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M Shioda

Publications and source records attributed to M Shioda.

At least 19 recordsLinked to original sources
PubMed2005

Infected Charcot spine.

STUDY DESIGN: Case report of an infected Charcot spine following spinal cord injury. OBJECTIVE: To describe this very rare pathological condition and the results of surgical treatment. SETTING: A department of orthopaedic surgery in Japan. METHODS: A 44-year-old man presented with a destructive lesion in the lumbo-sacral spine and a fistula in his back. Anterior bone graft, percutaneous external spinal fixation, and suction/irrigation of the wound were performed. After 4 months, posterior spinal instrumentation surgery was carried out. RESULTS: Primary closure of the fistula and complete bone fusion was achieved after the operation. CONCLUSION: Infection of a Charcot spine, although a rare clinical entity, should be considered as a diagnostic possibility in the spinal cord-injured patients. External spinal fixation is a useful method for the unstable spinal lesion with infection.

Adult↗
PubMed2004

Chronic ethanol consumption does not affect action of propofol on rat hippocampal acetylcholine release in vivo.

BACKGROUND: The aim of this study was to examine ethanol-consumption-related changes in the effects of propofol on rat hippocampal acetylcholine (ACh) release. METHODS: Male Sprague-Dawley rats received a solution of ethanol (20% v/v) for 24 weeks while controls received tap water. The effects of propofol were examined by in vivo microdialysis, with ACh release from the hippocampal regions determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). RESULTS: Propofol 50 mg kg(-1) i.p. significantly decreased basal hippocampal ACh release in ethanol-treated and control rats by 50.4 (sem 4.7)% and 38.3 (11.1)%, respectively. Propofol 100 mg kg(-1) i.p. significantly decreased basal hippocampal ACh release in ethanol-treated and control rats by 67.5 (3.7)% and 55.9 (7.4)%, respectively. The reduction in hippocampal ACh release induced by 50 or 100 mg kg(-1) i.p. propofol was not significantly different between ethanol-treated and control rats. There was no significant difference in the duration of sleep between the two groups. CONCLUSIONS: These results demonstrate that chronic ethanol consumption does not augment the inhibitory actions of propofol on rat hippocampal ACh release. These findings appear to be inconsistent with the notion that chronic ethanol intake enhances the propofol-induced inhibition of the hippocampal cholinergic system and related mental dysfunction.

Acetylcholine↗
PubMed2004

Opposite effects of depressant and convulsant barbiturate stereoisomers on acetylcholine release from the rat hippocampus in vivo.

BACKGROUND: It has been shown that the R(-) isomer of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) induces loss of the righting reflex (LRR), while S(+)-MPPB causes pure excitatory effects, including convulsions, in vivo. METHODS: We studied the effects of the depressant and convulsant MPPB stereoisomers on rat hippocampal acetylcholine (ACh) release in vivo, using a brain microdialysis technique in freely moving animals. RESULTS: R(-)-MPPB 60 and 90 mg x kg(-1) i.p. decreased ACh release from the rat hippocampus by 44.1 (8.2)% and 60.8 (8.2)%, respectively. In the hippocampus, the local application of bicuculline, a gamma-aminobutyric acid (GABA)(A) receptor antagonist, 1 micromol litre(-1) antagonized the inhibitory effects of R(-)-MPPB 90 mg x kg(-1) i.p. In contrast, R(-)-MPPB, S(+)-MPPB 60 and 90 mg x kg(-1) i.p. increased ACh release to 151.8 (6.8)% and 169.6 (11.1)% of the basal release, respectively. CONCLUSIONS: Our results demonstrated that R(-)-MPPB decreased, while S(+)-MPPB increased, rat hippocampal ACh release and that the inhibitory effects of R(-)-MPPB may involve the GABA(A) receptor in vivo. These data imply that changes in hippocampal ACh due to these agents may be related to their central inhibitory and stimulatory actions in vivo.

Acetylcholine↗
PubMed2001

Molecular basis for paradoxical carriers of adenosine deaminase (ADA) deficiency that show extremely low levels of ADA activity in peripheral blood cells without immunodeficiency.

