Cell Topography Research Articles

Sub-cone visual resolution by active, adaptive sampling in the human foveola.

The foveated architecture of the human retina and the eye's mobility enables prime spatial vision, yet the interplay between photoreceptor cell topography and the constant motion of the eye during fixation remains unexplored. With in vivo foveal cone-resolved imaging and simultaneous microscopic photo stimulation, we examined visual acuity in both eyes of 16 participants while precisely recording the stimulus path on the retina. We find that resolution thresholds were correlated with the individual retina's sampling capacity, and exceeded what static sampling limits would predict by 18%, on average. The length and direction of fixational drift motion, previously thought to be primarily random, played a key role in achieving this sub-cone diameter resolution. The oculomotor system finely adjusts drift behavior towards retinal areas with higher cone densities within only a few hundred milliseconds to enhance retinal sampling.

Sub-cone visual resolution by active, adaptive sampling in the human foveola

The foveated architecture of the human retina and the eye’s mobility enables prime spatial vision, yet the interplay between photoreceptor cell topography and the constant motion of the eye during fixation remains unexplored. With in vivo foveal cone-resolved imaging and simultaneous microscopic photo stimulation, we examined visual acuity in both eyes of 16 participants while precisely recording the stimulus path on the retina. We find that resolution thresholds were correlated with the individual retina’s sampling capacity, and exceeded what static sampling limits would predict by 18%, on average. The length and direction of fixational drift motion, previously thought to be primarily random, played a key role in achieving this sub-cone diameter resolution. The oculomotor system finely adjusts drift behavior towards retinal areas with higher cone densities within only a few hundred milliseconds to enhance retinal sampling.

Machine learning and artificial intelligence: Enabling the clinical translation of atomic force microscopy-based biomarkers for cancer diagnosis

The influence of biomechanics on cell function has become increasingly defined over recent years. Biomechanical changes are known to affect oncogenesis; however, these effects are not yet fully understood. Atomic force microscopy (AFM) is the gold standard method for measuring tissue mechanics on the micro- or nano-scale. Due to its complexity, however, AFM has yet to become integrated in routine clinical diagnosis. Artificial intelligence (AI) and machine learning (ML) have the potential to make AFM more accessible, principally through automation of analysis. In this review, AFM and its use for the assessment of cell and tissue mechanics in cancer is described. Research relating to the application of artificial intelligence and machine learning in the analysis of AFM topography and force spectroscopy of cancer tissue and cells are reviewed. The application of machine learning and artificial intelligence to AFM has the potential to enable the widespread use of nanoscale morphologic and biomechanical features as diagnostic and prognostic biomarkers in cancer treatment.

Directed Differentiation of Adipose-Derived Stem Cells Using Imprinted Cell-Like Topographies as a Growth Factor-Free Approach.

The influence of surface topography on stem cell behavior and differentiation has garnered significant attention in regenerative medicine and tissue engineering. The cell-imprinting method has been introduced as a promising approach to mimic the geometry and topography of cells. The cell-imprinted substrates are designed to replicate the topographies and dimensions of target cells, enabling tailored interactions that promote the differentiation of stem cells towards desired specialized cell types. In fact, by replicating the size and shape of cells, biomimetic substrates provide physical cues that profoundly impact stem cell differentiation. These cues play a pivotal role in directing cell morphology, cytoskeletal organization, and gene expression, ultimately influencing lineage commitment. The biomimetic substrates' ability to emulate the native cellular microenvironment supports the creation of platforms capable of steering stem cell fate with high precision. This review discusses the role of mechanical factors that impact stem cell fate. It also provides an overview of the design and fabrication principles of cell-imprinted substrates. Furthermore, the paper delves into the use of cell-imprinted polydimethylsiloxane (PDMS) substrates to direct adipose-derived stem cells (ADSCs) differentiation into a variety of specialized cells for tissue engineering and regenerative medicine applications. Additionally, the review discusses the limitations of cell-imprinted PDMS substrates and highlights the efforts made to overcome these limitations.

Spatial Immunophenotyping from Whole-Slide Multiplexed Tissue Imaging Using Convolutional Neural Networks.

