Febrile infants risk score at triage (FIRST) for the early identification of serious bacterial infections.

We aimed to derive the Febrile Infants Risk Score at Triage (FIRST) to quantify risk for serious bacterial infections (SBIs), defined as bacteremia, meningitis and urinary tract infections. We performed a prospective observational study on febrile infants < 3 months old at a tertiary hospital in Singapore between 2018 and 2021. We utilized machine learning and logistic regression to derive 2 models: FIRST, based on patient demographics, vital signs and history, and FIRST + , adding laboratory results to the same variables. SBIs were diagnosed in 224/1002 (22.4%) infants. Among 994 children with complete data, age (adjusted odds ratio [aOR] 1.01 95%CI 1.01-1.02, p < 0.001), high temperature (aOR 2.22 95%CI 1.69-2.91, p < 0.001), male sex (aOR 2.62 95%CI 1.86-3.70, p < 0.001) and fever of ≥ 2 days (aOR 1.79 95%CI 1.18-2.74, p = 0.007) were independently associated with SBIs. For FIRST + , abnormal urine leukocyte esterase (aOR 16.46 95%CI 10.00-27.11, p < 0.001) and procalcitonin (aOR 1.05 95%CI 1.01-1.09, p = 0.009) were further identified. A FIRST + threshold of ≥ 15% predicted risk had a sensitivity of 81.8% (95%CI 70.5-91.0%) and specificity of 65.6% (95%CI 57.8-72.7%). In the testing dataset, FIRST + had an area under receiver operating characteristic curve of 0.87 (95%CI 0.81-0.94). These scores can potentially guide triage and prioritization of febrile infants.

Adding heart rate n-variability (HRnV) to clinical assessment potentially improves prediction of serious bacterial infections in young febrile infants at the emergency department: a prospective observational study.

Background: We aim to investigate the utility of heart rate variability (HRV) and heart rate n-variability (HRnV) in addition to vital signs and blood biomarkers, among febrile young infants at risk of serious bacterial infections (SBIs). Methods: We performed a prospective observational study between December 2017 and November 2021 in a tertiary paediatric emergency department (ED). We included febrile infants <90 days old with a temperature ≥38 ℃. We obtained HRV and HRnV parameters via a single lead electrocardiogram. HRV measures beat-to-beat (R-R) oscillation and reflects autonomic nervous system (ANS) regulation. HRnV includes overlapping and non-overlapping R-R intervals and provides additional physiological information. We defined SBIs as meningitis, bacteraemia and urinary tract infections (UTIs). We performed area under curve (AUC) analysis to assess predictive performance. Results: We recruited 330 and analysed 312 infants. The median age was 35.5 days (interquartile range 13.0-61.0); 74/312 infants (23.7%) had SBIs with the most common being UTIs (66/72, 91.7%); 2 infants had co-infections. No patients died and 32/312 (10.3%) received fluid resuscitation. Adding HRV and HRnV to demographics and vital signs at ED triage successively improved the AUC from 0.765 [95% confidence interval (CI): 0.705-0.825] to 0.776 (95% CI: 0.718-0.835) and 0.807 (95% CI: 0.752-0.861) respectively. The final model including demographics, vital signs, HRV, HRnV and blood biomarkers had an AUC of 0.874 (95% CI: 0.828-0.921). Conclusions: Addition of HRV and HRnV to current assessment tools improved the prediction of SBIs among febrile infants at ED triage. We intend to validate our findings and translate them into tools for clinical care in the ED.

YM155 inhibits neuroblastoma growth through degradation of MYCN: A new role as a USP7 inhibitor.

Amplification of the MYCN gene (MNA) is observed in approximately 25 to 35% of neuroblastoma patients, and is a well-recognized marker of tumor aggressiveness and poor outcome. Targeting MYCN is a novel therapy strategy to induce tumor regression. Here, we discovered that a BIRC5/Survivin inhibitor, YM155, specifically inhibits MNA neuroblastoma cell growth in vitro. We found that YM155 promotes MYCN degradation in MNA cells. Further, we found that YM155 inhibits USP7 deubiquitinase activity in vitro, using Ub-aminomethylcoumarin (Ub-AMC) as substrate. Results from in vivo studies further demonstrated that YM155 significantly inhibited the tumor growth in MNA neuroblastoma xenograft model. Our data support a novel mechanism of action of YM155 in inhibition of growth of cancer cells through inducing MYCN degradation by inibition of activity of deubiquitinase like USP7.

