Perioperative arterial catheterization: A prospective evaluation of ultrasound, infection, and patient-focused outcomes.

BACKGROUND: There is little information regarding complications of arterial catheterization in modern clinical care. We aimed to determine the incidence of abnormal duplex vascular ultrasound and catheter related infections following perioperative arterial catheterization. METHODS: Patients requiring arterial catheterization for elective surgery were included and insertion details collected prospectively. Duplex ultrasound evaluation was performed 24 h after catheter removal. Symptomatic patients were identified by self-reported questionnaire. On Day 7, patients answered questions by telephone, related to the insertion site, pain, and function. Results of catheter tip and blood culture analyses were sought. Univariate associations of patient and surgical characteristics with abnormal ultrasound were assessed with p < 0.05 considered significant. RESULTS: Of 339 catheterizations, 105 (40%) had ultrasound evaluation. Catheters were indwelling for median (IQR, range) duration of 6.0 h (4.4-8.2, 1.8-28) with no catheter-related infections. There were 16 (15.2%, 95% CI 9.0%-23.6%) abnormal results, including 14 radial artery thromboses, one radial artery dissection, and one radial vein thrombosis. Those with abnormal ultrasound results were more likely to have had Arrow catheters inserted (68.8% vs 27%, p = 0.023) and more than one skin puncture (37.5% vs 26.8%, p = 0.031). Two of the 16 (12.5%) patients with abnormal ultrasound results reported new symptoms related to the hand compared with nine of the 88 (10.2%) with normal results (p = 0.1). No patients required urgent referral for management. CONCLUSIONS: Thrombosis was the most common abnormality and was usually asymptomatic. There were no infections, few post-operative symptoms, and minimal functional impairment following arterial catheterization.

Disentangling detrimental sand fly-mite interactions in a closed laboratory sand fly colony: implications for vector-borne disease studies and guidelines for overcoming severe mite infestations.

BACKGROUND: Vector sand fly colonies are a critical component of studies aimed at improving the understanding of the neglected tropical disease leishmaniasis and alleviating its global impact. However, among laboratory-colonized arthropod vectors of infectious diseases, the labor-intensive nature of sand fly rearing coupled with the low number of colonies worldwide has generally discouraged the widespread use of sand flies in laboratory settings. Among the different factors associated with the low productivity of sand fly colonies, mite infestations are a significant factor. Sand fly colonies are prone to infestation by mites, and the physical interactions between sand flies and mites and metabolites have a negative impact on sand fly larval development. METHODS: Mites were collected from sand fly larval rearing pots and morphologically identified using taxonomic keys. Upon identification, they were photographed with a scanning electron microscope. Several mite control measures were adopted in two different laboratories, one at the Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases-National Institutes of Health (Rockville, MD, USA), and the other at the University of Calgary (Calgary, AB, Canada). RESULTS: The mite species associated with sand fly colonies in the two laboratories were morphologically identified as Tyrophagus sp. and Stratiolaelaps scimitus. While complete eradication of mites in sand fly colonies is considered unrealistic, drastically reducing their population has been associated with higher sand fly productivity. CONCLUSIONS: We report a case of detrimental interaction between sand flies and Tyrophagus sp. and S. scimitus in a closed laboratory sand fly colony, discuss their impact on sand fly production and provide guidelines for limiting the mite population size in a closed laboratory colony leading to improved sand fly yields.

Comparison of Low-Level to High-Level Disinfection in Eliminating Microorganisms From Ultrasound Transducers Used on Skin: A Noninferiority Randomized Controlled Trial.

