Biomedical subjects

C Botrè

Publications and source records attributed to C Botrè.

At least 19 recordsLinked to original sources

PubMed2001

Toxicity testing in environmental monitoring: the role of enzymatic biosensors.

Biological toxicity testing is a rapidly expanding field involving numerous bioanalytical techniques. The enzymatic biosensors are valuable screening tools to identify pollutants and/or toxic agents in the environment and/or in food matrices, thus representing a valid alternative to animal testing in analytical toxicology. Inhibition based biosensors here presented have been proved to represent alternative assays for the toxicity evaluation of warfare agents and endocrine disrupting chemicals as well as algal toxins (phycotoxins) in the contamined sea foods (mainly clams and other mollusks). Results obtained by inhibition studies performed by means of several enzymatic biosensors indicate the reliability of the proposed method and the possibility to extend such an experimental approach to other toxicants as a simple, rapid and cheap biotest, to be used easily also "on the spot".

Animals↗

PubMed1997

Atmospheric pollution originating from the interaction of different gaseous effluents.

During the last few years, several episodes of atmospheric pollution have been reported in a limited area near Guidonia, Rome. The area contains a disposal plant, Inviolata, for the collection of municipal solid waste (MSW) and a famous thermal water resort, the Acque Albule spring, which is a source of water rich in H2S. We conducted a multiparametric study in the areas surrounding the solid waste disposal plant and the Acque Albule spring. The concentration of main gaseous effluent was continuously monitored over a period of 4 months and the data relating to the meteorologic conditions in the area during the last few decades were examined. Our results suggest that most of the atmospheric pollution is due to the interaction of different gaseous effluents. Specifically, the presence of relatively high levels of hydrogen sulfide in the atmosphere, constantly released in large amounts by the Acque Albule springs, and of biogases (mainly hydrocarbons) from the organic matter present in the solid waste continuously unloaded and stored at the disposal plant, lead to mixing and photochemical interactions between these chemical compounds, which in turn are responsible for most of the polluting effects. Such interactions are promoted by the strong solar irradiation in the area that is enhanced by the peculiar local meteorological features that do not allow the pollutants to disperse.

Air Pollutants↗

PubMed1994

Potentiometric determination of carbonic anhydrase activity in rabbit carotid bodies: comparison among normoxic, hyperoxic and hypoxic animals.

The catalytic activity of carbonic anhydrase (CA) contained in the glomus cells of mammalian carotid bodies has been determined in vitro by a potentiometric method. Experiments performed on whole rabbit carotid bodies have shown a very low variability, in terms of the overall CA activity, among organs belonging to different animals maintained in normoxic conditions. Repeated assays performed on each carotid body have shown a marked decrease of the overall CA activity after the first assay, thus suggesting the presence of at least two different forms of enzyme. Experiments performed on carotid bodies belonging to rabbits maintained in normal, hyperoxic and hypoxic conditions have shown that the overall CA activity follows the sequence: hypoxic > normoxic > hyperoxic, matching with the corresponding physiological activity of the carotid body.

Animals↗

PubMed1993

Determination of L-glutamate and L-glutamine in pharmaceutical formulations by amperometric L-glutamate oxidase based enzyme sensors.

An amperometric biosensor for the direct determination of L-glutamate was developed by chemical bonding of L-glutamate oxidase (GAO) on a carboxylic Nylon membrane with polyazetidine prepolymer (PAP), and using a hydrogen peroxide electrode as indicating sensor. The biosensor is specific for L-glutamate and the peculiar analytical properties (linearity range, reproducibility, accuracy) were experimentally determined. Furthermore, the same basic biosensor was also modified to be used and characterized for the direct determination of L-glutamine. This L-glutamine biosensor was obtained by coimmobilizing, on two separate membranes, glutamic acid oxidase and glutaminase (GMN) on the same biosensor. The two sensors were then used for the determination of glutamate and L-glutamine contained in pharmaceutical formulations and the results were compared with those obtained by other analytical methods.

Amino Acid Oxidoreductases↗

PubMed1992

Determination of glutamic acid decarboxylase activity and inhibition by an H2O2-sensing glutamic acid oxidase biosensor.

The catalytic activity of the enzyme L-glutamic acid decarboxylase (GAD) is determined by an amperometric method based on a recently developed glutamate-selective biosensor. The biosensor is composed of an amperometric H2O2 electrode and a biocatalytic membrane containing the enzyme glutamic acid oxidase (GAO). The biosensor allows the direct and continuous measurement of GA levels by monitoring the H2O2 produced at the electrode interface as a coproduct of the GAO-catalyzed GA oxidation to alpha-ketoglutaric acid. Since GA is transformed to gamma-aminobutyric acid and CO2 under the catalytic activity of GAD, the rate of GA consumption in solution, monitored by the GAO biosensor, represents a reliable measure of GAD catalytic activity. Additional experiments performed in the presence of different concentrations of the GAD inhibitor valproic acid have shown the suitability of the proposed approach for the study of GAD inhibitors also. Discussion of the main experimental characteristics of this new analytical method is given in terms of sensitivity, reproducibility, and reliability of the experimental results and ease, time, and cost of operation.

Amino Acid Oxidoreductases↗

PubMed1991

Interactions between calcium entry blocking drugs and carbonic anhydrase.

The interactions between some of the most common calcium entry blocker drugs (CEB) and the enzyme carbonic anhydrase (CA) are studied in the present work by an electroanalytical approach. The study comprises drugs belonging to the classes of phenylalkylamines, dihydropyridines, benzothiazepines and piperazines. The evaluation of the potential inhibitory power towards CA was performed either by measuring the speed of CO2 diffusion taking place from a buffered solution of NaHCO3, or by monitoring the metabolic activity of yeast cells. The results obtained according to both of these procedures have shown that verapamil and gallopamil are endowed with a relevant inhibitory power on CA catalytic activity, whereas all the other compounds, tested in the same experimental conditions, did not show any effect on CA activity.

Animals↗

PubMed1990

Determination of carbonic anhydrase activity by a pCO2 sensor.

A potentiometric method capable of determining carbonic anhydrase (CA) activity in vitro and based on the use of a pCO2 sensor is presented. By means of the procedure described here it is possible to follow the rate of CO2 diffusion that takes place in a buffered solution of NaHCO3 in either the presence or the absence of CA. All experimental parameters that affect the speed of HCO3- dehydration, as well as the speed of CO2 diffusion, can be fixed and kept constant for the duration of every assay. The advantage of this method is that the overall dehydration plus diffusion process can be followed as it actually takes place in open thermodynamic systems far from equilibrium. The results obtained strongly confirm the hypothesis of a facilitating role of CA toward the rate of CO2 diffusion.

Animals↗

PubMed1978