The frequency of DNA double-strand breaks (dsb) was determined in yeast cells exposed to γ-rays under anoxic conditions. Genomic DNA of treated cells was separated by pulsed field gel electrophoresis, and two different approaches for the evaluation of the gels were employed: (1) The DNA mass distribution profile obtained by electrophoresis was compared to computed profiles, and the number of DSB per unit length was then derived in terms of a fitting procedure; (2) hybridization of selected chromosomes was performed, and a comparison of the hybridization signals in treated and untreated samples was then used to derive the frequency of dsb.

Medical treatment of cirrhotic ascites is essentially supportive, dictated by the patient's discomfort, impaired cardiovascular or respiratory function and potential for infection. Treatment of ‘simple’ ascites (moderate fluid accumulation, serum albumin > 3.5 g/dl, serum creatinine < 1.5 mg/dl, no electrolyte disturbance) is implemented sequentially. Only 10% of patients respond to dietary sodium restriction and bed rest; most require pharmacotherapy consisting of spironolactone, which increases the proportion of responding patients to 65% and loop diuretics, which may produce clinical improvement in an additional 20% (85% in all); in the remaining 15% of refractory patients, use of novel adjunctive therapies may be attempted. Patients with tense ascites, impaired renal function and electrolyte disturbances merit special consideration before diuretics are introduced. Spironolactone has long been a standard for the treatment of cirrhotic ascites because it directly antagonizes aldosterone. The loop diuretic most frequently added to spironolactone has been furosemide. However, there is preliminary evidence that torasemide may be more effective in some patients. Other investigational agents that may play a role in treatment of patients resistant to conventional drugs include ornipressin (a vasopressin analogue) and atrial natriuretic factor.