126 research outputs found

    Protective Effects of Gastric Mucus

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    In vivo FRET analyses reveal a role of ATP hydrolysis–associated conformational changes in human P-glycoprotein

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    P-glycoprotein (P-gp; also known as MDR1 or ABCB1) is an ATP-driven multidrug transporter that extrudes various hydrophobic toxic compounds to the extracellular space. P-gp consists of two transmembrane domains (TMDs) that form the substrate translocation pathway and two nucleotide-binding domains (NBDs) that bind and hydrolyze ATP. At least two P-gp states are required for transport. In the inward-facing (pre-drug transport) conformation, the two NBDs are separated, and the two TMDs are open to the intracellular side; in the outward-facing (post-drug transport) conformation, the NBDs are dimerized, and the TMDs are slightly open to the extracellular side. ATP binding and hydrolysis cause conformational changes between the inward-facing and the outward-facing conformations, and these changes help translocate substrates across the membrane. However, how ATP hydrolysis is coupled to these conformational changes remains unclear. In this study, we used a new FRET sensor that detects conformational changes in P-gp to investigate the role of ATP binding and hydrolysis during the conformational changes of human P-gp in living HEK293 cells. We show that ATP binding causes the conformational change to the outward-facing state and that ATP hydrolysis and subsequent release of γ-phosphate from both NBDs allow the outward-facing state to return to the original inward-facing state. The findings of our study underscore the utility of using FRET analysis in living cells to elucidate the function of membrane proteins such as multidrug transporters

    An ex vivo system to study cellular dynamics underlying mouse peri-implantation development

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    マウスの着床期の胚発生を三次元で再現することに成功. 京都大学プレスリリース. 2022-02-09.Upon implantation, mammalian embryos undergo major morphogenesis and key developmental processes such as body axis specification and gastrulation. However, limited accessibility obscures the study of these crucial processes. Here, we develop an ex vivo Matrigel-collagen-based culture to recapitulate mouse development from E4.5 to E6.0. Our system not only recapitulates embryonic growth, axis initiation, and overall 3D architecture in 49% of the cases, but its compatibility with light-sheet microscopy also enables the study of cellular dynamics through automatic cell segmentation. We find that, upon implantation, release of the increasing tension in the polar trophectoderm is necessary for its constriction and invagination. The resulting extra-embryonic ectoderm plays a key role in growth, morphogenesis, and patterning of the neighboring epiblast, which subsequently gives rise to all embryonic tissues. This 3D ex vivo system thus offers unprecedented access to peri-implantation development for in toto monitoring, measurement, and spatiotemporally controlled perturbation, revealing a mechano-chemical interplay between extra-embryonic and embryonic tissues

    キャリア ケイセイ シエン キョウイク プログラム ノ カイハツ ト キョウイク コウカ ノ ヒョウカ : チーム イリョウ タイケン ガクシュウ ノ ジッセンテキ ケンキュウ オ トオシテ

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    我々は歯学部学生のキャリア形成支援のための教育プログラム「チーム医療体験学習」を開発し, 歯学部の2,3,4年次の学生を対象として実施した。本プログラムは,グループワークによる事前学 習とチーム医療の現場体験を2つの柱とし,学生の歯科医療職としてのキャリア意識を強化することを 目的とした。プログラム終了時のアンケートから,学生には歯科専門職としての将来の姿勢や目指す方 向性が具体化すると同時に幅広い知識を身につけたいといった学習に対する動機付が強化されるなど 明らかな教育成果が認められた。プログラム実施前後のアンケートの分析結果から, 「チーム医療体験 学習」が歯学部学生のキャリア形成支援教育の手法として有効なプログラムである可能性が示唆された。We prepared career advancement program “Experience learning in medical team treatment" towards the second,third and fouth year students of dental school. This program consits of prior learning concerned with 'Team treatment and Dental profession' and experience learning in medical team treatment at Tokushima University Hospital. The purpose of this program was to rouse career conciousness as a dental profession. This program provided students with career image which they want to be in the future. Besides,they were motivated to study more widely to approach their own image. In this paper,we evaluated the effects of the program“The experience learning in medical team treatment" on career advancement of dental school students. As a result,it is suggested that this program might be fruitful as career advancement on dental students

    Prognostic factors and effect modifiers for personalisation of internet-based cognitive behavioural therapy among university students with subthreshold depression: A secondary analysis of a factorial trial

