The fundamentals of laparoscopic surgery in general surgery residency: fundamental for junior residents' self-efficacy

BACKGROUND

Implementation of the Fundamentals of Laparoscopic Surgery (FLS) by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) has served a need for educational structure for laparoscopic skill within General Surgery training since 2004. This study looks at how FLS affects resident self-efficacy (SE) with laparoscopic procedures.

METHODS

We conducted a national survey, linked to the 2020 American Board of Surgery In-Training Examination (ABSITE), in which 9275 residents from 325 US General Surgery Training Programs participated. The online survey included multimodal questions that analyzed whether participants felt they could perform the most commonly-logged laparoscopic operations among residents [Laparoscopic Appendectomy (LA), Laparoscopic Cholecystectomy (LC), Laparoscopic Right Hemicolectomy (LRH), Diagnostic Laparoscopy (DL)] without faculty assistance. This used a 5-point scaled assessment, ranging from "not able to" to "definitely able to." Multivariate analyses determined if completion of FLS made a difference for resident self-efficacy, stratified by post-graduate year (PGY).

RESULTS

At the time of the survey, 2300 reported completion of FLS. The percentage of FLS completion increased from PGY1 to PGY5 (4.2% n = 59 vs 85.8% n = 893). PGY1 residents who completed FLS, from 48 diverse institutions, demonstrated the most significant increases in SE (p < 0.05) with significantly higher perceived self-efficacy in LA (p = 0.001) and LRH (p = 0.012). PGY2 and PGY3 residents indicated increased SE in DL (p = 0.037, p = 0.015, respectively), based on FLS completion. These FLS effects were less evident in the more senior classes.

CONCLUSIONS

Completion of FLS arguably has the greatest benefits for more junior residents, as it establishes a foundation of laparoscopic knowledge and skill, upon which further residency training can build. Successful completion of the curriculum and assessment offered by the Fundamentals of Laparoscopic Surgery leads to greater sense of ability in early trainees.

Surgical endoscopy education research: how are we doing?

BACKGROUND

Surgical endoscopy (SE), the official journal of the Society of American Gastrointestinal and Endoscopic Surgeons and the European Association for Endoscopic Surgery, is an important source of new evidence pertaining to surgical education in the field. However, qualitative deficiencies in medical education research have prompted medical education leaders to advocate for increased methodological rigor. The purpose of this study is to review the quality of education-focused research published through SE.

METHODS

A PubMed search examining all SE articles categorized as education-related research from 2010 to 2019 was conducted; studies not meeting inclusion criteria were excluded. Remaining publications were independently reviewed, classified, and scored by 7 raters using the medical education research study quality instrument (MERSQI). Intraclass correlation was calculated and data were examined with descriptive statistics.

RESULTS

A total of 227 studies met inclusion criteria. There was no significant difference in number of publications by year (average 25.88 [SD 5.6]); 60% were conducted outside of the United States, and 47% (n = 106) were funded. The average MERSQI was 12.5 (SD 2). Most studies used two-group non-random (42%, n = 96) or post/cross-sectional designs (29%, n = 65). Thirty-six (16%) were randomized controlled trials. Multi-institutional studies comprised 24% (n = 54). Of the manuscripts, 96% (n = 217) reported at least one measure of validity evidence and 28% (n = 67) described three levels of validity evidence. Studies primarily reported changes in skills or knowledge (45%, n = 103) or satisfaction or general facts (44%, n = 99), while patient-related outcomes encompassed 3% (n = 6) of studies. ICC between raters was 0.93 (CI 0.90-0.93, p < 0.001).

CONCLUSIONS

Based on publications to date, this journal's peer review process appears to facilitate the dissemination of education-related studies of moderate to good quality. However, there were uncovered deficits, ranging from validity evidence to study designs and level of outcomes. This journal's breadth of viewership offers a potential venue to advance education-related research.

