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Biomedical subjects

M Shinohara

Publications and source records attributed to M Shinohara.

At least 55 records · Page 3Linked to original sources
PubMed2001

[A case of ventricular tachycardia immediately after electroconvulsive therapy in a schinzophrenic patient].

A 33 year-old man weighting, 93 kg with schizophrenia underwent repeated electroconvulsive therapy (ECT) under general anesthesia with thiamylal 200 mg and suxamethonium 80 mg. On his fourth ECT, he developed ventricular tachycardia (VT) immediately after the treatment under general anesthesia with the same agents. The duration of VT was approximately 30 s. The VT returned to sinus rhythm without any special treatment. We speculate that light anesthesia with a small amount of thiopental associated with release of serum potassium caused by suxamethonium induced increased release of catecholamine by ECT to cause VT. After that incident, the patient underwent ECT six times under general anesthesia with thiamylal 250 mg and vecuronium 8 mg, in combination with preventive injection of magnesium sulfate 20 g without any cardiovascular complications. We conclude that the anesthetic management of patients undergoing ECT under general anesthesia should be paid a careful attention for cardiovascular instability, even if they do not have any heart diseases.

Adult↗
PubMed2001

Effect of Actinobacillus actinomycetemcomitans protease on the proliferation of gingival epithelial cells.

OBJECTIVE: Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) has been implicated as an important pathogen in periodontal disease. The aim of this report is to examine the effect of in vitro application of A. actinomycetemcomitans protease on the cell growth, DNA synthesis, and fibronectin level of human gingival epithelial cells. MATERIALS AND METHODS: A. actinomycetemcomitans protease was isolated from the culture supernatant of A. actinomycetemcomitans. Human gingival epithelial cells were incubated in the presence or absence of A. actinomycetemcomitans protease (0.01, 0.1, or I U) for 48 h. The proliferation of cells were tested with the MTT assay and the BrdU assay. The fibronectin level was examined by flow cytometric analysis. RESULTS: The cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells that had been incubated with protease, were lower than the respective values in the untreated gingival epithelial cells; as the dose of A. actinomycetemcomitans protease increased, the cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells decreased. A. actinomycetemcomitans protease may inhibit the proliferation of human gingival epithelial cells. CONCLUSIONS: This protease may play a key role as a major virulence factor in the development of periodontal disease.

Aggregatibacter actinomycetemcomitans↗
PubMed2001

[Adjuvant GM-CSF cytokine gene therapy for breast cancer].

UNLABELLED: The aim of this study was to examine the enhancement of antitumor immunity of irradiated granulocyte macrophage-colony-stimulating factor (GM-CSF) gene-transduced mouse breast cancer cells. METHODS: BALBMC mouse were vaccinated subcutaneously with saline or irradiated mouse breast cancer cells, BALBMC (1 x 10(6)/mouse), infected or not infected with recombinant adenovirus harboring GM-CSF gene on day-7. Mice were injected with parental cells (1 x 10(5)/mouse) on day 0. RESULTS: No mice vaccinated with irradiated GM-CSF producing BALBMC cells developed a tumor during the observation period of up to 16 weeks, whereas 100% of mice injected with saline developed a tumor. CONCLUSION: Our study demonstrates the feasibility of this immunotherapeutic approach as a novel adjuvant cancer therapy after surgery for breast cancer.

Animals↗
PubMed2001

[Docetaxel was effective as neoadjuvant chemotherapy for patients after failure of trans-arterial neoadjuvant chemotherapy with CEF in 2 cases of advanced breast cancer].

Docetaxel was effective as a second line neoadjuvant chemotherapy after failure of cyclophosphamide, epirubicin and 5-FU (CEF) in 2 cases of breast cancer. In Case 1, 4 cycles of trans-arterial neoadjuvant chemotherapy of docetaxel showed a PR effect after failure of 2 cycles of trans-arterial neoadjuvant chemotherapy with CEF. This patient died of pleuritis carcinomatosa 18 months after surgery for breast cancer (latissimus dorsi muscle myocutaneous flap after radical mastectomy). In Case 2, 6 cycles of neoadjuvant venous drip infusion of docetaxel resulted in a CR effect after failure of 2 cycles of transarterial neoadjuvant chemotherapy with CEF. This patient is alive and disease-free 27 months after the operation for breast cancer (same operation as for Case 1). Docetaxel was effective as neoadjuvant chemotherapy for patients after failure of trans-arterial neoadjuvant chemotherapy with CEF.

