SLERT Regulates DDX21 Rings Associated with Pol I Transcription.

Dysregulated rRNA synthesis by RNA polymerase I (Pol I) is associated with uncontrolled cell proliferation. Here, we report a box H/ACA small nucleolar RNA (snoRNA)-ended long noncoding RNA (lncRNA) that enhances pre-rRNA transcription (SLERT). SLERT requires box H/ACA snoRNAs at both ends for its biogenesis and translocation to the nucleolus. Deletion of SLERT impairs pre-rRNA transcription and rRNA production, leading to decreased tumorigenesis. Mechanistically, SLERT interacts with DEAD-box RNA helicase DDX21 via a 143-nt non-snoRNA sequence. Super-resolution images reveal that DDX21 forms ring-shaped structures surrounding multiple Pol I complexes and suppresses pre-rRNA transcription. Binding by SLERT allosterically alters individual DDX21 molecules, loosens the DDX21 ring, and evicts DDX21 suppression on Pol I transcription. Together, our results reveal an important control of ribosome biogenesis by SLERT lncRNA and its regulatory role in DDX21 ring-shaped arrangements acting on Pol I complexes.

Nucleolar URB1 ensures 3' ETS rRNA removal to prevent exosome surveillance.

The nucleolus is the most prominent membraneless condensate in the nucleus. It comprises hundreds of proteins with distinct roles in the rapid transcription of ribosomal RNA (rRNA) and efficient processing within units comprising a fibrillar centre and a dense fibrillar component and ribosome assembly in a granular component1. The precise localization of most nucleolar proteins and whether their specific localization contributes to the radial flux of pre-rRNA processing have remained unknown owing to insufficient resolution in imaging studies2-5. Therefore, how these nucleolar proteins are functionally coordinated with stepwise pre-rRNA processing requires further investigation. Here we screened 200 candidate nucleolar proteins using high-resolution live-cell microscopy and identified 12 proteins that are enriched towards the periphery of the dense fibrillar component (PDFC). Among these proteins, unhealthy ribosome biogenesis 1 (URB1) is a static, nucleolar protein that ensures 3' end pre-rRNA anchoring and folding for U8 small nucleolar RNA recognition and the subsequent removal of the 3' external transcribed spacer (ETS) at the dense fibrillar component-PDFC boundary. URB1 depletion leads to a disrupted PDFC, uncontrolled pre-rRNA movement, altered pre-rRNA conformation and retention of the 3' ETS. These aberrant 3' ETS-attached pre-rRNA intermediates activate exosome-dependent nucleolar surveillance, resulting in decreased 28S rRNA production, head malformations in zebrafish and delayed embryonic development in mice. This study provides insight into functional sub-nucleolar organization and identifies a physiologically essential step in rRNA maturation that requires the static protein URB1 in the phase-separated nucleolus.

Nascent Pre-rRNA Sorting via Phase Separation Drives the Assembly of Dense Fibrillar Components in the Human Nucleolus.

Fibrillar centers (FCs) and dense fibrillar components (DFCs) are essential morphologically distinct sub-regions of mammalian cell nucleoli for rDNA transcription and pre-rRNA processing. Here, we report that a human nucleolus consists of several dozen FC/DFC units, each containing 2-3 transcriptionally active rDNAs at the FC/DFC border. Pre-rRNA processing factors, such as fibrillarin (FBL), form 18-24 clusters that further assemble into the DFC surrounding the FC. Mechanistically, the 5' end of nascent 47S pre-rRNA binds co-transcriptionally to the RNA-binding domain of FBL. FBL diffuses to the DFC, where local self-association via its glycine- and arginine-rich (GAR) domain forms phase-separated clusters to immobilize FBL-interacting pre-rRNA, thus promoting directional traffic of nascent pre-rRNA while facilitating pre-rRNA processing and DFC formation. These results unveil FC/DFC ultrastructures in nucleoli and suggest a conceptual framework for considering nascent RNA sorting using multivalent interactions of their binding proteins.

Dynamic Imaging of RNA in Living Cells by CRISPR-Cas13 Systems.

