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Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 181 records · Page 10Linked to original sources

Adhesion of insect cells expressing the feline herpesvirus type 1 hemagglutinin (gD) to feline cell lines.

Feline herpesvirus type 1 (FHV-1) gD-expressing Sf9 cells adhered to two feline cell lines, but not to the porcine, bovine, or canine cell lines tested. In addition, this adhesion activity was inhibited by a monoclonal antibody against FHV-1 gD. These results showed that the FHV-1 gD might bind to a specific-molecule(s) on the surface of feline cell lines. We discussed a possible importance of the FHV-1 gD in host cell restriction to FHV-1 infection.

Alphaherpesvirinae↗

[High levels of serum ferritin in elderly patients with non-insulin-dependent diabetes mellitus].

We studied concentrations of serum ferritin, glycosylated ferritin, and non-glycosylated ferritin in elderly patients with diabetes. The subjects were 111 people who were at least 60 years old: 54 healthy controls, 14 diabetic patients without retinopathy, and 43 diabetic patients with retinopathy. The mean levels of ferritin, glycosylated ferritin, and non-glycosylated ferritin in serum were significantly higher in the patients with retinopathy than in healthy controls. The mean percent glycosylated ferritin did not differ between patients with retinopathy and healthy controls. The mean levels of serum ferritin, glycosylated ferritin, and non-glycosylated ferritin, and the percent glycosylated ferritin did not differ significantly between patients without retinopathy and health controls. None of these values differed between subjects with macroangiopathy and those without macroangiopathy, in both groups of patients. In patients with diabetes, none of the values measured was significantly related to fasting plasma glucose, HbA1c, or the duration of diabetes. These results suggest that diabetic microangiopathy is associated with abnormally high levels of ferritin in serum.

Aged↗

[Localization of epileptogenic foci and visualization of propagating process in the seizure discharges using crosscorrelation analysis].

Electrocorticogram (ECoG) of intractable focal epilepsy was analyzed using AR model, wavelet analysis and crosscorrelation analysis. The sequential 3-dimensional visualization technique of phase shift maps was developed to localize the epileptic foci and to study their propagation process. The crosscorrelation of the epileptic discharges was calculated between the electrodes in every unit of time, to get the phase shift. More than two epileptogenic foci were localized and two kinds of propagating process were shown. These findings suggest that two kinds of mechanism might work in development of epileptic discharges, and our newly developed visualization technique is useful to investigate the epileptogenesis etiology.

Brain Mapping↗

Apparent Dipole Moments of Aerosol OT Reversed Micelles in Cyclohexane Determined at a Frequency of 1 MHz and at a Temperature of 298.15 K

Precise determinations of dielectric constants were carried out for Aerosol OT reversed micelles in cyclohexane at a frequency of 1 MHz and at a temperature of 298.15 K for molalities of AOT from 0 to 0.04 mol kg-1. The ratio of the amount of water, r, to that of AOT was varied from 0 to 25 and the apparent dipole moments for the mixed solute (AOT + r·H2O) were calculated. Discontinuous change in the limiting dipole moment with increasing r was found and was related to the characteristic of water to bind to the head group of AOT. The process of forming W/O microemulsion and the molecular interactions in the micellar core are discussed in terms of the hydration of AOT.

Journal Article↗

Isolation of a cDNA encoding the X enopus homologue of mammalian Cdc25A that can induce meiotic maturation of oocytes.

From a cDNA library of Xenopus laevis (Xl) oocytes, we isolated a cDNA encoding a putative protein phosphatase homologous to mammalian Cdc25A. Sequence analysis predicts that the Xl cdc25A gene product (Xl Cdc25A) consists of 521 amino acid residues and shares overall 55% identity with human Cdc25A. When its mRNA is injected into Xl oocytes, Xl Cdc25A can act as a potent M phase inducer.

Amino Acid Sequence↗

Radiosensitivity of blood lymphocytes from basocellular carcinoma patients, as detected by the micronucleus assay.

Cytogenetic techniques, the micronucleus (MN) assay, in particular, have been widely used in population monitoring, biological dosimetry and early detection of groups susceptible to cancer. Individuals respond differently to several environmental agents. The efficiency of the cellular repair mechanisms would be responsible, at least to some extent, for individual differences in sensitivity to neoplasia. In order to determine the sensitivity of cancer patients to ionizing radiation, blood cultures from untreated individuals with basocellular carcinoma, young healthy subjects and older healthy subjects, were irradiated in vitro with 60Co at doses ranging from 0 to 500 cGy and submitted to the cyto-B micronucleus assay; the frequency of cells and distribution of MN and dose-response relationships were analyzed. Results showed that cancer patients had a lower frequency of cells with spontaneous MN than older healthy subjects. The frequency of micronucleated cells was not different in patients and healthy subjects, but not the distribution of MN per radiation dose: for the carcinoma group, while the proportion of cells with one MN decreases drastically, the proportion of the cells with two or more MN increases with the same intensity. Our results show that the proportion of damaged cells is similar in patients with basocellular carcinoma and healthy subjects, but the magnitude of radiation-induced lesion is greater in the cancer patients.

