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Biomedical subjects

L Campanella

Publications and source records attributed to L Campanella.

At least 19 recordsLinked to original sources

Salicylic acid determination in cow urine and drugs using a bienzymatic sensor.

An enzymatic biosensor was developed for salicylic acid (salicylate ion) determined using a Clark type gas diffusion electrode and two enzymes (tyrosinase and salicylate hydroxylase) entrapped in a cellulose triacetate membrane. After optimization, the method was applied to the determination of salicylic acid in cow urine. Relatively good recoveries were achieved, between about 83% and 109%, using the calibration curve, and acceptable precision (R.S.D. about 8%). The method is now being tested for the determination of salicylic acid contained in commercially available drug specialities or galenic products. So far agreement with nominal values has been found to be between 75% and 110% with a R.S.D. of less than 8%.

Animals↗

Tyrosinase inhibition organic phase biosensor for triazinic and benzotriazinic pesticide analysis (part two).

Several triazine pesticides, such as atrazine, are much more soluble in several organic solvents, such as chloroform, than in water. Our recent research was aimed at analyzing this class of pesticides using tyrosinase OPEE (organic phase enzyme electrodes), exploiting their inhibiting action on the tyrosinase enzyme when operating in water-saturated chloroform medium. In this work we studied the response of a tyrosinase inhibition enzyme sensor to several triazinic (simazine, propazine, terbuthylazine) and benzotriazinic (azinphos-ethyl and azinphos-methyl) pesticides (LOD=0.5x10(-9) mol l(-1)). Recovery trials were also performed in vegetal matrixes (corn, barley, lentils). Lastly, the effect of the solvent (chloroform or water) on the inhibition process was investigated via Hill's equation and the diffusion of analyte from the solvent to the enzyme membrane.

Biosensing Techniques↗

Comparison of fluorimetric, voltammetric and biosensor methods for the determination of total antioxidant capacity of drug products containing acetylsalicylic acid.

Antioxidant capacity of several drug specialities containing as mean component acetylsalicylic acid were experimentally evaluated using an enzymatic electrode, recently developed by the present authors, based on superoxide dismutase (SOD) enzyme. The precision of this method of analysis was found to be good (for drug samples RSD < or = 5%). The results were also compared with those ones by a traditional spectrofluorimetric method and by two other methods, respectively, based on cyclic and pulsed voltammetry, recently trialled by the present authors.

Antioxidants↗

Biosensors for determination of total antioxidant capacity of phytotherapeutic integrators: comparison with other spectrophotometric, fluorimetric and voltammetric methods.

Enzymatic electrodes based on superoxide dismutase (SOD) biosensors, working both in aqueous and non-aqueous solutions, recently developed by the present authors, were used to experimentally evaluate the antioxidant capacity of several phytotherapeutic diet integrators. The precision of this method of analysis was found to be reasonable (R. S. D. < or = 10%). The results were also compared with those obtained using a traditional spectrophotometric method as well as a spectrofluorimetric method described in literature. Lastly, the comparison was extended to another method based on cyclic voltammetry currently being trialled by the present authors.

Antioxidants↗

Determination of choline containing phospholipids in serum, bile and amniotic fluids by the derivative enzymatic-spectrophotometric method.

A comparison was performed of the analytical results obtained by applying a well-known enzymatic-spectrophotometric method for the determination of choline containing phospholipids in biological human fluids (sera, bile and amniotic fluids) following the standard procedure method, or else using the first or second derivative methods. In terms of result reproducibility the comparison was extended to include also a biosensor-based method developed in recent years by the present authors. Some advantages are associated with using the first derivative method in the case of serum samples containing blood traces, especially via the 'Gran's plot' method.

Amniotic Fluid↗

Biosensors for determination of total and natural antioxidant capacity of red and white wines: comparison with other spectrophotometric and fluorimetric methods.

