Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Prevalence and determinants of sexual abuse among adolescent girls during the COVID-19 lockdown and school closures in Ghana: A mixed method study

BACKGROUND

In the wake of the COVID-19 pandemic, concerns have been raised that the pandemic may derail global efforts against child sexual abuse (CSA).

OBJECTIVES

This study examines the prevalence and associated factors of sexual abuse among adolescent girls in the context of the COVID-19 pandemic in Ghana.

PARTICIPANTS AND SETTING

The sample comprised 853 adolescent girls aged 13-19 (16.03 ± 2.04 years) in Ghana.

METHODS

The study employed a concurrent mixed-method design.

RESULTS

Overall, the prevalence of CSA during the COVID-19 lockdown and school closures was 32.5 %. Protective factors for CSA were feeling safe in neighbourhood (AOR = 0.526, 95 % CI = [0.325, 0.850]) and parents often listen to opinions (AOR = 0.446, 95 % CI = [0.241, 0.826]). Risk factors for CSA were physical activity (AOR = 1.649, OR = 1.783, 95 % CI_AOR = [1.093, 2.487, 95 % CI_OR = [1.241, 2.561]), parents sometimes listen to opinions (AOR = 1.199, OR = 1.924, 95 % CI_AOR = [0.504, 2.853], 95 % CI_OR = [1.034, 3.582]), living with another relative (AOR = 2.352, OR = 2.484, 95 % CI_AOR = [0.270, 20.523], 95 % CI_OR = [0.317, 19.475]), Akan ethnicity (AOR = 1.576, OR = 1.437, 95 % CI_AOR = [0.307, 8.091], 95 % CI_OR = [0.316, 6.534]), having no disability (AOR = 1.099, OR = 1.138, 95 % CI_AOR = [0.679, 1.581], 95 % CI_OR = [0.786, 1.649]) and having a close relationship with parents (AOR = 1.334, OR = 1.752, 95 % CI_AOR = [0.746, 2.385], 95 % CI_OR = [1.096, 2.802]).

CONCLUSION

Knowledge of the risk and protective factors identified in this study can guide and inform the development of CSA prevention programmes during disruptive occurrences like school closures and lockdown.

Ku-band multichannel frequency comb Doppler reflectometer on the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror

A Ku-band (12-18 GHz) multichannel Doppler reflectometer (DR) has been developed in the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror device to improve the applicability of DR measurement for simultaneous monitoring of velocity of electron density turbulence at different locations. Our previous single-channel DR circuit has been replaced by the multichannel microwave system using a nonlinear transmission line based comb generator with heterodyne technique. The multichannel DR system has been installed in the central cell of GAMMA 10/PDX. Initial results of application to GAMMA 10/PDX plasma are presented, showing Doppler frequency shifts during an additional ion cyclotron resonance frequency heating and gas-puffing experiment.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX

In the GAMMA 10/PDX tandem mirror, plasma with strong ion-temperature anisotropy is produced by using the ion cyclotron range of frequency waves. This anisotropy of ion temperature causes several Alfvén-Ion-Cyclotron (AIC) waves to spontaneously excite in the frequency range just below the ion cyclotron frequency. In addition, difference-frequency (DF) waves are excited in the radial inner region of the plasma by wave-wave coupling among the AIC waves. The radial density profiles were measured at multi-axial positions using a frequency-modulation reflectometer with an axial array of microwave antennas, and an axial variation of the density was found to be significant. In addition, a relative phase difference of the DF wave between axially separated two points was first obtained by finely choosing the probing frequency of the reflectometers with a maximum coherence used as a measure, indicating that the DF wave is a propagating wave, while the pump AIC waves are standing waves in the axial region of measurement.

