Biomedical subjects

T Tagami

Publications and source records attributed to T Tagami.

At least 55 records · Page 3Linked to original sources

PubMed1992

A point mutation of the T3 receptor beta 1 gene in a kindred of generalized resistance to thyroid hormone.

Mutations of the thyroid hormone receptor (TR) beta 1 gene have recently been detected in several unrelated families with generalized resistance to thyroid hormone (GRTH). We now report a novel point mutation in the TR beta 1 gene in a case of a Korean-Japanese kindred. The intracellular localization and the amount of TR proteins were considered to be normal by the immunocytochemical study of cultured skin fibroblasts from the patients using anti-T3 receptor antibody. The cDNA of the T3-binding domain of the TR beta 1 gene, synthesized from the total RNA of the patients' fibroblasts, was amplified by the polymerase chain reaction, and was sequenced. A point mutation, A to G, in one allele at 1612 resulting in an amino acid substitution from lysine 438 to glutamic acid was detected. The same mutation was identified in one allele in each of the affected members. In vitro translation products of the mutant TR beta 1 gene showed decreased T3-binding activity. These data suggest that a TR mutation is predominantly responsible for GRTH, irrespective of ethnic background.

Adolescent↗

PubMed1992

Giant fistula between the right coronary artery and the left ventricle: diagnostic significance of right posterior oblique chest radiograph.

Congenital coronary artery fistulas are uncommon. The prevalence of coronary artery fistulas in adults has been estimated as 0.13% [1]. Most of these fistulas communicate with the right atrium or ventricle or with the pulmonary artery; those emptying into the left atrium or ventricle are quite rare [2, 3]. Usually, patients with coronary artery fistula do not have clinical symptoms, and their chest radiographs do not show the corresponding shadow because the fistula is hemodynamically insignificant. When the fistula is large, however, chest radiographs show the secondary hemodynamic changes, such as cardiac enlargement or increased pulmonary vasculature, depending on the emptying site. Moreover, the silhouette of the dilated tortuous vessel itself can be seen on the chest radiograph. We have examined four patients, each of whom had a giant fistula in the right coronary artery emptying into the left ventricle, proved by coronary angiography. In this essay, we illustrate the chest radiographs of these patients and describe the radiologic features that permit a specific diagnosis or suggest a coronary artery fistula.

Adult↗

PubMed1992

[Practical use of mortality statistics and mass examination results by health workers in the local authority of the community].

In Kochi prefecture, the prefectural health service bureau tabulates both mortality statistics and mass examination results for each community and the tabulated report is sent annually to public health services staff in each local authority. While recognizing its limitations, methods of how to use the annual report are demonstrated. For example comparison of the mortality statistics and the mass examination results of the male population of A town, which is administered by Susaki Health Center, to that of the combined male population of all the towns administered by the health center shows that although the mortality rate for cerebrovascular disease for the A town-male population had been much higher than that of the combined male population in the early 1980's, the difference disappeared in the late 1980's. On the other hand, prevalence of systolic hypertension in the A town-male population continued to be higher than that for the combined male population in the late 1980's. Therefore hypertension prevention programs appears to still have significance in the A town-male population. Certain weaknesses exist in this annual report. In the comparison of mass examination results among different populations, the presence of selection bias of those receiving examinations should be considered. Standardization of mass examination procedures and quality controls of the examinations should also be considered. To get health workers to utilize the annual report further, the reported items should be improved. Particularly useful would be tabulation by residential subdivision and occupation.

Community Health Services↗

PubMed1991

Adult and neonatal human brain: diffusional anisotropy and myelination with diffusion-weighted MR imaging.

Diffusional anisotropy of human brain was investigated clinically in six adult volunteers, eight premature neonates, and three infants aged 5-10 months. Diffusion-weighted magnetic resonance imaging was performed with gradient b of 450 sec/mm2. The direction of diffusion-sensitive gradients was changed among x, y, and z axes according to the orientation of neurofibers in white matter. T1- and T2-weighted images also were obtained for evaluation of myelination. Diffusional anisotropy was demonstrated in white matter in the adults. Extensive signal attenuation was observed when gradients were parallel to white matter fibers. Conversely, in neonates, diffusional anisotropy of white matter, in which no myelination was shown on T1- and T2-weighted images, was weak. Diffusional anisotropy was more distinct after brain maturation, as observed in adult white matter. Detection of diffusional anisotropy is useful in evaluating neonatal brain development and various white matter disorders.

