Accuracy of the Contour® Next Link 2.4 blood glucose monitoring system in Japanese individuals: a single-center study.

Aims: Self-monitoring of blood glucose is a useful method for monitoring blood glucose. It is often a key role of a management plan to reduce glycemic variability and diabetic complications. Wireless monitoring systems to connect blood glucose and insulin pumps can facilitate glycemic control. In this study, we evaluated the accuracy of Contour® Next Link 2.4, a blood glucose monitoring system that cooperates wirelessly with most insulin pumps, in Japanese individuals. Methods: In this study, finger-stick samples from 59 individuals were collected at the Tokyo Saiseikai Central Hospital. Blood glucose concentrations were measured with the monitoring systems against an available reference. We evaluated the accuracy of the system based on the ISO 15197:2013 Section 6.3 accuracy criteria. Results: In the present study, 100% of the results fulfilled the ISO 15197:2013 Section 6.3 accuracy criteria (95% within ± 15 mg/dL or ± 15% of reference for glucose < 100 and ≥ 100 mg/dL, respectively). The Parkes-Consensus Error Grid analysis showed that 100% of the results fulfilled within Zone A. Conclusions: The Contour® Next Link 2.4 blood glucose monitoring system fulfilled the ISO 15197:2013 accuracy criteria limit and the consensus error grid criterion. Therefore, this monitoring system for observing blood glucose levels is accurate for Japanese individuals.

Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men.

Recent studies have revealed that decline in cellular nicotinamide adenine dinucleotide (NAD+) levels causes aging-related disorders and therapeutic approaches increasing cellular NAD+ prevent these disorders in animal models. The administration of nicotinamide mononucleotide (NMN) has been shown to mitigate aging-related dysfunctions. However, the safety of NMN in humans have remained unclear. We, therefore, conducted a clinical trial to investigate the safety of single NMN administration in 10 healthy men. A single-arm non-randomized intervention was conducted by single oral administration of 100, 250, and 500 mg NMN. Clinical findings and parameters, and the pharmacokinetics of NMN metabolites were investigated for 5 h after each intervention. Ophthalmic examination and sleep quality assessment were also conducted before and after the intervention. The single oral administrations of NMN did not cause any significant clinical symptoms or changes in heart rate, blood pressure, oxygen saturation, and body temperature. Laboratory analysis results did not show significant changes, except for increases in serum bilirubin levels and decreases in serum creatinine, chloride, and blood glucose levels within the normal ranges, independent of the dose of NMN. Results of ophthalmic examination and sleep quality score showed no differences before and after the intervention. Plasma concentrations of N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-5-carboxamide were significantly increased dose-dependently by NMN administration. The single oral administration of NMN was safe and effectively metabolized in healthy men without causing any significant deleterious effects. Thus, the oral administration of NMN was found to be feasible, implicating a potential therapeutic strategy to mitigate aging-related disorders in humans.

GLP-1 receptor agonist, liraglutide, ameliorates hepatosteatosis induced by anti-CD3 antibody in female mice.

AIMS: Hepatosteatosis is mainly induced by obesity and metabolic disorders, but various medications also induce hepatosteatosis. The administration of anti-CD3 antibody was shown to induce hepatosteatosis, but changes in lipid and glucose metabolism remain unclear. We investigated the mechanism of hepatosteatosis induced by anti-CD3 antibody and the effects of glucagon-like peptide-1 (GLP-1) receptor agonist that was recently shown to affect immune function in metabolic disorders. METHODS: Anti-CD3 antibody was administered to female BALB/c and C.B-17-scid mice with or without reconstitution by naïve CD4-positive splenocytes. Hepatic lipid content, serum lipid profile and glucose tolerance were evaluated. Splenic CD4-positive T lymphocytes were stimulated with the GLP-1R agonist, liraglutide, and cytokine production was measured. The effect of liraglutide on metabolic parameters in vivo was investigated in a T-cell activation-induced hepatosteatosis model. RESULTS: The administration of anti-CD3 antibody induced hepatosteatosis, hyperlipidemia, and glucose intolerance. C.B-17-scid mice reconstituted with CD4-positive T lymphocytes developed hepatosteatosis induced by anti-CD3 antibody. Liraglutide suppressed CD4-positive T lymphocyte cytokine expression in vitro and in vivo, and improved hepatosteatosis, glucose tolerance, and insulin sensitivity. CONCLUSIONS: Liraglutide suppressed the activation of CD4-positive T lymphocytes, and improved hepatosteatosis and metabolic disorders induced by T-cell activation in female mice.

