Radiomics in pancreatic neuroendocrine tumors: methodological issues and clinical significance.

PURPOSE: To present the state-of-art of radiomics in the context of pancreatic neuroendocrine tumors (PanNETs), with a focus on the methodological and technical approaches used, to support the search of guidelines for optimal applications. Furthermore, an up-to-date overview of the current clinical applications of radiomics in the field of PanNETs is provided. METHODS: Original articles were searched on PubMed and Science Direct with specific keywords. Evaluations of the selected studies have been focused mainly on (i) the general radiomic workflow and the assessment of radiomic features robustness/reproducibility, as well as on the major clinical applications and investigations accomplished so far with radiomics in the field of PanNETs: (ii) grade prediction, (iii) differential diagnosis from other neoplasms, (iv) assessment of tumor behavior and aggressiveness, and (v) treatment response prediction. RESULTS: Thirty-one articles involving PanNETs radiomic-related objectives were selected. In regard to the grade differentiation task, yielded AUCs are currently in the range of 0.7-0.9. For differential diagnosis, the majority of studies are still focused on the preliminary identification of discriminative radiomic features. Limited information is known on the prediction of tumors aggressiveness and of treatment response. CONCLUSIONS: Radiomics is recently expanding in the setting of PanNETs. From the analysis of the published data, it is emerging how, prior to clinical application, further validations are necessary and methodological implementations require optimization. Nevertheless, this new discipline might have the potential in assisting the current urgent need of improving the management strategies in PanNETs patients.

Measurements and evaluation of the risks due to external radiation exposures and to intake of activated elements for operational staff engaged in the maintenance of medical cyclotrons.

The aim of this paper is to assess the activation phenomena and to evaluate the risk of external exposure and intake doses for the maintenance staff of two medical cyclotrons. Two self-shielded cyclotrons are currently operating in the facility for the routine production of (11)C and (18)F. Four radiochemistry laboratories are linked to the cyclotrons by means of shielded radioisotope delivery lines. Radiopharmaceuticals are prepared both for the PET Diagnostic Department, where four CT-PET scanners are operating with a mean patient workload of 40 d(-1) and for [(18)F]FDG external distribution, to provide radiopharmaceuticals for other institutions. In spite of the fact that air contamination inside the radiochemistry laboratories during the synthesis represents the largest 'slice of the pie' in the evaluation of annual intake dose, potential contamination due to the activated particulate, generated during cyclotron irradiation by micro-corrosion of targets and other components potentially struck by the proton beam and generated neutrons, should be considered. In this regard, the most plausible long-lived (T(1/2) > 30 d) radioisotopes formed are: (97)Tc, (56)Co, (57)Co, (58)Co, (60)Co, (49)V, (55)Fe, (109)Cd, (65)Zn and (22)Na. The results for the operating personnel survey has revealed only low-level contamination for (65)Zn in one test, together with minor (18)F intake, probably due to the environmental dispersion of the radioisotope during the [(18)F]FDG synthesis.

Noradrenaline use is not associated with extubation failure in septic patients.

Standard clinical practice recommends minimal doses of vasoactive drugs during weaning of patients from mechanical ventilation. However there are currently no clinical data to inform clinicians about whether the use of noradrenaline during weaning predisposes to weaning failure. The objective of this study was to evaluate whether the necessity of the vasopressor noradrenaline in mechanically ventilated patients recovering from septic shock changed the extubation outcome. A total of 656 patients recovering from septic shock on mechanical ventilation were selected from intensive care units in two university hospitals. Patients receiving noradrenaline at the time of weaning and case-controls not taking noradrenaline were matched for age, gender, haemodynamic and ventilatory parameters, aetiology of respiratory failure and APACHE II score. One hundred and forty-five patients who successfully tolerated a spontaneous breathing trial were extubated while on noradrenaline therapy and the reintubation rate was measured. In the noradrenaline group, the mean dose of noradrenaline during initial shock treatment was 0.52+/-0.29 microg/kg/min and 0.12+/-0.10 microg/kg/min during weaning. The reintubation rate was 12/63 (19%) in the noradrenaline group and 15/82 (18.3%) in the control group (P=1.00). Intensive care unit mortality was also similar in both groups (10/63, 15.9%) for noradrenaline patients and (11/82, 13.4%) for control patients (P=0.81). Arterial blood gases and ventilatory and haemodynamic parameters were similar in all patients regardless of weaning success. We did not find that the use of noradrenaline at the time of weaning was associated with extubation failure. Low doses of noradrenaline may not preclude weaning from mechanical ventilation.

