Trends in gastric surgery operative experience among general surgery residents in the United States: A nationwide retrospective analysis

BACKGROUND

Gastric surgery is a crucial component of general surgery training. However, there is a paucity of high-quality data on operative volume and the diversity of surgical procedures that general surgery residents are exposed to.

METHODS

We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from the American College of Graduate Medical Education-accredited program from 2009 to 2022. Data on the mean number of gastric procedures, including the mean in each subcategory, were retrieved. A Mann-Kendall trend test was used to investigate trends in operative volume.

RESULTS

Between 2009 and 2022, the mean overall logged gastric procedures rose significantly (τ = 0.722, P < .001) from 36.2 in 2009 to 49.2 in 2022 (35.9% increase). The most substantial growth was seen in laparoscopic gastric reduction for morbid obesity (mean 1.9 in 2017 to 19 in 2022; τ = 0.670, P = .009). A statistically significant increase was also seen in laparoscopic partial gastric resections, repair of gastric perforation, and "other major stomach procedures" (P < .05 for all comparisons). Open gastrostomy, open partial gastric resections, and open vagotomy all significantly decreased (P < .05 for all comparisons). There was no significant change in the volume of laparoscopic gastrectomy, total gastric resections, and non-laparoscopic gastric reductions for morbid obesity (P > .05 for all comparisons).

CONCLUSION

There has been a substantial increase in the volume of gastric surgery during residency over the past 14 years, driven mainly by an increase in laparoscopic gastric reduction. However, there may still be a need for further gastric surgical training to ensure well-rounded general surgeons.

Operative Experience of Esophageal Surgery among General Surgery Residents in the United States: An Analysis of ACGME Operative Case Logs

INTRODUCTION

Esophageal surgery is an essential component of general surgery training and encompasses several types of cases that are logged by general surgery residents. There is a scarcity of data on the quality and volume of esophageal surgery experience during surgical residency in the United States. We analyzed trends for 9 different esophageal procedure categories logged by residents in the United States, with the aim to identify areas for improvement in training.

METHODS

We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from programs accredited by the ACGME over a fourteen-year period from 2009 to 2023. Data on mean esophageal cases reported by graduates, including mean in each procedure subcategory were retrieved. Cases were categorized as either surgeon chief or surgeon junior for each procedure category. Mann-Kendall trend test was used to obtain tau statistics and p-value for trends in mean operative surgical volume for the total number of cases in each operative category over the study period. Trends in surgeon chief and surgeon junior cases were also investigated for each operative category.

RESULTS

The mean number of all esophageal procedures performed per resident during their training increased significantly from 10.5 in 2009 to 16 in 2022 (τ = 0.833, p < 0.001). This trend observed among all esophageal procedures during this 14-year study can be largely attributed to the steady increase in the number and proportion of laparoscopic esophageal antireflux procedures performed (τ = 0.950, p < 0.001). Additionally, esophagectomy procedures had a statistically significant, but modest, increase during the study period (τ = 0.505, p = 0.023), from a mean of 1 case during training in 2009 to a peak of 1.3 in 2020. Although the general trend of esophagus procedures increased during the study period, most categories (7 out of 9) either decreased or did not significantly change. Esophagogastrectomy volume decreased significantly by 30%, from 1 per resident during their training in 2009 to 0.7 in 2022 (τ = -0.510, p = 0.018), esophageal diverticulectomy procedures decreased by 50% from 0.2 to 0.1 (τ = -0.609, p = 0.009), and operations for esophageal stenosis decreased by 75% from 0.4 to 0.1 (τ = -0.734, p = 0.001). Mean number of esophageal bypasses (τ = -0.128, p = 0.584), repair of perforated esophageal disease (τ = -0.333, p = 0.156), and other major esophagus procedures (τ = 0.416, p = 0.063) did not significantly change.

CONCLUSION

The operative volume of esophageal surgery that general surgery residents in the United States are exposed to has significantly risen over the past 14 years, largely driven by the increase in laparoscopic antireflux procedures. However, given the recent advances and the resultant heterogeneity in both esophageal surgery, the increase in resident operative volume is still inadequate to ensure the training of safe and adept esophageal surgeons, necessitating postresidency specialized training for trainees interested in esophageal surgery.

New insights into aging in LiNiO2 cathodes from high resolution paramagnetic NMR spectroscopy

Bulk degradation processes are examined in the LiNiO2 cathode using high resolution solid-state NMR, combined with magnetometry and X-ray diffraction. Capacity decay is correlated with bulk heterogeneity, whereby multiple structural domains coexist in the charged state, and the Li content and electrochemical activity of these domains is unraveled for the first time.

Barriers and enablers to people-centred viral hepatitis care in Vietnam and the Philippines: Results of a patient journey mapping study

In Vietnam and the Philippines, viral hepatitis is the leading cause of cirrhosis and liver cancer. This study aims to understand the barriers and enablers of people receiving care for hepatitis B and C to support both countries' efforts to eliminate viral hepatitis as a public health threat by 2030. Retrospective, semi-structured interviews were conducted with a purposive, quota-based sample of 63 people living with hepatitis B or C in one province of Vietnam and one region of the Philippines. A rapid deductive approach to thematic analysis produced key findings among the three phases of care: (1) pre-awareness and testing, (2) linkage and treatment initiation and (3) ongoing treatment and recovery. The research found that participants followed five typical journeys, from a variety of entry points. Barriers during the pre-awareness and testing phase included limited awareness about hepatitis and its management, stigma and psychological impacts. Enablers included being familiar with the health system and/or patients benefiting from social connections within the health systems. During the linkage and treatment initiation phase, barriers included difficult physical access, complex navigation and inadequate counselling. In this phase, family support emerged as a critical enabler. During the ongoing treatment and recovery phase, the cost of care and socially and culturally informed perceptions of the disease and medication use were both barriers and enablers. Exploring peoples' journeys with hepatitis B and C in Vietnam and the Philippines revealed many similarities despite the different cultural and health system contexts. Insights from this study may help generate a contextualized, people-centred evidence base to inform the design and improvement of primary care services for hepatitis in both research sites.

