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This study examined the casual sex behaviour and condom use of backpackers and other young international travellers (n=504) travelling in Canada in the summer of 2000. Twenty-six percent of all respondents reported that they had sexual intercourse with a casual partner (i.e. somebody they had just met) while on their current trip. Those who had casual sex while travelling were most often: male; had a history of casual sex prior to the trip; reported higher numbers of partners prior to the trip; expected to have casual sex on the trip; and were backpackers as opposed to short term travellers. While 94% expected to use a condom during casual sex while travelling, only 64% did so with their most recent casual partner. Perception of HIV risk was low among those who had casual sex and lower among those who did not. Factors most often cited as influences to have casual sex by those who did so were: (1) desire (being aroused, thinking about sex) or being desired (someone wanting to have sex with me); (2) alcohol use (drinking, being drunk) and mood enhancement (partying, 'have fun' mood); and (3) for men but not women, picking someone up or being picked up. Sex differences in these and other influences on casual sex behaviour while travelling are discussed in relation to the dynamics of casual sex behaviour and STI/HIV risk among young international travellers. [ABSTRACT FROM AUTHOR]

The biosynthesis of Pd nanoparticles supported on microorganisms (bio-Pd) is achieved via the enzymatic reduction of Pd(II) to Pd(0) under ambient conditions using inexpensive buffers and electron donors, like organic acids or hydrogen. Sustainable bio-Pd catalysts are effective for C-C coupling and hydrogenation reactions, but their industrial application is limited by challenges in controlling nanoparticle properties. Here, using the metal-reducing bacterium Geobacter sulfurreducens, it is demonstrated that synthesizing bio-Pd under different Pd loadings and utilizing different electron donors (acetate, formate, hydrogen, no e - donor) influences key properties such as nanoparticle size, Pd(II):Pd(0) ratio, and cellular location. Controlling nanoparticle size and location controls the activity of bio-Pd for the reduction of 4-nitrophenol, whereas high Pd loading on cells synthesizes bio-Pd with high activity, comparable to commercial Pd/C, for Suzuki-Miyaura coupling reactions. Additionally, the study demonstrates the novel synthesis of microbially-supported ≈2 nm PdO nanoparticles due to the hydrolysis of biosorbed Pd(II) in bicarbonate buffer. Bio-PdO nanoparticles show superior activity in 4-nitrophenol reduction compared to commercial Pd/C catalysts. Overall, controlling biosynthesis parameters, such as electron donor, metal loading, and solution chemistry, enables tailoring of bio-Pd physicochemical and catalytic properties., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Introduction: The tall cell, columnar, and diffuse sclerosing subtypes are aggressive histologic subtypes of papillary thyroid cancer (PTC) with increasing incidence, yet there is a wide variation in reporting. We aimed to identify and compare factors associated with the reporting of these aggressive subtypes (aPTC) to classic PTC (cPTC) and secondarily identify differences in outcomes., Methods: The National Cancer Database was utilized to identify cPTC and aPTC from 2004 to 2017. Patient and facility demographics and clinicopathologic variables were analyzed. Independent predictors of aPTC reporting were identified and a survival analysis was performed., Results: The majority of aPTC (67%) were reported by academic facilities. Compared to academic facilities, all other facility types were 1.4-2.0 times less likely to report aPTC (P < 0.05). Regional variation in reporting was noted, with more cases reported in the Middle Atlantic, despite there being more total facilities in the South Atlantic and East North Central regions. Compared to the Middle Atlantic, all other regions were 1.4-5 times less likely to report aPTC (P < 0.001). Patient characteristics including race and income were not associated with aPTC reporting. Compared to cPTC, aPTC had higher rates of aggressive features and worse 5-y overall survival (90.5% versus 94.5%, log rank P < 0.001)., Conclusions: Aggressive subtypes of PTC are associated with worse outcomes. Academic and other facilities in the Middle Atlantic were more likely to report aPTC. This suggests the need for further evaluation of environmental or geographic factors versus a need for increased awareness and more accurate diagnosis of these subtypes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Context: The significance of low mitotic activity in papillary thyroid cancer (PTC) is largely undefined., Objective: We aimed to determine the behavioral landscape of PTC with low mitotic activity compared to that of no- and high-mitotic activity., Methods: A single-institution consecutive series of PTC patients from 2018-2022 was reviewed. Mitotic activity was defined as no mitoses, low (1-2 mitoses/2 mm2) or high (≥3 mitoses/2 mm2) per the World Health Organization. The 2015 American Thyroid Association risk stratification was applied to the cohort, and clinicopathologic features were compared between groups. For patients with ≥6 months follow-up, Cox regression analyses for recurrence were performed., Results: 640 PTCs were included - 515 (80.5%) no mitotic activity, 110 (17.2%) low mitotic activity, and 15 (2.3%) high mitotic activity. Overall, low mitotic activity exhibited rates of clinicopathologic features including vascular invasion, gross extrathyroidal extension, and lymph node metastases in between those of no- and high-mitotic activity. PTCs with low mitotic activity had higher rates of intermediate- and high-risk ATA risk stratification compared to those with no mitotic activity (p < 0.001). Low mitotic activity PTCs also had higher recurrence rates (15.5% vs. 4.5%, p < 0.001). Low mitotic activity was associated with recurrence, independent of the ATA risk stratification (HR 2.96; 95% CI 1.28-6.87, p = 0.01)., Conclusions: Low mitotic activity is relatively common in PTC and its behavior lies within a spectrum between no- and high-mitotic activity. Given its association with aggressive clinicopathologic features and recurrence, low mitotic activity should be considered when risk stratifying PTC patients for recurrence., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: The complication rate of modern antireflux surgery or paraesophageal hernia repair is unknown, and previous estimates have been extrapolated from institutional cohorts., Methods: A population-based retrospective cohort study of patient injury cases involving antireflux surgery and paraesophageal hernia repair from the Finnish National Patient Injury Centre (PIC) register between Jan 2010 and Dec 2020. Additionally, the baseline data of all the patients who underwent antireflux and paraesophageal hernia operations between Jan 2010 and Dec 2018 were collected from the Finnish national care register., Results: During the study period, 5734 operations were performed, and the mean age of the patients was 54.9 ± 14.7 years, with 59.3% (n = 3402) being women. Out of all operations, 341 (5.9%) were revision antireflux or paraesophageal hernia repair procedures. Antireflux surgery was the primary operation for 79.9% (n = 4384) of patients, and paraesophageal hernia repair was the primary operation for 20.1% (n = 1101) of patients. A total of 92.5% (5302) of all the operations were laparoscopic. From 2010 to 2020, 60 patient injury claims were identified, with half (50.0%) of the claims being related to paraesophageal hernia repair. One of the claims was made due to an injury that resulted in a patient's death (1.7%). The mean Comprehensive Complication Index scores were 35.9 (± 20.7) and 47.6 (± 20.8) (p = 0.033) for antireflux surgery and paraesophageal hernia repair, respectively. Eleven (18.3%) of the claims pertained to redo surgery., Conclusions: The rate of antireflux surgery has diminished and the rate of paraesophageal hernia repair has risen in Finland during the era of minimally invasive surgery. Claims to the PIC remain rare, but claims regarding paraesophageal hernia repairs and redo surgery are overrepresented. Additionally, paraesophageal hernia repair is associated with more serious complications., (© 2023. The Author(s).)

