Hepatitis B virus DNA methylation and its potential role in chronic hepatitis B.

Hepatitis B virus (HBV) infection led to 66% liver deaths world-wide in year 2015. Thirty-seven per cent of these deaths were the result of chronic hepatitis B (CHB)-associated hepatocellular carcinoma (HCC). Although early diagnosis of HCC improves survival, early detection is rare. Methylation of HBV DNA including covalently closed circular DNA (cccDNA) is more often encountered in HCC cases than those in CHB and cirrhosis. Three typical CpG islands within the HBV genome are the common sites for methylation. The HBV cccDNA methylation affects the viral replication and protein expression in the course of infection and may associate with the disease pathogenesis and HCC development. We review the current findings in HBV DNA methylation that provide insights into its role in HCC diagnosis.

Knowledge of dental enamel defects amongst undergraduate dental students-a cross-sectional survey.

INTRODUCTION/OBJECTIVES: Enamel defects are disturbances in the quantity or quality of enamel, due to disruption or damage to the enamel organ during amelogenesis. The correct diagnosis of enamel defects is critical as diverse management options could be required for different conditions. Difficulties in diagnosis can happen, because these defects may have similar clinical presentations. This study evaluated the diagnostic skills in enamel defects of dental students of a prominent Australasian school. METHODS: A questionnaire consisting of clinical photographs of the affected teeth/dentition in multiple views and four standardised questions for each case of enamel defect were given to Year 4 and Year 5 students. RESULTS: Localised/Chronological Hypoplasia had the lowest percentage of correct diagnosis (20.5%), whilst Enamel White Spot Lesions (EWSLs) had the highest (85%). Localised/Chronological Hypoplasia had the lowest aetiology score (20.5%), and the highest was obtained for EWSLs (85%). In regard to which question to ask to gain insight into the conditions, Enamel Hypomineralisation/MIH had the lowest score for both Year 4 and Year 5 respondents (35.4% and 21.3%). Most respondents agreed more teaching in this topic was needed, with further clinical sessions to observe the enamel defects, workshops/seminars, lectures and student-driven presentations suggested. CONCLUSION: Final-year dental students showed variable knowledge in diagnosis, aetiology and clinical management of enamel defects. Further didactic and clinical teaching should be incorporated in the undergraduate curriculum on this topic .

Application of acid-modified Imperata cylindrica powder for latent fingerprint development.

A novel powdering material that utilizes acid-modified Imperata cylindrica (IC) powder for the development of fingermarks was studied. Experiments were carried out to determine the suitability, adherence quality and sensitivity of the acid-modified IC powder. Fingermarks of different constituents (eccrine, sebaceous and natural fingermarks) on different types of surfaces were used. Acid-modified IC powder was also used to develop fingermarks of different ages as well as aged fingermarks recovered from the water. From the visual inspection, acid-modified IC powder was able to interact with different fingermark constituents and produced distinct ridge details on the examined surfaces. It was also able to develop aged fingermarks and fingermarks that were submerged in water. A statistical comparison was made against the Sirchie® Hi-Fi black powder in terms of the powders' sensitivity and quality of the developed natural fingermarks. The image quality was analyzed using MITRE's Image Quality of Fingerprint (IQF) software. From the experiments, acid-modified IC powder has the potential as a fingermark development powder, although natural fingermarks developed by Sirchie® black powder showed better quality and sensitivity based on the results of the statistical comparison.

Assessing the impact of direct-acting antivirals on hepatitis C complications: a systematic review and meta-analysis.

