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Biomedical subjects

A Veltri

Publications and source records attributed to A Veltri.

At least 19 recordsLinked to original sources
PubMed2005

Effect of occlusal interference on habitual activity of human masseter.

It has been suggested that occlusal interference may increase habitual activity in the jaw muscles and may lead to temporomandibular disorders (TMD). We tested these hypotheses by means of a double-blind randomized crossover experiment carried out on 11 young healthy females. Strips of gold foil were glued either on a selected occlusal contact area (active interference) or on the vestibular surface of the same tooth (dummy interference) and left for 8 days each. Electromyographic masseter activity was recorded in the natural environment by portable recorders under interference-free, dummy-interference, and active-interference conditions. The active occlusal interference caused a significant reduction in the number of activity periods per hour and in their mean amplitude. The EMG activity did not change significantly during the dummy-interference condition. None of the subjects developed signs and/or symptoms of TMD throughout the whole study, and most of them adapted fairly well to the occlusal disturbance.

Adaptation, Physiological↗
PubMed2004

Electro-optic properties of switchable gratings made of polymer and nematic liquid-crystal slices.

We report the diffraction properties at wavelengths of 632.8 and 1550 nm for volume transmission gratings made of a sequence of continuously aligned nematic liquid-crystal layers separated by isotropic polymer slices. The gratings are generated by holographically curing a solution of liquid crystal diluted in an isotropic prepolymer by means of a laser beam at a wavelength of 352 nm with a total intensity of approximately 10 mW/cm2. A diffraction efficiency of 98% was measured, and an electric field as low as 5 V/microm switches off the phase grating. Measured angular spectra are fitted by use of the modified coupled-mode theory including the effects of grating birefringence.

Journal Article↗
PubMed2004

Dynamical behaviour of holographic gratings with a nematic film--Polymer slice sequence structure.

We have studied the dynamical response of a new kind of holographic grating to a pulsed electric field. The structure, named POLICRYPS, consists of a sequence of homogeneous polymer slices separated by liquid-crystal films. We have found that both the rise and fall response times depend on the pulse duration and amplitude of the applied electric field. We propose a phenomenological explanation for this behaviour, outlining the possibility of getting response times of the order of 100 micros by properly choosing the pulse shape. Results are very interesting for developments in which POLICRYPS gratings could be proposed as basic elements in photonic devices for telecom applications, and induce to a deeper analysis of the microscopic interaction between liquid crystal and polymer interfaces in these samples.

Journal Article↗
PubMed2000

Percutaneous treatment with amphotericin B of mycotic lung lesions from invasive aspergillosis: results in 10 immunocompromised patients.

The aim of this study was to evaluate the efficacy of percutaneous treatment of pulmonary lesions from invasive aspergillosis in immunocompromised patients. From 1992 to 1998, ten patients (seven men and three women; mean age 56 years) affected by hematological neoplasms (8 acute myeloid leukemias, 2 non-Hodgkin's lymphomas) and post-chemotherapy prolonged neutropenia developed pulmonary lesions from invasive aspergillosis. A total of 13 lesions (diameter 2-7 cm, median 5 cm) were treated percutaneously due to insufficiency of the high-dose i.v. therapy; under CT guidance, a median of 10 cm3 per session of a 1 mg/cm3 diluted solution of amphotericin B was injected through a fine needle (21-22 G); 45 sessions overall were performed (one to five per lesion, median four), according to the volume of the nodules, tolerance, and complications. The results were retrospectively evaluated either radiologically or clinically. Complications were cough, mild hemoptysis, and small pneumothorax and/or pleural effusion. No major complications occurred. One month after the beginning of treatment, 8 lesions completely resolved, 4 greatly improved, and 1 was not significantly reduced. In all ten patients symptoms improved (eight of ten could restart chemotherapy as scheduled). After antiblastic retreatment, 1 patient had mycotic recurrence. In our experience transthoracic topical treatment with amphotericin B of single or few lung lesions from invasive aspergillosis was effective, affording a rapid improvement of the lesions and symptoms, and allowing continuation of chemotherapy as scheduled, thereby reducing the risk of recurrences.

Amphotericin B↗
PubMed2000

[Computerized tomography in the study of thoracic-pulmonary complications after liver transplantation].

