Protein signaling and morphological development of the tail fluke in the embryonic beluga whale (Delphinapterus leucas)

BACKGROUND

During the land-to-sea transition of cetaceans (whales, dolphins, and porpoises), the hindlimbs were lost and replaced by an elaborate tail fluke that evolved 32 Ma. All modern cetaceans utilize flukes for lift-based propulsion, and nothing is known of this organ's molecular origins during embryonic development. This study utilizes immunohistochemistry to identify the spatiotemporal location of protein signals known to drive appendage outgrowth in other vertebrates (e.g., Sonic Hedgehog [SHH], GREMLIN [GREM], wingless-type family member 7a [WNT], and fibroblast growth factors [FGFs]) and to test the hypothesis that signals associated with outgrowth and patterning of the tail fluke are similar to a tetrapod limb. Specifically, this study utilizes an embryo of a beluga whale (Delphinapterus leucas) as a case study.

RESULTS

Results showed epidermal signals of WNT and FGFs, and mesenchymal/epidermal signals of SHH and GREM. These patterns are most consistent with vertebrate limb development. Overall, these data are most consistent with the hypothesis that outgrowth of tail flukes in cetaceans employs a signaling pattern that suggests genes essential for limb outgrowth and patterning shape this evolutionarily novel appendage.

CONCLUSIONS

While these data add insights into the molecular signals potentially driving the evolution and development of tail flukes in cetaceans, further exploration of the molecular drivers of fluke development is required.

Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Predicting clinical trial outcomes using drug bioactivities through graph database integration and machine learning

The ability to estimate the probability of a drug to receive approval in clinical trials provides natural advantages to optimizing pharmaceutical research workflows. Success rates of clinical trials have deep implications for costs, duration of development, and under pressure due to stringent regulatory approval processes. We propose a machine learning approach that can predict the outcome of the trial with reliable accuracies, using biological activities, physicochemical properties of the compounds, target-related features, and NLP-based compound representation. In the above list, biological activities have never been used as an independent variable towards the prediction of clinical trial outcomes. We have extracted the drug-disease pair from clinical trials and mapped target(s) to that pair using multiple data sources. Empirical results demonstrate that ensemble learning outperforms independently trained, small-data ML models. We report results and inferences derived from a Random forest classifier with an average accuracy of 93%, and an F1 score of 0.96 for the "Pass" class. "Pass" refers to one of the two classes (Pass/Fail) of all clinical trials, and the model performed well in predicting the "Pass" category. Through the analysis of feature contributions to predictive capability, we have demonstrated that bioactivity plays a statistically significant role in predicting clinical trial outcome. A significant effort has gone into the production of the dataset that, for the first time, integrates clinical trial information with protein targets. Cleaned, organized, integrated data and code to map these entities, created as a part of this work, are available open-source. This reproducibility and the freely available code ensure that researchers with access to deep curated and proprietary clinical trial databases (we only use open-source data in this study) can further expand the scope of the results.

India's National Action Plan on Antimicrobial Resistance: a critical perspective

Antimicrobial resistance (AMR) is widely recognised as a global health threat, which is projected to account for more deaths than cancer by 2050. The Government of India has formulated a National Action Plan to tackle AMR (NAP-AMR), largely modelled on the World Health Organization's Global Action Plan on AMR. While the NAP-AMR successfully mirrors the Global Action Plan and lays out ambitious goals, we find that the lack of financial allocation across states, poor enforcement and inadequate multisectoral co-ordination have hampered progress. A broader focus on improving infrastructure for water and sanitation, linking the issue of AMR to existing vertical health programmes for human immunodeficiency virus (HIV) and tuberculosis (TB), prioritising infection prevention and control, strengthening the frontline healthcare workforce in rural and peri-urban settings to reduce reliance on antibiotics, leveraging point-of-care testing and mobile app-based health interventions for diagnosis and surveillance, and adopting a socioecological approach to health and development would help to create an enabling environment for concrete action on AMR in India.

Perinatal mental health in India: protocol for a validation and cohort study

BACKGROUND

Common mental disorders (CMD) are among the largest contributors to global maternal morbidity and mortality. Although research on perinatal mental health in India has grown in recent years, important evidence gaps remain, especially regarding CMD. Our study aims to improve understanding of CMD among perinatal and non-perinatal women of reproductive age across two settings in India: Bangalore (Karnataka) and Tanda (Himachal Pradesh).

METHODS

The study is embedded within the Maternal and Perinatal Health Research Collaboration India (MaatHRI). This mixed-methods observational study comprises three consecutive phases: (i) focus group discussions and individual interviews to explore women's knowledge and seek feedback on CMD screening tools; (ii) validation of CMD screening tools; and (iii) prospective cohort study to identify CMD incidence, prevalence and risk factors among perinatal and non-perinatal women. Results of the three phases will be analyzed using inductive thematic analysis, psychometric analysis and multivariable regression analysis, respectively.

CONCLUSION

Improving understanding, detection and management of CMD among women is key to improving women's health and promoting gender equality. This study will provide evidence of CMD screening tools for perinatal and non-perinatal women in two diverse Indian settings, produce data on CMD prevalence, incidence and risk factors and enhance understanding of the specific contribution of the perinatal state to CMD.

708 Examining the Management of Acute Lower GI Bleeds in Order to Improve Policies and Reflect Safe and Updated Guidance

Introduction

Acute lower gastrointestinal bleeding (LGIB) tends to occur in elderly patients with complex comorbidities. At North Middlesex University Hospital (NMUH), LGIB patients are primarily managed by the surgical department. We amended local policies by integrating aspects of new guidelines published by the British Society of Gastroenterology (BSG).

Method

Handover documentation between November 2019 and January 2020 established patients admitted with LGIB (n = 45). Further data regarding the management of these patients was collated from clinical software and compared to standards set from BSG guidelines.

Results

We found NMUH to be efficient in ruling out upper GI bleeds via 24-hour OGDs and had low surgical intervention rates (0.02%). 40% of patients were transfused with an admission haemoglobin above suggested NICE thresholds, accounting for cardiovascular comorbidities. 56% of patients were discharged without a documented anticoagulation plan. Over 50% of patients did not have BSG recommended inpatient investigations.

Conclusions

Updated Trust guidelines aim to uphold areas that NMUH were shown to excel in, while reiterating NICE transfusion thresholds and include guidance regarding anticoagulant and antiplatelet medications. The Oakland score and shock index have been integrated into local protocols and will aid clinicians in making safe decisions in the management of LGIB patients.

Triple-negative breast cancers with expression of glucocorticoid receptor in immune cells show better prognosis

Background

Glucocorticoid receptor (GR) is shown to have variable frequency of expression in invasive tumors of the breast. Investigation of additional nuclear receptors like GR in receptor negative tumors like triple negative breast cancer (TNBC) may have prognostic and therapeutic significance.

