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Computer Programming: A New Trick Worth Learning Reply ANNALS OF THORACIC SURGERY Bender, E., Rizzo, M. G. 2020; 110 (2): 753?54
View details for Web of Science ID 000553847700037
Does Tweeting Improve Citations? One-Year Results from the TSSMN Prospective Randomized Trial. The Annals of thoracic surgery Luc, J. G., Archer, M. A., Arora, R. C., Bender, E. M., Blitz, A., Cooke, D. T., Hlci, T. N., Kidane, B., Ouzounian, M., Varghese, T. K., Antonoff, M. B. 2020
Abstract

BACKGROUND: The Thoracic Surgery Social Media Network (TSSMN) is a collaborative effort of leading journals in cardiothoracic surgery to highlight publications via social media. This study aims to evaluate the 1-year results of a prospective randomized social media trial to determine the effect of tweeting on subsequent citations and non-traditional bibliometrics.METHODS: A total of 112 representative original articles were randomized 1:1 to be tweeted via TSSMN or a control (non-tweeted) group. Measured endpoints included citations at 1-year compared to baseline, as well as article-level metrics (Altmetric score) and Twitter analytics. Independent predictors of citations were identified through univariable and multivariable regression analyses.RESULTS: When compared to control articles, tweeted articles achieved significantly greater increase in Altmetric scores (Tweeted 9.4�5.8 vs. Non-Tweeted 1.0�1.8, p<0.001), Altmetric score percentiles relative to articles of similar age from each respective journal (Tweeted 76.0�9.1%ile vs. Non-Tweeted 13.8�22.7%ile, p<0.001), with greater change in citations at 1 year (Tweeted +3.1�2.4 vs. Non-Tweeted +0.7�1.3, p<0.001). Multivariable analysis showed that independent predictors of citations were randomization to tweeting (OR 9.50; 95%CI 3.30-27.35, p<0.001), Altmetric score (OR 1.32; 95%CI 1.15-1.50, p<0.001), open-access status (OR 1.56; 95%CI 1.21-1.78, p<0.001), and exposure to a larger number of Twitter followers as quantified by impressions (OR 1.30, 95%CI 1.10-1.49, p<0.001).CONCLUSIONS: One-year follow-up of this TSSMN prospective randomized trial importantly demonstrates that tweeting results in significantly more article citations over time, highlighting the durable scholarly impact of social media activity.

View details for DOI 10.1016/j.athoracsur.2020.04.065

View details for PubMedID 32504611
The Thoracic Surgery Social Media Network Experience During the COVID-19 Pandemic. The Annals of thoracic surgery Luc, J. G., Archer, M. A., Arora, R. C., Bender, E. M., Blitz, A., Cooke, D. T., Elde, S., Guy, T. S., Halpern, A. L., Harrington, C., Hlci, T. N., Kidane, B., Olive, J. K., Ouzounian, M., Stamp, N., Vervoort, D., Varghese, T. K., Antonoff, M. B. 2020
View details for DOI 10.1016/j.athoracsur.2020.05.006

View details for PubMedID 32425205
Computer Programming: A New Trick Worth Learning: Reply. The Annals of thoracic surgery Bender, E., Rizzo, M. G. 2020; 110 (2): 753?54
View details for DOI 10.1016/j.athoracsur.2020.01.045

View details for PubMedID 32135153
The Thoracic Surgery Social Media Network: Early experience and lessons learned. The Journal of thoracic and cardiovascular surgery Luc, J. G., Ouzounian, M., Bender, E. M., Blitz, A., Stamp, N. L., Varghese, T. K., Cooke, D. T., Antonoff, M. B. 2019
Abstract

BACKGROUND: The Thoracic Surgery Social Media Network (TSSMN) is a social media collaborative formed in 2015 by The Annals of Thoracic Surgery and The Journal of Thoracic and Cardiovascular Surgery to bring social media attention to key publications from both journals and to highlight major accomplishments in the specialty. Our aim is to describe TSSMN's preliminary experience and lessons learned.METHODS: Twitter analytics was used to obtain information regarding the @TSSMN Twitter handle and #TSSMN hashtag. TweetChat and general hashtag #TSSMN analytics were measured using Symplur (Symplur LLC, Los Angeles, Calif). A TSSMN Tweeter App was created, and its use and downloads were analyzed.RESULTS: Hashtag #TSSMN has a total of 17,181 tweets, 2100 users, and 32,226,280 impressions, with peaks in tweeting activity corresponding to TweetChats. Thirteen 1-hour TweetChats drew a total of 489 participants, 5195 total tweets, and 17,297,708 total impressions. The top demographic category of TweetChat participants included Doctors (47%), Advocates/Supports (11%), and Unknown (10%), with 3% characterized as patients. The TSSMN Tweeter iTunes App (Apple, Cupertino, Calif) was downloaded 3319 times with global representation. A total of 859 articles were viewed through the App, with 450 articles from The Annals of Thoracic Surgery and 409 from The Journal of Thoracic and Cardiovascular Surgery.CONCLUSIONS: We demonstrate that TSSMN further enhances the ability for the journals to connect with their readership and the cardiothoracic community. Ongoing studies to correlate social media attention with article reads, article-level metrics, citations, and journal impact factor are eagerly awaited.

