Identification and risk stratification of coronary disease by artificial intelligence-enabled ECG

Background

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide, driven primarily by coronary artery disease (CAD). ASCVD risk estimators such as the pooled cohort equations (PCE) facilitate risk stratification and primary prevention of ASCVD but their accuracy is still suboptimal.

Methods

Using deep electronic health record data from 7,116,209 patients seen at 70+ hospitals and clinics across 5 states in the USA, we developed an artificial intelligence-based electrocardiogram analysis tool (ECG-AI) to detect CAD and assessed the additive value of ECG-AI-based ASCVD risk stratification to the PCE. We created independent ECG-AI models using separate neural networks including subjects without known history of ASCVD, to identify coronary artery calcium (CAC) score ≥300 Agatston units by computed tomography, obstructive CAD by angiography or procedural intervention, and regional left ventricular akinesis in ≥1 segment by echocardiogram, as a reflection of possible prior myocardial infarction (MI). These were used to assess the utility of ECG-AI-based ASCVD risk stratification in a retrospective observational study consisting of patients with PCE scores and no prior ASCVD. The study period covered all available digitized EHR data, with the first available ECG in 1987 and the last in February 2023.

Findings

ECG-AI for identifying CAC ≥300, obstructive CAD, and regional akinesis achieved area under the receiver operating characteristic (AUROC) values of 0.88, 0.85, and 0.94, respectively. An ensembled ECG-AI identified 3, 5, and 10-year risk for acute coronary events and mortality independently and additively to PCE. Hazard ratios for acute coronary events over 3-years in patients without ASCVD that tested positive on 1, 2, or 3 versus 0 disease-specific ECG-AI models at cohort entry were 2.41 (2.14-2.71), 4.23 (3.74-4.78), and 11.75 (10.2-13.52), respectively. Similar stratification was observed in cohorts stratified by PCE or age.

Interpretation

ECG-AI has potential to address unmet need for accessible risk stratification in patients in whom PCE under, over, or insufficiently estimates ASCVD risk, and in whom risk assessment over time periods shorter than 10 years is desired.

Funding

Anumana.

Effect of surgical intervention on serum insulin-like growth factor 1 in patients with obstructive sleep apnoea

OBJECTIVE

To evaluate the effect of surgical intervention on serum insulin-like growth factor 1 levels in patients with obstructive sleep apnoea.

METHODS

A prospective study was conducted in a tertiary care hospital of adult patients with obstructive sleep apnoea for whom continuous positive airway pressure therapy failed or was refused. All patients underwent polysomnography and serum insulin-like growth factor 1 evaluation pre-operatively and at three months post-operatively. The site of surgery was determined using Müller's manoeuvre and ApneaGraph AG 200.

RESULTS

Fifteen patients were included with a mean age of 38 years: 11 males and 4 females. The mean pre-operative Apnoea-Hypopnoea Index using polysomnography was 53.7 events per hour, and the mean post-operative Apnoea-Hypopnoea Index at three months was 15.3 events per hour (p = 0.0001). The mean pre-operative serum insulin-like growth factor 1 was 160.2 μg/l, while the mean post-operative value was 236.98 μg/l (p = 0.005).

CONCLUSION

In adult patients with obstructive sleep apnoea for whom continuous positive airway pressure therapy fails, site-specific surgical intervention to treat the obstruction leads to an increase in serum insulin-like growth factor 1 levels.

Genome-wide mapping of gene-microbe interactions in the murine lung microbiota based on quantitative microbial profiling

BACKGROUND

Mammalian lungs comprise a complex microbial ecosystem that interacts with host physiology. Previous research demonstrates that the environment significantly contributes to bacterial community structure in the upper and lower respiratory tract. However, the influence of host genetics on the makeup of lung microbiota remains ambiguous, largely due to technical difficulties related to sampling, as well as challenges inherent to investigating low biomass communities. Thus, innovative approaches are warranted to clarify host-microbe interactions in the mammalian lung.

RESULTS

Here, we aimed to characterize host genomic regions associated with lung bacterial traits in an advanced intercross mouse line (AIL). By performing quantitative microbial profiling (QMP) using the highly precise method of droplet digital PCR (ddPCR), we refined 16S rRNA gene amplicon-based traits to identify and map candidate lung-resident taxa using a QTL mapping approach. In addition, the two abundant core taxa Lactobacillus and Pelomonas were chosen for independent microbial phenotyping using genus-specific primers. In total, this revealed seven significant loci involving eight bacterial traits. The narrow confidence intervals afforded by the AIL population allowed us to identify several promising candidate genes related to immune and inflammatory responses, cell apoptosis, DNA repair, and lung functioning and disease susceptibility. Interestingly, one genomic region associated with Lactobacillus abundance contains the well-known anti-inflammatory cytokine Il10, which we confirmed through the analysis of Il10 knockout mice.

CONCLUSIONS

Our study provides the first evidence for a role of host genetic variation contributing to variation in the lung microbiota. This was in large part made possible through the careful curation of 16S rRNA gene amplicon data and the incorporation of a QMP-based methods. This approach to evaluating the low biomass lung environment opens new avenues for advancing lung microbiome research using animal models.

Protein structure-based in-silico approaches to drug discovery: Guide to COVID-19 therapeutics

With more than 5 million fatalities and close to 300 million reported cases, COVID-19 is the first documented pandemic due to a coronavirus that continues to be a major health challenge. Despite being rapid, uncontrollable, and highly infectious in its spread, it also created incentives for technology development and redefined public health needs and research agendas to fast-track innovations to be translated. Breakthroughs in computational biology peaked during the pandemic with renewed attention to making all cutting-edge technology deliver agents to combat the disease. The demand to develop effective treatments yielded surprising collaborations from previously segregated fields of science and technology. The long-standing pharmaceutical industry's aversion to repurposing existing drugs due to a lack of exponential financial gain was overrun by the health crisis and pressures created by front-line researchers and providers. Effective vaccine development even at an unprecedented pace took more than a year to develop and commence trials. Now the emergence of variants and waning protections during the booster shots is resulting in breakthrough infections that continue to strain health care systems. As of now, every protein of SARS-CoV-2 has been structurally characterized and related host pathways have been extensively mapped out. The research community has addressed the druggability of a multitude of possible targets. This has been made possible due to existing technology for virtual computer-assisted drug development as well as new tools and technologies such as artificial intelligence to deliver new leads. Here in this article, we are discussing advances in the drug discovery field related to target-based drug discovery and exploring the implications of known target-specific agents on COVID-19 therapeutic management. The current scenario calls for more personalized medicine efforts and stratifying patient populations early on for their need for different combinations of prognosis-specific therapeutics. We intend to highlight target hotspots and their potential agents, with the ultimate goal of using rational design of new therapeutics to not only end this pandemic but also uncover a generalizable platform for use in future pandemics.

