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Lopinavir is a potent protease inhibitor that is used as a first-line pharmaceutical drug for the treatment of HIV. The multi-component solvated Lopinavir crystal, systematic name (2S)-N-[(2S,4S,5S)-5-[2-(2,6-dimethylphenoxy)acetamido]-4-hydroxy-1,6-diphenylhexan-2-yl]-3-methyl-2-(2-oxo-1,3-diazinan-1-yl)butanamide–ethane-1,2-diol–water (8/3/7) 8C37H48N4O5·3C2H6O2·7H2O, was prepared using evaporative methods. The crystalline material obtained from this experimental synthesis was characterized and elucidated by single-crystal X-ray diffraction (SC-XRD). The crystal structure is unusual in that the unit cell contains 18 molecules. The stoichiometric ratio of this crystal is eight Lopinavir molecules [8(C37H48N4O5)], three ethane-1,2-diol molecules [3(C2H6O2)] and seven water molecules [7(H2O)]. The crystal packing features both bi- and trifurcated hydrogen bonds between atoms.

AIDS is one of the deadliest diseases in the history of humankind caused by HIV. Despite the technological development, curtailing the viral infection inside human host still remains a challenge. Therapies such as HAART uses a combination of drugs to inhibit the viral activity. One of the important targets includes HIV protease and inhibiting its activity will minimize the production of mature structural proteins. However, the genetic diversity and the occurrence of drug resistant mutations adds complexity to effective drug design. In this study, we aimed at understanding the drug binding mechanism of one such subtype, namely subtype C and its insertion variant L38HL. We performed multiple molecular dynamics simulations along with binding free energy analysis of wild-type and L38HL bound to Atazanavir (ATV). From the analysis, we revealed that the insertion alters the hydrogen bond and hydrophobic interaction networks. The alterations in the interaction networks increase flexibility at the hinge-fulcrum interface. Further, the effects of these changes affect flap tip curling. Moreover, the changes in the hinge-fulcrum-cantilever interface alters the concerted motion of the functional regions leading to change in the direction of flap movement thus causing a subtle change in the active site volume. Additionally, formation of intramolecular hydrogen bonds in the ATV docked to L38HL restricted the movement of R1 and R2 groups thereby altering the interactions. Overall, the changes in the flexibility of flap together with the changes in the active site volume and compactness of the ligand provide insights for increased binding affinity of ATV with L38HL.

The unusual and interesting architecture of the catalytic chamber of the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) was recently explored using Cryogenic Electron Microscopy (Cryo-EM), which revealed the presence of two distinctive binding cavities within the catalytic chamber. In this report, first, we mapped out and fully characterized the variations between the two binding sites, BS1 and BS2, for significant differences in their amino acid architecture, size, volume, and hydrophobicity. This was followed by investigating the preferential binding of eight antiviral agents to each of the two binding sites, BS1 and BS2, to understand the fundamental factors that govern the preferential binding of each drug to each binding site. Results showed that, in general, hydrophobic drugs, such as remdesivir and sofosbuvir, bind better to both binding sites than relatively less hydrophobic drugs, such as alovudine, molnupiravir, zidovudine, favilavir, and ribavirin. However, suramin, which is a highly hydrophobic drug, unexpectedly showed overall weaker binding affinities in both binding sites when compared to other drugs. This unexpected observation may be attributed to its high binding solvation energy, which disfavors overall binding of suramin in both binding sites. On the other hand, hydrophobic drugs displayed higher binding affinities towards BS1 due to its higher hydrophobic architecture when compared to BS2, while less hydrophobic drugs did not show a significant difference in binding affinities in both binding sites. Analysis of binding energy contributions revealed that the most favorable components are the ΔEele, ΔEvdw, and ΔGgas, whereas ΔGsol was unfavorable. The ΔEele and ΔGgas for hydrophobic drugs were enough to balance the unfavorable ΔGsol, leaving the ΔEvdw to be the most determining factor of the total binding energy. The information presented in this report will provide guidelines for tailoring SARS-CoV-2 inhibitors with enhanced binding profiles.