Aged↗
PubMed2001

[A case of AFP producing early gastric cancer successfully treated with small dose CDDP and 5-FU (PF) therapy].

A case of AFP producing early gastric cancer successfully treated with a small dose of CDDP and 5-FU therapy administered intermittedly is reported with a review of the literature. A 63-year-old male was admitted to our hospital because of liver metastasis with a high level of serum AFP (185.8 ng/ml) three months after gastrectomy. Systemic chemotherapy was performed twice with a regimen of CDDP 20 mg and 5-FU 750 mg/day in 5 days. After hepatic arterial infusion chemotherapy (HAIC) was performed once, the patient obtained partial response according to CT scan and was discharged. After he underwent HAIC once as an outpatient, liver metastasis completely disappeared 5 months after surgery. He was administered oral 5-FU, 150 mg and Krestin 3.0 g/day and underwent HAIC with CDDP 20 mg and 5-FU 750 mg/day every 2 weeks. After serum AFP level was returned to the normal range 7 months after surgery; HAIC was performed every 4 weeks and continued until one year after surgery. One year and 11 months after surgery, serum AFP remains within the normal limit and there is no evidence of recurrence.

Adenocarcinoma↗
PubMed2000

Effect of vitamin E on the degradation of hydrogen peroxide in cultured human umbilical vein endothelial cells.

Vitamin E reacts with radicals such as lipid peroxyl radical (LOO*) and singlet oxygen ((1)O2), and plays a role in inhibiting lipid peroxidation in cell membranes and preventing the oxidation of low-density lipoproteins (LDL). However, only a few studies have investigated the effect of vitamin E on the degradation of hydrogen peroxide (H2O2). Therefore, we examined the effect of vitamin E on glutathione redox cycle-dependent H2O2 degradation activity in human umbilical vein endothelial cells (HUVEC). Confluent HUVEC were cultured for seven days in media containing various concentrations of vitamin E (alpha-tocopherol). The level of glutathione redox cycle-dependent H2O2 degradation activity and the intracellular glutathione level were determined. HUVEC that had been cultured in the presence of higher concentrations of vitamin E had a higher level of H2O2 degradation activity and a higher intracellular content of the reduced form of glutathione (GSH). Therefore, it is suggested that the vitamin E-induced increase in H2O2 degradation activity in HUVEC results from an increase in intracellular GSH level.

Cells, Cultured↗
PubMed2000

Immunomodulation of the neutrophil respiratory burst by endomorphins 1 and 2.

Opioid peptides were found to be released from cells of the immune system during inflammation and stress, and were associated with altered immune responses. Production of superoxide anions by PMA-stimulated neutrophils was markedly inhibited in a concentration-dependent manner by preincubation for 15 min with 10(-18) - 10(-6) M of the endogenous opioid peptides endomorphin 1 or 2. Inhibition was prevented by prior treatment with the micro-opioid receptor-selective antagonist beta-funaltrexamine at 10(-12) - 10(-8) M, but not the delta-opioid receptor-selective antagonist naltrindole. In contrast, endomorphins 1 and 2 caused significant potentiation of superoxide anion production in unstimulated neutrophils. These results suggest that the endogenous opioid peptides endomorphins 1 and 2 may modulate the production of superoxide anions in neutrophils via mu-opioid receptors.

Animals↗
PubMed2000

Tid1/Rdh54 promotes colocalization of rad51 and dmc1 during meiotic recombination.

