Quantitative tests of albendazole resistance in Caenorhabditis elegans beta-tubulin mutants.

Benzimidazole (BZ) anthelmintics are among the most important treatments for parasitic nematode infections in the developing world. Widespread BZ resistance in veterinary parasites and emerging resistance in human parasites raise major concerns for the continued use of BZs. Knowledge of the mechanisms of resistance is necessary to make informed treatment decisions and circumvent resistance. Benzimidazole resistance has traditionally been associated with mutations and natural variants in the C. elegans beta-tubulin gene ben-1 and orthologs in parasitic species. However, variants in ben-1 alone do not explain the differences in BZ responses across parasite populations. Here, we examined the roles of five C. elegans beta-tubulin genes (tbb-1, mec-7, tbb-4, ben-1, and tbb-6) in the BZ response as well as to determine if another beta-tubulin acts redundantly with ben-1. We generated C. elegans strains with a loss of each beta-tubulin gene, as well as strains with a loss of tbb-1, mec-7, tbb-4, or tbb-6 in a genetic background that also lacks ben-1. We found that the loss of ben-1 conferred the maximum level of resistance following exposure to a single concentration of albendazole, and the loss of a second beta-tubulin gene did not alter the level of resistance. However, additional traits other than larval development could be affected by the loss of additional beta-tubulins, and the roles of other beta-tubulin genes might be revealed at different albendazole concentrations. Therefore, further work is needed to fully define the possible roles of other beta-tubulin genes in the BZ response.

Cyprocide selectively kills nematodes via cytochrome P450 bioactivation.

Left unchecked, plant-parasitic nematodes have the potential to devastate crops globally. Highly effective but non-selective nematicides are justifiably being phased-out, leaving farmers with limited options for managing nematode infestation. Here, we report our discovery of a 1,3,4-oxadiazole thioether scaffold called Cyprocide that selectively kills nematodes including diverse species of plant-parasitic nematodes. Cyprocide is bioactivated into a lethal reactive electrophilic metabolite by specific nematode cytochrome P450 enzymes. Cyprocide fails to kill organisms beyond nematodes, suggesting that the targeted lethality of this pro-nematicide derives from P450 substrate selectivity. Our findings demonstrate that Cyprocide is a selective nematicidal scaffold with broad-spectrum activity that holds the potential to help safeguard our global food supply.

Inequality in high-cost borrowing and unemployment insurance generosity in US states during the COVID-19 pandemic.

US consumers may turn to the private market for credit when income and government benefits fall short. The most vulnerable consumers have access only to the highest-cost loans. Prior research on trade-offs of credit with government welfare support cannot distinguish between distinct forms of unsecured credit due to data limitations. Here we provide insight on credit-welfare state trade-offs vis-à-vis unemployment insurance generosity by leveraging a large sample of credit data that allow us to separate credit cards, personal loans and alternative financial services loans and to analyse heterogeneity in credit use by household income. We find that more generous state unemployment insurance benefits were associated with a lower probability of high-cost credit use during the first seven quarters of the coronavirus disease 2019 (COVID-19) pandemic. This inverse association was concentrated among consumers living in low-income households. Our results support theories that public benefits are inversely associated with the use of costly credit.

Tetranuclear Polypyridylruthenium(II) Complexes as Selective Nucleic Acid Stains for Flow Cytometric Analysis of Monocytic and Epithelial Lung Carcinoma Large Extracellular Vesicles.

