Fibrillar Layer Research Articles

Pathogenesis of Fuchs endothelial corneal dystrophy, the fibrillar layer and individualized treatment

Fuchs endothelial corneal dystrophy (FECD) is agenetic and age-associated corneal disease characterized by an accelerated loss of corneal endothelial cells and an increased subendothelial deposition of extracellular matrix (ECM). Clinically, advanced disease leads to corneal edema with subsequent reduction in visual acuity. In the majority of patients with advanced FECD, afibrillar layer (FL) appears on the posterior corneal surface. This FL is mostly localized in the inferotemporal corneal quadrant, marks areas with significantly reduced endothelial cell density and increased corneal thickness in the sense of edema and can be visualized and measured using Scheimpflug backscatter analysis due to increased backscatter. FECD is currently the most common indication for corneal transplantation worldwide, usually in the form of Descemet membrane endothelial keratoplasty (DMEK). New treatment approaches include variations of DMEK surgery such as hemi- or quarter DMEK with individualized and smaller grafts or Descemet membrane stripping only (DSO). In the future, clinical imaging of the FL as aparticularly affected endothelial area could be important for FECD progression assessment and planning of surgical interventions. This article provides an overview of the current state of research on the clinical aspects, pathogenesis, fibrillar layer and individualized treatment of FECD.

Modeling spherulitic and fibrillar crystallization kinetics in injection molding: Analysis of process variables and morphological evolution

Injection molding of polypropylene was conducted using a heating device to control mold surface temperature over time. By varying the temperature and heating times, a significant effect on cavity pressures, temperatures, and morphology distribution in the resulting samples was obtained.The University of Salerno's UNISA code, a simulation model for injection molding, was used to simulate the experimental conditions. This code incorporates a crystallization kinetics model that accounts for the competing formation of spherulites and fibrils from the same amorphous material, considering the effects of temperature, pressure, and flow evolution during different stages of the process.The simulation results showed good agreement with experimental data for temperature evolutions within the mold and pressure variations at critical points during the filling, packing, and cooling stages. Additionally, the simulation consistently predicted the formation of a fibrillar layer near the mold wall. Overall, a comprehensive framework for understanding and simulating the injection molding process is provided, with relevant implications for the optimization of manufacturing conditions and improving part quality.

Observations on the transmission of Dientamoeba fragilis and the cyst life cycle stage.

Little is known about the life cycle and mode of transmission of Dientamoeba fragilis. Recently it was suggested that fecal–oral transmission of cysts may play a role in the transmission of D. fragilis. In order to establish an infection, D. fragilis is required to remain viable when exposed to the pH of the stomach. In this study, we investigated the ability of cultured trophozoites to withstand the extremes of pH. We provide evidence that trophozoites of D. fragilis are vulnerable to highly acidic conditions. We also investigated further the ultrastructure of D. fragilis cysts obtained from mice and rats by transmission electron microscopy. These studies of cysts showed a clear cyst wall surrounding an encysted parasite. The cyst wall was double layered with an outer fibrillar layer and an inner layer enclosing the parasite. Hydrogenosomes, endoplasmic reticulum and nuclei were present in the cysts. Pelta-axostyle structures, costa and axonemes were identifiable and internal flagellar axonemes were present. This study therefore provides additional novel details and knowledge of the ultrastructure of the cyst stage of D. fragilis.

Segmentation of the fibrillar layer in advanced fuchs endothelial corneal dystrophy: Inter‐oberserver‐reliability and intra‐observer‐repeatability analysis of corneal densitometry images

