New materials for improving catches of horseflies (Diptera: Tabanidae) in Nzi traps.

New materials in 85 configurations were tested relative to standard fabric Nzi traps to improve catches of tabanids based on artificial visual cues that mimic those used in nature for locating hosts or water. Colour-fast synthetic fabrics and photo-selective horticultural mesh were tested to facilitate insecticide impregnation and for improved durability. Many plastics were explored to document how flies react to polarized and visible vs. ultraviolet light. Lastly, sticky horizontal, linearly polarizing ground-level shiny plastic targets were tested for capturing water-seeking tabanids relative to traps and vertical fabric targets. Based on the capture of 281 786 female Tabanidae (Tabanus Linnaeus, Hybomitra Enderlein, Chrysops Meigen), four alternative formats provided higher catches and/or durability. They were substituting: (1) phthalogen turquoise for phthalogen blue, (2) solution-dyed fabrics for blue and black cotton, (3) clear/white horticultural mesh for mosquito netting, and (4) clear, reflective plastic for some or all netting. A Sunbrella/BioNet fabric trap (portable) and a blue-black Plexiglas®/netting trap (fixed applications) consistently performed best (1.5-3 × higher catches). Ground-level targets captured many male and gravid female Hybomitra but were ineffective for Tabanus. Traps and vertical fabric or transparent sticky targets captured mainly unfed females.

Esophageal provocation tests: Are they useful to improve diagnostic yield of high resolution manometry?

High resolution manometry (HRM) is the gold standard to diagnose esophageal motility disorders but has some limitations. The inclusion of provocative tests might enhance the diagnostic yield of HRM. These tests are easy to perform and to add to the regular manometry protocol. Multiple rapid swallows (MRS; 5 2-mL swallows) is useful to assess the contractile reserve and deglutitive inhibition. The optimal number of MRS to perform might be 3 as suggested by Mauro et al. in this issue of Neurogastroenterology & Motility. The absence of contractile reserve might be associated with gastro-esophageal reflux disease and with an increased risk of post fundoplication dysphagia. Single viscous and solid swallows might enhance the detection of esophageal motility disorders but are not significantly associated with symptom occurrence. Test meal has the advantage to represent a real-life scenario and is promising to depict significant motility findings responsible for esophageal symptoms. Post-prandial recording might also be of interest to diagnose rumination and belching disorders. The best indication of rapid drink challenge test (free drinking of 200 mL) is currently the diagnosis of esophago-gastric junction obstruction. Finally, abdominal compression might be an option to evaluate response of esophageal peristalsis in a context of outflow resistance as proposed by Brink et al. in this issue. These provocative maneuvers appear to provide a complementary role in the evaluation of esophageal motility but require prospective studies to determine the validity of the findings and whether they will lead to changes in clinical practice.

Validation of the oesophageal hypervigilance and anxiety scale for chronic oesophageal disease.

BACKGROUND: Oesophageal hypervigilance and anxiety can drive symptom experience in chronic oesophageal conditions, including gastro-oesophageal reflux disease, achalasia and functional oesophageal disorders. To date, no validated self-report measure exists to evaluate oesophageal hypervigilance and anxiety. AIMS: This study aims to develop a brief and reliable questionnaire assessing these constructs, the oesophageal hypervigilance and anxiety scale (EHAS). METHODS: Questions for the EHAS were drawn from 4 existing validated measures that assessed hypervigilance and anxiety adapted for the oesophagus. Patients who previously underwent high-resolution manometry testing at a university-based oesophageal motility clinic were retrospectively identified. Patients were included in the analysis if they completed the EHAS as well as questionnaires assessing symptom severity and health-related quality of life at the time of the high-resolution manometry. RESULTS: Nine hundred and eighty-two patients aged 18-85 completed the study. The EHAS demonstrates excellent internal consistency (α = 0.93) and split-half reliability (Guttman = 0.87). Inter-item correlations indicated multicollinearity was not achieved; thus, no items were removed from the original 15-item scale. Principal components factor analysis revealed two subscales measuring symptom-specific anxiety and symptom-specific hypervigilance. Construct validity for total and subscale scores was supported by positive correlations with symptom severity and negative correlations with health-related quality of life. CONCLUSIONS: The EHAS is a 15-item scale assessing oesophageal hypervigilance and symptom-specfic anxiety. The EHAS could be useful in evaluating the role of these constructs in several oesophageal conditions in which hypersensitivity, hypervigilance and anxiety may contribute to symptoms and impact treatment outcomes.

