90 research outputs found

    Proliferation Potentials of Human Intracranial Neoplasms Assessed with Ki-67 (MIB-1) Labeling Index and Argyrophilic Nucleolar Organizer Regions

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    To evaluate the accuracy of the Ki-67 labeling index (LI) as an index of brain tumor proliferation, specimens of 303 intracranial neoplasms were examined for tumor proliferation potentials as assessed by MIB-1 (Ki-67 antigen) immunostaining and/or counting the argyrophilic nucleolar organizer regions (Ag-NORs). The Ki-67 LIs were higher in the histologically high grade tumors, i.e., the metastatic carcinomas, malignant lymphomas, glioblastomas, medulloblastomas, anaplastic astrocytomas, anaplastic oligodendrogliomas, anaplastic ependymomas, and anaplastic meningiomas compared to the histologically low grade tumors, i.e., the pilocytic astrocytomas, grade II astrocytomas, oligodendrogliomas, ependymomas, meningiomas other than those of the anaplastic variety, and pituitary adenomas. The number of Ag-NORs was not correlated with the tumor grade, and was inconsistent with the growth potential in some tumors. Moreover, in the consecutive sections of 87 tumors stained for both Ki-67 and Ag-NORs, the number of Ag-NORs did not correlate with the tumor Ki-67 LI in a regression analysis (r = 0.139). The patients with a high grade astrocytoma (anaplastic astrocytoma and glioblastoma) and a tumor Ki-67 LI > 10 had significantly shorter survival periods than those of the patients with a Ki-67 LI < 10 (p = 0.029). Our results thus suggest that Ki-67 is a potential marker of tumor growth activity and that the Ki-67 LI may be of use as an indicator of the prognosis of patients with brain tumor. The number of Ag-NORs may not always reflect the growth potential of some tumors

    Tuberous Sclerosis Complex Associated with Papillary Serous Carcinoma of the Peritoneum, Lymphangioleiomyomatosis, and Angiomyolipoma

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    Tuberous sclerosis complex (TSC) is associated with benign and malignant tumors, including lymphangioleiomyomatosis (LAM) and angiomyolipoma (AML). We herein describe the TSC case of a 50-year-old woman having a papillary serous carcinoma of the peritoneum (PSCP), LAM, and AML. On microscopic examination, the PSCP cells showed a cuboidal to columnar shape, proliferated into the papillae, and infiltrated into the peritoneal cavity and anterior thoracic wall. On immunohistochemical evaluation, the tumor cells were positive for epithelial membrane antigen, human epidermal cytokeratins, and progesterone receptor, but negative for calretinin, carcinoembryonic antigen, MCF-7 cell line (Ber-EP4), and estrogen receptor

    High-field phase diagram of a chiral-lattice antiferromagnet Sr(TiO)Cu4(PO4)4

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    High-field phase diagram of a chiral-lattice antiferromagnet Sr(TiO)Cu4(PO4)4 is studied by means of the ultrasound, dielectric, and magnetocaloric-effect measurements. These experimental techniques reveal two new phase transitions at high fields, which have not been resolved by the previous magnetization experiments. Specifically, the c66 acoustic mode shows drastic changes with hysteresis with applied fields along the c axis, indicating a strong magneto-elastic coupling. Combined with the cluster mean-field theory, we discuss the origins of these phase transitions. By considering the chiral-twist effect of Cu4O12 cupola units, which is inherent to the chiral crystal structure, the phase diagram is reasonably reproduced. The agreement between the experiment and theory suggests that this material is a unique quasi two-dimensional spin system with competing exchange interactions and chirality, leading to the rich phase diagram.Comment: 12 pages, 11 figures, 1 tabl

    Identification of Nitrogen-Fixing Bradyrhizobium Associated With Roots of Field-Grown Sorghum by Metagenome and Proteome Analyses

