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M Mochizuki

Publications and source records attributed to M Mochizuki.

At least 127 records · Page 7Linked to original sources
PubMed1999

Somatic cell mutation induced by sunlight in Drosophila.

There is ample epidemiological evidence showing that sunlight can cause skin cancer in the human. In experimental studies, simulated sunlight or UV lamps are used for demonstrating carcinogenesis and other biological effects. Little studies, however, have been performed using natural sunlight itself. In this work, we have examined the mutagenicity of natural sunlight in Drosophila. The Drosophila wing spot test is useful to detect somatic cell mutations. Third instar larvae in petri dishes were exposed to sunlight (ultraviolet region with < 290 nm wavelength cut off by a plastic cover) in the yard of Okayama University campus (north latitude: 34 degrees 39', east longitude: 133 degrees 55'). The sunlight was mutagenic in Drosophila larvae and produced pyrimidine dimers in their DNA. In the observed mutagenicity, there was dependence on the exposure period and UV fluence. During the two-year monitoring, the highest induction of mutant spot observed was 1.98 total spots/wing on June 25, 1998, and the lowest was 0.64 on December 29, 1998, while non-exposure spontaneous spots were 0.29 and 0.32 on these days, respectively. Thus, solar radiation was mutagenic both in summer and in winter.

Animals↗
PubMed1999

[A report of two cases suggesting positive influence of pregnancy on uveitis activity].

BACKGROUND: Little is known about the influence of pregnancy on uveitis activity. We report two cases suggesting a favorable influence of pregnancy on the clinical course of uveitis. CASE: A 30-year-old woman who was three months pregnant was suspected Vogt-Koyanagi-Harada disease based on the systemic symptoms and ocular findings of iritis and multi-focal serous retinal detachment. She was positive to human leukocyte antigen (HLA)-DR 4. She was treated only with topical corticosteroids. One month later, the retinal detachment disappeared. Six month later, a healthy baby was born. The fundus of both eyes took on a sunset glow appearance and there has been no recurrence of uveitis. The other case was a 23-year-old woman with Behçet's disease who had several episodes of uveitis in a year even on tacrolimus. Because of pregnancy, all systemic drugs including tacrolimus were discontinued since then. Interestingly, the frequency of uveitis was remarkably decreased during the pregnancy. A normal healthy baby was born. The uveitis has almost completely disappeared since parturition until now. CONCLUSION: It is considered that the increase of intrinsic hormone, especially corticosteroid, and some other factors with pregnancy may give the suppressive influence on uveitis in our cases.

Adult↗
PubMed1999

HLA-B27 subtypes and HLA class II alleles in Japanese patients with anterior uveitis.

PURPOSE: Some patients with anterior uveitis (AU) have ankylosing spondylitis (AS) and are HLA-B27 class I-positive. The purpose of this study was to investigate whether there are differences in HLA at the allele level among each group of patients with AU. METHODS: Seventy-three patients with AU were studied. They were classified into three groups: 31 with AS-associated AU, 14 with HLA-B27-associated AU, and 28 with idiopathic AU. Three control groups without AU were used: 138 random subjects, 33 HLA-B27-positive healthy subjects, and 19 HLA-B27-positive patients with AS. DRB1 and DQB1 genotyping was performed using polymerase chain reaction (PCR)-single-strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism. HLA-B27 subtype was determined by PCR-SSCP. RESULTS: There was no difference in the frequency of any class I antigen except HLA-B27 among the patients studied. The frequencies of HLA-DR12 in AS-associated AU and HLA-DR1 in HLA-B27-associated AU showed an increase. In HLA-B27-associated AU, DRB1*0101 and DQB1*0501 were increased compared with HLA-B27-positive control subjects. When HLA-B27 subtype distribution was compared among the groups, the proportion of B*2704 was significantly lower in HLA-B27-associated AU (P = 0.037), however, such a difference was not present in AS-associated groups. CONCLUSIONS: These results indicated that B*2704 seemed to be less susceptible to AU compared with B*2705 in Japanese subjects. The increase of HLA-DR12 and HLA-DR1 in AU may be caused by linkage disequilibrium with B*2704 and B*2705, respectively.

Adult↗
PubMed1998

Differences in the evolutionary pattern of feline panleukopenia virus and canine parvovirus.

