83 results on '"Rocchitta, G"'
Search Results
2. Glutathione deficiency potentiates manganese-induced increases in compounds associated with high-energy phosphate degradation in discrete brain areas of young and aged rats
- Author
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Desole, M. S., Serra, P. A., Esposito, G., Delogu, M. R., Migheli, R., Fresu, L., Rocchitta, G., and Miele, M.
- Published
- 2000
- Full Text
- View/download PDF
3. Glutamate and catabolites of high-energy phosphates in the striatum and brainstem of young and aged rats subchronically exposed to manganese
- Author
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Miele, M., Serra, P. A., Esposito, G., Delogu, M. R., Migheli, R., Rocchitta, G., and Desole, M. S.
- Published
- 2000
- Full Text
- View/download PDF
4. Bifenili Idrossilati come Inibitori di Tirosinasi: Uno Studio Spettrofotometrico ed Elettrochimico
- Author
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Ruzza, P., Serra, P.A., Fabbri, D., Dettori, M.A., Rocchitta, G., and Delogu, G
- Subjects
bifenili idrossilati ,Tirosinasi ,biosensori - Abstract
La tirosinasi [EC 1.14.18.1] è un enzima, contenente rame, coinvolto nella biosintesi della melanina, nell'indesiderato imbrunimento enzimatico di alimenti di origine vegetale, nella melanogenesi patologica e nei fenomeni di muta degli insetti [1]. La tirosinasi catalizza l'ossidazione sia dei monofenoli (attività monofenolasica o cresolasica) che degli o-difenoli (attività difenolasica o catecolasica) a o-chinoni, pertanto la ricerca di nuovi inibitori della tirosinasi può portare allo sviluppo di nuovi agenti per lo sbiancamento della pelle, a nuovi farmaci e composti per il controllo degli insetti nocivi [2]. I bifenili idrossilati sono una classe di polifenoli ampiamente presenti in natura [3], alcuni di essi manifestano una elevata attività biologica come ad esempio gli ellagitannini, la vancomicina e le bifenomicine. E' noto come i bifenili manifestino una maggiore attività antiossidante e siano generalmente meno tossici dei corrispondenti monomeri [4]. Nel ambito delle nostre ricerche riguardanti la sintesi di bifenili idrossilati con interessanti caratteristiche stereochemiche e biologiche [4], abbiamo preparato una piccola collezione di bifenili idrossilati a simmetria C2 e abbiamo valutato la loro capacità di agire da inibitori della tirosinasi utilizzando sia metodi spettrofotometrici che elettrochimici. I risultati ottenuti con entrambi i metodi sono risultati comparabili. La maggior parte dei composti hanno dimostrato una maggiore attività inibitoria rispetto al 4,4'-diidrossibifenile, un noto inibitore di tirosinasi. I nostri risultati suggeriscono che i bifenili idrossilati costituiscono una promettente classe di composti per lo sviluppo di nuovi inibitori dell'enzima tirosinasi
- Published
- 2017
5. PHENOLS AND HYDROXYLATED BIPHENYLS AS SUSTAINABLE COMPOUNDS FOR NANOTECHNOLOGIES
- Author
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Dettori M.A., Fabbri D.a, Pani G., Balmas V.b, Migheli Q., Monti, Rocchitta G., Serra P.A., and Delogu G.
- Subjects
phenol ,hydroxylated biphenyls ,nanotechnologies - Abstract
We prepared a small collection of phenols and its C2-symmetry hydroxylated biphenyls to be applied for a novel nanotechnology-based approach in biosensor building and seed dressing. Biosensor technology provides easy-to-use and effective devices for medical, environmental and agro-food analyses. Amperometric biosensors are often coated with a polymeric permselective film, usually poly-Phenylendiamines (PD), to avoid electroactive interference by reducing agents, present in the target medium. We evaluated the permselectivity, stability and lifetime of polymers electrosynthesized from naturally occurring phenylpropanoids in monomeric and dimeric forms1. Among tested compounds, poly-magnolol and poly-isoeugenol can be regarded as effective and a healthier alternatives to poly-PD film in biosensor applications2.
- Published
- 2016
6. Estrogen, neuroinflammation and neuroprotection in Parkinson’s disease: Glia dictates resistance versus vulnerability to neurodegeneration
- Author
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Morale, Mc, Serra, Pa, L'Episcopo, F, Tirolo, C, Caniglia, S, Testa, N, Gennuso, F, Giaquinta, G, Rocchitta, G, Desole, Ms, Miele, E, Marchetti, Bianca Maria, and Review, . EPUB DEC.
- Subjects
Parkinson's disease ,Models, Neurological ,Biology ,Nervous System ,Neuroprotection ,chemistry.chemical_compound ,Degenerative disease ,estrogen ,medicine ,Animals ,Humans ,Neuroinflammation ,Inflammation ,Neurons ,glia-neuron crosstalk ,Pars compacta ,General Neuroscience ,MPTP ,Neurodegeneration ,Dopaminergic ,Estrogens ,Parkinson Disease ,medicine.disease ,Disease Models, Animal ,Oxidative Stress ,nervous system ,chemistry ,1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ,Nerve Degeneration ,Neuroglia ,Neuroscience - Abstract
Post-menopausal estrogen deficiency is recognized to play a pivotal role in the pathogenesis of a number of age-related diseases in women, such as osteoporosis, coronary heart disease and Alzheimer's disease. There are also sexual differences in the progression of diseases associated with the nigrostriatal dopaminergic system, such as Parkinson's disease, a chronic progressive degenerative disorder characterized by the selective degeneration of mesencephalic dopaminergic neurons in the substancia nigra pars compacta. The mechanism(s) responsible for dopaminergic neuron degeneration in Parkinson's disease are still unknown, but oxidative stress and neuroinflammation are believed to play a key role in nigrostriatal dopaminergic neuron demise. Estrogen neuroprotective effects have been widely reported in a number of neuronal cell systems including the nigrostriatal dopaminergic neurons, via both genomic and non-genomic effects, however, little is known on estrogen modulation of astrocyte and microglia function in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease. We here highlight estrogen modulation of glial neuroinflammatory reaction in the protection of mesencephalic dopaminergic neurons and emphasize the cardinal role of glia-neuron crosstalk in directing neuroprotection vs neurodegeneration. In particular, the specific role of astroglia and its pro-/anti-inflammatory mechanisms in estrogen neuroprotection are presented. This study shows that astrocyte and microglia response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injury vary according to the estrogenic status with direct consequences for dopaminergic neuron survival, recovery and repair. These findings provide a new insight into the protective action of estrogen that may possibly contribute to the development of novel therapeutic treatment strategies for Parkinson's disease.
- Published
- 2006
7. HYDROXYLATED PHENOLS AND DIMERS: A VALUABLE SOURCE OF BIOACTIVE COMPOUNDS
- Author
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FABBRI D., DETTORI M.A., PATTI A., PEDOTTI S., BARBERIS A., DEDOLA S., FARINA, SERRA P.A., ROCCHITTA G., RUZZA P., GAZZIERO, CARTA P., FOIS X., and PANTALEONI R.A. DELOGU G..
- Abstract
Hydroxylated biphenyl moiety is embedded in many structures of bioactive natural products. Some of them are present in compounds of high biological relevance like ellagitannins, vancomicin, biphenomicins, others, structurally less sophisticated, are natural occurring dimers of 4-substituted 2-methoxyphenols, e.g. guaiacyl unit. In our continuing study on phenols and their C2-symmetry dimers serving as the basis for the generation of ligands for functionally and structurally discreet biological receptors1, we have prepared a small collection of natural and natural-like hydroxylated biphenyls and monomers generally bearing a guaiacyl unit as main motif. Dimers have been prepared by C-C coupling reaction with inorganic oxidizing reagents starting from the corresponding monomer or functionalized from commercial 4,4?-dihydroxybiphenyl 9. Unsaturated monomer and dimers have been prepared by Claisen-Schimdt condensation of vanillin and vanillin dimer, respectively, with the corresponding ketone. Biphenyl 9 and compound 8 are known to be in vitro inhibitors of tyrosinase, a key enzyme in melanine biosynthesis involved in determining the colour of mammalian skin and hair, in unfavorable enzymatic browning of plant-derived foods and in insects molting process. Tyrosinase inhibitory activity have been detected via spectrophotometric assay in compounds, 1, 2, 4, 7, 10, 11 and 12, structurally related to 9 and 8, and in insects molting trial. Viability (80%) of compounds 1, 2, 4, 7, 8 and 10 in PC12 cells, a neuronal cell model, have been observed at concentration > 10 uM. In order to improve the biological activity of the guaiacyl unit present in phenols and C2-dimers1, we have planned to introduce a ferrocene unit because of the promising results observed in medicinal field when a metallocene moiety is embedded with bioactive compounds. Their electrochemical potential and cytotoxic activity in PC12 cells have been evaluated in comparison with data of the corresponding compounds lacking in ferrocene unit. All ferrocenylchalcones showed a reversible behavior, but not the saturated analog of compound 6.
- Published
- 2014
8. Un sistema telemetrico a bassissimo costo per la determinazione elettrochimica della vitamina C nel succo darancia fresco e in altri prodotti naturali
- Author
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Barberis A., Bazzu G., Calia G., Mura D., Rocchitta G., Migheli M., Schirra M., and Serra P.A.