Direct-acting antivirals (DAA) have become the treatment of choice for hepatitis C. Nevertheless, efficacy of DAA in preventing hepatitis C complications remains uncertain. We evaluated the impact of DAA on hepatocellular carcinoma (HCC) occurrence and recurrence, all-cause mortality, liver decompensation and liver transplantation as compared to non-DAA treated hepatitis C and the association to baseline liver status. A systematic search for articles from March 1993 to March 2022 was conducted using three electronic databases. Randomized, case-control and cohort studies with comparison to non-DAA treatment and reporting at least one outcome were included. Meta-analysis and sub-group meta-analysis based on baseline liver status were performed. Of 1497 articles retrieved, 19 studies were included, comprising of 266,310 patients (56.07% male). DAA reduced HCC occurrence significantly in non-cirrhosis (RR 0.80, 95% CI 0.69-0.92) and cirrhosis (RR 0.39, 95% CI 0.24-0.64) but not in decompensated cirrhosis. DAA treatment lowered HCC recurrence (RR 0.71, 95% CI 0.55-0.92) especially in patients with baseline HCC and waiting for liver transplant. DAA also reduced all-cause mortality (RR 0.43, 95% CI 0.23-0.78) and liver decompensation (RR 0.52, 95% CI 0.33-0.83) significantly. However, DAA did not prevent liver transplantation. The study highlighted the importance of early DAA initiation in hepatitis C treatment for benefits beyond sustained virological response. DAA therapy prevented HCC particularly in non-cirrhosis and compensated cirrhosis groups indicating benefits in preventing further worsening of liver status. Starting DAA early also reduced HCC recurrence, liver decompensation, and all-cause mortality.

Outcomes of Impaction Bone Grafting in the Management of Acetabular Defects with the Use of Uncemented Acetabular Cups: Do Autografts and Irradiated Femoral Head Allografts Integrate?

Introduction: Acetabular impaction bone grafting (AIBG) has been used widely to reconstruct acetabular defects in complex primary and revision cases. The aim of this study was to look at the outcomes AIBG using either frozen irradiated femoral head allografts or autografts with uncemented acetabular cups. Method: We retrospectively reviewed 38 patients who had AIBG and uncemented cup reconstruction of the acetabulum performed between 2008 and 2021 for complex primary and revision surgery. Graft incorporation, radiological loosening and cup migration were evaluated in follow-up X-rays. Result: There were 24 complex primary and 14 revision total hip arthroplasty. Autografts were used in 10 hips with smaller defects, while 28 hips with larger defects required frozen irradiated femoral head allografts. Using Paprosky classification to evaluate acetabular defects; 8 patients were classified as 2A, 12 as 2B, 7 as 2C, 8 as 3A and 3 as 3B. The Kaplan-Meier survival rate for AIBG with uncemented cups in our series is 89.70% in 10 years. Acetabular cup position was anatomically restored in all autograft AIBG cases and in 25 out of 28 in the allograft group. The mean pre-operative Oxford Hip Score (OHS) was 19 (range 10-24) and post-operative OHS was 39 (range 21-48) (p < 0.001). Conclusions: The mid- to long-term results for AIBG and uncemented acetabular cups is good. With newer and more porous uncemented cups especially revision cups, it may serve as an extended indication to achieve solid fixation together with AIBG technique in managing acetabular defects of ≤ 3A.

Boron deficiency mediates plant-insect (Diaphorima citri) interaction by disturbing leaf volatile organic compounds and cell wall functions.

Nutritional enhancement has been reported to effectively relieve infected symptoms of Huanglongbing, one of the most destructive diseases of citrus. However, few studies focused on the role of plant nutrition in citrus plant-vector (Asian citrus psyllid; Diaphorina citri Kuwayama) interactions, which is regarded as an important part to develop an effective management strategy. METHOD: In the present study, a hydroponic culture was carried out to evaluate the effects of boron deficiency on psyllid feeding process to decode the molecular/biochemical basis of host-psyllid interaction. RESULTS: Boron deficiency was observed to play a major role in accelerating the release of volatile organic compounds, especially methyl salicylate, affecting the shikimic acid pathway through an elevated synthesis of shikimic acid, l-phenylalanine, 3-phenylpyruvic acid and salicylic acid. These changes made citrus leaf more attractive to psyllid adults. Meanwhile, boron deficiency evidently decreased the boron concentration of leaf cell wall fractions, thereby, weakened the structural stability by affecting pectin and cellulose formations. A significant decrease of cell wall mechanical strength was observed in boron-deficiency leaf, which could be the critical reasons to reduce piercing and to increase phloem ingestion during psyllid feeding. CONCLUSION: Our study demonstrated that boron deficiency facilitated the feeding behavior of psyllid adults through elevated release of methyl salicylate, coupled with weakened mechanical properties of cell wall.

