Clinical Features and Treatment Response to Topical Steroids in Ethnic and Racial Minority Patients With Eosinophilic Esophagitis.

INTRODUCTION: Differences in eosinophilic esophagitis (EoE) presentation and outcomes by ethnicity or race remain understudied. We aimed to determine whether EoE patients of Hispanic/Latinx ethnicity or non-White race have differences in presentation at diagnosis or response to topical corticosteroid (tCS) treatment. METHODS: This retrospective cohort study included subjects of any age with a new diagnosis of EoE and documentation of ethnicity or race. For those who had treatment with tCS and follow-up endoscopy/biopsy, we assessed histologic response (<15 eosinophils/hpf), global symptom response, and endoscopic response. Hispanic EoE patients were compared with non-Hispanics at baseline and before and after treatment. The same analyses were repeated for White vs non-Whites. RESULTS: Of 1,026 EoE patients with ethnicity data, just 23 (2%) were Hispanic. Most clinical features at presentation were similar to non-Hispanic EoE patients but histologic response to tCS was numerically lower (38% vs 57%). Non-White EoE patients (13%) were younger at diagnosis and had less insurance, lower zip code-level income, shorter symptom duration, more vomiting, less dysphagia and food impaction, fewer typical endoscopic features, and less dilation. Of 475 patients with race data treated with tCS, non-Whites had a significantly lower histologic response rate (41% vs 59%; P = 0.01), and odds of histologic response remained lower after controlling for potential confounders (adjusted odds ratio 0.40, 95% confidence intervals: 0.19-0.87). DISCUSSION: Few EoE patients at our center were Hispanic, and they had similar clinical presentations as non-Hispanics. The non-White EoE group was larger, and presentation was less dysphagia-specific. Non-White patients were also less than half as likely to respond to tCS.

Real-World Efficacy of Dupilumab in Severe, Treatment-Refractory, and Fibrostenotic Patients With Eosinophilic Esophagitis.

BACKGROUND & AIMS: Dupilumab is approved for treatment of eosinophilic esophagitis (EoE), but real-world data are lacking. We aimed to determine the real-world efficacy of dupilumab in patients with severe, treatment-refractory, and fibrostenotic EoE. METHODS: We conducted a retrospective cohort study of EoE patients prescribed dupilumab and who were treatment-refractory to standard modalities. Patient demographics, clinical characteristics, EoE history, and procedural data (including the histologically worst, predupilumab, and postdupilumab endoscopies) were extracted from medical records. Symptomatic, endoscopic, and histologic responses were assessed for the worst and predupilumab endoscopies compared with the postdupilumab endoscopy. RESULTS: We identified 46 patients with refractory fibrostenotic EoE who were treated with dupilumab. Patients showed endoscopic, histologic, and symptomatic improvement on dupilumab compared with both the worst and the predupilumab esophagogastroduodenoscopies. The peak eosinophil counts decreased markedly, and postdupilumab histologic response rates were 80% and 57% for fewer than 15 eosinophils per high-power field and 6 or fewer eosinophils per high-power field, respectively, and the Endoscopic Reference Score decreased from 5.01 to 1.89 (P < .001 for all). Although the proportion of strictures was stable, there was a significant increase in the predilation esophageal diameter (from 13.9 to 16.0 mm; P < .001). Global symptom improvement was reported in 91% (P < .001). CONCLUSIONS: In this population of severe, refractory, and fibrostenotic EoE patients, most achieved histologic, endoscopic, and symptom improvement with a median of 6 months of dupilumab, and esophageal stricture diameter improved. Dupilumab has real-world efficacy for a severe EoE population, most of whom would not have qualified for prior clinical trials.

Increasing Age at the Time of Diagnosis and Evolving Phenotypes of Eosinophilic Esophagitis Over 20 Years.

