Benzimidazole derivatives as tubulin polymerization inhibitors: Design, synthesis and in vitro cytotoxicity studies.

A new class of benzimidazole derivatives as tubulin polymerization inhibitors has been designed and synthesized in this study. The in vitro anticancer profile of the developed molecules was reconnoitred on selected human cancer cells. The highest cytotoxicity was illustrated by compounds 7n and 7u with IC50 values ranging from 2.55 to 17.89 µM with specificity toward SK-Mel-28 cells. They displayed 5-fold less cytotoxicity towards normal rat kidney epithelial NRK52E cells, which implies that they are not harmful to normal, healthy cells. The cellular staining procedures like AO/EB, DCFDA, and DAPI were applied to comprehend the inherent mechanism of apoptosis which displayed nuclear and morphological alterations. The Annexin V binding and JC-1 studies were executed to evaluate the extent of apoptosis and the decline in mitochondrial transmembrane potential in SK-Mel-28 cell lines. Compound 7n dose-dependently arrested the G2/M phase of the cell cycle and the target-based outcomes proposed tubulin polymerization inhibition by 7n (IC50 of 5.05±0.13 µM). Computational studies were also conducted on the tubulin protein (PDB ID: 3E22) to investigate the stabilized binding interactions of compounds 7n and 7u with tubulin, respectively.

The Role of Social Media in Building Pandemic Resilience in an Urban Community: A Qualitative Case Study.

This paper explores the influence of social media in fostering resilience within an urban spatial context, specifically in Bangalore, India, during the COVID-19 lockdown, a period marked by a surge in digital communication due to movement restrictions. To control the rapid spread of the virus, over 1.38 billion people were given stay-at-home orders by the government of India during the onset of the pandemic. The restrictions in movement forced individuals to shift to online modes of connection and communication. As the field of digital epidemiology, that is, the use of digital tools and data to understand and improve health took center stage during the pandemic, the focus shifted towards the social media landscape, which is often associated with its negative aspects, such as misinformation. However, this paper delves into social media's potential to build resilience on a local scale, particularly given its increased usage during the pandemic. Through in-depth online interviews with eight urban residents, we conducted a thematic analysis to understand social media's role during the lockdown. Results indicate that social media facilitated effective information exchange and fostered a sense of community. Furthermore, it engendered an environment conducive to prosocial behavior, a known resilience amplifier. We also highlight the importance of baseline context regarding the users directly engaged in social media data generation with respect to digital epidemiology analytics tools for large-scale social media data and the need for qualitative input feeding into their design. Our study highlights the need for a balanced perspective on social media use in times of crisis, recognizing its potential to boost community resilience in an urban setting, and further enriching digital epidemiology approaches.

The role of serotonin inhibition within the treatment of carcinoid syndrome.

Carcinoid syndrome is the most frequent hormonal complication associated with neuroendocrine neoplasms. It was first reported in 1954, and the classical symptoms are diarrhoea, flushing and abdominal pain. It is caused by the secretion of several vasoactive substances, the most prominent being serotonin, which play a pathophysiological role in the clinical symptoms which characterise carcinoid syndrome. Therefore, the focus of carcinoid syndrome treatment is to reduce serotonin production and hence improve the patient's quality of life. There are a variety of management options for carcinoid syndrome including medical, surgical and loco-regional interventional radiological procedures. The most widely used are somatostatin analogues with three clinically approved drugs: lanreotide and octreotide (first-generation) and pasireotide (second-generation). Both everolimus and interferon used in combination with octreotide have shown significant reduction in urinary 5-hydroxyindoleacetic acid compared to octreotide alone. Telotristat ethyl has been increasingly utilised for patients with symptoms despite taking somatostatin analogues. It has also been shown to have a significant improvement in bowel movement frequency which was associated with a significant improvement in quality of life. Peptide receptor radionuclide therapy has proven symptomatic improvement in patients with uncontrolled symptoms. Chemotherapy is primarily reserved for patients with high proliferation tumours, with limited research on the efficacy in reducing symptoms. Surgical resection remains the optimal treatment due to being the only one that can achieve a cure. Liver-directed therapies are considered in patients where curative resection is not possible. There are therefore numerous different therapies. This paper describes the pathophysiology and therapy of carcinoid syndrome.

Triazolo-linked benzimidazoles as tubulin polymerization inhibitors and DNA intercalators: Design, synthesis, cytotoxicity, and docking studies.