View details for DOI 10.1016/j.jtcvs.2019.06.099

View details for PubMedID 31422854
Social Media Improves Cardiothoracic Surgery Literature Dissemination: Results of a Randomized Trial. The Annals of thoracic surgery Luc, J. G., Archer, M. A., Arora, R. C., Bender, E. M., Blitz, A., Cooke, D. T., Hlci, T. N., Kidane, B., Ouzounian, M., Varghese, T. K., Antonoff, M. B. 2019
Abstract

BACKGROUND: The Thoracic Surgery Social Media Network (TSSMN) represents a collaborative effort of leading journals in cardiothoracic surgery to highlight publications via social media, specifically Twitter. We conducted a prospective randomized trial to determine the effect of scheduled tweeting on non-traditional bibliometrics of dissemination.METHODS: A total of 112 representative original articles (2017-2018) were selected and randomized 1:1 to an intervention group to be tweeted via TSSMN or a control (non-tweeted) group. Four articles per day were tweeted by TSSMN delegates for 14 days. Primary endpoints included change in Altmetric score pre and post-tweet compared to controls. Secondary endpoints included change in Twitter analytics day one post-tweet and day seven post-tweet for each article compared to baseline.RESULTS: Tweeting via TSSMN significantly improved article Altmetric scores (Pre-tweet 1 vs. Post-tweet 8, p<0.001), Mendeley reads (Pre-tweet 1 vs. Post-tweet 3, p<0.001), and Twitter impressions (Day 1 post-tweet 1599 vs. Day 7 post-tweet 2296, p<0.001). Subgroup analysis demonstrates that incorporating photos into the tweets trended towards increased link clicks to the full-text article (p=0.08) whereas tweeting at 1pmEST and 9pmEST generated the highest and lowest audience reach (p=0.022), respectively. Articles published in adult cardiac surgery achieved the highest change in Altmetric score (p=0.028), Mendeley reads (p=0.028) and were more likely to be retweeted (p=0.042) than those published on education, general thoracic surgery, and congenital surgery.CONCLUSIONS: Social media highlights of scholarly literature via TSSMN Twitter activity improves article Altmetric scores, Mendeley reads, and Twitter analytics, with dissemination to a greater audience.

View details for DOI 10.1016/j.athoracsur.2019.06.062

View details for PubMedID 31404547
The Thoracic Surgery Social Media Network: Early Experience and Lessons Learned. The Annals of thoracic surgery Luc, J. G., Ouzounian, M., Bender, E. M., Blitz, A., Stamp, N. L., Varghese, T. K., Cooke, D. T., Antonoff, M. B. 2019
Abstract

BACKGROUND: The Thoracic Surgery Social Media Network (TSSMN) is a social media collaborative formed in 2015 by The Annals of Thoracic Surgery and The Journal of Thoracic and Cardiovascular Surgery to bring social media attention to key publications from both journals and to highlight major accomplishments in the specialty. Our aim is to describe TSSMN's preliminary experience and lessons learned.METHODS: Twitter analytics was used to obtain information regarding the @TSSMN Twitter handle and #TSSMN hashtag. TweetChat and general hashtag #TSSMN analytics were measured using Symplur (Symplur LLC, Los Angeles, CA). A TSSMN Tweeter App was created, and its use and downloads were analyzed.RESULTS: Hashtag #TSSMN has a total of 17,181 tweets, 2,100 users, and 32,226,280 impressions, with peaks in tweeting activity corresponding to TweetChats. Thirteen 1-hour TweetChats drew a total of 489 participants, 5195 total tweets, and 17,297,708 total impressions. The top demographic category of TweetChat participants included Doctors (47%), Advocates/Supports (11%), and Unknown (10%), with 3% characterized as patients. The TSSMN Tweeter iTunes App (Apple, Cupertino, CA) was downloaded 3319 times with global representation. A total of 859 articles were viewed through the App, with 450 articles from The Annals of Thoracic Surgery and 409 from The Journal of Thoracic and Cardiovascular Surgery.CONCLUSIONS: We demonstrate that TSSMN further enhances the ability for the journals to connect with their readership and the cardiothoracic community. Ongoing studies to correlate social media attention with article reads, article-level metrics, citations, and journal impact factor are eagerly awaited.