INTRODUCTION: There is a lack of international consensus as to whether high- or low-level disinfection (HLD or LLD) is required for ultrasound (US) transducers used during percutaneous procedures. This study compared the effectiveness of LLD to HLD on US transducers contaminated with microorganisms from skin. METHODS: Two identical linear US transducers repeatedly underwent either LLD or HLD during the study. Randomization determined which of these transducers was applied to left and right forearms of each participant. Swabs taken from transducers before and after reprocessing were plated then incubated for 4-5 days, after which colony forming units (CFU) were counted and identified. The primary hypothesis was the difference in the proportion of US transducers having no CFUs remaining after LLD and HLD would be less than or equal to the noninferiority margin of -5%. RESULTS: Of the 654 recruited participants 73% (n = 478) had microbial growth from both transducers applied to their left and right forearms before reprocessing. These were included in the paired noninferiority statistical analysis where, after disinfection, all CFUs were eliminated in 100% (95% CI: 99.4-100.0%) of HLD transducer samples (n = 478) and 99.0% (95% CI: 97.6-99.7%) of LLD transducer samples (n = 473). The paired difference in the proportion of transducers having all CFUs eliminated between LLD and HLD was -1.0% (95% CI: -2.4 to -0.2%, P-value <.001). CONCLUSIONS: Disinfection with LLD is noninferior to HLD when microorganisms from skin have contaminated the transducer. Therefore, using LLD for US transducers involved in percutaneous procedures would present no higher infection risk compared with HLD.

Improving difficult peripheral intravenous access requires thought, training and technology (DART3): a stepped-wedge, cluster randomised controlled trial protocol.

BACKGROUND: Peripheral intravenous catheters (PIVCs) are the most used invasive medical device in healthcare. Yet around half of insertion attempts are unsuccessful leading to delayed medical treatments and patient discomfort of harm. Ultrasound-guided PIVC (USGPIVC) insertion is an evidence-based intervention shown to improve insertion success especially in patients with Difficult IntraVenous Access (BMC Health Serv Res 22:220, 2022), however the implementation in some healthcare settings remains suboptimal. This study aims to co-design interventions that optimise ultrasound guided PIVC insertion in patients with DIVA, implement and evaluate these initiatives and develop scale up activities. METHODS: A stepped-wedge cluster randomized controlled trial will be conducted in three hospitals (two adult, one paediatric) in Queensland, Australia. The intervention will be rolled out across 12 distinct clusters (four per hospital). Intervention development will be guided by Michie's Behavior Change Wheel with the aim to increase local staff capability, opportunity, and motivation for appropriate, sustainable adoption of USGPIVC insertion. Eligible clusters include all wards or departments where > 10 PIVCs/week are typically inserted. All clusters will commence in the control (baseline) phase, then, one cluster per hospital will step up every two months, as feasible, to the implementation phase, where the intervention will be rolled out. Implementation strategies are tailored for each hospital by local investigators and advisory groups, through context assessments, staff surveys, and stakeholder interviews and informed by extensive consumer interviews and consultation. Outcome measures align with the RE-AIM framework including clinical-effectiveness outcomes (e.g., first-time PIVC insertion success for DIVA patients [primary outcome], number of insertion attempts); implementation outcomes (e.g., intervention fidelity, readiness assessment) and cost effectiveness outcomes. The Consolidated Framework for Implementation Research framework will be used to report the intervention as it was implemented; how people participated in and responded to the intervention; contextual influences and how the theory underpinning the intervention was realised and delivered at each site. A sustainability assessment will be undertaken at three- and six-months post intervention. DISCUSSION: Study findings will help define systematic solutions to implement DIVA identification and escalation tools aiming to address consumer dissatisfaction with current PIVC insertion practices. Such actionable knowledge is critical for implementation of scale-up activities. TRIAL REGISTRATION: Prospectively registered (Australian and New Zealand Clinical Trials Registry; ACTRN12621001497897).

C3/CD11b-Mediated Leishmania major Internalization by Neutrophils Induces Intraphagosomal NOX2-Mediated Respiratory Burst but Fails to Eliminate Parasites and Induces a State of Stalled Apoptosis.

Recruited neutrophils are among the first phagocytic cells to interact with the phagosomal pathogen Leishmania following inoculation into the mammalian dermis. Analysis of Leishmania-infected neutrophils has revealed alterations in neutrophil viability, suggesting that the parasite can both induce or inhibit apoptosis. In this study, we demonstrate that entry of Leishmania major into murine neutrophils is dependent on the neutrophil surface receptor CD11b (CR3/Mac-1) and is enhanced by parasite opsonization with C3. Infected neutrophils underwent robust NADPH oxidase isoform 2 (NOX2)-dependent respiratory burst based on detection of reactive oxygen species within the phagolysosome but largely failed to eliminate the metacyclic promastigote life cycle stage of the parasite. Infected neutrophils displayed an "apoptotic" phosphatidylserine (PS)-positive phenotype, which was induced by both live and fixed parasites but not latex beads, suggesting that PS expression was parasite specific but does not require active infection. In addition, neutrophils from parasite/neutrophil coculture had increased viability, decreased caspase 3, 8, and 9 gene expression, and reduced protein levels of both the pro and cleaved forms of the classical apoptosis-inducing executioner caspase, Caspase 3. Our data suggest that CD11b-mediated Leishmania internalization initiates respiratory burst and PS externalization, followed by a reduction in both the production and cleavage of caspase 3, resulting in a phenotypic state of "stalled apoptosis."

