Biomedical subjects

C Mannucci

Publications and source records attributed to C Mannucci.

16 recordsLinked to original sources

PubMed2006

Enzymatic urea adaptation: lactate and malate dehydrogenase in elasmobranchs.

Lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) electrophoretic tissue patterns of two different orders of Elasmobranchii: Carchariniformes (Galeus melanostomus and Prionace glauca) and Squaliformes (Etmopterus spinax and Scymnorinus licha) were studied. The number of loci expressed for these enzymes was the same of other elasmobranch species. Differences in tissue distribution were noted in LDH from G. melanostomus due to the presence of an additional heterotetramer in the eye tissue. There were also differences in MDH. In fact, all the tissues of E. spinax and G. melanostomus showed two mitochondrial bands. Major differences were noted in the number of isozymes detected in the four compared elasmobranchs. The highest polymorphism was observed in E. spinax and G. melanostomus, two species that live in changeable environmental conditions. The resistance of isozymes after urea treatment was examined; the resulting patterns showed a quite good resistance of the enzymes, higher for LDH than MDH, also at urea concentration much greater than physiological one. These results indicated that the total isozyme resistance can be considered higher in urea accumulators (such as elasmobranchs) than in the non-accumulators (such as teleosts).

Adaptation, Physiological↗

PubMed1994

Synthesis, characterization, and analytical studies of adosupine, a potential new drug for urinary incontinence.

The synthesis and the spectroscopic characterization of a new potential drug for urinary incontinence, adosupine, is described. Adosupine and its potential synthesis impurities were analyzed by a new HPLC method that was developed with a C18 reversed-phase column. The analysis was made under isocratic conditions, with a mobile phase of acetonitrile:water (15:85, v/v). Resolution of all synthesis impurities was allowed. The method was also applied to stability studies of adosupine in solid state and in solution under different conditions. With the conditions used, only one degradation product was shown by HPLC analysis; it was isolated, characterized, and identified as the hydrolysis product of the lactam ring present in the adosupine structure.

Chromatography, High Pressure Liquid↗

PubMed1993

Rapid simultaneous determination of tryptophan and tyrosine in synthetic peptides by derivative spectroscopy.

A method for the simultaneous quantitative determination of tryptophan and tyrosine in synthetic peptides by second-order derivative diode-array spectroscopy is reported. The method does not require hydrolysis of the peptides or a derivatization reaction; the sample is dissolved in 0.1 N NaOH and directly scanned between 262 and 264 nm to detect tyrosine and between 304 and 306 nm to detect tryptophan. From these results the peptide content of the synthetic sample can be easily calculated in a very simple and fast way. The results obtained by the described method with several peptides are compared with those obtained by classical high-performance liquid chromatographic analysis of amino acids after peptide hydrolysis. A very good correlation was found both for the tryptophan/tyrosine molar ratio and the peptide content.

Amino Acid Sequence↗

PubMed1993

High-performance liquid chromatographic method for assay of otilonium bromide, diazepam, and related compounds in finished pharmaceutical forms.

A rapid, simple, stability-indicating assay procedure for otilonium bromide, a smooth muscle relaxant agent, and diazepam in composite tablet analysis was developed with high-performance liquid chromatography. The tablet matrix was dissolved with water, and drugs were extracted with acetonitrile containing an internal standard. An aliquot was centrifuged and chromatographed on a 5-microns, reversed-phase column with 0.5 M sodium acetate trihydrate buffer containing 5 mM 1-heptanesulfonic acid monohydrate sodium salt:methanol (30:70; v/v; adjusted to pH 6.0 with glacial acetic acid) as the mobile phase. The selectivity of the chromatographic system was demonstrated by resolving both compounds from various potential degradation products of each compound. The method is linear, quantitative, and reproducible.

Chromatography, High Pressure Liquid↗

PubMed1992

High-performance liquid chromatographic method for determination of ronactolol in urine and plasma: evaluation of pharmacokinetic parameters in healthy humans.

Ronactolol [(+/-)-4'-[2-hydroxy-3-(isopropylamino)propoxy]-p-anisanilide], a new aminopropanol derivative showing beta-adrenoreceptor blocking activity, was administered orally as capsules to healthy humans at three single doses (30, 60, and 120 mg). Two HPLC methods were developed separately for determination of drug levels in urine and plasma. For plasma samples, after addition of internal standard (IS), a single-step extraction of alkalinized plasma was performed with methylene chloride. The organic layer was evaporated to dryness under reduced pressure, and the residue was taken up and chromatographed on a microbore silica column. Ronactolol and IS were detected by a UV detector at a wavelength of 278 nm. Excellent linearity was observed between the peak height ratios (ronactolol:IS) and concentrations in plasma. The lowest limit of detection (signal:noise, 3:1) was 1.5 ng/mL of plasma. Urine samples were directly injected and chromatographed on a microbore C18 column with an ion-pairing mobile phase. Excellent linearity was observed between the peak areas and concentrations in urine. The lowest limit of detection (signal:noise, 3:1) was 75 ng/mL of urine. The assay was used to determine the main pharmacokinetic parameters in healthy humans.

