Structure of Telomerase with Telomeric DNA.

Telomerase is an RNA-protein complex (RNP) that extends telomeric DNA at the 3' ends of chromosomes using its telomerase reverse transcriptase (TERT) and integral template-containing telomerase RNA (TER). Its activity is a critical determinant of human health, affecting aging, cancer, and stem cell renewal. Lack of atomic models of telomerase, particularly one with DNA bound, has limited our mechanistic understanding of telomeric DNA repeat synthesis. We report the 4.8 Å resolution cryoelectron microscopy structure of active Tetrahymena telomerase bound to telomeric DNA. The catalytic core is an intricately interlocked structure of TERT and TER, including a previously structurally uncharacterized TERT domain that interacts with the TEN domain to physically enclose TER and regulate activity. This complete structure of a telomerase catalytic core and its interactions with telomeric DNA from the template to telomere-interacting p50-TEB complex provides unanticipated insights into telomerase assembly and catalytic cycle and a new paradigm for a reverse transcriptase RNP.

Structure of Tetrahymena telomerase-bound CST with polymerase α-primase.

Telomeres are the physical ends of linear chromosomes. They are composed of short repeating sequences (such as TTGGGG in the G-strand for Tetrahymena thermophila) of double-stranded DNA with a single-strand 3' overhang of the G-strand and, in humans, the six shelterin proteins: TPP1, POT1, TRF1, TRF2, RAP1 and TIN21,2. TPP1 and POT1 associate with the 3' overhang, with POT1 binding the G-strand3 and TPP1 (in complex with TIN24) recruiting telomerase via interaction with telomerase reverse transcriptase5 (TERT). The telomere DNA ends are replicated and maintained by telomerase6, for the G-strand, and subsequently DNA polymerase α-primase7,8 (PolαPrim), for the C-strand9. PolαPrim activity is stimulated by the heterotrimeric complex CTC1-STN1-TEN110-12 (CST), but the structural basis of the recruitment of PolαPrim and CST to telomere ends remains unknown. Here we report cryo-electron microscopy (cryo-EM) structures of Tetrahymena CST in the context of the telomerase holoenzyme, in both the absence and the presence of PolαPrim, and of PolαPrim alone. Tetrahymena Ctc1 binds telomerase subunit p50, a TPP1 orthologue, on a flexible Ctc1 binding motif revealed by cryo-EM and NMR spectroscopy. The PolαPrim polymerase subunit POLA1 binds Ctc1 and Stn1, and its interface with Ctc1 forms an entry port for G-strand DNA to the POLA1 active site. We thus provide a snapshot of four key components that are required for telomeric DNA synthesis in a single active complex-telomerase-core ribonucleoprotein, p50, CST and PolαPrim-that provides insights into the recruitment of CST and PolαPrim and the handoff between G-strand and C-strand synthesis.

Joint host-pathogen genomic analysis identifies hepatitis B virus mutations associated with human NTCP and HLA class I variation.

Evolutionary changes in the hepatitis B virus (HBV) genome could reflect its adaptation to host-induced selective pressure. Leveraging paired human exome and ultra-deep HBV genome-sequencing data from 567 affected individuals with chronic hepatitis B, we comprehensively searched for the signatures of this evolutionary process by conducting "genome-to-genome" association tests between all human genetic variants and viral mutations. We identified significant associations between an East Asian-specific missense variant in the gene encoding the HBV entry receptor NTCP (rs2296651, NTCP S267F) and mutations within the receptor-binding region of HBV preS1. Through in silico modeling and in vitro preS1-NTCP binding assays, we observed that the associated HBV mutations are in proximity to the NTCP variant when bound and together partially increase binding affinity to NTCP S267F. Furthermore, we identified significant associations between HLA-A variation and viral mutations in HLA-A-restricted T cell epitopes. We used in silico binding prediction tools to evaluate the impact of the associated HBV mutations on HLA presentation and observed that mutations that result in weaker binding affinities to their cognate HLA alleles were enriched. Overall, our results suggest the emergence of HBV escape mutations that might alter the interaction between HBV PreS1 and its cellular receptor NTCP during viral entry into hepatocytes and confirm the role of HLA class I restriction in inducing HBV epitope variations.

