[Signal-averaged body-surface electrocardiography: clinical cardiac electrophysiological tests].
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Animals↗
Biomedical subjects
T Katoh
Publications and source records attributed to T Katoh.
[The electrocardiographic signal of the initial potential detected by signal averaged electrocardiogram].
Non invasive recording of late potential (LP) by signal-averaged electrocardiogram (SAE) is useful in predicting ventricular tachycardia (VT) especially in patients with myocardial infarction (MI). However, the rate of positive LP is not high enough to get clinical significance in anterior or anteroseptal MI, since the LP has been masked by QRS complex. The purpose of the present study is, to evaluate the clinical significance of the initial delay in patients with MI. 80 patients of MI were divided into four groups: AS (anteroseptal, n = 18, including 6 VT), A: (anterior, n = 22.7 VT), I: (inferior, n = 28.9 VT) and P: (posterior, n = 12, no VT). 20 non-MI patients were used for normal control (N). NEC7T18 was used to record SAE and each 5 msec integral values of filtered QRS complex from the initial upstroke to 60 msec point was measured. Integral values of AS and A were significantly lower than that of group I, P, and N. In patients with VT, AS shows more delay than A. In addition, AS with VT shows lower integral value than AS without VT, however no differences were observed between A with VT and without VT. We conclude that slow upstroke of signal-averaged QRS complex was mainly observed in patients of anteroseptal MI with VT, suggesting the initial conduction delay at ventricular septum may play an important role in the mechanism of VT.
Body Surface Potential Mapping↗
[Non-invasive evaluation of the concealed anterograde Kent conduction in concealed WPW syndrome].
The diagnosis of concealed WPW syndrome (C-WPW) has only been made when a retrograde conduction through Kent bundle was confirmed during electrophysiological study (EPS). However, recent EPS suggested the concealed anterograde conduction through Kent bundle (CACK) during programmed electrical stimulation in C-WPW. If we could non-invasively detect an evidence of CACK during sinus rhythm (SR), it is very useful in making differential diagnosis in patients who complain paroxysms of tachycardia. High resolution ECG using signal averaging technique was recorded in 142 patients. 22 C-WPW (C), 20 AV nodal reentrant tachycardia (A), both diagnosed by EPS and 100 control subjects (N) who have no evidence of pre-excitation and no tachycardia episodes were compared. The duration of high frequency micropotentials which preceded further to the earliest upstroke of QRS complex of surface ECG (PPD) were measured. Results; (1) PPD was zero in most of N. (2) The mean PPDs were 0.97 +/- 2.08 msec (range: -4-8) in N, 1.55 +/- 2.50 msec (0-8) inA and 7.86 +/- 3.99 msec (0-19) in C, respectively (p < 0.001, C:N, C:A). (3) The rates of positive early potential, defined as 6 msec or more PPD; mean + 2SD of N, were 5/100 (5%) in N, 3/20 (15%) in A and 17/22 (77.3%) in C, respectively (p < 0.001, C:N, C:A). (4) In some of C, who showed long PPD, CACK was documented during EPS. The presence of high frequency micropotentials in C suggests that CACK may exist and produced small amounts of pre-excitation even during SR.(ABSTRACT TRUNCATED AT 250 WORDS)
Body Surface Potential Mapping↗
[Clinical analysis of the surgical therapy of DeBakey type I acute aortic dissection].
We investigated relation of operative mortality with factors such as during from onset to operation, cardiac tamponade, age (more than 70 years old), aortic regurgitation, and shock. Fourteen patients underwent emergent surgery for DeBakey type I acute aortic dissection. These patients were the basis for this reports. Operative mortality was 43% (6/14). Although not statistically significant, there was a trend toward preoperative cardiac tamponade, namely the patients with preoperative tamponade had a poor prognosis. Causes of death were as follows, two patients related to the residual false lumen, two patients to surgical procedure, one patients to ischemic heart and one to mis-swallowing after operation. Among two patients who related to the residual false lumen, one died of rupture of the descending aorta that the clamping was performed during operation and the other occlusion of superior mesenteric artery 43 days after operation. Causes of deaths in patients in relation with surgical procedure were brain death and postoperative bleeding in 1 each. We concluded that the residual false lumen is a risk factor in the peri-operative stage.