Aims: Our previous studies state that a central subendothelial collagen‐rich fibrillar layer (FL) is present in about 80% of advanced Fuchs endothelial corneal dystrophy (FECD) corneas which correlates with decreased corneal endothelial cell density and focal oedema formation. In this study, we investigated the previously unknown inter‐observer reliability and intra‐observer reproducibility of FL segmentation on Scheimpflug corneal densitometry images in patients with advanced FECD.Methods: Preoperative Scheimpflug images of patients receiving DMEK or triple DMEK for advanced FECD were retrospectively analysed. FL‐negative cases were excluded. Images were manually segmented with the open‐source software MITK by two experienced graders. A MATLAB‐based code calculated the region of interest (ROI) area, maximum calliper length, maximum horizontal and vertical dimension, and Dice similarity coefficient for FL‐areas. The intraclass correlation coefficient (ICC) was calculated by IBM SPSS (two‐way mixed, average measures). The FL localization on corneal densitometry were visualized by spatial heatmaps by MATLAB.Results: Among 308 eyes, 248 were FL‐positive (80.5%) and 60 FL‐negative (19.5%). The average Dice similarity coefficient of FL areas segmented by two graders was calculated at 0.85. Calculations on the segmentations of Grader 1 vs. Grader 2 include: ROI 7.91mm2 ± 4.8 vs. 9.29 mm2 ± 5.0, Calliper length 4.07 mm ± 1.1 vs. 4.21 mm ± 1.0, maximum horizontal dimension 3.85 mm ± 1.1 vs. 3.95 mm ± 1.0, maximum vertical dimension 3.17 mm ± 1.0 vs. 3.3 mm ± 1.0. The ICC was calculated at 0.938 vs. 0.957 vs. 0.930 for ROI (0.955 vs. 0.960 vs. 0.944 calliper length, 0.958 vs. 0.959 vs. 0.946 maximum horizontal dimension, 0.952 vs. 0.941 vs. 0.945 maximum vertical dimension) and 0.85 vs. 0.86 vs. 0.89 for the Dice similarity coefficient (inter‐observer vs. intra‐observer Grader 1 vs. intra‐observer Grader 2). Spatial heatmap analysis demonstrated primarily inferotemporal localization of increased densitometry areas in FL‐positive eyes.Conclusions: FL segmentation on corneal densitometry images exhibit high inter‐observer reliability and intra‐observer reproducibility scores. We provide evidence for corneal densitometry images as a valid tool to detect FL in advanced FECD and confirm the inferotemporal corneal projection of FL.

Architecture of Actinoplanes missouriensis sporangia and zoospores visualized using quick-freeze deep-etch electron microscopy.

The architecture of sporangia and zoospores of Actinoplanes missouriensis was analyzed at a high resolution using quick-freeze deep-etch replica electron microscopy. This analysis revealed that (i) sporangia were surrounded by at least 2 membranous layers with smooth surfaces, (ii) zoospores were enclosed by a fibrillar layer, and (iii) flagella were generated in a restricted area on the zoospore surface.

Ultrastructural features of the body wall of the helminth Heterakis dispar (Schrank, 1790) (Nematoda, Heterakidae)

The structure of the body wall (cuticle, hypoderm, and muscle layer) of the nematode Heterakis dispar (Schrank, 1790) from the family Heterakidae was studied using light and electron microscopy methods and compared with other species of the same family. The cuticle of the adult nematode H. dispar consists of 8 layers: 1 - an outer membrane layer or epicuticle; 2, 3 - outer and inner cortical layers; 4, 5 - outer and inner homogeneous or middle layers; 6, 7 - outer and inner fibrous or fibrillar layers; 8 - basement membrane. The cortical, homogeneous and fibrillary layers constitute 12.4, 45.3 and 42.3% of the all cuticle, respectively. The homogeneous layer of the cuticle in the lateral ridges in both male and female and near the bursa of the male is several times as thick as other parts of the helminth cuticle. Unlike other species of the family, males of H. dispar possess 3 different forms of cuticular structure in different parts of the body. In the basal layer of the cuticle, sustaining structures consisting of dense fibrils and microtubules were found, which were not previously noted in other species of the family. It is likely that they provide strength to the body wall of the helminth. In the hypodermis of the nematode, dorsal, ventral, and 2 lateral ridges are traced, the lateral ridges being twice as large as others. Ultrastructural features of the excretory channels and nerve cords located in the hypodermal ridges, were also revealed. The nervous system of the helminth is orthogonal. The ventral nerve cord is wider than the dorsal one. Muscle layer is of the polymyar type, number of muscle cells arranged in groups varies from 17 to 26, depending on the sex and body part of the helminth.

