Transcriptome profiling of endothelial cells during infections with high and low densities of Candida albicans cells

Systemic infections of Candida albicans, the most prevalent fungal pathogen in humans, are on the rise in recent years. However, the exact mode of pathogenesis of this fungus is still not well elucidated. Previous studies using C. albicans mutants locked into the yeast form via gene deletion found that this form was avirulent and did not induce significant differential expression of host genes in vitro. In this study, a high density of C. albicans was used to infect human umbilical vein endothelial cells (HUVEC), resulting in yeast-form infections, whilst a low density of C. albicans resulted in hyphae infections. Transcriptional profiling of HUVEC response to these infections showed that high densities of C. albicans induced a stronger, broader transcriptional response from HUVEC than low densities of C. albicans infection. Many of the genes that were significantly differentially expressed were involved in apoptosis and cell death. In addition, conditioned media from the high-density infections caused a significant reduction in HUVEC viability, suggesting that certain molecules released during C. albicans and HUVEC interactions were capable of causing cell death. This study has shown that C. albicans yeast-forms, at high densities, cannot be dismissed as avirulent, but instead could possibly contribute to C. albicans pathogenesis

Transcriptome profile of the human endothelial cell response to high- and low-density infections of Candida albicans

Background: Candida albicans morphology switching and quorum-sensing are important factors for pathogenicity and virulence in persons with a compromised or deficient immune system. This study investigates the in vitro response of human umbilical vein endothelial cells (HUVECs) to infections with low and high densities of C. albicans. We hypothesize that higher cell densities of C. albicans yeast-form cells (blastospores), are more detrimental to HUVECs than lower cell densities of hyphal forms. Methods: Three biological replicates of confluent HUVECs in 6-well plates were challenged with 106 C. albicans blastospores (low-density infection) and 5 x 107 blastospores (highdensity infection) for 8 hours. The low-density infection generated true hyphae, but in the high-density infection, C. albicans remained as blastospores. RNA from these samples were subjected to DNA microarray transcript profiling. For MTT and XTT cell proliferation assays, conditioned media from the co-cultures for microarray experiments were incubated with HUVECs in 96-well plates for 24 hours. Results: The high-density blastospore-HUVEC co-cultures elicited significantly higher differential expression of genes involved in functional pathways of apoptosis, immune response, cell-cell signaling and cancer development, such as ZC3HAV1, HES1, CSF2, CXCL2 and PIM1, compared to the low-density true hyphae-HUVEC co-cultures. Cell proliferation assays also show that HUVECs incubated with conditioned media from the highdensity infection caused a higher percentage of cell death compared to incubation with conditioned media from the low-density infection. These results suggest that high densities of unattenuated, innate C. albicans blastospore cells can cause significant cellular toxicity, even though the cells are in the yeast form, not filamentous. Conclusion: Transcript profiling of this in vitro endothelial cell model may provide new insights into how C. albicans cell densities affect the host during the colonization and invasion through the bloodstream to the deep organs. We also suggest that quorum-sensing molecules and other unknown secretions from high-density C. albicans infections are strong inducers of cellular injury leading to cell death in systemic candidiasis

Structural Characterization and Visible Light-Induced Photoelectrochemical Performance of Fe-Sensitized TiO2 Nanotube Arrays Prepared via Electrodeposition

Surface modification of TiO2 nanotube arrays via metal doping is one of the approaches to narrow the wide bandgap of TiO2 in order to increase its adsorption to the visible region. The present work focuses on the fabrication of a Fe-sensitized TiO2 nanotube arrays (Fe- TNT) photoanode. Ordered Fe-TNTs were successfully synthesized using a facile two-step electrochemical method by varying the deposition voltage (2-4 V). The morphology, structure, composition, and visible light response were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), UV-Vis diffusion reflection spectroscopy (DRS), and photoelectrochemical (PEC) test. The XRD investigation demonstrated that the sensitization of Fe did not destroy the nanotube array structure, and the Fe-TNTs had an anatase phase composed of cubic-like particles at higher deposition voltages. The UV–Vis absorption spectra of the Fe-TNTs showed a redshift of photoresponse towards visible light. Such a redshift was characterized by a decrease in bandgap energy and the photo efficiency was enhanced. The optimal photoelectrochemical performance was observed at 2.5 V deposition voltage for 10 minutes and surpassed that of pristine titania nanotube arrays. The present work demonstrates feasible modification of TiO2 with Fe as a potential photoanode in solar conversion devices

