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Biomedical subjects

M Okano

Publications and source records attributed to M Okano.

At least 109 records · Page 6Linked to original sources
PubMed1997

Gammadelta T cells are not essential for control of cutaneous Leishmania major infection in genetically resistant C57BL/6 mice.

As gammadelta T cells are believed to be involved in host defense against Leishmania major, the role of gammadelta T cells in immunity against this parasite was investigated. The growth of L. major was measured in alphabeta (T cell receptor [TCR] alpha -/-) and gammadelta (TCR delta -/-) TCR-deficient C57BL/6 mice and compared with growth in control (C57BL/6) mice. While TCR alpha -/- mice developed nonhealing lesions containing large numbers of parasites following L. major infection, TCR delta -/- and C57BL/6 mice effectively controlled the infection. Following in vitro stimulation, lymph node cells from C57BL/6 mice produced significantly more interferon (IFN)-gamma than those from TCR delta -/- mice during early and late phases of infection; however, both produced similar levels of IFN-gamma at postinfection week 6. Culture supernatants from both TCR delta -/- and C57BL/6 mice contained interleukin-4, at postinfection week 2 only. These results indicate that gammadelta CD3 T cells are not essential for mediating protection against cutaneous L. major infection in C57BL/6 mice.

Animals↗
PubMed1997

Comparison of surgical results of responders and non-responders to the prism adaptation test in intermittent exotropia.

The data for 94 consecutive patients with intermittent exotropia of basic type, ranging from 20 to 40 prism diopters (delta), who preoperatively wore neutralizing prisms for 3 to 5 days, were studied retrospectively. The surgery in 43 patients in whom the amount of increase of angle was 4delta or less was based on the original angle (Group A), while that in 51 patients in whom the magnitude of increase was 5delta or more was based on the increased angle of deviation (Group B). Patients with initial deviation less than 30delta and patients younger than 7 years of age showed an increase of deviation with prism correction. There were no significant differences in surgical results between the two groups at 1 year, and at 3 years; although at 3 years satisfactory motor alignment and binocular function for single vision at distance was higher in Group B than that in Group A.

Adaptation, Ocular↗
PubMed1997

Extremely high serum level of IgE during immunosuppressive therapy: paradoxical effect of cyclosporine A and tacrolimus.

A case of X-linked autoimmune enteropathy was successfully treated with cyclosporine A (CsA) or tacrolimus (FK506) and developed extremely high serum levels of IgE during the immunosuppressive therapy. Serum IgE levels increased from 190 to 1,000-2,500 IU/ml with CsA therapy and as high as 80,000 IU/ml with subsequent FK506 therapy. Serum IgG2 and IgG4 levels were slightly elevated compared to serum IgE levels. Thereafter, serum IgE levels progressively decreased in parallel with a reduced dosage of FK506. Total serum IgG levels and peripheral eosinophil counts, however, showed no significant changes during the course. These observations suggest that both CsA and FK506, potent immunosuppressants, could paradoxically enhance some immune responses, possibly through the action of CsA-/FK506-resistant immune systems.

Anemia, Hemolytic↗
PubMed1997

Anti-tuberculosis activity of quassinoids.

In vitro evaluation of anti-tuberculosis activity was conducted for fifty-six quassinoids isolated in our laboratory from Simaroubaceous plants, Ailanthus altissima (= Aa, 10 compounds), Brucea antidysenterica (= Ba, 16 compounds), Picrasma ailanthoides (= Pa, 14 compounds), and Brucea javanica (= Bj, 16 compounds). Of the compounds tested, shinjulactone K (1), ailanthone (2), shinjudilactone (3), and dehydrobruceantin (4) were the most potent. Although the activities were very low (0-19%), the resulting data provided a picture of structure-activity relationships.

Antitubercular Agents↗
PubMed1997

Inhibitory effects of quassinoid derivatives on Epstein-Barr virus early antigen activation.