- Published
- 2011
9. A new ultra -low-cost telemetric system for a rapid electrochemical detection of vitamin c in fresh orange juice and other natural products
- Author
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Barberis A., Bazzu G., Calia G., Rocchitta G., Migheli R., Schirra M., and Serra P.A.
- Published
- 2009
10. Underserved populations and bacterial and protozoal sexually transmitted infections: a lost health-care opportunity.
- Author
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FIORE, V., LATTE, G., MADEDDU, G., GALLERI, G., ROCCHITTA, G., NUVOLI, S., CALVISI, D., BAGELLA, P., MANETTI, R., SERRA, P. A., SPANU, A., and BABUDIERI, S.
- Abstract
OBJECTIVE: The purpose of our review is an update about the burden of sexually transmitted infections (STIs) among various types of underserved populations, such as migrants, substance abusers, homeless and incarcerated inmates. First-line test and treatment based on the latest available evidence according to the revised guidelines of Centers for Disease Control and Prevention have also been considered. MATERIALS AND METHODS: We performed a comprehensive research using scientific databases such as Medline and Pubmed, followed by a review of citations and reference list. A consultation with other experts in the management of the various subpopulations was also conducted. RESULTS: Health-care is often influenced by social determinants, which play a vital role in the diffusion of STIs. The consequence is a socio-economical and ethnic disparity in the rate of STIs. Early screening and treatment of STIs should be implemented in clinical practice, starting from marginalized social groups, which are the most affected by this health problem. CONCLUSIONS: In the literature, there are very few papers containing information on STIs prevalence in various types of underserved populations, such as migrants, substance abusers, homeless and incarcerated inmates. The availability of more accurate epidemiological data is needed. In these groups, the most relevant barrier is the lower perception of health-care need, with an underestimation of risk and symptoms of STIs, causing a retard of diagnosis and healthcare provision and use. For these populations, targeted interventions are needed, particularly on unaware people, responsible for most STIs transmissions. [ABSTRACT FROM AUTHOR]
- Published
- 2017
11. The burden of HIV-associated neurocognitive disorder (HAND) in post-HAART era: a multidisciplinary review of the literature.
- Author
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CARUANA, G., VIDILI, G., SERRA, P. A., BAGELLA, P., SPANU, A., FIORE, V., CALVISI, D. F., MANETTI, R., ROCCHITTA, G., NUVOLI, S., BABUDIERI, S., SIMILE, M. M., and MADEDDU, G.
- Abstract
OBJECTIVE: The purpose of the present multidisciplinary review is to give an updated insight into the most recent findings regarding the pathophysiology, diagnosis and therapeutics of HIV-associated neurocognitive disorder (HAND). MATERIALS AND METHODS: We performed a comprehensive search, through electronic databases (Pubmed - MEDLINE) and search engines (Google Scholar), of peer-reviewed publications (articles and reviews) and conferences proceedings on HAND pathophysiology, diagnosis, and therapy, from 1999 to 2016. RESULTS: It seems to be increasingly clear that neurodegeneration in HIV-1 affected patients is a multi-faceted disease involving numerous factors, from chronic inflammation to central nervous system (CNS) compartmentalization of HIV. Diagnosis of HAND may benefit from both laboratory analysis and advanced specific neuroimaging techniques. As regards HAND therapy, modified HAART combinations and simplification strategies have been tested, while novel exciting frontiers seem to involve the use of nanoparticles with the ability to cross the Blood-Brain Barrier (BBB). CONCLUSIONS: Albeit highly active antiretroviral therapy (HAART) allowed a major decrease in morbidity and mortality for AIDS patients, CNS involvement still represents a challenge in HIV patients even today, affecting up to 50% of patients with access to combination antiretroviral therapy (cART). Future studies will have to focus on CNS compartmentalization drugs' ability to penetrate and suppress viral replication in this compartment, and on new approaches to reduce HIV-associated neuroinflammation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
12. Signalling pathways in the nitric oxide and iron-induced dopamine release in the striatum of freely moving rats: role of extracellular Ca2+ and L-type Ca2+ channels
- Author
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Rocchitta, G, Migheli, R, Mura, Mp, Grella, G, Esposito, G, Marchetti, Bianca Maria, Miele, E, Desole, Ms, and Serra, Pa
- Published
- 2005
13. Glucorticoid receptor deficiency increases vulnerability of the nigrostriatal dopaminergic system: critical role of glial nitric oxide
- Author
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Morale, Mc, Serra, Pa, Delogu, Mr, Migheli, R, Rocchitta, G, Tirolo, C, Caniglia, S, Testa, N, L'Episcopo, F, Gennuso, F, Scoto, Gm, Barden, N, Miele, E, Desole, Ms, and Marchetti, Bianca Maria
- Published
- 2004
14. Direct monitoring of ethanol in the brain
- Author
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Rocchitta, G, primary and Serra, PA, primary
- Published
- 2013
- Full Text
- View/download PDF
15. The burden of HIV-Associated neurocognitive disorder (HAND) in post-HAART era: Amultidisciplinary review of the literature
- Author
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Caruana G, Vidili G, Pa, Serra, Bagella P, Spanu A, Fiore V, Df, Calvisi, Manetti R, Rocchitta G, Susanna Maria F. NUVOLI, Babudieri S, Mm, Simile, and Madeddu G
- Subjects
AIDS Dementia Complex ,Cost of Illness ,Antiretroviral Therapy, Highly Active ,Humans - Abstract
The purpose of the present multidisciplinary review is to give an updated insight into the most recent findings regarding the pathophysiology, diagnosis and therapeutics of HIV-associated neurocognitive disorder (HAND).We performed a comprehensive search, through electronic databases (Pubmed - MEDLINE) and search engines (Google Scholar), of peer-reviewed publications (articles and reviews) and conferences proceedings on HAND pathophysiology, diagnosis, and therapy, from 1999 to 2016.It seems to be increasingly clear that neurodegeneration in HIV-1 affected patients is a multi-faceted disease involving numerous factors, from chronic inflammation to central nervous system (CNS) compartmentalization of HIV. Diagnosis of HAND may benefit from both laboratory analysis and advanced specific neuroimaging techniques. As regards HAND therapy, modified HAART combinations and simplification strategies have been tested, while novel exciting frontiers seem to involve the use of nanoparticles with the ability to cross the Blood-Brain Barrier (BBB).Albeit highly active antiretroviral therapy (HAART) allowed a major decrease in morbidity and mortality for AIDS patients, CNS involvement still represents a challenge in HIV patients even today, affecting up to 50% of patients with access to combination antiretroviral therapy (cART). Future studies will have to focus on CNS compartmentalization, drugs' ability to penetrate and suppress viral replication in this compartment, and on new approaches to reduce HIV-associated neuroinflammation.
16. A study on the role of nitric oxide and iron in 3-morpholinosydnonimine-induced increases in dopamine release in the striatum of freely moving rats
- Author
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Serra, P. A., Rocchitta, G., Esposito, G., Delogu, M. R., Rossana MIGHELI, Miele, E., Desole, M. S., and Miele, M.
- Subjects
Male ,Dose-Response Relationship, Drug ,Metalloporphyrins ,Dopamine ,Iron ,Movement ,Homovanillic Acid ,Ascorbic Acid ,Free Radical Scavengers ,Deferoxamine ,Nitric Oxide ,Corpus Striatum ,Acetylcysteine ,Rats ,Uric Acid ,Dialysis Solutions ,Molsidomine ,Papers ,3,4-Dihydroxyphenylacetic Acid ,Animals ,Nitric Oxide Donors ,Rats, Wistar - Abstract
1. We showed previously that interaction between NO and iron (II), both released following the decomposition of sodium nitroprusside (SNP), accounted for the late SNP-induced dopamine (DA) increase in dialysates from the striatum of freely moving rats; in addition, we showed that co-infusion of iron (II) with the NO-donor S-nitroso-N-acetylpenicillamine mimicked SNP effects on striatal DA release. 2. In the present study, intrastriatal co-infusion of iron (II) (given as FeSO(4), 1 mM for 40 min) with the NO-donor and potential peroxynitrite generator 3-morpholinosydnonimine (SIN-1) (0.2, 0.5, 1.0 or 5.0 mM for 180 min), potentiated the SIN-1-induced increase in DA concentration in dialysates from the striatum of freely moving rats. Neither alone nor associated with iron (II) did SIN-1 induce changes in dialysate ascorbic acid or uric acid concentrations. 3. Neither co-infusion of a superoxide dismutase mimetic nor uric acid affected SIN-1-induced increases in dialysate DA concentration. 4. Infusion of the iron chelator deferoxamine (0.2 mM for 180 min) decreased dialysate DA and attenuated SIN-1-induced increases in dialysate DA concentrations. 5. These results suggest that iron plays a key role in SIN-1-induced release of striatal DA and do not support any role for either peroxynitrite or superoxide anion in SIN-1-induced release of striatal DA.
17. Analysis of 3-morpholinosydnonimine and sodium nitroprusside effects on dopamine release in the striatum of freely moving rats: Role of nitric oxide, iron and ascorbic acid
- Author
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Serra, P. A., Esposito, G., Delogu, M. R., Rossana MIGHELI, Rocchitta, G., Grella, G., Miele, E., Miele, M., and Desole, M. S.
18. α-synuclein- and MPTP-generated rodent models of parkinson's disease and the study of extracellular striatal dopamine dynamics: A microdialysis approach
- Author
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Bazzu, G., Calia, G., Puggioni, G., Spissu, Y., Rocchitta, G., Debetto, P., Grigoletto, J., Zusso, M., Rossana MIGHELI, Serra, P. A., Desole, M. S., and Miele, E.
