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M Ohkawa

Publications and source records attributed to M Ohkawa.

At least 37 records · Page 2Linked to original sources

[A case of ectopic pulmonary calcification appearing as diffuse ground-glass attenuation on HRCT].

A 50-year-old man was admitted to undergo an operation for aortic stenosis and insufficiency. Chest high-resolution CT (HRCT) showed diffuse areas with ground-glass attenuation in both lung fields. The shadows were not seen in the periseptal zones. A transbronchial lung biopsy specimen revealed ectopic interstitial calcification. Differential diagnosis upon observation of diffuse areas with ground-glass attenuation on HRCT included hypersensitivity pneumonitis and bronchopneumonia. In the peripheral region of the secondary pulmonary lobules, the microchemical environment of the alveoli tended to become alkalosed in comparison with the central area, the characteristic distribution of the areas of ground-glass attenuation may be explained by the differentiation of the acid-base balance between the peripheral and central regions of the secondary pulmonary lobules.

Calcinosis↗

[Comparison of 133Xe gas dynamic SPECT and thin-section CT in patients with pulmonary emphysema].

PURPOSE: We assessed 133Xe gas dynamic single photon emission computed tomography (SPECT) by comparing washout axial images with thin-section CT (TSCT) in patients with pulmonary emphysema. METHODS: Twenty-three patients were studied. All patients were diagnosed as having pulmonary emphysema on the basis of TSCT. We compared TSCT of upper, middle and lower lung fields with 133Xe gas dynamic SPECT axial images at the corresponding levels during the 3 to 4 minutes of washout phase. If the degree of 133Xe gas retention or TSCT finding of ventral and dorsal parts was not the same, the images were divided into two parts. RESULTS: A total of 174 lesions in 23 cases were examined, but 3 lesions having no retention of 133Xe gas at equilibrium phase were excluded. The results showed that: there were 37 lesions (21.6%) with equivalent severity on both images; there were 42 lesions (24.5%) with more severity on 133Xe gas dynamic SPECT than on TSCT; and there were 92 lesions (53.8%) with more severity on TSCT than on 133Xe gas dynamic SPECT. The severity on 133Xe gas dynamic SPECT and TSCT was not always compatible. One of the reasons for the variable 133Xe gas retention even when the lesion had the same severity on TSCT, may be bronchial stricture which cannot be seen on TSCT. CONCLUSION: By comparison of axial images of 133Xe gas dynamic SPECT with CT images, we could recognize the areas of 133Xe gas retention in detail. Results suggest that 133Xe gas dynamic SPECT can be useful to identify ventilation impairment in pulmonary emphysema.

Aged↗

Cloned transgenic mouse fetuses from embryonic stem cells.

Development of efficient efficient system for genetic modification and large-scale cloning of livestock is of importance for agriculture, biotechnology, or human medicine. The mouse, on the other hand, is an ideal model in the basic studies of genetic modification. In this study, we investigated about production of clone mice from established embryonic stem (ES) cell line by nuclear transfer. Further, we had try of production of cloned transgenic mouse fetuses/offspring using ES cells modified with a marker gene, EGFP. With the ES cell line TT2 which is at least 15 passages, reconstructed oocytes developed to 2-8 cell embryos, morulae, or blastocysts (44.8%), and 17.2% of them developed to term (19.5 days post-coitum, dpc). When 40 embryos with the marker gene transferred to 11 surrogate mothers (pseudopregnant females), 5 live fetuses were recognized in the uteli at 13.5 dpc and in these fetuses expression of GFP was observed, but none developed beyond 19.5 dpc. The present results suggest that ES cells can be used tg produce cloned mice.

Animals↗

Cloned murine fetuses produced by nuclear transfer using metaphase-arrested embryonic stem cells.

