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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Clinical features of intestinal tuberculosis].

We had tuberculosis infection cases of gastrointestinal tract diagnosed histopathologically during January 1980 to December 1991 in Tokyo National Chest Hospital. There were 12 cases (male 8, female 4) from 24 y.o. to 88 y.o. (mean 50 y.o.). We got histopathological specimen by operation (6 cases), biopsy (4), and section (2). Pulmonary tuberculosis was complicated in 8 cases, 7 cases had cavity formation and another case was miliary tuberculosis. Distribution of tuberculous lesion was colon (7 cases), small intestines (5), cecum (2), rectum (1) and esophagus (1). First symptom was mainly abdominal symptom such as abdominal pain and diarrhea. There were a perforative peritonitis and a intestinal obstruction during chemotherapy. Three died cases complicated low albuminemia. We suppose that serum albumin is one of the useful marker of patient's prognosis.

Adult↗
PubMed1993

[Current state and problems in the microbiology laboratory--organizing the laboratory].

The microbiological laboratory in the hospital has many roles including the rapid and precise identification of pathogenic bacteria in specimens, their antimicrobial susceptibility tests, microbial antigen detection using immunological methods and DNA hybridization methods, surveillance of bacterial milieu of the hospital environment, monitoring quality control of microbiological methods, to educate microbiological skills of staffs, the economical management of laboratory and so on. The last two issues are our major concerns. Improvement of the microbiological skills of the staff is most important in the laboratory, but is a time-consuming. From our experience, a technical expert, intermediately skilled technicians and beginners should always work in the laboratory, together. On the other hand, the economical management of the microbiological laboratory is also another concern. Although the mechanization of procedures comes to mind, it is hard to improve the economical conditions in the laboratory. Because of the control of the machines is not completely automatic and requires the knowledges and decisions of technical experts, the work force and running cost can not be reduced. As the technical expert can economize in the use of media or tests for identification of pathogens, good training of beginners into skillful successors, is important.

Humans↗
PubMed1993

[Dual-energy data acquisition for simultaneous 81mKr ventilation/99mTc-MAA perfusion SPECT: ventilation/perfusion ratio mapping in cross section].

Methods of simultaneous pulmonary ventilation/perfusion (V/Q) tomogram (SPECT) for V/Q ratio mapping were reported. Crosstalk was corrected by subtraction assuming crosstalk/signal ratio is constant for an individual examination. Crosstalk was reduced by 85% for that of 99mTc-to-81mKr window (R12), and by 83% for that of 81mKr-to-99mTc window (R21) in a phantom experiment. The R12 and R21 were 1.0-1.9% (mean 1.3%) and 34.6-55.3% (mean 41.9%), respectively in 9 patients (mean age, 56.1 years; range, 38-82 years). V/Q SPECT was undertaken in 7 of the 9 patients. 99mTc-macroaggregated albumin (185 MBq) was injected intravenously in supine position, and 81mKr gas was administered continuously during the SPECT data acquisition. Sixty-four 64 x 64-matrix (size = 8 mm/pixel) images, 20-second acquisition time for each, were collected by a rotating gamma camera in a step-and-shoot fashion during a 360-degree rotation with the two photopeaks, one at 140 keV for 99mTc and another at 190 keV for 81mKr. Examination time was about 40 minutes, and the V/Q ratio maps in cross section were obtained in all of the examinations.

Adult↗
PubMed1993

[Radionuclide studies of atherosclerosis].

New Tc-99m-labeled brain perfusion imaging agents, such as Tc-99m-HMPAO, and Tc-99m-ECD, are developed and expected to improve the clinical study of cerebral perfusion disturbance due to arteriosclerosis. They enable us better images than I-123-IMP and more accurate diagnosis. Similarly, in the field of cardiovascular nuclear medicine, new Tc-99m-labeled compounds, Tc-99m-MIBI, Teboroxime and Tetrofosmin are available. Furthermore, I-123-MIBG, a tracer taken up in presynaptic adrenergic vesicles, and I-123-BMIPP, a new agent developed for the evaluation myocardial fatty acid metabolism, will mark a new epoch in the study of coronary sclerosis. In order to image atherosclerosis directly, In-111-polyclonal immunoglobulin G, Tc-99m-low density lipoprotein etc., are under investigation.

Amphetamines↗
PubMed1993

[Comparison between 180 degrees and 360 degrees data collection in 99mTc-Tetrofosmin SPECT of the myocardium].

We compared 360 degrees data collection technique with 180 degrees technique in SPECT using a new myocardial perfusion imaging agent, 99mTc-Tetrofosmin. Eight patients were examined at stress and at rest on separate days. Following the injection of 555 MBq 99mTc-Tetrofosmin, 64 views of 15 sec each were collected during a 360 degrees rotation, and 32 views of 30 sec each during a 180 degrees rotation. The 180 degrees data collection provided superior images in sharpness in 14 of 16 scans. The interpretation was concordant in 123 of 128 regions (96.1%), and hypoperfusion was considered to be underestimated in 5 regions using the 360 degrees technique. It was suggested that the 180 degrees data collection technique is more effective in myocardial SPECT employing 99mTc-Tetrofosmin than the 360 degrees technique.

