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Biomedical subjects

Y Higuchi

Publications and source records attributed to Y Higuchi.

At least 19 recordsLinked to original sources
PubMed1992

Expression of a tumor necrosis factor alpha transgene in murine pancreatic beta cells results in severe and permanent insulitis without evolution towards diabetes.

Mice bearing a tumor necrosis factor (TNF) alpha transgene controlled by an insulin promoter developed an increasingly severe lymphocytic insulitis, apparently resulting from the induction of endothelial changes with features similar to those observed in other places of intense lymphocytic traffic. This was accompanied by dissociation of the endocrine tissue (without marked decrease in its total mass), islet fibrosis, and the development of intraislet ductules containing, by places, beta cells in their walls, suggesting a regenerative capacity. Islet disorganization and fibrosis did not result from lymphocytic infiltration, since they were also observed in SCID mice bearing the transgene. Diabetes never developed, even though a number of potentially inducing conditions were used, including the prolonged perfusion of interferon gamma and the permanent expression of a nontolerogenic viral protein on beta cells (obtained by using mice bearing two transgenes). It is concluded that (a) a slow process of TNF release in pancreatic islets induces insulitis, and may be instrumental in the insulitis resulting from local cell-mediated immune reactions, but (b) that insulitis per se is not diabetogenic, lymphocyte stimulation by cells other than beta cells being necessary to trigger extensive beta cell damage. This provides an explanation for the discrepancy between the occurrence of insulitis and that of clinical disease in autoimmune diabetes.

Animals↗
PubMed1992

Identification of a tissue-specific regulatory element within the murine CD14 gene.

We previously isolated and sequenced the 5'-flanking region of the mouse CD14 (mCD14) gene (Matsuura, K., Setoguchi, M., Nasu, N., Higuchi, Y., Yoshida, S., Akizuki, S., and Yamamoto, S. (1989) Nucleic Acids Res. 17, 2132). To define the regulatory elements that control expression of the mCD14 gene, we analyzed the structure of the 5' end of the gene, including a region further upstream of that determined previously. Sequentially 5'-deleted, chimeric, and point mutated clones were tested for the ability to stimulate chloramphenicol acetyltransferase. An 8-base pair sequence, TGATTCAC, at position -255, which resembled the consensus sequence of the 12-O-tetradecanoylphorbol-13-acetate-responsive element (TRE), enhanced the expression of the chloramphenicol acetyltransferase gene in macrophage (aHINS-B3) and non-macrophage (glioblastoma G203 and myeloma NS1) cells. The enhancing ability of the TRE-like sequence (TLS), however, was markedly reduced in G203 cells but not in aHINS-B3 cells when the TLS was followed by the sequence immediately downstream. The TLS and sequence immediately downstream were capable of binding nuclear proteins which were unique to aHINS-B3 cells and macrophages, suggesting that these unique protein regulate the specific expression of the mCD14 gene. Binding of AP-1 to the TLS was also found in aHINS-B3 and G203 cells. Although it is uncertain whether AP-1 is involved in expression of the mCD14 gene, the effect of AP-1 in non-macrophage cells was inhibited by a nuclear protein which binds to the sequence immediately downstream of the TLS.

Animals↗
PubMed1992

XELE--a polypeptide model-building program for a graphics workstation.

A model-building program, XELE, for use in protein crystallography has been written in C under UNIX on a graphics workstation. This program makes full use of the X Window system to display the electron density distribution and to manipulate the polypeptide model, and therefore is named XELE. It utilizes a fast three-dimensional rendering package, Dorè, and is portable to other types of graphics workstations. A part of the program for the man-machine interface uses the library of X Window and X Toolkit, and therefore is highly interactive. The structure analysis program package, PROTEIN, is also implemented in an interactive mode using X Window, and has been interfaced with XELE.

Computer Graphics↗
PubMed1992

Cervical island skin flap for intraoral repair following cancer surgery.

