Insulin-regulated serine and lipid metabolism drive peripheral neuropathy.

Diabetes represents a spectrum of disease in which metabolic dysfunction damages multiple organ systems including liver, kidneys and peripheral nerves1,2. Although the onset and progression of these co-morbidities are linked with insulin resistance, hyperglycaemia and dyslipidaemia3-7, aberrant non-essential amino acid (NEAA) metabolism also contributes to the pathogenesis of diabetes8-10. Serine and glycine are closely related NEAAs whose levels are consistently reduced in patients with metabolic syndrome10-14, but the mechanistic drivers and downstream consequences of this metabotype remain unclear. Low systemic serine and glycine are also emerging as a hallmark of macular and peripheral nerve disorders, correlating with impaired visual acuity and peripheral neuropathy15,16. Here we demonstrate that aberrant serine homeostasis drives serine and glycine deficiencies in diabetic mice, which can be diagnosed with a serine tolerance test that quantifies serine uptake and disposal. Mimicking these metabolic alterations in young mice by dietary serine or glycine restriction together with high fat intake markedly accelerates the onset of small fibre neuropathy while reducing adiposity. Normalization of serine by dietary supplementation and mitigation of dyslipidaemia with myriocin both alleviate neuropathy in diabetic mice, linking serine-associated peripheral neuropathy to sphingolipid metabolism. These findings identify systemic serine deficiency and dyslipidaemia as novel risk factors for peripheral neuropathy that may be exploited therapeutically.

Reappraising the Role of T Cell-Derived IFN-γ in Restriction of Mycobacterium tuberculosis in the Murine Lung.

T cells producing IFN-γ have long been considered a stalwart for immune protection against Mycobacterium tuberculosis (Mtb), but their relative importance to pulmonary immunity has been challenged by murine studies that achieved protection by adoptively transferred Mtb-specific IFN-γ-/- T cells. Using IFN-γ-/- T cell chimeric mice and adoptive transfer of IFN-γ-/- T cells into TCRß-/-δ-/- mice, we demonstrate that control of lung Mtb burden is in fact dependent on T cell-derived IFN-γ, and, furthermore, mice selectively deficient in T cell-derived IFN-γ develop exacerbated disease compared with T cell-deficient control animals, despite equivalent lung bacterial burdens. Deficiency in T cell-derived IFN-γ skews infected and bystander monocyte-derived macrophages to an alternative M2 phenotype and promotes neutrophil and eosinophil influx. Our studies support an important role for T cell-derived IFN-γ in pulmonary immunity against tuberculosis.

Assessing vaccine-mediated protection in an ultra-low dose Mycobacterium tuberculosis murine model.

Despite widespread immunization with Bacille-Calmette-Guérin (BCG), the only currently licensed tuberculosis (TB) vaccine, TB remains a leading cause of mortality globally. There are many TB vaccine candidates in the developmental pipeline, but the lack of a robust animal model to assess vaccine efficacy has hindered our ability to prioritize candidates for human clinical trials. Here we use a murine ultra-low dose (ULD) Mycobacterium tuberculosis (Mtb) challenge model to assess protection conferred by BCG vaccination. We show that BCG confers a reduction in lung bacterial burdens that is more durable than that observed after conventional dose challenge, curbs Mtb dissemination to the contralateral lung, and, in a small percentage of mice, prevents detectable infection. These findings are consistent with the ability of human BCG vaccination to mediate protection, particularly against disseminated disease, in specific human populations and clinical settings. Overall, our findings demonstrate that the ultra-low dose Mtb infection model can measure distinct parameters of immune protection that cannot be assessed in conventional dose murine infection models and could provide an improved platform for TB vaccine testing.

A Small Molecule RIG-I Agonist Serves as an Adjuvant to Induce Broad Multifaceted Influenza Virus Vaccine Immunity.

