Sinusoidal phase modulating (SPM) interferometers are used to precisely measure complex light fields with simple interferometric setups. Recently, a generalized lock-in technique has been proposed for optimizing the signal extraction in phase-modulated interferometers. This article shows its applicability in digital holography as well as digital holographic interferometry.
View Article and Find Full Text PDFMetal-insulator-metal systems exhibit a rich underlying physics leading to a high degree of tunability of their spectral properties. We performed a systematic study on a metal-insulator-nanostructured metal system with a thin 6 nm dielectric spacer and showed how the nanoparticle sizes and excitation conditions lead to the tunability and coupling/decoupling of localized and delocalized plasmonic modes. We also experimentally evidenced a tunable Fano resonance in a broad spectral window 600 to 800 nm resulting from the interference of gap modes with white light broad band transmitted waves at the interface playing the role of the continuum.
View Article and Find Full Text PDFClin Pharmacokinet
December 2005
Telithromycin is the first ketolide, which is a new class of antibacterial agents related to the macrolides that have structural modifications permitting dual binding to bacterial ribosomal RNA so that activity is retained against Streptococcus pneumoniae with macrolide-lincosamide-streptogramin(B) resistance. Clinical experience in infectious patients has shown that oral telithromycin 800mg once daily for 5-10 days is effective for the treatment of community-acquired upper and lower respiratory tract infections. Absorption of telithromycin in humans is estimated to be > or = 90%.
View Article and Find Full Text PDFObjective: The objective of this study was to determine the effect of multiple impairments in drug elimination on the pharmacokinetics and pharmacodynamics (effect on QTc interval), using clarithromycin as a comparator.
Methods: Thirty-two subjects aged > or = 60 years with renal impairment who were otherwise medically stable were recruited into this parallel-group study. Following stratification according to creatinine clearance (CL(CR)), subjects were randomized to a five-day treatment with ketoconazole (400 mg once daily) alone, or a five-day treatment with ketoconazole (400 mg once daily) and telithromycin (800 mg once daily) given concomitantly or a five-day treatment with ketoconazole (400 mg once daily) and clarithromycin (500 mg twice daily) given concomitantly.
Study Objective: To determine whether coadministration of the cytochrome P450 3A4 (CYP3A4) inhibitors itraconazole or grapefruit juice will modify the pharmacokinetic profile of telithromycin, and to assess the safety of telithromycin.
Design: Two single-center, open-label studies; the itraconazole study was nonrandomized, sequential, and multiple dose, and the grapefruit juice study was randomized, two-period crossover, and single dose.
Setting: Two clinical investigative centers in the United States.
The pharmacokinetics and safety of the ketolide telithromycin were evaluated in two separate studies after single and repeat oral dosing in patients with varying degrees of renal impairment and in subjects with normal renal function. The single-dose study was an open-label, nonrandomized, parallel-group design in which all 40 patients received a single oral dose of telithromycin 800 mg. The repeat-dose study was an open-label study with a randomized, balanced, incomplete three-block treatment crossover design.
View Article and Find Full Text PDFThe pharmacokinetic profiles of single and repeated oral doses of telithromycin 800 mg/day were compared in patients with hepatic impairment and healthy subjects in two open-label, non-randomized, parallel-group, multicentre studies. The maximal plasma concentrations (Cmax) and the area under the plasma concentration-time (AUC) curves for telithromycin were similar in hepatically impaired patients and healthy subjects in the single- and repeated-dose studies. The extent of formation of RU 76363, the major circulating metabolite of telithromycin, was decreased following single and repeated doses in patients with hepatic impairment compared with healthy subjects.
View Article and Find Full Text PDFTelithromycin is an innovative antibacterial designed for the treatment of community-acquired respiratory tract infections. This study assessed the effect of food on the bioavailability of a single oral dose of telithromycin 800 mg in healthy male subjects. Male volunteers aged 18-45 y were recruited for an open-label, single-dose, 2-period, cross-over study.
View Article and Find Full Text PDFBackground: This two-way, randomized, single-dose, crossover study determined the pharmacokinetics and absolute oral bioavailability of telithromycin in young and elderly healthy subjects.
Methods: Twelve young (18-40 years) and 12 elderly (>65 years and =85 years) subjects received a single 800-mg oral dose of telithromycin or an intravenous infusion of 400 mg (young subjects) or 480 mg (elderly subjects) of telithromycin over 2.5 h in two treatment periods, separated by a 1-week washout period.
Clin Pharmacol Ther
September 2002
Objectives: The objective of this study was to compare the pharmacokinetics of the low-molecular-weight heparin enoxaparin in obese and nonobese volunteers, by means of two administration regimens.
Methods: Enoxaparin was administered subcutaneously (1.5 mg/kg once daily for 4 days) and in a single 6-hour infusion (1.
Carbonated hydroxyapatite (CHA) coatings on a titanium alloy were prepared by hydrothermal synthesis of precursors plasma-sprayed with brushite as a raw powder. The structures, residual stresses, and bond strengths of the precursors and CHA coatings were investigated. The results showed that the sprayed precursors consisted of beta-Ca(2)P(2)O(7), alpha-Ca(3)(PO(4))(2), and CaHPO(4), whereas the CHA coatings exhibited a unique phase construction, nanostructured and needle-like crystals, and a fairly low tensile residual stress.
View Article and Find Full Text PDFThe population approach has been implemented prospectively in the clinical development of docetaxel (Taxotere). Overall 640 patients were evaluable for the population PK/PD analysis. The PK analysis evidenced significant covariates explaining the inter-patient variability of docetaxel clearance and the PK/PD analysis demonstrated that the variability in clearance was a significant predictor of several safety endpoints.