Adrenergic beta-Antagonists↗

PubMed1992

Simultaneous determination of otilonium bromide and diazepam by first-derivative spectroscopy.

A rapid, simple assay procedure was developed for simultaneous analysis of otilonium bromide, a smooth-muscle relaxant, and diazepam in tablets containing 20 mg of otilonium bromide and 2 mg of diazepam (20:2 tablets) or 40 mg of otilonium bromide and 2 mg of diazepam (40:2 tablets) by "zero-crossing" first-derivative spectroscopy. The tablets were dissolved in 0.01 N HCl, mixtures were centrifuged at 3500 rpm (2472 x g) for 5 min, and first-derivative spectra were recorded. The absolute values of the derivative were measured at 264 nm for determination of otilonium bromide and between 406 and 408 nm (380 nm for analysis of 40:2 tablets) for determination of diazepam. The method is linear, quantitative, and reproducible and can also be used for the tablet dissolution test. Ten tablets of the same batch were analyzed by the described method and by a high-performance liquid chromatographic method, and the results were in good agreement.

Calibration↗

PubMed1991

Analysis of platelet-activating factor by gas chromatography-mass spectrometry: low-energy electron impact of the corresponding 3-acetyl-2-tert.-butyldimethylsilyl derivative.

A method for the analysis of platelet-activating factor in platelets employing gas chromatography and selected-ion monitoring mass spectrometry with low-energy electron impact and stable isotope dilution was developed. The procedure involved Bligh and Dyer extraction of the sample followed by thin-layer chromatographic purification. Platelet-activating factor is successively hydrolysed to the corresponding 2-acetyl-1-O-alkylglycerol by digestion with phospholipase C, and the product is allowed to isomerize to the more thermodynamically stable 3-acetyl-1-O-alkylglycerol before column purification and derivatization of the free OH with tert.-butyldimethylchlorosaline-imidazole. This reagent is of common use in platelet-activating factor derivatization, but is made to react with 2-acetyl instead of 3-acetyl isomer. The advantages of using the latter for the final derivatization are discussed and this method is compared with others currently available for gas chromatographic-mass spectrometric analysis of platelet-activating factor.

Blood Platelets↗

PubMed1991

Gas chromatographic-mass spectrometric determination of two new antimycotic agents, 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole and 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole, in rabbit plasma following topical administration: a preliminary comparison with bifonazole.

A method for the analysis of the antimycotic drugs 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole, 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole and bifonazole in rabbit plasma, employing gas chromatography-mass spectrometry with selected-ion monitoring, was developed. The procedure involved single-step purification of the biological matrix via liquid-liquid extraction on Extrelut columns and use of a carrier substance to minimize the negative effects of adsorption sites during the gas chromatographic process. The limits of detection ranged from 0.1 to 1.4 ng/ml, starting from a 200-microliter sample. The method was applied to a preliminary evaluation of percutaneous absorption of both drugs in the rabbit after a single administration, in comparison with bifonazole.

Administration, Topical↗

PubMed1986

Study on the absorption of ketoprofen topically administered in man: comparison between tissue and plasma levels.

In this study the transcutaneous passage of ketoprofen (gel) topically administered and its distribution in the inner part of the knee-joint were evaluated in six patients. The ketoprofen concentrations detected were: 4.70 mcg/g +/- 3.87 in the intra-articular adipose tissue; 2.35 mcg/g +/- 2.41 in the capsular sample and 1.31 mcg/g +/- 0.89 in the synovial fluid. Plasma concentrations of the drug were also examined. In the samples studied, the ketoprofen levels amounted to about one hundred times higher than the plasma concentrations.

Administration, Topical↗

PubMed1985

Plasma and synovial fluid concentrations of isoxicam in meniscectomized patients.

Concentrations of isoxicam in the plasma and synovial fluid of 7 patients were investigated by means of high-pressure liquid chromatography. The samples were collected after 7 days' treatment with a single 200 mg isoxicam capsule taken each morning. A highly significant correlation was found (r = 0.82; p less than 0.05) between isoxicam concentrations in the plasma and in the synovial fluid. The mean concentration (+/- s.d.) was 25.54 +/- 10.91 micrograms/ml in the plasma and 17.47 +/- 6.54 micrograms/ml in the synovial fluid; the ratio between isoxicam concentrations in the synovial fluid and in the plasma was 71.06% +/- 18.83.

Adult↗

PubMed1968