Preparation, characteristic and anti-inflammatory effect of selenium nanoparticle-enriched probiotic strain Enterococcus durans A8-1.

BACKGROUND: Elemental selenium, a new type of selenium supplement, can be biosynthesized via microorganisms. This study is to characterize a patent probiotic bacteria Enterococcus durans A8-1, capable of reducing selenite (Se6+ or Se4+) to elemental selenium (Se0) with the formation of Se nanoparticles (SeNPs). METHODS: The selenium nanoparticles synthesized from A8-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron energy (XPS). The Caco2 cells were used to investigate the effects of Se-enriched A8-1 on the viability, membrane integrity, and the regulation of cellular inflammation through MTT and ELISA assays. The selenium-enriched metabolic function of A8-1 was analyzed by transcriptome sequencing. RESULTS: E. durans A8-1 has the ability to synthesize intracellular SeNPs that are incubated with 60 mg/L sodium selenite for 18 h at 37 °C with 7 % inoculum under aerobic conditions. The selenium-enriched transformation rate increased to 43.46 %. After selenium enrichment, there were no significant morphological changes in E. durans A8-1 cells. The cells also exhibited no cytotoxicity when incubated with Caco-2 cells, and increased cellular proliferation. Furthermore, Se-enriched A8-1 cells antagonize the adhesion of S. typhimurium ATCC14028 onto the surface of Caco-2 cells protecting cell membrane integrity and was assessed by measuring LDH and AKP activities (P <0.001, P <0.001). Moreover, Se-enriched A8-1 could protect Caco-2 cells from inflammation induced by lipopolysaccharide and help the cells alleviate the inflammation through the reduced expression of cytokine IL-8 (P = 0.0012, P <0.001) and TNF-α (P <0.001, P <0.001). Based on transcriptome sequencing in Se-enriched E. durans A8-1 cells, there were 485 up-regulated genes and 322 down-regulated genes (Padj < 0.05). There were 19 predicted up-regulated genes that are highly related to the potential selenium metabolism pathway, which focuses on the transportation of Na2SeO3 by membrane proteins, and gradually reduces Na2SeO3 to elemental selenium aggregates that are deposited onto the membrane surface via the intracellular redox response. CONCLUSION: E. durans A8-1 could convert extracellular selenite into intracellular biological SeNPs via redox pathway with strong selenium-rich metabolism, and its biological SeNPs have anti-inflammatory properties, which have the potential for the development of composite selenium nanomaterials and can be further studied for the function of SeNPs with potential applications.

[Effects of increasing CO2 concentration and water deficit on photosynthetic performance and water use efficiency of typical green manure plants]. / CO2æµ“åº¦å¢žåŠ å’Œæ°´åˆ†äºç¼ºå¯¹å ¸åž‹ç»¿è‚¥æ¤ç‰©å ‰åˆæ€§èƒ½åŠæ°´åˆ†åˆ©ç”¨æ•ˆçŽ‡çš„å½±å“.

Exploring the impacts of CO2 and soil water availability on the photosynthetic performance and water use efficiency of three green manure plants could provide theoretical basis for the adaptive management of grassland ecosystems under future climate change. An experiment was conducted in an artificial climate chamber with precisely controled CO2 concentrations of 400 (natural atmospheric) and 800 µmol·mol-1 (doubled), and four water treatments, 80% field water holding capacity (FC) (full irrigation control group), 55%-60% FC (mild water deficit), 35%-40% FC (moderate water deficit), <35% FC (severe water deficit) to investigate the impacts of increasing CO2 concentration and water deficit on chlorophyll content, gas exchange variables, and water use efficiency (WUE) of oilseed rape (Brassica napus), white clover (Trifolium repens), and alfalfa (Medicago sativa). The results showed that under the same CO2 concentration, when soil moisture was less than 40% FC, the chlorophyll content and gas exchange parameters of three plants were significantly decreased. The treatment of 55%-60% FC did not alter the total chlorophyll content of three species, but reduced the photosynthetic rate (Pn) and transpiration rate (Tr) of white clover and alfalfa by 6%-25% and did not affect their WUE. Compared with atmospheric CO2 concentration, the doubled CO2 concentration significantly decreased the Pn of oilseed rape by 21.5% under the full irrigation treatment, increased the Pn of three species under mild water deficit, increased the Pn of oilseed rape and alfalfa under moderate water deficit, but only improved the Pn of alfalfa under severe water deficit. The doubled CO2 concentration significantly increased WUE of white clover and alfalfa under all water deficit conditions, but only increased WUE of oilseed rape under mild water deficit. Increasing CO2 concentration and water deficit significantly interacted to affect Pn of three species and the WUE of oilseed rape. In summary, the three species differed in their responses to doubled atmospheric CO2 concentration and different levels of water deficit. Our results suggested that elevated CO2 concentration could improve the adverse effects of mild water deficit on photosynthetic performance and WUE of three species, but only improve the photosynthetic performance of alfalfa under severe water deficit.

