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Biomedical subjects

T Miyake

Publications and source records attributed to T Miyake.

At least 271 records · Page 15Linked to original sources

[Hairy cell leukemia of European-American type with dual T and B-cell phenotype].

A 46-year-old woman was admitted because of palpitation and conjunctival jaundice. Physical examination revealed hepatosplenomegaly and purpura without lymphadenopathy. Blood count showed 4.7 g/dl hemoglobin with increased reticulocytosis. The platelet count was 1.5 X 10(4)/microliters and the leukocyte count was 6,000/microliters with 17% abnormal mononuclear cells (hairy cells). Hairy cells had nuclei of frequently folded shape and abundant cytoplasma with irregular edges on blood films. The hair-like cytoplasmic projections of the cells were clearly seen under the phase-contrast microscopy. Hairy cells were strongly positive for tartrate resistant acid phosphatase. Bone marrow aspiration was unsuccessful. The biopsy specimens showed small patchy and scattering infiltrations by hairy cells. Surface marker studies of hairy cells revealed that they were strongly positive for SmIg (IgG kappa). They also reacted with alpha B 1, alpha Tac, alpha Leu-M 5 monoclonal antibodies and a rabbit anti-hairy cell serum (alpha HC-M). 53% of hairy cells were shown to react with alpha B 1 and alpha OKT 11 simultaneously by double labelling. The southern blot analysis of peripheral blood mononuclear cells showed IgH chain genes rearrangement and germ line patterns of T-cell receptor genes. Hemolysis was promptly disappeared after blood transfusion. Moreover, the red blood cells, platelets and leukocytes have spontaneously returned to normal levels with disappearance of circulating hairy cells and palpable spleen one year after admission.

B-Lymphocytes↗

Lectin histochemistry in rat thyroid tumours.

The thyroid tumours and background goiterous and adenomatous lesions induced in rats with diisopropanolnitrosamine (DIPN) plus methylthiouracil (MTU), and regenerative thyroid tissues after wounding were studied by lectin histochemistry. Ten weeks after cessation of the carcinogen treatments, carcinomas invading the surrounding tissues and blood vessels (13/20) and papillary micronodules (11/20) were formed in the thyroid tissues. In general, the carcinoma lesion was solitary, and the papillary micronodules were multiple in a single thyroid gland. Among the lectins tested, Maclura pomifera (MPA) and Solanum tuberosum (STA) showed specific binding with both carcinoma and papillary micronodule lesions, but not with the background goiterous and adenomatous lesions and regenerative thyroid tissues. The former both lesions showed higher labelling indices with BUdR or 3H-thymidine and poorer thyroglobulin accumulation than the latters, thereby indicating their enhanced proliferative capability and depressed potency of cyto-differentiation. The common cytological and histochemical properties of carcinoma lesions and papillary micronodules allow us to regard the latter as pre-invading carcinoma lesions. The lectins MPA and STA may be, therefore, used as the specific markers of malignancy in rat thyroid carcinogenesis.

Animals↗

Stereoselective syntheses of C-(D-glucopyranosyl)alkenes.

alpha-D-Glucopyranose pentaacetate (1) was found to undergo stereoselective conversion in good yield into 3-(tetra-O-acetyl-alpha-D-glucopyranosyl)-1-propene (4) by treatment with allyltrimethylsilane and boron trifluoride etherate in acetonitrile. Similar treatment of methyl tetra-O-acetyl-alpha-D-glucopyranoside or tetra-O-acetyl-alpha-D-glucopyranosyl bromide also gave 4 in preference to its beta anomer, but net yields were lower. Similar reaction of 1 with (E)-penta-2,4-dienyltrimethylsilane afforded the readily polymerizable 5-(tetra-O-acetyl-alpha-D-glucopyranosyl)-(E)-1,3-pentadiene, accompanied by a minor proportion of its beta anomer.

Alkenes↗

[Analysis of experimental autoimmune oophoritis as a model of premature ovarian failure].

