Lysinoalanine cross-linking is a conserved post-translational modification in the spirochete flagellar hook

Spirochetes cause Lyme disease, leptospirosis, syphilis, and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by the action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) and Lyme disease pathogen Borreliella burgdorferi (Bb) form covalent lysinoalanine (Lal) cross-links between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. In Td, Lal is unnecessary for hook assembly but is required for motility, presumably due to the stabilizing effect of the cross-link. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal cross-linked peptides in recombinant and in vivo-derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp. As was observed with Td, a mutant strain of Bb unable to form the cross-link has greatly impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans FlgE also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveal that the Lal cross-link is a conserved and necessary posttranslational modification across the spirochete phylum and may thus represent an effective target for the development of spirochete-specific antimicrobials.

Conserved and divergent gene regulatory programs of the mammalian neocortex

Divergence of cis-regulatory elements drives species-specific traits1, but how this manifests in the evolution of the neocortex at the molecular and cellular level remains unclear. Here we investigated the gene regulatory programs in the primary motor cortex of human, macaque, marmoset and mouse using single-cell multiomics assays, generating gene expression, chromatin accessibility, DNA methylome and chromosomal conformation profiles from a total of over 200,000 cells. From these data, we show evidence that divergence of transcription factor expression corresponds to species-specific epigenome landscapes. We find that conserved and divergent gene regulatory features are reflected in the evolution of the three-dimensional genome. Transposable elements contribute to nearly 80% of the human-specific candidate cis-regulatory elements in cortical cells. Through machine learning, we develop sequence-based predictors of candidate cis-regulatory elements in different species and demonstrate that the genomic regulatory syntax is highly preserved from rodents to primates. Finally, we show that epigenetic conservation combined with sequence similarity helps to uncover functional cis-regulatory elements and enhances our ability to interpret genetic variants contributing to neurological disease and traits.

Effectiveness of icosapent ethyl on first and total cardiovascular events in patients with metabolic syndrome, but without diabetes: REDUCE-IT MetSyn

Aims

Metabolic syndrome (MetSyn) is associated with high risk of cardiovascular (CV) events, irrespective of statin therapy. In the overall REDUCE-IT study of statin-treated patients, icosapent ethyl (IPE) reduced the risk of the primary composite endpoint (CV death, non-fatal myocardial infarction, non-fatal stroke, coronary revascularization, or unstable angina requiring hospitalization) and the key secondary composite endpoint (CV death, non-fatal myocardial infarction, or non-fatal stroke).

Methods and results

REDUCE-IT was an international, double-blind trial that randomized 8179 high CV risk statin-treated patients with controlled LDL cholesterol and elevated triglycerides, to IPE 4 g/day or placebo. The current study evaluated the pre-specified patient subgroup with a history of MetSyn, but without diabetes at baseline. Among patients with MetSyn but without diabetes at baseline (n = 2866), the majority (99.8%) of this subgroup was secondary prevention patients. Icosapent ethyl use was associated with a 29% relative risk reduction for the first occurrence of the primary composite endpoint [hazard ratio: 0.71; 95% confidence interval (CI): 0.59-0.84; P < 0.0001, absolute risk reduction (ARR) = 5.9%; number needed to treat = 17] and a 41% reduction in total (first plus subsequent) events [rate ratio: 0.59; (95% CI: 0.48-0.72); P < 0.0001] compared with placebo. The risk for the key secondary composite endpoint was reduced by 20% (P = 0.05) and a 27% reduction in fatal/non-fatal MI (P = 0.03), 47% reduction in urgent/emergent revascularization (P < 0.0001), and 58% reduction in hospitalization for unstable angina (P < 0.0001). Non-statistically significant reductions were observed in cardiac arrest (44%) and sudden cardiac death (34%).

Conclusion

In statin-treated patients with a history of MetSyn, IPE significantly reduced the risk of first and total CV events in REDUCE-IT. The large relative and ARRs observed supports IPE as a potential therapeutic consideration for patients with MetSyn at high CV risk. Registration REDUCE-IT ClinicalTrials.gov number: NCT01492361.

