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Biomedical subjects

G Simonetti

Publications and source records attributed to G Simonetti.

At least 109 records · Page 6Linked to original sources
PubMed1993

Serial determinations of leukocyte aggregation in patients with ischemic stroke.

The pattern of leukocyte aggregation and its possible relationship with the clinical outcome were evaluated in 35 untreated patients with acute cerebrovascular disease during each of the first three days of hospitalization. Although statistically significant differences were found when comparing patients and age and sex matched controls during any of the 3 days, a large overlapping of values was noted in each comparison. The overlapping was strongly reduced when the average 3-day value was compared. Similarly, when comparing subgroups of patients classified on the basis of their clinical status, the overlap of values observed during any of the 3 days dropped from 70% to 30% when considering the average 3-day levels of leukocyte aggregation. Furthermore, the level of correlation between leukocyte aggregation and size of cerebral infarction was better when considering the average 3-day value (p = .005) than the best single-day correlation (p = .01). These data suggest that the association between acute cerebrovascular ischemia and leukocyte rheology is better discovered when repeated evaluation of the latter are performed.

Age Factors↗
PubMed1993

[Palliative treatment of esophageal neoplastic stenoses with self-expanding metallic stents].

Thirty Strecker nickel-titanium self-expanding metallic stents were implanted in 20 patients with esophageal strictures and inoperable neoplasms in the Departments of Radiology of the University School of Medicine of Ferrara, Genoa, Novara and Rome, from March 1992 to April 1993; follow-up ranged 1 to 13 months. Thanks to the stents, esophageal strictures could be dilated, significantly reducing dysphagia and allowing the patients to return on to a solid diet. Radiological and endoscopic exams proved the efficacy of the stents in all but 2 patients in whom the tumors had invaded the stent lumen and caused obstruction. In all cases the stents were highly biocompatible and well tolerated. Neither major complications, such as perforation or bleeding, were observed, nor minor ones, such as fever or migration from the site of implant, which may occur with plastic prostheses. To conclude, self-expanding metallic stents used in clinical trials for 13 months proved an effective method in the palliative treatment of malignant esophageal strictures.

Aged↗
PubMed1993

[Gadolinium-DTPA dimeglumine administered orally for the study of the abdomen with magnetic resonance. Clinical evaluation and tolerance].

The tolerance to and the clinical value of a new positive oral contrast agent, Gd-DTPA-Dimeglumine, were evaluated. Ten healthy volunteers and 30 patients with abdominal and pelvic tumors were studied. Fourteen patients underwent MR scans only after cm administration, while 16 patients were examined both before and after. All images were obtained by means of a 1.5-T MR unit using SE and GE pulse sequences on the axial and coronal planes. Before the examination, a 1-mmol Gd-DTPA-Dimeglumine solution with mannitol and sodium citrate diluted in 1L of water was administered to all patients in 100-150-ml fractions. The product was well tolerated and its taste was good; adverse reactions were uncommon and mild. The solution was stable during gastrointestinal tract transit. Bowel signal was hyperintense on both GE and SE pulse sequences, which clearly demonstrated the bowel lumen distinguishing it from the surrounding fatty tissue and depicting even the smallest vascular structures. Moreover, from a clinical point of view, the hepatic, pancreatic and colic borders were better demonstrated in both normal and pathologic conditions.

Abdominal Neoplasms↗
PubMed1993

[Percutaneous transluminal renal angioplasty. Italian experience at 13 centers].

The data relative to 13 years' experience with percutaneous transluminal renal angioplasty (PTRA) in the 13 major interventional radiology centers in Italy were collected and analyzed to evaluate technical and clinical results. Our aim was to collect homogeneous results in a large series of patients, evaluating both the technical and the clinical success with a long-term follow-up (1 month-13 years). One thousand three hundred forty seven PTRA procedures (including 42 restenoses) in 1,073 patients were retrospectively reviewed. In 807 cases the cause of stenosis was atherosclerosis, in 442 cases fibromuscular dysplasia and in 24 cases arteritis in 12 cases, stenoses were present in patients that had undergone a surgical by-pass. Sixty-two stenoses in patients with solitary kidney and 102 in patients with renal failure were studied separately. The technical success (based on the morphology of the dilated tract) obtained in 91% of cases was considered, together with the clinical success (in 81% of cases), based on the decrease in blood pressure evaluated according to Martin's classification. The blood pressure values collected after the maneuver were also evaluated separately for the different types of stenosis etiology: atherosclerosis, fibromuscular dysplasia or arteritis; moreover, blood pressure was studied in solitary kidney patients and in those with renal failure. Complications were classified as major (4.2%) and minor (4.9%). The high success rate and the low incidence of complications we observed in our series suggest PTRA as the procedure of choice for high blood pressure patients with renal artery stenosis > 50% of the normal caliber.

Adolescent↗
PubMed1993

[Clinico-radiological correlation in thalassemia intermedia].

Fifteen thalassemia intermedia patients were considered, whose clinical and radiological findings were examined and compared. Eight patients underwent regular transfusion therapy. All patients underwent total body CT: the volume of ectopic erythropoiesis foci was calculated by a digital calculation algorithm (ROI volume). This work was aimed at correlating the quantitative measures of ectopic erythropoiesis assessed by CT with serum level of erythropoietin (EPO) and of trasferrin-free receptors (TfR) in both transfused and non-transfused patients, also considering the volume changes of ectopic erythropoiesis and bone changes over 36 months' follow-up. A direct correlation was demonstrated between serum transferrin and ectopic erythropoietic masses in transfusion-dependent patients: in fact, increased values of serum transferrin correspond to the enlargement of these masses and to bone lesion worsening.

Adolescent↗
PubMed1993

[Angiography with magnetic resonance in the study of portal hypertension. Clinical applications].