A simple "click" protocol was employed in the quest of synthesizing 1,2,3-triazole-linked benzimidazoles as promising anticancer agents on various human cancer cell lines such as A549, HCT116, SK-Mel-28, HT-29, and MCF-7. Compound 12j demonstrated significant cytotoxic potential towards SK-Mel-28 cancer cells (IC50 : 4.17 ± 0.09 µM) and displayed no cytotoxicity (IC50 : > 100 µM) against normal human BEAS-2B cells inferring its safety towards normal healthy cells. Further to comprehend the underlying apoptosis mechanisms, AO/EB, dichlorodihydrofluorescein diacetate (DCFDA), and 4',6-diamidino-2-phenylindole (DAPI) staining were performed, which revealed the nuclear and morphological alterations. Compound 12j displayed impairment in cellular migration and inhibited colony formation. The annexin V binding assay and JC-1 were implemented to evaluate the scope of apoptosis and the loss of the mitochondrial transmembrane potential in SK-Mel-28 cells. Cell-cycle analysis revealed that compound 12j arrested the cells at the G2/M phase in a dose-dependent manner. Target-based assays established the inhibition of tubulin polymerization by 12j at an IC50 value of 5.65 ± 0.05 µM and its effective binding with circulating tumor DNA as a DNA intercalator. The detailed binding interactions of 12j with tubulin and DNA were examined by docking studies on PDB ID: 3E22 and DNA hexamer (PDB ID: 1NAB), respectively.

Theaflavin 3-gallate inhibits the main protease (Mpro) of SARS-CoV-2 and reduces its count in vitro.

The main protease (Mpro) of SARS-CoV-2 has been recognized as an attractive drug target because of its central role in viral replication. Our previous preliminary molecular docking studies showed that theaflavin 3-gallate (a natural bioactive molecule derived from theaflavin and found in high abundance in black tea) exhibited better docking scores than repurposed drugs (Atazanavir, Darunavir, Lopinavir). In this study, conventional and steered MD-simulations analyses revealed stronger interactions of theaflavin 3-gallate with the active site residues of Mpro than theaflavin and a standard molecule GC373 (a known inhibitor of Mpro and novel broad-spectrum anti-viral agent). Theaflavin 3-gallate inhibited Mpro protein of SARS-CoV-2 with an IC50 value of 18.48 ± 1.29 µM. Treatment of SARS-CoV-2 (Indian/a3i clade/2020 isolate) with 200 µM of theaflavin 3-gallate in vitro using Vero cells and quantifying viral transcripts demonstrated reduction of viral count by 75% (viral particles reduced from Log106.7 to Log106.1). Overall, our findings suggest that theaflavin 3-gallate effectively targets the Mpro thus limiting the replication of the SARS-CoV-2 virus in vitro.

Design, synthesis of DNA-interactive 4-thiazolidinone-based indolo-/pyrroloazepinone conjugates as potential cytotoxic and topoisomerase I inhibitors.

With the rising cancer incidence and mortality globally, there is a prerequisite for effective design strategies towards the discovery of newer small molecular entities in chemotherapy. Hence, a series of new thiazolidinone-based indolo-/pyrroloazepinone conjugates was designed, synthesized via molecular hybridization, and evaluated for their in vitro cytotoxicity potential and DNA topoisomerase I and II inhibition. Among this series, conjugate 11g emerged as the most active compound with an IC50 value of 1.24 µM against A549 and 3.02-10.91 µM in the other tested cancer cell lines. Gratifyingly, 11g displayed 43-fold higher selectivity towards A549 cancer cells as compared to the non-cancer cells. Subsequently, conjugate 12g also demonstrated significant cytotoxicity against SK-MEL-28 cells. Basing the in vitro cytotoxicity results, SAR was established. Later, the conjugates 11g and 12g were further evaluated for their apoptosis-inducing ability, which was quantified by flow cytometric analysis, DNA-binding, Topo I inhibitory activity and IC50 value calculation. Molecular modeling studies provided profound insights about the binding nature of these compounds with DNA-Topo I complex. In silico ADME/T and prediction studies corroborated the drug-likeness of the two investigated compounds. TOPKAT toxicity profiling studies demonstrated the compounds' safety in many animal models with a minimal toxicological profile. Encouraging results obtained from in vitro and in silico studies could put this series of conjugates at the forefront of cancer drug discovery.

Synthesis of indolo/pyrroloazepinone-oxindoles as potential cytotoxic, DNA-intercalating and Topo I inhibitors.

