A Systematic Investigation on Complement Pathway Activation in Diabetic Retinopathy

The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition of complement proteins, their exact role in the pathogenesis of DR is yet unclear. We performed a detailed investigation of the role of the complement system by evaluating the levels of major complement proteins including C3, C1q, C4b, Complement Factor B (CFB), and Complement Factor H (CFH) and their activated fragments from both the classical and alternative pathways in vitreous humor and serum samples from proliferative DR (PDR) patients and controls. Further, the expressions of complements and several other key pro- and anti-angiogenic genes in the serum and vitreous humor were analyzed in the blood samples of PDR and non-PDR (NPDR) patients along with controls without diabetes. We also assessed the pro-inflammatory cytokines and matrix metalloproteinases in the vitreous humor samples. There was a significant increase in C3 and its activated fragment C3bα' (110 kDa) along with a corresponding upregulation of CFH in the vitreous of PDR patients, which confirmed the increased activation of the alternative complement pathway in PDR. Likewise, a significant upregulation of angiogenic genes and downregulation of anti-angiogenic genes was seen in PDR and NPDR cases. Increased MMP9 activity and upregulation of inflammatory markers IL8 and sPECAM with a downregulation of anti-inflammatory marker IL-10 in PDR vitreous indicated the possible involvement of microglia in DR pathogenesis. Further, a significantly high C3 deposition in the capillary wall along with thickening of basement membranes and co-localization of CFH expression with CD11b^+ve activated microglial cells in diabetic retina suggested microglia as a source of CFH in diabetic retina. The increased CFH levels could be a feedback mechanism for arresting excessive complement activation in DR eyes. A gradual increase of CFH and CD11b expression in retina with early to late changes in epiretinal membranes of DR patients indicated a major role for the alternative complement pathway in disease progression.

A Robust Model System for Retinal Hypoxia: Live Imaging of Calcium Dynamics and Gene Expression Studies in Primary Human Mixed Retinal Culture

The detailed mechanisms underlying oxidative stress that leads to neuroinflammation and neurodegeneration in retinal vascular conditions, including diabetic retinopathy, retinopathy of prematurity etc., remain largely unexplored mainly due to a lack of suitable disease models that can simulate the inherent neuron-glia interactions in human retina. Specifically, establishment of a mixed retinal culture (MRC) containing both neuron and glial cell types remains a challenge due to different conditions required for their optimal growth and differentiation. Here, we establish a novel primary MRC model system containing neurons, astrocytes, Müller glia, and microglia from human donor retina that can be used to study the neuromodulatory effects of glial cells under the stress. The cell characterization based on immunostaining with individual cell type-specific markers and their presence in close vicinity to each other further underscores their utility for studying their cross talk. To the best of our knowledge, this is the first instance of an in vitro model obtained from human donor retina containing four major cell types. Next, we induce hypoxic stress to MRC to investigate if hypoxia activated neuroglia modulates altered gene expression for inflammatory, apoptotic, and angiogenic markers and Ca²⁺ transients by live cell imaging. Further, we performed k-means clustering of the Ca²⁺ responses to identify the modification of clustering pattern in stressed condition. Finally, we provide the evidence that the altered Ca²⁺ transient correlates to differential expression of genes shown to be involved in neuroinflammation, angiogenesis, and neurodegeneration under the hypoxic conditions as seen earlier in human cell lines and animal models of diabetic retinopathy. The major features of the hypoxic conditions in the proposed human MRC model included: increase in microglia activity, chemokine and cytokine expression, and percentage of cells having higher amplitude and frequency of Ca²⁺ transients. Thus, the proposed experimental system can potentially serve as an ideal in vitro model for studying the neuroinflammatory and neurodegenerative changes in the retina and identifying newer drug targets.

Automatic Identification of Mixed Retinal Cells in Time-Lapse Fluorescent Microscopy Images using High-Dimensional DBSCAN

Despite providing high spatial resolution, functional imaging remains largely unsuitable for high-throughput experiments because current practices require cells to be manually identified in a time-consuming procedure. Against this backdrop, we seek to integrate such high-resolution technique in high-throughput workflow by automating the process of cell identification. As a step forward, we attempt to identify mixed retinal cells in time-lapse fluorescent microscopy images. Unfortunately, usual 2D image segmentation as well as other existing methods do not adequately distinguish between time courses of different spatial locations. Here, the task gets further complicated due to the inherent heterogeneity of cell morphology. To overcome such challenge, we propose to use a high-dimensional (HiD) version of DBSCAN (density based spatial clustering of applications with noise) algorithm, where difference in such time courses are appropriately accounted. Significantly, outcome of the proposed method matches manually identified cells with over 80% accuracy, marking more than 50% improvement compared to a reference 2D method.