BACKGROUND: The presentation of eosinophilic esophagitis (EoE) is heterogeneous, but trends over time are not known. AIM: To determine whether clinical and endoscopic phenotypes at EoE diagnosis have changed over the past 2 decades. METHODS: In this retrospective cohort study, adults and children with newly diagnosed EoE were phenotyped as follows: (1) inflammatory vs fibrostenotic vs mixed on endoscopy; (2) atopic vs non-atopic; (3) age at symptom onset; (4) age at diagnosis; (5) presence of autoimmune or connective tissue disease; and (6) responsive to steroids. The prevalence of different phenotypes was categorized by 5-year intervals. Multivariate analysis was performed to assess for changes in patient features over time. RESULTS: Of 1187 EoE patients, age at diagnosis increased over time (from 22.0 years in 2002-2006 to 31.8 years in 2017-2021; p < 0.001) as did the frequency of dysphagia (67% to 92%; p < 0.001). Endoscopic phenotypes were increasingly mixed (26% vs 68%; p < 0.001) and an increasing proportion of patients had later onset of EoE. However, there were no significant trends for concomitant autoimmune/connective tissue disease or steroid responder phenotypes. On multivariate analysis, after accounting for age, dysphagia, and food impaction, the increase in the mixed endoscopic phenotype persisted (aOR 1.51 per each 5-year interval, 95% CI 1.31-1.73). CONCLUSION: EoE phenotypes have changed over the past two decades, with increasing age at diagnosis and age at symptom onset. The mixed endoscopic phenotype also increased, even after controlling for age and symptomatology. Whether this reflects changes in provider recognition or disease pathophysiology is yet to be elucidated.

Bringing an end to diabetes stigma and discrimination: an international consensus statement on evidence and recommendations.

People with diabetes often encounter stigma (ie, negative social judgments, stereotypes, prejudice), which can adversely affect emotional, mental, and physical health; self-care, access to optimal health care; and social and professional opportunities. To accelerate an end to diabetes stigma and discrimination, an international multidisciplinary expert panel (n=51 members, from 18 countries) conducted rapid reviews and participated in a three-round Delphi survey process. We achieved consensus on 25 statements of evidence and 24 statements of recommendations. The consensus is that diabetes stigma is driven primarily by blame, perceptions of burden or sickness, invisibility, and fear or disgust. On average, four in five adults with diabetes experience diabetes stigma and one in five experience discrimination (ie, unfair and prejudicial treatment) due to diabetes, such as in health care, education, and employment. Diabetes stigma and discrimination are harmful, unacceptable, unethical, and counterproductive. Collective leadership is needed to proactively challenge, and bring an end to, diabetes stigma and discrimination. Consequently, we achieved unanimous consensus on a pledge to end diabetes stigma and discrimination.

Feeding Tube Placement, Complications, and Treatment Responses in a Large Eosinophilic Esophagitis Patient Population.

OBJECTIVES: Feeding tubes can provide a temporary or long-term solution for nutritional therapy. Little is known regarding the use of feeding tubes in patients with eosinophilic esophagitis (EoE). We sought to describe the characteristics and outcomes in EoE patients requiring tube feeding. METHODS: This was a retrospective cohort study of EoE patients at a large tertiary care health system. Demographics, clinical characteristics, and endoscopic findings were extracted from medical records, and patients who had a feeding tube were identified. Patients with and without a feeding tube were compared. Details about the tube, complications, and treatment were extracted. Growth, global symptomatic, endoscopic, and histopathologic (<15 eos/hpf) responses were compared before and after the initiation of feeding tube therapy. RESULTS: We identified 39 of 1216 EoE patients who had a feeding tube (3%). Feeding tube patients were younger (mean age 6.3 years), reported more vomiting, and had a lower total endoscopic reference score than non-feeding tube patients ( P < 0.01 for all). Tubes were used for therapy for an average of 6.8 years, with most patients (95%) receiving both pharmacologic and formula treatment for EoE. An emergency department visit for a tube complication was required in 26%. Tube feeding improved body mass index z score ( P < 0.01), symptomatic response (42%), endoscopic response (53%), and histologic response (71%). CONCLUSIONS: Among EoE patients, only a small subset required a feeding tube and predominantly were young children with failure to thrive. Feeding tubes significantly improved growth and, when used in combination with other treatments, led to reduced esophageal eosinophilic inflammation.

Eosinophilic esophagitis patients with multiple atopic conditions: Clinical characteristics and treatment response to topical steroids.

