Hiroshi Obayashi

Supplementation of hydrogen-rich water improves lipid and glucose metabolism in patients with type 2 diabetes or impaired glucose tolerance.

Oxidative stress is recognized widely as being associated with various disorders including diabetes, hypertension, and atherosclerosis. It is well established that hydrogen has a reducing action. We therefore investigated the effects of hydrogen-rich water intake on lipid and glucose metabolism in patients with either type 2 diabetes mellitus (T2DM) or impaired glucose tolerance (IGT). We performed a randomized, double-blind, placebo-controlled, crossover study in 30 patients with T2DM controlled by diet and exercise therapy and 6 patients with IGT. The patients consumed either 900 mL/d of hydrogen-rich pure water or 900 mL of placebo pure water for 8 weeks, with a 12-week washout period. Several biomarkers of oxidative stress, insulin resistance, and glucose metabolism, assessed by an oral glucose tolerance test, were evaluated at baseline and at 8 weeks. Intake of hydrogen-rich water was associated with significant decreases in the levels of modified low-density lipoprotein (LDL) cholesterol (ie, modifications that increase the net negative charge of LDL), small dense LDL, and urinary 8-isoprostanes by 15.5% (P < .01), 5.7% (P < .05), and 6.6% (P < .05), respectively. Hydrogen-rich water intake was also associated with a trend of decreased serum concentrations of oxidized LDL and free fatty acids, and increased plasma levels of adiponectin and extracellular-superoxide dismutase. In 4 of 6 patients with IGT, intake of hydrogen-rich water normalized the oral glucose tolerance test. In conclusion, these results suggest that supplementation with hydrogen-rich water may have a beneficial role in prevention of T2DM and insulin resistance.

Hydrogen-rich pure water prevents superoxide formation in brain slices of vitamin C-depleted SMP30/GNL knockout mice.

Hydrogen is an established anti-oxidant that prevents acute oxidative stress. To clarify the mechanism of hydrogens effect in the brain, we administered hydrogen-rich pure water (H(2)) to senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize vitamin C (VC), also a well-known anti-oxidant. These KO mice were divided into three groups; recipients of H(2), VC, or pure water (H(2)O), administered for 33 days. VC levels in H(2) and H(2)O groups were <6% of those in the VC group. Subsequently, superoxide formation during hypoxia-reoxygenation treatment of brain slices from these groups was estimated by a real-time biography imaging system, which models living brain tissues, with Lucigenin used as chemiluminescence probe for superoxide. A significant 27.2% less superoxide formed in the H(2) group subjected to ischemia-reperfusion than in the H(2)O group. Thus hydrogen-rich pure water acts as an anti-oxidant in the brain slices and prevents superoxide formation.

Interleukin-6 polymorphism (-634C/G) in the promotor region and the progression of diabetic nephropathy in type 2 diabetes.

Aims Interleukin‐6 (IL‐6) is a multifunctional cytokine produced by many different cell types, including glomerular mesangial cells. Recently, a novel C/G polymorphism at position −634 in the promotor region of the IL‐6 gene has been reported. The aim of this study was to investigate whether the −634C/G polymorphism is associated with an increased risk for progression to diabetic nephropathy as well as elevated levels of IL‐6 secretion by peripheral blood mononuclear cells.

Serum brain-derived neurotrophic factor in patients with type 2 diabetes mellitus: Relationship to glucose metabolism and biomarkers of insulin resistance

OBJECTIVES The aims of this study were to measure serum levels of brain-derived neurotrophic factor (BDNF) in patients with type 2 diabetes mellitus (T2DM) and to investigate the association of these BDNF levels with biomarkers of glucose metabolism and insulin resistance. DESIGN AND METHODS We studied 112 patients with T2DM and 80 age- and gender-matched control subjects. RESULTS Serum BDNF levels were significantly lower in patients with T2DM compared to control subjects (15.5+/-5.2 ng/mL vs. 20.0+/-7.3 ng/mL, P<0.01). In patients with T2DM, BDNF levels were significantly higher in females than in males (P<0.01). In the female patients, BDNF was positively related to immunoreactive insulin (IRI) (rho=0.458, P<0.05) and HOMA-R (rho=0.444, P<0.05). Stepwise multiple regression analysis showed a significant relationship between BDNF and IRI (F=5.294, P<0.05) in female patients with diabetes. CONCLUSIONS These findings suggest that BDNF may contribute to glucose metabolism.

