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Biomedical subjects

H Oyamada

Publications and source records attributed to H Oyamada.

At least 91 records · Page 5Linked to original sources
PubMed1989

Clinical significance of 99mTc-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) in the diagnosis of intrahepatic masses.

Hepatobiliary scintigraphy with 99mTc-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) was carried out on 48 patients with intrahepatic masses, 44 with hepatocellular carcinoma and one each of hepatocellular adenoma, focal nodular hyperplasia, cholangiocellular carcinoma, and adenoid cystic carcinoma. Scans were performed twice, early scan (30 min post i.v.) and delayed scan (2.5 h post i.v.), and the delayed scan was used for assessing the accumulation of 99mTc-PMT in the intrahepatic masses. In the hepatocellular carcinoma group, based on individual patients, 17 out of 44 (38.6%) showed accumulation of 99mTc-PMT in various degrees; and based on individual masses, accumulation was noted in 21 out of 55 masses (38.2%). However, only the cases which had not received transarterial infusion of anti-cancer drugs (TAI) and/or blocking agents (TAE) were taken into consideration, 9 out of 18 patients (50%) and 12 out of 25 masses (48.0%) were found capable of picking up 99mTc-PMT. A case of hepatocellular adenoma showed a strong accumulation of 99mTc-PMT in the mass which was depicted as a defect on the 99mTc-colloid scan and did not show a significant accumulation of 67Ga. In a case of focal nodular hyperplasia, there were two space-occupying lesions (SOLs), one of which showed a clear-cut defect on the 99mTc-colloid scan and the other which showed only a distorted uptake pattern. However, both masses were strongly positive with 99mTc-PMT. 99mTc-PMT scintigraphy is useful in connection with 99mTc-colloid scan and sometimes with 67Ga-citrate in the diagnosis of intrahepatic masses originating from hepatocytes.

Adenoma, Bile Duct↗
PubMed1989

[Chemoembolization with degradable starch microspheres for liver metastases in colorectal cancer].

Transcatheter chemoembolization using Degradable Starch Microspheres (DSM) was performed in 17 patients with liver metastases of colorectal cancer. Mitomycin C mixed with DSM was injected into the proper hepatic artery. Tumor regression of over 50% was observed in 9 of 17 cases (53%). Elevated serum CEA levels (greater than 10 ng/ml) decreased in 10 of 15 cases (67%). One-year survival rate was 50% in 17 cases. One-year survival rate was 100% in 7 cases with several liver metastases (H2). Abdominal pain occurred in 36%, mostly disappearing within 2 hours. No major side effects such as bone marrow suppression or hepatotoxicity were observed. Our results suggest that chemoembolization using DSM is effective and safe in the treatment of liver metastases from colorectal cancer.

Colorectal Neoplasms↗
PubMed1989

[Chemo-embolization using degradable starch microspheres and regional hyperthermia in unresectable hepatocellular carcinoma].

Antitumor effects and prognosis of the patients with unresectable hepatocellular carcinoma were investigated in the treatment of chemo-embolization using degradable starch microspheres (DSM) and regional hyperthermia. Twenty-six cases were treated with chemo-embolization using DSM alone (Group A) and eighteen cases were treated with combination of chemo-embolization and hyperthermia (Group B). Tumor regression rates over 50% were 42% (11/26) and 56% (10/18) in Group A and Group B, respectively. In the patients with tumors over 7 cm in diameter, no favorable response was obtained in Group A (0/11), but the response rate was increased to 56% (5/9) by the combination of hyperthermia. In the patients with arterio-portal shunt, therapeutic effects were observed in 17% (1/6) and 50% (1/2) of Group A and Group B, respectively. In the patients with portal invasion (Vp2 and Vp3), no favorable response was demonstrated in Group A (0/4), but tumor response was demonstrated in one out of 3 cases in Group B. One- and two-year survival rates were 59% and 53%, respectively, in Group A, and 93% and 45%, respectively, in Group B. The DSM, temporary embolus, is suitable for the combination of hyperthermia because chemo-embolization using DSM can be performed many times. Therefore, these results suggested that chemo-embolization using DSM should be beneficial as combination therapy for unresectable hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1989

[Influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes].

The influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes (PMN) were studied by an electron spin resonance assay using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapper. The intensity of DMPO-OOH signal generated from the hypoxanthine-xanthine oxidase system was not influenced by the presence of azelastine, ketotifen, disodium cromoglycate, mequitazine, or methylprednisolone, but it decreased in the presence of AA-673. A kinetic study showed that the second order rate constant for reaction between AA-673 and superoxide anion at pH 7.4 was 2.9 x 10(8)M-1S-1. The relative intensity of DMPO-OOH spin adduct generated from PMN stimulated with phorbol myristate acetate (PMA) or opsonized zymosan (OZ) significantly decreased in the presence of azelastine: from the PMN-PMA system, with 10.7 microM concentration of molar concentration causing 50% reduction of the signal intensity (IC50), while from the PMN-OZ system, with 10.5 microM concentration of IC50, and also decreased in the presence of mequitazine: from the PMN-PMA system, with 10.8 microM concentration of IC50, while from the PMN-OZ system, less than 2.0 microM concentration of IC50. These results suggest that some anti-allergic drugs may have anti-inflammatory and anti-oxidative actions due to scavenging superoxide radicals or due to inhibiting superoxide production.

Aminopyridines↗
PubMed1989

[Radioimmunoimaging of malignant melanoma with In-111-labeled monoclonal antibodies 96.5 and ZME 018].

This paper includes the results of imaging and kinetic studies on two kinds of In-111-labeled monoclonal antibodies (MoAbs), 96.5 and ZME 018, which are known to have capability of recognizing different surface antigens present in malignant melanoma cells. These MoAbs were supplied by Hybritech Inc. through Teijin Ltd. The former MoAb (96.5) was used on 11 cases of malignant melanoma and one case of basal cell carcinoma, and the latter MoAb (ZME 018) was used on 6 cases of malignant melanoma and one case of basal cell carcinoma. As for the malignant melanoma, the results obtained from both patients groups were compared to each other. Twenty-four out of 31 lesions in the former group and 9 (including 2 occult lesions) out of 10 lesions in the latter group were visualized. However, these positive ratios can not be compared to each other because of the very small number of the lesions in the latter group. One basal cell carcinoma each from both groups were faintly visualized. Distribution patterns of these In-111-labeled MoAbs were similar to each other. Except for the first two cases in the former group, labeling efficiencies were 94.3 +/- 0.7% with 96.5 and 92.0 +/- 0.6% with ZME 018. Urinary excretions on the 1st day were 8.3 +/- 0.9% with the former and 9.3 +/- 0.3% with the latter. However, there was no statistical difference. Following the 1st day, these values changed at the level of several per cent from the 2nd to 4th day, showing a subtle and gradual rise and slightly lower values for In-111-ZME 018. But, again, there were no statistical differences. Whole body retention curves in both groups were similar to each other, and blood clearance curves were also found similar in both groups. HAMA titers were checked in all patients and were found elevated after the administration in most of the cases. Although the number of patients tested in this series is small, especially with In-111-ZME 018, both MoAbs labeled with In-111 seem to be equally capable of visualizing malignant melanoma. Possibility of the treatment of malignant melanoma with this kind of technique was also discussed.

Adult↗
PubMed1989

[Radioimmunoimaging of malignant melanoma with In-111 labeled monoclonal antibody 96.5 and ZME-0.18].

