Hartmann's procedure in rectal cancer surgery is often an intraoperative decision: a retrospective multicenter study.

PURPOSE: This study aimed to investigate patient-related factors predicting the selection of rectal cancer patients to Hartmann's procedure as well as to investigate how often, and on what grounds, anterior resection is intraoperatively changed to Hartmann's procedure. METHODS: Prospectively collected data from the Swedish Colorectal Cancer Registry regarding patients with rectal cancer operated upon from January 1 2007 to June 30 2017 in the county of Skåne were retrospectively reviewed. Data were expanded with further details from medical charts. A univariable analysis was performed to investigate variables associated with unplanned HP and significant variables included in a multivariable logistic regression analysis. RESULTS: Altogether, 1141 patients who underwent Hartmann's procedure (275 patients, 24%), anterior resection (491 patients, 43%), or abdominoperineal resection (375 patients, 33%) were included. Patients undergoing Hartmann's procedure were significantly older and had more frequently comorbidity. The decision to perform Hartmann's procedure was made preoperatively in 209 (76%) patients, most commonly because of a comorbidity (27%) or oncological reasons (25%). Patient preference was noted in 8% of cases. In 64 cases (23%), the decision was made intraoperatively, most often due to anastomotic difficulties (60%) and oncological reasons (22%). Anastomotic difficulties were most often reported due to technical difficulties, a low tumor or neoadjuvant radiotherapy. Male gender was a significant risk factor for undergoing unplanned Hartmann's procedure. CONCLUSIONS: The decision to perform Hartmann's procedure was frequently made intraoperatively. Hartmann's procedure should be considered and discussed preoperatively in old and frail patients, especially in the presence of mid-rectal cancer and/or male gender, since these factors increase the risk of intraoperative anastomotic difficulties.

Synthesis of novel hybrid pharmacophore of N-((4-sulfamoylphenyl)carbamothioyl)alkanamides as potent carbonic anhydrase-II and 15-lipoxygenase inhibitors.

A series of N-((4-sulfamoylphenyl)carbamothioyl)alkanamides (5a-j) were synthesized by the reaction of sulphanilamide in dry acetone with freshly prepared alkyl and acyl isothiocyanates (5a-j). The structures of products were confirmed by IR, 1 H, and 13 C NMR. The synthesized compounds were screened as inhibitors of the bovine erythrocyte carbonic anhydrase isoform II (bCA II) and 15-lipoxygenase enzyme (15-LOX). Most of the derivatives showed significant activity against bCA-II while only few compounds were found active against 15-LOX. Molecular docking studies of most active compounds were carried out against bCA II as well as 15-LOX to rationalize the binding mode and interactions of compound in the active sites. Additionally, the pharmacokinetic properties of the compounds were predicted through computational tools, which reflect that these compounds possess acceptable pharmacokinetic profile and good drug-likeness.

Sarcorucinine-D Inhibits Cholinesterases and Calcium Channels: Molecular Dynamics Simulation and In Vitro Mechanistic Investigations.

Acetylcholinesterase (AChE) inhibitors and calcium channel blockers are considered effective therapies for Alzheimer's disease. AChE plays an essential role in the nervous system by catalyzing the hydrolysis of the neurotransmitter acetylcholine. In this study, the inhibition of the enzyme AChE by Sarcorucinine-D, a pregnane type steroidal alkaloid, was investigated with experimental enzyme kinetics and molecular dynamics (MD) simulation techniques. Kinetics studies showed that Sarcorucinine-D inhibits two cholinesterases-AChE and butyrylcholinesterase (BChE)-noncompetitively, with Ki values of 103.3 and 4.66 µM, respectively. In silico ligand-protein docking and MD simulation studies conducted on AChE predicted that Sarcorucinine-D interacted via hydrophobic interactions and hydrogen bonds with the residues of the active-site gorge of AChE. Sarcorucinine-D was able to relax contractility concentration-dependently in the intestinal smooth muscles of jejunum obtained from rabbits. Not only was the spontaneous spasmogenicity inhibited, but it also suppressed K+-mediated spasmogenicity, indicating an effect via the inhibition of voltage-dependent Ca2+ channels. Sarcorucinine-D could be considered a potential lead molecule based on its properties as a noncompetitive AChE inhibitor and a Ca2+ channel blocker.

Protonation states at different pH, conformational changes and impact of glycosylation in synapsin Ia.

