The many lives of KATs - detectors, integrators and modulators of the cellular environment.

Research over the past three decades has firmly established lysine acetyltransferases (KATs) as central players in regulating transcription. Recent advances in genomic sequencing, metabolomics, animal models and mass spectrometry technologies have uncovered unexpected new roles for KATs at the nexus between the environment and transcriptional regulation. Thousands of reversible acetylation sites have been mapped in the proteome that respond dynamically to the cellular milieu and maintain major processes such as metabolism, autophagy and stress response. Concurrently, researchers are continuously uncovering how deregulation of KAT activity drives disease, including cancer and developmental syndromes characterized by severe intellectual disability. These novel findings are reshaping our view of KATs away from mere modulators of chromatin to detectors of the cellular environment and integrators of diverse signalling pathways with the ability to modify cellular phenotype.

Leptin treatment has vasculo-protective effects in lipodystrophic mice.

Lipodystrophy syndromes (LDs) are characterized by loss of adipose tissue, metabolic complications such as dyslipidemia, insulin resistance, and fatty liver disease, as well as accelerated atherosclerosis. As a result of adipose tissue deficiency, the systemic concentration of the adipokine leptin is reduced. A current promising therapeutic option for patients with LD is treatment with recombinant leptin (metreleptin), resulting in reduced risk of mortality. Here, we investigate the effects of leptin on endothelial to mesenchymal transition (EndMT), which impair the functional properties of endothelial cells and promotes atherogenesis in LD. Leptin treatment reduced inflammation and TGF-ß2-induced expression of mesenchymal genes and prevented impairment of endothelial barrier function. Treatment of lipodystrophic- and atherosclerosis-prone animals (Ldlr-/-; aP2-nSrebp1c-Tg) with leptin reduced macrophage accumulation in atherosclerotic lesions, vascular plaque protrusion, and the number of endothelial cells with mesenchymal gene expression, confirming a reduction in EndMT in LD after leptin treatment. Treatment with leptin inhibited LD-mediated induction of the proatherosclerotic cytokine growth/differentiation factor 15 (GDF15). Inhibition of GDF15 reduced EndMT induction triggered by plasma from patients with LD. Our study reveals that in addition to the effects on adipose tissue function, leptin treatment exerts beneficial effects protecting endothelial function and identity in LD by reducing GDF15.

Inhibitors of histone acetyltransferases KAT6A/B induce senescence and arrest tumour growth.

Acetylation of histones by lysine acetyltransferases (KATs) is essential for chromatin organization and function1. Among the genes coding for the MYST family of KATs (KAT5-KAT8) are the oncogenes KAT6A (also known as MOZ) and KAT6B (also known as MORF and QKF)2,3. KAT6A has essential roles in normal haematopoietic stem cells4-6 and is the target of recurrent chromosomal translocations, causing acute myeloid leukaemia7,8. Similarly, chromosomal translocations in KAT6B have been identified in diverse cancers8. KAT6A suppresses cellular senescence through the regulation of suppressors of the CDKN2A locus9,10, a function that requires its KAT activity10. Loss of one allele of KAT6A extends the median survival of mice with MYC-induced lymphoma from 105 to 413 days11. These findings suggest that inhibition of KAT6A and KAT6B may provide a therapeutic benefit in cancer. Here we present highly potent, selective inhibitors of KAT6A and KAT6B, denoted WM-8014 and WM-1119. Biochemical and structural studies demonstrate that these compounds are reversible competitors of acetyl coenzyme A and inhibit MYST-catalysed histone acetylation. WM-8014 and WM-1119 induce cell cycle exit and cellular senescence without causing DNA damage. Senescence is INK4A/ARF-dependent and is accompanied by changes in gene expression that are typical of loss of KAT6A function. WM-8014 potentiates oncogene-induced senescence in vitro and in a zebrafish model of hepatocellular carcinoma. WM-1119, which has increased bioavailability, arrests the progression of lymphoma in mice. We anticipate that this class of inhibitors will help to accelerate the development of therapeutics that target gene transcription regulated by histone acetylation.

