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M Tashiro

Publications and source records attributed to M Tashiro.

At least 55 records · Page 3Linked to original sources
PubMed2000

Purification, characterization, and relation to bikunin of rat urinary trypsin inhibitors.

Two forms of urinary trypsin inhibitor (UTI-1 and UTI-2) were purified from pooled urine of normal male rats to apparent homogeneity by salting out, affinity chromatography, gel filtration, and reverse-phase HPLC. UTIs-1 and 2 were shown to be thermostable glycoproteins with the respective molecular weights of 22,000 and 18,000 estimated by SDS-PAGE. These inhibitors combined with bovine trypsin in a 1:1 molar ratio: the Kd values were 2.5 x 10(-10) and 2.3 x 10(-10) M, respectively. Amino acid composition and sequence analysis indicated that UTI-1 corresponded to rat bikunin of which the amino acid sequence was deduced from a rat liver cDNA clone encoding alpha1-microglobulin [Lindqvist et al. (1992), Biochim. Biophys. Acta 1130, 63-67] except that the protein sequence seemed to lack C-terminal serine, and UTI-2 corresponded to UTI-1 lacking N-terminal 21 amino acid residues.

Amino Acid Sequence↗
PubMed2000

Comparative nucleotide sequence analyses of the entire genomes of B95a cell-isolated and vero cell-isolated measles viruses from the same patient.

Experimental infection of monkeys with the IC-B strain of measles virus (MV), which was isolated in marmoset B lymphoblastoid B95a cells from an acute measles patient, caused clinical signs typical for measles, while infection by the IC-V strain isolated in African green monkey kidney Vero cells from the same patient did not cause any clinical signs in infected monkeys. The IC-B strain replicated only in B95a cells, whereas the IC-V strain replicated in both B95a and Vero cells (3,6). To clarify which gene or mutation(s) was responsible for the difference in these phenotypes, the nucleotide sequences of the entire genomes of the IC-B and IC-V strains were determined. Comparative nucleotide sequence analyses revealed only two nucleotide differences, one in the P/V/C gene and the other in the M gene, predicting amino acid differences in the P, V and M proteins and a 19 amino acid deletion in the C protein of the IC-V strain. The truncation in the C protein was confirmed for the IC-V strain by immunoprecipitation using the C protein specific antiserum. No nucleotide difference was found in the envelope H gene. These results indicated that nucleotide difference(s) in the P/V/C or/and M gene, and not H gene, was responsible for the different cell tropism and pathogenicity of MV in this case.

Animals↗
PubMed2000

Total and prolonged filling of the lungs with Ringer's solution under extracorporeal lung assist (ECLA) in dogs.

BACKGROUND: Massive alveolar lavage has been used clinically to remove materials accumulated in the alveoli. Recently, filling the lungs with oxygenated perfluorochemical (total liquid ventilation) has been investigated. However, effects of complete and prolonged filling of bilateral lungs with aqueous fluid, such as saline or Ringer's solution, has not been evaluated, although it is possible to sustain gas exchange without the natural lung by using extracorporeal circulation and an artificial lung (extracorporeal lung assist: ECLA). It is also not known whether the lung can recover gas exchange ability after prolonged fluid filling. METHODS: Normal mongrel dogs were endotracheally intubated under general anesthesia and mechanically ventilated. After initiation of venoarterial ECLA, warmed lactated Ringer's solution was instilled into the lungs through the endotracheal tube, and the lungs were completely filled at a hydrostatic pressure of 15 cmH2O (fluid-filled group: group F). After the lungs were filled for 4 h, the fluid was drained and ventilation was re-instituted. ECLA, then mechanical ventilation was gradually weaned within 24 h after fluid drainage. In control group (group C), dogs were kept apneic for 4 h with their lungs inflated at an airway pressure of 15 cmH2O with air. RESULTS: Transient hypoxemia occurred during fluid filling but every dog could be weaned from ECLA and mechanical ventilation to spontaneous respiration. The average rate of fluid absorption from the lung during fluid filling was 4.2+/-1.8 ml kg(-1) h(-1). After fluid drainage and restart of mechanical ventilation, bilateral lungs were expanded and well aerated. Total static respiratory system compliance (static compliance) remained unchanged even after fluid filling, and the weight of the lung water did not increase significantly compared to that in group C. Total urine volume was significantly increased in group E Histologically, alveolar structures were preserved and no interstitial edema or bleeding was seen in either group. CONCLUSION: Complete filling of the bilateral lungs for 4 h with lactated Ringer's solution under ECLA causes no deterioration in gas exchange or static compliance in normal dogs, although transient hypoxemia occurs during fluid filling.