Research was carried out to experimentally evaluate the antioxidant capacity of several red and white wines using a superoxide dismutase (SOD) biosensor recently developed by the present authors. Measurements were performed by comparing the biosensor response to increasing concentration of the superoxide radical produced in solution by the xanthine/xanthine oxidase system, both in the presence and absence of the test sample.The results were compared with those of two traditional spectrophotometric methods and of a spectrofluorimetric method described in literature.Lastly, also the polyphenol, sulfite and ascorbic acid contents of the different wine samples examined were measured using a tyrosinase biosensor, a sulfite oxidase biosensor and an ascorbate oxidase biosensor, respectively.

Antioxidants↗

Effects of advanced oxidation processes (AOPs) on the toxicity of a mixture of pharmaceuticals.

The possibility of applying main AOP techniques, namely ozonation, H2O2/UV photolysis and TiO2 photocatalysis to provide a significant reduction of toxicity of pharmaceutical mixtures has been evaluated. For the preparation of the mixture six pharmaceuticals were chosen among those found at highest concentrations in Sewage Treatment Plant effluents, namely carbamazepine, clofibric acid, diclofenac, sulfamethoxazole, ofloxacin and propranolol. The blue-green alga Synechococcus leopoliensis and the rotifer Brachyonus calyciflorus were utilised to assess the toxicity of the mixtures after AOP treatments. All the toxicity tests were performed using chronic standardized bioassays. The best results were obtained with ozonation. With this type of treatment a complete removal of mixture toxicity on S. leopolensis was obtained even after the shortest time of application (1 min). The ozonation treatment leads also to removal of all the pharmaceutical mixture toxicity on B. calyciflorus, by applying the oxidizing agent for at least for 2 minutes.

Animals↗

Determination of the antioxidant capacity of samples of different types of tea, or of beverages based on tea or other herbal products, using a superoxide dismutase biosensor.

Research was performed to experimentally evaluate the antioxidant capacity of different plant products sold by herbalists (ginger, dog rose, ginseng and camomile) and of several types of tea (ordinary tea, green tea, detheinated tea, lemon and peach flavoured tea) using a superoxide dismutase (SOD) biosensor recently developed by the present authors. Measurements were carried out by comparing biosensor response to the superoxide radical produced in solution using the xanthine-xanthine oxidase system, both in the presence and absence of the antioxidant sample considered. Precision of antioxidant capacity measures for herbal products and for non diluted samples was good, generally with a R.S.D.%< or =10% and a LOD value about 0.1 for relative antioxidant capacity. Also a "pool" of polyphenols from different tea samples was measured using a tyrosinase biosensor (LOD approximately 2 microM).

Antioxidants↗

Determination of hydrogen peroxide in disinfectant solutions using a biosensor with two antagonist enzymes.

The development and characterisation of a new biosensor for hydroperoxides is described, which is obtained by combining an oxygen gas diffusion amperometric electrode and two immobilized enzymes (peroxidase and tyrosinase) working in parallel and competing for the same substrate (catechol). The response of the biosensor to several hydroperoxides was investigated (LOD=0.5.10(-4) M for hydrogen peroxide). It was experimentally found that the biosensor is able to respond also to aqueous solutions of ionic peroxides (LOD=0.2.10(-4) M for potassium peroxidisulphate). The biosensor was applied to the determination of the hydrogen peroxide content of pharmaceutical products, i.e. aqueous disinfectant solutions (RSD% < or =0.5; recoveries by standard addition method between 96.0 and 98.5%).

Biosensing Techniques↗

Determination of antioxidant properties of aromatic herbs, olives and fresh fruit using an enzymatic sensor.

The aim was to experimentally evaluate the antioxidant capacity of different fresh aromatic herbs (field balm, marjoram, parsley, rosemary, sage, sweet basil), several varieties of olives from Central Italy ('Carboncello', 'Rosciolo', 'Olivastro', 'Coratello', 'Leccino', 'Frantoio') and several types of fresh fruit (apple, apricot, banana, cherry, fig, grape, medlar, melon, peach, pear, pineapple, plum, water melon, yellow plum) using a superoxide dismutase (SOD) biosensor developed by the present authors. Measurements were carried out by comparing the biosensor response to the concentration of superoxide radical produced in solution using a xanthine/xanthine oxidase system in the presence and absence of the antioxidant sample considered. Tests carried out on different samples of fruit and aromatic herbs showed that the homogenised samples had better antioxidant properties than the centrifuged ones (obtained by centrifuging the homogenate), which sometimes gave extremely low antioxidant capacity values. The reliability of the proposed method was checked by comparing the trend of some experimental results found using the SOD biosensor with those reported in the literature obtained using the classic (ORAC) method. The precision of this method of analysis was found to be good for samples of aromatic herbs (RSD% <or=8%), acceptable for homogenised fruit samples (RSD% <or=13%) and less good for homogenised and centrifuged samples (RSD% <or=20%).

