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S Terada

Publications and source records attributed to S Terada.

At least 37 records · Page 2Linked to original sources
PubMed2001

Caspase activation in high-pressure--induced apoptosis of murine erythroleukemia cells.

Murine erythroleukemia cells were subjected to physicochemical stresses such as high pressure (60--110 MPa), heating (42--45 degrees C), and ultraviolet (UV) irradiation (5--25 kJ/cm(2)). After exposure to these stresses, the cells were cultured at 37 degrees C and atmospheric pressure. The number of the cells treated at 100 MPa, 45 degrees C, or 20 kJ/cm(2) remained constant or decreased at an early stage of culture. The nuclear morphology, agarose gel electrophoresis, and flow cytometry of these cells showed that they undergo apoptosis. The activity of caspase-3 was observed in cells subjected to each stress. In particular, caspase-3 was most readily activated by high pressure under our conditions. The caspase-3 activity and apoptosis exhibited a similar pressure dependence. It is important that both caspase-3 activation and apoptosis induced by high pressure were significantly suppressed by a caspase-3 inhibitor. These results suggest that high-pressure-induced apoptosis is also characterized by the activation of caspase-3, as seen with heat- and UV-induced apoptosis.

Animals↗
PubMed2001

[Successful treatment of hairy cell leukemia with pentostatin].

A 45-year-old woman was admitted to our hospital in August, 1999. Laboratory data showed a white blood cell count of 5,050/microliter with 78% abnormal lymphocytes, hemoglobin 6.8 g/dl, platelets 4.8 x 10(4)/microliter, and soluble IL-2 receptor 97,600/ml. The abnormal cells were characterized by a hairy appearance under phase contrast microscopy, and showed strong tartrate-resistant acid phosphatase activity. Immunophenotype analysis revealed that these cells were positive for CD11c, CD19 and CD25, and negative for CD5. Bone marrow biopsy showed diffuse proliferation of hairy cells with moderate myelofibrosis. We diagnosed the patient as having European-American-type hairy cell leukemia. Pentostatin was administered at a dose of 5 mg/m2 weekly. After twelve doses, the peripheral blood data returned to the normal range with no hairy cells in the blood or bone marrow, although slight splenomegaly remained. The patient underwent splenectomy in December of the same year, and we were unable to find any hairy cells by histological and immunohistochemical examination. Although most patients with hairy cell leukemia in Japan have the Japanese variant, and the European-American type is rare, pentostatin is as effective as it is for European and American patients.

Female↗
PubMed2000

Oligomeric tubulin in large transporting complex is transported via kinesin in squid giant axons.

Slow axonal transport depends on an active mechanism that conveys cytosolic proteins. To investigate its molecular mechanism, we now constructed an in vitro experimental system for observation of tubulin transport, using squid giant axons. After injecting fluorescence-labeled tubulin into the axons, we monitored the movement of fluorescence by confocal laser scanning microscopy and fluorescence correlation spectroscopy. Here, from the pharmacological experiments and the functional blocking of kinesin motor protein by anti-kinesin antibody, we show that the directional movement of fluorescent profile was dependent on kinesin motor function. The fluorescent correlation function and estimated translational diffusion time revealed that tubulin molecule was transported in a unique form of large transporting complex distinct from those of stable polymers or other cytosolic protein.

Actomyosin↗
PubMed2000

KIF5C, a novel neuronal kinesin enriched in motor neurons.

Kinesin superfamily proteins (KIFs) are the molecular motors conveying cargos along microtubules. KIF5s, the heavy chains of conventional kinesin (KHC), are originally identified members of KIFs, and neuronal KIF5A and ubiquitous KIF5B have been identified so far. In the present work, we cloned a novel member of KIF5, KIF5C, and generated specific antibodies against three KIF5s to investigate their distribution and functions. KIF5A showed pan-neuronal distribution in the nervous system. KIF5B showed a glial cell distribution pattern in general; however, interestingly, its expression was strongly upregulated in axon-elongating neurons, such as olfactory primary neurons and mossy fibers. KIF5C was also a neuronal KIF5 like KIF5A but was highly expressed in lower motor neurons in 2-week-old or older mice, suggesting its important roles in the maintenance of motor neurons rather than in their formation, such as axonal elongation. Because a large part of KIF5s in adult motor neurons were expected to be KIF5C, we generated mice lacking the kif5C gene to investigate the functions of KIF5C in neurons in living animals. The mutant mice showed smaller brain size but were viable and did not show gross changes in the nervous system. Closer examinations revealed the relative loss of motor neurons to sensory neurons. Because three KIF5s showed high similarity in the amino acid sequence, could rescue the KIF5B mutant cells, and could form heterodimers, we think that there are functional redundancy among the three KIF5s and that KIF5A and KIF5B prevented the KIF5C null mice from the severe phenotype.