The multiplexed immunofluorescence (mIF) platform enables biomarker discovery through the simultaneous detection of multiple markers on a single tissue slide, offering detailed insights into intratumor heterogeneity and the tumor-immune microenvironment at spatially resolved single cell resolution. However, current mIF image analyses are labor-intensive, requiring specialized pathology expertise which limits their scalability and clinical application. To address this challenge, we developed CellGate, a deep-learning (DL) computational pipeline that provides streamlined, end-to-end whole-slide mIF image analysis including nuclei detection, cell segmentation, cell classification, and combined immuno-phenotyping across stacked images. The model was trained on over 750,000 single cell images from 34 melanomas in a retrospective cohort of patients using whole tissue sections stained for CD3, CD8, CD68, CK-SOX10, PD-1, PD-L1, and FOXP3 with manual gating and extensive pathology review. When tested on new whole mIF slides, the model demonstrated high precision-recall AUC. Further validation on whole-slide mIF images of 9 primary melanomas from an independent cohort confirmed that CellGate can reproduce expert pathology analysis with high accuracy. We show that spatial immuno-phenotyping results using CellGate provide deep insights into the immune cell topography and differences in T cell functional states and interactions with tumor cells in patients with distinct histopathology and clinical characteristics. This pipeline offers a fully automated and parallelizable computing process with substantially improved consistency for cell type classification across images, potentially enabling high throughput whole-slide mIF tissue image analysis for large-scale clinical and research applications.

Investigation of antigen-presenting cells in the intestinal mesentery in normal and adhesive processes

The morphology and topography of dendritic cells in the mesentery of the small intestine, their quantity, and their presence under normal conditions and during progressive adhesive processes have been insufficiently studied, presenting an important issue in immunomorphology. This study aimed to identify and determine the functional activity of antigen-presenting cells using lectin histochemistry with peanut and lentil lectins under normal conditions and during adhesive processes. The methods employed included morphometric analysis, lectin histochemistry, and statistical analysis. For the first time, using lectin histochemistry with lentil and soy lectins, functionally active and immunologically immature antigen-presenting cells were found in the structure of lymphoid clusters of the small intestine mesentery. A correlation was established between the progression of adhesion processes and the number of antigen-presenting cells. Correlation between dendritic cells and the quantity of immunologically immature lymphocytes and B-lymphocytes was identified, enhancing the understanding of the functional mechanisms of the local arm of innate immunity. An increasing trend in immunologically immature lymphocytes and B-lymphocytes was observed alongside an increase in antigen presenting cells. The results indicated that the activation of dendritic cells in mesenteric tissues induced an increase in immunologically immature lymphocytes, from which B-lymphocytes subsequently developed, initiating a local immune response. The increased frequency of PNA+- and LCA+- antigen-presenting cells pointed to an elevated immune reactivity of lymphoid clusters. This study on the distribution of antigen-presenting cells contributes to a deeper understanding of the structure of lymphoid tissue associated with serous membranes, as well as fat-associated lymphoid aggregates, and underscores the connection between innate and adaptive immunity in the abdominal cavity

Immune cell topography of head and neck cancer

BackgroundApproximately 50% of head and neck squamous cell carcinomas (HNSCC) recur after treatment with curative intent. Immune checkpoint inhibitors are treatment options for recurrent/metastatic HNSCC; however, less than 20% of...

Microscopic methods to study meat and meat product quality

Reliable information about meat quality at all stages of the production process is necessary to ensure high quality of meat products. The structure of muscle, connective and fat tissues plays a direct role in formation of meat quality. Microscopic methods allow investigating the meat structure and determining its change depending on a range of endo- and exogenous factors (animal species, breed, sex, conditions of raising and slaughter) and on a type of technological processing. The paper presents the main directions of using microscopic analysis in investigation of meat and finished meat products. An advantage of microscopy is presentation of results in a visual form as well as a possibility of performing morphometry, including with the use of computer systems of image analysis, and obtaining quantitative characteristics of structures. Most common are light microscopy and electron microscopy. Due to various staining procedures, light microscopy enables detecting different components of a sample, studying topography and morphology of tissues and cells. Electron microscopy gives information about the ultrastructure of cells and their chemical composition. The paper discusses possibilities of microscopy in assessment of composition and detection of falsification of finished meat products. It has been noted that the use of several approaches and methods of staining allows reliable identification of many components, including components of plant origin. Histological methods can ensure detection of falsification and control of meat product composition at the state level.

