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Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 343 records · Page 19Linked to original sources
PubMed1991

A diaphragmatic compensating filter for hepatic angiography.

To enhance the clarity of angiographic images, a diaphragmatic compensating filter (DCF) covering the sub-phrenic portion was constructed. The required shape of a DCF for a high optical density part of the angiograms was determined by the distribution limit of the outline of the diaphragms, but the shape of the low optical density part could not be specified. The smallest tolerance of a DCF for the respiratory motion of a diaphragm was 13.2 mm at the film. Thus, a DCF was effective in more than 95.8% of angiograms. Our clinical results showed remarkable improvement in those images. The clinical areas between radiographic images with and without a DCF were improved by more than 27% according to an image analysis system. Therefore a DCF is indispensable in conventional hepatic angiography and digital subtraction angiography. In addition, only one type of a DCF is possible for use in combination with lateral compensating filters.

Hepatic Artery↗
PubMed1990

Growth inhibition of glioma cells transfected with the human beta-interferon gene by liposomes coupled with a monoclonal antibody.

A human beta-interferon (HuIFN-beta) gene inserted into a eukaryotic expression vector (pSV2IFN-beta) was entrapped in liposomes having positive charges on their surface. Liposome-mediated transfection of the gene into cultured glioma cells (U251-MG) resulted in the secretion of HuIFN-beta into the medium. The HuIFN-beta level in the culture medium of glioma cells reached 24 +/- 8 (mean +/- SD) IU/ml after 96 h of incubation, at which level the growth inhibitory effect on the cells was found to be greater than 40 times as compared with exogenously added HuIFN-beta. When the plasmid-containing liposomes were coupled with a monoclonal antibody (G-22 MCA) against glioma-associated antigen, the level of HuIFN-beta in the medium was 178 +/- 26 IU/ml, resulting in a 7-fold increase, and the growth inhibitory effect was further elevated. Since the addition of a monoclonal antibody against HuIFN-beta to the medium did not cause the cell growth to resume, the growth inhibitory effect on the cells seems to be ascribed to HuIFN-beta produced in the cells transfected with its gene. Accordingly, the specific delivery of the HuIFN-beta gene into glioma cells by the use of such liposomes might become a useful technique for gene therapy of malignant glioma.

Animals↗
PubMed1990

Translocation of exogenous platelet-activating factor and its lyso-compound through plasma membranes is a rate-limiting step for their metabolic conversions into alkylacylglycerophosphocholines in rabbit platelets and guinea-pig leukocytes.

Platelets and leukocytes are known to degrade platelet-activating factor (PAF), a potential mediator of inflammation, to its lyso-derivative (lyso-PAF) and then convert this to 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholines. However, little is known about the mechanism of internalization of PAF and lyso-PAF, which is a prerequisite for their metabolism within the cells. In this work, the internalization of PAF and lyso-PAF by rabbit platelet and guinea-pig leukocyte plasma-membranes were examined by the washing method with bovine serum albumin. The rates of translocation of PAF and lyso-PAF across guinea-pig plasma membranes were significantly higher than those across rabbit platelets. In these cells, the translocation of PAF was found to be accelerated indirectly by activation of PAF receptors by a small portion of added PAF. Results suggest that a temperature-dependent diffusion process is involved in the internalization of these phospholipids. In both rabbit platelets and guinea-pig leukocytes, the translocation of PAF and lyso-PAF through the plasma membranes was shown to be rate-limiting for the metabolic conversion of these compounds to 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine.

Animals↗
PubMed1990

A case of infantile acute monocytic leukemia caused by vertical transmission of the mother's leukemic cells.

A case of infantile acute monocytic leukemia (AMoL), which was probably transmitted from a pregnant woman with leukemia to her unborn infant, is presented. A woman had AMoL when her third infant was born. This infant, who was a boy, also suffered from AMoL when he was 20 months of age. The infant's leukemic cells had the same cytochemical and immunophenotypic patterns as the mother's leukemic cells. By cytogenetic analysis, the majority of the infant's leukemic marrow cells had the 46,XX karyotype and showed no Y body by quinacrine staining. Moreover, the phenotype for human major histocompatibility system, HLA-A, HLA-B, and HLA-DR of the infant's leukemic cells was consistent with that of the mother's lymphocytes. Thus, the infant's leukemic clone was found to be identical to the mother's leukemic clone. His lymphocytes could not react with the mother's leukemic cells or his own leukemic cells in mixed lymphocyte culture, suggesting that the HLA homozygosity of the mother may have played a role in inducing immunologic tolerance to the immigrated leukemic cells in the infant. This is the first report of an infantile leukemia transmitted from a mother with leukemia, supposedly through the placenta.