Background: We aimed to evaluate the impact of radioactive iodine on disease-specific survival in intrathyroidal (N0M0) papillary thyroid carcinoma >4 cm, given conflicting data in the American Thyroid Association guidelines regarding their management., Methods: The Surveillance, Epidemiology, and End Results database was queried for N0M0 classic papillary thyroid carcinoma >4 cm. Kaplan-Meier estimates were performed to compare disease-specific survival between radioactive iodine-treated and untreated groups. A multivariable Cox regression was performed to identify predictors of disease-specific survival., Results: There were more patients aged ≥55 (41.7% vs 32.3%, P = .001) and fewer multifocal tumors (25.3% vs 30.6%, P = .006) in the no radioactive iodine group. Ten-year disease-specific survival was similar between the radioactive iodine treated and untreated groups (97.2% vs 95.6%, P = .34). Radioactive iodine was not associated with a significant disease-specific survival benefit (adjusted hazard ratio = 0.78, confidence interval [0.39-1.58], P = .49). Age ≥55 (adjusted hazard ratio = 3.50, confidence interval [1.69-7.26], P = .001) and larger tumor size (adjusted hazard ratio = 1.04, confidence interval [1.02-1.06], P < .001) were associated with an increased risk of disease-specific death. Subgroup analyses did not demonstrate improved disease-specific survival with radioactive iodine in patients ≥55 and in tumors >5 cm., Conclusion: Adjuvant radioactive iodine administration in classic papillary thyroid carcinoma >4 cm confined to the thyroid did not significantly impact disease-specific survival. Thus, these patients may not require routine treatment with adjuvant radioactive iodine., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Molecular testing guides the management of cytologically indeterminate thyroid nodules. We evaluated the real-world clinical benefit of a commercially available thyroid mutation panel plus microRNA risk classifier in classifying RAS-mutated nodules., Methods: We performed a subgroup analysis of the results of molecular testing of Bethesda III/IV nodules using the ThyGenX/ThyGeNEXT-ThyraMIR platform at 3 tertiary-care centers between 2017 and 2021, defining a positive result as 10% or greater risk of malignancy., Results: We identified 387 nodules from 375 patients (70.7% female, median age 59.3 years) who underwent testing. Positive nodules (32.3%) were associated with increased surgical intervention (74.4% vs 14.9%, P < .0001) and carcinoma on surgical pathology (46.4% vs 3.4%, P < .0001) compared to negative modules. RAS mutations were the most common mutations, identified in 71 of 380 (18.7%) nodules, and were classified as ThyraMIR- (28 of 71; 39.4%) or ThyraMIR+ (43 of 71; 60.6%). Among RAS-mutated nodules, there was no significant difference in operative rate (P = .2212) or carcinoma diagnosis (P = .6277) between the ThyraMIR+ and ThyraMIR- groups, and the sensitivity, specificity, negative predictive value, and positive predictive value of ThyraMIR were 64.7%, 34.8%, 40.0%, and 59.5%, respectively., Conclusion: Although testing positive is associated with malignancy in surgical pathology, the ThyraMIR classifier failed to differentiate between benign and malignant RAS-mutated nodules. Diagnostic lobectomy should be considered for RAS-mutated nodules, regardless of microRNA expression status., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Secondary hyperparathyroidism (sHPT) is prevalent in dialysis patients and can lead to tertiary hyperparathyroidism (tHPT) after kidney transplantation. We aimed to assess the association of pretransplant sHPT treatment on posttransplant outcomes., Methods: We reviewed kidney transplant patients treated with parathyroidectomy or cinacalcet for sHPT. We compared patients biochemical and clinical parameters, and outcomes based on sHPT treatment., Results: A total of 41 patients were included: 18 patients underwent parathyroidectomy and 23 patients received cinacalcet prior to transplantation. There were no significant differences between demographics, comorbidities, allograft characteristics or pre-sHPT intervention parathyroid hormone (PTH) and calcium levels. Patients that underwent parathyroidectomy were on dialysis for longer, although not significantly (71.9 versus 42.3 mo, P = 0.051). At time of transplantation, patients treated by parathyroidectomy had increased rates of controlled sHPT (88.9%; 16/18 versus 47.8%; 11/23, P = 0.008). Patients treated by parathyroidectomy had decreased development of tHPT (5.9%; 1/17; versus 42.1%; 8/19, P = 0.020) as well as decreased rates of posttransplant treatment with cinacalcet (11.1%; 2/18 versus 52.2%; 12/23, P = 0.008). Three patients treated with cinacalcet underwent parathyroidectomy after transplantation. Median PTH after transplant remained lower in patients treated by parathyroidectomy prior to transplant compared to those treated with cinacalcet (60.7 [interquartile range 39.7-133.4] versus 170.0 [interquartile range 128.4-292.7], P = 0.001). Allograft function and survival were similar for parathyroidectomy and cinacalcet, with median follow-up after transplantation of 56.7 and 34.2 mo, respectively., Conclusions: sHPT treated by parathyroidectomy is associated with controlled PTH levels at transplantation and decreased rates of tHPT. Long-term outcomes should be studied on a larger scale., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: We aimed to determine if there is an optimal time to complete dedicated research during surgical residency., Background: Research is an integral part of academic general surgical residency, and dedicated research usually occurs after the 2nd or 3rd post-graduate year (PGY). The timing of dedicated research and its association with resident productivity, self-assessed competency (including technical skills), and fellowship match is not known., Methods: PubMed was queried for publications resulting after dedicated research time for graduating surgical residents at a single institution from 2010 to 2021. Graduates were surveyed about their research experience and placed into 2 groups: research after PGY2 or PGY3., Results: Sixty-six of 91 (73%) graduating residents completed dedicated research (after PGY2, n=28; after PGY3, n=38). Median number of total and first author publications was similar between groups; however, research after PGY2 was associated with an increased number of basic science publications by fellowship application deadlines (PGY2: 1.0[0-13] vs PGY3: 0.0[0-6], p=0.02). With a 79% survey response rate, there were no differences in self-assessed competencies upon return from research between cohorts. Most surveyed residents matched at their top fellowship choice (PGY2:70% vs PGY3:62%, p=0.77)., Conclusions: Research after PGY2 or PGY3 had no association with residents' total number of publications, self-assessed competency, or rates of matching at first choice fellowship. As research after PGY2 had an increased number of basic science publications by time of fellowship application, surgical residents applying to fellowships that highly value basic science research may benefit from completing dedicated research after PGY2., (Copyright © 2023 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Perineural invasion (PNI) is associated with aggressive tumor behavior, increased locoregional recurrence, and decreased survival in many carcinomas. However, the significance of PNI in papillary thyroid cancer (PTC) is incompletely characterized., Methods: Patients diagnosed with PTC and PNI from 2010-2020 at a single, academic center were identified and matched using a 1:2 scheme to patients without PNI based on gross extrathyroidal extension (ETE), nodal metastasis, positive margins, and tumor size (±4 cm). Mixed and fixed effects models were used to analyze the association of PNI with extranodal extension (ENE)-a surrogate marker of poor prognosis., Results: In total, 78 patients were included (26 with PNI, 52 without PNI). Both groups had similar demographics and ultrasound characteristics preoperatively. Central compartment lymph node dissection was performed in most patients (71%, n = 55), and 31% (n = 24) underwent a lateral neck dissection. Patients with PNI had higher rates of lymphovascular invasion (50.0% vs. 25.0%, p = 0.027), microscopic ETE (80.8% vs. 44.0%, p = 0.002), and a larger burden [median 5 (interquartile range [IQR] 2-13) vs. 2 (1-5), p = 0.010] and size [median 1.2 cm (IQR 0.6-2.6) vs. 0.4 (0.2-1.4), p = 0.008] of nodal metastasis. Among patients with nodal metastasis, those with PNI had an almost fivefold increase in ENE [odds ratio [OR] 4.9 (95% confidence interval [CI] 1.5-16.5), p = 0.008] compared with those without PNI. More than a quarter (26%) of all patients had either persistent or recurrent disease over follow-up (IQR 16-54 months)., Conclusions: PNI is a rare, pathologic finding that is associated with ENE in a matched cohort. Additional investigation into PNI as a prognostic feature in PTC is warranted., (© 2023. Society of Surgical Oncology.)

A subset of thyroid cancers, recurrent differentiated thyroid cancers and anaplastic thyroid cancer (ATC), are difficult to treat by thyroidectomy and systemic therapy. A common mutation in thyroid cancer, BRAFV600E, has targetable treatment options; however, the results have been disappointing in thyroid cancers compared with BRAFV600E melanoma, as thyroid cancers quickly become resistant to BRAFV600E inhibitor (BRAFi). Here, we studied the molecular pathway that is induced in BRAFV600E thyroid cancer cells and patient-derived tumor samples in response to BRAFi, vemurafenib, using RNA-sequencing and molecular analysis. Both inducible response to BRAFi and acquired BRAFi resistance in BRAFV600E thyroid cancer cells showed significant activation of the JAK/STAT pathway. Functional analyses revealed that the combination of BRAFi and inhibitors of JAK/STAT pathway controlled BRAFV600E thyroid cancer cell growth. The Cancer Genome Atlas data analysis demonstrated that potent activation of the JAK/STAT signaling was associated with shorter recurrence rate in patients with differentiated thyroid cancer. Analysis of tumor RNA expression in patients with poorly differentiated thyroid cancer and ATC also support that enhanced activity of JAK/STAT signaling pathway is correlated with worse prognosis. Our study demonstrates that JAK/STAT pathway is activated as BRAFV600E thyroid cancer cells develop resistance to BRAFi and that this pathway is a potential target for anticancer activity and to overcome drug resistance that commonly develops to treatment with BRAFi in thyroid cancer., Implications: Dual inhibition of BRAF and JAK/STAT signaling pathway is a potential therapeutic treatment for anticancer activity and to overcome drug resistance to BRAFi in thyroid cancer., (©2023 American Association for Cancer Research.)

Introduction: Roux-en-Y gastric bypass (RYGB) has been the preferred operation for obese patients with gastroesophageal reflux disease (GERD); however, some patients are hesitant to undergo bypass. Obese patients have a multifactorial predisposition to GERD, including lower esophageal sphincter (LES) dysfunction and aberrant pressure gradients across their diaphragmatic crura. Among non-obese patients, anti-reflux surgery (ARS) with hiatal hernia (HH) repair and LES augmentation has shown excellent long-term results. We aimed to determine whether patient satisfaction and GERD recurrence differed between obese and non-obese patients who underwent ARS., Methods: Review of patients who underwent ARS between January 2012 and June 2021 was performed. Perioperative and postoperative characteristics were compared across three BMI groups: BMI < 30 kg/m 2 , 30 kg/m 2  ≤ BMI < 35 kg/m 2 , and BMI ≥ 35 kg/m 2 ., Results: Four-hundred thirteen patients were identified, of which 294 (71.1%) had BMI < 30 kg/m 2 , 87 (21.1%) were 30 kg/m 2  ≤ BMI < 35 kg/m 2 , and 32 (7.7%) had a BMI ≥ 35 kg/m 2 . Patients with BMI ≥ 35 kg/m 2 had higher preoperative manometric and EndoFLIP™ intra-balloon pressure at the LES than those with lower BMIs. This value was increased to a similar level throughout ARS across the three cohorts. Post-operative GERD-specific satisfaction was similar across the three cohorts, as were rates of postoperative reflux and hiatal hernia recurrence on barium swallow; rates of reoperation were low., Conclusions: ARS with HH repair and LES augmentation may be appropriate for select patients across a range of BMIs, including those with a BMI ≥ 35 kg/m 2 who are hesitant to undergo RYGB., (© 2022. The Society for Surgery of the Alimentary Tract.)

