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Biomedical subjects

T Miyazawa

Publications and source records attributed to T Miyazawa.

At least 235 records · Page 13Linked to original sources
PubMed1995

Phylogenetic analysis of the long terminal repeat of feline immunodeficiency viruses from Japan, Argentina and Australia.

The nucleotide sequences of the long terminal repeat of five Japanese, five Argentine and three Australian isolates of feline immunodeficiency virus (FIV) were determined and compared with those of isolates previously described. The results revealed that the Japanese isolates were found to cluster with nucleotide sequence similarity of 95.6%-99.4%. The Australian isolates also clustered with nucleotide sequence similarity of 97.2%-99.4%. The Argentine isolates formed two groups; the LP9 isolate is closely related to the Japanese isolates, whereas the LP1, LP3, LP20 and LP24 isolates are distant from both the Japanese and Australian isolates. From these results, FIV can be divided into three groups, namely: (I) the Californian, Australian and British isolates; (II) the Japanese isolates and one Argentine LP9 isolate; (III) the other Argentine isolates.

Animals↗
PubMed1995

Genotyping of isolates of Taylorella equigenitalis from thoroughbred brood mares in Japan.

Profiles of the genomic DNA of 104 strains of T. equigenitalis isolated from brood mares with contagious equine metritis in Hokkaido during the breeding seasons from 1980 to 1993, as well as those of five strains (SS28, EQ56, EQ59, EQ70 and HH139) previously isolated in Japan were examined after restriction digestion and crossed-field gel electrophoresis. These profiles were essentially identical to each other and the various isolates and strains appeared to have a common genotype, designated 'genotype J', with respect to two restriction enzymes, ApaI and NotI. These results suggest a common source for all these isolates obtained over the course of more than 10 years in Japan.

Animals↗
PubMed1995

Chemiluminescence detection of mono-, bis-, and tris-hydroperoxy triacylglycerols present in vegetable oils.

A reliable method was needed to analyze molecular species of oxidized vegetable oils. In order to accomplish this goal, mono-, bis-, and tris-hydroperoxides (Mono-OOH, Bis-OOH, and Tris-OOH, respectively) of triacylglycerols formed during autoxidation and photosensitized oxidation of oils were determined by reversed-phase high-performance liquid chromatography in combination with chemiluminescence detection (CL-HPLC). Mono-OOH was the major species (96% of total hydroperoxides) in trioleoylglycerol [peroxide value (PV) 0.16 meg/kg], and Bis-OOH and Tris-OOH showed prolonged accumulation with photooxidation. This profile was confirmed in photooxidation of trilinoleoylglycerol and trilinoleoylglycerol. Soybean oil (PV 6 meq/kg) contained Mono-OOH oleoyl-linoleoylglycerol as the main peroxidic molecular species (50% of total hydroperoxides). Mono-OOH trilinoleoylglycerol was the principal species (61% of total hydroperoxides) in safflower oil (PV 5 meq/kg), and Mono-OOH oleoyl-oleoyl-linoleoylglycerol was the representative species (66% of total hydroperoxides) in olive oil (PV 3 meq/kg). The CL-HPLC method, which is specific for the detection of hydroperoxides, should prove useful in studies of triacylglycerol oxidation in foods and vegetable oils.

Chromatography, High Pressure Liquid↗
PubMed1995

A synaptic vesicle-associated protein (SVP-38) as an early indicator of delayed neuronal death.

Sixteen gerbils were subjected to 5 min of forebrain ischemia. Their brains were processed for immunohistochemical staining using monoclonal antibodies against a synaptic vesicle-associated protein 38 (SVP-38) and microtubule-associated protein 2 (MAP2) after recirculation times of 10 min, and 1, 4, and 7 days. After 10 min recirculation, SVP-38 immunoreactive dots were observed only in the CA1 region of the hippocampus. After 1 day recirculation, SVP-38 immunostaining was diffuse and weak throughout the hippocampus, despite preservation of MAP2 immunoreactivity. After 4 and 7 days recirculation, SVP-38 immunoreactivity had been restored in the whole hippocampus, despite the complete loss of MAP2 immunoreactivity due to delayed neuronal death. Our results demonstrate an immediate and significant change in the immunoreactivity of a synaptic vesicle-associated protein at the beginning of the process of delayed neuronal death. Thus, changes in the immunoreactivity of synaptic vesicle-associated proteins such as SVP-38 appear to be one of the earliest indicators of the onset of neuronal death.

Animals↗
PubMed1995

Safety and pharmacokinetics of iotrolan in hysterosalpingography. Retention and irritability compared with Lipiodol.

