Detection of rat lungworm (Angiostrongylus cantonensis) infection by real-time PCR from the peripheral blood of animals: a preliminary study.

Rat lungworm disease or neuroangiostrongyliasis is a cerebral parasitic infection that affects humans and animals alike. Its clinical signs and symptoms can range from mild self-resolving to serious life-threatening conditions. Studies suggest therapeutic interventions during the early stages of infection to be more effective than in later stages. However, early diagnosis of infection is usually problematic without the knowledge of exposure and/or detection of the parasite's DNA or antibody against the parasite in the cerebrospinal fluid. This requires a lumbar puncture, which is an invasive procedure that generally requires hospitalization. This study evaluates an affordable and less invasive alternative to detect parasitic DNA by PCR from the peripheral blood of potentially infected animals. Blood samples from 58 animals (55 dogs and 3 cats) with clinical suspicion of infection were submitted to our lab between February 2019 and August 2022 by local, licensed veterinarians. DNA was extracted from whole blood, plasma, serum, and/or packed cells using the Qiagen DNeasy Blood & Tissue Kit as per the manufacturer's protocol. All 58 animals were tested by real-time PCR using the AcanITS1 assay and 32 of these animals (31dogs; 1 cat) were also tested using the AcanR3990 assay. The PCR results for both assays were classified into strongly positive > positive > weakly positive > negative, and equivocal for ambiguous results, based on the strength of the signal. The percent infection detected using the AcanITS1 and AcanR3990 assays was 12.72% (7/55) and 20.68% (6/29), respectively. The overall percent infection detected was 34.37% (11/32), with only two animals testing positive by both assays. The three cats involved in this study tested negative by both assays. These results are promising and warrant further investigations to increase sensitivity including variables that might affect detection in the blood, such as parasite load, and laboratory methodologies.

Early dose of Adenosine, postRadiofrequency abLation of accessory pathwaY in determining acute procedural success (EARLY study).

INTRODUCTION: Post ablation of the accessory pathway (AP), the patient is observed in the catheterization laboratory for a variable period for resumption of pathway conduction. Aim of the study was to determine whether the administration of intravenous adenosine at 10 min after ablation of AP would have the same diagnostic accuracy as waiting for 30 min in predicting the resumption of AP conduction. METHODS: This was a prospective interventional study conducted in two centers. Post ablation of the AP, intravenous adenosine was administered at 10 min to look for dormant pathway conduction. The response was recorded as positive (presence of pathway conduction), negative (absence), or indeterminate (not able to demonstrate AV and VA block and inability to ascertain AP conduction). RESULTS: The study included 110 procedures performed in 109 patients. Adenosine administration at 10 min showed positive result in 3 cases (2.7%), negative result in 99 cases (90%) and indeterminate result in 8 cases (7.3%). Reconnection of accessory pathway at 30 min postablation was seen in 8 cases (7.3%). Of these 8 cases, 10 min adenosine administration showed positive test in 3 patients and negative test in 5 patients. Adenosine test at 10 min has a sensitivity, specificity, positive predictive value, and negative predictive value of 37.5%, 100%, 100%, and 94.9% in identifying the recurrence of accessory pathway conduction at 30 min, respectively. CONCLUSION: Absence of pathway conduction on administration of adenosine 10 min postablation does not help predict the absence of resumption of conduction thereafter.

Deconstructing cerebellar development cell by cell.

