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Biomedical subjects

C Aubert

Publications and source records attributed to C Aubert.

At least 91 records · Page 5Linked to original sources
PubMed1986

Malnutrition in the Third World.

The causes of malnutrition are discussed--lack of money for food; and insufficiency of food production. It is stressed that much agricultural land is employed for purposes other than the production of food. Other causes of malnutrition include changes in local food habits and in food technology. Remedies discussed include increasing yields by organic manuring and mixed cropping; devoting more land to staple food production; changes in food habits and in food technology. Until these problems are addressed in Western societies there is little prospect of suitable solutions amongst the peoples of the Third World.

Agriculture↗
PubMed1986

[Lightning injury of the ear].

Three cases of auricular fulguration are described and used as a basis for a review of physical characteristics and histopathologic consequences of lightning strikes. Cases are presented and discussed in relation to these fundamental and experimental data.

Audiometry↗
PubMed1985

Determination of clobazam, N-desmethylclobazam and their hydroxy metabolites in plasma and urine by high-performance liquid chromatography.

Owing to the pharmacological and clinical importance of the determination of plasma and urine levels of the hydroxy metabolites of clobazam and N-desmethylclobazam in healthy volunteers and in epileptic patients, a high-performance liquid chromatographic (HPLC) method was developed that permits the determination of all these compounds in the same plasma or urine sample. The method involved ether extraction at pH 13 with diazepam as internal standard for the measurement of clobazam and N-desmethylcobazam, followed by ether extraction at pH 9 with nitrazepam as internal standard for the measurement of the hydroxy derivatives. The limit of detection was about 10-20 ng/ml for each of these compounds. Applications to patients were limited by chromatographic interferences between the hydroxy metabolites and some medications currently associated with clobazam in the treatment of epilepsy. The only interference in clobazam and N-desmethylclobazam analysis was from N-desmethyldiazepam. Despite these inconveniences, this HPLC procedure appears to be the only available method for the simultaneous quantification of clobazam and its three main metabolites.

Anti-Anxiety Agents↗
PubMed1985

Plasma determination of 3-methylclonazepam by capillary gas chromatography.

A capillary gas-liquid chromatographic method for the determination of 3-methylclonazepam in plasma was developed. This method involved a single extraction by butyl acetate followed by analysis of the organic extract on a CP-Sil 5 glass capillary column with detection by electron capture. The detection limit was about 0.1 ng/ml, and the inter- and intra-assay precision did not exceed 8% for the concentration range 0.1-6.0 ng/ml. Specificity towards some of the possible metabolites in human plasma was demonstrated. This method was used for the measurement of the pharmacokinetic parameters of 3-methylclonazepam in healthy volunteers after a single intravenous administration of 1 mg, and oral administrations of 1 and 4 mg.

Benzodiazepinones↗
PubMed1985

[Metastatic melanoma B16 of the C57Bl/6J mouse. Biological findings].

Biological study of a new metastatic variant of C57Bl/6J mice melanoma MB16 derived from a (poorly) invasive tumor (B16), are reported. We showed significative differences in tumor growth (female) and in pulmonary metastasis occurrence. Differentiation is weakly modified.

Animals↗
PubMed1984

Differences in surface sialic acid and galactosyl residues of two autologous human melanoma cell lines.

Cell surface carbohydrate differences were observed between two human cell lines initiated from primary melanoma and metastasis of the same patient. Although total sialic acid content was similar in both cell lines, neuraminidase-released sialic acid was twice as high in metastatic cells than that of primary cells. One class of Concanavalin A binding sites with similar affinity constant was found in untreated and neuraminidase-treated cells in both cell lines. Before surface sialic acid release, the primary cell line expressed two classes of Ricinus lectin binding sites with high and low affinity; the cell line of metastatic origin had only one class of Ricinus lectin binding sites with low affinity. After neuraminidase treatment, the number of Ricinus lectin binding sites with low affinity increased two- or three-fold in both cell lines, whereas the high-affinity binding sites were not observed in primary cells. The present data indicated that differences in surface sialic acid level modified the Ricinus lectin binding in two human melanoma cell lines. However, the ability of the cells to bind Concanavalin A was not changed.

Adult↗
PubMed1984

DTIC and CPZ cytotoxicities on established human melanocyte cell lines.

We report the effects of one cytostatic and one anti-emetic, DTIC and chlorpromazine (CPZ), on eight established human melanocyte cell lines using 3 methods of evaluation. Considerable differences in chemo-sensitivity to DTIC were discovered. Both inhibition, stimulation and no effect were seen. CPZ always showed cytotoxic effect in vitro. DTIC combined with CPZ had an antagonistic effect except for one cell line which was synergistic. From the chemosensitivity obtained with a primary tumor, it was impossible to predict that of its metastasis. Two similar metabolic effects in vitro were not necessarily related to identical therapeutic sensitivity in vivo. At least 3 significant results must be obtained in vitro to predict a therapeutic schedule.

