Analysis of narrative assessments of internal medicine resident performance: are there differences associated with gender or race and ethnicity?

BACKGROUND: Equitable assessment is critical in competency-based medical education. This study explores differences in key characteristics of qualitative assessments (i.e., narrative comments or assessment feedback) of internal medicine postgraduate resident performance associated with gender and race and ethnicity. METHODS: Analysis of narrative comments included in faculty assessments of resident performance from six internal medicine residency programs was conducted. Content analysis was used to assess two key characteristics of comments- valence (overall positive or negative orientation) and specificity (detailed nature and actionability of comment) - via a blinded, multi-analyst approach. Differences in comment valence and specificity with gender and race and ethnicity were assessed using multilevel regression, controlling for multiple covariates including quantitative competency ratings. RESULTS: Data included 3,383 evaluations with narrative comments by 597 faculty of 698 residents, including 45% of comments about women residents and 13.2% about residents who identified with race and ethnicities underrepresented in medicine. Most comments were moderately specific and positive. Comments about women residents were more positive (estimate 0.06, p 0.045) but less specific (estimate - 0.07, p 0.002) compared to men. Women residents were more likely to receive non-specific, weakly specific or no comments (adjusted OR 1.29, p 0.012) and less likely to receive highly specific comments (adjusted OR 0.71, p 0.003) or comments with specific examples of things done well or areas for growth (adjusted OR 0.74, p 0.003) than men. Gendered differences in comment specificity and valence were most notable early in training. Comment specificity and valence did not differ with resident race and ethnicity (specificity: estimate 0.03, p 0.32; valence: estimate - 0.05, p 0.26) or faculty gender (specificity: estimate 0.06, p 0.15; valence: estimate 0.02 p 0.54). CONCLUSION: There were significant differences in the specificity and valence of qualitative assessments associated with resident gender with women receiving more praising but less specific and actionable comments. This suggests a lost opportunity for well-rounded assessment feedback to the disadvantage of women.

Association Between Biliary Pathogens, Surgical Site Infection, and Pancreatic Fistula: Results of a Randomized Trial of Perioperative Antibiotic Prophylaxis in Patients Undergoing Pancreatoduodenectomy.

OBJECTIVE: To establish the association between bactibilia and postoperative complications when stratified by perioperative antibiotic prophylaxis. BACKGROUND: Patients undergoing pancreatoduodenectomy experience high rates of surgical site infection (SSI) and clinically relevant postoperative pancreatic fistula (CR-POPF). Contaminated bile is known to be associated with SSI, but the role of antibiotic prophylaxis in mitigation of infectious risks is ill-defined. METHODS: Intraoperative bile cultures (IOBCs) were collected as an adjunct to a randomized phase 3 clinical trial comparing piperacillin-tazobactam with cefoxitin as perioperative prophylaxis in patients undergoing pancreatoduodenectomy. After compilation of IOBC data, associations between culture results, SSI, and CR-POPF were assessed using logistic regression stratified by the presence of a preoperative biliary stent. RESULTS: Of 778 participants in the clinical trial, IOBC were available for 247 participants. Overall, 68 (27.5%) grew no organisms, 37 (15.0%) grew 1 organism, and 142 (57.5%) were polymicrobial. Organisms resistant to cefoxitin but not piperacillin-tazobactam were present in 95 patients (45.2%). The presence of cefoxitin-resistant organisms, 92.6% of which contained either Enterobacter spp. or Enterococcus spp., was associated with the development of SSI in participants treated with cefoxitin [53.5% vs 25.0%; odds ratio (OR)=3.44, 95% CI: 1.50-7.91; P =0.004] but not those treated with piperacillin-tazobactam (13.5% vs 27.0%; OR=0.42, 95% CI: 0.14-1.29; P =0.128). Similarly, cefoxitin-resistant organisms were associated with CR-POPF in participants treated with cefoxitin (24.1% vs 5.8%; OR=3.45, 95% CI: 1.22-9.74; P =0.017) but not those treated with piperacillin-tazobactam (5.4% vs 4.8%; OR=0.92, 95% CI: 0.30-2.80; P =0.888). CONCLUSIONS: Previously observed reductions in SSI and CR-POPF in patients that received piperacillin-tazobactam antibiotic prophylaxis are potentially mediated by biliary pathogens that are cefoxitin resistant, specifically Enterobacter spp. and Enterococcus spp.

