Isolated Bilateral Upper Limb Amelia - A Rare Case Report.

Introduction: Congenital upper limb amelia is one of the extremely rare conditions. It is defined as a complete absence of upper limbs. It may present as isolated or with other associated anomalies. Case Report: We present a case of a 2-year-old male child with congenital complete absence of bilateral upper limb. This male child was born after four female children. With the advancement in modern-era prenatal diagnostic facilities and a better understanding of fetal-maternal drug pharmacology, such cases are rare entity. Conclusion: Amelia is a very rare and challenging situation for clinicians. Regular prenatal checkup and knowledge of maternal and fetal drug interactions during pregnancy are key factors for prevention.

Identification and mechanistic exploration of structural and conformational dynamics of NF-kB inhibitors: rationale insights from in silico and in vitro studies.

Increased expression of target genes that code for proinflammatory chemical mediators results from a series of intracellular cascades triggered by activation of dysregulated NF-κB signaling pathway. Dysfunctional NF-kB signaling amplifies and perpetuates autoimmune responses in inflammatory diseases, including psoriasis. This study aimed to identify therapeutically relevant NF-kB inhibitors and elucidate the mechanistic aspects behind NF-kB inhibition. After virtual screening and molecular docking, five hit NF-kB inhibitors opted, and their therapeutic efficacy was examined using cell-based assays in TNF-α stimulated human keratinocyte cells. To investigate the conformational changes of target protein and inhibitor-protein interaction mechanisms, molecular dynamics (MD) simulations, binding free energy calculations together with principal component (PC) analysis, dynamics cross-correlation matrix analysis (DCCM), free energy landscape (FEL) analysis and quantum mechanical calculations were carried out. Among identified NF-kB inhibitors, myricetin and hesperidin significantly scavenged intracellular ROS and inhibited NF-kB activation. Analysis of the MD simulation trajectories of ligand-protein complexes revealed that myricetin and hesperidin formed energetically stabilized complexes with the target protein and were able to lock NF-kB in a closed conformation. Myricetin and hesperidin binding to the target protein significantly impacted conformational changes and internal dynamics of amino acid residues in protein domains. Tyr57, Glu60, Lys144 and Asp239 residues majorly contributed to locking the NF-kB in a closed conformation. The combinatorial approach employing in silico tools integrated with cell-based approaches substantiated the binding mechanism and NF-kB active site inhibition by the lead molecule myricetin, which can be explored as a viable antipsoriatic drug candidate associated with dysregulated NF-kB.Communicated by Ramaswamy H. Sarma.

Late-Presenting Septic Arthritis of the Hip in Children: Variations in Presentation and a Review of 25 Hips After Surgical Debridement.

INTRODUCTION: The septic arthritis of the hip (SAH) is one of the most common musculoskeletal infections occurring in pediatric populations requiring urgent intervention. This study discusses the myriad of clinical and radiological presentations of late-presenting SAH in children and the outcomes of surgical management. METHODS: After ethical approval, we did retrospective reviews of children treated for late-presenting SAH (after five days of symptoms). We excluded late cases with established sequelae. We recorded age, duration of symptoms, clinical evaluation, and radiographs. We evaluated the final results clinically and radiologically. RESULTS: Twenty-four patients with 25 hips were eligible for evaluation. At presentation, all had decreased or painful hip movements, but none had a fever. Radiographs revealed the following changes: hip dislocation (four), capital femoral slip (seven), proximal femur/neck osteomyelitis (six), pathological fractured neck femur (two), iliac osteomyelitis (two), and early arthritic changes (two). Hip arthrotomy was done in all cases. Frank pus was found in 21 (84%) cases. Cases with capital slip and fractured neck femur required fixation with two smooth K-wires. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated in three patients and tuberculosis in two cases. Clinical outcomes showed 14 patients with poor outcomes, eight with fair, and two with good. Avascular necrosis (AVN) of the femoral head was noted in 14 hips and complete femoral head resorption in nine. CONCLUSIONS: The late-presenting SAH in children has a myriad of presentations including dislocation and capital slip with unsatisfactory outcome. However, ongoing local infective processes may necessitate debridement. With limited salvage options available at the sequelae stage, awareness and training for early diagnosis and treatment may be the best way to improve the scenario. We recommend future multicenter randomized studies of predictive factors and indications of arthrotomy in late presenters.

