[Cultivation of urologic and male genital tumor cells]

Thirty specimens from 30 patients with urologic and male genital system tumors were cultured. Eighteen (60%) showed initial cell growth. Four (13%) were successful in primary culture. In a renal cell carcinoma and a bladder transitional cell carcinoma, the subcultures were successful after the primary culture. In eight months, having transferred the former for twelve generations and the latter for twenty-seven generations, these two cell lines are established. The morphological characters of the cultured cells, eradication of fibroblasts, conditions of culture and prevention of contamination are discussed.

Comparison of ramp and stepwise incremental pacing in assessment of antegrade and retrograde conduction

Conventional assessment of antegrade (AV) and retrograde (VA) conduction involves stepwise increments in pacing rates until block in conduction is observed. This study was designed to establish the comparative characteristics of ramp pacing, in which the rate is continuously and smoothly incremented until block occurs. Two hundred and ten patients participated in portions of this study. Stepwise pacing was performed in 10 beat/minute steps, with the rate held for at least 15 seconds at each step; if marked prolongation or variability in conduction was observed, the rate was held constant for up to 60 seconds to allow for accommodation. With ramp pacing, the rate was gradually increased at a steady 2-4 beats/minute/second. Whenever possible, both stepwise and ramp pacing were performed for assessment of both antegrade and retrograde conduction. All patients had conducted sinus rhythm as their baseline mechanism. Antegrade conduction was similar using incremental stepwise and ramp pacing. The AH interval at a cycle length (CL) of 500 ms, the maximum AH increment, the cycle length at AV block were all remarkably similar (p = NS). Assessment of retrograde conduction produced similar results, with insignificant differences between maximum conducted VA intervals, and cycle length at VA block using the two pacing techniques. Ramp pacing provides a useful and rapid alternative to conventional stepwise incremental pacing in the assessment of antegrade and retrograde conduction in patients using both normal and accessory pathways. Ramp pacing was better tolerated, and some correlations between antegrade and retrograde conduction were stronger with the ramp pacing technique.

Cardiovascular effects of ketanserin in conscious rabbits

The antihypertensive effects of intravenous injection of ketanserin, a 5-HT2 receptor antagonist, were assessed in conscious rabbits. In intact rabbits, ketanserin lowered blood pressure in a dose-dependent manner. The antihypertensive effects of ketanserin were also observed in rabbits with two-kidney, one clip (2K1C) hypertension and with one-kidney, one clip (1K1C) hypertension. The effect was more marked in the 1K1C rabbits with low plasma renin activity (PRA) and high plasma norepinephrine (PNE) than in 2K1C rabbits with high PRA and normal PNE. The heart rate was not changed. Ketanserin suppressed the pressor response to exogenous norepinephrine (0.6 micrograms/Kg) 15, 30 and 45 min after the injection of ketanserin (1 mg/Kg). It also suppressed the pressor response to phenylephrine (3 micrograms/Kg) 15 min after the injection, but it did not suppress the pressor response to angiotensin II (0.15 micrograms/Kg). In order to investigate baroreceptor function, balloons were placed around the abdominal aorta and the inferior vena cava and inflated alternately. Thus, the mean arterial pressure vs heart period-logistic curve was obtained under steady-state conditions. There were no changes after the drug administration in the range of heart period and the gain (the slope at midpoint of the curve). These results suggest that the inhibition of pressor response of norepinephrine has effects in addition to a direct vasodilatory action and that an alteration of baroreceptor function is not involved in the antihypertensive effects of ketanserin.