974 resultados para Routes d’invasion
Resumo:
Ketoprofeeni on yleisesti käytetty ei-steroidinen tulehduskipulääke (NSAID) lampaiden ja sikojen kivunlievityksessä. Tietoa ketoprofeenin oikeista annosmääristä eri eläinlajeilla on saatavilla rajallisesti. Oikeaa lääkeainemäärää ei voida luotettavasti ekstrapoloida toisten eläinlajien tai ihmisten perusteella. Epäillyissä tulehduskipulääkemyrkytyksissä ongelmana on tietää, oliko eläimen saama lääkeannos toksinen. Lampailla tehdyn tutkimuksen tavoitteena oli selvittää, muuttuuko ketoprofeenin kinetiikka kymmenkertaisella yliannoksella, tutkia yliannoksen vaikutusta munuaisiin ja löytää yksinkertainen tapa diagnosoida yliannos virtsasta. Sioilla tehdyn tutkimuksen tavoitteena oli selvittää ketoprofeenin biologista käytettävyyttä ja ketoprofeenin farmakokinetiikkaa sioilla intravaskulaarisella, intramuskulaarisella ja peroraalisella annolla. Keskeiset tutkimuksessa määritettävät muuttujat olivat AUC0-_, Cmax ja tmax. Hyötyosuus laskettiin i.v. -annon perusteella. Kuudelle lampaalle annettiin 30 mg/kg i.v. -ketoprofeenia. Ketoprofeenin pitoisuuksia seurattiin 24 tunnin ajan plasmanäytteillä, joiden perusteella määritettiin farmakokineettiset parametrit. Veri- ja virtsanäytteistä tutkittiin muun muassa mahdollisesta munuaisvauriosta kertovia entsyymejä. 24 tunnin kuluttua lääkkeenannosta lampaat lopetettiin ja munuaiset tutkittiin histologisesti. Tutkittaville kahdeksalle sialle annosteltiin 3 mg/kg intravaskulaarista, intramuskulaarista ja oraalista ketoprofeenia sekä 6 mg/kg oraalista ketoprofeenia. Tutkimus suoritettiin satunnaistettuna vaihtovuorotutkimuksena. Ketoprofeenin pitoisuuksia seurattiin plasmanäytteillä 48 tunnin ajan lääkkeenannosta ja kaikille antotavoille laskettiin farmakokineettiset parametrit. Lisäksi tutkittiin valmisteiden biologinen samanarvoisuus. Molempien tutkimusten in vivo -kokeet suoritettiin Eläinlääketieteellisessä tiedekunnassa. Samoin munuaisten histologinen tutkimus ja virtsasta ja verestä tehdyt määritykset, lukuun ottamatta ketoprofeeninpitoisuuden analysointia. Plasman ketoprofeenipitoisuus analysoitiin korkean erotuskyvyn nestekromatografialla (HPLC). Ketoprofeenimääritykset ja farmakokineettinen analyysi suoritettiin Farmasian tiedekunnassa. Lampaiden kymmenkertainen ketoprofeeniyliannos oli toksinen. Seerumin urea- ja kreatiniinipitoisuus nousivat ja histologisissa näytteissä näkyi akuutti munuaistiehyen vaurio. Useiden entsyymien pitoisuus nousi virtsassa. Selvimmin ja nopeimmin nousi virtsan laktaattidehydrogenaasipitoisuus, jonka määrittäminen vaikuttaa potentiaaliselta tavalta diagnosoida ketoprofeenin toksinen annos. Ketoprofeenin eliminaation puoliintumisaika toksisella annoksella oli samaa suuruusluokkaa kuin aiemmissa tutkimuksissa terapeuttisella annoksella, joten yliannos ei muuttanut ketoprofeenin kinetiikkaa. AUC- ja Cmax -arvot olivat suhteessa suurempia kuin terapeuttisella annoksella, joten tutkimuksen perusteella kyseiset arvot eivät nousseet lineaarisesti annoksen noustessa toksiseksi. Sioille annetut ketoprofeenivalmisteet eivät olleet biologisesti samanarvoisia keskenään. Hyötyosuus oli erittäin hyvä kaikilla antotavoilla. tmax oli kaikilla antotavoilla hieman yli tunnin kuluttua lääkkeenannosta. Oraalisen 3 mg/kg -annoksen Cmax oli 5,1 mg/l ja AUC 32 mg l-1 h ja intramuskulaarisen vastaavat arvot olivat 7,6 mg/l ja 37 mg l-1 h. Oraalisen ketoprofeenin annostasojen AUC- ja Cmax -arvot korreloivat keskenään, joten ketoprofeenin kinetiikka oli lineaarista. Intravaskulaarisen ja oraalisen annon puoliintumisajoissa oli tilastollisesti merkitsevä ero. Ketoprofeenin jakautumistilavuudessa ja puhdistumassa ei ollut tilastollisesti merkitsevää eroa eri antotapojen välillä.
