Acute childhood leukemias and exposure to magnetic fields generated by high voltage overhead power lines - a risk factor in Iran.

Many investigators have studied the effects of Extremely Low Frequency-Magnetic Fields generated by ordinary and domestic power lines, as a risk factor in acute leukaemias of children, but there are limited information available regarding very high voltage overhead power lines. Children in developing countries sometimes live very close to such structures and we have registered several patients with acute leukaemias appearing in clusters. In the present study we have analyzed 60 consecutively diagnosed patients with acute leukaemias, and 59 matched controls in a provincial capital city in North-Western Iran. After provision of consent, a detailed form was filled in, and a visit to the present (or previous) residential areas of both groups was arranged. The locations of the very high voltage power lines (123, 230, 400 kilo volts), were noted in each area, if present, and their distances from the houses under study were detected. The expected intensities of the Magnetic Fields (B) were calculated having the mean intensity of the electrical current and other line characteristics, by means of relevant equations. Fourteen patients in the case group (23.5%) were living near the high voltage power lines in distances < or = 500 meters. (Mean B = 0.6 microTeslas, microT). In the control group at the same distance, the figure was 2 children (3.3%) (Mean B = 0.35 microT). Statistically, the likelihood of leukaemia was increased considerably in this distance (Odds ratio (OR) = 8.67, 95% Confidence Interval (CI) = 1.74- 58.4, P value= 0.001). On the other hand 15 pts (25 %) in the leukaemia group were experiencing Magnetic fields above 0.45 microT in comparison to 5 in the control group ( 8.5% )(OR = 3.60, 95% CI = 1.11-12.39, P = 0.01). More children in developing countries like Iran live close to very high voltage lines, and they experience relatively more harmful effects from the Magnetic Fields, in comparison with children in developed countries. Residence near very high voltage overhead power lines, in distances < or = 500 meters, and Magnetic Fields >0.45 microT, should be considered a risk factor for the pathogenesis of acute leukaemias in children.

Acute sporadic hepatitis in Sudanese children.

Eighty consecutive cases of acute viral hepatitis and 80 controls selected from a public pediatric clinic were entered into a study of acute sporadic hepatitis in Khartoum, Sudan. Study subjects were 14 years of age or younger and were mainly from a low socioeconomic level. Non-A, non-B hepatitis was diagnosed by exclusion in 35 (43.8%) patients, hepatitis A in 27 (33.8%), acute hepatitis B in 8 (10.0%), possible Epstein-Barr virus (EBV) hepatitis in 1 patient; and dual hepatitis A and B infection in 1 patient. Eight acute cases were positive for HBsAg but negative for anti-HBc IgM and anti-HAV IgM. Delta hepatitis was not identified in any study subject. A household case of jaundice and acquaintance with an individual outside of the household with jaundice during the prior 6 months were associated with non-A, non-B hepatitis. There was no association between parenteral exposure and non-A, non-B hepatitis. These findings suggest that enterically transmitted non-A, non-B hepatitis may be a major cause of acute sporadic hepatitis in children in this area, as well as a cause of epidemic hepatitis.

Epidemiology of hepatitis B in the Gezira region of Sudan.

To determine the prevalence of and risk factors for hepatitis B infection in rural Sudan, 2 villages in the Gezira were surveyed. There were 851 subjects (age 1-89 years; mean age 24.6 years) of equal sex distribution, 408 from Khalawaat and 443 from Saleim. HBsAg was found in 18.7%, and seropositivity for any hepatitis marker (HBsAg, anti-HBs, or anti-HBc) was found in 63.9%. The prevalence of HBsAg was highest in subjects less than 5 years of age (32.3%). Seropositivity for any hepatitis marker increased from 48.4% in subjects less than 5 years to 88.5% in persons greater than or equal to 50 years of age. HBeAg was present in 70% of HBsAg-positive women of childbearing age. Residence in Khalawaat and parenteral therapy for malaria were found to be independent risk factors for HBsAg-positivity. Age, residence in Khalawaat, crowding, and having had a tattoo were predictive of seropositivity for any hepatitis marker. The reason for increased markers of hepatitis B in Khalawaat compared to Saleim was not apparent.

Non-A, non-B hepatitis in Omdurman, Sudan.

One-hundred nineteen patients (cases) at least 13 years of age with acute hepatitis were studied to determine the viral etiology of acute hepatitis in Omdurman, Sudan. Ninety-eight control subjects (controls) were also evaluated to determine the risk factors associated with the development of clinical disease. Acute hepatitis non-A, non-B was diagnosed in 88 cases (73.9%), hepatitis B in 15 cases (12.6%), delta infection in 15 (12.6%), and hepatitis A in just one patient (0.8%). A higher percentage of hepatitis B cases had received a parenteral injection for medical therapy during the previous 6 months than control subjects (26.7% vs 4.1%, p less than 0.05). The data in this study indicate that hepatitis non-a, non-B may be the major cause of acute hepatitis in adults in this area of Sudan. The suggested association of parenteral therapy with the transmission of hepatitis B could have important implications for the spread of other parenterally-transmitted diseases.

Concanavalin A induced suppression of lymphocyte proliferation in chronic liver disease. A study of suppressor and responder populations in autologous and allogeneic systems.

Abnormal T-cell regulation of lymphocyte proliferation may contribute towards tissue damaging mechanisms in chronic liver disease. We therefore studied Concanavalin A induced suppressor cell activity in T-T interaction in 47 patients with chronic liver disease, using both an autologous and an allogeneic system. In the autologous system, no differences were found between those with auto-immune chronic active hepatitis, HBsAg positive chronic active hepatitis, primary biliary cirrhosis, alcoholic liver disease and normal controls. However, several abnormalities were identified in allogeneic cultures with normal lymphocytes which allowed separate analysis of the influence of suppressor and responder cells from patients with chronic liver disease. An abnormality of the suppressor population was found in those with autoimmune chronic active hepatitis, primary biliary cirrhosis and alcoholic liver disease, while the responder population was abnormal in those with autoimmune or HBsAg positive CAH. Failure to demonstrate an abnormality in an autologous system may reflect a combined defect of suppressor and responder populations, and in this study the allogeneic system was a more sensitive index of abnormal cellular T-T interaction.