Adenosine deaminase (ADA) deficiency causes an autosomal recessive form of severe combined immunodeficiency and also less severe phenotypes, depending to a large degree on genotype. In general, ADA activity in cells of carriers is approximately half-normal. Unexpectedly, healthy first-degree relatives of two unrelated ADA-deficient severe combined immunodeficient patients (mother and brother in family I; mother in family II) had only 1-2% of normal ADA activity in PBMC, lower than has previously been found in PBMC of healthy individuals with so-called "partial ADA deficiency." The level of deoxyadenosine nucleotides in erythrocytes of these paradoxical carriers was slightly elevated, but much lower than levels found in immunodeficient patients with ADA deficiency. ADA activity in EBV-lymphoblastoid cell lines (LCL) and T cell lines established from these carriers was 10-20% of normal. Each of these carriers possessed two mutated ADA alleles. Expression of cloned mutant ADA cDNAs in an ADA-deletion strain of Escherichia coli indicated that the novel mutations G239S and M310T were responsible for the residual ADA activity. ADA activity in EBV-LCL extracts of the paradoxical carriers was much more labile than ADA from normal EBV-LCL. Immunoblotting suggested that this lability was due to denaturation rather than to degradation of the mutant protein. These results further define the threshold level of ADA activity necessary for sustaining immune function.

Adenosine Deaminase↗
PubMed1999

A DNA unwinding factor involved in DNA replication in cell-free extracts of Xenopus eggs.

BACKGROUND: Alteration of chromatin structure is a key step in various aspects of DNA metabolism. DNA unwinding factors such as the high mobility group (HMG) proteins are thought to play a general role in controlling chromatin structure and a specific role in controlling DNA replication. For instance, in the in vitro simian virus 40 replication system, minichromosomes containing HMG-17 replicate more efficiently than those without it, suggesting that HMG-17 enhances the rate of replication of a chromatin template by unfolding the higher-order chromatin structure. At present, however, only limited data suggest an involvement of DNA unwinding factors in DNA replication. RESULTS: We purified from Xenopus eggs a novel heterodimeric factor, termed DNA unwinding factor (DUF), that consists of 87 kDa and 140 kDa polypeptides. DUF unwinds closed-circular duplex DNA in the presence of topoisomerase I, but it does not possess a DNA gyrase activity: it does not introduce negative supercoils into DNA at the expense of ATP hydrolysis. Cloning and sequencing of the cDNAs encoding the two polypeptides revealed that the 87 kDa polypeptide is homologous to a mammalian HMG protein, T160/structure-specific recognition protein. The 140 kDa polypeptide is homologous to yeast Cdc68, a protein that controls the expression of several genes during the G1 phase of the cell cycle by modulating chromatin structure. Immunodepletion of DUF from Xenopus egg extracts drastically reduced the ability of the extract to replicate exogenously added sperm chromatin or plasmid DNA. CONCLUSIONS: We propose that DUF plays a role in DNA replication in Xenopus egg extracts.

Amino Acid Sequence↗
PubMed1998

Determination of adenosine and deoxyadenosine in urine by high-performance liquid chromatography with column switching.

The means of measurement of adenosine and deoxyadenosine in urine was developed by separating adenosine and deoxyadenosine from other compounds using high-performance liquid chromatography with column switchings. This method is simple and convenient since no pretreatment of the urine is needed. Using this method, it could be demonstrated that urinary adenosine was higher in an adenosine deaminase (ADA) deficient patient who had a bone marrow transplant treatment (1.97 micromol/mmol creatinine) and in a heterozygote who had a markedly low erythrocyte ADA activity (1% of control ADA activity) (1.33 micromol/mmol creatinine) as compared to normal subjects (0.22+/-0.09 micromol/mmol creatinine, n=11). It was also noted that urinary deoxyadenosine was below the detection limits in the ADA-deficient bone marrow transplant patient, but it was detected in the heterozygote (3.7 micromol/mmol creatinine). Furthermore, it was also demonstrated that a fructose infusion increased the urinary concentration of adenosine from 0.21+/-0.03 to 2.66+/-1.21 micromol/mmol creatinine in five normal subjects.

Adenosine↗
PubMed1997

CPP32 activation during dolichyl phosphate-induced apoptosis in U937 leukemia cells.

Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre-CPP32 to generate p17. Peptide inhibitors YVAD-cmk and Z-Asp-CH2-DCB (specific to ICE) and DEVD-CHO (specific to CPP32) blocked the dolichyl phosphate-induced apoptosis. The dolichyl phosphate-induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2',5'-dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.