Resumo:
Uveal melanoma (UM) is the most common primary ocular malignancy in adults. In Finland, approximately 50 new cases are diagnosed yearly. Up to 50% of UM metastasize, mostly to the liver, although other organs are also affected. Despite improvements in the management of the primary tumour, the survival rates of patients with metastatic UM are poor. Until the 1970s, UMs were treated by enucleation i.e. removal of the eye. Currently, UM is usually treated by brachytherapy, which is known to influence tumour cells and blood vessels. UMs enucleated both primarily and secondarily after brachytherapy contain tumour-infiltrating macrophages, and a high number of macrophages in primary UM is associated with a shorter survival and a higher microvascular density (MVD) within the tumour tissue. The latter is independently associated with a shorter time to metastatic death. Macrophages have several diverse roles depending on their response to variable signals from the surrounding microenvironment. They function as scavengers, as producers of angiogenic and growth factors as well as proteases, which modulate extracellular matrix. Thus, tumour invasiveness and the risk for metastasis increase with increasing macrophage density. The aim of this study was to evaluate the effects of regression and progression of UM on macrophage numbers and microcirculation factors. Tumour regression is induced by primary brachytherapy, and tumour progression is evidenced by the development of metastases. Understanding the biological behaviour of UMs in the both states may help us in finding new treatment modalities against this disease. To achieve these aims case-control analyses of irradiated UMs and primarily-enucleated eyes (34 matched pairs) were performed. UMs were stained immunohistochemically to detect macrophages, extravascular matrix (EVM) loops and networks, and MVD. Following brachytherapy, a lower MVD was observed. The average number of macrophages remained unchanged. Considering that irradiated melanomas may still contain proliferating tumour cells, a clinically-relevant consequence of my study would be the reassurance that the risk for metastasis is likely to be reduced, given that the low MVD in untreated UMs indicates a favourable prognosis. The effect of progression on macrophages was studied in a paired analysis of primarily-enucleated UM and their corresponding hepatic metastases (48 pairs). A cross-sectional histopathological analysis of these pairs was carried out by staining both specimens in a similar way to the first study. MVD was greater in hepatic metastases than in corresponding primary tumours, and the survival of the patient tended to be shorter if hepatic metastases had a higher MVD. Hepatic metastases had also more dendritic macrophages than the primary UMs. Thus, the progression to metastasis seems to alter the inflammatory status within the tumour. Furthermore, determining MVD of biopsied hepatic metastases may serve as a supplementary tool in estimating the prognosis of patients with metastatic uveal melanoma. After irradiation, the majority of treated eyes have been clinically observed to have pigmented episcleral deposits. A noncomparative clinical case series of 211 irradiated UM eyes were studied by recording the number and location of pigmented episcleral deposits during follow-up visits after brachytherapy. For the first time, the study described pigmented episcleral deposits, which are found in the most UM eyes after brachytherapy, and proved them to consist of macrophages full with engulfed melanin particles. This knowledge may save patients from unnecessary enucleation, because episcleral pigmented deposits might be mistaken for extrascleral tumour growth. The presence of pigmented macrophage-related episcleral deposits was associated with plaque size and isotope rather than with tumour size, suggesting that, in addition to tumour regression, radiation atrophy of retinal pigment epithelium and choroid contributes to the formation of the deposits. In the paired (the same 34 pairs as in the first study) cross-sectional study of irradiated and non-irradiated UMs, clinically-visible episcleral deposits and migrating macrophages in other extratumoral tissues were studied histopathologically. Resident macrophages were present in extratumoral tissues in eyes with both irradiated and non-irradiated UM. Irradiation increased both the number of CD68+ macrophages in the sclera beneath the tumour and the number of clinically-observed episcleral macrophages aggregates. Brachytherapy seemed to alter the route of migration of macrophages: after irradiation, macrophages migrated preferentially through the sclera while in non-irradiated UMs they seemed to migrate more along the choroid. In order to understand the influence of these routes on tumour progression and regression in the future, labelling and tracking of activated macrophages in vivo is required.
