This paper describes a method suitable for purifying immunotoxin containing type 1 ribosome-inactivating protein, gelonin. The separation of free (unreacted) 80G, a monoclonal antibody against alpha-fetoprotein (AFP), from semipurified 80G-gelonin conjugate was unsuccessful by conventional CM-Sepharose ion-exchange chromatography because the isoelectric point of the conjugate did not increase enough to reach that of gelonin alone. In contrast, Blue Sepharose affinity chromatography could efficiently separate free 80G from the semipurified conjugate because the conjugate was bound to the column by its gelonin moiety while free 80G was not in buffer containing NaCl of a particular concentration range. However, a small amount of conjugate containing gelonin modified with N-succinimidyl 3-(2-pyridyldithio)propionate, but not with 2-iminothiolane, could not bind to the column. The conjugate purified by the use of Blue Sepharose showed selective cytotoxicity against AFP-producing human hepatoma cells.

Antibodies, Monoclonal↗

PubMedDate not supplied

MR signal intensity changes in hepatic parenchyma with ductal dilation caused by intrahepatic cholangiocarcinoma.

MR images of the liver in 13 patients with surgically proven intrahepatic cholangiocarcinoma were reviewed retrospectively and correlated to the histologic analysis of surgical specimens. We paid special attention to the peripheral liver tissue with ductal dilation but without tumorous involvement. High signal intensity was observed in the hepatic parenchyma with ductal dilation on T1-weighted spin-echo images (8 of 12) and spoiled gradient-recalled echo images (seven of seven), as compared with the contralateral hepatic lobe without duct dilation. The high signal intensity was not suppressed with fat saturation and showed enhancement after administration of contrast (11 of 12). Concurrent portal venous obstruction did not have significant effect on these findings (P < .05). Correlation with pathologic specimens suggested that this enhancement was associated with periportal fibrosis. The etiology of the high signal intensity on unenhanced spin echo or gradient-recalled T1-weighted image remains unclear. Radiologists should recognize these findings and should distinguish these from tumor involvement or the arterial buffer response caused by portal venous obstruction.

Bile Duct Neoplasms↗

PubMedDate not supplied

Dynamic MRI of the gallbladder lesions: differentiation of benign from malignant.

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.

Adult↗