Inhibition of hyphae formation and SIR2 expression in Candida albicans treated with fresh Allium sativum (garlic) extract

Aims: The aims of the present study were to determine whether Allium sativum (garlic) extract has any effect on the morphology transformation of Candida albicans, and to investigate whether it could alter the gene expression level of SIR2, a morphogenetic control gene and SAP4, a gene encoding secreted aspartyl proteinase. Methods and Results: Candida albicans cells were incubated with a range of concentrations of fresh garlic extract, and the morphology was monitored via light microscopy. Garlic extract treatment caused the transition of yeast form to hyphal form to be obviated. The expression of SIR2 was down-regulated from 1.2- to 2.5-fold with increasing concentration of the garlic extract, as determined from relative quantitative reverse transcription- polymerase chain reaction. There was no difference in the SAP4 expression in control vs treated cultures. Conclusions: Garlic and its bioactive components have the ability to suppress hyphae production and to affect the expression level of SIR2 gene. Significance and Impact of the Study: Hyphal production is an essential virulence determinant of C. albicans for invasive infections, therefore garlic and its constituents can be effective not only against colonizing C. albicans strains present in mucosal infections, but also virulent strains causing systemic or invasive candidiasis

An alternative Candida spp. cell wall disruption method using a basic sorbitol lysis buffer and glass beads

This report describes a modified, cost-effective method of cell wall disruption for the yeast Candida spp., which employs the use of glass beads in a simple sorbitol lysis buffer. This method can be used in conjunction with a commercial RNA or genomic DNA isolation method to obtain high-quality RNA or DNA

Recent progress of Ag/TiO2 photocatalyst for wastewater treatment: Doping, co-doping, and green materials functionalization

Surface modification via doping or functionalization is one of the most commonly applied approaches for addressing the innate limitations of TiO2 photocatalysts. Amongst numerous dopants, silver (Ag) has been regarded as an efficient strategy to retard electron holes recombination due to the formation of the Schottky barrier on the TiO2 interface and extending absorption to the visible region. This review primarily focuses on discussing and evaluating the recent progress in the modification of Ag/TiO2 via co-doping with non-metals and transition metals, as well as the synthesis strategies that have been applied in engineering the materials. The effects of doping and co-doping on the induced chemical and physical properties, photocatalytic performance, stability, and recyclability aspects have also been highlighted. This review also examines the potential improvement of Ag/TiO2 through the addition of green materials such as plant-based materials (cellulose-derived composites, chitosan, alginate), ceramic materials (clay, kaolin bentonite), and also ionic liquid green solvent. Recommendations for further research opportunities, limitations, and challenges have also been suggested

Recent progress of Ag/TiO2 photocatalyst for wastewater treatment: Doping, co-doping, and green materials functionalization

Surface modification via doping or functionalization is one of the most commonly applied approaches for addressing the innate limitations of TiO2 photocatalysts. Amongst numerous dopants, silver (Ag) has been regarded as an efficient strategy to retard electron holes recombination due to the formation of the Schottky barrier on the TiO2 interface and extending absorption to the visible region. This review primarily focuses on discussing and evaluating the recent progress in the modification of Ag/TiO2 via co-doping with non-metals and transition metals, as well as the synthesis strategies that have been applied in engineering the materials. The effects of doping and co-doping on the induced chemical and physical properties, photocatalytic performance, stability, and recyclability aspects have also been highlighted. This review also examines the potential improvement of Ag/TiO2 through the addition of green materials such as plant-based materials (cellulose-derived composites, chitosan, alginate), ceramic materials (clay, kaolin bentonite), and also ionic liquid green solvent. Recommendations for further research opportunities, limitations, and challenges have also been suggested

