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Biomedical subjects

H Fukazawa

Publications and source records attributed to H Fukazawa.

At least 73 records · Page 4Linked to original sources
PubMed1994

Effects of thyroid hormone on carbonic anhydrase I levels in human erythroid (YN-1) cells.

We recently have reported that patients with hyperthyroidism have red blood cell carbonic anhydrase I (CAI) levels that reflect the patient's integrated thyroid hormone level over the preceding few months. In the present study, the effect of T3 on CAI concentrations in the human erythroleukemic cell line, YN-1, was studied. The presence of high affinity (1.9 x 10(9) L/mol), low capacity (20.4 fmol/10(6) cells) T3 binding sites was demonstrated in YN-1 cell nuclei. T3 at a physiological free T3 concentration (0.54 nmol/L) significantly (32 +/- 7%, P < 0.01) decreased CAI concentrations in YN-1 cells before induction of differentiation. The effect of T3 on CAI levels was more obvious (42 +/- 7%, P < 0.01) in the presence of transforming growth factor-beta 1 (TGF-beta 1), which induces hemoglobin synthesis and differentiation in YN-1 cells. These results suggest that the YN-1 cell line may be used to study T3 action on human red blood cell CAI.

Carbonic Anhydrases↗
PubMed1994

Studies on active substances in herbs used for hair treatment. I. Effects of herb extracts on hair growth and isolation of an active substance from Polyporus umbellatus F.

The effects of methanol extracts of 80 herbs on hair growth were investigated, using normal C3H/He mice from which telogen hair on the back had been removed. Eighteen of the extracts apparently promoted hair regrowth on the mice. As one of active principles in Polyporus umbellatus F., 3,4-dihydroxybenzaldehyde was isolated by column chromatography on Amberlite XAD-2, Sephadex LH-20 and silica gel.

Animals↗
PubMed1994

[Comparative analysis of living conditions of elderly diabetic patients in rural areas].

The present study was performed to examine living conditions of elderly diabetic patients in rural areas in Iwate and Miyagi in northern Honsyu and compared them with similar cases in Tokyo. One hundred and nine cases over 60 years old were interviewed, and results were compared to 109 age- and sex-matched random samples in the Tokyo area. The original Tokyo subjects consisted of 383 outpatients of the Diabetic Clinic of Tokyo Metropolitan Geriatric Hospital. Types of family structure, educational background and total income were quite different in the 3 areas, and patterns of social support depended on area-specific characteristics. Attitudes toward diabetic treatment (acceptance of importance and compliance) in Tokyo were excellent, but the sensation of social burden and dissatisfaction were also at a high level. In contrast, the level of compliance in Iwate was low. Total morale scale scores were similar in the 3 areas. Multivariate analysis (dependent variable is the total morale score) showed significant contribution of levels of ADL and adherent behavioral style only in Tokyo. In contrast, the feeling of social burden was a negative factor in all areas. The quality of life of elderly people with chronic diseases such as diabetes, is affected by ability to adaptation to living conditions.

Activities of Daily Living↗
PubMed1993

Method for simultaneous detection of protein kinase A, protein kinase C, protein tyrosine kinase, and calmodulin-dependent protein kinase activities.

We report a simple method that permits simultaneous detection of multiple protein kinase activities using postnuclear supernatant of v-src transformed NIH3T3 cells. A supernatant is incubated with activators of protein kinases and [gamma-32P]ATP, and the phosphorylated proteins are analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The method enables detection of activities of at least four protein kinases (protein kinase A, protein kinase C, protein tyrosine kinase(s), and calmodulin-dependent protein kinase III) on a single gel. Experiments using various specific activators and inhibitors of protein kinases indicated that this method can, in crude preparations, reliably detect the protein kinase activities intended for measurement. Protein kinase C activity disappeared when membranes were solubilized, demonstrating the importance of membrane environment for its function. This method should be particularly useful for evaluating and screening protein kinase inhibitors.

3T3 Cells↗
PubMed1993

Expression of the Hermes-1 (CD44) and ICAM-1 (CD54) molecule on the surface of thyroid cells from patients with Graves' disease.

