85 research outputs found

    Evaluation of corneal damage caused by the anticancer drug S-1 in human corneal epithelial cells

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    The combination drug S-1, which contains tegafur, gimeracil, and oteracil potassium, is a fluoropyrimidine-based oral antineoplastic agent in which the principal drug tegafur is a prodrug of fluorouracil (5-FU). In recent years, many studies have reported eye problems, especially corneal damage, as an adverse effect of S-1 treatment. In this study, we investigated the cytotoxic effects of each of the constituents of S-1 on corneal epithelial cells by measuring viable cell counts and lactate dehydrogenase (LDH) release. Experimental chemosensitivity study for 5-FU and the constituents of S-1 (i.e., tegafur, gimeracil, and oteracil) using a human cell line. We used immortalized human corneal epithelial (HCE-T) cells to estimate viable cell counts (expressed as a percentage of the control cells) and the activity of LDH in a culture medium (expressed as a percentage of the total LDH activity). Decreases in viable cell counts were noted with 5-FU and tegafur, but a significant elevation in LDH activity was noted only with tegafur. The incidence of damage in cells exposed to tegafur significantly decreased on adding tranylcypromine, an inhibitor of CYP2A6 that metabolizes tegafur to 5-FU. In addition, 5-FU did not elevate LDH activity, which is an indicator of cell membrane disruption, and concentration-dependence was not observed when cells were treated with 5-FU doses of up to 1,000ng/ml. These findings suggest that the disruption of the metabolic activity of the corneal epithelium by 5-FU is involved in the corneal injury mechanism of S-1

    NmeCas9 is an intrinsically high-fidelity genome editing platform [preprint]

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    Background: The development of CRISPR genome editing has transformed biomedical research. Most applications reported thus far rely upon the Cas9 protein from Streptococcus pyogenes SF370 (SpyCas9). With many RNA guides, wild-type SpyCas9 can induce significant levels of unintended mutations at near-cognate sites, necessitating substantial efforts toward the development of strategies to minimize off-target activity. Although the genome-editing potential of thousands of other Cas9 orthologs remains largely untapped, it is not known how many will require similarly extensive engineering to achieve single-site accuracy within large (e.g. mammalian) genomes. In addition to its off-targeting propensity, SpyCas9 is encoded by a relatively large (~4.2 kb) open reading frame, limiting its utility in applications that require size-restricted delivery strategies such as adeno-associated virus vectors. In contrast, some genome-editing-validated Cas9 orthologs (e.g. from Staphylococcus aureus, Campylobacter jejuni, Geobacillus stearothermophilus and Neisseria meningitidis) are considerably smaller and therefore better suited for viral delivery. Results: Here we show that wild-type NmeCas9, when programmed with guide sequences of natural length (24 nucleotides), exhibits a nearly complete absence of unintended editing in human cells, even when targeting sites that are prone to off-target activity with wildtype SpyCas9. We also validate at least six variant protospacer adjacent motifs (PAMs), in addition to the preferred consensus PAM (5′-N4GATT-3′), for NmeCas9 genome editing in human cells. Conclusions: Our results show that NmeCas9 is a naturally high-fidelity genome editing enzyme and suggest that additional Cas9 orthologs may prove to exhibit similarly high accuracy, even without extensive engineering

    NmeCas9 is an intrinsically high-fidelity genome-editing platform

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    BACKGROUND: The development of CRISPR genome editing has transformed biomedical research. Most applications reported thus far rely upon the Cas9 protein from Streptococcus pyogenes SF370 (SpyCas9). With many RNA guides, wildtype SpyCas9 can induce significant levels of unintended mutations at near-cognate sites, necessitating substantial efforts toward the development of strategies to minimize off-target activity. Although the genome-editing potential of thousands of other Cas9 orthologs remains largely untapped, it is not known how many will require similarly extensive engineering to achieve single-site accuracy within large genomes. In addition to its off-targeting propensity, SpyCas9 is encoded by a relatively large open reading frame, limiting its utility in applications that require size-restricted delivery strategies such as adeno-associated virus vectors. In contrast, some genome-editing-validated Cas9 orthologs are considerably smaller and therefore better suited for viral delivery. RESULTS: Here we show that wildtype NmeCas9, when programmed with guide sequences of the natural length of 24 nucleotides, exhibits a nearly complete absence of unintended editing in human cells, even when targeting sites that are prone to off-target activity with wildtype SpyCas9. We also validate at least six variant protospacer adjacent motifs (PAMs), in addition to the preferred consensus PAM (5\u27-N4GATT-3\u27), for NmeCas9 genome editing in human cells. CONCLUSIONS: Our results show that NmeCas9 is a naturally high-fidelity genome-editing enzyme and suggest that additional Cas9 orthologs may prove to exhibit similarly high accuracy, even without extensive engineering

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    We confirmed the bibliographic notes of literature on "home economics, home life and history of life", "economics of home", "family, home and marriage" and "home science" before World War II. The literature were picked up from "KASEIGAKU-SEIRITSU-SHI" written by TUNEMI and 25 books on philosophy of home economics. The results were as follows : (1) 82%, 314 literature of 382 objects were confirmed. (2) 91% of 382 objects had some unsatisfactory or mistaken notes. 85% of publishers, 33% of published year, 24% of title and 5% of editors or authors, had the unsatisfatory or mistaken notes. (3) 189 literature which had the unsatisfactory or mistaken notes except publishers only, were listed with supplied or revised

    Nutrition intake among the Japanese elderly: an intergenerational comparison based on national health and nutrition survey scores

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    Context: The average Japanese lifespan became the longest in the world in 1986. What factors give the Japanese this longevity? Washoku, or the traditional Japanese diet, is respected globally for its nutritionally-balanced and healthy eating habits. This uniquely Japanese way of eating may be one factor that helps extend the Japanese lifespan. Objective: To explain the nutrition intake characteristics of today’s Japanese elderly compared with their children’s generation and to discuss the association between nutrition intake and various diseases and health issues in the general adult population. Methods: This study compared the characteristics of nutrition status and nutrition intake among today’s elderly and their children’s generation by using National Health and Nutrition Survey scores. Results: Japanese elderly had high adequacy in all nutrients as well as a high intake of potatoes, pulses, vegetables, fruits, algae, and fish and shellfish compared with their children’s generation. Conclusion: Nutrition intake among the Japanese elderly had the characteristics of washoku, but these characteristics were not passed on to the next generation. Extension of the average lifespan and improved health could be achieved by modifying nutrition intake, even after reaching the age of onset of lifestyle- and age-related diseases, typically the 50s

    Organelle Zones

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