Biochemical and Computational Assessment of Acute Phase Proteins in Dairy Cows Affected with Subclinical Mastitis.

Subclinical mastitis (SCM) is a predominant form of mastitis wherein major visible signs of disease are absent. The present study aimed to determine acute phase proteins (APPs) like ferritin, C-reactive protein (CRP), and microalbumin (Malb) in 135 composite milk and serum samples of healthy (n = 25) and SCM (n = 110) cows. As bovine mastitis is an inflammatory disease, the present study also aimed at finding novel anti-inflammatory compounds from natural sources by repurposing approach using computational studies. The findings of the present study revealed substantial elevation (p < 0.001) in milk SCC and an increase in ferritin, CRP, and Malb (p < 0.001) in milk and sera of the SCM group as compared to healthy animals. Receiver operating characteristics of milk SCC, milk, and serum APPs unraveled statistically substantial alteration (p < 0.001). Further, SCC was correlated with milk APPs ferritin (r = 0.26 **, p < 0.002), CRP (r = 0.19 *, p < 0.02), and Malb (r = 0.21 *, p < 0.01). Additionally, milk SCC was correlated with serum ferritin (r = 0.28 **, p < 0.001), CRP (r = 0.16, p > 0.05), and Malb (r = 0.16, p > 0.05). The findings of molecular docking revealed that Chaetoglobosin U was the most effective molecule that showed the highest binding affinity (kcal/mol) of -10.1 and -8.5 against ferritin and albumin. The present study concluded that the estimation of cow-side tests, SCC, and APPs in milk/serum is suitable to detect SCM and screening herd community. Furthermore, Chaetoglobosin U could be developed as a promising anti-inflammatory inhibitor; however, further studies are required to validate these findings.

Melatonin and Health: Insights of Melatonin Action, Biological Functions, and Associated Disorders.

Melatonin is ubiquitous molecule with wide distribution in nature and is produced by many living organisms. In human beings, pineal gland is the major site for melatonin production and to lesser extent by retina, lymphocytes, bone marrow, gastrointestinal tract, and thymus. Melatonin as a neurohormone is released into circulation wherein it penetrates all tissues of the body. Melatonin synthesis and secretion is supressed by light and enhanced by dark. Melatonin mostly exerts its effect through different pathways with melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2) being the predominant type of receptor that are mainly expressed by many mammalian organs. Melatonin helps to regulate sleep patterns and circadian rhythms. In addition, melatonin acts as an antioxidant and scavenges excessive free radicals generated in the body by anti-excitatory and anti-inflammatory properties. A multiple array of other functions are displayed by melatonin that include oncostatic, hypnotic, immune regulation, reproduction, puberty timing, mood disorders, and transplantation. Deficiencies in the production or synthesis of melatonin have been found to be associated with onset of many disorders like breast cancer and neurodegenerative disorders. Melatonin could be used as potential analgesic drug in diseases associated with pain and it has quite promising role there. In the past century, a growing interest has been developed regarding the wide use of melatonin in treating various diseases like inflammatory, gastrointestinal, cancer, mood disorders, and others. Several melatonin agonists have been synthesized and are widely used in disease treatment. In this review, an effort has been made to describe the biochemistry of melatonin along with its therapeutic potential in various diseases of humans.

Isolation, in vitro expansion and characterization of ovine fetal adnexa-derived mesenchymal stem cells reveals a source dependent trilineage differentiation and growth kinetics.