Exploring gender and thematic differences in qualitative assessments of internal medicine resident performance.

INTRODUCTION: Evidence suggests gender disparities in medical education assessment, including differences in ratings of competency and narrative comments provided in resident performance assessments. This study explores how gender manifests within the content of qualitative assessments (i.e., narrative comments or performance feedback) of resident performance. METHODS: Qualitative content analysis was used to explore gender-based differences in narrative comments included in faculty assessments of resident performance during inpatient medicine rotations at six Internal Medicine residency programs, 2016-2017. A blinded, multi-analyst approach was employed to identify themes across comments. Patterns in themes with resident gender and post-graduate year (PGY) were explored, focusing on PGY2 and PGY3 when residents are serving in the team leader role. RESULTS: Data included 3,383 evaluations with narrative comments of 385 men (55.2%) and 313 women residents (44.8%). There were thematic differences in narrative comments received by men and women residents and how these themes manifested within comments changed with training time. Compared to men, comments about women had a persistent relationship-orientation and emphasized confidence over training including as interns and in PGY2 and PGY3, when serving as team leader. The relationship-orientation was characterized not only by the residents' communal attributes but also their interpersonal and communication skills, including efforts supporting others and establishing the tone for the team. Comments about women residents often highlighted confidence, including recommendations around behaviors that convey confidence in decision-making and team leadership. DISCUSSION: There were gender-based thematic differences in qualitative assessments. Comments about women resident team leaders highlight relationship building skills and urge confidence and actions that convey confidence as team leader. Persistent attention to communal skills suggests gendered expectations for women resident team leaders and a lost opportunity for well-rounded feedback to the disadvantage of women residents. These findings may inform interventions to promote equitable assessment, such as providing feedback across the competencies.

Piperacillin-Tazobactam Compared With Cefoxitin as Antimicrobial Prophylaxis for Pancreatoduodenectomy: A Randomized Clinical Trial.

Importance: Despite improvements in perioperative mortality, the incidence of postoperative surgical site infection (SSI) remains high after pancreatoduodenectomy. The effect of broad-spectrum antimicrobial surgical prophylaxis in reducing SSI is poorly understood. Objective: To define the effect of broad-spectrum perioperative antimicrobial prophylaxis on postoperative SSI incidence compared with standard care antibiotics. Design, Setting, and Participants: Pragmatic, open-label, multicenter, randomized phase 3 clinical trial at 26 hospitals across the US and Canada. Participants were enrolled between November 2017 and August 2021, with follow-up through December 2021. Adults undergoing open pancreatoduodenectomy for any indication were eligible. Individuals were excluded if they had allergies to study medications, active infections, chronic steroid use, significant kidney dysfunction, or were pregnant or breastfeeding. Participants were block randomized in a 1:1 ratio and stratified by the presence of a preoperative biliary stent. Participants, investigators, and statisticians analyzing trial data were unblinded to treatment assignment. Intervention: The intervention group received piperacillin-tazobactam (3.375 or 4 g intravenously) as perioperative antimicrobial prophylaxis, while the control group received cefoxitin (2 g intravenously; standard care). Main Outcomes and Measures: The primary outcome was development of postoperative SSI within 30 days. Secondary end points included 30-day mortality, development of clinically relevant postoperative pancreatic fistula, and sepsis. All data were collected as part of the American College of Surgeons National Surgical Quality Improvement Program. Results: The trial was terminated at an interim analysis on the basis of a predefined stopping rule. Of 778 participants (378 in the piperacillin-tazobactam group [median age, 66.8 y; 233 {61.6%} men] and 400 in the cefoxitin group [median age, 68.0 y; 223 {55.8%} men]), the percentage with SSI at 30 days was lower in the perioperative piperacillin-tazobactam vs cefoxitin group (19.8% vs 32.8%; absolute difference, -13.0% [95% CI, -19.1% to -6.9%]; P < .001). Participants treated with piperacillin-tazobactam, vs cefoxitin, had lower rates of postoperative sepsis (4.2% vs 7.5%; difference, -3.3% [95% CI, -6.6% to 0.0%]; P = .02) and clinically relevant postoperative pancreatic fistula (12.7% vs 19.0%; difference, -6.3% [95% CI, -11.4% to -1.2%]; P = .03). Mortality rates at 30 days were 1.3% (5/378) among participants treated with piperacillin-tazobactam and 2.5% (10/400) among those receiving cefoxitin (difference, -1.2% [95% CI, -3.1% to 0.7%]; P = .32). Conclusions and Relevance: In participants undergoing open pancreatoduodenectomy, use of piperacillin-tazobactam as perioperative prophylaxis reduced postoperative SSI, pancreatic fistula, and multiple downstream sequelae of SSI. The findings support the use of piperacillin-tazobactam as standard care for open pancreatoduodenectomy. Trial Registration: ClinicalTrials.gov Identifier: NCT03269994.