Animals↗
PubMed2000

Vaccines and therapeutics against influenza virus infections.

BACKGROUND: Vaccination prior to epidemic season is the best measure to control influenza virus infection; however, there are several issues to be considered regarding influenza vaccines in Japan. In the present review, current issues regarding influenza vaccine in Japan are described, as well as the future prospects of vaccine development. As well as vaccination, anti-influenza agents such as amantadine are now available in Japan. Furthermore, neuraminidase inhibitors are expected to appear in the market in near future. These anti-influenza agents represent new options for influenza control. CONCLUSIONS: Vaccination and antiviral agents are a major armamentarium against influenza infections. Thus, exploratory studies on novel forms of vaccine and anti-influenza drugs should help to prepare against pandemics that must emerge in near future.

Amantadine↗
PubMed2000

Influenza virus-induced encephalopathy: clinicopathologic study of an autopsied case.

BACKGROUND: Rapid progressive encephalopathy with a high fever, consciousness loss and recurrent convulsions has been occasionally reported in children during influenza pandemics in Japan since 1995. We examined a 2-year old girl with hemorrhagic shock and encephalopathy syndrome associated with acute influenza A virus infection (A/Nagasaki/76/98; H3N2), to answer several questions for which no histologic or virologic data exist. METHODS: A clinicopathologic study using immunohistochemical staining and viral genome detection by reverse transcriptase polymerase chain reaction (RT-PCR) was performed with this autopsied case. RESULTS: The virus antigen was positive in CD8+ T lymphocytes from the lung and spleen. The virus infected a very limited part of the brain, especially Purkinje cells in the cerebellum and many neurons in the pons, without inducing an overt immunologic reaction from the host. The RT-PCR used for detecting the hemagglutinin gene demonstrated positive bands in all frozen tissues and cerebrospinal fluid taken at autopsy and not in samples obtained on admission. CONCLUSIONS: The pathologic change induced by the direct viral invasion cannot be responsible for all of the symptoms, especially for the rapid and severe clinical course of the disease within 24-48 h after the initial respiratory symptoms. Together with the rapid production of several inflammatory cytokines, the breakdown of the blood-brain barrier may induce severe brain edema and can be a major pathologic change for the disease. Any therapeutic strategy to control this multistep progression of the disease could be effective.

Antigens, Viral↗
PubMed2000

Regulation of the initiation of pancreatic digestive enzyme protein synthesis by cholecystokinin in rat pancreas in vivo.

BACKGROUND & AIMS: Cholecystokinin (CCK) is known to stimulate the synthesis of digestive enzymes in the pancreas at the translational level. We investigated in vivo the biochemical regulation of initiation factors important for the stimulation of translation of digestive enzyme protein in rat pancreas by CCK. METHODS: Intraperitoneal injection of CCK or intragastric administration of a trypsin inhibitor to elicit endogenous CCK release was followed by removal and preparation of pancreas for protein evaluation. Isoelectric focusing was used to evaluate the phosphorylation of the initiation factor eIF4E, and Western blotting and immunoprecipitation followed by Western blotting were used to study the phosphorylation state and amount of other interacting factors. RESULTS: CCK treatment induced a time- and dose-dependent phosphorylation of pancreatic eIF4E and its binding protein (PHAS-I). Because the release of eIF4E from its binding protein as a result of phosphorylation is followed by formation of a messenger RNA cap-binding complex that includes the initiation factor eIF4G, we evaluated the association of eIF4G with released eIF4E and showed that it was increased by CCK. These events occurred over a range of CCK doses from 0.2 to 5 microg/kg. We also evaluated the effect of endogenous CCK by administering a synthetic trypsin inhibitor, camostat (100 mg/kg). Camostat treatment markedly increased the phosphorylation of both PHAS-I and eIF4E and the formation of eIF4E-eIF4G complex. Thus, both exogenous and endogenous CCK activate translational initiation factors in vivo. CONCLUSIONS: Activation of translational machinery necessary for initiation of protein synthesis likely contributes to the normal postprandial synthesis of pancreatic digestive enzymes.