Computational Approaches: A New Frontier in Cancer Research.

Cancer is a broad category of disease that can start in virtually any organ or tissue of the body when aberrant cells assault surrounding organs and proliferate uncontrollably. According to the most recent statistics, cancer will be the cause of 10 million deaths worldwide in 2020, accounting for one death out of every six worldwide. The typical approach used in anti-cancer research is highly time-consuming and expensive, and the outcomes are not particularly encouraging. Computational techniques have been employed in anti-cancer research to advance our understanding. Recent years have seen a significant and exceptional impact on anticancer research due to the rapid development of computational tools for novel drug discovery, drug design, genetic studies, genome characterization, cancer imaging and detection, radiotherapy, cancer metabolomics, and novel therapeutic approaches. In this paper, we examined the various subfields of contemporary computational techniques, including molecular docking, artificial intelligence, bioinformatics, virtual screening, and QSAR, and their applications in the study of cancer.

Assessment of Nutrition Status and Its Effect on Outcomes in Patients With Limb Injuries Using the Subjective Global Assessment as a Screening Tool.

Background Malnutrition in hospitalized patients is a significant problem. This study aimed to assess the utility of the Subjective Global Assessment (SGA) in predicting the association between serum biomarkers and malnutrition in patients with limb injuries as well as the impact of malnutrition on clinical and radiological bone healing. Methodology This prospective study included 93 patients with limb injuries. Basic demographic details, serum biomarker levels, nutritional status assessed using the SGA, and the correlation of the Radiological Union Shaft Tibia (RUST) score with nutrition status were assessed along with the secondary outcomes. Results According to the SGA, patients were classified into Group A (well-nourished), Group B (moderately malnourished), and Group C (severely malnourished). Serum biomarkers (albumin, hemoglobin, platelets, and total leucocyte count) were significantly higher in Group A than in Group B + C (p < 0.0001). The nutritional status of patients from admission up to six months in Group A was significantly higher (p < 0.0001) compared to Group B + C. The radiological healing according to the RUST score had a negative correlation with C-reactive protein and a positive correlation with various parameters at six months. Conclusions The serum biomarker levels and the clinical and radiological bone healing, as measured by the RUST scoring system, showed a positive correlation with the nutritional status of the patients. Malnutrition significantly increases the chance of developing complications such as wound infection, decubitus, and infected implants.

The Effect of Timing of Debridement and Surgical Intervention in Open Fractures on the Rate of Infection and Surgical Outcomes: A Prospective Study in a Tertiary Care Setup.

