Fabrication and characterization of binary composite MgO/CuO nanostructures for the efficient photocatalytic ability to eliminate organic contaminants: A detailed spectroscopic analysis

Design and eco-friendly fabrication of affordable and sustainable materials for the treatment of wastewater consisting of dyes, antibiotics, and other harmful substances has always been demanding. Untreated wastewater being released from industries imposes serious threats to our ecosystem, seeking convenient approaches to diminish this alarming issue. Here in this work, we synthesized MgO/CuO nanocomposites from a plant extract of Ammi visnaga L. and then employed these nanocomposites for the treatment of organic dye (methylene blue). We characterized the synthesized nanocomposites by dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), x-ray diffraction (XRD), and X-ray photoelectron microscopy (XPS). DLS presented information about the explicit size of nanocomposites, while the surface charge was examined by zeta potential. XRD provided detailed information about the crystalline behavior and the information regarding surface morphology and size was extracted by SEM, TEM, and AFM. Moreover, the fabricated nanocomposites were used as a photocatalyst in the treatment of methylene blue. The overall catalytic reaction took an hour to complete, and the value of percentage degradation was 98 %. Substantially, a detailed account of the kinetics, rate of reaction, and mechanism is also fostered in the context. The presented study can assist scientists and researchers around the world to reproduce the results and use them to apply them on a broader scale.

Unraveling the mechanisms of Sofosbuvir resistance in HCV NS3/4A protease: Structural and molecular simulation-based insights

Current management of HCV infection is based on Direct-Acting Antiviral Drugs (DAAs). However, resistance-associated mutations, especially in the NS3 and NS5B regions are gradually decreasing the efficacy of DAAs. Among the most effective HCV NS3/4A protease drugs, Sofosbuvir also develops resistance due to mutations in the NS3 and NS5B regions. Four mutations at positions A156Y, L36P, Q41H, and Q80K are classified as high-level resistance mutations. The resistance mechanism of HCV NS3/4A protease toward Sofosbuvir caused by these mutations is still unclear, as there is less information available regarding the structural and functional effects of the mutations against Sofosbuvir. In this work, we combined molecular dynamics simulation, molecular mechanics/Generalized-Born surface area calculation, principal component analysis, and free energy landscape analysis to explore the resistance mechanism of HCV NS3/4A protease due to these mutations, as well as compare interaction changes in wild-type. Subsequently, we identified that the mutant form of HCV NS3/4A protease affects the activity of Sofosbuvir. In this study, the resistance mechanism of Sofosbuvir at the atomic level is proposed. The proposed drug-resistance mechanism will provide valuable guidance for the design of HCV drugs.

Identification of IL-2 inducible tyrosine kinase inhibitors by quantum mechanics and ligand based virtual screening approaches

Interleukin-2-inducible T-cell kinase (ITK) is a crucial intracellular signaling mediator in normal and malignant T-cells and natural killer cells. Selective inhibition of ITK might be useful for treating a variety of disorders including; autoimmune, inflammatory, and neoplastic disorders. Over the past two decades, the clinical management of ITK inhibitors has progressed dramatically. So far, specific inhibitor with no off-target effects against ITK is available. Herein, we aim to discover potential virtual hits to fasten the process of drug design and development against ITK. In this regard, the key chemical characteristics of ITK inhibitors were identified using ligand-based pharmacophore modeling. The validated pharmacophore comprises one hydrogen bond donor and three hydrogen bond acceptors and was utilized as a 3D query in virtual screening using ZINC, Covalent, and in-house databases. A total of 12 hit compounds were chosen on the basis of their critical interactions with the significant amino acids of ITK. The orbital energies such as HOMO and LUMO of the hit compounds were calculated to evaluate the inhibitor's potencies. Further, molecular dynamics simulation demonstrated the stability of ITK upon binding of selected virtual hits. Binding energy using the MMGBSA method showed the potential binding affinity of all the hits with ITK. The research identifies key chemical characteristics with geometric restrictions that lead to ITK inhibition.Communicated by Ramaswamy H. Sarma.

Exploring bi-carbazole-linked triazoles as inhibitors of prolyl endo peptidase via integrated in vitro and in silico study

A serine protease called prolyl endopeptidase (PEP) hydrolyses the peptide bonds on the carboxy side of the proline ring. The excessive PEP expression in brain results in neurodegenerative illnesses like dementia, Alzheimer's disease, and Parkinson's disease. Results of the prior studies on antioxidant activity, and the non-cytotoxic effect of bi-carbazole-linked triazoles, encouraged us to extend our studies towards its anti-diabetic potential. Hence, for this purpose all compounds 1-9 were evaluated to reveal their anti-prolyl endo peptidase activity. Fortunately, seven compounds resulted into significant inhibitory capability ranging from 26 to 63 µM. Among them six compounds 4-9 exhibited more potent inhibitory activity with IC50 values 46.10 ± 1.16, 42.30 ± 1.18, 37.14 ± 1.21, 26.29 ± 0.76, 28.31 ± 0.64 and 31.11 ± 0.84 µM respectively, while compound 3 was the least active compound in the series with IC50 value 63.10 ± 1.58 µM comparing with standard PEP inhibitor bacitracin (IC50 = 125 ± 1.50 µM). Moreover, mechanistic study was performed for the most active compounds 7 and 8 with Ki values 24.10 ± 0.0076 and 23.67 ± 0.0084 µM respectively. Further, the in silico studies suggested that the compounds exhibited potential interactions and significant molecular conformations, thereby elucidating the structural basis for their inhibitory effects.

Refining shape and size of silver nanoparticles using ion irradiation for enhanced and homogeneous SERS activity

We present green synthesis of silver nanoparticles in water using unirradiated and Ag15 + ion irradiated phytoextracts of Bergenia Ciliata leaf, Eupatorium adenophorum leaf, Rhododendron arboreum leaf and flower. The use of different plant extracts and their subsequent ion irradiation allow for successful refinement of nanoparticle size and morphology. Due to changes in reducing and capping agents the nanoparticle surface functionalization also varies which not only controls the morphology but also allows for surface oxidation and aggregation processes. In this work, we have synthesized silver nanoparticles which exhibit sizes in the range from 13 to 24 nm and having shapes like spherical, quasispherical, trigonal, hexagonal, cylindrical, dendritic assemblies, and porous nanoparticles. Owing to changes in the size and shape of the nanoparticles, their direct bandgap (2.05 eV - 2.48 eV) and local surface plasmon resonance (420 nm - 490 nm) could also be tuned. These nanoparticles are examined as SERS substrates, where their enhancement factors, limit of detection for methylene blue, and SERS substrate homogeneity have been tested. It has been observed the nanoparticles synthesized using unirradiated plant extracts present an enhancement factor of 106 with a limit of detection 10- 8 M. Whereas nanoparticles with refined morphology and shapes upon irradiation present high enhancement factors of >107 and detection limit down to 10- 9 M. In addition, uniformity in Raman spectra over the SERS substrates has been obtained for selected Ag NPs substrates synthesized using irradiated extracts with minimum relative standard deviation in enhancement factor < 12%.

Plummeting toxic contaminates from water through phycoremediation: Mechanism, influencing factors and future outlook to enhance the capacity of living and non-living algae

Freshwater habitats hold a unique role in the survival of all living organisms and supply water for drinking, irrigation, and life support activities. In recent decades, due to anthropogenic activities, deterioration in the water quality has been a long-lasting problem and challenge to the scientific fraternity. Although, these freshwater bodies have a bearable intrinsic capacity for pollution load however alarming increase in pollution limits the intrinsic capacities and requires additional technological interventions. The release of secondary pollutants from conventional interventions further needs revisiting the existing methodologies and asking for green interventions. Green interventions such as phycoremediation are natural, eco-friendly, economic, and energy-efficient alternatives and provide additional benefits such as nutrient recovery, biofuel production, and valuable secondary metabolites from polluted freshwater bodies. This systemic review in a nut-shell comprises the recent research insights on phycoremediation, technological implications, and influencing factors, and further discusses the associated mechanisms of metal ions biosorption by living and non-living algae, its advantages, and limitations. Besides, the article explores the possibility of future research prospects for applicability at a field scale that will help in the efficient utilization of resources, and improved ecological and health risks.