Animals↗
PubMed2000

Whole-body energy mapping under physical exercise using positron emission tomography.

We attempted to visualize dynamic adjustment of glucose utilization in humans in the whole-body organs during physical exercise by using three-dimensional positron emission tomography (3D-PET) and [18F]-2-fluoro-deoxy-glucose (FDG). Twelve healthy male volunteers collaborated on the study; six subjects were assigned to the resting control group (C) and the other six to the running group (E). Group E subjects performed running on a flat road for 35 min. After 15 min of running, subjects injected FDG and kept on running thereafter for another 20 min. Group C subjects sat on a comfortable chair in a quiet room for 35 min after the injection of FDG. After scanning by PET, the regions of interest (ROIs) were manually set on brain, heart, thorax, abdomen, lower extremities, and the rest of the body on the corresponding transaxial images. The uptake of FDG in each region was evaluated as the % fraction of FDG accumulation relative to the total amount of whole-body accumulation. The results revealed increase of FDG uptake after running in the lower leg muscles from 24.6 +/- 9.5% to 43.1 +/- 4.7% and in the heart from 2.3 +/- 0.4% to 2.8 +/- 0.6%. The differences were significant (P < 0.05). These increases reflect the rise in energy consumption in leg and heart muscles and were balanced by the reduction of energy consumption in the other part of the body. FDG uptake in the abdominal region reduced from 37.3 +/- 7.2% to 19.7 +/- 4.9%. However, FDG uptake in the brain remained stable, i.e., 11.9 +/- 2.8% at rest and 10.3 +/- 2.5% after exercise. Thus, 3D-PET is a tool to visualize the dynamic adjustment of energy consumption during physical exercise in humans.

Adult↗
PubMed2000

Versatility of the accessory C proteins of Sendai virus: contribution to virus assembly as an additional role.

The P/C mRNA of Sendai virus (SeV) encodes a nested set of accessory proteins, C', C, Y1, and Y2, referred to collectively as C proteins, using the +1 frame relative to the open reading frame of phospho (P) protein and initiation codons at different positions. The C proteins appear to be basically nonstructural proteins as they are found abundantly in infected cells but greatly underrepresented in the virions. We previously created a 4C(-) SeV, which expresses none of the four C proteins, and concluded that the C proteins are categorically nonessential gene products but greatly contribute to viral full replication and infectivity (A. Kurotani et al., Genes Cells 3:111-124, 1998). Here, we further characterized the 4C(-) virus multiplication in cultured cells. The viral protein and mRNA synthesis was enhanced with the mutant virus relative to the parental wild-type (WT) SeV. However, the viral yields were greatly reduced. In addition, the 4C(-) virions appeared to be highly anomalous in size, shape, and sedimentation profile in a sucrose gradient and exhibited the ratios of infectivity to hemagglutination units significantly lower than those of the WT. In the WT infected cells, C proteins appeared to colocalize almost perfectly with the matrix (M) proteins, pretty well with an external envelope glycoprotein (hemagglutinin-neuraminidase [HN]), and very poorly with the internal P protein. In the absence of C proteins, there was a significant delay of the incorporation of M protein and both of the envelope proteins, HN and fusion (F) proteins, into progeny virions. These results strongly suggest that the accessory and basically nonstructural C proteins are critically required in the SeV assembly process. This role of C proteins was further found to be independent of their recently discovered function to counteract the antiviral action of interferon-alpha/beta. SeV C proteins thus appear to be quite versatile.

