344 research outputs found

    On the flying squid stenotuthis oualaniensis (lessons) in Hawaiian waters

    Get PDF
    By the request of Honolulu Laboratory, Southwest Fisheries Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration (NOAA), the cooperative research of squid species in Hawaiian waters by Hokusei Maru Training ship of Hokkaido University was began from February, 1981, from two years. Furthermore University of Hawaii hopes for continuation of this research from November in 1983, and planned until 1987

    Interacting quantum rotors in oxygen-doped germanium

    Get PDF
    We investigate the interaction effect between oxygen impurities in crystalline germanium on the basis of a quantum rotor model. The dipolar interaction of nearby oxygen impurities engenders non-trivial low-lying excitations, giving rise to anomalous behaviors for oxygen-doped germanium (Ge:O) below a few degrees Kelvin. In particular, it is theoretically predicted that Ge:O samples with oxygen-concentration of 1017βˆ’18^{17-18}cmβˆ’3^{-3} show (i) power-law specific heats below 0.1 K, and (ii) a peculiar hump in dielectric susceptibilities around 1 K. We present an interpretation for the power-law specific heats, which is based on the picture of local double-well potentials randomly distributed in Ge:O samples.Comment: 13 pages, 11 figures; to be published in Phys. Rev.

    Multifractality of the quantum Hall wave functions in higher Landau levels

    Full text link
    To probe the universality class of the quantum Hall system at the metal-insulator critical point, the multifractality of the wave function ψ\psi is studied for higher Landau levels, N=1,2N=1,2, for various range (Οƒ)(\sigma ) of random potential. We have found that, while the multifractal spectrum f(Ξ±)f(\alpha) (and consequently the fractal dimension) does vary with NN, the parabolic form for f(Ξ±)f(\alpha) indicative of a log-normal distribution of ψ\psi persists in higher Landau levels. If we relate the multifractality with the scaling of localization via the conformal theory, an asymptotic recovery of the single-parameter scaling with increasing Οƒ\sigma is seen, in agreement with Huckestein's irrelevant scaling field argument.Comment: 10 pages, revtex, 5 figures available on request from [email protected]

    Dedifferentiated chondrosarcoma with leukocytosis and elevation of serum G-CSF. A case report

    Get PDF
    BACKGROUND: G-CSF is known to function as a hematopoietic growth factor and it is known to be responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies. CASE PRESENTATION: We report the case of a 72-year-old man with dedifferentiated chondrosarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma- or osteosarcoma-like features in addition to conventional chondrosarcoma, arising from his pelvic bone. After hemipelvectomy, when local recurrence and metastasis were identified, leukocytosis appeared and an elevated level of serum granulocyte-colony-stimulating factor (G-CSF) was also recognized. The patient died of multiple organ failure 2 months after surgery. Autopsy specimens showed that the histological specimens of the recurrence and metastasis were dedifferentiated components, without any conventional chondrosarcoma components. G-CSF was expressed only in the dedifferentiated components, not in the chondrosarcoma components, immunohistochemically. CONCLUSION: This is the first report of chondrosarcoma, or any other primary bone tumor, with leukocytosis, probably stimulated by tumor-produced G-CSF from the dedifferentiated components

    Intraneural synovial sarcoma of the median nerve

    Get PDF
    Synovial sarcomas are soft-tissue malignancies with a poor prognosis and propensity for distant metastases. Although originally believed to arise from the synovium, these tumors have been found to occur anywhere in the body. We report a rare case of synovial sarcoma arising from the median nerve. To our knowledge, this is the twelfth reported case of intraneural synovial sarcoma, and only the fourth arising from the median nerve. Because the diagnosis may not be apparent until after pathological examination of the surgical specimen, synovial sarcoma should be kept in mind when dealing with what may seem like a benign nerve tumor

    Mutation analysis of the Gadd45 gene at exon 4 in atypical fibroxanthoma

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Atypical fibroxanthoma (AFX) histologically mimics high-grade sarcoma in the skin, although it follows a benign clinical course. AFX occurs in the sun-exposed skin and for this reason, an association with ultraviolet light has long been suspected. Bax and Gadd45 are p53 effector proteins. Bax is a programmed cell death protein and belongs to the Bcl-2 family. Gadd45 is a multifunctional DNA damage-inducible gene associated with the process of DNA damage.</p> <p>Methods</p> <p>Immunohistochemical expression of Bax was analyzed in 7 cases of AFX, and in 7 cases of benign fibrous histiocytoma (BFH) used as a comparison. The expression pattern of Bax was compared to previously reported p53 and Gadd45 expressions in a correspondent series. Mutation of the Gadd45 gene at exon 4 was also analyzed in AFX.</p> <p>Results</p> <p>AFX and BFH showed immunoreactivities respectively for Bax (3/7, 0/7), Gadd45 (4/7, 1/7) and p53 (2/7, 0/7). There was no exact correlation between p53 expression and Bax or Gadd45 expression. However, the pattern of expression between Bax and Gadd45 was also the same, with the exception of one case. No mutation of the Gadd45 gene at exon 4 was observed in a series of 6 AFX cases where DNA was available (0/6).</p> <p>Conclusion</p> <p>These results suggest a possible association between Bax and Gadd45 in AFX, and may refute any possibility of dysfunction of Gadd45 in terms of gene mutation, at least at exon 4 of the Gadd45 gene.</p