View Article and Find Full Text PDFQuinupristin/dalfopristin (Q/D) is a novel streptogramin antibiotic for the treatment of severe gram-positive infections. The purpose of this open, nonrandomized, parallel-group, phase I trial was to evaluate Q/D pharmacokinetics after single and repeated doses under the two different dosing regimens corresponding to the effective doses and to evaluate tolerability. Two groups of 10 healthy volunteers received multiple 1-hour intravenous infusions of 7.
View Article and Find Full Text PDFObjective: To compare the pharmacokinetic profile of a single intravenous injection of quinupristin/dalfopristin, a new injectable streptogramin, in healthy young individuals and patients with severe chronic renal insufficiency. A secondary objective was to assess the relative tolerability of this dose in these patients compared with healthy individuals.
Patients And Participants: 13 patients with severe chronic renal insufficiency (creatinine clearance 6 to 28 ml/min/1.
Ketoprofen is a nonsteroidal anti-inflammatory drug with analgesic, anti-inflammatory, and antipyretic properties. Its pharmacokinetics has not been determined in small children. The objective here was to determine the pharmacokinetics of ketoprofen syrup, 0.
View Article and Find Full Text PDFThe pharmacokinetics and tolerability of the novel antiexcitatory agent, riluzole, were compared in 18 healthy elderly and 18 healthy gender- and weight-matched young volunteers. All participants received riluzole 50 mg twice daily (the recommended dosage for patients with amyotrophic lateral sclerosis), administered orally for 5 days. The pharmacokinetics of riluzole, determined on the morning of the 5th day of dosing, were not significantly affected by age or gender.
View Article and Find Full Text PDFCPT-11 (irinotecan) and mainly its metabolite SN-38 are potent antitumor derivatives of camptothecin. As the active lactone forms of both CPT-11 and SN-38 exist in pH-dependent equilibrium with their respective less potent open-ring hydroxy acid species, the simultaneous monitoring of both forms of both compounds is relevant. CPT-11 and SN-38 derivatives have quite different fluorescence responses.
View Article and Find Full Text PDFClin Cancer Res
September 1997
Docetaxel activity has been documented in many solid tumors, including metastatic breast cancer and non-small cell lung cancer. However, as clinical studies in other tumor types are now being conducted, the validation of an optimal sampling strategy would allow the performance of pharmacokinetics/pharmacodynamics studies with minimum inconvenience for the patient. Six optimal sampling strategies with one to six sampling times were computed, based on the D-optimality theory, using population pharmacokinetic parameters estimated from a large pharmacokinetic database of 547 patients treated in previous Phase II studies.
View Article and Find Full Text PDFJ Chromatogr B Biomed Sci Appl
April 1998
Quinupristin-dalfopristin (30:70, w/w) is a new streptogramin, which has been developed for intravenous use. A specific and sensitive HPLC method was developed to measure simultaneously quinupristin (RP 57669) and dalfopristin (RP 54476) and their main metabolites in human plasma. The metabolites measured by this method were RP 69012 (glutathione-conjugated) and RPR 100391 (cysteine-conjugated) from quinupristin and RP 12536 (natural pristinamycin IIA), from dalfopristin.
View Article and Find Full Text PDFJ Clin Pharmacol
September 1997
Riluzole is a novel neuroprotective agent that has been developed for the treatment of amyotrophic lateral sclerosis. A series of studies was undertaken to establish its pharmacokinetics on single- and multiple-dose administration in young white male volunteers. The mean absolute oral bioavailability of riluzole (50-mg tablet) was approximately 60%.
View Article and Find Full Text PDFClin Pharmacol Ther
November 1997
Objectives: To characterize the population pharmacokinetic of riluzole in patients with amyotrophic lateral sclerosis (ALS).
Methods: One hundred patients with ALS who were participating in a multicenter phase III dose-ranging trial of riluzole were sampled on 179 visits. The sampling strategy (two samples per visit) was varied across patients to define the population kinetic profile (full screen).
J Antimicrob Chemother
May 1997
The pharmacokinetics of quinupristin/dalfopristin have been studied in rats, monkeys and humans following intravenous infusion of radiolabelled and unlabelled drug. In rats and monkeys quinupristin and dalfopristin undergo rapid elimination from the blood and wide tissue distribution. Nevertheless, they do not penetrate the central nervous system or cross the placenta to any significant degree and they do not appear to be subject to significant body retention following cessation of administration.
View Article and Find Full Text PDFJ Antimicrob Chemother
May 1996
In Caucasian volunteers and patients plasma sparfloxacin concentrations reached a peak of 1.2-1.5 mg/L between 3 and 6 h after a single 400 mg dose; T1/2 ranged from 16 to 22 h.
View Article and Find Full Text PDFJ Pharmacokinet Biopharm
April 1996
A sparse sampling strategy (3 samples per patient, 521 patients) was implemented in 22 Phase 2 studies of docetaxel (Taxotere) at the first treatment cycle for a prospective population pharmacokinetic evaluation. In addition to the 521 Phase 2 patients, 26 (data rich) patients from Phase I studies were included in the analysis. NONMEM analysis of an index set of 280 patients demonstrated that docetaxel clearance (CL) is related to alpha 1-acid glycoprotein (AAG) level, hepatic function (HEP), age (AGE), and body surface area (BSA).
View Article and Find Full Text PDFThe binding of docetaxel to human plasma proteins was studied by ultrafiltration at 37 degrees C and pH 7.4. Docetaxel was extensively (> 98%) plasma protein bound.
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