Animals↗
PubMed2000

Recovery of pathogenic measles virus from cloned cDNA.

Reverse genetics technology so far established for measles virus (MeV) is based on the Edmonston strain, which was isolated several decades ago, has been passaged in nonlymphoid cell lines, and is no longer pathogenic in monkey models. On the other hand, MeVs isolated and passaged in the Epstein-Barr virus-transformed marmoset B-lymphoblastoid cell line B95a would retain their original pathogenicity (F. Kobune et al., J. Virol. 64:700-705, 1990). Here we have developed MeV reverse genetics systems based on the highly pathogenic IC-B strain isolated in B95a cells. Infectious viruses were successfully recovered from the cloned cDNA of IC-B strain by two different approaches. One was simple cotransfection of B95a cells, with three plasmids each encoding the nucleocapsid (N), phospho (P), or large (L) protein, respectively, and their expression was driven by the bacteriophage T7 RNA polymerase supplied by coinfecting recombinant vaccinia virus vTF7-3. The second approach was transfection with the L-encoding plasmid of a helper cell line constitutively expressing the MeV N and P proteins and the T7 polymerase (F. Radecke et al., EMBO J. 14:5773-5784, 1995) on which B95a cells were overlaid. Virus clones recovered by both methods possessed RNA genomes identical to that of the parental IC-B strain and were indistinguishable from the IC-B strain with respect to growth phenotypes in vitro and the clinical course and histopathology of experimentally infected cynomolgus monkeys. Thus, the systems developed here could be useful for studying viral gene functions in the context of the natural course of MeV pathogenesis.

Animals↗
PubMed2000

Sodium gradient-dependent transport of magnesium in rat ventricular myocytes.

Cytoplasmic concentration of Mg(2+) ([Mg(2+)](i)) was measured with a fluorescent indicator furaptra in ventricular myocytes enzymatically dissociated from rat hearts (25 degrees C). To study Mg(2+) transport across the cell membrane, cells were treated with ionomycin in Ca(2+)-free (0.1 mM EGTA) and high-Mg(2+) (10 mM) conditions to facilitate passive Mg(2+) influx. Rate of rise of [Mg(2+)](i) due to the net Mg(2+) influx was significantly smaller in the presence of 130 mM extracellular Na(+) than in its absence. We also tested the extracellular Na(+) dependence of the net Mg(2+) efflux from cells loaded with Mg(2+). After [Mg(2+)](i) was raised by ionomycin and high Mg(2+) to the level 0.5-0.6 mM above the basal value ( approximately 0.7 mM), washout of ionomycin and lowering extracellular [Mg(2+)] to 1.2 mM caused rapid decline of [Mg(2+)](i) in the presence of 140 mM Na(+). This net efflux of Mg(2+) was completely inhibited by withdrawal of extracellular Na(+) and was largely attenuated by imipramine, a known inhibitor of Na(+)/Mg(2+) exchange, with 50% inhibition at 79 microM. The relation between the rate of net Mg(2+) efflux and extracellular Na(+) concentration ([Na(+)](o)) had a Hill coefficient of 2 and [Na(+)](o) at half-maximal rate of 82 mM. These results demonstrate the presence of Na(+) gradient-dependent Mg(2+) transport, which is consistent with Na(+)/Mg(2+) exchange, in cardiac myocytes.

Adrenergic Uptake Inhibitors↗
PubMed2000

[An electrosurgical burn possibly caused by radio-frequency leakage current through a stainless forceps].

A 73-year-old operated female got burned on the skin probably nipped by a stainless forceps. An active cable had been coiled around the forceps throughout the surgery. Consequently, an electrosurgical burn was possibly caused by radio-frequency leakage current (RFLC) via the metallic forceps. The authors experimentally coiled active cables around a stainless forceps, then measured RFLC produced by four kinds of electrosurgical units in the modes of cutting, blend, coagulation, spray coagulation, and argon beam coagulation. The maximum of RFLC was 81 mA, which met the JIS or IEC standard (150 mA). However, the critical current density causing electrosurgical burns (> 25-70 mA.cm-2) was suggested to be produced by RFLC through a metallic forceps with a small diameter. Of great importance is not to coil active cables around electro-conductible instruments during surgery.

