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Biomedical subjects

H Oyamada

Publications and source records attributed to H Oyamada.

At least 109 records · Page 6Linked to original sources

Studies on isolated smooth muscle cells. IX. Application of papain for isolation of single smooth muscle cells from guinea-pig taenia coli.

To prepare single smooth muscle cells from the taenia coli of guinea pig, the application of papain to the enzymatic solution was examined under two conditions: 1) the isolation in a modified Tyrode solution (containing 0.18 mM Ca2+: 0.18 mM Ca2+-Tyrode solution) and 2) the isolation in a high-K+ Tyrode solution (Na+ was replaced by K+, and Ca2+ was not added: high-K+ Tyrode solution). The presence of papain during collagenase digestion reduced contamination of broken cells and cell debris. In the case of the high-K+ Tyrode solution, papain increased the yield of single cells significantly. The cells were contracted in a dose-dependent manner by Ca2+ in the high-K+ Tyrode solution and by carbachol in 0.18 mM Ca2+-Tyrode solution; furthermore, the contractions were antagonized by verapamil and atropine, respectively. Treatment with papain did not affect cell sensitivity to the stimulants. Therefore, our results suggest that the addition of papain is useful for the isolation of single cells to investigate the physiological and pharmacological characteristics of smooth muscle.

Animals↗

[Results obtained from the group study on the clinical efficacy of SPECT of the liver].

The influence of SPECT over the detectability of SOL in the liver was evaluated by the Subcommittee on Efficacy Study, which belongs to Medical and Pharmaceutical Committee of Japan Radioisotope Association, under the participation of 9 hospitals including some university hospitals. In this study segmental reading of the SOL was requested. The film reading was performed twice on the different patient-groups and the results from well-experienced doctors (11 doctors) were summarized, indicating a slight increase in sensitivity as a whole although there were some doctors showing a reverse effect in each performance. Sensitivity was determined in the patient-group without SOL, which showed a slight decrease as a whole, indicating that SPECT had some possibility of increasing false positive cases. In the study of SOL detectability based on its segmental location, a marked positive effect of SPECT was noted in the right anterior and right posterior segments whereas a marked negative effect in the left lateral segment. The left medial segment also showed a slight decrease in the detectability of SOL.

Evaluation Studies as Topic↗

[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↗

[Recent status of the diagnosis and treatment of bone metastasis in patients with advanced lung cancer].

The incidence and prognosis of patients with bone metastasis in primary advanced lung cancer were studied retrospectively. Between Jan. 1980 and Dec. 1985, 289 cases entered various kinds of chemotherapy protocol studies. Patients with bone metastasis of non-small cell lung cancer (NSC) comprised 44% (86/192), and those with small cell lung cancer (SC) comprised 43% (42/97). Histologically, 48% of adenocarcinoma, 50% of large cell carcinoma and 31% of squamous cell carcinoma showed bone metastasis. 8 percent of NSC bone meta (+) cases had an initial symptom of bone metastasis. Bone scan and bone X-ray were complementary and useful for diagnosis of bone metastasis, and sequential examinations tended to reduce the incidence of false-positive cases. Vertebral column, rib, pelvis and femur were the most common sites. Over 70% of the bone metastasis were in multiple skeletal systems, and 90% showed multiple-site involvement for both NSC and SC. Radiation therapy effectively reduced severe pain but paralysis was hard to control. In very few cases surgical treatment was indicated because of multiple bone metastasis, and systemic dissemination. Bone scan in 12% of SC patients showed apparent improvement with systemic chemotherapy. Among the M1 group of adenocarcinoma, median survival was 9 months in bone (+) cases, 11 months in bone (-) cases, 2 year survival was 8%, and 24%, and 3-year survival 2% and 22%, respectively. Among the bone(+) group and bone(-) group in ED cases of SC, median survival was 10 months vs. 11 months, and 2-year survival rates were both 13%. 22 percent (8/36) of squamous cell carcinomas without bone metastasis showed hypercalcemia (5.5 mEq/l). In patients with advanced lung cancer the major goal of treatment is recovery of the performance status of the patient and the relief of pain. In the case of SC, intensive systemic chemotherapy should be conducted as an adjuvant to local therapy.

Adenocarcinoma↗

[Diagnosis and treatment of metastatic bone cancer of the extremities].

Eight hundred and thirty-six patients with metastatic cancer in the bone excluding autopsy findings, occurring between January, 1976 and December, 1985 were reviewed. The most frequent site of primary focus was the breast (33.2%), followed by lung (24.6%). Three hundred and forty-two patients (40.9%) were male and 494 (59.1%) female. Diagnosis of bone metastasis was based on abnormal accumulation in the bone scintigram and abnormal findings in the bone X-ray at the same site. Out of 836 patients, 285 had metastatic skeletal lesion including extremities and 43 had a solitary lesion of the extremity. The most frequent site of bone metastases in the extremity was proximal femur and involvement of the femur was 65.2% and that of humerus was 25.6%. The majority of the patients were treated by irradiation (24.9%), irradiation with chemotherapy and/or hormone therapy (21.1%), chemotherapy (18.6%) and chemotherapy with hormone therapy (17.2%), on the other hand, only 25(8.8%) of 285 patients were treated by surgical procedures. Cumulative survival rate after diagnosis of bone metastasis varied with site of primary focus and 5 year survival rate of all cases was 6.1%. Clinical courses after skeletal metastasis were separated into two types, and one type was breast type which was slow and other type was lung type which was rapid. The most important factor for the prognosis of the patients with bone metastasis is thought to be the primary site of origin.

Adult↗

Experimental study on the collimator for increasing the resolution of N-isopropyl-p-(123I)iodoamphetamine (IMP) SPECT imaging of the brain.

