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Morphological and elemental mapping of gallstones using synchrotron microtomography and synchrotron X‐ray fluorescence spectroscopy
摘要： Background and Aim: Regional differences in gallstone (GS) composition are well documented in the Indian subcontinent. The reasons for the same are unknown. Etiopathogenesis of GS remains elusive despite advances in instrumentation. This was an in-depth analysis of the chemical, structural, and elemental composition of GS with special reference to synchroton studies. Methods: We used high-end sensitive analytical complementary microscopic and spectroscopic methods techniques, such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared, synchrotron X-ray fluorescence spectroscopy (SR-XRF), and 2D and 3D synchrotron microtomography (SR-μCT), to study the ultra structure and trace element composition of three major types of GS (cholesterol, mixed, and pigment). SR-XRF quantified the trace elements in GS. Results: The cholesterol GS (monohydrate and anhydrate) were crystalline, with high calcium content. The pigment GS were amorphous, featureless, black, and fragile, with high calcium bilirubinate and carbonate salts. They had the highest concentration of iron (average 31.50 ppm) and copper (average 92.73 ppm), with bacterial inclusion. The mixed stones had features of both cholesterol and pigment GS with intermediate levels of copper (average 20.8 ppm) and iron (average 17.78 ppm). Conclusion: SR-μCT has, for the first time, provided cross-sectional computed imaging delineating the framework of GS and mineral distribution. It provided excellent mapping of cholesterol GS. SR-XRF confirmed that pigment GS had high concentrations of copper and iron with bacterial inclusions, the latter possibly serving as a nidus to the formation of these stones.
关键词： pigment,microtomography,gallstones,cholesterol,elemental,synchroton
更新于2025-11-21 11:18:25
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Effects of Cytokine Activation and Oxidative Stress on the Function of the Human Embryonic Stem Cell–Derived Retinal Pigment Epithelial Cells
摘要： PURPOSE. In several retinal complications, such as age-dependent macular degeneration (AMD), oxidative stress is increased and cytokine level is elevated. These are shown to alter the activation and expression of matrix metalloproteinase (MMP) both in human primary and immortalized retinal pigment epithelial (RPE) cells. However, the effects on human embryonic stem cell (hESC)–derived RPE cells remain to be elucidated. METHODS. The mature hESC-RPE cells were exposed to inflammatory cytokines (IFN-γ or TNF-α) for 24 hours or oxidative stress (H2O2) for 1 hour. Effects on barrier properties were analyzed with transepithelial electrical resistance (TEER), the expression of MMP-1, MMP-2, MMP-3, MMP-9, collagen I, and collagen IV genes with quantitative RT-PCR, and the expression of MMP-1 and MMP-3 proteins with Western blot or ELISA, respectively. Also, activation and secretion of MMP-2 and -9 proteins were analyzed with zymography. RESULTS. In normal state, mature hESC-RPE cells expressed MMP-1, -2, -3, and -9 genes in low levels, respectively. Tumor necrosis factor-α increased MMP-1 and -2 gene expression, and H2O2 increased MMP-3 and -9 gene expression. Zymography revealed IFN-γ– and TNF-α–induced secretion of MMP-2 and high-molecular-weight species of MMP (HMW MMP), but H2O2 decreased their secretion. Furthermore, TNF-α and H2O2 significantly decreased barrier properties. CONCLUSIONS. Here, cytokines induced the MMP-1 and -2 gene and protein expression. Also, H2O2 induced MMP-3 and -9 gene expression, but not their protein secretion. These data propose that under oxidative stress and cytokine stimuli, mature hESC-RPE cells resemble their native counterpart in the human eye in regard to MMP secretion and expression and could be used to model retinal disorders involving alterations in MMP activity such as AMD, diabetic retinopathy, or proliferative vitreoretinopathy in vitro.
关键词： matrix metalloproteinase,MMP,stem cells,retinal pigment epithelium
更新于2025-11-21 11:08:12
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Functional Assessment of Patient-Derived Retinal Pigment Epithelial Cells Edited by CRISPR/Cas9
摘要： Retinitis pigmentosa is the most common form of inherited blindness and can be caused by a multitude of different genetic mutations that lead to similar phenotypes. Specifically, mutations in ubiquitously expressed splicing factor proteins are known to cause an autosomal dominant form of the disease, but the retina-specific pathology of these mutations is not well understood. Fibroblasts from a patient with splicing factor retinitis pigmentosa caused by a missense mutation in the PRPF8 splicing factor were used to produce three diseased and three CRISPR/Cas9-corrected induced pluripotent stem cell (iPSC) clones. We differentiated each of these clones into retinal pigment epithelial (RPE) cells via directed differentiation and analyzed the RPE cells in terms of gene and protein expression, apicobasal polarity, and phagocytic ability. We demonstrate that RPE cells can be produced from patient-derived and corrected cells and they exhibit morphology and functionality similar but not identical to wild-type RPE cells in vitro. Functionally, the RPE cells were able to establish apicobasal polarity and phagocytose photoreceptor outer segments at the same capacity as wild-type cells. These data suggest that patient-derived iPSCs, both diseased and corrected, are able to differentiate into RPE cells with a near normal phenotype and without differences in phagocytosis, a result that differs from previous mouse models. These RPE cells can now be studied to establish a disease-in-a-dish system relevant to retinitis pigmentosa.