This study was designed to isolate, cultivate, characterize and evaluate the growth kinetics of mesenchymal stem cells (MSCs) derived from fetal adnexa of sheep. The gravid uteri of ewes were collected from a local abattoir. The MSCs isolated from different fetal regions (Wharton's Jelly [oWJ], cord blood [oCB], amniotic fluid [oAF] and amniotic Sac [oAS]) were expanded in vitro and characterized for surface and pluripotency markers. The growth kinetics of MSCs was compared at 3rd and 5th passages. Similarly, the colony-forming efficiency (CFE) assay was performed at 3rd passage. The fetal adnexa-derived ovine MSCs showed the expression of CD73, CD90 and CD105. Similarly, the MSCs also expressed pluripotency markers, OCT4 and SOX2. Besides, cells also differentiated into osteogenic, chondrogenic and adipogenic lineages. The MSCs in culture showed a typical growth curve with initial lag phase, an exponential phase, a plateau phase and a decline phase. The growth rate was highest in oAF-MSCs at P5. The population doubling time (PDT) was highest in oAS-MSCs (87.28 ± 3.24 h), whereas the colony number was highest in oAF-MSCs (53.67 ± 4.06). The study reveals that oAF-MSCs were superior which outperformed other MSCs indicating that oAF-derived MSCs could be utilized for regenerative medicine.

SNP Analysis of TLR4 Promoter and Its Transcriptional Factor Binding Profile in Relevance to Bovine Subclinical Mastitis.

Bovine mastitis is a complex infectious disease that develops in the mammary gland, predominantly caused by a bacterial infection of mammary tissue. Genetic variability of mastitis is well established and depends upon different quantitative trait loci (QTL) related to mastitis resistance or susceptibility. The susceptibility is often attributed to single-nucleotide polymorphisms (SNPs) in the variable cow breed genomes. Several global investigative attempts have resulted in studies mapping mastitis to the variations in the relevant genes. Reports have been attributed to dramatic genetic expression changes in Toll-Like Receptor 4 (TLR4) genes in mastitis-positive cows. However, the mechanism behind this variable genetic expression of TLR4 genes has been studied poorly. The present study aims to investigate SCM through various screening tests like somatic cell count (SCC), electric conductivity (EC), pH, and California mastitis test (CMT) in milk samples. This study also aims to investigate possible mechanisms behind this variable expression of TLR4 by comparative SNP evaluation and transcriptional factor profile mining. So that the important genetic mutations and effects thereof can be exploited in selecting specific breeds with higher mastitis resistance and milk yield. Seventy Holstein Frisian (HF) crossbred dairy cows were selected in the present study. The animals were screened based on various diagnostic tests (SCC, pH, EC, and CMT). Blood samples (5 mL) were collected for extraction of DNA followed by amplification of PPR1 and PPR2 of the promoter region and 5'UTR of the bovine TLR4 gene using specific primers. Sanger's enzymatic DNA sequencing technique sequenced the amplified PCR products. Further, the identification of SNPs was done through various bioinformatic tools used in this study. The findings of the present study revealed that CMT, EC, pH, and SCC could be used for the early detection of subclinical mastitis. In the present study, a significant increase in the EC, pH, and SCC in milk samples of animals affected with SCM was found in comparison to the healthy animals. The present study also revealed 16 SNPs falling in TLR4 promoter and 5' untranslated region (5'UTR) sequences in mastitis-positive genotypes compared to reference genomes. The study also investigates the potential transcriptional factor program deployed in response to variable mastitis development resistance. In the present study, the allelic and genotype frequencies of all SNP variants in the three regions viz., PPR1, PPR2, and 5'UTR, were the same indicating the absence of heterozygous condition at the respective loci. The present study has wide applicability for researchers developing mastitis-resistant breeding programs and the data generated may aid in the selection of better genetic breeds. The transcription factor binding profiles can serve as concrete leads about the studies on bovine mastitis at the molecular level and may also aid global research groups working on transcription factor (TF)-based molecular pathology of mastitis.

Computational Approaches for Identification of Potential Plant Bioactives as Novel G6PD Inhibitors Using Advanced Tools and Databases.