We examined whether metaphase nuclei could be used as nuclear donors in nuclear transfer in mice. The reconstructed embryos were developed to fetuses in both the metaphase-nuclear transfer and the G1-nuclear transfer. We also performed enucleation of oocytes following nuclear injection (injection-enucleation method) using microinjection method with a piezo-driven micromanipulator in order to produce the cloned murine fetuses. We found that this method could shorten time for manipulation in comparison with the conventional method performing nuclear injection following enucleation of oocytes (enucleation-injection method). We produced successfully cloned fetuses by the injection-enucleation method. Furthermore, there was no difference of developmental efficiency in reconstructed embryos from between B6D2F1 and ddY strain as oocyte donor.

Animals↗

Evaluation of radiotherapeutic response in non-small cell lung cancer patients by technetium-99m MIBT and thallium-201 chloride SPET.

The purpose of this study was to investigate the relationship between technetium-99m hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) accumulation in tumours and response to radiotherapy in non-small cell lung cancer patients in comparison with the findings obtained using thallium-201 chloride (201Tl). Simultaneous dual single-photon emission tomography (SPET) imaging with 600 MBq 99mTc-MIBI and 111 MBq 201Tl was performed in 31 patients with biopsy- or sputum cytology-proven lung cancer. SPET images were acquired 15 min (early) and 2 h (delayed) after injection, and the early ratio, delayed ratio and retention index were measured. The tumours were classified into two groups on the basis of follow-up computed tomography (CT): responders (at least 50% reduction in tumour size) and non-responders (little or no change in tumour size). The mean (+/-SD) values of early ratio, delayed ratio and retention index using 99mTc-MIBI SPET were 3.0+/-1.1, 2.7+/-1.0 and -9.5+/-12.7, respectively, in responders and 2.4+/-0.7, 2.0+/-0.5 and -18.4+/-9.0, respectively, in non-responders. The corresponding values using 201Tl chloride SPET were 3.7+/-1.0, 4.7+/-1.5 and 24.2+/-22.1 in responders and 3.3+/-1.2, 4.0+/-1.3 and 20.4+/-20.5 in nonresponders. Using 99mTc-MIBI, the delayed ratio and retention index in responders were significantly higher than those in non-responders (P<0.01 and P<0.05, respectively). The results of this study indicate that patients with higher delayed ratio and retention index values using 99mTc-MIBI SPET are likely to respond better to radiotherapy than those with lower values. 99mTc-MIBI SPET may give an indication of the short-term response to radiotherapy in patients with non-small cell lung cancer.

Adult↗

Cerebral aneurysm associated with an anomalous hyperplastic anterior choroidal artery.

An unruptured internal carotid artery (ICA) aneurysm arising at the origin of a hyperplastic anomalous AchoA was identified together with a second unruptured middle cerebral artery aneurysm during angiography performed to investigate a striatal and intraventricular haemorrhage in a 55-years-old woman. The anomalous hyperplastic AchoA supplied the left temporal and occipital lobes, and the aneurysm arose proximal to its origin. The patient underwent clipping of the aneurysms, and intra-operative observation revealed that several perforating branches arose directly from the ICA between the AchoA and the ICA bifurcation.

Carotid Artery Diseases↗

Anticonvulsant-induced suppression of IFN-gamma production by lymphocytes obtained from cervical lymph nodes in glioma-bearing mice.

It is well known that phenytoin can cause impairment of cellular immunity. The authors investigated the potential role of other anticonvulsant drugs in the development of antitumor immunity in murine malignant glioma models. The survival rate was determined in murine glioma models using syngeneic 203 glioma cells following treatment with four anticonvulsants, which are most commonly administered to glioma patients, i.e., phenytoin, phenobarbital, valproate and zonisamide. In a second set of experiments, we further examined the effect of these drugs on interferon-gamma (IFN-gamma) secretion by lymphocytes prepared from cervical lymph nodes (CLN) in the same models. The IFN-gamma production of CLN lymphocytes as measured by ELISA method was markedly impaired in the early stage of tumor-bearing mice treated with phenytoin or zonisamide, and the median survival time (MST) of controls and of mice treated with either phenytoin or zonisamide was 13, 10 and 11 days, respectively, which was not a statistically significant difference. Phenobarbital and valproate did not affect either IFN-gamma production or their survival rate. In addition, immunohistochemistry showed a reduction in tumor-infiltrating lymphocytes containing CD4 and CD8 antigens in the mice treated with phenytoin and zonisamide. Two anticonvulsants, phenytoin and zonisamide, showed a significant inhibitory effect on IFN-gamma production by CLN lymphocytes in murine glioma models, although there was no statistically significant difference in MST between controls and the anticonvulsant-treated mice. These drugs might have some detrimental influence on the prognosis of brain tumor patients when combined with the latent immune dysfunction accompanying the tumor-bearing state.

