Background: Problem based learning (PBL) is both a constructivist pedagogic philosophy and an
instructional format for promoting contextual, co-operative and self-directed learning; it is traditionally
conducted as face-to-face tutorials. This study explored the utility of the live online chat application
Google Hangouts, which we refer to as LOVE-PBL, for running synchronous PBL tutorials that
included participants in different locations. Method: Data were collected from student participants
using a mixed-methods approach, comprising a self-administered questionnaire and focus groups.
We evaluated student participants’ perceptions of their learning experience and the effectiveness
of online PBL via Google Hangouts. Results: More than 70% of participants agreed that learning
outcomes were met using the Google Hangouts platform, and 50% felt that the ability to record the
sessions was useful for learning and reflection. The major factors for effective online PBL were reliable
internet connectivity, a conducive environment, and technical familiarity with the chat application
and its functionality. Conclusion: Although online discussions do not fully equate to face-to-face
conversations with regard to utility and enjoyment, learning outcomes are not compromised. Online
chat applications thus extend the utility of PBL, and their use adds to the accessibility, flexibility and
convenience that learners expect of higher education in a digital age.
Imidazo[1,2-a]pyridine is one of the most potential bicyclic 5-6 heterocyclic rings that is recognized as a "drug prejudice" scaffold due to its broad range of applications in medicinal chemistry such as anticancer, antimycobacterial, antileishmanial, anticonvulsant, antimicrobial, antiviral, antidiabetic, proton pump inhibitor, insecticidal activities. This scaffold has also been represented in various marketed preparations such as zolimidine, zolpidem, alpidem. Therefore, several attempts were made to carry out the structural modifications of this scaffold to discover and develop novel therapeutic agents. This review provides a valuable insight into the research findings of wide range of derivatives of imidazo[1,2-a]pyridine scaffold leading to promising heterocyclic compounds which could be explored further for the synthesis of new derivatives as well as construction of potential drug-like chemical libraries for biological screening in search of new therapeutic agents.
Background: Andrographolide and its benzylidene derivatives, SRJ09 and SRJ23, potentially bind oncogenic K-Ras to exert anticancer activity. Their molecular interactions with K-Ras oncoproteins that lead to effective biological activity are of major interest. Methods & results: In silico docking and molecular dynamics simulation were performed using Glide and Desmond, respectively; while saturation transfer difference NMR was performed using GDP-bound K-RasG12V. SRJ23 was found to bind strongly and selectively to K-RasG12V, by anchoring to a binding pocket (namely p2) principally via hydrogen bond and hydrophobic interactions. The saturation transfer difference NMR analysis revealed the proximity of protons of functional moieties in SRJ23 to K-RasG12V, suggesting positive binding. Conclusion: SRJ23 binds strongly and interacts stably with K-RasG12V to exhibit its inhibitory activity.
Chemoresistance poses a major hurdle to cancer treatments. Andrographolide-derived SRJ09 and SRJ23 were reported to exhibit potent, selective inhibitory activities against colon and prostate cancer cells, respectively. In this study, previously developed resistant colon (HCT-116rst09) and prostate (PC-3rst23) cancer cell lines were used to elucidate the molecular mechanisms contributing to chemoresistance. Cytotoxic effects of SRJ09 and SRJ23 on both parental and resistant cells were investigated. Cell cycle distributions in HCT-116rst09 cells following SRJ09 treatment were analysed using flow cytometry. Whole-genome microarray analysis was performed on both parental and resistant cells to obtain differential gene expression profiles. Microarray data were subjected to protein-protein interaction network, functional enrichment, and pathway analyses. Reverse transcription-polymerase chain reaction (RT-PCR) was used to validate the changes in expression levels of selected genes. Besides morphological changes, HCT-116rst09 cells showed 7.0-fold resistance to SRJ09 while PC-3rst23 cells displayed a 5.5-fold resistance to SRJ23, as compared with their respective parental cells. G0/G1-phase cell cycle arrest was observed in HCT-116rst09 cells upon SRJ09 treatment. Collectively, 77 and 21 genes were found differentially modulated in HCT-116rst09 and PC-3rst23 cells, respectively. Subsequent bioinformatics analysis revealed several genes associated with FGFR4 and PI3K pathways, and cancer stemness, were chemoresistance mediators in HCT-116rst09 cells. RT-PCR confirmed the HMOX1 upregulation and ATG12 downregulation protected the PC-3rst23 cells from SRJ23 cytotoxicity. In conclusion, acquired chemoresistance to SRJ09 and SRJ23 in colon and prostate cancer cells, respectively, could be attributed to the alterations in the expression of genes such as those related to PI3K and autophagy pathways.
The well-known condition of heart failure is a clinical syndrome that results when the myocardium's ability to pump enough blood to meet the body's metabolic needs is impaired. Most of the cardiac activity is maintained by adrenoceptors, are categorized into two main α and β and three distinct subtypes of β receptor: β1-, β2-, and β3-adrenoceptors. The β adrenoreceptor is the main regulatory macro proteins, predominantly available on heart and responsible for down regulatory cardiac signaling. Moreover, the pathological involvement of Angiotensin-converting enzyme 1 (ACE1)/angiotensin II (Ang II)/angiotensin II type 1 (AT1) axis and beneficial ACE2/Ang (1-7)/Mas receptor axis also shows protective role via Gi βγ, during heart failure these receptors get desensitized or internalized due to increase in the activity of G-protein-coupled receptor kinase 2 (GRK2) and GRK5, responsible for phosphorylation of G-protein-mediated down regulatory signaling. Here, we investigate the various clinical and preclinical data that exhibit the molecular mechanism of upset level of GRK change the cardiac activity during failing heart.