In glucose metabolism, the pentose phosphate pathway (PPP) is the major metabolic pathway that plays a crucial role in cancer growth and metastasis. Although it has been pointed out that blockade of the PPP is a promising approach against cancer, in the clinical setting, effective anti-PPP agents are still not available. Dysfunction of the G6PD enzyme in this pathway leads to cancer development as this enzyme possesses oncogenic activity. In the present study, an attempt was made to identify bioactive compounds that can be developed as potential G6PD inhibitors. In the present study, 11 natural compounds and a controlled drug were taken. The physicochemical and toxicity properties of the compounds were determined via ADMET and ProTox-II analysis. In the present study, the findings of docking studies revealed that staurosporine was the most effective compound with the highest binding energy of -9.2 kcal/mol when docked against G6PD. Homology modeling revealed that 97.56% of the residues were occupied in the Ramachandran-favored region. The modeled protein gave a quality Z-score of -10.13 by ProSA tool. iMODS server provided significant insights into the mobility, stability and flexibility of the G6PD protein that described the collective functional protein motion. In the present study, the physical and functional interactions between proteins were determined by STRING. CASTp server determined the topological and geometric properties of the G6PD protein. The findings of the present study revealed that staurosporine could be developed as a potential G6PD inhibitor; however, further in vivo and in vitro studies are needed for further validation of these results.

Network Pharmacology Integrated Molecular Docking and Dynamics to Elucidate Saffron Compounds Targeting Human COX-2 Protein.

Background and Objectives: Cyclooxygenase-2 (COX-2) is mostly linked to inflammation and has been validated as a molecular target for treating inflammatory diseases. The present study aimed to identify novel compounds that could inhibit COX-2, which is associated with various diseases including inflammation, and in such a scenario, plant-derived biomolecules have been considered as attractive candidates. Materials and Methods: In the present study, physiochemical properties and toxicity of natural compounds/drugs were determined by SWISSADME and ProTox-II. In the present study, the molecular docking binding features of saffron derivatives (crocetin, picrocrocin, quercetin, safranal, crocin, rutin, and dimethylcrocetin) against human COX-2 protein were assessed. Moreover, protein-protein interactions, topographic properties, gene enrichment analysis and molecular dynamics simulation were also determined. Results: The present study revealed that picrocrocin showed the highest binding affinity of -8.1 kcal/mol when docked against the COX-2 protein. PROCHECK analysis revealed that 90.3% of the protein residues were found in the most favored region. Compartmentalized Protein-Protein Interaction identified 90 interactions with an average interaction score of 0.62, and the highest localization score of 0.99 found in secretory pathways. The Computed Atlas of Surface Topography of Proteins was used to identify binding pockets and important residues that could serve as drug targets. Use of WEBnmα revealed protein dynamics by using normal mode analysis. Ligand and Receptor Dynamics used the Molecular Generalized Born Surface Area approach to determine the binding free energy of the protein. Gene enrichment analysis revealed that ovarian steroidogenesis, was the most significant enrichment pathway. Molecular dynamic simulations were executed for the best docked (COX-2-picrocrocin) complex, and the results displayed conformational alterations with more pronounced surface residue fluctuations in COX-2 with loss of the intra-protein hydrogen bonding network. The direct interaction of picrocrocin with various crucial amino-acid residues like GLN203, TYR385, HIS386 and 388, ASN382, and TRP387 causes modifications in these residues, which ultimately attenuates the activity of COX-2 protein. Conclusions: The present study revealed that picrocrocin was the most effective biomolecule and could be repurposed via computational approaches. However, various in vivo and in vitro observations are still needed.

Diagnostic utility of CT enterography in the evaluation of ileocecal mucosal lesions of uncertain diagnosis on ileocolonoscopy.

