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Biomedical subjects

M Katagiri

Publications and source records attributed to M Katagiri.

At least 19 recordsLinked to original sources
PubMed1992

Steroid 6 beta-hydroxylase and 6-desaturase reactions catalyzed by adrenocortical mitochondrial P-450.

The minor steroid hydroxylase activity of purified bovine adrenocortical mitochondrial P-450 is described. The results indicate that both P-450scc and P-450(11 beta) act on deoxycorticosterone and androstenedione to form 6 beta-hydroxydeoxycorticosterone and 6 beta-hydroxyandrostenedione (6 beta-hydroxylase), respectively. Both forms of P-450 also catalyze 6-desaturation of androstenedione to form 4,6-androstadiene-3,17-dione (6-desaturase).

Adrenal Cortex↗
PubMed1992

Regulation of lipopolysaccharide- and IL-4-induced immunoglobulin heavy chain gene activation: differential roles for CD45 and Lyb-2.

We have demonstrated that CD45, a receptor-type protein tyrosine phosphatase, selectively regulates IgG production at the generative phase of precursors of IgG producers whereas Lyb-2 regulates IgG1 production induced by IL-4 in lipopolysaccharide (LPS)-activated B cells by acting on the generation of IgG1 precursor cells. These results point to an interesting possibility that both CD45 and Lyb-2 mediate a critical regulatory step(s) in IgG class switching. The present study was conducted to examine this possibility by elucidating the molecular mechanisms whereby CD45 and Lyb-2 control IgG synthesis in B cells activated by LPS and IL-4. Northern blot analysis showed that steady-state levels of C gamma 3, C gamma 2b and C gamma 1, but not Cmu, mRNA in LPS-activated B cells were reduced approximately 3- to 5-fold by CD45 mAb, and that the C gamma 1 mRNA level in B cells activated by LPS and IL-4 was significantly decreased by Lyb-2 mAb and CD45 mAb. Further, CD45 mAb inhibited expression of germline gamma 2b and gamma 3 transcripts induced by LPS and germline gamma 1 transcript expression induced by IL-4 plus LPS, but caused no inhibition in IL-4-induced germline gamma 1 transcript expression. In contrast, Lyb-2 mAb did not exert any inhibitory effect on the generation of germline gamma 1 transcripts induced by IL-4 and LPS or by IL-4 alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Hyalinizing trabecular adenoma.

A case is presented of hyalinizing trabecular adenoma in a 54-year-old Japanese female. The patient underwent a hemithyroidectomy for the diagnosis of thyroid carcinoma. An intraoperative frozen section diagnosis was medullary carcinoma. Hematoxylin and eosin stained permanent sections from the surgical specimen, a well encapsulated 3.0 x 2.0 x 1 cm nodule, also led us to suspect medullary carcinoma, but immunohistochemical staining for thyrocalcitonin, CEA, and thyroglobulin showed that it was a hyalinizing trabecular adenoma.

Adenoma↗
PubMed1992

[Analysis of the regulation of HLA class II genes by forskolin].

The expression of HLA class II molecules is mainly regulated transcriptionally and this regulation is thought to play an important role to the control of immune response. In this report, we have studied the effect of adenylate cyclase activator, forskolin, to the expression of HLA class II molecules on the cell surface of an human multiple myeloma cell line, RPMI8226. On the northern blot analysis and FACS analysis, we have revealed that forskolin upregulated the expression of mRNAs of DQB and DRB gene and their products on its surface. On the sequence analysis of upstream of HLA-DQB gene, we have identified not only Y-,X-, W-box, which were thought to regulatory region of truncated gene, but also cAMP responsible element (CRE) like regulatory region, which located upstream of W-box. On the gel retardation assay, when we used DNA probes that were specific for CRE like region and Y-box, we have found newly detectable bands, which appeared by forskolin treatment. These data suggest that forskolin upregulates HLA class II molecules by means of the interaction between CRE and cAMP responsible element binding protein (CREB).

Colforsin↗
PubMed1991

Immunochemical relationship of D-amino acid oxidases in various tissues and animals.

1. By means of an enzyme immunoassay, the contents of D-amino acid oxidase (DAO) were determined in kidney, liver, cerebellum and lung of hog, but the oxidase was not detectable in heart or cerebrum. 2. The oxidases in kidney, liver and cerebellum of hog were indistinguishable as regards immunoreactivity toward anti-hog kidney DAO antibody, specific activity and molecular weight. 3. The oxidases in rat and dog kidneys immunochemically cross-reacted with anti-hog DAO antibody. 4. The overall structure of the hog oxidase was more similar to that of the dog enzyme than that of the rat, while the structure around the catalytic site of the hog oxidase was more similar to that of the rat oxidase than that of the dog enzyme. 5. On immunoblot analysis, two forms of the oxidase were detected in extracts of hog, rat and dog kidneys.

