382 research outputs found
Scenarios and possible futures for hospitality and tourism
Purpose - This paper seeks to discuss the process and results of a scenario exercise applied to the Portuguese tourism and hospitality industries with a 2020 horizon. Design/methodology/approach - Through an intuitive-logical process adapted to the specific purposes of the research, four alternative scenarios of the evolution of the industry were developed. The exercise involved three workshops, with the participation of a group of experts, academics, representatives from industry and local government. Findings - Based on the nature and dynamics of the key forces and trends, the four scenarios identified are: southern experience; global emotions; "sin surprise"; and non-charming Portugal. In all scenarios there is increased global competition amongst tourist destinations. A desire for authenticity opens the opportunity for Portugal as a tourist destination but it also poses challenges for managers and policy makers. These scenarios are of practical use for managers, policy makers and other practitioners as they provide a framework for the development and assessment of robust strategies and policies, i.e. strategies that will survive several kinds of external development. Originality/value - The paper contributes to the knowledge of scenario methods in practice and to help policy planners and managers recognize, consider and reflect on uncertainties they are likely to face. The work is also valuable for the international foresight community by discussing the method and addressing some drawbacks of the scenario exercise and recommendations for practice. © Emerald Group Publishing Limited.Instituto de Investigação from University of Aveiro for the Project Enterprise of the Futur
Glutathione And S-nitrosoglutathione In Alginate/chitosan Nanoparticles: Cytotoxicity
Nitric oxide (NO) is involved in several physiological processes, such as the control of vascular tone, the immune response and the wound healing process. Thus, there is a great interest in the development of NO-releasing drugs and in matrices which are able to stabilize and release NO locally in different tissues. Thiols, such as glutathione (GSH), are ready nitrosated to form the NO donors S-nitrosothiols (RSNOs). In this work, GSH, a precursor of the NO donor S-nitrosoglutathione (GSNO), was encapsulated into a mucoadhesive combination of alginate/chitosan nanoparticles. The encapsulated GSH was nitrosated in the alginate/chitosan nanoparticles by adding sodium nitrite, leading to the formation of encapsulated GSNO. The cytotoxicity characterization of the nanoparticles containing either GSH or GSNO showed that these materials were completely non cytotoxic to cellular viability. These results show that this novel nanostructure biomaterial has a great potential to be use in biomedical applications where NO has a therapeutical effect.3041Seabra, A.B., Fitzpatrick, A., Paul, J., De Oliveira, M.G., Weller, R., (2004) Br. J. Dermatol., 151, p. 977Seabra, A.B., Pankotai, E., Fehér, M., Somlai, A., Kiss, L., Bíró, L., Szabó, C., Lacza, Z., (2007) Br. J. Dermatol., 156, p. 814Moore, C., Tymvios, C., Emerson, M., (2010) Thromb. Haemost., 104, p. 342Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2007) J. Eur. Acad. Dermatol. Venereol., 21, p. 629Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2008) J. Surg