Resumo:
Dehydrogenation of ammonia borane was carried out in fluor alcohol solvent in order to obtain compounds that are more likely candidates suitable for regeneration. Even though ammonia borane undergoes self-dissociation in 2,2,2-trifluoroethanol to liberate H-2, decent hydrogen release rates were obtained by using Co-Co2B, Ni-Ni3B, and Co-Ni-B nanocomposites as catalysts. These catalysts are magnetic in nature and hence can be separated from the reaction mixture using a magnet for re-use. The final by-product NH4+ B(OCH2CF3)(4)(-) obtained after the catalytic dehydrogenation of ammonia borane was thoroughly characterized using H-1, B-11, and C-13 NMR and IR spectroscopies. The FTIR data showed that the B-O bond in NH4+ B(OCH2CF3)(4)(-) is slightly weaker compared to boric acid. Preliminary investigations on the regenerative routes for ammonia borane from the by-product NH4+ B(OCH2CF3)(4)(-) showed indications of the formation of BNHx species. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Resumo:
The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident with the southern distribution limits of individual evolutionary lineages. These areas are important in terms of long-term species persistence and therefore important areas for conservation.
Resumo:
Alkali aluminosilicate glasses prepared by the gel and the melt routes have been investigated by Si-29 and Al-27 MAS NMR spectroscopy. It is found that Al has a tetrahedral coordination in the gel glasses modified with equivalent proportions of alkalis unlike in a pure aluminosilicate glass where Al has both four and six coordinations. Silicon is present as Q4 units in all the 5M2O 5Al2O3 9OSiO2 ( M = Li, Na and K) gel glasses studied whereas it is present in Q2 or Q3 species in the lithium aluminosilicate glasses of compositions 40Li2O x Al2O3 (1-x)SiO2 (1 less-than-or-equal-to x less-than-or-equal-to 15) and xLi2O 10Al2O3 (1-x)SiO2 (20 less-than-or-equal-to x less-than-or-equal-to 40). The combination of Q2 and Q3 is also found in certain sodium aluminosilicate glasses, but they change to Q2 and Q1 as the concentration of SiO2 decreases.
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A third mechanistic category of organic reactions, conceptually in-between kinetic and thermodynamic control, needs to be recognized, in order to obtain a proper mechanistic description of certain highly important organic reactions, but also to avoid controversy. In fact, an instance of debatable conclusions having been reached is already known. The term �pseudo-thermodynamic control� is proposed for this newly-defined category, which would include any reaction in which intermediates along different routes mutually interconvert. The new category would thus encompass a very large number of reactions, many of them of great utility.
Resumo:
Accessibility is a crucial factor for interaction between areas in economic, cultural, political and environmental terms. Therefore, information concerning accessibility is relevant for informed decision making, planning and research. The Loreto region in the Peruvian Amazonia provides an interesting scene for an accessibility study. Loreto is sparsely populated and because there are few roads in the region, in practice all movement and transportation happens along the river network. Due to the proximity of the Andes, river dynamics are strong and annual changes in water level combined with these dynamic processes constantly reshape accessibility patterns of the region. Selling non-timber forest products (NTFP) and agricultural products (AP) in regional centres is an important income source for local rain forest dwellers. Thus, accessibility to the centres is crucial for the livelihood of local population. -- In this thesis I studied how accessible the regional centre Iquitos is from other parts of Loreto. In addition, I studied the regional NTFP/AP trade patterns and compared them with patterns of accessibility. Based on GPS-measurements, using GIS, I created a time-distance surface covering Loreto. This surface describes the time-distance to Iquitos, along the river network. Based on interview material, I assessed annual changes to accessibility patterns in the region. The most common regional NTFP/AP were classified according to the amount of time they can be preserved, and based on the accessibility surface, I modelled a catchment area for each of these product classes. -- According to my results, navigation speeds vary considerably in different parts of the river network, depending on river types, vessels, flow direction and season. Navigating downstream is, generally, faster than upstream navigation. Thus, Iquitos is better accessible from areas situated south and south west of the city, like along the rivers Ucayali and Marañon. Differences in accessibility between different seasons are also substantial: during the dry season navigation is slower due to lower water levels and emerging sand bars. Regularly operating boats follow routes only along certain rivers and close to Iquitos transport facilities are more abundant than in more distant areas. Most of the products present in Iquitos market places are agricultural products, and the share of NTFP is significantly smaller. Most of the products were classified in product class 2, and the catchment area for these products is rather small. Many products also belonged to class 5, and the catchment area for these products reaches up to the edges of my study area, following the patterns of the river network. -- The accessibility model created in this study predicts travel times relatively well, although in some cases the modelled time-distances are substantially shorter than observed time-distances. This is partly caused by the fact that real-life navigation routes are more complicated than the modelled routes. Rain forest dwellers having easier access to Iquitos have more opportunities in terms of the products they decide to market. Thus, they can better take advantage of other factors affecting the market potential of different products. -- In all, understanding spatial variation in accessibility is important. In the Amazonian context it is difficult to combine the accessibility-related needs of the local dwellers with conservation purposes and the future challenge lies in finding solution that satisfy both of these needs.
