The chromosome-scale genome assembly for the West Nile vector Culex quinquefasciatus uncovers patterns of genome evolution in mosquitoes

BACKGROUND

Understanding genome organization and evolution is important for species involved in transmission of human diseases, such as mosquitoes. Anophelinae and Culicinae subfamilies of mosquitoes show striking differences in genome sizes, sex chromosome arrangements, behavior, and ability to transmit pathogens. However, the genomic basis of these differences is not fully understood.

METHODS

In this study, we used a combination of advanced genome technologies such as Oxford Nanopore Technology sequencing, Hi-C scaffolding, Bionano, and cytogenetic mapping to develop an improved chromosome-scale genome assembly for the West Nile vector Culex quinquefasciatus.

RESULTS

We then used this assembly to annotate odorant receptors, odorant binding proteins, and transposable elements. A genomic region containing male-specific sequences on chromosome 1 and a polymorphic inversion on chromosome 3 were identified in the Cx. quinquefasciatus genome. In addition, the genome of Cx. quinquefasciatus was compared with the genomes of other mosquitoes such as malaria vectors An. coluzzi and An. albimanus, and the vector of arboviruses Ae. aegypti. Our work confirms significant expansion of the two chemosensory gene families in Cx. quinquefasciatus, as well as a significant increase and relocation of the transposable elements in both Cx. quinquefasciatus and Ae. aegypti relative to the Anophelines. Phylogenetic analysis clarifies the divergence time between the mosquito species. Our study provides new insights into chromosomal evolution in mosquitoes and finds that the X chromosome of Anophelinae and the sex-determining chromosome 1 of Culicinae have a significantly higher rate of evolution than autosomes.

CONCLUSION

The improved Cx. quinquefasciatus genome assembly uncovered new details of mosquito genome evolution and has the potential to speed up the development of novel vector control strategies.

Tyrosine transfer RNA levels and modifications during blood-feeding and vitellogenesis in the mosquito, Aedes aegypti

Mosquitoes such as Aedes aegypti must consume a blood meal for the nutrients necessary for egg production. Several transcriptome and proteome changes occur post blood meal that likely corresponds with codon usage alterations. Transfer RNA (tRNA) is the adapter molecule that reads messenger RNA (mRNA) codons to add the appropriate amino acid during protein synthesis. Chemical modifications to tRNA enhance codons' decoding, improving the accuracy and efficiency of protein synthesis. Here, we examined tRNA modifications and transcripts associated with the blood meal and subsequent periods of vitellogenesis in A. aegypti. More specifically, we assessed tRNA transcript abundance and modification levels in the fat body at critical times post blood-feeding. Based on a combination of alternative codon usage and identification of particular modifications, we identified that increased transcription of tyrosine tRNAs is likely critical during the synthesis of egg yolk proteins in the fat body following a blood meal. Altogether, changes in both the abundance and modification of tRNA are essential factors in the process of vitellogenin production after blood-feeding in mosquitoes.

Success of Liquid Tumor Biopsy in Men with Metastatic Prostate Cancer According to Self-Identified Race

PURPOSE/OBJECTIVE(S)

Liquid biopsy using cell-free DNA (cfDNA) is increasingly used to identify somatic prostate cancer (PrCa) alterations when tissue biopsy of a metastatic lesion is infeasible or impractical. High-risk somatic alterations identified by cfDNA have been recently shown to predict the benefit of metastasis-directed therapy with stereotactic body radiation therapy in PrCa. However, given the older age of PrCa patients, liquid biopsy is often contaminated with alterations related to clonal hematopoiesis of indeterminate potential (CHIP), generating uncertainty in the clinical utility of the results. Given the higher incidence and aggressiveness of metastatic PrCa in Black men, we sought to determine if the success of cfDNA testing varied by race in a large and diverse cohort of United States Veterans with metastatic PrCa, hypothesizing that race would not influence the success of cfDNA testing.

MATERIALS/METHODS

Veterans with metastatic PrCa underwent next-generation sequencing of cfDNA biopsy specimens through the VA National Precision Oncology Program from February 2019 to November 2022. Successful identification of PrCa with cfDNA testing was defined as the identification of an alteration in one or more PrCa-related related genes in the gene panel tested (AR, CDK12, SPOP, MED12, CCND1, BRAF, AKT1, TMPRSS2, ERG, ETV1, and ETV4). Univariate logistic regression was employed to explore the association between patient self-identified race, as well as other patient and disease-specific factors at the time of cfDNA biopsy, with the likelihood of yielding a successful cfDNA biopsy result.

