Biomedical subjects

Luigi Campanella

Publications and source records attributed to Luigi Campanella.

At least 19 recordsLinked to original sources

PubMed2006

Determination of Cd, Cu, Pb and Zn in neoplastic kidneys and in renal tissue of fetuses, newborns and corpses.

The incidence of kidney tumors in USA and Europe (in particular, Central Europe and Italy) has been dramatically increasing since the 1970s, possibly as a consequence of ongoing environmental pollution. Environmental factors have been considered responsible for at least 80% of the incidence of neoplastic diseases. To shed some light on this issue, the amounts of Cd and Pb were measured in neoplastic tissue and adjacent normal part of kidney excised for carcinoma and compared with those in renal tissues of fetuses, newborns and subjects that died of non-neoplastic diseases. Cd and Pb were determined by Inductively Coupled Plasma Atomic Emission Spectrometry and Atomic Absorption Spectrometry with Electrothermal Atomization. Metallothionein immunoperoxidase staining technique was used to localize the accumulation of Cd and Zn in the nephrons. Content of Cd and Pb in kidneys of fetuses and newborns was extremely low. However, it was significantly increased in adjacent-normal tissues of kidneys with carcinomas, and significantly higher compared to kidneys of individuals that died of non-neoplastic diseases. In tumoral tissues of the excised kidneys, Cd content was very low, while that of Pb significantly elevated. High amounts of Cd and Pb in the adjacent-normal parts of kidneys with carcinomas are suggestive of possible, individual or synergistic, effects of these pollutants on enzymatic systems, priming an oncogenic pathway. Detection of metallothioneins, primary ligands of Cd, exclusively in the cells of proximal tubuli, i.e. wherein renal carcinoma develops in over 80% of cases, strongly supports the assumption that Cd exerts a carcinogenic effect.

Cadaver↗

PubMed2005

Glutamate receptor incorporated in a mixed hybrid bilayer lipid membrane array, as a sensing element of a biosensor working under flowing conditions.

The realization of a reliable receptor biosensor requires stable, long-lasting, reconstituted biomembranes able to supply a suitable biomimetic environment where the receptor can properly work after incorporation. To this end, we developed a new method for preparing stable biological membranes that couple the biomimetic properties of BLMs (bilayer lipid membranes) with the high stability of HBMs (hybrid bilayer membranes); this gives rise to an innovative assembly, named MHBLM (mixed hybrid bilayer lipid membrane). The present work deals with the characterization of biosensors achieved by embedding an ionotropic glutamate receptor (GluR) on MHBLM. Thanks to signal (transmembrane current) amplification, which is typical of natural receptors, the biosensor here produced detects glutamate at a level of nmol L(-1). The transmembrane current changes linearly vs glutamate up to 100 nmol L(-1), while the limit of detection is 1 nmol L(-1). In addition, the biosensor response can be modulated both by receptor agonists (glycine) and antagonists (Mg(2+)) as well, and by exploiting the biosensor response, the distribution of different kinds of ionotropic GluR present in the purified sample, and embedded in MHBLM, was also evaluated. Finally, one of the most important aspects of this investigation is represented by the high stability of the biomimetic system, which allows the use of biosensor under flowing conditions, where the solutions flow on both biomembrane faces.

Biomimetic Materials↗

PubMed2005

Electrochemical determination of pharmaceuticals in spiked water samples.

The electrochemical behaviour of acidic and neutral pharmaceutical active compounds (PhACs) was studied by cyclic voltammetry and pulse voltammetric techniques on mercury, carbon nanotube paste, carbon paste and gold electrodes. The best results, in terms of sensitivity, linearity range and detection limits, were obtained by differential pulse voltammetry (DPV) for ofloxacin (LOD 5.2 microM), differential pulse polarography (DPP) for clofibric acid (LOD 4.7 microM) and normal pulse voltammetry (NPV) for diclofenac (LOD 0.8 microM) and propranolol (LOD 0.5 microM). An enrichment step of approximately two orders of magnitude was performed by a solid-phase extraction procedure (SPE) in order to concentrate the samples. The developed method was optimized and tested on spiked river water samples.