From studies of binding of 51Cr-labeled T cells to human thyroid monolayers, we have postulated the existence of tissue "homing-like" receptors on thyroid cells in patients with Graves' disease (GD). In this study we have investigated whether the CD44 (Hermes-1) protein, well known as a putative human lymphocyte homing receptor, is expressed on thyroid cells in patients with GD, and if so whether its expression is influenced by interferon-gamma (IFN-gamma). Cell surface CD44, as well as CD54 (ICAM-1), another putative homing receptor, antigens were analyzed by flow cytometry and immunohistochemistry. CD44 and CD54 were both expressed on thyroid cells from untreated patients with GD, which, in the case of CD44, appeared as two peaks. IFN-gamma treatment enhanced the expression of the CD54 protein on Graves' thyroid cells and inhibited the expression of the larger of the two CD44 peaks, but not the other. Only small amounts of CD44 and CD54 were detected on normal thyroid cells, neither of which was affected by IFN-gamma. The CD44 protein was also demonstrated on both GD and normal thyroid cells by immunohistochemistry. These findings suggest that CD44, and possibly CD54, may induce putative adhesion pathways that lead to the homing of lymphocytes to the thyroid in patients who develop Hashimoto's thyroiditis and Graves' disease.

Adult↗
PubMed1993

Thyroxine 5-deiodinase in human brain tumors.

To determine whether human brains contain deiodinating pathways, we studied the activity of T4 5-monodeiodinase (5-D) in 20 human brain tumors obtained intraoperatively, including astrocytoma (10), meningioma (4), oligodendroglioma (2), glioblastoma (2), medulloblastoma (1), and malignant lymphoma (1). Mitochondrial-microsomal fractions prepared from these tumor tissues were used as the source of T4 5-D. Each sample was incubated with 32.2 nmol/L T4 and 30 mmol/L dithiothreitol at 37 C for 90 min. T4 5-D activity was measured by the production of rT3 from T4 with a RIA. T4 5-D activity was found in 6 of 10 astrocytomas, 2 oligodendrogliomas, 1 of 2 glioblastomas, and 1 malignant lymphoma. This activity depended on protein concentration, incubation time, incubation temperature, and pH of the incubation mixture. It was also heat labile. T4 5-D was not inhibited by 1 mmol/L propylthiouracil, but was inhibited by iopanoic acid and aurothioglucose in a dose-dependent manner. The apparent Km and maximum velocity for T4 5-D at 30 mmol/L dithiothreitol were 106.6 nmol/L and 22.7 pmol/mg protein.h, respectively. These data suggest that human gliomas (and probably malignant lymphomas) contain T4 5-D activity, which is similar to type III enzyme activity in the rat. T4 5-D may regulate the intracellular concentration of thyroid hormone in gliomas.

Adult↗
PubMed1993

Inhibition of placental thyroxine 5-deiodinase activity decreases amniotic fluid concentration of 3,3',5'-triiodothyronine in rat.

We investigated whether the inhibition of placental T4 5-deiodinase (5-D) activity would decrease the amniotic fluid (AF) concentration of rT3. Iopanoic acid (IOP) was used to inhibit placental T4 5-D activity. From gestation days 14 to 17, a group of rats received IOP (10 mg/100 g bw/day, sc) once daily in experiment (exp) 1, and received it (40 mg/100 g bw/day) four times daily in exp 2. In exp 2, control dams received propylthiouracil (PTU; 2 mg/100 g bw/day) instead of IOP. Methimazole and T4 were also given to all dams in exp 1 and 2. On day 17 of gestation, we collected the liver, placenta, blood, and AF of each animal. In the IOP-treated group in both experiments, the serum T4 concentration was significantly increased. Hepatic T4 5'-deiodinase activity was significantly decreased by either PTU or IOP administration. In both experiments placental T4 5-D activity was significantly decreased in the IOP-treated group. The concentration of rT3 in AF was significantly decreased in the IOP-treated group in exp 2 (1.71 vs. 0.75 nmol/l, P < 0.01) despite a higher serum T4 concentration. There was a significant positive correlation between placental T4 5-D activity and the concentration of rT3 in AF in exp 2 (r = 0.62, P < 0.05). These observations indicate that the inhibition of placental T4 5-D activity decreases the concentration of rT3 in rat AF, and that placental T4 5-D and the T4 concentration in maternal serum plays important roles in maintaining the concentration of rT3 in rat AF.

Amniotic Fluid↗
PubMed1993

Pasteurella ureae endocarditis.

Pasteurella ureae is found in the normal human respiratory flora. We encountered a case of endocarditis caused by Pasteurella ureae. The patient was a 59-year-old man with a history of Staphylococcus aureus endocarditis. After treatment with antibiotics, blood cultures became negative, and the patient recovered completely. The incidence of endocarditis due to this organism is very rare; this case is the second clinically diagnosed case report.

Anti-Bacterial Agents↗
PubMed1993

[An experimental study of catheter ablation using microwave energy via coaxial electrode catheter].