PHF8 facilitates transcription recovery following DNA double-strand break repair.

Transient halting of transcription activity on the damaged chromatin facilitates DNA double-strand break (DSB) repair. However, the molecular mechanisms that facilitate transcription recovery following DSB repair remain largely undefined. Notably, failure to restore gene expression in a timely manner can compromise transcriptome signatures and may impose deleterious impacts on cell identity and cell fate. Here, we report PHF8 as the major demethylase that reverses transcriptionally repressive epigenetic modification laid down by the DYRK1B-EHMT2 pathway. We found that PHF8 concentrates at laser-induced DNA damage tracks in a DYRK1B-dependent manner and promotes timely resolution of local H3K9me2 to facilitate the resumption of transcription. Moreover, PHF8 also assists in the recovery of ribosomal DNA (rDNA) transcription following the repair of nucleolar DSBs. Taken together, our findings uncover PHF8 as a key mediator that coordinates transcription activities during the recovery phase of DSB responses.

Surface premelting of ice far below the triple point.

Premelting of ice, a quasi-liquid layer (QLL) at the surface below the melting temperature, was first postulated by Michael Faraday 160 y ago. Since then, it has been extensively studied theoretically and experimentally through many techniques. Existing work has been performed predominantly on hexagonal ice, at conditions close to the triple point. Whether the same phenomenon can persist at much lower pressure and temperature, where stacking disordered ice sublimates directly into water vapor, remains unclear. Herein, we report direct observations of surface premelting on ice nanocrystals below the sublimation temperature using transmission electron microscopy (TEM). Similar to what has been reported on hexagonal ice, a QLL is found at the solid-vapor interface. It preferentially decorates certain facets, and its thickness increases as the phase transition temperature is approached. In situ TEM reveals strong diffusion of the QLL, while electron energy loss spectroscopy confirms its amorphous nature. More significantly, the premelting observed in this work is thought to be related to the metastable low-density ultraviscous water, instead of ambient liquid water as in the case of hexagonal ice. This opens a route to understand premelting and grassy liquid state, far away from the normal water triple point.

Inhibition of Cellular Factor TM6SF2 Suppresses Secretion Pathways of Hepatitis B, Hepatitis C, and Hepatitis D Viruses.

Chronic viral hepatitis is caused by hepatitis B virus (HBV), hepatitis C virus (HCV), or hepatitis D virus (HDV). Despite different replication strategies, all of these viruses rely on secretion through the host endoplasmic reticulum-Golgi pathway, providing potential host targets for antiviral therapy. Knockdown of transmembrane 6 superfamily member 2 (TM6SF2) in virus cell culture models reduced secretion of infectious HCV virions, HDV virions, and HBV subviral particles. Moreover, in a cohort of people with hepatitis B, a TM6SF2 polymorphism (rs58542926 CT/TT, which causes protein misfolding and reduced TM6SF2 in the liver) correlated with lower concentrations of subviral particles in blood, complementing our previous work showing decreased HCV viral load in people with this polymorphism. In conclusion, the host protein TM6SF2 plays a key role in secretion of HBV, HCV, and HDV, providing the potential for novel pan-viral agents to treat people with chronic viral hepatitis.

Long-term use of tenofovir disoproxil fumarate increases fracture risk in elderly patients with chronic hepatitis B.

