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C Lucarelli

Publications and source records attributed to C Lucarelli.

45 records · Page 3Linked to original sources
PubMed1988

Improved high-performance liquid chromatographic analysis with double detection system for L-dopa, its metabolites and carbidopa in plasma of parkinsonian patients under L-dopa therapy.

An analytical method is described for measuring L-3,4-dihydroxyphenylalanine (L-DOPA), 3-O-methyl-DOPA, dihydroxyphenylacetic acid, free catecholamines and the peripheral DOPA decarboxylase inhibitor, carbidopa, in plasma samples of Parkinsonian patients by using high-performance liquid chromatography. A sample preparation method is presented for the isolation of the catecholamines and L-DOPA with its metabolites. Catecholamines are extracted by weak cation exchange on small columns and subsequent adsorption on alumina. L-DOPA, 3-O-methyl-DOPA, dihydroxyphenylacetic acid and carbidopa contained in the column effluents are directly injected in the chromatographic system. The eluates are separated on a reversed-phase column, monitored by both a coulometric electrochemical detector and a fluorescence detector, connected in series. Chromatographic peaks were identified on the basis of their retentions and response ratios of the two detectors. Two examples are presented of therapeutic drug monitoring in Parkinsonian patients treated with oral doses and continuous intravenous infusion of L-DOPA.

Carbidopa↗
PubMedDate not supplied

High performance liquid chromatographic strategy for the analysis of exopolysaccharides extracted from pathogenic bacteria.

A high performance liquid chromatographic (HPLC) method has been developed to permit the rapid comparison of acidic polysaccharides of diverse compositions and the sensitive determination of their constituents. It is based on two combined analyses of the polysaccharide hydrolysates--a separation of the released compounds by ion-moderated partition chromatography with UV detection at two wavelengths and a separation of the sugar dansylhydrazine derivatives by reversed phase chromatography. The former permits identification and quantitation of uronic and carboxylic acids, the latter permits more sensitive and specific determination of the neutral aldoses. Some bacterial exopolysaccharides have been used to demonstrate the validity of this HPLC procedure for the chemical characterization of uronic acid-containing polysaccharides. This method appears to be useful for studying capsular polysaccharides, which are involved in the evasion of phagocytosis by pathogenic bacteria.

Carboxylic Acids↗
PubMedDate not supplied

Pharmacokinetics of cefodizime in patients with various degrees of renal failure.

The pharmacokinetics of cefodizime, a new expanded-spectrum cephalosporin for parenteral use, was studied in 45 subjects with various degrees of renal failure. Patients were divided into five groups according to the following creatinine clearances: group I >80 ml/min; group II <80-30 ml/min; group III <30-15 ml/min; group IV <15-5 ml/min and group V <5 ml/min. Cefodizime was administered as a 1 g i.v. bolus. Plasma and urinary concentrations of cefodizime were determined by high-performance liquid chromatography, using for detection UV absorbance. The following pharmacokinetic parameters were calculated: maximum plasma concentration (C5 min), area under the plasma concentration-time curve (AUC), terminal half-life (T1/2), terminal rate constant (lambda-z), total clearance (Clt), volume of distribution (Vd), mean residence time (MRT), urine data-derived terminal half-life (T1/2 r), renal clearance (Clr). The results of this study showed that renal failure induced changes in cefodizime pharmacokinetics. Our data demonstrated a close correlation between degree of renal impairment and pharmacokinetic changes. The maximum plasma concentration (C5 min) was higher in patients with renal failure; T1/2 was increased; AUC also increased from 470.40 +/- 17.80 mg.h/l in the control group to 1,562.30 +/- 170.8 mg.h/l in group V. Moreover, no side effect was observed after treatment with 1 g i.v. of cefodizime. Although renal failure induces significant changes of cefodizime pharmacokinetics, the drug was well tolerated and only in patients with severe renal insufficiency we advise to monitor the interval dose of cefodizime or adjust doses to renal function.

Adolescent↗