RESULTS

A total of 2066 cfDNA tests from 1985 Veterans were related to a diagnosis of PrCa, passed quality control measures, and were linkable to patient-level demographics. Median age at testing was 74, median PSA at testing was 22.7, median PSA doubling time (PSADT) was 3.6 months, and median Gleason score was 8. 57% of Veterans self-identified as White, 33% as Black, and 10% as Other. Eight hundred fourteen (39%) tests were deemed successful by finding a PrCa related gene alteration. Among successful tests, the most frequently encountered alterations were AR alterations in 60.4% White men and 33.9% Black men (p = 0.72), followed by TMPRSS2 alterations in 70.3% White men and 22.0% Black men (p<0.001). Despite a lower rate of PrCa-specific alterations in Black men, on univariate analysis, Veteran self-identified race was not associated with successful cfDNA testing (OR 0.95, 95% CI 0.78-1.14, p = 0.6), whereas PSA in quintiles 2-4, PSADT <12 months, and unit increase in Gleason score were associated with successful cfDNA testing (p<0.01 for all).

CONCLUSION

Successful cfDNA biopsy in metastatic PrCa is associated with PSA and PSADT, but not related to patient self-identified race. In appropriate clinical scenarios, patients who self-identify as Black or White are equally likely to have PrCa-specific alterations detected on cfDNA testing when evaluating metastatic PrCa patients for local and systemic therapies.

Aging and Alzheimer's disease have dissociable effects on local and regional medial temporal lobe connectivity

Functional disruption of the medial temporal lobe-dependent networks is thought to underlie episodic memory deficits in aging and Alzheimer's disease. Previous studies revealed that the anterior medial temporal lobe is more vulnerable to pathological and neurodegenerative processes in Alzheimer's disease. In contrast, cognitive and structural imaging literature indicates posterior, as opposed to anterior, medial temporal lobe vulnerability in normal aging. However, the extent to which Alzheimer's and aging-related pathological processes relate to functional disruption of the medial temporal lobe-dependent brain networks is poorly understood. To address this knowledge gap, we examined functional connectivity alterations in the medial temporal lobe and its immediate functional neighbourhood-the Anterior-Temporal and Posterior-Medial brain networks-in normal agers, individuals with preclinical Alzheimer's disease and patients with Mild Cognitive Impairment or mild dementia due to Alzheimer's disease. In the Anterior-Temporal network and in the perirhinal cortex, in particular, we observed an inverted 'U-shaped' relationship between functional connectivity and Alzheimer's stage. According to our results, the preclinical phase of Alzheimer's disease is characterized by increased functional connectivity between the perirhinal cortex and other regions of the medial temporal lobe, as well as between the anterior medial temporal lobe and its one-hop neighbours in the Anterior-Temporal system. This effect is no longer present in symptomatic Alzheimer's disease. Instead, patients with symptomatic Alzheimer's disease displayed reduced hippocampal connectivity within the medial temporal lobe as well as hypoconnectivity within the Posterior-Medial system. For normal aging, our results led to three main conclusions: (i) intra-network connectivity of both the Anterior-Temporal and Posterior-Medial networks declines with age; (ii) the anterior and posterior segments of the medial temporal lobe become increasingly decoupled from each other with advancing age; and (iii) the posterior subregions of the medial temporal lobe, especially the parahippocampal cortex, are more vulnerable to age-associated loss of function than their anterior counterparts. Together, the current results highlight evolving medial temporal lobe dysfunction in Alzheimer's disease and indicate different neurobiological mechanisms of the medial temporal lobe network disruption in aging versus Alzheimer's disease.

Reduced male fertility of an Antarctic mite following extreme heat stress could prompt localized population declines

Climate change is leading to substantial global thermal changes, which are particularly pronounced in polar regions. Therefore, it is important to examine the impact of heat stress on the reproduction of polar terrestrial arthropods, specifically, how brief extreme events may alter survival. We observed that sublethal heat stress reduces male fecundity in an Antarctic mite, yielding females that produced fewer viable eggs. Females and males collected from microhabitats with high temperatures showed a similar reduction in fertility. This impact is temporary, as indicated by recovery of male fecundity following return to cooler, stable conditions. The diminished fecundity is likely due to a drastic reduction in the expression of male-associated factors that occur in tandem with a substantial increase in the expression of heat shock proteins. Cross-mating between mites from different sites confirmed that heat-exposed populations have impaired male fertility. However, the negative impacts are transient as the effect on fertility declines with recovery time under less stressful conditions. Modeling indicated that heat stress is likely to reduce population growth and that short bouts of non-lethal heat stress could have substantial reproductive effects on local populations of Antarctic arthropods.

Additive Effects of Cyclic Peptide [R4W4] When Added Alongside Azithromycin and Rifampicin against Mycobacterium avium Infection

Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) counts were assessed after treating M. avium cultures with varying concentrations of cyclic [R4W4] alone or in conjunction with azithromycin or rifampicin 3 h and 4 days post-treatment. M. avium growth was significantly reduced 4 days after cyclic [R4W4] single treatment. Additionally, cyclic [R4W4]-azithromycin and cyclic [R4W4]-rifampicin combination treatments at specific concentrations significantly reduced M. avium survival 3 h and 4 days post-treatment compared with single antibiotic treatment alone. These findings demonstrate cyclic [R4W4] as a potent treatment method against M. avium and provide insight into novel therapeutic approaches against mycobacterium infections.