Selective staining of extracellular vesicles (EVs) is a major challenge for diagnostic and therapeutic applications. Herein, the EV labeling properties of a new class of tetranuclear polypyridylruthenium(II) complexes, Rubb7-TNL and Rubb7-TL, as phosphorescent stains are described. These new stains have many advantages over standard stains to detect and characterize EVs, including: high specificity for EV staining versus cell staining; high phosphorescence yields; photostability; and a lack of leaching from EVs until incorporation with target cells. As an example of their utility, large EVs released from control (basal) or lipopolysaccharide (LPS)-stimulated THP-1 monocytic leukemia cells were studied as a model of immune system EVs released during bacterial infection. Key findings from EV staining combined with flow cytometry were as follows: (i) LPS-stimulated THP-1 cells generated significantly larger and more numerous large EVs, as compared with those from unstimulated cells; (ii) EVs retained native EV physical properties after staining; and (iii) the new stains selectively differentiated intact large EVs from artificial liposomes, which are models of cell membrane fragments or other lipid-containing debris, as well as distinguished two distinct subpopulations of monocytic EVs within the same experiment, as a result of biochemical differences between unstimulated and LPS-stimulated monocytes. Comparatively, the staining patterns of A549 epithelial lung carcinoma-derived EVs closely resembled those of THP-1 cell line-derived EVs, which highlighted similarities in their selective staining despite their distinct cellular origins. This is consistent with the hypothesis that these new phosphorescent stains target RNA within the EVs.

Quantifying the fitness effects of resistance alleles with and without anthelmintic selection pressure using Caenorhabditis elegans.

Albendazole (a benzimidazole) and ivermectin (a macrocyclic lactone) are the two most commonly co-administered anthelmintic drugs in mass-drug administration programs worldwide. Despite emerging resistance, we do not fully understand the mechanisms of resistance to these drugs nor the consequences of delivering them in combination. Albendazole resistance has primarily been attributed to variation in the drug target, a beta-tubulin gene. Ivermectin targets glutamate-gated chloride channels (GluCls), but it is unknown whether GluCl genes are involved in ivermectin resistance in nature. Using Caenorhabditis elegans, we defined the fitness costs associated with loss of the drug target genes singly or in combinations of the genes that encode GluCl subunits. We quantified the loss-of-function effects on three traits: (i) multi-generational competitive fitness, (ii) fecundity, and (iii) development. In competitive fitness and development assays, we found that a deletion of the beta-tubulin gene ben-1 conferred albendazole resistance, but ivermectin resistance required the loss of two GluCl genes (avr-14 and avr-15). The fecundity assays revealed that loss of ben-1 did not provide any fitness benefit in albendazole conditions and that no GluCl deletion mutants were resistant to ivermectin. Next, we searched for evidence of multi-drug resistance across the three traits. Loss of ben-1 did not confer resistance to ivermectin, nor did loss of any single GluCl subunit or combination confer resistance to albendazole. Finally, we assessed the development of 124 C. elegans wild strains across six benzimidazoles and seven macrocyclic lactones to identify evidence of multi-drug resistance between the two drug classes and found a strong phenotypic correlation within a drug class but not across drug classes. Because each gene affects various aspects of nematode physiology, these results suggest that it is necessary to assess multiple fitness traits to evaluate how each gene contributes to anthelmintic resistance.

Quantitative tests of albendazole resistance in beta-tubulin mutants.

Benzimidazole (BZ) anthelmintics are among the most important treatments for parasitic nematode infections in the developing world. Widespread BZ resistance in veterinary parasites and emerging resistance in human parasites raise major concerns for the continued use of BZs. Knowledge of the mechanisms of resistance is necessary to make informed treatment decisions and circumvent resistance. Benzimidazole resistance has traditionally been associated with mutations and natural variants in the C. elegans beta-tubulin gene ben-1 and orthologs in parasitic species. However, variants in ben-1 alone do not explain the differences in BZ responses across parasite populations. Here, we examine the roles of five C. elegans beta-tubulin genes (tbb-1, mec-7, tbb-4, ben-1, and tbb-6) to identify the role each gene plays in BZ response. We generated C. elegans strains with a loss of each beta-tubulin gene, as well as strains with a loss of tbb-1, mec-7, tbb-4, or tbb-6 in a genetic background that also lacks ben-1 to test beta-tubulin redundancy in BZ response. We found that only the individual loss of ben-1 conferred a substantial level of BZ resistance, although the loss of tbb-1 was found to confer a small benefit in the presence of albendazole (ABZ). The loss of ben-1 was found to confer an almost complete rescue of animal development in the presence of 30 µM ABZ, likely explaining why no additive effects caused by the loss of a second beta-tubulin were observed. We demonstrate that ben-1 is the only beta-tubulin gene in C. elegans where loss confers substantial BZ resistance.

