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Biomedical subjects

G Guidi

Publications and source records attributed to G Guidi.

At least 19 recordsLinked to original sources
PubMed2006

Tracheobronchial aspiration of foreign bodies: current indications for emergency plain chest radiography.

PURPOSE: The purpose of this study was to determine the role of plain chest radiography in the evaluation of patients with suspected foreign-body aspiration. MATERIALS AND METHODS: During a 5-year period, 31 patients (18 men and 13 women; age range 6 months to 85 years) were referred to our observation for clinical suspicion of foreign-body aspiration. Clinically, the patients presented with cough in 27/31 cases (87.1%), decreased breath sounds in 22/31 (71%), choking in 18/31 (58.1%), fever in 7/31 (22.6%) and cyanosis in 5/31 (16.1%). Suspected foreign-body aspiration had occurred 2-72 h before hospitalisation. Within 2 h of hospitalisation, all patients underwent plain chest radiography performed in the upright position (two projections) in 10/31 (32.3%) patients and in the supine decubitus position in the remaining 21 (67.7%) patients. Plain chest radiography was subsequently integrated with multislice computed tomography (MSCT) of the chest in 3/31 (9.7%) patients and with bronchoscopy in 27/31 (87.1%) patients. RESULTS: Plain chest radiography showed the presence of a foreign body in the tracheobronchial tree in 7/31 (22.6%) patients, who subsequently underwent successful bronchoscopy in all cases. Foreign bodies included tooth fragment (three cases), nail (two cases), metallic spiral of a ball-point pen (one case) and an earring (one case). In the remaining 24/31 patients, plain chest radiography was positive in 14 cases, showing atelectasis (seven cases), pneumonia (six cases), pulmonary hyperinflation (one case) and pneumomediastinum (one case). Such findings had been caused by an aspirated foreign body, which was subsequently removed by means of bronchoscopy in all 14 patients. Moreover, three of the remaining ten patients with negative plain chest radiograph were submitted to MSCT of the chest, which required in 1 case tracheobronchial aspiration of a foreign body that was subsequently removed by means of bronchoscopy. Overall, plain chest radiography showed the presence of foreign-body aspiration and/or pleuroparenchymal lesions in 21/31 patients (67.7%); bronchoscopy was positive in 23/27 patients (85.2%), localising the foreign body in the right main bronchus in 16/27 patients (59.3%), left main bronchus in 7/27 patients (25.9%), intermediate bronchus in 2/27 patients (7.4%) and right lower lobe bronchus in 2/27 patients (7.4%). No late complications were observed within 6 months of hospital discharge. CONCLUSIONS: Plain chest radiography remains the initial imaging modality for patients with clinically suspected tracheobronchial aspiration of a foreign body. Nevertheless, in the case of negative chest radiography and a clinical suspicion of foreign-body aspiration, MSCT-possibly integrated with virtual bronchoscopy-should be considered in order to avoid unnecessary bronchoscopy.

Adolescent↗
PubMed2005

Anticardiolipin antibodies in healthy and diseased dogs.

The concentrations of anticardiolipin immunoglobulin G (IgG) were measured in 134 healthy dogs and 63 diseased dogs by an elisa. The mean (sd) concentration in the healthy dogs was 5.40 (2.60) IgG phospholipid (gpl) units, and concentrations greater than 11 gpl were considered as above the normal range. On this basis, 30 (47.6 per cent) of the diseased dogs were within the normal range, with a mean of 5.45 (3.07) gpl and the other 33 had levels above the normal range (P<0.001); 19 of them had a mean level of 22.2 (5.66) gpl, 10 had a mean level of 49.1 (11.2) gpl, and four had a mean level of 85.8 (9.64) gpl. Levels above the normal range were more frequent in females (59.4 per cent) than in males (45.1 per cent), but were higher in males (45.5 [34.71] v 42.91 [22.0] gpl). In addition, they were more frequent and higher in older dogs (66.7 per cent, 40.4 [24.0] gpl) than in younger dogs (33.3 per cent, 33.5 [21.4] gpl).

Animals↗
PubMed2004

Effect of two gaps on the flux-lattice internal field distribution: evidence of two length scales in Mg(1-x)AlxB2 from muSR.

