161 research outputs found

    Preoperative factors predictive of postoperative decimal visual acuity ≥ 1.0 following surgical treatment for idiopathic epiretinal membrane

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    Hiroshi Kunikata1, Toshiaki Abe2, Jiro Kinukawa1, Kohji Nishida1,31Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan; 2Division of Clinical Cell Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan; 3Department of Ophthalmology, Osaka University Medical School, Suita, JapanPurpose: To report the preoperative best-corrected visual acuity (BCVA) and foveal thickness (FT) values that lead to a postoperative decimal BCVA of ≥ 1.0 after surgical removal of an idiopathic epiretinal membrane (ERM).Methods: This is a retrospective case series of 73 eyes that underwent surgery for removal of an idiopathic ERM. All eyes had been treated by a single surgeon using a 25-gauge transconjunctival sutureless vitrectomy and indocyanine green-assisted internal limiting membrane peel. The BCVA and FT were measured at baseline and 6 months postoperatively.Results: A postoperative decimal BCVA ≥ 1.0 was obtained in eyes with a preoperative decimal BCVA ≥ 0.3 but not in those with a preoperative decimal BCVA ≤ 0.2. The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly (P = 0.002) higher in eyes with a preoperative decimal BCVA ≥ 0.5 (50%) than in eyes with a preoperative decimal BCVA < 0.5 (11%). Additionally, a postoperative decimal BCVA of ≥ 1.0 was obtained in 51% of the eyes that had a preoperative FT < 400 µm, compared with only 21% of eyes with a preoperative FT ≥ 400 µm (P = 0.01). The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly higher in eyes with preoperative decimal BCVA ≥ 0.5 and FT < 400 µm (60%) than in eyes with preoperative decimal BCVA ≥ 0.5 and FT ≥ 400 µm (20%; P = 0.03 ) or preoperative BCVA < 0.5 and FT ≥ 400 µm (7%; P < 0.001).Conclusions: These findings indicate that eyes with both preoperative BCVA ≥ 0.5 and FT < 400 µm have a significantly better chance of obtaining a postoperative decimal BCVA ≥ 1.0 following idiopathic ERM removal.Keywords: 25-gauge vitrectomy, optical coherence tomography, epimacular membrane, epiretinal membrane, visual acuity, foveal thicknes

    Dynamin 2 Cooperates with Amphiphysin 1 in Phagocytosis in Sertoli Cells

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    Testicular Sertoli cells highly express dynamin 2 and amphiphysin 1. Here we demonstrate that dynamin 2 is implicated in phosphatidylserine (PS)-dependent phagocytosis in Sertoli cells. Immunofluorescence and dual-live imaging revealed that dynamin 2 and amphiphysin 1 accumulate simultaneously at ruffles. These proteins are specifically bound in vitro. Over-expression of dominant negative dynamin 2 (K44A) inhibits liposome-uptake and leads to the mis-localization of amphiphysin 1. Thus, the cooperative function of dynamin 2 and amphiphysin 1 in PS-dependent phagocytosis is strongly suggested.</p

    Considerations to Damage Patterns in the Marina District During the Loma Prieta Earthquake Based on Rayleigh Wave Investigation

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    Rayleigh wave investigation is made in the Marina District to study geotechnical factors controlling the damage patterns in the Loma Prieta earthquake. A portable system has been developed for determining a Rayleigh wave dispersion curve based on the measurements of artificially induced ground vibration or microtremor. Five sites are selected along a line crossing the hydraulic fill zone in which structures and/or buried utilities were significantly damaged. An inverse analysis on the measured dispersion curves results in a cross section of shear wave velocity profiles in the District. Site amplification and liquefaction potential of each site are estimated and discussed based on the Vs-profiles. It is shown that soil liquefaction is likely to have occurred throughout the fill zone, and that the predominant period of ground motions in the zone of structural damage is longer than and closer to the natural period of structures with soft first story than that in the non-damaged zone. These results appear to be consistent with the damage patterns in the District, indicating that the proposed investigation is effective for seismic zonation