Effectors of anterior morphogenesis in C. elegans embryos

During embryogenesis the nascent Caenorhabditis elegans epidermis secretes an apical extracellular matrix (aECM) that serves as an external stabilizer, preventing deformation of the epidermis by mechanical forces exerted during morphogenesis. At present, the factors that contribute to aECM function are mostly unknown, including the aECM components themselves, their posttranslational regulators, and the pathways required for their secretion. Here we showed that two proteins previously linked to aECM function, SYM-3/FAM102A and SYM-4/WDR44, colocalize to intracellular and membrane-associated puncta and likely function in a complex. Proteomics experiments also suggested potential roles for SYM-3/FAM102A and SYM-4/WDR44 family proteins in intracellular trafficking. Nonetheless, we found no evidence to support a critical function for SYM-3 or SYM-4 in the apical deposition of two aECM components, NOAH-1 and FBN-1. Moreover, loss of a key splicing regulator of fbn-1, MEC-8/RBPMS2, had surprisingly little effect on the abundance or deposition of FBN-1. Using a focused screening approach, we identified 32 additional proteins that likely contribute to the structure and function of the embryonic aECM. We also characterized morphogenesis defects in embryos lacking mir-51 microRNA family members, which display a similar phenotype to mec-8; sym double mutants. Collectively, these findings add to our knowledge of factors controlling embryonic morphogenesis.

Liposomal Glutathione Supplementation Mitigates Extrapulmonary Tuberculosis in the Liver and Spleen

BACKGROUND

Extrapulmonary tuberculosis (EPTB) accounts for a fifth of all Mycobacterium tuberculosis (M. tb) infections worldwide. The rise of multidrug resistance in M. tb alongside the hepatotoxicity associated with antibiotics presents challenges in managing and treating tuberculosis (TB), thereby prompting a need for new therapeutic approaches. Administration of liposomal glutathione (L-GSH) has previously been shown to lower oxidative stress, enhance a granulomatous response, and reduce the burden of M. tb in the lungs of M. tb-infected mice. However, the effects of L-GSH supplementation during active EPTB in the liver and spleen have yet to be explored.

METHODS

In this study, we evaluated hepatic glutathione (GSH) and malondialdehyde (MDA) levels, and the cytokine profiles of untreated and L-GSH-treated M. tb-infected wild type (WT) mice. Additionally, the hepatic and splenic M. tb burdens and tissue pathologies were also assessed.

RESULTS

L-GSH supplementation increased total hepatic levels and reduced GSH. A decrease in the levels of MDA, oxidized GSH, and interleukin (IL)-6 was also detected following L-GSH treatment. Furthermore, L-GSH supplementation was observed to increase interferon-gamma (IFN-γ) and tumor necrosis factor (TNF)-α production and decrease IL-10 levels. M. tb survival was significantly reduced in the liver and spleen following L-GSH supplementation. L-GSH treatment also provided a host-protective effect in the liver and spleen of M. tb-infected mice.

CONCLUSIONS

Overall, L-GSH supplementation elevated the levels of total and reduced forms of GSH in the liver and reduced the burden of M. tb by decreasing oxidative stress, enhancing the production of immunosupportive cytokines, and reducing the levels of immunosuppressive cytokines. These observed benefits highlight the potential of L-GSH supplementation during active EPTB and provide insight into novel therapeutic interventions against M. tb infections.

Topical Absorption of Glutathione-Cyclodextrin Nanoparticle Complex in Healthy Human Subjects Improves Immune Response against Mycobacterium avium Infection

Glutathione (GSH) is an important intracellular antioxidant responsible for neutralizing reactive oxygen species (ROS). Our laboratory previously demonstrated that the oral administration of liposomal GSH improves immune function against mycobacterium infections in healthy patients along with patients with HIV and Type 2 diabetes. We aim to determine if the topical application of a glutathione-cyclodextrin nanoparticle complex (GSH-CD) confers a therapeutic effect against mycobacterium infections. In our study, healthy participants received either topical GSH-CD (n = 15) or placebo (n = 15) treatment. Subjects were sprayed four times twice a day for three days topically on the abdomen. Blood draws were collected prior to application, and at 1, 4, and 72 h post-initial topical application. GSH, malondialdehyde (MDA), and cytokine levels were assessed in the processed blood samples of study participants. Additionally, whole blood cultures from study participants were challenged with Mycobacterium avium (M. avium) infection in vitro to assess mycobacterium survival post-treatment. Topical GSH-CD treatment was observed to elevate GSH levels in peripheral blood mononuclear cells (PBMCs) and red blood cells and decrease MDA levels in PBMCs 72 h post-treatment. An increase in plasma IL-2, IFN-γ, IL-12p70, and TNF-α was observed at 72 h post-topical GSH-CD treatment. Enhanced mycobacterium clearance was observed at 4 h and 72 h post-topical GSH-CD treatment. Overall, topical GSH-CD treatment was associated with improved immune function against M. avium infection. The findings of this pilot study suggest GSH-cyclodextrin complex formulation can be used topically as a safe alternative mode of GSH delivery in the peripheral blood.