We have measured the transverse field muon spin precession in the flux-lattice (FL) state of the two-gap superconductor MgB2 and of the electron doped compounds Mg(1-x)AlxB2 in magnetic fields up to 2.8 T. We show the effect of the two gaps on the internal field distribution in the FL, from which we determine two coherence length parameters and the doping dependence of the London penetration depth. This is an independent determination of the complex vortex structure already suggested by the STM observation of large vortices in a MgB2 single crystal. Our data agree quantitatively with STM and we thus validate a new phenomenological model for the internal fields.

Journal Article↗
PubMed2004

A new HPLC method to determine glomerular filtration rate and effective renal plasma flow in conscious dogs by single intravenous administration of iohexol and p-aminohippuric acid.

A high-performance liquid chromatography method to determine iohexol (IOX) and p-aminohippuric acid (PAH) in the plasma of dogs is evaluated according to recovery, reproducibility, and linearity utilizing a gradient pump. The mobile phase consists of 50mM sodium dihydrogen phosphate with 0.5mM tetrabutylammonium chloride, the pH is adjusted to 4.1, methanol is added to the final ratio of 90:10 (v/v), the flow rate is set at 1 mL/min, and separation is achieved with an ODS2 Luna column. The UV detector is set at 254 nm. IOX and PAH are used for evaluation of the effective renal plasma flow (ERPF) and glomerular filtration rate (GFR). The present method tested in three dogs demonstrates the accuracy in the evaluation of ERPF and GFR. Because of its precision and simplicity and low cost, it can be considered a good tool for ERPF and GFR in small animal practice.

Animals↗
PubMed2003

[Solid pseudopapillary tumour of the pancreas. Report of a case].

Solid pseudopapillary pancreatic tumour is an uncommon disease including 2.7% of exocrine malignancies of the pancreas. Its low incidence is associated with an uncertain prognosis and with difficult diagnostic and therapeutic problems, despite routine use of ultrasonography, TC and RMN. A case of solid pseudopapillary pancreatic tumour in a young woman is reported: the clinicopathologic features, diagnostic imaging and surgical treatment are discussed. Surgery is the primary option. Prognosis is however not fully known. From a review of the literature it is suggested that these tumours should be regarded as potentially malignant.

Adult↗
PubMed2002

Prothrombotic effects and clinical implications of third-generation oral contraceptives use.

Although the use of oral contraceptives has been frequently associated with an increased risk of thromboembolic events, definitive prothrombotic mechanisms have not so far been fully elucidated. The aim of our investigation was the evaluation of the activities of antithrombin, protein C, protein S and the resistance to activated protein C in 137 healthy users of third-generation oral contraceptives and in 170 healthy women who were not consuming oral contraceptives. Women on oral contraceptives showed a marked prothrombotic pattern, characterized by reduced activities of antithrombin and protein S, and increased resistance to activated protein C. Nearby 50% of oral contraceptive users displayed activities of protein S below the lower value of the reference range (controls, 10%; P < 0.001). No significant differences were observed between two progestagens (desogestrel or gestodene) on the coagulation parameters tested. We believe that, due to the adverse effect on haemostasis, the administration of third-generation oral contraceptives should be carefully considered in women carrying prothrombotic abnormalities.

Adult↗
PubMed2001

Variation of plasma D-dimer following surgery: implications for prediction of postoperative venous thromboembolism.

The prognosis of venous thromboembolism is considerably influenced by an accurate and fast diagnosis. Although the role of D-dimer testing in the diagnosis of suspected venous thromboembolism is well established for outpatients, there is controversial evidence on the clinical usefulness of its measurement in surgical patients. In order to recognize patterns of variation of D-dimer following surgery and identify potential pitfalls in prediction of venous thromboembolic complications, plasma D-dimer was assayed in 30 patients undergoing major elective hip surgery and 20 patients undergoing laparoscopic cholecystectomy for acute cholecystitis. The postoperative variation of plasma D-dimer differed widely between the two subgroups. Patients undergoing laparoscopic cholecystectomy showed D-dimer concentrations persistently increased from the baseline to the 15th postoperative day, whereas patients undergoing hip surgery were characterized by a double peak, on the 1st and 7th postoperative days. Mean inter-individual daily coefficient of variations of plasma D-dimer throughout the postoperative period were 49% (range 39%-61%) for laparoscopic cholecystectomy and 101% (range 72%-156%) for orthopedic surgery. The markedly heterogeneous fluctuation of plasma D-dimer suggests that the postoperative activation of the hemostatic system depends on the type and time since surgery, thus limiting the clinical usefulness of D-dimer testing in the diagnostic approach to postoperative venous thromboembolism.

