Trecovirsen, a 25-mer antisense phosphorothioate oligonucleotide targeted at the gag site of the ... more Trecovirsen, a 25-mer antisense phosphorothioate oligonucleotide targeted at the gag site of the HIV gene, was administered to HIV-positive volunteers as an IV infusion. Single doses ranged from 0.1 to 2.5 mg/kg in an ascending escalation in cohorts of 6 to 12 subjects. Plasma trecovirsen concentrations and pharmacokinetic parameters could be assessed at doses ≥0.3 mg/kg. Peak plasma concentrations and
Hypercholesterolemia increases the oxidation of low density lipoprotein (LDL) which subsequently ... more Hypercholesterolemia increases the oxidation of low density lipoprotein (LDL) which subsequently leads to atherogenesis. The oxidized LDL are also known to increase in vitro macrophage synthesis of glutathione. The purpose of this study was to investigate the relationship between lipid parameters and the glutathione system (glutathione, glutathione S-transferase) in total blood and within leukocytes. The glutathione and glutathione S-transferase were evaluated by spectrophotometric methods in sixty-two healthy volunteers (32 women, 30 men, mean age 39.9 +/- 7.7). No correlation was found between the level of blood cholesterol and the values of the blood glutathione system. However, a positive correlation between the values of glutathione and glutathione S-transferase in leukocytes and the blood cholesterol level was only found in women (r = 0.55 and r = 0.50 respectively, p < 0.01). We also found in men a positive correlation between body mass index and glutathione S-transferase in total blood and within leukocytes (r = 0.38, p < 0.05, r = 0.5, p < 0.01 respectively). No correlation was found between age, smoking and the values of the glutathione system. Our results suggest that the glutathione system in leukocytes is related to blood cholesterol levels. The fact that this positive correlation was only observed in women points to a possible role of estrogens in the regulation of the glutathione system which merits to be further studied.
Mass spectrometry has emerged as a powerful tool for studying the fate of drugs in living organis... more Mass spectrometry has emerged as a powerful tool for studying the fate of drugs in living organisms, especially when used in conjunction with new techniques of ionization, such as fast atom bombardment or the ion spray technique, and efficient detectors. New ionization techniques have led to the development of high performance liquid chromatography-mass spectrometry interfaces that combine the separation efficiency of HPLC and the power of mass spectrometry for determination of the molecular weight of complex macromolecules and identification of the structure of drugs and their biotransformation products.
Pharmacogenetics could be defined as the study of genetically controlled variations in drug respo... more Pharmacogenetics could be defined as the study of genetically controlled variations in drug response. Introduction of pharmacogenetics in hematology and oncology has been done recently. With recombinant DNA technology, like restriction analysis of genomic DNA, enzymatic amplification of DNA by the polymerase chain reaction and expression of cDNAs in cell cultures, this research area has been developed during the last 10 years. In hematology and oncology, we can integrate pharmacogenetics in 3 areas. First, the concept of genetic risk of cancer and the study of drug or carcinogen metabolizing enzymes that could modulate this risk, regarding the activity of some specific enzymes; second, the use of pharmacogenetics, related to the toxicity or efficacy of anticancer drugs, allowing the identification of key enzymes involved in the biotransformation of the drug and the study of molecular aspects involved in the regulation of the activity of the enzymes; third, the implication of the study of enzymatic activities in tumoral tissues as compared to non-tumoral tissues. The following differences between the 2 tissues can be subsequently used to increase the specificity of the anticancer drugs.
In a cancer patient given 100 mg/m2 elliptinium by intravenous infusion, the glutathione conjugat... more In a cancer patient given 100 mg/m2 elliptinium by intravenous infusion, the glutathione conjugate was found in urine. This metabolite was isolated after ion-exchange treatment and high performance liquid chromatography. Its structure was assessed by fast-atom bombardment mass spectrometry and comparison with an authentic sample.