Outcomes From a Level 1 Trauma and Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Center of Excellence

Trauma patients with obesity experience disparity in various outcomes. Similar to trauma centers, vetted credentialing is in practice for bariatric services. This study evaluates outcomes of trauma patients with obesity at a Level 1 Trauma Center and verified bariatric surgery center of excellence (BSCOE). The trauma registry was reviewed for individuals admitted between January 1, 2008 to December 31, 2020 who were age 19 years or older and stratified by World Health Organization body mass index (BMI). Various morbidity and mortality outcomes were examined. There were 20 788 patients included in this analysis. Intensive care unit (ICU) length of stay (LOS) was found to be statistically longer for patients with BMI >40. Overall results suggest that the infrastructure associated with this BSCOE may improve care for this specialized patient population.

Diversity, Equity, and Inclusion: A Current Analysis of General Surgery Residency Programs

BACKGROUND

Local, regional, and national diversity, equity, and inclusion (DEI) initiatives have been established to combat barriers to entry and promote retention in surgery residency programs. Our study evaluates changes in diversity in general surgery residency programs. We hypothesize that diversity trends have remained stable nationally and regionally.

MATERIALS AND METHODS

General surgery residents in all postgraduate years were queried regarding their self-reported sex, race, and ethnicity following the 2020 ABSITE. Residents were then grouped into geographic regions. Data were analyzed utilizing descriptive statistics, Kruskal-Wallis test, and chi-square analyses.

RESULTS

A total of 9276 residents responded. Nationally, increases in female residents were noted from 38.0 to 46.0% (P < .001) and in Hispanic or Latinx residents from 7.3 to 8.3% (P = .031). Across geographic regions, a significant increase in female residents was noted in the Northwest (51.9 to 58.3%, P = .039), Midwest (36.9 to 43.3%, P = .006), and Southwest (35.8 to 47.5%, P = .027). A significant increase in black residents was only noted in the Northwest (0 to 15.8%, P = .031). The proportion of white residents decreased nationally by 8.9% and in the Mid-Atlantic, Southeast, and Southwest between 5.5 and 15.9% (P < .05).

DISCUSSION

In an increasingly diverse society, expanding the numbers of underrepresented surgeons in training, and ultimately in practice, is a necessity. This study shows that there are region-specific increases in diversity, despite minimal change on a national level. This finding may suggest the need for region-specific DEI strategies and initiatives. Future studies will seek to evaluate individual programs with DEI plans and determine if there is a correlation to changing demographics.

The Utility of Peers and Trained Raters in Technical Skill-based Assessments a Generalizability Theory Study

OBJECTIVE

The gold standard for evaluation of resident procedural competence is that of validated assessments from faculty surgeons. A provision of adequate trainee assessments is challenged by a shortage of faculty due to increased clinical and administrative responsibilities. We hypothesized that with a well constructed assessment instrument and training, there would be minimal differences in procedural assessments made by near-peer resident raters (RR), faculty raters (FR), and trained raters (TR).

DESIGN

Deidentified videos of residents performing hand-sewn (HA) and stapled (SA) anastomoses were distributed to blinded reviewers of 3 types. Intra-class correlation (ICC) of RR, FR and TR assessments was determined for each procedure. A fully-crossed design was used to examine the internal structure validity in a generalizability study. A Decision study was performed to make projections on the number of raters needed for a g-coefficient > 0.70.

SETTING

This study was conducted within a private academic institution, using the creation of intestinal anastomoses as the procedural model.

PARTICIPANTS

Raters consisted of residents who were untrained to the assessment (UTA) tool, UTA faculty surgeons, and individuals with training.

RESULTS

Twenty nine videos were reviewed (15 HA and 14 SA) by a total of 9 video reviewers (4 RR, 2 FR, and 3 TR). HA ICC values were 0.84 (Confidence Interval [CI]:0.81-0.87) for RR, 0.89 (CI:0.86-0.92) for FR, and 0.88 (CI:0.86-0.90) for TR. SA ICC values were 0.77 (CI:0.72-0.80) for RR, 0.79 (CI:0.75-0.83) for FR, and 0.86 (CI:0.83-0.88) for TR. The g-coefficient was RR = 0.72, FR = 0.85, and TR = 0.77 for HA; and RR = 0.33, FR = 0.38, and TR = 0.4 for SA. The D-study indicated that at least 2 raters of any type were needed for HA and > 11 FR for SA.

