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Y Fujiyoshi

Publications and source records attributed to Y Fujiyoshi.

70 records · Page 4Linked to original sources
PubMed1987

Exstrophy of the cloacal membrane. A pathologic study of four cases.

Exstrophy of the cloaca is a rare congenital anomaly. The authors add the pathologic findings of four distinct cases reported in this article to those reported in the literature. In all cases, common anomalies were recognized. In addition, there were rare anomalies, such as single umbilical artery, vestige of the left superior vena cava, common mesenterium, calcification of the cerebellum, incomplete segmentation of the left lung, abnormal shape of the liver, and knock-knee. The embryology of this complex anomaly is difficult. It is considered that this anomalous condition results from breakdown and mesodermal invasion of the cloacal membrane.

Abnormalities, Multiple↗
PubMed1986

Electron microscopic study of 5S rRNA crystals from Thermus thermophilus HB8.

Several types of crystals were grown from 5S rRNA, which was purified from the highly thermophilic bacterium, Thermus thermophilus HB8. Crystal lattice parameters were determined by X-ray and electron diffraction. One type of crystal was suitable for electron microscopy after staining with uranyl acetate. Two projections derived from micrographs taken at different tilt angles were processed for image analysis. This result enabled us to deduce the arrangement of molecules within the crystal lattice.

Crystallization↗
PubMed1986

Cystic brain lesion in utero.

Two autopsy cases of cystic brain lesion in utero are reported. One of them was a donor infant of twin transfusion syndrome. The baby died immediately after birth and showed multicystic encephalomalacia in the distribution of the anterior cerebral artery. The second baby was a stillborn infant with thanatophoric dwarfism with associated chronic periventricular leukomalacia (PVL). It was suggested that the multicystic encephalomalacia and chronic PVL found in the first and second cases were caused by persistent circulatory disturbances in utero.

Cysts↗
PubMed1984

Various types of 5s rRNA crystals as studied by X-ray diffraction and electron microscopy.

Six different types of 5 S rRNA crystals were obtained using the specimen purified from highly thermophilic bacteria, Thermus thermophilus HB8. The best crystal available diffracts X-rays up to 13A Bragg spacing. One type of crystals was sufficiently thin to be subjected to electron microscopy. Optically filtered images of two different projections exhibit molecular regions distinctly from the medium. Preliminary investigation of packing of the molecules into the unit cell gives some implication of their overall shape.

Microscopy, Electron↗
PubMed1982

Cross-linking study on skeletal muscle actin: properties of suberimidate-treated actin.

Cross-linking experiments were performed on muscle skeletal actin, using imidoesters of various chain lengths. Chemical analyses on all products except one (derived from succinimidate) show evidence of the presence of intramolecular cross-links in the molecule. The detailed properties of suberimidate-treated actin (SA) are as follows: SA contains nearly 1 mol of intramolecular cross-link per mol of actin and less than 15% of intermolecularly cross-linked products. Even at a low salt concentration, SA is polymeric, exchanges slowly its bound nucleotide with free nucleotides in solution, and shows an F-actin-type CD spectrum. Electron micrographs of SA reveal that SA exists actually as fibrous polymers in solutions of low ionic strength, although the fibers seem to be less rigid than those at high salt concentration. The F-form of SA at a high salt concentration is indistinguishable from intact F-actin. SA can bind heavy meromyosin and activate the ATPase of heavy meromyosin as observed for intact F-actin. Tropomyosin binds SA only at a high salt concentration. These results show that SA possesses the properties of F-actin even in media of low salt concentration, which are favorable for depolymerization of F-actin. Thus, we may infer that the conformation of SA is frozen in the F-state of actin by the introduction of intramolecular cross-links in the protein.

Actins↗
PubMed1980

Digital reconstruction of bright field phase contrast images from high resolution electron micrographs.

The theory of bright-field image formation of thin specimens in a conventional transmission electron microscope is presented. The recorded image contrast is shown to be predominantly linear in the electron atom scattering amplitudes which are in general complex (possessing phase and amplitude). A linearized image model describing multiple images of varying defocus (defocus series) is derived. Image degradation is characterized by an instrumental transfer function (including spherical aberration, defocus and partial coherence), a finite signal-to-noise ratio and a Debye--Waller temperature factor. Using the minimum mean square error criterion, a new method of image reconstruction to recover the real and imaginary parts of the ideal phase contrast image from a defocus series is derived. This new method of image reconstruction reduces to the well known Wiener filter in the appropriate limiting conditions. A defocus series of micrographs taken on the Kyoto 500 keV electron microscope using a radiation damage resistant specimen of chlorinated copper phthalocyanine is processed. The signal-to-noise ratio of this series is found to be approximately 10. A resolution of approximately 2 A is apparent in the unprocessed images. The complex image reconstructed from this defocus series shows increased resolution in the real part of the image (approximately 1.4 A) and increased heavy/light atom contrast in the imaginary part of the image.

Computers↗
PubMedDate not supplied

A case of retroperitoneal malignant mesenchymoma.

A rare case is reported of malignant mesenchymoma of a retroperitoneal lesion involving the kidney and composed of leiomyosarcoma and liposarcoma. The tumor, measuring 13 x 12 x 11 cm and weighing 1910 g, arising from the soft tissue of the retroperitoneum or renal capsule, was completely removed surgically. Thirteen months after surgical operation, multiple metastasis was observed. Immunohistochemical and electron microscopical examination showed two different mesenchymal elements. Magnetic resonance imaging findings were compatible with the pathological findings. This case appears to be the second in the world literature.

Aged↗
PubMedDate not supplied

Cerebrospinal fluid cytology in immature teratoma of the central nervous system. A case report.

The present case shows the usefulness of cerebrospinal fluid (CSF) cytology in the diagnosis of leptomeningeal dissemination by immature teratoma. The tumor arose in the thoracolumbar spinal cord of a 14-year-old male. The initial histopathologic diagnosis was made on the tumor tissue taken at laminectomy. Postoperatively, CSF cytology revealed epithelial cell clusters, scattered squamous epithelial cells and small bundles of striated muscle fibers in the background of many histiocytes and inflammatory cells. Although these cells showed only slight cytologic atypia, their presence in the subarachnoid space suggested the leptomeningeal spread of well-differentiated portions of the immature teratoma. The postmortem examination revealed the primary tumor in the spinal cord and multiple metastatic nodules in the brain.

Adolescent↗
PubMedDate not supplied

Electron microscopy of tRNA crystals. I. Thin crystals negatively stained with uranyl acetate.

The first attempt to study crystal structures of tRNA by electron microscopy is described. Sufficiently thin crystals were prepared from yeast tRNAphe. The thickness of the thinnest was estimated at 130 A corresponding to a bilayer of the molecules. The L-shaped structure seemed to be maintained even after the negative staining with uranyl acetate. Optically filtered images from electron micrographs were compared with those simulated from the drawing of the molecular model by optical transform. The results suggest that the observed images reflect the real molecular arrangements within the crystal lattice although the shape of tRNA molecules seems to be somewhat modified by the uneven staining.

Crystallography↗