Improvement in multipass Thomson scattering system comprising laser amplification system developed in GAMMA 10/PDX

The multipass Thomson scattering (MPTS) technique is one of the most useful methods for measuring low-electron-density plasmas. The MPTS system increases Thomson scattering (TS) signal intensities by integrating all multipass (MP) signals and improving the TS time resolution by analyzing each pass signal. The fully coaxial MPTS system developed in GAMMA 10/potential-control and diverter-simulator experiments has a polarization-based configuration with image-relaying optics. The MPTS system can enhance Thomson scattered signals for improving the measurement accuracy and megahertz-order time resolution. In this study, we develop a new MPTS system comprising a laser amplification system to obtain continuous MP signals. The laser amplification system can improve degraded laser power and return an amplified laser to the MP system. We obtain continuous MP signals from the laser amplification system by improving the laser beam profile adjuster in gas scattering experiments. Moreover, we demonstrate that more MP signals and stronger amplified MP signals can be achieved via multiple laser injections to the laser amplification system in the developed MP system comprising a laser amplification system.

Long Term Follow-Up of Prototheca keratitis: A Case Report

Background

Prototheca spp. are rare human pathogens, and only three cases of Prototheca keratitis have been reported. They were treated with anti-fungal drugs and surgical excision. Two of the three cases were successful, and the case of an immunocompromised patient was not successful. Thus, the best treatment of Prototheca keratitis is still undetermined, and further investigations are needed. The purpose of this report is to present our findings in a case of Prototheca keratitis that was successfully treated with topical medications without surgical excision.

Methods

This study was performed in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Hidaka Medical Center, Toyooka Hospital. A written informed consent was obtained from the patient before beginning the medical treatments.

Case Report

A 75-year-old man with a history of stage 4 prostate carcinoma and bilateral limbal stem cell deficiency had undergone keratoepithelioplasty on his left eye for the deficiency. Postoperatively, a greyish-white epithelial opacity was noted on the central cornea of his left eye, and he had been treated with topical fluorometholone and oral dexamethasone together with a therapeutic contact lens. Corneal smears and contact lens swabs were positive for Prototheca spp. He required a continuous treatment with amphotericin B (AMPH-B) ointment, topical fluconazole (FLCZ), and voriconazole (VRCZ). This treatment protocol was effective, but recurrences developed when his general condition worsened.

Conclusion

Our findings indicate that Prototheca keratitis can be successfully treated but not cured with topical AMPH-B, FLCZ, and VRCZ without surgical treatment. However, recurrences can develop when the general condition of the patient worsens. Thus, continuous monitoring and treatment are necessary in cases of Prototheca keratitis.

Characteristics of pachychoroid neovasculopathy

Recently, several research groups have reported a newly recognized clinical entity of choroidal neovascularization, termed pachychoroid neovasculopathy. However, its characteristics have yet to be well described. The purpose of this study was to investigate the clinical and genetic characteristics of pachychoroid neovasculopathy regardless of treatment modality. This study included 99 eyes of 99 patients with treatment-naïve pachychoroid neovasculopathy. Mean initial best-corrected visual acuity (BCVA) was 0.20 ± 0.32 logMAR, and did not change (P = 0.725) during follow-up period (mean ± SD, 37.0 ± 17.6 months). Subretinal hemorrhage (SRH) (≥ 4 disc areas in size) occurred in 20 eyes (20.2%) during follow-up. Age, initial BCVA, central retinal thickness, SRH (≥ 4 disc areas in size) and treatment (aflibercept monotherapy) were significantly associated with the final BCVA (P = 0.024, < 0.001, 0.031, < 0.001, and 0.029, respectively). Multiple regression analysis showed initial BCVA and presence of SRH to be significant predictors of final BCVA (both P < 0.001). Polypoidal lesions were more common in the SRH group than in the non-SRH group (85.0% vs 48.1%, P = 0.004). There was no significant difference in the frequency of the risk allele in ARMS2 A69S, CFH I62V, CFH Y402H between these groups (P = 0.42, 0.77, and 0.85, respectively). SRH (29.1% vs 9.1%, P = 0.014) and choroidal vascular hyperpermiability (65.5% vs 43.2%, P = 0.027) were seen more frequently in the polypoidal lesion (+) group than in the polypoidal lesion (−) group. There was considerable variation in lesion size and visual function in patients with pachychoroid neovasculopathy, and initial BCVA and presence of SRH at the initial visit or during the follow-up period were significant predictors of final BCVA.