Methods

Expression of GR was evaluated by immunohistochemistry in 175 tumors of invasive breast cancer with long term follow up. GR Expression was separately evaluated in invasive tumor cells, stromal cells and tumor infiltrating lymphocytes (TIL's). Staining pattern was categorised as positive when more than 1% of the cells stained in each subpopulation of cells. Disease free survival was analysed between GR positive and negative status by Kaplan Meier analysis.

Results

Of the 175 tumors, 121 (70%) were ER positive, 53 (30%) were ER negative and 29% (51) were triple negative. 74% (130/175) tumors showed expression of GR in invasive tumor cells while (84%) 147/175 had expression in TIL's. No significant difference in distribution of GR was noted between ER positive and ER negative tumors (78% vs 66%, p-0.1). Of the TNBC's 54% (28/51) and 70% (36/51) showed expression of GR in invasive tumor and TIL's respectively. Overall, GR positive tumors had significant better survival than GR negative tumors (mean survival time of 85 vs 59 months respectively, p-0.04) Contrary to the reports that GR expression in TIL's are associated with immunosuppressive activity in model systems, TNBC's with increased expression of GR in immune cells were associated with better survival (Mean survival time 74 vs 41 months, log rank test- p-0.03). TNBC tumors which were GR negative had higher lymph node metastases (p-0.04) and none of the other clinical features like age, menopausal state, tumor size and grade were different between GR positive and negative tumors within TNBC.

Conclusions

Glucocorticoids (GC) are often used to alleviate the adverse symptoms during chemotherapy. Determining the GR status is of importance due to the pro cell survival effect of the glucocorticoids mediated through GR during chemotherapy. Though GC mediated effects on chemotherapy are controversial, our results indicate favourable effects in TNBC.

18 Socio-Demographic Associations of COVID Antibody in Multi-Ethnic Healthcare Workers

Introduction

Healthcare workers are particularly susceptible to developing COVID-19 owing to close and frequent contact with COVID-19 patients. This study aimed to describe prevalence of SARS-COV-2 antibodies amongst healthcare workers within a hospital trust and examine factors associated with increased prevalence of this antibody.

Methods

Data was obtained over a 4-week period in 2020 from a cross-sectional prospective survey of healthcare workers serving a multi-ethnic inner-city population who had IgG SARS-COV-2 antibody. Multiple, overlapping sources of notification were implemented to promote the availability of the test. Anonymised socio-demographic data about staff members were cross referenced with data of the antibody tests.

Results

Of 7,013,6,212 (89%) staff undertook the antibody test during the study period. The overall detection rate of IgG SARS COV-2 antibody was 26%(1584/6212). Univariate analyses reveal that there were no differences in the prevalence rates in terms of gender or age. Compared to white staff members (18%), prevalence of the antibody was significantly greater in Black(38%) and Asian(27%) staff members. The combined prevalence for all BAME staff members was 32%. The prevalence rates of staff in general wards (43%) were significantly higher other areas of the trust. For staff in emergency medicine, intensive care and anaesthetics, prevalence was 23%, whereas for other clinical teams it was 21%. In terms of professional groups, prevalence rates were highest amongst nursing and allied clinical services (28%), followed by doctors (23%), whereas, it was lower for non-clinical staff(19%).

Discussion

This large multi-ethnic hospital-based study has described the prevalence of recent exposure to SARS-COV-2 infection amongst healthcare workers and determined socio-demographic associations of this prevalence including ethnicity, professional healthcare groups, and geographical areas of work in healthcare settings. The study provides information that may be useful in future COVID studies examining the role of antibody testing both in general populations as well as in healthcare settings.

Distribution, contamination status and bioavailability of trace metals in surface sediments along the southwest coast of India

This study investigates the influence of upwelling induced seasonal hypoxia in the sediment-water interface on the distribution, bioavailability and geochemical partitioning of selected trace metals in surficial sediments along the southwest coast of India based on two successive cruises. The first cruise was during the southwest monsoon (SWM) season when coastal waters exhibited intermittent bottom hypoxia due to upwelling. The second cruise during the northeast monsoon (NEM) season was characterised by a uniformly warm and well-oxygenated water column in the study region. The results showed that grain size, organic carbon and Fe are the major factors influencing the distribution of trace metals in the surface sediments. Based on the geochemical indices (contamination factor, enrichment factor and geo-accumulation factor), the study region appears to be moderately contaminated by Ni, Cr, and Pb. Based on the ecological risk assessment criteria, the enrichment of Pb, Cr and Ni may cause adverse effects on the benthic organisms. The fractionation studies demonstrated that the major pathway of metal deposition in the sediment is lithogenic. The data also showed that labile and organic fractions are the second dominant forms, while other fractions (exchangeable and carbonate) are insignificant. The consistency in the reactive Fe concentrations during SWM and NEM could be due to the absence of Fe dissolution in sediments under mild reducing condition (intermittent hypoxia). In addition to the above, an enrichment of organic matter also leads to increased deposition of trace metals in sediments. Conversely, the secondary phase enrichment factor and risk assessment code calculated based on the metal fractionation data indicated low risk and contamination along the southwest coast of India except for Zn that showed moderate contamination in some transects. The study provides the need for regular geochemical assessment to control metal pollution in the coastal environment, which is a major resource of the fishery.

Prevalence and socio-demographic factors of SARS-CoV-2 antibody in multi-ethnic healthcare workers

INTRODUCTION

Healthcare workers are particularly susceptible to developing COVID-19 owing to close and frequent contact with COVID-19 patients. This cross-sectional study aimed to describe prevalence of SARS-CoV-2 antibodies among healthcare workers within a hospital trust and examine factors associated with increased prevalence of this antibody.

METHODS

Data was obtained over a 4-week period in 2020 from a cross-sectional prospective survey of healthcare workers serving a multi-ethnic inner-city population who had immunoglobulin G SARS-CoV-2 antibody test. Anonymised socio-demographic data about staff were cross-referenced with these tests.

RESULTS

Of 7,013 staff, 6,212 (89%) undertook the antibody test during this period. Overall detection rate was 26% (1,584/6,212). Univariate analyses revealed no differences in prevalence in terms of gender or age. Compared with white staff members (18%), rates were higher in black (38%) and Asian (27%) members (p<0.001). The rates in general wards (43%) were higher compared with other areas; in emergency medicine and intensive care, prevalence was 23% (p<0.001). Regarding professional groups, prevalence was highest among nursing and allied clinical services (28%), less in doctors (23%) and lower in non-clinical staff (19%).

DISCUSSION

This large study has described prevalence of recent exposure to SARS-CoV-2 infection among healthcare workers and determined associations including ethnicity, professional groups and geographical areas within healthcare settings. This information will be useful in future COVID-19 studies examining the role of antibody testing both in general populations and in healthcare settings.

