964 resultados para Ester Hydrolysis
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Estudi amb la informació de base, la diagnosi i les accions proposades per tal de dur a terme una gestió apropiada del LIC Serra de Montgrony. La gestió està enfocada a fer compatibles les activitats antròpiques que es duen a terme a la zona amb la conservació de la biodiversitat de l’espai
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Objective This paper reviews the development and clinical validation of photodynamic diagnosis (PDD) of bladder cancer. Methods The authors reviewed the literature on the development of PDD, in particular the evidence for the clinical efficacy of hexaminolevulinate PDD in the diagnosis of bladder cancer. Results After initial work on ultraviolet cystoscopy following oral tetracycline, the focus of PDD research shifted to the use of synthetic porphyrins. First, the prodrug delta-aminolevulinic acid (ALA) was shown to cause a transient but significant accumulation of protoporphyrin IX (PpIX) in malignant or premalignant bladder tissue. Excitation by blue light leads to PpIX fluorescence (red), which distinguishes tumour from normal tissue (blue). Hexaminolevulinate (HAL, Hexvix), an ester of ALA, was then developed and has greater bioavailability and stability than the parent compound. It has been approved for clinical use in the diagnosis of bladder cancer. Clinical studies have shown that HAL PDD detects tumours, including carcinoma in situ (CIS), that are missed by conventional white-light cystoscopy. Conclusions HAL PDD is a valuable aid to the detection of bladder tumours, including CIS.
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The role of ATP hydrolysis during the RecA-mediated recombination reaction is addressed in this paper. Recent studies indicated that the RecA-promoted DNA strand exchange between completely homologous double- and single-stranded DNA can be very efficient in the absence of ATP hydrolysis. In this work we demonstrate that the energy derived from the ATP hydrolysis is strictly needed to drive the DNA strand exchange through the regions where the interacting DNA molecules are not in a homologous register. Therefore, in addition to the role of the ATP hydrolysis in promoting the dissociation of RecA from the products of the recombination reaction, as described earlier, ATP hydrolysis also plays a crucial role in the actual process of strand exchange, provided that the lack of homologous register obstructs the process of branch migration.
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Oseltamivir is the ester-type prodrug of the neuraminidase inhibitor oseltamivir carboxylate. It has been shown to be an effective treatment for both seasonal influenza and the recent pandemic 2009 A/H1N1 influenza, reducing both the duration and severity of the illness. It is also effective when used preventively. This review aims to describe the current knowledge of the pharmacokinetic and pharmacodynamic characteristics of this agent, and to address the issue of possible therapeutic drug monitoring. According to the currently available literature, the pharmacokinetics of oseltamivir carboxylate after oral administration of oseltamivir are characterized by mean ± SD bioavailability of 79 ± 12%, apparent clearance of 25.3 ± 7.0 L/h, an elimination half-life of 7.4 ± 2.5 hours and an apparent terminal volume of distribution of 267 ± 122 L. A maximum plasma concentration of 342 ± 83 μg/L, a time to reach the maximum plasma concentration of 4.2 ± 1.1 hours, a trough plasma concentration of 168 ± 32 μg/L and an area under the plasma concentration-time curve from 0 to 24 hours of 6110 ± 1330 μg · h/L for a 75 mg twice-daily regimen were derived from literature data. The apparent clearance is highly correlated with renal function, hence the dosage needs to be adjusted in proportion to the glomerular filtration rate. Interpatient variability is moderate (28% in apparent clearance and 46% in the apparent central volume of distribution); there is no indication of significant erratic or limited absorption in given patient subgroups. The in vitro pharmacodynamics of oseltamivir carboxylate reveal wide variation in the concentration producing 50% inhibition of influenza A and B strains (range 0.17-44 μg/L). A formal correlation between systemic exposure to oseltamivir carboxylate and clinical antiviral activity or tolerance in influenza patients has not yet been demonstrated; thus no formal therapeutic or toxic range can be proposed. The pharmacokinetic parameters of oseltamivir carboxylate after oseltamivir administration (bioavailability, apparent clearance and the volume of distribution) are fairly predictable in healthy subjects, with little interpatient variability outside the effect of renal function in all patients and bodyweight in children. Thus oseltamivir carboxylate exposure can probably be controlled with sufficient accuracy by thorough dosage adjustment according to patient characteristics. However, there is a lack of clinical study data on naturally infected patients. In addition, the therapeutic margin of oseltamivir carboxylate is poorly defined. The usefulness of systematic therapeutic drug monitoring in patients therefore appears to be questionable; however, studies are still needed to extend the knowledge to particular subgroups of patients or dosage regimens.
