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Biomedical subjects

H Fukazawa

Publications and source records attributed to H Fukazawa.

At least 109 records · Page 6Linked to original sources
PubMed1989

Irreversible inhibition of v-src tyrosine kinase activity by herbimycin A and its abrogation by sulfhydryl compounds.

Herbimycin A, an antibiotic which reverses Rous sarcoma virus transformation, inhibited irreversibly the auto- and trans-phosphorylation activities of p60v-src in in vitro immune complex kinase assays. The addition of a sulfhydryl compound such as dithiothreitol, 2-mercaptoethanol, glutathione (reduced form) or cysteine abolished the ability of herbimycin A to inactivate p60v-src kinase as well as the ability to reverse transformed cell morphology, whereas the addition of oxidized glutathione, cystine or methionine showed no effect. The sulfhydryl alkylating reagent N-ethylmaleimide also, although less effectively, inactivated p60v-src kinase activity in vitro. These results suggest the likelihood that sulfhydryl groups of p60v-src are involved in the inactivation of v-src tyrosine kinase activity by herbimycin A.

Benzoquinones↗
PubMed1989

A nucleotide phosphodiesterase with preference for 2',5'-phosphodiester bonds from Ehrlich ascites carcinoma.

We have previously reported that many tumor cell lines express a 5'-nucleotide phosphodiesterase (phosphodiesterase I, EC 3.1.4.1) with properties clearly distinguishable from enzymes of normal tissues (Biochim. Biophys. Acta (1988) 966, 99-106). Such an enzyme with 5'-nucleotide phosphodiesterase activity was purified from Ehrlich ascites carcinoma by measuring the cleavage of thymidine 5'-monophosphate p-nitrophenyl ester (TMP-NP). The enzyme is a soluble protein, has a pH optimum of 7.5, and the molecular mass estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis is 67 kDa. The enzyme does not hydrolyze other chromogenic substrates for phosphodiesterases, nor pyrophosphate bond of various nucleotides which are cleaved by 5'-nucleotide phosphodiesterases of normal tissues. But, it hydrolyzes dinucleotides to form 5'-phosphates, and is more active on 2',5'- than on 3',5'-phosphodiester bonds. These results indicate that the TMP-NP splitting enzyme in Ehrlich ascites carcinoma cells is a 2',5'-phosphodiesterase.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1989

[Evaluation on facial pattern of early childhood patients with T.M.J. dysfunction occurred after anterior crossbite correction].

The purpose of this study was to investigate the facial pattern of early childhood patient with temporomandibular joint (TMJ) dysfunction (clicking) occurred after anterior cross-bite correction. Chincap appliance was engaged in all cases, with or without minor intraoral mechano-therapy. Materials were consisted of lateral and postero-anterior cephalograms of 50 japanese patients (6-9 years old), all showing anterior cross-bite with normal function of TMJ at pre-treatment stage. They were consisted of two groups, one was the group of 22 patients with TMJ dysfunction occurred after cross-bite correction and the other was the control group of 28 patients with no TMJ problem. Morphological measurements were done and compared between two groups. The results were as follows: 1) There was no significant difference between the TMJ group and the control group from the lateral facial pattern. 2) The upper and middle facial skeleton were symmetry in both groups, but the maxillary alveolar legion (CMo, U 1) of TMJ group was significantly from the antero-posterior view. 3) On the lower face (mandible) of the TMJ group, it was pointed out that the position of Gonion was significantly asymmetry and L 1 point and Menton were disclosed to have severe lateral displacement. It was cleared that a high incidence of temporomandibular joint dysfunction was found in mandibular asymmetry cases. It was concluded that a careful case-management is required for mandibular asymmetry patients during chicap-orthodontic therapy.

Cephalometry↗
PubMed1989

[Therapeutic analysis of autopsy findings in oral cancer].

Thirty-four autopsied patients with oral squamous cell carcinoma were analyzed by multiple regression analysis. The following results were obtained. 1) The suggested metastatic spread was from the highest count of oral cancer patients with metastases in lung to lower key organs, reflecting the cascade theory. 2) Multiple regression analysis revealed that local recurrence was significantly related to the treatment method, indicating that multidisciplinary treatment would be needed. 3) Multiple regression analysis indicated that mediastinal lymph node metastasis was significantly related to both the age of the patient and the stage of cancer development. 4) Multiple regression analysis showed that distant metastasis was significantly related to both the stage and the spleen weight. 5) There were many patients with the pulmonary metastases undergoing irradiation which ranged from 40Gy to 60Gy on the primary tumor. 6) Results showed that immunotherapy tended to control pulmonary metastases.