Impact of nonmalignant ascites on outcomes of open inguinal hernia repair in the USA

PURPOSE

Studies on inguinal hernia repair in patients with ascites are limited, small, and inconsistent, exacerbating a challenging clinical dilemma for surgeons. To fill this gap in the literature, this retrospective cohort study used a national US database to examine the impact of ascites on the outcomes of open inguinal herniorrhaphy.

METHODS

Patients who underwent open inguinal herniorrhaphy between 2005 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Two groups were defined by the presence or absence of nonmalignant preoperative ascites. Ascites patients were propensity matched 1:10 with non-ascites patients. Surgical outcomes at 30 days for the matched groups, stratified by electiveness of procedure, were compared, with the primary end points of mortality and the NSQIP composite outcome "serious complication".

RESULTS

The study included 682 patients with ascites. Compared to matched controls, those with ascites had significantly increased odds of mortality (OR 3.3, 95% CI 1.5-7.0) after elective repair, but not after nonelective repair. Ascites was associated with increased odds of serious complication after both elective (OR 1.7, 1.2-2.3) and nonelective (OR 2.0, 1.3-3.0) surgery. Among ascites patients, age ≥ 65 years was associated with increased mortality (risk-adjusted OR 3.8, 1.2-14.4) and serious complication (OR 2.2, 1.2-3.9).

CONCLUSION

In this largest study to date on patients with ascites undergoing open inguinal herniorrhaphy, ascites increased the odds of mortality after elective repair and of serious complication after elective and nonelective repair. Age ≥ 65 was a risk factor for poor outcome. Inguinal herniorrhaphy is fraught with complications in this population.

Hemagglutinin 3 and 8 can be the most efficient influenza subtypes for human host invasion; a comparative in silico approach

The severity of the influenza virus infection is largely determined by its ability to invade the human host receptor. This critical step is conducted by utilizing hemagglutinin (HA) due to its binding with sialic acid 2,6 (SA). Though 18 subtypes (H1-H18) of HA have been identified, the most efficient one for conducting the host entry has not yet been resolved. This study aims to assess the severity of infections for HA variants by conducting a comparative docking of H1-H18 with the human SA receptor. Eighteen viral 3D structures were retrieved, minimized, and optimized for docking with human SA. In all retrieved structures, five conserved amino acid residues were selected for docking with human SA. Special protein grids were prepared by locating these five residues in the 18 selected subtypes. Results showed that H3 and H8 exerted the highest standard precision and extra precision docking scores, and the highest binding affinities with the human SA, respectively. Phylogenetic analyses confirmed the actual positioning of the selected 3D structures and showed these docked structures belonged to their usual classes due to the extremely close distances found in each docked subtype compared with its corresponding non-docked structures. H8-SA showed slightly better RMSD and SASA values than H3-SA, while H3-SIA showed more favourable radius of gyration scores than H8-SIA in the majority of the simulation period. Due to the highest affinity of binding of H3 and H8 with the human receptor, special caution should be exercised regarding any possible outbreak mediated by these subtypes in human populations. However, it is important to acknowledge a limitation inherent to the computational approach; it may hold relative rather than absolute significance. Further research is needed to deepen our understanding of the intricate interplay between HA variants and the host receptor, taking into account the broader context of viral infection dynamics.Communicated by Ramaswamy H. Sarma.

Design of a novel multiple epitope-based vaccine: an immunoinformatics approach to combat monkeypox

Monkeypox virus is an infectious agent that causes fever, Pneumonitis encephalitis, rash, lymphadenopathy and bacterial infection. The current outbreak of monkeypox has reawakened the global health concern. In the current situation of increasing viral infection, no vaccine or drug is available for monkeypox. Thus, there is an urgent need for viable vaccine development to prevent viral transmission by boosting human immunity. Herein, using immunoinformatics approaches, a multi-epitope vaccine was constructed for the Monkeypox virus. In this connection, B-Cell and T-cell epitopes were identified and joined with the help of adjutants and linkers. The vaccine construct was selected based on promising vaccine candidates and immunogenic potential. Further epitopes were selected based on antigenicity score, non-allergenicity and good immunological properties. Molecular docking reveals strong interactions between TLR-9 and the predicted vaccine construct. Finally, molecular dynamics simulations were performed to evaluate the stability and compactness of the constructed vaccine. The MD simulation results demonstrated the significant stability of the polypeptide vaccine construct. The predicted vaccine represented good stability, expression, immunostimulatory capabilities and significant solubility. Design vaccine was verified as efficient in different computer-based immune response investigations. Additionally, the constructed vaccine also represents a good population coverage in computer base analysis.Communicated by Ramaswamy H. Sarma.

Masoprocol: a promising candidate for targeting insulin resistance by inhibiting resistin with optimal druglikeness Potentials: an in silico approach

Resistin is a cysteine-rich secretory hormone that induces resistance to insulin, and its elevated expression is correlated with the onset of diabetes and several related metabolic disorders. Resistin performs its inhibitory role by connecting three identical subunits through Cys22-based disulfide linkages. The necessity to inhibit the formation of resistin trimer is one of the essential means to prevent the aggravation of diabetes mellitus type 2, obesity, and atherosclerosis. This study was conducted to screen the clinically approved drugs to find the most potent one to inhibit resistin with the best pharmacokinetics and drug-likeness properties. A total of 4654 clinically approved drugs were docked against the Cys22 residue of resistin. The top ten drugs with the highest high-precision (XP) docking scores were selected. Ioversol and masoprocol showed the highest XP docking and Molecular Mechanics-Generalized Born Surface Area (MMGBSA) scores, respectively, with double hydrogen bonding with the targeted Cys22. Molecular dynamics (MD) simulations showed that the masoprocol-resistin complex exhibited lower root mean square deviation (RMSD), radius of gyration, and root mean square fluctuation (RMSF) values than those observed in the ioversol-resistin complex. Both drugs induced drastic conformational changes in resistin monomer interactions. However, ioversol did not prove satisfying drug-likeness properties, while masoprocol showed the most favourable pharmacokinetic and drug-likeness properties. This study has demonstrated that masoprocol offers a novel inhibitory effect on resistin with the highest ligand affinity, making it a promising drug for combating insulin resistance.Communicated by Ramaswamy H. Sarma.

Effects of long-term Ailanthus altissima extract supplementation on fear, cognition and brain antioxidant levels

Introduction

Ailanthus altissima is an indigenous plant known for various remedial properties. The present study aimed to evaluate the neuroprotective potential of methanolic extract Ailanthus altissima (AA) bark as current scientific trend is searching plant for neurodegenerative diseases, worldwide.

Methodology

In in-vitro experiments, the AA was analyzed for phenols, flavonoids, antioxidative and cholinesterase inhibitory properties with subsequent detailed characterization for secondary metabolites. The in-vivo neurological effects were evaluated in rats through behavioral assessment for anxiety and memory after chronic administration (28 days) of 50-200 mg/kg of AA. At the end of behavior studies, isolated brains were biochemically tested to determine antioxidant enzyme activity.

Results

AA was found rich in phenols/flavonoids and active in radical scavenging with the presence of 13 secondary metabolites in UHPLC-MS analysis. The AA yielded anxiolytic effects dose-dependently in the open field, light/dark and elevated-plus maze tests as animals significantly (P < 0.05 vs control group) preferred open arena, illuminated zone and exposed arms of maze. Similarly, the animals treated with AA showed significant (P < 0.05 vs amnesic group) increase in spontaneous alternation, discrimination index in y-maze, novel object recognition tests. Further, AA.Cr treated rats showed noticeably shorter escape latencies in Morris water maze tests.In biochemical analysis, the dissected brains AA treated rats showed reduced levels of AChE and malondialdehyde with increased levels of first-line antioxidant enzymes i.e. glutathione peroxidase and superoxide dismutase. These observed biological effects might be attributed to phenols and flavonoids constituents owned by AA. -The in-silico studies showed thatconessine and lophirone J phytocompounds have good blood-brain barrier permeability and interaction with AChE.

Conclusion

The outcomes of this study validate that bark of Ailanthus altissima might work as a source of bioactive phytochemicals of neuroprotective potential.

