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S Distefano

Publications and source records attributed to S Distefano.

At least 19 recordsLinked to original sources
PubMed2001

Fluconazole susceptibility of Italian Candida dubliniensis clinical isolates determined by reference and simplified tests.

Candida dubliniensis ia an opportunistic pathogen mainly associated with oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. We recently recovered the first Italian clinical isolates of C. dubliniensis from the oral cavities of seven HIV-seropositive subjects. The in vitro susceptibility to fluconazole (FLCZ) of these isolates was determined according to the National Committee for Clinical Laboratory Standards (NCCLS) M27-A broth microdilution method for yeasts. All seven isolates of C. dubliniensis were susceptible to FLCZ (MICs < or =0.5 microg/ml). Results of this reference method were compared to those obtained with simplified tests, more adapted to routine evaluation in hospital laboratories. Fungitest and Sensititre YeastOne colorimetric microplate-based methods have been evaluated. The agar disk diffusion method has also been tested on two different media: RPMI 1640-2% glucose and High Resolution-2% glucose-0.5 microg/ml methylene blue. All of the simplified methods tested were able to correctly identify FLCZ-susceptibility of this group of Italian C. dubliniensis isolates.

Antifungal Agents↗
PubMed2000

Tabulation of alcohol content of beer and malt beverages.

We present data from the analysis of the alcohol content of 391 beers and malt beverages available for sale in the State of Washington. The beverages were tested by gas chromatography for their alcohol content. Considerable variability in the alcoholic strength was found, even within the same class. Overall, the range of concentrations was 2.92% (v/v) to 15.66% (v/v). The alcohol content of beverages consumed is a critical factor in Widmark or volume-of-distribution-type calculations used to estimate blood or breath alcohol content from patterns of alcohol consumption. Using the correct alcohol content for beer, when the brand is known, can make a significant difference in the reliability of the calculation, and the data presented here should assist with optimizing the accuracy of the calculation.

Beer↗
PubMed1999

Proteolytic cleavage of plant proteins by peroxisomal endoproteases from senescent pea leaves

The degradation of peroxisomal and nonperoxisomal proteins by endoproteases of purified peroxisomes from senescent pea (Pisum sativum L.) leaves has been investigated. In our experimental conditions, most peroxisomal proteins were endoproteolytically degraded. This cleavage was prevented, to some extent, by incubation with 2 mM phenylmethylsulfonylfluoride, an inhibitor of serine proteinases. The peroxisomal enzymes glycolate oxidase (EC 1.1.3.1), catalase (EC 1.11.1.6) and glucose-6-phosphate dehydrogenase (EC 1.1. 1.49) were susceptible to proteolytic degradation by peroxisomal endoproteases, whereas peroxisomal manganese superoxide dismutase (EC 1.15.1.1) was not. Ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) from spinach and urease (EC 3.5. 1.5) from jack bean were strongly degraded in the presence of peroxisomal matrices. These results indicate that proteases from plant peroxisomes might play an important role in the turnover of peroxisomal proteins during senescence, as well as in the turnover of proteins located in other cell compartments during advanced stages of senescence. On the other hand, our data show that peroxisomal endoproteases could potentially carry out the partial proteolysis which results in the irreversible conversion of xanthine dehydrogenase into the superoxide-generating xanthine oxidase (EC 1. 1.3.22). This suggests a possible involvement of the peroxisomal endoproteases in a regulated modification of proteins.

Journal Article↗
PubMed1999

Alcohol content of beer and malt beverages: forensic consideration.

Beer consumption is commonly an issue in a medico-legal setting, requiring estimates either of a likely blood alcohol concentration (BAC) for a given pattern of consumption or vice versa. Four hundred and four beers and malt beverages available for sale in the State of Washington were tested by gas chromatography for their alcohol content. Considerable variability in the alcoholic strength was found, even within the same class. Overall the range of concentrations was 2.92%v/v to 15.66%v/v. The mean alcohol concentration for ales was 5.51%v/v (SD 1.23%v/v), and for lagers, 5.32% (SD 1.43%v/v). Some specialty brews had characteristically higher or lower mean concentrations: ice beers 6.07%v/v, malt liquor 7.23%v/v, light beer 4.13%v/v, seasonal ales 6.30%v/v. Six brands of lager and four light beers account for the majority of all beer sales in the United States, and the mean alcohol concentration for these products was measured as 4.73%v/v and 4.10%v/v respectively. Few of the beers (17%) were labeled with respect to alcohol content, and in some cases, there was a significant disparity between the concentration listed on the label, and the measured alcohol concentration. Toxicologists need to exercise caution when performing Widmark type calculations, using all available information to select the most appropriate estimate for alcoholic strength of a beer or malt beverage.