Magnetic Nanoparticle and Exosomal Therapeutic (M-NEXT) Effects on HIV-Associated Neurotoxicity

The human immunodeficiency virus (HIV) envelope glycoprotein protein 120 (gp120) induces neurotoxicity associated with HIV-associated neurocognitive disorders (HAND). Mechanism of Gp120-mediated neurotoxicity is primarily apoptosis. Currently, there are no therapeutics that address gp120 neurotoxicity. A biocompatible, efficacious therapeutic that easily crosses the blood-brain barrier (BBB) is needed to treat neuronal toxicity observed in HIV-infected individuals. Magnetic nanoparticles (MNPs) have successfully delivered anti-HIV agents across in vitro BBB transwell model. However, MNPs at high doses may damage cells. Exosomal extracellular vesicles (xEVs) are endogenous nanocarriers capable of crossing the BBB. Unlike MNPs, xEVs interact with cells in a paracrine or juxtracrine manner, lacking long-range site specificity. Here we investigated the efficacy of an MNP and xEV-coupled therapeutic (M-NEXT) as a nanocarrier for targeted delivery of anti-HIV fusion agent across the BBB to inhibit HIV-gp120 associated neuropathology. M-NEXT consisting of MNPs encapsulated within xEV carrying T20 peptide on the surface was synthesized and characterized via zeta potential, dynamic light scattering, and TEM imaging. Preliminary efficacy studies using SH-SY5Y cocultured with the in vitro BBB model showed that the M-NEXT-T20-fusion peptide protected neurons from HIV gp120-mediated neurotoxicity. Additionally, BBB integrity and permeability assessed via trans-endothelial resistance (TEER) and a Dextran-FITC transport assay was unaffected. SH-SY5Y viability measured by XTT assay was not significantly modulated by M-NEXT. In summary, preliminary findings support M-NEXT as effective nanocarriers for delivery of anti-HIV gp120 associated neurotoxicity agents.

A novel approach using hand-held echocardiography to guide the diagnosis of heart failure in pregnant women in a low-resource setting; Maternal and Perinatal Health Research Collaboration

Background

Point of care imaging devices are promising tools for cardiovascular imaging in low-resource settings.

Purpose

Our aim was to determine whether hand-held echocardiography scans performed by obstetricians can help to identify the cardiac phenotypes in pregnant women with heart failure in India.

Methods

In November 2018, eighteen obstetricians from 10 hospitals across the states of Assam, Meghalaya and Uttar Pradesh were given 2 days of hands-on training in image acquisition using Philips Lumify devices. Obstetricians were asked to follow a simplified protocol of image acquisition and optimisation designed by the Oxford Cardiovascular Clinical Research Facility team. The protocol includes 3 key echocardiography views; parasternal long axis, parasternal short axis, and apical four chamber. Remote supervision and constructive feedback on performance was provided to improve image quality. Echocardiographic images of 269 pregnant women (with and without suspected heart failure) were acquired by the trained obstetricians, between February 2018 and January 2020. The first 147 scans were transferred with end-to-end encryption to the University of Oxford Research Echocardiography Core Laboratory (ORECL). Image interpretation and formal quality assessment was performed by 2 experienced echocardiographers.

Results

Parasternal long axis image quality was assessed as good in 78.3%, and was superior to both the parasternal short axis view (76.5%) and the apical 4-chamber view (61.9%). Image depth and gain optimisation was the main reason for loss of quality. The acquisition quality was related to reported clinical disease severity, and advanced pregnancy status. Left ventricular systolic function was impaired in 32 participants (21.9%), and 23.3% of the cohort had a dilated left atrium. Rheumatic heart disease was found in 12 participants (8.3%), in which the mitral valve was stenotic; 10 severe and 1 moderate. Mitral regurgitation was reported in 29 cases (20.8%); 6 severe, 7 moderate and 16 mild. Tricuspid and aortic valve abnormalities were also detected. Pericardial effusion was reported in 45 participants (30.8%).

Conclusion

Obstetricians with supervised training, using hand-held echocardiography have demonstrated acceptable image acquisition quality which could be assessed through core laboratory analysis to detect cardiac abnormalities. Such an approach could be useful to guide the diagnosis of heart failure in pregnant women in low-resource settings. Further training for the obstetricians and image quality assurance have been implemented in the ongoing MaatHRI study with plans to conduct a validation analysis.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Medical Research Council (MRC), UK Fellowship for M Nair.

Characterization of the renal cortical transcriptome following Roux-en-Y gastric bypass surgery in experimental diabetic kidney disease

INTRODUCTION

Roux-en-Y gastric bypass surgery (RYGB) reduces albuminuria and the long-term incidence of end-stage renal disease in patients with obesity and diabetes. Preclinical modeling in experimental diabetic kidney disease demonstrates that improvements in glomerular structure likely underpin these findings.

RESEARCH DESIGN AND METHODS

In adult male Zucker diabetic fatty (ZDF) rats, we profiled the effect of RYGB on weight and metabolic control as well biochemical, structural and ultrastructural indices of diabetic renal injury. Furthermore, we sequenced the renal cortical transcriptome in these rats and used bioinformatic pathway analyses to characterize the transcriptional alterations governing the renal reparative response to RYGB.

RESULTS

In parallel with improvements in weight and metabolic control, RYGB reduced albuminuria, glomerulomegaly, podocyte stress and podocyte foot process effacement. Pathway analysis of RYGB-induced transcriptomic changes in the renal cortex highlighted correction of disease-associated alterations in fibrosis, inflammation and biological oxidation pathways. RYGB reversed disease-associated changes in the expression of transforming growth factor (TGF)-β superfamily genes that strongly correlated with improvements in structural measures of glomerulopathy.

CONCLUSIONS

Improved glomerular structure in ZDF rats following RYGB is underpinned by pathway level changes, including interruption of the TGF-β-driven early profibrotic programme. Our data provide an important layer of experimental support for clinical evidence demonstrating that RYGB arrests renal damage in patients with obesity and type 2 diabetes.

Bioengineered Exosomal Extracellular Vesicles in Cancer Therapeutics

Liquid or blood-based biopsy is a less invasive and more efficient method in which to clinicians can identify diagnostic, prognostic, and therapeutic responsive biomarkers in cancer patients. Circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), RNAs, proteins, metabolites, and extracellular vesicles (EVs) are all potential biomarkers found in liquid biopsies. All nucleated cells including healthy, virally infected, and cancer cells release EVs. Since the early 1980s, evidence has mounted to support the pathophysiological role of EVs in cancer. Here we focus on the smallest of the EV, the exosome, and their clinical relevance as nanotherapeutics for cancers. Exosomes obtained from tumors have been reported to promote and/or facilitate malignancy of cancers especially in terms of metastatic potential. Exosomal EVs have also contributed to the development of therapeutic resistance. Recent studies demonstrate that intrinsic and bioengineered exosomes can serve as effective therapeutic agents that disrupt cancer progression. Here we review the current literature regarding the utilization of bioengineered exosomes for therapeutics to treat prevalent cancers such as melanoma, glioma, breast, pancreatic, hepatic, cervical, prostate, and colon cancers. Overall, studies reviewed show that bioengineered exosomes are effective and promising for targeted cancer therapy.

