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Biomedical subjects

T Mikami

Publications and source records attributed to T Mikami.

At least 289 records · Page 16Linked to original sources
PubMed1997

Adhesion of insect cells expressing the feline herpesvirus type 1 hemagglutinin (gD) to feline cell lines.

Feline herpesvirus type 1 (FHV-1) gD-expressing Sf9 cells adhered to two feline cell lines, but not to the porcine, bovine, or canine cell lines tested. In addition, this adhesion activity was inhibited by a monoclonal antibody against FHV-1 gD. These results showed that the FHV-1 gD might bind to a specific-molecule(s) on the surface of feline cell lines. We discussed a possible importance of the FHV-1 gD in host cell restriction to FHV-1 infection.

Alphaherpesvirinae↗
PubMed1997

Recombinant viral vector vaccines for the veterinary use.

Recently, genetically engineering using recombinant DNA techniques has been applied to design new viral vaccines in order to reduce some problems which present viral vaccines have. Up to now, many viruses have been investigated for development of recombinant attenuated vaccines or live viral vectors for delivery of foreign immunogenic antigens. In this review, we introduced three kind of viruses; herpesviruses, vaccinia viruses, and adenoviruses, which have best widely been studied as recombinant vaccines or delivery vaccines for the veterinary use.

Animals↗
PubMed1997

Generation of monoclonal antibodies against a feline CD antigen (CD4) expressed by a recombinant baculovirus.

We attempted to establish a system to generate monoclonal antibodies (mAbs) recognizing CD antigens on lymphocytes of domestic animals using the expressed CD antigens by a baculovirus expression system. For this purpose, we selected feline CD4 (fCD4) antigen and expressed it in an insect cell line (Sf9 cells). To obtain mAbs, BALB/c mice were immunized with feline peripheral blood mononuclear cells (fPBMCs) or Sf9 cells expressing the fCD4 (Sf-fCD4 cells), and then hybridomas secreting antibodies were screened by indirect immunofluorescence assay against the opposite antigens of Sf-fCD4 cells or fPBMCs, respectively. Five mAbs recognizing the fCD4 were obtained in total. The system established here might be useful to obtain mAbs recognizing CD antigens of domestic animals.

Animals↗
PubMed1997

Expression of the nucleocapsid protein gene of the canine distemper virus.

We constructed a cDNA clone of canine distemper virus (CDV) encoding an entire nucleoprotein (NP) gene, by means of the reverse transcription-polymerase chain reaction (RT-PCR). The cloned NP gene was inserted into the eucaryotic expression vector, pRVSV. After transfection of the plasmid into Vero cells, we examined the expression of CDV-specific NP antigen by means of indirect immunofluorescence assay (IFA) and Western blotting, using various antibodies against NP of CDV and an antiserum against NP of measles virus. The CDV-NP specific antigen was detected in the nuclei of the cells transfected with pRV-ON, by means of IFA with antibodies specific to the NP.

Animals↗
PubMed1997

Identification and DNA sequence analysis of the Marek's disease virus serotype 2 gene homologous to the herpes simplex virus type 1 glycoprotein H.

Marek's disease virus (MDV) serotype 2 (MDV2) gene homologous to the glycoprotein H (gH) gene of herpes simplex virus type 1 was identified and sequenced. The predicted region encoding for the MDV2 gH gene was 2436 nucleotide and the primary translation product was 812 amino acids with a molecular weight of 89.4 kDa. The protein encoded by MDV2 gH gene has a number of features characteristic of a membrane-associated glycoprotein. First, there are 9 potential N-linked glycosylation sites and 11 cysteine residues, and 6 of the sites and 8 of the residues were conserved among all of the three MDV serotypes. Second, this protein had N-terminal and C-terminal hydrophobic regions, which were a signal sequence and a transmembrane-anchor domain, respectively. From the northern blot analysis, it was suggested that a transcript encoding MDV2 gH and a poly-cistronic transcript encoding MDV2 thymidine kinase, gH, and possibly other genes of downstream on this strand existed. Alignment of the amino acid sequences of the gH homologues among the three MDV serotypes showed 57.5% (MDV1 and MDV2), 56.2% (MDV1 and HVT), and 50.1% (MDV2 and HVT) identities.

Amino Acid Sequence↗
PubMed1997

Apoptosis of murine hepatocytes induced by high doses of galactosamine.