Background: Sleeve gastrectomy is among the most commonly-performed procedures for morbid obesity. However, patients occasionally develop post-sleeve gastroesophageal reflux disease (GERD). Identifying patients most at risk for this complication remains difficult. We aimed to correlate intra-operative physiologic measurements of the lower esophageal sphincter (LES) at the gastroesophageal junction (GEJ) during robotic sleeve gastrectomy in an attempt to identify predictors of post-sleeve GERD symptoms., Methods: A retrospective chart review of a prospectively maintained database identified 28 patients in whom robotic sleeve gastrectomy was performed utilizing EndoFLIP™ technology between January and September 2021. Intraoperative LES measurements at the GEJ including cross-sectional area (CSA), distensibility index (DI), intra-balloon pressure, and high-pressure zone (HPZ length) were correlated with post-operative GERD., Results: GEJ CSA, pressure, and DI increased over the course of the surgery (CSA pre-op: 31 (IQR 19.3-39.5) mm 2 vs. post-op: 67 (IQR 40.8-95.8) mm 2 , p < 0.001; pressure: 25.8 (IQR 20.2-33.1) mmHg vs. 31.5 (IQR 28.9-37.0) mmHg, p = 0.007; DI 1.1 (IQR 0.8-1.8) mm 2 /mmHg vs. 2.0 (IQR 1.2-3.0) mm 2 /mmHg, p =  < 0.001), whereas HPZ length decreased (2.5 (IQR 2.5-3) cm vs. 2.0 (IQR 1.3-2.5) cm, p = 0.022). Twenty-three patients (82.1%) completed a post-operative GERD questionnaire. Fifteen (65.2%) had no GERD symptoms before or after surgery; 5 (21.7%) reported new post-sleeve GERD symptoms; 3 (13.0%) reported exacerbation of pre-existing GERD symptoms. Patients with new or worsening GERD symptoms had higher post-sleeve DIs (3.2 (IQR 1.9-4.5) mm 2 /mmHg vs. 1.5 (IQR 1.2-2.4) mm 2 /mmHg, p = 0.024) and lower post-sleeve LES pressures (29.9 (IQR 26.3-32.9) mmHg vs. 35.2 (IQR 31.0-38.0) mmHg, p = 0.023) than those without., Conclusions: An increase in GEJ CSA, pressure, and DI, and a decrease in GEJ length can be expected during robotic sleeve gastrectomy. Patients with new or worsening post-sleeve GERD symptoms have higher post-sleeve DI and lower post-sleeve LES pressure than their asymptomatic counterparts., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Pediatric papillary thyroid carcinomas (PTCs) are more invasive than adult PTCs. No large, contemporary cohort study has been conducted to determine whether younger children are at higher risk for advanced disease at presentation compared to adolescents. We aimed to describe pediatric PTC and contextualize its characteristics with a young adult comparison cohort. Methods: The National Cancer Database was interrogated for pediatric and young adult PTCs diagnosed between 2004 and 2017. Clinical variables were compared between prepubertal (≤10 years old), adolescent (11-18 years old), and young adult (19-39 years old) groups. Multivariable logistic regression modeling for independent predictors of metastases was conducted. A subanalysis of microcarcinomas (size ≤10 mm) was performed. Results: A total of 4860 pediatric (prepubertal n  = 274, adolescents n  = 4586) and 101,159 young adult patients were included. Prepubertal patients presented with more extensive burden of disease, including significantly larger primary tumors, higher prevalence of nodal and distant metastases, and increased frequency of features such as lymphovascular invasion, and extrathyroidal extension (ETE). Prepubertal age was an independent predictor of positive regional nodes (adjusted odds ratio [AOR] = 1.36 [95% confidence interval {CI} 1.01-1.84], p  = 0.04) and distant metastatic disease (AOR = 3.12 [CI 1.96-4.96], p  < 0.001). However, there was no difference in survival between groups ( p  = 0.32). Prepubertal age independently predicted lymph node metastases for microcarcinomas (AOR = 2.19 [CI 1.10-4.36], p  = 0.03). Prepubertal ( n  = 41) versus adolescent ( n  = 937) patient age was associated with gross ETE ( p  = 0.004), even with primary tumors ≤1 cm in size. Conclusions: Patients aged <11 years old present with more advanced disease than adolescents, with a higher likelihood of nodal and distant metastatic disease at time of diagnosis, although survival is high. Prepubertal children undergo more extensive treatment, likely reflective of more invasive disease at the outset, even in the setting of a subcentimeter primary tumor.

Background: Anaplastic thyroid carcinoma (ATC) is a rare and lethal form of thyroid cancer. Overall prognosis is unclear when it arises focally in a background of papillary thyroid cancer (PTC). Clinicopathologic features and outcomes of tumors with coexisting PTC and ATC histologies (co-PTC/ATC) were categorized., Methods: The National Cancer Database was queried for histologic codes denoting PTC, ATC, and co-PTC/ATC, defined as Grade 4 PTC, diagnosed from 2004 to 2017. Clinicopathologic features, OS, and treatment outcomes were analyzed by histologic type., Results: A total of 386,862 PTC, 763 co-PTC/ATC, and 3,880 ATC patients were identified. Patients with co-PTC/ATC had clinicopathologic features in-between those of PTC and ATC, including rates of tumor size >4 cm, extrathyroidal extension, and distant metastases. On multivariable Cox proportional hazards modeling, age >55 years, Charlson-Deyo score ≥2, positive lymph nodes, lymphovascular invasion, distant metastases, and positive surgical margins were associated with worse OS, whereas radioactive iodine (RAI) and external beam radiation therapy (EBRT) were associated with improved OS, irrespective of margin status. OS was worse for co-PTC/ATC than for PTC but better than for ATC and differed based on the presence or absence of "aggressive" tumor features, including lymph node positivity, lymphovascular invasion, distant metastases, and positive surgical margins., Conclusions: Survival of patients with co-PTC/ATC is dependent on the presence of aggressive clinicopathologic features and lies within a spectrum between that of PTC and ATC. Adjuvant RAI and EBRT treatment may be beneficial, even after R0 resection., (© 2022. Society of Surgical Oncology.)

Pancreatic neuroendocrine tumors (PNETs) are malignancies arising from the islets of Langerhans. Therapeutic options are limited for the over 50% of patients who present with metastatic disease. We aimed to identify mechanisms to remodel the PNET tumor microenvironment (TME) to ultimately enhance susceptibility to immunotherapy. The TMEs of localized and metastatic PNETs were investigated using an approach that combines RNA-Seq, cancer and T cell profiling, and pharmacologic perturbations. RNA-Seq analysis indicated that the primary tumors of metastatic PNETs showed significant activation of inflammatory and immune-related pathways. We determined that metastatic PNETs featured increased numbers of tumor-infiltrating T cells compared with localized tumors. T cells isolated from both localized and metastatic PNETs showed evidence of recruitment and antigen-dependent activation, suggestive of an immune-permissive microenvironment. A computational analysis suggested that vorinostat, a histone deacetylase inhibitor, may perturb the transcriptomic signature of metastatic PNETs. Treatment of PNET cell lines with vorinostat increased chemokine CCR5 expression by NF-κB activation. Vorinostat treatment of patient-derived metastatic PNET tissues augmented recruitment of autologous T cells, and this augmentation was substantiated in a mouse model of PNET. Pharmacologic induction of chemokine expression may represent a promising approach for enhancing the immunogenicity of metastatic PNET TMEs.

Background: Among surgical patients, care fragmentation (CF) is associated with worse outcomes. However, oncologic literature documents an association between high surgical volume and improved outcomes, favoring centralized cancer-surgery centers and thus predisposing to CF in patients with surgically treated tumors. We aimed to identify features associated with CF and ascertain differences in overall survival (OS) among patients with differentiated thyroid cancer (DTC)., Methods: The National Cancer Database was queried for DTC patients diagnosed from 2009 to 2017. Patients experienced CF if part of their treatment was performed outside of the reporting facility or an associated office. A multivariable logistic regression analysis identified independent features associated with CF. A Cox multivariable regression analysis assessed the impact of CF on OS. A Kaplan-Meier analysis compared survival differences between patients experiencing CF or unified care (UC)., Results: A total of 131,620 patients were included. Among them, 70,204 (53.3%) experienced CF and 61,416 (46.7%) experienced UC. Age < 55, residing in high-income areas, and stage 3 and 4 tumors were features independently associated with CF, whereas uninsured patients were less likely to experience CF than the privately insured. The features most strongly associated with CF were treatment at highest thyroid cancer-surgery volume institutions and traveling in the top distance quartile. While patients with CF experienced minor delays in time from diagnosis to surgery, 5-year OS was improved among patients with CF compared to UC for those with Stage 1-3 disease., Conclusions: Among patients with DTC, CF is associated with treatment at a highest thyroid cancer surgery volume facility and improved OS in a setting of minor treatment delays., (© 2022. The Author(s) under exclusive licence to Société Internationale de Chirurgie.)

