Identification of Disalicyloyl Curcumin as a Potential DNA Polymerase Inhibitor for Marek's Disease Herpesvirus: A Computational Study Using Virtual Screening and Molecular Dynamics Simulations

Marek's disease virus (MDV) is a highly contagious and persistent virus that causes T-lymphoma in chickens, posing a significant threat to the poultry industry despite the availability of vaccines. The emergence of new virulent strains has further intensified the challenge of designing effective antiviral drugs for MDV. In this study, our main objective was to identify novel antiviral phytochemicals through in silico analysis. We employed Alphafold to construct a three-dimensional (3D) structure of the MDV DNA polymerase, a crucial enzyme involved in viral replication. To ensure the accuracy of the structural model, we validated it using tools available at the SAVES server. Subsequently, a diverse dataset containing thousands of compounds, primarily derived from plant sources, was subjected to molecular docking with the MDV DNA polymerase model, utilizing AutoDock software V 4.2. Through comprehensive analysis of the docking results, we identified Disalicyloyl curcumin as a promising drug candidate that exhibited remarkable binding affinity, with a minimum energy of -12.66 Kcal/mol, specifically targeting the DNA polymerase enzyme. To further assess its potential, we performed molecular dynamics simulations, which confirmed the stability of Disalicyloyl curcumin within the MDV system. Experimental validation of its inhibitory activity in vitro can provide substantial support for its effectiveness. The outcomes of our study hold significant implications for the poultry industry, as the discovery of efficient antiviral phytochemicals against MDV could substantially mitigate the economic losses associated with this devastating disease.

Inhibitor Assessment against the LpxC Enzyme of Antibiotic-resistant Acinetobacter baumannii Using Virtual Screening, Dynamics Simulation, and in vitro Assays

BACKGROUND

Bacterial resistance is currently a significant global public health problem. Acinetobacter baumannii has been ranked in the list of the World Health Organization as the most critical and priority pathogen for which new antibiotics are urgently needed. In this context, computational methods play a central role in the modern drug discovery process. The purpose of the current study was to identify new potential therapeutic molecules to neutralize MDR A. baumannii bacteria.

METHODS

A total of 3686 proteins retrieved from the A. baumannii proteome were subjected to subtractive proteomic analysis to narrow down the spectrum of drug targets. The SWISS-MODEL server was used to perform a 3D homology model of the selected target protein. The SAVES server was used to evaluate the overall quality of the model. A dataset of 74500 analogues retrieved from the PubChem database was docked with LpxC using the AutoDock software.

RESULTS

In this study, we predicted a putative new inhibitor for the Lpxc enzyme of A. baumannii. The LpxC enzyme was selected as the most appropriate drug target for A. baumannii. According to the virtual screening results, N-[(2S)-3-amino-1-(hydroxyamino)-1-oxopropan-2-yl]-4-(4-bromophenyl) benzamide (CS250) could be a promising drug candidate targeting the LpxC enzyme. This molecule shows polar interactions with six amino acids and non-polar interactions with eight other residues. In vitro experimental validation was performed through the inhibition assay.

CONCLUSION

To the best of our knowledge, this is the first study that suggests CS250 as a promising inhibitory molecule that can be exploited to target this gram-negative pathogen.

Pregnancy and epilepsy: a retrospective study of 100 pregrancies

Introduction

Epilepsy is a common neurological disorder in obstetric practice it's prevalence is estimated around 0.3 to 0.7%. Pregnant women with epilepsy are commonly considered to be at high risk for complications during pregnancy or delivery therefore requires targeted and appropriate management.

Objectives

This study evaluated obstetric and neonatal outcome in epileptic pregnant women and to assess targeted management of pregnancy and childbirth.

Methods

Across sectional study was conducted among 100 epileptic patients who gave birth between 2015 and 2019 at the Maternity and Neonatology departments of both Farhat Hached and Monastir University Hospitals.

