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Biomedical subjects

T Obara

Publications and source records attributed to T Obara.

At least 181 records · Page 10Linked to original sources
PubMed1990

Trial of thyroid autotransplantation in patients with Graves' disease whose remnant thyroid has unintentionally been made too small at subtotal thyroidectomy.

Autotransplantation of thyroid tissue was carried out in 5 patients with Graves' disease in order to prevent postoperative hypothyroidism, because the amount of remnant thyroid tissue was estimated to be too small, i.e. from 3 to 5 g. Approximately 0.5 to 2 g of thyroid tissue was cut into small pieces and transplanted into the sternocleidomastoid muscles or the strap muscles. Although the postoperative serum TSH levels were normal or slightly elevated, the serum concentrations of triiodothyronine were within the normal range in these 5 patients at a follow-up study carried out 2 to 7 years after surgery. Thyroid scanning with I-123 or 99mTc-pertechnetate (Tc-99m) revealed radioisotope uptake at the sites of transplantation in 4 of the 5 patients. These findings verify that the implanted thyroid tissues were alive and functioning and that autotransplantation may be a way of preventing postoperative hypothyroidism in patients whose remnant thyroid tissue has unintentionally become too small.

Adult↗
PubMed1990

[Evaluation of thrombus scintigraphy using 67Ga-deferoxamine-dialdehydestarch-fibrinogen in patients with internal A-V shunt].

We evaluated the diagnosis of thrombus and the effect of antithrombic therapy by using 67Ga-DFO-DAS-Fibrinogen (67Ga-Fbg.) scintigraphy in vivo. The 11 patients with chronic renal failure had the operation of the internal A-V shunt. The two groups were divided the group I (the patients were injected 67Ga-Fbg. within 5 days after the operation of A-V shunt) from the group II (the patients were injected 67Ga-Fbg. from 7 months to 6 years after A-V shunt). We examined 72 h after the injection of 67Ga-Fbg. in all patients. In group I, the scintigraphy showed the deposition of 67Ga-Fbg. in all 5 patients, but 3 patients were given dipyridamole (75-300 mg). The scintigraphy examined 3 weeks after A-V shunt were negative in 2 patients in group I. In group II, the scintigraphy showed the deposition of 67Ga-Fbg. in the two of 6 patients. Within 5 day after A-V shunt, we observed there was the tendency of the thrombus formation. The scintigraphy of 67Ga-Fbg. was useful for the detection of thrombus in vivo.

Adolescent↗
PubMed1990

[Persistent left superior vena cava to left atrial communication detected with radionuclide angiography: a case report].

A persistent left superior vena cava (PLSVC) is the common clinical congenital abnormality of the greater central veins. This anomaly may occur as an isolated lesion, but rarely it is significantly associated with other congenital cardiac lesions, particularly it drain into the left atrium. We recently encountered a patient in whom PLSVC to left atrial communication with atrial septal defect was diagnosed on the basis of radionuclide angiography with Tc-99m pertechnetate. Radionuclide angiography might be the noninvasive study of choice in patients suspected of having PLSVC by the clinical findings or chest roentgenography.

Adolescent↗
PubMed1990

[Analysis of subsets of colonic mucosal lymphocyte in ulcerative colitis by two color flow cytometry].

To assess how the immunological events occur in the colonic mucosa in patients with ulcerative colitis, it is thought to be important to evaluate the subpopulations and/or subsets of mucosal lymphocytes. In this point of view, we assayed those by lymphocyte isolation techniques and two color flow cytometry. Although our results showed no disease-specific abnormalities of the percentages of CD3, CD4, CD8, CD20, and HLA-DR (+) cells in PBL (peripheral blood lymphocyte) nor CML (colonic mucosal lymphocyte), these subsets of CML appeared to be altered according to the grade of severity of inflammation. In our cases, the HLA-DR (+) cell and CD4 population were larger in severely inflamed mucosa. Furthermore, fluorescence intensities of HLA-DR antigen of CD20 population in CML were greater than those in PBL. These results suggest that the B cell-mediated mechanisms may play an important role in maintaining the severe inflammation, and the clinical significance of these studies are discussed.

Adolescent↗
PubMed1990

[Detection of proliferative cells in colorectal carcinomas and adenomas by monoclonal antibody to DNA polymerase alpha].

