Chromosomal breaks in human leucocyte cultures induced by an agent in the plasma of infectious hepatitis patients

Oxidative imbalance in HIV infected patients

We present an outline of the complex interplay of oxidants and antioxidants in infectious diseases in general, and in particular with reference to the HIV infection, and subsequent opportunistic infections. Viral and opportunistic infections may directly or indirectly cause an imbalance in prooxidant/antioxidant mechanisms and result in generation of increased steady state concentrations of reactive oxidants. In HIV patients a prooxidant state could lead to a self-perpetuation of infection via stimulated expression of genes carrying the virus genome, and subsequently to immunosuppression, and promotion of initiated cells to neoplastic growth.

Constitutive heterochromatin polymorphism and chromosome damage in viral hepatitis

The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCEs) were scored in relation to constitutive heterochromatin in 100 patients with viral hepatitis B, 100 patients with viral hepatitis A and 100 age- and sex-matched normal controls. 23.4%, 15% and 4% of the cells showed chromosomal aberrations in patients with hepatitis B, hepatitis A and normal controls respectively. Non-random involvement of chromosomal aberrations were also noted in chromosome 1 of patients with hepatitis B and A as compared to normal controls. The frequencies of SCEs (mean +/- S.D.) were found to be 10.40 +/- 2.83 in hepatitis B and 8.70 +/- 2.34 in hepatitis A. These values were significantly higher than the SCE frequency (mean +/- S.D.) of 5.88 +/- 2.25 observed in normal controls (P less than 0.001). The intra-chromosomal distribution of SCEs revealed a relatively increased incidence of SCEs in chromosome 1 of patients with hepatitis B and A as compared to normal controls. Analysis of constitutive heterochromatin polymorphism showed chromosome 1 qh+ to be the most frequent variant in patients with hepatitis B and A as compared to normal controls. The increased involvement of C-band variant 1 qh+ in patients with hepatitis B and A as compared to normal controls may indicate that extra heterochromatin offers additional sites for viral integration.

Chromosome breakage and sister chromatid exchange frequencies in scleroderma

Peripheral lymphocytes from 3 scleroderma patients with systemic disease and from 3 normal controls were examined for frequencies of chromosomal aberration and sister chromatid exchange (SCE). Significant increases in the levels of chromosomal anomaly and SCE were found for all 3 patients. These results are discussed in terms of the diagnostic potential of SCE in scleroderma and the possible etiologic role of cytogenetic instability in this disease.

Azathioprine, a clastogen in human somatic cells? Analysis of chromosome damage and SCE in lymphocytes after exposure in vivo and in vitro

Chromosomal analyses in lymphocytes of 28 patients with multiple sclerosis were carried out before, during and after Azathioprine (Aza) therapy. Only a higher incidence of gaps was found in treated patients than in a group of healthy persons but not in comparison with untreated patients. Similarly, no significant clastogenic effect was observed in vitro after short-term and long-term treatment of unstimulated and stimulated lymphocytes with concentrations of 1--100 microgram Aza per ml. Treatment of cultures with 0.0001--4.0 microgram/ml did not yield increased SCE frequencies. The absence of any significant clastogenic effect of therapeutic doses of Aza on human somatic cells is deduced from an evaluation of previously published data and from the present results.

Investigation of the nature of Australia antigen. I: The absence of biological activity of Australia antigen in human blood leukocyte culture

Purified and concentrated preparations of Australia antigen had no stimulating effect on leukocytes of human subjects under study when tested either on DNA-polymerase activity, 3H-thymidine uptake or chromosomal alterations. Moreover, in patients with chronic hepatitis and cirrhosis of the liver no correlation between antigenemia and chromosome aberrations in blood leukocyte cultures could be detected. On the other hand, a serum obtained from a virus hepatitis patient with Australia antigen in the blood was found to stimulate leukocyte cultures from one patient with Down's syndrome and antigenemia, one mentally retarded patient and three normal donors. This stimulating agent is obviously not associated with Australia antigen.

Chromosome abnormalities in chronic active hepatitis

An investigation on human peripheral blood lymphocyte chromosomes in chronic active hepatitis was carried out. A higher percentage of chromatid and chromosome lesions was recorded in all patients studied as compared with control groups-normal individuals, healthy subjects who had suffered from acute viral hepatitis, patients with alcoholic liver disease, and patients with mechanical jaundice due to cancer. The possible origin of these abnormalities is discussed.

Chromosomal aberrations in infective hepatitis

Structural chromosomal aberrations, in the form of breaks, were found in a significantly higher proportion of bone marrow cells in patients with infective hepatitis than in controls. These anomalies were observed during the first and third weeks after the onset of jaundice but had subsided by the sixth week. Chromosomal aberrations did not appear to be related to the severity of infective hepatitis or to the sex or age of the patients.The distribution of chromosomal abnormalities did not appear to be random; they were observed predominantly in the A(2) and B(4-5) series. Since no abnormalities were detected in the G-group chromosomes, no evidence in support of a relationship between infective hepatitis and Down's syndrome was obtained. Numerical chromosomal aberrations were not observed, nor was any evidence obtained that mitotic activity of bone marrow cells is suppressed in patients with infective hepatitis.