19. Underserved populations and bacterial and protozoal sexually transmitted infections: a lost health-care opportunity
- Author
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Fiore, V., Latte, G., Giordano MADEDDU, Galleri, G., Rocchitta, G., Nuvoli, S., Calvisi, D., Bagella, P., Manetti, R., Serra, P. A., Spanu, A., and Babudieri, S.
- Subjects
Male ,Transients and Migrants ,Databases, Factual ,Substance-Related Disorders ,Sexual Behavior ,Ill-Housed Persons ,Sexually Transmitted Diseases ,Humans ,Female ,Delivery of Health Care ,Anti-Bacterial Agents - Abstract
The purpose of our review is an update about the burden of sexually transmitted infections (STIs) among various types of underserved populations, such as migrants, substance abusers, homeless and incarcerated inmates. First-line test and treatment based on the latest available evidence according to the revised guidelines of Centers for Disease Control and Prevention have also been considered.We performed a comprehensive research using scientific databases such as Medline and Pubmed, followed by a review of citations and reference list. A consultation with other experts in the management of the various subpopulations was also conducted.Health-care is often influenced by social determinants, which play a vital role in the diffusion of STIs. The consequence is a socio-economical and ethnic disparity in the rate of STIs. Early screening and treatment of STIs should be implemented in clinical practice, starting from marginalized social groups, which are the most affected by this health problem.In the literature, there are very few papers containing information on STIs prevalence in various types of underserved populations, such as migrants, substance abusers, homeless and incarcerated inmates. The availability of more accurate epidemiological data is needed. In these groups, the most relevant barrier is the lower perception of health-care need, with an underestimation of risk and symptoms of STIs, causing a retard of diagnosis and health-care provision and use. For these populations, targeted interventions are needed, particularly on unaware people, responsible for most STIs transmissions.
20. Sustainable Electropolymerization of Zingerone and Its C2 Symmetric Dimer for Amperometric Biosensor Films.
- Author
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Caval M, Dettori MA, Carta P, Dallocchio R, Dessì A, Marceddu S, Serra PA, Fabbri D, and Rocchitta G
- Subjects
- Glutamic Acid, Polymers, Guaiacol, Ascorbic Acid
- Abstract
Polymeric permselective films are frequently used for amperometric biosensors to prevent electroactive interference present in the target matrix. Phenylenediamines are the most commonly used for the deposition of shielding polymeric films against interfering species; however, even phenolic monomers have been utilized in the creation of these films for microsensors and biosensors. The purpose of this paper is to evaluate the performances of electrosynthesized polymers, layered by means of constant potential amperometry (CPA), of naturally occurring compound zingerone (ZING) and its dimer dehydrozingerone (ZING DIM), which was obtained by straight oxidative coupling reaction. The polymers showed interesting shielding characteristics against the main interfering species, such as ascorbic acid (AA): actually, polyZING exhibited an AA shielding aptitude comprised between 77.6 and 99.6%, comparable to that obtained with PPD. Moreover, a marked capability of increased monitoring of hydrogen peroxide (HP), when data were compared with bare metal results, was observed. In particular, polyZING showed increases ranging between 55.6 and 85.6%. In the present work, the molecular structures of the obtained polymers have been theorized and docking analyses were performed to understand their peculiar characteristics better. The structures were docked using the Lamarckian genetic algorithm (LGA). Glutamate biosensors based on those polymers were built, and their performances were compared with biosensors based on PPD, which is the most widespread polymer for the construction of amperometric biosensors.
- Published
- 2023
- Full Text
- View/download PDF
21. New perspective for an old drug: Can naloxone be considered an antioxidant agent?
- Author
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Migheli R, Lostia G, Galleri G, Rocchitta G, Serra PA, Campesi I, Bassareo V, Acquas E, and Peana AT
- Abstract
Background: Experimental evidence indicates that Naloxone (NLX) holds antioxidant properties. The present study aims at verifying the hypothesis that NLX could prevent oxidative stress induced by hydrogen peroxide (H
2 O2 ) in PC12 cells., Methods: To investigate the antioxidant effect of NLX, initially, we performed electrochemical experiments by means of platinum-based sensors in a cell-free system. Subsequently, NLX was tested in PC12 cells on H2 O2 -induced overproduction of intracellular levels of reactive-oxygen-species (ROS), apoptosis, modification of cells' cycle distribution and damage of cells' plasma membrane., Results: This study reveals that NLX counteracts intracellular ROS production, reduces H2 O2 -induced apoptosis levels, and prevents the oxidative damage-dependent increases of the percentage of cells in G2/M phase. Likewise, NLX protects PC12 cells from H2 O2 - induced oxidative damage, by preventing the lactate dehydrogenase (LDH) release. Moreover, electrochemical experiments confirmed the antioxidant properties of NLX., Conclusion: Overall, these findings provide a starting point for studying further the protective effects of NLX on oxidative stress., Competing Interests: The authors have no conflict(s) of interest to declare., (© 2023 The Authors.)- Published
- 2023
- Full Text
- View/download PDF
22. Inhibitory Effect of Curcumin-Inspired Derivatives on Tyrosinase Activity and Melanogenesis.
- Author
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Rocchitta G, Rozzo C, Pisano M, Fabbri D, Dettori MA, Ruzza P, Honisch C, Dallocchio R, Dessì A, Migheli R, Serra P, and Delogu G
- Subjects
- Humans, Animals, Rats, Melanins, Arbutin, Molecular Docking Simulation, Hydrogen Peroxide, Monophenol Monooxygenase, Curcumin pharmacology
- Abstract
Tyrosinase is a well-known copper-containing metalloenzyme typically involved in the synthesis of melanin. Recently, curcumin and several synthetic derivatives have been recognized as tyrosinase inhibitors with interesting anti-melanogenic therapeutic activity. In this study, three curcumin-inspired compounds 1 , 6 and 7 were prepared in yields ranging from 60 to 88 % and spectrophotometric, electrochemical, in vitro and in silico analyses were carried out. The viability of PC12 cells, a rat pheochromocytoma derived-cell line, with compounds 1 , 6 and 7 , showed values around 80% at 5 µM concentration. In cell proliferation assays, compounds 1 , 6 and 7 did not show significant toxicity on fibroblasts nor melanoma cells up to 10 µM with viability values over 90%. The inhibition of tyrosinase activity was evaluated both by a UV-Vis spectroscopic method at two different concentrations, 0.2 and 2.0 µM, and by amperometric assay with IC
50 for compounds 1 , 6 and 7 ranging from 11 to 24 nM. Melanin content assays on human melanoma cells were performed to test the capability of compounds to inhibit melanin biosynthesis. All compounds exerted a decrease in melanin content, with compound 7 being the most effective by showing a melanogenesis inhibition up to four times greater than arbutin at 100 µM. Moreover, the antioxidant activity of the selected inhibitors was evaluated against H2 O2 in amperometric experiments, whereby compound 7 was about three times more effective compared to compounds 1 and 6 . The tyrosinase X-ray structure of Bacterium megaterium crystal was used to carry out molecular docking studies in the presence of compounds 1 , 6 and 7 in comparison with that of kojic acid and arbutin, two conventional tyrosinase inhibitors. Molecular docking of compounds 6 and 7 confirmed the high affinity of these compounds to tyrosinase protein.- Published
- 2022
- Full Text
- View/download PDF
23. Author Correction: Quality control methods in musculoskeletal tissue engineering: from imaging to biosensors.
- Author
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Zuncheddu D, Della Bella E, Schwab A, Petta D, Rocchitta G, Generelli S, Kurth F, Parrilli A, Verrier S, Rau JV, Fosca M, Maioli M, Serra PA, Alini M, Redl H, Grad S, and Basoli V
- Published
- 2021
- Full Text
- View/download PDF
24. Quality control methods in musculoskeletal tissue engineering: from imaging to biosensors.
- Author
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Zuncheddu D, Della Bella E, Schwab A, Petta D, Rocchitta G, Generelli S, Kurth F, Parrilli A, Verrier S, Rau JV, Fosca M, Maioli M, Serra PA, Alini M, Redl H, Grad S, and Basoli V
- Abstract
Tissue engineering is rapidly progressing toward clinical application. In the musculoskeletal field, there has been an increasing necessity for bone and cartilage replacement. Despite the promising translational potential of tissue engineering approaches, careful attention should be given to the quality of developed constructs to increase the real applicability to patients. After a general introduction to musculoskeletal tissue engineering, this narrative review aims to offer an overview of methods, starting from classical techniques, such as gene expression analysis and histology, to less common methods, such as Raman spectroscopy, microcomputed tomography, and biosensors, that can be employed to assess the quality of constructs in terms of viability, morphology, or matrix deposition. A particular emphasis is given to standards and good practices (GXP), which can be applicable in different sectors. Moreover, a classification of the methods into destructive, noninvasive, or conservative based on the possible further development of a preimplant quality monitoring system is proposed. Biosensors in musculoskeletal tissue engineering have not yet been used but have been proposed as a novel technology that can be exploited with numerous advantages, including minimal invasiveness, making them suitable for the development of preimplant quality control systems., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
25. Epidemiology, Clinical Aspects, Laboratory Diagnosis and Treatment of Rickettsial Diseases in the Mediterranean Area During COVID-19 Pandemic: A Review of the Literature.
