Vision Screening Research Articles

Use of intraoral mobile photography for screening of oral health in children

Abstract Background The aim of the study is to evaluate the diagnostic accuracy of intraoral mobile photography to assess caries intensity (DMFT/deft), simplified oral hygiene index (S-OHI) and modified gingival index (MGI). Methods Children aged 7-12 were included in the study. The clinical doctor evaluated the oral health indicators by visual examination: DMFT, deft, S-OHI, MGI were calculated. Dental students independently captured photos with a mobile phone (iPhone-11) in 8 predetermined projections. Dental images were kept in coded folders for research anonymity. Another professional calculated index based on the photos. Variables were used with binary values (DMFT/deft = 0/≥1; MGI=0/≥1; S-OHI≤1.2/>1.2). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of dental photography were evaluated and Cohen’s Kappa was calculated to measure the level of agreement between two independent observers. Results 2864 photographs were evaluated for 358 participants. The sensitivity and specificity of intraoral mobile photography for DMFT index is 95.8 (95% CI: 93.4-98.3) and 89.2 (95% CI: 83-95.5); For deft index: 100.0 (95% CI: 100-100) and 88.6 (95% CI: 79.3-98); For MGI: 89.7 (95% CI: 85.8-93.5) and 91.4 (95% CI: 86.3-96.5); For S-OHI: 77.6 (95% CI: 67.6-87.6) and 93.8 (95% CI: 91-96.6); The PPV value for DMFT, deft, MGI and S-OHI is 96.2; 97.7; 95.6 and 74.3 and the NPV value is 88.3; 100.0; 80.9 and 94.8 respectively. It was achieved substantial and perfect agreement between two independent raters: For DMFT, deft, MGI, S-OHI indices Cohen’s Kappa =0.85; 0.93; 0.78; 0.70 correspondingly. Conclusions Intraoral mobile photography, if applied within appropriate guidelines is reliable for assessing caries intensity, simplified hygiene index and modified gingival index as well as visual screening and may become a priority for dental public health. The involvement of dental students in studies of similar design is appropriate. Key messages • Intraoral mobile photography can be used for oral health screening in children. • The involvement of dental program students in screening studies conducted with intraoral mobile photography is appropriate.

Integrating single-cell sequencing and genetic lineage tracing reveals endothelial plasticity during atrial remodeling

Abstract Background Atrial fibrillation (AF), as the most burdensome cardiac arrhythmia, could lead to the significant mortality and morbidity. Atrial fibrosis is a well-recognized pathophysiological factor of the development and progression of AF, which also hampers its treatment. However, the underlying mechanisms of this intricate process remain largely unknown. Purpose This study sought to reveal the cellular composition of AF substrate and investigate the vital contributors to atrial structural remodeling. Methods Left atrial appendages from three patients with AF undergoing surgical ablation and three individuals with sinus rhythm undergoing heart transplantation were subjected to 10X single-cell RNA sequencing (scRNA-seq). Another five public scRNA-seq or snRNA-seq datasets of potentially remodeled right or left appendages were retrieved across three publications. The vital contributors of atrial structural remodeling and their characteristics were identified by intercellular communication analysis and trajectory inference. Transverse aortic constriction (TAC) was used to induce atrial remodeling in Cdh5-CreERT2;RFP mice, followed by scRNA-seq of endothelial cells (ECs). Human primary atrial ECs and fibroblasts were isolated for cell-cell interaction experiments. ECs-specific mouse models of Transforming growth factor beta 1 (TGFB1) (knockout and overexpression) were generated. Electrophysiological and histology analyses were performed to determine the consequences of ECs-derived TGFB1 gain and loss of function in the atrium. Results The comprehensive analysis of different scRNA-seq datasets revealed that ECs played an important regulatory role in the homeostasis of atrial substrate and displayed remarkable mesenchymal activation during atrial remodeling, which was further confirmed by TAC mice. Immunofluorescence staining and high-content screening suggested that the complete transition from ECs to mesenchymal cells slightly contributed to atrial remodeling. However, TGFB1 secreted from mesenchymal activated ECs significantly promoted activation, proliferation, and collagen secretion of fibroblasts. We discovered that overexpression of TGFB1 in ECs of mice significantly increased atrial fibrosis, and thus prolonging AF duration. Besides, knockout of TGFB1 in ECs of mice underwent TAC significantly attenuated the atrial fibrosis and decreased the rate of AF. Conclusion Our work demonstrates that mesenchymal ECs-derived Tgfb1 plays an important role in atrial remodeling by regulating the fibroblast function. EC-specific interventions were suggested to facilitate the development of novel strategies for mitigating AF substrate remodeling.

