Effects of x-ray irradiation on circadian rhythm of the level of microsomal hemoproteins in the rat liver

The influence of X-irradiation of 12 Gy on the state of biorhythms of microsomal hemoproteins P-450 and b5 of the liver in male rats was studied. The content of these cytochromes was measured at 4, 10, 12, 15 and 21 hours in the course of the first and second days after X-irradiation and also on the fourth day (day of mass death of the irradiated rats). It has been found that disturbance of diurnal rhythms of these cytochromes begins already with third hour after X-irradiation and revealed in expressed depression of their acrophase. The diurnal rhythm of level of cytochrome P-450 is smoothed and takes the character of slowing down process, biorhythm of cytochrome b5 not being traced.     

Nasal cavity and paranasal sinuses of the roe-deer (Capreolus capreolus) (corrision-anatomical and x-ray studies)

By means of about fifty skulls of dominating female animals of all age groups the formation and topgraphy of the Cavum nasi and its Sinus paranasales at the roe-deer are investigated and described by pouring out the Sinus paranasales about their physiological entrances with Technovit 7143. Amongst numerous findings the main results are in the following: 1. the total absence of a Sinus frontalis, 2. the characteristic formation of the Sinus ethmoidales. The results are compared with the well-known findings at the sheep and goat and the differences are put out. Furthermore a critical discussion with the hitherto existing opinions about the pneumatisation of the skulls at the roe-deer is given.     

EPR studies of 5-bromouracil crystal after irradiation with X rays in the bromine K-edge region

Radicals induced in a single crystal of 5-bromouracil (BrUra) by synchrotron soft X rays in the bromine K-edge region (13.461-13.482 keV) were investigated using the X-band EPR method. The crystal was irradiated at three peak energies of the absorption spectrum at room temperature or at 80 K. A hydrogen abstraction radical derived from N1 of the pyrimidine ring was commonly observed for all of the energies used, though with some variation in quantity. Similar characteristics were also observed in the EPR signal for the off-K-edge low-energy (13.42 keV) and (60)Co gamma rays used for comparison. When irradiated at 80 K, a much larger exposure (roughly 10 times) of soft X rays was needed to obtain the same signal intensity as that observed at room temperature. EPR signals were not detectable with gamma irradiation at liquid nitrogen temperature.