Neuronal rhythmicity and cortical arousal in a mouse model of absence epilepsy.

OBJECTIVES: Absence seizures impair psychosocial function, yet their detailed neuronal basis remains unknown. Recent work in a rat model suggests that cortical arousal state changes prior to seizures and that single neurons show diverse firing patterns during seizures. Our aim was to extend these investigations to a mouse model with studies of neuronal activity and arousal state to facilitate future fundamental investigations of absence epilepsy. METHODS: We performed in vivo extracellular single unit recordings on awake head-fixed C3H/HeJ mice. Mice were implanted with tripolar electrodes for cortical electroencephalography (EEG). Extracellular single unit recordings were obtained with glass micropipettes in the somatosensory barrel cortex, while animals ambulated freely on a running wheel. Signals were digitized and analyzed during seizures and at baseline. RESULTS: Neuronal activity was recorded from 36 cortical neurons in 19 mice while EEG showed characteristic 7-8 Hz spike-wave discharges. Different single neurons showed distinct firing patterns during seizures, but the overall mean population neuronal firing rate during seizures was no different from pre-seizure baseline. However, the rhythmicity of neuronal firing during seizures was significantly increased (p < 0.001). In addition, beginning 10s prior to seizure initiation, we observed a progressive decrease in cortical high frequency (>40 Hz) EEG and an increase in lower frequency (1-39 Hz) activity suggesting decreased arousal state. SIGNIFICANCE: We found that the awake head-fixed C3H/HeJ mouse model demonstrated rhythmic neuronal firing during seizures, and a decreased cortical arousal state prior to seizure onset. Unlike the rat model we did not observe an overall decrease in neuronal firing during seizures. Similarities and differences across species strengthen the ability to investigate fundamental key mechanisms. Future work in the mouse model will identify the molecular basis of neurons with different firing patterns, their role in seizure initiation and behavioral deficits, with ultimate translation to human absence epilepsy.

UV arrows descend from above: lessons from a mass media campaign to improve sun protection behaviours among young adults.

OBJECTIVE: More than 95% of melanomas in Australia are caused by UV radiation from the sun. Young adults are particularly at risk, with 18-24-year-olds spending more time in the sun and protecting their skin less than older adults. A new mass media campaign was delivered in New South Wales, Australia, to motivate this hard-to-reach group to protect their skin from harmful UV radiation. This paper shares learnings from this campaign for public health educators working across diverse fields. PROGRAM: Guided by audience research and testing, the campaign combined fear-based and self-efficacy messaging. UV radiation was portrayed as arrows descending from the sky, transforming it into a visible and ever-present threat. High-reach channels such as cinema, outdoor advertising, online videos, audio apps and social media were used to reach the audience. METHODS: The campaign was evaluated through an online tracking survey (n = 750, 18-24-year-olds) measuring prompted recognition, message take-out, key diagnostics, and self-reported sun protection intentions and behaviours. RESULTS: The evaluation found that 57% of survey participants recognised the campaign when prompted. Among those that recognised the campaign, 76% said they had used sun protection when outdoors over the summer campaign period (vs 64% of non-recognisers, p < 0.05), and 45% said they had adopted at least three of the five sun protection behaviours (Slip, Slop, Slap, Seek and Slide) 'always' or 'often' (vs. 36% of non-recognisers, p < 0.05). LESSONS LEARNT: A mass-media campaign that aimed to elicit emotional (fear) and cognitive (perceived efficacy) responses and which drew upon social and heuristic cues was associated with greater self-reported sun protection among the target audience. Delivering a combination of message strategies simultaneously within a campaign tailored to young adults may be more effective than adopting a more singular focus.

Protocol for evaluating the fitness for purpose of an artificial intelligence product for radiology reporting in the BreastScreen New South Wales breast cancer screening programme.