Theoretical investigation of selective ligand binding mode of galanin receptors

The Galaninergic system consist of Galanin and its receptors, involved in neuromodulation and neurotransmission. Galanin regulate its physiologic and pathologic functions by interacting with three G-protein coupled receptors; GalR1, GalR2 and GalR3. The widespread distribution of Galanin and its receptor subtypes in central and peripheral nervous system makes them an attractive drug target for the treatment of neurological diseases. However, subtypes selective ligands paucity and little structural information related to either Galanin receptors and Galanin receptor-ligand complexes hampered the structure-based drug design. Thus computational modeling characterization strategy was utilized for Galanin receptor 3D structure prediction and subtypes ligands binding selectivity. Reported ligands with experimental activity were docked against the homology model of Galanin receptors. Further, the MD simulation and binding free energy calculation were carried out to determine the binding interactions pattern consistency and selectivity towards receptor subtype. Results of binding free energy of per residue indicate key contribution of GalR1 Phe115 and His267 in the selective binding of ligands while Tyr103, Tyr270 and His277 play major role in the selective binding of GalR3 ligands. Our study provide rationale for further in silico virtual screening of small molecules for the development of selective ligands against Galanin receptor subtypes.Communicated by Ramaswamy H. Sarma.

Cheminformatics-Based Discovery of Potential Chemical Probe Inhibitors of Omicron Spike Protein

During the past two decades, the world has witnessed the emergence of various SARS-CoV-2 variants with distinct mutational profiles influencing the global health, economy, and clinical aspects of the COVID-19 pandemic. These variants or mutants have raised major concerns regarding the protection provided by neutralizing monoclonal antibodies and vaccination, rates of virus transmission, and/or the risk of reinfection. The newly emerged Omicron, a genetically distinct lineage of SARS-CoV-2, continues its spread in the face of rising vaccine-induced immunity while maintaining its replication fitness. Efforts have been made to improve the therapeutic interventions and the FDA has issued Emergency Use Authorization for a few monoclonal antibodies and drug treatments for COVID-19. However, the current situation of rapidly spreading Omicron and its lineages demands the need for effective therapeutic interventions to reduce the COVID-19 pandemic. Several experimental studies have indicated that the FDA-approved monoclonal antibodies are less effective than antiviral drugs against the Omicron variant. Thus, in this study, we aim to identify antiviral compounds against the Spike protein of Omicron, which binds to the human angiotensin-converting enzyme 2 (ACE2) receptor and facilitates virus invasion. Initially, docking-based virtual screening of the in-house database was performed to extract the potential hit compounds against the Spike protein. The obtained hits were optimized by DFT calculations to determine the electronic properties and molecular reactivity of the compounds. Further, MD simulation studies were carried out to evaluate the dynamics of protein–ligand interactions at an atomistic level in a time-dependent manner. Collectively, five compounds (AKS-01, AKS-02, AKS-03, AKS-04, and AKS-05) with diverse scaffolds were identified as potential hits against the Spike protein of Omicron. Our study paves the way for further in vitro and in vivo studies.

A first principles study of a van der Waals heterostructure based on MS2 (M = Mo, W) and Janus CrSSe monolayers

The strategy of stacking two-dimensional materials for designing van der Waals heterostructures has gained tremendous attention in realizing innovative device applications in optoelectronics and renewable energy sources. Here, we performed the first principles calculations of the geometry, optoelectronic and photocatalytic performance of MS₂-CrSSe (M = Mo, W) vdW heterostructures. The mirror asymmetry in the Janus CrSSe system allows the designing of two models of the MS₂-CrSSe system by replacing S/Se atoms at opposite surfaces in CrSSe. The feasible configurations of both models of the MS₂-CrSSe system are found energetically, dynamically and thermally stable. The studied heterobilayers possess an indirect type-I band alignment, indicating that the recombination of photogenerated electrons and holes in the CrSSe monolayer is hence crucial for photodetectors and laser applications. Remarkably, a red-shift in the optical absorption spectra of MS₂-CrSSe makes them potential candidates for light harvesting applications. More interestingly, all heterobilayers (except W(Mo)S₂-CrSSe of model-I(II)) reveal appropriate band edge positions of the oxidation and reduction potentials of the photocatalysis of water dissociation into H⁺/H₂ and O₂/H₂O at pH = 0. These results shed light on the practical design of the MS₂-CrSSe system for efficient optoelectronic and photocatalytic water splitting applications.

Deciphering the Impact of Mutations on the Binding Efficacy of SARS-CoV-2 Omicron and Delta Variants With Human ACE2 Receptor

The pandemic of COVID-19, caused by SARS-CoV-2, has globally affected the human health and economy. Since the emergence of the novel coronavirus SARS-CoV-2, the life-threatening virus continues to mutate and evolve. Irrespective of acquired natural immunity and vaccine-induced immunity, the emerging multiple variants are growing exponentially, crossing the territorial barriers of the modern world. The rapid emergence of SARS-CoV-2 multiple variants challenges global researchers regarding the efficacy of available vaccines and variant transmissibility. SARS-CoV-2 surface-anchored S-protein recognizes and interacts with the host-cell ACE2, facilitating viral adherence and entrance into the cell. Understanding the interfacial interactions between the spike protein of SARS-CoV-2 variants and human ACE2 receptor is important for the design and development of antiviral therapeutics against SARS-CoV-2 emerging variants. Despite extensive research, the crucial determinants related to the molecular interactions between the spike protein of SARS-CoV-2 variants and host receptors are poorly understood. Thus, in this study, we explore the comparative interfacial binding pattern of SARS-CoV-2 spike RBD of wild type, Delta, and Omicron with the human ACE2 receptor to determine the crucial determinants at the atomistic level, using MD simulation and MM/GBSA energy calculations. Based on our findings, the substitution of Q493R, G496S, Q498R, and Y505H induced internal conformational changes in Omicron spike RBD, which leads to higher binding affinity than Delta spike RBD with the human ACE2 receptor, eventually contributing to higher transmission and infectivity. Taken together, these results could be used for the structure-based design of effective antiviral therapeutics against SARS-CoV-2 variants.

Variability in indigenous Pakistani tomato lines and worldwide reference collection for Tomato Mosaic Virus (ToMV) and Tomato Yellow Leaf Curl Virus (TYLCV) infection

Local and exotic germplasm of tomato remains a major source for genetic improvement. Assessment of such lines for biotic stresses particularly viral diseases are the most important criteria for selection in Pakistan, where Tomato Yellow Leaf Curl Virus (TYLCV) and Tomato Mosaic Virus (ToMV) are the major diseases/viruses. A set of 40 accessions (including indigenous Pakistani lines and exotic germplasm from Europe, the United States, and Asia) were evaluated for their resistance/infection response to ToMV with artificial inoculation under greenhouse conditions. Infection response was quantified through disease scoring and DAS-ELISA test (for ToMV). A subset of 24 lines, was further screened for TYLCV using disease scoring and TAS-ELISA. The tested lines showed significant variability for resistance to ToMV. Only one accession (Acc-17878) was resistant to the ToMV whereas seven accessions i.e. Acc-17890, AVR-261, CLN-312, AVR-321, EUR-333, CLN-352, and CLN-362 expressed resistance to TYLCV. Correlation between phenotypic evaluation was confirmed by the ELISA results in both diseases, although both tools complemented to assess the viral infection status. In future, tomato breeding programs must consider breeding for ToMV and TYLCV resistance (using identified germplasm in our study) so as to deliver virus resistant tomato varieties.

Effect of Agaricus blazei Murill on exploratory behavior of mice-model

Increased anxiety and depressive symptoms have reported to be its association with long term illness. Because of having unwanted effects of newly available drugs, patients administering anxiolytic drugs usually discontinue the treatment before they are completely recovered. Therefore, there is a serious need to develop new anxiolytic drugs. The anxiolytic effect of hydro-alcoholic extract of Agaricus blazei in animal models was assessed. 24 male mice (Mus musculus genus) were included in the study. Four groups were prepared and each group contained six animals. The groups were vehicle control, positive control (diazepam 1.0 mg/kg, i.p.) as well as two treatment groups receiving Agaricus blazei hydro-alcoholic extract at a dose of 136.50 mg/kg and 273.0 mg/kg orally. The Marble burying test, Nestlet shredding test and Light and Dark box test used to assess anxiolytic activity. Mice administered with diazepam 1.0 mg/kg, i.p. while hydro-alcoholic extract of AbM (136.50 and 273.0 mg/kg, respectively) was administered via oral route which exhibited marked reduction in number of marbles-burying as compared to vehicle control group. Mice administered with diazepam 1.0 mg/kg, i.p. and Oral administration of hydro-alcoholic extract of AbM (136.50 and 273.0 mg/kg, respectively) exhibited significant decrease in nestlet shredding in comparison to vehicle control group. The oral administration of hydro-alcoholic extract at a dose of 136.5mg/kg and 273mg/kg showed elevation in time spent in light box and was comparable to standard treated group while time spent by mice following oral administration of hydro-alcoholic extract of Agaricus blazei at a dose of 273.0 mg/kg also showed elevation and was found to be more near to standard treated group (diazepam 1 mg/kg, i.p.).

