Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Scaling mechanical instabilities in drying micellar droplets

Drying-induced mechanical instabilities in aqueous solution droplets occur primarily because, during evaporation, the central liquid minimizes the surface tension by pulling the packed gel-like region, leading to a stretching effect of the liquid region at the receding wet front. Under an appropriate scenario, it finally perturbs the gel-like zone at the droplet periphery, generating cracks, wrinkles, folds, cavities, buckles, etc. Here we report unique wrinkling patterns from evaporating sessile micellar aqueous droplets on rigid and soft substrates kept at temperatures well above the ambient. The wrinkling patterns remarkably vary depending on the material's elastic modulus and substrate, the concentration of the micellar solution (C_CTAB), and the substrate temperature (T_S). In the low concentration regime (C_CTAB ≤ 0.0364 wt%), coffee-ring-like morphologies are observed devoid of any wrinkling morphology irrespective of T_S and the substrate's elastic modulus. In the high initial concentration regime (C_CTAB ≥ 0.0364 wt%), for droplets deposited at T_S ≥ 85 °C, wrinkle formation starts at the droplet peripheral zone, radial on the stiff glass substrate, and annular on the soft cross-linked PDMS substrate. At C_CTAB ≥ 2.73 wt%, radial wrinkles on the glass substrate and annular wrinkles on the cross-linked PDMS substrate nucleate from the edges connecting to the central region of the deposit. The ratio between the width of the gel-like deposit (or wrinkle length) and the droplet's radius scales with the initial concentration of the surfactant and depends on the initial equilibrium contact angle of the micellar droplets. Our results support existing understandings of mechanical instabilities of dried deposits, which satisfies interdependent scaling relationships among their number, lengthscale (dried deposit radius, the wavelength of the wrinkles, and peripheral undulations from Rayleigh-Bénard instability), thickness, and elastic modulus. Interestingly, we found substrate-dependent antagonistic interdependence of the elastic modulus of the dried deposit with the initial surfactant concentration.

Innovation in regulatory approaches for endocrine disrupting chemicals: The journey to risk assessment modernization in Canada

Globally, regulatory authorities grapple with the challenge of assessing the hazards and risks to human and ecosystem health that may result from exposure to chemicals that disrupt the normal functioning of endocrine systems. Rapidly increasing number of chemicals in commerce, coupled with the reliance on traditional, costly animal experiments for hazard characterization - often with limited sensitivity to many important mechanisms of endocrine disruption -, presents ongoing challenges for chemical regulation. The consequence is a limited number of chemicals for which there is sufficient data to assess if there is endocrine toxicity and hence few chemicals with thorough hazard characterization. To address this challenge, regulatory assessment of endocrine disrupting chemicals (EDCs) is benefiting from a revolution in toxicology that focuses on New Approach Methodologies (NAMs) to more rapidly identify, prioritize, and assess the potential risks from exposure to chemicals using novel, more efficient, and more mechanistically driven methodologies and tools. Incorporated into Integrated Approaches to Testing and Assessment (IATA) and guided by conceptual frameworks such as Adverse Outcome Pathways (AOPs), emerging approaches focus initially on molecular interactions between the test chemical and potentially vulnerable biological systems instead of the need for animal toxicity data. These new toxicity testing methods can be complemented with in silico and computational toxicology approaches, including those that predict chemical kinetics. Coupled with exposure data, these will inform risk-based decision-making approaches. Canada is part of a global network collaborating on building confidence in the use of NAMs for regulatory assessment of EDCs. Herein, we review the current approaches to EDC regulation globally (mainly from the perspective of human health), and provide a perspective on how the advances for regulatory testing and assessment can be applied and discuss the promises and challenges faced in adopting these novel approaches to minimize risks due to EDC exposure in Canada, and our world.

Cationic surfactant-directed structural control of NaCl crystals from evaporating sessile droplets

We report morphological regulation of NaCl (sodium chloride) crystals through the evaporative crystallisation process of microdroplets containing a cationic surfactant CTAB (cetyltrimethylammonium bromide). Various fascinating evaporative salt morphologies are observed using different combinations of salt (C_NaCl) and surfactant (C_CTAB) concentrations. Each observed morphology is carefully explained by the interplaying physical phenomena, such as crystallisation, micellisation, evaporative dewetting, and surface adsorption of anionic couneterions. Salt morphologies are investigated for low (C_NaCl = 0.1 (M)), intermediate (C_NaCl = 0.5 (M)) and high (C_NaCl = 2 (M)) concentrations, whereas surfactant concentrations are varied four orders of magnitudes (from 0.0001 (M) to 0.1 (M)). Interestingly, we observe a threshold in C_CTAB at 0.001 (M), beyond which the peripheral rings of dried deposits are found to be composed of CTAB for C_NaCl = 0.1 (M), while the same is seen to be made up of NaCl for C_NaCl = 2 (M). We have explained the morphological evolution by the process of competitive surface adsorption phenomenon between Cl^- and Br^- counter ions. Such a detailed study of saline droplet crystallisation in the presence of a cationic surfactant underpins the fundamental understanding of the crystallisation process. In addition, it may further impact application sectors where crystallisation of saline solution plays an important role, especially in the presence of additives.