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    BACKGROUND: Internet-cognitive behavioural therapy (iCBT) for depression can include multiple components. This study explored depressive symptom improvement prognostic factors (PFs) and effect modifiers (EMs) for five common iCBT components including behavioural activation, cognitive restructuring, problem solving, self-monitoring, and assertion training. METHODS: We used data from a factorial trial of iCBT for subthreshold depression among Japanese university students (N = 1093). The primary outcome was the change in PHQ-9 scores at 8 weeks from baseline. Interactions between each component and various baseline characteristics were estimated using a mixed-effects model for repeated measures. We calculated multiplicity-adjusted p-values at 5 % false discovery rate using the Benjamini-Hochberg procedure. RESULTS: After multiplicity adjustment, the baseline PHQ-9 total score emerged as a PF and exercise habits as an EM for self-monitoring (adjusted p-values <0.05). The higher the PHQ-9 total score at baseline (range: 5-14), the greater the decrease after 8 weeks. For each 5-point increase at baseline, the change from baseline to 8 weeks was bigger by 2.8 points. The more frequent the exercise habits (range: 0-2 points), the less effective the self-monitoring component. The difference in PHQ-9 change scores between presence or absence of self-monitoring was smaller by 0.94 points when the participant exercised one level more frequently. Additionally, the study suggested seven out of 36 PFs and 14 out of 160 EMs examined were candidates for future research. LIMITATIONS: Generalizability is limited to university students with subthreshold depression. CONCLUSIONS: These results provide some helpful information for the future development of individualized iCBT algorithms for depression

    Components of smartphone cognitive-behavioural therapy for subthreshold depression among 1093 university students: a factorial trial

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    BACKGROUND: Internet-based cognitive-behavioural therapy (iCBT) is effective for subthreshold depression. However, which skills provided in iCBT packages are more effective than others is unclear. Such knowledge can inform construction of more effective and efficient iCBT programmes. OBJECTIVE: To examine the efficacy of five components of iCBT for subthreshold depression. METHODS: We conducted an factorial trial using a smartphone app, randomly allocating presence or absence of five iCBT skills including self-monitoring, behavioural activation (BA), cognitive restructuring (CR), assertiveness training (AT) and problem-solving. Participants were university students with subthreshold depression. The primary outcome was the change on the Patient Health Questionnaire-9 (PHQ-9) from baseline to week 8. Secondary outcomes included changes in CBT skills. FINDINGS: We randomised a total of 1093 participants. In all groups, participants had a significant PHQ-9 reduction from baseline to week 8. Depression reduction was not significantly different between presence or absence of any component, with corresponding standardised mean differences (negative values indicate specific efficacy in favour of the component) ranging between -0.04 (95% CI -0.16 to 0.08) for BA and 0.06 (95% CI -0.06 to 0.18) for AT. Specific CBT skill improvements were noted for CR and AT but not for the others. CONCLUSIONS: There was significant reduction in depression for all participants regardless of the presence and absence of the examined iCBT components. CLINICAL IMPLICATION: We cannot yet make evidence-based recommendations for specific iCBT components. We suggest that future iCBT optimisation research should scrutinise the amount and structure of components to examine. TRIAL REGISTRATION NUMBER: UMINCTR-000031307

    A Clinical Trial Evaluating the Usefulness of Tailored Antimicrobial Prophylaxis Using Rectal-culture Screening Media Prior to Transrectal Prostate Biopsy: A Multicenter, Randomized Controlled Trial

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    The aim of this report is to introduce an on-going, multicenter, randomized controlled trial to evaluate whether tailored antimicrobial prophylaxis guided by rectal culture screening prevents acute bacterial prostatitis following transrectal prostate biopsy (TRPB). Patients will be randomized into an intervention or non-intervention group; tazobactam-piperacillin or levofloxacin will be prophylactically administered according to the results of rectal culture prior to TRPB in the intervention group whereas levofloxacin will be routinely given in the non-intervention group. The primary endpoint is the occurrence rate of acute bacterial prostatitis after TRPB. Recruitment begins in April, 2021 and the target total sample size is 5,100 participants

    LRRK2 Phosphorylates Tubulin-Associated Tau but Not the Free Molecule: LRRK2-Mediated Regulation of the Tau-Tubulin Association and Neurite Outgrowth

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    Leucine-rich repeat kinase 2 (LRRK2), a large protein kinase containing multi-functional domains, has been identified as the causal molecule for autosomal-dominant Parkinson's disease (PD). In the present study, we demonstrated for the first time that (i) LRRK2 interacts with tau in a tubulin-dependent manner; (ii) LRRK2 directly phosphorylates tubulin-associated tau, but not free tau; (iii) LRRK2 phosphorylates tau at Thr181 as one of the target sites; and (iv) The PD-associated LRRK2 mutations, G2019S and I2020T, elevated the degree of tau-phosphorylation. These results provide direct proof that tau is a physiological substrate for LRRK2. Furthermore, we revealed that LRRK2-mediated phosphorylation of tau reduces its tubulin-binding ability. Our results suggest that LRRK2 plays an important role as a physiological regulator for phosphorylation-mediated dissociation of tau from microtubules, which is an integral aspect of microtubule dynamics essential for neurite outgrowth and axonal transport
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