Academic versus Community Retinal Surgery for Primary Retinal Detachment: Characteristics, Duration, and Value Analysis of Teaching Modifier.

PURPOSE: To compare operative time and case characteristics of primary rhegmatogenous retinal detachment (RRD) repairs between academic and community vitreoretinal surgeons. DESIGN: A retrospective, observational clinical study. SUBJECTS: Patients who underwent primary RRD repair surgeries at Massachusetts Eye and Ear between 2019 and 2021. METHODS: A random sample of 20 vitreoretinal surgeons distributed evenly among the academic or community setting was selected. Fifteen consecutive cases of primary RRD repair surgeries were included from each surgeon. A cost analysis was performed for the teaching modifier for the physician fee and for hospital costs. MAIN OUTCOME MEASURES: Length of surgery. RESULTS: Of 300 primary RRD repairs, fellows were present in 75%, which comprised all academic surgeon cases and 50% of community surgeon cases, P < 0.001. Mean operation length was shorter for community surgeon cases without fellows (55.0 ± 24.1) than either academic (73.0 ± 30.8) or community surgeon cases with fellows (75.7 ± 32.5) (P < 0.001). There was a higher percentage of macula-off RRDs in academic versus community surgeon cases (52.7% vs. 38.0%, P = 0.002) and higher rates of combined scleral buckle (SB)/pars plana vitrectomy (PPV) repairs (14% vs. 3%, P < 0.001). When excluding combined SB/PPV cases, there was no difference in operative time between academic and community surgeon cases. Among RRDs repaired by PPV only, there was a 31.4% (16.6 minutes) greater procedure duration in cases with fellows compared with cases without fellows (P < 0.001). Covariates associated with greater surgery time: addition of an SB (ß = 32.6), membrane peel (ß = 18.5), presence of a fellow (ß = 14.5), proliferative vitreoretinopathy (ß = 12.8), and greater number of retinal breaks (ß = 2.4). The teaching modifier adds 16% extra reimbursement ($184.16) to the physician fee, which is 50.9% of what is necessary to cover the percentage increase in surgeon time (31.4%). Using a time-driven activity-based costing for hospital costs, the extra 16.6 minutes leads to an additional $1038.00, which is 5.6 times more than the reimbursement for the modifier. CONCLUSIONS: Retinal detachment repair cases performed by academic surgeons are more likely to be macula-off and include the addition of an SB, which drive longer operative times. Medicare's reimbursement of the assistant modifier in a teaching facility significantly undercompensates the time-driven activity-based costing of trainee participation. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Away Rotations in Obstetrics and Gynecology: A Survey of Program Directors.

OBJECTIVE: To evaluate residency program director views on the purpose and value of an away rotation for students applying to a residency application in Obstetrics and Gynecology (OBGYN). DESIGN, SETTING, AND PARTICIPANTS: The Council on Resident Education in Obstetrics and Gynecology administered a 28-question survey to current U.S. program directors in OBGYN in 2022. Program directors were asked if they offered away rotations to visiting medical students and if so, what the purpose the rotation played in their application process and whether rotating students were automatically offered a residency interview. Program characteristics such as program size, geographic location, and program type (university, community, or military based) were ascertained. A test of proportions was utilized to understand the relationship between program description and survey responses. RESULTS: Seventy-nine percent (224/285) of OBGYN PDs responded to the survey and consented to participation. Programs were representative of the types of training program, size of programs, and geographic location. Of respondents, 77.2% (173/224) of PDs indicated that away rotations were offered at their institution, but only 26.6% (46/173) of residency PDs assessed prospective candidates for away electives. The opportunity to provide students an audition for a residency position was the most common reason to offer an elective. Only 34.7% (60/173) of OBGYN PDs guaranteed an interview to students who completed away electives at their institution. The majority (118/173, 68.2%) of PDs indicated less than 25% of their current residents had completed an away rotation with their program. CONCLUSIONS: Many residency programs offered away electives to prospective applicants, but the majority did not personally assess applicants for competitiveness or guarantee interviews to students completing electives. To increase transparency in the application process, programs should publicize the purpose of away rotations and provide information on the number of interviews granted to students who complete away rotations.