BACKGROUND: Patients with eosinophilic esophagitis (EoE) typically have concomitant atopic conditions, but whether there are differences in presentation or treatment response by the number of atopic diseases is unknown. OBJECTIVE: To determine whether patients with EoE having multiple atopic conditions have differences in presentation or response to topical corticosteroid (TCS) treatment. METHODS: We performed a retrospective cohort study of adults and children with newly diagnosed EoE. The total number of atopic comorbidities (allergic rhinitis, asthma, eczema, food allergy) was calculated. Patients with at least 2 atopic conditions other than allergic rhinitis were defined as having multiple atopic conditions and their baseline characteristics were compared with those with less than 2 atopic conditions. Histologic, symptom, and endoscopic responses to TCS treatment were also compared with bivariable and multivariable analyses. RESULTS: Of the 1020 patients with EoE having atopic disease information, 235 (23%) had 1 atopic comorbidity, 211 (21%) had 2, 113 (11%) had 3, and 34 (3%) had 4. At baseline, the 180 (18%) patients with 2 or more atopic diseases were younger and had more vomiting, less abdominal pain, more exudates and edema on endoscopy, and higher peak eosinophil counts. Among those treated with TCS, there was a trend toward better global symptom response in patients with less than 2 atopic conditions, but there was no difference in histologic or endoscopic response compared with those with 2 or more atopic conditions. CONCLUSION: There were differences in the initial presentation of EoE between those with and without multiple atopic conditions, but there were no major differences in histologic treatment response to corticosteroids by atopic status.

Time Course Evaluation of Mitogen-Activated Protein Kinase Phosphorylation to Resistance Exercise: A Systematic Review.

ABSTRACT: Lee, CJ and Nicoll, JX. Time course evaluation of mitogen-activated protein kinase phosphorylation to resistance exercise: a systematic review. J Strength Cond Res 37(3): 710-725, 2023-Resistance exercise (RE) can increase the signaling activities of mitogen-activated protein kinases (MAPKs), specifically extracellular signal-regulated kinases 1/2 (ERK1/2), p90 ribosomal S6 kinases (p90RSK), c-Jun NH2-terminal kinases (JNK), and p38-MAPK. These RE-induced responses contribute to various intracellular processes modulating growth and development in skeletal muscles, playing an essential role in resistance training adaptations. The time course of MAPK phosphorylation to different RE conditions, such as training experience and varying loads, remains ambiguous. A systematic review was conducted to determine the effects of different post-RE recovery time points on the MAPK signaling cascade. In addition, the effects of loading and training statuses on MAPK responses were also investigated. The review was performed according to the preferred reporting items for systematic reviews and meta-analyses guidelines with a literature search incorporating 3 electronic databases. A modified version of the Downs and Black checklist was used to evaluate the methodological quality of the studies. The signaling responses were measured within a time range between immediately post-RE and >6 hours post-RE. Forty-four studies met the inclusion criteria, and all were classified as good-to-moderate methodological quality. Mitogen-activated protein kinase phosphorylation increased to different levels after RE, with the highest near the cessation of exercise. Although overall signaling was attenuated among trained individuals likely because of training adaptations, greater MAPK responses can be attributed to moderate loads of 65-85% 1RM regardless of the training experience. However, specific training-induced responses remain equivocal, and further investigations are required to determine the ideal training parameters to optimize anabolic intramuscular signaling, which may likely optimize resistance training adaptations.

Impact of changing diagnostic criteria on the diagnosis of serrated polyposis syndrome.

Background and study aims The World Health Organization criteria for serrated polyposis syndrome (SPS) were established in 2010 and modified in 2019. Neither set of criteria have been validated against genetic markers or proven to be the optimal criteria for defining colorectal cancer risk in patients with serrated colorectal lesions. In this study, we sought to gain insight into how frequently the change in SPS criteria in 2019 impacted the diagnosis of SPS. Patients and methods We reviewed 279 patients with SPS diagnosed between 2010 and 2019 using the 2010 criteria (n = 163) or since 2019 using the 2019 criteria (n = 116). We reviewed whether patients in each group met the diagnosis of SPS by the alternative criteria. Results Of those diagnosed using 2010 criteria, 5.5 % did not meet 2019 criteria. Of those diagnosed by 2019 criteria, 10.3 % did not meet 2010 criteria. Conclusions Most patients with SPS in our database met the diagnosis of SPS by both 2010 and 2019 criteria, with only 5 % to 10 % of patients in each cohort not meeting the alternative diagnostic criteria.

Food Allergies and Alpha-gal Syndrome for the Gastroenterologist.

PURPOSE OF REVIEW: Food allergies are typically not considered as a cause of gastrointestinal (GI) distress without additional allergic symptoms, apart from celiac disease and eosinophilic esophagitis. However, recent reports of patients with alpha-gal syndrome who presented with GI-only symptoms like abdominal pain, vomiting, and diarrhea challenge this paradigm. Alpha-gal syndrome is an IgE-mediated allergy characterized by delayed reactions after eating mammalian meat or mammalian-derived products that contain galactose-alpha-1,3-galactose (alpha-gal). The purpose of this review is to discuss our current understanding of food allergies, GI illness, and the GI manifestations of alpha-gal syndrome. RECENT FINDINGS: Among Southeastern U.S. GI clinic patients who screened positive for serum alpha-gal IgE, a majority of patients reported significant symptom improvement on an alpha-gal-avoidant diet, suggesting that the allergy had played a role in their GI symptoms. Diagnosis of alpha-gal syndrome is typically made with concerning allergic symptoms, elevated alpha-gal specific IgE in the serum, and symptom improvement on an alpha-gal avoidant diet. Alpha-gal syndrome can cause a delayed allergic response that is increasingly recognized worldwide, including among patients with predominant GI symptoms.

Higher Body Mass Index Is Associated With Decreased Treatment Response to Topical Steroids in Eosinophilic Esophagitis.

BACKGROUND & AIMS: Understanding which eosinophilic esophagitis (EoE) patients will respond to treatment with topical corticosteroids (tCS) remains challenging, and it is unknown whether obesity impacts treatment response. This study aimed to determine whether treatment outcomes to tCS in EoE patients vary by body mass index (BMI). METHODS: This retrospective cohort study of the University of North Carolina EoE Clinicopathologic database assessed subjects age 14 years or older with a new diagnosis of EoE. Their BMI was calculated and histologic, symptom, and endoscopic responses were recorded after tCS treatment. The treatment response of obese (BMI, ≥30 kg/m2) and nonobese EoE status was compared using bivariate and multivariate analyses. RESULTS: We identified 296 EoE patients treated with tCS. Baseline characteristics were similar, although obese EoE patients had more heartburn and hiatal hernias. Histologic response was higher for those who were nonobese compared with obese at fewer than 15 (61% vs 47%; P = .049) and 6 or fewer (54% vs 38%; P = .02) eosinophils per high-power field, respectively. In addition, nonobese patients had significantly greater endoscopic and symptomatic responses. On multivariate analysis, increasing BMI was associated independently with decreased histologic response after accounting for age, heartburn, dilation, and hiatal hernia whether BMI was assessed as a continuous variable (adjusted odds ratio [aOR], 0.93; 95% CI, 0.89-0.98), as nonobese vs obese (aOR, 0.38; 95% CI, 0.21-0.68), or in 4 categories (overweight vs normal [aOR, 0.46; 95% CI, 0.26-0.84] or obese vs normal [aOR, 0.26; 95% CI, 0.13-0.51]). CONCLUSIONS: As BMI increases in EoE patients, the odds of histologic, symptomatic, and endoscopic responses to tCS decreases, with obese patients having an approximately 40% decrease in odds of response.

Metastatic Cancer of Apparent Colon Origin With No Intraluminal Cancer After Resection of Colorectal Lateral Spreading Lesions.

We report a case of metastatic adenocarcinoma to the liver that presented 5 months after piecemeal endoscopic mucosal resection of 3 benign lateral spreading adenomas in the cecum. The pathologic features of the metastatic cancer indicated a probable colonic origin. However, when the cancer was identified, there was no endoscopic evidence of recurrent polyp or another primary lesion in the colon.

Association of Clear Cell Likelihood Score on MRI and Growth Kinetics of Small Solid Renal Masses on Active Surveillance.

