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Biomedical subjects

H Kamata

Publications and source records attributed to H Kamata.

At least 19 recordsLinked to original sources
PubMed1995

A novel insertion sequence (IS)-like element of the thermophilic bacterium PS3 promotes expression of the alanine carrier protein-encoding gene.

A novel insertion sequence (IS)-like element was found in the 5'-upstream region of the alanine carrier protein-encoding gene (acp) in the thermophilic bacterium PS3 chromosomal DNA. The sequence contained an open reading frame (ORF) encoding a polypeptide of 369 amino acids which revealed high similarity with ORFs from IS891 from the cyanobacterium Anabaena and IS1136 from Saccharopolyspora erythraea. The direction of transcription was the same as that of acp, and typical inverted and direct repeats characteristic of IS were found in both the 5' and 3' region of the ORF. Southern hybridization analysis of the chromosomal DNA revealed that multiple copies of the ORF sequence were contained in the PS3 genome. This element might well be a member of a new IS family including IS891 and IS1136, and we have designated this element IS1341. The analysis of acp expression in Escherichia coli cells indicated that IS1341 promotes the expression of acp.

Amino Acid Sequence↗
PubMed1995

Isolation of porcine adenovirus as a candidate of 5th serotype.

A strain of cytopathic virus, named strain TG/K79, was isolated from the brain of a newborn piglet, pure Hampshire breed, which died shortly after birth. The physicochemical property of virus was considered to be that of the family Adenoviridae. A significant difference between our isolated and 4 reference porcine adenoviruses was demonstrated by cross-seroneutralization test. Differences between TG/K79 and other porcine adenoviruses were also seen in electrophoretic patterns of viral DNA in agarose gel after digested by restriction endonucleases. Two SPF pigs, 2-month-old, experimentally infected via intranasal showed a fever and a hemorrhagic enteritis. A serological survey indicates that at least swine in the farm where the virus was isolated have been highly contaminated.

Adenoviridae Infections↗
PubMed1995

A follow-up study of patients with cervical cancer after resection, with special emphasis on the incidence of second primary cancers.

The causes of death in long-term survivors after resection of cervical cancer were investigated in a follow-up study of 375 women, focusing especially on the postoperative development of second primary cancers. The 5- and 10-year overall survival rates were 75.0 and 66.0%, respectively, in cases that showed frank invasion, 94.7 and 92.8%, respectively, in those showing microinvasion, and 96.2 and 96.2% respectively, in those showing carcinoma in situ. Multivariate analysis identified patient age and cancer stage at the time of diagnosis as separate factors prognostic for overall survival. During the observation period, 10 patients developed a second primary cancer, but no significantly elevated risk of developing a second primary cancer was demonstrated. However, during the same period, 20 patients also died of noncancerous disease, 9 of this number succumbing to acute myocardial infarction and/or heart failure. These results suggest that patients with cervical cancer may not have an increased risk of developing second primary cancer. It is felt that continued follow-up of long-term cervical cancer survivors should be pursued in order to prevent or arrest the development of noncancerous disease and/or second primary cancer, so that increased prolongation of survival can be achieved.

Adult↗
PubMed1994

Expression and characterization of an inositol 1,4,5-trisphosphate binding domain of phosphatidylinositol-specific phospholipase C-delta 1.