Short-term in vitro assays for tumor promoters and antitumor promoters (Epstein-Barr virus activation test) were carried out for semisynthetic quassinoids (3-7), which were obtained by esterification of the C-15 OH group of deacetylated isobrucein-B (2). All the ester derivatives showed higher antitumor promoting activity than that of the potent compound 2. A compound containing a fluorinated aliphatic ester showed the highest potency.

Antigens, Viral↗
PubMed1997

[A case of Sjögren's syndrome with a high titer of anticardiolipin antibody that developed as parkinsonism].

A 50-year-old-male consulted us, complaining of gait disturbance. He was diagnosed as having Parkinson syndrome, but had no benefit of drugs for Parkinson disease. On admission he showed symptoms of parkinsonism such as parkinsonian gait, bradykinesia and muscle rigidity, and recurrent aseptic meningitis. Additionally, his condition was complicated by Sjögren's syndrome, based on the preliminary criteria of Sjögren's syndrome established by the European Community. Because his parkinsonism and meningitis were considered to be caused by Sjögren's syndrome, he was administered corticosteroids, which improved his parkinsonism and aseptic meningitis. The brain MR images in our case did not match those typically reported in cases of central nervous system Sjögren's syndrome (CNS-SS). Although the most common abnormalities are small distinct areas of increased signal intensity on T2-weighted images, the MR images in our case revealed periventricular diffuse areas of increased signal intensity on T2-weighted images. Although his parkinsonism and aseptic meningitis are believed to the effects of vasculitis caused by Sjögren's syndrome, it is also possible that his parkinsonism is related to Binswanger's disease resulting from a high titer of anticardiolipin antibody. Our report proposes a possible relationship between anticardiolipin antibody and CNS-SS when MR images reveal diffuse high intensity areas on T2-weighted images.

Antibodies, Anticardiolipin↗
PubMed1997

[Analysis of induction of MDR1 gene expression by anticancer chemotherapy in bladder cancer].

Using a reverse transcriptase-polymerase chain reaction (RT-PCR)-based quantitative analysis method, we investigated MDR1 mRNA expression levels in 58 bladder cancer specimens to determine whether MDR1 gene expression was induced or enhanced in bladder cancers during chemotherapy. In bladder cancer specimens which were obtained from patients treated with anticancer drugs, significantly higher expression levels of MDR1 mRNA were observed than in those from patients not treated with any anticancer drugs (p = 0.0134, Mann-Whitney U test). From 14 patients who had bladder cancer, clinical specimens were obtained before and after neoadjuvant intra-arterial chemotherapy. The expression levels of MDR1 mRNA were significantly higher in the post-treatment specimens than in the pre-treatment specimens (p = 0.0298, Wilcoxon signed-rank test). Of these 14 patients, 7 patients exhibited increased levels of MDR1 mRNA expression after chemotherapy. In 6 patients, there were no changes in the MDR1 mRNA expression levels before and after chemotherapy. Only one patient exhibited decreased levels of MDR1 mRNA expression after chemotherapy. No significant correlations were observed, between MDR1 mRNA expression levels and effect of the chemotherapy determined microscopically, dosage of anticancer drugs, or patient outcome. In conclusion, this study indicates that MDR1 gene expression in bladder cancers is induced and enhanced during chemotherapy. This overexpression of the MDR1 gene may contribute to resistance to anticancer drugs after repeated chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[A Japanese family with paroxysmal dystonic choreoathetosis].

We present the first report of Japanese family with paroxysmal dystonic choreoathetosis (PDC). At least seventeen individuals of this family in six generations were affected by PDC by autosomal dominant inheritance. The affected individuals had attacks of choreoathetosis/dystonia-like involuntary movements without loss of consciousness. These attacks were precipitated by stress, caffeine, menstruation or ovulation, but not by sudden voluntary movements, which are common precipitating factors in paroxysmal kinesigenic choreoathetosis (PKC). MRI studies of the brain revealed no abnormalities. Some of the family members received clonazepam, or garlic with significant therapeutic effects, while one female case improved after hysterectomy. The pathogenesis of PDC remains unknown, but it could be attributed to a form of channelopathy. Recently, two linkage studies were reported and the PDC locus was identified on chromosome 2q, which may lead to clarify the PDC gene. The family described here may be important for the future biochemical and genetic analyses. We also suspect that PDC may relate to endocrinological abnormalities besides channelopathy.