The purpose of this study was to examine the efficacy, arrhythmogenicity, and the size of ablated lesions of catheter ablation with microwave energy. Microwave energy generated by a device with a frequency of 2450 MHz, was delivered via a bipolar electrode coaxial catheter with an electrode ball tip. Microwave ablation was applied (50 watts for 15-150 sec.) on the left ventricular endocardium in 6 dogs. No ventricular arrhythmia occurred during ablation in any of the dogs when microwave catheter ablation was applied for less than 45 sec. However, when the duration of microwave catheter ablation was longer than 45-60 sec, ventricular premature contractions were observed in all 6 dogs. When ablation time was set for a longer time, the dogs developed nonsustained ventricular tachycardias. Nevertheless, ventricular arrhythmias after ablation did not occur in all dogs. Ventricular programmed stimulation after ablation did not induce ventricular tachycardia in any of the dogs. When ablation time lasted more than 120 sec, the coagulation layer was extended to the epicardium in all 6 dogs. The results of this study suggest that microwave ablation is feasible for the treatment of tachyarrhythmias from a deep focus of the ventricular myocardium.

Animals↗
PubMed1993

Biochemical consequences of biotin deficiency in osteogenic disorder shionogi rats.

The biological consequences of biotin deficiency in rats were investigated using osteogenic disorder Shionogi rats which have a hereditary defect in ascorbic acid synthesizing ability. Decrease of liver ascorbic acid content and fasting plasma glucose and an increase of plasma non-esterified fatty acid (NEFA) appeared in biotin deficient rats fed a diet containing 200 mg ascorbic acid per 100 g diet, compared with the pair fed control. On the other hand, in the case of rats fed a diet containing 500 mg ascorbic acid, although the clinical features of biotin deficiency developed, the ascorbic acid contents of liver and adrenal gland increased in comparison with those of AsA 200 mg groups, and the alterations of plasma levels of glucose and NEFA were improved partially in glucose and greatly in NEFA, respectively. This suggests that ascorbic acid may be consumed in the improvement of the metabolic impairments induced by biotin deficiency.

Animals↗
PubMed1993

Method of identifying inhibitors of oncogenic transformation: selective inhibition of cell growth in serum-free medium.

We developed a new method for evaluating inhibitors of oncogenic signal transduction pathways based on different growth abilities between normal and transformed cells in a defined serum-free medium. The growth rates of src, abl or ras oncogene-transformed cells, activated raf proto-oncogene transformed cells, and normal NIH-3T3 cells were 60-90%, 20-30% and 10% in a serum-free medium, respectively, compared to the growth rates in a serum-containing medium. An addition of a growth factor (PDGF, FGF or TGF-beta) stimulated the growth of normal NIH3T3 cells by 40-80% in a serum-free medium. Herbimycin A, a specific cytoplasmic protein tyrosine kinase inhibitor, selectively inhibited the growth of src or abl transformed cells in the serum-free medium resulting in about 10-fold or fivefold lower IC50 than those in the serum-containing medium. The antibiotic did not show such an effect on ras transformed cells, and the treatment of src transformed cells with other protein kinase inhibitors or cytotoxic drugs showed little IC50 shifts between the two media. Thus, this method of comparing growth inhibition in the serum-free and the serum-containing media may be useful in evaluating specific inhibitors of signaling pathways mediated by growth factors and certain oncogene products.

3T3 Cells↗
PubMed1992

Tyrosine protein kinase is involved in anti-IgM-mediated signaling in BAL17 B lymphoma cells.

BAL17 B lymphoma cells, representing mature B lymphocytes, were used to analyze the role of tyrosine kinase in B cell activation. Anti-IgM-induced tyrosine phosphorylation was inhibited by preincubation of cells with tyrosine kinase inhibitor herbimycin A. Enzymatic activity of lyn protein was also inhibited by this drug, accompanied by down-regulation of p53lyn and p56lyn. However, a protein kinase C-mediated event was intact in the herbimycin A-pretreated cells, suggesting that the inhibitor acts selectively on tyrosine kinase. Anti-IgM failed to stimulate herbimycin A-pretreated cells to induce increases in inositol phospholipid metabolism or increased [Ca2+]i, whereas aluminum fluoride-induced metabolism was not altered. Moreover, membrane IgM density as revealed by flow cytometry was not changed by herbimycin A. These results indicate that tyrosine kinase(s) participates in the coupling of an Ag receptor cross-linkage to phospholipase C activation through a phosphorylation event in B lymphoma cells.