Collisional formation of top-shaped asteroids and implications for the origins of Ryugu and Bennu

Asteroid shapes and hydration levels can serve as tracers of their history and origin. For instance, the asteroids (162173) Ryugu and (101955) Bennu have an oblate spheroidal shape with a pronounced equator, but contain different surface hydration levels. Here we show, through numerical simulations of large asteroid disruptions, that oblate spheroids, some of which have a pronounced equator defining a spinning top shape, can form directly through gravitational reaccumulation. We further show that rubble piles formed in a single disruption can have similar porosities but variable degrees of hydration. The direct formation of top shapes from single disruption alone can explain the relatively old crater-retention ages of the equatorial features of Ryugu and Bennu. Two separate parent-body disruptions are not necessarily required to explain their different hydration levels.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites

The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu's surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

Oral function and vertical jump height among healthy older people in Japan

OBJECTIVE

Vertical jump height and oral function affect the general muscle condition. This study aimed to evaluate the association between vertical jump height and oral function among healthy older individuals.

BASIC RESEARCH DESIGN

Cross-sectional analytic study.

PARTICIPANTS

231 independent older people (mean age, 74.4 ± 5.6 years) who participated in the Kyoto Elders Physical Fitness Measurement Research Project. Individuals with partial or complete edentulousness who did not use a prosthetic device or complained of oral/maxillofacial pain were excluded from the study.

INTERVENTIONS

Grip strength was measured using a Smedley Hand Dynamometer. To measure masticatory performance, the participants were instructed to chew a gummy jelly on their habitual chewing side (left or right) for 20 s. Occlusal force, contact area, and pressure were also assessed.

MAIN OUTCOME MEASURES

The outcome variable was vertical jump height. The predictor variables were physical status (age, body mass index, and grip strength), oral status (number of present teeth and denture use), and oral function (masticatory performance, occlusal force, occlusal contact area, occlusal pressure, and tongue pressure). These relationships were evaluated with univariate analysis, and then multiple regression analysis was performed with age as the covariate for each male and female participant.

RESULTS

Vertical jump height was significantly associated with grip strength in both men and women. Moreover, in women, it was associated with masticatory performance, occlusal force, and occlusal contact area.

CONCLUSIONS

Vertical jump height was closely associated with oral function among healthy older women.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy

The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu's surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Abnormal Outer Choroidal Vasculature in Amblyopia

PURPOSE

Several studies have indicated morphological changes in the choroid in amblyopia cases. This study investigates whether choroidal vasculature was different among amblyopic and fellow eyes in unilateral amblyopia patients and healthy eyes, using en face images acquired via swept-source optical coherence tomography (SS-OCT).

DESIGN

Prospective, observational case-control study.

METHODS

This study included 14 consecutive patients with unilateral amblyopia and 22 age- and axial length-matched healthy eyes. Using SS-OCT, we obtained en face images of choroidal vasculature midway through the subfoveal inner and total choroid, corresponding to the vasculature of the choriocapillaris and Sattler's layer (inner choroid) and Haller's layer (outer choroid), respectively. We analyzed the en face images of the inner and outer choroidal vascular areas in 3 × 3 mm squares adjusted from 6 × 6 mm squares, using Littmann's magnification correction, after binarization of the images as a portion of the whole area.

RESULTS

The outer choroidal vascular areas were larger in both amblyopic and fellow eyes than in healthy eyes (both P < 0.001), although there were no significant differences in inner (56.35 ± 2.46% and 56.27 ± 3.75%, respectively) or outer (61.49 ± 4.95% and 61.48 ± 3.73%, respectively) choroidal vascular area between amblyopic and fellow eyes (P=0.98  and  0.91, respectively). An outer choroidal vascular area of 59% was set as an appropriate cutoff value for distinguishing patients from controls.