Introduction Open fractures remain one of the true orthopedic emergencies. Despite recent advances in orthopedic surgery, the management of compound fractures is still a challenge to an orthopedic surgeon. Open fractures are a result of high-speed injuries and are associated with several complications such as infections, non-unions, or sometimes an eventual amputation. Infection is the major problem associated with open fractures due to soft tissue damage, contamination, and neurovascular compromise. Presently, management of open fractures requires early aggressive debridement followed by limb salvage by definitive reconstruction or amputation, depending upon the extent and location of the injury. Early aggressive debridement of open fractures has always been the rule. However, it has been observed that open fractures managed even after six hours of injury fare well, and there are no definite guidelines available to decide the safe period of debridement following open fractures so as to prevent infection. The "six-hour rule" is a hotly debated topic with fervent perseverance of this dogma despite a gross lack of support from the literature. Objective The objective of this study was to analyze the relationship between the timing of operation/debridement on infection rates in open fractures, particularly if surgery is performed after six hours. Methods This is a prospective study of 124 patients (R=5-75 years) presenting with open fractures to the outpatient department (OPD) and emergency section of a tertiary care hospital from January 2019 to November 2020. Patients were divided into four groups based on the time to operation/debridement: groups A, B, C, and D, with patients operated within six hours, six to 12 hours, 12-24 hours, and 24-72 hours after injury, respectively. Infection rates were obtained based on the above data. ANOVA was applied using SPSS 20 software (IBM Inc., Armonk, New York). Results This study concludes that the infection rate for fractures treated in less than six hours was 18.75%; in the six to 12 hours group, it was 18.50%, and in the 12-24 hours group, it was 14.28%. The infection rate increased to 38.8% if surgery was performed after 24 hours of injury. On statistical analysis, the time to debridement was not found to be a significant factor. The infection rate in Gustilo-Anderson classification compound grade I was 2.7%, grade II 9.8%, grade IIIA 45%, and grade IIIB 61%. Also, in this study, the union rate in grade I was 97.22%, grade II 96.07%, grade IIIA 85%, and grade IIIB 66.66%. Thus, the degree of wound contamination and compounding gives a prognostic indication regarding the final outcome of the compound fracture. Conclusion Time to debridement is not a significant factor in the management of compound fractures, and these fractures can be safely debrided up to 24 hours after injury. Gustilo and Anderson's classification provides a prognostic indicator of the outcome of a compound fracture. Infection rates and non-union rates increase with increasing grades of compound fractures.

Inhibition and disintegration of Bacillus subtilis biofilm with small molecule inhibitors identified through virtual screening for targeting TasA(28-261), the major protein component of ECM.

Microbial biofilms have been recognized for a vital role in antibiotic resistance and chronic microbial infections for 2-3 decades; still, there are no 'anti-biofilm drugs' available for human applications. There is an urgent need to develop novel 'anti-biofilms' therapeutics to manage biofilm-associated infectious diseases. Several reports have suggested that targeting molecules involved in quorum sensing or biofilm-specific transcription may inhibit biofilm formation. However, the possibility of targeting other vital components of microbial biofilms, especially the extracellular matrix (ECM) components, has remained largely unexplored. Here we report targeting TasA(28-261), the major proteinaceous component of Bacillus subtilis ECM with two small molecule inhibitors (lovastatin and simvastatin) identified through virtual screening and drug repurposing, resulted in complete inhibition of biofilm. In molecular docking and dynamics simulation studies, lovastatin was observed to make stable interactions with TasA(28-261), whereas the simvastatin - TasA(28-261) interactions were relatively less stable. However, in subsequent in vitro studies, both lovastatin and simvastatin successfully inhibited B. subtilis biofilm formation at MIC values of < 10 µg/ml. Besides, these potential inhibitors also caused the disintegration of pre-formed biofilms. Results presented here provide 'proof of concept' for the hypothesis that targeting the extracellular matrix's vital component(s) could be one of the most efficient approaches for inhibiting microbial biofilms and disintegrating the pre-formed biofilms. We propose that a similar approach targeting ECM-associated proteins with FDA-approved drugs could be implemented to develop novel anti-biofilm therapeutic strategies against biofilm-forming chronic microbial pathogens.Communicated by Ramaswamy H. Sarma.

Validating Confined Flame Noise Simulation Using External Sensor.