Apoptosis induced by high doses of Galactosamine (GalN) was investigated in mice hepatocytes in vivo. In mice intraperitoneally (i.p.) treated with GalN 3 g/kg, the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells were first observed at 6 hr postadministration (PA). Both acidophilic bodies in hematoxylin and eosin (HE)-stained sections and TUNEL-positive cells were markedly found at 24 hr PA. At 48 hr PA, cellular degeneration and necrosis of hepatocytes were prominently observed, and TUNEL-positive cells were scarcely found. In the mice ip treated with GalN 1.5 g/kg, the lesion was milder than that in those treated with GalN 3 g/kg. Acidophilic bodies and TUNEL-positive cells were scarcely found at 24 hr PA, whereas they were markedly seen at 48 hr PA. In addition, a ladder-like DNA fragmentation pattern by agarose gel electrophoresis was observed most remarkably at 24 hr PA with GalN 3 g/kg and at 48 hr PA with GalN 1.5 g/kg, and less distinctly at 48 hr PA with GalN 3 g/kg. On the other hand, sGOT and sGPT activities increased prominently at 48 hr PA with GalN 3 g/kg. These results suggest that the cell death induced by high dose of GalN may be caused by apoptosis, and subsequently by necrosis in vivo.

Alanine Transaminase↗
PubMed1997

High prevalence of the CagA-positive Helicobacter pylori strains in Japanese asymptomatic patients and gastric cancer patients.

BACKGROUND: Several studies have shown that infection of Helicobacter pylori strains possessing cagA is associated with atrophic gastritis and gastric cancers. METHOD: In 58 pairs of early gastric cancer patients and sex- and age-matched controls, isolated H. pylori strains were tested for possession of cagA. The presence of atrophic gastritis was also examined. RESULTS: Proportions of cagA-positive strains were 100% in cancer patients and 92.3% in controls. Atrophic gastritis was seen in 96.7% and 95.8% of cancer and control patients in whom cagA-positive strains (NS) were detected. However, it was seen in only 20% of H. pylori-negative control patients (P < 0.01). CONCLUSIONS: The present results do not suggest any specific association between cagA-positive strains and gastric cancer. However, frequent prevalence of cagA-positive strains might be associated with the high incidence of atrophic gastritis in Japanese populations.

Adult↗
PubMed1997

[Familial astrocytoma associated with von Recklinghausen's disease: report of two cases].

Two cases of astrocytoma associated with von Recklinghausen's disease (neurofibromatosis type; NF-1) were reported. The first case wes a 60-year-old man who had been diagnosed as von Recklinghausen's disease on the basis of skin findings. Magnetic resonance imaging (MRI) showed a tumor in the left temporal lobe. Partial removal was performed with neuronavigator, and because of the existence of Rosenthal fiber the histological diagnosis was pilocytic astrocytoma. Radiation therapy was performed. The second case was a 6-year-old boy suffering from headache and left hemiparesis including his face. MRI showed a tumor with a cyst in the right thalamus and obstructive hydrocephalus. Initially CT-guided stereotactic biopsy was performed, and the histological diagnosis, on the basis of increased cellularity, pleomorphism and nuclear atypia without necrosis or vascular proliferation, was anaplastic astrocytoma. Radiation and chemo-immuno therapy were carried out after V-P shunt. It is well known that von Recklinghausen's disease (NF-1) is often associated with optic glioma (5-36%). In the literature, the glioma seldom occurs in other parts of the brain, supratentorial glioma especially is rare. Only two familial cases of supratentorial glioma associated with von Recklinghausen's disease have been reported. The prognosis of supratentorial glioma associated with NF-1 was poor in these reports. In this paper, the diagnostic and therapeutic problems are discussed.

Astrocytoma↗
PubMed1997

[Intraoperative and follow-up color Doppler echocardiography for evaluating the surgical results of aortic valvuloplasty in a patient with bicuspid aortic valve].

A 21-year-old man underwent aortic valvuloplasty for aortic regurgitation due to bicuspid aortic valve. After the initial procedure for valvuloplasty of the anterior cusp, transesophageal color Doppler flow imaging revealed a significant regurgitant jet directed posteriorly as observed preoperatively. After an additional valvuloplastic procedure for the anterior cusp, the size of the regurgitant signal was reduced and directed to the center of left ventricular outflow tract. The surgery was then completed. On the 5th postoperative day, an aortic regurgitant murmur reappeared and color Doppler echocardiography showed a mild but significant regurgitant jet directed toward the interventricular septum, which may have been due to contraction of the anterior cusp treated by valvuloplasty. Aggravation of the aortic regurgitation in the early stage after plastic surgery is important and requires consideration in the intraoperative assessment.

Adult↗
PubMed1997

Influence of blood substrate levels on myocardial kinetics of iodine-123-BMIPP.

