Medicinal chemistry aspects of uracil containing dUTPase inhibitors targeting colorectal cancer

Deoxyuridine-5'-triphosphate nucleotidohydrolase (dUTPase), a vital enzyme in pyrimidine metabolism, is a prime target for treating colorectal cancer. Uracil shares structural traits with DNA/RNA bases, prompting exploration by medicinal chemists for pharmacological modifications. Some existing drugs, including thymidylate synthase (TS) and dUTPase inhibitors, incorporate uracil moieties. These derivatives hinder crucial cell proliferation pathways encompassing TS, dUTPases, dihydropyrimidine dehydrogenase, and uracil-DNA glycosylase. This review compiles uracil derivatives that have served as dUTPase inhibitors across various organisms, forming a library for targeting human dUTPase. Insights into their structural requisites for human applications and comparative analyses of binding pockets are provided for analyzing the compounds against human dUTPase.

Identification of Aztreonam as a potential antibacterial agent against Pasteurella multocida sialic acid binding protein: A combined in silico and in-vitro analysis

Pasteurella multocida, a Gram-negative zoonotic bacterial pathogen, interacts with the host environment, immune response, and infection through outer membrane proteins, adhesins, and sialic acid binding proteins. Sialic acids provide nutrition and mask bacterial identity, hindering the complement system, facilitates tissue access and biofilm formation. Sialic acid binding protein (SAB) enable adhesion to host cells, immune evasion, and nutrient acquisition, making them potential targets for preventing Pasteurella multocida infections. In this study, in silico molecular docking assessed 11 antibiotics targeting SAB (4MMP) comparing their docking scores to Amoxicillin. As SAB (4MMP) exhibits a highly conserved sequence in various Pasteurella multocida strains, including the specific strain PMR212 studied in this article, with a 96.09% similarity score. Aztreonam and Gentamicin displayed the highest docking scores (-6.025 and -5.718), followed by a 100ns molecular dynamics simulation. Aztreonam exhibited stable simulation with protein RMSD fluctuations of 1.8-2.2 Å. The ligand initially had an RMSD of 1.6 Å, stabilizing at 4.8 Å. Antibiotic sensitivity testing confirmed Aztreonam's efficacy with the largest inhibition zone of 42 mm, while Amoxicillin and Gentamicin had inhibition zones of 32 mm and 25 mm, respectively. According to CLSI guidelines, all three antibiotics were effective against Pasteurella multocida. Aztreonam's superior efficacy positions it as a promising candidate for further investigation in targeting Pasteurella multocida.

Preoperative Versus Perioperative Risk Factors for Delayed Pain and Opioid Cessation After Total Joint Arthroplasty: A Prospective Cohort Study

INTRODUCTION

The evolution of pre- versus postoperative risk factors remains unknown in the development of persistent postoperative pain and opioid use. We identified preoperative versus comprehensive perioperative models of delayed pain and opioid cessation after total joint arthroplasty including time-varying postoperative changes in emotional distress. We hypothesized that time-varying longitudinal measures of postoperative psychological distress, as well as pre- and postoperative use of opioids would be the most significant risk factors for both outcomes.

METHODS

A prospective cohort of 188 patients undergoing total hip or knee arthroplasty at Stanford Hospital completed baseline pain, opioid use, and emotional distress assessments. After surgery, a modified Brief Pain Inventory was assessed daily for 3 months, weekly thereafter up to 6 months, and monthly thereafter up to 1 year. Emotional distress and pain catastrophizing were assessed weekly to 6 months, then monthly thereafter. Stepwise multivariate time-varying Cox regression modeled preoperative variables alone, followed by all perioperative variables (before and after surgery) with time to postoperative opioid and pain cessation.

RESULTS

The median time to opioid and pain cessation was 54 and 152 days, respectively. Preoperative total daily oral morphine equivalent use (hazard ratio-HR 0.97; 95% confidence interval-CI 0.96-0.98) was significantly associated with delayed postoperative opioid cessation in the perioperative model. In contrast, time-varying postoperative factors: elevated PROMIS (Patient-Reported Outcomes Measurement Information System) depression scores (HR 0.92; 95% CI 0.87-0.98), and higher Pain Catastrophizing Scale scores (HR 0.85; 95% CI 0.75-0.97) were independently associated with delayed postoperative pain resolution in the perioperative model.

CONCLUSIONS

These findings highlight preoperative opioid use as a key determinant of delayed postoperative opioid cessation, while postoperative elevations in depressive symptoms and pain catastrophizing are associated with persistent pain after total joint arthroplasty providing the rationale for continued risk stratification before and after surgery to identify patients at highest risk for these distinct outcomes. Interventions targeting these perioperative risk factors may prevent prolonged postoperative pain and opioid use.

In Silico Studies of Indole Derivatives as Antibacterial Agents

Objectives

Molecular docking and QSAR studies of indole derivatives as antibacterial agents.

Methods

In this study, we used a multiple linear regressions (MLR) approach to construct a 2D quantitative structure activity relationship of 14 reported indole derivatives. It was performed on the reported antibacterial activity data of 14 compounds based on theoretical chemical descriptors to construct statistical models that link structural properties of indole derivatives to antibacterial activity. We have also performed molecular docking studies of same compounds by using Maestro module of Schrodinger. A set the molecular descriptors like hydrophobic, geometric, electronic and topological characters were calculated to represent the structural features of compounds. The conventional antibiotics sultamicillin and ampicillin were not used in the model development since their structures are different from those of the created compounds. Biological activity data was first translated into pMIC values (i.e. -log MIC) and used as a dependent variable in QSAR investigation.

Results

Compounds with high electronic energy and dipole moment were effective antibacterial agents against S. aureus, indole derivatives with lower κ₂ values were excellent antibacterial agents against MRSA standard strain, and compounds with lower R value and a high ²χ^v value were effective antibacterial agents against MRSA isolate.

Conclusion

Compounds 12 and 2 showed better binding score against penicillin binding protein 2 and penicillin binding protein 2a respectively.

Elastic Net Regularization Paths for All Generalized Linear Models

The lasso and elastic net are popular regularized regression models for supervised learning. Friedman, Hastie, and Tibshirani (2010) introduced a computationally efficient algorithm for computing the elastic net regularization path for ordinary least squares regression, logistic regression and multinomial logistic regression, while Simon, Friedman, Hastie, and Tibshirani (2011) extended this work to Cox models for right-censored data. We further extend the reach of the elastic net-regularized regression to all generalized linear model families, Cox models with (start, stop] data and strata, and a simplified version of the relaxed lasso. We also discuss convenient utility functions for measuring the performance of these fitted models.

Impact of surgical left atrial appendage closure during coronary bypass on clinical outcomes and readmissions

Background

Whether surgical left atrial appendage closure (sLAAC) during coronary artery bypass (CABG)surgery improves post-operative outcome including stroke and atrial fibrillation (AF) occurrence is largely unknown.

Objective

To analyze the impact of concomitant sLAAC during CABG in terms of outcomes and readmissions over the following year.

Methods

We analyzed the Nationwide Readmissions Database (2016–2019) using ICD-10 codes to identify hospitalizations for CABG. Patients were subcategorized based on whether sLAAC was performed or not. Among patients who survived their index admission, we employed propensity matching (1:3) to adjust for age, sex, comorbidities, CHA2DS2-VASc scores, previous AF history, heart failure and hospital characteristics. Primary outcomes included unplanned AF and stroke-related readmissions at 1 year.

Results

A total of 58,311 patients with CABG and sLAAC were identified with 175,940 propensity matched controls. Patients undergoing sLAAC were older with higher CHA2DS2-VASc scores and comorbidity burdens. Confounders were well balanced following propensity matching. Over a mean follow-up of 152 days, sLAAC was associated with higher risk of readmission due to AF at one year (HR 1.71 [1.49–1.96] p<0.001). This association is independent of previous AF history. Lower rates of stroke-related readmission was associated with perfomance of sLAAC (HR 0.80 (0.65–0.97) p=0.026), however the association was not observed when accounting for AF history.

Conclusion

CABG with concomitant sLAAC is maybe associated with lower stroke risk at the cost of higher risk of AF readmissions.

Funding Acknowledgement

Type of funding sources: None.

Accuracy of Electronic Medical Record Follow-Up Data for Estimating the Survival Time of Patients With Cancer

PURPOSE

For real-world evidence, it is convenient to use routinely collected data from the electronic medical record (EMR) to measure survival outcomes. However, patients can become lost to follow-up, causing incomplete data and biased survival time estimates. We quantified this issue for patients with metastatic cancer seen in an academic health system by comparing survival estimates from EMR data only and from EMR data combined with high-quality cancer registry data.

MATERIALS AND METHODS

Patients diagnosed with metastatic cancer from 2008 to 2014 were included in this retrospective study. Patients who were diagnosed with cancer or received their initial treatment within our system were included in the institutional cancer registry and this study. Overall survival was calculated using the Kaplan-Meier method. Survival curves were generated in two ways: using EMR follow-up data alone and using EMR data supplemented with data from the Stanford Cancer Registry/California Cancer Registry.

