Phenotypic differences between dermal fibroblasts from different body sites determine their responses to tension and TGFβ1

BACKGROUND: Wounds in the nonglabrous skin of keloid-prone individuals tend to cause large disordered accumulations of collagen which extend beyond the original margins of the wound. In addition to abnormalities in keloid fibroblasts, comparison of dermal fibroblasts derived from nonwounded glabrous or nonglabrous skin revealed differences that may account for the observed location of keloids. METHODS: Fibroblast apoptosis and the cellular content of α-smooth-muscle actin, TGFβ1 receptorII and ED-A fibronectin were estimated by FACS analysis. The effects of TGFβ1 and serum were examined. RESULTS: In monolayer cultures non-glabrous fibroblasts were slower growing, had higher granularity and accumulated more α-smooth-muscle actin than fibroblasts from glabrous tissues. Keloid fibroblasts had the highest level of α-smooth-muscle actin in parallel with their expression level of ED-A fibronectin. TGFβ1 positively regulated α-smooth-muscle actin expression in all fibroblast cultures, although its effects on apoptosis in fibroblasts from glabrous and non-glabrous tissues were found to differ. The presence of collagen I in the ECM resulted in reduction of α-smooth-muscle actin. A considerable percentage of the apoptotic fibroblasts in attached gels were α-smooth-muscle actin positive. The extent of apoptosis correlated positively with increased cell and matrix relaxation. TGFβ1 was unable to overcome this apoptotic effect of matrix relaxation. CONCLUSION: The presence of myofibroblasts and the apoptosis level can be regulated by both TGFβ1 and by the extracellular matrix. However, reduction of tension in the matrix is the critical determinant. This predicts that the tension in the wound bed determines the type of scar at different body sites

An observational cohort study of the performance of the REDS score compared to the SIRS criteria, NEWS2, CURB65, SOFA, MEDS and PIRO scores to risk-stratify emergency department suspected sepsis

Objective To compare the performance of the Risk-stratification of Emergency Department suspected Sepsis (REDS) score to the SIRS criteria, NEWS2, CURB65, SOFA, MEDS and PIRO scores, to risk-stratify Emergency Department (ED) suspected sepsis patients for mortality.Method A retrospective observational cohort study of prospectively collected data. Adult patients admitted from the ED after receiving intravenous antibiotics for suspected sepsis in the year 2020, were studied. Patients with COVID-19 were excluded. The scores stated above were calculated for each patient. Receiver operator characteristics (ROC) curves were constructed for each score for the primary outcome measure, all-cause in-hospital mortality. The area under the ROC (AUROC) curves and cut-off points were identified by the statistical software. Scores above the cut-off point were deemed high-risk. The test characteristics of the high-risk groups were calculated. Comparisons were based on the AUROC curve and sensitivity for mortality of the high-risk groups. Previously published cut-off points were also studied. Calibration was also studied.Results Of the 2594 patients studied, 332 (12.8%) died. The AUROC curve for the REDS score 0.73 (95% confidence interval [CI] 0.72–0.75) was significantly greater than the AUROC curve for the SIRS criteria 0.51 (95% CI 0.49–0.53), p < .0001 and the NEWS2 score 0.69 (95% CI 0.67–0.70), p = .005, and similar to all other scores studied. Sensitivity for mortality at the respective cut-off points identified (REDS ≥3, NEWS2 ≥ 8, CURB65 ≥ 3, SOFA ≥3, MEDS ≥10 and PIRO ≥10) was greatest for the REDS score at 80.1% (95% CI 75.4–84.3) and significantly greater than the other scores. The sensitivity for mortality for an increase of two points from baseline in the SOFA score was 63% (95% CI 57.5–68.2).Conclusions In this single centre study, the REDS score had either a greater AUROC curve or sensitivity for mortality compared to the comparator scores, at the respective cut-off points identified.KEY MESSAGESThe REDS score is a simple and objective scoring system to risk-stratify for mortality in emergency department (MED) patients with suspected sepsis.The REDS score is better or equivalent to existing scoring systems in its discrimination for mortality