Clofibric Acid↗

PubMed2005

Lichen-based biosensor for the determination of benzene and 2-chlorophenol: microcalorimetric and amperometric investigations.

Preliminary microcalorimetric studies have been performed to analyse the response of a whole epiphytic lichen tissue (Evernia prunastri) to 2-chlorophenol (2Cl-phi), a pollutant of oil mill waste-water, in order to evaluate whether the tissue might be used to assess the toxic characteristics of polluted waters. The obtained results (lichen viability expressed in hours, enthalpy variations for the 2Cl-phi/lichen interactions) were used to create a lichen-based biosensor that uses an amperometric oxygen electrode (a Clark electrode) as a transducer. The lichen catalyses aromatic ring cleavage (via pyrocatechase enzymes present in the lichen), and transforms aromatic substances like 2Cl-phi into muconic acid (C6H6O4). Following a full electroanalytical characterisation, the performance of the proposed lichen biosensor was compared to that of a biosensor based on Pseudomonas putida cells, which was originally constructed to monitor benzene in different matrices (water, air, petrol and oil) and was tested in our laboratory previously.

Benzene↗

PubMed2004

Ecological batteries.

Explore the source record for details and available documents.

Energy-Generating Resources↗

PubMed2004

Selectivity of effects of redox-active cobalt(III) complexes on tumor tissue.

AIM: To estimate the selectivity of action of cobalt complexes on tumor tissue. MATERIALS AND METHODS: Cobalt(III) complexes containing both the tetradentate Schiff-base ligand derived from acetylacetone and ethylenediamine, and compounds of the vitamin PP series or their synthetic analogs, viz. nicotinamide, isonicotinamide or nicotinic acid, as extra (axial) ligands, were tested in vivo on transplanted mice tumors, namely Lewis lung carcinoma (3LL), melanoma B16, and mammary adenocarcinoma Ca755. concentrations of malondialdehyde in tissue extracts were measured by standard biochemical methods. The rate of DNA unwinding was used to detect DNA damage in tumor cells. Level of tumor hypoxia as well as bioenergetic status were estimated using 31P NMR spectroscopy in perchloric acid extracts of tissue. RESULTS: A significant and selective increase of malondialdehyde in tumor tissue reflecting activation of lipid peroxidation was found after administration of the complexes. The bioenergetic status in tumor was also selectively affected by the complexes: minimization of signals of high-energy phosphates was observed two hours after injection of the complexes. An increase of the number of DNA single-strand breaks was registered in tumor tissue, supporting the suggestion that the complexes may directly affect DNA. A correlation between the above tumor effects and the structure of axial ligands was demonstrated. CONCLUSION: Cobalt(III) complexes affect tumor tissue with a very high level of selectivity; in particular they activate lipid peroxidation, induce DNA single-strand breaks, suppress the bioenergetic status, and enhance hypoxia. It is supposed that the selective action of these complexes on tumor tissue is due to peculiarities of tumor microphysiology, in particular significant tumor hypoxia.

Adenocarcinoma↗

PubMed2003

Chemometric investigation of the efficiency of different TiO(2)-based catalysts as principal components of TOC photochemical sensors under development.

There is an increasing demand for measurement of organic carbon in solutions both in industry and in environmental research for the purpose of continuous water-quality monitoring. Practically all the methods used are based on a catalytic system in which metal oxides play a major role. The development of a new TOC/DOC measurement system, in our work, uses a mixed anatase-rutile form of TiO(2 )as catalyst of the mineralisation process, and direct measurement of the CO(2) produced, by a gaseous diffusion electrode. The entire research is based on heterogeneous catalysis using an immobilised catalyst, which can offer considerable advantages over other methods of catalysis. Four different catalytic systems were analysed. Three involved thermal immobilisation of TiO(2) on glass supports (glass spheres and glassy particulates) or on an Al metal grid. One further system consisted of direct oxidation of a Ti grid at high temperatures. The system was illuminated using a 350 nm UV source (350 mW cm(-2)) contained in a home-made measurement cell. Five molecules-malic acid, pentachlorophenol, sodium dodecylsulfate, hydroquinone, and citric acid-which were deemed to be representative and had been investigated in several previous studies, were used as photodegradation targets. However, it was not possible to obtain a direct expression of "catalytic efficiency" simply by reading the data obtained, nor any indirect molecular "recalcitrancy" scale. Chemometric analysis, by principal components analysis, allows the five used catalytic systems to be easily compared each other and a single PC component is able to perform classification.