Two RecA homologs, Rad51 and Dmc1, assemble as cytologically visible complexes (foci) at the same sites on meiotic chromosomes. Time course analysis confirms that co-foci appear and disappear as the single predominant form. A large fraction of co-foci are eliminated in a red1 mutant, which is expected as a characteristic of the interhomolog-specific recombination pathway. Previous studies suggested that normal Dmc1 loading depends on Rad51. We show here that a mutation in TID1/RDH54, encoding a RAD54 homolog, reduces Rad51-Dmc1 colocalization relative to WT. A rad54 mutation, in contrast, has relatively little effect on RecA homolog foci except when strains also contain a tid1/rdh54 mutation. The role of Tid1/Rdh54 in coordinating RecA homolog assembly may be very direct, because Tid1/Rdh54 is known to physically bind both Dmc1 and Rad51. Also, Dmc1 foci appear early in a tid1/rdh54 mutant. Thus, Tid1 may normally act with Rad51 to promote ordered RecA homolog assembly by blocking Dmc1 until Rad51 is present. Finally, whereas double-staining foci predominate in WT nuclei, a subset of nuclei with expanded chromatin exhibit individual Rad51 and Dmc1 foci side-by-side, suggesting that a Rad51 homo-oligomer and a Dmc1 homo-oligomer assemble next to one another at the site of a single double-strand break (DSB) recombination intermediate.

Animals↗
PubMed2000

Toll-like receptor 4-mediated signal pathway induced by Porphyromonas gingivalis lipopolysaccharide in human gingival fibroblasts.

The lipopolysaccharide (LPS) secreted by Porphyromonas gingivalis is implicated in the initiation and progression of periodontitis. Human gingival fibroblasts (HGFs) are the major constituent of gingival connective tissue. In this study, we examined the expression of Toll-like receptor 4 (TLR4) on HGFs by flow cytometric analysis, and studied the signal transduction induced by LPS stimulation of HGFs by enzyme-linked immunosorbent assay, Western blotting, and immunoprecipitation. We show that LPS binds to HGFs, and that HGFs express TLR4 and myeloid differentiation primary response gene 88 (MyD88). P. gingivalis LPS-induced interleukin (IL)-1 production in HGFs was inhibited by anti-TLR4 antibody. P. gingivalis LPS treatment of HGFs activated several intracellular proteins including protein tyrosine kinases, and upregulated the expression of IL-1 receptor-associated kinase (IRAK), nuclear factor-kappaB (NF-kappaB), and activating protein-1 (AP-1), and these events were suppressed by anti-TLR4 monoclonal antibody. Our findings suggest that the binding of P. gingivalis LPS to TLR4 on HGFs activates various second messenger systems.

Antibodies, Monoclonal↗
PubMed2000

Aminoguanidine prevents concanavalin A-induced hepatitis in mice.

Aminoguanidine is an inhibitor of the inducible form of nitric oxide synthase (iNOS). In the present study, the effect of aminoguanidine on concanavalin A-induced hepatitis was examined. Treatment of mice with concanavalin A (10 mg/kg, i.v.) induced interferon-gamma and iNOS mRNA expression in the liver before the elevation of plasma alanine aminotransferase activity. Immunohistochemical study showed the induction of iNOS protein expression in the area of necrosis. Aminoguanidine (1, 3 and 10 mg/kg, i.p.) inhibited the concanavalin A-induced elevation of alanine aminotransferase activity. Aminoguanidine (10 mg/kg, i.p.) did not inhibit concanavalin A-induced interleukin-2, interferon-gamma, tumor necrosis factor-alpha or iNOS mRNA expression in the liver. The plasma nitrite/nitrate level was elevated at 6 and 24 h after concanavalin A treatment. The elevation of nitrite/nitrate was inhibited by aminoguanidine (10 mg/kg, i.p.). From these results, we conclude that nitric oxide formed by iNOS may be involved in the development of concanavalin A-induced hepatitis.

Alanine Transaminase↗
PubMed2000

Accumulation of common T cell clonotypes in the salivary glands of patients with human T lymphotropic virus type I-associated and idiopathic Sjögren's syndrome.