A phase II study of metformin plus pemetrexed and carboplatin in patients with non-squamous non-small cell lung cancer (METALUNG)

Immune checkpoint inhibitors (ICIs) ± chemotherapy is the standard treatment for driver mutation-negative non-small cell lung cancer (NSCLC). However, accessibility to ICIs in LMICs is limited due to high cost, and platinum-based chemotherapy remains the mainstay of treatment. Metformin has anticancer properties, and studies suggest synergism between metformin and pemetrexed. Based on preclinical evidence, this combination may be more beneficial for STK11-mutated NSCLC, a subgroup, inherently resistant to ICIs. In this Simon two-stage, single-arm phase 2 trial, we investigated metformin with pemetrexed-carboplatin (PC) in patients with treatment-naive stage IV non-squamous NSCLC. The primary outcome was 6-month progression-free survival (PFS) rate. Secondary outcomes were safety, overall survival (OS), overall response rate (ORR), proportion of STK11 mutation, and effect of STK11 mutation on 6-month PFS rate. The study was terminated for futility after interim analysis. The median follow-up was 34.1 months. The 6-month PFS rate was 28% (95% CI 12.4-0.46). The median PFS and OS were 4.5 (95% CI 2.2-6.1) and 7.4 months (95% CI 5.3-15.3), respectively. The ORR was 72%. Gastrointestinal toxicities were the most common. No grade 4/5 toxicities were reported. Targeted sequencing was possible in nine cases. Two patients had STK11 mutation and a poor outcome (PFS < 12 weeks). We could not demonstrate the benefit of metformin with CP in terms of improvement in 6-month PFS rate; however, the combination was safe (CTRI/2019/02/017815).

Blockchain-enabled immutable, distributed, and highly available clinical research activity logging system for federated COVID-19 data analysis from multiple institutions

OBJECTIVE

We aimed to develop a distributed, immutable, and highly available cross-cloud blockchain system to facilitate federated data analysis activities among multiple institutions.

MATERIALS AND METHODS

We preprocessed 9166 COVID-19 Structured Query Language (SQL) code, summary statistics, and user activity logs, from the GitHub repository of the Reliable Response Data Discovery for COVID-19 (R2D2) Consortium. The repository collected local summary statistics from participating institutions and aggregated the global result to a COVID-19-related clinical query, previously posted by clinicians on a website. We developed both on-chain and off-chain components to store/query these activity logs and their associated queries/results on a blockchain for immutability, transparency, and high availability of research communication. We measured run-time efficiency of contract deployment, network transactions, and confirmed the accuracy of recorded logs compared to a centralized baseline solution.

RESULTS

The smart contract deployment took 4.5 s on an average. The time to record an activity log on blockchain was slightly over 2 s, versus 5-9 s for baseline. For querying, each query took on an average less than 0.4 s on blockchain, versus around 2.1 s for baseline.

DISCUSSION

The low deployment, recording, and querying times confirm the feasibility of our cross-cloud, blockchain-based federated data analysis system. We have yet to evaluate the system on a larger network with multiple nodes per cloud, to consider how to accommodate a surge in activities, and to investigate methods to lower querying time as the blockchain grows.

CONCLUSION

Blockchain technology can be used to support federated data analysis among multiple institutions.

A critical role for erythropoietin on vagus nerve Schwann cells in intestinal motility

BACKGROUND

Dysmotility and postoperative ileus (POI) are frequent major clinical problems post-abdominal surgery. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine that promotes recovery of the intestine in various injury models. While EPO receptors (EPOR) are present in vagal Schwann cells, the role of EPOR in POI recovery is unknown because of the lack of EPOR antagonists or Schwann-cell specific EPOR knockout animals. This study was designed to explore the effect of EPO via EPOR in vagal nerve Schwann cells in a mouse model of POI.

RESULTS

The structural features of EPOR and its activation by EPO-mediated dimerization were understood using structural analysis. Later, using the Cre-loxP system, we developed a myelin protein zero (Mpz) promoter-driven knockout mouse model of Schwann cell EPOR (MpzCre-EPOR^flox/flox / Mpz-EPOR-KO) confirmed using PCR and qRT-PCR techniques. We then measured the intestinal transit time (ITT) at baseline and after induction of POI with and without EPO treatment. Although we have previously shown that EPO accelerates functional recovery in POI in wild type mice, EPO treatment did not improve functional recovery of ITT in POI of Mpz-EPOR-KO mice.

CONCLUSIONS

To the best of our knowledge, this is the first pre-clinical study to demonstrate a novel mouse model of EPOR specific knock out on Schwan cells with an effect in the gut. We also showed novel beneficial effects of EPO through vagus nerve Schwann cell-EPOR in intestinal dysmotility. Our findings suggest that EPO-EPOR signaling in the vagus nerve after POI is important for the functional recovery of ITT.

Mycolactone: A Broad Spectrum Multitarget Antiviral Active in the Picomolar Range for COVID-19 Prevention and Cure

We have previously shown computationally that Mycolactone (MLN), a toxin produced by Mycobacterium ulcerans, strongly binds to Munc18b and other proteins, presumably blocking degranulation and exocytosis of blood platelets and mast cells. We investigated the effect of MLN on endocytosis using similar approaches, and it bound strongly to the N-terminal of the clathrin protein and a novel SARS-CoV-2 fusion protein. Experimentally, we found 100% inhibition up to 60 nM and 84% average inhibition at 30 nM in SARS-CoV-2 live viral assays. MLN was also 10× more potent than remdesivir and molnupiravir. MLN's toxicity against human alveolar cell line A549, immortalized human fetal renal cell line HEK293, and human hepatoma cell line Huh7.1 were 17.12%, 40.30%, and 36.25%, respectively. The cytotoxicity IC₅₀ breakpoint ratio versus anti-SARS-CoV-2 activity was more than 65-fold. The IC₅₀ values against the alpha, delta, and Omicron variants were all below 0.020 µM, and 134.6 nM of MLN had 100% inhibition in an entry and spread assays. MLN is eclectic in its actions through its binding to Sec61, AT2R, and the novel fusion protein, making it a good drug candidate for treating and preventing COVID-19 and other similarly transmitted enveloped viruses and pathogens.