Visualizing the location and dynamics of RNAs in live cells is key to understanding their function. Here, we identify two endonuclease-deficient, single-component programmable RNA-guided and RNA-targeting Cas13 RNases (dCas13s) that allow robust real-time imaging and tracking of RNAs in live cells, even when using single 20- to 27-nt-long guide RNAs. Compared to the aptamer-based MS2-MCP strategy, an optimized dCas13 system is user friendly, does not require genetic manipulation, and achieves comparable RNA-labeling efficiency. We demonstrate that the dCas13 system is capable of labeling NEAT1, SatIII, MUC4, and GCN4 RNAs and allows the study of paraspeckle-associated NEAT1 dynamics. Applying orthogonal dCas13 proteins or combining dCas13 and MS2-MCP allows dual-color imaging of RNAs in single cells. Further combination of dCas13 and dCas9 systems allows simultaneous visualization of genomic DNA and RNA transcripts in living cells.

Advanced surface passivation for high-sensitivity studies of biomolecular condensates.

Biomolecular condensates are cellular compartments that concentrate biomolecules without an encapsulating membrane. In recent years, significant advances have been made in the understanding of condensates through biochemical reconstitution and microscopic detection of these structures. Quantitative visualization and biochemical assays of biomolecular condensates rely on surface passivation to minimize background and artifacts due to condensate adhesion. However, the challenge of undesired interactions between condensates and glass surfaces, which can alter material properties and impair observational accuracy, remains a critical hurdle. Here, we introduce an efficient, broadly applicable, and simple passivation method employing self-assembly of the surfactant Pluronic F127 (PF127). The method greatly reduces nonspecific binding across a range of condensates systems for both phase-separated droplets and biomolecules in dilute phase. Additionally, by integrating PF127 passivation with the Biotin-NeutrAvidin system, we achieve controlled multipoint attachment of condensates to surfaces. This not only preserves condensate properties but also facilitates long-time fluorescence recovery after photobleaching imaging and high-precision single-molecule analyses. Using this method, we have explored the dynamics of polySIM molecules within polySUMO/polySIM condensates at the single-molecule level. Our observations suggest a potential heterogeneity in the distribution of available polySIM-binding sites within the condensates.

Coordinated circRNA Biogenesis and Function with NF90/NF110 in Viral Infection.

Circular RNAs (circRNAs) generated via back-splicing are enhanced by flanking complementary sequences. Expression levels of circRNAs vary under different conditions, suggesting participation of protein factors in their biogenesis. Using genome-wide siRNA screening that targets all human unique genes and an efficient circRNA expression reporter, we identify double-stranded RNA-binding domain containing immune factors NF90/NF110 as key regulators in circRNA biogenesis. NF90/NF110 promote circRNA production in the nucleus by associating with intronic RNA pairs juxtaposing the circRNA-forming exon(s); they also interact with mature circRNAs in the cytoplasm. Upon viral infection, circRNA expression is decreased, in part owing to the nuclear export of NF90/NF110 to the cytoplasm. Meanwhile, NF90/NF110 released from circRNP complexes bind to viral mRNAs as part of their functions in antiviral immune response. Our results therefore implicate a coordinated regulation of circRNA biogenesis and function by NF90/NF110 in viral infection.

Emerging roles of liquid-liquid phase separation in liver innate immunity.

Biomolecular condensates formed by liquid-liquid phase separation (LLPS) have become an extensive mechanism of macromolecular metabolism and biochemical reactions in cells. Large molecules like proteins and nucleic acids will spontaneously aggregate and assemble into droplet-like structures driven by LLPS when the physical and chemical properties of cells are altered. LLPS provides a mature molecular platform for innate immune response, which tightly regulates key signaling in liver immune response spatially and physically, including DNA and RNA sensing pathways, inflammasome activation, and autophagy. Take this, LLPS plays a promoting or protecting role in a range of liver diseases, such as viral hepatitis, non-alcoholic fatty liver disease, liver fibrosis, hepatic ischemia-reperfusion injury, autoimmune liver disease, and liver cancer. This review systematically describes the whole landscape of LLPS in liver innate immunity. It will help us to guide a better-personalized approach to LLPS-targeted immunotherapy for liver diseases.

Unusual Processing Generates SPA LncRNAs that Sequester Multiple RNA Binding Proteins.

