[The evolution of influenza viruses].
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Animals↗
Biomedical subjects
Y Muraki
Publications and source records attributed to Y Muraki.
TGF-beta 2 increases alpha-smooth muscle actin expression in bovine retinal pigment epithelial cells.
PURPOSE: To examine whether transforming growth factor-beta 2 (TGF-beta 2) induces the expression of alpha-smooth muscle actin (SMA), a biochemical marker of myofibroblasts, in cultured bovine retinal pigment epithelial (RPE) cells. METHODS: Bovine RPE cells were cultured in F-12 nutrient mixture supplemented with 5% fetal bovine serum (FBS), with or without TGF-beta 2 (0.01-10 ng/ml) for 6 days. During this culture period, cells did not reach a confluence. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the ratio of the number of alpha-SMA positive cells to the total number of cells was calculated. RESULTS: About 10% of the cells in control cultures with only FBS were positive for alpha-SMA. TGF-beta 2 increased the ratio of positive cells dose-dependently (p < 0.0001), while a neutralizing antibody against TGF-beta 2 blocked this effect. CONCLUSIONS: TGF-beta 2 induced expression of alpha-SMA in bovine RPE cells.
Actins↗
Analysis of molluscum contagiosum virus genomes isolated in Japan.
The genomes of 477 Japanese strains of molluscum contagiosum virus (MCV) were analyzed using an in-gel digestion method with the restriction enzyme BamHI, and classified into four types, including a newly detected type (MCV type 4). All type 1 (MCV-1) genomes examined so far in Japan showed a common difference from the genome of the MCV-1 prototype (MCV-1p), the type reported to be most prevalent in Europe. The common markers of the variants of MCV-1 were 24-kbp fusion fragments generated by the loss of a BamHI site between the D2 and F fragments of MCV-1p. These variants of MCV-1 were classified into three groups (MCV-1va, MCV-1vb, MCV-1vc), with the variability among them being due to additions and losses of BamHI sites located in the right terminus and around the E and I fragments of MCV-1va. The restriction map of MCV-4 was generated and lined up with those of the other types. Cross-hybridization analysis revealed that the organization of all types of MCV genomes were essentially colinear. Considerable numbers of BamHI restriction sites were conserved between MCV-2 and 4, indicating a close analogy between them. The overall prevalence of MCV, as shown by the ratios of MCV-1 (MCV-1p):MCV-2:MCV-3:MCV-4, was 436(0):13:24:4. Thus, the molecular epidemiology of MCV in Japan is characterized by the absence of the European prototype of MCV-1, the exclusive occurrence and abundance of variants of MCV-1, a greater prevalence of MCV-3 over MCV-2, and the presence of MCV-4.
Genetic Variation↗
Comparison of receptor-binding properties among influenza C virus isolates.
A total of 10 influenza C virus strains isolated recently in Yamagata City, Japan and shown to belong to the same lineage was compared for the ability to agglutinate chicken and mouse erythrocytes under various conditions. C/Yamagata/10/89 was unique in lacking the ability to agglutinate chicken erythrocytes at a temperature > or = 4 degrees C. This isolate also agglutinated native mouse erythrocytes only very inefficiently, although the high agglutination titer was obtained with the glutaraldehyde-fixed cells. Furthermore, it was found that C/Yamagata/4/88, unlike the other isolates, agglutinated erythrocytes from chickens to lower titers than those from mice, even when assayed at 0 degree C. Comparison of the deduced amino acid sequence of hemagglutinin-esterase among the 6 representative strains including two older isolates, C/Yamagata/26/81 and C/Nara/2/85, suggested that the failures of C/Yamagata/10/89 to agglutinate chicken erythrocytes at > or = 4 degrees C and unfixed mouse erythrocytes to high titers may be due to amino acid changes at residues 337 (Glu-->Lys) and 340 (Thr-->Tyr), respectively, and that a change at residue 347 (Leu-->Ser) may be responsible for the decreased ability of C/Yamagata/4/88 to agglutinate chicken erythrocytes.
Amino Acids↗
Identification of influenza C virus phosphoproteins.
The HMV-II cells infected with influenza C virus were labeled with inorganic [32P]phosphate to identify phosphorylated proteins. Analysis by radioimmunoprecipitation with antiviral serum or monoclonal antibodies revealed that three major structural proteins of the virus, hemagglutinin-esterase (HE), nucleoprotein (NP), and matrix protein (M1) are all phosphorylated in both infected cells and virions. It was also observed that, in the presence of trypsin (10 micrograms/ml), the unphosphorylated form of the HE glycoprotein was cleaved efficiently whereas the phosphorylated form was not, raising the possibility that phosphorylation of HE may influence its susceptibility to degradation by proteolytic enzymes.