In vitro candidacidal activity of a synthetic killer decapeptide (KP) against Candida albicans cells adhered to resin acrylic discs.

BACKGROUND: Oral Candida spp., and C. albicans in particular, are considered as important aetiological agents in the pathogenesis of denture-induced stomatitis. Several studies have reported that C. albicans is able to easily adhere to different medical devices, such as vascular and urinary catheters or acrylic denture surfaces, and that adhesion is a fundamental step in the initial pathogenic process of colonization and further possible infection. Recently, a synthetic decapeptide (KP) derived from the sequence of a single-chain recombinant anti-idiotypic antibody, acting as a functional internal image of a microbicidal, broad spectrum yeast killer toxin, has been reported to kill in vitro C. albicans cells and to exert a therapeutic activity against experimental mucosal and systemic candidiasis. METHODS: The aim of this study was to evaluate, through a CFU assay, the candidacidal activity of KP on sanded acrylic resin discs, previously colonized by C. albicans cells. RESULTS AND CONCLUSIONS: At 100 microg/ml KP showed over 90% of killing activity on C. albicans cells adhered to resin discs, when compared with a scramble peptide used as control. The results of this study suggest a potential effect of KP on C. albicans cells adhered on the surface of resin materials, such as prosthetic dentures.

Two-dimensional vs three-dimensional imaging in whole body oncologic PET/CT: a Discovery-STE phantom and patient study.

AIM: To evaluate the performance of the positron emission tomography (PET)/computed tomography (CT) Discovery-STE (D-STE) scanner for lesion detectability in two-dimensional (2D) and three-dimensional (3D) acquisition. METHODS: A NEMA 2001 Image-Quality phantom with 11 lesions (7-37 mm in diameter) filled with a solution of 18F (lesion/background concentration ratio: 4.4) was studied. 2D and 3D PET scans were sequentially acquired (10 min each) in list mode (LM). Each scan was unlisted into 4, 3 and 2-min scans. Ten [18F]FDG PET oncological patient studies were also evaluated. Each patient underwent a 3D PET/CT whole body scan, followed by a 2D PET scan (4 min LM) and a 3D PET scan (4 min LM) over a single field of view. Both 2D and 3D scans were unlisted in 3 and 2-min scans. Data were evaluated quantitatively by calculating quality measurements and qualitatively by two physicians who judged lesion detectability compared to statistical variations in background activity. RESULTS: Quantitative and qualitative evaluations showed the superiority of 3D over 2D across all measures of quality. In particular, lesion detectability was better in 3D than in 2D at equal scan times and 3D acquisition provided images comparable in quality to 2D in approximately half the time. Interobserver variability was lower in evaluation of 3D scans and lesion shape and volume were better depicted. CONCLUSION: In oncological applications, the D-STE system demonstrated good performance in 2D and 3D acquisition, while 3D exhibited better image quality, data accuracy and consistency of lesion detectability, resulting in shorter scan times and higher patient throughput.

Decommissioning procedures for an 11 MeV self-shielded medical cyclotron after 16 years of working time.