Quantifying the fitness effects of resistance alleles with and without anthelmintic selection pressure using Caenorhabditis elegans.

Albendazole and ivermectin are the two most commonly co-administered anthelmintic drugs in mass-drug administration programs worldwide. Despite emerging resistance, we do not fully understand the mechanisms of resistance to these drugs nor the consequences of delivering them in combination. Albendazole resistance has primarily been attributed to variation in the drug target, a beta-tubulin gene. Ivermectin targets glutamate-gated chloride channel (GluCl) genes, but it is unknown whether these genes are involved in ivermectin resistance in nature. Using Caenorhabditis elegans, we defined the fitness costs associated with loss of the drug target genes singly or in combinations of the genes that encode GluCl subunits. We quantified the loss-of function effects on three traits: (i) multi-generational competitive fitness, (ii) fecundity, and (iii) development. In competitive fitness and development assays, we found that a deletion of the beta-tubulin gene ben-1 conferred albendazole resistance, but ivermectin resistance required loss of two GluCl genes (avr-14 and avr-15) or loss of three GluCl genes (avr-14, avr-15, and glc-1). The fecundity assays revealed that loss of ben-1 did not provide any fitness benefit in albendazole and that no GluCl deletion mutants were resistant to ivermectin. Next, we searched for evidence of multi-drug resistance across the three traits. Loss of ben-1 did not confer resistance to ivermectin, nor did loss of any single GluCl subunit or combination confer resistance to albendazole. Finally, we assessed the development of 124 C. elegans wild strains across six benzimidazoles and seven macrocyclic lactones to identify evidence of multi-drug resistance between the two drug classes and found a strong phenotypic correlation within a drug class but not across drug classes. Because each gene affects various aspects of nematode physiology, these results suggest that it is necessary to assess multiple fitness traits to evaluate how each gene contributes to anthelmintic resistance.

Behavioral, metabolic, and lipidomic characterization of the 5xFADxTg30 mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is associated with both extracellular amyloid-ß (Aß) plaques and intracellular tau-containing neurofibrillary tangles (NFT). We characterized the behavioral, metabolic and lipidomic phenotype of the 5xFADxTg30 mouse model which contains overexpression of both Aß and tau. Our results independently reproduce several phenotypic traits described previously for this model, while providing additional characterization. This model develops many aspects associated with AD including frailty, decreased survival, initiation of aspects of cognitive decline and alterations to specific lipid classes and molecular lipid species in the plasma and brain. Notably, some sex-specific differences exist in this model and motor impairment with aging in this model does compromise the utility of the model for some movement-based behavioral assessments of cognitive function. These findings provide a reference for individuals interested in using this model to understand the pathology associated with elevated Aß and tau or for testing potential therapeutics for the treatment of AD.

KatG catalase deficiency confers bedaquiline hyper-susceptibility to isoniazid resistant Mycobacterium tuberculosis.

Multidrug-resistant tuberculosis (MDR-TB) is a growing source of global mortality and threatens global control of tuberculosis (TB) disease. The diarylquinoline bedaquiline (BDQ) recently emerged as a highly efficacious drug against MDR-TB, defined as resistance to the first-line drugs isoniazid (INH) and rifampin. INH resistance is primarily caused by loss-of-function mutations in the catalase KatG, but mechanisms underlying BDQ's efficacy against MDR-TB remain unknown. Here we employ a systems biology approach to investigate BDQ hyper-susceptibility in INH-resistant Mycobacterium tuberculosis . We found hyper-susceptibility to BDQ in INH-resistant cells is due to several physiological changes induced by KatG deficiency, including increased susceptibility to reactive oxygen species and DNA damage, remodeling of transcriptional programs, and metabolic repression of folate biosynthesis. We demonstrate BDQ hyper-susceptibility is common in INH-resistant clinical isolates. Collectively, these results highlight how altered bacterial physiology can impact drug efficacy in drug-resistant bacteria.

