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Biomedical subjects

G Simonetti

Publications and source records attributed to G Simonetti.

At least 73 records · Page 4Linked to original sources
PubMed1997

Computed tomography-guided transsphenoidal closure of postsurgical cerebrospinal fluid fistula: a transmucosal needle technique.

BACKGROUND: Cerebrospinal fluid (CSF) fistula represents a fearful complication of transsphenoidal surgery and, despite careful intraoperative repair and prolonged postoperative lumbar CSF drainage, need for a new surgical intrasphenoidal plasty is not uncommon. METHODS: These cases prompted us to develop a simple, minimally invasive, harmless repeatable technique consisting of a computed tomography (CT)-guided intrasphenoidal injection of fibrin glue through a 12-gauge spinal needle. RESULTS: Five patients presenting with rhinoliquorrhea following a transsphenoidal approach for the excision of pituitary adenomas (three cases) and craniopharyngiomas (two cases) were treated successfully with the presented technique. In two cases the first attempt attained only partial success and therefore the procedure was repeated. In the last two cases, the injection of fibrin glue was preceded by 2 cc of fresh autologous blood, with the aim of enhancing the mechanisms of healing, possibly inducing adhesions and fibrosis. CONCLUSIONS: The proposed method of treatment for CSF leakage following transsphenoidal surgery may represent a valid alternative to the surgical option.

Adult↗
PubMed1997

Overcoming Streptococcus agalactiae in vitro resistance to imidazoles.

The increased diffusion of Streptococcus agalactiae in the urinary tract and vagina has affected the strain's resistance to antimicrobial agents, so we decided to study the possibility of overcoming its resistance to imidazoles. Our data suggest that overcoming S. agalactiae resistance to imidazoles in contact and growth culture tests depends partly on the electrical conductivity of the culture medium. Although imidazole contact activity and culture activity have different targets in cell structures, we have demonstrated that imidazole resistance in S. agalactiae cells in both types of tests can be affected by the same conditions regulating membrane permeability.

Anti-Bacterial Agents↗
PubMed1997

[Use of endoprosthesis in the treatment of airway pathology].

In patients affected by benign or malignant inoperable airway obstructions, therapeutical options include endoscopic treatment by Nd-YAG laser therapy, tracheobronchial dilatations with rigid or flexible bronchoscope, and inflating balloon dilators. Metal self-expanding or silicone stents allow to obtain stable results. Our experience is based on the use of 14 stents (10 Dumon and 4 Wallstent) in 13 cases of stenosis either due to vegetating malignant tumours not amenable to surgery or benign stenosis. In the following 24-48 hours both subjective and objective changes of the pulmonary function, blood gas analysis and radiologic aspects were observed. The results showed an improvement in the respiratory parameters and a sensible improvement in the quality of life.

Aged↗
PubMed1997

[Magnetic resonance features in cerebral primary lymphomas in non-immunocompromised subjects].

In the past few years, non-Hodgkin's lymphomas have been paid increasing attention to because of their recently increasing frequency. We reviewed the MR images of 17 patients with histologically proved primary CNS lymphoma, all of them immunocompetent at diagnosis. We studied the site, number and shape of the lesions, the presence and grade of edema and possible periventricular spread. The exams were performed with 0.5 T and 1.5 T MR units, using SE sequences on the sagittal, axial and coronal planes, before and after Gd-DTPA administration. The most typical neuroradiologic signs which may suggest the diagnosis of CNS lymphoma are deep or periventricular lesion site, diffuse and marked contrast enhancement, poorly defined borders, moderate edema surrounding the mass and a tendency to periventricular spread. MRI demonstrated 35 lesions in 17 patients. The lymphoma was unifocal in 9 cases (53%) and 7 lesions were localized in subtentorial site. Lesion size did not exceed 2 cm in 49% of cases, ranged 2-4 cm in 40% and exceeded 4 cm in 11% of cases only. These lesions and hypo- to isointense on T1-weighted images (97%) and their signal intensity varies on T2-weighted images, with mainly iso-/hypointense patterns (79%). All lesions enhanced after Gd-DTPA administration, 74% of them markedly and 26% moderately; enhancement was mostly homogeneous (80% of cases). Perilesional edema was observed in 74% of cases. In conclusion, MRI yields some useful information for the diagnosis of primary CNS lymphoma, but the clinical and radiologic signs of this lesion may exhibit aspecific signal features, meaning that no correct diagnosis can be made even in immuno-competent patients.

