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Biomedical subjects

M Iitaka

Publications and source records attributed to M Iitaka.

At least 37 records · Page 2Linked to original sources
PubMed1998

Elevated serum granulocyte colony-stimulating factor levels in patients with Graves' disease.

OBJECTIVE: Agranulocytosis is a serious side effect of anti-thyroid drugs (ATD). Granulocyte colony-stimulating factor (G-CSF) is one of the cytokines that increase granulocyte number. The aim of this study was to examine the sequential variation of serum G-CSF levels in patients with Graves' disease before and after ATD therapy. PATIENTS: Sixty-three patients with Graves' disease were studied before, during and after treatment with methimazole (MMI). Serum samples from 71 healthy subjects were used as controls. DESIGN AND MEASUREMENTS: Serum levels of G-CSF were measured by a novel chemiluminescent enzyme immunoassay, which was sensitive enough to determine G-CSF levels in healthy subjects. Blood granulocyte counts, serum, thyroid hormone and TSH levels, and titres of thyroid autoantibodies were also measured. RESULTS: Serum G-CSF levels in Graves' patients before and 2 weeks after MMI were significantly higher than in healthy subjects. There was a significant correlation between serum G-CSF levels and granulocyte counts in untreated patients with Graves' disease. Untreated patients with granulocyte counts less than 2 x 10(9)/I had significantly lower serum G-CSF levels as compared with other untreated patients. Serum G-CSF levels gradually decreased thereafter. No correlation was observed between serum G-CSF levels and serum thyroid hormone levels or titres of thyroid autoantibodies. After ATD treatment, no correlation was found between serum G-CSF levels and granulocytes counts. There was no significant correlation between the change of serum G-CSF levels and that of granulocyte counts before and after MMI treatment. Graves' patients with mild agranulocytosis had normal or elevated serum G-CSF levels. CONCLUSIONS: Significantly elevated serum G-CSF levels were observed in patients with Graves' hyperthyroidism. During ATD therapy, deficiency of G-CSF was not identified as a cause of agranulocytosis in this study.

Adult↗
PubMed1998

Retrovirus-mediated suicide gene/prodrug therapy targeting thyroid carcinoma using a thyroid-specific promoter.

To develop gene therapy targeting thyroid carcinoma, the recombinant retrovirus (LNTGTK) carrying herpes simplex virus thymidine kinase (HSV-TK) gene under the control of thyroglobulin (TG) promoter was constructed and its efficacy was investigated in 3 thyroid cell lines; a differentiated normal rat thyroid cell line (FRTL5), malignant rat thyroid carcinoma cells derived from FRTL5 (FRTC) and a human anaplastic thyroid carcinoma cell line (FRO). TG mRNA was detected by Northern blot analysis in FRTL5 cells and by RT-PCR in FRTC cells when cultured with 2 U/L TSH and its expression levels were decreased by TSH withdrawal. However, either methods revealed no TG expression in FRO cells. In vitro cytotoxic assays demonstrated TG expression status-dependent cell killing by transduction of LNTGTK followed by ganciclovir (GCV) treatment. Thus, LNTGTK transduction increased the GCV sensitivity approximately 13,000- and approximately 160-folds in the presence of TSH and approximately 4- and approximately 27-folds in the absence of TSH in FRTL5 and FRTC cells, respectively. In contrast, there was no difference in the GCV cytotoxicity between parental and transduced FRO cells. Significant growth inhibition, but not complete eradication, of transduced FRTC cells was observed in in vivo subcutaneous tumor models of nude mice. These results demonstrate that retrovirus-mediated transduction of HSV-TK gene under the control of the TG promoter confers the GCV sensitivity selectively to TG-expressing thyroid cells. This system may therefore be feasible for gene therapy targeting TG-expressing thyroid carcinomas.

Animals↗
PubMed1998

Increased serum vascular endothelial growth factor levels and intrathyroidal vascular area in patients with Graves' disease and Hashimoto's thyroiditis.