Res., 149, p. 84Nahrevanian, H., Amini, M., (2008) Iranian J. Basic Med. Sci., 11, p. 197Seabra, A.B., Durán, N., (2010) J. Mater. Chem., 20, p. 1624Kapadia, M.R., Chow, L.W., Tsihlis, N.D., Ahanchi, S.S., Eng, J.W., Murar, J., Martinez, J., Kibbe, M.R., (2008) J. Vasc. Surg., 47, p. 173De Oliveira, M.G., Shishido, S.M., Seabra, A.B., Morgon, M.H., (2002) J. Phys. Chem., 106, p. 8963Hogg, N., Singh, R.J., Kalyanaraman, B., (1996) FEBS Lett., 382, p. 223Seabra, A.B., Da Silva, R., De Souza, G.F.P., De Oliveira, M.G., (2008) Artif. Organs, 32, p. 262Seabra, A.B., Martins, D., Simes, M.M.S.G., Da Silva, R., Brocchi, M., De Oliveira, M.G., (2010) Artif. Organs, 34, p. 204Seabra, A.B., De Souza, G.F.P., Da Rocha, L.L., Eberlin, M.N., De Oliveira, M.G., (2004) Nitric Oxide, 11, p. 263Seabra, A.B., Da Silva, R., De Oliveira, M.G., (2005) Biomacromolecules, 6, p. 2512Frost, M.C., Reynolds, M., Meyerhoff, M.E., (2005) Biomaterials, 26, p. 1685Fortenberry, J.D., Owens, M.L., Brown, L.A.S., (1999) Am. J. Physiol. Lung Cell Mol. Physiol., 276, p. 435Douglas, K.L., Piccirillo, C.A., Tabrizian, M., (2006) J. Control. Release, 115, p. 354Correa, D.H.A., Melo, P.S., De Carvalho, C.A.A., De Azevedo, M.B.M., Durán, N., Haun, M., (2005) Eur. J. Pharmacol., 510, p. 17De Conti, R., Oliveira, D.A., Fernandes, A.M.A.P., Melo, P.S., Rodriguez, J.A., Haun, M., Castro, S.L., Durán, N., (1998) In Vitro Mol. Toxicol, 11, p. 153Borefreund, E., Puerner, J.A., (1984) J. Tissue Cult. Methods, 9, p. 7Denizot, F., Lang, R., (1986) J. Immunol. Methods, 89, p. 27
Antitumoral Activity Of L-ascorbic Acid-poly-d, L-(lactide-co-glycolide) Nanoparticles Containing Violacein
It has been demonstrated that tumoral cells have a higher uptake of ascorbic acid compared to normal cells. This differential characteristic can be used as a way to improve the specificity of antitumoral compounds if combined with polymeric drug delivery systems. The aim of this study was to prepare, characterize and evaluate the antitumoral activity of poly-D,L-(lactide-co-glycolide) 50:50 loading the antitumoral compound violacein and capped with L-ascorbic acid. Nanoparticles were prepared using the nanoprecipitation method and morphologically characterized by scanning electron microscopy (SEM). The average diameter and Zeta potential were determined by photon correlation spectroscopy method (PCS), and assays were carried out to determine the content of ascorbic acid and in vitro drug release kinetics. The antitumoral activity of this system was also evaluated against HL-60 cells by tetrazolium reduction assay. Nanoparticles with size distribution between 300-400 nm and strong negative outer surface (-40 mV) were obtained by this method. Analysis of ascorbic acid content showed that this compound was mainly localized on the external surface of nanoparticles. Violacein loading efficiency was determined as 32% ± 1% and this drug was gradually released from nanoparticles at different rates depending on the composition of the release media. In addition, this system was observed to be 2 × more efficient as an antitumoral compared with free violacein. © 2010 Martins et al.517785Sofou, S., Surface-active liposomes for targeted cancer therapy (2007) Nanomedicine, 2, pp. 711-724Savona, M., Talpaz, M., Getting to the stem chronic myeloid leukaemia (2008) Nature Rev Cancer, 8, pp. 