We identify a type of polycistronic transcript-derived long noncoding RNAs (lncRNAs) that are 5' small nucleolar RNA (snoRNA) capped and 3' polyadenylated (SPAs). SPA processing is associated with nascent mRNA 3' processing and kinetic competition between XRN2 trimming and Pol II elongation. Following cleavage/polyadenylation of its upstream gene, the downstream uncapped pre-SPA is trimmed by XRN2 until this exonuclease reaches the co-transcriptionally assembled snoRNP. This snoRNP complex prevents further degradation, generates a snoRNA 5' end, and allows continuous Pol II elongation. The imprinted 15q11-q13 encodes two SPAs that are deleted in Prader-Willi syndrome (PWS) patients. These lncRNAs form a nuclear accumulation that is enriched in RNA binding proteins (RBPs) including TDP43, RBFOX2, and hnRNP M. Generation of a human PWS cellular model by depleting these lncRNAs results in altered patterns of RBPs binding and alternative splicing. Together, these results expand the diversity of lncRNAs and provide additional insights into PWS pathogenesis.

Construction and evaluation of short-term and long-term mortality risk prediction model for patients with sepsis based on MIMIC-IV database. / 基于MIMIC-IVæž„å»ºåŠè¯„ä¼°è„“æ¯’ç—‡æ‚£è€ è¿‘æœŸå’Œè¿œæœŸæ­»äº¡é£Žé™©é¢„æµ‹æ¨¡åž‹.

OBJECTIVES: Given the high incidence and mortality rate of sepsis, early identification of high-risk patients and timely intervention are crucial. However, existing mortality risk prediction models still have shortcomings in terms of operation, applicability, and evaluation on long-term prognosis. This study aims to investigate the risk factors for death in patients with sepsis, and to construct the prediction model of short-term and long-term mortality risk. METHODS: Patients meeting sepsis 3.0 diagnostic criteria were selected from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and randomly divided into a modeling group and a validation group at a ratio of 7꞉3. Baseline data of patients were analyzed. Univariate Cox regression analysis and full subset regression were used to determine the risk factors of death in patients with sepsis and to screen out the variables to construct the prediction model. The time-dependent area under the curve (AUC), calibration curve, and decision curve were used to evaluate the differentiation, calibration, and clinical practicability of the model. RESULTS: A total of 14 240 patients with sepsis were included in our study. The 28-day and 1-year mortality were 21.45% (3 054 cases) and 36.50% (5 198 cases), respectively. Advanced age, female, high sepsis-related organ failure assessment (SOFA) score, high simplified acute physiology score II (SAPS II), rapid heart rate, rapid respiratory rate, septic shock, congestive heart failure, chronic obstructive pulmonary disease, liver disease, kidney disease, diabetes, malignant tumor, high white blood cell count (WBC), long prothrombin time (PT), and high serum creatinine (SCr) levels were all risk factors for sepsis death (all P<0.05). Eight variables, including PT, respiratory rate, body temperature, malignant tumor, liver disease, septic shock, SAPS II, and age were used to construct the model. The AUCs for 28-day and 1-year survival were 0.717 (95% CI 0.710 to 0.724) and 0.716 (95% CI 0.707 to 0.725), respectively. The calibration curve and decision curve showed that the model had good calibration degree and clinical application value. CONCLUSIONS: The short-term and long-term mortality risk prediction models of patients with sepsis based on the MIMIC-IV database have good recognition ability and certain clinical reference significance for prognostic risk assessment and intervention treatment of patients.

Manual correction of genome annotation improved alternative splicing identification of Artemisia annua.

Gene annotation is essential for genome-based studies. However, algorithm-based genome annotation is difficult to fully and correctly reveal genomic information, especially for species with complex genomes. Artemisia annua L. is the only commercial resource of artemisinin production though the content of artemisinin is still to be improved. Genome-based genetic modification and breeding are useful strategies to boost artemisinin content and therefore, ensure the supply of artemisinin and reduce costs, but better gene annotation is urgently needed. In this study, we manually corrected the newly released genome annotation of A. annua using second- and third-generation transcriptome data. We found that incorrect gene information may lead to differences in structural, functional, and expression levels compared to the original expectations. We also identified alternative splicing events and found that genome annotation information impacted identifying alternative splicing genes. We further demonstrated that genome annotation information and alternative splicing could affect gene expression estimation and gene function prediction. Finally, we provided a valuable version of A. annua genome annotation and demonstrated the importance of gene annotation in future research.

