Carboxylic acids and skeletal muscle chloride channel conductance: effects on the biological activity induced by the introduction of an aryloxyalkyl group alpha to the carboxylic function of 4-chloro-phenoxyacetic acid.

2-(4-Chloro-phenoxy)propanoic and 2-(4-chloro-phenoxy)butanoic acids are compounds known to block chloride membrane conductance in rat striated muscle by interaction with a specific receptor. In the present study, a series of chiral analogues has been prepared and tested to evaluate the influence of a second aryloxy moiety introduced in the side-chain at a variable distance from the stereogenic centre. The results show that this chemical modification is detrimental for biological activity which, however, is increased by lengthening the alkyl chain up to three methylenic groups, then decreases to remain constant in the next analogues of the series. A possible explanation for this is proposed on the basis of steric effects and/or different approach of the molecules to the receptor.

[Ambulatory surgery: preoperative assessment]. / Chirurgia ambulatoriale: la valutazione preoperatoria.

Over the past 20 years public health expenditure has progressively increased for various reasons. With the aim of reducing public health expenditure and hospital stays, alternative models of public health care have been more widely adopted over the past two decades: Day Hospital, day surgery and ambulatory surgery. What is meant by ambulatory surgery is the clinical, organisational and administrative possibility of performing surgical operations and/or invasive and semi-invasive diagnostic procedures without hospitalisation of patients, in doctors' surgeries, outpatient departments or protected outpatient facilities. For both the patients and the centres providing the service to be able to exploit all the advantages stemming from this kind of health care provision, careful patient selection is mandatory, including assessment of the impact of any potential concomitant pathologies. Starting from their own personal experience and existing reports in the international literature, the authors analyse the impact that concomitant pathologies may have on patient selection for ambulatory surgery. The authors conclude that thorough preoperative evaluation of all the possible variables involved is the only way of ensuring the success of ambulatory surgery.

[The rationale in surgery of hepatic echinococcosis: total pericystectomy and resections. Personal experience]. / Il "razionale" nella chirurgia della echinococcosi epatica: la pericistectomia totale e le resezioni. Esperienza personale.

The Authors report their fifteen years experience in the surgical treatment of hepatic hydatid cysts. They emphasize the difference in the incidence of radical procedures (pericystectomy and hepatic resections) registered in the two periods examined (1980-83 and 1987-93), stressing the role of current diagnostic imaging techniques and improved surgical procedures which allow to perform standard operations for a radical treatment of hepatic hydatid cysts. Total pericystectomy is considered the procedure of choice; rarely it can't be performed (high vascular risk in central cysts located between portal and hepatic veins) and consequently subtotal pericystectomy or conservative treatment are the only possible procedures. Hepatic resection is preferred in case of multiple cysts involving the same lobe or when a giant hydatid cyst replaces the lobe. A further therapeutical resource--in radical procedures--is offered by the use of antihelminth drugs with marked antiparasitic action (albendazole).

Investigation of the optothermal properties of a new polymeric blend: polymethyl-methacrylate-poly (ethylene-co-vinylacetate).

A new polymeric blend, polymethyl methacrylate-poly (ethylene-co-vinylacetate) (PMMA-EVA) has been produced recently in our laboratories. The optothermal characterization of PMMA-EVA was carried out by measuring the ultraviolet photoacoustic spectra of PMMA, EVA, and PMMA-EVA (25 degrees C, 220-350 nm), of a PMMA-EVA blend (250-750 nm) at two temperatures (19 degrees C and 65 degrees C), and by measuring the scattering coefficient (at 514.5 nm) of PMMA-EVA versus the temperature in the range 38-86 degrees C. Our measurements show that, in the explored thermal range, the blend undergoes a phase transition when its optical properties change drastically. The peculiar optical and thermal properties observed appear attractive for possible applications as temperature-controlled optical devices.

[Internal biliary diversions in inoperable neoplasms of the biliary tract and pancreas]. / Le derivazioni biliari interne nelle neoplasie inoperabili delle vie biliari e del pancreas.

The authors report their experience with the treatment of mechanical jaundice in inoperable malignant neoplasms of the bile ducts and pancreas. They emphasize the importance of intrahepatic peripheral biliodigestive derivations (Soupault and Couinaud operation). After a review of the international literature, the authors consider the value of on accurate surgical strategy even in the presence of pathological and clinical features which may limit a radical choice.

Cholesteatoma surgery: open vs closed tympanoplasty.

The purpose of this report is to compare closed tympanoplasty (canal wall up) and open tympanoplasty (canal wall down) performed in ears with extensive cholesteatoma operated on and followed up during the past 11 years. The study has demonstrated that there are no significant differences between open and closed tympanoplasties in terms of both postoperative subjective problems and auditory results. The only definite difference relates to recurring cholesteatoma: canal wall-up operations are complicated by recurrence of cholesteatoma in a not insignificant number of ears and require a planned two-stage procedure in all the cases. By contrast, the postoperative clinical course of open tympanoplasties has been only rarely affected by cholesteatomatous complications. It is concluded that reduction of cholesteatoma recurrence to the greatest degree possible necessitates removal of the canal wall. Open tympanoplasty is an effective alternative for closed tympanoplasty in all cases in which there is a contraindication to preserving the canal wall and in all patients whose medical or social conditions prevent scheduling an operation in more stages.