The cerebellum is a pivotal centre for the integration and processing of motor and sensory information. Its extended development into the postnatal period makes this structure vulnerable to a variety of pathologies, including neoplasia. These properties have prompted intensive investigations that reveal not only developmental mechanisms in common with other regions of the neuraxis but also unique strategies to generate neuronal diversity. How the phenotypically distinct cell types of the cerebellum emerge rests on understanding how gene expression differences arise in a spatially and temporally coordinated manner from initially homogeneous cell populations. Increasingly sophisticated fate mapping approaches, culminating in genetic-induced fate mapping, have furthered the understanding of lineage relationships between early- versus later-born cells. Tracing the developmental histories of cells in this way coupled with analysis of gene expression patterns has provided insight into the developmental genetic programmes that instruct cellular heterogeneity. A limitation to date has been the bulk analysis of cells, which blurs lineage relationships and obscures gene expression differences between cells that underpin the cellular taxonomy of the cerebellum. This review emphasises recent discoveries, focusing mainly on single-cell sequencing in mouse and parallel human studies that elucidate neural progenitor developmental trajectories with unprecedented resolution. Complementary functional studies of neural repair after cerebellar injury are challenging assumptions about the stability of postnatal cellular identities. The result is a wealth of new information about the developmental mechanisms that generate cerebellar neural diversity, with implications for human evolution.

Electrocardiographic lead reversals.

Misplacement of cables during the recording of a 12-lead electrocardiogram [ECG] poses a non-negligible risk of creating panic and confusion at the bedside in daily clinical practice. Clinical awareness about the manifestations of commonly encountered electrode misplacements is imperative for avoiding misdiagnosis. A basic understanding of the electrophysiology behind these anomalous ECG tracings is likely to aid in prompt suspicion, accurate detection, and appropriate rectification in most cases. We discuss the abnormalities produced on 12-lead ECG tracings by the misplacement of electrode cables, with a focus on the clinical implications of the same. We suggest a mnemonic - 'SPIRAL' - as a quick screening criterion to detect commonly encountered lead reversals.

Clinical Efficacy and Safety of Albendazole and Other Benzimidazole Anthelmintics for Rat Lungworm Disease (Neuroangiostrongyliasis): A Systematic Analysis of Clinical Reports and Animal Studies.

The safety and efficacy of benzimidazole anthelmintics for the treatment of rat lungworm disease (neuroangiostrongyliasis) have been questioned regardless of numerous experimental animal studies and clinical reports. In this review, 40 of these experimental animal studies and 104 clinical reports are compiled with a focus on albendazole. Among the 144 articles involving an estimated 1034 patients and 2561 animals, 4.1% were inconclusive or vague regarding the use of benzimidazoles. Of the remaining 138 articles, 90.5% found benzimidazoles to be safe and effective (885 patients, 2530 animals), 4.3% as safe but ineffective (73 patients, 3 animals), and 5.0% caused adverse reactions (7 patients, 28 animals). Among those clinical reports that described a confirmed diagnosis of neuroangiostrongyliasis in which albendazole monotherapy was used, 100% reported high efficacy (743 patients, 479 animals). In those where albendazole-corticosteroid co-therapy was used, 97.87% reported it to be effective (323 patients, 130 animals).

Evaluation of the mechanism of action of albendazole on adult rat lungworm (Angiostrongyluscantonensis).

Albendazole is considered the anthelmintic of choice for the management of rat lungworm disease (neuroangiostrongyliasis), due to its broad spectrum of nematocidal activity and its ability to cross the blood-brain barrier. Albendazole binds to ß-tubulins, preventing their polymerization into microtubules, thereby corrupting the cascade of cell division at metaphase, which ultimately leads to the death of individual cells and eventually the death of the parasite. Inhibition of microtubule formation will also hinder the axoplasmic transport system, affecting the neuronal activities of the parasite. While this mechanism has been explicated in other parasitic and non-parasitic nematodes, it has never been evaluated in Angiostrongylus cantonensis. This study evaluates the antimitotic effects of albendazole sulphoxide (active metabolite) on the microtubules of adult A. cantonensis using the tubulin polymerization assay and measures its effects on worm viability using the colorimetric MTT assay. Three different concentrations of albendazole (62.5 µM, 250 µΜ, and 1 mM) were evaluated. We saw a statistically significant dose-dependent reduction in the band intensity of polymerized tubulins (or microtubules) (P = 0.019), suggesting that albendazole imparts its antimitotic effect in a dose-dependent manner. Similarly, our MTT assay showed a dose-dependent decrease in formazan intensity (proportional to cell viability), suggesting that the rate of nematocidal activity of albendazole is also proportional to its concentration. In compiling the results from both these experiments, a correlation between the microtubule assembly and worm viability is evident.

