[Plasma, renal and tumor determination of total platinum during predictive tests of chemosensitivity of human tumor implants in the renal capsule in syngeneic mice].

During the study of chemotherapy responsiveness of twenty nine human tumors by 6 day subrenal capsule assay (SRCA), we measured, after cisplatinum regimen, the total platinum in human tumor implants and in mice plasma and renal tissue. The plasmatic (m = 0.36 +/- 0.

A nuclease that cuts specifically in the ribosome binding site of some T4 mRNAs.

We have identified a nucleolytic activity in Escherichia coli infected by bacteriophage T4 that introduces cuts in the ribosome binding site of at least two T4 mRNAs. Cutting takes place specifically in the GGAG sequences that are complementary to the 3' end of 16S rRNA (Shine-Dalgarno sequence). The nature of this nucleolytic cut has been investigated by reverse transcriptase mapping, anti-mRNA mapping, utilization of the vaccinia virus guanylyltransferase, and labeling by polynucleotide kinase.

[Pharmacokinetics in phase IV studies for the preview of a therapeutic protocol].

The pharmacokinetic studies of anticancer drugs still go on after they are out on the market. The therapeutic protocol is then more precise and depends on the dosage results of these drugs. Some examples of dosage adjustment according to their plasmatic level are reported here for high-dose methotrexate infusion and for CDDP infusion over five days.

Clinical pharmacokinetics of the antitumor drug navelbine (5'-noranhydrovinblastine).

Eleven patients with advanced cancer received navelbine (15 mg/m2) as a single i.v. bolus injection.

Methotrexate and 7-hydroxy-methotrexate pharmacokinetics following intravenous bolus administration and high-dose infusion of methotrexate.

The pharmacokinetics of methotrexate and 7-hydroxy-methotrexate were studied in patients undergoing very high-dose methotrexate monotherapy. The patients received, first, two methotrexate intravenous bolus test doses (50 mg/m2) one with and one without concomitant administration of folinic acid (15 mg every 6 h) in a random sequence, and, second, an 8 h infusion, individualized to achieve a peak plasma concentration of 5 X 10(-4) M methotrexate (infusion rates greater than 1000 mg/h). Methotrexate and 7-hydroxy-methotrexate concentrations were measured by specific radioimmunoassays and the data were analysed simultaneously by an integrated pharmacokinetic model.

Methotrexate test-dose protocol in the presence of 7-hydroxy-methotrexate.

Methotrexate (MTX) and 7-hydroxy-methotrexate (7-OH-MTX) plasma concentration-time curves (AUC) have been analyzed in 24 patients after different routes of MTX administration. After an i.v.

Differential effect of guanethidine on dopamine and norepinephrine pools in urine, heart and superior cervical ganglion in the rat.

The time-related changes of dopamine (DA) and norepinephrine (NE) pools were investigated in heart, superior cervical ganglion (SCG) and urine in rats treated chronically with guanethidine (50 mg/kg i.p. five days each week).

[Anthracyclines in the treatment of epidermoid cancers: uterine cervix, esophagus, bronchi, head and neck].

Anthracyclines certainly do not play a leading role in the treatment of squamous-cell carcinomas. Their effectiveness in these malignancies is limited. In carcinomas of the uterine cervix, variable therapeutic (partial or complete) response rates ranging from 0% to 25% have been reported with doxorubicin as single drug therapy.

6-day subrenal capsule assay (SRCA) as a predictor of the response of advanced cancers to chemotherapy.

The 6-day subrenal capsule assay (SRCA) chemosensitivity prediction test using fresh human tumor xenografts was performed in BALBc mice for 80 advanced cancer bearing patients. Among 97 SRCA, nine were non-evaluable because patients either received no chemotherapy or non-assayed drugs, and 12 were non-interpretable because of inadequate control growth. One hundred and six correlations were established between test results and clinical response, 56 retrospective (chemotherapy then test) and 50 prospective (test then chemotherapy).

Peripheral distribution of free dopamine and its metabolites in the rat.

Free dopamine (DA) and its metabolites, homovanillic acid (HVA) and 3-4 dihydroxyphenylacetic acid (DOPAC), have been measured and compared with norepinephrine (NE) concentrations in rat peripheral tissues using high performance liquid chromatography with electrochemical detection (HPLC-ED). Detectable amounts of DA and its metabolites were found in all the analyzed tissues. The highest levels were found in carotid body, sympathetic ganglia, urogenital tract and heart, the lowest in liver and lung.

Methotrexate-vindesine association in head and neck cancer: modification of methotrexate's hydroxylation in presence of vindesine.

High-dose methotrexate (HD-MTX) infusions associated with vindesine (VDS) have been used in the treatment of head and neck cancer. In a previous study, VDS was shown to increase the apparent plasma clearance of MTX. We have studied the MTX hydroxylation process in the presence of VDS.