The present article describes the decommissioning of a compact, self-shielded, 11 MeV medical cyclotron. A Monte Carlo simulation of the possible nuclear reactions was performed in order to plan the decommissioning activities. In the course of the cyclotron dismantling, cyclotron components, shields, and floor concrete samples were measured. Residual activities were analyzed with a Ge(Li) detector and compared with simulation data. Doses to staff involved in the decommissioning procedure were monitored by individual TL dosimeters. The simulations identified five radioactive nuclides in shields and floor concrete: 55Fe and 45Ca (beta emitters, total specific activity: 2.29 x 10(4) Bq kg) and 152Eu, 154Eu, 60Co (gamma emitters, total specific activity: 1.62 x 10(3) Bq kg-1). Gamma-ray spectrometry confirmed the presence of gamma emitters, corresponding to a total specific activity of 3.40 x 10(2) Bq kg-1. The presence of the radioisotope 124Sb in the lead contained in the shield structure, corresponding to a simulated specific activity of 9.38 x 10(3) Bq kg-1, was experimentally confirmed. The measured dose from external exposure of the involved staff was <20 muSv, in accordance with the expected range of values between 10 and 20 muSv. The measured dose from intake was negligible. Finally, the decommissioning of the 11 MeV cyclotron does not represent a risk for the involved staff, but due to the presence of long-lived radioisotopes, the cyclotron components are to be treated as low level radioactive waste and stored in an authorized storage area.

Evaluation of the clinical performances of a large NaI(Tl) crystal 3D PET scanner.

AIM: This study was aimed at assessing the clinical performances of a NaI(Tl) crystal 3D PET scanner, C-PET (ADAC-UGM), using a multi-ring 2D BGO PET scanner (multi-ring PET), as a reference. METHODS: Thirty-seven oncological patients were studied in sequence with multi-ring PET and C-PET, within 30 days of a CT study. In order to assess the behaviour of C-PET in relation to acquisition count rate, patients were divided into 3 groups according to the count rate at the time of the C-PET scan acquisition. Group A (n=21): 3000-5000 kcounts/sec (recommended count rate range); Group B (n=8): <3000 Kcounts/sec and Group C (n=8): >5000 Kcounts/sec. RESULTS: The number of lesions detected by multi-ring PET and C-PET, classified according to size, was compared. For Group A and Group B there was a good agreement between C-PET and multi-ring PET in terms of lesion detectability (relative sensitivity: 99.9% and 96.0%, respectively), while for Group C the relative sensitivity of C-PET was 61.9%. CONCLUSION: Optimal performances of the C-PET scanner can thus be obtained at a count rate within or below the recommended range. Despite a lower lesion/background contrast resulting from a high scatter and random noise, the sensitivity of C-PET in detecting hypermetabolic lesions is comparable to that of multi-ring PET. These findings are discussed in relation to the physical performance of the two scanners and particularly in relation to the 3D vs 2D acquisition modality.

[Gorlin-Goltz syndrome]. / Sindrome di Gorlin-Goltz.

The Nevoid Basal Cell Carcinoma Syndrome (NBCCS) or Gorlin-Goltz syndrome, principally characterized by basal cell carcinomas, multiple jaw cysts and skeletal anomalies, is an interesting pathology for the dentist who is often the first clinician involved in the diagnosis of this syndrome. Because of the multisystem involvement and variable expressivity of NBCCS, patients affected by this syndrome must be evaluated by many medical and dental specialists in order to properly sequence their treatment.

Insulin receptor antibodies inhibit insulin uptake by the liver: in vivo 123I-insulin scintigraphic scanning and in vitro characterization in autoimmune hypoglycemia.

BACKGROUND: Insulin receptor antibodies can induce severe hypoglycemia or insulin resistance in rare autoimmune syndromes. In vitro properties of these antibodies occasionally explain the clinical features of the syndrome, but direct evidence of their in vivo activity is poor. We studied a 58-year-old male with rheumatoid arthritis who presented with hypoglycemic coma. METHODS AND RESULTS: Antibodies were detected by inhibition of 125I-insulin binding to human insulin receptor-3T3 cells by the patient's serum. By immunofluorescence, they were immunoglobulin G of all four subclasses, immunoprecipitated insulin receptors from biotin-labeled cells, and triggered phosphorylation of the beta subunit of the insulin receptor. Insulin binding on the patient's red blood cells was markedly reduced. A biodistribution study after intravenous 123I-Tyr A14 insulin showed a marked inhibition of tracer uptake by the liver, reaching 10% of the injected dose (controls, mean +/- SD, 21.1 +/- 1.7%; n = 10). Time activity curves generated on the liver and on the heart were parallel, with a T1/2 of 11.5 minutes for both, suggesting that no specific uptake occurred in the liver, where tracer activity represented only the blood pool. Clearance of insulin from the blood was indeed slower than in controls and mainly occurred through the kidneys. Analysis of plasma 123I-insulin immunoreactivity and trichloroacetic acid precipitate showed that insulin degradation did not occur as in normal controls. CONCLUSIONS: In this patient with hypoglycemic syndrome, insulin receptor antibodies with in vitro insulin-like activity are capable of blocking in vivo the access of insulin to the liver receptor compartment, as directly demonstrated by the markedly altered biodistribution of intravenously injected 123I-insulin.

