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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 253 records · Page 14Linked to original sources
PubMed1999

Perifoveal microcirculation in eyes with epiretinal membranes.

BACKGROUND/AIMS: Eyes with epiretinal membranes (ERMs) often have alterations of retinal vessels. The authors studied perifoveal microcirculation in eyes with epiretinal membranes (ERMs) using scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured as an index of perifoveal microcirculation by SLO fluorescein angiography in 26 eyes with ERMs (19 eyes with idiopathic epiretinal membranes, seven eyes with epiretinal membranes after retinal detachment surgery) before and 6 months after vitreous surgery, and in 23 healthy control subjects. RESULTS: The mean CFV was significantly reduced in eyes with ERMs compared with healthy controls (p=0.012), and the postoperative mean CFV was significantly increased compared with the preoperative mean CFV (p=0.041). CONCLUSION: Significant changes of capillary blood flow velocity in the perifoveal areas were observed between normal subjects and eyes with epiretinal membranes. This indicates that eyes with ERMs show abnormal haemodynamics in the perifoveal capillaries.

Adult↗
PubMed1999

Ultrastructural changes of erythrocyte membrane skeletons in chorea-acanthocytosis and McLeod syndrome revealed by the quick-freezing and deep-etching method.

The shapes of acanthocytic erythrocytes have been thought to be related to changes of the organization of the membrane components. In this study, acanthocytes from a patient with chorea-acanthocytosis and a patient with McLeod syndrome were examined. These acanthocytes had a greater tendency to form spikes than normal erythrocytes in an incubation culture system, indicating their weakness against membrane tension. The membrane skeletons of erythrocytes from both patients were examined by our erythrocyte-splitting method followed by the quick-freezing and deep-etching method. The ultrastructural organization of the membrane skeletons was heterogeneous even in individual erythrocytes, indicating regional changes in the compactness of their meshworks. In the process of erythrocyte splitting, some erythrocyte membranes became reversed and protruded into the cytoplasmic side. In these regions, there were fewer filamentous structures. The focal membrane skeletal changes, which are probably one of the factors that induce the phenotype of an acanthocytic erythrocyte, were demonstrated for the first time by this method.

Acanthocytes↗
PubMed1999

Immunocytochemical study of endocytotic structures accumulated in HeLa cells transformed with a temperature-sensitive mutant of dynamin.

Dynamin is a 100-kD GTPase, which is required for clathrin-mediated endocytosis. Recent studies have revealed that dynamin is closely involved in clathrin-coated vesicle formation. In this study we investigated the ultrastructure of endocytotic structures accumulated in HeLa cells that were transformed with a temperature-sensitive (ts) mutant of dynamin to clarify which step was blocked in dynts cells. Endocytosis of transferrin receptors was restricted at the level of surface-connected membrane structures. Tubular and vesicular membrane invaginations were accumulated in the cells' peripheral regions, suggesting that the endocytosis was blocked just before the pinching-off steps in coated vesicle formation. The "collared" tubes, which were reported to be localized in nerve terminals in shibirets1 flies and GTPgammaS-treated synaptosomes, were not observed in the dynts cells even at nonpermissive temperature. The distribution pattern of dynamin in deeply invaginated coated pits in dynts cells was similar to that in dynwt cells but not to that in dynK44A cells, which are other endocytosis-defective mutant cells. These morphological data suggest that dynts blocked the pinching-off steps in clathrin-coated vesicle formation, which may be caused by a different mechanism from that of dynK44A cells.

Cell Membrane↗
PubMed1999

Transient up-regulation of myotonic dystrophy protein kinase-binding protein, MKBP, and HSP27 in the neonatal myocardium.

Myotonic dystrophy protein kinase (DMPK)-binding protein, MKBP, has high homology with a small heat shock protein, HSP27. Western blotting analyses showed that MKBP level in rat heart rapidly increased, with a sharp peak at one week after birth (3-fold the level at the fetus), but that it rapidly decreased (1/10 of peak value at 13 weeks). Human myocardium also showed similar age-dependency. Similar but small increase of HSP27 was observed in the neonatal rat myocardium, but not in constitutive and inducible forms of HSP70. Immunofluorescence analysis localized MKBP at the Z lines and intercalated discs in the rat myocardium. MKBP may protect actin cytoskeleton or other proteins of heart muscle against oxidative stress in the neonate.

Age Factors↗
PubMed1999

Translocation of HSP27 and MKBP in ischemic heart.

HSP27 and MKBP translocate from the cytosolic to myofibril fraction in ischemic rat heart as demonstrated by immunoblotting. Immunohistochemistry analysis showed that ischemia enhances the Z line labeling of HSP27 and MKBP. Two dimensional gel electrophoresis showed that ischemia increases the hyperphosphorylated form of HSP27. These data suggest that HSP27 and MKBP may be involved in the Z line protection against postischemic reperfusion injury.

Actins↗
PubMed1999

[Statistical analysis of fabrication of indirect single restorations].

