Pulmonary Co-Infections Detected Premortem Underestimate Postmortem Findings in a COVID-19 Autopsy Case Series.

Bacterial and fungal co-infections are reported complications of coronavirus disease 2019 (COVID-19) in critically ill patients but may go unrecognized premortem due to diagnostic limitations. We compared the premortem with the postmortem detection of pulmonary co-infections in 55 fatal COVID-19 cases from March 2020 to March 2021. The concordance in the premortem versus the postmortem diagnoses and the pathogen identification were evaluated. Premortem pulmonary co-infections were extracted from medical charts while applying standard diagnostic definitions. Postmortem co-infection was defined by compatible lung histopathology with or without the detection of an organism in tissue by bacterial or fungal staining, or polymerase chain reaction (PCR) with broad-range bacterial and fungal primers. Pulmonary co-infection was detected premortem in significantly fewer cases (15/55, 27%) than were detected postmortem (36/55, 65%; p < 0.0001). Among cases in which co-infection was detected postmortem by histopathology, an organism was identified in 27/36 (75%) of cases. Pseudomonas, Enterobacterales, and Staphylococcus aureus were the most frequently identified bacteria both premortem and postmortem. Invasive pulmonary fungal infection was detected in five cases postmortem, but in no cases premortem. According to the univariate analyses, the patients with undiagnosed pulmonary co-infection had significantly shorter hospital (p = 0.0012) and intensive care unit (p = 0.0006) stays and significantly fewer extra-pulmonary infections (p = 0.0021). Bacterial and fungal pulmonary co-infection are under-recognized complications in critically ill patients with COVID-19.

Commentary: Prevention of saphenous vein graft disease remains elusive.

One-year outcomes of Ticagrelor Antiplatelet Therapy to Reduce Graft Events and Thrombosis (TARGET), a randomized double-blinded clinical trial comparing post-coronary artery bypass surgery antiplatelet therapy with ticagrelor versus aspirin are published in this issue of the Journal. Although the authors did not detect statistically significant differences in their primary outcome (saphenous vein graft patency at 1 year) and major adverse cardiovascular events, their findings must be interpreted with caution given important limitations in the design and execution of the trial.

Love at First Click: Surgery Residency Websites in the Virtual Era.

INTRODUCTION: Frequently, a residency program's website is the first interaction students interested in surgery have with the program. In the setting of virtual interviews for residency in 2020, the online availability of program information is of heightened importance. We sought to assess how academic versus community-based general surgery residency programs compared with respect to certain details on their websites. METHODS: A total of n = 268 surgery residency programs were investigated. Our database of website characteristics included: direct link to residency website from the American Council on Graduate Medical Education (ACGME) program page, resident research requirement, listing of residents' publications, availability of residents' demographic information, program alumni information, board pass rates, attrition rate, detail of educational/academic activities, residents' evaluation methods, diversity, and mentorship. Inter-group analyses between academic and community-based programs were performed using Pearson's Chi-squared test. RESULTS: Academic and community-based general surgery residency program websites were compared based on twelve (12) different parameters. Statistically significant differences were observed for eight of these comparisons: direct website access from ACGME (p = 0.007), research highlighted (p < 0.001), resident research requirement (p = 0.002), resident demographic information available (p=0.004), alumni information (p = 0.005), resident evaluation methods (p = 0.016), diversity (p < 0.001), and mentorship (p = 0.012). Across these domains, academic programs had more information available on their websites than the community programs did. The program websites did not differ significantly based on the frequency of mentioning resident publications, board pass rate, attrition rate, or resident education. CONCLUSION: Many general surgery programs are lacking detailed information on their websites. The amount of website information available on general surgery residency programs differs when comparing academic and community-based programs.

Ultrasound-assisted catheter directed thrombolysis for pulmonary embolus during extracorporeal membrane oxygenation.

