Effect of COVID-19 and its vaccines on surgical and postsurgical mortality, ICU admission and 90-day readmission for elective surgical procedures in a United States veteran population

BACKGROUND

We investigated how COVID-19 infection and vaccination impact elective surgical outcomes.

METHODS

We retrospectively compared pre-pandemic (P) veterans to those with COVID (C) more than three weeks preoperatively or no COVID (NC) history after carotid endarterectomy, CABG, hip replacement, or colectomy. Subgroup analysis considered vaccination. Age and sex propensity matching, and conditional logistic regression analyzed one-year-mortality, 90-day-readmission, and ICU requirements among 519 ​C, 1038 NC, and 2076 ​P, culled from 61,641 veterans.

RESULTS

NC, C, and P had similar ICU requirements and mortality, although NC required fewer readmissions. However, NC immunized at least once were readmitted and died less commonly than C who received at least one immunization.

CONCLUSIONS

SARS-CoV-2 history increased readmission without affecting ICU requirement or mortality. Further studies should evaluate whether the worse outcomes in postoperative patients with histories of both COVID infection and one vaccination reflect the effects of incomplete vaccination or dataset limitations.

A comparative case study illustrating the influence of a system perspective on the outcome evaluation of simple versus complex interventions

When evaluating the effectiveness of an intervention, the evaluation approach must match the intervention complexity, ensuring that the chosen evaluation is “fit for purpose.” For simple interventions, evaluating short-, mid-, and long-term outcomes is appropriate. However, for complex interventions, an additional outcome that must be considered is the essential system property that emerges as a result of the interaction of interdependent intervention components. By focusing on the emergent system property, evaluators are better able to assess the holistic effectiveness of a complex intervention. This article illustrates this principle through a comparative case study of a simple intervention and a complex intervention within a National Institute of Health (NIH) funded Clinical Translational Research center. The analysis illustrates that a more effective and appropriate evaluation results when a complex intervention, deemed to be operating and functioning as a system, is evaluated as a system than could have been achieved by treating each component as independent and evaluating the short-, mid-, or long-term outcomes of each component.

Schlafen 12 Slows TNBC Tumor Growth, Induces Luminal Markers, and Predicts Favorable Survival

The Schlafen 12 (SLFN12) protein regulates triple-negative breast cancer (TNBC) growth, differentiation, and proliferation. SLFN12 mRNA expression strongly correlates with TNBC patient survival. We sought to explore SLFN12 overexpression effects on in vivo human TNBC tumor xenograft growth and performed RNA-seq on xenografts to investigate related SLFN12 pathways. Stable SLFN12 overexpression reduced tumorigenesis, increased tumor latency, and reduced tumor volume. RNA-seq showed that SLFN12 overexpressing xenografts had higher luminal markers levels, suggesting that TNBC cells switched from an undifferentiated basal phenotype to a more differentiated, less aggressive luminal phenotype. SLFN12-overexpressing xenografts increased less aggressive BC markers, HER2 receptors ERBB2 and EGFR expression, which are not detectable by immunostaining in TNBC. Two cancer progression pathways, the NAD signaling pathway and the superpathway of cholesterol biosynthesis, were downregulated with SLFN12 overexpression. RNA-seq identified gene signatures associated with SLFN12 overexpression. Higher gene signature levels indicated good survival when tested on four independent BC datasets. These signatures behaved differently in African Americans than in Caucasian Americans, indicating a possible biological difference between these races that could contribute to the worse survival observed in African Americans with BC. These results suggest an increased SLFN12 expression modulates TNBC aggressiveness through a gene signature that could offer new treatment targets.

A novel drug-like water-soluble small molecule Focal Adhesion Kinase (FAK) activator promotes intestinal mucosal healing

Non-steroidal anti-inflammatory drugs (NSAIDs) injure the proximal and distal gut by different mechanisms. While many drugs reduce gastrointestinal injury, no drug directly stimulates mucosal wound healing. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, induces epithelial sheet migration. We synthesized and evaluated a water-soluble FAK-activating small molecule, M64HCl, with drug-like properties. Monolayer wound closure and Western blots measured migration and FAK phosphorylation in Caco-2 ​cells, in vitro kinase assays established FAK activation, and pharmacologic tests assessed drug-like properties. 30 ​mg/kg/day M64HCl was administered in two murine small intestine injury models for 4 days. M64HCl (0.1-1000 ​nM) dose-dependently increased Caco-2 FAK-Tyr 397 phosphorylation, without activating Pyk2 and accelerated Caco-2 monolayer wound closure. M64HCl dose-responsively activates the FAK kinase domain vs. the non-salt M64, increasing the V_max of ATP-binding. Pharmacologic tests suggested M64HCl has drug-like properties and is enterally absorbed. M64HCl 25 ​mg/kg/day continuous infusion promoted healing of ischemic jejunal ulcers and indomethacin-induced small intestinal injury in C57Bl/6 mice. M64HCl-treated mice exhibited smaller ulcers 4 days after ischemic ulcer induction or indomethacin injury. Renal histology and plasma creatinine were normal. Mild hepatic inflammatory changes and ALT elevation were similar among M64HCl-treated mice and controls. M64HCl was concentrated in kidney and gastrointestinal mucosa and functional nephrectomy studies suggested predominantly urinary excretion. Little toxicity was observed in vitro or in single-dose mouse toxicity studies until >1000x higher than effective concentrations. M64HCl, a water-soluble FAK activator, promotes epithelial restitution and intestinal mucosal healing and may be useful to treat gut mucosal injury.

ZINC40099027 promotes monolayer circular defect closure by a novel pathway involving cytosolic activation of focal adhesion kinase and downstream paxillin and ERK1/2

ZINC40099027 (ZN27) is a specific focal adhesion kinase (FAK) activator that promotes murine mucosal wound closure after ischemic or NSAID-induced injury. Diverse motogenic pathways involve FAK, but the direct consequences of pure FAK activation have not been studied, and how ZN27-induced FAK activation stimulates wound closure remained unclear. We investigated signaling and focal adhesion (FA) turnover after FAK activation by ZN27 in Caco-2 cells, confirming key results in CCD841 cells. ZN27 increased Caco-2 FAK-Y-397, FAK-Y-576/7, paxillin-Y-118, and ERK 1/2 phosphorylation and decreased FAK-Y-925 phosphorylation, without altering FAK-Y-861, p38, Jnk, or Akt phosphorylation. ZN27 increased FAK-paxillin interaction while decreasing FAK-Grb2 association. ZN27 increased membrane-associated FAK-Y-397 and FAK-Y-576/7 phosphorylation and paxillin-Y-118 and ERK 1/2 phosphorylation but decreased FAK-Y-925 phosphorylation without altering Src or Grb2. Moreover, ZN27 increased the fluorescence intensity of GFP-FAK and pFAK-Y397 in FAs and increased the total number of FAs but reduced their size in GFP-FAK-transfected Caco-2 cells, consistent with increased FA turnover. In contrast, FAK-Y397F transfection prevented ZN27 effects on FAK size and number and FAK and pFAK fluorescent intensity in FAs. We confirmed the proposed FAK/paxillin/ERK pathway using PP2 and U0126 to block Src and MEK1/2 in Caco-2 and CCD841 cells. These results suggest that ZN27 promotes intestinal epithelial monolayer defect closure by stimulating autophosphorylation of FAK in the cytosol, distinct from classical models of FAK activation in the FA. Phosphorylated FAK translocates to the membrane, where its downstream substrates paxillin and ERK are phosphorylated, leading to FA turnover and human intestinal epithelial cell migration.