Plasmodium falciparum GCN5 acetyltransferase follows a novel proteolytic processing pathway that is essential for its function

The pathogenesis of human malarial parasite Plasmodium falciparum is interlinked with its timely control of gene expression during its complex life cycle. In this organism, gene expression is partially controlled through epigenetic mechanisms, the regulation of which is, hence, of paramount importance to the parasite. The P. falciparum (Pf)-GCN5 histone acetyltransferase (HAT), an essential enzyme, acetylates histone 3 and regulates global gene expression in the parasite. Here, we show the existence of a novel proteolytic processing for PfGCN5 that is crucial for its activity in vivo We find that a cysteine protease-like enzyme is required for the processing of PfGCN5 protein. Immunofluorescence and immuno-electron microscopy analysis suggest that the processing event occurs in the vicinity of the digestive vacuole of the parasite following its trafficking through the classical ER-Golgi secretory pathway, before it subsequently reaches the nucleus. Furthermore, blocking of PfGCN5 processing leads to the concomitant reduction of its occupancy at the gene promoters and a reduced H3K9 acetylation level at these promoters, highlighting the important correlation between the processing event and PfGCN5 activity. Altogether, our study reveals a unique processing event for a nuclear protein PfGCN5 with unforeseen role of a food vacuolar cysteine protease. This leads to a possibility of the development of new antimalarials against these targets.This article has an associated First Person interview with the first author of the paper.

Serum Small Extracellular Vesicles Proteome of Tuberculosis Patients Demonstrated Deregulated Immune Response

PURPOSE

Detailed understanding of host pathogen interaction in tuberculosis is an important avenue for identifying novel therapeutic targets. Small extracellular vesicles (EVs) like exosomes that are rich in proteins, nucleic acids and lipids, act as messengers and may show altered composition in disease conditions.

EXPERIMENTAL DESIGN

In this case control study, small EVs are isolated from serum of 58 subjects (all male, 33 (15-70) in years) including drug naïve active tuberculosis (ATB: n = 22), non-tuberculosis (NTB: n = 18), and healthy subjects (n = 18). Serum small EVs proteome analysis is carried out using isobaric tag for relative and absolute quantification (iTRAQ) experiments and an independent sample (n = 36) is used for validation.

RESULTS

A set of 132 and 68 proteins are identified in iTRAQ-I (ATB/Healthy) and iTRAQ-II (ATB/NTB) experiments, respectively. Four proteins (KYAT3, SERPINA1, HP, and APOC3) show deregulation (log₂ -fold change > ±0.48, p < 0.05) in ATB with respect to healthy controls and Western blot data corroborated mass spectrometry findings.

CONCLUSIONS AND CLINICAL RELEVANCE

These important proteins, involved in neutrophil degranulation, plasma heme scavenging, kynurenine, and lipid metabolism, show deregulation in ATB patients. Identification of such a protein panel in circulating small EVs besides providing novel insights into their role in tuberculosis may prove to be useful targets to develop host-directed therapeutic intervention.

ENT infection caused by Raoultella ornithinolytica

Raoultella ornithinolytica is an encapsulated gram-negative aerobic bacillus belonging to the Enterobacteriaceae family. It is one of the three species of Raoultella. Human infections related to R. ornithinolytica are exceedingly rare. This case report describes an ENT infection caused by R. ornithinolytica successfully treated with antibiotic therapy.

Hamartomatous polyp of the tonsil: A case report

Hamartomatous polyps of the tonsil are rare. They have been described using various terms such as a lymphangiomatous polyp, lymphangiectatic fibrous polyp, lipomatous polyp, or pedunculated tonsil; hence, the actual incidence is difficult to be quantified. Polyp of the palatine tonsils is an unusual benign lesion of the head and neck. It is a rare polypoidal mass that generally arises from a pedicle attached to the tonsil and projecting into the oropharynx. Polypoid lesions of the head and neck are likewise rare, and such tumors arising from the palatine tonsils are sparse. Tonsillar polyp is an uncommon hamartomatous lesion that generally arises from the tonsillar surface. It has rarely been reported in the medical literature. We present a case of hamartomatous polyp of the palatine tonsil in a 17-year-old male patient.

Maternal and perinatal mortality and complications associated with caesarean section in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Universal and timely access to a caesarean section is a key requirement for safe childbirth. We identified the burden of maternal and perinatal mortality and morbidity, and the risk factors following caesarean sections in low-income and middle-income countries (LMICs).

METHODS

For this systematic review and meta-analysis, we searched electronic databases including MEDLINE and Embase (from Jan 1, 1990, to Nov 20, 2017), without language restrictions, for studies on maternal or perinatal outcomes following caesarean sections in LMICs. We excluded studies in high-income countries, those involving non-pregnant women, case reports, and studies published before 1990. Two reviewers undertook the study selection, quality assessment, and data extraction independently. The main outcome being assessed was prevalence of maternal mortality in women undergoing caesarean sections in LMICs. We used a random effects model to synthesise the rate data, and reported the association between risk factors and outcomes using odds ratios with 95% CIs. The study protocol has been registered with PROSPERO, number CRD42015029191.