TGF-β1 increases viral burden and promotes HIV-1 latency in primary differentiated human bronchial epithelial cells

Combination antiretroviral therapy (cART) has increased the life expectancy of HIV patients. However, the incidence of non-AIDS associated lung comorbidities, such as COPD and asthma, and that of opportunistic lung infections have become more common among this population. HIV proteins secreted by the anatomical HIV reservoirs can have both autocrine and paracrine effects contributing to the HIV-associated comorbidities. HIV has been recovered from cell-free bronchoalveolar lavage fluid, alveolar macrophages, and intrapulmonary lymphocytes. We have recently shown that ex-vivo cultured primary bronchial epithelial cells and the bronchial brushings from human subjects express canonical HIV receptors CD4, CCR5 and CXCR4 and can be infected with HIV. Together these studies suggest that the lung tissue can serve as an important reservoir for HIV. In this report, we show that TGF-β1 promotes HIV latency by upregulating a transcriptional repressor BLIMP-1. Furthermore, we identify miR-9-5p as an important intermediate in TGF-β-mediated BLIMP-1 upregulation and consequent HIV latency. The transcriptionally suppressed HIV can be reactivated by common latency reactivating agents. Together our data suggest that in patients with chronic airway diseases, TGF-β can elevate the HIV viral reservoir load that could further exacerbate the HIV associated lung comorbidities.

Cigarette smoke promotes HIV infection of primary bronchial epithelium and additively suppresses CFTR function

Recurrent lung infections are a common cause of morbidity and mortality in people living with HIV and this is exacerbated in smokers even when administered combination antiretroviral therapy (cART). The incidence of pneumonia is increased with smoking and treatment interruption and is directly dependent on viral load in patients when adjusted for CD4 counts. CFTR dysfunction plays an important role in aberrant airway innate immunity as it is pivotal in regulating mucociliary clearance (MCC) rates and other antibacterial mechanisms of the airway. In our earlier work, we have demonstrated that bronchial epithelium expresses canonical HIV receptors CD4, CCR5 and CXCR4 and can be infected with HIV. HIV Tat suppresses CFTR mRNA and function via TGF-β signaling. In the present study, we demonstrate that cigarette smoke (CS) potentiates HIV infection of bronchial epithelial cells by upregulating CD4 and CCR5 expression. HIV and CS individually and additively suppress CFTR biogenesis and function, possibly explaining the increased incidence of lung infections in HIV patients and its exacerbation in HIV smokers.

E-cigarettes: a need to broaden the debate

The unregulated market for e-cigarettes continues to grow, with debates on their efficacy and impact on global public health. E-cigarettes, or electronic nicotine delivery systems (ENDs), are marketed as a 'safe' alternative to tobacco products and a tool for 'harm reduction'. Some public health experts are calling it a 'game changer' and favour the 'harm reduction' strategy, while others dispute this claim. In our opinion, the debate needs to be broadened to encompass other related concerns and effects on non-users and affected stakeholders. As with tobacco control, a holistic approach is needed to build a raft of policies that effectively address the issue from all angles and look beyond the direct health implications of e-cigarette use to explore the social, economic, political and environmental aspects of this debate, putting 'harm reduction' in context.

Induced Pluripotent Stem Cell Technology: A Paradigm Shift in Medical Science for Drug Screening and Disease Modeling

BACKGROUND

Induced Pluripotent Stem Cell (IPSC) Technology is the most advanced research as it offers an attractive alternative for establishing patient-specific IPSCs to recapitulate phenotypes of not only monogenic diseases (viz. Thalassaemia, Sickle cell anemia, Haemophilia, Tay-Sachs disease), but also late-onset polygenic diseases (viz. Parkinson's disease, Alzheimer's disease, schizophrenia). Over the hindsight, numerous studies of the past and current scientists have led to the production, maturation and understanding of induced pluripotent stem cell technology and its use in basic and clinical research.

METHODS

A systematic search of peer-reviewed scientific literature and clinical trials in public databases were carried out to summarize the evidence on the use of IPSC.

RESULTS

Current review sheds light upon the use of patient-derived iPSC models in drug toxicity, screening and discovery which have been derived after referring to more than 200 articles in literature. Furthermore, their use as disease models was also studied signifying the versatility of iPSC lines.

CONCLUSION

Through this review, we describe the advent of iPSC technology, where we comprehensively cover the generation of iPSCs and their characterization along with their prospective applications using IPSC banks in disease modeling and drug screening.

Common gene-network signature of different neurological disorders and their potential implications to neuroAIDS

The neurological complications of AIDS (neuroAIDS) during the infection of human immunodeficiency virus (HIV) are symptomized by non-specific, multifaceted neurological conditions and therefore, defining a specific diagnosis/treatment mechanism(s) for this neuro-complexity at the molecular level remains elusive. Using an in silico based integrated gene network analysis we discovered that HIV infection shares convergent gene networks with each of twelve neurological disorders selected in this study. Importantly, a common gene network was identified among HIV infection, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and age macular degeneration. An mRNA microarray analysis in HIV-infected monocytes showed significant changes in the expression of several genes of this in silico derived common pathway which suggests the possible physiological relevance of this gene-circuit in driving neuroAIDS condition. Further, this unique gene network was compared with another in silico derived novel, convergent gene network which is shared by seven major neurological disorders (Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Age Macular Degeneration, Amyotrophic Lateral Sclerosis, Vascular Dementia, and Restless Leg Syndrome). These networks differed in their gene circuits; however, in large, they involved innate immunity signaling pathways, which suggests commonalities in the immunological basis of different neuropathogenesis. The common gene circuits reported here can provide a prospective platform to understand how gene-circuits belonging to other neuro-disorders may be convoluted during real-time neuroAIDS condition and it may elucidate the underlying-and so far unknown-genetic overlap between HIV infection and neuroAIDS risk. Also, it may lead to a new paradigm in understanding disease progression, identifying biomarkers, and developing therapies.

Hirschsprung's disease in the UK and Ireland: incidence and anomalies

OBJECTIVES

To describe clinical characteristics and preoperative management of a national cohort of infants with Hirschsprung's disease (HD).

DESIGN

Population-based cohort study of all live-born infants with HD born in the UK and Ireland from October 2010 to September 2012.

SETTING

All 28 paediatric surgical centres in the UK and Ireland.

PARTICIPANTS

305 infants presenting before 6 months of age with histologically proven HD.

MAIN OUTCOME MEASURES

Incidence, clinical characteristics including gestational age, birth weight, gender, associated anomalies; age and clinical features at presentation; and use of rectal washouts or stoma.

RESULTS

The incidence of HD in the UK and Ireland was 1.8 per 10 000 live births (95% CI 1.5 to 1.9). Male to female ratio was 3.3:1. An associated anomaly was identified in 23% (69), with 15% (47) having a recognisable syndrome. The proportion of infants who presented and were diagnosed in the neonatal period was 91.5% (279) and 83.9% (256), respectively. 23.9% (73) and 44.2% (135) passed meconium within 24 and 48 hours of birth. 81% (246) first presented to a hospital without tertiary paediatric surgical services, necessitating interhospital transfer. Initial colonic decompression was by rectal washouts in 86.2% (263) and by defunctioning stoma in 12.8% (39). Subsequently, 27.4% (72) of infants failed management with rectal washouts and required a delayed stoma, resulting in 36.4% (111) of infants having a stoma.