View details for DOI 10.1016/j.athoracsur.2019.06.011

View details for PubMedID 31422790
Surgeon as Programmer: Overcoming Obstacles to the Use of Modern Internet Technology for Cardiothoracic Surgery. The Annals of thoracic surgery Bender, E. M., Rizzo, M. G., Meyerson, S. L., Zwischenberger, J. B. 2019
Abstract

BACKGROUND: Leveraging internet technologies for academic activities can be complex and costly, costing tens of thousands of dollars. We describe our experience in eliminating financial barriers, realizing the potential for a new paradigm in applications for surgical education and practice.METHODS: After developing multiple surgical smartphone applications, we describe the acquisition of skillsets and resources to create state-of-the-art tools. Learning these techniques is non-trivial, but is attainable and clearly defined. We relate the trivial costs associated with complex software development, opening new doors to creative uses of technology.RESULTS: Acquisition of coding skills for smartphones took 100 hours. For a simple app without data storage, EuroSCORE, total programming time was 25 hours with no additional costs. The more complex autonomy evaluation app, Zwisch Me, has been used to evaluate over 1260 cases from 15 cardiothoracic surgery training programs between 1/2016 and 8/2018 using smartphone applications for data collection and a web dashboard for data reporting. During the first year, all enrollment and data reporting was done manually, at a cost of $124. Automating user enrollment and data reporting increased costs by roughly $240, for an annual expense of $364. Total programming time for this app was about 120 hours.CONCLUSIONS: Mobile software is underutilized in the academic surgical arena. The historically large financial barriers to adoption can be overcome by acquisition of coding skills by surgical team members. Direct physician involvement will spawn previously undreamed-of creative applications to enhance practice and education.

View details for DOI 10.1016/j.athoracsur.2019.04.084

View details for PubMedID 31207249
Quality of Operative Performance Feedback Given to Thoracic Surgery Residents Using an App-Based System. Journal of surgical education Karim, A. S., Sternbach, J. M., Bender, E. M., Zwischenberger, J. B., Meyerson, S. L. 2017; 74 (6): e81?e87
Abstract

OBJECTIVE: Residents frequently report inadequate feedback both in quantity and quality. The study evaluates the quality of faculty feedback about operative performance given using an app-based system.DESIGN: Residents requested operative performance evaluation from faculty on a real-time basis using the "Zwisch Me!!" mobile application which allows faculty to provide brief written feedback. Qualitative analysis of feedback was performed using grounded theory.SETTING: The 7 academic medical centers with thoracic surgery training programs.PARTICIPANTS: Volunteer thoracic surgery residents in both integrated and traditional training pathways and their affiliated cardiothoracic faculty.RESULTS: Residents (n = 33) at 7 institutions submitted a total of 596 evaluations to faculty (n = 48). Faculty acknowledged the evaluation request in 476 cases (80%) and in 350 cases (74%) provided written feedback. Initial open coding generated 12 categories of feedback type. We identified 3 overarching themes. The first theme was the tone of the feedback. Encouraging elements were identified in 162 comments (46%) and corrective elements in 230 (65%). The second theme was the topic of the feedback. Surgical technique was the most common category at 148 comments (42.2%) followed by preparation for case (n = 69, 19.7%). The final theme was the specificity of the feedback. Just over half of comments (n = 190, 54.3%) contained specific feedback, which could be applied to future cases. However, 51 comments (14.6%) contained no useful information for the learners.CONCLUSIONS: An app-based system resulted in thoracic surgery residents receiving identifiable feedback in a high proportion of cases. In over half of comments the feedback was specific enough to allow improvement. Feedback was better quality when addressing error prevention and surgical technique but was less useful when addressing communication, flow of the case, and assisting. Faculty development around feedback should focus on making feedback specific and actionable, avoiding case descriptions, or simple platitudes.

View details for PubMedID 29246366
The Effect of Gender on Resident Autonomy in the Operating room. Journal of surgical education Meyerson, S. L., Sternbach, J. M., Zwischenberger, J. B., Bender, E. M. 2017; 74 (6): e111?e118
Abstract