RESULTS

Four thousand seventy-seven patients were included. The median follow-up using EMR + Cancer Registry data was 19.9 months, and the median follow-up in surviving patients was 67.6 months. There were 1,301 deaths recorded in the EMR and 3,140 deaths recorded in the Cancer Registry. The median overall survival from the date of cancer diagnosis using EMR data was 58.7 months (95% CI, 54.2 to 63.2); using EMR + Cancer Registry data, it was 20.8 months (95% CI, 19.6 to 22.3). A similar pattern was seen using the date of first systemic therapy or date of first hospital admission as the baseline date.

CONCLUSION

Using EMR data alone, survival time was overestimated compared with EMR + Cancer Registry data.

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks.

The changing impact of cytomegalovirus among hematopoietic cell transplant recipients during the past decade: A single institutional cohort study

BACKGROUND

With advancements in allogeneic hematopoietic cell transplantation (alloHCT), the need for cytomegalovirus (CMV) surveillance persists.

METHODS

We present a retrospective analysis on the impact of CMV with preemptive therapy in 1,065 alloHCT patients with donor and/or recipient CMV seropositivity from 2009-2019.

RESULTS

51% developed clinically significant CMV infection (CMV-CSI); 6.5% had CMV disease. In multivariate analysis stratified by serostatus and preparative regimen the use of ATG (HR 2.97, 95% CI 2.00 to 4.42, P < 0.001) was associated with development of CMV-CSI. Median length of stay for index hospitalization was longer in patients with CMV-CSI (27 d vs 25 d, respectively; P = .002), as were rates (32.9% vs 17.7%; P < .001) and duration (9 d vs 6 d; P < .001) of rehospitalization, and median total inpatient days (28 d vs 26 d; P < .001). Patients with CMV-CSI had higher rates of neutropenia (47% vs 20%; P < .001) and transfusion support (PRBC, median 5 vs 3; P < .001; platelets, median 3 vs 3; P < .001).

CONCLUSION

Preemptive therapy does not negate the impact of CMV-CSI on peri-engraftment toxicity and healthcare utilization. This cohort represents a large single center study on the impact of CMV in the pre-letermovir era and serves as a real-world comparator for assessing the impact of future prophylaxis. This article is protected by copyright. All rights reserved.

Penalized regression for left-truncated and right-censored survival data

High‐dimensional data are becoming increasingly common in the medical field as large volumes of patient information are collected and processed by high‐throughput screening, electronic health records, and comprehensive genomic testing. Statistical models that attempt to study the effects of many predictors on survival typically implement feature selection or penalized methods to mitigate the undesirable consequences of overfitting. In some cases survival data are also left‐truncated which can give rise to an immortal time bias, but penalized survival methods that adjust for left truncation are not commonly implemented. To address these challenges, we apply a penalized Cox proportional hazards model for left‐truncated and right‐censored survival data and assess implications of left truncation adjustment on bias and interpretation. We use simulation studies and a high‐dimensional, real‐world clinico‐genomic database to highlight the pitfalls of failing to account for left truncation in survival modeling.

Fast Numerical Optimization for Genome Sequencing Data in Population Biobanks

MOTIVATION

Large-scale and high-dimensional genome sequencing data poses computational challenges. General purpose optimization tools are usually not optimal in terms of computational and memory performance for genetic data.

RESULTS

We develop two efficient solvers for optimization problems arising from large-scale regularized regressions on millions of genetic variants sequenced from hundreds of thousands of individuals. These genetic variants are encoded by the values in the set {0, 1, 2, NA}. We take advantage of this fact and use two bits to represent each entry in a genetic matrix, which reduces memory requirement by a factor of 32 compared to a double precision floating point representation. Using this representation, we implemented an iteratively reweighted least square algorithm to solve Lasso regressions on genetic matrices, which we name snpnet-2.0. When the dataset contains many rare variants, the predictors can be encoded in a sparse matrix. We utilize the sparsity in the predictor matrix to further reduce memory requirement and computational speed. Our sparse genetic matrix implementation uses both the compact 2-bit representation and a simplified version of compressed sparse block format so that matrix-vector multiplications can be effectively parallelized on multiple CPU cores. To demonstrate the effectiveness of this representation, we implement an accelerated proximal gradient method to solve group Lasso on these sparse genetic matrices. This solver is named sparse-snpnet, and will also be included as part of snpnet R package. Our implementation is able to solve Lasso and group Lasso, linear, logistic and Cox regression problems on sparse genetic matrices that contain 1,000,000 variants and almost 100,000 individuals within 10 minutes and using less than 32GB of memory.

AVAILABILITY

https://github.com/rivas-lab/snpnet/tree/compact.

Design, Synthesis, SAR Study, Antimicrobial and Anticancer Evaluation of Novel 2-Mercaptobenzimidazole Azomethine Derivatives

BACKGROUND

Various analogues of benzimidazole are found to be biologically and therapeutically potent against several ailments. Benzimidazole when attached with heterocyclic rings has shown wide range of potential activities. So, from the above provided facts, we altered benzimidazole derivatives so that more potent antagonists could be developed. In the search for a new category of antimicrobial and anticancer agents, novel azomethine of 2-mercaptobenzimidazole derived from 3-(2- (1H-benzo[d]imidazol-2-ylthio)acetamido)benzohydrazide were synthesized.

RESULTS AND DISCUSSION

The synthesized analogues were characterized by FT-IR, ¹H/¹³C-NMR and MS studies as well C, H, N analysis. All synthesized compounds were evaluated for in vitro antibacterial activity against Gram-positive (B. subtilis), Gram-negative (E. coli, P. aeruginosa, K. pneumoniae and S. typhi) strains and in vitro antifungal activity against C. albicans and A. niger strains by serial dilution method, the minimum inhibitory concentration (MIC) described in μM/ml. The in vitro anticancer activity of synthesized compounds was determined against human colorectal carcinoma cell line (HCT- 116) using 5-fluorouracil as standard drug.

CONCLUSION

In general, most of the synthesized derivatives exhibited significant antimicrobial and anticancer activities. Compounds 8, 10, 15, 16, 17, 20 and 22 showed significant antimicrobial activity towards tested bacterial and fungal strains and compound 26 exhibited significant anticancer activity.

Synthesis and biological evaluation of heterocyclic 1,2,4-triazole scaffolds as promising pharmacological agents

Background

Triazole is an important heterocyclic moiety that occupies a unique position in heterocyclic chemistry, due to its large number of biological activities. It exists in two isomeric forms i.e. 1,2,4-triazole and 1,2,3-triazole and is used as core molecule for the design and synthesis of many medicinal compounds. 1,2,4-Triazole possess broad spectrum of therapeutically interesting drug candidates such as analgesic, antiseptic, antimicrobial, antioxidant, anti-urease, anti-inflammatory, diuretics, anticancer, anticonvulsant, antidiabetic and antimigraine agents.

Methods

The structures of all synthesized compounds were characterized by physicochemical properties and spectral means (IR and NMR). The synthesized compounds were evaluated for their in vitro antimicrobial activity against Gram-positive (B. subtilis), Gram-negative (P. aeruginosa and E. coli) bacterial and fungal (C. albicans and A. niger) strains by tube dilution method using ciprofloxacin, amoxicillin and fluconazole as standards. In-vitro antioxidant and anti-urease screening was done by DPPH assay and indophenol method, respectively. The in-vitro anticancer evaluation was carried out against MCF-7 and HCT116 cancer cell lines using 5-FU as standards.

Results, discussion and conclusion

The biological screening results reveal that the compounds T₅ (MIC_{BS, EC} = 24.7 µM, MIC_PA, _CA = 12.3 µM) and T₁₇ (MIC_AN = 27.1 µM) exhibited potent antimicrobial activity as comparable to standards ciprofloxacin, amoxicillin (MIC_Cipro = 18.1 µM, MIC_Amo = 17.1 µM) and fluconazole (MIC_Flu = 20.4 µM), respectively. The antioxidant evaluation showed that compounds T₂ (IC₅₀ = 34.83 µg/ml) and T₃ (IC₅₀ = 34.38 µg/ml) showed significant antioxidant activity and comparable to ascorbic acid (IC₅₀ = 35.44 µg/ml). Compounds T₃ (IC₅₀ = 54.01 µg/ml) was the most potent urease inhibitor amongst the synthesized compounds and compared to standard thiourea (IC₅₀ = 54.25 µg/ml). The most potent anticancer activity was shown by compounds T₂ (IC₅₀ = 3.84 μM) and T₇ (IC₅₀ = 3.25 μM) against HCT116 cell lines as compared to standard 5-FU (IC₅₀ = 25.36 μM).