Antibodies, Monoclonal↗
C-fos gene expression in rat retinal cells after focal retinal injury.
PURPOSE: To examine the expression of c-fos proto-oncogene in the rat retina after focal retinal injury. METHODS: A penetrating wound was made by pushing a 22-gauge hypodermic needle through the retina into the vitreous. The retinas were analyzed by in situ hybridization using single-stranded RNA probes for c-fos transcripts and by immunocytochemistry using anti-S100 protein antibody. RESULTS: Thirty minutes after the penetrating wound, c-fos mRNA was expressed in the inner nuclear layer (INL) and the ganglion cell layer (GCL) of the retina. Immunocytochemistry before in situ hybridization demonstrated c-fos mRNA surrounding the S-100 protein immunoreactive cytoplasm in the middle layer of the INL. CONCLUSIONS: Focal retinal injury of the rat retina induced the expression of c-fos mRNA in retinal cells. In the INL, it is suggested that the major cells that express c-fos mRNA after focal retinal injury were the Müller cells. These results suggest that c-fos may be involved in the transcription in the Müller cells after injury to the retina.
Animals↗
[Electron microscopic studies of retinal pigment epithelial cells incubated with L-dopa in 10% and 20% oxygen].
In order to make clear how the ultrastructure of the bovine second-passage retinal pigment epithelium (RPE) was affected by exposure to L-dopa and oxygen, we compared the toxic effects of melanotic and amelanotic RPE. The oxygen levels in the incubators and the L-dopa concentrations in the media were adjusted to 10% or 20% oxygen by adding nitrogen gas and 100 microM or 250 microM L-dopa, respectively. After 24 hours, melanotic and amelanotic RPE were fixed and embedded in epon. Ultrathin sections were examined by transmission electron microscopy. Rough endoplasmic reticula were found to be dilated and ribosomes were extinguished in both melanotic and amelanotic RPE. The damage by L-dopa in melanotic RPE was less than that in amelanotic RPE and less in 10% oxygen than in 20% oxygen.
Animals↗
Fluorescence properties of quinacrine- and spin-labelled oligodeoxynucleotide.
Oligodeoxynucleotides involving a stable nitroxide radical, 5-(2,2,5,5-tetramethyl-3-ethynylpyrroline-1-oxyl)-2-deoxyuridine residue (TMP), and a fluorescence dye, quinacrine (Qu), on each complementary strand and those on the same strand in the duplexes were prepared. Three base-pair units locate between TMP and Qu. The interaction between TMP and the excited singlet Qu has been studied by picosecond transient absorption spectroscopy and fluorometry. From the biphasic fluorescence decay profile, it was suggested that there exist two sites of the dye in the oligodeoxynucleotide with the modifiers in the different complementary strands. In addition, no effective fluorescence quenching was observed for this oigodeoxynucleotide. On the other hand, the triphasic fluorescence decay profile was observed for the oligodeoxynucleotide having Qu and TMP in the same strand and the fluorescence was slightly quenched. Picosecond transient absorption spectroscopy revealed that the enhanced intersystem-crossing by TMP was responsible for the quenching of the fluorescent state of the dye. From these results, it has been concluded that the role of the DNA duplex in the quenching process of the dye by TMP was rather small.
Fluorescent Dyes↗
Cocirculation of two distinct groups of influenza C virus in Yamagata City, Japan.
The antigenic and genetic relationships among 15 strains of influenza C virus isolated between August, 1988, and May, 1990, in Yamagata City, Japan, were investigated. Based on the results of antigenic analysis with monoclonal antibodies to the hemagglutinin-esterase (HE) glycoproteins and oligonucleotide mapping of total vRNA, the isolates were divided into two distinct groups closely related to either C/Yamagata/26/81 or C/Aichi/1/81. Antigenic differences between two groups could be detected clearly with heterogeneous antiviral sera. Comparison of the HE gene sequences between the representative Yamagata isolates and the previous isolates from other countries showed that C/Yamagata/26/81-like and C/Aichi/1/81-like viruses had high degrees of nucleotide sequence homology with C/pig/Beijing/115/81 and C/Johannesburg/1/66, respectively. These observations suggest that two lineages of influenza C virus, markedly different from each other in both antigenic and genetic structures, were simultaneously present in Yamagata City during 1988-1990 and that viruses belonging to each of the two lineages may also be prevalent in other areas of Japan and even in other countries.
