Effect of autologous serum on the state of the interphase chromatin of the lymphocytes in Down's syndrome

A luminescence microscopic study of a short-term culture of human lymphocytes with the aid of acridine orange showed that the modified state of the interphase chromatin in patients with Down's syndrome can be partly restored to normal by incubating the patient's lymphocytes with healthy human serum. These results suggest that the component inhibiting chromatin activation is absent or qualitatively changed in the serum of patients with Down's syndrome. The incomplete restoration of the ability of the chromatin to fix the dye points to irreversible changes in the structure of the chromatin itself, in the direction of condensation.Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 10, pp. 97–99, October, 1974.     

Changes in lymphocyte chromatin in Down's syndrome revealed by the thermal denaturation method

A luminescence-microscopic study using acridine orange with a short-term culture of human cells showed that DNA melting profiles of the chromatin of intact lymphocytes of healthy donors are curves with maxima (F 530) in the temperature regions of 45, 65, 78, 85, 88, and 92°C (P<0.01). The melting profiles of lymphocytes of patients with Down's syndrome are curves with maxima in the temperature regions of 65, 85, 88, and 92°C (P<0.01). The absence of a decrease in the intensity of fluorescence between 78 and 85°C is evidently due to the greater degree of condensation of certain regions of the chromatin complex of the trisomic cells. The possible mechanisms of the structural changes in the interphase chromatin, of human lymphocytes under the influence of temperature are discussed.Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 672–674, June, 1976.     

Analysis of the modified structural state of the chromatin in Down's syndrome

The relationship between optical density (=260 nm) of the nuclear chromatin of normal human lymphocytes and lymphocytes from patients with Down's syndrome and temperature was studied. Lymphocyte nuclei from healthy donors were characterized by the presence of a low-temperature (about 70°C) absorption maximum which was absent in nuclei of lymphocytes from patients with Down's syndrome. Analysis of this relationship for particular regions of the nucleus showed the existence of at least two types of regions—those with a low-temperature absorption maximum and those without. For Down's syndrome, the content of regions of the latter type in the lymphocyte nuclei was found to be greater than normal.Laboratory of Molecular Biology, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 4, pp. 471–473, April, 1978.     

Effect of vitamin E on chromosomal aberrations in lymphocytes from patients with Down's syndrome

A possible protective effect of vitamin E (DL-alpha-tocopherol) on chromosomal damage was evaluated in lymphocytes from patients with Down's syndrome (DS) and from controls. This included the analysis of the basal and G2 chromosomal aberration frequencies in lymphocytes cultured with and without 100 microM vitamin E. The chromosomal damage in G2 was determined by scoring the number of chromosomal aberrations in lymphocyte cultures treated with 5 mM caffeine, 2 h before harvesting. Vitamin E treatment decreased the basal and G2 chromosomal aberrations both in control and DS lymphocytes. In DS cells, this protective effect, expressed as a decrease in the chromosomal damage, was greater (50%) than in controls (30%). These results suggest that the increment in basal and G2 aberrations yield in DS lymphocytes may be related to the increase in oxidative damage reported in these patients.     

Absence of a radiation-induced adaptive response of lymphocytes in Down's syndrome

N. I. Pirogov Second Moscow Medical Institute. Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. P. Bochkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 9, pp. 290–292, September, 1991.     

Structure of interphase chromatin in patients with Down's syndrome and their mothers

Features of an altered structure of the interphase chromatin characteristic of their affected children were found in mothers of children with Down's syndrome by luminescence microscopy of short-term cultures of lymphocytes stained with acridine orange. Abnormalities similar to the changes found in their mothers also were found in girl sibs. The results suggest that there is a certain population of women whose genotype is such that it favors the appearance of this type of chromosome pathology. Since the altered structural organization of the chromatin was found only in the mothers and girl sibs, it seems likely that these features of the genotype are inheritable and are linked with genes (or particular regions of chromatin) limited by sex.Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 353–355, March, 1977.     

Early impairment of synaptic plasticity in patients with Down's syndrome

We investigated synaptic plasticity in persons with Down’ syndrome (DS) and control subjects used paired associative stimulation (PAS) protocol, a paradigm capable of producing long-term potentiation (LTP)-like changes in the sensorimotor system. After PAS, patients showed less LTP-like plasticity compared to control subjects. Abnormal motor cortex synaptic plasticity may play a role in the development of motor signs in DS.     

Regional differences in the compaction of chromatin in human G0/G1 interphase nuclei

The large-scale structure of chromatin corresponding to G- and R-bands in human G₀/G₁ interphase nuclei was compared. Fluorescence in situ hybridization (FISH) was used to measure the interphase distance between 42 pairs of probes separated by 0.1–1.5Mbp. The probe pairs were derived from 21q22.2 and Xp21.3, G-band positive regions, and from 4p16.3, 6p21.3, and Xq28, R-band positive regions. Distributions of measured interphase distances in all regions approximated a Rayleigh distribution, suggesting that the chromatin follows a random-walk path over this range. A linear correlation of mean-square interphase distance and genomic separation, also indicative of random-walk folding, was observed in all regions. The slope of the correlation observed using probes from G-band regions was systematically lower than that from R-band regions. The difference in the slope between Xp21.3 and Xq28 was particularly striking and was observed in normal fibroblast cells, fixed alternatively with methanol and acetic acid or paraformaldehyde, and HeLa cells. These results demonstrate regional differences in large-scale chromosome structure during interphase, with the more openly configured chromatin corresponding to R-bands.This revised version was published online in November 2005 with corrections to the Cover Date.     

Content of T and B lymphocytes in healthy human peripheral blood

It was shown by the rosette-formation method that the number of T and B lymphocytes in human blood varies with the time of day and season of the year. The number of T cells reaches a maximum in the morning and the number of B cells in the evening. The relative percentage of B cells is higher in the fall than in winter.Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 872–874, July, 1976.     

Analysis of changes in the nuclear chromatin of peripheral blood lymphocytes in down's syndrome

Bulletin of Experimental Biology and Medicine -     

The levels of superoxide dismutase,catalase, and carbonic anhydrase in erythrocytes of patients with Down's syndrome

Summary The levels of cytoplasmic superoxide dismutase (SOD₁), catalase (CAT'ase), and carbonic anhydrase isoenzymes (CA-B and CA-C) were determined in the erythrocytes from 11 male patients with Down's syndrome. The levels of SOD₁ and CAT'ase, as well as CA-B showed significant increases compared with those in normal controls, whereas the CA-C level did not change substantially. In addition, a positive correlation was noted between the levels of SOD₁ and of CAT'ase (r=0.764).Supported in part by a grant from the Japanese Ministry of Education     

唐氏综合征高危孕妇血浆游离胎儿DNA的检测

目的探讨实时荧光定量PCR(RQ-PCR)检测孕妇血浆游离胎儿DNA;在筛查唐氏综合征高危孕妇中的应用。方法采用RQ-PCR检测22例唐氏综合征高危孕妇及20例低危孕妇血浆中GA;PDH及SRY水平,2-△△Ct法分析两组间的差异。结果 22例孕男胎均检出SRY基因,20例孕女胎中出现2例假阳性,高危组游离胎儿DNA;水平明显高于低危组(P=0.006,<0.05),比值为2.79。结论孕妇血浆游离胎儿DNA;的定量检测在唐氏综合征筛查中有重要价值。