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Biomedical subjects

Y Ohba

Publications and source records attributed to Y Ohba.

At least 235 records · Page 13Linked to original sources
PubMed1986

Abnormal arrangements in the alpha- and gamma-globin gene clusters in a relatively large group of Japanese newborns.

Data were obtained on blood samples from a relatively large group (264) of healthy Japanese newborns, collected at hospitals in Tokyo, Kurashiki, and Ube. The studies included an evaluation of anomalies in alpha-globin gene and gamma-globin gene arrangements using gene mapping and gamma-chain composition analyses. The results confirmed the rarity of alpha-thalassemia among Japanese; only a few babies had alpha-thalassemia-2 trait (the -3.7-kilobase [kb] deletion), while others had alpha-globin gene triplications (both the alpha alpha alpha anti-3.7 and the alpha alpha alpha anti-4.2 types). Among the gamma-globin gene anomalies that were observed, a few babies had the -A gamma-A gamma- globin gene arrangement or the -G gamma A gamma- type of deletion. The gamma-chain triplication (-G gamma-A gamma G gamma-A gamma-) occurred in 10 out of 256 newborns, and its frequency exceeded that of its corresponding -G gamma A gamma- deletion by a factor of 5. The restriction endonuclease XmnI was a useful tool, in addition to the enzymes Bg1II and BclI, to evaluate and confirm the gamma-globin gene deletion and triplication. The A gamma T variant, which is the product of a mutant A gamma-globin gene, occurred at a frequency of 0.156. The chromosome carrying this mutant A gamma gene had a characteristic haplotype that was originally seen in black and Mediterranean patients with Hemoglobin (Hb) S or with beta-thalassemia.

Chromosome Mapping↗
PubMed1985

Identification and initial characterization of transforming growth factor-like mitogen(s) in human anterior pituitary.

Transforming growth factor (TGFs) are a family of peptide(s) defined by their ability to induce anchorage-independent growth of non-neoplastic indicator cells in soft agar. We found that acid-ethanol extracts of human anterior pituitary tissues were able to stimulate colony growth of normal rat kidney fibroblasts in soft agar. When subjected to gel-filtration on a column of Bio-Gel P-60 in 1 M acetic acid, the majority of TGF activity eluted in fractions corresponding to an apparent mol wt 15,000. The activity was heat- and acid-stable, but was inactivated by treatment with trypsin and dithiothreitol. Pituitary TGF-like materials did not compete with epidermal growth factor (EGF) for receptor binding and did not require EGF for colony-forming activity. Thus, human pituitary TGF was not like type alpha or type beta TGF.

Binding, Competitive↗
PubMed1985

Phosphorylation of five histone H1 subtypes of L5178Y cells at the exponential growth and mitotic phases.

Histone H1 of cells of L5178Y, a mouse lympholeukemic cell line, consists of five molecular species designated as H1-I, II, III, IV, and V. The phosphorylation of these H1 subtypes was examined at the exponential growth phase and during mitosis, by BioRex 70 column chromatography and two-dimensional polyacrylamide gel electrophoresis. In exponentially growing cells, the degree of phosphorylation was different for each subtype. H1-II was the most highly phosphorylated, 1.8 phosphate residues per molecule, followed by H1-IV/V, 1.4, I, 0.8, and III, 0.5. In the mitotic phase, H1-II was also the most highly phosphorylated 6.0 phosphate residues per molecule, H1-IV/V, 3.5, I, 2.7, and III, 1.2. The phosphorylation started simultaneously among the subtypes after colcemid addition, and phosphorylated H1 subtypes accumulated linearly. The rate of incorporation of 32P into each H1 subtype was almost constant during colcemid treatment. During 4 h after colcemid addition, the phosphate residues incorporated into H1 did not dephosphorylated. The H1 kinase activities increased to six times higher during the colcemid treatment.

Animals↗
PubMed1985

Two isozymes of chicken muscle acylphosphatase: purification and properties.

Two acylphosphatases, named Ch1 and Ch2, have been purified from chicken skeletal muscle. The molecular weights were determined to be 11,900 and 12,000 for Ch1 and Ch2, respectively, by sedimentation equilibrium. In the amino acid compositions of Ch1 and Ch2, two residues of histidine were contained in Ch2, but none in Ch1, and one residue of cysteine was contained in Ch1, but none in Ch2. There were 11 lysines and 6 arginines in Ch1, whereas there were 6 lysines and 11 arginines in Ch2. In addition, the contents of methionine, serine, glutamic acid and glutamine, and alanine were considerably different between Ch1 and Ch2. There were also differences in the peptide maps and carboxyl-terminal amino acid sequences (-Ser-Thr-Arg-Tyr-COOH for Ch1, and -Phe-Thr-Ile-Arg-Lys-COOH for Ch2). In the double immunodiffusion, Ch2 did not form a precipitin line with the rabbit anti-Ch1 antiserum. These results indicate that Ch1 and Ch2 are different, genetically specified isozymes of acylphosphatase of chicken skeletal muscle. Ch2 is considered to be a new type of acylphosphatase from skeletal muscle.

Acid Anhydride Hydrolases↗
PubMed1985

Thyroid-stimulating antibody bioassay using porcine thyroid cells cultured in follicles.

Isolated porcine thyroid cells were cultured in agarose-coated dishes and allowed to reform follicles with normal polarity. The thyroid cells reaggregated into follicles were compared with cells cultured in monolayer for cAMP responsiveness to TSH and thyroid-stimulating antibody (TSAb). The cells in follicles were sensitive to TSH stimulation and responded to the hormone at concentrations as low as 3.3-10 microU/ml with an increase in cAMP production. In contrast, 10-50 microU/ml TSH were required to elicit a cAMP response in cells cultured in monolayer using identical conditions. cAMP responsiveness to TSAb also was greater in the cells organized into follicles. TSAb was detected in serum from 89.4% of 66 untreated patients with hyperthyroid Graves' disease using thyroid follicles, but TSAb was detected in serum from only 60% of the patients when assayed using cells in monolayer. The assay using thyroid follicles was used to measure TSAb in 27 euthyroid patients who were euthyroid while receiving thionamide therapy and compared with 20-min thyroid 131I uptake after T3 suppression. TSAb was present in 11 of 12 nonsuppressible patients and in 5 of 15 suppressible patients. TSAb was positively correlated with 20-min 131I thyroid uptake. We conclude that thyroid cells cultured in follicles are suitable for measuring TSAb.

Adolescent↗
PubMed1985

Triiodothyronine binding immunoglobulin in a euthyroid man without apparent thyroid disease; its properties and effects on triiodothyronine metabolism.

A 54 year old man with markedly elevated serum T3, but without an apparent thyroid disease, was found to have a specific antibody to T3. His serum thyroxine, TBG and TSH were in normal range, but T3-RSU was markedly low. Antibodies to thyroglobulin and microsome were negative. He was judged euthyroid because of a normal basal metabolic rate and a normal thyroidal 123I uptake which was suppressed by T3 administration. When serum was extracted with ethanol prior to assay, serum T3 was found to be in the upper border of normal range. Several experiments revealed the presence of an antibody to T3 in his serum with an affinity constant of 3.3 X 10(9) M-1. The binding capacity of the antibody was 7.6 ng/mg of IgG. The binding of [125I]T3 was almost specific to T3, and potencies of T4 and fT3 in displacing [125I]T3 binding were only 1.0 and 0.3%, respectively, of that of T3. The antibody contained both kappa and lambda chains and was therefore polyclonal. The T3 metabolic clearance rate, which was determined by disappearance of injected [125I]T3 from serum, was lower in this patient (7.44 1/day) than in normal. The T3-production rate was decreased to 14.9 micrograms/day, and serum free T3 concentration as well as urinary T3 excretion rate were also reduced. Since both serum total and free T4 concentrations were normal, the supply of T4 to peripheral tissues would be sufficient to keep this patient in a euthyroid state in spite of the anti-T3 antibody.

Chemical Precipitation↗
PubMed1985

[Studies on implantation traces in rats. I. Size, observation period and staining].

