173 research outputs found

    Reconstruction of ancestral brains: Exploring the evolutionary process of encephalization in amniotes

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    AbstractThere is huge divergence in the size and complexity of vertebrate brains. Notably, mammals and birds have bigger brains than other vertebrates, largely because these animal groups established larger dorsal telencephali. Fossil evidence suggests that this anatomical trait could have evolved independently. However, recent comparative developmental analyses demonstrate surprising commonalities in neuronal subtypes among species, although this interpretation is highly controversial. In this review, we introduce intriguing evidence regarding brain evolution collected from recent studies in paleontology and developmental biology, and we discuss possible evolutionary changes in the cortical developmental programs that led to the encephalization and structural complexity of amniote brains. New research concepts and approaches will shed light on the origin and evolutionary processes of amniote brains, particularly the mammalian cerebral cortex

    Absorption and Fluorescence Spectra of 10-Hydroxy-benzo [h] quinoline and 10-Methoxy-benzo [h] quinoline in various Solvents

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    Article信州大学工学部紀要 73: 39-48 (1993)departmental bulletin pape

    The effect of cyclic phosphatidic acid on the proliferation and differentiation of mouse cerebellar granule precursor cells during cerebellar development

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    AbstractThe proliferation and differentiation of cerebellar granule cell precursors (GCPs) are highly regulated spatiotemporally during development. We focused on cyclic phosphatidic acid (cPA) as a lipid mediator with a cyclic phosphate group as a regulatory factor of GCPs. While its structure is similar to that of lysophosphatidic acid (LPA), its function is very unique. cPA is known to be present in the cerebellum at high levels, but its function has not been fully elucidated. In this study, we examined the role of cPA on the proliferation and differentiation of GCPs. A cell cycle analysis of GCPs revealed that cPA reduced the number of phospho-histone H3 (Phh3)-positive cells and bromodeoxy uridine (BrdU)-incorporated cells and increased an index of the cell cycle exit. We next analyzed the effect of cPA on GCP differentiation using Tuj1 as a neuronal marker of final differentiation. The results show that cPA increased the number of Tuj1-positive cells. Further analysis of the proliferation of GCPs showed that cPA suppressed Sonic hedgehog (Shh)-dependent proliferation, but did not suppress insulin-like growth factor-1 (IGF-1)-dependent proliferation. P2Y5 (LPA6), an LPA receptor, is highly expressed in GCPs. The knockdown of P2Y5 suppressed the inhibitory effect of cPA on the proliferation of GCPs, suggesting that P2Y5 is a candidate receptor for cPA. Thus, cPA suppresses the Shh-dependent proliferation of GCPs and promotes the differentiation of GCPs through P2Y5. These results demonstrate that cPA plays a critical role in the development of GCPs

    Identification and expression of the lamprey Pax6 gene: evolutionary origin of the segmented brain of vertebrates

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    The Pax6 gene plays a developmental role in various metazoans as the master regulatory gene for eye patterning. Pax6 is also spatially regulated in particular regions of the neural tube. Because the amphioxus has no neuromeres, an understanding of Pax6 expression in the agnathans is crucial for an insight into the origin of neuromerism in the vertebrates. We have isolated a single cognate cDNA of the Pax6 gene, LjPax6, from a Lampetra japonica cDNA library and observed the pattern of its expression using in situ hybridization. Phylogenetic analysis revealed that LjPax6 occurs as an sister group of gnathostome Pax6. In lamprey embryos, LjPax6 is expressed in the eye, the nasohypophysial plate, the oral ectoderm and the brain. In the central nervous system, LjPax6 is expressed in clearly delineated domains in the hindbrain, midbrain and forebrain. We compared the pattern of LjPax6 expression with that of other brain-specific regulatory genes, including LjOtxA, LjPax2/5/8, LjDlx1/6, LjEmx and LjTTF1. Most of the gene expression domains showed conserved pattern, which reflects the situation in the gnathostomes, conforming partly to the neuromeric patterns proposed for the gnathostomes. We conclude that most of the segmented domains of the vertebrate brain were already established in the ancestor common to all vertebrates. Major evolutionary changes in the vertebrate brain may have involved local restriction of cell lineages, leading to the establishment of neuromeres.</p

    GRAVITATIONAL EFFECT ON GROWTH OF InX Ga1-XSb TERNARY BULK CRYSTALS

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    The effect of gravity on dissolution of GaSb in InSb melt and growth of InGaSb was experimentally investigated using GaSb(seed)/InSb/GaSb(feed) sandwich samples. Two parameters were considered: (1) the inclination angle of the sample for gravity as 0&deg;, 53&deg; and 90&deg;, (2) the sample diameter (D) as 9 mm and 5mm. When &theta; =0&deg;, the interface was almost flat whereas the interfaces were strongly distorted when &theta; = 53&deg; and 90&deg;. The undissolved GaSb(feed) remained for \theta = 0 &deg;. However, it dissolved completely for &theta; = 90&deg;, and partially for &theta; = 53&deg;. As the gravitational angle was increased, the growth length of uniform composition became long. The decrease of sample diameter reduced the dissolution area of GaSb. These facts indicated that the dissolution and growth processes were strongly influenced by gravity

