Biomedical subjects
Publications and source records attributed to A E Baranov.
In spite of intensive antimicrobial prophylaxis and therapy, most patients with acute radiation sickness I-IV severity grade (dose of 0.1-13.7 Gy) developed infections caused by bacteria, fungi and viruses. Frequency and intensity of those infections were proportional to the radiation dose and severity grade of radiation sickness.
The article deals with consequences seen in track driver after prolonged exposure to radiation caused by "lost" gamma-source (cesium-137) that long remained in receptacle of the vehicle's left door. Radiation dose averaged 8 Gy. The authors presented clinical manifestations, changes in peripheral blood and bone marrow, cytogenetic data by progression of radiation hemopoiesis hypoplasy to myelodysplastic syndrome and to acute leukaemia.
This paper describes the sequence of events, medical aspects and dose estimations for two radiographers and their driver who were seriously exposed to an iridium-192 industrial radiography source that became detached from its wind-out cable. The men came to medical attention about 1 month later by which time all three were severely leucopenic and one had skin burns on both hands. Doses were estimated by (i) physics calculations combined with their accounts of the event. (ii) the levels of depression of their blood neutrophils, (iii) electron spin resonance on tooth enamel and (iv) blood lymphocyte chromosomal analyses by the conventional dicentric and the fluorescence in situ hybridisation methods. Intercomparison of these methods for estimating doses showed a good level of agreement. In brief, the averaged whole body dose for the most seriously exposed man was about 2.5-3.0 Gy and for the others it was 1.0-2.0 Gy.
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Two World Health Organization Radiation Medical Emergency Preparedness and Assistance Network centers have constructed a standardized central repository of acute radiation syndrome case histories. The case histories are stored on a database server. Radiation protection centers can remotely access the database by user-friendly client software over the Internet. Physicians can use the medical information system to retrieve similar case histories for decision support, to improve their medical knowledge by inspecting real case histories, and for research on the acute radiation syndrome. The system architecture is presented and it is shown in detail how the information system can be employed to deliver medical decision support. Dialogue-response times over narrow-bandwidth Internet connections are better than when using conventional World-Wide-Web technology. However, the latter does not require the installation of client software other than a browser. A Java applet as client could combine the advantages of the two approaches.
The World Health Organisation (WHO) Radiation Emergency Medical Preparedness (REMPAN) centres have built up the International Computer Database for Radiation Accident Case Histories (ICDREC) to document the medical treatment of acute radiation syndrome (ARS) patients. Images play an increasing role as complementary information beside text and numerical data in medicine. In particular, retrieval and display of digitised skin photographs serve to improve patient care, medical education and scientific analysis concerning the cutaneous radiation syndrome (CRS). The ICDREC has been built up as a client/server system. Particular focus has been set on using commercial off-the-shelf software components. All the medical data including the multimedia data are stored in a relational database system. The database can be accessed by inexpensive personal computers in the physician's workplace. Retrieval of one photograph via local area network (LAN) requires approximately 3 s. Authorised institutions can access the database via the Internet. The current state of the ICDREC multimedia component is illustrated with the skin lesion treatment of a Chernobyl patient. An example is given on how the workflow in a dermatology department is supported by the ICDREC.
The World Health Organisation (WHO) Radiation Emergency Medical Preparedness (REMPAN) centres have built up the International Computer Database for Radiation Accident Case Histories (ICDREC) to document the treatment of acute radiation syndrome (ARS) patients. Radiation induced skin lesions may cause severe late effects in radiation accident patients. Dermatological multimedia documentation is included into the ICDREC. In particular, retrieval and display of digitised skin photographs and medical reports serves to improve patient care, medical education, and scientific analysis concerning the cutaneous radiation syndrome (CRS). The database has been built up as a client/server system. A particular focus has been set on using commercial off-the-shelf software components. The medical data including the multimedia data are stored in a relational database system. The database can be accessed by inexpensive personal computers in the dermatologist's workplace. Authorised institutions can access the database via the Internet. Retrieval of one skin photograph via local area network (LAN) requires approximately 3 seconds. The current state of the application is illustrated with the skin lesion treatment of a Chernobyl patient. An example is given on how to access the ICDREC from a dermatologist's desktop personal computer. The discussion focuses on the advantages of storing the textual and pictorial data in one central database to be accessed from different care centres and how the results can be generalised for medical multimedia information systems.
The management of acute radiation syndrome in persons inadvertently exposed to total-body irradiation greatly benefits from the experience gained in previous clinical management situations. Within the framework of exposure to high doses, one of the most critical issues is the question of whether hematopoietic stem cell transplantation is indicated. A valid answer can be given with appropriate accuracy based on a thorough analysis and evaluation of all accessible case histories. Based on the clinical evaluation of patients severely affected with acute radiation syndrome, the following recommendations may be issued. There is limited indication for stem cell transplantation when there is accompanying severe radiation damage to organ systems other than the hematopoietic system. The optimum duration of pancytopenia can be estimated using the biomathematical model introduced in this article.