A comparative atlas of single-cell chromatin accessibility in the human brain

Recent advances in single-cell transcriptomics have illuminated the diverse neuronal and glial cell types within the human brain. However, the regulatory programs governing cell identity and function remain unclear. Using a single-nucleus assay for transposase-accessible chromatin using sequencing (snATAC-seq), we explored open chromatin landscapes across 1.1 million cells in 42 brain regions from three adults. Integrating this data unveiled 107 distinct cell types and their specific utilization of 544,735 candidate cis-regulatory DNA elements (cCREs) in the human genome. Nearly a third of the cCREs demonstrated conservation and chromatin accessibility in the mouse brain cells. We reveal strong links between specific brain cell types and neuropsychiatric disorders including schizophrenia, bipolar disorder, Alzheimer's disease (AD), and major depression, and have developed deep learning models to predict the regulatory roles of noncoding risk variants in these disorders.

Risk Factors Associated with Development of Peritumoral Edema Following Stereotactic Radiosurgery and Radiotherapy for Intracranial Meningioma

PURPOSE/OBJECTIVE(S)

Peritumoral edema (PTE) is a potential adverse effect following radiotherapy for intracranial meningioma. The purpose of this study is to identify which baseline factors may increase risk for PTE.

MATERIALS/METHODS

A retrospective chart review was conducted of 431 patients who underwent primary radiotherapy to 480 radiographically-defined intracranial meningiomas between January 2008 and December 2021 within an integrated health care system. Patients with prior surgical management were excluded. Patients were treated with frameless LINAC-based image-guided single fraction stereotactic radiosurgery (SRS) (32.9%), 5 fraction SRS (FSRS) (30.8%), or fractionated stereotactic radiotherapy (FSRT) (36.3%). Pre- and post-radiotherapy MRI studies were reviewed to evaluate for PTE following treatment. An event was defined as new or worsening PTE compared to pre-radiotherapy imaging or development of new symptoms post-radiotherapy. Univariate and stepwise logistics regression analyses were performed to compare the risk of PTE between groups.

RESULTS

Median follow-up was 85.8 months (IQR: 49.4-125.4). Median patient age was 66 years (IQR: 56-73). Patients treated with SRS (median age: 61 years) were younger than those treated with FSRS/FSRT (median age: 68 years) (p<0.001). Lesions treated with SRS (median volume: 1.33cc) were smaller than those treated with FSRS/FSRT (median volume: 6.36cc) (p<0.001). For all-comers, 68 (14.2%) lesions developed any PTE, and 27 (5.6%) developed symptomatic PTE (SPTE). Of these, 4 patients developed symptoms post-treatment without radiographic evidence of new or worsening PTE. Incidence of PTE/SPTE by site was as follows: base of skull (BOS): 10.3%/6.1%, convexity: 22.7%/7.6%, falcine: 17.6%/4.1%, parasagittal: 27.8%/8.3%, posterior fossa/tentorium 7.0%/0.0%. Incidence of PTE/SPTE by technique was as follows: SRS: 6.3%/3.8%, FSRS: 20.9%/7.4%, FSRT: 15.5%/5.7%. On univariate analysis, age >65 (OR = 2.17 (95% CI: 1.26-3.77) p = 0.006), tumor volume (OR = 1.05 (1.02-1.08), p = 0.003), pre-treatment PTE (OR = 6.82 (95% CI: 3.59-12.94) p<0.001), and convexity/falcine/parasagittal (CFPS) location (OR = 2.52 (95% CI: 1.49-4.23) p<0.001) were associated with increased incidence of PTE. On multivariate analysis, age >65 (OR = 1.91 (95% CI: 1.05-3.45) p<0.03), tumor volume (OR = 1.04 (95% CI: 1.00-1.08) p = 0.03), pre-treatment PTE (OR = 4.64 (95% CI: 2.33-9.24) p<0.001), and CFPS location (OR = 2.53 (95% CI: 1.41-4.52) p = 0.002) were associated with increased incidence of PTE. Two patients with PTE underwent resection for local failure which revealed atypical meningioma.

CONCLUSION

Age >65, larger tumor volume, presence of pre-treatment PTE, and CFPS location were associated with increased incidence of PTE following radiotherapy. Patients with these risk factors should be counseled regarding post-treatment effects. Infrequently, PTE following treatment may be an indicator of higher-grade meningioma.

