Deoxycytidine and radiation response: exceedingly high deoxycytidine aminohydrolase activity in human liver.

The activity of deoxycytidine aminohydrolase in the liver of various species including man was investigated. An enormously high activity was found in human liver. This fact explains the extraordinarily low level of deoxycytidine in human urine in comparison with that of other tested species. The suitability of deoxycitidinuria as a biochemical indicator of postirradiation damage in man remains, therefore, an open question.

[Clinical changes in whole-body irradiated cattle]. / Klinické zmêny u celotêlovê ozáreneho skotu

Clinical manifestations of an acute radiation sickness in groups of heifers of the age of seven to nine months, irradiated with a multipoint spatial 60Co source with the doses of 3.7, 2.0, and 1.2 J per kg-1 (450, 250, and 150 R) were studied. Those doses evoked different stages of clinical manifestations, which made it possible to differentiate severe, medium, and light forms of the radiation sickness. The different forms vary with the intensity of the clinical manifestations, with the length of survival, and, above all, with the length of latent stage. The severe form had mostly a lethal course with the exit between the 15th to 19th day, in the case of the medium form the length of survival increases to the 25th to 28th day, and the light form showed no significant clinical manifestations.

[Pathomorphological findings in irradiated cattle]. / Patomorfologické nálezy u ozáreného skotu

There is a description of the finding in whole-body irradiated young cattle exposed to 60Co in the doses of 3.7 and 2.0 J kg-1 (370 and 200 rad). The principal picture is a hemorrhagic diathesis localized above all in the permanently mechanically active organs and parts of the skeletal muscles. The degree of the regeneration of lymphoid tissue was dependent on the length of survival and on the amount of absorbed dose.

[Biochemical indicator of post-irradiation injury in cattle]. / Biochemicky indikãtor postiradiacniho poskozeni u skotu

A biochemical indicator of post-irradiation injury, recording the increased secretion of metabolites of nucleic acids in the urine of whole-body irradiated cattle in the first 6-12 hours after exposure was worked out. This test consists in the determination of deoxycytidine substances by means of the test with thiobarbituric acid after a previous isolation by means of ion exchange chromatography. A significant increase of the excretion of deoxycytidine substances which was proportionate to the dose of irradiation and made it possible to divide the irradiated cattle into animals showing light, medium, and severe forms of the irradiation sickness was found.

[Dynamics of early changes in the white component of the peripheral blood of whole-body irradiated cattle]. / Dynamika casnych zmên v bilí slozce periferní krve celotlové ozãreneho skotu

Some new findings regarded the dynamics of the changes in the white component of peripheral blood, particularly at early intervals in the case of three clinically differing doses of ionizing radiation were obtained. At the highest dose early nonspecific leucocytosis was recorded only six hours after the exposure. Significant neutrophili occurred in the case of all three doses beginning from the sixth hour. With the highest dose it had the shortest duration and highest values, and at the smallest dose the opposite was the case. In the case of the highest dose leucopenia sets in after 24 hours, and in the case of the other doses not until after 36 hours. Lymphopenia appears already after 6 hours, the consequences according to the doses, however, manifest themselves only after 12 hours. In all three groups leucopenia and lymphopenia have a constant character. It was confirmed that the changes in the white blood component were the most typical response to the exposure to ionizing radiation, and orientation and special criteria have been found for the estimation of the consequences of the forms of irradiation on the basis of numerical changes of leucocytes, lymphocytes, and neutrophilic granulocytes within 72 hours after the exposure.