Internally versus externally trained residents and fellows hired as attendings at a large integrated healthcare system: a 20-year retrospective study.

BACKGROUND: There remains a question of whether graduates trained internally are different than those trained elsewhere. We examine the difference between physicians trained within our Graduate Medical Education (GME) programs versus physicians trained elsewhere. Our large integrated healthcare system is unique in addressing this objective due to its large physician labor hiring needs across different specialties of GME graduates. METHODS: A retrospective review was performed from Jan 2000 to August 2020 of Kaiser Permanente Southern California (KPSC) physicians hired: KPSC GME trained versus non-KPSC GME trained. We examined five variables: retention, leadership (current or historical), physician relations cases, member appraisal of physician and provider services survey (MAPPS) scores, and rate of board certification. Chi-square test of proportions was used for comparison, p < 0.05 was significant. RESULTS: From Jan 2000 to August 2020, 2940 residents and fellows graduated from KPSC GME programs, of which 1127 (38%) were hired on at KPSC as full time attendings. Across all five metrics (Retention 82% vs 76% (p = < 0.01), Leadership [current 13% vs 10% (p = < 0.01)or historical 17% vs 14% (p = 0.01)], Physician Relations 23% vs 26% (p = 0.04), MAPPS 75% vs 69% (p = < 0.01), and Board Certification 81% vs 74% (p = < 0.01)), KPSC outperformed non-KPSC GME-trained physicians to a statistically significant degree. CONCLUSIONS: We have shown that an internally sponsored GME program can represent an opportunity for recruitment of physicians that may have higher retention rates, higher probability of being physician leaders, decreased likelihood of physician relations issues, improved patient satisfaction, and increased rates of board certification.

A tetranuclear polypyridylruthenium(II) complex as a selective stain for extracellular vesicle penetration through brain microvascular endothelium.

A new photoluminescent polypyridylruthenium(II) stain for extracellular vesicles (EVs) released from lipopolysaccharide-stimulated THP-1 monocytes enabled important new insights into how the bacteria-induced immune system affects the blood-brain barrier (BBB). These included previously unknown aspects of EV interactions with BBB microvascular endothelial cells and the extracellular matrix relevant to human brain diseases.

Quantifying sustained pain worsening in knee osteoarthritis.

OBJECTIVE: Recent work suggests that many persons with knee osteoarthritis (OA) experience stable symptoms over time. Whether patients experience periods of symptom exacerbation or flare which interrupt this stable course, and how long such periods last, has received little study. Our objective is to describe the frequency and duration of episodes of pain worsening in persons with knee OA. METHODS: We selected participants from the Osteoarthritis Initiative with radiographic, symptomatic knee OA. We defined a clinically relevant increase in knee pain as an increase in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain of ≥9 points. We defined sustained worsening as maintaining at least 80% of the initial increase. We used Poisson regression to estimate the incidence rate (IR) of episodes of pain worsening. RESULTS: 1093 participants were included in the analysis. Eighty-eight percent had ≥1 increase in WOMAC pain ≥9 points (IR: 26.3 per 100 person years (95% CI: 25.2, 27.4)). Forty-eight percent had ≥1 episode of sustained worsening (IR: 9.7 per 100 person-years (95% CI: 8.9, 10.5)). Elevated pain was maintained an average of 2.4 years after the initial increase. CONCLUSION: Most participants with knee OA reported at least one clinically relevant increase in WOMAC pain, but fewer than half experienced an episode of sustained pain worsening. These individual-level data portray a more nuanced and fluctuating course of OA pain than suggested by trajectory studies. These data could be useful in shared decision-making regarding prognosis and treatment choices in persons affected by symptomatic knee OA.

Controlled Continuous Evolution of Enzymatic Activity Screened at Ultrahigh Throughput Using Drop-Based Microfluidics.