Aged↗
PubMed1993

[Clearance of 99mTc-Tetrofosmin from the myocardium and the adjacent organs].

We studied clearance of a new myocardial perfusion imaging agent, 99mTc-Tetrofosmin, from the myocardium and the adjacent organs in nine patients. 99mTc-Tetrofosmin was injected intravenously at stress and at rest, and SPECT images were obtained 25 min and 120 min later. Anterior view images were also obtained 10 min and 150 min after the injection to compare the myocardial clearance with those from the liver and lung. Clearance from the liver was faster than those from the myocardium and lung. Washout rate calculated with SPECT was higher for the inferior wall than for the anterior wall and lateral wall (p < 0.05 at rest, N.S. at stress). The value was higher at stress in any region than at rest (the anterior wall and lateral wall, p < 0.01; the septum, p < 0.05; the inferior wall, N.S.). Washout rate for the anterior wall was 3.4 +/- 14.0% at rest and 18.0 +/- 10.6% at stress. The rate for the lateral wall was 2.7 +/- 22.5% at rest and 15.8 +/- 7.9% at stress. It was suggested that rapid hepatic clearance and high myocardial washout at stress may be important in determining the period between the injection of 99mTc-Tetrofosmin and the data acquisition for SPECT imaging.

Female↗
PubMed1992

[Two-dimensional time-of-flight MR angiography of mediastinum and pulmonary hilar vessels: initial clinical experiences].

Two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of mediastinal and pulmonary hilar vessels was performed in 10 patients, seven men and three women with a mean age (range) of 65.7 (48-88) years. The rate of visualization of the vessels and the diagnostic ability of 2D TOF MRA were assessed in comparison with contrast-enhanced CT. A radiofrequency-spoiled gradient echo sequence (SPGR) was used during repeated breath-holding (8-27 seconds) in coronal (8 patients) and axial (2 patients) imaging planes on a 1.5 Tesla superconducting scanner under the following conditions: repetition time/echo time/flip angle/excitation: 25-33/7-8 ms/45 degrees/1, field-of-view: 30 x 30 cm, slice thickness: 2.5 mm, 32 slices, 256 (frequency) x 192 (phase) matrix, with gradient moment nulling technique. Visualization sufficient to enable diagnosis of the vascular lesion was obtained in 95 (52%) vessels, mere visualization in 63 (35%), and non-visualization in 24 (13%) of the 182 evaluable vessels. The rates of good visualization of pulmonary hilar vessels (26/86, 30%) and veins (26/48, 54%) were significantly lower than that of arteries (43/48, 90%, p < 0.05). The sensitivity and specificity of 2D TOF MRA were 77% (10/13) and 100% (83/83), respectively, in 96 evaluable vessels of nine patients. 2D TOF MRA of mediastium and pulmonary hili is clinically feasible, and may be useful because of its high specificity.

Aged↗
PubMed1992

Lack of effect of islet amyloid polypeptide on hepatic glucose output in the in situ-perfused rat liver.

Islet amyloid polypeptide (IAPP), a novel peptide isolated from islet amyloid deposits in patients with insulinoma and non-insulin-dependent diabetes mellitus (NIDDM), has been reported to be cosecreted with insulin from pancreatic beta cells and to inhibit glucose uptake and glycogen synthesis in muscle tissue in vitro. We investigated the effects of the synthesized, rat-amidated form of IAPP on hepatic glucose output, and IAPP extraction, using an in situ flow-through perfusion system in rats to elucidate the actions of IAPP on the liver. The IAPP (10(-8) mol/L) alone had no effects on the hepatic glucose release. Infusion of 6 x 10(-11) mol/L glucagon alone resulted in an expected elevation in glucose production (30.0 +/- 1.7 mumol/35 min/g liver). Insulin (3 x 10(-10) mol/L) submaximally decreased the glucagon-stimulated glucose production to 73% (from 30.0 +/- 1.7 to 22.0 +/- 1.4 mumol/35 min/g liver; n = 7, P less than .01). A simultaneous infusion of 10(-8) mol/L IAPP did not influence the glucagon-stimulated glucose production (27.6 +/- 1.2 mumol/35 min/g liver) or the insulin-dependent inhibition of glucagon-stimulated glucose production (22.6 +/- 1.3 mumol/35 min/g liver). IAPP extraction by the liver in a single passage was minimal, in contrast to approximately 50% hepatic insulin extraction. These results indicate that IAPP does not play any important role in modulating glycogen metabolism in the liver.