In vitro biocompatiability and mechanical properties of bone adhesive tape composite based on poly(butyl fumarate)/poly(propylene fumarate)-diacrylate networks.

Polyfumarate has been considered as injectable and biodegradable bone cement. However, its mechanical and degradation properties are particularly important. Therefore, the current study aimed to develop the properties by compositing poly (butyl fumarate)-based networks with hydroxyapatite nano-powders. In this regard, the poly (butyl fumarate) (PBF) matrix composite was compared with different components by evaluating their composition, mechanical properties, hydrophilicity, and biodegradability. Furthermore, their bioactivity in the phosphate-buffered saline (PBS) and, via applying mouse embryo osteoblast precursor cells (MC3T3-E1), their cell interaction, including adhesion, proliferation, and in vitro cytotoxicity assay, were assessed. The addition of hydroxyapatite improved the mechanical strength and modulus of PBF matrix composite. The composite reinforced with 3 wt% hydroxyapatite showed a higher lap-shear strength (1.68 MPa) and bonding strength (4.30 MPa), a maximum compression strength at fracture (95.18 MPa), modulus (925.29 MPa), and compression strength at yield (31.43 MPa), respectively. Also, hydrophilicity and in vitro degradation of the composite were enhanced in the presence of hydroxyapatite. In this condition, after a period of immersion (52 weeks) in PBS, the weight loss rate, and degradation rate of the composite increased. The composite proliferation, adhesion, and toxicity of MC3T3-E1 cells improved in comparison to the PBF matrix composite. Accordingly, controllable strength and degradation of the composite, along with its proven biocompatibility, make the composite a candidate for the treatment of comminuted fractures.

Water Deficit Modulates the CO2 Fertilization Effect on Plant Gas Exchange and Leaf-Level Water Use Efficiency: A Meta-Analysis.

Elevated atmospheric CO2 concentrations ([eCO2]) and soil water deficits significantly influence gas exchange in plant leaves, affecting the carbon-water cycle in terrestrial ecosystems. However, it remains unclear how the soil water deficit modulates the plant CO2 fertilization effect, especially for gas exchange and leaf-level water use efficiency (WUE). Here, we synthesized a comprehensive dataset including 554 observations from 54 individual studies and quantified the responses for leaf gas exchange induced by e[CO2] under water deficit. Moreover, we investigated the contribution of plant net photosynthesis rate (P n ) and transpiration rates (T r) toward WUE in water deficit conditions and e[CO2] using graphical vector analysis (GVA). In summary, e[CO2] significantly increased P n and WUE by 11.9 and 29.3% under well-watered conditions, respectively, whereas the interaction of water deficit and e[CO2] slightly decreased P n by 8.3%. Plants grown under light in an open environment were stimulated to a greater degree compared with plants grown under a lamp in a closed environment. Meanwhile, water deficit reduced P n by 40.5 and 37.8%, while increasing WUE by 24.5 and 21.5% under ambient CO2 concentration (a[CO2]) and e[CO2], respectively. The e[CO2]-induced stimulation of WUE was attributed to the common effect of P n and T r, whereas a water deficit induced increase in WUE was linked to the decrease in T r. These results suggested that water deficit lowered the stimulation of e[CO2] induced in plants. Therefore, fumigation conditions that closely mimic field conditions and multi-factorial experiments such as water availability are needed to predict the response of plants to future climate change.

Heart rate n-variability (HRnV) measures for prediction of mortality in sepsis patients presenting at the emergency department.