OBJECTIVE: Discrimination against women training in medicine and surgery has been subjectively described for decades. This study objectively documents gender differences in the degree of autonomy given to thoracic surgery trainees in the operating room.DESIGN: Thoracic surgery residents and faculty underwent frame of reference training on the use of the 4-point Zwisch scale to measure operative autonomy. Residents and faculty then submitted evaluations of their perception of autonomy granted for individual operations as well as operative difficulty on a real-time basis using the "Zwisch Me!!" mobile application. Differences in autonomy given to male and female residents were elucidated using chi-square analysis and ordered logistic regression.SETTING: Seven academic medical centers with thoracic surgery training programs.PARTICIPANTS: Volunteer thoracic surgery residents in both integrated and traditional training pathways and their affiliated cardiothoracic faculty.RESULTS: Residents (n = 33, female 18%) submitted a total of 596 evaluations to faculty (n = 48, female 12%). Faculty gave less autonomy to female residents with only 56 of 184 evaluations (30.3%) showing meaningful autonomy (passive help or supervision only) compared to 107 of 292 evaluations (36.7%) at those levels for male residents (p = 0.02). Resident perceptions of autonomy showed even more pronounced differences with female residents receiving only 38 of 197 evaluations (19.3%) with meaningful autonomy compared to 133 of 399 evaluations (33.3%) for male residents (p < 0.001). Potential influencing factors explored included attending gender and specialty, case type and difficulty, and resident level of training. In multivariate analysis, only case difficultly, resident gender, and level of training were significantly related to autonomy granted to residents.CONCLUSIONS: Evaluations of operative autonomy reveal a significant bias against female residents. Faculty education is needed to encourage allowing female residents more operative autonomy.

View details for PubMedID 28669788
Resident Autonomy in the Operating Room: Expectations Versus Reality Meyerson, S. L., Sternbach, J. M., Zwischenberger, J. B., Bender, E. M. ELSEVIER SCIENCE INC. 2017: 1062?68
Abstract

There is concern about graduating thoracic trainees' independent operative skills due to limited autonomy in training. This study compared faculty and trainee expected levels of autonomy with intraoperative measurements of autonomy for common cardiothoracic operations.Participants underwent frame-of-reference training on the 4-point Zwisch scale of operative autonomy (show and tell ? active help ? passive help ? supervision only) and evaluated autonomy in actual cases using the Zwisch Me!! mobile application. A separate "expected autonomy" survey elicited faculty and resident perceptions of how much autonomy a resident should have for six common operations: decortication, wedge resection, thoracoscopic lobectomy, coronary artery bypass grafting, aortic valve replacement, and mitral valve repair.Thirty-three trainees from 7 institutions submitted evaluations of 596 cases over 18 months (March 2015 to September 2016). Thirty attendings subsequently provided their evaluation of 476 of those cases (79.9% response rate). Expected autonomy surveys were completed by 21 attendings and 19 trainees from 5 institutions. The six operations included in the survey constituted 47% (226 of 476) of the cases evaluated. Trainee and attending expectations did not differ significantly for senior trainees. Both groups expected significantly higher levels of autonomy than observed in the operating room for all six types of cases.Although faculty and trainees both expect similar levels of autonomy in the operating room, real-time measurements of autonomy show a gap between expectations and reality. Decreasing this gap will require a concerted effort by both faculty and residents to focus on the development of independent operative skills.

View details for PubMedID 28760467
The University of Minnesota Donor Lung Quality Index: A Consensus-Based Scoring Application Improves Donor Lung Use. Annals of thoracic surgery Loor, G., Radosevich, D. M., Kelly, R. F., Cich, I., Grabowski, T. S., Lyon, C., Michael Morrow, J., Bender, E. M., Billings, J., Hertz, M. 2016; 102 (4): 1156-1165
Abstract

A simplified and consensus-based donor scoring process could improve donor lung use.To develop the University of Minnesota Donor Lung Quality Index (UMN-DLQI), we used expert opinion to create an online survey that ranked 17 lung donor and recipient factors and graded their importance on a scale of 0 to 10. To arrive at consensus-based weights for each of the 17 factors, we used magnitude estimation (ME) methods. We performed receiver operating characteristic (ROC) analyses to evaluate predictive value. An application (app) was developed to simplify the scoring process. A second review process was instituted for every donor offer with an UMN-DLQI score greater than 40 as of September 2014 (post-donor score era).Worldwide, 11 transplantation centers (including ours) completed our survey. Results showed strong consensus among transplantation physicians across disparate practices. UMN-DLQI scores greater than 40 provided a sensitivity of 89%, a specificity of 55%, and a positive predictive value of 52% for donor offer acceptance. Number of transplants (63 versus 48) and donor lung use (15.1% versus 8.9%; p�= 0.02) were significantly better in the post-donor score era without a penalty in transplantation outcomes. There was a trend toward a lower incidence of any primary graft dysfunction within 72 hours (40% versus 75%; p�= 0.06) with a UMN-DLQI greater than 40 but no difference in 30-day or 1-year survival.The UMN-DLQI scoring app is a simple tool for describing the attributes of a donor lung offer. More attention to scores greater than 40 safely improved donor lung use at a single institution.