Demonstration of a 1 TW peak power, joule-level ultrashort Tm:YLF laser

We report on the demonstration of a diode-pumped, Tm:YLF-based, chirped pulse amplification laser system operating at λ ≈ 1.9 µm that produces amplified pulse energies exceeding 1.5 J using a single 8-pass power amplifier. The amplified pulses are subsequently compressed to sub-300 fs durations by a diffraction grating pair, producing record >1 TW peak power pulses. To the best of our knowledge, this is the highest peak power demonstrated for any solid-state, near-2 µm laser architecture and illustrates the potential of Tm:YLF for the next generation of high-power, diode-pumped ultrashort lasers.

Identifying Community Safety and Policy-Based Injury Prevention Opportunities to Reduce Golf Cart Injuries

BACKGROUND

In small US communities, golf cart utilization has become increasingly more common. In the past 3 years, the incidence and severity of pediatric golf cart-related trauma evaluated at our trauma center has noticeably increased. Thus, the aim of this study was to analyze trends, identify risk and protective factors, and provide community-level recommendations to improve golf cart safety for children in a coastal community.

METHODS

A retrospective cross-sectional study of our institutional trauma registry was performed. The registry was queried for golf cart injuries between 2012 -2022. Demographics, accident details, hospital course and outcomes were reviewed. Data analysis involved quantitative statistics. Incident locations were mapped, including additional data from the County emergency medical service. Additionally, customer education at four prominent golf rental shops was observed.

RESULTS

Annual golf cart-related traumas doubled starting in 2020. Of 235 total patients, 105 (46%) were children. Median age was 11.5 years (range 2-17). 55% were female and 67% were non-Hispanic White. 80% were out-of-county residents. The most common injury location was extremity (56%). Median ISS was 4, and 3% died. Only 10% of children were restrained. 41% were ejected and most (84%) were front-facing passengers. Ejection was associated with more severe injury (OR 4.13, p = 0.01). Most injuries occurred during 5-10 pm (47%), weekends and summertime. Nighttime injuries were more severe than daytime (p = 0.04). A hotspot of crashes was identified in a zone where golf carts were restricted. Rental stores provided education on seat belt use, car seat use for infants, and off-limit zones. However, rules were not enforced.

CONCLUSION

Our results inform the following golf cart injury prevention opportunities: raising awareness of injury risks to children in high-tourist areas, partnering with rental stores to enforce rules, improving signage, adding protected lanes, and adopting a no nighttime operation policy.

LEVEL OF EVIDENCE

IV.

Embedding viral hepatitis into primary healthcare: results of a strategic landscape analysis in Vietnam and the Philippines

Chronic viral hepatitis is a significant public health concern in the Western Pacific, including in Vietnam and the Philippines. To accelerate progress toward meeting the 2030 elimination goals, the World Health Organization (WHO) encourages countries to adopt an integrated, people-centered health sector response to hepatitis, grounded in Primary Health Care (PHC). A review of the academic and grey literature, along with policy documents, was conducted to describe the national health system and PHC response to hepatitis B and C in Vietnam and the Philippines. Information was analyzed against the four strategic levers of the WHO Operational Framework for PHC to identify challenges and opportunities. The findings suggest that both countries have relatively robust policy frameworks, with some room for improvement. Vietnam may have stronger political commitment and funding than the Philippines, while the Philippines appears to be stronger in community engagement. Both countries share challenges and opportunities for learning to actualize viral hepatitis elimination utilizing a PHC approach.

Can my surgeon scope? Trends in endoscopy training volume and experience among general surgery residents in the United States: a nationwide analysis

INTRODUCTION

Endoscopy is a major part of surgical training. Accreditation Council for Graduate Medical Education (ACGME) has set standards regarding the minimum volume of endoscopy cases required for graduation. However, there is paucity of high-quality data on the number of cases that most surgical graduates perform.

METHODS

We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from ACGME-accredited programs from 2010 to 2023. Data on mean number of endoscopy cases, including mean in each subcategory, were retrieved. Mann-Kendall trend test was used to investigate trends in endoscopy experience.

RESULTS

Between 2010 and 2023, the mean overall endoscopy procedures per resident remained stable, with 129.5 in 2010 and 132.1 in 2023 (t = 0.429; p-value = 0.037). The majority of these cases were performed as surgeon junior (76.6% in 2010; 80.9% in 2023), while the remaining cases were logged as surgeon chief. The most substantial contribution to the overall volume was from flexible colonoscopy (mean: 64.1 in 2010 and 67.2 in 2023). The volume for colonoscopy remained fairly stable (t = 0.429; p-value = 0.036). This was followed by esophagogastroduodenoscopy (mean: 35.3 in 2010 and 35.5 in 2023), which saw a significant increase in volume (t = 0.890; p-value ≤ 0.001). There was a significant increase in the number of overall upper endoscopic procedures (t = 0.791; p-value ≤ 0.001), while lower endoscopic procedures did not change significantly (t = 0.319; p-value = 0.125). The procedural volume for endoscopic retrograde cholangiography, sigmoidoscopy, cystoscopy/ureteroscopy, laryngoscopy, and bronchoscopy decreased significantly (p-value < 0.05 for all).

CONCLUSION

The overall endoscopy volume for general surgery residents has largely remained stable, with a minor increase in esophagogastroduodenoscopy and no change in colonoscopy. Future research should investigate whether simulation-based exercises can bridge the gap between procedural volume and learning curve requirements for endoscopy.

The Efficacy of Metformin as a Therapeutic Agent in the Treatment of Acne Vulgaris: A Systematic Review

A large portion of the world's population is affected by acne vulgaris (AV), with many of these individuals being adolescents. The underlying mechanism of AV is hyperkeratinization and Cutibacterium acnes infection of the pilosebaceous follicle secondary to excessive stimulation of sebaceous glands by androgens. Metformin is a biguanide medication primarily used in efforts to lower patients' sugar levels in the management of type 2 diabetes. It has been proven to reduce levels of circulating androgens in patients with insulin resistance, indicating its potential for treating AV. A search strategy was developed and performed using the databases Ovid Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Controlled Register of Trials (CENTRAL), and Web of Science. The keywords "metformin" and "acne" were searched, along with related Medical Subject Headings (MeSH) and other subject headings. Studies that met the inclusion criteria were controlled trials, published after 2010, and in the English language. Participants with and without comorbidities such as polycystic ovary syndrome (PCOS) were considered. Two independent reviewers screened studies based on predefined criteria and extracted data from each study, which were quantitatively combined. A total of 15 studies were included in this systematic review. Across the 15 studies, there were 1,046 participants, with 13 studies looking exclusively at women with PCOS. Of the remaining two studies, one examined males with altered metabolic profiles, while the other included men and women with moderate AV. Notable risks of bias included studies that did not exclusively state the blindness of the study. Of the studies that were examined, 13 showed that metformin reduces AV, with seven studies showing statistical significance. Acne vulgaris is an inflammatory condition that has plagued patients for years due to the limited treatment options available. The hyperglycemic medication metformin, used in the management of type 2 diabetes, is being explored as a novel therapeutic that can possibly be repurposed for the treatment of AV. The use of metformin in AV is hypothesized to disrupt the proposed linkage between insulin resistance and AV proliferation. This proposed research could offer physicians a new option for the treatment of AV as well as render an alternative AV treatment for patients.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Biatrial arrhythmogenic substrate in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND

Atrial fibrillation (AF) in patients with hypertrophic obstructive cardiomyopathy (HOCM) may be caused by a primary atrial myopathy. Whether HOCM-related atrial myopathy affects mainly electrophysiological properties of the left atrium (LA) or also the right atrium (RA) has never been investigated.

OBJECTIVE

The purpose of this study was to characterize atrial conduction and explore differences in the prevalence of conduction disorders, potential fractionation, and low-voltage areas (LVAs) between the RA and LA during sinus rhythm (SR) as indicators of potential arrhythmogenic areas.

METHODS

Intraoperative epicardial mapping of both atria during SR was performed in 15 HOCM patients (age 50 ± 12 years). Conduction delay (CD) and conductin block (CB), unipolar potential characteristics (voltages, fractionation), and LVA were quantified.

RESULTS

Conduction disorders and LVA were found scattered throughout both atria in all patients and did not differ between the RA and LA (CD: 2.9% [1.9%-3.6%] vs 2.6% [2.1%-6.4%], P = .541; CB: 1.7% [0.9%-3.1%] vs 1.5% [0.5%-2.8%], P = .600; LVA: 4.7% [1.6%-7.7%] vs 2.9% [2.1%-7.1%], P = .793). Compared to the RA, unipolar voltages of single potentials (SPs) and fractionated potentials (FPs) were higher in the LA (SP: P75 7.3 mV vs 10.9 mV; FP: P75 2.0 mV vs 3.7 mV). FP contained low-voltage components in only 18% of all LA sites compared to 36% of all RA sites.

CONCLUSION

In patients with HOCM, conduction disorders, LVA, and FP are equally present in both atria, supporting the hypothesis of a primary atrial myopathy. Conceptually, the presence of a biatrial substrate and high-voltage FP may contribute to failure of ablative therapy of atrial tachyarrhythmias in this population.

A Critical Interpretive Synthesis of the Role of Arecoline in Oral Carcinogenesis: Is the Local Cholinergic Axis a Missing Link in Disease Pathophysiology?

Arecoline is the primary active carcinogen found in areca nut and has been implicated in the pathogenesis of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). For this study, we conducted a stepwise review process by combining iterative scoping reviews with a post hoc search, with the aim of identifying the specific mechanisms by which arecoline initiates and promotes oral carcinogenesis. Our initial search allowed us to define the current trends and patterns in the pathophysiology of arecoline-induced OSF and OSCC, which include the induction of cell proliferation, facilitation of invasion, adhesion, and migration, increased collagen deposition and fibrosis, imbalance in immune and inflammatory mechanisms, and genotoxicity. Key molecular pathways comprise the activation of NOTCH1, MYC, PRDX2, WNT, CYR61, EGFR/Pl3K, DDR1 signaling, and cytokine upregulation. Despite providing a comprehensive overview of potential pathogenic mechanisms of OSF, the involvement of molecules functioning as areca alkaloid receptors, namely, the muscarinic and nicotinic acetylcholine receptors (AChRs), was not elucidated with this approach. Accordingly, our search strategy was refined to reflect these evidence gaps. The results of the second round of reviews with the post hoc search highlighted that arecoline binds preferentially to muscarinic AChRs, which have been implicated in cancer. Consistently, AChRs activate the signaling pathways that partially overlap with those described in the context of arecoline-induced carcinogenesis. In summary, we used a theory-driven interpretive review methodology to inform, extend, and supplement the conventional systematic literature assessment workflow. On the one hand, the results of this critical interpretive synthesis highlighted the prevailing trends and enabled the consolidation of data pertaining to the molecular mechanisms involved in arecoline-induced carcinogenesis, and, on the other, brought up knowledge gaps related to the role of the local cholinergic axis in oral carcinogenesis, thus suggesting areas for further investigation.

The Combined Middle and Inferior Antrostomy for Fungal Maxillary Sinusitis Treatment

Aims: The objective of this study is to assess the effectiveness of the combined middle and inferior meatal antrostomy (MIMA) in management of patients with maxillary fungal sinusitis. Material and Methods: Design: retrospective cross sectional study. Setting and subjects: From September 2018 to March 2021, fifty-five patients with non-invasive maxillary fungal sinusitis, who underwent transnasal endoscopic combined MIMA. Methods: The study compared patients' pre- and post-operative subjective symptoms, including nasal obstruction, discharge, facial pain or pressure, halitosis, anosmia, and other non-specific symptoms. Endoscopic characteristics of recurrent fungal maxillary sinusitis and postoperative complications were also observed. Closure of the IMA site was evaluated at three and six months post-surgery and patients were categorized into three groups based on closure degree. Results: All clinical symptoms, including nasal discharge, nasal obstruction, nasal pruritus, anosmia, halitosis, sneezing, facial pain, ophthalmic and otologic symptoms, were resolved over six months after combined MIMA in majority of cases (94 - 100%). After three and six months, the postoperative endoscopic evaluation revealed recurrent fungal maxillary sinusitis in 1.8% and 5.4% of cases, respectively. Partial stenosis of the inferior antrostomy was observed in 7.2% and 16% of cases, while complete stenosis was noted in 3.6% and 7.2% of cases after three months and six months. Conclusions: The combined MIMA is effective and has better outcomes than the medial meatal antrostomy approach alone without additional operative time.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03863-6.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω[over ˜]_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From the ratio ω_{a}/ω[over ˜]_{p}^{'}, together with precisely determined external parameters, we determine a_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.