FINDINGS

We included 196 studies from 67 LMICs. The risk of maternal death in women who had a caesarean section (116 studies, 2 933 457 caesarean sections) was 7·6 per 1000 procedures (95% CI 6·6-8·6, τ²=0·81); the highest burden was in sub-Saharan Africa (10·9 per 1000; 9·5-12·5, τ²=0·81). A quarter of all women who died in LMICs (72 studies, 27 651 deaths) had undergone a caesarean section (23·8%, 95% CI 21·0-26·7; τ²=0·62).

INTERPRETATION

Maternal deaths and perinatal deaths following caesarean sections are disproportionately high in LMICs. The timing and urgency of caesarean section pose major risks.

FUNDING

Ammalife Charity and ELLY Appeal, Barts Charity, and the UK National Institute for Health Research.

Metabolomics Applicable to Retinal Vascular Diseases

Metabolomics refers to the systematic identification and quantification of the small molecule metabolites (the metabolome) of a biological system in a given space (cell, tissue, organ, biological fluid, or organism) and time. Global metabolic profiling provides broad range of coverage for most of the analytes present in any tissue. Human retina is metabolically highly active, and retinal vascular diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), retinal vein occlusion (RVO), central retinal artery occlusion, and retinopathy of prematurity (ROP) are often associated with the disruptions in metabolic activities. A systematic study of total retinal metabolites from human diseased retina is a major challenge owing to the nonavailability of tissue specimens. Therefore, vitreous humor being very proximal to retina could be used as surrogate for retinal metabolomic analysis. As the extraction method adopted for such analysis determines the type of metabolites, two different types of solvent (methanol and chloroform)-based extraction methods could be used for retinal vascular patient samples (vitreous humor). Metabolites obtained from both the extraction methods are then subjected to LC-MS/MS for detection and identification.

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

Introduction

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

Materials and Methods

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

Results

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

Conclusion

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

Testing the effectiveness of REACH Pregnancy Circles group antenatal care: protocol for a randomised controlled pilot trial

BACKGROUND

Antenatal care is an important public health priority. Women from socially disadvantaged, and culturally and linguistically diverse groups often have difficulties with accessing antenatal care and report more negative experiences with care. Although group antenatal care has been shown in some settings to be effective for improving women's experiences of care and for improving other maternal as well as newborn health outcomes, these outcomes have not been rigorously assessed in the UK. A pilot trial will be conducted to determine the feasibility of, and optimum methods for, testing the effectiveness of group antenatal care in an NHS setting serving populations with high levels of social deprivation and cultural, linguistic and ethnic diversity. Outcomes will inform the protocol for a future full trial.

METHODS

This protocol outlines an individual-level randomised controlled external pilot trial with integrated process and economic evaluations. The two trial arms will be group care and standard antenatal care. The trial will involve the recruitment of 72 pregnant women across three maternity services within one large NHS Acute Trust. Baseline, outcomes and economic data will be collected via questionnaires completed by the participants at three time points, with the final scheduled for 4 months postnatal. Routine maternity service data will also be collected for outcomes assessment and economic evaluation purposes. Stakeholder interviews will provide insights into the acceptability of research and intervention processes, including the use of interpreters to support women who do not speak English. Pre-agreed criteria have been selected to guide the decision about whether or not to progress to a full trial.

DISCUSSION

This pilot trial will determine if it is appropriate to proceed to a full trial of group antenatal care in this setting. If progression is supported, the pilot will provide authoritative high-quality evidence to inform the design and conduct of a trial in this important area that holds significant potential to influence maternity care, outcomes and experience.

TRIAL REGISTRATION

ISRCTN ISRCTN66925258. Registered 03 April 2017. Retrospectively registered.

Is sino-nasal outcome test-22 reliable for guiding chronic rhinosinusitis patients for endoscopic sinus surgery?

Chronic rhino-sinusitis (CRS) is a significant health problem whose incidence and prevalence is rising. An emphasis has been placed on diseasespecific quality of life (QoL as the predominant measure for most current outcome studies. Therefore a validated measure of health-related QoL in sinonasal disease is needed. The present prospective and observational study was conducted on 50 patients in the Department of ENT at Govt. Medical College and Rajindra Hospital Patiala, Punjab, India. The primary outcomes were the following: (1) the chance of attaining minimal clinically important difference (MCID) improvements of nine points at the 22-item Sino-Nasal Outcome Test (SNOT-22) after endoscopic sinus surgery (ESS) for different preoperative QoL levels, and (2) the percentage of relative improvement in SNOT-22 after ESS for different preoperative QoL levels.