Arthroplasty, Replacement, Hip↗
PubMed2001

Velocity magnitude estimation with linear arrays using Doppler bandwidth.

The dependence of pulsed wave Doppler bandwidth on parameters typical of linear transducer arrays used in commercial Duplex and color flow mapping systems is investigated experimentally. For a single flow line it is observed that this bandwidth generally depends not only on the scatterer velocity and the beam-to-flow angle, but also on the flow line range and orientation. This is due to the fact that in Duplex and color flow systems the transducer is differently focused in the scan and elevation planes and its aperture and focal lengths are often made to vary, depending on the distance of the flow line from the transducer. It is however experimentally demonstrated that, at points where the ultrasound beamwidths in the scan and elevation planes are both comparable to the sample volume length, the Doppler bandwidth is independent of the beam-to-flow angle. It is also shown that this invariance can be extended to other ranges by appropriately modifying the array aperture. Finally, as an application of this independence, the flow-line velocity magnitude in these beam regions is estimated with better than 5% uncertainty through a simple bandwidth measurement.

Ultrasonics↗
PubMed2001

Multigate doppler signal analysis using 3-D regularized long AR modelling.

Autoregressive (AR) modelling has already been proposed as an alternative to fast Fourier transform to process ultrasound (US) Doppler signals. Previous works introduced long AR models, set up under a regularization framework. The latter may be in 1-D (frequency) or 2-D (frequency and space or time). This study generalizes the spectrum regularization in the three dimensions frequency, space and time. The problem of the penalization function is addressed, and a new convex solution is proposed, taking into account possible nonstationarity of the Doppler signal. The parameter tuning is based on simulations using a standard Doppler signal model. The first results show that this processing improves the spectral estimation, and is well suited to flow interpretation.

Algorithms↗
PubMed2001

Biochemical risk factors for cardiovascular disease in an aged male population: emerging vascular pathogens.

The progressive increase of deaths and morbidity from cardiovascular disease (CVD) in most developed societies has led to the formulation of preventive strategies and application of several diagnostic guidelines. However, there is emerging evidence that most panels and algorithms are inadequate and require urgent revision and updating. Therefore, the aim of this study was the evaluation of a wide cardiovascular risk profile in elderly male patients with acute myocardial infarction (AMI) or peripheral occlusive disease (POD). The risk profile was assessed by measuring conventional serum lipid and lipoprotein levels and emerging parameters: lipoprotein(a) (Lp[a]), homocysteine (Hcy), and C-reactive protein (CRP). The concentration of triglycerides, Lp(a), Hcy and the total cholesterol/high-density lipoprotein (TC/HDL) ratio were significantly higher in both classes of patients than in a population of matched healthy controls and, similarly, patients with CVD displayed lower plasma values of HDL. No significant differences were observed for TC, low-density lipoprotein (LDL), and CRP. Patients with POD exhibited a marked atherogenic profile, as attested by substantially increased values of Hcy, Lp(a), triglycerides, and TC/HDL ratio. The frequency distributions of Lp(a) and Hcy concentrations were markedly shifted toward upper values in both classes of patients than in controls. In multivariate regression analysis, Lp(a) and Hcy were the best predictors for AMI, whereas Lp(a), Hcy, and the TC/HDL ratio were the best predictors for POD. Taken together, these data suggest that Lp(a) and Hcy excesses might exert a central role in the development of atherosclerotic disease in elderly male patients. Thereby, the inclusion of those tests, along with the TC/HDL ratio and other more conventional analyses in panels for the evaluation of the cardiovascular risk might be profitable in terms of effectual prevention.

Age Factors↗