Simple Measurement System for Biological Signal Using a Smartphone

This paper describes simple measurement system for biological signal using smartphone. The proposed system consists of an instrumentation amplifier, a filter and an AC/DC converter. The biological signal is converted to the digital data through the microphone terminal with A/D converter in the smartphone. In many cases, the circuits require the power sources such as the cell batteries, however, the proposed system is supplied the power through the earphone terminal of the smartphone. Therefore, the proposed system no require the batteries. The software of this system parallelizes the processing so that the earphone output and the microphone terminal can be executed at the same time. The proposed system was verified through the measurement of surface electromyogram using discrete parts and iOS. Results of experimentation, the proposed system was operating correctly

New active diode with bulk regulation transistors and its application to integrated voltage rectifier circuit

This paper describes new active diode with bulk regulation transistors and its application to the integrated voltage rectifier circuit for a biological signal measurement system with smartphone. The conventional active diode with BRT has the dead region which causes leak current, and the output voltages of the application (e.g. voltage rectifier circuit) decrease. In order to overcome these problem, we propose new active diode with BRT which uses the control signal from the comparator of active diode to eliminate the dead region. Next we apply the proposed active diode with BRT to the integrated voltage rectifier circuit. The proposed active diode with BRT and voltage rectifier circuit were fabricated using 0.6 μm standard CMOS process. From experimental results, the proposed active diode with BRT eliminates the dead region perfectly, and the proposed voltage rectifier circuit generates + 2.86 V (positive side) and - 2.70 V (negative side) under the condition that the amplitude and frequency of the input sinusoidal signal are 1.5 V and 10 kHz, respectively, and the load resistance is 10 kΩ

National survey of catheter ablation for atrial fibrillation: The Japanese catheter ablation registry of atrial fibrillation (J-CARAF)

AbstractTo assess the current status of atrial fibrillation (AF) ablation in Japan, the Japanese Heart Rhythm Society (JHRS) instituted a national registry, the Japanese Catheter Ablation Registry of AF (J-CARAF).MethodsUsing an online questionnaire, the JHRS invited electrophysiology centers in Japan to voluntarily and retrospectively register data regarding the AF ablation procedures performed in September, 2011.ResultsA total of 128 centers submitted data regarding AF ablation procedures in 932 patients (age 62.1±10.4 years; male 76.8%; paroxysmal AF 65.7%, CHADS2 score 1.0±1.0). The majority received oral anticoagulant therapy during and following the procedure (68.9% and 97.5%, respectively). Pulmonary vein isolation (PVI) was performed in 97.5% of the patients; ipsilateral encircling PVI was the preferred technique (79.7%). Three-dimensional (3D) mapping systems and irrigated-tip catheters were used in 94.8% and 87.7% of the procedures, respectively. Ablation methods other than PVI were performed in 78.8% of all the patients and 73.5% of the patients with paroxysmal AF. Acute complications were reported in 6.2% of the patients, but no early deaths were recorded.ConclusionsIpsilateral encircling PVI, using 3D mapping and irrigated-tip catheters, is the standard AF ablation method in Japan. However, adjunctive ablations were performed frequently, even in patients with paroxysmal AF

Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy

Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy.BackgroundThe slit diaphragm plays a critical role in maintaining the barrier function of the glomerular capillary wall. The pathogenic mechanism of proteinuria in membranous nephropathy remains uncertain. This study was undertaken to analyze the pathogenic role of slit diaphragm in proteinuria in experimental membranous nephropathy.MethodsThe expression and the localization of slit diaphragm–associated molecules (nephrin, podocin, and CD2AP) and other podocyte-associated molecules (podocalyxin and α3 integrin) in passive and active Heymann nephritis were analyzed by immunofluorescence and Western blot analysis. The interaction of slit diaphragm–associated molecules was investigated by the dual-labeling immunofluorescence method. The mRNA expression of these molecules was also analyzed.ResultsShifts in nephrin and podocin staining patterns, from linear to granular, were detected in the early stages of passive Heymann nephritis. These shifts were not parallel, and the dissociation of these molecules was detected by the dual-labeling immunofluorescence method in passive and active Heymann nephritis. Western blot analyses with sequentially solubilized materials indicated that the nephrin-rich fraction changed from being partly detergent-resistant to being predominantly detergent-soluble. This change did not occur with podocin. Nephrin excreted into urine was already detected in the early stages of passive Heymann nephritis. Decreased mRNA expression of nephrin and podocin was observed before the onset of proteinuria. By contrast, no extensive change in the expression of α3 integrin was observed in this study.ConclusionNephrin is dissociated from podocin and excreted into urine in the early stages of Heymann nephritis. The reduced expression of nephrin and podocin, along with their dissociation, may contribute to the development of proteinuria in Heymann nephritis