AB0265 OPIOIDS AND ANALGESIC USE IN EARLY RHEUMATOID ARTHRITIS: A LONGITUDINAL ANALYSIS OF LINKED REAL-WORLD PRESCRIPTION DATA

Background:

Large numbers of patients with rheumatoid arthritis (RA) receive regular opioids despite significant toxicity and a lack of evidence supporting their use in non-cancer pain. In order to address this situation, we need to understand when opioids are started in early RA where this has not been studied.

Objectives:

To examine the temporal trend of opioid prescriptions before and after RA symptom onset and to compare this with DMARD and NSAID prescriptions.

Methods:

RA participants (cases) were recruited as part of the Scottish Early Rheumatoid Arthritis (SERA) inception cohort1. Controls without RA (five per case), matched for sex, age and post code over the same time period, were obtained through routine data linkage. Prescription data between Jan 2009 to Nov 2019 of cases and matched controls were compared using date of RA symptom onset as reference point. The Prescriptions Per Participant (PPP) for each three-month block was estimated by dividing the number of prescribed drugs in the selected drug classes (assigned using the British National Formulary) in that time block by the number of participants in each group. The differences between mean PPP of the RA cases and controls in each time block were tested by t-test for independent groups and subsequent adjustment for multiple testing.

Results:

1,720,335 prescriptions were available for analysis with 421,961 items for 950 RA cases and 1,299,374 items for 4,558 matched controls. As expected, DMARD prescriptions in the SERA cases increased after the symptom onset period and were then sustained (Figure 1: top left panel). NSAID prescriptions in RA cases peaked during the 3 months after symptom onset and then reduced progressively (top right panel). Opioid analgesic prescriptions for the RA cases increased two-fold during the reference period and then reduced 6-9 months post-symptom onset. However, unlike NSAIDs, after this there was no further significant reduction in opioid prescriptions in the RA cases, which remained stable and significantly higher than in the controls for the remaining study period. The non-opioid analgesic mean PPP increased sharply at the time of symptom onset, with a steady gradual upward trend over time (lower right panel).

Conclusion:

Opioid prescriptions increase significantly at the time of RA symptoms onset. Despite rapid introduction of DMARDs and resultant reductions in NSAIDs, analgesic use remains significantly higher than in controls. Further research is required to identify the factors associated with persistent opioid use in early RA with interventions aimed at the first 6 months.

References:

[1]Dale et al. BMC Musculoskelet Disord. 2016;17:461.

Acknowledgements:

The work was supported by Health Data Research UK which receives its funding from HDR UK Ltd funded by the UKRI MRC, EPSRC, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientists Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation (BHF) and the Wellcome Trust.

The SERA study was jointly funded by the Chief Scientists Office Scotland and Pfizer Ltd.

Disclosure of Interests:

None declared

Mercury and neurochemical biomarkers in multiple brain regions of five Arctic marine mammals

Mercury is a neurotoxic chemical that represents one of the greatest pollution threats to Arctic ecosystem health. Evaluating the direct neurotoxic effects of mercury in free ranging wildlife is challenging, necessitating the use of neurochemical biomarkers to assess potential sub-clinical neurological changes. The objective of this study was to characterize the distribution and speciation of mercury, as well as exposure-associated changes in neurochemistry, across multiple brain regions (n = 10) and marine mammal species (n = 5) that each occupy a trophic niche in the Arctic ecosystem. We found consistent species differences in mean brain and brain region-specific concentrations of total mercury (THg) and methyl mercury (MeHg), with higher concentrations in toothed whales (narwhal, pilot whales and harbour porpoise) compared to fur-bearing mammals (polar bear and ringed seal). Mean THg (μg/g dw) in decreasing rank order was: pilot whale (11.9) > narwhal (7.7) > harbour porpoise (3.6) > polar bear (0.6) > ringed seal (0.2). The higher THg concentrations in toothed whales was associated with a marked reduction in the percentage of MeHg (<40 %) compared to polar bears (>70 %) that had lower brain THg concentrations. This pattern in mercury concentration and speciation corresponded broadly to an overall higher number of mercury-associated neurochemical biomarker correlations in toothed whales. Of the 226 correlations between mercury and neurochemical biomarkers across brain regions, we found 60 (27 %) meaningful relationships (r>0.60 or p < 0.10). We add to the growing weight of evidence that wildlife accumulate mercury in their brains and demonstrate that there is variance in accumulation across species as well as across distinct brain regions, and that some of these exposures may be associated with sub-clinical changes in neurochemistry.

OP0255-PARE USING AN EDUCATIONAL APPLICATION TO FACILITATE UNDERSTANDING OF THE ANATOMY AND FUNCTION OF THE BRAIN AND TO EXPLORE THE EFFECTS OF CLINICAL FATIGUE FROM A PATIENT PERSPECTIVE

Background:

Rheumatic and musculoskeletal diseases are a group of devastating autoimmune disorders that all commonly share the debilitating symptom of fatigue. Despite the fact that fatigue can often cause some of the greatest impairments to quality of life, it is frequently reported by patients as the least successfully managed symptom of these conditions.