Human Genetic Variation Influences Enteric Fever Progression.

In the 21st century, enteric fever is still causing a significant number of mortalities, especially in high-risk regions of the world. Genetic studies involving the genome and transcriptome have revealed a broad set of candidate genetic polymorphisms associated with susceptibility to and the severity of enteric fever. This review attempted to explain and discuss the past and the most recent findings on human genetic variants affecting the progression of Salmonella typhoidal species infection, particularly toll-like receptor (TLR) 4, TLR5, interleukin (IL-) 4, natural resistance-associated macrophage protein 1 (NRAMP1), VAC14, PARK2/PACRG, cystic fibrosis transmembrane conductance regulator (CFTR), major-histocompatibility-complex (MHC) class II and class III. These polymorphisms on disease susceptibility or progression in patients could be related to multiple mechanisms in eliminating both intracellular and extracellular Salmonella typhoidal species. Here, we also highlighted the limitations in the studies reported, which led to inconclusive results in association studies. Nevertheless, the knowledge obtained through this review may shed some light on the development of risk prediction tools, novel therapies as well as strategies towards developing a personalised typhoid vaccine.

Contactless Visualization of Latent Fingerprints on Nonporous Curved Surfaces of Circular Cross Section-A Statistical Evaluation on the Materials as Plane Mirror.

A new contactless technique for latent fingerprint visualization on nonporous curved surfaces of circular cross section was introduced by Low et al. (1). The technique utilizes a plane mirror to convey the light rays toward the inspected surfaces for latent fingerprint visualization. This research activity came up as an extension of the previous study which utilized an aluminum plate as the plane mirror to illuminate the inspected surfaces. Dulling spray was used to increase the diffuse component of the reflective aluminum plate. However, the amount of dulling spray will affect the uniformity of the illumination on the inspected curved surfaces. In this study, a study on the new materials for the plane mirror was carried out. Coated aluminum, opal, and ground glass diffusers were selected as the new materials. The performance of the new materials was compared to the aluminum based on the quality of the captured images on various nonporous cylindrical surfaces. A statistical approach known as randomized complete block design was used to design the experiment. The quality of the captured images was obtained using Spectral Image Validation and Verification. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the quality of the images. From the results of the statistical analysis, coated aluminum has the best performance compared to aluminum, opal, and ground glass diffusers.

Prioritization of reproductive toxicants in unconventional oil and gas operations using a multi-country regulatory data-driven hazard assessment.

BACKGROUND: Recent trends have witnessed the global growth of unconventional oil and gas (UOG) production. Epidemiologic studies have suggested associations between proximity to UOG operations with increased adverse birth outcomes and cancer, though specific potential etiologic agents have not yet been identified. To perform effective risk assessment of chemicals used in UOG production, the first step of hazard identification followed by prioritization specifically for reproductive toxicity, carcinogenicity and mutagenicity is crucial in an evidence-based risk assessment approach. To date, there is no single hazard classification list based on the United Nations Globally Harmonized System (GHS), with countries applying the GHS standards to generate their own chemical hazard classification lists. A current challenge for chemical prioritization, particularly for a multi-national industry, is inconsistent hazard classification which may result in misjudgment of the potential public health risks. We present a novel approach for hazard identification followed by prioritization of reproductive toxicants found in UOG operations using publicly available regulatory databases. METHODS: GHS classification for reproductive toxicity of 157 UOG-related chemicals identified as potential reproductive or developmental toxicants in a previous publication was assessed using eleven governmental regulatory agency databases. If there was discordance in classifications across agencies, the most stringent classification was assigned. Chemicals in the category of known or presumed human reproductive toxicants were further evaluated for carcinogenicity and germ cell mutagenicity based on government classifications. A scoring system was utilized to assign numerical values for reproductive health, cancer and germ cell mutation hazard endpoints. Using a Cytoscape analysis, both qualitative and quantitative results were presented visually to readily identify high priority UOG chemicals with evidence of multiple adverse effects. RESULTS: We observed substantial inconsistencies in classification among the 11 databases. By adopting the most stringent classification within and across countries, 43 chemicals were classified as known or presumed human reproductive toxicants (GHS Category 1), while 31 chemicals were classified as suspected human reproductive toxicants (GHS Category 2). The 43 reproductive toxicants were further subjected to analysis for carcinogenic and mutagenic properties. Calculated hazard scores and Cytoscape visualization yielded several high priority chemicals including potassium dichromate, cadmium, benzene and ethylene oxide. CONCLUSIONS: Our findings reveal diverging GHS classification outcomes for UOG chemicals across regulatory agencies. Adoption of the most stringent classification with application of hazard scores provides a useful approach to prioritize reproductive toxicants in UOG and other industries for exposure assessments and selection of safer alternatives.