    Raman spectroscopic studies on the ferroelectric soft mode in SnxSr1-xTiO3

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    The Raman spectra of novel ferroelectric ceramics SnxSr1-xTiO3 (x = 0.1, 0.05 and 0.02) were obtained to clarify the mechanism of their ferroelectric phase transitions. Two transverse-optic modes in the ferroelectric phase showed softening toward the ferroelectric transition temperature. A comparison of the spectra obtained for SnxSr1-xTiO3 with the spectrum of PbxSr1-xTiO3 facilitated the assignment of the observed modes under the assumption of the ferroelectric phase in C4v1 symmetry. However, several peaks violating the Raman selection rules were observed, suggesting the emergence and growth of polar regions even in the paraelectric phase

    Preliminary Report on the Geotechnical Aspects of the Philippine Earthquake of July 16, 1990

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    The Philippine earthquake of July 16, 1990 (MS = 7.8), of which epicenter is about 100 km north of Manila city, was one of the most costly single natural disasters in Philippine history. The loss of life of over 1,600 persons resulted. Extensive damage to buildings, roads, embankments, natural slopes, and bridges was observed in a widespread area of approximately 20,000 square kilometers. One of the major causes of the damage was liquefaction of various sandy soils including artificially fills, alluvial deposits of river delta, and sandbars. This paper presents a preliminary overview of damage aspects of the earthquake, with emphasis on liquefaction-induced damage of various structures

    Recruitment of Irgb6 to the membrane is a direct trigger for membrane deformation

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    Irgb6 is a member of interferon gamma-induced immunity related GTPase (IRG), and one of twenty "effector" IRGs, which coordinately attack parasitophorous vacuole membrane (PVM), causing death of intracellular pathogen. Although Irgb6 plays a pivotal role as a pioneer in the process of PVM disruption, the direct effect of Irgb6 on membrane remained to be elucidated. Here, we utilized artificial lipid membranes to reconstitute Irgb6-membrane interaction in vitro, and revealed that Irgb6 directly deformed the membranes. Liposomes incubated with recombinant Irgb6 were drastically deformed generating massive tubular protrusions in the absence of guanine nucleotide, or with GMP-PNP. Liposome deformation was abolished by incubating with Irgb6-K275A/R371A, point mutations at membrane targeting residues. The membrane tubules generated by Irgb6 were mostly disappeared by the addition of GTP or GDP, which are caused by detachment of Irgb6 from membrane. Binding of Irgb6 to the membrane, which was reconstituted in vitro using lipid monolayer, was stimulated at GTP-bound state. Irgb6 GTPase activity was stimulated by the presence of liposomes more than eightfold. Irgb6 GTPase activity in the absence of membrane was also slightly stimulated, by lowering ionic strength, or by increasing protein concentration, indicating synergistic stimulation of the GTPase activity. These results suggest that membrane targeting of Irgb6 and resulting membrane deformation does not require GTP, but converting into GTP-bound state is crucial for detaching Irgb6 from the membrane, which might coincident with local membrane disruption

    SlIAA9 Controls Tomato Elongation

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    Tomato INDOLE-3-ACETIC ACID9 (SlIAA9) is a transcriptional repressor in auxin signal transduction, and SlIAA9 knockout tomato plants develop parthenocarpic fruits without fertilization. We generated sliaa9 mutants with parthenocarpy in several commercial tomato cultivars (Moneymaker, Rio Grande, and Ailsa Craig) using CRISPR-Cas9, and null-segregant lines in the T1 generation were isolated by self-pollination, which was confirmed by PCR and Southern blot analysis. We then estimated shoot growth phenotypes of the mutant plants under different light (low and normal) conditions. The shoot length of sliaa9 plants in Moneymaker and Rio Grande was smaller than those of wild-type cultivars in low light conditions, whereas there was not clear difference between the mutant of Ailsa Craig and the wild-type under both light conditions. Furthermore, young seedlings in Rio Grande exhibited shade avoidance response in hypocotyl growth, in which the hypocotyl lengths were increased in low light conditions, and sliaa9 mutant seedlings of Ailsa Craig exhibited enhanced responses in this phenotype. Fruit production and growth rates were similar among the sliaa9 mutant tomato cultivars. These results suggest that control mechanisms involved in the interaction of AUX/IAA9 and lights condition in elongation growth differ among commercial tomato cultivars

    Actin bundling by dynamin 2 and cortactin is implicated in cell migration by stabilizing filopodia in human non-small cell lung carcinoma cells