Fatigue is routinely misunderstood within the general population, with many people using the word fatigue as a synonym for tired. Fatigue is not the same as tiredness, which is a normal state that is experienced by most of the population, therefore it is important to help the general public understand what fatigue actually is and how it imposes consequences and limitations on those who suffer from it. To aid this understanding an educational application has been created to reinforce the patient perspective of living with fatigue. Furthermore, this application will also aid the understanding of brain anatomy and function, using Augmented Reality (AR), as research has now shown that brain function may be altered in the state of fatigue.

Currently, educational AR applications show great potential for increasing comprehension and understanding of complex concepts. AR expands user engagement by enhancing the learner’s enjoyment and enriching their learning environment. We hope to utilise this technology in the education of fatigue.

Objectives:

We aimed to create an AR application that has informative content designed to educate users on the topics of basic brain anatomy and function. Furthermore, we aimed to increase the users understanding of the complete impairment of fatigue by creating a short video that describes living with fatigue from the patient’s perspective.

Methods:

The application was created using medical scan dataset, a variety of 3D modelling software, and a game engine to create a functional and interactive augmented application. The short video regarding a patient’s perspective on living with fatigue was developed in collaboration with the Glasgow Arthritis Involvement Network patient partners. In order to determine if the application met its primary objectives a pilot test was conducted on 14 participants. After consenting to taking part in the study, individuals were guided through a pre-application test, the use of the application itself and finally a post-application test.

Results:

Initial results from the pilot test showed promise in the educational potential of the application. With regards to the questions pertaining to the brain anatomy, the percentage of questions answered correctly increased from 36% in the pre-test to 60% in the post-test. Furthermore, after using the application the participants reported a significant increase in their confidence for their answers. An additional six questions ascertained a participants perceptions of fatigue. From these questions, the answer that was most significantly changed after use of the application, was in relation to the impact that fatigue has on a patient’s quality of life (t-Test p=0.02). After use of the application participants’ opinions changed to reflect the fact that fatigue can completely impair a person’s quality of life, showing an increase in their understanding of the debilitating nature of fatigue.

Conclusion:

This research explored the development and effectiveness of an AR application that was centered around fatigue and basic neuroanatomy education within the general population. From the pilot test conducted we are able to report that the application was successful in delivering educational material about brain anatomy and was successful in increasing awareness about the impact that fatigue can have on an individual’s quality of life.

Figure 1.

Augmented brain model scene using brain model as trigger

Figure 2.

Example of material change upon selection of Occipital Lobe option

Acknowledgments:

The Glasgow Arthritis Involvement Network (GAIN)

Disclosure of Interests:

None declared

Improving quality of life in vasculitis patients

Systemic vasculitis are a complex cluster of diseases with high associated morbidity. As disease-related mortality diminishes, the cumulative impact of poor health-related quality of life becomes more pertinent to patients than the initial pathological insult. In this article we explore health-related quality of life in ANCA-associated vasculitis, large-vessel vasculitis and therapeutic strategies that may enhance this critical outcome.

T11TS immunotherapy augments microglial and lymphocyte protective immune responses against Cryptococcus neoformans in the brain

Cryptococcus neoformans, the encapsulated yeast acquired through inhalation, remains localized in lungs, but harbours the CNS in immunocompromised individuals. Several treatment regimes have failed combating this disease totally, but long-term usage of drugs leads to organ damage. As T11-target structure (T11TS) has documented profound immune potentiation, we aimed to investigate the role of microglia, pivotal immune cells of brain in ameliorating cryptococcosis, with T11TS immunotherapy. Murine model with C neoformans infection was prepared by intraperitoneal injection and the brains of rats examined 7 days post-infections for histopathology by PAS and Alcian blue staining corroborated with organ fungal burden evidencing restorative T11TS action on Cryptococcal meningitis. Immunotherapy with three doses of T11TS, a CD2 ligand, in C neoformans infected rats, upregulates toll-like receptors 2, -4 and -9 of microglia, indicating increased phagocytosis of the fungus. Flowcytometric analysis revealed increased numbers of T11TS treated brain infiltrating CD4⁺ and CD8⁺ T-lymphocytes along with increased MHC I and MHC II on microglia, activating the infiltrating lymphocytes aiding the killing mechanism. Present study also indicated that T11TS increased production of Th1 inflammatory cytokines conducive to fungal elimination while the inhibitory Th2 cytokines were dampened. This preclinical study is first of its kind to show that T11TS effected profound immune stimulation of microglial activity of C neoformans infected rats eradicating residual fungal burden from the brain and can be a useful therapeutic strategy in fighting against this deadly disease.

Morphology modulation in evaporative drying mediated crystallization of sodium chloride solution droplet with surfactant

We report the evaporative drying of an aqueous droplet containing a dilute solution of sodium chloride (NaCl) on a hydrophobic substrate made of cross-linked poly-dimethyl siloxane (PDMS). The salt concentration Cn was varied between 0.08 molar (M) and 2.0 M. The contact line of the evaporating droplets shows significant initial retraction for all Cn, before they get pinned. While the final morphology comprises a few small NaCl crystals deposited around the pinned contact line, in droplets with a low Cn (<0.5 M), it transforms to a single large salt crystal when Cn > 0.7 M with no peripheral deposition. We further show that the deposition morphology drastically changes when an anionic surfactant, sodium dodecyl sulfate (SDS), is added into the salt-solutions. Even in the surfactant-laden droplets, the final deposition morphology changes significantly as a function of Cn. It transforms from a thick SDS ring surrounding a fractal-like deposit of NaCl crystallites at lower Cn to a peripheral deposit of NaCl crystals at higher Cn due to competition between micelle formation and crystallization. However, the crystallographic orientation of the deposited NaCl crystals remains unaltered irrespective of the presence of surfactant.