Neonatal thymectomy in mice at 3 days of age (Tx-3) can induce autoimmune oophoritis and results in complete loss of oocyte at young adult age. We examined endocrinological and immunological abnormalities in Tx-3 (C3H/He X A/J)F1 female mice to find some similarities to premature ovarian failure (POF) in humans. The majority of the Tx-3 mice showed irregular estrous cycles during 7 to 9 weeks of age then fell into continuous diestrous. Endocrinological analysis of Tx and sham-Tx mice revealed that serum gonadotropin levels (LH and FSH) of Tx-3 mice rapidly increased from 8 weeks of age and serum estradiol levels significantly decreased from 10 weeks of age (P less than 0.05). In contrast with estradiol, serum androstenedione levels significantly increased from 10 weeks of age (P less than 0.01). In the mice with oophoritis, circulating autoantibodies against ooplasm and/or zona pellucida determined by immunoperoxidase method could be detected from 6 weeks of age, became high titer from one or two weeks later, but resulted in low titer or negative test from about 4 months of age. Acute loss of oocyte with massive mononuclear cell infiltration coincident with the appearance of these autoantibodies were progressed, and then atrophic ovaries with complete destruction of follicles were seen at 3 months of age. This experimental model of autoimmune oophoritis abounds in suggestion for the understanding of one of the possible etiology of POF in women.

Androstenediols↗

Quantitative studies on proliferative changes of reactive astrocytes in mouse cerebral cortex.

Cell number and proliferation of reactive astrocytes were studied quantitatively in the stabbed cerebral cortex of adult mice, using immunohistochemistry for glial fibrillary acidic protein (GFAP) and [3H]thymidine autoradiography. GFAP-positive astrocytes increased in cell number gradually from 24 to 96 h after stabbing, and their immunoreactivity became intense. The maximum number of GFAP-positive cells was about 4.5 times normal in the layers II-VI of the cortex, whereas it was only 1.5 times normal in the layer I (molecular layer). In contrast to the gradual increase in cell number, no GFAP-positive astrocytes were labeled with [3H]thymidine prior to 48 h after stabbing, in either the layer I or the layers II-VI. Then 3-5% of them were labeled at 72 and 96 h, but very few again after 6 days. By injecting [3H]thymidine successively for 6 days after stabbing, only 17% of GFAP-positive astrocytes of the layer I or the layers II-VI were labeled. These results reveal that, in the cortical layers II-VI, many GFAP-negative source cells initially express much more GFAP-antigen without proliferation and change into GFAP-positive reactive astrocytes. Proliferation of reactive astrocytes is not the major factor for the marked increase in number of them. The cortical layer I would have few GFAP-negative source cells for reactive astrocytes. These source cells may be protoplasmic astrocytes.

Animals↗

Immunohistochemical examination of Peyer's patches in autoimmune mice.

The distribution of T-cells and B-cells in Peyer's patches was examined in three autoimmune model mice, MRL/Mp-lpr/lpr, BXSB, NZBWF1/J mice and normal BALB/c mice, between one and ten months old. A multiple layering technique was used for immunohistochemical detection of lymphocyte surface antigens of T-cells (Thy1.2, Lyt1, Lyt2) and B-cells (surface IgM) and peanut agglutinin receptor for germinal center cells. The T-cell population of female MRL/Mp-lpr/lpr mice increased markedly with age, and the B-cell population of the male BXSB mouse tended to increase. However, little change was observed with age in the NZBWF1/J mice. The immunohistochemical properties of the Peyer's patches in the three autoimmune model mice were different.

Animals↗

A quantitative analysis of human astrocytosis.

The number of astrocytes in an atrophic human brain was counted with the aid of immunohistochemistry for glial fibrillary acidic protein. Microscopically, astrocytosis was remarkable in the cerebral neocortex and white matter. Taking the cortical atrophy into consideration, however, the total number of astrocytes in the cortical layers II-VI was not increased. The number of astrocytes in the white matter was not increased either. It is indicated that astrocytosis does not always mean hyperplasia (net increase of total number) of astrocytes.

Astrocytes↗

Acute oocyte loss in experimental autoimmune oophoritis as a possible model of premature ovarian failure.