Impact of Concurrent Targeted Therapy and Immunotherapy on the Incidence of Radiation Necrosis Following Stereotactic Radiosurgery for Brain Metastases

PURPOSE/OBJECTIVE(S)

The management of metastatic disease has evolved with the advent of immunotherapy (IT) and targeted therapies (TT). Yet, there is limited understanding of the toxicity associated with combining these agents with stereotactic radiosurgery (SRS). We retrospectively evaluated the impact of concurrent systemic therapy (ST) on the risk of radiation necrosis (RN) following LINAC-based SRS for brain metastases (BM).

MATERIALS/METHODS

A retrospective study was conducted within an integrated health care system from March 2017 to December 2021 of 313 patients who underwent SRS or fractionated SRS in 3 or 5 treatments to a total of 1,644 intact BM. Post-operative cavity SRS and re-irradiated lesions were excluded. RN was diagnosed using perfusion MRI, contrast clearance MRI, or serial standard MRI and graded using CTCAE (v.5). Concurrent ST was defined as administration within 1 month preceding or following SRS. Overall survival (OS) and risk of RN were estimated by the Kaplan-Meier method. Logistics regression analyses were performed to compare risk of RN in patients who received concurrent systemic therapy to those who did not, adjusted for PTV volume and receipt of whole brain radiotherapy (WBRT).

RESULTS

Median follow-up was 12.2 months. Median age was 64 years (range: 24-92). Primary sites per patient included lung (48.9%), breast (18.2%), melanoma (11.5%), kidney (6.1%), and other (15.3%). Median total lesions treated was 3 (range: 1-44); 65.9% of patients underwent 1 course of SRS, 23.4% underwent 2 courses, 6.2% underwent 3 courses, 4.5% underwent >4 courses. Seventy-six (24.2%) patients received WBRT. Overall, 70.6% of lesions received concurrent ST including chemotherapy (CT) (32.5%), IT (26.8%), and TT (27.6%); 16.4% received a combination of ST. Median OS was 12.9 months (95% CI: 10.4-15.5). RN was observed in 50 (3.0%) lesions in 42 (13.4%) patients. The 1-year risk of RN was 4.0% per lesion and 15.4% per patient. Symptomatic RN (SRN) was observed in 31 (1.9%) lesions in 24 (7.7%) patients. The 1-year risk of SRN was 2.7% per lesion and 10.1% per patient. When compared to lesions treated without concurrent systemic therapy, there was no increased risk of RN observed in lesions treated with concurrent CT (adjusted OR = 0.86 (95% CI: 0.43-1.73) p = 0.68), concurrent IT (adjusted OR = 0.84 (95% CI: 0.41-1.71) p = 0.84), or concurrent TT (adjusted OR = 0.57 (95% CI: 0.25-1.30) p = 0.18). Treatments of SRN included dexamethasone (96.8%), bevacizumab (22.6%), and laser interstitial thermal therapy (6.5%).

CONCLUSION

Concurrent IT and TT appears well-tolerated in patients who undergo SRS for treatment of BM. No increased risk of RN was observed in lesions treated with concurrent IT or TT compared to lesions treated in the absence of concurrent ST. Further prospective and agent-specific evaluation is necessary to confirm these findings.

A Systematic Approach to the Design and Implementation of Clinical Informatics Fellowship Programs

Clinical Informatics (CI), a medical subspecialty since 2011, has grown from the initial four fellowship programs accredited by the Accreditation Council for Graduate Medical Education (ACGME) in 2014 to more than 50 and counting in the present day. In parallel, the literature guiding Clinical Informatics Fellowship training and the curriculum evolved from the original core content published in 2009 to the more recent CI Subspecialty Delineation of Practice and the updated ACGME Milestones 2.0 for CI. In this paper, we outline this evolution and its impact on CIF Curricula. We then propose a framework, specific processes, and tools to standardize the design and optimize the implementation of CIF programs.

