Social media for learning: A qualitative exploration of the factors that impact clinical learners' attitudes and intentions

BACKGROUND

Social media has created a revolution in learning and teaching. This study set out to provide a theory-informed exploration of the factors influencing medical students' perspectives of learning with social media using the theory of planned behaviour (TPB) as a framework.

METHODS

The study collected data using semi-structured interviews from seven third year medical students at an undergraduate Australian medical school, who were in their first clinical year. The data were analysed inductively and deductively using TPB.

RESULTS

Three themes emerged relating to the factors that influence medical students' attitudes and intentions regarding using social media for learning: (1) Social media aligns with the needs and preferences of the contemporary learner; (2) rise of medical professionals on social media during the COVID-19 pandemic; and (3) being an informed user of social media for learning. Participants had largely positive views and attitudes towards social media as a learning tool especially for preclinical content due to its capacity for multimodal information delivery and evolving social norms. However, this positivity was tempered by the challenges they faced in determining quality of resources, linking their learning to clinical medicine and accessing specialist content.

CONCLUSION

Social media can play a significant role in medical students' learning. However, its potential as an educational tool can be enhanced by widening access to resources, and implementing strategies that help students increase their evaluative judgement skills to make informed decisions regarding the quality of social media resources and to translate their social media-mediated learning into clinical practice.

Characterization of gastric dysfunction after fundoplication using body surface gastric mapping

BACKGROUND

Adverse gastric symptoms persist in up to 20% of fundoplication operations completed for gastroesophageal reflux disease, causing significant morbidity and driving the need for revisional procedures. Noninvasive techniques to assess the mechanisms of persistent postoperative symptoms are lacking. This study aimed to investigate gastric myoelectrical abnormalities and symptoms in patients after fundoplication using a novel noninvasive body surface gastric mapping (BSGM) device.

METHODS

Patients with a previous fundoplication operation and ongoing significant gastroduodenal symptoms and matched controls were included. BSGM using Gastric Alimetry (Alimetry Ltd) was employed, consisting of a high-resolution 64-channel array, validated symptom-logging application, and wearable reader.

RESULTS

A total of 16 patients with significant chronic symptoms after fundoplication were recruited, with 16 matched controls. Overall, 6 of 16 patients (37.5%) showed significant spectral abnormalities defined by unstable gastric myoelectrical activity (n = 2), abnormally high gastric frequencies (n = 3), or high gastric amplitudes (n = 1). Patients with spectral abnormalities had higher Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index scores than those of patients without spectral abnormalities (3.2 [range, 2.8-3.6] vs 2.3 [range, 2.2-2.8], respectively; P = .024). Moreover, 7 of 16 patients (43.8%) had BSGM test results suggestive of gut-brain axis contributions and without myoelectrical dysfunction. Increasing Principal Gastric Frequency Deviation and decreasing Rhythm Index scores were associated with symptom severity (r > .40; P < .05).

CONCLUSION

A significant number of patients with persistent postfundoplication symptoms displayed abnormal gastric function on BSGM testing, which correlated with symptom severity. Our findings advance the pathophysiologic understanding of postfundoplication disorders, which may inform diagnosis and patient selection for medical therapy and revisional procedures.

Gastric Alimetry Expands Patient Phenotyping in Gastroduodenal Disorders Compared with Gastric Emptying Scintigraphy

INTRODUCTION

Gastric emptying testing (GET) assesses gastric motility, however, is nonspecific and insensitive for neuromuscular disorders. Gastric Alimetry (GA) is a new medical device combining noninvasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared with GET.

METHODS

Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: (i) sensorimotor, (ii) continuous, and (iii) other.

RESULTS

Seventy-five patients were assessed, 77% female. Motility abnormality detection rates were as follows: GET 22.7% (14 delayed, 3 rapid), GA spectral analysis 33.3% (14 low rhythm stability/low amplitude, 5 high amplitude, and 6 abnormal frequency), and combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included sensorimotor 17% (where symptoms strongly paired with gastric amplitude, median r = 0.61), continuous 30%, and other 53%. GA phenotypes showed superior correlations with Gastroparesis Cardinal Symptom Index, Patient Assessment of Upper Gastrointestinal Symptom Severity Index, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores ( P > 0.05). Delayed emptying was not predictive of specific GA phenotypes.

DISCUSSION

GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with increased correlation with symptoms and psychometrics compared with gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.

Idiopathic Slow Transit Constipation: Pathophysiology, Diagnosis, and Management

Slow transit constipation (STC) has an estimated prevalence of 2-4% of the general population, and although it is the least prevalent of the chronic constipation phenotypes, it more commonly causes refractory symptoms and is associated with significant psychosocial stress, poor quality of life, and high healthcare costs. This review provides an overview of the pathophysiology, diagnosis, and management options in STC. STC occurs due to colonic dysmotility and is thought to be a neuromuscular disorder of the colon. Several pathophysiologic features have been observed in STC, including reduced contractions on manometry, delayed emptying on transit studies, reduced numbers of interstitial cells of Cajal on histology, and reduced amounts of excitatory neurotransmitters within myenteric plexuses. The underlying aetiology is uncertain, but autoimmune and hormonal mechanisms have been hypothesised. Diagnosing STC may be challenging, and there is substantial overlap with the other clinical constipation phenotypes. Prior to making a diagnosis of STC, other primary constipation phenotypes and secondary causes of constipation need to be ruled out. An assessment of colonic transit time is required for the diagnosis and can be performed by a number of different methods. There are several different management options for constipation, including lifestyle, dietary, pharmacologic, interventional, and surgical. The effectiveness of the available therapies in STC differs from that of the other constipation phenotypes, and prokinetics often make up the mainstay for those who fail standard laxatives. There are few available management options for patients with medically refractory STC, but patients may respond well to surgical intervention. STC is a common condition associated with a significant burden of disease. It can present a clinical challenge, but a structured approach to the diagnosis and management can be of great value to the clinician. There are many therapeutic options available, with some having more benefits than others.

p21 as a Predictor and Prognostic Indicator of Clinical Outcome in Rectal Cancer Patients

The cell cycle plays a key and complex role in the development of human cancers. p21 is a potent cyclin-dependent kinase inhibitor (CDKI) involved in the promotion of cell cycle arrest and the regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumor cells' behavior and resistance to neoadjuvant and adjuvant therapy. Our study aimed to ascertain the relationship between the differential expression of p21 in rectal cancer and patient survival outcomes. Using tissue microarrays, 266 rectal cancer specimens were immunohistochemically stained for p21. The expression patterns were scored separately in cancer cells retrieved from the center and the periphery of the tumor; compared with clinicopathological data, tumor regression grade (TRG), disease-free, and overall survival. Negative p21 expression in tumor periphery cells was significantly associated with longer overall survival upon the univariate (p = 0.001) and multivariable analysis (p = 0.003, HR = 2.068). Negative p21 expression in tumor periphery cells was also associated with longer disease-free survival in the multivariable analysis (p = 0.040, HR = 1.769). Longer overall survival times also correlated with lower tumor grades (p= 0.011), the absence of vascular and perineural invasion (p = 0.001; p < 0.005), the absence of metastases (p < 0.005), and adjuvant treatment (p = 0.009). p21 expression is a potential predictive and prognostic biomarker for clinical outcomes in rectal cancer patients. Negative p21 expression in tumor periphery cells demonstrated significant association with longer overall survival and disease-free survival. Larger prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy.

