Biomedical subjects

Lingyun Chen

Publications and source records attributed to Lingyun Chen.

9 recordsLinked to original sources

PubMed2025

Experimental study on the role and biomarker potential of CX3CR1 in osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a chronic joint disorder marked by progressive degeneration of articular cartilage and the formation of secondary osteophytes. Despite extensive research, the underlying molecular mechanisms remain poorly understood. This study aimed to identify OA-associated genes and elucidate the molecular pathways implicated, with the goal of discovering reliable diagnostic biomarkers. METHODS: The microarray dataset was retrieved from the Gene Expression Omnibus (GEO) and analyzed using R software to identify the signature gene, CX3CR1. Differentially expressed genes (DEGs) correlated with CX3CR1 were subsequently subjected to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and immune infiltration analyses. A ceRNA regulatory network was also constructed. Vali-dation of CX3CR1 expression was conducted through qRT-PCR, Western blotting, and immunohistochemistry. RESULTS: CX3CR1 emerged as a candidate gene significantly associated with OA, exhibiting regulatory roles primarily in lipid metabolism-related and extra-cellular matrix-related biological processes and signaling cascades. The infiltration levels of immune cells, particularly activated mast cells, appeared to modulate OA progression. Both in vitro and in vivo experiments demonstrated elevated CX3CR1 expression in OA tissues relative to controls, with a robust positive correlation observed between CX3CR1 and MMP13 levels. CONCLUSION: CX3CR1 represents a potential biomarker for OA diagnosis and therapeutic targeting, exerting its effects by modulating lipid metabolism, extracellular matrix dynamics, and immune cell infiltration.

CX3C Chemokine Receptor 1↗

PubMed2006

Effect of preparation conditions on the nutrient release properties of alginate-whey protein granular microspheres.

The effect of preparation conditions on nutrient release from alginate (AL)-whey protein isolate (WPI) granular microspheres obtained by an emulsification/internal cold gelation method was studied by varying WPI/AL ratio, microsphere diameter, total polymer concentration and riboflavin loading. Microsphere size distribution and nutrient encapsulation efficiency (EE) were examined. Riboflavin release profiles were investigated in simulated gastric and intestinal fluids. Values for EE above 80% were obtained for most microspheres, with the notable exceptions of high AL or pure AL. Variations in WPI/AL ratio, granule size and nutrient loading have major impact on nutrient release. Microspheres prepared with a WPI/AL ratio of 8:2, a riboflavin concentration of 1% in the initial aqueous phase and diameters near 94 microm retained the vitamin in SGF and released it in SIF. By careful process design, granular microspheres with potential as oral delivery vehicles for bioactive compounds may be developed.

Administration, Oral↗

PubMed2006

Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG.

Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species. The 2D electrophoresis and immunoblots revealed species-specific differences in proteins that appear to represent various numbers of isoforms of parvalbumin in carp (5), catfish (3), cod (1) and tilapia (2). No parvalbumin was detected in yellowfin tuna. Based on minor differences in relative intensities of protein staining and immunodetection, parvalbumin isoforms may have slight differences in the epitope region recognized by the anti-frog parvalbumin antibody. These results suggest that the frog anti-parvalbumin antibody can be used as a valuable tool to detect parvalbumins from the fish tested in this study, except yellowfin tuna.

Allergens↗

PubMed2006

Alginate-whey protein granular microspheres as oral delivery vehicles for bioactive compounds.

Alginate (AL)-whey protein isolate (WPI) microspheres of varied WPI/AL ratio, particle diameter and concentration of polymer bead forming solution (C(AL+WPI)) were prepared in order to develop a biocompatible vehicle for oral administration of bioactive compounds. Microscopy revealed a special matrix/granular structure for microspheres with a WPI/AL ratio of 8:2, 100 microm diameter and C(AL+WPI) of 5% (AL-WPI A2), featuring WPI granules 3-10 microm in diameter homogeneously distributed within an AL spherical matrix. The compound release properties of these microspheres were investigated in simulated gastric and intestinal fluids (SGF and SIF). They demonstrated the desirable property of retarding riboflavin release in SGF and underwent alginate matrix erosion together with liberation of WPI granules in SIF, followed by complete release of the riboflavin. Riboflavin release in SGF and in SIF without pancreatin followed the Higuchi diffusion model while release in SIF in the presence of pancreatin was attributed to WPI granule degradation.

Administration, Oral↗

PubMed2006

Noise simulation in cone beam CT imaging with parallel computing.

We developed a computer noise simulation model for cone beam computed tomography imaging using a general purpose PC cluster. This model uses a mono-energetic x-ray approximation and allows us to investigate three primary performance components, specifically quantum noise, detector blurring and additive system noise. A parallel random number generator based on the Weyl sequence was implemented in the noise simulation and a visualization technique was accordingly developed to validate the quality of the parallel random number generator. In our computer simulation model, three-dimensional (3D) phantoms were mathematically modelled and used to create 450 analytical projections, which were then sampled into digital image data. Quantum noise was simulated and added to the analytical projection image data, which were then filtered to incorporate flat panel detector blurring. Additive system noise was generated and added to form the final projection images. The Feldkamp algorithm was implemented and used to reconstruct the 3D images of the phantoms. A 24 dual-Xeon PC cluster was used to compute the projections and reconstructed images in parallel with each CPU processing 10 projection views for a total of 450 views. Based on this computer simulation system, simulated cone beam CT images were generated for various phantoms and technique settings. Noise power spectra for the flat panel x-ray detector and reconstructed images were then computed to characterize the noise properties. As an example among the potential applications of our noise simulation model, we showed that images of low contrast objects can be produced and used for image quality evaluation.