Cell Division↗
PubMed1984

Ia-like antigen expression on biologically different human melanoma cell lines.

Ia-like antigen binding of a large panel of monoclonal antibodies (six anti-human Ia-like monoclonal antibodies and ten murine anti-Ia monoclonal antibodies cross-reactive with human Ia-like antigens) were compared on seven permanent human melanoma cell lines by radioimmunoassay. Cell lines were initiated from primary or metastatic tumors and presented various levels of tumorigenicity (assessed by heterotransplantation in nude mice) and pigmentation (shown by 5-S-cysteinyldopa determination and cytological data). Two cell lines originated from the same primary melanoma, while two other pairs of cell lines originated from superficial spreading melanoma or metastatic lymph node of the same patients. Identical Ia-like allodeterminants were found in cell lines of the same individual origin. Quantitative expression of beta 2-microglobulin and Ia-like antigens was similar in all cell lines except for one, in which these molecules were expressed in lower amounts. These results indicate that Ia-like antigen expression of the cell lines is unrelated to primary or metastatic origin, degree of pigmentation and ability to grow in nude mice.

Adult↗
PubMed1984

Differentiation and tumorigenicity of human malignant melanocytes in relation to their culture conditions.

The effects of variations in the concentrations of L-cystine (Cys), L-methionine (Met), and L-glutamine (Glu) on the establishment of melanocyte cell lines obtained from a primary tumor and its metastasis in the same patient were studied. The special role of Glu was also studied in 4 lymph node metastases from other patients. Differentiation in vitro was dependent on the culture conditions, as assessed by morphologic and biochemical studies. Karyologic expression, doubling time, cloning efficiency, and tumorigenicity in nude BALB/c mice varied widely among the cell lines. Cys was an indispensable amino acid and Glu was not. Met and Glu were implicated in melanogenesis. From these observations arose the question of the accuracy of comparative results, concerning differentiation and tumorigenicity, that had been collected for cell lines obtained under different culture conditions.

Animals↗
PubMed1983

Simultaneous assay of triazolam and its main hydroxy metabolite in plasma and urine by capillary gas chromatography.

A gas--liquid chromatographic method for the simultaneous determination of triazolam and its major hydroxy metabolite (1-hydroxymethyltriazolam) in human plasma and urine is described. After addition of two internal standards to the biological fluid, extraction at pH 9, acid washing, back-extraction, and derivatization, the analysis was performed on a wall-coated superior capacity open-tubular (WSCOT) CP-Sil 5 capillary column with electron-capture detection. The detection limit was 0.1-0.2 ng/ml; reproducibility was about 6-7% for plasma concentrations below 1 ng/ml. No interference from other possible minor hydroxy metabolites of triazolam was found. Gas chromatography coupled with mass spectrometry validated the chromatographic results. The method was successfully applied to plasma specimens collected from healthy human volunteers following a single intravenous administration of 1 mg of triazolam or 1-hydroxymethyltriazolam.

Anti-Anxiety Agents↗
PubMed1983

Dielectrophoresis of malignant human melanocytes.

Dielectrophoretic experiments on pearl-chain formation and collection of human melanocytes were performed as a function of the frequency of the applied nonuniform electric field. Evidence is reported showing that the behavior of malignant melanocytes is markedly dependent upon the type of established cell line (pigmented or achromic), age, and drug treatment (e.g., chlorpromazine).

Cell Line↗
PubMed1983

Kinetics and metabolism of a new fluoropyrimidine, 5'-deoxy-5-fluorouridine, in humans.

5'-Deoxy-5-fluorouridine (5'-dFUrd) is a new antineoplastic agent which possesses a higher therapeutic index in several experimental tumors compared to other fluoropyrimidines. During a Phase I trial, 5'-dFUrd, 1 to 15 g/sq m/week, was administered to patients as a 25- to 35-min i.v. infusion. Plasma kinetics and metabolism of 5'-dFUrd were investigated. The unmetabolized drug was measured by a high-performance liquid chromatography assay. 5-Fluorouracil and 5,6-dihydrofluorouracil, the two detected plasma metabolites, were quantitated by a gas chromatography-mass spectrometry methodology with a detection limit of 0.07 microM for both metabolites. The disposition of 5'-dFUrd in humans at therapeutic doses followed a nonlinear kinetic process. Plasma concentrations of 5-fluorouracil generated in vivo represented approximately 6% of 5'-dFUrd concentrations and the 5-fluorouracil half-life ranged from 8.8 to 27.1 min. High plasma values of 5,6-dihydrofluorouracil (14.5 to 30 microM) were observed in patients, indicating the importance of this pathway in humans.

