Congenital hypothyroidism caused by a mutation in the Na+/I- symporter.
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Biomedical subjects
Publications and source records attributed to K Miyai.
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A case of small cell carcinoma of the prostate without a primary lesion in the lung was reported. The cancer was diagnosed after the patient complained of lumbago caused by bone metastasis. The tumor was 5.9 x 5.0 x 4.6 cm. The patient was treated with 4 courses of chemotherapy using cisplatin and etoposide. The tumor diminished to 4.0 x 4.0 x 3.5 cm after completion of the 4 courses of treatment. Prostatic antigen levels were less than 1.0 ng/mL during the therapy. Neuron-specific enolase levels were 35.9 ng/mL at the beginning of therapy, and decreased to 7.4 ng/mL after completion of 4 courses of treatment. The patient died 3 months after the completion of treatment. This regimen had some value for inhibiting the growth of small cell carcinoma.
We report intra-individual and seasonal variations of thyroid function tests in healthy subjects. Blood samples were obtained from thirteen healthy males and seven healthy females every two weeks over a period of one year, and totally 25 samplings of each were made. Serum thyrotropin (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) were measured after the completion of the sampling. The 25 samples from each subject were always assayed with the same assay run. Variations of FT4 and FT3 in each subject were narrow and approximately one-third of normal reference ranges. The magnitude of individual variation of TSH values was proportional to the average of TSH in each individual. Serum TSH and FT3 values during winter were significantly higher than those during summer, but such change was not observed on serum FT4.
Ionizing radiation can functionally alter the immune system and break self-tolerance. High dose (42.5 Gy), fractionated (2.5 Gy 17 times) total lymphoid irradiation (TLI) on mice caused various organ-specific autoimmune diseases, such as gastritis, thyroiditis, and orchitis, depending on the radiation dosages, the extent of lymphoid irradiation, and the genetic background of the mouse strains. Radiation-induced tissue damage is not the primary cause of the autoimmune disease because irradiation of the target organs alone failed to elicit the autoimmunity and shielding of the organs from irradiation was unable to prevent it. In contrast, irradiation of both the thymus and the peripheral lymphoid organs/tissues was required for efficient induction of autoimmune disease by TLI. TLI eliminated the majority of mature thymocytes and the peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or bone marrow cell suspensions (prepared from syngeneic nonirradiated mice) within 2 wk after TLI effectively prevented the autoimmune development. Depletion of T cells from the inocula abrogated the preventive activity. CD4+ T cells mediated the autoimmune prevention but CD8+ T cells did not. CD4+ T cells also appeared to mediate the TLI-induced autoimmune disease because CD4+ T cells from disease-bearing TLI mice adoptively transferred the autoimmune disease to syngeneic naive mice. Taken together, these results indicate that high dose, fractionated ionizing radiation on the lymphoid organs/tissues can cause autoimmune disease by affecting the T cell immune system, rather than the target self-Ags, presumably by altering T cell-dependent control of self-reactive T cells.
In order to study the bioactive sites of the glycoprotein hormones, we have prepared five point mutants on the CMGCC (Cys28-Met29-Gly30-Cys31-Cys32) region of the human alpha-subunit by using site-directed mutagenesis. Each mutant human chorionic gonadotropin (hCG) agr; cDNA and a wild-type hCG beta cDNA were transcribed by T3 RNA polymerase, and the mixture of the hCG alpha mRNA and hCG beta mRNA was microinjected into Xenopus laevis oocytes. All five mutant hCGs produced in oocyte culture supernatants were detected as immunoreactive forms by enzyme immunoassay. In contrast, four mutants (Cys28-->Tyr28, Gly30-->Arg30, Ala30, Asp30) were devoid of biological activity in vitro bioassay using the production of testosterone with mouse Leydig cells. These results indicate that the CMGCC region in the alpha-subunit, particularly the cysteine residue at position 28 and the glycine residue at position 30, plays an important role in the biosynthesis of glycoprotein hormones.
Recent developments in medical care have required certified clinical laboratory physicians. The background of the "Certification System for Certified Clinical Laboratory Physicians" and the "Curriculum for Postgraduate Training in Clinical Pathology/Laboratory Medicine" was reviewed. The Education Committee of the Japan Society of Clinical Pathology is offering a new curriculum. The curriculum is planned on the basis of "General Instructional Objectives (GIOs)" and "Specific Behavioral Objectives (SBOs)". The "Guidelines for Basic Postgraduate Clinical Training" has already offered. The advanced training program includes seven required courses which will be planned according to seven basic GIOs as well as specific GIOs and SBOs. This forum is expected to be useful in planning the new curriculum.
