134 research outputs found

    Missense Mutation in the Alternative Splice Region of the PAX6 Gene in Eye Anomalies

    Get PDF
    SummaryThe PAX6 gene is involved in ocular morphogenesis, and PAX6 mutations have been detected in various types of ocular anomalies, including aniridia, Peters anomaly, corneal dystrophy, congenital cataract, and foveal hypoplasia. The gene encodes a transcriptional regulator that recognizes target genes through its paired-type DNA-binding domain. The paired domain is composed of two distinct DNA-binding subdomains, the N-terminal subdomain (NTS) and the C-terminal subdomain (CTS), which bind respective consensus DNA sequences. The human PAX6 gene produces two alternative splice isoforms that have the distinct structure of the paired domain. The insertion, into the NTS, of 14 additional amino acids encoded by exon 5a abolishes the DNA-binding activity of the NTS and unmasks the DNA-binding ability of the CTS. Thus, exon 5a appears to function as a molecular switch that specifies target genes. We ascertained a novel missense mutation in four pedigrees with Peters anomaly, congenital cataract, Axenfeldt anomaly, and/or foveal hypoplasia, which, to our knowledge, is the first mutation identified in the splice-variant region. A T→A transition at the 20th nucleotide position of exon 5a results in a Val→Asp (GTC→GAC) substitution at the 7th codon of the alternative splice region. Functional analyses demonstrated that the V54D mutation slightly increased NTS binding and decreased CTS transactivation activity to almost half

    Two-photon spectroscopy of core excitons in barium fluoride using synchrotron radiation and laser light

    Get PDF
    We have conducted two-photon spectroscopy of core excitons in BaF2. Synchrotron radiation and laser light were used for 5p core-electron excitation and Auger-free luminescence was detected as the signal. Two-photon excitation enables access to f and p orbitals that cannot be reached by one-photon excitation of electrons in p orbitals. It has been found that the spin-orbit splittings of 4f and 6p states of the Ba ion in BaF2 are 0.7 +/- 0.1 and 1.4 +/- 0.1 eV, respectively.</p

    Vascular Patterns of Villous Tumors of the Colorectum

    Get PDF
    In order to more fully understand the morphological characteristics of villous tumors of the colorectum, the vascular patterns of six colorectal resection specimens were microangiographically studied. Grossly, villous adenomas were of two main types: pedunculated polyps and carpet-like lesions. Pedunculated villous adenomas had many large stalk vessels in a broad short pedicle, representing a large blood supply to the tumor. The carpet-like lesions were composed of continuous clusters of polyps with stalk vessels and the flat elevated lesions among polyps and at the periphery showed similar vascular patterns to the mucosa of normal colon. In lesions with cancer invasive to the proper muscle layer, scattered ulcerations due to the destruction of polyps were also observed, corresponding to at least a Dukes B lesion. The above findings could represent very important additional information for endoscopic treatment or local excision for the prevention of hemorrhagic complicatios or incomplete removal of tumor

    Clinical Aspect of Peripheral Cholangiocarcinoma: A Study of 7 Hepatectomy Cases

    Get PDF
    To clarify the features and problems presented by a peripheral cholangiocarcinoma (CCC), seven patients with hepatectomy from the First Department of Surgery, Nagasaki University School of Medicine (6 patients), and from Department of Surgery, National Ureshino Hospital (one patient) were reviewed. Men predominate with ratio of 5:2, and an average age was 65.4 years. Tumor location was left lateral segment in 4 patients, right lobe, middle lobe and posterior segment in one, respectively. Three patients were associated with hepatolithiasis. Underlying liver disease was found in 4 patients (57%); cirrhosis in 3 patients, and chronic hepatitis in one. Initial symptoms were abdominal pain, fever and palpable abdominal mass. In imaging modalities available, the detection rates of tumor were 100% in CT and 67% in US and angiography, respectively. Combination of MRI and CT clearly showed tumor characteristics. The serum CEA was slightly elevated in 5 patients (83%), but serum CA19-9 rose strikingly in 3 patients. Most tumors showed an infiltrating growth along intrahepatic bile duct, with a portal vein thrombus and/or satellite tumors frequently. In 3 patients, early recurrence with intrahepatic metastasis occured within the first 6 months. The patient of poorly differentiated adenocarcinoma containing a squamous or signet ring cell carinoma showed an extremely poor prognosis. This study suggests that early detection of small CCC and an extended resection are the most important factors for the survival of patient

    An Experimental Evaluation of Tracheal Blood Flow with Special Referrence to Operative Procedure of Tracheal Mobilization

    Get PDF
    Based on the study with special referrence to blood flow in the trachea, the factors influential on the operative procedure of tracheal mobilization were carefully evaluated to ensure optimal surgical results. It has already been assumed with an aid of microangiographic technique that the main trancheal blood flow comprise two routes, namely, adventitial and submucosal layers. The amount of blood flow in the trachea divided into individual two layers were measured by hydrogen clearance test with wire electrodes placed in either adventitial or submucosal layer. When employed the procedure of extensive mobilization of the trachea, the level of tracheal blood flow reduced in adventitial layer rather lthan in submucosal layer. Blood flow in submucosal layer, however, remain closely near the normal level, which is thought to compensate a decreased blood supply in the tracheal adventitia. Meanwhile, when proposed an excessive tension of more than 800g at the site of anastomosis, a decrease in submucosal blood flow has become manifest despite of a slight decrease in adventitial blood flow simultaneously. Greater emphasis has been focused upo
    corecore