Correlation of magnetic resonance (MR) imaging findings and those at pathologic evaluation was attempted in six cases of solid and papillary epithelial neoplasm of the pancreas. All patients were female, and the mean patient age was 26 years (range, 13-73 years). On T1-weighted spin-echo images, tumors were well demarcated, and areas of high signal intensity were evident within them. At macroscopic examination, these areas corresponded to solid portions with marked hemorrhagic necrosis or cystic portions filled with hemorrhagic debris. In three of four masses surrounded by macroscopically evident fibrous capsules, a rim of low intensity was revealed at T1-weighted imaging. When T1-weighted spin-echo imaging reveals obvious areas of high intensity within a sharply marginated tumor of the pancreas, especially in a young woman, solid and papillary epithelial neoplasm might be a primary diagnostic consideration.

Angiomyolipoma is a benign mesenchymal tumor that has been reported frequently in the kidney but rarely in the liver. In the present study, we present four cases of hepatic angiomyolipoma with different radiologic appearances, discuss differential diagnosis, and review previously reported cases. One of our cases was followed for 8 years. Computed tomography (plain, enhanced, and dynamic study), magnetic resonance imaging (T1-weighted spin echo, T2-weighted spin echo, and dynamic study), ultrasonography, and angiography were performed in all cases. Although different radiologic appearances were observed in the tumors, based on different proportions of fat, blood vessels, and muscle, three cases were diagnosed as angiomyolipoma. In one case, it was quite difficult to make radiologic diagnosis; hepatocellular carcinoma with fatty metamorphosis in part was most likely suspected, but histopathological examination revealed angiomyolipoma with few fat elements. In the present study, early and prolonged enhancement of the lesion with the special pattern of time density/intensity curve was significant for angiomyolipoma, and we suggest that preoperative radiologic diagnosis of the lesion is possible in most of the cases. However, it can be quite difficult to distinguish angiomyolipoma from some hepatocellular carcinomas with fatty metamorphosis.

Pseudolesions are caused by portal perfusion defects and may receive an aberrant blood supply.

RESULTSThe neurogenic relaxation and cGMP production in response to electrical-field stimulation were significantly impaired in aged cavernosal specimens. Western blot analysis showed that nNOS protein was highly expressed in cavernosal specimens from young rabbits, but was undetectable or greatly decreased in old rabbits, with no change in overall NOS activity. Arginase activity in aged cavernosal specimens was significantly higher than in young rabbits. Supplementing with excess L -arginine, or giving S-(2-boronoethyl)-L -cysteine as an arginase inhibitor, significantly increased the neurogenic relaxation at lower frequencies only in the younger rabbits. CONCLUSIONThese results suggest that impairment of neurogenic and NO-mediated relaxation in the aged corpus cavernosum possibly results from the down-regulation of nNOS protein. The reduced L -arginine bioavailability to nNOS due to accelerated arginase activity would lead to further impairment of neurogenic NO production, in concert with decreased nNOS protein expression. KEYWORDSneuronal nitric oxide synthase, arginase, erectile dysfunction, ageing OBJECTIVETo investigate whether changes in neuronal nitric oxide synthase (nNOS) protein expression and arginase activity are implicated in impairing the neurogenic cavernosal relaxation in aged rabbits, as NO is important in the neurogenic relaxation of corpus cavernosum during the erectile state. MATERIALS AND METHODSCavernosal specimens of young adult (3-6 months old) and aged (36-48 months old) rabbits were used for isometric tension experiments, Western blot analysis, cGMP determination and measurements of NOS and arginase activities.

We compared the growth rate of locally recurrent hepatocellular carcinoma (HCC) with that of primary HCC. After the first treatment by transcatheter arterial chemoembolization (TACE), 60 locally recurrent HCC nodules were reviewed. The tumor volume doubling time (DT) of locally recurrent HCC was significantly shorter than that of primary HCC. The 95% lower threshold value was 17.7 days. The 6-, 12-, and 36-month recurrence-free rates of the tumors having DTs more than 70 days after the second TACE (77.7%, 53.8%, and 40.4%) were significantly higher than those of the tumors having DTs less than 70 days (26.7%, 26.7%, and 17.8%). Locally recurrent HCCs cannot double in diameter in less than 53 days. In the case that an equivocal lesion smaller than the section collimation depicted during a contrast-enhanced computed tomography (CECT) screening cannot be ruled out as local recurrence, the next CECT screening should be performed 2 months later.