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Meibomian Glands (MG) are sebaceous glands responsible for the production of meibum, the main component of the Tear Film Lipid Layer (TFLL). The TFLL facilitates the spread of the tear film over the ocular surface, provides stability and reduces tear evaporation. Alterations in meibum composition lead to different ocular alterations like Meibomian Gland Dysfunction (MGD) and subsequent Evaporative Dry Eye (EDE). The aim of the present study was to investigate the composition and abundance of meibum lipids and their relationship with eyelid margin abnormalities, lipid layer patterns and MG status. The study utilizes a lipidomic approach to identify and quantify lipids in meibum samples using an Elute UHPLC system. This system considered all four dimensions (mass/charge, retention time, ion mobility and intensity) to provide the accurate identification of lipid species. Samples were categorized as healthy or low/no signs of alteration (group 1) or severe signs of alteration or EDE/MGD (group 2). The current investigation found differences in Variable Importance in Projection lipid abundance between both groups for the MGD signs studied. Changes in meibum composition occur and are related to higher scores in eyelid margin hyperaemia, eyelid margin irregularity, MG orifice plugging, MG loss and lipid layer pattern.

Background: Dry eye disease (DED) is characterized by the loss of ocular surface homeostasis with specific signs and symptoms. Studying the progression of a multifactorial disease is exceedingly challenging for researchers because several factors can influence it. The present study aims to study changes in tear meniscus height (TMH), lipid layer pattern (LLP), and bulbar hyperemia over time in untreated DED participants. Methods: This retrospective longitudinal study included 73 participants (146 eyes) diagnosed with DED since at least 2013. Participants underwent new examinations between 2021 and 2023, grouped by 8-, 6-, or 4-year follow-up periods. TMH, LLP, and bulbar hyperemia were assessed in both examinations. No participant received pharmacological treatment for DED. Results: Differences in TMH, bulbar hyperemia, and LLP between sessions were obtained in the 8-year group (p ≤ 0.027). Differences in bulbar hyperemia and LLP between sessions were obtained in the 6-year group (p ≤ 0.022). The only differences in LLP between sessions were obtained in the 4-year group (p < 0.005). Conclusion: Changes in TMH were obtained after periods of eight years from the first eye examination. Also, changes in bulbar hyperemia were obtained at periods of 8 and 6 years; however, changes in LLP could be found from 4-year follow-ups.

Background: The aim of the present study was to establish a cut-off value of the Lipid Layer Pattern (LLP) between participants with different subtypes of Dry Eye Disease (DED) including Deficient Dry Eye (ADDE), Evaporative Dry Eye (EDE), and Mixed Dry Eye (MDE). Methods: 240 participants diagnosed with DED according to the Tear Film and Ocular Surface Society in the Dry Eye Workshop II guidelines were included in the study. Tear Meniscus Height (TMH) using the Tearscope illumination and Meibomian Gland Loss Area (MGLA) using the Keratograph 5M were assessed to categorize the participants into an ADDE group, EDE group, or MDE group. Then, the LLP was assessed using the Tearscope following the Guillon (LLP-G) and Colour (LLP-C) schemes. Results: Receiver Operating Characteristics (ROC) showed that both LLP-G and LLP-C have no diagnostic potential in distinguishing between ADDE and EDE participants (both p ≥ 0.724). However, to differentiate the ADDE participants from the MDE, ROC procedures showed a good diagnostic potential with cut-off values of Closed Meshwork-Wave (AUC ± SD = 0.609 ± 0.049, p = 0.038, sensitivity: 23.9%; specificity: 76.1%) and Grey-White (AUC ± SD = 0.611 ± 0.050, p = 0.034, sensitivity: 40.7%; specificity: 73.9%) for LLP-G and LLP-C, respectively. Also, a significant potential to distinguish between the EDE from MDE participants was found, with cut-off values of Closed Meshwork (AUC ± SD = 0.604 ± 0.049, p = 0.043, sensitivity: 40.8%; specificity: 76.1%) and Grey-White (AUC ± SD = 0.604 ± 0.051, p = 0.038, sensitivity: 44.7%; specificity: 73.9%) for LLP-G and LLP-C, respectively. Conclusions: Using the Tearscope, both LLP-G and LLP-C has diagnostic potential to distinguish MDE participants from the other subtypes of DED.