Adult↗
PubMed1997

[Treatment of intrahepatic arteriovenous fistula after biopsy. Results in 5 chemoembolization candidates with hepatocarcinoma].

We report our experience in the treatment of post-bioptic intrahepatic arterioportal fistulas (HAPF) in 5 patients with hepatocellular carcinoma (HCC) treated February, 1993, to May, 1995. In this retrospective study, we reviewed the imaging findings and clinical records of 3 men and 2 women (age range: 49-71 years) with HCC previously diagnosed with US, CT and biopsy. HAPF was detected by angiography (DSA) performed before chemoembolization (TACE). All HAPFs were referrable to biopsy (14-gauge Thru-Cut needle) and were treated with platinum coils positioned through coaxial catheters. TACE was performed immediately after or within a week of HAPF embolization. Therapeutic response after TACE was assessed on the basis of clinical and CT findings, while HAPF embolization success was assessed on the basis of DSA and color Doppler US findings. Reembolization was required in two patients--7 maneuvers in all in 5 patients. Complete HAPF occlusion was demonstrated in 4 patients during color Doppler follow-up and immediately after and at 13 and 24 months (in 2 patients) at DSA. Two of 5 patients died, one because of liver failure after 15 months' follow-up and the other because of complications related to liver transplantation at 11 months' follow-up. Of the extant 3 patients, one underwent liver transplantation and was followed-up for 25 months, while the other two are alive after 24 and 13 months, respectively. Our experience demonstrates that HAPF embolization in HCC patients is really useful for hemodynamic redistribution before TACE and to avoid further HAPF progression.

Aged↗
PubMed1997

[Description and preliminary clinical assessment of a digital chest radiographic system with selenium detector (Thoravision)].

The authors describe an innovative digital chest imaging system (Thoravision, Philips Medical System) based on a selenium detector directly converting X-rays in electric charges detectable by electrometers, amplified and digitalized to be sent to the imaging processor. The study was performed on a series of up to 7000 digital chest X-ray examinations and a sample of 173 cases was selected on the basis of particular diseases and pathologic patterns. In the latter case, digital and conventional radiographic techniques were compared. According to this analysis, the digital system was slightly superior in detecting anatomical details, small pleural effusions (3 cases) and slight low contrast interstitial pathologic changes, mainly in apical (12 cases) and retrocardiac (19 cases) lung areas. The conventional screen-film system better showed small hilar calcifications (2 cases). From the protection viewpoint, at equivalent entrance doses, .15-.26. Gy/cm2 of dose-area product (DAP) values were reported with the digital system, using a tension of 150 kV in orthogonal projections, which are considerably lower than .25-.70 Gy/cm2 measured with the conventional technique. Moreover, Thoravision permitted to perform up to 100 exposures/hour, using a phantom, and 15-20 digital chest examinations/hour, versus the average 12-15 with the conventional screen-film system. The initial results are very encouraging from the clinical and cost-effectiveness viewpoints, thanks to higher Thoravision productivity and to exam optimization, even though wider and prolonged experience plus a careful study of diagnostic accuracy, sensitivity and specificity in each group of chest conditions is advisable, to assess the real innovative impact of this digital chest imaging system.

Adolescent↗
PubMed1996

Palliative treatment of neoplastic strictures by self-expanding nitinol Strecker stent.