Modeling and Analysis of Morphology of Injection Molding Polypropylene Parts Induced by In-Mold Annealing

It is generally recognized that high-temperature treatments, namely annealing, influence the microstructure and the morphology, which, in turn, determine the mechanical properties of polymeric parts. Therefore, annealing can be adopted to control the mechanical performance of the molded parts. This work aims to assess the effect of annealing on the morphology developed in isotactic polypropylene (iPP) injection-molded parts. In particular, a two-step annealing is adopted: the polymer is injected in a mold at a high temperature (413 or 433 K), which is kept for 5 min (first annealing step); afterward, the mold temperature is cooled down at 403 K and held at that temperature for a time compatible with the crystallization half-time at that temperature (second annealing step). The characterization of morphology is carried out by optical and electronic scanning microscopy. The temperature of the first annealing step does not influence the thickness of the fibrillar skin layer; however, such a layer is thinner than that found in the molded parts obtained without any annealing steps. The second annealing step does not influence the thickness of the fibrillar skin layer. The dimension of spherulites found in the core is strongly influenced by both annealing steps: the spherulite dimensions enlarge by the effect of annealing steps. A model that considers spherulite and fibril evolutions is adopted to describe the effect of molding conditions on the final morphology distribution along the part thickness. The model, which adopts as input the thermo-mechanical histories calculated by commercial software for injection molding simulation, consistently predicts the main effects of the molding conditions on the morphology distributions.

Morphology of Microinjection Molded iPP Parts in Controlled Conditions

AbstractA part made of just one material (mono‐material) is a new frontier in reducing environmental impact of plastic, being 100% recyclable. The focus of this work is on the possibility of controlling the properties of parts obtained by microinjection molding (μIM). μIM tests in variothermal conditions are conducted on an isotactic polypropylene. Two variothermal steps are adopted: the filling and packing stages are conducted at one selected mold temperature, and subsequent annealing steps are conducted while the sample is still inside the mold. A comparison with the parts produced under constant mold temperature is also performed. Electronic microscopy is adopted for the characterization of morphology. Furthermore, atomic force microscopy coupled with HarmoniX (HMX) tool allows detecting simultaneously local morphology and mechanical properties. The part morphology is characterized by a fibrillar layer close to the sample walls and a spherulitic core; a transition zone is also detectable in between. Morphology significantly influences mechanical properties: the transition zone shows the minimum value of elastic modulus, additionally, the elastic modulus increases with spherulite dimensions. Eventually, the annealing step results to be crucial in determining the part properties and can be adopted as a robust method to tailor properties through the process.

Correlation of Clinical Fibrillar Layer Detection and Corneal Thickness in Advanced Fuchs Endothelial Corneal Dystrophy.

Central subendothelial geographic deposits are formed as a fibrillar layer (FL) in advanced Fuchs endothelial corneal dystrophy (FECD). Previous studies demonstrated a significant decrease in corneal endothelial cell (CEC) density and an increase in focal corneal backscatter in the FL area. The present study investigated the association of the FL with edema formation and its localization. Patients (n = 96) presenting for Descemet membrane endothelial keratoplasty (DMEK) for advanced FECD were included. Slit-lamp biomicroscopy with FECD grading was followed by Scheimpflug imaging with en face backscatter analysis and pachymetric analysis. FL dimensions were measured, and correlation with pachymetric values was performed. An FL was detected in 74% of all eyes (n = 71). Pachymetric values in FL-positive versus FL-negative eyes were for corneal thickness at the apex (ACT) 614 ± 52 µm and 575 ± 46 µm (p = 0.001), for peripheral corneal thickness at 1 mm (PCT1mm) 616 ± 50 µm and 580 ± 44 µm (p = 0.002), for PCT2mm 625 ± 48 µm and 599 ± 41 µm (p = 0.017), for PCT3mm 651 ± 46 µm and 635 ± 40 µm (p = 0.128) and for PCT4mm 695 ± 52 µm and 686 ± 43 µm (p = 0.435), respectively. Correlation analysis indicated a weak correlation for the FL maximum vertical caliper diameter with ACT and PCT1mm values but no further relevant correlations. In FL-positive eyes, increased focal corneal backscatter and increased corneal thickness showed primarily central and inferotemporal localization. In conclusion, Scheimpflug imaging shows an association of the FL with increased corneal thickness in advanced FECD and shows localization of the FL and increased corneal thickness in the central and inferotemporal region. This may provide important information for progression assessment and therapeutic decision making in FECD patients in the future.