New ellipticine derivatives of the 2-methyl ellipticinium (NME) series, i.e. 2,6-dimethylelliptic... more New ellipticine derivatives of the 2-methyl ellipticinium (NME) series, i.e. 2,6-dimethylellipticinium (6-Me-NME) and 2-methyl-6-n-propylellipticinium (6-Pr-NME), have been studied as cytotoxic compounds. Their uptake by NIH-3T3 cells and efflux have been measured by a sensitive and specific high performance liquid chromatographic assay. These compounds are equitoxic if we compare their cytotoxicity by two methods: growth inhibition and cloning efficiency. However, they accumulate in NIH-3T3 cells at different steady state levels and the efflux rates are not similar. This raises the question of the mode of action of these drugs.
Continuous intravenous infusion of chemotherapy is now widely used to enhance the therapeutic ind... more Continuous intravenous infusion of chemotherapy is now widely used to enhance the therapeutic index of cancer drugs. Cellular kinetics and pharmacological basis for protracted intravenous chemotherapy are reviewed for the main available drugs. From the increasingly published data it is now possible to separate routine and research utilization of protracted infusion chemotherapy.
L1210 leukemia was used to evaluate the antitumour activity in vivo of CY233 (NSC 609224) a new w... more L1210 leukemia was used to evaluate the antitumour activity in vivo of CY233 (NSC 609224) a new water-soluble nitrosoureido derivative of deoxysugar currently being studied in preclinical trials. The antitumour activity of CY233 is dose-dependent with the same large therapeutic index whatever the route of administration (I.P., I.V., per os). Thus starting from a single dose of 10 mg/kg (less than 25% of the LD50), 80% to 100% of mice survive at 120 days, whether the drug is being administered I.V., I.P. or P.O. These results clearly emphasize the very original and promising potentiality of CY233 among the series of alkylating agents, and more precisely nitrosoureas.
Radiolabeled 9-hydroxyellipticine (iv and ip routes) and the corresponding radioactive quaternary... more Radiolabeled 9-hydroxyellipticine (iv and ip routes) and the corresponding radioactive quaternary salt, 2-methyl-9-hydroxyellipticinium acetate (iv route), were administered to mice. Tissue distribution was then followed up to 64 hours by means of autoradiography. Both drugs accumulated in the kidneys, lungs, and liver; 9-hydroxyellipticine also accumulated in the spleen and bone marrow. The quaternary salt was concentrated in the gastrointestinal walls and the salivary and thyroid glands; none was found in the brain. Metabolic studies after administration of these antitumor drugs to rats and mice showed that 9-hydroxyellipticine is extensively metabolized, mainly to its glucuronide. Under our experimental conditions, the ellipticinium derivative was excreted unchanged in the bile (70%) and in the urine (30%). Pharmacokinetic studies in mice using either radioactivity measurements or selective extraction followed by spectrofluorometric quantitation have shown that blood levels drop very rapidly during the distribution phase followed by a much slower disposition phase, with a half-life of about 30 hours for the quaternary salt.
Using high-performance liquid chromatography, the stability of RFCNU was monitored as a function ... more Using high-performance liquid chromatography, the stability of RFCNU was monitored as a function of pH in aqueous buffers at 37 degrees C and as a function of temperature in plasma. The kinetics of degradation of RFCNU are apparently first-order. The log kappa-pH profile demonstrated the hydroxyl ion-catalyzed solvolysis and a maximum stability around pH 3.0. This analytic assay was reliable for quantitating intact RFCNU in biologic fluids. After administration of 400 mg of RFCNU orally to a female patient, no intact drug was excreted in the urine and plasma levels were very low.
UK PubMed Central is a service of the UKPMC Funders Group working in partnership with the British... more UK PubMed Central is a service of the UKPMC Funders Group working in partnership with the British Library, University of Manchester and the European Bioinformatics Institute in cooperation with the National Center for Biotechnology Information at the US National ...
A program for the HP-41C calculator allows the determination of the first three statistical momen... more A program for the HP-41C calculator allows the determination of the first three statistical moments, area under the curve (moment zero), mean residence time (first moment) and variance of residence time (second moment) of drug concentration-time curves which are used for noncompartmental pharmacokinetic analyses. Applications of this theory are given.
