0000000000422157

AUTHOR

Cristina Ballester

Tratamientos terapéutica de la fisura anal crónica

Current treatment of chronic anal fissure continues to be based on conventional conservative measures in a high percentage of cases. What is known as chemical sphincterotomy aims to achieve a temporary decrease of anal pressures that allows fissures to heal. There are various alternatives such as nitroglycerine or diltiazem ointment and botulinum toxin injections. However, because of collateral effects and recurrences in the medium term, the definitive role of these treatments remains to be elucidated. Nevertheless, chemical sphincterotomy should be the first option in patients with a high risk of incontinence. "Open" or "closed" lateral internal sphincterotomy performed in the ambulatory s…

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Impact of Wind Electricity Forecasts on Bidding Strategies

The change in the generation mix from conventional electricity sources to renewables has important implications for bidding behaviour and may have an impact on prices. The main goal of this work is to discover the role played by expected wind production, together with other relevant factors, in explaining the day-ahead market price through a data panel model. The Spanish market, given the huge increase in wind generation observed in the last decade, has been chosen for this study as a paradigmatic example. The results obtained suggest that wind power forecasts are a new key determinant for supply market participants when bidding in the day-ahead market. We also provide a conservative quanti…

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Effects of renewables on the stylized facts of electricity prices

Abstract Many countries around the world have increased their renewable installed capacity due to a greater awareness of climate concerns. Under this new framework, with renewables being among the main generation sources, the literature warns of a dramatic change in price behaviour. Some of the most commonly claimed effects of having a significant proportion of renewable generating sources in the total electricity production mix include: (i) a systematic decrease in overall wholesale market prices, (ii) a higher occurrence of price jumps, and (iii) a significant increase in price volatility. The goal of the present study is to test whether these changes in price behaviour have actually come…

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Relaxation of the isolated human internal anal sphincter by sildenafil.

Abstract Background Hypertonicity of the internal anal sphincter (IAS) appears to be involved in the pathogenesis of anal fissure. The relaxant effects of sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, on isolated human IAS were investigated. Methods The efficacy (maximal effect, Emax) and potency (−log IC50, where IC50 is half-maximal inhibitory concentration) of the PDE5 inhibitors, sildenafil and zaprinast, and of nitric oxide donors, sodium nitroprusside and glyceryl trinitrate, as relaxants of histamine (0·1 mmol/l)-induced tone were examined in IAS strips under isometric contraction. The presence of PDE5 isoenzymes and changes in intracellular calcium and cyclic nucleot…

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Relaxation by β3-adrenoceptor agonists of the isolated human internal anal sphincter

In this study, responses of beta(3)-adrenoceptor agonists were examined on human isolated internal anal sphincter (IAS) in order to explore their relaxant effects on hypertonicity of IAS.The relaxant efficacy (E(max)) and potency (-logIC(50)) of BRL37344 and SR58611A, beta(3)-adrenoceptor agonists, were examined in contracted IAS muscle strips. The presence of beta(3)-adrenoceptors, and changes in intracellular calcium and cyclic nucleotide levels in IAS muscle were tested by Western blotting, epifluorescence microscopy and enzyme immunoassay, respectively.BRL37344 and SR58611A relaxed contracted IAS muscle (E(max)=27+/-3% and 35+/-3%; -logIC(50)=6.26+/-0.24 and 4.87+/-0.13; respectively). …

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