Carborane-Containing Hydroxamate MMP Ligands for the Treatment of Tumors Using Boron Neutron Capture Therapy (BNCT): Efficacy without Tumor Cell Entry

New carborane-bearing hydroxamate matrix metalloproteinase (MMP) ligands have been synthesized for boron neutron capture therapy (BNCT) with nanomolar potency against MMP-2, -9 and -13. New analogs are based on MMP inhibitor CGS-23023A, and two previously reported MMP ligands 1 (B1) and 2 (B2) were studied in vitro for BNCT activity. The boronated MMP ligands 1 and 2 showed high in vitro tumoricidal effects in an in vitro BNCT assay, exhibiting IC₅₀ values for 1 and 2 of 2.04 × 10^-2 mg/mL and 2.67 × 10^-2 mg/mL, respectively. The relative killing effect of 1 to L-boronophenylalanine (BPA) is 0.82/0.27 = 3.0, and that of 2 is 0.82/0.32 = 2.6, whereas the relative killing effect of 4 is comparable to boronophenylalanine (BPA). The survival fraction of 1 and 2 in a pre-incubation boron concentration at 0.143 ppm ¹⁰B and 0.101 ppm ¹⁰B, respectively, were similar, and these results suggest that 1 and 2 are actively accumulated through attachment to the Squamous cell carcinoma (SCC)VII cells. Compounds 1 and 2 very effectively killed glioma U87 delta EGFR cells after BNCT. This study is noteworthy in demonstrating BNCT efficacy through binding to MMP enzymes overexpressed at the surface of the tumor cell without tumor cell penetration.

Structure-Based Identification of Natural-Product-Derived Compounds with Potential to Inhibit HIV-1 Entry

Broadly neutralizing antibodies (bNAbs) are potent in neutralizing a wide range of HIV strains. VRC01 is a CD4-binding-site (CD4-bs) class of bNAbs that binds to the conserved CD4-binding region of HIV-1 envelope (env) protein. Natural products that mimic VRC01 bNAbs by interacting with the conserved CD4-binding regions may serve as a new generation of HIV-1 entry inhibitors by being broadly reactive and potently neutralizing. This study aimed to identify compounds that mimic VRC01 by interacting with the CD4-bs of HIV-1 gp120 and thereby inhibiting viral entry into target cells. Libraries of purchasable natural products were virtually screened against clade A/E recombinant 93TH057 (PDB: 3NGB) and clade B (PDB ID: 3J70) HIV-1 env protein. Protein-ligand interaction profiling from molecular docking and dynamics simulations showed that the compounds had intermolecular hydrogen and hydrophobic interactions with conserved amino acid residues on the CD4-binding site of recombinant clade A/E and clade B HIV-1 gp120. Four potential lead compounds, NP-005114, NP-008297, NP-007422, and NP-007382, were used for cell-based antiviral infectivity inhibition assay using clade B (HXB2) env pseudotype virus (PV). The four compounds inhibited the entry of HIV HXB2 pseudotype viruses into target cells at 50% inhibitory concentrations (IC₅₀) of 15.2 µM (9.7 µg/mL), 10.1 µM (7.5 µg/mL), 16.2 µM (12.7 µg/mL), and 21.6 µM (12.9 µg/mL), respectively. The interaction of these compounds with critical residues of the CD4-binding site of more than one clade of HIV gp120 and inhibition of HIV-1 entry into the target cell demonstrate the possibility of a new class of HIV entry inhibitors.

Data structuring may prevent ambiguity and improve personalized medical prognosis

Topics expected to influence personalized medicine (PM), where medical decisions, practices, and treatments are tailored to the individual patient, are reviewed. Lack of discrimination due to different biological conditions that express similar values of numerical variables (ambiguity) is regarded to be a major potential barrier for PM. This material explores possible causes and sources of ambiguity and offers suggestions for mitigating the impacts of uncertainties. Three causes of ambiguity are identified: (1) delayed adoption of innovations, (2) inadequate emphases, and (3) inadequate processes used when new medical practices are developed and validated. One example of the first problem is the relative lack of medical research on "compositional data" -the type that characterizes leukocyte data. This omission results in erroneous use of data abundantly utilized in medicine, such as the blood cell differential. Emphasis on data output ‒not biomedical interpretation that facilitates the use of clinical data‒ exemplifies the second type of problems. Reliance on tools generated in other fields (but not validated within biomedical contexts) describes the last limitation. Because reductionism is associated with these problems, non-reductionist alternatives are reviewed as potential remedies. Data structuring (converting data into information) is considered a key element that may promote PM. To illustrate a process that includes data-information-knowledge and decision-making, previously published data on COVID-19 are utilized. It is suggested that ambiguity may be prevented or ameliorated. Provided that validations are grounded on biomedical knowledge, approaches that describe certain criteria - such as non-overlapping data intervals of patients that experience different outcomes, immunologically interpretable data, and distinct graphic patterns - can inform, at personalized bases, earlier and/or with fewer observations.

Iron dysregulation in COVID-19 and reciprocal evolution of SARS-CoV-2: Natura nihil frustra facit

After more than a year of the COVID-19 pandemic, SARS-CoV-2 infection rates with newer variants continue to devastate much of the world. Global healthcare systems are overwhelmed with high positive patient numbers. Silent hypoxia accompanied by rapid deterioration and some cases with septic shock is responsible for COVID-19 mortality in many hospitalized patients. There is an urgent need to further understand the relationships and interplay with human host components during pathogenesis and immune evasion strategies. Currently, acquired immunity through vaccination or prior infection usually provides sufficient protection against the emerging variants of SARS-CoV-2 except Omicron variant requiring recent booster. New strains have shown higher viral loads and greater transmissibility with more severe disease presentations. Notably, COVID-19 has a peculiar prognosis in severe patients with iron dysregulation and hypoxia which is still poorly understood. Studies have shown abnormally low serum iron levels in severe infection but a high iron overload in lung fibrotic tissue. Data from our in-silico structural analysis of the spike protein sequence along with host proteolysis processing suggests that the viral spike protein fragment mimics Hepcidin and is resistant to the major human proteases. This functional spike-derived peptide dubbed "Covidin" thus may be intricately involved with host ferroportin binding and internalization leading to dysregulated host iron metabolism. Here, we propose the possible role of this potentially allogenic mimetic hormone corresponding to severe COVID-19 immunopathology and illustrate that this molecular mimicry is responsible for a major pathway associated with severe disease status. Furthermore, through 3D molecular modeling and docking followed by MD simulation validation, we have unraveled the likely role of Covidin in iron dysregulation in COVID-19 patients. Our meta-analysis suggests the Hepcidin mimetic mechanism is highly conserved among its host range as well as among all new variants to date including Omicron. Extensive analysis of current mutations revealed that new variants are becoming alarmingly more resistant to selective human proteases associated with host defense.