After in vitro tests, a tracer dose of cisplatin was administered to an anuric cancer patient. Pl... more After in vitro tests, a tracer dose of cisplatin was administered to an anuric cancer patient. Plasma total platinum levels were monitored as a function of time, as was filterable platinum elimination by hemofiltration dialysis. Based on the derived pharmacokinetic parameters, the patient was later given 50-mg doses of cisplatin, once as a single agent, then four times in combination with doxorubicin, VM-26, and cyclophosphamide. Plasma levels could be fitted by a sum of three exponentials after the infusion was stopped. The mean corresponding half-lives are 30 minutes, 6 hours, and 5 days. Depending on the rate of infusion, plasma peaks ranged between 1.1 micrograms/ml (5.7 X 10(-6) M) and 2.27 micrograms/ml (1.16 X 10(-5) M). During the hemofiltration process immediately following the infusion, the elimination rate was first-order, with a mean half-life of 60 minutes. The mean amount eliminated during the first hemofiltration session was 8% of the dose, decreasing to about 3% on Days 2 and 3. A partial tumor response was observed after two treatment courses, evidenced by the relief of abdominal pain and bowel obstruction episodes and a 50% decrease in peritoneal metastases.
In an attempt to better understand breast tumors sensitivity or resistance to anticancer drugs, t... more In an attempt to better understand breast tumors sensitivity or resistance to anticancer drugs, the main drug-metabolizing enzyme systems were evaluated in both breast tumors and their corresponding peritumoral tissues in 12 patients. The following enzymes were assayed by Western blot: cytochromes P-450 (1A1/A2, 2B1/B2, 2C8-10, 2E1, 3A4); glutathione S-transferases (GST-alpha, -mu, and -pi); and epoxide hydrolase. The activity of the following enzymes or cofactor were determined by spectrophotometric or fluorometric assays: GST; total glutathione; UDP-glucuronosyltransferase; beta-glucuronidase; sulfotransferase; and sulfatase. Results showed the absence of all probed cytochromes P-450 in both tumoral and peritumoral tissues. GST activity was significantly (P < 0.05) higher in tumors (mean +/- SD, 399 +/- 362 nmol/min/mg) than in corresponding peritumoral tissues (86 +/- 67). The GST isoenzymes GST-mu and GST-pi (determined by immunoblotting) were also higher in tumors than in corresponding peritumoral tissues (3- and 5-fold, respectively). Both GST-mu and GST-pi levels were significantly correlated with GST activity. GST-alpha was not detected in either tumoral or peritumoral tissues. Glutathione levels in tumors (22 +/- 23 nmol/mg protein) were not statistically different from peritumoral tissues (11 +/- 12). Epoxide hydrolase was expressed at similar levels in tumors and peritumoral tissues. The glucuronide-forming enzyme UDP-glucuronosyltransferase was 5-fold lower in tumors (0.1 +/- 0.2 nmol/h/mg) than in peritumoral tissues (0.5 +/- 1), whereas the opposite was observed for the hydrolytic enzyme beta-glucuronidase, which was 6-fold higher in tumors (736 +/- 1392 nmol/h/mg) compared to peritumoral tissues (125 +/- 75). No difference was noted between tumoral and peritumoral tissues for sulfotransferase (1 +/- 2 nmol/h/mg), but the corresponding hydrolytic enzyme (sulfatase) was 2-fold higher in tumoral tissues (14 +/- 15 nmol/h/mg) than in peritumoral tissues (6 +/- 2). In conclusion, several differences were observed between human breast tumors and peritumoral tissues for many conjugating enzymes (GST-mu, GST-pi, and UDP-glucuronosyltransferase) and hydrolytic enzymes (sulfatase and beta-glucuronidase). These noteworthy differences between tumoral and peritumoral tissues with regard to their main drug-metabolizing enzymes could play a role in the relative drug sensitivity or insensitivity of human breast cancer tissues to chemotherapeutic agents and could be potential targets for chemotherapeutic interventions.