Adult↗
PubMed1988

Transamination of LTE4 by cysteine conjugate aminotransferase.

Leukotriene E4 (LTE4) was transaminated to 5(S)-hydroxy-6(R)-S-(2-keto-3-thiopropionyl)-7,9-trans-11,14-cis- eicosatetraenoic acid (tentatively designated as LTG4) by cysteine conjugate aminotransferase I purified from rat liver supernatant in the presence of alpha-ketoglutaric acid or alpha-keto-gamma-methiolbutyric acid. The transamination activity was present in the kidney as well as in the liver, but not in the lung or leukocytes.

Animals↗
PubMed1988

5'-Nucleotide phosphodiesterase and alkaline phosphatase in tumor cells: evidence for existence of novel species in the cytosol.

Characteristics of 5'-nucleotide phosphodiesterase (phosphodiesterase I, EC 3.1.4.1) and alkaline phosphatase (EC 3.1.3.1) activities in tumor cell lines of human and murine origin were examined. Of the 15 cell lines tested, 5'-nucleotide phosphodiesterase activity in 13 cell lines and alkaline phosphatase activity in 10 cell lines were inhibited by N-ethylmaleimide and activated by dithiothreitol (N-ethylmaleimide-sensitive), and suggested to be SH-enzymes. In contrast, the two phosphohydrolases from normal tissues were inactivated by dithiothreitol, but not by N-ethylmaleimide (dithiothreitol-sensitive). There was only one tumor cell line in which both activities were dithiothreitol-sensitive. Human hepatoma PLC/PRF/5 cells appear to possess both types of 5'-nucleotide phosphodiesterase and alkaline phosphatase, and the subcellular distribution of these enzymes in this cell line was investigated. Dithiothreitol-sensitive 5'-nucleotide phosphodiesterase and alkaline phosphatase of PLC/PRF/5 cells were localized in the plasma membrane as in normal tissues, but N-ethylmaleimide-sensitive phosphohydrolases were soluble cytosolic proteins. N-Ethylmaleimide-sensitive 5'-nucleotide phosphodiesterase and alkaline phosphatase activities from other cell lines were also recovered in the cytosol. Molecular masses of cytosolic N-ethylmaleimide-sensitive phosphohydrolases were apparently smaller than their membrane-bound dithiothreitol-sensitive counterparts, as judged from gel filtration. It was concluded that many tumor cell lines lack plasma membrane 5'-nucleotide phosphodiesterase and alkaline phosphatase, but express enzymes with similar activities in the cytosol, with properties clearly distinguishable from enzymes so far characterized.

Alkaline Phosphatase↗
PubMed1988

Role of autoantibodies in the pathogenesis and association of endocrine autoimmune disorders.

This review has focused on the nature and significance of aAB detected in the serum of patients with EAD. Although many antibodies are characteristically detected in the serum of patients with such disorders, only a few are of known pathogenic significance. Antibodies that react with soluble cytoplasmic antigens are not expected to be harmful. On the other hand, membrane or cell surface-directed antibodies are likely to be damaging, either by lysis of the cell membrane, or by reaction with hormone or other surface receptors. Clinically, measurement of aAB has important diagnostic and management value. Moreover, detection of certain antibodies before the onset of disease raises hope that the corresponding disorders may be preventable, e.g. by specific immunosuppression of those subjects, or patients, with positive tests. The possible role of aAB in the association of organ-specific AID by cross-reacting with shared epitopes in various tissues has been highlighted by the recent finding, from the authors' laboratory, of antibodies reactive with a 64-kDa membrane protein found in several tissues, including thyroid, eye muscle, and pancreas, which are frequent sites for autoimmune inflammation. Study of such antibodies and the molecular characterization of the corresponding antigens in the various involved tissues should provide information concerning the role of cross-reactivity in autoimmunity as well as leading to the development of specific immunotherapeutic agents.

Adrenal Cortex↗
PubMed1988

A thyroid cytotoxic antibody that cross-reacts with an eye muscle cell surface antigen may be the cause of thyroid-associated ophthalmopathy.