CONCLUSIONS

In this population-based cohort, presentation outside the neonatal period was rare. Nearly half of the infants with HD passed meconium within 48 hours of birth and over one third were managed with a stoma.

Positioning of the SCRAMBLED receptor requires UDP-Glc:sterol glucosyltransferase 80B1 in Arabidopsis roots

The biological function of sterol glucosides (SGs), the most abundant sterol derivatives in higher plants, remains uncertain. In an effort to improve our understanding of these membrane lipids we examined phenotypes exhibited by the roots of Arabidopsis (Arabidopsis thaliana) lines carrying insertions in the UDP-Glc:sterol glucosyltransferase genes, UGT80A2 and UGT80B1. We show that although ugt80A2 mutants exhibit significantly lower levels of total SGs they are morphologically indistinguishable from wild-type plants. In contrast, the roots of ugt80B1 mutants are only deficient in stigmasteryl glucosides but exhibit a significant reduction in root hairs. Sub-cellular investigations reveal that the plasma membrane cell fate regulator, SCRAMBLED (SCM), is mislocalized in ugt80B1 mutants, underscoring the aberrant root epidermal cell patterning. Live imaging of roots indicates that SCM:GFP is localized to the cytoplasm in a non cell type dependent manner instead of the hair (H) cell plasma membrane in these mutants. In addition, we provide evidence for the localization of the UGT80B1 enzyme in the plasma membrane. These data lend further support to the notion that deficiencies in specific SGs are sufficient to disrupt normal cell function and point to a possible role for SGs in cargo transport and/or protein targeting to the plasma membrane.

Factors associated with maternal mortality at advanced maternal age: a population-based case-control study

OBJECTIVE

This study aimed to examine the factors associated with maternal mortality among women aged ≥35 years.

DESIGN

Unmatched population based case-control study.

SETTING

United Kingdom.

POPULATION

Between 2009 and 2012, 105 cases of maternal deaths aged ≥35 years were extracted from the surveillance database of the MBRRACE-UK confidential enquiries into maternal deaths in the UK. In addition, 766 controls aged ≥35 years were identified from the UK Obstetric Surveillance System (2005-2012).

METHODS

Risk factors known to be associated with maternal mortality and morbidity and for which data were available were examined for their association with maternal mortality among women ≥35 years using logistic regression analysis.

MAIN OUTCOME MEASURES

Odds ratios and 95% confidence intervals associated with maternal death.

RESULTS

Five factors were found to be significantly associated with increased odds of death among women aged ≥35 years: smoking during pregnancy (adjusted odds ratio (aOR) 2.06, 95% CI 1.13-3.75), inadequate use of antenatal care (aOR 23.62, 95% CI 8.79-63.45), medical co-morbidities (aOR 5.92, 95% CI 3.56-9.86) and previous pregnancy problems (aOR 2.06, 95% CI 1.23-3.45). The odds associated with death increased by 12% per year increase in age (aOR 1.12, 95% CI 1.02-1.22).

CONCLUSION

Age was associated with maternal mortality even after adjusting for other known risk factors. Importantly, this study showed an association between maternal mortality and smoking among women aged 35 years or older. It emphasises the importance of public health action to reduce smoking levels and address trends in rising maternal age.

TWEETABLE ABSTRACT

Smoking is a risk factor for maternal death for those aged over 35 years.

Ovarian tumors in children: 10-year experience from a tertiary care center in South India

BACKGROUND

Ovarian tumors are uncommon in childhood and constitute around 1% of childhood malignancies. Two thirds of pediatric ovarian tumors are germ cell tumors. Epithelial ovarian tumors and stromal tumors are less frequent. We share our experience in childhood ovarian cancers, analyzing a series of cases with respect to the clinical profile, treatment and survival.

METHODS

All newly diagnosed ovarian tumors in children up to 14 years of age, registered in our Pediatric Oncology Division between January 2000 and December 2009 were retrospectively reviewed.

OBSERVATIONS

There were 47 patients with newly diagnosed ovarian tumors. The mean age at presentation was 10.0 ± 3.4 years. The most common symptoms at presentation were acute abdominal pain (48.9%) and abdominal mass (40.4%). Precocious puberty was uncommon (6.3%). Histology was germ cell tumors in 44 cases and nongerm cell tumors in three cases. The benign teratomas (mature and immature grade 1 and 2; n=9) underwent complete surgical resection alone; none had recurrence on follow up. Of the remaining 35 GCTs, 31 patients were given chemotherapy and 4 refused treatment.26 out of the 31 patients completed chemotherapy with BEP (bleomycin, etoposide, cisplatin) regimen with acceptable toxicities. 5 children i.e.; (19.2%) developed recurrence. At a median follow up of 80 months, 10 year disease free survival was 80.8 ± 7.7% and 10 year overall survival was 92.7 ± 4.9%.

CONCLUSION

Germ cell tumors are the most common ovarian malignancy in children. With surgery and chemotherapy using BEP, good outcome can be expected in these patients.

HIV Infects Bronchial Epithelium and Suppresses Components of the Mucociliary Clearance Apparatus

Recurrent lung infections and pneumonia are emerging as significant comorbidities in the HIV-infected population in the era of combination antiretroviral therapy (cART). HIV infection has been reported to suppress nasal mucociliary clearance (MCC). Since the primary components driving nasal MCC and bronchial MCC are identical, it is possible that bronchial MCC is affected as well. Effective MCC requires optimal ciliary beating which depends on the maintenance of the airway surface liquid (ASL), a function of cystic fibrosis transmembrane conductance regulator (CFTR) activity and the integrity of the signaling mechanism that regulates ciliary beating and fluid secretion. Impairment of either component of the MCC apparatus can compromise its efficacy and promote microbial colonization. We demonstrate that primary bronchial epithelium expresses HIV receptor CD4 and co-receptors CCR5 and CXCR4 and can be infected by both R5 and X4 tropic strains of HIV. We show that HIV Tat suppresses CFTR biogenesis and function in primary bronchial epithelial cells by a pathway involving TGF-β signaling. HIV infection also interferes with bronchial epithelial cell differentiation and suppresses ciliogenesis. These findings suggest that HIV infection suppresses tracheobronchial mucociliary clearance and this may predispose HIV-infected patients to recurrent lung infections, pneumonia and chronic bronchitis.

Mechanisms underpinning remission of albuminuria following bariatric surgery

PURPOSE OF REVIEW

Albuminuria is a biomarker of renal injury commonly used to monitor progression of diabetic kidney disease. The appearance of excess albumin in the urine reflects alterations in the structure and permeability of the glomerular filtration barrier. The present article summarizes the clinical evidence base for remission of albuminuria after bariatric surgery. It furthermore focuses on how beneficial impacts on glomerular podocyte structure and function may explain this phenomenon.

