Biomedical subjects

Y Ohba

Publications and source records attributed to Y Ohba.

At least 109 records · Page 6Linked to original sources

PubMed1996

Major histocompatibility complex expression in muscle of rats with graft-versus-host disease.

Immunohistochemical examination of rat skeletal muscle during graft-versus-host disease (GVHD), a systemic immune reaction, was performed to investigate specific immune reactivities focusing on major histocompatibility complex (MHC) expression and inflammatory cell infiltration of skeletal muscle during a systemic immune reaction. MHC class II expression and inflammatory cell infiltration did not increase. MHC class I was expressed along the contour of muscle fibres, and most strongly expressed by the cells which were distributed throughout the endomysium and perimysium. Seventy-six percent of these MHC class I+ cells carried endothelial cell-markers, while 24% of them did not. The latter cells were revealed not to be inflammatory cells such as lymphocytes, granulocytes or macrophages when examined by immunostaining using several exudate-cell markers. Neither were they myosatellite cells because they were located outside the basement membrane. These results may be useful for considering animal models of inflammatory myopathies such as polymyositis and dermatomyositis.

Animals↗

PubMed1996

[A case of leiomyomatosis in pelvic lymph nodes].

We report a rare case of leiomyomatosis in iliac lymph nodes, which was found in a woman operated with a diagnosis as keratinizing epidermoid carcinoma of the cervix. A 39-year-old Japanese female, married, who had received hormonal therapy in her past history, visited the Department of Obstetrics and Gynecology at Kinki University Hospital, with a chief complaint of bloody discharge. Colposcopy and biopsy suggested a diagnosis of keratinizing epidermoid carcinoma of the cervix. A radical hysterectomy and bilateral salpingo-oophorectomy with pelvic lymph nodes dissection was performed. Histopathological examination showed a keratinizing epidermoid carcinoma of the cervix. An intramural leiomyoma nodule (0.5cm in diameter) was detected in the fundus of the uterus. Histopathologically, this was a typical benign leiomyoma. The lymph nodes were free of neoplasms. But bilateral iliac lymph nodes were enlarged up to soybean size. Microscopically, the iliac lymph nodes contained a large amount of well differentiated smooth muscle tissue (11/30). Immunohistochemical investigation showed a positive reaction for smooth muscle actin and desmins in the spindle cells proliferated in the lymph nodes; no cytokeratin positivity was detected. Leiomyomatosis of lymph node may rise through metaplasia of intranodal decidua or endometriosis by myofibroblasts or smooth muscle cells, reflecting the multipotentiality of the pelvic subcoelomic mesenchyme that can be found in the peripheral sinus of lymph nodes.

Adenocarcinoma, Papillary↗

PubMed1996

[Homozygous beta(+)-thalassemia due to -31 A to G mutation].

A 20-year-old Japanese woman was admitted to our hospital with anemia and mild splenomegaly. Peripheral blood examination revealed Hb 9.4 g/dl, Ht 29.3%, RBC 4.74 x 10(6)/microliters, reticulocytes 2.4%, WBC 5,200/microliters, platelets 24.9 x 10(4)/microliters, MCV 61.7 fl, and MCH 19.9 pg. Poikilocytosis with target cells was recognized on the peripheral blood smear. A bone marrow aspirate revealed erythroid hyperplasia. Serum iron and ferritin were in the normal range. beta-thalassemia was suggested by the increase in HbA2 (6.5%) and HbF (7.5%). Analysis of beta globin DNA by single strand conformation polymorphism (SSCP) and amplification refractory mutation system (ARMS) confirmed a diagnosis of homozygous beta(+)-thalassemia due to -31 A to G mutation. A familial study revealed that her parents were heterozygous for this allele. This is the 8th case of homozygous beta(+)-thalassemia due to -31 A to G mutation in Japan.

Adult↗

PubMed1996

[Mechanisms for the enhanced red cell destruction in hemoglobinopathy].

The process of denaturation of Hb within red cells, leading to ultimate formation of Heinz body or aggregates of irreversibly denatured Hb, was formulated over 20 years ago. The mechanical obstruction due to Heinz bodies seems self-evident as a cause of enhanced red cell destruction. Recent studies compare the overall defects in rheologic properties of red cells of unstable Hb disorder with artificially oxidized red cells. The fate of superoxide anion which is the other product of oxidative denaturation of Hb is being discussed in the light of accumulation of oxidative damage to red cell membrane. From this aspect, unstable Hb disorder may be regarded as a model of accelerated red cell aging. The aged red cells appear to bind increased amounts of immunoglobulin. They may express scavenger ligands. The rheologic defects and altered surface phenomena would be additive in enhancing red cell phagocytosis. The chemical basis for the abnormal properties of unstable Hb red cells, as well as normal senescent red cells, is yet to be defined.