CONCLUSIONS

Faculty without training have high assessment agreement. Peers for surgical skills assessment is an option for formative evaluation without training. Training to assessment tools should be performed for any assessment, formative or summative, for the optimal evaluation of procedural competence.

American Board of Surgery Entrustable Professional Activities (EPAs): Assessing Graduating Residents' Perception of Preoperative Entrustment

OBJECTIVE

To determine if graduating surgical residents are achieving entrustment of surgical entrustable professional activities (EPAs). We hypothesize that postgraduate year 5 (PGY5) residents are achieving evaluation and management entrustment in the selected EPAs.

DESIGN

In January 2020, surgical residents completed a survey following the American Board of Surgery In-Training Examination (ABSITE) to measure their levels of entrustment in 4 of the 5 ABS-selected EPAs. A Resident Entrustability Index (REI) score was developed to ascertain PGY5 residents' levels of entrustment (range 1-5). Residents indicated how often their assessments and operative plans were modified in the prior 6 months for each EPA (1=Always, 2=Frequently, 3=Occasionally, 4=Rarely, 5=Never). An independent clinical decision-making score (ICDM) was developed with subsequent evaluation of its relationships to intrinsic, resident-related and extrinsic, program-dependent factors.

SETTING

A national post-ABSITE survey.

PARTICIPANTS

All general surgery residents participating in ABSITE were invited to participate. Of the 1367 PGY5 residents that completed the survey, 1049 residents (76.7%) responded to the surgical EPA items.

RESULTS

Residents achieved an average REI of 4, indicating rare modification of assessments and operative plans for the 4 EPAs assessed. Complete entrustment was reported for inguinal hernias and penetrating abdominal trauma (Median REI = 5, IQR 4, 5) indicating assessments and operative plans were never modified. Lack of entrustment (REI ≤3) was reported by a minority of residents (ranging from 8.6% for operative plan of right lower quadrant pathology to 12.8% for operative plan of blunt abdominal trauma). Significant resident-related and program-dependent factors associated with achievement of expected ICDM was socializing with a co-resident (p = 0.001), while training in one's hometown (p < 0.001) and policies that mandate attendings be scrubbed in (p = 0.022) were associated with decreased achievement of expected ICDM. Overall, 89.2% and 90.3% of PGY5 residents are attaining appropriate levels of entrustment and ICDM abilities, respectively, within 6 months of graduating.

CONCLUSIONS

Of the EPAs evaluated, PGY5 residents are achieving appropriate levels of entrustment in evaluation and management. Although this is the case for a vast majority of PGY5 residents, there is still work to be done to ensure that all PGY5 residents are attaining entrustment prior to graduation. Our study also provides content validity for the surgical EPAs in assessing levels of entrustment in PGY5 residents.

Isolating steps instead of learners: Use of deliberate practice and validity evidence in coronavirus disease (COVID)-era procedural assessment

Background

In surgical training, assessment tools based on strong validity evidence allow for standardized evaluation despite changing external circumstances. At a large academic institution, surgical interns undergo a multimodal curriculum for central line placement that uses a 31-item binary assessment at the start of each academic year. This study evaluated this practice within increased in-person learning restrictions. We hypothesized that external constraints would not affect resident performance nor assessment due to a robust curriculum and assessment checklist.

Methods

From 2018 to 2020, 81 residents completed central line training and assessment. In 2020, this curriculum was modified to conform to in-person restrictions and social distancing guidelines. Resident score reports were analyzed using multivariate analyses to compare performance, objective scoring parameters, and subjective assessments among “precoronavirus disease” years (2018 and 2019) and 2020.