It was previously found that the 85-kDa protein purified from rat brain using an inositol 1,4,5-trisphosphate (Ins(1,4,5)P3)-immobilized matrix was the delta 1 isoform of phosphatidylinositol-specific phospholipase C (PLC). We expressed rat PLC-delta 1 in Escherichia coli as a fusion protein with glutathione S-transferase, and found that the bacterial lysate shows a significant amount of Ins(1,4,5)P3 binding. The lysate was applied to Ins(1,4,5)P3-immobilized column chromatography and the eluate with 2 M NaCl solution containing only a 100-kDa protein showed high Ins(1,4,5)P3 binding. The lysate was also purified to near homogeneity using a glutathione-Sepharose 4B affinity system. Bacterially-expressed enzyme thus purified showed essentially the same inositol phosphate binding characteristics as the brain-derived enzyme. PLC-delta 1 consists of the amino-terminal nonconserved region and two well-conserved regions among isozymes, designated as X and Y, which are thought to constitute a catalytic core of the enzyme. Using a combination of deletion mutants and proteolytic products of the enzyme, we were able to locate an Ins(1,4,5)P3 binding domain in the molecule. Deletion of 223 residues from the amino terminus completely abolished the binding activity, while deletion of X region only partially inhibited the binding and deletion of Y region did not affect the binding. A 76-kDa proteolytic product of the expressed PLC-delta 1 which lacked 60 amino acids at the amino terminus showed a minimal Ins(1,4,5)P3 binding activity. A peptide consists of 14 amino acids corresponding to residues 30-43 of PLC-delta 1, which contains 6 basic amino acids, binds to an Ins(1,4,5)P3-immobilized matrix. Moreover, Ins(1,4,5)P3 binding was blocked by phospholipid vesicles containing phosphatidylinositol 4,5-bisphosphate. These results, taken together, indicate that the amino-terminal domain of PLC-delta 1 is important for the binding of both Ins(1,4,5)P3 and phosphatidylinositol 4,5-bisphosphate.

Amino Acid Sequence↗
PubMed1994

Effect of immune serum, an antibiotic, and a corticosteroid used alone or in combination on experimental leptospirosis in Mongolian gerbils (Meriones unguiculatus).

We studied the effects of immune sera, an antibiotic, and a corticosteroid used alone or in combination on leptospira infection in Mongolian gerbils (Meriones unguiculatus). The results suggest that the combined used of immune serum and corticosteroid (pledonizoron: PZ) inhibits the effects of serum and the marked effects of antibiotic (procaine penicillin-G: PC-G) on leptospirosis. PZ had no effects and rather shortened the survival period. PZ did not affect the effects of PC-G when used in combination. These results suggest that treatment of leptospirosis with corticosteroids requires special caution.

Adrenal Cortex Hormones↗
PubMed1994

Protective effects of serum thymic factor to Leptospira interrogans serovar Copenhageni infection in Mongolian gerbils.

The susceptibility to Leptospira interrogans serovar copenhageni in Mongolian gerbils treated with 10 micrograms of serum thymic factor (FTS) 1 day before infection was examined. Susceptibility of gerbils treated 5 times with 10 micrograms of FTS was also investigated. Mortality of FTS-treated gerbils was significantly lower than that of controls when small challenge doses were used. To analyse the FTS-induced resistance to leptospiral infection, natural killer (NK) cell activity and macrophage activity were studied. Macrophage activity was unaltered but NK cell activity was enhanced in FTS-treated gerbils, with or without leptospiral infection. Since no side-effects of FTS were observed, this compound should be considered for the treatment of leptospirosis.

Animals↗
PubMed1994

The propagation of a porcine hemagglutinating encephalomyelitis virus in swine kidney cell cultures.

An established cell line, KSEK6, derived from swine embryo kidney proved to be a suitable host for the propagation of a hemagglutinating encephalomyelitis virus, strain 67N. Infected cells showed clear cytopathic effect as early as 24 hours incubation at 37 degrees C. Plaques easily visible to the naked eye were also produced under agar overlay medium. The infective titer of 3rd passage level in the cells was in the order of 10(8) PFU per ml. Detecting antibodies against this virus strain in swine sera was considered to be more accurate by neutralization test than by hemagglutination inhibition.

Animals↗
PubMed1993

Inhibitory effect of NaN3 on the F0F1 ATPase of submitochondrial particles as related to nucleotide binding.

