Design and Implementation of a Learner-Centered Self-Paced Peritoneal Oncology Education Program.

BACKGROUND: Current educational programs for peritoneal surface malignancies (PSM) are unstructured and often target advanced learners. The authors describe the design and implementation of a structured, self-paced course at a high-volume PSM center. METHODS: In 2020, a learner-centered course was designed using the Canvas educational platform in consultation with the Center for Teaching at the University of Chicago. The course consisted of disease-site-specific modules, perioperative care pathways, in-built voluntary quizzes, and multimedia supplements for advanced learners. Trainees were provided access during the PSM service rotation, and engagement was compared across training levels by measuring the time spent online. RESULTS: Course design and management required 71 h between 2020 and 2022, with the majority of time spent in the design phase. During 3 years, 62 personnel (21 [34%] medical students, 28 [45%] residents, 8 [13%] staff, and 5 [8%] fellows) were assigned the course. The overall engagement rate was 83.9% (86% of medical students, 75% of residents, 100% of staff and fellows), and the median time spent online was 12.4 min/week (interquartile range [IQR], 2.1-53.0 min/week). Fourth-year medical students and clinical fellows spent more time online than other learners (73 min/week [IQR, 24.5-100 min/week] vs 13.3 min/week [IQR, 7.3-26.5 min/week]) (p = 0.001). CONCLUSIONS: The design and implementation of a PSM-specific course was feasible and sustainable using an online learning platform. Higher engagement was noted among invested learners. Non-technical factors for reduced engagement need to be ascertained further to improve the next iteration of this course.

Defining Microbiome Readiness for Surgery: Dietary Prehabilitation and Stool Biomarkers as Predictive Tools to Improve Outcome.

OBJECTIVES: Determine whether preoperative dietary prehabilitation with a low-fat, high-fiber diet reverses the impact of Western diet (WD) on the intestinal microbiota and improves postoperative survival. BACKGROUND: We have previously demonstrated that WD fed mice subjected to an otherwise recoverable surgical injury (30% hepatectomy), antibiotics, and a short period of starvation demonstrate reduced survival (29%) compared to mice fed a low-fat, high-fiber standard chow (SD) (100%). METHODS: Mice were subjected to 6 weeks of a WD and underwent dietary pre-habilitation (3 days vs 7 days) with a SD prior to exposure to antibiotics, starvation, and surgery. 16S rRNA gene sequencing was utilized to determine microbiota composition. Mass spectrometry measured short chain fatty acids and functional prediction from 16S gene amplicons were utilized to determine microbiota function. RESULTS: As early as 24 hours, dietary prehabilitation of WD mice resulted in restoration of bacterial composition of the stool microbiota, transitioning from Firmicutes dominant to Bacteroidetes dominant. However, during this early pre-habilitation (ie, 3 days), stool butyrate per microbial biomass remained low and postoperative mortality remained unchanged from WD. Microbiota function demonstrated reduced butyrate contributing taxa as potentially responsible for failed recovery. In contrast, after 7 days of prehabilitation (7DP), there was greater restoration of butyrate producing taxa and survival after surgery improved (29% vs 79% vs 100%: WD vs 7DP vs SD, P < 0.001). CONCLUSIONS: The deleterious effects of WD on the gut microbiota can be restored after 7 days of dietary prehabilitation. Moreover, stool markers may define the readiness of the microbiome to withstand the process of surgery including exposure to antibiotics and short periods of starvation.

Nonredundant roles of DIAPHs in primary ciliogenesis.

Primary cilia are hubs for several signaling pathways, and disruption in cilia function and formation leads to a range of diseases collectively known as ciliopathies. Both ciliogenesis and cilia maintenance depend on vesicle trafficking along a network of microtubules and actin filaments toward the basal body. The DIAPH (Diaphanous-related) family of formins promote both actin polymerization and microtubule (MT) stability. Recently, we showed that the formin DIAPH1 is involved in ciliogenesis. However, the role of other DIAPH family members in ciliogenesis had not been investigated. Here we show that depletion of either DIAPH2 or DIAPH3 also disrupted ciliogenesis and cilia length. DIAPH3 depletion also reduced trafficking within cilia. To specifically examine the role of DIAPH3 at the base, we used fused full-length DIAPH3 to centrin, which targeted DIAPH3 to the basal body, causing increased trafficking to the ciliary base, an increase in cilia length, and formation of bulbs at the tips of cilia. Additionally, we confirmed that the microtubule-stabilizing properties of DIAPH3 are important for its cilia length functions and trafficking. These results indicate the importance of DIAPH proteins in regulating cilia maintenance. Moreover, defects in ciliogenesis caused by DIAPH depletion could only be rescued by expression of the specific family member depleted, indicating nonredundant roles for these proteins.