Prognosis and future developments in vasculitis

The prognosis of ANCA-associated vasculitis has been transformed in recent years. Once it was a set of invariably acute and fatal conditions, but these disorders are currently considered to be chronic diseases. This change is largely attributable to earlier diagnosis and the careful application of immunotherapeutics. However, patients still experience premature mortality, relapse, comorbid ill health and poor quality of life. Mortality rates in large-vessel vasculitis are not comparable; however, morbidity and poor patient outcomes prevail. Toxicity secondary to glucocorticoids represents a common driver of poor outcomes across systemic vasculitis. The main thrust of future treatment strategies is to reduce if not eliminate exposure to these agents.

Insecticide susceptibility status of Phlebotomus argentipes and polymorphisms in voltage-gated sodium channel (vgsc) gene in Kala-azar endemic areas of West Bengal, India

Rational use of insecticides, as advocated by World Health Organisation, plays a crucial role for vector control in eliminating visceral leishmaniasis from endemic countries. Emergence and spread of resistance among vector sand flies is of increasing concern for achieving these goals. Information on insecticide susceptibility status of sand fly populations and potential association between the former and polymorphisms in the insecticide target genes is important for formulating proper vector control measures. The present study was designed to evaluate the susceptibility status of vector sand fly species (Phlebotomus argentipes) against deltamethrin (type II pyrethroid), DDT (organochlorine) and malathion (organophosphate) and to detect polymorphisms in voltage gated sodium channel (vgsc) gene and investigating their association with type II pyrethroid and DDT susceptibility in three Kala-azar endemic districts of West Bengal, India. Adult sand flies were collected from human dwelling and cattle sheds of the study areas and subjected to insecticide bioassay using insecticide impregnated papers as per WHO protocol. Polymorphisms in domain II segment 6 of vgsc gene of pyrethroid and DDT susceptible and tolerant P. argentipes were detected by DNA sequencing. P. argentipes population of the study area was found to be susceptible to deltamethrin and malathion with corrected mortality rate between 98.02% to 98.80% and 98.81% to 100% respectively, but resistant to DDT (corrected mortality rate = 65.62%-76.33%). Two non-synonymous mutations L1014S and L1014F were detected of which L1014F was found to be associated with deltamethrin/DDT resistance. The replacement of DDT by synthetic pyrethroid is aptly done by national vector borne disease control programme (NVBDCP). The prevalence of L1014F mutation in vgsc gene and its association with type II pyrethroid tolerability is an indication of emergence of resistance against it. Malathion may be used as an alternative in the study areas if needed in future. Similar studies at a regular interval are highly suggested for monitoring susceptibility of used insecticide and to detect early signs of emergence of resistance against them.

Polymorphisms in voltage-gated sodium channel gene and susceptibility of Aedes albopictus to insecticides in three districts of northern West Bengal, India

Background

The control and prevention of dengue largely depends on vector control measures, environmental management, and personal protection. Dengue control programmes are facing great challenges due to development of insecticide resistance among vector mosquitoes. Information on susceptibility status to different insecticides is important for national programmes to formulate vector control strategies.

Methods

We have studied the larval susceptibility of Aedes albopictus to temephos and adult susceptibility to 4% DDT, 0.05% deltamethrin, and 5% malathion as per WHO protocols in the northern districts of West Bengal. Polymorphisms in the VGSC gene were studied by direct sequencing of PCR products.

Results

The Ae. albopictus larval population showed sensitive [Resistance Ratio (RR₉₉)<3] to moderate levels of resistance (5<RR₉₉>10) to temephos at different study sites. Adult bioassay results revealed that Ae. albopictus was highly resistant to DDT [Corrected Mortality (CM) < 90%] in all the study sites and susceptible to deltamethrin and malathion (CM > 98%), except in Dhupguri where a low level of resistance to deltamethrin (CM = 96.25%) was recorded. None of the six important kdr mutations (S953P, I975M/V, L978, V980G, F1474C, D1703Y) were found in the VGSC of studied mosquitoes, but we identified 11 synonymous and 1 non-synonymous mutation in the VGSC gene.

Conclusion

The higher susceptibility level to deltamethrin and malathion, along with the absence of important kdr mutations indicates that these two insecticides are still effective against Ae. albopictus in the study areas. The susceptibility status of temephos should be monitored closely as low to moderate levels of resistance were observed in few sites. A similar study is recommended for monitoring and early detection of insecticide resistance in other parts of the country.