Sepsis is a potentially life-threatening condition that requires prompt recognition and treatment. Recently, heart rate variability (HRV), a measure of the cardiac autonomic regulation derived from short electrocardiogram tracings, has been found to correlate with sepsis mortality. This paper presents using novel heart rate n-variability (HRnV) measures for sepsis mortality risk prediction and comparing against current mortality prediction scores. This study was a retrospective cohort study on patients presenting to the emergency department of a tertiary hospital in Singapore between September 2014 to April 2017. Patients were included if they were above 21 years old and were suspected of having sepsis by their attending physician. The primary outcome was 30-day in-hospital mortality. Stepwise multivariable logistic regression model was built to predict the outcome, and the results based on 10-fold cross-validation were presented using receiver operating curve analysis. The final predictive model comprised 21 variables, including four vital signs, two HRV parameters, and 15 HRnV parameters. The area under the curve of the model was 0.77 (95% confidence interval 0.70-0.84), outperforming several established clinical scores. The HRnV measures may have the potential to allow for a rapid, objective, and accurate means of patient risk stratification for sepsis severity and mortality. Our exploration of the use of wealthy inherent information obtained from novel HRnV measures could also create a new perspective for data scientists to develop innovative approaches for ECG analysis and risk monitoring.

A Novel Fast-Setting Strontium-Containing Hydroxyapatite Bone Cement With a Simple Binary Powder System.

In recent years, strontium-substituted calcium phosphate bone cement (Sr-CPC) has attracted more and more attentions in the field of bone tissue repair due to its comprehensive advantages of both traditional CPC and Sr ions. In this study, a crucial Sr-containing α-Ca3 - x Sr x (PO4)2 salt has been synthesized using a simplified one-step method at lower synthesis temperature. A novel Sr-CPC has been developed based on the simple binary Sr-containing α-Ca3 - x Sr x (PO4)2/Ca4(PO4)2O cement powder. The physicochemical properties and hydration mechanism of this Sr-CPC at various Sr contents were intensively investigated. The setting product of this Sr-CPC after a set for 72 h is a single-phase Sr-containing hydroxyapatite, and its compressive strength slightly decreased and its setting time extended with the increase of Sr content. The hydration process included the initial formation of the medium product CaHPO4⋅2H2O (30 min∼1 h), the following complete hydration of Ca4(PO4)2O and the initially formed CaHPO4⋅2H2O (2∼6 h), and the final self-setting of α-Ca3 - x Sr x (PO4)2 (6 h∼). The compressive strength of Sr-CPC, which was closely related to the transformation rate of Sr-containing hydroxyapatite, tended to increase with the extension of hydration time. In addition, Sr-CPC possessed favorable cytocompatibility and the effect of Sr ions on cytocompatibility of Sr-CPC was not obvious at low Sr contents. The present study suggests α-Ca3 - x Sr x (PO4)2 is a kind of vital Sr-containing salt source which is useful to develop some novel Sr-containing biomaterials. In addition, the new Sr-containing cement system based on this simple binary α-Ca3 - x Sr x (PO4)2/Ca4(PO4)2O cement powder displayed an attractive clinical application potential in orthopedics.

Utilizing machine learning dimensionality reduction for risk stratification of chest pain patients in the emergency department.

BACKGROUND: Chest pain is among the most common presenting complaints in the emergency department (ED). Swift and accurate risk stratification of chest pain patients in the ED may improve patient outcomes and reduce unnecessary costs. Traditional logistic regression with stepwise variable selection has been used to build risk prediction models for ED chest pain patients. In this study, we aimed to investigate if machine learning dimensionality reduction methods can improve performance in deriving risk stratification models. METHODS: A retrospective analysis was conducted on the data of patients > 20 years old who presented to the ED of Singapore General Hospital with chest pain between September 2010 and July 2015. Variables used included demographics, medical history, laboratory findings, heart rate variability (HRV), and heart rate n-variability (HRnV) parameters calculated from five to six-minute electrocardiograms (ECGs). The primary outcome was 30-day major adverse cardiac events (MACE), which included death, acute myocardial infarction, and revascularization within 30 days of ED presentation. We used eight machine learning dimensionality reduction methods and logistic regression to create different prediction models. We further excluded cardiac troponin from candidate variables and derived a separate set of models to evaluate the performance of models without using laboratory tests. Receiver operating characteristic (ROC) and calibration analysis was used to compare model performance. RESULTS: Seven hundred ninety-five patients were included in the analysis, of which 247 (31%) met the primary outcome of 30-day MACE. Patients with MACE were older and more likely to be male. All eight dimensionality reduction methods achieved comparable performance with the traditional stepwise variable selection; The multidimensional scaling algorithm performed the best with an area under the curve of 0.901. All prediction models generated in this study outperformed several existing clinical scores in ROC analysis. CONCLUSIONS: Dimensionality reduction models showed marginal value in improving the prediction of 30-day MACE for ED chest pain patients. Moreover, they are black box models, making them difficult to explain and interpret in clinical practice.

