Hideyuki Okada

Effect of royal jelly ingestion for six months on healthy volunteers

BackgroundRoyal jelly is a widely ingested supplement for health, but its effects on humans are not well known. The objective was to evaluate the effects of long-term royal jelly ingestion on humans.MethodsWe conducted a randomized placebo-controlled, double-blind trial. A total of 61 healthy volunteers aged 42-83 years were enrolled and were randomly divided into a royal jelly group (n = 31) and a control group (n = 30). Three thousand mg of royal jelly (RJ) or a placebo in 100 ml liquid/day were ingested for 6 months. The primary outcomes were changes in anthropometric measurements and biochemical indexes from baseline to 6 months after intervention.ResultsThirty subjects in the RJ group and 26 in the control group were included in the analysis of endpoints. In an adjusted mean change of the variables from the baseline, significant differences between the two groups could be found in red blood cell counts (+0.16x106 /μL for the RJ group vs. -0.01x106 /μL for the control group, P = 0.0134), hematocrit (+0.9% vs. -0.8%, P = 0.0251), log (fasting plasma glucose) (+0.01 ± 0.01 log mg/dL vs. +0.05 ± 0.01 log mg/dL, P = 0.0297), log (insulinogenic index) (+0.25 vs. -0.13, P = 0.0319), log dehydroepiandrosterone sulfate (DHEA-S) (+0.08 log μg/dL vs. +0.20 log μg/dL, P = 0.0483), log testosterone (T) (+0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL, P = 0.0416), log T/DHEA-S ratio (+0.05 ± 0.05 vs. -0.23 ± 0.59, P = 0.0015), and in one of the SF-36 subscale scores, mental health (MH) (+4 vs. -7, P = 0.0276).ConclusionsSix-month ingestion of RJ in humans improved erythropoiesis, glucose tolerance and mental health. Acceleration of conversion from DHEA-S to T by RJ may have been observed among these favorable effects.

Elevated mitochondrial biogenesis in skeletal muscle is associated with testosterone-induced body weight loss in male mice

Androgen reduces fat mass, although the underlying mechanisms are unknown. Here, we examined the effect of testosterone on heat production and mitochondrial biogenesis. Testosterone‐treated mice exhibited elevated heat production. Treatment with testosterone increased the expression level of peroxisome proliferator‐activated receptor‐γ coactivator‐1α (PGC1α), ATP5B and Cox4 in skeletal muscle, but not that in brown adipose tissue and liver. mRNA levels of genes involved in mitochondrial biogenesis were elevated in skeletal muscle isolated from testosterone‐treated male mice, but were down‐regulated in androgen receptor deficient mice. These results demonstrated that the testosterone‐induced increase in energy expenditure is derived from elevated mitochondrial biogenesis in skeletal muscle.

TAFRO syndrome: 2 cases and review of the literature

Recently, more than ten cases of thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome or Castleman–Kojima disease exhibiting such symptoms as thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly have been reported in Japan. We have found two cases of TAFRO syndrome and have reviewed another eighteen previously reported cases. Histological findings of the lymph nodes and levels of interleukin 6 (IL-6) and vascular endothelial growth factor in both serum/plasma and effusions are important characteristics for diagnosing this syndrome.

Effects of phorbol ester‐sensitive PKC (c/nPKC) activation on the production of adiponectin in 3T3‐L1 adipocytes

PPARγ plays a key role in adipocyte specific gene expression. In this study, we assessed the effects of phorbol ester (TPA)‐sensitive PKC (c/nPKC) activation on the expression of adipocyte specific genes and inflammation related genes. Treatment with both TPA and TNFα decreased mRNA levels of PPARγ, aP2, LPL and adiponectin. TNFα, but not TPA, increased IL‐6 and MCP‐1 mRNA levels, Next, we investigated the effects of ligands which activate c/nPKC. Insulin and angiotensin II (AII), but not high glucose, reduced PPARγ, aP2 and adiponectin mRNA levels. AII‐induced suppression of these genes was restored in the presence of Go6976, a specific c/nPKC inhibitor, and candesartan, an AII receptor blocker. The effect of reduced insulin was prevented by Go6976 and LY294002, a specific PI 3‐kinase inhibitors. Our results indicate that activation of c/nPKC could debilitate and/or might deteriorate insulin sensitivity in vivo, through the reduction of PPARγ and adiponectin expression in adipocyte.