Seventy three patients with oral cancer were operated on using the cervical island skin flap of Farr et al. (1969). Primary sites of the lesions were the tongue, floor of the mouth and lower gingiva. Most of the patients received total doses of 22.5 Gy of radiation and 110 mg bleomycin as a preoperative treatment. Among the 73 patients, complete necrosis of the skin island was observed in 3 cases. There was half necrosis in 4 cases, one quarter necrosis in 6 cases and marginal necrosis in 17 cases. The flaps in 43 patients completely survived. Results were better in the operations undertaken in the last 4 years in which a superficial layer of deep cervical fascia on the sternocleidomastoid muscle was included in the flap.

Adult↗
PubMed1992

Sequence analysis of the large (L) protein of simian virus 5.

The complete nucleotide sequence of the large (L) protein gene of simian virus 5 (SV5) was determined from cDNA of the genomic RNA and mRNA, and found to be 6804 bases in length, exclusive of a poly(A) tract. The sequence contained an open reading frame of 6765 nucleotides encoding 2255 amino acids. Results of dot matrix comparisons of the L protein of SV5 with those of human parainfluenza type 3 virus and Sendai virus indicated that there are five conserved domains, and that each domain contains characteristic sequence(s). The L protein of SV5 was detected in purified virions using antiserum directed against an oligopeptide corresponding to the N-terminal region.

Amino Acid Sequence↗
PubMed1992

[The usefulness of dipyridamole stress myocardial scintigram as a preoperative test for detecting ischemic heart disease before vascular surgery].

We evaluated the usefulness of dipyridamole 201Tl myocardial scintigraphy (DS) for detecting myocardial ischemia in 18 candidate for vascular surgery. DS indicated significant thallium redistribution in 6 patients. Coronary angiography was performed in 5 of these 6 patients and revealed significant coronary artery disease in all patients. As a result, operation was cancelled in 4 patients with severe coronary artery disease. One of these cases died of acute myocardial infarction after being discharged from hospital. One other patient was operated after percutaneous transluminal coronary angioplasty. Another patient was operated knowing that he had significant but mild coronary artery disease. Subsequently, operations were performed in 14 patients. No serious cardiac event occurred in these 14 patients except one case with T wave inversion without myocardial enzyme elevation. Thus, we concluded that DS was a useful method for detecting ischemic heart disease and prevent cardiac event associated with vascular surgery.

Aged↗
PubMed1991

Evaluation of x-ray diffraction data from protein crystals by use of an imaging plate.

A system has been developed which uses an imaging-plate diffraction apparatus to obtain structure factors for protein crystals. The latter is connected to a graphics workstation through an Ethernet. Pixel data from an imaging plate are transferred via the Ethernet to a workstation and processed to give the structure factors. The quality and precision of the diffraction data were examined from the point of view of spatial uniformity, linearity with exposure, decay with time, and reproducibility. X-rays from an 55Fe source and Debye-Scherrer rings from Si powder were used for calibration purposes. Finally, diffraction data were obtained and evaluated for lysozyme and cytochrome c-553 using this system. The results were satisfactory in terms of sensitivity and precision.

Protein Conformation↗
PubMed1991

1H NMR studies on ferricytochrome c3 from Desulfovibrio vulgaris Miyazaki F and its interaction with ferredoxin I.

The 1H NMR signals of the heme methyl, propionate and related chemical groups of cytochrome c3 from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were site-specifically assigned by means of 1D NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by Fan et al. (Biochemistry, 29 (1990) 2257-2263). The site-specific heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val18. All the results contradicted the heme assignments for D.v. MF cytochrome c3 made on the basis of electron spin resonance (Gayda et al. (1987) FEBS Lett., 217 57-61). Based on these assignments, the interaction of cytochrome c3 with D.v. MF ferredoxin I was investigated by NMR. The major interaction site of cytochrome c3 was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochrome c3 molecules per monomer of ferredoxin I and 10(8) M-2 (at 53 mM ionic strength and 25 degrees C), respectively.

Binding Sites↗
PubMed1991

Congenital dermoid fistula of the lower lip.

A case of congenital dermoid fistula of the lower lip is presented. The lesion consisted of a major cystic portion, a proximal tubelike extension that opened in the lower lip as a small sinus (pit) near the left commissure, and a distal cordlike extension that entered into the left mental foramen. The cystic cavity was lined with keratinizing stratified squamous epithelium, and many sebaceous glands, sweat glands, and hair follicles were seen subcutaneously. The differential diagnosis and the pathogenesis of the lesion are also discussed.