Novel approaches to preventing phagosomal infections: timing is key.

Prophylactic vaccination strategies designed to prevent diseases caused by pathogens using the phagolysosome of innate immune cells as a site of intracellular replication and survival have been largely ineffective. These include Mycobacterium tuberculosis (Mtb), Leishmania spp., and Cryptococcus spp. These failed strategies have traditionally targeted CD4+ T helper (Th) 1 cell-mediated immune memory, deeming it crucial for vaccine efficacy. This failure warrants an investigation of alternative mediators of protection. Here, we suggest three novel approaches to activate phagocytic cells prior to or at the time of infection. We hypothesize that preventing the formation of the pathogen niche within the phagolysosome is essential for preventing disease, and a greater emphasis on the timing of phagocyte activation should generate more effective prophylactic treatment options.

Remotely supervised ultrasound-guided peripheral intravenous cannulation training: A prospective cohort study examining success rates and patient experience.

Introduction: Ultrasound-guided peripheral intravenous cannulation (USGPIVC) benefits patients with difficult intravenous access (DIVA) through visualising otherwise non-visible and non-palpable veins. Supervised live-case training is an important component of learning this skill, but supervisor availability can present a barrier limiting or delaying staff completing their training. Aims: The aim of this study was to determine the first-attempt success rate of newly trained USGPIVC inserters using remote supervision and timely written feedback based on app-based screen recordings taken during insertion. Secondary aims were overall procedural success, and inserter and patient experiences. Methods: This study is an observational cohort study carried out between October and December 2021. Fourteen newly trained junior medical officers (JMOs) were eligible to utilise USGPIVC on a minimum of five consenting patients while simultaneously recording the ultrasound screen during insertion to capture their technique. Feedback was generated following expert review of these recordings against a standardised feedback tool. Results: Average first-attempt success was 71% (n = 72) in the 102 patients recruited. The average time for JMOs to receive feedback was 30 h, and 13 JMOs (93%) felt well supported and completed the remote training pathway. The majority of patients were female (n = 59; 58%), were aged 41-80 years (n = 75; 74%) and had ≥2 risk factors for DIVA (n = 57; 56%). Conclusions: First-attempt success rates were similar when comparing remote supervision used in this study to direct supervision used by other studies.This finding supports incorporating remote supervision into training guidelines for USGPIVC as an alternative method of supervision, particularly when supervisor availability is limited.

The Paradox of a Phagosomal Lifestyle: How Innate Host Cell-Leishmania amazonensis Interactions Lead to a Progressive Chronic Disease.

Intracellular phagosomal pathogens represent a formidable challenge for innate immune cells, as, paradoxically, these phagocytic cells can act as both host cells that support pathogen replication and, when properly activated, are the critical cells that mediate pathogen elimination. Infection by parasites of the Leishmania genus provides an excellent model organism to investigate this complex host-pathogen interaction. In this review we focus on the dynamics of Leishmania amazonensis infection and the host innate immune response, including the impact of the adaptive immune response on phagocytic host cell recruitment and activation. L. amazonensis infection represents an important public health problem in South America where, distinct from other Leishmania parasites, it has been associated with all three clinical forms of leishmaniasis in humans: cutaneous, muco-cutaneous and visceral. Experimental observations demonstrate that most experimental mouse strains are susceptible to L. amazonensis infection, including the C57BL/6 mouse, which is resistant to other species such as Leishmania major, Leishmania braziliensis and Leishmania infantum. In general, the CD4+ T helper (Th)1/Th2 paradigm does not sufficiently explain the progressive chronic disease established by L. amazonensis, as strong cell-mediated Th1 immunity, or a lack of Th2 immunity, does not provide protection as would be predicted. Recent findings in which the balance between Th1/Th2 immunity was found to influence permissive host cell availability via recruitment of inflammatory monocytes has also added to the complexity of the Th1/Th2 paradigm. In this review we discuss the roles played by innate cells starting from parasite recognition through to priming of the adaptive immune response. We highlight the relative importance of neutrophils, monocytes, dendritic cells and resident macrophages for the establishment and progressive nature of disease following L. amazonensis infection.