Purpose: Ileocolonoscopy aids in the diagnosis of ileocecal region pathologies when typical mucosal lesions are seen. However, in many cases the mucosal lesions of the ileocaecal region are atypical, rendering themselves to diagnostic dilemma. The present study aimed to study the role of computed tomography (CT) enterography in the evaluation of symptomatic patients who demonstrated ileocecal mucosal lesions of uncertain diagnosis on ileocolonoscopy. Material and methods: Symptomatic patients who had ileocolonoscopy documented ileocecal mucosal lesions of uncertain diagnosis were enrolled. Patients were subjected to CT enterography within 10 days of ileocolonoscopy. On CT enterography a diagnosis of Crohn's disease (CD) or ileocaecal tuberculosis (ITB) was made. The diagnosis obtained by CT enterography was correlated with the final diagnosis obtained from histopathology. Using descriptive statistics, the diagnostic performance of CT enterography was evaluated. Results: A total of 153 cases were enrolled in the study. CT enterography findings were present in 147 cases, resulting in a diagnostic yield of 96%. Out of these, 58.16% (89/153) had CD, 26.14% (40/153) had ITB, 6.5% (10/153) had infectious ileitis, and 9.15% (14/153) were indeterminate on histopathology. CT enterography correctly identified 78.65% (70/89) of CD and 75% (30/40) of ITB. CT enterography had a sensitivity of 78.65% and 75%, specificity of 67.19% and 87.61%, positive predictive value of 76.92% and 68.18%, and diagnostic accuracy of 73.86% and 84.31% for diagnosing CD and ITB, respectively. Conclusions: CT enterography provided a high diagnostic yield in ileocaecal mucosal lesions of uncertain significance on endoscopy. CD and ITB were the predominant diseases detected in these individuals. CT enterography had a good diagnostic performance in the detection of these 2 disorders.

Reduction of A-to-I RNA editing in the failing human heart regulates formation of circular RNAs.

Alterations of RNA editing that affect the secondary structure of RNAs can cause human diseases. We therefore studied RNA editing in failing human hearts. Transcriptome sequencing showed that adenosine-to-inosine (A-to-I) RNA editing was responsible for 80% of the editing events in the myocardium. Failing human hearts were characterized by reduced RNA editing. This was primarily attributable to Alu elements in introns of protein-coding genes. In the failing left ventricle, 166 circRNAs were upregulated and 7 circRNAs were downregulated compared to non-failing controls. Most of the upregulated circRNAs were associated with reduced RNA editing in the host gene. ADAR2, which binds to RNA regions that are edited from A-to-I, was decreased in failing human hearts. In vitro, reduction of ADAR2 increased circRNA levels suggesting a causal effect of reduced ADAR2 levels on increased circRNAs in the failing human heart. To gain mechanistic insight, one of the identified upregulated circRNAs with a high reduction of editing in heart failure, AKAP13, was further characterized. ADAR2 reduced the formation of double-stranded structures in AKAP13 pre-mRNA, thereby reducing the stability of Alu elements and the circularization of the resulting circRNA. Overexpression of circAKAP13 impaired the sarcomere regularity of human induced pluripotent stem cell-derived cardiomyocytes. These data show that ADAR2 mediates A-to-I RNA editing in the human heart. A-to-I RNA editing represses the formation of dsRNA structures of Alu elements favoring canonical linear mRNA splicing and inhibiting the formation of circRNAs. The findings are relevant to diseases with reduced RNA editing and increased circRNA levels and provide insights into the human-specific regulation of circRNA formation.

Pilot Study on the Impact of a Home-Based Exercise Program on Inflammatory Cytokines and Quality of Life in Men with Prostate Cancer Under Active Surveillance.