The Biology of Anastomotic Healing-the Unknown Overwhelms the Known.

BACKGROUND: Anastomotic complications are among the most devastating consequences of gastrointestinal surgery. Despite its high morbidity, the factors responsible for anastomotic regeneration following surgical construction remain poorly understood. The aim of this review is to provide an overview of the typical and atypical factors that have been implicated in anastomotic healing. METHODS: A review and analysis of select literature on anastomotic healing was performed. RESULTS: The healing of an anastomotic wound mirrors the phases of cutaneous wound healing- inflammation, proliferation, and remodeling. The evidence supporting much of the traditional dogma for optimal anastomotic healing (ischemia, tension, nutrition) is sparse. More recent research has implicated atypical factors that influence anastomotic healing, including the microbiome, the mesentery, and geometry. As technology evolves, endoscopic approaches may improve anastomotic healing and in some cases may eliminate the anastomosis altogether. DISCUSSION: Much remains unknown regarding the mechanisms of anastomotic healing, and research should focus on elucidating the dynamics of healing at a molecular level. Doing so may help facilitate the transition from traditional surgical dogma to evidence-based medicine in the operating room.

Heme scavenging reduces pulmonary endoplasmic reticulum stress, fibrosis, and emphysema.

Pulmonary fibrosis and emphysema are irreversible chronic events after inhalation injury. However, the mechanism(s) involved in their development remain poorly understood. Higher levels of plasma and lung heme have been recorded in acute lung injury associated with several insults. Here, we provide the molecular basis for heme-induced chronic lung injury. We found elevated plasma heme in chronic obstructive pulmonary disease (COPD) (GOLD stage 4) patients and also in a ferret model of COPD secondary to chronic cigarette smoke inhalation. Next, we developed a rodent model of chronic lung injury, where we exposed C57BL/6 mice to the halogen gas, bromine (Br2) (400 ppm, 30 minutes), and returned them to room air resulting in combined airway fibrosis and emphysematous phenotype, as indicated by high collagen deposition in the peribronchial spaces, increased lung hydroxyproline concentrations, and alveolar septal damage. These mice also had elevated pulmonary endoplasmic reticulum (ER) stress as seen in COPD patients; the pharmacological or genetic diminution of ER stress in mice attenuated Br2-induced lung changes. Finally, treating mice with the heme-scavenging protein, hemopexin, reduced plasma heme, ER stress, airway fibrosis, and emphysema. This is the first study to our knowledge to report elevated heme in COPD patients and establishes heme scavenging as a potential therapy after inhalation injury.

The effects of tenure and promotion on surgeon productivity.

BACKGROUND: Studies investigating the impact of promotion and tenure on surgeon productivity are lacking. The aim of this study is to elucidate the relationship of promotion and tenure to surgeon productivity. METHODS: We reviewed data for the Department of Surgery at our institution. Relative value units (RVUs) billed per year, publications per year, and grant funding per year were used to assess productivity from 2010 to 2016. We analyzed tenure-track (TT) and non-tenure-track (NT) surgeons and compared the productivity within these groups by rank: assistant professor (ASST), associate professor (ASSOC), and full professor (FULL). Kruskal-Wallis and Mann-Whitney U tests were used to assess significance and relationships between the groups. RESULTS: A TT faculty was promoted if they produced more research, with the highest publication rates in TT FULL. TT faculty publishing rates increased from ASST to ASSOC (1 versus 2, P = 0.006) and from ASSOC to FULL (2 versus 4, P < 0.001). There were no differences in the low publication rates among NT ranks. Grant funding was also highest at the TT FULL level. The clinical production (RVUs) was highest between TT ASSOC and NT FULL. TT faculty increased productivity between ASST and ASSOC (7023 versus 8384, P = 0.001) and decreased between ASSOC and FULL (8384 versus 6877, P < 0.001). Among NT faculty, RVUs were stagnant between ASST and ASSOC levels (4877 versus 6313, P = 0.312) and increased between ASSOC and FULL levels (6313 versus 8975, P < 0.001). CONCLUSIONS: Tenure and nontenure pathways appear to appropriately incentivize surgical faculty over the course of their advancement. TT FULL has the highest research production and grant funding, whereas NT FULL has the highest clinical production.