Results

There were no significant differences in average scores or objective pass rates over 3 years. Significant differences between 2020 and precoronavirus disease years occurred in subjective pass rates and in first-time success for 4 checklist items: patient positioning, draping, sterile ultrasound probe cover placement, and needle positioning before venipuncture.

Conclusion

Modifications to procedural training within current restrictions did not adversely affect residents’ overall performance. However, our data suggest that in 2020, expert trainers may not have ensured learner acquisition of automated procedural steps. Additionally, although 2020 raters could have been influenced by logistical barriers leading to more lenient grading, the assessment tool ensured training and assessment integrity.

A Novel Blended Curriculum for Communication of Informed Consent With Surgical Interns

BACKGROUND

Interns often conduct procedural informed consent discussions (ICDs), identified as a core entrustable professional activity. Deficiencies in the training process for ICDs span across specialties.

OBJECTIVE

We provide evidence for a curriculum and assessment designed to standardize the training process and ensure ICD competency in surgical interns.

METHODS

In March 2019, PowerPoint educational materials were emailed to one academic institution's new surgical interns, who in June participated in an onsite 1-hour role-play "hot seat" group activity (GA) with an untrained simulated patient, and in October completed a single trained simulated patient (real-time raters) verification of proficiency (VOP) assessment. Curriculum evaluation was measured through intern pre-/post-confidence (5-point scale), and the VOP's Cronbach's alpha and test-retest were examined. Data were analyzed with descriptive statistics, paired t tests, and 2-way random effects models.

RESULTS

Of 44 new interns, 40 (91%) participated in the remote teaching and live GA and were assessed by the VOP. Pre-/post-GA confidence increased a mean difference of 1.3 (SD = 0.63, P < .001). The VOP's Cronbach's alpha was 0.88 and test-retest was 0.84 (95% CI 0.67-0.93, P < .001), with a 95% pass rate. The 2 first-time fail students required remediation. Time commitment included 1 hour maximum for individual training and implementation and 30 minutes for assessment. The use of volunteers and donated space mitigated additional costs.

CONCLUSIONS

Remote asynchronous and group skills teaching for new general surgical interns improved their confidence in conducting procedural ICDs. A patient-simulation verification process appeared feasible with preliminary evidence of retest and internal consistency.

A Generalizable Multimodal Scrub Training Curriculum in Surgical Sterile Technique

INTRODUCTION

Recent endeavors from governing bodies such as the AAMC have formally recognized the importance of aseptic technique. AAMC guidelines include activities that all graduating physicians should be able to perform with minimum indirect supervision and were developed to recognize these needs. For example, the skills necessary for aseptic technique include daily safety habits and general physician procedures.

METHODS

We developed a scrub training curriculum and evaluated the program through a quasi-experimental study with a pre- and posttest design. Questions were developed to examine students' perceived knowledge and skills as related to the objectives of the course and to their anxieties, concerns, and future training needs.

RESULTS

Between February 2020 and March 2020, 44 students completed the curriculum. Students indicated that self-efficacy significantly increased in all aspects of the curricular goals following curriculum completion. Students identified understanding OR etiquette as the most anxiety-provoking element associated with scrub training. They felt that more time could be spent elucidating this etiquette. On the other hand, tasks such as surgical hand hygiene were the least anxiety-inducing.

DISCUSSION

We share this multimodal scrub training curriculum, mapped to the AAMC's guidelines, to reduce variability in teaching strategies and skills acquisition through a standardized curriculum. Also, we effectively imparted these skills and instilled a sense of confidence in learners as they worked to provide their best in patient care and safety.

Defining the Deficit in US Surgical Training: The Trainee's Perspective

BACKGROUND

Self-efficacy is the personal judgment of how well one can successfully complete a task. The goal of this study was to assess self-efficacy of PGY5 residents for common general surgery operations. We hypothesized there are deficits in self-efficacy of PGY5 residents, and self-efficacy of a given operation correlates with experience performing the operation without attending assistance (independently) and teaching the operation from start to finish.

