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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
PubMed1986

Scintigraphic manifestation of fibrous dysplasia.

Scintigraphic manifestations of fibrous dysplasia were analyzed in 59 lesions of 26 patients (12 monostotic, 14 polystotic). Bone imaging with Tc-99m MDP revealed a high percentage of increased uptake of radioisotope in the lesions of fibrous dysplasia. Four (14%) of 29 cystic lesions and two (7%) of 30 lesions with the appearance of ground glass showed no increase in radioisotope uptake, although roentgenograms showed marked changes. Therefore, care must be taken in the diagnosis of fibrous dysplasia with bone imaging alone. Nuclear methods, however, are indispensable in evaluating the dynamic aspects of bone mineral behavior and in demonstrating disease where none was suspected, or in visualizing polyostotic involvement in those cases where only monostotic disease was suspected clinically. It is concluded that both scintigrams and roentgenograms are complementary procedures in the diagnosis of fibrous dysplasia.

Adolescent↗
PubMed1986

[The study of a two-dimensional polar representation of the cardiac SPECT image--a new method of displaying left ventricular wall motion].

A new method was developed to display left ventricular wall motion using two dimensional polar representation of cardiac SPECT image. After intravenous administration of 740 MBq (20 mCi) 99mTc (in vivo labeling of red blood cell), ECG-gated SPECT image of cardiac pool was recorded (32 directions, 180 degrees). The short axis images of left ventricle were constructed at end-diastole (ED) and end-systole (ES). Then the functional images of (ED-ES)/ED were calculated at each compatible slices and displayed in color according the degree of wall motion. In 8 cases with cardiac diseases this method was applied and clinically useful functional images could be obtained. The area of akinesia or hypokinesia are successfully demonstrated clearly separated from the area of normokinesia. We conclude that this method is useful to show left ventricular wall motion and to evaluate the segment and grade of abnormal wall motion of left ventricle.

Adult↗
PubMed1985

Bioavailability and diuretic effect of furosemide during long-term treatment of chronic respiratory failure.

The bioavailability and diuretic effect of furosemide 40 mg administered orally for at least 6 months have been compared in patients with chronic respiratory failure and in healthy controls. The mean urinary recovery of unchanged drug was 11.5 mg and 9.41 mg in 24 h after pre- and postprandial administration to 10 patients, whereas the recovery was 14.4 mg in 10 healthy subjects. The diuretic effect, in terms of urine flow and sodium ion excretion in the 6 h after administration, was also less in patients than in healthy subjects. This was ascribed to the lower bioavailability of furosemide in patients, based on the urinary recovery of unchanged drug, and not to a lower level of response to furosemide than in healthy subjects. The mean absolute bioavailability of furosemide in 6 patients was 41.3% and 63.4%, respectively, calculated from unchanged drug and total drug (unchanged plus glucuronide conjugate). Approximately 53.9% of the dose of furosemide was excreted as the glucuronide conjugate after oral administration, and 34.2% after i.v. injection in the 6 patients. In 3 of the 6 patients studied, a distinct first-pass effect for glucuronidation of furosemide was observed after oral administration. In another study, the mean glucuronide fraction recovered in 24-h urine was 20.7% and 7.3% (p less than 0.01) in 38 patients and 12 healthy subjects, respectively. The fraction in urine was not affected by changing the dose of furosemide from 20 to 120 mg. The lower bioavailability in patients as compared to healthy subjects is ascribed to enhanced glucuronidation and incomplete drug absorption.

Administration, Oral↗
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↗