Animals↗
PubMed1991

Mitochondrial P-450 activities in aldosteronoma tissues.

Adrenal P-450 activities were measured by an in vitro reconstitution system from tissues obtained from human aldosteronomata, and the results compared with those of the normal adrenal tissues from patients with Grawitz's tumor. The P-45011 beta activity was significantly increased in adenoma tissue (55.6 +/- 5.3 vs 9.0 +/- 6.2 nmol corticosterone/mg of protein/min in the control tissues, P less than 0.01). P-450scc activity in adrenal adenomata was 13.4 +/- 2.0 nmol pregnenolone/mg of protein/min, significantly higher than control (P less than 0.05). The present results suggest that increased mitochondrial P-450(11 beta) activities may be characteristic of aldosterone-producing adenomata.

Adenoma↗
PubMed1991

[Torsade de pointes ventricular tachycardia in a patient with acute myelocytic leukemia].

The anti-leukemic antibiotics, anthracyclines, are most effective agents in the treatment of acute leukemia. However, they have severe cardiac toxicities, which ordinarily shows dose-dependency, but sometimes produce acute cardiomyopathy. We experienced Torsade-de-pointes arrhythmia during the treatment of acute myelocytic leukemia (AML); The patient was a 28 year old woman and had an AML-M1. After the short course administration of daunorubicin (total 90 mg/m2) and aclarubicin (total 219 mg/m2), she suffered from an attack of Torsade-de-pointes ventricular tachycardia and passed away, since any treatment against ventricular arrhythmia was not effective. Autopsy studies revealed degeneration and atrophy of cardiac muscle in the area around His's bundle, which suggested an anthracycline-induced cardiac toxicity.

Aclarubicin↗
PubMed1990

Expression and function of a 90-kilodalton homodimeric molecule (10D1 antigen) on human thymocytes.

The 10D1 Ag is a 90-kDa homodimeric molecule specifically expressed on a subpopulation of human T cells, and is involved in an alternative pathway of T cell activation. In the present study, we have examined the expression and function of the 10D1 Ag on human thymocytes. Three-color FMF analysis showed that the 10D1 Ag was highly expressed on minor but distinct subpopulations of double-negative and CD4 single-positive thymocytes, and weakly on a part of double-positive thymocytes, but not on CD8 single-positive thymocytes. In double-negative thymocytes, the vast majority of 10D1+ cells were immature thymocytes of CD7+2+3- phenotype. Interestingly, 10D1 mAb could induce the proliferation of CD4 single-positive thymocytes in the presence of goat anti-mouse Ig to cross-link the 10D1 Ag. The treatment of thymocytes with OKT4 mAb plus C but not with OKT8 mAb plus C totally abrogated the proliferative response induced by 10D1 mAb, indicating that the 10D1-responsible thymocytes were of CD4+8- phenotype. This 10D1 mAb-induced thymocyte proliferation was perfectly dependent on the endogenous IL-2/IL-2R system since a complete inhibition was observed with anti-IL-2 and anti-IL-2R mAb. The proliferating CD4 single positive thymocytes predominantly expressed the IL-2R alpha (p55) but not a detectable level of the IL-2R beta (p75). These results indicate that, although the 10D1 Ag can be detected on the CD7+2+3-4-8- thymocytes, its functional expression is restricted to a minor more mature CD4+ thymocyte population as well as in peripheral blood T cells, and the implications of these findings are discussed.

Antibodies, Monoclonal↗
PubMed1990

Hydroxylation of 19-norandrostenedione by adrenal cortex mitochondrial P-450(11)beta.

The activity of purified bovine adrenocortical P-450(11)beta on the C18-steroid, 4-estrene-3,17-dione (19-norandrostenedione), is described. The major steroid products were separated by HPLC and identified by GC-MS, and 1H- and 13C-NMR as 11 beta-, 18- and 6 beta-hydroxylated derivatives of 19-norandrostenedione. The turnover numbers of the 11 beta-, 18- and 6 beta-hydroxylase reactions were 45, 7.5 and 1.9 (mol/min/mol of P-450(11)beta), respectively, with a common Km of 44 microM. All of these activities required the presence of the electron donating system consisting of NADPH, adrenal ferredoxin (adrenodoxin) and its reductase. These findings provide additional insights into the versatile catalytic roles of P-450(11)beta in the adrenal cortex, in which it may act on C18-19-nor-steroids in addition to its known activities on C21- and C19-steroids.