BACKGROUND: Acute pulmonary embolism (PE) is the third most common cause of cardiovascular death. For patients who are hemodynamically unstable, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support has been shown to provide hemodynamic stability, and allow time for definitive treatment and recovery. Ultrasound-assisted catheter directed thrombolysis (USAT) has the potential to be a safe adjunct and expedite right ventricular (RV) recovery for patients requiring VA-ECMO for PE. METHODS: A review of all VA-ECMO patients from January 2017 to September 2019 was performed. A total of 49 of these patients were cannulated due to a PE. USAT therapy was used as an adjunct in 6 (12%) of these patients. These 6 patients were given standardized USAT therapy with EKOs catheters at 1 mg/h of tissue plasminogen activator with an unfractionated heparin infusion for additional systemic anticoagulation. Outcomes, including in-hospital death, 90-day survival, RV recovery, and complications, were examined in the cohort of patients that received USAT as an adjunct to ECMO. RESULTS: Median age was 54 years old. Five of the six patients presented with a massive PE and had a PE severity score of Class V. One patient presented with a submassive PE with a Bova score of 2, but was cannulated to VA-ECMO in the setting of worsening RV function. All patients demonstrated recovery of RV function, were free from in-hospital death, and were alive at 90-day follow-up. CONCLUSION: Ekosonic endovascular system therapy may be a safe and feasible adjunct for patients on VA-ECMO for PE, and allow for survival with RV recovery with minimal complications.

A Retrospective Study of Infection in Patients Requiring Extracorporeal Membrane Oxygenation Support.

BACKGROUND: Healthcare-associated infections (HAIs) in critically ill patients are a serious public health problem. Extracorporeal membrane oxygenation (ECMO) has been used increasingly for patients with severe cardiac or respiratory failure, but it may increase HAI risk. The goal of our study was to characterize HAIs in ECMO patients at an ECMO referral center. METHODS: This institutional review board-approved study identified all consecutive adult ECMO patients admitted to the cardiac surgery intensive care unit (CSICU) between January 1, 2015, and December 31, 2017. Demographic data, diagnosis, ECMO cannulation technique, and survival were collected. Urinary tract infection, pneumonia, and bacteremia incidence during ECMO and within 3 months of decannulation were collected. Outcomes of patients with HAIs were compared with noninfected patients, the CSICU infection incidence, and overall Extracorporeal Life Support Organization survival data. RESULTS: There were 288 ECMO patients and 3396 CSICU admissions during this period. Survival was 72.3% for venoarterial ECMO, 85.3% for venovenous ECMO, and 57.1% for multimodality or veno-arteriovenous ECMO, with discharge survival of 60.2%, 72.0%, and 28.6%, respectively. Bacteremia incidence while cannulated was 6.8% for venoarterial ECMO and 9.3% for venovenous ECMO. Bacteremia occurred in 22 of 288 (7.6%) ECMO patients, compared with 48 of 3109 (1.5%) in non-ECMO CSICU patients, which was statistically significant (P < .002). Bacteremia and pneumonia were associated with decreased VA-ECMO survival, with prolonged overall requirements for ECMO support. CONCLUSIONS: Nosocomial ECMO infections are significantly higher than in other CSICU patients. Infection risk remains significant even after decannulation. Infection is associated with increased mortality and longer duration of ECMO support. Further efforts are needed to determine HAI reduction strategies in this high-risk patient population.

Trends in female surgeon authorship - The role of the middle author.

BACKGROUND: The objective of this study was to compare middle authorships between male and female general surgeons in the United States. METHODS: A stratified random sample of American College of Surgeons general surgery fellows was identified. Relevant author demographic, affiliation, and publication metrics were collected and compared across cohorts to determine which demographics were prognostic for each outcome variable. The primary endpoint was the number of middle author papers between genders. RESULTS: Males were more likely to enter into practice earlier (p<0.001), be fellowship-trained (p<0.001), obtain higher academic rank (p<0.001), and practice at more highly ranked academic institutions (p=0.019). Females had fewer middle author publications (p=0.044) and higher annual rates of first author publications (p=0.020) despite similar rates of total publications. CONCLUSIONS: Female surgeons hold the middle author position less frequently than males despite similar total publication numbers. Reasons for this finding should be the target of future study.

A porous collagen-GAG scaffold promotes muscle regeneration following volumetric muscle loss injury.