Evaluation of the Web-Based OutsidePlay-ECE Intervention to Influence Early Childhood Educators' Attitudes and Supportive Behaviors Toward Outdoor Play: Randomized Controlled Trial.

BACKGROUND: Outdoor play is critical to children's healthy development and well-being. Early learning and childcare centers (ELCCs) are important venues for increasing children's outdoor play opportunities, and early childhood educators' (ECE) perception of outdoor play can be a major barrier to outdoor play. The OutsidePlay-ECE risk-reframing intervention is a fully automated and open access web-based intervention to reframe ECEs' perceptions of the importance of outdoor play and risk in play and to promote a change in their practice in supporting it in ELCC settings. We grounded the intervention in social cognitive theory and behavior change techniques. OBJECTIVE: The aim of this study is to evaluate the effectiveness of the OutsidePlay-ECE web-based risk-reframing intervention. METHODS: We conducted a single-blind randomized controlled trial in Canada between December 2020 and June 2021 to test the OutsidePlay-ECE risk-reframing intervention for ECEs. We recruited participants using social media and mass emails through our partner and professional networks. We invited ECEs and administrators working in an ELCC, who can speak, read, and understand English. We randomized consented participants to the intervention or control condition. The participants allocated to the intervention condition received a link to the OutsidePlay-ECE intervention. Participants allocated to the control condition read the Position Statement on Active Outdoor Play, a 4-page document on research and recommendations for action in addressing barriers to outdoor play. The primary outcome was a change in tolerance of risk in play. The secondary outcome was goal attainment. We collected data on the web via REDCap (Vanderbilt University) at baseline and 1 week and 3 months after intervention. RESULTS: A total of 563 participants completed the baseline survey, which assessed their demographics and tolerance of risk in play. They were then randomized: 281 (49.9%) to the intervention and 282 (50.1%) to the control condition. Of these, 136 (48.4%) and 220 (78%) participants completed the baseline requirements for the intervention and control conditions, respectively. At 1 week after intervention, 126 (44.8%) and 209 (74.1%) participants completed follow-up assessments, respectively, and at 3 months after intervention, 119 (42.3%) and 195 (69.1%) participants completed the assessments, respectively. Compared with participants in the control condition, participants in the intervention group had significantly higher tolerance of risk in play at 1 week (ß=.320; P=.001) and 3 months after intervention (ß=.251; P=.009). Intention-to-treat analyses replicated these findings (ß=.335; P<.001 and ß=.271; P=.004, respectively). No significant intervention effect was found for goal attainment outcomes (odds ratio 1.124, 95% CI 0.335-3.774; P=.85). CONCLUSIONS: The results of this randomized controlled trial demonstrated that the OutsidePlay-ECE intervention was effective and had a sustained effect in increasing ECEs' and administrators' tolerance of risk in play. It was not effective in increasing goal attainment. TRIAL REGISTRATION: ClinicalTrials.gov NCT04624932; https://clinicaltrials.gov/ct2/show/NCT04624932. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/31041.

Recent advances in nanotechnology for remediation of heavy metals.

Heavy metal contamination of the environment has become an alarming environmental issue that has constituted serious threats to humans and the ecosystem. These metals have been identified as a priority class of pollutants due to their persistency in the environment and their potential to bioaccumulate in biological systems. Consequently, the remediation of heavy metals from various environmental matrices becomes a critical topic from the biological and environmental perspectives. To this end, various research interests have shifted to the need to put forward economically feasible and highly efficient approaches for mitigating these contaminants in the environment. Thus, numerous conventional approaches have reportedly been employed for the remediation of heavy metals, with each of the methods having its inherent limitations. More recently, studies have revealed that nanomaterials in their various forms show unique potential for the removal of various contaminants including heavy metals in comparison to their bulk counterparts making them a topic of importance to researchers in various fields. Also, various studies have documented specifically tailored nanomaterials that have been synthesized for the removal of heavy metals from various environmental matrices. This review provides up-to-date information on the application of nanotechnology for the remediation of heavy metals. It highlights various nanomaterials that have been employed for the remediation of heavy metals, current details on their methods of synthesis, factors affecting their adsorption processes, and the environmental and health impact of nanomaterials. Finally, it provides the challenges and future trends of nanomaterials for heavy metal removal.