Novel dithiourea derivatives have been designed as HIV-1 protease inhibitors using Autodock 4.2, synthesized and characterized by spectroscopic methods and microanalysis. 1-(3-Bromobenzoyl)-3-[2-({[(3-bromophenyl)formamido]methanethioyl}amino)phenyl]thiourea (10) and 3-benzoyl-1{[(phenylformamido)methanethioyl]amino}thiourea (12) gave a percentage viability of 17.9±5.6% and 11.2±0.9% against Trypanosoma brucei. Single crystal X-ray diffraction analysis of 1-benzoyl-3-(5-methyl-2-{[(phenylformamido)methanethioyl]amino}phenyl)thiourea (1), 3-benzoyl-1-(2-{[(phenylformamido)methanethioyl]amino}ethyl)thiourea (11), 3-benzoyl-1-{[(phenylformamido)methanethioyl]amino}thiourea (12) and 3-benzoyl-1-(4-{[(phenylformamido)methanethioyl]amino}butyl)thiourea (14) have been presented. 1-(3-Bromobenzoyl)-3-[2-({[(3-bromophenyl)formamido]methanethioyl}amino)phenyl]thiourea (10) gave a percentage inhibition of 97.03±0.37% against HIV-1 protease enzyme at a concentration of 100 µM.

The Receptor Binding Domain (RBD) of SARS-CoV-2 virus harbors a sequence of Arg-Gly-Asp tripeptide named RGD motif, which has also been identified in extracellular matrix proteins that bind integrins as well as other disintegrins and viruses. Accordingly, integrins have been proposed as host receptors for SARS-CoV-2. However, given that the microenvironment of the RGD motif imposes a structural hindrance to the protein-protein association, the validity of this hypothesis is still uncertain. Here, we used normal mode analysis, accelerated molecular dynamics microscale simulation, and protein-protein docking to investigate the putative role of RGD motif of SARS-CoV-2 RBD for interacting with integrins. We found, that neither RGD motif nor its microenvironment showed any significant conformational shift in the RBD structure. Highly populated clusters of RBD showed no capability to interact with the RGD binding site in integrins. The free energy landscape revealed that the RGD conformation within RBD could not acquire an optimal geometry to allow the interaction with integrins. In light of these results, and in the event where integrins are confirmed to be host receptors for SARS-CoV-2, we suggest a possible involvement of other residues to stabilize the interaction.

Herein, we report the effect of nine FDA approved protease inhibitor drugs against a new HIV-1 subtype C mutant protease, E35D↑G↑S. The mutant has five mutations, E35D, two insertions, position 36 (G and S), and D60E. Kinetics, inhibition constants, vitality, Gibbs free binding energies are reported. The variant showed a decreased affinity for substrate and low catalytic efficiency compared to the wild type. There was a significant decrease in the binding of seven FDA approved protease inhibitors against the mutant (p

Summary: Antibodies that bind residue K169 in the V2 region of the HIV-1 envelope correlated with reduced risk of infection in the RV144 vaccine trial but were restricted to two ED-motif-encoding light chain genes. Here, we identify an HIV-infected donor with high-titer V2 peptide-binding antibodies and isolate two antibody lineages (CAP228-16H/19F and CAP228-3D) that mediate potent antibody-dependent cell-mediated cytotoxicity (ADCC). Both lineages use the IGHV5-51 heavy chain germline gene, similar to the RV144 antibody CH58, but one lineage (CAP228-16H/19F) uses a light chain without the ED motif. A cocrystal structure of CAP228-16H bound to a V2 peptide identified a IGLV3-21 gene-encoded DDxD motif that is used to bind K169, with a mechanism that allows CAP228-16H to recognize more globally relevant V2 immunotypes. Overall, these data further our understanding of the development of cross-reactive, V2-binding, antiviral antibodies and effectively expand the human light chain repertoire able to respond to RV144-like immunogens. : V2-directed antibodies from the RV144 vaccine trial correlated with reduced HIV-1 infection risk but exhibited restricted light chain gene usage. Here, van Eeden et al. isolate similar antibodies from an HIV-1-infected individual and identify a third V2-reactive light chain gene, increasing the antibody repertoire potentially elicited by vaccination. Keywords: HIV, V2 antibodies, K169, V2 structure, ED motif, CAP228, CH58, antibody evolution, ADCC, RV144 vaccine response