341-350Narayana, A., Kelly, P., Golfinos, J., Antiangiogenic therapy using bevacizumab in recurrent high-grade glioma: Impact on local control and patient survival (2009) J Neurosurg, 110, pp. 173-180Paternot, S., Roger, P.P., Combined inhibition of MEK and mammalian target of rapamycin abolishes phosphorylation of cyclin-dependent kinase 4 in glioblastoma cell lines and prevents their proliferation (2009) Cancer Res, 69, pp. 4577-4581Egilmez, N.K., Kilinc, M.O., Gu, T., Controlled-release particulate cytokine adjuvants for cancer therapy (2007) Endocr Metab Immune Disord Drug Targets, 7, pp. 266-270Nemunaitis, J.J., Gene immunotherapy for non-small cell lung cancer (2009) Methods Mol Biol, 542, pp. 499-514Douziech-Eyrolles, L., Marchais, H., Hervé, K., Nanovectors for anticancer agents based on superparamagnetic iron oxide nanoparticles (2007) Int J Nanomedicine, 2, pp. 541-550Ciampi, R., Vivaldi, A., Romei, C., Expression analysis of facilitative glucose transporters (GLUTs) in human thyroid carcinoma cell lines and primary tumors (2008) Mol Cell Endocrinol, 291, pp. 57-62Agus, D.B., Vera, J.C., Golde, D.W., Stromal cell oxidation: A mechanism by which tumors obtain vitamin C (1999) Cancer Res, 18, pp. 4555-4558Torchilin, V.P., Micellar nanocarriers: Pharmaceutical perspectives (2007) Pharm Res, 24, pp. 1-16Marcato, P.D., Durán, N., New aspects of nanopharmaceutical delivery systems (2008) J Nanosci Nanotechnol, 8, pp. 2216-2229Har-El, Y.E., Kato, Y., Intracellular delivery of nanocarriers for cancer therapy (2007) Curr Nanosci, 3, pp. 329-338Arruebo, M., Fernández-Pacheco, R., Ibarra, M.R., Santamaría, J., Magnetic nanoparticles for drug delivery (2007) Nanotoday, 2, pp. 22-32Bharali, D.J., Khalil, M., Gurbuz, M., Simone, T.M., Mousa, S.A., Nanoparticles and cancer therapy: A concise review with emphasis on dendrimers (2009) Int J Nanomedicine, 4, pp. 1-7Tekade, R.K., Kumar, P.V., Jain, N.K., Dendrimers in oncology: An expanding horizon (2009) Chem Rev, 109, pp. 49-87Nair, L.S., Laurencin, C.T., Biodegradable polymers as biomaterials (2006) Progr Polym Sci, 32, pp. 762-798Jain, K.K., Recent advances in nanoocology (2008) Technol Cancer Res Treat, 7, pp. 1-13Mundargi, R.C., Babu, V.R., Rangaswamy, V., Patel, P., Aminabhavi, T.M., Nano/micro technologies for delivering macromolecular therapeutics using poly(D,L-lactide-co-glycolide) and its derivatives (2008) J Control Release, 125, pp. 193-209Durán, N., Menck, C.F., Chromobacterium violaceum: A review of pharmacological and industrial perspectives (2001) Crit Rev Microbiol, 27, pp. 201-222Durán, N., Justo, G.Z., Ferreira, C.V., Melo, P.S., Cordi, L., Martins, D., Violacein: Properties and biological activities (2007) Biotechnol Appl Biochem, 48, pp. 127-133Ferreira, C.V., Bos, C.L., Versteeg, H.H., Justo, G.Z., Durán, N., Peppelenbosch, M.P., Molecular mechanism of violacein-mediated human leukemia cell death (2004) Blood, 104, pp. 1459-1464de Carvalho, D.D., Costa, F.T.M., Durán, N., Haun, M., Cytotoxic activity of violacein in human colon cancer cells (2006) Toxicol In Vitro, 20, pp. 1514-1521Bromberg, N., Justo, G.Z., Haun, M., Durán, N., Ferreira, C.V., Violacein cytotoxicity on human blood lymphocytes and effect on phosphatases (2005) J Enzyme Inhib Med Chem, 20, pp. 449-454Rettori, D., Durán, N., Production, extraction and purification of violacein: An antibiotic pigment