RECENT FINDINGS

A coherent clinical evidence base is emerging demonstrating remission of albuminuria following bariatric surgery in patients with obesity and diabetes. The impaired metabolic milieu in diabetic kidney disease drives podocyte dedifferentiation and death through glucotoxic, lipotoxic proinflammatory, and pressure-related stress. Improvements in these parameters after surgery correlate with improvements in albuminuria and preclinical studies provide mechanistic data that support the existence of cause-effect relationship.

SUMMARY

The benefits of bariatric surgery extend beyond weight loss in diabetes to encompass beneficial effects on diabetic renal injury. Attenuation of the toxic metabolic milieu that the podocyte is exposed to postbariatric surgery suggests that the restitution of podocyte health is a key cellular event underpinning remission of albuminuria.

Coupling of transient near infrared photonic with magnetic nanoparticle for potential dissipation-free biomedical application in brain

Combined treatment strategies based on magnetic nanoparticles (MNPs) with near infrared ray (NIR) biophotonic possess tremendous potential for non-invasive therapeutic approach. Nonetheless, investigations in this direction have been limited to peripheral body region and little is known about the potential biomedical application of this approach for brain. Here we report that transient NIR exposure is dissipation-free and has no adverse effect on the viability and plasticity of major brain cells in the presence or absence superparamagnetic nanoparticles. The 808 nm NIR laser module with thermocouple was employed for functional studies upon NIR exposure to brain cells. Magnetic nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic laser scattering (DLS), and vibrating sample magnetometer (VSM). Brain cells viability and plasticity were analyzed using electric cell-substrate impedance sensing system, cytotoxicity evaluation, and confocal microscopy. When efficacious non-invasive photobiomodulation and neuro-therapeutical targeting and monitoring to brain remain a formidable task, the discovery of this dissipation-free, transient NIR photonic approach for brain cells possesses remarkable potential to add new dimension.

Clinical presentation, management, and outcomes in the Indian Heart Rhythm Society-Atrial Fibrillation (IHRS-AF) registry

Aim

A national atrial fibrillation (AF) registry was conducted under the aegis of the Indian Heart Rhythm Society (IHRS), to capture epidemiological data-type of AF, clinical presentation and comorbidities, current treatment practices, and 1-year follow-up outcomes.

Methods

A total of 1537 patients were enrolled from 24 sites in India in the IHRS-AF registry from July 2011 to August 2012. Their baseline characteristics and follow-up data were recorded in case report forms and subsequently analyzed.

Results

The average age of Indian AF patients was 54.7 years. There was a marginal female preponderance – 51.5% females and 48.5% males. At baseline, 20.4% had paroxysmal AF; 33% had persistent AF; 35.1% had permanent AF and 11% had first AF episode. At one-year follow-up, 45.6% patients had permanent AF.

Rheumatic valvular heart disease (RHD) was present in 47.6% of patients. Hypertension, heart failure, coronary artery disease, and diabetes were seen in 31.4%, 18.7%, 16.2%, and 16.1%, respectively.

Rate control was the strategy used in 75.2% patients, digoxin and beta-blockers being the most frequently prescribed rate-control drugs. Oral anticoagulation (OAC) drugs were used in 70% of patients. The annual mortality was 6.5%, hospitalization 8%, and incidence of stroke 1%.

Conclusions

In India, AF patients are younger and RHD is still the most frequent etiology. Almost two-third of the patients have persistent/permanent AF. At one-year follow-up, there is a significant mortality and morbidity in AF patients in India.

Identification and characterization of 20 novel pathogenic variants in 60 unrelated Indian patients with mucopolysaccharidoses type I and type II

Mucopolysaccharidoses (MPS), a subgroup of lysosomal storage disorders, are caused due to deficiency of specific lysosomal enzyme involved in catabolism of glycosaminoglycans. To date more than 200 pathogenic variants in the alpha-l-iduronidase (IDUA) for MPS I and ∼500 pathogenic variants in the iduronate-2-sulphatase (IDS) for MPS II have been reported worldwide. The mutation spectrum of MPS type I and MPS type II disorders in Indian population is not characterized yet. In this study, we carried out clinical, biochemical, molecular and in silico analyses to establish the mutation spectrum of MPS I and MPS II in the Indian population. We conducted molecular analysis for 60 MPS-affected patients [MPS I (n = 30) (Hurler syndrome = 17, Hurler-Scheie syndrome = 13), and MPS II (n = 30) (severe = 18, attenuated = 12)] and identified a total of 44 [MPS I (n = 22) and MPS II (n = 22)] different pathogenic variants comprising missense, nonsense, frameshift, gross deletions and splice site variants. A total of 20 [MPS I (n = 14), and MPS II (n = 6)] novel pathogenic sequence variants were identified in our patient cohort. We found that 32% of pathogenic variants detected in IDUA were recurrent and 25% in MPS II. This is the first study revealing the mutation spectrum of MPS I and MPS II patients in the Indian population.

Risk factors and newborn outcomes associated with maternal deaths in the UK from 2009 to 2013: a national case-control study

Objectives

To identify the risk factors for and adverse newborn outcomes associated with maternal deaths from direct and indirect causes in the UK.

Design

Unmatched case–control analysis.

Setting

All hospitals caring for pregnant women in the UK.

Population

Comprised 383 women who died (cases) from direct or indirect causes from 2009 to 2013 (Confidential Enquiry into Maternal Deaths in the UK) and 1516 women who did not have any life‐threatening complications during pregnancy and childbirth (controls) obtained from UK Obstetric Surveillance System (UKOSS).

Methods

Multivariable regression analyses were undertaken to examine potential risk factors, their incremental effects, and adverse newborn outcomes associated with maternal deaths.

Outcomes

Odds ratios associated for risk factors for maternal death and newborn outcomes (stillbirth, admission to neonatal intensive care unit [NICU], early neonatal death) and incremental risk.

Results

Seven factors, of 13 examined, were independently associated with increased odds of maternal death: pre‐existing medical comorbidities (adjusted odds ratio [aOR] 8.65; 95% CI 6.29–11.90), anaemia during pregnancy (aOR 3.58; 95% CI 1.14–11.21), previous pregnancy problems (aOR 1.85; 95% CI 1.33–2.57), inadequate use of antenatal care (aOR 46.85; 95% CI 19.61–111.94), substance misuse (aOR 12.21; 95% CI 2.33–63.98), unemployment (aOR 1.81; 95% CI 1.08–3.04) and maternal age (aOR 1.06; 95% CI 1.04–1.09). There was a four‐fold increase in the odds of death per unit increase in the number of risk factors. Odds of stillbirth, admission to NICU and early neonatal death were higher among women who died.

Conclusion

This study reiterates the need for optimal care for women with medical comorbidities and older age, and the importance of adequate antenatal care. It demonstrates the existence of socio‐economic inequalities in maternal death in the UK.