Mechanisms and Treatment of Halogen Inhalation-Induced Pulmonary and Systemic Injuries in Pregnant Mice.

Inhalation of oxidant gases has been implicated in adverse outcomes in pregnancy, but animal models to address mechanisms and studies to identify potential pregnancy-specific therapies are lacking. Herein, we show that inhalation of bromine at 600 parts per million for 30 minutes by pregnant mice on the 15th day of embryonic development results in significantly lower survival after 96 hours than an identical level of exposure in nonpregnant mice. On the 19th embryonic day, bromine-exposed pregnant mice have increased systemic blood pressure, abnormal placental development, severe fetal growth restriction, systemic inflammation, increased levels of circulating antiangiogenic short fms-like tyrosine kinase-1, and evidence of pulmonary and cardiac injury. Treatment with tadalafil, an inhibitor of type 5 phosphodiesterase, by oral gavage 1 hour post-exposure and then once daily thereafter, attenuated systemic blood pressures, decreased inflammation, ameliorated pulmonary and cardiac injury, and improved maternal survival (from 36% to 80%) and fetal growth. These pathological changes resemble those seen in preeclampsia. Nonpregnant mice did not exhibit any of these pathological changes and were not affected by tadalafil. These findings suggest that pregnant women exposed to bromine may require particular attention and monitoring for signs of preeclampsia-like symptoms.

Role of apoptosis and autophagy in tuberculosis.

Tuberculosis (TB) is one of the oldest known human diseases and is transmitted by the bacteria Mycobacterium tuberculosis (Mtb). TB has a rich history with evidence of TB infections dating back to 5,800 bc TB is unique in its ability to remain latent in an individual for decades, with the possibility of later reactivation, causing widespread systemic symptoms. Currently, it is estimated that more than one-third of the world's population (~2 billion people) are infected with Mtb. Prolonged periods of therapy and complexity of treatment regimens, especially in active infection, have led to poor compliance in patients being treated for TB. Therefore, it is vitally important to have a thorough knowledge of the pathophysiology of Mtb to understand the disease progression, as well as to develop novel diagnostic tests and treatments. Alveolar macrophages represent both the primary host cell and the first line of defense against the Mtb infection. Apoptosis and autophagy of macrophages play a vital role in the pathogenesis and also in the host defense against Mtb. This review will outline the role of these two cellular processes in defense against Mtb with particular emphasis on innate immunity and explore developing therapies aimed at altering host responses to the disease.

Role of heme in bromine-induced lung injury.

Bromine (Br2 ) gas inhalation poses an environmental and occupational hazard resulting in high morbidity and mortality. In this review, we underline the acute lung pathology (within 24 h of exposure) and potential therapeutic interventions that may be utilized to mitigate Br2 -induced human toxicity. We discuss our latest published data, which suggest that an increase in heme-dependent tissue injury underlies the pathogenesis of Br2 toxicity. Our study was based on previous findings that demonstrated that Br2 upregulates the heme-degrading enzyme heme oxygenase-1 (HO-1), which converts toxic heme into bilverdin. Interestingly, following Br2 inhalation, heme levels were indeed elevated in bronchoalveolar lavage fluid, plasma, and whole lung tissue in C57BL/6 mice. High heme levels correlated with increased lung oxidative stress, lung inflammation, respiratory acidosis, lung edema, higher airway resistance, and mortality. However, therapeutic reduction of heme levels, by either scavenging with hemopexin or degradation by HO-1, improved lung function and survival. Therefore, heme attenuation may prove a useful adjuvant therapy to treat patients after Br2 exposure.

