Multiple branch retinal artery occlusions following the new facial cosmetic filler (Poly-D, L-lactic Acid) injection a case report

BACKGROUND

Poly-D, L-lactic acid is (PDLLA) a new cosmetic filler. We reported the first case of PDLLA-related devastating complication of multiple branch retinal artery occlusion (BRAO).

CASE PRESENTATION

A 23-year-old female had sudden blindness after injection of PDLLA at the glabella. After emergency intraocular pressure-lowering medicine, ocular massage, steroid pulse therapy, heparin and alprostadil infusion, and subsequent treatments including acupuncture and 40 sessions of hyperbaric oxygen therapy, her best-corrected visual acuity improved from hand motion at 30 cm to 0.3 within 2 months.

CONCLUSION

Although safety of PDLLA was evaluated in animal studies and in 16,000 human cases, it could still cause rare but devastating retinal artery occlusion as in the present case. Proper and immediate therapies could still improve patient's vision and scotoma. Surgeons should keep in mind the possibility of iatrogenic filler-related retinal artery occlusion.

Cell size and actin architecture determine force generation in optogenetically activated cells

Adherent cells use actomyosin contractility to generate mechanical force and to sense the physical properties of their environment, with dramatic consequences for migration, division, differentiation, and fate. However, the organization of the actomyosin system within cells is highly variable, with its assembly and function being controlled by small GTPases from the Rho family. To understand better how activation of these regulators translates into cell-scale force generation in the context of different physical environments, here we combine recent advances in non-neuronal optogenetics with micropatterning and traction force microscopy on soft elastic substrates. We find that, after whole-cell RhoA activation by the CRY2/CIBN optogenetic system with a short pulse of 100 ms, single cells contract on a minute timescale in proportion to their original traction force, before returning to their original tension setpoint with near perfect precision, on a longer timescale of several minutes. To decouple the biochemical and mechanical elements of this response, we introduce a mathematical model that is parametrized by fits to the dynamics of the substrate deformation energy. We find that the RhoA response builds up quickly on a timescale of 20 s, but decays slowly on a timescale of 50 s. The larger the cells and the more polarized their actin cytoskeleton, the more substrate deformation energy is generated. RhoA activation starts to saturate if optogenetic pulse length exceeds 50 ms, revealing the intrinsic limits of biochemical activation. Together our results suggest that adherent cells establish tensional homeostasis by the RhoA system, but that the setpoint and the dynamics around it are strongly determined by cell size and the architecture of the actin cytoskeleton, which both are controlled by the extracellular environment.

CMV Retinitis with Panretinal Occlusive Vasculitis

PURPOSE

To report the clinical features of cytomegalovirus (CMV) retinitis with panretinal occlusive vasculitis.

METHODS

Retrospective case series.

RESULTS

Four eyes in 3 non-HIV patients (male: female = 3:0) were included. Previous medical history included diabetes mellitus (n = 2), age-related macular degeneration (n = 1), and Multiple myeloma under chemotherapy (n = 1). All patients were treated with oral valganciclovir and intravitreal ganciclovir. Slow resolution of retinitis related retinal opacification was noted in all 4 eyes. Two eyes had anti-viral agents discontinued despite the persistent retinitis related opacification and the lesions slowly resolved in the following months. The final decimal visual acuity was equal to or worse than 0.02 in 3 of the 4 eyes.

CONCLUSION

In eyes of CMV retinitis with panretinal occlusive vasculitis, rapid resolution of retinitis lesions is an unreliable sign evaluating the therapeutic efficacy of anti-viral agents. Besides, despite treatment of anti-viral agents, deteriorating vascular occlusion may further endanger macular function.

Short-term anatomic response of the choroid to tropicamide in myopic patients

We aimed to investigate how tropicamide alters subfoveal choroidal thickness (SFChT) and choriocapillaris flow density (CD) and determine the predictive factors of choroid thickness and vascular density in myopic eyes. This retrospective study was conducted from September 2018 to March 2019. SFChT was measured with enhanced depth spectrum-domain optical coherence tomography. The choriocapillaris was imaged using optical coherence tomography angiograms. Ocular parameters were measured thirty minutes before and after 1% tropicamide instillation. Twenty-five eyes of 15 patients (mean age 38.12 ± 6.35 years old and refractive error-8.57 ± 3.37 D) met the study criteria. The baseline linear regression model showed an association of thinner choroid with older age (P = .027) and high myopic patients (P = .001). Tropicamide substantially increased SFChT (P = .001), but had no significant influence on CD (P = .526). Moreover, SFChT variation after tropicamide instillation positively correlated with diopter changes in spherical equivalent (P = .005) and percentage changes in CD (P = .046). In myopic eyes, choroidal layer thickened substantially in response to tropicamide. The increase of SFChT only correlates with variations in spherical equivalent and CD. Short-term tropicamide installation altered both choroid thickness and choroid microvasculature, which implies an interplay among choroidal volume, perfusion, and ciliary muscle tone.