DNA polymerase alpha is an endogenous DNA replication enzyme expressed in all cells in a proliferation cycle. An immunoperoxidase method and the monoclonal antibody to DNA polymerase alpha were used to identify proliferating cells in colorectal carcinomas (n = 35) and adenomas (n = 43). The labeling index (L.I.) in colorectal carcinomas was 51.6%, being significantly higher than 28.6% in adenomas. The L.I. in colorectal carcinomas correlated with clinical staging (stage I: 33.1%, stage II and III: 49.5%, stage IV and V: 66.9%). Furthermore, the L.I. had a tendency to elevate as carcinoma deeply invaded (pm: 25.8%, ss-s or a1-a2: 52.2%, si or ai: 67.5%). The L.I. in adenoma was related to the degree of atypia. The L.I. in adenomas with mild atypia, with moderate atypia, and cancer in adenoma were 18.3%, 31.5%, and 47.0%, respectively. And the L.I. of cancer in adenoma had no significant difference in advanced carcinomas (47.0% vs 51.6%). These results suggest that the L.I. is useful as a marker for evaluating the degree of biological malignancy of human colorectal carcinomas and the degree of histopathological atypia of adenomas.

Adenocarcinoma↗
PubMed1990

[Flow cytometric DNA analysis of papillary carcinoma of the thyroid using paraffin-embedded specimens].

A flow cytometric DNA analysis of papillary thyroid carcinomas has been performed on paraffin-embedded specimens, in order to determine the clinical usefulness of this method by defining the degree of the biological malignancy. Fifty-eight patients with papillary carcinomas were followed from 2 to 8 years. They were classified according to their prognosis into three groups: non-recurrent (47 patients), recurrent (5 patients), and a deceased group (6 patients). Aneuploidy was found in 6 (10.3%) of the total 58 patients. It was more frequently detected in the recurrent (40%) and in the deceased (33.3%) groups than in the non-recurrent group (4.3%). Higher proliferating index values were observed in the deceased group than in the recurrent and non-recurrent groups. These results indicate that a DNA analysis, using routine paraffin-embedded materials, is a useful adjunct in the determination of the degree of the biological malignancy of a papillary carcinoma.

Adult↗
PubMed1990

[Immunohistochemical studies on the expression of epidermal growth factor (EGF) in human colorectal cancers].

The expression of epidermal growth factor (EGF) was studied immunohistochemically in a total of 92 human colorectal cancers to examine whether EGF was expressed in relation to its degrees of malignancy. Significantly high incidence of EGF was observed in advanced cancers than in early cancers. In the tissues of advanced cancers, tumor cells having EGF-immunoreactivity tended to be more frequently and intensely observed in deeply invasive tumor cells than in superficial tumor cells. Regarding macroscopic and histologic types, incidence of EGF-immunoreactivity was significantly higher in infiltrating types and in differentiated types than in localized types and in poorly differentiated types, respectively. Cases with poor prognosis and in advanced stages showed high positive rate of EGF-immunoreactivity. These results suggest that the expression of EGF may serve as a biologic marker for the degree of malignancy in human colorectal cancers.

Adenocarcinoma↗
PubMed1989

High risk of mother-to-child transmission of HTLV-I in p40tax antibody-positive mothers.

A new enzyme-linked immunosorbent assay (ELISA) for detecting the antibody to a human T-lymphotropic virus type I (HTLV-I) tax gene product, p40tax, has been developed. By this ELISA method, we have investigated the relationship between the presence of p40tax antibody in HTLV-I-infected mothers and the virus transmission rate from mothers to their children. The rate of mother-to-child transmission of HTLV-I was higher in p40tax antibody-positive mothers than in antibody-negative ones. Thus, the presence of p40tax antibody may indicate an increased risk of vertical transmission of HTLV-I.

Adolescent↗
PubMed1989

Evaluation of a one-way airflow system in an animal room based on counts of airborne dust particles and bacteria and measurements of ammonia levels.