Morphology predictions in molded parts: a multiphysics approach

Injection molding of polymer parts at a micro-scale is successfully applied in the fabrication of electronics and biomedical devices where high geometrical accuracy is required. Microinjection molding is more challenging than conventional injection molding due to the necessity to account for the presence of air in the cavity, which slows down the process, and a strong flow field that may induce premature solidification of semi-crystalline polymers. The process modeling and simulation are crucial steps toward predicting all the final parts' properties. For this reason, a multiphysics approach was used to model microinjection molding under different mold cycle temperatures. A well-characterized polypropylene was selected for this purpose. A model for tracking the polymer-air interface during the filling was adopted to account for air's effect in the micro-cavity. Additionally, a model accounting for the effect of crystallization on viscosity was implemented. Models describing the evolution of morphology into fibrils were previously proposed in steady-state conditions. In this work, a model for describing the crystallization into fibrils was proposed and adapted for the first time to the transient conditions of microinjection molding. The aim was the prediction of the final morphology developed during the process. The morphology evolution toward fibrillar structure is consistent with those observed experimentally; in particular, the fibrillar layer thickness decreased with the increase of the mold temperature.

Polarization‐Sensitive Photodetectors Based on Directionally Oriented Organic Bulk‐Heterojunctions

AbstractPolarized spectroscopic photodetection enables numerous applications in diverse areas such as sensing, industrial quality control, and visible light communications. Although organic photodetectors (OPDs) can offer a cost‐effective alternative to silicon‐based technology—particularly when flexibility and large‐area arrays are desired—polarized OPDs are only beginning to receive due research interest. Instead of resorting to external polarization optics, this report presents polarized OPDs based on directionally oriented blends of poly(3‐hexylthiophene) (P3HT) and benchmark polymer or nonfullerene acceptors fabricated using a versatile solution‐based method. Furthermore, a novel postprocessing scheme based on backfilling and plasma etching is advanced to ameliorate high dark‐currents that are otherwise inherent to fibrillar active layers. The resulting polarized P3HT:N2200 OPDs exhibit a broad enhancement across all principal figures of merit compared to reference isotropic devices, including peak responsivities of 70 mA W−1 and up to a threefold increase in 3 dB bandwidth to 0.75 MHz under parallel‐polarized illumination. Polarization ratios of up to 3.5 are obtained across a spectral range that is determined by the specific donor–acceptor combinations. Finally, as a proof‐of‐concept demonstration, polarized OPDs are used for photoelasticity analysis of rubber films under tensile deformation, highlighting their potential for existing and emerging applications in advanced optical sensing.