Animals↗

Colocalization of GP125/CD98 with tropomyosin isoforms at the cell-cell adhesion boundary.

Two monoclonal antibodies designated as 1F6 and 4B10 were obtained on screening for reactivities to CD98-associated molecules by sandwich-type enzyme-linked immunosorbent assaying using hybridoma culture supernatants as the solid phase, cell lysates as an antigen source, and a mixture of biotinylated antibodies to CD98HC as a detector. Flow cytometric analysis with microspheres in combination with 1F6, 4B10, and anti-CD98HC also indicated the association of antibody-defined antigen(s) with CD98. 1F6 and 4B10, stained fibrillate components in fixed and permeated cells but were not reactive with unfixed live cells, suggesting that epitopes reside in the cytoskeleton-associated structure in the intracellular region. Two-color immunostaining followed by confocal microscopy revealed the colocalization of the antigen with CD98 at the cell-cell adhesion boundary of HeLa cells. 1F6 detected proteins with relative molecular masses of 33,000 to 43,000 on immunoblotting analysis involving cell lysates of human and rat cell lines. Analysis with a purified tropomyosin specimen from rabbit skeletal muscle demonstrated that 1F6 and 4B10 recognize tropomyosin. Two-dimensional gel electrophoresis followed by immunoblotting analysis revealed that 1F6 recognizes various tropomyosin isoforms. These results indicated that CD98 physically associates directly or indirectly with tropomyosin, and that this association is closely related to the cell-cell interaction.

Actins↗

Comparative evaluation of Tc-99m MIBI and Tl-201 chloride SPECT in non-small-cell lung cancer mediastinal lymph node metastases.

PURPOSE: To compare the utility of Tc-99m MIBI SPECT and Tl-201 chloride SPECT for presurgical assessment of lung cancer mediastinal lymph node metastases. METHODS: Forty-one patients with non-small-cell lung cancer underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI and were evaluated for mediastinal lymph node involvement. RESULTS: The sensitivity rates of early and delayed Tc-99m MIBI SPECT and of early and delayed Tl-201 chloride SPECT for detecting mediastinal nodal metastases were 69%, 69%, 92%, and 92%, respectively. The corresponding specificity rates were 96%, 96%, 93%, and 96%. CONCLUSION: Tl-201 chloride SPECT is superior to Tc-99m MIBI SPECT when used to detect mediastinal lymph node metastases in patients with non-small-cell lung cancer.

Adult↗

Diagnostic value of TI-201 and three-phase bone scintigraphy for bone and soft-tissue tumors.