BACKGROUND & AIMS: The use of tenofovir disoproxil fumarate (TDF) is associated with a reduction in bone mineral density and an increase in bone metabolism biomarkers. However, data on clinical bone fractures remain limited. We evaluated the impact of TDF compared to entecavir on the risk of fracture in elderly patients with chronic hepatitis B (CHB). METHODS: Patients with CHB aged ≥60 years receiving entecavir or TDF between January 2008 and December 2022 were identified using a territory-wide database in Hong Kong. The risk of incident fracture in entecavir- and TDF-treated patients before and after month 24 were compared after propensity score matching. RESULTS: A total of 41,531 patients with CHB (mean age 69.8±7.8 years, 61.6% male) receiving entecavir (n = 39,897 [96.1%]) and TDF (n = 1,634 [3.9%]) were analysed. At a median follow-up of 25.3 (9.1-58.5) months, 1,733 (4.2%) patients developed incident fracture. Patients with incident fracture were more likely to have diabetes, hypertension, congestive heart failure, rheumatoid arthritis, osteoporosis, and a history of fracture. Compared with propensity score-matched entecavir-treated patients, the risk of incident fracture in TDF-treated patients was comparable in the first 24 months (weighted subdistribution hazard ratio [sHR] 0.99, 95% CI 0.56-1.73, p = 0.960) but increased after month 24 (weighted sHR 1.80, 95% CI 1.11-2.93, p = 0.019). The 24-, 60-, and 96-month cumulative incidences (95% CI) of fracture in TDF-treated and entecavir-treated patients were 2.3% (1.6%-3.4%) vs. 2.6% (1.9%-3.5%), 6.4% (5.0%-8.2%) vs. 4.7% (3.8%-6.0%), and 10.2% (8.3%-12.6%) vs. 6.8% (5.4%-8.5%), respectively. CONCLUSIONS: The risk of fracture increased with TDF treatment for ≥24 months in elderly patients with CHB. Selection of nucleos(t)ide analogues should be individualised based on age and comorbidities. IMPACT AND IMPLICATIONS: Previous literature suggested that the use of tenofovir disoproxil fumarate (TDF) is associated with a decrease in bone mineral density. However, data on the impact of TDF on long-term incident clinical fracture remains scarce. In this real-world territory-wide study of 41,531 treated patients with chronic hepatitis B in Hong Kong, patients who received TDF were at a higher risk of fracture after 2 years of treatment than those who received entecavir. Given the ageing population of patients with chronic hepatitis B and the rising prevalence of comorbidities, our findings support the current treatment guidelines that recommend selecting antiviral treatment based on age and comorbidities.

A Liver Stiffness-Based Etiology-Independent Machine Learning Algorithm to Predict Hepatocellular Carcinoma.

BACKGROUND & AIMS: The existing hepatocellular carcinoma (HCC) risk scores have modest accuracy, and most are specific to chronic hepatitis B infection. In this study, we developed and validated a liver stiffness-based machine learning algorithm (ML) for prediction and risk stratification of HCC in various chronic liver diseases (CLDs). METHODS: MLs were trained for prediction of HCC in 5155 adult patients with various CLDs in Korea and further tested in 2 prospective cohorts from Hong Kong (HK) (N = 2732) and Europe (N = 2384). Model performance was assessed according to Harrell's C-index and time-dependent receiver operating characteristic (ROC) curve. RESULTS: We developed the SMART-HCC score, a liver stiffness-based ML HCC risk score, with liver stiffness measurement ranked as the most important among 9 clinical features. The Harrell's C-index of the SMART-HCC score in HK and Europe validation cohorts were 0.89 (95% confidence interval, 0.85-0.92) and 0.91 (95% confidence interval, 0.87-0.95), respectively. The area under ROC curves of the SMART-HCC score for HCC in 5 years was ≥0.89 in both validation cohorts. The performance of SMART-HCC score was significantly better than existing HCC risk scores including aMAP score, Toronto HCC risk index, and 7 hepatitis B-related risk scores. Using dual cutoffs of 0.043 and 0.080, the annual HCC incidence was 0.09%-0.11% for low-risk group and 2.54%-4.64% for high-risk group in the HK and Europe validation cohorts. CONCLUSIONS: The SMART-HCC score is a useful machine learning-based tool for clinicians to stratify HCC risk in patients with CLDs.