Erythrocytes↗

PubMed1996

[Hb, C, D and E hemoglobinopathies].

The four commonest beta chain variants of human hemoglobin (Hb), i.e. Hbs C, D, E, and S were absent or quite infrequent in Japanese. They are occasionally found in visitors and immigrants to Japan recently. Geographical distribution, clinical expression, pathophysiology and diagnosis of Hbs C, D and E are briefly reviewed.

Hemoglobin C Disease↗

PubMed1996

[Future prospects of emergency laboratory tests--problems of immunoserologic tests].

Regarding problems in emergency and urgent immunoserologic tests, I mainly focused on infectious diseases and CPR and discussed the correspondence of dangerous needle stick injuries, and the significance of emergency CRP measurement in various body fluids using highly sensitive determination methods. The actual conditions and correspondence of infections due to dangerous needle stick injuries (accidental pricking with used needles) such as hepatitis, syphilis, acquired immunodeficiency syndrome (AIDS), adult T-cell leukemia (ATL), herpes simplex, falciparum malaria, tuberculosis, Rocky mountain spotted fever, and human colonic adenocarcinoma are discussed. With regard to emergency CRP measurement, application of highly sensitive determination methods and the significance of CRP measurement of various body fluids (healthy adult blood, cord blood, cerebrospinal fluid, urine and puncture fluid) are described. The reference values for CRP concentrations in various body fluids were established at 15 to 3,063 ng/ml for serum (male; 26 to 3.992 ng/ml, female; 11 to 1,672 ng/ml), 9 to 73 ng/ml for cord blood, 2 to 10 ng/ml for cerebrospinal fluid and less than 2 ng/ml for urine.

Accidents, Occupational↗

PubMed1995

Pyruvate kinase deficiency of mice associated with nonspherocytic hemolytic anemia and cure of the anemia by marrow transplantation without host irradiation.

Mutant mice with splenomegaly and nonspherocytic hemolytic anemia were found in an inbred colony of the CBA/N (hereafter CBA) strain maintained in the Japan SLC Haruno farm (Shuchi-gun, Shizuoka, Japan). The activity of pyruvate kinase (PK) in red blood cells (RBCs) of the anemic mutants decreased to 16.2% of normal (+/+) CBA mice. Because the mutant CBA mice showed a remarkable reticulocytosis (41.6%) and because the PK activity of reticulocytes is much higher than that of mature RBCs, the PK activity in mature RBCs of the mutant CBA mice was calculated to be 2.8% that of mature RBCs of CBA-(+/+) mice. Because RBC type PK is encoded by the Pk-1 locus of the mouse (chromosome 3), we designated the mutant locus as Pk-1slc. The anemia and PK deficiency of CBA-Pk-1slc/Pk-1slc mice were cured by bone marrow transplantation (BMT) from CBA-(+/+) mice. Prior irradiation was not necessary for the curative BMT. On the other hand, the BMT from CBA-Pk-1slc/Pk-1slc mice to nonirradiated CBA-(+/+) mice did not result in the decrease of RBCs and the reduction of PK activity. The present results indicate that CBA-Pk-1slc/Pk-1slc mice are a potentially useful animal model for studying pathophysiology of PK deficiency and for developing new therapeutic methods to correct PK deficiency.

Anemia, Hemolytic, Congenital Nonspherocytic↗

PubMed1995

Purification of an angiogenesis inhibitor from culture medium conditioned by a human chondrosarcoma-derived chondrocytic cell line, HCS-2/8.