Adult↗
PubMed1990

Computed tomographic findings of nasopharyngeal carcinoma with skull base and intracranial involvement.

Twenty-nine patients with nasopharyngeal carcinoma (NPC) with skull base or intracranial involvement were analyzed by high-resolution computed tomography (CT). We divided the path of the primary tumor spread into six directions from the nasopharynx. The most common direction of spread was the anterior region, and the second most common was the posterolateral region. Recently, high resolution CT has been used for the diagnosis of the nasopharynx. T-staging of NPC was made according to the International Union Against Cancer (UICC) TNM classification system, depending on clinical findings and conventional radiograph examinations (not including CT). CT images were valuable for detection of the primary tumor involvement of the skull base region in NPC. Furthermore, bone target CT images were better for searching for subtle bony changes. Therefore, we recommend that CT should be used in T-staging of NPC systematically. When CT is used as one of the staging criteria, some patients with NPC with subtle bony changes will be upstaged.

Adolescent↗
PubMed1990

Prediction of left ventricular function during supine bicycle ergometer exercise in angina-free patients with old myocardial infarction.

We investigated whether or not left ventricular function during dynamic exercise in angina-free patients with old myocardial infarction could be estimated using resting left ventricular function and noninvasive parameters determined during exercise. We studied 70 patients with old myocardial infarction by measuring hemodynamic parameters during supine multistage bicycle ergometer exercise. Coronary arteriography and left ventriculography were performed: then the left ventricular ejection fraction and left ventricular end-diastolic volume were measured. The parametric changes (delta) between rest and peak exercise were determined. Significant positive correlations were observed between cardiac index (CI) at rest and at peak exercise (r = 0.62, p less than 0.001), as well as between pulmonary artery wedge pressure (PAWP) at rest and at peak exercise (r = 0.72, p less than 0.001). Multiple regression analysis indicated that CI and PAWP at peak exercise as dependent variables were best described by the equations: CI at peak exercise = 1.074 [CIrest] +0.031 [delta HR] + 0.004 [ExD] + 0.018 [LVEF] - 1.560 (r = 0.79, p less than 0.001), PAWP at peak exercise = 0.994 [PAWPrest] - 0.181 [LVEF] + 0.203 [delta DBP] -0.076 [delta HR] -21.488 (r = 0.80, p less than 0.001). These data suggested that CI and PAWP during dynamic exercise in angina-free patients with old myocardial infarction could be predicted using noninvasive parameters, such as increments of blood pressure and heart rate as well as exercise duration, together with data on resting left ventricular function, such as resting CI, resting PAWP, and resting left ventricular ejection fraction (LVEF).

Adult↗
PubMed1990

Radioimaging of human glioma xenografts with 123I labeled monoclonal antibody G-22 against glioma-associated antigen.

Monoclonal antibody (MCA) G-22 is directed against a human glioma-associated surface antigen. Its availability for the radioimmunodetection of human glioma was analyzed by utilizing the xenografts in athymic mice. Nude mice with subcutaneous grafts of U251-MG or U251-SP glioma received intravenous administration of 123I or 131I labeled F(ab')2 fragment or whole immunoglobulin. Results of radioimaging revealed that 123I-labeled antibody was better than the 131I-labeled. It was also noted that administration of 123I-labeled F(ab')2 fragment of G-22 MCA enabled the imaging of human glioma xenografts weighing 80-650 mg after 48 hours. When biodistribution of 123I MCA was compared between G-22 and control antibodies, the percentages of dose/g in tumors were 5.228-1.799 at 30 hours and 4.112-1.132 at 48 hours with G-22 and they were 4.164-1.248 and 0.314-0.142 with control. The tumor/blood ratio until 72 hours after injection was constantly above 1 with G-22 and less than 1 with control antibody. These results indicate the potential usefulness of G-22 MCA for the radioimmunodetection of human gliomas.

Animals↗
PubMed1990

Radioimmunoassay of glioma-associated antigen in cerebrospinal fluid and its usefulness for the diagnosis and monitoring of human glioma.