Common methodologies such as liquid-liquid extraction and solid-phase extraction are applied for the extraction of opioids from biological specimens i.e., blood and urine. Techniques including LC-MS/LC-MSMS, GC-MS, etc. are used for qualitative or quantitative determination of opioids. The goal of the present work is to design a green, economic, rugged, and simple extraction technique for famous opioids in human blood and urine and their simultaneous quantification by GC-MS equipped with an inert plus electron impact (EI) ionization source at SIM mode to produce reproducible and efficient results. Morphine, codeine, 6-acetylmorphine, nalbuphine, tramadol and dextromethorphan were selected as target opioids. Anhydrous Epsom salt was applied for dSPE of opioids from blood and urine into acetonitrile extraction solvent with the addition of sodium phosphate buffer (pH 6) and n-hexane was added to remove non-polar interfering species from samples. BSTFA was used as a derivatizing agent for GC-MS. Following method validation, the LOD/LLOQ and ULOQ were determined for morphine, codeine, nal-buphine, tramadol, and dextromethorphan at 10 ng/mL and 1500 ng/mL, respectively, while the LOD/LLOQ and ULOQ were determined for 6-acetylmorphine at 5 ng/mL and 150 ng/mL, respectively. This method was applied to real blood and urine samples of opioid abusers and the results were found to be reproducible with true quantification.

Bombax ceiba L. (Family: Malvaceae) was rightly called the “silent doctor” in the past as every part of it had medicinal value. For centuries, humans have used this plant according to the traditional medicinal systems of China, Ayurveda, and tribal communities. Recently, with an emerging interest in herbals, attention has been paid to scientifically validating medicinal claims for the treatment of diabetes using secondary metabolites of B. ceiba L. flowers. In the present study, specific secondary metabolites from the flowers of B. ceiba L. were isolated in good yield using the solvent extraction methodology, and their in vitro anti-diabetic efficacy was examined. Extraction efficiency of each solvent for secondary metabolites was found in following order: water > ethanol> methanol > chloroform > petroleum ether. Quantitative analysis of secondary metabolites showed 120.33 ± 2.33 mg/gm polyphenols, 60.77 ± 1.02 mg/g flavonoids, 60.26 ± 1.20 mg/g glycosaponins, 0.167 ± 0.02 mg/g polysaccharides for water extract; 91.00 ± 1.00 mg/g polyphenols, 9.22 ± 1.02 mg/g flavonoids, 43.90 ± 0.30 mg/g glycosaponins, 0.090 ± 0.03 mg/g poly saccharides for ethanol extract; 52.00 ± 2.64 mg/g polyphenols, 35.22 ± 0.38 mg/g flavonoids, 72.26 ± 1.05 mg/g glycosaponins, 0.147 ± 0.01 mg/g polysaccharides for methanol extract; 11.33 ± 0.58 mg/g polyphenols, 23.66 ± 1.76 mg/g flavonoids, 32.8 ± 0.75 mg/g glycosaponins, 0.013 ± 0.02 mg/g polysaccharides for chloroform extract; and 3.33 ± 1.53 mg/g polyphenols, 1.89 ± 1.39 mg/g flavonoids, 21.67 ± 1.24 mg/g glycosaponins, 0.005 ± 0.01 mg/g polysaccharides for petroleum ether extract. Glucose uptake by yeast cells increased 70.38 ± 2.17% by water extract., Competing Interests: The authors declare no conflict of interest.