Community distress and risk of adverse outcomes after peripheral vascular intervention.

INTRODUCTION: Community distress is associated with adverse outcomes in patients with cardiovascular disease; however, its impact on clinical outcomes after peripheral vascular intervention (PVI) is uncertain. The Distressed Communities Index (DCI) is a composite measure of community distress measured at the zip code level. We evaluated the association between community distress, as measured by the DCI, and 24-month mortality and major amputation after PVI. METHODS: We used the Vascular Quality Initiative database, linked with Medicare claims data, to identify patients who underwent initial femoropopliteal PVI between 2017 and 2018. DCI scores were assigned using patient-level zip code data. The primary outcomes were 24-month mortality and major amputation. We used time-dependent receiver operating characteristic curve analysis to determine an optimal DCI value to stratify patients into risk categories for 24-month mortality and major amputation. Mixed Cox regression models were constructed to estimate the association of DCI with 24-month mortality and major amputation. RESULTS: The final cohort consisted of 16,864 patients, of whom 4734 (28.1%) were classified as having high community distress (DCI ≥70). At 24 months, mortality was elevated in patients with high community distress (30.7% vs 29.5%, P = .02), as was major amputation (17.2% vs 13.1%, P <.001). After adjusting for demographic and clinical characteristics, a 10-point higher DCI score was associated with increased risk of mortality (hazard ratio: 1.01; 95% confidence interval: 1.00-1.03) and major amputation (hazard ratio: 1.02; 95% confidence interval: 1.00-1.04). CONCLUSIONS: High community distress is associated with increased risk of mortality and major amputation after PVI.

Current Communication Practices Between Obstetrics and Gynecology Residency Applicants and Program Directors.

Importance: In order to equitably improve the residency application process, it is essential to understand the problems we need to address. Objective: To determine how obstetrics and gynecology (OBGYN) applicants and faculty communicate applicants' interest to residency programs, and how program directors report being influenced by these communications. Design, Setting, and Participants: This survey study was conducted with email surveys of OBGYN application stakeholders in 2022. Included participants were OBGYN applicants, clerkship directors, and residency program directors in medical education associations' email listservs. Exposures: Surveys sent by the American Association of Medical Colleges, Association of Professors of Gynecology and Obstetrics, and Council on Resident Education in Obstetrics and Gynecology. Main Outcomes and Measures: Whether applicants themselves, or faculty on their behalf, communicated to residency programs, and the influence program directors reported placing on these communications for their decision-making. Descriptive statistics and χ2 tests were used to analyze differences. Results: A total 726 of 2781 applicants (26.1%) responded to the survey and were included in analysis (79 of 249 [31.7%] clerkship directors; 200 of 280 [71.4%] program directors). The self-reported racial and ethnic demographics of the 726 applicant respondents were 86 Asian (11.8%), 54 Black (7.4%), 41 Latinx (5.6%), 1 Native Hawaiian or Pacific Islander (0.1%), 369 White (52.2%), 45 with multiple racial identities (6.2%), and 91 (21.5%) preferring not to answer. The majority of applicants (590 [82.9%]) sent communications at some point in the application process. Applicants who identified as White (336 [88.7%]) or Asian (75 [87.2%]) were more likely than those who identified as Black (40 [74.1%]) or Latinx (33 [80.5%]) to reach out to programs (P = .02). There were also differences in type of medical school, with 377 of 427 MD applicants (88.3%), 109 of 125 DO applicants (87.2%), and 67 of 87 International Medical Graduate applicants (77.7%) reporting sending communications (P = .02). Approximately one-third (254 applicants [35.7%]) had faculty reach out to programs on their behalf. White (152 [40.1%]) and Asian (37 [43.0%]) applicants were more likely to have faculty reach out compared with Black (6 [11.1%]) and Latinx (12 [29.3%]) applicants (P = .01). Program directors reported that preinterview communications from faculty they knew (64 [32.2%]) and other program directors (25 [12.6%]) strongly influenced their decisions, and otherwise rarely reported that communications strongly influenced their decisions. Conclusions and Relevance: The current state of communications may increase inequities in residency application processes; differences between faculty communications for applicants from different racial and ethnic backgrounds are particularly concerning given that program directors are more likely to weigh communications from faculty in their decision-making. A centralized, equitable means for applicants to signal their interest to programs is urgently needed.