Quantitative determination of human glioma-associated antigen in cerebrospinal fluids (CSFs) obtained from 66 patients with a variety of neurological diseases was performed by solid-phase radioimmunoassay with a monoclonal antibody (G-22). In this system, the minimum detectable amount of the antigen in the CSF was 8 ng/ml. It was demonstrated that CSF diagnosis of glioblastoma might be possible in the case of small tumors with a diameter of less than 2 cm. CSFs obtained from all 18 patients with glioma were positive and the level varied from 11.2 to 186.1 ng/ml. The antigen level in the cystic fluid of the tumor was higher than that in CSF. There was a tendency for the antigen level in CSF to be correlated with the tumor size and the type of histology. The malignant types of glioblastoma or medulloblastoma showed higher levels than the benign type of ependymoma and astrocytoma. Most types of non-gliomatous brain tumor were negative except immature teratoma, meningioma with central neurofibromatosis, and metastatic brain tumor from lung cancer. We also noted that tumor progression or regression of malignant glioma could be predicted by the monitoring of the antigen in the CSF.

Adult↗
PubMed1990

Augmentation of various immune reactivities of tumor-bearing hosts with an extract of Cordyceps sinensis.

In order to enhance general reactivity of immune system in the tumor-bearing host, we employed extract of Cordyceps sinensis (CSE) as a biological response modifier. Cordyceps sinensis is an interesting material produced by a kind of mushroom parasitic to larval moths and was used to hasten recovery from exhaustion in ancient China. In this experiment, C57BL/6 mice implanted subcutaneously with syngeneic EL-4 lymphoma cells were employed as the host. Oral administration of the extract leads to a reduction of tumor size and prolongation of the host survival time. As judged by plaque-forming cells against T-dependent (sheep erythrocytes) and T-independent (bacterial lipopolysaccharide) antigens, CSE showed to augment the antibody responses. As for the activities of peritoneal macrophages, chemotaxis was dramatically depressed within a few days after EL-4 transplantation up to the end of life, but treatment with CSE at -14, -7, -4, +4, +7 and +10 days after the tumor transplantation augmented the activity about four times stronger than that of control. Phagocytic activity of macrophages was also decreased in tumor-bearing mice treated with cyclophosphamide (100 mg/kg) 3 and 5 days after tumor transplantation. But administration of CSE restored the activity to more than the normal level. The overall efficacy of CSE was tested with protective activity against systemic infection by Salmonella enteritides. The tumor-bearing mice receiving this medicine lived significantly longer than any other groups without CSE.

Administration, Oral↗
PubMed1990

A case of gallbladder cancer producing granulocyte-colony-stimulating factor.

A patient with pleomorphic giant cell carcinoma of the gallbladder also had mild neutrophilia, and this tumor was found to be human granulocyte colony-stimulating factor (G-CSF)-positive on immunohistochemical staining. CSF activity in urine and serum was not examined, but leukocytosis disappeared immediately after cholecystectomy. These findings suggest that this was a G-CSF-producing tumor.

Aged↗
PubMed1990

Latent carcinoma of the thyroid manifested by cystic supraclavicular metastasis.

In a 68-year-old Japanese woman, who had a right supraclavicular cyst containing thyroglobulin-rich fluid, metastatic adenocarcinoma was demonstrated in the cyst. A subsequent total thyroidectomy showed a papillary carcinoma measuring 11 mm in the ipsilateral lobe of the thyroid. A high thyroglobulin level in a cervical cyst may facilitate the detection of hidden primary cancer in the thyroid.

Adenocarcinoma, Papillary↗
PubMed1990

High yields of granulosa cell tumors/luteomas in F344 rat ovaries after transplacental administration of N-nitrosobis(2-oxopropyl)amine.

Ovarian tumors were induced at very high incidence in the offspring of F344 rats receiving 3 subcutaneous injections of 10 mg/kg of N-nitrosobis(2-oxopropyl)amine on the 14th, 18th and 20 days of gestation. Histologically, all ovarian tumors were of the granulosa cell tumor and/or luteoma type. Many of them consisted of large, polygonal cells with abundant eosinophilic or vacuolated cytoplasm, arranged in sheets or in a pseudo-palisaded pattern separated by thin fibrovascular stroma, and they exhibited typical luteoma morphological character. The high yields, and the similarities in morphology as well as putative hormonal influence suggest that this experimental system may serve as a good animal model for granulosa cell tumor and/or luteoma development in women.