Rapid screening for individualized chemotherapy optimization of colorectal cancer: A novel conditional reprogramming technology-based functional diagnostic assay.

BACKGROUND: In vitro patient tumor models such as patient-derived organoids (PDO) and conditionally reprogrammed (CR) cell culture are important for translational research and pre-clinical drug testing. In this study we present a personalized drug sensitivity test for late stage, potentially operable colorectal cancer (CRC) using patient-derived primary tumor cells isolated with i-CR technology, an optimized CR method. We explored the clinical feasibility of using i-CR platform to guide CRC chemotherapy, and established the correlation between in vitro drug sensitivity and patient clinical response. METHODS: Primary CRC tumor cells were isolated and cultured with the i-CR technology. NGS was performed and the WES and CNV results of i-CR cells were compared with that of the original patient tumor samples. In vitro drug screenings were done with guideline chemotherapy drugs for CRC. In vivo drug response was examined with paired PDX mouse models. A double-blind co-clinical cohort study was carried out and the clinical outcomes of the enrolled patients were compared with the i-CR results. RESULTS: i-CR platform could be used to rapidly propagate primary colorectal tumor cells that represent individual patient tumors effectively by keeping the clonal heterogeneity and the genetic characteristics. Chemotherapy drug screenings with i-CR cells were comparable with that of PDX models. More importantly, i-CR results showed high accordance with the clinical outcomes of the enrolled CRC patients. CONCLUSION: i-CR platform was capable to test and optimize therapeutic regimens pre-clinically, study cancer cell biology, and model tumor re-emergence to identify new targeted therapeutics from an effective personalized medicine standpoint.

Enhancing Antibacterial Performance and Biocompatibility of Pure Titanium by a Two-Step Electrochemical Surface Coating.

A two-step electrochemical surface treatment has been developed to modify the CP Ti surface on commercially pure titanium grade 2 (CP Ti): (1) anodic oxidation to form TiO2 nanotube precoatings loaded with silver (Ag) and (2) microarc oxidation (MAO) to produce a porous Ca-P-Ag coating in an electrolyte containing Ag, Ca, and P. One-step MAO in the same electrolyte has also been used to produce porous Ca-P-Ag coatings without anodic oxidation and preloaded Ag as a control. Surface morphologies and alloying chemistry of the two coatings were characterized by SEM, EDS, and XPS. Biocompatibility and antimicrobial properties have been evaluated by the MTT method and co-culture of Staphylococcus aureus, respectively. It is demonstrated that porous coatings with high Ag content can be achieved on the CP Ti by the two-step treatment. The optimized MAO voltage for excellent comprehensive properties of the coating is 350 V, in which a suitable chemical equilibrium between Ag, Ca, and P contents and a Ca/P ratio of 1.67 similar to HA can be obtained, and the Ag particles are in the size of less than 100 nm and embedded into the underneath of the coating surface. After being contacted with S. aureus for 1 and 7 days, the average bactericidal rates were 99.53 and 89.27% and no cytotoxicity was detected. In comparison, the one-step MAO coatings contained less Ag, had a lower Ca/P ratio, and showed lower antimicrobial ability than the two-step treated samples.

Effects of different sulfonation times and post-treatment methods on the characterization and cytocompatibility of sulfonated PEEK.

Polyetheretherketone (PEEK) has been becoming a popular implant material in orthopaedic applications. The lack of bioactivity affects PEEK's long-term lifetime, and appropriate surface modification is an effective way to enhance its bioactivity. Sulfonation of PEEK can endow PEEK with a 3 D porous network surface and improve its bioactivity. This study is aimed at exploring an optimal sulfonation time and a post-treatment method of PEEK sulfonation. PEEK was immersed into concentrated sulfuric acid for different sulfonation times and experienced different post-treatment methods to turn into sulfonated PEEK (SPEEK). The immersion times were 0.5 min (SPEEK0.5), 1 min (SPEEK1), 3 min (SPEEK3), 5 min (SPEEK5) and 7 min (SPEEK7), and the post-treatment methods were acetone rinsing (SPEEK-T1), hydrothermal treatment (SPEEK-T2) and NaOH immersion (SPEEK-T3). Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy, hydrophilic property, ion release and cell viability evaluations were performed to optimize the sulfonation time, and the SEM, EDS, ion release and cell viability were analysed to optimize the post-treatment method. The results showed a porous network structure was formed on all samples of SPEEK, and the porous structure became more obvious and the S concentration increased with increasing sulfonation time. However, too long of an immersion time (SPEEK7) tended to damage the superficial porous structure and left a higher content of sulfuric acid, which could inhibit the growth of MC3T3E1 cells on its surface. In addition, the surface morphology, residual sulfuric acid and cytocompatibility of SPEEK-T1, SPEEK-T2 and SPEEK-T3 were not distinctly different. In conclusion, a 5-min sulfonation time was considered to be the optimal selection, and acetone rinsing, hydrothermal treatment and NaOH immersion showed the same effect in removing the residual sulfuric acid. The understanding of optimal sulfonation time and post-treatment method can provide a theoretical basis in preparing SPEEK for orthopaedic applications.

