RESUMEN
The photooxidation by ceric ammonium nitrate (CAN) of several aryl and naphthylcarbinols has been studied by means of ESR spectroscopy. For all the investigated arylcarbinols, but not for the naphthyl derivatives, it has been possible to detect radical intermediates deriving from the parent alkoxyl radicals. In particular, in the photooxidation of 1,1-diphenylethanol, a bridged-radical intermediate has been detected. The assignment has been validated through experiments with two different labeled compounds: the 1,1-[2', 3', 4', 5', 6', 2", 3", 4", 5", 6"-2H10]diphenylethanol and the 1,1-diphenyl[2, 2, 2-2H3]ethanol. A similar bridged radical has been found to be formed in the photooxidation of triphenylmethanol, while, for the 1,1-diphenylpropanol, the only detectable species has been the ethyl radical deriving from a competitive beta-scission process. Finally, for the 2-phenylpropan-2-ol (cumyl alcohol), two radical species have been identified: the methyl, deriving from the beta-scission process, and the cyanomethylene, deriving from H-abstraction of the cumyloxyl radical from the solvent. A kinetic study on the competition of the two processes has also been conducted and the parameters of the Arrhenius equation for the latter process have been estimated.
RESUMEN
The antiemetic efficacy of granisetron, ondansetron and tropisetron was evaluated in patients treated with cisplatin-Adriamycin (CDP/ADM) and ifosfamide (IFO) by continuous infusion (CI). In all, 90 patients with osteosarcoma were randomly assigned to receive granisetron (2 mg/m2), or ondansetron (5.3 mg/m2), or tropisetron (3.3 mg/m2) plus dexamethasone 8 mg/m2. Chemotherapy consisted of CDP (120 mg/m2, 48-h CI) followed by ADM (75 mg/m2, 24-h CI) and then, in the second cycle, delivered 3 weeks later, IFO 15 g/m2 (120-h CI). Complete protection (CP) from emesis was obtained on 59% of the 717 days of treatment, without significant differences among the three study drugs. A significantly higher rate of CP was obtained during chemotherapy with IFO than with CDP/ ADM (69% vs 44%; P<0.0001). The rate of CP declined from the first to the last day of treatment for both CDP/ADM (61% to 27%, P<0.0001) and IFO (95% to 43%) cycles (P<0.0001). When CDP/ ADM and IFO are delivered on multiple days by CI, granisetron, ondansetron and tropisetron have the same antiemetic efficacy, which declines from the first day onward through successive days.
Asunto(s)
Antieméticos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Óseas/tratamiento farmacológico , Osteosarcoma/tratamiento farmacológico , Vómitos/prevención & control , Enfermedad Aguda , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Niño , Preescolar , Cisplatino/administración & dosificación , Doxorrubicina/administración & dosificación , Esquema de Medicación , Extremidades , Femenino , Granisetrón/uso terapéutico , Humanos , Ifosfamida/administración & dosificación , Indoles/uso terapéutico , Masculino , Ondansetrón/uso terapéutico , Tropisetrón , Vómitos/inducido químicamenteRESUMEN
The relationship between the serum concentration of methotrexate and the prognosis has been studied in 108 patients with osteosarcoma of the extremities treated from September 1986 to December 1989 at the Chemotherapy Department of Rizzoli Hospital. The protocol of neoadjuvant chemotherapy included high doses of methotrexate (HDMTX) adriamycin, cisplatinum, ifosfamide and VP-16. After a median follow-up of 40.4 months (range 24-62), 84 (77.7%) of the patients studied remained continuously disease-free (CDF) and 24 relapsed. Significantly higher mean serum MTX concentrations were observed in the patients who remained CDF (669.5 mumol/l) than in the patients who relapsed (571.9 mumol/l) (p < .004). The breaking point of prognostic significance for the serum MTX levels seems to be 700 mumol/l. In fact, according to the mean MTX concentrations, the patients with less than 700 mumol/l showed a significantly lower disease-free survival than the patients with higher mean MTX concentrations (68.12% vs 94.87% p < .0013). The distribution of prognostic variables between the two groups was the same in terms of site and histological type of tumor and alkaline phosphatase serum levels at diagnosis. In the group which had more than 700 mumol/l MTX, a higher percentage of good histological response after primary chemotherapy was observed. This is probably independent from the MTX because no significant preoperative MTX serum levels between good and partially responding patients were observed.(ABSTRACT TRUNCATED AT 250 WORDS)