In vitro efficacy of anthelmintics on Angiostrongylus cantonensis L3 larvae.

Angiostrongylus cantonensis is the leading cause of eosinophilic meningitis worldwide, with life-threatening complications if not managed correctly. Previous in vitro studies have utilized change in motility patterns of adult female worms to assess the efficacy of anthelmintics qualitatively. However, it is the third stage larvae (L3) that are infectious to humans. With differential staining using propidium iodide penetration as the indicator of death, we can distinguish between dead and live larvae. This assay has enabled us to quantify the in vitro efficacy of nine clinically established anthelmintics on A. cantonensis L3. All drugs were tested at a 1 mm concentration. Piperazine and niclosamide were ineffective in inducing larval death; however, albendazole sulfoxide, pyrantel pamoate, diethylcarbamazine, levamisole and praziquantel were effective as compared to unexposed controls (P < 0.05). Ivermectin and moxidectin did not induce significant levels of mortality, but they considerably reduced larval motility almost immediately. This study indicates the need for further in vivo studies to determine the optimal dose and time frame for post-infection treatment with anthelmintics that demonstrated efficacy.

Demographics of the semi-slug Parmarion martensi, an intermediate host for Angiostrongylus cantonensis in Hawai'i, during laboratory rearing.

The semi-slug, Parmarion martensi, is an intermediate host of the zoonotic nematode, Angiostrongylus cantonensis, the aetiological agent of neuroangiostrongyliasis or rat lungworm disease in humans. Rearing methods were developed for P. martensi to facilitate studies on nematode transmission and control. Parmarion martensi exhibited high survivorship when reared on a diet of dog food and fresh fruits and vegetables in temperature-controlled cabinets at 21.4°C, 98% relative humidity and 12:12 L:D cycle. Rearing containers were lined with moist paper towels for substrate and plastic pots were provided for hiding/resting and egg-laying. Under these conditions, time to first reproduction was 165.3 ± 12.3 days, fecundity was approximately 34.5 ± 7.8 eggs per adult, and hatch rate was 52.7 ± 3.2%. Survivorship post egg hatch was 86.2 ± 2.9% at 30 days (neonates had a mortality rate of about 14%) and 99% thereafter for up to a year. The demographics of laboratory-reared and wild-caught P. martensi were similar except for the weight of reproductive adults, which was significantly higher in laboratory-reared adults (4.0 ± 0.2 g) than in field-collected adults (1.5 ± 0.1 g).

In vitro comparison of treatments and commercially available solutions on mortality of Angiostrongylus cantonensis third-stage larvae.

On Hawai'i Island, an increase in human neuroangiostrongyliasis cases has been primarily associated with the accidental ingestion of Angiostrongylus cantonensis L3 in snails or slugs, or potentially, from larvae left behind in the slug's slime or feces. We evaluated more than 40 different treatments in vitro for their ability to kill A. cantonensis larvae with the goal of identifying a safe and effective fruit and vegetable wash in order to reduce the risk of exposure. Our evaluation of treatment lethality was carried out in two phases; initially using motility as an indicator of larval survival after treatment, followed by the development and application of a propidium iodide staining assay to document larval mortality. Treatments tested included common household products, consumer vegetable washes and agricultural crop washes. We found minimal larvicidal efficacy among consumer-grade fruit and vegetable washes, nor among botanical extracts such as those from ginger or garlic, nor acid solutions such as vinegar. Alkaline solutions, on the other hand, as well as oxidizers such as bleach and chlorine dioxide, did show larvicidal potential. Surfactants, a frequent ingredient in detergents that lowers surface tension, had variable results, but dodecylbenzene sulfonic acid as a 70% w/w solution in 2-propanol was very effective, both in terms of the speed and the thoroughness with which it killed A. cantonensis L3 nematodes. Thus, our results suggest promising directions for future investigation.

