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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 253 records · Page 14Linked to original sources
PubMed1985

Significance of elemental analysis of hair as a means of detecting environmental pollution.

The correlation of metal concentrations in hair with those in the critical organs was investigated by tracer studies using 51Cr, 203Hg, 75Se, 109Cd, and 65Zn in mice. The accumulation of these elements in organs of the mouse (including hair) during acute contamination was confirmed. Chronic studies to observe stable zinc and cadmium concentrations in various organs of the mouse at different ages manifested clear differences between zinc and cadmium accumulation patterns. The tracer study data on metal concentrations in 11 organs and those obtained by chemical analysis were compared. In the case of zinc, the correlation between the two is high, irrespective of the age of the mice; for cadmium no correlation was present in young mice but a correlation was seen in mice at ages of 19 weeks or more. Thus, the age-dependent variation of metals in organs is another factor that has been considered. Values for concentrations of several metals in critical organs and hair were compiled from the literature and compared. These studies led to the following conclusions: Hair is a reasonable indicator of mercury and chromium contamination, as these elements are readily deposited into hair and stay a comparatively long time. The time-dependent shifts of zinc and selenium in hair reflected their kinetics in the whole body, though their concentrations in hair were not higher than those in other organs. Hair was found to be a poor indicator of cadmium contamination, as the concentration of cadmium in hair was not parallel to that in the critical organs of the same mouse.

Age Factors↗
PubMed1985

A malignant pheochromocytoma with ileus, polyuria and hypercalcemia: a case of recurrence 17 years after the initial operation.

A case of malignant pheochromocytoma, with a recurrence 17 years after the initial diagnosis of benign pheochromocytoma, was presented. The autopsy revealed multiple metastases of pheochromocytoma to the bone marrow of the thoracic and lumbar vertebrae. Of particular note is the fact that the patient was associated with paralytic ileus, polyuria and hypercalcemia and that he died of hypercalcemia crisis. Cases like this appear to be very rare.

Adrenal Gland Neoplasms↗
PubMed1985

[SOL-detectability of liver SPECT--analysis by SOL detection model].

The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). Eleven hospitals which are in or near Tokyo are participating in this study. Planar liver images and SPECT images of 134 cases which were retrospectively confirmed for its final diagnosis were collected. At the first study, the planar images (PS) were read by 13 nuclear medicine physicians. The second, the image reading by the combination of the planar images and the SPECT images (PS + SPECT) were performed. The confidence level of diagnosis for SOL (space occupying lesion) obtained by the image reading of PS and PS + SPECT has been analyzed by using the SOL detection model. The SOL detectability of PS + SPECT was higher than that of PS only. However, these differences were not statistically significant.

Diagnosis, Differential↗
PubMed1985

[SOL-detectability of liver SPECT--analysis of the structure of ROC-curve].

The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). The two examinations were performed in 76 cases with SOL (space occupying lesion) and 58 normal cases. The results of the image reading by the planar image only (PS) and that of the image reading by the combination of PS and SPECT (PS + SPECT) were analyzed by ROC (receiver operating characteristic) analysis. The ROC curves showed that SPECT appears to reduce the number of results which were equivocal by the image reading of PS only. The detectability of SPECT for SOL in the left lobe of liver was less than that of PS without statistical significance. However, the performance of SPECT for SOL in the right lobe of liver was significantly better than that of PS.

Evaluation Studies as Topic↗
PubMed1985

Effectiveness of ECG-gated magnetic resonance imaging in diagnosing cardiovascular diseases.

Nuclear magnetic resonance imaging (MRI) is a noninvasive method which can discriminate between flowing blood and vascular walls, and is expected to contribute to the diagnosis of cardiovascular diseases. Since the data acquisition by conventional MRI is too long for precise cardiac imaging, the ECG-gated method is mandatory in evaluating cardiac function and producing cardiac images of high quality. To evaluate the effectiveness of ECG-gated MRI, left ventricular wall motion and ejection fraction by MRI were compared with those obtained by radionuclide technique. Two types of MR imagers were used: one with a resistive magnet (0.15 Tesla) for 12 patients, and the other with a superconductive magnet (0.35 Tesla) for eight patients. MRI imaged cardiac muscle and vascular walls without the need for any contrast media or radionuclides. The superconductive apparatus provided better quality images than did the resistive one. Comparing MRI with radionuclide technique regarding left ventricular wall motion, resistive and superconductive MRI data correlated satisfactorily with those of radionuclide technique, except in the inferior wall, which was better evaluated by radionuclide technique. Left ventricular ejection fraction obtained by MRI was moderately lower than those obtained by radionuclide technique, though the correlation was good [r = 0.84 (resistive unit) and r = 0.85 (superconductive unit)]. In addition to three-dimensional morphological information, ECG-gated MRI provides information nearly comparable to that of radionuclide technique in the evaluation of left ventricular function and wall motion. Therefore, we regard gated MRI as effective in evaluating various aspects of cardiovascular diseases.

