Environmental and Health Impacts of Graphene and Other Two-Dimensional Materials: A Graphene Flagship Perspective

Two-dimensional (2D) materials have attracted tremendous interest ever since the isolation of atomically thin sheets of graphene in 2004 due to the specific and versatile properties of these materials. However, the increasing production and use of 2D materials necessitate a thorough evaluation of the potential impact on human health and the environment. Furthermore, harmonized test protocols are needed with which to assess the safety of 2D materials. The Graphene Flagship project (2013-2023), funded by the European Commission, addressed the identification of the possible hazard of graphene-based materials as well as emerging 2D materials including transition metal dichalcogenides, hexagonal boron nitride, and others. Additionally, so-called green chemistry approaches were explored to achieve the goal of a safe and sustainable production and use of this fascinating family of nanomaterials. The present review provides a compact survey of the findings and the lessons learned in the Graphene Flagship.

Sliding friction of a pillar array interface: part II, contact mechanics of single pillar pairs

Insects and small animals often utilize structured surfaces to create friction during their movements. These surfaces typically consist of pillar-like fibrils that interact with a counter surface. Understanding the mechanical interaction between such surfaces is crucial for designing structured surfaces for engineering applications. In the first part of our study, we examined friction between poly(dimethylsiloxane) (PDMS) samples with surfaces patterned with pillar-arrays. We observed that sliding between these surfaces occurs through the interfacial glide of dislocation structures. The frictional force that resists this dislocation glide is a result of periodic single pillar-pillar contact and sliding. Hence, comprehending the intricate interaction between individual pillar contacts is a fundamental prerequisite for accurately modeling the friction behavior of the pillar array. In this second part of the study, we thoroughly investigated the contact interaction between two pillars located on opposite sides of an interface, with different lateral and vertical offsets. We conducted experiments using PDMS pillars to measure both the reaction shear and normal forces. Contact interaction between pillars was then studied using finite element (FE) simulations with the Coulomb friction model, which yielded results that aligned well with the experimental data. Our result offers a fundamental solution for comprehending how fibrillar surfaces contact and interact during sliding, which has broad applications in both natural and artificial surfaces.

Sliding friction of a pillar array interface: part I

Biology is replete with examples, at length scales ranging from the molecular (ligand-receptor binding) to the mesoscopic scale (wing arresting structures on dragonflies) where shape-complementary surfaces are used to control interfacial mechanical properties such as adhesion, friction, and contact compliance. Related bio-inspired and biomimetic structures have been used to achieve unique interfacial properties such as friction and adhesion enhancement, directional and switchable properties. The ability to tune friction by altering surface structures offers advantages in various fields, such as soft robotics and tire manufacturing. Here, we present a study of friction between polydimethylsiloxane (PDMS) samples with surfaces patterned with pillar-arrays. When brought in contact with each other the two samples spontaneously produce a Moiré pattern that can also be represented as an array of interfacial dislocations that depends on interfacial misorientation and lattice spacing. Misorientation alone produces an array of screw dislocations, while lattice mismatch alone produces an array of edge dislocations. Relative sliding motion is accompanied by interfacial glide of these patterns. The frictional force resisting dislocation glide arises from periodic single pillar-pillar contact and sliding. We study the behavior of pillar-pillar contact with larger (millimeter scale) pillar samples. Inter-pillar interaction measurements are combined with a geometric model for relative sliding to calculate frictional stress that is in good agreement with experiments.

Low language capacity in childhood: A systematic review of prevalence estimates

BACKGROUND AND AIMS

Epidemiological studies have provided invaluable insight into the origin and impact of low language skills in childhood and adolescence. However, changing terminology and diagnostic guidelines have contributed to variable estimations of the prevalence of developmental language difficulties. The aim of this review was to profile the extent and variability of low language prevalence estimates through a systematic review of epidemiological literature.

METHODS

A systematic review of the empirical research (August 2022) was undertaken to identify studies that aimed to estimate the prevalence of low language skills in children (<18 years). A total of 19 studies published between 1980-2022 met inclusion criteria for review.

RESULTS

Studies reported prevalence estimates of low language skills in children between 1 and 16 years. Estimated rates varied from 0.4% to 25.2%. More stable estimations were observed in studies of children aged 5 years and older and those that applied updated diagnostic criteria to performance on standardised assessments of receptive and expressive language.

CONCLUSIONS AND IMPLICATIONS

The estimated prevalence of low language skills in childhood varies considerably in the literature. Application of updated diagnostic criteria, including the assessment of functional impact, is critical to inform advocacy efforts and govern social, health and educational policies.

WHAT THIS PAPER ADDS

What is already known on the subject Epidemiological research has informed our understanding of the origin and impact of low language capacity in childhood. Childhood language disorder is met with a rich history of evolving terminology and diagnostic guidelines to identify children with low language skills. Inconsistent definitions of and methods to identify low language in children have resulted in variable prevalence estimates in population-based studies. Variability in prevalence estimates impacts advocacy efforts to inform social, health and educational policy for child language disorder. What this study adds A total of 19 studies published at the time of this review aimed to provide estimates of the proportion of children who experience low language skills. Prevalence estimates varied between 0.4% and 25.2%, with more stable estimates reported in studies of older school-age children and those which utilised standardised assessments of both expressive and receptive language. Few studies utilised assessments of functional impact of language difficulties, which is misaligned with updated diagnostic criteria for child language disorder. What are the clinical implications of this work? This review reports substantial variability in estimates of the proportion of children and adolescents who live with low language skills. This variability underscores the importance of applying updated diagnostic criteria to identify the prevalence low language in childhood. Efforts to estimate the prevalence of low language must include measures of functional impact of low language skills. This aligns with clinical recommendations, which call for routine assessment of functional outcomes. To this end, we require a unified understanding of the term 'functional impact' in the context of low language, including the development and evaluation of measures that assess impact across emotional, social and academic domains.

UbiSeCEF: Ubilab's Secure Cloud Environment Framework for Public Health Research

Issue/Problem

The adoption of cloud-based public health research over personal health data in an academic setting in Canada is still in its early stages and lacks the necessary maturity to handle such technologies. This can be attributed to the fact that many public health researchers lack the required IT knowledge to set up and use these environments securely and effectively.

Description of Problem

The lack of expertise among public health researchers in Canada has led to a slow adoption of cloud-based public health research. This has resulted in a significant gap between the potential benefits of cloud-based research and the current state of practice. To address this challenge, we propose Ubilab's Secure Cloud Environment Framework (UbiSeCEF) as guidelines for those interested in conducting similar public research.