Application and Diagnostic Performance of Two-Dimensional Shear Wave Elastography and Liver Fibrosis Scores in Adults with Class 3 Obesity

There are no ideal non-invasive tests for assessing the severity of liver fibrosis in people with metabolic dysfunction-associated steatotic liver disease (MASLD) and class 3 obesity, where body habitus often makes imaging technically challenging. This study aimed to assess the applicability and diagnostic performance of two-dimensional shear wave elastography (2D-SWE), alongside several serum-based liver fibrosis scoring methods, in individuals with class 3 obesity. A cross-sectional study was conducted in patients aged ≥18 years and with a body mass index (BMI) ≥ 40 kg/m2 who were participants in a publicly funded multidisciplinary weight management program in South Western Sydney. The 2D-SWE was performed using the ElastQ Imaging (EQI) procedure with the Phillips EPIQ Elite series ultrasound. An EQI Median value of ≥6.43 kPa was taken as a cutoff score for significant fibrosis, and the scan was considered valid when the liver EQI IQR/Med value was <30%. The Fibrosis-4 (FIB-4) index, AST-to-platelet ratio index (APRI), NAFLD fibrosis score (NFS), and circulating fibroblast activation protein index (FAP index) were calculated from fasting blood samples. The participants (n = 116; 67.2% female) were aged 47.2 ± 12.9 years, with BMI 54.5 ± 11.0 kg/m2. EQI Median values were obtained for 97.4% (113/116) of the 2D-SWE scans, and 91.4% (106/116) of the scans were considered valid. The EQI Median values exhibited a moderately positive correlation with the FIB-4 index (r = 0.438; p < 0.001) and a weakly positive correlation with the APRI (r = 0.388; p < 0.001), NFS (r = 0.210; p = 0.036) and FAP index (r = 0.226; p = 0.020). All liver fibrosis scores were positively correlated with one another. Among those referred for a liver biopsy based on the 2D-SWE and serum scores, half (11/22) underwent liver biopsy, and their 2D-SWE scores exhibited 72.7% accuracy (sensitivity: 71.4%; specificity: 75%) in detecting significant fibrosis. Our results show that 2D-SWE is a feasible, non-invasive test to assess liver fibrosis among people with class 3 obesity. Further research is needed to assess how 2D-SWE can be used alongside existing serum-based risk scores to reliably detect significant fibrosis, which would potentially reduce the need for invasive liver biopsy.

Longitudinal outcome monitoring in patients with chronic gastroduodenal symptoms investigated using the Gastric Alimetry system: study protocol

INTRODUCTION

The Gastric Alimetry platform offers a multimodal assessment of gastric function through body surface gastric mapping (BSGM) and concurrent symptom-tracking via a validated App. We aim to perform a longitudinal cohort study to examine the impact of Gastric Alimetry, and changes in clinical management on patient symptoms, quality of life and psychological health.

METHODS AND ANALYSIS

This is a prospective multicentre longitudinal observational cohort study of participants with chronic gastroduodenal symptoms. Consecutive participants undergoing Gastric Alimetry will be invited to participate. Quality of life will be assessed via EuroQol-5D and the Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life score. Gastrointestinal symptoms will be assessed via the Patient Assessment of Upper Gastrointestinal Symptom Severity index, and the Gastroparesis Cardinal Symptom Index. Psychometrics will be assessed, including anxiety via the General Anxiety Disorder-7, perceived stress using the Perceived Stress Scale 4, and depression via the Patient Health Questionnaire 9. Clinical parameters including diagnoses, investigations and treatments (medication and procedures) will also be captured. Assessments will be made the week after the BSGM test, at 30 days, 90 days, 180 days and 360 days thereafter. The primary outcome is feasibility of longitudinal follow-up of a cohort that have undergone Gastric Alimetry testing; from which patients' continuum of care can be characterised. Secondary outcomes include changes in patient-reported symptoms, quality of life and psychometrics (anxiety, stress and depression). Inferential causal analyses will be performed at the within patient level to explore causal associations between treatment changes and clinical outcomes. The impact of Gastric Alimetry on clinical management will also be captured.

ETHICS AND DISSEMINATION

The protocol has been approved in Aotearoa New Zealand by the Auckland Health Research Ethics Committee. Results will be submitted for conference presentation and peer-reviewed publication.

Deep Mutational Scanning in Disease-related Genes with Saturation Mutagenesis-Reinforced Functional Assays (SMuRF)

Interpretation of disease-causing genetic variants remains a challenge in human genetics. Current costs and complexity of deep mutational scanning methods hamper crowd-sourcing approaches toward genome-wide resolution of variants in disease-related genes. Our framework, Saturation Mutagenesis-Reinforced Functional assays (SMuRF), addresses these issues by offering simple and cost-effective saturation mutagenesis, as well as streamlining functional assays to enhance the interpretation of unresolved variants. Applying SMuRF to neuromuscular disease genes FKRP and LARGE1, we generated functional scores for over 99.8% of all possible coding single nucleotide variants and resolved 310 clinically reported variants of uncertain significance with high confidence, enhancing clinical variant interpretation in dystroglycanopathies. SMuRF also demonstrates utility in predicting disease severity, resolving critical structural regions, and providing training datasets for the development of computational predictors. Our approach opens new directions for enabling variant-to-function insights for disease genes in a manner that is broadly useful for crowd-sourcing implementation across standard research laboratories.

Flavones provide resistance to DUX4-induced toxicity via an mTor-independent mechanism

Facioscapulohumeral muscular dystrophy (FSHD) is among the most common of the muscular dystrophies, affecting nearly 1 in 8000 individuals, and is a cause of profound disability. Genetically, FSHD is linked to the contraction and/or epigenetic de-repression of the D4Z4 repeat array on chromosome 4, thereby allowing expression of the DUX4 gene in skeletal muscle. If the DUX4 transcript incorporates a stabilizing polyadenylation site the myotoxic DUX4 protein will be synthesized, resulting in muscle wasting. The mechanism of toxicity remains unclear, as many DUX4-induced cytopathologies have been described, however cell death does primarily occur through caspase 3/7-dependent apoptosis. To date, most FSHD therapeutic development has focused on molecular methods targeting DUX4 expression or the DUX4 transcript, while therapies targeting processes downstream of DUX4 activity have received less attention. Several studies have demonstrated that inhibition of multiple signal transduction pathways can ameliorate DUX4-induced toxicity, and thus compounds targeting these pathways have the potential to be developed into FSHD therapeutics. To this end, we have screened a group of small molecules curated based on their reported activity in relevant pathways and/or structural relationships with known toxicity-modulating molecules. We have identified a panel of five compounds that function downstream of DUX4 activity to inhibit DUX4-induced toxicity. Unexpectedly, this effect was mediated through an mTor-independent mechanism that preserved expression of ULK1 and correlated with an increase in a marker of active cellular autophagy. This identifies these flavones as compounds of interest for therapeutic development, and potentially identifies the autophagy pathway as a target for therapeutics.

Role of Baseline Gut Microbiota on Response to Fiber Intervention in Individuals with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most prevalent functional gut disorders in the world. Partially hydrolyzed guar gum, a low-viscosity soluble fiber, has shown promise in the management of IBS-related symptoms. In this study, we aimed to determine if an individual's baseline gut microbiota impacted their response to a partially hydrolyzed guar gum intervention. Patients diagnosed with IBS undertook a 90-day intervention and follow-up. IBS symptom severity, tolerability, quality-of-life, and fecal microbiome composition were recorded during this study. Patients with normal microbiota diversity (Shannon index ≥ 3) showed significant improvements to IBS symptom scores, quality-of-life, and better tolerated the intervention compared to patients with low microbiota diversity (Shannon index < 3). Our findings suggest that an individual's baseline microbiome composition exerts a substantial influence on their response to fiber intervention. Future investigations should explore a symbiotic approach to the treatment of IBS.

Baseline Characteristics of Canadian Patients in the Psoriasis Longitudinal Assessment and Registry (PSOLAR)

BACKGROUND

The Psoriasis Longitudinal Assessment and Registry (PSOLAR) is a global, prospective, longitudinal, disease-based registry. It serves as a post-marketing safety commitment with a focus on patients with moderate to severe plaque psoriasis who are candidates for systemic therapy.