In 1971, the first case of congenital isolated thyrotropin (TSH) deficiency was reported by Miyai et al. Subsequently, the same group reported that the disease was caused by a missense mutation in the CAGYC region of the TSH-beta gene (substitution from G to A in exon 2 which altered the Gly29 [GGA] to Arg29 [AGA]). At present the same mutation was reported in 6 patients in 5 Japanese families. Dacou-Voutetakis reported 3 patients with a nonsense mutation in exon 2 (Glu12 [GAA] to Ter [TAA]) and Rajan reported 3 patients with bioinactive TSH caused by a frameshift mutation in exon 3 (Cys105 [TGT] to Val105 [*GTA] and Val114 [GTA] to Ter [TAG]). Significance of C-X-G-X-C motif for biosynthesis of glycoprotein hormones and mass screening for early diagnosis of this disease were discussed.
We report herein a case of a 68-year-old Japanese woman in whom calcification of the portal vein was recognized by plain abdominal X-ray radiograph and computed tomography (CT) scan when she presented with repeated thrombosis of the portal system. Following emergency small bowel resection for intestinal necrosis caused by superior mesenteric vein thrombosis, hematological studies revealed the association of dysplasminogenemia. A review of 21 cases of portal vein calcification reported between 1940 and 1990 revealed the average age to be 53.7 +/- 10.2 years and the male/female ratio 17:4. Although the majority of cases suffered from portal hypertension (81%), only 38% had any evidence of liver cirrhosis, while 52% had normal liver function, being comparable to idiopathic portal hypertension. The calcified lesions were located in the portal vein in 100% of cases, the splenic vein in 62%, the superior mesenteric vein in 33%, and the inferior mesenteric vein in 0%. The precise etiology of the calcification was not elucidated in any of the reviewed cases. The patient reported herein is the first reported case of portal vein calcification due to repeated thrombosis of the portal system caused by dysplasminogenemia, which could be accounted as a cause of idiopathic portal hypertension.
Keratin 8 (mK8) and its partner keratin 18 (mK18) are the first intermediate filament proteins expressed during mouse embryogenesis. They are found in most extraembryonic and embryonic simple epithelia, including trophectoderm, visceral yolk sac, gastrointestinal tract, lungs, mammary glands, and uterus. We report that a targeted null mutation in the mK8 gene causes mid-gestational lethality. Mutant embryos are growth retarded and suffer from internal bleeding, with an abnormal accumulation of erythrocytes in fetal livers. The mK8- phenotype has 94% penetrance, with a few mice surviving into adulthood. We suggest that mK8/mK18 filaments are important for the integrity of the fetal liver, like specialized human epidermal keratins for the integrity of the epidermis. This phenotype in mice differs from the reported function of simple epithelium keratins in Xenopus at the gastrulation stage. In mice, mK8 fulfills a vital function at 12 days postcoitum.
OBJECTIVE: The thyroid gland is physiologically stimulated in normal early pregnancy. However, clinical thyrotoxicosis in normal pregnancy has not been well described. In order to clarify this we examined thyroid function and thyrotoxic symptoms in relation to emesis in normal pregnancy. We also investigated the possible mechanism of gestational thyrotoxicosis. DESIGN: Thyroid function was evaluated in view of the clinical thyrotoxic symptoms and the severity of gestational emesis in early pregnancy of 51 normal women. Two pregnant women who showed clinical thyrotoxicosis were followed serially during and after pregnancy. MEASUREMENTS: Serum free T4, free T3 and TSH were measured by radioimmunoassay and hCG by fluoroimmunoassay. Thyroid-stimulating activity of pregnancy sera was measured by cAMP increase in cultured FRTL-5 cells. RESULTS: Fifty-one pregnant women were divided into three groups: those without emesis (n = 24), with emesis (n = 19) and with hyperemesis (n = 8). Serum free T4 and free T3 were higher in the hyperemesis group (P < 0.01) and the emesis group (P < 0.01), and serum TSH was suppressed to less than 0.1 mU/l in both groups, while serum hCG was not significantly different among these three groups. However, serum thyroid-stimulating activity was remarkably high in the hyperemesis group (P < 0.01). Thus the ratio of thyroid-stimulating activity to hCG was higher in the hyperemesis group (P < 0.05) and the emesis group (P < 0.05) compared with that in the group without emesis. These thyroid-stimulating activities were abolished by treatment of the serum with anti-hCG antibody. Two of eight women with hyperemesis, who had the highest free T4 and thyroid-stimulating activity/hCG ratio, showed overt clinical symptoms of thyrotoxicosis; all the symptoms disappeared in association with a fall in thyroid-stimulating activity and free T4. CONCLUSION: Clinical thyrotoxicosis is caused by circulating hCG with higher biological activity in pregnant women with hyperemesis. A new clinical entity of 'gestational thyrotoxicosis' is proposed and tentative characteristics are discussed.