RNA Sequencing of Intestinal Enterocytes Pre- and Post-Roux-en-Y Gastric Bypass Reveals Alteration in Gene Expression Related to Enterocyte Differentiation, Restitution, and Obesity with Regulation by Schlafen 12

Background: The intestinal lining renews itself in a programmed fashion that can be affected by adaptation to surgical procedures such as gastric bypass. Methods: To assess adaptive mechanisms in the human intestine after Roux-en-Y gastric bypass (RYGB), we biopsied proximal jejunum at the anastomotic site during surgery to establish a baseline and endoscopically re-biopsied the same area 6–9 months after bypass for comparison. Laser microdissection was performed on pre- and post-RYGB biopsies to isolate enterocytes for RNA sequencing. Results: RNA sequencing suggested significant decreases in gene expression associated with G2/M DNA damage checkpoint regulation of the cell cycle pathway, and significant increases in gene expression associated with the CDP-diacylglycerol biosynthesis pathway TCA cycle II pathway, and pyrimidine ribonucleotide salvage pathway after RYGB. Since Schlafen 12 (SLFN12) is reported to influence enterocytic differentiation, we stained mucosa for SLFN12 and observed increased SLFN12 immunoreactivity. We investigated SLFN12 overexpression in HIEC-6 and FHs 74 Int intestinal epithelial cells and observed similar increased expression of the following genes that were also increased after RYGB: HES2, CARD9, SLC19A2, FBXW7, STXBP4, SPARCL1, and UTS. Conclusions: Our data suggest that RYGB promotes SLFN12 protein expression, cellular mechanism and replication pathways, and genes associated with differentiation and restitution (HES2, CARD9, SLC19A2), as well as obesity-related genes (FBXW7, STXBP4, SPARCL1, UTS).

New Insights for Tracking and Reporting Milestones

Abstract: Despite being a common evaluation metric, milestones are poorly defined, and guidance for their use is underdeveloped in the evaluation literature. This practice note attempts to address this oversight by providing evaluation-specific guidance for tracking and reporting milestones. Using a case study, we share our initial approach to tracking and reporting milestones, as well as how critical reflection guided by the evaluation standards provided us with key insights that allowed us to make improvements to our initial process. We hope this practice note acts as a springboard for elevating the critical dialogue surrounding milestones in the evaluation literature.

Design and implementation of a core EPA-based acting internship curriculum

PURPOSE

The Association of American Medical Colleges published Core Entrustable Professional Activities (Core EPAs), expected independent clinical skills for first-day interns. We sought to determine whether a required acting internship (AI) in the fourth-year curriculum could be used for summative assessment of students' mastery of Core EPAs to a predefined level that would readily generalize across disciplines and campuses.

METHODS

The University of North Dakota School of Medicine and Health Sciences MD Program created a standardized, required Core EPA-based AI curriculum for multiple specialties at multiple geographic sites providing a final entrustability assessment for 10 EPAs in a single course.

RESULTS

The course was successfully designed and launched for all students in a single class. During the AI, students functioned at the level of an acting intern, rated the courses as superior, and performed at satisfactory exit-level competence for 10 Core EPAs.

CONCLUSIONS

A standardized, EPA-based AI curriculum can provide an opportunity for exit level EPA assessment in the medical curriculum. This model functions well within multiple specialties and at diverse community-based, volunteer faculty teaching sites.

Integrated secure messaging to enhance medical education: a mixed methods study

BACKGROUND

Instant messaging applications and texting are useful for educating and communicating with medical students; however, they present patient privacy concerns and do not address the challenge of student inclusion in patient care communication. EMR-integrated secure messaging offers an opportunity to include students on team communication, enhance their medical education, and ensure patient privacy.

METHODS

Between July 2019 through March 2020, we performed a mixed method study to evaluate use of EPIC® Secure Chat as a means of enhancing student education and team communication. We promoted use of secure messaging in orientation, performed a pre- and post-rotation survey to assess perceptions of Secure Chat effect on communication, and directly reviewed and categorized messages.

RESULTS

Twenty-four 3rd and 4th year students completed the pre-rotation survey, and 22 completed the post-rotation survey. Twelve (50%) students reported the quality of communication with faculty was either good or very good prior to internal medicine rotation, while 20 (91%) reported this post-rotation (p-value 0.001). There was a similar improvement in communication with ancillary staff. Nineteen (86%) students felt that secure messaging improved their communication with faculty. On message review, threads were frequently logistical, but also often included discussions of patient management.

CONCLUSIONS

Students viewed Secure Chat as having a favorable effect on their communication with team members and reported communication on internal medicine to be improved compared to prior rotations. Messages included students on important patient care conversations. Secure messaging offers a novel medium to improve team communication, enhance student education, and maintain patient privacy.

Evaluation Utility Metrics (EUMs) in Reflective Practice

The article proposes three evaluation utility metrics to assist evaluators in evaluating the quality of their evaluation. After an overview of reflective practice in evaluation, the different ways in which evaluators can hold themselves accountable are discussed. It is argued that reflective practice requires evaluators to go beyond evaluation quality (i.e., technical quality and methodological rigor) when assessing evaluation practice to include an evaluation of evaluation utility (i.e., specific actions taken in response to evaluation recommendations). Three Evaluation Utility Metrics (EUMs) are proposed to evaluate utility: whether recommendations are considered (EUM_c), adopted (EUM_a), and (if adopted) level of influence of recommendations (EUM_li). The authors then reflect on their experience in using the EUMs, noting the importance of managing expectations through negotiation to ensure EUM data is collected and the need to consider contextual nuances (e.g., adoption and influence of recommendations are influenced by multiple factors beyond the control of the evaluators). Recommendations for increasing EUM rates by paying attention to the frequency and timing of recommendations are also shared. Results of implementing these EUMs in a real-world evaluation provide evidence of their potential value: practice tips led to an EUM_c = 100% and EUM_a > 80%. Methods for considering and applying all three EUMs together to facilitate practice improvement are also discussed.

Day-to-day blood pressure variability predicts poor outcomes following percutaneous coronary intervention: A retrospective study

BACKGROUND

For patients with cardiovascular disease, blood pressure variability (BPV), distinct from hypertension, is an important determinant of adverse cardiac events. Whether pre-operative BPV adversely affects outcomes after percutaneous coronary intervention (PCI) is to this point unclear.

AIM

To investigate the relationship between blood pressure variability and outcomes for patients post-PCI.

METHODS

Patients undergoing PCI in a single state in 2017 were studied (n = 647). Systolic and diastolic BPV, defined as both the largest change and standard deviation for the 3-60 mo prior to PCI was calculated and patients with more than ten blood pressure measurements in that time were included for analysis (n = 471). Adverse outcomes were identified up to a year following the procedure, including major adverse cardiac events (MACE), myocardial infarction, cerebrovascular accident, death, and all-cause hospitalization.

RESULTS

Visit-to-visit systolic BPV, as measured by both standard deviation and largest change, was higher in patients who had myocardial infarction, were readmitted, or died within one year following PCI. Systolic BPV, as measured by largest change or standard deviation, was higher in patients who had MACE, or readmissions (P < 0.05). Diastolic BPV, as measured by largest change, was higher in patients with MACE and readmissions (P < 0.05).

CONCLUSION

As BPV is easily measured and captured in the electronic medical record, these findings describe a novel method of identifying at-risk patients who undergo PCI. Aggressive risk modification for patients with elevated BPV and known coronary artery disease is indicated.