Adolescent↗
PubMed1996

Epstein-Barr virus-associated hemophagocytic syndrome and fatal infectious mononucleosis.

Virus-associated hemophagocytic syndrome (VAHS) has been thought to be a distinct clinical entity, characterized by intermittent fever, enlarged liver and spleen, and the appearance of hemophagocytosis. Hemopoietic cells are actively ingested by monocytes/macrophages in various organs, including lymph nodes, bone marrow, liver, and spleen. Epstein-Barr virus (EBV) is now thought to be one of the major causes for the development of this unique syndrome. Additionally, VAHS is often associated with fatal infectious mononucleosis (IM). The relationship between EBV-associated VAHS and fatal IM is discussed in this concise review.

Herpesvirus 4, Human↗
PubMed1996

Erythropoietin in mouse avascular yolk sacs is increased by retinoic acid.

Erythropoiesis begins first in the visceral yolk sac (VYS) of the embryo; however, the involvement of erythropoietin (EPO) in yolk-sac erythropoiesis has not been studied adequately. This study reports the expression of EPO in normal and hypoxic VYSs and alterations in yolk sac components induced by retinoic acid (RA) in mice. Gravid mice (plug day = day 0 of gestation) were given one oral dose of 60 mg/kg of RA in olive oil on days 6, 6.5, 7, 7.5, or 8 of gestation and were sacrificed 2.5, 3, or 3.5 days later. Control mice received olive oil without RA. None of the dams developed anemia, but more than 80% of the embryos of the dams that received RA on day 6, 6.5, or 7 of gestation had avascular yolk sacs (AVYs) and anemia. In these AVYs, the adenosine triphosphate (ATP) level was as low as 18-59% of that in the control VYSs. Reverse transcription-polymerase chain reaction and Southern analysis of products demonstrated that mRNA for EPO receptor (EPR) was expressed in both VYSs and AVYs on days 9-11 of gestation, and EPO mRNA was present in VYSs and AVYs on days 9 and 10 of gestation and in vehicle-exposed VYSs on day 11 of gestation. Furthermore, enzyme immunoassay of EPO indicated that AVYs contained more EPO protein than control VYSs. Light microscopy revealed that, in AVYs, in addition to the defective hemopoietic cells, the endodermal layer was exclusively altered: The presence of focal proliferated regions and the separation from the mesenchyme led to a single layer from which some immature cells seemed to be migrating. Immunolocalization of EPO showed its presence in all components of VYSs with a characteristic distribution pattern: In the endodermal layer, cells with positive EPO staining decreased as gestation advanced, and erythroid precursor cells showed positive staining. In AVYs, the proliferated endodermal cells had EPO in abundance; in the separated regions, the distinction between positive and negative EPO staining became clearer than that in the control VYSs, and the immature cells in the lumens also had EPO. EPR was seen on the cell surface of the corresponding cells that reacted to EPO. These findings suggest that VYSs not only produce EPO temporarily but also respond to the oxygen content in situ. EPO and EPR appear to be synthesized in the endodermal cells of the VYSs that are likely to respond to the circumstances induced by RA.

Adenosine Triphosphate↗
PubMed1996

Complications of childhood Sjögren syndrome.

UNLABELLED: Sjögren syndrome (SS) is a common disorder in adults and involves both glandular and extraglandular systems. We report here four cases of childhood SS complicated by chronic thyroiditis, interstitial nephritis or sweat gland inflammation. Additionally, in one of these cases, the central nervous system was involved. All of these complications are common in adult cases. CONCLUSION: Childhood SS is a systemic "ductilitis" or "exocrinopathy" with complications which are commonly observed in adult cases.