Melt electro-written scaffolds with box-architecture support orthogonally oriented collagen

Melt electro-writing (MEW) is a state-of-the-art technique that supports fabrication of 3D, precisely controlled and reproducible fiber structures. A standard MEW scaffold design is a box-structure, where a repeat layer of 90° boxes is produced from a single fiber. In 3D form (i.e. multiple layers), this structure has the potential to mimic orthogonal arrangements of collagen, as observed in the corneal stroma. In this study, we determined the response of human primary corneal stromal cells and their deposited fibrillar collagen (detected using a CNA35 probe) following six weeks in vitro culture on these box-structures made from poly(ϵ-caprolactone) (PCL). Comparison was also made to glass substrates (topography-free) and electrospun PCL fibers (aligned topography). Cell orientation and collagen deposition were non-uniform on glass substrates. Electrospun scaffolds supported an excellent parallel arrangement of cells and deposited collagen to the underlying architecture of aligned fibers, but there was no evidence of bidirectional collagen. In contrast, MEW scaffolds encouraged the formation of a dense, interconnected cellular network and deposited fibrillar collagen layers with a distinct orthogonal-arrangement. Collagen fibrils were particularly dominant through the middle layers of the MEW scaffolds’ total thickness and closer examination revealed these fibrils to be concentrated within the pores’ central regions. With the demand for donor corneas far exceeding the supply—leaving many with visual impairment—the application of MEW as a potential technique to recreate the corneal stroma with spontaneous, bidirectional collagen organization warrants further study.

Metabolomics-driven Approaches on Interactions Between Enterococcus faecalis and Candida albicans Biofilms

This study aimed to determine the effect of Enterococcus faecalis on the cell growth and hyphal formation of Candida albicans and to understand the exact mechanism of candidal inhibition by the existence of E. faecalis by metabolomic analysis. Single- and dual-species biofilms of E. faecalis and C. albicans were formed in a microtiter plate, and the metabolomic profiles of both biofilms was determined by gas chromatography-mass spectrometry. The hyphal cell growth of C. albicans after treatment with both the supernatant and biofilm cells of E. faecalis was examined microscopically. The expression levels of Efg1 and the images of C. albicans cell wall in single- and dual-species biofilms were determined by real-time quantitative polymerase chain reaction and transmission electron microscopy, respectively. The violacein levels produced by Chromobacterium violaceum were measured to determine the quorum sensing (QS) inhibitory activity of single- and dual-species biofilms. The biofilm cell growth, Efg1 expression, and hyphal development of C. albicans were inhibited by E. faecalis. Compared to single-species biofilms, alterations in carbohydrate, amino acid, and polyamine metabolites were observed in the dual-species biofilm for both microorganisms. Putrescine and pipecolic acid were detected at high levels in dual-species biofilm. A thicker β-glucan chitin and a denser and narrower fibrillar mannan layer of C. albicans cell wall were observed in dual-species biofilm. QS inhibitory activity was higher in dual-species biofilm suspensions of E. faecalis and C. albicans than in their single-species biofilms. E. faecalis inhibited the hyphal development and biofilm formation of C. albicans. Biofilm suspensions of C. albicans and E. faecalis showed an anti-QS activity, which increased even further in the environment where the two species coexisted. Investigation of putrescine and pipecolic acid can be an important step to understand the inhibition of C. albicans by bacteria.

Heating‐induced aggregation control for efficient sequential‐cast organic solar cells

AbstractThe aggregation and morphology within the photoactive layer is of considerable significance to boost the power‐conversion efficiency (PCE) of organic solar cells (OSCs). Herein, heating‐induced aggregation control of nonfullerene acceptor BTP‐eC7 during sequential casting was demonstrated. The large aggregates of BTP‐eC7 can be significantly reduced by sequential casting of BTP‐eC7 hot solution on the D18 fibrillar layer, and further eliminated by sequential casting of BTP‐eC7 hot solution on the D18 fibrillar layer heated on hot substrate, leading to stronger face‐on π–π stacking and appropriate phase separation within the photoactive layer to promote exciton dissociation and charge transfer. The maximum PCE of D18/BTP‐eC7 solar cells can be enhanced from 8.1% of room temperature casting to 15.9% of hot solution, hot‐substrate casting, therefore demonstrates that heating‐induced aggregation and sequential‐casting strategies are a promising approach in improving the performance of OSCs employing nonfullerene acceptors with limited solubility or strong crystallization ability.