Trecovirsen, a 25-mer antisense phosphorothioate oligonucleotide targeted at the gag site of the ... more Trecovirsen, a 25-mer antisense phosphorothioate oligonucleotide targeted at the gag site of the HIV gene, was administered to HIV-positive volunteers as an IV infusion. Single doses ranged from 0.1 to 2.5 mg/kg in an ascending escalation in cohorts of 6 to 12 subjects. Plasma trecovirsen concentrations and pharmacokinetic parameters could be assessed at doses ≥0.3 mg/kg. Peak plasma concentrations and
Hypercholesterolemia increases the oxidation of low density lipoprotein (LDL) which subsequently ... more Hypercholesterolemia increases the oxidation of low density lipoprotein (LDL) which subsequently leads to atherogenesis. The oxidized LDL are also known to increase in vitro macrophage synthesis of glutathione. The purpose of this study was to investigate the relationship between lipid parameters and the glutathione system (glutathione, glutathione S-transferase) in total blood and within leukocytes. The glutathione and glutathione S-transferase were evaluated by spectrophotometric methods in sixty-two healthy volunteers (32 women, 30 men, mean age 39.9 +/- 7.7). No correlation was found between the level of blood cholesterol and the values of the blood glutathione system. However, a positive correlation between the values of glutathione and glutathione S-transferase in leukocytes and the blood cholesterol level was only found in women (r = 0.55 and r = 0.50 respectively, p < 0.01). We also found in men a positive correlation between body mass index and glutathione S-transferase in total blood and within leukocytes (r = 0.38, p < 0.05, r = 0.5, p < 0.01 respectively). No correlation was found between age, smoking and the values of the glutathione system. Our results suggest that the glutathione system in leukocytes is related to blood cholesterol levels. The fact that this positive correlation was only observed in women points to a possible role of estrogens in the regulation of the glutathione system which merits to be further studied.
Mass spectrometry has emerged as a powerful tool for studying the fate of drugs in living organis... more Mass spectrometry has emerged as a powerful tool for studying the fate of drugs in living organisms, especially when used in conjunction with new techniques of ionization, such as fast atom bombardment or the ion spray technique, and efficient detectors. New ionization techniques have led to the development of high performance liquid chromatography-mass spectrometry interfaces that combine the separation efficiency of HPLC and the power of mass spectrometry for determination of the molecular weight of complex macromolecules and identification of the structure of drugs and their biotransformation products.
Pharmacogenetics could be defined as the study of genetically controlled variations in drug respo... more Pharmacogenetics could be defined as the study of genetically controlled variations in drug response. Introduction of pharmacogenetics in hematology and oncology has been done recently. With recombinant DNA technology, like restriction analysis of genomic DNA, enzymatic amplification of DNA by the polymerase chain reaction and expression of cDNAs in cell cultures, this research area has been developed during the last 10 years. In hematology and oncology, we can integrate pharmacogenetics in 3 areas. First, the concept of genetic risk of cancer and the study of drug or carcinogen metabolizing enzymes that could modulate this risk, regarding the activity of some specific enzymes; second, the use of pharmacogenetics, related to the toxicity or efficacy of anticancer drugs, allowing the identification of key enzymes involved in the biotransformation of the drug and the study of molecular aspects involved in the regulation of the activity of the enzymes; third, the implication of the study of enzymatic activities in tumoral tissues as compared to non-tumoral tissues. The following differences between the 2 tissues can be subsequently used to increase the specificity of the anticancer drugs.
In a cancer patient given 100 mg/m2 elliptinium by intravenous infusion, the glutathione conjugat... more In a cancer patient given 100 mg/m2 elliptinium by intravenous infusion, the glutathione conjugate was found in urine. This metabolite was isolated after ion-exchange treatment and high performance liquid chromatography. Its structure was assessed by fast-atom bombardment mass spectrometry and comparison with an authentic sample.