Characterisation of the novel SCN5A-P1891A variant, implicated in left ventricular noncompaction cardiomyopathy in a Finnish family, using human induced pluripotent stem cell-derived cardiomyocytes

Abstract Introduction Left ventricular noncompaction (LVNC) is a heterogenous cardiomyopathy characterised by an extensively trabeculated left ventricle (LV). Several genetic variants that perturb trabeculae compaction, and thus LV maturation, have been reported [1]. However, the precise mechanisms underpinning this have proven contentious with, for example, differentially aberrant cardiomyocyte proliferation implicated in the development of LVNC [2,3]. Purpose In this study, we investigate a novel SCN5A variant, P1891A, which is associated with LVNC in a Finnish family. We ascertain the effects of this variant through the characterisation of variant-carrying human induced pluripotent stem cell-derived cardiomyocytes (P1891A-hiPSC-CMs). Methods We isolated dermal fibroblasts from a symptomatic member of a Finnish family carrying the SCN5A-P1891A variant; derived P1891A-hiPSCs via nucleofection with reprogramming plasmids [4]; and differentiated these into hiPSC-CMs alongside healthy control-hiPSCs. We determined the action potential (AP) and sodium- (INa) and calcium-current (ICa) densities of hiPSC-CMs via patch-clamp. We investigated gene expression in hiPSC-CMs through qPCR and employed Multiple Approaches Combined (MCA) proteomics [5] in SCN5A-transfected HEK293-like cells to elucidate protein-protein interactions (PPI). We subjected hiPSC-CMs to mechanical stretch [6] to examine their stress response and assessed their proliferation capacity via high-content analysis for the percentage of BrdU positive hiPSC-CMs following mitogenic stimulation (5 µM CHIR99021 and 1 µM SB203580). Finally, we ascertained contractile kinetics and apparent contractile force using fibrin hydrogel-based engineered heart tissues (EHTs) [7]. Results The P1891A-hiPSC-CMs demonstrated elevated INa density alongside enhanced arrhythmogenicity relative to healthy control hiPSC-CMs although, AP kinetics and ICa density were unperturbed (Fig. 1). Under baseline conditions, P1891A-hiPSC-CMs exhibited higher SCN5A gene expression and proteomics revealed a reduction in PPI. Baseline proliferation was unchanged; however, aged P1891A-hiPSC-CMs had enhanced proliferative capacity following mitogenic stimulation. Further, the P1891A-hiPSC-CMs displayed impaired tolerance to mechanical stretch as evidenced by upregulated NPPB and ACTA1 expression. In the context of the EHT, P1891A-hiPSC-CMs yielded disparate phenotypes. Whilst a subset compacted fully and yielded weaker contractile parameters relative to healthy control EHTs, the majority of P1891A-hiPSC-CM EHTs failed to fully compact thereby recapitulating the LVNC phenotype (Fig. 2). Conclusions This study presents a unique aetiology of LVNC and links, for the first time, SCN5A mutations with enhanced human cardiomyocyte proliferation. The ability to recapture the noncompaction phenotype in EHTs presents a powerful model for future mechanistic research and drug development.

Imaging‐based profiling for elucidation of antibacterial mechanisms of action

AbstractIn this review, we aim to summarize experimental data and approaches to identifying cellular targets or mechanisms of action of antibacterials based on imaging techniques. Imaging‐based profiling methods, such as bacterial cytological profiling, dynamic bacterial morphology imaging, and others, have become a useful research tool for mechanistic studies of new antibiotics as well as combinations with conventional ones and other therapeutic options. The main methodological and experimental details and obtained results are summarized and discussed. The review covers the literature up to February 2024.

Android-based framework for condition assessment of existing RC hospital buildings

Rapid visual screening (RVS) is a practically viable tool implemented all over the world to rank structures based on their seismic vulnerability. Seismic assessment of hospital buildings is essential in seismic-prone regions to ensure their structural integrity and readiness to provide emergency care and medical treatment after significant seismic events. Therefore, in the current study, an approach is developed that is similar to the proven methodologies reported in the literature, for the seismic evaluation of structural and non-structural elements of hospital buildings in a metropolitan city like Karachi. Karachi is located in the southwest of Pakistan and is vulnerable to earthquake and tsunami hazards. To this end, an android-based RVS system has been developed for large-scale seismic risk mapping of hospital buildings. The proposed system acquires the physical status of the building features in real time and identifies the building performance obtained from the calculated seismic risk index. Moreover, three case study hospital buildings were employed and analysed through the proposed RVS system. Results illustrate the performance of case study hospital buildings at organisational, structural and non-structural levels based on seismic risk indices.