Using a function-first 'scout fragment'-based approach to develop allosteric covalent inhibitors of conformationally dynamic helicase mechanoenzymes

Helicases, classified into six superfamilies, are mechanoenzymes that utilize energy derived from ATP hydrolysis to remodel DNA and RNA substrates. These enzymes have key roles in diverse cellular processes, such as genome replication and maintenance, ribosome assembly and translation. Helicases with essential functions only in certain cancer cells have been identified and helicases expressed by certain viruses are required for their pathogenicity. As a result, helicases are important targets for chemical probes and therapeutics. However, it has been very challenging to develop selective chemical inhibitors for helicases, enzymes with highly dynamic conformations. We envisioned that electrophilic 'scout fragments', which have been used for chemical proteomic based profiling, could be leveraged to develop covalent inhibitors of helicases. We adopted a function-first approach, combining enzymatic assays with enantiomeric probe pairs and mass spectrometry, to develop a covalent inhibitor that selectively targets an allosteric site in SARS-CoV-2 nsp13, a superfamily-1 helicase. Further, we demonstrate that scout fragments inhibit the activity of two human superfamily-2 helicases, BLM and WRN, involved in genome maintenance. Together, our findings suggest a covalent inhibitor discovery approach to target helicases and potentially other conformationally dynamic mechanoenzymes.

Therapy With Allogeneic Severe Acute Respiratory Syndrome Coronavirus-2-Specific T Cells for Persistent Coronavirus Disease 2019 in Immunocompromised Patients

We administered severe acute respiratory syndrome coronavirus-2 viral-specific T cells (VSTs) under emergency investigational new drug applications to 6 immunocompromised patients with persistent coronavirus disease 2019 (COVID-19) and characterized clinical and virologic responses. Three patients had partial responses after failing other therapies but then died. Two patients completely recovered, but the role of VSTs in recovery was unclear due to concomitant use of other antivirals. One patient had not responded to 2 courses of remdesivir and experienced sustained recovery after VST administration. The use of VSTs in immunocompromised patients with persistent COVID-19 requires further study.

Fibrates, Hypertriglyceridemia, and CVD Risk: Where Do We Stand After the PROMINENT Trial for Triglyceride Lowering?

PURPOSE OF REVIEW

To evaluate recent clinical trials focusing on patients with hypertriglyceridemia.

RECENT FINDINGS

Randomized clinical trials have recently been undertaken in hypertriglyceridemic patients to determine whether effective reductions in triglycerides would improve cardiovascular disease (CVD) outcomes. However, the fibric acid derivative, pemafibrate, failed to reduce cardiovascular events despite significant reductions (~ 25-35%) in triglyceride levels and despite background statin therapy. In contrast, icosapent ethyl, a highly purified omega-3 fatty acid was previously shown to reduce CVD events in hypertriglyceridemic patients, despite more modest reductions (~ 20%) in triglyceride levels in statin treated patients. The divergent results obtained in patients with hypertriglyceridemia (HTG), a group at particularly high risk of CVD, especially when coupled with other risk factors, indicates that triglyceride lowering in of itself is insufficient to offset CVD risk. Rather, the effectiveness of therapy in this high-risk cohort may be the result of the suppression of the inherent atherogenic properties associated with HTG.

Synthetic Colonic Mucus Enables the Development of Modular Microbiome Organoids

The human colon is home to more than a trillion microorganisms that modulate diverse gastrointestinal processes and pathophysiologies. Our understanding of how this gut ecosystem impacts human health, although evolving, is still in its nascent stages and has been slowed by the lack of accessible and scalable tools suitable to studying complex host-mucus-microbe interactions. In this work, we report a synthetic gel-like material capable of recapitulating the varied structural, mechanical, and biochemical profiles of native human colonic mucus to develop compositionally simple microbiome screening platforms with broad utility in microbiology and drug discovery. The viscous fibrillar material is realized through the templated assembly of a fluorine-rich amino acid at liquid-liquid phase separated interfaces. The fluorine-assisted mucus surrogate (FAMS) can be decorated with various mucins to serve as a habitat for microbial colonization and be integrated with human colorectal epithelial cells to generate multicellular artificial mucosae, which we refer to as a microbiome organoid. Notably, FAMS are made with inexpensive and commercially available materials, and can be generated using simple protocols and standard laboratory hardware. As a result, this platform can be broadly incorporated into various laboratory settings to advance our understanding of probiotic biology and inform in vivo approaches. If implemented into high throughput screening approaches, FAMS may represent a valuable tool in drug discovery to study compound metabolism and gut permeability, with an exemplary demonstration of this utility presented here.

Obstetrical health care inequities in a universally insured health care system

BACKGROUND

Racial and ethnic disparities in health care exist and are rooted in long-standing systemic inequities. These disparities result in significant excess health care expenditures and are due to complex interactions between patients, health care providers and systems, and social and environmental factors. In perinatal care, these inequities also exist, with Black patients being 3 to 4 times more likely to die of childbirth compared with White patients. Similar health care inequities may also exist in the Military Health System despite universal health care coverage, stable employment, and social programs that benefit military families.

