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Biomedical subjects

S Matsui

Publications and source records attributed to S Matsui.

At least 289 records · Page 16Linked to original sources
PubMed1988

[Differentiation of hypertrophic cardiomyopathy from left ventricular hypertrophy induced by essential hypertension using magnetic resonance imaging].

To examine the efficacy of magnetic resonance imaging (MRI) in diagnosing hypertrophic cardiomyopathy (HCM), 16 patients with HCM and 14 hypertensives with left ventricular hypertrophy (LDH) were studied using a 0.5 Tesla Siemens MRI apparatus equipped with cardiac gating. In HCM, left ventricular hypertrophy was localized to the septal wall in four, to the apical wall in two, to both the septal and apical walls in two, and to the apical and inferior walls in one, and it was diffuse in seven patients. In hypertensives, LVH was localized to the septal wall in three, to both the septal and anterior walls in two, to the free wall in one, and it was diffuse in eight patients. The distribution of the hypertrophic portion was nearly equal in both groups. The thickest portion of the left ventricular wall was 24.6 +- 4.8 mm in HCM and 21.6 +- 5.4 mm in hypertension, and there was no significant difference between them. The T2 relaxation time of the hypertrophic portion was 52.2 +- 4.8 msec in HCM and 45.3 +- 6.1 msec in hypertension, and there was a significant difference between them (p less than 0.01). However, there were no significant differences between the T2 relaxation times of the hypertrophic and non-hypertrophic portions in both groups. In conclusion, it may be difficult to differentiate HCM from hypertension based on the distribution of hypertrophic portions, but measurements of the T2 relaxation times may be useful for making the differential diagnosis.

Cardiomegaly↗
PubMed1988

[Cerebral metastasis from malignant thymoma].

Thymoma with extrathoracic metastasis is very rare, especially to the central nervous system. As far as we know, this is the 15th reported case of cerebral metastasis from malignant thymoma. The prognosis is very poor and almost all of them die in one to one and half years. We have experienced such a case, who is 56 years old man, presenting Gerstmann's syndrome and right-hemiparesis 8 months later after thoracotomy for removal of thymoma. At the admission time in this hospital, CT findings proved the tumor in the left temporoparietal area, left ventricle deformity and slight midline shift to right side. The average of CT density in the low density area was 20. Peripheral region of the tumor was enhanced by contrast CT. Left carotid angiography showed the ACA shift to the right side and abnormal vascularity of peripheral branches of angular artery (arterial phase) and also tumor strain in late artery (arterial phase) and also tumor strain in late arterial phase. Brain scintigram revealed accumulation in the left parietal region. The rt-hemiparesis was rapidly going to be rt-hemiplegia. Therefore, we have performed needle puncture to prevent rt-hemiplegia at the first time. In the course of needle puncture, 90 ml of dark and red fluid was gained at 3.0 cm depth from the cerebral surface. Immediately, the above two symptoms have improved remarkably. Post operative CT showed the reduction of tumor and improvement of the midline shift. The radical operation have been done 2 days after the needle puncture. The tumor was elastic-soft and hemorrhagic and appeared dark-red.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1987

Influence of cadmium on the metabolism of vitamin D3 in rats.

In order to obtain further information on the effects of cadmium (Cd) on the mechanism of activation of vitamin D3 in the kidney, the serum concentrations of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] and 24,25-dihydroxycholecalciferol [24,25(OH)2D3] were determined by radioimmunoassay techniques. The serum concentration of 1,25(OH)2D3 in Cd-exposed rats was always higher than that in control rats. The concentrations of serum 1,25(OH)2D3 in parathyroidectomized rats (PTX), both in the control and in the Cd-exposed groups, were markedly lower than those in non-PTX rats. On the other hand, the concentration of serum 24,25(OH)2D3 in Cd-exposed rats was less than that in control rats. In other words, the pathway from secretion of parathyroid hormone (PTH) to synthesis of 1,25(OH)2D3 or 24,25(OH)2D3 was normal, but the pathway from stimulation of PTH to secretion of PTH was abnormal. These results suggest that rats exposed to Cd for 90 days were in a state of either deficiency of 1,25(OH)2D3 or excess secretion of parathyroid hormone. Although hypophosphatemia occurred in the Cd-exposed rats, the 1,25(OH)2D3 serum level in rats was not increased by PTX. On the basis of these results, it is suggested that hypophosphatemia occurring after the exposure of rats to Cd is a secondary hypophosphatemia.

24,25-Dihydroxyvitamin D 3↗
PubMed1987

A rapid assay method for ammonia using glutamine synthetase from glutamate-producing bacteria.