Air cleanliness in the working area of an animal room equipped with a conventional turbulent flow air distribution systems was compared with that in a similar room fitted with a one-way-flow air distribution system; in this, the supply air flowed from the working area through the racks of cages and was removed from the exhaust side. Before the introduction of animals, the air in the working and exhaust areas of both rooms was ascertained to be Class 100. With animals in situ, however, whereas in the turbulent airflow room both the workspace and exhaust air reached about Class 10,000 (with particle counts, bacterial counts and ammonia levels being almost the same) in the one-way-flow room, the air in the work space only went up to about Class 1000. With the addition of sliding doors or curtains in front of the rack in the one-way-flow room the work space air was maintained at Class 100 with almost no dust particles over 1 microns in size, airborne bacteria or ammonia being detectable. A comparison of all factors measured showed that whereas in the turbulent flow room the contamination of the work space air was 91% of that of the exhaust air, in the one-way-flow room it was only 47%, with curtains added this was reduced to 7% and with sliding doors to only 2%. In the latter case, contamination levels increased markedly on both sides during and immediately after cage changing, but recovered to the pre-cage changing levels within 30 min in the personnel working area and within 60 min on the exhaust side.

Air Conditioning↗
PubMed1989

Functioning parathyroid lipoadenoma--report of four cases: clinicopathological and ultrasonographic features.

Functioning parathyroid lipoadenoma (hamartoma) composed of abundant adipose or myxomatous stroma and epithelial cell nests is an unusual cause of primary hyperparathyroidism. We report herein four new cases. None of them belongs in the category of multiple endocrine neoplasia or familial hyperparathyroidism. The clinical manifestations and the laboratory findings are indistinguishable from those of the usual forms of primary hyperparathyroidism. Ultrasonography of the neck demonstrated an enlarged parathyroid gland as a hyperechoic mass in the two patients tested. At operation in each case, a single enlarged gland was found and resected, the weight being 3, 0.3, 0.45 and 1 g, respectively. The patients are normocalcemic 1 to 10 years after surgery. Pathological examination disclosed that the lesions were consistent with lipoadenoma or its variants. On reviewing 20 cases of functioning lipoadenoma which were reported in the literature, including the present cases, we found that the size of the tumors varied and a functioning lipoadenoma is hence by no means unusually large as previously reported. Without knowledge of this specific clinicopathologic entity, the lesion may be overlooked at the preoperative localization study and misdiagnosed as a normal or hyperplastic parathyroid.

Calcium↗
PubMed1989

Expression of insulin-like growth factor receptors in primary human thyroid neoplasms.

The presence of IGF-I receptors was demonstrated in normal and neoplastic tissues of human thyroid. Binding of (125I)IGF-I to thyroid membranes was dependent on time and temperature of incubation, and maximal binding was achieved at 4 degree C and 18 h of incubation. (125I)IGI-I binding was dose-dependently displaced by unlabelled IGF-I; half-maximal inhibition occurred at concentrations of 10-20 milligrams. IGF-II and insulin had relative potencies of 5 and 1% compared with IGF-I. Scatchard analysis of binding data revealed a single class of IGF-I receptors with high affinity (Ka: 1.2-8.6 x 10(9) 1/mol) in normal thyroid tissues. Affinity cross-linking and autoradiography demonstrated the type IIGF receptors. Specific binding of (125I)IGF-1 in thyroid cancer tissues (9.69 +/- 2.07% per 200 micrograms protein; mean +/- SEM, N = 8) was significantly (p less than 0.05) higher than that in the surrounding normal tissues (3.03 +/- 0.35%, N = 8). In contrast there was no difference in the binding between adenoma tissues (4.19 +/- 0.53%, N = 5) and the adjacent normal tissues (2.94 +/- 0.24%, N = 5). The higher IGF-I binding in cancer tissues was due to an increase in the binding capacity without any change in the affinity. The presence of IGF-I receptors suggests a possible role of IGF-I and its receptors in the growth of thyroid cancer cells.

Adenoma↗
PubMed1989

[Detection of keratin mRNA and human origin of xenotransplanted human tracheobronchial epithelium by in situ hybridization].

