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Background: The increase in reports of resistance to macrocyclic lactones in the canine heartworm, Dirofilaria immitis is alarming. While DNA based tests have been well-validated, they can be expensive. In a previous study, we showed that two biochemical tests adapted to a 96- well plate format and read in a spectrophotometer could detect differences among lab validated D. immitis isolates. The two tests- Resazurin reduction and Hoechst 33342 efflux—detect metabolism and P-glycoprotein activity respectively in microfilariae isolated from infected dog blood. Methods: Our objective was to optimize the two assays further by testing various assay parameters in D. immitis isolates not tested previously. We tested microfilarial seeding density, incubation time and the effect of in vitro treatment with ivermectin and doxycycline in five other D. immitis isolates—JYD-34, Big Head, Berkeley, Georgia III and LOL. All assays were performed in 3 technical replicates and 2–4 biological replicates. To understand the molecular basis of the assays, we also performed qPCR for selected drug metabolism and elimination associated genes of the ABC transporter and cytochrome P450 gene families. Results: Metabolism and ABC transporter activity as detected by these assays varied between strains. Anthelmintic status (resistant or susceptible) did not correlate with metabolism or P-gp efflux. Basal transcriptional variations were found between strains in ABC transporter and cytochrome P450 genes. Conclusions: These assays provide a greater understanding of the biochemical variation among isolates of D. immitis, which can be exploited in the future to develop in vitro diagnostic tests capable of differentiating susceptible and resistant isolates. [ABSTRACT FROM AUTHOR]

This study investigates the predictability of downslope windstorms located in Santa Barbara County, California, locally referred to as Sundowner winds, from both observed relationships and a high-resolution, operational numerical weather prediction model. We focus on April 2022, during which the Sundowner Winds Experiment (SWEX) was conducted. We further refine our study area to the Montecito region owing to some of the highest wind measurements occurring at or near surface station MTIC1, situated on the coast-facing slope overlooking the area. Fires are not uncommon in this area, and the difficulty of egress makes the population particularly vulnerable. Area forecasters often use the sea-level pressure difference (Δ SLP) between Santa Barbara Airport (KSBA) and locations to the north such as Bakersfield (KBFL) to predict Sundowner windstorm occurrence. Our analysis indicates that Δ SLP by itself is prone to high false alarm rates and offers little information regarding downslope wind onset, duration, or magnitude. Additionally, our analysis shows that the high-resolution rapid refresh (HRRR) model has limited predictive skill overall for forecasting winds in the Montecito area. The HRRR, however, skillfully predicts KSBA-KBFL Δ SLP, as does GraphCast, a machine learning weather prediction model. Using a logistic regression model we were able to predict the occurrence of winds exceeding 9 m s − 1 with a high probability of detection while minimizing false alarm rates compared to other methods analyzed. This provides a refined and easily computed algorithm for operational applications. [ABSTRACT FROM AUTHOR]

A novel group of biocidal compounds are the Crystal 3D (Cry) and Cytolytic (Cyt) proteins produced by Bacillus thuringiensis (Bt). Some Bt Cry proteins have a selective nematocidal activity, with Cry5B being the most studied. Cry5B kills nematode parasites by binding selectively to membrane glycosphingolipids, then forming pores in the cell membranes of the intestine leading to damage. Cry5B selectively targets multiple species of nematodes from different clades and has no effect against mammalian hosts. Levamisole is a cholinergic anthelmintic that acts by selectively opening L-subtype nicotinic acetylcholine receptor ion-channels (L-AChRs) that have been found on muscles of nematodes. A synergistic nematocidal interaction between levamisole and Cry5B at the whole-worm level has been described previously, but the location, mechanism and time-course of this synergism is not known. In this study we follow the timeline of the effects of levamisole and Cry5B on the Ca2+ levels in enterocyte cells in the intestine of Ascaris suum using fluorescence imaging. The peak Ca2+ responses to levamisole were observed after approximately 10 minutes while the peak responses to activated Cry5B were observed after approximately 80 minutes. When levamisole and Cry5B were applied simultaneously, we observed that the responses to Cry5B were bigger and occurred sooner than when it was applied by itself. It is proposed that the synergism is due to the cytoplasmic Ca2+ overload that is induced by the combination of levamisole opening Ca2+ permeable L-subtype nAChRs and the Ca2+ permeable Cry5B toxin pores produced in the enterocyte plasma membranes. The effect of levamisole potentiates and speeds the actions of Cry5B that gives rise to bigger Ca2+ overloads that accelerates cell-death of the enterocytes. Author summary: The neglected tropical diseases are a diverse set of infectious diseases which are common in low-income populations of Asia, Africa and the Americas. They include soil-transmitted helminth (STH) infections produced by the parasitic nematode Ascaris lumbricoides (= Ascaris suum). There are no effective vaccines, so mass drug administration (MDA) to control and prevent infection is the only practical option. With the limited number of anthelmintic drugs available for treatment, there is an increasing concern about the development of resistance. The use of combinations of anthelmintics, particularly if they are additive, is important for the delay of the onset of resistance. Here we describe synergistic interactions of levamisole and Cry5B mediated by Ca++ in A. suum intestine enterocytes. We have been able to make these new observations because of our access to A. suum parasites and development of our techniques for studying Ca++ signaling in the intestine of this nematode parasite, a site of the interaction of these two anthelmintic drugs. Our study provides new insights for development of effective STH combination therapies of anthelmintic drugs for slowing development of resistance with continued mass drug administration and understanding the nematode parasite intestine as a major target for combinations of anthelmintic drugs. [ABSTRACT FROM AUTHOR]