Retinoic acid-inducible gene I (RIG-I) is essential for activating host cell innate immunity to regulate the immune response against many RNA viruses. We previously identified that a small molecule compound, KIN1148, led to the activation of IFN regulatory factor 3 (IRF3) and served to enhance protection against influenza A virus (IAV) A/California/04/2009 infection. We have now determined direct binding of KIN1148 to RIG-I to drive expression of IFN regulatory factor 3 and NF-κB target genes, including specific immunomodulatory cytokines and chemokines. Intriguingly, KIN1148 does not lead to ATPase activity or compete with ATP for binding but activates RIG-I to induce antiviral gene expression programs distinct from type I IFN treatment. When administered in combination with a vaccine against IAV, KIN1148 induces both neutralizing Ab and IAV-specific T cell responses compared with vaccination alone, which induces comparatively poor responses. This robust KIN1148-adjuvanted immune response protects mice from lethal A/California/04/2009 and H5N1 IAV challenge. Importantly, KIN1148 also augments human CD8+ T cell activation. Thus, we have identified a small molecule RIG-I agonist that serves as an effective adjuvant in inducing noncanonical RIG-I activation for induction of innate immune programs that enhance adaptive immune protection of antiviral vaccination.

Decadal migration phenology of a long-lived Arctic icon keeps pace with climate change.

Animals migrate in response to seasonal environments, to reproduce, to benefit from resource pulses, or to avoid fluctuating hazards. Although climate change is predicted to modify migration, only a few studies to date have demonstrated phenological shifts in marine mammals. In the Arctic, marine mammals are considered among the most sensitive to ongoing climate change due to their narrow habitat preferences and long life spans. Longevity may prove an obstacle for species to evolutionarily respond. For species that exhibit high site fidelity and strong associations with migration routes, adjusting the timing of migration is one of the few recourses available to respond to a changing climate. Here, we demonstrate evidence of significant delays in the timing of narwhal autumn migrations with satellite tracking data spanning 21 y from the Canadian Arctic. Measures of migration phenology varied annually and were explained by sex and climate drivers associated with ice conditions, suggesting that narwhals are adopting strategic migration tactics. Male narwhals were found to lead the migration out of the summering areas, while females, potentially with dependent young, departed later. Narwhals are remaining longer in their summer areas at a rate of 10 d per decade, a similar rate to that observed for climate-driven sea ice loss across the region. The consequences of altered space use and timing have yet to be evaluated but will expose individuals to increasing natural changes and anthropogenic activities on the summering areas.

Glycocalyx engineering with heparan sulfate mimetics attenuates Wnt activity during adipogenesis to promote glucose uptake and metabolism.

Adipose tissue plays a crucial role in maintaining metabolic homeostasis by storing lipids and glucose from circulation as intracellular fat. As peripheral tissues like adipose tissue become insulin resistant, decompensation of blood glucose levels occurs causing type 2 diabetes (T2D). Currently, modulating the glycocalyx, a layer of cell-surface glycans, is an underexplored pharmacological treatment strategy to improve glucose homeostasis in T2D patients. Here, we show a novel role for cell-surface heparan sulfate (HS) in establishing glucose uptake capacity and metabolic utilization in differentiated adipocytes. Using a combination of chemical and genetic interventions, we identified that HS modulates this metabolic phenotype by attenuating levels of Wnt signaling during adipogenesis. By engineering, the glycocalyx of pre-adipocytes with exogenous synthetic HS mimetics, we were able to enhance glucose clearance capacity after differentiation through modulation of Wnt ligand availability. These findings establish the cellular glycocalyx as a possible new target for therapeutic intervention in T2D patients by enhancing glucose clearance capacity independent of insulin secretion.

HCMV UL8 interaction with ß-catenin and DVL2 regulates viral reactivation in CD34+ hematopoietic progenitor cells.