A statistical survey based on laboratory records was performed on the number of indirect restorations fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also carried out with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. Based on the results of this statistical survey, the conclusions were as follows: 1. A total of 9,126 indirect restorations were fabricated during the six month period in 1997; among them, 8,007 (87.7%) restorations were covered by health insurance and 1,119 (12.3%) restorations were not. 2. The most common restoration was the cast post and core (28.6%), followed by full crowns (18.5%) and removable partial dentures (15.6%). On the other hand, the least number were post crowns (0.03%) and resin jacket crowns (0.2%). 3. When making a comparison with the data in 1986, an increase in the number of removable partial dentures and a decrease in the number of inlays were the most distinctive features. 4. For anterior teeth, resin-veneered crowns were most common, especially for lower teeth. The percentage of restorations, which were not covered by health insurance, decreased from 45.0% (in 1986) to 12.3% (in 1997).

Crowns↗
PubMed1999

[Statistical analysis of fabrication of fixed and removable partial dentures].

A statistical survey based on laboratory records was performed on the number of fixed and removable partial dentures fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also performed with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. From the findings of this statistical survey, the conclusions were as follows: 1. A total of 2,478 fixed and removable partial dentures were fabricated during the six month period in 1997. 2. The 3-unit fixed partial denture (bridge) was most common (63.1%) and the number of bridges decreased as the number of units increased. 3. For the single missing tooth, a fixed bridge was more popular (81.0%) than a removable partial denture. 4. For two missing teeth, there was no difference between the number of fixed bridges and removable partial dentures. 5. The percentage of fixed and removable partial dentures, which were not covered by health insurance, decreased to a large extent in comparison with the survey in 1986.

Denture, Partial, Fixed↗
PubMed1999

New iris retractor for pupil dilatation during anterior vitrectomy: double-hook iris retractor.

To report a new iris retractor as a tool for pupillary dilatation in eyes with a small pupil. This instrument was designed to prevent the retractor from dropping out of corneal incision, especially during anterior peripheral vitrectomy requiring a scleral indentation. A new iris retractor was designed with the top in the form of a double-hook, based on the conventional flexible iris retractor. The new instrument was used in 16 eyes, and the conventional flexible iris retractor was used in 14 eyes, with proliferative retinopathy or proliferative diabetic retinopathy in cases in which anterior vitrectomy was performed. The number of times that the instrument has been replaced were recorded. The conventional flexible iris retractor was replaced at mean number of 4.2 times, while the new iris retractor was replaced a mean number of 0.3 times during vitreous surgery. The difference was statistically significant (P = 0.009, Mann-Whitney test). The new iris retractor can easily hook onto the iris and is useful in anterior vitrectomy.

Eye Diseases↗
PubMed1999

[Treatment strategy for and clinical results in patients with recurrent esophageal cancer].

In the current study, we evaluate the frequency and pattern of recurrence in patients with esophageal cancer. Among 116 patients who had undergone curative resection for esophageal cancer, recurrence was found in 33 (28.4%). The most frequent pattern of recurrence was lymphatic (54.5%), followed by the mixed type (18.2%), hematogenic (12.1%), locoregional (12.1%), and anastomotic (3.0%) patterns. Recurrence was found within 1 year after surgery in 18 (54.5%), within 2 years in 12 (36.4%), and within 3 years in 3 (9.1%). In patients with recurrence, lymph node metastasis and advanced stage were seen more frequently than in those without recurrence. The prognosis for patients with recurrent disease is poor. However, in some cases surgical resection, systemic chemotherapy, hepatic arterial infusion chemotherapy, and local radiation therapy have proven to be effective. The most appropriate therapy should be selected based on the region of extension and patient performance status to provide optimum treatment of recurrent disease.

Aged↗
PubMed1999

Association of MICA gene and HLA-B*5101 with Behçet's disease in Greece.

PURPOSE: Behçet's disease (BD) is known to be associated with HLA-B51 in many different ethnic groups. Recently MICA, a member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), was identified near the HLA-B gene, and a triplet repeat microsatellite polymorphism was found in the transmembrane (TM) region. Because a strong association with BD of one particular MICA-TM allele, A6, was shown in a Japanese population, the present study was conducted to investigate microsatellite polymorphism in Greek patients with BD to know whether this association is generally observed in BD occurring in other populations. METHODS: Thirty-eight Greek patients with BD and 40 ethnically matched control subjects were examined for MICA microsatellite polymorphism using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology. RESULTS: Similar to the Japanese patients with BD, the phenotype frequency of the MICA-TM A6 allele was significantly increased in the Greek patients with BD (50.0% in control subjects versus 86.8% in BD cases), with an odds ratio (OR) of 6.60 (P = 0.0012). The MICA-A6 allele was found in a high frequency both in males and females (weighted OR = 6.68; P = 0.0017). No association was found between the A6 allele and several disease features. A strong association exists between the MICA-TM A6 allele and the B*5101 allele in both the control subjects and patients with BD (weighted OR = 44.39; P = 0.0000023). CONCLUSIONS: This study revealed in Greek patients a strong association of BD with a particular MICA-TM allele, MICA-A6, providing insight into the molecular mechanism underlying the development of BD.