A high incidence of autoimmune oophoritis can be induced in (C57BL/6Cr x A/J)F1 mice that were thymectomized at 3 days of age. The vaginal opening day was significantly delayed (thymectomized mice [n = 35], 38.1 +/- 5.8 days [mean +/- SD] versus sham thymectomized mice [n = 26], 34.0 +/- 5.2 days; p less than 0.02). Most of the thymectomized mice showed irregular estrous cycles during the first several weeks and then fell into continuous diestrus. Local infiltration of mononuclear and plasma cells inside and around growing follicles was a prominent feature in the early stage of oophoritis. This abnormal feature was first noticed at 24 days of age and progressed in the follicular units. Acute loss of oocytes, especially of growing follicles, with massive mononuclear cell infiltration rapidly progressed after puberty, and atrophic ovaries with complete destruction of both primordial and growing follicles were then seen for 1 to 2 months after puberty. In mice with oophoritis, circulating autoantibodies against, ooplasm, zona pellucida, or steroid-producing cells were constantly detected by immunohistochemical assay. Autoimmune thyroiditis and gastritis accompanied by specific circulating antibodies were also detected in mice thymectomized at 3 days of age. This experimental model may serve as a tool for studying premature ovarian failure in humans.

Animals↗

Low molecular weight RNA of Drosophila cells which is induced by heat shock--II. Structural properties.

Heat shock-induced small cytoplasmic RNA (HSI scRNA) from Drosophila culture cell was larger in size after dimethylchloroacetal treatment than in 7 M urea. Judging from its thermal denaturation profile and the nuclease S1 digestion experiment it was supposed that HSI scRNA is double-stranded. Nucleotide sequence analysis of the scRNA also suggested that it is double-stranded RNA with the blunt-ends.

Animals↗

Biosynthesis of a protein containing a nonprotein amino acid by Escherichia coli: L-2-aminohexanoic acid at position 21 in human epidermal growth factor.

Endeavoring to develop a method to biosynthesize proteins substituted with nonprotein amino acids, we attempted the incorporation of L-2-aminohexanoic acid (Ahx) into human epidermal growth factor (hEGF). Escherichia coli YK537 strain harboring plasmid pTA1522, which has the phoA promoter-phoA signal peptide-hEGF gene, was used. Cells were cultured first in high-phosphate medium and then, for induction of the hEGF-encoding gene, transferred to low-phosphate medium containing Ahx (0.25 mg/ml). hEGF and Ahx-substituted hEGF, [Ahx21]hEGF, secreted into the periplasm were recovered. After treatment with H2O2, [Ahx21]-hEGF was clearly separated from methionine-oxidized hEGF by one-step reverse-phase HPLC. Substitution of the methionine residue of hEGF with Ahx was confirmed by the amino acid analysis of [Ahx21]hEGF. The three biological activities of [Ahx21]hEGF were the same as those of hEGF. From the successful production of [Ahx21]hEGF, a basic strategy was established for preparing proteins substituted with nonprotein amino acid (alloprotein). Induction of the phoA promoter of pho regulon and secretion of the product to the periplasm may depress heat shock-like responses and subsequent hydrolysis of the product by cytoplasmic protease.

Aminocaproates↗

Synthesis of recombinant human single-chain urokinase-type plasminogen activator variants resistant to plasmin and thrombin.

Single-chain urokinase-type plasminogen activator (scu-PA), a potential therapeutic reagent for thrombosis, is activated in plasma by plasmin. The activated enzyme is further digested by plasmin to generate low-molecular-weight urokinase (LMW-UK), which has no affinity for fibrin. To circumvent this dual effect of plasmin, we synthesized in Escherichia coli a variant of scu-PA, which is not converted to LMW-UK on treatment with plasmin. In another variant, the activation cleavage site was modified such that activation by plasmin was slowed down and that inactivation by thrombin was greatly diminished. The combination of these variants may be applicable as an effective thrombolytic reagent for clinical use.

Drug Resistance↗

Effects of 16,16-dimethyl-prostaglandin E2 on ammonia- and ethanol-induced mucosal lesions in the rat.