UNLABELLED: To evaluate the influence of blood substrate levels on myocardial uptake of 123I-labeled beta-methyl-iodophenyl-pentadecanoic acid (BMIPP), we examined the correlation between myocardial BMIPP uptake and blood levels of free fatty acid (FFA), glucose, insulin, triglyceride and total cholesterol. METHODS: In 180 patients, venous blood samples were obtained, and the early and late myocardial uptakes (MU15 and MU150) were determined on planar images at 15 and 150 min after injection at rest, respectively, and the clearance rate of BMIPP from the myocardium was calculated. Dynamic SPECT with BMIPP, PET with [18F]fluoro-deoxyglucose and determination of myocardial carnitine contents were performed in 15, 1 and 3 patients, respectively. RESULTS: In the 180 patients, MU15 correlated with blood insulin (r = 0.22, p = 0.005) and FFA (r = -0.19, p = 0.02) levels, whereas MU150 did not correlate with blood levels of any variables that were measured (p > 0.05). The clearance rate correlated with blood insulin (r = 0.28, p < 0.001), glucose (r = 0.17, p = 0.03) and FFA (r = -0.40; p < 0.001) levels. The correlations were, however, weak, and five patients (2.8%) with no myocardial BMIPP uptake, all of whom had anterior myocardial infaction, had no characteristics regarding the blood substrate levels. Although dynamic SPECT demonstrated rapid myocardial extraction of BMIPP in 13 patients with myocardial BMIPP uptake, it demonstrated no myocardial BMIPP extraction in two patients with no myocardial BMIPP uptake. One of the five patients with no myocardial BMIPP uptake showed increased myocardial [18F]fluorodeoxyglucose uptake and decreased myocardial carnitine content. CONCLUSION: The influence of blood substrate levels on myocardial BMIPP uptake is not very significant, although high serum FFA levels may be associated with slow clearance of BMIPP from the myocardium. The complete absence of myocardial BMIPP uptake is not rare and may not be associated with changes in blood substrate levels or early back diffusion of BMIPP.

Adolescent↗
PubMed1997

Phylogenetic analysis of feline immunodeficiency virus isolated from cats in Taiwan.

Feline immunodeficiency virus was isolated from four cats in Taiwan. The isolates were designated TI-1, TI-2, TI-3 and TI-4. Each was isolated from PBMCs following co-cultivation of PBMCs with a feline T-lymphoblastoid cell line (MYA-1 cells). However, the Taiwanese isolates did not grow in a feline kidney cell line (CRFK cells). The nucleotide sequences of the V3-V5 region of the envelope gene of the Taiwanese isolates were determined and compared with those of previously described isolates. Phylogenetic analysis of this region indicates that Taiwanese isolates belong to subtype C.

Amino Acid Sequence↗
PubMed1997

Cardiac sympathetic neuropathy and effects of aldose reductase inhibitor in streptozotocin-induced diabetic rats.

UNLABELLED: Cardiac autonomic neuropathy can be a cause of sudden death in patients with diabetes mellitus. Clinical evaluation methods for diabetic cardiac sympathetic neuropathy have not been established. Using 125I-metaiodobenzylguanidine (MIBG) and streptozotocin (STZ)-induced diabetic rats, we evaluated cardiac sympathetic neuropathy and the effects of aldose reductase inhibitor (ARI). METHODS: Myocardial MIBG uptake was measured 4 hr after injection in the following groups: control rats, rats treated with insulin or ARI (epalrestat, 100 mg/kg/day) from immediately to 4 wk after STZ injection and rats treated with insulin or ARI from 4-8 wk. Myocardial MIBG distribution and norepinephrine content were evaluated in the control and diabetic rats with or without ARI therapy started immediately after STZ injection. RESULTS: Myocardial MIBG uptake was significantly lower in diabetic rats than in control rats; the reduction was marked in the subendocardial myocardium. Myocardial norepinephrine content was increased significantly in diabetic rats compared with control rats. Decreased MIBG uptake and increased norepinephrine content in diabetic myocardium were completely prevented by insulin therapy started immediately after STZ injection and partially, but significantly, by ARI administered from immediately after STZ injection. Heterogeneous MIBG distribution also disappeared with the ARI therapy. In contrast, diabetic rats treated with insulin or ARI therapy started 4 wk after STZ injection showed no improvement in MIBG uptake. CONCLUSION: These results suggest that MIBG abnormalities observed in diabetic rats may reflect diabetic cardiac sympathetic neuropathy independently of cardiomyopathy, nephropathy or coronary heart disease secondary to diabetes and that MIBG imaging may be useful for clinical assessment of cardiac sympathetic neuropathy.

3-Iodobenzylguanidine↗
PubMed1997

Effects of cilazapril and verapamil on myocardial iodine-125-metaiodobenzylguanidine accumulation in cardiomyopathic BIO 53.58 hamsters.