IMPORTANCE: CD34+ hematopoietic progenitor cells (HPCs) are an important cellular reservoir for latent human cytomegalovirus (HCMV). Several HCMV genes are expressed during latency that are involved with the maintenance of the viral genome in CD34+ HPC. However, little is known about the process of viral reactivation in these cells. Here, we describe a viral protein, pUL8, and its interaction and stabilization with members of the Wnt/ß-catenin pathway as an important component of viral reactivation. We further define that pUL8 and ß-catenin interact with DVL2 via a PDZ-binding domain, and loss of UL8 interaction with ß-catenin-DVL2 restricts viral reactivation. Our findings will be instrumental in understanding the molecular processes involved in HCMV reactivation in order to design new antiviral therapeutics.

Caregivers' and providers' perspectives of social and medical care after pediatric liver transplant: Results from the multicenter SOCIAL-Tx study.

Disparities exist in pediatric liver transplant (LT). We characterized barriers and facilitators to providing transplant and social care within pediatric LT clinics. This was a multicenter qualitative study. We oversampled caregivers reporting household financial strain, material economic hardship, or demonstrating poor health literacy. We also enrolled transplant team members. We conducted semistructured interviews with participants. Caregiver interviews focused on challenges addressing transplant and household needs. Transplant provider interviews focused on barriers and facilitators to providing social care within transplant teams. Interviews were recorded, transcribed, and coded according to the Capability, Opportunity, Motivation-Behavior model. We interviewed 27 caregivers and 27 transplant team members. Fifty-two percent of caregivers reported a household income <$60,000, and 62% reported financial resource strain. Caregivers reported experiencing (1) high financial burdens after LT, (2) added caregiving labor that compounds the financial burden, (3) dependency on their social network's generosity for financial and logistical support, and (4) additional support being limited to the perioperative period. Transplant providers reported (1) relying on the pretransplant psychosocial assessment for identifying social risks, (2) discomfort initiating social risk discussions in the post-transplant period, (3) reliance on social workers to address new social risks, and (4) social workers feeling overburdened by quantity and quality of the social work referrals. We identified barriers to providing effective social care in pediatric LT, primarily a lack of comfort in assessing and addressing new social risks in the post-transplant period. Addressing these barriers should enhance social care delivery and improve outcomes for these children.

Lactobacillus from the Altered Schaedler Flora maintain IFNγ homeostasis to promote behavioral stress resilience.

The gut microbiome consists of trillions of bacteria, fungi, and viruses that inhabit the digestive tract. These communities are sensitive to disruption from environmental exposures ranging from diet changes to illness. Disruption of the community of lactic acid producing bacteria, Lactobaccillacea, has been well documented in mood disorders and stress exposure. In fact, oral supplement with many Lactobacillus species can ameliorate these effects, preventing depression- and anxiety-like behavior. Here, we utilize a gnotobiotic mouse colonized with the Altered Schaedler Flora to remove the two native species of Lactobaccillacea: L. intestinalis and L. murinus. Using this microbial community, we found that the Lactobacillus species themselves, and not the disrupted microbial communities are protective from environmental stressors. Further, we determine that Lactobaccillacea are maintaining homeostatic IFNγ levels which are mediating these behavioral and circuit level responses. By utilizing the Altered Schaedler Flora, we have gained new insight into how probiotics influence behavior and provide novel methods to study potential therapies to treat mood disorders.

Stress-induced mucin 13 reductions drive intestinal microbiome shifts and despair behaviors.

Depression is a prevalent psychological condition with limited treatment options. While its etiology is multifactorial, both chronic stress and changes in microbiome composition are associated with disease pathology. Stress is known to induce microbiome dysbiosis, defined here as a change in microbial composition associated with a pathological condition. This state of dysbiosis is known to feedback on depressive symptoms. While studies have demonstrated that targeted restoration of the microbiome can alleviate depressive-like symptoms in mice, translating these findings to human patients has proven challenging due to the complexity of the human microbiome. As such, there is an urgent need to identify factors upstream of microbial dysbiosis. Here we investigate the role of mucin 13 as an upstream mediator of microbiome composition changes in the context of stress. Using a model of chronic stress, we show that the glycocalyx protein, mucin 13, is selectively reduced after psychological stress exposure. We further demonstrate that the reduction of Muc13 is mediated by the Hnf4 transcription factor family. Finally, we determine that deleting Muc13 is sufficient to drive microbiome shifts and despair behaviors. These findings shed light on the mechanisms behind stress-induced microbial changes and reveal a novel regulator of mucin 13 expression.

