BALKAN ENDEMIC NEPHROPATHY AND MALIGNANT UROTHELIAL TUMORS

One of the features of Balcan endemic nephropathy (BEN) is higher frequency of urothelium malignant tumors, primarily of pyelon (Mtp) and urether (Mtu). Jablanica region is known for the presence of endemic, hypoendemic and non-endemic areas with BEN. The aim of our research was to analyze the appearance of MTUi n endemic settlements of Jablanica region with BEN and to see what the relation of tumor frequency between endemic and non-endemic settlements is. The appearance of MTU was analyzed on the basis of operative protocol data of Urology department, The Health Center in Leskovac and Urology Clinic of The Clinical Center in Nis for the period from 1978 to 2002. We collected data about our patiens regarding their sex, age, the place of living and the place of birth. In order to make classification of settlements we used data of the Institute for Nephrology and hemodialysis (INH) in Nis. Data on total number of population living in these settlements were obtained from the official registration data published in 1981 and 1991. The incidence rate was calculated in the sample of 100,000 people.The average annual incidence rate (AAIR) of MTU in endemic settlements for the considered period is 37.82 (tumors of urether and pyelon - 17.56; malignant tumors of urinary bladder (MTUB 20.26); in hypoendemic settlements the rate is 13.28 (MTp and Mtu - 5.06; MTUB - 8.22); and in non-endemic urban settlements it is 7.35 (Mtu and MTp - 1.04, MTUB - 6.31).AAIR of MTU in endemic areas is 2.85 times higher when compared to hypoendemic areas; it is 6.75 times higher than in non-endemic urban areas, and 5.15 times higher than the rate of non-endemic rural areas. Mtu and MTp are 18.68 times more frequent in endemic settlements than in non-endemic urban areas and 3.47 times more frequent when compared to hypoendemic settlements. The linear trend of the diseased from MTp and MTu in endemic areas of Jablanica region for 25-year period was slowly decreasing according to statistics (y= -0.0054x + 0.59; r2=0.0031.High frequency of Mtu, primarily of Mtu and MTp in areas with BEN, probably points to the common nephropathogenic and cancerogenic etiologic factor, confirming thus the existence of positive correlation between BEN and malignant tumors of upper urothelium (MTUU)

SELENIUM EFFECT UPON THE RATS' HEMATOPOIESIS IN THE SUBACUTE BENZENE INTOXICATION

The antioxidants (selenium, vitamins C and E) stabilize the cell membrane andprotect the cells from the action of free radicals. On the other hand, the antioxidantsreduce the effects of chemical and physical agenls. Bcsidcs, selenium has animportant role in Transporting electrons in the mitochondria and il is necessary for iheglulathione peroxidase function in the protection from apoplhosis. Benzene is auniversal solvent and has a wide application in chemical industry. Its toxicity ismanifested in the damages done to the central nervous syslem, liver, kidneys andhematopoiesis system. Tn this experiment the Wistar rats were used that wereclassified in three experimental groups regarding the quantity of the receivedselenium. Each group comprised ten animals of both sexes and after two weeks'treatment by selenium of 4,8 and 16 mcg, the animals had received benzene byinlraperiloneal administration in the dose of 1,2 ml/kg of the body weight. Thecounting of the shaped blood elements was done after the selenium pretreatment andafter the benzene intoxication. The obtained results poinl to increased number of alithe blood elements after the selenium pretreatment while after benzene adminislrationthere was a drastic drop of the number of erylhrocyles and leukocytes alongwith moderate lhrombocylopenia. After the sacrifice, Ihe hematopoiesis organs weretaken. The hislological findings of the bone marrow show the emergence ofdisturbances, especially of the red sort cells as well as an obvious fat degeneration which is particularly conspicuous in the second and third groups of animals. Therewas also some damage done to the spleen, especially of its red pulp along with thepresence of a greater number of fresh erythrocytes in the second and third groups.Only the changes were more drastic in the third group. The obtained results show thatselenium in higher concentrations increases the number of erytrocytes andleukocytes which proves that it stimulates highly-proliferating cells of the bonemarrow. However, after the intoxication by a sub lethal benzene dose there was a dropof the cells of red and white color but these values are within the normal limits. Thispoints to the fact that the emergence of death is not in any direct correlation with thedisturbances in the hematopoiesis, but death was caused by the damage done to someother vital organs. Despite the fact that selenium prevents the cells' damage, in thisčaše its protective effect manifested itself only when it was given in small doses sincethere was no death in this group of animals