CONCLUSIONS

The outer choroidal vascular area was larger in both amblyopic eyes and fellow eyes compared to healthy eyes. Our findings may help clarify the etiology of amblyopia.

Age-related change and sex difference over 60s in disc-fovea angle in Japanese population: the Nagahama Study

PURPOSE

To analyse the disc-fovea angle (DFA) by age group and to compare sex differences in each age group in a large cohort population.

METHODS

This community-based cross-sectional cohort study included 9682 eyes of 9682 volunteers (aged 30-75 years). We measured the DFA, which is the angle between a horizontal line and a line connecting the fovea with the centroid of an optic disc on fundus photographs of the right eye. We manually marked the fovea and surrounded the optic disc. The centroid of an optic disc and the DFA was automatically calculated using originally developed software. We compared the DFA between age groups in 10-year increments and investigated sex differences of DFA in each age group.

RESULTS

Overall mean DFA was 6.32 ± 3.53°. The DFA of older subjects was significantly larger than that of younger subjects (p < 0.001). The DFA of women was larger than that of men in their 60s and 70s (p < 0.001 for both), but not in subjects in their 30s, 40s and 50s.

CONCLUSION

Larger DFA in women than in men in their 60s and 70s suggests the possibility that age-related excyclo-shift occurs more easily in postmenopausal women compared to men of the same age.

Development of a laser amplification system for the multi-pass Thomson scattering system for GAMMA 10/PDX

The multi-pass Thomson scattering (MPTS) system is a useful technique for increasing the Thomson scattering (TS) signal intensities and improving the TS diagnostic time resolution. The MPTS system developed in GAMMA 10/PDX has a polarization-based configuration with an image relaying system. The MPTS system has been constructed for enhancing the Thomson scattered signals for the improvement of measurement accuracy and the megahertz sampling time resolution. However, in the normal MPTS system, the MPTS signal intensities decrease with the pass number because of the damping due to the optical components. Subsequently, we have developed a new MPTS system with the laser amplification system. The laser amplification system can improve the degraded laser power after six passes in the multi-pass system to the initial laser power. For the first time worldwide, we successfully obtained the continued multi-pass signals after the laser amplification system in the gas scattering experiments.

Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography

This study evaluated the morphological change in aqueous humor outflow (AHO) pathways using swept-source optical coherence tomography (SS-OCT) volumetric scans in glaucoma patients before and after glaucoma surgery. In this prospective observational case series, 15 eyes (13 patients) with glaucoma were treated with 120-degree Trabectome or 360-degree suture trabeculotomy and followed up for 3 months. B-scan images of the posttrabecular AHO pathway were reconstructed and the pathway areas were evaluated, before and after surgery. Changes in posttrabecular AHO pathway were qualitatively classified as “increased”, “non-significant change”, and “decreased” on reconstructed B-scan images. Quantitative measurements of the posttrabecular AHO pathway areas were performed pre- and postoperatively. Factors associated with both qualitative and quantitative changes in AHO pathway were investigated. From 30 regions (15 nasal and 15 temporal regions) in the 15 eyes, AHO pathways were analyzable in 20 regions pre- and postoperatively. Qualitative assessments of the pathway changes were “increased” in 8 regions, “non-significant change” in 9 regions, and “decreased” in 3 regions. Quantitative assessments of the average pathway area did not change significantly (from 3155±1633 pixels preoperatively to 3212±1684 pixels postoperatively, P = 0.50). All parameters relating to intraocular pressure changes or the surgical location were not associated with postoperative AHO pathway change. The intrascleral AHO pathway could be well visualized in glaucoma patients pre- and postoperatively using swept-source optical coherence tomography. However, structural changes in the AHO pathway assessed by SS-OCT were not significant after trabecular-targeted glaucoma surgery. Functional assessments of AHO are needed in future studies.

