Higher apoptotic cell rate in Balkan endemic nephropathy--stereologic analysis.

The aim of this study was to correlate apoptotic cell rate from different nephron segments between control group and groups of patients with Balkan endemic nephropathy (BEN). Kidney specimens of20 patients with clinically and epidemiologically confirmed BEN were compared with biopsy material of 10 patients (group I, non BEN) without glomerular or tubulointerstitial disease. Out of 20 patients with BEN, 10 suffered and died from BEN (group II, BEN) and 10 patients (group III, BEN/CV) suffered from BEN but died from cardiovascular disease. Patient age ranged from 40 to 50 years. The apoptotic cell rate was measured in proximal and distal tubules and in collecting ducts using the 40X objective with a calibrated eyepiece multipurpose M 42 test system according to Weibel. Comparison of all three nephron segments yielded statistically significant differences in volume density of apoptotic cells in proximal tubules and in collecting ducts among all three patient groups (non BEN vs. BEN, non BEN vs. BEN/CV and BEN vs. BEN/CV, P<0.001 all). Statistically significant difference in apoptotic cell rate was also found in distal tubules between non BEN and BEN groups and non BEN and BEN/CV groups, but not between BEN and BEN/CV groups. Our results showed a statistically significant increase of apoptotic cells in all three nephron segments in patients with BEN (BEN and BEN/CV) compared to control group. The highest number of apoptotic cells was found in distal tubules in the groups of patients with BEN and BEN with coexisting cardiovascular disease, suggesting that these cells might be most frequently and most severely injured in patients with BEN.

Comparison of occurrence of upper urinary tract carcinomas in the region with endemic villages and non-endemic nephropathy region in Croatia.

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial renal disease of a still unknown etiology, associated with an increased frequency of urothelial carcinoma, particularly of the upper urinary tract (UUT). The aim of the study was to compare the occurrence of UUT carcinomas between Brodsko-Posavska Region (BPR) which is the region with endemic villages and the non-endemic region of Zagreb (ZG) in two six-year periods with a 20 year period separating the two, pointing out a possible difference in occurrence regarding war in Croatia (1991-1995). Comparing BPR and ZG regions we found a more then 5 times higher frequency of UUT carcinomas in BPR in the first period and more than 4.5 times higher frequency in the second period. Women in BPR were more frequently affected with UUT carcinomas.

Aristolochic acid and the etiology of endemic (Balkan) nephropathy.

Endemic (Balkan) nephropathy (EN), a devastating renal disease affecting men and women living in rural areas of Bosnia, Bulgaria, Croatia, Romania, and Serbia, is characterized by its insidious onset, invariable progression to chronic renal failure and a strong association with transitional cell (urothelial) carcinoma of the upper urinary tract. Significant epidemiologic features of EN include its focal occurrence in certain villages and a familial, but not inherited, pattern of disease. Our experiments test the hypothesis that chronic dietary poisoning by aristolochic acid is responsible for EN and its associated urothelial cancer. Using (32)P-postlabeling/PAGE and authentic standards, we identified dA-aristolactam (AL) and dG-AL DNA adducts in the renal cortex of patients with EN but not in patients with other chronic renal diseases. In addition, urothelial cancer tissue was obtained from residents of endemic villages with upper urinary tract malignancies. The AmpliChip p53 microarray was then used to sequence exons 2-11 of the p53 gene where we identified 19 base substitutions. Mutations at A:T pairs accounted for 89% of all p53 mutations, with 78% of these being A:T --> T:A transversions. Our experimental results, namely, that (i) DNA adducts derived from aristolochic acid (AA) are present in renal tissues of patients with documented EN, (ii) these adducts can be detected in transitional cell cancers, and (iii) A:T --> T:A transversions dominate the p53 mutational spectrum in the upper urinary tract malignancies found in this population lead to the conclusion that dietary exposure to AA is a significant risk factor for EN and its attendant transitional cell cancer.

External laryngotracheal trauma.

Differences in acute external injuries of the larynx and cervical trachea between peace-time and war trauma were studied. Twenty-six patients with peace-time injuries and 39 patients with war injuries were retrospectively analyzed. The incidence of peace-time laryngotracheal injuries was 0.91% of the total number of patients hospitalized for head and neck injuries. In the groups of wounded in action (WIA) and killed in action (KIA) with head and neck war injuries, the incidence of laryngotracheal injuries was 4.8 and 6.2%, respectively. According to the type of the wound, blunt injuries were most common among peace-time and penetrating wounds among war injuries. There was no difference between peace-time and war injuries according to the wound localization. War wounds were more severe, caused more extensive local tissue and organ defects, were associated with a greater number of lesions to the neck and other body regions and more often required reconstructive surgical procedures than peace-time injuries. The mortality of war laryngotracheal injuries was two times greater than that of peace-time lesions (9 vs. 3.8%).