[Pre and postoperative chemotherapy of osteosarcoma with an adriamycin-cisplatin combination. Risks of a neoadjuvant chemotherapy which is not sufficiently effective].

The authors evaluated a new protocol of neoadjuvant chemotherapy for osteosarcoma, easier to manage and different from T10. The good results obtained with the postoperative ADR-CDDP association led us to undertake a pilot study between 1982 and 1984, using ADR-CDDP as preoperative chemotherapy. The records of sixteen patients were available for follow-up.

Free and conjugated 3,4-dihydroxyphenylacetic acid and homovanillic acid in brain dopaminergic areas at basal state and after pipotiazine activation.

We have determined free and conjugated 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in discrete brain areas of rats. Conjugated HVA or DOPAC accounted for 22-38% of total acids in striatum, mesolimbic tissue or prefrontal cortex. Activation of dopamine (DA) metabolism by a single injection of pipotiazine palmitic ester (PPZ), a long-lasting neuroleptic, increased free acid levels (DOPAC and HVA) at either dose and conjugate levels after 32 or 50 mg/kg.

The dynamics of dopamine metabolism in the rat superior cervical, coeliac and mesenteric ganglia.

Dopamine (DA) metabolism was compared in rat superior cervical ganglion, coeliac ganglion, mesenteric ganglion and adrenal medulla. Substantial amounts of DA, 3-4 dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were found in all the above structures. The proportion of DA metabolites over total adrenergic compounds increased from the superior cervical (22 +/- 2.

Free, glucuronide, and sulfate catecholamines in the rat: effect of hypoxia.

The formation and excretion of conjugated catecholamines (CA) was studied in conscious rats after sympathetic stimulation by hypoxia (5.5-6% O2, 4 h). Hypoxia induced a rapid and intense increase of free epinephrine (E, X 12) and norepinephrine (NE, X 6) but only a limited enhancement of free dopamine (DA, X 2).

Bayesian estimation and prediction of clearance in high-dose methotrexate infusions.

Much attention has been paid to the problem of estimating the pharmacokinetic parameters of individual patients in order to optimize dosage choices. Individual kinetics determined by test-dose bolus injection are a basis for predicting drug concentrations after high-dose methotrexate infusion and for computing appropriate dosages. Simplifications may be attempted, even allowing the test-dose to be omitted by using Bayesian estimation rather than likelihood estimation.

The T4 mot protein functions as part of a pre-replicative DNA-protein complex.

Middle-mode RNA synthesis in T4-infected cells takes place before replication of phage DNA commences. What distinguishes it from early-mode RNA synthesis is that initiation of middle RNA depends on T4-coded proteins, in particular on the mot gene product. mot protein is localized in a DNA-protein complex which forms during the first few minutes of infection.

Dosage predictions in high-dose methotrexate infusions. Part 2: Bayesian estimation of methotrexate clearance.

Population pharmacokinetics of methotrexate (MTX) was evaluated from intravenous test-dose (TD) data (n = 20 corresponding to 174 measured samples). Bayesian prediction of MTX clearance from TD experiments combining population data with measured levels (at times 0.5 and 6 h) was found to be feasible in routine situations with good performance (root mean squared error : rmse (precision) = 1.

Dosage predictions in high-dose methotrexate infusions. Part 1: Evaluation of the classic test-dose protocol.

A preliminary methotrexate (MTX) kinetic evaluation following administration of an IV bolus (test-dose) allowed individualization of high-dose infusions (HD-MTX). This approach combined with therapeutic drug monitoring was found to have good performance over a large scale of predicted steady-state levels (Css) (10(-5) to 10(-4) M over 24 to 36 h) corresponding to 17 to 650 mg/h deliveries (root mean squared error : rmse (precision) = 1.54 X 10(-5) M (21.

Clinical pharmacokinetics of vindesine: repeated treatments by intravenous bolus injections.

Vindesine was administered intravenously to 12 patients with advanced cancer. Treatment was repeated after 2 weeks or more with a 1.5-to 2-fold increased dose of vindesine.

[Comparison of 2 chemosensitivity tests by grafting a polyoma tumor in the cheek pouch of syngeneic hamsters and under the renal capsule of syngeneic mice].

The immunocompetent subrenal capsule assay tumour graft is a good chemosensitivity test. We have compared it to immunocompetent white hamster cheek pouch tumour graft. These two assays are both easy to perform.

Studies on the central or peripheral origin of free and sulfated 3,4-dihydroxyphenylacetic acid in rat plasma.

The concentrations of free and sulfated 3,4-dihydroxyphenylacetic acid (DOPAC) were measured in rat plasma to investigate their potential central or peripheral origin. Stimulation of central dopamine (DA) metabolism by a long-acting neuroleptic, pipotiazine (PPZ) selectively increased plasma levels of DOPAC sulfate whereas peripheral inhibition of monoamine oxidase by debrisoquin sulfate decreased free DOPAC levels only. These data suggest that the two forms of plasma DOPAC (free and sulfate) may have independent topographic origins.