Adenine↗
PubMed1997

Enhancement of apoptosis in developing chick neural retina cells by basic fibroblast growth factor.

To evaluate the role of various growth factors in naturally occurring cell death during development of the neural retina, we examined the effects of such factors on the nuclear morphology and the size of DNA in cultured chick embryonic neural retina cells. Basic fibroblast growth factor (bFGF) increased internucleosomal cleavage of DNA and nuclear fragmentation in a time- and dose-dependent manner. The effect was inhibited by anti-bFGF antibody, suramin, and cycloheximide. Epidermal growth factor, platelet-derived growth factor, nerve growth factor, tumor necrosis factor-alpha, and dexamethasone had no effect. These results provide evidence that bFGF may eventually act as a lethal factor inducing apoptotic cell death during the development of the neural retina in chick embryo.

Animals↗
PubMed1996

Sulfolobus hakonensis sp. nov., a novel species of acidothermophilic archaeon.

We characterized a microbial strain that was isolated from a hot spring at a geothermal area in Hakone, Japan. This isolate, whose lobed-shaped cells were about 1.0 micron in diameter, was a facultative chemolitho-autotroph that required aerobic conditions for growth. The optimum pH was 3.0 (pH range, 1.0 to 4.0), and the optimum temperature was 70 degrees C (temperature range, 50 to 80 degrees C). Lithotrophically, this strain grew on elemental sulfur and reduced sulfur compounds. The G+C content of the genomic DNA was 38.4 mol%. This organism contained calditoglycerocaldarchaeol, which is characteristic of members of the Sulfolobaceae. The levels of 16S rRNA sequence similarity between the new isolate and Sulfolobus acidocaldarius, Sulfolobus solfataricus, and Sulfolobus shibatae were less than 89.8%. Unlike S. acidocaldarius, S. solfataricus, and S. shibatae, the new isolate utilized sugars and amino acids poorly as sole carbon sources, and the levels of DNA-DNA hybridization between the new isolate and these Sulfolobus species were very low. Phenotypically, the new isolate was also distinct from the obligately lithotrophic organism Sulfolobus metallicus. We concluded that the new organism belongs to a new Sulfolobus species, for which we propose the name Sulfolobus hakonensis.

Archaea↗
PubMed1995

The possible involvement of DNA-dependent protein kinase in the phosphorylation of P1 protein in cell-free DNA replication of Xenopus eggs.

We prepared two types of antibodies: one directed against an oligopeptide corresponding to the C-terminal portion of P1 protein and the other against an oligopeptide corresponding to the C-terminal portion of the 80-kDa subunit of the Ku antigen (p80 Ku) essential for DNA-dependent protein kinase (DNA-PK) activity. Immunoprecipitation and immunoblot of sperm nuclei preincubated in Xenopus egg extracts by anti-P1 antibody showed that Xenopus P1 protein is a phosphoprotein with two phosphorylated forms: a hyperphosphorylated form extractable with Triton X-100 and a hypophosphorylated form resistant to Triton X-100. The immunodepletion of extracts with anti-p80 Ku IgG-bound beads caused the hyperphosphorylated form to disappear but hardly affected the hypophosphorylated form of P1 protein. DNA replication was stimulated by immunodepletion of the extract with anti-p80 Ku IgG-bound beads. These findings suggest that DNA-PK down-regulates DNA replication through inhibition of hyperphosphorylation of P1 protein during S phase in this cell-free system.

Amino Acid Sequence↗
PubMed1995

Selective inhibition of DNA polymerase-alpha family with chemically synthesized derivatives of PHYLPA, a unique Physarum lysophosphatidic acid.