The inhibitory effects of NaN3 on the F0F1 ATPase of beef heart submitochondrial particles were investigated. It was shown that NaN3 inhibited the ATPase activity only in the presence of ATP or ADP and the inhibition proceeded slowly. Analysis of the time-course of the inhibition process lead to a conclusion that an ATP binding site which has an apparent Kd of 14.0 +/- 8.7 microM is responsible for the increase of NaN3 sensitivity. This value agreed well with the low Km of ATP hydrolysis characterized before (Muneyuki, E., and Hirata, H. (1988) FEBS Lett. 234, 455-458) and in the range of so-called bi-site catalysis. The same conclusion was derived as for isolated F1 ATPase. From similar analysis, the Kd of this site for ADP was deduced to be 1.34 +/- 0.45 microM, which also agreed with that reported by Pedersen (Pedersen, P.L. (1975) Biochem. Biophys. Res. Commun. 64, 610-616) and also in the same range as reported for the low Km of ATP synthesis by activated submitochondrial particles. These results suggest that hydrolysis through the low Km mode of ATPase reaction leads the enzyme NaN3 sensitive form and this reaction cycle corresponds to the low Km mode of ATP synthesis.

Adenosine Diphosphate↗
PubMed1993

Infection of reovirus type 3 in Mongolian gerbils (Meriones unguiculatus)--lesions in pancreas and brain.

Gerbils were inoculated with reovirus type 3 (Abney strain), and the pancreas, brain and other organs histopathologically evaluated. Male Mongolian gerbils (Meriones unguiculatus) aged 5-10 days (newborn, 9 animals), 4 weeks (juvenile, 5 animals), and 12 weeks (adult, 5 animals) were used. Gerbils inoculated intraperitoneally with the virus were sacrificed 3, 5, 7, or 10 days later. Tissues were observed by light and electron microscopy. The pancreas of newborns showed inflammatory edema with infiltrates of neutrophilis and mononuclear round cells, degranulation of acinar cells and dissociation of lobules and acini with necrosis at 3 days or later after inoculation but not degeneration of pancreatic islets. Brains of newborns had necrosis of neurons and aggregation of microglial cells in the brain stem and cerebral hemisphere. Azurophilic inclusion bodies were seen in the cytoplasm of some neurons. In electron micrographs, virus particles (60-80 nm in diameter) were observed around the nucleus of neurons in the brain stem. No changes were observed in the juvenile and adult gerbils.

Animals↗
PubMed1993

Expression in baculovirus vector system of the nucleocapsid protein gene of rinderpest virus.

The rinderpest (RV) nucleocapsid (NP) gene segment was inserted into the genome of Autographa californica nuclear polyhedrosis virus (AcNPV) adjacent to the polyhedrin promoter. The expression of NP protein in Sf9 cells was confirmed by indirect immunofluorescence and by Western blotting analysis with monoclonal antibodies. Recombinant RV-NP protein was purified by ultracentrifugation on a sucrose density gradient, and used as an antigen for an enzyme linked immunosorbent assay to detect anti RV-NP antibody. Both IgM and IgG antibodies against RV-NP were detected in the sera of rabbits infected with the L strain of RV. The pattern of development of IgG anti RV-NP antibody closely correlated with that of virus neutralizing antibody. In rabbits inoculated with recombinant vaccinia virus expressing RV-H gene (RRV-H), anti RV-NP was not detected. The results indicated that the baculovirus vector system can be used for the preparation of the diagnostic antigen of rinderpest as well as to distinguish between natural infection and vaccination with RRV-H.

Animals↗
PubMed1993

Comparison of the pathogenicity of rinderpest virus in different strains of rabbits.

Pathogenicity of the lapinized Nakamura-III (L) strain of rinderpest virus (RPV) was examined in four strains of rabbits consisting of two inbred strains (NW-NIBS and DUY-NIBS) and two outbred strains maintained in closed colony (NW-NIBS and JW-NIBS) using a marmoset lymphoblastoid cell line, B95a cell-passaged virus and tissue homogenates of virus-infected rabbits. The cell culture virus was found to maintain virulence for rabbits of both closed colony and inbred NW-NIBS strain similar to the homogenate virus. Among the strains investigated, inbred NW-NIBS strain showed the highest susceptibility to RPV. Thus experimental model in an inbred rabbit using cell culture virus became useful.