Five-year visual outcomes after anti-VEGF therapy with or without photodynamic therapy for polypoidal choroidal vasculopathy

BACKGROUND/AIMS

To evaluate the 5-year visual and anatomical outcomes after anti-vascular endothelial growth factor (VEGF) therapy alone or in combination with photodynamic therapy (PDT), followed by pro re nata (PRN) anti-VEGF therapy with or without PDT, for polypoidal choroidal vasculopathy (PCV).

METHODS

This retrospective, observational study included 61 consecutive patients with treatment-naïve symptomatic PCV who were followed for 5 years. Twenty eyes (20 patients) initially received PDT and intravitreal injection of ranibizumab (IVR), followed by a PRN regimen of anti-VEGF therapy with or without PDT (combination group), while 41 eyes (41 patients) initially received only IVR every 3 months, followed by a PRN regimen of anti-VEGF monotherapy (IVR group). Macular atrophy including the fovea was confirmed using colour fundus photography and spectral-domain optical coherence tomography.

RESULTS

In both groups, the visual acuity (VA) at 1 year was better than the baseline VA, whereas the 3-year, 4-year and 5-year VA values were similar to the baseline VA. There was no significant difference in the 5-year VA, 5-year central retinal thickness and incidence of macular atrophy between the two groups (p=0.63, 0.72 and 0.06, respectively). In the combination group, the 5-year VA was correlated with the 5-year incidence of macular atrophy (p=0.02, r=0.51).

CONCLUSIONS

A PRN regimen for PCV may have a limited effect for the long-term maintenance of improved VA. Macular atrophy may occur more frequently with combination therapy and is possibly associated with the 5-year VA. Thus, combination therapy should be carefully selected for patients susceptible to macular atrophy.

Outcome of autologous bone grafting with preservation of articular cartilage to treat osteochondral lesions of the talus with large associated subchondral cysts

Aims

The aim of this study was to evaluate antegrade autologous bone grafting with the preservation of articular cartilage in the treatment of symptomatic osteochondral lesions of the talus with subchondral cysts.

Patients and Methods

The study involved seven men and five women; their mean age was 35.9 years (14 to 70). All lesions included full-thickness articular cartilage extending through subchondral bone and were associated with subchondral cysts. Medial lesions were exposed through an oblique medial malleolar osteotomy, and one lateral lesion was exposed by expanding an anterolateral arthroscopic portal. After refreshing the subchondral cyst, it was grafted with autologous cancellous bone from the distal tibial metaphysis. The fragments of cartilage were fixed with 5-0 nylon sutures to the surrounding cartilage. Function was assessed at a mean follow-up of 25.3 months (15 to 50), using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot outcome score. The radiological outcome was assessed using MRI and CT scans.

Results

The mean AOFAS score improved from 65.7 (47 to 81) preoperatively to 92 (90 to 100) at final follow-up, with 100% patient satisfaction. The radiolucent area of the cysts almost disappeared on plain radiographs in all patients immediately after surgery, and there were no recurrences at the most recent follow-up. The medial malleolar screws were removed in seven patients, although none had symptoms. At this time, further arthroscopy was undertaken, when it was found that the mean International Cartilage Repair Society (ICRS) arthroscopic score represented near-normal cartilage.

Conclusion

Autologous bone grafting with fixation of chondral fragments preserves the original cartilage in the short term, and could be considered in the treatment for adult patients with symptomatic osteochondral defect and subchondral cysts. Cite this article: Bone Joint J 2018;100-B:590-5.

CCDC102B confers risk of low vision and blindness in high myopia

The incidence of high myopia is increasing worldwide with myopic maculopathy, a complication of myopia, often progressing to blindness. Our two-stage genome-wide association study of myopic maculopathy identifies a susceptibility locus at rs11873439 in an intron of CCDC102B (P = 1.77 × 10⁻¹² and P_corr = 1.61 × 10⁻¹⁰). In contrast, this SNP is not significantly associated with myopia itself. The association between rs11873439 and myopic maculopathy is further confirmed in 2317 highly myopic patients (P = 2.40 × 10⁻⁶ and P_corr = 1.72 × 10⁻⁴). CCDC102B is strongly expressed in the retinal pigment epithelium and choroids, where atrophic changes initially occur in myopic maculopathy. The development of myopic maculopathy thus likely exhibits a unique background apart from the development of myopia itself; elucidation of the roles of CCDC102B in myopic maculopathy development may thus provide insights into preventive methods for blindness in patients with high myopia.