OBJECTIVE

This study aimed to evaluate racial disparities in obstetrical outcomes in the Military Health System.

STUDY DESIGN

This is a retrospective cohort study of deliveries from 2019 to 2021 in the Military Health System, which provides obstetrical care for approximately 35,000 annual deliveries. The study was conducted using National Perinatal Information Center data on cesarean delivery, postpartum hemorrhage, and severe maternal morbidity by race and ethnicity from direct-care military hospitals representing tertiary care medical centers and community hospitals in the United States and abroad. Chi-square analyses and binary logistic regression were used to compare groups.

RESULTS

The cohort included 68,918 deliveries. Of these, 32,358 (47%) were White, 9594 (13.9%) Black, 3120 (4.5%) Asian Pacific Islander, 456 (0.7%) American Indian/Alaska Native, 19,543 (28.4%) other, 3976 (5.8%) unknown, 7096 (10.3%) Hispanic, 58,009 (84.2%) non-Hispanic, and 4399 (6.4%) other ethnicity. Rates of cesarean delivery were significantly higher for Black (30%; odds ratio, 1.44; 95% confidence interval, 1.37-1.52), Asian Pacific Islander (27%; odds ratio, 1.24; 95% confidence interval, 1.14-1.35), and other (26%; odds ratio, 1.20; 95% confidence interval, 1.15-1.25) compared with White race (23%) (P<.001). Postpartum hemorrhage rates were higher for Black (5.9%; odds ratio, 1.11; 95% confidence interval, 1.00-1.24) and Asian Pacific Islander (7.7%; odds ratio, 1.49; 95% confidence interval, 1.29-1.72) compared with White race (5.3%) (P<.001). Severe maternal morbidity was higher for Black (2.9%; odds ratio, 1.44; 95% confidence interval, 1.24-1.67), Asian Pacific Islander (2.9%; odds ratio, 1.45; 95% confidence interval, 1.15-1.82), and other (2.8%; odds ratio, 1.36; 95% confidence interval, 1.21-1.54) compared with White race (2.1%) (P<.001). For severe maternal morbidity excluding blood transfusions, rates were also significantly higher for Black (1%; odds ratio, 1.68; 95% confidence interval, 1.30-2.17) than for White race (0.6%) (P<.002). Hispanic ethnicity was associated with a lower rate of severe maternal morbidity excluding transfusions (0.5%; odds ratio, 0.68; 95% confidence interval, 0.48-0.98) compared with non-Hispanic ethnicity (0.7%) (P=.04).

CONCLUSION

Racial disparities in obstetrical outcomes exist in the Military Health System despite universal health care coverage, with significantly higher rates of cesarean delivery and severe maternal morbidity in Black, Asian Pacific Islander, and other races compared with White race. These findings suggest that these disparities are likely related to other factors or social determinants of health rather than availability of health care and insurance coverage. Further work should include investigation into such social determinants of health to address their causes, including systemic and structural barriers.

Improved Protocol for Reproducible Human Cortical Organoids Reveals Early Alterations in Metabolism with MAPT Mutations

Cerebral cortical-enriched organoids derived from human pluripotent stem cells (hPSCs) are valuable models for studying neurodevelopment, disease mechanisms, and therapeutic development. However, recognized limitations include the high variability of organoids across hPSC donor lines and experimental replicates. We report a 96-slitwell method for efficient, scalable, reproducible cortical organoid production. When hPSCs were cultured with controlled-release FGF2 and an SB431542 concentration appropriate for their TGFBR1 / ALK5 expression level, organoid cortical patterning and reproducibility were significantly improved. Well-patterned organoids included 16 neuronal and glial subtypes by single cell RNA sequencing (scRNA-seq), frequent neural progenitor rosettes and robust BCL11B+ and TBR1+ deep layer cortical neurons at 2 months by immunohistochemistry. In contrast, poorly-patterned organoids contain mesendoderm-related cells, identifiable by negative QC markers including COL1A2 . Using this improved protocol, we demonstrate increased sensitivity to study the impact of different MAPT mutations from patients with frontotemporal dementia (FTD), revealing early changes in key metabolic pathways.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

