False negative results of anticardiolipin antibody test.
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Adult↗
Biomedical subjects
S Hirose
Publications and source records attributed to S Hirose.
A dramatic pH-dependent alteration in ANP receptor density: a note for using cultured cells.
Culture media tend to become acidic when rapidly growing cells are cultured under batch conditions using a CO2/HCO3- buffer system. The effects of this inherent lowering of pH on cellular makeup of cultured cells, which have long been ignored, were examined by monitoring the pH and number of the atrial natriuretic peptide (ANP) receptors expressed on the cultured bovine endothelial cells. The Eagle's minimum essential medium was adjusted to three different pH values of 7.0, 7.4, and 7.7 and used for 48-h batch cultures. After this 48-h incubation, the pH values of the media were found to be 7.0, 7.1, and 7.4, respectively. These pH shifts had unexpectedly strong influences on the ANP receptor levels without affecting the affinity. Cells maintained in the slightly higher pH medium had a trace amount of the receptor (< 10 sites/cell), while those in the lower pH environment exhibited a large number of binding sites (40,000 sites/cell). Similar situations might occur in other cellular components and in other types of cells, and therefore, such possibilities should be kept in mind when cultured cell systems are used.
1-Methyl-3-isobutylxanthine↗
Immunochemical characterization and localization of endothelin ETB receptor.
A highly specific antiserum was raised against purified bovine endothelin ETB receptor and used to determine the tissue distribution of the receptor subtype ETB and to localize the receptor immunohistochemically in the kidney, adrenal gland, lung, cerebellum, and pituitary gland whose functions are known to be under strong influence of endothelin. The antiserum raised in a rabbit specifically recognized the receptor band on Western blot analysis of membrane proteins. Furthermore, it immunoprecipitated only ETB, establishing its ETB specificity. By determination of the percentage of the total number of the endothelin receptors that is immunoprecipitable with the antiserum, the amounts of the ETB relative to those of the ET receptors were found to vary from tissue to tissue: lung (70%), cerebellum (55%), pituitary gland (50%), kidney (25%), adrenal gland (10%), and testis (< 2%). This means that, in the lung, ET is the major form, whereas in the testis, ETA is predominant, comprising >95% of the receptors. Immunohistochemical examination of tissue sections revealed endothelium localization of the ETB endothelin receptor.
Adrenal Glands↗
High-density localization of ANP receptors in chondrocytes of eel gill cartilage.
Very high levels of atrial natriuretic peptide (ANP) receptor were found in a quite unexpected tissue, i.e., the chondrocyte of the eel gill cartilage. 125I-labeled ANP binding assay indicated that the eel gill contains large amounts of the receptor and its levels are much higher (> 10-fold) than those in the other tissues examined, including the brain, kidney, head kidney including steroidogenic interrenal cells, and gut. Autoradiography using gill sections revealed dense localization of ANP receptors in the chondrocytes of the cartilage as well as moderate localization in the parenchymal cells. Biochemical and pharmacological characterization of the chondrocyte receptor indicated that most of the receptors are type C receptors, having a broad ligand specificity and a reduced M(r) of 68,000. Because a hyaline cartilage in which chondrocytes reside lacks blood vessels, and all metabolic exchange is by slow diffusion through the matrix, the chondrocyte localization of the type C ANP receptor is notable and may stimulate not only chondrocyte research but also studies on physiological significance of the type C receptor, which is generally considered to be merely a clearance (silent) receptor.
Animals↗
Control of imaginal cell development by the escargot gene of Drosophila.
Mutations in the escargot (esg) locus, which codes for a zinc-finger-containing protein with similarity to the product of the snail gene, cause a variety of defects in adult structures such as loss of abdominal cuticle and malformation of the wings and legs. esg RNA is expressed in wing, haltere, leg and genital imaginal discs and in abdominal histoblast nests in the embryo. Expression in imaginal tissues is also found in third instar larvae. In esg mutant larvae, normally diploid abdominal histoblasts replicate their DNA without cell division and become similar in appearance to the polytene larval epidermal cells. A similar phenotype was also found in imaginal discs of larvae mutant for both esg and the Drosophila raf gene. These results suggest that one of the normal functions of esg may be the maintenance of diploidy in imaginal cells.
Abdomen↗
Disseminated intravascular coagulation in a patient with systemic lupus erythematosus with lupus anticoagulant.
A 19-year-old female patient with systemic lupus erythematosus (SLE) who had lupus anticoagulant (LA) and concurrently developed disseminated intravascular coagulation (DIC) during an exacerbation of "central nervous system (CNS) lupus". Since no other indications or causes for DIC could be demonstrated, she was treated with prednisolone and anticoagulants, which rapidly alleviated her DIC condition as well as "CNS lupus". Although abnormalities of coagulation are frequently reported in SLE patients, DIC rarely occurs in patients with SLE without associated complications. A review of the pathogenesis of DIC in patients with SLE is discussed.
Adolescent↗
Differential sensitivity to interleukins of CD5+ and CD5- anti-DNA antibody-producing B cells in murine lupus.
We studied the effects of interleukins (IL) on in vitro IgM and IgG anti-DNA antibody production by splenic B cells from autoimmune disease-prone NZBxNZW (NZB/W) F1 mice. It was found that different interleukins regulate phenotypically distinct B cells producing separate isotype of anti-DNA antibodies. IL-2 slightly but significantly inhibited the production of IgM anti-DNA antibodies. IL-4 and IL-6 significantly enhanced the antibody production, but the effects were not so marked and inconsistent, particularly with respect to IL-6. By contrast, the effects of IL-5 were remarkable, particularly on splenic B cells from young mice. As for IgG anti-DNA antibodies, IL-6, but not other interleukins, markedly up-regulated the antibody production by splenic B cells from mice over 6 months of age, in a dose dependent fashion. Thus, the ability of B cells to produce IgG anti-DNA antibodies appears to be dependent on the surface expression of IL-6 receptor (IL-6R) at the ages when the mice begin to develop the disease. Studies of the surface phenotypes showed that while the IL-5-sensitive major IgM anti-DNA producers were CD5+Lp-3(CD43)-sIgM+, the IL-6-sensitive major IgG anti-DNA producers were CD5-Lp-3+sIgM-. However, significant amounts of IgG antibodies were also produced, in the presence of IL-6, by CD5+Lp-3+sIgM+, but not by CD5-Lp-3+sIgM+ B cells from 6-month-old mice. We suggest that surface phenotypes of anti-DNA antibody producers change from CD5+Lp-3-sIgM+IL-5R+, CD5+Lp-3+sIgM+IL-6R+ and subsequently to CD5-Lp-3+sIgM-(sIgG+)IL-6R+ in NZB/W F1 mice with aging.
Animals↗
Reactive arthritis induced by Vibrio parahaemolyticus.
We describe a case of reactive arthritis after Vibrio parahaemolyticus infection. V. parahaemolyticus is the principal bacteria involved in the causation of foodborne gastroenterocolitis outbreaks in Japan. Several bacteria have been recognized as being involved in the development of reactive arthritis and this is the first report of reactive arthritis induced by V. parahaemolyticus.
Adult↗
HLA-DP positive T cells in patients with polymyositis/dermatomyositis.
The examination of HLA-DP+ T cells in 21 patients with polymyositis/dermatomyositis revealed marked increases [28.5% (SD 16.6%)], compared with the HLA-DQ+ and DR+ T cells. The HLA-DP molecule was expressed on both CD4+ and CD8+ T cells. The majority of HLA-DP+ CD8+ cells were cytotoxic T cells. There was no significant correlation between the proportion of HLA-DP+ T cells and the level of myogenic enzyme, although a decrease in HLA-DP+ T cells after therapy was accompanied by a decrease in myogenic enzymes. However, the proportion of HLA-DP+ CD8+ cells was significantly higher in those patients with active pneumonitis.
Adult↗
[Participation of non-major histocompatibility complex gene in experimental autoimmune uveitis].
It is known that the susceptibility of experimental autoimmune uveitis (EAU) is controlled by both major histocompatibility antigen complex (MHC) and non-MHC genes. In this report, we studied the role of non-MHC gene in the induction of EAU. LEW, WKAH, (LEW x WKAH) F1 and (LEW x WKAH) F2 rats were examined for their incidence and severity to develop EAU by immunization with bovine S-antigen (S-Ag). We found that all LEW rats developed severe EAU within 2 weeks after immunization, but no WKAH rat did. Most F1 rats developed mild inflammation in 3-4 weeks after immunization. A quarter of F2 rats developed EAU within 2 weeks, half of them developed it in 3-6 weeks after immunization, and the others did not. These findings suggest that only one non-MHC gene controls the susceptibility to S-Ag induced EAU in rats.