Journal Article↗

PubMed2003

Thermogravimetric and kinetic methods to date wood finds. First results.

Fresh (larch and fir, in its white and red varieties) and ancient wood samples (dating respectively to the 13th, 15th and 17th centuries) were subjected to thermogravimetric analysis (TG and DTG). The resulting thermogravimetric data were then used to construct archeometric curves for the wood varieties tested. In a preliminary approach, it was attempted to correlate the onset temperature of the thermogravimetric step corresponding to cellulose decomposition with the age (expressed in centuries) of the samples, although the results obtained were anything but brilliant. More encouraging results were obtained by examining the relationship between wood sample age and the value of the (percent cellulose/percent lignin) ratio computed from the thermogravimetric data. Lastly, a procedure for processing data obtained from the TG curves was applied to a kinetic analysis of the processes that take place when wood samples are subjected to a temperature regime with a constant heating rate, obtaining values for the activation energy of the TG step corresponding to the decomposition of cellulose. Also using these data it was attempted to construct archeometric curves, obtaining results that varied quite significantly according to the wood species tested.

Abies↗

PubMed2002

Determination of organophosphorus pesticide residues in human tissues by capillary gas chromatography-negative chemical ionization mass spectrometry analysis.

We describe an analytical method that allows the determination of organophosphorus pesticides (OPs) in different human tissues. It involves an extraction procedure with ethanol-ethyl acetate, followed by gel permeation chromatography clean-up step and analysis by capillary gas chromatography-negative chemical ionization mass spectrometry in the selected ion monitoring mode. The method was tested for 37 OPs and the recoveries obtained vary between 60 and 106% with standard deviations ranging between +/-2 and +/-10. These values are independent of the analyzed tissue. Peak area repeatability as RSD for some OPs was < or =4.8% while a good linear relationship in the range 1.0-500 pg microl(-1) with r(2)> or =0.9878 was obtained. The limit of detection for the 37 OPs falls between 0.01 and 0.09 ng g(-1) with an RSD< or =9.5%. The analytical set up in this paper has been used to analyze different samples of human tissues (liver, healthy kidney, cancer kidney and adipose tissue) of 24 patients. The number of the identified OPs in the tissue samples is different (max. 20) according to the sample while their concentration ranges between the limit of detection and 28.0 ng g(-1). The highest concentrations have been determined in liver samples without any pathology (0.4-28.0 ng g(-1)) while the lowest concentrations have been determined in healthy kidney samples (0.01-1.50 ng g(-1)). In the cancer kidney samples OP concentrations vary between 0.03 and 4.6 ng g(-1): these concentrations are more elevated than those determined in healthy kidney samples. The comparison between the concentration of OPs determined in the healthy part, when possible, and those determined in the cancer part of the same kidney sample are very interesting: in fact, in the latter the OP concentration is generally 1-2-times higher than that in the former, an index of lower enzymatic activity in the cancer tissue.

Adipose Tissue↗

PubMed2002

Reduction of hexavalent chromium by H2O2 in acidic solutions.

