[Thermochemotherapy for malignant melanoma--combination therapy of ACNU and hyperthermia in mice]

The effect of a combination therapy of hyperthermia (43 degrees C, 30 min) and ACNU (10 mg/kg) on B 16 melanoma and C 24 melanoma in vivo was studied. This combination therapy was effective in both melanoma. In C 24 melanoma, remarkably the tumor regression and the partial destruction of the histological structure, were observed.

Automated analysis of alditols by anion-exchange chromatography with photometric and fluorimetric postcolumn derivatization

Eight alditols were separated in ca. 80 min as their borate complexes by stepwise elution with three borate buffers on a column packed with Hitachi 2633 resin. The alditols in the eluate were derivatized automatically to colored, fluorescent products by applying sequential reactions of periodate oxidation and Hantzsch condensation, and the products were detected either photometrically or fluorimetrically. This automated method allowed simultaneous determination of 20-500 and 20-200 nmol amounts of alditols by photometric and fluorimetric monitorings, respectively. The lower limits of detection were ca. 2 and 0.5 nmol, respectively. The interference by aldoses was slight. Aldoses may be also determined as alditols by direct injection of aqueous solutions to which excess amounts of sodium borohydride have been added. This method was applied with success to urinary alditol assay and to molecular weight determination by end group analysis.

The immunomodulatory action of inosiplex in relation to its effects in experimental viral infections

The effect of inosiplex (Isoprinosine) on viral replication, experimental viral infections and host immune functions has been examined. Inosiplex was found to have a broad spectrum of antiviral activity, inhibiting the RNA viruses, influenza (INFV) and parainfluenza (PIV), as well as the DNA viruses, herpes simplex (HSV) and vaccinia (VACV). However, the antiviral effects were modest when compared to amantadine and adenine arabinoside (ARA-A). Inosiplex in vivo caused a statistically significant increase in survival of treated animals (hamster, mice) infected with RNA or DNA viruses. This effect of inosiplex was apparent in animals which were previously immunosuppressed. Inosiplex, at optimal dose, conferred total protection in treated mice against secondary influenza infection. Since this was accompanied by statistically significant increases in serum anti-hemagglutinin and anti-neuraminidase titers, an effect of inosiplex on host defenses against secondary viral infection was implicated. This effect was further demonstrated by passive transfer of protection by splenocytes from inosiplex-treated donors to untreated recipients. Inosiplex was found to enhance the mitogen- (PHA-, ConA and MLC-) induced blastogenesis of lymphocytes from untreated mice. The LPS response was not affected. Inosiplex added in vitro caused a dose-dependent increase in the primary immune anti-SRBC response in vitro, as determined by direct and indirect PFC; there was also a dose-dependent effect on the secondary in vitro direct and indirect PFC responses. Inosiplex in vivo enhanced the primary immune response to SRBC, as determined by direct PFC assay; this was also the case for immunosuppressed mice. The drug enhanced delayed type hypersensitivity to picryl chloride in the mouse. Macrophage function was also enhanced by inosiplex, as was apparent from phagocytosis of SRBC. Gamma interferon production from murine lymphocytes was augmented by inosiplex in vitro. Treatment with inosiplex had no effect on natural killer cells or on antibody dependent cellular cytotoxicity. Thus, the pronounced effect of inosiplex on secondary viral infections may result through two different mechanisms: a direct antiviral effect and an elevation of multiple parameters of host immunity, which are usually compromised during viral infection. The latter mechanism may be the more important.

Evidence for "response to injury" hypothesis

Role of platelet-derived growth factor (PDGF) in myointimal thickening described in "response to injury" hypothesis was investigated with artery of rats in culture and with air-injured artery of rats. PDGF promoted cell growth in ring preparation of carotid artery in culture denuded with citrate. It did not promote any cell growth in preparations without denudation. Trapidil, a PDGF antagonist, inhibited the cell growth promoted by PDGF in the denuded arterial ring. Systemic injection of PDGF was performed for 8 days to rats with thrombocytopenia induced by injections of anti-platelet serum. This treatment caused myointimal thickening of carotid artery 10 days after denudation by means of air injury. Trapidil at oral intake levels of 1, 3 and 30 mg/kg/day inhibited this change observed in denuded site of artery. Trapidil at oral intake of 6 mg/kg/day also inhibited myointimal thickening observed 15 days after denudation of carotid artery by air injury in normotensive and spontaneous hypertensive rats both with normal platelet counts. These results evidenced the role of PDGF in myointimal thickening described in "response to injury" hypothesis and clinical use of trapidil may be a new approach to the treatment of atherosclerosis.

