Nitric oxide synthase as a marker in colorectal carcinoma.

Elevated inducible nitric oxide synthase (iNOS) activity has been found in 60 per cent of colon adenomas and 20 to 50 per cent of adenocarcinomas. We postulated that high levels of iNOS may increase the invasive and metastatic potential of colon carcinoma and could be indicative of survival potential. Data were reviewed for 52 patients with colorectal carcinoma diagnosed in 1991 and 1992. Specimens were stained for iNOS and catalogued as low-activity staining (LAS) or high-activity staining (HAS) on the basis of visual evaluation by three pathologists. Thirty patients were LAS and 22 HAS. Age, sex, preoperative carcinoembryonic antigen, tumor and nodal status, and American Joint Committee on Cancer staging were not different between groups. Forty-six per cent of the HAS group remained alive after 5 years versus 71 per cent in the LAS group. Survival was significantly lower and metastatic status significantly higher in the HAS group. Results indicated that iNOS activity may be a prognostic indicator of long-term survival potential after treatment for colon cancer. In addition results suggested that metastasis was greater in colon carcinoma specimens that maintain an activated iNOS and that these cells clinically react more aggressively. Conclusions are tempered by the fact that results were based on a limited sample size.

Splenic arteries and veins in pediatric sickle cell disease.

The goal of this study was to verify the existence and prevalence of large vessel lesions outside the central nervous system in young patients with sickle cell disease. Thus, 17 spleens resected because of episodes of sequestration or infarction and 41 controls were studied. Anomalies of arteries and veins were detected in all spleens from sickle cell disease patients, but no definite correlation with age, sex, type of sickle hemoglobin, or frequency of sequestration episodes could be established. The most consistent lesions were intimal proliferation affecting large arteries and veins, reduplication of the internal elastic lamina of large arteries, and a lesion not previously documented in this condition, that of subendothelial infiltration of the large veins by activated T cells. Endotheliitis showing some similarity with the one seen in sickle cell disease spleens was noted in 5 of 41 spleens of patients who did not suffer from sickle cell disease. However, when present it was usually mild. Very limited damage to the arterial elastica was noted in only 1 of the 41 controls. Minimal endothelial proliferation was seen in 2 of 41 controls.