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Biomedical subjects

M Ishijima

Publications and source records attributed to M Ishijima.

At least 19 recordsLinked to original sources
PubMed1997

[A preliminary study on transurethral electrovaporization of the prostate (TVP) using VaporTrode].

BACKGROUND: Surgical therapy for Benign Prostatic Hypertrophy (B.P.H.) has mainly depended upon Transurethral Resection of the Prostate (TUR-P) using a cutting loop electrode. Recently, a new technique TVP was reported using the VaporTrode apparatus. We assessed the safety and efficacy of the VaporTrode in a preliminary study. METHODS: Histological changes of the muscle and liver of pigs were examined after vaporization using the VaporTrode and a cutting loop electrode. First, histological changes were investigated following vaporization after one stroke at a slow hand speed. Next, histological changes were assessed following vaporization at fixed stroke speed in an experimental model. RESULTS: At an electrical output of less than 275 W, the depth of the vaporized layer increased as the stroke speed became slower (4.0 cm/s-2.5 cm/s). When the electrical output was 300 W, the depth of vaporized layer increased even at a faster stroke speed (2.5 cm/s-3.0 cm/s.) The depth of the desiccated layer increased as the stroke speed became slower at any electrical output. However, when the stroke speed was 4.0 cm/s, the depth of this layer was less than 2.0 mm. With the cutting loop electrode, the depth of the desiccated layer increased at a higher electrical power, but the change was very small. CONCLUSION: To achieve deep enough vaporized and desiccated layers safely, the VaporTrode should be used at a stroke speed slower than 3.0 cm/s and a high electrical power of about 275 W.

Animals↗
PubMed1996

[Clinico-pathological evaluation of leukoaraisosis in Alzheimer's disease].

Patients with multi-infarct dementia often have periventricular low density lesions on computed tomography and periventricular hyper-intensity lesions on computed tomography and periventricular hyper-intensity lesions on magnetic resonance imaging. Hachinski called this condition leukoaraiosis and results of previous studies that in multi-infarct dementia leukoaraiosis correlates with cerebral hypoperfusion. Periventricular low-density lesions in the white matter also occur, but their origin and clinical significance insuch patients is unknown. We studied when these lesions develop in patients with Alzheimer's dementia, and whether their presence correlates with clinical findings and cerebral blood flow. The subjects were 37 patients with a probable diagnosis of Alzheimer's dementia, as based on the Neuroepidermilogy Branch of the National Institute of Neurological Disorders and Stroke and the Alzheimer's disease and Related Disorders Association system. Autopsy findings were also available for 2 patients. Patients at higher Functional Assessment Staging of Senile Dementia of Alzheimer Type stages had more extensive periventricular low-density lesions. Patients with the lesions were more likely to have grasp reflex and sucking relex. Blood flow to the frontal and parietal cortices was significantly less in patients with the lesions than in those without the lesions. Neither of the 2 autopsies cases yielded evidence of arteriolosclerosis. Periventricular low-density lesions in Alzheimer's dementia may be closely associated with a degenerative process different from that seen in multi-infarct dementia.

Alzheimer Disease↗
PubMed1996

Determination of serum des-gamma-carboxy prothrombin levels in patients with small-sized hepatocellular carcinoma: comparison of the conventional enzyme immunoassay and two modified methods.