Synapsin I (SynI) is the most abundant brain phosphoprotein present at presynaptic terminals that regulates neurotransmitter release, clustering of synaptic vesicles (SVs) at active zones, and stimulates synaptogenesis and neurite outgrowth. Earlier studies have established that SynI displays pH-dependent tethering of SVs to actin filaments and exhibits a maximum binding around neutral pH, however, the effect of pH shift from acidic to basic on the conformational stability of SynI has not been explored yet. Another important aspect of SynIa is its O-GlcNAcylation (O-GlcNac) at the Thr87 position, which is responsible for the positive regulation of synaptic plasticity linked to learning and memory in mice. Furthermore, reduced levels of O-GlcNAc have been observed in Alzheimer's disease, suggesting a possible link to deficits in synaptic plasticity. In this study, the effect of pH and glycosylation on the structure and functional stability of SynIa is determined through molecular dynamics (MD) simulation approach. The 3D structure of SynIa was established via threading-based homology modeling methods. It was observed that the structure of SynIa adopts extended conformational changes as the pH shifts from acidic to basic, resulting in a compact conformation at pH 8.0. Moreover, the results obtained by comparing the glycosylated and unglycosylated protein indicated that the glycan moiety imparts stability to the protein by forming intramolecular hydrogen bond interactions with the protein residues. The results indicate that although O-GlcNAc moieties do not induce a significant change in SynIa structure they minimize protein dynamics, likely leading to enhanced protein stability.

Pulling the Brakes on Fast and Furious Multiple Drug-Resistant (MDR) Bacteria.

Life-threatening bacterial infections have been managed by antibiotics for years and have significantly improved the wellbeing and lifetime of humans. However, bacteria have always been one step ahead by inactivating the antimicrobial agent chemically or by producing certain enzymes. The alarming universal occurrence of multidrug-resistant (MDR) bacteria has compelled researchers to find alternative treatments for MDR infections. This is a menace where conventional chemotherapies are no longer promising, but several novel approaches could help. Our current review article discusses the novel approaches that can combat MDR bacteria: starting off with potential nanoparticles (NPs) that efficiently interact with microorganisms causing fatal changes in the morphology and structure of these cells; nanophotothermal therapy using inorganic NPs like AuNPs to destroy pathogenic bacterial cells; bacteriophage therapy against which bacteria develop less resistance; combination drugs that act on dissimilar targets in distinctive pathways; probiotics therapy by the secretion of antibacterial chemicals; blockage of quorum sensing signals stopping bacterial colonization, and vaccination against resistant bacterial strains along with virulence factors. All these techniques show us a promising future in the fight against MDR bacteria, which remains the greatest challenge in public health care.

Anti-diarrheal activities of phytol along with its possible mechanism of action through in-vivo and in-silico models.

Phytol (PHY), a chlorophyll-derived diterpenoid, exhibits numerous pharmacological properties, including antioxidant, antimicrobial, and anticancer activities. This study evaluates the anti-diarrheal effect of phytol (PHY) along with its possible mechanism of action through in-vivo and in-silico models. The effect of PHY was investigated on castor oil-induced diarrhea in Swiss mice by using prazosin, propranolol, loperamide, and nifedipine as standards with or without PHY. PHY at 50 mg/kg (p.o.) and all other standards exhibit significant (p < 0.05) anti-diarrheal effect in mice. The effect was prominent in the loperamide and propranolol groups. PHY co-treated with prazosin and propranolol was found to increase in latent periods along with a significant reduction in diarrheal section during the observation period than other individual or combined groups. Furthermore, molecular docking studies also suggested that PHY showed better interactions with the α- and ß-adrenergic receptors, especially with α-ADR1a and ß-ADR1. In the former case, PHY showed interaction with hydroxyl group of Ser192 at a distance of 2.91Å, while in the latter it showed hydrogen bond interactions with Thr170 and Lys297 with a distance of 2.65 and 2.72Å, respectively. PHY exerted significant anti-diarrheal effect in Swiss mice, possibly through blocking α- and ß-adrenergic receptors.

Drug utilization and cost associated with inflammatory bowel disease management in Saudi Arabia.