Canine parvovirus (CPV) suddenly appeared in the late 1970s after which it showed continuous antigenic changes. Virological and molecular genetic analyses mainly focused on feline panleukopenia virus (FPLV) were conducted in this study because FPLV is the suspected ancestor of CPV; the way in which FPLV evolves may help to explain the emergence of CPV. Analysis of escape mutants against FPLV-specific monoclonal antibody showed that viruses possessing CPV-like properties were not easily detected in FPLV virus stocks. Phylogenetic analysis revealed that the nonstructural protein 1 (NS1) and capsid protein 2 (VP2) genes of FPLV changed with time. A similar tendency, however, was not observed in the FPLV VP2 proteins. In contrast, the topology of the phylogenetic tree of VP2 proteins of CPV basically concurred with that of the VP2 genes. Analysis of the ratio of nonsynonymous and synonymous substitutions revealed that synonymous substitutions exceeded nonsynonymous substitutions in both the NS1 and VP2 genes of FPLV, even when the analysis focused on specific regions in the VP2 gene that are known to be located on the capsid surface. Comparison of the CPV VP2 genes revealed that nonsynonymous substitution was found to dominate over synonymous substitution in one specific region in the VP2 gene. These results suggested that FPLV has changed mainly by random genetic drift. In contrast, after the appearance of CPV, changes in the CPV VP2 gene appear to be partly selected by certain positive selection forces. CPV and FPLV are known to be closely related viruses genetically and biologically, but the evolutionary mechanisms of the two viruses appeared to be different.

Amino Acid Substitution↗
PubMed1998

Intracellular localization and release of eotaxin from normal eosinophils.

Eotaxin is a potent and selective CC chemokine for eosinophils and basophils. We established several monoclonal antibodies (Mabs) allowing the neutralization and measurement of human eotaxin. Using the Mabs as probes, we demonstrated that normal eosinophils contained intracellular granule-associated eotaxin. Quantification of cell-associated eotaxin in different leukocyte subsets revealed that it was principally expressed in eosinophils. Finally, we showed that normal eosinophils released eotaxin upon stimulation with either of two secretagogues, C5a or ionomycin. These findings raise the possibility that eosinophil-derived eotaxin contributes to the local accumulation of eosinophils at the site of inflammation.

Animals↗
PubMed1998

Transoral joint release of the dislocated atlantoaxial joints combined with posterior reduction and fusion for a late infantile atlantoaxial rotatory fixation. A case report.

STUDY DESIGN: A case of a late infantile atlantoaxial rotatory fixation is reported for which transoral anterior release was performed. OBJECTIVES: To report a patient who underwent transoral anterior release of the dislocated atlantoaxial joint for a case of late infantile atlantoaxial rotatory fixation and quadriparesis. SUMMARY OF BACKGROUND DATA: Infantile atlantoaxial rotatory fixation is diagnosed easily by using recently developed imaging techniques such as computed tomography, magnetic resonance imaging, and three-dimensional computed tomography. Nevertheless, patients in whom the condition has been overlooked still are encountered, and the reduction in these patients becomes impossible by traction or by simple posterior open reduction. Few reports on the management of type II-IV chronic atlantoaxial rotatory fixation in which an anterior surgery was performed exist in the literature, and no report exists in which atlantoaxial joint release on the both sides was attained. METHODS: A 9-year-old girl had a type III atlantoaxial rotatory fixation and quadriparesis. She received direct skull traction and repeated manual reduction while she was awake or under general anesthesia. Neither reduction nor movement was obtained, according to the radiographs. Therefore, it was necessary to perform open reduction posteriorly and transorally to release the fixed and contracted joints between C1 and C2. RESULTS: After the anterior release of the joints, there was an inherent force preventing a complete rotational reduction. However, after a successful posterior reduction and fusion, and for more than 4 years after surgery, neither rotatory displacement nor neurologic deterioration was noted. CONCLUSIONS: The authors suggest that careful transoral anterior release of the atlantoaxial joint permits successful reduction in a case of chronic fixed atlantoaxial rotatory fixation combined with cord compression.

Atlanto-Axial Joint↗
PubMed1998

Delayed production of biologically active O-glycosylated forms of human eotaxin by tumor-necrosis-factor-alpha-stimulated dermal fibroblasts.

Since a number of inflammatory skin diseases are characterized by selective eosinophil infiltration preferentially in the dermis, we speculated that dermal fibroblasts might represent a potential cellular source of eosinophil-selective attractants. Cultivated dermal fibroblasts treated with tumor necrosis factor alpha secreted, not before day 3 of stimulation, eosinophil-specific chemotactic activity. Purification of this activity revealed a heparin-binding protein with an apparent molecular mass of 13 kDa in SDS/polyacrylamide gel electrophoresis. Peptide mapping with subsequent amino acid sequence analyses revealed it to be human eotaxin. Natural eotaxin preparations contain 50% N-terminally truncated forms missing two or three amino acids. It is O-glycosylated at Thr71, resulting in at least two sialylated O-glycosylated variants. Electrospray ionization mass spectrometric analyses revealed the natural eotaxin preparation to be heterogeneous with principal masses of 9033 Da and 9317 Da. Natural eotaxin stimulated eosinophil chemotaxis with identical potency and efficacy as recombinant human eotaxin. Neither neutrophils, monocytes or lymphocytes responded towards natural eotaxin preparations indicating that N-terminal truncation and O-glycosylation did not affect the cell-specificity of chemotactic activity. Treatment of eosinophils with natural eotaxin desensitizes chemotactic responses towards eotaxin, regulated an normal T-lymphocyte expressed and secreted (RANTES) and monocyte chemotactic protein 3 (MCP-3), whereas RANTES and MCP-3 were unable to desensitize natural eotaxin-dependent responses.

Amino Acid Sequence↗
PubMed1998

Mutagenicity of isomeric alkanediazotates, precursors for ultimate alkylating species of carcinogenic N-nitroso compounds.

Alkanediazohydroxides are common key intermediates in carcinogenesis and mutagenesis of N-nitroso compounds, which are widely found in human environment. Mutagenicity of (E)- and (Z)-potassium alkanediazotates, as precursors of corresponding alkanediazohydroxides were evaluated to investigate the effect of geometric isomerism and also the effect of alkyl groups on their biological activity. Mutagenicity of N-nitroso-N-alkylureas which spontaneously produce alkanediazohydroxides after non-enzymatic hydrolysis were also tested in comparison to that of the corresponding diazotates and other activated chemical species of N-nitrosamines. When the mutagenicity was assayed in three microbial strains, Salmonella typhimurium TA1535, and Escherichia coli WP2 and WP2 uvrA, the order of mutagenic potency of the compounds with the same alkyl group was as follows; (E)-diazotates > (Z)-diazotates > nitrosoureas. The effect of alkyl groups on the mutagenic potency was different in Salmonella strain and in E. coli strains, and this result could be explained by the efficiency of O6-alkylguanine-DNA alkyltransferase. In each bacterial strain, this effect of alkyl groups was similar in mutagenicity induced by (E)- and (Z)-diazotates, N-nitroso-N-alkylureas and other activated N-nitrosodialkylamines such as alpha-hydroxy nitrosamines. The geometrical isomerism affected the mutagenicity of (E)- and (Z)-potassium alkanediazotates, and the result suggested that alkanediazohydroxides react through diazonium ions in a cage rather than through free alkyldiazonium ions which have no geometrical isomerism. Our results confirmed that (E)-potassium alkanediazotates, (Z)-potassium alkanediazotates and N-nitroso-N-alkylureas all decomposed through diazohydroxides, and that alkanediazohydroxides are the active alkylating species of N-nitroso compounds, and also that the geometrical isomerism is important for carcinogenic N-nitroso compounds to show their biological activity.

Alkylating Agents↗
PubMed1998

IL-4 induces eotaxin: a possible mechanism of selective eosinophil recruitment in helminth infection and atopy.

A common feature of some parasitic infections and allergic and atopic skin diseases is the involvement of Th2 lymphocytes and the dermal appearance of eosinophils (Eos). Because Th2 lymphocytes apparently do not release Eo attractants, we addressed the question of whether the Th2 cytokine IL-4 induces its production in dermal fibroblasts. We therefore stimulated fibroblasts with IL-4. HPLC investigation of supernatants revealed a single Eo chemotactic protein, which was purified to homogeneity giving a single 13-kDa band upon SDS-PAGE analyses. Peptide mapping with subsequent amino acid sequencing revealed an Eo-selective chemotaxin, which consists of a mixture of N-terminally truncated and O-glycosylated forms of the chemokine eotaxin. Other chemokines such as RANTES, MCP-3, MCP-4, or MIP-1alpha were not detected as Eo chemotaxins under these conditions. Using reverse transcriptase-PCR techniques, we found that IL-4 dose and time dependently induces eotaxin mRNA in dermal fibroblasts. Stimulation with IL-4 and TNF-alpha caused a 10- to 20-fold increase of the release of three biochemically different eotaxin forms, each consisting of a mixture of N-terminally truncated and O-glycosylated variants having the same backbone amino acid sequence but different specific activities. Our findings support the hypothesis that eosinophil recruitment seen in IL-4-mediated skin reactions, at least in part, may be due to Th2 cytokine-mediated induction of eotaxin in dermal fibroblasts.