The FGF21 analog pegozafermin in severe hypertriglyceridemia: a randomized phase 2 trial

Pegozafermin, a long-acting glycopegylated analog of human fibroblast growth factor 21, is in development for the treatment of severe hypertriglyceridemia (SHTG) and nonalcoholic steatohepatitis. Here we report the results of a phase 2, double-blind, randomized, five-arm trial testing pegozafermin at four different doses (n = 67; 52 male) versus placebo (n = 18; 12 male) for 8 weeks in patients with SHTG (triglycerides (TGs), ≥500 mg dl-1 and ≤2,000 mg dl-1). Treated patients showed a significant reduction in median TGs for the pooled pegozafermin group versus placebo (57.3% versus 11.9%, difference versus placebo -43.7%, 95% confidence interval (CI): -57.1%, -30.3%; P < 0.001), meeting the primary endpoint of the trial. Reductions in median TGs ranged from 36.4% to 63.4% across all treatment arms and were consistent regardless of background lipid-lowering therapy. Results for secondary endpoints included significant decreases in mean apolipoprotein B and non-high-density lipoprotein cholesterol concentrations (-10.5% and -18.3% for pooled doses compared to 1.1% and -0.6% for placebo (95% CI: -21.5%, -2.0%; P = 0.019 and 95% CI: -30.7%, -5.1%; P = 0.007, respectively), as well as a significant decrease in liver fat fraction for pooled treatment (n = 17) versus placebo (n = 6; -42.2% pooled pegozafermin, -8.3% placebo; 95% CI: -60.9%, -8.7%; P = 0.012), as assessed in a magnetic resonance imaging sub-study. No serious adverse events were observed to be related to the study drug. If these results are confirmed in a phase 3 trial, pegozafermin could be a promising treatment for SHTG (ClinicalTrials.gov registration: NCT0441186).

Lysinoalanine crosslinking is a conserved post-translational modification in the spirochete flagellar hook

Spirochete bacteria cause Lyme disease, leptospirosis, syphilis and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) catalyzes the formation of covalent lysinoalanine (Lal) crosslinks between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. Although not necessary for hook assembly, Lal is required for motility of Td, presumably due to the stabilizing effect of the crosslink. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal crosslinked peptides in recombinant and in vivo -derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp.. Like with Td, a mutant strain of the Lyme disease pathogen Borreliella burgdorferi unable to form the crosslink has impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveals that the Lal crosslink is a conserved and necessary post-translational modification across the spirochete phylum and may thus represent an effective target for spirochete-specific antimicrobials.

Significance Statement

The phylum Spirochaetota contains bacterial pathogens responsible for a variety of diseases, including Lyme disease, syphilis, periodontal disease, and leptospirosis. Motility of these pathogens is a major virulence factor that contributes to infectivity and host colonization. The oral pathogen Treponema denticola produces a post-translational modification (PTM) in the form of a lysinoalanine (Lal) crosslink between neighboring subunits of the flagellar hook protein FlgE. Herein, we demonstrate that representative spirochetes species across the phylum all form Lal in their flagellar hooks. T. denticola and B. burgdorferi cells incapable of forming the crosslink are non-motile, thereby establishing the general role of the Lal PTM in the unusual type of flagellar motility evolved by spirochetes.

Mapping genetic effects on cell type-specific chromatin accessibility and annotating complex immune trait variants using single nucleus ATAC-seq in peripheral blood

Gene regulation is highly cell type-specific and understanding the function of non-coding genetic variants associated with complex traits requires molecular phenotyping at cell type resolution. In this study we performed single nucleus ATAC-seq (snATAC-seq) and genotyping in peripheral blood mononuclear cells from 13 individuals. Clustering chromatin accessibility profiles of 96,002 total nuclei identified 17 immune cell types and sub-types. We mapped chromatin accessibility QTLs (caQTLs) in each immune cell type and sub-type using individuals of European ancestry which identified 6,901 caQTLs at FDR < .10 and 4,220 caQTLs at FDR < .05, including those obscured from assays of bulk tissue such as with divergent effects on different cell types. For 3,941 caQTLs we further annotated putative target genes of variant activity using single cell co-accessibility, and caQTL variants were significantly correlated with the accessibility level of linked gene promoters. We fine-mapped loci associated with 16 complex immune traits and identified immune cell caQTLs at 622 candidate causal variants, including those with cell type-specific effects. At the 6q15 locus associated with type 1 diabetes, in line with previous reports, variant rs72928038 was a naïve CD4+ T cell caQTL linked to BACH2 and we validated the allelic effects of this variant on regulatory activity in Jurkat T cells. These results highlight the utility of snATAC-seq for mapping genetic effects on accessible chromatin in specific cell types.

