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Biomedical subjects

A Corsetti

Publications and source records attributed to A Corsetti.

11 recordsLinked to original sources

Arabinose fermentation by Lactobacillus plantarum in sourdough with added pentosans and alphaalpha-L-arabinofuranosidase: a tool to increase the production of acetic acid.

Sixty-five strains of obligately and facultatively heterofermentative sourdough lactic acid bacteria were screened for their capacity to grow optimally in the presence of arabinose, ribose and xylose as carbon sources. Lactobacillus alimentarius 15F, Lact. brevis 10A, Lact. fermentum 1F and Lact. plantarum 20B showed higher growth rate, cell yield, acidification rate and production of acetic acid when some pentoses instead of maltose were added to the SDB medium. Lactobacillus plantarum 20B used arabinose also in a synthetic medium where complex growth factors such as yeast extract were omitted. Other Lact. plantarum strains did not show the same property. Pentosan extract was treated with alpha-L-arabinofuranosidase from Aspergillus niger or endo-xylanase from Bacillus subtilis to produce hydrolysates containing mainly arabinose and xylose, respectively. In particular, the hydrolysate containing arabinose substantiated the growth and the production of lactic acid and, especially, of acetic acid by Lact. plantarum 20B. Sourdough fermentation by Lact. plantarum 20B with addition of pentosan extract and alpha-L-arabinofuranosidase increased the acidification rate, titratable acidity and acetic acid content compared with traditional sourdough. A facultatively heterofermentative strain, Lact. plantarum 20B, also produced a sourdough with an optimal fermentation quotient.

Acetic Acid

Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1.

Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric and n-valeric acids, acting in a synergistic way, was responsible for the antimould activity. Caproic acid played a key role in inhibiting mould growth.

Antifungal Agents

Control of hypertension in Italy: results of the "Study on Antihypertensive Treatment in General Practice (STAP)". Physicians Taking Part in STAP.

BACKGROUND: Various epidemiological surveys from different countries have documented the unsatisfactory control of arterial hypertension. The aim of this study was to assess the current status of treatment and control of hypertension in Italy. METHODS: A random sample of general practitioners (GP) working in several Aziende Sanitarie Locali (Local health offices-ASL) throughout Italy were invited to take part in the study. Each doctor had to recruit a random sample of 15-20 hypertensive patients receiving antihypertensive drugs among those attending his/her office for any reason. A standard medical history, specifically oriented to hypertension and its pharmacological treatment, was taken for each patient. Three blood pressure (BP) measurements were made, with the patient seated for at least 5 minutes, using an accurate automatic device (A&D UA-732), and the mean was taken as each patient's BP. RESULTS: A total of 73 GPs (17% of the invited sample), working in 14 Italian ASL (six in the north of the country, four in the center and four in the south and islands), agreed to participate in the study. They recruited an average of 17 patients each, for a total of 1204 hypertensive subjects (663 women and 541 men) 633 of whom were 65 years old or more, mean age 64 +/- 11 years, range 25-94 years. More than half (56%) had been taking antihypertensive drugs for at least five years; 42% were taking one drug, 40% two, 16% three and 2% four drugs. Respectively, 63% and 23% had systolic BP (SBP) > or = 140 and > or = 160 mmHg; 28% and 14% had diastolic BP (DBP) > or = 90 and 95 mmHg. In 71%, BP was < 160/95 mmHg, but only 33% had BP lower than 140/90 mmHg. BP control was similar in males and females, but worse in the elderly. Nine percent of patients complained of symptomatic side effects, usually mild. Only 8% admitted to poor compliance with the antihypertensive therapy, and their BP was significantly less well controlled. CONCLUSIONS: Control of BP in patients receiving antihypertensive drugs is still far from optimal in Italy, just as in other countries. This situation seems more related to the fact that doctors do not tackle the problem aggressively, than to the patients' degree of compliance with therapy.

Aged

Preoperative ICU tours: are they helpful?

BACKGROUND: Although preoperative education decreases the anxiety of patients and family members, the usefulness of a preoperative tour of the ICU has not been studied. In this study, the effect of an ICU tour on the anxiety levels of patients (n = 92) and family members (n = 91) before and after cardiac surgery was examined. METHODS: Using a pretest-posttest quasi-experimental design, patients and family members were assigned to a control group, which received preoperative teaching only (patients, n = 48; family members, n = 48), or to an experimental group, which received preoperative teaching with an ICU tour (patients, n = 44; family members, n = 43). Patients and family members completed two measures of anxiety, the State Trait Anxiety Inventory and a visual analog scale, before and after the intervention. After their first postoperative visit, family members completed the measures again. Repeated measures analysis of variance was used to compare anxiety levels after the intervention. In addition, patients completed the Patient Perception of the ICU Tour Questionnaire after transfer from the ICU. RESULTS: Although patients and family members had a decrease in anxiety after cardia surgery teaching, the decrease was not due to an ICU tour. However, the majority of patients who toured the ICU perceived the tour as beneficial and recommended a tour for future patients. CONCLUSIONS: ICU tours are included in many cardiac surgery educational programs. The majority of patients in this study perceived a benefit or a future benefit from an ICU tour, even though the tour did not significantly reduce the anxiety of the patients or family members.

Adult

The proteolytic system of Lactobacillus sanfrancisco CB1: purification and characterization of a proteinase, a dipeptidase, and an aminopeptidase.