Antioxidants↗

Evaluation of the inhibiting effects from exposure to microwaves on the respiratory activity of yeast cells or on enzyme activity.

Microwaves are used in medical applications, so their eventual toxicity effects must be carefully evaluated. An integral toxicity test, based on the monitoring of the respiratory activity of yeast cells, is proposed to evaluate the damage from microwave exposure. Different exposure times and microwave powers were considered. On supposing that the damages occur at enzymatic levels, the inhibiting effects of microwave exposure on two enzymes (glucose oxidase (GOD) and superoxide dismutase (SOD)), assumed like models as present in the human organism, was evaluated.

Animals↗

Determination of lecithin drug specialties and diet integrators; by means of first or second derivative enzymatic-spectrophotometric analysis.

The possibility has been investigated of applying derivative analysis to a classical enzymatic-spectrophotometric method for lecithin determination for the purpose of developing an analytical direct method that does not require long pretreatment of the test sample even in the case of turbid samples. Several samples of drugs and food integrators containing lecithin were thus tested using both the standard and the derivative method and then comparing the results obtained. The RSD% values of measurements on real (food or drugs) samples were always <2.5. Using a first derivative spectrophotometric method, average recovery was always between 102 and 105%.

Alcohol Oxidoreductases↗

Accelerated mineralization of the drug Diclofenac via Fenton reactions in a concentric photo-reactor.

The complete mineralization of concentrated solutions of Diclofenac (2-[(2,6-dichlorophenyl) amino] benzene-acetic acid) sodium salt C14H10C12NO2Na was carried out in a concentric cylindrical immersion photoreactor in batch mode operation. Irradiation with a lamp emitting light at 254 nm (400 W) achieved total mineralization of Diclofenac solutions (0.062 mM or TOC 20 mg C l(-1)) in times under an hour. The mineralization was carried out via Fenton photo-assisted treatment. A determination of the solution parameters was carried out to optimize the time of the Diclofenac pretreatment, the type and intensity of the light source, the effect of the concentrations of Fe-ions and the oxidant added in solution and the reactor recirculation rate. Diclofenac disappearance was monitored by high liquid pressure chromatography (HPLC). Concomitantly, the aromatic and aliphatic intermediates were also monitored under low-energy (36 W) light irradiation at 366 nm in order to be able to detect the intermediates by HPLC in the minute time scale. The decrease of the chemical oxygen demand was followed during Diclofenac degradation. The activation energy for the mineralization of Diclofenac was determined to be 4.02 Kcal mol(-1).

Anti-Inflammatory Agents, Non-Steroidal↗

Molecular characterization and action of usnic acid: a drug that inhibits proliferation of mouse polyomavirus in vitro and whose main target is RNA transcription.

Usnic acid is a normal component of lichen cells. This natural compound has shown different biological and physiological activities that might have a great relevance in pharmacology and clinics. For instance, usnic acid is known for its antibacterial and antiparasitic action. Also, the drug has a potential interest in cancer therapy because of its antimitotic and antiproliferative action. The molecular structure of usnic acid has been validated and further explored in this investigation. Many biological properties of this drug are known; however its potential antiviral action has not yet been evaluated. In this paper, we demonstrate that usnic acid is a potent inhibitor of the proliferation of mouse polyomavirus. Its action is not exerted at the level of virion entry into the host cell. Moreover, the abolition of viral DNA replication is an indirect consequence of the drastic inhibition of RNA transcription.

Actins↗

Superoxide dismutase biosensors working in non-aqueous solvent.