Patient Acceptability of Telehealth Medication Abortion Care in the United States, 2021‒2022: A Cohort Study.

Objectives. Despite the recent expansion of direct-to-patient telehealth abortion care in the United States, patient experiences with the service are not well understood. Methods. We described care experiences of 1600 telehealth abortion patients in 2021 to 2022 and used logistic regression to explore differences by race or ethnicity and between synchronous (phone or video) and asynchronous (secure messaging) telehealth abortion care. Results. Most patients trusted the provider (98%), felt telehealth was the right decision (96%), felt cared for (92%), and were very satisfied (89%). Patients most commonly cited privacy (76%), timeliness (74%), and staying at home (71%) as benefits. The most commonly reported drawback was initial uncertainty about whether the service was legitimate (38%). Asian patients were less likely to be very satisfied than White patients (79% vs 90%; P = .008). Acceptability was high for both synchronous and asynchronous care. Conclusions. Telehealth abortion care is highly acceptable, and benefits include privacy and expediency. Public Health Implications. Telehealth abortion can expand abortion access in an increasingly restricted landscape while maintaining patient-centered care. (Am J Public Health. 2024;114(2):241-250. https://doi.org/10.2105/AJPH.2023.307437).

Sequential administration of peripheral nerve blocks and onabotulinumtoxinA for the treatment of chronic migraine and other headache disorders-A retrospective tolerability and safety study.

OBJECTIVE: To determine the tolerability and safety of concurrent peripheral nerve blocks and onabotulinumtoxinA treatment during a single outpatient clinic procedure visit. BACKGROUND: Procedural interventions are available for the treatment of headache disorders. OnabotulinumtoxinA and peripheral nerve blocks are used as alternatives or in addition to oral therapies to reduce the frequency and intensity of migraine attacks. There is currently a lack of safety data focusing on the sequential administration of local anesthetic via peripheral nerve blocks and onabotulinumtoxinA during a single clinical encounter for the treatment of headache. The primary aim of the study was to determine the safety and tolerability of concurrent peripheral nerve blockade and onabotulinumtoxinA injections during a single outpatient clinic procedure visit. We hypothesized that the dual intervention would be safe and well tolerated by patients with chronic migraine and other headache disorders. METHODS: A retrospective chart review was performed using clinical data from patients seen by multiple providers over a 16-month timeframe at one outpatient headache clinic. Patients were identified by procedure codes and those receiving peripheral nerve block(s) and onabotulinumtoxinA injections during a single encounter within the study period were eligible for inclusion. Inclusion criteria were (1) patients 18 years and older who were (2) receiving both peripheral nerve blocks and onabotulinumtoxinA injections for the treatment of chronic migraine. Patients were excluded if they were under age 18, received their procedure outside of the clinic (emergency room, inpatient ward), or were receiving sphenopalatine ganglion blocks. Age- and sex-matched patients who received one procedure, either peripheral nerve blocks or onabotulinumtoxinA, were used for control. The primary outcome of this safety study was the number of adverse events that occurred in the dual intervention group compared to the single intervention control arms. Information regarding adverse events was gathered via retrospective chart review. If an adverse event was recorded, it was then graded by the reviewer utilizing the Common Terminology Criteria for Adverse Events ranging from Grade 1 Mild Event to Grade 5 Death. Additionally, it was noted whether the adverse event led to treatment discontinuation. RESULTS: In total, 375 patients were considered eligible for inclusion in the study. After age and sex matching of controls, 131 patients receiving dual intervention were able to be compared to 131 patients receiving onabotulinumtoxinA alone and 104 patients receiving dual intervention were able to be compared to 104 patients receiving peripheral nerve block(s) alone. The primary endpoint analysis showed no significant difference in total adverse events between dual intervention compared to nerve blocks alone or onabotulinumtoxinA alone. The number of adverse events that led to treatment discontinuation approached but did not reach statistical significance for those receiving dual intervention versus onabotulinumtoxinA alone in the number of adverse events that led to treatment termination (4.6%, 6/131 vs. 0.8%, 1/131, p = 0.065); however, the number of patients who discontinued therapy was not significantly different between those groups (2.3%, 3/131 vs. 0.8%, 1/131; p = 0.314; odds ratio 0.3 [0-3.2]; p = 0.338). CONCLUSIONS: In this retrospective chart review, there was no significant difference in adverse events or therapy discontinuation between patients receiving sequential peripheral nerve block(s) and onabotulinumtoxinA injections versus those receiving either peripheral nerve block(s) or onabotulinumtoxinA injections alone. As a result, we concluded that the combination procedure is likely safe and well tolerated in routine clinical practice.