Results

The mean age of our patients was 29.87 years and 33.7% were primiparous. Only 19% of patients had a planned pregnancy and 71% had at least the 5 recommended prenatal follow-up. Overall 86% of our patients were under and antiepileptic medication and 52% received Folic acid supplementation. The fetal complications were advanced term in (17.85%); premature birth (5.5%); fetal death in utero (2%), low birth weight (4.3%) and macrosomia (8.7%). A significant statistical association was found between poly-therapy, low birth weight (P = 0.01) and fetal death in utero (P = 0.025). A statistical association was found between the use of Larnotrigine and gestational diabetes (p = 0.002).

Conclusions

A significant association of epilepsy, exposure to antiepileptic drugs, and adverse outcomes exists in pregnancy. Management at early stage of pregnancy, or even preconception, seems necessary in view of planning the pregnancy, studying the risks and re-evaluating the effectiveness of the treatment previously used.

Key messages

Pregnant women with epilepsy are commonly considered to be at high risk for complications during pregnancy or delivery. health professionals must planthe pregnancy, studying the risks and re-evaluating the effectiveness of the treatment.

Identification of a Potential Inhibitor Targeting MurC Ligase of the Drug Resistant Pseudomonas aeruginosa Strain through Structure-Based Virtual Screening Approach and In Vitro Assay

BACKGROUND & OBJECTIVE

Pseudomonas aeruginosa shows resistance to a large number of antibiotics, including carbapenems and third generation cephalosporin. According to the World Health Organization global report published in February 2017, Pseudomonas aeruginosa is on the priority list among resistant bacteria, for which new antibiotics are urgently needed. Peptidoglycan serves as a good target for the discovery of novel antimicrobial drugs.

METHODS

Biosynthesis of peptidoglycan is a multi-step process involving four mur enzymes. Among these enzymes, UDP-N-acetylmuramate-L-alanine ligase (MurC) is considered to be an excellent target for the design of new classes of antimicrobial inhibitors in gram-negative bacteria.

RESULTS

In this study, a homology model of Pseudomonas aeruginosa MurC ligase was generated and used for virtual screening of chemical compounds from the ZINC Database. The best screened inhibitor i.e. N, N-dimethyl-2-oxo-2,3-dihydro-1H-1,3-benzodiazole-5-sulfonamide was then validated experimentally through inhibition assay.

CONCLUSION

The presented results based on combined computational and in vitro analysis open up new horizons for the development of novel antimicrobials against this pathogen.

Les rechutes dans la schizophrénie ; comment prévenir?

Dans le domaine de la pathologie psychotique, les rechutes représentent une problématique importante dans la trajectoire des sujets schizophrènes. À l’origine de nombreuses réhospitalisations, ces rechutes sont généralement liées à un défaut d’observance. Et lorsqu’on s’intéresse à cette dynamique, on s’aperçoit que la plupart des études qui se sont intéressées à l’observance médicamenteuse et aux comportements visant à améliorer celle-ci se sont avérées décevantes dans le domaine de la pathologie psychotique. Les progrès réalisés dans le traitement de la schizophrénie n’ont jusqu’ici pas modifié de manière radicale l’importance de l’adhésion des patients à leur médication, ni même la fréquence des rechutes. Si la rechute touche de 10 à 60 % des sujets schizophrènes selon les études, les taux de bonne observance médicamenteuse avoisinent 50 % pour l’ensemble des spécialités médicales et tombent parfois à moins de 20 % dans le domaine de la schizophrénie. Les raisons principales de cette problématique sont pour la plupart des auteurs liées à un manque d’efficacité de la molécule prescrite, à la survenue d’effets secondaires handicapants, à la présence de convictions personnelles désadaptées, voire à la pathologie elle-même. Dans un tel contexte, il semble intéressant de développer de nouvelles stratégies de prescription permettant de parvenir le plus rapidement possible à une dose minimale efficace, voire d’explorer d’autres options thérapeutiques. La revue de la littérature réalisée ici fait un point sur les études récemment publiées (2002–2008) mettant en exergue l’impact que la prescription d’un neuroleptique classique, d’un antipsychotique atypique per os ou d’un APAP peut avoir sur l’observance médicamenteuse et la fréquence des rechutes de patients souffrant de schizophrénie.

