Publications by authors named "Manami Kobayashi"

Plant alkaloids are used in a variety of medicines, such as anti-cancer drugs and analgesics. Among these plant alkaloids, galanthamine is an Amaryllidaceae type alkaloid with acetylcholinesterase inhibition activity used in the treatment of neurological diseases such as Alzheimer's disease. Although the chemical synthesis of galanthamine has been successfully achieved, is the main source of its production.

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The LitR/CarH family comprises adenosyl B-based photosensory transcriptional regulators that control light-inducible carotenoid production in nonphototrophic bacteria. In this study, we established a blue-green light-inducible hyperexpression system using LitR and its partner ECF-type sigma factor LitS in streptomycin-producing Streptomyces griseus NBRC 13350. The constructed multiple-copy number plasmid, pLit19, carried five genetic elements: pIJ101rep, the thiostrepton resistance gene, litR, litS, and σ-recognized light-inducible crtE promoter.

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Maternally-loaded factors in the egg accumulate during oogenesis and are essential for the acquisition of oocyte and egg developmental competence to ensure the production of viable embryos. However, their molecular nature and functional importance remain poorly understood. Here, we present a collection of 9 recessive maternal-effect mutants identified in a zebrafish forward genetic screen that reveal unique molecular insights into the mechanisms controlling the vertebrate oocyte-to-embryo transition.

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Ciguatera poisoning (CP) is the most common type of marine biotoxin food poisoning worldwide, and it is caused by ciguatoxins (CTXs), thermostable polyether toxins produced by dinoflagellate and spp. It is typically caused by the consumption of large fish high on the food chain that have accumulated CTXs in their flesh. CTXs in trace amounts are found in natural samples, and they mainly induce neurotoxic effects in consumers at concentrations as low as 0.

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The Balbiani body (Bb) is the first marker of polarity in vertebrate oocytes. The Bb is a conserved structure found in diverse animals including insects, fish, amphibians, and mammals. During early zebrafish oogenesis, the Bb assembles as a transient aggregate of mRNA, proteins, and membrane-bound organelles at the presumptive vegetal side of the oocyte.

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We investigated similar compounds to ebselen and tideglusib, which exhibit strong activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), using Molecular ACCess System (MACCS) keys. Four candidate compounds were identified. One of them, phenyl-benzothiazol-3-one, showed coronavirus-specific 3C-like (3CL) protease inhibitory activity.

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Maternal factors which accumulate and establish oocyte polarity during the early stages of oogenesis play key roles in embryonic development, as well as germ cell formation. However, vertebrate oogenesis, especially early stages of oogenesis, is not well understood due to the difficulty of accessing these oocytes and the lack of analytical methods. Here, we report on a microinjection method for analyzing zebrafish early-stage oocytes and some artifacts to be aware of when performing oocyte injections or analyzing oocytes.

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Tea, and particularly bottled tea, is widely consumed worldwide and is often encountered at crime scenes in poisoning cases or used in place of urine in drug abuse monitoring. Tea is a rich source of polyphenols, such as catechins and theaflavins, and these compounds are useful for identification of trace quantities of tea samples. However, information on the contents of catechins and theaflavins in bottled tea is limited.

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Red alga dulse contains xylan with β(1→3)/β(1→4) linkages. We previously prepared xylooligosaccharides (XOSs) from dulse xylan; however, the product contained many D-xylose residues and fewer XOSs with β(1→3) linkages. To improve the efficiency of XOS production, we prepared two recombinant endoxylanases from Streptomyces thermogriseus (StXyl10 and StXyl11).

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Axis specification of the zebrafish embryo begins during oogenesis and relies on proper formation of well-defined cytoplasmic domains within the oocyte. Upon fertilization, maternally-regulated cytoplasmic flow and repositioning of dorsal determinants establish the coordinate system that will build the structure and developmental body plan of the embryo. Failure of specific genes that regulate the embryonic coordinate system leads to catastrophic loss of body structures.