Tweetable abstract

Medical comorbidities and socio‐economic inequalities are important risk factors for maternal death in the UK.

Medical comorbidities and socio‐economic inequalities are important risk factors for maternal death in the UK.

Feather hydrolysate from Streptomyces sampsonii GS 1322: A potential low cost soil amendment

Process parameters for obtaining hydrolysate from hen feathers, i.e., initial pH (5.0-9.0) and incubation period (1-6 day), were set and studied, using Streptomyces sampsonii GS 1322 in submerged and solid state conditions. Under submerged conditions, complete hydrolysis of feathers was observed on fifth day [initial pH 8.0, 28 ± 2°C, shaking (150 rpm)] with release of soluble protein (2985 μg ml(-1)) and amino acids (2407 μg ml(-1)). Cell free hydrolysate showed hydrolysis of casein (18 mm), gelatin (26 mm), collagen (31 mm), hemoglobin (23 mm) and Tween 80 (35 mm) while 445 U keratinase activity. Total soluble protein reached 5 mg ml(-1) in solid state conditions. During Pot experimentation using barren agriculture soil the effect of feather hydrolysate on wheat crop were recorded. Significant increase (p<0.01) in wheat seed germination was observed in treated soils as compared to untreated. Treatment significantly increased plant height from 30 to 60 days and 30-90 days (p<0.001). Treated soil showed an increase in total microbial count, proteolytic activity, phosphate solubilizing bacteria and ammonifying bacteria, whereas pathogenic fungi load was reduced. S. sampsonii GS 1322 can be used for bio-processing of poultry wastes yielding feather hydrolysate rich in proteins and amino acids for development of low-cost organic amendment to accelerate wheat crop growth in barren agricultural land.

Goblet Cell Derived RELM-β Recruits CD4+ T Cells during Infectious Colitis to Promote Protective Intestinal Epithelial Cell Proliferation

Enterohemorrhagic Escherichia coli and related food and waterborne pathogens pose significant threats to human health. These attaching/effacing microbes infect the apical surface of intestinal epithelial cells (IEC), causing severe diarrheal disease. Colonizing the intestinal luminal surface helps segregate these microbes from most host inflammatory responses. Based on studies using Citrobacter rodentium, a related mouse pathogen, we speculate that hosts rely on immune-mediated changes in IEC, including goblet cells to defend against these pathogens. These changes include a CD4⁺ T cell-dependent increase in IEC proliferation to replace infected IEC, as well as altered production of the goblet cell-derived mucin Muc2. Another goblet cell mediator, REsistin-Like Molecule (RELM)-β is strongly induced within goblet cells during C. rodentium infection, and was detected in the stool as well as serum. Despite its dramatic induction, RELM-β’s role in host defense is unclear. Thus, wildtype and RELM-β gene deficient mice (Retnlb^-/-) were orally infected with C. rodentium. While their C. rodentium burdens were only modestly elevated, infected Retnlb^-/- mice suffered increased mortality and mucosal ulceration due to deep pathogen penetration of colonic crypts. Immunostaining for Ki67 and BrDU revealed Retnlb^-/- mice were significantly impaired in infection-induced IEC hyper-proliferation. Interestingly, exposure to RELM-β did not directly increase IEC proliferation, rather RELM-β acted as a CD4⁺ T cell chemoattractant. Correspondingly, Retnlb^-/- mice showed impaired CD4⁺ T cell recruitment to their infected colons, along with reduced production of interleukin (IL)-22, a multifunctional cytokine that directly increased IEC proliferation. Enema delivery of RELM-β to Retnlb^-/- mice restored CD4⁺ T cell recruitment, concurrently increasing IL-22 levels and IEC proliferation, while reducing mucosal pathology. These findings demonstrate that RELM-β and goblet cells play an unexpected, yet critical role in recruiting CD4⁺ T cells to the colon to protect against an enteric pathogen, in part via the induction of increased IEC proliferation.

Food and water-borne bacterial pathogens such as enterohemorrhagic Escherichia coli (EHEC) target the epithelial cells that line the inner surface of their host’s intestines, causing inflammation and diarrhea. While professional immune cells including T lymphocytes are well known for promoting host defense, we hypothesized that as the cells in closest contact with these bacterial pathogens, intestinal epithelial cells also play an active and essential role in protecting the host during infection. Infecting mice with Citrobacter rodentium, a mouse specific relative of EHEC, we noted a dramatic upregulation in the expression and secretion of the mediator RELM-β by a subset of epithelial cells called goblet cells. Compared to wildtype mice, mice lacking RELM-β showed less epithelial cell proliferation and suffered significantly more intestinal damage during infection. Rather than directly causing epithelial cell proliferation, we found RELM-β instead recruited T lymphocytes to the infected intestine. Upon reaching the intestine, the T lymphocytes produced the cytokine interleukin-22, which directly increased epithelial cell proliferation. Taken together, these findings indicate that epithelial/goblet cells play a critical role in orchestrating the host response to an intestinal pathogen, by recruiting T lymphocytes and by promoting epithelial proliferation to limit the intestinal damage suffered during infection.

Progression from severe sepsis in pregnancy to death: a UK population-based case-control analysis

Objective

To identify factors associated with progression from pregnancy‐associated severe sepsis to death in the UK.

Design

A population‐based case‐control analysis using data from the UK Obstetric Surveillance System (UKOSS) and the UK Confidential Enquiry into Maternal Death (CEMD).

Setting

All pregnancy care and death settings in UK hospitals.

Population

All non‐influenza sepsis‐related maternal deaths (January 2009 to December 2012) were included as cases (n = 43), and all women who survived severe non‐influenza sepsis in pregnancy (June 2011 to May 2012) were included as controls (n = 358).

Methods

Cases and controls were identified using the CEMD and UKOSS. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals.

Main outcome measures

Odds ratios for socio‐demographic, medical, obstetric and management factors in women who died from sepsis, compared with those who survived.

Results

Four factors were included in the final regression model. Women who died were more likely to have never received antibiotics [aOR = 22.7, 95% confidence interval (CI) 3.64–141.6], to have medical comorbidities (aOR = 2.53, 95%CI 1.23–5.23) and to be multiparous (aOR = 3.57, 95%CI 1.62–7.89). Anaemia (aOR = 13.5, 95%CI 3.17–57.6) and immunosuppression (aOR = 15.0, 95%CI 1.93–116.9) were the two most important factors driving the association between medical comorbidities and progression to death.

Conclusions

There must be continued vigilance for the risks of infection in pregnant women with medical comorbidities. Improved adherence to national guidelines, alongside prompt recognition and treatment with antibiotics, may reduce the burden from sepsis‐related maternal deaths.

Tweetable abstract

Medical comorbidities, multiparity and antibiotic delays increase the risk of death from maternal sepsis.

