Blue Autofluorescence Research Articles

Retinal Patterns and the Role of Autofluorescence in Choroideremia

Background: Choroideremia is a monogenic inherited retinal dystrophy that manifests in males with night blindness, progressive loss of peripheral vision, and ultimately profound sight loss, commonly by middle age. It is caused by genetic defects of the CHM gene, which result in a deficiency in Rab-escort protein-1, a key element for intracellular trafficking of vesicles, including those carrying melanin. As choroideremia primarily affects the retinal pigment epithelium, fundus autofluorescence, which focuses on the fluorescent properties of pigments within the retina, is an established imaging modality used for the assessment and monitoring of affected patients. Methods and Results: In this manuscript, we demonstrate the use of both short-wavelength blue and near-infrared autofluorescence and how these imaging modalities reveal distinct disease patterns in choroideremia. In addition, we show how these structural measurements relate to retinal functional measures, namely microperimetry, and discuss the potential role of these retinal imaging modalities in clinical practice and research studies. Moreover, we discuss the mechanisms underlying retinal autofluorescence patterns by imaging with a particular focus on melanin pigment. Conclusions: This could be of particular significance given the current progress in therapeutic options, including gene replacement therapy.

Longitudinal Structural and Functional Evaluation of Dark-without-Pressure Fundus Lesions in Patients with Autoimmune Diseases.

The main objective of this study was to report and investigate the characteristics and longitudinal changes in dark-without-pressure (DWP) fundus lesions in patients with autoimmune diseases using multimodal imaging techniques. In this retrospective observational case series, five patients affected by ocular and systemic autoimmune disorders and DWP were examined. DWP was assessed by multimodal imaging, including color fundus photography (CFP), near-infrared reflectance (NIR), blue reflectance (BR), blue autofluorescence (BAF), optical coherence tomography (OCT), OCT-angiography (OCT-A), fluorescein angiography (FA) and indocyanine green angiography (ICGA), and functional testing, including standard automated perimetry (SAP) and electroretinography (ERG). Follow-up examinations were performed for four out of five patients (range: 6 months-7 years). DWP fundus lesions were found in the retinal mid-periphery and were characterized by the hypo-reflectivity of the ellipsoid zone on OCT. DWP appeared hypo-reflective in NIR, BR and BAF, and exhibited hypo-fluorescence in FA in two patients while showing no signs in one patient. ICGA showed hypo-fluorescent margins in one patient. SAP and ERG testing did not show alterations attributable to the DWP lesion. Follow-up examinations documented rapid dimensional changes in DWP even in the short term (1 month). This study suggests a possible association between autoimmune diseases and DWP. New FA and ICGA features were described. The proposed pathogenesis hypotheses may operate as a basis for further investigation of a lesion that is still largely unknown. Large population studies would be necessary to confirm whether there is a higher incidence of DWP in this patient category.

Extensive macular atrophy with pseudodrusen-like appearance: comprehensive review of the literature.

This review focuses on extensive macular atrophy with pseudodrusen-like appearance (EMAP), a recently described maculopathy presenting with pseudodrusen-like lesions and chorioretinal atrophy more pronounced in the vertical axis. Narrative review of the literature published until May 2024. The early onset age of EMAP (50-55 years) and its distinctive natural history, which includes night blindness followed by severe vision loss, differentiate it from atrophic age-related macular degeneration (AMD). A clear pathogenesis has not been determined, but risk factors include female gender and complement system abnormalities (altered levels of C3 and CH50). Moreover, lifelong exposure to pesticides has been suggested as risk factor for direct neuronal degeneration involving rods and cones. In the early phase of the disease, reticular pseudodrusen-like lesions appear in the superior perifovea and tend to coalescence horizontally into a flat, continuous, reflective material localized between the retinal pigmented epithelium and Bruch's membrane. Over time, EMAP causes profound RPE and outer retinal atrophy in the macular area, with a recent classification reporting a 3-stages evolution pattern. Blue autofluorescence showed rapidly evolving atrophy with either hyperautofluorescent or isoautofluorescent borders. Significant similarities between the diffuse-trickling phenotype of geographic atrophy and EMAP have been reported. Macular neovascularization is a possible complication. EMAP is specific form of early-onset atrophic macular degeneration with rapid evolution and no treatment. Further studies are needed to assess the best management.