Intestinal epithelial cell-derived IL-15 determines local maintenance and maturation of intraepithelial lymphocytes in the intestine

Interleukin-15 (IL-15) is a cytokine critical for maintenance of intestinal intraepithelial lymphocytes (IELs), especially CD8αα+ IELs (CD8αα IELs). In the intestine, IL-15 is produced by intestinal epithelial cells (IECs), blood vascular endothelial cells (BECs) and hematopoietic cells. However, the precise role of intestinal IL-15 on IELs is still unknown. To address the question, we generated two kinds of IL-15 conditional knockout (IL-15cKO) mice: villin-Cre (Vil-Cre) and Tie2-Cre IL-15cKO mice. IEC-derived IL-15 was specifically deleted in Vil-Cre IL-15cKO mice, whereas IL-15 produced by BECs and hematopoietic cells is deleted in Tie2-Cre IL-15cKO mice. The cell number and frequency of CD8αα IELs and NK IELs were significantly reduced in Vil-Cre IL-15cKO mice. By contrast, CD8αα IELs were unchanged in Tie2-Cre IL-15cKO mice, indicating that IL-15 produced by BECs and hematopoietic cells is dispensable for CD8αα IELs. Expression of an anti-apoptotic factor, Bcl-2, was decreased, whereas Fas expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. Forced expression of Bcl-2 by a Bcl-2 transgene partially restored CD8αα IELs in Vil-Cre IL-15cKO mice, suggesting that some IL-15 signal other than Bcl-2 is required for maintenance of CD8αα IELs. Furthermore, granzyme B production was reduced, whereas PD-1 expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. These results collectively suggested that IEC-derived IL-15 is essential for homeostasis of IELs by promoting their survival and functional maturation

Chronic Oral Infection with Porphyromonas gingivalis Accelerates Atheroma Formation by Shifting the Lipid Profile

BACKGROUND: Recent studies have suggested that periodontal disease increases the risk of atherothrombotic disease. Atherosclerosis has been characterized as a chronic inflammatory response to cholesterol deposition in the arteries. Although several studies have suggested that certain periodontopathic bacteria accelerate atherogenesis in apolipoprotein E-deficient mice, the mechanistic link between cholesterol accumulation and periodontal infection-induced inflammation is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We orally infected C57BL/6 and C57BL/6.KOR-Apoe(shl) (B6.Apoeshl) mice with Porphyromonas gingivalis, which is a representative periodontopathic bacterium, and evaluated atherogenesis, gene expression in the aorta and liver and systemic inflammatory and lipid profiles in the blood. Furthermore, the effect of lipopolysaccharide (LPS) from P. gingivalis on cholesterol transport and the related gene expression was examined in peritoneal macrophages. Alveolar bone resorption and elevation of systemic inflammatory responses were induced in both strains. Despite early changes in the expression of key genes involved in cholesterol turnover, such as liver X receptor and ATP-binding cassette A1, serum lipid profiles did not change with short-term infection. Long-term infection was associated with a reduction in serum high-density lipoprotein (HDL) cholesterol but not with the development of atherosclerotic lesions in wild-type mice. In B6.Apoeshl mice, long-term infection resulted in the elevation of very low-density lipoprotein (VLDL), LDL and total cholesterols in addition to the reduction of HDL cholesterol. This shift in the lipid profile was concomitant with a significant increase in atherosclerotic lesions. Stimulation with P. gingivalis LPS induced the change of cholesterol transport via targeting the expression of LDL receptor-related genes and resulted in the disturbance of regulatory mechanisms of the cholesterol level in macrophages. CONCLUSIONS/SIGNIFICANCE: Periodontal infection itself does not cause atherosclerosis, but it accelerates it by inducing systemic inflammation and deteriorating lipid metabolism, particularly when underlying hyperlidemia or susceptibility to hyperlipidemia exists, and it may contribute to the development of coronary heart disease

Achieving LDL cholesterol target levels <1.81 mmol/L may provide extra cardiovascular protection in patients at high risk: Exploratory analysis of the Standard Versus Intensive Statin Therapy for Patients with Hypercholesterolaemia and Diabetic Retinopathy study

Aims To assess the benefits of intensive statin therapy on reducing cardiovascular (CV) events in patients with type 2 diabetes complicated with hyperlipidaemia and retinopathy in a primary prevention setting in Japan. In the intension-to-treat population, intensive therapy [targeting LDL cholesterol = 2.59 to = 100 to = 2.59 to <3.10 mmol/L in patients with hypercholesterolaemia and diabetic retinopathy