Dengue is one of the most important arboviral infections in India, and transmitted by Aedes mosquitoes. Control of dengue largely depends on effective vector control measures as no specific drugs or vaccines are available, to date. The knowledge of insecticide susceptibility status for local vector mosquitoes is essential for the formulation of effective vector control measures. Therefore, regular monitoring of insecticide susceptibility is essential for the early detection of resistance. In the present study, sensitive to moderate levels of resistance to temephos were recorded among the Aedes albopictus larval populations of different study sites. Adult Ae. albopictus were highly resistant to DDT and susceptible to deltamethrin and malathion in all the study sites, except one site where a low level of resistance to deltamethrin was observed. By sequencing the VGSC gene we observed that the studied Ae. albopictus population does not contain any of the important kdr mutations which are associated with DDT and pyrethroid resistance in other insects. We found only one non-synonymous mutation at codon S1485L, but its role in pyrethroid resistance is yet to be established.

An ecotoxicological view on neurotoxicity assessment

The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.

Correlation of altered expression of a long non-coding RNA, NEAT1, in peripheral blood mononuclear cells with dengue disease progression

The association of long non-coding RNAs (lncRNAs) with dengue disease progression is currently unknown. Therefore, the present study aimed to identify lncRNAs in different categories of dengue patients and evaluate their association with dengue disease progression. Herein, we examined the expression profiles of lncRNAs and protein-coding genes between other febrile illness (OFI) and different grade of dengue patients through high-throughput RNA sequencing. We identified Nuclear Enriched Abundant Transcript 1 (NEAT1) as one of the differentially expressed lncRNAs (adjusted P ≤ 0.05 and log-fold change ≥ 2) and subsequently validated the expression by qRT-PCR. The co-expression analysis further revealed that NEAT1 and the coding gene IFI27 were highly co-expressed and negatively correlated with dengue severity. Using regression analysis, we observed that NEAT1 expression was significantly dependent on disease progression (Coefficient = -0.27750, SE Coefficient = 0.07145, and t = -3.88).Further, receiver operating characteristic (ROC) curve revealed that NEAT1 expression could discriminate DI from DS (sensitivity and specificity of 100% (95%CI: 85.69 - 97.22) and area under the curve (AUC) = 0.97). Overall, the results of this study offer the first experimental evidence demonstrating the correlation between lncRNAs and severe dengue phenotype. Monitoring NEAT1and IFI27 expression in PBMC may be useful in understanding dengue virus-induced disease progression.

RNA-Seq analysis of peripheral blood mononuclear cells reveals unique transcriptional signatures associated with disease progression in dengue patients

Patients infected with Dengue virus usually present a mild, self-limiting febrile dengue infection (DI) that occasionally leads to a potentially lethal complication, called the severe dengue (DS). The ability to identify the prognostic markers of DS could allow an improved disease intervention and management. To identify the transcriptional signatures associated with the dengue disease progression, we carried out the high-throughput sequencing of the RNA isolated from the peripheral blood mononuclear cells (PBMCs) of the dengue patients of varying severity and compared with that in the patients with other febrile illnesses (OFIs) or the healthy controls. The transcriptional signatures that discriminated the DS patients from OFI and DI patients were broadly related to the pathways involving glycine, serine, and threonine metabolisms, extracellular matrix organization, ubiquitination, and cytokines and inflammatory response. Several upregulated genes in the inflammatory process (MPO, DEFA4, ELANE, AUZ1, CTSG, OLFM4, SLC16A14, and CRISP3) that were associated with the dengue disease progression are known to facilitate leukocyte-mediated migration, and neutrophil activation and degranulation process. High activity of MPO and ELANE in the plasma samples of the follow-up and recovered dengue patients, as well as and the presence of a larger amount of cell-free dsDNA in the DS patients, suggested an association of neutrophil-mediated immunity with dengue disease progression. Careful monitoring of some of these gene transcripts, and control of the activity of proteins encoded by them, may have a great translational significance for the prognosis and management of the dengue patients.

Asymptomatic leishmaniasis in kala-azar endemic areas of Malda district, West Bengal, India

Asymptomatic leishmaniasis may drive the epidemic and an important challenge to reach the goal of joint Visceral Leishmaniasis (VL) elimination initiative taken by three Asian countries. The role of these asymptomatic carriers in disease transmission, prognosis at individual level and rate of transformation to symptomatic VL/Post Kala-azar Dermal Leishmaniasis (PKDL) needs to be evaluated. Asymptomatic cases were diagnosed by active mass survey in eight tribal villages by detecting antileishmanial antibody using rK39 based rapid diagnostic kits and followed up for three years to observe the pattern of sero-conversion and disease transformation. Out of 2890 total population, 2603 were screened. Antileishmanial antibody was detected in 185 individuals of them 96 had a history of VL/PKDL and 89 without such history. Seventy nine such individuals were classified as asymptomatic leishmaniasis and ten as active VL with a ratio of 7.9:1. Out of 79 asymptomatic cases 2 were lost to follow up as they moved to other places. Amongst asymptomatically infected persons, disease transformation in 8/77 (10.39%) and sero-conversion in 62/77 (80.52%) cases were noted. Seven (9.09%) remained sero-positive even after three years. Progression to clinical disease among asymptomatic individuals was taking place at any time up to three years after the baseline survey. If there are no VL /PKDL cases for two or more years, it does not mean that the area is free from leishmaniasis as symptomatic VL or PKDL may appear even after three years, if there are such asymptomatic cases. So, asymptomatic infected individuals need much attention for VL elimination programme that has been initiated by three adjoining endemic countries.