Amyloid↗
PubMed1992

Molecular-resolution images of aspirin crystals with atomic force microscopy.

The atomic force microscope was developed in order to image arrays of molecules on the (001), (100) and (011) faces of aspirin crystals in water. Lattice spacings and symmetries of methyl groups and the part of the phenyl groups on the (001) face in water are consistent with X-ray diffraction data. Surfaces of the (100) face that show the best-developed cleavage, in general, are difficult to image. Although the lattice constant derived from (100) image is consistent with the X-ray diffraction data, the c-glide plane symmetry is lost and diffused spots are observed that are 1.8-3.1 times more elongated than (001) spots. It is not possible to image the (011) surface. This initial success in imaging the molecular crystal surfaces of drug compounds has clarified the different submolecular structures of the three different crystal faces, and the close relationship between the imaging difficulties and the differences in the dissolution process in water.

Aspirin↗
PubMed1992

Value of three-dimensional surface display of brain perfusion imaging. Comparison with tomographic imaging.

The diagnostic ability of a three-dimensional surface display of I-123 IMP brain scintigrams and tomographic images was compared in 12 patients who underwent I-123 brain tomography for cerebral cortical hypoperfusion. Foci of decreased accumulation were independently diagnosed by four radiologists, first with transaxial images, second with three-dimensional images, and finally with both images subjectively compared for the purpose of diagnosing the existence, localization, and extent of lesions. Six different lesions (0 to 3 lesions/radiologist) were found only on the transaxial images, but 30 different lesions (1 to 14 lesions/radiologist) were found on the three-dimensional images. In 9 out of 12 cases, the three-dimensional images were regarded as superior for evaluating the extension of the lesion and for lesion existence and lesion localization in 5 out of 12 (P less than 0.05). In conclusion, a three-dimensional display of an I-123 IMP brain tomogram is superior to tomographic images in diagnosing the extent of cerebral cortical hypoperfusion. However, the display is not superior to tomographic images for diagnosing the existence and localization of hypoperfusion.

Amphetamines↗
PubMed1992

[Conditions for low-intensity voluntary wheel running in rats and its chronic effects on health indexes].

Studies were undertaken to evaluate the fundamental conditions for a low-intensity voluntary wheel running model in rats and its chronic effects on health indexes. Male Fischer rats (SPF) 5 weeks of age were housed in individual sedentary conditions or in individual wheel-cage units which allowed free access to voluntary wheel running for 8 months. Voluntary running averaged 640 +/- 198 m/day, reached a peak (965m) at the 2nd month and waned over time, reaching a plateau after the 6th month (about 400-500m). Exercising rats consumed more food (+23%), but exhibited decreased body weight gains (-9%), suggesting a remarkable lowering of fat. A lowering effect on resting blood pressure (-5%) was also recognized. In addition, preventive effects on oxygen toxicity and effective bactericidal activity of neutrophils and pulmonary alveolar macrophages (PAM) were suggested. Although the amount of exercise in this study was the smallest of the other preceding ones conducted with a voluntary wheel running model, many potential health benefits were recognized. Such health promoting and protective effects by low-intensity voluntary exercise and the harmfulness of forced exercise in rats have been reported in researches on cancer, lowering fat and hypertension. Therefore it is important to set up conditions for low-intensity voluntary running. It was also demonstrated by this study that strictly controlled environmental conditions, such as room temperature and humidity, a 12-hr light-dark cycle and prevention of infection and psychological stress to rats, as well as using male rats, which are more inactive, were important factors to establish this model.

Animals↗
PubMed1992

[Recent technical advances in portable oxygen delivery systems].

According to a Japanese national survey (June 30, 1990), the number of patients receiving home oxygen therapy (HOT) has been greater than 18,000 since March 1985, when HOT was first covered by health insurance. The oxygen concentrator, especially the molecular sieve type, is the most common method of delivery (more than 90%). In April 1988, the portable oxygen cylinder was acknowledged by health insurance, and the liquid oxygen supply system in April 1990. Three types of portable oxygen delivery systems are available; oxygen cyclinder, liquid oxygen system, and oxygen concentrator (membrane type), of which the oxygen cylinder is most commonly used. In our hospital, portable oxygen supply systems were used in 80% of 168 HOT cases in 1990, and the use of 400 L aluminum oxygen cylinders at a flow rate of 1-2 L/min has been most popular. There is an strong desire from patients for lighter portable oxygen supply system of longer duration. In 19 patients with chronic respiratory failure, we evaluated a newly designed demand oxygen delivery system (DODS), which weighs 2.4 kg including the DOD device (TER-20 Teijin), 1.1 L oxygen cylinder made of ultressor, nasal cannula, and carrier. Arterial blood gases at rest (room air) were PaO2 61.9 +/- 6.3 torr, PaCO2 63.8 +/- 9.4 torr and pH 7.40 +/- 0.04. A crossover trial was performed under three conditions; breathing room air with no weight, and pulse oxygen flow and continuous oxygen flow each carrying 2.4 kg of weight. Both 6 minute walking (E1) and walking on a slow speed treadmill (E2) were studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1992

Molecular analysis of genetic mutation in electrophoretic variant of human lactate dehydrogenase-A(M) subunit.