    In Vitro Germ Cell Differentiation from Cynomolgus Monkey Embryonic Stem Cells

    Get PDF
    BACKGROUND: Mouse embryonic stem (ES) cells can differentiate into female and male germ cells in vitro. Primate ES cells can also differentiate into immature germ cells in vitro. However, little is known about the differentiation markers and culture conditions for in vitro germ cell differentiation from ES cells in primates. Monkey ES cells are thus considered to be a useful model to study primate gametogenesis in vitro. Therefore, in order to obtain further information on germ cell differentiation from primate ES cells, this study examined the ability of cynomolgus monkey ES cells to differentiate into germ cells in vitro. METHODS AND FINDINGS: To explore the differentiation markers for detecting germ cells differentiated from ES cells, the expression of various germ cell marker genes was examined in tissues and ES cells of the cynomolgus monkey (Macaca fascicularis). VASA is a valuable gene for the detection of germ cells differentiated from ES cells. An increase of VASA expression was observed when differentiation was induced in ES cells via embryoid body (EB) formation. In addition, the expression of other germ cell markers, such as NANOS and PIWIL1 genes, was also up-regulated as the EB differentiation progressed. Immunocytochemistry identified the cells expressing stage-specific embryonic antigen (SSEA) 1, OCT-4, and VASA proteins in the EBs. These cells were detected in the peripheral region of the EBs as specific cell populations, such as SSEA1-positive, OCT-4-positive cells, OCT-4-positive, VASA-positive cells, and OCT-4-negative, VASA-positive cells. Thereafter, the effect of mouse gonadal cell-conditioned medium and growth factors on germ cell differentiation from monkey ES cells was examined, and this revealed that the addition of BMP4 to differentiating ES cells increased the expression of SCP1, a meiotic marker gene. CONCLUSION: VASA is a valuable gene for the detection of germ cells differentiated from ES cells in monkeys, and the identification and characterization of germ cells derived from ES cells are possible by using reported germ cell markers in vivo, including SSEA1, OCT-4, and VASA, in vitro as well as in vivo. These findings are thus considered to help elucidate the germ cell developmental process in primates

    Increased Expression of Integrin-Linked Kinase Improves Cardiac Function and Decreases Mortality in Dilated Cardiomyopathy Model of Rats

    Get PDF
    AIMS: Integrin-linked kinase (ILK) is a multifunctional kinase linking the extracellular matrix to intracellular signaling pathways, whose activation in the heart gives rise to a number of functional consequences. The aim of this study is to demonstrate the therapeutic and survival benefit of cardiac ILK overexpression in a rat model of dilated cardiomyopathy. METHODS AND RESULTS: The dilated cardiomyopathy model was generated in rats by intraperitoneal administration of six equal doses of doxorubicin over a 2 week period. Five weeks after the first injection, echocardiographic analysis demonstrated impaired cardiac function and, at that point, recombinant adenoviral vector harboring ILK cDNA or vehicle was injected into the myocardium, and the rats re-studied 4 weeks later. Compared with vehicle injection, ILK treatment ameliorated inflammatory cell infiltration and cardiomyocyte degeneration, as well as left ventricular dilation and dysfunction. ILK treatment was also associated with a reduction in apoptosis and an increase in proliferation of cardiomyocytes, as well as decreased oxidative stress and autophagic vacuole accumulation. Importantly, mortality was lower in rats following ILK treatment than in those following vehicle injection. In cultured neonatal rat cardiomyocytes, we also found that ILK overexpression protected against doxorubicin-induced apoptosis, giving rise to an increase in their proliferation. CONCLUSIONS: These data demonstrate for the first time that ILK gene therapy improves cardiac function and survival in a model of dilated cardiomyopathy, and this may be mediated through suppression of inflammation, prevention of ventricular remodeling, inhibition of cardiomyocyte apoptosis and autophagy, and stimulation of cardiomyocyte proliferation
    • …
    corecore