844 research outputs found

    miRNA/siRNA-directed pathway to produce noncoding piRNAs from endogenous protein-coding regions ensures Drosophila spermatogenesis

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    PIWI-interacting RNA (piRNA) pathways control transposable elements (TEs) and endogenous genes, playing important roles in animal gamete formation. However, the underlying piRNA biogenesis mechanisms remain elusive. Here, we show that endogenous protein coding sequences (CDSs), which are normally used for translation, serve as origins of noncoding piRNA biogenesis in Drosophila melanogaster testes. The product, namely, CDS-piRNAs, formed silencing complexes with Aubergine (Aub) in germ cells. Proximity proteome and functional analyses show that CDS-piRNAs and cluster/TE-piRNAs are distinct species occupying Aub, the former loading selectively relies on chaperone Cyclophilin 40. Moreover, Argonaute 2 (Ago2) and Dicer-2 activities were found critical for CDS-piRNA production. We provide evidence that Ago2-bound short interfering RNAs (siRNAs) and microRNAs (miRNAs) specify precursors to be processed into piRNAs.We further demonstrate that Aub is crucial in spermatid differentiation, regulating chromatins through mRNA cleavage. Collectively, our data illustrate a unique strategy used by male germ line, expanding piRNA repertoire for silencing of endogenous genes during spermatogenesis.Iki T., Kawaguchi S., Kai T.. miRNA/siRNA-directed pathway to produce noncoding piRNAs from endogenous protein-coding regions ensures Drosophila spermatogenesis. Science Advances 9, eadh0397 (2023); https://doi.org/10.1126/sciadv.adh0397

    Utilizing Moving Vehicles as Sensors for Bridge Condition Screening – A Laboratory Verification

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    Health condition monitoring of bridge structures is attracting considerable attention, conventionally relying on visual inspection, and measurement-based methods that involve sensors installed directly on bridges. In recent years, drive-by monitoring methods that treat moving vehicles as moving sensors have been proposed as alternatives; these methods aim to be lowcost, mobile, and target fast bridge condition screening. In this study, we address the current lack of sufficient experimental verification of such methods. Laboratory experiments were conducted using a test vehicle system equipped with accelerometers in order to verify the practical feasibility of three drive-by methods: (1) bridge-frequency extraction using the Fourier spectrum of a vehicle’s dynamic response, (2) damage detection using the change in a vehicle’s spectral distribution pattern, and (3) roadway surface profile identification

    Invasive Respiratory or Vasopressor Support and/or Death as a Proposed Composite Outcome Measure for Perioperative Care Research

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    BACKGROUND: There is a need for a clinically relevant and feasible outcome measure to facilitate clinical studies in perioperative care medicine. This large-scale retrospective cohort study proposed a novel composite outcome measure comprising invasive respiratory or vasopressor support (IRVS) and death. We described the prevalence of IRVS in patients undergoing major abdominal surgery and assessed the validity of combining IRVS and death to form a composite outcome measure. METHODS: We retrospectively collected perioperative data for 2776 patients undergoing major abdominal surgery (liver, colorectal, gastric, pancreatic, or esophageal resection) at Kyoto University Hospital. We defined IRVS as requirement for mechanical ventilation for ≥24 hours postoperatively, postoperative reintubation, or postoperative vasopressor administration. We evaluated the prevalence of IRVS within 30 postoperative days and examined the association between IRVS and subsequent clinical outcomes. The primary outcome of interest was long-term survival. Multivariable Cox proportional regression analysis was performed to adjust for the baseline patient and operative characteristics. The secondary outcomes were length of hospital stay and hospital mortality. RESULTS: In total, 85 patients (3.1%) received IRVS within 30 postoperative days, 15 of whom died by day 30. Patients with IRVS had a lower long-term survival rate (1- and 3-year survival probabilities, 66.1% and 48.5% vs 95.2% and 84.0%, respectively; P < .001, log-rank test) compared to those without IRVS. IRVS was significantly associated with lower long-term survival after adjustment for the baseline patient and operative characteristics (adjusted hazard ratio, 2.72; 95% confidence interval, 1.97–3.77; P < .001). IRVS was associated with a longer hospital stay (median [interquartile range], 65 [39–326] vs 15 [12–24] days; adjusted P < .001) and a higher hospital mortality (24.7% vs 0.5%; adjusted P < .001). Moreover, IRVS was adversely associated with subsequent clinical outcomes including lower long-term survival (adjusted hazard ratio, 1.78; 95% confidence interval, 1.21–2.63; P = .004) when the analyses were restricted to 30-day survivors. CONCLUSIONS: Patients with IRVS can experience ongoing risk of serious morbidity and less long-term survival even if alive at postoperative day 30. Our findings support the validity of using IRVS and/or death as a composite outcome measure for clinical studies in perioperative care medicine

    Differential roles of prostaglandin E-type receptors in activation of hypoxia-inducible factor 1 by prostaglandin E1 in vascular-derived cells under non-hypoxic conditions