Methods

Patients with CRS who were elected for ESS were prospectively enrolled into an observational cohort study. They were categorized into 10 preoperative SNOT-22 groups based on 10-point increments beginning with a score of 10 and ending at 110. Standard protocol for all patients presenting for evaluation included completion of the SNOT-22 prior to and following surgical intervention. The scores were calculated and the data collected were compiled and analyzed.

Results

A total of 50 patients were included in this study. Patients with a SNOT-22 score between 10 and 19 had the lowest chance of achieving an MCID. Patients with a SNOT-22 score greater than 30 had a greater than 90% chance of achieving an MCID, and there was a relative improvement of 43.3% on their preoperative SNOT-22 scores. CRS patients with polyp had better outcomes (47.1% improvement) after ESS than those without polyp (33.2% improvement).

Conclusion

There is an increased probability of achieving an MCID at SNOT-22 score >30 and in general the percentage of relative improvement increased with an increase in preoperative SNOT score.

Calcium-dependent phosphorylation of Plasmodium falciparum serine repeat antigen 5 triggers merozoite egress

The human malaria parasite Plasmodium falciparum proliferates in red blood cells following repeated cycles of invasion, multiplication, and egress. P. falciparum serine repeat antigen 5 (PfSERA5), a putative serine protease, plays an important role in merozoite egress. However, regulation of its activity leading to merozoite egress is poorly understood. In this study, we show that PfSERA5 undergoes phosphorylation prior to merozoite egress. Immunoprecipitation of parasite lysates using anti-PfSERA5 serum followed by MS analysis identified calcium-dependent protein kinase 1 (PfCDPK1) as an interacting kinase. Association of PfSERA5 with PfCDPK1 was corroborated by co-sedimentation, co-immunoprecipitation, and co-immunolocalization analyses. Interestingly, PfCDPK1 phosphorylated PfSERA5 in vitro in the presence of Ca²⁺ and enhanced its proteolytic activity. A PfCDPK1 inhibitor, purfalcamine, blocked the phosphorylation and activation of PfSERA5 both in vitroas well as in schizonts, which, in turn, blocked merozoite egress. Together, these results suggest that phosphorylation of PfSERA5 by PfCDPK1 following a rise in cytosolic Ca²⁺ levels activates its proteolytic activity to trigger merozoite egress.

Evaluation of community-level interventions to increase early initiation of antenatal care in pregnancy: protocol for the Community REACH study, a cluster randomised controlled trial with integrated process and economic evaluations

Background

The provision of high-quality maternity services is a priority for reducing inequalities in health outcomes for mothers and infants. Best practice includes women having their initial antenatal appointment within the first trimester of pregnancy in order to provide screening and support for healthy lifestyles, well-being and self-care in pregnancy. Previous research has identified inequalities in access to antenatal care, yet there is little evidence on interventions to improve early initiation of antenatal care. The Community REACH trial will assess the effectiveness and cost-effectiveness of engaging communities in the co-production and delivery of an intervention that addresses this issue.

Methods/design

The study design is a matched cluster randomised controlled trial with integrated process and economic evaluations. The unit of randomisation is electoral ward. The intervention will be delivered in 10 wards; 10 comparator wards will have normal practice. The primary outcome is the proportion of pregnant women attending their antenatal booking appointment by the 12th completed week of pregnancy. This and a number of secondary outcomes will be assessed for cohorts of women (n = approximately 1450 per arm) who give birth 2–7 and 8–13 months after intervention delivery completion in the included wards, using routinely collected maternity data. Eight hospitals commissioned to provide maternity services in six NHS trusts in north and east London and Essex have been recruited to the study. These trusts will provide anonymised routine data for randomisation and outcomes analysis. The process evaluation will examine intervention implementation, acceptability, reach and possible causal pathways. The economic evaluation will use a cost-consequences analysis and decision model to evaluate the intervention. Targeted community engagement in the research process was a priority.

Discussion

Community REACH aims to increase early initiation of antenatal care using an intervention that is co-produced and delivered by local communities. This pragmatic cluster randomised controlled trial, with integrated process and economic evaluation, aims to rigorously assess the effectiveness of this public health intervention, which is particularly complex due to the required combination of standardisation with local flexibility. It will also answer questions about scalability and generalisability.

Trial registration

ISRCTN registry: registration number 63066975. Registered on 18 August 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2526-6) contains supplementary material, which is available to authorized users.

Diagnostic Electron Microscopy of Retina

The electron microscopy techniques were used in various fields as an analytical technique under in vitro conditions, which provides the sufficient resolution for better visualization and interpretation. This review gives a brief overview of the analytical application of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques and critical findings in different retinal pathologies. This review article aims to improvise understanding of retinal microstructures for clinicians which will help to improve the interpretation of the current advanced imaging techniques.