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Forward genetic screens remain at the forefront of biology as an unbiased approach for discovering and elucidating gene function at the organismal and molecular level. Past mutagenesis screens targeting maternal-effect genes identified a broad spectrum of phenotypes ranging from defects in oocyte development to embryonic patterning. However, earlier vertebrate screens did not reach saturation, anticipated classes of phenotypes were not uncovered, and technological limitations made it difficult to pinpoint the causal gene.

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Red alga dulse possesses a unique xylan, which is composed of a linear β-(1→3)/β-(1→4)-xylosyl linkage. We previously prepared characteristic xylooligosaccharide (DX3, (β-(1→3)-xylosyl-xylobiose)) from dulse. In this study, we evaluated the prebiotic effect of DX3 on enteric bacterium.

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The first total synthesis of (7″,8″)-, (7″,8″)-isomers of princepin () and (7″,8″)-, (7″,8″)-isomers of isoprincepin () was accomplished in a highly stereoselective manner via quinomethide-mediated construction of the furofuran and 1,4-benzodioxane rings. Structural confirmation methods of and were established by CD and HPLC analysis of each diastereomers with natural products.

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A healthy 28-year-old woman presented suddenly with intractable status epilepticus: a focal seizure evolved into a generalized seizure preceded by a high fever. Brain magnetic resonance imaging indicated bilateral hyperintensities in the hippocampus on T2-weighted imaging. Electroencephalograms continuously demonstrated diffuse sharp waves and poly-spikes.

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In this study, we demonstrated that cationic liposomes with incorporated stearylamine (SA) inhibit viral infectivity without preloaded active pharmaceutical ingredients. Specifically, we correlated physiochemical properties of liposomes, such as zeta potentials and particle sizes, with virus infectivity using the BacMam™ reagent, which is based on recombinant baculovirus (BV). Compared with neutral or negatively-charged liposomes, SA liposomes suppressed BV infectivity in several mammalian cell lines, including A549 cells.

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Article Synopsis
  • A 44-year-old woman was diagnosed with both large-cell neuroendocrine carcinoma and uterine endometrioid carcinoma, leading to anti-NMDAR encephalitis characterized by psychosis and cognitive issues.
  • The diagnosis of paraneoplastic limbic encephalitis was confirmed after testing cerebrospinal fluid for anti-NMDAR antibodies, and histology showed a neuroendocrine tumor in metastatic samples.
  • Despite some improvement after tumor removal and intensive immune therapy, the patient ultimately died from multiple organ failure, highlighting the serious consequences of neuroendocrine tumors on neurological health.
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The light harvesting-reaction center (LH1-RC) complex from a new thermophilic purple sulfur bacterium Allochromatium (Alc.) tepidum was isolated and characterized by spectroscopic and thermodynamic analyses. The purified Alc.

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Germline and somatic cell distinction is regulated through a combination of microRNA and germ cell-specific RNA-binding proteins in zebrafish. An RNA-binding protein, DND, has been reported to relieve the miR-430-mediated repression of some germ plasm mRNAs such as nanos3 and tdrd7 in primordial germ cells (PGCs). Here, we showed that miR-430-mediated repression is not counteracted by the overexpression of DND protein in somatic cells.

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Background: It is extremely rare to see cerebrospinal fluid dissemination of intraventricular meningioma, particularly with the development of acute, progressive brainstem/cerebellar dysfunction with an absence of mass formation in the corresponding anatomical sites.

Case Presentation: An 81-year-old man was admitted because of double vision, right facial nerve palsy and truncal ataxia. Brain magnetic resonance imaging showed normal findings except for a tumor mass in the left lateral ventricle, which had been noted over 6 months previously.

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Background: Early recurrence of an embolism is rarely observed in patients with stroke treated with intravenous thrombolysis. Pre-existing cardiac thrombus is thought as a risk factor for recurrent embolism, although the relationship remains unclear.

Methods: The present patient was a 30-year-old man with acute ischemic stroke.

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