Plasma and intracellular levels of lactate dehydrogenase, phosphohexose isomerase and lysozyme activity in acute leukemia

Human hepatoma cells synthesize and secrete lysozyme: modulation by cytokines

Plasma lysozyme levels are elevated in several different pathological conditions. In our study we show that well differentiated human hepatoma cells Hep3B and HepG2 are active synthesis sites of lysozyme and that this synthesis can be modulated by acute phase mediators. The production and modulation of lysozyme synthesis was studied by means of Northern-blot analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a specific bioassay after treatment of the cells with interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha. Hep3B and HepG2 cells constitutively synthesize high amounts of lysozyme. Lysozyme synthesis and secretion were found to be augmented by interleukin-1 beta and tumor necrosis factor-alpha in both cell lines. Interleukin-6 caused an increase in lysozyme production in Hep3B but a decrease in the HepG2 cells. As expected, the synthesis of albumin was decreased in both cell lines. Furthermore we demonstrated that HepG2 and Hep3B cells produce a biologically active form of the enzyme as measured by a specific bioassay. The results demonstrate that lysozyme is constitutively synthesized by Hep3B and HepG2 hepatoma cell lines and that lysozyme synthesis is modulated by acute-phase mediators. Well differentiated human hepatoma cells may respond differently to different cytokines.

Serum enzyme concentrations in untreated acute myeloid leukaemia

Serum concentrations of lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBD), phosphohexose isomerase (PHI), leucine aminopeptidase (LAP), beta-glucuronidase (beta-gluc) and angiotensin-converting enzyme (ACE), were measured in 107 cases of untreated acute myeloid leukaemia which were classified by morphological, immunological and cytochemical criteria. The results show that serum LDH was increased in most cases, irrespective of leukaemic subtype, serum PHI and LAP were significantly higher in monocytic variants and serum beta-gluc and ACE levels were generally within normal limits. In addition, significant (p less than 0.05) relationships were found between serum LDH, PHI, LAP and beta-gluc concentrations and the numbers of circulating leucocytes.