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MedPics is a computer-based image delivery system with supporting text fields and on-screen graphics to assist in key feature identification. It has been used by the University of California, San Diego as an integral part of the Human Disease course since 1992. Initially created to support pathology and histology, the program has now expanded to include hematology. MedPics has had a positive impact on the second year curriculum for which it was created. Moreover, use of this program has improved student attitudes toward computer-based resources and increased faculty interest in instructional development.
Congenital pituitary hypothyroidism (pituitary cretinism) results in severe mental and growth retardation when it is not treated soon after birth. Since the introduction of neonatal mass screening of thyrotropin (TSH), most congenital hypothyroidism has been detected except for pituitary and hypothalamic hypothyroidism. In 1971, we reported the first familial case of congenital isolated TSH deficiency and thereafter began intensively investigating the molecular pathology of congenital pituitary hypothyroidism. After determining the entire structure of the human TSH beta gene, we identified the molecular pathology in this patient. Recently, we reported a familial case of congenital combined pituitary hormone deficiency (PIT1 abnormality). To examine the PIT1 gene, which encodes pituitary specific transcription factor, Pit-1/GHF-1, we determined its genomic structure. Sequence comparisons using PCR amplified PIT1 gene sequences revealed only one nonsense mutation in the patient, and established that this alteration caused the combined deficiencies of TSH, GH and PRL. We also discuss other recent progress in molecular pathology of congenital pituitary hypothyroidism.
Human cDNA clones encoding Pit-1/GHF-1, a pituitary-specific DNA binding factor, were obtained by PCR following reverse transcription of human pituitary RNA. It is approx. 1.3 kb in size with 0.1 kb 5' non-coding region, 0.9 kb protein-coding region and 0.3 kb 3' non-coding region. The predicted human Pit-1/GHF-1 peptide structure has 291 amino acids and is highly conserved among mouse, rat and bovine. In addition, the 5' non-coding region is highly conserved with rat pit-1/GHF-1 sequence to the transcription start site.
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Experience with young animals, animals administered certain hepatotoxins and animals with two-thirds hepatectomy suggests that tight junctional permeability is increased in states characterized by architectural remodeling in the liver. In this work we correlate changes in tight junctional morphometry induced by two-thirds hepatectomy with changes in biliary permeability assessed by sucrose and horseradish peroxidase permeation and by alterations in biliary outputs of anionic and cationic cholephilic probes. By freeze-fracture examination tight junctional strand counts, density and orientation parallel to canaliculi were all reduced 24 hr after two-thirds hepatectomy. Occasionally, strands were perpendicular to the canaliculi, creating an unobstructed communication between bile and intercellular spaces. These morphological changes correlated with increased sucrose and paracellular horseradish peroxidase access into bile, with reduced biliary outputs of low molecular weight and especially with cationic cholephilic probes. The data support an increased but still charge-selective permeability of the biliary tree, which was induced by two-thirds hepatectomy 24 hr before. Presumably, fixed intercellular connections (tight junctions and gap junctions) must be loosened or lysed to allow the architectural reorganization required by the hepatocellular regenerative process.
Coix seeds, a Chinese medicine have been used in Japan and reported to be effective in patients with verruca vulgaris and verrucae planae juveniles. We investigated the in vivo effects on lymphocyte subsets in seven healthy volunteers who took six tablets of Coix seeds three times a day (a typical dose) for four weeks. Leukocyte counts and the percentage of total lymphocytes did not change but the percentages of CD3+CD56+ cells and CD16+CD57- cells increased significantly. These results indicate that Coix seeds increase peripheral cytotoxic lymphocytes and may be effective to viral infection through the enhancement of cytotoxic activity.