In vitro immune and redox response induced by cationic cellulose-based nanomaterials

Cellulose nanocrystals (CNCs) display remarkable strength and physicochemical properties with significant potential applications. To better understand the potential adjuvanticity of a nanomaterial, it is important to investigate the extent of the immunological response, the mechanisms by which they elicit this response, and how this response is associated with their physicochemical characteristics. In this study, we investigated the potential mechanisms of immunomodulation and redox activity of two chemically related cationic CNC derivatives (CNC-METAC-1B and CNC-METAC-2B), using human peripheral blood mononuclear cells and mouse macrophage cells (J774A.1). Our data demonstrated that the biological effects caused by these nanomaterials occurred mainly with short term exposure. We observed opposite immunomodulatory activity between the tested nanomaterials. CNC-METAC-2B, induced IL-1β secretion at 2 h while CNC-METAC-1B decreased it at 24 h of treatment. In addition, both nanomaterials caused more noticeable increases in mitochondrial reactive oxygen species (ROS) at early time. The differences in apparent sizes of the two cationic nanomaterials could explain, at least in part, the discrepancies in biological effects, despite their closely related surface charges. This work provides initial insights about the complexity of the in vitro mechanism of action of these nanomaterials as well as foundation knowledge for the development of cationic CNCs as potential immunomodulators.

A profile of students in a university-based distance dementia education program: Implications for policy and practice

OBJECTIVE

The online program began in 2012 to support aged care workers without a tertiary education or vocational qualification. This paper documents changes in the student profile since initiation of the program, and how the program may support recommendations of the Royal Commission into Aged Care Quality and Safety and engage other educators, providers and policymakers.

METHODS

Four hundred and seventy-one commencing undergraduate students completed a 16-item online survey in 2017 to document demographics and reasons for study. Categorical associations were assessed with univariate logistic regression in R v3.6.

RESULTS

Most students (71%; 336) were aged between 41 and 60 years but the program now included younger (<41 years) and older (>80 years) people. Unlike the 2012 students, about 41% had tertiary-level qualifications, and 56% were employed in professional positions, including registered nurse, general practitioner and allied health professional. Professional and practice development was the primary reason for study; significantly so for younger (<41 years) participants in aged and dementia care (χ2 (5) = 18.15, p = 0.003) and for those with previous university experience (χ2 (4) = 22.17, p = 0.001). Older (≥61 years) participants enrolled to gain greater knowledge about dementia (χ2 (4) = 17.60, p = 0.002).

CONCLUSIONS

Understanding the changed student profile guided program refinement to ensure the provision of effective, evidence-based education in dementia understanding and care. Work now focusses on increasing partnerships with aged care organisations, community and postsecondary training institutions to support a continuum of workforce development options, guided by the recommendations of the Royal Commission.

The efficacy of albumin-globulin ratio to predict prognosis in cancer patients

The goal of this systematic review was to identify all of the research within the last 10 years that investigated both the Albumin-Globulin Ratio (AGR) and outcomes of solid tumor cancer patients via quantitative prognostic variables. Multiple scientific databases were researched for journal articles that included keywords relating AGR to prognosis. Once isolated from the databases, the articles were de-duplicated and manually screened based on standardized inclusion/exclusion criteria in a blind format via Rayyan. The collective data were sorted by cancer type, corrected for population size, and used to calculate the average cut-off values for the most popular prognostic variables. In total, 18 independent types of cancer have been evaluated to see if AGR is a prognostic indicator based on multivariate analyses. The average cut-off value for AGR in overall survival was 1.356, while the average cut-off value for AGR in progression free survival was 1.292. AGR was found to be significantly associated with at least one prognostic variable in every type of cancer evaluated based on multivariate analyses. The ease of access and affordability of AGR makes it an invaluable tool applicable to nearly all patients. Overall, AGR is a proven prognostic variable that should always be considered in the evaluation of a solid tumor cancer patient's prognosis. Further research needs to be conducted studying the potential prognostic effect in more types of solid tumors.

Successful surgical management of an aggressive IgG4-related sclerosing esophageal inflammatory pseudotumor: a case report and review of literature

BACKGROUND

Inflammatory pseudotumor (IPT) of the esophagus is a very rare benign lesions which clinical presentation is not clear and difficult to make a definitive diagnosis preoperatively.

CASE PRESENTATION

In this report, we presented a case of a 24-year-old female with signs of severe malnutrition state due to dysphagia increasing gradually and losing 10 kg in weight for 2 months. Comprehensive preoperative radiologic investigations were proceeded with a circumferential severe stricture caused smooth submucosal swelling in the esophagus under 23 cm from the upper dental arch and two times of negative biopsy. Due to the aggressive clinical symptoms and gross lesion characteristics, the patient underwent laparoscopic-thoracoscopic esophagectomy and reconstruction with a gastric tube. Histopathological examination showed that the squamous epithelium of the esophagus had a small, benign nucleus, the submucosal layer and the smooth muscle layer increased fibrous, with infiltrating many lymphocytes, plasma cells, and macrophages. Immunohistochemical staining was negative for CD68, CD34, Desmin and ALK markers, and there was an increase in the number of IgG4-positive plasma cells. The final diagnosis was an aggressive IgG4-related sclerosing esophageal inflammatory pseudotumor.

CONCLUSIONS

Inflammatory pseudotumor of the esophagus is an extremely rare benign lesion but could led to aggressive clinical presentation. The gold standard of diagnosis is histopathological examination of surgically removed specimens. Radical resection is still the most efficient treatment method.

Variations in Anxiety and Related Psychiatric Comorbidity Levels Among Youths With Individual Diagnoses of Autism Spectrum Disorder or Attention Deficit Hyperactivity Disorder and Those With Both Diagnoses

Children with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) individually and those with co-occurring ADHD and ASD experience higher rates of total anxiety and psychiatric comorbidities such as gender dysphoria and locomotor skills compared to their typically developing (TD) peers. In this study, it was hypothesized that youth with comorbid ADHD and ASD would experience higher levels of overall anxiety, specifically separation, generalized, and social anxiety. A literature review of relevant studies published from 2007 to 2020 was performed, with a search involving key terms such as "Anxiety," "ADHD" and "ASD'". It was discovered that individuals with ADHD or ASD had higher levels of anxiety compared to their peers. Furthermore, children who have co-occurring ADHD and ASD had more serve levels of anxiety than children with an individual diagnosis of ADHD or ASD. Children with ASD, ADHD, and co-occurring ADHD and ASD had a higher prevalence of gender dysphoria and impaired locomotor skills, which lead to higher levels of psychiatric comorbidities seen in this population. It can be hypothesized psychiatric comorbidities could also have implications for the high anxiety levels seen in this population but further research is needed to confirm this.