Sterilization Effects on Nitric Oxide-Releasing Glucose Sensors.

Nitric oxide (NO) release from S-nitrosothiol-modified mesoporous silica nanoparticles imbedded in the diffusion limiting layer of a glucose sensor has been demonstrated as an effective strategy for mitigating the foreign body response common to sensor implantation, resulting in improved analytical performance. With respect to potential clinical translation of this approach, the effects of sterilization on NO-releasing biosensors require careful evaluation, as NO donor chemistry is sensitive to temperature and environment. Herein, we evaluated the influence of multiple sterilization methods on 1) sterilization success; 2) NO payload; and 3) sensor performance to establish the commercialization potential of NO-releasing glucose sensors. Sensors were treated with ethylene oxide gas, the most common sterilization method for intricate medical devices, which led to undesirable (i.e., premature) release of NO. To reduce NO loss, alternative sterilization methods that were studied included exposure to ultraviolet (UV) light and immersion in 70% ethanol (EtOH). Sterilization cycle times required to reach a 10-6 sterility assurance level were determined for both UV light and 70% EtOH against Gram-negative and -positive bacteria. The longest sterilization cycle times (258 s and 628 s for 70% EtOH and UV light, respectively) resulted in a negligible impact on benchtop sensor performance. However, sterilization with 70% ethanol resulted in a reduced NO-release duration. Ultraviolet light exposure for ~10 min proved successful at eliminating bacteria without compromising NO payloads or durations and presents as the most promising method for sterilization of these sensors. In addition, storage of NO-releasing sensor membranes at -20 and -80°C resulted in preservation of NO release for 6 and 12 months, respectively.

CAR and CSTR Cardiac Computed Tomography (CT) Practice Guidelines: Part 2-Non-Coronary Imaging.

The cardiac computed tomography (CT) practice guidelines provide an updated review of the technological improvements since the publication of the first Canadian Association of Radiologists (CAR) cardiac CT practice guidelines in 2009. An overview of the current evidence supporting the use of cardiac CT in the most common clinical scenarios, standards of practice to optimize patient preparation and safety as well as image quality are described. Coronary CT angiography (CCTA) is the focus of Part I. In Part II, an overview of cardiac CT for non-coronary indications that include valvular and pericardial imaging, tumour and mass evaluation, pulmonary vein imaging, and imaging of congenital heart disease for diagnosis and treatment monitoring are discussed. The guidelines are intended to be relevant for community hospitals and large academic centres with established cardiac CT imaging programs.

CAR and CSTR Cardiac Computed Tomography (CT) Practice Guidelines: Part 1 Coronary CT Angiography (CCTA).

Imaging the heart is one of the most technically challenging applications of Computed Tomography (CT) due to the presence of cardiac motion limiting optimal visualization of small structures such as the coronary arteries. Electrocardiographic gating during CT data acquisition facilitates motion free imaging of the coronary arteries. Since publishing the first version of the Canadian Association of Radiologists (CAR) cardiac CT guidelines, many technological advances in CT hardware and software have emerged necessitating an update. The goal of these cardiac CT practice guidelines is to present an overview of the current evidence supporting the use of cardiac CT in various clinical scenarios and to outline standards of practice for patient safety and quality of care when establishing a cardiac CT program in Canada.

