Expanding salivary biomarker detection by creating a synthetic neuraminic acid sensor via chimeragenesis.

Accurate and timely diagnosis of oral squamous cell carcinoma (OSCC) is crucial in preventing its progression to advanced stages with a poor prognosis. As such, the construction of sensors capable of detecting previously established disease biomarkers for the early and non-invasive diagnosis of this and many other conditions has enormous therapeutic potential. In this work, we apply synthetic biology techniques for the development of a whole-cell biosensor (WCB) that leverages the physiology of engineered bacteria in vivo to promote the expression of an observable effector upon detection of a soluble molecule. To this end, we have constructed a bacterial strain expressing a novel chimeric transcription factor (Sphnx) for the detection of N-acetylneuraminic acid (Neu5Ac), a salivary biomolecule correlated with the onset of OSCC. This WCB serves as the proof-of-concept of a platform that can eventually be applied to clinical screening panels for a multitude of oral and systemic medical conditions whose biomarkers are present in saliva.

AP2A2 mutation and defective endocytosis in a Malian family with hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) comprises a large group of neurogenetic disorders characterized by progressive lower extremity spasticity. Neurological evaluation and genetic testing were completed in a Malian family with early-onset HSP. Three children with unaffected consanguineous parents presented with symptoms consistent with childhood-onset complicated HSP. Neurological evaluation found lower limb weakness, spasticity, dysarthria, seizures, and intellectual disability. Brain MRI showed corpus callosum thinning with cortical and spinal cord atrophy, and an EEG detected slow background in the index patient. Whole exome sequencing identified a homozygous missense variant in the adaptor protein (AP) complex 2 alpha-2 subunit (AP2A2) gene. Western blot analysis showed reduced levels of AP2A2 in patient-iPSC derived neuronal cells. Endocytosis of transferrin receptor (TfR) was decreased in patient-derived neurons. In addition, we observed increased axon initial segment length in patient-derived neurons. Xenopus tropicalis tadpoles with ap2a2 knockout showed cerebral edema and progressive seizures. Immunoprecipitation of the mutant human AP-2-appendage alpha-C construct showed defective binding to accessory proteins. We report AP2A2 as a novel genetic entity associated with HSP and provide functional data in patient-derived neuron cells and a frog model. These findings expand our understanding of the mechanism of HSP and improve the genetic diagnosis of this condition.

Bridging the gap between in vitro and in vivo models: a way forward to clinical translation of mitochondrial transplantation in acute disease states.

Mitochondrial transplantation and transfer are being explored as therapeutic options in acute and chronic diseases to restore cellular function in injured tissues. To limit potential immune responses and rejection of donor mitochondria, current clinical applications have focused on delivery of autologous mitochondria. We recently convened a Mitochondrial Transplant Convergent Working Group (CWG), to explore three key issues that limit clinical translation: (1) storage of mitochondria, (2) biomaterials to enhance mitochondrial uptake, and (3) dynamic models to mimic the complex recipient tissue environment. In this review, we present a summary of CWG conclusions related to these three issues and provide an overview of pre-clinical studies aimed at building a more robust toolkit for translational trials.

Flanking Domains Modulate α-Synuclein Monomer Structure: A Molecular Dynamics Domain Deletion Study.

Aggregates of misfolded α-synuclein proteins (asyn) are key markers of Parkinson's disease. Asyn proteins have three domains: an N-terminal domain, a hydrophobic NAC core implicated in aggregation, and a proline-rich C-terminal domain. Proteins with truncated C-terminal domains are known to be prone to aggregation and suggest that studying domain-domain interactions in asyn monomers could help elucidate the role of the flanking domains in modulating protein structure. To this end, we used Gaussian accelerated molecular dynamics (GAMD) to simulate wild-type (WT), N-terminal truncated (DN), C-terminal truncated (ΔC), and isolated NAC domain variants (isoNAC). Using clustering and contact analysis, we found that N- and C-terminal domains interact via electrostatic interactions, while the NAC and N-terminal domains interact through hydrophobic contacts. Our work also suggests that the C-terminal domain does not interact directly with the NAC domain but instead interacts with the N-terminal domain. Removal of the N-terminal domain led to increased contacts between NAC and C-terminal domains and the formation of interdomain ß-sheets. Removal of either flanking domain also resulted in increased compactness of every domain. We also found that the contacts between flanking domains results in an electrostatic potential (ESP) that could possibly lead to favorable interactions with anionic lipid membranes. Removal of the C-terminal domain disrupts the ESP in a way that is likely to over-stabilize protein-membrane interactions. All of this suggests that one of the roles of the flanking domains may be to modulate the protein structure in a way that helps maintain elongation, hide hydrophobic residue from the solvent, and maintain an ESP that aids favorable interactions with the membrane.

