3,136 research outputs found
Exploiting Structural Analysis, in Silico Screening and functional variants characterization to identify novel inhibitors of cytidine deaminase
No full textThis thesis work, combining a virtual screening study for cytidine deaminase ligands with a study on the effect that genetic polymorphisms have on the enzyme functionality provide a useful base to: a) understand the mechanism of nucleoside recognition by CDA and identify novel effective inhibitors; and b) study the different properties of said inhibitors toward three distinct naturally occurring CDA variants (K27, Q27 and T70). Ultimately, this may assist the future design of novel CDA inhibitors or antitumor drugs not susceptible to deamination, with the aim to get more effective personalized drug therapies
Studies on the antimicrobial activity of Silver Nanoparticles as additive for several kind of materials
No full textStudies on the antimicrobial activity of Silver Nanoparticles as additive for several kind of materials
Rossana, Galassi;a Anna Teresa, Ramadori;a § Alfredo, Burini;a Daniela, Micozzi;b Stefania, Pucciarelli.b
a Scuola di Scienze e Tecnologie, Divisione di Chimica, Università di Camerino, Via Sant’Agostino, 1, Camerino, I-62032, Italy.
b Scuola di Bioscienze e Medicina Veterinaria, Polo di Bioscienze, Università di Camerino, Via Gentile III da Varano, Camerino, I-62032, Italy.
§ fellow granted by project T.R.A.S.P.A.R.E.N.T.E. DGR 1464 del 7/11/2011, Regione Marche.
Silver nanoparticles (AgNPs) have attracted extensive research interest due to their attractive optical, electronic properties and excellent antimicrobial activities. AgNPs exhibit strong cytotoxicity towards a broad range of microorganisms and are widely used as an antibacterial agents.1 The advantage of AgNPs compared to bulk metal or salts is the slow and regulated release of silver from nanoparticles, thereby causing long lasting protection against bacteria. The antimicrobial activity of AgNPs is comparatively better than most prominent antibiotics used worldwide.2 Numerous methods have been developed for the preparation of AgNPs. The most common method is the chemical reduction of silver salt by a reducing agent in the presence of a stabilizing agent. In this work AgNPs have been prepared by reducing silver cations with NaBH4 and using as stabilizer sodium citrate, PVP (polivinylpirrolidone) or polysaccharides. AgNPs so obtained were characterized as average 10 nm particles by DLS and UV-vis spectroscopy. This work has the aim to verify the biocide action of silver nanoparticles mainly in plasters but also in other substrates occurring in a civil environment to reduce exposure to risk of infection by people with weak immune system. The study was focused to develop a method of study for each kind of material both in the AgNPs dispersion’s method and on the antimicrobial activity of the resulting substrate treated with AgNps. The antimicrobial activity has been led on Escherichia coli cells cultured in Luria Broth.3 The minimum concentration needed to have effects has been determined in each case. Moreover a comparative study of the inhibitory effect of AgNPs and silver salts such as AgNO3 and AgCF3SO3 on the regards of DHFR (DeHydroFolateReductase) from E. Coli has been performed.
1) Xihui Zhao; Yanzhi Xia; Qun Li; Xiaomei Ma Fengyu, Quan Cunzhen Geng, Zhenyu Han. Colloids and Surfaces A: Physicochem. Eng. Aspects 444, 2014, 180-188. doi.org/10.1016/j.colsurfa.2013.12.008
2) R. Roy, M. R. Hoover, A. S. Bhalla, T. Slawecki, S. Dey, W. Cao, J. Li, S. Bhaskar. Material Research Innovation, Volume 11, Issue 1 ,2007, 3-18. DOI 10.1179/143307507X196167.
3) Ivan Sondi and Branka Salopek-Sondi. Journal of Colloid and Interface Science 2004, 275, 177-182. doi:10.1016/j.jcis.2004.02.01
Dihydrofolate reductase: a new molecular target for gold(I) drugs?
No full textDehydrofolate reductasi : a new molecular target for gold(I) drugs?
R. Galassi,a A. Burini,a D. Micozzi,a A. Dolmella,b S. Pucciarellic
a School of Science and Technology, Chemistry Division, University of Camerino, 62032 Camerino (Italy);
b Department of Pharmaceutical Sciences, University of Padova, 35131 Padova (Italy);
c School of Biosciences and Biotechnology, University of Camerino, 62032 Camerino (Italy).
[email protected]
DHFR is an important enzyme mainly involved in the synthesis of pyrimidine and thymine basilar for the DNA replication and hence the cell proliferation. To perform its functions the DHFR enzyme needs the presence of a substrate and a cofactor such as NADPH and H2F.[1] Despite its fundamental importance in the cell’s metabolism this enzyme has never been tested as molecular target for gold(I) compounds which anti-proliferative action was ascertained. In fact, it is generally accepted that gold compounds act as multi-target drug and the proposed mechanisms mainly involve enzymes. Moreover, their action is function of their overall structure and of the nature of the ligands around the central metal atom.