Multi-Cellular Immunological Interactions Associated With COVID-19 Infections

To rapidly prognosticate and generate hypotheses on pathogenesis, leukocyte multi-cellularity was evaluated in SARS-CoV-2 infected patients treated in India or the United States (152 individuals, 384 temporal observations). Within hospital (<90-day) death or discharge were retrospectively predicted based on the admission complete blood cell counts (CBC). Two methods were applied: (i) a "reductionist" one, which analyzes each cell type separately, and (ii) a "non-reductionist" method, which estimates multi-cellularity. The second approach uses a proprietary software package that detects distinct data patterns generated by complex and hypothetical indicators and reveals each data pattern's immunological content and associated outcome(s). In the Indian population, the analysis of isolated cell types did not separate survivors from non-survivors. In contrast, multi-cellular data patterns differentiated six groups of patients, including, in two groups, 95.5% of all survivors. Some data structures revealed one data point-wide line of observations, which informed at a personalized level and identified 97.8% of all non-survivors. Discovery was also fostered: some non-survivors were characterized by low monocyte/lymphocyte ratio levels. When both populations were analyzed with the non-reductionist method, they displayed results that suggested survivors and non-survivors differed immunologically as early as hospitalization day 1.

A novel compound active against SARS-CoV-2 targeting uridylate-specific endoribonuclease (NendoU/NSP15): in silico and in vitro investigations

NendoU (NSP15) is an Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond. Our in-house library was subjected to high throughput virtual screening (HTVS) to identify compounds with potential to inhibit NendoU enzyme, high-rank compounds (those that bound to multiple target structures) were further subjected to 100 nanoseconds MD simulations. Among these, one was found to be bound highly stable within the active site of the NendoU protein structure. Here, we are reporting a derivative of piperazine based '(2S,3S)-3-amino-1-(4-(4-(tert-butyl)benzyl)piperazin-1-yl)-4-phenylbutan-2-ol' (IV) from our in-house libraries having potential efficacy against SARS-CoV-2 in in vitro assays. This compound demonstrated inhibition of viral replication at the same level as Ivermectin, a known SARS-CoV-2 inhibitor, which is not used due to its toxicity at a higher than the currently approved dosage. Compound IV was not toxic to the cell lines up to a 50 μM concentration and exhibited IC_50s of 4.97 μM and 8.46 μM in viral entry and spread assay, respectively. Therefore, this novel class of NendoU inhibitor could provide new insights for the development of treatment options for COVID-19.

Antiviral evaluation of hydroxyethylamine analogs: Inhibitors of SARS-CoV-2 main protease (3CLpro), a virtual screening and simulation approach

The continued toll of COVID-19 has halted the smooth functioning of civilization on a global scale. With a limited understanding of all the essential components of viral machinery and the lack of structural information of this new virus, initial drug discovery efforts had limited success. The availability of high-resolution crystal structures of functionally essential SARS-CoV-2 proteins, including 3CLpro, supports the development of target-specific therapeutics. 3CLpro, the main protease responsible for the processing of viral polypeptide, plays a vital role in SARS-CoV-2 viral replication and translation and is an important target in other coronaviruses. Additionally, 3CLpro is the target of repurposed drugs, such as lopinavir and ritonavir. In this study, target proteins were retrieved from the protein data bank (PDB IDs: 6 M03, 6LU7, 2GZ7, 6 W63, 6SQS, 6YB7, and 6YVF) representing different open states of the main protease to accommodate macromolecular substrate. A hydroxyethylamine (HEA) library was constructed from harvested chemical structures from all the series being used in our laboratories for screening against malaria and Leishmania parasites. The database consisted of ∼1000 structure entries, of which 70% were new to ChemSpider at the time of screening. This in-house library was subjected to high throughput virtual screening (HTVS), followed by standard precision (SP) and then extra precision (XP) docking (Schrodinger LLC 2021). The ligand strain and complex energy of top hits were calculated by Molecular Mechanics Generalized Born Surface Area (MM/GBSA) method. Promising hit compounds (n = 40) specifically binding to 3CLpro with high energy and average MM/GBSA scores were then subjected to (100-ns) MD simulations. Using this sequential selection followed by an in-silico validation approach, we found a promising HEA-based compound (N,N'-((3S,3'S)-piperazine-1,4-diylbis(3-hydroxy-1-phenylbutane-4,2-diyl))bis(2-(5-methyl-1,3-dioxoisoindolin-2-yl)-3-phenylpropanamide)), which showed high in vitro antiviral activity against SARS-CoV-2. Further to reduce the size of the otherwise larger ligand, a pharmacophore-based predicted library of ∼42 derivatives was constructed, which were added to the previous compound library and rescreened virtually. Out of several hits from the predicted library, two compounds were synthesized, tested against SARS-CoV-2 culture, and found to have markedly improved antiviral activity.

Heparin: A simplistic repurposing to prevent SARS-CoV-2 transmission in light of its in-vitro nanomolar efficacy

The world is currently facing a novel coronavirus (SARS-CoV-2) pandemic. The greatest threat that is disrupting the normal functioning of society is the exceptionally high species independent transmission. Drug repurposing is understood to be the best strategy to immediately deploy well-characterized agents against new pathogens. Several repurposable drugs are already in evaluation for determining suitability to treat COVID-19. One such promising compound includes heparin, which is widely used in reducing thrombotic events associated with COVID-19 induced pathology. As part of identifying target-specific antiviral compounds among FDA and world-approved libraries using high-throughput virtual screening (HTVS), we previously evaluated top hits for anti-SARS-CoV-2 activity. Here, we report results of highly efficacious viral entry blocking properties of heparin (IC50 = 12.3 nM) in the complete virus assay, and further, propose ways to use it as a potential transmission blocker. Exploring further, our in-silico analysis indicated that the heparin interacts with post-translational glycoconjugates present on spike proteins. The patterns of accessible spike-glycoconjugates in open and closed states are completely contrasted by one another. Heparin-binding to the open conformation of spike structurally supports the state and may aid ACE2 binding as reported with cell surface-bound heparan sulfate. We also studied spike protein mutant variants' heparin interactions for possible resistance. Based on available data and optimal absorption properties by the skin, heparin could potentially be used to block SARS-CoV-2 transmission. Studies should be designed to exploit its nanomolar antiviral activity to formulate heparin as topical or inhalation-based formulations, particularly on exposed areas and sites of primary viremia e.g. ACE2 rich epithelia of the eye (conjunctiva/lids), nasal cavity, and mouth.