Introduction: Sex-based differences in survival have emerged among patients with pancreatic neuroendocrine tumors (PNETs). Mechanisms driving these differences remain poorly understood. We aimed to further characterize sex-based clinicopathologic and survival differences among patients with PNETs and correlate divergent mutational signatures in these patients., Methods: The National Cancer Database (NCDB) was queried for PNET patients diagnosed 2004-2017 who underwent surgery. Clinicopathologic features were analyzed by sex. The overall survival (OS) of men and women by disease stage was compared using the Kaplan-Meier method. Differences in PNET mutational signatures were analyzed by querying the American Association for Cancer Research Genomics Evidence Neoplasia Information (AACR-GENIE) Cohort v11.0-public. Frequencies of mutational signatures were compared by Fischer's exact (FE) test, adjusting for multiple testing via the Benjamini-Hochberg correction., Results: About 15,202 patients met inclusion criteria from the NCDB; 51.9% were men and 48.1% were women. Men more frequently had tumors > 2 cm than women and more commonly had poorly or undifferentiated tumors. Despite this, lymph node positivity and distant metastases were similar. Differences in OS were only seen among those with early stage rather than stage 3 or 4 disease. MEN1 and DAXX mutations were more frequent among men with PNETs, whereas TP53 mutations were more frequent among women when assessed by FE test. However, neither of these mutational differences maintained statistical significance when adjusted for multiple testing., Conclusion: Compared to women, men have larger tumors but similar rates of distant metastases at time of surgery. OS differences appear to be driven by patients with early-stage disease without clearly identifiable differences in mutational signatures between the sexes., (© 2022. The Society for Surgery of the Alimentary Tract.)

Introduction: Alterations in the microbiome contribute to the pathogenesis of many gastrointestinal diseases. However, the composition of the microbiome in gallbladder disease is not well described., Methods: We aimed to characterize the biliary microbiome in cholecystectomy patients. Bile and biliary stones were collected at cholecystectomy for a variety of surgical indications between 2017 and 2019. DNA was extracted and metagenomic sequencing was performed with subsequent taxonomic classification using Kraken2. The fraction of bacterial to total DNA reads, relative abundance of bacterial species, and overall species diversity were compared between pathologies and demographics., Results: A total of 74 samples were obtained from 49 patients: 46 bile and 28 stones, with matched pairs from 25 patients. The mean age was 48 years, 76% were female, 29% were Hispanic, and 29% of patients had acute cholecystitis. The most abundant species were Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pasteurianus. The bacterial fraction in bile and stone samples was higher in acute cholecystitis compared to other non-infectious pathologies (p < 0.05). Neither the diversity nor differential prevalence of specific bacterial species varied significantly between infectious and other non-infectious gallbladder pathologies. Multivariate analysis of the non-infectious group revealed that patients over 40 years of age had increased bacterial fractions (p < 0.05)., Conclusions: Metagenomic sequencing permits characterization of the gallbladder microbiome in cholecystectomy patients. Although a higher prevalence of bacteria was seen in acute cholecystitis, species and diversity were similar regardless of surgical indication. Additional study is required to determine how the microbiome can contribute to the development of symptomatic gallbladder disease., (© 2022. The Society for Surgery of the Alimentary Tract.)

Background: Hiatal hernia re-approximation during index anti-reflux surgery (ARS) contributes approximately 80% of overall change in distensibility index (DI) and, potentially, compliance of the gastroesophageal (GEJ), while sphincter augmentation contributes approximately 20%. Whether this is seen in re-operative ARS is unclear. We quantify the physiologic parameters of the GEJ at each step of robotic re-operative ARS and compare these to index ARS., Methods: Robotic ARS with hiatal hernia repair was performed on 195 consecutive patients with pathologic reflux utilizing EndoFLIP™, of which 26 previously had ARS. Intra-operative GEJ measurements, including cross-sectional area (CSA), pressure, DI, and high-pressure zone (HPZ) length were collected pre-repair, post-diaphragmatic re-approximation, post-mesh placement, and post-lower-esophageal sphincter (LES) augmentation., Results: Both cohorts were similar by sex and BMI and underwent similar procedures. The re-operative cohort was older (60.6 ± 15.3 vs. 52.7 ± 16.2 years, p = 0.03), had more frequent pre-operative dysphagia (69.2% vs. 42.6%, p = 0.01) and esophageal dysmotility on barium swallow (75.0% vs. 35.0%, p < 0.001) but lower rates of hiatal hernia on endoscopy (30.8% vs. 68.7%, p < 0.001) compared to index procedures. Among the re-operative cohort, the CSA decreased by 34 (IQR - 80, - 15) mm 2 and DI 1.1 (IQR - 2.4, - 0.6) mm 2 /mmHg (both p < 0.001). Pressure increased by 11.2 (IQR 4.7, 14.9) mmHg and HPZ by 1.5 (1,2) cm (both p < 0.001). These changes were similar to those seen in index ARS. Diaphragmatic re-approximation contributed to a greater percentage of overall change to the GEJ than did the augmentation procedure, with 72% of the change in DI occurring during hiatal closure, similar to that seen during index ARS., Conclusions: During re-operative ARS, dynamic intra-operative monitoring can quantify the effects of each operative step on GEJ physiologic parameters. Diaphragmatic re-approximation appears to have a greater effect on GEJ physiology than does LES-sphincter augmentation during both index and re-operative ARS., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Anti-reflux surgery (ARS) has known long-term complications, including dysphagia, bloat, and flatulence, among others. The factors affecting the development of post-operative dysphagia are poorly understood. We investigated the correlation of intra-operative esophagogastric junction (EGJ) characteristics and procedure type with post-operative dysphagia following ARS., Methods: Robotic ARS was performed on 197 consecutive patients with pathologic reflux utilizing EndoFLIP™ technology. Intraoperative EGJ measurements including distensibility index (DI), cross-sectional area (CSA), and high-pressure zone (HPZ) length were collected. Dysphagia was assessed pre-operatively and at 3 months post-operatively., Results: The median pre-operative DI for all procedures was 2.6 (IQR 1.6-4.5) mm 2 /mmHg. There was no difference in post-operative DI between procedures [Hill: 0.9 (IQR 0.7-1.1) mm 2 /mmHg, Nissen: 1.0 (IQR 0.7-1.4) mm 2 /mmHg, Toupet: 1.2 (IQR 0.8-1.5) mm 2 /mmHg, Linx: 1.0 (IQR 0.7-1.2) mm 2 /mmHg, p = 0.24], whereas post-operative HPZ length differed by augmentation type [Hill: 3 (IQR 2.8-3) cm, Nissen: 3.5 (IQR 3-3.5) cm, Toupet: 3 (IQR 2.5-3.5) cm, Linx: 2.5 (IQR 2.5-3) cm, p = 0.032]. Eighty-nine patients (45.2%) had pre-operative dysphagia. Thirty-two patients (27.6%) reported any dysphagia at their 3-month post-operative visit and 12 (10.3%) developed new or worsening post-operative dysphagia [Hill: 2/18 (11.1%), Nissen: 2/35 (5.7%), Toupet: 4/54 (7.4%), Linx: 4/9 (44.4%), p = 0.006]. The median pre-operative and post-operative DI of patients who developed new or worsening dysphagia was 2.0 (IQR 0.9-3.8) mm 2 /mmHg and 1.2 (IQR 1.0-1.8) mm 2 /mmHg, respectively, and that of those who did not was 2.5 (IQR 1.6-4.0) mm 2 /mmHg and 1.0 (IQR 0.7-1.4) mm 2 /mmHg (p = 0.21 and 0.16, respectively)., Conclusions: Post-operative DI was similar between procedures, and there was no correlation with new or worsening post-operative dysphagia. Linx placement was associated with higher rates of new or worsening post-operative dysphagia despite a shorter post-procedure HPZ length and similar post-operative DI when compared to other methods of LES augmentation., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Competing Interests: SSL has consulted for AbbVie, Gilead Sciences, Justice Canada (HCV file). All other authors declared no competing interests. We express gratitude to the communities across Alberta who have collaborated in the ECHO programme, as well as the advisory committee in shaping and supporting this collaborative approach. We acknowledge the ECHO programme is located on Treaty 6, 7, and 8, and on Métis Nation of Alberta Region 3 lands. KPRD, KPW, AL, and HC are Indigenous peoples. Total HCV treatment data for Alberta were kindly provided by IQVIA (Kirkland, QC, Canada).

Background: Indigenous populations experience higher rates of hepatitis C virus (HCV) infections in Canada. The Extension for Community Health Outcomes+ (ECHO+) telehealth model was implemented in Alberta to support HCV screening and treatment, using Zoom technology to support Indigenous patient access to specialist care closer to home. Our goal was to expand this program to more Indigenous communities in Alberta, using various Indigenous-led or co-designed methods., Methods: The ECHO+ team implemented a Two-Eyed Seeing framework, incorporating Indigenous wholistic approaches alongside Western treatment. This approach works with principles of respect, reciprocity, and relationality. The ECHO+ team identified Indigenous-specific challenges, including access to liver specialist care, HCV awareness, stigma, barriers to screening and lack of culturally relevant approaches., Results: Access to HCV care via this program significantly increased HCV antiviral use in the past 5 years. Key lessons learned include Indigenous-led relationship building and development of project outputs in response to community needs influences impact and increases relevant changes increasing access to HCV care. Implementation of ECHO+ was carried out through biweekly telehealth sessions, problem solving in partnership with Indigenous communities, increased HCV awareness, and flexibility resulting from the impacts of COVID-19., Conclusion: Improving Indigenous patient lives and reducing inequity requires supporting local primary health care providers to create and sustain integrated HCV prevention, diagnosis, treatment, and support services within a culturally safe and reciprocal model. ECHO+ uses telehealth and culturally appropriate methodology and interventions alongside multiple stakeholder collaborations to improve health outcomes for HCV., Competing Interests: SS Lee received consulting or advisory board fees from AbbVie, Gilead, Intercept, Janssen, and Merck, and speaker honoraria from AbbVie, Gilead, London Drugs, Lupin, Merck, and Pendopharm. The other authors have nothing to disclose., (Copyright © 2022 Canadian Association for the Study of the Liver.)

Background: Disparities exist in access to high-volume surgeons, who have better outcomes after thyroidectomy. The association of the Affordable Care Act's Medicaid expansion with access to high-volume thyroid cancer surgery centers remains unclear., Methods: The National Cancer Database was queried for all adult thyroid cancer patients diagnosed from 2010 to 2016. Hospital quartiles (Q1-4) defined by operative volume were generated. Clinicodemographics and adjusted odds ratios for treatment per quartile were analyzed by insurance status. An adjusted difference-in-differences analysis examined the association between implementation of the Affordable Care Act and changes in payer mix by hospital quartile., Results: In total, 241,448 patients were included. Medicaid patients were most commonly treated at Q3-Q4 hospitals (Q3 odds ratios 1.05, P = .020, Q4 1.11, P < .001), whereas uninsured patients were most often treated at Q2-Q4 hospitals (Q2 odds ratios 2.82, Q3 2.34, Q4 2.07, P < .001). After expansion, Medicaid patients had lower odds of surgery at Q3-Q4 compared with Q1 hospitals (odds ratios Q3 0.82, P < .001 Q4 0.85, P = .002) in expansion states, but higher odds of treatment at Q3-Q4 hospitals in nonexpansion states (odds ratios Q3 2.23, Q4 1.86, P < .001). Affordable Care Act implementation was associated with increased proportions of Medicaid patients within each quartile in expansion compared with nonexpansion states (Q1 adjusted difference-in-differences 5.36%, Q2 5.29%, Q3 3.68%, Q4 3.26%, P < .001), and a decrease in uninsured patients treated at Q4 hospitals (adjusted difference-in-differences -1.06%, P = .001)., Conclusions: Medicaid expansion was associated with an increased proportion of Medicaid patients undergoing thyroidectomy for thyroid cancer in all quartiles, with increased Medicaid access to high-volume centers in expansion compared with nonexpansion states., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: We aimed to characterize the association between differentiated thyroid cancer (DTC) patient insurance status and appropriateness of therapy (AOT) regarding extent of thyroidectomy and radioactive iodine (RAI) treatment., Methods: The National Cancer Database was queried for DTC patients diagnosed between 2010 and 2016. Adjusted odds ratios (AOR) for AOT, as defined by the American Thyroid Association guidelines, and hazard ratios (HR) for overall survival (OS) were calculated. A difference-in-differences (DD) analysis examined the association of Medicaid expansion with outcomes for low-income patients aged <65., Results: A total of 224,500 patients were included. Medicaid and uninsured patients were at increased risk of undergoing inappropriate therapy, including inappropriate lobectomy (Medicaid 1.36, 95% confidence interval [CI]: 1.21-1.54; uninsured 1.30, 95% CI: 1.05-1.60), and under-treatment with RAI (Medicaid 1.20, 95% CI: 1.14-1.26; uninsured 1.44, 95% CI: 1.33-1.55). Inappropriate lobectomy (HR 2.0, 95% CI: 1.7-2.3, P < .001) and under-treatment with RAI (HR 2.3, 95% CI: 2.2-2.5, P < .001) were independently associated with decreased survival, while appropriate surgical resection (HR 0.3, 95% CI: 0.3-0.3, P < .001) was associated with improved odds of survival; the model controlled for all relevant clinico-pathologic variables. No difference in AOT was observed in Medicaid expansion versus non-expansion states with respect to surgery or adjuvant RAI therapy., Conclusion: Medicaid and uninsured patients are at significantly increased odds of receiving inappropriate treatment for DTC; both groups are at a survival disadvantage compared with Medicare and those privately insured., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Anaplastic thyroid cancer (ATC) is a rare cancer with poor prognosis and few treatment options. The objective of this study was to investigate new immune-associated therapeutic targets by identifying ATC-derived, human leukocyte antigen (HLA) class II-presenting peptides. One protein that generated multiple peptides in ATC was chondroitin sulfate-proteoglycan-4 (CSPG4), a transmembrane proteoglycan with increased expression in multiple aggressive cancers, but not yet investigated in ATC. Methods: We applied autologous peripheral blood T cells to ATC patient-derived xenografted mice to examine whether ATC induces a tumor-specific T cell response. We then identified peptide antigens eluted from the HLA-DQ complex in ATC patient-derived cells using mass spectrometry, detecting abundant CSPG4-derived peptides specific to the ATC sample. Next, we analyzed the surface expression level of CSPG4 in thyroid cancer cell lines and primary cell culture using flow cytometry. In addition, we used immunohistochemistry to compare the expression level and localization of the CSPG4 protein in ATC, papillary thyroid cancer, and normal thyroid tissue. We then investigated the correlation between CSPG4 expression and clinicopathological features of patients with thyroid cancer. Results: We found that ATC tissue had a high level of HLA-DQ expression and that the patient's CD4 + T cells showed activation when exposed to ATC. By eluting the HLA-DQ complex of ATC tissue, we found that CSPG4 generated one of the most abundant and specific peptides. CSPG4 expression at the cell surface of thyroid cancer was also significantly high when determined by flow cytometry, with the majority of ATC cell lines exhibiting ∼10-fold higher mean fluorescence intensity. Furthermore, most ATC patient cases expressed CSPG4 in the cytoplasm or membrane of the tumor cells. CSPG4 expression was correlated with tumor size, extrathyroidal extension, and intercellular adhesion molecule-1 (ICAM-1) circumferential expression. CSPG4 mRNA overexpression was associated with worse overall survival in patients with ATC and poorly differentiated thyroid cancer. Conclusions: CSPG4 expression is significantly elevated in aggressive thyroid cancers, with a strong correlation with a poor prognosis. The vast number of HLA-DQ eluted CSPG4 peptides was identified in ATC, demonstrating the potential of CSPG4 as a novel immunotherapeutic target for ATC.

Necrotizing enterocolitis (NEC) is the most devastating gastrointestinal disease of the premature infant. We have recently shown that NEC development occurs after an increase in proinflammatory CD4Th17 (Th17) cells and reduced anti-inflammatory forkhead box P3 regulatory T cells (Tregs) to the premature small intestine of mice and humans, which can be experimentally reversed in mice by administration of all-trans retinoic acid (ATRA). We have also shown that NEC is characterized by apoptosis of Lgr5-positive intestinal stem cells (ISCs-Lgr5 cells) within the crypts of Lieberkühn, which are subsequently essential for intestinal homeostasis. We now hypothesize that the normal lymphocyte balance within the lamina propria of the intestine can be achieved via administration of ATRA which restores mucosal integrity by preventing the loss of ISCs. Using both in vivo and in vitro strategies, we now demonstrate that Th17 recruitment and Treg depletion lead to increased apoptosis within ISC niches, significantly impairing proliferative capacity and mucosal healing. ATRA exerted its protective effects by preventing T cell imbalance, ultimately leading to the protection of the ISC pool preventing the development of NEC in mice. These findings raise the exciting possibility that dietary manipulations could prevent and treat NEC by modulating lymphocyte balance and the ISC pool within the newborn small intestine.

Peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC1α) is the primary regulator of mitochondrial biogenesis and was recently found to be highly expressed within the intestinal epithelium. PGC1α is decreased in the intestinal epithelium of patients with inflammatory bowel disease, but its role in pathogenesis is uncertain. We now hypothesize that PGC1α protects against the development of colitis and helps to maintain the integrity of the intestinal barrier. We selectively deleted PGC1α from the intestinal epithelium of mice by breeding a PGC1α(loxP/loxP) mouse with a villin-cre mouse. Their progeny (PGC1α(ΔIEC) mice) were subjected to 2% dextran sodium sulfate (DSS) colitis for 7 days. The SIRT1 agonist SRT1720 was used to enhance PGC1α activation in wild-type mice during DSS exposure. Mice lacking PGC1α within the intestinal epithelium were more susceptible to DSS colitis than their wild-type littermates. Pharmacologic activation of PGC1α successfully ameliorated disease and restored mitochondrial integrity. These findings suggest that a depletion of PGC1α in the intestinal epithelium contributes to inflammatory changes through a failure of mitochondrial structure and function as well as a breakdown of the intestinal barrier, which leads to increased bacterial translocation. PGC1α induction helps to maintain mitochondrial integrity, enhance intestinal barrier function, and decrease inflammation., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

The nature and role of the intestinal leukocytes in necrotizing enterocolitis (NEC), a severe disease affecting premature infants, remain unknown. We now show that the intestine in mouse and human NEC is rich in lymphocytes that are required for NEC development, as recombination activating gene 1–deficient (Rag1–/–) mice were protected from NEC and transfer of intestinal lymphocytes from NEC mice into naive mice induced intestinal inflammation. The intestinal expression of the lipopolysaccharide receptor TLR4, which is higher in the premature compared with full-term human and mouse intestine, is required for lymphocyte influx through TLR4-mediated upregulation of CCR9/CCL25 signaling. TLR4 also mediates a STAT3-dependent polarization toward increased proinflammatory CD3+CD4+IL-17+ and reduced tolerogenic Foxp3+ Treg lymphocytes (Tregs). Th17 lymphocytes were required for NEC development, as inhibition of STAT3 or IL-17 receptor signaling attenuated NEC in mice, while IL-17 release impaired enterocyte tight junctions, increased enterocyte apoptosis, and reduced enterocyte proliferation, leading to NEC. Importantly, TLR4-dependent Th17 polarization could be reversed by the enteral administration of retinoic acid, which induced Tregs and decreased NEC severity. These findings identify an important role for proinflammatory lymphocytes in NEC development via intestinal epithelial TLR4 that could be reversed through dietary modification.

Breast milk is the most effective strategy to protect infants against necrotizing enterocolitis (NEC), a devastating disease that is characterized by severe intestinal necrosis. Previous studies have demonstrated that the lipopolysaccharide receptor Toll-like receptor 4 (TLR4) plays a critical role in NEC development via deleterious effects on mucosal injury and repair. We now hypothesize that breast milk protects against NEC by inhibiting TLR4 within the intestinal epithelium, and sought to determine the mechanisms involved. Breast milk protected against NEC and reduced TLR4 signaling in wild-type neonatal mice, but not in mice lacking the epidermal growth factor receptor (EGFR), whereas selective removal of EGF from breast milk reduced its protective properties, indicating that breast milk inhibits NEC and attenuates TLR4 signaling via EGF/EGFR activation. Overexpression of TLR4 in the intestinal epithelium reversed the protective effects of breast milk. The protective effects of breast milk occurred via inhibition of enterocyte apoptosis and restoration of enterocyte proliferation. Importantly, in IEC-6 enterocytes, breast milk inhibited TLR4 signaling via inhibition of glycogen synthase kinase-3β (GSK3β). Taken together, these findings offer mechanistic insights into the protective role for breast milk in NEC, and support a link between growth factor and innate immune receptors in NEC pathogenesis.

The cellular cues that regulate the apoptosis of intestinal stem cells (ISCs) remain incompletely understood, yet may play a role in diseases characterized by ISC loss including necrotizing enterocolitis (NEC). Toll-like receptor-4 (TLR4) was recently found to be expressed on ISCs, where its activation leads to ISC apoptosis through mechanisms that remain incompletely explained. We now hypothesize that TLR4 induces endoplasmic reticulum (ER) stress within ISCs, leading to their apoptosis in NEC pathogenesis, and that high ER stress within the premature intestine predisposes to NEC development. Using transgenic mice and cultured enteroids, we now demonstrate that TLR4 induces ER stress within Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5)-positive ISCs, resulting in crypt apoptosis. TLR4 signaling within crypts was required, because crypt ER stress and apoptosis occurred in TLR4(ΔIEC-OVER) mice expressing TLR4 only within intestinal crypts and epithelium, but not TLR4(ΔIEC) mice lacking intestinal TLR4. TLR4-mediated ER stress and apoptosis of ISCs required PERK (protein kinase-related PKR-like ER kinase), CHOP (C/EBP homologous protein), and MyD88 (myeloid differentiation primary response gene 88), but not ATF6 (activating transcription factor 6) or XBP1 (X-box-binding protein 1). Human and mouse NEC showed high crypt ER stress and apoptosis, whereas genetic inhibition of PERK or CHOP attenuated ER stress, crypt apoptosis, and NEC severity. Strikingly, using intragastric delivery into fetal mouse intestine, prevention of ER stress reduced TLR4-mediated ISC apoptosis and mucosal disruption. These findings identify a novel link between TLR4-induced ER stress and ISC apoptosis in NEC pathogenesis and suggest that increased ER stress within the premature bowel predisposes to NEC development.

Antimicrobial proteins influence intestinal microbial ecology and limit proliferation of pathogens, yet the regulation of their expression has only been partially elucidated. Here, we have identified a putative pathway involving epithelial cells and intestinal intraepithelial lymphocytes (iIELs) that leads to antimicrobial protein (AMP) production by Paneth cells. Mice lacking γδ iIELs (TCRδ(-/-)) express significantly reduced levels of the AMP angiogenin 4 (Ang4). These mice were also unable to up-regulate Ang4 production following oral challenge by Salmonella, leading to higher levels of mucosal invasion compared to their wild type counterparts during the first 2 hours post-challenge. The transfer of γδ iIELs from wild type (WT) mice to TCRδ(-/-) mice restored Ang4 production and Salmonella invasion levels were reduced to those obtained in WT mice. The ability to restore Ang4 production in TCRδ(-/-) mice was shown to be restricted to γδ iIELs expressing Vγ7-encoded TCRs. Using a novel intestinal crypt co-culture system we identified a putative pathway of Ang4 production initiated by exposure to Salmonella, intestinal commensals or microbial antigens that induced intestinal epithelial cells to produce cytokines including IL‑23 in a TLR-mediated manner. Exposure of TCR-Vγ7(+) γδ iIELs to IL-23 promoted IL‑22 production, which triggered Paneth cells to secrete Ang4. These findings identify a novel role for γδ iIELs in mucosal defence through sensing immediate epithelial cell cytokine responses and influencing AMP production. This in turn can contribute to the maintenance of intestinal microbial homeostasis and epithelial barrier function, and limit pathogen invasion.

Non-alcoholic fatty liver disease (NAFLD) is a common disease with a spectrum of presentations. The current study utilized a lithogenic diet model of NAFLD. The diet was fed to mice that are either resistant (AKR) or susceptible (BALB/c and C57BL/6) to hepatitis followed by molecular and flow cytometric analysis. Following this, a similar approach was taken in congenic mice with specific mutations in immunological genes. The initial study identified a significant and profound increase in multiple ligands for the chemokine receptor CCR2 and an increase in CD44 expression in susceptible C57BL/6 (B6) but not resistant AKR mice. Ccr2(-/-) mice were completely protected from hepatitis and Cd44(-/-) mice were partially protected. Despite protection from inflammation, both strains displayed similar histological steatosis scores and significant increases in serum liver enzymes. CD45(+)CD44(+) cells bound to hyaluronic acid (HA) in diet fed B6 mice but not Cd44(-/-) or Ccr2(-/-) mice. Ccr2(-/-) mice displayed a diminished HA binding phenotype most notably in monocytes, and CD8(+) T-cells. In conclusion, this study demonstrates that absence of CCR2 completely and CD44 partially reduces hepatic leukocyte recruitment. These data also provide evidence that there are multiple redundant CCR2 ligands produced during hepatic lipid accumulation and describes the induction of a strong HA binding phenotype in response to LD feeding in some subsets of leukocytes from susceptible strains.

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants characterized by severe intestinal necrosis and for which breast milk represents the most effective protective strategy. Previous studies have revealed a critical role for the lipopolysaccharide receptor toll-like receptor 4 (TLR4) in NEC development through its induction of mucosal injury, yet the reasons for which intestinal ischemia in NEC occurs in the first place remain unknown. We hypothesize that TLR4 signaling within the endothelium plays an essential role in NEC development by regulating perfusion to the small intestine via the vasodilatory molecule endothelial nitric oxide synthase (eNOS). Using a unique mouse system in which we selectively deleted TLR4 from the endothelium, we now show that endothelial TLR4 activation is required for NEC development and that endothelial TLR4 activation impairs intestinal perfusion without effects on other organs and reduces eNOS expression via activation of myeloid differentiation primary response gene 88. NEC severity was significantly increased in eNOS(-/-) mice and decreased upon administration of the phosphodiesterase inhibitor sildenafil, which augments eNOS function. Strikingly, compared with formula, human and mouse breast milk were enriched in sodium nitrate--a precursor for enteral generation of nitrite and nitric oxide--and repletion of formula with sodium nitrate/nitrite restored intestinal perfusion, reversed the deleterious effects of endothelial TLR4 signaling, and reduced NEC severity. These data identify that endothelial TLR4 critically regulates intestinal perfusion leading to NEC and reveal that the protective properties of breast milk involve enhanced intestinal microcirculatory integrity via augmentation of nitrate-nitrite-NO signaling.