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    Prostaglandin E1 (PGE1), known pharmaceutically as alprostadil, has vasodilatory properties and is used widely in various clinical settings. In addition to acute vasodilatory properties, PGE1 may exert beneficial effects by altering protein expression of vascular cells. PGE1 is reported to be a potent stimulator of angiogenesis via upregulation of VEGF expression, which is under the control of the transcription factor hypoxia-inducible factor 1 (HIF-1). However, the molecular mechanisms behind the phenomenon are largely unknown. In the present study, we investigated the mechanism by which PGE1 induces HIF-1 activation and VEGF gene expression in human aortic smooth muscle cells (HASMCs) and human umbilical vein endothelial cells (HUVECs), both vascular-derived cells. HUVECs and HASMCs were treated with PGE1 at clinically relevant concentrations under 20% O2 conditions and HIF-1 protein expression was investigated. Expression of HIF- 1α protein and the HIF-1-downstream genes were low under 20% O2 conditions and increased in response to PGE1 treatment in both HUVECs and HASMCs in a dose- and time-dependent manner under 20% O2 conditions as comparable to exposure to 1% O2 conditions. Studies using EP-receptor-specific agonists and antagonists revealed that EP1 and EP3 are critical to PGE1-induced HIF-1 activation. In vitro vascular permeability assays using HUVECs indicated that PGE1 increased vascular permeability in HUVECs. Thus, we demonstrate that PGE1 induces HIF- 1α protein expression and HIF-1 activation under non-hypoxic conditions and also provide evidence that the activity of multiple signal transduction pathways downstream of EP1 and EP3 receptors is required for HIF-1 activation

    Successful lung-protective ventilatory management during the VV-ECMO in a severe COVID-19 pneumonia patient with extensive pneumomediastinum and subcutaneous emphysema: a case report

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    BACKGROUND: Ventilatory management of respiratory failure with pneumomediastinum/subcutaneous emphysema is not established. Herein, we report a case of severe COVID-19 pneumonia with extensive pneumomediastinum/subcutaneous emphysema, rescued by thorough lung-protective ventilatory management after applying the VV-ECMO. CASE PRESENTATION: A 68-year-old male with no medical history was admitted to a local hospital and diagnosed with COVID-19 pneumonia. His pulmonary parameters worsened during invasive ventilation due to the development of pneumomediastinum/subcutaneous emphysema, and then he was transferred to our hospital. On arrival, we immediately decided to apply VV-ECMO and switch to ultraprotective ventilation. After maintaining the initial ventilation with a neuromuscular blocking agent for 2 days, we gradually increased PEEP while limiting PIP to 25 cmH2O. The patient was weaned off VV-ECMO on day 10; he was transferred to the medical ward after extubation. CONCLUSIONS: Lung-protective ventilatory management should be performed thoroughly during VV-ECMO in severe COVID-19 pneumonia with pneumomediastinum/subcutaneous emphysema

    Successful treatment of COVID‐19‐related acute respiratory distress syndrome with a rare blood type: A case report

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    Extracorporeal membrane oxygenation is indispensable for critically severe COVID-19 patients. However, it would be inapplicable to patients with a rare blood type or blood transfusion refusal. In that case, severely conservative fluid management with the sacrifice of renal functions and hydrocortisone therapy should be considered for better oxygenation

    Population pharmacokinetic modeling of GS‐441524, the active metabolite of remdesivir, in Japanese COVID‐19 patients with renal dysfunction

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    腎障害患者におけるレムデシビルの薬物動態モデルを構築 --新型コロナウイルス感染症治療薬の適正使用に向けて--. 京都大学プレスリリース. 2021-11-25.Remdesivir, a prodrug of the nucleoside analog GS-441524, plays a key role in the treatment of coronavirus disease 2019 (COVID-19). However, owing to limited information on clinical trials and inexperienced clinical use, there is a lack of pharmacokinetic (PK) data in patients with COVID-19 with special characteristics. In this study, we aimed to measure serum GS-441524 concentrations and develop a population PK (PopPK) model. Remdesivir was administered at a 200 mg loading dose on the first day followed by 100 mg from day 2, based on the package insert, in patients with an estimated glomerular filtration rate (eGFR) greater than or equal to 30 ml/min. In total, 190 concentrations from 37 Japanese patients were used in the analysis. The GS-441524 trough concentrations were significantly higher in the eGFR less than 60 ml/min group than in the eGFR greater than or equal to 60 ml/min group. Extracorporeal membrane oxygenation in four patients hardly affected the total body clearance (CL) and volume of distribution (Vd) of GS-441524. A one-compartment model described serum GS-441524 concentration data. The CL and Vd of GS-441524 were significantly affected by eGFR readjusted by individual body surface area and age, respectively. Simulations proposed a dose regimen of 200 mg on day 1 followed by 100 mg once every 2 days from day 2 in patients with an eGFR of 30 ml/min or less. In conclusion, we successfully established a PopPK model of GS-441524 using retrospectively obtained serum GS-441524 concentrations in Japanese patients with COVID-19, which would be helpful for optimal individualized therapy of remdesivir
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