Mycobacterium lepromatosis MLPM_5000 is a potential heme chaperone protein HemW and mis-annotation of its orthologues in mycobacteria

The genome of a newly identified leprosy causing bacillus Mycobacterium lepromatosis was sequenced in 2015 wherein a gene MLPM_5000 was detected whose corresponding sequences are missing in its close relative Mycobacterium leprae, the well-known causal agent of leprosy. Thus MLPM_5000 is considered to be a specific genomic locus for differentiating M. lepromatosis from M. leprae. The locus was annotated as HemN (Coproporphyrinogen III oxidase) based on the available annotations in other mycobacterial species. However, we noticed that the MLPM_5000 and its orthologues in different mycobacterial species show a much higher degree of similarity with Escherichia coli HemW (378 aa) in comparison to the E. coli HemN (457 aa). Additionally, the fourth cysteine of the characteristic CX3CX2CXC motif of the E. coli HemN is replaced by a phenylalanine in the M. lepromatosis MLPM_5000 and its mycobacterial orthologues, which is a hallmark of heme chaperone protein HemW in E. coli and other species. Phylogenetic analysis of MLPM_5000 and its mycobacterial orthologues also showed that these proteins form a divergent phylogenetic clade with the HemW proteins of other species such as Escherichia coli and Lactococcus lactis. Further, Molecular Dynamics simulation studies also predicted that the residues of conserved HNXXYW motif of the MLPM_5000 may have a role in binding to heme part of the host hemoglobin, thereby suggesting it to be a HemW instead of HemN. Altogether, this work shows that MLPM_5000 and its mycobacterial orthologues are highly unlikely to be HemN. Therefore, the current annotations of mycobacterial HemN sequences should be corrected to heme chaperone 'HemW' in various protein databases. The study not only corrects the mis-annotation but also provides a new perspective in the context of evolutionary history of M. leprae and M. lepromatosis such as lack of HemW in M. leprae may explain some of the variations in the virulence between the two pathogens.

The emerging paradigm of calcium homeostasis as a new therapeutic target for protozoan parasites

Calcium channels (CCs), a group of ubiquitously expressed membrane proteins, are involved in many pathophysiological processes of protozoan parasites. Our understanding of CCs in cell signaling, organelle function, cellular homeostasis, and cell cycle control has led to improved insights into their structure and functions. In this article, we discuss CCs characteristics of five major protozoan parasites Plasmodium, Leishmania, Toxoplasma, Trypanosoma, and Cryptosporidium. We provide a comprehensive review of current antiparasitic drugs and the potential of using CCs as new therapeutic targets. Interestingly, previous studies have demonstrated that human CC modulators can kill or sensitize parasites to antiparasitic drugs. Still, none of the parasite CCs, pumps, or transporters has been validated as drug targets. Information for this review draws from extensive data mining of genome sequences, chemical library screenings, and drug design studies. Parasitic resistance to currently approved therapeutics is a serious and emerging threat to both disease control and management efforts. In this article, we suggest that the disruption of calcium homeostasis may be an effective approach to develop new anti-parasite drug candidates and reduce parasite resistance.

A Compressed Sensing Approach to Pooled RT-PCR Testing for COVID-19 Detection

We propose 'Tapestry', a single-round pooled testing method with application to COVID-19 testing using quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR) that can result in shorter testing time and conservation of reagents and testing kits, at clinically acceptable false positive or false negative rates. Tapestry combines ideas from compressed sensing and combinatorial group testing to create a new kind of algorithm that is very effective in deconvoluting pooled tests. Unlike Boolean group testing algorithms, the input is a quantitative readout from each test and the output is a list of viral loads for each sample relative to the pool with the highest viral load. For guaranteed recovery of [Formula: see text] infected samples out of [Formula: see text] being tested, Tapestry needs only [Formula: see text] tests with high probability, using random binary pooling matrices. However, we propose deterministic binary pooling matrices based on combinatorial design ideas of Kirkman Triple Systems, which balance between good reconstruction properties and matrix sparsity for ease of pooling while requiring fewer tests in practice. This enables large savings using Tapestry at low prevalence rates while maintaining viability at prevalence rates as high as 9.5%. Empirically we find that single-round Tapestry pooling improves over two-round Dorfman pooling by almost a factor of 2 in the number of tests required. We evaluate Tapestry in simulations with synthetic data obtained using a novel noise model for RT-PCR, and validate it in wet lab experiments with oligomers in quantitative RT-PCR assays. Lastly, we describe use-case scenarios for deployment.

Design of dental implant using design of experiment and topology optimization: A finite element analysis study

Ever since the introduction of topology optimization into the industrial and manufacturing fields, it has been a top priority to maximize the performance of any system by optimizing its geometrical parameters to save material while keeping its functionality unaltered. The purpose of this study is to design a dental implant macro-geometry by removing expendable material using topology optimization and to evaluate its biomechanical function. Three-dimensional finite element models were created of an implant embedded in cortical and cancellous bone. Parameters like the length and diameter of the implant and the bone quality (±20% variation in Young’s modulus, Poisson’s ratio and density for both cortical and cancellous bone) were varied to evaluate their effect on the principal stresses induced on the peri-implant bone tissues and the micromotion of the implant at 150 N applied load. Design optimization is used to select one suitable implant for each material property combination with optimum parameters that experiences the least von Mises stress and axial deformation, out of twenty implants with different length and diameter for each material property combination. Topology optimization was then used on the selected implants to remove the redundant material. The biomechanical functions of the implants with optimized parameter and volume were then evaluated. The finite element analyses estimated that a reduction of 32% to 45% in the implant volume is possible with the implant still retaining all of its functionality.

IL1B Increases Intestinal Tight Junction Permeability by Up-regulation of MIR200C-3p, Which Degrades Occludin mRNA

BACKGROUND & AIMS

Defects in the epithelial tight junction (TJ) barrier contribute to development of intestinal inflammation associated with diseases. Interleukin 1 beta (IL1B) increases intestinal permeability in mice. We investigated microRNAs that are regulated by IL1B and their effects on expression of TJ proteins and intestinal permeability.

METHODS

We used Targetscan to identify microRNAs that would bind the 3' untranslated region (3'UTR) of occludin mRNA; regions that interacted with microRNAs were predicted using the V-fold server and Assemble2, and 3-dimensional models were created using UCSF Chimera linked with Assemble2. Caco-2 cells were transfected with vectors that express microRNAs, analyzed by immunoblots and real-time polymerase chain reaction (PCR), and grown as monolayers; permeability in response to IL1B was assessed with the marker inulin. Male C57BL/6 mice were given intraperitoneal injections of IL1B and intestinal recycling perfusion was measured; some mice were given dextran sodium sulfate to induce colitis and/or gavage with an antagonist to MIR200C-3p (antagomiR-200C) or the nonspecific antagomiR (control). Intestinal tissues were collected from mice and analyzed by histology and real-time PCR; enterocytes were isolated by laser capture microdissection. We also analyzed colon tissues and organoids from patients with and without ulcerative colitis.