Naphthoquinone derivatives exhibit apoptosis-like effect and anti-trypanosomal activity against Trypanosoma evansi

Trypanosoma evansi is an extracellular flagellate blood protozoan parasite and an etiological agent of animal trypanosomosis. Presently, only a few drugs are registered and have been used for the treatment of animal trypanosomosis, but they show severe toxic effects and also face the problem of drug resistance. Naphthoquinones (NTQ) are considered as fortunate structures in the field of medicinal chemistry as they have been reported for their antitrypanosomal potential against other trypanosomes-T. brucei and T. cruzi. In the present study, six naphthoquinones (NTQ1-NTQ6) derivatives were evaluated for anti-trypanosomal activity by demonstrating their growth inhibitory effect against T. evansi. All NTQs significantly (p < 0.001) exhibited activity against parasite growth and multiplication with IC₅₀ values of 11.48 μM, 373.6 μM, 12.97 μM, 21.97 μM, 18.19 μM and 5.758 μM but NTQ1, NTQ3 and NTQ6 were selected based on their IC₅₀ value for further studies. The dose-and time-dependent morphological effect on parasite was evaluated including the measurement of reactive oxygen species (ROS) by spectrofluorometery and measurement of apoptosis by flow cytometry. The selected NTQs exhibited a significant production of ROS and displayed a significant AV⁺ and PI⁺ labelled cells in the axenic culture of T. evansi than quinapyramine methyl sulphate (QPS), as reference control. NTQs also showed more cytotoxic effect on horse peripheral blood mononuclear cells as compare to QPS. Therefore, we confirmed the antitrypanosomal activity and apoptotic-like mechanism of NTQs in an axenic culture of T. evansi.

Defining the features and duration of antibody responses to SARS-CoV-2 infection associated with disease severity and outcome

SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, can neutralize the virus. It is, however, unknown which features of the serological response may affect clinical outcomes of COVID-19 patients. We analyzed 983 longitudinal plasma samples from 79 hospitalized COVID-19 patients and 175 SARS-CoV-2-infected outpatients and asymptomatic individuals. Within this cohort, 25 patients died of their illness. Higher ratios of IgG antibodies targeting S1 or RBD domains of spike compared to nucleocapsid antigen were seen in outpatients who had mild illness versus severely ill patients. Plasma antibody increases correlated with decreases in viral RNAemia, but antibody responses in acute illness were insufficient to predict inpatient outcomes. Pseudovirus neutralization assays and a scalable ELISA measuring antibodies blocking RBD-ACE2 interaction were well correlated with patient IgG titers to RBD. Outpatient and asymptomatic individuals' SARS-CoV-2 antibodies, including IgG, progressively decreased during observation up to five months post-infection.

Increasing use of ablation in the management of atrial fibrillation in heart failure: insights from a national database on 10 year trends in the United States

Background

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice, even more so among patients with heart failure (HF). Results of the recent CABANA and CASTLE-AF trials indicate significant improvements in ejection fraction, HF readmissions as well as overall mortality with the incorporation of rhythm control strategies in HF patients. These findings challenge existing notions of equivalency of rate vs rhythm control strategies. In this study, we analyzed the impact of this evidence on treatment practices and the short term outcomes of ablation in this patient cohort.

Methods

We conducted a retrospective study using the AHRQ-HCUP National Readmission Database for the years 2005–2014. ICD 9 diagnosis codes were used to identify all adult patients (≥18 years) undergoing AF ablation procedures as well as a sub-cohort of patients with existing HF. Trends in the use of ablation procedures, patient characteristics as well as details of short term procedural outcomes were studied. Multivariate regression analysis was utilized to adjust for confounders. Complications were defined as per the Agency for healthcare research and quality guidelines. Independent risk factors for in-hospital mortality were identified using proportional hazards model.

Results

Our results indicate a trend of rising rates of AF ablation procedures overall with a peak in 2011 at 20,046 and gradual downtrend thereafter (10,195 in 2005 to 11735 in 2014). Our data revealed a consistent rise in ablation procedures among heart failure patients during the same period (832 to 2245). A definite reduction in peri-procedural mortality is noted (0.24% in 2005 to 0.17% in 2014, p=0.2) – an improvement that is maximally apparent in the heart failure group (2.49% to 0.4%, p=0.07). Overall complication rates however are significantly increased overall with a proportional rise noted among HF patients.

Conclusions

Our data from a nationally representative registry indicates an increasing utilization of ablation as a therapeutic modality in the management of atrial fibrillation in HF. Future prospective studies are required to assess the positive impact of these changes in clinical practice as offset by their associated complications.

10 year AF ablation trends in HF

Funding Acknowledgement

Type of funding source: None

A genome-wide association study identifies novel genetic loci associated with pulmonary embolism

Background

Pulmonary embolism (PE) is a life-threatening cardiovascular condition. Studies showed that PE patients were associated with disorders of lipid metabolism and had higher triglyceride and lower HDL-C levels compared with healthy. We conducted the genome-wide association study to identify novel loci contributing to PE.

Methods

We conducted a large-scale GWAS of PE in 5,466 PE cases and 461,219 controls of European ancestry from the UK Biobank (466,685 participants total). We used genome-wide summary statistics to test for enrichment of functional annotations using ENRICHR. Example pathways included in Enrichr for testing include membership of genes in pathway databases such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Wikipathway, PANTHER, BioCarta or NCI-Nature pathways. We analyzed the pathways using combined score and p-values which were well validated by comparing to several methods. For pathway analyses, we considered a nominal P-value threshold of 0.05.

Results

We identified genome-wide significant genetic associations in 63 independent genetic loci for PE (P&lt;5.0x10–7). Our findings for top pathways highlight that lipid metabolism (LIPC, LCAT, NPC2), caffeine metabolism (NAT2), and sudden cardiac death (ABCG8) related genetic loci play an important role in PE alongside genes already associated with coagulation-thrombosis pathway (VWF, THPO, PTPN11, INPP5D, UROS, HMBS) (all p-values p-values &lt;0.05).

Conclusion

Our findings uncovered unexpected novel factors of PE etiology, suggesting novel mechanistic concepts of PE pathophysiology.

Funding Acknowledgement

Type of funding source: None

Impact of outflow tract obstruction in the management of atrial fibrillation in hypertrophic cardiomyopathy: insights from the national readmission database

Background

Atrial fibrillation (AF) is commonly encountered in patients with Hypertrophic Cardiomyopathy (HCM). Presence of AF in this high risk population is detrimental due to its effect on hemodynamics, diastolic function and potential induction of ventricular tachyarrhythmias. For these reasons a rhythm control strategy is highly desirable, and yet catheter ablation of AF is consistently inefficacious with poorer overall outcomes. We hypothesize that in HCM presence of outflow tract obstruction by virtue of its effect on left atrial hemodynamics, altered circulatory flow patterns in the pulmonary veins, and stretch related triggered activities would create an arrhythmogenic substrate, and have significant impact on the outcomes of catheter ablation of AF. In this study, we aimed to evaluate AF ablation outcomes based on the presence or absence of outflow tract obstructions in patients with HCM.

Methods

We conducted a retrospective study using the AHRQ-HCUP National Readmission Database for the years 2016–17. All adults (≥18 years) with HCM undergoing AF ablation procedures were identified using ICD-9 codes. The cohort was divided into two groups; Obstructive HCM (Group A) and Non-Obstructive HCM (Group B)

Multivariate regression analysis was utilized to adjust for confounders. Independent risk factors for in-hospital mortality were identified using a proportional hazards model. Complications were defined as per the Agency for Health Care Research and Quality guideline.

Results

From a total of 71,451,419 patients in the NRD registry, 97 patients with HCM were identified and formed the study cohort. When divided based on the presence or absence of outflow tract obstruction, there were 25 patients with Obstructive HCM and 72 patients with Non-obstructive HCM.

Both groups were similar in clinical characteristics including CHADVASc scores and Charlson Comobidity indices as outlined in Table 1. Procedural outcome analysis revealed higher 30-day cardiac readmissions in the Obstructive HCM group compared to Non-obstructive HCM (25.2% vs 7.97%, p=0.049). The Obstructive HCM group had higher rates of atrial arrhythmias, 57.97%, compared to 32.44% in the non-obstructive HCM group, and heart failure exacerbations, 41.27% vs 25.82%. However, both indices did not reach statistical significance. The procedural complications rates tended to be higher in the non-obstructive HCM group, 10.8% vs. 5.6% in the Obstructive HCM group (p=0.54).

Conclusions

Presence of an obstructive component to HCM is associated with significantly increased short term cardiac readmissions predominantly driven by recurrent atrial arrhythmias and heart failure. These findings suggest negative influence of altered cardiac hemodynamics related to outflow tract obstruction on atrial arrhythmias. The arrhythmogenic substrate of HCM may therefore be different and less amenable to catheter ablation.