Development and validation of a scoring system for prediction of insulin requirement for optimal control of blood glucose during glucocorticoid treatments

AIMS We have developed and validated a novel scoring system to predict insulin requirement for optimal control of blood glucose during glucocorticoid (GC) treatments, by retrospective analyses of clinical parameters before GC treatment. METHODS Three hundred-three adults (the Developing set) undergoing their first treatment of prednisolone (PSL) were divided into two groups, depending on treatment with or without insulin. Independent risk factors for insulin requirement were identified by a stepwise logistic regression analysis after univariate analyses between the two groups. We constructed a point-addition scoring system consisting of several categories and their coefficients in each risk factor derived from another logistic regression analysis. We validated it to two validation sets, A and B. RESULTS Male, higher levels of fasting plasma glucose (FPG), HbA1c, and serum creatinine (CRE) and a higher initial dose of PSL were identified as the risk factors. The sensitivity, specificity, and accuracy were 90.0%, 88.1%, and 88.4%; 87.5%, 66.7%, and 70.5%; 83.3%, 76.1%, and 76.6% in the Developing set, Validation set A, and Validation set B, respectively, when the scoring system was applied. CONCLUSIONS The scoring system is a valid and reliable tool to predict insulin requirements in advance during GC treatment.

Effect of Dehydroepiandrosterone on Insulin Sensitivity and Adipocyte Growth in Otsuka Long-Evans Tokushima-Fatty Rats

Dehydroepiandrosterone (DHEA) (1) is the major adrenal androgen of young adults. However, serum concentration of DHEA in 60 yearold men shows a gradual decrease, when compared with young men aged 25-30 years old. This decrease occurs as the incidence of atherosclerosis (2), obesity (3), and diabetes increases (4), suggesting that administration of DHEA may protect against the development of these disorders. Previously, we reported that in vitro DHEA treatment increased glucose uptake and activation of PI 3-kinase in native rat adipocytes (5). Protein kinase C (PKC) is a family of serine/threonine kinases, which play key functions in cellular signal transduction. Three categories of PKC, conventional, novel, and atypical PKCs, have been described depending on their mechanisms of activation. Moreover, it is known that 3-phosphoinositide-dependent protein kinase-1 (PDK1) is the hub of many signaling pathways, which phosphorylate many downstream kinases of phosphatidylinositol 3-kinase (PI 3-kinase), such as Akt kinase, S6 kinase and PKC. Previous studies suggested that atypical PKC (aPKC/) isoforms are required for insulin stimulation of glucose uptake (6), and PDK1 is necessary for activation of aPKCs (7). It has been reported that DHEA treatment reduces fat accumulation and protects against insulin resistance via an increase in PI 3-kinase after immunoprecipitation with insulin receptor substrate-1 (IRS-1) in male rats (8). We have investigated the in-vitro and in-vivo effects of DHEA on insulin-induced glucose uptake in adipocytes of Otsuka Log-Evans Tokushima fatty (OLETF) (9) and LETO rats. Moreover, we have shown the DHEA-induced glucose uptake by activation of PI 3-kinase/atypaical PKC siganlling without association with IRS-1 (10). In vivo treatment with DHEA affects on a decrease of adipose tissue via downregulation of peroxisome proliferator-activated receptor  (PPAR) expression (11). Based on above results, we have searched more precise mechanism of DHEA-induced amelioration of insulin sensitivity and clinical application of DHEA in diabetic animal models and human male adults.