PURPOSE: Although TI-201 is highly sensitive for detecting bone and soft-tissue tumors, its uptake is not specific for malignant lesions. This study assessed the differentiation of malignant and benign lesions and evaluated the sensitivity, specificity, and accuracy of TI-201 imaging and three-phase bone scans. MATERIALS AND METHODS: Forty bone and soft-tissue tumors (16 malignant and 24 benign) were evaluated. TI-201 static images were acquired 10 minutes (early) and 2 hours (delayed) after injection of the radionuclide. Within 14 days, three-phase bone scintigraphy was performed using Tc-99m HMDP with the patient in the same position. The count ratio of the lesion compared with the normal contralateral or adjacent site (L:N ratio) was measured. RESULTS: With TI-201 scintigraphy, mean (+/- SD) values of early and delayed L:N ratios were 3.36 +/- 1.25 and 2.88 +/- 1.20, respectively, in malignant lesions; and 1.88 +/- 1.14 and 1.48 +/- 0.76, respectively, in benign lesions. TI-201 accumulation in benign lesions was significantly less than that of malignancies on early and delayed images. However, an overlap of both ratios between malignant and benign lesions was seen. No such significance was detected on three-phase bone scintigraphy (L:N ratios of malignant and benign tumors were 2.57 +/- 1.22 and 2.24 +/- 2.11, respectively, for blood flow imaging; 2.41 +/- 0.78 and 2.26 +/- 1.54, respectively, for blood pool imaging; and 2.80 +/- 2.10 and 2.89 +/- 4.55, respectively, for bone imaging). When we assumed that the tumor was malignant when the delayed TI-201 L:N ratio exceeded the blood pool phase L:N ratio with bone scintigraphy, the sensitivity rate was 81%, specificity rate was 100%, and accuracy rate was 93%. CONCLUSIONS: TI-201 imaging for bone and soft-tissue tumors was better than three-phase bone scintigraphy alone but was not good enough to clearly differentiate malignant lesions from benign ones. TI-201 scintigraphy, performed in combination with three-phase bone scintigraphy, may be superior to either one of the two imaging procedures alone for bone and soft-tissue tumor diagnosis.

Adolescent↗

Comparative study of Tc-99m MIBI and TI-201 SPECT in predicting chemotherapeutic response in non-small-cell lung cancer.

PURPOSE: Tc-99m MIBI can be excluded from cytosol against its concentration gradient as a suitable transport substrate by P-glycoprotein. Tc-99m MIBI has also been shown to be more effective than TI-201 chloride for evaluating the response to chemotherapy in patients with small-cell lung cancer. The relation between Tc-99m MIBI accumulation by the tumor and its response to chemotherapy were evaluated in patients with non-small-cell lung cancer (NSCLC) and compared with the same parameters achieved using TI-201 chloride. METHODS: Thirty-eight patients with NSCLC were examined before chemotherapy was begun. They were classified according to the results of a follow-up computed tomogram into two groups: responders were patients in whom there was a > or =50% decrease and nonresponders were patients in whom there was a <50% decrease in the sum of the product of the maximum perpendicular diameters of all measurable lesions. All patients underwent dual-isotope imaging with TI-201 chloride and Tc-99m MIBI just before chemotherapy. Regions of interest were placed over the tumor uptake (T) and contralateral normal lung tissue (N) areas on one coronal view with a clearly defined lesion, and the T:N ratio and retention index were calculated. RESULTS: The delayed T:N ratio and retention index for Tc-99m MIBI in the responder group were significantly greater (P<0.05) than those in the nonresponder group. There was no significant correlation between the T:N ratio and retention index and tumor response using TI-201 chloride. CONCLUSION: Tc-99m MIBI SPECT may be more effective than TI-201 chloride SPECT for evaluating the response to chemotherapy in patients with NSCLC.

Adult↗

Effect of olprinone, phosphodiesterase III inhibitor, on cerebral blood flow assessed with technetium-99m-ECD SPECT.

Few clinical reports exist regarding the effects of phosphodiesterase III inhibitors on cerebral arteries. Therefore we used a [99mTc]-ECD brain SPECT and an ultrasound method to quantitatively evaluate cerebral and systemic flow dynamics after the administration of olprinone, a phosphodiesterase III inhibitor. In 15 patients (65 +/- 8 years, M/F = 13/2) with no abnormalities on a brain computed tomography (CT), cerebral blood flow and cardiac output were measured using [99mTc]-ECD brain SPECT and Doppler echocardiography, respectively. Measurements were repeated at baseline and after the administration of olprinone. Significant increases in cerebral blood flow (p = 0.0007) and cardiac output (p = 0.001) were observed, and systolic blood pressure (p = 0.02) and systemic vascular resistance (p = 0.002) significantly decreased. No significant correlation between the increase in cerebral blood flow and the increase in cardiac output was observed. The data indicate that olprinone has a direct vasodilator effect on the cerebral artery, which was little related to the increase in cardiac output in patients who had not experienced stroke.

