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Biomedical subjects

K Kuma

Publications and source records attributed to K Kuma.

At least 91 records · Page 5Linked to original sources
PubMed1995

Identification and characterization of a novel protein kinase, TESK1, specifically expressed in testicular germ cells.

We have isolated cDNA clones encoding the rat and human forms of a novel protein kinase, termed TESK1 (testis-specific protein kinase 1). Sequence analysis indicates that rat TESK1 contains 628 amino acid residues, composed of an N-terminal protein kinase consensus sequence followed by a C-terminal proline-rich region. Human TESK1 contains 626 amino acids, sharing 92% amino acid identity with its rat counterpart. The protein kinase domain of TESK1 is structurally similar to those of LIMK (LIM motif-containing protein kinase)-1 and LIMK2, with 49-50% sequence identity. Phylogenetic analysis of the protein kinase domains revealed that TESK1 is most closely related to a LIMK subfamily. Chromosomal localization of human TESK1 gene was assigned to 9p13. Anti-TESK1 antibody raised against the C-terminal peptide of TESK1 recognized two polypeptides of 68 and 80 kDa in cell lysates of COS cells transfected with human TESK1 cDNA expression plasmid. TESK1 protein expressed in COS cells exhibited serine/threonine kinase activity, when myelin basic protein was used as a substrate. Northern blot analysis revealed that TESK1 mRNA was specifically expressed in rat and mouse testicular germ cells. The TESK1 mRNA in the testis was detectable only after the 18th day of postnatal development of mice and was mainly expressed in the round spermatids. These observations suggest that TESK1 has a specific function in spermatogenesis.

Alternative Splicing↗
PubMed1995

A giant nucleopore protein that binds Ran/TC4.

Ran/TC4 is a small nuclear G protein that forms a complex with the chromatin-bound guanine nucleotide release factor RCC1 (ref. 2). Loss of RCC1 causes defects in cell cycle progression, RNA export and nuclear protein import. Some of these can be suppressed by overexpression of Ran/TC4 (ref. 1), suggesting that Ran/TC4 functions downstream of RCC1. We have searched for proteins that bind Ran/TC4 by using a two-hybrid screen, and here we report the identification of RanBP2, a novel protein of 3,224 residues. This giant protein comprises an amino-terminal 700-residue leucine-rich region, four RanBP1-homologous (refs 9, 10) domains, eight zinc-finger motifs similar to those of NUP153 (refs 11, 12), and a carboxy terminus with high homology to cyclophilin. The molecule contains the XFXFG pentapeptide motif characteristic of nuclear pore complex (NPC) proteins, and immunolocalization suggests that RanBP2 is a constituent of the NPC. The fact that NLS-mediated nuclear import can be inhibited by an antibody directed against RanBP2 supports a functional role in protein import through the NPC.

Amino Acid Sequence↗
PubMed1995

Phylogenetic position of Dictyostelium inferred from multiple protein data sets.

The phylogenetic position of Dictyostelium inferred from 18S rRNA data contradicts that from protein data. Protein trees always show the close affinity of Dictyostelium with animals, fungi, and plants, whereas in 18S rRNA trees the branching of Dictyostelium is placed at a position before the massive radiation of protist groups including the divergence of the three kingdoms. To settle this controversial issue and to determine the correct position of Dictyostelium, we inferred the phylogenetic relationship among Dictyostelium and the three kingdoms Animalia, Fungi, and Plantae by a maximum-likelihood method using 19 different protein data sets. It was shown at the significance level of 1 SE that the branching of Dictyostelium antedates the divergence of Animalia and Fungi, and Plantae is an outgroup of the Animalia-Fungi-Dictyostelium clade.

Amino Acid Sequence↗
PubMed1995

Serum-soluble interleukin-2 receptor levels before and after surgical treatment for Graves' disease.