PHYLPA, a unique Physarum lysophosphatidic acid (LPA), showed selective inhibition of a family of DNA polymerase alpha, including DNA polymerases alpha, delta and epsilon; but no inhibition of DNA polymerase beta or gamma was observed. To reveal the molecular mechanism of inhibition of DNA polymerases by PHYLPA, four stereoisomers and some other derivatives were synthesized and their effects on DNA polymerases were studied. Among eight derivatives synthesized, PHYLPA-1 (the natural PHYLPA; sodium 1-O-[(9'S,10'R)-9',10'-methanohexadecanoyl]-sn-glycerol 2,3-cyclic phosphate) and PHYLPA-2 (sodium 3-O-[9'S,10'R)-9',10'-methanohexadecanoyl]-sn-glycerol 1,2-cyclic phosphate) were strong and specific inhibitors of a family of DNA polymerase alpha. But their stereoisomers PHYLPA-3 (sodium 1-O-[9'R,10'S)-9',10'-methanohexadecanoyl]-sn-glycerol 2,3-cyclic phosphate) and PHYLPA-4 (sodium 3-O-[9'R,10'S)-9',10'-methanohexadecanoyl-sn-glycerol 1,2 cyclic phosphate) were weak inhibitors, showing the critical importance of stereochemistry of a cyclopropane-containing fatty acid for the inhibitory activity. Some derivatives having no cyclopropane-containing fatty acids--palmitoyl-, oleoyl-, and palmitoleoyl-PHYLPA--showed inhibition to some extent; but 1-palmytoyl and 1-oleoyl lysophosphatidic acid, which has no cyclic phosphate, did not show an apparent inhibitor activity on DNA polymerases. Hence, the extent of the inhibition apparently depends on the stereochemistry of both the fatty acid moiety and the cyclic phosphate.

Animals↗
PubMed1995

The possible involvement of replication-related proteins with a DEAD-box-like motif in cell-free DNA replication of Xenopus eggs.

Two types of antibodies were prepared: one directed against an oligopeptide specific to P1 protein, a mammalian homologue of yeast MCM3, and the other against an oligopeptide with a DEAD box motif, which is a highly conserved sequence in the P1 protein family. Immunoprecipitation of the eluate from anti-P1 family IgG-bound beads, which had been incubated in Xenopus egg extracts, with anti-P1 IgG-bound beads revealed that three proteins were coprecipitated. Two proteins remained in the supernatant after the immunoprecipitation of the eluate from anti-P1 family IgG-bound beads with anti-P1 IgG-bound beads. The immunodepleted extracts with anti-P1 family IgG-bound beads showed much lower DNA replication activity than did mock-treated extracts. Recovery of replication was achieved by supplementing the depleted extracts with both the eluate from anti-P1 IgG-bound beads and the supernatant obtained after the immunoprecipitation of the eluate with anti-P1 IgG-bound beads but not by supplementing the extracts with only the proteins eluted from anti-P1 IgG-bound beads. These findings suggest that some proteins containing a DEAD-box-like motif as well as mammalian homologues of yeast MCM2, MCM3 and CDC46 play an important role in cell-free DNA replication of Xenopus eggs.

Amino Acid Sequence↗
PubMed1995

The association and involvement of some members of the P1 protein family in a cell-free DNA replication of Xenopus eggs.

Two types of antibodies were prepared one directed against an oligopeptide specific to P1Cdc46, a mammalian homologue of yeast CDC46, and the other against an oligopeptide highly conserved in the P1 protein family. Immunoprecipitation with anti-P1Cdc46 antibody revealed that some members of the P1 protein family were coprecipitated with P1Cdc46 in the soluble fraction of Xenopus S phase extracts. Immunoblot analysis showed that all of the coprecipitated proteins reacted with the antibody against an oligopeptide, designated as a DEAD box motif, a highly conserved sequence in the P1 protein family. The immunodepleted extracts with anti-P1Cdc46 antibody-bound beads showed much lower activity of DNA replication than the mock-treated extracts. Recovery of replication was achieved by supplementing depleted extracts with the proteins eluted from anti-P1Cdc46 antibody-bound beads. These findings suggest that the proteins contained in the P1 protein family were associated in the extracts and that the multiprotein complex of the family plays an essential role in a cell-free DNA replication of Xenopus eggs.

Amino Acid Sequence↗
PubMed1995

[Pulmonary infarct hardly differentiated from lung cancer--a case report].

