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Biomedical subjects

L Merkin

Publications and source records attributed to L Merkin.

9 recordsLinked to original sources

Clastogenic factors in the plasma of children exposed at Chernobyl.

Clastogenic factors (CFs), as they were described previously in accidentally or therapeutically irradiated persons, in A-bomb survivors and in liquidators of the Chernobyl nuclear power plant, were also detected in the plasma of Chernobyl-exposed children. A high percentage of plasma ultrafiltrates from 170 children, immigrated to Israel in 1990, exerted clastogenic effects in test cultures set up with blood from healthy donors. The differences were highly significant in comparison to children immigrated from 'clean' cities of the former Soviet Union or children born in Israel. The percentage of CF-positive children and the mean values of the adjusted clastogenic scores (ACS) were higher for those coming from Gomel and Mozyr, which are high exposure sites (IAEA measurements), compared to those coming from Kiev. There was no correlation between residual 137-Caesium body burden and presence of CFs. However, both measurements were not done at the same time (in 1990 and 1992-1994, respectively). Also no relationship could be revealed between enlargement of the thyroid gland and CF-positivity. CFs are not only observed after irradiation, but in a variety of chronic inflammatory diseases with autoimmune reactions. They were also described in the congenital breakage syndromes, which are hereditary diseases with the highest cancer incidence in humans. Whether the clastogenic effects continuously produced by circulating CFs represent a risk factor for malignant late effects deserves further study and follow-up. Since CF formation and CF action are mediated by superoxide radicals, prophylactic treatment with antioxidants may be suggested for Chernobyl-exposed children, whose plasma induces a strongly positive CF-test.

Autoimmune Diseases↗

Evaluation of the Radiation Exposures of Chernobyl "Liquidators": Exploratory Studies of a Sample of Immigrants to Israel.

Workers who were involved in the clean-up and recovery operation after the Chernobyl disaster ("liquidators") numbered about 800,000. Estimates of their exposures are highly relevant to evaluation of possible effects on their health. While some exposure measurements were made, they were also used for job assignments and terminations. The earliest and probably greatest exposure preceded adequate monitoring. By means of exploratory studies, the authors evaluated an exposure-estimating system proposed by a WHO consultation team in St. Petersburg. An index is derived based on recorded or reported 1) calendar time of initiating work, 2) location near or distant from the reactor, 3) duration of exposure, 4) type of work, 5) post-exposure symptoms, 6) blood count decreases, and 7) use of protective equipment. Data were obtained by interviews of liquidators who presented at a Beer Sheva clinic during evaluation of Cs-137 body burden. Of 75 liquidators, four had no data, one had only one item, six had two, 11 had three, 210 had four, 20 had five, 11 had six, and one had seven items. Only 19 had dose estimates. There was no trend in mean scores/item with increase in the number of items, indicating lack of information bias. Measured values, when available, were consistent with the scores. Clastogenic scores were determined for 26 of these subjects; the correlation with exposure indexes was 0.02, but for those with "positive" clastogenic tests (more than six abnormal divisions per 100), the correlation with the scores was 0.44. No such relationship was found for the persons with elevated Cs-137 tests. Glycophorin A antigen tests discriminated between liquidators and others, but, in this small study, did not correlate with the indexes.

Journal Article↗

Lessons learned from the study of immigrants to Israel from areas of Russia, Belarus, and Ukraine contaminated by the Chernobyl accident.

During the past 6 years, immigration to Israel of 700,000 persons from the former Soviet Union (FSU) included about 140,000 from radiocontaminated regions of Belarus, Ukraine, and Russia near Chernobyl. In Beer Sheva, a major center for immigrant absorption in Israel, a primary objective was to evaluate their health status and to refer them for care. 137Cs levels in 1228 men, women, and children were measured with a portable whole-body counter. Whole-body counts showed clear correlation with the degree of 137Cs ground contamination in previous regions of residence. The population could thus be sub-divided according to degree of exposure, based on previous regions of residence. The thyroid status of 300 local immigrant children was evaluated because of the increased risk of childhood thyroid cancer in the regions from which they came. This group was subdivided into comparative groups of children who came from less and more contaminated areas according to the International Atomic Energy Agency soil 137Cs contamination maps. Enlarged thyroids were found in about 40% of both groups. One 12-year-old girl from Gomel had a malignant papillary carcinoma. Thyroid-stimulating hormone levels, though within normal limits, were significantly greater (p < 0.02) for girls from high exposure regions. Liquidators showed significant increases in serum clastogenic factor and in the number of circulating glycophorin A-mutated red cells. In studies of over 700 people from both radiocontaminated and unaffected regions of the FSU, evidence for posttraumatic stress disorder was found more frequently in persons coming from the more contaminated areas.

Blood Pressure↗

Fatal intracerebral hemorrhage during dental treatment.

Although chronic arterial hypertension is the leading cause of intracranial hemorrhage, an abrupt rise in systemic arterial pressure in normotensive people may sometimes induce a hemorrhagic stroke. Dental treatment is rarely associated with such an event. We report here on two middle-aged women, apparently healthy, who suffered from a fatal intracerebral hemorrhage following a dental treatment. On admission, high levels of arterial hypertension were found. It seems that trigeminal manipulation during dental treatment as well as increased serum levels of induced epinephrine mainly by stress and pain, and the small amounts absorbed from the site of local anesthesia might produce abrupt elevation of blood pressure, subsequent increase in cerebral blood flow and severe, even fatal intracerebral hemorrhage. The addition of catecholamines to local anesthetics should be considered. We recommend the use of benzodiazepin as a premedication drug to reduce stress during dental treatment.

Anesthetics, Local↗

Health effects in a casual sample of immigrants to Israel from areas contaminated by the Chernobyl explosion.

We analyzed questionnaire and physician examination data for 1560 new immigrants from the former USSR divided into three groups by potential exposure to Chernobyl radiation. Two groups were chosen according to soil contamination by cesium-137 at former residences, as confirmed by our findings in a 137Cs body burden study. The third group consisted of "liquidators," persons who worked at the Chernobyl site after the disaster. Liquidators had greater self-reported incidences of symptoms commonly accepted as acute effects of radiation exposure, increases in prevalence of hypertension, and more health complaints. Excesses of bronchial asthma and health complaints were reported in children from the more exposed communities. Asthma prevalence in children potentially exposed in utero appears to be increased eightfold. Older adults from more exposed areas had more hypertension as assessed by history and measurements. These findings suggest the possible association of radiation exposure with several nonmalignant effects.

Adolescent↗

The aetiology of cancer: clues from spontaneous recovery.

There is indisputable scientific evidence of a spontaneous regression of cancer in several cases. The implication is that possibly there are other than the suspected aetiological factors involved in the problem of the origin, and even more important, in the cure of cancer.

Environmental Exposure↗

Dietary and clastogenic factors in children who immigrated to Israel from regions contaminated by the Chernobyl accident.

The authors evaluated the possible association between dietary history and plasma clastogenic factors in children who immigrated to Israel between 1989 and 1993 from regions contaminated by the Chernobyl accident. The authors compared questionnaire data about demographic variables, dietary histories before and after immigration occurred, and health status with clastogenic factor scores for 162 immigrants. Logistic regression analysis revealed a negative association between clastogenic factor scores and frequency of consumption of fresh vegetables and fruit among children < or = 7 yr of age during the postimmigration period. Intake of eggs and fish by boys who were < or = 7 yr of age prior to immigration was associated positively with clastogenic factor scores. Consumption of fresh vegetables and fruits afforded protection to the immune systems of children who were < or = 7 yr of age.

Adolescent↗