Investigating the Effectiveness of Ceragenins against Acinetobacter baumannii to Develop New Antimicrobial and Anti-Adhesive Strategies.

A growing body of experimental data indicates that ceragenins (CSAs), which mimic the physicochemical properties of the host's cationic antimicrobial peptide, hold promise for the development of a new group of broad-spectrum antimicrobials. Here, using a set of in vivo experiments, we assessed the potential of ceragenins in the eradication of an important etiological agent of nosocomial infections, Acinetobacter baumannii. Assessment of the bactericidal effect of ceragenins CSA-13, CSA-44, and CSA-131 on clinical isolates of A. baumannii (n = 65) and their effectiveness against bacterial cells embedded in the biofilm matrix after biofilm growth on abiotic surfaces showed a strong bactericidal effect of the tested molecules regardless of bacterial growth pattern. AFM assessment of bacterial cell topography, bacterial cell stiffness, and adhesion showed significant membrane breakdown and rheological changes, indicating the ability of ceragenins to target surface structures of A. baumannii cells. In the cell culture of A549 lung epithelial cells, ceragenin CSA-13 had the ability to inhibit bacterial adhesion to host cells, suggesting that it interferes with the mechanism of bacterial cell invasion. These findings highlight the potential of ceragenins as therapeutic agents in the development of antimicrobial strategies against bacterial infections caused by A. baumannii.

Retinal ganglion cell topography and spatial resolving power in the pajama cardinalfish Sphaeramia nematoptera (Bleeker, 1856).

We studied the topography of retinal ganglion cells (GCs) and estimated spatial resolving power (SRP) in the pajama cardinalfish Sphaeramia nematoptera (Bleeker, 1856), a relatively small brightly colored fish inhabiting coral reefs and lagoons in the Western Pacific. S. nematoptera is an active night predator feeding on near-bottom animal plankton and benthos. DAPI staining was used to label nuclei of GCs and non-GCs in the inner plexiform and ganglion cell layers. Non-GCs were distinguished from GCs in Nissl-stained retinal wholemounts based on cell size, shape, and staining intensity. The proportion of displaced amacrine cells (DACs) varied from 15.46 ± 1.12 (visual streak [VS]) to 17.99 ± 1.06% (dorsal periphery) (mean ± S.E.M., N = 5); the respective proportions of glial cells were 6.61 ± 0.84 and 5.89 ± 0.76%. Thus, 76%-78% of cells in the ganglion cell layer and inner plexiform layer were GCs. The minimum spatial coverage of GCs (3600-4600 cells/mm2) was detected in the dorsal and ventral periphery. It gradually increased toward the central retina to form a moderate VS. The maximum GC density (11,400-12,400 cells/mm2) was registered in the central portion of the VS. No pronounced concentric retinal specializations were found. The total number of GCs ranged within 595.2-635.9 × 103. The anatomical spatial resolving power was minimum in the ventral periphery (4.91-5.53 cpd) and maximum in the central portion of the VS (8.47-9.07 cpd). The respective minimum separable angles were 0.18-0.20° and 0.11-0.12°. The relatively high spatial resolving power and presence of the VS in the pajama cardinalfish are in line with its highly visual behavior.

Topography of Retinal Ganglion Cells of a Northern Goshawk Accipiter gentilis

Topography of Retinal Ganglion Cells of a Northern Goshawk Accipiter gentilis

Scanning Ion-Conductance Microscopy for Studying β-Amyloid Aggregate Formation on Living Cell Surfaces.