Can a virtual microbiology simulation be as effective as the traditional Wetlab for pharmacy student education?

BACKGROUND

Pharmacy practice education requires the development of proficiencies and an understanding of clinical microbiology. Learning in this area could be delivered using practical laboratory exercises, or potentially, simulation-based education. Simulation has previously successfully enhanced learning in health professional education. The current global climate due to COVID-19 has further highlighted the important role of technology-enhanced learning in delivering outcomes that meet the requisite learning objectives of a course. The aim of the present study was to compare the impact of a commercially available virtual microbiology simulation (VUMIE™) with a traditional wet laboratory (wetlab) on learner knowledge, skills and confidence in a second-year integrated pharmacotherapeutics course for Bachelor of Pharmacy students.

METHODS

A randomised, crossover study was employed to determine whether the simulation intervention (VUMIE™) improves learning outcomes (knowledge, skills and confidence) of pharmacy students, when compared to a traditional wetlab intervention. Each student completed three 1-2 h length sessions, for both the wetlab and VUMIE™ interventions (6 sessions total). Data was collected using surveys deployed at baseline (pre-interventions), post-intervention 1 or 2 (VUMIE™ or wetlab) and endpoint (post-interventions 1 and 2). Statistical analysis was conducted using SPSS Statistics 25 and Instat™ software.

RESULTS

Response rates were approximately 50% at initial survey and approximately 25% at endpoint survey. VUMIE™ produced higher post-intervention knowledge scores for the multiple-choice questions compared to the wetlab, however, the highest score was achieved at endpoint. Both interventions produced statistically significant differences for mean scores compared to baseline (pre-VUMIE™ and wetlab) across the domains of knowledge, skills and confidence. VUMIE™ produced higher post-intervention mean scores for knowledge, skills and confidence compared to post-intervention mean scores for the wetlab, however there was no statistical significance between the mean score for the two interventions, thus the VUMIE™ activity produced learning outcomes comparable to the wetlab activity.

CONCLUSION

These findings suggest VUMIE™ provides similar effects on students' knowledge, skills, and confidence as a wetlab. The simulation's implementation was not cost-prohibitive, provided students with a physically and psychologically safe learning environment, and the benefit of being able to repeat activities, supporting deliberate practice.

Body composition, growth performance and enzyme activities of Labeo rohita fed different commercial fish feeds

We have evaluated the effects of different fish feeds on the body composition, growth, and enzyme activities of Labeo rohita (Rohu). In total, 240 fishes between the average weights of 24.77±2.15g were studied. The treatments were applied in a completely randomized design, with 4 treatments of 60 fishes each. Treatments consisted of four different fish feeds [Oryza (T1), AMG (T2), Aqua (T3), and Supreme (T4)]. Body composition, growth performance, and enzyme activities were evaluated. There was a significant variation in performance of fishes fed with different type of feed; as fishes having Oryza feed showed the highest weight gain, specific growth rate (SGR), and best feed conversion ratio (FCR) as compared to other groups that were considered to be significant (P ≤ 0.05). High net weight gain was obtained in T4 when compared with T2 and T3. FCR value of T4 was less than T1 but higher than T2, T3 and T2, which showed the lowest values. The specific growth rate was recorded as average in T4, but T2 led a high SGR than T3. Similarly, crude protein level and digestive enzymes activity was recorded significantly highest in fed with Oryza (T1) as compared to AMG (T2), Aqua (T3), and Supreme (T4). Water quality parameters were recorded significant in all treatments except pH and DO of treatment (T1), significantly different from other treatments. It was concluded that Rohu (Labeo rohita) could show a promising growth rate and protease enzyme activity when fed with the Oryza feed of 25% protein.

Role of Intraperitoneal Normal Saline Instillation in Relieving Post-operative Pain Following Laparoscopic Cholecystectomy: A Quasi Experimental Study

Laparoscopic cholecystectomy has rapidly become the procedure of choice for the treatment of calculus cholecystitis for having clear advantage over open method in reducing surgical morbidity, postoperative pain and complication. But still patients undergoing laparoscopic cholecystectomy complain of considerable pain especially on first post-operative day necessitating use of better methods for postoperative analgesia. This quasi experimental study was done in Surgery Unit III, Mymensingh Medical College Hospital from July 2016 to June 2017 to assess the role of intraperitoneal normal saline instillation following laparoscopic cholecystectomy in relieving postoperative pain. In this study total 200 patients of calculus cholecystitis were enrolled according to inclusion and exclusion criteria and assigned equally into two groups by non-equivalent control group design. Both the control group and experimental group were managed according to the standard protocol and operated in routine operation theater. The experimental group (n=100) was additionally instilled with 25-30ml/kg body weight of normal saline at 37°C at the gallbladder bed and subdiaphragmatic space at the end of surgery and all the data were recorded in individual case record form. Among the sample most of the patients were between 25-60 years of ages with the peak age being between 43-51 years. Eighty one percent (81%) of the total patients were female with male female ratio being 1:5.25 in Control group and 1:3.54 in Experimental group. The VAS scores for visceral pain in experimental group were significantly less than that of control group at 6 hours (p<0.001), 12 hours (p<0.001), 24 hours (p<0.001) and 48 hours (p=0.026). The VAS scores for shoulder tip pain in experimental group were also significantly less than that of control group at 6 hours (p<0.001), 12 hours (p<0.018) and 24 hours (p=0.004). The administration of analgesics was also significantly less in the experimental group than in control group at 6 hours (p<0.001), 12 hours (p<0.001), 24 hours (p=0.313) and 48 hours (p=0.297) with no significant differences at 72 hours. The mean hospital stay in this study was 2.2±0.7 days in the control group and 2.1±0.8 days in the experimental group showing no significant difference (p>0.05). Intraperitoneal normal saline instillation following laparoscopic cholecystectomy may be an eminent choice for reducing postoperative pain improving patient's experience.

Genotyping for Dombrock blood group alleles in Northern Pakistani blood donors

Genotyping can be used to identify rare blood group antigens and to solve suspected blood group discrepancies, particularly when serologic methods are limited. Unfortunately, only a few such studies have been performed in Pakistan. The present study was conducted to determine the frequency of Dombrock blood group alleles by genotyping samples from blood donors from the north of Pakistan. Blood samples were taken with consent from 300 blood donors; DNA was extracted and tested for DO*01 and DO*02 alleles by sequence-specific primer polymerase chain reaction (PCR-SSP), followed by gel electrophoresis. Allele frequencies were calculated. The observed and expected genotype frequencies were compared using the χ² test. The allele frequencies for DO*01 and DO*02 were 0.40 and 0.60, respectively. Genotype frequencies were in Hardy-Weinberg equilibrium. This study in Pakistani blood donors provides Dombrock blood group allele frequencies by PCR-SSP. This approach is efficient and economical and can be applied in developing countries. The findings can contribute to the development of in-house red blood cell panels, identification of rare blood types, and establishment of a national rare blood donor program.

