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[IEEE 2018 IEEE XXV International Conference on Electronics, Electrical Engineering and Computing (INTERCON) - Lima (2018.8.8-2018.8.10)] 2018 IEEE XXV International Conference on Electronics, Electrical Engineering and Computing (INTERCON) - An Algorithm for The Quantification of Lipids, Collagen and Muscle Cells in Coronary Arteries Based on Digital Image Processing
摘要： The present study presents a method to quantify lipids, collagen and muscle cells, to help diagnose atherosclerosis using digital image processing techniques. The relative concentrations of these three indicators are crucial in diagnosing atherosclerosis in patients. Digital image processing techniques such as object detection, color enhancement, and shape and texture analysis were used to quantify cells. The objective of the algorithm is to analyze high definition images of coronary arteries and to provide an objective outcome on the atherosclerotic tissue stage. The algorithm presented outstanding results and an innovative method to diagnose atherosclerosis when compared to existing procedures in the literature.
关键词： coronary heart tissue,lipids,quantification,muscle cells,Digital Image Processing,collagen
更新于2025-09-23 15:23:52
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Changes of Intracellular Porphyrin, Reactive Oxygen Species, and Fatty Acids Profiles During Inactivation of Methicillin-Resistant Staphylococcus aureus by Antimicrobial Blue Light
摘要： Antimicrobial blue light (aBL) has attracted increasing interest for its antimicrobial properties. However, the underlying bactericidal mechanism has not yet been verified. One hypothesis is that aBL causes the excitation of intracellular chromophores; leading to the generation of reactive oxygen species (ROS) and the resultant oxidization of various biomolecules. Thus, monitoring the levels of redox-sensitive intracellular biomolecules such as coproporphyrins, as well as singlet oxygen and various ROS may help to uncover the physiological changes induced by aBL and aid in establishing the underlying mechanism of action. Furthermore, the identification of novel targets of ROS, such as fatty acids, is of potential significance from a therapeutic perspective. In this study, we sought to investigate the molecular impact of aBL treatment on methicillin-resistant Staphylococcus aureus (MRSA). The results showed that aBL (5–80 J/cm2) exhibited a bactericidal effect on MRSA, and almost no bacteria survived when 80 J/cm2 had been delivered. Further studies revealed that the concentrations of certain intracellular molecules varied in response to aBL irradiation. Coproporphyrin levels were found to decrease gradually, while ROS levels increased rapidly. Moreover, imaging revealed the emergence and increase of singlet oxygen molecules. Concomitantly, the lipid peroxidation product malondialdehyde (MDA) increased in abundance and intracellular K+ leakage was observed, indicating permeability of the cell membrane. Atomic force microscopy showed that the cell surface exhibited a coarse appearance. Finally, fatty acid profiles at different illumination levels were monitored by GC-MS. The relative amounts of three unsaturated fatty acids (C16:1, C20:1, and C20:4) were decreased in response to aBL irradiation, which likely played a key role in the aforementioned membrane injuries. Collectively, these data suggest that the cell membrane is a major target of ROS during aBL irradiation, causing alterations to membrane lipid profiles, and in particular to the unsaturated fatty acid component.
关键词： membrane injuries,coproporphyrin,lipids,methicillin-resistant Staphylococcus aureus,antimicrobial blue light,unsaturated fatty acids
更新于2025-09-23 15:22:29
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Carotenoids co-localize with hydroxyapatite, cholesterol, and other lipids in calcified stenotic aortic valves. Ex vivo Raman maps compared to histological patterns
摘要： Unlike its application for atherosclerotic plaque analysis, Raman microspectroscopy was sporadically used to check the sole nature of bioapatite deposits in stenotic aortic valves, neglecting the involvement of accumulated lipids/lipoproteins in the calcific process. Here, Raman microspectroscopy was employed for examination of stenotic aortic valve leaflets to add information on nature and distribution of accumulated lipids and their correlation with mineralization in the light of its potential precocious diagnostic use. Cryosections from surgically explanted stenotic aortic valves (n=4) were studied matching Raman maps against specific histological patterns. Raman maps revealed the presence of phospholipids/triglycerides and cholesterol, which showed spatial overlapping with one another and Raman-identified hydroxyapatite. Moreover, the Raman patterns correlated with those displayed by both von-Kossa-calcium- and Nile-blue-stained serial cryosections. Raman analysis also provided the first identification of carotenoids, which co-localized with the identified lipid moieties. Additional fit concerned the distribution of collagen and elastin. The good correlation of Raman maps with high-affinity staining patterns proved that Raman microspectroscopy is a reliable tool in evaluating calcification degree, alteration/displacement of extracellular matrix components, and accumulation rate of different lipid forms in calcified heart valves. In addition, the novel identification of carotenoids supports the concept that valve stenosis is an atherosclerosis-like valve lesion, consistently with their previous Raman microspectroscopical identification inside atherosclerotic plaques.
关键词： lipids,Valve calcification,Raman microspectroscopy,stenosis,carotenoids
更新于2025-09-23 15:22:29
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Quantitative imaging of membrane micropolarity in living cells and tissues by spectral phasors analysis
摘要： Intracellular micropolarity is essential in several metabolic processes, as it controls membrane permeability, fluxes of molecules and energy. Here we describe a method for the determination of the micropolarity in living cells using spectral confocal microscopy. The method is based on a phasor analysis of spectrally resolved images of live cells, labelled with the solvatochromic probe Nile Red. An application is provided to extract a polarity profile from the acquired Spectral datasets, which represent the contribution of hyperpolar, polar and non-polar lipids, and to generate a micropolarity map at submicrometric spatial resolution. A metabolic parameter, representing a quantitative index of the fatty acid-triacylglycerol turnover, is also furnished. This method allows a functional profiling of cells and tissues and the detection of metabolic imbalances between lipid storage and usage.
关键词： Membranes micropolarity,Nile Red,Fatty acids,Triglycerides,Lipid droplets,Confocal microscopy,Metabolic imaging,Spectral phasors,Lipids
更新于2025-09-23 15:22:29
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Near-infrared irradiation affects lipid metabolism in neuronal cells, inducing lipid droplets formation
摘要： It is known that lipids play an outstanding role in cellular regulation and their dysfunction has been linked to many diseases. Thus, modulation of lipid metabolism may provide new pathways for disease treatment or prevention. In this work, near infrared (NIR) light was applied to modulate lipid metabolism, and increase intracellular lipid content in rat cortical neurons (RCN). Using label-free CARS microscopy, we have monitored the intracellular lipid content in RCN at a single cell level. A major increase in average level of lipid per cell after treatment with laser diode at 808 nm was found, nonlinearly dependent on the irradiation dose. Moreover, a striking formation of lipid droplets (LDs) in the irradiated RCN was discovered. Further experiments and analysis reveal a strong correlation between NIR light induced generation of reactive oxygen species (ROS), lipids level and LDs formation in RCN. Our findings can contribute to a development of therapeutic approaches for neurological disorders via NIR light control of lipid metabolism in neuronal cells.
关键词： CARS imaging,neuronal cells.,ROS,NIR light,lipids
更新于2025-09-23 15:21:21
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Hybrid quantum dot-based theranostic nanomedicines for tumor-targeted drug delivery and cancer imaging
摘要： Quantum dots (QDs) are considered one of the most efficient tools used in theranostic applications for diagnosis and therapy due to their unique physiochemical characteristics. QDs are semiconductor crystals in the nano-scale range of 2–10 nm which exhibit unique photoluminescence characteristics as well as electronic properties such as tunable emission from visible to near infrared wavelengths and superior light stability. QDs possess strong photoluminescence with high molar extinction coefficient values, which make them the best candidates for cell labeling and detection of cancer biomarkers. QDs are characterized by symmetric narrow-emission spectra and broad-absorption spectra. However, some fears have been raised regarding the toxicity of QDs, especially Cd-containing QDs, due to the release of Cd ions and the generation of reactive oxygen species. Therefore, strategies have been developed to reduce their toxicity and enhance their biocompatibility through hybridization with other moieties such as polymers, proteins, polysaccharides or lipids, offering efficient tumor targeting in addition to inhibiting their release into the systemic circulation. This article discusses QD-based nanohybrids for delivery of anticancer drugs in combination with cancer imaging.
关键词： lipids,proteins,nanohybrids,tumor targeting,inorganic nanoparticles,polymers,cancer theranostics,quantum dots,polysaccharides,drug delivery
更新于2025-09-19 17:15:36
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Mass Spectrometry Imaging of Triglycerides in Biological Tissues by Laser Desorption Ionization from Silicon Nanopost Arrays
摘要： Mass spectrometry imaging (MSI) is used increasingly to simultaneously detect a broad range of biomolecules, while mapping their spatial distributions within biological tissue sections. Matrix-assisted laser desorption ionization (MALDI) is recognized as the method-of-choice for MSI applications due in part to its broad molecular coverage. In spite of the remarkable advantages offered by MALDI, imaging of neutral lipids, such as triglycerides (TGs), from tissue has remained a significant challenge due to ion suppression of TGs by phospholipids, e.g., phosphatidylcholines (PCs). To help overcome this limitation, silicon nanopost array (NAPA) substrates were introduced to selectively ionize TGs from biological tissue sections. This matrix-free laser desorption ionization (LDI) platform was previously shown to provide enhanced ionization of certain lipid classes, such as hexosylceramides (HexCers) and phosphatidylethanolamines (PEs) from mouse brain tissue. In this work, we present NAPA as an MSI platform offering enhanced ionization efficiency for TGs from biological tissues relative to MALDI, allowing it to serve as a complement to MALDI-MSI. Analysis of a standard lipid mixture containing PC(18:1/18:1) and TG(16:0/16:0/16:0) by LDI from NAPA provided an ~49 and ~227-fold higher signal for TG(16:0/16:0/16:0) relative to MALDI, when analyzed without and with the addition of a sodium acetate, respectively. In contrast, MALDI provided an ~757 and ~295-fold higher signal for PC(18:1/18:1) compared to NAPA, without and with additional Na+. Averaged signal intensities for TGs from MSI of mouse lung and human skin tissues exhibited an ~105 and ~49-fold increase, respectively, with LDI from NAPA compared to MALDI. With respect to PCs, MALDI provided an ~2 and ~19-fold increase in signal intensity for mouse lung and human skin tissues, respectively, when compared to NAPA. The complementary coverage obtained by the two platforms demonstrates the utility of using both techniques to maximize the information obtained from lipid MS or MSI experiments.
