Preferred equilibrium structures of a smectic-A phase grown from an isotropic phase: Origin of focal conic domains.
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Journal Article↗
Biomedical subjects
M Okuda
Publications and source records attributed to M Okuda.
Lymphocyte subsets of the nasal mucosa in perennial allergic rhinitis.
T cells have been considered to play a primary role in IgE-mediated atopic diseases, yet little is known about the T-cell subsets in the nasal mucosa of patients with perennial allergic rhinitis. To elucidate the characteristics of T cells at the site of allergic inflammation, we analyzed the proportions, phenotypes, stages of differentiation, and distribution of T-cell subsets in the nasal mucosa of 15 patients with house-dust-mite perennial allergic rhinitis (PAR) and 14 patients with chronic infective rhinitis (CIR), using flow cytometry and immunohistochemistry. We also examined the T-cell subsets in the peripheral blood (PBL) in conjunction with those of the nasal mucosa in 10 patients with PAR and in nine patients with CIR. Our results revealed no obvious difference in the percentage of nasal CD3+ T cells, CD8+ T cells, and alpha beta T cells in the PAR and CIR patients. In contrast, CD4+ T cells (p < 0.05), CD3+4-8- double-negative T cells, (p < 0.01), and gamma delta T cells (p < 0.01) were significantly increased in the nasal mucosa of PAR patients. A majority of the CD4+ T cells in the nasal mucosa of PAR patients coexpressed the CD45RO surface molecule, and a predominant proportion of CD4+ T cells in the nasal coexpressed the CD45RO surface molecule, and a predominant proportion of CD4+ T cells in the nasal epithelium were CD45RO+. The ratio of CD4+ CD45RO+:CD4+ CD45RA+ T cells in the allergic patients' nasal mucosa was significantly greater than that in autologous peripheral blood (p < 0.01). The proportion and stages of activation and differentiation of T-cell subsets in the allergic patients' nasal mucosa were independent of those in the peripheral blood. An increase in the proportion of natural killer (NK) cells was observed in the nasal mucosa of CIR patients. Taken together, our results suggest that nasal T cells exhibit distinct patterns of distribution, differentiation, and activation in different inflammatory conditions of the nose. PAR is characterized by a selective increase in CD4+ memory T cells, CD3+4-8- double-negative T cells, B cells, and gamma delta T cells in the nasal mucosa. The increase in CD4+ memory T cells in the allergic nasal epithelium may have critical implications in the pathogenesis of PAR.
Adult↗
Interleukin-13 expression in the nasal mucosa of perennial allergic rhinitis.
Allergic rhinitis is an IgE mediated atopic disease characterized by elevated levels of allergen specific IgE antibodies that play a central role in mediating allergic reactions. Interleukin 13 (IL-13) is a novel T-cell-derived cytokine that shares several functional properties with IL-4 and has been demonstrated to be capable of inducing IgE synthesis. The present study was designed to investigate the expression of IL-13 gene in the epithelial compartment of the nasal mucosa of patients with perennial allergic rhinitis (PAR) to house dust mite, comparing it with that in the nasal epithelial compartment of chronic infectious rhinitis (CIR) patients and normal volunteers (NV). We also investigated the IL-13 gene expression in the peripheral blood of PAR patients. Nasal scrapings were collected from the inferior turbinate of patients undergoing conchotomy surgery and from outpatients, and the mRNA expression of IL-13 was analyzed by the RT-PCR method. Peripheral blood mononuclear cells were isolated by density-gradient centrifugation and the expression of IL-13 gene was examined by the RT-PCR method. IL-13 expression at protein level and its cell source were analyzed by immunohistochemistry of inferior turbinate biopsies. The levels of total serum IgE and allergen-specific IgE antibodies in the serum were estimated by the PRIST and CAP RAST method, respectively. IL-13 gene expression was detected in the epithelial compartment of the nasal mucosa of 18/19 PAR patients but was undetected in normal volunteers and CIR patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Erythroleukemia in two cats naturally infected with feline leukemia virus in the same household.