A cell envelope 57-kDa proteinase, a cytoplasmic 65-kDa dipeptidase, and a 75-kDa aminopeptidase were purified from Lactobacillus sanfrancisco CB1 sourdough lactic acid bacterium by sequential fast protein liquid chromatography steps. All of the enzymes are monomers. The proteinase was most active at pH 7.0 and 40 degrees C, while aminopeptidase and dipeptidase had optima at pH 7.5 and 30 to 35 degrees C. Relatively high activities were observed at the pH and temperature of the sourdough fermentation. The proteinase is a serine enzyme. Urea-polyacrylamide gel electrophoresis of digest of alpha s1- and beta-caseins showed differences in the pattern of peptides released by the purified proteinase and those produced by crude preparations of the cell envelope proteinases of Lactobacillus delbrueckii subsp. bulgaricus B397 and Lactococcus lactis subsp. lactis SK11. Reversed-phase fast protein liquid chromatography of gliadin digests showed a more-complex peptide pattern produced by the proteinase of Lactobacillus sanfrancisco CB1. The dipeptidase is a metalloenzyme with high affinity for dipeptides containing hydrophobic amino acids but had no activity on tripeptides or larger peptides. The aminopeptidase was also inhibited by metal-chelating agents, and showed a broad N-terminal hydrolytic activity including di- and tripeptides. Km values of 0.70 and 0.44 mM were determined for the dipeptidase on Leu-Leu and the aminopeptidase on Leu-p-nitroanilide, respectively.

Amino Acid Sequence

[Magnetic resonance angiography of the portal vein in liver transplant recipients].

This work was aimed at investigating the diagnostic accuracy of Magnetic Resonance Angiography (MRA) in the study of the portal vein in liver transplant recipients. Ten patients (7 men and 3 women; mean age: 45 years) were examined 7-180 days after transplantation. The indications to liver transplant follow: post-infective active chronic hepatitis (4 patients), post-alcoholic chronic hepatitis (2 patients), HCC (2 patients), sclerosing cholangitis (1 patient) and primary biliary cirrhosis (1 patient). MRA images were acquired with the 2D TOF technique (TR 50 ms, TE 6.9 ms; FA 30 degrees, 40 slices; 6-mm thickness with 1-mm overlapping; 2 averages; 7.06 TA; matrix: 192 x 256). Axial scans were reconstructed with the MIP technique. Phase contrast sequences with retrospective cardiac triggering were also acquired for flow quantitation (TR/TE/FA: 26/9.3/20 degrees; FOV 150; matrix: 96 x 128; 4 averages, VENC = 20 cm/s). MRA yielded good quality images of the anatomy of the main portal vein and of the bifurcation in all cases, while a signal loss was observed in the peripheral branches. In all cases, the anastomosis could be studied at the portal vein. On MIP reconstructed images, the anastomosis appeared as a relative stenosis (4), while on 2D images it appeared as a small hypodense area on the vessel margin, because of the slight paramagnetic effect of the vascular suture. No thrombi were depicted in any patient and flow was hepatopetal in all cases. In conclusion, MRA is a useful tool for portal system studies in liver transplant recipients, because it permits the panoramic depiction of the portal system and the quantitation of flow (10).

Female

[Carcinoma of the pancreas. Typical and atypical aspects using midfield-strength magnetic resonance].

Until few years ago, MR assessment of pancreatic carcinoma was thought to be feasible only with high-strength equipment, but today also low- and midfield units allow pancreatic lesion detection, thanks to parameter optimization. The authors retrospectively analyzed the MR findings of 57 patients examined with a midfield MR unit; all the patients had clinically suspected pancreatic carcinoma, which was confirmed in 54 cases. The lesions were more easily detected using T1-weighted sequences, thanks to their high intrinsic contrast, while T2-weighted sequences often confirmed the glandular changes already depicted by T1-weighted sequences. MRI correctly depicted vascular and lymph node involvement and detected liver metastases with no i.v. contrast agent injection. The only limitations of this technique are the unfeasibility of MR exams of diagnostic value in uncooperative patients (5% of cases) and the very similar MR features of parenchymal scars, due to previous acute pancreatitis, to those of pancreatic carcinoma. In conclusion, CT remains the gold standard in the study of pancreatic cancers, but midfield strength MRI, if correctly performed, can be proposed as a complementary tool to CT, especially in questionable cases and in the patients with known reactions to iodinated contrast agents.

Aged

[Assessment with magnetic resonance of laryngeal and oropharyngeal movements during phonation].

The latest MR units are provided with the Turbo-Field-Echo technique which permits gradient-echo imaging with very short TE and TR and is optimized to yield the highest possible image quality within a very short acquisition time--i.e., less than 5 seconds. This dynamic study was aimed at depicting normal laryngeal and oropharyngeal movements during maximal inspiration and the prolonged uttering of vowels, in both a normal and a loud voice. We examined 10 healthy volunteers (7 men and 3 women) with an 0.5-T superconductive unit (Gyroscan T5 III, Philips Medical System). We used Turbo-Field-Echo sequences with the following acquisition parameters: TR 12 ms, TE 6 ms, flip angle 30 degrees, 4 acquisitions, acquisition time: 5 seconds. A single coronal scan was acquired at the larynx, while a midsagittal scan and 2 coronal scans were acquired at the oropharynx. The volunteers were asked to breathe in long and deep, to prolong the emission of the vowel [i] during laryngeal studies and to prolong the emission of the fundamental vowels [a], [i] and [u] in a normal (50 db) and a loud (70 db) voice during oropharyngeal studies. The movements of true and false vocal cords were clearly depicted in all the volunteers, and the activity of the different anatomical structures of the oropharyngeal cavity (lips, tongue, hard and soft palate, pharynx and epiglottis) was also demonstrated. During vowel production in a loud voice, the vocal tract was enlarged at the oral cavity for the vowels [a] and [u] and at the pharynx for the vowel [i]. To conclude, fast MRI with midsagittal scans is the best imaging modality to study different vocal tract patterns during speech and can thus replace midsagittal radiography and xeroradiography in the study of vowel production.

Adult