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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 19 recordsLinked to original sources
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↗
PubMed1991

Structure of benzyloxycarbonyl-L-isoleucyl-L-alanyl-alpha- aminoisobutyryl-alpha-aminoisobutyrate methyl ester, Z-L-Ile-L-Ala-Aib-Aib-OMe.

C26H40N4O7, Mr = 520.6, tetragonal, P4(3)2(1)2, a = 10.433 (1), c = 54.476 (7) A, V = 5930 (1) A3, Z = 8, Dm = 1.155 (3), Dx = 1.166 Mg m-3, lambda (Cu K alpha) = 1.54178 A, mu = 0.665 mm-1, F(000) = 2240, T = 295 K, R = 0.057 for 2037 observed reflections. The tetrapeptide adopts a type II beta-turn conformation with an extremely weak 4----1 intramolecular hydrogen bond [3.479 (7) A]. The molecules are held together in the crystal by three kinds of N-H---O intermolecular hydrogen bonds.

Amino Acid Sequence↗
PubMed1991

[Developmental changes in normal images of 123I-IMP brain SPECT in young children].

In an attempt to determine the normal evolution of N-isopropyl p-I-123-iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT), we selected 12 children (an age range of 1 month-3 year) who were diagnosed as normal in follow-up between 6 month-3 year by neurological examination, X-ray computed tomography, electroencephalography and 123I-IMP SPECT in our 78 cases. SPECT of the brain was performed 30 minutes after intravenous administration of 74 MBq (2 mCi) 123I-IMP using a rotating gamma camera equipped with a 30-degree slant-hole collimator. In neonates, a predominant activity was observed in the basal ganglia and thalamus, with only slight parietal and occipital activity. Frontal cortex was barely recognizable. Under 1 year, cortical activity was gradually increased and clearly visible. After 1 year, SPECT images were similar to those of adult. In conclusion there was an important modification of the regional perfusion pattern in relation to brain maturation.

Amphetamines↗
PubMed1991

An evaluation of ovarian carcinoma-associated antigen defined by murine monoclonal antibody CF511 in sera from patients with ovarian carcinoma.

Murine monoclonal antibody CF511, raised against human ovarian clear cell carcinoma, detects a glycoprotein (Mr 600 kDa) called CF511 antigen which is elevated in the serum of many patients with ovarian carcinoma. A competitive enzyme-linked immunosorbent assay was developed to detect CF511 antigen in human serum and used to detected CF511 antigen in subjects with ovarian carcinoma and other diseases. No raised levels (less than 18 unit (U) ml-1) of the antigen were found in the serum of 220 normal individuals or of patients with germ cell tumours (n = 6), granulosa theca cell tumour (n = 1), gastric carcinomas (n = 10) and colo-rectal carcinomas (n = 8). Raised serum levels of CF511 antigen were found in 6/46 patients (13.0%) with benign gynaecological tumours (including endometriosis or ovarian cyst), in 5/7 patients (71.4%) with breast carcinoma and 16/21 (76.2%) lung carcinoma patients. In patients with ovarian carcinoma, 42.3% (11/26) of stage I and II, and 96.0% (24/25) of stage III and IV had levels of greater than or equal to 18 U ml-1. In all patients with serial determination of CF511 antigen levels before and after the surgery, the levels of antigen correlated with the clinical course of disease. Determination of CF511 antigen levels may be useful for detection of ovarian carcinoma as well as lung and breast carcinomas and for monitoring progress of disease and response to therapy.

Antibodies, Monoclonal↗
PubMed1991

Gallium scintigraphy in neoplastic angioendotheliosis of the lung.

A case of neoplastic angioendotheliosis of the lung is reported. A 56-year-old man presented with a 2-month history of fever, increased serum lactic dehydrogenase, and arterial hypoxemia. Chest radiography revealed diffuse reticulonodular opacity, whereas CT scanning showed diffuse small nodular areas of increased attenuation with indistinct borders. Diffuse pulmonary uptake of Ga-67 was noted in scintigraphy. Combination chemotherapy designed for lymphoma induced a remission of the disease.

Gallium Radioisotopes↗
PubMed1991

Cinematic three-dimensional surface display of cardiac blood pool tomography.

A method of three-dimensional cinematic display (3D cine) of cardiac blood pool tomography is described. ECG-gated transaxial blood pool imaging was obtained from a set of projection images that were collected from 32 images with 10 ECG-gated images per projection during a 180 degrees arc of a rotating gamma camera. A surface contour of the blood pool was determined by a set of isocount lines (40-55% of the maximum pixel counts) of the transaxial images. 3D cine was made by a depth-shading method, in which brightness of a given point on the contour was set proportional to the distance between the viewing plane and the point and to the incident angle formed by the viewing line and the surface of the point. In 15 patients, 3D cine showed hypokinesia, akinesia, dyskinesia, ventricular aneurysm, and opposite motions of the atria and ventricles. Diagnoses of left ventricular motion by 3D cine agreed well with those by echocardiography and contrast left ventriculography.

Aged↗
PubMed1991

Atomic force microscope images of the surfaces of aspirin crystals at submolecular resolution.

The atomic force microscope has been developed and used to image arrays of molecules at the (001) and (100) faces of aspirin crystals in water and in air. Lattice spacings composed of methyl groups and the part of the phenyl groups on the surface of the (001) in water, are consistent with X-ray diffraction data. The surface of (100) face which shows most perfect cleavage in bulk, is more difficult to image. This initial success in imaging at drug crystal surfaces clarified the different structural behavior at the submolecular level for three crystal faces, and the close relationship to the differences in the dissolution velocity.

Aspirin↗
PubMed1991

Phase II study of ifosfamide, cisplatin, and vindesine combination in advanced non-small cell lung cancer.

Twenty-seven previously untreated patients with unresectable non-small cell lung cancer were treated with a 3-drug combination of ifosfamide, cisplatin, and vindesine as a phase II study. Patients received ifosfamide, 1.3g/m2, on days 1 to 5; cisplatin, 20mg/m2, on days 1 to 5; and vindesine, 3mg/m2, on days 1 and 8; with a sufficient parenteral hydration. Courses were repeated every 4 weeks. Twenty males and seven females with a median age of 61 years were treated and fully evaluated. Five patients had stage IIIA, seven had stage IIIB, and 15 had stage IV disease. One patient with adenocarcinoma achieved a complete response and 16 achieved a partial response, for an overall response rate of 63% (95% confidence limit: 45% to 81%). The median duration of response was 34 weeks (range: 9 to 52 weeks). The median survival time was 58 weeks for patients with IIIA/B disease, and 33 weeks for those with IV disease. The major toxicity was myelosuppression, however, it was generally well-tolerated. These results indicate that the 3-drug combination is active against non-small cell lung cancer and warrants further clinical trials.

Adult↗