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Las tecnologías de información (TI) constituyen en la actualidad una herramienta fundamental para el logro de ventajas competitivas en un contexto sumamente cambiante. Resulta relevante conocer el impacto de su utilización sobre el desempeño de las organizaciones, en particular en sectores como el bancario, que realizan un uso intensivo de información. En el presente trabajo se desarrolla un modelo que posibilita evaluar el impacto de las inversiones en TI sobre la eficiencia de las entidades bancarias. Se utilizó la técnica Data Envelopment Analysis (DEA) como herramienta de medición de la eficiencia de acuerdo al modelo elaborado sobre la información obtenida de los estados contables de entidades bancarias de la República Argentina. Los resultados obtenidos demostraron que los bancos alcanzaron un buen nivel de eficiencia global. Se encontró que los más eficientes son las sucursales de entidades financieras del exterior y los bancos locales de capital extranjero.
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BACKGROUND: C iclosporine ( CsA), Tacrolimus (Tcl) and Infliximab (IFX) are effective rescue therapies in steroidrefractory ulcerative colitis (UC). Comparative studies are however m issing. M ETHOD: T his i s the retrospective analysis of treatment outcome for oral Tcl (n=27, initially 0.05mg/Kg twice daily, aiming for serum trough levels of 5-10 n g/mL), i ntravenous C sA ( n=23, 2 mg/kg/daily a nd then o ral CsA 5mg/kg/daily) and IFX ( n=43, 5 mg/kg intravenously at week 0, 2, 6 and then every 8 weeks) in patients with s teroid r efractory moderate to s evere UC enrolled i n the SWISS IBD cohort s tudy. After successful rescue therapy with Tcl o r C sA, t hiopurine m aintenance therapy or maintenance therapy with Tcl (in Tcl pretreated patients) was introduced. The endpoints analyzed steroid free r emission r ate (on the basis of m odified Truelove- Witts severity index (MTWSI)) and number of colectomies after 6 m onths. R ESULTS: A t 6 months, 26% ( 7/27) o f patients treated with T cl r emained i n steroid free remission (MTWSI score ≤4) compared to 30 % (7/23) on 18 droplets to the same extend under the linoleic acid treat, whereas lipid hydrolysis or loss was significantly increased in Huh-7 WT cells after 24h. Conclusions: Chronic alcohol feeding in obese, insulin-resistant rats exerts significant and synergistic effects on PNPLA3 mRNA expression, which correlated with triglyceride content. In v itro experiments suggest that PNPLA3 expression depends on the t ypes of d ietary f atty acids with polyunsaturated fatty a cids i nducing a nd monounsaturated fatty a cids inhibiting PNPLA3 mRNA. I148M polymorphism of PNPLA3 l eads to attenuation o f lipolytic processes resulting in fat accumulation in the cell. 20 CsA and 58% ( 27/41) o f patients t reated w ith IFX ( Tcl & CsA vs I FX p = 0 .018). S ignificant m ore patients had primary non response, loss of response or severe adverse events i n the CsA cohort ( 61%, 1 4/23) c ompared to Tcl cohort (33.3 % , 9/27), and IFX cohort (30%, 1 3/43) (p= 0.037). Colectomy rate was significantly higher after CsA (17.4 %, 4/23) compared to Tcl (3.7 %, 1/27) or IFX (2.3 %, 1/43) (p= 0.047).CONCLUSION: After s ix m onth, rescue therapy with I FX h ad t he l owest c olectomy r ate, significantly h igher steroid free r emission rate, a nd t he lowest rate of non-response, loss of response and severe adverse events compared to CsA or Tcl rescue treatment.
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Les indústries proveïdores de vàlvules de bola han adaptat, durant els últims 25 anys, els seus productes a les necessitats de la indústria química, sobretot plantes petrolíferes, petroquímiques i indústries farmacèutiques. L’estudi de les propietats físico-químiques dels materials, sobretot elastòmers i termoplàstics, i el perfeccionament de les eines per produir boles en sèrie fan possible la fabricació de vàlvules adequades per a una àmplia gama d’aplicacions. La gran majoria de les indústries proveïdores de vàlvules treballen a partir de dissenys i materials estandarditzats. El procés de producció segons necessitats especials definides és llarg i costós. L’enginyer és el responsable d’escollir el disseny i materials òptims per a cadascuna de les peces del producte, tant de metall, elastòmer o termoplàstic. En molts casos es requereix un producte absolutament òptim, amb l’assegurança de la reduïda provabilitat de fallida i de l’adequació total d’acord amb una necessitat concreta. Aquesta demanda de requisits comporta l’estudi exhaustiu del fluid, de la futura localització del producte i de l’ambient al qual estarà sotmès. Per tant, el fet d’estandarditzar i sistematitzar el procés de selecció de vàlvules de bola segons condicions preestablertes és una tasca important i útil per a la indústria del disseny i fabricació vàlvules de bola. L’objectiu d’aquest projecte és la creació d’una eina que sistematitzi i estandarditzi el procés de selecció d’una vàlvula de bola segons condicions preestablertes
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This paper studies whether firms' use of R&D subsidies and R&D tax incentives is correlated to two sources of underinvestment in R&D, financing constraints and appropriability. We find that financially constrained SMEs are less likely to use R&D tax credits and more likely to obtain subsidies. SMEs using legal methods to protect their intellectual property are more likely to use tax incentives. Results are ambiguous for large firms. For both having previous experience in R&D increases the likelihood of using tax incentives, while it reduces the likelihood of using exclusively subsidies, suggesting that the latter induce entry into R&D. Results imply that direct funding and tax credits do not have the same ability to address each source of R&D underinvestment, and that on average subsidies may be better suited than tax credits at least for SMEs. From a policy perspective these tools may be complements rather than substitutes.
