Algorithm for the classification of multi-modulating signals on the electrocardiogram

This article discusses the algorithm to measure electrocardiogram (ECG) and respiration simultaneously and to have the diagnostic potentiality for sleep apnoea from ECG recordings. The algorithm is composed by the combination with the three particular scale transform of a(j)(t), u(j)(t), o(j)(a(j)) and the statistical Fourier transform (SFT). Time and magnitude scale transforms of a(j)(t), u(j)(t) change the source into the periodic signal and τ(j) = o(j)(a(j)) confines its harmonics into a few instantaneous components at τ(j) being a common instant on two scales between t and τ(j). As a result, the multi-modulating source is decomposed by the SFT and is reconstructed into ECG, respiration and the other signals by inverse transform. The algorithm is expected to get the partial ventilation and the heart rate variability from scale transforms among a(j)(t), a(j+1)(t) and u(j+1)(t) joining with each modulation. The algorithm has a high potentiality of the clinical checkup for the diagnosis of sleep apnoea from ECG recordings

Usefulness of continuous blood glucose monitoring and control for patients undergoing liver transplantation

Background : The purpose of this study was to evaluate the usefulness of the closed-loop system (STG-22 ; Nikkiso, Tokyo, Japan), a type of artificial endocrine pancreas for the continuous monitoring and control of intraoperative blood glucose in patients undergoing liver transplantation. Methods : Sixteen patients undergoing livingdonor liver transplantation were enrolled in this study. Glucose levels were controlled with either a manual injection of insulin based on a commonly used sliding scale (manual insulin group, n=8) or a programmed infusion of insulin determined by the control algorithm of the artificial endocrine pancreas (programmed insulin group, n=8). The target glucose level range was set at 80-150 mg/dl. Results : The mean and SD of blood glucose concentration during surgery (Glu-Ave and Glu-SD, respectively) for the programmed insulin group were lower than for the manual insulin group. The coefficient of variability (Glu-CV=Glu-SD×100 /Glu-Ave) for the programmed insulin group was also lower than for the manual insulin group (20.1±4.9% vs. 26.9±6.1% ; mean±SD). No hypoglycemia was detected in either group. Conclusion : The STG-22 closed-loop system is effective for maintaining strict blood glucose control during liver transplantation with minimal variability in blood glucose concentration

Impact of newly developed, next-generation artificial endocrine pancreas

Background : Recent studies have shown that strict perioperative blood glucose management may reduce mortality and morbidity in critically ill adult patients. The purpose of this study was to assess the accuracy and efficacy of the intraoperative application of a newly developed, next-generation artificial endocrine pancreas (STG-55, Nikkiso Co., Ltd., Tokyo, Japan). Methods : Twenty patients scheduled to undergo surgery were enrolled in this study. The STG-55 is designed to be more user-friendly than its conventional counterpart (STG-22) while maintaining the latter’s fundamental functions, such as a closed-loop system using algorithms for insulin and glucose infusion. After anesthetic induction, a 20G intravenous catheter was inserted into a peripheral forearm vein and connected to a continuous blood glucose monitor. The resultant 105 scores for paired blood glucose values were compared by Bland-Altman analysis. Results : Stable blood glucose values were maintained automatically, and there were no complications related to use of the STG-55. A close correlation (r=0.96) was observed between continuous glucose measurements using the STG-55 and conventional intermittent glucose measurements. The difficulty of manipulation using this system was decreased by improved preparation procedures. Conclusion : The glycemic control system using the STG-55 could provide an alternative way to achieve effective and safe perioperative glycemic control

Usefulness of artificial endocrine pancreas during resection of insulinoma

A 71-year-old woman had an episode of syncope due to hypoglycemia of 27 mg/dl. She was diagnosed with insulinoma and scheduled for laparoscopic enucleation along with the use of an artificial endocrine pancreas (STG-22, Nikkiso Co., Ltd., Tokyo, Japan). Anesthesia was maintained with sevoflurane and remifentanil. Her blood glucose level was controlled using the artificial endocrine pancreas, which enabled continuous blood glucose monitoring and computer-operated glucose and insulin infusion to maintain the blood glucose level at a steady state. The target concentration of blood glucose was set at 80-120 mg/dl during surgery. Until removal of the tumor, the blood glucose level was kept at around 80-100 mg/dl. After removal of the tumor, the blood glucose level gradually increased, but it was kept in the normal range by the artificial endocrine pancreas. The artificial endocrine pancreas was useful to monitor and maintain blood glucose levels during and after the removal of insulinoma, without any hyper- or hypoglycemia

Membrane depolarization-induced contraction of rat caudal arterial smooth muscle involves Rho-associated kinase.