Enzymes are highly specific catalysts delivering improved drugs and greener industrial processes. Naturally occurring enzymes must typically be optimized which is often accomplished through directed evolution; however, this is still a labor- and capital-intensive process, due in part to multiple molecular biology steps including DNA extraction, in vitro library generation, transformation, and limited screening throughput. We present an effective and broadly applicable continuous evolution platform that enables controlled exploration of fitness landscape to evolve enzymes at ultrahigh throughput based on direct measurement of enzymatic activity. This drop-based microfluidics platform cycles cells between growth and mutagenesis followed by screening with minimal human intervention, relying on the nCas9 chimera with mutagenesis polymerase to produce in vivo gene diversification using sgRNAs tiled along the gene. We evolve alditol oxidase to change its substrate specificity towards glycerol, turning a waste product into a valuable feedstock. We identify a variant with a 10.5-fold catalytic efficiency.

Research participants may not recall their participation but have a better understanding of alternative management options than patients in routine care.

BACKGROUND: Patient understanding of care interventions, of the clinical uncertainty, and of their participation in clinical research is often poor. We hypothesized that compared to routine care, patients would better understand the prevailing uncertainty when they participated in research. METHODS: A questionnaire was administered to patients at the time they attended a follow-up neurovascular clinic 4 to 52 weeks after a care episode where they did or did not participate in a clinical trial. Patients were not reminded whether they had previously participated in a clinical trial. Questions concerned their understanding of the risks/benefits of interventions, the availability of alternative options, whether their personal opinion was taken into consideration, the reason for the final decision, their confidence at having received the best management, and whether they had been research participants. RESULTS: Between June 2019 and June 2020, 167 patients were recruited; 71 had truly been research participants, while 96 had not. A greater proportion of research patients were aware of the existence of management alternatives (65% versus 44%; P=0.008). Patients of both groups believed their personal opinion counted in the final decision (76% versus 70%), and patients were equally confident that they had received the best management (94%). Research patients believed they had participated in research 46% of the time, compared to 12% of routine care patients (P=0.003). CONCLUSION: Many patients do not recall that they participated in a clinical trial, but they have a better understanding of the clinical uncertainty and of the availability of alternative management options.

A Systematic Review of Autistic People and the Criminal Justice System: An Update of King and Murphy (2014).

The purpose of this paper was to determine whether recommendations made by King & Murphy (Journal of Autism and Developmental Disorders 44:2717-2733, 2014) in their review of the evidence on autistic people in contact with the criminal justice system (CJS) have been addressed. Research published since 2013 was systematically examined and synthesised. The quality of 47 papers was assessed using the Mixed Methods Appraisal Tool. Findings suggest a limited amount of good quality research has been conducted that has focused on improving our understanding of autistic people in contact with the CJS since 2013. Methodological limitations make direct comparisons between autistic and non-autistic offenders difficult. Autistic people commit a range of crimes and appear to have unique characteristics that warrant further exploration (i.e., vulnerabilities, motivations for offending).

The role of RBC antigen transgene integration sites on RBC biology in mice.

BACKGROUND: Transgenic mice expressing RBC specific antigens are widely used in mechanistic studies of RBC alloimmunization. Existing RBC donor strains have random transgene integration, potentially disrupting host elements that can confound biological interpretation. STUDY DESIGN AND METHODS: Integration site and genomic alterations were characterized by both targeted locus amplification and congenic backcrossing in the five most commonly used RBC alloantigen donor strains (KEL-K2hi , KEL-K2med , and KEL-K2lo , and KEL-K1). A targeted transgenic approach was developed to allow RBC specific transgene expression from a safe harbor locus (ROSA26). Alloimmune responses were assessed by transfusing alloantigen expressing RBCs into wild-type recipients and measuring alloantibodies by flow cytometry. RESULTS/FINDINGS: Four of the five analyzed strains had at least one gene disrupted by the transgene integration but none of the disrupted genes are known to be involved in RBC biology. The integration of KEL-K2med potentially altered the immunological properties of RBCs, although the biological significance of the observed changes is unclear. The ROSA26 targeted approach resulted in a single copy of the transgene that maintains RBC specific expression without random disruption of genomic elements. CONCLUSION: These findings provide a detailed characterization of genomic disruption by transgene integration found in commonly used RBC donor strains that is relevant to numerous previous publications as well as future studies. With the possible exception of KEL-K2med , transgene integration is not predicted to affect RBC biology in existing models, and new models can avoid this concern using the described targeted transgenic approach.