Results

UbiSeCEF's components were developed with consideration given to requirements from stakeholders, Ubilab's operations and data objectives, state-of-the-art technologies, and laws and standards that regulate public health research and personal health data sharing. The framework utilizes Azure's data governance framework, virtual private networks (VPN), role-based authentication, and policy-based access to control access to resources and research data. The implementation of UbiSeCEF provides a secure, flexible, and efficient environment for cloud-based public health research.

Lessons

The lack of IT expertise among public health researchers can hinder the adoption of cloud-based public health research. To address this challenge, the development of frameworks like UbiSeCEF can provide guidance for secure and effective implementation. The use of state-of-the-art technologies and compliance with laws and standards that regulate public health research and personal health data sharing can greatly enhance the quality and reliability of research outcomes while ensuring the protection of personal health data.

Key messages

• Framework developed to enhance secure & effective adoption of cloud-based public health research by addressing lack of IT expertise among researchers.

• The research aims to assist other researchers and institutions in navigating the complexities of cloud-based public health research while maintaining the privacy and security of public heath data.

Public health monitoring of behavioural risk factors in USA: An exploratory study

Background

The COVID-19 pandemic's restrictions had a significant impact on behavioural markers such as physical, sedentary and sleep activity. The Behavioral Risk Factor Surveillance System is a key data source for public health surveillance in the USA but is limited by subjectivity and data quality, and new-generation data sources like Fitbits face challenges with battery life and data access. This research study aims to use zero-effort technology and IoT-based big data to evaluate the impact of the COVID-19 pandemic on population-level behavioural changes in USA.

Methods

The study used a proposed methodology to analyze data from 470 households in New Mexico, USA, using the DYD dataset from Donate your Data initiative by ecobee (a smart thermostat company). The Microsoft Azure data lake is used for the storage of raw data and the Azure databricks is used for data pre-processing, processing, and analysis. The Gaussian mixture model is used to identify sleep parameters by segmenting the sleep cycle records into different clusters. The quantity of sleep is measured by a motion sensor based on the absence of movement, and an increase in sensor activation indicates longer duration of household occupancy.

Results

The findings show significant changes at the household and population level for the selected behavioural health indicators (sleep-time, wake-up time, time spent indoors, time spent outdoors) during COVID-19 pandemic, which could be attributed to the policy changes implemented to curb the spread of COVID-19. The study findings are shown by 1) heatmap visualizations at the household level showing trends for the selected indicators during the Covid-19 pandemic; and 2) statistical analysis indicating a significant difference in selected behavioural health indicators before and during the pandemic.

Conclusions

These innovative data analytics have the potential to provide real-time insights and alert system activation to monitor, promote, and improve public health.

Key messages

• Sleep health analysis using IoT data is a novel method of measuring public health indicators objectively using zero effort technology.

• The available evidence from this study can further offer surveillance systems with near-real-time behavioral markers; alert system activation; and measure short- and long-term impact policy changes.

Exploiting Mass Spectrometry to Unlock the Mechanism of Nanoparticle-Induced Inflammasome Activation

Nanoparticles (NPs) elicit sterile inflammation, but the underlying signaling pathways are poorly understood. Here, we report that human monocytes are particularly vulnerable to amorphous silica NPs, as evidenced by single-cell-based analysis of peripheral blood mononuclear cells using cytometry by time-of-flight (CyToF), while silane modification of the NPs mitigated their toxicity. Using human THP-1 cells as a model, we observed cellular internalization of silica NPs by nanoscale secondary ion mass spectrometry (nanoSIMS) and this was confirmed by transmission electron microscopy. Lipid droplet accumulation was also noted in the exposed cells. Furthermore, time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed specific changes in plasma membrane lipids, including phosphatidylcholine (PC) in silica NP-exposed cells, and subsequent studies suggested that lysophosphatidylcholine (LPC) acts as a cell autonomous signal for inflammasome activation in the absence of priming with a microbial ligand. Moreover, we found that silica NPs elicited NLRP3 inflammasome activation in monocytes, whereas cell death transpired through a non-apoptotic, lipid peroxidation-dependent mechanism. Together, these data further our understanding of the mechanism of sterile inflammation.

Label-free detection of polystyrene nanoparticles in Daphnia magna using Raman confocal mapping

Micro- and nanoplastic pollution has emerged as a global environmental problem. Moreover, plastic particles are of increasing concern for human health. However, the detection of so-called nanoplastics in relevant biological compartments remains a challenge. Here we show that Raman confocal spectroscopy-microscopy can be deployed for the non-invasive detection of amine-functionalized and carboxy-functionalized polystyrene (PS) nanoparticles (NPs) in Daphnia magna. The presence of PS NPs in the gastrointestinal (GI) tract of D. magna was confirmed by using transmission electron microscopy. Furthermore, we investigated the ability of NH₂-PS NPs and COOH-PS NPs to disrupt the epithelial barrier of the GI tract using the human colon adenocarcinoma cell line HT-29. To this end, the cells were differentiated for 21 days and then exposed to PS NPs followed by cytotoxicity assessment and transepithelial electrical resistance measurements. A minor disruption of barrier integrity was noted for COOH-PS NPs, but not for the NH₂-PS NPs, while no overt cytotoxicity was observed for both NPs. This study provides evidence of the feasibility of applying label-free approaches, i.e., confocal Raman mapping, to study PS NPs in a biological system.

Sex differences in minutiae frequencies of thumbprint with respect to dermatoglyphic patterns

Abstract

The present study is an attempt to study the sex differences in minutiae frequencies of thumbprint with respect to dermatoglyphic patterns. A sample of 100 subjects (50 males and 50 females) were gathered from Shimla, Himachal Pradesh (North India). In regards to pattern type, maximum number of minutiae was present in loop pat-tern followed by whorls and least minutiae were in the arches in the right hand of both the sexes and left hand of females only, whereas in left hand of the males highest frequency of minutiae were noticed in whorls followed by loops and lowest in the arches, thereby indicating the lessened bimanual symmetry in males. It can be inferred from the present study that the simple pattern (arch) has less discontinuance in the regular flow of the ridges, while the complex patterns (loops and whorls) exhibited more interruptions in the dermal ridges.