Modified Spent Tea Leaves as Bioadsorbent for Methyl Orange Dye Removal

In this work, the removal of Methyl Orange (MO) from aqueous solution was studied using a new nonconventional and eco-friendly adsorbent, spent tea leaves (STL). Untreated and acid treated STL were used as bio-adsorbent for removal of MO using batch method. Effects of different STL dosages (1 – 4 g), pH solutions (2–11) and initial dye concentrations (10 – 60 mg/L) were investigated. Adsorption experiments conducted using acid treated STL resulted in higher MO removal efficiency ranging from 79 to 92% for 1-4 g of adsorbent dosage compared to the untreated ones which resulted in only 18 to 56% of removal for the similar amount of dosage. In addition, acidic condition favours the MO removal as compared to alkaline medium. Experimental data were analysed using the Langmuir and Freundlich models of adsorption and it was found that adsorption isotherm was best described by Freundlich model and pseudo-first order equation with high correlation coefficient. Results revealed that acid treated STL, being a waste, has the greater potential to be used as adsorbent for MO removal from aqueous solution Lim Ying Pei1, Amira Nadzirah Suhaidi1, Siti Marziya Zulkifli1, Syamil Hidayat Hassim1, Devagi Kanakaraju3 and Lim Ying Chin2

Deep learning based synthetic CT from cone beam CT generation for abdominal paediatric radiotherapy

Objective: Adaptive radiotherapy workflows require images with the quality of computed tomography (CT) for re-calculation and re-optimisation of radiation doses. In this work we aim to improve quality of cone beam CT (CBCT) images for dose calculation using deep learning. / Approach: We propose a novel framework for CBCT-to-CT synthesis using cycle-consistent Generative 10 Adversarial Networks (cycleGANs). The framework was tailored for paediatric abdominal patients, a challenging application due to the inter-fractional variability in bowel filling and smaller patient numbers. We introduced the concept of global residuals only learning to the networks and modified the cycleGAN loss function to explicitly promote structural consistency between source and synthetic images. Finally, to compensate for the anatomical variability and address the difficulties in collecting large datasets in the 15 paediatric population, we applied a smart 2D slice selection based on the common field-of-view across the dataset (abdomen). This acted as a weakly paired data approach that allowed us to take advantage of scans from patients treated for a variety of malignancies (thoracic-abdominal-pelvic) for training purposes. We first optimised the proposed framework and benchmarked its performance on a development dataset. Later, a comprehensive quantitative evaluation was performed on an unseen 20 dataset, which included calculating global image similarity metrics, segmentation-based measures and proton therapy-specific metrics. / Main results: We found improved performance, compared to a baseline implementation, on imagesimilarity metrics such as Mean Absolute Error calculated for a matched virtual CT (55.0±16.6 proposed vs 58.9±16.8 baseline). There was also a higher level of structural agreement for gastrointestinal gas 25 between source and synthetic images measured through dice similarity overlap (0.872±0.053 proposed vs 0.846±0.052 baseline). Differences found in water-equivalent thickness metrics were also smaller for our method (3.3±2.4% proposed vs 3.7±2.8% baseline). / Significance: Our findings indicate that our innovations to the cycleGAN framework improved the quality and structure consistency of the synthetic CTs generated

Perceptions of Quality of Life among Diabetic Patients attending Mosque Road Polyclinic, Kuching

Diabetes is a chronic disease that affects the patient’s quality of life. This crosssectional study aims to determine the socio-demographic characteristics and health profile of diabetic patients, and the relationship between these factors with quality of life. Data was collected using the Short Form - 36 (SF - 36) questionnaire on diabetic patients at the Mosque Road Polyclinic in Kuching. Data was analyzed using SPSS software. The most significant findings were at the Physical Functioning level of the patients. Those who were < 50 years (p=0.004) and 50-59 years (p=0.010) had better score than ≥70 years; Chinese had higher score than Malays (p=0.001); those who had university level education scored higher than secondary level (p=0.024); private sector workers (p=0.001) and government sector workers (p=0.009) had better score than pensioner; and respondents with co morbid condition scored lower than respondents without co morbid condition (p=0.023). Besides that, respondents with no formal education had significant lower mean score in Vitality (p=0.018) and Emotional Health (p=0.022) than those with university qualification. Respondents with uncontrolled diabetes also had significant lower mean score in Role-Emotional (p=0.004) comparing to respondents with controlled diabetes. Diabetes was proven to give a negative impact on the respondent’s quality of life. Thus, early diagnosis of the disease and aggressive management of glucose level must be emphasized to prevent deterioration of quality of life due to the disease complications