Advancements in lean premixed combustion have increased the efficiency and reduced the amount of greenhouse gas emissions, but they have led to increased noise emissions due to higher turbulence and mixing fluctuations. This study used an external sensor (microphone) to validate the simulation of the combustion noise of a confined space. An experimental facility with a laboratory-scale furnace was used to carry out the measurement, and the simulation of the confined flame noise was conducted in OpenFOAM. The simulation utilized the Partially Stirred Reactor (PaSR) and a hybrid computational aeroacoustics (CAA) approach using the large eddy simulation (LES)/the Ffwocs Williams-Hawkings (FWH) method. Additionally, unsteady Reynolds-averaged Navier-Stokes (URANS)/the FWH method was tested for a comparison with the LES prediction. A sensor which was placed outside the enclosure for ease of access was then used to validate the results of the numerical model. The sensor data agreed with the LES/FWH results including the amplitude and frequency of the primary combustion peak and the overall sound pressure level (OASPL). This suggested that a sensor which was placed outside the enclosure could serve as a validation tool for the simulation of the confined flames despite the sound reflections from the walls.

2-Pyridin-4-yl-methylene-beta-boswellic Acid-A Potential Candidate for Targeting O6-Methylguanine-DNA Methyltransferase Epi-transcriptional Reprogramming in KRAS G13D-Microsatellite Stable, G12V-Microsatellite Instable Mutant Colon Cancer.

PMBA (2-Pyridin-4-yl-methylene-beta-boswellic acid), screened from among the 21 novel series of semisynthetic analogues of ß-boswellic acid, is being presented as a lead compound for integrative management of KRAS mutant colorectal cancer (CRC), upon testing and analysis for its anticancerous activity on a panel of NCI-60 cancer cell lines and in vivo models of the disease. PMBA (1.7-29 µM) exhibited potent proliferation inhibition on the cell lines and showed sensitivity in microsatellite instability and microsatellite stable (GSE39582 and GSE92921) subsets of KRAS gene (Kirsten rat sarcoma viral oncogene homolog)-mutated colon cell lines, as revealed via flow cytometry analysis. A considerable decrease in mitogen-activated protein kinase pathway downstream effectors was observed in the treated cell lines via the western blot and STRING (Search tool for the retrieval of interacting genes/proteins) analysis. PMBA was further found to target KRAS at its guanosine diphosphate site. Treatment of the cell lines with PMBA showed significant reduction in MGMT promoter methylation but restored MGMT (O6-methylguanine-DNA methyltransferase) messenger ribonucleic acid expression via significant demethylation of the hypermethylated CpG (Cytosine phosphate guanine) sites in the MGMT promoter. A significant decrease in dimethylated H3K9 (Dimethylation of lysine 9 on histone 3) levels in the MGMT promoter in DNA hypo- and hypermethylated HCT-116G13D and SW-620G12V cells was observed after treatment. In the MNU (N-methyl-N-nitrosourea)-induced CRC in vivo model, PMBA instillation restricted and repressed polyp formation, suppressed tumor proliferation marker Ki67 (Marker of proliferation), ablated KRAS-associated cytokine signaling, and decreased mortality. Clinical trial data for the parent molecule revealed its effectiveness against the disease, oral bioavailability, and system tolerance. Comprehensively, PMBA represents a new class of KRAS inhibitors having a therapeutic window in the scope of a drug candidate. The findings suggest that the PMBA analogue could inhibit the growth of human CRC in vivo through downregulation of cancer-associated biomarkers as well as reactivate expression of the MGMT gene associated with increased H3K9 acetylation and H3K4 methylation with facilitated transcriptional activation, which might be important in silencing of genes associated with upregulation in the activity of KRAS.

Role of Artificial Intelligence in Cancer Diagnosis and Drug Development.

Cancer is a vast form of the disease that can begin in almost any organ or tissue of the body when abnormal cells grow uncontrollably and attack nearby organs. The traditional approaches to cancer diagnosis and drug development have certain limitations, and the outcomes achieved through the traditional approaches applied to cancer diagnosis and drug development are not quite promising. Artificial intelligence is not new to the medical research sector. AI-based algorithms hold great potential for identifying mutations and abnormal cell division at the initial stage of cancer. Advanced researchers are also focusing on bringing AI to clinics in a safe and ethical manner. Early cancer detection saves lives and is critical in the fight against the disease. As a result, as part of earlier detection, computational approaches such as artificial intelligence have played a significant role in cancer diagnosis and drug development.