Persistent level 1 hypoglycemia due to hypothyroidism and underlying Neurofibromatosis type 1

Key Clinical Message

Hypoglycemia in non-diabetic patients is rare and may be due to various etiologies. It is important to recognize hypoglycemia early and appropriately manage hypoglycemia in patients with neurofibromatosis 1 and hypothyroidism.

Abstract

Non-diabetic hypoglycemia is not common and can be seen in certain conditions like Neurofibromatosis type 1 (NF1). We report a rare case of 66-year-old man with hypothyroidism and NF1 who developed a persistent level 1 hypoglycemia.

Usage of Tranexamic Acid for Treatment of Subdural Hematomas

The collection of blood in the subdural layer within the cranium is classified as a subdural hematoma. Prevalence of subdural hematomas is most common among older populations with the current standard of treatment being invasive surgical evacuation for patients presenting with acute subdural hematomas with a midline shift greater than 5 mm on computed tomography (CT).Tranexamic acid (TXA) has been identified as an alternative, non-invasive option to treat patients presenting with subdural hematoma who are not suitable for surgical intervention. The presenting case involves a 90-year-old female who arrived with a code stroke with the chief complaint of right lower extremity weakness. A stroke series CT panel revealed a left frontal multiloculated subdural hematoma, measuring 130 mL with mass effect and a midline shift of 7 mm. The patient was recommended a craniotomy for hematoma evacuation or access to hospice for comfort care. A second opinion resulted in the administration of TXA. After the full completion of a TXA course, the patient achieved baseline mobility. The final measurements revealed a final hematoma volume of 10 mL and a midline shift of less than 2 mm. Current literature, as well as the case described, has begun demonstrating the efficacy of the usage of TXA in the reabsorption of subdural hematomas and should encourage further exploration into society guidelines for the usage of TXA as a non-invasive alternative to treat subdural hematomas.

Catchment sourcing urban pesticide pollution using constructed wetlands in Melbourne, Australia

A survey of 111 urban constructed stormwater wetlands (median watershed area = 86.8 ha) was conducted to identify the major pesticides present and to determine their major catchment sources (residential, industrial, commercial, sporting ovals) and associations with catchment imperviousness. Melbourne, Australia, has separate stormwater and sewerage systems and these wetlands are designed to treat urban stormwater. To maximise the pesticides that could be detected, three types of passive samplers (POCIS, Chemcatcher® SDB-XC and Chemcatcher® C18) were deployed, along with collection of fine sediments. A total of 231 pesticides were screened using these methods. Pesticides that were detected in >5 % of wetlands were checked to determine their registered use in urban areas using an Australian government database (PubCris). Twenty-five pesticides were detected in >5 % of wetlands: 4 pesticides were associated with non-urban land uses (agriculture and forests), another 4 pesticides had no known registered use in urban areas and 17 were associated with urban areas. The pesticides associated with urban areas were the herbicides simazine, diuron, metolachlor, bromacil, propyzamide and paclobutrazol, the fungicides tebuconazole, propiconazole, metalaxyl, trifloxystrobin, iprodione and carbendazim and the insecticides fipronil, bifenthrin, chlorantraniliprole, thiamethoxam and permethrin. Atrazine was also detected in 59 % of wetlands but has not been registered for urban uses in Australia since 2010. It's presence in Melbourne may be due to legacy issues or aerial transportation from rural areas where it's still widely used in crop cultivation. Generally, the major urban catchment source of pesticides is from residential areas (particularly fipronil and simazine), most likely in wood preservatives, paints and from weed or insect control. Many of these widely used pesticides were correlated with increased catchment imperviousness. Some pesticides (bromacil and imidacloprid) were correlated with commercial premises and chlorantraniliprole was correlated with the presence of sporting ovals in the catchment. No pesticides were specifically correlated with industrial areas. The use of passive samplers and fine sediments, in conjunction with detailed land use mapping of stormwater wetland catchments is very effective and efficient in monitoring and sourcing pesticide contamination in urban environments.

A261 SEVERE ACUTE LIVER INJURY SECONDARY TO WILSON’S DISEASE: A CASE REPORT AND REVIEW OF THE LITERATURE

Background

Wilson’s disease is autosomal recessive and rare (prevalence 1/30000-1/50000) caused by mutations in the ATP7B gene involved in copper excretion. Copper deposition drives hepatic injury, along with neuropsychiatric-ophthalmologic, and hematologic symptoms. Leipzig criteria greater than 4 establishes the diagnosis.

Purpose

We report a case of severe liver injury secondary to probable Wilson’s disease.

Method

Literature review of diagnosis, management including emerging therapies was performed using PubMed.

Result(s)

A 29-year-old otherwise healthy male with no family history of liver disease presented with abdominal pain, jaundice, and severe acute liver injury (ALT 1534 U/L ALP 114 U/L bilirubin 113 umol/L) initially misdiagnosed as hepatitis A in community urgent care. He had worsening liver injury (ALT 1809 U/L bilirubin 411 umol/L), with normal INR and no encephalopathy over an additional 3 weeks and was admitted to our tertiary care centre for further work up. History did not reveal viral prodromes, herbals or natural remedies. CBD oil was the only potential exposure, though longstanding use of the same brand argued against this as a cause. Chronic liver disease workup was negative (viral hepatitides, SARS-CoV-2, alpha-1-antitrypsin, acetaminophen level, iron profile, and comprehensive Mitogen autoantibody panel). Patent vasculature on Doppler US. Liver biopsy showed diffuse lobular inflammation, hepatocyte necrosis, 30% parenchymal involvement, primarily lymphocytes with some eosinophils and plasma cells, and no viral inclusions suggesting acute hepatitis with drugs or viral hepatitis as etiologies. The 24-hour urine copper was elevated at 2.19 umol/d (<0.80). Biopsy copper dry weight 60mcg/g (N<50; >250 diagnostic). Normal ceruloplasmin 0.30g/L and serum copper 25.8 umol/L. MRI brain not suggestive of Wilson’s disease, no Kayser-Fleischer rings on Ophthalmology assessment, and no hemolysis. Given a Leipzig score of 3 suggesting possible Wilson’s disease he was started on penicillamine 1500mg daily. Five weeks later he had serologic (ALT 1061 U/L bilirubin 128 umol/L) improvement, yet elevated elastography at 22kPa IQR 5% likely due to inflammation. Given coverage issues, he was switched to compassionate trientine 500mg BID with further improvement (ALT 347 U/L bilirubin 26 umol/L). Sequencing for ATP7B gene mutations are pending (Blueprint Genetics).