Limited Sustained Remission After Nucleos(t)ide Analog Withdrawal: Results From a Large, Global, Multiethnic Cohort of Patients With Chronic Hepatitis B (RETRACT-B Study).

INTRODUCTION: Complete viral suppression with nucleos(t)ide analogs (NAs) has led to a profound reduction in hepatocellular carcinoma and mortality among patients with chronic hepatitis B. Finite therapy yields higher rates of functional cure; however, initial hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) elevations are almost certain after treatment interruption. We aimed to analyze off-treatment outcomes beyond 12 months after NA cessation. METHODS: Patients with well-suppressed chronic hepatitis B who were hepatitis B e antigen-negative at NA cessation and remained off treatment without hepatitis B surface antigen (HBsAg) loss at 12 months were included (n = 945). HBV DNA and ALT fluctuations were allowed within the first 12 months. We used Kaplan-Meier methods to analyze outcomes beyond 12 months. Sustained remission was defined as HBV DNA <2,000 IU/mL and ALT <2× upper limit of normal (ULN) and an ALT flare as ALT ≥5× ULN. RESULTS: Cumulative probability of sustained remission was 29.7%, virological relapse was 65.2% with a mean peak HBV DNA of 5.0 ± 1.5 log 10 IU/mL, an ALT flare was 15.6% with a median peak ALT × ULN of 8.3 (5.7-11.3), HBsAg loss was 9.9% and retreatment was 34.9% at 48 months after NA cessation. A single occurrence of virological relapse or an ALT flare within the first 12 months off-treatment were associated with significantly lower rates of sustained remission beyond 12 months. DISCUSSION: Despite allowing for HBV DNA and ALT fluctuations within the first 12 months off-treatment, most patients without HBsAg loss did not maintain a sustained response thereafter. The best candidates for NA withdrawal are patients with low HBsAg levels at NA cessation, and those without profound or recurrent virological and biochemical relapses in the first off-treatment year.

Lycium barbarum glycopeptide promotes neuroprotection in ET-1 mediated retinal ganglion cell degeneration.

BACKGROUND: Vascular dysregulation is one of the major risk factors of glaucoma, and endothelin-1 (ET-1) may have a role in the pathogenesis of vascular-related glaucoma. Fruit extract from Lycium Barbarum (LB) exhibits anti-ageing and multitarget mechanisms in protecting retinal ganglion cells (RGC) in various animal models. To investigate the therapeutic efficacy of LB glycoproteins (LbGP) in ET-1 induced RGC degeneration, LbGP was applied under pre- and posttreatment conditions to an ET-1 mouse model. Retina structural and functional outcomes were characterised using clinical-based techniques. METHODS: Adult C57BL/6 mice were randomly allocated into four experimental groups, namely vehicle control (n = 9), LbGP-Pretreatment (n = 8), LbGP-Posttreatment (day 1) (n = 8) and LbGP-Posttreatment (day 5) (n = 7). Oral administration of LbGP 1 mg/Kg or PBS for vehicle control was given once daily. Pre- and posttreatment (day 1 or 5) were commenced at 1 week before and 1 or 5 days after intravitreal injections, respectively, and were continued until postinjection day 28. Effects of treatment on retinal structure and functions were evaluated using optical coherence tomography (OCT), doppler OCT and electroretinogram measurements at baseline, post-injection days 10 and 28. RGC survival was evaluated by using RBPMS immunostaining on retinal wholemounts. RESULTS: ET-1 injection in vehicle control induced transient reductions in arterial flow and retinal functions, leading to significant RNFL thinning and RGC loss at day 28. Although ET-1 induced a transient loss in blood flow or retinal functions in all LbGP groups, LbGP treatments facilitated better restoration of retinal flow and retinal functions as compared with the vehicle control. Also, all three LbGP treatment groups (i.e. pre- and posttreatments from days 1 or 5) significantly preserved thRNFL thickness and RGC densities. No significant difference in protective effects was observed among the three LbGP treatment groups. CONCLUSION: LbGP demonstrated neuroprotective effects in a mouse model of ET-1 induced RGC degeneration, with treatment applied either as a pretreatment, immediate or delayed posttreatment. LbGP treatment promoted a better restoration of retinal blood flow, and protected the RNFL, RGC density and retinal functions. This study showed the translational potential of LB as complementary treatment for glaucoma management.