Some pyrazolyl and imidazolyl gold(I) phosphane complexes synthesized by us have shown anticancer properties and they successfully inhibit some seleno-dependent enzymes such as thioredoxina reductase and glutathione peroxidase.[2] To investigate in depth their action on the regards of enzyme, inhibitory studies on DHFR have been carried out. Moreover, appropriate modifications in their structure have been performed in order to get information about the structure/properties relationship.
DTNB assays, stability studies in solution and affinity constant determinations have been performed too. Some conclusions about the possible mechanism of action may be taken accordingly.
Acknowledgements
Authors are grateful to CIRCSMB for Daniela Micozzi fellowship.
References
[1] M. Brandsch, I. Knütter, E. Bosse-Doenecke, J. Pharm. Pharmacol. 2008, 60, 543.
[2] R. Galassi, A. Burini, S. Ricci, M. Pellei, M. P. Rigobello, A. Citta, A. Dolmella, V. Gandin, C Marzano. Dalton Trans., 2012, 41, 530
A proteomic study on the effect of polyphenolic extract from extra-virgin olive oil on a yeast model of aging
No full textSaccharomyces cerevisiae can serve as a model to study the molecular mechanism underlying human neurodegenerative diseases and aging [1, 2]. In this study, a S. cerevisiae strain that express a glutamine repeat domain (103Q) of Huntingtin, the causing agent of protein misfolding leading to Huntington disease (HD), has been used for monitoring the effect of a polyphenol extracts from extra-virgin olive oil (EVOO) on neurodegeneration. In fact, it is well known that olive polyphenols such as tyrosol, hydroxytyrosol, and their complex derivatives exert a protective effect against oxidative damage, one of the main factors associated with age-related pathologies.
At this purpose, the chronological aging of yeast strain 103Q, has been monitored in comparison with the wild type strain (GFP) by assessing the cell viability and the proteomic pattern. Polyphenols, after their extraction from EVOOs, have been introduced in the culture broth of both 103Q and GFP strains. Cells from both strains were harvested 6 (young), 15 (adult) and 26 (old cells) days after inoculation and the protein expression was evaluated in both strains by two-dimensional electrophoresis (2DE), consisting of a first dimension on an immobilized pH gradient 3-10 gel (Immobiline DryStrip gel, 18cm, GE Healthcare) and a second dimension through a 13% SDS-PAGE [3]. After electrophoresis, the silver stained gel was subjected to image analysis (by the PDquest software) and to mass spectrometry for protein identification.
As a result, we found that polyphenols induce the expression of several proteins both in the neurodegeneration model (103Q) and in the controls (GFP). Until now, two spots were identified, one as "hypothetical protein AWRI1631_45230" [S. cerevisiae AWRI1631], and the other one as "YOR012W-like protein" [S. cerevisiae AWRI796], whose function is not known. Interestingly, in the system where huntingtin is expressed (103Q), we found a protein region, with a broad molecular weight (MW) around 22.2 kDa, and an isoelectric point (pI) of 3.8 which decreases after the administration of polyphenols. Ocampo and co-workers [2], during immunoblotting experiments performed to follow the induced 103Q expression and oligomerization, found the presence of degradation products at low molecular weight (about 35 kDa). With this in mind, we could speculate that the protein region showing the broad molecular weigh observed in our experiments may be a degradation product of the 103Q protein. Obviously, further studies should be carried out in order to validate this hypothesis.
In conclusion, the results of the present study are very encouraging, and we can conclude that the yeast model of neurodegeneration proved to be a very promising system for the evaluation of antioxidant/nutraceutical substances efficacy towards neurodegenerative diseases.
References:
[1] Mortimer R.K., Johnston J.R. Life span of individual yeast cells. Nature. 1959; 183:1751-1752.
[2] Ocampo A., Liu J. and Barrientos A. NAD salvage pathway proteins suppress proteotoxicity in yeast models of neurodegeneration by promoting the clearance of misfolded/oligomerized proteins. Hum Mol Genet. 2013;22:1699-1708.
[3] S. Vincenzetti, A. Amici, S. Pucciarelli, A. Vita, D. Micozzi, F. M. Carpi, V. Polzonetti, P.