A total of 79 asymptomatic VL cases were detected from two kala-azar endemic blocks of Malda districts of West Bengal by active mass screening. Follow study of the asymptomatic cases revealed that 10.39% cases transformed into disease and 9.09% cases remained as sero-positive even after three years. So progression to clinical disease among asymptomatic individuals was taking place at any time up to three years after the baseline survey. Therefore, in a given period if there are no cases of VL/PKDL for two or more years, it does not mean that the area is free from leishmaniasis as symptomatic VL or PKDL may appear even after three years, if there are such asymptomatic cases. So, asymptomatic infected individuals need much attention for VL elimination programme that has been initiated by three adjoining endemic countries.

Polymorphisms in Pfcrt and Pfmdr-1 genes after five years withdrawal of chloroquine for the treatment of Plasmodium falciparum malaria in West Bengal, India

BACKGROUND

The emergence of resistant power against different antimalarial agents particularly by Plasmodium falciparum is a challenge to combat malaria. Regular monitoring is essential not only to determine the efficacy and development of resistance by the parasite but also to detect early sign of regaining sensitivity to any anti-malarial agent that has been withdrawn for a long period. Studies on molecular markers associated with antimalarial drug resistance of prevailing Plasmodium population play an important role in this aspect. The present protocol was designed to study the polymorphisms in pfcrt and pfmdr-1 gene to determine any sign of regaining sensitivity to chloroquine among P. falciparum after five years of artemisinin combination therapy (ACT) implementation.

METHODS

Clinical isolates were collected from P. falciparum positive patients attending the malaria clinic of Calcutta School of Tropical Medicine during December 2014 to December 2015. Genomic parasitic DNA was extracted and subjected to sequencing of pfcrt and pfmdr-1 gene directly from purified PCR products.

RESULTS

A total of 89 isolates were sequenced for pfcrt and 73 isolates for pfmdr-1 genes. In pfcrt gene mutant K76T was detected in all isolates and all were SVMNT haplotype. Out of three important polymorphisms in pfmdr-1 gene mutant Y184F was detected among all isolates. One synonymous G182G and one non-synonymous S232F/Y, mutation were detected in 99% isolates.

CONCLUSION

All isolates carrying mutant K76T in pfcrt gene, considered as hall mark for CQ resistance, indicate that there is no sign of regaining CQ sensitivity among the prevailing P. falciparum population of the study area after five years of ACT implementation.

Cholinesterase and monoamine oxidase activity in relation to mercury levels in the cerebral cortex of wild river otters

Mercury (Hg) is a global pollutant that is neurotoxic to many mammalian species. The present study was conducted to determine if the bioaccumulation of Hg by wild river otters ( Lontra canadensis) could be related to variations in the activities of key neurochemical enzymes. River otters were collected from Ontario and Nova Scotia (Canada) during the trapping seasons, spanning 2002-2004, and their brains were dissected into the cerebral cortex and cerebellum. The activities of cholinesterase (ChE) and monoamine oxidase (MAO) were measured from each sample and correlated with concentrations of brain Hg from the same animal. Significant negative correlations were found between concentrations of brain Hg and ChE (total Hg: r= -0.42; MeHg: r= -0.33) and MAO (total Hg: r= -0.31; MeHg: r= -0.42) activity in the cerebral cortex. The scatterplots relating concentrations of brain Hg and enzyme activity in the cerebral cortex were wedge-shaped, and could be fitted with quantile regression modeling, suggesting that Hg may act as a limiting factor for ChE and MAO activity. No relationships were found in the cerebellum. These data suggest that environmentally relevant concentrations of Hg may influence the activities of ChE and MAO in the cerebral cortex of river otters, and by extension, other fish-eating mammals.

The influence of anisotropic nano- to micro-topography on in vitro and in vivo osteogenesis

AIM

Topographically modified substrates are increasingly used in tissue engineering to enhance biomimicry. The overarching hypothesis is that topographical cues will control cellular response at the cell-substrate interface.

MATERIALS & METHODS

The influence of anisotropically ordered poly(lactic-co-glycolic acid) substrates (constant groove width of ~1860 nm; constant line width of ~2220 nm; variable groove depth of ~35, 306 and 2046 nm) on in vitro and in vivo osteogenesis were assessed.

RESULTS & DISCUSSION

We demonstrate that substrates with groove depths of approximately 306 and 2046 nm promote osteoblast alignment parallel to underlined topography in vitro. However, none of the topographies assessed promoted directional osteogenesis in vivo.

CONCLUSION

2D imprinting technologies are useful tools for in vitro cell phenotype maintenance.