An optimized fixation method containing glyoxal and paraformaldehyde for imaging nuclear bodies.

The mammalian cell nucleus contains different types of membrane-less nuclear bodies (NBs) consisting of proteins and RNAs. Microscopic imaging has been widely applied to study the organization and structure of NBs. However, current fixation methods are not optimized for such imaging: When a fixation method is chosen to maximize the quality of the RNA fluorescence in situ hybridization (FISH), it often limits the labeling efficiency of proteins or affects the ultrastructure of NBs. Here, we report that addition of glyoxal (GO) into the classical paraformaldehyde (PFA) fixation step not only improves FISH signals for RNAs in NBs via augmented permeability of the fixed nucleus and enhanced accessibility of probes, but also largely preserves protein fluorescent signals during fixation and immunostaining. We also show that GO/PFA fixation enables the covisualization of different types of nuclear bodies with minimal impact on their ultrastructures under super-resolution microscopy.

Increased suicidal erythrocyte death in patients with hepatitis B-related acute-on-chronic liver failure.

Anemia is a common complication of hepatitis B-related acute-on-chronic liver failure (HB-ACLF). Eryptosis, a suicidal erythrocyte death characterized by phosphatidylserine (PS) externalization and red blood cell-derived microparticle (RMP) generation, decreases erythrocyte lifespan. Herein, we investigated whether enhanced eryptosis is involved in the anemia pathophysiology associated with HB-ACLF. PS exposure, cell volume, cytosolic Ca2+, and reactive oxygen species (ROS) production were determined using flow cytometry. RMPs were extracted using a polyethylene glycol (PEG)-based method. We found that hemoglobin (Hb) and hematocrit (Hct) were significantly lower in patients with HB-ACLF than in healthy controls (HC), patients with chronic hepatitis B (CHB), and patients with cirrhosis. The direct antiglobulin test positive rate was 75.9% in patients with HB-ACLF while its intensity was associated with anemia. The ratio of abnormal erythrocytes was higher in patients with HB-ACLF than in HC, CHB, and cirrhosis. The percentage of PS-exposed erythrocytes was higher in patients with HB-ACLF (2.07 ± 0.11%) compared with HC (0.37 ± 0.05%), CHB (0.38 ± 0.03%), and cirrhosis (0.38 ± 0.04%). The cytosolic Ca2+ and ROS abundance were also higher in patients with HB-ACLF compared with HC, patients with CHB, and patients with cirrhosis, and were inversely correlated with the anemia in patients with HB-ACLF. PS exposure of erythrocytes collected from HC was significantly pronounced following incubation in plasma from patients with HB-ACLF compared with incubation in plasma from HC. The protein concentration and RMPs size significantly increased in patients with HB-ACLF compared with HC. Thus, the anemia in patients with HB-ACLF is associated with increased eryptosis, which is partially triggered by increased cytosolic Ca2+ and oxidative stress.NEW & NOTEWORTHY Acute chronic liver failure (ACLF) is a critical syndrome characterized by multiple organ failures and high short-term mortality. A common complication of HB-ACLF is anemia, however, the mechanism of anemia in HB-ACLF remains to be elucidated. We confirm that the accelerated eryptosis is involved in the pathophysiology of anemia associated with HB-ACLF, which progressively aggravates the clinical outcome. Our study illustrates the mechanism regarding the anemia pathogenesis of HB-ACLF, which may be utilized further toward therapeutic ends.

U-shaped relationship between platelet-lymphocyte ratio and postoperative in-hospital mortality in patients with type A acute aortic dissection.