BACKGROUND: There has been an increase in incidence and prevalence of inflammatory bowel disease (IBD) outside the western countries. Treatment costs are an essential component for healthcare planning and priority setting. The utilization patterns and annual administration and cost of IBD medications are largely unknown in countries with an increasing incidence of disease, Saudi Arabia being an example. AIM: To evaluate the use of non-biologic and biologic agents and their associated annual administration costs in a sample of patients with Crohn's disease (CD) and ulcerative colitis (UC) in Saudi Arabia. METHODS: Single-center retrospective chart review was performed to determine the use of biologic and non-biologic medications among IBD patients in a tertiary care hospital in Riyadh, Saudi Arabia. Daily and the annual acquisition cost of different IBD therapeutic agents was calculated. The utilization rates and cost of each type of medication by CD and UC patients were compared. RESULTS: Data of 258 CD patients and 249 UC patients were analyzed. Infliximab and adalimumab were the most commonly prescribed biologics among the study sample, however, their utilization rates were significantly higher among CD than UC patients (36.82% vs. 11.24%, and 20.54% vs. 9.64%, respectively, P < 0. 01). Azathioprine utilization rate was also higher among CD patients compared to their UC counterparts (71.71% vs. 40.16%, respectively, P < 0.01). However, the utilization rate of mesalazine in the UC patients was significantly higher than their CD counterparts (85.53% vs. 14.34% for CD, P < 0.01). The annual cost of biologics (including administration and lab test cost) ranged from 5572 USD for ustekinumab to 18,424 USD for vedolizumab. On the other hand, the annual cost of non-biologics ranged from 16 USD for prednisone to 527 USD for methotrexate. CONCLUSION: Biologics are extensively used in the management of IBD, particularly CD, and their utilization costs are significantly higher than non-biologics. Future studies should examine the cost effectiveness of IBD medications especially in countries with increasing incidence such as Saudi Arabia.

Synthesis, carbonic anhydrase inhibitory activity and antioxidant activity of some 1,3-oxazine derivatives.

Hit, Lead & Candidate Discovery A series of 1-(6-methyl-2-substituted phenyl-4-thioxo-4H-1,3-oxazin-5-yl)ethanones (3a-n) were synthesized by the reaction of benzoyl isothiocyanates with active methylene compound acetylacetone in the presence of triethyl amine in a one-pot process. The structures of the products were elucidated by elemental analyses, FT-IR, 1 H NMR, 13 C NMR, and mass spectroscopy. These new 1,3-oxazine derivatives were evaluated for their inhibitory activity against carbonic anhydrase II. Results for in vitro assay revealed that compound 3b having 4-methoxy phenyl moiety was the most potent inhibitor with IC50 value of 0.144 ± 0.008 µM. It exhibited higher enzyme inhibitory activity as compared to the standard acetazolamide (IC50 = 0.997 ± 0.061 µM). The compounds 3c, 3h, and 3n also displayed superior inhibitory activities compared to the rest of the synthesized oxazine derivatives. The radical scavenging activity of oxazine derivatives was also performed and it was found that compounds showed moderate antioxidant activity. Lipinski rule confirmed the therapeutic potential of the synthesized compounds. Molecular docking studies were also performed to further understand the binding affinity of these compounds with PDBID 1V9E which confirmed that the synthesized derivatives bind in the active binding site of the target protein. Based upon our results, it is proposed that compound 3b may serve as a lead structure to design more potent carbonic anhydrase inhibitors.

Navigating the terrain of neutrophil extracellular traps in severe malaria pathogenesis.

Du, Ren, et al. recently showed in a Plasmodium berghei ANKA (PbA) experimental malaria model that phosphatase of regenerating liver 2 (PRL2) regulates neutrophil extracellular traps (NETs) in severe malaria (SM)-related acute lung injury (ALI). PRL2 deficiency caused SM with ALI in a mouse model by increasing NETs in pulmonary tissue; hydroxychloroquine (HCQ) may ameliorate this.

Does inclusive leadership influence task performance of hospitality industry employees? Role of psychological empowerment and trust in leader.

Drawing on the social exchange theory, this research advances the understanding of leadership and task performance in the hospitality industry in China by exploring the impact of inclusive leadership on the task performance of subordinates working in dyadic forms. The current literature is scarce on the role of leadership in increasing the task performance of employees working in teams in dyadic forms. Multi-level sample of 410 leaders-subordinates in the hospitality industry was used to derive the research findings using PLS-SEM. The results indicated a positive influence of inclusive leadership on the task performance of subordinates. Psychological empowerment mediated this direct relationship. In addition, trust in leaders strengthened the direct link of inclusive leadership with task performance and psychological empowerment. The findings demonstrate that leaders in the hospitality industry should adopt an inclusive leadership style as it contributes to employee task performance, which improves the industry's performance.