Genotyping can be used to identify rare blood group antigens and to solve suspected blood group discrepancies, particularly when serologic methods are limited. Unfortunately, only a few such studies have been performed in Pakistan. The present study was conducted to determine the frequency of Dombrock blood group alleles by genotyping samples from blood donors from the north of Pakistan. Blood samples were taken with consent from 300 blood donors; DNA was extracted and tested for DO*01 and DO*02 alleles by sequence-specific primer polymerase chain reaction (PCR-SSP), followed by gel electrophoresis. Allele frequencies were calculated. The observed and expected genotype frequencies were compared using the χ² test. The allele frequencies for DO*01 and DO*02 were 0.40 and 0.60, respectively. Genotype frequencies were in Hardy-Weinberg equilibrium. This study in Pakistani blood donors provides Dombrock blood group allele frequencies by PCR-SSP. This approach is efficient and economical and can be applied in developing countries. The findings can contribute to the development of in-house red blood cell panels, identification of rare blood types, and establishment of a national rare blood donor program.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Elucidating antiviral activity of Curcuma longa against H9 N2 influenza virus using embryonated chicken egg model

Curcumin is a potent antimicrobial herb used traditionally as a spice in culinary. This study was designed to evaluate the antiviral effects of curcuma longa extract against H₉ influenza virus. A total of 60 embryonated eggs were equally divided into 5 groups with 12 eggs in each group. Group 1 (G1) served as uninfected negative control. Whereas Group 2 (G2) was kept as positive control infected with known virus @ 0.2 ml with 10^-9.3 EID₅₀. Group 3 (G3) was offered Curcuma longa @ 0.2 mg/0.2 ml and H₉N₂ virus (@ 0.2 ml with 10^-9.3 EID₅₀. Similarly, Group 4 (G4) was inoculated with extract of Curcuma longa @ 0.2 mg/0.2 ml per egg, whereas Group 5 (G5) was given Ribazole @ 0.2 ml/ egg. The crude extract and virus were administered on the 15^th day of incubation and were checked after every 24 hours up to 96th hour post inoculation by random selection of 3 eggs. Death and survival rate were noted in all groups. Gross and histopathological lesions were also observed. Results revealed that Curcuma longa extract had significantly (p<0.05) reduced the mortality rate of embryos infected with H₉N₂ virus. In G3, increased lymphocytes and mild fatty changes were seen in liver. Whereas, mature RBCs, plasma cells and some lymphoblast's were observed in Spleen. Similarly, the bursa follicles were with lymphocytic aggregation. The G4 (Curcuma longa) and G5 (Ribazole) were with maximum embryo survival after 48 and 72 h post inoculation. This study revealed potential antiviral activity of Curcuma longa against H9N2 influenza viruses and can be opted as alternative to antibiotics and antiviral drugs to minimize the antimicrobial resistance in human and animal population.

Molecular detection of Mycoplasma gallisepticum in different poultry breeds of Abbottabad and Rawalpindi, Pakistan

The poultry sector in Pakistan is contributing mainly in bridging gap between demand and supply for protein. Mycoplasma gallisepticum is an emerging bacterium causing serious problems in poultry industry of Pakistan. A cross-sectional study was conducted to evaluate the M. gallisepticum load in poultry populated regions of Pakistan. Total 600 serum and 600 swab samples were collected, 200 from each broiler, layers and breeders poultry in Rawalpindi and Abbottabad districts. Serum samples were analyzed through ELISA for seroprevalence. Swabs were cultured on Frey's medium followed by PCR and partial mgc2 gene sequencing. Results of seroprevalence of M. gallisepticum showed that layers (75%, n=150) are more positive as compared to breeders (70%, n=140) and broilers (50%, n=100). Typical colonies of the M. gallisepticum were observed in breeder (26.5%), followed by layer (21%) and broilers (9%). A total of 37.1% (n=42) samples were identified positive through PCR out of total 113 cultured based positive samples. A total of six M. gallisepticum isolates of current study showed 98-99 percent similarity with previously reported isolates on the basis of mgc2 gene partial sequencing. The M. gallisepticum was found highly prevalent in different poultry breads. Results of this study would add into basic data and provide a direction for livestock sector to strengthen a control strategy for mycoplasmosis in poultry farms.

The impact of fluence dependent 120 MeV Ag swift heavy ion irradiation on the changes in structural, electronic, and optical properties of AgInSe2 nano-crystalline thin films for optoelectronic applications

Swift heavy ion (SHI) irradiation in thin films significantly modifies the structure and related properties in a controlled manner. In the present study, the 120 MeV Ag ion irradiation on AgInSe₂ nanoparticle thin films prepared by the thermal evaporation method and the induced modifications in the structure and other properties are being discussed. The ion irradiation led to the suppression of GIXRD and Raman peaks with increasing ion fluence, which indicated amorphization of the AgInSe₂ structure along the path of 120 MeV Ag ions. The Poisson's fitting of the ion fluence dependence of the normalized area under the GIXRD peak of AgInSe₂ gave the radius of the ion track as 5.8 nm. Microstructural analysis using FESEM revealed a broad bi-modal distribution of particles with mean particle sizes of 67.5 nm and 159 nm in the pristine film. The ion irradiation led to the development of uniform particles on the film surface with a mean size of 36 nm at high ion fluences. The composition of the film was checked by the energy dispersive X-ray fluorescence (EDXRF) spectrometer. The UV-visible spectroscopy revealed the increase of the electronic bandgap of AgInSe₂ films with an increase in ion fluence due to quantum confinement. The Hall measurement and EDXRF studies showed that the unirradiated and irradiated AgInSe₂ films have n-type conductivity and vary with the ion fluence. The changes in the films were tuned with different ion fluence and are favorable for both optical and electronic applications.

Swift heavy ion (SHI) irradiation in thin films significantly modifies the structure and related properties in a controlled manner.

Probing CAS database as prospective antiviral agents against SARS-CoV-2 main protease

The pandemic of COVID-19 has an unprecedented impact on global health and economy. The novel SARS-CoV-2 is recognized as the etiological agent of current outbreak. Because of its contagious human-to-human transmission, it is an utmost global health emergency at present. To mitigate this threat many scientists and researchers are racing to develop antiviral therapy against the virus. Unfortunately, to date no vaccine or antiviral therapeutic is approved thus there is an urgent need to discover antiviral agent to help the individual who are at high risk. Virus main protease or chymotrypsin-like protease plays a pivotal role in virus replication and transcription; thus, it is considered as an attractive drug target to combat the COVID-19. In this study, multistep structure based virtual screening of CAS antiviral database is performed for the identification of potent and effective small molecule inhibitors against chymotrypsin-like protease of SARS-CoV-2. Consensus scoring strategy combine with flexible docking is used to extract potential hits. As a result of extensive virtual screening, 4 hits were shortlisted for MD simulation to study their stability and dynamic behavior. Insight binding modes demonstrated that the selected hits stabilized inside the binding pocket of the target protein and exhibit complementarity with the active site residues. Our study provides compounds for further in vitro and in vivo studies against SARS-CoV-2.

Knowledge, attitudes, and perceptions related to telemedicine among young doctors and nursing staff at the King Abdul-Aziz University Hospital Jeddah, KSA

Objective

To investigate the knowledge, perceptions, and attitude of young doctors and nurses at Kind Abdulaziz University Hospital (KAUH) Jeddah, KSA, regarding the effectiveness of telemedicine in dealing with the patients for either follow-up or continuous monitoring of chronic diseases.

Material and Methods

This prospective cross-sectional study was carried out on the young doctors and nursing staff at KAUH. An online questionnaire addressing all the required fields, i.e., background essential demography, perceptions, acceptance, and knowledge regarding telemedicine's utility, was sent to the targeted population of health care workers. Completed responses were analyzed statistically as per study objectives.

Results

The response rate in our study was 85%. A total of 335 participants responded to our questionnaire. One hundred seventy-one (51.1%) were doctors, whereas one hundred sixty-four (48.9%) were the nursing staff. Among doctors, 50 (29.4%) were recent graduates, whereas, in the nursing side, 77 (46.7%) were the senior nursing students. The knowledge and attitude of the young nursing staff were relatively better than the senior staff taking part in the study and the trends were found statistically significant.

Conclusion

Our study participants, being young, were enthusiastic, had good knowledge regarding the advantages and limitations of telemedicine in managing the selected groups of patients. Their perception and attitude were quite positive. This is an encouraging trend in the promotion of telemedicine as an established way of managing patients with special requirements in an effective way. The ongoing COVID-19 pandemic has highlighted the importance of telemedicine in emergencies to protect both patients and health care workers by reducing chronic patients' avoidable hospital visits.

Luminal-apposing stents for benign intraluminal strictures: a large United States multicenter study of clinical outcomes

Background

The use of fully covered lumen-apposing metal stents (LAMS) for benign short gastrointestinal (GI) strictures has been reported. This study aimed to evaluate the safety and efficacy of LAMS for refractory GI strictures.

Methods

A retrospective analysis was performed of patients who underwent LAMS placement for benign GI strictures in 8 United States centers. The primary outcomes were technical success and initial clinical response. Secondary outcomes were reintervention rate and adverse events.

Results

A total of 51 patients underwent 61 LAMS placement procedures; 33 (64.7%) had failed previous treatments. The most common stricture location was the pylorus (n=17 patients). Various sizes of stents were used, with 15-mm LAMS placed in 45 procedures, 20-mm LAMS in 14 procedures, and 10-mm LAMS in 2 procedures. The overall technical success, short-term clinical response and reintervention rate after stent removal were 100%, 91.8% and 31.1%, respectively. Adverse events were reported in 17 (27.9%) procedures, with stent migration being the most common (13.1%). In subgroup analysis, both 15 mm and 20 mm stents had comparable short-term clinical response and adverse event rates. However, stent migration (15.6%) was the most common adverse event with 15-mm LAMS while pain (14.3%) was the most common with 20-mm LAMS. The reintervention rate was 80% at 200-day follow up after stent removal.

Conclusions

Using LAMS for treatment of short benign GI strictures is safe and effective. Larger LAMS, such as the new 20 mm in diameter, may have a lower stent migration rate compared to smaller diameter LAMS.

Novel 4,6-Disubstituted s-Triazin-2-yl Amino Acid Derivatives as Promising Antifungal Agents

A novel series of 4,6-disubstituted s-triazin-2-yl amino acid derivatives was prepared and characterized. Most of them showed antifungal activity against Candida albicans compared to clotrimazole (standard drug). Compounds bearing aniline derivatives, piperidine and glycine on the triazine core showed the highest inhibition zones at concentrations of 50, 100, 200, and 300 μg per disc. In addition, docking studies revealed that all the compounds accommodated well in the active site residues of N-myristoltransferase (NMT) and exhibited complementarity, which explains the observed antifungal activity. Interestingly, none of these compounds showed antibacterial activity.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2  GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Identification of chymotrypsin-like protease inhibitors of SARS-CoV-2 via integrated computational approach

Recently, the world has witnessed outbreak of a novel Coronavirus (SARS-CoV-2), the virus which initially emerged in Wuhan, China has now made its way to a large part of the world, resulting in a public emergency of international concern. The functional importance of Chymotrypsin-like protease (3CL^pro) in viral replication and maturation turns it into an attractive target for the development of effective antiviral drugs against SARS and other coronaviruses. At present, there is no standard drug regime nor any vaccine available against the infection. The rapid development and identification of efficient interventions against SARS-CoV-2 remains a major challenge. Based on the available knowledge of closely related coronavirus and their safety profiles, repurposing of existing antiviral drugs and screening of available databases is considered a near term strategic and economic way to contain the SARS-CoV-2 pandemic. Herein, we applied computational drug design methods to identify Chymotrypsin-like protease inhibitors from FDA approved antiviral drugs and our in-house database of natural and drug-like compounds of synthetic origin. As a result three FDA approved drugs (Remdesivir, Saquinavir and Darunavir) and two natural compounds (. flavone and coumarine derivatives) were identified as promising hits. Further, MD simulation and binding free energy calculations were performed to evaluate the dynamic behavior, stability of protein-ligand contact, and binding affinity of the hit compounds. Our results indicate that the identified compounds can inhibit the function of Chymotrypsin-like protease (3CL^pro) of Coronavirus. Considering the severity of the spread of coronavirus, the current study is in-line with the concept of finding the new inhibitors against the vital pathway of the corona virus to expedite the process of drug discovery.Communicated by Ramaswamy H. Sarma.

Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC

The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58  MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.

Abstract ES3-2: Sooner or later: considering risk over time, and implications for management

Cancer risk management revolves around the following important areas: genetic evaluation, surveillance recommendations, risk-reducing options, and lifestyle modification. Aspects of time are important for all of these areas, with the possible exception of lifestyle modification. For genetic evaluation, age at onset of affected individuals is a key parameter. Decisions about surveillance and risk-reducing strategies are based on age, and time-dependent estimates of cancer risk, with the most commonly-used time-frames being 5 years, 10 years, and remaining lifetime (to age 85 or 90). However, little attention is generally given to the time-frame of the benefit. For example, surveillance recommendations are based on lifetime risk when in fact the benefit (as defined by cancer detection success) cannot exceed the lead-time of the test. On the other hand, risk reduction (particularly with medication) is often presented based on risk estimated over the next 5 years. As more women are designated high risk, given increased prevalence of MRI surveillance and subsequent biopsies, and increased use of genetic testing with identification of moderate penetrance genetic variants, the question of risk thresholds that should be used for recommendations related to risk management become increasingly important. Surveillance recommendations: Remaining lifetime risk (RLR) estimates for women in their 40s generally project over 40 years or more. However, validation of these very long-term projections remains questionable, and validation is most robust for the 10-year time-frame (PMID 25956172). The lead-time gained with MRI surveillance has been estimated at 1-2 years for carriers of BRCA 1/2 mutations, and 4 years for non-carriers with positive family history of breast cancer (PMID 25820931) The predicted mean preclinical detectable phase (i.e. the time during which a cancer is screen-detectable) is estimated to be 1 to 4 years for BRCA1 and 2 to 7 years for BRCA2 (PMID 22744338). Similar estimates for non-carrier women at increased familial risk are unlikely to be longer than 10 years. Therefore, given the greater reliability of 10-year risk estimates, it appears most reasonable to make recommendations for intensified screening based on 10-year risk rather than RLR. Recommendations for use of risk-reducing medications (RR-meds): In contrast to screening, have been made to non-carrier high risk women based on 5-year risk estimates of 1.7% or greater. Acceptance of medications has been low for a variety of reasons, one of which is the seemingly small risk conveyed by a 5-year risk estimates. Here, it would seem reasonable to extend the time-frame over which risk is calculated, since the protective benefit of tamoxifen is known to extend to ~15 years, and is likely to be in the same range for aromatase inhibitors. New ASCO guidelines on use of RR-meds now includes 10-year estimates of 3% with the NCI BCRAT, or 5% with the Tyrer-Cuzick. In summary, the use of 10-year risk estimates would simplify the management counseling of women at increased risk of breast cancer for both practitioner and patient, and place it on a better evidence base than the use of RLR or the 5-year interval.

Citation Format: SA Khan. Sooner or later: considering risk over time, and implications for management [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES3-2.

Role of cannabis in inflammatory bowel diseases

For many centuries, cannabis (marijuana) has been used for both recreational and medicinal purposes. Currently, there are about 192 million cannabis users worldwide, constituting approximately 3.9% of the global population. Cannabis comprises more than 70 aromatic hydrocarbon compounds known as cannabinoids. Endogenous circulating cannabinoids, or endocannabinoids, such as anandamide and 2-arachidonoyl-glycerol, their metabolizing enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) and 2 G-protein coupled cannabinoid receptors, CB1 and CB2, together represent the endocannabinoid system and are present throughout the human body. In the gastrointestinal (GI) tract, the activated endocannabinoid system reduces gut motility, intestinal secretion and epithelial permeability, and induces inflammatory leukocyte recruitment and immune modulation through the cannabinoid receptors present in the enteric nervous and immune systems. Because of the effects of cannabinoids on the GI tract, attempts have been made to investigate their medicinal properties, particularly for GI disorders such as pancreatitis, hepatitis, and inflammatory bowel diseases (IBD). The effects of cannabis on IBD have been elucidated in several small observational and placebo-controlled studies, but with varied results. The small sample size and short follow-up duration in these studies make it difficult to show the clear benefits of cannabis in IBD. However, cannabis is now being considered as a potential drug for inflammatory GI conditions, particularly IBD, because of its spreading legalization in the United States and other countries and the growing trend in its use. More high-quality controlled studies are warranted to elucidate the mechanism and benefits of cannabis use as a possible option in IBD management.

Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15  GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15  GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Evaluation of bioherbicidal potential of Carica papaya leaves

Due to increased number of herbicide resistant weeds, it is needed to explore the allelopathic potential of plants as an alternative. The research was conducted to investigate allelopathic effects of Carica papaya L. leaf powder and aqueous extract on seeds as well as pre-germinated seeds of Avena fatua L., Helianthus annuus L., Rumex dentatus L., Zea mays L. and Triticum aestivum L. on filter paper and soil in Weed Management Program Laboratory, Department of Plant and Environmental Protection at PARC Institute of Advanced Studies in Agriculture, National Agriculture Research Centre, Islamabad, Pakistan. Germination percentage (%), radicle length (cm) and plumule length (cm) were parameters observed for 'Plant leaf powder bioassay' and 'Aqueous extract method'. Most significant growth inhibition was observed in A. fatua seedlings in filter paper method. A. fatua radicle length was reduced by C. papaya aqueous extract (80%) and leaf powder (89%) bioassays. Plumule length was reduced under the influence of aqueous extract (57-73%) and powdered material (59-77%). The inhibitory effects on other test species were in sequence of H. annuus followed by Z. mays and R. dentatus. The aqueous extract showed non-significant effect on wheat seed germination, radicle and plumule growth. It is suggested that C. papaya aqueous extract can be used as source of weed management in wheat crop.