Quantification of the biologically relevant dose is required for the establishment of cause-and-effect between radiation detriment or burden and important biological outcomes. Most epidemiological studies of unanticipated radiation exposure fail to establish cause and effect because of an inability to construct a valid quantification of dose for the exposed population. No one biodosimetric technique (biophysical or biological) meets all the requirements of an ideal dosimeter and thus qualify as a "gold standard." This report combines new results with previously published data in order to establish a collective biodosimetry as a dosimetric "gold standard" for the victims of three radiation accidents. Combining new and previously published data is necessary as execution and planning of a comprehensive dosimetry is rarely done at the initial stages of a radiation accident. The first subject was a fireman during the initial moments of the Chernobyl nuclear accident; the second was the victim of an unspecified occupational accident; and the third was exposed to a 60Co sterilization source. There was generally good agreement among the various biodosimetric techniques used for the three accident victims.
Two cases of myeloid leukemias (acute [AML M2] and chronic [CMC]), blastic crisis, with identical t(2;3)(p13;q26) are described. These cases had some peculiarities: no significant decrease of blood thrombocyte count in the AML patient and high increase of blood thrombocyte count during blastic phase in the CML patient; dysplastic megakaryocytes in bone marrow and unfavorable course of the disease; and short remission (3 months) in AML and short chronic phase (8 months) in CML. Clinical and morphologic findings in patients with t(2;3)(p13;q26) resembled those in cases with 3q21q26 syndrome or with other chromosome rearrangements involving 3q21 or 3q26.
Five men received high-dose, uneven, whole-body gamma-irradiation by accidental exposure to an unshielded 137Cs source. Analysis of the faeces 9-12 days post-irradiation showed low numbers of anaerobes and high counts of enterobacteria and staphylococci in four of the patients and total viable counts of < 10(3)/g in one. All five were treated with systemic ampicillin and gentamicin and oral nystatin commencing 4-7 days after irradiation. Three of the patients were also treated orally with a suspension of an antibiotic-resistant strain of Bifidobacterium longum for 30 days commencing 10-12 days post-irradiation. At 3 weeks post-irradiation, B. longum had appeared in their faecal flora and total anaerobe counts exceeded those of facultative and obligate aerobes. At 4 weeks and 5-7 weeks post-irradiation, this normalisation of the faecal flora continued. In contrast, in the two patients who received a placebo the faecal flora was dominated by enterobacteria (Klebsiella, Enterobacter and Serratia spp.) showing multiple antibiotic resistance 3 weeks post-irradiation. These potential opportunist pathogens were not isolated from the B. longum-treated group. Only one patient in the control group survived beyond 3 weeks; he continued to show high faecal counts of enterobacteria and staphylococci and low counts of obligate anaerobes. 'Probiotic' treatment with this antibiotic-resistant strain of B. longum may be of benefit in the treatment of radiation sickness, aiding normalisation of the faecal flora and inhibiting colonisation and overgrowth with opportunist pathogens.
Using the Chernobyl accident as an example, an attempt is made to consider the possibility of using the biological markers of exposure and effects of exposure to ionizing radiation in relation to biology dosimetry, and to predict early and late nonstochastic and stochastic radiation consequences. The biological dosimetry was based on the three markers: chromosome aberrations of peripheral blood lymphocytes, dynamics of blood cell (lymphocytes, neutrophils) counts and electron spin resonance (ESR) of tooth enamel. The first two methods can be applied in a short period of time (days or weeks) after exposure and only after high doses (> 0.5-1 Gy) of acute total body irradiation (TBI). The ESR tooth enamel method possesses dosimetric value at all conditions of uniform gamma TBI (acute, prolonged, chronic and high as well as low level of doses) and at any time after exposure. The low limit of sensitivity of the ESR test is about 0.1 Gy. The use of biological markers of effects of radiation exposure as early diagnostic signs was limited to clinical significant disorders of hemopoietic, immune systems and skin in conditions of acute high-dose irradiation. In cases of acute or prolonged irradiation in low doses, many changes on the cellular as well as organism level were discovered. However, there were not enough data on radiation specificity or dose dependence of these changes. Hence they cannot be considered as the indicators of clinically significant early and late nonstochastic effects. The role of biological markers of stochastic effects in clinical practice is discussed herein.
Considerable data suggest that very high doses of acute total body radiation destroy most hematopoietic stem cells and that recovery is possible only after a bone marrow transplant. We review data from a radiation accident victim exposed to about 10-Gy or more acute total body radiation. Total dose and uniformity of distribution were confirmed by physical measurements (paramagnetic resonance), computer simulation, and biologic dosimetry (granulocyte kinetics and cytogenetic abnormalities). Treatment consisted of supportive measures, transfusions, and hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor and interleukin-3). Hematopoietic recovery occurred slowly. Granulocytes were detectable throughout the postexposure period, exceeding 0.5 x 10(9)/L by day 37. There was slower and incomplete recovery of red blood cells and platelets. Increases in blood cell production were paralleled by morphologic changes in bone marrow biopsies. Gastrointestinal toxicity was moderate. Death from a probable radiation pneumonitis infection occurred on day 130. These data indicate the possibility of hematopoietic recovery after approximately 10 Gy or more acute total body radiation without a transplant. They also suggest that lung rather than gastrointestinal toxicity may be dose-limiting under these circumstances.
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The previous experience gained with the treatment of acute radiation sickness supported during the treatment of the victims to the disaster at the Chernobyl NPP has shown the multimodality treatment to be indispensable for the bone marrow syndrome, particularly in terms of correcting postradiation thrombocytopenia and counteracting bleeding sickness. The use of the whole blood was found to be inadvisable because of the low efficacy, with the risk of transfusion complications being fairly high. Adequate replacement therapy with donor's platelets is capable of a complete modifying of the hemorrhagic syndrome.
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