HCM ablation outcomes

Funding Acknowledgement

Type of funding source: None

Gender differences in spontaneous coronary artery dissection: a nationwide analysis

Background

Spontaneous coronary artery dissection (SCAD) is a very rare cause of acute coronary syndromes in young otherwise healthy patients with a striking predilection for the female gender. Unfortunately, SCAD can result in significant morbidities and mortality. The pathological mechanism has not been fully clarified yet but hormonal changes might represent a sufficiently convincing explanation for some patients with SCAD. We hypothesized that gender difference in mortality in SCAD patients.

Methods

Data for this retrospective cohort study were extracted from the Nationwide Inpatient Sample for 2014 using the 9th revision of the International Classification of Diseases (ICD) 414.12 (spontaneous coronary artery dissection). Demographics, in-hospital mortality, conventional risk factors (diabetes, hypertension, hyperlipidemia, alcohol and tobacco abuse), acute critical illnesses like sepsis, septic shock, stroke, acute respiratory insufficiency, acute renal failure, and chronic conditions (anxiety, depression, malignancy and metastatic diseases) were studied. Univariate and multivariate logistic regression modeling were performed to determine predictors associated with the development of inpatient mortality in SCAD patients. All analyses were conducted using R 3.4.0 and STATA/MP 14.2. All p-values were two-sided, and statistical significance was determined at the level of p&lt;0.05.

Result

A total of 270 SCAD patients were identified. Of those SCAD patients, no fibromuscular dysplasia (FMD) or pregnancy were identified. Patients were predominantly women (71%) and the mean age was 53 years. Overall in-hospital mortality was 5.6%, with 6.6% in male and 5.3% in female. Ethnicity, gender, stroke, acute renal failure, anxiety and depression did not predict mortality, length of stay, annual income, total hospital charge (all p&gt;0.05). Multivariate analysis revealed no gender difference in SCAD patients and no independent predictors of mortality were identified.

Conclusions

This large nationwide study reveals that SCAD may be underdiagnosed but underutilization of work up such as FMD. SCAD is thought to be hormone related likely associated with female gender. Our results showed that no gender difference in mortality. Further large prospective studies are needed to determine gender difference in mortality and other predictors in mortality.

Funding Acknowledgement

Type of funding source: None

Impact of age on the obesity paradox in acute coronary syndrome: a nationwide analysis

Background

The obesity paradox – indicating improved short term mortality in obese individuals has been widely explored in a number of cardiovascular conditions. However, its validity in an elderly population and the possible physiological impact of aging on this phenomenon in Acute Coronary syndrome (ACS) remain unclear. In this study, we aim to determine the relationship between obesity and in-hospital mortality, morbidity, and health care resource utilization in this cohort of patients.

Methods

A retrospective study was conducted using the AHRQ-HCUP National Inpatient Sample for the year 2014. Elderly adults (≥65 years) with a principal diagnosis of ACS and a secondary diagnosis of obesity were identified using ICD-9 diagnosis codes as described in the literature. The primary outcome of in-hospital mortality and secondary outcomes like length of hospital stay (LOS), and total hospitalization costs were analyzed. Propensity score (PS) using the next neighbor method without replacement with 1:1 matching was utilized to adjust for confounders. Independent risk factors for mortality were identified using a multivariate logistic regression model.

Results

In total, 1,137,108 hospital admissions with a primary diagnosis of ACS were identified, of which 7.46% were obese. In-hospital morality during the index admission was lower among obese patients with ACS compared to non-obese patients (4.62 vs 6.87%, p&lt;0.001) with significantly lower 30-day readmission rates as well (p&lt;0.001). However, in-hospital mortality rates during readmission were statistically equivalent between the obese and non-obese groups (5.6 vs 8.3%, p=0.72). LOS during the index admission was longer for obese patients (6.39 vs 5.36 days, p=0.65) but equivalent to non-obese patients during subsequent readmissions (p=0.12). The total cost of these admissions was significantly more in the obese cohort as well (p&lt;0.001).

Conclusion

In this study, obese elderly patients admitted with ACS were found to have significantly reduced in-hospital mortality and 30-day readmission rates when compared to non-obese patients - reinforcing the obesity paradox independent of patient age.

Funding Acknowledgement

Type of funding source: None

Impact of chronic sequential LV-RV pacing with cardiac resynchronization therapy for patients with narrower (&lt;130 ms) QRS complexes following evaluation of acute myocardial strain characteristics

Background

Prior studies have shown acute improvement in myocardial strain patterns (SP) and strain rates (SR), left ventricular ejection fraction (LVEF), and long-term clinical improvement by Cardiac Resynchronization Therapy (CRT) preferential LV pacing. This relationship has not been studied in patients (pts) with narrower QRS.

Objectives

We aimed to evaluate myocardial speckle tracking SP and SR at different VV intervals in pts with narrow (&lt;130 ms) and wide (&gt;130 ms) QRS.

Methods

We assessed LVEF and speckle tracking myocardial SP and SR as per the American Society of Echocardiography (ASE) Dyssynchrony Writing Group methods in pts with CRT in acute settings at VV0, VV60 and LV-only pacing. For SP assessment, we used Bull's eye format display of the LV segments, and scores for SR, 2 = early stretch, late peak, 1= early stretch, early peak, and 0 = single peak at aortic closure.

Results

Total cohort of 271 pts; age 69.2±10.3 yrs (mean ± SD), male - 60%, divided into 2 groups; Gp A (QRS &lt;130 ms, n=69) and Gp B (QRS &gt;130 ms, n=202). QRS width and LVEF in Gp A and B were 120.1±12.3 ms and 152.1±12.9 ms, and 22.3±9.4% and 23.3±10.2% respectively. With VV0 increase in LVEF, 67±6.0% from baseline 22.3±9.4% was seen in Gp A compared to 43±6.5% from 23.3±10.2% in Gp B (p&lt;0.01). With VV60 and LV-only pacing further rise in LVEF to 100.0±7.1% and 112.0±7.2% in Gp A and 80.2±8.0% and 93±8.1% in Gp B was seen. (Figure 1). Strain scores at different VV timings in both groups are shown in Table 1.

Conclusions

In pts with CRT, different VV timings show differences in acute myocardial speckle tracking SP and SR, and LVEF. These changes are markedly favorable with LV-only and sequential LV-RV pacing even in pts with narrower QRS. Our findings support chronic sequential LV-RV pacing programming in CRT pts with narrow QRS.

Figure 1

Funding Acknowledgement

Type of funding source: None

Predictors of sudden cardiac arrest in adolescents with mitral valve prolapse: an analysis of the nationwide inpatient sample

Background

Mitral valve prolapse (MVP) is the most commonly encountered valvular pathology seen in 2–3% of the general population. Though traditionally regarded as a benign pathology, recent literature suggests that sudden cardiac death is significantly more common in these patients with estimates of 0.2–0.4%/year. The exact underlying mechanism of these higher rates of SCD remain poorly understood. In this study, we aim to identify predictors of sudden cardiac arrest (SCA) in an adolescent population.

Methods

We conducted a retrospective study using the AHRQ-HCUP National Inpatient Sample 2016-2017 for the years 2016-17. All patients (≤18 years) admitted with Mitral valve prolapse were identified using ICD-10 codes and further sub stratified based on presence or absence of sudden cardiac arrest (SCA). Baseline characteristics were obtained and multivariate regression analysis was utilized to identify potential predictors of SCA. Independent risk factors for in-hospital mortality were identified using a proportional hazards model. Complications were defined as per the Agency for Health Care Research and Quality guideline.

Results

We screened a total of 71,473,874 admissions in the NIS database to identify a total of 1,372 adolescent patients admitted with MVP in the years 2016–17. These patients were then sub-categorized based on presence or absence of SCA during the hospitalization. Our findings revealed that patients with SCA were generally slightly older (15y vs 13y, p=0.036, OR-1.1, p=0.007) and more likely female (83.3% vs 13%, p=0.227, OR – 3.55, p=0.57)). Interestingly, patients in the SCA cohort were noted to have almost 4 fold higher rates of Mitral regurgitation (66.6% vs 18.35%, p=0.008, OR-8.89, p=0.005) as well as family history of SCD (16.7% vs 4.1%, p=0.145, OR-4.65, p=0.14).

Conclusions

Presence of Mitral regurgitation and a family history of sudden cardiac death are associated with significantly higher rates of SCA in adolescent patients with mitral valve prolapse.

Predictors of SCA in Adolescent MVP

Funding Acknowledgement

Type of funding source: None

A nationwide 16-year study of the trends, burden and impact of atrial fibrillation in cardiac amyloidosis

Background

Cardiac amyloidosis (CA) remains an underdiagnosed entity. Atrial fibrillation (AF) is common in patients with CA, likely owing to direct amyloid deposition in the left atrium. However, the prevalence of AF in CA and its association with in-hospital outcomes has not been studied in large populations.