To clarify the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated Sjögren's syndrome (SS), the TCR Vbeta gene usage by the infiltrating lymphocytes in the target organ was examined. The Vbeta families predominantly used in the labial salivary gland (LSG) from the HTLV-I-seropositive (HTLV-I+) SS patients were more restricted than those from the HTLV-I-seronegative (idiopathic) SS patients, and were commonly Vbeta5.2, Vbeta6, and Vbeta7. The single-strand conformation polymorphism analysis revealed that T cell clonotypes with Vbeta5.2, Vbeta6, and Vbeta7 accumulate in the LSG from the HTLV-I+ and idiopathic SS patients. Among junctional sequences of the most dominant Vbeta7 transcripts, the conserved amino acid motif (QDXG: X is any amino acid) was found in six of the five HTLV-I+ SS patients and was also detected in two of the five idiopathic SS patients. Using the probes specific to the motif, the Vbeta7 transcripts with the motif were detected in the LSG from all of the seven HTLV-I+ and five of the six idiopathic SS patients, but not from eight healthy subjects. The Vbeta7 transcripts with this motif were also detected in the HTLV-I-infected T cell lines obtained from the LSG of an HTLV-I+ SS patient. The accumulation of HTLV-I-infected T cells expressing TCR with the conserved motif was thus indicated. These T cells were commonly present in patients with idiopathic SS and are strongly suggested to most likely be involved in the pathogenesis of both HTLV-I-associated and idiopathic SS.

Adolescent↗
PubMed2000

Effects of reversible block of callosal afferent inputs on the response characteristics of single neurons in the cortical taste area in rats.

We examined the change in magnitude of the taste responses of single neurons in the cortical taste area (CTA) in one side by reversibly blocking the CTA in the other side with a local anesthetic, procaine-HCl, in urethane-anesthetized rats. Taste responses of 68 taste neurons were continuously recorded for up to 2 h until recovery from the treatment, and those in 50 of them were found to be affected significantly. No remarkable difference was noted in the spatial distribution of the affected and non-affected neurons in the CTA. Many of the affected neurons were located in layers IV and V of area GI and in layer V of area DI. In most cases, changes in the taste responses of single neurons were in one direction, i.e., either a decrease or an increase, but in a few cases they decreased or increased depending on the stimulus. The taste profile of callosal inputs was estimated by subtracting responses after treatment from the control responses before treatment. The results suggest that the CTAs on both sides are functionally connected by way of callosal fibers as anatomical studies indicate, and that the CTA in one side receives excitatory or inhibitory inputs from the other side.

Anesthetics, Local↗
PubMed2000

Nonlinear time-course of lumbar muscle fatigue using recurrence quantifications.

Isometric skeletal muscle fatigue is usually assumed to be a linear process based upon the monotonic decrease in spectral frequency of the EMG. Since spectral analysis by fast Fourier transform (FFT) constitutes a linear transformation of the data, the present study was designed to reevaluate the time-course of muscle fatigue with a nonlinear tool, recurrence quantification analysis (RQA). Surface EMG recordings were obtained from the multifidus muscle of 17 human subjects during isometric posture-holding of the upper torso. The process of muscle fatigue was found to be linear for 59% of the subjects by FFT criteria, but nonlinear for 76% by RQA criteria. As a demonstrative control, both slow and fast transients occurring within a nonlinear mathematical process could be accurately depicted by RQA, but not by FFT. It is concluded that assessment of EMG patterns by nonlinear techniques can give insight into the time-course of fatiguing muscles attributed to the summation of several nonlinear and competing processes.

Adult↗
PubMed2000

The nucleotide sequence and genome organization of Japanese iris necrotic ring virus, a new species in the genus Carmovirus.

The genome of Japanese iris necrotic ring virus (JINRV) consists of a positive-sense ssRNA of 4014 nucleotides with six major open reading frames (ORFs). A 5'-non-coding region of 31 nucleotides precedes the first initiation codon. Like Carnation mottle virus (CarMV), the 5'-proximal three ORFs encode a 26 kDa protein (p26) and two readthrough proteins, i.e. an 85 kDa putative RNA replicase (p85) and a 99 kDa protein (p99). The central ORF encodes a small 8 kDa protein (p8). The 3'-proximal ORF encodes a 38 kDa capsid protein (p38). Another ORF encoding a 12 kDa protein (p12) overlaps the p99 ORF.JINRV RNA treated with bacterial alkaline phosphatase and tobacco acid pyrophosphatase could not be ligated to an oligoribonucleotide using T4 RNA ligase, indicating that the 5' end of the viral RNA is uncapped. The 3' end is not polyadenylated. Comparison of the genomic organization and the predicted amino acid sequences with those of other viruses confirmed that JINRV should be classified as a member of the genus Carmovirus, family Tombusviridae.