Acidosis, Renal Tubular↗
PubMed1996

137Cs concentration in soil samples from an early survey of Hiroshima atomic bomb and cumulative dose estimation from the fallout.

Low background gamma-ray measurement has been performed to determine the 137Cs content in soil samples collected in a very early survey of the Hiroshima atomic bomb. These soil samples were collected just 3 d after the explosion within 5 km from the hypocenter and were not exposed to the global fallout from nuclear weapon tests. Out of 22 samples, 137Cs was detected for 11 samples, and their radioactivities ranged from 0.16-10.6 mBq g-1 at the time of the measurement. A comparison of the 137Cs deposition with the rainfall area within Hiroshima city indicates that the rainfall area was wider than the previously proposed one. Cumulative exposure by the fallout has been estimated to be 0.31 mC kg-1 (0.12 R) in Hiroshima city except for the heavy fallout area and at most 1.0 mC kg-1 (4 R) in the heavy fallout area.

Cesium Radioisotopes↗
PubMed1996

Detection of low-level expression of P-glycoprotein in ACHN renal adenocarcinoma cells.

A highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay and a flow cytometric assay were used to examine ACHN cells for the expression of P-glycoprotein. The expression of P-glycoprotein was detected at the RNA and protein levels in ACHN cells by RT-PCR and flow cytometry, respectively. However, it was below the limit of detection by immunoblotting. The intracellular accumulation of adriamycin in ACHN cells was enhanced by verapamil, cyclosporin A and medroxyprogesterone acetate. Therefore, this study has demonstrated that low-level expression of P-glycoprotein detectable only by RT-PCR and flow cytometry plays a significant role in reducing the intracellular concentration of antitumor agents and thus contributes to the multidrug-resistant phenotype of ACHN cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Epitope analysis of HLA-DR-restricted helper T-cell responses to Der p II, a major allergen molecule of Dermatophagoides pteronyssinus.

T-cell epitopes of Der p II, a major allergen of Dermatophagoides pteronyssinus, were analyzed by using human T-cell clones. We tested 38 cloned T cells from two Japanese patients with allergic rhinitis, and identified at least two peptides (K33-T47 and I58-C73) as helper T-cell epitopes. The former epitope was shown to be restricted by HLA-DRB1*1502, and the latter by HLA-DRB1*0405, both of which are typical Japanese HLA-DR alleles, suggesting that those T-cell epitopes might be important for the onset of house-dust mite allergy in the Japanese population. We prepared 15 analog peptides of the HLA- DRB1*1502-restricted 15-mer peptide. Of those 15 residues, five (F35, L37, A39, F41, and E42) were critical for the epitope activity, and three residues (F35, A39, and E42) seemed to be included in anchor motifs for HLA-DRB1*1502. The epitope peptide was also recognized by HLA-DRB1*1502-positive healthy donors; however, only allergic T cells showed Th2 functions. Antigen-presenting cells of nonallergic donors were able to activate allergic T cells to express Th2 function. This seemed to suggest that antigen recognition of T cells, as well as additional unknown factors which promote Th2, rather than Th1, responses, might be important for the onset of house-dust mite allergy.

Allergens↗
PubMed1996

Strabismus surgery in ocular myasthenia gravis.

We evaluated the efficacy of eye muscle surgery in 4 patients with ocular myasthenia gravis with troublesome diplopia. All patients were in remission and had shown a consistently stable angle of deviation for at least 6 months preoperatively. The extent of eye muscle surgery was based on the degree of deviation in the primary position, and conventional recession and resection procedures were performed in 3 patients and hang-loose recession with an adjustable recession in 1. Single binocular vision was obtained in 3 patients in the primary position without prism correction or compensatory head posture. Electron-microscopic studies on the eye muscle specimens obtained at strabismus surgery revealed non-specific degenerative findings for the muscle fibers and sarcomeric disorganization compared to that in a control extraocular muscle.

Adolescent↗