity of peripheral lymphocytes during the first two years of life

The in vitro response of peripheral lymphocytes to phytohaemagglutinin was investigated in children less than 2 years old, in children 8-13 years old, and in adults. The mean mitotic index in the very young children was about one-half that of older children or adults. Mitotic counts tended to increase with increasing age during the first two years of life. It is suggested that the weaker lymphocytic response to phytohaemagglutinin may be associated with relative incompetence of the cellular immune mechanism in early life

AUTOSOMAL FOLATE SENSITIVE FRAGILE SITES IN NORMAL AND MENTALLY-RETARDED INDIVIDUALS IN GREECE

The frequencies of autosomal folate sensitive fragile sites were compared in populations of mentally retarded fra(X) negative (N = 220) and normal children (N = 76) in Greece. In addition, the frequency of autosomal fragile sites was studied in 20 known fra(X) children in order to test if the fra(X) syndrome is associated with general chromosome instability. The frequencies of both common and rare autosomal fragile sites did not differ significantly between the mentally retarded and the normal children, although the rate of expression was considerably higher in the retarded group. Autosomal fragile sites were not increased in the fra(X) patients. Fra(3)(p14) was by far the most frequent one in all groups. The frequency of fra(6)(q26) was found to be considerably higher among the mentally retarded children, this difference being almost statistically significant. Further cytogenetic studies of normal and retarded individuals are required in order to elucidate this point further

Skin hypersensitivity and in vitro lymphocytic reactivity to tuberculin in childhood

The mitogenic effect of old tuberculin was studied in cultures of peripheral lymphocytes from 113 children with a negative delayed dermal hypersensitivity reaction to tuberculin and from 30 children with a positive dermal reaction. A significant number of cells in mitosis was seen in (a) 23 of 100 randomly chosen children and 11 of 13 BCG vaccinated children in the absence of delayed dermal hypersensitivity to tuberculin, (b) 18 of 20 children with a positive dermal reaction but no history of active tuberculosis, of healing tuberculosis, or of a history BCG vaccination, and (c) 4 of 10 children with active tuberculosis. It is suggested that the in vitro lymphocytic response to tuberculin may be useful in detecting sensitization not expressed by delayed skin hypersensitivity. © 1968 The C. V. Mosby Company

PLASMA AND BLOOD VOLUMES IN SEVERELY MALNOURISHED INFANTS

ABSTRACT. Zoumboulakis, D., Anagnostakis, D., Kiossoglou, K., Agathopoulos, A. and Tsenghi, C. (Department of Paediatrics, Athens University, Athens, Greece). Plasma and blood volumes in severely malnourished infants. Acta Wediatr Scand, 63: 507, 1974. —This study was carried out in order to gain some insight into the plasma and blood volume fluctuations in severely malnourished infants. By means of an isotope dilution technique and microhaematocrit measurements, plasma and blood volumes were studied in 18 severely malnourished infants, aged 5 to 20 months and in 5 healthy controls, aged 3 to 20 months. Both plasma and blood volumes were found to be considerably higher in the malnourished infants (79.22±14.5 ml/kg and 119±17.8 ml/kg, respectively) than those in the controls (51.6±6.8 and 76.4±7.7 mg/kg, respectively. The differences in both instances were statistically highly significant. When, however, plasma and blood volumes were expressed not by means of the actual body weight but per kg of the expected body weight for height, there were no significant differences between malnourished (50.6±9.4 ml/kg and 76.1±12.4 ml/kg respectively), and healthy infants (51.6±6.8 ml/kg and 76.4±7.7 ml/kg respectively). These results suggest that the absolute intravascular fluid volume, which plays an important role in maintaining normal homeostasis, is unchanged in malnutrition. Copyright © 1974, Wiley Blackwell. All rights reserve