Background: Empathy is regarded as a fundamental personal attribute for in-training and in-practice doctors. Several factors may play a significant role to facilitate or prevent the ability of doctors' empathy toward their patients. The objective of the present study is to investigate the relationship of empathy with personality traits (extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience) among undergraduate medical students., Materials and Methods: This study was based on a correlational, cross-sectional design and was conducted from January 2020 to April 2020. The sample consisted of 301 undergraduate medical students studying in different medical colleges situated in Riyadh, Saudi Arabia. Personal information form, the big-five personality inventory, and the interpersonal reactivity index scales were administered. Obtained data were analyzed by applying several methods such as mean, standard deviation, Mann-Whitney U test, Pearson's correlation coefficient, and multivariable linear regression., Results: Regression analysis revealed that personality dimensions accounted for 10-19% of the variance in scores of empathy sub-dimensions of perspective-taking, empathetic concern, fantasy, and personal distress. Agreeableness was found to be associated with empathetic concern and perspective-taking. Openness to experience was found to be significantly related to perspective-taking and fantasy, whereas extraversion was negatively associated with perspective-taking. Neuroticism had an association with personal distress, empathetic concern, and fantasy. Additionally, no gender difference was observed and students with people-oriented specialty preferences showed significantly higher scores on empathy sub-domains than technology-oriented students., Conclusion: This study confirmed that personality dimensions play a notable role to predict empathetic behaviors among Saudi undergraduate medical students. This study would help to design individualized strategies by incorporating personality dimensions in the training program to enhance empathetic behavior among medical students., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Journal of Education and Health Promotion.)

Crystal structures of hemoglobin (Hb) from two flightless birds, ostrich (Struthio camelus) and turkey (Meleagris gallopova), were determined. The ostrich Hb structure was solved to a resolution of 2.22 Å, whereas two forms of turkey Hb were solved to resolutions of 1.66 Å (turkey monoclinic structure; TMS) and 1.39 Å (turkey orthorhombic structure; TOS). Comparison of the amino-acid sequences of ostrich and turkey Hb with those from other avian species revealed no difference in the number of charged residues, but variations were observed in the numbers of hydrophobic and polar residues. Amino-acid-composition-based computation of various physical parameters, in particular their lower inverse transition temperatures and higher average hydrophobicities, indicated that the structures of ostrich and turkey Hb are likely to be highly ordered when compared with other avian Hbs. From the crystal structure analysis, the liganded state of ostrich Hb was confirmed by the presence of an oxygen molecule between the Fe atom and the proximal histidine residue in all four heme regions. In turkey Hb (both TMS and TOS), a water molecule was bound instead of an oxygen molecule in all four heme regions, thus confirming that they assumed the aqua-met form. Analysis of tertiary- and quaternary-structural features led to the conclusion that ostrich oxy Hb and turkey aqua-met Hb adopt the R-/R H -state conformation.

Mice (Mus musculus) are nocturnal small animals belonging to the rodent family that live in burrows, an environment in which significantly high CO 2 levels prevail. It is expected that mouse hemoglobin (Hb) plays an important role in their adaptation to living in such a high-CO 2 environment, while many other species cannot. In the present study, mouse Hb was purified and crystallized at a physiological pH of 7 in the orthorhombic space group P2 1 2 1 2 1 ; the crystals diffracted to 2.8 Å resolution. The primary amino-acid sequence and crystal structure of mouse Hb were compared with those of mammalian Hbs in order to investigate the structure-function relationship of mouse Hb. Differences were observed from guinea pig Hb in terms of amino-acid sequence and from cat Hb in overall structure (in terms of r.m.s.d.). The difference in r.m.s.d. from cat Hb may be due to the existence of the molecule in a conformation other than the R-state. Analysis of tertiary- and quaternary-structural features, the α1β2 interface region and the heme environment without any ligands in all four heme groups showed that mouse methemoglobin is in an intermediate state between the R-state and the T-state that is much closer to the R-state conformation.