A rapid enzymatic assay method for ammonia was developed by using glutamine synthetase from glutamate-producing bacteria together with pyruvate kinase, lactate dehydrogenase, and NADH. The time required for determination of 25 nmol of ammonia was 5 min with 1 unit of glutamine synthetase, as opposed to 14-30 min with 1 unit of glutamate dehydrogenases from various sources. The present method was used to determine ammonia in serum, microbiol-culture broth, and waste water. The method can be modified for spectrophotometry in the visible region by substituting pyruvate oxidase, peroxidase, and appropriate chromogens for lactate dehydrogenase and NADH. With 4-aminoantipyrine (4AA) and phenol, and with 4AA and N-ethyl-N-2-hydroxyethyl-m-toluidine as chromogens, the sensitivity of ammonia determination was 0.65 and 1.7 times that with glutamate dehydrogenase, respectively. The present method was also applicable to the continuous detection of the activity of some ammonia-forming enzymes such as guanase, adenosine deaminase, and urease and to the determination of 0.5-30 microM ATP-ADP after some modification of the mixture.

Adenosine Diphosphate↗
PubMed1987

Heparin binding affinity of rat prostatic growth factor in normal and cancerous prostates: partial purification and characterization of rat prostatic growth factor in the Dunning tumor.

The rat prostate contains two types of growth factors capable of stimulating DNA synthesis in BALB/3T3 cells. These rat prostatic growth factors (RPGF) were separable by a different affinity for heparin: low affinity type RPGF and high affinity (HiA) type RPGF. About 80% of the RPGF in the cytosol from normal prostates was low affinity type, whereas more than 80% in the cytosol from the Dunning tumors was HiA type. Elution profile of HiA-RPGF showed two peaks of activity eluted from the heparin-Sepharose column, one at 1.3-1.4 M NaCl (HiA1-RPGF) and the other at 1.6-1.7 M NaCl (HiA2-RPGF). HiA2-RPGF could be purified 1100-fold from the Dunning tumor (AT-3 subline) in about 20% recovery by heparin-Sepharose chromatography. The partially purified HiA2-RPGF in the Dunning tumor has a molecular weight of about 19,000 and isoelectric point of about 3.8, and stimulated DNA synthesis at a concentration of about 0.25 nM. The activity was lost by heat treatment at 70 degrees C for 5 min and by acid treatment, whereas it was stimulated by incubating with dithiothreitol. The HiA2-RPGF did not have transforming growth factor activity at a concentration of 250 ng/ml or lower in the presence of epidermal growth factor.

Animals↗
PubMed1987

Isolation of a 41 kilodalton cytosol protein from the Dunning rat prostatic adenocarcinoma: characterization as depolymerized actin isomers.

Except for albumin, a 41,000-dalton protein (41K) in the cytosol of the Dunning R-3327 rat prostatic adenocarcinoma was found to be the most abundant soluble protein. This protein was purified in nearly homogeneous state by conventional chromatographies. After the first chromatography, because of the adhesive nature of the protein, 0.5% SDS and 2 M urea were necessary for subsequent steps of purification. The amino acid composition of the purified 41K was similar to that of actin isolated from rabbit skeletal muscle. Alternatively, 41K could be extracted from the Dunning tumor in the presence of ATP and dithiothreitol, under conditions in which actin molecules are depolymerized, and could be purified by the same method as cytoskeletal actin. The purified protein showed properties similar to rat skeletal muscle actin in amino acid composition and antigenicity. Both 41K proteins were found to be composed of four components having different isoelectric points. These results indicate that most actin exists in a depolymerized form as a cytosol protein of 41,000 daltons in the Dunning tumor and is composed of at least four isomers.

Actins↗
PubMed1987

Interaction of lymphocytes with hepatocytes containing hepatitis B antigen: ultrastructural demonstration of target antigen and T-cell subsets by the peroxidase antibody technique.

Hepatitis B virus associated antigens and subsets of lymphocytes in liver tissue were studied using immune electron microscopy to clarify the immune mechanism of hepatocyte lysis in type B chronic hepatitis. Using conventional electron microscopy, infiltrating lymphocytes were observed in direct contact with hepatocytes in areas of piecemeal necrosis and focal necrosis; they showed various types of surface adherence with a contact gap of approximately 20 nm in width. The majority of the hepatocytes that were in contact with lymphocytes could be shown to contain HBsAg and/or HBcAg by immune electron microscopy: HBsAg was localized in the endoplasmic reticulum membranes, in tubular structures, and on the outer coat of Dane particles; HBcAg was observed in the nuclei and in the cytoplasmic matrix of hepatocytes. In some cases HBsAg was observed on the plasma membrane of hepatocyte in contact with lymphocytes. Immune electron microscopy using monoclonal antibodies to subsets of human T-lymphocytes revealed that the lymphocytes in areas of piecemeal necrosis and focal necrosis were predominantly CD 5 or CD 8 positive. In contrast, CD 4 positive cells were infrequently observed in necro-inflammatory regions and Leu 7 positive cells were randomly scattered in the sinusoids away from areas of hepatocyte necrosis. These data suggest that HBsAg is at least one of the target antigens expressed on the hepatocyte membrane possibly enabling cytolytic interaction by cytotoxic T cells in chronic type B hepatitis.

Antigens, Differentiation, T-Lymphocyte↗