We previously reported that a novel human chondrosarcoma-derived chondrocytic cell line, HCS-2/8, produced an anti-tumor angiogenesis factor and secreted it into the culture medium [Takigawa et al.: Anticancer Res., 10, 311-316, 1990]. In the present study, we purified the inhibitor by monitoring gelatinase inhibitory activity from the conditioned medium (CM) of HCS-2/8 cells. By a simple three-step procedure, gel filtration chromatography, ion-exchange chromtography, and reverse-phase HPLC, 200 micrograms of the inhibitor was obtained from 6 liters of CM with 239-fold enrichment. Purified inhibitor, named hCHIAMP (human chondrocyte-derived inhibitor of angiogenesis and metalloproteinase activity), showed a single protein band with a molecular mass (M(r)) of 24,000 (24K) under reducing conditions and M(r) 22K under nonreducing conditions on SDS-PAGE. On reverse-zymography, purified hCHIAMP showed a single band of 22K M(r) under nonreducing conditions. Its NH2-terminal amino acid sequence determined up to the 11th amino acid residue was identical with that of the tissue inhibitor of metalloproteinases-2 (TIMP-2). On Western blotting, anti-human TIMP-2 antibody cross-reacted with hCHIAMP, hCHIAMP at a dose of as little as 0.45 microgram significantly inhibited angiogenesis in the yolk sac of chick embryos induced by 0.25 mumol of spermine. Because HCS-2/8 is a clonal cell line, these findings clearly showed for the first time that chondrocytes themselves produce a potent inhibitor of angiogenesis, which is also an inhibitor of gelatinase. The findings also indicate that hCHIAMP is a TIMP-2-like molecule. Because the HCS-2/8 cells are an immortal cell line and of human origin, hCHIAMP could be useful for therapy of angiogenic diseases including solid tumors.

Chondrosarcoma↗

PubMed1995

Secretion and processing mechanisms of procathepsin L in bone resorption.

Secretion of procathepsin L into the culture medium from a bone cell mixture was markedly enhanced by addition of parathyroid hormone (PTH), 1 alpha,25-(OH)2D3 or tumor necrosis factor alpha (TNF alpha). These stimulators of secretion of procathepsin L enhanced bone pit formation, which was inhibited by E-64, but not by CA-074, a specific inhibitor of cathepsin B. Procathepsin L may thus participate in the process of bone collagenolysis during bone resorption. Procathepsin L partially purified from rat long bones under cold conditions was rapidly converted to the mature form under acidic conditions at room temperature. This conversion was inhibited by E-64, suggesting that the procathepsin L secreted into lacunae is catalytically converted to the mature enzyme by cysteine proteinase(s).

Animals↗

PubMed1995

Transcription stimulation of the Fas-encoding gene by nuclear factor for interleukin-6 expression upon influenza virus infection.

We previously found that the level of Fas, a cell surface receptor for an apoptosis signal, increases at the mRNA level in influenza virus-infected HeLa cells prior to their death by apoptosis. Here we investigated the mechanism of activation of the Fas-encoding gene expression upon influenza virus infection. Nucleotide sequences for the binding of nuclear factor for interleukin-6 expression (NF-IL6), also known as CCAAT/enhancer-binding protein beta, were repeated 8 times in the 5'-end region of the human FAS gene, spanning from -1360 to +320. This region directed the expression of a downstream marker gene when introduced into HeLa cells and the activity of the FAS gene promoter was stimulated about 2-fold upon influenza virus infection. Gene expression driven by the FAS promoter was activated when human NF-IL6 was overproduced in a DNA when human NF-IL6 was overproduced in a DNA co-transfection study. Moreover, the DNA-binding activity of NF-IL6 increased after infection with the virus, whereas the amount of NF-IL6 seemed unchanged. The results suggest that NF-IL6 is activated upon influenza virus infection through post-translational modification and that the modified factor stimulates the transcription of the human FAS gene.

Antigens, Surface↗

PubMed1995

Ultraviolet resonance Raman studies of quaternary structure of hemoglobin using a tryptophan beta 37 mutant.

Environmental changes of tyrosine and tryptophan residues of hemoglobin (Hb) upon its T to R transition of quaternary structure were investigated with ultraviolet resonance Raman (UVRR) spectroscopy excited at 235 nm. DeoxyHb A (T-form) showed a UVRR spectrum distinctly different from those of the ligated Hbs (R-form) including oxyHb, COHb, and metHb A, whereas the ligated Hbs exhibited similar UVRR spectra irrespective of the ligand species and the oxidation state of the heme. To characterize the spectral change of Trp-beta 37 at the alpha 1 beta 2 interface due to the quaternary structure transition, the UVRR spectra of Hb A were compared with the corresponding spectra of Hb Hirose (Trp-beta 37-->Ser). A difference spectrum between deoxyHb A and deoxyHb Hirose showed only Trp resonance Raman (RR) bands, which were reasonably ascribed to Trp-beta 37 in deoxyHb A. RR bands at 873 cm-1 (W17) and at 1360 and 1343 cm-1 (W7, Fermi doublet) indicated that the indole ring of Trp-beta 37 in deoxyHb A formed a strong hydrogen bond at the N1H site in hydrophobic environments. Tyr residues in deoxyHb Hirose seemed to be in the same environments as those of deoxyHb A. In contrast, the difference spectrum between Hb A and Hb Hirose in the ligated state displayed peaks for RR bands of both Trp and Tyr. The difference spectra were unaltered by the addition of 5 mM inositol hexaphosphate. This means that the differences were not caused by the tetramer to dimer dissociation but by a conformation change within a tetramer. Comparison of the Hb A-Hb Hirose difference spectra in the oxy and deoxy states revealed that the oxygenation-induced changes of Trp RR bands arose mostly from Trp-beta 37 with the small portion of remaining changes coming from Trp-beta 15, demonstrating that Trp-beta 37 plays a pivotal role in the quaternary structural change in Hb A.