The rates of the reduction of Cr(VI) with H2O2 were measured in NaCl solutions as a function of pH (1.5-4.8), temperature (5-40 degrees C), and ionic strength (I = 0.01-2 M) in the presence of an excess of reductant. The rate of Cr(VI) reduction is described by the general expression -d[Cr(VI)]/dt = k2[Cr(VI)](m)[H2O2](n)[H+](z), where m = 1 and n and z are two interdependent variables. The value of n is a function of pH between 2 and 4 (n = (3 x 10(a))/(1 + 10(a)), where a = -0.25 - 0.58pH + 0.26pH2) leveling off at pH < 2 (where n approximately = 1) and pH > 4 (where n approximately = 3). The rates of Cr(VI) reduction are acid-catalyzed, and the kinetic order z varies from about 1.8-0.5 with increasing H2O2 concentration, according to the equation z = 1.85 - 350.1H2O2 (M) which is valid for [H2O2] < 0.004 M. The values of k2 (M(-(n+z)) min(-1)) are given by k2 = k/[H+](z) = k1/[H2O2](n)[H+](z), where k is the overall rate constant (M(-n) min(-1)) and k, is the pseudo-first-order rate constant (min(-1)). The values of k in the pH range 2-4 have been fitted to the equation log k = 2.14pH - 2.81 with sigma = +/- 0.18. The values of k2 are dependent on pH as well. Most of the results with H2O2 < 3 mM are described by log k2 = 2.87pH - 0.55 with sigma = +/- 0.54. Experimental results suggest that the reduction of Cr(VI) to Cr(III) is controlled by the formation of Cr(V) intermediates. Values of k2 and k calculated from the above equations can be used to evaluate the rates of the reaction in acidic solutions under a wide range of experimental conditions, because the rates are independent of ionic strength, temperature, major ions, and micromolar levels of trace metals (Cu2+, Ni2+, Pb2+). The application of this rate law to environmental conditions suggests that this reaction may have a role in acidic solutions (aerosols and fog droplets) in the presence of high micromolar concentrations of H2O2.

Aerosols↗

PubMed2002

Free and total amino acid composition in blue-green algae.

A simple, accurate and reproducible analytical method is described for the extraction and the simultaneous determination of 18 amino acids in different for geographical origin Spirulina alga samples using phenylisothiocianate as derivatizating agent in natural feed. The best experimental hydrolysis conditions have been studied varying the temperature, the time and the hydrolyzing reagent. The separation and the quantitative analysis of the by-products have been carried out by HPLC analysis and UV detection. An amino acid pattern is compared with that proposed by the Food Agriculture Organization (FAO) for an ideal protein and with those of some traditional feed.

Amino Acids↗

PubMed2002

Eptastigmine, nicotinamide and nicotinic acid determination using an inhibition enzyme sensor; application to pharmaceutical analysis.

An enzyme inhibition biosensor, developed in our laboratory and previously used for the analysis of compounds with anticholinesterase activity (e.g. physostigmine, neostigmine, pyridostigmine nicotine and organophosphorus compounds) has now been tested for the analysis of another recently synthesized cholinesterase inhibitor, i.e. eptastigmine. In addition nicotinic acid and nicotinamide, although displaying weaker inhibition properties, were also tested in pharmaceutical products using the same inhibition enzyme sensor. The biosensor consisted of a hydrogen peroxide amperometric electrode coupled to a functionalised nylon membrane chemically bonding both the enzymes butyrylcholinesterase and choline oxidase; a butyrylcholine standard solution in glycine buffer acted as substrate. The response of the system to all the inhibitors considered was characterised completely and the analysis of several pharmaceutical formulations containing nicotinamide or nicotinic acid was also performed.

Biological Assay↗

PubMed2002

Integral toxicity test of sea waters by an algal biosensor.

An integral toxicity test, based on an algal biosensor and suitable to be used in sea water, is presented. The biosensor was designed and built by coupling a Clark oxygen electrode as transducer and the marine alga Spirulina subsalsa as biological mediator; it constitutes the "core" in a lab-scale prototype of a flow apparatus suitable to continuously monitor, in sea water, the photosynthetic activity of the alga and, from its variation, the marine pollution from the toxicological point of view. Inorganic pollutants (heavy metals) were tested in previous researches while organic ones (chlorophenols, pesticides and surfactants) are the object of the present paper.

Bacterial Proteins↗

PubMedDate not supplied

Photodegradation of azodyes: comparison of different catalytic systems and control of the effective mineralisation.