OBJECTIVES: This study aimed to demonstrate potential translation of pre-clinical studies to a home-based exercise intervention in mediating inflammatory cytokine markers and tumor progression in men under active surveillance for prostate cancer. METHODS: A 2-arm randomized control parallel group design was used. The exercise intervention consisted of 24 weeks of an aerobic and resistance home-based exercise program and results were compared to a waitlist control group. Data were collected at baseline and end of study for eotaxin, interferon-γ (INF-γ), interleukin-12 (IL-12), interleukin-1α (IL-1α), interleukin-5 (IL-5), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and vascular endothelial growth factor (VEGF), distanced walked during a 6-minute walk test (6MWT), body mass index, and health-related quality of life. RESULTS: Non-significant decreases were observed in all biomarkers, especially VEGF (pre: 125.16 ± 198.66, post: 80.29 ± 124.30, P = .06) and INF-γ (pre: 152.88 ± 312.71, post: 118.93 ± 158.79, P = .08), in the intervention group; only IL- α (pre: 332.15 ± 656.77, post: 255.12 ± 502.09, P = .20) decreased in the control group while all other biomarkers increased from baseline to end of study. A non-significant increase in 6MWT distance was observed in the intervention group, while a decrease was seen in the control group. Significant decreases in physical function, emotional wellbeing, and total composite scale on the FACIT-F were observed in the intervention group, possibly due to the isolation restrictions of COVID-19. Physical function on the SF-36 significantly increased in the control group. CONCLUSIONS: Future studies with powered samples are needed to confirm the trends observed for inflammatory biomarkers and functional fitness.

Radiographic evaluation of the margins of clinically acceptable metal-ceramic crowns.

OBJECTIVE: To radiographically evaluate the proximal marginal fit of the clinically acceptable metal-ceramic crowns. METHODS: The prospective study was conducted at the dental clinics of Aga Khan University, Karachi, from July to December 2018, and comprised metal-ceramic crowns that were evaluated prior to the cementation. Clinical examinations were conducted by seating the crown on the tooth preparation and visual assessment was done using sharp explorer along the margins. Clinically acceptable crowns were then evaluated on the bite-wing radiograph. Any horizontal or vertical inaccuracy of >0.5mm at the proximal margins was recorded as 'discrepancy'. Data was analysed using SPSS 22. RESULTS: Of the 230 interproximal margins of 115 crowns evaluated, 113(49.1%) sites had marginal discrepancies; 44(19.1%) horizontal discrepancies, 58(25.2%) vertical discrepancies, and 11(4.8%) having both horizontal and vertical discrepancies. Horizontal crown margin discrepancies were most associated with the mesial site of the maxillary crowns, while vertical discrepancies were commonly associated with the distal aspect of all crowns (p<0.050). CONCLUSIONS: Almost half of the crowns that were considered clinically acceptable had some vertical or horizontal marginal discrepancy on radiographic evaluation.

PHF6 regulates hematopoietic stem and progenitor cells and its loss synergizes with expression of TLX3 to cause leukemia.

Somatically acquired mutations in PHF6 (plant homeodomain finger 6) frequently occur in hematopoietic malignancies and often coincide with ectopic expression of TLX3. However, there is no functional evidence to demonstrate whether these mutations contribute to tumorigenesis. Similarly, the role of PHF6 in hematopoiesis is unknown. We report here that Phf6 deletion in mice resulted in a reduced number of hematopoietic stem cells (HSCs), an increased number of hematopoietic progenitor cells, and an increased proportion of cycling stem and progenitor cells. Loss of PHF6 caused increased and sustained hematopoietic reconstitution in serial transplantation experiments. Interferon-stimulated gene expression was upregulated in the absence of PHF6 in hematopoietic stem and progenitor cells. The numbers of hematopoietic progenitor cells and cycling hematopoietic stem and progenitor cells were restored to normal by combined loss of PHF6 and the interferon α and ß receptor subunit 1. Ectopic expression of TLX3 alone caused partially penetrant leukemia. TLX3 expression and loss of PHF6 combined caused fully penetrant early-onset leukemia. Our data suggest that PHF6 is a hematopoietic tumor suppressor and is important for fine-tuning hematopoietic stem and progenitor cell homeostasis.

The non-specific lethal (NSL) complex at the crossroads of transcriptional control and cellular homeostasis.