How We Do It: Student Perspectives on Changes to the Obstetrics and Gynecology Residency Application Process.

OBJECTIVE: To describe the perspectives of obstetrics and gynecology (OBGYN) residency applicants regarding new standards for the 2019 to 2020 application cycle. DESIGN: An anonymous electronic survey was sent to all OBGYN residency applicants to US programs retrospectively evaluating 5 new recommended standards for the application process. This 15-item survey assessed the importance of the proposed standards and their impact on applicants' anxiety. SETTING: The OBGYN residency application process is marked by increasing application numbers and no standardization for managing interview offers. The Association of Professors of Gynecology and Obstetrics (APGO) received a 5-year Reimagining Residency grant from the American Medical Association to improve the transition from undergraduate medical education (UME) to graduate medical education (GME) within OBGYN. The multiphase project, "Transforming the UME to GME Transition for Obstetrics and Gynecology- Right Resident, Right Program, Ready Day One (RRR)," began with Standardizing the OBGYN Application and Interview Process (SOAIP). This group recommended 5 new standards for all US OBGYN residency programs and applicants. PARTICIPANTS: Applicants for US OBGYN residency programs for the 2019 to 2020 application cycle completed the survey, with a 904/2508 (36.0%) response rate, including 762 complete responses (30.4%). RESULTS: Applicants reported that all 5 of the new standards would cause the least self-perceived anxiety (range 76.8% - 96.5%). The impact of the standards on perceived anxiety varied by student group, with International Medical Graduates (IMGs) and students with USMLE Step I scores <200 describing lesser impact compared to others. Despite these differences, all 5 standards were consistently noted to cause the least anxiety for all groups. Despite varying degrees of effects in different groups, the new OBGYN residency application standards caused the least anxiety for all subgroups of applicants. CONCLUSIONS: Implementing universal standards for the OBGYN residency application process was favorably perceived by applicants and caused the least anxiety for applicants.

Reliability of translaryngeal airway resistance measurements during maximal exercise.

Objective: Exercise-induced laryngeal obstruction is an important cause of exertional dyspnoea. The diagnosis rests on visual judgement of relative changes of the laryngeal inlet during continuous laryngoscopy exercise (CLE) tests, but we lack objective measures that reflect functional consequences. We aimed to investigate repeatability and normal values of translaryngeal airway resistance measured at maximal intensity exercise. Methods: 31 healthy nonsmokers without exercise-related breathing problems were recruited. Participants performed two CLE tests with verified positioning of two pressure sensors, one at the tip of the epiglottis (supraglottic) and one by the fifth tracheal ring (subglottic). Airway pressure and flow data were continuously collected breath-by-breath and used to calculate translaryngeal resistance at peak exercise. Laryngeal obstruction was assessed according to a standardised CLE score system. Results: Data from 26 participants (16 females) with two successful tests and equal CLE scores on both test sessions were included in the translaryngeal resistance repeatability analyses. The coefficient of repeatability (CR) was 0.62 cmH2O·L-1·s-1, corresponding to a CR% of 21%. Mean±sd translaryngeal airway resistance (cmH2O·L-1·s-1) in participants with no laryngeal obstruction (n=15) was 2.88±0.50 in females and 2.18±0.50 in males. Higher CLE scores correlated with higher translaryngeal resistance in females (r=0.81, p<0.001). Conclusions: This study establishes translaryngeal airway resistance obtained during exercise as a reliable parameter in respiratory medicine, opening the door for more informed treatment decisions and future research on the role of the larynx in health and disease.

Stakeholder Perspectives on Limiting Residency Applications and Interviews in Obstetrics and Gynecology.