Enzymatic electrodes based on superoxide dismutase enzyme were developed. Using the superoxide dismutase enzyme sensor assembled according to the classical model, poor results were obtained. Results were improved by adopting a new way of assembling the biosensor using a cellulose triacetate layer in which the SOD enzyme is entrapped and sandwiched between two gas-permeable membranes, or using a kappa-carrageenan gel layer entrapping the enzyme, sandwiched between an external gas permeable membrane and an internal cellulose acetate membrane, coupled in each case to the oxygen amperometric transducer. Results obtained by applying the newly developed biosensor to assaying hydrophobic compounds showing radical scavenging properties, operating in dimethylsulfoxide, were also satisfactory.

Biosensing Techniques↗

An algal biosensor for the monitoring of water toxicity in estuarine environments.

An algal biosensor for toxicity assessment of estuarine waters is proposed. The sensor was obtained by coupling a suited algal bioreceptor (the cyanobacterium Spirulina subsalsa) to an amperometric gas diffusion electrode. The analytical device allows the monitoring of the evolution of photosynthetic O2 and the detection of alterations due to toxic effects caused by environmental pollutants present in the medium. Four chemical species representative of three main different classes of pollutants (heavy metals, triazinic herbicides, carbamate insecticides) were tested at different concentrations using a standardized natural water as experimental medium. In all the cases a toxic response was detected (i.e. a dose-related inhibition of photosynthetic activity was recorded) with good reproducibility.

Bacterial Proteins↗

Size-dependent concentrations of trace metals in four Mediterranean gastropods.

In order to gain more information on the possible use of four gastropod species as metal biomonitors for the Mediterranean area, the influence of body weight upon Cd, Cr, Cu, Pb and Zn concentrations was studied in specimens collected at locations with different degrees of environmental pollution. The selected species were the marine snails Monodonta turbinata Born and Monodonta mutabilis Philippi, and the limpets Patella caerulea L. and Patella lusitanica Gmelin. Significant differences between metal concentrations in individuals from different stations were tested by ANCOVA on log-transformed data with log body weight as covariate. For all species a positive correlation between metal concentrations and body weight was observed, which means that the largest individuals contained the highest levels of metals. The inclusion of body weight as covariate in the statistical analysis explained from 81% to 99% of the metal variability within the organisms and enabled the achievement of improvements in the detection of differences among sites. The four selected species provided a rather univocal picture of bioavailable metal loads at the different stations of the experimental area. Except for Cd, the metal concentrations recorded at the clean stations were found to lie in the range of the lowest values reported in the literature and can be employed as useful background levels which can be referred to for intraspecific comparison within the Mediterranean area. It is concluded that in view of its distribution, unambiguous identification, resistance to pollution and accumulation patterns M. turbinata has considerable potential as a biomonitor of trace metals over the Mediterranean.

Animals↗

Trace metals in seagrass, algae and molluscs from an uncontaminated area in the Mediterranean.

The concentrations of Cd, Cr, Cu, Pb and Zn were measured in specimens of four marine organisms--the seagrass Posidonia oceanica (L.) Delile, the brown algae Padina pavonica (L.) Thivy, and the two gastropod molluscs Monodonta turbinata Born and Patella caerulea L.--selected as possible cosmopolitan biomonitors of trace metals in the Mediterranean area. The organisms were collected at five coastal sites in Favignana Island (Sicily, Italy), an area virtually uninfluenced by anthropogenic activities. In order to gain a more complete picture of both the environmental conditions of the experimental area and the bioaccumulation patterns of the selected organisms, soluble and total metal concentrations were determined in coastal water samples collected at the same stations. The picture of bioavailable metal loads in the different sites of the selected area provided by the four species was rather univocal. An overall trend of increased metal concentrations at the station in which the local harbour is located was clear. On the other hand, the metal concentrations recorded at the 'clean' stations generally fall in the range of the lowest values available in the literature and may be considered as useful background levels to which to refer for intraspecific comparison within the Mediterranean area. Implications in biomonitoring of the observed accumulation patterns, especially in the different tissues of Posidonia oceanica, are discussed.

Animals↗