Dynamic Changes in ELF Score Predict Hepatocellular Carcinoma in Chronic Hepatitis B Patients Receiving Antiviral Treatment.

Enhanced liver fibrosis (ELF) score is a noninvasive assessment for liver fibrosis. We aimed to evaluate the performance of changes in ELF score 3 years apart in combination with liver stiffness measurement (LSM)-hepatocellular carcinoma (HCC) score to predict HCC in chronic hepatitis B (CHB) patients. This is a prospective cohort study. Patients who underwent transient elastography (TE) examinations and at intermediate or high risk of HCC defined by LSM-HCC score were invited to repeat the examination about 3 years later. Their serum samples at these two time points were retrieved to assess the ELF score changes. The primary endpoint was HCC. There were 445 CHB patients (males: 73.9%; mean age: 51.6 ± 10.3 years) who received two TE examinations and ELF scores. Among them, 252 (56.6%) and 193 (43.4%) patients were at intermediate and high HCC risk at first assessment defined by LSM-HCC score, respectively. Kaplan-Meier analysis showed that the changes in ELF score could stratify the HCC risk in both intermediate- and high-risk patients defined by LSM-HCC score (p < 0.001 for intermediate-risk group; p = 0.011 for high-risk group). Patients remained having mild or moderate fibrosis at both assessments had the lowest risk of HCC (4.0%), followed by patients with fibrosis regressed (11.3%; p = 0.014) during a mean follow-up of 163 months. Patients remained having or progressed to severe fibrosis were at highest risk of HCC (>20%). Consistent findings were demonstrated in patients at both intermediate and high risk of HCC defined by LSM-HCC score. Dynamic changes in ELF score provided additional value to LSM-HCC score for stratifying HCC risk in CHB patients.

Age and the relative importance of liver-related deaths in nonalcoholic fatty liver disease.

BACKGROUND AND AIMS: It is unclear if the leading causes of death in patients with NAFLD differ by age. We aimed to investigate if the relative importance of liver-related deaths is lower and overshadowed by cardiovascular and cancer-related deaths in the elderly population. APPROACH AND RESULTS: We conducted a territory-wide retrospective cohort study of adult patients with NAFLD between 2000 and 2021 in Hong Kong. The outcomes of interest were all-cause and cause-specific mortality. Age groups at death were studied at 10-year intervals. During 662,471 person-years of follow-up of 30,943 patients with NAFLD, there were 2097 deaths. The top three causes of death were pneumonia, extrahepatic cancer, and cardiovascular diseases. Liver disease was the sixth leading cause of death in patients aged 70-79 and 80-89 years, accounting for 5.1% and 5.9% of deaths, respectively, but only accounted for 3% or fewer of the deaths in the other age groups. Nonetheless, liver disease was the leading cause of death in patients with NAFLD-related cirrhosis, accounting for 36.8% of all deaths. The incidence of liver-related death was higher in men younger than age 70 but higher in women afterwards. The incidence of liver-related death in women increased from 0.62 to 7.14 per 10,000 person-years from age 60-69 to 70-79 years. CONCLUSION: The relative importance of liver-related death increases with age in patients with NAFLD, especially among women. In patients with cirrhosis, liver disease is the leading cause of death.

Duration of type 2 diabetes and liver-related events in nonalcoholic fatty liver disease: A landmark analysis.

