Evaluation of psychoemotional status of rats after brain injury and systemic transplantation of mesenchymal stem cells.

We studied the effects of systemic transplantation of mesenchymal stem cells obtained after culturing of autologous bone marrow on psychophysiological status of Wistar rats after diffuse brain trauma. Two months after systemic injection of mesenchymal stem cells we observed a decrease in manifestations of emotional behavioral reactions (anxiety and excitability) and shortening of the time of realization of drinking behavior in a T-maze. A significant positive effect of systemic transfusion of mesenchymal stem cells on avoidance conditioning in a shuttle box was observed 3 months after brain injury.

Mortality among the Chernobyl emergency workers: estimation of radiation risks (preliminary analysis).

This paper presents results of the analysis of mortality among Chernobyl accident emergency workers who are resident in Russia. The analysis is based on information for the cohort of emergency workers (males) from six regions of Russia including 65,905 persons with documented external doses in the range 0.005-03 Sv. These data were gathered during the period 1991 to 1998 and cover a total of 426,304 follow-up person-y. In this period, 4,995 deaths occurred in the cohort under study. The mortality analysis was performed for four groups of causes of death (ICD-9 codes): (1) malignant neoplasms (140-239); (2) cardiovascular diseases (390-459); (3) injuries, poisoning and violent deaths, (800-999); and (4) the remainder (other than the above). The standardized mortality rate for groups 1, 3, and 4 is less than unity and varies from 0.6 to 0.9. For group 2 (death from cardiovascular diseases) the standardized mortality rate conforms with the control within 95% confidence intervals. The control was the mortality rate (males) for the corresponding ages in Russia in general and the internal control, the spontaneous mortality among emergency workers, derived from the equation of the observed and expected number of cases in the followed up cohort. Dose response of mortality was studied. Statistically significant radiation risks were obtained for mortality from malignant neoplasms (515 cases) and cardiovascular diseases (1,728 cases). The values of the excess relative risk per unit dose (ERR Sv(-1)) for malignant neoplasms and cardiovascular diseases are estimated as 2.11 (1.31, 2.92 95% CI) and 0.54 (0.18,0.91 95% CI) (for external control), 2.04 (0.45, 4.31 95% CI) and 0.79 (0.07, 1.64 95% CI) (for internal control), respectively. The risk of death from all noncancer causes is close to zero and not statistically significant.

Investigation of the impact of radiation dose on hormones, biologically active metabolites and immunoglobulins in Chernobyl accident recovery workers.

One hundred twenty-five Chernobyl accident recovery workers (liquidators) who were exposed to low-dose radiation were studied over a period of 4-6 years for changes in levels of hormones, arachidonic acid metabolites and cyclic nucleotides. Some significant changes were observed, especially in the levels of metabolites that are regulators of cell functions. In comparison to controls, there were increased levels of thyroxin, cortisol, thromboxane B2, and immunoglobulins G, A and M, and reduced levels of growth hormone, cyclic nucleotides and 6-keto-prostaglandin F1. The degree or presence of these metabolite imbalances did not correlate with the level of the radiation dose received. The only change found that did relate to the radiation dose received was a statistically significant increase in levels of biomarkers for oxidative stress, seen in workers who received higher doses.

The World Health Organization Network for Radiation Emergency Medical Preparedness and Assistance (REMPAN).