Association of Gender and Race/Ethnicity with Internal Medicine In-Training Examination Performance in Graduate Medical Education.

BACKGROUND: Disparities in objective assessments in graduate medical education such as the In-Training Examination (ITE) that disadvantage women and those self-identifying with race/ethnicities underrepresented in medicine (URiM) are of concern. OBJECTIVE: Examine ITE trends longitudinally across post-graduate year (PGY) with gender and race/ethnicity. DESIGN: Longitudinal analysis of resident ITE metrics at 7 internal medicine residency programs, 2014-2019. ITE trends across PGY of women and URiM residents compared to non-URiM men assessed via ANOVA. Those with ITE scores associated with less than 90% probability of passing the American Board of Internal Medicine certification exam (ABIM-CE) were identified and odds of being identified as at-risk between groups were assessed with chi square. PARTICIPANTS: A total of 689 IM residents, including 330 women and URiM residents (48%). MAIN MEASURES: ITE score KEY RESULTS: There was a significant difference in ITE score across PGY for women and URiM residents compared to non-URiM men (F(2, 1321) 4.46, p=0.011). Adjusting for program, calendar year, and baseline ITE, women and URiM residents had smaller ITE score gains (adjusted mean change in score between PGY1 and PGY3 (se), non-URiM men 13.1 (0.25) vs women and URiM residents 11.4 (0.28), p<0.001). Women and URiM residents had greater odds of being at potential risk for not passing the ABIM-CE (OR 1.75, 95% CI 1.10 to 2.78) with greatest odds in PGY3 (OR 3.13, 95% CI 1.54 to 6.37). CONCLUSION: Differences in ITE over training were associated with resident gender and race/ethnicity. Women and URiM residents had smaller ITE score gains across PGY translating into greater odds of potentially being seen as at-risk for not passing the ABIM-CE. Differences in ITE over training may reflect differences in experiences of women and URiM residents during training and may lead to further disparities.

Escherichia coli recombinant expression of SARS-CoV-2 protein fragments.

We have developed a method for the inexpensive, high-level expression of antigenic protein fragments of SARS-CoV-2 proteins in Escherichia coli. Our approach uses the thermophilic family 9 carbohydrate-binding module (CBM9) as an N-terminal carrier protein and affinity tag. The CBM9 module was joined to SARS-CoV-2 protein fragments via a flexible proline-threonine linker, which proved to be resistant to E. coli proteases. Two CBM9-spike protein fragment fusion proteins and one CBM9-nucleocapsid fragment fusion protein largely resisted protease degradation, while most of the CBM9 fusion proteins were degraded at some site in the SARS-CoV-2 protein fragment. All of the fusion proteins were highly expressed in E. coli and the CBM9-ID-H1 fusion protein was shown to yield 122 mg/L of purified product. Three purified CBM9-SARS-CoV-2 fusion proteins were tested and found to bind antibodies directed to the appropriate SARS-CoV-2 antigenic regions. The largest intact CBM9 fusion protein, CBM9-ID-H1, incorporates spike protein amino acids 540-588, which is a conserved region overlapping and C-terminal to the receptor binding domain that is widely recognized by human convalescent sera and contains a putative protective epitope.

Hyperamylasemia grade versus drain fluid amylase: which better predicts pancreatectomy outcomes?