Inter-rater agreement of novel high-resolution impedance manometry metrics: Bolus flow time and esophageal impedance integral ratio.

BACKGROUND: Novel high-resolution impedance manometry (HRIM) metrics of bolus flow time (BFT) and esophageal impedance integral (EII) ratio have demonstrated clinical utility, though the reliability of their analysis has not been assessed. We aimed to evaluate the inter-rater agreement of the BFT and EII ratio. METHODS: HRIM studies including five upright, liquid swallows from 40 adult patients were analyzed by two raters using a customized MATLAB program to generate the BFT and EII ratio. Inter-rater agreement was assessed using the intraclass correlation coefficient (ICC) for median values generated per patient and also for all 200 swallows. KEY RESULTS: The ICC (95% confidence interval, CI) for BFT was 0.873 (0.759-0.933) for median values and 0.838 (0.778-0.881) for all swallows. The ICC (95% CI) for EII ratio was 0.983 (0.968-0.991) for median values and 0.905 (0.875-0.928) for all swallows. Median values for both BFT and EII ratio were similar between the two raters (P-values .05). CONCLUSIONS AND INFERENCES: The BFT and EII ratio can be reliably calculated as supported by generally excellent inter-rater agreement. Thus, broader utilization of these measures appears feasible and would facilitate further evaluation of their clinical utility.

Evaluating the reliability and construct validity of the Eckardt symptom score as a measure of achalasia severity.

BACKGROUND: Achalasia is a disease of mechanical esophageal dysfunction characterized by dysphagia, chest pain, regurgitation, and malnutrition. The Eckardt symptom score (ESS) is the gold standard self-report assessment tool. Current guidelines outline a three-step approach to patient reported outcomes measure design. Developed prior to these policies, the ESS has not undergone rigorous testing of its reliability and validity. METHODS: Adult achalasia patients retrospectively identified via a patient registry were grouped based on treatment history. Patients were grouped PREPOST (completed ESS, GERDQ, brief esophageal dysphagia questionnaire, NIH PROMIS Global Health, high resolution manometry, timed barium esophagram prior to treatment and after) and POST (completed measures only after treatment). Clinical characteristics, treatment type and date were obtained via medical record. Standardized psychometric analyses for reliability and construct validity were performed. KEY RESULTS: 107 patients identified; 83 POST and 24 PREPOST. The ESS has fair internal consistency and split-half reliability with a single factor structure. Dysphagia accounts for half the variance in ESS, while chest pain and weight loss account for 10% each. Pre-post-surgical assessment demonstrates improvements in ESS, except for weight loss. Effect sizes range from 0.24 to 2.53, with greatest change in regurgitation. Validity of the ESS is supported by modest correlations with GERDQ, HRQOL, and physiological data. CONCLUSIONS & INFERENCES: The ESS demonstrates fair reliability and validity, with a single factor structure mostly explained by dysphagia. Based on psychometric findings, weight loss and chest pain items may be decreasing ESS reliability and validity. Further assessment of the ESS under FDA guidelines is warranted.

High-resolution manometry assessment of the lower esophageal sphincter after-contraction: Normative values and clinical correlation.

BACKGROUND: The Chicago Classification v3.0 proposed extending the distal contractile integral (DCI) measurement domain to include the lower esophageal sphincter (LES) to enhance the detection of esophageal hypercontractility. However, normative and clinical data for this approach are unreported. We aimed to describe the application of an extended DCI measurement in asymptomatic controls and patients. METHODS: High-resolution manometry (HRM) of 65 asymptomatic controls and 72 patients with normal motility were evaluated retrospectively. Dysphagia and chest pain symptoms were assessed using the brief esophageal dysphagia questionnaire (BEDQ); ≥10 was considered abnormal. HRM studies of 10 supine swallows were evaluated via the standard DCI and an extended DCI measurement domain (DCI+) to include the lower esophageal sphincter (LES) during and after the peristaltic wave. The DCI-increment was calculated as the DCI+ minus DCI. KEY RESULTS: Among controls, the median (5-95th percentile) DCI+ was 1915 (1359-6921) mm Hg/cm/s and DCI-increment was 534 (126-1488) mm Hg/cm/s. Two patients (3%) had ≥2 swallows with DCI+ >8000 mm Hg/cm/s and seven (10%) patients had at least one swallow with DCI+ >8000 mm Hg/cm/s, ie, had potential motility reclassification by application of DCI+. Seven of these nine patients (78%) were evaluated for dysphagia or chest pain, but only 3/9 (33%) had an abnormal BEDQ. CONCLUSIONS AND INFERENCES: Extension of the DCI measurement domain may aid quantifying hypercontractility that involves the LES. However, adjusting management strategies based on reclassification of patients with otherwise normal motility should be cautiously considered.

Jackhammer esophagus: Assessing the balance between prepeak and postpeak contractile integral.

BACKGROUND: We hypothesized that symptoms in Jackhammer esophagus (JH) are associated with an imbalance between the prepeak and postpeak phases of contraction. Thus, we developed a method to distinguish the contractile integral components of prepeak and postpeak phase contractile activity to determine the contribution of each phase and their association with dysphagia. METHODS: Patients diagnosed with JH were enrolled and compared to controls. The first five intact swallows during manometry were analyzed. A single swallow was divided into a prepeak and postpeak phase. The contractile integral of each phase and its corresponding time-controlled integral were computed. All metrics were compared between controls and JH patients subcategorized by the impaction dysphagia question (IDQ) score with cut-off of 6. KEY RESULTS: Thirty eight JH patients and 71 controls were included. Twelve JH patients had IDQ ≤ 6 and 26 with IDQ > 6. JH patients had higher contractile integral in both phases, and a higher ratio between postpeak to prepeak contractile integral independent of duration. Similarly, JH patients with an IDQ > 6 had higher contractile metrics than those with IDQ ≤ 6. There was a correlation between the IDQ score and the ratio within the postpeak to prepeak contractile integral (r = .375). CONCLUSIONS: Abnormalities in contractile integral of the postpeak phase are more significant in JH with higher dysphagia scores Although the total postpeak contractile integral was higher in symptomatic patients, this was associated with longer duration of postpeak activity suggesting that dysphagia patients with JH have a defect in the postpeak phase of peristalsis.

The relationship between esophageal acid exposure and the esophageal response to volumetric distention.

BACKGROUND: Increased esophagogastric junction (EGJ) distensibility is thought to contribute to gastroesophageal reflux disease (GERD). Using the functional lumen imaging probe (FLIP), we aimed to assess the esophageal response to distension among patients undergoing esophageal pH monitoring. METHODS: 25 patients (ages 22-73; 13 females) who underwent ambulatory wireless esophageal pH testing while off proton-pump inhibitors were evaluated with FLIP during sedated upper endoscopy. Esophageal reflux was quantified by total percent acid exposure time (AET; <6% was considered normal). FLIP studies were analyzed using a customized program generate FLIP topography plots to identify esophageal contractility patterns and to calculate the EGJ-distensibility index (DI). Reflux symptoms were assessed with the GERDQ. Values reflect median (interquartile range). RESULTS: Among all patients, the AET was 7.2% (3.7-11.1) and EGJ-DI was 4.2 (2.5-7.6) mm2 /mm Hg. Repetitive antegrade contractions (RACs) were induced in 19/25 (76%) of patients; AET was lower among patients with (6.1%, 3-7.8) than without (14.9, 8.5-22.3) RACs (P = .009). Correlation was weak and insignificant between AET and EGJ-DI, GERDQ and AET, and GERDQ and EGJ-DI. Patients with abnormal AET (n = 16) and normal AET (n = 9) had similar EGJ-DI, 4.6 mm2 /mm Hg (2.9-9.2) vs 3.2 (2.2-5.1), P = .207 and GERDQ, P = .138. CONCLUSIONS: Abnormal esophageal acid exposure was associated with an impaired contractile response to volume distention of the esophagus. This supports that acid exposure is dependent on acid clearance mechanisms.

Abnormal esophageal acid exposure on high-dose proton pump inhibitor therapy is common in systemic sclerosis patients.

BACKGROUND: Esophageal dysfunction and gastro-esophageal reflux disease (GERD) are common among patients with systemic sclerosis (SSc). Although high-dose proton pump inhibitors (PPIs) typically normalize esophageal acid exposure, the effectiveness of PPI therapy has not been systematically studied in SSc patients. The aim of this study was to characterize reflux in SSc patients on high-dose PPI using esophageal pH-impedance testing. METHODS: In this case-controlled retrospective analysis, 38 patients fulfilling 2013 American College of Rheumatology SSc criteria who underwent esophageal pH-impedance testing on twice-daily PPI between January 2014 and March 2017 at a tertiary referral center were compared with a control-cohort of 38 non-SSc patients matched for PPI formulation and dose, hiatal hernia size, age, and gender. Patient clinical characteristics, including endoscopy and high-resolution manometry findings, were assessed via chart review. KEY RESULTS: On pH-impedance, SSc patients had higher acid exposure times (AETs) than controls. Sixty-one percent of the SSc patients and 18% of the control patients had a total AET ≥4.5% (P < .001). Systemic sclerosis patients also had significantly longer AETs, longer median bolus clearance, and lower nocturnal impedance values. CONCLUSIONS & INFERENCES: Abnormal esophageal acid exposure despite high-dose PPI therapy was common among patients with SSc. The lack of increased reflux episodes in the SSc patients, and longer bolus clearance times and lower nocturnal impedance, supports ineffective clearance as the potential mechanism. Systemic sclerosis patients may require adjunctive therapies to PPIs to control acid reflux.

Assessing the pre- and postpeak phases in a swallow using esophageal pressure topography.

BACKGROUND: The current paradigm of measuring esophageal contractile vigor assesses the entirety of a pressure wave using a single measurement, the distal contractile integral (DCI). We hypothesize that an assessment identifying separate phases of the contractile pressure wave before and after the pressure peak may help distinguish abnormalities in patients presenting with chest pain and dysphagia. The aim of the present study was to develop a technique to assess the individual phases and report on the values in healthy controls. METHODS: Seventy-one healthy controls were enrolled. High-resolution manometry studies of five intact liquid swallows in both supine and upright positions were analyzed using a customized MATLAB program to divide swallows into a prepeak phase and postpeak phase, and compute the contractile integral of both phases. The contractile integrals were also controlled by duration over each phase. KEY RESULTS: The composite DCI measurement in healthy controls appears to be weighted toward slightly higher contractile activity during postpeak phase based on postpeak to prepeak ratios in both the supine and upright position (1.50 and 1.49, respectively). The contribution of postpeak phase on the composite DCI was weakened when controlled by time (0.92 and 0.96 in both supine and upright position, respectively). CONCLUSIONS AND INFERENCES: We developed a novel measurement focused on separating the prepeak and postpeak components of the peristaltic contractile activity during swallowing. Using this technique, it appears that overall contractile activity is higher during postpeak phase and this is related to the longer time component during this phase.

High-resolution impedance manometry parameters enhance the esophageal motility evaluation in non-obstructive dysphagia patients without a major Chicago Classification motility disorder.

BACKGROUND: High-resolution impedance manometry (HRIM) allows evaluation of esophageal bolus retention, flow, and pressurization. We aimed to perform a collaborative analysis of HRIM metrics to evaluate patients with non-obstructive dysphagia. METHODS: Fourteen asymptomatic controls (58% female; ages 20-50) and 41 patients (63% female; ages 24-82), 18 evaluated for dysphagia and 23 for reflux (non-dysphagia patients), with esophageal motility diagnoses of normal motility or ineffective esophageal motility, were evaluated with HRIM and a global dysphagia symptom score (Brief Esophageal Dysphagia Questionnaire). HRIM was analyzed to assess Chicago Classification metrics, automated pressure-flow metrics, the esophageal impedance integral (EII) ratio, and the bolus flow time (BFT). KEY RESULTS: Significant symptom-metric correlations were detected only with basal EGJ pressure, EII ratio, and BFT. The EII ratio, BFT, and impedance ratio differed between controls and dysphagia patients, while the EII ratio in the upright position was the only measure that differentiated dysphagia from non-dysphagia patients. CONCLUSIONS & INFERENCES: The EII ratio and BFT appear to offer an improved diagnostic evaluation in patients with non-obstructive dysphagia without a major esophageal motility disorder. Bolus retention as measured with the EII ratio appears to carry the strongest association with dysphagia, and thus may aid in the characterization of symptomatic patients with otherwise normal manometry.

Editorial: Reflux While Running: Something to Belch About.

Running is the most popular form of exercise in the United States. Gastroesophageal reflux (GER) is common during exercise and may affect performance. Previous studies have focused on increased intra-abdominal pressure as a major determinant of acid reflux during physical exertion. In this issue, Herregods et al. examined the mechanisms of GER in healthy volunteers using simultaneous high-resolution manometry and pH impedance testing performed while running. Novel observations afforded by the utilization of state-of-the-art technology include the importance of transient lower esophageal sphincter relaxation ("belch reflex") and transient formation of hiatal hernia during exercise. The findings are provocative and lend credence to commonsense strategies to minimize the consequences of belching in runners.

Evaluation of esophageal distensibility in eosinophilic esophagitis: an update and comparison of functional lumen imaging probe analytic methods.

BACKGROUND: Distensibility evaluation of the esophageal body using the functional lumen imaging probe (FLIP) offers an objective measure to characterize patients with eosinophilic esophagitis (EoE), though this analysis may be limited by unrecognized catheter movement and esophageal contractility. The aims of this study were to report novel FLIP analytic methods of esophageal distensibility measurement in EoE and to assess the effect of contractility. METHODS: Nine healthy controls (six female; ages 20-49) and 20 EoE patients (four female; ages 19-64; grouped by degree of distension-mediated contractility identified on FLIP) were evaluated with a 16-cm FLIP device during step-wise balloon distension during upper endoscopy. A distensibility plateau (DP) was generated using multiple methods to identify the narrowest esophageal body diameter: (i) wavelet decomposition (WD), (ii) maximal diameter (MD), and (iii) FLIP Analytics software. KEY RESULTS: Distensibility was reduced in EoE patients compared with controls using the WD (p = 0.002) and MD (p = 0.001) methods; a trend was detected using the FLIP Analytics method (p = 0.055). Significant intra-subject differences were detected between methods among both patients and controls (p-values <0.001 to 0.025); the difference was more pronounced among subjects with a greater degree of contractility. DP was <19 mm among 7/9 controls with FLIP Analytics, 6/9 controls with WD, and 0/9 controls using the MD method. CONCLUSIONS & INFERENCES: Distension-mediated contractility affects distensibility measurement with the FLIP. Using software-based algorithms, particularly with a method that identifies the maximal-achieved diameters (MD), may improve objective distensibility measurement for clinical research and practice.

The association between systemic sclerosis disease manifestations and esophageal high-resolution manometry parameters.

BACKGROUND: We aimed to evaluate the associations between systemic sclerosis (SSc)-related systemic manifestations and esophageal function using high-resolution manometry (HRM). METHODS: Patients with SSc that had undergone HRM between 1/2004 and 9/2014 were identified and HRMs were analyzed according to the Chicago Classification. Clinical characteristics were identified via retrospective chart review and compared among motility diagnoses while adjusting for age, gender, race, and SSc-disease duration. KEY RESULTS: Seventy-nine patients (85% female, ages 25-77) were included. Clinical characteristics were compared between patients with absent contractility (AC, n = 40), ineffective esophageal motility (IEM; n = 15), and normal motility (n = 19); the five remaining patients met criteria for other motility diagnoses. Groups differed in severity of skin involvement measured by the modified Rodnan skin score (0-51): AC (adjusted mean 12.6), IEM (4.4), normal (4.3), p = 0.043. Pulmonary function tests [percent predicted FVC and DLCO) were lower in AC (adjusted mean, FVC: 70.3, DLCO 51.1), than IEM (FVC: 92.0; DLCO: 76.9) and normal motility (FVC: 80.0; DLCO: 67.2), p values 0.057 (FVC) and 0.007 (DLCO). Groups did not differ by SSc-disease duration, autoantibodies, or reported symptoms of dysphagia or reflux. CONCLUSIONS & INFERENCES: In patients with SSc, absent esophageal contractility on HRM was associated with increased skin disease severity and worse lung function. Obtaining HRM to identify SSc patients with more severe esophageal dysfunction could be considered to enable implementation of management strategies in patients potentially at risk for increased morbidity and mortality.