Serum-soluble interleukin-2 receptor (ssIL-2R) is released from its specific affinity membrane receptor on activated T lymphocytes and is detected as a form of the alpha-chain of IL-2R in the peripheral blood. We measured the ssIL-2R levels by enzyme-linked immunosorbent assay in 29 healthy subjects and 39 patients with Graves' disease who were given antithyroid drugs to prepare them for surgical treatment. The preoperative ssIL-2R levels in Graves' patients were significantly higher than those in the healthy controls (681 +/- 387 vs 369 +/- 149 U/ml); in particular, the preoperative levels in hyperthyroid patients were significantly higher than those in euthyroid patients. On the 5th day after thyroid resection, their ssIL-2R levels (560 +/- 296 U/ml) were significantly lower than the preoperative levels. There were no correlations between the preoperative ssIL-2R levels and the immunological parameters such as thyroglobulin antibody, microsomal antibody, and thyroid-stimulating hormone receptor antibody. Thus, we conclude that ssIL-2R levels can be decreased by surgical resection of goiter in Graves' patients whose hyperthyroid status does not respond to the administration of antithyroid drugs, and this may be a useful indicator of immunological status after surgical treatment of Graves' disease.

Adult↗
PubMed1995

Accurate and simple method of diagnosing thyroid nodules the modified technique of ultrasound-guided fine needle aspiration biopsy.

We describe an accurate and simple method of diagnosing thyroid nodules by the modified technique of ultrasound-guided fine needle aspiration biopsy (UG-FNAB). An Aloka SSD 2000 focus type scanner (Aloka Co., Tokyo, Japan) equipped with a 10-MHz mechanical sector probe and a 7.5-MHz convex probe was used. First, a clear picture of the thyroid gland was taken with the use of the 10-MHz probe to determine the abnormalities. Then, a 7.5-MHz probe (1.5 x 0.8 cm of surface area) was used to guide the needle perpendicularly to the neck. This method enabled us to obtain samples from nodules greater than 5 mm. We applied this technique to 1000 patients who had uncertain diagnosis by the conventional method of FNAB. The advantages of this method are as follows: (i) The use of a small probe (7.5 MHz) is most important, since a needle can be inserted by watching the monitor without an assistant. (ii) The biopsy site can be chosen precisely. (iii) Small thyroid cancers, i.e., 5 mm cancer, can be biopsied without any difficulty. (iv) A life-threatening anaplastic carcinoma can be diagnosed at an early stage. (v) An intraglandular metastasis to the opposite lobe can be detected. (vi) Cystic carcinoma, difficult to diagnose by FNAB, can be diagnosed accurately. This method is highly recommended for all clinicians who are currently doing FNAB.

Biopsy, Needle↗
PubMed1995

Functional constraints against variations on molecules from the tissue level: slowly evolving brain-specific genes demonstrated by protein kinase and immunoglobulin supergene families.

In the protein kinase family, the basic function of kinase domain is similar among members. According to the standard view of functional constraint, the molecular evolutionary rate depends on functional and structural features characteristic of individual molecules (local constraint). Thus the evolutionary rate of the kinase domain is expected to be similar for different members. Contrary to this expectation, a comparison of the evolutionary rates revealed a wide difference among members; it amounts to about 100 times difference between the maximum and minimum rates. A similar result was also found in members of the immunoglobulin (Ig) family. In addition, significant correlations in evolutionary rate were observed between the kinase domain and the Ig-like domain in the receptor protein tyrosine kinases and between the kinase domain and the SH domain in the nonreceptor-type kinases. Furthermore, the evolutionary rates of family members that are expressed tissue specifically differ widely, depending on their tissue distribution: members expressed in the brain evolve with significantly slower rates than those expressed in the immune system. These results strongly suggest the presence of an alternative constraint (global constraint) against changes on molecules derived from higher levels like tissues or organs.

Animals↗
PubMed1995

A study of untreated Graves' patients with undetectable TSH binding inhibitor immunoglobulins and the effect of anti-thyroid drugs.

