212 research outputs found

    Cell cycle-specific phase separation regulated by protein charge blockiness

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    Dynamic morphological changes of intracellular organelles are often regulated by protein phosphorylation or dephosphorylation1-6. Phosphorylation modulates stereospecific interactions among structured proteins, but how it controls molecular interactions among unstructured proteins and regulates their macroscopic behaviours remains unknown. Here we determined the cell cycle-specific behaviour of Ki-67, which localizes to the nucleoli during interphase and relocates to the chromosome periphery during mitosis. Mitotic hyperphosphorylation of disordered repeat domains of Ki-67 generates alternating charge blocks in these domains and increases their propensity for liquid–liquid phase separation (LLPS). A phosphomimetic sequence and the sequences with enhanced charge blockiness underwent strong LLPS in vitro and induced chromosome periphery formation in vivo. Conversely, mitotic hyperphosphorylation of NPM1 diminished a charge block and suppressed LLPS, resulting in nucleolar dissolution. Cell cycle-specific phase separation can be modulated via phosphorylation by enhancing or reducing the charge blockiness of disordered regions, rather than by attaching phosphate groups to specific sites

    Relationship between GnRH-induced LH increase profiles

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    This study aimed to investigate the relationship between increases in the luteinizing hormone (LH) profiles in the serum and vaginal mucus of cows induced by gonadotropin-releasing hormone (GnRH). Samples for LH determination were collected from Japanese Black beef cows during estrus, which was induced with a controlled internal progesterone-releasing device and the administration of cloprostenol immediately before GnRH administration and every 30 min from the start of GnRH administration until 6.5 h. The peak serum LH concentration was clearly identified at 2.5 h post-GnRH administration, with serum concentrations returning to near-pre-GnRH-administration values after 6.5 h, whereas the peak vaginal mucus LH concentration was identified 4.5 h after GnRH administration. These results indicate that the LH secretion peak in vaginal mucus appeared about 2 h after peak LH secretion in the serum

    Eicosapentaenoic Acid Suppresses the Proliferation of Synoviocytes from Rheumatoid Arthritis

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    Eicosapentaenoic acid (EPA) is essential for normal cell growth, and may play an important role in inflammatory and autoimmune disorders including rheumatoid arthritis. We investigate that EPA could suppress the proliferation of fibroblast like synoviocytes in vitro. We treated synoviocytes with 1 to 50 µM EPA and measured cell viabilities by the modified MTT assay. We sorted the number of them in sub G1 stage by fluorescence-activated cell sorting caliber. And we stained them by light green or Hoechst 33258, and investigate microscopic appearance. The cell viabilities were decreased at 30 µM, 40 µM, and 50 µM of EPA comparing to 0 µM of EPA. The half maximal concentration of synoviocytes inhibition was approximately 25 µM. At day 1 and day 3, cell number was also decreased at 50 µM EPA comparing to control. FACS caliber indicated the number of synoviocytes in sub G1 stage did not increase in each concentration of EPA. Hoechst staining indicated normal chromatin pattern and no change in a nuclear morphology both in EPA treated synoviocytes and in untreated synoviocytes. These findings suggest that EPA could suppress the proliferation of synoviocytes in vivo dose dependently and time dependently, however, the mechanism is not due to apoptosis

    Alterations of circulating endothelial cell and endothelial progenitor cell counts around the ovulation.

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    Context:Circulating endothelial cells (CECs) and progenitor cells (CEPs) have been intensively studied as a promising tool for treating ischemic diseases and monitoring cancer treatments, but how the menstrual cycle affects the variation in their counts remains unclear. Objective:The aims of the study were to determine the influence of the menstrual cycle on the number of CECs and CEPs and to investigate the association of their counts with circulating hormones and angiogenesis-associated factors. Design:CEP and CEC counts by flow cytometry and the CellSearch system and circulating factor levels were measured eight times during the menstrual cycle in 18 volunteers. The menstrual cycle was divided into six phases based on hormone concentrations. Results:CEP counts peaked in the periovulatory and middle luteal phases with a drop in the early luteal phase. CEC counts showed no significant variation. There were significant correlations between the CEP counts and the serum concentrations of estradiol (E2), LH, and granulocyte colony-stimulating factor (G-CSF) (P < 0.0001, P < 0.0001, and P = 0.01, respectively). The difference in CEP counts between two adjacent phases was significantly correlated with that in E2, LH, G-CSF, and serum vascular endothelial growth factor (P < 0.0001, P < 0.0001, P = 0.02, and P = 0.006, respectively). Conclusion:CEP counts peaked in the periovulatory and middle luteal phases, with a drop in the early luteal phase, and were correlated with serum E2, LH, and G-CSF concentrations. Consideration of the variation in CEP counts would be important for the clinical application of CEPs