Adolescent↗
PubMed1991

Unusual ameloblastoma with extensive stromal desmoplasia.

A clinicopathological study of 5 cases of unusual ameloblastoma was performed. Three cases were characterized by marked stromal desmoplasia. The lesions occurred in the tooth-bearing areas of the anterior or premolar regions of the jaw. They were relatively small and showed a honeycomb appearance radiographically. Histologically, the islands of tumour cells were small and discrete in the widely extended desmoplastic stroma. They lacked obvious ameloblastic polarity in many parts. The other 2 cases were hybrid lesions of desmoplastic and conventional types. The former appeared in the alveolar part and the latter in the lower part of the mandible. It was concluded that the desmoplastic variant of ameloblastoma could be categorized as a new distinct type histologically, clinically and radiographically.

Adult↗
PubMed1991

Molecular and physiological properties of murine CD14.

We have previously cloned the murine homolog of cDNA for the human myelomonocytic differentiation antigen, CD14. We synthesized three hydrophilic peptides derived from the predicted amino acid sequence of murine CD14 (mCD14), designated MS7.1, MS7.2, and MS7.3, respectively, and raised antisera against them. Each antiserum showed specific reactivity to the same peptide used for immunization. One of the anti-mCD14 antisera directed against MS7.3 peptide (AMS7.3) demonstrated the highest titer and definitively reacted with monocytic cell lines, inflammatory polymorphonuclear cells, and macrophages. Significant cross-reactivity of AMS7.3 was observed in the human monocytic cell line, THP-1. COS-1 cells transfected with MS7 cDNA expressed an antigen recognized by AMS7.3. Resident peritoneal and alveolar macrophages both expressed mCD14. mCD14 expression in peritoneal but not alveolar macrophages increased after treatment with lipopolysaccharide. Expression of mCD14 varied among monocytic cell lines and roughly paralleled the mRNA levels except in MI cells. SDS-PAGE and isoelectric focusing analysis of immunoprecipitated mCD14 showed that mCD14 was a 53 kd disulfide-linked protein with a pI of 4.5-5.1. Reduction of molecular weight by endo F treatment demonstrated that mCD14 was an N-linked glycoprotein. Since mCD14 is shed from the cell surface membrane by phosphatidylinositol-specific phospholipase C treatment, the indication is that mCD14 is a phosphatidylinositol-linked protein. The soluble form of mCD14 was detectable. Treatment with anti-mCD14 before interferon gamma (IFN gamma) stimulation significantly enhanced IFN gamma-induced H-2 antigen expression in the macrophage cell line.

Amino Acid Sequence↗
PubMed1991

Effects of amino acid substitution on three-dimensional structure: an X-ray analysis of cytochrome c3 from Desulfovibrio vulgaris Hildenborough at 2 A resolution.

The three-dimensional structure of cytochrome c3 from Desulfovibrio vulgaris Hildenborough has been determined by use of the molecular replacement method and refined at 2.0 A resolution. A suitable crystal of the cytochrome c3 was obtained from buffer solution (25 mM Tris-HCl, pH 7.4), with 75% ethanol as the precipitating reagent. Crystallographic data are as follows: a = 43.17 A, b = 62.91 A, c = 41.17 A, orthorhombic, P2(1)2(1)2(1) and Z = 4. Constrained least-squares refinement and a molecular dynamics procedure with a simulated structure annealing method yielded a crystallographic R-factor of 0.212. The similarity in the folding pattern of both cytochromes c3 is established, the mean deviation of the polypeptide backbone between the two structures being 0.367 A. Most of the amino acids substitutions from DvMF were located on the surface of the molecule, and in particular, S27 and V86 were placed near the propionic acid of the heme group so as to hang over the heme and the cleft of the molecule.

Amino Acid Sequence↗
PubMed1991

Molecular relationships between human parainfluenza virus type 2, and simian viruses 41 and 5: determination of nucleoprotein gene sequences of simian viruses 41 and 5.