Protective CD4+ Th1 cell-mediated immunity is reliant upon execution of effector function prior to the establishment of the pathogen niche.

Intracellular infection with the parasite Leishmania major features a state of concomitant immunity in which CD4+ T helper 1 (Th1) cell-mediated immunity against reinfection coincides with a chronic but sub-clinical primary infection. In this setting, the rapidity of the Th1 response at a secondary site of challenge in the skin represents the best correlate of parasite elimination and has been associated with a reversal in Leishmania-mediated modulation of monocytic host cells. Remarkably, the degree to which Th1 cells are absolutely reliant upon the time at which they interact with infected monocytes to mediate their protective effect has not been defined. In the present work, we report that CXCR3-dependent recruitment of Ly6C+ Th1 effector (Th1EFF) cells is indispensable for concomitant immunity and acute (<4 days post-infection) Th1EFF cell-phagocyte interactions are critical to prevent the establishment of a permissive pathogen niche, as evidenced by altered recruitment, gene expression and functional capacity of innate and adaptive immune cells at the site of secondary challenge. Surprisingly, provision of Th1EFF cells after establishment of the pathogen niche, even when Th1 cells were provided in large quantities, abrogated protection, Th1EFF cell accumulation and IFN-γ production, and iNOS production by inflammatory monocytes. These findings indicate that protective Th1 immunity is critically dependent on activation of permissive phagocytic host cells by preactivated Th1EFF cells at the time of infection.

Relative Efficiency of Drag Fabrics for Collection of Blacklegged Tick (Acari: Ixodidae) Larvae, Nymphs, and Adults.

The blacklegged tick (Ixodes scapularis Say) vectors several bacterial, protozoan, and viral human pathogens. The known distribution, abundance, and phenology of I. scapularis within its estimated range are incomplete. This gap in knowledge is problematic because these factors are important for determining acarological risk of exposure to infected ticks. Consequently, enhanced surveillance of I. scapularis is being promoted and supported in the United States. Although the most common method for collecting I. scapularis is by dragging a sturdy cloth along the ground, there are no published empirical data showing which drag fabric is most effective. We used a randomized block design to directly compare the relative efficiencies of canvas, corduroy, and flannel drags for the collection of larval, nymphal, and adult I. scapularis. Overall, flannel was the most effective fabric and canvas was the least effective. Significantly more adults were collected on flannel than on canvas or corduroy, and the same number of nymphs was collected on flannel and corduroy. Significantly more larvae were collected on flannel than on canvas, but one-third of larvae could not be removed from the former fabric by lint-rolling, and handpicking was difficult. Our findings support the use of flannel drags to maximize sampling effort for collection of I. scapularis, especially adults to determine the presence of ticks and tick-borne pathogens when density and infection prevalence are low, with the caveat that detection and removal of larvae are time-consuming.

The role of dermis resident macrophages and their interaction with neutrophils in the early establishment of Leishmania major infection transmitted by sand fly bite.

There is substantial experimental evidence to indicate that Leishmania infections that are transmitted naturally by the bites of infected sand flies differ in fundamental ways from those initiated by needle inocula. We have used flow cytometry and intravital microscopy (IVM) to reveal the heterogeneity of sand fly transmission sites with respect to the subsets of phagocytes in the skin that harbor L. major within the first hours and days after infection. By flow cytometry analysis, dermis resident macrophages (TRMs) were on average the predominant infected cell type at 1 hr and 24 hr. By confocal IVM, the co-localization of L. major and neutrophils varied depending on the proximity of deposited parasites to the presumed site of vascular damage, defined by the highly localized swarming of neutrophils. Some of the dermal TRMs could be visualized acquiring their infections via transfer from or efferocytosis of parasitized neutrophils, providing direct evidence for the "Trojan Horse" model. The role of neutrophil engulfment by dermal TRMs and the involvement of the Tyro3/Axl/Mertk family of receptor tyrosine kinases in these interactions and in sustaining the anti-inflammatory program of dermal TRMs was supported by the effects observed in neutrophil depleted and in Axl-/-Mertk-/- mice. The Axl-/-Mertk-/- mice also displayed reduced parasite burdens but more severe pathology following L. major infection transmitted by sand fly bite.