Chemokines and their receptors play a critical role in orchestrating immunity to microbial pathogens, including the orally acquired Th1-inducing protozoan parasite Toxoplasma gondii. Chemokine receptor CXCR3 is associated with Th1 responses, and here we use bicistronic CXCR3-eGFP knock-in reporter mice to demonstrate upregulation of this chemokine receptor on CD4⁺ and CD8⁺ T lymphocytes during Toxoplasma infection. We show a critical role for CXCR3 in resistance to the parasite in the intestinal mucosa. Absence of the receptor in Cxcr3⁻/⁻ mice resulted in selective loss of ability to control T. gondii specifically in the lamina propria compartment. CD4⁺ T cells were impaired both in their recruitment to the intestinal lamina propria and in their ability to secrete IFN-γ upon stimulation. Local recruitment of CD11b⁺Ly6C/G⁺ inflammatory monocytes, recently reported to be major anti-Toxoplasma effectors in the intestine, was not impacted by loss of CXCR3. However, inflammatory monocyte activation status, as measured by dual production of TNF-α and IL-12, was severely impaired in Cxcr3⁻/⁻ mice. Strikingly, adoptive transfer of wild-type but not Ifnγ⁻/⁻ CD4⁺ T lymphocytes into Cxcr3⁻/⁻ animals prior to infection corrected the defect in inflammatory macrophage activation, simultaneously reversing the susceptibility phenotype of the knockout animals. Our results establish a central role for CXCR3 in coordinating innate and adaptive immunity, ensuring generation of Th1 effectors and their trafficking to the frontline of infection to program microbial killing by inflammatory monocytes.

Factors regulating the proliferation and apoptosis of intestinal stem cells (ISCs) remain incompletely understood. Because ISCs exist among microbial ligands, immune receptors such as toll-like receptor 4 (TLR4) could play a role. We now hypothesize that ISCs express TLR4 and that the activation of TLR4 directly on the intestinal stem cells regulates their ability to proliferate or to undergo apoptosis. Using flow cytometry and fluorescent in situ hybridization for the intestinal stem cell marker Lgr5, we demonstrate that TLR4 is expressed on the Lgr5-positive intestinal stem cells. TLR4 activation reduced proliferation and increased apoptosis in ISCs both in vivo and in ISC organoids, a finding not observed in mice lacking TLR4 in the Lgr5-positive ISCs, confirming the in vivo significance of this effect. To define molecular mechanisms involved, TLR4 inhibited ISC proliferation and increased apoptosis via the p53-up-regulated modulator of apoptosis (PUMA), as TLR4 did not affect crypt proliferation or apoptosis in organoids or mice lacking PUMA. In vivo effects of TLR4 on ISCs required TIR-domain-containing adapter-inducing interferon-β (TRIF) but were independent of myeloid-differentiation primary response-gene 88 (MYD88) and TNFα. Physiological relevance was suggested, as TLR4 activation in necrotizing enterocolitis led to reduced proliferation and increased apoptosis of the intestinal crypts in a manner that could be reversed by inhibition of PUMA, both globally or restricted to the intestinal epithelium. These findings illustrate that TLR4 is expressed on ISCs where it regulates their proliferation and apoptosis through activation of PUMA and that TLR4 regulation of ISCs contributes to the pathogenesis of necrotizing enterocolitis.

Toxoplasma gondii is an obligate intracellular protozoan pathogen that traffics to the central nervous system (CNS) following invasion of its host. In the CNS, T. gondii undergoes transformation from a rapidly dividing tachyzoite to a long-lived, slow-dividing bradyzoite contained within cysts. The role of extracellular adenosine in T. gondii pathogenesis has not been previously investigated. T. gondii uses host purines such as adenosine for its energy needs, as it is unable to make its own. Here, we show that CD73(-/-) mice, which lack the ability to generate extracellular adenosine, are protected from T. gondii chronic infection, with significantly fewer cysts and reduced susceptibility to reactivation of infection in the CNS independent of host effector function. Parasite dissemination to the brain was unimpaired in CD73(-/-) hosts, suggesting that the reduced cyst number is due to impaired parasite differentiation in the CNS. Confirming this, T. gondii tachyzoites formed fewer cysts following alkaline pH stress in astrocytes isolated from CD73(-/-) mice compared with wild type, and in fibroblasts treated with a CD73 inhibitor. Cyst formation was rescued in CD73(-/-) astrocytes supplemented with adenosine, but not with adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine. Furthermore, mice lacking adenosine receptors had no defect in cyst formation. Based on these findings, we conclude that CD73 expression promotes Toxoplasma bradyzoite differentiation and cyst formation by a mechanism dependent on the generation of adenosine, but independent of adenosine receptor signaling. Overall, these findings suggest that modulators of extracellular adenosine may be used to develop therapies aimed at defending against human toxoplasmosis.

IL-12-mediated type 1 inflammation confers host protection against the parasitic protozoan Toxoplasma gondii. However, production of IFN-γ, another type 1 inflammatory cytokine, also drives lethality from excessive injury to the intestinal epithelium. As mechanisms that restore epithelial barrier function following infection remain poorly understood, this study investigated the role of trefoil factor 2 (TFF2), a well-established regulator of mucosal tissue repair. Paradoxically, TFF2 antagonized IL-12 release from dendritic cells (DCs) and macrophages, which protected TFF2-deficient (TFF2(-/-)) mice from T. gondii pathogenesis. Dysregulated intestinal homeostasis in naive TFF2(-/-) mice correlated with increased IL-12/23p40 levels and enhanced T cell recruitment at baseline. Infected TFF2(-/-) mice displayed low rates of parasite replication and reduced gut immunopathology, whereas wild-type (WT) mice experienced disseminated infection and lethal ileitis. p38 MAPK activation and IL-12p70 production was more robust from TFF2(-/-)CD8+ DC compared with WT CD8+ DC and treatment of WT DC with rTFF2 suppressed TLR-induced IL-12/23p40 production. Neutralization of IFN-γ and IL-12 in TFF2(-/-) animals abrogated resistance shown by enhanced parasite replication and infection-induced morbidity. Hence, TFF2 regulated intestinal barrier function and type 1 cytokine release from myeloid phagocytes, which dictated the outcome of oral T. gondii infection in mice.

Oral infection of certain inbred mouse strains with the protozoan Toxoplasma gondii triggers inflammatory pathology resembling lesions seen during human inflammatory bowel disease, in particular Crohn's disease (CD). Damage triggered by the parasite is largely localized to the distal portion of the small intestine, and as such is one of only a few models for ileal inflammation. This is important because ileal involvement is a characteristic of CD in over two-thirds of patients. The disease induced by Toxoplasma is mediated by Th1 cells and the cytokines tumor necrosis factor-α and interferon-γ. Inflammation is dependent upon IL-23, also identified by genome-wide association studies as a risk factor in CD. Development of lesions is concomitant with emergence of E. coli that display enhanced adhesion to the intestinal epithelium and subepithelial translocation. Furthermore, depletion of gut flora renders mice resistant to Toxoplasma-triggered ileitis. Recent findings suggest complex CCR2-dependent interactions between lamina propria T cells and intraepithelial lymphocytes in fueling proinflammatory pathology in the intestine. The advantage of the Toxoplasma model is that disease develops rapidly (within 7-10 days of infection) and can be induced in immunodeficient mice by adoptive transfer of mucosal T cells from infected donors. We propose that Toxoplasma acts as a trigger setting into motion a series of events culminating in loss of tolerance in the intestine and emergence of pathogenic T cell effectors. The Toxoplasma trigger model is providing new leaps in our understanding of immunity in the intestine.