OBJECTIVES

To describe the baseline disease demographics and clinical characteristics of a Canadian subgroup of participants enrolled in PSOLAR.

METHODS

Baseline demographic/disease characteristics, medical histories, and previous psoriasis treatments for Canadian patients in PSOLAR were summarized using descriptive statistics.

RESULTS

There were 1896 patients analyzed in the Canadian subgroup at 37 clinical sites, accounting for 15.7% of the global PSOLAR population. Baseline disease and clinical characteristics were as expected for a moderate to severe psoriasis population and were generally similar to the global PSOLAR population. Two distinctions were noted in the Canadian subgroup versus those enrolled globally: a higher proportion of patients were overweight/obese (84.7% vs. 80.4%) and male (61.4% vs. 54.7%). In addition, the Canadian subgroup had numerically higher historical peak disease activity (PGA score 3.35 vs. 3.1) and longer disease duration (22.3 years vs. 17.5 years). Canadian PSOLAR patients reported a variety of comorbidities, including psoriatic arthritis (31.5%), hypertension (34.6%), hyperlipidemia (24.3%), mental illness (24.1%), and inflammatory bowel disease (1.6%).

CONCLUSION

The Canadian subgroup of PSOLAR patients was generally similar to those enrolled globally with respect to baseline disease demographics and clinical characteristics. Multiple comorbidities are noted in the Canadian subgroup, underscoring the need for a holistic approach to the treatment of psoriatic patients.

Gastric Alimetry® Test Interpretation in Gastroduodenal Disorders: Review and Recommendations

Chronic gastroduodenal symptoms are prevalent worldwide, and there is a need for new diagnostic and treatment approaches. Several overlapping processes may contribute to these symptoms, including gastric dysmotility, hypersensitivity, gut-brain axis disorders, gastric outflow resistance, and duodenal inflammation. Gastric Alimetry® (Alimetry, New Zealand) is a non-invasive test for evaluating gastric function that combines body surface gastric mapping (high-resolution electrophysiology) with validated symptom profiling. Together, these complementary data streams enable important new clinical insights into gastric disorders and their symptom correlations, with emerging therapeutic implications. A comprehensive database has been established, currently comprising > 2000 Gastric Alimetry tests, including both controls and patients with various gastroduodenal disorders. From studies employing this database, this paper presents a systematic methodology for Gastric Alimetry test interpretation, together with an extensive supporting literature review. Reporting is grouped into four sections: Test Quality, Spectral Analysis, Symptoms, and Conclusions. This review compiles, assesses, and evaluates each of these aspects of test assessment, with discussion of relevant evidence, example cases, limitations, and areas for future work. The resultant interpretation methodology is recommended for use in clinical practice and research to assist clinicians in their use of Gastric Alimetry as a diagnostic aid and is expected to continue to evolve with further development.

Principles and clinical methods of body surface gastric mapping: Technical review

BACKGROUND AND PURPOSE

Chronic gastric symptoms are common, however differentiating specific contributing mechanisms in individual patients remains challenging. Abnormal gastric motility is present in a significant subgroup, but reliable methods for assessing gastric motor function in clinical practice are lacking. Body surface gastric mapping (BSGM) is a new diagnostic aid, employs multi-electrode arrays to measure and map gastric myoelectrical activity non-invasively in high resolution. Clinical adoption of BSGM is currently expanding following studies demonstrating the ability to achieve specific patient subgrouping, and subsequent regulatory clearances. An international working group was formed in order to standardize clinical BSGM methods, encompassing a technical group developing BSGM methods and a clinical advisory group. The working group performed a technical literature review and synthesis focusing on the rationale, principles, methods, and clinical applications of BSGM, with secondary review by the clinical group. The principles and validation of BSGM were evaluated, including key advances achieved over legacy electrogastrography (EGG). Methods for BSGM were reviewed, including device design considerations, patient preparation, test conduct, and data processing steps. Recent advances in BSGM test metrics and reference intervals are discussed, including four novel metrics, being the 'principal gastric frequency', BMI-adjusted amplitude, Gastric Alimetry Rhythm Index™, and fed: fasted amplitude ratio. An additional essential element of BSGM has been the introduction of validated digital tools for standardized symptom profiling, performed simultaneously during testing. Specific phenotypes identifiable by BSGM and the associated symptom profiles were codified with reference to pathophysiology. Finally, knowledge gaps and priority areas for future BSGM research were also identified by the working group.

Mechanism of spirometry associated gastro-esophageal reflux in individuals undergoing esophageal assessment

Persistent variability observed during spirometry, even when technical and personal factors are controlled, has prompted interest in uncovering its underlying mechanisms. Notably, our prior investigations have unveiled that spirometry has the potential to trigger gastro-esophageal reflux in a susceptible population. This current study embarks on elucidating the intricate mechanisms orchestrating reflux induced by spirometry. To achieve this, we enlisted twenty-four (24) participants exhibiting reflux symptoms for esophageal assessment. These participants underwent two sets of spirometry sessions, interspersed with a 10-minute intermission, during which we closely scrutinized fluid flow dynamics and esophageal function through high-resolution impedance esophageal manometry. Our comprehensive evaluation juxtaposed baseline manometric parameters against their equivalents during the initial spirometry session, the intervening rest period, and the subsequent spirometry session. Remarkably, impedance values, serving as a metric for fluid quantity, exhibited a substantial elevation during each spirometry session and the ensuing recovery interval in the pan-esophageal and hypopharyngeal regions when compared to baseline levels. Additionally, the resting pressure of the lower esophageal sphincter experienced a noteworthy reduction subsequent to the first bout of spirometry (13.6 ± 8.8 mmHg) in comparison to the baseline pressure (22.5 ± 13.3 mmHg). Furthermore, our observations unveiled a decline in spirometric parameters-FEV1 (0.14 ± 0.24 L, P = 0.042) and PEFR (0.67 L/s, P = 0.34)-during the second spirometry session when contrasted with the first session. Collectively, our study underscores the compelling evidence that spirometry maneuvers can elicit gastro-esophageal reflux by eliciting intra-esophageal pressure differentials and inducing temporary relaxation of the lower esophageal sphincter.

Comparison of Gastric Alimetry® body surface gastric mapping versus electrogastrography spectral analysis

Electrogastrography (EGG) non-invasively evaluates gastric motility but is viewed as lacking clinical utility. Gastric Alimetry® is a new diagnostic test that combines high-resolution body surface gastric mapping (BSGM) with validated symptom profiling, with the goal of overcoming EGG's limitations. This study directly compared EGG and BSGM to define performance differences in spectral analysis. Comparisons between Gastric Alimetry BSGM and EGG were conducted by protocolized retrospective evaluation of 178 subjects [110 controls; 68 nausea and vomiting (NVS) and/or type 1 diabetes (T1D)]. Comparisons followed standard methodologies for each test (pre-processing, post-processing, analysis), with statistical evaluations for group-level differences, symptom correlations, and patient-level classifications. BSGM showed substantially tighter frequency ranges vs EGG in controls. Both tests detected rhythm instability in NVS, but EGG showed opposite frequency effects in T1D. BSGM showed an 8× increase in the number of significant correlations with symptoms. BSGM accuracy for patient-level classification was 0.78 for patients vs controls and 0.96 as compared to blinded consensus panel; EGG accuracy was 0.54 and 0.43. EGG detected group-level differences in patients, but lacked symptom correlations and showed poor accuracy for patient-level classification, explaining EGG's limited clinical utility. BSGM demonstrated substantial performance improvements across all domains.