Erythroleukemia was observed in two unrelated cats infected with feline leukemia virus (FeLV) from the same household. Case 1, a 1-year-old neutered male cat developed erythroleukemia (M6) after a diagnosis of myelodysplastic syndrome (MDS-Er) on the criteria of FAB classification of acute leukemias. Case 2, a 1-year-old neutered female cat, which had close contact with Case 1, also developed erythroleukemia (M6Er). In both cases, marked proliferation of erythroid progenitor cells with disproportionally large numbers of immature forms was observed in the bone marrow. In Case 1, neoplastic proliferation of myeloid cells in the bone marrow was also noted at the terminal stage. Combination chemotherapy with daunomycin was partially effective for treatment of these erythroid neoplasias, but did not induce complete remission. Southern blot analysis using exogenous FeLV-specific probes indicated the clonal origin of these hematopoietic tumor cells. Furthermore, the erythroid and myeloid tumor cells in Case 1 were shown to be derived from independent transformed clones. A variant FeLV was shown to be integrated into the tumor cells in Case 1, while a full-length FeLV was found in both cases. Because these erythroid neoplastic diseases occurred in two unrelated cats kept in the same household and these diseases are rare, they may both have been associated with the same FeLV strain.
Animals↗
[Cytokines of nasal inverted papilloma: quantification and distribution].
We previously found that an increased number of mucosal mast cells accumulated in the tumor site of nasal inverted papilloma as well as in the epithelial layer of the allergic nasal mucosa. However, the mechanism of accumulation of mucosal mast cells has not yet been clarified. The purpose of this study was to evaluate the cytokines produced by inverted papilloma cells, which would be important for the accumulation of mucosal mast cells. We found that the supernatant of the monolayer of cultured inverted papilloma cells contained GM-CSF, IL-6 and IL-8. IL-2, IL-3, IL-4 and IL-5 were not detected. Contrary to the quantities of cytokines detected in the supernatant of cultured allergic nasal epithelial cells, the quantities of IL-6 and IL-8 were greater in the supernatant of cultured inverted papilloma, whereas that of GM-CSF was less. Immunohistochemical study revealed the distribution of cytokines: GM-CSF was detected near the basement membrane of the tumor site, while IL-6 and IL-8 were detected in the superficial layer of nasal inverted papilloma. Interestingly, the tumor site near the basement membrane is also the site of accumulation of mucosal mast cells, suggesting that GM-CSF produced by nasal inverted papilloma cells may be one of the most important factors in the accumulation of mucosal mast cells.
Adult↗
[Complete remission by cytarabine ocfosfate plus G-CSF therapy in a patient with hypoplastic RAEB-T].
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Administration, Oral↗
[Clinical evaluation of positive- and negative-stranded HCV-RNAs in liver in relation to IFN therapy].
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Adult↗
Electron microscopical studies of the cell population in nasal secretions.
The purpose of this study is to identify the cell types and ultrastructural changes of the cells in nasal secretions, and to understand the pathology of allergic and infectious rhinitis. Nasal secretions from 20 patients with allergic rhinitis and 15 patients with infectious rhinitis have been observed by transmission electron microscopy. The cell population of the allergic group consists of (in order of predominance): epithelial cells, eosinophils, neutrophils, lymphocytes, basophilic cells (basophil leukocytes and mast cells), and macrophages. In the infectious group the population contains: neutrophils, epithelial cells, macrophages, and lymphocytes. Marked degranulation has been observed in the granules of eosinophils in allergic nasal secretions together with granule fusion, vacuolation, and signs of phagocytosis. Increased numbers of basophil leukocytes and mast cells are also a feature of the allergic nasal secretion. Degranulation of neutrophils is markedly increased in the infectious group as compared to the allergic group. Clustered epithelial cells are observed in the allergic group more often than in the infectious group. Four types of lymphocytes with different morphological features are observed in both groups, i.e. small lymphocyte, T-lymphocyte-like cells, large granular lymphocyte-like cells, and plasma cells. The results of the present study show special ultrastructural characteristics in the cell population of allergic nasal secretions, i.e., an increase in the number of degranulated eosinophils and basophilic cells, clustered epithelial cells, and large granular lymphocytes, while an increase in degranulated neutrophils and macrophages with marked phagocytosis are characteristic for infectious nasal secretions.
Adult↗
[Clinical evaluation of prophylactic nitroglycerin infusion during coronary artery bypass grafting].
We evaluated retrospectively the benefit of prophylactic nitroglycerin (TNG) infusions during elective coronary artery bypass grafting (CABG) in 73 patients. In all patients anesthesia was maintained with high dose fentanyl. Thirty-seven patients were infused TNG 0.3 microgram.kg-1.min-1 during surgery and 36 patients were not. The TNG-infused patients demonstrated lower perfusion pressure during cardiopulmonary bypass (CPB) and higher incidence of inotropic administrations than the uninfused patients. Serum myocardial creatine phosphokinase (CPK-MB) levels of TNG-infused patients were higher than those of TNG-uninfused patients on the first postoperative day. We speculate that inotropic administrations under low myocardial perfusion pressure at the time of weaning from CPB induces myocardial ischemia which in turn causes an increase in serum CPK-MB level. We conclude that prophylactic administration of TNG does not prevent perioperative ischemia during CABG.
Anesthesia, General↗
Cloning and characterization of a rat H+/peptide cotransporter mediating absorption of beta-lactam antibiotics in the intestine and kidney.
A complementary DNA (cDNA) encoding the rat H+/peptide cotransporter (PepT1) was isolated, and the transport characteristics of orally active beta-lactam antibiotics were assessed by measuring uptake into Xenopus oocytes expressing the rat PepT1. The rat PepT1 cDNA encoded a 710-amino acid protein with 77% identity to the rabbit PepT1. The message for rat PepT1 was approximately 2.9 kilobases and was found predominantly in the small intestine, whereas reverse transcription-polymerase chain reaction amplification revealed that the message was expressed both in the small intestine and in the kidney cortex. The 75-kDa protein was identified by translation of in vitro synthesized transcript of rat PepT1 cDNA by use of rabbit reticulocyte lysates and by Western blot analysis with a specific antibody against the rat PepT1. When expressed in Xenopus oocytes, rat PepT1 stimulated the uptake of ceftibuten (anion) and cephradine (zwitterion) in the presence of an inward H+ gradient, and the expressed uptake was inhibited by excess dipeptides. Kinetic analysis revealed that ceftibuten has 14-fold higher affinity for the rat PepT1 than cephradine. These findings suggest that the rat PepT1 mediates H(+)-coupled uphill transport of the oral beta-lactam antibiotics across the brush-border membranes of intestinal and renal proximal tubular cells.
Amino Acid Sequence↗
[Generation of tumor necrosis factor alpha by human nasal epithelial cells and inhibition by fluticasone propionate].
Accumulation of mast cells and eosinophils in the nasal epithelial layer occurs in nasal allergic reaction, However, the mechanism of accumulation of these cells has not yet been well clarified. We hypothesized that cytokines generated from the nasal epithelial cells contributed to the accumulation of these cells in the nasal epithelial layer. Recently tumor necrosis factor (TNF) was shown to promote polymorphonuclear neutrophils and eosinophils migration. And also TNF increased eosinophil binding to vascular endothelial cells. In this in vitro study we examined whether or not nasal epithelial cells can produce TNF-alpha and also whether or not glucocorticosteroid fluticasone propionate (FP) can modulate TNF-alpha production from nasal epithelial cells. Nasal epithelial cells constitutively produce TNF-alpha in accordance with the nasal epithelial cells' number and this was substantially increased in the state of nasal epithelial cell's proliferating. FP significantly reduced the level of TNF-alpha in the supernatant of cultured nasal epithelial cells for a period of 6 days. In addition, preincubation of nasal epithelial cells with FP for 6 days caused significant reduction of TNF-alpha level in the supernatant of cultured nasal epithelial cells during a further period of 6 days without FP. These data support the concept that structural cells play an active role in the control of allergic and related inflammatory processes.
Adult↗
A novel mono-sulfated pentaglycosylceramide with the isoglobo-series core structure in rat kidney.
A five-sugar sulfated glycosphingolipid containing an isoglobo-series carbohydrate core was isolated from rat kidney and its structure characterized by compositional analysis, FTIR spectroscopy, methylation analysis and 1H NMR spectroscopy of the intact glycolipid and its limited degradation products, and negative liquid secondary ion mass spectrometry (LSIMS). The two dimensional chemical shift correlated spectroscopy and NOE spectroscopy provided information on the sugar sequence and linkage as well as anomeric configurations, so as to establish the presence of a 3-O-sulfated galactose and a Gal alpha 1-3Gal structure within the molecule. Negative LSIMS with collision-induced dissociation defined the sugar sequence and ceramide composition, allowing to confirm the presence, and indicating the position, of the sulfate group. The glycosphingolipid was found to be a mono-sulfated derivative of the isoglobo-series core, with the following structure: HSO3(-)-3Gal beta 1-3GalNAc beta 1-3Gal alpha 1-3Gal beta 1-4Glc beta 1-1Cer (iGb5Cer V3-sulfate).
Animals↗
Two forms of the mb-1 gene transcript in cattle.
We have isolated two forms of bovine mb-1 cDNA clones from a cDNA library of a bovine leukemia virus-infected B-lymphoblastoid cell line. The nucleotide sequence analysis of these cDNA clones indicated that the shorter form of cDNA had a 119-bp deletion that precisely corresponded to the exon III domain of the human and murine mb-1 genes. This deletion would result in a frame shift, producing a premature translation termination leading to the lack of the entire transmembrane and cytoplasmic domains of the normal mb-1 molecule. The existence of two species of mRNA transcripts corresponding to the isolated cDNA clones were confirmed in all of the bovine leukemia cell lines examined by PCR with the use of the primers flanking the deletion site. Furthermore, the shorter mb-1 transcript was induced in normal PBMC by stimulation with mitogens or culture supernatants of bovine leukemia virus-infected cell lines. These findings indicate the presence of the truncated mb-1 gene product which may have some function different from that of the normal mb-1 gene product.
Alternative Splicing↗
Site-directed mutagenesis of human ferrochelatase: identification of histidine-263 as a binding site for metal ions.
In nature, ferrochelatase catalyzes the insertion of ferrous ion into the porphyrin macrocycle of protoporphyrin IX to exclude two protons to form protoheme IX: other porphyrin substrates, including mesoporphyrin IX may be used in vitro. Based on the deduced amino-acid sequences, one histidine residue (H263 of human enzyme) is conserved among all ferrochelatases cloned from human to bacterial cells, and three histidine residues (H157, H341 and H388 of human enzyme) are conserved among eukaryotic ferrochelatases; no cysteine residue is conserved. To attempt to clarify the binding site of ferrous ion, we converted four highly conserved histidine residues in human ferrochelatase to alanine, using site-directed mutagenesis. The mutant enzymes were expressed in Escherichia coli, and iron- and zinc-chelating activities were examined. Mutants H157A and H388A lost most of their activities and concomitantly the enzyme became susceptible to proteolytic degradation. Kinetic studies with the residual activities showed no significant change of Km values for metal ions or for mesoporphyrin IX. Mutation at H341 did not alter the enzyme activities. Iron- and zinc-chelating activities of mutant H263A were reduced to 30% and 21% of the activities of the wild type, respectively. Moreover, this mutation resulted in 18- and 3.4-fold increases in Km values toward ferrous and zinc ions, respectively, while the Km value for mesoporphyrin remained unchanged. These results indicate that the binding site for metal ions in ferrochelatase is distinct from that for the porphyrin, and suggest that histidine-263 contributes significantly to the binding of metal ions. Maintenance of the structure of the protein molecule may involve functions related to histidine-157 and -388.
Alanine↗
Cloning of feline p53 tumor-suppressor gene and its aberration in hematopoietic tumors.
Alterations of the p53 tumor-suppressor gene have been observed in a variety of human and mouse tumors. For investigation of the role of this gene in tumors of cats, feline p53 cDNA was molecularly cloned from a feline lymph-node cDNA library. The cloned cDNA (FF53) contained the whole open reading frame of p53 gene encoding 386 amino acids. The amino-acid sequence of the feline p53 gene showed 82.1% and 74.9% similarities with those of the human and mouse counterparts, respectively, and had structural characteristics in common with the p53 genes of several other species. Aberrations of the p53 gene were investigated by RT-PCR and single-strand conformation polymorphism analyses. Of 10 primary hematopoietic tumors and 3 lymphoma cell lines examined, one lymphoma and one lymphoma cell line had a point mutation of the p53 gene, resulting in single amino-acid substitutions.
Amino Acid Sequence↗
Overexpression in Escherichia coli, and one-step purification of the human recombinant ferrochelatase.