OBJECTIVES: Currently available enzyme immunoassays for des-gamma-carboxy prothrombin (DCP) are not sensitive enough to detect hepatocellular carcinoma (HCC) at an early stage. Therefore, the objectives of this study were to enhance the sensitivity of the currently available enzyme immunoassay (EIA) for DCP and to assess the diagnostic values of the new methods compared with those of alpha-fetoprotein (AFP) in patients with small-sized HCC. METHODS: Coded serum samples obtained from a total of 128 patients with chronic liver diseases, including 27 patients with small-sized HCC, were analyzed. DCP levels were determined in three different ways: 1) conventional EIA, 2) the overnight method, similar to the conventional EIA but the first reaction (immunoreaction of DCP with the monoclonal antibody) was proceeded overnight, and 3) the avidin-biotin complex (ABC) method. RESULTS: In 27 patients with HCC ( < or = 3 cm in diameter), the rates of abnormal values obtained by the conventional, the overnight, and the ABC methods were 14.8, 25.9, and 29.6%, respectively. The overnight and the ABC methods comparably increased the sensitivity, whereas the ABC method gave the highest false-positive value in patients with chronic liver diseases (cirrhosis and chronic hepatitis) without HCC. The negative predictive value was 84.9% when AFP and the overnight DCP assays were combined, whereas the true positive rate by the combination assay of the ABC method for DCP and AFP (cut-off level at 200 ng/ml) was 33.3%. CONCLUSIONS: Two modifications of the conventional EIA for DCP comparably increased the sensitivity, but the overnight method may be of more practical value in terms of specificity and ease. The rate of detection of small-sized HCC by tumor markers alone, however, is not satisfactory even when the modified DCP and AFP measurements are combined.

Adult↗
PubMed1996

[Determination of PIVKA-II levels in patients with small hepatocellular carcinoma--comparison of new sensitive methods].

Current EIA for PIVKA-II is not sensitive enough to detect small Hepatocellular Carcinoma (HCC). In an attempt to increase the diagnostic threshold, the current EIA was modified in two different ways: 1) immunoreaction of PIVKA-II in the sample with its monoclonal antibody was carried out overnight at 5 degrees C instead of for two hours at room temperature (the overnight method), 2) Avidin-Biotin technique was used for the second reaction(the ABC method);and their diagnostic values were determined as compared with the current EIA(2hr method) in a total of 138 patients including 36 patients with HCC. In 27 patients with HCC(< 3 cm in diameter), the rates of abnormal values obtained by the 2hr-, the overnight- and the ABC method were 14.8, 25.9 and 29.6% respectively. False positive rates of these three methods in 69 patients with liver cirrhosis were 1.4, 8.6 and 22.9% respectively. Thus, these two modifications improved the sensitivity of the current EIA and the overnight method appears to be superior to the ABC method in terms of specificity and simplicity. This conclusion was confirmed by ROC analysis.

Biomarkers↗
PubMed1993

Monitoring of electrocardiograms in bed without utilizing body surface electrodes.

We investigated a system by which an electrocardiogram can be obtained without the individual's awareness. The practice of this concept involves placing the electrodes in a bed set composed of electrically conductive textiles. Electrocardiograms were successfully obtained during sleep. However, during the periods of subject's movement in bed, the waveform became unrecognizable.

Adult↗
PubMed1992

Polyarteritis nodosa with aortic dissection: necrotizing vasculitis of the vasa vasorum.

A 59-year-old woman was admitted to our hospital with acute onset of chest pain. She had experienced high fever, weight loss, polyarthralgia, myalgia, polyneuropathy and hallucinations for 3 years before admission. The diagnosis of polyarteritis nodosa with hepatitis B surface antigenemia was made by muscle biopsy and serological examinations, and administration of prednisolone induced remission of all the manifestations. After developing the acute attack of severe chest pain, she died suddenly. At autopsy, a DeBakey type 1 aortic dissection was found and the immediate cause of death was found to be cardiac tamponade secondary to rupture of the aortic dissection. Microscopically, necrotizing inflammatory lesions were present in the medium sized vascular arteries throughout her body. Furthermore, necrotizing vasculitis was also found in the vasa vasorum of the adventitia and media of the thoracic aorta. The dissecting lesion was seen in the outer layer of the media. Our results suggest that spontaneous dissection of the aorta may be attributed to necrotizing vasculitis of the vasa vasorum.

Aortic Dissection↗
PubMed1990

Histopathological study on myocardial hypertrophy associated with ischemic heart disease.