Adrenal Cortex↗
PubMed1990

A novel homodimeric molecule involved in human T cell activation.

A mAb, 10D1, was obtained by fusing spleen cells from BALB/c mice immunized with a CD3/TCR- human T cell line, P12/ichikawa, to mouse myeloma cells, P3X63-Ag8-653. 10D1 mAb is specific for T cells in that it reacted with all the T cell lines tested, but not with B or myeloid cell lines. A small fraction of normal peripheral blood T cells, preferentially CD4+, was also reactive with 10D1 mAb. Biochemical studies revealed that 10D1 mAb recognizes a disulfide-linked homodimeric molecule composed of 90-kDa polypeptide. 10D1 mAb induced a substantial proliferation of peripheral blood T cells when cross-linked with goat anti-mouse Ig antibody. The elimination of CD4+ cells totally abrogated the proliferative response induced by 10D1 mAb, whereas the elimination of CD8+ cells rather enhanced it. The proliferative response of peripheral blood T cells induced by 10D1 mAb was almost completely inhibited after modulation of the CD3/TCR complex with anti-CD3 mAb. In addition, a prompt increase in intracellular [Ca2+] was observed in a CD3+ T cell line, Jurkat but not in its surface CD3- mutant when 10D1 mAb was added. These results indicate that the 10D1 molecule is involved in a novel pathway of human CD4+ T cell activation, which is associated with the CD3/TCR-mediated pathway.

Antibodies, Monoclonal↗
PubMed1990

Expression of guanine nucleotide binding proteins, Gs and Gi, in mRNAs in epidermal keratinocytes.

The stimulation or inhibition of adenylate cyclase by hormones and chemicals is mediated by the stimulatory or inhibitory guanine nucleotide-binding proteins, Gs and Gi respectively. Although the presence of these G-proteins in the epidermis has been suggested, no direct information regarding their nature has been available. Using cDNAs for these G-proteins as a probe, we investigated the nature of the G-proteins of various keratinocytes. FRSK cells, a cell line derived from fetal rat epidermal cells, and SV-40-transformed human epidermal cells, both of which are highly proliferative keratinocytes, contained mRNAs for both Gs-alpha and two Gi-alpha proteins (Gi-2 alpha and -3 alpha). No evidence for the presence of Gi-1 alpha or Go-alpha was obtained. Normal human or pig epidermis had a relatively small amount of mRNAs for these G-proteins in the stable (hypoproliferative) condition. Tape-stripping-induced, and UVB-induced hyperproliferative epidermis contained an increased amount of these G-protein messages. However, all Gs-alpha, Gi-2 alpha and -3 alpha, as well as beta-actin mRNAs, were increased to a similar extent, and no specific expression of G-protein messages could be detected in the hyperproliferative epidermis.

Animals↗
PubMed1990

No evidence for the mutation of ras gene in psoriatic epidermis.

The ras oncogene product, ras p21, is structurally homologous to guanine nucleotide-binding proteins, which play an important role in transmembrane signaling systems. Recently, enhanced expression of ras p21 has been reported in the psoriatic hyperproliferative epidermis, in which various alterations in the transmembrane signaling systems are well established. Since ras-proto-oncogenes are known to be activated by a single point mutation that is restricted to the amino acid residues either at position 12, 61 or in their vicinity, we investigated whether the increased expression of ras p21 in psoriatic epidermis is accompanied by mutation of the ras gene at these sites. The results obtained using samples from five cases of psoriasis revealed no evidence for such mutation. Although the psoriatic epidermis may exhibit enhanced expression of ras p21, this is apparently not accompanied by ras mutation.

Amino Acid Sequence↗
PubMed1990

Signal transduction mechanisms of Ia induction in B cells by interleukin 4 and immunoglobulin receptors.

Molecular mechanisms of signal transduction through receptors for interleukin 4 (IL-4) are still largely unknown. To elucidate the second messenger(s) of IL-4 action in mature B cells, we performed blocking experiments with inhibitors of various aspects of cellular responses, using Ia-inducing activity of IL-4 as a readout system. In the event, only agents that are shown to inhibit calcium ion (Ca2+) release from intracellular stores, such as 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8) and ryanodine, could block the IL-4 action in a dose-dependent fashion. These results suggest that the process leading to the final expression of IL-4 action may be mediated, at some point, by the release of Ca2+ from intracellular stores. In the parallel experiments with antiimmunoglobulin (Ig) antibody, we found that amiloride, an inhibitor of Na+/H+ pump, blocks the Ia induction by anti-IgM antibody. Thus the Na+/H+ exchange system activated by anti-Ig antibody may be present in mature B cells.

