60 research outputs found

    Generation of Tetrafluoroethylene–Propylene Elastomer-Based Microfluidic Devices for Drug Toxicity and Metabolism Studies

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    フッ素系エラストマー素材を用いた肝臓チップの開発と薬物代謝・毒性試験への応用. 京都大学プレスリリース. 2021-09-16.Drug testing on miniatured livers. 京都大学プレスリリース. 2021-09-17.Polydimethylsiloxane (PDMS) is widely used to fabricate microfluidic organs-on-chips. Using these devices (PDMS-based devices), the mechanical microenvironment of living tissues, such as pulmonary respiration and intestinal peristalsis, can be reproduced in vitro. However, the use of PDMS-based devices in drug discovery research is limited because of their extensive absorption of drugs. In this study, we investigated the feasibility of the tetrafluoroethylene–propylene (FEPM) elastomer to fabricate a hepatocyte-on-a-chip (FEPM-based hepatocyte chip) with lower drug absorption. The FEPM-based hepatocyte chip expressed drug-metabolizing enzymes, drug-conjugating enzymes, and drug transporters. Also, it could produce human albumin. Although the metabolites of midazolam and bufuralol were hardly detected in the PDMS-based hepatocyte chip, they were detected abundantly in the FEPM-based hepatocyte chip. Finally, coumarin-induced hepatocyte cytotoxicity was less severe in the PDMS-based hepatocyte chip than in the FEPM-based hepatocyte chip, reflecting the different drug absorptions of the two chips. In conclusion, the FEPM-based hepatocyte chip could be a useful tool in drug discovery research, including drug metabolism and toxicity studies

    Radiated tumor cell-derived microparticles effectively kill stem-like tumor cells by increasing reactive oxygen species

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    Stem-like tumor cells (SLTCs) are thought to be the cellular entity responsible for clinical recurrence and subsequent metastasis. Inhibiting or killing SLTCs can effectively reduce recurrence and metastasis, yet little has been done to clear SLTCs because they are usually resistant to chemotherapy, radiotherapy, and even immunotherapy. In this study, we established SLTCs by low-serum culture and confirmed that the low-serum-cultured tumor cells were in a quiescent state and resistant to chemotherapy, showing features of SLTCs, consistent with the reported data. We demonstrated that SLTCs had high levels of reactive oxygen species (ROS). Based on the finding that radiated tumor cell-derived microparticles (RT-MPs) contained ROS, we used RT-MPs to kill SLTCs. We found that RT-MPs could further increase ROS levels and kill SLTCs in vivo and in vitro partially by ROS carried by the RT-MPs themselves, providing a new method for eliminating SLTCs

    Lateral organization and dynamics of phospholipids in membrane

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    Studies of the lateral organization and dynamics of phospholipids were carried out using fluorescence techniques and enzymatic methods. Using resonance energy transfer, no specific interactions were observed between gramicidin and dansyl-labeled phosphatidylcholine, phosphatidylethanolamine, or phosphatidic acid. However, another integral membrane protein, D-β\beta-hydroxybutyrate dehydrogenase (BDH), reorganized the phospholipids in the bilayer into a nonrandom distribution. Although the enzyme has a specific requirement for phosphatidylcholine for activity, the extent of energy transfer decreased in the order phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine.A strong interaction between BDH and phosphatidic acid was also observed with enzymatic methods. Phosphatidylcholine fully activated BDH only in the presence, but not in the absence, of phosphatidic acid in the vesicle. This is consistent with a mechanism where phosphatidic acid enhances the binding of BDH to membranes.A redistribution of both gramicidin and dansyl-labeled phospholipids was easily observed when a phase separation was induced by adding Ca\sp{2+} to vesicles made up of phosphatidylcholine and phosphatidic acid. Energy transfer measurements from gramicidin to either dansyl-phosphatidylcholine or dansyl-phosphatidic acid showed gramicidin preferentially partitioned into the phosphatidylcholine-rich regions. In the same system, two distributed fluorescence lifetimes or rotational correlation times were required to fit the data acquired with phase fluorometry for the dansyl-phospholipids and dansyl-gramicidin. Some of the dynamic parameters varied in different lipid domains. BDH appeared to partition into phosphatidylcholine-rich regions as detected by the changes in the Michaelis-Menten constants.The orientations of diphenyl-hexatriene (DPH) in vesicle bilayers were studied using phase fluorometry and global analysis. The distributions were wide in the fluid phases and they narrowed dramatically in the gel phases. By linking the time zero anisotropy (r\sb{\rm o}) of several sets of data taken at various temperatures in a single global analysis, between recovery of the rank order parameters, the diffusion constant and r\sb{\rm o} were obtained. The results suggest that a single distributed population of DPH was present in the bilayers with their orientational distributions dependent upon the physical state of the membrane.U of I OnlyETDs are only available to UIUC Users without author permissio