BACKGROUND: The clinical importance of postoperative hyperamylasemia (POHA) grade is unknown. Our objectives were to evaluate the association of POHA grade with clinically relevant postoperative pancreatic fistula (CR-POPF) and compare its prognostic utility against postoperative day 1 drain fluid amylase (DFA-1). METHODS: Patients who underwent pancreatectomy from January 2019 through March 2020 were identified in the ACS NSQIP pancreatectomy-targeted dataset. POHA grade was assigned using post-operative serum amylase and clinical sequelae. The primary outcome was CR-POPF within 30 days. The association of POHA grade with CR-POPF was assessed using multivariable logistic regression, and c-statistics were used to compare POHA grade versus DFA-1. RESULTS: POHA occurred in 520 patients at 98 hospitals, including 261 (50.2%) with grade A, 234 (45.0%) with grade B, and 25 (4.8%) with grade C POHA. CR-POPFs were increased among patients with grade B (66.2%, OR 9.28 [5.84-14.73]) and C (68.0%, OR 10.50 [3.77-29.26]) versus grade A POHA (19.2%). POHA-inclusive models better predicted CR-POPF than those with DFA-1 alone (p < 0.002) and models with both predictors outperformed POHA alone (p = 0.039). CONCLUSION: POHA grade represents a measure of post-pancreatectomy outcomes that predicts CR-POPF and outperforms DFA-1 but must be aligned with new international definitions.

Optimal Pancreatic Surgery: Are We Making Progress in North America?

OBJECTIVE: Our aims were to assess North American trends in the management of patients undergoing pancreatoduodenectomy (PD) and distal pancreatectomy (DP), and to quantify the delivery of optimal pancreatic surgery. BACKGROUND: Morbidity after pancreatectomy remains unacceptably high. Recent literature suggests that composite measures may more accurately define surgical quality. METHODS: The 2013 to 2017 American College of Surgeons National Surgical Quality Improvement Program Participant Use Files were queried to identify patients undergoing PD (N = 16,222) and DP (N = 7946). Patient, process, procedure, and 30-day postoperative outcome variables were analyzed over time. Optimal pancreatic surgery was defined as the absence of postoperative mortality, serious morbidity, percutaneous drainage, and reoperation while achieving a length of stay equal to or less than the 75th percentile (12 days for PD and 7 days for DP) with no readmissions. Risk-adjusted time-trend analyses were performed using logistic regression, and the threshold for statistical significance was P ≤ 0.05. RESULTS: The use of minimally invasive PD did not change over time, but robotic PD increased (2.5 to 4.2%; P < 0.001) and laparoscopic PD decreased (5.8% to 4.3%; P < 0.02). Operative times decreased (P < 0.05) and fewer transfusions were administered (P < 0.001). The percentage of patients with a drain fluid amylase checked on postoperative day 1 increased (P < 0.001), and a greater percentage of surgical drains were removed by postoperative day 3 (P < 0.001). Overall morbidity (P < 0.02), mortality (P < 0.05), and postoperative length of stay (P = 0.002) decreased. Finally, the rate of optimal pancreatic surgery increased for PD (53.7% to 56.9%; P < 0.01) and DP (53.3% to 58.5%; P < 0.001), and alspo for patients with pancreatic cancer (P < 0.01). CONCLUSIONS: From 2013 to 2017, pre, intra, and perioperative pancreatectomy processes have evolved, and multiple postoperative outcomes have improved. Thus, in 4 years, optimal pancreatic surgery in North America has increased by 3% to 5%.

Bronchial or Pulmonary Artery Chemoembolization for Unresectable and Unablatable Lung Metastases: A Phase I Clinical Trial.

Background Lung chemoembolization is an emerging treatment option for lung tumors, but the optimal embolic, drug, and technique are unknown. Purpose To determine the technical success rate and safety of bronchial or pulmonary artery chemoembolization of lung metastases using ethiodized oil, mitomycin, and microspheres. Materials and Methods Patients with unresectable and unablatable lung, endobronchial, or mediastinal metastases, who failed systemic chemotherapy, were enrolled in this prospective, single-center, single-arm, phase I clinical trial (December 2019-September 2020). Pulmonary and bronchial angiography was performed to determine the blood supply to the lung metastases. Based on the angiographic findings, bronchial or pulmonary artery chemoembolization was performed using an ethiodized oil and mitomycin emulsion, followed by microspheres. The primary objectives were technical success rate and safety, according to the National Cancer Institute Common Terminology Criteria for Adverse Events. CIs of proportions were estimated with the equal-tailed Jeffreys prior interval, and correlations were evaluated with the Spearman test. Results Ten participants (median age, 60 years; interquartile range, 52-70 years; six women) were evaluated. Nine of the 10 participants (90%) had lung metastases supplied by the bronchial artery, and one of the 10 participants (10%) had lung metastases supplied by the pulmonary artery. The technical success rate of intratumoral drug delivery was 10 of 10 (100%) (95% CI: 78, 100). There were no severe adverse events (95% CI: 0, 22). The response rate of treated tumors was one of 10 (10%) according to the Response Evaluation Criteria in Solid Tumors and four of 10 (40%) according to the PET Response Criteria in Solid Tumors. Ethiodized oil retention at 4-6 weeks was correlated with reduced tumor size (ρ = -0.83, P = .003) and metabolic activity (ρ = -0.71, P = .03). Pharmacokinetics showed that 45% of the mitomycin dose underwent burst release in 2 minutes, and 55% of the dose was retained intratumorally with a half-life of more than 5 hours. The initial tumor-to-plasma ratio of mitomycin concentration was 380. Conclusion Lung chemoembolization was technically successful for the treatment of lung, mediastinal, and endobronchial metastases, with no severe adverse events. Clinical trial registration no. NCT04200417 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Georgiades et al in this issue.