The functionality of chromatin is tightly regulated by post-translational modifications that modulate transcriptional output from target loci. Among the post-translational modifications of chromatin, reversible ε-lysine acetylation of histone proteins is prominent at transcriptionally active genes. Lysine acetylation is catalyzed by lysine acetyltransferases (KATs), which utilize the central cellular metabolite acetyl-CoA as their substrate. Among the KATs that mediate lysine acetylation, males absent on the first (MOF/KAT8) is particularly notable for its ability to acetylate histone 4 lysine 16 (H4K16ac), a modification that decompacts chromatin structure. MOF and its non-specific lethal (NSL) complex members have been shown to localize to gene promoters and enhancers in the nucleus, as well as to microtubules and mitochondria to regulate key cellular processes. Highlighting their importance, mutations or deregulation of NSL complex members has been reported in both human neurodevelopmental disorders and cancer. Based on insight gained from studies in human, mouse, and Drosophila model systems, this review discusses the role of NSL-mediated lysine acetylation in a myriad of cellular functions in both health and disease. Through these studies, the importance of the NSL complex in regulating core transcriptional and signaling networks required for normal development and cellular homeostasis is beginning to emerge.

Vascular Homeostasis and Inflammation in Health and Disease-Lessons from Single Cell Technologies.

The vascular system is critical infrastructure that transports oxygen and nutrients around the body, and dynamically adapts its function to an array of environmental changes. To fulfil the demands of diverse organs, each with unique functions and requirements, the vascular system displays vast regional heterogeneity as well as specialized cell types. Our understanding of the heterogeneity of vascular cells and the molecular mechanisms that regulate their function is beginning to benefit greatly from the rapid development of single cell technologies. Recent studies have started to analyze and map vascular beds in a range of organs in healthy and diseased states at single cell resolution. The current review focuses on recent biological insights on the vascular system garnered from single cell analyses. We cover the themes of vascular heterogeneity, phenotypic plasticity of vascular cells in pathologies such as atherosclerosis and cardiovascular disease, as well as the contribution of defective microvasculature to the development of neurodegenerative disorders such as Alzheimer's disease. Further adaptation of single cell technologies to study the vascular system will be pivotal in uncovering the mechanisms that drive the array of diseases underpinned by vascular dysfunction.

Changes in canal width and angle in curved canals in the resin blocks: Pro taper next versus one shape instruments.

OBJECTIVE: To compare the effect of OneShape and ProTaper Next file on the change in canal width and angle of curvature in simulated curved canal in resin blocks. METHODS: The quasi-experimental study was conducted at the Aga Khan University, Karachi, from January to March 2018, and comprised endodontic resin blocks that had inbuilt curved canals. These were randomly divided into 2 equal groups and were subsequently prepared using OneShape in group A, and ProTaper Next rotary instrument in group B followed by staining with red and blue ink for comparison of pre- and post operative images of canals. Standardised photographs were taken along with reference measuring scale. Independent sample t-test and Paired sample t-test were used to compare the angle of curvature and canal width changes and pre and post instrumentation changes in resin block after using both the instruments, respectively. Intra class correlation was used to determine inter-examiner reliability. The level of significance was kept at p value < 0.01. SPSS 22 was used for data analysis. RESULTS: Of the 60 blocks, 30(50%) were in each of the two groups. The mean pre-instrumentation angle of curvature was 32.3±2.13 and 31.0±3.28 degrees for groups A and B. The mean degree of canal straightening post-intervention was 1.5±0.5 and 3.6±1.38 degrees in groups A and B (p<0.001). In terms of canal width changes, OneShape file removed more resin material from the canal walls compared to the ProTaper Next system (p<0.001). CONCLUSIONS: ProTaper Next file significantly altered the angle of curvature in the resin block compared to OneShape file, but the amount of material removed from the canal space was significantly higher with the OneShape file compared to ProTaper Next.

Impact of Lift Assist Calls on Paramedic Services: A Descriptive Study.