    Feedback Control of the Arachidonate Cascade in Osteoblastic Cells by 15-deoxy-Δ12,14-Prostaglandin J2

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    15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and an anti-diabetic thiazolidinedione, troglitazone (TRO) are peroxisome proliferator-activated receptor (PPAR)-γ ligands, which regulate immuno-inflammatory reactions as well as adipocyte differentiation. We previously reported that 15d-PGJ2 can suppress interleukin (IL)-1β-induced prostaglandin E2 (PGE2) synthesis in synoviocytes of rheumatoid arthritis (RA). IL-1 also stimulates PGE2 synthesis in osteoblasts by regulation of cyclooxygenase (COX)-2 and regulates osteoclastic bone resorption in various diseases such as RA and osteoporosis. In this study, we investigated the feedback mechanism of the arachidonate cascade in mouse osteoblastic cells, MC3T3-E1 cells, which differentiate into mature osteoblasts. Treatment with 15d-PGJ2 led to a significant increase in IL-1α-induced COX-2 expression and PGE2 production in a dose dependent manner. The effect of 15d-PGJ2 was stronger than that of TRO. However, it did not affect the expression of COX-1. In addition, cell viability of MC3T3-E1 cells was not changed in the condition we established. This means that 15d-PGJ2 exerts a positive feedback regulation of the arachidonate cascade of PGE2 in osteoblastic cells. These results may provide important information about the pathogenesis and treatment of bone resorption in a variety of diseases such as RA and osteoporosis

    Detection and management of cardiomyopathy in female dystrophinopathy carriers

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    Regular health checkups for mothers of patients with Duchenne muscular dystrophy have been performed at National Hospital Organization Tokushima Hospital since 1994. Among 43 mothers participated in this study, 28 dystrophinopathy carriers were identified. Skeletal and cardiac muscle functions of these subjects were examined. High serum creatine kinase was found in 23 subjects (82.1%). Obvious muscle weakness was present in 5 (17.8%) and had progressed from 1994 to 2015. Cardiomyopathy was observed in 15 subjects (60.0%), including dilated cardiomyopathy-like damage that was more common in the left ventricular (LV) posterior wall. Late gadolinium enhancement on cardiac MRI was found in 5 of 6 subjects, suggesting fibrotic cardiac muscle. In speckle tracking echocardiography performed seven years later, global longitudinal strain was decreased in these subjects, indicating LV myocardial contractile abnormality. These results suggest that female dystrophinopathy carriers should receive regular checkups for detection and treatment of cardiomyopathy, even if they have no cardiac symptoms

    Practical "1-2-3-4-Day" Rule for Starting Direct Oral Anticoagulants After Ischemic Stroke With Atrial Fibrillation: Combined Hospital-Based Cohort Study

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    BACKGROUND: The "1-3-6-12-day rule" for starting direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation after acute ischemic stroke or transient ischemic attack recommends timings that may be later than used in clinical practice. We investigated more practical optimal timing of DOAC initiation according to stroke severity. METHODS: The combined data of prospective registries in Japan, Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-nonvalvular atrial fibrillation (September 2011 to March 2014) and RELAXED (February 2014 to April 2016) were used. Patients were divided into transient ischemic attack and 3 stroke subgroups by the National Institutes of Health Stroke Scale score: mild (0-7), moderate (8-15), and severe (≥16). The early treatment group was defined as patients starting DOACs earlier than the median initiation day in each subgroup. Outcomes included a composite of recurrent stroke or systemic embolism, ischemic stroke, and severe bleeding within 90 days. Six European prospective registries were used for validation. RESULTS: In the 1797 derivation cohort patients, DOACs were started at median 2 days after transient ischemic attack and 3, 4, and 5 days after mild, moderate, and severe strokes, respectively. Stroke or systemic embolism was less common in Early Group (n=785)-initiating DOACS within 1, 2, 3, and 4 days, respectively-than Late Group (n=1012) (1.9% versus 3.9%; adjusted hazard ratio, 0.50 [95% CI, 0.27-0.89]), as was ischemic stroke (1.7% versus 3.2%, 0.54 [0.27-0.999]). Major bleeding was similarly common in the 2 groups (0.8% versus 1.0%). On validation, both ischemic stroke (2.4% versus 2.2%) and intracranial hemorrhage (0.2% versus 0.6%) were similarly common in Early (n=547) and Late (n=1483) Groups defined using derivation data. CONCLUSIONS: In Japanese and European populations, early DOAC initiation within 1, 2, 3, or 4 days according to stroke severity seemed to be feasible to decrease the risk of recurrent stroke or systemic embolism and no increase in major bleeding. These findings support ongoing randomized trials to better establish the optimal timing of DOAC initiation