Interreader and Intermodality Variability in Macular Atrophy Quantification in Neovascular Age-related Macular Degeneration: Comparison of 6 Imaging Modalities

Macular atrophy is a common complication in neovascular age-related macular degeneration (AMD) and is associated with poorer visual outcomes. This study evaluated interreader and intermodality variability in measuring macular atrophy in previously treated neovascular AMD eyes without exudation using 6 imaging modalities. Prospective, cohort study. Thirty participants with previously treated neovascular AMD showing no signs of exudation at the time of enrollment and exhibiting macular atrophy. During the same clinic visit, patients were imaged using 6 different imaging modalities: color fundus photography (CFP; Clarus, Carl Zeiss Meditec), near-infrared imaging (NIR; Spectralis, Heidelberg Engineering), structural OCT (Spectralis, Heidelberg Engineering), green fundus autofluorescence (GAF; Clarus, Carl Zeiss Meditec), blue fundus autofluorescence (BAF; Spectralis, Heidelberg Engineering), and pseudocolor imaging (MultiColor; Spectralis, Heidelberg Engineering). Two readers independently measured the macular atrophy area. Interreader and intermodality agreement. The 95% coefficient of repeatability was 5.98 mm2 for CFP, 4.46 mm2 for MultiColor, 3.90 mm2 for BAF, 3.92 mm2 for GAF, 4.86 mm2 for NIR, and 3.55 mm2 for OCT. Similarly, the coefficient of variation was lowest for OCT-based grading at 0.08 and highest for NIR-based grading at 0.28. Accordingly, the intraclass correlation coefficient was 0.742 for CFP, 0.805 for MultiColor, 0.857 for BAF, 0.850 for GAF, 0.755 for NIR, and 0.917 for OCT. The 6 different imaging modalities presented measurements with different mean values, with only a limited number of comparisons not significantly different between the instruments, although measurements were correlated. The largest size of macular atrophy was measured with structural OCT-based grading (median= 4.65 mm2; interquartile range [IQR]= 4.78 mm2) and the smallest was with CFP-based grading (median= 3.86 mm2; IQR= 5.06 mm2). Inconsistencies arose from various factors. In patients with neovascular AMD, macular atrophy measurements vary significantly depending on the imaging technique used. Color fundus photography-based assessments yielded the smallest macular atrophy sizes, whereas structural OCT-based assessments produced the largest. These discrepancies stem from both the inherent limitations of each modality in assessing retinal pigment epithelial atrophy and factors related to neovascularization, such as the coexistence of fibrosis. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Retro Mode Imaging for Detection and Quantification of Sub-RPE Drusen and Subretinal Drusenoid Deposits in Age-Related Macular Degeneration.

Background: Drusen and drusenoid deposits are a hallmark of age-related macular degeneration (AMD). Nowadays, a multimodal retinal imaging approach enables the detection of these deposits. However, quantitative data on subretinal drusenoid deposits (SDDs) are still missing. Here, we compare the capability of en-face drusen and SDD area detection in eyes with non-exudative AMD using conventional imaging modalities versus Retro mode imaging. We also quantitatively assess the topographic distribution of drusen and SDDs. Methods: In total, 120 eyes of 90 subjects (mean age ± standard deviation = 74.6 ± 8.6 years) were included. Coherent en-face drusen and SDD areas were measured via near-infrared reflectance, green (G-) and blue (B-) fundus autofluorescence (AF), and Retro mode imaging. Drusen phenotypes were classified by correlating en-face drusen areas using structural high-resolution spectral domain optical coherence tomography. The topographic distribution of drusen was analyzed according to a modified ETDRS (Early Treatment of Diabetic Retinopathy Study) grid. Intraclass correlation coefficient (ICC) analysis was applied to determine the inter-reader agreement in the SDD en-face area assessment. Results: The largest coherent en-face drusen area was found using Retro mode imaging with a mean area of 105.2 ± 45.9 mm2 (deviated left mode (DL)) and 105.4 ± 45.5 mm2 (deviated right mode (DR)). The smallest en-face drusen areas were determined by GAF (50.9 ± 42.6 mm2) and BAF imaging (49.1 ± 42.9 mm2) (p < 0.001). The inter-reader agreement for SDD en-face areas ranged from 0.93 (DR) to 0.70 (BAF). The topographic analysis revealed the highest number of SDDs in the superior peripheral retina, whereas sub-retinal pigment epithelium drusen were mostly found in the perifoveal retina. Retro mode imaging further enabled the detection of the earliest SDD stages. Conclusions: Retro mode imaging allows for a detailed detection of drusen phenotypes. While hundreds/thousands of SDDs can be present in one eye, the impact of SDD number or volume on AMD progression still needs to be evaluated. However, this new imaging modality can add important knowledge on drusen development and the pathophysiology of AMD.

