16 research outputs found

    Genome-wide Association Study Identifies Genetic Variants Associated With Early and Sustained Response to (Pegylated) Interferon in Chronic Hepatitis B Patients: The GIANT-B Study

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    Background. (Pegylated) Interferon ([Peg]IFN) therapy leads to response in a minority of chronic hepatitis B (CHB) patients. Host genetic determinants of response are therefore in demand. Methods. In this genome-wide association study (GWAS), CHB patients, treated with (Peg)IFN for at least 12 weeks ± nucleos(t)ide analogues within randomized trials or as standard of care, were recruited at 21 centers from Europe, Asia, and North America. Response at 24 weeks after (Peg)IFN treatment was defined as combined hepatitis B e antigen (HBeAg) loss with hepatitis B virus (HBV) DNA <2000 IU/mL, or an HBV DNA <2000 IU/mL for HBeAg-negative patients. Results. Of 1144 patients, 1058 (92%) patients were included in the GWAS analysis. In total, 282 (31%) patients achieved the response and 4% hepatitis B surface antigen (HBsAg) loss. GWAS analysis stratified by HBeAg status, adjusted for age, sex, and the 4 ancestry components identified PRELID2 rs371991 (B= −0.74, standard error [SE] = 0.16, P = 3.44 ×10–6) for HBeAg-positive patients. Importantly, PRELID2 was cross-validated for long-term response in HBeAg-negative patients. G3BP2 rs3821977 (B = 1.13, SE = 0.24, P = 2.46 × 10–6) was associated with response in HBeAg-negative patients. G3BP2 has a role in the interferon pathway and was further examined in peripheral blood mononuclear cells of healthy controls stimulated with IFNα and TLR8. After stimulation, less production of IP-10 and interleukin (IL)-10 proteins and more production of IL-8 were observed with the G3BP2 G-allele. Conclusions. Although no genome-wide significant hits were found, the current GWAS identified genetic variants associated with (Peg)IFN response in CHB. The current findings could pave the way for gene polymorphism-guided clinical counseling, both in the setting of (Peg)IFN and the natural history, and possibly for new immune-modulating therapies

    Retinal stretching limits peripheral visual acuity in myopia

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    AbstractAxial elongation of the myopic eye has the potential to stretch the retina, thereby reducing the sampling density of retinal neurons. Resolution acuity in the peripheral field of normal eyes is known to be sampling-limited, which suggests that retinal stretching in the myopic eye should have a direct effect on resolution acuity everywhere in the visual field except perhaps the fovea, which is usually optically limited. We tested this prediction that neural sampling density is reduced in myopic eyes by measuring resolution acuity for sinusoidal gratings in the fovea plus five peripheral locations in 60 myopic subjects exhibiting a wide range of refractive errors. Control experiments using a detection paradigm to provoke spatial aliasing verified that peripheral resolution was sampling limited. Retinal spatial frequencies of the grating stimulus were computed assuming Knapps’ Law of visual optics, which ensures that retinal image size (in mm) is independent of refractive error when axial myopia is corrected by a spectacle lens located in the anterior focal plane of the eye. Results obtained at every retinal locus showed that resolution acuity declined linearly with magnitude of refractive error. Regression of the population data indicated that approximately 15D of refractive error doubles the spacing between retinal neurons, thereby halving peripheral resolution acuity relative to the emmetropic eye. Several subjects also demonstrated sampling-limited performance in the fovea, which indicated that optical filtering by the eye’s optical system failed to protect the fovea from aliasing artifacts of neural undersampling in these eyes. We conclude that stretching of the retina is a primary cause of reduced spatial resolution of the peripheral field, and occasionally of the fovea, in myopic eyes. Stretching appears to be locally uniform over the central ±15° of visual field but is globally non-uniform since the foveal region appears to stretch more than the globe itself

    Porcine global flash multifocal electroretinogram: Possible mechanisms for the glaucomatous changes in contrast response function