Objective: Heterogeneous brief non-pharmacological interventions and guidelines exist to treat the burgeoning presentations to both emergency department and inpatient settings, for those in a crisis of mental ill-health. We systematically reviewed the literature to create a taxonomy of these brief non-pharmacological interventions, and review their evaluation methods and effectiveness. Method: We conducted a systematic review across Cochrane, CINAHL, DARE, Embase, MEDLINE, PsycINFO databases. Studies meeting quality criteria, using Joanna Briggs Institute tools, were eligible. Interventions were categorised, and outcomes synthesised. Results: Thirty-nine studies were included: 8 randomised controlled trials, 17 quasi-experimental, 11 qualitative studies, and 3 file audits. Taxonomy produced six coherent intervention types: Skills-focussed, Environment-focussed, Special Observation, Psychoeducation, Multicomponent Group and Multicomponent Individual. Despite this, a broad and inconsistent range of outcome measures reflected different outcome priorities and prevented systematic comparison of different types of intervention or meta-analysis. Few brief non-pharmacological interventions had consistent evidential support: sensory modulation rooms consistently improved distress in inpatient settings. Short admissions may reduce suicide attempts and readmission, if accompanied by psychotherapy. Suicide-specific interventions in emergency departments may improve depressive symptoms, but not suicide attempt rates. There was evidence that brief non-pharmacological interventions did not reduce incidence of self-harm on inpatient wards. We found no evidence for frequently used interventions such as no-suicide contracting, special observation or inpatient self-harm interventions. Conclusion: Categorising brief non-pharmacological interventions is feasible, but an evidence base for many is severely limited if not missing. Even when there is evidence, the inconsistency in outcomes often precludes clinicians from making inferences, although some interventions show promise. [ABSTRACT FROM AUTHOR]

Purpose: Innate immune activation plays a critical role in the onset and progression of many diseases. While positron emission tomography (PET) imaging provides a non-invasive means to visualize and quantify such immune responses, most available tracers are not specific for innate immune cells. To address this need, we developed [18F]OP-801 by radiolabeling a novel hydroxyl dendrimer that is selectively taken up by reactive macrophages/microglia and evaluated its ability to detect innate immune activation in mice following lipopolysaccharide (LPS) challenge. Procedures: OP-801 was radiolabeled in two steps: [18F]fluorination of a tosyl precursor to yield [18F]3-fluoropropylazide, followed by a copper-catalyzed click reaction. After purification and stability testing, [18F]OP-801 (150-250 μCi) was intravenously injected into female C57BL/6 mice 24 h after intraperitoneal administration of LPS (10 mg/kg, n=14) or saline (n=6). Upon completing dynamic PET/CT imaging, mice were perfused, and radioactivity was measured in tissues of interest via gamma counting or autoradiography. Results: [18F]OP-801 was produced with >95% radiochemical purity, 12–52 μCi/μg specific activity, and 4.3±1.5% decay-corrected yield. Ex vivo metabolite analysis of plasma samples (n=4) demonstrated high stability in mice (97±3% intact tracer >120 min post-injection). PET/CT images of mice following LPS challenge revealed higher signal in organs known to be inflamed in this context, including the liver, lung, and spleen. Gamma counting confirmed PET findings, showing significantly elevated signal in the same tissues compared to saline-injected mice: the liver (p=0.009), lung (p=0.030), and spleen (p=0.004). Brain PET/CT images (summed 50–60 min) revealed linearly increasing [18F]OP-801 uptake in the whole brain that significantly correlated with murine sepsis score (r=0.85, p<0.0001). Specifically, tracer uptake was significantly higher in the brain stem, cortex, olfactory bulb, white matter, and ventricles of LPS-treated mice compared to saline-treated mice (p<0.05). Conclusion: [18F]OP-801 is a promising new PET tracer for sensitive and specific detection of activated macrophages and microglia that warrants further investigation. [ABSTRACT FROM AUTHOR]