INTRODUCTION: The aging population in Canada is steadily increasing and is placing greater demand on paramedic services, especially through the growing number of non-emergent lift assist (LA) calls. A LA occurs when a person calls paramedic services and requests assistance to get up or mobilize, usually after experiencing a fall. The patient refuses transport to the emergency department for further medical attention. LA calls are time consuming and are non-reimbursable. The increase in number of this call type, specifically amongst older adults, is placing strain on paramedic services. OBJECTIVES: The purpose of this study was to describe the characteristics of LA calls in patients aged 65 and older and determine their impact on paramedic services. METHODS: A dataset of 1,121 LA calls of patients aged 65 and older was extracted from Middlesex-London Emergency Medical Services (MLEMS) database of electronic patient care reports collected over 1 year in 2015. Statistical and qualitative analyses were performed to describe LAs, perform time analysis, and extract dominant themes from the text in report notes written by paramedics. RESULTS: The LA calls were generated from 611 individuals: 334 women (54.7%) and 275 men (45%), of which 192 (32%) individuals called more than one time. On average, a LA call lasted 43 minutes and ranged from 6 minutes to 2 hours and 23 minutes. In 2015, paramedics spent 801 hours, or the equivalent of 33 days (24 hours/day), solely conducting LAs for older adults. Text analysis determined that the bedroom (24.9%) and bathroom (17.0%) were the most common locations where LAs occurred. Most frequently, LAs were caused by a collapse or drop (28.7%), slide (25.7%), slip (16.7%), or trip (11.7%). CONCLUSION: LAs consume the time of paramedics, preventing them from responding to more urgent emergency calls. Alternative solutions are needed to reduce the negative impact of LAs on paramedic services.

An evaluation of the Sennheiser HDA 280-CL circumaural headphone for use in audiometric testing.

Objective: Evaluation of the Sennheiser HDA 280-CL circumaural headphone for the determination of (1) equivalent threshold sound pressure levels (ETSPL) for 125-18,000 Hz.; (2) real ear attenuation (250-8000 Hz); (3) insertion loss (63-18,000 Hz); (4) frequency response (125-18,000 Hz); (5) total harmonic distortion (THD) (125-10,000 Hz); and, (6) linearity (11,200-18,000 Hz).Study Sample: Twenty-five normal hearing adults aged 18-25 participated in (1) and (2).Design: (1) Hearing thresholds were measured using the Sennheiser HDA 280-CL. Frequency specific ETSPL values were calculated in an artificial ear. (2) Sound field thresholds were measured with the ears open and covered with the headphone to obtain the real ear attenuation thresholds (REAT). These values were used to determine the maximum permissible ambient noise levels (MPANL). (3) A B&K HATS mannequin recorded the output levels of a broadband pink noise with the ears open and covered with the headphones. (4, 5) The frequency response, THD and linearity were measured in an artificial ear.Results: Values for ETSPL, REAT, MPANL, insertion loss, as well as measures of frequency response, THD and linearity are presented.Conclusions: The Sennheiser HDA 280-CL meets the requirements for audiometric testing and the values presented can be used for calibration.

Management of immature necrotic permanent teeth with regenerative endodontic procedures - a review of literature.

Immature necrotic permanent tooth presents a distinctive challenge for the endodontist. Various treatment modalities have been employed to create hard tissue barrier at the apex, which includes non-vital pulp therapy with calcium hydroxide, apexification with mineral trioxide aggregate, pulp revascularisation and regeneration. Regenerative endodontics is a novel modality which involves physiological replacement of the damaged structures of tooth like dentin, root and cells of the pulp-dentin complex. Numerous published case reports have revealed increased dentinal wall thickness, continued root development and apical closure, but there is still lack of sound scientific evidence regarding histological nature of the type of tissue. The current literature review was planned to summarise the evidence regarding the treatment of immature necrotic permanent teeth by regenerative endodontic procedures.