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Biomedical subjects

L Campanella

Publications and source records attributed to L Campanella.

At least 55 records · Page 3Linked to original sources
PubMed1990

Voltammetric studies on the electrochemical behaviour of membrane-entrapped hemes.

The electrochemical behaviour of Fe(III)-protoporphyrin IX entrapped into a cellulose triacetate membrane has been investigated by cyclic voltammetry. The physical entrapment into a solid matrix does not modify the redox properties of the entrapped hemes, which also act as efficient promoters in the electrochemistry of cytochrome c. Such a system represents a promising example of a simple 'solid-state' promoter, and stimulates further investigations in order to obtain more complex systems that may be of significance for basic and applied bioelectrochemistry.

Electrochemistry↗
PubMed1990

Chemometric study and analytical enzymatic methods for diagnosis of cholesterol gallstones.

The lithogenic index (IL) provides an estimate of cholesterol saturation in gallbladder bile and is of possible value for prediction of gallstone formation. A package for pattern recognition of analytical chemical data, known as "Parvus", was used to study the different values of IL obtained experimentally using common enzymic methods for cholesterol and bile salts and other analytical techniques for phospholipids. Ten patients were investigated and some interesting conclusions were drawn, both on the equivalence of various analytical methods for the determination of phospholipids and on the contribution of pattern recognition analysis to the diagnosis of gallstones.

Bile↗
PubMed1990

Determination of inorganic phosphate in drug formulations and biological fluids using a plant tissue electrode.

A suitable biosensor for the analysis of inorganic phosphate was developed by coupling the enzyme glucose oxidase to a slice of potato (Solanum tuberosum) containing the acid phosphatase, and using an amperometric Clark electrode as an indicating sensor. Phosphate concentration can be determined from its inhibition on the acid phosphatase activity. Measurements were carried out at steady-state conditions and the available concentration range of phosphate, repeatability and accuracy, on phosphate standard solutions, were experimentally determined. Finally the sensor was used in pharmaceutical and biological matrices. The results were compared with those ones obtained by Bartlett's spectrometric method.

Acid Phosphatase↗
PubMed1990

Chemometric investigation of some analytical methods used for the chemical test of foetal lung maturity.

The lecithin/sphingomyelin (L/S) ratio is particularly important for the prediction of foetal lung maturity. A package for pattern recognition of analytical chemical data, "Parvus", was used to handle the different values of the L/S ratio obtained experimentally by common amperometric, spectrometric and chromatographic methods for the determination of lecithin. Eight subjects were considered and some interesting conclusions drawn on the equivalence of different analytical methods of determining lecithin in amniotic fluid.

Adult↗
PubMed1990

Suitable potentiometric enzyme sensors for urea and creatinine.

Enzyme sensors for urea and creatinine were developed by coupling an ammonia gas-diffusion electrode with triacetate cellulose membranes entrapping urease or creatinine deiminase enzymes. Satisfactory results were obtained by using these sensors both in standard solutions and in authentic biological matrices.

Aminohydrolases↗
PubMed1989

Membrane-entrapped microperoxidase as a 'solid-state' promoter in the electrochemistry of soluble metalloproteins.

Immobilization of biological systems in solid matrices is presently of great interest, in view of the many potential advantages associated with both the higher stability of the immobilized macromolecules and the potential utilization for biotechnology. In the present paper the electrochemical behaviour of the undecapeptide from cytochrome c (called microperoxidase) tightly entrapped in cellulose triacetate membrane is reported; its utilization as 'solid-state' promoter in the electrochemistry of soluble metalloproteins is presented. The results obtained indicate that: (i) membrane-entrapped microperoxidase undergoes rapid reversible electron transfer at a glassy carbon electrode; (ii) the electrochemical process is diffusion-controlled; (iii) entrapped microperoxidase acts as 'solid-state' promoter in the electrochemistry of soluble cytochrome c and of azurin.

Azurin↗
PubMed1988

Cancer antigen 125, tissue polypeptide antigen, carcinoembryonic antigen, and beta-chain human chorionic gonadotropin as serum markers of epithelial ovarian carcinoma.

Cancer antigen 125 (CA 125) is common to most epithelial ovarian tumors. Therefore, it is potentially a good marker of this disease. This hypothesis was evaluated by measuring the serum levels of CA 125 in 81 patients with ovarian cancer (25 with nonactive and 56 with active disease), in 105 patients of both sexes with nonovarian tumors, and in 171 healthy controls of both sexes. The serum levels of three other markers, tissue polypeptide antigen (TPA), carcinoembryonic antigen (CEA), and human chorionic gonadotropin, beta subunit (beta-hCG), were also measured in the same 357 subjects. The results of this study clearly indicate the clinical irrelevance of both CEA and beta-hCG as tumor markers in ovarian carcinomas. Conversely, the clinical usefulness of CA 125 and TPA was confirmed. In particular, CA 125 and TPA showed comparable sensitivity, while CA 125 showed a higher specificity for ovarian cancer than TPA. The association of CA 125 with TPA was very useful in continuous observation of patients with active disease in order to evaluate the clinical effectiveness of the therapy. Moreover, for patients in clinical remission, the markers allowed early detection of a recurrence of the disease.

Adult↗
PubMed1988

Benzylpenicillin PVC membrane electrode for the determination of antibiotics in formulations.

A PVC (polyvinychloride) ion selective electrode, employing benzyldimethyl-cetylammoniumbenzylpenicillin as sensor, was prepared, characterized and applied to the analysis of commercially available formulations containing benzylpenicillin and other antibiotics of the penicillin or cephalosporin group. The results are compared with those obtained by using the corresponding liquid membrane electrode.

Journal Article↗
PubMed1988

Polymeric membrane electrodes for drug analysis.

Two new polymeric membrane electrodes selective to cholate and to benzylpenicillinate, based respectively on PVC membranes containing polybenzyl-propargilamine as conductor polymer and benzyldimethylcethylammonium-cholate, or -benzylpenicillinate as exchangers, have been prepared, and applied to the determination of cholic acids, anionic surfactants and antibiotics. Results are compared with those ones obtained by analogous PVC sensors and liquid membrane sensors, previously described.

Journal Article↗
PubMed1985

Determination of choline-containing phospholipids in human bile and serum by a new enzyme sensor.

A simple method for direct determination both of choline and lecithin (phosphatidylcholine) in human bile and blood sera was developed. An enzyme electrode, based on immobilized choline oxidase on nylon net and an oxygen Clark electrode was assembled. Phosphatidylcholine can be determined by use of phospholipase D as hydrolyzing agent. Reliable results were obtained in the case of determination of lecithin and choline in bile samples.

Alcohol Oxidoreductases↗
PubMed1984

Total phosphorus determination in human bile. Comparison between two spectrometric methods.

The two most commonly used spectrometric methods for the determination of the phosphorus content of human bile are compared. The optimum experimental conditions are studied, and the analytical characteristics of the two methods, using both standard samples and human bile, are evaluated. The methods are compared on the basis of their sensitivity, precision and accuracy, and the correlation between the two techniques demonstrated using fifteen samples of human bile. Data obtained by both methods have been used to calculate lithogenic index values.

Journal Article↗