Purpose

Our aim was to study the trends, baseline characteristics, and clinical impact of AF in patients with CA in the United States using the Healthcare Cost and Utilization Project (HCUP) National) Inpatient Sample (NIS) from 1999 to 2014.

Methods

We queried the NIS and identified CA using ICD-9-CM codes 277.39 and 425.7. AF in CA patients was identified using the ICD-9-CM code of 427.31. Statistical Analysis System (SAS) 9.4 was used for analysis of data.

Results

There were a total of 145,920 CA hospitalizations between 1999 and 2014 in the United States, of which 37,070 (25.4%) had AF. The prevalence of AF remained consistent from 27.5% in 1999 to 27.4% in 2014.

The mean age of patients with AF was 72.9±28.2 years and for patients without AF was 67±31.9 years (p&lt;0.0001). The majority of the patients with AF were male (60.3%) and the study group was predominantly white (62.8% in patients with AF and 56.4% in patients without AF). CA patients with AF suffered more from thyroid-related disease (22.5% vs 16.1%), heart failure (62.9% vs 36.5%) and renal failure (34.7% vs 30.5%) and less from hypertension (29.3% vs 34.0%) and diabetes mellitus (23.2% vs 25.2%) (p&lt;0.0001). There was no significant difference in the Charlson comorbidity score between the groups.

Inpatient mortality was significantly higher in CA patients with AF (10.4% vs 6.5%, p&lt;0.001). However, in-patient mortality has been decreasing over the years from 10.3% in 1999 to 7.6% in 2014. Furthermore, cardiogenic shock was significantly higher in CA patients with AF (2.1% vs 1.2%, p&lt;0.001), yet the use of mechanical circulatory support was not significantly different between the groups (0.42% vs 0.35%, p=0.375). Pacemaker implantation was also noted to be higher in CA patients with AF compared to patients without AF (2.8% vs 1.2%, p&lt;0.0001).

There was no significant difference between CA patients with and without AF in mean cost of hospitalization ($58222±10752 vs $57695±545, p=0.081) or length of stay (7.9±0.1 vs 7.7±0.1 days, p=0.7089).

Conclusion

CA with atrial fibrillation is a well-recognized entity, and our large scale retrospective analysis found significant association with worse in-hospital outcomes and cardiogenic shock. Interestingly, trend of in-patient mortality in CA has been decreasing over the years, likely owing to improved imaging modalities for diagnosis. Optimal management of AF in CA is imperative to improve outcomes in this population.

Funding Acknowledgement

Type of funding source: None

Efficacy of motivational-interviewing and guided opioid tapering support for patients undergoing orthopedic surgery (MI-Opioid Taper): A prospective, assessor-blind, randomized controlled pilot trial

BACKGROUND

Postoperative opioid use can lead to chronic use and misuse. Few studies have examined effective approaches to taper postoperative opioid use while maintaining adequate analgesia.

METHODS

This randomized, assessor-blinded, pilot trial of postoperative motivational interviewing and guided opioid tapering support (MI-Opioid Taper) added to usual care (UC) enrolled patients undergoing total hip or knee arthroplasty at a single U.S. academic medical center. MI-Opioid Taper involved weekly (to seven weeks) and monthly (to one year) phone calls until patient-reported opioid cessation. Opioid tapering involved 25% weekly dose reductions. The primary feasibility outcome was study completion in the group to which participants were randomized. The primary efficacy outcome, time to baseline opioid use, was the first of five consecutive days of return to baseline preoperative dose. Intention-to-treat analysis with Cox proportional hazards regression was adjusted for operation. ClinicalTrials.gov registration: NCT02070003.

FINDINGS

From November 26, 2014, to April 27, 2018, 209 patients were screened, and 104 patients were assigned to receive MI-Opioid Taper (49 patients) or UC only (55 patients). Study completion after randomization was similar between groups (96.4%, 53 patients receiving UC, 91.8%, 45 patients receiving MI-Opioid Taper). Patients receiving MI-Opioid Taper had a 62% increase in the rate of return to baseline opioid use after surgery (HR 1.62; 95%CI 1.06-2.46; p = 0•03). No trial-related adverse events occurred.

INTERPRETATION

In patients undergoing total joint arthroplasty, MI-Opioid Taper is feasible and future research is needed to establish the efficacy of MI-Opioid Taper to promote postoperative opioid cessation.

FUNDING

National Institute on Drug Abuse.

Breast cancer patients have lower in-hospital mortality after acute coronary syndrome, a 5 year nationwide analysis

Background

Breast cancer and cardiovascular disease (CVD) share common risk factors, and breast cancer therapies are well known to cause cardiotoxicity. Prior studies highlighted the higher burden coronary artery disease and the importance to further assess its consequences on breast cancer patients.

Purpose

We sought to evaluate the revascularization rate and in-hospital short-term outcomes of breast cancer patients following acute coronary syndrome (ACS) compared to the general female population.

Methods

We reviewed the Nationwide Inpatient Sample from 2010 to 2014 to identify female patients with principal diagnosis of ACS (ST-elevation and non ST-elevation myocardial infarction, and unstable angina). Two subgroups were identified, women with a history of breast cancer and women without, and were propensity matched.

Multivariate regression analyses were performed to evaluate the impact of breast cancer on primary outcome (in-hospital mortality) and secondary outcomes: occurrence of shock, acute kidney injury (AKI), mechanical ventilation (MV), and length of stay (LOS). We also compared the rate of cardiac procedures. Statistical significance of odd ratios (OR) is defined with p-value&lt;0.05 and reported 95% confidence intervals (CI).

Results

We identified a total of 245,563 female patients with primary diagnosis of ACS, among them 10,625 (4.3%) had a history of breast cancer. The comorbidity of breast cancer was associated with statistically significant lower rates of mortality (OR 0.83, CI 0.74–0.94), shock (OR 0.87, CI 0.77–0.99), AKI (OR 0.90, CI 0.82–0.98), MV (OR 0.81, CI 0.71–0.92) and relative 5.4% decrease in LOS (CI: −7.8%, −3.0%). The cardiac procedural rates were similar for left heart catheterization (OR 0.96, CI 0.90–1.02), for percutaneous coronary intervention (OR 0.95, CI 0.89–1.02) and for CABG (OR 0.88, CI 0.78–1.00) compared to control group.

Conclusion

Breast cancer patients received a comparable catheterization and revascularization procedure rate and exhibited a statistically significant lower morbidity and mortality rates during hospitalization after an ACS event compared to the general female population.

Funding Acknowledgement

Type of funding source: None

10-year trend analysis of atrioventricular node ablation in patient with atrial fibrillation: 2005–2014 United State hospitalization

Introduction

Atrial fibrillation (AF) ablation and Atrioventricular Node (AVN) ablation are both important non-pharmacological therapy of AF. In spite of increased availability of AF ablation data, that of AVN ablation per se is limited.

Method

AF ablation was identified using ICD-9 procedure code with principle diagnosis of AF from United States National Inpatient Sample database 2005–2014. From procedure and diagnosis codes of pacemaker insertion followed by ablation, the cohort who underwent AVN ablation was identified. Patients hospitalization with any diagnosis of other type of arrythmia or epicardial ablation were excluded. Complications were defined as per the Agency for Health Care Research and Quality guideline.

Results

Total AF ablation was noted to increase from 2005- 2011, and declined steadily from 2011–2014. In contrast, the number of AVN ablations increased from 4505 cases to 5175 (Figure 1). AVN ablation were mainly performed in elderly patient (mean age 72), and increasingly in patient with higher Charlson Commobidity index (0.9 to 1.7)and higher CHA2DS2-VASc score (2.8 to 3.7) (Table 1). An increasing trend in procedure complications but no significant change in mortalitywere observed with AVN ablation. Progressive increase in the length of stay and the hospitalization cost were also observed over the years with AVN ablation.

Conclusion

AVN ablation is being performed at a steady volume, and increasingly in patients with multiple comorbidities. This trend although was not associated with increased mortality, it was associated with increased hospital complications.

Funding Acknowledgement

Type of funding source: None

Prognostic role of positron emission tomography in patients with known or suspected cardiac sarcoidosis. a systematic review and meta-analysis

Background

Sarcoidosis is a chronic inflammatory disorder of unclear etiology, characterized by the presence of non-caseating granulomas. Cardiac involvement occurs in upto 27 percent of patients, manifesting as atrioventricular blocks, ventricular arrhythmia or sudden cardiac death. Current guidelines cite insufficient evidence for the prognostic utility of positron emission tomography (PET) in patients with cardiac sarcoidosis. Thus, we performed a systematic review and meta-analysis of published studies to ascertain the prognostic significance of PET imaging in patients with suspected or diagnosed cardiac sarcoidosis.