Evaluation of sodium citrate anticoagulant for the Resolution of edta-dependent pseudo Thrombocytopenia.

BACKGROUND: EDTA-dependent pseudo thrombocytopenia (EDTA-PTCP) refers to a falsely low platelet count occurring in the presence of ethylene diamine tetra-acetic acid (EDTA) anticoagulant during blood sample collection, which results in the formation of platelet clumps in vitro. This phenomenon has significant clinical implications, including unnecessary administration of platelets. Our study aims to evaluate the efficacy of sodium citrate anticoagulant for the resolution of EDTAPTCP. METHODS: This retrospective study was conducted in the haematology laboratory of Shifa International Hospital (SIH), Pakistan. Patients with pseudo thrombocytopenia (i.e. platelet count less than 150,000/ul with platelet clumps seen on peripheral smear) were included in this study if they had blood samples drawn in both EDTA and sodium citrate tubes less than 48 hours apart. Data was analyzed using IBM® SPSS Software Version 22. RESULTS: A total of 151 study participants were included in this study. The mean age was 48.95±20.69 years and the majority were female (52.3%). Wilcoxon signed-rank test showed that there was a statistically significant difference in platelet count measured in both tubes (Z = -3.223, p=0.001). Overall, blood samples processed in sodium citrate tubes showed lower platelet count than EDTA samples. Sodium citrate anticoagulant was able to correct EDTA-PTCP in 47 (31.1%) of the cases. CONCLUSIONS: Sodium citrate anticoagulant was only able to resolve one-third of our EDTA-PTCP cases. Our findings do not support the use of sodium citrate as a suitable alternative for correction of EDTA-PTCP.

Structure-Based Discovery of Potent Staphylococcus aureus Thymidylate Kinase Inhibitors by Virtual Screening.

INTRODUCTION: Multidrug-resistant bacteria are rapidly increasing worldwide, increasing antibiotic resistance. The exploitation, misuse, overuse, and decrease of the therapeutic potential of currently available antibiotics have resulted in the development of resistance against bacteria. As the most common bacterial pathogen in humans, Staphylococcus aureus can cause many adverse health effects. In fighting multidrug-resistant Staphylococcus aureus, scientists have identified an extremely relevant target - SaTMPK. SaTMPK is essential for DNA synthesis, which, in turn, is necessary for the replication and cell division of bacteria. OBJECTIVE: To perform multi-stage screening using the ZINC database, followed by molecular docking, ADMET profiling, molecular dynamics simulations, and energy calculations. METHODS: Based on the similar pharmacophoric characteristics of existing SaTMPK crystal structures, a model of interaction-based pharmacophores was developed. We then performed molecular docking studies on the positive hits obtained from the pharmacophore screening. Compounds that exhibited good molecular interactions within the SaTMPK binding sites were further evaluated using in-silico ADMET profiling. RESULTS: In a multi-stage screening campaign, three compounds were shortlisted that exhibited physicochemical characteristics suitable for human administration. CONCLUSION: The findings from this study should contribute to in vitro and in vivo studies for clinical applications.

Relative assessment of different statistical instruments and measures for the prediction of promising outcomes using docking, virtual screening and ADMET analysis against HIV-RT.