The implantation traces of early embryonal death and abortion in rats induced by some drugs were studied. Early embryonal death and abortion were caused by intraperitoneal injection of 15 mg/kg of busulfan on the 7th day of gestation or 40 mg/kg of 6-mercaptopurine on the 7th and 8th day of gestation. The observation period and staining of the implantation traces were investigated. Early dead embryos and placentas were delivered between the 20th and 24th day of gestation. These were eaten by the dams. The implantation traces of abortion or early embryonal death, and those of normal delivery were able to be identified up to the 120th day and 500th day after extraction, respectively. The implantation traces of abortion were smaller in the three experimental groups. All kinds of implantation traces were stained distinctly with 10% ammonium sulfide, 0.2% sodium hydroxide and 2% potassium ferrocyanide. In this staining method, sodium hydroxide has an excellent effect on the staining of implantation traces. Specimens washed in water after being stained with sodium hydroxide and fixed in formalin can be preserved without discoloration for a long period of time.

Abortion, Spontaneous↗
PubMed1985

A new unstable, high oxygen affinity hemoglobin: Hb Nagoya or beta 97 (FG4) His----Pro.

An unstable hemoglobin was detected by isopropanol and heat precipitation tests in a 49-year-old Japanese man suffering from acute exacerbation of a chronic hemolytic disorder which was apparently triggered by infection of cholelithiasis. One of his two sons carried the same abnormal hemoglobin, and was jaundiced, but otherwise healthy, without anemia. The abnormal hemoglobin focused at a slightly more anodic position than Hb A in thin layer polyacrylamide gel electrofocusing. The abnormal beta chain emerged after normal beta chain in reverse phase high performance liquid chromatography of the hemolysate. It comprised 16.7% and 25.5% of the total beta chain in the propositus and his son, respectively. The partially heme-depleted abnormal beta subunit was precipitated with p-chloromercuribenzoic acid, and the abnormal beta chain was isolated by urea CM-cellulose column chromatography. Structural analysis demonstrated substitution of proline for histidine at position 97 (FG4) in the beta chain. The abnormal hemoglobin was purified by ion-exchange column chromatography. It showed a hyperbolic oxygen equilibrium curve indicating a high oxygen affinity and the absence of cooperative intersubunit interaction. Subunit dissociation seemed to be slightly enhanced. The variant was markedly susceptible to oxidation and rapidly lost heme upon oxidation.

Amino Acid Sequence↗
PubMed1985

[Studies on implantation traces in rats. II. Staining of cleared uteri, formation and distribution of implantation traces].

We made an investigation of implantation traces in delivered rats. 1. Non-fixed rat uteri were immersed in 2%-NaOH solution for over one hour. The uteri were then cleared and the implantation traces were seen to be stained yellowish-brown. This staining method was convenient for observation of the implantation traces. 2. Stillbirth was induced by stabbing or crushing, either in some embryos on one day between the 6th and 12th day of gestation, or in all embryos after the 13th day of gestation. Also, abortion was induced by stabbing or crushing all embryos before the 10th day of gestation. 3. When live embryos existed in the uterine horns, abortion traces were not detected. 4. In cleared uteri stained with 2%-NaOH solution, abortion traces were observed as small globes, reddish-brown. Normal delivery traces were observed as large globes, yellowish-brown, covered with yellowish-white of agglomerate cells, while stillbirth traces appeared as middle-sized, orange or yellowish-brown masses. 5. Though the implantation traces in rats which had been delivered four times were arranged like beads, they were recognizable by NaOH stain as either old or new traces, the former appearing smaller without agglomerate cells and a little more brown in comparison with the latter. 6. As the implantation traces increased in the uterine horns they became distributed from the central region to the cervical end, and the mean space between them narrowed. The implantation traces occupying the ovarian end or central region of the uterine horns trendes smallest size or largest size. 7. The implantation traces were composed of cicatrical tissue, and the area they occupied did not show adhesion of the placenta. On the other hand, placenta adhering to the uterine wall proliferated, and formed new implantation traces which did not overlap the old traces after decollement of the placenta.

Abortion, Induced↗