Selective potentiation of IGE-dependent histamine release from rat peritoneal mast cells by stem cell factor

Effect of stem cell factor on histamine release from rat peritoneal mast cells was studied. Although stem cell factor did not evoke histamine release by itself, it clearly potentiated histamine release from sensitized mast cells caused by antigen, anti-IgE and concanavalin A. However, stem cell factor did not affect histamine release caused by compound 48/80, calcium ionophore A23187 and substance P. Although maximum potentiation of antigen-induced histamine release by stem cell factor was accomplished after 1-10 minute-preincubation, potentiation was decline after a longer incubation period. Potentiation of histamine release by phosphatidylserine and non-mast cells in the rat peritoneal cavity was incubation time-dependent. Potentiation by stem cell factor was additive to that by phosphatidylserine or non-mast cells. These results indicate that stem cell factor selectively potentiates IgE-dependent histamine release from rat peritoneal mast cells, and suggest that the mechanism involved is distinct from that of phosphatidylserine or non-mast cells in the rat peritoneal cavity.

Possible involvement of beta 2-adrenoceptors in hyperthermic effect of l-ephedrine in rats

The experiments were conducted in order to examine the mechanism of hyperthermia induced by l-ephedrine in rats. beta-Adrenoceptor agonists have been known to enhance normal body temperature. Therefore, the effect of various beta-adrenoceptor agonists on body temperature in rats was examined to clarify the mechanism of action of l-ephedrine. The results showed that drugs with beta 2-adrenoceptor agonist activity and l-ephedrine caused hyperthermia in rats and this effect was selectively inhibited by pretreatment of animals with propranolol (a mixed beta-adrenoceptor antagonist) or butoxamine (a selective beta 2-adrenoceptor antagonist). These results suggest that hyperthermic action of l-ephedrine may largely be due to its effect on beta-adrenoceptors.

Suppression of natural killer activity in patients treated with cisplatin and methylprednisolone

The achievable concentrations of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl-3-nitrosourea (ACNU), adriamycin, mitomycin C, vindesine, and epipodophyllotoxin suppressed the natural killer (NK) activity of human peripheral blood lymphocytes in vitro, whereas NK activity was not decreased 24 h after incubation with the maximum achievable concentration of cisplatin (cDDP). NK activity of patients treated with 80 mg per square meter of cDDP alone was not decreased for 3 weeks after cDDP administration. In contrast, NK activity of patients treated with the same dose of cDDP and methylprednisolone was significantly decreased 1 week after cDDP administration. It was concluded that methylprednisolone, used as an antiemetic agent, had an immunosuppressive effect.

[Effect of CDDP administration on NK activity of human peripheral lymphocytes and its modification by corticosteroid as anti-emetic agent]

The effect of cDDP (cis-diamminedichloroplatinum) on NK (natural killer) activity of peripheral blood lymphocytes in 12 patients (7 primary lung cancer, 3 metastatic pulmonary tumor and 2 malignant mediastinal tumor) was examined with emphasis on the combination of corticosteroid. To all patients, 80 mg/m2 of CDDP was administered intravenously every 3 weeks. Four patients were treated with CDDP alone, and 8 patients received 375 mg of methylprednisolone on the same day of CDDP administration and 125 mg on each of following consecutive 5 days respectively. 1) NK activity was not suppressed for 3 weeks after CDDP administration, in the group of 4 patients without receiving corticosteroid. 2) Significant NK suppression was found 1 week after CDDP administration, and recovered 2 weeks later, in the group of 8 patients who were treated for their emesis by corticosteroid. It can be concluded that 80 mg/m2 of CDDP does not reduce NK activity at all. However, the additional administration of corticosteroid strongly inhibited NK activity. Therefore, one should be very careful when combines the corticosteroid in order to relieve emesis induced by CDDP treatment, even if it has some antiemetic effect.

[Analysis of the mechanism of cancer metastasis by using anticancer agents]

For the analysis of the mechanism of cancer metastasis, effects of anticancer agents on the NK activity of spleen cells and on the artificial metastasis of B-16 melanoma cells were comparatively studied. The inhibitory effect of these anticancer agents on the growth of B-16 melanoma inoculated to foot pad of C57/BL6 mice was also examined. The growth of B-16 melanoma was inhibited by intravenous administration of 6 mg/kg of MMC, 18 mg/kg of KW-2083 and 5 mg/kg of CDDP, but not of 6 mg/kg of KW-2083. The NK activities in spleen cells of C57/BL6 mice administered with 6 mg/kg of MMC and 18 mg/kg of KW-2083 were decreased, but they were not decreased in mice administered with 6 mg/kg of KW 2083 and 5 mg/kg of CDDP. Significant increases in the number of artificial pulmonary and liver metastasis were observed in mice administered with 6 mg/kg of MMC and 18 mg/kg of KW-2083. It is suggested that the depression of NK activity induced by anticancer agents results in the promotion of metastatic disease.