Amino Acid Sequence↗
PubMed2000

Tau pathology in diffuse neurofibrillary tangles with calcification (DNTC): biochemical and immunohistochemical investigation.

Diffuse neurofibrillary tangles with calcification (DNTC) represents a primary and sporadic presenile dementia that is characterized by temporal or fronto-temporal atrophy with diffuse neurofibrillary tangles (NFTs), neuropil threads and Fahr-type calcification without senile plaques. We examined the tau pathology in five autopsy cases of DNTC by immunoblotting and immunohistochemistry using phosphorylation-dependent and -independent anti-tau antibodies. The pattern of staining for different epitopes of beta-amyloid (A beta) was also investigated. NFTs were immunopositive with all the anti-tau antibodies used in this study. On the immunoblots, sarkosyl-insoluble tau appeared as three major bands of 60, 64 and 68 kDa, and as a minor band at 72 kDa. The majority of extracellular NFTs were weakly immunopositive only with the antibody recognizing the 40 carboxyl-terminal of A beta in DNTC. These results suggest that Alzheimer's disease-like tau pathology could exist independently of A beta deposits in DNTC.

Aged↗
PubMed2000

cDNA Cloning and mRNA analysis of PGC-1 in epitrochlearis muscle in swimming-exercised rats.

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), a cold-inducible coactivator of nuclear receptors, stimulates mitochondrial biogenesis and respiration in muscle cells. In the present study, we first cloned a rat PGC-1 gene from a brown adipose tissue cDNA library which encodes a predicted 796-amino-acid protein and exhibits respectively 98% and 95% identity with the mouse and human homologues. Next, we examined the effect of swimming exercise training on the level of expression of the PGC-1 gene in rat epitrochlearis (Epi) muscle. PGC-1 mRNA level in Epi muscle in rats that swam 2 h a day for 3 and 7 days increased dramatically by 154% and 163%, respectively, compared to the non-exercised control group. PGC-1 mRNA up-regulation was not observed in an immersion group treated at 35 degrees C during the training program but without swimming exercise. These results demonstrate that expression of the PGC-1 gene in Epi muscle is induced not only by cold exposure but also by prolonged low-intensity physical exercise.

Animals↗
PubMed2000

Kinesin superfamily protein 3 (KIF3) motor transports fodrin-associating vesicles important for neurite building.

Kinesin superfamily proteins (KIFs) comprise several dozen molecular motor proteins. The KIF3 heterotrimer complex is one of the most abundantly and ubiquitously expressed KIFs in mammalian cells. To unveil the functions of KIF3, microinjection of function-blocking monovalent antibodies against KIF3 into cultured superior cervical ganglion (SCG) neurons was carried out. They significantly blocked fast axonal transport and brought about inhibition of neurite extension. A yeast two-hybrid binding assay revealed the association of fodrin with the KIF3 motor through KAP3. This was further confirmed by using vesicles collected from large bundles of axons (cauda equina), from which membranous vesicles could be prepared in pure preparations. Both immunoprecipitation and immunoelectron microscopy indicated the colocalization of fodrin and KIF3 on the same vesicles, the results reinforcing the evidence that the cargo of the KIF3 motor consists of fodrin-associating vesicles. In addition, pulse-labeling study implied partial comigration of both molecules as fast flow components. Taken together, the KIF3 motor is engaged in fast axonal transport that conveys membranous components important for neurite extension.

Animals↗
PubMed2000

Tau-negative astrocytic star-like inclusions and coiled bodies in dementia with Lewy bodies.

To evaluate glial lesions in cases of dementia with Lewy bodies (DLB), we studied the brains of four patients with DLB. Astrocytic star-like inclusions, which resembled tufted astrocytic fibrillary tangles in shape, were found in the cortex of two of these cases. In addition, coiled bodies were found in the white matter of the cerebrum in two cases. The astrocytic star-like inclusions were immunohistochemically negative for tau protein, ubiquitin and alpha-synuclein. The coiled bodies were immunohistochemically negative for tau protein but immunopositive for ubiquitin and alpha-synuclein. These results suggest that in DLB a primary degenerative process takes place in both glial cells and neurons.

Aged↗
PubMed2000

Moving on to the cargo problem of microtubule-dependent motors in neurons.

Vigorous investigation has finally begun to shed light on the cargo problem of the microtubule-dependent motors, kinesin and dynein superfamily proteins. Biochemical observations have suggested that the potential cargoes of certain populations of motor proteins seem to be in vesicle-form, each vesicle possessing specific functional marker molecules. In addition to the close relationship between microtubule-dependent motors and cargoes in vesicle-form, kinesin has also been highlighted as an apparent driving force for another cargo in non-vesicle-form, cytoplasmic protein. On the basis of new biophysical and cell-biological evidence, the controversy over the movement of cytoplasmic cargoes has entered a new phase.

