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Biomedical subjects

P Princi

Publications and source records attributed to P Princi.

51 records · Page 3Linked to original sources
PubMedDate not supplied

Effect of injections of contrast media on regional uptake of (14C)-2-deoxyglucose by the rat brain.

Mechanisms contributing to the rare but consistent neurotoxicity of contrast media currently in clinical use for the radiological examination of the subarachnoid space remain to be isolated. We assessed, by means of the (14C)-2-deoxy-D-glucose (2-DG) autoradiographic method, the effect of three non-ionic, low-osmolar contrast media, namely metrizamide, iopamidol and iohexol, on the local cerebral glucose utilization in the rat brain after intracisternal application. A significant (-30%) global reduction of the brain's metabolic activity occurred following intracisternal metrizamide injection. When compared with the mock-CSF control group the greater relative changes were observed in the supratentorial grey matter structures. In contrast, no significant changes were observed in metabolic brain activity in rats treated intracisternally with iopamidol and iohexol. These findings were consistent with the hypothesis that metrizamide is a competitive inhibitor of human brain hexokinase. The apparent lack of interference on neural tissue metabolism makes the second generation contrast media less neurotoxic and more suitable for neuroradiological subarachnoid investigations in clinical settings. The present experimental work establishes the 2-DG method as a viable laboratory approach to investigate aspects of neuronal dysfunction induced by contrast media.

Animals↗
PubMedDate not supplied

[Laparoscopic adrenalectomy in the treatment of malignant adrenal lesions].

The role of laparoscopic approach for the treatment of malignant adrenal diseases is still controversial. The aim of this study was to verify the results of laparoscopic adrenalectomy in the management of adrenal malignancies. The medical records of all the patients who underwent laparoscopic procedures for adrenal diseases and in whom malignancy was demonstrated at final histology were reviewed. Nine patients were included (3 malignant pheochromocytomas, 4 adrenocortical carcinomas and 2 adrenal metastases). At a mean follow-up of 17.0 +/- 12.8 months (range, 2-36), all but two patients were alive and disease free. One patient died for unrelated causes. No patient developed local or port site recurrence. The results of this study demonstrate that laparoscopic adrenalectomy can be safe and effective also in case of adrenal malignancies. Conversion to open surgery in mandatory in case of local invasion and when the dissection cannot be as accurate as in conventional operations. A preliminary laparoscopic exploration can be planned in case of suspected malignant lesions to confirm the diagnosis and to evaluate their operability.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

[Differentiated tumor of the thyroid in children and adolescents].

Differentiated thyroid carcinoma (DTC) is rare in young patients and represents 0,5 to 3,0% of childhood carcinomas. The incidence increases with age: a peak incidence is observed between 15 and 19 years of age. DTC in children is frequently associated with greater risk of cervical lymph node involvement (60-80% of cases) and lung metastases at diagnosis in 20% of patients. However the prognosis for these patients is better when compared with that of adults, despite a high incidence of relapse, leading to reoperation. Young age (<16 years), lymph node involvement or distant metastases at diagnosis and some histopathologic characteristics have been suggested as predictive factors of recurrences. The records of 33 patients with DTC in a 14-year period (1990-2004) were reviewed. There were 31 females and 2 males who ranged from 11 to 21 years. At the diagnosis 15 patients had disease confined to the thyroid, 18 had additional lymph node metastases in the neck; one of them had also lung metastases. Total thyroidectomy (TT) was the elective approach in all patients (4 cases videoassisted). TT was associated to functional neck dissection in 21 cases. 131I was administrated to 28 patients (3,7 GBq as ablative dose): 11 of this received further radioiodine treatments (mean 7,4 GBq) because of elevated serum thyroglobulin levels and presence of loco-regional or lung metastasis at diagnostic total body scan after 131I treatment. The overall survival rate was 100% at a follow up of 4 months to 14 years.

Adolescent↗
PubMedDate not supplied

Effect of x-radiation to brain on cerebral glucose utilization in the rat.

We assessed, by means of the [14C]-2-deoxy-D-glucose autoradiography method, the effect of whole-brain x-radiation on local cerebral glucose utilization in the rat brain. Animals were exposed to conventional fractionation (200 +/- cGy/day given 5 days a week) to a total dose of 4000 cGy. Metabolic experiments were made 2 weeks after completion of the radiation exposure. In comparison with control and sham-irradiated animals, cerebral metabolic activity was diffusely decreased following irradiation. Statistically significant decreases in metabolic activity were observed in 13 of 27 brain regions studied. In general, brain areas with the highest basal metabolic rates showed the greatest percentage drop of glucose utilization. Post-irradiation metabolic alterations possibly provide an explanation for the syndrome of early delayed deterioration observed in humans after whole-brain radiotherapy.

Animals↗
PubMedDate not supplied

Pattern recognition analysis of cardiovascular reflexes: its application in the diagnosis of autonomic neuropathy.

We describe pattern recognition analysis of six cardiovascular reflex tests and its application in the diagnosis of autonomic neuropathy. A discriminating model was performed by SIMCA method using the results of 85 healthy subjects. The prediction ability of the model was then verified with data from 95 patients at risk for autonomic neuropathy. Specificity resulted 93% and sensitivity 97%. The method increases the diagnostic efficiency of the tests, being particularly useful in patients with borderline autonomic involvement.

Adult↗
PubMedDate not supplied

Effect of intracarotid injection of iopamidol on local cerebral glucose utilization in rat brain.

We assessed, by means of the [14C]-2-deoxy-D-glucose autoradiography method, the effect of intracarotid injection of a nonionic, low-osmolar contrast medium (iopamidol) on local cerebral glucose utilization in the rat brain. Contrast medium was injected at 20 degrees C and at 37 degrees C, and the relative changes in local cerebral glucose utilization were measured. At 20 degrees C the viscosity of the contrast agent was about twice that of the same solution at 37 degrees C, and resulted in a statistically significant increase in local cerebral glucose utilization in the hemisphere ipsilateral to the side of intracarotid infusion. Saline control studies showed that the metabolic change was not related to either the solution temperature or the osmolality. These findings suggest that increased viscosity of a contrast medium may contribute to its neurotoxic effects during cerebral angiography, hence emphasizing the importance of preheating contrast material to avoid adverse reactions.

Animals↗