Comparison of Blue-Light Autofluorescence and Ultrawidefield Green-Light Autofluorescence for Assessing Geographic Atrophy

The goal of this study was to evaluate and compare the intermodality and interreader agreement of manual and semiautomated geographic atrophy (GA) area measurements in eyes with GA due to age-related macular degeneration (AMD) using conventional blue-light fundus autofluorescence (FAF) and ultrawidefield (UWF) green-light FAF systems. Prospective Cohort Study. Seventy-two eyes of 50 patients with a diagnosis of advanced nonneovascular AMD with GA. Fundus autofluorescence images of eyes with GA were obtained during a single visit using both the Spectralis HRA+ OCT2 device and the Optos California device. The area of the GA lesion(s) was segmented and quantified (mm2) with a fully manual approach where the lesions were outlined using Optos Advance and Heidelberg Eye Explorer (HEYEX) software. In addition, for the Heidelberg blue FAF images, GA lesions were also measured using the instrument's semiautomated software (Region Finder 2.6.4). For comparison between modalities/grading method, the mean values of the 2 graders were used. Intraclass correlation coefficients were computed to judge the agreement between graders. Seventy-two eyes of 50 patients were included in this study. There was nearly perfect agreement between graders for the measurement of GA area for all 3 modalities (intraclass correlation coefficient: 0.996 for manual Optos Advance, 0.996 for manual Heidelberg HEYEX, and 0.995 for Heidelberg Region Finder). The measurement of GA area was strongly correlated between modalities, with Spearman correlation coefficients of 0.985 (P < 0.001) between manual Heidelberg and manual Optos, 0.991 (P < 0.001) for Region Finder versus manual Heidelberg, and 0.985 (P < 0.001) for Region Finder versus manual Optos. The absolute mean area differences between the Heidelberg manual versus Region Finder, manual Optos versus Region Finder, and manual Optos versus manual Heidelberg were 1.61 mm2 (P < 0.001), 0.90 mm2 (P < 0.006), and 0.71 mm2 (P<0.001), respectively. We observed excellent interreader agreement for measurement of GA using either 30-degree blue-light FAF or UWF green-light FAF, establishing the reliability of UWF imaging for macular GA assessment. Although the absolute measurements between devices were strongly correlated, they differed significantly, highlighting the importance of using the same device for a given patient for the duration of a study. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Influence of Vitreous Cortex Remnants on Normal Retinal Anatomy in Eyes with Primary Rhegmatogenous Retinal Detachment

To investigate the influence of vitreous cortex remnants (VCRs) removal on normal retinal anatomy in eyes with rhegmatogenous retinal detachment (RRD). Prospective cohort study. Patients with primary RRD operated with pars plana vitrectomy (PPV). Blue fundus autofluorescence and spectral-domain optical coherence tomography were obtained pre-operatively, and at 1 and 6 months after operation. Primary outcomes: rate of retinal displacement and outer retinal folds at 1 month after operation. continuity of the external limiting membrane (ELM) and ellipsoid zone (EZ), and the logarithm of the minimum angle of resolution best-corrected visual acuity (logMAR BCVA) at 6 months after operation. One hundred three eyes were included. Intra-operatively, peripheral (p)VCRs were found in 42 eyes (40.8%) and successfully peeled off from ≥ 2 quadrants in 37 eyes. Macular (m)VCRs were detected in 37 (35.9%) and successfully peeled off in 29 eyes. At the end of operation 44.7% and 55.3% of the eyes were tamponaded with 20% sulfur hexafluoride gas and silicone oil 1000 centistokes, respectively. The only variable significantly associated with displacement was the use of gas tamponade vs. silicone oil (p=0.001) whereas no significant association was found between retinal displacement and pVCRs (p=0.58) or number of quadrants from which pVCRs were peeled off (p=0.39). At 1 month post-operatively ORFs were globally detected in 24 eyes (23.3%). Regression analysis showed a direct correlation between ORFs and the intraoperative detection of mVCRs (p=0.02) and an indirect correlation between ORFs and mVCRs peeling (p= 0.004). Macular VCRs peeling did not influence the continuity of ELM and EZ at the 6- month follow-up (FU). Intraoperative absence of mVCRs (p=0.0016) and peeling of mVCRs (p=0.003) were associated with logMAR BCVA ≤ 0.3 at the 6-month FU. Peeling of pVCRs did not seem to influence the rate of retinal displacement while peeling of mVCRs was associated with a reduced risk of developing ORFs without detrimental effect on the continuity of ELM/EZ at 6 month FU. The patients without mVCRs detected intraoperatively or who underwent mVCRs peeling during operation, showed a significantly better VA at the 6-month FU.

