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H Shimada

Publications and source records attributed to H Shimada.

At least 19 recordsLinked to original sources
PubMed1992

[The relationship between evaluation of school stressors and stress responses in junior high school students].

The purpose of this study is to develop a school stressor scale from the events experienced frequently by junior high school students in their daily school life, and to examine the relationship between school stressors and stress responses. In study I, factor analysis of data by 552 students revealed four main factors "teacher", "friend", "club activity", and "study", which were extracted from initial set of 72 items. In study II, factor analysis of 50 items, of which 39 items were extracted in study I, and 11 new items of free-description type, of data by 622 students, revealed that main stressors in junior high school were following six, "teacher", "friend", "club activity", "study", "rule", and "official activity". Furthermore, multiple regression analyses revealed that "friend" strikingly correlated with "depressive-anxious emotion" and "study" did with "cognition-thought of helplessness".

Adolescent↗
PubMed1992

[A clinicopathologic study of atrial infarction complicating left ventricular posterior myocardial infarction].

Among a series of 400 consecutive autopsy cases we performed a clinicopathologic study of atrial infarction in 46 autopsy-proven cases, which had acute or old left ventricular (LV) myocardial infarction. We used blocks taken from both atrial appendages, the region of the sinus-node, the lateral wall of the right atrium, the posterior wall of the right atrium, and the posterolateral wall of the left atrium. Atrial infarction was identified in 13 (28%) of 46 cases with LV posterior infarction which was caused by lesions of the right coronary artery; 10 cases were right atrial infarction and 3 were both right and left atrial infarction. Among 13 cases in which the acute phase of ventricular infarction could be followed, 3 cases exhibited transient atrial fibrillation. Of these 3 cases, 2 had atrial infarction. The mean stenotic index of the proximal right coronary artery was 4.3/5 in the 13 cases of atrial infarction, 3.2/5 in 17 cases of acute necrosis or scar and 3.1/5 in 16 cases without ischemic atrial lesions. Most of the atrial infarction was found in the right atrium; 10 in the right atrial appendage, 8 in the right atrial lateral wall, 3 in the region of the sinus node and the left atrial posterolateral wall, 2 in the right atrial posterior wall, and one in the left atrial appendage. In conclusion, the incidence of atrial infarction was unexpectedly high (28%) in LV posterior infarction caused by lesions of the proximal right coronary artery, particularly in severe stenosis or obstruction.

Aged↗
PubMed1979

Mutagenicity studies of 4-(2-carboxyethyl) phenyl trans-4-aminomethylcyclohexane carboxylate hydrochloride (DV-1006). A new antiulcer drug.

An antiulcer drug, 4-(2-carboxyethyl) phenyl trans 4-aminomethylcyclohexane carboxylate hydrochloride (DV-1006), was studied for mutagenicity using bacterial systems, in vitro and in vivo cytogenetics, and dominant lethal tests. No mutagenicity of DV-1006 was observed either in the rec-assay on Bacillus subtilis or in the Salmonella/microsome test (Ames test). In in vitro cytogenetics, DV-1006 had no effects on the chromosomes of chinese hamster cells at cytotoxic doses. Rats were treated singly or on 5 consecutive days orally with dose levels of 16, 160, or 1600 mg DV-1006/kg for detecting cytogenetic effects in vivo. As a result, no increase of the incidence of chromosomal aberrations in bone marrow cells was observed in any group of DV-1006. A single or 5 daily oral administration of DV-1006 (16 or 1600 mg/kg) to male mice and subsequent mating for 8 weeks produced no dominant lethal mutational effects. These results show that DV-1006 has no mutagenic potential.

Animals↗
PubMed1979

Influence of hemodialysis on electrocardiographic wave forms.

Alterations in Frank lead electrocardiograms induced by hemodialysis were investigated in 19 patients with chronic renal failure. The most prominent findings after hemodialysis were marked increases in the magnitudes of the R wave in Leads X,Y, and Z, and of the maximal QRS vectors in the frontal, sagittal, and transverse planes. Echocardiographic and roentgenographic examinations revealed no evidence of pericardial effusion before and after hemodialysis. Although the true origin of these findings remains undetermined, it appears reasonable to speculate that the decreased intracavitary blood volume due to hemodialysis may cause an increase in the QRS voltage by a short-circuiting effect. It should be emphasized that a sudden increase in QRS amplitude after hemodialysis might lead to an erroneous diagnosis of left ventricular hypertrophy. The clinician should be aware of such voltage increases when examining the ECGs of patients who undergo hemodialysis.

Adolescent↗
PubMed1978

Magnetic circular dichroism of Pseudomonas putida cytochrome P-450 in near infrared region.