Chlorine-induced cardiopulmonary injury.

Chlorine (Cl2 ) is utilized worldwide for a diverse range of industrial applications, including pulp bleaching, sanitation, and pharmaceutical development. Though Cl2 has widespread use, little is known regarding the mechanisms of toxicity associated with Cl2 exposure, which occurs during industrial accidents or acts of terrorism. Previous instances of Cl2 exposure have led to reported episodes of respiratory distress that result in high morbidity and mortality. Furthermore, studies suggest that acute Cl2 exposure also results in systemic vascular injury and subsequent myocardial contractile dysfunction. Here, we review both lung and cardiac pathology associated with acute Cl2 inhalation and discuss recently published data that suggest that mitochondrial dysfunction underlies the pathogenesis of Cl2 -induced toxicity. Last, we discuss our findings that suggest that upregulation of autophagy protects against Cl2 -induced lung inflammation and can be a potential therapeutic target for ameliorating the toxic effects of Cl2 exposure.

Heme Attenuation Ameliorates Irritant Gas Inhalation-Induced Acute Lung Injury.

AIMS: Exposure to irritant gases, such as bromine (Br2), poses an environmental and occupational hazard that results in severe lung and systemic injury. However, the mechanism(s) of Br2 toxicity and the therapeutic responses required to mitigate lung damage are not known. Previously, it was demonstrated that Br2 upregulates the heme degrading enzyme, heme oxygenase-1 (HO-1). Since heme is a major inducer of HO-1, we determined whether an increase in heme and heme-dependent oxidative injury underlies the pathogenesis of Br2 toxicity. RESULTS: C57BL/6 mice were exposed to Br2 gas (600 ppm, 30 min) and returned to room air. Thirty minutes postexposure, mice were injected intraperitoneally with a single dose of the heme scavenging protein, hemopexin (Hx) (3 µg/gm body weight), or saline. Twenty-four hours postexposure, saline-treated mice had elevated total heme in bronchoalveolar lavage fluid (BALF) and plasma and acute lung injury (ALI) culminating in 80% mortality after 10 days. Hx treatment significantly lowered heme, decreased evidence of ALI (lower protein and inflammatory cells in BALF, lower lung wet-to-dry weight ratios, and decreased airway hyperreactivity to methacholine), and reduced mortality. In addition, Br2 caused more severe ALI and mortality in mice with HO-1 gene deletion (HO-1-/-) compared to wild-type controls, while transgenic mice overexpressing the human HO-1 gene (hHO-1) showed significant protection. INNOVATION: This is the first study delineating the role of heme in ALI caused by Br2. CONCLUSION: The data suggest that attenuating heme may prove to be a useful adjuvant therapy to treat patients with ALI.

Shc depletion stimulates brown fat activity in vivo and in vitro.

Adipose tissue is an important metabolic organ that integrates a wide array of homeostatic processes and is crucial for whole-body insulin sensitivity and energy metabolism. Brown adipose tissue (BAT) is a key thermogenic tissue with a well-established role in energy expenditure. BAT dissipates energy and protects against both hypothermia and obesity. Thus, BAT stimulation therapy is a rational strategy for the looming pandemic of obesity, whose consequences and comorbidities have a huge impact on the aged. Shc-deficient mice (ShcKO) were previously shown to be lean, insulin sensitive, and resistant to high-fat diet and obesity. We investigated the contribution of BAT to this phenotype. Insulin-dependent BAT glucose uptake was higher in ShcKO mice. Primary ShcKO BAT cells exhibited increased mitochondrial respiration; increased expression of several mitochondrial and lipid-oxidative enzymes was observed in ShcKO BAT. Levels of brown fat-specific markers of differentiation, UCP1, PRDM16, ELOVL3, and Cox8b, were higher in ShcKO BAT. In vitro, Shc knockdown in BAT cell line increased insulin sensitivity and metabolic activity. In vivo, pharmacological stimulation of ShcKO BAT resulted in higher energy expenditure. Conversely, pharmacological inhibition of BAT abolished the improved metabolic parameters, that is the increased insulin sensitivity and glucose tolerance of ShcKO mice. Similarly, in vitro Shc knockdown in BAT cell lines increased their expression of UCP1 and metabolic activity. These data suggest increased BAT activity significantly contributes to the improved metabolic phenotype of ShcKO mice.