Bile acid binding resin prevents fat accumulation through intestinal microbiota in high-fat diet-induced obesity in mice.

BACKGROUND: Bile acid binding resin (BAR) absorbs intestinal bile acids, and improves obesity and metabolic disorders, but the precise mechanism remains to be clarified. Recent findings reveal that obesity is associated with skewed intestinal microbiota. Thus, we investigated the effect of BAR on intestinal microbiota and the role of microbiota in the prevention of obesity in high-fat diet-induced obesity in mice. PROCEDURES: Male Balb/c mice were fed a low-fat diet (LFD), high-fat diet (HFD), or HFD with BAR (HFD+BAR), and then metabolic parameters, caecal microbiota, and metabolites were investigated. The same interventions were conducted in germ-free and antibiotic-treated mice. MAIN FINDINGS: The frequency of Clostridium leptum subgroup was higher in both HFD-fed and HFD+BAR-fed mice than in LFD-fed mice. The frequency of Bacteroides-Prevotella group was lower in HFD-fed mice than in LFD-fed mice, but the frequency was higher in HFD+BAR-fed mice than in HFD-fed mice. Caecal propionate was lower in HFD-fed mice than in LFD-fed mice, and higher in HFD+BAR-fed mice than in HFD-fed mice. HFD+BAR-fed mice showed lower adiposity than HFD-fed mice, and the reduction was not observed in germ-free or antibiotic-treated mice. Colonized germ-free mice showed a reduction in adiposity by BAR administration. Energy expenditure was lower in HFD-fed mice and higher in HFD+BAR-fed mice, but the increments induced by administration of BAR were not observed in antibiotic-treated mice. CONCLUSIONS: Modulation of intestinal microbiota by BAR could be a novel therapeutic approach for obesity.

Bile acid binding resin improves hepatic insulin sensitivity by reducing cholesterol but not triglyceride levels in the liver.

AIMS: Bile acid binding resin (BAR) improves glycaemic control in patients with type 2 diabetes. Although the mechanism is hypothesised to involve the clearance of excess hepatic triglyceride, this hypothesis has not been examined in appropriately designed studies. Therefore, we investigated whether reduced hepatic triglyceride deposition is involved in BAR-mediated improvements in glycaemic control in spontaneous fatty liver diabetic mice without dietary interventions. METHODS: Male 6-week-old fatty liver Shionogi (FLS) mice were fed a standard diet without or with 1.5% BAR (colestilan) for 6 weeks. Glucose tolerance, insulin sensitivity, hepatic lipid content, and gene expression were assessed. A liver X receptor (LXR) agonist was also administered to activate the LXR pathway. We also retrospectively analysed the medical records of 21 outpatients with type 2 diabetes who were treated with colestilan for ≥6 months. RESULTS: BAR enhanced glucose tolerance and insulin sensitivity in FLS mice without altering fat mass. BAR improved hepatic insulin sensitivity, increased IRS2 expression, and decreased SREBP expression. BAR reduced hepatic cholesterol levels but not hepatic triglyceride levels. BAR also reduced the expression of LXR target genes, and LXR activation abolished the BAR-mediated improvements in glycaemic control. Colestilan significantly lowered serum cholesterol levels and improved glycaemic control in patients with type 2 diabetes. CONCLUSIONS: BAR improved hepatic insulin resistance in FLS mice by reducing hepatic cholesterol without affecting hepatic triglyceride levels or body fat distribution. Our study revealed that BAR improves glycaemic control at least in part by downregulating the hepatic cholesterol-LXR-IRS2 pathway.

Minor neuronal damage and recovered cellular proliferation in the hippocampus after continuous unilateral forelimb restraint in normal rats.