INTRODUCTION: Radiologist shortages threaten the sustainability of breast cancer screening programmes. Artificial intelligence (AI) products that can interpret mammograms could mitigate this risk. While previous studies have suggested this technology has accuracy comparable to radiologists most have been limited by using 'enriched' datasets and/or not considering the interaction between the algorithm and human readers. This study will address these limitations by comparing the accuracy of a workflow using AI alongside radiologists on a large consecutive cohort of examinations from a breast cancer screening programme. The study will combine the strengths of a large retrospective design with the benefit of prospective data collection. It will test this technology without risk to screening programme participants nor the need to wait for follow-up data. With a sample of 2 years of consecutive screening examinations, it is likely the largest test of this technology to date. The study will help determine whether this technology can safely be introduced into the BreastScreen New South Wales (NSW) population-based screening programme to address radiology workforce risks without compromising cancer detection rates or increasing false-positive recalls. METHODS AND ANALYSIS: A retrospective, consecutive cohort of digital mammography screens from 658 207 examinations from BreastScreen NSW will be reinterpreted by the Lunit Insight MMG AI product. The cohort includes 4383 screen-detected and 1171 interval cancers. The results will be compared with radiologist single reading and the AI results will also be used to replace the second reader in a double-reading model. New adjudication reading will be performed where the AI disagrees with the first reader. Recall rates and cancer detection rates of combined AI-radiologist reading will be compared with the rates obtained at the time of screening. ETHICS AND DISSEMINATION: This study has ethical approval from the NSW Health Population Health Services Research Ethics Committee (2022/ETH02397). Findings will be published in peer-reviewed journals and presented at conferences. The findings of this evaluation will be provided to programme managers, governance bodies and other stakeholders in Australian breast cancer screening programmes.

Offline Two-Dimensional Liquid Chromatography-Mass Spectrometry for Deep Annotation of the Fecal Metabolome Following Fecal Microbiota Transplantation.

Biological interpretation of untargeted LC-MS-based metabolomics data depends on accurate compound identification, but current techniques fall short of identifying most features that can be detected. The human fecal metabolome is complex, variable, incompletely annotated, and serves as an ideal matrix to evaluate novel compound identification methods. We devised an experimental strategy for compound annotation using multidimensional chromatography and semiautomated feature alignment and applied these methods to study the fecal metabolome in the context of fecal microbiota transplantation (FMT) for recurrent C. difficile infection. Pooled fecal samples were fractionated using semipreparative liquid chromatography and analyzed by an orthogonal LC-MS/MS method. The resulting spectra were searched against commercial, public, and local spectral libraries, and annotations were vetted using retention time alignment and prediction. Multidimensional chromatography yielded more than a 2-fold improvement in identified compounds compared to conventional LC-MS/MS and successfully identified several rare and previously unreported compounds, including novel fatty-acid conjugated bile acid species. Using an automated software-based feature alignment strategy, most metabolites identified by the new approach could be matched to features that were detected but not identified in single-dimensional LC-MS/MS data. Overall, our approach represents a powerful strategy to enhance compound identification and biological insight from untargeted metabolomics data.

Metagenomic, metabolomic, and lipidomic shifts associated with fecal microbiota transplantation for recurrent Clostridioides difficile infection.

Recurrent C. difficile infection (rCDI) is an urgent public health threat for which the last resort and lifesaving treatment is a fecal microbiota transplant (FMT). However, the exact mechanisms which mediate a successful FMT are not well understood. Here we use longitudinal stool samples collected from patients undergoing FMT to evaluate changes in the microbiome, metabolome, and lipidome after successful FMTs. We show changes in the abundance of many lipids, specifically acylcarnitines and bile acids, in response to FMT. These changes correlate with Enterobacteriaceae, which encode carnitine metabolism genes, and Lachnospiraceae, which encode bile salt hydrolases and baiA genes. LC-IMS-MS revealed a shift from microbial conjugation of primary bile acids pre-FMT to secondary bile acids post-FMT. Here we define the structural and functional changes in successful FMTs. This information will help guide targeted Live Biotherapeutic Product development for the treatment of rCDI and other intestinal diseases.

Gastrointestinal-isolated Distress is Common in Alpha-gal Allergic Patients on Mammalian Meat Challenge.