In vitro wound healing characteristics of amelogenins

Wound healing involves the co-ordinated actions of several cell types, soluble cell mediators and extracellular matrix (ECM). This research project intended to investigate the role of certain ECM proteins in different processes during tissue repair by studying the interaction between dermal cells and ECM. The focus has been on amelogenins, ECM proteins that under physiological conditions aggregate into spherical structures. As a resorbable biomaterial, amelogenins enhance periodontal tissue regeneration and have been introduced in the treatment of hard-to-heal ulcers. However, the mechanisms of action need to be delineated. The aim of this project was to increase the knowledge on the effects of amelogenins on cell behaviour, to further understand the role of this specific ECM protein in tissue repair and regeneration. To study the in vitro effects of amelogenins on wound healing, three human cell types; macrophages, fibroblasts, and endothelial cells, all essential for successful tissue repair, were utilised. The study designs included cell cultures, in monolayer, 3D-culture and an ex vivo model (chick aortic arch assay) for the angiogenesis studies. The evaluation methods included cell quantification, mitogenesis and apoptosis studies by BrdU incorporation and TUNEL measurements respectively, cytokine analysis by ELISA and multiplex bead array, cell surface integrin adhesion assay, gene microarray analysis, phase contrast and fluorescence microscopy for morphology and viability, and ultrastructural studies by electron microscopy. The results demonstrate that amelogenins influence the in vitro cell behaviour of all three cell types investigated. The interaction and uptake of amelogenin aggregates was demonstrated for both macrophages and fibroblasts. In addition, the possible involvement of integrin-dependent adhesion was demonstrated for fibroblasts and endothelial cells, with increased cell binding by multiple integrins subunits and αvβ3, αvβ5 and α5β1. Amelogenin treatment of cultured macrophages displayed anti-inflammatory properties, directing the release of several pro- and anti-inflammatory cytokines. In particular, induced secretion of the specific marker of alternative macrophage activation AMAC-1, along with vascular endothelial growth factor was seen, most probably resulting from a switch of macrophage phenotype to an alternatively activated cell, with tissue repair characteristics. Also, amelogenins increased cell proliferation and induced the expression of genes involved in cellular growth, migration and differentiation in normal dermal fibroblasts. Moreover, amelogenins had the capacity to restore an acute-like phenotype in senescent fibroblasts. Finally, amelogenins displayed pro-angiogenic properties in vitro and ex vivo. In conclusion, the effects of amelogenins on wound healing are plausibly, at least partly, conducted by providing macrophages, fibroblasts, and endothelial cells with tissue repair characteristics. These effects are most probably conducted through cell adhesion via integrin interaction

Prognostic performance of the REDS score, SOFA score, NEWS2 score, and the red-flag, NICE high-risk, and SIRS criteria to predict survival at 180 days, in emergency department patients admitted with suspected sepsis – An observational cohort study

BackgroundPatients admitted to hospital with sepsis are at persistent risk of poor outcome after discharge. Many tools are available to risk-stratify sepsis patients for in-hospital mortality. This study aimed to identify the best risk-stratification tool to prognosticate outcome 180 days after admission via the emergency department (ED) with suspected sepsis.MethodsA retrospective observational cohort study was performed of adult ED patients who were admitted after receiving intravenous antibiotics for the treatment of a suspected sepsis, between 1st March and 31st August 2019. The Risk-stratification of ED suspected Sepsis (REDS) score, SOFA score, Red-flag sepsis criteria met, NICE high-risk criteria met, the NEWS2 score and the SIRS criteria, were calculated for each patient. Death and survival at 180 days were noted. Patients were stratified in to high and low-risk groups as per accepted criteria for each risk-stratification tool. Kaplan–Meier curves were plotted for each tool and the log-rank test performed. The tools were compared using Cox-proportional hazard regression (CPHR). The tools were studied further in those without the following specified co-morbidities: Dementia, malignancy, Rockwood Frailty score of 6 or more, long-term oxygen therapy and previous do-not-resuscitate orders.ResultsOf the 1,057 patients studied 146 (13.8%) died at hospital discharge and 284 were known to have died within 180 days. Overall survival proportion was 74.4% at 180 days and 8.6% of the population was censored before 180 days. Only the REDS and SOFA scores identified less than 50% of the population as high-risk. All tools except the SIRS criteria, prognosticated for outcome at 180 days; Log-rank tests between high and low-risk groups were: REDS score p &amp;lt; 0.0001, SOFA score p &amp;lt; 0.0001, Red-flag criteria p = 0.001, NICE high-risk criteria p = 0.0001, NEWS2 score p = 0.003 and SIRS criteria p = 0.98. On CPHR, the REDS [Hazard ratio (HR) 2.54 (1.92–3.35)] and SOFA [HR 1.58 (1.24–2.03)] scores out-performed the other risk-stratification tools. In patients without the specified co-morbidities, only the REDS score and the SOFA score risk-stratified for outcome at 180 days.ConclusionIn this study, all the risk-stratification tools studied were found to prognosticate for outcome at 180 days, except the SIRS criteria. The REDS and SOFA scores outperformed the other tools.</jats:sec

The REDS score: a new scoring system to risk-stratify emergency department suspected sepsis: a derivation and validation study

ObjectiveTo derive and validate a new clinical prediction rule to risk-stratify emergency department (ED) patients admitted with suspected sepsis.DesignRetrospective prognostic study of prospectively collected data.SettingED.ParticipantsPatients aged ≥18 years who met two Systemic Inflammatory Response Syndrome criteria or one Red Flag sepsis criteria on arrival, received intravenous antibiotics for a suspected infection and admitted.Primary outcome measureIn-hospital all-cause mortality.MethodThe data were divided into derivation and validation cohorts. The simplified-Mortality in Severe Sepsis in the ED score and quick-SOFA scores, refractory hypotension and lactate were collectively termed ‘component scores’ and cumulatively termed the ‘Risk-stratification of ED suspected Sepsis (REDS) score’. Each patient in the derivation cohort received a score (0–3) for each component score. The REDS score ranged from 0 to 12. The component scores were subject to univariate and multivariate logistic regression analyses. The receiver operator characteristic (ROC) curves for the REDS and the components scores were constructed and their cut-off points identified. Scores above the cut-off points were deemed high-risk. The area under the ROC (AUROC) curves and sensitivity for mortality of the high-risk category of the REDS score and component scores were compared. The REDS score was internally validated.Results2115 patients of whom 282 (13.3%) died in hospital. Derivation cohort: 1078 patients with 140 deaths (13%). The AUROC curve with 95% CI, cut-off point and sensitivity for mortality (95% CI) of the high-risk category of the REDS score were: derivation: 0.78 (0.75 to 0.80); ≥3; 85.0 (78 to 90.5). Validation: 0.74 (0.71 to 0.76); ≥3; 84.5 (77.5 to 90.0). The AUROC curve and the sensitivity for mortality of the REDS score was better than that of the component scores. Specificity and mortality rates for REDS scores of ≥3, ≥5 and ≥7 were 54.8%, 88.8% and 96.9% and 21.8%, 36.0% and 49.1%, respectively.ConclusionThe REDS score is a simple and objective score to risk-stratify ED patients with suspected sepsis.</jats:sec

Treatment variables associated with outcome in emergency department patients with suspected sepsis

Abstract Background Early treatment is advocated in the management of patients with suspected sepsis in the emergency department (ED). We sought to understand the association between the ED treatments and outcome in patients admitted with suspected sepsis. The treatments studied were: (i) the time to antibiotics, where time zero is the time the patient was booked in which is also the triage time; (ii) the volume of intravenous fluid (IVF); (iii) mean arterial pressure (MAP) after 2000 ml of IVF and (iv) the final MAP in the ED. Methods We performed a retrospective analysis of the ED database of patients aged ≥ 18 year who met two SIRS criteria or one red flag sepsis criteria on arrival, received intravenous antibiotics for a suspected infection and admitted between 8th February 2016 and 31st August 2017. The primary outcome measure was all-cause in-hospital mortality. The four treatments stated above were controlled for severity of illness and subject to multivariate logistic regression and Cox proportional-hazard regression to identify independent predictors of mortality. Results Of the 2,066 patients studied 272 (13.2%) died in hospital. The median time to antibiotics was 48 (interquartile range 30–82) minutes. The time to antibiotics was an independent predictor of mortality only in those who developed refractory hypotension (RH); antibiotics administered more than 55 mins after arrival was associated with an odds ratio (OR) for mortality of 2.75 [95% confidence interval (CI) 1.22–6.14]. The number-needed-to-treat was 4. IVF &gt; 2000 ml (95% CI &gt; 500– &gt; 2100), except in RH, and a MAP ≤ 66 mmHg after 2000 ml of IVF were also independent predictors of mortality. The OR for mortality of IVF &gt; 2,000 ml in non-RH was 1.80 (95% CI 1.15–2.82); Number-needed-to-harm was 14. The OR for morality for a MAP ≤ 66 mmHg after 2000 ml of IVF was 3.42 (95% CI 2.10–5.57). A final MAP &lt; 75 mmHg in the ED was associated with, but not an independent predictor of mortality. An initial systolic blood pressure of &lt; 100 mmHg has a sensitivity of 63.3% and specificity of 88.4% for the development of RH. Conclusion In this study, antibiotics were found to be time-critical in RH. Intravenous fluids &gt; 2000 ml (except in RH) and a MAP ≤ 66 mmHg after 2000 ml of IVF were also independent predictors of mortality. </jats:sec

Simultaneous application of predictive model and least cost formulation can substantially benefit biorefineries outside Corn Belt in United States: a case study in Florida

Previously, a predictive model was developed to identify optimal blends of expensive high-quality and cheaper low-quality feedstocks for a given geographical location that can deliver high sugar yields. In this study, the optimal process conditions were tested for application at commercially-relevant higher biomass loadings. We observed lower sugar yields but 100% conversion to ethanol from a blend that contained only 20% high-quality feedstock. The impact of applying this predictive model simultaneously with least cost formulation model for a biorefinery location outside of the US Corn Belt in Lee County, Florida was investigated. A blend ratio of 0.30 EC, 0.45 SG, and 0.25 CS in Lee County was necessary to produce sugars at high yields and ethanol at a capacity of 50 MMGY. This work demonstrates utility in applying predictive model and LCF to reduce feedstock costs and supply chain risks while optimizing for product yields