Research background. Considering the importance of consumption of berry fruits with proven health-beneficial properties and difficulties in quality control of products of specific botanical and geographic origin, a fingerprint method was developed, based on advanced data analysis (pattern recognition, classification), in order to relate the variability of nutrients in the selected cultivars to primary metabolite profile. Experimental approach. Forty-five samples of genuine berry fruit cultivars (strawberry, raspberry, blackberry, black currant, blueberry, gooseberry, chokeberry, cape gooseberry and goji berry) were characterized according to chromatographic profiles of primary metabolites (sugars, lipids and fatty acids) obtained by three chromatographic techniques (high-performance thin-layer chromatography, gas chromatography coupled to mass spectrometry, and high-performance anion-exchange chromatography with pulsed amperometric detection). Results and conclusions. Comprehensive analysis allowed monitoring and identification of metabolites belonging to polar lipids, mono-, di- and triacylglycerols, free fatty acids, free sterols, sterol esters, mono- to heptasaccharides and sugar alcohols. Chemical fingerprint of berry seeds showed the uniformity of primary metabolites within each fruit species, but revealed differences depending on the botanical origin. All three chromatographic methods provided a discriminative, informative and predictive metabolomics methodology, which proved to be useful for chemotaxonomic classification. Novelty and scientific contribution. A novel methodology for the identification of bioactive compounds from primary metabolites of natural products was described. The proposed untargeted metabolite profiling approach could be used in the future as a routine method for tracing of novel bioactive compounds. The knowledge of metabolite composition obtained in this study can provide a better assessment of genotypic and phenotypic differences between berry fruit species and varieties, and could contribute to the development of new breeding programs.

Prokaryotic microorganisms, comprising Bacteria and Archaea, exhibit a fascinating diversity of cell envelope structures reflecting their adaptations that contribute to their resilience and survival in diverse environments. Among these adaptations, surface layers (S-layers) composed of monomolecular protein or glycoprotein lattices are one of the most observed envelope components. They are the most abundant cellular proteins and represent the simplest biological membranes that have developed during evolution. S-layers provide organisms with a great variety of selective advantages, including acting as an antifouling layer, protective coating, molecular sieve, ion trap, structure involved in cell and molecular adhesion, surface recognition and virulence factor for pathogens. In Archaea that possess S-layers as the exclusive cell wall component, the (glyco)protein lattices function as a cell shape-determining/maintaining scaffold. The wealth of information available on the structure, chemistry, genetics and in vivo and in vitro morphogenesis has revealed a broad application potential for S-layers as patterning elements in a molecular construction kit for bio- and nanotechnology, synthetic biology, biomimetics, biomedicine and diagnostics. In this review, we try to describe the scientifically exciting early days of S-layer research with a special focus on the ‘Vienna-S-Layer-Group’. Our presentation is intended to illustrate how our curiosity and joy of discovery motivated us to explore this new structure and to make the scientific community aware of its relevance in the realm of prokaryotes, and moreover, how we developed concepts for exploiting this unique self-assembly structure. We hope that our presentation, with its many personal notes, is also of interest from the perspective of the history of S-layer research.