RATIONALE AND OBJECTIVES: The authors compared the safety and pharmacokinetics of Iotrolan (water-soluble) in hysterosalpingography (HSG) with those of Lipiodol (oil-soluble). METHODS: Iotrolan and Lipiodol were administered intraperitoneally at doses of 100 mg iodine/kg to female rabbits. Retention in the body was investigated by x-ray imaging, plasma kinetics, and urinary and fecal excretion. Irritability in the abdomen was investigated by histologic examination. RESULTS: Iotrolan was entirely excreted into the urine within 2 days after administration. Conversely, Lipiodol was excreted into the urine, had a half-life of 50 days, and was retained for more than 21 days in the abdomen. Iotrolan induced no inflammatory reaction in the abdomen, whereas Lipiodol induced a marked abdominal inflammatory reaction, including granuloma formation. Iotrolan had no effect on iodine concentration in the thyroid; Lipiodol increased iodine concentration significantly. CONCLUSIONS: Iotrolan, which is a water-soluble and nonionic dimeric contrast medium, has potential greater safety for use in HSG than Lipiodol.

Abdomen↗
PubMed1995

Perfusion imaging of the brain by B-mode ultrasonography. An experimental study in rabbits.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the ultrasonic imaging of normal rabbit brain by using echocontrast enhancer to identify the brain tissue perfusion. METHODS: A solution of SH/TA-508 (containing microbubbles of mean size 2 to 4 microns; n = 4) was used for contrast enhancement of rabbit brain tissue and was administered through the left internal carotid artery. Contrast enhancement in the ipsilateral parietal area was examined by placing a 7.5-MHz transducer on the dura after a craniectomy. Throughout the experiment, we measured parameters including arterial blood pressure, arterial blood gases, and serum glucose and hematocrit levels. We investigated whether the administration of an echocontrast enhancer would be safe for the brain tissue (n = 4). RESULTS: After injection of 100 mg/mL SH/TA-508, contrast enhancement was clearly observed within approximately 1 second in the left hemisphere (especially in the left cerebral cortex) in all animals and disappeared within 3 seconds after the end of injection. All physiological parameters remained within the normal range throughout the experiment. No focal abnormalities were observed on hematoxylin-eosin staining of the brain tissue. CONCLUSIONS: Contrast enhancement was observed in the ipsilateral hemisphere with the administration of SH/TA-508. Contrast enhancement on B-mode brain imaging would be useful for real-time identification of brain tissue perfusion and should become a promising method for bedside clinical assessment of brain tissue perfusion.

Animals↗
PubMed1995

Seroepidemiological survey of feline retrovirus infections in cats in Taiwan in 1993 and 1994.

In order to investigate the prevalence of infections with three feline retroviruses feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and feline syncytial virus (FSV) in Taiwan, we collected a total of 75 blood samples from cats from veterinary hospitals, a breeding cattery and a homeless shelter in 1993 and 1994. We examined the presences of anti-FIV and FSV antibodies and FeLV-p27 antigen in these samples by the indirect immunofluorescence and/or enzyme-linked immunosorbent assays. All of the serum samples positive for FIV were obtained from homeless cats and the overall FIV positive rate was 4%. The overall positive rates of FSV and FeLV were 28% and 1.3%, respectively. From these results, together with previous seroepidemiological surveys by others, it was revealed that the prevalence of FIV and FeLV infections appeared to be lower in Taiwan than in the United States or Japan. In contrast, the prevalence of FSV infection in Taiwan was as high as that in Japan.

Animals↗
PubMed1995

Quantification of feline immunodeficiency virus (FIV) proviral DNA in peripheral blood mononuclear cells of cats infected with Japanese strains of FIV.

The polymerase chain reaction (PCR) method was applied for measurement of the proviral DNA copy number of feline immunodeficiency virus (FIV) in peripheral blood mononuclear cells (PBMC) of cats experimentally and naturally infected with FIV. In experimentally infected cats except one cat infected with the Petaluma strain, FIV-specific DNAs were efficiently amplified with the PCR method under the conditions used in this study. In the naturally FIV-infected cats, the specific DNAs were also amplified. We established a quantitative method for measurement of proviral DNA copy number in PBMC from cats infected with TM2-type of FIV strains, and found that the number was variable among the six cats examined, ranging from 10(4.0) to 10(5.7) copies per 10(5) PBMCs. This method can be applicable to cats naturally infected with FIV of TM2-type. Proviral DNA quantitation developed here could be useful as an additional parameter to evaluate the relationships among the proviral load, immune response and development of the clinical symptoms, and to monitor efficacy of antiviral therapy in vivo.

Animals↗
PubMed1995

Protoporphyric disorder in livers of broiler chickens.