A series of 17 indolo/pyrroloazepinone-oxindole conjugates was synthesized and evaluated for their antiproliferative activity against a panel of selected human cancer cell lines including A549 (lung cancer), HCT116 (colon cancer), MCF7 (breast cancer), and SK-MEL-28 (melanoma). Among the synthesized molecules (14a-m and 15a-d), compound 14d displayed remarkable activity against A549, HCT116 and SK-MEL-28 cells with IC50 values < 4 µM with the best cytotoxicity and a 13-fold selectivity towards lung cancer cells (IC50 value of 2.33 µM) over the normal rat kidney cells (NRK). Further, 14d-mediated apoptosis affected the cellular and nuclear morphology of the cancer cells in a dose-dependent manner. Wound healing and clonogenic assays inferred the inhibition of cell growth and migration. Target-based studies of compound 14d corroborated its DNA-intercalative capability and Topo I inhibitory activity which have been fortified by molecular modeling studies. Finally, the drug-likeness of the potent compound was determined by performing in silico ADME/T prediction studies.

PRC2 Regulated Atoh8 Is a Regulator of Intestinal Microfold Cell (M Cell) Differentiation.

Intestinal microfold cells (M cells) are a dynamic lineage of epithelial cells that initiate mucosal immunity in the intestine. They are responsible for the uptake and transcytosis of microorganisms, pathogens, and other antigens in the gastrointestinal tract. A mature M cell expresses a receptor Gp2 which binds to pathogens and aids in the uptake. Due to the rarity of these cells in the intestine, their development and differentiation remain yet to be fully understood. We recently demonstrated that polycomb repressive complex 2 (PRC2) is an epigenetic regulator of M cell development, and 12 novel transcription factors including Atoh8 were revealed to be regulated by the PRC2. Here, we show that Atoh8 acts as a regulator of M cell differentiation; the absence of Atoh8 led to a significant increase in the number of Gp2+ mature M cells and other M cell-associated markers such as Spi-B and Sox8. In vitro organoid analysis of RankL treated organoid showed an increase of mature marker GP2 expression and other M cell-associated markers. Atoh8 null mice showed an increase in transcytosis capacity of luminal antigens. An increase in M cell population has been previously reported to be detrimental to mucosal immunity because some pathogens like orally acquired prions have been able to exploit the transcytosis capacity of M cells to infect the host; mice with an increased population of M cells are also susceptible to Salmonella infections. Our study here demonstrates that PRC2 regulated Atoh8 is one of the factors that regulate the population density of intestinal M cell in the Peyer's patch.

Polycomb Repressive Complex 2 Regulates Genes Necessary for Intestinal Microfold Cell (M Cell) Development.

BACKGROUND & AIMS: Microfold cells (M cells) are immunosurveillance epithelial cells located in the Peyer's patches (PPs) in the intestine and are responsible for monitoring and transcytosis of antigens, microorganisms, and pathogens. Mature M cells use the receptor glycoprotein 2 (GP2) to aid in transcytosis. Recent studies have shown transcription factors, Spi-B and SRY-Box Transcription Factor 8 (Sox8). are necessary for M-cell differentiation, but not sufficient. An exhaustive set of factors sufficient for differentiation and development of a mature GP2+ M cell remains elusive. Our aim was to understand the role of polycomb repressive complex 2 (PRC2) as an epigenetic regulator of M-cell development. Estrogen-related-receptor γ (Esrrg), identified as a PRC2-regulated gene, was studied in depth, in addition to its relationship with Spi-B and Sox8. METHODS: Comparative chromatin immunoprecipitation and global run-on sequencing analysis of mouse intestinal organoids were performed in stem condition, enterocyte conditions, and receptor activator of nuclear factor κ B ligand-induced M-cell condition. Esrrg, which was identified as one of the PRC2-regulated transcription factors, was studied in wild-type mice and knocked out in intestinal organoids using guide RNA's. Sox8 null mice were used to study Esrrg and its relation to Sox8. RESULTS: chromatin immunoprecipitation and global run-on sequencing analysis showed 12 novel PRC2 regulated transcription factors, PRC2-regulated Esrrg is a novel M-cell-specific transcription factor acting on a receptor activator of nuclear factor κB ligand-receptor activator of nuclear factor κB-induced nuclear factor-κB pathway, upstream of Sox8, and necessary but not sufficient for a mature M-cell marker of Gp2 expression. CONCLUSIONS: PRC2 regulates a significant set of genes in M cells including Esrrg, which is critical for M-cell development and differentiation. Loss of Esrrg led to an immature M-cell phenotype lacking in Sox8 and Gp2 expression. Transcript profiling: the data have been deposited in the NCBI Gene Expression Omnibus database (GSE157629).