Algorithms↗

PubMed2006

Evaluation of IgE binding to proteins of hardy (Actinidia arguta), gold (Actinidia chinensis) and green (Actinidia deliciosa) kiwifruits and processed hardy kiwifruit concentrate, using sera of individuals with food allergies to green kiwifruit.

BACKGROUND: Allergy to green kiwifruit has become common since the fruit was introduced in North America and Europe 30 years ago. Gold kiwifruit, more recently introduced commercially, has been shown to bind IgE from some individuals allergic to green kiwifruit. Hardy kiwifruit is a third species that is now cultivated in North America with potential application as a fresh fruit and in processed foods. OBJECTIVE: To compare the IgE binding properties of proteins in hardy kiwifruit extract and processed hardy kiwifruit concentrate to each other and to extracts of green and gold kiwifruits to evaluate the potential for allergic cross-reactions. METHODS: Sera from kiwifruit-allergic subjects and individuals without allergies to kiwifruit were assayed for IgE binding to soluble proteins in green, gold and hardy kiwifruits and heat-processed concentrate from hardy kiwifruit using immunoblots and direct enzyme-linked immunosorbent assay (ELISA). RESULTS: Marked IgE binding to specific hardy kiwifruit proteins was identified. However, IgE binding to heat-processed hardy kiwifruit concentrate was remarkably lower than to the raw fruit extract. CONCLUSIONS: These results suggest that some kiwifruit-allergic individuals may suffer allergic cross-reactions if they consume raw hardy kiwifruit. However, heat processing of the hardy kiwifruit alters allergenic protein structure, dramatically reducing in vitro IgE binding. Processing likely reduces the risk of eliciting an allergic response in those with allergies to raw kiwifruit.

Actinidia↗

PubMed2005

Chitosan/beta-lactoglobulin core-shell nanoparticles as nutraceutical carriers.

Chitosan (CS)/beta-lactoglobulin (betalg) core-shell nanoparticles (CS-betalg nanoparticle) were successfully prepared with the aim of developing a biocompatible carrier for the oral administration of nutraceuticals. The effects of pH and initial concentrations (C(beta)(lg)) of native and denatured betalg on the properties of the nanoparticles were investigated. Uniform nanoparticles were prepared by ionic gelation with sodium tripolyphosphate (TPP). The surface charge of the particles was positive, with a zeta potential of 20-60 mV. (beta)lg loading efficiency (LE) spanned a broad range (1-60%); and was highly sensitive to formulation pH. This adsorption can be mainly attributed to electrostatic, hydrophobic interactions and hydrogen bonding between (beta)lg and CS. Brilliant blue (BB) release experiments showed that the nanoparticles prepared with native (beta)lg had favorable properties to resist acid and pepsin degradation in simulated gastric conditions unlike those prepared with denatured (beta)lg or denatured (beta)lg crosslinked with Ca2+. When transferred to simulated intestinal conditions, the (beta)lg shells of the nanoparticles were degraded by pancreatin.

Adsorption↗

PubMed2004

Synthesis and pH sensitivity of carboxymethyl chitosan-based polyampholyte hydrogels for protein carrier matrices.

Novel polyampholyte hydrogels based on carboxymethyl chitosans (CMC) of various degree of deacetylation (DD) and substitution (DS) were prepared by crosslinking with glutaraldehyde. The hydrogel showed typical amphoteric character responding to pH of the external medium. At the isoelectric point (IEP), the hydrogel shrunk most, when the pH deviated from IEP, the swelling degree (Ds) increased. With increasing DD or DS value, the hydrogel changed from polyampholyte into polycations or polyanions, respectively. Osmotic forces and intermolecular interactions among CMC chains regulate the swelling behavior of CMC gel. The carboxymethyl chitin hydrogels were loaded with bovine blood proteins (BSA), and their release studies were performed in both the simulated gastric and intestinal pH conditions. The release was much quicker in pH 7.4 buffer than pH 1.2 solution; the release followed Fickian diffusion in the first 4h and then steadily increased with the dissolution of the hydrogels.

Absorption↗

PubMed2003

Relationships between the molecular structure and moisture-absorption and moisture-retention abilities of carboxymethyl chitosan. II. Effect of degree of deacetylation and carboxymethylation.

Carboxymethyl chitosans (CM-chitosan) of various degrees of deacetylation (DD 28-95%) and substitution (DS 0.15-1.21) were successfully prepared from N-acetylchitosans in NaOH of varying concentrations. Infrared spectroscopy (IR), elemental analysis, potentiometric titration, 13C NMR, X-ray diffraction and gel-permeation chromatographic (GPC) techniques were used to characterize their molecular structures. The moisture-absorption (R(a)) and -retention (R(h)) abilities of CM-chitosan are closely related to the DD and DS values. Under conditions of high relative humidity, the maximum R(a) and R(h) were obtained at DD values of about 50%, and when the DD value deviated from 50%, R(a) and R(h) decreased. Under dry conditions, when the DD value was 50%, the R(h) was the lowest. With the DS value increasing, R(a) and R(h) increased. However, further increase of the DS value above 1.0 reduced the increasing tendency of R(a) and R(h), and even some decreases in R(a) and R(h) were observed. Intermolecular hydrogen bonds play a very important role in moisture-absorption and retention ability of CM-chitosan.

Absorption↗