View details for DOI 10.1016/j.athoracsur.2016.04.044

View details for PubMedID 27492670
Rapid clinical evaluation: an early warning cardiac surgical scoring system for hand-held digital devices EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY Badreldin, A. M., Doerr, F., Bender, E. M., Bayer, O., Brehm, B. R., Wahlers, T., Hekmat, K. 2013; 44 (6): 992-998
Abstract

The purpose of this study was to develop a new scoring system for the prompt recognition of clinical deterioration and early treatment in postoperative cardiac surgical patients.All consecutive adult patients undergoing cardiac surgery between 1st January 2007 and 31st December 2010 were included. The new score was calculated daily until intensive care unit (ICU) discharge. The score consists of 11 variables representing six different organ systems. Performance was assessed using receiver-operating characteristic (ROC) curves and calibration tests.A total of 5207 patients with a mean age of 67.2 � 10.9 years were admitted to the ICU after cardiac surgery. The operations performed covered the whole spectrum of cardiac surgery. ICU mortality was 5.9%. The mean length of ICU stay was 4.6 � 7.0 days. The new score had an excellent discrimination with areas under the ROC curves between 0.91 and 0.96. Calibration was also excellent reflected by observed/expected mortality ratios ranging between 1.0 and 1.26.The new score is a simple and reliable scoring system to assess organ dysfunction in cardiac intensive care patients. It is designed especially for personal digital assistants to simplify and accelerate the process of risk stratification in cardiac surgical ICUs.

View details for DOI 10.1093/ejcts/ezt232

View details for Web of Science ID 000327432200005

View details for PubMedID 23756348
Outcome prediction in cardiac surgery: the first logistic scoring model for cardiac surgical intensive care patients MINERVA ANESTESIOLOGICA Doerr, F., Badreldin, A. M., Bender, E. M., Heldwein, M. B., Lehmann, T., Bayer, O., Brehm, B. B., Ferrari, M., Hekmat, K. 2012; 78 (8): 879-886
Abstract

In the process of risk stratification, a logistic calculation of mortality risk in percentage is easier to interpret. Unfortunately, there is no reliable logistic model available for postoperative intensive care patients. The aim of this study was to present the first logistic model for postoperative mortality risk stratification in cardiac surgical intensive care units. This logistic version is based on our previously presented and established additive model (CASUS) that proved a very high reliability.In this prospective study, data from all adult patients admitted to our ICU after cardiac surgery over a period of three years (2007-2009) were collected. The Log-CASUS was developed by weighting the 10 variables of the additive CASUS and adding the number of postoperative day to the model. Risk of mortality is predicted with a logistic regression equation. Statistical performance of the two scores was assessed using calibration (observed/expected mortality ratio), discrimination (area under the receiver operating characteristic curve), and overall correct classification analyses. The outcome measure was ICU mortality.A total of 4054 adult cardiac surgical patients was admitted to the ICU after cardiac surgery during the study period. The ICU mortality rate was 5.8%. The discriminatory power was very high for both additive (0.865-0.966) and logistic (0.874-0.963) models. The logistic model calibrated well from the first until the 13th postoperative day (0.997-1.002), but the additive model over- or underestimated mortality risk (0.626-1.193).The logistic model shows statistical superiority. Because of the precise weighing the individual risk factors, it offers a reliable risk prediction. It is easier to interpret and to facilitate the integration of mortality risk stratification into the daily management more than the additive one.

View details for Web of Science ID 000309080200004

View details for PubMedID 22475805
CONTRAST ECHOCARDIOGRAPHY - A METHOD TO VISUALIZE CHANGES IN REGIONAL MYOCARDIAL PERFUSION IN THE DOG-MODEL FOR CABG SURGERY ANESTHESIOLOGY ARONSON, S., Bender, E., Feinstein, S. B., HEIDENREICH, P. H., Ellis, J., Dick, C., Roizen, M. F., Karp, R. B. 1990; 72 (2): 295-301
Abstract

The ability of contrast echocardiography to assess regional myocardial perfusion during cardiopulmonary bypass in a dog model for coronary artery bypass surgery was evaluated. Sonicated Renograffin-76 microbubbles (meglumin diatrigoate and sodium diatrigoate) were injected into an aortic root proximal to an aortic occlusion clamp root while dogs were on cardiopulmonary bypass, with the heart arrested in diastole. Echocardiographic contrast-enhanced regions of myocardial perfusion were easily visualized. Differences in contrast-enhanced myocardial regions depended on coronary artery occlusion or patency. The contrast-enhanced images of myocardial perfusion showed that, for a given myocardial segment of the supplying vessel, the presence or absence of contrast effect reliably predicted vessel occlusion or patency (P less than .01). In the future contrast echocardiography may allow the direct assessment of regional myocardial perfusion in the operating room.