BACKGROUND AND AIMS: We aimed to determine the impact of the duration of type 2 diabetes (T2D) on the risk of liver-related events and all-cause mortality in patients with NAFLD. APPROACH AND RESULTS: We conducted a territory-wide cohort study of adult patients with NAFLD diagnosed between January 1, 2000, and July 31, 2021, in Hong Kong. T2D was defined by the use of any antidiabetic agents, laboratory tests, and/or diagnosis codes. The primary endpoint was liver-related events, defined as a composite endpoint of HCC and cirrhotic complications. To conduct a more granular assessment of the duration of T2D, we employed landmark analysis in four different ages of interest (biological age of 40, 50, 60, and 70 years). By multivariable analysis with adjustment of non-liver-related deaths, compared with patients without diabetes at age 60 (incidence rate of liver-related events: 0.70 per 1,000 person-years), the adjusted subdistribution HR (SHR) of liver-related events was 2.51 (95% CI: 1.32-4.77; incidence rate: 2.26 per 1,000 person-years) in patients with T2D duration < 5 years, 3.16 (95% CI: 1.59-6.31; incidence rate: 2.54 per 1,000 person-years) in those with T2D duration of 6-10 years, and 6.20 (95% CI: 2.62-14.65; incidence rate: 4.17 per 1000 person-years) in those with T2D duration more than 10 years. A similar association between the duration of T2D and all-cause mortality was also observed. CONCLUSIONS: Longer duration of T2D is significantly associated with a higher risk of liver-related events and all-cause mortality in patients with NAFLD.

A pilot integrated model nurse clinic increases the uptake of antiviral treatment for the prevention of mother-to-child transmission of HBV.

BACKGROUND AND AIMS: Mother-to-child-transmission (MTCT) of hepatitis B virus (HBV) may still occur despite birth-dose HBV vaccinations when pregnant women are positive for hepatitis B surface antigen (HBsAg) with high viral loads (HBV DNA ≥ 200 000 IU/mL). A pilot integrated model nurse clinic (IMNC) was started in 2020 to implement the pre-emptive antiviral therapy with tenofovir disoproxil fumarate (TDF). We aimed to evaluate the performance of IMNC on uptake of TDF. METHODS: This was a territory-wide retrospective cohort of all consecutive HBsAg-positive women of child-bearing age with pregnancy records in public hospitals 2019-2022. Demographic characteristics, liver biochemistries and virologic parameters, and TDF use were collected. Concurrently, data from a prospective audit in Union Hospital, the private hospital with the highest number of deliveries in Hong Kong, from June 2022 to May 2023 were compared. RESULTS: The prevalence rate of HBV DNA ≥ 200 000 IU/mL in pregnant women with available HBV DNA records was 29.2% (66/226) in 2019, 27.3% (99/363) in 2020, 15.9% (125/784) in 2021 and 17.2% (117/679) in 2022 (p < .001), out of 2052 pregnant women who had their HBV DNA checked within 1 year prior to delivery. An increasing uptake rate of TDF by highly viraemic pregnant women (i.e. ≥ 200 000 IU/mL) was noted after the commencement of IMNC in public hospitals, with 67% (45/67) in 2019, 83% (88/106) in 2020, 91% (117/128) in 2021 and 89% (149/167) in 2022. Moreover, all highly viraemic pregnant women from Union Hospital received TDF. Continuous use of TDF was associated with a reduced risk of postpartum biochemical flare. CONCLUSIONS: IMNC increases the uptake of antiviral treatment in pregnant women at risk of MTCT of HBV. IMNC contributes to hepatitis elimination through a structured care plan to prevent MTCT of HBV.

Focal point technology: Controlling treatment depth and pattern of skin injury by a novel highly focused laser.