Antibodies to gangliosides and galactocerebroside in patients with Guillain–Barré syndrome with preceding Campylobacter jejuni and other identical infections

The relationship between preceding infections and antibodies to glycolipids was investigated in 205 Japanese patients with Guillain-Barré syndrome (GBS). Serological evidence of recent Campylobacter jejuni (C. jejuni) infection was found in 45% of the patients, compared with 1% in healthy controls. In contrast, recent infection of cytomegalovirus (CMV), Mycoplasma pneumoniae (M. pneumoniae) and Epstein-Barr virus (EBV) was detected in only 5%, 2% and none of the patients, respectively. C. jejuni-associated GBS was more frequent in early spring than in other seasons. All stool specimens positive for C. jejuni isolation were obtained within 10 days after the onset of GBS symptoms. Of 13 C. jejuni isolates from GBS patients, 10 (77%) belonged to Penner serotype 19 (heat-stable, HS-19). Elevated titers of anti-GM1 antibody were found in 8 (80%) of 10 GBS patients whose C. jejuni isolates belonged to HS-19 and in none of those infected with non-HS-19 C. jejuni (P = 0.04), and in 49% of 92 patients with C. jejuni infection and 25% of patients without infection of C. jejuni, CMV, EBV, or M. pneumoniae (P = 0.0007). The frequencies of elevated antibody titers to GD1a, GD1b and GQ1b were also significantly higher in GBS patients associated with C. jejuni than those not associated with C. jejuni, CMV, EBV, and M. pneumoniae. GBS in Japan seems to be associated more frequently with C. jejuni and less frequently with CMV than in Europe and North America.

Paraoxonase gene polymorphisms and plasma oxidized low-density lipoprotein level as possible risk factors for exudative age-related macular degeneration

PURPOSE Paraoxonase (E.C.3.1.1.2) is a polymorphic protein shown to prevent low-density lipoprotein oxidation. Our purpose is to evaluate the hypothesis that paraoxonase gene polymorphisms and plasma oxidized low-density lipoprotein level play a role in the occurrence of exudative age-related macular degeneration. METHODS We analyzed paraoxonase genotypes (A/B, Gln-Arg192 and L/M, Leu-Met54) and plasma oxidized low-density lipoprotein levels in 72 unrelated Japanese patients with exudative age-related macular degeneration and compared the results with those of 140 age-matched and sex-matched control subjects. RESULTS The distribution of paraoxonase 192 and paraoxonase 54 polymorphisms was significantly different between the patients with age-related macular degeneration and control subjects (chi-square = 6.226, P =.0445, and chi-square = 6.863, P =.0323, respectively). The high frequency of the BB genotype at position 192 was observed in the exudative age-related macular degeneration group compared with control subjects (52.8% vs 35.0%, respectively; P =.0127). The high frequency of the LL genotype at position 54 was observed in the patients more than the controls (91.7% vs 77.1%, respectively; P =.0090). The mean (+/- SE) oxidized low-density lipoprotein levels in the patients was significantly higher than in the controls (19.1 +/- 1.0 vs 16.2 +/- 0.6 U/ml, P <.01). CONCLUSION These results indicate that the paraoxonase gene polymorphisms may represent a possible genetic risk factor for age-related macular degeneration and that increased plasma oxidized low-density lipoprotein may be involved in the pathogenesis of age-related macular degeneration.