The purpose of this study was to evaluate technical and clinical results of self-expanding esophageal stent implanted in patients with malignant esophageal strictures and clinically significant dysphagia. From June 1992 to September 1994, 27 patients with inoperable tumors of the esophagus or gastric cardiac were treated by placement of 37 self-expanding nitinol stents. Water-soluble contrast and endoscopy studies were performed after the procedure and during the follow-up period. Successful stenting of the stricture was achieved in 27 patients. The mean dysphagia grade dropped from 2.3 to 1 (SD +/- 0.54) immediately after the procedure. After the insertion of the stent, 16 patients died in a period of time ranging from 0 to 13 months (mean 5.6 months), whereas at the end of the study 11 patients were alive 4-15 months after the procedure (mean 8.3 months). No major complications were observed. The results of this study are encouraging because esophageal stent placement was technically easy and clinically effective.

Adenocarcinoma↗
PubMed1996

Spontaneous spinal epidural hematomas: is the role of dural arteriovenous malformations underestimated?

Two recent observations of spinal epidural hematomas (SEH) are presented: one of them was associated with iatrogenic coagulopathy, the other, apparently "spontaneous", required reoperation for early recurrence and was finally attributed to ruptured epidural arteriovenous malformation missed during the first procedure. Both patients underwent complete recovery. Although modern neuroimaging provides quick, noninvasive, and sensitive assessment of spinal epidural bleeding, we believe that preoperative spinal angiography is indicated in "spontaneous" SEH with subacute clinical course. Demonstration of underlying vascular anomaly would allow better surgical planning, complete obliteration of abnormal vessels, and prevention of recurrences. Essential epidemiological, pathogenetical, and clinical aspects of SEH are reviewed.

Arteriovenous Malformations↗
PubMed1996

Overcoming imidazole resistance in Escherichia coli.

We have demonstrated that the high resistance to imidazoles in 60 Escherichia coli strains is overcome by lowering the minimum inhibitory concentration (MIC) in culture from > 3200 to < 0.39 micrograms ml(-1) and, by determining, in contact tests, the disappearance of 10(4) CFU with 25 micrograms ml(-1) of imidazoles after 3 min. Although the contact activity was not the same as growth inhibition due to the different target of the drug in the cell structures, we annulled E. coli imidazole resistance in cultural and direct tests by means of the same non-antimicrobial conditions related to outer membrane functions.

Cell Membrane Permeability↗
PubMed1996

[Invasive aspergillosis in the hematologic patient: the usefulness of computed tomographic and high-resolution computed tomographic studies].

Invasive aspergillosis is an emerging cause of death in hematologic patients. Several patterns of lung involvement are described: acute tracheobronchitis, bronchopneumonia, pleural aspergillosis and angioinvasive aspergillosis. The latter pattern is the most common one; it is characterized by different signs, some of which, supported by clinical data, are quite suggestive for fungal etiology. Particularly, nodules and/or wedge-shaped lesions with a ground-glass halo are a useful early feature, best detected by HRCT. Early therapy with amphotericin B may improve survival chances. Therefore, in neutropenia patients we decided, when possible, to perform high-resolution computed tomography (HRCT) as soon as fever appears. This was feasible in 8 of 32 patients with invasive aspergillosis examined with HRCT. Immediate treatment with amphotericin B in one such patient showing a nodule with the halo sign allowed the lesion to completely disappear. The authors describe the frequency of different radiologic signs in 32 patients, as observed in 54 HRCT exams; the results are compared with those obtained with conventional CT and chest X-ray. Compared to chest X-ray, CT detects more lesions and is more sensitive to small pneumothorax and minimal pleural effusion or thickening. HRCT is more suitable to detect initial cavitation and thin ground-glass haloes.

Aspergillosis↗
PubMed1996

[Bi- and tridimensional reconstruction with spiral computerized tomography in esophageal neoplasms. Preliminary clinical applications].