This study was carried out to design a new collimator for the present 123I-IMP SPECT imaging of the brain, which is hindered by the contamination of 124I and 126I. In this study we intended to increase spacial resolution along the transaxial direction and, at the same time, to compensate for the decrease of sensitivity by sacrificing the resolution along the axial direction to some extent. For this purpose, we developed 4 kinds of slat type units; ultrahigh resolution (UHR), high resolution (HR), high sensitivity (HS), and ultrahigh sensitivity (UHS). In practice, either UHR or HR is set to the detector together with either HS or UHS. After testing 4 kinds of combinations, we found that the combination of UHR-HS gave us far better images than those obtained with the conventional medium energy parallel hole collimator and was best suited for 123I-IMP SPECT imaging of the brain at present. We are now thinking of fusing these two units together into one collimator.

Amphetamines↗

Relative frequency of human rotavirus subgroups 1 and 2 in Japanese children with acute gastroenteritis.

Recently developed monoclonal antibodies against the 42,000-dalton major inner capsid protein were used in an enzyme immunoassay to subgroup a total of 156 rotavirus specimens obtained from Japanese infants and young children with acute gastroenteritis during the period between December 1981 and April 1983. Only 2 specimens (1.3%) were identified as subgroup 1, whereas 154 specimens (98.7%) were identified as subgroup 2. The percentage of subgroup 2 rotaviruses obtained in this study was the highest among similar studies thus far performed in different areas of the world. One of the subgroup 1 isolates had fast-moving 10th and 11th gene segments (the "long" pattern) typical of the subgroup 2 human rotaviruses.

Antibodies, Monoclonal↗

Segmental assessment on ordinary scintigrams and SPECT images of the liver.

By examining the area of defect elucidated on the scintigrams and SPECT (single photon emission computed tomography) images, the extension of the tumor into segments was assessed in cases where the SOL (space-occupying lesion) was determined by other methods. In this study, we followed the Couinaud 's segmentation. As a result, it was found that the segment with a SOL could be diagnosed fairly well on radionuclide images. Some incorrect assumptions were also found about the segments on ordinary scintigrams in previously published articles. These incorrect assumptions have been accepted for a long time. Although we do not deny that TCT (transmission X-ray computed tomography), echography, angiography, etc. are necessary for a precise judgment on liver segment and also that there are some cases in which the segmental assessment of these radionuclide images is impossible, we do believe that this kind of effort will improve the diagnostic capability of the radionuclide images.

Adult↗

Serological survey of hepatitis B virus (HBV) markers in out- and in-patients in a university hospital.

Of a total of 13,596 patients and 1,876 blood donors in a university hospital examined, 550 (4.1%) patients and 31 (1.7%) donors possessed hepatitis B surface antigen (HBsAg) in their blood. The higher incidence of HBsAg in the patient population than in the blood donors verified the view that medical personnel and hospitalized patients are at increased risk of acquiring HBV infection. To assess the actual hazard of the HBsAg-positive patients, we examined hepatitis Be antigen (HBeAg) and its antibody (anti-HBe) status of 228 HBsAg-positive patients and found that 39 (18%) were positive for HBeAg and 168 (74.5%) were positive for anti-HBe. This indicated that only one fifth of the HBsAg-positive patients should be drawn attention in terms of HBV transmission within a hospital.

Hepatitis B Antigens↗

Clinical evaluation of single photon emission computed tomography of the brain.

Single photon emission computed tomography (ECT) was performed on 67 patients. ECT images were taken with a Shimadzu scintillation camera, LFOV-E, before a delayed scan. Eighteen of 67 patients showed abnormal findings on the ECT images. Fourteen of the 18 had a transmission X-ray CT (TCT) study as well. There were eleven cases with brain metastasis, and a surgical wound. Eleven of forty-nine ECT-negative patients had a TCT study as well, and intracranial lesions were found in five. The smallest lesion found by ECT was 0.5 cm in diameter on the TCT image and the largest lesion missed by ECT was a tumor in the corpus callosum, measuring 4.2 X 2.7 cm. As far as the patients who also received TCT study are concerned, both the ECT and the ordinary scan were thought to be equal in sixteen patients and ECT to be superior in seven whereas the ordinary scintigram was superior in two. At present, ECT is considered to be useful when it is used in addition to the ordinary scans. In the field of clinical nuclear medicine, the development of new radiopharmaceuticals which are labeled with single photon emitters and which can show the metabolic activity of the brain is eagerly awaited.

Adult↗

An evaluation of the mediastinal lymphoscintigram for carcinoma of the esophagus studied with 99mTc rhenium sulfur colloid.

Lymphoscintigraphies of esophageal carcinoma in nine patients were studied with the aid of 99mTc-labeled rhenium sulfur colloid (99mTc-Re). 99mTc-Re was injected into the submucosal layer of the esophagus (just above the oral side of the tumor) using an esophagoscope, 1 or 2 days before operation. Lymphoscintigraphies at intervals of 1, 3 and 20 h after the injection were performed. After that, the region and the number of the visualized (hot) nodes were assessed. After the operation the lymph nodes were dissected and the hot nodes were determined by scintiphotography. The dissected nodes were then studied histologically. A total of 106 nodes were removed from the mediastinum of nine patients. Histologically, metastases were found in 12 of 106 nodes. Twenty six of 106 (24.5%) could be observed visually on the scintigram and 80 (75.5%) could not. Among the visualized (hot) nodes, 34.6% were positive for metastasis. On the other hand, among the nonvisualized, so-called cold, nodes, only 3.8% were positive for metastasis. Hot nodes of the esophagus indicate a high percentage probability of metastatic nodes.

Aged↗