Post-infectious encephalitis with anti-galactocerebroside antibody subsequent to Mycoplasma pneumoniae infection

Galactocerebroside (Gc) is a major component of myelin in both the peripheral and central nervous systems. Although it is regarded as an important glycolipid hapten of myelin in rabbit experimental allergic neuritis (EAN), its role in human demyelinating diseases is not known. We studied three post-infectious encephalitis (PIE) patients related to Mycoplasma pneumoniae infection. All three of three patients with encephalitis and M. pneumoniae infection were positive for Gc antibodies (100%), while 25% of 32 M. pneumoniae-infected patients without neurological disease were positive, and 3.8% of 52 healthy controls. This indicates anti-Gc antibody is induced by M. pneumoniae infection. One of the PIE patients, who had extraordinary high titer antibody to Gc, showed an extensive, diffuse white matter demyelination and poor recovery. Since circulating anti-Gc antibody induces central nervous system demyelination in animals with elevated antibody titers and disruption of the blood-brain barrier, anti-Gc antibody may have an important function in the increased demyelination in PIE patients after M. pneumoniae infection.

A Critical Role for Allograft Inflammatory Factor-1 in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is characterized by massive synovial proliferation, angiogenesis, subintimal infiltration of inflammatory cells and the production of cytokines such as TNF-α and IL-6. Allograft inflammatory factor-1 (AIF-1) has been identified in chronic rejection of rat cardiac allografts as well as tissue inflammation in various autoimmune diseases. AIF-1 is thought to play an important role in chronic immune inflammatory processes, especially those involving macrophages. In the current work, we examined the expression of AIF-1 in synovial tissues and measured AIF-1 in synovial fluid (SF) derived from patients with either RA or osteoarthritis (OA). We also examined the proliferation of synovial cells and induction of IL-6 following AIF-1 stimulation. Immunohistochemical staining showed that AIF-1 was strongly expressed in infiltrating mononuclear cells and synovial fibroblasts in RA compared with OA. Western blot analysis and semiquantitative RT-PCR analysis demonstrated that synovial expression of AIF-1 in RA was significantly greater than the expression in OA. AIF-1 induced the proliferation of cultured synovial cells in a dose-dependent manner and increased the IL-6 production of synovial fibroblasts and PBMC. The levels of AIF-1 protein were higher in synovial fluid from patients with RA compared with patients with OA (p < 0.05). Furthermore, the concentration of AIF-1 significantly correlated with the IL-6 concentration (r = 0.618, p < 0.01). These findings suggest that AIF-1 is closely associated with the pathogenesis of RA and is a novel member of the cytokine network involved in the immunological processes underlying RA.

Induction of aldose reductase in cultured human microvascular endothelial cells by advanced glycation end products.

Accelerated formation and accumulation of advanced glycation end products, as well as increased flux of glucose through polyol pathway, have been implicated in the pathogenesis of diabetic vascular complications. We investigated effects of advanced glycation end products on the levels of aldose reductase mRNA, protein, and activity in human microvascular endothelial cells. When endothelial cells were cultured with highly glycated bovine serum albumin, aldose reductase mRNA in endothelial cells demonstrated concentration-dependent elevation. The increase in aldose reductase mRNA was accompanied by elevated protein expression and enzyme activity. Significant increase in the enzyme expression was also observed when endothelial cells were cultured with serum obtained from diabetic patients with end-stage renal disease. Pretreatment of the endothelial cells with probucol or vitamin E prevented the advanced glycation end products-induced increases in aldose reductase mRNA and protein. Electrophoretic mobility shift assays using the nuclear extracts of the endothelial cells treated with advanced glycation end products showed enhancement of specific DNA binding activity for AP-1 consensus sequence. These results indicate that accelerated formation of advanced glycation end products in vivo may elicit activation of the polyol pathway, possibly via augmented oxidative stress, and amplify endothelial cell damage leading to diabetic microvascular dysfunction.

Intercellular adhesion molecule-1 (ICAM-1) polymorphism is associated with diabetic retinopathy in Type 2 diabetes mellitus.

Aims Leucocyte adhesion to the diabetic retinal vasculature has been implicated in the pathogenesis of diabetic retinopathy. We evaluated the relationship between genetic polymorphisms in leucocyte and endothelial cell adhesion molecules and diabetic retinopathy in Type 2 diabetes mellitus.