The role of MR angiography (MRA) was investigated in 31 patients with portal hypertension. The 2D time-of-flight (TOF) technique was used. All patients underwent CT first. MR angiograms were compared with DSA images in 15 cases and to duplex or color Doppler US scans in 16 cases. In 5 low-grade portal hypertension cases MRA showed splenoportal trunk enlargement and portal vein verticalization. In 26 patients with high-grade portal hypertension MRA allowed portosystemic shunts extent to be evaluated. Portal flow reduction or inversion and left gastric vein enlargement were always demonstrated by MRA in the patients with esophageal varices and azygos vein enlargement. MRA always correctly visualized cavernoma (5 cases) and portal vein thrombosis (9 cases). The diagnostic yield of MRA was greater than that of CT and SE MR sequences in 91% of cases. MRA provided the same information as (or more than) DSA and duplex US in 66% of cases.

Humans↗
PubMed1993

[MR staging in renal neoplasms. Comparison with surgical data].

Forty-six patients bearing renal lesions were studied with magnetic resonance (MR) imaging. A superconductive magnet (1.5 T) was used to stage the lesions according to Robson's criteria. A positive correlation between MR and pathologic results was observed in 40 cases. MR imaging overstaged 4 lesions: 2 of them for suspected infiltration of perirenal fat (MR stage II, versus pathologic stage I), one was a false-positive finding for lymph node metastasis (MR stage IIIb, versus pathologic stage II) and another one for suspected bowel loop infiltration (MR stage IVa, versus pathologic stage II). Two lesions were understaged: in one case bowel loop infiltration was missed by MR imaging (MR stage II, versus pathologic stage IVa) and another one for a false-negative lymph node metastasis (MR stage II, versus pathologic stage IIIb). In all the cases with involvement of renal vein and vena cava, MR imaging correctly demonstrated the presence of neoplastic thrombi.

Adult↗
PubMed1993

Antifungal agents. III. Naphthyl and thienyl derivatives of 1H-imidazol-1-yl-4-phenyl-1H-pyrrol-3-ylmethane.

The in vitro antifungal activities of some naphthyl and thienyl derivatives of 1H-imidazol-1-yl-4-phenyl-1H-pyrrol-3-ylmethane against Candida albicans and Candida spp are reported. The title derivatives were prepared starting from proper arylstirylketones, which were reacted with tosylmethylisocyanide (Tos-MIC) to afford the related 4-phenyl-1H-pyrrol-3-yl aryl ketones. Reduction of ketones to the corresponding carbinols followed by treatment of the last compounds with 1,1'-carbonyldiimidazole (CDI) gave the title imidazoles. The related N-methylpyrrole derivatives are also described.

Antifungal Agents↗
PubMed1992

Researches on antibacterial and antifungal agents, XIV: Thiophene analogues of bifonazole.

Some thiophene analogues of bifonazole have been synthesized by standard procedures and their antifungal activity has been tested against Candida albicans. Among test derivatives biphenyl-4-yl-5-chloro-thien-2-ylimidazol-1-ylmethane and its 5-deschlorothien-2-yl analogue resulted to be the most active. Their antifungal potency was almost comparable to that of control substances, such as miconazole, ketoconazole, and bifonazole. Replacement of benzene by the pyrrole ring in the biphenyl portion retained almost quantitatively the antifungal activity, whereas substitution with other azoles and with nitrogen alicyclic rings led always to less potent derivatives.

Antifungal Agents↗
PubMed1992

Antibacterial and antifungal agents. XV. Synthesis and antifungal activity of structural analogues of bifonazole and ketoconazole.

The synthesis and antifungal activities of the cis- and trans-1-acetyl-4-[4-[[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethy l)- 1,3-dioxolan-4-yl]-methoxy]phenyl)piperazines 3 and 4 are reported. Stereochemical assignments to diastereomeric pairs of cis/trans isomers were made on the basis of 1H- and 13C-NMR data. Among test derivatives the best activity was shown by the benzoyl esters of the cis- and trans-[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3-di oxolan-4- yl]methanols 9 and 10.

Antifungal Agents↗
PubMed1992

Electrochemical Ag+ for preservative use.

In contact experiments with different experimental conditions, electrochemical Ag+ solutions exhibited better antimicrobial effectiveness against bacteria, a yeast species, and a mold than did analogous silver solutions from inorganic salts. The particular characteristics of electrochemical Ag+, such as the mode of action, effectiveness at low concentrations, and stability, indicate that Ag+ could be used effectively in preservatives.

Anti-Bacterial Agents↗
PubMed1992

[Synchrotron radiation: a new source in x-ray mammography].

This work was aimed at evaluating the image quality obtainable in X-ray mammography using synchrotron radiation monochromatic lines. After a short review of the current mammographic techniques, the main features of synchroton radiation in the X-ray field are analyzed, especially of that emitted by the Adone storage ring. Its features are then compared with the radiation emitted by a Coolidge tube. The experimental unit used in this study, including beamline, monochromator and mammograph, is then described together with the experimental method for carrying out a series of experiments in the mammographic field employing both monochromatic lines (E = 17 keV) and white radiation from conventional sources. The first series of experiments is described, which employed standard phantoms: the dependence of resolution and contrast on both wavelength and thickness of breast specimens is reported. Several mammograms of neoplastic breast specimens were obtained after mastectomy: they were acquired using both synchrotron monochromatic lines and radiation emitted by a conventional tube and employing the same acquisition system. The comparison of the two series of images shows that synchrotron radiation can demonstrate a high number of anatomopathologic details with high definition, contrast and resolution which cannot be obtained by means of a conventional source. Our results appear very promising and suggest synchrotron radiation as the major tool in the early diagnosis of neoplastic breast lesions.

Breast Neoplasms↗