Glutathione Modulates Efficacious Changes in the Immune Response against Tuberculosis

Glutathione (GSH) is an antioxidant in human cells that is utilized to prevent damage occurred by reactive oxygen species, free radicals, peroxides, lipid peroxides, and heavy metals. Due to its immunological role in tuberculosis (TB), GSH is hypothesized to play an important part in the immune response against M. tb infection. In fact, one of the hallmark structures of TB is granuloma formation, which involves many types of immune cells. T cells, specifically, are a major component and are involved in the release of cytokines and activation of macrophages. GSH also serves an important function in macrophages, natural killer cells, and T cells in modulating their activation, their metabolism, proper cytokine release, proper redox activity, and free radical levels. For patients with increased susceptibility, such as those with HIV and type 2 diabetes, the demand for higher GSH levels is increased. GSH acts as an important immunomodulatory antioxidant by stabilizing redox activity, shifting of cytokine profile toward Th1 type response, and enhancing T lymphocytes. This review compiles reports showing the benefits of GSH in improving the immune responses against M. tb infection and the use of GSH as an adjunctive therapy for TB.

Pathways that affect anterior morphogenesis in C. elegans embryos

During embryogenesis the nascent Caenorhabditis elegans epidermis secretes an apical extracellular matrix (aECM) that serves as an external stabilizer, preventing deformation of the epidermis by mechanical forces exerted during morphogenesis. We showed that two conserved proteins linked to this process, SYM-3/FAM102A and SYM-4/WDR44, colocalize to intracellular and membrane-associated puncta and likely function together in a complex. Proteomics data also suggested potential roles for FAM102A and WDR44 family proteins in intracellular trafficking, consistent with their localization patterns. Nonetheless, we found no evidence to support a clear function for SYM-3 or SYM-4 in the apical deposition of two aECM components, FBN-1 and NOAH. Surprisingly, loss of MEC-8/RBPMS2, a conserved splicing factor and regulator of fbn-1 , had little effect on the abundance or deposition of FBN-1 to the aECM. Using a focused screening approach, we identified 32 additional proteins that likely contribute to the structure and function of the embryonic aECM. Lastly, we examined morphogenesis defects in embryos lacking mir-51 microRNA family members, which display a related embryonic phenotype to mec-8; sym double mutants. Collectively, our findings add to our knowledge of pathways controlling embryonic morphogenesis.

SUMMARY STATEMENT

We identify new proteins in apical ECM biology in C. elegans and provide evidence that SYM-3/FAM102A and SYM-4/WDR44 function together in trafficking but do not regulate apical ECM protein deposition.

Aging and Alzheimer's Disease Have Dissociable Effects on Medial Temporal Lobe Connectivity

Functional disruption of the medial temporal lobe-dependent networks is thought to underlie episodic memory deficits in aging and Alzheimer's disease. Previous studies revealed that the anterior medial temporal lobe is more vulnerable to pathological and neurodegenerative processes in Alzheimer's disease. In contrast, cognitive and structural imaging literature indicates posterior, as opposed to anterior, medial temporal lobe vulnerability in normal aging. However, the extent to which Alzheimer's and aging-related pathological processes relate to functional disruption of the medial temporal lobe-dependent brain networks is poorly understood. To address this knowledge gap, we examined functional connectivity alterations in the medial temporal lobe and its immediate functional neighborhood - the Anterior-Temporal and Posterior-Medial brain networks - in normal agers, individuals with preclinical Alzheimer's disease, and patients with Mild Cognitive Impairment or mild dementia due to Alzheimer's disease. In the Anterior-Temporal network and in the perirhinal cortex, in particular, we observed an inverted 'U-shaped' relationship between functional connectivity and Alzheimer's stage. According to our results, the preclinical phase of Alzheimer's disease is characterized by increased functional connectivity between the perirhinal cortex and other regions of the medial temporal lobe, as well as between the anterior medial temporal lobe and its one-hop neighbors in the Anterior-Temporal system. This effect is no longer present in symptomatic Alzheimer's disease. Instead, patients with symptomatic Alzheimer's disease displayed reduced hippocampal connectivity within the medial temporal lobe as well as hypoconnectivity within the Posterior-Medial system. For normal aging, our results led to three main conclusions: (1) intra-network connectivity of both the Anterior-Temporal and Posterior-Medial networks declines with age; (2) the anterior and posterior segments of the medial temporal lobe become increasingly decoupled from each other with advancing age; and, (3) the posterior subregions of the medial temporal lobe, especially the parahippocampal cortex, are more vulnerable to age-associated loss of function than their anterior counterparts. Together, the current results highlight evolving medial temporal lobe dysfunction in Alzheimer's disease and indicate different neurobiological mechanisms of the medial temporal lobe network disruption in aging vs. Alzheimer's disease.