View details for Web of Science ID A1990CL65000015

View details for PubMedID 2301760
ESOPHAGOGASTRECTOMY FOR BENIGN ESOPHAGEAL STRICTURE - FATE OF THE ESOPHAGOGASTRIC ANASTOMOSIS ANNALS OF SURGERY Bender, E. M., WALBAUM, P. R. 1987; 205 (4): 385-388
Abstract

Eighty-nine patients who had resection of benign esophageal stricture with esophagogastrostomy were reviewed through medical records and by mailed questionnaire. The 30-day mortality rate was 8.9%. Seventy-six patients were available for follow-up for an average of 66.4 months (Group 1). Forty-three of these patients were followed up for longer than 5 years (Group 2). The incidence of postoperative heartburn in Groups 1 and 2 was 7.9% and 7.0%, respectively. The incidence of postoperative dysphagia in Groups 1 and 2 was 39.4% and 30.2%, respectively, with most episodes occurring within 2 years of operation. The vast majority of these patients required multiple esophageal dilatations over a long time. The high rate of restricture precludes support for the routine use of an esophagogastric anastomosis after resection of benign esophageal stricture.

View details for Web of Science ID A1987G695700007

View details for PubMedID 3566374
PREVENTION OF ALTERATIONS IN POSTOPERATIVE LYMPHOCYTE SUBPOPULATIONS BY CIMETIDINE AND IBUPROFEN AMERICAN JOURNAL OF SURGERY Hansbrough, J. F., ZAPATASIRVENT, R. L., Bender, E. M. 1986; 151 (2): 249-255
Abstract

Surgical procedures probably result in a temporary state of immunosuppression. Identification of functional lymphocyte subclasses using appropriate monoclonal antibodies appears to serve as a sensitive, accurate, and reproducible measure of immune status in patients in many disease states. Using monoclonal antibodies specific for lymphocyte surface markers and immunofluorescent assay, we quantitated lymphocyte subpopulations in patients undergoing surgical procedures. Cholecystectomy, colon surgery, and coronary bypass procedures all resulted in postoperative decreases in helper and inducer populations and increases in cytotoxic suppressor populations, with resultant depressions in the helper to suppressor lymphocyte ratio. Studies in an additional group of patients who underwent cholecystectomy demonstrated that these changes could be prevented by perioperative administration of ibuprofen and cimetidine. These results suggest that prostaglandins and histamines are involved in immunoregulatory events after major operation. The ability of specific pharmacologic therapy to prevent alterations in lymphocyte populations suggest that postoperative immunity may be preserved, hopefully leading to greater host resistance against infection and tumor dissemination.

View details for Web of Science ID A1986A254100014

View details for PubMedID 3484914
POSTBURN IMMUNOSUPPRESSION IN AN ANIMAL-MODEL .4. IMPROVED RESISTANCE TO SEPTIC CHALLENGE WITH IMMUNOMODULATING DRUGS SURGERY ZAPATASIRVENT, R. L., Hansbrough, J. F., Bender, E. M., BARTLE, E. J., Mansour, M. A., Carter, W. H. 1986; 99 (1): 53-59
Abstract

We have previously demonstrated that certain pharmacologic agents administered to burned mice will restore cell-mediated immunity, as evidenced by measurement of delayed hypersensitivity responses and determination of splenic helper/suppressor lymphocyte ratios. These drugs are systemic cimetidine, ibuprofen, cyclophosphamide, and topical cerium nitrate. In the studies reported here we performed cecal ligation and puncture (CLP) in burned mice as a measure of resistance to infectious challenge. Survival after CLP with a 23-gauge needle used for puncture was markedly decreased when performed on the tenth postburn day (normal 63.7%, 10 days postburn 20.0%; p less than 0.001), but survival was not decreased when CLP was performed on the fifth (60.0%; p not significant) or twenty-first postburn day (65.3%; p not significant). Animals were then treated with the four agents in carefully defined dosage regimens, and survival was again determined on the tenth postburn day. Survival figures with p values compared to burned, untreated animals: burn plus cimetidine 62.2%, p less than 0.0005; burn plus: ibuprofen 64.7% p less than 0.0003; burn plus cyclophosphamide 68.2%, p less than 0.0001; burn plus cerium nitrate 54.1%, p less than 0.004. Specific pharmacologic therapy in burned mice in dosage regimens that have been shown to improve cell-mediated immunity is also able to significantly improve resistance to subsequent infectious challenge.