An in situ hybridization method was applied to detect keratin mRNA expression and human origin of xenotransplanted human tracheobronchial epithelium into nude mice. Tissues from eight tracheas repopulated with cells from five different donors were used. A K6 (56 kd) human keratin cDNA (KA-1) and a K14 (50 kd) cDNA (KB-2) were radiolabeled with 3H-dATP/TTP and used as probes to study changes in keratin mRNA expression in various lesions of the tracheobronchial epithelium. To identify human tissues xenotransplanted into nude mice, high-molecular-weight DNAs extracted from human or mouse tissues were sonicated, nick-translated with 32p-dCTP, and used as probes. Dot-blot hybridization of 32p-labeled DNA probes revealed clear species-specific signals and cells of human origin were distinguishable by in situ hybridization with sonicated human DNA probe. In situ hybridization with either KA-1 or KB-2 probe showed similar localization of silver grains in all histologic types in consecutive tissue lesions of xenotransplanted tracheobronchial epithelia. Very few grains were seen over cells of simple, pseudostratified, or stratified epithelia two to three cell layer thick. Nonkeratinizing stratified hyperplastic epithelia of more than three cell layers showed uniform localization of grains throughout the lesions. In contrast, epidermoid metaplasias exhibit a dense and localized pattern of grains on the basal and parabasal cell layers with a decrease in grain density toward the surface layers. In situ hybridization with sonicated DNA probes provided a powerful tool for verifying the human origin of xenotransplanted tissues in nude mice, showing several advantages, simple preparation of probes, high sensitivity, and applicability to all types of tissues and cells. With KA-1 and KB-2 probes, the different localization pattern of keratin mRNAs in different epithelial lesions were demonstrated. It was of particular interest that an ordered program of keratin mRNA expression proportional to the level of cellular differentiation was observed in epidermoid metaplasias. Both of these probes serve as keratinization markers of human tracheobronchial epithelial lesions.

Animals↗
PubMed1989

[Adrenal incidentaloma--report of 14 operated cases and analysis of 4-year autopsy series of Japan].

During the last 7 years, operation was performed for 94 cases of adrenal tumor in our series, of which 14 were incidentally found by abdominal computed tomography or echography. They included 9 cases of pheochromocytoma, 1 of Cushing's syndrome, 3 of ganglioneuroma and 1 of cortical adenoma. Five of 9 pheochromocytoma cases were devoid of hypertension, but all 9 cases had abnormally high levels of urinary catecholamines and/or their metabolites. The 4-year autopsy series of Japan (1980-1983) included about 153,000 cases. Except the metastatic tumors, the following lesions were incidentally found in the adrenal gland: 310 of cortical adenoma, 153 of cortical hyperplasia, 39 of pheochromocytoma and 17 cases of neurogenic tumors. Some of the cortical adenomas are presumed to be more than 1 cm in diameter. So, they are expected to be found incidentally, more frequently in the future. Surgery is not necessary for most of them, except for functioning tumors. Most of the pheochromocytomas are presumed to be hormonally active, and should be treated surgically. It is probable that these functioning tumors had been missed clinically, especially in the elderly persons. Neurogenic tumors and myelolipomas may be left in place, when malignancy can be ruled out.

Adenoma↗
PubMed1989

[Hyperkinetic mutism within the scope of consciousness disorder in a case of systemic lupus erythematosus].

A thirty-year-old housewife, who had been diagnosed as SLE, had been hyperkinetic and mute for 13 months after reiteration of manic-depressive episodes. In this condition she walked around without aim, ate and drank only with nursing help, and could not understand the circumstances around her; she was incontinent of urine and feces. Serological examination did not show any abnormal results during psychic exacerbation. She recovered dramatically by electroconvulsive therapy, and was completely amnestic about the past 15 months. Because her mental state was considered to be limited consciousness, it might be possible that her hyperkinetic and mute state is situated between twilight state and akinetic mutism.

Adult↗
PubMed1988

Ultrastructural analysis of neurofibrillary tangles of Alzheimer's disease using computerized digital processing.

The ultrastructure of neurofibrillary tangles of Alzheimer's disease was analyzed by computerized digital processing of electron micrographs. Processing of the electron micrographs consists of four steps: digitizing the electron micrograph, Fourier transformation, noise filtering and inverse Fourier transformation and Laplacian operation. In the present study, we have confirmed that neurofibrillary tangles are composed of a pair of helical filaments (PHF), which appear characteristically as an unbranched rigid structure. The periodicity of PHF is 78 nm on the diffractogram. The dimensions of PHF obtained by our analysis, although basically similar to those described earlier by other investigators using conventional techniques, more precisely defines its structural conformation. We have also demonstrated that the spatial relationship of two filaments appears symmetrical after two-way tilting of the specimen about the axis of rotation. Our observations emphasize the importance of digital image processing as an effective tool for structural analytical research in biology and medicine.

Actin Cytoskeleton↗