Adult↗
[Marked dilatation of the bilateral common carotid artery: a case report].
We reported a rare case of marked dilatation of the bilateral common carotid artery (CCA) associated with stenosis of the left middle cerebral artery (MCA). A 64-year-old female was admitted with right hemiparesis and dysarthria. She was hospitalized 2 years ago for cholecystitis. For 5 years, she has been under medical treatment for hypertension, diabetes mellitus, hyperlipidemia, cardiac failure associated with hypertrophic cardiomyopathy, and atrial fibrillation. Brain CT scan showed infarction of the left corona radiata. Angiography revealed marked dilatation of the bilateral CCA and the internal carotid artery (ICA), moderate dilatation of the innominate artery and the right subclavian artery, kinking of the right CCA, diverticular outpouching of the left ICA, and stenosis of the right external carotid artery and the left MCA. Breast CT scan revealed moderate dilatation and marked calcification of the ascending aorta and the aortic arch. Laboratory examination did not show any sign of inflammation, rheumatoid factor (RA), antistreptolysis-O (ASLO) and antinucleotic antibody. Based on the clinical course, radiological findings and laboratory data, possible diagnosis of the dilatation of the bilateral CCA was discussed with particular emphasis on arteriosclerotic aneurysm and aortitis syndrome.
Aortic Arch Syndromes↗
[Clinical significance of abnormal high signal intensity of left ventricular myocardium by gadolinium-diethylenetriaminepenta-acetic acid enhanced magnetic resonance imaging in hypertrophic cardiomyopathy].
The significance of abnormal high signal intensity observed in left ventricular myocardium by gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) enhanced magnetic resonance (MR) imaging in hypertrophic cardiomyopathy (HCM) patients was assessed by comparison with T1-weighted MR imaging, thallium-201 (201Tl) myocardial scintigraphy, radionuclide angiocardiography, M-mode echocardiography, electrocardiography, and chest radiography. The 16 patients were divided into three groups: 8 patients (group I) with abnormal high signal intensity before and after Gd-DTPA enhancement, 4 (group II) with abnormal high signal intensity only after enhancement and 4 (group III) without abnormal high signal intensity. Thallium-201 myocardial single photon emission computed tomography (SPECT) showed 4 of the 8 patients in group I, 3 of the 4 patients in group II and only 1 of the 4 patients in group III had abnormalities of regional 201Tl uptake in the left ventricular myocardium. No significant difference in left ventricular ejection fraction (LVEF) was seen between groups I, II, and III (64 +/- 13%, 67 +/- 17% and 71 +/- 7%, respectively) although three patients of group I had LVEF of less than 55%. Left ventricular peak filling rates (PFR) of groups I and II were significantly lower than that of group III (1.90 +/- 0.44, 2.41 +/- 0.43 and 3.37 +/- 0.48 EDV/sec, respectively). Group I had larger end-diastolic left ventricular dimension (LVDd), significantly larger end-systolic left ventricular dimension (LVDs), and smaller % fractional shortening (%FS) than group III (49 +/- 4 vs 42 +/- 6 mm, 31 +/- 5 vs 22 +/- 4 mm, and 38 +/- 8 vs 49 +/- 4%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
[Relationships between atmospheric Sugi (Japanese cedar)-pollen counts and indices of climatic conditions].
Atmospheric pollen surveys have been conducted using Durham's standard sampler for 12 years in Toyama Prefecture. The relationships between Sugi (Japanese cedar, Cryptomeria japonica D. Don) pollen and some indices of climatic conditions were analyzed. The results were as follows: 1. Total pollen counts showed a tendency to increase for 12 years, although the variation of the count was relatively large. 2. Significant correlations were found between pollen counts and some indices of the climatic conditions in July of the previous year, such as duration of sunshine, mean daily temperature and daily maximum, as well as minimum temperature. 3. Significant correlation was found between pollen count and duration of sunshine in January and March, and the amount of snowfall in March of the observed year using multiple regression analysis. Pollen counts were shown to be relatively high in years with short sunshine in January and long sunshine and heavy snow in March.