View details for Web of Science ID A1986AYB7300008

View details for PubMedID 2934837
Modulation of suppressor cell activity and improved resistance to infection in the burned mouse. journal of burn care & rehabilitation Hansbrough, J. F., Zapata-Sirvent, R. L., Peterson, V., Bender, E. M., Claman, H. N. 1985; 6 (3): 270-274
View details for PubMedID 2954966
RESTORATION OF IMMUNITY IN BURNED MICE BY CIMETIDINE JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE Bender, E. M., Hansbrough, J. F., ZAPATASIRVENT, R., Sullivan, J., Claman, H. N. 1985; 25 (2): 131-137
Abstract

We have previously described a mouse model of postburn suppression of cell-mediated immunity (CMI). Ear swelling (ES) in response to contact antigen challenge is depressed maximally 14 days following a 25% steam burn and recovers to control levels 3 weeks postburn. Splenic lymphocyte proliferation in response to Concanavalin A (Con A) is also depressed 14 days postburn. Splenic T-lymphocyte subset analysis with monoclonal antibodies for helper cells (Lyt 1.2) and suppressor cells (Lyt 2.2) reveals that T-helper cells reach a minimal level and T suppressor cells reach a maximum level 14 days postburn. The helper: suppressor ratio (HSR) reaches its nadir at day 14. Treatment of burned mice with low-dose cimetidine (2 or 10 mg/kg/day), but not high-dose (50 mg/kg/day), for 14 days restores CMI. Low-dose cimetidine also normalizes the HSR but does not effect postburn depression of mitogen responsiveness. Low-dose cimetidine probably restores CMI by inhibiting suppressor cells, whereas high doses provide more global inhibition. Recovery of mitogen responsiveness may require continued cimetidine presence in culture.

View details for Web of Science ID A1985ACH9200008

View details for PubMedID 3156251
PREVENTION OF SUPPRESSED CELL-MEDIATED-IMMUNITY IN BURNED MICE WITH HISTAMINE-2 RECEPTOR ANTAGONIST DRUGS JOURNAL OF SURGICAL RESEARCH Hansbrough, J. F., ZAPATASIRVENT, R., Bender, E. M., Peterson, V. 1985; 39 (2): 150-156
Abstract

Thermal injury has been shown to suppress many aspects of both specific and nonspecific immune responses. We investigated the effect of two histamine H-2 antagonist drugs on cell-mediated immunity in burned mice, utilizing a method of quantitating the degree of contact sensitivity elicited to the antigen. 2,4-dinitrofluorobenzene (DNFB). Following sensitization by painting the abdomen with DNFB, animals were challenged 5 days later by painting the ears; subsequent ear swelling is a sensitive and reproducible measure of cell-mediated immunity. We have previously demonstrated that burned mice are maximally immunosuppressed 10 to 14 days following burn injury. In the present study we found that daily intraperitoneal administration of appropriate doses of the H-2 antagonists cimetidine (2 and 10 mg/kg/day) and ranitidine (2 and 10 mg/kg/day) resulted in maintenance of normal cell-mediated immunity in burned animals. Neither a lower dose of ranitidine (0.2 mg/kg/day) nor higher doses of cimetidine (20 and 50 mg/kg/day) restored immunity, and diphenhydramine, an H-1 antagonist, had no effect. There was no augmentation of contact sensitivity in unburned mice treated with cimetidine. The immunorestorative effect is probably secondary to antagonism of histamine H-2 receptors on suppressor T lymphocytes, and may reflect increased suppressor cell activity in burned mice; however, other mechanisms may be involved.

View details for Web of Science ID A1985AND7100007

View details for PubMedID 4021474
THE EFFECT OF HISTAMINE-RECEPTOR ANTAGONISTS ON SPECIFIC AND NONSPECIFIC SUPPRESSION OF EXPERIMENTAL CONTACT SENSITIVITY JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Mekori, Y. A., Bender, E. M., ZAPATASIRVENT, R., Hansbrough, J. F., Claman, H. N. 1985; 76 (1): 90-96
Abstract

We studied the effects of H1 and H2 histamine receptor antagonists on down regulation of contact sensitivity (CS) to dinitrofluorobenzene (DNFB). Two H2 receptor antagonists, cimetidine and ranitidine, reversed the nonspecific immunosuppression of CS induced by burns. On the other hand, these two drugs did not affect the antigen-specific suppressor T cell-mediated tolerance to DNFB induced by dinitrobenzene sulfonic acid. Two H1 antagonists did not affect the down regulation of CS induced by either tolerance or burning. The differential sensitivities to histamine 2-receptor antagonists indicate that the mechanisms for nonspecific burn-induced immunosuppression are different from those for hapten-specific tolerance to DNFB.