Initial transfusion intensity predicts survival in myelodysplastic syndrome.

We evaluated 52 patients with myelodysplastic syndrome (MDS) who had received at least one red blood cell (RBC) transfusion. In the 4-week period following the first transfusion, 24 patients (group 1) required no transfusion, while 28 (group 2) required transfusion of two or more units of RBCs. Survival was greater in group 1 (440 weeks vs. 167 weeks, p < 0.01), even when only international prognostic scoring system (IPSS) low and intermediate-1 risk patients were analyzed (median overall survival 491 vs. 170 weeks, p < 0.05), independent of age, IPSS and progression to acute myeloid leukemia (AML). The intensity of transfusion required in the first few weeks after the first transfusion predicts disease severity and correlates with survival.

In vivo imaging of tracheal epithelial cells in mice during airway regeneration.

Many human lung diseases, such as asthma, chronic obstructive pulmonary disease, bronchiolitis obliterans, and cystic fibrosis, are characterized by changes in the cellular composition and architecture of the airway epithelium. Intravital fluorescence microscopy has emerged as a powerful approach in mechanistic studies of diseases, but it has been difficult to apply this tool for in vivo respiratory cell biology in animals in a minimally invasive manner. Here, we describe a novel miniature side-view confocal probe capable of visualizing the epithelium in the mouse trachea in vivo at a single-cell resolution. We performed serial real-time endotracheal fluorescence microscopy in live transgenic reporter mice to view the three major cell types of the large airways, namely, basal cells, Clara cells, and ciliated cells. As a proof-of-concept demonstration, we monitored the regeneration of Clara cells over 18 days after a sulfur dioxide injury. Our results show that in vivo tracheal microscopy offers a new approach in the study of altered, regenerating, or metaplastic airways in animal models of lung diseases.

Shc proteins influence the activities of enzymes involved in fatty acid oxidation and ketogenesis.

OBJECTIVES: ShcKO mice have low body fat and resist weight gain on a high fat diet, indicating that Shc proteins may influence enzymes involved in ß-oxidation. To investigate this idea, the activities of ß-oxidation and ketone body metabolism enzymes were measured. METHODS: The activities of ß-oxidation enzymes (acyl-CoA dehydrogenase, 3-hydroxyacyl-CoA dehydrogenase and ketoacyl-CoA thiolase) in liver and hindlimb skeletal muscle, ketolytic enzymes (acetoacetyl-CoA thiolase, ß-hydroxybutyrate dehydrogenase and 3-oxoacid-CoA transferase) in skeletal muscle, and ketogenic enzymes (acetoacetyl-CoA thiolase and ß-hydroxybutyrate dehydrogenase) in liver were measured from wild-type and ShcKO mice. RESULTS: The activities of ß-oxidation enzymes were increased (P<.05) in the ShcKO compared to wild-type mice in the fasted but not the fed state. In contrast, no uniform increases in the ketolytic enzyme activities were observed between ShcKO and wild-type mice. In liver, the activities of ketogenic enzymes were increased (P<.05) in ShcKO compared to wild-type mice in both the fed and fasted states. Levels of phosphorylated hormone sensitive lipase from adipocytes were also increased (P<.05) in fasted ShcKO mice. CONCLUSION: These studies indicate that the low Shc levels in ShcKO mice result in increased liver and muscle ß-oxidation enzyme activities in response to fasting and induce chronic increases in the activity of liver ketogenic enzymes. Decreases in the level of Shc proteins should be considered as possible contributors to the increase in activity of fatty acid oxidation enzymes in response to physiological conditions which increase reliance on fatty acids as a source of energy.

The Shc locus regulates insulin signaling and adiposity in mammals.