Animals↗
Changes of DNA methylation in protooncogenes in the process of radiation-induced transformation of mouse m5S/1M cells in vitro.
To assess the importance of changes in DNA methylation in an X-ray-induced cellular transformation process, methylation patterns of five nuclear protooncogenes in fifteen transformant clones were studied and compared to that of the parental non-transformed cell line m5S/1M. All transformants examined revealed an alteration in DNA methylation in some of the genes, although these changes were variable among them. A comparison of cellular characteristics with corresponding DNA methylation changes in different clones suggested that the loss of contact inhibition and the gain of anchorage independency were associated with increases of methylation in many genes, whereas the acquisition of tumorigenicity was often accompanied by a decrease of methylation in the N-myc and c-myc genes. Resultant data indicate that the alteration of DNA methylation is closely related to transformation process, yet how this involvement occurs is complex and remains unclear.
Animals↗
Affected paroxysmal nocturnal hemoglobinuria T lymphocytes harbor a common defect in assembly of N-acetyl-D-glucosamine inositol phospholipid corresponding to that in class A Thy-1- murine lymphoma mutants.
Deficient expression of glycoinositol phospholipid (GPI) anchored proteins in affected paroxysmal nocturnal hemoglobinuria (PNH) cells has been traced to a defect in GPI anchor assembly. In a previous study (Schubert, J., Schmidt, R. E., and Medof, M. E. (1993) J. Biol. Chem., in press) we characterized the biosynthesis of putative Man-containing GPI anchor precursors in normal peripheral blood lymphocytes and investigated assembly of these intracellular GPI intermediates in CD48- affected and CD48+ unaffected T and natural killer cell lines of PNH patients. We found that affected T cells from five patients exhibited a uniform defect in which dolichol-phosphoryl-Man was synthesized but no GPI mannolipids were expressed. In this study, membranes of patients' affected T cells were labeled with UDP-[3H]GlcNAc to evaluate earlier steps in GPI synthesis, and intact cells were fused to Thy-1- murine lymphoma mutants harboring different defects in early GPI assembly to test for the presence of corresponding or complementary lesions. In all cases, affected cell membranes failed to assemble GlcNAc-inositol phospholipid, the initial precursor of GPI anchor structures, and the intact cells failed to complement class A mutants while complementing other classes. Affected polymorphonuclear leukocytes from three additional patients of different origin were then labeled with [3H]Man and the labeling patterns found to correspond to those obtained with the T lymphocytes. Taken together the data indicate that the genetic lesion in PNH cells resides in a DNA element which: 1) encodes a product required for the synthesis of GlcNAc-inositol phospholipid, 2) corresponds to that altered in class A Thy-1- murine lymphoma mutants, and 3) is commonly affected in different patients.
Acetylglucosamine↗
Structure of the bovine ETB endothelin receptor gene.
The structure of the gene encoding the bovine type B endothelin receptor (ETB) has been established and compared with those of other heptahelical receptors. The gene is present as a single copy in the bovine genome, as demonstrated by Southern blot analysis, and spans at least 36 kb. The coding region is divided into 7 exons separated by 6 introns, one of which is more than 23 kb in length. The exons correspond well to the structural domains of the receptor: the first exon encodes the first and second transmembrane domains, and each of the following transmembrane domains is encoded by a separate exon. The portion of the ETB protein sequence encoded by exon 3 is quite different from the corresponding ETA sequence, suggesting that this region is responsible for the distinct ligand specificities of the two receptor subtypes. The second intron interrupts the canonical Asp-Arg-Tyr sequence, which is located at the end of the third transmembrane domain of the heptahelical receptors, as with the substance P, substance K, dopamine D2 and dopamine D3 receptor genes. To map the 5' region of the gene and determine the start of transcription, primer-extended cDNAs were cloned and sequenced: multiple start sites were deduced with no apparent TATA box in the expected upstream region. Similar results were obtained by ribonuclease protection analysis.
Animals↗
Serum cardiac troponin T in polymyositis/dermatomyositis.
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Dermatomyositis↗
Molecular cloning of porcine soluble angiotensin-binding protein.