Outcomes in techniques of valve sparing aortic root replacement: A systematic review and meta-analysis.

OBJECTIVE: To compare clinical outcomes of reimplantation versus remodeling in patients undergoing valve-sparing aortic root replacement (VSRR) surgery. METHOD: Electronic database search at PubMed, Scopus, Embase, Ovid, and Google scholar was performed from inception to January 2020. Primary outcomes were aortic valve (AV) reintervention and postoperative grade of aortic insufficiency (AI) while secondary outcomes were 30-day mortality, reoperation for bleeding, and operative times. RESULTS: A total of 21 articles met the inclusion criteria. A total of 1283 patients had reimplantation while 1150 had remodeling. No difference in preoperative demographics was noted except reimplantation patients were younger (48 ± 16 vs. 56 ± 15 years; p < .00001). The cardiopulmonary bypass and aortic cross-clamp times were shorter in the remodeling cohort (168 ± 38 vs. 150 ± 37 min; p = .0001 and 133 ± 31 vs. 112 ± 30 min; p = .0002, respectively). No difference in concomitant total arch surgery (14% in reimplantation vs. 15% in remodeling; p = .53). Postoperatively, there were similar stroke rates (3% in both cohorts; p = .54), rates of reoperation for bleeding (9% in reimplantation vs. 12% in remodeling; p = .88), and 30-day mortality (3% in reimplantation vs. 4% in remodeling; p = .96). No difference in early AV reintervention (1% in reimplantation vs. 2% in remodeling; p = .07), and late AV reintervention (4% in reimplantation vs. 7% in remodeling; p = .07). The AI of +2 grade was significantly lower in the reimplantation cohort (5% vs. 8%; p = .01). CONCLUSION: Our study shows comparable clinical outcomes between both techniques. The practice of each technique is largely center and surgeon dependent. Larger sample size cohorts with minimal confounding factors are required to confirm the above findings.

Optimizing outcomes in infective endocarditis: A comprehensive literature review.

BACKGROUND: Despite being rare, infective endocarditis (IE) is a life-threatening disease with poor prognosis. New diagnostic and therapeutic strategies are emerging; however, predisposing factors and microbiology of the disease are also changing with time. Because of this, there has been a lack of reduction in the disease's incidence and new challenges for clinicians have arisen such as an increasingly aging population and growing antimicrobial resistance. AIMS: In this paper, we aim to provide an overview of the changing trends in IE, current diagnosis, and management strategies, as well as the emerging role of the infective endocarditis teams in the care of patients with this disease. MATERIALS & METHODS: A comprehensive electronic search was done utilizing PubMed, Ovid, SCOPUS, Embase and google scholar. The search terms included 'Endocarditis', 'IE', 'Infection', 'Vegetation', 'Duke criteria', 'native valve infection', 'prosthetic valve', 'valve infection', 'endocarditis outcome' and 'endocarditis bacteriology'. The references of the identified articles were then searched for any potential articles that can be included. The inclusion criteria were any article that discussed the evidence behind incidence and management of IE including the role of endocarditis team. The exclusion criteria were case reports, expert opinion, and editorials. RESULTS: All the relevant findings are summarized in specified tables and within appropriate sections. DISCUSSION: It is vital to determine the current trends in the epidemiology and microbiology of the condition so that the diagnostic threshold can be adapted, to identify new at-risk groups and achieve an accelerated evaluation strategy that allows for earlier diagnosis and treatment. CONCLUSION: Management of IE can benefit from the input of different specialties, such as cardiology, cardiothoracic surgery, infectious disease, and microbiology. Therefore, adopting a multidisciplinary approach towards treatment is crucial to reduce morbidity and mortality from preventable complications of this pathology.

Bartonella quintana associated neuroretinitis.

We report an observational case of Bartonella quintana-associated neuroretinitis. The patient had a positive IgM IFA titer for Bartonella quintana early in the disease. After treatment, the neuroretinitis and IgM resolved. Given the patient's history, symptoms, response to treatment, and IgM course, we believe his neuroretinitis was secondary to Bartonella quintana.

Aspergillus terreus endophthalmitis.

We report a case of Aspergillus terreus endophthalmitis and review the 4 previously reported cases. Immunosuppression, intravenous drug use, intraocular surgery or trauma, and a compatible clinical picture should raise suspicion of the diagnosis. This species often exhibits resistance to amphotericin B and outcomes are poor despite current therapies.