Th1-Th2 Cross-Regulation Controls Early Leishmania Infection in the Skin by Modulating the Size of the Permissive Monocytic Host Cell Reservoir.

The impact of T helper (Th) 1 versus Th2 immunity on intracellular infections is attributed to classical versus alternative activation of macrophages leading to resistance or susceptibility. However, observations in multiple infectious settings demonstrate deficiencies in mediators of Th1-Th2 immunity, which have paradoxical or no impact. We report that prior to influencing activation, Th1/Th2 immunity first controls the size of the permissive host cell reservoir. During early Leishmania infection of the skin, IFN-γ- or STAT6-mediated changes in phagocyte activation were counteracted by changes in IFN-γ-mediated recruitment of permissive CCR2+ monocytes. Monocytes were required for early parasite expansion and acquired an alternatively activated phenotype despite the Th1 dermal environment required for their recruitment. Surprisingly, STAT6 did not enhance intracellular parasite proliferation, but rather modulated the size and permissiveness of the monocytic host cell reservoir via regulation of IFN-γ and IL-10. These observations expand our understanding of the Th1-Th2 paradigm during infection.

Investigating Socioeconomic Disparities in the Potential Healthy Eating and Physical Activity Environments of Churches.

Faith-based settings have the potential to improve health in underresourced communities, but little research has quantified and compared health-promoting elements in church environments. This study examines the number of potential indoor and outdoor physical activity opportunities, healthy eating opportunities, healthy living media, and total environmental resources present in churches (n = 54) in a rural, southeastern US county and the relationship between these resources and neighborhood income. In our sample, most churches offered potential indoor and outdoor opportunities for physical activity and healthy eating opportunities, with more variability in the number of healthy living media items on display compared to other environmental components. Common potential opportunities present in churches for physical activity included a fellowship hall and green/open space, while potential opportunities for healthy eating frequently included a refrigerator and sink. Compared to those in medium- and high-income neighborhoods, churches in low-income neighborhoods scored higher on measures of potential outdoor physical activity opportunities and lower on measures of total potential environment resources, healthy eating opportunities, healthy living media, and indoor physical activity opportunities, though only indoor physical activity opportunities reached statistical significance. Potential opportunities for using existing resources in and around churches for health promotion should be investigated further, particularly in rural areas.

Loop-mediated isothermal amplification (LAMP): An advanced molecular point-of-care technique for the detection of Leishmania infection.

Leishmaniasis, caused by protozoan parasites of the Leishmania genus, represents an important health problem in many regions of the world. Lack of effective point-of-care (POC) diagnostic tests applicable in resources-limited endemic areas is a critical barrier to effective treatment and control of leishmaniasis. The development of the loop-mediated isothermal amplification (LAMP) assay has provided a new tool towards the development of a POC diagnostic test based on the amplification of pathogen DNA. LAMP does not require a thermocycler, is relatively inexpensive, and is simple to perform with high amplification sensitivity and specificity. In this review, we discuss the current technical developments, applications, diagnostic performance, challenges, and future of LAMP for molecular diagnosis and surveillance of Leishmania parasites. Studies employing the LAMP assay to diagnose human leishmaniasis have reported sensitivities of 80% to 100% and specificities of 94% to 100%. These observations suggest that LAMP offers a good molecular POC technique for the diagnosis of leishmaniasis and is also readily applicable to screening at-risk populations and vector sand flies for Leishmania infection in endemic areas.

CD4+ T Cell-Mediated Immunity against the Phagosomal Pathogen Leishmania: Implications for Vaccination.

