RESUMO
A high-dispersion spectrum of Comet C/1999S4 (LINEAR) was obtained in the optical region with the high-dispersion spectrograph on the Subaru telescope when the comet was 0.863 astronomical units from the Sun before its disintegration. We obtained high signal-to-noise ratio emission lines of the cometary NH2 bands from which an ortho-to-para ratio (OPR) of 3.33 +/- 0.07 was derived on the basis of a fluorescence excitation model. Assuming that cometary NH2 mainly originates from ammonia through photodissociation, the derived OPR of NH2 molecules should reflect that of ammonia, which provides information on the environment of molecular formation or condensation and of the thermal history of cometary ices. Assuming that the OPR of ammonia in comets was unchanged in the nucleus, the derived spin temperature of ammonia (28 +/- 2 kelvin) suggests that a formation region of the cometary ammonia ice was between the orbit of Saturn and that of Uranus in the solar nebula.
Assuntos
Amônia , Meteoroides , Gelo , Análise Espectral , TemperaturaRESUMO
A clinical trial of a protracted adjuvant cancer chemotherapy was carried out on 207 patients with operable gastric cancer, from April, 1977, in the First Department of Surgery, Chiba University Hospital and two closely related hospitals. These patients were given intravenously 0.4 mg/kg and 0.2 mg/kg of mitomycin C on the day of operation and the next day, respectively, and then 16 mg/kg intravenously of Futraful (FT-207) daily from the 10th postoperative day until discharge, followed by oral administration of FT-207, 12 mg/kg, for 24 to 36 months after discharge. Two mg/kg of phenobarbital and 30 mg/kg of glutathione were administered randomly to half the number of patients (induction group) to induce hepatic drug-metabolizing enzymes. Significantly higher levels of serum 5-Fluorouracil (5-FU) released from FT-207 were found in the induction group than in the controls. Five-year overall survival rates in the induction and control groups revealed no difference. However, the survival rates in Stage III patients in the induction group were significantly superior in the 3-5 postoperative years, compared to those in the Stage III of the control group, while Stage I, II and IV patients apparently received no benefit from this induction treatment.
Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Fluoruracila/análogos & derivados , Glutationa/administração & dosagem , Microssomos Hepáticos/enzimologia , Fenobarbital/administração & dosagem , Neoplasias Gástricas/tratamento farmacológico , Tegafur/administração & dosagem , Ensaios Clínicos como Assunto , Quimioterapia Combinada , Indução Enzimática , Fluoruracila/administração & dosagem , Fluoruracila/metabolismo , Humanos , Distribuição Aleatória , Neoplasias Gástricas/mortalidade , Fatores de TempoRESUMO
Studies of an intensified chemotherapy of FT-207, combined with MMC, have been under way since April 1977 in the First Department of Surgery of Chiba University Hospital and five closely related hospitals. These studies were performed on 114 patients with curative stomach cancer. The 114 patients received intravenously 0.4 mg/kg and 0.2 mg/kg of MMC on the operation day and the next day, respectively, and then intravenously 800 mg of FT-207 daily from the 10th postoperative day until discharge, followed by oral administration of FT-207, 600 mg, for more than 1 year after discharge. The 114 patients were divided into two groups. Half of the patients received 100 mg of phenobarbital and 30 mg/kg of glutathione for the purpose of induction of hepatic drug-metabolizing enzymes (induction group). Significantly higher levels of serum 5-FU released from FT-207 were observed in the patients of the induction group when compared to those of the control group. However, there was no statistically significant difference in survivals at both 12 and 24 months after operation between both groups.