Purpose

To review current literature and determine if PET has prognostic utility in patients with known or suspected cardiac sarcoidosis

Methods

We performed a comprehensive literature search of electronic databases (Embase, Medline and Web of Science) using MeSH terms and keywords for sarcoidosis and PET from inception through December 2019. Studies were eligible if they included patients with known and/or suspected cardiac sarcoidosis undergoing evaluation by PET with or without perfusion imaging and reported clinical events of interest. An abnormal PET study was defined as the presence of focal or focal-on-diffuse uptake of 18- fluorodeoxyglucose (18-FDG) by visual analysis. In studies with perfusion imaging, patients with only perfusion defects were excluded. The primary outcome of interest was a composite of major adverse cardiac events (MACE), including sustained ventricular tachycardia, sudden cardiac death. Secondary analysis studied association of MACE with focal right ventricular (RV) uptake in patients with an abnormal PET study. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Heterogeneity of results among the studies was assessed using the Higgins I2 value.

Results

Out of a total of 1645 citations, 40 were selected for full-text review. Five studies were included in the final analysis with a total of 465 patients. mean follow-up was 2.3 years. Three of the five studies also reported frequency of abnormal RV uptake of 18-FDG. Patients with abnormal 18-FDG uptake on visual assessment had higher odds of MACE (OR 3.12, CI 1.9–5.01, p&lt;0.00001), compared to known or suspected cardiac sarcoid patients with normal PET studies. Heterogeneity among studies was low (I2 = 0). In patients with an abnormal PET study, abnormal focal RV uptake of 18-FDG was associated with higher odds of MACE (OR 5.24, CI 1.1–25.1, p=0.04), with moderate heterogeneity among studies (I2=41).

Conclusion

In patients undergoing PET imaging for known or suspected cardiac sarcoidosis, abnormal metabolism on visual analysis is associated with increased risk of MACE. Furthermore, focal RV uptake further increases the risk of MACE in patients with abnormal PET imaging. Thus, PET imaging can serve as a tool to risk stratify patients with known or suspected cardiac sarcoidosis.

Forrest Plots

Funding Acknowledgement

Type of funding source: None

A nationwide analysis of 16 year trends in cardiac transplantation for acute myocarditis

Background

Orthotopic heart transplant (OHT) is indicated in 1–8% of patients with myocarditis. However, national trends in the utilization of transplantation and outcomes in myocarditis across the United States are not well established.

Purpose

Our objective was to study the trends and baseline characteristic of myocarditis patients undergoing heart transplant in the United States using Healthcare Cost and Utilization Project (HCUP) National (nationwide) Inpatient Sample (NIS) from 1999 to 2014.

Methods

Using NIS data, we identified patients older than 18 years with myocarditis using codes ICD9 codes of 422.0 and 422.9. Among these patients, we identified those who underwent cardiac transplantation using ICD9 procedure codes 37.5 and 33.6. We presented categorical data as percentages and continuous data as mean or median as appropriate.

Results

We identified a total of 62,264 hospitalizations for myocarditis from 1999–2014. 430 (0.69%) myocarditis patients underwent OHT which consisted of 0.82% of all 29990 cardiac transplants identified in the same period. The trends in OHT for myocarditis is as shown in Figure 1.

The mean age was 32.9±2.4 years and 51.1% (n=219) were females. 235 (54.6%) were Caucasians and 60 (13.9%) were Hispanic. Majority of the transplants were performed at medium (16%) and large sized hospitals (80.4%). Cardiac transplants were mainly done at teaching hospitals (98.9%). Further, with regards to the geographical distribution of transplant procedure, most were done in the West (37.2%) followed by South (25.3%), Northeast (21.4%) and Mid-west (16%) of the United States. Private insurance was the major payor source which covered 245 (58%) patients followed by Medicaid covering 112 (26%) patients.

A total of 26 (6%) myocarditis patients died during the same hospitalization for OHT. In terms of discharge following OHT in myocarditis 85.8% (n=369) were discharged home and 8.1% (n=35) to short term hospitalization. The average length of stay for OHT for myocarditis was 64.3±6.3 days. Also, the mean cost of hospitalization for heart transplant in myocarditis when adjusted for inflation was 789,566±93,108 dollars.

In-patient mortality following OHT was not significantly different in large sized hospital compared to small and medium sized hospitals (7.6% vs 5.7%, p=0.54). However, the cost of hospitalization was significantly lesser in small and medium sized hospitals (588,363±154,349 vs 826,864±106,110 dollars, p&lt;0.0001).

Conclusions

Only a small percentage of OHT is done for myocarditis with high proportion done in female when compared to OHT for other etiologies. Further studies need to be done to compare long term outcomes of heart transplant in myocarditis.

Funding Acknowledgement

Type of funding source: None

Molecular Docking Study of Active Diazenyl Scaffolds as Inhibitors of Essential Targets Towards Antimicrobial Drug Discovery

BACKGROUND

The diazenyl compounds (-N=N- linkage) have been reported to have antimicrobial activity. In modern drug discovery, the drug-receptor interactions are generally explored by the molecular docking studies.

MATERIALS AND METHODS

Three categories of diazenyl scaffolds were screened for the docking studies to explore the binding mechanism of interaction with various microbial targets. The diazenyl Schiff bases (SBN-20, SBN-21, SBN-25, SBN-33, SBN-39, SBN-40 and SBN-42), naphthol pharmacophore based diazenyl Schiff bases (NS-2, NS-8, NS-12, NS-15, NS-21, and NS-23), morpholine based diazenyl chalcones (MD-6, MD-9, MD-14, MD-16, MD-20, and MD-21) were docked against various bacterial and fungal proteins in comparison with different standard drugs. Further, the drug likeliness and ADME properties of these molecules were predicted by QikProp module of the Schrodinger software.

RESULTS

Most of the derivatives had shown less docking scores and binding energies towards bacterial proteins, such as dihydropteroate synthase (PDB:2VEG), glucosamine-6-phosphate synthase (PDB:2VF5), dihydrofolate reductase (PDB:3SRW) in comparison with the standard drugs. The naphthol based diazenyl Schiff bases NS-21 and NS-23 were predicted to act on the cytochrome P450 sterol 14-alpha-demethylase (CYP51) (PDB:5FSA) involved in sterol biosynthesis, an essential target for antifungal drugs. The derivative MD-6, NS-2, NS-21, and NS-23 had shown high docking scores against bacterial DNA topoisomerase (PDB:3TTZ) in comparison with the standard drug ciprofloxacin. Further, most of the synthesized derivatives had shown drug like characters.

CONCLUSION

Hence, these compounds can be developed as novel antibacterial agents as potent DNA topoisomerase inhibitors and antifungal agents as CYP51 inhibitors.

Phytochemical and pharmacological review of Cinnamomum verum J. Presl-a versatile spice used in food and nutrition

Cinnamomum verum is the widely used spice for its medicinal and culinary uses since ages. It is native to Sri Lanka and southern India but also distributed in many Asian, Caribbean, Australian and African countries. It is widely used in food preparations and industrial products like candies, chewing gums, mouthwash and toothpaste. It is also used to treat asthma, bronchitis, diarrhea, headache, inflammation and cardiac disorders. Cinnamaldehyde, eugenol, caryophyllene, cinnamyl acetate and cinnamic acid are the major compounds found in its essential oil. These compounds exhibit a wide range of pharmacological activities including antioxidant, antimicrobial, anti-inflammatory, anticancer, antidiabetic, wound healing, anti-HIV, anti-anxiety and antidepressant, etc. This review highlights its comprehensive and up-to-date information on taxonomy, ethnomedicinal uses, phytochemical composition, pharmacological and toxicity activities. Structure-activity relationship, mechanism of action and some research gaps has also been provided. Owing to its immense medicinal importance, more well-designed in-vivo and clinical studies are required.

Letermovir Prophylaxis Decreases Burden of Cytomegalovirus (CMV) in Patients at High Risk for CMV Disease Following Hematopoietic Cell Transplant

Despite effective therapies, cytomegalovirus (CMV) continues to have a significant impact on morbidity and mortality in hematopoietic cell transplant recipients. At particular risk are recipients of alternative grafts such as umbilical cord blood (UCB), haploidentical transplants (haplo), or patients conditioned with T-cell depleting regimens such as anti-thymocyte globulin (ATG). With the approval of letermovir, its impact on high-risk patients is of particular interest. To evaluate the impact of letermovir prophylaxis at our center, we performed a retrospective analysis of 114 high-risk patients who received letermovir as prophylaxis (LET PPX) between January 2018 through December 2019, including 30 UCB and 22 haplo recipients, compared with 637 historical controls with comparable risk between January 2013 and December 2019. By post-transplant day 100 (D+100), letermovir prophylaxis significantly decreased the incidence of both CMV DNAemia compared with controls (45.37% versus 74.1%; P < .001) and clinically significant CMV infection (12.04% versus 48.82%; P < .001). The impact of LET PPX was even more profound on the incidence of clinically significant CMV infection (CSI), defined as the administration of antiviral therapy as preemptive therapy for CMV DNAemia or treatment for CMV disease. CSI was significantly lower in haplo recipients on LET PPX compared with controls (13.64% versus 73.33%; P= .02) and UCB recipients on LET PPX compared with controls (3.45% versus 37.5%; P < .001). No patients on LET primary PPX developed CMV disease in any treatment group by D+100 compared with controls (0% versus 5.34%, respectively; P = .006). Patients on LET PPX had fewer hospitalizations involving initiation of anti-CMV therapy compared with controls (0.93% versus 15.23%, respectively). Our analysis of the largest cohort of patients at high risk for CMV reactivation published to date demonstrates that letermovir prophylaxis significantly reduces the number of patients who receive CMV-active antiviral therapy for either DNAemia or disease due to CMV.