Esophageal diverticula are associated with propagating peristalsis: a study utilizing high-resolution manometry.

BACKGROUND: Esophageal diverticula have been associated with esophageal motility disorders, most commonly achalasia. We aimed to evaluate high-resolution manometry (HRM) motility diagnoses and pressurization patterns in patients with esophageal diverticula. METHODS: Patients were retrospectively identified for distal esophageal diverticula and previously completed HRM. High-resolution manometries were analyzed according to the Chicago Classification, and the pressure slope of the compartmentalization phase (time between upper esophageal sphincter closure and the transition zone) of esophageal bolus transit was measured. Pressure slopes were also measured in 10 asymptomatic volunteers (controls) for comparison. KEY RESULTS: Nineteen patients (ages 31-83) were included. Eight (42%) patients had normal motility, five (26%) had esophagogastric junction outflow obstruction, and two (11%) had jackhammer esophagus; four patients had other motility diagnoses including only one patient with achalasia. A total of six patients (32%) had at least one hypercontractile swallow. Greater compartmentalization phase pressure slopes were observed in patients at the mid-esophageal body in both supine (median [interquartile range]: 1.9 mmHg/s [0.9, 3.6]) and upright (1.1 [0.1, 3.1]) positions than in controls (supine: -1.3 [-2.4, -0.11], p = 0.001; upright; -0.71 [-2.1, -0.02], p = 0.005). CONCLUSIONS & INFERENCES: Propagating peristalsis, often with hypercontractility, was commonly seen in our cohort of patients with esophageal diverticula. Abnormal compartmentalization phase pressurization may indicate a relationship of abnormal esophageal wall mechanics and/or compliance with diverticula; however whether these findings are causal or reactionary remains unclear.

High-resolution impedance manometry measurement of bolus flow time in achalasia and its correlation with dysphagia.

BACKGROUND: We assessed whether a high-resolution impedance manometry (HRIM) metric, bolus flow time (BFT) across the esophagogastric junction (EGJ), was abnormal in achalasia patients subtyped by the Chicago Classification and compared BFT to other HRM metrics. METHODS: HRIM studies were performed in 60 achalasia patients (14 type I, 36 type II and 10 type III) and 15 healthy controls. Studies were analyzed with a MATLAB program to calculate BFT using a virtual HRIM sleeve. Integrated relaxation pressure (IRP) and basal end-expiratory EGJ pressure were also calculated. The relationship between BFT and dysphagia symptom scores was assessed using the impaction dysphagia questionnaire (IDQ). KEY RESULTS: Median BFT was significantly lower in achalasia patients (0.5 s, range 0.0-3.5 s) compared to controls (3.5 s, range 2.0-5.0 s; p < 0.05). BFT was significantly lower in types I and II than in type III achalasia in both the supine and upright positions (p < 0.0001). BFT was the only HRIM metric significantly associated with IDQ score in both the supine (R(2)  = 0.20, p = 0.0046) and upright positions (R(2)  = 0.27, p = 0.0002). CONCLUSIONS & INFERENCES: BFT was significantly reduced in all subtypes of achalasia and complementary to the IRP as a diagnostic discriminant in equivocal achalasia cases. Additionally, BFT had a more robust correlation with dysphagia severity compared to other metrics of EGJ function.

Utilizing functional lumen imaging probe topography to evaluate esophageal contractility during volumetric distention: a pilot study.