Amino Acid Sequence↗
PubMed1998

A proposal for analysing the acid-base balance at steady state in vivo.

[H+] in plasma in vivo is composed of a PCO2-dependent component [H+]* and a PCO2-independent component delta [H+]. The correct equation for the calculation of [H+]* was found by referring to the slope of the regression line between the venous-arterial difference of delta [H+] and that of PCO2. Using [H+]*, the buffer value in vivo and the base excess were calculated. Since the base excess was hyperbolic against delta [H+] and dependent on PCO2, we concluded that it was better to use delta [H+] rather than the base excess to evaluate the metabolic change of [H+] in plasma.

Acid-Base Equilibrium↗
PubMed1998

Risk factors for proliferative vitreoretinopathy.

Proliferative vitreoretinopathy (PVR) is one of the major causes of failure in retinal detachment surgery. To prevent PVR, it is necessary to determine factors predisposing its development. In primary PVR, large retinal tears, long duration of retinal detachment, vitreous hemorrhages, aphakia and choroidal detachment were demonstrated as clinical risk factors for PVR. In postoperative PVR, it was revealed that large breaks, pre- and postoperative choroidal detachment, minor intra- or postoperative hemorrhages, signs of uveitis, extensive retinal detachment, vitrectomy, cryopexy, air injection and preoperative PVR were risk factors for PVR by multivariate analysis. Almost all risk factors for PVR are associated with intravitreal dispersion of retinal pigment epithelial (RPE) cells or breakdown of the blood-ocular barrier which are prerequisite to development of PVR.

Animals↗
PubMed1998

Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats.

Theanine, r-glutamylethylamide, is one of the major components of amino acids in Japanese green tea. Effect of theanine on brain amino acids and monoamines, and the striatal release of dopamine (DA) was investigated. Determination of amino acids in the brain after the intragastric administration of theanine showed that theanine was incorporated into brain through blood-brain barrier via leucine-preferring transport system. The concentrations of norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5HIAA) in the brain regions were unaffected by the theanine administration except in striatum. Theanine administration caused significant increases in serotonin and/or DA concentrations in the brain, especially in striatum, hypothalamus and hippocampus. Direct administration of theanine into brain striatum by microinjection caused a significant increase of DA release in a dose-dependent manner. Microdialysis of brain with calcium-free Ringer buffer attenuated the theanine-induced DA release. Pretreatment with the Ringer buffer containing an antagonist of non-NMDA (N-methyl-D-aspartate) glutamate receptor, MK-801, for 1 hr did not change the significant increase of DA release induced by theanine. However, in the case of pretreatment with AP-5, (+/-)-2-amino-5-phosphonopentanoic acid; antagonist of NMDA glutamate receptor, the theanine-induced DA release from striatum was significantly inhibited. These results suggest that theanine might affect the metabolism and/or the release of some neurotransmitters in the brain, such as DA.

2-Amino-5-phosphonovalerate↗
PubMed1998

Bullous pemphigoid showing unusual ocular changes.

We describe a 68-year-old Japanese woman with erythematous and bullous skin lesions. Antibasement membrane zone antibodies of IgG class were detected in the serum, which reacted with the 230 kDa and 180 kDa bullous pemphigoid antigens on immunoblot analysis. The patient later developed corneal opacity in both eyes and a detachment of the epithelium in the centre of the cornea. However, no change was seen in the conjunctiva. These ocular lesions are different from those of cicatricial pemphigoid. The ocular lesions could be reproduced by injection of IgG from this patient into the stroma of the corneas of rabbits. Both the cutaneous and ocular lesions responded well to oral corticosteroid therapy. We diagnosed this patient as having bullous pemphigoid associated with a unique ocular lesion.

Aged↗
PubMed1998

Topical liposome-encapsulated FK506 for the treatment of endotoxin-induced uveitis.

