Optimal electric conditions in electrical impulse chemotherapy.

The relationship was examined between the tumoricidal effect and the electrical variables of in vivo electrical impulse chemotherapy. Donryu rats subcutaneously inoculated with AH-109AY hepatocellular carcinomas were given a single high-voltage electrical impulse of varying voltage and duration, 30 min after an intramuscular injection of 4 mg/kg bleomycin. As the voltage (V) was increased from 0 to 5 kV, the tumoricidal effect (E) increased in proportion to the square of the voltage. As the pulse duration (D) was increased from 2.5 to 5.8 ms, the tumoricidal effect increased in direct proportion to it. Combining these results yielded the formula, E = gamma V2D, which indicates that tumoricidal efficacy was proportional to the applied electrical energy. When the electrical energy was kept constant while varying the voltage and duration of pulse, the anticancer effect was the same, confirming this relationship for lower energy levels.

[The effect of menatetrenone on peritoneal adhesion].

The correlation between the dose of menatetrenone and the incidence of post-laparotomy peritoneal adhesion in Ryan's model was investigated with the use of rats. In the menatetrenone treated group, the menatetrenone was intramuscularly given in a dosage of 10 mg immediately after closure of the abdominal wound and every 24 hours for two days. In this group, the incidence of ceco-colonic adhesion was 54% (20/37), whereas the incidence in non-treated group was 26% (10/39) (p less than 0.012). Especially in cases with an air-drying time of 1-2 minutes, the difference between incidences of ceco-colonic adhesion in the menatetrenone and that of the non-treated group was high. The former incidence was 61% (17/28) and that of the latter was 21% (6/29) (p less than 0.01). In addition, the incidence of peritoneal adhesion was proportionally dose-dependent to the menatetrenone. In our clinical retrospective study, the incidence of post-gastrectomy adhesive ileus increased with menatetrenone treatment to a significant degree. It is concluded that prophylactic administration of a large dose of menatetrenone should be avoided, because the incidence of post-laparotomy peritoneal adhesion could be increased.

[Anticancer effect of high voltage pulses combined with concentration dependent anticancer drugs on Lewis lung carcinoma, in vivo].

Using high voltage pulse (initial electric field strength 3kV/cm, duration 4 msec, applied energy 14.9 joule) as a local load, and concentration dependent anticancer drugs such as peplomycin (PEP) 20 mg/kg, cyclophosphamide (CPA) 100 mg/kg, mitomycin C (MMC) 3 mg/kg and cisplatin (CDDP) 5 mg/kg administrated intraperitoneally, the effects on the suppression of primary lesions and on formation of pulmonary metastasis in the spontaneous pulmonary metastatic system of Lewis lung carcinoma were investigated. Though only CPA among single administrated anticancer drugs showed a suppressive effect against tumor growth, remarkable reduction in the size of primary lesions was obtained with a combination of high voltage pulse and an anticancer drug, regardless of various kinds of drug. A maximal ratio of size before and after treatment was 0.05 in PEP, 0.2 in CPA, 0.38 in MMC and 0.14 in CDDP. A combination of PEP or CPA with high voltage pulse had a particularly good effect, reducing the volume of the primary tumor after treatment less than levels before treatment throughout 2 weeks. The use of high voltage pulse alone did not affect any growth kinetics of the primary lesion. The number of pulmonary metastatic nodules was significantly reduced only by CPA among various kinds of single administrated drugs, whereas it was reduced by all treatments with a combination of high voltage pulse and each anticancer drug. The use of high voltage pulse alone did not result in any increase of the number of pulmonary metastatic nodules.(ABSTRACT TRUNCATED AT 250 WORDS)