Aged↗
PubMed1999

Cerebrospinal fluid levels of amyloid beta-peptide1-42, but not tau have positive correlation with brain glucose metabolism in humans.

To address the question of whether assay for cerebrospinal fluid (CSF) levels of amyloid beta-peptide 1-42 (A(beta)1-42) and tau allow us to monitor the neurodegenerative processes that lead to a progressive and massive death of neurons in Alzheimer's disease (AD) and non-AD patients, cerebral glucose metabolism using 2-[18F] fluoro-2-deoxy-glucose was quantified by positron emission tomography in fifteen AD patients and nine non-AD patients with defined levels of CSF-A(beta)1-42 and CSF-tau. The CSF-A(beta)1-42 levels, but not the CSF-tau levels, in both AD and non-AD patients consistently and significantly correlated with global and, in particular, temporal lobe glucose metabolism. Results from our study suggest that the CSF-A(beta)1-42 levels may reflect residual brain function and help monitoring progression of dementing disorders.

Aged↗
PubMed1999

Determinants of organ tropism of sendai virus.

Wild-type Sendai virus is exclusively pneumotropic in mice. Protease activation mutants, ts-f1 and F1-R, were isolated from persistently infected tissue culture cells. Additional mutants were isolated from wild-type Sendai virus with phenotypes similar to the pantropic mutant, F1-R. The genome of the mutants was sequenced and mutations were revealed in several proteins encoded by the genes. Three of the six mutations in the fusion (F) proteins were considered prime candidates for the determinant of pantropism. Characterization of the mutants led to the finding that the exchange (Ser to Pro) residue 115 next to the cleavage site of the F protein was the primary determinant that resulted in the enhanced cleavability of the F protein. Another important finding was bipolar budding of F1-R in polarized epithelial cells and mouse bronchial epithelium. This has been attributed to two mutations in the matrix (M) protein, at residues 128 (Asp to Gly) and 210 (Ile to Thr). Thus the determinants of pantropism of F1-R are protease activation of the F protein and bipolar budding attributed to the mutated M protein and enhanced disruption of microtubules.

Amino Acid Substitution↗
PubMed1999

Pharmacologic profile of TS-941, a new benzodiazepine derivative cholecystokinin-receptor antagonist, in in vitro isolated rat pancreatic acini.

We investigated the pharmacologic characteristics of a newly developed benzodiazepine derivative (S)-(-)-N-[2,3-dihydro-2-oxo-5-phenyl-1-[(1H-tetrazol-5-yl)methyl] -1H-1,4-benzodiazepine-3-yl]-2-indolecarboxamide (TS-941), a cholecystokinin type A (CCK-A)-receptor antagonist, in the isolated rat pancreatic acini and compared with those of well-known CCK-A-receptor antagonists, devazepide and loxiglumide. TS-941 inhibited CCK-8-stimulated amylase release concentration dependently, as did devazepide and loxiglumide, with a half-maximal inhibition (IC50) at 78.6 +/- 10.3 nM. TS-941 was approximately 23 times less potent than devazepide (IC50, 3.4 +/- 0.3 nM), but was 50 times more potent than loxiglumide (IC50, 3,966 +/- 544 nM) in inhibiting 100 pM CCK-8-stimulated amylase release from rat pancreatic acini. TS-941 had a fivefold lower selectivity than devazepide for pancreatic CCK (CCK-A) over brain CCK (CCK-B) receptors but fourfold greater than loxiglumide when IC50 values for inhibition of [125I]CCK-8 binding in isolated acini and cerebral cortex were compared. The antagonism produced by TS-941 was specific for CCK in that the effects of other receptor secretagogues or agents bypassing receptors were not altered. TS-941 caused a parallel rightward shift of the entire dose-response curve for CCK-8-stimulated amylase release without altering the maximal increase, as did devazepide and loxiglumide. TS-941, whether added at the beginning or 20 min after the CCK-8 stimulation, inhibited amylase release. TS-941 caused a concentration-dependent residual inhibition of the action of CCK-8. The acini, once incubated with a high concentration of TS-941 (10 microM; 127 times IC50) for 30 min, was 10-fold less sensitive to CCK-8 than the acini preincubated without TS-941, whereas the sensitivity and the responsiveness to CCK-8 stimulation of those incubated with a low concentration of TS-941 (1.0 microM) were similar to the control acini. These results indicate that TS-941 is a potent, competitive, and selective CCK-A receptor antagonist for the pancreas.