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Aquest treball posa en pràctica l'adaptació d'una enquesta anomenada E-S-QUAL, que avalua la qualitat del servei en establiments virtuals. Es parteix de la tesi del doctor Cristóbal i es combina amb part de la tesi del doctor Granollers, concretament amb el model MPIU+Q. S'ha implementat un lloc web amb l'enquesta, ens hem posat en contacte amb un supermercat virtual (Plusfresh.com)i l'hem posada en maxa per a que els clients la contestessin. Finalment, s'ha fet una anàlisi de les dades recollides i s'han extret uns informes i conclusions.
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The concept of endocrine disruption emerged over a decade ago with the observation that several natural or industrial compounds can interfere with estrogen and androgen signaling, and thereby affect both male and female reproductive functions. Since then, many endocrine-disrupting chemicals (EDCs) have been identified and the concept has been broadened to receptors regulating other aspects of endocrine pathways. In that context, interference of EDCs with receptors regulating metabolism has been proposed as a factor that could contribute to metabolic diseases such as obesity and diabetes. We review recent studies showing that several pollutants, including phthalates and organotins, interfere with PPAR (peroxisome proliferator-activated receptors) nuclear receptors and may thereby affect metabolic homeostasis. Particular emphasis is given on the mechanisms of action of these compounds. However, unlike what has been suspected, we provide evidence from mouse models suggesting that in utero exposure to the phthalate ester di-ethyl-hexyl-phthalate most likely does not predispose to obesity. Collectively, these studies define a subclass of EDCs that perturb metabolic signaling and that we propose to define as metabolic disruptors.
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El projecte, té per objectiu el càlcul i disseny de les instal•lacions del Balneari de laPuda, situat a la ciutat de Banyoles, província de Girona.Les instal•lacions estudiades, s’esmenten a continuació;- Instal•lació d’aigua freda sanitària- Instal•lació d’aigua calenta sanitària- Instal•lació de climatització zona hotel- Instal•lació de calefacció zona termal- Climatització i tractament de l’aigua de les piscinesEl Balneari té una superfície construïda total de 6.192,54 m2 , distribuïda en tres plantes;planta soterrani, planta baixa i planta primera
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Size and copy number of organelles are influenced by an equilibrium of membrane fusion and fission. We studied this equilibrium on vacuoles-the lysosomes of yeast. Vacuole fusion can readily be reconstituted and quantified in vitro, but it had not been possible to study fission of the organelle in a similar way. Here we present a cell-free system that reconstitutes fragmentation of purified yeast vacuoles (lysosomes) into smaller vesicles. Fragmentation in vitro reproduces physiological aspects. It requires the dynamin-like GTPase Vps1p, V-ATPase pump activity, cytosolic proteins, and ATP and GTP hydrolysis. We used the in vitro system to show that the vacuole-associated TOR complex 1 (TORC1) stimulates vacuole fragmentation but not the opposing reaction of vacuole fusion. Under nutrient restriction, TORC1 is inactivated, and the continuing fusion activity then dominates the fusion/fission equilibrium, decreasing the copy number and increasing the volume of the vacuolar compartment. This result can explain why nutrient restriction not only induces autophagy and a massive buildup of vacuolar/lysosomal hydrolases, but also leads to a concomitant increase in volume of the vacuolar compartment by coalescence of the organelles into a single large compartment.