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    Sorghum (Sorghum bicolor) is cultivated worldwide for food, bioethanol, and fodder production. Although nitrogen fixation in sorghum has been studied since the 1970s, N2-fixing bacteria have not been widely examined in field-grown sorghum plants because the identification of functional diazotrophs depends on the culture method used. The aim of this study was to identify functional N2-fixing bacteria associated with field-grown sorghum by using “omics” approaches. Four lines of sorghum (KM1, KM2, KM4, and KM5) were grown in a field in Fukushima, Japan. The nitrogen-fixing activities of the roots, leaves, and stems were evaluated by acetylene reduction and 15N2-feeding assays. The highest nitrogen-fixing activities were detected in the roots of lines KM1 and KM2 at the late growth stage. Bacterial cells extracted from KM1 and KM2 roots were analyzed by metagenome, proteome, and isolation approaches and their DNA was isolated and sequenced. Nitrogenase structural gene sequences in the metagenome sequences were retrieved using two nitrogenase databases. Most sequences were assigned to nifHDK of Bradyrhizobium species, including non-nodulating Bradyrhizobium sp. S23321 and photosynthetic B. oligotrophicum S58T. Amplicon sequence and metagenome analysis revealed a relatively higher abundance (2.9–3.6%) of Bradyrhizobium in the roots. Proteome analysis indicated that three NifHDK proteins of Bradyrhizobium species were consistently detected across sample replicates. By using oligotrophic media, we purified eight bradyrhizobial isolates. Among them, two bradyrhizobial isolates possessed 16S rRNA and nif genes similar to those in S23321 and S58T which were predicted as functional diazotrophs by omics approaches. Both free-living cells of the isolates expressed N2-fixing activity in a semi-solid medium according to an acetylene reduction assay. These results suggest that major functional N2-fixing bacteria in sorghum roots are unique bradyrhizobia that resemble photosynthetic B. oligotrophicum S58T and non-nodulating Bradyrhizobium sp. S23321. Based on our findings, we discuss the N2-fixing activity level of sorghum plants, phylogenetic and genomic comparison with diazotrophic bacteria in other crops, and Bradyrhizobium diversity in N2 fixation and nodulation

    Expression of aspartyl protease and C3HC4-type RING zinc finger genes are responsive to ascorbic acid in Arabidopsis thaliana

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    Ascorbate (AsA) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. The aim was to identify genes whose transcript levels respond to changes in leaf AsA. The AsA-deficient Arabidopsis mutant vtc2-1 was incubated with the AsA precursor L-galactono-1,4-lactone (L-GalL) to increase leaf AsA concentration. Differentially expressed genes screened by DNA microarray were further characterized for AsA responsiveness in wild-type plants. The analysis of 14 candidates by real-time PCR identified an aspartyl protease gene (ASP, At1g66180) and a C3HC4-type RING zinc finger gene (AtATL15, At1g22500) whose transcripts were rapidly responsive to increases in AsA pool size caused by L-GalL and AsA supplementation and light. Transgenic Arabidopsis plants expressing an AtATL15 promoter::luciferase reporter confirmed that the promoter is L-GalL, AsA, and light responsive. The expression patterns of ASP and AtATL15 suggest they have roles in growth regulation. The promoter of AtATL15 is responsive to AsA status and will provide a tool to investigate the functions of AsA in plants further

    Cellular immunity in children with successful immunoprophylactic treatment for mother-to-child transmission of hepatitis B virus

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    Background: The administration of hepatitis B immunoglobulin followed by hepatitis B vaccine can result in a protective efficacy of almost 90% in mother-to-child transmission of hepatitis B virus (HBV). However, little is known about immunity against HBV infection in children after immunoprophylactic treatment. We tried to assess the association between T-cell responses and viremia in children after successful prophylactic treatment. Methods: Thirteen children and their 8 HBV carrier mothers (8 families), who were positive for human leukocyte antigen (HLA)-A24, were enrolled in this study. All of the 13 children received immunoprophylactic treatment and became negative for hepatitis B surface antigen (HBsAg) after birth. HBV-specific cytotoxic T lymphocyte (CTL) responses were evaluated using IFNγ - enzyme-linked immunosorbent spot (ELISPOT) and major histocompatibility complex class I peptide pentamer assays. Serum HBV DNA was measured by real-time PCR. Results: Significant HBV-specific T-cell responses were detected in 2 (15%) of the 13 children by ELISPOT. However, the frequency of HLA-A24-HBV-specific CTLs was very low in both HBV carrier mothers and children using pentamers. Of the 13 children, 4 (31%) were positive for serum HBV DNA. However, the levels of serum HBV DNA were 100 copies/ml or less. One of the 2 children in whom significant HBV-specific CTL responses were detectable was positive for serum HBV DNA. Conclusions: HBV core and polymerase-specific T-cell responses were detected and a low-dose viremia was observed in children after successful immunoprophylaxis treatment. Although the presence of viremia was not related to HBV-specific T-cell responses, CTLs might play a role in the control of HBV infection in children born to HBsAg-positive mothers after immunoprophylactic treatment. </p
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