Derivation and validation of a prognostic score for neonatal mortality in Ethiopia: a case-control study

Background

Early warning scores for neonatal mortality have not been designed for low income countries. We developed and validated a score to predict mortality upon admission to a NICU in Ethiopia.

Methods

We conducted a retrospective case-control study at the University of Gondar Hospital, Gondar, Ethiopia. Neonates hospitalized in the NICU between January 1, 2016 to June 31, 2017. Cases were neonates who died and controls were neonates who survived.

Results

Univariate logistic regression identified variables associated with mortality. The final model was developed with stepwise logistic regression. We created the Neonatal Mortality Score, which ranged from 0 to 52, from the model’s coefficients. Bootstrap analysis internally validated the model. The discrimination and calibration were calculated. In the derivation dataset, there were 207 cases and 605 controls. Variables associated with mortality were admission level of consciousness, admission respiratory distress, gestational age, and birthweight. The AUC for neonatal mortality using these variables in aggregate was 0.88 (95% CI 0.85–0.91). The model achieved excellent discrimination (bias-corrected AUC) under internal validation. Using a cut-off of 12, the sensitivity and specificity of the Neonatal Mortality Score was 81 and 80%, respectively. The AUC for the Neonatal Mortality Score was 0.88 (95% CI 0.85–0.91), with similar bias-corrected AUC. In the validation dataset, there were 124 cases and 122 controls, the final model and the Neonatal Mortality Score had similar discrimination and calibration.

Conclusions

We developed, internally validated, and externally validated a score that predicts neonatal mortality upon NICU admission with excellent discrimination and calibration.

Synthesis, Characterization, Antimicrobial and Anticancer Studies of Metal Complexes of 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol

BACKGROUND

Being derived from primary amine and aromatic aldehyde, Schiff base and their complexes have an imperative role in the improvement of inorganic chemistry, which are broadly studied as coordination compounds and are gradually becoming more important in biochemical and analytical applications.

METHODS

They have also been used for antibacterial, antifungal, anticancer, antitubercular activities. Novel synthesised Schiff's base 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol (SB) and its metal complexes (Zn[II], Cu[II], Co[II] and Ni[II]) were characterised by UV, IR and NMR spectroscopy. Formation of the Schiff base and the metal (Zn[II], Cu[II], Co[II] and Ni[II]) chelates was supported by spectral and analytical data. The ligand and metal complexes have been screened for their antibacterial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, Klebsiella pneumoniae and antifungal activity against the fungi Candida albicans and Aspergillus niger. Further, the synthesised compounds were also screened for antiproliferative activity against the human colorectal carcinoma (HCT116) cell line using the Sulforhodamine B assay.

RESULT

Metal complexes formed were found to enhance the potency of the Schiff base due to coordination with a copper complex, showing better activity than others.

CONCLUSION

Copper complex was observed to be more potent than other complexes against all the pathogenic microbes and cancer cell line (HCT116).

The automatic construction of bootstrap confidence intervals

The standard intervals, e.g., θ ^ ± 1.96 σ ^ for nominal 95% two-sided coverage, are familiar and easy to use, but can be of dubious accuracy in regular practice. Bootstrap confidence intervals offer an order of magnitude improvement-from first order to second order accuracy. This paper introduces a new set of algorithms that automate the construction of bootstrap intervals, substituting computer power for the need to individually program particular applications. The algorithms are described in terms of the underlying theory that motivates them, along with examples of their application. They are implemented in the R package bcaboot.

In-silico molecular design of heterocyclic benzimidazole scaffolds as prospective anticancer agents

Benzimidazole is a valuable pharmacophore in the field of medicinal chemistry and exhibit wide spectrum of biological activity. Molecular docking technique is routinely used in modern drug discovery for understanding the drug-receptor interaction. The selected data set of synthesized benzimidazole compounds was evaluated for its in vitro anticancer activity against cancer cell lines (HCT116 and MCF7) by sulforhodamine B (SRB) assay. Further, molecular docking study of data set was carried out by Schrodinger-Maestro v11.5 using CDK-8 (PDB code: 5FGK) and ER-alpha (PDB code: 3ERT) as possible target for anticancer activity. Molecular docking results demonstrated that compounds 12, 16, N9, W20 and Z24 displayed good docking score with better interaction within crucial amino acids and corelate to their anticancer results. ADME results indicated that compounds 16, N9 and W20 have significant results within the close agreement of the Lipinski's rule of five and Qikprop rule within the range and these compounds may be taken as lead molecules for the discovery of new anticancer agents.

Synthesis, molecular docking and biological potentials of new 2-(4-(2-chloroacetyl) piperazin-1-yl)-N-(2-(4-chlorophenyl)-4-oxoquinazolin-3(4H)-yl)acetamide derivatives

In the present study, a series of 2-(4-(2-chloroacetyl)piperazin-1-yl)-N-(2-(4-chlorophenyl)-4-oxoquinazolin-3(4H)-yl)acetamide derivatives was synthesized and its chemical structures were confirmed by physicochemical and spectral characteristics. The synthesized compounds were evaluated for their in vitro antimicrobial (tube dilution technique) and anticancer (MTT assay) activities along with molecular docking study by Schrodinger 2018-1, maestro v11.5. The antimicrobial results indicated that compounds 3, 8, 11 and 12 displayed the significant antimicrobial activity and comparable to the standards drugs (ciprofloxacin and fluconazole). The anticancer activity results indicated that compound 5 have good anticancer activity among the synthesized compounds but lower active than the standard drugs (5-fluorouracil and tomudex). Molecular docking study demonstrated that compounds 5 and 7 displayed the good docking score with better anticancer potency within the binding pocket and these compounds may be used as a lead for rational drug designing for the anticancer molecules.

Synthesis and evaluation of novel naphthol diazenyl scaffold based Schiff bases as potential antimicrobial and cytotoxic agents against human colorectal carcinoma cell line (HT-29)

BACKGROUND

In search of new antimicrobial and cytotoxic agents, a series of new naphthol diazenyl scaffold based Schiff bases (NS1-NS23) was efficiently synthesized by condensation of 2-hydroxy naphthaldehyde azo dyes with various substituted aromatic/heteroaromatic/aliphatic amines.

METHODOLOGY

The synthesized derivatives were characterized by various physicochemical and spectral techniques and assessed for in vitro antimicrobial and cytotoxic potential against human colorectal carcinoma cell line (HT-29). The active derivatives were further evaluated for their apoptotic potential by Annexin-V/propidium iodide double staining assay using flow cytometer and analyzed for cell-cycle arrest studies.

RESULTS AND CONCLUSION

The derivative NS-2 was found maximum active against E. coli, S. enterica and B. subtilis. The derivatives NS-12, NS-15, NS-21, and NS-23 showed maximum antifungal activity against A. fumigatus. The maximum cytotoxicity was observed from the derivatives NS-2, NS-8, NS-21, and NS-23 towards HT-29 cell line with IC50 between 4 and 19 μg/ml. More than 90% and 62% of the cells were found in the apoptotic phase on treatment with NS-2 and NS-21 respectively in comparison to the 68% for doxorubicin. Further, these derivatives arrested the cell growth in S and G2/M phase of the cell cycle.

Antimicrobial, antioxidant and cytotoxic evaluation of diazenyl chalcones along with insights to mechanism of interaction by molecular docking studies

BACKGROUND

In continuation of our work, new diazenyl chalcones scaffolds (C-18 to C-27) were efficiently synthesized from substituted acetophenone azo dyes (A-E) by base catalyzed Claisen-Schmidt condensation with different substituted aromatic/heteroaromatic aldehydes.

METHODOLOGY

The synthesized chalcones were assessed for their in vitro antimicrobial potential towards several pathogenic microbial strains by tube dilution method and further evaluated for antioxidant potential by DPPH assay. These derivatives were also assessed for the cytotoxicity towards the human lung cancer cell line (A549) and normal cell line (HEK) by MTT assay. The most active antimicrobial compounds were docked using Schrodinger v18.1 software with the various potential bacterial receptors to explore the mechanism of interaction.