Climate↗
[A case of mucinous cystadenocarcinoma of the pancreas with intraductal growth to the main pancreatic duct].
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Aged↗
[Influence of cardiopulmonary bypass on biological response].
To investigate the influence of cardiopulmonary bypass (CPB) on biological response, we measured the serum level of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and granulocyte elastase (GEL) in 24 patients who underwent elective cardiac surgery and 32 patients who underwent elective gastroenterological surgery. All patients were alive. The serum level of GEL in cardiac patients was significantly higher than that in gastroenterological patients on the 1st and the 3rd postoperative day (P = 0.00008, P = 0.00097 respectively). In addition. there was a significant relationship between CPB time and the serum level of GEL immediately after CPB (r = 0.53, P = 0. 007). That is a reason why higher level of serum GEL in cardiac surgery is due to the bacterial translocation. TNF-alpha and IL-1beta were detected in only :3 patients who underwent over 250 minutes CPB. It is most important to shorten the CPB time in order to decrease the serum GEL and lessen the biological response surgery.
Cardiopulmonary Bypass↗
A novel peridinin-chlorophyll a protein (PCP) from the marine dinoflagellate Alexandrium cohorticula: a high pigment content and plural spectral forms of peridinin and chlorophyll a.
A new type of peridinin-chlorophyll a protein (PCP) was isolated from the marine dinoflagellate Alexandrium cohorticula. Unlike previous studies. PCP was obtained as a single component in the presence of a protease inhibitor. The monomer had a molecular mass of 37 kDa with 12 peridinin molecules associated with 2 chl a molecules. This pigment content was much higher than that reported previously. We observed a partial amino acid sequence of the N-terminus that is novel among photosynthetic pigment-protein complexes. Magnetic circular dichroism clearly indicated that chl a in PCP had monomeric features. Multiple spectral components were suggested for both chl a and peridinin. Based on the high pigment content, the optical properties were compared with those for a reported PCP containing 4 chl a and 1 peridinin.
Amino Acid Sequence↗
Induction of heat shock 70 mRNA by cadmium is mediated by glutathione suppressive and non-suppressive triggers.
The induction mechanism of heat shock 70 (Hsp70) gene by cadmium was investigated. In human amniotic WISH cells, Hsp 70 was induced by cadmium in a dose- and time-dependent manner. Cadmium-induced Hsp70 mRNA levels were enhanced 3- to 4-fold after depletion of intracellular glutathione (GSH) by either diethylmaleate or buthionine sulfoximine. Under these conditions, hydrogen peroxide might increase in the absence of substrate for glutathione peroxidase. We found that exogenous hydrogen peroxide alone induced Hsp70 which was further enhanced significantly after GSH-depletion by diethylmaleate. On the other hand, treatment of cells by diethyldithiocarbamate, an inhibitor of superoxide dismutase, induced Hsp70 2-fold over the level of control. This induction was further stimulated by cadmium even in the presence of GSH. Furthermore, a 4-fold increase of intracellular GSH by the treatment of cells with glutathione isopropyl ester did not diminish the cadmium-induced Hsp70. Gel mobility shift assays of nuclear extracts, from these differently treated cells, with oligonucleotide containing a promoter region of Hsp70 gene revealed that the levels of Hsp70 mRNA observed in the present study corresponded to the changes of transcription. These results imply that the induction of Hsp70 mRNA by cadmium is mediated at least partly via reactive oxygen species and attenuated by cellular GSH and that some part of cadmium-induced Hsp70 can not be eliminated by GSH, suggesting that multiple signals are functioning for this induction.
Base Sequence↗
Synergistic stimulation of parathyroid hormone-related peptide gene expression by mechanical stretch and angiotensin II in rat aortic smooth muscle cells.
