n 1992, Brugada et al described 8 cases of aborted sudden death in patients without demonstrable structural heart disease, but with a peculiar electrocardiogram (ECG) pattern consisting of right bundle-branch block (RBBB) and ST-segment elevation in leads V1 to V3. 1 Three of 8 patients in this report were children, and familial occurrence was recognized. Since then, a few case reports have been published on this syndrome in young populations. [2][3][4] Brugada syndrome may cause sudden death in children, even in the first few months of life where it may be misdiagnosed as sudden infant death syndrome. The Brugada-type ECG is not rare in the adult Japanese population (0.14 to 0.70%). [5][6][7] However, the prevalence of this type of ECG in schoolchildren remains unclear. We evaluated the prevalence of Brugada-type ECG, incomplete RBBB (IRBBB) and complete RBBB (CRBBB) in Japanese schoolchildren stratified according to age. Circulation Journal Vol.68, April 2004 Methods ECG DefinitionsAll ECGs were recorded at standard gain (1 mV/10 mm) and paper speed (25 mm/s). An ECG was considered to be Brugada-type when the 12-lead ECG fully met the criteria for the Brugada syndrome as recently published in a consensus report. 8 To compare the prevalence with previous reports of healthy populations, we defined "Brugada-like" ECG as follows. The 12-lead ECG showed RBBB (rsR' or Rsr' pattern in V1 lead) and ST-segment elevation in the right precordial leads. The ST-segment elevation was defined as an elevation of the J point of ≥0.1 mV in leads V1 through V3. According to the configuration, ST-segment elevations were designated as either coved or saddle-back.Complete RBBB was defined as a QRS duration ≥0.12 s, with an RsR' configuration and IRBBB was defined as a QRS duration <0.12 s, with an rSr' configuration in the right precordial leads.The ECG records of all study subjects were reviewed by Yamakawa, without any information about the subjects including age, sex, or family history of sudden death. Ishikawa and Sumita reviewed those records on which judgments had been made, and they concurred with the judgments. Study SubjectsThe study population consisted of 20,387 young We considered right bundle-branch block and ST-segment elevation of the J point of ≥0.1 mV in leads V1 through V3 as Brugada-like ECG, and an ECG was considered to be Brugada-type when the 12-lead ECG fully meet the criteria for the Brugada syndrome as recently published in a consensus report. Only 2 children (0.0098%, 95% confidence interval (CI): 0 to 0.023%) completely conformed to the criteria for Brugada-type ECG. Brugada-like ECG was found in 11 (10 male) of 20,387 children (0.054%, 95% CI: 0.022 to 0.086%). The prevalence in males was significantly higher than that in females, even in children (0.096% vs 0.010%, p=0.012). Stratified according to age, there was tendency for the prevalence of Brugada-like ECG to increase up to puberty (first graders, 0.01%; fourth graders, 0.05%; seventh graders, 0.08%; tenth graders, 0.23%; p=0.068). ConclusionThe pre...
Adipose tissue contains multipotent cells known as adipose-derived stem/stromal cells (ASCs), which have therapeutic potential for various diseases. Although the demand for adipose tissue for research use remains high, no adipose tissue bank exists. In this study, we attempted to isolate ASCs from cryopreserved adipose tissue with the aim of developing a banking system. ASCs were isolated from fresh and cryopreserved adipose tissue of rats and compared for proliferation (doubling time), differentiation capability (adipocytes), and cytokine (hepatocyte growth factor and vascular endothelial growth factor) secretion. Finally, ASCs (2.5 × 106) were intravenously infused into rats with spinal cord injury, after which hindlimb motor function was evaluated. Isolation and culture of ASCs from cryopreserved adipose tissue were possible, and their characteristics were not significantly different from those of fresh tissue. Transplantation of ASCs derived from cryopreserved tissue significantly promoted restoration of hindlimb movement function in injured model rats. These results indicate that cryopreservation of adipose tissue may be an option for clinical application.
Studies on the relationships of brain weight to body weight during development were conducted in 218 mice, and revealed three distinct phases. During the first phase, the ratios are relatively constant. The second phase of short duration is characterized by abrupt reductions. In the third phase, which is the most enduring, the ratios again assume more constant values. The abrupt change in the ratios took place around 14 days of age. It is suggested that the abrupt change in the ratio is, in general, an indicator of the maturation of the brain, because there are several other parameters which approach mature levels around the 15th day. A review of the data on other species supports this suggestion.
[1] Strombolian eruptions are considered to be a consequence of the bursting of a large bubble. In order to understand the relation between the style of bubble bursting and the resulting airwave, we perform experiments of bubble bursting at the top of the surface of viscous liquid contained in an acrylic pipe which acts as an air column and observe it visually and acoustically. We find that when the liquid viscosity is less than 1 Pa s, the bubble vibrates before bursting. The major source of the airwave during the sequence of the bubble bursting is the bubble vibration. On the other hand, when the liquid viscosity is greater than 1 Pa s, the bubble does not vibrate. During bubble bursting, an aperture appears on the bubble film. The aperture growth first accelerates and later decelerates before finally stopping. The major source of the airwave is the aperture growth. We calculate a synthetic waveform of the airwave generated by the aperture growth which explains the experimentally observed airwave well. When the frequency of the airwave generated by the aperture growth matches the eigenfrequency of the air column, resonance occurs. Applying this model to the Strombolian eruption, the characteristic low frequency (<20 Hz) is explained if the velocity of the aperture growth is several meters per second. The model also explains the asymmetrical initial rise of the airwave observed in the Strombolian eruptions as a result of the accelerating growth of the aperture.Citation: Kobayashi, T., A. Namiki, and I. Sumita (2010), Excitation of airwaves caused by bubble bursting in a cylindrical conduit: Experiments and a model,
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