Antithrombotic activity and the mechanism of action of trapidil (Rocornal)

Antithrombotic activity and the mechanism of action of trapidil were investigated, as compared with those of aspirin and dipyridamole. Trapidil at oral doses of 30 and 100 mg/kg inhibited arterial thrombosis in rats, while aspirin and dipyridamole at doses up to 300 mg/kg showed only a mild activity. This action may be explained by the fact that trapidil at concentrations ranging from 139 microM to 251 microM exerted 50% inhibition of platelet aggregation induced by ADP, arachidonic acid, thrombin or thromboxane A2 mixture, inhibition of platelet release reaction induced by ADP, arachidonic acid or thrombin, disaggregatory effect on aggregated rabbit platelets by arachidonic acid and potentiating action on antiaggregatory action of prostacyclin in vitro. In vitro actions of trapidil were apparently different from those of aspirin and dipyridamole. Trapidil also showed inhibition of platelet phosphodiesterase activity and thromboxane synthetase activity. Trapidil was expected to be an effective antithrombotic agent. The antithrombotic action of trapidil may be mediated by the inhibition of platelet function which is characterized by the inhibition of both thromboxane synthetase and phosphodiesterase activities, and by the potentiation of the antiaggregatory action of prostacyclin.

Antiviral activity of sodium 5-aminosulfonyl-2,4-dichlorobenzoate (M12325)

Sodium 5-aminosulfonyl-2,4-dichlorobenzoate (M12325) was evaluated for antiviral activity in tissue culture and infected mice. At concentrations ranging from 2.5 to 75.8 micrograms/ml, M12325 inhibited the cytopathic effects of 10 mean tissue culture infective doses of influenza virus A/WSN, A/FM, A/Kumamoto, and B/Great Lakes; parainfluenza virus; rhinovirus; echovirus; respiratory syncytial virus; and vesicular stomatitis virus. Concentrations up to 150 micrograms/ml did not inhibit the cytopathic effects of herpes simplex virus, vaccinia virus, or adenovirus. Concentrations up to 3,160 micrograms/ml did not inhibit the growth of MDCK, Vero, or HEL cells in culture. Single oral doses of M12325, ranging from 10 to 300 mg/kg, administered 1 h before and 1 h after challenge, reduced mortality in mice inoculated intranasally with influenza A/WSN virus. Twice daily oral doses for 14 days effected significant reductions in the mortality of mice infected intranasally with influenza A/WSN, A/FM, A/Kumamoto, and B/Great Lakes, and parainfluenza virus, but they were not effective in mice infected with herpes simplex virus. Multiple doses of 10 and 30 mg/kg, administered intraperitoneally, reduced lung consolidation and virus titer. M12325 was well tolerated in multiple doses up to 1 g/kg orally. These observations support the conclusions that M12325 has a broad spectrum of activity against RNA viruses in vitro and in vivo, selective toxicity, and a large margin of safety.

Rapid changes of serum vasoactive intestinal peptide after removal of ganglioneuroblastoma with watery-diarrhea-hypokalemia-achlorhydria syndrome in a child

A 23-month-old girl with intractable diarrhea that had persisted for the past 6 months showed typical evidence of water-diarrhea-hypokalemia-achlorhydria (WDHA) syndrome. Serum vasoactive intestinal peptide (VIP)-like immunoactivity was very high, and urine homovanillic acid and noradrenaline were also abnormally increased. A calcified tumor in the right paravertebral region was noted radiologically. Soon after resection of the tumor, the diarrhea dramatically improved. A ganglioneuroblastoma was histologically confirmed. Serum VIP decreased to normal level at 1 h after the removal of the tumor. VIP activity in the tumor was extraordinarily high, and the cells were stained by the indirect immunofluorescence technique with anti-VIP serum. This is to report the rapid turnover of serum level of VIP after resection of ganglioneuroblastoma with WDHA syndrome in a child.

Soluble and particle-bound trehalase in the silk glands during larval-pupal development of the silkworm, Bombyx mori

Trehalase localization in silk glands of the silkworm, Bombyx mori has been studied during larval-pupal development. Subcellular distribution of the silk gland trehalase depends upon larval-pupal development. The activity increases in the soluble fraction with a concomitant decrease in the particle-bound fraction during larval-pupal development. The pH-optimum value of trehalase activity in the particle-bound fraction changes from 6.5 to 6.0, and in the soluble fraction from 5.5 to 4.5 in the course of the silk gland degeneration during metamorphosis.