Reverse transcriptase is the most therapeutic target for the discovery of novel, potent, and non-toxic new anti-retroviral drugs. In the present work, various docking software such as Sybyl Surflex-Dock, OpenEye FRED, and Hermes GOLD were evaluated for their efficiency to reproduce known cognate inhibitors' conformations. Three metrics were used and compared to assess the performance of the applied scoring functions, i.e. enrichment factor, receiver operating characteristic (ROC) curves, and Bedroc analysis. Twelve different scoring functions of three softwares were used to assess their ability to rank the cognate ligand within the active site of its proteins. The extensive virtual screening task was performed on eight crystal structures, and the performance of docking and scoring was assessed by their ability to efficiently detect known active compounds enriched in the top-ranked of the list among a randomly selected dataset of the ten thousand compounds of the NCI database. The effectiveness of post-docking relaxation in Surflex was also evaluated. The top 20, 50, and 100 compounds were selected based on consensus scoring functions from all 48 proteins with different ligand complexes. Further, the shortlisted leads were subjected to ADMET via using Discovery Studio. The results further implicate the importance of various statistical tools that should be followed before large-scale virtual screening for the drug discovery process. In silico results demonstrating the experiment was successful. The study of the research covers the combinatorial in silico techniques such as benchmarking of the softwares and scoring functions, statistical tools applied for screening and different conformations of HIV-RT crystal structures for virtual screening with rigid and flexible molecular docking and molecular dynamics simulation approach. This study reveals a clear roadmap to identify novel scaffolds against HIV-RT for antiretroviral therapy, thus providing the remedial solutions of HIV related infections and other diseases caused by malfunctioning of the target protein.Communicated by Ramaswamy H. Sarma.

Predictors of Anti-TNF Therapy Failure among Inflammatory Bowel Disease (IBD) Patients in Saudi Arabia: A Single-Center Study.

BACKGROUND: The advent of monoclonal antibodies (mAbs) has revolutionized the management of many immune-mediated diseases such as inflammatory bowel disease (IBD). Infliximab and adalimumab were the first mAbs approved for the management of IBD, and are still commonly prescribed for the treatment of both Crohn's disease (CD) and ulcerative colitis (UC). Although mAbs have demonstrated high effectiveness rates in the management of IBD, some patients fail to respond adequately to mAbs, resulting in disease progression and the flare-up of symptoms. OBJECTIVE: The objective was to explore the predictors of treatment failure among IBD patients on infliximab (INF) and adalimumab (ADA)-as demonstrated via colonoscopy with a simple endoscopic score (SES-CD) of ≥1 for CD and a Mayo score of ≥2 for UC-and compare the rates of treatment failure among patients on those two mAbs. METHODS: This was a prospective cohort study among IBD patients aged 18 years and above who had not had any exposure to mAbs before. Those patients were followed after the initiation of biologic treatment with either INF or ADA until they were switched to another treatment due to failure of these mAbs in preventing the disease progression. Univariate and multiple logistic regressions were conducted to examine the predictors and rates of treatment failure. RESULTS: A total of 146 IBD patients (118 patients on INF and 28 on ADA) met the inclusion criteria and were included in the analysis. The mean age of the patients was 31 years, and most of them were males (59%) with CD (75%). About 27% and 26% of the patients had penetrating and non-stricturing-non-penetrating CD behavior, respectively. Patients with UC had significantly higher odds of treatment failure compared to their counterparts with CD (OR = 2.58, 95% CI [1.06-6.26], p = 0.035). Those with left-sided disease had significantly higher odds of treatment failure (OR = 4.28, 95% CI [1.42-12.81], p = 0.0094). Patients on ADA had higher odds of treatment failure in comparison to those on INF (OR = 26.91, 95% CI [7.75-93.39], p = 0.0001). CONCLUSION: Infliximab was shown to be more effective in the management of IBD, with lower incidence rates of treatment failure in comparison to adalimumab.

Effects of Smokeless Tobacco Samples from Tabuk Saudi Arabia on Nitric Oxide Production: A Potential Risk for Cancer and Cardiovascular Diseases.