Determining efficacy of dynamic multimedia bowel preparation instructions versus standard instructions on adenoma detection and patient reported measures (DIGICLEAN trial): a study protocol for a multicentre, colonoscopist-blinded, randomised controlled trial

INTRODUCTION

Colonoscopy plays important roles in bowel cancer screening and treatment. Poor bowel preparation occurs in 20-25% of colonoscopies. This negatively impacts adenoma and sessile serrated lesion detection rates, procedural time, requirement for repeat colonoscopies, healthcare costs and likelihood of patient withdrawal from screening programmes. It is unclear whether a combination of multimedia modalities can improve bowel preparation quality, adenoma detection rates and patient-reported measures in those undergoing colonoscopy assessment.

METHODS

The DIGICLEAN trial is a prospective, parallel, multicentre, colonoscopist-blinded, randomised controlled trial. The trial will enrol 1294 participants aged 45 years and older who are indicated for a colonoscopy as an outpatient with a positive faecal occult blood test, iron deficiency anaemia or rectal bleeding. Participants will be randomised into the interventional arm, where bowel preparation instructions are delivered via a web-based application which uses scheduled short messaging service, regular patient survey assessment, email and videos; or the control arm, where routine standard written, verbal or emailed instructions are administered. The web-based application will assess patient-reported bloating, constipation and dietary adherence leading up to the colonoscopy. Depending on patient responses, additional aperients may be encouraged digitally in the interventional arm with same instructions made available in written format for the control arm. Patient-reported measures will be collected in both arms the day after the procedure using the validated Newcastle ENDOPREM questionnaire. In some sites, participants will undergo digital pre-anaesthetic screening as well. The co-primary endpoints are the adenoma detection rates and patient-reported measures taken after the colonoscopy.

ETHICS AND DISSEMINATION

Ethics approval for this study was obtained from the Western Sydney Local Health District Human Research Ethics Committee (2022/ETH00059). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12622000747729.

Safety of guselkumab in patients with psoriasis with a history of malignancy: 5-year results from the VOYAGE 1 and VOYAGE 2 trials

The VOYAGE 1 and 2 studies of guselkumab in moderate-to-severe psoriasis are among the first studies of biologics to include patients with a history of malignancy. In these studies, 18 guselkumab-treated patients had a history of malignancy (excluding nonmelanoma skin cancer) &gt; 5 years prior to enrolment. These 18 patients were exposed to guselkumab for up to 5 years; during this time, one patient had a recurrence of bronchial carcinoma, and three patients developed new malignancies (breast cancer, melanoma and sebaceous carcinoma). All patients with new or recurrent malignancies had underlying risk factors for malignancy. Overall, the results of this analysis in a small population of patients with a history of malignancy support the favourable long-term safety profile of guselkumab.

Normative Values for Body Surface Gastric Mapping Evaluations of Gastric Motility Using Gastric Alimetry: Spectral Analysis

INTRODUCTION

Body surface gastric mapping (BSGM) is a new noninvasive test of gastric function. BSGM offers several novel and improved biomarkers of gastric function capable of differentiating patients with overlapping symptom profiles. The aim of this study was to define normative reference intervals for BSGM spectral metrics in a population of healthy controls.

METHODS

BSGM was performed in healthy controls using Gastric Alimetry (Alimetry, New Zealand) comprising a stretchable high-resolution array (8 × 8 electrodes; 196 cm 2 ), wearable Reader, and validated symptom-logging App. The evaluation encompassed a fasting baseline (30 minutes), 482 kCal meal, and 4-hour postprandial recording. Normative reference intervals were calculated for BSGM metrics including the Principal Gastric Frequency, Gastric Alimetry Rhythm Index (a measure of the concentration of power in the gastric frequency band over time), body mass index (BMI)-adjusted amplitude (μV), and fed:fasted amplitude ratio. Data were reported as median and reference interval (5th and/or 95th percentiles).

RESULTS

A total of 110 subjects (55% female, median age 32 years [interquartile range 24-50], median BMI 23.8 kg/m 2 [interquartile range 21.4-26.9]) were included. The median Principal Gastric Frequency was 3.04 cycles per minute; reference interval: 2.65-3.35 cycles per minute. The median Gastric Alimetry Rhythm Index was 0.50; reference interval: ≥0.25. The median BMI-adjusted amplitude was 37.6 μV; reference interval: 20-70 μV. The median fed:fasted amplitude ratio was 1.85; reference interval ≥1.08. A higher BMI was associated with a shorter meal-response duration ( P = 0.014).

DISCUSSION

This study provides normative reference intervals for BSGM spectral data to inform diagnostic interpretations of abnormal gastric function.

Gastric Alimetry ® improves patient phenotyping in gastroduodenal disorders compared to gastric emptying scintigraphy alone

Objectives

Gastric emptying testing (GET) assesses gastric motility, however is non-specific and insensitive for neuromuscular disorders. Gastric Alimetry® (GA) is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared to GET.

Methods

Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: i) sensorimotor; ii) continuous; and iii) other.

Results

75 patients were assessed; 77% female. Motility abnormality detection rates were: GET 22.7% (14 delayed, 3 rapid); GA spectral analysis 33.3% (14 low rhythm stability / low amplitude; 5 high amplitude; 6 abnormal frequency); combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included: sensorimotor 17% (where symptoms strongly paired with gastric amplitude; median r=0.61); continuous 30%; other 53%. GA phenotypes showed superior correlations with GCSI, PAGI-SYM, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores (p>0.05). Delayed emptying was not predictive of specific GA phenotypes.

Conclusions

GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with improved correlation with symptoms and psychometrics compared to gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.

Study Highlights

1) WHAT IS KNOWN Chronic gastroduodenal symptoms are common, costly and greatly impact on quality of lifeThere is a poor correlation between gastric emptying testing (GET) and symptomsGastric Alimetry® is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling 2) WHAT IS NEW HERE Gastric Alimetry generates a 1.5x higher yield for motility abnormalities than GETWith symptom profiling, Gastric Alimetry identified 2.7x more specific patient categories than GETGastric Alimetry improves clinical phenotyping, with improved correlation with symptoms and psychometrics compared to GET.

Transcriptome and Proteome Profiling of Primary Human Gastric Interstitial Cells of Cajal Predicts Pacemaker Networks

Background/Aims

Interstitial cells of Cajal (ICC) are specialized gastrointestinal (GI) pacemaker cells required for normal GI motility. Dysfunctions in ICC have been reported in patients with GI motility disorders, such as gastroparesis, who exhibit debilitating symptoms and greatly reduced quality of life. While the proteins, calcium-activated chloride channel anoctamin-1 (ANO1) and the receptor tyrosine kinase (KIT), are known to be expressed by human ICC, relatively little is known about the broad molecular circuitry underpinning human ICC functions. The present study therefore investigates the transcriptome and proteome of ANO1-expressing, KIT^low/CD45^-/CD11B^- ICC obtained from primary human gastric tissue.

Methods

Excess human gastric tissue resections were obtained from sleeve gastrectomy patients. ICC were purified using fluorescence-activated cell sorting (FACSorting). Then, ICC were characterized by using immunofluorescence, real-time polymerase chain reaction, RNA-sequencing and mass spectrometry.

Results

Compared to unsorted cells, real-time polymerase chain reaction showed the KIT^low/CD45^-/CD11B^- ICC had: a 9-fold (P < 0.05) increase in ANO1 expression; unchanged KIT expression; and reduced expression for genes associated with hematopoietic cells (CD68, > 10-fold, P < 0.001) and smooth muscle cells (DES, > 4-fold, P < 0.05). RNA-sequencing and gene ontology analyses of the KIT^low/CD45^-/CD11B^- cells revealed a transcriptional profile consistent with ICC function. Similarly, mass spectrometry analyses of the KIT^low/CD45^-/CD11B^- cells presented a proteomic profile consistent with ICC activities. STRING-based protein interaction analyses using the RNA-sequencing and proteomic datasets predicted protein networks consistent with ICC-associated pacemaker activity and ion transport.

Conclusion

These new and complementary datasets provide a valuable molecular framework for further understanding how ICC pacemaker activity regulates smooth muscle contraction in both normal GI tissue and GI motility disorders.