Gut homeostasis, injury, and healing: New therapeutic targets

The integrity of the gastrointestinal mucosa plays a crucial role in gut homeostasis, which depends upon the balance between mucosal injury by destructive factors and healing via protective factors. The persistence of noxious agents such as acid, pepsin, nonsteroidal anti-inflammatory drugs, or Helicobacter pylori breaks down the mucosal barrier and injury occurs. Depending upon the size and site of the wound, it is healed by complex and overlapping processes involving membrane resealing, cell spreading, purse-string contraction, restitution, differentiation, angiogenesis, and vasculogenesis, each modulated by extracellular regulators. Unfortunately, the gut does not always heal, leading to such pathology as peptic ulcers or inflammatory bowel disease. Currently available therapeutics such as proton pump inhibitors, histamine-2 receptor antagonists, sucralfate, 5-aminosalicylate, antibiotics, corticosteroids, and immunosuppressants all attempt to minimize or reduce injury to the gastrointestinal tract. More recent studies have focused on improving mucosal defense or directly promoting mucosal repair. Many investigations have sought to enhance mucosal defense by stimulating mucus secretion, mucosal blood flow, or tight junction function. Conversely, new attempts to directly promote mucosal repair target proteins that modulate cytoskeleton dynamics such as tubulin, talin, Ehm², filamin-a, gelsolin, and flightless I or that proteins regulate focal adhesions dynamics such as focal adhesion kinase. This article summarizes the pathobiology of gastrointestinal mucosal healing and reviews potential new therapeutic targets.

SLFN12 Over-expression Sensitizes Triple Negative Breast Cancer Cells to Chemotherapy Drugs and Radiotherapy

BACKGROUND/AIM

Schlafen 12 (SLFN12) expression correlates with survival in triple negative breast cancer (TNBC). SLFN12 slows TNBC proliferation and induces TNBC differentiation, but whether SLFN12 affects the tumoral response to chemotherapy or radiation is unknown.

MATERIALS AND METHODS

We over-expressed SLFN12 in MDA-MB-231 cells using two different lentiviral vectors. We assessed viable cell numbers via crystal violet assay after treatment with carboplatin, paclitaxel, olaparib, zoledronic acid, camptothecin, or cesium irradiation. CHK1 and CHK2 phosphorylation was assessed by western blot and the effects of inhibiting CHK1/CHK2 by AZD7762 were examined. Key findings were confirmed in Hs578t and BT549 TNBC cells after adenoviral SLFN12 over-expression.

RESULTS

SLFN12 over-expression increased TNBC sensitivity to radiation, carboplatin, paclitaxel, zoledronic acid, and camptothecin, but not to olaparib. SLFN12 over-expression decreased CHK1 and CHK2 phosphorylation after treatment with the DNA damaging agent camptothecin (CPT). The CHK1/CHK2 inhibitor diminished the significant cytotoxicity difference between over-expression and baseline SLFN12 levels in response to carboplatin.

CONCLUSION

SLFN12 increases TNBC sensitivity to DNA-damaging agents at least in part by reducing CHK1/2 phosphorylation. This may contribute to improved survival in patients whose TNBC over-expresses SLFN12. Therefore, SLFN12 levels may be used to customize or predict radiotherapy and chemotherapy effects in TNBC.

Management of Malignant Pleural Effusions in U.S. Veterans: A Retrospective Review

PURPOSE

To compare malignant pleural effusion (MPE) treatment outcomes and complications among patients receiving indwelling pleural catheter (IPC), talc pleurodesis (TPS), or dual therapy. Outcomes were determined by measuring length of stay (LOS) and post-procedure dyspnea scores. Complications were measured by comparing intervention failures and adverse events.

METHODS

The Veterans Affairs' Corporate Data Warehouse was utilized to retrospectively review the charts of 314 MPE subjects. Dyspnea scores were estimated by researchers and LOS was determined by adding the duration of stay for all admissions post procedure. Complications were recorded through chart review.

RESULTS

IPC exhibited higher failure rates than the other approaches 1 year post intervention. Pneumonia/chest infection rate and lung entrapment were also more prevalent. There was no significant difference in dyspnea rates. LOS illustrated a significant difference between groups, with talc patients spending a median of 7 days in the hospital immediately post procedure, while IPC and IPC + TPS patients spent a median of 3 and 2 days, respectively.

CONCLUSION

Patients receiving IPC or combination treatment spend fewer days in the hospital than TPS patients. However, IPC appears to be associated with more adverse events and higher long-term failure rates than other management strategies.

Using the Homeland Security Exercise and Evaluation Program (HSEEP) Building Block Approach to Implement System Evaluation Theory (SET)

This article shares lessons learned in applying system evaluation theory (SET) to evaluate a Clinical and Translational Research Center (CTR) funded by the National Institutes of Health. After describing how CTR support cores are intended to work interdependently as a system, the case is made for SET as the best fit for evaluating this evaluand. The article then details how the evaluation was also challenged to facilitate a CTR culture shift, helping support cores to move from working autonomously to working together and understanding how the cores' individual operating processes impact each other. This was achieved by incorporating the Homeland Security Exercise and Evaluation Program (HSEEP) building block approach to implement SET. Each of the seven HSEEP building blocks is examined for alignment with each of SET's three steps and the ability to systematically support the goal of moving CTR cores toward working interdependently. The implications of using HSEEP to support SET implementation for future evaluations are discussed.

Characterizing Long COVID: Deep Phenotype of a Complex Condition

BACKGROUND

Numerous publications describe the clinical manifestations of post-acute sequelae of SARS-CoV-2 (PASC or "long COVID"), but they are difficult to integrate because of heterogeneous methods and the lack of a standard for denoting the many phenotypic manifestations. Patient-led studies are of particular importance for understanding the natural history of COVID-19, but integration is hampered because they often use different terms to describe the same symptom or condition. This significant disparity in patient versus clinical characterization motivated the proposed ontological approach to specifying manifestations, which will improve capture and integration of future long COVID studies.

METHODS

The Human Phenotype Ontology (HPO) is a widely used standard for exchange and analysis of phenotypic abnormalities in human disease but has not yet been applied to the analysis of COVID-19.

FUNDING

We identified 303 articles published before April 29, 2021, curated 59 relevant manuscripts that described clinical manifestations in 81 cohorts three weeks or more following acute COVID-19, and mapped 287 unique clinical findings to HPO terms. We present layperson synonyms and definitions that can be used to link patient self-report questionnaires to standard medical terminology. Long COVID clinical manifestations are not assessed consistently across studies, and most manifestations have been reported with a wide range of synonyms by different authors. Across at least 10 cohorts, authors reported 31 unique clinical features corresponding to HPO terms; the most commonly reported feature was Fatigue (median 45.1%) and the least commonly reported was Nausea (median 3.9%), but the reported percentages varied widely between studies.

INTERPRETATION

Translating long COVID manifestations into computable HPO terms will improve analysis, data capture, and classification of long COVID patients. If researchers, clinicians, and patients share a common language, then studies can be compared/pooled more effectively. Furthermore, mapping lay terminology to HPO will help patients assist clinicians and researchers in creating phenotypic characterizations that are computationally accessible, thereby improving the stratification, diagnosis, and treatment of long COVID.

FUNDING

U24TR002306; UL1TR001439; P30AG024832; GBMF4552; R01HG010067; UL1TR002535; K23HL128909; UL1TR002389; K99GM145411.

Vil-Cre specific Schlafen 3 knockout mice exhibit sex-specific differences in intestinal differentiation markers and Schlafen family members expression levels

The intestinal epithelium requires self-renewal and differentiation in order to function and adapt to pathological diseases such as inflammatory bowel disease, short gut syndrome, and ulcers. The rodent Slfn3 protein and the human Slfn12 analog are known to regulate intestinal epithelial differentiation. Previous work utilizing a pan-Slfn3 knockout (KO) mouse model revealed sex-dependent gene expression disturbances in intestinal differentiation markers, metabolic pathways, Slfn family member mRNA expression, adaptive immune cell proliferation/functioning genes, and phenotypically less weight gain and sex-dependent changes in villus length and crypt depth. We have now created a Vil-Cre specific Slfn3KO (VC-Slfn3KO) mouse to further evaluate its role in intestinal differentiation. There were increases in Slfn1, Slfn2, Slfn4, and Slfn8 and decreases in Slfn5 and Slfn9 mRNA expression that were intestinal region and sex-specific. Differentiation markers, sucrase isomaltase (SI), villin 1, and dipeptidyl peptidase 4 and glucose transporters, glucose transporter 1 (Glut1), Glut2, and sodium glucose transporter 1 (SGLT1), were increased in expression in VC-Slfn3KO mice based on intestinal region and were also highly female sex-biased, except for SI in the ileum was also increased for male VC-Slfn3KO mice and SGLT1 was decreased for both sexes. Overall, the variations that we observed in these VC-Slfn3KO mice indicate a complex regulation of intestinal gene expression that is sex-dependent.

Correlations Among Visit-to-Visit Blood Pressure Variability and Treatment With Antihypertensive Medication With Long-Term Adverse Outcomes in a Large Veteran Cohort

BACKGROUND

Blood pressure variability (BPV) is associated with adverse events (AEs) independently of hypertension. It has been suggested that calcium channel blockers (CCBs) may reduce BPV, and thus be particularly valuable in hypertensives with high BPV. We sought to investigate how CCB affect BPV progression and whether long-term adverse effects of BPV differ after CCB treatment than after treatment with other antihypertensives.

METHODS

We retrospectively analyzed 25,268 US veterans who had been followed for 3 years without hypertensive therapy, started on a single class of antihypertensive agents (thiazides, CCBs, ACE inhibitors, or beta blockers [BBs]), treated for 6 years, and then followed for 3 additional years. BPV was calculated as SD of systolic or diastolic blood pressures from at least 10 measurements over each 3-year period. A combined AE endpoint included hospitalization, coronary artery bypass grafting, carotid endarterectomy, angioplasty, amputation, arteriovenous fistula creation, and mortality was assessed in years 9-12.

RESULTS

Post-medication high BPV and BB or thiazide use were associated with increased AE risk. Medication type also affected mean post-medication BPV. The effects of medications except for BBs on AE and mortality was independent of the patient BPV.

CONCLUSIONS

The possible deleterious effects of thiazides should be considered within the context of the study population, who were mostly male and received only a single class of hypertensives. While CCB may ameliorate BPV over time, this study does not support choosing CCB over other agents specifically to lessen BPV-associated risk.

Microbiome diversity declines while distinct expansions of Th17, iNKT, and dendritic cell subpopulations emerge after anastomosis surgery

BACKGROUND

Anastomotic failure causes morbidity and mortality even in technically correct anastomoses. Initial leaks must be prevented by mucosal reapproximation across the anastomosis. Healing is a concerted effort between intestinal epithelial cells (IECs), immune cells, and commensal bacteria. IEC TLR4 activation and signaling is required for mucosal healing, leading to inflammatory factor release that recruits immune cells to limit bacteria invasion. TLR4 absence leads to mucosal damage from loss in epithelial proliferation, attenuated inflammatory response, and bacteria translocation. We hypothesize after anastomosis, an imbalance in microbiota will occur due to a decrease in TLR4 expression and will lead to changes in the immune milieu.

RESULTS

We isolated fecal content and small intestinal leukocytes from murine, Roux-en-Y and end-to-end anastomoses, to identify microbiome changes and subsequent alterations in the regulatory and pro-inflammatory immune cells 3 days post-operative. TLR4+ IECs were impaired after anastomosis. Microbiome diversity was reduced, with Firmicutes, Bacteroidetes, and Saccharibacteria decreased and Proteobacteria increased. A distinct TCRβhi CD4+ T cells subset after anastomosis was 10-20-fold greater than in control mice. 84% were Th17 IL-17A/F+ IL-22+ and/or TNFα+. iNKT cells were increased and TCRβhi. 75% were iNKT IL-10+ and 13% iNKTh17 IL-22+. Additionally, Treg IL-10+ and IL-22+ cells were increased. A novel dendritic cell subset was identified in anastomotic regions that was CD11bhi CD103mid and was 93% IL-10+.

CONCLUSIONS

This anastomotic study demonstrated a decrease in IEC TLR4 expression and microbiome diversity which then coincided with increased expansion of regulatory and pro-inflammatory immune cells and cytokines. Defining the anastomotic mucosal environment could help inform innovative therapeutics to target excessive pro-inflammatory invasion and microbiome imbalance.

Preoperative and Intraoperative Blood Pressure Variability Independently Correlate with Outcomes

BACKGROUND

Blood pressure variability (BPV) describes visit-to-visit blood pressure (BP) changes independent of hypertension. Preoperative BPV and intraoperative BPV are associated with increased postoperative outcomes. We investigated the impact of both preoperative BPV and intraoperative BPV on elective surgical outcomes, specifically whether preoperative BPV and intraoperative BPV were independent risk factors for surgical complications.

MATERIALS AND METHODS

We investigated 600 patients undergoing elective surgery lasting more than two h and who had ≥8 outpatient BP recordings over three preoperative years. Age, sex, ethnicity, BMI, current medical problems, and medications at time of surgery were recorded. BPV was calculated as the standard deviation (SD) of systolic or diastolic BP for the 369 valid patients. Average BPV were compared between adverse outcomes of readmission, wound infection, acute kidney injury, death, myocardial infarction, and cerebral vascular accident.

RESULTS

Three-hundred-sixty-nine (52.6% male, 47.4% female, 98.1% non-Hispanic) patients (mean age 62.5) were included in the study. Preoperative systolic (P = 0.043) and diastolic (P = 0.009) BPV were higher for patients with the combined endpoint of all adverse events. Preoperative systolic BPV was correlated with intraoperative BPV (P = 0.010). Both systolic and diastolic preoperative BPV was found to be independent from intraoperative BPV. Otolaryngology procedures were associated with less adverse outcomes (P = 0.034), whil antimicrobials (P = 0.022), autonomic drugs (P < 0.001), or respiratory drugs (P = 0.032) was associated with an increased likelihood of adverse outcome.

CONCLUSION

Preoperative DBPV is associated with increased risk of readmission, wound infection and the combined endpoint of all adverse events. Intraoperative systolic blood pressure variability (SPBV) is associated with increased risk of acute kidney injury and the combined endpoint of all adverse events. Preoperative DBPV and intraoperative SBPV are independent risk factors for ninety-d postoperative outcomes. BPV should be considered in individualized risk assessment when assessing patient eligibility for elective procedures.

ZINC40099027 activates human focal adhesion kinase by accelerating the enzymatic activity of the FAK kinase domain

Focal adhesion kinase (FAK) regulates gastrointestinal epithelial restitution and healing. ZINC40099027 (Zn27) activates cellular FAK and promotes intestinal epithelial wound closure in vitro and in mice. However, whether Zn27 activates FAK directly or indirectly remains unknown. We evaluated Zn27 potential modulation of the key phosphatases, PTP-PEST, PTP1B, and SHP2, that inactivate FAK, and performed in vitro kinase assays with purified FAK to assess direct Zn27-FAK interaction. In human Caco-2 cells, Zn27-stimulated FAK-Tyr-397 phosphorylation despite PTP-PEST inhibition and did not affect PTP1B-FAK interaction or SHP2 activity. Conversely, in vitro kinase assays demonstrated that Zn27 directly activates both full-length 125 kDa FAK and its 35 kDa kinase domain. The ATP-competitive FAK inhibitor PF573228 reduced basal and ZN27-stimulated FAK phosphorylation in Caco-2 cells, but Zn27 increased FAK phosphorylation even in cells treated with PF573228. Increasing PF573228 concentrations completely prevented activation of 35 kDa FAK in vitro by a normally effective Zn27 concentration. Conversely, increasing Zn27 concentrations dose-dependently activated kinase activity and overcame PF573228 inhibition of FAK, suggesting the direct interactions of Zn27 with FAK may be competitive. Zn27 increased the maximal activity (Vmax ) of FAK. The apparent Km of the substrate also increased under laboratory conditions less relevant to intracellular ATP concentrations. These results suggest that Zn27 is highly potent and enhances FAK activity via allosteric interaction with the FAK kinase domain to increase the Vmax of FAK for ATP. Understanding Zn27 enhancement of FAK activity will be important to redesign and develop a clinical drug that can promote mucosal wound healing.

Discovery of Novel Small-Molecule FAK Activators Promoting Mucosal Healing

Gastrointestinal mucosal wounds are common to patients injured by factors as diverse as drugs, inflammatory bowel disease, peptic ulcers, and necrotizing enterocolitis. However, although many drugs are used to ameliorate injurious factors, there is no drug available to actually stimulate mucosal wound healing. Focal adhesion kinase (FAK), a nonreceptor tyrosine kinase, induces epithelial sheet migration and wound healing, making FAK a potential pharmacological target in this regard. In our previous research, we found a lead compound with drug-like properties, ZINC40099027, which promotes FAK phosphorylation, inducing mucosal healing in murine models. Herein we describe the design and optimization of a small library of novel FAK activators based on ZINC40099027 and their applications toward human intestinal epithelial wound closure and mouse ulcer healing.

Loss of Slfn3 induces a sex-dependent repair vulnerability after 50% bowel resection

Bowel resection accelerates enterocyte proliferation in the remaining gut with suboptimal absorptive and digestive capacity because of a proliferation-associated decrease in functional differentiation markers. We hypothesized that although schlafen 3 (Slfn3) is an important regulator of enterocytic differentiation, Slfn3 would have less impact on bowel resection adaptation, where accelerated proliferation takes priority over differentiation. We assessed proliferation, cell shedding, and enterocyte differentiation markers from resected and postoperative bowel of wild-type (WT) and Slfn3-knockout (Slfn3KO) mice. Villus length and crypt depth were increased in WT mice and were even longer in Slfn3KO mice. Mitotic marker, Phh3+, and the proliferation markers Lgr5, FoxL1, and platelet-derived growth factor-α (PDGFRα) were increased after resection in male WT, but this was blunted in male Slfn3KO mice. Cell-shedding regulators Villin1 and TNFα were downregulated in female mice and male WT mice only, whereas Gelsolin and EGFR increased expression in all mice. Slfn3 expression increased after resection in WT mice, whereas other Slfn family members 1, 2, 5, 8, and 9 had varied expressions that were affected also by sex difference and loss of Slfn3. Differentiation markers sucrase isomaltase, Dpp4, Glut2, and SGLT1 were all decreased, suggesting that enterocytic differentiation effort is incompatible with rapid proliferation shift in intestinal adaptation. Slfn3 absence potentiates villus length and crypt depth, suggesting that the differentiating stimulus of Slfn3 signaling may restrain mucosal mass increase through regulating Villin1, Gelsolin, EGFR, TNFα, and proliferation markers. Therefore, Slfn3 may be an important regulator not only of "normal" enterocytic differentiation but also in response to bowel resection.NEW & NOTEWORTHY The differentiating stimulus of Slfn3 signaling restrains an increase in mucosal mass after bowel resection, and there is a Slfn3-sex interaction regulating differentiation gene expression and intestinal adaptation. This current study highlights the combinatory effects of gender and Slfn3 genotype on the gene expression changes that contribute to the adaptation in intestinal cellular milleu (i.e. villus and crypt structure) which are utilized to compensate for the stress-healing response that the animals display in intestinal adaptation.

Schlafen 12 Is Prognostically Favorable and Reduces C-Myc and Proliferation in Lung Adenocarcinoma but Not in Lung Squamous Cell Carcinoma

Schlafen 12 (SLFN12) is an intermediate human Schlafen that induces differentiation in enterocytes, prostate, and breast cancer. We hypothesized that SLFN12 influences lung cancer biology. We investigated survival differences in high versus low SLFN12-expressing tumors in two databases. We then adenovirally overexpressed SLFN12 (AdSLFN12) in HCC827, H23, and H1975 cells to model lung adenocarcinoma (LUAD), and in H2170 and HTB-182 cells representing lung squamous cell carcinoma (LUSC). We analyzed proliferation using a colorimetric assay, mRNA expression by RT-qPCR, and protein by Western blot. To further explore the functional relevance of SLFN12, we correlated SLFN12 with seventeen functional oncogenic gene signatures in human tumors. Low tumoral SLFN12 expression predicted worse survival in LUAD patients, but not in LUSC. AdSLFN12 modulated expression of SCGB1A1, SFTPC, HOPX, CK-5, CDH1, and P63 in a complex fashion in these cells. AdSLFN12 reduced proliferation in all LUAD cell lines, but not in LUSC cells. SLFN12 expression inversely correlated with expression of a myc-associated gene signature in LUAD, but not LUSC tumors. SLFN12 overexpression reduced c-myc protein in LUAD cell lines but not in LUSC, by inhibiting c-myc translation. Our results suggest SLFN12 improves prognosis in LUAD in part via a c-myc-dependent slowing of proliferation.

Primary care visits increase utilization of evidence-based preventative health measures

BACKGROUND

Primary care visits can serve many purposes and potentially influence health behaviors. Although previous studies suggest that increasing primary care provider numbers may be beneficial, the mechanism responsible for the association is unclear, and have not linked primary care access to specific preventative interventions. We investigated the association between the number of times patients accessed their primary care provider team and the likelihood they received selected preventative health interventions.

METHODS

Patients with complete data sets from Sanford Health were categorized based on the number of primary care visits they received in a specified time period and the preventative health interventions they received. Patient characteristics were used in a propensity analysis to control for variables. Relative risks and 95% confidence intervals were calculated to estimate the likelihood of obtaining preventative measures based on number of primary care visits compared with patients who had no primary care visits during the specified time period.

RESULTS

The likelihood of a patient receiving three specified preventative interventions was increased by 127% for vaccination, 122% for colonoscopy, and 75% for mammography if the patient had ≥ 1 primary care visit per year. More primary care visits correlated with increasing frequency of vaccinations, but increased primary care visits beyond one did not correlate with increasing frequency of mammography or colonoscopy.

CONCLUSIONS

One or more primary care visits per year is associated with increased likelihood of specific evidence-based preventative care interventions that improve longitudinal health outcomes and decrease healthcare costs. Increasing efforts to track and increase the number of primary care visits by clinics and health systems may improve patient compliance with select preventative measures.

Lessons Learned in Evaluating the Infrastructure of a Centre for Translational Research (CTR)

This paper shares lessons learned while evaluating the implementation of a Clinical and Translational Research Center (CTR). To meet its overarching goals the CTR consists of numerous research support units (e.g., biostats, community engagement, professional development, etc.) that are intended to work together collaboratively. It is then argued that an evaluation approach grounded in system thinking was the best fit to evaluate this key CTR design feature. The rationale for selecting Systems Evaluation Theory (SET) as the evaluation framework best suited to evaluate the CTR infrastructure is then presented. The application of SET and the lessons learned are then shared. The paper concludes that there are many similarly structured programs worldwide to which the lessons learned can be applied and upfront investments in using a system approach are rewarded by providing meaningful and useful evaluation recommendations for system change.

Preoperative outpatient blood pressure variability predicts postoperative mortality, readmission and morbidity after surgery

BACKGROUND

Outpatient blood pressure variability (BPV) predicts hospitalization and death in non-surgical patients independently of hypertension. We hypothesized that preoperative BPV predicts postoperative outcomes.

METHODS

We assessed 22,233 veterans undergoing CABG, colectomy, hip replacement, pancreatectomy, carotid endarterectomy or AV-fistula with ≥10 outpatient BP's over three preoperative years. Calculating BPV as SD of systolic or diastolic BP, we used logistic regression considering demographics, comorbidities, and pre-admission cardiovascular medications to estimate odds ratios for 90-day mortality or readmission, MI, CVA, renal failure, and wound infection, choosing the lowest 5%ile of systolic/diastolic BPV for reference.

RESULTS

Covariate-adjusted ORs for adverse outcomes increased as BPV increased. For instance, the highest 5%ile of systolic BPV had covariate-adjusted ORs of 2.96 and 1.78 for 90-day mortality and readmission. Systolic and diastolic BPV trended together but affected outcomes independently.

CONCLUSIONS

Preoperative BPV predicts postoperative outcomes. BPV should be considered in individualized risk assessment and subgroup risk stratification.

Loss of Schlafen3 influences the expression levels of Schlafen family members in ileum, thymus, and spleen tissue

Background

The Schlafen (Slfn) family proteins are important for regulation of cell growth, cell differentiation and cell cycle progression. We sought to distinguish Slfn family expression in Slfn3 knockout (KO) mice after RNA sequencing analysis of Slfn3KO vs. wildtype (WT) mice revealed varying expressions of Slfn family in ileal mucosa.

Methods

Quantitative PCR analysis of Slfn members was evaluated in ileal mucosa, thymus and spleen tissue since Slfn family members have roles in differentiating intestinal and immune cells.

Results

Ileal mucosa of Slfn3KO mice displayed a decrease in Slfn3, 4, 8 and 9 while Slfn1 and 5 increased in mRNA expression vs. WT mice. Thymic tissue had a Slfn9 increase and a Slfn4 decrease while splenic tissue had a Slfn8 and Slfn9 increase in Slfn3KO mice vs. WT mice. These differential expressions of Slfn members could indicate a feedback regulatory mechanism within the Slfn family. Indeed, MATCH^™ tool from geneXplain predicted that all Slfn members have regions in their promoters for the Kruppel-like factor-6 transcription factor. In addition, NFAT related factors, ING4, ZNF333 and KLF4 are also predicted to bind in up to 6 of the 8 Slfn promoters. This study further describes a possible autoregulatory mechanism amongst the Slfn family members which could be important in how they regulate the differentiation of various cell types.

Schlafen12 Reduces the Aggressiveness of Triple Negative Breast Cancer through Post-Transcriptional Regulation of ZEB1 That Drives Stem Cell Differentiation

BACKGROUND/AIMS

Schlafen12 (SLFN12) promotes human intestinal and prostatic epithelial differentiation. We sought to determine whether SLFN12 reduces triple-negative breast cancer (TNBC) aggressiveness.

METHODS

We validated bioinformatics analyses of publicly available databases by staining human TNBC. After virally overexpressing or siRNA-reducing SLFN12 in TNBC cell lines, we measured proliferation by CCK-8 assay, invasion into basement-membrane-coated pores, mRNA by q-RT-PCR and protein by Western blotting. Flow cytometry assessed proliferation and stem cell marker expression, and sorted CD44+/CD24- cells. Stemness was also assessed by mammosphere formation, and translation by click-it-AHA chemistry.

RESULTS

SLFN12 expression was lower in TNBC tumors and correlated with survival. SLFN12 overexpression reduced TNBC MDA-MB-231, BT549, and Hs578T proliferation. In MDA-MB-231 cells, AdSLFN12 reduced invasion, promoted cell cycle arrest, increased E-cadherin promoter activity, mRNA, and protein, and reduced vimentin expression and protein. SLFN12 knockdown increased vimentin. AdSLFN12 reduced the proportion of MDA-MB-231 CD44⁺CD24^- cells, with parallel differentiation changes. SLFN12 overexpression reduced MDA-MB-231 mammosphere formation. SLFN12 overexpression decreased ZEB1 and Slug protein despite increased ZEB1 and Slug mRNA in all three lines. SLFN12 overexpression accelerated MDA-MB-231 ZEB1 proteasomal degradation and slowed ZEB1 translation. SLFN12 knockdown increased ZEB1 protein. Coexpressing ZEB1 attenuated the SLFN12 effect on E-cadherin mRNA and proliferation in all three lines.

CONCLUSION

SLFN12 may reduce TNBC aggressiveness and improve survival in part by a post-transcriptional decrease in ZEB1 that promotes TNBC cancer stem cell differentiation.

Patient Preferences for Surgery or Antibiotics for the Treatment of Acute Appendicitis

Importance

Studies have compared surgical with nonsurgical therapy for acute uncomplicated appendicitis, but none of these studies have a patient-centered perspective.

Objectives

To evaluate how patients might choose between surgical and nonsurgical therapy for acute uncomplicated appendicitis and to identify targets to make antibiotic treatment more appealing.

Design, Setting, and Participants

This study comprised an online survey and an in-person sensitivity analysis survey. For the web survey, a convenience sample of 1728 respondents were asked to imagine that they or their child had acute uncomplicated appendicitis, provided information about laparoscopic and open appendectomy and antibiotic treatment alone, and asked which treatment they might choose. The web survey was open from April 17, 2016, through June 16, 2016, and was disseminated via email link, a poster with a Quick Response code, and social media. For the sensitivity analysis, 220 respondents were given the same scenario and options. Those who chose surgery were asked whether certain factors influenced their decision; each factor was incrementally improved during questioning about whether respondents would consider switching to antibiotics. These participants were recruited at public venues from June 3, 2016, to July 31, 2016. Web survey data were analyzed from June 17, 2016, to September 21, 2017. Sensitivity analysis data were analyzed from August 1, 2016, to September 21, 2017.

Main Outcomes and Measures

Treatment preferences.

Results

Among the 1728 web survey respondents, 1225 (70.9%) were female and 500 (28.9%) were male (3 [0.2%] either did not answer or responded as "gender fluid" within the comments section of the survey), and most self-reported being between 50 and 59 years of age (391 [22.6%]) and being non-Hispanic white (1563 [90.5%]). For themselves, 1482 respondents (85.8%) chose laparoscopic appendectomy, 84 (4.9%) chose open appendectomy, and 162 (9.4%) chose antibiotics alone. For their child, 1372 respondents (79.4%) chose laparoscopic appendectomy, 106 (6.1%) open appendectomy, and 250 (14.5%) antibiotics alone. Respondents were somewhat more likely to choose antibiotics for themselves if they had education beyond college (105 [12.6%]; P < .001), identified as other than non-Hispanic white (24 [14.9%]; P < .001), or did not know anyone who had previously been hospitalized (12 [15.8%]; P = .02), but they were less likely to choose antibiotics if they were surgeons (11 [5.4%]; P = .008). Of the 220 participants interviewed for the sensitivity analysis, 120 (54.5%) were female and 100 (45.5%) were male, and most self-reported being between 18 and 24 years of age (53 [24.1%]) and being non-Hispanic white (204 [92.7%]). Their responses suggested that improvements in the short- and long-term failure rate of antibiotic treatment-rather than reductions in the duration of hospitalization or antibiotic treatment-were more likely to increase the desirability of choosing antibiotics.

Conclusions and Relevance

Most patients may choose surgical intervention over antibiotics alone in treatment of acute uncomplicated appendicitis, but a meaningful number may choose nonoperative management. Therefore, from a patient-centered perspective, this option should be discussed with patients, and future research could be directed at reducing the failure and recurrence rates of antibiotic treatment for appendicitis.

Influences of sodium and glycosaminoglycans on skin oedema and the potential for ulceration: a finite-element approach

Venous ulcers are chronic transcutaneous wounds common in the lower legs. They are resistant to healing and have a 78% chance of recurrence within 2 years. It is commonly accepted that venous ulcers are caused by the insufficiency of the calf muscle pump, leading to blood pooling in the lower legs, resulting in inflammation, skin oedema, tissue necrosis and eventually skin ulceration. However, the detailed physiological events by which inflammation contributes to wound formation are poorly understood. We therefore sought to develop a model that simulated the inflammation, using it to determine the internal stresses and pressure on the skin that contribute to venous ulcer formation. A three-layer finite-element skin model (epidermis, dermis and hypodermis) was developed to explore the roles in wound formation of two inflammation identifiers: glycosaminoglycans (GAG) and sodium. A series of parametric studies showed that increased GAG and sodium content led to oedema and increased tissue stresses of 1.5 MPa, which was within the reported range of skin tissue ultimate tensile stress (0.1-40 MPa). These results suggested that both the oedema and increased fluid pressure could reach a threshold for tissue damage and eventual ulcer formation. The models presented here provide insights to the pathological events associated with venous insufficiency, including inflammation, oedema and skin ulceration.

Schlafen 3 knockout mice display gender-specific differences in weight gain, food efficiency, and expression of markers of intestinal epithelial differentiation, metabolism, and immune cell function

Self-renewal and differentiation are essential for intestinal epithelium absorptive functioning and adaptation to pathological states such as short gut syndrome, ulcers, and inflammatory bowel disease. The rodent Slfn3 and its human analog Slfn12 are critical in regulating intestinal epithelial differentiation. We sought to characterize intestinal function in Slfn3 knockout (KO) mice. Male and female pair-fed Slfn3KO mice gained less weight with decreased food efficiency than wild type (WT) mice, with more pronounced effects in females. RNA sequencing performed on intestinal mucosa of Slfn3KO and WT mice showed gene ontology decreases in cell adhesion molecule signaling, tumor necrosis factor receptor binding, and adaptive immune cell proliferation/functioning genes in Slfn3KO mice, with greater effects in females. qPCR analysis of fatty acid metabolism genes, Pla2g4c, Pla2g2f, and Cyp3c55 revealed an increase in Pla2g4c, and a decrease in Pla2g2f in Slfn3KO females. Additionally, adipogenesis genes, Fabp4 and Lpl were decreased and ketogenesis gene Hmgcs2 was increased in female Slfn3KO mice. Sequencing did not reveal significant changes in differentiation markers, so qPCR was utilized. Slfn3KO tended to have decreased expression of intestinal differentiation markers sucrase isomaltase, dipeptidyl peptidase 4, villin 1, and glucose transporter 1 (Glut1) vs. WT males, although these trends did not achieve statistical significance unless data from several markers was pooled. Differentiation markers, Glut2 and sodium-glucose transporter 1 (SGLT1), did show statistically significant sex-dependent differences. Glut2 mRNA was reduced in Slfn3KO females, while SGLT1 increased in Slfn3KO males. Notch2 and Cdx2 were only increased in female Slfn3KO mice. Although Slfn3KO mice gain less weight and decreased food efficiency, their biochemical phenotype is more subtle and suggests a complex interplay between gender effects, Slfn3, and another regulatory pathway yet to be identified that compensates for the chronic loss of Slfn3.

What Skills Do Clinical Evaluators Value Most In Oral Case Presentations?

Phenomenon: Trainees and practicing physicians are judged by the way that they present patients. We therefore invest heavily in teaching students how to do oral case presentations (OCPs), but the relative weights by which different aspects of these complex tasks contributes to an overall evaluation is poorly understood. Approach: We sought to contrast how clinical evaluators assess students' OCPs and how medical students expect OCPs to be evaluated. Multiple linear regression and correlation matrices assessed how individual components of 3rd-year medical students' OCPs affect overall faculty assessment of students' performance using the previously validated Patient Presentation Rating tool. Preclinical medical students were surveyed to determine how they expect their OCPs to be evaluated. Findings: Faculty evaluations of students' overall organization and descriptions of patients' situations and vital signs were strongly associated with their overall OCP evaluation. Students believed that describing the patient's situation, chief complaint, and history of present illness would be highly valued but not organization or vital signs descriptions. Insights: Students and faculty differ about what is important in OCPs. Aligning these perceptions through intentional redesign of curricula and feedback instruments may facilitate teaching clinical communication to students.

ZINC4085554 inhibits cancer cell adhesion by interfering with the interaction of Akt1 and FAK

Perioperative or circulatory forces enhance disseminated cancer cell adhesiveness by modulating focal adhesion kinase (FAK)-Akt1 interaction. Selectively blocking FAK-Akt1 interaction by a peptide derived from the FAK-Four-point-one, ezrin, radixin, moesin (FERM) domain reduces colon cancer cell adhesion in vitro and in mice. A preliminary in silico screening identified two small molecules resembling a peptide that may inhibit pressure-stimulated SW620 cancer cell adhesion to collagen I. The present study selected ZINC4085554 for further study to validate its proposed mechanism of action, using human SW620 colon cancer cells as a model system. At 25 and 50 µM, ZINC4085554 inhibited the pressure-stimulated adhesion of SW620 colon cancer cells to collagen I. This molecule prevented pressure-stimulated FAK-Tyr-397 phosphorylation; however, it did not affect Akt1-Ser-473 phosphorylation, indicating that ZINC4085554 acts downstream of Akt1, while Akt-Thr-308 remains unchanged in the presence of pressure and or ZINC4085554. Indeed, ZINC4085554 inhibited FAK-Akt1 interaction in response to increased extracellular pressure, consistent with the proposed mechanism. ZINC4085554 did not inhibit FAK-Tyr-397 phosphorylation in response to cell adhesion to collagen I, indicating the specificity of the inhibitory effects towards force-stimulated pathways. Finally, the present study confirmed that ZINC4085554 at 50 µM prevented pressure-activation of adhesion to surgical wounds in vivo in parallel to its ablation of intracellular signaling. In summary, ZINC4085554 is a small molecule mimicking part of the structure of FAK that reduces cancer cell adhesion by impairing pressure-stimulated FAK-Akt1 interaction and its downstream consequences. ZINC4085554 does not inhibit conventional outside-in FAK signaling and may be less toxic than global FAK inhibitors, and ZINC4085554 may be an important step towards the inhibition of metastasis.

Schlafen 12 mediates the effects of butyrate and repetitive mechanical deformation on intestinal epithelial differentiation in human Caco-2 intestinal epithelial cells

Intestinal epithelial differentiation may be stimulated by diverse pathways including luminal short-chain fatty acids and repetitive mechanical deformation engendered by villous motility and peristalsis. Schlafen 12 (SLFN12) is a cytosolic protein that stimulates sucrase-isomaltase (SI) expression. We hypothesized that two disparate differentiating stimuli, butyrate and repetitive deformation, would each stimulate SLFN12 expression in human Caco-2 intestinal epithelial cells and that increased SLFN12 expression would contribute to the differentiating activity of the human Caco-2 intestinal epithelial cells. We stimulated Caco-2 cells with 1-2 mM butyrate or repetitive mechanical deformation at 10 cycles/min at an average 10% strain, and measured SLFN12 and SI expression by qRT-PCR. Sodium butyrate enhanced SLFN12 expression at both 1 mM and 2 mM although SI expression was only significantly increased at 2 mM. Repetitive deformation induced by cyclic mechanical strain also significantly increased both SLFN12 and SI gene expression. Reducing SLFN12 by siRNA decreased basal, deformation-stimulated, and butyrate-stimulated SLFN12 levels, compared to control cells treated with non-targeting siRNA, although both deformation and butyrate were still able to stimulate SLFN12 expression in siRNA-treated cells compared to control cells treated with the same siRNA. This attenuation of the increase in SLFN12 expression in response to mechanical strain or butyrate was accompanied by parallel attenuation of SI expression. Butyrate stimulated SI-promoter activity, and reducing SLFN12 by siRNA attenuated butyrate-induced SI-promoter activity. These data suggest that SLFN12 mediates at least in part the stimulation by both butyrate and repetitive mechanical deformation of sucrase-isomaltase, a late stage differentiation marker in human intestinal epithelial cells.

Optimization of Protein-Protein Interaction Measurements for Drug Discovery Using AFM Force Spectroscopy

Increasingly targeted in drug discovery, protein-protein interactions challenge current high throughput screening technologies in the pharmaceutical industry. Developing an effective and efficient method for screening small molecules or compounds is critical to accelerate the discovery of ligands for enzymes, receptors and other pharmaceutical targets. Here, we report developments of methods to increase the signal-to-noise ratio (SNR) for screening protein-protein interactions using atomic force microscopy (AFM) force spectroscopy. We have demonstrated the effectiveness of these developments on detecting the binding process between focal adhesion kinases (FAK) with protein kinase B (Akt1), which is a target for potential cancer drugs. These developments include optimized probe and substrate functionalization processes and redesigned probe-substrate contact regimes. Furthermore, a statistical-based data processing method was developed to enhance the contrast of the experimental data. Collectively, these results demonstrate the potential of the AFM force spectroscopy in automating drug screening with high throughput.

Visit-to-Visit Variability of Blood Pressure Is Associated With Hospitalization and Mortality in an Unselected Adult Population

BACKGROUND

Blood pressure variability (BPV) has been associated with poor health outcomes in high-risk patients, but its association with more general populations is poorly understood.

METHODS

We analyzed outcomes from 240,622 otherwise unselected patients who had 10 or more outpatient blood pressure readings recorded over a 3-year period and were aged from 20 to 100 years.

RESULTS

Whether calculated as SD, average change, or greatest change and systolic or diastolic blood pressure, we found that higher outpatient BPV was associated with subsequent hospitalization and mortality. Systolic pressure average change exceeding 10-12 mm Hg or diastolic exceeding 8 mm Hg significantly increased risk of hospitalization and death (odds ratios [ORs] from 2.0 to 4.5). Variability in the highest decile increased risks even more dramatically, with propensity-matched ORs from 4.4 to 42. A systolic change exceeding 35 mm Hg increased the relative risk of death 4.5-fold. Similarly, a diastolic change greater than 23-24 mm Hg almost tripled the risks of hospitalization and death. Neither stratification for hypertension nor propensity matching for risk factors within the database affected these associations.

CONCLUSIONS

Systolic and diastolic variabilities were each associated with subsequent adverse outcomes. Physicians should pay special attention to patients with swings in blood pressure between clinic visits. Electronic medical records should flag such variability.

Schlafen 12 Interaction with SerpinB12 and Deubiquitylases Drives Human Enterocyte Differentiation

BACKGROUND/AIMS

Human enterocytic differentiation is altered during development, fasting, adaptation, and bariatric surgery, but its intracellular control remains unclear. We hypothesized that Schlafen 12 (SLFN12) regulates enterocyte differentiation.

METHODS

We used laser capture dissection of epithelium, qRT-PCR, and immunohistochemistry to evaluate SLFN12 expression in biopsies of control and fasting human duodenal mucosa, and viral overexpression and siRNA to trace the SLFN12 pathway in human Caco-2 and HIEC6 intestinal epithelial cells.

RESULTS

Fasting human duodenal mucosa expressed less SLFN12 mRNA and protein, accompanied by decreases in enterocytic markers like sucrase-isomaltase. SLFN12 overexpression increased Caco-2 sucrase-isomaltase promoter activity, mRNA, and protein independently of proliferation, and activated the SLFN12 putative promoter. SLFN12 coprecipitated Serpin B12 (SERPB12). An inactivating SLFN12 point mutation prevented both SERPB12 binding and sucrase-isomaltase induction. SERPB12 overexpression also induced sucrase-isomaltase, while reducing SERPB12 prevented the SLFN12 effect on sucrase-isomaltase. Sucrase-isomaltase induction by both SLFN12 and SERPB12 was attenuated by reducing UCHL5 or USP14, and blocked by reducing both. SERPB12 stimulated USP14 but not UCHL5 activity. SERPB12 coprecipitated USP14 but not UCHL5. Moreover, SLFN12 increased protein levels of the sucrase-isomaltase-promoter-binding transcription factor cdx2 without altering Cdx2 mRNA. This was prevented by reducing UCHL5 and USP14. We further validated this pathway in vitro and in vivo. SLFN12 or SERPB12 overexpression induced sucrase-isomaltase in human non-malignant HIEC-6 enterocytes.

CONCLUSIONS

SLFN12 regulates human enterocytic differentiation by a pathway involving SERPB12, the deubiquitylases, and Cdx2. This pathway may be targeted to manipulate human enterocytic differentiation in mucosal atrophy, short gut or obesity.

Identification of potential small-molecule protein-protein inhibitors of cancer metastasis by 3D epitope-based computational screening

In cancer cells exposed to extracellular pressure or shear stress, AKT1-FAK interaction drives focal adhesion kinase (FAK) phosphorylation, leading to force-activated cancer cell adhesion and metastasis. Blocking the AKT1-FAK interaction is therefore an attractive target for cancer therapy, avoiding the side effects of global FAK inhibition. Starting with our previous identification of a short FAK peptide that binds AKT1, we identified a series of small-molecule inhibitor candidates using a novel approach for inhibiting protein-protein interactions. Using a 3D structural fragment of the FAK peptide as the query, millions of drug-like, commercially available molecules were screened to identify a subset mimicking the volume and chemistry of the FAK fragment to test for their ability to block pressure-sensitive FAK phosphorylation by AKT1. Two compounds reduced the stimulation of FAK phosphorylation in response to extracellular pressure in human SW620 colon cancer cells without affecting basal FAK phosphorylation. Thus, using a 3D protein interaction epitope as a novel query for ligand-based virtual screening can successfully identify small-molecules that show promise in modulating cancer cell adhesion and metastasis.

Absence of Complications after Endoscopic Mucosal Biopsy

BACKGROUND

There is no clarity with regard to the occurrence of serious complications from EGD-driven mucosal biopsy. This is important for considering both clinically indicated procedures and mucosal sampling for research.

METHODS

We sought to quantify rates of serious complications from esophagogastroduodenoscopy (EGD) with biopsy. We studied 13,233 patients undergoing outpatient EGD with biopsy over 5 years in 2 North Dakota community hospitals, based on the reasoning that serious complications would cause hospitalization within 30 days. We reviewed the records of all patients with a diagnostic or procedure code or admission within 30 days after the outpatient EGD with biopsy.

RESULTS

Of the 13,233 patients who underwent outpatient EGD with biopsy, 411 were admitted within 30 days, most of them because of their underlying diagnosis. Two patients were admitted due to complications that resulted because of additional simultaneous procedures. No patient was admitted because of complications that could be ascribed to conscious sedation, upper GI endoscopic access, or mucosal biopsy.

CONCLUSIONS

These data confirm that EGD biopsy is safe within community settings and suggest that the risk/benefit ratio for performing EGD biopsy for research is likely to be favorable if the research has scientific merit. Serious complications or perforation following EGD biopsy did not occur in 13,233 patients in community hospitals in North Dakota.

P300 inhibition enhances gemcitabine-induced apoptosis of pancreatic cancer

The transcriptional cofactor p300 has histone acetyltransferase activity (HAT) and has been reported to participate in chromatin remodeling and DNA repair. We hypothesized that targeting p300 can enhance the cytotoxicity of gemcitabine, which induces pancreatic cancer cell apoptosis by damaging DNA. Expression of p300 was confirmed in pancreatic cancer cell lines and human pancreatic adenocarcinoma tissues by western blotting and immunohistochemistry. When pancreatic cancer cells were treated with gemcitabine, p300 was recruited to chromatin within 24 hours, indicating the role in response to DNA damage. When p300 was gene-silenced with siRNA, histone acetylation was substantially reduced and pancreatic cancer cells were sensitized to gemcitabine. The selective p300 HAT inhibitor C646 similarly decreased histone acetylation, increased gemcitabine-induced apoptosis and thus enhanced the cytotoxicity of gemcitabine on pancreatic cancer cells. These findings indicate that p300 contributes to chemo-resistance of pancreatic cancer against gemcitabine and suggest that p300 and its HAT activity may be a potential therapeutic target to improve outcomes in patients with pancreatic cancer.