CETARS/CAR Practice Guideline on Imaging the Pregnant Trauma Patient.

Imaging of pregnant patients who sustained trauma often causes fear and confusion among patients, their families, and health care professionals regarding the potential for detrimental effects from radiation exposure to the fetus. Unnecessary delays or potentially harmful avoidance of the justified imaging studies may result from this understandable anxiety. This guideline was developed by the Canadian Emergency, Trauma and Acute Care Radiology Society (CETARS) and the Canadian Association of Radiologists (CAR) Working Group on Imaging the Pregnant Trauma Patient, informed by a literature review as well as multidisciplinary expert panel opinions and discussions. The working group included academic subspecialty radiologists, a trauma team leader, an emergency physician, and an obstetriciangynaecologist/maternal fetal medicine specialist, who were brought together to provide updated, evidence-based recommendations for the imaging of pregnant trauma patients, including patient safety aspects (eg, radiation and contrast concerns) and counselling, initial imaging in maternal trauma, specific considerations for the use of fluoroscopy, angiography, and magnetic resonance imaging. The guideline strives to achieve clarity and prevent added anxiety in an already stressful situation of injury to a pregnant patient, who should not be imaged differently.

Endocrinology/Primary Care Pharmacy Collaboration vs Endocrinology Care Alone in Patients With Type 2 Diabetes and A1c >9.

Background: Type 2 diabetes (T2D) requires close collaboration between patients and their care management team, often including endocrinology. Primary care pharmacist impact on diabetes management in collaboration with endocrinology is not well established. Objective: To assess if pharmacy and endocrinology collaboration results in a greater A1c reduction in patients with T2D vs endocrinology alone. Methods: This retrospective, observational cohort study was conducted in adult outpatients with T2D and baseline A1c >9% who saw endocrinology within 1 year preceding the study period (January 1, 2021 to January 1, 2022). Patients were included if they had a follow-up A1c 6 months (±90 days) from index date and completed at least 1 endocrinology visit during the study period. Patients managed by endocrinology/primary care pharmacist collaboration (Endo/PharmD) were compared with those who received endocrinology care alone (Endo). Primary outcome was change in A1c from baseline to 6 months. Secondary outcomes included total number of completed visits and percentage of patients achieving A1c <6.5%, <7%, <8%, and <9% between groups at 6 months. Results: A total of 418 patients were included (22 Endo/PharmD, 396 Endo). The change in follow-up A1c was not significantly different between groups, -0.481% (standard error [SE] = 0.396); P = 0.6179. Endo/PharmD patients had significantly more provider visits during the study period (5.3 ± 2.3 vs 2.3 ± 1.2; P < 0.001). No significant difference was observed in odds of A1c goal attainment between groups at 6 months. Conclusion and Relevance: Endocrinology/primary care pharmacist collaboration occurred infrequently but was associated with a trend toward greater A1c reduction in patients with T2D and A1c >9%.

A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes: Integrated analysis of data from the MedLey randomised controlled trial and the EPIC-InterAct case-cohort study.