PURPOSE: To review the role of Computed Tomography (CT) in thoracic complications following orthotopic liver transplantation (OLT). MATERIAL AND METHODS: In a post-OLT population of 567 patients transplanted in our institution, 100 patients (17.6%) were examined with chest CT. We reviewed data relative to the total number of examinations, clinical and/or radiographic indications, the CT technique--i.e., conventional (with(out) intravenous, i.v., contrast material) or high-resolution (HRCT). We also reviewed the radiologic patterns and their correlation with the other clinical, bronchoscopic and/or laboratory results. RESULTS: Of 152 chest CT examinations, 45 (29.6%) were performed because of clinical indications, 31 (20.4%) because of a radiographic abnormality, 64 (42.1%) because of clinical and radiographic indications, while in 12 cases (7.9%) the reasons were unknown; 133/152 (87.5%) examinations had been performed with conventional CT scanning (100 with i.v. contrast agent and 33 without) and 19/152 (12.5%) with HRCT. Twenty of 152 (13.2%) examinations, in 16 patients, were normal; in the other 84 patients, 132/152 (86.8%) CT/HRCT studies showed 247 pathological findings (99 pleural effusions, 3 pericardial effusions, 62 cases of atelectasis, 1 pulmonary calcification, 70 suspected inflammatory parenchymal consolidations, 64 of them alveolar and 6 interstitial, 4 cases of interstitial edema and finally 8 neoplastic infiltrates). DISCUSSION: Correlated with clinical data, CT findings are very useful in detailing clinical-radiographic screening findings, despite the limitations in typifying pleural effusions, in differentiating atelectases from inflammatory parenchymal consolidations and in assessing pneumonia etiology. Also, despite its high sensitivity (94.1%) and specificity (92.8%), CT was not accurate enough in the differential diagnosis of pneumonia. History data were necessary to characterize the histology of neoplastic infiltrates. CONCLUSIONS: Chest CT has relatively uncommon, and sometimes only clinical, indications in post-OLT patients. The technique is chosen based on clinical-radiographic findings. CT proved useful in showing negative cases and in detailing clinical and radiographic findings but must be integrated with clinical findings to define inflammatory and neoplastic conditions.

Adult↗
PubMed1996

Recurrent necroinflammatory disease of multiple organs and colon. Systemic presentation of inflammatory bowel disease or gut involvement during systemic disorder.

A 30-year-old man with a recurrent febrile illness resembling infection is described. Because he presented with an acute abdomen, he underwent a laparotomy, which showed the paraaortic and mesenteric lymph nodes to be changed into an abscess-like granulomatous tissue made up of necrotized granulocytes. During further flare-ups, the disease affected the spleen, skin, colon, peripheral nerve, and muscle. Histology on the biopsy materials of both the skin and colon, and on the surgically removed spleen showed the same invading pathologic tissue. Exhaustive investigation disclosed no pathogen, and the flare-ups responded repeatedly to high-dose steroids. This patient's picture has recently been defined as a syndrome of chronic granulomatosis based on several published cases. As a distinctive feature, in our patient the granulomas affected also the colon. For the present, and for another previously described similar case we analyzed the factors that might permit the differential diagnosis between the above-mentioned granulomatous syndrome and Crohn's colitis.

Adult↗
PubMed1996

Transaxillary access to perform hepatic artery infusion (HAI) for secondary or primitive hepatic tumors.

There is a renewed interest in locoregional chemotherapy for hepatic tumors; trials in progress are experimenting with new therapeutic protocols with an approach combining different systems of infusion (HAI and systematic) or with the use of HAI as adjuvant or neoadjuvant of the surgical treatment or cryosurgical treatment of the hepatic metastases from colo-rectal cancer. However, HAI is practicable principally with the implantation of a catheter in the hepatic artery (port of Infusaid) by laparotomic access. This intervention limits wide-scale use of the infusion method, traditionally less toxic and more efficient in terms of results than systemic treatment. Limited experience of percutaneous access for HAI required more catheterisation with repeated puncturing of the artery and later necessity of surgery in cases of HAI with continuous spraying. Motivated by the first experience of certain authors from Chiba University, we have devised a system of catheterisation of the hepatic artery with transcutaneous access, with subcutaneous port that allows the use of HAI without recourse to the usual intervention. Access is made through the left axillary artery; the positioning of the catheter is in the hepatic artery with possible embolization of the collateral or abnormal hepatic artery that could hamper complete diffusion of the drug to the liver, or increase to toxicity of the method. The implantation is done in day-surgery. In the cases performed up to now there have been no complications regarding the method and the catheters function all perfectly thanks to the collaboration of ematologists to avoid possible thrombosis of the catheters.

Aged↗
PubMed1995

[Therapy of malignant hepatic tumors using percutaneous hot saline injections. Feasibility study and preliminary results].