[Neoplastic transformation of oral lichen planus. I: Review of the literature]. / La cancerizzazione del lichen planus orale. I: Revisione della letteratura.

Lichen planus is described like a well-characterized dermatological condition affecting the skin and the oral and genital mucosa. Over the years, different authors have expressed the possible oral lichen planus premalignant nature, but this is still controversial. This criticism is due to the insufficiency of the clinical and histopathological data to support the initial diagnosis of oral lichen planus, the occurrence of some wrong diagnostic criteria for this pathology, the contemporary presence in the same region of the oral lichen planus lesions and of neoplasia. The malignant transformation of oral lichen planus rate varies, according to authors, from 0.4 to 3.7%. The aim of this study is to review the literature from 1910 to 1999, focusing on the suggested possible premalignant nature of oral lichen planus.

[Neoplastic transformation of oral lichen planus. II: association with risk co-factors]. / La cancerizzazione del lichen planus orale. II: Associazione con co-fattori di rischio.

The possible malignant transformation of oral lichen planus is still controversial. It is not clear if this is in fact due to the premalignant nature of oral lichen planus or to the presence of some risk-factors in patients with this pathology. The risk co-factors that may he involved in this malignant transformation are numerous. Some authors suggested a correlation between oral lichen planus and HCV or HGV, or with the presence of some oncogenic viruses (EBV, HSV, HPV). Cases of this malignant transformation on oral and genital mucosa with lichen are reported, hut none on the skin lesions. The aim of this study is to investigate, through the literature, these correlations that may have a role in the malignant transformation of oral lichen planus.

[Burning mouth syndrome. Clinical experience with 75 patients]. / Burning mouth syndrome. Esperienza clinica in 75 pazienti.

The burning mouth syndrome (BMS) is a very common disorder frequently seen in practical dentistry. It is a particular condition with a complex of strange burning sensation localized in the oral mucosa which is clinically normal. It is very important for the dentist to recognize and classify this particular syndrome in order to exclude other factors which can cause the same symptoms. On the basis of personal experience on 75 patients, the complex management of this particular group of patients has been evaluated to make a right diagnosis and a correct treatment.

[Correction measured by attenuation in tomographic heart studies with single photon emission with thallium 201. Comparison with positron- emission tomographic studies with ammonium marked with nitrogen]. / Correzione misurata per l'attenuazione negli studi cardiaci tomografici con emissione di fotone singolo con tallio 201. Confronto con studi tomografici con emissione di positroni con ammoniaca marcata con azoto 13.