Prognostic Significance of MRE11 Overexpression in Colorectal Cancer Patients

Meiotic recombination 11 (MRE11) plays a critical role in the DNA damage response and maintenance of genome stability and is associated with the prognosis for numerous malignancies. Here, we explored the clinicopathological significance and prognostic value of MRE11 expression in colorectal cancer (CRC), a leading cause of cancer-related deaths worldwide. Samples from 408 patients who underwent surgery for colon and rectal cancer between 2006 and 2011, including a sub-cohort of 127 (31%) patients treated with adjuvant therapy, were analyzed. In Kaplan-Meier survival analyses, we found that high MRE11 expression in the tumor center (TC) was significantly associated with poor disease-free survival (DFS; p = 0.045) and overall survival (OS; p = 0.039). Intriguingly, high MRE11 expression in the TC was also significantly correlated with reduced DFS (p = 0.005) and OS (p = 0.010) in the subgroup with right-sided primary CRC. In multivariate analyses, high MRE11 expression (hazard ratio [HR] = 1.697, 95% confidence interval [CI]: 1.034-2.785; p = 0.036) and lymphovascular/perineural invasion (LVI/PNI; HR = 1.922, 95% CI 1.122-3.293; p = 0.017) showed significant association with worse OS in patients with right-sided tumors but not those with left-sided tumors. Moreover, in patients with right-sided tumors, high MRE11 was associated with worse OS for those with lymph node involvement (p = 0.006) and LVI/PNI (p = 0.049). Collectively, our results suggest that MRE11 may serve as an independent prognostic marker in those with right-sided severe CRC, with clinical value in the management of these patients.

Flavones provide resistance to DUX4-induced toxicity via an mTor-independent mechanism

Facioscapulohumeral muscular dystrophy (FSHD) is among the most common of the muscular dystrophies, affecting nearly 1 in 8000 individuals, and is a cause of profound disability. Genetically, FSHD is linked to the contraction and/or epigenetic de-repression of the D4Z4 repeat array on chromosome 4, thereby allowing expression of the DUX4 gene in skeletal muscle. If the DUX4 transcript incorporates a stabilizing polyadenylation site the myotoxic DUX4 protein will be synthesized, resulting in muscle wasting. The mechanism of toxicity remains unclear, as many DUX4-induced cytopathologies have been described, however cell death does primarily occur through caspase 3/7-dependent apoptosis. To date, most FSHD therapeutic development has focused on molecular methods targeting DUX4 expression or the DUX4 transcript, while therapies targeting processes downstream of DUX4 activity have received less attention. Several studies have demonstrated that inhibition of multiple signal transduction pathways can ameliorate DUX4-induced toxicity, and thus compounds targeting these pathways have the potential to be developed into FSHD therapeutics. To this end, we have screened a group of small molecules curated based on their reported activity in relevant pathways and/or structural relationships with known toxicity-modulating molecules. We have identified a panel of five compounds that function downstream of DUX4 activity to inhibit DUX4-induced toxicity. Unexpectedly, this effect was mediated through an mTor-independent mechanism that preserved expression of ULK1 and correlated with an increase in a marker of active cellular autophagy. This identifies these flavones as compounds of interest for therapeutic development, and potentially identifies the autophagy pathway as a target for therapeutics.

NCCN Guidelines® Insights: Hematopoietic Cell Transplantation, Version 3.2022

The NCCN Guidelines for Hematopoietic Cell Transplantation (HCT) provide an evidence- and consensus-based approach for the use of autologous and allogeneic HCT in the management of malignant diseases in adult patients. HCT is a potentially curative treatment option for patients with certain types of malignancies; however, recurrent malignancy and transplant-related complications often limit the long-term survival of HCT recipients. The purpose of these guidelines is to provide guidance regarding aspects of HCT, including pretransplant recipient evaluation, hematopoietic cell mobilization, and treatment of graft-versus-host disease-a major complication of allogeneic HCT-to enable the patient and clinician to assess management options in the context of an individual patient's condition. These NCCN Guidelines Insights provide a summary of the important recent updates to the NCCN Guidelines for HCT, including the incorporation of a newly developed section on the Principles of Conditioning for HCT.

An obscure cause of gastrointestinal bleeding: Recurrent duodenal variceal hemorrhage treated with intramuscular octreotide in the absence of portal hypertension

Duodenal varices (DVs) are ectopic gastrointestinal varices (ECVs) associated with portal hypertension (PH). We present the case of an 82-year-old woman who presented with symptomatic anemia secondary to DV hemorrhage diagnosed on oesophagogastroduodenoscopy. This lesion was treated with endoscopic adrenaline injection and clip application. The patient re-presented on multiple occasions with bleeding recurrence localized to the duodenum, which was managed with intramuscular octreotide and oral beta-blockade resulting in sustained remission of bleeding. This case highlights a rare cause of upper gastrointestinal hemorrhage and highlights the value of somatostatin analogues for conservative treatment of DVs.

Placental abnormalities in type 1 and type 2 diabetes mellitus: a systematic review and metaanalysis of shear wave elastography

OBJECTIVE

This study aimed to describe the placental changes occurring in women with preexisting diabetes mellitus and to determine if elastography can detect placental changes in vivo.

DATA SOURCES

PubMed, Embase, Medline, and Cochrane were searched to identify English language studies published until July 2020.

STUDY ELIGIBILITY CRITERIA

1) For key question 1, studies that described histopathologic changes in placentas from women with known diabetes mellitus and 2) for key question 2, those that described structural-placental changes detectable by elastography in high-risk pregnancies (eg, those complicated by preeclampsia and/or fetal growth restriction), were included.

METHODS

For key question 1, we grouped placental pathologies using the Amsterdam International Consensus Group definitions. For key question 2, we conducted a metaanalysis including all data from studies reporting placental stiffness in meters per second (m/s) or kilopascals (kPa). The mean difference (95% confidence interval) was calculated using a random effects model.

RESULTS

Data were extracted from 14 studies of placental histopathology in women with known diabetes. In this group, a wide variety of placental histopathologic changes are described, though none are considered pathognomonic. The histopathologic changes including maternal vascular malperfusion, fetal vascular malperfusion, and/or infectious/inflammatory/other changes were divided into 3 broad categories on the basis of presumed etiology. A total of 15 studies reported the placental stiffness scores in women with a high-risk pregnancy vs those with a normal pregnancy. Only 1 reported stiffness scores for placentas in women with preexisting diabetes mellitus (N<10 women). Pooled analysis of 14 studies with available data included 478 "high-risk pregnancies" and 828 control or healthy pregnancies. Maternal-derived pathologies resulted in higher placental stiffness (mean difference 4.5 kPa [95% confidence interval, 3.16-5.87]) compared with control or healthy pregnancies. Fetal-derived pathologies also resulted in higher placental stiffness (mean difference of 6.5 kPa [95% confidence interval, 1.08-11.86]) compared with control or healthy pregnancies.

CONCLUSION

Shear wave elastography may provide an in vivo approximation of placental histopathology in women with certain kinds of high-risk pregnancies. A high-risk pregnancy may involve maternal- and fetal-derived pathologies. Further studies, particularly in women with preexisting diabetes, are needed to confirm this observation.

Performance and usability testing of an automated tool for detection of peripheral artery disease using electronic health records

Peripheral artery disease (PAD) is a common cardiovascular disorder that is frequently underdiagnosed, which can lead to poorer outcomes due to lower rates of medical optimization. We aimed to develop an automated tool to identify undiagnosed PAD and evaluate physician acceptance of a dashboard representation of risk assessment. Data were derived from electronic health records (EHR). We developed and compared traditional risk score models to novel machine learning models. For usability testing, primary and specialty care physicians were recruited and interviewed until thematic saturation. Data from 3168 patients with PAD and 16,863 controls were utilized. Results showed a deep learning model that utilized time engineered features outperformed random forest and traditional logistic regression models (average AUCs 0.96, 0.91 and 0.81, respectively), P < 0.0001. Of interviewed physicians, 75% were receptive to an EHR-based automated PAD model. Feedback emphasized workflow optimization, including integrating risk assessments directly into the EHR, using dashboard designs that minimize clicks, and providing risk assessments for clinically complex patients. In conclusion, we demonstrate that EHR-based machine learning models can accurately detect risk of PAD and that physicians are receptive to automated risk detection for PAD. Future research aims to prospectively validate model performance and impact on patient outcomes.