关键词： laser desorption ionization,Mass spectrometry imaging,NAPA,nanopost array,lipids,triglycerides
更新于2025-09-19 17:13:59
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Bacterial identification by lipid profiling using liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry
摘要： Background: In recent years, mass spectrometry (MS) has been applied to clinical microbial biotyping, exploiting the speed of matrix-assisted laser desorption/ionization (MALDI) in recording microbe-specific MS profiles. More recently, liquid atmospheric pressure (AP) MALDI has been shown to produce extremely stable ion flux from homogenous samples and ‘electrospray ionization (ESI)-like’ multiply charged ions for larger biomolecules, whilst maintaining the benefits of traditional MALDI including high tolerance to contaminants, low analyte consumption and rapid analysis. These and other advantages of liquid AP-MALDI MS have been explored in this study to investigate its potential in microbial biotyping. Methods: Genetically diverse bacterial strains were analyzed using liquid AP-MALDI MS, including clinically relevant species such as Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Bacterial cultures were subjected to a simple and fast extraction protocol using ethanol and formic acid. Extracts were spotted with a liquid support matrix (LSM) and analyzed using a Synapt G2-Si mass spectrometer with an in-house built AP-MALDI source. Results: Each species produces a unique lipid profile in the m/z range of 400–1100, allowing species discrimination. Traditional (solid) MALDI MS produced spectra containing a high abundance of matrix-related clusters and an absence of lipid peaks. The MS profiles of the bacterial species tested form distinct clusters using principle component analysis (PCA) with a classification accuracy of 98.63% using a PCA-based prediction model. Conclusions: Liquid AP-MALDI MS profiles can be sufficient to distinguish clinically relevant bacterial pathogens and other bacteria, based on their unique lipid profiles.
关键词： matrix-assisted laser desorption/ionization,mass spectrometry,bacteria,profiling,speciation,MALDI,biotyping,lipids
更新于2025-09-16 10:30:52
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Lipid Droplet Composition Varies Based on Medaka Fish Eggs Development as Revealed by NIR-, MIR-, and Raman Imaging
摘要： In fertilized fish eggs, lipids are an energy reservoir for the embryo development and substrate for organogenesis. They occur in the cytoplasmic area and form lipid droplets (LDs), but also the yolk egg is composed of lipids and proteins. Insight on the LD formation and distribution and their interactions with other cellular organelles could provide information about the role based on the egg development. For non-destructive, macro-scale visualization of biochemical components of fish eggs, such as lipids proteins and water, near-infrared (NIR) imaging is the method of choice. Mid-infrared (MIR) and Raman spectroscopy imaging were used to provide details on chemical composition of LDs and other egg organelles. NIR imaging illustrated main compartments of the egg including membrane, LDs, yolk, relative protein, and lipid content in well-localized egg structures and their interactions with water molecules. In the yolk, a co-existence of lipids and proteins with carotenoids and carbohydrates was detected by Raman spectroscopy. Results showed a prominent decrease of unsaturated fatty acids, phospholipids, and triglycerides/cholesteryl esters content in the eggs due to the embryo development. An opposite trend of changes was observed by MIR spectroscopy for the glycogen, suggesting that consumption of lipids occurred with production of this carbohydrate. The comprehensive vibrational spectroscopic analysis based on NIR, MIR, and Raman imaging is a unique tool in studying in situ dynamic biological processes.
关键词： near- and mid-infrared spectroscopic imaging,Raman spectroscopic imaging,lipids,lipid bodies,fertilized egg
更新于2025-09-16 10:30:52
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Application of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging for Food Analysis
摘要： Food contains various compounds, and there are many methods available to analyze each of these components. However, the large amounts of low-molecular-weight metabolites in food, such as amino acids, organic acids, vitamins, lipids, and toxins, make it difficult to analyze the spatial distribution of these molecules. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging is a two-dimensional ionization technology that allows the detection of small metabolites in tissue sections without requiring purification, extraction, separation, or labeling. The application of MALDI-MS imaging in food analysis improves the visualization of these compounds to identify not only the nutritional content but also the geographical origin of the food. In this review, we provide an overview of some recent applications of MALDI-MS imaging, demonstrating the advantages and prospects of this technology compared to conventional approaches. Further development and enhancement of MALDI-MS imaging is expected to offer great benefits to consumers, researchers, and food producers with respect to breeding improvement, traceability, the development of value-added foods, and improved safety assessments.
关键词： nutrition factor,neuropeptides,MALDI-MS imaging,amino acids,lipids
更新于2025-09-12 10:27:22