Alcoholic Beverages↗
PubMed1998

A dehydrogenase-mediated recycling system of NADPH in plant peroxisomes.

The presence of the two NADP-dependent dehydrogenases of the pentose phosphate pathway has been investigated in plant peroxisomes from pea (Pisum sativum L.) leaves. Both enzymes, glucose-6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH; EC 1.1.1.44), were present in the matrix of leaf peroxisomes, and their kinetic properties were studied. G6PDH and 6PGDH showed a typical Michaelis-Menten kinetic saturation curve, and had specific activities of 12.4 and 29.6 mU/mg protein, respectively. The Km values of G6PDH and 6PGDH for glucose 6-phosphate and for 6-phosphogluconate were 107.3 and 10.2 microM, respectively. Dithiothreitol did not inhibit G6PDH activity. By isoelectric focusing of peroxisomal matrices, the G6PDH activity was resolved into three isoforms with isoelectric points of 5.55, 5.30 and 4.85. The isoelectric point of peroxisomal 6PGDH was 5.10. Immunoblot analyses of peroxisomal matrix with an antibody against yeast G6PDH revealed a single cross-reactive band of 56 kDa. Post-embedment, EM immunogold labelling of G6PDH confirmed that this enzyme was localized in the peroxisomal matrices, the thylakoid membrane and matrix of chloroplasts, and the cytosol. The presence of the two oxidative enzymes of the pentose phosphate pathway in plant peroxisomes implies that these organelles have the capacity to reduce NADP+ to NADPH for its re-utilization in the peroxisomal metabolism. NADPH is particularly required for the ascorbate-glutathione cycle, which has been recently demonstrated in plant peroxisomes [Jiménez, Hernández, del Río and Sevilla (1997) Plant Physiol. 114, 275-284] and represents an important antioxidant protection system against H2O2 generated in peroxisomes.

Ascorbic Acid↗
PubMed1998

Lipid peroxidation, tissue necrosis, and metabolic and mechanical recovery of isolated reperfused rat heart as a function of increasing ischemia.

Isolated Langendorff-perfused rat hearts, after 30 min of preperfusion, were submitted to increasing times of global normothermic ischemia (1, 2, 5, 10, 20 and 30 min) or to the same times of ischemia followed by 30 min of reperfusion. Analysis of malondialdehyde, ascorbic acid, oxypurines, nucleosides, nicotinic coenzymes and high-energy phosphates was carried out by HPLC on neutralized perchloric acid extracts of freeze-clamped tissues. In addition, maximum rate of intraventricular pressure development and cardiac output of malondialdehyde, lactate dehydrogenase, oxypurines and nucleosides were monitored during both preperfusion and reperfusion. Besides decreasing energy metabolites and nicotinic coenzyme pool, prolonged ischemia produced oxidation of significant amounts of hypoxanthine and xanthine to uric acid and generation of detectable levels of malondialdehyde (0.002 micromol/g dry weight). After oxygen and substrate readmission, tissue and perfusate malondialdehyde increased only if previous ischemia was longer than 5 min, while lactate dehydrogenase was detected in perfusate of reperfused hearts following 10, 20, and 30 min of ischemia. Highest values of tissue malondialdehyde and total malondialdehyde output were recorded in reperfused hearts subjected to 30 min of ischemia (0.043 micromol/g dry weight and 0.069 micromol/30 min/g dry weight, respectively). Since tissue malondialdehyde was observed without detectable lactate dehydrogenase release in perfusate, it might be stated that malondialdehyde generation (i.e., lipid peroxidation) temporally preceded lactate dehydrogenase release (i.e., tissue necrosis). In reperfused hearts, evaluation of myocardial energy state and of mechanical recovery allowed us to determine times of ischemia beyond which reperfusion did not positively affect these metabolic and functional parameters. Main findings are that, under these experimental conditions, lipid peroxidation might be the cause and not the consequence of tissue necrosis and that duration of ischemia might be the factor deciding effectiveness of reperfusion.

Adenosine Triphosphate↗
PubMed1998

Evaluation of the effect of asthma inhalers and nasal decongestant sprays on a breath alcohol test.

The effects of eight prescription and non-prescription asthma inhalers and four over-the-counter nasal decongestants on the DataMaster, an evidential breath alcohol instrument, were evaluated. Subjects self administered the medication, and breath alcohol tests were administered immediately after use and following a 15 min waiting period. The only preparation which produced any effect on the instrument was Primatene Mist which contains 34% ethyl alcohol. The alcohol was, however, eliminated from the breath in the usual pattern of mouth alcohol elimination, and after 5 min there was no longer any effect. The inclusion of a 15 min deprivation period prior to an evidential breath test, during which time nothing is introduced into the mouth, is an adequate safeguard against interference with the test caused by alcohol containing inhalers.