Association of Patient-reported Experiences and Surgical Outcomes Among Group Practices: Retrospective Cohort Study.

OBJECTIVE: The aim of the study was to determine the association of patient-reported experiences (PREs) and risk-adjusted surgical outcomes among group practices. BACKGROUND: The Centers for Medicare and Medicaid Services required large group practices to submit PREs data for successful participation in the Physician Quality Reporting System (PQRS) using the Consumer Assessment of Healthcare Providers and Systems for PQRS survey. Whether these PREs data correlate with perioperative outcomes remains ill defined. METHODS: Operations between January 1, 2014 and December 31, 2016 in the American College of Surgeons' National Surgical Quality Improvement Program registry were merged with 2015 Consumer Assessment of Healthcare Providers and Systems for PQRS survey data. Hierarchical logistic models were constructed to estimate associations between 7 subscales and 1 composite score of PREs and 30-day morbidity, unplanned readmission, and unplanned reoperation, separately, while adjusting for patient- and procedure mix. RESULTS: Among 328 group practices identified, patients reported their experiences with clinician communication the highest (mean ±â€Šstandard deviation, 82.66 ±â€Š3.10), and with attention to medication cost the lowest (25.96 ±â€Š5.14). The mean composite score was 61.08 (±6.66). On multivariable analyses, better PREs scores regarding medication cost, between-visit communication, and the composite score of experience were each associated with 4% decreased odds of morbidity [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.92-0.99], readmission (OR 0.96, 95% CI 0.93-0.99), and reoperation (OR 0.96, 95% CI 0.93-0.99), respectively. In sensitivity analyses, better between-visit communication remained significantly associated with fewer readmissions. CONCLUSIONS: In these data, patients' report of better between-visit communication was associated with fewer readmissions. More sensitive, surgery-specific PRE assessments may reveal additional unique insights for improving the quality of surgical care.

Wound protectors mitigate superficial surgical site infections after pancreatoduodenectomy.

BACKGROUND: Whether the choice of antibiotic prophylaxis, the type of incision, or the use of wound protectors decreases surgical site infections (SSIs) in patients undergoing pancreatoduodenectomy (PD) remains unknown. METHODS: Patients undergoing open, elective PD between January 1, 2016 and June 30, 2017 were identified from the American College of Surgeons' National Surgical Quality Improvement Program registry. Multivariable logistic regression models were constructed to determine the association of antibiotic prophylaxis type, incision type, and wound protector use on the incidence of any, superficial, and organ/space SSIs, and to profile hospitals. RESULTS: Overall, 5969 patients were included from 140 hospitals. The overall rate of SSI was 20.3% (n = 1213). Superficial SSIs occurred in 432 (7.2%) patients and organ/space SSIs in 841 (14.1%). Wound protector use was associated with 23% lower odds of experiencing any SSIs (OR 0.77, 95% CI 0.60-0.98), reflective of the decreased odds associated with superficial SSIs (OR 0.65, 95% CI 0.44-0.97), but not organ/space SSIs (OR 0.89, 95% CI 0.68-1.17). Highest-performing hospitals frequently utilized broad-spectrum antibiotics, midline incisions, and wound protectors. CONCLUSION: Wound protectors reduced superficial, but not organ/space, infections in patients undergoing pancreatoduodenectomy. Routine use of wound protectors in patients undergoing proximal pancreatectomy is recommended.