Diverse material properties and morphology of moth proboscises relates to the feeding habits of some macromoth and other lepidopteran lineages.

Insects have evolved unique structures that host a diversity of material and mechanical properties, and the mouthparts (proboscis) of butterflies and moths (Lepidoptera) are no exception. Here, we examined proboscis morphology and material properties from several previously unstudied moth lineages to determine if they relate to flower visiting and non-flower visiting feeding habits. Scanning electron microscopy and three-dimensional imaging were used to study proboscis morphology and assess surface roughness patterns on the galeal surface, respectively. Confocal laser scanning microscopy was used to study patterns of cuticular autofluorescence, which was quantified with colour analysis software. We found that moth proboscises display similar autofluorescent signals and morphological patterns in relation to feeding habits to those previously described for flower and non-flower visiting butterflies. The distal region of proboscises of non-flower visitors is brush-like for augmented capillarity and exhibited blue autofluorescence, indicating the possible presence of resilin and increased flexibility. Flower visitors have smoother proboscises and show red autofluorescence, an indicator of high sclerotization, which is adaptive for floral tube entry. We propose the lepidopteran proboscis as a model structure for understanding how insects have evolved a suite of morphological and material adaptations to overcome the challenges of acquiring fluids from diverse sources.

Torpedo Maculopathy: Case Series of an Underdiagnosed and Rare Condition Using Multimodal Imaging.

Background: Torpedo maculopathy is a rare benign congenital anomaly of the retinal pigment epithelium (RPE) mostly asymptomatic throughout life. The clinical presentation is very typical displaying an ovoid cleft of the RPE typically located in the temporal zone of the macula. Despite this pathognomonic feature, patients are often referred to retina clinics for secondary opinions. The aim of this case series is to raise awareness of this rare condition among ophthalmologists and to explore the added value of multimodal imaging, in particular OCT angiography (OCTA), to increase its identification. History and Signs: 5 patients between 11 and 73 years-old were referred in our institution for further evaluation of an unilateral yellowish hypopigmented torpedo-shaped flat lesion in the temporal sector of the macula. Lesions varied in size and distance from the fovea. 3 patients were asymptomatic and 2 patients complained of decreased vision. Of these two, only one had a decrease in visual acuity in the affected eye as measured at the consultation. Therapy and Outcome: Spectral domain OCT (SD-OCT) revealed in all cases a thinned RPE combined with hyper-reflectivity of the adjacent choroid on the ovoid lesion while the foveal region remained normal. Infrared Reflectance showed a heterogeneous hyperreflective area deliminated with a hyporeflective ring. On fundus blue light autofluorescence (FAF) exam, the lesions appeared hypoautofluorescent with a hyperautofluorescent perimeter. In all cases, OCTA of torpedo lesions identified choriocapillary remodeling with different phenotypes reflecting a possible disappearance of the choriocapillary layer with window effect. The superficial and deep capillary plexus layers (SCP and DCP) were in most cases comparable to the adjacent retina, and no differences were found in the quantitative analysis of SCP and DCP vascular density measured in each eye. Conclusion: Torpedo maculopathy is a rare well described clinical condition that displays pathognomonic features on regular fundoscopy examination. Our case series showed that the use of multimodal imaging, including SD-OCT, FAF and OCTA, seems to be of little value in increasing its recognition thus confirming the importance of its typical clinical appearance among ophthalmologists. Interestingly, SD-OCT and OCTA demonstrated no abnormalities of the adjacent macula of the affected eye, which seems to confirm its isolated local unilateral ophthalmic condition.

Abstract 7163: Pharmacokinetics assessment of intranasal NEO100 treatment on blood-brain barrier disruption and brain penetration of drugs in rodent brain

Abstract Background: Insufficient drug concentrations reaching the brain-localized tumor tissue remains one of the major challenges in the treatment of glioblastoma (GBM). An intranasal (IN) formulation of NEO100 (NeOnc Technologies, Inc., Los Angeles), a highly purified version of perillyl alcohol, has been recently reported to enhance drug concentrations in the brain upon IN co-delivery. Here, we report detailed pharmacokinetics (PK) and tissue analysis to quantitatively examine the extent of increase in drug concentrations in the brain after IN NEO100 administration. Furthermore, we also confirmed that IN NEO100 increases brain drug concentration by circumventing the blood brain barrier. Method: For PK analysis, either IN or oral formulation of a three-drug cocktail (ZEI, consisting of ZN-c3, everolimus, and infigratinib) was used to evaluate the impact of 3% IN NEO100 on the brain penetration profile of the three individual drugs. Athymic mice were grouped into four cohorts to receive 1) oral ZEI; 2) IN ZEI; 3) oral ZEI with IN NEO100; and 4) IN ZEI with IN NEO100. At 2, 4 and 6 hours post ZEI dosing, drug levels in plasma and brain tissue were measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). For BBB disruption study, athymic mice were treated with IN delivery of saline (negative control) or 3% NEO100 one hour post intravenous Evans blue (2%) administration. Tumor bearing mice with disrupted BBB served as positive control. Two hours post Evans blue administration, animals were perfused, and brains were collected and sectioned for confocal microscopy to image Evan’s blue autofluorescence. Results: PK analysis revealed that brain-to-plasma ratios (Kp) for ZN-c3, everolimus, and infigratinib remained nearly equal, independent of the route of administration, i.e. 0.11, 0.03, and 0.82 vs 0.09, 0.03, and 0.87, for IN vs oral routes, respectively. Administration of the ZEI together with IN NEO100, either through oral or IN routes, resulted in higher drug concentrations, both in the plasma and in the brain. However, while overall drug exposure was increased, Kp values of the drugs were not changed. Confocal imaging of brains from mice treated with 3% IN NEO100 did not show presence of Evans blue autofluorescence while positive control mice with disrupted BBB within the tumor core displayed high Evans blue fluorescence. Conclusions: Co-administration of IN NEO100 with ZN-c3, everolimus, and infigratinib increases their brain and plasma exposure. As a result, no significant increase in brain-to-plasma partition was registered for any of the three drugs tested in this study. IN NEO100-mediated increase in brain drug concentration was independent of BBB disruption Citation Format: Anil Thaghalli Shivanna, Tigran Margaryan, Mariya Stavnichuk, William Knight, Sonam Patel, Elaine Cabrales, An-Chi Tien, Thomas Chen, Nader Sanai, Artak Tovmasyan, Shwetal Mehta. Pharmacokinetics assessment of intranasal NEO100 treatment on blood-brain barrier disruption and brain penetration of drugs in rodent brain [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7163.

Adaptive Optics Retinal Imaging in RDH12-Associated Early Onset Severe Retinal Dystrophy.

RDH12 is among the most common genes found in individuals with early-onset severe retinal (EOSRD). Adaptive optics scanning light ophthalmoscopy (AOSLO) enables resolution of individual rod and cone photoreceptors in the retina. This study presents the first AOSLO imaging of individuals with RDH12-associated EOSRD. Case series of patients who attended Moorfields Eye Hospital (London, UK). Spectral-domain optical coherence tomography, near-infrared reflectance (NIR), and blue autofluorescence imaging were analyzed. En face image sequences of photoreceptors were recorded using either of two AOSLO modalities. Cross-sectional analysis was undertaken for seven patients and longitudinal analysis for one patient. Nine eyes from eight patients are presented in this case series. The mean age at the time of the assessment was 11.2 ± 6.5years of age (range 7-29). A subfoveal continuous ellipsoid zone (EZ) line was present in eight eyes. Posterior pole AOSLO revealed patches of cone mosaics. Average cone densities at regions of interest 0.5° to the fovea ranged from 12,620 to 23,660 cells/mm2, whereas intercell spacing ranged from 7.0 to 9.7µm. This study demonstrates that AOSLO can provide useful high-quality images in patients with EOSRD, even during childhood, with nystagmus, and early macular atrophy. Cones at the posterior pole can appear as scattered islands or, possibly later in life, as a single subfoveal conglomerate. Detailed image analysis suggests that retinal pigment epithelial stress and dysfunction may be the initial step toward degeneration, with NIR being a useful tool to assess retinal well-being in RDH12-associated EOSRD.

Aβ-Aggregation-Generated Blue Autofluorescence Illuminates Senile Plaques as well as Complex Blood and Vascular Pathologies in Alzheimer's Disease.

Senile plaque blue autofluorescence was discovered around 40 years ago, however, its impact on Alzheimer's disease (AD) pathology has not been fully examined. We analyzed senile plaques with immunohistochemistry and fluorescence imaging on AD brain sections and also Aβ aggregation in vitro. In DAPI or Hoechst staining, the nuclear blue fluorescence could only be correctly assigned after subtracting the blue plaque autofluorescence. The flower-like structures wrapping dense-core blue fluorescence formed by cathepsin D staining could not be considered central-nucleated neurons with defective lysosomes since there was no nuclear staining in the plaque core when the blue autofluorescence was subtracted. Both Aβ self-oligomers and Aβ/hemoglobin heterocomplexes generated blue autofluorescence. The Aβ amyloid blue autofluorescence not only labels senile plaques but also illustrates red cell aggregation, hemolysis, cerebral amyloid angiopathy, vascular plaques, vascular adhesions, and microaneurysms. In summary, we conclude that Aβ-aggregation-generated blue autofluorescence is an excellent multi-amyloidosis marker in Alzheimer's disease.

Choroidal neovascularization as first sign of Best's vitelliform dystrophy in a child

Aims/Purpose: To report a case of choroidal neovascularization secondary to Best's vitelliform dystrophy in a child managed by intravitreal aflibercept.Methods: Interventional, case report.Results: A 9‐year‐old boy reported decreased visual acuity (VA) with metamorphopsia in his right eye (RE) for the previous month. VA was RE 20/100 and left eye (LE) 20/20. Funduscopy revealed right‐eye macular oedema with deep macular haemorrhage associated to a bilateral orange‐yellowish deposit. Optical coherence tomography (OCT) showed sub‐ and intraretinal fluid in the foveal area along with a hyperreflective subretinal deposit and a localized retinal pigment epithelium (RPE) elevation. Blue autofluorescence (BAF) imaging disclosed a central hyper autofluorescence area as well as a larger defect corresponding to the haemorrhage and the subretinal deposit. The LE was positive for a central deposit located under the RPE with hyper autofluorescence at BAF. Familiar history was unknown for ocular conditions and the clinical history was irrelevant for fever, inflammation, adenopathy, articular, neurological or respiratory conditions. The condition was diagnosed as choroidal neovascularization (CNV) secondary to Best's vitelliform dystrophy and a single intravitreal injection of aflibercept was performed under general anaesthesia. Genetic study revealed a likely pathogenic mutation c.874G&gt;C (p.Glu292Gln) in the BEST1 gene (missense change, not previously published) affecting a functional dominion. The subretinal bleeding and fluid resolved after one single injection of aflibercept and VA improved to 20/20. No recurrences have been observed during the subsequent five years in either eye.Conclusions: We report a case of CNV as first manifestation of a previously not reported mutation of Best's vitelliform dystrophy in a 9‐year‐old boy that was successfully treated with one single intravitreal injection of aflibercept.

Computational Prediction of Coiled-Coil Protein Gelation Dynamics and Structure.

Protein hydrogels represent an important and growing biomaterial for a multitude of applications, including diagnostics and drug delivery. We have previously explored the ability to engineer the thermoresponsive supramolecular assembly of coiled-coil proteins into hydrogels with varying gelation properties, where we have defined important parameters in the coiled-coil hydrogel design. Using Rosetta energy scores and Poisson-Boltzmann electrostatic energies, we iterate a computational design strategy to predict the gelation of coiled-coil proteins while simultaneously exploring five new coiled-coil protein hydrogel sequences. Provided this library, we explore the impact of in silico energies on structure and gelation kinetics, where we also reveal a range of blue autofluorescence that enables hydrogel disassembly and recovery. As a result of this library, we identify the new coiled-coil hydrogel sequence, Q5, capable of gelation within 24 h at 4 °C, a more than 2-fold increase over that of our previous iteration Q2. The fast gelation time of Q5 enables the assessment of structural transition in real time using small-angle X-ray scattering (SAXS) that is correlated to coarse-grained and atomistic molecular dynamics simulations revealing the supramolecular assembling behavior of coiled-coils toward nanofiber assembly and gelation. This work represents the first system of hydrogels with predictable self-assembly, autofluorescent capability, and a molecular model of coiled-coil fiber formation.

Saliva as a Biomarker in Oral Cancer

The prognosis for patients with oral cancer remains poor in spite of advances in therapy of many other malignancies. Early diagnosis and treatment remains the key to improved patient survival. The tumor markers are playing an increasingly important role in cancer detection and management. These laboratory-based tests are potentially useful in screening for early malignancy, aiding in cancer diagnosis, determining prognosis, surveillance following curative surgery for cancer, up-front predicting drug response or resistance, and monitoring therapy in advanced disease. Diagnostic tests for early detection include brush biopsy, toluidine blue staining, autofluorescence, salivary proteomics, DNA analysis, biomarkers and spectroscopy. This article focuses on biomarkers as valuable utility in risk assessment, clinical screening, diagnosis, and prognosis prediction of oral cancer in the era of precision medicine.

Review on imaging methods in non-infectious posterior uveitis, principles, relevance, and practical clinical applications to disease entities

The work-up and diagnosis of posterior uveitis rely heavily on multiple imaging methods that have become available beyond the mere photographic imaging and fluorescein angiography (FA) used to image uveitis in the past. Global assessment and precise follow-up of posterior uveitis were achieved with the development of indocyanine green angiography (ICGA) since the mid-1990ties that, together with FA, made it possible to perform dual FA and ICGA giving information on both the retina and the choroidal compartment. Further non-invasive imaging methods were developed subsequently that contributed to additional valuable information completing the dual FA/ICGA basic appraisal of uveitis, including (1) optical coherence tomography (OCT) giving a quasi-histological morphology of retinal structures of the posterior pole, (2) enhanced-depth imaging OCT (EDI-OCT) allowing to image the choroidal compartment and (3) blue light fundus autofluorescence (BAF) showing the integrity or damage of the retinal pigment epithelium, the photoreceptors and the outer retina. OCT-angiography (OCT-A) became available more recently and presented the advantage to image the retinal and choroidal circulations without needing dye injections, necessary for dual FA/ICGA. This review article will illustrate the principles, relevance and practical applications of these different imaging methods used in uveitis by examining the main categories of non-infectious posterior uveitis entities including (1) retinal inflammatory disorders, inflammatory diseases of the outer retina and of the choriocapillaris (choriocapillaritis) and stromal choroiditis.

Effects of the dipeptides comprising leucine and lysine on lifespan and age-related stress in Caenorhabditis elegans.

The aging process is affected by various stressors. An increase in oxidative stress is related to the impairment of physiological functions and enhancement of glycative stress. Food-derived bioactive peptides have various physiological functions, including antioxidant activities. Dipeptides comprising Leu and Lys (LK and KL, respectively) have been isolated from foods; however, their physiological properties remain unclear. In this study, we investigated the antioxidant/antiglycation activity of dipeptides and their antiaging effects using Caenorhabditis elegans (C.elegans). Both dipeptides showed antioxidant activities against several reactive oxygen species (ROS) in vitro. In particular, the scavenging activity of LK against superoxide radicals was higher than KL did. Moreover, dipeptides suppressed advanced glycation end products (AGEs) formation in the BSA-glucose model. In the lifespan assays using wild-type C.elegans, both LK and KL significantly prolonged the mean lifespan by 20.9% and 11.7%, respectively. In addition, LK decreased intracellular ROS and superoxide radical levels in C.elegans. Blue autofluorescence, an indicator of glycation in C.elegans with age, was also suppressed by LK. These results suggest that dipeptides, notably LK, show an antiaging effect by suppressing oxidative and glycative stress. Our findings suggest that such dipeptides can be used as a novel functional food ingredient. Food-derived dipeptide Leu-Lys (LK) and Lys-Leu (KL) exert antioxidant and antiglycation activity in vitro. Treatment with LK prolonged the mean lifespan and maximum lifespan of C.elegans more than that of KL. Intracellular ROS and blue autofluorescence levels (indicator of aging) were suppressed by LK.

Optical Coherence Tomography Angiography (OCT-A) in Uveitis: A Literature Review and a Reassessment of Its Real Role.

The global and precise follow-up of uveitis has become possible with the availability of dual fluorescein (FA) and indocyanine green angiography (ICGA) since the mid-1990s. Progressively, additional non-invasive imaging methods have emerged, bringing value-added precision to the imaging appraisal of uveitis, including, among others, optical coherence tomography (OCT), enhanced-depth imaging OCT (EDI-OCT) and blue light fundus autofluorescence (BAF). More recently, another complementary imaging method, OCT-angiography (OCT-A), further allowed retinal and choroidal circulation to be imaged without the need for dye injection. The purpose of this review was aimed at examining the evidence in published reports indicating whether OCT-A could possibly replace dye angiographic methods, as well as the real practical impact of OCT-A. A literature search in the PubMed database was performed using the terms OCT-angiography and uveitis, OCTA and uveitis and OCT-A and uveitis. Case reports were excluded. Articles were classified into technical reports, research reports and reviews. Articles in the two latter categories were analyzed in a more detailed, individual fashion. Special attention was paid to whether there were arguments in favor of an exclusive rather than complementary use of OCT-A. Furthermore, a synthesis of the main practical applications of OCT-A in the management of uveitis was attempted. Between 2016 (the year of the first articles) and 2022, 144 articles containing the search terms were identified. After excluding case report articles, 114 articles were retained: 4 in 2016, 17 in 2017, 14 in 2018, 21 in 2019, 14 in 2020, 18 in 2021 and 26 in 2022. Seven articles contained technical information or consensus-based terminology. Ninety-two articles could be considered as clinical research articles. Of those, only two hinted in their conclusions that OCT-A could hypothetically replace dye methods. The terms mostly used to qualify the contribution of the articles in this group were "complementary to dye methods", "adjunct", "supplementing" and other similar terms. Fifteen articles were reviews, none of which hinted that OCT-A could replace dye methods. The situations where OCT-A represented a significant practical contribution to the practical appraisal of uveitis were identified. To date, no evidence was found in the literature that OCT-A can replace the classic dye methods; however, it can complement them. Promoting the possibility that non-invasive OCT-A can substitute the invasive dye methods is deleterious, giving the elusive impression that dye methods are no longer inevitable for evaluating uveitis patients. Nevertheless, OCT-A is a precious tool in uveitis research.

Bracelet salt glands of the recretohalophyte Limonium bicolor: Distribution, morphology, and induction.

Halophytes complete their life cycles in saline environments. The recretohalophyte Limonium bicolor has evolved a specialized salt secretory structure, the salt gland, which excretes Na+ to avoid salt damage. Typical L. bicolor salt glands consist of 16 cells with four fluorescent foci and four secretory pores. Here, we describe a special type of salt gland at the base of the L. bicolor leaf petiole named bracelet salt glands due to their beaded-bracelet-like shape of blue auto-fluorescence. Bracelet salt glands contain more than 16 cells and more than four secretory pores. Leaf disc secretion measurements and non-invasive micro-test techniques indicated that bracelet salt glands secrete more salt than normal salt glands, which helps maintain low Na+ levels at the leaf blade to protect the leaf. Cytokinin treatment induced bracelet salt gland differentiation, and the developed ones showed no further differentiation when traced with a living fluorescence microscopy imager, even though new salt gland development and leaf expansion were observed. Transcriptome revealed a NAC transcription factor gene that participates in bracelet salt gland development, as confirmed by its genome editing and overexpression in L. bicolor. These findings shed light on bracelet salt gland development and may facilitate the engineering of salt-tolerant crops.

Double Concentric Hyperautofluorescent Ring in EYS-Associated Retinitis Pigmentosa.

A 37-year-old Caucasian female with consanguineous parents and a brother with nonsyndromic retinitis pigmentosa (nsRP) presented with longstanding nyctalopia. The best-corrected visual acuity was 20/20 in both eyes. Anterior segment examination and fundoscopy were unremarkable. Blue light fundus autofluorescence (FAF) revealed a bilateral and symmetrical double concentric hyperautofluorescent ring (Fig. 1). On spectral domain optical coherence tomography, the retinal structure was preserved inside the inner ring, whereas outer retinal atrophy was observed outside its limits. Genetic testing identified the c.5928-2A>G p.? pathogenic variant in homozygosity in EYS gene.FIGURE 1: Double concentric hyperautofluorescent ring in EYS-associated retinitis pigmentosa. Right (A) and left (B) FAF highlights 2 hyperautofluorescent rings, an inner perifoveal ring and an outer ring, located along the vascular arcades and demarcating a diffuse hyperautofluorescent annular surface area. FAF indicates fundus autofluorescence.Whereas a perifoveal/perimacular ring of hyperautofluores-cence is a common FAF finding across several RP genotypes,1 the presence of a double concentric hyperautofluorescent ring was deemed pathognomonic of NR2E3-associated autosomal-dominant RP.2 We describe for the first time the occurrence of this peculiar FAF phenotype in EYS-associated nsRP, highlighting that FAF alone does not seem to be a reliable method of distinguishing between RP genotypes.