PURPOSE: We investigated 201Tl myocardial uptake with(out) nonuniform attenuation compensation in ischemic myocardiopathy patients. The segmental patterns of the two types of SPECT images were compared with PET [13N]NH3 studies performed in the same patient. PET images were taken as reference and the diagnostic accuracy of SPECT with(out) attenuation correction was evaluated. MATERIAL AND METHODS: During the SPECT study transmission and emission data were simultaneously recorded by a triple head gamma camera equipped with fan beam collimators and a 99mTc transmission line source (740MBq). SPECT and PET images, the former reconstructed with(out) attenuation correction, were corecorded and reoriented along the short axis. The left ventricular wall was divided into 11 segments and segmental activity normalized to maximum in each study. RESULTS: Statistically significant differences were found between PET/(un)corrected SPECT ratios in posterior and septal segments. In these myocardial regions, attenuation correction compensates for attenuation artifacts, by correcting the underestimation of radioactivity concentration caused by radiation absorption. A statistically significant difference was also found in midventricular anterior and apical segments (p < .05). However, in these regions attenuation correction results in a decrease in corrected relative to uncorrected SPECT activity. The agreement rate with PET data is higher for corrected SPECT (mean differences were 3.12 +/- 11.51 and 2.19 +/- 8.63 for uncorrected versus corrected SPET). We had 50% positive and 77% negative predictive value without attenuation correction, versus up to 69% and 90%, respectively, with attenuation correction. CONCLUSIONS: The attenuation correction procedure with simultaneous transmission-emission effectively reduces attenuation artifacts in SPECT myocardial imaging. While diagnostic accuracy increases in posterior and septal myocardial regions, anterior and apical data need careful interpretation because a relative decrease in radioactivity concentration can be observed after attenuation correction.

Lack of prognostic value of 99mTc MIBI rest, 18F FDG and 201TL rest/redistribution on PTCA outcome of patients with moderate left ventricle dysfunction.

BACKGROUND: The clinical work-out of patients undergoing coronary revascularization includes the assessment of myocardial viability. This approach has to be defined in the different classes of patients. The aim of this study was to evaluate the predictive prognostic value of different techniques on outcome following PTCA in patients with moderate left ventricle dysfunction (left ventricle EF > or = 40%). METHODS: Seventeen patients with EF > or = 40% and undergoing PTCA were studied by 201Tl rest/redistribution, 18F-FDG and 99mTc-MIBI rest. Regional kinesis was scored by echo, dividing left ventricle in 11 segments. The echo evaluation was repeated at 1 and 6 months after revascularization. RESULTS: Global EF was 52.5 +/- 7% and 69 segments had abnormal kinesis. Patients underwent stress/rest 99mTc-MIBI SPET, rest/redistribution 201Tl SPET and rest 18F-FDG PET. Among the 11 segments defined on echo-matched tomographic images, the one with the highest activity at stress was assumed as reference (activity = 100%). If > 50% of reference segment, 18F-FDG and 201Tl uptakes were considered significant. After PTCA, the echo-follow-up did not demonstrated significant improvement of left ventricle function at 30 days after PTCA (EF 56 +/- 6%) as well as at 6 months (EF 56 +/- 9%). The positive predictive value under these conditions resulted: 46.5% with 99mTc-MIBI rest, 47.4% with 201Tl rest-redistribution and 45.7% with 18F-FDG. CONCLUSIONS: In summary, in the class of patients with moderately compromised function, considering as reference the improved regional kinesis after PTCA, 99mTc-MIBI at rest, 201Tl rest/redistribution and 18F-FDG do not exhibit a clear predictive value; patient population is then a highly relevant point to establish the accuracy of these diagnostic procedures.

Comparison of dual-head coincidence PET versus ring PET in tumor patients.

UNLABELLED: This study compared the multiring detector (Ring-PET) and the dual-head coincidence imaging system (DH-PET) for staging/ restaging neoplastic patients before or after surgery or radiochemotherapy. METHODS: Seventy patients with suspected tumor recurrence or metastatic dissemination received an intravenous dose of 18F-fluorodeoxyglucose (FDG) under overnight fasting and were studied in sequence with a dedicated positron emission tomograph with Ring-PET and a DH-PET. Ring-PET studies were performed 45-75 min postinjection and were followed by a DH-PET scan approximately 3 h postinjection. Number and location of the hypermetabolic lesions detected on DH-PET and Ring-PET reconstructed images were blindly assessed by three independent observers. RESULTS: DH-PET identified all 14 head lesions detected by Ring-PET, 53 of 63 thoracic lesions and 36 of 45 abdominal lesions. Of the 19 lesions not identified by DH-PET, 6 were smaller than 10 mm, 8 were between 10 and 15 mm and 1 was 18 mm; dimensions of 4 bone lesions were not available. A concordant restaging, based on location and number of lesions detected, was found in all 14 patients with head tumors, in 28 of 30 patients with thoracic tumors and in 24 of 26 patients with abdominal tumors. CONCLUSION: We found a good agreement between Ring-PET and DH-PET assessment of oncologic patients in detecting hypermetabolic lesions > or = 10-15 mm.