Ferrochelatase (EC 4.99.1.1), a mitochondrial inner membrane-bound protein, is the terminal enzyme of heme biosynthesis. The cDNA encoding the human mature ferrochelatase was placed under transcriptional control of T7 RNA polymerase in an Escherichia coli expression system. The bacteria produced large amounts of 42 kDa protein which reacted with anti-ferrochelatase antibodies. Expressed ferrochelatase exhibited iron- and zinc-chelating activities, and was found as a soluble protein. The recombinant enzyme has been purified to apparent homogeneity with a high yield, by one-step purification involving Blue-Sepharose chromatography. The purified enzyme which showed a molecular weight of about 40,000 by gel-filtration, functioned in a monomeric form. Km value for both mesoporphyrin IX and protoporphyrin IX with zinc was 12.5 microM. Km values for iron and zinc with mesoporphyrin IX were 6.7 microM and 11.8 microM, respectively. Zinc-chelating activity was markedly stimulated by palmitic acid, but iron-chelating activity remained unchanged. The above results were similar to those reported previously for mammalian ferrochelatase. The overexpression and the simple purification of a functional ferrochelatase exhibiting the same properties as natural enzyme will allow us to elucidate the mechanism of the enzyme reaction and structural changes of the mutated enzyme.
Amino Acid Sequence↗
Angiotensin II inhibits cytokine-stimulated inducible nitric oxide synthase expression in vascular smooth muscle cells.
In cultured vascular smooth muscle cells (VSMC), inflammatory cytokines such as interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha stimulated nitric oxide (NO) production via the expression of an inducible type of NO synthase (iNOS). A potent vasoconstrictor, angiotensin II (Ang II), which causes a rapid phospholipase C-mediated phosphoinositide hydrolysis via the Ang II type 1 (AT1) receptor in VSMC, by itself did not stimulate the production of nitrite, a stable metabolite of NO, but dose dependently inhibited the IL-1 beta-induced nitrite production. This inhibitory effect of Ang II was blocked by an AT1 receptor antagonist, CV-11974, but not by an Ang II type 2 receptor antagonist, PD 123319. The presence of Ang II during the early induction phase of iNOS was required for this inhibition. Consistently, Ang II suppressed IL-1 beta-induced increases in iNOS mRNA and protein levels. Ang II also inhibited increases in nitrite production and iNOS mRNA and protein levels caused by tumor necrosis factor alpha. A protein kinase C-activating phorbol ester, phorbol 12-myristate 13-acetate, and a membrane-permeable diacylglycerol, 1,2-dioctanoyl-glycerol, similarly inhibited the IL-1 beta-induced nitrite production and iNOS mRNA and protein expression, although repetitive additions were needed in the case of diacylglycerol. These results indicate that Ang II negatively modulates cytokine-induced NO production by blocking iNOS expression via the AT1 receptor in VSMC and suggest that protein kinase C could be involved in this process.
Amino Acid Oxidoreductases↗
Induction of peripheral-type benzodiazepine receptors during differentiation of mouse erythroleukemia cells. A possible involvement of these receptors in heme biosynthesis.
To search for a possible role for peripheral-type benzodiazepine receptors (PBR) during erythroid differentiation, we cloned the PBR isoquinoline carboxamide-binding protein (PBR/IBP), an 18-kDa protein on PBR, from a mouse erythroleukemia (MEL) cell cDNA library. Sequence analysis revealed that PBR/IBP comprises 169 amino acid residues (M(r) 18,828), and has a high homology with PBR/IBP from other sources. The cDNA allows for the expression of active PBR/IBP, exhibiting a high affinity for isoquinoline carboxamide, [3H]PK11195, with Kd of 0.80 and 1.56 nM. RNA blot analysis revealed that treatment of MEL cells with dimethyl sulfoxide led to an increase in PBR/IBP mRNA (delta 1.0 kilobases) for up to 72 h, with a concomitant induction of mRNAs for heme biosynthetic enzymes, coproporphyrinogen oxidase and ferrochelatase. The induction of PBR/IBP mRNA was also observed in MEL cells induced with diazepam. The binding activity of [3H]PK11195 in MEL cells showed a high affinity with Kd of 0.69-2.13 nM, and increased during erythroid differentiation. The order of potency of different ligands to compete against [3H]PK11195 binding in induced MEL cells was PK11195 > protoporphyrin IX > diazepam > coproporphyrinogen III > coproporphyrin III > estazolam. In contrast to the induction of PBR/IBP in induced MEL cells, the voltage-dependent anion channel (mitochondrial porin) associated with PBR remained unchanged. These results suggest that PBR/IBP on PBR may be involved in porphyrin transport and may even be a critical factor in erythroid-specific induction of heme biosynthesis.
Amino Acid Sequence↗