Amino Acid Sequence↗
The ability of influenza C virus to generate cord-like structures is influenced by the gene coding for M protein.
We observed previously that cord-like structures which had lengths up to 500 microns or greater were protruding from the surface of HMV-II cells infected with influenza C/Yamagata/1/88 virus (Nishimura et al., 1990, Virology 179, 179-188). Comparison of the cord-forming ability among a number of influenza C isolates revealed that the C/Taylor/1233/47 strain was unique in lacking the ability. It was also found that the major structural proteins, hemagglutinin-esterase (HE), nucleoprotein (NP), and matrix (M), could each be distinguished between C/Yamagata/1/88 and C/Taylor/1233/47 viruses by SDS-polyacrylamide gel electrophoresis. To determine the genes involved in the cord formation, a series of reassortant viruses were prepared between C/Yamagata/1/88 and C/Taylor/1233/47, and parental derivation of genes coding for HE, NP, and M was determined by gel electrophoresis. All reassortants which derived M gene from C/Yamagata/1/88, irrespective of derivation of genes coding for HE and NP, had the ability to generate cords, whereas none of reassortants which derived M gene from C/Taylor/1233/47 were capable of producing cords. With respect to several representative reassortants, the origins of genes encoding the polymerase proteins (PB2, PB1, P3) and the nonstructural proteins (NS1, NS2) were determined by T1-oligonucleotide fingerprinting of the isolated RNA segments. The results suggested that none of genes coding for these proteins are exclusively associated with the cord formation. Thus, it is likely that the M gene is the key determinant of the cord-forming ability of influenza C viruses. Nucleotide sequence analysis of the M genes revealed that compared to C/Yamagata/1/88, C/Taylor/1233/47 had two amino acid substitutions in the M molecule at positions 24 (Ala-->Thr) and 133 (Asp-->Asn).
Base Sequence↗
Identification of a second protein encoded by influenza C virus RNA segment 6.
Influenza C virus matrix protein (M1) is encoded by a spliced mRNA derived from RNA segment 6. Unspliced mRNA from this RNA segment, which has not been previously identified, can potentially encode a polypeptide that contains an additional 132 amino acids on the carboxy terminus of the M1 protein. Here the nucleotide sequences of RNA segment 6 of four influenza C strains, isolated in Japan between 1964 and 1988, were compared with the previously determined sequence of C/Ann Arbor/1/50. The results indicated that the deduced amino acid sequence of the carboxy-terminal 132 amino acid domain is conserved fairly well although it is more divergent than the M1 protein sequence. Examination of RNA segment 6-specific mRNAs also showed that unspliced mRNA is present, although in small quantities (approximately 13% of spliced mRNA), in influenza C virus-infected cells. To search for a polypeptide encoded by the unspliced mRNA, the extra carboxy-terminal domain was expressed in Escherichia coli as the glutathione S-transferase fusion protein, and rabbit immune serum was raised against the purified fusion protein. Immunoprecipitation experiments with this antiserum revealed that a previously unrecognized protein of apparent M(r) approximately 18,000, designated CM2, is synthesized in influenza C virus-infected cells.
Amino Acid Sequence↗
Genetic reassortment of influenza C viruses in man.
We reported previously that the antigenicity of the haemagglutinin-esterase (HE) glycoprotein of the human influenza C virus strain C/Nara/1/85 was indistinguishable from that of strain C/Nara/82. However, the ribonuclease T1-oligonucleotide map of total virion RNA of C/Nara/1/85 differed remarkably from the map of C/Nara/82, resembling instead the map of C/Nara/2/85, which has an HE antigenicity dissimilar to C/Nara/82 and C/Nara/1/85. This observation raised the possibility that C/Nara/1/85 might have arisen by reassortment from two viruses closely related to C/Nara/82 and C/Nara/2/85, respectively. Here, we compared the total nucleotide sequence of the HE gene and partial sequences of the other genes of C/Nara/1/85 with those of C/Nara/82 and C/Nara/2/85. The results suggest that C/Nara/1/85 has inherited HE and NP genes from a C/Nara/82-related virus and the PB2, PB1, PA, M and NS genes from a C/Nara/2/85-related virus.
Base Sequence↗
Search for point sources of ultrahigh energy gamma rays in the southern sky.
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Journal Article↗
Construction of an antigenic map of the haemagglutinin-esterase protein of influenza C virus.