produced by Chromobacterium violaceum (1998) World J Microb Biotechnol, 14, pp. 685-688Italia, J.L., Yahya, M.M., Singh, D., Ravi Kumar, M.N., Biodegradable nanoparticles improve oral bioavailability of amphotericin B and show reduced nephrotoxicity compared to intravenous Fungizone (2009) Pharm Res, 26, pp. 1324-1331Melo, P.S., de Azevedo, M.M., Frugillo, L., Anazetti, M.C., Marcato, P.D., Durán, N., Nanocytotoxicity: Violacein and violacein-loaded poly(D,L-lactide-co-glycolide) nanoparticles acting on human leukemic cells (2009) J Biomed Nanotechnol, 5, pp. 192-201Martins, D., Costa, F.T.M., Brocchi, M., Evaluation of the antibacterial activity of poly-(D,L-lactide-co-glycolide) nanoparticles containing violacein (2009) J Nanoparticle Res, , Submission number: NANO2280Suntornsuk, L., Gritsanapun, W., Nilkamhank, S., Paochom, A., Quantitation of vitamin C content in herbal juice using direct titration (2002) J Pharm Biomed Anal, 28, pp. 849-855Frungillo, L., Martins, D., Teixeira, S., Anazetti, M.C., Melo Pda, S., Durán, N., Targeted antitumoral dehydrocrotonin nanoparticls with L-ascorbic acid 6-stearate (2009) J Pharm Sci, 98, pp. 4796-4807Arranz, N., Haza, A.I., García, A., Delgado, M.E., Rafter, J., Morales, P., Inhibition by vitamin C of apoptosis induced by N-nitrosamines in HepG2 and HL-60 cells (2008) J Appl Toxicol, 28, pp. 788-796Lopes, S.C., Blanco, Y.C., Justo, G.Z., Violacein extracted from Chromobacterium violaceum inhibits Plasmodium growth in vitro and in vivo (2009) Antimicrob Agents Chemother, 53, pp. 2149-2152Cabane, B., Blanchon, S., Neves, C., Recombination of nanometric vesicles during freeze-drying (2006) Langmuir, 22, pp. 1982-1990Lee, J., Cheng, Y., Critical freezing rate in freeze drying nanocrystal dispersions (2006) J Control Release, 111, pp. 185-192Holzer, M., Vogel, V., Mäntele, W., Schwartz, D., Haase, W., Langer, K., Physico-chemical characterisation of PLGA nanoparticles after freeze-drying and storage (2009) Eur J Pharm Biopharm, 72, pp. 428-437Chen, Q., Espey, M.G., Sun, A.Y., Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and hydrogen peroxide in extracellular fluid in vivo (2007) Proc Natl Acad Sci USA, 104, pp. 8749-8754Yu, B., Zhao, X., Lee, L.J., Lee, R.J., Targeted delivery systems for oligo-nucleotide therapeutics (2009) AAPS J, 11, pp. 95-203Chen, H., Ahn, R., van den Bossche, J., Thompson, D.H., O'Halloran, T.V., Folate-mediated intracellular drug delivery increases the anticancer efficacy of nanoparticulate formulation of arsenic trioxide (2009) Mol Cancer Ther, 8, pp. 1955-1963Macheda, M.L., Rogers, S., Best, J.D., Molecular and cellular regulation of glucose transporter (GLUT) proteins in cancer (2005) J Cell Physiol, 202, pp. 654-662Airley, R.E., Mobasheri, A., Hypoxic regulation of glucose transport, anaerobic metabolism and angiogenesis in cancer: Novel pathways and targets for anticancer therapeutics (2007) Chemotherapy, 53, pp. 233-256Fonteyne, P., Casneuf, V., Pauwels, P., Expression of hexokinases and glucose transporters in treated and untreated oesophageal adenocarcinoma (2009) Histol Histopathol, 24, pp. 971-977Daskalow, K., Pfander, D., Weichert, W., Distinct temporospatial expression patterns of glycolysis-related proteins in human hepatocellular carcinoma (2009) Histochem Cell Biol, 132, pp. 21-3
Nanoparticles In Treatment Of Thermal Injured Rats: Is It Safe?