Conclusion(s)

Wilson’s disease should be considered in those with hepatic or neuropsychiatric symptoms, transaminases in the 1000s or acute liver failure. Treatment is lifelong with typically good prognosis and is fatal if untreated. Treatment options include chelators D-penicillamine (first line, with side effects including proteinuria and worsened neurological symptoms) and trientine (fewer side effects). Zinc prevents copper absorption and can be used in asymptomatic patients. Transplant in acute liver failure and end-stage liver disease is guided by the King’s score. Several novel therapies including gene therapy are in development.

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Reconstruction of Large Anterior Skull Base Defects After Resection of Sinonasal Tumors With Intracranial Extension by Using Pedicled Double Flap Techniques

INTRODUCTION

The use of surgical resection for large anterior skull base (ASB) tumors and sinonasal malignancies with intracranial extension will result in a large skull base defect. Reconstruction of large ASB defects using traditional techniques is high risk and may lead to postoperative cerebral spinal fluid (CSF) leakage, meningitis, and an increase in mortality rate. The use of a pedicled double flap technique to reconstruct the ASB defect may decrease complications. This study presents the clinical outcomes of patients who underwent double flap reconstruction techniques after resection of their sinonasal malignancies with significant intracranial extension at Cho Ray hospital in Vietnam.

METHODS

The case series study was conducted at Cho Ray hospital from September 2010 to September 2020. All patients with large sinonasal malignancies that invaded intracranially underwent transnasal endoscopic surgery and subfrontal craniotomy. Reconstruction of large skull base defects (>2 cm) were followed up by using the pedicled double flaps technique. This study was performed in line with the principles of the Declaration of Helsinki. Approval of the study was granted by the Independent Ethics Committee of Cho Ray Hospital (Date: March 3, 2014/No: 11/BVCRHĐĐĐ).

RESULTS

During September 2010 to September 2020, there were 75 patients who underwent a modified multilayer, double flap reconstruction technique after the resection of their ASB tumor. Skull base defects were commonly seen along the horizontal plate of the ethmoid bone and the ethmoid roof (98.6%). Large skull base defects (>2 cm) accounted for 81.3% of cases. Overall, the risk of postoperative CSF leakage and meningitis after double flap repair was considerably low. Of all participants, only 1 experienced postoperative CSF leakage and 1 experienced postoperative meningitis. Despite the complications, these patients improved significantly and remained stable.

CONCLUSION

The use of double vascularized pedicled flaps may decrease the incidence of postoperative CSF leakage and meningitis. This technique is an effective method for the reconstruction of ASB tumors with large defects.

Application of gabapentinoids and novel compounds for the treatment of benzodiazepine dependence: the glutamatergic model

BACKGROUND

Current approaches for managing benzodiazepine (BZD) withdrawal symptoms are daunting for clinicians and patients, warranting novel treatment and management strategies. This review discusses the pharmacodynamic properties of BZDs, gabapentinoids (GBPs), endozepines, and novel GABAergic compounds associated with potential clinical benefits for BZD-dependent patients. The objective of this study was to review the complex neuromolecular changes occurring within the GABAergic and glutamatergic systems during the BZD tolerance and withdrawal periods while also examining the mechanism by which GBPs and alternative pharmacological therapies may attenuate withdrawal symptoms.

METHODS AND RESULTS

An elaborative literature review was conducted using multiple platforms, including the National Center for Biotechnology (NCBI), AccessMedicine, ScienceDirect, pharmacology textbooks, clinical trial data, case reports, and PubChem. Our literature analysis revealed that many distinctive neuroadaptive mechanisms are involved in the GABAergic and glutamatergic systems during BZD tolerance and withdrawal. Based on this data, we hypothesize that GBPs may attenuate the overactive glutamatergic system during the withdrawal phase by an indirect presynaptic glutamatergic mechanism dependent on the α₂δ₁ subunit expression.

CONCLUSIONS

GBPs may benefit individuals undergoing BZD withdrawal, given that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor current significantly increases during abrupt BZD withdrawal in animal studies. This may be a conceivable explanation for the effectiveness of GBPs in treating both alcohol withdrawal symptoms and BZD withdrawal symptoms in some recent studies. Finally, natural and synthetic GABAergic compounds with unique pharmacodynamic properties were found to exert potential clinical benefits as BZD substitutes in animal studies, though human studies are lacking.

Misinformation and Impact on Interprofessional Healthcare Students' Knowledge, Attitudes, Perceptions, and Concerns of COVID-19

BACKGROUND

The COVID-19 pandemic has highlighted the importance of information sources (e.g., Internet, social media) and their role in spreading misinformation.

PURPOSE

To describe the information sources and frequency of use by health professional students and to compare users of dependable and nontrustworthy news sources on stressors, stress relievers, safety, and preventative activities, worries, and attitudes toward COVID-19.

METHODS

123 students from nursing (38%), medicine (33%), and health professions (28%) completed online surveys on disaster preparedness training, knowledge of the COVID-19 virus, and safety and prevention practices. Students were mostly female (81%), white (59%), and aged 21-30 yrs (72%).

RESULTS

Students who relied on credible news sources scored higher on knowledge of the COVID-19 condition and reported less stress than their counterparts.

CONCLUSION

The findings emphasize the importance of students avoiding untrustworthy news sources. Informed students are less stressed and can help initiate necessary safety measures in the areas they serve.

Mechanisms of Mg carbonates precipitation and implications for CO2 capture and utilization/storage

The mechanisms involved in the natural formations of dolomite (CaMg(CO3)2) and magnesite (MgCO3) have endured as challenging research questions over centuries, being yet a matter under investigation in multiple fields....

Discovery of Potent and Selective Dual Leucine Zipper Kinase/Leucine Zipper-Bearing Kinase Inhibitors with Neuroprotective Properties in In Vitro and In Vivo Models of Amyotrophic Lateral Sclerosis

Dual leucine zipper kinase (DLK) and leucine zipper-bearing kinase (LZK) are regulators of neuronal degeneration and axon growth. Therefore, there is a considerable interest in developing DLK/LZK inhibitors for neurodegenerative diseases. Herein, we use ligand- and structure-based drug design approaches for identifying novel amino-pyrazine inhibitors of DLK/LZK. DN-1289 (14), a potent and selective dual DLK/LZK inhibitor, demonstrated excellent in vivo plasma half-life across species and is anticipated to freely penetrate the central nervous system with no brain impairment based on in vivo rodent pharmacokinetic studies and human in vitro transporter data. Proximal target engagement and disease relevant pathway biomarkers were also favorably regulated in an in vivo model of amyotrophic lateral sclerosis.

Understanding Audiobook Apps’ Consumption Values and Their Implications for Promoting Audiobooks in Vietnam

Audiobooks have recently become more prevalent in the publishing industry. Vietnam is a potential market for audiobook companies, and audiobook apps are soaring in popularity in this country. This study examines how consumers perceive audiobook apps’ consumption values, including functional value, social value, emotional value, epistemic value, and conditional value. Data were obtained from 1041 Vietnamese consumers using an online survey method. Results show that conditional value had the highest mean score, followed by epistemic value and emotional value. Notably, consumers hold negative perceptions of audiobook apps’ functional value, especially regarding their reliability and consistency. The findings also suggest that consumers will use audiobook apps more if there are more discounts, promotional benefits, and books available in the apps. This study is the first to explain how consumers perceive the different consumption values of audiobook apps, which have important implications for audiobook companies, publishers and app developers to promote audiobooks.

Consumer Access, Appraisal, and Application of Services and Information for Dementia (CAAASI-Dem): a validation study

Objectives: The Consumer Access, Appraisal, and Application of Services and Information for Dementia (CAAASI-Dem) was developed to examine individuals' self-assessed confidence in their ability to access, appraise and use dementia services and information. The CAAASI-Dem is the only tool to date to measure this crucial component of dementia literacy. This study was designed to validate its structural validity.Method: Data was collected from 3277 participants enrolled in an on-line dementia course. The five-factor structure of the CAAASI-Dem, which was derived from a previous exploratory factor analysis, was evaluated using confirmatory factor analysis. Internal reliability, convergent and divergent validity, and known-groups validity were assessed. Results: The five-factor model demonstrated good fit with the observed data with the removal of 2 items and movement of 1 item across the factors. The resultant 24-item five-factor CAAASI-Dem showed very good sub-scale internal reliability and satisfactory convergent and divergent validity. There was good discrimination between groups of participants with different levels of care experience.Conclusion: The results provided evidence for the 24-item CAAASI-Dem as a valid and reliable five-dimensional scale. Limitations of the study are discussed, and recommendations are made for future research and practice.

Hallucinating symmetric protein assemblies

Deep learning generative approaches provide an opportunity to broadly explore protein structure space beyond the sequences and structures of natural proteins. Here, we use deep network hallucination to generate a wide range of symmetric protein homo-oligomers given only a specification of the number of protomers and the protomer length. Crystal structures of seven designs are very similar to the computational models (median root mean square deviation: 0.6 angstroms), as are three cryo-electron microscopy structures of giant 10-nanometer rings with up to 1550 residues and C33 symmetry; all differ considerably from previously solved structures. Our results highlight the rich diversity of new protein structures that can be generated using deep learning and pave the way for the design of increasingly complex components for nanomachines and biomaterials.

Robust deep learning-based protein sequence design using ProteinMPNN

Although deep learning has revolutionized protein structure prediction, almost all experimentally characterized de novo protein designs have been generated using physically based approaches such as Rosetta. Here, we describe a deep learning-based protein sequence design method, ProteinMPNN, that has outstanding performance in both in silico and experimental tests. On native protein backbones, ProteinMPNN has a sequence recovery of 52.4% compared with 32.9% for Rosetta. The amino acid sequence at different positions can be coupled between single or multiple chains, enabling application to a wide range of current protein design challenges. We demonstrate the broad utility and high accuracy of ProteinMPNN using x-ray crystallography, cryo-electron microscopy, and functional studies by rescuing previously failed designs, which were made using Rosetta or AlphaFold, of protein monomers, cyclic homo-oligomers, tetrahedral nanoparticles, and target-binding proteins.

Secondary Syphilis Presenting as Erythema Multiforme in the Setting of AIDS and Psoriasis

Syphilis is a highly infectious sexually transmitted infection (STI) with a multitude of presentations. The disease is known as "the great imitator" as it often presents as other chronic dermatoses, leading to a difficult and delayed diagnosis. Here, we describe the case of a 17-year-old Vietnamese male from Dong Nai Province who was initially diagnosed with psoriasis. However, upon further investigation, he was found to have concurrent secondary syphilis and psoriasis complicated by an undiagnosed human immunodeficiency virus (HIV) infection which presented clinically as generalized erythema multiforme (EM). The patient demonstrated significant improvement after being treated for syphilis and psoriasis, and he was subsequently referred to an infectious disease specialist for treatment of the underlying HIV infection.