BACKGROUND: Selective photothermolysis has limitations in efficacy and safety for dermal targets. We describe a novel concept using scanned focused laser microbeams for precise control of dermal depth and pattern of injury, using a 1550 nm laser that generates an array of conical thermal zones while minimizing injury to the epidermis. OBJECTIVE: To characterize the conical thermal zones in vivo and determine safe starting parameters to transition to a second phase to explore potential clinical indications. METHODS: A focused toroidal (ring) laser beam was delivered through a cold sapphire window, sparing epidermal injury in a central zone. Pulse energy, lesion depth, density, and energy delivery were titrated in ex vivo human skin and subsequently on the backs of 21 human subjects. RESULTS: Histology showed microscale patterns of thermal injury, which varied predictably with laser parameters. Time-course healing through histology and skin surface imaging demonstrated the ability of the device to deliver high energies without sequelae. LIMITATIONS: Clinical data are currently being collected to further explore the safety and efficacy of the device. CONCLUSION: The 1550 nm laser with focal point technology enables precise control of lesion depth while simultaneously sparing a large portion of the epidermis, lowering the risk of adverse effects.

Ab Initio-Based Bond Order Potential for Arsenene Polymorphs Developed via Hierarchical Reinforcement Learning.

Arsenene, a less-explored two-dimensional material, holds the potential for applications in wearable electronics, memory devices, and quantum systems. This study introduces a bond-order potential model with Tersoff formalism, the ML-Tersoff, which leverages multireward hierarchical reinforcement learning (RL), trained on an ab initio data set. This data set covers a spectrum of properties for arsenene polymorphs, enhancing our understanding of its mechanical and thermal behaviors without the complexities of traditional models requiring multiple parameter sets. Our RL strategy utilizes decision trees coupled with a hierarchical reward strategy to accelerate convergence in high-dimensional continuous search spaces. Unlike the Stillinger-Weber approach, which demands separate formalisms for buckled and puckered forms, the ML-Tersoff model concurrently captures multiple properties of the two polymorphs by effectively representing the local environment, thereby avoiding the need for different atomic types. We apply the ML model to understand the mechanical and thermal properties of the arsenene polymorphs and nanostructures. We observe an inverse relationship between the critical strain and temperature in arsenene. Thermal conductivity calculations in nanosheets show good agreement with ab initio data, reflecting a decrease in thermal conductivity attributable to increased anharmonic effects at higher temperatures. We also apply the model to predict the thermal behavior of arsenene nanotubes.

Wavelength-dependent threshold fluences for melanosome disruption to evaluate the treatment of pigmented lesions with 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

BACKGROUND AND OBJECTIVES: A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively. STUDY DESIGN/MATERIALS AND METHODS: A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue. RESULTS: The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications. CONCLUSION: The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

Evaluation of a Novel Dermal Cooling System for the Treatment of Benign Pigmented Lesions in Asians.

OBJECTIVE: Our study aimed to evaluate the efficacy of this novel dermal cooling system (DCS) in reducing pigmentation in benign pigmented lesions in Asian patients and its potential side effects. METHODS: It was a prospective open-label single-center study. Asian patients, with the presence of benign pigmented lesions mainly including lentigines, melasma, nevus spilus, ephelides, café au lait, and seborrheic keratosis were recruited for a novel DCS. The DCS provided localized cooling of the epidermal layer below freezing but was less intense than cryotherapy. Each patient received DCS at Week 0 and repeated at 4-week intervals up to 10 sessions. Global aesthetic improvement scores (GAIS) by blinded physicians and subjects were recorded at 2, 6, and 12 months posttreatment follow-up. RESULTS: Eighty-one patients were recruited with a total of 305 sessions performed and 1716 lesion sites treated. At 2-month posttreatment, 76.5% and 58.6% treatment sites showed obvious to marked improvement respectively and the improvement sustained at 6 and 12 months. Only minor adverse events were reported. Erythema and edema were the most commonly anticipated effects immediately after treatment. The pain was minimal. Postinflammatory hyperpigmentation was only reported in 2.2% (38/1716) treated sites. CONCLUSION: To our knowledge, this study was the first study to demonstrate that this novel DCS was an effective, safe, and well-tolerated treatment for benign pigmented lesions in Asians.

The use of fractional radiofrequency in Asian patients to improve skin texture.