Myopic maculopathy is a complication of myopia that often progresses to blindness. Here, in a genome-wide association study, Hosoda et al. find that rs11873439 intronic to CCDC102B is associated with myopic maculopathy, but not with myopia, thus representing a risk factor independent of myopia.

Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population. After combining the genome-wide association study and the two replication sets, we identified 11 POAG-associated loci, including 4 known (CDKN2B-AS1, ABCA1, SIX6 and AFAP1) and 7 novel loci (FNDC3B, ANKRD55-MAP3K1, LMX1B, LHPP, HMGA2, MEIS2 and LOXL1) at a genome-wide significance level (P < 5.0×10-8), bringing the total number of POAG-susceptibility loci to 22. The 7 novel variants were subsequently evaluated in a multiethnic population comprising non-Japanese East Asians (1008 cases, 591 controls), Europeans (5008 cases, 35 472 controls) and Africans (2341 cases, 2037 controls). The candidate genes located within the new loci were related to ocular development (LMX1B, HMGA2 and MAP3K1) and glaucoma-related phenotypes (FNDC3B, LMX1B and LOXL1). Pathway analysis suggested epidermal growth factor receptor signaling might be involved in POAG pathogenesis. Genetic correlation analysis revealed the relationships between POAG and systemic diseases, including type 2 diabetes and cardiovascular diseases. These results improve our understanding of the genetic factors that affect the risk of developing POAG and provide new insight into the genetic architecture of POAG in Asians.

Efficacy and safety of anti-CD20 antibody rituximab for patients with refractory systemic lupus erythematosus

Objective

We examined the efficacy and safety of rituximab in patients with refractory systemic lupus erythematosus (SLE).

Methods

The study enrolled 63 SLE patients who were treated with rituximab between 2002 and 2015. The participants underwent a battery of tests before treatment and at one year. Treatment ranged from two to four times at 500 or 1000 mg.

Results

Baseline characteristics were males:females = 6:57, age 33.9 years, and disease duration 87.2 months. The primary endpoint: The rate of major clinical response (MCR) was 60% while the partial clinical response (PCR) was 25%. Thirty of 36 (83%) patients with lupus nephritis (WHO II: 2, III: 5, IV: 22, V: 4, IV+V: 2, not assessed: 1) and 22 of 24 patients (92%) with neuropsychiatric SLE, who could be followed at one year, showed changes from BILAG A or B score to C or D score at one year. Multivariate analysis identified high anti-dsDNA antibody and shorter disease duration as significant determinants of MCR at one year. Repeat examination was conducted at five years. Primary failure was recorded in 8.8% and secondary failure in 32.4% (time to relapse: 24.4 months). Rituximab was well tolerated although 65 adverse events, mostly infections, were recorded within one year.

Conclusion

Rituximab is potentially efficacious for the treatment of patients with refractory SLE.

A case of refractory lupus nephritis complicated by psoriasis vulgaris that was controlled with secukinumab

It has been reported that T helper 17 cells are involved in the pathogenesis of systemic lupus erythematosus, but there is no report on interleukin-17-targeted therapy. We report a case of a 62-year-old female who presented with psoriasis vulgaris and refractory lupus nephritis. Because her conditions were resistant to conventional treatment, and flow cytometry confirmed the proliferation of activated T helper 17 cells in peripheral blood, and examination of a renal biopsy tissue sample confirmed infiltration of numerous interleukin-17-positive lymphocytes to the renal interstitium, administration of the anti-interleukin-17A antibody secukinumab was initiated. After starting secukinumab the clinical and biological features were improved.