The generation of an efficacious vaccine that elicits protective CD4+ T cell-mediated immunity has been elusive. The lack of a vaccine against the Leishmania parasite is particularly perplexing as infected individuals acquire life-long immunity to reinfection. Experimental observations suggest that the relationship between immunological memory and protection against Leishmania is not straightforward and that a new paradigm is required to inform vaccine design. These observations include: (i) induction of Th1 memory is a component of protective immunity, but is not sufficient; (ii) memory T cells may be protective only if they generate circulating effector cells prior to, not after, challenge; and (iii) the low-dose/high-inflammation conditions of physiological vector transmission compromises vaccine efficacy. Understanding the implications of these observations is likely key to efficacious vaccination.

Big Data to the Bench: Transcriptome Analysis for Undergraduates.

Next-generation sequencing (NGS)-based methods are revolutionizing biology. Their prevalence requires biologists to be increasingly knowledgeable about computational methods to manage the enormous scale of data. As such, early introduction to NGS analysis and conceptual connection to wet-lab experiments is crucial for training young scientists. However, significant challenges impede the introduction of these methods into the undergraduate classroom, including the need for specialized computer programs and knowledge of computer coding. Here, we describe a semester-long, course-based undergraduate research experience at a liberal arts college combining RNA-sequencing (RNA-seq) analysis with student-driven, wet-lab experiments to investigate plant responses to light. Students derived hypotheses based on analysis of RNA-seq data and designed follow-up studies of gene expression and plant growth. Our assessments indicate that students acquired knowledge of big data analysis and computer coding; however, earlier exposure to computational methods may be beneficial. Our course requires minimal prior knowledge of plant biology, is easy to replicate, and can be modified to a shorter, directed-inquiry module. This framework promotes exploration of the links between gene expression and phenotype using examples that are clear and tractable and improves computational skills and bioinformatics self-efficacy to prepare students for the "big data" era of modern biology.

Barriers to resistance training among college-aged women.

OBJECTIVE: To examine resistance training (RT) barriers among college-aged women. PARTICIPANTS: Female college students (n = 223) from a Midwestern university. METHODS: Data were collected in September 2014. Participants completed a survey assessing demographics, current and past RT habits, and barriers to resistance training. Descriptive statistics were used to examine barrier agreement. Differences between current and past RT participation, residency, and class standing were analyzed. RESULTS: A majority of participants were Caucasian (78.9%) and, on average, 19.7 ± 1.5 years of age; 52% participated in RT and 46.6% met RT recommendations. Women who did not report current RT participation reported significantly higher mean agreement with all barriers, compared to those who do RT. Highest agreement was observed within socially based barriers. CONCLUSION: A majority of college-aged women are not meeting RT recommendations. Providing educational programs and avenues for finding same-sex RT partners may be most beneficial for overcoming common RT barriers.

Comparison of learning outcomes for teaching focused cardiac ultrasound to physicians: A supervised human model course versus an eLearning guided self- directed simulator course.

PURPOSE: Focused cardiac ultrasound (FCU) training in critical care is restricted by availability of instructors. Supervised training may be substituted by self-directed learning with an ultrasound simulator guided by automated electronic learning, enabling scalability. MATERIALS AND METHODS: We prospectively compared learning outcomes in novice critical care physicians after completion of a supervised one-and-a-half-day workshop model with a self-guided course utilizing a simulator over four weeks. Both groups had identical pre-workshop on-line learning (20h). Image quality scores were compared using FCU performed on humans without pathology. Interpretive knowledge was compared using 20MCQ tests. RESULTS: Of 161 eligible, 145 participants consented. Total Image quality scores were higher in the Simulator group (95.2% vs. 66.0%, P < .001) and also higher for each view (all P < .001). Interpretive knowledge was not different before (78.6% vs. 79.0%) and after practical training (74.7% vs. 76.1%) and at 3 months (81.0% vs. 77.0%, all P > .1). Including purchase of the simulator and ultrasound equipment, the simulator course required lower direct costs (AUD$796 vs. $1724 per participant) and instructor time (0.5 vs.1.5 days) but similar participant time (2.8 vs. 3.0 days). CONCLUSIONS: Self-directed learning with ultrasound simulators may be a scalable alternative to conventional supervised teaching with human models.