OBJECTIVE: We previously reported the clinical characteristics of Graves' disease with undetectable TSH binding inhibitor immunoglobulins (TBII) at first visit, but a study of the prognosis of untreated TBII negative patients with anti-thyroid drug medication has never been undertaken. The aim of this paper is to study the difference between negative and positive TBII Graves' disease in relation to the effect of anti-thyroid drug treatment. PATIENTS: From January 1986 to April 1991, 1545 patients with untreated Graves' disease were referred to Kuma Hospital, Kobe, Japan. Of these, 94 TRAb negative patients were identified. Another 83 TRAb positive patients were randomly selected from the other Graves' disease patients and served as a comparison group. Fifty-six of the 94 patients in the TBII negative group and 52 of the 83 patients in the TBII positive group completed treatment with methimazole only. MEASUREMENTS: The trial was conducted as a retrospective study with a maximum treatment period of 36 months and a follow-up period of a further 12 months. From the original pool of patients, we classified 56 TBII negative patients into two groups according to the clinical course taken; Group A in whom TBII remained undetectable throughout methimazole treatment (9 men and 34 women, age 37.2 +/- 2.2 years), and Group B who became TBII positive (4 men and 9 women, 31.2 +/- 4.4 years). Fifty-two TBII positive patients served as the comparison Group C (8 men and 44 women, age 38.1 +/- 2.0 years). RESULTS: Serum free T4 and free T3 levels in groups A and B were significantly lower before treatment than those of Group C (P < 0.001). The thyroid volumes of Group A and B patients were significantly smaller than those of Group C (P < 0.01). The level of TBII in Groups A and B was significantly lower than that in Group C (8.3 +/- 0.7 and 8.8 +/- 1.1 vs 57.0 +/- 2.8%, respectively, P < 0.001). The level of thyroid stimulating antibody (TSAb) in Groups A and B was significantly lower than that in Group C (478 +/- 71.0 and 761 +/- 140.3 vs 2143 +/- 280%, respectively, P < 0.01), and there were no significant differences in TSAb activities between Groups A and B. The remission rates in Groups A, B and C were 77.4, 36.4 and 36.5%, respectively. These data indicate that Group A has a good prognosis, but Group B has the same prognosis as Group C. CONCLUSION: We conclude that patients in whom TSH binding inhibitor immunoglobulins remained negative have a much better prognosis than TSH binding inhibitor immunoglobulins positive patients or those who become TSH binding inhibitor immunoglobulins positive, having been initially negative.

Adult↗
PubMed1995

Quantitative analysis of stromal fat content of human parathyroid glands associated with thyroid diseases using computer image analysis.

The stromal fat content in the parathyroid glands and its significance are still controversial. Several methods have also been introduced to evaluate the content in the literature. In an attempt to better understand the significance of stromal fat content, a computer image analyzing system was applied and 62 glands were investigated using routinely processed tissue. Our study revealed that the average stromal fat content was 34.8 +/- 18.7% which was lower than that of other studies. The stromal fat content was correlated with the age, grade of obesity, area of the gland and serum parathormone level; however, no consistent patterns were obtained with other clinical parameters. These results indicate that the change of stromal fat content may be related to the general condition of the patient similar to the change of fat in other organs. However, the decrease of the content may indicate the early change of parathormone secretory activity even if the serum examination shows no evidence of hyperfunction of the glands.

Adipose Tissue↗
PubMed1995

The correlation between papillary thyroid carcinoma and lymphocytic infiltration in the thyroid gland.

Ninety-five patients with papillary thyroid carcinoma (PTC) who received primary surgical treatment in 1983 at Kuma Hospital and were followed until 1992 were the subjects of this study. Initial therapy was tumor resection for 5 patients, lobectomy for 23 patients, total thyroidectomy with unilateral modified neck dissection for 60 patients, and total thyroidectomy with bilateral modified neck dissection for 7 patients. Clinical stage at diagnosis was as follows. Class I included 28 patients with intrathyroidal disease, class II included 60 patients with positive cervical lymph nodes, and class II included 7 patients with tumor invasion into tissue outside of the thyroid gland. Recurrence of the tumor was evaluated according to lymphocytic infiltration in the thyroid gland. Group A consisted of 36 patients with PTC associated with lymphocytic infiltration, 26 with infiltration surrounding the tumor, 3 with infiltration inside of the tumor, and 7 with both. Group B consisted of the remaining 59 patients with PTC with no lymphocytic infiltration. There were no differences in age, sex, initial tumor size, or initial treatment between groups A and B. Antithyroglobulin antibody and/or antimicrosomal antibody were positive in 16 patients from group A and 4 patients from group B (P < 0.001). Class I included 14 patients from each group, class II included 22 patients from group A and 38 patients from group B, and class III included 7 patients, all from group B. Recurrence of the tumor was found in only 1 group A patient (2.8%), but in 11 patients of group B (18.6%). The percentage of patients free from recurrence over the 10 yr of follow-up in group A was significantly higher than that in group B (by Cox-Mantel test, P < 0.01). The time between initial treatment and recurrence was 2-10 yr. In comparing the clinical stage at the time of initial treatment, recurrence was found in 1 class II patient from group A (4.5%) and in 1 class I (7.1%), 6 class II (15.8%), and 4 class III (57.1%) patients from group B. No patients died during the 10 yr of follow-up. In conclusion, 1) lymphocytic infiltration surrounding the tumor or inside the tumor in PTC might be of use as a means for predicting a favorable prognosis; and 2) class II or class III patients with no lymphocytic infiltration had a high rate of recurrence.