PURPOSE: To investigate the feasibility and the results of percutaneous hot saline injection therapy (PSIT) of liver tumors. MATERIAL AND METHODS: Eight patients with hepatocellular carcinoma (11 nodules), 1 with cholangiocarcinoma and 1 with a metastasis from colon cancer underwent PSIT. The patients were selected according to variable criteria; thus, each patient was considered apart. A boiling saline solution was injected into the hepatic lesions through a needle like those commonly used for percutaneous ethanol injection (PEI). The results were assessed with US, CT, angiography, the measurement of tumor marker levels, the histopathologic examination of needle biopsy material, resected specimens, explanted liver material and follow-up. RESULTS: PSIT was more easily performed and altogether better accepted than PEI; in particular, pain immediately regressed upon infusion interruption. For this reason and for the atoxicity of the injected liquid, relatively large lesions could be treated with a greater volume per session and fewer sessions than with PEI. Treatment outcome was positive in all patients, except for the cholangiocarcinoma patient who required surgery. The only major complication was moderate peritoneal bleeding in a patient with severe coagulopathy. CONCLUSION: PSIT can be considered a useful tool for the local treatment of hepatic tumors. Its systematic use to treat hepatocellular carcinoma must be proceeded by further comparative studies with PEI.

Aged↗
PubMed1994

[Intrahepatic portosystemic shunts].

We want to present our experience performed at the Institute of Radiology of Turin: 98 TIPS in 97 patients (in 1 patient, twice). METHODS. From March 1992, 97 cirrhotic patients (18 Child A, 48 Child B, 31 Child C) underwent the TIPS procedure for portal hypertension. The indications were digestive hemorrhage in 81 patients (20 of which performed in emergency for acute bleeding), intractable ascites in 13 patients and bleeding prevention in 3 patients. RESULTS. Immediate technical success was obtained in 95/98 cases (96.9%). Patients were monitored by US-Doppler at 24 hours, 2 months and every 6 months and by esophagogastroscopy at 2 and 6 months. Major clinical complications included CID (2 cases), hepatic failure (3 cases), renal insufficiency (2 cases), heart failure (1 case), recurrent bleeding (6 cases) and encephalopathy (15 cases). We had 5 early occlusion and 17 late stenosis of the shunt; 21 patients in this group were successfully treated either by PTA or restenting; one patient underwent a surgical shunt. Mortality rate follow-up was 0/17 among Child A patients, 7/48 (14.5%) among Child B patients and 12/29 (41.3%) among Child C patients. CONCLUSIONS. TIPS is a safe and valuable method for the treatment of portal hypertension. Though shunt stenosis may occur with a certain frequency (22/95, 23.1% in our study), a second intervention is usually effective in reducing gastro-oesophageal varices and ascites.

Adult↗
PubMed1994

[Transjugular intrahepatic portasystemic shunt (TIPS). Role of ultrasonographic methods].

The transjugular intrahepatic portosystemic shunt (TIPS) is a new interventional radiology procedure which may be assisted by modern ultrasound techniques (US). Color-Doppler US can be used for patients selection, during TIPS and in the follow-up. In a 20-month period, 71 patients were examined: 3 of them were excluded because of the absolute contraindications shown by US; in 14 of the remaining 68 patients, US demonstrated relative contraindications, such as hepatocellular carcinoma, partial portal vein thrombosis and right internal jugular vein occlusion. During the maneuver, US helped to select the most adequate veins for shunt creation and was especially useful in guiding portal vein puncture, thus allowing technical success to be achieved in 65/68 patients. The mean number of passes per patient was 2.7 and no procedure-related complications were observed. US was also used to investigate TIPS patency the day after the maneuver and to monitor shunt function during the follow-up. Color-Doppler US correctly diagnosed both 3/65 early occlusions and 9/65 late stenoses; in particular, in 18/65 patients US showed gradual flow reduction through TIPS, but clinical and endoscopic findings of malfunction appeared only in 9/65 patients whose mean reduction rates exceeded 50% at Doppler US.

Adult↗
PubMed1993

[Ultrasonography-guided alcohol injection in simple renal cysts. Long-term results].

The percutaneous treatment of simple renal cysts must be restricted to symptomatic lesions. It consists in a guided puncture, fluid aspiration and the injection of a sclerosing agent. The authors describe the procedure they followed, which has been made possible by technical progress. It consists in US guidance, a Trocar catheter drainage set and the injection of absolute alcohol. Moreover, the long-term results are reported of a retrospective study of 69/148 treated patients who underwent one or more US exams 15 days to 5 years after the procedure. Eleven of 69 patients (15.9%) exhibited complete regression, 42 of 69 (60.9%) had lesion relapse < 5 cm phi and 16 of 69 (23.2%) had > 5 cm relapse. On the whole, 53 (76.8%) positive results were obtained after the first treatment; positive results were obtained after the second treatment in 4 of 16 patients with > 5 cm relapse. US follow-up showed changes in the sizes of the relapsed cysts, which sometimes shrunk in the long run. All treated cysts reduced in volume; nevertheless, it would be useful to look for new sclerosing agents allowing a higher rate of complete regressions.