BACKGROUND: The platelet-lymphocyte ratio (PLR), a novel inflammatory marker, is generally associated with increased in-hospital mortality risk. We aimed to investigate the association between PLR and postoperative in-hospital mortality risk in patients with type A acute aortic dissection (AAAD). METHODS: Patients (n = 270) who underwent emergency surgery for AAAD at Xiangya Hospital of Central South University between January 2014 and May 2019 were divided into three PLR-based tertiles. We used multiple regression analyses to evaluate the independent effect of PLR on in-hospital mortality, and smooth curve fitting and a segmented regression model with adjustment of confounding factors to analyze the threshold effect between PLR and in-hospital mortality risk. RESULTS: The overall postoperative in-hospital mortality was 13.33%. After adjusting for confounders, in-hospital mortality risk in the medium PLR tertile was the lowest (Odds ratio [OR] = 0.20, 95% confidence interval [CI] = 0.06-0.66). We observed a U-shaped relationship between PLR and in-hospital mortality risk after smoothing spline fitting was applied. When PLR < 108, the in-hospital mortality risk increased by 10% per unit decrease in PLR (OR = 0.90, P = 0.001). When the PLR was between 108 and 188, the mortality risk was the lowest (OR = 1.02, P = 0.288). When PLR > 188, the in-hospital mortality risk increased by 6% per unit increase in PLR (OR = 1.06, P = 0.045). CONCLUSIONS: There was a U-shaped relationship between PLR and in-hospital mortality in patients with AAAD, with an optimal PLR range for the lowest in-hospital mortality risk of 108-188. PLR may be a useful preoperative prognostic tool for predicting in-hospital mortality risk in patients with AAAD and can ensure risk stratification and early treatment initiation.

Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China.

Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.

Advanced Surface Passivation for High-Sensitivity Studies of Biomolecular Condensates.

Biomolecular condensates are cellular compartments that concentrate biomolecules without an encapsulating membrane. In recent years, significant advances have been made in the understanding of condensates through biochemical reconstitution and microscopic detection of these structures. Quantitative visualization and biochemical assays of biomolecular condensates rely on surface passivation to minimize background and artifacts due to condensate adhesion. However, the challenge of undesired interactions between condensates and glass surfaces, which can alter material properties and impair observational accuracy, remains a critical hurdle. Here, we introduce an efficient, generically applicable, and simple passivation method employing self-assembly of the surfactant Pluronic F127 (PF127). The method greatly reduces nonspecific binding across a range of condensates systems for both phase-separated droplets and biomolecules in dilute phase. Additionally, by integrating PF127 passivation with the Biotin-NeutrAvidin system, we achieve controlled multi-point attachment of condensates to surfaces. This not only preserves condensate properties but also facilitates long-time FRAP imaging and high-precision single-molecule analyses. Using this method, we have explored the dynamics of polySIM molecules within polySUMO/polySIM condensates at the single-molecule level. Our observations suggest a potential heterogeneity in the distribution of available polySIM-binding sites within the condensates.

Efficacy of fresh frozen plasma transfusion in decompensated cirrhosis patients with coagulopathy admitted to ICU: a retrospective cohort study from MIMIC-IV database.

We aimed to explore the association between FFP transfusion and outcomes of DC patients with significant coagulopathy. A total of 693 DC patients with significant coagulopathy were analyzed with 233 patients per group after propensity score matching (PSM). Patients who received FFP transfusion were matched with those receiving conventional therapy via PSM. Regression analysis showed FFP transfusion had no benefit in 30-day (HR: 1.08, 95% CI 0.83-1.4), 90-day (HR: 1.03, 95% CI 0.80-1.31) and in-hospital(HR: 1.30, 95% CI 0.90-1.89) mortality, associated with increased risk of liver failure (OR: 3.00, 95% CI 1.78-5.07), kidney failure (OR: 1.90, 95% CI 1.13-3.18), coagulation failure (OR: 2.55, 95% CI 1.52-4.27), respiratory failure (OR: 1.76, 95% CI 1.15-2.69), and circulatory failure (OR: 2.15, 95% CI 1.27-3.64), and even associated with prolonged the LOS ICU (ß: 2.61, 95% CI 1.59-3.62) and LOS hospital (ß: 6.59, 95% CI 2.62-10.57). In sensitivity analysis, multivariate analysis (HR: 1.09, 95%CI 0.86, 1.38), IPTW (HR: 1.11, 95%CI 0.95-1.29) and CAPS (HR: 1.09, 95% CI 0.86-1.38) showed FFP transfusion had no beneficial effect on the 30-day mortality. Smooth curve fitting demonstrated the risk of liver failure, kidney failure and circulatory failure increased by 3%, 2% and 2% respectively, for each 1 ml/kg increase in FFP transfusion. We found there was no significant difference of CLIF-SOFA and MELD score between the two group on day 0, 3, 7, 14. Compared with the conventional group, INR, APTT, and TBIL in the FFP transfusion group significantly increased, while PaO2/FiO2 significantly decreased within 14 days. In conclusion, FFP transfusion had no beneficial effect on the 30-day, 90-day, in-hospital mortality, was associated with prolonged the LOS ICU and LOS hospital, and the increased risk of liver failure, kidney failure, coagulation failure, respiratory failure and circulatory failure events. However, large, multi-center, randomized controlled trials, prospective cohort studies and external validation are still needed to verify the efficacy of FFP transfusion in the future.