Single-cell RNA sequencing predicts motility networks in purified human gastric interstitial cells of Cajal

BACKGROUND

Gastrointestinal (GI) motility disorders affect millions of people worldwide, yet they remain poorly treated in part due to insufficient knowledge of the molecular networks controlling GI motility. Interstitial cells of Cajal (ICC) are critical GI pacemaker cells, and abnormalities in ICC are implicated in GI motility disorders. Two cell surface proteins, KIT and ANO1, are used for identifying ICC. However, difficulties accessing human tissue and the low frequency of ICC in GI tissues have meant human ICC are insufficiently characterized. Here, a range of characterization assays including single-cell RNA sequencing (scRNA-seq) was performed using KIT⁺ CD45^- CD11B^- primary human gastric ICC to better understand networks controlling human ICC biology.

METHODS

Excess sleeve gastrectomy tissues were dissected; ICC were analyzed by immunofluorescence, fluorescence-activated cell sorting (FACSorting), real-time PCR, mass spectrometry, and scRNA-seq.

KEY RESULTS

Immunofluorescence identified ANO1⁺ /KIT⁺ cells throughout the gastric muscle. Compared to the FACSorted negative cells, PCR showed the KIT⁺ CD45^- CD11B^- ICC were enriched 28-fold in ANO1 expression (p < 0.01). scRNA-seq analysis of the KIT^- CD45⁺ CD11B⁺ and KIT⁺ CD45^- CD11B^- ICC revealed separate clusters of immune cells and ICC (respectively); cells in the ICC cluster expressed critical GI motility genes (eg, CAV1 and PRKG1). The scRNA-seq data for these two cell clusters predicted protein interaction networks consistent with immune cell and ICC biology, respectively.

CONCLUSIONS & INFERENCES

The single-cell transcriptome of purified KIT⁺ CD45^- CD11B^- human gastric ICC presented here provides new molecular insights and hypotheses into evolving models of GI motility. This knowledge will provide an improved framework to investigate targeted therapies for GI motility disorders.

Endocrine disruptors: Challenges and future directions in epidemiologic research

Public concern about the impact of endocrine disrupting chemicals (EDCs) on both humans and the environment is growing steadily. Epidemiologic research provides key information towards our understanding of the relationship between environmental exposures like EDCs and human health outcomes. Intended for researchers in disciplines complementary to epidemiology, this paper highlights the importance and challenges of epidemiologic research in order to present the key elements pertaining to the design and interpretation of an epidemiologic study on EDCs. The conduct of observational studies on EDCs derives from a thoughtful research question, which will help determine the subsequent methodological choices surrounding the careful selection of the study population (including the comparison group), the adequate ascertainment of exposure(s) and outcome(s) of interest, and the application of methodological and statistical concepts more specific to epidemiology. The interpretation of epidemiologic results may be arduous due to the latency occurring between EDC exposure and certain outcome(s), the complexity in capturing EDC exposure(s), and traditional methodological and statistical issues that also deserve consideration (e.g., confounding, effect modification, non-monotonic responses). Moving forward, we strongly advocate for an integrative approach of expertise in the fields of epidemiology, exposure science, risk assessment and toxicology to adequately study the health risks associated with EDCs while tackling their challenges.

Checkpoint Inhibitors and the Gut

Checkpoint inhibitors have revolutionized treatments in modern oncology, including many conditions previously relegated to palliative therapies only. However, emerging recognition of checkpoint inhibitor-related adverse events has complicated the status of checkpoint inhibitor-related therapies. This review article discusses gastrointestinal adverse events as a result of checkpoint inhibitor therapy, as well as limitations of current guidelines, thus providing recommendations for guideline revision and future study direction.

New Internet of Medical Things for Home-Based Treatment of Anorectal Disorders

Home-based healthcare provides a viable and cost-effective method of delivery for resource- and labour-intensive therapies, such as rehabilitation therapies, including anorectal biofeedback. However, existing systems for home anorectal biofeedback are not able to monitor patient compliance or assess the quality of exercises performed, and as a result have yet to see wide spread clinical adoption. In this paper, we propose a new Internet of Medical Things (IoMT) system to provide home-based biofeedback therapy, facilitating remote monitoring by the physician. We discuss our user-centric design process and the proposed architecture, including a new sensing probe, mobile app, and cloud-based web application. A case study involving biofeedback training exercises was performed. Data from the IoMT was compared against the clinical standard, high-definition anorectal manometry. We demonstrated the feasibility of our proposed IoMT in providing anorectal pressure profiles equivalent to clinical manometry and its application for home-based anorectal biofeedback therapy.

The Short-Term Effects and Tolerability of Low-Viscosity Soluble Fibre on Gastroparesis Patients: A Pilot Clinical Intervention Study

Gastroparesis is a motility disorder that causes severe gastric symptoms and delayed gastric emptying, where the majority of sufferers are females (80%), with 29% of sufferers also diagnosed with Type-1 or Type-2 diabetes. Current clinical recommendations involve stringent dietary restriction and includes the avoidance and minimization of dietary fibre. Dietary fibre lowers the glycaemic index of food, reduces inflammation and provides laxation. Lack of dietary fibre in the diet can affect long-term gastrointestinal health. Our previously published rheological study demonstrated that "low-viscosity" soluble fibres could be a potentially tolerable source of fibre for the gastroparetic population. A randomised controlled crossover pilot clinical study was designed to compare Partially-hydrolysed guar gum or PHGG (test fibre 1), gum Arabic (test fibre 2), psyllium husk (positive control) and water (negative control) in mild-to-moderate symptomatic gastroparesis patients (requiring no enteral tube feeding). The principal aim of the study was to determine the short-term physiological effects and tolerability of the test fibres. In n = 10 female participants, post-prandial blood glucose, gastroparesis symptoms, and breath test measurements were recorded. Normalized clinical data revealed that test fibres PHGG and gum Arabic were able to regulate blood glucose comparable to psyllium husk, while causing far fewer symptoms, equivalent to negative control. The test fibres did not greatly delay mouth-to-caecum transit, though more data is needed. The study data looks promising, and a longer-term study investigating these test fibres is being planned.

772 MHC-I skewing in mutant calreticulin-positive myeloproliferative neoplasms is countered by heteroclitic peptide cancer vaccination

Background

The majority of JAK2V617F-negative myeloproliferative neoplasms (MPN) have disease-initiating frameshift mutations in calreticulin (CALR) resulting in a common novel C-terminal mutant fragment (CALRMUT), representing an attractive source of neoantigens for cancer vaccines. However, studies have shown that CALRMUT-specific T cells are rare in CALRMUT MPN patients, but the underlying reasons for this phenomenon are unknown. We speculate that this is due to an increased chance of immune-mediated tumor rejection by individuals expressing one of these MHC-I alleles such that the disease never clinically manifests. As a consequence of this MHC-I allele restriction, we reasoned that CALRMUT MPN patients would not efficiently respond to cancer vaccines composed of the CALRMUT neoantigen, but could do so when immunized with a properly epitope-optimized CALRMUT heteroclitic peptide vaccine approach.