Constraint-induced movement therapy (CIMT) involves the restraint of an intact limb to force the dominant use of an affected limb, in an attempt to enhance use-dependent plasticity and reduce dysfunction. To investigate whether forced disuse of an intact forelimb with CIMT causes a loss of limb function and degenerative damage in the brain, a staircase test and a horizontal ladder test were carried out in control rats and forelimb-restrained rats, and then Argyrophil III silver staining, which is capable of detecting subtle neuronal damage, was used to examine histological alterations associated with restraint. No significant changes in forelimb function were observed in restrained rats. However, atypical weak argyrophilic neurons, an indicator of minor neural damage, were found in the bilateral hippocampus of restrained rats. This damage was not found in the cortex, striatum, or spinal cord. Investigation of neurogenesis in the subventricular zone (SVZ) and subgranular zone (SGZ) revealed a clear reduction in the number of bromodeoxyuridine-positive cells in bilateral SGZ, but not in the SVZ, in restrained rats compared with controls. This reduction was accompanied by reduced mRNA expression of vascular endothelial growth factor and glial-derived neurotrophic factor. However, reduced cellular proliferation and decreased gene expression were recovered after the removal of the restraint. Our results suggest that forced disuse of the intact forelimb has no significant effect on skilled forelimb function but has a minor effect on neurogenesis in SGZ, suggesting that mild stress may be caused by the restraint.

Involvement of hypoxia-inducible factor-1alpha and vascular endothelial growth factor in the mechanism of development of chronic subdural hematoma.

Vascular endothelial growth factor (VEGF), a potent inducer of angiogenesis and vascular permeability in diverse physiological and pathological conditions, may be involved in the pathophysiology of chronic subdural hematoma (CSDH). The present study investigated the source and mechanisms for the induction of VEGF in CSDH by measuring the concentration of VEGF in the hematoma of 102 patients (122 hematomas) using the enzyme-linked immunosorbent assay technique. The relationship between the VEGF concentration in hematoma and the intrahematoma membranous structure confirmed by preoperative T(2)(*)-weighted magnetic resonance image was examined in 46 of these patients. VEGF and hypoxia-inducible factor-1alpha (HIF-1alpha) expression was immunohistochemically studied and microvessel density (MVD) in the outer membrane was identified using anti-CD31 antibody in 30 patients. VEGF and HIF-1alpha were positive in the outer membranes of all 30 patients. VEGF expression was significantly correlated to HIF-1alpha expression (r(s) = 0.651, p = 0.0084) and VEGF concentration in the hematoma (r(s) = 0.654, p = 0.0013). VEGF concentration in layered hematomas, which have intrahematoma membranous structure, was significantly higher than in non-layered hematomas (p < 0.01). Although MVDs of the outer membranes were comparable to those described in tumors, there was no significant relationship with VEGF expression. The present study suggests that VEGF in CSDH, which may be induced in the neomembrane by HIF-1 release, may give rise to the excessive development of fragile microvessels and hyperpermeability, resulting in the enlargement of CSDH.

Prolonged exposure to ammonia increases extracellular glutamate in cultured rat astrocytes.

Abnormal alteration of brain function is a characteristic complication of hepatic encephalopathy in both acute and chronic liver failure. Previous studies suggest that the pathogenesis of hepatic encephalopathy involves chronic glial edema with subsequent alteration of glioneuronal communication, N-methyl-d-aspartate (NMDA) receptor activation, and oxidative/nitrosative stress. In the present study, we investigated extracellular glutamate levels in cultured astrocytes under prolonged exposure to ammonia. Using an enzyme-linked high-performance liquid chromatography assay to detect glutamate, prolonged (48 h) exposure of cultured astrocytes to ammonia resulted in a concentration- and time-dependent increase in extracellular glutamate. Similar increases were observed when ammonia-containing medium (pH 7.8) was adjusted to the pH of control medium (pH 7.4), indicating that the effect is not due to pH. Treatment of astrocytes with an antioxidant (l-ascorbic acid), an NADPH oxidase inhibitor (apocynin), a Ca2+ chelator (BAPTA-AM), an NMDA receptor antagonist (NK801), or a mitochondrial permeability transition inhibitor (cyclosporine A) suppressed the increase of extracellular glutamate in response to prolonged ammonia exposure. Prolonged exposure to ammonia increased extracellular glutamate through the NMDA receptor, increased intracellular Ca2+ levels, and upregulation of excitatory amino acids. The addition of ATP further increased extracellular glutamate levels in astrocytes subjected to prolonged ammonia treatment (5mM, 48 h) in a dose-dependent manner. These results indicate that the deregulation of glutamate release from astrocytes may contribute to the dysfunction of glutamatergic neurons in patients with acute liver failure (ALF).