Complex Metacarpophalangeal Joint Dislocation of the Index Finger in Pediatric Age: A Case Report and Review of Literature.

Introduction: Metacarpophalangeal (MCP) joint dislocation is a rare occurrence in the pediatric population. A few case reports are available globally. Understanding of anatomy of the MCP joint is necessary for the surgical approach. We report a case of complex volar MCP joint dislocation in a pediatric patient. Case Report: We report a 13-year-old male child with traumatic dislocation of the MCP joint of the index finger. It was a complex volar dislocation that was surgically treated via a dorsal approach. On 6-month follow-up, child regained an almost normal range of motion at the MCP joint with a good functional outcome. Conclusion: Complex MCP joint dislocation often needs open reduction. Out of the two described surgical approaches, we preferred the dorsal approach which allowed proper visualization of the volar plate and avoided risks to neurovascular bundles. Early management and early mobilization provide good functional outcomes.

Open Reduction with Femoral Shortening, Derotation Osteotomy, and Acetabuloplasty in a Walking Age Developmental Dysplasia of Hip - A Surgical Video Technique.

Introduction: It is very common for pediatric orthopedic surgeon to encounter developmental dysplasia of hip (DDH) in walking age, especially in developing countries. The conservative options of management are almost over by this age and most require open reduction (OR) with various adjunct procedures. The most preferred approach for OR in this age group is anterior Smith-Peterson approach to hip joint. These neglected cases also require femoral shortening ± derotation osteotomy and acetabuloplasty. Case Report: In this surgical video technique, we demonstrate OR + femoral shortening and derotation osteotomy and acetabuloplasty, step by step, in a neglected, walking age DDH in a 3-year-old child. We hope that the detailed demonstration and tricks at various surgical steps will benefit our readers and viewers. Conclusion: Step-wise surgical execution as per demonstrated technique makes the procedure easily reproducible with fairly good outcomes. In this case example, with demonstrated surgical technique, we were able to achieve a good outcome at short-term follow-up.

Proximal Fibular Osteotomy for Medial Joint Osteoarthritis of the Knee: A Prospective Cohort Study.

Background and objective Osteoarthritis (OA) is a polyarticular disease that most commonly afflicts the knee joint. Established operative treatment options for medial joint OA of the knee include high tibial osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty. Proximal fibular osteotomy (PFO) is a relatively new procedure for treating medial joint OA of the knee. The objective of this study was to describe the functional and radiological outcomes at one year in patients undergoing PFO for medial joint OA of the knee. Materials and methods The study included 21 patients with medial joint OA of the knee who underwent PFO. Visual analog scale (VAS) score, medial to lateral knee joint space ratio (ML ratio), Kellgren-Lawrence (KL) grade, and the American Knee Society Score (AKSS) (clinical and functional) were recorded preoperatively. VAS score, ML ratio, and AKSS (clinical and functional) were documented again at the three-month and one-year follow-ups. Results The mean age of the patients was 58.85 ±6.94 years; 12 (57.1%) were female and nine (42.9%) were males. The mean VAS score for pain decreased from 7.86 ±0.66 at baseline to 5.14 ±1.15 at three months (p<0.001) and 3.78 ±1.26 at one year (p<0.001). The mean clinical AKSS was 56.49 ±6.95 at baseline, which increased to 63.41 ±6.20 at three months (p<0.001) and 72.71 ±9.87 at one year (p<0.001). The mean functional AKSS at baseline was 48.24 ±14.31, which increased to 60.10 ±14.81 at three months (p<0.001) and 71.46 ±15.18 at one year (p<0.001). The mean ML ratio at baseline was 0.33 ±0.19, which increased to 0.41 ±0.20 at three months (p<0.01) and 0.51 ±0.22 at one year (p<0.001). Conclusion In patients who undergo PFO for OA of the knee, improvements in VAS score for pain, AKSS (functional and clinical), and ML ratio were observed to be maintained for a period of one year postoperatively.