Adult↗

PubMed1991

Demonstration of nuclear 3,5,3'-triiodothyronine receptor proteins in gonadotrophs and corticotrophs in rat anterior pituitary by double immunohistochemical staining.

Previously we raised an antiserum (4BII) against nuclear T3 receptor (NT3R), which recognizes c-erb A/NT3R alpha 1 and beta, but not alpha 2. An immunohistochemical study using 4BII revealed that among the tissues examined, the cerebral cortex, anterior pituitary, and thyroid gland exhibited strong immunostaining in the nuclei. In the present study we examined the localization of NT3R proteins in individual cell types of rat anterior pituitary, using the technique of double immunostaining with 4BII and antibodies against pituitary hormones. The cryostat sections and paraffin sections of rat pituitary were incubated with 4BII at 4 C overnight. The NT3R proteins were visualized as brown in the nuclei by avidin-biotin peroxidase staining. The control sections incubated with an antiserum which had previously absorbed with c-erb A peptide or an inactive antiserum showed very poor nuclear staining under the same condition. After being washed with 0.1 M glycine-HCl buffer (pH 2.2) for 2 h to remove 4BII, the sections were incubated with antiserum against individual anterior pituitary hormones at 4 C overnight. Using the method of alkali phosphatase/naphthol/Fast blue staining, the peptide hormones in the cytosol were stained blue. Double staining with 4BII and anti-FSH beta or anti-LH beta anti-serum clearly demonstrated that gonadotrophs contained the NT3R proteins. Similarly, the NT3R proteins in corticotrophs were demonstrated by the immunostaining with 4BII and anti-ACTH antiserum. As expected, the NT3R proteins were present in somatotrophs, thyrotrophs, and lactotrophs. On the other hand, folliculo-stellate cells, which are nonhormone secreting cells and are identified by their S-100 protein immunoreactivity, were stained by 4BII only faintly. The present study demonstrated the existence of NT3R proteins not only in somatotrophs, thyrotrophs and lactotrophs but also gonadotrophs and corticotrophs, suggesting some action of thyroid hormone through the receptor in these cells.

Adrenocorticotropic Hormone↗

PubMed1991

[Detection of pulmonary tuberculosis. Special characteristics of patients detected while receiving treatment for other diseases].

Tuberculosis (TB) detection is mainly classified as being either passive case-finding, at a hospital, or positive case-finding through a mass screening. Pulmonary TB patients detected while being examined for other complaints at a hospital are classified as passive findings. It is suspected that these patients have special characteristics which separate them from patients that are detected only after the onset of TB symptoms. The aim of this study is to elucidate those special characteristics of patients where detection occurred while being examined for other diseases by comparing them with patients detected by the other means. A survey was conducted on 686 pulmonary TB patients, diagnosed between 1986 and 1988, from the area served by the Kochi Prefectural Chuo Health Center, with the following results. 1) Among the 533 patients who were detected at a hospital, and excluding those detected by mass screening, 331 patients were detected only after the onset of TB symptoms (group B), with 202 patients being treated for other diseases before being diagnosed as having TB (classified as group A). In group A, 130 patients were detected because of manifesting additional symptoms related to tuberculosis such as fever and cough (group A-1), while the remaining 72 patients were detected by chance while being examined for other diseases (group A-2). 2) The number of elderly people and relapse cases was higher in group A compared to B group and the group detected by mass screening. 3) Symptoms, the rate of tubercle bacillus positives, and the period from the onset of symptoms to diagnosis (defined delay) in group A-1, were similar to group B. In group A-2, symptoms and the rate of tubercle bacillus positives were less than those of the other groups. 4) From the above findings, it is concluded that passive case-findings should be classified into 3 distinct groups.

Adolescent↗

PubMed1991

[Measurement of intrahepatic shunt using Rutland method].