The aim of this study was to assess whether thermal trauma induced oxidative stress altered the balance between oxidant and antioxidant systems in the blood of burn wound rats in the absence and presence of silver nanoparticles and S-nitrosoglutathione, GSNO. Free silver nanoparticles, free GSNO and silver nanoparticles + GSNO had no cytotoxic effects. Under anesthesia, the shaved dorsum of the rats was exposed to 90°C (burn group) water bath. Studied compounds were administered topically immediately and at 28 days after the burn injury, four times a day. Silver nanoparticles and silver nanoparticles + GSNO were no toxic in vitro and in vivo. There were no significant differences in the levels of urea, creatinine, aminotransferases and hematological parameters, in control-burn groups (free silver nanoparticles) and treated-burn groups (free GSNO or silver nanoparticles + GSNO). There were no differences in lipid peroxidation and in the levels of protein carbonyls and glutathione, used as oxidative stress markers. A little inflammatory cell response, papillary dermis vascularization, fibroblasts differentiated into contractile myofibroblasts and the presence of a large amount of extracellular matrix were evidenced in treated groups following skin injury. These results indicate that silver nanoparticles and GSNO may provide an effective action on wound healing.3041Tian, J., Wong, K.K.Y., Ho, C.M., Lok, C.N., Yu, W.Y., Che, C.M., Chiu, J.F., Tam, P.K.H., (2007) J. Chem. Med. Chem., 2, p. 129Teli, M.K., Mutalik, S., Rajanikant, G.K., (2010) Cur. Pharm. Design., 16, p. 1882Schaller, M., Laude, J., Bodewaldt, H., Hamm, G., Korting, H.C., (2004) Skin Pharmacol. Physiol., 17, p. 31Seabra, A.B., Da Silva, R., De Souza, G.F.P., De Oliveira, M.G., (2008) Artif. Organs, 32, p. 262Seabra, A.B., Pankotai, E., Fehér, M., Somlai, A., Kiss, L., Bíró, L., Szabó, C., Lacza, Z., (2007) Br. J. Dermatol., 156, p. 814Seabra, A.B., Martins, D., Simes, M.M.S.G., Da Silva, R., Brocchi, M., De Oliveira, M.G., (2010) Artif. Organs, 34, p. 204Durán, N., Marcato, P.D., Alves, O.L., De Souza, G.I.H., Esposito, E., (2005) J. Nanobiotechnol., 3, p. 1Durán, N., Marcato, P.D., De Souza, G.I.H., Alves, O.L., Esposito, E., (2007) J. Biomed. Nanotechnol., 3, p. 203Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2007) J. Eur. Acad. Dermatol. Venereol., 21, p. 629Amadeu, T.P., Seabra, A.B., De Oliveira, M.G., Costa, A.M.A., (2008) J. Surg Res., 149, p. 84Correa, D.H.A., Melo, P.S., De Carvalho, C.A.A., De Azevedo, M.B.M., Durán, N., Haun, M., (2005) Eur. J. Pharmacol., 510, p. 17De Conti, R., Oliveira, D.A., Fernandes, A.M.A.P., Melo, P.S., Rodriguez, J.A., Haun, M., Castro, S.L., Durán, N., (1998) Vitro Mol. Toxicol, 11, p. 153Borefreund, E., Puerner, J.A., (1984) J. Tissue Cult. Methods, 9, p. 7Denizot, F., Lang, R., (1986) J. Immunol. Methods, 89, p. 271Michailidis, Y., Jamurta, A.Z., Nikolaidis, M.G., Fatouros, I.G., Koutedakis, Y., Papassotiriou, I., (2007) Med. Sci. Sport Exerc., 39, p. 1107Davis, T.A., Amare, M., Naik, S., Kovalchuk, A.L., Tadaki, D., (2007) Wound Repair Regen., 15, p. 57
Free 2-propen-1-amine Derivative And Inclusion Complexes With β-cyclodextrin: Scanning Electron Microscopy, Dissolution, Cytotoxicity And Antimycobacterial Activity
Inclusion complexes and physical mixtures of isomeric mixture of E/Z (50:50) of 3-(4′-bromo-[1,1′-biphenyl]-4-yl)-3-(4-bromophenyl)-N,N- dimethyl-2-propen-1-amine (BBAP) and β-cyclodextrin (β-CD) in the molar proportion of 1:1 and 1:2 were analyzed by scanning electron microscopy. The dissolution behavior of BBAP and of the inclusion complexes were also evaluated for six hours. By scanning electron microscopy (SEM), it was possible to observe an inclusion complex formed between BBAP and β-CD by co-evaporation, either in the molar proportion of 1:1 or 1:2. In the physical mixtures, no complex was observed as previously detected by physicochemical analysis. The dissolution studies showed that the inclusion complexes BBAP/β-CD 1:1 