Two cases of protoporphyrin (PP) disorder detected in a 60- and 65-day old female chicken were described. The gross lesions were restricted to the livers which were enlarged and dark green to black in color. Histologically, dark brown granules were found in hepatocytes, Kupffer cells, macrophages, sinusoids, bile canaliculi, and bile ducts. These granules, as seen in smears and sections of livers, were red under a fluorescence microscope and exhibited bright birefringence with a centrally located dark Maltese-cross by polarized light. Ultrastructurally, these granules consisted of aggregates of needle-like crystals in a radial arrangement. Fluorometrically, extracted level of PP in the affected liver was determined to be 390.6 micrograms per gram of wet tissue. Spectrofluorometric scans of liver extract and PP standard were almost identical.

Animals↗
PubMed1995

Establishment of carrier-state infection of a feline renal cell line with feline syncytial virus.

Although feline syncytial virus (FSV) is normally highly cytopathogenic in Crandell feline kidney cells, a non-cytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells 4 times. More than 90% of the persistently infected cells were positive for FSV antigen, and electron microscopy showed that the culture produced morphologically normal FSV. Virus from the carrier culture was infectious, however, the titer of the virus from the culture was lower than that from the cytocidally infected CRFK cells.

Animals↗
PubMed1995

Gastric mucosal phosphatidylcholine hydroperoxide increases during cold water-immersion restraint stress in rats.

To know the role of lipid peroxidation in the pathogenesis of stress-induced gastric mucosal lesions, we performed the present study. Both gastric mucosal lesions and gastric mucosal phosphatidylcholine hydroperoxides (PCOOH) levels during cold water-immersion restraint (CWIR) stress were measured by the chemiluminecence-HPLC method in Sprague-Dawley rats. Ulcer indices increased time-dependently during the stress. Gastric mucosal PCOOH levels also significantly increased and reached a peak level (250% of untreated level) after 2 hr of stress. These results suggest that lipid peroxidation may play an important role in the pathogenesis of gastric mucosal lesions induced CWIR stress.

Animals↗
PubMed1995

Susceptibility for hydroperoxide formation of phosphatidylcholine and phosphatidylethanolamine in liposomes.

To compare the peroxidative susceptibilities of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in liposomes, multilamellar vesicles (MLVs) were prepared with equimolar L-alpha-dilinoleoyl PC (DLPC) and L-alpha-dilinoleoyl PE (DLPE), and with soya PC and soya PE having a uniform constituent fatty acids. The hydroperoxide formation at 37 degrees C in the presence of a water-soluble radical initiator was examined by chemiluminescence-high-performance liquid chromatography (CL-HPLC), and the effect of heterogeneous distribution of PC and PE on peroxidation was investigated. No difference was found between the hydroperoxidation of PC and PE in MLVs systems, except that soya PC was more susceptible to peroxidation than soya PE in the L-alpha-dipalmitoyl PC (DPPC)-based liposomes. No correlation was found between the amount of phospholipids distributed in the external leaflet of MLVs and hydroperoxide formation. This result suggested that the unsaturation of constituent fatty acids in phospholipids is more important than the difference in the polar head group of phospholipids regarding their peroxidizabilities in liposomes.

Chromatography, High Pressure Liquid↗
PubMed1995

[Calvarial metastasis of cervical carcinoma showing the dural tail sign on magnetic resonance imaging].

A 42-year-old female was admitted to our department on 3 August, 1993 with a 3-month history of steadily enlarging subgaleal mass (3.2 x 3.0 cm) in the parietal region. She had been doing well following radiotherapy for cervical carcinoma of the uterus one year previously. Neurological examination on admission was negative. Axial T1-weighted MR images showed a low-intensity mass with marked homogeneous enhancement in the area of bone destruction, and a dural tail adjacent to the tumor (flare sign) after Gd-DTPA administration. The tumor was totally resected, and was pathologically diagnosed as a calvarial metastasis of the cervical carcinoma. However, 5 months later the tumor recurred anterior to the site of the resection. Since the dura mater adjacent to the tumor exhibited collagen fiber proliferation, the dural tail sign was appeared to represent a reaction to the tumor. Other calvarial metastatic lesions appeared adjacent to the initial lesion 5 months after the initial lesion was resected, however, suggesting that tumor cell nests were present in the dura mater which exhibited the dural tail sign. Extensive pathological examination of the dura mater appears necessary whenever a dural tail sign is detected by magnetic resonance imaging.

Adult↗
PubMed1995

Comparison of iopamidol and ioversol in vitro and in animal studies.

In the present series of studies we investigated differences in vitro and in animal experiments between iopamidol (Iopamiron, CAS 60166-93-0) and ioversol (CAS 87771-40-2). The studies included the in vitro investigations partition coefficient, lysozyme inhibition, coagulation time and erythrocyte morphology as well as the in vivo paradigms acute toxicity, neural toxicity, general behavior/locomotor activity and angiography. Iopamidol was superior to ioversol in most of the tests. In spite of its higher hydrophilicity, ioversol did not show improved tolerance in comparison to iopamidol.

