Exploring Gender Disparities in Factors Influencing Colorectal Cancer Screening Compliance in Singapore.

OBJECTIVE: The uptake of colorectal cancer (CRC) screening remains suboptimal in Singapore. Existing research highlights gender-related disparities in screening behaviors. This study aims to evaluate the gender differences in factors associated with CRC screening compliance in Singapore, with a specific focus on cancer screening beliefs and knowledge on CRC screening guidelines. METHODS: Data were collected from an online survey on cancer screening belief, knowledge, and practices in Singapore. Multivariate logistic regression analysis was conducted to identify independent factors associated with compliance in CRC screening. RESULTS: The study included 633 participants aged 50-69 years, eligible for CRC screening. Only 132 participants (20.9%) complied with CRC screening guidelines with no significant gender differences observed in compliance rates. Most participants held positive beliefs on routine screening (86.9%) and perceived screening benefits in improving treatment outcomes (89.6%) and reducing mortality rates (77.6%). However, both genders exhibited limited knowledge regarding CRC screening guidelines. Only 28.3% were aware that CRC screening should commence at age 50 years. While nearly half of participants knew FIT (44.7%) and colonoscopy (52.0%) as CRC screening modalities, only 27.5% and 15.2% recognized the recommended intervals for FIT and colonoscopy screening respectively. Multivariate analysis revealed a positive association between knowledge on CRC screening guidelines and CRC screening compliance for both genders. Gender-specific variations were observed in the factors associated with CRC screening compliance. Specifically, women with a family history of cancer, believing in routine cancer screening, and prior adherence to breast cancer screening and men within the older cohort (55-69 years) were more likely to comply with CRC screening. CONCLUSION: Low compliance with CRC screening was observed in Singapore. Targeted interventions should address gender-specific factors and highlight CRC screening guidelines as a crucial component of cancer education for entire screening eligible population in order to improve CRC screening compliance.

Detection of African Swine Fever Virus from Wild Boar, Singapore, 2023.

We detected African swine fever virus (ASFV) from a wild boar in Singapore. In <72 hours, we confirmed and reported ASFV p72 genotype II, CD2v serogroup 8, and IGR-II variant by using a combination of real-time PCR and whole-genome sequencing. Continued biosurveillance will be needed to monitor ASFV in Singapore.

Highly Efficient Thermally Activated Delayed Fluorescence from Pyrazine-Fused Carbene Au(I) Emitters.

Metal-based thermally activated delayed fluorescence (TADF) is conceived to inherit the advantages of both phosphorescent metal complexes and purely organic TADF compounds for high-performance electroluminescence. Herein a panel of new TADF Au(I) emitters has been designed and synthesized by using carbazole and pyrazine-fused nitrogen-heterocyclic carbene (NHC) as the donor and acceptor ligands, respectively. Single-crystal X-ray structures show linear molecular shape and coplanar arrangement of the donor and acceptor with small dihedral angles of <6.5°. The coplanar orientation and appropriate separation of the HOMO and LUMO in this type of molecules favour the formation of charge-transfer excited state with appreciable oscillator strength. Together with a minor but essential heavy atom effect of Au ion, the complexes in doped films exhibit highly efficient (Φ∼0.9) and short-lived (<1 µs) green emissions via TADF. Computational studies on this class of emitters have been performed to decipher the key reverse intersystem crossing (RISC) pathway. In addition to a small energy splitting between the lowest singlet and triplet excited states (ΔEST ), the spin-orbit coupling (SOC) effect is found to be larger at a specific torsion angle between the donor and acceptor planes which favours the RISC process the most. This work provides an alternative molecular design to TADF Au(I) carbene emitters for OLED application.

Genome-wide transcriptome profiling and spatial expression analyses identify signals and switches of development in tapeworms.