Aged↗

Comparison of 99Tcm-tetrofosmin with 201Tl and 131I in the detection of differentiated thyroid cancer metastases.

The purpose of this study was to assess the detectability of metastatic lesions by 99Tcm-tetrofosmin in differentiated thyroid cancer, and to compare the results with those obtained using 201Tl-chloride and tracer doses of 131I. Twenty-four thyroidectomized patients with metastases were studied. There were 34 metastases, including 16 lung, nine lymph node and nine bone. Radiological studies (chest X-ray, computed tomography and magnetic resonance imaging), serum thyroglobulin assays and histopathological examinations were performed to verify the presence of metastases with positive uptake of the three radionuclides. Increased accumulation of 99Tcm-tetrofosmin was observed in 11 of 16 (68.8%) lung metastases, eight of nine (88.9%) lymph node metastases and eight of nine (88.9%) bone metastases. Increased accumulation of 201Tl and 131I was observed in 11 of 16 (both) (68.8%) lung metastases, eight (88.9%) and three (33.3%), respectively, of lymph node metastases and eight (88.9%) and nine (100%), respectively, of bone metastases. The detectability of thyroid cancer metastases using 99Tcm-tetrofosmin, 201Tl and 131I was 79.4%, 79.4% and 67.6%, respectively. The combined detectabilities of 99Tcm-tetrofosmin and 131I and of 201Tl and 131I were both 88.2%. 99Tcm-tetrofosmin and 201Tl imaging were found to be more sensitive than 131I for the detection of differentiated thyroid cancer metastases, particularly for regional lymph node. The combination of 99Tcm-tetrofosmin and 131I imaging may be a more sensitive and effective method for detecting metastases in differentiated thyroid cancer.

Adenocarcinoma, Follicular↗

Visualization of the motor activation area using SPECT in neurosurgical patients with lesions near the central sulcus.

UNLABELLED: The purpose of this study was to visualize the motor area related to finger movement and a fist-making task using SPECT in patients with lesions near the central sulcus. METHODS: Eleven patients (9 with a brain tumor, 1 with cerebral infarction, and 1 with an arteriovenous malformation) were investigated. The first intravenous injection of 99mTc-ethyl cysteinate dimer (ECD) for the motor activation SPECT images was administered 2 min after completion of the fist-making task with the hand contralateral to the brain lesion. The movement was stopped 2 min after injection, and activation SPECT was performed. After the scan, the second dose of 99mTc-ECD was injected into resting patients, and a second set of SPECT images was acquired. The first set of images was subtracted from the second set to obtain control images. Regions of interest were set bilaterally on the sensorimotor hand area; the supplementary motor area; the frontal, temporal, and occipital lobes; and the cerebellar hemispheres. The results of activation SPECT were expressed as positive or negative for a high-count area, and the regional percentage change for activation images relative to resting images was calculated. RESULTS: Visual assessment of activation images was positive in 9 patients for the sensorimotor hand area and 7 patients for the supplementary motor area. The regional percentage change between activation and resting images for the high-count areas was 19.7% for the sensorimotor hand area and 18.2% for the supplementary motor area. Both values were significantly higher than those for other areas (P<0.05). CONCLUSION: Motor activation SPECT using a 99mTc-ECD split-dose method is easy to perform and may be helpful for presurgical visualization and identification of the sensorimotor hand area or the supplementary motor area.

Brain Mapping↗

[Evaluation of lung lobar ventilation dynamics with magnetic resonance imaging: a comparison of interstitial pneumonia patients with normal subjects].