Repetitive cyclic stretch (60 cycles/min) of rat aortic smooth muscle cells dramatically enhances the effect of angiotensin II (AII) on mRNA expression of the vasorelaxant, parathyroid hormone-related peptide (PTHrP). Thus, combined stimulation of rat aortic smooth muscle cells by cyclic stretch and low concentrations of AII, but not either alone, induces a synergistic, marked increase in the PTHrP mRNA level, in a manner dependent on the strength of stretch. This response is accompanied by a synergistic increase in secretion of PTHrP from smooth muscle cells. Removal of extracellular Ca2+ or addition of Ca2+ channel blockers, including Gd3+ and nitrendipine, does not considerably reduce the combined effects of stretch and AII, indicating that this response is not dependent on stretch-induced Ca2+ influx across the plasma membrane. The combined effect of stretch and AII on PTHrP mRNA expression is strongly attenuated by the protein kinase C (PKC) inhibitor staurosporine or by down-regulation of PKC, suggesting that PKC plays an important role in the synergistic response. However, stretch neither elicits activation of phospholipase C or PKC by itself, nor does it enhance AII-induced activation of these enzymes. These results indicate that in vascular smooth muscle cells mechanical stretch acts together with the vasoconstrictor AII to regulate the expression of the vasodilator PTHrP and suggest the role of PTHrP as a local modulator of myogenic tone.
Alkaloids↗
[Percutaneous radiofrequency coagulation therapy for liver tumor: experimental study].
We invented a newly devised local thermal therapy using radiofrequency energy for treating liver tumors. This method was investigated for evaluating its safety and effectiveness. In vitro study, the maximum size of coagulated albumen was 5.5 to 6.2mm in diameter, and 9.8 to 11.3mm in length. In vivo study using rabbit's liver, the range of coagulated tissue by radiofrequency energy was localized around the tip of the needle. Percutaneous radiofrequency coagulation therapy will be the effective therapy for liver tumor regardless of tumor vascularity.
Animals↗
A comparison of sevoflurane with halothane, enflurane, and isoflurane on bronchoconstriction caused by histamine.
This study was conducted to assess the effect of sevoflurane on lung resistance and compliance, and its responsiveness to histamine. We studied eight dogs to compare the effect of sevoflurane, isoflurane, enflurane, and halothane on bronchoconstriction caused by histamine. Baseline values of pulmonary resistance (RL) and dynamic pulmonary compliance (Cdyn) were measured prior to administration of histamine. Histamine (2, 4, and 8 micrograms.kg-1) were administered iv, and the values of RL and Cdyn at the time of peak effect were recorded. Under 1 or 2 MAC anaesthesia, sevoflurane as well as the other three anaesthetics had no bronchoactive effects. The four anaesthetics, including sevoflurane, demonstrated inhibitory effect on increases in RL and decreases in Cdyn caused by histamine. At 1 MAC anaesthesia, % changes in RL caused by 2, 4, or 8 micrograms.kg-1 of histamine were 38 +/- 11, 85 +/- 21, or 132 +/- 24% (mean +/- SE) for halothane, and 65 +/- 11, 132 +/- 15, or 172 +/- 19% for sevoflurane, respectively. Sevoflurane was less effective than halothane in preventing increases in RL. In preventing decreases in Cdyn, sevoflurane was less effective than halothane only at 8 micrograms.kg-1 of histamine under 1 and 2 MAC anaesthesia. There was no difference in attenuating effect on changes in RL and Cdyn between sevoflurane and isoflurane or enflurane. We concluded that sevoflurane was less potent than halothane in attenuating changes in RL and Cdyn in response to iv histamine.
Airway Resistance↗
Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan.
Itai-itai disease is a condition caused by long-term exposure of the inhabitants of Toyama prefecture, Japan, to cadmium intoxication. The characteristic clinical features of this disease include renal tubular dysfunction, osteomalacia, and anemia. In order to clarify the pathogenesis of the anemia, the red blood cell count, hemoglobin concentration, hematocrit, serum iron level, total iron-binding capacity, serum ferritin level, serum erythropoietin level, creatinine clearance, fractional excretion of beta 2-microglobulin, and bone marrow morphology were determined in ten patients with Itai-itai disease. Low serum iron or ferritin levels were not observed, and bone marrow aspiration did not reveal any specific hematological disorders. A close relationship was observed between the decrease in the hemoglobin level and the progression of renal dysfunction. Low serum erythropoietin levels were detected despite the presence of severe anemia. These results suggest an important role of renal damage in the anemia which develops in Itai-itai disease.