A hitherto unrecognized thyroid antibody, which reacts with a thyroid cell surface antigen expressed on passaged thyroid cells, was identified in serum from patients with thyroid-associated ophthalmopathy using antibody-dependent cell-mediated cytotoxicity (ADCC) tests. The antibody was detected in 14 of 23 patients with Graves' hyperthyroidism (Gh) and associated ophthalmopathy, in 3 of 4 patients with Hashimoto's thyroiditis (HT) and ophthalmopathy, but in only 1 of 16 patients with Gh without clinically evident eye disease and 4 of 37 patients with HT without eye disease. The ADCC test also was positive in 2 of 30 patients with thyroid cancer, both of whom had had Gh and ophthalmopathy in the past. There was no correlation, in patients with ophthalmopathy, between the levels of the antibody (expressed as percent specific lysis) and the titers of antithyroid microsomal antibody measured using a hemagglutination assay. Based on the results of blocking experiments using mouse monoclonal antibodies against human thyroid peroxidase, now known to be the thyroid microsomal antigen, the corresponding antigen was not thyroid peroxidase. Moreover, the new antigen was expressed on cultured and passaged thyroid cells which do not express the microsomal antigen. In patients with ophthalmopathy there was a close correlation between the degree of lysis of passaged thyroid cells and that of eye muscle cells, and ADCC activity against passaged thyroid cells was absorbed by preincubation of positive serum samples with eye muscle and thyroid cell, but not other cell, monolayers. The reaction of a newly identified cytotoxic thyroid antibody with a shared epitope on eye muscle cells thus appears to be a possible mechanism for the development of ophthalmopathy in patients with Gh and, less often, HT.

Adolescent↗
PubMed1988

Recurrence of subacute thyroiditis over 10 years after the first attack in three cases.

We saw a total of 4 episodes of the recurrence of subacute thyroiditis in 3 patients out of 222. The recurrent episodes were similar to the first episodes of subacute thyroiditis. The titers of various viral antibodies were not increased significantly during the clinical course of the recurrence. Regarding the HLA typing, A26, B35 and C3 were positive in all 3 patients. The association between the occurrence of subacute thyroiditis and the presence of HLA-B35 and C3 has hitherto been reported, although the association of HLA-A26 with recurrent type of subacute thyroiditis was observed and described for the first time in this report. It is suggested that HLA-A26 may somehow be related to the predisposition to the recurrence of subacute thyroiditis which developed after more than 10 years.

Adult↗
PubMed1988

Purification and characterization of cysteine conjugate transaminases from rat liver.

1. Soluble cysteine-conjugate alpha-ketoglutarate transaminase (CAT-I) was purified about 670-fold from rat liver cytosol using s-(p-bromophenyl)-L-cysteine as amino acid substrate. The enzyme preparation of the final step of purification showed a single band in polyacrylamide gel electrophoresis. CAT-I accounted for 64% of the transaminase activity in cytosol. 2. The mol. wt of the enzyme was about 64,000 as determined by gel filtration. Respective Km values for s-(p-bromophenyl)-L-cysteine and alpha-ketoglutaric acid were 1.0 and 1.3 mM in Tris-acetate buffer (pH 7.0). Aminooxyacetic acid, hydroxylamine, and KCN inhibited the enzyme activity. 3. In addition to CAT-I, two isozymes (CAT-IIA and CAT-IIB) were partially purified from rat liver cytosol. In respect of mol. wt, substrate specificity towards cysteine conjugates, and several other properties, CAT-IIA and CAT-IIB were very similar to CAT-I. However, differences were observed for these enzymes in the rate of reverse reaction (formation reaction of cysteine conjugates and alpha-ketoglutaric acid) and substrate specificity towards L-aspartic acid and L-cysteinesulphinic acid.

Animals↗
PubMed1988

Involvement of cystathionase in the formation of alkane-thiols from corresponding cysteine conjugates.

1. Rat liver cystathionase [EC.4.4.1.1] mediated a cleavage reaction of the C-S bond of S-alkyl-L-cysteine conjugates to give equimolar amounts of corresponding thiols, ammonia, and pyruvic acid. Neither S-aryl- nor S-aralkyl-L-cysteine conjugates were acceptable substrates. 2. The Km value for S-(tert-butyl)-L-cysteine was 0.3 mM at pH 8.5 in Tris-HCl buffer. 3. The S-alkyl-L-cysteine lyase activity of cystathionase was inhibited with carbonyl reagents and dithiothreitol. 4. The present finding that cystathionase has activity towards cysteine conjugates may provide some insights into the role of this enzyme in the metabolism of xenobiotics.