New ellipticine derivatives of the 2-methyl ellipticinium (NME) series, i.e. 2,6-dimethylelliptic... more New ellipticine derivatives of the 2-methyl ellipticinium (NME) series, i.e. 2,6-dimethylellipticinium (6-Me-NME) and 2-methyl-6-n-propylellipticinium (6-Pr-NME), have been studied as cytotoxic compounds. Their uptake by NIH-3T3 cells and efflux have been measured by a sensitive and specific high performance liquid chromatographic assay. These compounds are equitoxic if we compare their cytotoxicity by two methods: growth inhibition and cloning efficiency. However, they accumulate in NIH-3T3 cells at different steady state levels and the efflux rates are not similar. This raises the question of the mode of action of these drugs.
Continuous intravenous infusion of chemotherapy is now widely used to enhance the therapeutic ind... more Continuous intravenous infusion of chemotherapy is now widely used to enhance the therapeutic index of cancer drugs. Cellular kinetics and pharmacological basis for protracted intravenous chemotherapy are reviewed for the main available drugs. From the increasingly published data it is now possible to separate routine and research utilization of protracted infusion chemotherapy.
L1210 leukemia was used to evaluate the antitumour activity in vivo of CY233 (NSC 609224) a new w... more L1210 leukemia was used to evaluate the antitumour activity in vivo of CY233 (NSC 609224) a new water-soluble nitrosoureido derivative of deoxysugar currently being studied in preclinical trials. The antitumour activity of CY233 is dose-dependent with the same large therapeutic index whatever the route of administration (I.P., I.V., per os). Thus starting from a single dose of 10 mg/kg (less than 25% of the LD50), 80% to 100% of mice survive at 120 days, whether the drug is being administered I.V., I.P. or P.O. These results clearly emphasize the very original and promising potentiality of CY233 among the series of alkylating agents, and more precisely nitrosoureas.
Radiolabeled 9-hydroxyellipticine (iv and ip routes) and the corresponding radioactive quaternary... more Radiolabeled 9-hydroxyellipticine (iv and ip routes) and the corresponding radioactive quaternary salt, 2-methyl-9-hydroxyellipticinium acetate (iv route), were administered to mice. Tissue distribution was then followed up to 64 hours by means of autoradiography. Both drugs accumulated in the kidneys, lungs, and liver; 9-hydroxyellipticine also accumulated in the spleen and bone marrow. The quaternary salt was concentrated in the gastrointestinal walls and the salivary and thyroid glands; none was found in the brain. Metabolic studies after administration of these antitumor drugs to rats and mice showed that 9-hydroxyellipticine is extensively metabolized, mainly to its glucuronide. Under our experimental conditions, the ellipticinium derivative was excreted unchanged in the bile (70%) and in the urine (30%). Pharmacokinetic studies in mice using either radioactivity measurements or selective extraction followed by spectrofluorometric quantitation have shown that blood levels drop very rapidly during the distribution phase followed by a much slower disposition phase, with a half-life of about 30 hours for the quaternary salt.
Using high-performance liquid chromatography, the stability of RFCNU was monitored as a function ... more Using high-performance liquid chromatography, the stability of RFCNU was monitored as a function of pH in aqueous buffers at 37 degrees C and as a function of temperature in plasma. The kinetics of degradation of RFCNU are apparently first-order. The log kappa-pH profile demonstrated the hydroxyl ion-catalyzed solvolysis and a maximum stability around pH 3.0. This analytic assay was reliable for quantitating intact RFCNU in biologic fluids. After administration of 400 mg of RFCNU orally to a female patient, no intact drug was excreted in the urine and plasma levels were very low.
UK PubMed Central is a service of the UKPMC Funders Group working in partnership with the British... more UK PubMed Central is a service of the UKPMC Funders Group working in partnership with the British Library, University of Manchester and the European Bioinformatics Institute in cooperation with the National Center for Biotechnology Information at the US National ...
A program for the HP-41C calculator allows the determination of the first three statistical momen... more A program for the HP-41C calculator allows the determination of the first three statistical moments, area under the curve (moment zero), mean residence time (first moment) and variance of residence time (second moment) of drug concentration-time curves which are used for noncompartmental pharmacokinetic analyses. Applications of this theory are given.