PURPOSE: Application inflation in the current residency application process leads to congestion, inefficiency, and perceptions of inequity. The authors aimed to assess the interest of key stakeholders on the topic of capping applications and interviews, and their perceptions regarding equity of the process. METHODS: An anonymous survey was electronically distributed in March 2021 to Obstetrics and Gynecology (OBGYN) residency applicants, clerkship directors, program directors, and student affairs deans after the submission of the rank order list for the 2021 application cycle and prior to the release of final Match results. Participants answered questions regarding the perceived equity of the current process (no limits on applications submitted or interviews completed) compared with limiting the number of applications and interviews students could submit or complete. Respondents supporting caps reported the number they considered a reasonable cap for applications and interviews. Associations between the profiles of applicants and program directors and their interest in application and interview caps were explored using chi-squared tests for non-parametric statistics and t-tests for normally distributed interval data. The University of Michigan determined the study exempt from IRB review. RESULTS: The overall response rate was 36.0% (1167/3243), including 34.0% of applicants (879/2579), 50.3% of program directors (143/284), 41.8% of clerkship directors (94/225) and 32.9% of student affairs deans (51/155). All groups reported application caps for either all applicants or the most competitive applicants to be more equitable than the current process, and suggested a median application cap ranging from 25 (clerkship directors and program directors) to 40 (applicants). All groups also believed interview caps to be more equitable than the current process, and suggested a median interview cap ranging from 12 (clerkship directors) to 15 (applicants, program directors, and student affairs deans). CONCLUSIONS: Stakeholders in the OBGYN application process consider caps to applications and interviews a promising means to improve equity in the Match.

An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput CRISPRi screens.

The trafficking of specific protein cohorts to correct subcellular locations at correct times is essential for every signaling and regulatory process in biology. Gene perturbation screens could provide a powerful approach to probe the molecular mechanisms of protein trafficking, but only if protein localization or mislocalization can be tied to a simple and robust phenotype for cell selection, such as cell proliferation or fluorescence-activated cell sorting (FACS). To empower the study of protein trafficking processes with gene perturbation, we developed a genetically encoded molecular tool named HiLITR (High-throughput Localization Indicator with Transcriptional Readout). HiLITR converts protein colocalization into proteolytic release of a membrane-anchored transcription factor, which drives the expression of a chosen reporter gene. Using HiLITR in combination with FACS-based CRISPRi screening in human cell lines, we identified genes that influence the trafficking of mitochondrial and ER tail-anchored proteins. We show that loss of the SUMO E1 component SAE1 results in mislocalization and destabilization of many mitochondrial tail-anchored proteins. We also demonstrate a distinct regulatory role for EMC10 in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex. Through transcriptional integration of complex cellular functions, HiLITR expands the scope of biological processes that can be studied by genetic perturbation screening technologies.

Outcome analysis of 95 harness racehorses with confirmed dorsal displacement of the soft palate treated with laryngeal tie-forward surgery.

BACKGROUND: The laryngeal tie-forward (LTF) procedure is commonly used to treat intermittent dorsal displacement of the soft palate (iDDSP). There is a wide range in reported efficacy of treating horses with and without a definitive diagnosis of iDDSP. OBJECTIVES: To evaluate the racing performance of harness racehorses in which iDDSP had been definitely diagnosed and treated solely with the LTF procedure. STUDY DESIGN: Retrospective case series. METHODS: Ninety-five harness racehorses were treated with LTF for confirmed iDDSP. A definite diagnosis of iDDSP was made with high-speed treadmill or overground endoscopy. Upper respiratory tract (URT) disorders, short-term complications, and horses returning for recurrence of URT problems were recorded. Performance before and after LTF was assessed by reviewing career race records and comparing performance index (PI), and racing speed marks from the baseline, preoperative, and postoperative periods. The effect of basihyoid-cricoid (BC) net distance shortened on racing performance was assessed. RESULTS: Postoperatively, PI increased in 36/54 (67%, 95% CI 54%-79%) of experienced racehorses, and 44/67 (66%, 54%-77%) established or improved their racing speed mark relative to the preoperative period. As a group, PI decreased by a mean (SE) of 0.9 (0.17) points (P < .001) prior to diagnosis/surgery. Postoperatively, PI increased by 0.5 (0.16) points (P = .003), and racing speed improved by 0.83 (0.22) s (P < .001). Twenty-five percent (17%-34%) and 49% (39%-60%) of horses did not demonstrate a decline in PI and racing speed prior to diagnosis, respectively. Net BC distance shortening did not affect performance postoperatively. Twenty of 95 horses (21%, 13%-29%) had confirmed recurrence of iDDSP 46-708 days postoperatively. MAIN LIMITATIONS: Not all horses were evaluated with exercising endoscopy postoperatively. Racehorses inevitably develop other racing-related problems which confound studies of this nature. CONCLUSIONS: This study provides scientific support for the use of LTF to treat iDDSP in harness racehorses although iDDSP seems to affect harness racehorses differently as individuals.