β-Amyloid aggregation on living cell surfaces is described as responsible for the neurotoxicity associated with different neurodegenerative diseases. It is suggested that the aggregation of β-amyloid (Aβ) peptide on neuronal cell surface leads to various deviations of its vital function due to myriad pathways defined by internalization of calcium ions, apoptosis promotion, reduction of membrane potential, synaptic activity loss, etc. These are associated with structural reorganizations and pathologies of the cell cytoskeleton mainly involving actin filaments and microtubules and consequently alterations of cell mechanical properties. The effect of amyloid oligomers on cells' Young's modulus has been observed in a variety of studies. However, the precise connection between the formation of amyloid aggregates on cell membranes and their effects on the local mechanical properties of living cells is still unresolved. In this work, we have used correlative scanning ion-conductance microscopy (SICM) to study cell topography, Young's modulus mapping, and confocal imaging of Aβ aggregate formation on living cell surfaces. However, it is well-known that the cytoskeleton state is highly connected to the intracellular level of reactive oxygen species (ROS). The effect of Aβ leads to the induction of oxidative stress, actin polymerization, and stress fiber formation. We measured the reactive oxygen species levels inside single cells using platinum nanoelectrodes to demonstrate the connection of ROS and Young's modulus of cells. SICM can be successfully applied to studying the cytotoxicity mechanisms of Aβ aggregates on living cell surfaces.

Silica Replicas Derived from Mammalian Cells as an Innovative Approach to Physically Direct Cell Lineage Decisions of Mesenchymal Stem Cells.

By means of a "live-cell" template strategy, silica replicas displaying the same morphology and topography of the mammalian cells used as templates are fabricated. The replicas are used as substrates to direct the differentiation of mesenchymal stem cells (MSCs) to predefined cell lineages. Upregulation of specific genes shows how the silica replica-based substrates have the ability to induce the molecular characteristics of the mature cell types from which they have been derived from. Thus, MSCs cultured in the presence of silica replicas of human osteoblasts (HObs) differentiate into HObs-like cells, as shown by the upregulation of specific osteogenic genes. Likewise, when MSCs are incubated with silica replicas derived from human chondrocytes, an enhanced expression of chondrogenic markers is observed. Importantly, the effects of the silica replicas are cell type-specific since the incubation of MSCs with HObs silica replicas does not result in upregulation of chondrogenic markers and vice versa. What is more, for both cases, the differentiation rate is enhanced when the silica replicas are used in combination with growth factors, suggesting a potential synergistic effect. These results demonstrate the potential of this innovative method as an efficient and cheap approach with the potential to eliminate, or at least reduce, the use of biochemically soluble compounds in stem cells research.

Characterisation of superficial corneocyte properties over category I pressure ulcers: Insights into topographical and maturation changes

BackgroundPressure ulcers (PUs) are chronic wounds that are detrimental to the quality of life of patients. Despite advances in monitoring skin changes, the structure and function of skin cells over the site of pressure ulcers are not fully understood. ObjectiveThe present study aims to evaluate local changes in the properties of superficial corneocytes in category 1 PU sites sampled from a cohort of hospitalised patients. MethodsCells were collected from a PU-compromised site and an adjacent control area and their topographical, maturation and mechanical properties were analysed. ResultsCorneocytes at the PU-compromised site were characterised by higher levels of immature cornified envelopes (p < 0.001) and greater amounts of desmoglein-1 (corneodesmosomal protein) (p < 0.001) compared to the adjacent control area. The cells at the control site presented the typical ridges-and-valleys topographical features of sacrum corneocytes. By contrast, the PU cells presented circular nano-objects at the cell surface, and, for some patients, the cell topography was deformed. CEs at the PU site were also smaller than at the control site. Although differences were not observed in the mechanical properties of the cells, those of the elderly patients were much softer compared with young subjects. ConclusionThis is the first study investigating the changes in corneocyte properties in category I pressure ulcers. Superficial cells at the PU sites showed altered topographical and maturation characteristics. Further studies are required to elucidate if these changes are a consequence of early loss of skin integrity or a result of mechanical and microclimate insults to the skin surface.

Magnetic manipulation of Fe3O4@BaTiO3 nanochains to regulate extracellular topographical and electrical cues.