BACKGROUND. The lack of validated imaging markers to characterize biologic aggressiveness of small renal masses (SRMs)-defined as those categorized as cT1a and 4 cm and smaller-hinders medical decision-making among available initial management strategies. OBJECTIVE. The purpose of this article was to explore the association of the clear cell likelihood score (ccLS) on MRI with growth rates and progression of SRMs. METHODS. This retrospective study included consecutive SRMs assigned a ccLS on clinical MRI examinations performed between June 2016 and November 2019 at an academic tertiary-care medical center or its affiliated safety net hospital system. The ccLS reports the likelihood that the SRM represents clear cell renal cell carcinoma (ccRCC) from 1 (very unlikely) to 5 (very likely). The ccLS was extracted from clinical reports. Tumor size measurements were extracted from available prior and follow-up cross-sectional imaging examinations, through June 2020. Serial tumor size measurements were fit to linear and exponential growth curves. Estimated growth rates were grouped by the assigned ccLS. Tumor progression was defined by development of large size (> 4 cm in at least two consecutive measurements) and/or rapid growth (doubling of volume within 1 year). Differences among ccLS groups were evaluated using Kruskal-Wallis tests. Correlations between ccLS and growth rate were evaluated by Spearman correlation (ρ). RESULTS. Growth rates of 386 SRMs (100 ccLS 1-2, 75 ccLS 3, and 211 ccLS 4-5) from 339 patients (median age, 65 years; 198 men, 141 women) were analyzed. Median follow-up was 1.2 years. The ccLS was correlated with growth rates by size (ρ = 0.19; p < .001; ccLS 4-5, 9%/year; ccLS 1-2, 5%/year; p < .001) and by volume (ρ = 0.14; p = .006; ccLS 4-5, 29%/year; ccLS 1-2, 16%/year; p < .001). Disease progression (observed in 49 SRMs) was not significantly associated with ccLS group (p = .61). Two patients (0.6%) developed metastases during active surveillance: one ccLS 1 was a type 2 papillary renal cell carcinoma and one ccLS 4 was ccRCC. CONCLUSION. Growth is associated with ccLS in SRMs, with higher ccLS correlating with faster growth. CLINICAL IMPACT. SRMs with lower ccLS may be considered for active surveillance, whereas SRMs with higher ccLS may warrant earlier intervention. The noninvasive ccLS derived from MRI correlates with growth rate of SRMs and may help guide personalized management.

Yield of a second right colon examination during colonoscopy after a first examination using a mucosal exposure device.

BACKGROUND AND AIMS: Double right colon examination during colonoscopy has been advocated to reduce the risk of interval cancer in the right colon. Whether 2 examinations are necessary when the first examination is performed with a mucosal exposure device is uncertain. We documented the rates of missed adenomas, sessile serrated lesions, and hyperplastic polyps after an initial right colon examination by a high-level detector using a mucosal exposure device. METHODS: At a single tertiary hospital outpatient practice, we prospectively collected data on the yield of a second examination of the right colon after an initial examination by a single high-detecting colonoscopist using a mucosal exposure device. RESULTS: During the study period, 1331 eligible consecutive patients underwent colonoscopy. Right colon adenoma, sessile serrated lesion, and hyperplastic polyp miss rates were 15.8%, 14.1%, and 16.7%, respectively. Four percent of patients had adenomas detected in the right colon only with a second examination. CONCLUSIONS: A second examination of the right colon is warranted, even when using a distal mucosal exposure device to perform colonoscopy.

Kinetics and selectivity of methane oxidation on an IrO2(110) film.