Recurrent Spindle Cell Carcinoma Shows Features of Mesenchymal Stem Cells

This study investigated a case of spindle cell carcinoma (SpCC) in tongue pathological lesions. The patient experienced a local recurrence and distant metastasis after surgical intervention. Although standard chemotherapy was administered, a granulomatous mass continued to develop. This aggressive growth led to survival of the tumor. Secondary debulking surgery was performed to improve the patient's quality of life at the request of the patient. Using a tissue sample derived from the secondary debulking surgery, we performed an analysis of the tumor's cell surface antigens, differentiation potential, metastatic ability, and inhibition potential by anticancer reagents. In vitro analysis revealed that the cell population grown under adherent culture conditions expressed the mesenchymal stem cell (MSC) markers CD73, CD90, and CD105. The cell line established from this SpCC contained colony-forming unit fibroblasts (CFU-Fs) and exhibited multipotent differentiation into several mesenchymal lineages, including bone, cartilage, and fat. The SpCC cells also displayed vigorous mobilization. These characteristics suggested that they had the differentiation potential of mesenchymal cells, especially MSCs, rather than that of epithelial cells. The surgical specimen analyzed in this study resisted the molecular target reagent cetuximab, which is an epidermal growth factor receptor inhibitor. This clinical insight revealed that chemotherapy-resistant SpCC cells have different characteristics compared to most other cancer cells, which are sensitive to cetuximab. Our cell death assay revealed that SpCC cell death was induced by the anticancer drug imatinib, which is known to inhibit protein tyrosine kinase activity of ABL, platelet-derived growth factor receptor α (PDGFRα), and KIT. Here, we report recurrent SpCC with characteristics of MSCs and potential for treatment with imatinib.

Association of Bruch's membrane opening and optic disc morphology to axial length and visual field defects in eyes with primary open-angle glaucoma

PURPOSE

To examine the morphology of Bruch's membrane opening (BMO), optic disc, and peripapillary atrophy (PPA) by scanning laser ophthalmoscopy (SLO) and spectral-domain optical coherence tomography (SD-OCT), and to determine their association with the axial length and visual field defects.

METHODS

This was a cross-sectional study of 94 eyes of 56 subjects; 77 eyes were diagnosed with primary open-angle glaucoma and 17 eyes as normal. The margins of the optic disc were determined in the SLO images, and that of the BMO in the SD-OCT images. The ovality and area of the BMO and the optic disc were measured. The beta and gamma-PPA areas were also measured. The association of each parameter with the axial length and the mean deviation (MD) of the visual field tests was determined by generalized estimating equations (GEEs).

RESULTS

The optic disc ovality was associated with the axial length and the MD (β = -0.47, P = 7.6 × 10^-4 and β = 0.12, P = 0.040). The BMO ovality was not significantly associated with the axial length and the MD. The BMO area was associated with the axial length (β = 0.30, P = 0.029). A larger BMO area was associated with a thinner BMO-based neuroretinal rim width (BMO-MRW) after adjustments for the MD (β = -0.30, P = 2.1 × 10^-4). The beta- and gamma-PPA areas were associated with the axial length (β = 0.50, P = 7.4 × 10^-5 and β = 0.62, P = 4.2 × 10^-6).

CONCLUSIONS

The optic disc ovality was associated with both the axial length and MD, whereas BMO ovality was not. Attention should be paid to the influence of the axial length-related enlargement of the BMO.

Choriocapillaris flow deficit in Bietti crystalline dystrophy detected using optical coherence tomography angiography

Background/Aims

This study aimed to evaluate blood flow in the choriocapillaris in patients with Bietti crystalline dystrophy (BCD) with CYP4V2 mutations using optical coherence tomography angiography (OCTA), and to explore the parameters associated with visual function.

Methods

This prospective case-series study included 13 eyes of 13 consecutive patients with BCD with CYP4V2 mutations and 20 healthy eyes. Using OCTA, we obtained en face images of blood flow in the choriocapillaris. The residual choriocapillaris area on en face images in a 10°×10° macular cube was manually measured and graded according to whether the choriocapillaris remained at the subfovea. We also investigated factors associated with visual acuity (VA) and the mean deviation (MD) value using a Humphrey field analyser with a 10–2 Swedish Interactive Threshold Algorithm standard program among OCTA-derived parameters.

Results

Choriocapillaris blood flow deficit was observed in 12 eyes (92%), whereas this was observed in none of healthy eyes. The adjusted residual choriocapillaris area was 2.47±1.79 mm2. The presence of the choriocapillaris at the subfovea was significantly correlated with VA and the MD value (P=0.006, r=0.71; P=0.04, r=−0.59, respectively).

Conclusions

Using OCTA, choriocapillaris blood flow deficit could be observed in most patients with BCD with CYP4V2 mutations. The presence of the choriocapillaris at the subfovea was significantly correlated with visual function in these patients. Analysis of choriocapillaris blood flow using OCTA allows non-invasive assessment of the patient’s state.

Predictive factors for corrective effect of inferior rectus recession for congenital superior oblique palsy

PURPOSE

To identify preoperative factors associated with the surgical corrective effect of contralateral inferior rectus recession (IRR) for vertical deviation in patients with congenital superior oblique palsy (SOP).

METHODS

This retrospective study included 20 treatment-naïve patients with unilateral congenital SOP (age range, 6-79 years) who underwent contralateral IRR according to our basic policy to select IRR for paretic eye fixation. The corrective effect (°/mm) of IRR was defined as the difference in the vertical deviation at the primary gaze position between before and 6-18 months after surgery per distance of recession. We also measured the preoperative vertical deviation at primary and secondary gaze positions, and vertical deviation with head-tilting, and calculated the difference in vertical deviation between these positions. We analyzed the correlation between the corrective effect of IRR and these study parameters.

RESULTS

The mean corrective effect of IRR was 2.4 ± 1.6°/mm, which had a significant correlation with preoperative differences in vertical deviation between the primary gaze position and the downward (P = 0.004, r = -0.61) and contralateral gaze positions (P = 0.03, r = -0.48); and the presence of preoperative stereopsis (P = 0.02, r = -0.51). After excluding a statistical outlier, the correlation between the corrective effect and the difference between the primary and contralateral gaze positions was no longer significant (P = 0.07), while the other two relationships remained significant.

CONCLUSIONS

Our findings suggest that preoperative differences in vertical deviation between the primary and downward gaze positions and the presence of preoperative stereopsis are important considerations prior to performing IRR for congenital SOP, particularly with paretic eye fixation.

A prospective multicenter study on genome wide associations to ranibizumab treatment outcome for age-related macular degeneration

We conducted a genome-wide association study (GWAS) on the outcome of anti-VEGF treatment for exudative age-related macular degeneration (AMD) in a prospective cohort. Four hundred and sixty-one treatment-naïve AMD patients were recruited at 13 clinical centers and all patients were treated with 3 monthly injections of ranibizumab followed by pro re nata regimen treatment for one year. Genomic DNA was collected from all patients for a 2-stage GWAS on achieving dry macula after the initial treatment, the requirement for an additional treatment, and visual acuity changes during the 12-month observation period. In addition, we evaluated 9 single-nucleotide polymorphisms (SNPs) in 8 previously reported AMD-related genes for their associations with treatment outcome. The discovery stage with 256 patients evaluated 8,480,849 SNPs, but no SNPs showed genome-wide level significance in association with treatment outcomes. Although SNPs with P-values of <5 × 10⁻⁶ were evaluated in replication samples of 205 patients, no SNP was significantly associated with treatment outcomes. Among AMD-susceptibility genes, rs10490924 in ARMS2/HTRA1 was significantly associated with additional treatment requirement in the discovery stage (P = 0.0023), and pooled analysis with the replication stage further confirmed this association (P = 0.0013). ARMS2/HTRA1 polymorphism might be able to predict the frequency of injection after initial ranibizumab treatment.