Adult↗

Neurocalcin immunoreactivity in the rat accessory olfactory bulb.

The distribution and morphology of neurocalcin-immunopositive neurons have been studied in the rat accessory olfactory bulb. Different subsets of neurons displaying neurocalcin immunoreactivity were found in the glomerular layer, the external plexiform layer and the internal plexiform layer. The most abundant staining was detected in the glomerular layer where neurocalcin-immunoreactive periglomerular cells and external tufted cells were observed in the lateral glomeruli, whereas the central region of this layer was practically devoid of immunopositive neurons. In the external plexiform layer, medial tufted cells and Van Gehuchten cells displayed neurocalcin immunoreactivity. In the internal plexiform layer, interneurons classified as horizontal cells and vertical cells of Cajal were neurocalcin-immunoreactivity. In the internal plexiform layer, interneurons classified as horizontal cells and vertical cells of Cajal were neurocalcin-immunostained. The staining pattern for neurocalcin in the accessory olfactory bulb showed similarities with the immunostaining described in this brain region for another EF-hand calcium binding protein, calbindin D-28k. However, after double immunohistochemical labeling, colocalization of both proteins in the same neuron was not observed, reflecting a biochemical heterogeneity within morphologically homogeneous neuronal groups.

Animals↗

Cystic Hypersecretory Duct Carcinoma of the Breast:A Case Reprot Describing the Cytologic Features.

We report the clinical, cytological and pathological features of so-called cystic hypersecretory duct carcinoma occurring in a 60-year-old Japanese woman. The tumor mainfested a multicystic mass ultrasonographically, and aspiration biopsy cytology revealed atypical ductal epithelial cells with vacuolar cytoplasm. A modified radical mastectomy was performed. Histologically, the lesion was charcterized by many dilated ducts containing eosinophilic secretions, which resembled thyroid colloid. The ducts were lined by an intraductal micropapillary carcinoma with hobnail-shaped cells, and were positive for lactalbumin immunohistochemically. Additionally, a so-called cystic hypersecretory hyperplasia was seen in the surrounding breast parenchyma. Although a direct transition from the hyperplasia to the carcinoma was not proved, a close relationship between the two lesions was suggested.

Journal Article↗

Stress signal, mediated by a Hog1-like MAP kinase, controls sexual development in fission yeast.

We identified the phh1+ gene that encodes a MAP kinase as the effector of Wis1 MAP kinase kinase in fission yeast, which is highly homologous with HOG1 of S. cerevisiae. Heterothalic phh1 dsiruptant is phenotypically indistinguishable from wis1 deletion mutant, both displaying the same extent of partial sterility and enhanced sensitivity to a variety of stress. In phh1 disruptant, nitrogen starvation-induced expression of ste11+, a key controller of sexual differentiation, is markedly diminished. Ectopic expression of ste11+ effectively restores fertility, but not stress resistance, to the phh1 disruptant. These data show that stress signal, mediated by a MAP kinase, is required for efficient start of sexual differentiation.

Amino Acid Sequence↗

Crystallization and preliminary X-ray crystallographic studies of recombinant bovine neurocalcin delta.

Neurocalcins are novel brain-specific proteins that belong to a new subclass of the EF-hand super-family of calcium binding proteins, defined by the photoreceptor cell-specific protein recoverin (Terasawa et al., J. Biol. Chem. 267:19596-19599, 1992). Here we report the purification and crystallization of unmyristoylated recombinant bovine neurocalcin delta from Escherichia coli. Crystals of a bovine neurocalcin delta have been grown by macro-seeding at room temperature through vapor phase equilibration using the hanging drop technique with ammonium sulfate as the precipitating agent. The crystals diffract to at least 2.5 A resolution and belong to monoclinic space group P21 with unit cell dimensions a = 42.734 A, b = 94.343 A, c = 50.696 A, and beta = 98.37 degrees. The asymmetric unit contains two molecules, with corresponding crystal volume per protein mass (Vm) of 2.29 A3/Da and solvent fraction of 45% by volume, exhibiting an approximate 222 point symmetry.

Animals↗

1H NMR assignments of apo calcyclin and comparative structural analysis with calbindin D9k and S100 beta.

The homodimeric S100 protein calcyclin has been studied in the apo state by two-dimensional 1H NMR spectroscopy. Using a combination of scalar correlation and NOE experiments, sequence-specific 1H NMR assignments were obtained for all but one backbone and > 90% of the side-chain resonances. To our knowledge, the 2 x 90 residue (20 kDa) calcyclin dimer is the largest protein system for which such complete assignments have been made by purely homonuclear methods. Sequential and medium-range NOEs and slowly exchanging backbone amide protons identified directly the four helices and the short antiparallel beta-type interaction between the two binding loops that comprise each subunit of the dimer. Further analysis of NOEs enabled the unambiguous assignment of 556 intrasubunit distance constraints, 24 intrasubunit hydrogen bonding constraints, and 2 x 26 intersubunit distance constraints. The conformation of the monomer subunit was refined by distance geometry and restrained molecular dynamics calculations using the intrasubunit constraints only. Calculation of the dimer structure starting from this conformational ensemble has been reported elsewhere. The extent of structural homology among the apo calcyclin subunit, the monomer subunit of apo S100 beta, and monomeric apo calbindin D9k has been examined in detail by comparing 1H NMR chemical shifts and secondary structures. This analysis was extended to a comprehensive comparison of the three-dimensional structures of the calcyclin monomer subunit and calbindin D9k, which revealed greater similarity in the packing of their hydrophobic cores than was anticipated previously. Together, these results support the hypothesis that all members of the S100 family have similar core structures and similar modes of dimerization. Analysis of the amphiphilicity of Helix IV is used to explain why calbindin D9k is monomeric, but full-length S100 proteins form homodimers.

Amino Acid Sequence↗

Use of a suture holder facilitates transanal anastomosis.

We report here that use of a suture holder facilitates transanal anastomosis in cases of total proctocolectomy or low rectal anastomosis. Feasible control of multiple interrupted suturing and unhampered visibility of the entire process are made possible with this approach.

Anal Canal↗

Expression and properties of feline herpesvirus type 1 gD (hemagglutinin) by a recombinant baculovirus.

We constructed a recombinant baculovirus expressing feline herpesvirus type I (FHV-1) gD in insect cells (Sf9 cells). The expressed product was identified as FHV-1 gD by a panel of monoclonal antibodies specific for the FHV-1 gD, and had an apparent molecular mass of approximately 49 kDa, which was less than that of the authentic FHV-1 gD. When the FHV-1 gD protein were expressed in Sf9 cells and CRFK cells in the presence of tunicamycin, the FHV-1 gD exhibited a molecular mass of 41 kDa. It was shown that the gD protein was transported to the surface of recombinant virus-infected Sf9 cells when examined by membrane-immunofluorescence analysis, and that the gD expressed on the surface of Sf9 cells adsorbed feline erythrocytes. Mice inoculated with a lysate of Sf9 cells expressing FHV-1 gD induced antibodies with virus-neutralizing and hemagglutination-inhibition activities. Therefore, the expressed gD appears to be biologically authentic. These data suggested that recombinant FHV-1 gD produced in Sf9 cells may be a useful immunogen as a feline vaccine.

Animals↗

Serum antibodies to carbonic anhydrase I and II in patients with idiopathic chronic pancreatitis and Sjögren's syndrome.

BACKGROUND & AIMS: Patients with idiopathic chronic pancreatitis and Sjögren's syndrome show immune responses against a 60-kilodalton protein isolated from human pancreas extracts. Monoclonal antibody SP3-1, raised against the 60-kilodalton protein, reacts with ductal cells in several exocrine organs and cross-reacts with human carbonic anhydrase II. The present study evaluated serum from patients with these diseases for antibodies to human carbonic anhydrase I and II. METHODS: An enzyme-linked immunosorbent assay was used to quantify serum antibody against carbonic anhydrase I and II. RESULTS: Serum antibodies against carbonic anhydrase I and II were detected in 7 and 11 of 33 patients with idiopathic chronic pancreatitis, respectively, and in 8 and 13 of 21 patients with Sjögren's syndrome, respectively. The positive prevalence rates of patients with antibodies of carbonic anhydrase II were significantly different among patients with idiopathic chronic pancreatitis and Sjögren's syndrome compared with normal patients (1 of 21). There were no significant differences in the prevalence rates of patients with alcoholic chronic pancreatitis (3 of 20), gallstone-related chronic pancreatitis (0 of 7), and primary biliary cirrhosis (1 of 11). CONCLUSIONS: The results suggest that carbonic anhydrase II is one candidate target antigen recognized during the autoimmune pathophysiology observed in idiopathic chronic pancreatitis and Sjögren's syndrome.

Antibody Specificity↗

A new cleft palate repair.

Cleft palate can be repaired by a palatal mucoperiosteal flap, but we have devised a new technique for cleft palate repair using a wide mucoperiosteal flap with an alveolar ridge mucosa and a cleft margin flap. This technique leaves the mucosa of the nasal cavity and vomer intact. The results include (1) good velopharyngeal competence and normal articulation, (2) few cases of fistula formation, and (3) minimal maxillary retardation.

Age Factors↗