Natalini, P. Polidori. A Proteomic Study on Donkey Milk. Biochem Anal Biochem. 2012; 1, 109
Enzymology of Pyrimidine Metabolism and Neurodegeneration
No full textIt is well known that disorders of pyrimidine pathways may lead to neurological, hematological, immunological diseases, renal impairments, and association with malignancies. Nucleotides homeostasis depends on the three portion of pyrimidine metabolism: de novo synthesis, catabolism and recycling of these metabolites. Cytidine and uridine, in addition to be used as substrates for pyrimidine nucleotide salvaging, also act as the precursors of cytidine triphosphate used in the biosynthetic pathway of both brain phosphatidylcholine and phosphatidylethanolamine via the Kennedy cycle. The synthesis in brain of phosphatidylcholine and other membrane phosphatides can utilize, in addition to glucose, three compounds present in the blood stream: choline, uridine, and a polyunsaturated fatty acis like docosahexaenoic acid. Some authors, using rat models, found that oral administration of two phospholipid precursors such as uridine and omega-3 fatty acids, along with choline from the diet, can increase the amount of synaptic membrane generated by surviving striatal neurons in rat models with induced Parkinson's disease. Other authors found that in hypertensive rat fed with uridine and choline, cognitive deficit resulted improved. Uridine has also been recently considered as a neuroactive molecule, because of its involvement in important neurological functions by improving memory, sleep disorders, anti-epileptic effects, as well as neuronal plasticity. Cytidine and uridine are uptaken by the brain via specific receptors and successively salvaged to the corresponding nucleotides. The present review is devoted to the enzymology of pyrimidine pathways whose importance has attracted the attention of several researchers investigating on the mechanisms underlying the physiopathology of brain
Antioxidant Properties of Donkey Milk
No full textIn the present work the well-known beneficial donkey’s milk (DM)
characteristics to human health have been investigated, focusing
the attention on anti-oxidant properties. For this purpose, vitamin
C, lactoferrin, lactoperoxidase activity and total antioxidant power
(PAO) were determined on milk whereas the reactive oxygen
metabolites (ROM) and PAO concentrations were evaluated on
blood. The trial was carried out on 10 pluriparous jennets. Sterile
blood and milk samples were collected during three different periods
of lactation. Microbiological tests, SCC (by a fluoro-optoelettronic
method), PAO and ROM determinations were performed
by commercial kits. Quantitative determination of lactoferrin from
DM was determined by an HPLC method, lactoperoxidase activity
was evaluated by a continuous spectrophotometric method, vitamin
C content determination was performed using a commercial
kit. The obtained data were subjected to the analysis of variance
(ANOVA, SPSS). Mean values of the investigated param -
eters±standard errors were calculated. No significant differences
were observed for ROM, SCC and neither blood or milk PAO
(respectively, 4.45±0.1 mmol/L; 50.9±19.9¥103/mL; 166.2±4.1 and
55.5±3.2 μmol HClO/mL). The fresh DM contains 57 mg/L of vitamin
C, similar to that of human milk but higher compared with
that of cow’s milk. The lactoferrin concentration in DM is
0.080±0.0035 g/L, very close to that obtained for mare, bovine but
lower if compared with human milk. Mature DM contains low but
detectable LPO activity (0.11±0.027 mg/L) similarly to value
obtained from human milk. Concluding, for the first time were
determined the PAO and ROM reference range in DM, furthermore
the high content of vitamin C in DM confirms the important
nutritional characteristics of this product
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
The effects of low voltage electrical stimulation on donkey meat
No full textThe effects of early post-mortem low voltage electrical stimulation (28 V, 60 Hz) on biochemical changes and on final tenderness in Longissimus Thoracis et Lumborum (LTL) muscle from donkey carcasses was studied. ES significantly accelerated the glycolytic process only during the first hours post-mortem, with a faster pH fall at 1, 3 and 6 h post-mortem, and a reduction in ATP content at 3 and 6 h post-mortem. The activities of μ-calpain and calpastatin were reduced (P < 0.05) by the treatment in the first 6 h post-mortem. Tenderness was improved (P < 0.05) at 4 and 7 days post-mortem by the application of ES. Muscle colour (L*) was lighter (P < 0.05) in stimulated carcasses
Imparare le lingue per abbracciare il mondo
No full textL’autrice che si colloca, come Daniela Zorzi, tra i fautori di una linguistica “impegnata”, propone in ricordo della studiosa amica, una riflessione sul ruolo cruciale del multilinguismo e delle lingue- culture, per il successo professionale e il benessere sociale, nella società contemporanea. Il multilinguismo appare come un’urgenza educativa che interpella studiosi e formatori a tutti i livelli al fine di promuovere nei giovani un apprendimento consapevole efficace ed autonomo.Multilingualism constitutes an urgent objective for education, which needs to involve teachers and researchers at all levels if we are to promote effective and autonomous learning in the young. Like Daniela Zorzi, the author considers herself a socially engaged linguist, and in memory of her friend’s work, offers a reflection on the key roles of languages and cultures and of multilingualism for professional success and social welfare today
Reclamações ambientais em Aveiro, Portugal: atores, preocupações, padrão territorial e resoluções
No full textThis paper presents an environmental diagnosis based on public complaints on environmental
issues submitted to the Environmental Department of the Aveiro City Council, Portugal, between
2000 and 2005. It discusses the potential influences of these in local environmental planning
and governance. The paper has been organised into five sections. The first of these introduces
the study. The second section focuses on the conceptual approaches relating to environmental
grassroots movements, the main actors involved in these movements and the role played by
local government. It also contains a brief review of the most recent urban environmental
quality challenges in the European context together with a description of the main features of
the associated political and legal framework in Portugal. The third section describes the case
study and the methodology used. The results of the empirical study are detailed in the fourth
section. The final section critically analyses these results with emphases on the temporal
evolution of the submission of complaints, the actors involved, the local environmental problems
and their associated spatial pattern as well as the responses given by the City Council. This
information may then be used to provide a useful indicator for the perception of environmental
quality as well as a credible instrument for the visualisation and evaluation of local performance
in terms of environmental planning and management.AlBan Programme - n. E05M053040B
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