Doom or Deliciousness: Challenges and Opportunities for Visualization in the Age of Generative Models

Generative text-to-image models (as exemplified by DALL-E, MidJourney, and Stable Diffusion) have recently made enormous technological leaps, demonstrating impressive results in many graphical domains-from logo design to digital painting to photographic composition. However, the quality of these results has led to existential crises in some fields of art, leading to questions about the role of human agency in the production of meaning in a graphical context. Such issues are central to visualization, and while these generative models have yet to be widely applied in visualization, it seems only a matter of time until their integration is manifest. Seeking to circumvent similar ponderous dilemmas, we attempt to understand the roles that generative models might play across visualization. We do so by constructing a framework that characterizes what these technologies offer at various stages of the visualization workflow, augmented and analyzed through semi-structured interviews with 21 experts from related domains. Through this work, we map the space of opportunities and risks that might arise in this intersection, identifying doomsday prophecies and delicious low-hanging fruits that are ripe for research.

From Studio to Rehab: A Debilitating Form of Anti-HMGCR Myopathy

Immune-mediated necrotizing myopathy is a subtype of immune-mediated myopathy associated with or without statin use. Statins, or HMG-CoA reductase inhibitors, are the most prescribed medications for dyslipidemia. The statin-associated myopathic syndromes range from asymptomatic elevations in creatine kinase to severe debilitating muscle weakness with associated rhabdomyolysis and elevated liver enzymes. Clinical improvement occurs upon discontinuation of statins, but some patients do not recover completely. Diagnostic tests include electromyography, muscle biopsy, myositis autoantibody panel, and antibodies against the HMGCR. Here, we present a case of anti-HMGCR-related myopathy associated with atorvastatin.

The impact of thromboelastography on patients with penetrating abdominal trauma requiring intensive care

BACKGROUND

Trauma-induced coagulopathy (TIC) is a complex multifaceted process which contributes to higher mortality rates in severely injured trauma patients. Thromboelastography (TEG) is effective in detecting TIC which assists in instituting goal-directed therapy as part of damage control resuscitation.

METHODS

This retrospective study included all adult patients over a 36-month period with penetrating abdominal trauma who required a laparotomy, blood products and admission for critical care. Analysis included demographics, admission data, 24-hour interventions, TEG parameters and 30-day outcomes.

RESULTS

Eighty-four patients with a median age of 28 years were included. The majority (93%; 78/84) suffered from a gunshot injury, with 75% (63/84) receiving a damage control laparotomy. Forty-eight patients (57%) had a TEG. Injury severity score and total fluid and blood product administered in the first 24 hours were all significantly higher in patients who had a TEG (p < 0.05). TEG profiles were: 42% (20/48) normal, 42% (20/48) hypocoagulable, 12% (6/48) hypercoagulable and 4% (2/48) mixed parameters. Fibrinolysis profiles were: 48% (23/48) normal, 44% (21/48) fibrinolysis shutdown and 8% (4/48) hyperfibrinolysis. Mortality rate was 5% (4/84) at 24 hours and 26% (22/84) at 30 days, with no difference between the two groups. High-grade complication rates, days on a ventilator and intensive care unit length of stay were all significantly higher in patients who did not have a TEG.

CONCLUSION

TIC is common in severely injured penetrating trauma patients. The usage of a thromboelastogram did not impact on 24-hour or 30-day mortality but did result in a decreased intensive care stay and a decreased high-grade complication rate.