Soluble angiotensin-binding protein (sABP) is a 75-kDa cytosolic protein that binds angiotensins and its analogues with high affinity. In this study, the primary structure of porcine sABP is determined by cDNA cloning. Based on the partial amino acid sequences of sABP tryptic fragments, fully degenerate oligonucleotides were synthesized, and used as primers for polymerase chain reactions to amplify the corresponding sABP cDNA fragment from porcine liver first-strand cDNA. By using initially the polymerase chain reaction product and later partial cDNA clones as probes, porcine heart and liver cDNA libraries were screened, and several positive clones were obtained including one covering the entire coding region. From the cDNA sequence, an open reading frame that encodes sABP as a 704-amino acid protein with molecular mass of 80,800 daltons is predicted. No significant homology was seen between sABP and other proteins in GenBank and NBRF data bases, including the angiotensin-related proteins such as angiotensin converting enzyme, renin, and AT1 angiotensin II receptor. Northern blot analysis of poly(A)+ RNA revealed that the mRNA for sABP is expressed as 5.3- and 2.8-3.2-kilobase transcripts. These transcripts are generated by the use of alternative polyadenylation signals. Within the 3'-untranslated region of the cDNA sequence downstream from the polyadenylation signals for smaller transcripts, a porcine short interspersed repetitive element (SINE) was found; only the longer 5.3-kilobase transcript had the SINE sequence.
Amino Acid Sequence↗
Cell cycle-dependent changes in tissue transglutaminase mRNA levels in bovine endothelial cells.
The pattern of transglutaminase gene expression through the cell cycle was examined by Northern blot analysis using cultured bovine endothelial cells and a cDNA probe. When the cells reached confluency or were arrested in G0/G1 phase by nutrition deprivation, transglutaminase mRNA rose to a very high level; S- and M-phase extracts showed high and low levels, respectively. Subcellular localization studies by sucrose gradient centrifugation and immunostaining demonstrated that the majority of transglutaminase is present in cytosols throughout the cycle. The cell cycle-dependent changes in the transglutaminase mRNA levels strongly support the implicated involvement of the enzyme in cell growth, differentiation, and senescence.
Animals↗
Characterization of putative glycoinositol phospholipid anchor precursors in mammalian cells. Localization of phosphoethanolamine.
A number of mammalian cell surface proteins are anchored by glycoinositol phospholipid (GPI) structures that are preassembled and transferred to them in the endoplasmic reticulum. The GPIs in these proteins contain linear ethanolamine (EthN)-phosphate (P)-6ManManManGlcN core glycan sequences bearing an additional EthN-P attached to the Man residue (Man 1) proximal to GlcN. The biochemical precursors of mammalian GPI anchor structures are incompletely characterized. In this study, putative [3H]Man-labeled GPI precursors were obtained by in vitro GDP-[3H] Man labeling of HeLa cell microsomes and by in vivo [3H]Man labeling of class B and F Thy-1 negative murine lymphoma mutants known to accumulate incomplete GPIs. The high performance liquid chromatography-purified in vitro and accumulated in vivo GPI products were structurally analyzed by nitrous acid deamination, hydrofluoric acid, trifluoroacetic acid hydrolysis, biosynthetic labeling, and exoglycosidase treatment. The data were consistent with a biosynthetic scheme in which Man and EthN-P are added stepwise to the developing glycan. Several additional points were demonstrated: 1) putative mammalian GPI precursors contain incomplete core glycans corresponding to those in previously characterized trypanosome GPI precursors. 2) The proximal EthN-P found in mature mammalian GPI anchor structures is added to Man 1 prior to incorporation of Man 2 and Man 3. 3) Glycans in the incomplete GPIs that accumulate in classes B and F lymphoma mutants consist of Man2- and Man3GlcN in which EthN-P is linked to Man 1. 4) Distal EthN-P linked to the 6-position of Man, characteristic of the complete GPI core, is found both in a subsequent GPI species with the glycan sequence EthN-P-6ManMan(EthN-P----)ManGlcN and in a more polar GPI product.
Animals↗
DNA supercoiling facilitates the assembly of transcriptionally active chromatin on the adenovirus major late promoter.
Assembly of nucleosomes on the adenovirus major late promoter blocked initiation of transcription by RNA polymerase II. However, the formation of transcription preinitiation complexes prevented subsequent assembly of promoter sequences into nucleosomes and allowed transcription on the chromatin templates. When the formation of preinitiation complexes was in competition with nucleosome assembly, transcription on linear or relaxed closed circular DNA was inactivated by nucleosome assembly over the promoter region. However, transcription on partially supercoiled DNA (mean superhelical density of -0.036) remained active because the rapid formation of preinitiation complexes prevented subsequent assembly of promoter sequences into nucleosomes.
Adenoviridae↗