Heart rate n-variability (HRnV) and its application to risk stratification of chest pain patients in the emergency department.

BACKGROUND: Chest pain is one of the most common complaints among patients presenting to the emergency department (ED). Causes of chest pain can be benign or life threatening, making accurate risk stratification a critical issue in the ED. In addition to the use of established clinical scores, prior studies have attempted to create predictive models with heart rate variability (HRV). In this study, we proposed heart rate n-variability (HRnV), an alternative representation of beat-to-beat variation in electrocardiogram (ECG), and investigated its association with major adverse cardiac events (MACE) in ED patients with chest pain. METHODS: We conducted a retrospective analysis of data collected from the ED of a tertiary hospital in Singapore between September 2010 and July 2015. Patients > 20 years old who presented to the ED with chief complaint of chest pain were conveniently recruited. Five to six-minute single-lead ECGs, demographics, medical history, troponin, and other required variables were collected. We developed the HRnV-Calc software to calculate HRnV parameters. The primary outcome was 30-day MACE, which included all-cause death, acute myocardial infarction, and revascularization. Univariable and multivariable logistic regression analyses were conducted to investigate the association between individual risk factors and the outcome. Receiver operating characteristic (ROC) analysis was performed to compare the HRnV model (based on leave-one-out cross-validation) against other clinical scores in predicting 30-day MACE. RESULTS: A total of 795 patients were included in the analysis, of which 247 (31%) had MACE within 30 days. The MACE group was older, with a higher proportion being male patients. Twenty-one conventional HRV and 115 HRnV parameters were calculated. In univariable analysis, eleven HRV and 48 HRnV parameters were significantly associated with 30-day MACE. The multivariable stepwise logistic regression identified 16 predictors that were strongly associated with MACE outcome; these predictors consisted of one HRV, seven HRnV parameters, troponin, ST segment changes, and several other factors. The HRnV model outperformed several clinical scores in the ROC analysis. CONCLUSIONS: The novel HRnV representation demonstrated its value of augmenting HRV and traditional risk factors in designing a robust risk stratification tool for patients with chest pain in the ED.

Conditionally reprogrammed colorectal cancer cells combined with mouse avatars identify synergy between EGFR and MEK or CDK4/6 inhibitors.

Preclinical models, including patient-derived xenograft (PDX) and organoid and primary cell culture, are essential for studies of cancer cell biology and facilitate translational research and individualization of therapy. We explored the optimum preclinical model by modifying the conventional conditional reprogramming (CR) system followed by screening effective targeted drug combinations against colorectal cancer (CRC). By modifying the ingredients of the culture medium used in a conventional CR system, a novel individualized CR system (termed i-CR) was established. Tumor samples from CRC patients were collected and PDX models were derived followed by high-throughput i-CR drug screening and validation of the effective targeted drug combinations. The i-CR system selectively expanded tumor cells rather than normal epithelial cells and facilitated high-throughput drug screening when combined with high-content imaging and quantitative analysis of cell proliferation. Using inhibitors targeting multiple signaling pathways identified by high-throughput i-CR drug screening, we discovered that inhibition of the EGFR and MEK or CDK4/6 pathways exerted a synergistic inhibitory effect against CRC, and we noted super-synergistic effects when EGFR, MEK, and CDK4/6 inhibitors were used simultaneously. These data were validated using paired PDX models, which showed marked inhibition of tumor growth. The novel i-CR system combined with PDX models will enable individualization of therapy and drug discovery, and strategies combining EGFR, MEK, and CDK4/6 inhibitors warrant clinical validation.

