Hokkaido University

About: Hokkaido University is a education organization based out in Sapporo, Hokkaidô, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 53925 authors who have published 115403 publications receiving 2651647 citations. The organization is also known as: Hokudai & Hokkaidō daigaku.

The CHEMDNER corpus of chemicals and drugs and its annotation principles.

Abstract: The automatic extraction of chemical information from text requires the recognition of chemical entity mentions as one of its key steps. When developing supervised named entity recognition (NER) systems, the availability of a large, manually annotated text corpus is desirable. Furthermore, large corpora permit the robust evaluation and comparison of different approaches that detect chemicals in documents. We present the CHEMDNER corpus, a collection of 10,000 PubMed abstracts that contain a total of 84,355 chemical entity mentions labeled manually by expert chemistry literature curators, following annotation guidelines specifically defined for this task. The abstracts of the CHEMDNER corpus were selected to be representative for all major chemical disciplines. Each of the chemical entity mentions was manually labeled according to its structure-associated chemical entity mention (SACEM) class: abbreviation, family, formula, identifier, multiple, systematic and trivial. The difficulty and consistency of tagging chemicals in text was measured using an agreement study between annotators, obtaining a percentage agreement of 91. For a subset of the CHEMDNER corpus (the test set of 3,000 abstracts) we provide not only the Gold Standard manual annotations, but also mentions automatically detected by the 26 teams that participated in the BioCreative IV CHEMDNER chemical mention recognition task. In addition, we release the CHEMDNER silver standard corpus of automatically extracted mentions from 17,000 randomly selected PubMed abstracts. A version of the CHEMDNER corpus in the BioC format has been generated as well. We propose a standard for required minimum information about entity annotations for the construction of domain specific corpora on chemical and drug entities. The CHEMDNER corpus and annotation guidelines are available at: http://www.biocreative.org/resources/biocreative-iv/chemdner-corpus/

The polyethyleneglycol dilemma: advantage and disadvantage of PEGylation of liposomes for systemic genes and nucleic acids delivery to tumors.

Abstract: Gene and nucleic acid therapy is expected to play a major role in the next generation of agents for cancer treatment. We have recently developed a multifunctional envelope-type nano device (MEND) for use as a novel nonviral gene delivery system. The modification of polyethyleneglycol (PEG), i.e., PEGylation, is a useful method for achieving a longer circulation time for the delivery of MEND to a tumor via the enhanced permeability and retention (EPR) effect. However, PEGylation strongly inhibits cellular uptake and endosomal escape, which results in significant loss of activity of the delivery system. For successful nucleic acid delivery for cancer treatment, the crucial problem associated with the use of PEG, i.e., the "PEG dilemma" must be resolved. In this review, we describe the development and applications of MEND and discuss various strategies for overcoming the PEG dilemma based on the manipulation of both pharmacokinetics and intracellular trafficking of cellular uptake and endosomal release. To increase cellular uptake, target ligands including proteins, peptides, antibodies and aptamers that recognize molecules specifically expressed on tumors are first introduced. Second, cleavable PEG systems are described. The cleavage of PEG from carriers was achieved in response to the intracellular environment as well as the tumor microenvironment, which improvs cellular uptake and endosomal escape. Then, endosomal fusogenic peptides are discussed. Finally, pH-sensitive liposomes using pH-sensitive lipids are described.

Advanced Glycation End Products in Alzheimer's Disease and Other Neurodegenerative Diseases

Abstract: Advanced glycation end products (AGEs) have been implicated in the chronic complications of diabetes mellitus and have been reported to play an important role in the pathogenesis of Alzheimer's disease. In this study, we examined the immunohistochemical localization of AGEs, amyloid β protein (Aβ), apolipoprotein E (ApoE), and tau protein in senile plaques, neurofibrillary tangles (NFTs), and cerebral amyloid angiopathy (CAA) in Alzheimer's disease and other neurodegenerative diseases (progressive supranuclear palsy, Pick's disease, and Guamanian amyotrophic lateral sclerosis/Parkinsonism-dementia complex). In most senile plaques (including diffuse plaques) and CAA from Alzheimer's brains, AGE and ApoE were observed together. However, approximately 5% of plaques were AGE positive but Aβ negative, and the vessels without CAA often showed AGE immunoreactivity. In Alzheimer's disease, AGEs were mainly present in intracellular NFTs, whereas ApoE was mainly present in extracellular NFTs. Pick's bodies in Pick's disease and granulovacuolar degeneration in various neurodegenerative diseases were also AGE positive. In non-Alzheimer neurodegenerative diseases, senile plaques and NFTs showed similar findings to those in Alzheimer's disease. These results suggest that AGE may contribute to eventual neuronal dysfunction and death as an important factor in the progression of various neurodegenerative diseases, including Alzheimer's disease.