In-111 labeled mouse antimelanoma monoclonal antibody (MoAb) type 96.5 and ZME-018 were examined in patients with malignant melanoma. These antibodies were supplied by Hybriteck Inc. MoAb was conjugated with DTPA first and then labeled with In-111. Radioimmunolocalization of an In-111-MoAb, type 96.5, was investigated in 23 patients with metastatic malignant melanoma. One of the 23 patients examined twice was found to be without any side effects. Seventeen out of these patients were examined with Ga-67 scintigraphy to evaluate clinical usefulness of radioimmunoimaging. Of a total of 58 metastases which had been diagnosed previously by conventional techniques, 45 were visualized by In-111-96.5 scans for an overall true positive image rate of 77.6%. But the imaging rate by Ga-67 scan was 67.4%. From examining for MoAb, ZME-018, in 15 patients, of a total of 43 metastases, 28 were detected by In-111-ZME-018 scan, with an imaging rate of 65.1%. But the imaging rate in Ga-67 scan was 43.2%. Clinical usefulness was recognized to be effective in radioimmunoimaging with MoAb, 111In-111-96.5 and In-111-ZME-018, for the diagnosis of malignant melanoma.

Antibodies, Monoclonal↗
PubMed1988

Esophageal candidiasis.

Among 3,501 individuals receiving endoscopic examination for the upper digestive tract, 41 were found to have esophageal candidiasis including 17 malignancies, 14 immunological disorders, 4 diabetes mellitus, 7 other underlying diseases and 7 apparently healthy subjects. The diagnosis was made either by brushing of the esophagus or by histological examination of the biopsied specimen. Systemic invasion of fungi was observed mainly in patients with malignancy involving the hematopoietic system, and most of them had been treated by corticosteroids, antibiotics or anticancer agents. Although complications associated with esophageal candidiasis are rare, it is emphasized that those patients with malignancy as well as impared immunity should be carefully examined for esophageal candidiasis, in order to prevent the fungi from developing invasive candidiasis. It should be noted that a few cases of gastric ulcer treated by H2 blocker revealed esophageal candidiasis, suggesting that decrease of gastric acidity might be one of the factors involved in this pathological condition.

Amphotericin B↗
PubMed1988

[Chemoembolization and regional hyperthermia with degradable starch microspheres in the treatment of malignant hepatic tumors].

Antitumor effects of chemoembolization with degradable starch microspheres (DSM) combined with regional hyperthermia (HT) were investigated in patients with hepatocellular carcinoma and metastatic liver cancer. Chemoembolization with DSM was performed in 39 cases of hepatocellular carcinoma (HCC) and in 25 cases of metastatic liver cancer. Thirteen cases of HCC and 3 cases of metastatic liver cancer were treated with the combination of HT. A catheter was placed in the proper hepatic artery via the trans-femoral approach. Adriamycin or Mitomycin C mixed with DSM was injected every 2 or 3 weeks through the catheter. Thermotron RF-8, the heating device used in this study, is operated at 8 MHz radiofrequency. Hyperthermia treatment was applied twice a week. The therapeutic effect of this treatment was evaluated by the change in tumor size measured by angiography or computed tomography. Tumor regression over 50% was observed in 42% of the patients with HCC treated with chemoembolization alone and in 54% of those with chemoembolization and HT. In the patients with metastatic liver cancer, tumor regression over 50% was observed in 65% of the patients treated with chemoembolization alone and in 33% of those with chemoembolization and HT. One-year survival rate after the initial treatment in patients with HCC was 66% and 89% in the patients treated with chemoembolization alone and with chemoembolization and HT, respectively. One and two-year survival rates in the patients with metastatic liver cancer was 55% and 41% in the treatment with chemoembolization alone. These results suggest that chemoembolization using DSM was markedly effective in the patients with malignant hepatic tumors, particularly in metastatic liver cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Analysis of discontinuity in visual contours in area 19 of the cat.