Adult↗
PubMed1999

[Study on CAF + medroxyprogesterone acetate (MPA) therapy for advanced or recurrent breast cancer--comparison between MPA 600 mg and 1,200 mg. Kyushu CAFT Therapy Study Group (Third Study)].

To find the optimal dose of MPA for combined use with CAF therapy for advanced or recurrent breast cancer, a randomized comparative study with a MPA 1,200 mg group and 600 mg group was carried out multi-institutionally. The response rate of complete cases was 37.5% (12/32) in the 1,200 mg group and 36.6% (15/41) in the 600 mg group, showing no difference between the two groups. There were no differences in either the duration of response or the survival term. The major adverse effects and abnormal laboratory test values included alopecia, nausea and vomiting, general fatigue, anorexia and leukopenia, with no difference in incidence between the groups. Moon face, genital hemorrhage and body weight increase, which are thought to be caused by MPA, were found in both groups without a significant difference in incidence. The results of this study revealed no differences in effectiveness or safety between MPA 1,200 mg and 600 mg, suggesting that MPA for combined use with CAF is fully effective at a dose of 600 mg.

Adult↗
PubMed1999

[A case of Sjögren's syndrome with retrobulbar optic neuritis and cutaneous vasculitis].

A 52-year-old woman, diagnosed as having Sjögren's syndrome by parotid sialography and lip biopsy after a two years history of recurrent purpuric rashes on her lower extremities, was admitted to our hospital because of visual disturbance in March 1998. On presentation at the department of ophthalmology, her right visual acuity was light perception, and laboratory findings showed elevated levels of antinuclear antibody and anti-Ro/SS-A and anti-La/SS-B antibodies. Cerebrospinal fluid analysis showed mild pleocytosis and elevated levels of total protein and Q-albumin. The IgG-index was within normal level and no oligoclonal band was found. Magnetic resonance imaging showed increased signal intensity at the right optic nerve. After treatment with m-PSL pulse therapy, her visual acuity recovered to 0.08. When prednisolone was gradually tapered to the dose of 30 mg per day, she was transferred to our department because of high grade fever and pancytopenia. She also suffered from palpable purpura in her extremities extending the trunk, whose pathological diagnosis was leukocytoclastic vasculitis. The immunohistochemical examination showed depositions of IgG and C1q. After two additional cycles of mPSL pulse therapies, clinical improvement was achieved. The titers of von Willebrand factor and thrombomodulin correlated with her clinical improvement. Patients with Sjögren's syndrome can develop extra-grandular complications, including neurologic and cutaneus diseases, it is important to understand the role of SS-A-B antibodies in the immunopathogenesis of Sjögren's syndrome.

Female↗
PubMed1998

A metalloprotease-disintegrin, MDC9/meltrin-gamma/ADAM9 and PKCdelta are involved in TPA-induced ectodomain shedding of membrane-anchored heparin-binding EGF-like growth factor.

The ectodomains of many proteins located at the cell surface are shed upon cell stimulation. One such protein is the heparin-binding EGF-like growth factor (HB-EGF) that exists in a membrane-anchored form which is converted to a soluble form upon cell stimulation with TPA, an activator of protein kinase C (PKC). We show that PKCdelta binds in vivo and in vitro to the cytoplasmic domain of MDC9/meltrin-gamma/ADAM9, a member of the metalloprotease-disintegrin family. Furthermore, the presence of constitutively active PKCdelta or MDC9 results in the shedding of the ectodomain of proHB-EGF, whereas MDC9 mutants lacking the metalloprotease domain, as well as kinase-negative PKCdelta, suppress the TPA-induced shedding of the ectodomain. These results suggest that MDC9 and PKCdelta are involved in the stimulus-coupled shedding of the proHB-EGF ectodomain.

ADAM Proteins↗
PubMed1998

Co-expression of yeast amber suppressor tRNATyr and tyrosyl-tRNA synthetase in Escherichia coli: possibility to expand the genetic code.

An efficient system was developed for the co-expression of a yeast tRNATyr/tyrosyl-tRNA synthetase (TyrRS) pair in Escherichia coli. Analysis of suppression patterns using several sets of E. coli and lambda phage mutants indicated that the expressed yeast suppressor tRNATyr was aminoacylated only with tyrosine by its cognate yeast TyrRS and not by E. coli TyrRS or other aminoacyl-tRNA synthetases. This extra tRNA/TyrRS pair is expected to be a key bridgehead for developing an in vivo system for the site-directed incorporation of unnatural amino acids into proteins.

Bacteriophage lambda↗
PubMed1998

Application of a linear alkylbenzene sulfonate biosensor to river water monitoring.

A novel whole cell biosensor was constructed for the detection of anionic surfactants in aquatic environments. The analysis was rapid, convenient and did not require organic reagents. In this report, the application of this sensor to river water samples was investigated when applied to environmental samples; other organic substances present in river water may affect the measurement of linear alkylbenzene sulfonates. In order to deal with this problem, a correction system was developed using whole cells of Trichosporon cutaneum. This system was applied to in situ 24 h continuous monitoring in the Saka river.

Benzenesulfonates↗