RESULTS

Incubation of Caco-2 monolayers with IL1B increased TJ permeability and reduced levels of occludin protein and mRNA without affecting the expression of other transmembrane TJ proteins. Targetscan identified MIR122, MIR200B-3p, and MIR200C-3p, as miRNAs that might bind to the occludin 3'UTR. MIR200C-3p was rapidly increased in Caco-2 cells incubated with IL1B; the antagomiR-200c prevented the IL1B-induced decrease in occludin mRNA and protein and reduced TJ permeability. Administration of IL1B to mice increased small intestinal TJ permeability, compared with mice given vehicle; enterocytes isolated from mice given IL1B had increased expression of MIR200C-3p and decreased levels of occludin messenger RNA (mRNA) and protein. Intestinal tissues from mice with colitis had increased levels of IL1B mRNA and MIR200C-3p and decreased levels of occludin mRNA; gavage of mice with antagomiR-200C reduced levels of MIR200C-3p and prevented the decrease in occludin mRNA and the increase in colonic permeability. Colon tissues and organoids from patients with ulcerative colitis had increased levels of IL1B mRNA and MIR200C-3p compared with healthy controls. Using 3-dimensional molecular modeling and mutational analyses, we identified the nucleotide bases in the occluding mRNA 3'UTR that interact with MIR200C-3p.

CONCLUSIONS

Intestine tissues from patients with ulcerative colitis and mice with colitis have increased levels of IL1B mRNA and MIR200C-3p, which reduces expression of occludin by enterocytes and thereby increases TJ permeability. Three-dimensional modeling of the interaction between MIR200C-3p and the occludin mRNA 3'UTR identified sites of interaction. The antagomiR-200C prevents the decrease in occludin in enterocytes and intestine tissues of mice with colitis, maintaining the TJ barrier.

A Review of the Preclinical and Clinical Efficacy of Remdesivir, Hydroxychloroquine, and Lopinavir-Ritonavir Treatments against COVID-19

In December of 2019, an outbreak of a novel coronavirus flared in Wuhan, the capital city of the Hubei Province, China. The pathogen has been identified as a novel enveloped RNA beta-coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus SARS-CoV-2 is associated with a disease characterized by severe atypical pneumonia known as coronavirus 2019 (COVID-19). Typical symptoms of this disease include cough, fever, malaise, shortness of breath, gastrointestinal symptoms, anosmia, and, in severe cases, pneumonia.¹ The high-risk group of COVID-19 patients includes people over the age of 60 years as well as people with existing cardiovascular disease and/or diabetes mellitus. Epidemiological investigations have suggested that the outbreak was associated with a live animal market in Wuhan. Within the first few months of the outbreak, cases were growing exponentially all over the world. The unabated spread of this deadly and highly infectious virus is a health emergency for all nations in the world and has led to the World Health Organization (WHO) declaring a pandemic on March 11, 2020. In this report, we consolidate and review the available clinically and preclinically relevant results emanating from in vitro animal models and clinical studies of drugs approved for emergency use as a treatment for COVID-19, including remdesivir, hydroxychloroquine, and lopinavir-ritonavir combinations. These compounds have been frequently touted as top candidates to treat COVID-19, but recent clinical reports suggest mixed outcomes on their efficacies within the current clinical protocol frameworks.

Effect of the core thickness on the flexural behaviour of polymer foam sandwich structures

In this study, the effect of the core thickness of the sandwich composite on its flexural strength was investigated. E-glass fibre reinforced epoxy-based laminates were used as the skin materials whereas a polyurethane foam was used as the core material with varying thickness of 5, 7, and 9 mm. The experimental/theoretical and FEA analysis were carried out. Results indicated that as core thickness increased, the axial face stresses/core shear stresses and total deformation decreased. This improved the composite structural properties. This improvement was accompanied by a minor increase in weight. A good concurrence was observed between theoretical and FEA results. These results allow us to compare and select optimum parameters for aerospace applications.

Excavating SARS-coronavirus 2 genome for epitope-based subunit vaccine synthesis using immunoinformatics approach

Since the outbreak of severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) in December 2019 in China, there has been an upsurge in the number of deaths and infected individuals throughout the world, thereby leading to the World Health Organization declaration of a pandemic. Since no specific therapy is currently available for the same, the present study was aimed to explore the SARS‐CoV‐2 genome for the identification of immunogenic regions using immunoinformatics approach. A series of computational tools were applied in a systematic way to identify the epitopes that could be utilized in vaccine development. The screened‐out epitopes were passed through several immune filters, such as promiscuousity, conservancy, antigenicity, nonallergenicity, population coverage, nonhomologous to human proteins, and affinity with human leukocyte antigen alleles, to screen out the best possible ones. Further, a construct comprising 11 CD4, 12 CD8, 3 B cell, and 3 interferon‐γ epitopes, along with an adjuvant β‐defensin, was designed in silico, resulting in the formation of a multiepitope vaccine. The in silico immune simulation and population coverage analysis of the vaccine sequence showed its capacity to elicit cellular, humoral, and innate immune cells and to cover up a worldwide population of more than 97%. Further, the interaction analysis of the vaccine construct with Toll‐like receptor 3 (immune receptor) was carried out by docking and dynamics simulations, revealing high affinity, constancy, and pliability between the two. The overall findings suggest that the vaccine may be highly effective, and is therefore required to be tested in the lab settings to evaluate its efficacy.

High burden of cardiometabolic risk factors in spouses of Indian women with hyperglycaemia in pregnancy

AIM

To evaluate the burden and association of cardiometabolic risk factors in the spouses of women with and without hyperglycaemia in pregnancy.

METHODS

Women with (n = 204) and without (n = 197) hyperglycaemia in pregnancy, along with their spouses, participated in this cross-sectional study. The hyperglycaemia in pregnancy group included women with gestational diabetes and diabetes in pregnancy. A detailed questionnaire was completed for all participants (men and women), documenting relevant personal and medical history, along with biochemical investigations (men).

RESULTS

A total of 401 couples were evaluated at the time point during the pregnancy of 24.7 ± 5.2 gestational weeks (mean ± sd). Dysglycaemia (prediabetes or diabetes), overweight/obesity (BMI ≥25 kg/m² ) and metabolic syndrome were detected in 120 (58.9%), 123 (60.3%) and 98 spouses (48.3%) of women with hyperglycaemia in pregnancy, respectively. In the fully adjusted model, an increased risk of dysglycaemia [odds ratio 1.43 (95% CI 0.95-2.17); P = 0.088], overweight/obesity [odds ratio 1.49 (95% CI 0.98-2.27); P = 0.064] and metabolic syndrome [odds ratio 2.00 (95% CI 1.30-3.07); P = 0.001] was seen in the spouses of women with hyperglycaemia in pregnancy. The prevalence of these metabolic conditions was higher in spouses of women with diabetes in pregnancy compared to spouses of women with gestational diabetes mellitus.

CONCLUSIONS

A high burden of cardiometabolic risk factors was observed in the spouses of women with hyperglycaemia in pregnancy. The opportunity provided by pregnancy could be used by the healthcare system not only to improve the health of the woman and her offspring, but also her spouse.