An outbreak of Japanese encephalitis in a non-endemic region of north-east India

Background There are few comprehensive reports of epidemic Japanese encephalitis in a previously unaffected region. We report our experience of a first-ever outbreak of it in Sonitpur District, Assam, India, with 45 laboratorycon confirmed cases at a single hospital. Method Between 2 July and 11 August 2008, patients meeting the WHO definition of acute encephalitis syndrome were assessed in a single hospital and had tests including blood and cerebrospinal fluid for Japanese encephalitis antibody titres. Results Ninety-six cases meeting the definition of acute encephalitis syndrome were identified with 45 cases of Japanese encephalitis confirmed by cerebrospinal fluid or blood results. For Japanese encephalitis positive patients, mean age was 36 (range 4-80). Of the 45, 11 (24%) died and a further 21 (47%) had significant residual deficits. Focal neurological signs (40%) and seizures (25%) were common. Conclusion An effective Japanese encephalitis vaccine is the key intervention for limiting the population impact of this disease. Identification of these cases led to a district-wide mass vaccination campaign.

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, Xe-Xe at sqrt[s_{NN}]=5.44  TeV, and Pb-Pb at sqrt[s_{NN}]=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0  GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.

First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

Assessing a thermal spike model of swift heavy ion-matter interactions via Pd1-xNix/Si interface mixing

The thermal spike model (TSM), a widely accepted mechanism of swift heavy ion (SHI)-matter interactions, provides explanation for various SHI induced effects, including mixing across interfaces. We assess the validity of the model via tuning the electron-phonon coupling strength (G) by taking a series Pd_1-xNi_x of a completely solid soluble binary, and then observing Pd_1-xNi_x/Si interface mixing induced by a combination of 100 MeV Au ion irradiation and 4 keV Ar ion sputtering. If the TSM truly describes the SHI-matter interaction mechanism, any non-linearity in x-variation of G must also result in a similar non-linearity in the x-dependence of mixing. Experimentally, the extent of mixing has been parametrized by the irradiation induced change Δσ² in variances of Pd and Ni depth profiles derived from XPS. Computationally, G determined using density functional theory has been used to solve the equations appropriate to the TSM, and then an equivalent quantity L², proportional to Δσ², has been calculated. Both Δσ²(x) and L²(x) show non-linearities, albeit in slightly dissimilar ways, leading to a conjecture that the present work at least does not invalidate the TSM.

Structure Analysis and Ferroelectric Response of Bi0.5Na0.5TiO₃ Nanopowder Synthesized by Sol-Gel Method

In this work, bismuth sodium titanate, Bi_0.5±xNa_0.5±yTiO₃ (BNT, x, y = -0.05-0.08) nanopowders were produced using the low-temperature sol-gel technique. The effects of deficient and excess amounts of Bi and Na on BNT structure were systemically examined through X-ray powder diffraction (XRD), energy dispersive analysis (EDS) and scanning electron microscope (SEM). The optimized composition of the BNT nanopowder was pelletized and sintered at different temperatures (950°C-1150 °C). Highly dense ceramics possessing pure perovskite phase was observed for the sample sintered at an optimum sintering temperature (1100 °C). The ferroelectric properties were found to increase with an increase in sintering temperature up to 1100 °C and then decrease. This study justifies that Bi and Na non-stoichiometry (proper excess), processing and sintering temperatures play important role in the successful synthesis of BNT ceramics.

Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v_{2}) for heavy-flavor decay electrons in the transverse momentum interval 1.5<p_{T}<4  GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v_{2} measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.

Abstract P6-21-12: Local transdermal therapy (LTT): Drug permeation and distribution of telapristone acetate (TPA) in a pre-surgical window study of women undergoing mastectomy

Background: Low uptake and poor adherence to oral drugs for breast cancer prevention and ductal carcinoma in situ has led to an interest in local routes of delivery with the intent of decreasing systemic exposure and reducing toxicity. LTT has emerged as a possible alternative; previous studies have shown selectively higher concentrations in the breast than in the serum with this delivery route. A question related to LTT is whether or not the drug will permeate and distribute throughout the breast, as is expected with oral delivery.

Methods: We conducted a double-blind study of oral versus LTT delivery of the selective progesterone receptor modulator, telapristone acetate (TPA), in a presurgical window setting, enrolling 82 women planning therapeutic or prophylactic mastectomy. We randomized 67 women 1:1, to oral TPA 12 mg daily, or gel TPA applied to both breasts daily (12 mg/breast), for 4 weeks ±1 week. Mastectomy specimens were sampled at 5 non-tumor locations as well as the tumor and lymph node when available. Samples were split in two: drug concentration (conc.) assay using LC-MS/MS and histological evaluation of tissue composition (fat, fibrous stroma, epithelium). The primary endpoint was mean drug conc. across all breast locations (anticipating that the gel would deliver a mean concentration that was &gt;50% of the mean in the oral group). A secondary endpoint was the drug distribution pattern across the breast, expecting that the distribution would be similar. The tumor sample was saved for biomarker assays related to TPA action; these are ongoing, for a pre-planned pooled analysis of data with NCT01800422 (reported in SABCS abstract 851863).

Results: Of 63 evaluable women (33 oral and 30 gel group), 27 had unilateral and 36 had bilateral mastectomy. The mean drug conc. in the oral group was 166.3 ng/G (SE 11.7), and in the gel group was 10.6 ng/G (SE 10.8), (p&lt;.0001). The conc. was variable across the 7 locations tested in both groups. High concentrations were found in the superficial and deep central locations, retroareolar and lateral locations ranked in the middle, and the medial location was discrepant, being high in the oral and low in the gel group. The variation in drug concentration across all locations was not significantly different between groups (Kolmogorov-Smirnov p=0.99). Among women with bilateral mastectomy, drug concentrations were similar between breasts in both oral and gel groups. In the gel group, despite low TPA concentrations, there was evidence of drug metabolism. The major metabolite, CDB 4453 was detectable in 192/193 samples with detectable parent drug. Analysis of drug concentration adjusted for tissue composition is ongoing.

Conclusions: The gel formulation of TPA did not permeate the skin well. However, the drug delivered to the breast was distributed throughout the breast, similar to the oral delivery route, with the highest concentration in the deep central location. These drug distribution data are novel; drug distribution at multiple locations throughout the breast has not previously been shown. Further work is needed to understand breast distribution with formulations known to have good dermal permeation.

Citation Format: Lee O, Pilewskie M, Xu Y, Benante K, Blanco L, Helenowski I, Tull MB, Muzzio M, Jovanovic B, Karlan S, Hansen N, Bethke K, Kulkarni S, Perloff M, Dimond EP, Heckman-Stoddard BM, Khan SA. Local transdermal therapy (LTT): Drug permeation and distribution of telapristone acetate (TPA) in a pre-surgical window study of women undergoing mastectomy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-21-12.

Abstract OT1-04-01: A phase IIB pre-surgical trial of oral tamoxifen (TAM) versus transdermal 4-hydroxytamoxifen (4-OHT) in women with DCIS of the breast

Background

Ductal carcinoma in situ (DCIS) is diagnosed in 60,000 women annually in the US. TAM is proven to reduce risk of local recurrence and new primary breast cancer in women with estrogen receptor (ER) positive DCIS. However, acceptance of TAM has been low, primarily because of toxicity related to systemic exposure. Local delivery to the breast is an attractive alternative since low systemic levels could minimize toxicity. 4-OHT is an active metabolite of TAM. When formulated as a gel and applied to the breast skin, it is well tolerated, and results in 4-OHT breast tissue drug levels comparable oral TAM. In small pilot studies, its anti-proliferative effects on invasive breast tumors and DCIS are also similar to oral TAM [Lee O, et al. PMID 25028506]. The goal of our study is to validate these results in preparation for a Phase III trial of 4-OHT gel in comparison to oral TAM.