Comparing a Virtual Reality-Based Simulation App (VR-MRI) With a Standard Preparatory Manual and Child Life Program for Improving Success and Reducing Anxiety During Pediatric Medical Imaging: Randomized Clinical Trial.

BACKGROUND: The experience of undergoing magnetic resonance imaging (MRI) can be anxiety provoking, particularly for pediatric patients and their families. Alternative methods to improve success and experiences without the use of sedation are needed. OBJECTIVE: This study aims to compare the effectiveness of a virtual reality (VR)-based simulation app (VR-MRI) with a standard preparatory manual (SPM) and a hospital-based Child Life Program (CLP) on success and anxiety during a simulated pediatric MRI scan. Our secondary aim is to compare caregivers' reported anxiety, procedural data, caregiver usability, child satisfaction, and fun. METHODS: This unblinded, randomized, triple-arm clinical trial involved 92 children aged 4-13 years and their caregivers. Recruitment was conducted through posters, public libraries, community centers, and social media. At a 2-hour session, participants were instructed to prepare for a simulated MRI head scan using one of three randomly assigned preparation materials: the VR-MRI app, SPM, or the CLP. Data were collected before preparation, during a simulated MRI head scan, and after the simulated scan. The primary outcomes were the success of the simulated MRI scan (MoTrak head motion tracking system), and child-reported anxiety (Venham picture test). We secondarily measured caregivers' reported anxiety (short State-Trait Anxiety Inventory), procedural data (minutes), usability (Usefulness, Satisfaction, and Ease of Use Questionnaire), and child-reported satisfaction and fun (visual analog scales). RESULTS: A total of 84 participants were included in the final analysis (VR-MRI: 30/84, 36%; SPM: 24/84, 29%; and CLP: 30/84, 36%). There were no clinically significant differences between the groups in terms of success during the MRI simulation (P=.27) or the children's reported anxiety at any timepoint (timepoint 1, P=.99; timepoint 2, P=.008; timepoint 3, P=.10). Caregivers reported being significantly more anxious after preparing with the manual than caregivers in the other 2 groups (P<.001). Child and caregiver anxiety had a significant relationship, increasing together with moderate effect (r84=0.421; P<.001). Participants using VR-MRI took the most time to prepare (P<.001) and participants using the manual took the least time (P<.001). No statistically significant relationships were found between time preparing and time completing the simulated assessment (P=.13). There were no differences found in ease of use (P=.99), ease of learning (P=.48), and usefulness (P=.11) between the groups; however, caregivers reported being significantly more satisfied with the VR-MRI app and CLP than SPM (P<.001). Children reported the most satisfaction with the CLP (P<.001). There were no differences in how much fun the preparation materials were perceived to be (P=.37). CONCLUSIONS: Digital preparation experiences using VR-based media could be a viable solution to improve the success of nonsedated MRI scans, with outcomes comparable with hospital-based in-person preparatory programs. Future research should focus on validating the results in a real MRI setting. TRIAL REGISTRATION: Clinicaltrials.gov NCT03931382; https://clinicaltrials.gov/ct2/show/NCT03931382.

A Web-Based and In-Person Risk Reframing Intervention to Influence Mothers' Tolerance for, and Parenting Practices Associated With, Children's Outdoor Risky Play: Randomized Controlled Trial.

BACKGROUND: Outdoor risky play, such as climbing, racing, and independent exploration, is an important part of childhood and is associated with various positive physical, mental, and developmental outcomes for children. Parental attitudes and fears, particularly mothers', are a major deterrent to children's opportunities for outdoor risky play. OBJECTIVE: The aim of this study was to evaluate the efficacy of 2 versions of an intervention to reframe mothers' perceptions of risk and change parenting behaviors: a web-based intervention or an in-person workshop, compared with the control condition. METHODS: The Go Play Outside! randomized controlled trial was conducted in Canada from 2017 to 2018. Participants were recruited through social media, snowball sampling, and community notices. Mothers of children aged 6-12 years were self-assessed through eligibility questions, and those eligible and consented to participate in the study were randomized into a fully automated web-based intervention, the in-person workshop, or the control condition. The intervention was underpinned by social cognitive theory, incorporating behavior change techniques. Participants progressed through a series of self-reflection exercises and developed a goal for change. Control participants received the Position Statement on Active Outdoor Play. The primary outcome was increase in tolerance of risky play and the secondary outcome was goal attainment. Data were collected online via REDCap at baseline, 1 week, and 3 months after the intervention. Randomization was conducted using sealed envelope. Allocations were concealed to researchers at assignment and data analysis. We conducted mediation analyses to examine whether the intervention influenced elements of social cognitive theory, as hypothesized. RESULTS: A total of 451 mothers were randomized and completed baseline sociodemographic assessments: 150 in the web-based intervention, 153 in the in-person workshop, and 148 in the control condition. Among these, a total of 351 mothers completed the intervention. At 1 week after the intervention, 113, 85, and 135 mothers completed assessments for each condition, respectively, and at 3 months after the intervention, 105, 84, and 123 completed the assessments, respectively. Compared with mothers in the control condition, mothers in the web-based intervention had significantly higher tolerance of risky play at 1 week (P=.004) and 3 months after the intervention (P=.007); and mothers in the in-person workshop had significantly higher tolerance of risky play at 1 week after the intervention (P=.02). No other significant outcomes were found. None of the potential mediators were found to significantly mediate the outcomes. CONCLUSIONS: The trial demonstrates that the web-based intervention was effective in increasing mothers' tolerance for risk in play. TRIAL REGISTRATION: ClinicalTrials.gov NCT03374683; https://clinicaltrials.gov/ct2/show/NCT03374683. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s13063-018-2552-4.

Validation of a death assay for Angiostrongylus cantonensis larvae (L3) using propidium iodide in a rat model (Rattus norvegicus).

Angiostrongylus cantonensis is a pathogenic nematode and the cause of neuroangiostrongyliasis, an eosinophilic meningitis more commonly known as rat lungworm disease. Transmission is thought to be primarily due to ingestion of infective third stage larvae (L3) in gastropods, on produce, or in contaminated water. The gold standard to determine the effects of physical and chemical treatments on the infectivity of A. cantonensis L3 larvae is to infect rodents with treated L3 larvae and monitor for infection, but animal studies are laborious and expensive and also raise ethical concerns. This study demonstrates propidium iodide (PI) to be a reliable marker of parasite death and loss of infective potential without adversely affecting the development and future reproduction of live A. cantonensis larvae. PI staining allows evaluation of the efficacy of test substances in vitro, an improvement upon the use of lack of motility as an indicator of death. Some potential applications of this assay include determining the effectiveness of various anthelmintics, vegetable washes, electromagnetic radiation and other treatments intended to kill larvae in the prevention and treatment of neuroangiostrongyliasis.

'Active & Safe Central': development of an online resource for the prevention of injury in sport and recreational activity.

BACKGROUND: Sport and recreation related injuries exert a significant cost on the healthcare system. As prevention researchers and practitioners, we have a responsibility to provide guidance towards prevention to those who participate in sport and recreation, and those that coach, treat and parent children that participate. The objective of this project was to use an integrated knowledge translation approach to develop an end user-driven digital platform that provides injury prevention information and resources across 51 sport and recreational activities. DESIGN: We used an integrated knowledge translation approach to scope and develop an online sport and recreational injury prevention resource. A project team was formed that included end users-coaches, parents and athletes, injury researchers and practitioners, as well as members of a digital design team. All members of the project team informed the development process, including a review of literature and existing resources, the translation of evidence and development of the platform. At all stages of development, members of the project team cocreated knowledge for the tool, including forming the research questions, the approach, feasibility and development of outcomes. CONCLUSION: The 'Active & Safe Central' (https://activesafe.ca/) platform provides web-based sport injury and prevention information. This user-friendly, web and mobile accessible platform can increase the reach, awareness and implementation of prevention programming in sport and recreational activity.