BACKGROUND: Smokeless tobacco (SLT) is traditionally used in Middle East countries. The several toxic constituents with potential carcinogenicity make it a serious human health risk. Literature regarding their effects on cardiac and cancer disease is lacking in Saudi Arabia. OBJECTIVE: This study was conducted to investigate the adverse effect of 11 different samples of widely used SLT varieties from the Tabuk region - Saudi Arabia, on Nitric Oxide (NO) level and their potential risk on cardiovascular health, etiology and/or progression of cancers. METHODS: Samples were collected from Tabuk, KSA and analyzed by the GC-MS technique. Nitric oxide inhibition was performed using J774.2 macrophages by the Griess method. The retrieved crystallized structure of human inducible nitric oxide synthase (iNOS) from Brookhaven Protein Data Bank Repository PDB I.D: 3E7G with 2.20Å resolution was further prepared by structure using the MOE.2019 tool. The compounds abstracted from 11 different Shammah varieties were sketched by the MOE-Builder tool. Minimization for both receptor and compounds was performed via AMBER99 and MMFF99X force field implemented in MOE. RESULTS: Nine samples (4 - 11) showed a potent suppressive effect on NO production with IC50 values ranging between (16.9-20.4 µg/mL), respectively. The samples (1 & 2) exhibited a moderate level of inhibition with IC50 ranging between 33.2 and 57.4 µg/mL, respectively. Interestingly, sample 4 consisting of compounds (13-15, 19-26, 28) that mostly belongs to the group fatty acid ester and phthalic acid ester showed the most potent suppressive effect. Molecular docking results revealed that the current local SLT constituents presented noticeable potency in different extract samples. CONCLUSION: Variable suppressive effects on NO were detected in the current SLT samples, where sample 4 was the most potent among all. The extract of the latter exhibited molecular interaction with the first shell amino acid residues of Inducible nitric oxide synthase (iNOS), which may anchor the plasticity and selectivity of the compounds present in it. The samples (4 -11) showed a potent inhibitory effect on the NO, where compound 26 (Phthalic acid ester) is common, and its adequate concentration may account for augmented biological activity. These results may effectively highlight their adverse effects on cardiovascular health and etiology and/or progression of cancer and may help in strengthening the social and governmental efforts in minimizing the use of these substances.

A Case of Systemic Lupus Erythematosus Presenting as Pure Red Cell Aplasia.

Pure red cell aplasia (PRCA) is an uncommon condition, which is rarely associated with Systemic Lupus Erythematosus (SLE). Prompt identification and management of the underlying SLE results in correction of anemia. We report the case of a young female who presented due to severe anemia since the last two years. The cause of her anemia on initial investigations was not elicited in these two years, during which response to hematinics was poor and she remained transfusion dependent. Bone marrow biopsy showed PRCA after which autoimmune workup revealed SLE. Subsequently, treatment of SLE with steroids led to normalization of hemoglobin levels within a follow-up period of three months.

Structural insight into TNF-α inhibitors through combining pharmacophore-based virtual screening and molecular dynamic simulation.

Tumor Necrosis Factor-alpha (TNF-α), a multifunctional cytokine responsible for providing resistance against infections, inflammation, and cancers. TNF-α has emerged as a promising drug target against several autoimmune and inflammatory disorders. Several synthetic antibodies (Infliximab, Etanercept, and Adalimumab) are available, but their potential to cause severe side effects has prompted them to develop alternative small molecules-based therapies for inhibition of TNF-α. In the present study, combined in silico approaches based on pharmacophore modeling, virtual screening, molecular docking, and molecular dynamics studies were employed to understand significant direct interactions between TNF-α protein and small molecule inhibitors. Initially, four different small molecule libraries (∼17.5 million molecules) were virtually screened against the selected pharmacophore model. The identified hits were further subjected to molecular docking studies. The three potent lead compounds (ZINC05848961, ZINC09402309, ZINC04502991) were further subjected to 100 ns molecular dynamic studies to examine their stability. Our docking and molecular dynamic analysis revealed that the selected lead compounds target the TNF receptor (TNFR) and efficiently block the production of TNF. Moreover, in silico ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) analysis revealed that all the predicted compounds have good pharmacokinetic properties with high gastrointestinal absorption and a decent bioavailability score. Furthermore, toxicity profiles further evidenced that these compounds have no risk of being mutagenic, tumorigenic, reproductive and irritant except ZINC11915498. In conclusion, the present study could serve as the starting point to develop new therapeutic regimens to treat various TNF- related diseases. Communicated by Ramaswamy H. Sarma.

Exploring the Molecular Mechanisms of 17ß-HSD5-induced Carcinogenicity of Catha edulis via Molecular Modeling Approach.