A bitless bridle does not limit or prevent dynamic laryngeal collapse.

BACKGROUND: Bits have often been incriminated as a cause of upper respiratory tract obstruction in horses; however, no scientific studies are available to confirm or refute these allegations. Clinical signs of dynamic laryngeal collapse associated with poll flexion (DLC) are induced when susceptible horses are ridden or driven into the bit. OBJECTIVE: To determine whether use of Dr Cook's™ Bitless Bridle, instead of a conventional snaffle bit bridle, would reduce the severity of DLC in affected horses measured objectively using inspiratory tracheal pressures. STUDY DESIGN: Intervention study using each horse as its own control in a block randomised order. METHODS: Nine Norwegian Swedish Coldblooded trotters previously diagnosed with DLC were exercised on two consecutive days using a standardised high-speed treadmill protocol with either a conventional bridle with a snaffle bit, or Dr Cook's™ Bitless Bridle. Head and neck position, rein tension, inspiratory tracheal pressure measurements, and laryngeal videoendoscopy recordings were obtained. A heart rate greater than 200 bpm, and similar degrees of poll flexion/head height, had to be achieved in both bridles for the individual horse's data to be included for comparison. RESULTS: Seven horses' data met the inclusion criteria. The change in mean inspiratory tracheal pressure between free and flexion phases in the bitless bridle (-15.2 ± 12.3 cmH2 O) was significantly greater (P < .001) than in the snaffle bit bridle (-9.8 ± 7.9 cmH2 O). Mean inspiratory pressure during the free phase was significantly (P < .001) more negative with the snaffle bit bridle (-32.3 ± 6.3 cmH2 O), vs the bitless bridle (-28.5 ± 6.9 cmH2 O). Mean pressures in flexion phase, snaffle bridle (-42.1 ± 10.8 cmH2 O), vs bitless bridle (-43.7 ± 15.6 cmH2 O) where not significantly different between bridles (P = .2). MAIN LIMITATION: Small sample size due to difficulty recruiting suitable clinical cases. CONCLUSIONS: This study could not provide any clear evidence that the effect of a snaffle bit in a horse's mouth influences the development or severity of DLC. Instead, head and neck angles induced by rein tension seem to be the key event in provoking DLC in susceptible horses.

The Case for Capping Residency Interviews.

OBJECTIVE: To determine 2020 residency cycle application practices and to model potential consequences in the 2021 cycle if (1) applicants scheduled an uncapped number of interviews; (2) applicants were capped to schedule 12 interviews; (3) residency programs kept their number of interview offers unchanged; and (4) programs increased their interview offers by 20%. DESIGN AND SETTING: The authors sent an anonymous survey to all obstetrics and gynecology applicants registered through the Electronic Residency Application Service in February 2020 asking respondents to share demographics and number of interview offers received and completed. Based on prior estimates that 12 interviews are needed to match in obstetrics and gynecology, respondents were divided into Group 12+ (those receiving ≥12 interview offers) and Group <12 (those receiving <12 offers). Model assumptions were (1) applicants can complete all interviews they are offered because they are virtual; (2) interview offers that applicants in Group 12+ decline are subsequently offered to applicants in Group <12; (3) the proportions of interviews offered to Group 12+ and Group <12 will remain the same if programs chose to increase their total number of interview spots. PARTICIPANTS: Among 2508 applicants, 750 (30%) provided the number of interview offers received and completed: 417 (56%) in Group 12+ and 333 (44%) in Group <12. RESULTS: In models where applicants are uncapped in the number of interviews, Group <12 applicants receive <1 interview offer, even if programs increase the number of interviews offered and performed. If applicants are capped at 12 interviews, Group <12 applicants will receive 9 interview offers on average and will reach 12 if programs increase the number of interviews offered by 20%. CONCLUSIONS: This work highlights how current inefficiencies may lead to negative consequences with virtual interviews. Interview caps and preference signaling systems need to be urgently considered.