Capsid↗
PubMed2000

Comparison of inhibitory effects of local anesthetics on immune functions of neutrophils.

Immunological effects of a variety of local anesthetics on adhesion, phagocytosis, and the production of superoxide anion and hydrogen peroxide by neutrophils were compared. Neutrophils were isolated by peritoneal lavage from rats, 4 h after injection of 1% glycogen. Lidocaine, mepivacaine, procaine, prilocaine and tetracaine at 1 mg/ml inhibited adhesion, phagocytosis, and the production of superoxide anion and hydrogen peroxide in neutrophils. Moreover, lidocaine, mepivacaine, procaine and prilocaine at 0.1 mg/ml inhibited the production of superoxide anion and hydrogen peroxide but not adhesion or phagocytosis. In contrast, tetracaine at 0.1 mg/ml inhibited phagocytosis, and the production of superoxide anion and hydrogen peroxide but not adhesion. At 0.01 mg/ml, however, tetracaine inhibited the production of superoxide anion and hydrogen peroxide; in contrast, other drugs failed to affect neutrophil function. These results suggest that the local anesthetics may affect adhesion, phagocytosis, and the production of superoxide anion and hydrogen peroxide by neutrophils.

Anesthetics, Local↗
PubMed2000

A study of the association between the prognosis of carcinoma of the mandibular gingiva and the pattern of bone destruction on computed tomography.

OBJECTIVE: To clarify whether the pattern of bone destruction seen on CT is more closely associated with the outcome of carcinoma of the mandibular gingiva than that derived from panoramic radiographs (PR). METHOD: Axial bone window CT scans and PR of 62 patients with carcinoma of the mandibular gingiva were evaluated retrospectively by two oral radiologists for the pattern of bone destruction. Patterns were classified into the three types: erosive, invasive and mixed. The relationship between these patterns with each imaging modality and cumulative recurrence rate, cumulative metastasis rate and cumulative survival rate, calculated by the Kaplan-Meier method, were statistically analysed by the log rank test. RESULTS: The pattern of bone destruction derived from CT was closely associated with the cumulative metastasis rate (P < 0.05), the cumulative recurrence rate and the cumulative survival rate. In contrast, the pattern of bone destruction based on the PR was not associated with the cumulative metastasis rate (P = 0.43), the cumulative recurrence rate (P = 0.44), or the cumulative survival rate (P = 0.5). CONCLUSION: The prognosis of patients with carcinoma of the mandibular gingiva is more closely related to a classification derived from the pattern of bone destruction on CT rather than PR. However, the number of subjects investigated in this study was not large enough to confirm our conclusions statistically. Further studies by other investigators are therefore needed.

Adult↗
PubMed2000

Refractory pretibial myxoedema with response to intralesional insulin-like growth factor 1 antagonist (octreotide): downregulation of hyaluronic acid production by the lesional fibroblasts.

We report a case of refractory pretibial myxoedema (PTM) with Graves' disease in which there was a good clinical response to intralesional injection of the insulin-like growth factor 1 (IGF-1) antagonist octreotide. Intralesional octreotide (200 microg once daily) dramatically improved the tumorous lesions of PTM after 4 weeks, and the lesions remained stable even after reducing the dose to 200 microg once weekly. The amount of hyaluronic acid (HA) in the lesional skin decreased to 5.8 microg mg-1 dry weight from 16.3 microg mg-1 dry weight after 4 weeks of octreotide treatment. IGF-1 showed a dose-dependent stimulatory effect on HA secretion by both normal and patient's fibroblasts at higher concentrations in vitro. Octreotide significantly suppressed IGF-1 induced-HA secretion by the patient's fibroblasts, but not by normal fibroblasts, which suggests that expression of IGF-1 receptor on fibroblasts, or its affinity for IGF-1, are upregulated in PTM, resulting in the oversecretion of HA. These results might suggest that octreotide improves PTM through downregulation of HA production by lesional fibroblasts.

Down-Regulation↗