    A case of small-cell esophageal cancer with chronic renal failure undergoing hemodialysis safely treated with cisplatin and etoposide

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    A 54-year-old male undergoing hemodialysis was admitted to our hospital because of difficulty in swallowing. Esophagography and esophageal endoscopy revealed an irregular ulcerated lesion in the cervical esophagus. It was diagnosed as a small-cell esophageal cancer from the biopsy sample. Computed tomography showed a tumor infiltrating the trachea and a few lymph node metastases in the cervix, upper mediastinum, and abdomen. The patient was started on chemotherapy with cisplatin (CDDP) and etoposide (VP-16), which had been reported to be effective for small-cell lung cancer. The patient was treated with CDDP (80 mg/m2) on day 1 and VP-16 (100 mg/m2) on days 1, 3, and 5, every 4 weeks. On the days of chemotherapy, hemodialysis was started as soon as possible after completion of administration of the agents. No severe side effects were observed. After 4 courses of therapy, the patient achieved a partial response

    Bifunctionality of Rh3+ Modifier on TiO2 and Working Mechanism of Rh3+/TiO2 Photocatalyst under Irradiation of Visible Light

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    A rhodium(III) ion (Rh3+)-modified TiO2 (Rh3+/TiO2) photocatalyst, prepared by a simple adsorption method and exhibiting high levels of photocatalytic activity in degradation of organic compounds, was investigated by using X-ray absorption fine structure (XAFS) measurements, (photo)electrochemical measurements, double-beam photoacoustic (DB-PA) spectroscopic measurements, and photoluminescence measurements. Based on the results, the features of the Rh3+ modifier and the working mechanism of the Rh3+/TiO2 photocatalyst are discussed. XAFS measurements revealed that the Rh3+ species were highly dispersed and almost atomically isolated on TiO2. The (photo)electrochemical measurements, DB-PA spectroscopic measurements, and photoluminescence showed a unique bifunction of the Rh3+ modifier as a promoter for O2 reductions and an electron injector to the conduction band of TiO2 for response to visible light. The reasons for the Rh3+/TiO2 photocatalyst exhibiting higher levels of photocatalytic activity than those of TiO2 photocatalysts modified with other metal ions are also discussed on the basis of obtained results

    Trabectedin arrests a doxorubicin-resistant PDGFRA-activated liposarcoma patient-derived orthotopic xenograft (PDOX) nude mouse model.

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    BACKGROUND:Pleomorphic liposarcoma (PLPS) is a rare, heterogeneous and an aggressive variant of liposarcoma. Therefore, individualized therapy is urgently needed. Our recent reports suggest that trabectedin (TRAB) is effective against several patient-derived orthotopic xenograft (PDOX) mouse models. Here, we compared the efficacy of first-line therapy, doxorubicin (DOX), and TRAB in a platelet-derived growth factor receptor-α (PDGFRA)-amplified PLPS. METHODS:We used a fresh sample of PLPS tumor derived from a 68-year-old male patient diagnosed with a recurrent PLPS. Subcutaneous implantation of tumor tissue was performed in a nude mouse. After three weeks of implantation, tumor tissues were isolated and cut into small pieces. To match the patient a PDGFRA-amplified PLPS PDOX was created in the biceps femoris of nude mice. Mice were randomized into three groups: Group 1 (G1), control (untreated); Group 2 (G2), DOX-treated; Group 3 (G3), TRAB-treated. Measurement was done twice a week for tumor width, length, and mouse body weight. RESULTS:The PLPS PDOX&nbsp;showed&nbsp;resistance towards DOX. However, TRAB could arrest the PLPS (p &lt; 0.05 compared&nbsp;to control; p &lt; 0.05 compared to DOX) without any significant changes in body-weight. CONCLUSIONS:The data presented here suggest that for the individual patient the PLPS PDOX model could specifically distinguish both effective and ineffective drugs. This is especially crucial for PLPS because effective&nbsp;first-line therapy is harder to establish if it is not individualized

    ツギ ノ ナンカイ ジシン ツナミ ライシュウジ ニオケル シコク エンガンイキ ノ ジンテキ ヒガイ ケイゲンカ ニ カンスル ケンキュウ

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    In the following Nankai Earthquake Tsunami, the characteristics of the tsunami height and its arrival time in the coastal area of the Seto Inland Sea was discussed. It found that their values could be estimated by the simple operation of Aida’s Ansei Nankai Earthquake Model(1981). Next, it proposed the evacuation model as the death toll increases as to be behind in the taking evacuation beginning time for the example of Usa , Kochi Prefecture . Moreover, based on this method, it measured the opening and shutting effect of the gates which was put to the embankment to exert on the death toll, and then it evaluated the effectivity of the protection against disasters
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