[Modern sonographic imaging of abdominal neuroendocrine tumors]. / Moderne sonographische Bildgebung bei neuroendokrinen Tumoren des Abdomens.

BACKGROUND: Radiological and nuclear medical diagnostics play an important role in the work-up of patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET). The sonographic examination, including contrast-enhanced examination, depicts an initial imaging modality to screen for NET. This report describes the sonomorphological behavior of ileal and pancreatic NET as well as hepatic metastases from NET. CLINICAL/METHODICAL ISSUE: Sonographic evaluation of NET of the small intestine, pancreas and neuroendocrine hepatic metastases. STANDARD RADIOLOGICAL METHODS: Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), unenhanced ultrasonography. METHODICAL INNOVATIONS: Contrast-enhanced ultrasound (CEUS). PERFORMANCE: CEUS supports unenhanced ultrasound in the detection of NET and the differential diagnosis of unclear lesions, and is more sensitive for liver metastases (sensitivity according to the literature, 99% vs. 68%) PRACTICAL RECOMMENDATIONS: CEUS allows initial evaluation of NET and differentiation of benign vs. malignant lesions. Nevertheless, CEUS cannot replace more elaborate imaging modalities like CT or MRI for thorough staging examinations.

Preoperative ultrasonography as a mean of predicting the conversion of mini cholecystectomy into classic cholecystectomy.

UNLABELLED: Cholecystectomy is considered to be the treatment of choice in symptomatic biliary lithiasis. Lately, due to medical progress, classic cholecystectomy has been gradually replaced by laparoscopic cholecystectomy and by mini cholecystectomy. Therefore, it is very important to determine certain preoperative factors which might predict the conversion of mini cholecystectomy (MC) into classic cholecystectomy (CC). MATERIAL AND METHOD: The possibility of selecting high-risk conversion patients has important clinical implications, both for the surgeon and for the patient. Differentiating preoperative risk allows the surgeon to inform the patient about a high conversion risk to CC, and about the ensuing consequences: longer hospitalization period, longer postoperative recovery, greater costs. All the patients were examined by ultrasonography. The tests recorded six parameters: the diameter of the biliary duct (mm), the number of calculi, the diameter of the largest calculus (mm), the contracted aspect of the gallbladder, the distance between the tegument and the gallbladder fundus (cm), the distance between the tegument and the cystic duct (cm). All the variables were introduced into an initial model, which was checked using the colinearity method and significant observations, and subsequently reduced by eliminating insignificant predictive factors, revealed by Wald tests. RESULTS: The significant predictive conversion factors to CC, quantified on the basis of regression analysis, are: age > 70, calculus with a diameter > 20 mm, biliary duct with a diameter > 6 mm, contracted gallbladder, distance between the tegument and gallbladder fundus > 7.2 cm, distance between the tegument and cystic duct > 17.1 cm. CONCLUSION: Being a procedure that can be carried out on an outpatient basis and with rather low costs, ultrasonography plays a very important role in the preoperative prediction of converting MC to CC.

Neurons of origin of the neurotensinergic plexus enmeshing the ventral tegmental area in rat: retrograde labeling and in situ hybridization combined.

The morphological and physiological substrates that underlie the mutual regulatory interactions of neurotensin and dopamine in the rat mesotelencephalic projections and related structures remain to be fully described. A salient candidate for neurotensinergic effects on the mesotelencephalic dopamine projection is the dense plexus of neurotensin immunoreactive axons that enmeshes the ventral tegmental area and substantia nigra, but the locations of the neurons that give rise to this plexus have not been identified and its systemic context remains obscure. To address this, Fluoro-Gold and the cholera toxin beta subunit, retrogradely transported axonal tracers, were injected into the ventral tegmental area of rats and the brains were processed to demonstrate neurons that contained both retrograde tracer immunoreactivity and a probe against neurotensin/neuromedin N messenger RNA. Substantial numbers of double-labeled neurons were observed in the rostral part of the lateral septum, and in a region centered on the shared boundaries of the bed nucleus of stria terminalis, ventromedial ventral pallidum, diagonal band of Broca, lateral preoptic area and rostral lateral hypothalamus. A few double-labeled neurons were also observed in the dorsal raphe nucleus and adjacent periaqueductal gray. Despite the administration of haloperidol and D-amphetamine to elicit and enhance neurotensin/neuromedin N messenger RNA expression in striatum, including the nucleus accumbens and olfactory tubercle, no double-labeled neurons were observed there. These results identify a novel brain substrate for control of midbrain dopamine levels, which affect reward mechanisms and motivation.