Comparative Analysis of Dentinal Crack Formation Following Root Canal Instrumentation with Hand K-Flex Files, ProTaper Next, and Self-adjusting Files.

AIM: To evaluate and compare in vitro the dentinal crack formation in root canal dentin after root canal instrumentation with hand K-Flex files, ProTaper Next, and self-adjusting engine-driven files. MATERIALS AND METHODS: Ninety-two human mandibular first molar teeth were randomly divided into four groups (n = 23) as per the instrumentation protocol: group I-unprepared teeth (control); group II-hand K-Flex files (Sybron Endo); group III-ProTaper Next X1 and X2 (Dentsply Maillefer); group IV-self-adjusting file (ReDent Nova, Israel). All the roots were sectioned perpendicular to the long axis of the tooth at 9 mm, 6 mm, and 3 mm from the apex and thereby obtaining sixty-nine samples, which were then subjected to a stereomicroscopic examination for detection of dentinal cracks. Statistical analyses were done using the Chi-square test with SPSS (version 19), and p value was set at p < 0.05. RESULTS: Statistically significant differences were seen between the instrumented groups. No dentinal cracks were found in the unprepared roots and those prepared with hand K-Flex files (0/23). Self-adjusting-file-instrumented group showed significantly less incidence of crack formation when compared to the ProTaper Next group with p = 0.001. CONCLUSION: Self-adjusting file is an efficient engine-driven NiTi instrument for root canal instrumentation with the least occurrence of crack formation in the root canal dentin compared to the ProTaper Next system. CLINICAL SIGNIFICANCE: The introduction of NiTi rotary file systems has metamorphosed the endodontic treatment by their better cutting efficiency and cleaning potentiality. Yet, evidenced-based clinical studies are to be conducted on the incidence of microfractures that can lead to vertical root fractures, which will be produced irrespective of the motion kinematics and design feature and thereby compromising the clinical maintenance of the endodontically treated teeth.

Reduced cholesterol levels impair Smoothened activation in Smith-Lemli-Opitz syndrome.

Smith-Lemli-Opitz syndrome (SLOS) is a common autosomal-recessive disorder that results from mutations in the gene encoding the cholesterol biosynthetic enzyme 7-dehydrocholesterol reductase (DHCR7). Impaired DHCR7 function is associated with a spectrum of congenital malformations, intellectual impairment, epileptiform activity and autism spectrum disorder. Biochemically, there is a deficit in cholesterol and an accumulation of its metabolic precursor 7-dehydrocholesterol (7DHC) in developing tissues. Morphological abnormalities in SLOS resemble those seen in congenital Sonic Hedgehog (SHH)-deficient conditions, leading to the proposal that the pathogenesis of SLOS is mediated by aberrant SHH signalling. SHH signalling is transduced through the transmembrane protein Smoothened (SMO), which localizes to the primary cilium of a cell on activation and is both positively and negatively regulated by sterol molecules derived from cholesterol biosynthesis. One proposed mechanism of SLOS involves SMO dysregulation by altered sterol levels, but the salient sterol species has not been identified. Here, we clarify the relationship between disrupted cholesterol metabolism and reduced SHH signalling in SLOS by modelling the disorder in vitro. Our results indicate that a deficit in cholesterol, as opposed to an accumulation of 7DHC, impairs SMO activation and its localization to the primary cilium.

Lipid metabolism fattens up hedgehog signaling.

Signaling pathways direct organogenesis, often through concentration-dependent effects on cells. The hedgehog pathway enables cells to sense and respond to hedgehog ligands, of which the best studied is sonic hedgehog. Hedgehog signaling is essential for development, proliferation, and stem cell maintenance, and it is a driver of certain cancers. Lipid metabolism has a profound influence on both hedgehog signal transduction and the properties of the ligands themselves, leading to changes in the strength of hedgehog signaling and cellular functions. Here we review the evolving understanding of the relationship between lipids and hedgehog signaling.