Prediction of morphology development within micro–injection molding samples

The understanding of the mechanisms that determines mechanical performances during micro-injection molding is crucial to meet the increasing demand for advanced plastic products with improved durability and performance. These depend on the morphology developed during the process, which, on its turn, is determined by the complex thermomechanical history experienced by polymer chains. Thus, the ability to correctly predict morphology opens the possibility to forecast final part properties. Semi-crystalline polymers parts show a morphology mainly composed of spherulites in the core and fibrils close to the sample walls. In this work, a commercial software for injection molding simulation was adopted for describing the thermomechanical history experienced by polymer chains during micro–injection molding tests, whereas a crystallization model was introduced for the description of the two morphologies mentioned above. The molecular stretch parameter was adopted as the main variable for describing the effect of flow on the molecular arrangement. A threshold mechanism based on the molecular stretch was also introduced in the crystallization model for controlling the growth of fibrillar morphologies. Different micro-injection molding tests were conducted in an end-less cavity with the aim of testing the capability of the model in predicting the morphology developed along the sample thickness. The proposed model was able to predict the formation of fibrils in the regions close to the sample wall, furthermore, the reduction of fibrillar layer thickness with the mold temperature increase was consistently described.

Quick-Freeze, Deep-Etch Electron Microscopy Reveals the Characteristic Architecture of the Fission Yeast Spore.

The spore of the fission yeast Schizosaccharomyces pombe is a dormant cell that is resistant to a variety of environmental stresses. The S. pombe spore is coated by a proteinaceous surface layer, termed the Isp3 layer because it comprises mainly Isp3 protein. Although thin-section electron microscopy and scanning electron microscopy have revealed the fundamental structure of the spore, its architecture remains unclear. Here we visualized S. pombe spores by using a quick-freeze replica electron microscopy (QFDE-EM) at nanometer resolution, which revealed novel characteristic structures. QFDE-EM revealed that the Isp3 layer exists as an interwoven fibrillar layer. On the spore cell membrane, many deep invaginations, which are longer than those on the vegetative cell membrane, are aligned in parallel. We also observed that during spore germination, the cell surface changes from a smooth to a dendritic filamentous structure, the latter being characteristic of vegetative cells. These findings provide significant insight into not only the structural composition of the spore, but also the mechanism underlying the stress response of the cell.

Scalar nanostructure of the Candida albicans cell wall; a molecular, cellular and ultrastructural analysis and interpretation

Despite the importance of fungal cell walls as the principle determinant of fungal morphology and the defining element determining fungal interactions with other cells, few scalar models have been developed that reconcile chemical and microscopic attributes of its structure. The cell wall of the fungal pathogen Candida albicans is comprised of an amorphous inner skeletal layer of β(1,3)- and β(1,6)-glucan and chitin and an outer fibrillar layer thought to be dominated by highly mannosylated cell wall proteins. The architecture of these two layers can be resolved at the electron microscopy level, but the visualised structure of the wall has not yet been defined precisely in chemical terms. We have therefore examined the precise structure, location and molecular sizes of the cell wall components using transmission electron microscopy and tomography and tested predictions of the cell wall models using mutants and agents that perturb the normal cell wall structure. We demonstrate that the fibrils are comprised of a frond of N-linked outer chain mannans linked to a basal layer of GPI-proteins concentrated in the mid-wall region and that the non-elastic chitin microfibrils are cantilevered with sufficient lengths of non-fibrillar chitin and/or β-glucan to enable the chitin-glucan cage to flex, e.g. during morphogenesis and osmotic swelling. We present the first three-dimensional nano-scalar model of the C. albicans cell wall which can be used to test hypotheses relating to the structure–function relationships that underpin the pathobiology of this fungal pathogen.

Role of structural stiffness on the loading capacity of fibrillar adhesive composite

Bio-inspired fibrillar adhesives have been extensively studied for applications in a wide range of fields, including transfer printing, intelligent robotics, and space technology. Herein, by considering a generalized adhesive composite composed of a fibrillar adhesive layer and a backing layer in contact with a smooth substrate, we developed a theoretical approach based on the peel zone model to predict its loading and failure behavior. The effects of mechanical and geometrical properties were discussed and verified with finite element method simulations. We found that the loading capacity is dominated by the effective adhesion strength and the stretched area of the adhesive micropillars (peel zone) with a simple linear relationship. Specifically, the peel zone is determined by the ratio of the bending stiffness of the backing layer to the tensile stiffness of the micropillar structures. Moreover, a design map for desired loading capacity with optimized structural stiffness is proposed. These findings present a comprehensive understanding of the loading mechanism of fibrillar adhesives and provide new insights into the rational design of reversible strong adhesion for related technologies.

Fibrillar Layer as a Marker for Areas of Pronounced Corneal Endothelial Cell Loss in Advanced Fuchs Endothelial Corneal Dystrophy

We sought to assess the correlation of corneal endothelial cell (CEC) density to alterations of collagen composition of Descemet membrane (DM) in advanced Fuchs endothelial corneal dystrophy (FECD) and to image such changes by slit-lamp biomicroscopy invivo. Prospective, observational consecutive case series. Fifty eyes (50 subjects) with advanced FECD were enrolled. After slit-lamp biomicroscopy and corneal Scheimpflug imaging, the Descemet endothelium complex (DEC) was retrieved during DM endothelial keratoplasty (DMEK) surgery. The expression of collagens I, III, and IV (COL I, COL III, and COL IV) and corresponding CEC density were analyzed by immunofluorescence flat mount-staining. Presence, diameter and surface area of collagen expression, and CEC density served as the main outcome measures. Immunofluorescence staining revealed central coherent collagen positive areas (mean surface area= 10mm2 ± 6mm2) corresponding to a fibrillar layer burying the guttae of DM in 84% (42/50) of DECs. CEC density overlying the fibrillar layer compared with the periphery was significantly reduced (-54.8%, P< .0001) with a steep decline of CEC density at its borders. Subgroup analysis revealed that the fibrillar layer may be imaged by slit-lamp biomicroscopy invivo with significant positive correlation of mean maximum diameter detected by slit-lamp biomicroscopy (dSL max= 4.1mm ± 0.9mm) and by immunofluorescence staining (dIF max= 4.7mm ± 1.1mm; r= 0.76; P= .001). A fibrillar layer with a clear geographic pattern marks areas of pronounced loss of CEC density in advanced FECD eyes and may be imaged by slit-lamp biomicroscopy invivo.

Caspofungin Induced Cell Wall Changes of Candida Species Influences Macrophage Interactions.

Candida species are known to differ in their ability to cause infection and have been shown to display varied susceptibilities to antifungal drugs. Treatment with the echinocandin, caspofungin, leads to compensatory alterations in the fungal cell wall. This study was performed to compare the structure and composition of the cell walls of different Candida species alone and in response to caspofungin treatment, and to evaluate how changes at the fungal cell surface affects interactions with macrophages. We demonstrated that the length of the outer fibrillar layer varied between Candida species and that, in most cases, reduced fibril length correlated with increased exposure of β-1,3-glucan on the cell surface. Candida glabrata and Candida guilliermondii, which had naturally more β-1,3-glucan exposed on the cell surface, were phagocytosed significantly more efficiently by J774 macrophages. Treatment with caspofungin resulted in increased exposure of chitin and β-1,3-glucan on the surface of the majority of Candida species isolates that were tested, with the exception of C. glabrata and Candida parapsilosis isolates. This increase in exposure of the inner cell wall polysaccharides, in most cases, correlated with reduced uptake by macrophages and in turn, a decrease in production of TNFα. Here we show that differences in the exposure of cell wall carbohydrates and variations in the repertoire of covalently attached surface proteins of different Candida species contributes to their recognition by immune cells.