BACKGROUND AND OBJECTIVES: Fractional radiofrequency devices have been demonstrated to improve skin texture, such as smoothness, rhytides, brightness, and atrophic acne scars, by increasing dermal thickness, dermal collagen content, and dermal fibrillin content. The objective of the study is to assess the efficacy and adverse effects of this device on Asian patients of skin type III and IV with skin textural changes. MATERIALS AND METHODS: The study was designed as a prospective, open-labeled single-arm study, which was conducted with 20 Chinese patients aged 21-60 years and having irregularities in their skin texture, rhytides, and acne scars. The patients received six treatments at intervals of 4 weeks. Treatment was initiated with the maximum energy tolerated, which was then adjusted during the course of treatment if the patients felt excessive discomfort. A total of two passes were delivered in each session. Physician assessment results and standardized photographs were collected at the baseline, after all treatment visits, and at 1, 2, and 6 months after the final treatment visit. RESULTS: A total of 17 patients completed the study according to the established protocol. At the 6-month follow-up, 71% of patients were satisfied and 24% of patients were very satisfied with the received treatments, and the treatment physician reported varying degrees of improvement based on the global assessment scale in 60% of the subjects. While the anticipated side effects, such as erythema, edema, pinpoint bleeding, scab formation, and flare of acne, were noted in the patients, no serious adverse effects occurred. CONCLUSION: The use of fractional radiofrequency improves skin texture and is safe for use in Asian patients of skin type III and IV. No long-term serious adverse effects were noted.

Randomised phase 2 study (JADE) of the HBV capsid assembly modulator JNJ-56136379 with or without a nucleos(t)ide analogue in patients with chronic hepatitis B infection.

OBJECTIVE: We present the final analysis results of the phase 2 JADE study (ClinicalTrials.gov Identifier: NCT03361956). DESIGN: 232 patients with chronic hepatitis B (CHB) not currently treated at study start (NCT) at study start or virologically suppressed were randomised to receive 75 mg (part 1) or 250 mg (part 2) JNJ-56136379, a hepatitis B virus (HBV)-capsid assembly modulator, one time per day or placebo with nucleos(t)ide analogue (NA) (tenofovir disoproxil fumarate/entecavir) or JNJ-56136379 alone (NCT-only) for ≥24 and ≤48 weeks. RESULTS: In patients who are NCT hepatitis B e-antigen (HBeAg) positive, JNJ-56136379 75 mg+NA and 250 mg+NA showed limited mean (SE) hepatitis B surface antigen (HBsAg) declines (0.14 (0.10) and 0.41 (0.15), respectively) from baseline at Week 24 (primary endpoint; placebo+NA: 0.25 (0.11) log10 international unit (IU)/mL).In patients who are NCT HBeAg positive, mean (SE) HBV DNA declines at Week 24 were 5.53 (0.23) and 5.88 (0.34) for JNJ-56136379 75 mg+NA and 250 mg+NA, respectively, versus 5.21 (0.42) log10 IU/mL for placebo+NA. In NCT patients, mean (SE) HBV RNA declines were 2.96 (0.23) and 3.15 (0.33) versus 1.33 (0.32) log10 copies/mL, respectively.Patients with HBsAg declines had HBeAg and hepatitis B core-related antigen (HBcrAg) declines and some early on-treatment isolated alanine aminotransferase flares. Viral breakthrough occurred with JNJ-56136379 monotherapy with the emerging resistant-variant T33N, but not with JNJ-56136379+NA. JNJ-56136379 treatment beyond Week 24 had a generally small additional effect on viral markers.No study treatment-related serious adverse events or clinically significant changes in laboratory parameters occurred. CONCLUSIONS: In patients with non-cirrhotic CHB, JNJ-56136379+NA showed pronounced reductions in HBV DNA and HBV RNA, limited HBsAg or HBeAg declines in patients who are NCT HBeAg positive, and was well tolerated, but no clear benefit with regards to efficacy of JNJ-56136379 over NA was observed.