and 1:2 released respectively 49.07 ± 1.48 and 40.26 ± 3.90% of BBAP during six hours. Free BBAP was less soluble than the inclusion complex and reached 9.00 ± 0.75% of dissolution. Biological assays, such as cytotoxicity to J774 macrophages and to a permanent lung fibroblast cell line (V79), indicated that the BBAP does not exhibit any additional toxic effect with the β-CD complexes. However, the complexes were less cytotoxic to V79 cells than the free form. The BBAP/β-CD inclusion complexes were more effective (MIC) than the free compound on several mycobacteria strains. Similar behavior was observed for BBAP/β-CD complexes and rifampicin, a front-line antitubercular drug, on M. tuberculosis H37Rv growing inside J774 macrophages.155682689Bibby, D.C., Davies, N.M., Tucker, I.G., (2000) Int. J. Pharm., 197, p. 1De Souza, A.O., Sato, D.N., Aily, D.C.G., Durán, N., (1998) J. Antimicrob. Chemother., 42, p. 407Pereira, D.G., De Castro, S.L., Durán, N., (1998) Acta Tropica, 69, p. 205De Souza, A.O., Santos Júnior, R.R., Ferreira-Júlio, J.F., Rodrigues, J.A., Melo, P.S., Haun, M., Sato, D.N., Durán, N., (2001) Eur. J. Med. Chem., 36, p. 843De Souza, A.O., Hemerly, F.P., Busollo, A.C., Melo, P.S., Machado, G.M.C., Miranda, C.C., Santa-Rita, R.M., Durán, N., (2002) J. Antimicrob. Chemother., 50, p. 629De Conti, R., Gimenez, S.M.N., Haun, M., Pilli, R.A., De Castro, S.L., Durán, N., (1996) Eur. J. Med. Chem., 31, p. 915De Souza, A.O., Santos Jr., R.R., Sato, D.N., Lima, H.O.S., Andrade-Santana, M.H., Alderete, J.B., Faljoni-Alario, A., Durán, N., (2000) Abstracts of the 29 a Reunião Anual Da Sociedade Brasileira de Bioquímica, , Caxambu, BrazilHiguchi, T., Connors, K.A., (1965) Adv. Anal. Chem. Instrum., 4, p. 117Collins, L.A., Franzblau, S.G., (1997) Antimicrob. Agents Chemother., 41, p. 1004Oh, Y.K., Nix, D.E., Straubinger, R.M., (1995) Antimicrob Agents Chemother., 39, p. 2104Cingi, M.R., De Angelis, I., Fortunati, E., Reggiani, D., Bianchi, V., Tiozzo, R., Zucco, F., (1991) Toxicol. In Vitro, 5, p. 119Denizot, F., Lang, R., (1986) J. Immun. Methods, 89, p. 271Borenfreund, E., Puerner, J.A., (1984) J. Tiss. Cult. Meth., 9, p. 7Melo, P.S., Maria, S.S., Vidal, B.C., Haun, M., Durán, N., (2000) In Vitro Cell Rev. Biol. Animal, 36, p. 539Melo, P.S., Durán, N., Haun, M., (2001) Toxicology, 159, p. 135Shrivastava, R., John, G.W., Rispat, G., Chevalier, A., Massingham, R., (1991) ATLA - Alt. Lab. Anim., 19, p. 39
Histological evaluation of the liver of mice with sarcoma-180 treated with salazinic acid
Abstract Many of the drugs used to fight cancer cells induce various damage causing hepatotoxic effects which are characterized by tissue changes. The aim of the study is to know the possible effects of salazinic acid on livers of mice exposed to Sacoma-180. The tumor was grown in the animals in ascitic form and inoculated subcutaneously in the axillary region of the mouse developing the solid tumor. Treatment with salazinic acid (25 and 50 mg/kg) and 5-Fluorouracil (20 mg/kg) started 24-hours after inoculation and was performed for 7 days. To verify these effects, the qualitative method of histological criteria investigated in liver tissue was used. It was observed that all treated groups showed an increase of pyknotic nuclei in relation to the negative control. There was an increase in steatosis in all groups compared to the negative control but there was a decrease in the groups treated with salazinic acid in the 5-Fluorouracil. There was no necrosis in the salazinic acid treated groups. However, this effect was seen in 20% of the positive control group. Therefore, it can be concluded that salazinic acid did not show hepatoprotective action on mice but demonstrated a decrease in steatosis and absence of tissue necrosis
Schistosoma mansoni: inflammatory foci around larvae in the peritoneal cavity of naive mice is radiosensitive
Chemical composition of essential oil extracted from leaves of Campomanesia adamantium subjected to different hydrodistillation times
- …