Contactless Visualization of Latent Fingerprints on Nonporous Curved Surfaces of Circular Cross Section.

Nondestructive techniques for gathering evidence are important in the field of forensics. Due to the geometry of the substrates, nondestructive visualization of fingermarks on curved surfaces remains challenging. A novel contactless technique was developed for visualizing and recording fingermark patterns on nonporous curved surfaces of circular cross section. The technique utilizes a plane mirror to transmit rays from a light source to illuminate the area of interest for fingermark visualization. The fingermark acquisition system consists of a digital single-lens reflex (SLR) camera, a plane mirror, and a white light source. Mathematical equations are used to calculate the mirror size. Experiments were performed on various curved surfaces to determine the feasibility and effectiveness of the technique. Spectral Image Validation and Verification (SIVV) was used to analyze the captured images. The results of this study indicate that the technique described here is able to reveal fingermark patterns on curved surfaces of circular cross section.

Nanofiber-mediated microRNA delivery to enhance differentiation and maturation of oligodendroglial precursor cells.

Remyelination in the central nervous system (CNS) is critical in the treatment of many neural pathological conditions. Unfortunately, the ability to direct and enhance oligodendrocyte (OL) differentiation and maturation remains limited. It is known that microenvironmental signals, such as substrate topography and biochemical signaling, regulate cell fate commitment. Therefore, in this study, we developed a nanofiber-mediated microRNA (miR) delivery method to control oligodendroglial precursor cell (OPC) differentiation through a combination of fiber topography and gene silencing. Using poly(ε-caprolactone) nanofibers, efficient knockdown of OL differentiation inhibitory regulators were achieved by either nanofiber alone (20-40%, p<0.05) or the synergistic integration with miR-219 and miR-338 (up to 60%, p<0.05). As compared to two-dimensional culture, nanofiber topography enhanced OPC differentiation by inducing 2-fold increase in RIP(+) cells (p<0.01) while the presence of miRs further enhanced the result to 3-fold (p<0.001). In addition, nanofiber-mediated delivery of miR-219 and miR-338 promoted OL maturation by increasing the number of MBP(+) cells significantly (p<0.01). Taken together, the results demonstrate the efficacy of nanofibers in providing topographical cues and microRNA reverse transfection to direct OPC differentiation. Such scaffolds may find useful applications in directing oligodendrocyte differentiation and myelination for treatment of CNS pathological conditions that require remyelination.

Nanofiber-mediated release of retinoic acid and brain-derived neurotrophic factor for enhanced neuronal differentiation of neural progenitor cells.