Effective ventilation and air disinfection system for reducing coronavirus disease 2019 (COVID-19) infection risk in office buildings.

During the COVID-19 pandemic, an increasing amount of evidence has suggested that the virus can be transmitted through the air inside buildings. The ventilation system used to create the indoor environment would facilitate the transmission of the airborne infectious diseases. However, the existing ventilation systems in most buildings cannot supply sufficient clean outdoor air for diluting the virus concentration. To reduce the airborne infection risk and minimize energy consumption, especially in existing buildings with well-mixed ventilation systems, this investigation used an ultraviolet-C (UV-C) air disinfection device (Rheem's third generation products, RM3) with 99.9% disinfection efficiency to clean air carrying the COVID-19 virus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) which could help promote environmental sustainability and create healthy cities. This investigation assessed the impact of the RM3 UV-C units on the infection risk, the number of RM3 UV-C units required, and the strategy for decreasing the infection risk, with the use of computational-fluid-dynamics (CFD) numerical simulations. An actual office building with a combination of individual offices and workstations was selected as an example for the research. According to the numerical results, the best strategy would be to use a combination of 100% outside air and UV-C in heating, ventilation and air-conditioning (HVAC) ducts with air disinfected by the RM3 UV-C units. The infection risk in the office building could thus be reduced to a negligible level. These findings could provide theoretical basis and engineering application basis for COVID-19 epidemic prevention and control.

Outcome of total hip arthroplasty in patients with failed open reduction and internal fixation of acetabular fractures.

BACKGROUND: The problem of failed acetabulum fracture fixation is increasing due to increased incidence of high-velocity injury and a large number of patients are being operated on in the past few years. Limited evidence is available regarding results of Total hip arthroplasty (THA) in patients with failed acetabulum fracture fixation surgery. We assessed the clinical, radiological and postoperative complications. Besides this, we also evaluated functional outcome and quality of life following THA in failed open reduction and internal fixation of acetabular fractures. METHOD: The current retrospective study was performed at the tertiary center from 2015 to 2020. Eighteen patients of failed acetabulum fracture fixation surgery (14 males and 4 females) were included with a mean follow-up period of 2.4 years. Postero-lateral approach was done in all cases. Clinico-radiological outcome, functional outcomes were recorded according to Harris Hip score (HHS) and quality of life was assessed by using the 12-Item Short Form Health Survey (SF-12) score. Postoperative complications were also assessed. RESULTS: The age of patients ranged from 20 years to 68 years with a mean age of 44.7 years. 16 of the patients (88.9%) had a united acetabular fracture while 2 of them (11.1%) presented with un-united acetabular fracture. The THA implant was found to be stable in all 18 cases. The Harris Hip score of the study ranged from 82 to 95 with a mean of 89.72 ± 4.24 while the SF-12 score ranged from 40.0 to 49.4 with a mean of 44.29 ± 2.95. Out of 18 cases, 11 (61.1%) returned with excellent outcomes while the rest 7 (38.9%) returned with good outcomes as per Harris Hips score criteria. The correlation and regression analysis shows between HHS and SF-12 was positive and statistically significant (r = 0.592, p = 0.010). CONCLUSION: THA in patients with failed acetabulum fracture fixation surgery provides a reliable option with satisfactory outcomes along with a better quality of life.

The Validation of Clinical Examination and MRI as a Diagnostic Tool for Cruciate Ligaments and Meniscus Injuries of the Knee Against Diagnostic Arthroscopy.

BACKGROUND: This study was conducted to compare the accuracy of MRI findings and clinical examination of ligamentous and meniscal injuries of the knee, taking arthroscopy as a standard diagnostic tool in knee injuries.  Methods: All patients with knee injuries attending the outpatient department or emergency of our hospital underwent clinical examination. Out of them, 60 patients with knee injuries were subjected to clinical examination, MRI, and then arthroscopy. The findings of these diagnostic tools in respect to the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and meniscus injuries were validated, compared, and analyzed using various statistical tools. The accuracy, sensitivity, negative predictive value (NPV), positive predictive value (PPV), and specificity were calculated and an agreement between various tests was established using kappa statistics. RESULTS: The accuracy of clinical examination in our study was 88% for ACL tears, 85% for meniscal tears, and 100% for PCL tears. The kappa measure of agreement between arthroscopy and clinical finding and MRI for ACL was 0.610 and 0.698, respectively, which was statistically significant. MRI (98.1) was found to be a more sensitive test for detecting ACL injury than clinical examination (90.4%) resulting in higher diagnostic accuracy (98.3%), while diagnostic accuracy of clinical examination and MRI was found to be 100% for PCL injuries. Hence, MRI is an excellent screening tool for ligamentous and meniscal injuries of the knee joint. We can avoid diagnostic arthroscopy in patients with knee injuries having equivocal clinical and MRI examinations and can proceed for therapeutic arthroscopy to deal with such injuries.  Conclusions: For the assessment of ligamentous and meniscal injuries, MRI is an accurate and noninvasive modality. It can be used as a first-line investigation but arthroscopy remains the gold standard.

Tandem MS-Based Metabolite Profiling of 19,20-Epoxycytochalasin C Reveals the Importance of a Hydroxy Group at the C7 Position for Biological Activity.

Seven cytochalasins, 19,20-epoxycytochalasin N, cytochalasin P1, deacetyl 19,20-epoxycytochalasin C, 19,20-epoxycytochalasin D, 19,20-epoxycytochalasin C, cytochalasin D, and cytochalasin C, were isolated from a fungal (Rosellinia sanctae-cruciana) crude extract. A cytotoxicity assay (sulforhodamine B) was performed on a series of cancer cell lines: HT-29, A-549, PC-3, HCT-116, SW-620, and MCF-7. Simultaneously, the liquid chromatography-mass spectrometry (LC-MS)/MS profile of 19,20-epoxycytochalasin C-treated cell lines revealed that 19,20-epoxycytochalasin C (m/z 524.25) oxidized to a metabolite of m/z 522.25 Da (-2 Da (-2H) from 19,20-epoxycytochalasin C). Further chemical oxidation of 19,20-epoxycytochalasin C using the Dess-Martin reagent produced an identical metabolite. It has been noticed that the parent molecule (19,20-epoxycytochalasin C) showed an IC50 of 650 nM (on HT-29), whereas for the oxidized metabolite (m/z 522.24) of 19,20-epoxycytochalasin C, the IC50 was >10 µM. It is clear that the parent molecule had 16 times higher cytotoxic potential as compared to the oxidized metabolite. The spectroscopic investigation indicated that the oxidation of the hydroxyl (-OH) group occurred at the C7 position in 19,20-epoxycyctochalsin C and led to the inactivation of 19,20-epoxycytochalasin C. Further, cell cycle analysis and histopathological evidence support the findings, and CDK2 could be a possible target of 19,20-epoxycyctochalasin C.

Computational investigation for modeling the protein-protein interaction of TasA(28-261)-TapA(33-253): a decisive process in biofilm formation by Bacillus subtilis.