Depolarization of the sarcolemma of smooth muscle cells activates voltage-gated Ca2+ channels, influx of Ca2+ and activation of cross-bridge cycling by phosphorylation of myosin catalysed by Ca2+/calmodulin-dependent myosin light-chain kinase (MLCK). Agonist stimulation of smooth muscle contraction often involves other kinases in addition to MLCK. In the present study, we address the hypothesis that membrane depolarization-induced contraction of rat caudal arterial smooth muscle may involve activation of Rho-associated kinase (ROK). Addition of 60 mM K+ to de-endothelialized muscle strips in the presence of prazosin and propranolol induced a contraction that peaked rapidly and then declined to a steady level of force corresponding to approx. 30% of the peak contraction. This contractile response was abolished by the Ca2+-channel blocker nicardipine or the removal of extracellular Ca2+. An MLCK inhibitor (ML-9) inhibited both the phasic and tonic components of K+-induced contraction. On the other hand, the ROK inhibitors Y-27632 and HA-1077 abolished the tonic component of K+-induced contraction, and slightly reduced the phasic component. Phosphorylation levels of the 20-kDa light chain of myosin increased rapidly in response to 60 mM K+ and subsequently declined to a steady-state level significantly greater than the resting level. Y-27632 abolished the sustained and reduced the phasic elevation of the phosphorylation of the 20-kDa light chain of myosin, without affecting the K+-induced elevation of cytosolic free Ca2+ concentration. These results indicate that ROK activation plays an important role in the sustained phase of K+-induced contraction of rat caudal arterial smooth muscle, but has little involvement in the phasic component of K+-induced contraction. Furthermore, these results are consistent with inhibition of myosin light-chain phosphatase by ROK, which would account for the sustained elevation of myosin phosphorylation and tension in response to membrane depolarization

Isolation of deuterated histones from yeast grown on media dissolved in 2H2O

AbstractWe have succeeded in growing Saccharomyces cerevisiae (baker's yeast) on media containing 2H2O and isolating the core histones highly deuterated in the non-exchangeable positions. The deuterated histones obtained here are of great value for their possible widespread use for structural studies of chromatin

Inhibition of Ectopic Arginine Vasopressin Production by Phenytoin in the Small Cell Lung Cancer Cell Line Lu-165

Phenytoin, a voltage-gated sodium channel (NaV channel) antagonist, reportedly inhibits arginine vasopressin (AVP) release from an isolated rat neurohypophysis. So far, it is uncertain whether phenytoin has a direct action on ectopic AVP-producing neuroendocrine tumors. We studied the effect of phenytoin on the release of copeptin, the C-terminal fragment of pro-AVP, and expression of AVP gene in the human small cell lung cancer cell line Lu-165. Cells were maintained in RPMI1640 medium with 10% fetal bovine serum and were used within the fifth passage. Copeptin was detected using a new sandwich immunoassay, and AVP mRNA levels were measured using real-time reverse transcription polymerase chain reaction. Treatment with phenytoin at a concentration of 25 µg/mL, but not at 5 or 10 µg/mL, had an inhibitory effect on copeptin levels in the medium at 48 h. At the same concentration, AVP mRNA levels in Lu-165 cells also decreased. Although a sodium challenge with added sodium at 20 mEq/L increased copeptin levels in the medium, a sodium challenge with added sodium at 10 and 20 mEq/L had no effect on AVP mRNA levels. Phenytoin at a concentration of 25 µg/mL suppressed copeptin levels in the medium under the sodium challenge with added sodium at 10 and 20 mEq/L. Phenytoin at a concentration of 25 µg/mL also decreased AVP mRNA levels in Lu-165 cells under the sodium challenge with added sodium at 10 mEq/L, but not at 20 mEq/L. Among five tested NaV channel subunits, NaV1.3 was highly expressed in Lu-165 cells. However, phenytoin significantly decreased NaV1.3 mRNA levels under the sodium challenge with added sodium at 10 and 20 mEq/L. These results suggest that Lu-165 cells are sensitive to phenytoin and sodium to control of AVP release and its gene expression. Phenytoin might have a direct action on ectopic AVP-producing tumors, suggesting the importance of NaV channels in AVP-producing neuroendocrine tumors