Multistage antiplasmodial activity of hydroxyethylamine compounds, in vitro and in vivo evaluations

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species. New therapeutics acting against the pathogenic asexual and sexual stages, including liver-stage malarial infection, have now attained more attention in achieving malaria eradication efforts. In this paper, two previously identified potent antiplasmodial hydroxyethylamine (HEA) compounds were investigated for their activity against the malaria parasite's multiple life stages. The compounds exhibited notable activity against the artemisinin-resistant strain of P. falciparum blood-stage culture with 50% inhibitory concentrations (IC₅₀) in the low micromolar range. The compounds' cytotoxicity on HEK293, HepG2 and Huh-7 cells exhibited selective killing activity with IC₅₀ values > 170 μM. The in vivo efficacy was studied in mice infected with P. berghei NK65, which showed a significant reduction in the blood parasite load. Notably, the compounds were active against liver-stage infection, mainly compound 1 with an IC₅₀ value of 1.89 μM. Mice infected with P. berghei sporozoites treated with compound 1 at 50 mg kg⁻¹ dose had markedly reduced liver stage infection. Moreover, both compounds prevented ookinete maturation and affected the developmental progression of gametocytes. Further, systematic in silico studies suggested both the compounds have a high affinity towards plasmepsin II with favorable pharmacological properties. Overall, the findings demonstrated that HEA and piperidine possessing compounds have immense potential in treating malarial infection by acting as multistage inhibitors.

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species.

Molecular Insights into Severe Acute Respiratory Syndrome Coronavirus 2 Pathobiology: Dissecting the Interplay between Cellular Innate Immunity and Immune Evasion

In December 2019, outbreak of a novel coronavirus flared in Wuhan, the capital city of Hubei province, China. The identified pathogen was an enveloped RNA betacoronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The outbreak was declared a pandemic by the World Health Organization (WHO), because the continual spread of this deadly and highly infectious virus is a health emergency for all world nations. SARS-CoV-2 is associated with severe atypical pneumonia coronavirus disease-19. Typical symptoms of this disease include fever, malaise, cough, shortness of breath, and in severe cases, death. As the virus continues to invade host cells deep into alveoli, infection severity mostly depends on the undeterred immune response that is triggered by elevated levels of inflammation-inducing cytokines, called a cytokine storm. In this article, we provide a comprehensive review of the viral life cycle and immunological responses associated with the SARS-CoV-2 infection.

Upgraded Giant Metrewave Radio Telescope timing of NGC 1851A: a possible millisecond pulsar - neutron star system

In this work, we present the results of 1 yr of upgraded Giant Metrewave Radio Telescope timing measurements of PSR J0514-4002A, a 4.99-ms pulsar in a 18.8-d eccentric ([Formula: see text]) orbit with a massive companion located in the globular cluster NGC 1851. Combining these data with earlier Green Bank Telescope data, we greatly improve the precision of the rate of advance of periastron, [Formula: see text] which, assuming the validity of general relativity, results in a much refined measurement of the total mass of the binary, [Formula: see text]. Additionally, we measure the Einstein delay parameter, γ, something that has never been done for any binary system with an orbital period larger than [Formula: see text]10 h. The measured value, [Formula: see text], is by far the largest for any binary pulsar. Furthermore, we measure the proper motion of the system ([Formula: see text] and [Formula: see text]), which is not only important for analysing its motion in the cluster, but is also essential for a proper interpretation of γ, given the latter parameter's correlation with the variation of the projected semimajor axis. The measurements of γ and the proper motion enable a separation of the system component masses: we obtain a pulsar mass of [Formula: see text] and a companion mass of [Formula: see text]. This raises the possibility that the companion is also a neutron star. Searches for radio pulsations from the companion have thus far been unsuccessful; hence, we cannot confirm the latter hypothesis. The low mass of this millisecond pulsar - one of the lowest ever measured for such objects - clearly indicates that the recycling process can be achieved with a relatively small amount of mass transfer.

MicroRNA in Pancreatic Cancer: From Biology to Therapeutic Potential

Pancreatic cancer is one of the most aggressive malignancies, accounting for more than 45,750 deaths annually in the U.S. alone. The aggressive nature and late diagnosis of pancreatic cancer, coupled with the limitations of existing chemotherapy, present the pressing need for the development of novel therapeutic strategies. Recent reports have demonstrated a critical role of microRNAs (miRNAs) in the initiation, progression, and metastasis of cancer. Furthermore, aberrant expressions of miRNAs have often been associated with the cause and consequence of pancreatic cancer, emphasizing the possible use of miRNAs in the effective management of pancreatic cancer patients. In this review, we provide a brief overview of miRNA biogenesis and its role in fundamental cellular process and miRNA studies in pancreatic cancer patients and animal models. Subsequent sections narrate the role of miRNA in, (i) cell cycle and proliferation; (ii) apoptosis; (iii) invasions and metastasis; and (iv) various cellular signaling pathways. We also describe the role of miRNA's in pancreatic cancer; (i) diagnosis; (ii) prognosis and (iii) therapeutic intervention. Conclusion section describes the gist of review with future directions.

A lifestyle intervention programme for the prevention of Type 2 diabetes mellitus among South Asian women with gestational diabetes mellitus [LIVING study]: protocol for a randomized trial

AIM

This study aims to determine whether a resource- and culturally appropriate lifestyle intervention programme in South Asian countries, provided to women with gestational diabetes (GDM) after childbirth, will reduce the incidence of worsening of glycaemic status in a manner that is affordable, acceptable and scalable.

METHODS

Women with GDM (diagnosed by oral glucose tolerance test using the International Association of the Diabetes and Pregnancy Study Groups criteria) will be recruited from 16 hospitals in India, Sri Lanka and Bangladesh. Participants will undergo a repeat oral glucose tolerance test at 6 ± 3 months postpartum and those without Type 2 diabetes, a total sample size of 1414, will be randomly allocated to the intervention or usual care. The intervention will consist of four group sessions, 84 SMS or voice messages and review phone calls over the first year. Participants requiring intensification of the intervention will receive two additional individual sessions over the latter half of the first year. Median follow-up will be 2 years. The primary outcome is the proportion of women with a change in glycaemic category, using the American Diabetes Association criteria: (i) normal glucose tolerance to impaired fasting glucose, or impaired glucose tolerance, or Type 2 diabetes; or (ii) impaired fasting glucose or impaired glucose tolerance to Type 2 diabetes. Process evaluation will explore barriers and facilitators of implementation of the intervention in each local context, while trial-based and modelled economic evaluations will assess cost-effectiveness.

DISCUSSION

The study will generate important new evidence about a potential strategy to address the long-term sequelae of GDM, a major and growing problem among women in South Asia. (Clinical Trials Registry of India No: CTRI/2017/06/008744; Sri Lanka Clinical Trials Registry No: SLCTR/2017/001; and ClinicalTrials.gov Identifier No: NCT03305939).