- Author
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De Vito A, Geremia N, Mameli SM, Fiore V, Serra PA, Rocchitta G, Nuvoli S, Spanu A, Lobrano R, Cossu A, Babudieri S, and Madeddu G
- Abstract
The purpose of the present review is to give an update regarding the classification, epidemiology, clinical manifestation, diagnoses, and treatment of the Rickettsial diseases present in the Mediterranean area. We performed a comprehensive search, through electronic databases (Pubmed - MEDLINE) and search engines (Google Scholar), of peer-reviewed publications (articles, reviews, and books). The availability of new diagnostic tools, including Polymerase Chain Reaction and nucleotide sequencing has significantly modified the classification of intracellular bacteria, including the order Rickettsiales with more and more new Rickettsia species recognized as human pathogens. Furthermore, emerging Rickettsia species have been found in several countries and are often associated with unique clinical pictures that may challenge the physician in the early detection of the diseases. Rickettsial infections include a wide spectrum of clinical presentations ranging from a benign to a potentially life treating disease that requires prompt recognition and proper management. Recently, due to the spread of SARS-CoV-2 infection, the differential diagnosis with COVID-19 is of crucial importance. The correct understanding of the clinical features, diagnostic tools, and proper treatment can assist clinicians in the management of Rickettsioses in the Mediterranean area., Competing Interests: Competing interests: The authors declare no conflict of Interest.
- Published
- 2020
- Full Text
- View/download PDF
26. Synthesis and Studies of the Inhibitory Effect of Hydroxylated Phenylpropanoids and Biphenols Derivatives on Tyrosinase and Laccase Enzymes.
- Author
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Dettori MA, Fabbri D, Dessì A, Dallocchio R, Carta P, Honisch C, Ruzza P, Farina D, Migheli R, Serra PA, Pantaleoni RA, Fois X, Rocchitta G, and Delogu G
- Subjects
- Animals, Catalytic Domain, Cell Survival drug effects, Crystallography, X-Ray, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Hydroxylation, Laccase antagonists & inhibitors, Laccase metabolism, Models, Molecular, Monophenol Monooxygenase antagonists & inhibitors, Monophenol Monooxygenase metabolism, PC12 Cells, Propanols chemistry, Propanols pharmacology, Protein Conformation, Rats, Tenebrio drug effects, Tenebrio enzymology, Enzyme Inhibitors chemical synthesis, Laccase chemistry, Monophenol Monooxygenase chemistry, Phenol chemistry, Propanols chemical synthesis, Tenebrio growth & development
- Abstract
The impaired activity of tyrosinase and laccase can provoke serious concerns in the life cycles of mammals, insects and microorganisms. Investigation of inhibitors of these two enzymes may lead to the discovery of whitening agents, medicinal products, anti-browning substances and compounds for controlling harmful insects and bacteria. A small collection of novel reversible tyrosinase and laccase inhibitors with a phenylpropanoid and hydroxylated biphenyl core was prepared using naturally occurring compounds and their activity was measured by spectrophotometric and electrochemical assays. Biosensors based on tyrosinase and laccase enzymes were constructed and used to detect the type of protein-ligand interaction and half maximal inhibitory concentration (IC
50 ). Most of the inhibitors showed an IC50 in a range of 20-423 nM for tyrosinase and 23-2619 nM for laccase. Due to the safety concerns of conventional tyrosinase and laccase inhibitors, the viability of the new compounds was assayed on PC12 cells, four of which showed a viability of roughly 80% at 40 µM. In silico studies on the crystal structure of laccase enzyme identified a hydroxylated biphenyl bearing a prenylated chain as the lead structure, which activated strong and effective interactions at the active site of the enzyme. These data were confirmed by in vivo experiments performed on the insect model Tenebrio molitur .- Published
- 2020
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27. Real-time telemetry monitoring of oxygen in the central complex of freely-walking Gromphadorhina portentosa.
- Author
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Serra PA, Arrigo P, Bacciu A, Zuncheddu D, Deliperi R, Antón Viana D, Monti P, Varoni MV, Sotgiu MA, Bandiera P, and Rocchitta G
- Subjects
- Animals, Carbon Dioxide metabolism, Chloroform metabolism, Cockroaches metabolism, Equipment Design, Ethylamines metabolism, Male, Nitrogen metabolism, Software, Walking, Wireless Technology, Biosensing Techniques instrumentation, Cockroaches physiology, Oxygen analysis, Remote Sensing Technology instrumentation
- Abstract
A new telemetric system for the electrochemical monitoring of dissolved oxygen is showed. The device, connected with two amperometric sensors, has been successfully applied to the wireless detection of the extracellular oxygen in the central complex of freely-walking Gromphadorhina portentosa. The unit was composed of a potentiostat, a two-channel sensor conditioning circuit, a microprocessor module, and a wireless serial transceiver. The amperometric signals were digitalized and sent to a notebook using a 2.4 GHz transceiver while a serial-to-USB converter was connected to a second transceiver for completing the communication bridge. The software, running on the laptop, allowed to save and graph the oxygen signals. The electronics showed excellent stability and the acquired data was linear in a range comprised between 0 and -165 nA, covering the entire range of oxygen concentrations. A series of experiments were performed to explore the dynamics of dissolved oxygen by exposing the animals to different gases (nitrogen, oxygen and carbon dioxide), to low temperature and anesthetic agents (chloroform and triethylamine). The resulting data are in agreement with previous O2 changes recorded in the brain of awake rats and mice. The proposed system, based on simple and inexpensive components, can constitute a new experimental model for the exploration of central complex neurochemistry and it can also work with oxidizing sensors and amperometric biosensors., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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28. The Presence of Polysaccharides, Glycerol, and Polyethyleneimine in Hydrogel Enhances the Performance of the Glucose Biosensor.
- Author
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Fois M, Arrigo P, Bacciu A, Monti P, Marceddu S, Rocchitta G, and Serra PA
- Subjects
- Biosensing Techniques, Enzyme Stability, Enzymes, Immobilized chemistry, Glucose chemistry, Hydrogels chemistry, Kinetics, Polyethyleneimine, Time Factors, Glucose analysis, Glycerol chemistry, Polysaccharides chemistry
- Abstract
The use of amperometric biosensors has attracted particular attention in recent years, both from researchers and from companies, as they have proven to be low-cost, reliable, and very sensitive devices, with a wide range of uses in different matrices. The continuous development of amperometric biosensors, since their use involves an enzyme, is specifically aimed at keeping and increasing the catalytic properties of the loaded protein, so as to be able to use the same device over time. The present study aimed to investigate the impact of glycerol and polysaccharides, in the presence of polycationic substances to constitute a hydrogel, in enhancing the enzymatic and analytic performance of a glucose biosensor. Initially, it was possible to verify how the deposition of the starch-based hydrogel, in addition to allowing the electropolymerization of the poly(p-phenylenediamine) polymer and the maintenance of its ability to shield the ascorbic acid, did not substantially limit the permeability towards hydrogen peroxide. Moreover, different biosensor designs, loading a mixture containing all the components (alone or in combination) and the enzyme, were tested in order to evaluate the changes of the apparent enzyme kinetic parameters, such as V
MAX and KM , and analytical response in terms of Linear Region Slope, highlighting how the presence of all components (starch, glycerol, and polyethyleneimine) were able to substantially enhance the performance of the biosensors. The surface analysis of the biosensors was performed by scanning electron microscope (SEM). More, it was shown that the same performances were kept unchanged for seven days, proving the suitability of this biosensor design for short- and mid-term use.- Published
- 2019
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29. Low-Temperature Storage Improves the Over-Time Stability of Implantable Glucose and Lactate Biosensors.
- Author
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Puggioni G, Calia G, Arrigo P, Bacciu A, Bazzu G, Migheli R, Fancello S, Serra PA, and Rocchitta G
- Subjects
- Dry Ice, Equipment Design, Kinetics, Time Factors, Biosensing Techniques methods, Cold Temperature, Glucose analysis, Lactic Acid analysis, Preservation, Biological
- Abstract
Molecular biomarkers are very important in biology, biotechnology and even in medicine, but it is quite hard to convert biology-related signals into measurable data. For this purpose, amperometric biosensors have proven to be particularly suitable because of their specificity and sensitivity. The operation and shelf stability of the biosensor are quite important features, and storage procedures therefore play an important role in preserving the performance of the biosensors. In the present study two different designs for both glucose and lactate biosensor, differing only in regards to the containment net, represented by polyurethane or glutharaldehyde, were studied under different storage conditions (+4, -20 and -80 °C) and monitored over a period of 120 days, in order to evaluate the variations of kinetic parameters, as V
MAX and KM , and LRS as the analytical parameter. Surprisingly, the storage at -80 °C yielded the best results because of an unexpected and, most of all, long-lasting increase of VMAX and LRS, denoting an interesting improvement in enzyme performances and stability over time. The present study aimed to also evaluate the impact of a short-period storage in dry ice on biosensor performances, in order to simulate a hypothetical preparation-conservation-shipment condition.- Published
- 2019
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30. Use of β-cyclodextrin as enhancer of ascorbic acid rejection in permselective films for amperometric biosensor applications.
- Author
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Monti P, Rocchitta G, Marceddu S, Dettori MA, Fabbri D, Jaoua S, Migheli Q, Delogu G, and Serra PA
- Subjects
- Biphenyl Compounds chemistry, Eugenol chemistry, Lignans chemistry, Polymers chemistry, Ascorbic Acid chemistry, Biosensing Techniques, Electrochemical Techniques, Glutamic Acid analysis, beta-Cyclodextrins chemistry
- Abstract
Interference rejection in amperometric biosensors can be more effective introducing some modifiers during electro-deposition of permselective film. Addition of β-cyclodextrin (βCD), a cyclic oligosaccharide composed of seven glucose units, to the ortho-phenylendiamine (oPD) monomer were already demonstrated to provide an enhancement in ascorbic acid (AA) rejection. Here we evaluated the improvement in permselectivity of poly-eugenol and poly-magnolol films electro-polymerized in presence of different amounts of βCD or eugenol-βCD inclusion complex for amperometric biosensor application. Starting from Pt-Ir wire as transducer several microsensors were covered with polymeric films doped with βCD-based modifiers through constant potential amperometry. Characterization of modified polymers was achieved by scanning electron microscopy and permselectivity analysis. Poly-magnolol film in combination with βCD showed a worsening in permselectivity compared to poly-magnolol alone. In contrast, the introduction of βCD-based modifier enhanced the interference rejection toward the archetypal interferent AA, while slightly affecting permeability toward H
2 O2 compared to the poly-eugenol without modifier. The AA rejection seems to be influenced by the availability of βCD cavity as well as film performance due to concentration of βCD-Eugenol inclusion complex. A poly-eugenol film co-polymerized with 2 mM βCD-eugenol inclusion complex showed a permselectivity equal to poly-orthophenylendiamine film (PPD), with a lower permeability to AA, likely to be related with a self-blocking mechanism. Based on these results, a biosensor for glutamate was constructed with a poly-eugenol doped with βCD-eugenol as permselective layer and its permselectivity, stability and lifetime were determined., (Copyright © 2018. Published by Elsevier B.V.)- Published
- 2018
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31. A MOF-based carrier for in situ dopamine delivery.
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Pinna A, Ricco' R, Migheli R, Rocchitta G, Serra PA, Falcaro P, Malfatti L, and Innocenzi P
- Abstract
MIL-88A (Fe) MOF crystals were nucleated and grown around a polymer core containing superparamagnetic nanoparticles to assemble a new class of biocompatible particles for magnetophoretic drug delivery of dopamine. The carrier enabled efficient targeted release, dopamine protection from oxidative damage, long-term delivery and improved drug delivery cost-efficiency. After loading, dopamine was stable within the carrier and did not undergo oxidation. Drug release monitoring via spectrofluorimetry revealed a shorter burst effect and higher release efficiency than silica based carriers. The in vitro cytotoxicity at different MOF concentrations and sizes was assessed using PC12 cells as the neuronal cell model. The drug was directly uptaken into the PC12 cells avoiding possible side effects due to oxidation occurring in the extracellular environment., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
- Published
- 2018
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32. The role of molecular breast imaging in predicting complete tumor response to treatment and residual tumor extent following neoadjuvant therapy.
- Author
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Nuvoli S, Galassi S, Gelo I, Rocchitta G, Fancellu A, Serra PA, Madeddu G, and Spanu A
- Subjects
- Breast Neoplasms surgery, Female, Humans, Predictive Value of Tests, Radionuclide Imaging, Retrospective Studies, Treatment Outcome, Breast Neoplasms drug therapy, Molecular Imaging methods, Neoadjuvant Therapy methods, Neoplasm, Residual diagnostic imaging
- Abstract
The aim of the present study was to investigate the usefulness of molecular breast imaging (MBI) in predicting complete tumor response to treatment and residual tumor extent following neoadjuvant therapy. A consecutive series of 43 female patients with large or locally advanced primary breast cancer, scheduled for surgery following neoadjuvant therapy, was retrospectively reviewed. Prior to surgery, all patients underwent MBI using a high‑resolution semiconductor‑based device for image acquisition. MBI data were correlated with surgical histopathological findings. Spearman's correlation coefficient was calculated to assess differences in residual tumor size with MBI and histopathological examination. From the images obtained using MBI, 7 patients were negative for residual tumors with pathological complete response (specificity, 100%) and positive in 34/36 patients with residual disease (sensitivity, 94.4%), including 26/27 patients with unifocal and 8/9 patients with multicentric/multifocal tumors, 5 of which exhibited multiple microscopic foci scattered in a fibrotic area. Overall accuracy was 95.3% and the positive predictive value (PPV) and negative predictive value (NPV) were 100 and 77.8%, respectively. MBI was false‑negative in one patient with a 2.5‑cm invasive ductal carcinoma located close to the chest wall and in one patient with microscopic foci of epithelial carcinoma. In the patients with unifocal residual tumors, correlation of tumor size between MBI and histopathology was r=0.981 (P<0.0001); however, MBI overestimated the number of lesions in one of these cases. In the patients with multifocal/multicentric tumors, MBI adequately assessed residual tumor extent in 5/8 positive cases, overestimating the number of lesions in one case and underestimating tumor extent in 2 further cases with microscopic foci scattered in a fibrotic area. MBI proved to be a highly accurate diagnostic tool in predicting complete tumor response to neoadjuvant therapy and residual tumor extent, correlating with surgical histopathological findings in 86% of overall cases. A positive result was always associated with the presence of residual disease and MBI tumor size was strongly correlated with histopathological analysis mainly in unifocal residual tumors.
- Published
- 2018
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33. Synthesis of Nitric Oxide Donors Derived from Piloty's Acid and Study of Their Effects on Dopamine Secretion from PC12 Cells.
- Author
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Sanna D, Rocchitta G, Serra M, Abbondio M, Serra PA, Migheli R, De Luca L, Garribba E, and Porcheddu A
- Abstract
This study investigated the mechanisms and kinetics of nitric oxide (NO) generation by derivatives of Piloty's acid (NO-donors) under physiological conditions. In order to qualitatively and quantitatively measure NO release, electron paramagnetic resonance (EPR) was carried out with NO spin trapping. In addition, voltammetric techniques, including cyclic voltammetry and constant potential amperometry, were used to confirm NO release from Piloty's acid and its derivatives. The resulting data showed that Piloty's acid derivatives are able to release NO under physiological conditions. In particular, electron-withdrawing substituents favoured NO generation, while electron-donor groups reduced NO generation. In vitro microdialysis, performed on PC12 cell cultures, was used to evaluate the dynamical secretion of dopamine induced by the Piloty's acid derivatives. Although all the studied molecules were able to induce DA secretion from PC12, only those with a slow release of NO have not determined an autoxidation of DA itself. These results confirm that the time-course of NO-donors decomposition and the amount of NO released play a key role in dopamine secretion and auto-oxidation. This information could drive the synthesis or the selection of compounds to use as potential drugs for the therapy of Parkinson's disease (PD)., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
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34. Is catalase involved in the effects of systemic and pVTA administration of 4-methylpyrazole on ethanol self-administration?
- Author
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Peana AT, Pintus FA, Bennardini F, Rocchitta G, Bazzu G, Serra PA, Porru S, Rosas M, and Acquas E
- Subjects
- Animals, Catalase antagonists & inhibitors, Conditioning, Operant drug effects, Conditioning, Operant physiology, Fomepizole, Hydrogen Peroxide antagonists & inhibitors, Hydrogen Peroxide metabolism, Injections, Intraventricular, Male, Rats, Rats, Wistar, Self Administration, Antidotes administration & dosage, Catalase metabolism, Ethanol administration & dosage, Pyrazoles administration & dosage, Ventral Tegmental Area drug effects, Ventral Tegmental Area enzymology
- Abstract
The oxidative metabolism of ethanol into acetaldehyde involves several enzymes, including alcohol dehydrogenase (ADH) and catalase-hydrogen peroxide (H
2 O2 ). In this regard, while it is well known that 4-methylpyrazole (4-MP) acts by inhibiting ADH in the liver, little attention has been placed on its ability to interfere with fatty acid oxidation-mediated generation of H2 O2 , a mechanism that may indirectly affect catalase whose enzymatic activity requires H2 O2 . The aim of our investigation was twofold: 1) to evaluate the effect of systemic (i.p. [intraperitoneal]) and local (into the posterior ventral tegmental area, pVTA) administration of 4-MP on oral ethanol self-administration, and 2) to assess ex vivo whether or not systemic 4-MP affects liver and brain H2 O2 availability. The results show that systemic 4-MP reduced ethanol but not acetaldehyde or saccharin self-administration, and decreased the ethanol deprivation effect. Moreover, local intra-pVTA administration of 4-MP reduced ethanol but not saccharin self-administration. In addition, although unable to affect basal catalase activity, systemic administration of 4-MP decreased H2 O2 availability both in liver and in brain. Overall, these results indicate that 4-MP interferes with ethanol self-administration and suggest that its behavioral effects could be due to a decline in catalase-H2 O2 system activity as a result of a reduction of H2 O2 availability, thus highlighting the role of central catalase-mediated metabolism of ethanol and further supporting the key role of acetaldehyde in the reinforcing properties of ethanol., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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35. 123I-ioflupane brain SPECT and 123I-MIBG cardiac planar scintigraphy combined use in uncertain parkinsonian disorders.