Magnetic resonance imaging (MRI) was utilized to study lung lobar dynamic ventilation in 11 patients with interstitial pneumonia (IP) and 10 non-smoking men. The IP patients included 7 with interstitial lung disease associated with collagen vascular disease, 3 with idiopathic interstitial pneumonia, and 1 with lung cancer who was excluded from statistical analysis. We calculated lung lobar volumes in each phase from each dynamic image and constructed time-volume curves(TVCs). Lung lobar volume rates(%), fluctuation rates(%), lobar fluctuation rate/total lung fluctuation rate (%), and time lag (sec.) for the IP patients and normal subjects were calculated and compared. In the former, the mean volume rate for the right upper lobe was larger (p < 0.01) than that in normal subjects. The mean volume rate for the left lower lobe in the IP patients was smaller(p < 0.01) than that in the normal subjects. In IP patients, peak TVC for the right middle lobe appeared later (p < 0.01) than that in normal subjects. Although the fluctuation rates and fluctuation rate/total lung fluctuation rate for the lower lobes tended to be higher than those for the upper and middle lobes in normal subjects, this tendency was not distinct in IP patients. The quantitative evaluation of pulmonary ventilation dynamics with MRI may be a useful noninvasive technique for the assessment of lung lobar ventilation in patients with IP.

Adult↗

[Outcomes of home anti-cancer chemotherapy--estimation of hepatic arterial infusion chemotherapy for patients with multiple liver metastases].

A total of 18 patients (13: colon cancer, 5: gastric cancer) with multiple liver metastases (H3) underwent hepatic arterial infusion chemotherapy (HAI) using an implanted arterial port with portable syringe pumps in our outpatient clinic. Clinical perspective: overall response rate was 22.2% (CR: 1 case, PR: 3 cases (1 case: hepatectomy after HAI), NC: 12 cases, PD: 2 cases), however, 7 of 12 cases of NC were long NC (more than 6 months). No major complications with HAI were experienced. Patient Perspective: After HAI in our outpatient clinic, the 50% survival was 341 days, 50% hospital free days were 319 days and home stay rate was 92.9%. Societal Perspective: cost and hospital stay days were significantly reduced. Home anti-cancer chemotherapy using HAI for gastrointestinal cancer patients with multiple liver metastases was safe and efficient from the viewpoint of medical outcomes.

Aged↗

[Results of radioiodine therapy in patients with pulmonary metastases of differentiated thyroid cancer].

Factors affecting the effect of 131I treatment and survival after pulmonary metastases in patients with differentiated thyroid cancer, were studied. Between 1984-1999, pulmonary metastases was observed in 51 out of 153 patients with differentiated thyroid cancer at our institution. Of these 41 patients had papillary and 10 follicular thyroid cancer. There were 37 females and 14 males with mean age (+/- S.D.) of 50.5 +/- 19.0 years. These 51 patients were subjected to 131I therapy. The effect of 131I treatment and the prognostic values of the following variables were examined: sex, age at the time of 131I treatment, histologic type of cancer, size of pulmonary metastases on CT, total-body scintigraphy with 201Tl and 131I, serum thyroglobulin levels and presence of metastases in distant sites other than lung. The effect of 131I treatment was evaluated by means of changes in the number and size of metastatic shadows on chest CT and by serum thyroglobulin levels. The minimum duration of follow-up was 12 months. Therapeutic 131I dose scans revealed detectable uptake in 25 of 51 patients. Therapeutic 131I dose uptake was achieved more frequently in patients under 40 years of age and in those with follicular cancers. Of the 51 patients, 13 were evaluated to be treated successfully. Those under 40 years of age, with 131I uptake in the lung and presence of other metastases showed a good response to treatment than others. Follicular cancer showed a more significant association with coarse type of lung metastases (> 5 mm in diameter on chest CT) and good 131I uptake than papillary cancer. Of all the variables studied, the best prognosis for survival was demonstrated by increased 131I uptake in pulmonary metastases. These results indicate that age, 131I uptake and presence of other metastases are important factors in predicting the effect of 131I treatment for pulmonary metastases of differentiated thyroid cancer.

Adenocarcinoma, Follicular↗