Cytogenetic Observations in Cultured Lymphocytes from Patients with Down's Syndrome and Measles

Abstract

ExtractChromosomes were studied in 72-hr lymphocyte cultures from 11 patients with Down's syndrome and 8 hematologically and karyotypically normal control subjects before and after measles infection.The number of breaks per cell in patients with Down's syndrome after measles infection was 0.191 d= 0.073, which was significantly greater than the number of breaks before infection (0.040 ± 0.020) and which was also significantly greater than the number of breaks in control children with measles (0.046 ± 0.024). Therefore, chromosomes of cells of patients with Down's syndrome were significantly more sensitive to measles infection than those of control subjects.Statistical assessments were made on randomness and nonrandomness of breakage distribution in chromosome groups and arms. Excess breaks were found to occur in the long arms of B and D group chromosomes. Speculation

Sister Chromatid Exchanges and the Cell Cycle in Peripheral Blood Lymphocytes of Down Syndrome

“…This suggests that they are a related picture, though not all, to pathogenesis of leukemia or malignancy in DS (Higurashi et al 1973;Hayakawa et al 1968;Burgio et al 1974).…”

“…It has been shown that the cell physiology of the patients with Down syndrome differs from that of normal subjects (Kaback and Bernstein 1970;Schneider and Epstein 1972;Segel and McCoy 1974), and that cultured somatic cells derived from the patients with DS are liable and instable for some physical and chemical factors, such as X-rays, chemical agents, viral infections, and so on (Sasaki and Tonomura 1969 ;Higurashi et al 1973 ;Countryman et al 1977) . This suggests that they are a related picture, though not all, to pathogenesis of leukemia or malignancy in DS (Higurashi et al 1973;Hayakawa et al 1968;Burgio et al 1974).…”

“…Evidence has been provided that somatic cell chromosomes of DS are more susceptible than the normal chromosomes to biological, chemical, and physical factors (Sasaki and Tonomura 1969 ;Higurashi et al 1973 ;Countryman et al 1977) . However, the evidence so far presented has not been consistent on susceptibility and the cell cycle-time of lymphocytes in DS (Hayakawa et al 1968;Sasaki and Obara 1969;Agarwal et al 1970;Fowler and Hollingsworth 1973).…”

Cell cycle analysis and properties of two sub-populations in PHA responding lymphocytes

“…For instance, the hyperblastic responses of trisomic cells have been shown in mixed lymphocyte cultures of normal persons and patients with Down's syndrome and in cultures stimulated by low concentrations of phytohemagglutinin (PHA) (Hayakawa et al, 1968;Matte et al, 1969). The chromosomes of patients with this syndrome are more susceptible to damages by ionizing radiations (Sasaki and Tonomura, 1969), certain chemicals (O'Brien et al, 1971 ;Schuler et al, 1972) and viruses (Higurashi et al, 1973(Higurashi et al, , 1976.…”

Safety of measles vaccination to the patients with down syndrome on the chromosomal level.

“…The ages of donors differed a little between the 2 groups because of the difficulty of sampling. Blood sampling was done just before vaccination and from 2 to 9 weeks after vaccination, in order to compare the results with those of wild infection (Higurashi et al 1973).Cell culture: Lymphocyte cultures were set up with heparinized blood in RPMI-1640 (GIBCO) with 10% of FCS (GIBCO), 2 pg/ml of phytohemagglutinin A-M (GIBCO) and 10 pg/ml of 5-Bromodeoxyuridine (SIGMA) in final concentrations.They were incubated for 72 hrs at 37°C in 5 % C O2 atmosphere in the dark. Two hours prior to harvest, 0.2 pg/ml of colcemid (GIBCO) in final concentration was added.…”