Three different azodyes were used as target molecules to test the efficiency of the photodegradation process catalysed by titanium dioxide under UV irradiation. A comparison of different catalytic systems was performed using the catalyst both free in solution (system I) and immobilised in a polymeric membrane (system II). Iron oxalate and a conducting polymer (polyaniline, PA) were added to the I and II systems respectively to check an eventual synergetic effect. The research evolved through three different steps involving each one the use of a different analytical method. Shortly, the UV spectrophotometry were preliminarily used to monitor the bleaching process and allowed to choose the best catalytic system, HPLC and GC/MS were used to monitor the appearance and disappearance of the photodegradation intermediates and, lastly, the effective mineralisation was tested by an indirect ICP (Inductively Coupled Plasma) determination of the produced carbon dioxide.

Azo Compounds↗

PubMedDate not supplied

Characterization of wax manufactures of historical and artistic interest.

Purpose of this scientific research is the physic and chemical characterization of two historical wax manufactures, made at the end of XIX century by Francesco Bianchi, a papal engraver. The chemical and analytical investigation was necessary to complete and to confirm the restorer's work. The IR Spectroscopy, X-Ray and GC-MS, the best technique to characterise wax, allowed us to obtain the following results. The two manufactures were made with commercial beeswax: in fact, the relative chromatograms showed unchanged peaks about esters of palmitic acid with C24 to C32 alcohol molecules; using standard beeswax we determined the same amount of hydrocarbons present in the wax manufactures. We found several hydrocarbons in these beeswax materials so that it is reasonable to think about successive modifications. ZnO (white zinc), a pigment, was added, probably due to its colour and covering capacity. Sb2S3, Anthimoniun vermilion, a red-orange pigment, was added to these manufactures to give them a soft pink-orange colour. By all used techniques we determined some modifications in the original beeswax; surely they were made to get a more malleable, mouldable, and then more able to be modelled wax.

Art↗

PubMedDate not supplied

Optimisation of a photochemical sensor for total organic carbon measurement.

A new tool for the measurement of TOC based on the heterogeneous photocatalysis activated by two different light sources has been planned. The instrument is constituted by a cell where the degradation occurs thanks to both the UV irradiation and the presence of a powered catalyst and by a measurement cell lodging CO2 gas permeable membrane electrode (detector), thermometer, inlet and outlet ways for the samples. One of the sources has a maximum emission at 254nm, while the other simulates the solar spectrum. A suspension (1 g/L) of titanium dioxide (Degussa P25) has been used to catalyse the process. A magnetic stirrer and a circulating pump avoid the deposition of the catalyst on the bottom of the reactor. The online measurement of produced CO2 was performed on 11 molecules (commercial names: Parachlorophenol, D-Glucose, Acid Blue 29, Atraton, Aspirin, Dimethoate, Aldicarb sulfone, Hydroquinone, (R)-Propranolol, Citric acid, Atrazine) to test the system efficiency. The experimental CO2 value was compared with the theoretical TOC value calculated by means of the structure's formula.

Carbon↗

PubMedDate not supplied

Studies on simulated ageing of paper by photochemical degradation.

The study of the ageing of two paper types was performed on monitoring it during a simulated process by means of the measure of the photocatalytic degradation of the paper cellulose. Such evaluation was possible due to the combined responses of a photosensor based on titanium dioxide in suspension, of an enzymatic biosensor based on superoxide dismutase (SOD), of a specific conductivity sensor and of an enzymatic biosensor based on glucose oxidase.

Biosensing Techniques↗

PubMedDate not supplied

Determination of environmental persistence and thermogravimetric analysis of paper artificially aged by photoirradiation.

Fabriano paper was aged by irradiation with ultraviolet light (k=310) in a veterometer for 300 hours. At fixed time intervals, samples of the paper under test were analysed by titanium dioxide photosensor to determine electrochemically the "environmental persistence" index, by a suitable conductimeter method, to determine the specific conductivity variation and by thermogravimetry to determine the moisture content, the onset temperature of the cellulose degradation process and the value of the activation energy of the same process. The behaviour of these different types of indicators displayed approximately monotonous trends as a function of time.

Cellulose↗