BACKGROUND AND AIMS: Alpha-gal allergy causes a delayed reaction to mammalian meats and has been reported worldwide. Patients with the allergy may present with isolated gastrointestinal (GI) symptoms, but this phenotype is poorly understood. METHODS: We pooled and analyzed symptoms and demographics of patients from two prospective cohorts of patients with a diagnosis of alpha-gal allergy who reacted after eating mammalian meat under observation. We compared the characteristics of patients who demonstrated GI-isolated symptoms on a challenge with those who exhibited symptoms outside the GI tract (skin, respiratory, and circulatory). RESULTS: Among the 91 children and adult alpha-gal allergic patients who exhibited symptoms after oral challenge with mammalian meat, 72.5% experienced GI distress with one or more GI symptoms, which was the most frequent class of symptoms, compared with skin changes in 57.1% and respiratory distress in 5.5%. The most common GI symptoms were abdominal pain (71%) and vomiting (22.0%). GI-isolated symptoms occurred in 37 patients (40.7%) who reacted, and those patients reacted more quickly than patients who exhibited systemic symptoms (median onset of symptoms in GI-isolated group 90 min vs 120 min) and were more likely to be children than adults (relative risk=1.94, 95% CI: 1.04-3.63). CONCLUSIONS: Isolated-GI distress occurred in 4 in every 10 alpha-gal allergic individuals who developed symptoms on oral food challenge with mammalian meat. Alpha-gal allergic patients, particularly children, may exhibit GI distress alone, and adult and pediatric gastroenterologists should be aware of the diagnosis and management of the allergy.

Using Multidimensional Separations to Distinguish Isomeric Amino Acid-Bile Acid Conjugates and Assess Their Presence and Perturbations in Model Systems.

Bile acids play key roles in nutrient uptake, inflammation, signaling, and microbiome composition. While previous bile acid analyses have primarily focused on profiling 5 canonical primary and secondary bile acids and their glycine and taurine amino acid-bile acid (AA-BA) conjugates, recent studies suggest that many other microbial conjugated bile acids (or MCBAs) exist. MCBAs are produced by the gut microbiota and serve as biomarkers, providing information about early disease onset and gut health. Here we analyzed 8 core bile acids synthetically conjugated with 22 proteinogenic and nonproteogenic amino acids totaling 176 MCBAs. Since many of the conjugates were isomeric and only 42 different m/z values resulted from the 176 MCBAs, a platform coupling liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) was used for their separation. Their molecular characteristics were then used to create an in-house extended bile acid library for a combined total of 182 unique compounds. Additionally, ∼250 rare bile acid extracts were also assessed to provide additional resources for bile acid profiling and identification. This library was then applied to healthy mice dosed with antibiotics and humans having fecal microbiota transplantation (FMT) to assess the MCBA presence and changes in the gut before and after each perturbation.

Offline Two-dimensional Liquid Chromatography-Mass Spectrometry for Deep Annotation of the Fecal Metabolome.

Compound identification is an essential task in the workflow of untargeted metabolomics since the interpretation of the data in a biological context depends on the correct assignment of chemical identities to the features it contains. Current techniques fall short of identifying all or even most observable features in untargeted metabolomics data, even after rigorous data cleaning approaches to remove degenerate features are applied. Hence, new strategies are required to annotate the metabolome more deeply and accurately. The human fecal metabolome, which is the focus of substantial biomedical interest, is a more complex, more variable, yet lesser-investigated sample matrix compared to widely studied sample types like human plasma. This manuscript describes a novel experimental strategy using multidimensional chromatography to facilitate compound identification in untargeted metabolomics. Pooled fecal metabolite extract samples were fractionated using offline semi-preparative liquid chromatography. The resulting fractions were analyzed by an orthogonal LC-MS/MS method, and the data were searched against commercial, public, and local spectral libraries. Multidimensional chromatography yielded more than a 3-fold improvement in identified compounds compared to the typical single-dimensional LC-MS/MS approach and successfully identified several rare and novel compounds, including atypical conjugated bile acid species. Most features identified by the new approach could be matched to features that were detectable but not identifiable in the original single-dimension LC-MS data. Overall, our approach represents a powerful strategy for deeper annotation of the metabolome that can be implemented with commercially-available instrumentation, and should apply to any dataset requiring deeper annotation of the metabolome.