- Author
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Nuvoli S, Spanu A, Piras MR, Nieddu A, Mulas A, Rocchitta G, Galleri G, Serra PA, and Madeddu G
- Subjects
- 3-Iodobenzylguanidine, Aged, Aged, 80 and over, Diagnosis, Differential, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Nortropanes, Radiopharmaceuticals, Retrospective Studies, Brain diagnostic imaging, Heart diagnostic imaging, Multimodal Imaging, Parkinsonian Disorders classification, Parkinsonian Disorders diagnostic imaging, Tomography, Emission-Computed, Single-Photon
- Abstract
We evaluated the clinical usefulness of the combined use of I-ioflupane brain single photon emission computed tomography (SPECT) and I-metaiodobenzylguanidine (MIBG) cardiac scintigraphy in discriminating uncertain parkinsonism with vascular lesions in striatal nuclei at magnetic resonance imaging (MRI). Forty-three consecutive patients with uncertain parkinsonism and vascular lesions at MRI in striatal nuclei were retrospectively evaluated; the uncertain differential diagnosis was between Parkinson's disease and vascular parkinsonism (PD/VP) in 22 patients, between PD and other neurodegenerative parkinsonism (PD/PS) in 11 patients and between Lewy body dementia and Alzheimer disease (LBD/AD) in the remaining 10 cases. All patients underwent I-ioflupane SPECT with striatal dopaminergic activity determination as binding potentials (BP; cut-off: 3.3). I-MIBG cardiac planar scintigraphy was performed 2 weeks later, in early (15 minutes) and delayed (240 minutes) phases also calculating heart to mediastinum (H/M) ratio (cut-off: 1.56). I-Ioflupane uptake was normal in 9 patients with BP values >3.3, while it was reduced in 34/43 cases with BP values <3.3 at least in one of the striatal nuclei. I-MIBG uptake was normal in 21/43 patients (5 of whom with normal and 16 with I-ioflupane striatal defects) showing the H/M ratio >1.56 in all cases; the uptake was reduced in 22/43 cases, (4 of whom were normal and 18 were with I-ioflupane striatal defects) with the H/M ratio <1.56 in all cases. No statistical differences were found when early and delayed H/M ratios were mutually compared. Combining the 2 radioisotopic procedures, a more reliable diagnosis was achieved in 39/43 cases properly classifying 13 PD, 10 VP, 7 PS, 5 LBD, and 4 AD. However, the diagnosis remained uncertain in four patients with normal I-ioflupane and reduced I-MIBG uptake. The results of the present study confirmed that in uncertain parkinsonian syndromes associated with vascular lesions in striatal nuclei, brain I-ioflupane SPECT alone did not prove able to discriminate between the different forms of disease. Only the association with I-MIBG cardiac scintigraphy, also with the early acquisition alone, allowed the most appropriate diagnosis in 90.7% of our cases. However, patients with normal I-ioflupane and reduced I-I-MIBG uptakes need a close clinical and instrumental follow-up as sympathetic damage could precede striatal disorders in the early stage of PD and LBD.
- Published
- 2017
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36. Development of a biosensor telemetry system for monitoring fermentation in craft breweries.
- Author
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Farina D, Zinellu M, Fanari M, Porcu MC, Scognamillo S, Puggioni GMG, Rocchitta G, Serra PA, and Pretti L
- Subjects
- Beer analysis, Biosensing Techniques methods, Ethanol analysis, Fermentation, Food Industry, Glucose analysis, Telemetry
- Abstract
The development and applications of biosensors in the food industry has had a rapid grown due to their sensitivity, specificity and simplicity of use with respect to classical analytical methods. In this study, glucose and ethanol amperometric biosensors integrated with a wireless telemetry system were developed and used for the monitoring of top and bottom fermentations in beer wort samples. The collected data were in good agreement with those obtained by reference methods. The simplicity of construction, the low cost and the short time of analysis, combined with easy interpretation of the results, suggest that these devices could be a valuable alternative to conventional methods for monitoring fermentation processes in the food industry., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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37. Real-time monitoring of glucose and phenols intestinal absorption through an integrated Caco-2TC7cells/biosensors telemetric device: Hypoglycemic effect of fruit phytochemicals.
- Author
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Barberis A, Garbetta A, Cardinali A, Bazzu G, D'Antuono I, Rocchitta G, Fadda A, Linsalata V, D'Hallewin G, Serra PA, and Minervini F
- Subjects
- Blueberry Plants chemistry, Cell Line, Equipment Design, Fruit and Vegetable Juices analysis, Humans, Hyperglycemia drug therapy, Hyperglycemia metabolism, Hypoglycemic Agents chemistry, Lythraceae chemistry, Phloretin chemistry, Phlorhizin chemistry, Telemetry instrumentation, Biosensing Techniques instrumentation, Glucose metabolism, Hypoglycemic Agents pharmacology, Intestinal Absorption drug effects, Phenols metabolism, Phloretin pharmacology, Phlorhizin pharmacology
- Abstract
An integrated device for real-time monitoring of glucose and phenols absorption, that consists of a sensors/biosensors system (SB) and a Caco-2TC7 human intestinal cell culture, is described in this study. The SB is composed of a glucose oxidase-based biosensor, a sentinel platinum sensor, a laccase/tyrosinase-based biosensor and a sentinel carbon sensor, all located in the basolateral compartment (BC) of a cell culture plate. Caco-2TC7 cells, differentiated on culture inserts, separated the apical compartment that simulates the intestinal lumen, from the BC which represented the bloodstream. The system recorded currents relative to glucose (1mM) absorption, obtaining bioavailability values (5.1%) comparable to HPLC analysis (4.8%). Phloridzin and phloretin, specific phenolic inhibitors of SGLT1 and GLUT2 glucose transporters, reduced the glucose transport of almost 10 times. They were minimally absorbed in the BC with a bioavailability of 0.13% and 0.49% respectively. The hypoglycemic potential of blueberry and pomegranate juices was also studied. In particular, the amount of glucose absorbed through the Caco-2TC7 monolayer was 8‰ for pomegranate and 1.7‰ for blueberry, demonstrating the potential hypoglycemic effect of the juices. Polyphenols absorption was also monitored by the SB and an increase was recorded during the first 50min in presence of both blueberry and pomegranate juices, then a constant decrease occurred. The proposed device has been developed as innovative tool for the dynamic monitoring of natural compounds effects on glucose absorption, in order to manage postprandial hyperglycemia., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
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38. Hydroxylated biphenyls as tyrosinase inhibitor: A spectrophotometric and electrochemical study.
- Author
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Ruzza P, Serra PA, Fabbri D, Dettori MA, Rocchitta G, and Delogu G
- Subjects
- Agaricales enzymology, Biocatalysis, Electrochemistry, Hydroxylation, Kinetics, Models, Molecular, Monophenol Monooxygenase chemistry, Monophenol Monooxygenase metabolism, Oxidation-Reduction, Protein Conformation, Spectrophotometry, Ultraviolet, Biphenyl Compounds chemistry, Biphenyl Compounds pharmacology, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Monophenol Monooxygenase antagonists & inhibitors
- Abstract
A small collection of C
2 -symmetry hydroxylated biphenyls was prepared by straightforward methods and the capability to act as inhibitors of tyrosinase has been evaluated by both spectrophotometric and electrochemical assays. Our attention was focused on the diphenolase activity of this enzyme characterized by the absence of the characteristic lag time of enzymatic reaction of its monophenolase activity. To this purpose, we evaluated the capability of tyrosinase to oxidize a natural o-diphenol substrate to o-quinone analyzing the changes in the UV-Vis spectrum of a solution of caffeic acid and the reduction of the cathodic current in a tyrosinase-biosensor, respectively. Results of both the methods were comparable. Most of the compounds possessed higher inhibitory activity compared to compound 1, a known hydroxylated biphenyl inhibitor of tyrosinase., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)- Published
- 2017
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39. Enzyme Biosensors for Biomedical Applications: Strategies for Safeguarding Analytical Performances in Biological Fluids.
- Author
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Rocchitta G, Spanu A, Babudieri S, Latte G, Madeddu G, Galleri G, Nuvoli S, Bagella P, Demartis MI, Fiore V, Manetti R, and Serra PA
- Subjects
- Body Fluids chemistry, Enzymes analysis, Biosensing Techniques methods
- Abstract
Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This article reviews the problems resulting from the interaction of enzyme-based amperometric biosensors with complex biological matrices containing the target analyte(s). One of the most challenging disadvantages of amperometric enzyme-based biosensor detection is signal reduction from fouling agents and interference from chemicals present in the sample matrix. This article, therefore, investigates the principles of functioning of enzymatic biosensors, their analytical performance over time and the strategies used to optimize their performance. Moreover, the composition of biological fluids as a function of their interaction with biosensing will be presented.
- Published
- 2016
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40. Neurological morphofunctional differentiation induced by REAC technology in PC12. A neuro protective model for Parkinson's disease.