[Integration of computerized tomography imaging with single photon emission in a commercial system for developing radiotherapy fields: application to conformational irradiation for lung carcinoma]. / Integrazione delle immagini della Tomografia Computerizzata con emissione di fotone singolo in un sistema commerciale per l'elaborazione dei piani di radioterapia: applicazione all'irradiazione conformazionale del carcinoma polmonare.

PURPOSE: Single photon emission computed tomography (SPECT) of lung perfusion permits to map functioning lung parenchyma with higher sensitivity than CT. Delivering higher radiation doses is used to increase local control in lung carcinoma; this strategy is based on radiobiological and clinical studies. Lung parenchyma is a dose-limiting tissue in patients irradiated for lung cancer. Functional mapping based on SPECT and CT findings permits to design radiation beams such as to minimize irradiation of functioning lung. MATERIAL AND METHODS: CT and SPECT were used to examine a patient with non small cell lung carcinoma (stage IIIB, T4N0, left lung) candidate to conformal irradiation. Images were spatially correlated based on lung contours and using CT findings as reference. SPECT images were normalized to mean right lung value and expressed as perfusion (functional) contours. CT images and perfusion contours were transferred to the treatment planning system (Cadplan V 2.79, Varian-Dosetek Oy): in this way both functional (SPECT) and anatomical (CT) data were available for planning. A comparison was made between two irradiation techniques defined at TPS with (technique B) or without (technique A) SPECT contour information. The prescribed dose was 70.2 Gy. Rival plans were compared using dose volume histograms of target and risk organs. Both functional and anatomical regions were considered in the lung, together with single lung(s) and lung parenchyma. A second perfusion SPECT was obtained 5 months after irradiation and correlated with pretreatment CT images. RESULTS: SPECT lung scans showed marked heterogeneity in the left lung, which was found neither at CT nor at classic lung function tests. The lung volume with perfusion exceeding 80% of average corresponds to about 70% of the anatomical volume. Mean doses to anatomical and to functional lung parenchyma were 24 Gy and 19 Gy, respectively, with technique A and 23 Gy and 18 Gy, respectively, with technique B. Thirty-five percent and 20%, respectively of anatomical and functional lung parenchyma received > or = 25 Gy (V25) with technique B. The figure for functional lung parenchyma was reduced by 5% with technique B. Optimal design of irradiation field geometry decreased the area of functional parenchyma given high doses, which sparing was greater with smaller irradiation volumes. CONCLUSIONS: We have integrated the functional data provided by SPECT lung perfusion into a commercial irradiation planning system. Lung function mapping permits to design irradiation portals sparing larger areas of functional lung parenchyma.

[The effects of drugs on the oral cavity]. / Effetti delle droghe sul cavo orale.

As shown by the growing numbers of users attending the public drug addiction services, drug abuse is a phenomenon that is constantly spreading. It is important that dentists are aware of the oral problems linked to drug abuse. This study examines the general effects and oral implications of the illegal substances used by the majority of drug addicts. The main dental complications of cannabinoids are the increased incidence of squamous cell carcinomas of the oral cavity, the presence of xerostomia and severe gingivitis. Depending on how it is taken, cocaine may cause ischemic necrosis of the palate, inflammation, ulceration and gingival retraction, as well as an increased incidence of bruxism. Hallucinogens have few direct oral effects, but among these it is worth recalling xerostomia, increased bruxism and oral problems linked to malnutrition caused by ecstasy. Turning to the opioids, heroin is the drug primarily used by the majority of drug addicts. Its oral effects mainly take the form of dental decay, showing a particular form and extent linked either directly or indirectly to heroin use. This results in "typical" or "atypical" caries pathologies directly linked to the effects of heroin. Given the extent of this phenomenon, it is important that dentists are aware of the problems linked to drug abuse that they may have to treat.