Exploring pre-implementation perceptions of integrated care in a university setting.

Objective: To examine providers' perceptions of integrated care prior to the merger of a university's student health center and counseling services. Participants: Seventeen providers across student health services (n = 9) and counseling (n = 8) agreed to participate in the qualitative study. Method: Semi-structured individual interviews that focused on the perceived benefits and challenges of the merger were conducted in December 2019. Following the interviews, a thematic analysis was completed. Results: The perceived benefits noted by providers centered on the ability of an interdisciplinary team to improve the coordination of, access to, and quality of care delivered to students. However, more anticipated challenges were reported by providers (e.g., differences in training and care protocols, losing one's autonomy as a provider). Conclusions: This qualitative study provides a more in-depth analysis of providers' perceptions of integrated care prior to implementation in a university setting and may have implications for model adoption.

AGA Clinical Practice Update on Alpha-Gal Syndrome for the GI Clinician: Commentary.

DESCRIPTION: Alpha-gal syndrome is an emerging allergy first described in the early 2000s. The allergy can cause anaphylaxis, gastrointestinal (GI) symptoms, and skin changes one to several hours after ingestion of mammalian products. A GI phenotype that is increasingly recognized manifests with nonspecific symptoms like abdominal pain, diarrhea, nausea or vomiting without predominant skin, respiratory or circulatory symptoms. Though the syndrome has been reported on all continents except Antarctica, in the United States most reports are within the range of the Lone Star tick, extending from New York and Iowa to Texas and Florida. The purpose of this AGA Clinical Practice Update (CPU) Commentary is to increase awareness among gastroenterologists about the presentation and management of alpha-gal syndrome. METHODS: This CPU commentary was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors. Formal ratings regarding the quality of evidence or strength of the presented considerations were not included since systematic reviews were not performed.

Bile salt hydrolases shape the bile acid landscape and restrict Clostridioides difficile growth in the murine gut.

Bile acids (BAs) mediate the crosstalk between human and microbial cells and influence diseases including Clostridioides difficile infection (CDI). While bile salt hydrolases (BSHs) shape the BA pool by deconjugating conjugated BAs, the basis for their substrate selectivity and impact on C. difficile remain elusive. Here we survey the diversity of BSHs in the gut commensals Lactobacillaceae, which are commonly used as probiotics, and other members of the human gut microbiome. We structurally pinpoint a loop that predicts BSH preferences for either glycine or taurine substrates. BSHs with varying specificities were shown to restrict C. difficile spore germination and growth in vitro and colonization in pre-clinical in vivo models of CDI. Furthermore, BSHs reshape the pool of microbial conjugated bile acids (MCBAs) in the murine gut, and these MCBAs can further restrict C. difficile virulence in vitro. The recognition of conjugated BAs by BSHs defines the resulting BA pool, including the expansive MCBAs. This work provides insights into the structural basis of BSH mechanisms that shape the BA landscape and promote colonization resistance against C. difficile.

Alpha-Gal Sensitization in a US Screening Population Is Not Associated With a Decreased Meat Intake or Gastrointestinal Symptoms.