An electrophoretic variant of lactate dehydrogenase-A (M) subunit was discovered in a patient with multiple myeloma. DNA analysis of the variant allele revealed a nucleotide substitution (transition) of C to T at codon 314 (CGT-TGT), and this mutation resulted in the replacement of an arginine by a cysteine (R314C). This amino acid replacement affects the net charge of the subunit and makes the LDH-A variant have a faster electrophoretic mobility. The responsible missense mutation created a new restriction site, AGGCCT, which can be simply detected by endonuclease AatI digestion. In addition, four synonymous substitutions with no amino-acid replacements were found at codons 51, 119, 163 and 175 in the LDH-A gene from the patient.

Aged↗
PubMed1992

[A case of meningioma with non-accumulation of 99mTc-ECD and increased accumulation of 99mTc-HMPAO in the tumor].

99mTc-ECD SPECT and 99mTc-HMPAO SPECT with or without Matas test were performed in a 62-year-old woman with meningioma in the left anterior cranial fossa. After injection of 740 MBq 99mTc-ECD or HMPAO, 64 projection images were collected with a rotating Gamma camera. Matas test was carried out by compressing the left common carotid artery for about one minute immediately after RI injection. Although 99mTc-ECD SPECT showed non-accumulation in the tumor, 99mTc-HMPAO SPECT demonstrated increased accumulation in it. This area of increased accumulation disappeared on 99mTc-HMPAO SPECT with Matas test which causes decrease in blood flow of the tumor. These findings suggest 99mTc-ECD and 99mTc-HMPAO have a different mechanisms of accumulation in the meningioma.

Cysteine↗
PubMed1992

[Three-dimensional display of 99mTc-MIBI myocardial scintigraphy].

One of 99mTc-hexakis, 99mTc-methoxyisobutyl isonitrile (MIBI), has been demonstrated to have a myocardial uptake proportional to regional coronary blood flow. In this study, 99mTc-MIBI myocardial scintigraphy were performed for 16 patients with ischemic heart disease. After injection of 740 MBq of 99mTc-MIBI, 64 projection images were collected during a 360-degree rotation. Three-dimensional (3D) display of the left ventricle was reconstructed with depth-shading method from 99mTc-MIBI SPECT images, which were reconstructed by filtered back projection method. In 9 of the patients, left ventricular cineangiography were performed as diagnostic gold standard. Four physicians blinded to patients' clinical informations interpreted 3D images and SPECT images on separate occasions. Diagnosis of hypoperfusion by 3D displays agreed with those of SPECT in 92.9% (104/112 segments), and disagreed in 7.1% (8 segments). Sensitivity and specificity of 3D images were 87.0 and 93.9%, which were not statistically different (p less than 0.05) from that of SPECT images (91.3, 97.0%). Receiver operating characteristic (ROC) analysis revealed nearly identical curves for the two. Although 3D display had nearly identical diagnostic ability with SPECT, observers reported that 3D images were easier to diagnose than SPECT images. An advantage of the 3D display is that the display gives a more realistic impression of the left ventricle to an observer than tomography or planar imaging. Another advantage is that 3D display can reduce the amount of data storage compared with that of SPECT. In conclusion, 3D images may be useful for diagnosis of hypoperfusion of left ventricle.

Adult↗
PubMed1992

[Application of laser in the treatment of spontaneous pneumothorax and emphysema].

From August 1990 to August 1991, sixteen patients with bullae or blebs (pneumothorax 9, giant bullae 5, bullous emphysema 2) were treated by CO2 laser ablation under limited thoracotomy. We found the irradiation of bullae or blebs by CO2 laser quite effective in eliminating these bullous lesions which were often multiple and inoperable by conventional methods. Histological examination revealed the wall of bullae where CO2 laser was applied became thick with dense fibrous tissues and degenerated collagen fibers which, however, were not disrupted. The procedure was safe and we were able to operate patients with disabling emphysema. Because CO2 laser can penetrate only 0.2-0.3 mm of tissue thickness, it is suitable for the ablation of bullous lesions which have thin walls and rapidly shrink and collapse by irradiation leaving thick walled scar tissues. Removing multiple bullae and blebs in patients with bullous emphysema can improve gas exchange by reducing dead spaces and elevating the diaphragm which is often flat and downward displaced because of hyperinflation in these patients. We are planning to incorporate thoracoscopy for this operation to make the procedure less invasive.

Adolescent↗