METHODS

A survey was linked to the 2020 American Board of Surgery In-Training Examination. From the ACGME case log's 15 most commonly performed surgeon-chief operations and AHRQ's 15 most common operations, 10 operations were selected. Residents evaluated their ability to perform these operations independently using a 5-point self-efficacy scale. Residents were asked whether they had experience performing these operations independently or teaching the operation from start to finish. Descriptive statistics and Pearson correlation were used to examine the relationship between self-efficacy and operative experience.

RESULTS

In all, 1,145 of 1,367 PGY5 residents (84%) responded. Highest self-efficacy was in performing wide-local excision (90.24%) and lowest was in performing open thyroidectomy (19.58%). Eighty-eight (7.7%) reported self-efficacy in all procedures. Statistically significant positive correlations were identified between experience and self-efficacy for cases performed without assistance (r = 0.98, p < 0.01) and cases taught (r = 0.91, p < 0.01).

CONCLUSIONS

With 5 months left in training, 92.3% of residents report deficits in preparation for practice, as defined by self-efficacy to complete common procedures independently. Resident self-efficacy increased in direct relation to performed cases and cases taught.

Why the Lab? What is Really Motivating General Surgery Residents to Take Time for Dedicated Research

OBJECTIVE

Over one third of general surgery residents interrupt their clinical training to pursue dedicated research time (DRT), which has financial implications for programs and residents. Studies have examined the impact of DRT on academic outcomes, but little is known about why residents pursue DRT. Therefore, this study aimed to examine resident motivations regarding DRT in order to gain an understanding of resident goals and challenges surrounding this phase of training.

DESIGN

Surgical residents currently participating in DRT and residents considering completing DRT were recruited to participate. Members of the research team at each institution conducted interviews and focus groups, which were recorded and transcribed. Data was analyzed using the qualitative method of open and focused coding. Identified themes guided the development of a conceptual framework.

SETTING

Interviews and focus groups were held at three geographically diverse US academic health centers.

PARTICIPANTS

Twenty-one surgery residents participated.

RESULTS

Reasons for pursuing DRT fell into 1 of 3 themes: strategic career planning, professional development, and personal rejuvenation. Residents described the perceived need for publications or networking to enhance future competitiveness for desired fellowships or academic appointments. Residents also expressed the desire to have time for career exploration and to cultivate mentorship for their professional career. The need to take time off for more personal reasons, including burnout, was pervasive. Additionally, many in DRT felt under-supported in developing their research skills and expressed a desire for more formal instruction and guidance from mentors.

CONCLUSIONS

General surgery residents' motivations to pursue DRT are multifactorial. Professional development is a pervasive motivation and includes learning skills that can be applied to future research. Current DRT programs may be inadequate in supporting residents to achieve this goal. These results can be used to inform programmatic efforts to optimize DRT for residents and mentors alike.

Preclinical Surgical Preparatory Course and the NRMP Match: Early Exposure and Surgical Recruitment a 10-Year Follow-Up

OBJECTIVE

Many medical students mentally commit to specialties prior to entering clerkships. This is why early preclinical interactions with surgical specialties, through mentorship and/or interest groups, increases the opportunity to nurture enthusiasm for surgery. In 2007, a course providing preclinical medical students with introductory surgical skills training and preparation for the surgical environment ("SURG205") was established at our institution. The course underwent a major revision in 2016, increasing intraoperative mentorship by matching students to surgical attendings and requiring students to scrub into operative cases together. We anticipate that the positive surgical experiences created by the course will lead to further development and enhancement of student interest in surgical specialties-interest that we hypothesized would reflect in their National Resident Matching Program (NRMP) Match outcomes.

DESIGN

NRMP results from 2010 to 2019 were cross-referenced with a database of students who participated in the SURG205 course from 2007 to 2016. With this, we examined the correlation between student participation in SURG205 and surgical specialty match. Descriptive statistics were used to review the trends of the NRMP results, and Pearson's correlation was used to determine the relationship and its significance.

SETTING

This study was conducted in a single private medical school in California.