Animals↗
PubMed2000

An autopsy case of postencephalitic parkinsonism of von Economo type: some new observations concerning neurofibrillary tangles and astrocytic tangles.

An autopsied case of postencephalitic parkinsonism of von Economo type with a 71-year duration is reported. Several cases of postencephalitic parkinsonism of von Economo type have been reported in Japan but this is the first reported case from western Japan. The patient was a Japanese man who was 74 years of age at the time of death. He developed encephalitis of unknown etiology at the age of 3 years. The first symptom was antisocial behavior, which developed at 30 years of age. At the age of 40 years, the patient showed progressive parkinsonism. Neuropathological findings disclosed marked neuronal loss with gliosis in the substantia nigra, locus ceruleus, and raphe nuclei, as well as the appearance of neurofibrillary tangles in the aforementioned areas. There were also widespread tuft-shaped astrocytes (Tu-SA) in the central nervous system, including the thalamus. Tuft-shaped astrocytes are considered to represent non-reactive astrocytes because the distributions of neurofibrillary tangles (NFT) and Tu-SA are clearly different. Therefore, the primary astrocytic lesions in postencephalitic parkinsonism of von Economo type may be more widespread. Ultrastructurally, the Tu-SA consisted of straight filaments, 15 nm in width, which formed tight bundles. Ultrastructurally, NFF in this case revealed paired helical filaments but straight filaments, 15 nm in width, which were also found in the neurons of the substantia nigra.

Aged↗
PubMed2000

Primary structure and autoproteolysis of brevilysin H6 from the venom of Gloydius halys brevicaudus.

The complete amino acid sequence of brevilysin H6 (H6), a zinc-protease isolated from Gloydius halys brevicaudus venom, was determined by a manual Edman degradation method. H6 has an amino-terminal pyroglutamic acid and consists of a total of 419 residues. An N-linked sugar chain is attached at Asn-181. The molecule is composed of three domains (metalloprotease, disintegrin-like and cysteine-rich domains), as commonly found in other high molecular mass metalloproteases from snake venoms. In the absence of calcium ions, H6 is autocatalytically degraded with a half-life of 47 min to give 29 and 45 kDa fragments, which correspond to residues 208-419 and 99-419 of H6, respectively. Thus, the autoproteolysis seemed to start from the cleavage of either the Leu(98)-Leu(99) or Asp(207)-Ile(208) bond. Calcium ions suppressed both the formation of the 45 kDa fragment and the rate of autoproteolysis. Calcium ions also contributed to the stability of H6 against pH, heating, urea and cysteine. More than twenty-five peptide bonds adjacent to hydrophobic residues in the metalloprotease domain were progressively cleaved during the autoproteolysis.

Amino Acid Sequence↗
PubMed2000

[Aspergillosis with non-cavitary lung cancer].

Growth of Aspergillus was observed in the necrotic tissue of non-cavitary lung cancer. Case 1 was a 60-year-old male complaining of cough and fever and was found to have left lower lobe atelectasis on chest X-ray. Bronchoscopic examination showed the yellow soft lesion occluding the left upper and lower lobe bronchus. Specimen from the lesion demonstrated adenocarcinoma and hyphae of Aspergillus in the necrotic tumor. Case 2 was a 53-year-old male who was found to have a left upper lobe mass by chest X-ray screening. Bronchoscopic examination showed the yellow polypoid lesion occluding the left upper division bronchus. Pneumonectomy was done and resected specimen of the lesion demonstrated adenocarcinoma and the hyphae of Aspergillus growing in both necrotic tissue and cancer tissue. As both patients had hyphae of Aspergillus in the necrotic tumor, it is considered that the presence of necrosis may cause the growth of Aspergillus.

Adenocarcinoma↗
PubMed2000

Purification and characterization of a basic amino acid-specific peptidase from seeds of jack bean (Canavalia ensiformis).

A peptidase was purified from seeds of Canavalia ensiformis by extraction with water, ammonium sulfate precipitation, and successive chromatographies on DEAE-Toyopearl 650M, butyl-Toyopearl 650M, and G-3000 SW columns. The enzyme has an apparent molecular weight of 41,000. Activity is maximal at pH 9 and 60 degrees C. The enzyme hydrolyzed synthetic substrates at Arg-X and Lys-X bonds more rapidly than bovine trypsin did, and did not cleave protein or ester substrates. The enzyme was inhibited by alkylamines and several serine protease inhibitors such as diisopropylfluorophosphate, chymostatin, leupeptin, and benzamidine. Cysteine protease-, metalloprotease-, and proteinous trypsin inhibitors were ineffective. Inhibition by alkylamines was dependent on length of the alkyl chains. From the substrate specificity and susceptibility to chemicals, the enzyme is a unique peptidase with trypsin-like specificity.