In vitro antibacterial activity and cytocompatibility of magnesium-incorporated poly(lactide-co-glycolic acid) scaffolds.

BACKGROUND: Bone defects are often combined with the risk of infection in the clinic, and artificial bone substitutes are often implanted to repair the defective bone. However, the implant materials are carriers for bacterial growth, and biofilm can form on the implant surface, which is difficult to eliminate using antibiotics and the host immune system. Magnesium (Mg) was previously reported to possess antibacterial potential. METHODS: In this study, Mg was incorporated into poly(lactide-co-glycolic acid) (PLGA) to fabricate a PLGA/Mg scaffold using a low-temperature rapid-prototyping technique. All scaffolds were divided into three groups: PLGA (P), PLGA/10 wt% Mg with low Mg content (PM-L) and PLGA/20 wt% Mg with high Mg content (PM-H). The degradation test of the scaffolds was conducted by immersing them into the trihydroxymethyl aminomethane-hydrochloric acid (Tris-HCl) buffer solution and measuring the change of pH values and concentrations of Mg ions. The antibacterial activity of the scaffolds was investigated by the spread plate method, tissue culture plate method, scanning electron microscopy and confocal laser scanning microscopy. Additionally, the cell attachment and proliferation of the scaffolds were evaluated by the cell counting kit-8 (CCK-8) assay using MC3T3-E1 cells. RESULTS: The Mg-incorporated scaffolds degraded and released Mg ions and caused an increase in the pH value. Both PM-L and PM-H inhibited bacterial growth and biofilm formation, and PM-H exhibited higher antibacterial activity than PM-L after incubation for 24 and 48 h. Cell tests revealed that PM-H exerted a suppressive effect on cell attachment and proliferation. CONCLUSIONS: These findings demonstrated that the PLGA/Mg scaffolds possessed favorable antibacterial activity, and a higher content of Mg (20%) exhibited higher antibacterial activity and inhibitory effects on cell attachment and proliferation than low Mg content (10%).

Evaluating the bioactivity of a hydroxyapatite-incorporated polyetheretherketone biocomposite.

BACKGROUND: Polyetheretherketone (PEEK) exhibits stable chemical properties, excellent biocompatibility, and rational mechanical properties that are similar to those of human cortical bone, but the lack of bioactivity impedes its clinical application. METHODS: In this study, hydroxyapatite (HA) was incorporated into PEEK to fabricate HA/PEEK biocomposite using a compounding and injection-molding technique. The tensile properties of the prepared HA/PEEK composites (HA content from 0 to 40 wt%) were tested to choose an optimal HA content. To evaluate the bioactivity of the composite, the cell attachment, proliferation, spreading and alkaline phosphatase (ALP) activity of MC3T3-E1 cells, and apatite formation after immersion in simulated body fluid (SBF), and osseointegration in a rabbit cranial defect model were investigated. The results were compared to those from ultra-high molecular weight polyethylene (UHMWPE) and pure PEEK. RESULTS: By evaluating the tensile properties and elastic moduli of PEEK composite samples/PEEK composites with different HA contents, the 30 wt% HA/PEEK composite was chosen for use in the subsequent tests. The results of the cell tests demonstrated that PEEK composite samples/PEEK composite exhibited better cell attachment, proliferation, spreading, and higher ALP activity than those of UHMWPE and pure PEEK. Apatite islands formed on the HA/PEEK composite after immersion in SBF for 7 days and grew continuously with longer time periods. Animal tests indicated that bone contact and new bone formation around the HA/PEEK composite were more obvious than those around UHMWPE and pure PEEK. CONCLUSIONS: The HA/PEEK biocomposite created by a compounding and injection-molding technique exhibited enhanced osteogenesis and could be used as a candidate of orthopedic implants.

A novel heart rate variability based risk prediction model for septic patients presenting to the emergency department.