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    The endocytic protein dynamin participates in the formation of actin-based membrane protrusions such as podosomes, pseudopodia, and invadopodia, which facilitate cancer cell migration, invasion, and metastasis. However, the role of dynamin in the formation of actin-based membrane protrusions at the leading edge of cancer cells is unclear. In this study, we demonstrate that the ubiquitously expressed dynamin 2 isoform facilitates cell migration by stabilizing F-actin bundles in filopodia of the lung cancer cell line H1299. Pharmacological inhibition of dynamin 2 decreased cell migration and filopodial formation. Furthermore, dynamin 2 and cortactin mostly colocalized along F-actin bundles in filopodia of serum-stimulated H1299 cells by immunofluorescent and immunoelectron microscopy. Knockdown of dynamin 2 or cortactin inhibited the formation of filopodia in serum-stimulated H1299 cells, concomitant with a loss of F-actin bundles. Expression of wild-type cortactin rescued the punctate-like localization of dynamin 2 and filopodial formation. The incubation of dynamin 2 and cortactin with F-actin induced the formation of long and thick actin bundles, with these proteins colocalizing at F-actin bundles. A depolymerization assay revealed that dynamin 2 and cortactin increased the stability of F-actin bundles. These results indicate that dynamin 2 and cortactin participate in cell migration by stabilizing F-actin bundles in filopodia. Taken together, these findings suggest that dynamin might be a possible molecular target for anticancer therapy

    Formation of meso, N-diphenylprotoporphyrin IX by an aerobic reaction of phenylhydrazine with oxyhemoglobins.

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    Administration of phenylhydrazine to rabbits resulted in the denaturation of hemoglobins in erythrocytes, causing the formation of intracellular precipitates known as Heinz bodies, severe hemolytic anemia, and reticulocytosis. To elucidate the molecular mechanism of the destabilization, we allowed human oxyhemoglobins to react aerobically with phenylhydrazine. After treatment with acetic acid/HCl and H2SO4/methanol, the chloroform extract contained blue-green pigments of major products accompanied by different minor products. Each product was isolated by column chromatography. By fast-atom-bombardment mass spectrometry (FAB-MS) and proton nuclear magnetic resonance (1H-NMR) spectrometry, dimethyl esters of N-phenylprotoporphyrin IX and meso, N-diphenylprotoporphyrin IX were determined. Other major products also were determined to be dimethyl esters of triphenyl-and tetraphenyl-substituted protoporphyrins by FAB-MS. The formation of meso, N-diphenylprotoporphyrin indicated that the addition of a phenyl radical to the meso-carbon atom of the protoporphyrin ring occurred. Triphenyl and tetraphenyl adducts also indicated the formation of phenyl radicals in the aerobic reaction of phenylhydrazine with oxyhemoglobins. From these results, we suggest that the formation of phenyl radicals and the replacement of heme with phenyl-substituted protoporphyrins cause the destabilization of hemoglobins to induce Heinz bodies and hemolytic anemia with phenylhydrazine.</p

    Oligomerization of Hepatitis C Virus Core Protein is Crucial for Interaction with the Cytoplasmic Domain of E1 Envelope Protein

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    Hepatitis C virus (HCV) contains two membrane-associated envelope glycoproteins, E1 and E2, which assemble as a heterodimer in the endoplasmic reticulum (ER). In this study, predictive algorithms and genetic analyses of deletion mutants and glycosylation site variants of the E1 glycoprotein were used to suggest that the glycoprotein can adopt two topologies in the ER membrane: the conventional type I membrane topology and a polytopic topology in which the protein spans the ER membrane twice with an intervening cytoplasmic loop (amino acid residues 288 to 360). We also demonstrate that the E1 glycoprotein is able to associate with the HCV core protein, but only upon oligomerization of the core protein in the presence of tRNA to form capsid-like structures. Yeast two-hybrid and immunoprecipitation analyses reveal that oligomerization of the core protein is promoted by amino acid residues 72 to 91 in the core. Furthermore, the association between the E1 glycoprotein and the assembled core can be recapitulated using a fusion protein containing the putative cytoplasmic loop of the E1 glycoprotein. This fusion protein is also able to compete with the intact E1 glycoprotein for binding to the core. Mutagenesis of the cytoplasmic loop of E1 was used to define a region of four amino acids (residues 312 to 315) that is important for interaction with the assembled HCV core. Taken together, our studies suggest that interaction between the self-oligomerized HCV core and the E1 glycoprotein is mediated through the cytoplasmic loop present in a polytopic form of the E1 glycoprotein
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