INTRODUCTION: Patients with alpha-gal syndrome, a delayed reaction to mammalian meat, can present with isolated gastrointestinal (GI) symptoms. We aimed to estimate the frequency of alpha-gal sensitization in a Southeastern US population and determine the association between sensitization and mammalian product dietary intake or GI symptoms. METHODS: We performed a cross-sectional study of participants who underwent a screening colonoscopy at our center between 2013 and 2015. We quantified serum alpha-gal immunoglobulin E antibodies in participants who were prospectively enrolled at screening colonoscopy and compared diet intake and lower GI symptoms reported in standardized questionnaires among those with elevated versus no alpha-gal IgE antibodies. RESULTS: Alpha-gal IgE antibodies were common-31.4% of screening colonoscopy participants (127 of 404) had elevated serum alpha-gal IgE >0.1 kU/L. Alpha-gal-sensitized participants endorsed similar rates of abdominal pain compared with those without alpha-gal antibodies (33% vs 38%, adjusted odds ratio 0.9, 95% confidence interval 0.7-1.3). Mammalian meat consumption did not differ based on alpha-gal sensitization status (average 1.43 servings/d in sensitized subjects vs 1.50 in alpha-gal IgE-negative subjects, P = 0.9). Alpha-gal-sensitized participants with levels ≥10 (n = 21) were overrepresented in the lowest quartiles of mammalian meat consumption, but not among those with GI symptoms in general. Participants with high alpha-gal antibody levels >2 kU/L (n = 45) or ≥10 U/L (n = 21) did not have a reduced mean daily mammalian meat intake compared with seronegative people. DISCUSSION: Elevated alpha-gal IgE antibodies were common and not associated with a reduced mammalian meat intake, abdominal pain, or diarrhea. Seropositivity did not predict symptomatic alpha-gal sensitization in this general screening population. Other host factors likely contribute to the phenotypic expression of alpha-gal syndrome.

Walk before you run: Feasibility challenges and lessons learned from the PROCLAIM study, a multicenter randomized controlled trial of misoprostol for prevention of recurrent Clostridioides difficile during COVID-19.

We analyzed our challenging experience with a randomized controlled trial of misoprostol for prevention of recurrent C. difficile. Despite careful prescreening and thoughtful protocol modifications to facilitate enrollment, we closed the study early after enrolling just 7 participants over 3 years. We share lessons learned, noting the importance of feasibility studies, inclusion of biomarker outcomes, and dissemination of such findings to inform future research design and implementation successes.

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.

Examining Patient and Provider Experiences with Integrated Care at a Community Health Clinic.

The purpose of this study was to examine patient and provider experiences of integrated behavioral health care at a Federally Qualified Health Center (FQHC). Using a mixed methodology design, both patients (n = 186) and providers (n = 17) completed a survey regarding satisfaction with care and the extent of integration at the clinic, as well as attended a focus group or interview (n = 11 patients; n = 12 providers) regarding their satisfaction and experiences. Both patients and providers found integration to be acceptable and satisfactory and the integration of services among different health care providers occurred fairly regularly. Themes from the provider and patient interviews/focus groups highlighted both positive aspects of the integration and specific challenges within the clinic. This more nuanced perspective of integration both replicates and extends upon previous research regarding satisfaction with integrated care and emphasizes the complexities and challenges of integration within community health clinics.

Family Stool Donation Predicts Failure of Fecal Microbiota Transplant for Clostridioides difficile Infection.

Background and Aims: Fecal microbiota transplant (FMT) via colonoscopy is highly effective treatment for Clostridioides difficile infection (CDI). We aimed to determine baseline patient characteristics that predict failure to respond to colonoscopy-based FMT. Methods: We evaluated adult patients who received FMT for CDI not responding to standard therapies at a single tertiary center between 2014 and 2018 in this retrospective cohort study. We defined clinical success as formed stool or C difficile-negative diarrhea at 2 months after FMT. If patients required a second FMT, follow-up was extended 2 months after repeat infusion. We performed multivariate logistic regression and a random forest model to identify variables predictive of response to FMT. Results: Clinical success was attained in 87.3% of 103 patients who underwent FMT for CDI. In the multivariate model, the odds of FMT failure for family donation compared with stool bank were odds ratio 4.13 (1.00-7.01 P = .049). Diarrhea while taking anti-CDI antibiotics was common (37.8% of patients) and did not predict failure (odds ratio 0.64, 0.19-2.11 P = .46) in the univariate model. A machine learning model to predict response using clinical factors only achieved a sensitivity of 70%, specificity of 77%, and negative predictive value of 96%. Conclusion: Colonoscopy-based FMT was highly effective for CDI, even in a population where immunosuppression and proton pump inhibitor use were common. Family stool donation was associated with FMT failure, compared with the use of a stool bank. The study suggests that the use of a stool bank may not only improve access to FMT but also its efficacy.