[Study on human umbilical cord mesenchymal stem cells transplantation in treatment of stress urinary incontinence in rats].

OBJECTIVE: To investigate the feasibility and effectiveness of human umbilical cord mesenchymal stem cells (HUCMSC) transplantation in the treatment of female stress urinary incontinence (SUI) in rats. METHODS: The 14 female SD rats of SUI model were established by vaginal balloon dilation after birth and maintain this status for four hours bilateral ovariectomy were performed after two weeks and were routinely reared for two months, then 12 SUI rat model were made. Two months later, transfected with plasmid pEGFP-N1 of HUCMSC were injected into the region surrounding the urinary tract matched with saline injection as control group. To get genitourinary tissue after testing urodynamic indicators, and observe the pathological changes of the bladder, urethra and the surrounding tissue; fluorescent cell of the experimental groups specimens were observed by fluorescence microscope. RESULTS: The leak point pressure(LPP) was (23.8 ± 4.2) mm Hg(1 mm Hg = 0.133 kPa) of the SUI rats. Transplanting mesenchymal stem cells of SUI rats, the positive rate of sneeze test was 1/6 in SUI group and 5/6 in control group, which reached statistical significance (P < 0.05); LPP was (30.6 ± 2.8) mm Hg in SUI group and (21.4 ± 7.0) mm Hg in control group, which reached statistical significance (P < 0.05) .In SUI rate model, connective tissue content were increased in urethra and the surrounding tissue and more fluorescent cell were observed. CONCLUSIONS: A rat model of female SUI was established successfully through postpartum vaginal balloon dilation and bilateral ovariectomy. MSC can be survived and proliferated in the urethral and the surrounding tissue of injured rats, and improve the urodynamic indicators and the positive rate of sneeze test. Morphology shows renovation of the support structures around the urethra.

The effects of plasma to red blood cells transfusion ratio on in-hospital mortality in patients with acute type A aortic dissection.

Background: Blood transfusion is a frequent and necessary practice in acute type A aortic dissection (AAAD) patients, but the effect of plasma/red blood cells (RBCs) ratio on mortality remains unclear. The aim of this study is to investigate the association between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD. Methods: Patients were admitted to Xiangya Hospital of Central South University from January 1, 2016 to December 31, 2021. Clinical parameters were recorded. Multivariate Cox regression model was used to analyze the association between transfusion and in-hospital mortality. We used the smooth curve fitting and segmented regression model to assess the threshold effect between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD. Results: The volumes of RBCs [14.00 (10.12-20.50) unit] and plasma [19.25 (14.72-28.15) unit] transfused in non-survivors were significantly higher than in survivors [RBCs: 8.00 (5.50-12.00) unit]; plasma: [10.35 (6.50-15.22) unit]. Multivariate Cox regression analysis showed plasma transfusion was an independent risk factor of in-hospital mortality. Adjusted HR was 1.03 (95% CI: 0.96-1.11) for RBCs transfusion and 1.08 (95% CI: 1.03-1.13) for plasma transfusion. In the spline smoothing plot, mortality risk increased with plasma/RBCs transfusion ratio leveling up to the turning point 1. Optimal plasma/RBCs transfusion ratio with least mortality risk was 1. When the plasma/RBCs ratio was <1 (adjusted HR per 0.1 ratio: 0.28, 95% CI per 0.1 ratio: 0.17-0.45), mortality risk decreased with the increase of ratio. When the plasma/RBCs ratio was 1-1.5 (adjusted HR per 0.1 ratio: 2.73, 95% CI per 0.1 ratio:1.13-6.62), mortality risk increased rapidly with the increase of ratio. When the plasma/RBCs ratio was >1.5 (adjusted HR per 0.1 ratio: 1.09, 95% CI per 0.1 ratio:0.97-1.23), mortality risk tended to reach saturation, and increased non-significantly with the increase of ratio. Conclusion: A 1:1 plasma/RBCs ratio was associated with the lowest mortality in the patients with AAAD. And non-linear relationship existed between plasma/RBCs ratio and mortality.