PURPOSE: Liposome preparations of FK506 improve the penetration of topically administered drug into the aqueous humor. The purpose of the experiment was to compare topically administered highdose oil-dissolved FK506 (OD-FK506) and low-dose liposome-bound FK506 (LB-506) for the treatment of endotoxin-induced uveitis (EIU). METHODS: Endotoxin-induced uveitis was produced in female Lewis rats with Salmonella typhimurium endotoxin. Four hours prior to endotoxin injection, one eye received 20 mul eyedrops every four hours containing either high-dose OD-FK506 at 3 mg/ml (N = 20), low-dose LB-FK506 at 0.16 mg/ml (N = 19), prednisolone acetate 1% (N = 20), or empty liposomes (N = 20). Eyes were enucleated 24 hours after endotoxin injection and inflammatory cells were counted on histologic sections by two masked observers. RESULTS: The mean number of infiltrating inflammatory cells per section +/- S.E.M. was 127.8 +/- 20.1, 76.8 +/- 16.7, 75.0 +/- 19.1, and 3.6 +/- 0.4 for animals treated with empty liposomes, LB-FK506, OD-FK506, and prednisolone acetate, respectively. The difference in inflammation between the empty liposome controls and the LB-FK506- and OD-FK506-treated animals was statistically significant (p = 0.03 and p = 0.02, respectively). The difference in inflammation between the high-dose OD-FK506- and low-dose LB-FK506-treated animals was not statistically significant (0 = 0.94). CONCLUSION: In this study, low-dose LB-FK506 and high-dose (OD-FK506) were both effective in inhibiting EIU. Higher concentrations of LB-FK506 are being developed and should augment the therapeutic effect of topical FK506.

Administration, Topical↗
PubMed1998

Provirus load in patients with human T-cell leukemia virus type 1 uveitis correlates with precedent Graves' disease and disease activities.

We previously demonstrated the increased provirus load in the peripheral blood of patients with human T-cell leukemia virus type 1 (HTLV-1) uveitis (HU). To delineate the relevance of the increased provirus load to clinical and immunologic parameters, we studied the correlation between them. Seventy-nine HU patients (24 male and 55 female) were included in the study, with their informed consent. Plasma samples and genomic DNA of the peripheral blood mononuclear cells were isolated and the provirus load was estimated by semi-quantitative polymerase chain reaction of the gag region sequence. Serum levels of anti-HTLV-1 antibodies and soluble IL-2R were determined by electrochemiluminescence immuno assay and by ELISA, respectively. Disease activities were assessed and graded 0 to 4 according to the evaluation system. Recurrence of the disease during the follow-up period was diagnosed ophthalmologically. The provirus load was significantly higher in the HU patients after Graves' disease (GD) than in those without GD (P<0.05). It correlated with disease activities assessed in terms of vitreous inflammation and interval to recurrence (both P<0.05). In the HU patients without GD, it correlated with the serum levels of soluble IL-2 receptor (P<0.01), and nearly with those of HTLV-1 antibody (P=0.063). These correlations were not found in the HU patients after GD under methimazole treatment. The results suggested a direct involvement of HTLV-1-infected cells in the pathogenesis of uveitis, and raise the possibility that hyperthyroidism may contribute to the clonal expansion of HTLV-1-infected cells.

Graves Disease↗
PubMed1998

TAP polymorphism is not associated with ankylosing spondylitis and complications with acute anterior uveitis in HLA-B27-positive Japanese.

HLA-B27 is associated with the etiology of ankylosing spondylitis (AS) and acute anterior uveitis (AAU). Transporter associated with antigen processing (TAP) 1 and TAP2 polymorphism influences the range of peptide presented by HLA class I molecules. In this report, contribution of TAP polymorphism to the susceptibility to AS and AAU was studied in HLA-B27-positive Japanese individuals. Patients were classified into three groups: 16 AS patients, 14 AAU patients and 22 patients with both AS and AAU. Twelve HLA-B27-positive healthy individuals were included as a control. TAP polymorphism was detected by PCR-RFLP methods. Significant differences in frequencies of TAP1 alleles were not found between patient groups. None of the TAP2 frequencies showed increased or decreased frequencies compared with HLA-B27-positive healthy controls. In comparison with a random Japanese control, TAP2D allele frequency was significantly increased in the AAU group, but failed to reach a significant level in a group consisting of the AAU-only patients and the patients with both AS and AAU. All of the patient groups were noted to have a significantly increased prevalence of the TAP2H allele as compared to random controls; however, the higher frequency of this allele was detected in HLA-B27 healthy controls as well. These observations suggest a linkage disequilibrium between TAP2D, TAP2H and HLA-B27 in Japanese.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Theanine-induced reduction of brain serotonin concentration in rats.

Following the administration of theanine, the brain tryptophan content significantly increased or tended to increase, but the contents of serotonin and 5-hydroxyindole acetic acid (5HIAA) decreased. The use of inhibitors of serotonin metabolism enable us to speculate that theanine reduced serotonin synthesis and also increased serotonin degradation in the brain.

Animals↗