Can Standardized Dates for Interview Offers Mitigate Excessive Interviewing?

OBJECTIVE: To determine the impact of specialty-specific guidelines for standardized interview offers on residency applicant behavior towards excessive interviewing. DESIGN: In 2019 to 2020, the Association of Professors of Gynecology and Obstetrics and the Council on Resident Education in Obstetrics and Gynecology (OBGYN) outlined standard dates for residency interview offers. A cross-sectional survey of applicants queried adherence to standardized interview offers, the number of interviews offers received, interviews completed, and application characteristics. Based on data that applicants in OBGYN with a mean number of 12 contiguous ranks are highly likely to match, factors associated with accepting an excessive percentage of interview offers were investigated in applicants with at least 12 interviews, using multiple logistic regression. SETTING: All OBGYN applicants were sent an anonymous electronic survey distributed through the Electronic Residency Application Service in February 2020, with the subset of US MD senior respondents selected for this analysis. PARTICIPANTS: There were a total of 1292 US MD senior applicants into OBGYN in 2020, with 505 (39%) providing their interview information through the survey. Three hundred and sixty (71%) of US MD senior respondents received at least 12 interviews. RESULTS: Applicants receiving at least 12 interview offers completed a median of 83% of their interviews, and excessive interviewing was defined as completing greater than this median percentage. Receiving most interview offers on standardized interview offer dates resulted in less excessive interviewing despite controlling for number of programs applied to, applying as a couple, and United States Medical Licensing Exams Step 1 score. CONCLUSIONS: The standardization of interview offer dates may mitigate interview inflation by altering applicant behavior. This promising pilot data suggests that applicants may be able to make more informed decisions about which interview offers to accept when all offers are received on predetermined dates.

Stakeholder Perspectives on Standardizing the Residency Application and Interview Processes.

OBJECTIVE: The purpose of this study was to examine stakeholder perspectives on recommended standards for the obstetrics and gynecology (OBGYN) residency application and interview processes proposed for the 2019 to 2020 application cycle. The authors aimed to assess the acceptance and perception of key stakeholders on the feasibility of implementing the standards as well as the effect of these changes on applicant anxiety. DESIGN AND SETTING: The authors electronically distributed an anonymous survey in February 2020 to OBGYN residency applicants, clerkship directors, student affairs deans, program directors, and program managers. Participants received a 15-item survey, with questions assessing the importance and adoption of the guidelines, as well as their effect on perceived applicants' anxiety. Responses were measured on a 5-item Likert scale. Multiple regression analysis was used to explore which residency factors were associated with compliance with the standards. IRB exemption was granted by the University of Michigan. PARTICIPANTS: A total of 1358 participants completed the survey for an overall response rate of 39.26%. Response rates were 36.04% for applicants (904/2508), 46.67% for CDs (105/225), 34.84% for members of GSAs (34/155), 59.43% for program directors (167/281), and 51.03% for program managers (148/290). RESULTS: The overall response rate was 39.26% (1358/3459) with 36.04% of applicants (904/2508), 46.67% of clerkship directors (105/225), 34.84% of student affairs deans (34/155), 59.43% of program directors (167/281), and 51.03% of program managers (148/290). The recommendations were perceived as important by all stakeholders. More than 90% of program directors reported compliance with some or all of the recommendations and more than 90% of all applicants, clerkship directors and student affairs deans reported that the standards reduced applicant anxiety. All stakeholders rated each guideline to be important to extremely important. CONCLUSIONS: This study demonstrates the feasibility and acceptance of universal standards for the residency application process in the field of OBGYN. The vast majority of stakeholders surveyed supported the initiative and participated in the guidelines. Applicant respondents perceived the guidelines to be important and to decrease anxiety surrounding the application and interview timelines. These findings are important for other specialties when considering similar interventions.

A genome-wide scan for candidate lethal variants in Thoroughbred horses.

