Growth failure starts from early infancy in children with short stature at age 6

We compared the growth of 183 children with short stature (≤ 2SD) and 73 children of normal height at age six who were visiting the Tanaka Growth Clinic. We classified these short children as suffering from either idiopathic short stature (ISS, n = 119), GH deficiency (GHD, n = 33) or small-for-gestational-age short stature (SGASS, n = 31) on the basis of subsequent test results and other factors. We also conducted a retrospective study of changes in their height, wt and nutritional intake over time. The mean changes in height SD score from birth to 6 yr were –0.24 SD in normal height children with a normal birth length and +2.27 SD in normal height children with a low birth length. In short children, these changes were –1.93 SD for children with ISS, –2.41 SD for those with GHD and +0.58 for those with SGASS. The mean changes from birth to 6 mo were –0.84 SD, −1.03 SD and +0.38 SD in children with ISS, GHD and SGASS, respectively. The mean change in height SD score from birth to age 1 yr was –1.07 SD, –1.44 SD and +0.35 SD, respectively. The decrease in height SD score from birth to 6 mo accounted for 43.5% of the decrease in height SD score from birth to 6 yr in children with ISS and it accounted for 42.6% of the decrease in children with GHD. Only 19% of short children bottle-fed well, and 53% fed poorly, as opposed to 56% and 16% of normal height children who fed well and poorly, respectively. Post weaning, only 22% of short children ate well, and 56% fed poorly, as opposed to 53% and 17% of normal height children who fed well and poorly, respectively. These findings demonstrated that growth failure started from early infancy in ISS and GHD children. It was suggested that poor nutritional intake in infancy and early childhood was a partial cause of short stature at age 6.     

The role of Ca2+ release from sarcoplasmic reticulum in the regulation of sinoatrial node automaticity

Summary The role of Ca²⁺ release channels in the sarcoplasmic reticulum in modulating physiological automaticity of the sinoatrial (SA) node was studied by recording transmembrane action potentials and membrane ionic currents in small preparations of the rabbit SA node. Ryanodine, which modifies the conductance and gating behavior of the Ca²⁺ release channels, was used to block Ca²⁺ release from the sarcoplasmic reticulum. Superfusion of 1-mM ryanodine decreased the spontaneous firing frequency as well as the maximal rate of depolarization of the SA, and these reductions reached a steady state within approximately 5min. The action potential recordings revealed that the latter part of diastolic depolarization was depressed and that the take-off potential became less negative. This suggested that the negative chronotropic effect of ryanodine resulted from the blockade of physiological Ca²⁺ release from the sarcoplasmic reticulum. In voltage clamp experiments, using double-microelectrode techniques, ryanodine did not markedly reduce the Ca²⁺ current (I_Ca) but decreased the delayed rectifying K+ current (I_K), the steady-state inward current (I_ss), and the hyperpolarization-activated inward current (I_h). These observations suggest that, even when the function of Ca²⁺ channels in the cell membrane is normally maintained, depression of Ca²⁺ release channels in the sarcoplasmic reticulum would prevent sufficient elevation of the Ca²⁺ concentration in SA node cells for the activation of various ionic currents, and, thus adversely affect the physiological automaticity of this primary cardiac pacemaker.     

Hepatocellular carcinoma: a case of extrahepatic seeding after percutaneous radiofrequency ablation using an expandable needle electrode

A 2.5-cm diameter, exophytic seeding of hepatocellular carcinoma was detected by contrast-enhanced computed tomography in a 76-year-old man. He had previously undergone a radiofrequency ablation therapy with an expandable, ten-hook needle electrode for the treatment of a 1.5-cm hepatocellular carcinoma in liver segment VI. Ultrasound-guided fine needle biopsy revealed that this hepatocellular carcinoma was moderately differentiated, as initial tumor was. An additional radiofrequency ablation achieved complete ablation of this neoplastic mass on contrast-enhanced computed tomography scanning. Recurrences were not found for eight months after. To prevent tumor seeding, using thermocoagulation when retracting the needle electrode may be useful.     

Adiponectin induces insulin secretion in vitro and in vivo at a low glucose concentration

Aims/hypothesis A decrease in plasma adiponectin levels has been shown to contribute to the development of diabetes. However, it remains uncertain whether adiponectin plays a role in the regulation of insulin secretion. In this study, we investigated whether adiponectin may be involved in the regulation of insulin secretion in vivo and in vitro. Methods The effect of adiponectin on insulin secretion was measured in vitro and in vivo, along with the effects of adiponectin on ATP generation, membrane potentials, Ca²⁺ currents, cytosolic calcium concentration and state of 5′-AMP-activated protein kinase (AMPK). In addition, insulin granule transport was measured by membrane capacitance and total internal reflection fluorescence (TIRF) analysis. Results Adiponectin significantly stimulated insulin secretion from pancreatic islets to approximately 2.3-fold the baseline value in the presence of a glucose concentration of 5.6 mmol/l. Although adiponectin had no effect on ATP generation, membrane potentials, Ca²⁺ currents, cytosolic calcium concentrations or activation status of AMPK, it caused a significant increase of membrane capacitance to approximately 2.3-fold the baseline value. TIRF analysis revealed that adiponectin induced a significant increase in the number of fusion events in mouse pancreatic beta cells under 5.6 mmol/l glucose loading, without affecting the status of previously docked granules. Moreover, intravenous injection of adiponectin significantly increased insulin secretion to approximately 1.6-fold of baseline in C57BL/6 mice. Conclusions/interpretation The above results indicate that adiponectin induces insulin secretion in vitro and in vivo. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users. M. Okamoto and M. Ohara-Imaizumi contributed equally to this study.     

Effect of glycemic state on postprandial hyperlipidemia and hyperinsulinemia in patients with coronary artery disease

Both postprandial hyperlipidemia and hyperinsulinemia have been thought to play an important role in the development of atherosclerosis, and to be a potent risk factor for cardiovascular event. To examine effects of glycemic state on postprandial hyperlipidemia and hyperinsulinemia in patients with coronary artery disease (CAD), a total of 112 consecutive male patients with angiographically confirmed CAD were loaded with a high-fat and high-glucose test meal. CAD patients were divided into three groups as “non-diabetic”, “prediabetic”, and “diabetic” CAD groups. The serum triglyceride (TG) and remnant-like particle cholesterol (RLP-C) levels at the 6th hour in diabetic CAD group showed significantly higher than non-diabetic CAD group, and the incremental area under the curves (iAUCs) of these levels in diabetic CAD group were significantly greater than non-diabetic CAD group (TG, P = 0.0194; RLP-C, P = 0.0219). There were no significant differences in the iAUCs of TG or RLP-C between prediabetic and non-diabetic CAD group. The AUCs of plasma insulin levels or insulin resistance index (IRI): (AUCs of insulin) × (AUCs of glucose) as the insulin resistance marker were greater in diabetic CAD group than non-diabetic CAD group (insulin, P = 0.0373; IRI, P = 0.0228). The AUCs of serum TG or RLP-C levels showed a correlation with the AUCs of plasma insulin (AUC-TG, r = 0.5437, P < 0.0001; AUC-RLP-C, r = 0.6847, P < 0.0001), and they correlated well with the insulin resistance index (AUC-TG, r = 0.7724, P < 0.0001; AUC-RLP-C, r = 0.7645, P < 0.0001). We found that the insulin resistance showed a close relationship with postprandial hyperlipidemia in CAD patients. Diabetic, but not prediabetic state, may be a risk for postprandial impaired lipid metabolism in CAD patients.