Surgical Education in the 21st Century

Surgical education has evolved drastically since the 19th century. Previously education of surgical residents was limited to on job clinical training following the “see one, do one, teach one” model with knowledge gleaned from textbooks and journals. Presently a growing emphasis has been placed on both patient safety and resident well-being leading to a development of novel training paradigms. The textbook, while remaining a core source of knowledge, is now only one of many resources available to residents. Many residencies have their libraries online, making learning possible almost anywhere, even without physical books in hand. Most programs now incorporate education days where a structured curriculum allows for standardized education; this makes it less likely that residents miss out on mandatory concepts. The 2020 Covid-19 pandemic has led to further evolution of this model, making the classroom virtual yet interactive. Technology has allowed for residents to train on surgical simulators, so that laparoscopic and robotic skills may be practiced before application on a live patient. Altogether residents are afforded multiple ways to learn due to greater availability of time, structured educational modules, and technology

Eotaxin and FGF enhance signaling through an Extracellular signal-related kinase (ERK)-dependent pathway in the pathogenesis of Eosinophilic Esophagitis

<p>Abstract</p> <p>Background</p> <p>Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus and the infiltration of eosinophils into the esophagus, leading to symptoms such as dysphagia and stricture formation. Systemic immune indicators like eotaxin and fibroblast growth factor were evaluated for possible synergistic pathological effects. Moreover, blood cells, local tissue, and plasma from EoE and control subjects were studied to determine if the localized disease was associated with a systemic effect that correlated with presence of EoE disease.</p> <p>Method</p> <p>Real-time polymerase chain reaction from peripheral blood mononuclear cells (PBMC), immunohistochemistry from local esophageal biopsies, fluid assays on plasma, and fluorescence-activated cell sorting on peripheral blood cells from subjects were used to study the systemic immune indicators in newly diagnosed EoE (n = 35), treated EoE (n = 9), Gastroesophageal reflux disease (GERD) (n = 8), ulcerative colitis (n = 5), Crohn's disease (n = 5), and healthy controls (n = 8).</p> <p>Result</p> <p>Of the transcripts tested for possible immune indicators, we found extracellular signal-regulated kinase (ERK), Bcl-2, bFGF (basic fibroblast growth factor), and eotaxin levels were highly upregulated in PBMC and associated with disease presence of EoE. Increased FGF detected by immunohistochemistry in esophageal tissues and in PBMC was correlated with low levels of pro-apoptotic factors (Fas, Caspase 8) in PBMC from EoE subjects. Plasma-derived bFGF was shown to be the most elevated and most specific in EoE subjects in comparison to healthy controls and disease control subjects.</p> <p>Conclusion</p> <p>We describe for the first time a possible mechanism by which increased FGF is associated with inhibiting apoptosis in local esophageal tissues of EoE subjects as compared to controls. Eotaxin and FGF signaling pathways share activation through the ERK pathway; together, they could act to increase eosinophil activation and prolong the half-life of eosinophils in local tissues of the esophagus in EoE subjects.</p

Combinations of β-lactam or aminoglycoside antibiotics with plectasin are synergistic against methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

Bacterial infections remain the leading killer worldwide which is worsened by the continuous emergence of antibiotic resistance. In particular, methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and the latter can be difficult to treat. The traditional strategy of novel therapeutic drug development inevitably leads to emergence of resistant strains, rendering the new drugs ineffective. Therefore, rejuvenating the therapeutic potentials of existing antibiotics offers an attractive novel strategy. Plectasin, a defensin antimicrobial peptide, potentiates the activities of other antibiotics such as β-lactams, aminoglycosides and glycopeptides against MSSA and MRSA. We performed in vitro and in vivo investigations to test against genetically diverse clinical isolates of MSSA (n = 101) and MRSA (n = 115). Minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. The effects of combining plectasin with β-lactams, aminoglycosides and glycopeptides were examined using the chequerboard method and time kill curves. A murine neutropenic thigh model and a murine peritoneal infection model were used to test the effect of combination in vivo. Determined by factional inhibitory concentration index (FICI), plectasin in combination with aminoglycosides (gentamicin, neomycin or amikacin) displayed synergistic effects in 76-78% of MSSA and MRSA. A similar synergistic response was observed when plectasin was combined with β-lactams (penicillin, amoxicillin or flucloxacillin) in 87-89% of MSSA and MRSA. Interestingly, no such interaction was observed when plectasin was paired with vancomycin. Time kill analysis also demonstrated significant synergistic activities when plectasin was combined with amoxicillin, gentamicin or neomycin. In the murine models, plectasin at doses as low as 8 mg/kg augmented the activities of amoxicillin and gentamicin in successful treatment of MSSA and MRSA infections. We demonstrated that plectasin strongly rejuvenates the therapeutic potencies of existing antibiotics in vitro and in vivo. This is a novel strategy that can have major clinical implications in our fight against bacterial infections

