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Biomedical subjects

N Kosaka

Publications and source records attributed to N Kosaka.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Clinical application of 99mTc-SQ30,217 myocardial imaging--a study of pharmacokinetics and imaging time].

99mTc-SQ30217 555 MBq (15 mCi) was intravenously injected to 6 healthy subjects to study its safety, pharmacokinetics and the imaging time. Neither side effects nor abnormalities in physical findings, hemato-biochemical tests, urinary test, etc. caused by this agent were observed in any case and its safety was suggested. Radiation dose estimates over the entire body was 4.88 mGy/1,110 MBq (0.488 rad) and that over the major organs was less than 10 mGy and they were within the allowable ranges. 99mTc-SQ30217 showed biphasic disappearance curve in blood with the half-life of alpha-phase 0.02 hour and that of beta-phase 10.14 hours. 99mTc-SQ30217 was considered to show characteristic pharmacokinetics in that the myocardial accumulation was high in an early stage of the administration, but it rapidly decreased. Both heart to liver ratio and heart to lung ratio were high within 10 minutes, but they decreased after 15 minutes. As a result of SPECT imaging of 4 patients with ischemic cardiac disease, the images obtained with 99mTc-SQ30217 at an early period after the administration was as good as those with 201Tl and the appearance of defects in the images with both agents was similar. 99mTc-SQ30217 was considered to be sufficiently useful as a 99mTc-labelled agent for myocardial blood flow.

Adult↗
PubMed1991

Noninvasive method to obtain input function for measuring tissue glucose utilization of thoracic and abdominal organs.

We have developed a method for the noninvasive estimation of regional tissue glucose utilization in humans that employs positron emission tomography (PET) and 2-(18F)fluoro-2-deoxy-d-glucose (FDG). Unlike other methods, the input function used in this method is obtained from the corrected time-activity curve of the descending aorta, not the left ventricle, because the descending aorta is relatively free of spillover from other organs and extends from the upper thorax to the lower abdomen. With this method the time-activity curve of the descending aorta must be corrected for the partial volume effect and the difference in counts between plasma and whole blood. Using the noninvasively obtained input function, regional tissue glucose utilization was calculated by Patlak graphic analysis. k1k3/(k2 + k3) was in good agreement with k1k3/(k2 + k3) calculated from the plasma input function by arterial sampling (r = 0.9995). These results suggest that the input function and regional tissue glucose utilization (not only of myocardium but also of other thoracic and abdominal organs) can be determined noninvasively.

Abdomen↗
PubMed1989

Augmentation of the gastric mucosal defense mechanism induced by KW-5805, a novel antiulcer agent.

KW-5805 (a new antiulcer agent), given p. o. at 30 mg/kg to rats, significantly increased the amount of gastric adherent mucus and mucosal glycoproteins. Gastric mucosal glucosamine synthetase activity was significantly enhanced by KW-5805 (30 mg/kg, p. o.). KW-5805 (10, 30 mg/kg, p. o.) significantly suppressed the decrease of gastric mucosal blood volume and oxygen sufficiency induced by hemorrhagic shock. The agent also significantly inhibited the extravasation of Evans blue into the gastric mucosa after ischemia-reinfusion. In conclusion, KW-5805 increased biosynthesis, storage and secretion of gastric mucus and improved the gastric mucosal hemodynamics.

Animals↗
PubMed1989

[Cardiac response during various activities in patients with ischemic heart disease evaluated by an ambulatory ventricular monitor (VEST)].

To assess the cardiac response to various exercise in ischemic heart disease (IHD), left ventricular function was continuously measured with an ambulatory ventricular monitor (VEST) in 3 normal subjects and 15 IHD patients. Treadmill exercise (early stage (E1), end stage (E2) and recovery standing state (RE], walking (WK) and climbing stairs (CS), was used for exercise. 15 IHD patients were divided into 4 groups by the LVEF response to treadmill exercise. In group 1 (G1), LVEF increased gradually at stage 1 and became plateau from stage 2 to end stage like normal group. In group 2 (G2), LVEF increased at stage 1 and became plateau from stage 2 but decreased from maximal EF more than 5% at end stage. In group 3 (G3), LVEF increased only at stage 1 and decreased immediately after stage 1 to end stage. The decrease of LVEF at end stage from standing was more than 5%. In group 4 (G4), LVEF decreased at stage 1 and became minimum at end stage. This grouping was well related to thallium redistribution (Tl RD) score and coronary arteriography (CAG) score. We could predict the severity of coronary artery disease from this grouping because all group 3 or 4 patients had severe coronary artery disease. VEST was useful for the evaluation for the tolerance to daily activities. Group 1, 2 and 3 tolerated daily activities while group 4 could not always. The degree of the increase in cardiac output during ischemia evaluated by VEST may be one of the useful index of the tolerance to exercise. In conclusion VEST was very useful for evaluating cardiac capacity of ischemic heart disease patients during various exercise.

Coronary Disease↗
PubMed1989

[N-isopropyl I-123 p-iodoamphetamine (IMP) brain SPECT in Alzheimer's disease].

Eighteen patients with Alzheimer's disease (AD), 5 patients with Pick disease (PD), 6 patients with other types of degenerative dementia (O) and 12 age-matched normal control subjects (N) were studied using N-isopropyl p-[I-123]iodoamphetamine (I-123 IMP) with SPECT. Regional to cerebellar activity (R/CE) ratio and frontal to parietal (F/P) activity ratio were evaluated in each case. I-123 IMP-SPECT revealed focal abnormality in all cases in AD, PD, O group, while XCT and/or MRI were normal or showed cerebral atrophy without focal abnormal density or intensity. In AD group, R/CE ratio in all the regions except for bilateral Rolandic area and left primary visual cortex were significantly lower (p less than 0.05 or p less than 0.01) than that in N group, and F/P ratio were significantly higher (p less than 0.01) than that in P and O group. In conclusion, I-123 IMP-SPECT is useful to detect focal perfusion abnormality in dementia and may be of value in differentiating Alzheimer's disease from dementia of non-Alzheimer type.

Aged↗
PubMed1987

[A cooperative group study of clinical efficacy of the liver SPECT].

The purpose of this study is to evaluate the clinical efficacy of the liver SPECT about detectability of SOLs (space occupying lesion). The images were interpreted with the planar scintigram (PS) only and combination of PS and SPECT (single photon emission computed tomography) by 11 physicians. Changes of false positive and false negative rate were calculated to evaluate the influence of the diffuse parenchymal liver disease and the localization of the SOLs. Addition of SPECT to PS in the cases who are suspected SOLs is effective in right hepatic lobe (right anterior and posterior segment) to detect the SOLs, but not effective in left lateral segment. Addition of SPECT to PS in the cases with diffuse parenchymal liver disease and SOLs increases the false positive rate.

Chronic Disease↗
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↗