Utilizing CX3CR1GFP/PGRPdsRed reporter mice to monitor myeloid and granulocyte responses during helminth infection (MPF6P.652)

CX3CR1GFP/PGRPdsRed reporter mice have previously been used to monitor trafficking of monocytes and neutrophils, respectively. With this new tool, we examined myeloid cell and neutrophil behavior during murine infection with the helminth, Nippostrongylus brasiliensis (Nb). Nb acutely infects the lungs leading to significant infiltration of PGRPdsRed neutrophils and CX3CR1GFP monocytes compared to naïve mice. Using ex vivo time-lapse confocal microscopy, we discovered that Nb infection increased chemotaxis of CX3CR1GFP monocytes and PGRPdsRed neutrophils. Because CX3CR1GFP expression is a loss of function knock-in mutation, we tested the function of CX3CR1 in the immune response to Nb. After inoculation with infective larvae, CX3CR1GFP mice were less susceptible to infection compared to wild-type mice and had lower worm counts and parasite eggs in the feces. Additionally, ATP cell viability assay revealed that worms recovered from reporter mice were less viable than worms isolated from wild-type mice. Taken together, CX3CR1GFP/PGRPdsRed mice make it possible to monitor myeloid cell and neutrophil behavior, and reveal a previously unrecognized role for CX3CR1 in impairing Nb expulsion.

A role for dectin-1 in the CNS during chronic Toxoplasma gondii infection (MPF5P.739)

The latent stage of T.gondii infection is characterized by the formation of tissue cysts within the CNS. These tissue cysts are formed by manipulation of the parasitophorous vacuole, and chitin is a structural component of the cyst wall. Our lab has shown that Toxoplasma cysts induce an M2 phenotype in macrophages in a contact-dependent manner. Upon contact, these macrophages actively secrete the mammalian chitinase, AMCase, to break down the cyst wall. We have previously demonstrated that AMCase production by macrophages is essential for control of cyst burden in the brain during T. gondii infection. The molecular interactions involved in macrophage-cyst recognition, and the signaling pathway for AMCase production are as yet unknown. Although chitin recognition has been poorly defined, studies suggest dectin-1 may be a receptor. Here, we present data on a role for dectin-1 during T. gondii infection. Dectin-1 is upregulated in the brain in response to infection and is expressed on arginase-1+, M2 macrophages. Consistent with dectin-1 expression on M2 macrophages, dectin-1 is not required to control parasite burden or induce an inflammatory immune response in vivo. However, dectin-1 deficient mice do exhibit trends towards decreased cyst numbers in the brain and a concomitant increase in AMCase transcripts and AMCase activity ex vivo. Thus, this data suggests that dectin-1 is modulating the immune response and chitinase production during chronic Toxoplasma infection.

The human protein resistin drives detrimental inflammatory monocyte responses in helminth infection (MPF7P.710)

Resistin-like molecules (RELM) belong to a family of secreted proteins that are expressed in multiple helminth infections with important effects on the host immune response. However the importance of human RELM proteins in helminth infections is less well understood. To investigate this, we utilized transgenic mice that expressed the human resistin gene (Tg+). Following infection with Nippostrongylus brasiliensis, a hookworm that colonizes the lung and intestine, Tg+ mice exhibited significant lung inflammation, characterized by increased inflammatory monocytes and elevated parasite burdens compared to control Tg- mice. Genome-wide transcriptional profiling of the infected lung tissue from Tg+ and Tg- mice revealed that genes associated with cytokine and TLR signaling were significantly elevated in Tg+ mice. To delineate the downstream cellular mediators of resistin, we performed a resistin binding and chemotaxis assay and identified monocytes as the main cell-types that were responsive to resistin. Moreover, monocytes sorted from the infected lung tissue of Tg+ mice expressed significantly higher TNFα compared to Tg- mice. In human studies, increased serum resistin was associated with higher helminth burdens and was positively correlated with inflammatory cytokines. Together, these studies identify a detrimental role for human resistin in instigating a non-protective inflammatory response that may be mediated by monocytes.

Factors associated with maternal death from direct pregnancy complications: a UK national case-control study

OBJECTIVE

To investigate the factors associated with maternal death from direct pregnancy complications in the UK.

DESIGN

Unmatched case-control analysis.

SETTING

All hospitals caring for pregnant women in the UK.

POPULATION

A total of 135 women who died (cases) between 2009 and 2012 from eclampsia, pulmonary embolism, severe sepsis, amniotic fluid embolism, and peripartum haemorrhage, using data from the Confidential Enquiry into Maternal Death, and another 1661 women who survived severe complications (controls) caused by these conditions (2005-2013), using data from the UK Obstetric Surveillance System.

METHODS

Multivariable regression analyses were undertaken to identify the factors that were associated with maternal deaths and to estimate the additive odds associated with the presence of one or more of these factors.

MAIN OUTCOME MEASURES

Odds ratios associated with maternal death and population-attributable fractions, with 95% confidence intervals. Incremental risk of death associated with the factors using a 'risk factors' score.

RESULTS

Six factors were independently associated with maternal death: inadequate use of antenatal care (adjusted odds ratio, aOR 15.87, 95% CI 6.73-37.41); substance misuse (aOR 10.16, 95% CI 1.81-57.04); medical comorbidities (aOR 4.82, 95% CI 3.14-7.40); previous pregnancy problems (aOR 2.21, 95% CI 1.34-3.62); hypertensive disorders of pregnancy (aOR 2.44, 95% CI 1.31-4.52); and Indian ethnicity (aOR 2.70, 95% CI 1.14-6.43). Of the increased risk associated with maternal death, 70% (95% CI 66-73%) could be attributed to these factors. Odds associated with maternal death increased by three and a half times per unit increase in the 'risk factor' score (aOR 3.59, 95% CI 2.83-4.56).

CONCLUSIONS

This study shows that medical comorbidities are importantly associated with direct (obstetric) deaths. Further studies are required to understand whether specific aspects of care could be improved to reduce maternal deaths among women with medical comorbidities in the UK.

The involvement of J-protein AtDjC17 in root development in Arabidopsis

In a screen for root hair morphogenesis mutants in Arabidopsis thaliana L. we identified a T-DNA insertion within a type III J-protein AtDjC17 caused altered root hair development and reduced hair length. Root hairs were observed to develop from trichoblast and atrichoblast cell files in both Atdjc17 and 35S::AtDJC17. Localization of gene expression in the root using transgenic plants expressing proAtDjC17::GUS revealed constitutive expression in stele cells. No AtDJC17 expression was observed in epidermal, endodermal, or cortical layers. To explore the contrast between gene expression in the stele and epidermal phenotype, hand cut transverse sections of Atdjc17 roots were examined showing that the endodermal and cortical cell layers displayed increased anticlinal cell divisions. Aberrant cortical cell division in Atdjc17 is proposed as causal in ectopic root hair formation via the positional cue requirement that exists between cortical and epidermal cell in hair cell fate determination. Results indicate a requirement for AtDJC17 in position-dependent cell fate determination and illustrate an intriguing requirement for molecular co-chaperone activity during root development.