SUMMARYKawasaki disease (KD) is an acute febrile illness caused by vasculitis, occurring in early childhood. We have demonstrated that the activation of monocytes/macrophages plays a central role during acute KD. Recently, it has been reported that the CD14 1 CD16 1 monocyte subpopulation plays a more important role in inflammation. In this study, we investigated the peripheral blood CD141 CD16 1 monocyte subpopulation by flow cytometry, and serum levels of IL-10 and IL-12 using a sandwich ELISA in 28 KD patients. We also investigated this subpopulation in patients with bacterial infections, mononucleosis and anaphylactoid purpura, since the cause of KD remains unknown. We observed an increase in the number of CD141 CD16 1 monocytes with acute KD, which was a positive correlation with C-reactive protein levels, and we observed only the patients with severe bacterial infections had increased this subpopulation during the acute stage among control diseases. In addition, we found that the serum levels of IL-10, but not IL-12, were higher during acute KD. These data suggest that increased peripheral blood CD14 1 CD16 1 monocytes are part of the regulatory system of monocyte function during acute KD.

Glutamate dehydrogenase (GDH) is important in normal glucose homeostasis. Mutations of GDH result in hyperinsulinism/hyperammonemia syndrome. Using PCR/single-strand conformation polymorphism analysis of the gene encoding GDH in 12 Japanese patients with persistent hyperinsulinemic hypoglycemia of infancy (PHHI), we found a mutation (Y266C) in one PHHI patient. This mutation was not found in any of the control or type 2 diabetic subjects. The activity of the mutant GDH (GDH266C), expressed in COS-7 cells, was constitutively elevated, and allosteric regulations by ADP and GTP were severely impaired. The effect of the unregulated increase in GDH activity on insulin secretion was examined by overexpressing GDH266C in an insulinoma cell line, MIN6. Although glutamine alone did not stimulate insulin secretion from control MIN6-lacZ, it remarkably stimulated insulin secretion from MIN6-GDH266C. This finding suggests that constitutively activated GDH enhances oxidation of glutamate, which is intracellularly converted from glutamine to ␣-ketoglutarate, a tricarboxylic acid cycle substrate, which thereby stimulates insulin secretion. Interestingly, insulin secretion is also exaggerated significantly at low glucose concentrations (2 and 5 mmol/l) but not at higher glucose concentrations (8 -25 mmol/l). Our results directly illustrate the importance of GDH in the regulation of insulin secretion from pancreatic ␤-cells.

Background and Purpose-Kawasaki disease is a febrile disease of children notable for systemic vasculitis. There have been many previous reports of various complications, including disorders of the central nervous system. We evaluated cerebral perfusion during the acute stage in patients with Kawasaki disease. Methods-Single-photon emission-computed tomography (SPECT) with 99m Tc-hexamethylpropyleneamine oxime was performed in 21 children with acute stage Kawasaki disease. Follow-up SPECT and MRI were performed about 1 month after the first SPECT in patients who exhibited abnormal SPECT findings during the acute stage. Results-In 6 of 21 children SPECT imaging demonstrated localized cerebral hypoperfusion without abnormal neurological findings or clinical symptoms, and the follow-up SPECT and MRI approximately 1 month after the first SPECT revealed no abnormalities. Conclusions-Some patients with Kawasaki disease have transient localized cerebral hypoperfusion at the acute stage.

To elucidate the genetic etiology of persistent hyperinsulinemic hypoglycemia of infancy (PHHI) in the Japanese population, we conducted a polymerase chain reaction-single-strand conformation polymorphism analysis of the sulfonylurea receptor 1 (SUR1) and Kir6.2 genes in 17 Japanese PHHI patients, including a pair of siblings from a consanguineous family. We also analyzed the glutamate dehydrogenase gene for the exons encoding an allosteric regulatory domain of the enzyme. In the SUR1 gene, we identified one frameshift (I446fsdelT) and two missense (R1420C, R1436Q) mutations. None of these mutations were found in control Japanese subjects. Siblings homozygous for the R1420C mutation had a mild form, whereas two patients heterozygous for the I446fsdelT and R1436Q mutations, respectively, exhibited a severe form of PHHI. Functional consequences of these mutations on K AT P function were evaluated using 8 6 R b + e fflux studies in COS-7 cells. SUR1-446fsdelT and SUR1-1436Q did not form a functional K AT P . Western blot analysis after transient expression in COS-7 cells revealed the expression of SUR1-1436Q protein to be markedly reduced, suggesting SUR1-1436Q to be unstable in these cells. K AT P ( S U R 1 -1 4 2 0 C ) showed reduced responses to metabolic inhibition by oligomycin and 2-deoxyglucose. K AT P c h a n n e l s are under complex regulation by intracellular ATP and ADP. AT P both inhibits and activates these channels. The inhibition is probably mediated through direct ATP interaction with a pore-forming subunit Kir6.2, whereas the activation is likely to be through a regulatory subunit SUR1. There is a cooperative regulation of ATP and ADP binding to SUR1, and this cooperativity may be involved in regulating the K AT P channel. 256450) is characterized by inappropriately elevated insulin secretion in the presence of hypoglycemia. Mutations have been identified in the genes encoding subunits of the ATP-sensitive potassium channel ( K AT P ), sulfonylurea receptor 1 (SUR1), and Kir6.2 genes in recessive and sporadic forms of PHHI (1-8). Mutations were also identified in the glucokinase gene (9) and in the glutamate dehydrogenase gene in patients with hyperinsulinemic hypoglycemia and hyperammonemia (10). However, the genetic etiology of PHHI in Japanese patients is unknown.The K AT P channel, a heterooctamer composed of two essential subunits, SUR1 and Kir6.2 (BIR) (11), plays a central role in glucose-induced insulin secretion in pancreatic -cells (12-15). Kir6.2, a pore-forming subunit and a member of the weak inward rectifier family (11), has been suggested

SUMMARYKawasaki disease (KD) is an acute febrile illness of early childhood, in which the activation of monocytes/macrophages plays a central role in the development of vasculitis during the acute stage of disease. In this study we investigated peripheral blood T cells of 10 patients with KD, focusing on the Th1 and Th2 imbalance, using intracellular cytokine staining and analysis of the cytokine-producing T cells by¯ow cytometry. We observed a decrease in the numbers of IFN-g-producing, but not IL-4-producing, CD3T cells, during the acute stage. Our results suggest that there is an imbalance of Th1 and Th2 subsets during the acute stage of KD.