U-SHAPED ASSOCIATION BETWEEN SERUM CALCIUM LEVELS AND 28-DAY MORTALITY IN PATIENTS WITH SEPSIS: A RETROSPECTIVE ANALYSIS OF THE MIMIC-III DATABASE.

ABSTRACT: Background: Serum calcium levels disorder have been reported to be associated with poor prognosis in different diseases. Studies on the association between serum calcium and outcomes of septic patients remained limited. The aim of this study is to investigate the association between serum calcium and 28-day mortality in septic patients. Method: Patients diagnosed with sepsis in the Medical Information Mart for Intensive Care III database were included. Patients were divided into five groups according to the quintiles of serum calcium levels, and their baseline characteristics were compared. Multivariate Cox regression models were used to assess the association between serum calcium and 28-day mortality. Smooth curve fitting and segmented regression models were used to visualize the association between serum calcium levels and 28-day mortality risk. The 28-day survival probability between five groups was analyzed using Kaplan-Meier curves. Results: A total of 3,016 patients with sepsis were enrolled, and the 28-day mortality rate was 35.64%. After adjusting for confounders, compared with the reference quintile (Q4: 9.00-9.50), the lowest serum calcium level quintile (Q1: 5.70-8.20) was independently associated with an increased risk of 28-day mortality (hazard ratio [HR], 2.12; 95% CI, 1.76-2.56). Smooth spline fitting revealed a U-shaped association between serum calcium and 28-day mortality. When serum calcium was <9.0 mg/dL, 28-day mortality risk increased by 58% per unit decrease in serum calcium (HR, 0.42; 95% CI, 0.37-0.48). When serum calcium was >9.0 mg/dL, the 28-day mortality risk increased by 12% per unit increase in serum calcium (HR, 1.12; 95% CI, 1.04-1.20). Conclusion: A U-shaped association was observed between serum calcium levels and 28-day mortality in septic patients. Lower or higher serum calcium levels were associated with increased risk of 28-day mortality in septic patients.

The therapeutic efficacy of plasmapheresis for sepsis with multiple organ failure: a propensity score-matched analysis based on the MIMIC-IV database.

BACKGROUND: Despite advancements in sepsis treatment, mortality remains high. Plasmapheresis (PE) targeting multiple pathways simultaneously appears to be a potential treatment option, but evidence is insufficient. We aimed to investigate the efficacy of PE for sepsis with multiple organ failure (MOF). METHOD: Septic patients with MOF were identified from the Medical Information Mart for Intensive Care IV database. Patients who received PE were matched with those receiving conventional therapy via propensity score matching (PSM). Regression analyses evaluated the association between PE and outcomes. The Kaplan-Meier (KM) method was utilized to analyze the survival probability. The generalized additive mixed model investigated early indexes changes' association with treatment modalities and 28-day mortality. RESULTS: 906 septic patients with MOF were enrolled. After PSM, PE and conventional groups consisted of 60 cases each. PE was associated with a reduced risk of 28-day mortality (hazard ratio [HR]: 0.50, 95% confidence interval [CI]: 0.27-0.94), 1-year mortality (HR: 0.44, 95%CI: 0.26-0.74), and in-hospital mortality (HR: 0.38, 95%CI: 0.20-0.71). KM curves demonstrated significant differences in survival probability between groups. Compared with the conventional group, the sequential organ failure assessment, norepinephrine dosage, prothrombin time, actate dehydrogenase, total bilirubin, white blood cells, and immature granulocytes in the PE group significantly decreased over time, while platelets, red blood cells, and hemoglobin significantly increased over time. CONCLUSIONS: Plasmapheresis demonstrated an association with reduced risks of 28-day, in-hospital and 1-year mortality in septic patients with MOF. Moreover, plasmapheresis might exhibit the potential to improve outcomes by improving organ function, hemodynamics and restoring several indicators such as coagulation, anemia, and inflammation.