Crossovers (COs) between homologous chromosomes ensure their faithful segregation during meiosis. We identify C. elegans COSA-1, a cyclin-related protein conserved in metazoa, as a key component required to convert meiotic double-strand breaks (DSBs) into COs.
View Article and Find Full Text PDFIn preparation for meiotic chromosome segregation, homologous chromosomes need to pair, synapse (i.e., assemble the synaptonemal complex, SC), and then recombine to generate a physical linkage (i.
View Article and Find Full Text PDFWe investigated the effects of the oral administration of lophenol (Lo) and cycloartanol (Cy), two kinds of antidiabetic phytosterol isolated from Aloe vera , on glucose and lipid metabolism in Zucker diabetic fatty (ZDF) rats. We demonstrated that the administrations of Lo and Cy suppressed random and fasting glucose levels and reduced visceral fat weights significantly. It was also observed that treatments with Lo and Cy decreased serum and hepatic lipid concentrations (triglyceride, nonesterified fatty acid, and total cholesterol).
View Article and Find Full Text PDFAnticancer Agents Med Chem
September 2012
Matrix metalloproteinases (MMPs) are known to participate in cancer invasion and metastasis. Copious research on MMPs and their inhibitors has promoted the understanding of the mechanisms of cancer invasion and metastasis as well as the development of effective drugs for cancer treatment. This review discusses the classification of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in relation to tumor growth and invasion mechanisms via signal transduction, followed by the possibilities for cancer treatment.
View Article and Find Full Text PDFHomologous chromosome pairing is a prerequisite to establish physical linkage between homologs, which is critical for faithful chromosome segregation during meiosis I. The establishment of pairing is genetically separable from subsequent synapsis, defined as stabilization of pairing by the synaptonemal complex (SC). The underlying mechanism of presynaptic pairing is poorly understood.
View Article and Find Full Text PDFObjective: To develope a new procedure for laparoscopic exogastric resection using a so-called "fundic rotation technique (FRT)" for gastric submucosal tumors (SMTs) on the posterior wall near the esophagogastric junction (EGJ).
Methods: Between April 2006 and February 2010, we performed laparoscopic resection for SMTs located near the EGJ (within 3.0 cm from the EGJ) in ten consecutive patients.
Objective: The aim of this study was to clarify the influence of histological changes in the gastric remnant on Helicobacter pylori (H. pylori) infection after distal gastrectomy (DG) and proximal gastrectomy (PG).
Methods: In total, 101 patients who underwent DG (n = 76) or PG (n = 25) for gastric cancer were included in the study.
Non-retroperitoneal dedifferentiated liposarcoma (DDLS) is relatively uncommon and its characterization at the molecular genetic level has been limited. We describe the cyto-genetic and molecular cytogenetic findings of giant DDLS arising in the right thigh of an 83-year-old woman. Magnetic resonance imaging revealed a mass composed of two components with heterogeneous signal intensities, suggesting the coexistence of a fatty area and another soft tissue component.
View Article and Find Full Text PDFA 74-year-old woman presented with central nervous system (CNS) lymphomatoid granulomatosis (LYG) that spontaneously regressed and then regrew shortly thereafter. Initial magnetic resonance imaging studies showed a well demarcated, round, enhanced lesion with perifocal edema in the left temporal lobe. The enhanced lesion and perifocal edema had drastically regressed without treatment at follow-up examination.
View Article and Find Full Text PDFDNA injected into the Caenorhabditis elegans germline forms extrachromosomal arrays that segregate during cell division [1, 2]. The mechanisms underlying array formation and segregation are not known. Here, we show that extrachromosomal arrays form de novo centromeres at high frequency, providing unique access to a process that occurs with extremely low frequency in other systems [3-8].
View Article and Find Full Text PDFWe present a case of choroid plexus papilloma with unusual histopathological findings. A 41-year-old Japanese man presented with dizziness. Brain magnetic resonance imaging scan showed a distinct mass in the fourth ventricle.
View Article and Find Full Text PDFBackground/aims: The morphological distribution of tumor cells in metastatic lymph nodes has been investigated in positive sentinel lymph nodes in several solid cancers. The aim of this study was to clarify the effect of the distribution of metastatic foci in lymph nodes on the prognosis in gastric cancer.
Methods: The distribution of metastatic foci in the 100 node-positive patients who had undergone curative gastrectomy were classified into two groups: (1) massive type, in which the tumor occupied the entire lymph node, and (2) non-massive type, in which the tumor did not occupy the entire lymph node.
During early meiotic prophase, a nucleus-wide reorganization leads to sorting of chromosomes into homologous pairs and to establishing associations between homologous chromosomes along their entire lengths. Here, we investigate global features of chromosome organization during this process, using a chromosome painting method in whole-mount Caenorhabditis elegans gonads that enables visualization of whole chromosomes along their entire lengths in the context of preserved 3D nuclear architecture. First, we show that neither spatial proximity of premeiotic chromosome territories nor chromosome-specific timing is a major factor driving homolog pairing.