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The possible interactions between Delta9-tetrahydrocannabinol (THC) and nicotine remain unclear in spite of the current association of cannabis and tobacco in humans. The aim of the present study was to explore the interactions between these two drugs of abuse by evaluating the consequences of THC administration on the somatic manifestations and the aversive motivational state associated to nicotine withdrawal in mice. Acute THC administration significantly decreased the incidence of several nicotine withdrawal signs precipitated by mecamylamine or naloxone, such as wet-dog-shakes, paw tremor and scratches. In both experimental conditions, the global withdrawal score was also significantly attenuated by acute THC administration. THC also reversed conditioned place aversion associated to naloxone precipitated nicotine withdrawal. We have then evaluated whether this effect of THC was due to possible adaptive changes induced by chronic nicotine on CB1 cannabinoid receptors. The stimulation of GTPS-binding proteins by the cannabinoid agonist WIN 55,212-2 and the density of CB1 cannabinoid receptor binding labelled with [3H] CP-55,940 were not modified by chronic nicotine treatment in the different brain structures investigated. Finally, we evaluated the consequences of THC administration on c-Fos expression in several brain structures after chronic nicotine administration and withdrawal. c-Fos was decreased in the caudate putamen and the dentate gyrus after mecamylamine precipitated nicotine withdrawal. However, acute THC administration did not modify c-Fos expression under these experimental conditions. Taken together, these results indicate that THC administration attenuated somatic signs of nicotine withdrawal and this effect was not associated to compensatory changes on CB1 cannabinoid receptors during chronic nicotine administration. In addition, THC also ameliorated the aversive motivational consequences of nicotine withdrawal.
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Background: GTF2I codes for a general intrinsic transcription factor and calcium channel regulator TFII-I, with high and ubiquitous expression, and a strong candidate for involvement in the morphological and neuro-developmental anomalies of the Williams-Beuren syndrome (WBS). WBS is a genetic disorder due to a recurring deletion of about 1,55-1,83 Mb containing 25-28 genes in chromosome band 7q11.23 including GTF2I. Completed homozygous loss of either the Gtf2i or Gtf2ird1 function in mice provided additional evidence for the involvement of both genes in the craniofacial and cognitive phenotype. Unfortunately nothing is now about the behavioral characterization of heterozygous mice. Methods: By gene targeting we have generated a mutant mice with a deletion of the first 140 amino-acids of TFII-I. mRNA and protein expression analysis were used to document the effect of the study deletion. We performed behavioral characterization of heterozygous mutant mice to document in vivo implications of TFII-I in the cognitive profile of WBS patients. Results: Homozygous and heterozygous mutant mice exhibit craniofacial alterations, most clearly represented in homozygous condition. Behavioral test demonstrate that heterozygous mutant mice exhibit some neurobehavioral alterations and hyperacusis or odynacusis that could be associated with specific features of WBS phenotype. Homozygous mutant mice present highly compromised embryonic viability and fertility. Regarding cellular model, we documented a retarded growth in heterozygous MEFs respect to homozygous or wild-type MEFs. Conclusion: Our data confirm that, although additive effects of haploinsufficiency at several genes may contribute to the full craniofacial or neurocognitive features of WBS, correct expression of GTF2I is one of the main players. In addition, these findings show that the deletion of the fist 140 amino-acids of TFII-I altered it correct function leading to a clear phenotype, at both levels, at the cellular model and at the in vivo model.
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Rationale: Acute behavioural effects and motivational responses induced by nicotine can be modulated by the endocannabinoid system supporting the existence of a physiological interaction between these two systems. Objectives: The present study was designed to examine the possible involvement of the cannabinoid system in the anxiolytic- and anxiogenic-like responses induced by nicotine in mice. Methods: Animals were only exposed once to nicotine. The acute administration of low (0.05, sc) or high (0.8 mg/kg, sc) doses of nicotine produced opposite effects in the elevated plus-maze, i.e., anxiolytic- and anxiogenic-like responses, respectively. The effects of the pretreatment with the CB1 cannabinoid receptor antagonist, rimonabant (0.25, 0.5 and 1 mg/kg, ip), and the cannabinoid agonist, 9-tetrahydrocannabinol (0.1 mg/kg, ip), were evaluated on the anxiolytic- and anxiogenic-like responses induced by nicotine. Results: Rimonabant completely abolished nicotine-induced anxiolytic-like effects and increased the anxiogenic-like responses of nicotine, suggesting an involvement of CB1 receptors in these behavioural responses. On the other hand, 9-tetrahydrocannabinol failed to modify nicotine anxiolytic-like responses, but attenuated its anxiogenic-like effects. In addition the association of non-effective doses of 9-tetrahydrocannabinol and nicotine produced clear anxiolytic-like responses. Conclusions: These results demonstrate that the endogenous cannabinoid system is involved in the regulation of nicotine anxiety-like behaviour in mice, and provide new findings to support the use of cannabinoid antagonists in the treatment of tobacco addiction.