A simple setup for in situ alkali metal electronic spin polarimetry

Faraday rotation is considered a gold standard measurement of the electronic spin polarization of an alkali metal vapor produced under optical pumping. However, during the production of large volumes of hyperpolarized xenon gas, transmission monitoring measurements, otherwise known as field cycling measurements, are generally employed to measure the spin polarization of alkali metal atoms in situ as this method is easier to implement than Faraday rotation on standard polarizer setups. Here, we present a simple, low-cost experimental setup to perform Faraday rotation measurements of the electronic spin polarization of alkali metal atoms that can be easily implemented on standard polarizer setups. We then compare Rb polarization measurements obtained with the Faraday rotation method to those obtained with the transmission monitoring method. To our knowledge, a direct comparison of these methods has never been made. Overall, we found good agreement between the two methods, but at low Rb density and high laser power, we found evidence of nonlinear magneto-optical effects that may prevent Faraday rotation from being used under these conditions.

Abundances of transfer RNA modifications and transcriptional levels of tRNA-modifying enzymes are sex-associated in mosquitoes

As carriers of multiple human diseases, understanding the mechanisms behind mosquito reproduction may have implications for remediation strategies. Transfer RNA (tRNA) acts as the adapter molecule of amino acids and are key components in protein synthesis. A critical factor in the function of tRNAs is chemical modifications which contribute to codon-anticodon interactions. Here, we provide an assessment of tRNA modifications between sexes for three mosquito species and examine the correlation of transcript levels underlying key proteins involved in tRNA modification. Thirty-three tRNA modifications were detected among mosquito species and most of these modifications are higher in females compared to males for three mosquito species. Analysis of previous male and female RNA-seq datasets indicated a similar increase in transcript levels of tRNA-modifying enzymes in females among six mosquito species, supporting our observed female enrichment of tRNA modifications. Tissues-specific expressional studies revealed higher transcript levels for tRNA-modifying enzymes in the ovaries for Aedes aegypti, but not male reproductive tissues. These studies suggest that tRNA modifications may be critical to reproduction in mosquitoes, representing a potential novel target for control through suppression of fecundity.

Ionizing radiation and chemical oxidant exposure impacts on Cryptococcus neoformans transfer RNAs

Cryptococcus neoformans is a fungus that is able to survive abnormally high levels of ionizing radiation (IR). The radiolysis of water by IR generates reactive oxygen species (ROS) such as H₂O₂ and OH^-. C. neoformans withstands the damage caused by IR and ROS through antioxidant production and enzyme-catalyzed breakdown of ROS. Given these particular cellular protein needs, questions arise whether transfer ribonucleic acids molecules (tRNAs) undergo unique chemical modifications to maintain their structure, stability, and/or function under such environmental conditions. Here, we investigated the effects of IR and H₂O₂ exposure on tRNAs in C. neoformans. We experimentally identified the modified nucleosides present in C. neoformans tRNAs and quantified changes in those modifications upon exposure to oxidative conditions. To better understand these modified nucleoside results, we also evaluated tRNA pool composition in response to the oxidative conditions. We found that regardless of environmental conditions, tRNA modifications and transcripts were minimally affected. A rationale for the stability of the tRNA pool and its concomitant profile of modified nucleosides is proposed based on the lack of codon bias throughout the C. neoformans genome and in particular for oxidative response transcripts. Our findings suggest that C. neoformans can rapidly adapt to oxidative environments as mRNA translation/protein synthesis are minimally impacted by codon bias.

A79 AIMING TO PROVIDE EARLIER CARE WHILE REDUCING SPECIALTY CLINIC WAIT TIMES: DEVELOPING A RELIABLE PROCESS OF ASSESSING THE ELIGIBILITY OF GASTROENTEROLOGY REFERRALS FOR PRIMARY CARE PATHWAYS

Background

Gastrointestinal (GI) diseases are common and are a source of substantial morbidity, mortality, and cost, accounting for the largest share of medical referrals from primary care physicians (PCPs) in Canada. Long wait times and increasing numbers of referrals for GI consultation have thus become a significant issue, and while awaiting consultation many patients experience impaired quality of life. Primary care clinical pathways are structured care plans outlining detailed steps for treating patients with specific GI conditions, supporting the translation of clinical guidelines into local protocols and clinical practice.