Animals↗
PubMed1992

Reversion of thyrotoxic atrial fibrillation in hypothyroid state after radioiodine treatment.

Twenty patients with thyrotoxic Basedow's disease complicated by atrial fibrillation lasting more than one month despite treatment with antithyroidal drugs were treated with radioiodine supplemented with an antithyroidal drug or inorganic iodine. We classified the 20 patients on the basis of atrial fibrillation reversion into two groups, one with reversion (group I) and the other without reversion (group II). In all 12 patients in group I, T4 and T3 decreased to hypothyroid levels in 3.2 +/- 1.3 months, and one month later all patients had their sinus rhythm restored while T4 and T3 remained below normal (2.6 +/- 1.1 micrograms/dl and 77.9 +/- 34.4 ng/dl, respectively). Although T4 and T3 also decreased within 3.5 +/- 1.8 months in all 8 patients in group II, one month later, atrial fibrillation persisted while T4 and T3 (10.4 +/- 5.3 micrograms/dl and 157.7 +/- 67.5 ng/dl, respectively) rose significantly compared to those in group I (P less than 0.001 and P less than 0.01, respectively). For reversion of atrial fibrillation it is important that the onset of hypothyroidism is rapidly induced by radioiodine and that hypothyroidism continues for at least one month.

Adult↗
PubMed1992

Tissue specific binding of lymphocytes to the thyroid gland of BB/W rats may be an early event in the development of thyroiditis.

Thyroiditis occurs in about 50% of diabetic Bio Breeding/Worcester (BB/W) rats. In order to investigate the earliest stages of lymphocyte homing to the thyroid gland in the development of experimental autoimmune thyroiditis, we measured the amount of trapping of peripheral blood lymphocytes (PBL) from BB/W rats to the thyroid gland of syngeneic recipient animals. PBL, from donor normal or diabetic BB/W rats, labelled with 51Cr, were injected, i.v., into normal, "potentially diabetic" or diabetic BB/W recipients. After 24 hr the rats were sacrificed and the radioactivity of selected individual organs counted. Results were calculated as % binding of 51Cr-labelled PBL/unit weight of tissue and expressed as a binding index by comparing to binding to recipient blood lymphocytes. A significant binding index was taken as greater than 1.0. PBL from diabetic or normal donor BB/W rats were shown to bind significantly to the thyroid gland of 8 out of 19 "potentially diabetic" or diabetic recipient syngeneic rats, but to none of the normal (non diabetic) recipients tested. Sixty percent of "potentially diabetic" BB/W rats and 50% of diabetic rats at 3-4 months of age showed a significant level of binding of donor lymphocytes from syngeneic diabetic or normal animals to their thyroid gland, while, at 5-6 months the proportion of recipient rats giving positive tests was much less (17%). The source of the donor lymphocytes (diabetic, or normal) did not significantly influence the binding. Lymphocyte binding to pancreas was not significantly greater than to control tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Significance of anti-eye muscle antibody in patients with thyroid-associated ophthalmopathy by quantitative western blot.

To investigate the prevalence of antibody against rat eye muscle membrane antigen, as determined from SDS-polyacrylamide gel electrophoresis and western blotting, in sera from patients with thyroid-associated ophthalmopathy (TAO), we quantitatively analyzed the binding activity with a rat eye muscle membrane 64 kDa protein using chromato-scanner. Eye muscle antibody activity was expressed as ratio of density of the 64 kDa band to that at 66 kDa found with all normal sera and phosphate buffered saline. The mean (+/- SD) eye muscle antibody activity was 2.7 +/- 2.7 in TAO (P < 0.01 v.s. normal), 1.5 +/- 1.7 in Graves' disease without evident eye disease, 1.6 +/- 2.5 in Hashimoto's thyroiditis and 0.45 +/- 0.26 in normal subjects. A positive band at 64 kDa was found in 71% of patients with TAO, 36% of those of Graves' disease without evident eye disease and in 35% of patients with Hashimoto's thyroiditis without eye disease. The prevalence of this antibody activity tended to correlate to the severity of ophthalmopathy. Furthermore, the level of eye muscle antibody activity decreased in parallel with the improvement of eye signs in two patients. Sera reactive with rat eye muscle membrane 64 kDa protein reacted also with a human eye muscle membrane 64 kDa protein but not with human thyroid, liver, spleen or pancreas membrane preparations. In conclusion, antibody to rat eye muscle membrane 64 kDa protein is present in TAO and may be a useful clinical marker of ophthalmopathy.

Adolescent↗