Previous ablation studies have suggested that area 19 of the cat plays an important role in pattern discrimination. To clarify the functional roles unique to area 19, we studied the receptive-field properties of cells in area 19 and compared them with those of cells in area 17. Recordings were made of anesthetized and immobilized animals. The majority (72%) of the cells in area 17 responded maximally to an elongated bar at a particular orientation, while they responded only weakly or not at all to a small spot (elongation-requiring cells). In contrast, more than half (63%) of the cells in area 19 showed a good response to a nonoriented small stimulus moving in any direction (dot-responsive cells). Two-thirds of the dot-responsive cells in area 19 failed to respond when the moving slit was elongated to more than some length in any orientation. These dot-responsive cells of the "inhibited-by-length" type responded strongly to the end of a long bar, and many of them also responded strongly to a break point in the middle of a long bar. We suggest that these dot-responsive cells of the "inhibited-by-length" type detect discontinuities in contours. Though they are in the minority, elongation-requiring cells constitute a considerable population (37%) in area 19, and dot-responsive and elongation-requiring cells from columnar patches in the same area. We conclude that, in contrast to area 17, whose main role is the decomposition of patterns into oriented contours, area 19 analyzes both orientation and discontinuities, with a strong bias towards the latter.

Animals↗
PubMed1987

Effect of DFP on loading of fura 2/AM and quin 2/AM into single smooth muscle cells prepared from guinea pig taenia coli.

The effect of diisopropyl fluorophosphate (DFP), a potent cholinesterase (ChE) inhibitor, on loading quin 2 acetoxymethyl ester (quin 2/AM) and fura 2/AM into smooth muscle cells isolated from guinea pig taenia coli was investigated spectrofluorometrically. The presence of DFP during the loading permitted the incorporation of quin 2 into the cells, so that it became possible to measure intracellular Ca2+ concentrations using the ester of this dye. Also, DFP significantly enhanced the incorporation of fura 2 into the cells. These results indicate that loading of quin 2/AM and fura 2/AM into the smooth muscle cells may depend on the suppression of ChE or various serine protease activities outside cells.

Aminoquinolines↗
PubMed1987

Preparation of single smooth muscle cells from guinea pig taenia coli by combinations of purified collagenase and papain.

Procedures for isolation of single smooth muscle cells from taenia coli of guinea pigs have been developed. The preparation was performed with a combination of highly purified collagenase prepared by Amano Pharmaceutical Co. (Japan) and papain obtained from Sigma Chemical Co. (Type III). This combination resulted in very high yield of the single cells (39.2 +/- 4.5 X 10(3) cells/mg tissue wet wt) and less cell debris. In the ordinary procedure, commercially available collagenase preparations contaminated with various peptidases have been used. With these enzyme preparations, however, the yield of single cells was dependent on the batch of the preparations, and a large amount of cell debris was contaminated. Combination of the highly purified collagenase and papain resulted in higher yields constantly. Cells, isolated with these enzymes in a medium consisting of 140 mM KCl, 1.0 mM MgCl2, 4.2 mM Hepes, and 5.6 mM glucose (pH 7.4), were spindle shaped. The length of the cells was 185.9 +/- 5.2 micron (n = 90) and the diameter was approximately 12.6 micron. The diameter was not dependent on the cell length. More than 80% of the single cells were viable when examined by trypan blue exclusion technique. Under the depolarized condition, cells remained viable longer because of lower energy consumption, and these cells were contracted by Ca dose dependently. The dose-response relationship was similar to that obtained with intact tissue. Because the cells are constantly available with higher yield, the preparation might be applicable for biochemical research such as ion flux. Details of cell properties under the physiological conditions are under investigation.

Animals↗
PubMed1987

Proposal of segmental reading of radionuclide images of the liver.

The method of segmental reading of radionuclide images of the liver, which include ordinary (planar) scintigrams as well as SPECT (single photon emission computed tomography) images are presented. Patients showing defects on the liver scan, segments of which have been elucidated by other modalities, were chosen for this study, and the location of defects was assessed in connection with the segment in which they were located. On the basis of this study, the author presents his own segmentation of radionuclide images of the liver. This segmentation seems to be very useful in clinical practice and when applied to ordinary scintigrams, appears to be quite different from the previously published segmentation, which is thought to be partially incorrect.

Humans↗