The fetal intestinal mucosa is characterized by elevated Toll-like receptor 4 (TLR4) expression, which can lead to the development of necrotizing enterocolitis (NEC)--a devastating inflammatory disease of the premature intestine--upon exposure to microbes. To define endogenous strategies that could reduce TLR4 signaling, we hypothesized that amniotic fluid can inhibit TLR4 signaling within the fetal intestine and attenuate experimental NEC, and we sought to determine the mechanisms involved. We show here that microinjection of amniotic fluid into the fetal (embryonic day 18.5) gastrointestinal tract reduced LPS-mediated signaling within the fetal intestinal mucosa. Amniotic fluid is abundant in EGF, which we show is required for its inhibitory effects on TLR4 signaling via peroxisome proliferator-activated receptor, because inhibition of EGF receptor (EGFR) with cetuximab or EGF-depleted amniotic fluid blocked the inhibitory effects of amniotic fluid on TLR4, whereas amniotic fluid did not prevent TLR4 signaling in EGFR- or peroxisome proliferator-activated receptor γ-deficient enterocytes or in mice deficient in intestinal epithelial EGFR, and purified EGF attenuated the exaggerated intestinal mucosal TLR4 signaling in wild-type mice. Moreover, amniotic fluid-mediated TLR4 inhibition reduced the severity of NEC in mice through EGFR activation. Strikingly, NEC development in both mice and humans was associated with reduced EGFR expression that was restored upon the administration of amniotic fluid in mice or recovery from NEC in humans, suggesting that a lack of amniotic fluid-mediated EGFR signaling could predispose to NEC. These findings may explain the unique susceptibility of premature infants to the development of NEC and offer therapeutic approaches to this devastating disease.

Background and Aims: Understanding the interplay between genetic susceptibility, the microbiome, the environment and the immune system in Crohn's Disease (CD) is essential for developing optimal therapeutic strategies. We sought to examine the dynamics of the relationship between inflammation, the ileal microbiome, and host genetics in murine models of ileitis., Methods: We induced ileal inflammation of graded severity in C57BL6 mice by gavage with Toxoplasma gondii, Giardia muris, low dose indomethacin (LDI; 0.1 mg/mouse), or high dose indomethacin (HDI; 1 mg/mouse). The composition and spatial distribution of the mucosal microbiome was evaluated by 16S rDNA pyrosequencing and fluorescence in situ hybridization. Mucosal E. coli were enumerated by quantitative PCR, and characterized by phylogroup, genotype and pathotype., Results: Moderate to severe ileitis induced by T. gondii (day 8) and HDI caused a consistent shift from >95% gram + Firmicutes to >95% gram - Proteobacteria. This was accompanied by reduced microbial diversity and mucosal invasion by adherent and invasive E. coli, mirroring the dysbiosis of ileal CD. In contrast, dysbiosis and bacterial invasion did not develop in mice with mild ileitis induced by Giardia muris. Superimposition of genetic susceptibility and T. Gondii infection revealed greatest dysbiosis and bacterial invasion in the CD-susceptible genotype, NOD2(-/-), and reduced dysbiosis in ileitis-resistant CCR2(-/-) mice. Abrogating inflammation with the CD therapeutic anti-TNF-α-mAb tempered dysbiosis and bacterial invasion., Conclusions: Acute ileitis induces dysbiosis and proliferation of mucosally invasive E. coli, irrespective of trigger and genotype. The identification of CCR2 as a target for therapeutic intervention, and discovery that host genotype and therapeutic blockade of inflammation impact the threshold and extent of ileal dysbiosis are of high relevance to developing effective therapies for CD.

Oral infection of C57BL/6 mice with Toxoplasma gondii triggers severe necrosis in the ileum within 7-10 days of infection. Lesion development is mediated by Th-1 cytokines, CD4+ T cells, and subepithelial bacterial translocation. As such, these features share similarity to Crohn's disease. Recently, we uncovered a role for intraepithelial lymphocytes (IELs) in mediating pathology after Toxoplasma infection. We show here that αβ and not γδ T-cell IELs mediate intestinal damage. By adoptive transfer of mucosal T cells into naive Rag1⁻/⁻ mice, we demonstrate that IELs do not function alone to cause inflammatory lesions, but act with CD4+ T lymphocytes from the lamina propria (LP). Furthermore, recipient mice pretreated with broad-spectrum antibiotics to eliminate intestinal flora resisted intestinal disease after transfer of IELs and LP lymphocytes. Our data provide valuable new insights into the mechanisms of intestinal inflammation, findings that have important implications for understanding human inflammatory bowel disease.

Neutrophils play a major role in the innate immune system and are normally considered to be short-lived effector cells that exert anti-microbial activity and sometimes immunopathology. Here, we show that these cells possess an additional function as professional antigen-presenting cells capable of priming a T(h)1- and T(h)17-acquired immune response. Using flow cytometry, fluorescence microscopy and western blotting, we show that mouse neutrophils express MHC class II and co-stimulatory molecules CD80 and CD86 after T-cell co-incubation. Neutrophils pulsed with ovalbumin (OVA) process and present peptide antigen to OVA-specific T cells in an MHC class II-dependent manner. Importantly, we demonstrate that neutrophils can prime antigen-specific T(h)1 and T(h)17 immune responses even without the addition of exogenous cytokines to cell cultures.

The objective was to study the impact of a practice-based quality improvement program on practice teams' care for patients who have increased risk of cardiovascular disease. A total of 54 team members from 18 internal medicine practices participated in an educational program that used a pre-post intervention study design and focused on measures related to cardiovascular risk factors. The program involved live instruction, faculty-led conference calls, practice data collection, and progress reports detailing practices' improvement strategies. Data on 817 patients were reported. Practices showed significant improvement in counseling for diet (70% to 78%), exercise (67% to 74%), and weight loss (64% to 72%). Use of aspirin (53% to 64%) and statins (83% to 89%) also showed significant improvement. Administration of flu vaccine increased significantly from 51% to 54%. Improvements in patient counseling and medication management, if sustained, should lead to fewer cardiovascular events. However, program duration did not allow the capture of outcomes measures improvement.

This study sought to examine the effects of training mands on the emergence of tacts with the same response forms. Results indicated that training adjective sets as mands resulted in the emergence of adjective sets as tacts under modified, but not standard, antecedent conditions. The findings suggested that the apparent functional independence of mands and tacts may be explained by a lack of appropriate antecedent control over responding.

Toll-like receptor (TLR)/MyD88 signalling has emerged as a major pathway of pathogen recognition in the innate immune system. Here, we review recent data that begin to show how this pathway controls the immune response to protozoan infection, with particular emphasis on the opportunistic pathogen Toxoplasma gondii. The various ways that the parasite activates and suppresses TLR/MyD88 signalling defines several key principals that illuminate the complexities of the host-pathogen interaction. We also speculate how TLR/MyD88 signalling might be exploited to provide protection against Toxoplasma, as well as other protozoa and infection in general.

Macrophages infected with the opportunistic protozoan Toxoplasma gondii are unable to up-regulate many proinflammatory cytokine genes, including TNF (TNF-alpha), upon stimulation with LPS and other TLR ligands. In this study, we examined the influence of T. gondii on transcription factors associated with TNF-alpha transcription, as well as phosphorylation and acetylation of histone H3 at distal and proximal regions of the TNF-alpha promoter. During LPS stimulation, we found that Toxoplasma blocks nuclear accumulation of transcription factor c-Jun, but not that of cAMP response element-binding protein or NF-kappaB. However, chromatin immunoprecipitation studies revealed that binding of all of these transcription factors to the TNF promoter was decreased by T. gondii infection. Furthermore, the parasite blocked LPS-induced Ser(10) phosphorylation and Lys(9)/Lys(14) acetylation of histone H3 molecules associated with distal and proximal regions of the TNF-alpha promoter. Our results show that Toxoplasma inhibits TNF-alpha transcription by interfering with chromatin remodeling events required for transcriptional activation at the TNF promoter, revealing a new mechanism by which a eukaryotic pathogen incapacitates proinflammatory cytokine production during infection.

TLR adaptor MyD88 activation is important in host resistance to Toxoplasma gondii during i.p. infection, but the function of this signaling pathway during oral infection, in which mucosal immunity assumes a predominant role, has not been examined. In this study, we show that MyD88(-/-) mice fail to control the parasite and succumb within 2 wk of oral infection. Early during infection, T cell IFN-gamma production, recruitment of neutrophils and induction of p47 GTPase IGTP (Irgm3) in the intestinal mucosa were dependent upon functional MyD88. Unexpectedly, these responses were MyD88-independent later during acute infection. In particular, CD4(+) T cell IFN-gamma reached normal levels independently of MyD88, despite continued absence of IL-12 in these animals. The i.p. vaccination of MyD88(-/-) mice with an avirulent T. gondii uracil auxotroph elicited robust IFN-gamma responses and protective immunity to challenge with a high virulence T. gondii strain. Our results demonstrate that MyD88 is required to control Toxoplasma infection, but that the parasite can trigger adaptive immunity without the need for this TLR adaptor molecule.

Objective: The American College of Physicians (ACP) developed a quality improvement (QI) program to address deficiencies in immunization rates, primarily for influenza, and determine the program's impact on adult immunization., Design: An interventional study using a pre-post design. Three cohorts of physician practices were invited from a random sample of 2000 to attend 1-day training sessions in 2004, 2005, and 2006 in Philadelphia, Pennsylvania. Participants performed data abstractions and developed QI plans. Baseline data were compared with follow-up., Results: Fifty-five practices received training, 39 practices provided baseline data, and 11 practices provided follow-up data, reporting on 4208 patients. Baseline rates for influenza were 51% for cohort 1, 42% for cohort 2, and 59% for cohort 3. Follow-up data collection is ongoing., Conclusion: Rates increased for patients with private insurance and patients aged 50 to 64 years, suggesting that many providers attending the training were unaware of the need to vaccinate these patients.