Adult↗
PubMed1995

Clinical characteristics of subacute thyroiditis classified according to human leukocyte antigen typing.

We investigated human leukocyte antigen (HLA) class I and class II antigens in 56 Japanese patients with subacute thyroiditis (SAT) who visited our out-patient clinic between 1988 and 1990. We found SAT to be associated with not only HLA-B35 (40 patients; P < 0.000001; relative risk, 18.02), but also with HLA-B67 antigens (9 patients; P < 0.00001; relative risk, 11.20). No heterozygotes of HLA-B35 or HLA-B67 were found in any of the 56 patients with SAT. Either HLA-B35 or HLA-B67 antigen is found in 87% of patients with SAT. When season of onset and clinical course of SAT were compared in the 49 patients with HLA-B35-positive SAT (B35-SAT) and HLA-B67-positive SAT (B67-SAT), we were able to identify certain characteristics: 1) B67-SAT often followed the course from transient thyrotoxicosis to a hypothyroid phase to a euthyroid phase [6 of 9 B67-SAT (67%) vs. 10 of 40 B35-SAT (25%); P < 0.05]; and 2) B67-SAT occurred mostly during the summer or autumn and at a higher rate than did B35-SAR [8 of 9 B67-SAT (89%) vs. 17 of 40 B35-SAT (43%)], whereas B35-SAT occurred throughout the year. We conclude that there are at least two types of SAT that can be classified by association with either HLA-B35 or HLA-B67 antigens.

Acute Disease↗
PubMed1995

Lack of effect of thyroxine administration on elevated thyroid stimulating hormone receptor antibody levels in treated Graves' disease patients.

Increased levels of antibodies to TSH receptors are thought to be a major cause of active Graves' disease or recurrence following therapy. It was recently reported that T4 administration during antithyroid drug treatment for Graves' disease resulted in a significant decrease of TSH receptor antibodies compared to drug therapy alone. It is known that these antibodies may remain elevated long after patients become euthyroid, so a large number of patients whose antibodies remained significantly elevated after 1 year of methimazole therapy were evaluated in the study. A total of 330 Graves' disease patients were treated with methimazole for 1 year. TSH receptor antibody titers remained persistently elevated in 195 patients. Thirty-five randomly selected patients were continued on maintenance doses of methimazole for a second year, and 160 patients were treated with a combination of methimazole and thyroxine for a second year. T4 doses needed ranged from 75-100 micrograms/day to maintain serum-free T4 and free T3 within the normal range. After 6 months of combined therapy, 35 patients were found to have suppressed serum TSH levels. The patients were divided after 18 months into three groups: A, B, and C. Group C, consisting of 35 randomly selected patients (8 males and 27 females) whose ages ranged from 12-62 years and who had been maintained on methimazole alone, served as controls. Group B, whose serum TSH levels were suppressed after 6 months of combined therapy, consisted of 9 males and 26 females whose ages were 15-66 years. Group A, 35 randomly selected patients with normal serum TSH levels after methimazole and thyroxine therapy for 6 months, consisted of 8 males and 27 females whose ages were 10-63 years. TSH receptor antibody titers gradually decreased in all three groups with drug therapy, and there was no significant difference in the titers at corresponding times, i.e. 0, 1.0, 1.5, and 2.0 years. After treatment for 2.0 years, all patients of the three groups were followed for a further 12 months. Rates of recurrence among the above three groups were not significantly different during the observation period. In the present study, T4 administration in combination with antithyroidal drugs had no effect on levels of antibodies to TSH receptors and no effect on rates of recurrence. The reason for the discrepant results in the present study from previous reports is not known.