Biofilms have a significant role in microbial persistence, antibiotic resistance, and chronic infections; consequently, there is a pressing need for development of novel "anti-biofilm strategies." One of the fundamental mechanisms involved in biofilm formation is protein-protein interactions of "amyloid-like proteins" (ALPs) in the extracellular matrix. Such interactions could be potential targets for development of novel anti-biofilm strategies; therefore, assessing the structural features of these interactions could be of great scientific value. Characterization of structural features the of protein-protein interaction with conventional structure biology tools including X-ray diffraction and nuclear magnetic resonance is technically challenging, expensive, and time-consuming. In contrast, modeling such interactions is time-efficient and economical, and might provide deeper understanding of structural basis of interactions. Although it is often acknowledged that molecular modeling methods have varying accuracy, their careful implementation with supplementary verification methods can provide valuable insight and directions for future studies. With this reasoning, during the present study, the protein-protein interaction of TasA(28-261)-TapA(33-253) (which is a decisive process for biofilm formation by Bacillus subtilis) was modeled using in silico approaches, viz., molecular modeling, protein-protein docking, and molecular dynamics simulations. Results obtained here identified amino acid residues present within intrinsically disordered regions of both proteins to be critical for interaction. These results were further supported with principal component analyses (PCA) and free energy landscape (FEL) analyses. Results presented here represent novel finding, and we hypothesize that amino acid residues identified during the present study could be targeted for inhibition of biofilm formation by B. subtilis.

Exploration of docetaxel palmitate and its solid lipid nanoparticles as a novel option for alleviating the rising concern of multi-drug resistance.

Docetaxel (DTX), a widely prescribed anticancer agent, is now associated with increased instances of multidrug resistance. Also, being a problematic BCS class IV drug, it poses challenges for the formulators. Henceforth, it was envisioned to synthesize an analogue of DTX with a biocompatible lipid, i.e., palmitic acid. The in-silico studies (molecular docking and simulation) inferred lesser binding of docetaxel palmitate (DTX-PL) with P-gp vis-à-vis DTX and paclitaxel, indicating it to be a poor substrate for P-gp efflux. Solid lipid nanoparticles (SLNs) of the conjugate were prepared using various lipids, viz. palmitic acid, stearic acid, cetyl palmitate and glyceryl monostearate. The characterization studies for the nanocarrier were performed for the surface charge, drug payload, micromeritics, release pattern of drug and surface morphology. From the cytotoxicity assays on resistant MCF-7 cells, it was established that the new analogue offered substantially decreased IC50 to that of DTX. Further, apoptosis assay also corroborated the results obtained in IC50 determination wherein, SA-SLNs showed the highest apoptotic index than free DTX. The conjugate not only enhanced the solubility but also offered lower plasma protein binding and improved pharmacokinetic and pharmacodynamic effect for DTX loaded SA-SLNs in apt animal models, and lower affinity to P-gp efflux. The studies provide preliminary evidence and a ray of hope for a better candidate in its nano version for safer and effective cancer chemotherapy.

Identification of novel small molecule non-peptidomimetic inhibitor for prolyl oligopeptidase through in silico and in vitro approaches.

Prolyl oligopeptidase (POP) enzyme has been studied for various disorders, viz. Schizophrenia, Alzheimer's, Parkinson's, Depression, Inflammation, etc., for three decades, but no drug has passed through the clinical trials, possibly because of indigent pharmacokinetics. This might have been a result of similar structures of drug candidates. This study aimed at identifying novel small non-peptidomimetic inhibitors for POP enzyme that could serve as a lead for developing newer drugs. Structure-based virtual screening of molecules of MolMall database was conducted on the POP enzyme (PDB ID 3DDU) to identify potential hits. The hits identified were subjected to computational pharmacokinetic screening followed by molecular mechanics/generalized Born and surface area studies to estimate the binding free energy of the docked complexes. After that, nine hits were selected and tested for POP inhibitory activity, among which one compound MM 4 was found to be most potent with EC50 of 100 µM. Compound MM 4 was further subjected to molecular dynamics simulations to study the overall stability of the ligand-protein complex. The compound interacted strongly with catalytic amino acid Arg643 by forming salt and water bridges; it also interacted well with amino acids Phe173, Arg252 and Met235. This study provides a lead molecule for further development of POP inhibitors.Communicated by Ramaswamy H. Sarma.