Longevity of a p66Shc knockout strain (ShcP) was previously attributed to increased stress resistance and altered mitochondria. Microarrays of ShcP tissues indicated alterations in insulin signaling. Consistent with this observation, ShcP mice were more insulin sensitive and glucose tolerant at organismal and tissue levels, as was a novel p66Shc knockout (ShcL). Increasing and decreasing Shc expression in cell lines decreased and increased insulin sensitivity, respectively - consistent with p66Shc's function as a repressor of insulin signaling. However, differences between the two p66Shc knockout strains were also observed. ShcL mice were fatter and susceptible to fatty diets, and their fat was more insulin sensitive than controls. On the other hand, ShcP mice were leaner and resisted fatty diets, and their adipose was less insulin sensitive than controls. ShcL and ShcP strains are both highly inbred on the C57Bl/6 background, so we investigated gene expression at the Shc locus, which encodes three isoforms, p66, p52, and p46. Isoform p66 is absent in both strains; thus, the remaining difference to which to attribute the 'lean' phenotype is expression of the other two isoforms. ShcL mice have a precise deletion of p66Shc and normal expression of p52 and p46Shc isoforms in all tissues; thus, a simple deletion of p66Shc results in a 'fat' phenotype. However, ShcP mice in addition to p66Shc deletion have a fourfold increase in p46Shc expression in white fat. Thus, p46Shc overexpression in fat, rather than p66Shc deletion, is the likely cause of decreased adiposity and reduced insulin sensitivity in the fat of ShcP mice, which has implications for the longevity of the strain.

Comparing prostate specific antigen triggers for intervention in men with stable prostate cancer on active surveillance.

PURPOSE: We determined the proportion of men with nonprogressive prostate cancer on active surveillance who had a trigger for treatment using various measures of prostate specific antigen kinetics. MATERIALS AND METHODS: A prospective phase II study of patients with favorable clinical parameters (stage T1b-T2b N0M0, Gleason sum 7 or less, prostate specific antigen 15 ng/ml or less) on active surveillance was initiated in 1995. Those patients considered at high risk for progression were offered radical intervention. The remaining patients were closely monitored and formed the cohort for this study. We calculated the proportion and frequency of patients who had a trigger for treatment based on the various prostate specific antigen triggers (prostate specific antigen doubling time, prostate specific antigen velocity, prostate specific antigen threshold). RESULTS: Of 450 patients followed on surveillance 305 remained on active surveillance without definitive intervention. None of these 305 patients have died of prostate cancer or have had symptomatic metastatic disease develop. Median followup was 6.8 years. The proportion of patients who would have had a trigger for treatment ranged from 14% to 42% for the threshold triggers, 37% to 50% for the prostate specific antigen doubling time triggers and 42% to 84% for the velocity triggers. CONCLUSIONS: Almost all of the prostate specific antigen triggers examined in this study would have led to high rates of trigger for treatment. More work is needed to identify a trigger that better strikes the balance between recommending treatment for patients at high risk for progression and minimizing treatment for those at low risk for progression.

Clinical results of long-term follow-up of a large, active surveillance cohort with localized prostate cancer.

PURPOSE We assessed the outcome of a watchful-waiting protocol with selective delayed intervention by using clinical prostate-specific antigen (PSA), or histologic progression as treatment indications for clinically localized prostate cancer. PATIENTS AND METHODS This was a prospective, single-arm, cohort study. Patients were managed with an initial expectant approach. Definitive intervention was offered to those patients with a PSA doubling time of less than 3 years, Gleason score progression (to 4 + 3 or greater), or unequivocal clinical progression. Survival analysis and Cox proportional hazard model were applied to the data. Results A total of 450 patients have been observed with active surveillance. Median follow-up was 6.8 years (range, 1 to 13 years). Overall survival was 78.6%. The 10-year prostate cancer actuarial survival was 97.2%. Overall, 30% of patients have been reclassified as higher risk and have been offered definitive therapy. Of 117 patients treated radically, the PSA failure rate was 50%, which was 13% of the total cohort. PSA doubling time of 3 years or less was associated with an 8.5-times higher risk of biochemical failure after definitive treatment compared with a doubling time of more than 3 years (P < .0001). The hazard ratio for nonprostate cancer to prostate cancer mortality was 18.6 at 10 years. CONCLUSION We observed a low rate of prostate cancer mortality. Among the patients who were reclassified as higher risk and who were treated, PSA failure was relatively common. Other-cause mortality accounted for almost all of the deaths. Additional studies are warranted to improve the identification of patients who harbor more aggressive disease despite favorable clinical parameters at diagnosis.