Analysis of metastatic spread and growth of tumor cells in mice with depressed natural killer activity by anti-asialo GM1 antibody or anticancer agents

The mechanism of artificial and spontaneous metastases of tumor was analyzed in B16 melanoma cells and C57BL/6 mice by using anti-asialo GM1 antibody and anticancer agents. Single administrations of 500 micrograms anti-asialo GM1 antibody resulted in significantly decreased NK activity in spleen cells of C57BL/6 mice, lasting 10 days from the day following administration. Treatment with anti-asialo GM1 antibody never decreased the function of T lymphocytes measured by blastogenesis with phytohemagglutinin or T cell growth factor. The tumoricidal functions of activated macrophages but not of resident macrophages were decreased by in vivo treatment with anti-asialo GM1 antibody. The anti-asialo GM1 antibody was evaluated in terms of the enhancing effect on pulmonary metastases with regard to the timing of administration. Treatment with anti-asialo GM1 antibody 1 day before or on the day of tumor inoculation resulted in a substantial increase in the number of artificial pulmonary metastases. In the experimental system of spontaneous metastases, anti-asialo GM1 antibody most effectively increased the number of pulmonary metastases when administered 1-2 weeks before the removal of primary tumor, when the tumor cells are thought to be released into blood circulation from the primary site. In addition, accelerated growth of transplanted tumors at the primary site was observed in mice treated with anti-asialo GM1 antibody. These results strongly suggest that anti-asialo GM1 antibody enhances the incidence of in vivo tumor metastases and the growth of transplanted tumor mainly by suppressing the function of NK cells. The maximum effective dose (MED) of mitomycin C or its derivative (M-83) suppressed NK activity significantly, and pretreatment with these anticancer agents enhanced the growth of the artificial pulmonary and liver metastases. In contrast, the MED of cDDP showed no effect on the NK activity or the numbers of pulmonary and liver metastases. These results indicate that the depression of NK activity induced by chemotherapy results in the promotion of metastatic disease. From these studies it can be concluded that NK cells have a key role in the control of metastases of malignant disease, and that support of NK activity is very important for the prevention of metastases.

[Double-blind comparison of L-keflex and cephalexin (Keflex) in dental infections (author's transl)]

In order to evaluate efficacy and safety of L-Keflex (granule form of sustained release cephalexin), a double blind study comparing it with Keflex (capsule of regular cephalexin) was conducted in dental infections. Evaluable cases in adults for efficacy of the drugs were 196 consisting of 97 for L-Keflex and 99 for Keflex. Those in children were 19 (8 for L-Keflex and 11 for Keflex). There were no significant differences in background of the patients and severity of the diseases between both groups (L-Keflex and Keflex groups). The daily doses used in both groups were 1,000 mg in adults and 500 mg in children, respectively. The dose was given in two divided doses for L-Keflex group and in four divided doses for Keflex group. Following are evaluation by the committee members for the study: Adults 1. Clinical response rate at final therapy day was 93.8% in L-Keflex group and 92.9% in Keflex group, showing no significant difference between both groups. 2. No significant difference in severity of subjective and objective symptoms between both groups was observed at each therapy day. 3. Side effects were found in 6.7% of 105 patients receiving L-Keflex and in 5.6% of 107 patients with Keflex, and there was no significant difference between both groups. As the side effects, gastrointestinal symptoms, rash and itching were observed, but no any other side effects were found in both groups. Children 1. As shown in the above, number of the cases enough to evaluate statistically was not obtained, but all of both groups clinically responded to the drugs. 2. As for side effects diarrhea was observed in only one patient of Keflex group consisting of 12 patients. In the patient, however, discontinuation of the drug was not required and the side effect disappeared during the therapy. From the above results, L-Keflex (granule) is judged to have more convenience than Keflex (capsule) in that (1) it can be administered with b.i.d. regimen and (2) it can be easily taken in dental patients such as patients having difficulty in opening mouth of swallowing pain.

Effect of coenzyme Q on blood-citrate and calcium levels and on the periodontium of citrated rats

Severe osteoporosis and some myelofibrosis of the alveolar bone developed in rats fed a citrate diet. The administration of coenzyme Q7 alleviated these histopathologic effects. It was also demonstrated that hypercitricemia with hypercalcemia found in the citrated rats were significantly restored to normal levels by coenzyme Q, administration.