Organophosphate, carbamate and pyrethroid pesticides are the most common insecticides used worldwide. They may cause chronic poisoning in farmers and acute poisoning in homicidal or suicidal cases. The determination of trace levels of these pesticides in human blood and urine is very challenging. This study focuses on a simultaneous quantitation method that was developed and validated for multi-class nine pesticides belonging to organophosphate, carbamate and pyrethroid classes in human blood and urine. Target pesticides were extracted from blood and urine using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method. Capillary column DB-35 ms (15 m × 0.25 mm, 0.25 µm) was used for chromatography with a 0.079 ml/min flow rate of carrier gas at constant pressure mode. Quantitation of sulfotep, phorate, carbofuran, chlorpyriphos, profenophos, triazophos, pyriproxyfen, lambda-cyhalothrin and permethrin was performed by mass spectrometer equipped with electron impact ionization source using selected ion monitoring (SIM) mode. The lower and upper limits of quantitation for all nine pesticides were 0.01 mg/L and 2.0 mg/dL respectively. The proposed method was proved to be simple, fast, sensitive, and robust. It has been applied to the analysis of 9 pesticides samples., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: To assess the relationship between psychological distress and resilience in rescue workers. Following hypothesis was formulated; there would be negative correlation between psychological distress and resilience in rescue workers. , Method: A correlational study was conducted from June-August 2015 in Rahim Yar Khan, Punjab, Pakistan. The sample of the present study consisted of 100 rescue workers. The age of the participants ranged from 23 to 40 year old with the mean age of 27.4±3.9 years. Demographic information form, Kessler psychological distress scale and adult resilience measure were administered on the participants to assess the level of psychological distress and resilience.  , Results: Pearson product moment coefficient of correlation was applied to analyze the relationship of psychological distress and resilience. Analysis of the result indicated that there is negative relationship between psychological distress and resilience (r= -0.203, p less than 0.01) in rescue workers. Further, contextual factors (r= -0.292, p less than 0.05) and its subcomponents including spiritual beliefs (r= -0.239, p less than 0.05) and cultural resources (r= -0.287, p less than 0.01) were also found to be inversely correlated with psychological distress. , Conclusion: The research evidenced that rescue workers were experiencing psychological distress Resilience factors should be considered while designing trainings to preserve mental health and to enhance the psychological well-being of rescue workers.

The objectives of the present study were to identify a possible tick vector and to determine the prevalence of camel theileriosis in Egypt using blood smears stained with Giemsa's stain and PCR assay. Hemogram and serum biochemical constituents were also investigated. A total of 243 camels, aged 3-5 years, were examined. The results revealed that 75 (30.86 %) camels were infected with Theileria spp. of Giemsa-stained blood smears. Hyalomma dromedarii was identified as the carrier tick of Theileria spp. Multinucleated sporoblast and free sporozoite were observed in the salivary gland smears from collecting ticks. PCR result revealed that Theileria annulata was the most abundant in camels (60 %) followed by Theileria spp. (10 %). Macrocytic hypochromic anemia was recorded in the infected camels with T. annulata. Leukocytosis, neutrophilia, eosinophilia, and lymphopenia were also observed in the infected group. In the serum of infected camels, total proteins, albumin, β-globulin, and A/G ratio were significantly decreased (P < 0.05); however, total globulins and α- and γ-globulins were markedly increased (P < 0.05). The activity of aspartate aminotransferase and the levels of glucose, creatinine, and high-density lipoprotein cholesterol were markedly increased (P < 0.05) in the infected group. In contrast, triglycerides and total cholesterol concentrations were significant decreased (P < 0.001) in the infected group. In conclusion, a high prevalence of camel theileriosis was recorded in apparently healthy camels. H. dromedarii commonly infested these camels and were found infected with the transmissible forms of Theileria, indicating a role in transmission. Camels infected with T. annulata induced alterations in the cellular and biochemical constituents.

Objective: The objective of the present study is to investigate the relationship of perceived social self-efficacy (PSSE) with depression in students., Methods: The sample of the present study consisted of 216 adolescent students including 120 males and 96 females randomly selected from different educational institutes of Karachi, Pakistan. The age of the participants ranged from 16 to 19 years old, with the mean age of 17.09 ± 1.13 years. Personal information form, PSSE scale, and Siddiqui-Shah depression scale were administered on the adolescent students to check the following hypothesis; there would be a negative correlation between PSSE and depression in adolescents., Results: Pearson product moment coefficient of correlation was applied to analyze the relationship between PSSE and level of depression in adolescent students. Findings of the study showed a significant negative correlation (r = -0.149, p < 0.05) between the variables of PSSE and depression., Conclusion: There is a relationship between PSSE and depression in adolescents.