The turkey ascarid, Ascaridia dissimilis, as a model genetic system.

Parasitic nematodes cause significant effects on humans each year, with the most prevalent being Ascaris lumbricoides. Benzimidazoles (BZ) are the most widely used anthelmintic drug in humans, and although the biology of resistance to this drug class is understood in some species, resistance is poorly characterized in ascarids. Models such as Caenorhabditis elegans were essential in developing our current understanding of BZ resistance, but more closely related model nematodes are needed to understand resistance in ascarids. Here, we propose a new ascarid model species that infects turkeys, Ascaridia dissimilis, to develop a better understanding of BZ resistance.

Understanding the research-care demarcation and why it must be revised.

BACKGROUND: A clean-cut separation between research and care was artificially created at the time of the Belmont report more than 40 years ago. The demarcation was initially controversial but eventually was implemented for political reasons. We examine why it must be revised. METHODS: We review historical research scandals as well as the theoretical basis for the Belmont demarcation. We then discuss consequences on medical practice and propose an alternative. DISCUSSION: Most research scandals involved abusing human beings supposedly for the sake of science. Belmont commissioners were aware the research/care problem was double-headed. While research subjects should be protected from abuse in the research context, patients need to be protected from unvalidated medical and surgical interventions in the care context. For political reasons the Commission recommended the regulation of research but to leave medical practice untouched. Thus the Commission had to distinguish research from care. The notion of 'generalizable knowledge' was introduced to define and regulate research, but the inadvertent result was that by trying to protect research subjects, the regulation has not only failed to protect all other patients, but also encouraged the widespread practice of unvalidated interventions within the care context. The notion of validated care should be re-introduced into a proper analysis of the care-research demarcation, for care research is an integral ingredient of a good medical practice. CONCLUSION: The research-care demarcation should be revised to leave room for the validated/unvalidated care distinction. Care research, essential to guide medical practice, should be facilitated at all levels.

Does gabapentin provide benefit for patients with knee OA? A benefit-harm and cost-effectiveness analysis.

OBJECTIVE: Gabapentin can treat neuropathic pain syndromes and has increasingly been prescribed to treat nociplastic pain. Some patients with knee osteoarthritis (OA) suffer from both nociceptive and nociplastic pain. We examined the cost-effectiveness of adding gabapentin to knee OA care. METHOD: We used the Osteoarthritis Policy Model, a validated Monte Carlo simulation of knee OA, to examine the value of gabapentin in treating knee OA by comparing three strategies: 1) usual care, gabapentin sparing (UC-GS); 2) targeted gabapentin (TG), which provides gabapentin plus usual care for those who screen positive for nociplastic pain on the modified PainDETECT questionnaire (mPD-Q) and usual care only for those who screen negative; and 3) universal gabapentin plus usual care (UG). Outcomes included cumulative quality-adjusted life years (QALYs), lifetime direct medical costs, and incremental cost-effectiveness ratios (ICERs), discounted at 3% annually. We derived model inputs from published literature and national databases and varied key input parameters in sensitivity analyses. RESULTS: UC-GS dominated both gabapentin-containing strategies, as it led to lower costs and more QALYs. TG resulted in a cost increase of $689 and a cumulative QALY reduction of 0.012 QALYs. UG resulted in a further $1,868 cost increase and 0.036 QALY decrease. The results were robust to plausible changes in input parameters. The lowest TG strategy ICER of $53,000/QALY was reported when mPD-Q specificity was increased to 100% and AE rate was reduced to 0%. CONCLUSION: Incorporating gabapentin into care for patients with knee OA does not appear to offer good value.