Breaking barriers in deployment of renewable energy

Several economic, institutional, technical and socio-cultural barriers hinder countries from moving from the high to the low emission pathway. The objective of this research is to find out the impacts of social, economic, technological and regulatory barriers in the deployment of renewable energy. Data were collected through an online questionnaire responded to by 223 professionals working in the energy sector all over the globe. This research shows that social, technological and regulatory barriers have a strong influence on the deployment of renewable energy, while economic barriers significantly influence it indirectly. By breaking research and development-related barriers, organizations will be able to invest greatly in developing advanced technologies that can optimize usage of renewable energy and make renewable energy appear more lucrative. With less polluting and lower tariff energy solutions being made available to local people, and higher profits for manufacturers, this will create an atmosphere where all stakeholders are satisfied.

Similar glycaemic control with less nocturnal hypoglycaemia in a 38-week trial comparing the IDegAsp co-formulation with insulin glargine U100 and insulin aspart in basal insulin-treated subjects with type 2 diabetes mellitus

AIMS

To confirm non-inferiority of insulin degludec/insulin aspart (IDegAsp) once-daily (OD) versus insulin glargine (IGlar) U100 OD + insulin aspart (IAsp) OD for HbA_1c after 26 weeks, and compare efficacy and safety between groups at W26 + W38.

METHODS

A 38-week, randomised, open-label, treat-to-target (HbA_1c < 7.0%) trial in adults with type 2 diabetes mellitus (on basal insulin ± oral antidiabetic drugs; HbA_1c 7.0-10.0%). Randomisation (1:1): IDegAsp or IGlar U100 + IAsp. Intensification to IDegAsp twice daily (BID) was permitted at W26 + W32, or with additional IAsp injections at W26 (maximum IAsp BID) or W32 (maximum IAsp three-times daily).

RESULTS

For W0-W26, mean percentage-change (standard deviation) HbA_1c was: IDegAsp, -1.1 (0.9); IGlar U100 + IAsp, -1.1 (0.8); estimated treatment difference: 0.07% (95% confidence interval [CI]: -0.06; 0.21) confirmed non-inferiority. At W26 and W38, target HbA_1c achievement, and mean fasting and postprandial glucose were similar across groups. At W38, more subjects achieved target HbA_1c without hypoglycaemia with IDegAsp (22.5%) than with IGlar U100 + IAsp (21.1%), with significantly fewer nocturnal episodes (W0-W38, estimated rate ratio: 0.61 [95% CI: 0.40; 0.93]). Safety profiles were similar across treatment groups throughout.

CONCLUSIONS

IDegAsp OD/BID are effective treatment intensification options versus multiple injection basal-bolus therapies, achieving similar glycaemic control, with significantly less nocturnal hypoglycaemia.

Structural modeling identifies Plasmodium vivax 4-diphosphocytidyl-2C-methyl-d-erythritol kinase (IspE) as a plausible new antimalarial drug target

Malaria parasites utilize Methylerythritol phosphate (MEP) pathway for synthesis of isoprenoid precursors which are essential for maturation and survival of parasites during erythrocytic and gametocytic stages. The absence of MEP pathway in the human host establishes MEP pathway enzymes as a repertoire of essential drug targets. The fourth enzyme, 4-diphosphocytidyl-2C-methyl-d-erythritol kinase (IspE) has been proved essential in pathogenic bacteria, however; it has not yet been studied in any Plasmodium species. This study was undertaken to investigate genetic polymorphism and concomitant structural implications of the Plasmodium vivax IspE (PvIspE) by employing sequencing, modeling and bioinformatics approach. We report that PvIspE gene displayed six non-synonymous mutations which were restricted to non-conserved regions within the gene from seven topographically distinct malaria-endemic regions of India. Phylogenetic studies reflected that PvIspE occupies unique status within Plasmodia genus and reflects that Plasmodium vivax IspE gene has a distant and non-conserved relation with human ortholog Mevalonate Kinase (MAVK). Structural modeling analysis revealed that all PvIspE Indian isolates have critically conserved canonical galacto-homoserine-mevalonate-phosphomevalonate kinase (GHMP) domain within the active site lying in a deep cleft sandwiched between ATP and CDPME-binding domains. The active core region was highly conserved among all clinical isolates, may be due to >60% β-pleated rigid architecture. The mapped structural analysis revealed the critically conserved active site of PvIspE, both sequence, and spacially among all Indian isolates; showing no significant changes in the active site. Our study strengthens the candidature of Plasmodium vivax IspE enzyme as a future target for novel antimalarials.

Calcium Dependent Protein Kinases (CDPKs): Key to Malaria Eradication

INTRODUCTION

The family of calcium-dependent protein kinases (CDPKs) carries a kinase domain fused to a calmodulin-like domain. The presence of protein kinases devoid of clear mammalian eukaryotic protein kinase orthologues makes them potential targets for therapeutic development. Recent studies on CDPKs have inspired an important primary regulator of calcium (intracellular Ca2+ signaling), which is extensively reported to play a critical role in various stages of the apicomplexan life cycle such as microneme secretion of adhesions, cell invasion, gamete maturation, gliding motility and egress of Plasmodium Spp.

CONCLUSION

Understanding and identifying these essential cytoregulatory components of the parasite is important for drug targets development and therapeutic intervention.

Role of nebivolol in the control and management of central aortic blood pressure in hypertensive patients

Measurement of blood pressure (BP) using a brachial cuff sphygmomanometer is universally accepted for the diagnosis of hypertension and prediction of cardiovascular diseases. However, brachial systolic BP does not represent actual systolic BP in the central arteries which encounter cardiac load directly. Due to wave amplification from central to peripheral arteries, a significant difference exists between the two. Central BP measurements also account for arterial stiffness, vessel branching and vascular mechanics, unlike brachial BP. Emerging data suggests that hypertension can be diagnosed more accurately by central pressure indices as compared to brachial BP. Various non-invasive techniques are now available to measure central BP indices owing to recent technological advances. Recently, it has been reported that different classes of anti-hypertensive drugs display differential effects on brachial and central BPs. Nebivolol is a cardio-selective beta-blocker which targets central systolic BP and reduces it significantly along with brachial BP. In this article, we will review the current literature to evaluate the role of central BP to diagnose hypertension in detail. We will also assess the clinical evidence to evaluate the role of nebivolol in the management of elevated central systolic BP. Central BP indices offer better estimation of BP in central arteries and should be considered in routine clinical practice. Nebivolol has shown significant reduction in aortic pressure and wave reflection and improvements in endothelial dysfunction and arterial stiffness in hypertensive patients.