IGF2 modulates the microenvironment for osteoclastogenesis.

We previously reported that hypoxic stress enhanced osteoclast differentiation via increasing insulin-like growth factor 2 (IGF2) production. However, the mechanisms underlying IGF2 stimulation remains unknown. In this study, we investigated the molecular mechanisms of osteoclastogenesis by IGF2 treatment. Primary mouse bone marrow cells were cultured with IGF2. Total RNAs were applied to a DNA microarray analysis, and quantitative RT-PCR was then used to confirm the microarray data and clarify which cells expressed the relative genes. The most interesting findings were the upregulations of CXC chemokine ligand 7 (CXCL7) expression in stromal cells and stromal cell-derived factor 1 (SDF1) expression in osteoblastic cells with IGF2 treatment. The addition of exogenous SDF1 to CXCL7 increased the number of osteoclasts and promoted the formation of giant osteoclasts. These results suggest that IGF2 modulates the microenvironment around osteoclast precursor cells. SDF1 together with CXCL7 may promote the formation of giant osteoclasts.

Expression of myelencephalon-specific protease after cryogenic lesioning of the rat parietal cortex.

The gene for myelencephalon-specific protease (MSP) is a member of the kallikrein gene family and in rats is expressed mainly in the central nervous system. Its function and alteration in brain injury have not yet been clarified. We examined the expression of MSP after cryogenic injury (CI) using in situ hybridization, immunohistochemistry, and Western blotting. Analysis of MSP mRNA by in situ hybridization revealed a higher level of expression around the cryogenic area than on the contralateral side at 2-7 days after CI, with peak expression occurring 7 days after CI. Immunohistochemical analysis demonstrated expression of MSP protein at 1 day after CI, in the same region in which MSP mRNA was observed, with peak expression again at 7 days after CI, in the area around the lesion. Double immunohistochemical labeling revealed that MSP was expressed mainly in oligodendrocytes. These results suggest that expression of MSP may be related to the turnover of myelin-associated proteins and extracellular matrix proteins after CI. The regulation of active MSP may be important in the physiological or pathological changes involved in remyelination or demyelination.

Differential regulation of aquaporin-5 and -9 expression in astrocytes by protein kinase A.

Aquaporins (AQPs) transport water through the membranes of numerous tissues, but the molecular mechanisms for regulating water balance in brain are unknown. In this study, we investigated the effects of a protein kinase A (PKA) activator on the expression of AQP4, 5 and 9 in cultured rat astrocytes. Treatment of the cells with dbcAMP caused decreases in AQP5 mRNA and protein and increases in AQP9 mRNA and protein in time- and concentration-dependent manners. However, AQP4 mRNA and protein were not changed by treatment with dbcAMP. The dbcAMP-induced effects on AQP5 and AQP9 mRNAs were inhibited by PKA inhibitors. In addition, pretreating the cells with an inhibitor of protein synthesis, cycloheximide, inhibited the increase in AQP9 mRNA induced by dbcAMP, but not the decrease in AQP5 mRNA. These results suggest that signal transduction via PKA may play important roles in regulating the expression of AQP5 and AQP9, and the effect on AQP9 may be mediated by some factors induced by dbcAMP.

Developmental changes and localization of mouse brain serine proteinase mRNA and protein in mouse brain.

Serine proteases are known to be involved in neural development and various functions in the central nervous system. Mouse brain serine proteinase (mBSP) is expressed almost exclusively in the mouse brain and it has been characterized at the molecular and biochemical levels. In this study, we analyzed the developmental changes and localization of mBSP mRNA and protein in the mouse brain, using reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Expression of mBSP was strong in the white matter and the nerve tracts after postnatal day 30, especially in the cerebellum and the medulla oblongata. These results suggest that mBSP contributes to development and sustaining the functions in the mouse brain.