Volumetric muscle loss (VML) is a segmental loss of skeletal muscle which commonly heals with fibrosis, minimal muscle regeneration, and loss of muscle strength. Treatment options for these wounds which promote functional recovery are currently lacking. This study was designed to investigate whether the collagen-GAG scaffold (CGS) promotes functional muscle recovery following VML. A total of 66 C57/Bl6 mice were used in a three-stage experiment. First, 24 animals were split into three groups which underwent sham injury or unilateral quadriceps VML injury with or without CGS implantation. Two weeks post-surgery, muscle was harvested for histological and gene expression analysis. In the second stage, 18 mice underwent bilateral quadriceps VML injury, followed by weekly functional testing using a treadmill. In the third stage, 24 mice underwent sham or bilateral quadriceps VML injury with or without CGS implantation, with tissue harvested six weeks post-surgery for histological and gene expression analysis. VML mice treated with CGS demonstrated increased remnant fiber hypertrophy versus both the VML with no CGS and uninjured groups. Both VML groups showed greater muscle fiber hypertrophy than non-injured muscle. This phenomenon was still evident in the longer-term experiment. The gene array indicated that the CGS promoted upregulation of factors involved in promoting wound healing and regeneration. In terms of functional improvement, the VML mice treated with CGS ran at higher maximum speeds than VML without CGS. A CGS was shown to enhance muscle hypertrophy in response to VML injury with a resultant improvement in functional performance. A gene array highlighted increased gene expression of multiple growth factors following CGS implantation. This suggests that implantation of a CGS could be a promising treatment for VML wounds.

Pathogen-induced maternal effects result in enhanced immune responsiveness across generations.

Parental investment theory postulates that adults can accurately perceive cues from their surroundings, anticipate the needs of future offspring based on those cues, and selectively allocate nongenetic resources to their progeny. Such context-dependent parental contributions can result in phenotypically variable offspring. Consistent with these predictions, we show that bacterially exposed Manduca sexta mothers oviposited significantly more variable embryos (as measured by mass, volume, hatching time, and hatching success) relative to naïve and control mothers. By using an in vivo "clearance of infection" assay, we also show that challenged larvae born to heat-killed- or live-Serratia-injected mothers, supported lower microbial loads and cleared the infection faster than progeny of control mothers. Our data support the notion that mothers can anticipate the future pathogenic risks and immunological needs of their unborn offspring, providing progeny with enhanced immune protection likely through transgenerational immune priming. Although the inclusion of live Serratia into oocytes does not appear to be the mechanism by which mothers confer protection to their young, other mechanisms, including epigenetic modifications in the progeny due to maternal pathogenic stress, may be at play. The adaptive nature of maternal effects in the face of pathogenic stress provides insights into parental investment, resource allocation, and life-history theories and highlights the significant role that pathogen-induced maternal effects play as generators and modulators of evolutionary change.

Unraveling transcription factor interactions with heterochromatin protein 1 using fluorescence lifetime imaging microscopy and fluorescence correlation spectroscopy.

The epigenetic control of heterochromatin deposition is achieved through a network of protein interactions mediated by the heterochromatin protein 1 (HP1). In earlier studies, we showed that the CCAAT/enhancer-binding protein alpha (C/EBPα), a transcription factor that controls cell differentiation, localizes to heterochromatin, and interacts with HP1α. Here, deletion and mutagenesis are combined with live-cell imaging approaches to characterize these protein interactions. The results demonstrate that the basic region and leucine zipper (BZip) domain of C/EBPα is sufficient for the interaction with HP1α in regions of heterochromatin. Fluorescence correlation spectroscopy and cross-correlation (FCS and FCCS) revealed very different diffusion profiles for HP1α and the BZip protein, and co-expression studies indicated that the mobile fractions of these nuclear proteins diffuse independently of one another. The steady-state interactions of these proteins in regions of heterochromatin were monitored using Förster resonance energy transfer (FRET). A point mutation in HP1α, W174A, which disrupts the interactions with proteins containing the common PxVxL motif did not affect the interaction with the BZip protein. In contrast, the HP1α W41A mutation, which prevents binding to methylated histones, exhibited greatly reduced FRET efficiency when compared to the wild type HP1α or HP1αW174A. The functional significance of these interactions is discussed.

Monitoring protein interactions in living cells with fluorescence lifetime imaging microscopy.

Fluorescence lifetime imaging microscopy (FLIM) is now routinely used for dynamic measurements of signaling events inside single living cells, such as monitoring changes in intracellular ions and detecting protein-protein interactions. Here, we describe the digital frequency domain FLIM data acquisition and analysis. We describe the methods necessary to calibrate the FLIM system and demonstrate how they are used to measure the quenched donor fluorescence lifetime that results from Förster Resonance Energy Transfer (FRET). We show how the "FRET-standard" fusion proteins are used to validate the FLIM system for FRET measurements. We then show how FLIM-FRET can be used to detect the dimerization of the basic leucine zipper (B Zip) domain of the transcription factor CCAAT/enhancer binding protein α in the nuclei of living mouse pituitary cells. Importantly, the factors required for the accurate determination and reproducibility of lifetime measurements are described in detail.