BACKGROUND: The tradition of khat chewing has been deep-rooted in the African and Arabian Peninsula for centuries. Due to its amphetamine-like psycho-stimulant or euphoric effect, khat has been used by millions in Somalia, Ethiopia, Saudi Arabia and Yemen. The long-term use of khat can induce many major health outcomes, which may be serious and irreversible. OBJECTIVE: Prolonged use of khat constituents has been associated with different types of cancers such as prostatic, breast and ovarian cancer. However, it has been very difficult to identify the molecular targets involved in khat carcinogenesis that interact with the Khat constituents by in vitro/in vivo experimental tools. METHODS: In silico tools were used to predict potential targets involved in the carcinogenesis of khat. Pass on-line prediction server was used for the prediction of a potential molecular target for khat constituents. Molecular Dynamics simulation and MM-GBSA calculation of the predicted target were carried out. RESULTS: Molecular Dynamics simulation and MM-GBSA calculation revealed that among khat constituents, ß-sitosterol showed a high binding affinity towards 17ß-HSD5. On the other hand, this study highlights for the first time some new interactions, which were observed in the case of cathine, cathinone and nerol during the simulation. CONCLUSION: In silico molecular dynamic simulation tools were used for the first time to investigate the molecular mechanism of widely used leaves of psychoactive khat (Catha edulis) constituent. The present study provides deep insight to understand the effect of khat constituents involved in the impairment of the reproductive system and its binding to 17ß-HSD5. ADMET profiling also suggested that few khat constituents do not fulfill the requirements of the Lipinski rule of five i.e. poor absorption and blood-brain barrier impermeability.

Pharmacophore model-based virtual screening, docking, biological evaluation and molecular dynamics simulations for inhibitors discovery against α-tryptophan synthase from Mycobacterium tuberculosis.

Discovery of new anti-tuberculosis drugs with novel mode of action is urgently needed. The tryptophan synthase is a genetically validated enzyme that catalyzes last step of tryptophan biosynthetic pathway required for growth and survival of Mycobacterium tuberculosis. Here, a ligand-based pharmacophore model was built using molecular operating environment (MOE) software (version 2010.12) and validation of generated pharmacophoric features was done using active, inactive and decoy set of molecules. The generated pharmacophore model was used for screening of 7,523,972 drug-like molecules of ZINC database. The best matches (RMSD < 1) retrieved as a result of screening were subjected to molecular docking studies into active pocket of α-subunit of tryptophan synthase from M. tuberculosis. The five hits were selected and validated through anti-tuberculosis activity analysis. Finally, a new inhibitor ZINC09150898 has been identified with best binding score -32.07 kcal/mol, showing 100% growth inhibition of M. tuberculosis (H37Rv strain) at 50 µg/mL. This identified inhibitor-protein complex was further subjected to MD simulations studies (50 ns) involving root mean square deviation, root mean square fluctuation, secondary structure analysis and pocket interaction analysis to explore its binding mode stability inside active pocket. The binding free energies of inhibitor-protein complex through MM-PBSA analysis suggested that van der Waals interactions play a vital role for retention of identified inhibitor inside the protein pocket. All these analyses confirmed retention of ligand inside pocket and no unfolding in protein structure was observed over explored time scale.Communicated by Ramaswamy H. Sarma.

Early hematological indicators of severe COVID-19 disease in hospitalized patients: Data from a South Asian population.

INTRODUCTION: Outbreak of corona virus disease in 2019 (COVID-19) has resulted in significant morbidity and mortality worldwide. Our aim is to document hematological parameters of patients with COVID-19 during initial stage of diagnosis and to identify early hematological indicators of severe infection. MATERIALS AND METHODS: This retrospective study was conducted at Shifa International Hospital, Pakistan from April to November 2020. Patients hospitalized with COVID-19, diagnosed on RT-PCR and had a complete blood count (CBC) done within 48 hours of diagnosis were included. Data was analyzed using IBM® SPSS Statistics. RESULTS: A total of 425 patients were included in this study out of whom 272(64%) were males. The mean age was 55.61 ± 17.84 years. 95 patients (22.4%) had normal blood counts within 48 hours of COVID-19 diagnosis. Cytopenias were seen in 193(45.4%) patients. There were 75(17.6%) mortalities during the study period. Chi-square test showed that thrombocytopenia, lymphopenia and neutrophilic leucocytosis were significantly associated with mortality (P = .037, P < .001, P < .001 respectively) and need for ventilator (P = .009, P < .001, P < .001, respectively). Neutrophilia was also associated with development of Acute Respiratory Distress Syndrome (P < .001). On ROC analysis, Neutrophil-to-Lymphocyte Ratio yielded an area under the curve (AUC) of 0.693 and 0.660 for the outcomes mortality and need for ventilator, respectively. For a subset of 288 patients who had D-dimer levels checked within 48 hours of COVID-19 diagnosis, the AUC for mortality and ventilator need was 0.708 and 0.671, respectively. CONCLUSION: Hematological indices are vital indicators in the prognosis and risk stratification of COVID-19 during initial stages of disease.