The treatment of an injured central nervous system using stem-cell-based regenerative medicine still faces considerable hurdles that need to be overcome. Chief among which is the lack of efficient strategies to generate functional neurons from stem cells. The sustained delivery of biochemical cues and synergistic topographical signaling from electrospun nanofibrous scaffolds may be a potential strategy to enhance neuronal differentiation of stem cells for therapeutic purposes. In this study, retinoic acid (RA) and brain-derived neurotrophic factor (BDNF) were encapsulated into a copolymer of ε-caprolactone and ethyl ethylene phosphate to form a multifunctional, electrospun nanofibrous scaffold. Sustained release of RA and BDNF was achieved for at least 7 and 14 days, respectively. Despite lower cumulative release of drugs as compared to bolus delivery to plain nanofibers (at least 2× and 50× lower for RA and BDNF, respectively), nanofiber-mediated delivery of RA and/or BDNF resulted in similar capacity for neuronal differentiation of mouse neural progenitor cells (NPCs). In addition, nanofiber topography significantly increased neuronal differentiation (with BDNF, 47.4% Map2(+) cells on 2D vs. 53.4 to 56.5% on nanofibers, p < 0.05) and reduced glial cell differentiation. BDNF was a more potent inducer of neuronal differentiation than RA. RA supplementation alone resulted in minimal effect on NPC differentiation, and dual supplementation of RA and BDNF did not further enhance the neuronal differentiation of NPCs. Collectively, the results suggest that synergistic effects of nanofiber topography and sustained delivery of RA and/or BDNF may contribute towards the design of a multifunctional artificial stem cell niche for NPC neuronal differentiation.

Topographical effects on fiber-mediated microRNA delivery to control oligodendroglial precursor cells development.

Effective remyelination in the central nervous system (CNS) facilitates the reversal of disability in patients with demyelinating diseases such as multiple sclerosis. Unfortunately until now, effective strategies of controlling oligodendrocyte (OL) differentiation and maturation remain limited. It is well known that topographical and biochemical signals play crucial roles in modulating cell fate commitment. Therefore, in this study, we explored the combined effects of scaffold topography and sustained gene silencing on oligodendroglial precursor cell (OPC) development. Specifically, microRNAs (miRs) were incorporated onto electrospun polycaprolactone (PCL) fiber scaffolds with different fiber diameters and orientations. Regardless of fiber diameter and orientation, efficient knockdown of differentiation inhibitory factors were achieved by either topography alone (up to 70%) or fibers integrated with miR-219 and miR-338 (up to 80%, p < 0.05). Small fiber promoted OPC differentiation by inducing more RIP(+) cells (p < 0.05) while large fiber promoted OL maturation by inducing more MBP(+) cells (p < 0.05). Random fiber enhanced more RIP(+) cells than aligned fibers (p < 0.05), regardless of fiber diameter. Upon miR-219/miR-338 incorporation, 2 µm aligned fibers supported the most MBP(+) cells (∼17%). These findings indicated that the coupling of substrate topographic cues with efficient gene silencing by sustained microRNA delivery is a promising way for directing OPC maturation in neural tissue engineering and controlling remyelination in the CNS.

Mussel-Inspired Modification of Nanofibers for REST siRNA Delivery: Understanding the Effects of Gene-Silencing and Substrate Topography on Human Mesenchymal Stem Cell Neuronal Commitment.

In this study, we promote neuronal differentiation of human mesenchymal stem cells (MSCs) through scaffold-mediated sustained release of siRNA targeting RE-1 silencing transcription factor (REST). Poly (ϵ-caprolactone) nanofibers were surface modified with mussel inspired DOPA-melanin (DM) coating for adsorption of REST siRNA. DM modification increased siRNA-loading efficiency and reduced the initial burst release. Fiber alignment and DM modification enhanced REST knockdown efficiencies. Under non-specific differentiation condition, REST silencing and fiber topography enhanced MSC neuronal markers expressions and reduced glial cell commitment. Such scaffolds may find useful applications in enhancing MSCs neuronal differentiation under non-specific conditions such as an in vivo environment.

Oncological outcomes following robotic-assisted radical prostatectomy in a multiracial Asian population.