Domestic animal populations are often characterised by high rates of inbreeding and low effective population sizes due to selective breeding practices. These practices can result in otherwise rare recessive deleterious alleles drifting to high frequencies, resulting in reduced fertility rates. This study aimed to identify potential recessive lethal haplotypes in the Thoroughbred horse breed, a closed population that has been selectively bred for racing performance. In this study, we identified a haplotype in the LY49B gene that shows strong evidence of being homozygous lethal, despite having high frequencies of heterozygotes in Thoroughbreds and other domestic horse breeds. Variant analysis of whole-genome sequence data identified two SNPs in the 3'UTR of the LY49B gene that may result in loss of function. Analysis of transcriptomic data from equine embryonic tissue revealed that LY49B is expressed in the trophoblast during placentation stage of development. These findings suggest that LY49B may have an essential, but as yet unknown function in the implantation stage of equine development. Further investigation of this region may allow for the development of a genetic test to improve fertility rates in horse populations. Identification of other lethal variants could assist in improving natural levels of fertility in horse populations.

Dynamic laryngeal collapse associated with poll flexion as a complication of laryngeal tie-forward surgery in three harness racehorses.

OBJECTIVE: To report dynamic laryngeal collapse (DLC) associated with poll flexion as a potential complication of the laryngeal tie-forward procedure (LTFP) in harness racehorses. STUDY DESIGN: Short case series. ANIMALS: Three harness racehorses. METHODS: Preoperative and postoperative medical records of all harness racehorses that underwent the LTFP were reviewed, as were high-speed treadmill videoendoscopy recordings of 35 horses that returned for upper airway evaluation postoperatively. RESULTS: One standardbred and two Norwegian coldblooded trotters in which dorsal displacement of the soft palate had been initially diagnosed were found to have bilateral arytenoid cartilage and vocal fold collapse associated with poll flexion after the LTFP. These three horses were otherwise clinically normal when exercised in free head carriage. CONCLUSION: Dynamic laryngeal collapse associated with poll flexion can occur as a complication after the LTFP in harness racehorses and should be considered as a differential in horses with persistence of airway problems after surgery. CLINICAL SIGNIFICANCE: Postoperative DLC may be underdiagnosed in harness racehorses because this complication is obvious only when horses are driven with bit and reins during high speed treadmill or overground videoendoscopy.

Molecule Isomerism Modulates the Diradical Properties of Stable Singlet Diradicaloids.

Inclusion of quinoidal cores in conjugated hydrocarbons is a common strategy to modulate the properties of diradicaloids formed by aromaticity recovery within the quinoidal unit. Here we describe an alternative approach of tuning of diradical properties in indenoindenodibenzothiophenes upon anti → syn isomerism of the benzothiophene motif. This alters the relationship of the S atom with the radical center from linear to cross conjugation yet retains the same 2,6-naphtho conjugation pattern of the rearomatized core. We conduct a full comparison between the anti and syn derivatives based on structural, spectroscopic, theoretical, and magnetic measurements, showing that these systems are stable open-shell singlet diradicaloids that only access their triplet state at elevated temperatures.

Exercise Induced Laryngeal Obstruction in Humans and Equines. A Comparative Review.

Dynamic obstructions of the larynx are a set of disorders that occur during exercise in equines and humans. There are a number of similarities in presentation, diagnosis, pathophysiology and treatment. Both equines and humans present with exercise intolerance secondary to dyspnea. During laryngoscopy at rest, the larynx appears to function normally. Abnormalities are only revealed during laryngoscopy at exercise, seemingly triggered by increased ventilatory demands, and quickly resolve after cessation of exercise. Lower airway disease (asthma being the most prevalent condition), cardiac disease and lack of fitness are the major differentials in both species. Laryngoscopic examination during exercise should be performed from rest to peak exertion to allow for a comprehensive diagnosis, including where the airway collapse begins, and thereafter how it progresses. Dynamic disorders with most visual similarity between humans and equines are: aryepiglottic fold collapse (both species); equine dynamic laryngeal collapse (DLC) relative to some forms of human combined supraglottic/glottic collapse; and epiglottic retroversion (both species). Quantitative grading techniques, such as airway pressure measurement, that have proven effective in veterinary research are currently being piloted in human studies. Conditions that appear visually similar are treated in comparable ways. The similarities of anatomy and certain types of dynamic collapse would suggest that the equine larynx provides a good model for human upper respiratory tract obstruction during exercise. Thus, close collaboration between veterinarians and medical personal may lead to further advancements in understanding pathophysiologic processes, and enhance the development of improved diagnostic tests and treatments that will benefit both species.