    Patients' acceptability and implementation outcomes of a case management approach to encourage participation in colorectal cancer screening for people with schizophrenia: a qualitative secondary analysis of a mixed-method randomised clinical trial

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    Objectives We examined the efficacy of case management (CM) interventions to encourage participation in colorectal cancer screening for patients with schizophrenia. This study aimed to clarify patients' acceptability of the intervention and the helpful components of the intervention. Simultaneously, the study aimed to determine the acceptability, appropriateness and feasibility of the intervention from the perspective of psychiatric care providers. Study design and setting This study was a secondary qualitative analysis of a mixed-method randomised controlled trial that evaluated the efficacy of the CM approach to encourage participation in cancer screening for people with schizophrenia. The intervention comprised education and patient navigation for colorectal cancer screening. Interviews were conducted with patients who received the intervention and staff from two psychiatric hospitals in Japan who delivered the intervention. Participants Of the 172 patients with schizophrenia who participated in the trial, 153 were included. In addition, three out of six providers were included. Data collection and analysis Using a structured interview, the case manager asked participants about patient acceptability and the helpful components of the intervention. Content analysis was conducted for the responses obtained, and the number of responses was tabulated by two researchers. For the interviews with the providers, opinions obtained from verbatim transcripts were extracted and summarised. Results Forty-three of the 56 patients perceived that the intervention was acceptable. For the intervention component, inperson counselling with an explanation of the screening process by psychiatric care providers was most frequently reported by the patients as helpful (48 of the 68 respondents). Psychiatric care providers evaluated the intervention as acceptable, appropriate and easy to understand and administer. However, providing the intervention to all patients simultaneously was considered difficult with the current human resources. Conclusions This study showed that the CM intervention was perceived as acceptable by patients and acceptable and appropriate by psychiatric care providers

    Randomised, multicentre prospective trial of transarterial chemoembolisation (TACE) plus sorafenib as compared with TACE alone in patients with hepatocellular carcinoma: TACTICS trial.

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    OBJECTIVE:This trial compared the efficacy and safety of transarterial chemoembolisation (TACE) plus sorafenib with TACE alone using a newly established TACE-specific endpoint and pre-treatment of sorafenib before initial TACE. DESIGN:Patients with unresectable hepatocellular carcinoma (HCC) were randomised to TACE plus sorafenib (n=80) or TACE alone (n=76). Patients in the combination group received sorafenib 400 mg once daily for 2-3 weeks before TACE, followed by 800 mg once daily during on-demand conventional TACE sessions until time to untreatable (unTACEable) progression (TTUP), defined as untreatable tumour progression, transient deterioration to Child-Pugh C or appearance of vascular invasion/extrahepatic spread. Co-primary endpoints were progression-free survival (PFS), which is not a conventional one but defined as TTUP, or time to any cause of death plus overall survival (OS). Multiplicity was adjusted by gatekeeping hierarchical testing. RESULTS:Median PFS was significantly longer in the TACE plus sorafenib than in the TACE alone group (25.2 vs 13.5 months; p=0.006). OS was not analysed because only 73.6% of OS events were reached. Median TTUP (26.7 vs 20.6 months; p=0.02) was also significantly longer in the TACE plus sorafenib group. OS at 1 year and 2 years in TACE plus sorafenib group and TACE alone group were 96.2% and 82.7% and 77.2% and 64.6%, respectively. There were no unexpected toxicities. CONCLUSION:TACE plus sorafenib significantly improved PFS over TACE alone in patients with unresectable HCC. Adverse events were consistent with those of previous TACE combination trials. TRIAL REGISTRATION NUMBER:NCT01217034
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