Methods

We are conducting a randomized, double-blinded, placebo-controlled, Phase IIB pre-surgical trial to demonstrate that daily application of 4-OHT gel will result in a reduction in the Ki-67 labeling index of DCIS lesions that is not inferior to that seen in women receiving daily oral TAM 20 mg daily. Ki-67 of the base-line diagnostic core needle biopsy will be compared to that of the therapeutic surgical excision sample after oral TAM or 4-OHT gel for 8 ± 2 weeks. Secondary endpoints include changes in Oncotype DCIS-Score, IHC markers (CD68, COX2, p16), hormone levels, coagulation markers, drug concentration in the plasma and breast tissue, the fraction of women with no residual DCIS in the surgical sample, and experienced symptoms. 100 women (assuming 20% non-evaluable samples or compliance issues) with DCIS (10% ER-positive) will be enrolled across six institutions into two intervention arms: oral TAM 20 mg daily, placebo gel and 4-OHT gel 4mg daily (2mg/breast), placebo capsule. All participants will be evaluable for toxicity from their first dose. All samples from all participants who receive drug will be evaluated and included in the primary analysis, which will be based on intent to treat principle. To date 15 of 100 participants have been enrolled across six institutions including: Northwestern University in Chicago, IL, St. Elizabeth Healthcare in Edgewood, KY, Duke University Medical Center in Durham, NC, Cleveland Clinic in Cleveland, OH, Memorial Sloan Kettering Cancer Center in New York, NY, and Mayo Clinic in Rochester, MN. Since study open, 69 potential participants have been contacted, 52 did not consent for screening, 17consented for screening, 2 are pending consent, and 15 have started study intervention. The most common reasons potential participants chose not to consent are wanting to schedule surgery as soon as possible, attitudes toward medical research, and current use of a prohibited concomitant medication such as a potent inhibitor of tamoxifen metabolism or exogenous sex steroid.

Funding Source: NCI Contract # HHSN2612201200035I.

Citation Format: Benante KA, Xu Y, Tull MB, Segura AJ, Alber KM, Kalinichenko K, Hou L, Jovanovic B, Perloff M, Heckman-Stoddard B, Dimond E, Khan SA. A phase IIB pre-surgical trial of oral tamoxifen (TAM) versus transdermal 4-hydroxytamoxifen (4-OHT) in women with DCIS of the breast [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-04-01.

Abstract P3-09-02: CRISPR-Cas9 mediated BRCA1 mutation in primary cells: Mutation efficiency and effects

Background: Germline mutations in Breast Cancer Associated (BRCA) 1 or 2 genes confer an increased risk of the development of breast and ovarian cancer. Germline mutation is followed by somatic loss of heterozygosity (LOH) resulting in biallelic inactivation. BRCA1 is involved in multiple homeostatic functions including control of chromatin organization, gene transcription, protein stability and cell division. Recent studies have demonstrated heterogeneity in LOH within and between premalignant and malignant breast tissues of BRCA1 mutation carriers. We hypothesize that LOH does not have a unitary effect on phenotype but differs by the function that is abrogated.

Methods: To test our hypothesis, we adopted CRISPR-Cas9 gene editing technology. The guide RNAs for targeting the exon sequence in the RING finger, nuclear export signal (NES), nuclear localization signal (NLS) and BRCA1 C Terminus (BRCT) domain/motif of BRCA1 were designed and synthesized. MCF10A cells were transfected with a complex of guide RNA and Cas9 protein (RNP) to cause in/del mutation. The mutation was analyzed by both T7E1 assay, and an innovative and more precise method developed in our lab that utilizes linked nucleic acids (LNA) and qPCR. Proliferation and apoptosis assays were performed using the transfected cells. Organoids prepared from BRCA1 mutation carriers also were transfected with RNPs and the mutation burden determined.

Results: Since single cell clones of the transfected MCF10A cells could not be selected and expanded, a pool of transfected cells was used for the analyses. T7E1 assay and qPCR analysis using LNAs demonstrated the presence of the mutations. A standard curve was created to enable the calculation of the mutation burden. IncuCyte analysis revealed increased proliferation and apoptosis, induced by irradiation, in cells with the mutation in Exon 10, where the extent of increase varied from 11% to 48% depending on the degree of mutation. In contrast, cells with the mutation in Exon 5 displayed diminished proliferation with no change in apoptosis. That mutations in exon10 and 5 have distinct biological effects when compared to the mutations in other exons is intriguing, and modification of binding proteins will be investigated. Organoids generated from BRCA1 mutation carriers (primary and nonmalignant cells) were able to be successfully transfected using the NEON electroporation system. Mutations were introduced by the CRISPR-Cas9 system and their extent quantified by our LNA-mediated qPCR method.

Conclusions: CRISPR-Cas9-mediated gene editing of BRCA1 in MCF10A resulted in a change in the proliferation rate and the extent of apoptosis that is dependent on the location of the de novo mutation within the gene. The development of a novel method, LNA-mediated qPCR, provides quantitative information regarding the mutations that may be used to correlate mutation burden with biological functional change. Successful establishment of this BRCA1 tumorigenesis model has provided us with a method to test other putative tumor suppressors.

Citation Format: Choi MR, Yadav S, Shidfar A, Khan SA, Clare SE. CRISPR-Cas9 mediated BRCA1 mutation in primary cells: Mutation efficiency and effects [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-09-02.

Abstract P3-06-06: Novel breast cancer mutational signatures

Background: Our understanding of the biological processes that generate somatic mutations in breast cancer has increased markedly over the past five years. Using the catalog of somatic mutations present in cancer genomes, over 30 “mutational signatures” have been produced. While these provide important insights into the processes responsible for somatic mutation, gaps remain, and the etiology of several signatures remains unknown.

Methods: We have developed a new method in which the specific nucleotide change (e.g., C&gt;T), the codon that each mutation falls in (e.g., GCT), the position in the codon (e.g., 2), and the nucleotides immediately 5' and 3' of the mutation (e.g., 5': C; 3': G) are all considered. The summary of these mutation characteristics forms a mutational profile for each tissue sample. Putting multiple samples' profiles together forms a sparse matrix with the number of samples as rows and the mutation characteristics as columns. Nonsmooth nonnegative matrix factorization was then applied to enable the discovery of intrinsic patterns in this sparse matrix.

Results: Using somatic mutations identified in 1017 breast cancer tissues from The Cancer Genome Atlas (TCGA), we have identified four mutational signatures. Signature A correlates with the well-defined APOBEC signatures and signature B with the “aging” signature, which is the result 5-methylcytosine hydrolysis. Signature C and signature D are potentially new signatures. Signature D is enriched with C:G&gt;A:T mutations; these mostly occur in the middle position of codons, and are enriched with GG(CC) either 5' or 3' of the mutation's sequence context. G&gt;T mutations are known to occur as a consequence of oxidative damage that is not repaired. Guanines are vulnerable as they have the highest vertical oxidation potential of the nucleobases. The 5' guanines in GG sites are especially reactive. We hypothesize that Signature D results from oxidative mutagenesis.

When correlated with clinical phenotypes, the basal subtype is clearly enriched for tumors with the Signature D mutation pattern (exposure level is in 169 basal tumors and in 797 non-basal tumors, p=&lt;0.01), suggesting an etiologic link with basal-like breast cancer. G&gt;T somatic mutations in breast cancer mainly take place during cell replication rather than during transcription. In the normal breast, epithelial cell replication occurs during the luteal phase of the menstrual cycle and during pregnancy, primarily under the direction of progesterone (P). P binds to its receptor (PR) in a subpopulation of PR positive cells where it initiates the transcription of genes including RANKL, with resultant paracrine stimulation (through RANK), of the NF-κB signaling pathway in neighboring cells. The four RANKL genes (TOP2A, MKI67, PBK, CDK1), defined by Nolan et al., are all positively associated with the signature D (P-values &lt; 0.05), suggesting that this type of mutagenesis is associated with RANKL pathway upregulation.

Conclusions: We have identified a potentially new somatic mutational signature, which we have designated as Signature D, which appears to result from exposure of DNA to oxidative stress during replication. It is associated with the basal subtype of breast cancer as well as RANKL- NF-κB pathway upregulation.

Citation Format: Zeng Z, Vo AH, Luo Y, Khan SA, Clare SE. Novel breast cancer mutational signatures [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-06-06.