Adolescent↗
PubMed1995

Rarity of oncogenic mutations in the thyrotropin receptor of autonomously functioning thyroid nodules in Japan.

Constitutively activating mutations have recently been identified in the thyrotropin receptor (TSHR) of hyperfunctioning thyroid adenomas and familial hyperthyroidism. In the present study, we evaluated the frequency of constitutively activating TSHR mutations in a large series of autonomously functioning thyroid nodules (AFTNs) in Japan. Forty-five AFTNs (38 solitary hyperfunctioning thyroid adenomas and 7 toxic multinodular goiters) were analyzed. Genomic DNA was extracted from paraffin-embedded tissue sections, from which DNA fragments encoding the mutational hot spots of the receptor (the third cytoplasmic loop and the sixth transmembrane segment) were amplified by polymerase chain reaction. In the single-stranded conformation polymorphism (SSCP) analysis, only one hyperfunctioning adenoma (no. 21) displayed a migration abnormality. In sequence analysis, an unusual mutation of alternate three-base deletions at nucleotides 1953-1957 (AAA GAT ACC to AAG TCC), resulting in one amino acid deletion (Asp at 619) and one conservative amino acid substitution (Thr to Ser at 620), was identified in tumor DNA but not in leukocyte DNA of no. 21. Further, the normal sequence in these regions was confirmed in 10 randomly selected samples with normal migrating patterns in SSCP analysis. The functional property of the mutant with delta 619 and T620S (designated TSHR delta 619) was then evaluated with in vitro mutagenesis and transfection studies. Unexpectedly, however, there were no significant differences in TSH binding affinity, and basal and TSH-stimulated levels of cAMP and inositol 1,4,5-triphosphate between the TSHR delta 619 and the wt-TSHR. In conclusion, the incidence of the constitutively activating TSHR mutations in AFTNs appears to be low in Japan. The oncogenic potential of a novel somatic mutant TSHR delta 619 identified in a hyperfunctioning adenoma in this study is at present uncertain because of its intact function.

Base Sequence↗
PubMed1995

Molecular clock for dating of divergence between animal phyla.

To estimate approximate times of divergence of animal phyla lacking fossil data, it is important to find a molecule that evolves with an approximately constant rate over a wide evolutionary distance covering the whole animal phyla. For this purpose, the evolutionary rate constancy has been examined for 20 proteins. It was found that four proteins, particularly the aldolase C, involved in the glycolitic pathway, had evolved with rates that are approximately constant not only among different classes of vertebrates, but also between vertebrates and arthropods. The evolutionary rate (= 0.26 x 10(-9)/site/year) of the aldolase C is likely to have remained essentially unchanged even between animals and plants.

Animals↗
PubMed1995

Serum concentrations of granulocyte colony-stimulating factor (G-CSF) determined by a highly-sensitive chemiluminescent immunoassay during the clinical course of subacute thyroiditis.

Granulocyte colony-stimulating factor (G-CSF) concentrations in serum were determined for the first time by a newly developed and highly sensitive chemiluminescent immunoassay (the limitation of detection, 0.5 pg/ml) in ten patients with subacute thyroiditis, during treatment with glucocorticoid or indomethacin. Before therapy, circulating neurophil counts significantly increased to 5.15 +/- 2.07 x 10(3)/microliters compared with the convalescent phase (2.94 +/- 1.07 x 10(3)/microliters), and the data were correlated with individual serum G-CSF levels (r = 0.854, P < 0.01). Serum concentrations of interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were less than the detectable threshold of ELISA. During two weeks of glucocorticoid therapy, although the circulating neutrophil counts increased from 5.15 +/- 2.46 x 10(3)/microliters to 7.73 +/- 1.64 x 10(3)/microliters (P < 0.01), serum G-CSF levels were depressed from 25.1 +/- 15.3 pg/ml to 13.8 +/- 13.9 pg/ml (P < 0.01). These data indicate that G-CSF is one of the mediators of the increase of neutrophils in subacute thyroiditis, while it does not contribute to steroid-induced neutrophilia.

Adult↗
PubMed1995

Sporadic activation of Epstein-Barr virus in thyroid lymphoma.

The causal role of Epstein-Barr virus (EBV) in the development of B-cell lymphoma, especially in immunocompromised individuals, has been suggested. The purpose of the present study was to evaluate an association of EBV with thyroid lymphoma (TL) and chronic lymphocytic thyroiditis (CLTH) which is known to play an important role in the development of TL. Thirty cases with TL and 28 with CLTH were studied for presence or absence of EBV genome in the lesions using the polymerase chain reaction (PCR) and the in situ hybridization method. EBV genomes were detected by PCR in one and two cases with CLTH and TL, respectively. Subtyping of EBV genome was possible in one TL case showing B-type in EBNA-2 coding region. In situ hybridization revealed positive signals in the nucleus of lymphoma cells, which also expressed latent membrane protein-1. The present findings indicate that activation of EBV in TL is not common.

Adolescent↗
PubMed1994

Horseshoe crab (1,3)-beta-D-glucan-sensitive coagulation factor G. A serine protease zymogen heterodimer with similarities to beta-glucan-binding proteins.

Horseshoe crab factor G is an intracellular serine protease zymogen that initiates the (1,3)-beta-D-glucan-sensitive hemolymph clotting pathway. Unlike other known serine protease zymogens, which are composed of a single subunit, factor G consists of two distinct subunits, alpha and beta, which are autocatalytically converted to active factor G in the presence of (1,3)-beta-D-glucan. We have now cloned and sequenced cDNAs encoding both subunits of factor G. The subunits are derived from separate mRNA species and thus encoded by different genes. Subunit beta is a serine protease zymogen which consists of 278 residues with a calculated molecular mass of 30,846 Da; it exhibits homology to the serine protease domain of horseshoe crab factor B. Subunit alpha, on the other hand, is a new type of mosaic protein with intriguing features. The mature protein consists of 654 residues with a calculated molecular mass of 73,916 Da. The NH2-terminal portion of this subunit is similar to bacterial beta-1,3-glucanases. Its 126 amino acid COOH terminus exhibits a repetitive sequence having partial homology to xylanases. Between these regions are three repeating units of 47 amino acids, whose similarity to carbohydrate-binding proteins suggests that these may be the (1,3)-beta-D-glucan-binding domain(s) of factor G. Factor G, thus, is a structurally unique heterodimeric serine protease zymogen and as such may represent a new class of active defense proteins.

Amino Acid Sequence↗
PubMed1994

Absence of p53 mutation in Japanese patients with malignant thyroid lymphoma.

Abnormalities of the gene encoding the sequence-specific DNA-binding protein, nuclear phosphorprotein p53, are among the most common genetic alterations observed in human cancers. A mutation of this tumor suppressor gene has been reported with a low prevalence in differentiated thyroid carcinomas, while the prevalence was high in undifferentiated thyroid carcinomas. We used denaturing gradient gel electrophoresis (DGGE) to probe for mutations of p53 gene in order to determine its role in the genesis of malignant thyroid lymphoma. Involvement of 27 samples had been proven by histopathologic examination of specimen obtained by open biopsy of the thyroid gland or from cervical lymph nodes. DNA was extracted from tissues embedded in paraffin blocks and exons 5-8 of p53 gene were examined for the presence of mutations by DGGE following amplification by PCR using GC-clamped primers. To confirm accuracy of the method, samples with known p53 mutations were included in the study. No mutations were detected in any of the amplified exons of malignant thyroid lymphoma samples. These results suggest that p53 mutations are not present or are uncommon in Japanese patients with malignant thyroid lymphomas. The role of p53 in this form of carcinogenesis cannot be fully excluded since we have not examined the occurrence of mutations in regions upstream of exon 5.

Aged↗