BACKGROUND: The functional lumen imaging probe (FLIP) measures luminal cross-sectional area and pressure during volumetric distension. By applying novel customized software to produce FLIP topography plots, organized esophageal contractility can be visualized and analyzed. We aimed to describe the stimulus thresholds and contractile characteristics for distension-induced esophageal body contractility using FLIP topography in normal controls. METHODS: Ten healthy controls were evaluated during endoscopy with FLIP. During stepwise bag distension, simultaneous intra-bag pressure and luminal diameter measurements were obtained and exported to a MatLab program to generate FLIP topography plots. The distension volume, intra-bag pressure, and maximum esophageal body diameters were measured for the onset and cessation of repetitive antegrade contractions (RACs). Contraction duration, interval, magnitude, and velocity were measured at 8 and 3-cm proximal to the esophagogastric junction. KEY RESULTS: Eight of ten subjects demonstrated RACs at a median onset volume of 29 mL (IQR: 25-38.8), median intra-bag pressure of 10.7 mmHg (IQR: 8.6-15.9), and median maximum esophageal body diameter of 18.5 mm (IQR: 17.5-19.6). Cessation of RACs occurred prior to completion of the distension protocol in three of the eight subjects exhibiting RACs. Values of the RAC-associated contractile metrics were also generated to characterize these events. CONCLUSIONS & INFERENCES: Distension-induced esophageal contractions can be assessed utilizing FLIP topography. RACs are a common finding in asymptomatic controls in response to volume distention and have similar characteristics to secondary peristalsis and repetitive rapid swallows.

Influence of exogenous gonadotropin-releasing hormone on seasonal reproductive behavior of the coyote (Canis latrans).

Wild Canis species such as the coyote (C. latrans) express a suite of reproductive traits unusual among mammals, including perennial pair-bonds and paternal care of the young. Coyotes also are monestrous, and both sexes are fertile only in winter; thus, they depend upon social and physiologic synchrony for successful reproduction. To investigate the mutability of seasonal reproduction in coyotes, we attempted to evoke an out-of-season estrus in October using one of two short-acting gonadotropin-releasing hormone (GnRH) agents: (1) a GnRH analogue, deslorelin (6-D-tryptophan-9-(N-ethyl-L-prolinamide)-10-deglycinamide), 2.1mg pellet sc; or (2) gonadorelin, a GnRH (5-oxoPro-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-GlyNH(2)) porcine hypothalamic extract, 2.0 microg/kg im once daily for 3 consecutive days. A transient increase in serum concentrations of estradiol and progesterone (1 and 2 wk, respectively) was detected after treatment with deslorelin but not gonadorelin. Also, socio-sexual behaviors reminiscent of winter mating (including courtship, mate-guarding, precoital mounts, and copulatory ties) were observed among the deslorelin group. During the subsequent breeding season (January and February), however, preovulatory courtship behavior and olfactory sampling appeared suppressed; emergence of mounts and copulations were delayed in both deslorelin and gonadorelin treatment groups. Furthermore, whereas 8 of 12 females treated in October ovulated and produced healthy litters in the spring, 4 naïve coyotes failed to copulate or become pregnant. Thus, perturbation of hormones prior to ovulation in species with complex mating behaviors may disrupt critical intrapair relationships, even if fertility is not impaired physiologically.

Determination by HPLC fluorescence analysis of the natural enantiomers of sex pheromones in the New World screwworm fly, Cochliomyia hominivorax.

Bioassays of six racemic synthesized candidate sex pheromone compounds against male New World screwworm Cochliomyia hominivorax (Coquerel) flies showed that the most potent bioactivity was found with 6-acetoxy-19-methylnonacosane and 7-acetoxy-15-methylnonacosane compared with four other isomeric acetoxy nonacosanes and a larger aliphatic ketone. As all these methyl-branched compounds have two asymmetric carbons and four possible enantiomers, characterization of the natural enantiomers was essential. All four enantiomers for the two most bioactive isomers of the natural sex pheromone were synthesized for bioassay. Hydrolysis and derivatization of these enantiomers with different fluorescent reagents was followed by column-switched high-performance liquid chromatography. The use of two linked, reversed-phase columns of different polarity held at sub-ambient temperatures allowed good separation of each enantiomer. This analysis applied to natural material was successful, as (6R,19R)-6-acetoxy-19-methylnonanocosane, and (7R,15R)- and (7R,15S)-7-acetoxy-15-methylnonanocosane were detected in extracts of recently colonized female flies.