Search PubMed⌕ Search

Biomedical subjects

Stefano Colagrande

Publications and source records attributed to Stefano Colagrande.

7 recordsLinked to original sources
PubMed2004

Persistent contrast enhancement by sterically stabilized paramagnetic liposomes in murine melanoma.

In the present research, we investigated the use of paramagnetic liposomes as contrast agents (CAs) for the detection of solid tumors. The liposomes were sterically stabilized by a polyethylene glycol (PEG) coating, and their size was constrained to approximately 100 nm. Dimyristoyl-sn-glycero-3-phosphoethanolamine-N-diethylene-triaminepentaacetate (DMPE-DTPA) was used as the gadolinium-carrying fatty acid chain. The relaxation properties were characterized through nuclear magnetic relaxation dispersion (NMRD) measurements, and analyzed with the use of theories and computer programs that are adequate for slowly rotating systems. Their relaxivity at 1.5 T was found to be acceptable for in vivo use. We then tested the liposomes against B16-F10 murine melanomas using standard T1-weighted schemes at 1.5 T, and concentrations corresponding to 0.03 mmol/kg of gadolinium (i.e., three to six times lower than the concentration of the small gadolinium complexes in clinical use). The blood half-life was found to be 120 +/- 20 min. The experiments show a good contrast enhancement in the tumor (33% +/- 22%) 2 hr after administration, a further increase (43 +/- 27%) 20 hr after administration, and a decrease (25% +/- 14%) 54 hr after administration. High persistence of the CA was also observed in the liver and intestine, as expected in a hepatobiliar excretion pathway.

Animals↗
PubMed2003

Spiral computed tomography versus ultrasound in the follow-up of cirrhotic patients previously treated for hepatocellular carcinoma: a prospective study.

BACKGROUND/AIMS: To assess the value of hepatic-arterial-phase computed tomography (HAP-CT) versus ultrasound (US) plus alpha-fetoprotein (AFP) in the surveillance of cirrhotic patients with previously treated hepatocellular carcinoma (HCC). METHODS: Thirty-six cirrhotic patients, treated for single nodular HCC <4cm with complete response and no evidence of other focal lesions, were enrolled in a prospective study and underwent simultaneous AFP/US/spiral-CT follow-up every 6 months. Focal lesions were considered recurrences when they appeared as globular enhancement areas (EA) at HAP-CT and increased in size during the follow-up. RESULTS: Fifteen of 36 patients showed at least one focal lesion for a total of 43 EA: 38/43 increased in size, four did not change and one disappeared. EA were first observed after a follow-up of 9+/-4 (range 6-18) months. At the same time, no patient had either nodular lesion at US examination or diagnostic levels of AFP. In 22 matched lesions, diagnosis by CT was 8.2+/-3.5 months earlier than by US. In 13 patients, one evolved EA was submitted to US-guided biopsy and histological examination showed HCC in all cases. CONCLUSIONS: Periodical spiral-CT examination is more effective than US-AFP in early detection of HCC recurrence in cirrhotic patients successfully treated for HCC.

Aged↗
PubMed2003

[Meaning and etiopathogenesis of sectorial transient hepatic attenuation differences (THAD)].

PURPOSE: To examine sectoral transient hepatic attenuation differences (THAD) in an attempt to correlate semeiotics with etiopathogenesis and to deduce a possible diagnostic value. MATERIALS AND METHODS: Over a period of three years (January 1998-January 2001) we observed 130 THAD in 988 patients, and we selected 30 sectoral THAD in 18 patients (10 males and 8 females), ranging in age from 24 to 82 years (average = 63.3). The 18 patients comprised 6 cancer patients undergoing CT staging/restaging, 5 cirrhotic patients being studied for possible hepatocellular carcinoma, 7 patients undergoing helical CT to further investigate clinical and/or US findings. For each patient a biphasic helical CT liver examination was performed, during the arterial and portal dominant phase. After the first diagnosis, all patients were followed up for 12 months with at least one US and helical CT examination; 8/18 were also studied by MRI. RESULTS: Thirty THAD were associated with 14 metastatic lesions, 4 hepatocellular carcinomas, 1 cholangiocarcinoma of the liver, 4 haemangiomas, 3 abscesses, 1 FNH, 2 cases of arterioportal shunting (APS) and 1 fine-needle percutaneous biopsy. Nine THAD turned out to be the sole sign of disease and occurred at least 3/6 months before the causal focal lesion had become detectable. At the first examination, all focal lesions had a maximum diameter of 2 cm; the size of THAD varied from 1 to 5 cm. All of the THAD were sectoral, with the base side represented by the glissonian capsule and the apex towards the parenchyma. 27/30 THAD were connected to focal lesions: 24/27 were fan-shaped and the lesion was situated at the apex of the triangle; 3/27 were roughly wedge-shaped and the lesion was entirely inscribed in the hyperattenuating area. 3/30 were not connected to focal lesions, being in 2 cases fan-shaped and in only one case irregularly shaped. CONCLUSIONS: Sectoral THAD may or may not be connected to focal lesions. Whenever a sectoral THAD not connected to a focal lesion is detected, all of the possible causes should be considered: portal or superhepatic vein thrombosis, traumatic (biopsy) or cirrhotic intraparenchymal APS, or a benign occult nodule. If none of these explanations are confirmed, we should consider the possibility of an occult malignant lesion.

Adult↗