Unilateral sacral erector spinae plane block for lower limb surgery in children

The erector spinae plane block is a versatile regional anaesthesia technique used for a variety of truncal surgeries. A novel variation is the sacral erector spinae plane block which is gaining popularity for perineal and anorectal procedures. Local anaesthetic injected at this level blocks the sacral dermatomes and has the potential for more proximal spread to involve lumbar nerve fibres via spread to the lumbar plexus or the epidural space. The advantage of a sacral erector spinae plane block over a neuraxial block is that it is less invasive and may have a better safety profile: there is a reduced risk of epidural haematoma, epidural abscess, haemodynamic instability and motor weakness of the lower extremities. Until now, this approach has been used for midline surgical procedures when the local anaesthetic was injected bilaterally. Its application for lower limb procedures with a single unilateral injection has not been described. We report the use of a unilateral sacral erector spinae plane block at the level of the S2 median crest in two children undergoing lower limb procedures of the hip and thigh. The block was found to provide effective peri-operative analgesia with minimal need for any opioid analgesics and without any significant adverse effects.

Impact of talk test based aerobic exercise on glycaemic control and anthropometric measures among patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterised by the chronic hyperglycaemia which leads to various micro and macrovascular complications. The aim of present study was to evaluate the impact of talk test based aerobic exercise on glycaemic control and anthropometric measures among adults with (T2DM). In this double blind randomised controlled trial (RCT), aerobic exercises/walking was used as intervention. The patients were divided into three groups based on the tool of exercise intensity prescription: a talk test-based group (TTG, n=30), a rating of perceived exertion-based group (RPEG, n=30), and a control group (CG, n=30). Glycated haemoglobin (HbA1c) was evaluated at baseline and after 8 weeks. Anthropometric measures, i.e. body mass index (BMI), and waist circumference (WC) were evaluated at baseline, 4 weeks, and 8 weeks. Wilcoxon rank-sum/repeated measure of ANOVA and Kruskal-Wallis test/ANOVA were used for within and between group comparison, respectively, on the basis of normality of the data. The mean HbA1c change in TTG, RPEG, and CG was -0.29, -0.28, and -0.04, respectively, and it was significantly greater in TTG and RPEG as compared to CG. The reduction of HbA1c, BMI, and WC was reported in each group. However, the reduction in the experimental groups, i.e. TTG and RPEG was significantly greater than in the control group (P≤0.01). However, there was no significant difference found between the experimental groups (P>0.05). TT based aerobic exercise is effective in improving glycaemic control and anthropometric measures. Therefore, TT can be used for the exercise prescription of these patients.

The study is registered at the Clinical Trial Registry-India under no. CTRI/2019/02/017531.

MeQryEP: A Texture Based Descriptor for Biomedical Image Retrieval

Image texture analysis is a dynamic area of research in computer vision and image processing, with applications ranging from medical image analysis to image segmentation to content-based image retrieval and beyond. "Quinary encoding on mesh patterns (MeQryEP)" is a new approach to extracting texture features for indexing and retrieval of biomedical images, which is implemented in this work. An extension of the previous study, this research investigates the use of local quinary patterns (LQP) on mesh patterns in three different orientations. To encode the gray scale relationship between the central pixel and its surrounding neighbors in a two-dimensional (2D) local region of an image, binary and nonbinary coding, such as local binary patterns (LBP), local ternary patterns (LTP), and LQP, are used, while the proposed strategy uses three selected directions of mesh patterns to encode the gray scale relationship between the surrounding neighbors for a given center pixel in a 2D image. An innovative aspect of the proposed method is that it makes use of mesh image structure quinary pattern features to encode additional spatial structure information, resulting in better retrieval. On three different kinds of benchmark biomedical data sets, analyses have been completed to assess the viability of MeQryEP. LIDC-IDRI-CT and VIA/I-ELCAP-CT are the lung image databases based on computed tomography (CT), while OASIS-MRI is a brain database based on magnetic resonance imaging (MRI). This method outperforms state-of-the-art texture extraction methods, such as LBP, LQEP, LTP, LMeP, LMeTerP, DLTerQEP, LQEQryP, and so on in terms of average retrieval precision (ARP) and average retrieval rate (ARR).

Effect of subjective tool based aerobic exercise on pulmonary functions in patients with type 2 diabetes mellitus – a feasibility RCT

Literature has proved the benefit of exercise on pulmonary functions among the patients with type 2 diabetes mellitus (T2DM). However, objective tools of exercise intensity prescription have been used in previous trials. The trials to explore the effectiveness of subjective tools-based exercise on pulmonary functions among these patients are scarce. The purpose of this study was to explore the feasibility of subjective tools-based exercise among patients with T2DM. Another objective was to see the effectiveness of this kind of exercise on pulmonary functions among patients with T2DM. 49 patients were randomly allotted to three groups, talk test group (TTG, n=16); rating of perceived exertion group (RPEG, n=16); and control group (CG, n=17). Subjects were evaluated for five progression criteria. The intervention period for the groups was 8 weeks. Recruitment and retention rate was 62.82 and 75.5%, respectively. Adherence rate was 67.34% and 58.91% for supervised and unsupervised sessions, respectively. 78.38% of the patients were available for post-intervention outcome evaluation. A significant increase in pulmonary functions in both the experimental groups (P=0.00) was found after 8 weeks of training. This study provides evidence that a trial of this nature is feasible with a few amendments in methodology. Additionally, the study also concluded that the subjective tool based aerobic exercise may be effective in improving pulmonary functions among patients with T2DM. Trial registration at Clinical Trial Registry-India: CTRI/2019/02/017531.

High-content phenotypic screening identifies novel chemistries that disrupt mosquito activity and development

New classes of chemistries are needed to control insecticide resistant populations of mosquitoes and prevent transmission of vector-borne diseases (VBDs). Organismal screens of chemical collections have played an important role in the search for new vector insecticides and the identification of active ingredients (AIs) that cause rapid mortality of mosquitoes. Advances in image-based screening offer an opportunity to identify chemistries that operate via novel biochemical modes and investigate the range of phenotypes exhibited by mosquitoes following exposure to lethal and sub-lethal chemical dose. An automated, high throughput phenotypic screen (HTS) employing high-content imaging of first instar (L1) Aedes aegypti larvae was developed to identify chemistries associated with mortality and atypical morphological phenotypes. A pilot screen of the Library of Pharmacologically Active Compounds (LOPAC₁₂₈₀) identified 92 chemistries that disrupted larval activity and development, including conventional insecticides and chemistries known to modulate G protein-coupled receptors (GPCRs) and other molecular targets in mammalian systems. Secondary assay series were used to evaluate a selection of chemistries for impacts on mosquito activity, survival and development. Ritodrine hydrochloride reduced mobility of larvae but had no observable effect on survival and development of mosquitoes. High doses of metergoline suppressed larval activity and sub-lethal dose resulted in pupal mortality. Assay data support the utility of phenotypic screening and diverse entomological end-points for discovery of novel insecticidal chemical scaffolds. The insecticide discovery process must consider how multi-modal efficacy spectra contribute to vector and VBD control.