Anti-Asthmatic Agents↗
PubMed1997

Characterization of endoproteases from plant peroxisomes.

In this work, the characterization of endoprotease (EP) isoenzymes in peroxisomes is reported for the first time in cell organelles purified from pea leaves (Pisum sativum L.). A comparative analysis of the endo-proteolytic activity in peroxisomes purified from young (15-day-old) and senescent (50-day-old) leaves was carried out. Peroxisomes purified from senescent leaves showed a much higher endo-proteolytic activity than organelles from young plants. A 16 h incubation with exogenous substrates was the threshold time for the detection of a linear increase in the endo-proteolytic activity of peroxisomes from senescent leaves. Three EP isoenzymes (EP2, EP4 and EP5), having molecular masses of 88, 64 and 50 kDa respectively, were found in young plants by using SDS/polyacrylamide-gradient gels co-polymerized with gelatin. However, four additional isoenzymes (EP1, EP3, EP6 and EP7), with molecular masses of 220, 76, 46 and 34 kDa respectively, were detected in senescent plants. All the isoenzymes detected in peroxisomes from both young and senescent leaves were neutral proteases. By using different class-specific inhibitors, the electrophoretically separated EP isoenzymes were characterized as three serine-proteinases (EP1, EP3 and EP4), two cysteine-proteinases (EP2 and EP6) and a metallo-proteinase (EP7), and EP5 might be a metal-dependent serine-proteinase. Moreover, a peroxisomal polypeptide of 64 kDa was recognized by an antibody against a thiol-protease. The serine-proteinase isoenzymes (EP1, EP3 and EP4), which represent approx. 70% of the total EP activity of peroxisomes, showed a notable thermal stability, not being inhibited by incubation at 50 degrees C for 1 h.

Aging↗
PubMed1997

Effects of increasing times of incomplete cerebral ischemia upon the energy state and lipid peroxidation in the rat.

Different times of incomplete cerebral ischemia (2, 4, 6, 8, 10 and 30 min) were induced by bilateral common carotid artery occlusion in anesthetized rats to evaluate the time course of changes in lipid peroxidation and energy metabolism. Analysis of malondialdehyde (used to assess the levels of lipid peroxidation), ascorbic acid, oxypurines, nucleosides, nicotinic coenzymes and high-energy phosphates, was carried out by high-performance liquid chromatography on neutralized perchloric acid extract of brain tissue. Under the present experimental conditions, malondialdehyde, nicotinic coenzymes and ATP catabolites (oxypurines and nucleosides) were affected by increasing times of ischemia, with respect to control sham-operated rats. In particular, the concentration of malondialdehyde, undetectable in control brains, increased from 1.26 nmol/g wet weight after 2 min of carotid clamping to 13.42 nmol/g wet weight at the end of 30 min of incomplete cerebral ischemia. The presence of oxidative stress was further supported by ascorbic acid depletion, which was particularly significant after 10 and 30 min of incomplete ischemia. Carotid clamping provoked an imbalance between energy production and consumption that was evidenced by a reduction in ATP and GTP concentrations and an increase in ATP degradation products such as AMP, oxypurines and nucleosides. A decrement in the sum of adenine nucleotides and the energy charge potential indicated a progressive malfunctioning of energy-producing metabolic cycles. A possible contribution to such a severe change in energy state might be related to depletion of NAD and NADP, particularly noticeable after the longest incomplete brain ischemia times, that should have provoked a consequent lessening of oxido-reductive reactions. Bilateral carotid clamping causes a significant reduction in brain oxygen and substrate supply that results in inhibition of energy metabolism and triggering of oxygen-radical-induced lipid peroxidation.

Animals↗
PubMed1997

Purification and properties of cytosolic copper, zinc superoxide dismutase from watermelon (Citrullus vulgaris Schrad.) cotyledons.