The association of extreme environmental heat with incidence and outcomes of out-of-hospital cardiac arrest in British Columbia: A time series analysis.

Background: The impact of extreme heat on out-of-hospital cardiac arrest (OHCA) incidence and outcomes is under-studied. We investigated OHCA incidence and outcomes over increasing temperatures. Methods: We included non-traumatic EMS (Emergency Medical Services)-assessed OHCAs in British Columbia during the warm seasons of 2020-2021. We fit a time-series quasi-Poisson generalized linear model to estimate the association between temperature and incidence of both EMS-assessed, EMS-treated, and EMS-untreated OHCAs. Second, we employed a logistic regression model to estimate the association between "heatwave" periods (defined as a daily mean temperature > 99th percentile for ≥ 2 consecutive days, plus 3 lag days) with survival and favourable neurological outcomes (cerebral performance category ≤ 2) at hospital discharge. Results: Of 5478 EMS-assessed OHCAs, 2833 were EMS-treated. OHCA incidence increased with increasing temperatures, especially exceeding a daily mean temperature of 25 °C Compared to the median daily mean temperature (16.9 °C), the risk of EMS-assessed (relative risk [RR] 3.7; 95%CI 3.0-4.6), EMS-treated (RR 2.9; 95%CI 2.2-3.9), and EMS-untreated (RR 4.3; 95%CI 3.2-5.7) OHCA incidence were higher during days with a temperature over the 99th percentile. Of EMS-treated OHCAs, during the heatwave (n = 179) and non-heatwave (n = 2654) periods, 4 (2.2%) and 270 (10%) survived and 4 (2.2%) and 241 (9.2%) had favourable neurological outcomes, respectively. Heatwave period OHCAs had decreased odds of survival (adjusted OR 0.28; 95%CI 0.10-0.79) and favourable neurological outcome (adjusted OR 0.31; 95%CI 0.11-0.89) at hospital discharge, compared to other periods. Conclusion: Extreme heat was associated with a higher incidence of OHCA, and lower odds of survival and favourable neurological status at hospital discharge.

FANCA c.3624C>T (p.Ser1208=) is a hypomorphic splice variant associated with delayed onset of Fanconi anemia.

ABSTRACT: Fanconi anemia (FA) is a hereditary, DNA repair deficiency disorder caused by pathogenic variants in any 1 of 22 known genes (FANCA-FANCW). Variants in FANCA account for nearly two-thirds of all patients with FA. Clinical presentation of FA can be heterogeneous and include congenital abnormalities, progressive bone marrow failure, and predisposition to cancer. Here, we describe a relatively mild disease manifestation among 6 individuals diagnosed with FA, each compound heterozygous for 1 established pathogenic FANCA variant and 1 FANCA exon 36 variant, c.3624C>T. These individuals had delayed onset of hematological abnormalities, increased survival, reduced incidence of cancer, and improved fertility. Although predicted to encode a synonymous change (p.Ser1208=), the c.3624C>T variant causes a splicing error resulting in a FANCA transcript missing the last 4 base pairs of exon 36. Deep sequencing and quantitative reverse transcription polymerase chain reaction analysis revealed that 6% to 10% of the FANCA transcripts included the canonical splice product, which generated wild-type FANCA protein. Consistently, functional analysis of cell lines from the studied individuals revealed presence of residual FANCD2 ubiquitination and FANCD2 foci formation, better cell survival, and decreased late S/G2 accumulation in response to DNA interstrand cross-linking agent, indicating presence of residual activity of the FA repair pathway. Thus, the c.3624C>T variant is a hypomorphic allele, which contributes to delayed manifestation of FA disease phenotypes in individuals with at least 1 c.3624C>T allele.

External Validation of the Post-Concussion Symptoms Rule for Predicting Mild Traumatic Brain Injury Outcome.

Persistent symptoms are common after a mild traumatic brain injury (mTBI). The Post-Concussion Symptoms (PoCS) Rule is a newly developed clinical decision rule for the prediction of persistent post-concussion symptoms (PPCS) 3 months after an mTBI. The PoCS Rule includes assessment of demographic and clinical characteristics and headache presence in the emergency department (ED), and follow-up assessment of symptoms at 7 days post-injury using two thresholds (lower/higher) for symptom scoring. We examined the PoCS Rule in an independent sample. We analyzed a clinical trial that recruited participants with mTBI from EDs in Greater Vancouver, Canada. The primary analysis used data from 236 participants, who were randomized to a usual care control group, and completed the Rivermead Postconcussion Symptoms Questionnaire at 3 months. The primary outcome was PPCS, as defined by the PoCS authors. We assessed the overall performance of the PoCS rule (area under the receiver operating characteristic curve [AUC]), sensitivity, and specificity. More than 40% of participants (median age 38 years, 59% female) reported PPCS at 3 months. Most participants (88%) were categorized as being at medium risk based on the ED assessment, and a majority were considered as being at high risk according to the final PoCS Rule (81% using a lower threshold and 72% using a higher threshold). The PoCS Rule showed a sensitivity of 93% (95% confidence interval [CI], 88-98; lower threshold) and 85% (95% CI, 78-92; higher threshold), and a specificity of 28% (95% CI, 21-36) and 37% (95% CI, 29-46), respectively. The overall performance was modest (AUC 0.61, 95% CI 0.59, 0.65). In conclusion, the PoCS Rule was sensitive for PPCS, but had a low specificity in our sample. Follow-up assessment of symptoms can improve risk stratification after mTBI.

In situ mycoremediation of acid rain and heavy metals co-contaminated soil through microbial inoculation with Pleurotus ostreatus.

The combined pollution of acid rain and heavy metals in soil is a pressing environmental problem, especially in the regions with large-scale heavy industrial production activities. Low remediation efficiency and weak long-lasting stability are major challenges when disposing the heavy metals contaminated soil in acid rain polluted sites. Herein, a specific microbe, strain CT13 was isolated and domesticated to exhibit high tolerance to both acid rain and cadmium (Cd). Then, an in situ mycoremediation method by adopting a bioaugmentation technology of strain CT13 inoculation with Pleurotus ostreatus was developed. The remediation performance was investigated in acidic conditions with Cd concentrations in soil ranging from 0 to 15 mg/kg. While most of the bacteria strains (e.g. strain CT6/13) significantly improved the dry weight of mushroom and Cd accumulation in neutral environment, the performance of strain CT6 was remarkably deteriorated in acid rain environment. In contrast, strain CT13 maintained its behavior in acidic conditions, displaying ∼30 % and 150 % enhancements (vs the neutral environment) in the dry weight of mushroom and Cd accumulation, respectively. In addition, inoculation of strain CT13 led to significant reductions in the content of superoxide dismutase, peroxidase and lipid peroxidation in the fruiting body of P. ostreatus, indicating an improvement in the mushroom's tolerance to both acid rain and heavy metals. The synergistic effect of strain CT13 and P. ostreatus realized the significant improvement in soil remediation efficiency and long-lasting stability in acidic conditions, providing valuable insights into the remediation of heavy metal contaminated soil in the regions affected by acid rain.

Evaluating Oncologists' Practice Patterns and Decision-Making in Locally Advanced or Metastatic Urothelial Carcinoma: The US Physician PARADIGM Study.

BACKGROUND: The treatment landscape for locally advanced/metastatic urothelial carcinoma (la/mUC) has evolved. This study examined US prescribing patterns and clinical decision-making for first-line (1L) and first-line maintenance (1LM) treatment. MATERIALS AND METHODS: US-based oncologists (N = 150) completed an online survey on patient demographics, practice patterns, and important factors considered in 1L/1LM selection. Multivariable logistic regression was used to assess factors associated with more vs less frequent 1L/1LM prescribing. RESULTS: Physician reports estimated that 23% of patients with la/mUC had not received any systemic therapy in the previous 6 months; however, 46% received 1L, 32% received second-line, and 22% received subsequent-line systemic treatments. Of patients who were receiving 1L treatment, 72% were estimated to be receiving 1L platinum-based chemotherapy. Around 69% of patients eligible for 1LM received the treatment. Physicians categorized as frequent prescribers reported overall survival (OS), disease control rate (DCR), and rate of grade 3/4 adverse events (AEs) as factors associated with 1L treatment selection (all P < .05). OS, rate of grade 3/4 immune-mediated AEs, and inclusion in institutional guidelines were reported as attributes used in 1LM treatment selection (all P < .05). Multivariable analysis revealed OS, DCR, and rate of grade 3/4 AEs as important factors in oncologists' 1L treatment selection; academic practice setting and use of Response Evaluation Criteria in Solid Tumors version 1.1 were associated with 1LM use (all P < .05). CONCLUSION: OS and AEs were found to be relevant factors associated with offering 1L and 1LM treatment. Variability exists in physicians' decision-making in the real-world setting for la/mUC.

Transfer-based nuclear magnetic resonance uncovers unique mechanisms for protein-polymer and protein-nanoparticle binding behavior.

Nanoparticle-based drug delivery systems have shown increasing popularity as a means to improve patient outcomes by improving the effectiveness of active pharmaceutical ingredients (APIs). Similarly, nanoparticles have shown success in targeting alternative routes of API administration, such as applying mucoadhesion or mucopenetration to mucosal drug delivery to enhance uptake. While there are many promising examples of mucoadhesive nanomedicines in literature, there are also many examples of contradictory mucoadhesive binding behavior, most prominently in cases using the same nanoparticle materials. We have uncovered mechanistic insights in polymer-protein binding systems using nOe transfer-based NMR and sought to leverage them to explore nanoparticle-protein interactions. We tested several polymer-coated nanoparticles and micellar polymer nanoparticles and evaluated their binding with mucin proteins. We uncovered that the composition and interaction intimacy of polymer moieties that promote mucin binding change when the polymers are incorporated onto nanoparticle surfaces compared to polymer in solution. This change from solution state to nanoparticle coating can enable switching of behavior of these materials from inert to binding, as we observed in polyvinyl pyrrolidone. We also found the nanoparticle core was influential in determining the binding fate of polymer materials, whereas the nanoparticle size did not possess a clear correlation in the ranges we tested (60-270 nm). These experiments demonstrate that identical polymers may switch their binding behavior to mucin as a function of conformational changes that are induced by incorporating the polymers onto the surface of nanoparticles. These NMR-derived insights could be further leveraged to optimize nanoparticle formulations and guide polymer-mediated mucoadhesion.

Concordance between 8-1-1 HealthLink BC Emergency iDoctor-in-assistance (HEiDi) virtual physician advice and subsequent health service utilization for callers to a nurse-managed provincial health information telephone service.

BACKGROUND: British Columbia 8-1-1 callers who are advised by a nurse to seek urgent medical care can be referred to virtual physicians (VPs) for supplemental assessment and advice. Prior research indicates callers' subsequent health service use may diverge from VP advice. We sought to 1) estimate concordance between VP advice and subsequent health service use, and 2) identify factors associated with concordance to understand potential drivers of discordant cases. METHODS: We linked relevant provincial administrative databases to obtain inpatient, outpatient, and emergency service use by callers. We developed operational definitions of concordance collaboratively with researcher, patient, VP, and management perspectives. We used Kaplan-Meier curves to describe health service use post-VP consultation and Cox regression to estimate the association of caller factors (rurality, demography, attachment to primary care) and call factors (reason, triage level, time of day) with concordance as hazard ratios. RESULTS: We analyzed 17,188 calls from November 16, 2020 to April 30, 2021. Callers advised to attend an emergency department (ED) immediately were the most concordant (73%) while concordance was lowest for those advised to seek Family Physician (FP) care either immediately (41%) or within 7 days (47%). Callers unattached to FPs were less likely to schedule an FP visit (hazard ratio = 0.76 [95%CI: 0.68-0.85]). Rural callers were less likely to attend an ED within 48 h when advised to go immediately (0.53 [95%CI:0.46-0.61]) compared to urban callers. Rural callers advised to see an FP, either immediately (1.28 [95%CI:1.01-1.62]) or within 7 days (1.23 [95%CI: 1.11-1.37]), were more likely to do so than urban callers. INTERPRETATION: Concordance between VP advice and subsequent caller health service use varies substantially by category of advice and caller rurality. Concordance with advice to "Go to ED" is high overall but to access primary care is below 50%, suggesting potential issues with timely access to FP care. Future research from a patient/caller centered perspective may reveal additional barriers and facilitators to concordance.

Uninformed Origins: Should We Be Advising Parents on the Source of Medicines and Therapies?

Respecting patient autonomy through the process of soliciting informed consent is a cornerstone of clinical ethics. In pediatrics, until a child becomes an adult or legally emancipated, that ethical tenet takes the form of respect for parental decision-making authority. In instances of respecting religious beliefs, doing so is not always apparent and sometimes the challenge lies not only in the healthcare provider's familiarity of religious restrictions but also their knowledge of medical interventions themselves which might conflict with those restrictions. We examine a case of a newborn receiving animal-derived surfactant, a common scenario in neonatology, and present considerations for providers to weigh when confronting when such an intervention might conflict with parent's religious beliefs. We end with strategizing ways to address this issue as a medical community.

Clinical and Economic Outcomes in Patients With Metastatic Urothelial Carcinoma Receiving First-Line Systemic Treatment (the IMPACT UC I Study).

BACKGROUND: The IMPACT UC I study assessed real-world treatment patterns, outcomes, healthcare resource utilization (HCRU), and costs in patients with metastatic urothelial carcinoma (mUC) receiving first-line (1L) systemic treatment after the FDA approval of 1L immune checkpoint inhibitor (ICI) monotherapy. PATIENTS AND METHODS: This retrospective study used 100% Medicare fee-for-service claims from 1/1/2015 to 6/30/2019 to identify patients aged ≥18 years diagnosed with UC with evidence of metastatic disease, continuously enrolled for 6 months before and after initial diagnosis. Patients were grouped by 1L treatment: cisplatin-containing chemotherapy, carboplatin-containing chemotherapy, ICI monotherapy, or nonplatinum-containing therapy. Unadjusted time on 1L treatment (TOT), overall survival (OS), HCRU, and total healthcare costs were analyzed. RESULTS: Of 18 888 patients with mUC, 8630 (45.7%) had received identified 1L systemic treatment; platinum-containing chemotherapy was the most common (cisplatin-containing chemotherapy, 37.6%; carboplatin-containing chemotherapy, 30.2%). Cisplatin- and carboplatin-containing chemotherapy had the shortest time-to-treatment initiation (median, 1.7-3.0 months) and longest TOT (median, 4.0-4.3 months). Median OS was longest with cisplatin-containing chemotherapy (20.0 months) and shortest with ICI monotherapy (7.6 months). Cisplatin- and carboplatin-containing chemotherapy were associated with highest HCRU; total healthcare costs were approximately 2-fold higher with ICI monotherapy vs other 1L treatments ($10 359 vs $5042-$5709 per patient per month). CONCLUSION: 1L platinum-containing chemotherapy resulted in the longest median OS and highest HCRU, whereas 1L ICI treatment had the shortest median OS and the highest costs. Over 50% of patients diagnosed with advanced UC (aUC) received no systemic therapy, highlighting the importance of optimal 1L treatment decisions in aUC.

Association between toxic drug events and encephalopathy in British Columbia, Canada: a cross-sectional analysis.

BACKGROUND: Encephalopathy can occur from a non-fatal toxic drug event (overdose) which results in a partial or complete loss of oxygen to the brain, or due to long-term substance use issues. It can be categorized as a non-traumatic acquired brain injury or toxic encephalopathy. In the context of the drug toxicity crisis in British Columbia (BC), Canada, measuring the co-occurrence of encephalopathy and drug toxicity is challenging due to lack of standardized screening. We aimed to estimate the prevalence of encephalopathy among people who experienced a toxic drug event and examine the association between toxic drug events and encephalopathy. METHODS: Using a 20% random sample of BC residents from administrative health data, we conducted a cross-sectional analysis. Toxic drug events were identified using the BC Provincial Overdose Cohort definition and encephalopathy was identified using ICD codes from hospitalization, emergency department, and primary care records between January 1st 2015 and December 31st 2019. Unadjusted and adjusted log-binomial regression models were employed to estimate the risk of encephalopathy among people who had a toxic drug event compared to people who did not experience a toxic drug event. RESULTS: Among people with encephalopathy, 14.6% (n = 54) had one or more drug toxicity events between 2015 and 2019. After adjusting for sex, age, and mental illness, people who experienced drug toxicity were 15.3 times (95% CI = 11.3, 20.7) more likely to have encephalopathy compared to people who did not experience a drug toxicity event. People who were 40 years and older, male, and had a mental illness were at increased risk of encephalopathy. CONCLUSIONS: There is a need for collaboration between community members, health care providers, and key stakeholders to develop a standardized approach to define, screen, and detect neurocognitive injury related to drug toxicity.

Haplotype-based analysis resolves missing heritability in oculocutaneous albinism type 1B.

Oculocutaneous albinism (OCA) is a rare disorder of pigment production. Affected individuals have variably decreased global pigmentation and visual-developmental changes that lead to low vision. OCA is notable for significant missing heritability, particularly among individuals with residual pigmentation. Tyrosinase (TYR) is the rate-limiting enzyme in melanin pigment biosynthesis and mutations that decrease enzyme function are one of the most common causes of OCA. We present the analysis of high-depth short-read TYR sequencing data for a cohort of 352 OCA probands, ∼50% of whom were previously sequenced without yielding a definitive diagnostic result. Our analysis identified 66 TYR single-nucleotide variants (SNVs) and small insertion/deletions (indels), 3 structural variants, and a rare haplotype comprised of two common frequency variants (p.Ser192Tyr and p.Arg402Gln) in cis-orientation, present in 149/352 OCA probands. We further describe a detailed analysis of the disease-causing haplotype, p.[Ser192Tyr; Arg402Gln] ("cis-YQ"). Haplotype analysis suggests that the cis-YQ allele arose by recombination and that multiple cis-YQ haplotypes are segregating in OCA-affected individuals and control populations. The cis-YQ allele is the most common disease-causing allele in our cohort, representing 19.1% (57/298) of TYR pathogenic alleles in individuals with type 1 (TYR-associated) OCA. Finally, among the 66 TYR variants, we found several additional alleles defined by a cis-oriented combination of minor, potentially hypomorph-producing alleles at common variant sites plus a second, rare pathogenic variant. Together, these results suggest that identification of phased variants for the full TYR locus are required for an exhaustive assessment for potentially disease-causing alleles.

Health system use and outcomes of urgently triaged callers to a nurse-managed telephone service for provincial health information after initiation of supplemental virtual physician assessment: a descriptive study.

BACKGROUND: British Columbia's 8-1-1 telephone service connects callers with nurses for health care advice. As of Nov. 16, 2020, callers advised by a registered nurse to obtain in-person medical care can be subsequently referred to virtual physicians. We sought to determine health system use and outcomes of 8-1-1 callers urgently triaged by a nurse and subsequently assessed by a virtual physician. METHODS: We identified callers referred to a virtual physician between Nov. 16, 2020, and Apr. 30, 2021. After assessment, virtual physicians assigned callers to 1 of 5 triage dispositions (i.e., go to emergency department [ED] now, see primary care provider within 24 hours, schedule an appointment with a health care provider, try home treatment, other). We linked relevant administrative databases to ascertain subsequent health care use and outcomes. RESULTS: We identified 5937 encounters with virtual physicians involving 5886 8-1-1 callers. Virtual physicians advised 1546 callers (26.0%) to go to the ED immediately, of whom 971 (62.8%) had 1 or more ED visits within 24 hours. Virtual physicians advised 556 (9.4%) callers to seek primary care within 24 hours, of whom 132 (23.7%) had primary care billings within 24 hours. Virtual physicians advised 1773 (29.9%) callers to schedule an appointment with a health care provider, of whom 812 (45.8%) had primary care billings within 7 days. Virtual physicians advised 1834 (30.9%) callers to try a home treatment, of whom 892 (48.6%) had no health system encounters over the next 7 days. Eight (0.1%) callers died within 7 days of assessment with a virtual physician, 5 of whom were advised to go to the ED immediately. Fifty-four (2.9%) callers with a "try home treatment" disposition were admitted to hospital within 7 days of a virtual physician assessment, and no callers who were advised home treatment died. INTERPRETATION: This Canadian study evaluated health service use and outcomes arising from the addition of virtual physicians to a provincial health information telephone service. Our findings suggest that supplementation of this service with an assessment from a virtual physician safely reduces the overall proportion of callers advised to seek urgent in-person visits.

Differential Regulation of Retinoic Acid Metabolism in Fanconi Anemia.

Fanconi anemia (FA) is a rare genetic disease characterized by heterogeneous congenital abnormalities and increased risk for bone marrow failure and cancer. FA is caused by mutation of any one of 23 genes, the protein products of which function primarily in the maintenance of genome stability. An important role for the FA proteins in the repair of DNA interstrand crosslinks (ICLs) has been established in vitro . While the endogenous sources of ICLs relevant to the pathophysiology of FA have yet to be clearly determined, a role for the FA proteins in a two-tier system for the detoxification of reactive metabolic aldehydes has been established. To discover new metabolic pathways linked to FA, we performed RNA-seq analysis on non-transformed FA-D2 ( FANCD2 -/- ) and FANCD2-complemented patient cells. Multiple genes associated with retinoic acid metabolism and signaling were differentially expressed in FA-D2 ( FANCD2 -/- ) patient cells, including ALDH1A1 and RDH10 , which encode for retinaldehyde and retinol dehydrogenases, respectively. Increased levels of the ALDH1A1 and RDH10 proteins was confirmed by immunoblotting. FA-D2 ( FANCD2 -/- ) patient cells displayed increased aldehyde dehydrogenase activity compared to the FANCD2-complemented cells. Upon exposure to retinaldehyde, FA-D2 ( FANCD2 -/- ) cells exhibited increased DNA double-strand breaks and checkpoint activation indicative of a defect in the repair of retinaldehyde-induced DNA damage. Our findings describe a novel link between retinoic acid metabolism and FA and identify retinaldehyde as an additional reactive metabolic aldehyde relevant to the pathophysiology of FA.

Whole Blood Resuscitation and Association with Survival in Injured Patients with an Elevated Probability of Mortality.

BACKGROUND: Low-titer group O whole blood (LTOWB) resuscitation is becoming common in both military and civilian settings and may represent the ideal resuscitation intervention. We sought to characterize the safety and efficacy of LTOWB resuscitation relative to blood component resuscitation. STUDY DESIGN: A prospective, multicenter, observational cohort study was performed using 7 trauma centers. Injured patients at risk of massive transfusion who required both blood transfusion and hemorrhage control procedures were enrolled. The primary outcome was 4-hour mortality. Secondary outcomes included 24-hour and 28-day mortality, achievement of hemostasis, death from exsanguination, and the incidence of unexpected survivors. RESULTS: A total of 1,051 patients in hemorrhagic shock met all enrollment criteria. The cohort was severely injured with >70% of patients requiring massive transfusion. After propensity adjustment, no significant 4-hour mortality difference across LTOWB and component patients was found (relative risk [RR] 0.90, 95% CI 0.59 to 1.39, p = 0.64). Similarly, no adjusted mortality differences were demonstrated at 24 hours or 28 days for the enrolled cohort. When patients with an elevated prehospital probability of mortality were analyzed, LTOWB resuscitation was independently associated with a 48% lower risk of 4-hour mortality (relative risk [RR] 0.52, 95% CI 0.32 to 0.87, p = 0.01) and a 30% lower risk of 28-day mortality (RR 0.70, 95% CI 0.51 to 0.96, p = 0.03). CONCLUSIONS: Early LTOWB resuscitation is safe but not independently associated with survival for the overall enrolled population. When patients were selected with an elevated probability of mortality based on prehospital injury characteristics, LTOWB was independently associated with a lower risk of mortality starting at 4 hours after arrival through 28 days after injury.

Qualitative Exploration of Emergency Department Care Experiences Among People With Opioid Use Disorder.

STUDY OBJECTIVE: We described the experiences and preferences of people with opioid use disorder who access emergency department (ED) services regarding ED care and ED-based interventions. METHODS: Between June and September 2020, we conducted phone or in-person semistructured qualitative interviews with patients recently discharged from 2 urban EDs in Vancouver, BC, Canada, to explore experiences and preferences of ED care and ED-based opioid use disorder interventions. We recruited participants from a cohort of adults with opioid use disorder who were participating in an ED-initiated outreach program. We transcribed audio recordings verbatim. We iteratively developed a thematic coding structure, with interim analyses to assess for thematic saturation. Two team members with lived experience of opioid use provided feedback on content, wording, and analysis throughout the study. RESULTS: We interviewed 19 participants. Participants felt discriminated against for their drug use, which led to poorer perceived health care and downstream ED avoidance. Participants desired to be treated like ED patients who do not use drugs and to be more involved in their ED care. Participants nevertheless felt comfortable discussing their substance use with ED staff and valued continuous ED operating hours. Regarding opioid use disorder treatment, participants supported ED-based buprenorphine/naloxone programs but also suggested additional options (eg, different initiation regimens and settings and other opioid agonist therapies) to facilitate further treatment uptake. CONCLUSION: Based on participant experiences, we recommend addressing potentially stigmatizing practices, increasing patient involvement in their care during ED visits, and increasing access to various opioid use disorder-related treatments and community support.

Optimal Prehospital Crystalloid Resuscitation Volume in Trauma Patients at Risk for Hemorrhagic Shock.

BACKGROUND: Prehospital resuscitation guidelines vary widely, and blood products, although likely superior, are not available for most patients in the prehospital setting. Our objective was to determine the prehospital crystalloid volume associated with the lowest mortality among patients in hemorrhagic shock. STUDY DESIGN: This is a secondary analysis of the Prehospital Air Medical Plasma trial. Injured patients from the scene with hypotension and tachycardia or severe hypotension were included. Segmented regression and generalized additive models were used to evaluate nonlinear effects of prehospital crystalloid volume on 24-hour mortality. Logistic regression evaluated the association between risk-adjusted mortality and prehospital crystalloid volume ranges to identify optimal target volumes. Inverse propensity weighting was performed to account for patient heterogeneity. RESULTS: There were 405 patients included. Segmented regression suggested the nadir of 24-hour mortality lay within 377 to 1,419 mL prehospital crystalloid. Generalized additive models suggested the nadir of 24-hour mortality lay within 242 to 1,333 mL prehospital crystalloid. A clinically operationalized range of 250 to 1,250 mL was selected based on these findings. Odds of 24-hour mortality were higher for patients receiving less than 250 mL (adjusted odds ratio [aOR] 2.46; 95% CI 1.31 to 4.83; p = 0.007) and greater than 1,250 mL (aOR 2.57; 95% CI 1.24 to 5.45; p = 0.012) compared with 250 to 1,250 mL. Propensity-weighted regression similarly demonstrated odds of 24-hour mortality were higher for patients receiving less than 250 mL (aOR 2.62; 95% CI 1.34 to 5.12; p = 0.005) and greater than 1,250 mL (aOR 2.93; 95% CI 1.36 to 6.29; p = 0.006) compared with 250 to 1,250 mL. CONCLUSIONS: Prehospital crystalloid volumes between 250 and 1,250 mL are associated with lower mortality compared with lower or higher volumes. Further work to validate these finding may provide practical volume targets for prehospital crystalloid resuscitation.