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K Machida

Publications and source records attributed to K Machida.

At least 163 records · Page 9Linked to original sources
PubMed1993

The relationship between the effect of biphenylcarboxylic acid analogs on glyceride synthesis and conformation.

The inhibition of biphenylcarboxylic acid analogs on glyceride synthesis was studied in association with conformation of the chemicals. Chemicals used were benzoic acid substituted with phenyl, benzoyl and phenoxy groups, phenylphenyloxyacetic acid and p-phenylacetic acid. Twist angles were calculated by a molecular orbital method. Following oral administration of p-phenylbenzoic acid to the rats for 7 days, the decrease of the triglyceride synthesized from [14C]oleic acid was observed in the adipose tissue. The in vitro inhibitions on the formation of fatty acyl-CoA thioester were examined from the influence on the hippuric acid formation from [14C]benzoic acid using the rat liver slices. In the homologous series, high inhibition was observed in para and meta substituents. None, or low inhibitions of ortho-substituted chemicals were related to the steric hindrance of the phenyl ring against carboxyl groups. This hinderance was associated with conformation and with the geometrical relationship between substituted phenyl rings and carbon atoms of carboxylic acid. In the in vitro inhibition on overall formation of diglyceride and triglyceride from [14C]glycerol, o-phenylbenzoic acid showing no inhibition on hippuric acid formation did not show inhibition. However, other ortho-substituted chemicals showed higher inhibition in comparison with the inhibition on hippuric acid formation. The inhibition of para- and meta-substituted chemicals were higher than the corresponding values of ortho substituted compounds.

Animals↗
PubMed1993

Seasonal development of Leptotrombidium pallidum (Acari: Trombiculidae) observed by experimental rearing in the natural environment.

Engorged larvae of Leptotrombidium pallidum Nagayo, Miyagawa, Mitamura & Tamiya, the vector mite of scrub typhus in Japan, were reared by feeding them with fresh eggs of the collembolan Sinella curviseta Brook while confined in small plastic containers under natural conditions in a copse. The larvae were collected from wild rodents (Apodemus speciosus) in autumn 1985 and spring 1986. Adults were kept alive for 2 yr or longer. The larvae obtained in autumn became dormant in the cold winter season, and growth recommenced in the spring. Thus, the development of mites collected in April became synchronized with that of larvae obtained in the autumn. Most larvae developed into protonymphs in May, deutonymphs in June, tritonymphs in July, and adults in August. The females laid eggs in two consecutive summers. Some larvae collected in autumn were kept in a refrigerator until the following summer. They developed into deutonymphs, tritonymphs, or adults and then became dormant in the winter. Development restarted the next spring and all became adult by summer, when the females laid eggs. Under experimental conditions, all larvae are hatched in the autumn, unlike the natural situation in which two peaks of larval occurrence on wild rodents are observed in autumn and spring.

Animals↗
PubMed1993

Aortic regurgitation: quantitation with MR imaging velocity mapping.

Aortic regurgitation (AR) in five healthy volunteers and 26 patients (mean age, 60.3 years; range, 25-83 years) was quantitatively measured with magnetic resonance (MR) imaging velocity mapping. Cine transverse images of the ascending aorta (32 phases per cardiac cycle) were acquired by using a gradient-echo sequence with a velocity-encoding bipolar pulse applied in the section-selection direction with a 1.5-T MR imaging unit. The aortic flow was calculated by integrating the product of area and mean velocity of the ascending aorta at each phase over a cardiac cycle. The negative and positive velocity values indicated antegrade and regurgitant flow, respectively, which allowed calculation of forward and regurgitant flow. Inter- and intraobserver variation of regurgitant fraction (RF) measurement was small (r = .956, standard error of the estimate [SEE] = 1.2%, n = 31; and r = .998, SEE = 0.35%, n = 10, respectively). RF determined with MR imaging agreed well with Doppler echocardiographic (n = 26) and aortographic (n = 9) grading of AR. Reproducible, quantitative, and noninvasive measurement of AR is possible with MR velocity mapping.

Adult↗
PubMed1993

A study on the values computed by dieticians and chemical analysis of fats, cholesterol, and P/S ratio in food.

Dieticians computed the fat and cholesterol contents of 11 foods that were commercially produced as ready-to-eat food from food component lists and obtained the P/S ratio (polysaturated/saturated fatty acids) from the fatty acid component list. Meanwhile the same foods were diluted and homogenized. The internal standard was combined with hepatadecanoic acid and tricaprin. The samples that had been extracted by the Folch method were analyzed for their lipid content (GC analysis using a HS-SS-10 columns for fatty acids and an OV-1 column for lipid and cholesterol). A significant positive correlation was noted between the results of dieticians' analysis and those obtained from a gas chromatographic analysis of lipid and cholesterol contents and the P/S ratio, proving that lipid analysis of food by dieticians is highly reliable. Therefore for diseases (such as hyperlipemia, arteriosclerosis, obesity, diabetes mellitus, fatty liver, and pancreatitis) in which dietary factors have a significant effect on their clinical course, dietary instructions on dietary fats based on an analysis by dieticians are considered to be effective.

Cholesterol↗
PubMed1993

Long-term results of combination chemotherapy with or without irradiation in small cell lung cancer: a 5- to 11-year follow-up.

Between April 1981 and December 1987, 148 patients with newly diagnosed small cell lung cancer (SCLC) were treated using combination chemotherapy with or without thoracic irradiation and prophylactic cranial irradiation (PCI) in a series of cooperative therapeutic trials. With a minimum follow-up of 4.7 years, 13 (9%) patients survived and were free of SCLC. These included 11 (15%) of 76 patients with limited disease and two (3%) of 72 patients with extensive disease. Three died without any evidence of SCLC (one each from second leukemia, non-small cell lung cancer, and unrelated disease). The remaining 10 (7%) patients are currently alive and free of SCLC beyond 4.7 years. Since late relapse beyond 5 years is a very rare event, these patients may have been cured. However, late toxicity of PCI must be kept in mind. Three among the 10 patients have suffered from neuropsychologic symptoms of varying degrees in severity. Although the long-term survival rate is a benchmark in the treatment of SCLC, modifications of therapy that may potentially avoid such toxicities should be considered hereafter.

Aged↗
PubMed1993

Cerebral vasodilatory capacity mapping using technetium-99m-DTPA-HSA SPECT and acetazolamide in moyamoya disease.

A cerebral vasodilatory capacity map, consisting of a 99mTc-DTPA-HSA SPECT image obtained after acetazolamide injection minus the baseline image, was produced in a patient with moyamoya disease. The map demonstrated diminished capacity in the posterior region of the right cerebral hemisphere. Subsequently, cerebral infarction occurred in the corresponding area. This observation suggests that regions of low vasodilatory capacity identified by cerebral vasodilatory capacity mapping may be at high risk of ischemic stroke.

Acetazolamide↗
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↗