Four different antigenic sites (A-1, A-2, B-1, B-2) have been identified previously on the haemagglutinin-esterase (HE) glycoprotein of influenza C/Ann Arbor/1/50 virus with seven monoclonal antibodies (MAbs). In this study we produced 30 additional anti-HE MAbs, nine of which demonstrated at least one of the following activities: haemagglutination inhibition, receptor-destroying enzyme inhibition, haemolysis inhibition, and neutralization (group A). The remaining had none of these activities (group B). These antibodies, and those previously isolated, were used to construct a more complete antigenic map of the HE molecule. Operational and topological analyses showed that a minimum of nine non-overlapping or partially overlapping antigenic sites were present on the HE protein, five recognized by group A MAbs (A-1 to A-5) and four by group B (B-1 to B-4). Among these antigenic sites, site A-5 was unique in that MAbs to this site inhibited the receptor-destroying activity without influencing the receptor-binding activity, which supports the idea that the sites responsible for these two functions are separate. It was also found that several group B MAbs were cross-reactive with host cell antigens.
Antibodies, Monoclonal↗
Induction of Fc gamma R-III (CD16) expression on neutrophils affected by paroxysmal nocturnal haemoglobinuria by administration of granulocyte colony-stimulating factor.
The inducibility of glycosyl-phosphatidylinositol (GPI)-anchored proteins on affected paroxysmal nocturnal haemoglobinuria (PNH) neutrophils (PMN) after both in vitro and in vivo stimulation was investigated. Fc gamma R-III (CD16), decay-accelerating factor (DAF/CD55) and 20 kD homologous restriction factor (HRF20/CD59) were demonstrated to be concurrently deficient on unstimulated defective PNH PMN. Upon in vitro stimulation with either N-formyl-methionyl-leucyl-phenylalanine (fMLP), zymosan-activated serum (ZAS), or recombinant human granulocyte colony-stimulation factor (G-CSF), neither CD16 nor CD55 expression was induced on defective PNH PMN. G-CSF was administered to two patients with PNH when their conditions were complicated by bacterial infections, or to prevent infections associated with the extraction of teeth or cataract surgery. CD16 expression was induced on the defective PNH PMN in both cases during the administration of G-CSF, but the expression of CD55 and CD59 was not. CD16, induced on the defective PNH PMN during the administration of G-CSF, was phosphatidylinositol-specific phospholipase C (PIPLC)-sensitive, implying that it had GPI-linkage to the membranes. The patients treated with G-CSF recovered from infection or evaded infection. These observations suggest that a deficiency of GPI-anchored proteins is not always seen in defective PNH blood cells, at least under certain stimulation conditions.
Antigens, CD↗
Detection of Mycoplasma hyorhinis in porcine eustachitis.
Pathologic study of the ear was performed on 179 young swine, ranging in age from 1 day to 18.6 weeks. Histologically, eustachitis was the most common and its inflammatory reaction appeared to precede otitis. Immunohistochemically, Mycoplasma hyorhinis (Mhr) antigens were detected on the luminal surface of the auditory epithelia in 19 of 179 cases (10.6%). All the cases, positive for Mhr antigens, were associated with an acute eustachitis. Ultrastructural examination of two piglets confirmed these immunohistochemical data. The present results indicate that Mhr may be a primary cause of acute eustachitis in young swine.
Aging↗
Deficiency of glycosyl phosphatidylinositol-anchored proteins in polymorphonuclear leukocytes from patients with paroxysmal nocturnal hemoglobinuria with low-grade hemolysis.
Paroxysmal nocturnal hemoglobinuria (PNH) is a disorder characterized by the deficiency of glycosyl phosphatidylinositol (GPI)-anchored proteins in blood cell membranes. We experienced a patient with PNH whose grade of hemolysis was reduced during the course of the disease. An analysis of the expression of GPI-anchored proteins on blood cells revealed typical PNH defects in polymorphonuclear leukocytes (PMN), but not in red blood cells (RBC). Accordingly, we investigated the expression of CD59 on RBC and of CD59 and CD16 on PMN in PNH patients, using immunofluorocytometry. We examined the cells of 8 PNH patients with different grades of hemolysis. PNH-affected PMN deficient in CD16 and CD59 were clearly demonstrated in every patient, including those with low-grade hemolysis. We conclude that demonstration of PNH-affected PMN deficient in GPI-anchored proteins has diagnostic values even in PNH patients with low-grade hemolysis.
Aged↗
Necrotic colitis associated with Entamoeba histolytica infection in a cat.
A 3-year-old Persian cat developed bloody diarrhoea. On histological examination, a marked necrotic colitis with a large number of invading protozoan parasites was observed. The protozoan was identified as Entamoeba histolytica by light and electron microscopy. This is the first report describing spontaneous amoebiasis in cats.
Animals↗