Definition and Epidemiology of Sepsis.

Here we review the epidemiology of sepsis, focusing on its definition, incidence, and mortality, as well as the demographic insights and risk factors that influence its occurrence and outcomes. We address how age, sex, and racial/ethnic disparities impact upon incidence and mortality rates. Sepsis is more frequent and severe among the elderly, males, and certain racial and ethnic groups. Poor socioeconomic status, geographic location, and pre-existing comorbidities also elevate the risk of developing and dying from sepsis. Seasonal variations, with an increased incidence during winter months, is also apparent. We delve into the predictive value of disease severity scores such as the Sequential Organ Failure Assessment score. We also highlight issues relating to coding and administrative data that can generate erroneous and misleading information, and the need for greater consistency. The Sepsis-3 definitions, offering more precise clinical criteria, are a step in the right direction. This overview will, we hope, facilitate understanding of the multi-faceted epidemiological characteristics of sepsis and current challenges.

Development and translation of thiometallate sulfide donors using a porcine model of coronary occlusion and reperfusion.

Sulfide-releasing compounds reduce reperfusion injury by decreasing mitochondria-derived reactive oxygen species production. We previously characterised ammonium tetrathiomolybdate (ATTM), a clinically used copper chelator, as a sulfide donor in rodents. Here we assessed translation to large mammals prior to clinical testing. In healthy pigs an intravenous ATTM dose escalation revealed a reproducible pharmacokinetic/pharmacodynamic (PK/PD) relationship with minimal adverse clinical or biochemical events. In a myocardial infarction (1-h occlusion of the left anterior descending coronary artery)-reperfusion model, intravenous ATTM or saline was commenced just prior to reperfusion. ATTM protected the heart (24-h histological examination) in a drug-exposure-dependent manner (r2 = 0.58, p < 0.05). Blood troponin T levels were significantly (p < 0.05) lower in ATTM-treated animals while myocardial glutathione peroxidase activity, an antioxidant selenoprotein, was elevated (p < 0.05). Overall, our study represents a significant advance in the development of sulfides as therapeutics and underlines the potential of ATTM as a novel adjunct therapy for reperfusion injury. Mechanistically, our study suggests that modulating selenoprotein activity could represent an additional mode of action of sulfide-releasing drugs.

Preoperative aerobic fitness and perioperative outcomes in patients undergoing cystectomy before and after implementation of a national lockdown.

Background: Lower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy. Methods: We reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared. Results: We identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9-10.9] vs 10.3 [9.1-12.3] ml kg-1 min-1; P=0.0002), peak oxygen uptake (15.5 [12.9-19.1] vs 17.5 [14.4-21.0] ml kg-1 min-1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4-38.5] vs 33.4 [30.5-36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143-6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368-6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427-7.960; P=0.004), compared with pre-lockdown on univariate analysis. Conclusions: Lockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy.

High-flow nasal oxygen versus conventional oxygen therapy and noninvasive ventilation in COVID-19 respiratory failure: a systematic review and network meta-analysis of randomised controlled trials.

BACKGROUND: Noninvasive methods of respiratory support, including noninvasive ventilation (NIV), continuous positive airway pressure (CPAP), and high-flow nasal oxygen (HFNO), are potential strategies to prevent progression to requirement for invasive mechanical ventilation in acute hypoxaemic respiratory failure. The COVID-19 pandemic provided an opportunity to understand the utility of noninvasive respiratory support among a homogeneous cohort of patients with contemporary management of acute respiratory distress syndrome. We performed a network meta-analysis of studies evaluating the efficacy of NIV (including CPAP) and HFNO, compared with conventional oxygen therapy (COT), in patients with COVID-19. METHODS: PubMed, Embase, and the Cochrane library were searched in May 2023. Standard random-effects meta-analysis was used first to estimate all direct pairwise associations and the results from all studies were combined using frequentist network meta-analysis. Primary outcome was treatment failure, defined as discontinuation of HFNO, NIV, or COT despite progressive disease. Secondary outcome was mortality. RESULTS: We included data from eight RCTs with 2302 patients, (756 [33%] assigned to COT, 371 [16%] to NIV, and 1175 [51%] to HFNO). The odds of treatment failure were similar for NIV (P=0.33) and HFNO (P=0.25), and both were similar to that for COT (reference category). The odds of mortality were similar for all three treatments (odds ratio for NIV vs COT: 1.06 [0.46-2.44] and HFNO vs COT: 0.97 [0.57-1.65]). CONCLUSIONS: Noninvasive ventilation, high-flow nasal oxygen, and conventional oxygen therapy are comparable with regards to treatment failure and mortality in COVID-19-associated acute respiratory failure. PROSPERO REGISTRATION: CRD42023426495.

Prediction of Complications and Prognostication in Perioperative Medicine: A Systematic Review and PROBAST Assessment of Machine Learning Tools.

BACKGROUND: The utilization of artificial intelligence and machine learning as diagnostic and predictive tools in perioperative medicine holds great promise. Indeed, many studies have been performed in recent years to explore the potential. The purpose of this systematic review is to assess the current state of machine learning in perioperative medicine, its utility in prediction of complications and prognostication, and limitations related to bias and validation. METHODS: A multidisciplinary team of clinicians and engineers conducted a systematic review using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. Multiple databases were searched, including Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, PubMed, Medline, Embase, and Web of Science. The systematic review focused on study design, type of machine learning model used, validation techniques applied, and reported model performance on prediction of complications and prognostication. This review further classified outcomes and machine learning applications using an ad hoc classification system. The Prediction model Risk Of Bias Assessment Tool (PROBAST) was used to assess risk of bias and applicability of the studies. RESULTS: A total of 103 studies were identified. The models reported in the literature were primarily based on single-center validations (75%), with only 13% being externally validated across multiple centers. Most of the mortality models demonstrated a limited ability to discriminate and classify effectively. The PROBAST assessment indicated a high risk of systematic errors in predicted outcomes and artificial intelligence or machine learning applications. CONCLUSIONS: The findings indicate that the development of this field is still in its early stages. This systematic review indicates that application of machine learning in perioperative medicine is still at an early stage. While many studies suggest potential utility, several key challenges must be first overcome before their introduction into clinical practice.

p140Cap modulates the mevalonate pathway decreasing cell migration and enhancing drug sensitivity in breast cancer cells.

p140Cap is an adaptor protein involved in assembling multi-protein complexes regulating several cellular processes. p140Cap acts as a tumor suppressor in breast cancer (BC) and neuroblastoma patients, where its expression correlates with a better prognosis. The role of p140Cap in tumor metabolism remains largely unknown. Here we study the role of p140Cap in the modulation of the mevalonate (MVA) pathway in BC cells. The MVA pathway is responsible for the biosynthesis of cholesterol and non-sterol isoprenoids and is often deregulated in cancer. We found that both in vitro and in vivo, p140Cap cells and tumors show an increased flux through the MVA pathway by positively regulating the pace-maker enzyme of the MVA pathway, the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), via transcriptional and post-translational mechanisms. The higher cholesterol synthesis is paralleled with enhanced cholesterol efflux. Moreover, p140Cap promotes increased cholesterol localization in the plasma membrane and reduces lipid rafts-associated Rac1 signalling, impairing cell membrane fluidity and cell migration in a cholesterol-dependent manner. Finally, p140Cap BC cells exhibit decreased cell viability upon treatments with statins, alone or in combination with chemotherapeutic at low concentrations in a synergistic manner. Overall, our data highlight a new perspective point on tumor suppression in BC by establishing a previously uncharacterized role of the MVA pathway in p140Cap expressing tumors, thus paving the way to the use of p140Cap as a potent biomarker to stratify patients for better tuning therapeutic options.

The role of tumor microenvironment in drug resistance: emerging technologies to unravel breast cancer heterogeneity.

Breast cancer is a highly heterogeneous disease, at both inter- and intra-tumor levels, and this heterogeneity is a crucial determinant of malignant progression and response to treatments. In addition to genetic diversity and plasticity of cancer cells, the tumor microenvironment contributes to tumor heterogeneity shaping the physical and biological surroundings of the tumor. The activity of certain types of immune, endothelial or mesenchymal cells in the microenvironment can change the effectiveness of cancer therapies via a plethora of different mechanisms. Therefore, deciphering the interactions between the distinct cell types, their spatial organization and their specific contribution to tumor growth and drug sensitivity is still a major challenge. Dissecting intra-tumor heterogeneity is currently an urgent need to better define breast cancer biology and to develop therapeutic strategies targeting the microenvironment as helpful tools for combined and personalized treatment. In this review, we analyze the mechanisms by which the tumor microenvironment affects the characteristics of tumor heterogeneity that ultimately result in drug resistance, and we outline state of the art preclinical models and emerging technologies that will be instrumental in unraveling the impact of the tumor microenvironment on resistance to therapies.

Association Between Hypocholesterolemia and Mortality in Critically Ill Patients With Sepsis: A Systematic Review and Meta-Analysis.

To ascertain the association between cholesterol and triglyceride levels on ICU admission and mortality in patients with sepsis. DATA SOURCES: Systematic review and meta-analysis of published studies on PubMed and Embase. STUDY SELECTION: All observational studies reporting ICU admission cholesterol and triglyceride levels in critically ill patients with sepsis were included. Authors were contacted for further data. DATA EXTRACTION: Eighteen observational studies were identified, including 1,283 patients with a crude overall mortality of 33.3%. Data were assessed using Revman (Version 5.1, Cochrane Collaboration, Oxford, United Kingdom) and presented as mean difference (MD) with 95% CIs, p values, and I 2 values. DATA SYNTHESIS: Admission levels of total cholesterol (17 studies, 1,204 patients; MD = 0.52 mmol/L [0.27-0.77 mmol/L]; p < 0.001; I 2 = 91%), high-density lipoprotein (HDL)-cholesterol (14 studies, 991 patients; MD = 0.08 mmol/L [0.01-0.15 mmol/L]; p = 0.02; I 2 = 61%), and low-density lipoprotein (LDL)-cholesterol (15 studies, 1,017 patients; MD = 0.18 mmol/L [0.04-0.32 mmol/L]; p = 0.01; I 2 = 71%) were significantly lower in eventual nonsurvivors compared with survivors. No association was seen between admission triglyceride levels and mortality (15 studies, 1,070 patients; MD = 0.00 mmol/L [-0.16 to 0.15 mmol/L]; p = -0.95; I 2 = 79%). CONCLUSIONS: Mortality was associated with lower levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol, but not triglyceride levels, in patients admitted to ICU with sepsis. The impact of cholesterol replacement on patient outcomes in sepsis, particularly in at-risk groups, merits investigation.

Clinical performance of lung ultrasound in predicting time-dependent changes in lung aeration in ARDS patients.

To evaluate whether lung ultrasound is reliable bedside tool to monitor changes of lung aeration at the early and late stages of ARDS. LUS was performed in ARDS patients that underwent at least two consecutive CT scan at ICU admission and at least 1 week after admission. Twelve fields were evaluated and graded from 0 (normal) to 3 (consolidation). Changes of LUS score in twelve fields (ΔLUStot) and in four ventral (ΔLUSV), intermediate (ΔLUSI) and dorsal (ΔLUSD) zones were calculated at each time points. Three categories were described: Improve (ΔLUS < 0), Equal (ΔLUS = 0) or Worse (ΔLUS > 0). LUS scores were correlated with total changes in lung CT aeration (ΔCTair) and with normally, poorly and not aerated regions (ΔCTnorm, ΔCTpoor and ΔCTnot, respectively). Eleven patients were enrolled. ΔLUStot had significant correlation with ΔCTair (r = - 0.74, p < 0.01). ΔLUSV, ΔLUSI and ΔLUSD showed significant correlations with ΔCTair (r = - 0.66, r = - 0.69, r = - 0.63, respectively; p < 0.05). Compared to Equal, Improve and Worse categories had significantly higher (p < 0.01) and lower (p < 0.05) ΔCTair values, respectively. Compared to Equal, Improve and Worse categories had lower (p < 0.01) and higher (p < 0.01) ΔCTnot values, respectively. LUS score had a good correlation with lung CT in detecting changes of lung aeration.

Cholesterol and Its Derivatives: Multifaceted Players in Breast Cancer Progression.

Cholesterol is an essential lipid primarily synthesized in the liver through the mevalonate pathway. Besides being a precursor of steroid hormones, bile acid, and vitamin D, it is an essential structural component of cell membranes, is enriched in membrane lipid rafts, and plays a key role in intracellular signal transduction. The lipid homeostasis is finely regulated end appears to be impaired in several types of tumors, including breast cancer. In this review, we will analyse the multifaceted roles of cholesterol and its derivatives in breast cancer progression. As an example of the bivalent role of cholesterol in the cell membrane of cancer cells, on the one hand, it reduces membrane fluidity, which has been associated with a more aggressive tumor phenotype in terms of cell motility and migration, leading to metastasis formation. On the other hand, it makes the membrane less permeable to small water-soluble molecules that would otherwise freely cross, resulting in a loss of chemotherapeutics permeability. Regarding cholesterol derivatives, a lower vitamin D is associated with an increased risk of breast cancer, while steroid hormones, coupled with the overexpression of their receptors, play a crucial role in breast cancer progression. Despite the role of cholesterol and derivatives molecules in breast cancer development is still controversial, the use of cholesterol targeting drugs like statins and zoledronic acid appears as a challenging promising tool for breast cancer treatment.

Modulation of LTCC Pathways by a Melusin Mimetic Increases Ventricular Contractility During LPS-Induced Cardiomyopathy.

AIM: Sepsis-induced cardiomyopathy is commonplace and carries an increased risk of death. Melusin, a cardiac muscle-specific chaperone, exerts cardioprotective function under varied stressful conditions through activation of the AKT pathway. The objective of this study was to determine the role of melusin in the pathogenesis of lipopolysaccharide (LPS)-induced cardiac dysfunction and to explore its signaling pathway for the identification of putative therapeutic targets. METHODS AND RESULTS: Prospective, randomized, controlled experimental study in a research laboratory. Melusin overexpressing (MelOV) and wild-type (MelWT) mice were used. MelOV and MelWT mice were injected intraperitoneally with LPS. Cardiac function was assessed using trans-thoracic echocardiography. Myocardial expression of L-type calcium channel (LTCC), phospho-Akt and phospho-Gsk3-b were also measured. In separate experiments, wild-type mice were treated post-LPS challenge with the allosteric Akt inhibitor Arq092 and a mimetic peptide (R7W-MP) targeting the LTCC. The impact of these therapies on protein-protein interactions, cardiac function, and survival was assessed. MelOV mice had limited derangement in cardiac function after LPS challenge. Protection was associated with higher Akt and Gsk3-b phosphorylation and restored LTCC density. Pharmacological inhibition of Akt activity reversed melusin-dependent cardiac protection. Treatment with R7W-MP preserved cardiac function in wild-type mice after LPS challenge and significantly improved survival. CONCLUSIONS: This study identifies AKT / Melusin as a key pathway for preserving cardiac function following LPS challenge. The cell-permeable mimetic peptide (R7W-MP) represents a putative therapeutic for sepsis-induced cardiomyopathy.

Non-invasive respiratory support in the management of acute COVID-19 pneumonia: considerations for clinical practice and priorities for research.

Non-invasive respiratory support (NIRS) has increasingly been used in the management of COVID-19-associated acute respiratory failure, but questions remain about the utility, safety, and outcome benefit of NIRS strategies. We identified two randomised controlled trials and 83 observational studies, compromising 13 931 patients, that examined the effects of NIRS modalities-high-flow nasal oxygen, continuous positive airway pressure, and bilevel positive airway pressure-on patients with COVID-19. Of 5120 patients who were candidates for full treatment escalation, 1880 (37%) progressed to invasive mechanical ventilation and 3658 of 4669 (78%) survived to study end. Survival was 30% among the 1050 patients for whom NIRS was the stated ceiling of treatment. The two randomised controlled trials indicate superiority of non-invasive ventilation over high-flow nasal oxygen in reducing the need for intubation. Reported complication rates were low. Overall, the studies indicate that NIRS in patients with COVID-19 is safe, improves resource utilisation, and might be associated with better outcomes. To guide clinical decision making, prospective, randomised studies are needed to address timing of intervention, optimal use of NIRS modalities-alone or in combination-and validation of tools such as oxygenation indices, response to a trial of NIRS, and inflammatory markers as predictors of treatment success.

Clinical performance of lung ultrasound in predicting ARDS morphology.