Ensemble learning using traditional machine learning and deep neural network for diagnosis of Alzheimer's disease

In recent years, Alzheimer's disease (AD) diagnosis using neuroimaging and deep learning has drawn great research attention. However, due to the scarcity of training neuroimaging data, many deep learning models have suffered from severe overfitting. In this study, we propose an ensemble learning framework that combines deep learning and machine learning. The deep learning model was based on a 3D-ResNet to exploit 3D structural features of neuroimaging data. Meanwhile, Extreme Gradient Boosting (XGBoost) machine learning was applied on a voxel-wise basis to draw the most significant voxel groups out of the image. The 3D-ResNet and XGBoost predictions were combined with patient demographics and cognitive test scores (Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR)) to give a final diagnosis prediction. Our proposed method was trained and validated on brain MRI brain images of the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. During the training phase, multiple data augmentation methods were employed to tackle overfitting. Our test set contained only baseline scans, i.e., the first visit scans since we aimed to investigate the ability of our approach in detecting AD during the first visit of AD patients. Our 5-fold cross-validation implementation achieved an average AUC of 100% during training and 96% during testing. Using the same computer, our method was much faster in scoring a prediction, approximately 10 min, than feature extraction-based machine learning methods, which often take many hours to score a prediction. To make the prediction explainable, we visualized the brain MRI image regions that primarily affected the 3D-ResNet model's prediction via heatmap. Lastly, we observed that proper generation of test sets was critical to avoiding the data leakage issue and ensuring the validity of results.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Novel App knock-in mouse model shows key features of amyloid pathology and reveals profound metabolic dysregulation of microglia

BACKGROUND

Genetic mutations underlying familial Alzheimer's disease (AD) were identified decades ago, but the field is still in search of transformative therapies for patients. While mouse models based on overexpression of mutated transgenes have yielded key insights in mechanisms of disease, those models are subject to artifacts, including random genetic integration of the transgene, ectopic expression and non-physiological protein levels. The genetic engineering of novel mouse models using knock-in approaches addresses some of those limitations. With mounting evidence of the role played by microglia in AD, high-dimensional approaches to phenotype microglia in those models are critical to refine our understanding of the immune response in the brain.

METHODS

We engineered a novel App knock-in mouse model (AppSAA) using homologous recombination to introduce three disease-causing coding mutations (Swedish, Arctic and Austrian) to the mouse App gene. Amyloid-β pathology, neurodegeneration, glial responses, brain metabolism and behavioral phenotypes were characterized in heterozygous and homozygous AppSAA mice at different ages in brain and/ or biofluids. Wild type littermate mice were used as experimental controls. We used in situ imaging technologies to define the whole-brain distribution of amyloid plaques and compare it to other AD mouse models and human brain pathology. To further explore the microglial response to AD relevant pathology, we isolated microglia with fibrillar Aβ content from the brain and performed transcriptomics and metabolomics analyses and in vivo brain imaging to measure energy metabolism and microglial response. Finally, we also characterized the mice in various behavioral assays.

RESULTS

Leveraging multi-omics approaches, we discovered profound alteration of diverse lipids and metabolites as well as an exacerbated disease-associated transcriptomic response in microglia with high intracellular Aβ content. The AppSAA knock-in mouse model recapitulates key pathological features of AD such as a progressive accumulation of parenchymal amyloid plaques and vascular amyloid deposits, altered astroglial and microglial responses and elevation of CSF markers of neurodegeneration. Those observations were associated with increased TSPO and FDG-PET brain signals and a hyperactivity phenotype as the animals aged.

DISCUSSION

Our findings demonstrate that fibrillar Aβ in microglia is associated with lipid dyshomeostasis consistent with lysosomal dysfunction and foam cell phenotypes as well as profound immuno-metabolic perturbations, opening new avenues to further investigate metabolic pathways at play in microglia responding to AD-relevant pathogenesis. The in-depth characterization of pathological hallmarks of AD in this novel and open-access mouse model should serve as a resource for the scientific community to investigate disease-relevant biology.

Preclinical and clinical evaluation of the LRRK2 inhibitor DNL201 for Parkinson's disease

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic risk factors for Parkinson's disease (PD). Increased LRRK2 kinase activity is thought to impair lysosomal function and may contribute to the pathogenesis of PD. Thus, inhibition of LRRK2 is a potential disease-modifying therapeutic strategy for PD. DNL201 is an investigational, first-in-class, CNS-penetrant, selective, ATP-competitive, small-molecule LRRK2 kinase inhibitor. In preclinical models, DNL201 inhibited LRRK2 kinase activity as evidenced by reduced phosphorylation of both LRRK2 at serine-935 (pS935) and Rab10 at threonine-73 (pT73), a direct substrate of LRRK2. Inhibition of LRRK2 by DNL201 demonstrated improved lysosomal function in cellular models of disease, including primary mouse astrocytes and fibroblasts from patients with Gaucher disease. Chronic administration of DNL201 to cynomolgus macaques at pharmacologically relevant doses was not associated with adverse findings. In phase 1 and phase 1b clinical trials in 122 healthy volunteers and in 28 patients with PD, respectively, DNL201 at single and multiple doses inhibited LRRK2 and was well tolerated at doses demonstrating LRRK2 pathway engagement and alteration of downstream lysosomal biomarkers. Robust cerebrospinal fluid penetration of DNL201 was observed in both healthy volunteers and patients with PD. These data support the hypothesis that LRRK2 inhibition has the potential to correct lysosomal dysfunction in patients with PD at doses that are generally safe and well tolerated, warranting further clinical development of LRRK2 inhibitors as a therapeutic modality for PD.

MODL-17. The Childhood Brain Cancer Cell Line Atlas: A Resource for Biomarker Identification and Therapeutic Development

Cell lines represent the most versatile and widely used models of cancer and, as such, are critical for identifying and advancing new therapies. Strikingly, there is a significant gap in both the number of childhood brain cancer cell lines and their characterisation compared to their adult counterparts. To address this inequity, we established a childhood brain cancer cell line atlas (publicly available at vicpcc.org.au/dashboard) encompassing over 180 childhood CNS-derived cell lines, representing 20 tumour types and 11 molecular subtypes. Cell lines are characterized by whole genome, RNA-sequencing, phospho- and total proteomics, DNA methylation and ATAC-seq analyses. Multi-omic factor analysis revealed distinct lineage-specified classification of our cell line cohort. In parallel, high throughput drug and CRISPR/Cas9 screens were conducted to map the functional dependencies in over 70 childhood CNS cell lines, including 47 paediatric high grade glioma models. These screens identified both lineage and molecular-subtype specific genetic and drug dependencies, underscoring the utility of this wide-scale approach. Machine based learning approaches to predict genotype-phenotype correlations uncovered distinct paediatric-specific biomarkers of growth dependency, highlighting the unique genetic wiring underlying paediatric CNS tumours. Finally, by integrating functional, molecular and drug profiles of paediatric CNS cell lines, we construct a system to prioritize investigation of novel therapeutic target-biomarkers pairs in specific CNS tumour types.