Imaging of the buffering effect of insulin antibodies in the autoimmune hypoglycemic syndrome.

Insulin autoimmune hypoglycemia is characterized by recurrent hypoglycemia and high levels of immunoreactive insulin in the presence of insulin autoantibodies. The mechanisms inducing hypoglycemia are largely unknown. An [123I]insulin scintigraphic scanning was performed to directly demonstrate the effect of antibodies on insulin biodistribution in one patient with this syndrome both before and after treatment. The patient had insulin autoantibodies IgG3 lambda, which had a single site dissociation constant (Kd = 10(-7) mol/L, by Scatchard analysis), a very fast dissociation rate of immune complexes, and a very rapid association of [125I]insulin. Insulin receptors on red blood cells were down-regulated. The [123I]insulin scintigraphic study imaged the buffering effect of antibodies on insulin bioavailability. [123I]Insulin was not removed from the blood, and no liver or kidney uptake of the hormone occurred. The frequency and severity of hypoglycemic episodes required treatment. Insulin antibody levels decreased and [123I]insulin biodistribution improved after treatment with plasmapheresis and prednisone. Improved hormone bioavailability was further evidenced by the reduction in the hypoglycemic delay after i.v. insulin from 90 min before any treatment to 60 min after plasmapheresis and 30 min after steroid administration. Glucose tolerance was normal after treatment. Plasmapheresis followed by steroid treatment can lower the insulin antibody concentration, abolish severe hypoglycemia, and improve insulin biodistribution and glucose tolerance in insulin autoimmune hypoglycemia.

Correlation of SPECT and PET cardiac images by a surface matching registration technique.

Complementary information provided by Single Photon and Positron Emission Tomography (SPECT and PET) in nuclear cardiology allows a better comprehension of the physiopathology of the heart. In this work a surface matching registration technique is evaluated in the spatial correlation of SPECT and PET cardiac images. The method is based on matching correspondent anatomical surfaces extracted from transmission (TR) SPECT and PET studies, usually performed for attenuation correction. The accuracy of the technique was evaluated by phantom experiments and on patient data (201Tl SPECT and 13NH3 PET perfusion studies). An application of the method is presented for the correlation of SPECT 201Tl perfusion and PET 18FDG metabolic studies in the evaluation of myocardial viability.

Acetylcysteine therapy for chronic hepatitis C: are its effects synergistic with interferon alpha? A pilot study.

OBJECTIVE: This trial reports the 6-month results of a pilot study using lymphoblastoid interferon alpha (IFNalpha) and acetylcysteine (N-acetylcysteine) separately and in combination in patients with chronic hepatitis C, genotype 1b, who were nonresponders to previous treatment with recombinant IFNalpha alone. PATIENTS AND METHODS: 21 patients were randomly divided into three groups of seven each. Group A was treated with lymphoblastoid IFNalpha 6MU three times a week for 6 months; group B received the same schedule of lymphoblastoid IFNalpha as group A plus acetylcysteine 1200 mg/day per os in two administrations, and group C received only acetylcysteine 1200 mg/day per os in two administrations. RESULTS: Mean serum alanine aminotransferase (ALT) levels at 6 months in groups A and B, but not in group C, were significantly lower than baseline values (p < 0.05 and p < 0.03, respectively). Two patients in group A (28.6%) and three in group B (42.9%), but none in group C, had normalised ALT levels at 6 months. During follow-up, levels flared in one group A and in one group B patient. Thus, at the end of follow-up one group A and two group B patients were sustained responders. At the end of therapy and follow-up, hepatitis C virus (HCV)-RNA was negative in one patient in group A and two patients in group B. As no serious adverse effects were observed, therapy was never interrupted or suspended. CONCLUSION: Acetylcysteine alone had no effect on hepatic cytolysis and viral replication; lymphoblastoid IFNalpha showed a modest, but better, response than recombinant IFNalpha, and the combination therapy, although in a limited number of patients, appeared to be more efficient than lymphoblastoid IFNalpha alone.