BACKGROUND: To assess diagnostic performance of lung ultrasound (LUS) in identifying ARDS morphology (focal vs non-focal), compared with the gold standard computed tomography. METHODS: Mechanically ventilated ARDS patients undergoing lung computed tomography and ultrasound were enrolled. Twelve fields, were evaluated. LUS score was graded from 0 (normal) to 3 (consolidation) according to B-lines extent. Total and regional LUS score as the sum of the four ventral (LUSV), intermediate (LUSI) or dorsal (LUSD) fields, were calculated. Based on lung CT, ARDS morphology was defined as (1) focal (loss of aeration with lobar distribution); (2) non-focal (widespread loss of aeration or segmental loss of aeration distribution associated with uneven lung attenuation areas), and diagnostic accuracy of LUS in discriminating ARDS morphology was determined by AU-ROC in training and validation set of patients. RESULTS: Forty-seven patients with ARDS (25 training set and 22 validation set) were enrolled. LUSTOT, LUSV and LUSI but not LUSD score were significantly lower in focal than in non-focal ARDS morphologies (p < .01). The AU-ROC curve of LUSTOT, LUSV, LUSI and LUSD for identification of non-focal ARDS morphology were 0.890, 0.958, 0.884 and 0.421, respectively. LUSV value ≥ 3 had the best predictive value (sensitivity = 0.95, specificity = 1.00) in identifying non-focal ARDS morphology. In the validation set, an LUSV score ≥ 3 confirmed to be highly predictive of non-focal ARDS morphology, with a sensitivity and a specificity of 94% and 100%. CONCLUSIONS: LUS had a valuable performance in distinguishing ARDS morphology.

Pathophysiology of sepsis.

PURPOSE OF REVIEW: To provide a current overview of sepsis pathophysiology. RECENT FINDINGS: The emphasis on sepsis pathophysiology has moved away from the pathogen - the initiating factor - and instead is focussed upon the abnormal and exaggerated host response. Instead of targeted eradication of the infection, the host response activates or suppresses multiple downstream pathways, leading to multiple organ dysfunction. SUMMARY: Sepsis represents a dysregulated host response to infection leading to organ dysfunction. Here, the pathogen triggers an initial exaggerated inflammatory-immune response that leads to activation or suppression of multiple endothelial, hormonal, bioenergetic, metabolic, immune, and other pathways. These, in turn, produce the circulatory and metabolic perturbations resulting in organ dysfunction. This review will provide an overview of underlying mechanisms and propose that these processes, whereas superficially viewed as dysfunctional, may actually be adaptive/protective in the first instance, though spilling over into maladaptation/harm depending on the magnitude of the host response.

Molecular Insights into the MAPK Cascade during Viral Infection: Potential Crosstalk between HCQ and HCQ Analogues.

The mitogen-activated protein kinase (MAPK) pathway links the cell-surface receptors to the transcription machinery, transducing the extracellular signals into several outputs, which may also adapt the host defense mechanism to viral attacks. The Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) that causes the COrona VIrus Disease 2019 (COVID-19) has infected upwards of nearly 70 million people and worldwide has claimed more than 1,600,000 deaths. So far, there continues to be no specific treatment for this novel coronavirus-induced disease. In the search to control the global COVID-19 pandemic, some eastern and developing countries have approved a variety of treatments with controversial efficacy, among which is the use of the antimalarial hydroxychloroquine (HCQ). Interestingly, prior data had indicated that the HCQ/CQ could influence the MAPK cascade. The main aim of this review is to address molecular mechanisms, beyond drugs, that can be helpful against viral infection for this and future pandemics. We will highlight (1) the contribution of the MAPK cascade in viral infection and (2) the possible use of MAPK inhibitors in curbing viral infections, alone or in combination with HCQ and quinoline analogues. We are convinced that understanding the molecular patterns of viral infections will be critical for new therapeutical approaches to control this and other severe diseases.

Role of azithromycin in antiviral treatment: enhancement of interferon-dependent antiviral pathways and mitigation of inflammation may rely on inhibition of the MAPK cascade?

Azithromycin is a macrolide-type antibiotic used against a broad range of bacterial infection, such as respiratory tract, skin, ear, eye infections, and sexually transmitted diseases. The ongoing severe acute respiratory syndrome (SARS) mediated by Corona Virus 2 (CoVid19) is a global health concern and various countries witnessed the loss of precious human life. In fall 2020, the absence of specific suitable medication or vaccine is still a major cause of concern to fight the pandemic while different countries have already started using their own medication and available resources to save the life of their citizens. At the present, in many countries around the world, we witnessed the use of the antibiotic azithromycin towards the medication of CoVid19; even its effect on anti CoVid19 is still controversial. This mini review aims to address whether azithromycin can affect molecular pathway involved in inflammatory immunity upon viral infection, to find out the rationale behind the use of azithromycin in the treatment of CoVid19. Overall, the data show that the mechanism of action of azithromycin in viral infection may be dependent on a global amplification of the interferon-dependent pathways mediating antiviral responses, leading to a reduction of viral replication, together with a strong impairment of the inflammatory pathways, relying on MAPK cascade inactivation.