Assessing the influence of experience in pancreatic surgery: a risk-adjusted analysis using the American College of Surgeons NSQIP database.

BACKGROUND: The association between higher surgical volume and better perioperative outcomes after pancreatectomy has been extensively demonstrated. However, how different notions of experience impact outcomes of surgeons operating within high-quality scenarios remains unclear. METHODS: Self-reported experience parameters from ACS-NSQIP HPB-Collaborative surgeons were merged with 2014-2016 ACS-NSQIP clinical data. The association of various experience parameters with outcomes was investigated through uni- and multivariable analyses. Hierarchical regression assessed surgeon performance. RESULTS: 111/151 HPB-Collaborative surgeons provided responses (73.5%). Compared to the other 532 ACS-NSQIP surgeons performing pancreatectomy, HPB-Collaborative surgeons performed 7692/16,239 of the overall pancreatectomies (47.3%), with improved outcomes of serious morbidity, pancreatic fistula, reoperation, duration of stay and readmissions. Median age of respondents was 49 years and 92.8% were fellowship-trained. Median career and annual pancreatectomy volume were 400 and 35, respectively; median annual institutional volume was 100 resections. On unadjusted analyses, several aspects of experience were associated with the outcomes studied, especially for pancreatoduodenectomy; however, none remained significant after multivariable adjustment. Surgeons' profiling showed substantial homogeneity in performance for both pancreatoduodenectomy and distal pancreatectomy. CONCLUSIONS: Contemporary data shows that for surgeons operating in high quality settings clinical outcomes are largely independent of indicators of greater experience.

Adolescent food restriction in rats alters prefrontal cortex microglia in an experience-dependent manner.

Microglia are resident immune cells of the brain that can regulate neural communication and excitability. Any environmental influence on microglial activity has the potential to alter subsequent neural physiology and behavior. Within the prefrontal cortex, several types of stressors have been shown to increase microglial expression of activation markers such as ionized calcium-binding adapter molecule-1 (Iba-1), which suggests altered microglial activity. Recent reports in rodents suggest that exposure to forms of early-life stress such as maternal separation can alter microglial responsivity to subsequent challenges. Several learning paradigms used in rodents require food restriction to provoke motivational states that facilitate approach behaviors. Here, we tested whether food restriction (increasing from 13 g/day-23 g/day in males and 10 g/day-20 g/day in females, which reduced body weight to 72-84% free-fed weight) in adolescent rats is a sufficient challenge to affect microglial Iba-1 expression, and whether previous exposure to postnatal maternal separation influenced microglial outcomes. We measured prefrontal cortex Iba-1 expression and microglial morphology after 20 days of ad libitum or restricted food availability in males and females with or without exposure to maternal separation. Food-restricted animals displayed higher levels of Iba-1 in the prefrontal cortex, with hyper-ramified microglial morphology in maternally separated males and control females, compared to those that were free-fed. Together, our data provide evidence that food restriction paradigms may have unintended effects in some behavioral protocols.

Minimally invasive hepatopancreatobiliary surgery in North America: an ACS-NSQIP analysis of predictors of conversion for laparoscopic and robotic pancreatectomy and hepatectomy.

BACKGROUND: Procedural conversion rates represent an important aspect of the feasibility of minimally invasive surgical (MIS) approaches. This study aimed to outline the rates and predictors of procedural completion/conversion for MIS hepatectomy and pancreatectomy. METHODS: All 2014 ACS-NSQIP laparoscopic and robotic hepatectomy and pancreatectomy procedures were identified and grouped into pure, open assist, or unplanned conversion to open. Risk adjusted multinomial logistic regression models were generated with completion (Pure) set as the primary outcome. RESULTS: 1667 (laparoscopic = 1360, robotic = 307) resections were captured. After risk adjustment, robotic DP was associated with similar open assist (relative risk ratio -1.9%, P = 0.602), but lower unplanned conversion (-8.2%, P = 0.004) and open assist + unplanned conversion (-10.1%, P = 0.015) compared to laparoscopic DP; while robotic PD was associated with lower open assist (-22.2%, P < 0.001), unplanned conversions (-15%, P = 0.006) and open assist + unplanned conversions (-37.2, P < 0.001) compared to laparoscopic PD. The robotic and laparoscopic approaches to hepatectomy were not associated with differences in pure MIS completion rates (P = NS) after risk adjustment. CONCLUSIONS: The robotic approach to pancreatectomy was associated with higher rates of pure MIS completion compared to laparoscopy, whereas no difference in MIS completion rates was noted for robotic versus laparoscopic hepatectomy.