Background Dry eye syndrome is one of the most common ocular diseases, and meibomian gland dysfunction (MGD) is the leading cause of evaporative dry eye syndrome. When the tear film lipid layer becomes thin due to obstructive or hyposecretory meibomian gland dysfunction, the excessive evaporation of the aqueous layer can occur, and this causes evaporative dry eye syndrome. Thus, measuring the lipid layer thickness (LLT) is essential for accurate diagnosis and proper treatment of evaporative dry eye syndrome. Methods We used a white LED panel with a slit lamp microscope to obtain videos of the lipid layer interference patterns on the cornea. To quantitatively analyze the LLT from interference colors, we developed a novel algorithm that can automatically perform the following processes on an image frame: determining the radius of the iris, locating the center of the pupil, defining region of interest (ROI), tracking the ROI, compensating for the color of iris and illumination, and producing comprehensive analysis output. A group of dry eye syndrome patients with hyposecretory MGD, dry eye syndrome without MGD, hypersecretory MGD, and healthy volunteers were recruited. Their LLTs were analyzed and statistical information—mean and standard deviation, the relative frequency of LLT at each time point, and graphical LLT visualization—were produced. Results Using our algorithm, we processed the lipid layer interference pattern and automatically analyzed the LLT distribution of images from patients. The LLT of hyposecretory MGD was thinner (45.2 ± 11.6 nm) than that of dry eye syndrome without MGD (69.0 ± 9.4 nm) and healthy volunteers (68.3 ± 13.7 nm) while the LLT of hypersecretory MGD was thicker (93.5 ± 12.6 nm) than that of dry eye syndrome without MGD. Patients’ LLTs were statistically analyzed over time, visualized with 3D surface plots, and displayed using 3D scatter plots of image pixel data for comprehensive assessment. Conclusions We developed an image-based algorithm for quantitative measurement as well as statistical analysis of the LLT despite fluctuation and eye movement. This pilot study demonstrates that the quantitative LLT analysis of patients is consistent with the functions of meibomian glands clinically evaluated by an ophthalmologist. This approach is a significant step forward in developing a fully automated instrument for evaluating dry eye syndrome and for providing proper guidance of treatment.

Soft contact lens (SCL) perturbs the intimate connection between the pre-lens tear film (PLTF) and the ocular surface in various ways, i.e., (i) decrease in tear meniscus radius and aqueous tear thickness, (ii) attenuation of tear film lipid layer spread, (iii) limited wettability of SCL surface, (iv) increased friction with eyelid wiper, etc. This often results in SCL-related dry eye (SCLRDE) manifested as PLTF instability and contact lens discomfort (CLD). In this review, the individual contributions of factors (i–iv) to PLTF breakup patterns (BUP) and CLD are considered via the tear film-oriented diagnosis framework adopted by the Asia Dry Eye Society from a clinical and basic science perspective. It is shown that SCLRDE (due to aqueous deficiency, increased evaporation, or decreased wettability) and BUP of PLTF classify within the same types as the ones observed for the precorneal tear film. The analysis of PLTF dynamics reveals that the inclusion of SCL enhances the manifestation of BUP associated with (i) decreased thickness of PLTF aqueous layer and (ii) limited SCL wettability as shown by the rapid expansion of BUP area. PLTF thinness and instability result in increased blink-related friction and lid wiper epitheliopathy as major contributor to CLD.

The spindle tree (Euonymus europaeus L.) is a much-branched deciduous shrub or small tree. Its fruit capsules contain seeds with remarkably high content of oil interesting for industry, especially the 3-acetyl-1,2-diacyl-sn-glycerols (AcDAG) synthesized by a specific acetyl-CoA diacylglycerol acetyltransferase. The distribution and amount of individual triacylglycerols (TAG) and especially acetyl-triacylglycerols (AcDAG) in Euonymus fruit have previously been assigned to specific tissues. Using anatomical and microscopical observations, we studied the fruit morphology, and for the first time, we identified a more detailed allocation of oil bodies in individual tissue structures. Thin layer chromatography separation of extracts from immature and mature fruits confirmed TAG and AcDAG as the most abundant lipid classes in both endosperm and embryo, followed by fatty acids and polar lipids. The abundance of fatty acids was further studied in the TAG and AcDAG fractions using gas chromatography. Data revealed particular FAs in both fractions allocated in tissue-specific manner and/or as indicators of maturation of E. europaeus seeds. While the abundance of cis-vaccenic-, linoleic as well as α-linolenic acids in the AcDAG structures generally drop with maturation in both embryo and endosperm, content of oleic acid increases. Abundance of cis-vaccenic acid in TAG was recorded in immature endosperm. For embryo, the abundance of stearic acid in AcDAG and oleic acid in TAG fraction was distinctive. Deeper understanding of underlying metabolic processes will be essential for targeted metabolic engineering and/or application for oilseed crops.