Aims

To identify the proportion of referrals sent from PCPs to the Queen’s Gastroenterology division that meet the eligibility criteria for a clinical care pathway.

Methods

A review was conducted to identify the proportion of non-urgent referrals in triage sent from PCPs to the Queen’s Gastroenterology division that met the criteria for a clinical care pathway from July 2019 to May 2020. The reason for referral from PCP to gastroenterology was recorded. Individual patient characteristics included in each referral letter were assessed, including age, sex, GI symptoms or signs, relevant clinical features (i.e. time course of symptoms, frequency of bowel movements), relevant laboratory parameters (i.e. CBC, LFTs, electrolytes) or any investigations ordered to evaluate the cause of the patient’s symptoms or signs by the PCP. Four reviewers assessed an initial sample of 200 referral letters and classified each patient’s eligibility for a primary care pathway (GERD, diarrhea, IBS, dyspepsia, or ineligible). After every 100 referrals, discrepancies were reviewed, and a consensus was reached for each case. Data from 100 subsequent referral letters were collected by two independent reviewers, and the inter-rater reliability was calculated. Following a high level of agreement, the final 70 referrals were assessed by two reviewers.

Results

Out of 370 referrals sent from PCPs to the Queen’s Gastroenterology division from July 2019 to December 2019, a total of 170 (46%) met the eligibility criteria for a clinical care pathway. From the eligible referrals, the proportion of patients in each pathway were as follows: 35% GERD, 12% diarrhea, 34% IBS and 19% dyspepsia. The inter-rater reliability for the first 100 referrals assessed by two independent reviewers was 94% (κ = 0.873).

Conclusions

These findings demonstrate that a significant proportion of the patient population referred from PCPs to Queen’s Gastroenterology would be eligible for a primary care pathway. Future steps include implementing these pathways to determine their effectiveness in reducing wait times and empowering PCPs to care for patients who do not require specialist referral.

Funding Agencies

None

Nb3Sn multicell cavity coating system at Jefferson Lab

Superconducting radio frequency niobium cavities are the building blocks of modern accelerators for scientific applications. Lower surface resistance, higher fields, and high operating temperatures advance the reach of the future accelerators for scientific discovery as well as potentially enabling cost-effective industrial solutions. We describe the design and performance of an Nb₃Sn coating system that converts the inner surface of niobium cavities to an Nb₃Sn film. The niobium surface, heated by radiation from the niobium retort, is exposed to Sn and SnCl₂ vapor during the heat cycle, which results in about 2 μm Nb₃Sn film on the niobium surface. Film composition and structure as well as radio frequency properties with 1-cell R&D cavities and 5-cell practical accelerator cavities are presented.

Effect of Different Fat Sources and Vitamin E Isoforms/Levels on Carcass Characteristics and Meat Quality of Pigs Grown to 150 Kg

ObjectivesThe objective was to evaluate the effect of supplementing α- and γ-tocopherol vitamin E isoforms with corn oil and tallow on carcass characteristics and meat quality of pigs grown to heavier weights (>150 kg).Materials and MethodsIndividually fed pigs (n = 72; 36 barrows, 36 gilts; 28.55 ± 1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were tallow and corn oil (5?). The vitamin E treatments included four levels of α-tocopheryl-acetate (ATA; 11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). Pigs were humanely slaughtered at approximately 150 kg. 45 min pH was taken at the 10th rib. After 24 h chill (4°C), carcass measurements were taken (carcass length, backfat depth at first rib, last rib, 10th rib and last lumbar, loin muscle area, and 24 h pH at the 10th rib). In addition, wholesale weights from the Boston butt (IMPS #406), shoulder picnic (IMPS #405), loin (IMPS #412), and belly (IMPS #408) and spareribs were recorded. Furthermore, bellies were divided into eight sections and the average depth was taken at each section and the vertical and lateral belly flex was measured. Drip loss was determined by suspending a 1.3cm chop at 4°C for 48 h and purge loss was determined from approximately 2kg vacuum packaged loin muscle sections at 0, 7, 14, and 30d. Objective (Hunter Lab Colorimeter XE Plus) and subjective (NPPC color, marbling and firmness scores) measurements were taken at the 10th rib. Data analysis were performed in SAS by least squares analysis of variance using the generalized linear model as a randomized complete block design. The individual pig served as the experimental unit and results were reported as least square means.ResultsThere were no differences in dressing percentage, 24 h pH, backfat depth, loin muscle area, primal cuts, purge loss, and drip loss between the two vitamin E isoforms. Fat treatments did not affect dressing percentage, 45 min and 24 h pH, backfat depth, loin muscle area, primal cuts, purge loss, drip loss as well as objective and subjective color. Although not significant (P = 0.07), pork from the γ-tocopherol pigs had a lower pH than the ATA treatment. The γ-tocopherol supplementation tended to have a lighter subjective color (P = 0.06) as well as increased L*, decreased a*, and increased the hue angle calculations at 7d shelf-life. The belly depth was greater (P = 0.01) along with higher lateral (P < 0.01) and a lower vertical (P < 0.01) flex for pigs fed tallow.ConclusionIn conclusion, feeding tallow to heavy weight pigs (150 kg) could improve belly firmness. Also, α-tocopherol did not improve shelf-life stability and γ-tocopherol could negatively affect subject and objective pork loin color.