Angiography↗
PubMed1995

Accumulation of phosphatydilcholine-hydroperoxide in dialysis patients with diabetic nephropathy.

Plasma lipid peroxidation in noninsulin dependent diabetes mellitus (DM) patients were evaluated in DM patients undergoing hemodialysis (HD) by means of a chemiluminescence-HPLC for the specific determination of phosphatidylcholine hydroperoxide (PCOOH). Thirty-three uremic patients with DM nephropathy, undergoing 12 hours HD a week using polymethylmethacrylate membrane, were studied. Of them 22 DM patients on HD were divided into 2 age and sex matched groups treated and conventional group in order to clarify therapeutic effect of 500 mg alfa-tocopherol and 600 mg probucol daily. Fifty DM patients without end-stage renal disease (ESRD) who were age-, period of diabetes-, and sex-matched, were selected as positive control of the subjects. Plasma PCOOH levels were significantly elevated in both DM patients, while the plasma PCOOH in normal controls were 227.0 +/- 68.7 pmol/ml. Plasma PCOOH levels of DM patients undergoing HD were significantly higher than that of patients without ESRD (1,330.8 +/- 642.7 pmol/ml vs. 756.6 +/- 431.9 pmol/ml, p < 0.025). Partial correlation coefficient of plasma PCOOH level demonstrated PCOOH and period of HD in DM patients were highly significantly positively correlated (p < 0.01), although single session of HD was not found to produce significantly increased lipid-peroxidation. Plasma PCOOH roughly remained within similar levels as base lines by medication with anti-oxidant compared to that of conventional group. From these results we conclude that HD intensifies lipid peroxidation and such accumulation of hydroperoxide could account for accelerated progress of atherosclerosis in DM patients with renal insufficiency. It is worthwhile to try an administration of free radical scavenger in order to reduce PCOOH and slow down the progression of atherosclerotic vascular disease.

Adult↗
PubMed1994

Vesicle-bound conformation of melittin: transferred nuclear Overhauser enhancement analysis in the presence of perdeuterated phosphatidylcholine vesicles.

We determined a detailed conformation of the honeybee venom peptide melittin when bound to phosphatidylcholine vesicles using proton NMR. In the presence of vesicles of perdeuterated dipalmitoylglycerophosphocholine, two-dimensional transferred nuclear Overhauser enhancement (TRNOE) experiments were carried out. By a distance geometry calculation using NOE-derived distance constraints followed by a simulated annealing refinement, the N-terminal (Leu6-Leu10) and C-terminal (Leu13-Lys21) parts were found to have an alpha-helical conformation, whereas five C-terminal residues (Arg22-Gln26) did not show a unique conformation in the vesicle-bound state. The two alpha-helices were connected via a less structured segment (Thr11-Gly12) with a helix bend angle of 86 degrees +/- 34 degrees. Model distance geometry calculations using distance constraints extracted from a tetrameric melittin molecule in crystal assured us that the NOE constraints can accurately reproduce melittin's structure, as well as helping to interpret the NMR structures. Although the vesicle-bound conformation of melittin is similar to that occurring in a methanol solution and in dodecylphosphocholine micelles, significant differences were found in the conformation of C-terminal basic residues and the helix bend angle. This is the first study to clearly demonstrate conformation differences in micelle- and vesicle-bound peptides. In addition, lytic activity of melittin and its analogs showed better correlation with a peptide conformation in vesicles than in either methanol or micelles.

Amino Acid Sequence↗
PubMed1994

A gD homologous gene of feline herpesvirus type 1 encodes a hemagglutinin (gp60).

A gene-encoding glycoprotein D (gD) homologue of feline herpesvirus type 1 (FHV-1) was identified and sequenced. It was located within an EcoRI 4.3-kbp fragment in the middle of the unique short region. The primary translation product of the gD homologous gene is predicted to consist of 374 amino acids with a molecular weight (MW) of 43.2 kDa. Comparative analysis among gD counterparts of other herpesviruses revealed that six cysteine residues which correlate with disulfide bond structure were conserved, and the amino acid sequences had homologies of 32.6% with bovine herpesvirus type 1 gIV, 29.1% with pseudorabies virus gp50, 28.3% with equine herpesvirus type 1 gD, and 22.0% with herpes simplex virus type 1 gD. When the gD homologue was expressed in COS cells and examined by indirect immunofluorescence and immunoprecipitation assays, it was recognized only by monoclonal antibodies (MAbs) reactive with gp60 which have virus-neutralizing and hemagglutination (HA)-inhibition (HI) activities. This expressed product had a MW of approximately 60 kDa and was shown to be a hemagglutinin by HA and HI tests with the MAbs. These results suggest that the gD homologue of FHV-1 is a hemagglutinin.

Amino Acid Sequence↗