Differential Expression and Significance of Circulating microRNAs in Cerebrospinal Fluid of Acute Encephalitis Patients Infected with Japanese Encephalitis Virus

Changes in circulating microRNAs (miRNAs) in the cerebrospinal fluid (CSF) have been associated with different neurological diseases. Here, we presented results of a pilot study aimed at determining the feasibility of detecting miRNAs in the CSF of Japanese Encephalitis virus (JEV) infected individuals with acute encephalitis syndrome (AES). We demonstrated the circulating miRNA profile in CSF of acute encephalitis patients infected with JEV. Using a quantitative real-time PCR-based miRNA array, we examined the level of 87 miRNAs expressed in human exosomes isolated from CSF. Subsequently, correlation between cytokine level and miRNAs expression in CSF samples was examined. In this study, we identified and validated the upregulated expression of three miRNAs, miR-21-5p, miR-150-5p, and miR-342-3p that were specifically circulated in CSF of acute encephalitis patients infected with JEV. CSF miR-21-5p, miR-150-5p, and miR-342-3p expressions were also elevated in infected mice brain. However, the expression pattern of these miRNAs differed in neuronal cells, microglial cells, and the exosome derived from JEV-infected cell culture supernatant. Interestingly, neuronal cells infected with vaccine strain (SA-14-14) did not lead to any upregulation of these three miRNAs. Further, miR-150-5p expression was found to be negatively correlated(r = -0.5279, p = 0.016) with TNFα level. Pathway analysis of putative target genes of these miRNAs indicated involvement of TGF-β, NGF, axon guidance, and MAPK signaling pathways in JEV/AES patients. This study for the first time represents the circulating miRNA in CSF of AES patients and identified the upregulated miRNAs in JEV-infected patients and offers the basis for future investigation.

Uptake of selenium and mercury by captive mink: Results of a controlled feeding experiment

Captive, juvenile, ranch-bred, male mink (Neovison vison) were fed diets containing various concentrations of methyl-mercury (MeHg) and selenium (Se) for a period of 13 weeks and then sacrificed to determine total Hg levels in fur, blood, brain, liver and kidneys and total Se concentrations in brain tissue. As MeHg concentrations in the diet increased, concentrations of total Hg in the tissues also increased with the highest level occurring in the fur > liver = kidney > brain > blood. Concentrations of Hg in the fur were correlated (r(2) > 0.97) with liver, kidney, blood and brain concentrations. The addition of Se to the mink diet did not appear to affect most tissue concentrations of total Hg nor did it affect the partitioning of Hg between the liver:blood, kidney:blood and brain:blood; however, partitioning of Hg between fur and blood was apparently affected.

Controlling droplet-based deposition uniformity of long silver nanowires by micrometer scale substrate patterning

We report control of droplet-deposit uniformity of long silver nanowires suspended in solutions by microscopic influence of the liquid contact line. Substrates with microfabricated line patterns with a pitch far smaller than mean wire length lead to deposit thickness uniformity compared to unpatterned substrates. For high boiling-point solvents, two significant effects were observed: The substrate patterns suppressed coffee ring staining, and the wire deposits exhibited a common orientation lying perpendicular over top the lines. The latter result is completely distinct from previously reported substrate groove channeling effects. This work shows that microscopic influence of the droplet contact line geometry including the contact angle by altered substrate wetting allows significant and advantageous influence of deposition patterns of wire-like solutes as the drop dries.

Substrate topography: A valuable in vitro tool, but a clinical red herring for in vivo tenogenesis

Controlling the cell-substrate interactions at the bio-interface is becoming an inherent element in the design of implantable devices. Modulation of cellular adhesion in vitro, through topographical cues, is a well-documented process that offers control over subsequent cellular functions. However, it is still unclear whether surface topography can be translated into a clinically functional response in vivo at the tissue/device interface. Herein, we demonstrated that anisotropic substrates with a groove depth of ∼317nm and ∼1988nm promoted human tenocyte alignment parallel to the underlying topography in vitro. However, the rigid poly(lactic-co-glycolic acid) substrates used in this study upregulated the expression of chondrogenic and osteogenic genes, indicating possible tenocyte trans-differentiation. Of significant importance is that none of the topographies assessed (∼37nm, ∼317nm and ∼1988nm groove depth) induced extracellular matrix orientation parallel to the substrate orientation in a rat patellar tendon model. These data indicate that two-dimensional imprinting technologies are useful tools for in vitro cell phenotype maintenance, rather than for organised neotissue formation in vivo, should multifactorial approaches that consider both surface topography and substrate rigidity be established.

STATEMENT OF SIGNIFICANCE

Herein, we ventured to assess the influence of parallel groves, ranging from nano- to micro-level, on tenocytes response in vitro and on host response using a tendon and a subcutaneous model. In vitro analysis indicates that anisotropically ordered micro-scale grooves, as opposed to nano-scale grooves, maintain physiological cell morphology. The rather rigid PLGA substrates appeared to induce trans-differentiation towards chondrogenic and/or steogenic lineage, as evidence by TILDA gene analysis. In vivo data in both tendon and subcutaneous models indicate that none of the substrates induced bidirectional host cell and tissue growth. Collective, these observations indicate that two-dimensional imprinting technologies are useful tools for in vitro cell phenotype maintenance, rather than for directional neotissue formation, should multifactorial approaches that consider both surface topography and substrate rigidity be established.