RESULTS

The derivative C-22 exhibited high antibacterial activity with very low MIC (1.95-3.90 µg ml-1) and MBC (3.90-7.81 µg ml-1) values. The derivatives C-23, C-24 and C-27 have demonstrated good antioxidant potential (IC50 = 7-18 µg ml-1) correlated to the ascorbic acid (IC50 = 4.45 µg ml-1). The derivative C-25 had shown comparable cytotoxicity to camptothecin against A549 cell line. The docking studies predicted the bacterial dihydrofolate reductase (PDB ID: 3SRW) and bacterial DNA gyrase (PDB ID: 4ZVI) as the possible targets for most of the active antimicrobial compounds. These derivatives affirmed their safety by presenting less cytotoxicity towards HEK cells. Further the ADME prediction by qikprop module of the Schrodinger proved that these compounds exhibited drug-like attributes.

CONCLUSION

Hence, these compounds have shown their potential as lead for future expansion of novel antimicrobial and cytotoxic drugs.

2-Mercaptobenzimidazole Schiff Bases: Design, Synthesis, Antimicrobial Studies and Anticancer Activity on HCT-116 Cell Line

BACKGROUND

Increased rate of mortality due to the development of resistance to currently available antimicrobial and anticancer agents initiated the need to develop new chemical entities for the treatment of microbial infections and cancer.

OBJECTIVE

The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities of Schiff bases of 2-mercaptobenzimidazole.

METHODS

The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]- imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively.

RESULTS

Compounds 8 (MICpa, an = 2.41, 1.20 µM/ml), 10 (MICse, sa = 2.50 µM/ml), 20 (MICec = 2.34 µM/ml) and 25 (MICca = 1.46 µM/ml) showed significant antimicrobial activity against tested bacterial and fungal strains and compounds 20 (IC50 = 8 µg/ml) and 23 (IC50 = 7 µg/ml) exhibited significant anticancer activity.

CONCLUSION

In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds may be taken as lead molecules for the development of novel antifungal agents.

Three-dimensional Quantitative Structure-activity Relationship (3DQSAR) and Molecular Docking Study of 2-((pyridin-3-yloxy)methyl) Piperazines as α7 Nicotinic Acetylcholine Receptor Modulators for the Treatment of Inflammatory Disorders

BACKGROUND & OBJECTIVE

Comparative molecular field analysis (CoMFA) of 27 analogues of 2-((pyridin-3-yloxy)methyl)piperazine derivatives was carried out using software Tripos SYBYL X. Optimal r2 (0.854) and q2 (0.541) values were obtained for the developed 3D-QSAR model. The contour plots obtained from CoMFA analysis have shown 13.84% steric contribution and 66.14% electrostatic contribution towards an anti-inflammatory activity.

METHODS

The homology model of the receptor protein, α7 nicotinic acetylcholine, was generated in SWISS MODELLER using auto template mode and was analysed for the quality using Procheck, QMEAN Z-score, Anolea and GROMOS plots. The QMEAN score for the model was observed to be - 3.862. The generated model of alpha 7 nicotinic acetylcholine receptor was used for docking study of 27 piperazine analogues using Auto-Dock 4.2.5.1.

RESULTS

The dock score obtained from docking analysis was then correlated with experimental pIC50 values for in-silico validation of the developed CoMFA model and a good correlation was obtained with correlation coefficient (r2) value of -0.7378.

CONCLUSION

The present investigation suggests an optimal 3D-QSAR with CoMFA model for further evaluating new chemical entities based on piperazine skeleton.

Computational approaches: discovery of GTPase HRas as prospective drug target for 1,3-diazine scaffolds

Heterocyclic 1,3-diazine nucleus is a valuable pharmacophore in the field of medicinal chemistry and exhibit a wide spectrum of biological activities. PharmMapper, a robust online tool used for establishing the target proteins based on reverse pharmacophore mapping. PharmMapper study is carried out to explore the pharmacological activity of 1,3-diazine derivatives using reverse docking program. PharmMapper, an open web server was used to recognize for all the feasible target proteins for the developed compounds through reverse pharmacophore mapping. The results were analyzed via molecular docking with maestro v11.5 (Schrodinger 2018-1) using GTPase HRas as possible target. The molecular docking studies displayed the binding behavior of 1,3-diazine within GTP binding pocket. From the docking study compounds s3 and s14 showed better docked score with anticancer potency against cancer cell line (HCT116). Hence, the GTPase HRas may be the possible target of 1,3-diazine derivatives for their anticancer activity where the retrieved information may be quite useful for developing rational drug designing. Furthermore the selected 1,3-diazine compounds were evaluated for their in vitro anticancer activity against murine macrophages cell line. 1,3-Diazine compounds exhibited good selectivity of the compounds towards the human colorectal carcinoma cell line instead of the murine macrophages. The toxicity study of the most active compounds was also performed on non cancerous HEK-293 cell line.

Molecular docking, synthesis and biological significance of pyrimidine analogues as prospective antimicrobial and antiproliferative agents

Pyrimidine nucleus is a significant pharmacophore that exhibited excellent pharmacological activities. A series of pyrimidine scaffolds was synthesized and its chemical structures were confirmed by physicochemical and spectral analysis. The synthesized compounds were evaluated for their antimicrobial potential towards Gram positive and negative bacteria as well as fungal species. They were also assessed for their anticancer activity toward a human colorectal carcinoma cell line (HCT116). Whilst results of antimicrobial potential revealed that compounds Ax2, Ax3, Ax8 and Ax14 exhibited better activity against tested microorganisms, the results of antiproliferative activity indicated that compounds Ax7 and Ax10 showed excellent activity against HCT116. Further, the molecular docking of pyrimidine derivatives Ax1, Ax9 and Ax10 with CDK8 (PDB id: 5FGK) protein indicated that moderate to better docking results within the binding pocket. Compounds Ax8 and Ax10 having significant antimicrobial and anticancer activities may be selected as lead compounds for the development of novel antimicrobial and anticancer agent, respectively.

Benzimidazole scaffolds as promising antiproliferative agents: a review

Cancer is one of the most serious medical problem and second leading cause of death in the world, characterized by a deregulation of the cell cycle which mainly results in a progressive loss of cellular differentiation and uncontrolled cellular growth. The benzimidazole is a heterocyclic moiety found in extensive number of natural and biological active molecules. Benzimidazole derivatives might be considered as auxiliary isosters of nucleotides having attached heterocyclic cores in their structures, cooperate effortlessly with biopolymers and have potential action for chemotherapeutic applications. Benzimidazole and its derivatives displayed a wide range of biological activity because of its structural similarity with the naturally occurring nucleotides. Benzimidazole has established huge alertness in current time and is extremely significant heterocyclic pharmacophore in recent drug innovation and medicinal chemistry. The present review summarizes the chemistry of various substituted benzimidazole derivatives with their antiproliferative significance towards the various cancer cell lines such as HCT116, MCF7, HeLa, HepG2, A549 and A431.

Indole hybridized diazenyl derivatives: synthesis, antimicrobial activity, cytotoxicity evaluation and docking studies

Background

In search of effective antimicrobial and cytotoxic agents, a series of indole hybridized diazenyl derivatives (DS-1 to DS-21) was efficiently prepared by condensation of diazotized p-aminoacetophenone with indole or nitroindole followed by reaction with different aromatic/heteroaromatic amines of biological significance. The synthesized derivatives were characterized by various spectroscopic techniques.

Methodology

The antimicrobial evaluation of DS-1 to DS-23 was done by tube dilution method against various pathogenic bacterial and fungal strains. The active antimicrobial derivatives were further evaluated for cytotoxicity against human lung carcinoma cell line (HCT-116), breast cancer cell line (MDAMB231), leukemic cancer cell line (K562), and normal cell line (HEK293) by MTT assay using doxorubicin as the standard drug. The test derivatives were additionally docked for the B-subunit of enzyme DNA gyrase from E. coli at the ATPase binding site to study the molecular interactions using Schrodinger maestro v11.5 software.

Results and discussion

Most of the synthesized derivatives have shown high activity against Gram-negative bacteria particularly E. coli and K. pneumonia with MIC ranging from 1.95 to 7.81 μg/ml. The derivatives have demonstrated very less activity against tested Gram positive bacterial and fungal strains. The derivatives DS-14 and DS-20 have been found to active against breast cancer cell line and human colon carcinoma cell line having IC₅₀ in the range of 19–65 µg/ml. All the derivatives were found to less potent against leukemic cancer cell line. The synthesized derivatives have revealed their safety by exhibiting very less cytotoxicity against the normal cell line (HEK-293) with IC₅₀ > 100 µg/ml. Most of the active derivatives have shown good docking scores in comparison to the standard drugs against DNA gyrase from E. coli. Further ADME predictions by Qikprop module of the Schrodinger confirmed these molecules have drug like properties.

Conclusion

The derivatives DS-14 and DS-20 have shown potential against Gram-negative bacteria and breast cancer cell line and can be used as a lead for rational drug designing of the antimicrobial and cytotoxic agents..