Genetically Engineered Filamentous Bacteriophages Displaying TGF-β1 Promote Angiogenesis in 3D Microenvironments

Combined 3D cell culture in vitro assays with microenvironment-mimicking systems are effective for cell-based screening tests of drug and chemical toxicity. Filamentous bacteriophages have diverse applications in material science, drug delivery, tissue engineering, energy, and biosensor development. Specifically, genetically modified bacteriophages have the potential to deliver therapeutic molecules or genes to targeted tumor tissues. The engineered bacteriophages in this study significantly enhanced endothelial cell migration and tube formation within the extracellular matrix (ECM). Compared to TGF-β1 alone and non-modified phages, the presence of TGF-β1 on the bacteriophages demonstrated superior performance as a continuous stimulant in the microenvironment, effectively promoting these angiogenic processes. Assays, including RT-qPCR, ELISA, and fluorescence microscopy, confirmed the expression of angiogenic markers such as CD31, validating the formation of 3D angiogenic structures. Our findings indicate that the TGF-β1 displayed by bacteriophages likely acted as a chemotactic factor, promoting the migration, proliferation, and tube formation of endothelial cells (ECs) within the ECM. Although direct contact between ECs and bacteriophages was not explicitly confirmed, the observed effects strongly suggest that TGF-β1-RGD bacteriophages contributed to the stimulation of angiogenic processes. The formation of angiogenic structures by ECs in the ECM was confirmed as three-dimensional and regulated by the surface treatment of microfluidic channels. These results suggest that biocompatible TGF-β1-displaying bacteriophages could continuously stimulate the microenvironment in vitro for angiogenesis models. Furthermore, we demonstrated that these functionalized bacteriophages have the potential to be utilized as versatile biomaterials in the field of biomedical engineering. Similar strategies could be applied to develop angiogenic matrices for tissue engineering in in vitro assays.

Validation of a functional human AD model with four AD therapeutics utilizing patterned ipsc-derived cortical neurons integrated with microelectrode arrays

Preclinical methods are needed for screening potential Alzheimer’s disease (AD) therapeutics that recapitulate phenotypes found in the Mild Cognitive Impairment (MCI) stage or even before this stage of the disease. This would require a phenotypic system that reproduces cognitive deficits without significant neuronal cell death to mimic the clinical manifestations of AD during these stages. Long-term potentiation (LTP), which is a correlate of learning and memory, was induced in mature human iPSC-derived cortical neurons cultured on microelectrode arrays utilizing circuit patterns connecting two adjacent electrodes. We demonstrated an LTP system that modeled the MCI and pre-MCI stages of Alzheimer’s and validated this functional system utilizing four AD therapeutics, which was also verified utilizing patch-clamp electrophysiology. LTP was induced by tetanic electrical stimulation, and LTP maintenance was significantly reduced in the presence of Amyloid-Beta 42 (Aβ42) oligomers compared to the controls, however, co-treatment with AD therapeutics (Donepezil, Memantine, Rolipram and Saracatinib) corrected Aβ42-induced LTP impairment. The results illustrate the utility of the system as a validated platform to model MCI AD pathology, and potentially for the pre-MCI phase before significant neuronal death. This system also has the potential to become an ideal platform for high-content therapeutic screening for other neurodegenerative diseases.

Testing Visual Function by Assessment of the Optomotor Reflex in Glaucoma.

Optomotor response/reflex (OMR) is a fast and efficient first-in-line visual screening method, especially for rodents. It has the potential to evaluate both the scotopic and photopic visions of nonrestrained animals through tracking head movement, providing a quantitative estimate of visual functions. In restrained animals, optokinetic response (OKR), compensatory eye movements for visual shifts in the surroundings, is utilized. Both OMR and OKR capitalize on an individual's innate reflex to stabilize images for the purpose of capturing clear vision. The two reflexes have similar reliability when evaluating stimulus luminance, contrast, spatial frequency, and velocity. They have emerged as powerful tools to evaluate the efficacy of pharmacological treatments and phenotypes of subjects undergoing study. With OMR and OKR accurately assessing visual acuity (VA) as well as contrast sensitivity (CS), the gold standards for measuring clinical vision, they provide reliable and easily accessible results that further eye and brain research. These methods of sight evaluation have been used in multiple animal models, particularly mice and zebrafish. Through OMR assays, these animal models have been utilized to investigate retinal degenerative diseases, helping researchers differentiate between worsening stages. Alongside tests such as optical coherence tomography (OCT), OMR provides confirmation of visual status, where increased OMR function often correlates with improved visual status. OMR has continued to be used outside of glaucoma in various retinal diseases, such as retinitis pigmentosa (RP), diabetic retinopathy, and age-related macular degeneration.In this chapter, we will introduce the concept and application of visual stimulus-induced head or eye reflex movement in different animal species and experimental models of eye diseases, such as glaucoma and other neurodegenerative disorders, and in patients with glaucoma.

Cell-Based Screen Identifies a Highly Potent and Orally Available ABCB1 Modulator for Treatment of Multidrug Resistance.

Targeting ABCB1 is a promising strategy in combating multidrug resistance. Our cell-based phenotypic screening led to the discovery of novel triazolo[1,5-a]pyrimidone-based ABCB1 modulators. Notably, WS-917 was identified as a significant contributor to heightened sensitization of human colorectal adenocarcinoma cells (SW620/Ad300) to paclitaxel (IC50 = 5 nM). Mechanistic elucidation revealed that this compound substantially augmented intracellular paclitaxel and [3H]-paclitaxel, concurrently mitigating the efflux of [3H]-paclitaxel in SW620/Ad300 through the inhibition of ABCB1 efflux. The cellular thermal shift assay underscored its ability to stabilize ABCB1 through direct binding. Additionally, WS-917 induced stimulation of ABCB1 ATPase activity while exhibiting negligible inhibitory effect against CYP3A4. Remarkable was its capacity to enhance the sensitivity of SW620/Ad300 to paclitaxel, as well as the sensitivity of CT26/TAXOL to paclitaxel and PD-L1 inhibitor (Atezolizumab) in vivo, all achieved without inducing observable toxicity. The discovery of WS-917 holds promise for the development of more potent ABCB1 modulators.

CMS121, a Novel Drug Candidate for the Treatment of Alzheimer's Disease and Age-Related Dementia.

Old age is the major risk factor for sporadic Alzheimer's disease (AD). However, old age-related changes in brain physiology have generally not been taken into consideration in developing drug candidates for the treatment of AD. This is at least partly because the role of these age-related processes in the development and progression of AD are still not well understood. Nevertheless, we and others have described an association between the oxytosis/ferroptosis non-apoptotic regulated cell death pathway and aging. Based on this association, we incorporated protection against this pathway as part of a cell-based phenotypic screening approach to identify novel drug candidates for the treatment of AD. Using this approach, we identified the fisetin derivative CMS121 as a potent neuroprotective molecule that is able to maintain cognitive function in multiple pre-clinical models of AD. Furthermore, we identified a key target of CMS121 as fatty acid synthase, a protein which had not been previously considered in the context of AD. Herein, we provide a comprehensive description of the development of CMS121, its preclinical activities, and the results of the toxicology testing that led to its IND approval.

Targeting AGAT gene expression – a drug screening approach for the treatment of GAMT deficiency

ABSTRACT Background Targeting the enzyme L-Arginine:glycine amidinotransferase (AGAT) to reduce the formation of guanidinoacetate (GAA) in patients with guanidinoacetate methyltransferase (GAMT) deficiency, we attempted to identify drugs for repurposing that reduce the expression of AGAT via transcriptional inhibition. Research Design and Methods The authors applied a HeLa cell line stably expressing AGAT promoter and firefly luciferase reporter for high-content screening and secondary screening. For further assessment, the authors integrated Nanoluc luciferase as a reporter into the endogenous AGAT gene in HAP1 cell lines and used the human immortalized cell line RH30 as model of GAMT deficiency. Results Screening 6,000 drugs and drug-like compounds, the authors identified 43 and 34 high-score candidates as inhibitors and inducers of AGAT promoter-reporter expression, respectively. After further deselection considering dose response, drug toxicity, topical formulations, price, and accessibility, the authors assessed seven candidates and found none of them demonstrating efficacy in HAP1 and RH30 cells and warranting further assessment. Conclusion The selection of the test models is crucial for screening of gene repressor drugs. Almost all drugs with an impact on gene expression had off-target effects. It is unlikely to find drugs that are selective inhibitors of AGAT expression, rendering pharmacological AGAT gene repression a risky approach for the treatment of GAMT deficiency.

CD81-guided heterologous EVs present heterogeneous interactions with breast cancer cells

BackgroundExtracellular vesicles (EVs) are cell-secreted particles conceived as natural vehicles for intercellular communication. The capacity to entrap heterogeneous molecular cargoes and target specific cell populations through EV functionalization promises advancements in biomedical applications. However, the efficiency of the obtained EVs, the contribution of cell-exposed receptors to EV interactions, and the predictability of functional cargo release with potential sharing of high molecular weight recombinant mRNAs are crucial for advancing heterologous EVs in targeted therapy applications.MethodsIn this work, we selected the popular EV marker CD81 as a transmembrane guide for fusion proteins with a C-terminal GFP reporter encompassing or not Trastuzumab light chains targeting the HER2 receptor. We performed high-content imaging analyses to track EV-cell interactions, including isogenic breast cancer cells with manipulated HER2 expression. We validated the functional cargo delivery of recombinant EVs carrying doxorubicin upon EV-donor cell treatment. Then, we performed an in vivo study using JIMT-1 cells commonly used as HER2-refractory, trastuzumab-resistant model to detect a more than 2000 nt length recombinant mRNA in engrafted tumors.ResultsFusion proteins participated in vesicular trafficking dynamics and accumulated on secreted EVs according to their expression levels in HEK293T cells. Despite the presence of GFP, secreted EV populations retained a HER2 receptor-binding capacity and were used to track EV-cell interactions. In time-frames where the global EV distribution did not change between HER2-positive (SK-BR-3) or -negative (MDA-MB-231) breast cancer cell lines, the HER2 exposure in isogenic cells remarkably affected the tropism of heterologous EVs, demonstrating the specificity of antiHER2 EVs representing about 20% of secreted bulk vesicles. The specific interaction strongly correlated with improved cell-killing activity of doxorubicin-EVs in MDA-MB-231 ectopically expressing HER2 and reduced toxicity in SK-BR-3 with a knocked-out HER2 receptor, overcoming the effects of the free drug. Interestingly, the fusion protein-corresponding transcripts present as full-length mRNAs in recombinant EVs could reach orthotopic breast tumors in JIMT-1-xenografted mice, improving our sensitivity in detecting penetrant cargoes in tissue biopsies.ConclusionsThis study highlights the quantitative aspects underlying the creation of a platform for secreted heterologous EVs and shows the limits of single receptor-ligand interactions behind EV-cell engagement mechanisms, which now become the pivotal step to predict functional tropism and design new generations of EV-based nanovehicles.

Patterns of refractive errors and visual function in school-going children in South Africa

Background: Uncorrected refractive error is the most significant contributor of VI in children and is usually detected through vision screenings or scheduled eye and vision examinations conducted among school children.Aim: To describe patterns of refractive errors (RE), visual function and amblyopia in school-going children.Setting: Mankweng, Polokwane, South Africa.Methods: Retrospective chart reviews were conducted on 837 clinical record cards of children attending selected schools and who were screened between 2019 and 2021 at the University of Limpopo Optometry clinic. Purposive sampling was used to sample the clinical record cards.Results: About 134 children (16%) reported blurred vision, 197 (23.5%) failed distance visual acuity screening, while 173 (20.7%) had RE. Myopia among 168 (9.6%) children was the most common RE, followed by astigmatism and hyperopia at 60 (4.70%) and 28 (4.4%), respectively. Furthermore, 14 (1.7%) children had anisometropia. Amblyopia, colour vision deficiency and contrast sensitivity were also detected at prevalence rates of 4.4%, 9.8% and 8.2%, respectively.Conclusion: Vision screenings and regular comprehensive eye examinations are commonly conducted to detect and manage REs to prevent or delay the onset of amblyopia and strabismus. Children had a high prevalence of RE and amblyopia, which is similar to global estimates.Contribution: To describe the pattern of REs, amblyopia and visual function, which is critical to understand the prevalence of amblyopia and associated conditions. Knowing the patterns of these conditions may provide an impetus for the implementation of strategies such as vision screenings and vision examinations in schools.

Identification of lipid senolytics targeting senescent cells through ferroptosis induction.

Cellular senescence is a key driver of the aging process and contributes to tissue dysfunction and age-related pathologies. Senolytics have emerged as a promising therapeutic intervention to extend healthspan and treat age-related diseases. Through a senescent cell-based phenotypic drug screen, we identified a class of conjugated polyunsaturated fatty acids, specifically α-eleostearic acid and its methyl ester derivative, as novel senolytics that effectively killed a broad range of senescent cells, reduced tissue senescence, and extended healthspan in mice. Importantly, these novel lipids induced senolysis through ferroptosis, rather than apoptosis or necrosis, by exploiting elevated iron, cytosolic PUFAs and ROS levels in senescent cells. Mechanistic studies and computational analyses further revealed their key targets in the ferroptosis pathway, ACSL4, LPCAT3, and ALOX15, important for lipid-induced senolysis. This new class of ferroptosis-inducing lipid senolytics provides a novel approach to slow aging and treat age-related disease, targeting senescent cells that are primed for ferroptosis.

Rapid and Ultrasensitive Detection of H. aduncum via the RPA-CRISPR/Cas12a Platform.

Hysterothylacium aduncum is one of six pathogens responsible for human anisakiasis. Infection with H. aduncum can cause acute abdominal symptoms and allergic reactions and is prone to misdiagnosis in clinical practice. This study aims to enhance the efficiency and accuracy of detecting H. aduncum in food ingredients. We targeted the internal transcribed spacer 1 (ITS 1) regions of Anisakis to develop a visual screening method for detecting H. aduncum using recombinase polymerase amplification (RPA) combined with the CRISPR/Cas12a system. By comparing the ITS 1 region sequences of eight nematode species, we designed specific primers and CRISPR RNA (crRNA). The specificity of RPA primers was screened and evaluated, and the CRISPR system was optimized. We assessed its specificity and sensitivity and performed testing on commercial samples. The results indicated that the alternative primer ADU 1 was the most effective. The final optimized concentrations were 250 nM for Cas12a, 500 nM for crRNA, and 500 nM for ssDNA. The complete test procedure was achievable within 45 min at 37 °C, with a limit of detection (LOD) of 1.27 pg/μL. The amplified product could be directly observed using a fluorescence microscope or ultraviolet lamp. Detection results for 15 Anisakis samples were entirely consistent with those obtained via Sanger sequencing, demonstrating the higher efficacy of this method for detecting and identifying H. aduncum. This visual detection method, characterized by simple operation, visual results, high sensitivity, and specificity, meets the requirements for food safety testing and enhances monitoring efficiency.

Refractive errors, amblyopia risk factors and vision screening in children aged 7–10 years in Aotearoa New Zealand

ABSTRACT Clinical relevance Vision screening is important for detecting undiagnosed vision conditions that are common in school-aged children. However, current vision screening protocols are poor at detecting vision conditions that are most common in the Aotearoa New Zealand paediatric population. Background Uncorrected refractive error and amblyopia are the most common causes of visual impairment in children. The most appropriate vision screening method depends on the refractive error profile of the population. This study aimed to: estimate the prevalence of refractive errors and amblyopia risk factors among children living in Aotearoa New Zealand; describe previous participation in preschool vision screening and determine the diagnostic accuracy of potential screening methods. Methods Children aged 7–10 years received comprehensive eye examinations, including cycloplegic refraction, in their school. Eye examination results were assessed for refractive error and amblyopia risk factors. The sensitivity and specificity of individual vision tests for detecting any vision conditions was calculated to assess the most effective tests for vision screening. Results Eye examinations were completed for 237 children and cycloplegic refraction data was available for 220 of these children. Significant refractive error (need for glasses) was detected in 23.6% of children (7.7% myopia, 7.7% hyperopia, 15.0% astigmatism). Amblyopia risk factors were detected in 9.1% of children. Preschool vision screening had been completed by 78.5% of children. Distance visual acuity screening alone had a sensitivity of 39% for detecting vision conditions, with addition of the Spot Vision Screener improving sensitivity to 65%. Conclusion Astigmatism is the most frequent refractive error among children aged 7–10 years living in Aotearoa New Zealand. Distance visual acuity screening alone is ineffective in detecting refractive error in children in Aotearoa New Zealand. Further research investigating refractive errors across the paediatric population in Aotearoa New Zealand is required to determine the optimal timing and appropriate protocols for school-aged vision screening.

8040 Precision-Engineered Activin and GDF Ligand Trap HS235: A Novel Lean Mass-Preserving Treatment for Obesity

Abstract Disclosure: G. Schang: Employee; Self; 35Pharma. M. De Molliens: Employee; Self; 35Pharma. E. Brule: Employee; Self; 35Pharma. C. Chauvet: Employee; Self; 35Pharma. J. Denis: Employee; Self; 35Pharma. A. Sours: Employee; Self; 35Pharma. V. Ganesh: Employee; Self; 35Pharma. G. Tremblay: Employee; Self; 35Pharma. J. Schoelermann: Employee; Self; 35Pharma. M. O'Connor: Employee; Self; 35Pharma. Introduction: Novel anti-obesity medications including incretin mimetics have revolutionized the pharmacotherapy of obesity and type 2 diabetes, leading to unprecedented weight loss and clinically meaningful improvement of glucose metabolism and cardiometabolic health. However, incretins reduce body mass in a non-selective manner; both fat mass and lean mass are lost with incretin treatment. In obese patients treated with incretins, undesirable loss of lean body mass (LBM) can account for up to 40% of overall weight loss. Loss of LBM negatively impacts resting metabolic rate, leading to a weight loss plateau and often unsustainable results. Furthermore, individuals with sarcopenia, characterized by low muscle mass and strength, are at greater risk for heart failure. The preservation, or even increase, of LBM is therefore a desirable treatment goal for obesity pharmacotherapy and overall cardiometabolic health. Activins and growth differentiation factors (GDFs), which are members of the TGF-beta superfamily, are validated targets controlling body composition and metabolism. Specifically, blockade of activins and GDFs has anabolic effects in metabolically active tissues such as skeletal muscle and brown adipose tissue, while reducing white adipose tissue mass. Therefore, specific and selective blockade of activins and GDFs represents a novel anti-obesity treatment strategy which can act orthogonally to current anti-obesity medications. HS235 is an activin receptor ectodomain-based (ActR) Fc-fusion protein that has been rationally designed to attain optimal inhibition of ligands controlling body composition in obesity. Methods: A structure-assisted rational molecular engineering approach coupled with cell-based potency screening was employed to design HS235. To validate the anti-obesogenic potential of HS235, diet-induced obese (DIO) mice were injected with HS235, an incretin mimetic, or a combination of both. Fat mass, LBM, muscle weights, and biomarker readouts were assessed at the end of study. Results: In cell-based assays, HS235 potently and selectively neutralized activins and GDFs implicated in body composition. This translated to complete in vivo target engagement and pharmacodynamic response. In a DIO mouse model, both HS235 and the incretin mimetic significantly improved metabolic parameters and decreased fat mass, but only HS235 increased LBM, while incretin-based treatment led to LBM loss. Importantly, the addition of HS235 to the incretin mimetic lead to a synergistic fat mass loss and prevented loss of LBM. Conclusion: Potent and selective inhibition of activins and GDFs by HS235 represents a novel LBM preserving weight loss strategy orthogonal to incretin mimetics. Collectively, these data support the development of HS235 as a novel anti-obesity agent to complement currently approved incretin-based medications to improve quality of weight loss. Presentation: 6/3/2024

Bufalin induces ferroptosis by modulating the 2,4-dienoyl-CoA reductase (DECR1)-SLC7A11 axis in breast cancer

Breast cancer (BC) is a leading cause of cancer-related mortality worldwide. 2,4-dienoyl-CoA reductase (DECR1), an auxiliary component of beta-oxidation, has been recognized for its role in enhancing lipid peroxidation and inducing ferroptosis in prostate cancer. However, its involvement in breast cancer remains largely unexplored. Our study revealed a notably elevated expression of DECR1 in breast cancer tissues, which correlated with increased malignant characteristics. Importantly, the overexpression of DECR1 significantly enhanced proliferation and migration capabilities in MDA-MB-231 cells. Through a comprehensive high-content screening approach, we identified bufalin and its derivative as potent inhibitors of DECR1 expression. Notably, bufalin demonstrated the highest binding energy during molecular docking studies and was found to promote the degradation of DECR1 via autophagy and ubiquitination. Furthermore, bufalin induced ferroptosis in MDA-MB-231 cells by modulating levels of malondialdehyde (MDA), triglycerides (TG), reactive oxygen species (ROS) and Fe2+ while downregulating the expression of hormone-sensitive lipase (HSL), ferritin heavy chain protein 1 (FPN), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4). These effects were counteracted by DECR1 overexpression. In vivo experiments demonstrated that bufalin inhibited the tumor growth, while decreasing the expression levels of HSL, FPN, SLC7A11, and GPX4, alongside increasing levels of 4-hydroxynonenal (4-HNE). Crucially, the ferroptosis effects induced by bufalin in vivo were also reversed by DECR1 overexpression. Subsequently, we discovered that SLC7A11 interacts with DECR1, inhibition of SLC7A11 led to decreased expression levels of DECR1 along with an accumulation of MDA and Fe2+, effects that were similarly reversed by DECR1 overexpression. Collectively, our findings suggest that targeted therapy against DECR1 combined with further inhibition of its downstream pathway involving SLC7A11/GPX4 may represent a promising strategy for treating breast cancer.

Biofilm morphology and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) on poly-D,L-lactide-co-poly(ethylene glycol) (PDLLA-PEG) coated titanium

Biodegradable polymeric coatings are being explored as a preventive strategy for orthopaedic device-related infection. In this study, titanium surfaces (Ti) were coated with poly-D,L-lactide (PDLLA, (P)), polyethylene-glycol poly-D,L-lactide (PEGylated-PDLLA, (PP20)), or multi-layered PEGylated-PDLLA (M), with or without 1 % silver sulfadiazine. The aim was to evaluate their cytocompatibility, resistance to Staphylococcus aureus biofilm formation, and their potential to enhance the susceptibility of any biofilm formed to antibiotics. Using automated high-content screening confocal microscopy, biofilm formation of a clinical methicillin-resistant Staphylococcus aureus (MRSA) isolate expressing GFP was quantified, along with isogenic mutants that were unable to form polysaccharidic or proteinaceous biofilm matrices. The results showed that PEGylated-PDLLA coatings exhibited significant antibiofilm properties, with M showing the highest effect. This inhibitory effect was stronger in S. aureus biofilms with a matrix composed of proteins compared to those with an exopolysaccharide (PIA) biofilm matrix. Our data suggest that the antibiofilm effect may have been due to (i) inhibition of the initial attachment through microbial surface components recognising adhesive matrix molecules (MSCRAMMs), since PEG reduces protein surface adsorption via surface hydration layer and steric repulsion; and (ii) mechanical disaggregation and dispersal of microcolonies due to the bioresorbable/degradable nature of the polymers, which undergo hydration and hydrolysis over time. The disruption of biofilm morphology by the PDLLA-PEG co-polymers increased S. aureus susceptibility to antibiotics like rifampicin and fusidic acid. Adding 1 % AgSD provided additional early bactericidal effects on both biofilm and planktonic S. aureus. Additionally, the coatings were cytocompatible with immune cells, indicating their potential to enhance bacterial clearance and reduce bacterial colonisation of titanium-based orthopaedic biomaterials.

Prevalence of visual abnormalities detected through paediatric vision screening in Queensland, Australia.

Vision screening programs can provide epidemiological information regarding visual impairment in children. This study aims to report the characteristics of visual abnormalities diagnosed through the Primary School Nurse Health Readiness Program (PSNHRP) in Queensland, Australia. A retrospective review of vision screening records from the PSNHRP between January 2017 and December 2020 was undertaken. Children aged between 4 and 7 who underwent vision screening were included for review. Children with a visual acuity of worse than 6/9-1 using the Parr 4 m letter-matching chart or those who failed the SPOT Vision Screener were referred to an optometrist or ophthalmologist for review. 164 890 children underwent vision screening. 12148 children failed visual screening (7.4%) and were referred for an eye assessment. 6011 (69.4%) of the 8659 children who attended ophthalmic review had a confirmed visual abnormality. Of 164 890 screened children, 1187 (0.72%) were confirmed to have anisometropia, 3843 (2.33%) had refractive error, 194 (0.12%) had strabismus, 755 (0.46%) had anisometropic amblyopia, 136 (0.08%) had strabismic amblyopia, and 1356 (0.82%) had an unspecific abnormality. There was no statistically significant difference in the age at screening between any visual abnormality (p = 0.94). Anisometropia, refractive error, and strabismus were significantly more common in females than males (p = 0.03, p < 0.01, and p = 0.03 respectively), whereas anisometropic amblyopia was more common in males (p < 0.01). We report the prevalence of visual abnormalities detected through the PSNHRP vision screening program. Identification of medical or socioeconomic risk factors that are likely to be associated with visual abnormalities can help to optimise vision screening programs.