Adult↗
PubMed1984

Exogenous ATP induces electrical membrane responses in fibroblasts.

Mouse fibroblastic L cells responded to exogenous ATP (greater than or equal to 0.2 mM) with a transient hyperpolarization due to increased membrane permeability to K+. By contrast, intracellular injection of ATP (up to about 3 mM) produced no noticeable effects on the membrane potential. The effects of a non-hydrolysable analogue of ATP (AMP-PNP) were similar to those of ATP. After successive applications of ATP, the cell membrane became virtually unresponsive (desensitized). Extracellular ADP was also effective, but AMP or adenosine was not. Antazoline suppressed the ATP response. Thus, exogenous ATP and ADP appear to stimulate P2- purinoceptors . Similar responses to ATP (or ADP) were also observed in human normal diploid fibroblasts (Flow 1000 line).

Adenosine Diphosphate↗
PubMed1984

Granulocytic sarcoma presenting as a mediastinal tumor. Report of a case and cytological and cytochemical studies of tumor cells in vivo and in vitro.

An unusual case of granulocytic sarcoma in a 23-year-old man is reported. The patient initially presented with mediastinal tumor and was diagnosed clinically as having thymoma. The patient was treated by radiotherapy and surgical removal of the tumor. Histology of the excised tumor had been nondiagnostic because of extensive fibrous changes. Eight months later, the patient developed pleural effusion on the right, which soon was followed by blood and bone marrow pictures consistent with acute promyelocytic leukemia. In vitro culture of pleural effusion cells unexpectedly gave rise to a continuously growing peroxidase-positive myeloid cell line. Autopsy revealed the recurrent mediastinal tumor to be positive for intracytoplasmic naphthol AS-D chloroacetate esterase and lysozyme activity. From these findings, the patient retrospectively was diagnosed as having mediastinal granulocytic sarcoma, which terminated in pleural effusion and acute promyelocytic leukemia.

Adult↗
PubMed1984

Establishment of a new peroxidase-positive human myeloid cell line, PL-21.

A myeloid cell line, designated PL-21, was established from the peripheral blood of a patient with acute promyelocytic leukemia. The PL-21 cell line grew in single-cell suspension, with a doubling time of 48-64 hr, and consisted of promyelocytes with fine immature nuclei and prominent azurophilic granules in the cytoplasm. PL-21 cells were positive for peroxidase, naphthol AS-D chloroacetate esterase, and Sudan Black B staining. Under the usual culture conditions, a small proportion of these cells differentiated into mature granulocytes, and this differentiation was enhanced by the addition of dimethyl sulfoxide in the culture medium. PL-21 cells had receptors for the Fc portion of IgG and complement, intracytoplasmic lysozyme and phagocytic activity, but lacked Epstein-Barr virus-associated nuclear antigen. Chromosome analysis of this cell line revealed a human male polyploid karyotype with 13q+ and double minute chromosomes. This new myeloid cell line may provide useful material for the study of proliferation and differentiation of human leukemia cells.

Adult↗
PubMed1984

[Prospective study to assess the clinical efficacy of bone scintigraphy--methodology and some preliminary results].

The purpose of this study is to evaluate prospectively the value of radionuclide bone scans at the preoperative assessment of carcinomas of the breast and prostate carcinomas. Ten hospitals which are in or near Tokyo are participating in this study. For each patient under study, three kinds of sheet are filled by doctors. The first sheet named "preexamination diagnosis data sheet" is recorded before preoperative bone scan by attending physicians mainly. The second sheet named "postexamination diagnosis data sheet" is recorded after preoperative bone scan by nuclear medicine physicians who performed bone scintigraphy. The third sheet named "final diagnosis data sheet" is recorded after about a year of follow up period by attending physicians or nuclear medicine physicians. These data have been stored in a electric computer. Some preliminary analysis has been made by comparing the confidence level of diagnosis for bone metastasis before and after bone scintigraphy. In this report, methodology of the analysis and some results are described.

Adult↗