Amylases↗
PubMed1999

Avirulent Avian influenza virus as a vaccine strain against a potential human pandemic.

In the influenza H5N1 virus incident in Hong Kong in 1997, viruses that are closely related to H5N1 viruses initially isolated in a severe outbreak of avian influenza in chickens were isolated from humans, signaling the possibility of an incipient pandemic. However, it was not possible to prepare a vaccine against the virus in the conventional embryonated egg system because of the lethality of the virus for chicken embryos and the high level of biosafety therefore required for vaccine production. Alternative approaches, including an avirulent H5N4 virus isolated from a migratory duck as a surrogate virus, H5N1 virus as a reassortant with avian virus H3N1 and an avirulent recombinant H5N1 virus generated by reverse genetics, have been explored. All vaccines were formalin inactivated. Intraperitoneal immunization of mice with each of vaccines elicited the production of hemagglutination-inhibiting and virus-neutralizing antibodies, while intranasal vaccination without adjuvant induced both mucosal and systemic antibody responses that protected the mice from lethal H5N1 virus challenge. Surveillance of birds and animals, particularly aquatic birds, for viruses to provide vaccine strains, especially surrogate viruses, for a future pandemic is stressed.

Animals↗
PubMed1999

Cerebrospinal fluid tau protein levels in demented and nondemented alcoholics.

The tau protein levels in cerebrospinal fluid (CSF-tau) were examined in 27 patients with alcohol dependence (20 demented and 7 nondemented), 36 age and dementia severity-matched patients with Alzheimer's disease (AD), and 23 age-matched normal control subjects. The CSF-tau levels in the demented alcoholic group (alcohol-induced organic brain disorders, 25.4 +/- 10.2 pg/ml) was significantly lower (p < 0.0001) than that in the AD group (96.1 +/- 53.3 pg/ml), but not significantly different from that in the nondemented alcoholics (18.1 +/- 10.2 pg/ml) or the controls (19.2 +/- 12.9 pg/ml). Using a 44.9 pg/ml as a cut-off value (mean + 2 SD of the normal control group), only one patient with alcohol-induced organic brain disorders exceeded the value, whereas 3 of 36 of the AD group showed CSF-tau levels less than this level. These findings suggest that alcohol-induced organic brain disorders are a group of dementias that are characterized by normal CSF-tau levels, and that the CSF examination for tau in combination with other clinical findings may help in differentiating alcohol-induced organic brain disorders from AD.

Adolescent↗
PubMed1999

[A report on clinical PET activities in Germany].

Clinical diagnostic procedure using positron emission tomography (PET) requires high costs. To promote clinical use of PET, sociomedical evaluation is necessary. In this paper, sociomedical situations concerning clinical use of PET in Germany is reported. Some comparisons are made between Japan and this country putting emphases on several points such as 1) number of cyclotron and PET facilities, 2) social restriction to transportation of radioisotopes, 3) activities of satellite PET facilities, and 4) clinical indications for PET studies. Number of cyclotron was larger in Japan (29) than in Germany (17), but number of PET facilities was larger in Germany (47) than in Japan (29). The reason seems that in Germany transportation and buying of radioisotopes is less restricted. Hence, more than half of PET facilities in Germany are "satellite facilities" which do not have their own cyclotrons. Radioisotope distribution seems to serve as a backbone of "satellite concept." Additionally in Germany, list of clinical indications for PET study is almost completed and now is widely in applied to most cases. To promote clinical use of PET in Japan, the German system might serve as an important socioeconomic model in Europe instead of the United States.

Cyclotrons↗