Spiral CT allows rapid data acquisition in an entire anatomical region during a single breath-hold and permits to obtain 2D and 3D reconstructions with good diagnostic accuracy. We investigated the capabilities of spiral CT reconstructions in demonstrating esophageal cancers. Spiral CT was performed in 10 patients with esophageal cancers and in 3 patients who underwent endoprostheses placement with surgical or interventional procedures. Bidimensional (MPR, CPR, MIP) and three-dimensional reconstructions with Shaded Surface Display (SSD) were obtained at the end of each exam. In the analysis of the results, CT reconstructions were compared with previous barium esophagography. Some of the main semiologic patterns were considered: tumor visualization, longitudinal extent of the neoplasm and its relationships with adjacent structures. MPRs were obtained in 9 patients and allowed to visualize the esophageal lumen with a filling defect, the neoplastic mass and its longitudinal and extraluminal extent. SSD reconstructions was obtained in 7 patients and allowed a good assessment of longitudinal neoplasm extent in 6 patients. Neoplastic mass visualization and extraluminal tumor extent were difficult to assess in all cases. MIP reconstructions were obtained in all patients and demonstrated longitudinal neoplasm extent with good accuracy. Neo-plastic tissue was visualized only indirectly through the filling defect of the esophageal lumen. MIP allowed to define, in 5 patients, the relationships of the neoplasms with adjacent vascular structures after the intravenous administration of contrast agent. In conclusion, we consider that Spiral CT reconstructions can be useful for a more accurate staging of esophageal cancers.

Esophageal Neoplasms↗
PubMed1995

Antifungal agents. 9. 3-Aryl-4-[alpha-(1H-imidazol-1-yl)arylmethyl]pyrroles: a new class of potent anti-Candida agents.

A new class of potent antifungal agents, namely, 3-aryl-4-[alpha-(1H-imidazol-1-yl)arylmethyl]-pyrroles, is described. These compounds are related to bifonazole and pyrrolnitrin, two compounds belonging to the class of antimycotic drugs. The synthesis of the title pyrroles has been performed starting from 1,3-diaryl-2-propen-1-ones, which were reacted with tosylmethyl isocyanide to give 3-aroyl-4-arylpyrroles. Reduction of the resulting compounds by lithium aluminum hydride furnished the related alcohols, which were treated with 1,1'-carbonyldimidazole to afford the required imidazole derivatives. Forty-four new pyrroles which incorporate an (arylmethyl)imidazole moiety in the 3-arylpyrrole structure were prepared by the above procedure and tested in vitro against Candida albicans and Candida spp. Among test compounds, 10 were found to be highly active against C. albicans. The most active derivative (27) was twice as potent (MIC90) as bifonazole, and its activity was 4 times greater than those of miconazole and ketoconazole. The other nine compounds showed antifungal activity of the same order of that of bifonazole and were ca. 2 times as active as miconazole and ketoconazole. Derivatives 21 and 27 tested in vivo against C. albicans A170 were shown to be highly effective in rabbit skin candidosis. Pharmacological studies on compounds 27 and other related pyrroles (19, 35, 36, 38, 39, and 49) are in progress to select one of them as a potential candidate for clinical experiments.

Adult↗
PubMed1995

Venous angiomas: plain and contrast-enhanced MRI and MR angiography.

We studied 17 patients with venous angiomas, 4 of whom had associated cavernous angiomas. All underwent MRI with spin-echo T1- and T2-weighted images and T1-weighted images after Gd-DTPA; MR angiography (MRA) was also performed with 3D and 2D time-of-flight technique; 5 patients underwent conventional angiography. Contrast-enhanced MRI demonstrated all the lesions, showing the peripheral medullary veins, the collector and the type of drainage. Both 3D and 2D MRA provided diagnostic information identical to that obtained after infusion of Gd-DTPA. Contrast-enhanced were T1-weighted images and MRA superior in all the cases to images without gadolinium. The possible association with cavernous angiomas (24% in our study) indicates T2-weighted imaging.

Adolescent↗