UNLABELLED: Sympathetic nervous system activation is important in the pathophysiology of congestive heart failure. However, little about how the treatment for heart failure may influence myocardial sympathetic nervous activity has been established. In this study, we evaluated effects of cilazapril (CLZ) and verapamil (VER) on myocardial sympathetic nervous activity in cardiomyopathic BIO 53.58 hamsters using [125I]metaiodobenzylguanidine ([125I]MIBG). METHODS: We used BIO 53.58 hamsters aged 3, 6 and 10 mo and age-matched normal F1b hamsters. We divided BIO 53.58 hamsters into untreated, CLZ- and VER-treated groups. We measured myocardial [125I]MIBG uptakes and norepinephrine concentrations and evaluated the extent of fibrosis and the distribution of [125I]MIBG. RESULTS: The myocardial [125I]MIBG uptake was significantly lower in BIO 53.58 hamsters aged 6 and 10 mo than in age-matched F1b hamsters. Myocardial [125I]MIBG uptake was significantly correlated to myocardial norepinephrine concentration in BIO 53.58 hamsters. Myocardial [125I]MIBG uptake was significantly higher in both of the treated groups than in the untreated group. The extent of myocardial fibrosis was significantly lower in both of the treated groups than in the untreated group. The myocardial [125I]MIBG uptake showed a significant inverse correlation with the extent of fibrosis. Myocardial [125I]MIBG distribution was highly heterogeneous in the untreated BIO 53.58 hamsters, whereas it was homogeneous in the F1b hamsters aged 6 mo and the treated BIO 53.58 hamsters. CONCLUSION: In BIO 53.58 hamsters, myocardial [125I]MIBG uptake decreased with the progression of cardiomyopathy, and the decreased uptake was improved by treatment with CLZ and VER. Thus, myocardial [125I]MIBG uptake can reflect the effects of treatment on cardiomyopathy, as well as the progression of cardiomyopathy.

3-Iodobenzylguanidine↗
PubMed1997

[Rotavirus-associated gastroenteritis in adults].

The human rotavirus in adult diarrhea cases was evaluated in 109 cases during 12 months, 1996. Rotavirus antigen was identified, using the ELISA technique, in stool samples in 23 cases (21%). We arranged the positive cases as rotavirus-associated gastroenteritis in adults and analyzed them. Fourteen out of them (74%) occurred from June through September. Fourteen cases (74%) needed to be hospitalized. Colonoscopy revealed some inflammatory changes in 9 out of 16 cases (47%). Most of symptom was watery diarrhea, but bloody diarrhea was observed in 6 cases (32%). It was suggested we should introduce a concept of rotavirus-associated gastroenteritis in adults.

Adolescent↗
PubMed1996

Mutagenicity of dihydroxybenzenes and dihydroxynaphthalenes for Ames Salmonella tester strains.

The mutagenicity of 3 dihydroxybenzene (DHB) and 9 dihydroxynaphthalene (DHN) isomers was examined by using 5 different Ames Salmonella mutagenicity tester strains in the presence and absence of phenobarbital and 5,6-benzoflavone-treated rat liver S9-mix. Of the 3 DHB isomers, 1,4-DHB (hydroquinone) was mutagenic, and of the 9 DHN isomers, 1,3-DHN (naphthoresorcinol), 1,4-DHN (hydronaphthoquinone), 1,6-DHN and 1,7-DHN were mutagenic. Mutagenicity of all the compounds tested was observed in the absence of S9-mix, while 1,4-DHN and 1,6-DHN were also mutagenic in the presence of S9-mix. The mutagenicity of 1,4-DHB and 1,4-DHN for TA104, which is a strain sensitive to oxidative mutagens, was almost completely or partially inhibited by superoxide dismutase (SOD) and/or catalase, indicating the involvement of activated oxygen species in mutagenesis. Furthermore, from the finding that the 4 DHNs were mutagenic for TA2637, the strain sensitive to frameshift mutagens, it is possible that the mutagenicity of DHNs for S. typhimurium was also attributable to DNA adducts that form with quinones and/or semiquinones through oxidation of DHNs. The mutagenicity of 1,3-DHN, which showed the largest number of revertants in strains TA100, TA98, TA2637 and TA104, was greatly decreased, when their pKM101 plasmid-deficient strains, TA1535, TA1538, TA1537 and TA2659 were used. This observation suggests that an SOS repair system was involved in the mutagenesis of 1,3-DHN for S. typhimurium.

Animals↗
PubMed1996

A duplicated sequence in sugarbeet mitochondrial transcripts is differentially edited: analysis of orfB and its derivative orf324 mRNAs.

RNA editing of the duplicated sequences was investigated in the transcripts of orfB and orf324 genes from sugarbeet mitochondria. The orf324 shares the first 59 bp of the reading frame and 321 bp upstream sequence with orfB. Two cytidine-to-uridine editing sites were found in orfB, but the corresponding cytidine residues remained unchanged in the transcripts of orf324. In the vicinity of the non-edited cytidine residues within the shared sequence element of orf324 were identified three point mutations that may abolish orf324 editing. Our results also suggest that selection of editing sites depends on primary sequence.

Amino Acid Sequence↗