The effect of necrotizing agents, such as ammonia and ethanol, on the gastric mucosa was compared. Intragastric administration of ammonia (0.6-1.0%) and ethanol (60-100%) produced hemorrhagic necrosis of gastric mucosa in a concentration-dependent manner. In the anesthetized rat, the macroscopic lesions induced by ethanol were significantly inhibited by pretreatment with 3 or 10 micrograms/kg of 16,16-dmPGE2, but the lesions induced by ammonia were not inhibited by either 3 or 10 micrograms/kg of 16,16-dmPGE2 in the anesthetized rat. The decrease of gastric transmucosal potential difference and mucosal blood flow produced by ethanol (100%) were significantly attenuated by 16,16-dmPGE2; however, those produced by ammonia (1%) were not inhibited by 16,16-dmPGE2 in the anesthetized rat. In conscious rats, ammonia-induced lesions were not inhibited by pretreatment with 3 micrograms/kg of 16,16-dmPGE2 but they were significantly reduced by the pretreatment of 10 micrograms/kg of 16,16-dmPGE2. These results show that 16,16-dmPGE2 afforded little protection against ammonia-induced gastric lesions in the anesthetized rat and suggest that a different mechanism is involved in the development of gastric mucosal lesions between those induced by ethanol and those induced by ammonia.

16,16-Dimethylprostaglandin E2↗

Characterization of serum platelet-activating factor (PAF) acetylhydrolase. Correlation between deficiency of serum PAF acetylhydrolase and respiratory symptoms in asthmatic children.

Platelet-activating factor (PAF) acetylhydrolase has been recognized as an enzyme that inactivates PAF. We developed a convenient and reproducible method for determining human serum PAF acetylhydrolase activity. The assay was based on measurement of [14C]acetate produced from 1-O-alkyl-2-[14C]-acetyl-sn-glycero-3-phosphocholine upon precipitation of the complex of radioactive substrate and albumin with TCA. The apparent Km value of PAF acetylhydrolase (near the physiological concentration of serum protein) was 1.5 X 10(-4) M PAF. 32 subjects with serum PAF acetylhydrolase deficiency were found among 816 healthy Japanese adults. The low PAF acetylhydrolase activity in the deficient serum might not be due to the presence of enzyme inhibitor. Both the sensitivity to PAF and the metabolism of PAF in platelets from PAF acetylhydrolase-deficient subjects were almost the same as those of normal subjects. Deficiency in serum PAF acetylhydrolase appeared to be transmitted by autosomal recessive heredity among five Japanese families. Among healthy adults, healthy children, and asthmatic children, who were grouped into five classes on the basis of respiratory symptoms (remission, wheezy, mild, moderate, and severe groups), the probability of PAF acetylhydrolase deficiency was significantly higher in groups with severe symptoms (moderate and severe) (P less than 0.01). These results suggest that deficiency of serum PAF acetylhydrolase might be one of the factors leading to severe respiratory symptoms in asthmatic children.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

[Anti-ulcer mechanism of mezolidon on water-immersion stress induced gastric ulcers in rats].

To elucidate the anti-ulcer mechanism of mezolidon (KM-1146, 2-(3,4-dimethoxyphenyl)-5-methylthiazolidine-4-one), we investigated gastric mucosal blood flow (laser-Doppler method), transmucosal potential difference, gastroduodenal mucosal surface pH and blood viscosity in rats under a water-immersion stress condition. In the control group, gastric mucosal ulcers occurred three hours after the onset of water-immersion. At that time, gastric mucosal blood flow decreased to 40% and the potential difference decreased to 48%. In the mezolidon-pretreated group, gastric mucosal ulcers were significantly reduced, and the potential difference was significantly higher than in the control group. Gastric mucosal blood flow increased significantly to 120% twenty minutes after the onset of water-immersion and then decreased, but was significantly higher than in the control group. Gastroduodenal mucosal surface pH was not affected by the pretreatment with mezolidon under this condition. Pretreatment with mezolidon did not affect blood viscosity. In conclusion, the anti-ulcer effect of mezolidon may involve the increase and/or maintenance of gastric mucosal blood flow, but more investigations are necessary to understand the mechanism involved.

Animals↗

Effect of ammonia on the gastric mucosa in rats: pathophysiological importance of urease in gastric ulcer disease.

We examined the pathophysiological roles of the urea-urease-ammonia system in gastric ulcer disease using rats. Exposure of the stomach to ammonia (0.01-1.0%) decreased the transmucosal potential difference (PD) and histological injury in a concentration-dependent manner. Exposure of the stomach for 20 min to urea (0.025-0.2%) together with urease (100 IU) produced a decrease in PD and microscopic injury similarly, and the lesion was closely associated with the amount of ammonia produced. Urea and urease alone had no effect on the gastric mucosa. These results suggested the pathophysiological importance of urea, urease and ammonia in gastric ulcer disease.

Ammonia↗