Magnetic circular dichroism spectra of oxidized, reduced and carbonmonoxy reduced forms of cytochrome P-450 from D-camphor grown Pseudomonas putida (P-450cam) were studied in the near infrared region (650 to 1200 nm) at various temperatures in the presence of D-camphor. Oxidized P-450cam with camphor exhibited positive (+) and negative (-) magnetic CD bands at 825 and 970 nm, respectively, and both of them were assigned to Faraday B terms. The magnetic CD spectrum of reduced P-450cam in the presence of D-camphor exhibited at least five components in the region between 650 to 1175 nm and one of them at 760 nm showed considerably smaller magnitude than that of the corresponding band of deoxymyoglobin. These results were interpreted to mean that the heme-iron in both oxidized and reduced P-450cam has a ligand field symmetry lower than C4v, i.e. a strong rhombic character of the heme in cytochrome P-450. Carbonmonoxide complex of reduced P-450cam exhibited no detectable magnitude of magnetic CD in the near infrared region but showed CD bands at 710 (-) and 850 (+) nm. The results were compared and discussed with those of carbonmonoxy hemoglobin and myoglobin. In addition, temperature dependent changes in the spin state of oxidized P-450cam from high to low by decrease of temperature were observed by measuring both magnetic CD and absorption spectra in the near ultraviolet and visible regions (300 to 650 nm), provided that the temperature of the sample was varied slowly (approximately 3 degrees C/min) between room and liquid nitrogen temperature in a 0.03 M phosphate buffer (pH 7.2) containing a saturated amount of D-camphor and 70% (v/v) glycerol. The significance of this phenomenon is also discussed.

Circular Dichroism↗
PubMed1978

Human hepatocytes and aging: a cytophotometrical analysis in 35 sudden-death cases.

Alterations in the nuclear and cellular size of human hepatocytes occurring with age, and particularly in senescence, were studied by microphotometry. The material studied was obtained in 35 cases of sudden death, involving 17 males and 18 females ranging in age from 16 to 100 years. Cells of the peripheral zones of hepatic lobules were analyzed. The following results were obtained: 1. The mean nuclear area of hepatocytes remained relatively constant in subjects under 60 years of age but showed an increase in those over 60, this increase being associated with a greater standard deviation. 2. Volumetric analysis showed that the modal value included between 61 and 100% (mean 86%) of the cell nuclei examined and did not increase with age. This cell population was presumed to consist of diploid cells, the size of which remained constant. 3. An increase in mean nuclear area was due to the appearance of cells with larger nuclei which probably were the result of polyploidization. 4. Hepatocyte size increased with age. Analysis of the nucleus-to-cell sizes showed that the increase in cell size with age was more significant than the increase in nuclear size. 5. Cellular enlargement was more closely correlated with decrease in gross liver weight than with nuclear enlargement.

Adolescent↗
PubMed1978

Ultrastructure of the Bunina bodies in anterior horn cells of amyotrophic lateral sclerosis.

Light and electron microscopic studies were made on the anterior horn cells in a case o amyotrophic lateral sclerosis. Eosinophilic inclusions of Bunina type were observed almost selectively in the motor neurons of spinal cord, as well as of brain stem, at the light microscopic level. Fine structural study revealed the presence of two types of cytoplasmic inclusions. The first, mainly corresponding to the light microscopic inclusions, were homogeneous, electron-dense, round- or oval-shaped bodies with vesicular or tubular rims and ribosome particles, about 2-5 mu in diameter, which contained filaments or other cytoplasmic componenets in the clear areas within them. The second were lamellar structures (laminated cytoplasmic bodies, Morales) which appeared to be originating from endoplasmic reticulum. There was no distinct transition in these two types of inclusions and the relationship to each other is not clear. The significance of Bunina body is unknown, but some manifestation of a primary disorder, e.g., protein metabolism, rather than a secondary degenerative change in the motor neurons in amyotorophic lateral sclerosis.

Adult↗
PubMed1978

Reaction of cytochrome c with nitrite and nitric oxide. A model of dissimilatory nitrite reductase.

The reaction of bovine heart ferrocytochrome c with nitrite was studied under various conditions. The reaction product was ferricytochrome c at around pH 5, whereas at around pH 3 it was Compound I, characterized by twin peaks at 529 and 563 nm of equal intensity. However, ferrocytochrome c decreased obeying first-order kinetics over the pH range examined, irrespective of the presence or absence of molecular oxygen. The apparent first-order rate constant was proportional to the square of the nitrite concentration at pH 4.4 and it increased as the pH was lowered. At pH 3 the reaction was so rapid that it had to be followed by stopped-flow and rapid-scanning techniques. The apparent rate constant at this pH was found to increase linearly with the nitrite concentration. Based on these results the active species of nitrite was concluded to be dinitrogen trioxide at pH 4.4 and nitrosonium ion, no+, at pH 3. Compound II was formed by reaction of ferrocytochrome c and NO gas at acidic and alkaline pH values. The absorption peaks were at 533 and 563 nm at pH 3, and at 538 and 567 nm at pH 12.9. This compound was also formed by reducing Compound I with reductants. Compound I prepared from ferricytochrome c and NO was stable below pH 6. However, appreciable absorption peaks for ferrocytochrome c appeared between pH 8 and 10, because Compound I was dissociated into ferrocytochrome c and NO+, and because ferrocytochrome c thus formed reacted with NO very slowly in this pH region. Saccharomyces ferricytochrome c under NO gas behaved differently from mammalian cytochrome, indicating the significance of the nature of the heme environment in determing the reactivity. Only at extreme pH values was Compound II formed exclusively and persisted. A model system for dissimilatory nitrite reductase was constructed by using bovine heart cytochrome c, nitrite and NADH plus PMS at pH 3.3, and a scheme involving cyclic turnover of ferrocytochrome c, Compound I and Compound II is presented, with kinetic parameters.

Animals↗