Intrahepatic shunt ratio was calculated from the fraction of the uptake constant and the blood background, analyzing the data of 99mTc-(Sn)-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) hepatobiliary imaging by Rutland method. Shunt flow and total hepatic blood flow (THBF) were also calculated from the values for the effective hepatic blood flow (EHBF) estimated from the blood clearance technique. In 15 cases of normal volunteer, the average of the shunt ratio, shunt flow, and THBF were 18.4 +/- 5.4 (S.D.)%, 137.8 +/- 49 ml/min, and 753 +/- 83.2 ml/min, respectively. In 8 cases of chronic hepatitis, the values were 35.2 +/- 2.6%, 276 +/- 55.4 ml/min, and 794.1 +/- 119.4 ml/min, respectively. In 12 cases of liver cirrhosis, the values were 51.4 +/- 12.6%, 353.9 +/- 141.3 ml/min, and 685.6 +/- 174.8 ml/min, respectively. In cases of chronic hepatitis and liver cirrhosis, in comparison with normal cases, the values for the shunt ratio and shunt flow were significantly increased (p less than 0.001) and those for EHBF were significantly decreased (p less than 0.001), but those for THBF were not significantly altered. There was a significant inverse correlation between the shunt ratio and EHBF (r = -0.842) in all 35 cases. This method is considered to be useful for differential diagnosis, estimation of the grade of the diseases, and evaluation of pathophysiology of various diffuse liver diseases.

Chronic Disease↗

PubMed1990

[Quantitative assessment of mineral content in metacarpal bone with Fuji computed radiography].

A new microdensitometry method for quantitative assessment of bone mineral content using Fuji computed radiography (FCR) was developed and the results were compared with those obtained by the conventional film-screen method. Using both methods, X-ray pictures of the 2nd metacarpal bone were taken with a reference aluminum step wedge in nine normal subjects and nine parameters representing the width and density of bone marrow and cortex were calculated in the middle of the bone shaft. Interobserver reproducibility assessed for three parameters was significantly higher in the FCR method than the conventional one. The value of sigma GS computed by the FCR method, that is equivalent to the net bone density of the transverse section of the shaft, showed higher correlation with the one obtained by computed tomography in comparison with the conventional method. In our FCR method, moreover, interobserver reproducibility and accuracy was improved by employing automatic manipulation as much as possible in the process of calculation. The exposure dose in the FCR method could be reduced to half of the one in the conventional method without deteriorating the accuracy. In conclusion, our new microdensitometry method with FCR provides high accuracy and good reproducibility for the measurement of bone mineral content with small exposure dose and is likely to be useful for the long-term follow-up of the osteoporotic patients from the variety of causes.

Adult↗

PubMed1990

Characterization of interaction between nuclear T3 receptors and antiserum against cellular-erb A peptide.

In our previous study, we raised a polyclonal antiserum against a synthetic 15 amino acid peptide encoding the putative hormone binding domain of c-erb A, which not only inhibited T3-binding to rat liver nuclear T3 receptor (NT3R) but also immunoprecipitated [125I]T3-NT3R complex. In the present study, interactions between this antiserum (4 BII-immunoglobulin G (IgG] and NT3R were further characterized. 4BII-IgG interefered T3 from binding to rat liver NT3R both in the nuclear extract and in isolated nuclei in a similar manner. Preincubation with 4BII-IgG decreased the association constant value with no effect on maximal binding capacity of NT3R. Lineweaver-Burk plot revealed competitive inhibition of T3-NT3R binding. Both the inhibition of T3 binding and immunoprecipitation of NT3R by the antiserum were similarly observed with rat liver, kidney, brain, and testis, and human kidney nuclear extract. Since the polypeptide sequence which was used for immunization is highly homologous between c-erb A alpha 1 and beta, it is likely that 4BII-IgG recognizes both c-erb A alpha 1 and beta in various tissues. On the contrary, 4BII-IgG did not interfere with T3 binding to rat liver cytosol T3-binding protein and thyroxine-binding globulin (TBG) prepared from human serum, nor immunoprecipitated these binding proteins labeled with [125I]T3. The binding protein for reverse T3 (NrT3BP) in the rat liver nuclear extract was neither immunoprecipitated nor influenced in its rT3-binding activity by 4BII-IgG. When the immune complex between the nuclear extract and 4BII-IgG was removed by antirabbit IgG goat serum, the remaining T3-binding activity was reduced by 87%, while no rT3-binding activity was immunodepleted, suggesting that NrT3BP is a protein different from NT3R. The data show that the antiserum against c-erb A peptide recognizes NT3R specifically with no distinction between difference in tissues and species. Carboxyl-terminal region of c-erb A/NT3R is critical for T3-binding.