View details for Web of Science ID A1985AMV8400012

View details for PubMedID 3159783
CHARACTERIZATION OF THE IMMUNOSUPPRESSIVE EFFECT OF BURNED TISSUE IN AN ANIMAL-MODEL JOURNAL OF SURGICAL RESEARCH Hansbrough, J. F., ZAPATASIRVENT, R., Peterson, V., Wang, X., Bender, E., Claman, H., BOSWICK, J. 1984; 37 (5): 383-393
Abstract

The immunosuppressive effect of burned tissue was studied using a mouse burn model. To evaluate the immunologic status an in vivo measure of cell-mediated immunity (CMI) involving contact sensitization of mice by painting the skin with dinitrofluorobenzene was used; mice were challenged 5 days later by painting the ear with the same antigen. Ear swelling in response to antigenic challenge was used as a quantitative measure of CMI; diminution in ear swelling in treatment mice compared to sensitized, unburned control mice indicated the degree of immunosuppression. A full-thickness steam burn covering 20% body surface ares (BSA) was profoundly immunosuppressive as reflected by ear swelling of 45 to 60% of that found in normal mice; partial thickness burns and burns of 10% BSA extent were not significantly immunosuppressive. Transfer into unburned mice of burned skin equivalent in size to a 20% BSA burn eschar resulted in marked immunosuppression, but transfer of smaller amounts of burned skin, or of larger amounts of unburned skin and normal and burned liver tissue, did not produce immunosuppression. Mice receiving a very high-temperature (300 degrees C), dry burn were only slightly more suppressed than mice receiving a standard steam burn. Normal immunity was preserved in burned mice which received daily application of cerium nitrate to the wound for 7 days, but application of other topical agents commonly used in burn treatment did not preserve immunity. Postburn immunosuppression thus appears related quantitatively to toxic factors in burned skin, and these toxic factors can be abrogated in burned mice by the topical application of cerium nitrate.

View details for Web of Science ID A1984TS32800007

View details for PubMedID 6492780
CONSERVATIVE MANAGEMENT OF SAND ASPIRATION - CASE-REPORT MILITARY MEDICINE Bender, E. M., Kashuk, J. L., Moore, E. E., HOPEMAN, A. R. 1984; 149 (2): 98-99
View details for Web of Science ID A1984SD03500013

View details for PubMedID 6427668
ALTERED HELPER AND SUPPRESSOR LYMPHOCYTE POPULATIONS IN SURGICAL PATIENTS - A MEASURE OF POSTOPERATIVE IMMUNOSUPPRESSION AMERICAN JOURNAL OF SURGERY Hansbrough, J. F., Bender, E. M., ZAPATASIRVENT, R., Anderson, J. 1984; 148 (3): 303-307
Abstract

Although a wealth of evidence has suggested that cell-mediated immunity is suppressed after simple surgical trauma, there have been contradictory results using stimulation assays of lymphocyte function. We quantitated T-lymphocyte subsets in 11 patients undergoing routine cholecystectomy by immunofluorescence microscopy using specific monoclonal antibodies. T-helper to T-suppressor cell ratios were calculated on the preoperative day and the first postoperative day in all patients, and on the third or fourth postoperative day in five patients. Helper to suppressor ratios decreased in all patients on the first postoperative day (p greater than 0.01), but returned to within normal limits on subsequent days. Changes were due more to decreases in helper cells than to increases in suppressor cells, although changes in both populations were statistically significant. The measurement of T-cell subsets by antibody-specific labeling and immunofluorescence microscopy may prove to be a more sensitive, quantifiable, and reproducible assay of immune function in surgical or traumatized patients than use of stimulation assays. Measurements of specific helper and suppressor lymphocyte populations may prove useful in predicting morbidity and mortality, and may also help in studying the effect of immunomodulating agents on the immune response.

View details for Web of Science ID A1984TG87600003

View details for PubMedID 6236703
Prevention of post-burn alterations in helper and suppressor T-lymphocytes by cimetidine The Heart Surgery Forum Bender, E., Hansbrough, J., Whitefield, J., Anderson, J., Claman, H. 1984; 35: 166
STEROIDOGENIC EFFECT OF 17 BETA-ESTRADIOL IN RABBIT - STIMULATION OF PROGESTERONE SYNTHESIS IN PREMATURELY REGRESSING CORPORA-LUTEA ENDOCRINOLOGY Bender, E. M., MILLER, J. B., Possley, R. M., Keyes, P. L. 1978; 103 (5): 1937-1943
View details for Web of Science ID A1978FV57600055

View details for PubMedID 748025
SERUM PROGESTERONE IN PREGNANT RATS WITH ECTOPIC OR INSITU CORPORA-LUTEA - CORRELATION BETWEEN AMOUNT OF LUTEAL TISSUE AND PROGESTERONE CONCENTRATION BIOLOGY OF REPRODUCTION ELBAUM, D. J., Bender, E. M., Brown, J. M., Keyes, P. L. 1975; 13 (5): 541-545
View details for Web of Science ID A1975BA39600008

View details for PubMedID 1203409

Edward Bender

Clinical Professor, Cardiothoracic Surgery

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