Animals↗
PubMed1990

Diabetes insipidus after traumata of two extremes in severity.

Two patients with post-traumatic diabetes insipidus (DI) are reported. One had suffered a fatal injury and the other a mild contusion without amnesia before DI developed. These two instances exemplify the wide spectrum of post-traumatic DI and, hence, the importance of ruling out DI even afer a mild closed-head injury.

Adult↗
PubMed1990

[Ultrastructural localization of myelin bodies and acid phosphatase activities in the liver and kidney induced by quinacrine in rats].

Electron microscopic studies were conducted to reveal the ultrastructural aspects of the myelin body and acid phosphatase activity in rats induced by quinacrine, an antimalarial drug. Each of 22 rats in three groups were examined. The first group of control rats was initially given a single i.p. dose (200 mg/kg) of diethylnitrosamine (DEN) only and then fed a CRF-1 basal diet for 8 weeks. The second and third group were treated with DEN or saline, and starting 2 weeks later, were fed a CRF-1 basal diet supplemented with 500 ppm quinacrine for 6 weeks. All animals were subjected to a partial hepatectomy at week 3, and then sacrificed at week 8. Liver and kidney tissues specimens from 2 rats per group were collected for routine electron microscopic study. Furthermore, the activity of acid phosphatase, a key enzyme for lysosomal activity, was also investigated. In this study, tissues were fixed with a solution of 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer. After fixation, tissues were frozen and their 8 microns sections were treated with Gomori's lead nitrate buffer solution, and post-fixed with a 1% osmium solution. After being embedded in Epon 812, ultrathin sections were made. Intracellular myelin bodies were observed in the hepatocytes, interlobular bile duct cells, renal glomerular podocytes and renal tubular cells in the quinacrine treated groups, but not were observed in rats treated with DEN alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1990

[Subchronic oral toxicity study of tannic acid in F344 rats].

A 13-week subchronic oral toxicity study of tannic acid (TA) was carried out in F344 rats at dose levels of 0, 0.025, 0.05, 0.1, 0.2 and 0.4% in the drinking water, to determine appropriate dose levels for a subsequent 2-year carcinogenicity study. The rats were randomly allocated to 6 groups, each consisting of 12 males and 12 females. No animals died during the administration period. There were no significant difference in body weight gain, food consumption and organ weights between the treated and control groups, although a slight decrease in water intake was seen in the 0.4% TA treated group. No specific changes were observed in any parameters in the hematological and biochemical investigations. Histopathological examination, revealed toxic changes in the TA treated male groups, in the form of necrosis in the liver, but toxicologically it was of minor importance. From these results, it was concluded that the provable maximum tolerable dose of TA in the drinking water would be more than 0.4%. In consideration of the avoidance of drinking water, the maximum tolerable dose of tannic acid was determined to be 0.5%, when given in the drinking water.

Administration, Oral↗
PubMed1990

[Toxicity and carcinogenicity studies of musk xylol in B6C3F1 mouse].

Toxicity and carcinogenicity studies of musk xylol were examined in B6C3F1 mice. The LD50 of the chemical was considered to be more than 4000 mg/kg. In the acute toxicity and 14-day repeated-dose oral toxicity studies, tremor was observed in some animals given high doses of the chemical. In the 17-week repeated-dose oral toxicity study, musk xylol was given at dietary dose levels of 0.0375, 0.6%. During the experimental period, almost all mice given 0.3% or more died. There was no difference in the body-weight gain between the treated groups given 0.15% or less and the control group. Histologically, enlargement and irregularity of hepatocyte were found in both sexes given 0.15% or more. Based on the results, the chemical was given at dietary levels of 0 (control), 0.075 or 0.15% for 80 weeks in the carcinogenicity study. Overall tumor incidences in all treated groups of both sexes were significantly higher than those in the respective controls. Combined malignant and benign liver cell tumors increased clearly in both sexes and a significant positive trend for the occurrence of hepatocellular carcinomas was noted in males. Incidences of lung and Harderian gland tumors and lymphomas in treated groups were also slightly higher than those in controls. In addition, incidences and total numbers of malignant tumors increased significantly in treated groups of both sexes, although no dose-relation was evident. The results demonstrated that musk xylol is carcinogenic in B6C3F1 mice of both sexes when given at dose-levels of 0.075 or 0.15% in the diet for 80 weeks.

Administration, Oral↗