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Several of the newly developed drug molecules experience poor biopharmaceutical behavior, which hinders their effective delivery at the proper site of action. Among the several strategies employed in order to overcome this obstacle, mesoporous silicon-based materials have emerged as promising drug carriers due to their ability to improve the dissolution behavior of several poorly water-soluble drugs compounds confined within their pores. In addition to improve the dissolution behavior of the drugs, we report that porous silicon (PSi) nanoparticles have a higher degree of biocompatibility than PSi microparticles in several cell lines studied. In addition, the degradation of the nanoparticles showed its potential to fast clearance in the body. After oral delivery, the PSi particles were also found to transit the intestines without being absorbed. These results constituted the first quantitative analysis of the behavior of orally administered PSi nanoparticles compared with other delivery routes in rats. The self-assemble of a hydrophobin class II (HFBII) protein at the surface of hydrophobic PSi particles endowed the particles with greater biocompatibility in different cell lines, was found to reverse their hydrophobicity and also protected a drug loaded within its pores against premature release at low pH while enabling subsequent drug release as the pH increased. These results highlight the potential of HFBII-coating for PSi-based drug carriers in improving their hydrophilicity, biocompatibility and pH responsiveness in drug delivery applications. In conclusion, mesoporous silicon particles have been shown to be a versatile platform for improving the dissolution behavior of poorly water-soluble drugs with high biocompatibility and easy surface modification. The results of this study also provide information regarding the biofunctionalization of the THCPSi particles with a fungal protein, leading to an improvement in their biocompatibility and endowing them with pH responsive and mucoadhesive properties.
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Texture development in commercially pure titanium during equal channel angular extrusion (ECAE) through Routes A, Be and C has been studied up to three passes at 400 C. Textures were measured using X-ray diffraction, while the microstructural analyses were performed using electron back-scattered diffraction as well as transmission electron microscopy. Occurrences of dynamic restoration processes (recovery and recrystallization) were clearly noticed at all levels of deformations. Finally, the textures were simulated using a viscoplastic polycrystal self-consistent (VPSC) model. Simulations were performed incorporating basal, prismatic and pyramidal slip systems as well as tensile and compressive twinning. The simulated textures corroborate well with experimental textures in spite of the occurrence of dynamic restoration processes. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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Chemical methods of synthesis play a crucial role in designing and discovering new and novel materials and in providing less cumbersome methods for preparing known materials. Chemical methods also enable the synthesis of metastable materials which are otherwise difficult to prepare. In this presentation, the various innovative chemical methods of synthesising oxide materials will be briefly reviewed with emphasis on soft-chemical routes. Electrochemical synthesis, ion-exchange method, alkali-flux method and some of the interaction reactions will be highlighted, besides topochemical aspects of solid state synthesis. Cuprate superconductors as well as intergrowth structures will also be examined.
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Synthesis of 5, 5-dimethyl- 7-methoxy-4 -oxatricyclo[4,3,1,0(3,7)]- decan-2-one 3a, a novel heterocyclic ring system present in morellin 1, and its 3-substituted derivatives 3b-e, is described from the Diels-Alder adducts 7, available from 1-methoxycyclohexa-1,4-dienes 4. Two routes, which involved the halocyclisation and the oxidative addition, were investigated for the conversion of the adducts 7 into 3. While the halocyclisation method resulted in mixtures, excellent yields of the target molecule were obtained by the second method. Solvolysis of the bromoether 9 resulted in a mixture of rearranged products 10, 13, 15 and 16.