Aged↗
Pulmonary elimination of methyl tertiary-butyl ether after intraperitoneal administration in mice.
The pulmonary elimination after intraperitoneal administration at three different doses (50, 100, and 500 mg/kg) of methyl tertiary-butyl ether (MTBE) was studied using mice. There were two exponential curves with an initial rapid decrease of the elimination ratio followed by a slow decrease at the doses of 100 mg/kg and 500 mg/kg. The calculated half-lives of the two elimination curves obtained by the least squares method were approximately 45 min and 80 min. The pulmonary elimination ratios at the three different doses were from 23.2% to 69.0%. Most of the excreted MTBE was eliminated within 3 h. It is suggested in this paper that MTBE in exhaled air can be used as a biological exposure index for the exposure assessment of MTBE.
Animals↗
Biodegradation and toxicity to fish of di-long-chain tertiary amine salt containing ester and amide bonds.
Biodegradability of N-(3-alkanoylaminopropyl)-N-(2-alkanoyloxyethyl)-N- methylammonium chloride (EAA) was investigated. Biodegradabilities by biochemical oxygen demand (BOD) and dissolved organic carbon (DOC) after 28 days were 79 and 91%, respectively, and almost the same amount of ammonium ion as the theoretical value was detected using a modified MITI test (I) (OECD guidelines, 301C). In the test with activated sludge obtained from a municipal sewage treatment plant, biodegradabilities by BOD and DOC after 35 days were 87 and 98%, respectively, and the 1H-NMR analysis of the tested solution which was done separately under similar conditions indicated the rise and fall of two biodegradation intermediates. Therefore, EEA was considered to be a readily and ultimately biodegradable compound. Besides, the 96-hr LC50 value in red killifish (Oryzias latipes) of EAA was 66 mg/liter. More than 1000 mg/liter was of biodegradation intermediates rapidly made by biodegradation of EAA. These results reveal that EAA has sufficient environmental compatibility.
Animals↗
Co-regulated expression of glomerular 12/15-lipoxygenase and interleukin-4 mRNAs in rat nephrotoxic nephritis.
Arachidonate 12- and 15-lipoxygenase (LO) products are generated in experimental glomerulonephritis. 15-S-HETE (a 15-LO product) and lipoxins (interaction products between 5-LO and either 12-LO or 15-LO) counteract the proinflammatory actions of leukotrienes. IL-4 has been shown to up-regulate 15-LO gene expression in human leukocytes. Based on homology with human 15-LO, we cloned a 0.76 kbp fragment of a rat LO cDNA from leukocytes stimulated by interleukin-4 (IL-4). The deduced amino acid sequence shows 71.0% and 60.1% homology to human 15-LO and 12-LO, respectively, and 100% homology to a recently cloned "leukocyte type" rat 12-lipoxygenase enzyme, which possesses significant 15-lipoxygenase activity (heretofore referred to as "12/15-LO"). A deletion mutant was utilized to generate internal standard cRNA in quantitative PCR assays. Glomerular 12/15-LO mRNA increased significantly over controls 24 and 48 hours after NTS injection, then decreased at 72 hours. RNA from NTS glomeruli contained higher levels of 12/15-LO mRNA than that from unstimulated peripheral leukocytes, suggesting that 12/15-LO transcription is up-regulated locally in native and/or infiltrating glomerular cells. Glomerular IL-4 mRNA increased markedly 16 hours post-NTS, and was then reduced, suggesting a potential role for T cell-derived IL-4 in directing the expression of 12/15-LO during glomerulonephritis. This represents the first demonstration of tandem regulated in vivo gene expression for a lymphokine (IL-4) and a lipoxygenase, both of which promote counter-inflammatory influences in immune complex-mediated injury.
Amino Acid Sequence↗