    Transcriptome and Physiological Analysis Highlight Lignin Metabolism of the Fruit Dots Disordering during Postharvest Cold Storage in ‘Danxiahong’ Pear

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    Pear (Pyrus L.) is one of the most important fruits in the world. Fruit dots are an important trait that affects pear quality. Abnormal fruit dots usually reduce the merchantability of pears. In this research, during cold storage, ‘Danxiahong’ pear fruit exhibited protrudent fruit dots on the peels. Microscopy system measurement showed that fruit dots size and height on the abnormal fruit peel were bigger and higher than the normal ones. Likewise, scanning electron microscopy observations indicated that the abnormal fruit peel, in contrast to the normal pear peel, exhibited an abnormal cell structure and fruit dots. Physiological analysis showed that the lignin content in abnormal fruit peel was significantly higher than in normal fruit peel. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the top-enriched pathways were mainly associated with lignin synthesis and metabolism. The transcripts of lignin biosynthesis-associated genes were analyzed, and the results showed that the expression of a cascade of structural genes, including PpyPAL, PpyCCR, PpyC3H, PpyC4H, PpyHCT, PpyCAD, PpyLAC, and PpyPOD, was significantly induced in the protrudent peels. Furthermore, the expression of regulatory genes involved in lignin biosynthesis, especially the NAC-MYB-based gene regulatory network, was significantly upregulated in the abnormal peels. Real-time quantitative PCR (RT-qPCR) analysis confirmed the induction of lignin biosynthesis genes. Overall, this research revealed that the abnormal fruit surface was caused by fruit dots disorder during cold storage. This research provides insights into the fine regulation pathways in the prevention of fruit dots protrusion, especially in modulating lignin synthesis and metabolism during postharvest storage

    Transcriptome Analysis Reveals Roles of Sucrose in Anthocyanin Accumulation in ‘Kuerle Xiangli’ (<i>Pyrus sinkiangensis</i> Yü)

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    Pear (Pyrus L.) is one of the most important temperate fruit crops worldwide, with considerable economic value and significant health benefits. Red-skinned pears have an attractive appearance and relatively high anthocyanin accumulation, and are especially favored by customers. Abnormal weather conditions usually reduce the coloration of red pears. The application of exogenous sucrose obviously promotes anthocyanins accumulation in ‘Kuerle Xiangli’ (Pyrus sinkiangensis Yü); however, the underlying molecular mechanism of sucrose-mediated fruit coloration remains largely unknown. In this study, comprehensive transcriptome analysis was performed to identify the essential regulators and pathways associated with anthocyanin accumulation. The differentially expressed genes enriched in Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes items were analyzed. The transcript levels of some anthocyanin biosynthetic regulatory genes and structural genes were significantly induced by sucrose treatment. Sucrose application also stimulated the expression of some sugar transporter genes. Further RT-qPCR analysis confirmed the induction of anthocyanin biosynthetic genes. Taken together, the results revealed that sucrose promotes pear coloration most likely by regulating sugar metabolism and anthocyanin biosynthesis, and this study provides a comprehensive understanding of the complex molecular mechanisms underlying the coloration of red-skinned pear

    Randomised controlled trials evaluating endometrial scratching: assessment of methodological issues