BACKGROUND: Tapeworms are agents of neglected tropical diseases responsible for significant health problems and economic loss. They also exhibit adaptations to a parasitic lifestyle that confound comparisons of their development with other animals. Identifying the genetic factors regulating their complex ontogeny is essential to understanding unique aspects of their biology and for advancing novel therapeutics. Here we use RNA sequencing to identify up-regulated signalling components, transcription factors and post-transcriptional/translational regulators (genes of interest, GOI) in the transcriptomes of Larvae and different regions of segmented worms in the tapeworm Hymenolepis microstoma and combine this with spatial gene expression analyses of a selection of genes. RESULTS: RNA-seq reads collectively mapped to 90% of the > 12,000 gene models in the H. microstoma v.2 genome assembly, demonstrating that the transcriptome profiles captured a high percentage of predicted genes. Contrasts made between the transcriptomes of Larvae and whole, adult worms, and between the Scolex-Neck, mature strobila and gravid strobila, resulted in 4.5-30% of the genes determined to be differentially expressed. Among these, we identified 190 unique GOI up-regulated in one or more contrasts, including a large range of zinc finger, homeobox and other transcription factors, components of Wnt, Notch, Hedgehog and TGF-ß/BMP signalling, and post-transcriptional regulators (e.g. Boule, Pumilio). Heatmap clusterings based on overall expression and on select groups of genes representing 'signals' and 'switches' showed that expression in the Scolex-Neck region is more similar to that of Larvae than to the mature or gravid regions of the adult worm, which was further reflected in large overlap of up-regulated GOI. CONCLUSIONS: Spatial expression analyses in Larvae and adult worms corroborated inferences made from quantitative RNA-seq data and in most cases indicated consistency with canonical roles of the genes in other animals, including free-living flatworms. Recapitulation of developmental factors up-regulated during larval metamorphosis suggests that strobilar growth involves many of the same underlying gene regulatory networks despite the significant disparity in developmental outcomes. The majority of genes identified were investigated in tapeworms for the first time, setting the stage for advancing our understanding of developmental genetics in an important group of flatworm parasites.

Non-antibiotic quorum sensing inhibitors acting against N-acyl homoserine lactone synthase as druggable target.

N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography-mass spectrometry (LCMS). These AHL-producing E. coli served as tools for screening AHL synthase inhibitors. Based on a campaign of screening synthetic molecules and natural products using our approach, three strongest inhibitors namely are salicylic acid, tannic acid and trans-cinnamaldehyde have been identified. LCMS analysis further confirmed tannic acid and trans-cinnemaldehyde efficiently inhibited AHL production by RhlI. We further demonstrated the application of trans-cinnemaldehyde inhibiting Rhl QS system regulated pyocyanin production in P. aeruginosa up to 42.06%. Molecular docking analysis suggested that trans-cinnemaldehyde binds to the LasI and EsaI with known structures mainly interacting with their substrate binding sites. Our data suggested a new class of QS-inhibiting agents from natural products targeting AHL synthase and provided a potential approach for facilitating the discovery of anti-QS signal synthesis as basis of novel anti-infective approach.

Plant-derived natural products as sources of anti-quorum sensing compounds.

Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

Piper nigrum, Piper betle and Gnetum gnemon--natural food sources with anti-quorum sensing properties.

Various parts of Piper nigrum, Piper betle and Gnetum gnemon are used as food sources by Malaysians. The purpose of this study is to examine the anti-quorum sensing (anti-QS) properties of P. nigrum, P. betle and G. gnemon extracts. The hexane, chloroform and methanol extracts of these plants were assessed in bioassays involving Pseudomonas aeruginosa PA01, Escherichia coli [pSB401], E. coli [pSB1075] and Chromobacterium violaceum CV026. It was found that the extracts of these three plants have anti-QS ability. Interestingly, the hexane, chloroform and methanol extracts from P. betle showed the most potent anti-QS activity as judged by the bioassays. Since there is a variety of plants that serve as food sources in Malaysia that have yet to be tested for anti-QS activity, future work should focus on identification of these plants and isolation of the anti-QS compounds.

Silencing quorum sensing through extracts of Melicope lunu-ankenda.

Quorum sensing regulates bacterial virulence determinants, therefore making it an interesting target to attenuate pathogens. In this work, we screened edible, endemic plants in Malaysia for anti-quorum sensing properties. Extracts from Melicope lunu-ankenda (Gaertn.) T. G. Hartley, a Malay garden salad, inhibited response of Chromobacterium violaceum CV026 to N-hexanoylhomoserine lactone, thus interfering with violacein production; reduced bioluminescence expression of E. coli [pSB401], disrupted pyocyanin synthesis, swarming motility and expression of lecA::lux of Pseudomonas aeruginosa PAO1. Although the chemical nature of the anti-QS compounds from M. lunu-ankenda is currently unknown, this study proves that endemic Malaysian plants could serve as leads in the search for anti-quorum sensing compounds.