Effect of type 1 tympanoplasty on the quality of life of patients suffering from chronic otitis media (safe type)

Background

Chronic otitis media (COM) remains a major public health issue and is associated with relentless discharge from the ear, pain, significant functional limitation of hearing, leading to communication problems and frequent specialist visits.

Aims

To assess the improvement in quality of life of patients of COM (safe type) and surgical success in terms of graft uptake and improvement in hearing.

Patients and Methods

A prospective questionnaire-based outcome study was directed in 100 patients with COM who were treated with Type I Tympanoplasty at our institution between May 2018 and May 2020. All patients were asked to fill Modified Chronic Otitis Media 4 (COM-4) survey before operation and 3 months after operation. Preoperative and postoperative total ear scores, audiological results, postoperative graft uptake were assessed.

Results

The correlation between preoperative and postoperative assessment by questionnaire was statistically critical (P < 0.001). There was significant improvement in hearing postoperatively (P < 0.001). Effective graft uptake was seen in 80%.

Conclusion

The current study emphasizes that Type 1 Tympanoplasty fundamentally improves quality of life of patients in terms of physical suffering, hearing loss, emotional distress postoperatively.

Comparative efficacy and safety of acetaminophen, topical and oral non-steroidal anti-inflammatory drugs for knee osteoarthritis: evidence from a network meta-analysis of randomized controlled trials and real-world data

OBJECTIVE

Current global guidelines regarding the first-line analgesics (acetaminophen, topical or oral non-steroidal anti-inflammatory drugs [NSAIDs]) for knee osteoarthritis remain controversial and their comparative risk-benefit profiles have yet to be adequately assessed.

DESIGN

Pubmed, Embase, Cochrane Library, and Web of Science were searched from database inception to March 2021 for randomized controlled trials (RCTs) comparing acetaminophen, topical NSAIDs and oral NSAIDs directly or indirectly in knee osteoarthritis. Bayesian network meta-analyses were conducted. A propensity-score matched cohort study was also conducted among patients with knee osteoarthritis in The Health Improvement Network database.

RESULTS

122 RCTs (47,113 participants) were networked. Topical NSAIDs were superior to acetaminophen (standardized mean difference [SMD] = -0.29, 95% credible interval [CrI]: -0.52 to -0.06) and not statistically different from oral NSAIDs (SMD = 0.03, 95% CrI: -0.16 to 0.22) for function. It had lower risk of gastrointestinal adverse effects (AEs) than acetaminophen (risk ratio [RR] = 0.52, 95%CrI: 0.35 to 0.76) and oral NSAIDs (RR = 0.46, 95%CrI: 0.34 to 0.61) in RCTs. In real-world data, topical NSAIDs showed lower risks of all-cause mortality (hazard ratio [HR] = 0.59, 95% confidence interval [CI]: 0.52 to 0.68), cardiovascular diseases (HR = 0.73, 95%CI: 0.63 to 0.85) and gastrointestinal bleeding (HR = 0.53, 95%CI: 0.41 to 0.69) than acetaminophen during the one-year follow-up (n = 22,158 participants/group). A better safety profile was also observed for topical than oral NSAIDs (n = 14,218 participants/group).

CONCLUSIONS

Topical NSAIDs are more effective than acetaminophen but not oral NSAIDs for function improvement in people with knee osteoarthritis. Topical NSAIDs are safer than acetaminophen or oral NSAIDs in trials and real-world data.

Synovitis and bone marrow lesions associate with symptoms and radiographic progression in hand osteoarthritis: a systematic review and meta-analysis of observational studies

AIMS

To systematically review observational studies for the association between features detected on ultrasound (US) and magnetic resonance imaging (MRI) and, symptoms, signs and radiographic progression of hand osteoarthritis (OA).

METHODS

Medline, Web of Science, EMBASE, CINAHL and AMED were searched from inception to 14^th January 2020 to identify relevant studies. Quality of studies was assessed using the Newcastle-Ottawa scales and data were extracted. Odds ratios (OR) and linear regression coefficients and 95% confidence intervals (CI) were pooled using the random-effects model (METAN package, Stata v16.1). Heterogeneity and publication bias were assessed.

RESULTS

Thirty-two studies using US and MRI comprising 1,350 and 638 participants respectively were included. While only grey-scale synovitis (GSS) associated with AUSCAN-pain (pooled Regression coefficient (95% CI): 0.46 (0.13-0.79); 0-20 scale for AUSCAN-pain), US-detected osteophytes, GSS and power Doppler (PD) [pooled ORs (95% CI): 2.68(2.16-3.33), 2.38(1.74-3.26) and 2.04 (1.45-2.88)] as well as MRI-detected bone marrow lesions (BMLs), synovitis, osteophytes, and central bone erosions (CBEs) associated with joint tenderness [pooled ORs (95% CI): 2.59(2.12-3.18), 2.17(1.85-2.54), 2.15(1.55-2.99), and 2.41 (1.45-4.02)] respectively. US-detected GSS and PD associated with radiographic progression of CBEs [pooled ORs 5.37, 5.08], osteophytes [pooled ORs 5.17, 6.45], and joint space narrowing (pooled ORs 4.28, 4.36) whilst MRI-detected synovitis and BMLs associated with increasing KL grades with pooled ORs 2.92, 2.54 respectively.

CONCLUSIONS

US and MRI-detected structural and inflammatory changes associate with tenderness, whilst articular inflammation and subchondral bone damage associate with radiographic hand OA progression. There was inconsistent relationship between these changes and pain.