- Author
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Maioli M, Rinaldi S, Migheli R, Pigliaru G, Rocchitta G, Santaniello S, Basoli V, Castagna A, Fontani V, Ventura C, and Serra PA
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors biosynthesis, Basic Helix-Loop-Helix Transcription Factors genetics, Cell Differentiation, Cell Line, Tumor, Cell Proliferation, Gene Expression Profiling, Nerve Growth Factor biosynthesis, Nerve Growth Factor genetics, Nerve Tissue Proteins biosynthesis, Nerve Tissue Proteins genetics, PC12 Cells, Rats, Tubulin biosynthesis, Tubulin genetics, Tyrosine 3-Monooxygenase metabolism, Deep Brain Stimulation methods, Dopaminergic Neurons cytology, Electric Stimulation Therapy methods, Neuroprotection physiology, Parkinson Disease therapy
- Abstract
Research for the use of physical means, in order to induce cell differentiation for new therapeutic strategies, is one of the most interesting challenges in the field of regenerative medicine, and then in the treatment of neurodegenerative diseases, Parkinson's disease (PD) included. The aim of this work is to verify the effect of the radio electric asymmetric conveyer (REAC) technology on the PC12 rat adrenal pheochromocytoma cell line, as they display metabolic features of PD. PC12 cells were cultured with a REAC regenerative tissue optimization treatment (TO-RGN) for a period ranging between 24 and 192 hours. Gene expression analysis of specific neurogenic genes, as neurogenin-1, beta3-tubulin and Nerve growth factor, together with the immunostaining analysis of the specific neuronal protein beta3-tubulin and tyrosine hydroxylase, shows that the number of cells committed toward the neurogenic phenotype was significantly higher in REAC treated cultures, as compared to control untreated cells. Moreover, MTT and Trypan blue proliferation assays highlighted that cell proliferation was significantly reduced in REAC TO-RGN treated cells. These results open new perspectives in neurodegenerative diseases treatment, particularly in PD. Further studies will be needed to better address the therapeutic potential of the REAC technology.
- Published
- 2015
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41. Effects of the neurotoxin MPTP and pargyline protection on extracellular energy metabolites and dopamine levels in the striatum of freely moving rats.
- Author
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Bazzu G, Rocchitta G, Migheli R, Alvau MD, Zinellu M, Puggioni G, Calia G, Mercanti G, Giusti P, Desole MS, and Serra PA
- Subjects
- Animals, Male, Rats, Rats, Wistar, Corpus Striatum metabolism, Dopamine metabolism, Energy Metabolism drug effects, MPTP Poisoning metabolism, Monoamine Oxidase Inhibitors therapeutic use, Pargyline therapeutic use
- Abstract
The neurotoxin MPTP is known to induce dopamine release and depletion of ATP in the striatum of rats. Therefore, we studied the changes induced by MPTP and pargyline protection both on striatal dopamine release and on extracellular energy metabolites in freely moving rats, using dual asymmetric-flow microdialysis. A dual microdialysis probe was inserted in the right striatum of rats. MPTP (25mg/kg, 15mg/kg, 10mg/kg) was intraperitoneally administered for three consecutive days. MAO-B inhibitor pargyline (15mg/kg) was systemically administered before neurotoxin administration. The first MPTP dose induced an increase in dialysate dopamine and a decrease of DOPAC levels in striatal dialysate. After the first neurotoxin administration, increases in striatal glucose, lactate, pyruvate, lactate/pyruvate (L/P) and lactate/glucose (L/G) ratios were observed. Subsequent MPTP administrations showed a progressive reduction of dopamine, glucose and pyruvate levels with a concomitant further increase in lactate levels and L/P and L/G ratios. At day 1, pargyline pre-treatment attenuated the MPTP-induced changes in all studied analytes. Starting from day 2, pargyline prevented the depletion of dopamine, glucose and pyruvate while reduced the increase of lactate, L/P ratio and L/G ratio. These in vivo results suggest a pargyline neuroprotection role against the MPTP-induced energetic impairment consequent to mitochondrial damage. This neuroprotective effect was confirmed by TH immunostaining of the substantia nigra., (© 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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42. Simultaneous telemetric monitoring of brain glucose and lactate and motion in freely moving rats.
- Author
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Rocchitta G, Secchi O, Alvau MD, Farina D, Bazzu G, Calia G, Migheli R, Desole MS, O'Neill RD, and Serra PA
- Subjects
- Animals, Biosensing Techniques, Male, Rats, Rats, Sprague-Dawley, Brain metabolism, Glucose metabolism, Lactates metabolism, Telemetry
- Abstract
A new telemetry system for simultaneous detection of extracellular brain glucose and lactate and motion is presented. The device consists of dual-channel, single-supply miniature potentiostat-I/V converter, a microcontroller unit, a signal transmitter, and a miniaturized microvibration sensor. Although based on simple and inexpensive components, the biotelemetry device has been used for accurate transduction of the anodic oxidation currents generated on the surface of implanted glucose and lactate biosensors and animal microvibrations. The device was characterized and validated in vitro before in vivo experiments. The biosensors were implanted in the striatum of freely moving animals and the biotelemetric device was fixed to the animal's head. Physiological and pharmacological stimulations were given in order to induce striatal neural activation and to modify the motor behavior in awake, untethered animals.
- Published
- 2013
- Full Text
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43. LRRK2 affects vesicle trafficking, neurotransmitter extracellular level and membrane receptor localization.
- Author
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Migheli R, Del Giudice MG, Spissu Y, Sanna G, Xiong Y, Dawson TM, Dawson VL, Galioto M, Rocchitta G, Biosa A, Serra PA, Carri MT, Crosio C, and Iaccarino C
- Subjects
- Amino Acid Substitution, Animals, Disease Models, Animal, Dopamine genetics, Dopamine metabolism, Humans, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2, Mice, Mutation, Missense, Neurons pathology, PC12 Cells, Parkinson Disease genetics, Parkinson Disease metabolism, Parkinson Disease pathology, Protein Serine-Threonine Kinases genetics, Protein Transport genetics, Rats, Receptors, Dopamine D1 genetics, Neurons metabolism, Protein Serine-Threonine Kinases metabolism, Receptors, Dopamine D1 metabolism
- Abstract
The leucine-rich repeat kinase 2 (LRRK2) gene was found to play a role in the pathogenesis of both familial and sporadic Parkinson's disease (PD). LRRK2 encodes a large multi-domain protein that is expressed in different tissues. To date, the physiological and pathological functions of LRRK2 are not clearly defined. In this study we have explored the role of LRRK2 in controlling vesicle trafficking in different cellular or animal models and using various readouts. In neuronal cells, the presence of LRRK2(G2019S) pathological mutant determines increased extracellular dopamine levels either under basal conditions or upon nicotine stimulation. Moreover, mutant LRRK2 affects the levels of dopamine receptor D1 on the membrane surface in neuronal cells or animal models. Ultrastructural analysis of PC12-derived cells expressing mutant LRRK2(G2019S) shows an altered intracellular vesicle distribution. Taken together, our results point to the key role of LRRK2 to control vesicle trafficking in neuronal cells.
- Published
- 2013
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44. Further in-vitro characterization of an implantable biosensor for ethanol monitoring in the brain.
- Author
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Secchi O, Zinellu M, Spissu Y, Pirisinu M, Bazzu G, Migheli R, Desole MS, O'Neill RD, Serra PA, and Rocchitta G
- Subjects
- Animals, Biosensing Techniques methods, Enzymes metabolism, Hydrogen-Ion Concentration, Oxygen, Rats, Temperature, Biosensing Techniques instrumentation, Brain Chemistry, Ethanol analysis, Models, Theoretical, Prostheses and Implants
- Abstract
Ethyl alcohol may be considered one of the most widespread central nervous system (CNS) depressants in Western countries. Because of its toxicological and neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In a previous study, we described the development and characterization of an implantable biosensor successfully used for the real-time detection of ethanol in the brain of freely-moving rats. The implanted biosensor, integrated in a low-cost telemetry system, was demonstrated to be a reliable device for the short-time monitoring of exogenous ethanol in brain ECF. In this paper we describe a further in-vitro characterization of the above-mentioned biosensor in terms of oxygen, pH and temperature dependence in order to complete its validation. With the aim of enhancing ethanol biosensor performance, different enzyme loadings were investigated in terms of apparent ethanol Michaelis-Menten kinetic parameters, viz. IMAX, KM and linear region slope, as well as ascorbic acid interference shielding. The responses of biosensors were studied over a period of 28 days. The overall findings of the present study confirm the original biosensor configuration to be the best of those investigated for in-vivo applications up to one week after implantation.
- Published
- 2013
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45. Development and characterization of an implantable biosensor for telemetric monitoring of ethanol in the brain of freely moving rats.
- Author
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Rocchitta G, Secchi O, Alvau MD, Migheli R, Calia G, Bazzu G, Farina D, Desole MS, O'Neill RD, and Serra PA
- Subjects
- Animals, Brain drug effects, Electrochemistry, Ethanol administration & dosage, Ethanol pharmacology, Limit of Detection, Male, Ranitidine pharmacology, Rats, Rats, Sprague-Dawley, Time Factors, Biosensing Techniques instrumentation, Brain metabolism, Electrodes, Implanted, Ethanol metabolism, Movement, Telemetry instrumentation
- Abstract
Ethanol is one of the most widespread psychotropic agents in western society. While its psychoactive effects are mainly associated with GABAergic and glutamatergic systems, the positive reinforcing properties of ethanol are related to activation of mesolimbic dopaminergic pathways resulting in a release of dopamine in the nucleus accumbens. Given these neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In this study, we describe the development and characterization of an implantable biosensor for the amperometric detection of brain ethanol in real time. Ten different designs were characterized in vitro in terms of Michaelis-Menten kinetics (V(MAX) and K(M)), sensitivity (linear region slope, limit of detection (LOD), and limit of quantification (LOQ)), and electroactive interference blocking. The same parameters were monitored in selected designs up to 28 days after fabrication in order to quantify their stability. Finally, the best performing biosensor design was selected for implantation in the nucleus accumbens and coupled with a previously developed telemetric device for the real-time monitoring of ethanol in freely moving, untethered rats. Ethanol was then administered systemically to animals, either alone or in combination with ranitidine (an alcohol dehydrogenase inhibitor) while the biosensor signal was continuously recorded. The implanted biosensor, integrated in the low-cost telemetry system, was demonstrated to be a reliable device for the short-time monitoring of exogenous ethanol in brain ECF and represents a new generation of analytical tools for studying ethanol toxicokinetics and the effect of drugs on brain ethanol levels.
- Published
- 2012
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- View/download PDF
46. Brain microdialysis in freely moving animals.
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Bazzu G, Biosa A, Farina D, Spissu Y, Calia G, Dedola S, Rocchitta G, Migheli R, Serra PA, and Desole MS
- Subjects
- Animals, Ascorbic Acid analysis, Catecholamines analysis, Chromatography, High Pressure Liquid methods, Electrochemistry, Indoles analysis, Mice, Rats, Uric Acid analysis, Brain Chemistry, Chemistry Techniques, Analytical, Extracellular Fluid chemistry, Microdialysis methods
- Abstract
Brain microdialysis is an analytical technique used for the dynamic monitoring of brain neurochemistry in awake, freely moving animals. This technique requires the insertion of a small dialysis catheter, called a microdialysis probe, into a specific brain region, and its perfusion with an artificial extracellular fluid. The microdialysate samples, obtained from the probe outlet, can be analysed using high-performance liquid chromatography with electrochemical detection for the quantification of oxidizable molecules recovered from the extracellular space. In this chapter, we describe a protocol for performing a microdialysis setup and experiment in freely moving rats and mice. Furthermore, the high-performance liquid chromatographic determination of ascorbic acid, uric acid, catecholamines, indolamines and derivatives is described in detail.
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- 2012
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47. Dual asymmetric-flow microdialysis for in vivo monitoring of brain neurochemicals.
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Bazzu G, Biosa A, Farina D, Spissu Y, Dedola S, Calia G, Puggioni G, Rocchitta G, Migheli R, Desole MS, and Serra PA
- Subjects
- Animals, Energy Metabolism, Male, Microdialysis instrumentation, Neostriatum metabolism, Perfusion, Rats, Reproducibility of Results, Time Factors, Brain metabolism, Microdialysis methods, Neurotransmitter Agents metabolism
- Abstract
Microdialysis is an extensively used technique for both in vivo and in vitro experiments, applicable to animal and human studies. In neurosciences, the in vivo microdialysis is usually performed to follow changes in the extracellular levels of substances and to monitor neurotransmitters release in the brain of freely moving animals. Catecholamines, such as dopamine and their related compounds, are involved in the neurochemistry and in the physiology of mental diseases and neurological disorders. It is generally supposed that the brain's energy requirement is supplied by glucose oxidation. More recently, lactate was proposed to be the metabolic substrate used by neurons during synaptic activity. In our study, an innovative microdialysis approach for simultaneous monitoring of catecholamines, indolamines, glutamate and energy substrates in the striatum of freely moving rats, using an asymmetric perfusion flow rate on microdialysis probe, is described. As a result of this asymmetric perfusion, two samples are available from the same brain region, having the same analytes composition but different concentrations. The asymmetric flow perfusion could be a useful tool in neurosciences studies related to brain's energy requirement, such as toxin-induced models of Parkinson's disease., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
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48. alpha-Synuclein- and MPTP-generated rodent models of Parkinson's disease and the study of extracellular striatal dopamine dynamics: a microdialysis approach.
- Author
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Bazzu G, Calia G, Puggioni G, Spissu Y, Rocchitta G, Debetto P, Grigoletto J, Zusso M, Migheli R, Serra PA, Desole MS, and Miele E
- Subjects
- Animals, Brain drug effects, Brain metabolism, Dopamine metabolism, Humans, Mice, Mice, Transgenic genetics, Mice, Transgenic metabolism, Parkinsonian Disorders chemically induced, Rats, Rats, Transgenic genetics, Rats, Transgenic metabolism, alpha-Synuclein physiology, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine pharmacology, Disease Models, Animal, Dopamine physiology, Microdialysis, Neurotoxins pharmacology, Parkinson Disease metabolism, Parkinsonian Disorders metabolism, alpha-Synuclein metabolism
- Abstract
The classical animal models of Parkinson's disease (PD) rely on the use of neurotoxins, including 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 6-hydroxydopamine and, more recently, the agricultural chemicals paraquat and rotenone, to deplete dopamine (DA). These neurotoxins elicit motor deficits in different animal species although MPTP fails to induce a significant dopaminergic neurodegeneration in rats. In the attempt to better reproduce the key features of PD, in particular the progressive nature of neurodegeneration, alternative PD models have been developed, based on the genetic and neuropathological links between -synuclein ( -syn) and PD. In vivo microdialysis was used to investigate extracellular striatal DA dynamics in MPTP- and -syn-generated rodent models of PD. Acute and sub-acute MPTP intoxication of mice both induce prolonged release of striatal DA. Such DA release may be considered the first step in MPTP-induced striatal DA depletion and nigral neuron death, mainly through reactive oxygen species generation. Although MPTP induces DA reduction, neurochemical and motor recovery starts immediately after the end of treatment, suggesting that compensatory mechanisms are activated. Thus, the MPTP mouse model of PD may be unsuitable for closely reproducing the features of the human disease and predicting potential long-term therapeutic effects, in terms of both striatal extracellular DA and behavioral outcome. In contrast, the -syn-generated rat model of PD does not suffer from a massive release of striatal DA during induction of the nigral lesion, but rather is characterized by a prolonged reduction in baseline DA and nicotine-induced increases in dialysate DA levels. These results are suggestive of a stable nigrostriatal lesion with a lack of dopaminergic neurochemical recovery. The -syn rat model thus reproduces the initial stage and slow development of PD, with a time-dependent impairment in motor function. This article will describe the above experimental PD models and demonstrate the utility of microdialysis for their characterization.
- Published
- 2010
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49. Contributions by a novel edge effect to the permselectivity of an electrosynthesized polymer for microbiosensor applications.
- Author
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Rothwell SA, Kinsella ME, Zain ZM, Serra PA, Rocchitta G, Lowry JP, and O'Neill RD
- Subjects
- Ascorbic Acid analysis, Biosensing Techniques methods, Calibration, Electrodes, Glutamic Acid analysis, Hydrogen Peroxide metabolism, Permeability, Platinum chemistry, Biosensing Techniques instrumentation, Phenylenediamines chemistry
- Abstract
Pt electrodes of different sizes (2 x 10(-5)-2 x 10(-2) cm(2)) and geometries (disks and cylinders) were coated with the ultrathin non-conducting form of poly(o-phenylenediamine), PPD, using amperometric electrosynthesis. Analysis of the ascorbic acid (AA) and H(2)O(2) apparent permeabilities for these Pt/PPD sensors revealed that the PPD deposited near the electrode insulation (Teflon or glass edge) was not as effective as the bulk surface PPD for blocking AA access to the Pt substrate. This discovery impacts on the design of implantable biosensors where electrodeposited polymers, such as PPD, are commonly used as the permselective barrier to block electroactive interference by reducing agents present in the target medium. The undesirable "edge effect" was particularly marked for small disk electrodes which have a high edge density (ratio of PPD-insulation edge length to electrode area), but was essentially absent for cylinder electrodes with a length of >0.2 mm. Sample biosensors, with a configuration based on these findings (25 microm diameter Pt fiber cylinders) and designed for brain neurotransmitter L-glutamate, behaved well in vitro in terms of Glu sensitivity and AA blocking.
- Published
- 2009
- Full Text
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50. Real-time monitoring of brain tissue oxygen using a miniaturized biotelemetric device implanted in freely moving rats.
- Author
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Bazzu G, Puggioni GG, Dedola S, Calia G, Rocchitta G, Migheli R, Desole MS, Lowry JP, O'Neill RD, and Serra PA
- Subjects
- Acetazolamide pharmacology, Animals, Biosensing Techniques instrumentation, Corpus Striatum metabolism, Male, Miniaturization, Rats, Rats, Sprague-Dawley, Telemetry, Biosensing Techniques methods, Brain metabolism, Oxygen analysis
- Abstract
A miniaturized biotelemetric device for the amperometric detection of brain tissue oxygen is presented. The new system, derived from a previous design, has been coupled with a carbon microsensor for the real-time detection of dissolved O(2) in the striatum of freely moving rats. The implantable device consists of a single-supply sensor driver, a current-to-voltage converter, a microcontroller, and a miniaturized data transmitter. The oxygen current is converted to a digital value by means of an analog-to-digital converter integrated in a peripheral interface controller (PIC). The digital data is sent to a personal computer using a six-byte packet protocol by means of a miniaturized 434 MHz amplitude modulation (AM) transmitter. The receiver unit is connected to a personal computer (PC) via a universal serial bus. Custom developed software allows the PC to store and plot received data. The electronics were calibrated and tested in vitro under different experimental conditions and exhibited high stability, low power consumption, and good linear response in the nanoampere current range. The in vivo results confirmed previously published observations on oxygen dynamics in the striatum of freely moving rats. The system serves as a rapid and reliable model for studying the effects of different drugs on brain oxygen and brain blood flow and it is suited to work with direct-reduction sensors or O(2)-consuming biosensors.
- Published
- 2009
- Full Text
- View/download PDF
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