PARTICIPANTS

Specialties considered "surgical" included: General Surgery, integrated programs-such as Plastic, Thoracic, or Vascular surgery, Obstetrics and Gynecology, Orthopedic Surgery, Otolaryngology, Neurosurgery, and Urology. All other specialties were considered nonsurgical. Students identified as having participated in SURG205 and who then also took part in the NRMP.

RESULTS

Seven hundred eighty students underwent the Match process from 2010 to 2019. 144 (18.5%) of these students participated in SURG205 between 2007 and 2016. Each Match class ranged in size from 62 to 91 (median = 77.5, IQR = 14.5) students. (Table 1) Two-hundred and nineteen students (28.1%) matched into a surgical specialty, of which 34 (15.5%) selected general surgery. From 2010 to 2019 the rate of students who matched into surgical specialties averaged 28.1% per year with a slight nonstatistically significantly increasing trend over that time period R² = 0.30 (p = 0.09; Fig. 1). There was a significant increase in trend in proportion of students who took the course and matched into any specialty between 2010 and 2019 (R² = 0.85, p = 0.0002; Fig. 2). And, there was a statistically significant positive relationship between students taking the course and matching into a surgical specialty (R² = 0.63, p = 0.01; Fig. 3).

CONCLUSION

Our results highlight the increasing tendency of students who pursue surgical specialties having previously participated in this early exposure courses. Not only is student interest created and encouraged through positive mentorship experiences, but that interest may be associated with increases in application rates and eventual match into the specialty. General surgery training programs might consider these trends when designing courses to ease transitions into first-year residency positions-such as fourth-year surgical boot camps, surgical procedure-based anatomy courses, and mentorship frameworks. This information further justifies the cost and time commitment required to administer these programs for students.

Implementation and Evaluation of an Educational Program for Increasing Diversity and Inclusion in Surgery for Preclinical Students

This survey study assesses the student-led Service Through Surgery model for increasing diversity and inclusion in surgical education.

Medical Student Values Inform Career Plans in Service & Surgery-A Qualitative Focus Group Analysis

BACKGROUND

Diversifying the surgical workforce is a critical component of improving care for underserved patients. To recruit surgeons from diverse backgrounds, we must understand how medical students choose their specialty. We investigate how preclinical students contemplate entering a surgical field.

MATERIALS AND METHODS

We conducted semistructured focus groups during two iterations of a seminar class called Service Through Surgery. Discussion goals included identifying student values and assessing how they inform early career decisions. We used a systematic, collaborative, and iterative process for transcript analysis, including developing a codebook, assessing inter-rater reliability, and analyzing themes.

RESULTS

Twenty-four preclinical medical students from diverse backgrounds participated in seven focus groups; most were women (16; 67%), in their first year of medical school (19; 79%), and interested in surgery (17; 71%). Participants ranked professional fulfillment, spending time with family, and serving their communities and/or underserved populations among their most important values and agreed that conducting groundbreaking research, working long hours, and finding time for leisure activities were the least important. We constructed a framework to describe student responses surrounding their diverse visions for service in future surgical careers through individual doctoring interactions, roles in academia, and broader public service.

CONCLUSIONS

Our framework provides a basis for greater understanding and study of the ways in which preclinical medical students think about their personal values and visions for service in potential future surgical careers. This research can guide early interventions in medical education to promote diversity and care for the underserved in surgery.

Tracking Surgical Education Survey Research Through the APDS Listserv

OBJECTIVE

Survey-based studies are cornerstones in medical education research. The Association of Program Directors in Surgery (APDS) listserv offers a method to contact program directors (PD) and residents for such research. To facilitate research beneficial to the APDS, improve the quality of survey-based research and minimize survey fatigue, the APDS research committee (ARC) developed a survey review process to grant access to the listserv for research. This study was conducted to determine the impact of the review process on the quality of survey-based research and eventual publication.

DESIGN

This log was systematically reviewed identifying publications resulting from accepted surveys. Publications were categorically analyzed to determine the components of their survey tool methodology, response rate (RR), and medical education research study quality instrument (MERSQI) score.

SETTING

The ARC used a 2-reviewer peer-review process for survey distribution requests. The request was either accepted, rejected, or returned for revision. Accepted surveys were distributed through the listserv with an ARC attestation of approval.

PARTICIPANTS

A log of all survey requests maintained from 2014 to 2017 and subsequent publications.

RESULTS

Thirty-five requests were accepted (40%), 30 were reviewed discovering 10 surveys that led to 12 publications (publication rate of 33%). The average RR was 60% (SD = 29%). Detailed explanations of survey development strategies were reported in 5 (42%), consisting of methods building validity evidence such as expert consensus, modified Delphi method, and pilot group sampling. Half of study participants were PD (50%). MERSQI scores averaged 10 (SD = 1.6).

CONCLUSION

Based on those survey research published to date, the ARC survey peer-review process has enabled most accepted surveys to achieve adequate RR. Although the pool of accepted requests is small, it does highlight areas of improvement. With further refinement of the process, including questioning the survey development methods, the process and listserv can be a powerful tool for further research.

A Library Approach to Cationic Amphiphilic Polyproline Helices that Target Intracellular Pathogenic Bacteria

A number of pathogenic bacteria reproduce inside mammalian cells and are thus inaccessible to many antimicrobial drugs. Herein, we present a facile method to a focused library of antibacterial agents known as cationic amphiphilic polyproline helices (CAPHs). We identified three CAPHs from the library with superior cell penetration within macrophages and excellent antibacterial action against both Gram-positive and Gram-negative bacteria. These cell-penetrating antibacterial CAPHs have specific subcellular localizations that allow for targeting of pathogenic bacteria at their intracellular niches, a unique feature that promotes the successful clearance of intracellular pathogens ( Salmonella, Shigella, and Listeria) residing within macrophages. Furthermore, the selected CAPHs also significantly reduced bacterial infections in an in vivo model of Caenorhabditis elegans, with minimal in vivo toxicity.

Hepatocyte transplantation: past efforts, current technology, and future expansion of therapeutic potential

Hepatic cell transplantation (HCT) continues to garner interest as an alternative to orthotopic liver transplantation and the attendant donor shortage. When compared with solid organ transplantation, advantages of cell transplantation include the potential to treat more patients with a considerably less invasive procedure, the ability to utilize organs otherwise unsuitable for transplant, and leaving the native organ in situ with the potential for regeneration. While studies date back to the early 1960s, advancement of clinical application has been slow due in part to limitations of suitable tissue supplies and reproducible robust techniques. Compared with orthotopic liver transplantation, there are fewer absolute contraindications for donor selection. And, current techniques used to harvest, isolate, store, and even transfuse cells vary little between institutions. Significant variation is seen due to a lack of consensus with maintenance therapy. Although the ideal recipient has not been clearly identified, the most significant results have been demonstrated with correction of congenital metabolic liver disorders, with a few trials examining its utility in cirrhotics and more recently acute liver failure. The most exciting new topic of discussion examines techniques to improve engraftment, with many such as ischemic preconditioning and nonselective partial embolization (microbead therapy), while not yet used in HCT study, showing promise in solid organ research. Advancements in HCT, although slow in progress, have great potential in the ability to alleviate the burden faced in solid organ transplantation and possibly become a long-term viable option, beyond that of a bridge or salvage therapy.

OH sensor based on ultraviolet, continuous-wave absorption spectroscopy utilizing a frequency-quadrupled, fiber-amplified external-cavity diode laser

The development of an all-solid-state cw laser system for optical absorption measurements of the OH radical in the UV spectral range is described. The tunable output of a 1064-nm external-cavity diode laser is amplified by use of a Nd:doped, double-clad fiber amplifier. The amplified near-IR radiation is frequency doubled by a periodically poled lithium niobate crystal and then quadrupled in a beta-barium borate crystal. The design and operation of the system and measurements of OH absorption in the (2, 0) band of the A(2)?(+)- X(2)? electronic transition are discussed.