Methods

We examined MHC-I allele frequency in CALRMUT MPN patients from two independent cohorts to identify under-represented MHC-I alleles. These MHC-I alleles were assessed for their ability to bind to CALRMUT-derived peptides using NetMHC and were subsequently validated experimentally in healthy donors and in CALRMUT MPN patients having received a CALRMUT cancer vaccine (clinical trial NCT03566446) to determine if these MHC-I were potentiating immunogenicity against the CALRMUT antigen. Epitope-optimized heteroclitic variants of the CALRMUT neoantigen were identified and tested experimentally in vitro in human PBMCs and in vivo in mice for their ability to mount an immune response against the non-modified CALRMUT neoantigen.

Results

We observed that MHC-I alleles that present CALRMUT neoepitopes with high affinity are under-represented in CALRMUT MPN patients. Heteroclitic CALRMUT peptides specifically designed for CALRMUT MPN patient MHC-I alleles efficiently elicited a cross-reactive CD8+ T cell response in human PBMC samples otherwise unable to respond to the matched weakly immunogenic CALRMUT native peptides. We also modeled this effect in mice and observed that C57BL/6J mice, which are unable to mount an immune response to the human CALRMUT fragment, can mount a cross-reactive CD8+ T cell response against a CALRMUT-derived peptide upon heteroclitic peptide immunization and this was further amplified by combining the heteroclitic peptide vaccine with blockade of the immune checkpoint molecule PD-1.

Conclusions

Our study shows that MHC-I alleles able to present CALRMUT neoepitopes are under-represented in CALRMUT MPN patients, demonstrating that MHC-I haplotype is a major mechanism of passive immune-evasion in CALRMUT MPN. However, we show that a cancer vaccine composed of heteroclitic variants of the CALRMUT antigen could overcome this limitation.

Ethics Approval

Approval was obtained for the use of patient-derived specimens and access to clinical data extracted from patient charts by the Institutional Review Boards at Memorial Sloan Kettering Cancer Center, the Dana-Farber Cancer Institute and the Massachusetts General Hospital, as well as by the Danish Regional Science Ethics Committee.

Inter-rater reliability of occupational exposure assessment in a case-control study of female breast cancer

The objective of this paper was to estimate the inter-rater reliability of expert assessments of occupational exposures. An inter-rater reliability sub-study was conducted within a population-based case-control study of postmenopausal breast cancer. Detailed information on lifetime occupational histories was obtained from participants and two industrial hygienists assigned exposures to 185 jobs using a checklist of 293 agents. Experts rated exposure for each job-agent combination according to exposure status (unexposed/exposed), confidence that the exposure occurred (possible/probable/definite), intensity (low/medium/high), and frequency (% time per week). The statistical unit of observation was each job-agent assessment (185 jobs × 293 agents = 54,205 assessments per expert). Crude agreement, Gwet AC1/2 statistics, and Cohen's Kappa were used to estimate inter-rater agreement for confidence and intensity; for frequency, the intra-class correlation coefficient (ICC) was used. The majority of job-agent combinations were evaluated by the two experts to be not exposed (crude agreement >98% of decisions). The degree of agreement between the experts for the confidence of exposure status was Gwet AC1/2 = 0.99 (95% CI: 0.99-0.99), and for intensity, a Gwet AC2 = 0.99 (95% CI: 0.99-0.99). For frequency, an ICC of 0.31 (95% CI: 0.26-0.35) was found. A sub-analysis restricted to job-agent combinations for which the two experts agreed on exposure status revealed a moderate agreement for confidence of exposure (Gwet AC2 = 0.66) and high agreement for intensity (Gwet AC2 = 0.96). For frequency, the ICC was 0.52 (95% CI: 0.47-0.57). A high level of inter-rater agreement was found for identifying exposures and for coding intensity, but agreement was lower for the coding of frequency of exposure.

Microfluidic integrated capacitive biosensor for C-reactive protein label-free and real-time detection

A microfluidic chip has been integrated with a capacitive biosensor based on mass-producible three-dimensional (3D) interdigital electrode arrays. To achieve the monitoring of biosensor preparation and cardiac- and periodontitis-related biomarkers, all the processes were detected in a continuously on-site way. Fabrication steps for the microfluidic chip-bonded 3D interdigital capacitor biosensor include gold thiol modification, the activation of EDC/sulfo-NHS, and the bioconjugation of antibodies. Fluorescent characterization and X-ray photoelectron spectroscopy analysis were applied to assess the successful immobilization of the C-reactive protein (CRP) antibody. The experimental results indicate the good specificity and high sensitivity of the microfluidic integrated 3D capacitive biosensor. The limit of detection of the 3D capacitive biosensor for CRP label-free detection was about 1 pg mL^-1. This 3D capacitive biosensor with integrated microfluidics is mass-producible and has achieved the on-site continuous detection of cardiac- and periodontitis-related biomarkers with high performance.

Ibrutinib in Steroid-Refractory Chronic Graft-versus-Host Disease, a Single-Center Experience

Chronic graft-versus-host disease (cGVHD) is a leading cause of late morbidity and mortality after allogenic hematopoietic stem cell transplantation. Corticosteroid-based therapies are a mainstay of its initial treatment but there is no consensus in how to treat steroid-refractory cGVHD. Ibrutinib is a Bruton tyrosine kinase and IL-2-inducible kinase inhibitor thought to affect pathways driving cGVHD, and it was approved for the treatment of refractory cGVHD by the Food and Drug Administration (FDA) in August 2017 after a landmark phase 1b/2 study. It was the first medication approved for this indication, but how to best treat refractory cGVHD remains an open question, and there has been limited literature on ibrutinib after the FDA approval. This study sought to characterize the utilization and outcomes associated with ibrutinib use in cGVHD via a retrospective single-center study. Fifty-three patients were identified as having been treated with ibrutinib for cGVHD following FDA approval between September 1, 2017, and December 31, 2020, using an institutional data repository. Their records were reviewed for demographics, cGVHD characteristics, and outcomes. For the entire cohort, two-year overall survival was 76% (95% confidence interval [CI], 60% to 86%), with a median follow-up among survivors of 26 months (range, 1.3 to 39.5 months). However, the 2-year failure-free survival (FFS) after initiation of ibrutinib was 9% (95% CI, 2.6% to 20%), and the median FFS was 4.5 months (95% CI, 2.8 to 7.1 months). Events of FFS included treatment change due to lack of response or toxicity, malignant relapse, or non-treatment related mortality. At the time of this report, 11 patients (21%) remained on ibrutinib. At the time of the FFS event or last follow-up, 6 patients (12%) had a complete or partial response, 34 (64%) had stable disease, and 13 (25%) had progressive disease. Ibrutinib use was associated with no reduction in corticosteroid dose between ibrutinib initiation and FFS event or last follow-up (mean difference, 0.00; P = .98). The most frequently used noncorticosteroid cGVHD therapy after ibrutinib was ruxolitinib (n = 14; 33%). The most common adverse events associated with treatment discontinuation were infection (lung, skin, enterocolitis; n = 6), bleeding and bruising (hematoma, epistaxis, gastrointestinal bleed; n = 5), and muscle aches (n = 2). In a real-world setting, ibrutinib is associated with a modest response rate and FFS and its use in a narrower, more targeted patient population may be indicated.

O-233 Micronized progesterone plus dydrogesterone versus micronized progesterone alone for luteal phase support in frozen-thawed cycles: a prospective cohort study

Study question

Does the addition of oral dydrogesterone to vaginal progesterone as luteal phase support improve pregnancy outcomes during frozen embryo transfer (FET) cycles compared with vaginal progesterone alone?

Summary answer

Luteal phase support with oral dydrogesterone added to vaginal progesterone improves live birth rates and reduces miscarriage rates compared with vaginal progesterone alone.