A quick, objective, non-invasive means of identifying high-risk septic patients in the emergency department (ED) can improve hospital outcomes through early, appropriate management. Heart rate variability (HRV) analysis has been correlated with mortality in critically ill patients. We aimed to develop a Singapore ED sepsis (SEDS) predictive model to assess the risk of 30-day in-hospital mortality in septic patients presenting to the ED. We used demographics, vital signs, and HRV parameters in model building and compared it with the modified early warning score (MEWS), national early warning score (NEWS), and quick sequential organ failure assessment (qSOFA) score.Adult patients clinically suspected to have sepsis in the ED and who met the systemic inflammatory response syndrome (SIRS) criteria were included. Routine triage electrocardiogram segments were used to obtain HRV variables. The primary endpoint was 30-day in-hospital mortality. Multivariate logistic regression was used to derive the SEDS model. MEWS, NEWS, and qSOFA (initial and worst measurements) scores were computed. Receiver operating characteristic (ROC) analysis was used to evaluate their predictive performances.Of the 214 patients included in this study, 40 (18.7%) met the primary endpoint. The SEDS model comprises of 5 components (age, respiratory rate, systolic blood pressure, mean RR interval, and detrended fluctuation analysis α2) and performed with an area under the ROC curve (AUC) of 0.78 (95% confidence interval [CI]: 0.72-0.86), compared with 0.65 (95% CI: 0.56-0.74), 0.70 (95% CI: 0.61-0.79), 0.70 (95% CI: 0.62-0.79), 0.56 (95% CI: 0.46-0.66) by qSOFA (initial), qSOFA (worst), NEWS, and MEWS, respectively.HRV analysis is a useful component in mortality risk prediction for septic patients presenting to the ED.

Heart Rate Variability Analysis in Patients Who Have Bradycardia Presenting to the Emergency Department with Chest Pain.

BACKGROUND: Heart rate variability (HRV) is a noninvasive method to measure the function of the autonomic nervous system. It has been used to risk stratify patients with undifferentiated chest pain in the emergency department (ED). However, bradycardia can have a modifying effect on HRV. OBJECTIVE: In this study, we aimed to determine how bradycardia affected HRV analysis in patients who presented with chest pain to the ED. METHODS: Adult patients presenting to the ED at Singapore General Hospital with chest pain were included in the study. Patients with non-sinus rhythm on electrocardiogram (ECG) were excluded. HRV parameters, including time domain, frequency domain, and nonlinear variables, were analyzed from a 5-min ECG segment. Occurrence of a major adverse cardiac event ([MACE], e.g., acute myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, or mortality) within 30 days of presentation to the ED was also recorded. RESULTS: A total of 797 patients were included for analysis with 248 patients (31.1%) with 30-day MACE and 135 patients with bradycardia (16.9%). Compared to non-bradycardic patients, bradycardic patients had significant differences in all HRV parameters suggesting an increased parasympathetic component. Among non-bradycardic patients, comparing those who did and did not have 30-day MACE, there were significant differences predominantly in time domain variables, suggesting decreased HRV. In bradycardic patients, the same analysis revealed significant differences in predominantly frequency-domain variables suggesting decreased parasympathetic input. CONCLUSIONS: Chest pain patients with bradycardia have increased HRV compared to those without bradycardia. This may have important implications on HRV modeling strategies for risk stratification of bradycardic and non-bradycardic chest pain patients.

Integrating heart rate variability, vital signs, electrocardiogram, and troponin to triage chest pain patients in the ED.

BACKGROUND: Current triage methods for chest pain patients typically utilize symptoms, electrocardiogram (ECG), and vital sign data, requiring interpretation by dedicated triage clinicians. In contrast, we aimed to create a quickly obtainable model integrating the objective parameters of heart rate variability (HRV), troponin, ECG, and vital signs to improve accuracy and efficiency of triage for chest pain patients in the emergency department (ED). METHODS: Adult patients presenting to the ED with chest pain from September 2010 to July 2015 were conveniently recruited. The primary outcome was a composite of revascularization, death, cardiac arrest, cardiogenic shock, or lethal arrhythmia within 72-h of presentation to the ED. To create the chest pain triage (CPT) model, logistic regression was done where potential covariates comprised of vital signs, ECG parameters, troponin, and HRV measures. Current triage methods at our institution and modified early warning score (MEWS) were used as comparators. RESULTS: A total of 797 patients were included for final analysis of which 146 patients (18.3%) met the primary outcome. Patients were an average age of 60years old, 68% male, and 56% triaged to the most acute category. The model consisted of five parameters: pain score, ST-elevation, ST-depression, detrended fluctuation analysis (DFA) α1, and troponin. CPT model>0.09, CPT model>0.15, current triage methods, and MEWS≥2 had sensitivities of 86%, 74%, 75%, and 23%, respectively, and specificities of 45%, 71%, 48%, and 78%, respectively. CONCLUSION: The CPT model may improve current clinical triage protocols for chest pain patients in the ED.