This study evaluates the oncological outcomes of RARP in a multiracial Asian population from a single institution. All suitable patients from 1st January 2003-30th June 2013 were identified from a prospectively maintained cancer registry. Peri-operative and oncological outcomes were analysed. Significance was defined as p < 0.05. There were n = 725 patients identified with a mean follow-up duration 28 months. The mean operative time, EBL and LOS were 186 min, 215 ml and 3 days, respectively. The pathological stage was pT2 in 68.6% (n = 497/725), pT3 in 31.3% (n = 227/725) and n = 1 patient with pT4 disease. The pathological Gleason scores (GS) were 6 in 27.9% (n = 202/725), GS 7 in 63.6% (n = 461/725) and GS ≥ 8 in 8.0 % (n = 58/725). The node positivity rate was 5.8% (n = 21/360). The positive margin rates were 31.0% (n = 154/497) and 70.9% (n = 161/227) for pT2 and pT3, respectively, and decreasing PSM rates are observed with surgical maturity. The biochemical recurrence rates were 9.7% (n = 48/497) and 34.2% (n = 78/228) for pT2 and pT3/T4, respectively. On multivariate analysis, independent predictors of BCR were pathological T stage and pathological Gleason score. Post-operatively, 78.5% (n = 569/725) of patients had no complications and 17.7% (n = 128/725) had minor (Clavien grade I-II) complications. This series, representing the largest from Southeast Asia, suggests that RARP can be a safe and oncologically feasible treatment for localised prostate cancer in an institution with moderate workload.

Nanofibrous scaffold-mediated REST knockdown to enhance neuronal differentiation of stem cells.

At present, the recovery prospect for patients with chronic neurodegenerative diseases or acute trauma in the central nervous system is sub-optimal. The controlled differentiation of neural stem/progenitor cells (NPCs) to functional neurons is a possible treatment strategy. In contrast to the classical approach of biochemicals supplementation for guided stem cell commitment, this study explores the feasibility of directing neuronal differentiation through synergistic integration of three-dimensional nanofibrous topographical cues and scaffold-mediated knockdown of RE-1 silencing transcription factor (REST) in mouse NPCs. Taking advantage of the strong adhesive property and latent reactivity of mussel-inspired polydopamine (PD) coating, electrospun polycaprolactone (PCL) nanofibers were successfully functionalized with REST siRNAs (denoted as siREST PD-fiber). Sustained REST knockdown in NPCs was achieved for up to five days in vitro and the silencing efficiency was significantly higher than that mediated through siRNA adsorption onto non-PD coated sample controls. The silencing of REST, together with nanofiber topographical effect, significantly enhanced NPC neuronal commitment (57.5% Map2(+) cells in siREST PD-fiber vs. 43.5% in siREST PD-film vs. 50% in PD-fiber controls, p < 0.05) while reducing astrocytic and oligodendrocytic differentiation (10.7% O4(+) cells vs. ∼30% in siREST PD-film, p < 0.01). Taken together, the synergistic effects of scaffold-mediated REST knockdown and topographical cues from PD-modified nanofibers may be a useful strategy for generating functional neurons for therapeutic purposes.

Evaluation of sulfonated graphene sheets as sorbent for micro-solid-phase extraction combined with gas chromatography-mass spectrometry.

This report describes the use of sulfonated graphene sheets as sorbent in micro-solid-phase extraction (µ-SPE), together with gas chromatography-mass spectrometry, for the determination of polycyclic aromatic hydrocarbons (PAHs) in water. In this study, for the first time, graphene sheets were used as a sorbent material for this mode of microextraction. The modified graphene sheets were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, and elemental analysis. µ-SPE parameters such as extraction time, desorption time and desorption solvent were optimized. The method showed good precision, reproducibility and linear response for PAH analysis over a concentration range of 0.05-100 µg/L for naphthalene and 0.01-100 µg/L for the remaining PAHs (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) with coefficient of determination (r(2)) of higher than 0.992. Limits of detection of from 0.8 to 3.9 ng/L for 7 PAHs were achieved. The developed method was successfully applied to determine PAHs in river water samples.