Comparison of Choroidal Thickness, Foveal Avascular Zone, and Macular Capillary Density in Macular Edema Secondary to Branch Retinal Vein Occlusion Treated with Ranibizumab or Aflibercept-A Prospective Study

This prospective comparative case series aims to compare best-corrected visual acuity (BCVA), retinal microvasculature, and retinal structural changes in patients treated with either ranibizumab or aflibercept for macular edema (ME) secondary to treatment-naïve branch retinal vein occlusion (BRVO) by optical coherence tomography angiography (OCTA). Ten patients were enrolled with macular capillary density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) and foveal avascular zone (FAZ) measured in both eyes before and after treatment. Final central retinal thickness and BCVA improved significantly (p < 0.05), and densities of SCP and DCP of BRVO sectors were significantly lower at baseline than fellow eye counterparts and remained persistently lower during treatment, particularly in the aflibercept group (p < 0.05). SCP density, DCP density of both BRVO sectors (p = 0.0001, p < 0.0001), and non-BRVO sectors (p < 0.0001, p < 0.0001) were significantly correlated with final BCVA for diseased eyes. Using multivariate general linear model analysis, and including OCTA parameters only, but not all of the available clinical data, DCP density of BRVO sectors in both eyes was the most predictive factor for final visual outcome (probability p < 0.0001). OCTA offered further qualitative and quantitative evaluation of treatment-naïve BRVO. Judging by OCTA parameters, not only in the diseased eye but also in the fellow eye, DCP density of BRVO sectors was the most predictive factor of final visual outcome.

The EMA assessment of avapritinib in the treatment of gastrointestinal stromal tumours harbouring the PDGFRA D842V mutation

Avapritinib is a protein kinase inhibitor designed to selectively inhibit oncogenic KIT and platelet-derived growth factor receptor alpha (PDGFRA) mutants by targeting the active conformation of the kinase. On 24 September 2020, a marketing authorisation valid through the European Union was issued for avapritinib as treatment of adult patients with unresectable or metastatic gastrointestinal stromal tumours (GIST) harbouring the PDGFRA D842V mutation. The drug was evaluated in an open-label, phase I, first-in-human, dose-escalation, open-label study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of avapritinib in adults with unresectable or metastatic GIST. The benefit of avapritinib was observed in patients with GIST harbouring the PDGFRA D842V mutation. The overall response rate was 95% (95% confidence interval 82.3%-99.4%), with a median duration of response of 22.1 months (95% confidence interval 14.1-not estimable months). The most common adverse events were nausea, fatigue, anaemia, periorbital and face oedema, hyperbilirubinaemia, diarrhoea, vomiting, increased lacrimation, and decreased appetite. Most of the reported cognitive effects were mild memory impairment. Rarer events were cases of severe encephalopathy and intracranial or gastrointestinal bleeding. The aim of this manuscript is to summarise the scientific review of the application leading to regulatory approval in the European Union.

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Avapritinib is a protein kinase inhibitor designed to inhibit oncogenic KIT and PDGFRA mutants.

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A marketing authorisation was issued for avapritinib as treatment of patients with GIST harbouring the PDGFRA D842V mutation.

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The overall response rate was 95% (95% CI 82.3-99.4), with a median duration of response of 22.1 months (95% CI 14.1-NE).

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The most common adverse events were nausea, fatigue, anaemia, periorbital and face oedema, hyperbilirubinaemia and diarrhoea.

CT coronary angiography in Selected Group of patients with Chest pain of new onset predicts and prevents hospital admissions & Outpatient Clinic referrals

Funding Acknowledgements

Type of funding sources: None.

Introduction

NICE (National Institute of Clinical Excellence) guidelines currently recommend the use of CT coronary Angiogram (CTCA) as the initial test to investigate coronary artery disease in patients with new onset of chest pain.

Our aim was to evaluate the relationship between the CT coronary angiogram findings on index presentation, and hospital admissions and re-referral to outpatient clinics in following 2 years.

Method

Data was accrued via a retrospective analysis of electronic medical records at Sunderland Royal Hospital pertaining to patients who presented to the Rapid Access Chest Pain Clinic (RACPC) and underwent CTCA in 2017.Data included:

Presentation – Typical & atypical angina

Risk factors profile

Investigations including ECG, ECHO, CTCA, perfusion scan and invasive coronary angiography

Severity of coronary artery lesion on CTCA

Hospital admissions or re-referral to outpatient clinics in 2 year follow up

Results

In the 235 patients studied, mean age was 56 years with 130 (55.5%) men and 195 (82.9%) presented with atypical angina as shown in table.

Out of 195 patients with atypical chest pain only 17 (8.7%) were diabetics and most of them 178 (91%) had Coronary Calcium score of 1-400. Most patients (184) underwent CT coronary angiogram with 39 (21%) having normal coronary arteries, 126 (68%) with mild to moderate coronary artery disease and 19 (11%) with severe coronary artery disease. Subsequent assessments with invasive coronary angiography, myocardial perfusion scan and Treadmill exercise did not reveal significant disease warranting coronary revascularization.

Patients with normal or mild -moderate CAD on CTCA 24 (15%) represented with acute chest pain (only one needed PCI) and 6 (3.5%) were referred to outpatient clinics over 2 years follow up. In patients with severe CAD on CTCA, 6 (32%) presented with acute chest pain and 4 (21%) needed PCI. Almost all patients were treated with statins and antiplatelets following CTCA results.

Conclusion

CT coronary angiography is sensitive and specific in assessment of hemodynamically significant coronary artery disease in non-diabetic patients presenting with angina in outpatient setting.

CTCA in patients with normal or mild to moderate CAD also gives confidence to the clinician and prevents further un-necessary investigation and hospital admissions/outpatient referrals.

Dynamic range and background filtering in raster image correlation spectroscopy

Raster-scan image correlation spectroscopy (RICS) enables researchers to measure molecular translational diffusion constants and concentrations from standard confocal laser scanning microscope images and is suitable for measuring a wide range of mobility, especially fast-diffusing molecules. However, as RICS analysis is based on the spatial autocorrelation function of fluorescence images, it is sensitive to the presence of fluorescent structures within the image. In this study, we investigate methods to filter out immobile or slow moving background structures and their impact on RICS results. Both the conventional moving-average subtraction-based method and cross-correlation subtraction-based method are rationalized and quantified. Simulated data and experimental measurements in living cells stress the importance of optimizing the temporal resolution of background filtering for reliable RICS measurements. Finally, the capacity of RICS analysis to separate two species is studied.

Stick-slip dynamics of cell adhesion triggers spontaneous symmetry breaking and directional migration of mesenchymal cells on one-dimensional lines

Directional cell motility relies on the ability of single cells to establish a front-rear polarity and can occur in the absence of external cues. The initiation of migration has often been attributed to the spontaneous polarization of cytoskeleton components, while the spatiotemporal evolution of cell-substrate interaction forces has yet to be resolved. Here, we establish a one-dimensional microfabricated migration assay that mimics the complex in vivo fibrillar environment while being compatible with high-resolution force measurements, quantitative microscopy, and optogenetics. Quantification of morphometric and mechanical parameters of NIH-3T3 fibroblasts and RPE1 epithelial cells reveals a generic stick-slip behavior initiated by contractility-dependent stochastic detachment of adhesive contacts at one side of the cell, which is sufficient to trigger cell motility in 1D in the absence of pre-established polarity. A theoretical model validates the crucial role of adhesion dynamics, proposing that front-rear polarity can emerge independently of a complex self-polarizing system.

Optical sensing of mechanical pressure based on diffusion measurement in polyacrylamide cell-like barometers

Diffusion and transport of small molecules within hydrogel networks are of high interest for biomedical and pharmaceutical research. Herein, using fluorescence correlation spectroscopy (FCS), we experimentally showed that the diffusion time in the hydrogel was directly related to the mechanical state (compression or swelling) and thus to the volume fraction of the gel. Following this observation, we developed cell-like barometers in the form of PAA microbeads, which when incorporated between cells and combined with a diffusion-based optical readout could serve as the first biosensors to measure the local pressure inside the growing biological tissues. To illustrate the potential of the present method, we used multicellular spheroids (MCS) as a tissue model, and it was observed that the growth-associated tissue stress was lower than 1 kPa, but significantly increased when an external compressive stress was applied.

Design of an MWW zeolite catalyst for linear alkylbenzene synthesis with improved catalytic stability

Effect of micro–meso porosity of MWW zeolites on the catalytic linear alkylbenzene synthesis was studied.

Note: multi-confocal fluorescence correlation spectroscopy in living cells using a complementary metal oxide semiconductor-single photon avalanche diode array

Living cells are heterogeneous and rapidly changing biological samples. It is thus desirable to measure molecular concentration and dynamics in many locations at the same time. In this note, we present a multi-confocal setup capable of performing simultaneous fluorescence correlation spectroscopy measurements, by focusing the spots with a spatial light modulator and acquiring data with a monolithic 32 × 32 single-photon avalanche photodiode array. A post-processing method is proposed to correct cross-talk effects between neighboring spots. We demonstrate the applicability of our system by simultaneously measuring the diffusion of free enhanced Green Fluorescent Protein (eGFP) molecules at nine different points in living cells.

SU-E-T-639: Dosimetric Evaluation of VMAT for the Treatment of NSCLC with SBRT

PURPOSE

To demonstrate the dosimetric potential of volumetric modulated arc therapy (VMAT) for the treatment of patients with medically inoperable stage I/II non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT).

METHODS

Fourteen patients treated with 3D-CRT with varying tumor locations, tumor sizes and dose fractionation schemes were chosen for study. The target prescription doses were 48 Gy in 4 fractions, 52.5 Gy in 5 fractions, 57.5 Gy in 5 fractions and 60 Gy in 3 fractions for 2, 5, 1 and 6 patients, respectively. VMAT treatment plans with a mix of 2-3 full and/or partial non-coplanar arcs with 5°-25° separations were retrospectively generated using Eclipse version 10.0. The 3D-CRT and VMAT plans were then evaluated by comparing their target dose, critical structure dose, high dose spillage, and low dose spillage as defined according to RTOG 0813 and RTOG 0236 protocols.

RESULTS

The VMAT treatment plans yielded an average 9.6-33.7% reduction in dose to critical structures and an average 12.0-12.5% increase in conformity compared with the treated 3D-CRT plans. The D2cm improved with VMAT in 11 of 14 cases. The 3 that worsened were still within the acceptance criteria. Of the 14 3D-CRT plans, 7 had a D2cm minor deviation, while only one of the 14 VMAT plans had a D2cm minor deviation. The R50% improved in 13 of the 14 VMAT cases. The 1 case that worsened was still within the acceptance criteria of the RTOG protocol. Of the 14 3D-CRT plans, 7 had an R50% deviation. Only 1 of the 14 VMAT plans had an R50% deviation, but it was still improved compared to the 3D-CRT plan.

CONCLUSIONS

In this cohort of patients, no dosimetric compromises resulted from planning SBRT treatments with VMAT relative to the 3D-CRT treatment plans actually used in their treatment.

SU-E-T-456: Potential Optimization of Stereotactic Body Radation Therapy (SBRT) from a Simple Field Timing Rearrangement

PURPOSE

Stereotactic Body Radiation Therapy (SBRT) is a radiotherapy technique which uses high dose fractions with multiple coplanar and non- coplanar beams. Treatments are typically protracted with more fields than conventional radiation treatment schemes. The timing of field delivery may have an impact on the radiobiological results for SBRT.

METHODS

In a cohort of eight SBRT patient treatments, the protraction factor (G-value), LPL, and LQL models were used to optimize field arrangements. An actual field timing delivered in the clinic (C) was included for comparison. The LPL model was used to quantify the difference in survival fractions (SF). Published data from three cell lines for non-small cell lung cancers: H460, H660, and H157 was used to acquire the model parameters. The results were displayed as (C:O)̂N or (V:O)̂N, where C, V, and O were the SF for the clinical (C), least favorable (V), and optimal (O) field timings respectively. N represents the number of fractions for the SBRT protocol.

RESULTS

Results from all three models indicate that the optimal field order occurs when the fields are arranged in a triangle like pattern, where the highest dose fields are positioned centrally. Minimization of cell kill was achieved with a V-shaped orientation, although these results were not as conclusive. Results of the SF ratios demonstrated that regardless the cell type and model the triangle shape had lower cell survival fractions compared to both the C and the V arrangement. For example, the H460, with repair half-time = 1.50 h, an average ratio of (C:O)̂3 = 5.8, suggesting the triangle pattern is approximately 6 times more effective than the clinical plan, after 3 fractions.

CONCLUSIONS

Rearranging field timing for a SBRT treatment so that maximal dose is deposited in the central fields of treatment may optimize cell kill and potentially affect overall treatment outcome.