PKDL--A Silent Parasite Pool for Transmission of Leishmaniasis in Kala-azar Endemic Areas of Malda District, West Bengal, India

Post Kala-azar Dermal Leishmaniasis (PKDL) is a chronic but not life-threatening disease; patients generally do not demand treatment, deserve much more attention because PKDL is highly relevant in the context of Visceral Leishmaniasis (VL) elimination. There is no standard guideline for diagnosis and treatment for PKDL. A species-specific PCR on slit skin smear demonstrated a sensitivity of 93.8%, but it has not been applied for routine diagnostic purpose. The study was conducted to determine the actual disease burden in an endemic area of Malda district, West Bengal, comparison of the three diagnostic tools for PKDL case detection and pattern of lesion regression after treatment. The prevalence of PKDL was determined by active surveillance and confirmed by PCR based diagnosis. Patients were treated with either sodium stibogluconate (SSG) or oral miltefosine and followed up for two years to observe lesion regression period. Twenty six PKDL cases were detected with a prevalence rate of 27.5% among the antileishmanial antibody positive cases. Among three diagnostic methods used, PCR is highly sensitive (88.46%) for case confirmation. In majority of the cases skin lesions persisted after treatment completion which gradually disappeared during 6–12 months post treatment period. Reappearance of lesions noted in two cases after 1.5 years of miltefosine treatment. A significant number of PKDL patients would remain undiagnosed without active mass surveys. Such surveys are required in other endemic areas to attain the ultimate goal of eliminating Kala-azar. PCR-based method is helpful in confirming diagnosis of PKDL, referral laboratory at district or state level can achieve it. So a well-designed study with higher number of samples is essential to establish when/whether PKDL patients are free from parasite after treatment and to determine which PKDL patients need treatment for longer period.

A significant number of PKDL patients have been detected in the endemic areas of Malda who would remain undiagnosed without active mass surveys. Such active survey is required in other endemic areas of the country to attain the ultimate goal of eliminating Kala-azar from this part of the world by reducing the source of infection. PCR-based method is helpful in confirming diagnosis of PKDL, which is not applicable at field level. A referral laboratory at district or state level can be a solution to the problem. Since PKDL cases do not have a fatal outcome, treatment administration of these cases can be deferred until confirmed results are obtained, which requires about 7 days’ time. The detection of leishmanial DNA in skin lesions during successive treatment courses is essential to establish whether/ when PKDL patients are parasite free during/after treatment and to determine which PKDL patients need treatment for a longer period.

Osteosarcoma: an immunophenotypic study for characterization and behavior

Background: Osteosarcoma is the most common primary bone tumor occurring in second and third decades of life with a second peak later. Biopsy (needle or incision) is necessary for diagnosis along with imaging modalities (X-ray, CT scan etc) and serology. Due to diagnostic dilemma in certain cases and for prognosis of patients, immunohistochemistry is increasingly used. Aims: To assess the pathologic features and determinants of osteosarcoma in patients of the Indian subcontinent that would put an insight into its appearance and behavior. Methods and Material: Forty cases of biopsy proven osteosarcoma were selected over a period of three years. Histopathology was done for tumor typing, along with serology (pre and post-operative serum alkaline phosphatase). In all cases TNM staging and immunohistochemistry for antibodies to Osteonectin (ON) (diagnosis), S100 (differentiation), Ki 67 and Her2 (prognosis) was done. Results: Serum alkaline phosphatase was high in 37 (92%) cases initially and remained high in metastatic and recurrent lesions. Osteonectin was positive in 38 (95%) cases, S100 in 31 (77%), Ki 67 showed overlapping labeling indices between 4.8-18.8% and Her2 showed more positivity in higher stage tumors. Conclusions: Biopsy (along with imaging) is mandatory to diagnose osteosarcoma. Osteonectin is a good immunohistochemical marker to differentiate osteosarcoma from its mimics. For prognostication, serum alkaline phosphatase, post chemotherapy tumor necrosis (more than 90%), lack of Her2 expression are good parameters. S100 and Ki67 were found to have limited role in diagnosis and prognosis of osteosarcoma. DOI: http://dx.doi.org/10.3329/bjms.v13i4.13573 Bangladesh Journal of Medical Science Vol.13(4) 2014 p.443-448 

Immunocytochemistry: It's role in diagnosis of undifferentiated neoplasms by fine needle aspiration cytology

Background:

Fine needle aspiration cytology (FNAC) is a rapid, cheap and reliable method for diagnosing any accessible lesion. However, there remains a group of malignant undifferentiated neoplasms, which can only be categorized with the help of immunocytochemistry (ICC). The categorization is important due to their vast difference in treatment and prognosis.

Aim:

To evaluate the effectiveness of ICC in categorizing the undifferentiated neoplasms diagnosed on routine FNAC smears.

Materials and Methods:

Thirty six cases of undifferentiated neoplasms were selected from a group of total 78 cytology cases of undifferentiated tumors from different sites like head and neck, lymph node, soft tissue etc. These were then subjected to a panel of ICC markers based on the clinical and cytomorphological features.

Results:

Of these, 21 were simple, ten were computerized tomography guided and five were ultrasound guided FNACs respectively. All the 78 cases were confirmed by histopathological examination and immunohistochemistry. Of the 36 cytological cases, final diagnosis correlated in 30 cases histologically. The six cases were incorrect either due to inadequate material on the smears (three cases) or false positive staining (three cases).

Conclusions:

Our study found that ICC is a sensitive and specific method for early and definitive diagnosis of undifferentiated neoplasms. However, selection of antibodies must be judicious to make it cost effective.