The World Health Organization (WHO) has established a system of collaborating centers known as the Radiation Emergency Medical Preparedness and Assistance Network (REMPAN) to promote radiation emergency medical preparedness, assistance, and advice to countries in cases of overexposure of populations from any source of radiation. This network consists of 13 specialized institutions located in 10 countries. Within the REMPAN there are three separate but linked activities. The first is aimed at strengthening radiation emergency medical preparedness and assistance to treat and monitor acutely exposed individuals. The second activity is directed toward improving public health advice to mitigate long-term effects of exposure to low and protracted doses that might accrue in populations living in the affected territories. This involves giving advice on protecting public health, e.g., iodine prophylaxis, psychosocial risks associated with countermeasures, and public information strategies. In addition, the REMPAN develops activities aimed at improving long-term follow-up studies and preparedness for epidemiologic investigations in territories contaminated by radionuclides from a nuclear accident. The WHO's response in a radiation emergency depends on the type of accident and its time phase. This includes a wide range of actions from studying the situation to providing medical and public health assistance through the network of collaborating centers and relevant institutions within the REMPAN. The process of creating a reliable international system for radiation emergency medical preparedness and assistance has not yet been completed. Deficiencies in this system are outlined in this paper to attract the attention of specialists in the field of radiation protection and potential donors of the WHO program.

Main scientific results of the WHO International Programme on the Health Effects of the Chernobyl Accident (IPHECA).

Scientific results obtained within the WHO International Programme on the Health Effects of the Chernobyl Accident (IPHECA) have confirmed the increase of thyroid cancer cases in children who were exposed to radiation due to the accident in 1986. In the zones under surveillance in Belarus, the Russian Federation and Ukraine, the general morbidity for leukaemia and related diseases did not undergo a significant change after the accident. Accident recovery workers ("liquidators") are an especially high-risk group and need further medical follow-up.

Health consequences of the Chernobyl accident : Results of the IPHECA pilot projects and related national programmes : Scientific report

There seems little doubt that the sharp increase in the incidence of childhood thyroid cancer was due to radioiodine emissions from the Chernobyl reactor. Wilth more work to reconstruct doses received, a better determination of the radiation dose-response relationship may be achievable. The future activities described in the report would provide for a sound continued development of the Programme. The Board is requested to provide guidance on the further implementation of the Programme, in particular as regards the need to increase the active participation of other Member States, their institutions and scientists in the Programme, mobilization of new extra-budgetary resources to adequately address current priorities and the overall strenghening of WHO's radiation protection activities (AU)

The World Health Organization and International Atomic Energy Agency second interlaboratory comparison study in 16 countries on quality performance of nuclear medicine imaging devices.

Sixteen European countries participated in this WHO-IAEA intercomparison for which transmission CAP (College of American Pathologists) thyroid and IAEA-WHO liver phantoms were used. A total of 257 laboratories submitted 428 image evaluation reports. Overall results showed differences in performance between the various countries but similarities in performance for two gamma camera subgroups defined by year of manufacture, before and after 1980. A unique review of current European liver imaging practice is presented in terms of technical parameters, imaging conditions and evaluation procedures, and quality control procedures. The WHO-IAEA intercomparison demonstrated the need to establish new, or to improve the existing, quality control programmes in certain countries. However, the large number of participating laboratories, 257 compared with 70 in the previous WHO study, (Volodin et al. 1985), shows that these international studies are serving a useful purpose in promoting quality control in nuclear medicine imaging laboratories.

World health organisation inter-laboratory comparison study in 12 countries on quality performance of nuclear medicine imaging devices.

Twelve countries participated in the WHO intercomparison for which transmission CAP (College of American Pathologists) brain and CAP liver phantoms and emission London liver phantoms were used. A total of 157 imaging devices were tested. Overall results from the phantoms revealed a wide range of targets detected. For the CAP-phantoms target detectability dropped below 50% for target sizes less than 9 mm and below 60% for target contrast less than 0.84:1. On average one false positive and six false negative results were reported using CAP-brain phantoms and one false positive and one false negative result using CAP-liver phantoms. For the London liver phantoms containing the tissue equivalent rubber abdominal simulation the target of 1 cm was never visualised. Two targets in this phantom (2 cm and 2.5 cm) were correctly identified in 34% of studies and one of these targets in 52% of studies. Equivocal and false positive results were reported in 42%. The WHO inter-comparison demonstrated the need to establish new, or to improve the existing, quality control programmes.