After in vitro tests, a tracer dose of cisplatin was administered to an anuric cancer patient. Pl... more After in vitro tests, a tracer dose of cisplatin was administered to an anuric cancer patient. Plasma total platinum levels were monitored as a function of time, as was filterable platinum elimination by hemofiltration dialysis. Based on the derived pharmacokinetic parameters, the patient was later given 50-mg doses of cisplatin, once as a single agent, then four times in combination with doxorubicin, VM-26, and cyclophosphamide. Plasma levels could be fitted by a sum of three exponentials after the infusion was stopped. The mean corresponding half-lives are 30 minutes, 6 hours, and 5 days. Depending on the rate of infusion, plasma peaks ranged between 1.1 micrograms/ml (5.7 X 10(-6) M) and 2.27 micrograms/ml (1.16 X 10(-5) M). During the hemofiltration process immediately following the infusion, the elimination rate was first-order, with a mean half-life of 60 minutes. The mean amount eliminated during the first hemofiltration session was 8% of the dose, decreasing to about 3% on Days 2 and 3. A partial tumor response was observed after two treatment courses, evidenced by the relief of abdominal pain and bowel obstruction episodes and a 50% decrease in peritoneal metastases.
In an attempt to better understand breast tumors sensitivity or resistance to anticancer drugs, t... more In an attempt to better understand breast tumors sensitivity or resistance to anticancer drugs, the main drug-metabolizing enzyme systems were evaluated in both breast tumors and their corresponding peritumoral tissues in 12 patients. The following enzymes were assayed by Western blot: cytochromes P-450 (1A1/A2, 2B1/B2, 2C8-10, 2E1, 3A4); glutathione S-transferases (GST-alpha, -mu, and -pi); and epoxide hydrolase. The activity of the following enzymes or cofactor were determined by spectrophotometric or fluorometric assays: GST; total glutathione; UDP-glucuronosyltransferase; beta-glucuronidase; sulfotransferase; and sulfatase. Results showed the absence of all probed cytochromes P-450 in both tumoral and peritumoral tissues. GST activity was significantly (P < 0.05) higher in tumors (mean +/- SD, 399 +/- 362 nmol/min/mg) than in corresponding peritumoral tissues (86 +/- 67). The GST isoenzymes GST-mu and GST-pi (determined by immunoblotting) were also higher in tumors than in corresponding peritumoral tissues (3- and 5-fold, respectively). Both GST-mu and GST-pi levels were significantly correlated with GST activity. GST-alpha was not detected in either tumoral or peritumoral tissues. Glutathione levels in tumors (22 +/- 23 nmol/mg protein) were not statistically different from peritumoral tissues (11 +/- 12). Epoxide hydrolase was expressed at similar levels in tumors and peritumoral tissues. The glucuronide-forming enzyme UDP-glucuronosyltransferase was 5-fold lower in tumors (0.1 +/- 0.2 nmol/h/mg) than in peritumoral tissues (0.5 +/- 1), whereas the opposite was observed for the hydrolytic enzyme beta-glucuronidase, which was 6-fold higher in tumors (736 +/- 1392 nmol/h/mg) compared to peritumoral tissues (125 +/- 75). No difference was noted between tumoral and peritumoral tissues for sulfotransferase (1 +/- 2 nmol/h/mg), but the corresponding hydrolytic enzyme (sulfatase) was 2-fold higher in tumoral tissues (14 +/- 15 nmol/h/mg) than in peritumoral tissues (6 +/- 2). In conclusion, several differences were observed between human breast tumors and peritumoral tissues for many conjugating enzymes (GST-mu, GST-pi, and UDP-glucuronosyltransferase) and hydrolytic enzymes (sulfatase and beta-glucuronidase). These noteworthy differences between tumoral and peritumoral tissues with regard to their main drug-metabolizing enzymes could play a role in the relative drug sensitivity or insensitivity of human breast cancer tissues to chemotherapeutic agents and could be potential targets for chemotherapeutic interventions.
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