Animals↗
PubMed1992

Primary structure of the alanine carrier protein of thermophilic bacterium PS3.

Purified alanine carrier proteins were cleaved into peptides either chemically after solubilization in 1,1,1,3,3,3-hexafluoro-2-propanol or proteolytically with lysylendopeptidase. From the amino acid sequence analyses of these peptides, we synthesized a DNA probe and utilized it for successful cloning of a gene encoding the alanine carrier protein (acp gene). The 5'-flanking region was determined by an inverse polymerase chain reaction, and an open reading frame consisting of 1,335 nucleotides was found. The amino acid sequence deduced from the open reading frame consists of 445 amino acids, and all the partial amino acid sequences determined are included in the sequence. Although the calculated M(r) of 47,803 is significantly larger than the apparent M(r) of 42,500 as reported previously (Hirata, H., Kambe, T., and Kagawa, Y. (1984) J. Biol. Chem. 259, 10653-10656), an in vitro translation experiment revealed that the product of the acp gene migrates at a position coinciding with that of the purified alanine carrier. Hydropathy analysis suggests that the protein contains at least 8 hydrophobic segments presumably spanning membrane. A homology search on a database reveals relatively high scores of homology with either the Escherichia coli melibiose carrier or the human Na+/glucose symporter, particularly in the region from Leu246 to Glu286. Furthermore, the region also reveals low but significant similarities to other Na(+)-coupled symporters.

Amino Acid Sequence↗
PubMed1992

Susceptibility of a line of dolphin kidney cell culture to several herpesviruses.

A cell line was established from cell cultures of kidney cortex of a pantropical spotted dolphin, Stenella attenuate. The replication of 6 strains of herpesviruses was studied in the cells. Five strains of them, herpes simplex virus type I and type II, equine rhinopneumonitis virus, infectious bovine rhinotracheitis virus and Aujeszky's disease virus, were grown fairly well in showing clear cytopathic effects and plaques under agar overlay medium.

Animals↗
PubMed1992

Partial purification and reconstitution of inositol 1,4,5-trisphosphate receptor/Ca2+ channel of bovine liver microsomes.

The binding of inositol-1,4,5-trisphosphate [Ins(1,4,5)P3] to bovine liver microsomes was characterized. The Ins(1,4,5)P3 receptor of the microsomes was solubilized by 1% Triton X-100 and purified by sucrose density gradient, Heparin-Sepharose, DEAE-Toyopearl, ATP-Agarose, and Ins(1,4,5)P3-Sepharose column chromatographies. More than 1,000-fold enrichment of the Ins(1,4,5)P3-binding activity was achieved. Kd values of the binding activity were 2.8 nM in microsomes and 3.0 nM in the partially purified receptor, respectively, and the binding activity was optimal in the medium containing 100 mM KCl and at pH between 7.5 and 8.5. The presence of Ca2+ failed to inhibit the binding. Phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PtdIns), and phosphatidylinositol-4-monophosphate [PtdIns(4)P] showed no effect on the Ins(1,4,5)P3 binding. However, soybean phospholipids asolectin and phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] strongly inhibited the binding activity. PtdIns(4,5)P2 inhibited the activity competitively with a half-maximal inhibitory concentration of 30 micrograms/ml. The partially purified Ins(1,4,5)P3 receptor was reconstituted into proteoliposomes. Fluorescence measurements using Quin 2 indicated that Ins(1,4,5)P3 stimulated Ca2+ influx into the proteoliposomes. The EC50 of Ins(1,4,5)P3 on Ca2+ influx was 50 nM. This result strongly suggest that Ins(1,4,5)P3 binding protein of liver microsomes acts as a physiological Ins(1,4,5)P3 receptor/Ca2+ channel.

Animals↗