[The degree of chronic renal failure is associated with the rate of pro-inflammatory cytokines, hyperhomocysteinemia and with oxidative stress]

AIM

To evaluate pro-inflammatory cytokines, homocysteinemia and markers of oxidative status in the course of chronic renal failure.

PATIENTS AND METHODS

One hundred and two patients (male/female: 38/64; age: 45±07 years) with chronic renal failure were divided into 4 groups according to the National Kidney Foundation classification. They included 28 primary stage renal failure patients, 28 moderate stage renal failure, 28 severe stage renal failure and 18 end stage renal failure. The inflammatory status was evaluated by the determination of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6) and total homocysteine. Pro-oxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase.

RESULTS

Inflammatory markers were elevated in the end stage renal failure group compared to the other groups (P<0.001). Indeed, an increase in thiobarbituric acid reactive substances, hydroperoxides and protein carbonyls was noted in the end stage renal failure group in comparison with the other groups (P<0.001), while the levels of antioxidants enzymes activity were decreased in the study population (P<0.001).

CONCLUSION

Impaired renal function is closely associated with the elevation of inflammatory markers leading to both increased markers of oxidative stress and decreased antioxidant defense.

Homology modeling and virtual screening approaches to identify potent inhibitors of VEB-1 β-lactamase

BACKGROUND

blaVEB-1 is an integron-located extended-spectrum β-lactamase gene initially detected in Escherichia coli and Pseudomonas aeruginosa strains from south-east Asia. Several recent studies have reported that VEB-1-positive strains are highly resistant to ceftazidime, cefotaxime and aztreonam antibiotics. One strategy to overcome resistance involves administering antibiotics together with β-lactamase inhibitors during the treatment of infectious diseases. During this study, four VEB-1 β-lactamase inhibitors were identified using computer-aided drug design.

METHODS

The SWISS-MODEL tool was utilized to generate three dimensional structures of VEB-1 β-lactamase, and the 3D model VEB-1 was verified using PROCHECK, ERRAT and VERIFY 3D programs. Virtual screening was performed by docking inhibitors obtained from the ZINC Database to the active site of the VEB-1 protein using AutoDock Vina software.

RESULTS AND CONCLUSION

Homology modeling studies were performed to obtain a three-dimensional structure of VEB-1 β-lactamase. The generated model was validated, and virtual screening of a large chemical ligand library with docking simulations was performed using AutoDock software with the ZINC database. On the basis of the dock-score, four molecules were subjected to ADME/TOX analysis, with ZINC4085364 emerging as the most potent inhibitor of the VEB-1 β-lactamase.

Three-Dimensional Structure of Arabidopsis thaliana Lipase Predicted by Homology Modeling Method

Triacylglycerol lipases have been thoroughly characterized in mammals and microorganisms. By contrast, very little is known about plant lipases. In this investigation, a homology model of Arabidopsis thaliana lipase (NP_179126) was constructed using a human gastric lipase (PDB ID: 1HLG), as a template for model building. This model was then assessed for stereochemical quality and side chain environment. Natural substrates: tributyrin, trioctanoin and triolen were docked into the model to investigate ligand-substrate interaction.

Medial displacement of T-tubes: case report

Medial displacement of T-tubes is rare and only 6 cases have been reported in literature. We report a case of a medial displacement of a T-tube in the middle ear behind an intact tympanic membrane with normal mobility. No treatment was undergone as the patient was asymptomatic and no hearing problems were detected. A brief overview of this unusual complication of tympanostomy tubes is presented and the management strategy is discussed.

Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide

The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH)2 was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 degrees C are Cr2O3 and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 degrees C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographs show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 degrees C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 degrees C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO4 and CaCO3.