Genomic measures of inbreeding in the Norwegian-Swedish Coldblooded Trotter and their associations with known QTL for reproduction and health traits.

BACKGROUND: Since the 1950s, the Norwegian-Swedish Coldblooded trotter (NSCT) has been intensively selected for harness racing performance. As a result, the racing performance of the NSCT has improved remarkably; however, this improved racing performance has also been accompanied by a gradual increase in inbreeding level. Inbreeding in NSCT has historically been monitored by using traditional methods that are based on pedigree analysis, but with recent advancements in genomics, the NSCT industry has shown interest in adopting molecular approaches for the selection and maintenance of this breed. Consequently, the aims of the current study were to estimate genomic-based inbreeding coefficients, i.e. the proportion of runs of homozygosity (ROH), for a sample of NSCT individuals using high-density genotyping array data, and subsequently to compare the resulting rate of genomic-based F (FROH) to that of pedigree-based F (FPED) coefficients within the breed. RESULTS: A total of 566 raced NSCT were available for analyses. Average FROH ranged from 1.78 to 13.95%. Correlations between FROH and FPED were significant (P < 0.001) and ranged from 0.27 to 0.56, with FPED and FROH from 2000 to 2009 increasing by 1.48 and 3.15%, respectively. Comparisons of ROH between individuals yielded 1403 regions that were present in at least 95% of the sampled horses. The average percentage of a single chromosome covered in ROH ranged from 9.84 to 18.82% with chromosome 31 and 18 showing, respectively, the largest and smallest amount of homozygosity. CONCLUSIONS: Genomic inbreeding coefficients were higher than pedigree inbreeding coefficients with both methods showing a gradual increase in inbreeding level in the NSCT breed between 2000 and 2009. Opportunities exist for the NSCT industry to develop programs that provide breeders with easily interpretable feedback on regions of the genome that are suboptimal from the perspective of genetic merit or that are sensitive to inbreeding within the population. The use of molecular data to identify genomic regions that may contribute to inbreeding depression in the NSCT will likely prove to be a valuable tool for the preservation of its genetic diversity in the long term.

Alar fold resection in 25 horses: Clinical findings and effect on racing performance and airway mechanics (1998-2013).

OBJECTIVE: To report clinical findings and performance in horses in which alar fold collapse (AFC) had been diagnosed and surgically treated and to assess form and degree of respiratory obstruction. STUDY DESIGN: Retrospective case series. ANIMALS: Twenty-one standardbreds, 2 coldblooded trotter racehorses, 1 thoroughbred, and 1 Icelandic horse. METHODS: Alar fold collapse was diagnosed on the basis of continuous abnormal expiratory flutter noise coinciding with filling of the false nostrils during exercise on a high-speed treadmill that was alleviated by suturing the alar folds (AF) temporarily in a dorsal position. In 5 cases, nasopharyngeal airway pressures were assessed. Performance after complete, bilateral AF resection was assessed by reviewing career race records and by owner or trainer telephone interviews. RESULTS: Horses presented because of poor performance, abnormal respiratory noise, or both. Additional dynamic disorders were identified in 12 of 21 standardbreds (intermittent dorsal displacement of the soft palate: n = 10; collapse of the roof of the nasopharynx: n = 2). Expiratory nasopharyngeal pressures seemed elevated in horses with AFC (range, +10.8 to +21.8 cm H2 O) compared with normal reference values. Dorsal fixation as well as complete surgical resection of the AF improved expiratory nasopharyngeal pressures to reported normal levels. At a mean of 68 months (range, 7-121) follow-up, 20 of 25 horses had competed after surgery, and 13 of 17 of the harness racehorses had established or improved their kilometer racing time marks. CONCLUSION: Alar fold collapse caused mild to moderate expiratory obstruction and may have contributed to secondary nasopharyngeal collapse in this population. CLINICAL SIGNIFICANCE: Complete surgical resection seems effective for treating AFC. Nasopharyngeal pressure measurement is a potential tool for confirming the diagnosis of AFC.