The nucleotide sequences of cDNAs of the simian virus 5 (SV5) nucleoprotein (NP) gene, and the 3' end of the genome and NP gene of SV41 were determined. The open reading frames of the SV5 and SV41 NP genes encode polypeptides with Mrs of 56,582 and 60,575, respectively, values which are consistent with those estimated by SDS-PAGE. The NP of human parainfluenza virus type 2 (hPIV-2) was more closely related to that of SV41 (amino acid sequence identity 70.5%) than that of SV5 (57.0%); the amino acid sequence identity between the NPs of SV41 and SV5 was 63.3%. The sequence of the 3' end of the genome of SV41 showed a high level of similarity to that of hPIV-2, the terminal 18 nucleotides being identical. It is concluded from these findings that SV41 is related most closely to hPIV-2, even though SV5 had been thought to be an animal type of hPIV-2.

Amino Acid Sequence↗
PubMed1991

Enhancement of the antitumor effect of glucose oxidase by combined administration of hydrogen peroxide decomposition inhibitors together with an oxygenated fluorocarbon.

Glucose oxidase (GO) catalyzes the conversion of beta-D-glucose and molecular oxygen to D-glucono-delta-lactone and H2O2. H2O2 produced by GO was effective in preventing tumor growth in mice bearing not only ascites tumor but also solid tumor. The effect of GO was enhanced by the combined administration of catalase inhibitors such as 3-aminotriazole, hydroxylamine and sodium azide or the GSH synthesis inhibitor buthionine-(S,R)-sulfoximine in vivo. The cytolytic activity of GO against T-24 cultured cells in vitro was also enhanced by addition of these inhibitors together with GO. In the peritoneal cavity of mice the antitumor effect of GO seemed to be dependent on the amount of oxygen released from oxygenated fluorocarbon-43 (FC-O2), an oxygen-supplying substance. Furthermore, the combined administration of H2O2-decomposing enzyme inhibitors and FC-O2 synergistically enhanced the antitumor effect of GO. These results suggest that GO is suitable for antitumor chemotherapy and that the use of inhibitors of H2O2-decomposing enzymes and FC-O2 potentiated the GO therapy.

Animals↗
PubMed1991

Parainfluenza virus pneumonitis in an adult.

Parainfluenza virus uncommonly causes fatal giant cell pneumonia in immunocompromised infants and children. To our knowledge, this is the first adult case of parainfluenza virus pneumonia. A 77-year-old woman who was diagnosed as having small-cell carcinoma of the lung underwent chemotherapy. She died of lung edema. Analysis of her serum showed antibodies to parainfluenza virus types 2 and 3 at titers of 1:64 and 1:128, respectively. The postmortem examination revealed giant cell pneumonia, in which giant cells and detached alveolar lining cells had intracytoplasmic inclusions. On electron microscopic examination, the intracytoplasmic inclusions contained fuzzy-form nucleocapsids.

Aged↗
PubMed1990

The mouse osteopontin gene. Expression in monocytic lineages and complete nucleotide sequence.

Murine macrophage cell lines and resident macrophages showed various levels of expression of the murine osteopontin (OP) gene, and macrophage stimulating agents were found to enhance transcription of the gene with kinetics which are unique for each stimulator. The organization of the murine OP gene was determined. The gene comprises six exons and five introns and spans approximately 4.8 kilobases. Exon 1 contains the 16 amino acids of the leader sequence. Exons 2, 3, 4, 5, and 6 encode 12, 27, 14, 94, and 129 amino acid residues, respectively. Exon 5 encodes regions containing 10 consecutive Asp amino acid residues and a Gly-Arg-Gly-Asp-Ser peptide. Exon 6 encodes the C-terminal half of OP and contains no 15- and 54-base pair nucleotide sequences which are deleted in murine OP cDNA compared to that of rat OP cDNA. Since Southern blot analysis indicated that the OP gene is a single copy, it is obvious that the murine OP cDNA has the sequence previously determined (Miyazaki, Y., Setoguchi, M., Yoshida, S., Higuchi, Y., Akizuki, S., and Yamamoto, S. (1989) Nucleic Acids Res. 17, 3298). A comparison with the cDNA sequences reported previously suggested the presence of nucleotide sequence polymorphisms. The 5' end of the murine OP gene was defined by primer extension and S1 nuclease mapping. Sequence analysis of the 5'-flanking DNA revealed the presence of many potential regulatory motifs.

Amino Acid Sequence↗