Animals↗
PubMed1990

Adrenal P-450scc catalyzes deoxycorticosterone 6 beta-hydroxylase reaction.

Purified bovine P-450scc, the cholesterol side-chain cleaving P-450 in adrenal cortex mitochondria, was found to catalyze a deoxycorticosterone 6 beta-hydroxylase reaction. A turnover number (moles of product formed/min/mol of P-450) of 12 was found similar to that for cholesterol side chain cleavage activity. Conversion was dose-dependent in terms of P-450scc and no reaction took place when any one of the required electron donating components such as NADPH, NADPH-adrenodoxin reductase, or adrenodoxin was omitted. These results confirm and extend earlier observations that 21-hydroxypregnenolone is transformed into both deoxycorticosterone and 6 beta-hydroxydeoxycorticosterone by incubation of adrenal gland slices.

Adrenal Cortex↗
PubMed1990

Iodine-131 uptake in a patient with thyroid cancer and rheumatoid arthritis during acupuncture treatment.

A patient with thyroid carcinoma had abnormal accumulation of I-131 in the areas of both feet and hands on whole body scan. The sites of abnormal accumulation of I-131 were similar to those on bone scintigraphy. The radiographic examination of the lesions showed characteristic findings of rheumatoid arthritis, and the presence of small gold needles for acupuncture treatment was demonstrated. There were no findings of bone metastases. Although the mechanism of accumulation of I-131 in this patient is unknown, interpreters of I-131 whole body scintigraphs should keep this case in mind when acupuncture treatment has been done. The authors can only speculate on a common blood flow mechanism for enhanced HMDP and I-131 uptake in this arthritic patient who had been treated by acupuncture.

Acupuncture Therapy↗
PubMed1990

Hemostasis of the thyroid carcinoma invading the skin and trachea. Conservative treatment.

In most instances, the prognosis of well-differentiated thyroid carcinoma is generally favorable and adequately controlled by surgery alone. In some cases, however, in which the tumor has remained or in recurrent cases, infiltrates surrounding the skin or trachea can result in uncontrollable hemorrhage which cannot be treated with conventional medical or surgical therapy. We present our attempts at hemostatic procedures in such cases. When a thyroid cancer for which radical surgery is not indicated invades the skin with hemorrhage, we remove the ulcerated skin area with as much of underlying cancerous tissue as possible, and cover the defect skin area with a Bakamjian's deltopectoral flap or a musculocutaneous flap. In the 4 cases we have experienced, there had been no ulceration of the flap skin or recurrent. When a thyroid cancer invades the tracheal wall resulting in an intratracheal tumor accompanied by hemoptysis, we attempt to perform bronchoscopic cauterization using Nd-YAG Laser. Cauterization is repeatedly performed weekly, up to five times in one series. In all cases, radioiodine therapy is used before or after treatment. In all 4 cases we have experienced, hemostasis and shrinkage of the tumor was achieved. No complication such as ulcer formation or perforation was noted.

Aged↗
PubMed1990

[DNA sequence analysis of HLA-DQB genes associated with insulin-dependent diabetes mellitus in Japanese].

Recently it has been reported that 57th amino acid of DQ beta antigen was a non-aspartic acid in the most Caucasian patients with insulin-dependent diabetes mellitus (IDDM). Using serological analysis, HLA-DQ antigens show a strong association with IDDM rather than the HLA-DR antigens. In the Caucasian population, IDDM is associated with DQw2 and DQw3 antigens. However, in the Japanese population, DQw4 and DQw9 antigens are strongly associated with IDDM. In order to determine the possible significance of the 57th amino acid of DQ beta chain for the susceptibility to IDDM in Japanese, we performed DNA Sequence analysis of HLA-DQB from Japanese IDDM patient, its same HLA genotyped healthy sibling and B cell line with Japanese IDDM associated haplotype. The results revealed that all of the 57th amino acid are aspartic acid which is thought to contribute to develop IDDM resistance in Caucasian. Furthermore we could not find any other amino acid sequence of DQ beta chain which might contribute to the susceptibility of the Japanese IDDM.

Amino Acid Sequence↗