Colonic Neoplasms↗
PubMed1983

Determination of chloroquine and monodesethylchloroquine in hair.

Using thin-layer and gas chromatography and mass spectrometry, chloroquine and its major metabolite (monodesethylchloroquine) were identified in hair samples of numerous patients who received this antimalarial drug for several months. In two patients the amounts of chloroquine were, respectively, 310 and 145 mg/kg hair and those of the monodesethylchloroquine 23 and 11 mg/kg. The respective proportions (93 and 7%) are the same in the two subjects. The chloroquine percentage was near those in the spleen or stomach wall after poisoning. Other metabolites in hair are being identified. Hair analysis may provide a good toxicologic and forensic science complement to the blood, urine, and tissues. It may be useful for the control of chloroquine therapy.

Chloroquine↗
PubMed1983

[Chemotherapy of extensive digestive cancers with 5-fluorouracil: relation between the clinical response and plasma clearance of the drug].

This study was designed to establish a possible relationship between the pharmacokinetics of 5-FU and response to treatment. Thirteen patients with advanced, histologically proven malignancies of the gastrointestinal tract were studied. 5-FU, at a single weekly dose of 15 mg/kg, was given in bolus or as an 8-h infusion to every patient. Plasma clearance of 5-FU after an i.v. bolus injection of 15 mg/kg was individually determined and found to vary widely among patients (from 0.39 to 2.55 l/min). A clearance greater than or equal to 0.86 l/min was seen in all the patients who did not respond to treatment. All patients (except one) with a partial response or a stable disease had a clearance less than or equal to 0.72 l/min. The mean clearance of non-responders (1.40 +/- 0.21 l/min) was significantly greater (P less than 0.02) than that of partial responders or patients with stable disease (0.73 +/- 0.15 l/min). These preliminary results deserve further investigation on a larger number of patients, before plasma levels of 5-FU may be accepted as an indication of response to chemotherapy.

Adult↗
PubMed1982

Determination of 7-amino-flunitrazepam (Ro 20-1815) and 7-amino-desmethylflunitrazepam (Ro 5-4650) in plasma by high-performance liquid chromatography and fluorescence detection.

A high-performance liquid chromatographic method for the simultaneous determination of 7-amino-flunitrazepam (Ro 20-1815) and 7-amino-desmethylflunitrazepam (Ro 5-4650) in plasma is described. After extraction with an organic solvent, the compounds and their internal standard (7-amino-methylclonazepam or Ro 5-3384) are derivatized with fluorescamine and chromatographed on a reversed-phase muBondapak C18 column using pH 8 buffer solution-acetonitrile (3:1) as mobile phase. The detection is performed by a fluorometer at excitation and emission wavelengths of 390 and 470 nm, respectively. The sensitivity limit is about 1 ng/ml of plasma for both 7-amino-flunitrazepam and 7-amino-desmethylflunitrazepam. The method has been applied to the determination of plasma levels of these substances during pharmacokinetic studies of flunitrazepam, desmethylflunitrazepam and 7-amino-flunitrazepam.

Animals↗
PubMed1982

A randomized trial of adjuvant chemotherapy and immunotherapy in cutaneous melanoma.

In a randomized trial of adjuvant chemotherapy, immunotherapy, or immunochemotherapy, 761 evaluable patients with pathological Stage II cutaneous melanoma anywhere on the body or with pathological Stage I melanoma of the trunk (Clark's level 3 to 5) were studied by the World Health Organization International Melanoma Group. Wide local excision and excisional regional lymphadenectomy alone were performed in 185 patients and the results were compared with those of surgery plus chemotherapy with dacarbazine (in 192 patients), surgery plus immunotherapy with bacille Calmette-Guérin vaccine (in 203), and surgery plus chemotherapy combined with immunotherapy (in 181). The rates of disease-free survival and overall survival at 36 months were 30.4 +/- 8.3 per cent (mean +/- S.E.) and 41.6 +/- 10.0 per cent, respectively, after surgical treatment alone; 37.2 +/- 7.9 per cent and 46.5 +/- 8.3 per cent after surgery plus chemotherapy; 34.8 +/- 7.9 per cent and 48.7 +/- 8.7 per cent after surgery plus immunotherapy; and 33.6 +/- 7.9 per cent and 50.0 +/- 8.8 per cent after surgery plus a combination of chemotherapy and immunotherapy. None of the differences between groups was significant, and thus no effect of adjuvant therapy could be demonstrated in this study.

BCG Vaccine↗