Aim. To study the possible protective effect of cannabimimetic lipid - N-stearoylethanolamine (NSE) on the lipid composition of the frontal cortex, hippocampus and on the state of episodic memory of old rats. Methods. Extraction of lipids from the tissues of the hippocampus and frontal cortex of rats was performed by the method of Bligh and Dyer. Phospholipids were separated by two-dimensional thin layer chromatography. Methyl esters of fatty acids from lipid extract were obtained by a modified method of Carreau and Dubaco. Quantitative analysis of fatty acid methyl esters was performed by gas-liquid chromatography on an Agilent GC7890 chromatograph with an Agilent 8987 mass detector. The fractions of free and esterified cholesterol were separated by one-dimensional thin layer chromatography. The dry cholesterol residue was analyzed on a Carlo Erba gas-liquid chromatograph. Results. The study of the diacyl (DF) and plasmalogen (PF) forms of phospholipids (PLs) content in the frontal cortex and hippocampus have shown a significant decrease in the plasmalogen form of PE (Phosphatidylethanolamine) (up to 15%) and an increase in its DF, compare to its content in young rats. Administration of NSE to old rats led to a significant increase in PF PE and did not cause significant changes in the content of PF in the composition of other PL of the frontal cortex of the brain and hippocampus. The decrease in the percentage of various phospholipids was found in frontal cortex and hippocampus of old rats: the content of phosphatidylcholine (PC) and phosphatidylinositol (PI) was significantly reduced in the frontal cortex and the decrease of diphosphatidylglycerol (DPG), PI and phosphatidylserine (PS) was found in the hippocampus, compare to the young animals. Administration of NSE to old rats had a different effects on the content of various phospholipids. The increase in the content of PC and PI in the frontal cortex and PS and DPG in the hippocampus is particularly pronounced due to NSE. An increase in the content of saturated fatty acids (FFAs ) and a decrease in the content of unsaturated FFAs in the frontal cortex and hippocampus of old rats also has been found. It has also been found that NSE administration to old rats promoted the growth of the free cholesterol level in the frontal cortex and hippocampus. The results of the New Object Recognition test in old rats have shown that a short-term memory has been improved by NSE. Conclusions. The administration of NSE to old rats causes an increase in PF of PLs in the frontal cortex and hippocampus of the brain, which can be considered as one of the mechanisms of neuroprotective action of NSE in aging. The changes in the phospholipids and fatty acids composition, and free cholesterol level of the frontal cortex and hippocampus of the brain of old rats caused by NSE administration have been shown to be adaptive and restorative. The New Object Recognition Behavioral Test has shown that NSE restores short-term memory in older rats. The obtained results expand the understanding of the mechanisms of biological action of NSE during aging in mammals and create the basis for the development a new drug with geroprotective properties.

The objective of this study is to develop a universally applicable approach for establishing the optimal dose range for the irradiation of plant and animal products. The approach involves the use of the optimization function for establishing the optimal irradiation dose range for each category of plant and animal product to maximize the suppression of targeted pathogens while preserving the surrounding molecules and biological structures. The proposed function implies that pathogens found in the product can be efficiently suppressed provided that irradiation is performed with the following criteria in mind: a high irradiation dose uniformity, a high probability of irradiation hitting pathogens and controlled heterogeneity of radiobiological sensitivity of pathogens. This study compares the optimal dose ranges for animal and plant products using beef tenderloin and seed potato tubers as examples. In a series of experiments, our team traced the dose dependencies of myoglobin oxidation in beef and the amount of potential damage to albumin’s native structure. The behavior patterns of myoglobin derivatives and the amount of potential damage to albumin found in this study determined the optimal dose range, which appeared to be wider for beef irradiation compared to that for seed potato tubers, as they do not require uniform irradiation of the entire volume since targeted phytopathogens are predominantly found within the surface layers of the tubers. The use of proprietary methods involving spectrophotometry and high-performance liquid chromatography–mass spectrometry provides a novel perspective on the quantitative assessment of the myoglobin oxidation level and the potential damage to albumin’s native structure.