Amino Acid Sequence↗

PubMed1995

Multi-enzyme reference material from established human cell lines and human sources.

A multi-enzyme reference material was prepared from seven enzymes of asparatate aminotransferase (AST, EC 2.6.1.1), alanine aminotransferase (ALT, EC 2.6.1.2), alkaline phosphatase (ALP, EC 3.1.3.1), lactate dehydrogenase (LD, EC 1.1.1.27), creatine kinase (CK, EC 2.7.2.2), gamma-glutamyltranspeptidase (gamma-GT, EC 2.3.2.2) and amylase (AMY, EC 3.2.1.1) which were purified from human sources including established human cell lines. The enzymatic properties of the material closely resembled those of human serum. In lyophilized form the preparation was stable for at least 200 days when stored at 40 degrees C. Intermethod comparisons of the enzyme activities in 80 clinical specimens were done by correcting the mean values with calibration constants for different assay methods resulting from use of a human serum, the multi-enzyme reference and a commercial control serum. The results from the comparison for the six enzymes of AST, ALT, LD, CK, gamma-GT and AMY in use of the multi-enzyme reference were almost the same as those with use of a human serum as a calibrator, but were not satisfactory for ALP. Even though further search for more reliable material for ALP is required the multi-enzyme reference material can be used for standardization in clinical chemistry.

Alanine Transaminase↗

PubMed1995

Mouse p87wee1 kinase is regulated by M-phase specific phosphorylation.

We have cloned a mouse wee1 kinase cDNA (mwee1). The clone is 2258 bp in length and its open reading frame corresponds to 646 amino acid residues. The molecular weight of this kinase is 87 kDa in SDS-PAGE, which is about 1.7-fold larger than the human p50wee1 kinase reported previously. In a cell cycle, the mouse wee1 kinase is phosphorylated at M-phase, and an in vitro study using a mitotic extract revealed that phosphorylation occurs in the N-terminal domain, which is absent from the human wee1 kinase, resulting in inactivation of the kinase activity. The N-terminal domain or entire molecule is extensively phosphorylated by cdc2-cyclin B kinase. Furthermore, the activity of the wee1 kinase was reduced by phosphorylation with the mitotic extract which contained cdc2-cyclin B kinase.

Amino Acid Sequence↗

PubMed1995

Immunohistochemical localization and biological significance of the phylogenically conserved thymus-brain antigen (UB-13 antigen) in skate, rat and human.

A monoclonal antibody (UB-13) originally raised against the brain of the skate (Raja kenojei, a cartilaginous-fish) was found to react with lymphoid and brain tissues from many species when examined immunohistochemically. In rat and human thymus, UB-13 antigen was observed to be closely associated with reticular tissue in the medulla and cortex. Interestingly, a few or several thymocytes were encircled by the UB-13-reactive reticular tissue. At 14 days gestation, rat thymus consisted mainly of reticular epithelial tissue, after which strong thymocyte production started. At this stage, some of the reticular tissue was heavily stained with UB-13. In the thymus tissues of the irradiated and recovering rats, where reduction and massive reproduction of thymocytes were observed, extensive UB-13 antigen expression localized on the reticular epithelial tissue, an observation which may support the thymocyte re-population. These findings suggest that the antigen recognized by UB-13 may be important for thymocyte proliferation and maturation. UB-13 antigen was found in the fibrous structure of the molecular and granular layer of the human cerebellum. Some glial cells were also stained strongly with UB-13 in the human cerebellar or cerebral grey and white matter. In rat, glial cells, especially astroglias, and the endothelial structure of blood vessels were stained strongly with UB-13. These findings suggest that UB-13 may be a useful monoclonal antibody for analysis of brain-lymphoid antigen in many species.

Adult↗

PubMed1995