What is known already

Progesterone is an important hormone that triggers secretory transformation of the endometrium to allow implantation of the embryo. During in vitro fertilization (IVF), exogenous progesterone is administered for luteal phase support. However, there is wide inter-individual variation in absorption of progesterone via the vaginal wall. Oral dydrogesterone is effective and well tolerated when used to provide luteal phase support after fresh embryo transfer. However, there are currently no data on the effectiveness of luteal phase support with the combination of dydrogesterone with vaginal micronized progesterone compared with vaginal micronized progesterone after FET.

Study design, size, duration

Prospective cohort study conducted at an academic infertility center in Vietnam from 26 June 2019 to 30 March 2020.

Participants/materials, setting, methods

We studied 1364 women undergoing IVF with FET. The luteal support regimen was either vaginal micronized progesterone 400 mg twice daily plus oral dydrogesterone 10 mg twice daily (second part of the study) or vaginal micronized progesterone 400 mg twice daily (first 4 months of the study). The primary endpoint was live birth after the first FET of the started cycle, with miscarriage &lt;12 weeks as one of the secondary endpoints.

Main results and the role of chance

The vaginal progesterone + dydrogesterone group and vaginal progesterone groups included 732 and 632 participants, respectively. Live birth rates were 46.3% versus 41.3%, respectively (rate ratio [RR] 1.12, 95% confidence interval [CI] 0.99–1.27, p = 0.06; multivariate analysis RR 1.30 (95% CI 1.01–1.68), p = 0.042), with a statistically significant lower rate of miscarriage at &lt; 12 weeks (3.4% vs 6.6%; RR 0.51, 95% CI 0.32–0.83; p = 0.009). Birth weight of both singletons (2971.0 ± 628.4 vs. 3118.8 ± 559.2 g; p = 0.004) and twins (2175.5 ± 494.8 vs. 2494.2 ± 584.7; p = 0.002) was significantly lower in the progesterone plus dydrogesterone versus progesterone group.

Limitations, reasons for caution

The study were the open-label design and the non-randomized nature of the sequential administration of study treatments. However, our systematic comparison of the two strategies was able to be performed much more rapidly than a conventional randomized controlled trial. In addition, the single ethnicity population limits external generalizability.

Wider implications of the findings

Oral dydrogesterone in addition to vaginal progesterone as luteal phase support in FET cycles can reduce the miscarriage rate and improve the live birth rate. Carefully planned prospective cohort studies with limited bias could be used as an alternative to randomized controlled clinical trials to inform clinical practice.

Trial registration number

NCT03998761

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

An approach to classifying occupational exposures to endocrine disrupting chemicals by sex hormone function using an expert judgment process

Endocrine disrupting chemicals (EDCs) are exogenous substances that interfere with the endocrine system and cause adverse effects. We aimed to classify the effects of 24 known EDCs, prevalent in certain occupations, according to four modes of action (estrogenic, antiestrogenic, androgenic, and/or antiandrogenic). A literature search, stratified into four types of literature was conducted (namely: national and international agency reports; review articles; primary studies; ToxCast^TM). The state of the evidence of each EDC on sex hormone function was summarized and reviewed by an expert panel. For each mode of action, the experts evaluated the likelihood of endocrine disruption in five categories: "No", "Unlikely", "Possibly", "Probably", and "Yes". Seven agents were categorized as "Yes," or having strong evidence for their effects on sex hormone function (antiandrogenic: lead, arsenic, butylbenzyl phthalate, dibutyl phthalate, dicyclohexyl phthalate; estrogenic: nonylphenol, bisphenol A). Nine agents were categorized as "Probable," or having probable evidence (antiandrogenic: bis(2-ethylhexyl)phthalate, nonylphenol, toluene, bisphenol A, diisononyl phthalate; androgenic: cadmium; estrogenic: copper, cadmium and; anti-estrogenic: lead). Two agents (arsenic, polychlorinated biphenyls) had opposing conclusions supporting both "probably" estrogenic and antiestrogenic effects. This synthesis will allow researchers to evaluate the health effects of selected EDCs with an added level of precision related to the mode of action.

Applying genome-wide CRISPR-Cas9 screens for therapeutic discovery in facioscapulohumeral muscular dystrophy

The emergence of CRISPR-Cas9 gene-editing technologies and genome-wide CRISPR-Cas9 libraries enables efficient unbiased genetic screening that can accelerate the process of therapeutic discovery for genetic disorders. Here, we demonstrate the utility of a genome-wide CRISPR-Cas9 loss-of-function library to identify therapeutic targets for facioscapulohumeral muscular dystrophy (FSHD), a genetically complex type of muscular dystrophy for which there is currently no treatment. In FSHD, both genetic and epigenetic changes lead to misexpression of DUX4, the FSHD causal gene that encodes the highly cytotoxic DUX4 protein. We performed a genome-wide CRISPR-Cas9 screen to identify genes whose loss-of-function conferred survival when DUX4 was expressed in muscle cells. Genes emerging from our screen illuminated a pathogenic link to the cellular hypoxia response, which was revealed to be the main driver of DUX4-induced cell death. Application of hypoxia signaling inhibitors resulted in increased DUX4 protein turnover and subsequent reduction of the cellular hypoxia response and cell death. In addition, these compounds proved successful in reducing FSHD disease biomarkers in patient myogenic lines, as well as improving structural and functional properties in two zebrafish models of FSHD. Our genome-wide perturbation of pathways affecting DUX4 expression has provided insight into key drivers of DUX4-induced pathogenesis and has identified existing compounds with potential therapeutic benefit for FSHD. Our experimental approach presents an accelerated paradigm toward mechanistic understanding and therapeutic discovery of a complex genetic disease, which may be translatable to other diseases with well-established phenotypic selection assays.

451 THE BEST MARKER FOR COGNITION—RELATIVE HANDGRIP STRENGTH, ASYMMETRY OR WEAKNESS?

Introduction

Handgrip strength (HGS) is increasingly used to estimate overall muscle strength. Association between low HGS and cognitive decline has been well documented. Recently, McGrath’s team elucidated a new dimension of HGS asymmetry with important implications on physical and cognitive limitations. It is unclear if these effects can be generalised. The Asian working group for sarcopenia (AWGS) has called for ‘special considerations’ due to ‘anthropometric and cultural or lifestyle-related differences’6. Hence, we aim to investigate if HGS asymmetry is associated with cognition in Asians.

Methodology

We defined sarcopenia by AWGS consensus: HGS &lt;28 kg for men; &lt;18 kg for women. Asymmetry was HGS &gt;10% stronger on either hand; relative HGS was HGS adjusted for BMI. Low cognitive function was defined as MMSE&lt;26. We compared weakness alone, any HGS asymmetry or relative HGS alone and combination of weakness and HGS asymmetry or relative HGS asymmetry. Each model was adjusted for demographic characteristics, hand dominance, obesity, frailty, physical activity, depression and perceived health status.

Results

738 Asian subjects participated. Mean age 70.8 ± 0.2 years, 45.1% males, 82.5% Chinese. More than 50% have multimorbidity. 5.4% were frail. Mean BMI 24.4 ± 0.1 kg/m2. Mean HGS 22.6 ± 0.3. 93 (12.7%) had symmetrical HGS and not weak, 59 (7.8%) asymmetrical and not weak, 321 (43.6%) symmetrical and weak, 265 (35.9%) asymmetrical and weak. Mean MMSE scores for weakness alone, asymmetry alone and combined weakness and asymmetry are 26.6 ± 0.1, 26.8 ± 0.2 and 26.5 ± 0.2 respectively. HGS asymmetry alone was not associated with better cognitive function OR 0.66 (95%CI: 0.30–1.44). Combined asymmetry and weakness was non-significantly linked to worse cognition OR 2.14 (95%CI: 0.79–5.82). We found relative HGS to be protective for cognitive decline, OR 0.31 (95%CI: 0.12–0.78, p = 0.012).

Conclusion

Our study highlights the impact of ethnicity in sarcopenia research. Our population shows association of relative HGS with cognition. Further longitudinal studies are needed.