View Article and Find Full Text PDFBackground: Laminin-5 (Ln5), a heterotrimer composed of three chains (α3, β3, and γ2), is a major component of the basement membrane in most adult tissues. One of the chains, Ln5-γ2, is a marker of invasive tumours because it is frequently expressed as a monomer in malignant tumours. Recent studies from our laboratories detected higher levels of Ln5-γ2 expression in basal cell carcinoma (BCC) than in trichoblastoma.
View Article and Find Full Text PDFBackground: Emmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Its first Ig domain (ECI) contains the biologically active site. The dependence of emmprin activity on N-glycosylation is controversial.
View Article and Find Full Text PDFMethods Mol Biol
September 2011
Successful meiotic recombination is driven by a series of programmed chromosome dynamics that include changes in the protein composition of meiotic chromosomes and the juxtaposition of homologous chromosomes. The simultaneous visualization of both chromosome-bound proteins and the status of homologous association is an important experimental approach to analyze the mechanisms supporting proper meiotic chromosome association. One of a number of model organisms used for meiosis research, the nematode Caenorhabditis elegans offers an excellent environment to study meiotic chromosome dynamics.
View Article and Find Full Text PDFStromal cells are the main source of matrix metalloproteinases (MMPs) in human carcinoma tissues. Emmprin is a glycosylated transmembrane protein containing two immunoglobulin (Ig) domains that is expressed in carcinoma cells and stimulates MMP production by adjacent stromal cells. The first Ig domain (ECI) of emmprin contains the biologically active site.
View Article and Find Full Text PDFNeurol Med Chir (Tokyo)
August 2011
A 23-year-old man was admitted with a rare case of radiation-induced astrocytoma manifesting as 3-month history of unstable gait. He had received 50 Gy of irradiation therapy for a germ cell tumor in the right basal ganglia 13 years earlier. Magnetic resonance (MR) imaging on admission showed a non-enhanced mass lesion in the right cerebellar hemisphere with expansion to the vermis.
View Article and Find Full Text PDFAlterations of the genes encoding α1 and α2 subunits of voltage-gated sodium channels (SCN1A, SCN2A) have been reported as causes of various types of epilepsy, most of which occur during the first year of life; as yet, however, the detailed mechanisms are unclear. We suppose that developmental changes of SCN1A and SCN2A in the human brain, which are unknown yet, may play an important role. So here, we studied the developmental changes of their corresponding proteins (Na(v)1.
View Article and Find Full Text PDFHeteromorphic sex chromosomes, such as the X/Y pair in mammals, differ in size and DNA sequence yet function as homologs during meiosis; this bivalent asymmetry presents special challenges for meiotic completion. In Caenorhabditis elegans males carrying mnT12, an X;IV fusion chromosome, mnT12 and IV form an asymmetric bivalent: chromosome IV sequences are capable of pairing and synapsis, while the contiguous X portion of mnT12 lacks a homologous pairing partner. Here, we investigate the meiotic behavior of this asymmetric neo-X/Y chromosome pair in C.
View Article and Find Full Text PDFMyxoid soft-tissue sarcomas represent a heterogeneous group of mesenchymal tumors characterized by a predominantly myxoid matrix, including myxoid liposarcoma (MLS), low-grade fibromyxoid sarcoma (LGFMS), extraskeletal myxoid chondrosarcoma (EMC), myxofibrosarcoma, myxoinflammatory fibroblastic sarcoma (MIFS), and myxoid dermatofibrosarcoma protuberans (DFSP). Cytogenetic and molecular genetic analyses have shown that many of these sarcomas are characterized by recurrent chromosomal translocations resulting in highly specific fusion genes (e.g.
View Article and Find Full Text PDFAggressive removal of circulating free light chains (FLC) by blood purification accompanied by chemotherapy is a promising approach for the treatment of acute renal failure due to myeloma cast nephropathy. Plasma exchange has been performed to remove serum FLC; in order to examine an alternative strategy we performed hemodiafiltration using protein-leaking dialyzers for the treatment of dialysis-dependent acute renal failure due to myeloma cast nephropathy. In the first case with κ-light chain cast nephropathy, the pre-treatment serum creatinine was 9.
View Article and Find Full Text PDFIn 2007 a young Japanese female was reported to suffer from a congenital brain malformation with a non-functioning pancreatic endocrine tumor arising from intracranial ectopic pancreatic tissue. Ectopic pancreas is normally confined to other endodermally-derived organs and not previously reported to be found in the brain. Therefore, we sought to better understand the true pancreatic nature of the tissue and to further understand the mechanism by which ectopic pancreas could appear in the brain.
View Article and Find Full Text PDFBackground: Pleomorphic malignant fibrous histiocytoma (MFH) is one of the most frequent malignant soft tissue tumors in adults. Despite the considerable amount of research on MFH cell lines, their characterization at a molecular cytogenetic level has not been extensively analyzed.
Methods And Results: We established a new permanent human cell line, FU-MFH-2, from a metastatic pleomorphic MFH of a 72-year-old Japanese man, and applied multicolor fluorescence in situ hybridization (M-FISH), Urovysion™ FISH, and comparative genomic hybridization (CGH) for the characterization of chromosomal aberrations.