Chromatography, Ion Exchange↗
PubMed2000

High pressure sensitizes murine erythroleukemia cells to caffeine-induced premature mitosis.

Murine erythroleukemia (MEL) cells were exposed to a high pressure of 80 MPa or aphidicolin (APH), DNA polymerase inhibitor. The effects of caffeine on cell cycle were examined using these cells. During the culture of 80 MPa-treated MEL cells at atmospheric pressure, the cells arrested in the G2 phase, and cyclin B and hyperphosphorylated p34(cdc2) were accumulated. Namely, maturation promoting factor (MPF) composed of p34(cdc2) and cyclin B was inactive. However, upon exposure to caffeine, these cells entered prematurely into mitosis by activating MPF. Caffeine-induced premature mitosis was suppressed by butyrolactone I and orthovanadate. On the other hand, APH-treated MEL cells, which were not exposed to 80 MPa, were not so sensitive to caffeine-induced premature mitosis despite cyclin B accumulation. In this case, dephosphorylation of p34(cdc2) was not induced by caffeine. Interestingly, caffeine-induced premature mitosis in the 80 MPa-treated cells was also suppressed by APH. These results suggest that the premature mitosis of 80 MPa-treated MEL cells by caffeine is induced by active MPF, and that APH-sensitive molecules such as DNA polymerase may also play an important role in the checkpoint that controls the transition from G2 to M phase.

Animals↗
PubMed2000

Tissue engineering in the twenty-first century.

In the 20th century, free tissue transfers have been successfully introduced using microvascular anastomosis techniques. Transplants not only include whole organs such as the kidney, liver and lung, but also bone, muscle and skin. However, there are a limited number of organs available for transplantation. This leads to the patient not only suffering from the malfunctioning tissue or organ, but also from the psychological trauma of an indefinite waiting period. The rapidly evolving field of tissue engineering is beginning to have an impact on free tissue transfers including organ. Small biopsy specimens can be grown into a large number of cells. These cultured cells can then be seeded onto biodegradable polymers, which serve several purposes. Firstly, the polymers function as a cell delivery system that enables the transplantation of a large numbers of cells into an organism. Secondly, they create a three-dimensional space for cell growth and serve as a template, thereby providing a structure for the extracellular matrix. These approaches have been demonstrated as practical strategies for the reconstruction of many tissues such as the liver, intestines, heart valve leaflets, bone and cartilage.

Animals↗
PubMed1999

Impairment of inhibitory synaptic transmission in mice lacking synapsin I.

Deletion of the synapsin I genes, encoding one of the major groups of proteins on synaptic vesicles, in mice causes late onset epileptic seizures and enhanced experimental temporal lobe epilepsy. However, mice lacking synapsin I maintain normal excitatory synaptic transmission and modulation but for an enhancement of paired-pulse facilitation. To elucidate the cellular basis for epilepsy in mutants, we examined whether the inhibitory synapses in the hippocampus from mutant mice are intact by electrophysiological and morphological means. In the cultured hippocampal synapses from mutant mice, repeated application of a hypertonic solution significantly suppressed the subsequent transmitter release, associated with an accelerated vesicle replenishing time at the inhibitory synapses, compared with the excitatory synapses. In the mutants, morphologically identifiable synaptic vesicles failed to accumulate after application of a hypertonic solution at the inhibitory preterminals but not at the excitatory preterminals. In the CA3 pyramidal cells in hippocampal slices from mutant mice, inhibitory postsynaptic currents evoked by direct electrical stimulation of the interneuron in the striatum oriens were characterized by reduced quantal content compared with those in wild type. We conclude that synapsin I contributes to the anchoring of synaptic vesicles, thereby minimizing transmitter depletion at the inhibitory synapses. This may explain, at least in part, the epileptic seizures occurring in the synapsin I mutant mice.

Animals↗
PubMed1999

Experimental study of ectopic-free tissue transfer of rabbit epigastric flap using small-caliber vascular grafts.

Ectopic intraperitoneal free-tissue grafting using small-caliber artificial vascular grafts is reported. The vascular grafts were polyurethane tubes (inner diameter 1.4 mm; outer diameter 1.9 mm; length 15 mm) with a coating of the antithrombotic agents argatroban and 2-hydroxyethylmethacrylate-styrene block copolymer (HS)on the inner surface. The patency of the artificial vessels was investigated in an ectopic-free rabbit epigastric flap in which grafts were used for anastomosis between the femoral and renal vessels. The mean patent duration of uncoated controls (n = 10) was 128 +/- 37 min. Flap viability after one week (n = 17) and the patency of the coated grafts were investigated histologically. The flap take rate was 65%, the arterial graft patency rate 41%, and the venous graft patency rate 24%. The HS-treated surface combined with the argatroban slow-release system exhibited improvement of flap survival in an intraperitoneal ectopic -free grafting model.

Animals↗