Magnetic fields play an essential role in material science and biomedical engineering. Magnetic-responsive materials can be arranged orderly in matrix to realize the construction of an aligned scaffold under magnetic induction. However, a single topological cue is insufficient to activate neural tissue regeneration, demanding more cues to promote regeneration synergistically, such as electrical stimulation and a biomimetic matrix. Herein, we propose one-dimensional (1D) magnetoelectric Fe3O4@BaTiO3 nanochains with controllable lengths under the regulation of a magnetic field. These nanochains can be oriented in the biomimetic hydrogel under magnetic guidance and induce the hydrogel microfiber to align along the direction of the nanochains, which is beneficial for cell-oriented outgrowth. This aligned hydrogel enabled wireless electrical stimulation mediated by magnetoelectric nanochains under magnetic stimulation, thereby activating the voltage-gated ion channel. Consequently, topological and electrical cues in this multifunctional biomimetic hydrogel synergistically enhanced the expression of neural functional proteins, facilitating synapse remodeling and neural regeneration. Predictably, the construction of multifunctional hydrogels based on low-cost and facile synthesis of magnetoelectric nanochains is an emerging patient-friendly and effective therapeutic strategy for neural or other tissue regeneration. STATEMENT OF SIGNIFICANCE: A facile and controllable magnetic strategy is established to manipulate 1D nanomaterial growth, matrix topography, and wireless electrical stimulation of cells. First, the magnetic-assisted interface co-assembly was used to control the length of Fe3O4@BaTiO3 nanochains with enhanced magnetoelectric effect. Then, the motion of the magnetic-induced nanochains guided the orientation of nanofibers in a 3D biomimetic hydrogel matrix. Finally, wireless electrical signals and topological cues in the biomimetic matrix synergistically promoted orderly aligned cell outgrowth and membrane depolarization by Ca2+ influx, thus enhancing nerve cell synaptic plasticity and functional expression. Consequently, this work provides a conceptual strategy from material design to extracellular matrix signal manipulation and synergistic induction of tissue regeneration.

Nanomechanical changes in probiotic bacteria under antibiotics exposure: Implications on Lactobacillus biofilm formation

Recognition of the microbial cell's surface constituents' biophysical properties is an important research topic, allowing a better understanding of the cell's behaviour under different conditions. Atomic force microscopy (AFM) was employed in this study to analyse the basis of the nanomechanical changes in probiotic bacteria under nitrofurantoin, furazolidone, and nitrofurazone exposure. Recorded significant changes in the two Lactobacillus strains cells morphology, topography, and adhesion parameters resulted in the increase of the cells' longitude (up to 2.58 μm), profile height (by around 0.50 μm), and decrease in the adhesion force (up to 13.58 nN). Young's modulus and adhesion energy decreased within 96 h, however with no negative effect on the cells' morphology or loss of structural integrity. Observed modifications present the mode of action of the 5-nitrofuran derivative antibiotics on probiotic biofilm formation and suggest activation of the multilevel adaptation mechanisms to counteract unfavorable environments. A visual change in bacterial morphology such as an increased surface-to-volume ratio might be a link between molecular-level events and outcomes in individual cells and biofilms. This paper for the first time shows, that these antibiotics affect the properties of non-target microorganisms as lactobacilli, and might impair biofilm formation. However, the degree of such transformations depends on the delivered active substance.

Investigation of the Antifungal and Anticancer Effects of the Novel Synthesized Thiazolidinedione by Ion-Conductance Microscopy

In connection with the emergence of new pathogenic strains of Candida, the search for more effective antifungal drugs becomes a challenge. Part of the preclinical trials of such drugs can be carried out using the innovative ion-conductance microscopy (ICM) method, whose unique characteristics make it possible to study the biophysical characteristics of biological objects with high accuracy and low invasiveness. We conducted a study of a novel synthesized thiazolidinedione’s antimicrobial (for Candida spp.) and anticancer properties (on samples of the human prostate cell line PC3), and its drug toxicity (on a sample of the human kidney cell line HEK293). We used a scanning ion-conductance microscope (SICM) to obtain the topography and mechanical properties of cells and an amperometric method using Pt-nanoelectrodes to register reactive oxygen species (ROS) expression. All data and results are obtained and presented for the first time.

