In order to assess the influence of poor diabetes control on function of leukocytes, polymorphonuclear leukocytes (PMN's) from patients with poorly controlled but nonketotic disease were studied before and after therapy. Before treatment, phagocytosis was significantly reduced (p < .001) and, consequently, the rate of killing the test organism (type 25 pneumococcus) was decreased (p < .01). Following antidiabetes therapy phagocytosis improved significantly; while microbicidal rates also improved, they remained less than control values (p < .01).Serum from the untreated diabetics uniformly reduced phagocytosis and microbicidal rates of control granulocytes; serum from controls improved phagocytosis by the diabetic PMN's, but restored normal microbicidal rates in only half of the patients. This transferable inhibitory effect of hyperglycemic diabetic serum on control granulocytes was abolished by dilution, and was reproduced in normal serum by the isosmotic addition of glucose. These studies suggest that (1) PMN function may be impaired during periods cf poor diabetes control, as has been shown previously in ketoacidosis, and (2) hyperglycemia or a closely related factor may contribute to the defect. DIABETES 23:9-15, January, 1974. It has long been believed that an abnormality in host defense predisposes the diabetic patient to both bacterial and fungal infection. However, experimental approaches to the study of host defense in the diabetic have often yielded confusing and conflicting results and, in general, have failed to consistently demonstrate either a humoral or a cellular defect which might increase the susceptibility of diabetic patients to infection. 1

Using a specific and sensitive fluorometric assay, the H2O2 release from as few as 2 X 10(5) mouse peritoneal macrophages could be detected continuously and quantitated. It is emphasized that the assay measured H2O2 release, not production. Induction of H2O2 release required sequential application of two stimuli: the administration of an activating agent to the mice from 4 days to 10 wk before all harvest, and the exposure of the cells in vitro to a triggering agent. BCG was most effective as an activating agent, resulting in peritoneal macrophages which could be triggered to release H2O2 almost as copiously (8 nmol/10(6) macrophages per 5 min) as mouse peritoneal PMN (9 NMOL/10(6) PMN per 5 min). Casein and C. parvum could also serve as activators, but thioglycollate and FCS were ineffective after single injections. PMA was a potent triggering agent, resulting in a maximal rate of H2O2 release after a latency of about 40 s for cells in suspension. Other triggering agents included the ionophore A23187, concanavalin A in the presence of cytochalasin B, and phagocytosis. H2O2 release could be attributed to macrophages and PMN in peritoneal cell suspensions or in preparations of adherent peritoneal cells, but not to lymphocytes. Indirect evidence suggested that the H2O2 detected was formed from superoxide anion. These observations appear to justify renewed interest in the idea that H2O2 may be important in macrohpage antimicrobial and antitumor mechanisms.

A B S T R A C T The extinction of fluorescence of scopoletin during its oxidation by horseradish peroxidase (HPO) provides a highly sensitive and specific assay for small quantities of peroxide in solution. With this assay, the release of free H2sO into the extracellular medium by phagocytizing human granulocytes has been documented and quantitated, and some of the regulating factors have been determined. Under basal conditions granulocytes released less than 0.01 nmol/ml of H20. (2.5 X 10' polymorphonuclear leukocytes/ml). Upon the addition of phagocyte particles (latex, opsonized yeast, or staphylococci), an abrupt increase in extracellular peroxide concentration was observed (>50-fold above basal levels) after latencies as short as 10 s. Release reflected increased intracellular H202 production during phagocytosis in that it paralleled the respiratory burst and was absent when phagocytosis was prevented or when cells from patients with chronic granulomatous disease were utilized. Evidence that scopoletin oxidation occurred predominantly in the extracellular medium was obtained by demonstrating a marked inhibition when HPO was omitted from the reaction mixture or when exogenous catalase was added. Similarly, it was found that exogenous serum also inhibited scopoletin oxidation, apparently because of the presence of competing hydrogen donors.H202 formation and release were observed at rates which closely paralleled those of phagocytosis. With O2 consumption as an approximate index of H202 formation, the fractions released during maximal rates of Portions of this work were presented at the Eastern and National

B. quintana is a cause of fever, bacteremia, and endocarditis in HIV-seronegative, homeless, inner-city patients with chronic alcoholism.

No abstract