Biomedical subjects

S Spadaro

Publications and source records attributed to S Spadaro.

5 recordsLinked to original sources

PubMed2006

Solution-deposited microstructures based on aluminum-tris-hydroxyquinoline.

Iridescent organic films consisting of quasi-parallel wire-like microstructures are grown by castings from ethanol solutions containing mixtures of aluminium-tris-hydroxyquinoline and 1,10-phenanthroline. Spectrophotometric measurements carried out in the ultraviolet-visible range indicate that the microstructured films have angular-dependent optical behaviour, which is motivated by a refractive-index modulation over dimensions that are comparable to visible-light wavelengths. According to the results of investigations carried out by means of optical microscopy, atomic force microscopy (AFM), and scanning near-field optical microscopy (SNOM), the refractive-index modulation originates from a thickness modulation and a phase separation that occurs as the aluminium-tris-hydroxyquinoline and phenanthroline co-crystallize, with the former material being arranged to form a green luminescent pattern on the top of the latter one.

Journal Article↗

PubMed2001

Orolaryngeal sarcoidosis presenting as obstructive sleep apnoea.

A 53-year-old man was evaluated for snoring, dysphagia for solid foods and difficulty of breathing and a polysomnographic recording was consistent with a diagnosis of obstructive sleep apnoea syndrome (OSAS). A flexible fiberoptic bronchoscopy (FFB) showed the presence of a nodular lesion of the posterior ventral surface of the tongue strictly connected to the left lateral border of the epiglottis. The biopsy specimen taken from the lesion was consistent with sarcoidosis. No involvement of pulmonary parenchyma, lymph nodes or other organs was recognized. After two months of steroid treatment, symptoms disappeared and resolution of the nodular lesion at the FFB and normalization of the polysomnographic recording were observed. This is the first report of orolaryngeal sarcoidosis associated with OSAS as the only clinical presentation of the disease.

Bronchoscopy↗

PubMed2000

Role of spirometric and arterial gas data in predicting pulmonary complications after abdominal surgery.

The aim of this study was to evaluate the predictive value of preoperative spirometric and arterial gas data on severe pulmonary complications (PC) after elective abdominal surgery. We retrospectively studied 480 patients, 254 males and 226 females, mean (SD) age 63 (11) years, at risk for PC according to standardized criteria, who underwent laparotomy for resection of gallbladder for gallstones (44% of patients), resection of colon, rectum or stomach for malignant tumours (37%), and other abdominal surgery (19%). The overall incidence of postoperative PC was 18%. In a logistic regression analysis adjusted for smoking habit and clinical history of chronic bronchitis, FEV1<61% of predicted [odds ratio (OR)=16.86, 95% confidence interval (95%CI)=5.62-50.58] and PaO2<9.33 kPa (OR=6.42, 95%CI=2.48-16.61) were the main determinants of PC. Ischaemic heart disease (OR=3.44, 95%CI=1.08-10.93), operation for malignant tumours (OR=3.24, 95%CI=1.75-6.00) and age (OR=1.04, 95%CI=1.00-1.08) were also independent predictors of PC. Patients with moderate-to-severe airway obstruction combined with hypoxaemia had a significant higher risk of PC in comparison with patients with a normal respiratory pattern. Taking into account age, type of operation, and comorbidity, a preoperative respiratory functional assessment could be useful in identifying an increased risk of major PC in selected patients.

Abdomen↗

PubMed2000

Accuracy of indirect estimation of oxyhaemoglobin saturation in patients with respiratory failure.

The indirect estimate of oxyhaemoglobin saturation (Sa,O2) is largely used in the management of patients with respiratory failure. The aim of this study was to evaluate the accuracy of the Sa,O2 values calculated by using both the Siggaard-Andersen (SA) and the Severinghaus (SE) equation, in comparison with the real Sa,O2 values measured by a co-oximeter. A total of 558 arterial blood samples were analysed. On average, only a slight overestimation was found for Sa,O2 estimated by the SA (2.35 +/- 5.75%) and the SE (2.37 +/- 5.65%) equations in comparison with the real values. However, a difference higher than 5% between estimated and real Sa,O2 values was demonstrated in more than 20% of the blood samples evaluated. This difference was higher than 10% in 9% of the samples, with similar results obtained with the two equations. The discrepancy between real and estimated values, probably due, at least in part, to errors in measurement of arterial oxygen tension (Pa,O2) and pH, was maximally evident for Sa,O2 values lower than 70%. An indirect estimate of Sa,O2 is not homogeneously accurate, and the clinical consequence of this finding might be especially dangerous in monitoring patients with severe respiratory failure.

Humans↗

PubMed1999

Optimization of Pseudomonas cepacia lipase preparations for catalysis in organic solvents.

The activity of different lipase (from Pseudomonas cepacia) forms, such as crude powder (crude PC), purified and lyophilized with PEG (PEG + PC), covalently linked to PEG (PEG-PC), cross-linked enzyme crystals (CLEC-PC), and immobilized in Sol-Gel-AK (Sol-Gel-AK-PC) was determined, at various water activities (aw), in carbon tetrachloride, benzene and 1,4-dioxane. The reaction of vinyl butyrate with 1-octanol was employed as a model and both transesterification (formation of 1-octyl butyrate) and hydrolysis (formation of butyric acid from vinyl butyrate) rates were determined. Both rates depended on the lipase form, solvent employed, and aw value. Hydrolysis rates always increased as a function of aw, while the optimum of aw for transesterification depended on the enzyme form and nature of the solvent. At proper aw, some lipase forms such as PEG + PC, PEG-PC, and Sol-Gel-AK-PC had a total activity in organic solvents (transesterification plus hydrolysis) which was close to (39 and 48%) or even higher than (130%) that displayed by the same amount of lipase protein in the hydrolysis of tributyrin-one of the substrates most commonly used as standard for the assay of lipase activity-in aqueous buffer. Instead, CLEC-PC and crude PC were much less active in organic solvents (2 and 12%) than in buffer. The results suggest that enzyme dispersion and/or proper enzyme conformation (favored by interaction with PEG or the hydrophobic Sol-Gel-AK matrix) are essential for the expression of high lipase activity in organic media.

Biotechnology↗