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Two new synthetic routes for the preparation of the title compound and its 3-substituted derivatives, a novel ring system present in morellin and other related natural products, are reported from the readily available dihydroanisoles.
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Shock waves are one of the most efficient mechanisms of energy dissipation observed in nature. In this study, utilizing the instantaneous mechanical impulse generated behind a micro-shock wave during a controlled explosion, a novel nonintrusive needleless vaccine delivery system has been developed. It is well-known that antigens in the epidermis are efficiently presented by resident Langerhans cells, eliciting the requisite immune response, making them a good target for vaccine delivery. Unfortunately, needle-free devices for epidermal delivery have inherent problems from the perspective of the safety and comfort of the patient. The penetration depth of less than 100 mu m in the skin can elicit higher immune response without any pain. Here we show the efficient utilization of our needleless device (that uses micro-shock waves) for vaccination. The production of liquid jet was confirmed by high-speed microscopy, and the penetration in acrylamide gel and mouse skin was observed by confocal microscopy. Salmonella enterica serovar Typhimurium vaccine strain pmrG-HM-D (DV-STM-07) was delivered using our device in the murine salmonellosis model, and the effectiveness of the delivery system for vaccination was compared with other routes of vaccination. Vaccination using our device elicits better protection and an IgG response even at a lower vaccine dose (10-fold less) compared to other routes of vaccination. We anticipate that our novel method can be utilized for effective, cheap, and safe vaccination in the near future.
Resumo:
The protective ability of cytotoxic T cells (CTL) raised in vitro against Japanese encephalitis virus (JEV) was examined by adoptive transfer experiments. Adoptive transfer of anti-JEV effecters by intracerebral (i.c.) but not by intraperitoneal (i.p.) or intravenous (i.v.) routes protected adult BALB/c mice against lethal i.c. JEV challenge. In contrast to adult mice, adoptive transfer of anti-JEV effecters into newborn (4-day-old) and suckling (8-14-day-old) mice did not confer protection. However, virus-induced death was delayed in suckling mice compared to newborn mice upon adoptive transfer. The specific reasons for lack of protection in newborn mice are not clear but virus load was found to be higher in newborn mice brains compared to those of adults and virus clearance was observed only in adult mice brains but not in newborn mice brains upon adoptive transfer. Specific depletion of Lyt 2.2(+), L3T4(+) or Thy-1(+) T cell populations before adoptive transfer abrogated the protective ability of transferred effecters. However, when Lyt 2.2(+) cell-depleted and L3T4(+) cell-depleted effecters were mixed and transferred into adult mice the protective activity was retained, demonstrating that both Lyt 2.2(+) and L3T4(+) T cells are necessary to confer protection. Although the presence of L3T4(+) T cells in adoptively transferred effector populations enhanced virus-specific serum neutralizing antibodies, the presence of neutralizing antibodies alone without Lyt 2.2(+) cells was not sufficient to confer protection.
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An account is given of the research that has been carried out on mechanical alloying/milling (MA/MM) during the past 25 years. Mechanical alloying, a high energy ball milling process, has established itself as a viable solid state processing route for the synthesis of a variety of equilibrium and non-equilibrium phases and phase mixtures. The process was initially invented for the production of oxide dispersion strengthened (ODS) Ni-base superalloys and later extended to other ODS alloys. The success of MA in producing ODS alloys with better high temperature capabilities in comparison with other processing routes is highlighted. Mechanical alloying has also been successfully used for extending terminal solid solubilities in many commercially important metallic systems. Many high melting intermetallics that are difficult to prepare by conventional processing techniques could be easily synthesised with homogeneous structure and composition by MA. It has also, over the years, proved itself to be superior to rapid solidification processing as a non-equilibrium processing tool. The considerable literature on the synthesis of amorphous, quasicrystalline, and nanocrystalline materials by MA is critically reviewed. The possibility of achieving solid solubility in liquid immiscible systems has made MA a unique process. Reactive milling has opened new avenues for the solid state metallothermic reduction and for the synthesis of nanocrystalline intermetallics and intermetallic matrix composites. Despite numerous efforts, understanding of the process of MA, being far from equilibrium, is far from complete, leaving large scope for further research in this exciting field.