Cell-Free Synthesis of a Functional Membrane Transporter into a Tethered Bilayer Lipid Membrane.

Eukaryotic cell-free synthesis was used to incorporate the large and complex multispan plant membrane transporter Bot1 in a functional form into a tethered bilayer lipid membrane. The electrical properties of the protein-functionalized tethered bilayer were measured using electrochemical impedance spectroscopy and revealed a pH-dependent transport of borate ions through the protein. The efficacy of the protein synthesis has been evaluated using immunoblot analysis.

Patterns of hepatic resections in North America: use of concurrent partial resections and ablations.

BACKGROUND: National registries have not adequately captured concurrent partial hepatic resections or ablations. Therefore, the aim of this analysis was to describe the patterns of concurrent partial resections and ablations in North America. METHODS: Patients undergoing a hepatic resection were identified using the American College of Surgeons-National Surgical Quality Improvement Program Targeted Hepatectomy database. Perioperative outcomes were compared for patients undergoing concurrent "wedge" resections and/or ablations and other subsets. RESULTS: A total of 2714 patients were identified who met inclusion criteria. Major hepatectomy was performed in 1037 patients (38.2%) while partial lobectomy was performed in 1677 (61.8%) patients. Concurrent "wedge" hepatic resections and ablations were undertaken in 56.0% and 14.2% of patients, respectively, and were more frequently performed among patients undergoing a partial lobectomy and among patients undergoing surgery for colorectal liver metastasis (both p < 0.001). While associated with a decreased incidence of postoperative complications (p = 0.027) and liver failure (p = 0.031) among patients undergoing a major hepatectomy, concurrent therapies were associated with comparable 30-day outcomes for patients undergoing partial lobectomy. CONCLUSION: Concurrent "wedge" hepatic resections and ablations are performed in 56.0% and 14.2%, respectively of patients undergoing hepatectomy. Concurrent procedures were not associated with worse clinical outcomes.

The role of hepatic and splenic macrophages in E. coli-induced memory impairments in aged rats.

Bi-directional communication between the peripheral and central nervous systems has been extensively demonstrated. Aged rats exhibit a prolonged proinflammatory response in the hippocampus region of the brain following a peripheral bacterial infection, and this response in turn causes robust memory declines. Here we aimed to determine whether hepatic or splenic macrophages play a role in the maintenance of this central response. Proinflammatory cytokines measured in liver and spleen four days following an Escherichia coli infection revealed a potentiated proinflammatory response in liver, and to a lesser extent in spleen, in aged relative to young rats. To determine whether this potentiated response was caused by impaired bacterial clearance in these organs, E. coli colony forming units in liver and spleen were measured 4 days after infection, and there were no difference between young and aged rats in either organ. No E. coli was detected in the hippocampus, eliminating the possibility that the aged blood brain barrier allowed E. coli to enter the brain. Depletion of hepatic and splenic macrophages with clodronate-encapsulated liposomes effectively eliminated the proinflammatory response to E. coli at four days in both organs. However, this treatment failed to reduce the proinflammatory response in the hippocampus. Moreover, depletion of peripheral macrophages from liver and spleen did not prevent E. coli-induced memory impairment. These data strongly suggest that hepatic and splenic macrophages do not play a major role in the long-lasting maintenance of the proinflammatory response in the hippocampus of aged rats following a bacterial infection, or the memory declines that this response produces.

Interaction of silver nanoparticles with tethered bilayer lipid membranes.

Silver nanoparticles are well-known for their antibacterial properties. However, the detailed mechanism describing the interaction between the nanoparticles and a cell membrane is not fully understood, which can impede the use of the particles in biomedical applications. Here, a tethered bilayer lipid membrane has been used as a model system to mimic a natural membrane and to study the effect of exposure to small silver nanoparticles with diameters of about 2 nm. The solid supported membrane architecture allowed for the application of surface analytical techniques such as electrochemical impedance spectroscopy and atomic force microscopy. Exposure of the membrane to solutions of the silver nanoparticles led to a small but completely reversible perturbation of the lipid bilayer.