Dietary Proteins as Determinants of Metabolic and Physiologic Functions of the Gastrointestinal Tract

Dietary proteins elicit a wide range of nutritional and biological functions. Beyond their nutritional role as the source of amino acids for protein synthesis, they are instrumental in the regulation of food intake, glucose and lipid metabolism, blood pressure, bone metabolism and immune function. The interaction of dietary proteins and their products of digestion with the regulatory functions of the gastrointestinal (GI) tract plays a dominant role in determining the physiological properties of proteins. The site of interaction is widespread, from the oral cavity to the colon. The characteristics of proteins that influence their interaction with the GI tract in a source-dependent manner include their physico-chemical properties, their amino acid composition and sequence, their bioactive peptides, their digestion kinetics and also the non-protein bioactive components conjugated with them. Within the GI tract, these products affect several regulatory functions by interacting with receptors releasing hormones, affecting stomach emptying and GI transport and absorption, transmitting neural signals to the brain, and modifying the microflora. This review discusses the interaction of dietary proteins during digestion and absorption with the physiological and metabolic functions of the GI tract, and illustrates the importance of this interaction in the regulation of amino acid, glucose, lipid metabolism, and food intake

An explainable model of host genetic interactions linked to COVID-19 severity

We employed a multifaceted computational strategy to identify the genetic factors contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing (WES) dataset of a cohort of 2000 Italian patients. We coupled a stratified k-fold screening, to rank variants more associated with severity, with the training of multiple supervised classifiers, to predict severity based on screened features. Feature importance analysis from tree-based models allowed us to identify 16 variants with the highest support which, together with age and gender covariates, were found to be most predictive of COVID-19 severity. When tested on a follow-up cohort, our ensemble of models predicted severity with high accuracy (ACC = 81.88%; AUCROC = 96%; MCC = 61.55%). Our model recapitulated a vast literature of emerging molecular mechanisms and genetic factors linked to COVID-19 response and extends previous landmark Genome-Wide Association Studies (GWAS). It revealed a network of interplaying genetic signatures converging on established immune system and inflammatory processes linked to viral infection response. It also identified additional processes cross-talking with immune pathways, such as GPCR signaling, which might offer additional opportunities for therapeutic intervention and patient stratification. Publicly available PheWAS datasets revealed that several variants were significantly associated with phenotypic traits such as "Respiratory or thoracic disease", supporting their link with COVID-19 severity outcome.A multifaceted computational strategy identifies 16 genetic variants contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing dataset of a cohort of Italian patients

Geographical Variability in the Likelihood of Bloodstream Infections Due to Gram-Negative Bacteria: Correlation with Proximity to the Equator and Health Care Expenditure (vol 9, e114548, 2014)

Hosp Univ Austral, Div Infect Dis Prevent & Infect Control Serv, Buenos Aires, DF, ArgentinaHosp Univ Austral, Microbiol Lab, Buenos Aires, DF, ArgentinaMonash Hlth, Monash Infect Dis, Clayton, Vic, AustraliaWollongong Hosp, Wollongong, NSW, AustraliaUniversidade Federal de São Paulo, Div Infect Dis, Lab Especial Microbiol Clin, São Paulo, BrazilHosp Israelita Albert Einstein, São Paulo, BrazilVirginia Commonwealth Univ, Med Ctr, Richmond, VA USAHosp Rim & Hipertensao, São Paulo, BrazilHosp Santa Casa Porto Alegre, Porto Alegre, RS, BrazilHosp Conceicao, Porto Alegre, RS, BrazilHosp Walter Cantidio, Fortaleza, Ceara, BrazilHosp Diadema, São Paulo, BrazilHosp Espanhol, Salvador, BA, BrazilHosp Clin Goiania, Goiania, Go, BrazilMt Sinai Hosp, Toronto, ON M5G 1X5, CanadaUniv Alberta, Div Infect Dis, Edmonton, AB, CanadaCairo Univ Kasr Ainy, Dar Al Fouad Hosp, Fac Med, Dept Clin Pathol, Cairo, EgyptHygeia Gen Hosp, Athens, GreeceUniv Tubingen Hosp, Internal Med, Div Infect Dis, Tubingen, GermanyTokyo Metropolitan Tama Med Ctr, Dept Infect Prevent, Tokyo, JapanAmphia Hosp Breda, Lab Microbiol & Infect Control, Breda, NetherlandsThammasat Univ Hosp, Div Infect Dis, Pathum Thani, ThailandSt John Hosp & Med Ctr, Infect Prevent & Control Dept, Grosse Pointe Woods, MI USAUniv Hosp Bern, Dept Infect Dis, CH-3010 Bern, SwitzerlandUniv Bern, Bern, SwitzerlandBarnes Jewish Hosp, St Louis, MO 63110 USAUniversidade Federal de São Paulo, Div Infect Dis, Lab Especial Microbiol Clin, São Paulo, BrazilWeb of Scienc

Genetic mechanisms of critical illness in COVID-19.

Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease