Catalase activity in human hepatocellular carcinoma (HCC).

Liver catalase activity, one of the free-radical scavenger enzymes, has been measured in 22 normal subjects and compared with that of 13 patients suffering from hepatocellular carcinoma. The activity was estimated both in tumor tissue and in tumor-free tissue. A significant reduction of catalase activity was noted in tumor tissue (p less than 0.001) as well as in the adjacent tumor-free tissue (p less than 0.02). In patients with hepatoma, the serum iron level was lower than in normal (p less than 0.01) and was correlated with enzyme activity (r = 0.958). These findings suggest that in hepatocarcinoma the free radical scavenger system is impaired.

Neutrophil functions, spondylarthropathies and HLA-B27: a study of 43 patients.

OBJECTIVES: Several hypotheses have been proposed regarding the role of HLA-B27 antigen in the pathogenesis of the spondylarthropathies. METHODS: We studied some neutrophil functions in vivo in patients affected by ankylosing spondylitis or by reactive arthritis, with or without HLA-B27, and in healthy control subjects. In vivo neutrophil migration was investigated by Senn's skin window technique. An adhesion assay was also conducted and superoxide production was measured in circulating and migrating neutrophils after different stimuli. RESULTS: Neutrophil migration in vivo was higher in the HLA-B27 positive patients than in the controls, while no difference was found between the HLA-B27 negative patients and controls. Our data showed an increased response to formyl-methionyl-leucyl-phenylalanine by circulating neutrophils in the patients with ankylosing spondylitis, both HLA-B27 positive and negative, in comparison with all the other subjects. CONCLUSIONS: Our results revive the question of the role of HLA-B27 in the regulation of neutrophil migration; the reported in vivo priming of circulating neutrophils seems to be related to ankylosing spondylitis rather than to HLA-B27.

Factor-specific changes in oxidative burst response of human neutrophils in skin-window exudates.

Human neutrophils were isolated from blood and aseptic inflammatory exudates. The respiratory burst response was measured as superoxide (O2-) production by a microplate assay system and polarographically as oxygen consumption. Exudate cells exhibited a respiratory burst in response to n-formyl-methionyl-leucyl-phenyl-alanine (FMLP) that was two- to threefold higher than the burst exhibited by peripheral blood cells. The O2- production induced by substance P was also found to be fivefold higher in exudate cells, while the metabolic response to other stimulants such as concanavalin A (con A), phorbol-myristate acetate (PMA), NaF, and immunocomplexes was not primed. Serum-treated zymosan (STZ)-stimulated activity was primed by only 11%. In contrast, superoxide production in response to tumor necrosis factor-alpha (TNF) was decreased in exudate versus blood cells by about 50%. Therefore, the skin-window cells, compared to blood cells, appear to be at the same time primed, unmodified, and desensitized, according to the different stimulants employed.