Vascular endothelial growth factor (VEGF) is one of the angiogenic factors. We examined both thyroid volume and intrathyroidal vascular area by color flow Doppler ultrasonography in patients with Graves' disease (GD), Hashimoto's thyroiditis (HT), and subacute thyroiditis. The serum concentrations of thyroid hormones, TSH, TSH receptor antibodies, and VEGF were also examined. There was a significant increase in serum VEGF levels in patients with untreated GD and goitrous HT compared with those in healthy subjects. The serum VEGF levels in untreated patients with subacute thyroiditis were significantly higher than those in patients with untreated GD or HT. There was a significant correlation between serum VEGF levels and the ratio of intrathyroidal vascular area and thyroid area in untreated patients with GD who had a goiter larger than or equal to 40 cm3. There was also a significant correlation between serum VEGF and TSH levels in patients with HT who were hypothyroid and had a goiter. Serum VEGF levels decreased significantly in these patients after treatment; this was accompanied by a significant decrease in intrathyroidal vascular area and thyroid volume. Our study demonstrates that VEGF appears to play an important role in intrathyroidal angiogenesis in patients with GD and goitrous HT.

Adult↗
PubMed1997

Transplantable rat thyroid cancer cell line FRTC transformed with muramyl dipeptide.

A rat thyroid cancer cell line, FRTC, was established from the normal rat thyroid cell line, FRTL-5. FRTL-5 cells were cultured in vitro with N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) for 4 days and were transplanted intraperitoneally into Fisher rats. Disseminated tumour formation in the peritoneum was found in ten out of ten rats in which MDP-treated FRTL-5 cells were transplanted. Colloid-like structures stained with anti-thyroglobulin (Tg) antibodies were observed in the tumours. On the other hand, no tumour was found in any of the rats in which untreated FRTL-5 cells were transplanted. No morphological changes were observed in FRTL-5 cells after long-term in vitro culture in the presence of MDP. MDP had no effect on thymidine incorporation, the production of cAMP or the expression of c-myc in FRTL-5 cells in vitro. Cells from the tumour (FRTC) secreted Tg in vitro and expressed Tg, thyroid peroxidase (TPO) and thyrotropin (TSH) receptor mRNA. The expression of TSH receptor mRNA increased in FRTC cells after TSH stimulation. FRTC cells produced cAMP in response to TSH stimulation in a dose-dependent manner. However, the growth of FRTC cells was TSH independent. Expression of c-myc and c-fos was observed in FRTC cells in vivo as well as in vitro. FRTC cells formed tumours in Fisher rats when transplanted subcutaneously. FRTC cells have several characteristics of differentiated thyroid cancer cells and may provide a good model for the study of human differentiated thyroid cancers.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1996

Thyroid involvement by malignant histiocytosis of Langerhans' cell type.

Involvement of the thyroid gland by Langerhans' cell histiocytosis is quite rare. We describe the case of a 58-year-old man referred for treatment of a progressively enlarging goitre. The trachea was severely stenotic and adjacent structures such as the left carotid vein and the thyroid cartilage were also involved. Central diabetes insipidus and severe combined immunodeficiency were associated. Although fine needle aspiration biopsy of the thyroid was initially interpreted as papillary carcinoma, anaplastic thyroid cancer was suspected. Treatment with prednisolone, doxorubicin and irradiation controlled the tracheal compression. A diagnosis of thyroid Langerhans' cell histiocytosis was finally made on the basis of the presence of Birbeck granules and CD1a and CD4 antigen in the thyroid tumour cells. Furthermore, positive staining for CD68 and lysozyme suggested that the tumour cells may have had the character of phagocytic cells in addition to their dendritic cell nature. This is the first case of thyroid involvement by malignant histiocytosis of Langerhans' cell type with unusual phagocytic markers.

Antigens, CD↗
PubMed1996

Incidence of subacute thyroiditis recurrences after a prolonged latency: 24-year survey.

Subacute thyroiditis, which is considered to be a viral disease, rarely recurs after a complete recovery. We evaluated data on 3,344 patients with subacute thyroiditis who were seen at Ito Hospital between 1970 and 1993. Subacute thyroiditis recurred in 48 of 3,344 patients 14.5 +/- 4.5 yr after the first episode. Five patients experienced a third episode 7.6 +/- 2.4 yr after the second. The mean age of the patients at the first, second, and third episode was 38.4 +/- 6.3, 53.1 +/- 8.9, and 57.8 +/- 10.1 yr old, respectively. The mean incidence of a recurrence was 2.3 +/- 0.9% per year. The erythrocyte sedimentation rate and the duration of treatment were each significantly decreased at the second episode as compared with the first. Thus, recurrences of subacute thyroiditis do occur at least in 2% of patients and exhibited relatively mild clinical manifestations.