Adult↗
PubMed1992

[Liver transplantation: diagnostic imaging in the preoperative assessment].

The correct selection of patients for liver transplantation, which is essential for surgical success, requires thorough radiological evaluation. The authors present their experience on 94 pretransplant adult patients that underwent a total of 251 diagnostic exams (Doppler US, CT, angiography and cholangiography) and interventional radiology maneuvers (biopsy, chemoembolization, biliary drainage). Three sclerosing cholangitis, 3 Budd-Chiari syndromes and 20 hepatocellular carcinomas in cirrhotic patients were identified; venous collaterals were present in 62.7% of the cases, 12.8%, of which had important spontaneous porto-systemic shunts; 6 patients had portal thrombosis; 20 arterial variations were found. Interventional maneuvers were useful and free of complications. US, CT and angiographic findings of each patient were compared. Integrating informations from different exams allowed a significant increase in the accuracy of diagnostic conclusions. Thanks to interventional maneuvers 5 patients could be selected for transplantation (hepatic arterial lipiodolization stopped the growth of 4 hepatic neoplasms; 2 infected fluid collections were sterilized by percutaneous US-guided drainage and topic therapy.

Adult↗
PubMed1992

[Liver transplantation: role of the radiologic methods in the postoperative period].

Some complications of liver transplantation appear as aspecific clinical and blood test abnormalities; others--e.g., hepatic artery thrombosis in the immediate postoperative period and stenosis of the biliary anastomosis before T-tube removal--require early diagnosis. These considerations justify the need of frequent radiologic examination in both the complicated course and the follow-up. The authors report their experience in 59 adult patients submitted to liver transplantation for irreversible liver disease in advanced stage (49 with cirrhosis, 10 with HCC; 5 with cholestatic hepatopathy; 3 with fulminant hepatitis; 1 with Budd-Chiari syndrome; 1 with metastatic APUDoma). Two hundred and sixty-three radiological examinations were performed (Doppler US, CT, angiography and cholangiography) which showed numerous early and delayed complications: 13 of them were treated with interventional radiology maneuvers (US-or CT-guided percutaneous drainage of fluid collections, biliary drainage, bilioplasty, arterial transcatheter embolization). Our results demonstrate that diagnostic and operative radiology are essential for the success of liver transplantation; integrated imaging is particularly important in the diagnosis of complications, while interventional radiology techniques can be usefully employed in their treatment.

Adult↗
PubMed1992

[Percutaneous transjugular intrahepatic portosystemic shunt (TIPS). The preliminary experience and proposal of a new method].

A new interventional procedure employing metallic stents has been recently suggested to perform percutaneous portosystemic shunts in the treatment of variceal bleeding in portal hypertension; the technique is called TIPSS (transjugular intrahepatic portosystemic stent shunt). This percutaneous treatment presents several advantages over surgery: the shunt diameter can be calibrated according to the degree of portal hypertension; moreover, TIPSS can be performed in patients waiting for liver transplantation because it does not alter the vascular anatomy of liver. The original technique employed transhepatic portography. In this paper the authors report on their personal experience and present their series of 4 patients with portal hypertension and variceal bleeding, in whom TIPSS was performed utilizing noninvasive US guidance. Variceal bleeding was successfully treated in all patients and variceal distension was also obtained.

Adult↗
PubMed1992

[Role of ultrasonography in the assessment of lymphoma localized in the abdomen].

Both prognosis and treatment of lymphomas depend strictly on both clinical staging and histologic classification. The role of US was investigated in the evaluation of patients affected with abdominal lymphoma. To this purpose, 52 patients affected with abdominal lymphoma underwent US and CT studies during staging, treatment, or follow-up. A comparison of the results of the two methods shows that the systematic use of US allows 5% of lymph nodes missed at CT to be demonstrated, together with hepatic and splenic involvement also undetected by CT. It is true, however, that the limited number of cases does not allow this result to be correlated with the histopathologic type of lymphopathy. US has also been the examination of choice to evaluate response to chemotherapy and to study suspected relapses. In the authors' opinion, US should become a complementary technique to CT in the staging of abdominal lymphomas.

Abdominal Neoplasms↗