PD-1 Overexpression in Sézary Syndrome Is Epigenetically Regulated

PD-1 Overexpression in Sézary Syndrome Is Epigenetically Regulated

Role of Morphology in the Diagnosis of Acute Leukemias: Systematic Review

AbstractThe role of hematopathologists in the diagnosis of acute leukemia (AL) starts with the morphological examination of either peripheral blood smear or bone marrow. The morphological hallmark for the myeloblast includes “Auer rods” and “Phi bodies.” The addition of cytochemical stains such as myeloperoxidase, Sudan Black B, periodic acid-Schiff stain, nonspecific esterase, and Perls' stain acts as an important adjunct to the morphological classification in the resource-constrained settings. The recent World Health Organization classification still endorses the utility of morphology which requires the presence of either ≥ 20% lymphoblasts or myeloblasts/or its equivalents (monoblasts, promonocytes, or megakaryoblasts) and integrates it with the clinical features, immunophenotyping (IP), and molecular genetics for making the diagnosis of AL. Morphology can give clue to the specific diagnosis of acute myeloid leukemia (AML) with t(8:21), t(15:17), t(16:16), or inv(16) and this diagnosis can be made irrespective of blasts count if such translocations are demonstrated by molecular tests. There are some interesting findings such as blasts with “hand-mirror” morphology, nuclear cleavage, prominent cytoplasmic vacuoles, pseudo-Chediak-Higashi granules, cup-like nucleus, and other dysplastic features helping in differentiating lymphoid and myeloid leukemias. Transient abnormal myelopoiesis in Down syndrome and hypoplastic AL can be picked up on morphological examination. Bone marrow biopsy would be greatly beneficial and complementary to aspirate smears and is required for diagnosing exact cellularity, topography of cells, dyspoiesis, myelonecrosis, gelatinous marrow transformation, myelofibrosis, and IP can be performed using immunohistochemistry. Morphological examination in AL is not only helpful for diagnosis but also useful for predicting the prognosis in posttherapy cases, AML with myelodysplasia-related changes, therapy-related myeloid neoplasms, and mixed phenotype AL. Hematogones, blastoid mantle cell lymphoma, high grade B cell lymphoid with blastoid morphology, Burkitt leukemia, prolymphocytes in prolymphocytic leukemia, hairy cell leukemia variant, plasmablasts especially in plasmablastic leukemia, or plasma cell leukemia can mimic AL and IP is useful in these situations. Hence, morphology should be considered as a kind of “gold-standard” starting point for the analysis of AL cases. Morphological examination cannot be replaced and advanced tests cannot be used as surrogate for morphology.

Artificial Neural Network-Aided Computational Approach for Mechanophenotyping of Biological Cells Using Atomic Force Microscopy.

The artificial neural network (ANN) based models have shown the potential to provide alternate data-driven solutions in disease diagnostics, cell sorting and overcoming AFM-related limitations. Hertzian model-based prediction of mechanical properties of biological cells, although most widely used, has shown to have limited potential in determining constitutive parameters of cells of uneven shape and nonlinear nature of force-indentation curves in AFM-based cell nano-indentation. We report a new artificial neural network-aided approach, which takes into account, the variation in cell shapes and their effect on the predictions in cell mechanophenotyping. We have developed an artificial neural network (ANN) model which could predict the mechanical properties of biological cells by utilizing the force versus indentation curve of AFM. For cells with 1 μm contact length (platelets), we obtained a recall of 0.97 ± 0.03 and 0.99 ± 0.0 for cells with hyperelastic and linear elastic constitutive properties respectively with a prediction error of less than 10%. Also, for cells with 6-8 μm contact length (red blood cells), we obtained the recall of 0.975 in predicting mechanical properties with less than 15% error. We envisage that the developed technique can be used for better estimation of cells' constitutive parameters by incorporating cell topography into account.