Cytosolic copperzinc-superoxide dismutase (CuZn-SOD I; EC 1.15.1.1) was purified to homogeneity from watermelon (Citrullus vulgaris Schrad.) cotyledons. The stepwise purification procedure consisted of acetone precipitation, batch anion-exchange chromatography, anion-exchange Fast Protein Liquid Chromatography, gel-filtration column chromatography, and affinity chromatography on concanavalin A-Sepharose. CuZn-SOD I was purified 310-fold with a yield of 12.6 micrograms enzyme per gram cotyledons, and had a specific activity of 3,450 units per milligram protein. The relative molecular mass for cytosolic CuZn-SOD was 34000, and it was composed by two equal subunits of 16.3 kDa. CuZn-SOD I did not contain neutral carbohydrates in its molecule, and its ultraviolet and visible absorption spectra showed two absorption maxima at 254 nm and 580 nm. Metal analysis showed that the enzyme contained 1 gram-atom Cu and 1 gram-atom Zn per mole dimer. Cytosolic CuZn-SOD was recognized by the antibody against peroxisomal CuZn-SOD from watermelon cotyledons, and its enzymatic activity was inhibited by this antibody. By IEF (pH 4.2-4.9), using a new method for vertical slab gels set up in our laboratory, purified cytosolic CuZn-SOD was resolved into two equal isoforms with isoelectric point of 4.63 and 4.66.

Cotyledon↗
PubMed1993

Presence and distribution of immunoreactive FMRFamide- and bovine pancreatic polypeptide-like peptides in a protochordate ascidian.

FMRFamide and bovine pancreatic polypeptide (BPP) immunoreactivities were detected in the cerebral ganglion and in the alimentary tract of the protochordate ascidian Styela plicata. Neurons expressing immunostain to FMRFamide were mainly found in the cortical zone of the ganglion and a network of immunoreactive beaded nerve fibers was present in the neuropil. Co-localization of FMRFamide- and BPP-like materials was demonstrated in few nerve cell bodies and both peptides likely play a neurotransmitter role. Parallel, endocrine-like cells containing FMRFamide-like materials were distributed among the esophageal and gastric epithelia, whereas no PP immunostaining was found. The tetrapeptide could be involved in the regulation of the digestive processes by means of endocrine and/or paracrine mechanisms.

Animals↗
PubMed1989

Hyperglycemia and prognosis of acute myocardial infarction in patients without diabetes mellitus.

The present study assessed the prognostic value of hyperglycemia--a common feature in the early phase of acute myocardial infarction (AMI)--in 330 nondiabetic patients. Seventy-nine known diabetics and 10 (3%) unknown diabetics--diagnosed before discharge by stable glycosylated hemoglobin greater than 6.9% and by oral glucose tolerance testing--were excluded. Thirty-three (10%) patients died. The mortality rate was higher in women, in patients with anterior AMI, in older patients (greater than 65 years) and in the presence of heart failure. It was highest in patients with cardiogenic shock (24/36 vs 9/294; p less than 0.0001). Admission plasma glucose was significantly higher in nonsurvivors than in survivors (163 +/- 60 vs 114 +/- 36 mg/dl; p less than 0.0001). Mortality rate increased with increasing admission plasma glucose: 3% in normoglycemic patients (less than or equal to 120 mg/dl) versus 15% in patients with borderline plasma glucose (121 to 180 mg/dl) versus 43% in hyperglycemic patients (greater than 180 mg/dl) (p less than 0.0001). Multiple regression (stepwise) analysis identified cardiogenic shock, infarct site and age as the major determinants of mortality, while admission plasma glucose failed to reach full statistical significance (p = 0.067). Hyperglycemia was related to all 3 of these independent prognostic factors; when age and infarct site were accounted for, hyperglycemia was significantly associated with heart failure only and this association was characterized by a remarkable mortality rate. In nondiabetic patients with AMI, hyperglycemia is a correlate of heart failure and, therefore, an important factor of prognosis.

Adult↗
PubMed1989

A case of anterior interosseous nerve syndrome.

Anterior interosseous nerve syndrome is a rare anomaly. The author describes a case which is of particular interest because of its iatrogenic pathogenesis and the clinical picture of isolated defect of flexor pollicis longus. The importance of electromyography is emphasized. Recovery occurred approximately 5 months after the onset of the neuropathy as a result of conservative treatment and without recourse to surgery.

Adolescent↗
PubMed1989

Neuropathy due to entrapment of the long thoracic nerve. A case report.

The author describes a case of severe paresis of the serratus anterior in a young volleyball player due to entrapment of the long thoracic nerve. This etiology is very rare, but if diagnosed and treated in the early stage, the lesion is reversible. The patient was completely cured 6 months later after the suspension of sports activity.

Athletic Injuries↗
PubMed1988

A case of pure dislocation of the ankle joint.

Pure dislocation of the ankle joint is extremely rare. This is due to the fact that the particular mechanism of injury required to produce it occurs equally rarely. The authors report a case in which a good clinical result was obtained with nonsurgical treatment.

Adolescent↗