The mode and causes of myocardial hypertrophy occurring in association with ischemic heart disease were studied. The investigation involved autopsied hearts (15 cases of subendocardial infarction, 27 of transmural infarction, 20 of non-infarcted three vessel disease and 17 controls) and biopsied materials obtained during coronary-aorta bypass graft surgery (23 patients with angina pectoris and 46 with myocardial infarction). The subendocardial infarction group showed most marked myocardial hypertrophy that reflected extensive infarction and fibrosis, dilatation of the left ventricular cavity and the loss of myocytes. Despite a marked decrease in the number of myocyte layers, the residual myocardium of the left ventricle was uniformly hypertrophic, accompanied by an increase in the heart weight. The larger the area of fibrosis, the more marked was myocardial hypertrophy irrespective of the luminal diameter of the responsible coronary artery. These findings indicate that myocardial hypertrophy associated with ischemic heart disease is enhanced by the compensatory mechanisms for a decrease in the contractile myocardium due to fibrosis.

Biopsy↗
PubMed1990

The relationship between 24 hour total heart beats or ventricular arrhythmias and cardiopulmonary function in patients with Duchenne's muscular dystrophy.

To evaluate the relationship of 24 hour total heart beats (THB) or ventricular arrhythmias and cardiopulmonary function, 29 patients with Duchenne's muscular dystrophy (DMD) were studied using Holter electrocardiographic and echocardiographic recordings. The THB were 144,428 +/- 12,237 beats per 24 hours in the child group (8 to 15 years, n = 12) and 136,355 +/- 19,991 beats per 24 hours in the adult group (16 to 25 years, n = 17). The THB in the adult group significantly correlated well with % VC (r = -0.74), PaCO2 (r = 0.67), PaO2 (r = -0.59) and the respiration rate (r = 0.71), but not in the child group. In both groups, the echocardiographic parameters of the left ventricular size and function (left ventricular dimension, ejection fraction and D/S ratio) did not significantly correlate with the THB. Premature ventricular contractions (PVCs) were observed in 14 of the 29 patients (48.3%), and high risk PVCs (Lown's grade 3-4b) were observed in 11 of these 14 patients (78.6%). Echocardiographic parameters of the left ventricular function in the high risk PVC group were significantly deteriorated as compared with the low risk PVC group (Lown's grade 0-2) (p less than 0.02-p less than 0.001). We conclude that the THB in the adult group was mainly related to depressed pulmonary function, and the severity of the PVCs in both the adult and child groups was mainly related to the degree of left ventricular dysfunction.

Adolescent↗
PubMed1990

An autopsy case of cardiomyopathy with restrictive physiology in a child.

An autopsy case of cardiomyopathy with restrictive physiology associated with subendocardial myocardial necrosis and fibrosis in a seven-year-old child is described. Cardiac catheterization showed high left ventricular end-diastolic pressure with a dip-and-plateau pattern. Macroscopically, marked dilatation with fibroelastosis in both atria and mild dilatation in both ventricles were observed. Histologic examination revealed extensive subendocardial necrosis with marked disorganization of myocardial cells and moderate arteriolosclerosis. We speculate that these extensive myocardial lesions, which contributed to the restrictive hemodynamic changes, could have been induced by anoxia or a Ca2+ transport abnormality of unknown cause.

Cardiomyopathy, Restrictive↗
PubMed1989

Relation between coronary stenosis and myocardial lesions determined by a semiquantitative approach to myocardial fibrosis and hypertrophy due to ischemia.

To clarify the cause of myocardial hypertrophy in ischemic heart disease, the relation between the extent of fibrosis and myocyte diameter was examined in patients with cardiac hypertrophy of unknown etiology except for coronary sclerosis. In 79 unselected cases, the heart weight tended to be higher in patients with severe coronary stenosis and fibrosis. In a morphometric study of 33 additional hearts of patients without a clinical history of hypertension, valvular disease or diabetes mellitus, 15 of which had anterior infarction, a positive correlation (r = 0.63) was observed between myocyte diameter and the percent area of fibrosis in the anterior wall of the left ventricle. In the heart of patients with severe coronary stenosis (more than 75% luminal narrowing), the regression coefficient was 0.83. The hearts of 8 patients with nontransmural infarction showed a strong correlation between myocyte diameter and fibrosis, compared with the hearts of 7 patients with transmural infarction. In most cases, the main mechanism of hypertrophy in ischemic heart disease was considered to be compensatory hypertrophy for existence of myocardial fibrosis.