A 64-year-old woman experienced high grade fever, chest pain, and hemosputum. She was admitted to a hospital for evaluation of the infiltrate on an chest X-ray. She was diagnosed as having lung cancer by sputum cytology and transferred to our hospital for operation. The tumor was obscure on palpation during thoractomy, but malignancy could not be ruled out based on analysis of frozen sections. Therefore, a right lower lobectomy and mediastinal lymph node dissection were performed. Pulmonary infarct was not suspected until thrombi were observed in the dissected pulmonary artery. Urokinase and heparin were intravenously administered soon after the operation, but the patient died of pulmonary thromboembolism of the sixth postoperative day. Examination of the operative specimen revealed pulmonary thromboembolism with infarction and no evidence of malignancy. Atypical cells observed in sputum cytology seemed to be derived from basal cell hyperplasia in the area of infarction. Type II alveolar epithelial cell hyperplasia was observed in the periphery of the infarction. These findings seemed to make accurate analysis of frozen sections difficult. An increasing number of cases of pulmonary thromboembolism is being reported in Japan. Therefore, pulmonary infarct with false positive cytology may be encountered more frequently in the future.

Diagnosis, Differential↗
PubMed1995

[Treatment and etiology of spontaneous hemopneumothorax].

The incidence of spontaneous hemopneumothorax is reported to be 1-12% of all cases of spontaneous pneumothorax. We treated 152 cases of spontaneous pneumothorax in the past 8 years and hemopneumothorax occurred in 4 cases which is 2.6% of all cases of spontaneous pneumothorax. All the patients were male and the age ranged from 17 to 30. The total amount of blood loss ranged from 1,200-3,200 mliters and surgical treatment was carried out within 2 days after admission. The bleeding point was visceral pleura of raptured bulla in 2 cases, parietal pleura of the torn adhesion in 1 case, and both visceral and parietal pleura in 1 case. Postoperative course was satisfactory and discharged within 2 weeks after admission in all cases. The authors concluded that early thoracotomy is recommended for spontaneous hemopneumothorax.

Adolescent↗
PubMed1995

[Intradiscal injection of hypertonic saline, phenol-glycerin and osmic acid for the treatment of lumbar disc herniation: an experimental study].

UNLABELLED: The present study was designed to investigate the possible clinical application of hypertonic saline (HS), phenol in glycerin (PHG) and osmic acid (OSA) for intradiscal therapy. MATERIALS & METHODS: HS in several concentrations, 10% PHG and 4% OSA were separately injected into the lumbar intervertebral discs of 60 Japanese white rabbits. Additionally, these substances were placed directly on the dura of the spinal cord of 48 guinea pigs. The animals were sacrificed periodically and were submitted to histological examination using light microscopy. RESULTS: HS caused localized necrosis of the nucleus pulposus cells in a concentration-related fashion. Some discs decreased their height. With time, all the discs generally regained their normal histology. Following administration of 10% PHG, the area of necrosis of the nucleus pulposus cells was more extensive than that by HS, but the regenerative or reparative reaction was not so brisk. Examination of the discs treated with 4% OSA demonstrated severe changes in the nucleus pulposus and the inner annulus fibrosus with resultant disc-space narrowing. The reparative tissue seen after injection of OSA was fibrocartilage in nature. No histological change was seen in the surrounding tissue including the neural tissue following administration of any of the substances. DISCUSSION: Chymopapain is the substance most frequently used for clinical chemonucleolysis. The major clinical complication with chymopapain has been anaphylaxis. The present substances have been used in other clinical applications without reports of anaphylaxis. In this report, HS was shown to hold the potential for reducing intradiscal pressure without induction of scar tissue or significant loss of disc function. PHG and OSA caused considerable but circumscribed histological damage to the disc tissue, but had no such effect on the neural tissues. These data suggested that HS, PHG and OSA may have clinical applications as agents in intradiscal therapy.

Animals↗
PubMed1994

Differential inhibition of eukaryotic DNA polymerases by halenaquinol sulfate, a p-hydroquinone sulfate obtained from a marine sponge.

Halenaquinol sulfate, a p-hydroquinone sulfate obtained from a marine sponge, inhibited the activity of eukaryotic DNA polymerases in varying degrees; the Ki values for DNA polymerases, alpha, beta, delta and epsilon were 1.3, 80, 17.5 and 2.0 microM, respectively, whereas it was less effective against E. coli DNA polymerase I. The inhibition occurred competitively with each of dATP and dTTP, but non-competitively with dCTP, dGTP and the template DNA. Thus, halenaquinol sulfate is demonstrated to be a potential inhibitor of DNA polymerases alpha and epsilon, and be a useful tool for analyzing the dNTP binding sites of DNA polymerases.

Animals↗