BACKGROUND: Self-reported adherence to the Mediterranean diet has been modestly inversely associated with incidence of type 2 diabetes (T2D) in cohort studies. There is uncertainty about the validity and magnitude of this association due to subjective reporting of diet. The association has not been evaluated using an objectively measured biomarker of the Mediterranean diet. METHODS AND FINDINGS: We derived a biomarker score based on 5 circulating carotenoids and 24 fatty acids that discriminated between the Mediterranean or habitual diet arms of a parallel design, 6-month partial-feeding randomised controlled trial (RCT) conducted between 2013 and 2014, the MedLey trial (128 participants out of 166 randomised). We applied this biomarker score in an observational study, the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study, to assess the association of the score with T2D incidence over an average of 9.7 years of follow-up since the baseline (1991 to 1998). We included 22,202 participants, of whom 9,453 were T2D cases, with relevant biomarkers from an original case-cohort of 27,779 participants sampled from a cohort of 340,234 people. As a secondary measure of the Mediterranean diet, we used a score estimated from dietary-self report. Within the trial, the biomarker score discriminated well between the 2 arms; the cross-validated C-statistic was 0.88 (95% confidence interval (CI) 0.82 to 0.94). The score was inversely associated with incident T2D in EPIC-InterAct: the hazard ratio (HR) per standard deviation of the score was 0.71 (95% CI: 0.65 to 0.77) following adjustment for sociodemographic, lifestyle and medical factors, and adiposity. In comparison, the HR per standard deviation of the self-reported Mediterranean diet was 0.90 (95% CI: 0.86 to 0.95). Assuming the score was causally associated with T2D, higher adherence to the Mediterranean diet in Western European adults by 10 percentiles of the score was estimated to reduce the incidence of T2D by 11% (95% CI: 7% to 14%). The study limitations included potential measurement error in nutritional biomarkers, unclear specificity of the biomarker score to the Mediterranean diet, and possible residual confounding. CONCLUSIONS: These findings suggest that objectively assessed adherence to the Mediterranean diet is associated with lower risk of T2D and that even modestly higher adherence may have the potential to reduce the population burden of T2D meaningfully. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000602729 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363860.

Multilevel Determinants of Digital Health Equity: A Literature Synthesis to Advance the Field.

Current digital health approaches have not engaged diverse end users or reduced health or health care inequities, despite their promise to deliver more tailored and personalized support to individuals at the right time and the right place. To achieve digital health equity, we must refocus our attention on the current state of digital health uptake and use across the policy, system, community, individual, and intervention levels. We focus here on (a) outlining a multilevel framework underlying digital health equity; (b) summarizingfive types of interventions/programs (with example studies) that hold promise for advancing digital health equity; and (c) recommending future steps for improving policy, practice, and research in this space.

"Candidatus Nealsonbacteria" Are Likely Biomass Recycling Ectosymbionts of Methanogenic Archaea in a Stable Benzene-Degrading Enrichment Culture.

The Candidate Phyla Radiation (CPR), also referred to as superphylum Patescibacteria, is a very large group of bacteria with no pure culture representatives discovered by 16S rRNA sequencing or genome-resolved metagenomic analyses of environmental samples. Within the CPR, candidate phylum Parcubacteria, previously referred to as OD1, is prevalent in anoxic sediments and groundwater. Previously, we had identified a specific member of the Parcubacteria (referred to as DGGOD1a) as an important member of a methanogenic benzene-degrading consortium. Phylogenetic analyses herein place DGGOD1a within the clade "Candidatus Nealsonbacteria." Because of its persistence over many years, we hypothesized that "Ca. Nealsonbacteria" DGGOD1a must play an important role in sustaining anaerobic benzene metabolism in the consortium. To try to identify its growth substrate, we amended the culture with a variety of defined compounds (pyruvate, acetate, hydrogen, DNA, and phospholipid), as well as crude culture lysate and three subfractions thereof. We observed the greatest (10-fold) increase in the absolute abundance of "Ca. Nealsonbacteria" DGGOD1a only when the consortium was amended with crude cell lysate. These results implicate "Ca. Nealsonbacteria" in biomass recycling. Fluorescence in situ hybridization and cryogenic transmission electron microscope images revealed that "Ca. Nealsonbacteria" DGGOD1a cells were attached to larger archaeal Methanothrix cells. This apparent epibiont lifestyle was supported by metabolic predictions from a manually curated complete genome. This is one of the first examples of bacterial-archaeal episymbiosis and may be a feature of other "Ca. Nealsonbacteria" found in anoxic environments. IMPORTANCE An anaerobic microbial enrichment culture was used to study members of candidate phyla that are difficult to grow in the lab. We were able to visualize tiny "Candidatus Nealsonbacteria" cells attached to a large Methanothrix cell, revealing a novel episymbiosis.