Adult↗
PubMed1989

Observation of electrocardiograms through tap water.

Preventive diagnosis is important. Daily medical check-ups in the home which require little effort or practice on the patient's part could be one way to achieve this goal. We investigated the acquisition of electrocardiograms from a human subject in a regular bathtub. In order to prevent power line interference and base line drift due to body movements, an active notch filter and specially designed Ag/AgCl electrodes were utilised. The amplitude of the QRS complex obtained from the water (40 degrees C) was approximately 1/10 that of the direct body surface measurement. Increasing the electrical conductivity of the tap water by adding NaCl (0.2% in weight) resulted in a decrease in amplitude to 1/100 of the direct measurement. Otherwise, the waveform distortion was minimal. It was confirmed that acquisition of electrocardiograms of monitoring quality was feasible in a regular bathtub filled with ordinary tap water.

Electrocardiography↗
PubMed1989

[Management of pacemaker patients by bathtub ECG].

We evaluated the efficacy of a new method for recording electrocardiogram (ECG) of pacemaker patients in bathtub (bathtub ECG). ECG from the pacemaker implanted patients in the bathtub with tap water was recorded through three silver/silver chloride electrodes (4 x 4 cm) fitted on the inside wall of bathtub. Electric signal was connected to the isolated amplifier and recorded on the strip chart recorder. Contrast to the conventional method for recording standard ECG, bathtub ECG does not require body surface electrodes and is recorded at patients home. Although the amplitude of bathtub ECG was reduced approximately to a quarter of standard ECG, cardiac arrhythmia can be easily interpreted by bathtub ECG. In patients with pacemaker system, the amplitude of the pacing pulse recorded by bathtub ECG was much larger than that of QRS complex recorded by standard ECG. Therefore, we conclude that bathtub ECG would be a suitable method to follow up patients with pacemaker system.

Baths↗
PubMed1987

The feasibility of beat-to-beat detection of His-Purkinje activity by finite element method.

A noninvasive method has been applied on human and canine subjects to observe beat-to-beat activity of the His-Purkinje system without using signal averaging. Recordings were performed with multiple Ag/AgCl electrodes, very low noise, high gain amplifiers and by analog filtering. The subjects were in a supine position during the recording. In order to reduce random noise inherent in the high-gain body surface recording, a finite element method (FEM) was applied to calculate His-Purkinje activity. The dimensional relationship between electrode sites, necessary for the calculation, was pre-estimated by x-ray computed tomographs of the subject. A prominent waveform was observed between the atrial and ventricular complexes and corresponded to His bundle activity which was simultaneously recorded by an intracardiac electrode (on every beat). It was, however, difficult to recognize the His-Purkinje activity during inhalation due to the thoracic electromyogram on some human subjects. This interference could theoretically be reduced by increasing the number of body surface electrodes used for this technique.

Animals↗
PubMed1985

Decrease of plasma sulfur amino acids in essential hypertension.

In order to evaluate the correlation between sulfur amino acids (derived mainly form animal protein in the diet) and blood pressure, free amino acids, including sulfur amino acids such as taurine and methionine, were determined in the plasma and cerebrospinal fluid (CSF) of twelve normotensive subjects and twelve patients with essential hypertension under nutritional control after at least 10 days of standard hospital diet (total calorie and protein content: 2100-2300 Cal per day and 78-83 g per day, respectively). The results obtained were as follows: plasma taurine, serine, methionine and threonine were significantly lower in patients with essential hypertension than in normotensive patients. The levels of plasma taurine, serine, methionine and total sulfur amino acids in individuals correlated inversely to systolic blood pressure. No difference was observed in the CSF levels of free amino acids in normotensive and hypertensive patients. As taurine, methionine and serine are involved in the metabolism of sulfur amino acids, these observations support the view that the decrease in plasma sulfur amino acids may be a factor contributing to elevated blood pressure.

Adult↗