Alkanes↗
PubMed1988

[Morphological relationship between maxillary sinus and skeletal facial type].

The purpose of this study was to investigate the variation of the morphology of maxillary sinus in relation to the skeletal facial type. The materials consisted of lateral cephalometric roentgenograms of 100 adult Japanese females. Nine features representing the form of maxillary sinus were selected and the principal component analysis was carried out to determine the characteristics of sinus morphology. The following results were obtained. The form of maxillary sinus seems to mainly influence (or be influenced by) the antero-posterior facial symptom rather than the vertical facial symptom. A case which had a large SNA angle presented a tendency to have a maxillary sinus with a larger antero-inferior portion and more upright anterior wall. The results indicate that the occlusal function may relate to the formation of the maxillary sinus.

Adult↗
PubMed1988

Dermal dysplasia characterized by collagen disorder-related skin fragility in a cow.

Holstein cow 1 was examined because of skin fragility and delayed healing of skin wounds, which were markedly exacerbated around the time of parturition. A skin biopsy sample was obtained, and light microscopy revealed irregular deposition of thin collagen fibers in a dermal matrix. Although diffuse inflammation did not occur, the number of plump fibroblasts was increased. Electron microscopy revealed poor construction of collagen fibrils in the dermal matrix. Biochemical analysis of the dermis revealed a normal amount of collagen and uronic acid, but sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed an increased proportion of soluble alpha-, beta-, and gamma-collagen chains of normal molecular weights. Neither procollagen nor its intermediates devoid of amino- or carboxy-terminal extension peptide were observed. Dermal collagen from cow 1 was more soluble in a neutral salt solvent, 0.5M acetic acid, and the acid containing pepsin than was dermal collagen from healthy cow 2. The peptic digestion profile of dermis from cow 1 revealed a lowered degree of intermolecular cross-linking and destabilization of helical structure in the dermis collagen. The extrahelical peptic cleavage of collagen before cyanogen bromide digestion resulted in release of more fragments derived from carboxy-terminal part of alpha 1 chains in dermis of cow 1 than in dermis of healthy cow 2.

Animals↗
PubMed1987

Purification and properties of methyl sulfoxide reductases from rat kidney.

Two kinds of enzymes (tentatively designated methyl sulfoxide reductases I and II) responsible for the reduction of the methyl sulfoxide group on various xenobiotics have been purified about 223- and 155-fold, respectively, from rat kidney cytosol. The molecular weight was determined to be 12,000 +/- 1000 for methyl sulfoxide reductase I and 24,000 +/- 1000 for methyl sulfoxide reductase II. Thioredoxin or dithiothreitol is essential in order for the reducing activity to occur. The respective Km values of p-bromophenylmethyl sulfoxide were 2.75 and 1.30 mM for methyl sulfoxide reductases I and II. Replacement of the methyl group on the sulfur atom with a longer alkyl group or phenyl group caused a markedly low or negligible substrate activity.

Animals↗
PubMed1987

Effect of prednisolone and salicylate on serum thyroglobulin level in patients with subacute thyroiditis.

Twelve patients with subacute thyroiditis were divided into two groups and treated with prednisolone or salicylate. The initially elevated T4, T3, free T4 (FT4), free T3 (FT3) and erythrocyte sedimentation rate (ESR) were reduced during the early phase within about 4 weeks in both groups. The serum levels of thyroglobulin (Tg) were elevated in both groups treated with salicylate and prednisolone (252 +/- SD 117 ng/ml and 233 +/- SD 157 ng/ml, respectively) at initial examination. The serum level of Tg declined during the early phase with prednisolone treatment, and it reached normal values at the end of the early phase (17 +/- SD 15 ng/ml). With salicylate treatment, the decline of levels of Tg was delayed and it was elevated (80 +/- SD 34 ng/ml) despite normal levels of thyroid hormones and ESR at the end of early phase. The serum level of Tg at the end of the early phase of prednisolone treated was significantly lower than that of salicylate treatment (P less than 0.01). It is suggested that the effect of prednisolone on rapid decrease of Tg may be related to its inhibitory action of intrathyroid hydrolysis.

Adult↗