Integrating genetics with single-cell multiomic measurements across disease states identifies mechanisms of beta cell dysfunction in type 2 diabetes

Dysfunctional pancreatic islet beta cells are a hallmark of type 2 diabetes (T2D), but a comprehensive understanding of the underlying mechanisms, including gene dysregulation, is lacking. Here we integrate information from measurements of chromatin accessibility, gene expression and function in single beta cells with genetic association data to nominate disease-causal gene regulatory changes in T2D. Using machine learning on chromatin accessibility data from 34 nondiabetic, pre-T2D and T2D donors, we identify two transcriptionally and functionally distinct beta cell subtypes that undergo an abundance shift during T2D progression. Subtype-defining accessible chromatin is enriched for T2D risk variants, suggesting a causal contribution of subtype identity to T2D. Both beta cell subtypes exhibit activation of a stress-response transcriptional program and functional impairment in T2D, which is probably induced by the T2D-associated metabolic environment. Our findings demonstrate the power of multimodal single-cell measurements combined with machine learning for characterizing mechanisms of complex diseases.

Sedation and Analgesia for Reduction of Pediatric Ileocolic Intussusception

Importance

Ileocolic intussusception is an important cause of intestinal obstruction in children. Reduction of ileocolic intussusception using air or fluid enema is the standard of care. This likely distressing procedure is usually performed without sedation or analgesia, but practice variation exists.

Objective

To characterize the prevalence of opioid analgesia and sedation and assess their association with intestinal perforation and failed reduction.

Design, Setting, and Participants

This cross-sectional study reviewed medical records of children aged 4 to 48 months with attempted reduction of ileocolic intussusception at 86 pediatric tertiary care institutions in 14 countries from January 2017 to December 2019. Of 3555 eligible medical records, 352 were excluded, and 3203 medical records were eligible. Data were analyzed in August 2022.

Exposures

Reduction of ileocolic intussusception.

Main outcomes and measures

The primary outcomes were opioid analgesia within 120 minutes of reduction based on the therapeutic window of IV morphine and sedation immediately before reduction of intussusception.

Results

We included 3203 patients (median [IQR] age, 17 [9-27] months; 2054 of 3203 [64.1%] males). Opioid use was documented in 395 of 3134 patients (12.6%), sedation 334 of 3161 patients (10.6%), and opioids plus sedation in 178 of 3134 patients (5.7%). Perforation was uncommon and occurred in 13 of 3203 patients (0.4%). In the unadjusted analysis, opioids plus sedation (odds ratio [OR], 5.92; 95% CI, 1.28-27.42; P = .02) and a greater number of reduction attempts (OR, 1.48; 95% CI, 1.03-2.11; P = .03) were significantly associated with perforation. In the adjusted analysis, neither of these covariates remained significant. Reductions were successful in 2700 of 3184 attempts (84.8%). In the unadjusted analysis, younger age, no pain assessment at triage, opioids, longer duration of symptoms, hydrostatic enema, and gastrointestinal anomaly were significantly associated with failed reduction. In the adjusted analysis, only younger age (OR, 1.05 per month; 95% CI, 1.03-1.06 per month; P < .001), shorter duration of symptoms (OR, 0.96 per hour; 95% CI, 0.94-0.99 per hour; P = .002), and gastrointestinal anomaly (OR, 6.50; 95% CI, 2.04-20.64; P = .002) remained significant.

Conclusions and Relevance

This cross-sectional study of pediatric ileocolic intussusception found that more than two-thirds of patients received neither analgesia nor sedation. Neither was associated with intestinal perforation or failed reduction, challenging the widespread practice of withholding analgesia and sedation for reduction of ileocolic intussusception in children.

The effects of a land-based home exercise program on surfing performance in recreational surfers

Surfing has become a popular, non-age dependent sport that can be performed at most beaches. Hence, coaches and athletes have recognised the importance of physical preparation to enhance athletic performance. The purpose of this study was to investigate the effects of a sport-specific, land-based-home exercise programme (LB-HEP) on sport-specific assessments related to surfing performance in recreational surfers. Twenty-two year-round recreational surfers divided into two groups: the exercise group (EG) performed the LB-HEP 3 times a week for 8 weeks while the control group (CG) maintained their current exercise. Both groups were instructed to continue surfing during the study period. Each surfer completed sport-specific measurements related to surfing demands both pre-test and post-test (8 weeks). There was a significant interactive effect of time and group (p = .009, η_p² =.298) on the surfer's performance questionnaire showing greater improvements in the EG. Additionally, the EG had an improvement on time to pop-up when compared to the CG (η_p² =.160). Based on the results, the LB-HEP is an effective training programme for all experience levels of recreational surfers to improve surfing performance measures short term.