Wait Time for Curative Intent Radio Frequency Ablation is Associated with Increased Mortality in Patients with Early Stage Hepatocellular Carcinoma

INTRODUCTION

Radiofrequency ablation (RFA) is a recommended curative intent treatment option for patients with early stage hepatocellular carcinoma (HCC). We investigated if wait times for RFA were associated with residual tumor, tumor recurrence, need for liver transplantation, or death.

MATERIAL AND METHODS

We conducted a retrospective study of patients diagnosed with HCC between January 2010 and December 2013 presenting to University Health Network (UHN) in Toronto, Canada. All patients receiving curative intent RFA for HCC were included. Multivariable Cox regression was used to determine if wait times were associated with clinical outcomes.

RESULTS

219 patients were included in the study. 72.6% were male and the median age was 62.7 years (IQR 55.6-71). Median tumor size at diagnosis was 21.5 mm (IQR 17-26); median MELD was 8.7 (IQR 7.2-11.4) and 57.1% were Barcelona stage 0. The cause of liver disease was viral hepatitis in 73.5% (Hepatitis B and C). The median time from HCC diagnosis to RFA treatment was 96 days (IQR 75-139). In multivariate analysis, wait time was not associated with requiring liver transplant or tumor recurrence, however, each incremental 30-day wait time was associated with an increased risk of residual tumor (HR = 1.09; 95% CI 1.01-1.19; p = 0.033) as well as death (HR = 1.23; 95% CI 1.11-1.36; p ≤ 0.001).

CONCLUSION

Incremental 30-day wait times are associated with a 9% increased risk of residual tumor and a 23% increased risk of death. We have identified system gaps where quality improvement measures can be implemented to reduce wait times and allocate resources for future RFA treatment, which may improve both quality and efficiency of HCC care.

Role of the Ocean's AMOC in setting the Uptake Efficiency of Transient Tracers

The central role played by the ocean's Atlantic Meridional Overturning Circulation (AMOC) in the uptake and sequestration of transient tracers is studied in a series of experiments with the GISS and MIT ocean circulation models. Forced by observed atmospheric timeseries of CFC-11, both models exhibit realistic distributions in the ocean, with similar surface biases but different response over time. To better understand what controls uptake, we ran idealized forcing experiments in which the AMOC strength varied over a wide range, bracketing the observations. We found that differences in the strength and vertical scale of the AMOC largely accounted for the different rates of CFC-11 uptake and vertical distribution thereof. A 2-box model enables us to quantify, and relate uptake efficiency of passive tracers to AMOC strength and how uptake efficiency decreases in time. We also discuss the relationship between passive tracer and heat uptake efficiency, of which the latter controls the transient climate response to anthropogenic forcing in the North Atlantic. We find that heat uptake efficiency is substantially less (by about a factor of five) than that for a passive tracer.

Interactive nature of climate change and aerosol forcing

The effect of changing cloud cover on climate, based on cloud-aerosol interactions, is one of the major unknowns for climate forcing and climate sensitivity. It has two components: (1) the impact of aerosols on clouds and climate due to in situ interactions (i.e., rapid response) and (2) the effect of aerosols on the cloud feedback that arises as climate changes-climate feedback response. We examine both effects utilizing the NASA Goddard Institute for Space Studies ModelE2 to assess the indirect effect, with both mass-based and microphysical aerosol schemes, in transient twentieth century simulations. We separate the rapid response and climate feedback effects by making simulations with a coupled version of the model as well as one with no sea surface temperature or sea ice response ("atmosphere-only" simulations). We show that the indirect effect of aerosols on temperature is altered by the climate feedbacks following the ocean response, and this change differs depending upon which aerosol model is employed. Overall, the effective radiative forcing (ERF) for the "direct effect" of aerosol-radiation interaction (ERFari) ranges between -0.2 and -0.6 W m^-2 for atmosphere-only experiments, while the total effective radiative forcing, including[C0]the indirect effect (ERFari+aci) varies between about -0.4 and -1.1 W m^-2 for atmosphere-only simulations; both ranges are in agreement with those given in Intergovernmental Panel on Climate Change (2013). Including the full feedback of the climate system lowers these ranges to -0.2 to -0.5 W m^-2 for ERFari and -0.3 to -0.74 W m^-2 for ERFari+aci. With both aerosol schemes, the climate change feedbacks have reduced the global average indirect radiative effect of atmospheric aerosols relative to what the emission changes would have produced, at least partially due to its effect on tropical upper tropospheric clouds.