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    Purpose: The aim of this study was to obtain a better understanding of the cellular contributions to the porcine global flash mfERG by using a pharmacologic dissection method, together with the method using variation of stimulus contrast which has been used to demonstrate mfERG changes in human glaucoma.----- Methods: Global flash mfERGs with different stimulus-contrast settings (99%, 65%, 49% or 29%) were recorded from 14 eyes of ten 6-week-old Yorkshire pigs in control conditions and after suppression of inner retinal responses with inhalation of isoflurance (ISO), and injections of tetrodotoxin (TTX) and N-methyl-d-aspartic acid (NMDA). ON- and OFF-pathway responses were isolated by injection of 2-amino-4-phosphonobutyric acid (APB) and cis-2,3-piperidinedicarboylic acid (PDA).----- Results: The porcine global flash mfERG consisted of an early direct component (DC) and a late induced component (IC). ISO and TTX removed inner retinal contributions to the IC; NMDA application further abolished the oscillatory wavelets in the DC and removed the residual IC waveform. The inner retina contributed regular oscillation-like wavelets (W1, W2 and W3) to the DC and shaped the IC. After removing the inner retinal contributions, the porcine global flash mfERG waveform becomes comparable to that obtained with conventional mfERG stimulation. The remaining waveform (smoothed DC) was mainly contributed by the ON- and OFF-bipolar cells as revealed after APB or PDA injection. Photoreceptors contributed a small signal to the leading edge of N1. The characteristic of contrast response function of DC was demonstrated to be contributed by the inner retinal oscillation-like wavelets.----- Conclusion: We believe that the DC of the porcine global flash mfERG is mainly composed of contributions from photoreceptors, and ON- and OFF-bipolar cells, where inner retinal activity partially shaped the DC with superimposed regular wavelets. However, the IC is dominated by inner retinal activity. The contrast response functions of DC consisted of both outer retinal response and oscillation-like wavelets of the inner retinal response. Both contain different characteristics during contrast modulation of the stimulus, where the changes of W2 of the inner retinal response seem independent of contrast modulation. The DC contrast response feature depends mainly on the relative contribution of inner retinal activities; the loss of inner retinal cells may alter the DC contrast response function, making it tend toward linearity

    Energy-based devices for the treatment of acne scars:2022 international consensus recommendations

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    BACKGROUND AND OBJECTIVES: Acne scars are one of the most distressing and long-term consequences of acne vulgaris, with damaging effect on a person\u27s physical, mental, and social well-being. Numerous treatment options are available including surgical and nonsurgical techniques, depending on the clinical presentation. Although considerable advances in the development of new treatment technologies and applications have been made in the last decade, international treatment guidelines and reimbursement schemes have not yet caught up with current knowledge and practice in many centers. The authors intend to highlight the potential utility of energy-based devices (EBDs) for acne scarring, offer recommendations for safe and efficacious treatment, and provide consensus-based EBD treatment options based on varying presentations demonstrated in a series of real-life clinical photographs. STUDY DESIGN/MATERIALS AND METHODS: An international panel of 24 dermatologists and plastic surgeons from 12 different countries and a variety of practice backgrounds was self-assembled to develop updated consensus recommendations for the treatment of acne scars. A two-step modified Delphi method took place between March 2020 and February 2021 consisting of two rounds of emailed questionnaires. The panel members approved the final manuscript via email correspondence. RESULTS: The manuscript includes a comprehensive discussion and panel recommendations regarding the following topics: 1. the role of EBD in mitigating and treating acne scars in a patient with active acne, 2. the use of various EBDs for the treatment of different acne scar types with special focus on commonly used laser platform such as vascular lasers, ablative fractional lasers (AFLs) and non-AFLs (NAFLs), 3. treatment combinations, and 4. acne scar treatments in skin of color. The last part comprised of 10 photos of real-life clinical cases with the panel recommendation treatment plan to achieve best aesthetic outcome. CONCLUSION: Panel members were unanimous in their view that EBDs have a role in the management of acne scars, with AFLs, NAFLs, vascular lasers, and RF devices preferentially selected by most of the panel experts. EBDs are considered a first-line treatment for a variety of acne scar types and patients without access to these treatments may not be receiving the best available care for optimal cosmetic results. Future high-quality research and updated international treatment guidelines and reimbursement schemes should reflect this status
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