Animals↗

PubMed1990

Immunohistochemical localization of nuclear 3,5,3'-triiodothyronine receptor proteins in rat tissues studied with antiserum against C-ERB A/T3 receptor.

We have previously raised an anti-c-erb A peptide antibody (designated 4B II) which immunoprecipitated in vitro transcription/translation products of c-erb A alpha 1 and beta. 4B II could recognize nuclear T3 receptor (NT3R) without distinction between difference in species and tissues. Using 4B II, we studied immunohistochemical localization of NT3R proteins in various tissues of the rat. Cryostat sections (4-6 microns) of selected rat tissues were incubated with 4B II at 4C overnight, followed by fluorescein-isothyocianate-conjugated anti-rabbit immunoglobulin G for 60 min at 25 C. The cellular localization of fluorescence in all tissues examined was exclusively nuclear. Under the same conditions, control sections stained with antiserum which had previously absorbed with c-erb A peptide or inactive serum showed no specific staining. In the brain the large nuclei, supposed to be neuronal, were strongly stained in the cerebral cortex and the granular layer of the cerebellum. In the kidney, cells in the glomerulus, the distal, but not the proximal, tubules, and the collecting ducts exhibited nuclear staining. Nuclear fluorescence was observed homogeneously in the heart and liver, but the intensity was much weaker in the latter. Less intense fluorescence was seen in the testis and spleen, although specific immunostaining was clearly observed in the nuclei of spermatocytes, Leydig cells, and the heads of the sperms in the testis, and many lymphocytes in the spleen. Nuclei of follicular cells of the thyroid exhibited very strong fluorescence, suggesting existence of plenty of NT3R proteins. The anterior pituitary showed strong immunostaining in most nuclei, and clear nuclear fluorescence was also detected in the intermediate lobe of the pituitary. The present study showed that NT3R distributes selectively in certain types of cells in many tissues and that the content of NT3R proteins seems to correlate with the concentration of c-erb A mRNA alpha 1 and beta among many organs.

Amino Acid Sequence↗

PubMed1990

Effect of stripping thyroxin from thyroxin-binding globulin on the measurement of free thyroxin in serum by equilibrium dialysis and by radioimmunoassay.

In considering factors that might influence measurement of free thyroxin (T4), we evaluated the proportion (%) of T4 that could be stripped from thyroxin-binding globulin (TBG). The percentage of free T4 was measured in serially diluted sera from four normal subjects, four patients with hyperthyroidism or hypothyroidism, four pregnant women, and four malnourished subjects with low TBG. The critical percentage of stripping was determined by the product of the percentage free T4 and the critical dilution factor (the point where the percentage free T4 began to decrease). The mean values obtained for the respective patient groups--6.38%, 2.76%, 16.73%, 9.75%, and 4.28%--were proved to be related to the rate of saturation of TBG with T4. Values for percentage stripping determined with the "GammaCoat two-step RIA" and the "LiquiSol RIA" were well within the critical percentage stripping by equilibrium dialysis, except in the case of low-TBG serum as measured by LiquiSol RIA. Free T4 concentration as measured by LiquiSol RIA decreased as sample volume decreased. These findings were ascribed to the relatively high values for percentage stripping in the LiquiSol RIA, which led to erroneously low values for free T4.

Adult↗

PubMed1989

Recognition of rat liver and kidney nuclear T3 receptors by an antibody against c-erb A peptide.

It has been reported that c-erb A encodes nuclear T3 receptors (NT3R). Based on the sequence of c-erb A cDNA, we synthesized a polypeptide consisting of 15 amino acids, the sequence of which has high homology between c-erb A alpha 1 and beta. The antibody against this c-erb A peptide not only immunoprecipitated rat liver and kidney NT3R but also inhibited T3 binding to NT3R. In a displacement study, the inhibition of [125I]T3-binding by the antibody was parallel to that by T3 in terms of the concentration of the competitor added in the incubation mixture. Scatchard analysis revealed that the antibody decreased the value for the association constant in a dose dependent manner. The antibody did not bind T3 itself. The results show that the antibody against c-erb A peptide recognizes rat liver and kidney NT3R and that the sequence encoding this peptide, the closest carboxyl-terminal of c-erb A may be critical or at least closely related to the hormone binding.

Animals↗

PubMed1988