Modeling the QBO-Improvements resulting from higher-model vertical resolution

Using the NASA Goddard Institute for Space Studies (GISS) climate model, it is shown that with proper choice of the gravity wave momentum flux entering the stratosphere and relatively fine vertical layering of at least 500 m in the upper troposphere-lower stratosphere (UTLS), a realistic stratospheric quasi-biennial oscillation (QBO) is modeled with the proper period, amplitude, and structure down to tropopause levels. It is furthermore shown that the specified gravity wave momentum flux controls the QBO period whereas the width of the gravity wave momentum flux phase speed spectrum controls the QBO amplitude. Fine vertical layering is required for the proper downward extension to tropopause levels as this permits wave-mean flow interactions in the UTLS region to be resolved in the model. When vertical resolution is increased from 1000 to 500 m, the modeled QBO modulation of the tropical tropopause temperatures increasingly approach that from observations, and the "tape recorder" of stratospheric water vapor also approaches the observed. The transport characteristics of our GISS models are assessed using age-of-air and N₂O diagnostics, and it is shown that some of the deficiencies in model transport that have been noted in previous GISS models are greatly improved for all of our tested model vertical resolutions. More realistic tropical-extratropical transport isolation, commonly referred to as the "tropical pipe," results from the finer vertical model layering required to generate a realistic QBO.

THE EARTH SYSTEM PREDICTION SUITE: Toward a Coordinated U.S. Modeling Capability

The Earth System Prediction Suite (ESPS) is a collection of flagship U.S. weather and climate models and model components that are being instrumented to conform to interoperability conventions, documented to follow metadata standards, and made available either under open source terms or to credentialed users. The ESPS represents a culmination of efforts to create a common Earth system model architecture, and the advent of increasingly coordinated model development activities in the U.S. ESPS component interfaces are based on the Earth System Modeling Framework (ESMF), community-developed software for building and coupling models, and the National Unified Operational Prediction Capability (NUOPC) Layer, a set of ESMF-based component templates and interoperability conventions. This shared infrastructure simplifies the process of model coupling by guaranteeing that components conform to a set of technical and semantic behaviors. The ESPS encourages distributed, multi-agency development of coupled modeling systems, controlled experimentation and testing, and exploration of novel model configurations, such as those motivated by research involving managed and interactive ensembles. ESPS codes include the Navy Global Environmental Model (NavGEM), HYbrid Coordinate Ocean Model (HYCOM), and Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS®); the NOAA Environmental Modeling System (NEMS) and the Modular Ocean Model (MOM); the Community Earth System Model (CESM); and the NASA ModelE climate model and GEOS-5 atmospheric general circulation model.

KCNK9 imprinting syndrome-further delineation of a possible treatable disorder

Patients with KCNK9 imprinting syndrome demonstrate congenital hypotonia, variable cleft palate, normal MRIs and EEGs, delayed development, and feeding problems. Associated facial dysmorphic features include dolichocephaly with bitemporal narrowing, short philtrum, tented upper lip, palatal abnormalities, and small mandible. This disorder maps to chromosomal region 8q24, and it is caused by a specific missense mutation 770G>A in exon 2, replacing glycine at position 236 by arginine (G236R) in the maternal copy of KCNK9 within this locus. KCNK9 (also called TASK3) encodes a member of the two pore- domain potassium channel (K2P) subfamily. This gene is normally imprinted with paternal silencing, thus a mutation in the maternal copy of the gene will result in disease, whereas a mutation in the paternal copy will have no effect. Exome sequencing in four new patients with developmental delay and central hypotonia revealed de novo G236R mutations. Older members of a previously reported Arab-Israeli family have intellectual disability of variable severity, persistent feeding difficulties in infancy with dysphagia of liquids and dysphonia with a muffled voice in early adulthood, generalized hypotonia, weakness of proximal muscles, elongated face with narrow bitemporal diameter, and reduced facial movements. We describe the clinical features in four recently recognized younger patients and compare them with those found in members of the originally reported Arab-Israeli family and suggest this may be a treatable disorder. © 2016 Wiley Periodicals, Inc.

Community-Based Participatory Research Conceptual Model: Community Partner Consultation and Face Validity

A national community-based participatory research (CBPR) team developed a conceptual model of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the model primarily developed through academic literature and expert consensus building, we sought community input to assess face validity and acceptability. Our research team conducted semi-structured focus groups with six partnerships nationwide. Participants validated and expanded on existing model constructs and identified new constructs based on "real-world" praxis, resulting in a revised model. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the model, we found community face validity and capacity to adapt the model to diverse contexts. We recommend partnerships use and adapt the CBPR model and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals.