Adapting undergraduate paediatric medical education to the challenges of COVID-19 pandemic: perspective of NUS Medicine

COVID-19 significantly impacted the teaching-learning-assessment activities in many medical schools. In this article, we discuss the impact of COVID-19 on the Yong Loo Lin School of Medicine, National University of Singapore, focusing on paediatric training and the adaptations of the system and the people. The school developed strategies to promptly disseminate information and safety measures to protect all its staff and students. By leveraging on the school’s infrastructure for technology-enabled learning, good-quality medical training and reliable assessments were able to be carried out swiftly. The paediatric curriculum was crafted based on these principles, and it provided distance-based learning with live and interactive sessions to teach core clinical skills. The faculty also tapped on standardised patients to provide consistent and life-like scenarios. Measures were implemented to minimise challenges with technology-enabled learning. Collectively, efforts from the staff, support from the leadership and students’ adaptations tremendously helped to ease the transition.

Management of Severe Atopic Dermatitis in Pediatric Patients

Atopic dermatitis is a common, chronic inflammatory skin disorder, present in about 12% of children worldwide. Optimizing management of severe atopic dermatitis in pediatric patients is critical to reduce signs of inflammation, alleviate pruritus and sleep disturbance, minimize the development and/or impact of comorbidities, and improve the patient and caregiver's quality of life. Evaluating the longitudinal severity of pediatric atopic dermatitis is an important component of measuring therapeutic response and long-term management, and is different in clinical practice versus clinical trials. This article describes when and how to use different treatments for pediatric patients with severe atopic dermatitis, including topical medications, phototherapy, and systemic medical therapies (traditional immunosuppressants, biologics, and small molecule inhibitors). It also provides recommendations useful in clinical practice for nonpharmacologic interventions for pediatric patients with severe atopic dermatitis.

Orienting and shaping organic semiconductor single crystals through selective nanoconfinement

For organic semiconductor crystals exhibiting anisotropic charge transport along different crystallographic directions, nanoconfinement is a powerful strategy to control crystal orientation by aligning the fast crystallographic growth direction(s) with the unconfined axis(es) of nanoconfining scaffolds. Here, design rules are presented to relate crystal morphology, scaffold geometry, and orientation control in solution-processed small-molecule crystals. Specifically, organic semiconductor triisopropylsilylethynyl pyranthrene needle-like crystals with a dimensionality of n = 1 and perylene platelike crystals with n = 2 were grown from solution within nanoconfining scaffolds comprising cylindrical nanopores with a dimensionality of m = 1, representing one unconfined dimension along the cylinder axis, and those comprising nanopillar arrays with a dimensionality of m = 2. For m = n systems, native crystal growth habits were preserved while the crystal orientation in n = m direction(s) was dictated by the geometry of the scaffold. For n≠m systems, on the other hand, orientation control was restricted within a single plane, either parallel or perpendicular to the substrate surface. Intriguingly, control over crystal shape was also observed for perylene crystals grown in cylindrical nanopores (n > m). Within the nanopores, crystal growth was restricted along a single direction to form a needle-like morphology. Once growth proceeded above the scaffold surface, the crystals adopted their native growth habit to form asymmetric T-shaped single crystals with concave corners. These findings suggest that nanoporous scaffolds with spatially-varying dimensionalities can be used to grow single crystals of complex shapes.

Adherence of nurses to annual seasonal influenza vaccination over a 5-year period

BACKGROUND

Healthcare workers (HCWs) are at risk of influenza infection with associated nosocomial transmission. Sustained adherence to seasonal influenza vaccination uptake each year is important in epidemic control.

AIM

To assess the adherence of nurses to seasonal influenza vaccination over 5 years and its associated factors.

METHODS

A cross-sectional study was conducted among nurses after the winter influenza season in Hong Kong in March 2019. Based on influenza vaccine uptake rates in the 2014/15-2018/19 seasons, respondents were stratified into three groups: 'full adherence' (vaccine uptake in five seasons), 'partial adherence' (vaccine uptake in one to four seasons) and 'non-adherence' (no vaccine uptake). Stepwise multi-variable logistic regression was performed to determine the associations between adherence to annual influenza vaccination, respondents' characteristics and considerations for vaccination.

FINDINGS

Of 1306 nurses recruited, the majority were female (88%) with a median age of 36 years (interquartile range 30-46 years). The influenza vaccination uptake rate increased from 36% in the 2014/15 season to 47% in the 2018/19 season. After stratification, 39%, 40% and 21% of respondents were non-adherers, partial adherers and full adherers, respectively. Full adherence was significantly associated with female gender [adjusted odds ratio (aOR) 0.60], age ≥40 years (aOR 2.92), long-term care facility nurse (aOR 0.56), uptake during studentship (aOR 3.83), local prevalence of seasonal influenza (aOR 0.51) and expert opinion (aOR 4.04).

CONCLUSIONS

A limited proportion of nurses were fully adherent to seasonal influenza vaccination. Monitoring adherence, improving access to vaccines, and interventions targeting less-adherent HCWs are crucial.

Dynamics of the sub-ambient gelation and shearing of solutions of P3HT and P3HT blends towards active layer formation in bulk heterojunction organic solar cells

Organic solar cells (OSCs) containing an active layer consisting of a nanostructured blend of a conjugated polymer like poly(3-hexylthiophene) (P3HT) and an electron acceptor have the potential of competing against silicon-based photovoltaic panels. However, this potential is largely unfulfilled first due to interrelated production and stability issues of organic solar cells and second due to the unscalable nature of the generally employed spin coating process used for the fabrication of organic solar cells. Furthermore, alternatives to spin coating, especially relying on continuous polymer processing methods like extrusion and coating, cannot be readily applied due to the typically low shear viscosity and elasticity of polymer solutions making up the active layer. Recently, He et al. have reported that the gelation of P3HT with [6,6]-phenyl-C61-butyric acid methyl ester (PC60BM) under sub-ambient conditions can provide a new route to the processing of the active layers of bulk heterojunction solar cells. Furthermore, increases in power conversion efficiencies (PCEs) of the P3HT/PC60BM active layer were determined to be possible under certain shearing and thermal histories of the P3HT/PC60BM gels. Here oscillatory and steady torsional flows were used to investigate the gel formation dynamics of P3HT with a recently proposed non-fullerene acceptor o-IDTBR under sub-ambient conditions and compared with the gelation behavior of P3HT/PC60BM blends. The rheological material functions as well as the gel strengths defined on the basis of linear viscoelastic material functions, characterized via small-amplitude oscillatory shearing, were observed to be functions of the P3HT and o-IDTBR concentrations, the solvent used and the shearing conditions. Overall, the P3HT gels which formed upon quenching to sub-zero temperatures were found to be stable during small-amplitude oscillatory shear (linear viscoelastic range) but broke down even at the relatively low shear rates associated with steady torsional flows, suggesting that the shearing conditions used during the processing of gels of P3HT and blends of P3HT with small molecule acceptors can alter the gel structure, possibly leading to changes in the resulting active layer performance.

On the detection of surface spin freezing in iron oxide nanoparticles and its long-term evolution under ambient oxidation

Exchange bias (EB) effects linked to surface spin freezing (SSF) are commonly found in iron oxide nanoparticles, while signatures of SSF in low-field temperature-dependent magnetization curves have been much less frequently reported. Here, we present magnetic properties of dense assemblies of similar-sized (∼8 nm diameter) particles synthesized by a magnetite (sample S1) and a maghemite (sample S2) method, and the influence of long-term (4 year) sample aging under ambient conditions on these properties. The size of the EB field of the different sample (fresh or aged) states is found to correlate with (a) whether a low-temperature hump feature signaling the SSF transition is detected in out-of-phase ac susceptibility or zero-field-cooled (ZFC) dc magnetization recorded at low field and with (b) the prominence of irreversibility between FC and ZFC curves recorded at high field. Sample S1 displays a lower magnetization than S2, and it is in S1 where the largest SSF effects are found. These effects are significantly weakened by aging but remain larger than the SSF effects in S2, where the influence of aging is considerably smaller. A non-saturating component due to spin disorder in S1 also weakens with aging, accompanied by, we infer, an increase in the superspin and the radius of the ordered nanoparticle cores. X-ray diffraction and Mössbauer spectroscopy provide indication of maghemite-like stoichiometry in both aged samples as well as thicker disordered particle shells in aged-S1 relative to aged-S2 (crystallographically-disordered and spin-disordered according to diffraction and Mössbauer, respectively). The pronounced diminution in SSF effects with aging in S1 is attributed to a (long-term) transition, caused by ambient oxidation, from magnetite-like to maghemite-like stoichiometry, and a concomitant softening of the spin-disordered shell anisotropy. We assess the impact of this anisotropy on the nature of the blocking of the nanoparticle superspins.

Lithium and Chlorine-Rich Preparation of Mechanochemically Activated Antiperovskite Composites for Solid-State Batteries

Assembling all-solid-state batteries presents a unique challenge due to chemical and electrochemical complexities of interfaces between a solid electrolyte and electrodes. While the interface stability is dictated by thermodynamics, making use of passivation materials often delays interfacial degradation and extends the cycle life of all-solid cells. In this work, we investigated antiperovskite lithium oxychloride, Li₃OCl, as a promising passivation material that can engineer the properties of solid electrolyte-Li metal interfaces. Our experiment to obtain stoichiometric Li₃OCl focuses on how the starting ratios of lithium and chlorine and mechanochemical activation affect the phase stability. For substantial LiCl excess conditions, the antiperovskite phase was found to form by simple melt-quenching and subsequent high-energy ball-milling. Li₃OCl prepared with 100% excess LiCl exhibits ionic conductivity of 3.2 × 10⁻⁵ S cm⁻¹ at room temperature, as well as cathodic stability against Li metal upon the extended number of cycling. With a conductivity comparable to other passivation layers, and stable interface properties, our Li₃OCl/LiCl composite has the potential to stably passivate the solid-solid interfaces in all-solid-state batteries.

A review of reported cases of HIV pre-exposure prophylaxis failure with resultant breakthrough HIV infections

OBJECTIVES

Early randomized controlled trials (RCTs) have confirmed high efficacy of pre-exposure prophylaxis (PrEP) for preventing HIV infection in men who have sex with men (MSM) with high HIV exposure risk. Nevertheless, some PrEP failure cases have been reported despite adequate drug adherence. This review aims to summarize the common features of PrEP failure cases and discuss the implications of upscaling PrEP programmes.

METHODS

A search based on articles and clinical trials was conducted through Medline and OVID, with keywords for accessing publications reporting 'true' PrEP failure in the presence of documented adherence to daily regimen of co-formulated tenofovir disoproxil fumarate/emtricitabone.

RESULTS

Ten cases of 'true' PrEP failure were identified, all of which were preceded by continued practice of condomless anal sex, despite documented adherence. Dried blood spot and/or hair analyses provided supporting evidence of adherence in eight cases. There was strong association of PrEP failure with recurrent or multiple sexually transmitted diseases and infection with resistant HIV viruses. Seroconversion was usually atypical or delayed because of significantly suppressed viral load, making diagnosis a clinical challenge.

DISCUSSION

Although it is uncommon, 'true' PrEP failure can occur in a real-world situation, contrary to the outcome of early RCTs. Failure to identify HIV infection while on PrEP can potentially lead to the emergence of drug-resistant virus. To achieve effective HIV prevention, PrEP programmes should emphasize safer sexual practice in addition to drug adherence. Early identification of PrEP failure is crucial, which requires the development of highly sensitive assays and their clinical application.

Role of oxidative stress in clofazimine-induced cardiac dysfunction in a zebrafish model

BACKGROUND

Clofazimine (CFZ), a riminophenazine, is now commonly used in the treatment of multidrug-resistant tuberculosis. However, its use may be potentially associated with cardiac dysfunction in some individuals. In this study, the zebrafish heart, by merit of its developmental and genetic characteristics being in homology with that of human, was chosen as an animal model for evaluation of such dysfunction.

METHODS

Morphological and physiological parameters were used to assess cardiac dysfunction. Transcriptome analysis was performed, followed by validation with real-time quantitative PCR, for delineation of the relevant genomics.

RESULTS

Exposure of 2 dpf zebrafish to 4 mg/L CFZ for 2 days, adversely affected cardiac functions including significant decreases in HR, SV, CO, and FS, with observable pathophysiological developments of pericardial effusion and blood accumulation in the heart, in comparison with the control group. In addition, genes which respond to xenobiotic stimulus, related to oxygen transport, glutathione metabolism and extracellular matrix -receptor interactions, were significantly enriched among the differentially up-regulated genes. Antioxidant response element motif was enriched in the 5000 base pair upstream regions of the differentially expressed genes. Co-administration of N-acetylcysteine was shown to protect zebrafish against the development of CFZ-induced cardiac dysfunction.

CONCLUSIONS

This study suggests an important role of oxidative stress as a major pathogenetic mechanism of riminophenazine-induced cardiac dysfunction.

SARS-CoV-2 causing pneumonia-associated respiratory disorder (COVID-19): diagnostic and proposed therapeutic options

SARS-CoV-2 is responsible for the outbreak of severe respiratory illness (COVID-19) in Wuhan City, China and is now spreading rapidly throughout the world. The prompt outbreak of COVID-19 and its quick spread without any controllable measure defines the severity of the situation. In this crisis, a collective pool of knowledge about the advancement of clinical diagnostic and management for COVID-19 is a prerequisite. Here, we summarize all the available updates on the multidisciplinary approaches for the advancement of diagnosis and proposed therapeutic strategies for COVID-19. Moreover, the review discusses different aspects of the COVID-19, including its epidemiology; incubation period; the general clinical features of patients; the clinical features of intensive care unit (ICU) patients; SARS-CoV-2 infection in the presence of co-morbid diseases and the clinical features of pediatric patients infected with the SARS-CoV-2. Advances in various diagnostic approaches, such as the use of real-time polymerase chain reaction (RT-PCR), chest radiography, and computed tomography (CT) imaging; and other modern diagnostic methods, for this infection have been highlighted. However, due to the unavailability of adequate evidence, presently there are no officially approved drugs or vaccines available against SARS-CoV-2. Additionally, we have discussed various therapeutic strategies for COVID-19 under different categories, like the possible treatment plans with drug (antiviral drugs and anti-cytokines) therapy for disease prevention. Lastly, potentials candidates for the vaccines against SARS-CoV-2 infection have been described. Collectively, the review provides an overview of the SARS-CoV-2 infection outbreak along with the recent advancements and strategies for diagnosis and therapy of COVID-19.

Piloting a partially self-financed mode of human immunodeficiency virus pre-exposure prophylaxis delivery for men who have sex with men in Hong Kong

INTRODUCTION

Pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg is a proven strategy for preventing human immunodeficiency virus (HIV) transmission in men who have sex with men (MSM). This study aimed to test the feasibility and acceptability of PrEP delivered at a pilot clinic for MSM in Hong Kong, where PrEP service is currently unavailable.

METHODS

Partially self-financed PrEP was provided to HIV-negative adult MSM with high behavioural risk of HIV transmission after excluding hepatitis B infection and renal insufficiency. Participants received daily TDF/FTC for 30 weeks at 13.3% of the drug cost. Adherence and behaviours were monitored through questionnaires while creatinine and HIV/STI (sexually transmitted infection) incidence were monitored with point-of-care and laboratory tests. Preference for continuing with PrEP was evaluated at the end of the prescription period.

RESULTS

Seventy-one PrEP-naïve MSM were included in the study, of whom 57 (80%) were retained at the end of 28 weeks. Satisfactory adherence and self-limiting adverse events were reported, while none of the participants contracted HIV. Risk compensation was observed, with an STI incidence of 3.17 per 100 person-years. At the end of the prescription period, a majority (89%) indicated interest in continuing with PrEP. Preference for PrEP was associated with age ≥28 years and peer influence (P=0.04), while stigma was a concern. Price was a deterrent to self-financed PrEP, and only half (51%) considered a monthly cost of ≤HK$500 (US$1=HK$7.8) as reasonable.

CONCLUSIONS

A partially self-financed mode of PrEP delivery is feasible with good retention in MSM in Hong Kong.

Plasmonic Au nanorods stabilized within anodic aluminum oxide pore channels against high-temperature treatment

Au nanorods (Au NRs) are promising candidates for sensing applications due to their tunable localized surface plasmon resonance wavelength. At temperatures above 250 °C, however, these structures are morphologically unstable and tend to evaporate. We herein report a novel refractory plasmonic nanocomposite system comprising Au NRs entrapped in anodized aluminum oxide (AAO) scaffolds that are stable up to 800 °C. Au NRs were synthesized in the cylindrical pores of sapphire-supported AAO via in situ electroless deposition on catalytic Au nanoparticles (Au NPs) anchored on the pore walls. The morphological characteristics and surface-enhanced Raman scattering (SERS) functionality of Au NRs before and after heat treatment were evaluated using SEM, XRD and Raman spectroscopy. Compared to unconfined Au NRs that evolved into spherical particles at temperatures below 250 °C and subsequently evaporated from the substrate surface, the morphology of Au NRs in AAO was preserved upon heat treatment at temperatures up to 800 °C. Furthermore, by tuning the AAO scaffolds thickness and pore diameter, the aspect ratio (AR) of the entrapped Au NRs was varied from 2.4 to 7.8. The SERS sensitivity of Au NRs in AAO was found to increase with decreasing AR when the incident light was parallel to the rod longitudinal axis, in close agreement with the calculated fourth power of the local electromagnetic field using the finite-difference time domain method.

Multi-centre study on cultural dimensions and perceived attitudes of nurses towards influenza vaccination uptake

This study explored how cultural values affected Health Belief Model (HBM) components and the influenza vaccine uptake among nurses across three Asian populations using a survey conducted in 2017 (N = 3971). The vaccination coverages were 33.5% (Brunei), 35.6% (Hong Kong) and 69.5% (Singapore). Three HBM components (perceived susceptibility, perceived benefits and cues to action) were positively associated with vaccination. A direct negative link and an indirect positive link via HBM were observed between collectivism and vaccination, whereas a negative indirect link via HBM between power distance and vaccination was observed. Cultural values, notably collectivism, advanced HBM to study nurses' vaccination.

Transition of Dielectrophoresis-Assembled 2D Crystals to Interlocking Structures under a Magnetic Field

Aspherical cubic hematite colloids with cylindrical arms protruding from each face, referred to as "hexapods", were assembled via negative dielectrophoresis and then manipulated using an applied magnetic field. Upon application of an ac electric field, the hexapods aligned in close-packed linear chains parallel to the field direction. The chains then aggregated to the center of the device, with adjacent chains separated by distances approximately equal to twice the arm length. The resulting open packing structure exhibited cmm plane group symmetry due to the obstruction of arms, with a high density of incorporated defects. Subsequent application of a magnetic field to the dielectrophoresis (DEP)-assembled structure was found to anneal the colloidal crystal by reorienting the hexapods to align their intrinsic magnetic dipoles with the magnetic field direction. During reorganization, the colloidal packing density was found to decrease by more than 10% at both the center and edges of the crystal, accompanied by a significant loss of ordering, prior to redensification of the 2D lattice with fewer defects. Reorganization at the edge was 1.5 times faster than at the center, consistent with the need for cooperative colloidal motion to remove defects at the centers of the crystals.

Transcatheter arterial embolization for iatrogenic bleeding after endoscopic ultrasound-guided pancreaticobiliary drainage

PURPOSE

The purpose of this study was to report the incidence of massive bleeding after endoscopic ultrasound-guided transmural pancreaticobiliary drainage (EUS-TPBD) and the clinical outcomes in patients with this condition treated with transcatheter arterial embolization (TAE).

PATIENTS AND METHODS

We performed a 9-year retrospective analysis of 797 EUS-TPBD procedures (excluding gallbladder or pseudocysts) in 729 patients. Among them, twelve (12/729, 1.65%) patients were referred for TAE to manage active bleeding adjacent to the TPBD sites. There were 8 men and 4 women with a mean age of 66.1 years±13.4 (SD) (range: 45-89 years). The clinical and procedure data of these 12 patients were reviewed.

RESULTS

Thirteen TAE procedures in 12 patients were performed. The bleeding sites were the left hepatic artery (n=7), the right hepatic artery (n=3), the left gastric artery (n=1), the left accessory gastric artery (n=1) and gastroduodenal artery (n=1). TAE was performed with gelatin sponge particles (n=1), coil (n=1) and n-butyl-2 cyanoacrylate with/without coils (n=11), with technical and clinical success rates of 100% (13/13) and 85% (11/13), respectively. Re-bleeding following embolization with gelatin sponge particles occurred in one patient. Procedure-related ischemic hepatitis was observed in another patient with pancreatic cancer with portal vein involvement.

CONCLUSION

On the basis of our results, TAE using n-butyl-2 cyanoacrylate seems safe and effective for the treatment of bleeding after EUS-TPBD procedures. When the portal vein is compromised, TAE of the hepatic artery can cause ischemic liver damage.

Remarkable long-term stability of nanoconfined metal-halide perovskite crystals against degradation and polymorph transitions

Metal-halide perovskites are promising candidates to advance optoelectronic devices but are known to suffer from rapid material degradation. Here we demonstrate that nanoconfinement is an effective strategy for the long-term stabilization of metal-halide perovskite MAPbI3 crystals against humidity-induced degradation and temperature-induced polymorph transitions. Two-dimensional X-ray diffraction patterns of MAPbI3 films reveal an unprecedented air-stability of up to 594 days in non-chemically modified, non-passivated MAPbI3 films deposited on substrates imposing complete 2D confinement on the tens of nanometers length scale. Temperature-dependent X-ray diffraction analysis and optical spectroscopy further reveal the suppression of temperature-dependent phase transitions in nanoconfined MAPbI3 crystals. Most notably, the high-temperature cubic phase of MAPbI3, typically stable at temperatures above 327 K, remains present until a temperature of 170 K when the perovskite crystals are nanoconfined within the 100 nm diameter pores of anodized aluminum oxide templates. Photoluminescence mapping confirms that nanoconfined MAPbI3 crystals exhibit spatial uniformity on the tens of microns length scale, suggesting that nanoconfinement is an effective strategy for the formation of high-quality, stable MAPbI3 crystals across large areas.

The S Sign: A New Radiographic Tool to Aid in the Diagnosis of Slipped Capital Femoral Epiphysis

BACKGROUND

Children with slipped capital femoral epiphysis (SCFE) are often seen by an array of medical professionals prior to diagnosis. Patients with mild slips, slips with knee pain, or bilateral slips can occasionally present a diagnostic challenge that increases the risk of a delay in diagnosis and associated complications.

OBJECTIVES

This study introduces a new radiographic parameter, which we refer to as the S-sign, and analyzes its diagnostic utility on a frog-leg lateral radiograph.

METHODS

Twenty observers reviewed the radiographs from 35 patients with SCFE using Klein's line on anteroposterior pelvis radiographs and the S-sign on frog-leg lateral radiographs to diagnose an SCFE. Analysis included diagnostic outcomes and intraobserver and interobserver reliability.

RESULTS

The S-sign was more accurate at identifying an SCFE compared with Klein's line (92.4% vs. 79.2%, respectively). Sensitivity and specificity was greater for the S-sign compared with Klein's line (89.0% and 95.2% vs. 68.3% and 89.0%, respectively). A combination of the S-sign and Klein's line yielded a sensitivity of 96.5% and a specificity of 85.0%. The combination of tests was more diagnostic for an SCFE, compared with using the Klein's line, which was statistically significant (p < 0.001).

CONCLUSIONS

With increased awareness of the S-sign and a usage of the combined test, clinicians can more reliably and accurately diagnose an SCFE. Clinicians are more likely to diagnose an SCFE using the combined test, compared with solely relying on Klein's line, which we found to be statistically significant.

Frequency and risk factors of drug-induced liver injury during treatment of multidrug-resistant tuberculosis

OBJECTIVES

To investigate the risk factors for drug-induced liver injury (DILI) during the treatment of multidrug-resistant tuberculosis (MDR-TB) and to compare the frequency of DILI in patients with and those without chronic liver disease (CLD).

SETTING

This was a retrospective observational cohort study including 299 consecutive patients who started MDR-TB treatment from January 2009 to December 2013.

DESIGN

Of the 299 patients, 35 had alcoholic liver disease (ALD group), 16 had hepatitis B virus infection (HBV group) and 11 had hepatitis C virus infection (HCV group). The remaining 237 patients without CLD were selected as the control group.

RESULTS

DILI occurred in 29 (9.7%) patients. The frequency of DILI was significantly higher in the ALD (17.1%, P = 0.038), HBV (31.3%, P = 0.005) and HCV groups (27.3%, P = 0.037) than in the control group (6.3%). Among all patients taken together, having HBV and HCV infection were independent risk factors for the occurrence of DILI during MDR-TB treatment.

CONCLUSION

DILI during MDR-TB treatment occurred more frequently in patients with CLD due to ALD, HBV and HCV infection than in those without CLD.

Prevalence of hepatitis C infection and its associated factors in healthy adults without identifiable route of transmission

While hepatitis C virus (HCV) infection is long known to be associated with parenteral exposure, the specific route of transmission is not identified in a proportion of infected patients. Taking blood donors as the surrogate of healthy adults in the community in Hong Kong, we identified 91 HCV-infected donors (≤0.02% positive rate) in 2014-2016, of whom 46 were recruited in a mixed-method study to examine their transmission routes. A majority (75%) of the recruited donors were HCV RNA positive, with the predominant subtypes being 1b and 6a. From the results of the structured self-administered questionnaire and in-depth interviews, only 14 (30%) recruited donors could be traced to past history of contaminated blood transfusion (n = 9) or injection drug use (n = 5). Case-control analyses with 3 different control groups were performed to examine factors associated with HCV infection in multivariable analyses. High-risk sexual behaviour, body piercing, intramuscular injection and vaccine inoculation abroad, having lived abroad for >3 months were significantly associated with HCV in donors with otherwise nonidentifiable source of infection. While the specific route of transmission cannot be established for each person, associations with multiple parenteral exposures outside Hong Kong were observed. The World Health Organization has advocated for the global elimination of HCV by 2030. With a high proportion of HCV-infected persons who are unaware of their infections, HCV elimination could be hard to achieve.

Tenofovir disoproxil fumarate significantly decreases serum lipoprotein levels compared with entecavir nucleos(t)ide analogue therapy in chronic hepatitis B carriers

BACKGROUND

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are first-line treatments for chronic hepatitis B (CHB). Studies suggest lipid lowering effect of TDF in human immunodeficiency virus positive (HIV+) individuals, but the effect on lipids and cardiovascular disease (CVD) risk in CHB is unknown.

AIM

To compare TDF vs ETV effects on lipid levels in CHB.

METHODS

In this retrospective cohort study, data on serum lipids and CVD risk factors at baseline and ~1 year on TDF or ETV were collected from CHB carriers. We used propensity score matched models to assess the effect on total cholesterol (TC), LDL-C, HDL and triglycerides (TGL).

RESULTS

In 348 patients, median age was 57 (IQR: 47-65 years), 63% were male, 77% were Asian, 19% were cirrhotic, 25% were HBeAg positive at baseline, and 72% received TDF vs 28% ETV. ETV-treated patients were older (median age: 60 vs 55, P<.01), had similar smoking and hypertension rates, but diabetes and dyslipidemia were more prevalent (19% vs 9%, P=.01; 14% vs 6%, P=.05, respectively). In propensity score matched models for age, gender, usage of lipid lowering agents, dyslipidemia and diabetes, TDF-treated patients were more likely to show a 20% decrease in TC (95% CI: 3%-25%), LDL-C (95% CI: 1%-25%) and HDL-C (CI: 10%-30%) levels compared with those on ETV. No change in TGL was observed in either group.

CONCLUSIONS

A greater decline in TC, LDL-C and HDL was observed in CHB carriers receiving TDF compared with ETV. These data may influence anti-viral choice in CHB carriers at risk for CVD.

Dielectrophoretic assembly of dimpled colloids into open packing structures

Reversible solid-state phase transitions between open- and close-packed structures in two-dimensional colloidal crystals comprising 1.8 μm dimpled spherical colloids were observed using negative dielectrophoresis. These asymmetrically-shaped colloids adopted lattices with cmm plane group symmetry and a packing fraction, ϕ, of 0.68 at low electric field strengths. At high electric field strengths, the close-packed p6m symmetry was observed, with ϕ = 0.90. The transition between open and close-packed structures was found to be reversible, depending on the applied electric field strength and frequency. Finite Fourier transform analysis and COMSOL simulations revealed the existence of repulsive interactions between colloids perpendicular to the electric field lines due to a concentration of the electric field at the edges of the dimpled regions of the colloids. The repulsive interactions resulted in a stretching of the hexagonal lattice perpendicular to the electric field lines, the magnitude of which depended on the electric field strength. By screening the colloids from the electric field in local potential wells, the entropically favored close-packed hexagonal lattice with ϕ = 0.91 was recovered.