Bio-therapeutics from human milk: prospects and perspectives

Human milk is elixir for neonates and is a rich source of nutrients and beneficial microbiota required for infant growth and development. Its benefits prompted research into probing the milk components and their use as prophylactic or therapeutic agents. Culture-independent estimation of milk microbiome and high-resolution identification of milk components provide information, but a holistic purview of these research domains is lacking. Here, we review the current research on bio-therapeutic components of milk and simplified future directions for its efficient usage. Publicly available databases such as PubMed and Google scholar were searched for keywords such as probiotics and prebiotics related to human milk, microbiome and milk oligosaccharides. This was further manually curated for inclusion and exclusion criteria relevant to human milk and clinical efficacy. The literature was classified into subgroups and then discussed in detail to facilitate understanding. Although milk research is still in infancy, it is clear that human milk has many functions including protection of infants by passive immunization through secreted antibodies, and transfer of immune regulators, cytokines and bioactive peptides. Unbiased estimates show that the human milk carries a complex community of microbiota which serves as the initial inoculum for establishment of infant gut. Our search effectively screened for evidence that shows that milk also harbours many types of prebiotics such as human milk oligosaccharides which encourage growth of beneficial probiotics. The milk also trains the naive immune system of the infant by supplying immune cells and stimulatory factors, thereby strengthening mucosal and systemic immune system. Our systematic review would improve understanding of human milk and the inherent complexity and diversity of human milk. The interrelated functional role of human milk components especially the oligosaccharides and microbiome has been discussed which plays important role in human health.

Olfactory and taste dysfunction in coronavirus disease 2019 patients: its prevalence and outcomes

OBJECTIVES

To evaluate the occurrence, clinical course and outcomes of olfactory and gustatory dysfunction in patients with laboratory confirmed coronavirus disease 2019 infection.

METHODS

This is a prospective cross-sectional study of patients diagnosed with coronavirus disease 2019 infection by reverse transcription polymerase chain reaction over two months. The epidemiological and clinical outcomes studied were: age, sex, general symptoms, and olfactory and taste dysfunction.

RESULTS

A total of 410 coronavirus disease 2019 infected patients were included in the study, with 262 males (63.9 per cent) and 148 females (36.1 per cent). Ninety-nine patients (24.1 per cent) reported chemosensory dysfunction, of which 85 patients (20.7 per cent) reported both olfactory and taste dysfunction. Olfactory and taste dysfunction were proportionally more common in females. The mean duration of olfactory and taste dysfunction was 4.9 days, with a range of 2-15 days.

CONCLUSION

Olfactory and taste dysfunction are prevalent symptoms in coronavirus disease 2019 patients. In this study, they were more common in females than males. The occurrence of such dysfunctions is lower in the Indian population than in the European population.

Klotho gene polymorphism in renal stone formers from Northwestern India

Klotho gene is an important gene involved in calcium homeostasis, and polymorphisms of this gene may render the individual prone to renal stone formation. We evaluated G395A single nucleotide polymorphisms (SNPs) of Klotho gene at rs1207568 in renal stone patients of North India. This was a prospective study involving 150 patients of renal stone disease (aged 15-60 years) and 100 age- and sex-matched controls. The DNA was isolated and subjected to polymerase chain reaction (PCR) for identifying the G395A Klotho SNPs at rs1207568. Confronting two pair primers were used, and gel electrophoresis showing two bands at 175,252 bp was considered as GG genotype, three bands at 121,175 and 252 bp as GA and two bands at 121 and 252 bp as AA genotype. The association between genotype and cases was evaluated by using Chi-square test and logistic regression analysis. Cases and controls were well matched for age (40.65 vs 42.06, p = 0.063) and sex (p = 0.420). Significantly high proportion of patients with renal stones had GG genotype as compared to controls (odds ratio (OR) 2.37(1.39,4.03), p = 0.001). None of the participants (cases and controls) had homozygous recessive AA genotype. The risk of stone formation was significantly higher in the population carrying G allele {OR 1.94 (1.225-3.073), p 0.004}. Mean serum calcium was higher in stone formers with GG genotype as compared to those with GA genotype (9.16 mg/dl vs 8.91 mg/dl; p = 0.06). GG genotype of G396A Klotho gene SNPs is associated with renal stone formation. The G allele carrier is twice at risk of renal stone formation. The absence of AA genotype in north-western Indian population remains a curiosity.

Gastrointestinal stress as innate defence against microbial attack

The human gastrointestinal (GI) tract has been bestowed with the most difficult task of protecting the underlying biological compartments from the resident commensal flora and the potential pathogens in transit through the GI tract. It has a unique environment in which several defence tactics are at play while maintaining homeostasis and health. The GI tract shows myriad number of environmental extremes, which includes pH variations, anaerobic conditions, nutrient limitations, elevated osmolarity etc., which puts a check to colonization and growth of nonfriendly microbial strains. The GI tract acts as a highly selective barrier/platform for ingested food and is the primary playground for balance between the resident and uninvited organisms. This review focuses on antimicrobial defense mechanisms of different sections of human GI tract. In addition, the protective mechanisms used by microbes to combat the human GI defence systems are also discussed. The ability to survive this innate defence mechanism determines the capability of probiotic or pathogen strains to confer health benefits or induce clinical events respectively.

OP0066 IMAGING-DETECTED FEATURES OF HAND OSTEOARTHRITIS ASSOCIATE WITH SYMPTOMS AND RADIOGRAPHIC CHANGE OVER TIME: A SYSTEMATIC REVIEW AND META-ANALYSIS OF OBSERVATIONAL STUDIES

Background:

Osteoarthritis (OA) commonly affects joints in the hand. The natural history of hand OA is not well understood, and the local determinants of symptoms and structural changes over time remain unclear.

Objectives:

To investigate, in both cross-sectional and prospective studies, the association between imaging (ultrasound [US] and magnetic resonance imaging [MRI]) features and symptoms of hand OA, and to examine in prospective studies whether imaging-detected features at baseline predict subsequent clinical and radiographic outcomes.

Methods:

A systematic literature search was conducted in five databases including Medline, Web of Science, EMBASE, CINAHL and AMED in April 2018. The search was designed to capture published observational studies on the use of US and MRI in hand OA with no language restrictions. Odds ratios (OR), risk ratios (RR), and 95% confidence interval (CI) between [1] imaging features and hand OA symptoms at baseline, and [2] baseline-imaging features and follow-up outcomes were extracted and pooled using random effects model. Outcomes were defined as either incidence or progression of pre-existing features. Risk of bias assessment was performed using the Newcastle-Ottawa Scales. Heterogeneity and publication bias were assessed.

Results:

The search identified 2818 citations, which reduced to 2216 after duplicate removal. Screening of titles and abstracts found 140 articles which met the inclusion criteria. After full text screening, 25 were included for analysis, including 452 participants (87% women) for US and 298 participants (86% women) for MRI with mean ages 60.3 and 62.5, respectively. Imaging-detected structural OA features were preferentially found in distal interphalangeal joints (DIPJs) followed by carpometacarpal (CMCJ) and proximal interphalangeal (PIPJ) joints. Metacarpophalangeal joints were least affected. However, the distribution pattern was different for inflammatory features for which the CMCJ was the most affected, and with no clear difference between DIPJs and PIPJs (Figure 1).

Figure 1.

Hand map of grey-scale synovitis derived from pooled estimates of prevalence across studies (%[95% CI])

Of 10 US and 5 MRI studies examining association at baseline, joint tenderness was associated with US osteophytes (pooled ORs 2.30, 95% CI 1.90-2.79), grey-scale synovitis (3.00, 2.33-3.84), synovial effusion (2.92, 2.29-3.72), and power Doppler (PD) (2.30, 1.68-3.15). Similar relationships were observed with MRI features (Figure 2). Six studies did not find any association between imaging features and self-reported outcomes. However, association was observed with US- and MRI-detected synovitis in one study each, and MRI-detected structural features in two. Statistical pooling was not possible for these outcomes due to heterogeneous data.

Figure 2.

Forest plot showing pooled odds ratio between baseline magnetic resonance imaging features of hand osteoarthritis and joint tenderness.

Of the 9 US and 5 MRI studies for prediction, a dose-dependent relationship was observed between baseline PD and radiographic change at follow-up (Figure 3). Similar results were observed for MRI features and Kellgren-Lawrence change. The pooled ORs (95% CI) was 2.66 (1.88, 3.78) for bone marrow lesions, and 2.18 (1.53, 3.10) and 4.7 (3.08, 7.18) for grades 1 and 2 synovitis, respectively. Data to predict change in clinical outcomes however, were lacking.

Figure 3.

Forest plot showing pooled odds ratio between baseline power Doppler and radiographic change over time

Conclusion:

Imaging-detected inflammatory features and osteophytes associate with joint tenderness. In addition, imaging-detected inflammatory changes at baseline predict future development and progression of structural OA changes, indicating that inflammation may precede radiographically-detectable structural changes.

Disclosure of Interests:

Abasiama Obotiba: None declared, Subhashisa Swain: None declared, Jaspreet Kaur: None declared, Khalid Yaseen: None declared, Michael Doherty Grant/research support from: AstraZeneca funded the Nottingham Sons of Gout study, Consultant of: Advisory borads on gout for Grunenthal and Mallinckrodt, Weiya Zhang Consultant of: Grunenthal for advice on gout management, Speakers bureau: Bioiberica as an invited speaker for EULAR 2016 satellite symposium, Abhishek Abhishek Grant/research support from: AstraZeneca and OxfordImmunotech, Speakers bureau: Menarini pharmaceuticals

THU0461 THE COMPARATIVE EFFICACY OF NON-PHARMACOLOGICAL INTERVENTIONS FOR FIBROMYALGIA: A SYSTEMATIC REVIEW WITH BAYESIAN NETWORK META-ANALYSIS

Background:

Non-pharmacological interventions are recommended as first-line treatment options in the management of fibromyalgia (FM)1. However, whether one intervention is more effective than another for specific patient-centred outcomes in FM is unknown.

Objectives:

To compare the relative efficacy of non-pharmacological interventions on FM impact questionnaire (FIQ), pain, fatigue, sleep and depression in people with FM.

Methods:

A Bayesian network meta-analysis was conducted. Randomised controlled trials (RCTs) assessing any non-pharmacological intervention versus usual care, placebo or active controls in patients with FM aged >16 years were searched for in seven databases. A common comparator was identified between interventions to develop a network (Figure 1). Standardised mean difference (SMD) and 95% credible interval (CrI) was estimated between interventions. Direct and indirect evidence were pooled using the random effect model. Modified Cochrane‘s tool was used to assess risk of bias.

Figure 1.

Network map of different interventions evaluating FIQ

Results:

78 studies (n = 5,639 participants) met the inclusion criteria. There was a high risk of bias on blinding and most trials had small sample size (n<50).

While multidisciplinary treatment (MDT) was the best for improving pain [-1.28 (-1.84, -0.72)], sleep [-1.14 (-2.38, 0.07)] and depression [-1.20 (-1.99, -0.46)], balneotherapy and exercise were the most effective treatments for FIQ [-1.06 (1.51, -0.61)] and fatigue [-0.75 (-1.35, -0.25)], respectively (Figure 2).

Figure 2.

Standardised mean difference (SMD) versus usual care in descending order for different outcomes

Data from 47 exercise trials (n = 3,271 participants) were analysed to examine comparative efficacy of different exercise types. Strengthening showed the greatest benefits for FIQ [-0.76 (-1.39, -0.15)], pain [-0.94 (-1.58, -0.29)] and depression [-0.83 (-1.53, -0.14)], whereas aerobic exercise was the best for fatigue [-0.98 (-2.33, 0.18)] and sleep [-0.96 (-2.08, 0.13)] (Table 1).

Table 1.

Relative effect size between types of exercises

FIQAerobic-0.58(-1.13, -0.03)-0.09(-0.55, 0.36)0.18(-0.44, 0.80)0.12(-0.36, 0.57)-0.57(-0.95, -0.24)-0.60(-1.36, 0.18)Flexibility0.49(-0.23, 1.20)0.76(-0.07, 1.58)0.70(-0.04, 1.41)0.004(-0.67, 0.64)-0.10(-0.74, 0.53)0.49(-0.50, 1.49)Mind-body0.27(-0.37, 0.91)0.20(-0.24, 0.65)-0.49(-0.85, -0.15)0.05(-0.59, 0.70)0.65(-0.35, 1.63)0.16(-0.53, 0.85)Mixed-0.06(-0.73, 0.59)-0.69(-1.06, -0.34)0.21(-0.42, 0.84)0.80(-0.19, 1.79)0.31(-0.41, 1.02)-0.06(-0.73, 0.59)Strengthening-0.76(-1.39, -0.15)-0.73(-1.16, -0.30)-0.13(-1.02, 0.74)-0.62(-1.15, -0.11)-0.78(-1.31, -0.26)-0.94(-1.58, -0.29)Usual carePain

Data are standard mean difference (95% credible intervel) between exercises, pairwised from the top left to the bottom right. The negative value indicates that the first exercise is more effective than the second exercise. For example, aerobic is better than flexibility for FIQ -0.58 (-1.13, -0.13), but not pain -0.60 (-1.36, 0.18).

Conclusion:

Several non-pharmacological interventions are beneficial for FM. However, the effect size varies between interventions and outcomes. All types of exercises are effective for FIQ and pain apart from flexibility exercise. The results of this study may be used to guide the selection of the most effective non-pharmacological interventions according to the predominant symptom in individual patients.

References:

[1]Macfarlane GJ et al. Ann Rheum Dis 2017;76(2):3-8-28.

Disclosure of Interests: :

None declared

An endophytic Penicillium oxalicum isolated from Citrus limon possesses antioxidant and genoprotective potential

AIMS

This study aimed at isolating endophytic fungi from Citrus limon (L.) possessing antioxidative and genoprotective potential.

METHODS AND RESULTS

Endophytic fungi were screened for antioxidant activity using 2,2-diphenyl,1-picryl hydrazyl radical scavenging assay and maximum activity (79·70%) was exhibited by culture MP1 identified to be Penicillium oxalicum on the basis of morphological and molecular characteristics. The ethyl acetate extract of MP1 was subjected to silica column chromatography followed by LH 20 column chromatography for purification of active metabolites. The partially purified active fraction of P. oxalicum MP1 possessed good antioxidant activity as detected using various assays. It also exhibited a strong DNA damage protection potential on pUC19 plasmid DNA treated with Fenton reagent. On exposure to active fraction of MP1 significant reduction (P < 0·05) in nuclear deformities (like nuclear buds, micronuclei, nuclear ridges and binucleated cells) was observed in human lymphocytes pretreated with a toxic concentration of H₂ O₂ . In vivo genoprotectivity studies were conducted in fresh water fish Channa punctatus pretreated with a damaging compound 4-nonyl phenol. The active fraction of P. oxalicum MP1 caused a reduction of 94·7 and 66·60% in micronuclei and aberrant cell formation, respectively. A significant reduction (P < 0·05) in tail length and tail DNA parameters was also observed in comet assay.

CONCLUSION

The endophytic P. oxalicum isolated in this study has the potential to produce metabolites possessing antioxidant and genoprotective activities.

SIGNIFICANCE AND IMPACT OF THE STUDY

The isolated culture can be exploited in the field of therapeutics by virtue of its in vitro and in vivo genoprotective potential.

Chorea as unusual complication of fungicide poisoning

Chorea is a rare manifestation of poisoning. We report an index case of a young woman who developed generalized chorea following propiconazole toxin ingestion. As large series on neurological complications of toxic compounds are difficult to be compiled, it is of interest to report our experience. This report adds one more compound to the increasing list of toxic chorea.

Gepirone hydrochloride: a novel antidepressant with 5-HT1A agonistic properties

Depression is a neuropsychiatric disorder that affects more than 350 million people all over the world. There are psychological and pharmacological treatments for depression which mainly focus on monoaminergic neurotransmission theory. The main concern regarding available antidepressants is the lag period and other side effects, such as sexual dysfunction. Gepirone is a drug of the azapirone group which is a 5-HT1A receptor agonist belonging to the buspirone family. Gepirone is under clinical development and has been shown to be more effective than selective serotonin reuptake inhibitors (SSRIs), as this drug treats the psychiatric disorders without causing sexual dysfunction, which limits the use of SSRIs. It possesses greater selectivity for the 5-HT1A receptor than SSRIs. Clinical studies have shown that gepirone has differential action at pre- and postsynaptic 5-HT1A receptors. Gepirone extended-release tablets (gepirone ER, Travivo) showed promising effects in adult outpatients for the treatment of major depressive disorder (MDD) in a double-blind, randomized, placebo-controlled clinical study. Gepirone also showed an antianxiety effect in a placebo-controlled trial in generalized anxiety disorder. Absorption of gepirone is increased when administered with food as there is no substantial change in Cmax and half-life but it significantly increases AUC and mean residence time. Gepirone undergoes first-pass metabolism and its major metabolites are 1- (2-pyrimidinyl)-piperazine (1-PP) and 3-OH-gepirone, both of which are pharmacologically active. In addition to its better efficacy, gepirone is well tolerated and the major adverse effects observed have been nausea, dizziness and lightheadedness. Evidence from preclinical and clinical studies revealed that gepirone could be a breakthrough therapeutic agent in the treatment of anxiety and MDD.

A Survey of Efficient Trust Management Schemes in Mobile Ad-Hoc Network

Mobile Ad Hoc Networks (MANETs) are comprised of an arrangement of self-sorting mobile hosts furnished with wireless interaction devices gathered in groups without the need of any settled framework as well as centralized organization to maintain a system over radio connections. Every mobile node can react as a host and also, the router freely utilizes the wireless medium inside the correspondence range to deal with the interaction between huge quantities of individual mobile nodes by framing a correspondence system and trading the information among them without using any described group of the base station. A trust-based model in MANET estimates and sets up trust relationship among objectives. Trust-based routing is utilized to keep away data from different attackers like a wormhole, DOS, black-hole, selfish attack and so forth. Trust can be executed in different steps like reputation, subjective rationale and from the supposition of the neighboring node. A trust estimation approach not just watches the behavior of neighbor nodes, additionally it screens the transmission of the information packet in the identification of the route for exact estimation of trust value. A survey is carried out to find some of the limitations behind the existing works which has been done by the researchers to implement various approaches thus to build the trust management framework. Through the survey, it is observed that existing works focused only on the authenticated transmission of the message, how it transmits packets to the destination node securely using a trust-based scheme. And also, it is observed that the routing approach only focused on the key management issues. Certain limitation observed in the implemented approaches of existing work loses the reliability of framework. Thus, to withstand these issues it is necessary to establish a reliable security framework that protects the information exchanged among the users in a network while detecting various misbehaving attacks among the users. Confidentiality, as well as the integrity of information, can be secured by combining context-aware access control with trust management. The performance parameters should be evaluated with the previous works packet delivery ratio, packet drop, detection accuracy, number of false positives, and overhead.

Toxicological evaluation of metal oxide nanoparticles and mixed exposures at low doses using zebra fish and THP1 cell line

Metal and metal oxide nanoparticles are being used in different industries now-a-days leading to their unavoidable exposure to humans and animals. In the present study, toxicological testing was done using nanoparticles of copper oxide, cerium oxide and their mixture (1:1 ratio) on zebra fish embryos and THP-1 cell line. Zebrafish embryos were exposed to 0.01 μg/ml to 50 μg/ml concentrations of dispersed nanoparticles using a 96 well plate and their effects were studied at different hours post fertilization (hpf) i.e. 0 hpf, 24 hpf, 48 hpf, 72 hpf and 96 hpf respectively. Results showed that copper oxide nanoparticles has drastic effects on the morphology and physiology of zebra fish whereas cerium oxide nanoparticles and mixture of these nanoparticles did not show much of the effects. Comparable results were obtained from in vitro study using human monocyte cell line (THP-1). It is concluded that these nanoparticles may cause toxicological effects to humans and environment.

Abstract P5-18-02: A quantitative centrosomal amplification score (CAS) predicts local recurrence in ductal carcinoma in situ

Background: About 60-80% of ductal carcinoma in situ (DCIS) cases are high-grade (HG) DCIS with an elevated risk of local recurrence (LR) even after a lumpectomy. Patients are often under or over treated due to the lack of accurate recurrence risk prediction models. Current prognostic models such as OncotypeDX and Van Nuys Prognostic Index (VNPI) lack consistency and are limited to a specific subset of patients. Here in this study, we show that the extent of centrosome amplification (CA) in a DCIS lesion can predict the risk of LR after lumpectomy. CA refers to presence of supernumerary or large centrosomes and is a characteristic of pre-invasive lesions, and breast tumors, and promotes erroneous mitoses and chromosomal instability.

Methods: We have pioneered a semi-automated pipeline that integrates immunofluorescence confocal microscopy with digital image analysis and yields a quantitative Centrosomal Amplification Score (CAS) for each patients' tumor sample by evaluating severity and frequency of centrosomal aberrations therein. To this end, we first immunofluorescently stained centrosomes in formalin fixed paraffin embedded resection samples from DCIS patients (discovery cohort n=133 and a validation cohort n=119) using an antibody against γ-tubulin, and co-stained nuclei with DAPI. Next, we imaged the slides and processed the raw 3D image data using IMARIS Biplane 8.2 3D volume rendering software. Finally, we calculated centrosome numbers and volume in ˜250 cells from each patient sample. Using a mathematical algorithm, we generated a composite CAS score for each patient sample by integrating the numerical (CASi) and structural (CASm) aberrations.

Results: We found that DCIS patients with recurrence exhibited higher CAS. Intriguingly, higher CAS was also associated with greater risk of developing ipsilateral breast events [Hazard ratio (HR) =7.58 for discovery cohort and HR=5.8 for validation cohort, p&lt;0.0001] which remained significant (HR=8.5 for discovery and HR=3.39, p&lt;0.0001) after accounting for the confounding factors like age, tumor size, comedo necrosis and radiotherapy. Kaplan Meir survival analysis indicated that high CAS was associated with poor recurrence-free survival (RFS) (p&lt;0.001). For the high and low CAS groups, the 5-year risk of recurrence was 87.5% and 12.5% respectively (p&lt;0.001). In our discovery cohort, a head-to-head comparison of the ability of VNPI and CAS to predict recurrence illuminated that CAS was able to stratify the DCIS group in recurrence and recurrence-free group with much higher significance (p&lt;0.0001) than the Van Nuys Prognostic Index (VNPI) (HRs for CAS- 8.8 vs. VNPI 0.959). Finally, the Harrell's concordance index using SAS PROC PHREG tests yielded that the probability of a patient with poorer/lower RFS to be in the high CAS group is 76.2%.

Conclusion: Our data compellingly show that CAS quantifies the risk of recurrence in DCIS patients with the highest concordance and provides a novel and innovative tool to tailor their treatment based on their risk profile.

Citation Format: Mittal K, Kaur J, Wei G, Toss MS, Osan RM, Janssen EA, Søiland H, Rakha EA, Rida PC, Aneja R. A quantitative centrosomal amplification score (CAS) predicts local recurrence in ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-02.

A comparative study of gloved versus ungloved merocel® as nasal pack after septoplasty

Introduction

Septoplasty or septal reconstruction is a corrective surgical procedure performed to straighten the nasal septum. It may be associated with numerous complications. To minimize these complications, both nasal cavities are frequently packed with different types of nasal packing.

Materials and Methods

This prospective, observational, and comparative study was undertaken in the Department of ENT, Rajindra Hospital, Patiala, Punjab, India. A total of sixty patients fulfilling the inclusion criteria participated in the study. They were divided into two groups, Groups A and B. After septoplasty, the nasal cavity was packed with gloved Merocel^® in Group A and ungloved Merocel^® in control group (Group B). The efficacy and patient tolerance for both nasal packings were compared and assessed. The data collected were compiled and analyzed statistically.

Results

In our study, it was demonstrated that gloved Merocel^® produces less pain during pack insertion (P = 0.001) and produces less pain while insertion of pack in situ (P = 0.001) and during pack removal (P = 0.001). Saccharin transit time (STT) returned back to normal in gloved Merocel^® group (P = 0.001) in most of patients (27) by the 2^nd week, whereas STT in ungloved Merocel^® group returned back to normal by the 4^th week postoperatively. The differences in impairment in STT between the two groups were found to be statistically significant. There was no statistical significance between both groups for other parameters.

Conclusion

Gloved Merocel^® may be preferred over ungloved Merocel^® as nasal packing following septoplasty since both types of packs had similar hemostatic, adhesion prevention properties and similar incidence in postoperative complications and gloved Merocel^® produces less pain during its insertion, while it is in situ, during its removal with early recovery of nasal mucociliary clearance mechanism of nose.

Exploration of insecticidal potential of an alpha glucosidase enzyme inhibitor from an endophytic Exophiala spinifera

AIM

The present study aimed to isolate and screen endophytes from Trachyspermum ammi with the ability to inhibit alpha glucosidase enzyme and evaluate their insecticidal potential.

METHODS AND RESULTS

Endophytic fungi isolated from T. ammi were screened for alpha glucosidase inhibitory activity. Maximum inhibition (96%) was observed in an isolate AZ-9, identified to be Exophiala spinifera on morphological and molecular basis. Production of fungal metabolites was carried out in malt extract broth followed by extraction with ethyl acetate. Brown coloured gummy residue obtained after evaporation of ethyl acetate was partially soluble in water yielding white precipitates. The precipitate exhibiting α-glucosidase inhibitory activity was purified by repeated washing and centrifugation. The insecticidal activity of inhibitor was evaluated on Spodoptera litura (Fab.) by feeding this pest on diet amended with inhibitor. It resulted in significant larval mortality as well as deformities in emerging adults. A reduction in vivo digestive enzyme activity was also observed. Nutritional analysis revealed the toxic effect of AZ-9 inhibitor on various food utilization parameters of S. litura. A significant reduction was recorded in relative growth and consumption rate of S. litura.

CONCLUSIONS

This is the first report on production of an alpha glucosidase inhibitor from E. spinifera with insecticidal activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study highlights the importance of endophytes in providing protection against insect pests to the host. It also suggests the insecticidal potential of alpha glucosidase inhibitor from E. spinifera against polyphagous pest S. litura.