Adult↗
PubMed1996

Decrease in serum levels of thyroid hormone in patients with coronary heart disease.

The aim of this study was to evaluate the relationship between subclinical hypothyroidism and/or autoimmune thyroid disease and coronary heart disease (CHD). Ninety seven patients diagnosed as having CHD by a coronary angiography (CHD group) and 103 healthy subjects matched for age, sex and body mass index (control group) were included in the study. Thyroid function, thyroid autoantibodies and serum lipid concentrations were measured in the CHD and control groups. The CHD group exhibited significantly decreased serum free T3 (FT3) and free T4 (FT4) levels, and significantly increased serum TSH levels as compared with the control group, indicating a significant decrease in thyroid function in the CHD patients. Serum high density lipoprotein cholesterol (HDL-C) levels were significantly decreased in the CHD group. The incidence of subclinical hypothyroidism and thyroid autoantibodies was similar in both two groups. These observations were also true of women even after those who had diabetes mellitus (DM), hypertension (HT) and a smoking habit were excluded. This was not the case, however, in men without DM, HT, or a smoking habit. Patients with CHD had significantly lower serum levels of HDL-C than the control subjects, regardless of gender (P < 0.01). In the group with CHD, there was no difference between the serum lipid levels in patients with subclinical hypothyroidism and those with normal thyroid function. Female patients with CHD had significantly lower serum levels of thyroid hormone and HDL-C, but their subclinical hypothyroidism or thyroid autoimmunity did not seem to be related to the development of CHD.

Aged↗
PubMed1994

Involvement of protein kinase A and C in the production of interleukin-1 alpha-induced prostaglandin E2 from mouse osteoblast-like cell line, MC3T3-E1.

Human recombinant interleukin-1 alpha (IL-1) stimulated the mouse osteoblast-like cell line, MC3T3-E1, to produce prostaglandin E2 (PGE2). This was inhibited by 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) in a dose-dependent manner. The protein kinase A (PKA)-specific inhibitor, KT5720, also inhibited the IL-1-induced PGE2 production in MC3T3-E1 cells, as did staurosporine, a potent inhibitor of protein kinase C (PKC). The PKA activator, 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP), weakly stimulated MC3T3-E1 cells to produce PGE2, as did the PKC activator, 12-O-tetradecanoylphorbol 13-acetate (TPA). However, 8-Br-cAMP and TPA acted synergistically to induce PGE2 production equal to that of IL-1. These observations suggest that activation of both PKA and PKC are involved in IL-1-induced PGE2 production in MC3T3-E1 cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1994

Disturbed lipid metabolism in patients with subclinical hypothyroidism: effect of L-thyroxine therapy.

To evaluate whether patients with subclinical hypothyroidism have a disturbance in lipid metabolism, and whether supplemental L-thyroxine (L-T4) therapy would improve their lipid parameters, we measured serum levels of thyroid hormones, TSH and lipid parameters in 34 patients with subclinical hypothyroidism before and 2 months after treatment with L-T4. Before treatment, patients with subclinical hypothyroidism had elevated serum low density lipoprotein cholesterol (LDL-C) concentrations compared with control subjects (P < 0.05). Overall, L-T4 therapy significantly decreased the serum level of TSH (P < 0.01), total cholesterol (TC; P < 0.02), high density lipoprotein cholesterol (P < 0.02), LDL-C (P < 0.05), and the ratio of apolipoprotein B to apolipoprotein A1 (P < 0.05). Lipid values in patients with basal serum TSH levels below 10 mU/l were not affected by L-T4 therapy, whereas serum levels of TC and LDL-C decreases significantly (P < 0.01) in patients with serum TSH levels above 10 mU/l. Thus, the L-T4 treatment appears to have a preventive effect on the disturbance of lipid metabolism in patients with subclinical hypothyroidism, especially in patients with serum TSH levels above 10 mU/l.

Adult↗
PubMed1993

[The effect of arotinolol on the thyroid function and the autonomic nerve systems].

beta-blockers have been accepted as a reasonable adjunct therapy for the treatment of hyperthyroidism. They lessen the sympathetic symptoms such as tachycardia and finger tremor. On the other hand, many studies have demonstrated a decrease in 3, 3', 5-triiodothyronine (T3) during treatment with beta-blockers (especially propranolol). The purpose of this study is to clarify the effect of arotinolol (alpha 1, beta-blocker) on the thyroid functions and autonomic nerve systems (ANS) of patients with Graves' disease. Arotinolol 20mg a day p.o. was given to untreated patients with Graves' disease (n = 16) for 2 weeks. Blood sampling and the ANS function-tests were done before and after the treatment. In addition, the in vitro effects of arotinolol on the cAMP production and the radioactive iodine uptake (RAIU) using rat thyroid cell line FRTL5 were evaluated to examine the direct influence on thyroid cells. Arotinolol improved hyperthyroid symptoms including tachycardia, but had no effect on ANS function-tests. It is of interest that not only T3 but also T4 decreased after the arotinolol treatment. We therefore suspected the direct suppressive effects of arotinolol on the thyroid. There were, however, no in vitro inhibitory effects on the cAMP production and the RAIU in TSH-stimulated FRTL5 cells. The reason why serum T4 levels in patients with untreated Graves' disease have decreased after the treatment of arotinolol could not be clarified. In conclusion, arotinolol is a very useful drug for the initial therapy of patients with Graves' disease to reduce the serum thyroid hormone levels and symptoms of hyperthyroidism when combined with antithyroid drugs.

Adolescent↗
PubMed1993

[Graves' disease].

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Graves Disease↗
PubMed1992

Incidence of anti-mouse IgG in normal subjects and patients with autoimmune thyroid disease.

Serum antibodies to mouse IgG occasionally interfere with two-site immunometric assays in which mouse monoclonal antibodies are used. We examined the titers of antibodies to mouse IgG in serum samples from normal subjects and patients with autoimmune thyroid disease (AITD) using an enzyme-linked immunosorbent assay. Anti-mouse IgG antibodies were positive in 7/119 patients with Graves' disease (5.9%) and 3/60 patients with Hashimoto's thyroiditis (5.0%). One of the 15 patients with a thyroid neoplasm (6.7%) also had antibodies to mouse IgG, as did 5/60 healthy subjects (8.3%). These antibodies were either of the IgG or IgM class. There was no significant difference in the incidence of positive anti-mouse IgG antibody between normal subjects and patients with AITD. It is important to note this high incidence of antibodies to mouse IgG due to the potential of interference with immunometric assays employing mouse monoclonal antibodies.

Antibodies, Anti-Idiotypic↗
PubMed1991

[Studies on thyroid hormone autoantibody (THAA) in 2 cases of Graves' disease with spuriously high free thyroxine values].

Two patients with Graves' disease treated with methimazole (MMI) showed a discrepancy between serum free T4 (FT4) values and other hormone values (especially total T4) which was due to the presence of potent binding activity to labelled T4 analogue (125I-aT4) in their serum. This activity was demonstrated to be in immunoglobulin G (IgG) with kappa light chain isotype in both patients. The binding of 125I-aT4 to their serum was inhibited by unlabelled T4 in a dose-dependent manner. Autoantibodies had almost identical binding affinity to T4 and aT4, although they precipitated more radioactivity when 125I-aT4 was used. The binding of IgG purified from patients' sera to labelled T4 or aT4 was not greater than the corresponding sera, suggesting that the thyroxine binding proteins did not interfere with the assay. Since the specific radioactivity of 125I-aT4 is almost 10 times higher than that of 125I-T4, autoantibodies can precipitate almost 10 times more radioactivity in the FT4 assay than the total T4 assay, thus leading to the spuriously high FT4 values and large discrepancy between FT4 and TT4 values.

Adult↗
PubMed1991

Disturbance of thyroidal iodine metabolism in BB/W rat.

To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8- and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/W rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive iodine incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis.

Animals↗