Undercoordinated, bridging O-atoms (Obr) are highly active as H-acceptors in alkane dehydrogenation on IrO2(110) surfaces but transform to HObrgroups that are inactive toward hydrocarbons. The low C-H activity and high stability of the HObrgroups cause the kinetics and product selectivity during CH4oxidation on IrO2(110) to depend sensitively on the availability of Obratoms prior to the onset of product desorption. From temperature programmed reaction spectroscopy (TPRS) and kinetic simulations, we identified two Obr-coverage regimes that distinguish the kinetics and product formation during CH4oxidation on IrO2(110). Under excess Obrconditions, when the initial Obrcoverage is greater than that needed to oxidize all the CH4to CO2and HObrgroups, complete CH4oxidation is dominant and produces CO2in a single TPRS peak between 450 and 500 K. However, under Obr-limited conditions, nearly all the initial Obratoms are deactivated by conversion to HObror abstracted after only a fraction of the initially adsorbed CH4oxidizes to CO2and CO below 500 K. Thereafter, some of the excess CHxgroups abstract H and desorb as CH4above ∼500 K while the remainder oxidize to CO2and CO at a rate that is controlled by the rate at which Obratoms are regenerated from HObrduring the formation of CH4and H2O products. We also show that chemisorbed O-atoms ('on-top O') on IrO2(110) enhance CO2production below 500 K by efficiently abstracting H from Obratoms and thereby increasing the coverage of Obratoms available to completely oxidize CHxgroups at low temperature. Our results provide new insights for understanding factors which govern the kinetics and selectivity during CH4oxidation on IrO2(110) surfaces.

Colorectal EMR outcomes in octogenarians versus younger patients referred for removal of large (≥20 mm) nonpedunculated polyps.

BACKGROUND AND AIMS: Data are limited on safety and outcomes of colorectal EMR in octogenarians (≥80 years old). We sought to review outcome data for patients aged ≥80 in a prospectively collected database of patients referred for large polyp removal. METHODS: We retrospectively evaluated a database of patients referred for large (≥20 mm) nonpedunculated polyp removal. From 2000 to 2019, we compared the rates of follow-up, recurrence, adverse events, and synchronous neoplasia detection between younger patients and patients aged ≥80. RESULTS: There were 167 patients aged ≥80 years and 1686 <80 years. Patients in the elderly group returned for surveillance less often (67.1% vs 75.1%, P = .024), had greater first follow-up recurrence rates (27.5% vs 13.8%, P < .001), but had similar adverse event rates (1.8% vs 2.8%, P = .619) compared with younger patients. Rates of synchronous neoplasia were similar and high in both groups. CONCLUSIONS: EMR is safe and well tolerated for large polyp removal in patients over 80 years old. Patients aged ≥80 years are less likely to present for follow-up after EMR. They had a higher recurrence rate and a similarly high prevalence of synchronous precancerous lesions. Follow-up after EMR should be encouraged in the elderly, and an attempt to clear the colon of synchronous disease at the time of the initial EMR may be warranted.

Long-Term Radiographic and Functional Outcomes of Patients With Absence of Radiographic Union at 2 Years After Single-Level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective radiographic investigation. OBJECTIVE: To evaluate the long-term radiographic and functional outcomes of patients in whom there is absence of radiographic union at 2 years after single-level anterior cervical discectomy and fusion (ACDF). METHODS: Thirty-one patients were evaluated at standard postoperative time intervals per index trial protocol. Plain film radiographic fusion criteria at the arthrodesis level was defined as interspinous motion (ISM) <1 mm with corresponding motion at a non-arthrodesed superjacent level ISM ≥4 mm. Radiographs and functional outcome measures were acquired at each follow-up visit. Delayed union was defined as lack of radiographic union by 24 months. RESULTS: Nine patients demonstrated radiographic evidence of delayed radiographic union at 24 months. Of those 9 patients, 5 patients demonstrated evidence of union during the follow-up period to 72 months. Despite the absence of radiographic union based on our criteria, 3 of the 4 remaining patients reported remarkable improvements in pain scores and functional outcomes. CONCLUSIONS: The natural history of delayed union at 24 months after ACDF was still favorable despite the prolonged delay in union. The majority of patients (5 of 9) without radiographic union at 24 months did proceed to radiographic union by final follow-up. In addition, patients that did not meet our criteria for fusion maintained postoperative improvements in patient-reported outcome scores. In summary, our study patients undergoing a single-level ACDF with asymptomatic radiographic delayed union at 24 months can expect maintained improvements in postoperative patient-reported outcomes scores and can still progress to successful radiographic fusion.

Failure to follow up on a medically actionable finding from direct to consumer genetic testing: A case report.