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    STUDY QUESTION:Do randomised controlled trials (RCTs) evaluating endometrial scratching suffer from methodological issues including insufficient trial registration, statistical errors or irreproducibility, randomisation errors or miscellaneous issues? SUMMARY ANSWER:The majority of RCTs investigating endometrial scratching have methodological issues. WHAT IS KNOWN ALREADY:A large number of small RCTs investigating the effectiveness of endometrial scratching prior to in vitro fertilisation (IVF) and intrauterine insemination (IUI)/intercourse have reported favourable findings. Subsequently, systematic reviews incorporating these RCTs yielded meta-analyses in favour of endometrial scratching. Endometrial scratching has been widely adopted by infertility specialists around the world. Recently, an international RCT including 1364 women reported no benefit from endometrial scratching before IVF. STUDY DESIGN, SIZE, DURATION:We evaluated several methodological issues of RCTs investigating the effectiveness of endometrial scratching prior to IVF and IUI/intercourse. We identified 25 RCTs for IVF and 12 RCTs for IUI/intercourse with full-text publication. PARTICIPANTS/MATERIALS, SETTING, METHODS:We assessed the RCTs on the following criteria: adequacy of trial registration, statistical issues (description of statistical methods and reproducibility of univariable statistical analysis), excessive similarity or difference in baseline characteristics that is not compatible with chance (Monte Carlo simulations and Kolmogorov-Smirnov test) and miscellaneous methodological issues. MAIN RESULTS AND THE ROLE OF CHANCE:Of 25 RCTs evaluating endometrial scratching prior to IVF, only eight (32%) had adequate trial registration. In total, 10 (40%) RCTs had issues regarding statistical methods. Nine (69%, 13 applicable) RCTs had at least one inconsistency between reported and reproduced univariable statistical analysis for categorical baseline/intermediate characteristics. Statistical results of at least one outcome were not reproducible in 14 (74%, 19 applicable) RCTs. Only two (8%) RCTs had none of the above issues. Suggested by the simulations, these RCTs did not significantly violate the null hypothesis that the baseline characteristics were the results of a properly conducted randomisation process (P = 0.4395).Of 12 IUI/intercourse RCTs, only 2 (17%) had adequate trial registration. In total, five (42%) studies had issues of statistical methods. Inconsistency between reported and reproduced univariable analysis for baseline/intermediate categorical variable(s) was found in four (57%, 7 applicable) RCTs. Statistical analysis was not reproducible for at least one outcome in eight (80%, 10 applicable) studies. All RCTs had at least one of the above issues. These RCTs were inconsistent with the null hypothesis that their baseline characteristics were the results of proper randomised allocation (P = 1.659*10-7). LIMITATIONS, REASONS FOR CAUTION:We were unable to assess RCTs which were not published as full-text papers. We could not analyse individual participant data to investigate possible reasons for statistical inconsistencies. The method to infer the likelihood of proper random sampling rests on assumptions including independent baseline characteristics, simple randomisation and no publication bias. WIDER IMPLICATIONS OF THE FINDINGS:The methodological issues common to RCTs evaluating endometrial scratching may have biased the results of the trials. Further development and validation of these novel methods may be helpful for the critical appraisal of RCTs. STUDY FUNDING/COMPETING INTEREST(S):No external funding was sought to support this work. B.W.M. is supported by a National Health Medical Research Council (NHMRC) Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck and Guerbet. D.W. is supported by a grant from the Paracelsus Medical University Salzburg, Austria (PMU Research Fund-PMU FFF Number: L-18/02/006-WET) and by Drs Haackert Foundation, Germany. S.L. is an author of a trial included in this study, an author of an included systematic review and a Cochrane editor. All other authors have no conflicts of interest. TRIAL REGISTRATION NUMBER:N/A.Wentao Li, Sophie Suke, Dagmar Wertaschnigg, Sarah Lensen, Rui Wang, Lyle Gurrin, Ben W Mo

    Additional file 2: Figure S1. of Identification of candidate genes involved in the sugar metabolism and accumulation during pear fruit post-harvest ripening of ‘Red Clapp’s Favorite’ (Pyrus communis L.) by transcriptome analysis

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    The pathway of starch and sucrose metabolism. Note: PCP008001 and PCP030959 were involved in the process of 3.2.1.26 (Marked in red); PCP011895 was involved in the process of 3.1.1.11 (Marked in blue); PCP006674 was involved in the process of 2.4.1.15 and 3.1.3.12 (Marked in blue); a novel gene 004807 was involved in the process of 2.7.7.27 (Marked in green). (JPEG 396 kb

    The genetic locus underlying red foliage and fruit skin traits is mapped to the same location in the two pear bud mutants ‘Red Zaosu’ and ‘Max Red Bartlett’

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    Abstract Background Red-skinned pears are attractive to consumers because of their aesthetic appeal and the antioxidant-associated health benefits provided by the anthocyanins in their red skin. In China, the ‘Red Zaosu’ (RZS) red bud mutation of the Zaosu (ZS) pear has been used as a parent in Asian pear breeding to generate new cultivars with crispy red fruit and red tender shoots resembling those of the ‘Max Red Bartlett’ (MRB) pears. Results In this study, a segregation ratio of 1:1 was observed between plants with red or green shoots in four families with RZS as the only red shoot gene donor parent, suggesting that the red shoot trait of RZS is associated with a dominant gene. Three markers, In1400–1, In1579–1 and In1579–3, were chosen from 22 pairs of indel primers targeting regions in the vicinity of the previously identified red fruit skin locus of MRB and were able to effectively distinguish the eight red shoot plants from the eight green shoot plants. Linkage analysis indicated that the genetic distance between the two marker loci (In1579–1 and In1579–3) and the red shoot locus of RZS were both 1.4 cM, while the genetic distance between the In1400–1 marker and the red shoot locus was 2.1 cM. The physical position of the red locus in RZS should be in the 368.6 kb candidate interval at the bottom of LG4. Conclusions The genetic locus responsible for the red tender shoots of RZS was located in the same interval of the red fruit skin gene of MRB, meaning that the bud mutation loci of RZS and MRB may be the same or adjacent to each other, and the red shoot trait and the red fruit skin trait in RZS may be controlled by the same, or a closely linked locus. As a result, breeders could use red shoots as a morphological marker to select for the red-skinned hybrids from RZS families
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