BACKGROUND: A 61-year-old woman underwent direct to consumer genetic testing and was found to be homozygous for the C282Y HFE variant (c.845G>A :p.Cys282Tyr) which is classified as pathogenic/likely pathogenic for hereditary hemochromatosis. However, no action was taken by the individual. METHODS: The individual took part in the Mayo Clinic Return of Actionable Variants Empiric (RAVE) study and the actionable finding was confirmed and results disclosed in person by a genetic counselor with subsequent referral to a hepatologist. RESULTS: Further testing revealed iron overload with an elevated ferritin level (560 ng/ml) and increased ferritin saturation (74%). Phlebotomy was initiated with subsequent normalization of the ferritin levels (252 ng/ml). CONCLUSION: This case highlights that actionable genetic results may not be acted on after direct to consumer testing and the need for effective genetic counseling after such testing.

Redox-mediated transformation of a Tb2O3(111) thin film from the cubic fluorite to bixbyite structure.

We used temperature programmed desorption (TPD) and low energy electron diffraction (LEED) to investigate the isomeric structural transformation of a Tb2O3 thin film grown on Pt(111). We find that repeated oxidation and thermal reduction to 1000 K transforms an oxygen-deficient, cubic fluorite (CF) Tb2O3(111) thin film to the well-defined bixbyite, or c-Tb2O3(111) structure, whereas annealing the CF-Tb2O3(111) film in UHV is ineffective in causing this structural transformation. We estimate that the final stabilized film consists of about ten layers of c-Tb2O3(111) in the surface region plus about eight layers of CF-Tb2O3(111) located between the c-Tb2O3(111) and the Pt(111) substrate. Our measurements reveal the development of two distinct O2 TPD peaks during the CF to bixbyite transformation that arise from oxidation of c-Tb2O3 domains to the stoichiometrically-invariant ι-Tb7O12 and δ-Tb11O20 phases and demonstrate that the c-Tb2O3 phase oxidizes more facilely than CF-Tb2O3. We present evidence that nucleation and growth of c-Tb2O3 domains occurs at the buried TbOx/CF-Tb2O3 interface, and that conversion of the interfacial CF-Tb2O3 to bixbyite takes place mainly during thermal reduction of TbOx above ∼900 K and causes newly-formed c-Tb2O3 to advance deeper into the film. The avoidance of low Tb oxidation states may facilitate the CF to bixbyite transformation via this redox mechanism.

Error-Discovery Learning Boosts Student Engagement and Performance, while Reducing Student Attrition in a Bioinformatics Course.

We sought to test a hypothesis that systemic blind spots in active learning are a barrier both for instructors-who cannot see what every student is actually thinking on each concept in each class-and for students-who often cannot tell precisely whether their thinking is right or wrong, let alone exactly how to fix it. We tested a strategy for eliminating these blind spots by having students answer open-ended, conceptual problems using a Web-based platform, and measured the effects on student attrition, engagement, and performance. In 4 years of testing both in class and using an online platform, this approach revealed (and provided specific resolution lessons for) more than 200 distinct conceptual errors, dramatically increased average student engagement, and reduced student attrition by approximately fourfold compared with the original lecture course format (down from 48.3% to 11.4%), especially for women undergraduates (down from 73.1% to 7.4%). Median exam scores increased from 53% to 72-80%, and the bottom half of students boosted their scores to the range in which the top half had scored before the pedagogical switch. By contrast, in our control year with the same active-learning content (but without this "zero blind spots" approach), these gains were not observed.

Reconstruction of a Caregiver Burden Scale: Identifying Culturally Sensitive Items in Saudi Arabia.

ABSTRACTFor this study, we adapted the Montgomery Borgatta Caregiver Burden Scale, used widely in the United States, to the Saudi Arabian context. To produce an Arabic, culturally sensitive version of the scale, we conducted semi-structured interviews with 20 Saudi family caregivers. The Arabic version of the scale was tested, and participants were asked to comment on the appropriateness of items for the construct of "caregiver burden" using the repertory grid technique and laddering procedure - two constructivist methods derived from personal construct theory. From interview findings, we examined the content of the items and the caregiver burden construct itself. Our findings suggest that the use of constructivist methods to refine constructs and quantitative instruments is highly informative. This strategy is feasible even when little is known about the investigated constructs in the target culture and further elucidates our understanding of cross-cultural variations or invariance of different versions of the scale.