关键词： retinal pigment epithelial cells,CRISPR/Cas9,retinitis pigmentosa,PRPF8,induced pluripotent stem cells
更新于2025-09-23 15:23:52
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Isolation and Culture of Primary Mouse Retinal Pigment Epithelial (RPE) Cells with Rho-Kinase and TGFβR-1/ALK5 Inhibitor
摘要： Primary RPE cells could be a reliable model for representing in vivo status of RPE compared with cell lines. We present a protocol for in vitro isolation and culture of primary RPE cells from C57BL mice. We used C57BL mice ages 7 days to 4 months. The RPE layer was separated from the neural retina layer by digestion with 2% Dispase for 45 min and scraped off from the choroid after 25-min incubation in 37°C. Collected RPE sheets were gently pipetted up into smaller sheets. RPE sheets were transferred into well plates and cultured in vitro for 2 weeks. To inhibit epithelial-mesenchymal transition (EMT) of RPE cells, we used Y27632 and Repsox to treat cultured primary RPE cells. RPE cells isolated from C57BL mice maintained pigmented and hexagonal morphology in culture. However, long-term in vitro culture lead to the periphery cells of a RPE sheet becoming mesenchymal-like cells. In contrast to the control group, Y27632 and Repsox, which are inhibitors of Rho-kinase or TGFbR-1/ALK5, promoted primary RPE cells to maintain epithelial-like morphology and eventually become confluent. RPE cells isolated from C57BL mice could be a powerful cell model to study the biological function of RPE. Especially, C57BL mice with different defective genetic background resulting in ocular diseases, would expand the genome type of RPE cells. The method presented here could be an efficient and applicable technique to obtain large numbers of primary RPE cells that maintain some characteristics of in vivo RPE.
关键词： Primary Cell Culture,Mice,Retinal Pigment Epithelium,Inbred C57BL
更新于2025-09-23 15:23:52
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P-12.5: High Transmittance Color Filter of Hybrid
摘要： The particles of pigment can scatter source light, using a dye reduces the proportion of pigment, so the transmittance was improved nicely. The hybrid color filter also exhibit tuneable emission characteristics, another the hue of dye is better, thus higher purity red, green and Blue (RGB) primary colors be got, the hybrid also can be used in wide-color-gamut products, the transmittance enhance 10%～13% in C-light and 10%～12% in backlight (BL) at the white balance.
关键词： Pigment,C-light,Hybrid,Backlight,Transmission ratio,Color filter,Wide color gamut,Liquid crystal display,Dye
更新于2025-09-23 15:23:52
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Aberrant Activity of TAK1 is Associated with Retinal Pathology
摘要： Transforming growth factor-β-activated kinase-1 (TAK1) is a mitogen activated protein kinase kinase kinase that is involved in diverse biological roles across species. Functioning downstream of TGF-β, TAK1 mediates the activation of the c-Jun N-terminal kinase (JNK) signaling pathway, serves as the target of pro-inflammatory cytokines, such as TNF-α, mediates NF-κβ activation, and plays a role in Wnt signaling in mesenchymal stem cells. Still, the expression of TAK1 in the retina has not been defined. In our study, pathological and immunohistochemical assessments indicate a link between retinal pathology and TAK1 phosphorylation. We observed similar TAK1 expression both in non-obvious and obvious retinal pathologies. However, the phosphorylated form of TAK1 in the segments of retina with obvious pathology was hardly detected compared to its expression in the segments with non-obvious pathology. This finding indicates, for the first time, a possible involvement of TAK1 in human retinal pathologies. Better understanding the expression pattern of TAK1 may serve as a new therapeutic avenue for retinal pathologies.
关键词： Phosphorylation,Retinal pigment epithelium (RPE),Transforming growth factor-β-activated kinase 1 (TAK1)
更新于2025-09-23 15:23:52
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RefMoB, a Reflectivity Feature Model-Based Automated Method for Measuring Four Outer Retinal Hyperreflective Bands in Optical Coherence Tomography
摘要： PURPOSE. To validate a model-driven method (RefMoB) of automatically describing the four outer retinal hyperreflective bands revealed by spectral-domain optical coherence tomography (SDOCT), for comparison with histology of normal macula; to report thickness and position of bands, particularly band 2 (ellipsoid zone [EZ], commonly called IS/OS). METHODS. Foveal and superior perifoveal scans of seven SDOCT volumes of five individuals aged 28 to 69 years with healthy maculas were used (seven eyes for validation, five eyes for measurement). RefMoB determines band thickness and position by a multistage procedure that models reflectivities as a summation of Gaussians. Band thickness and positions were compared with those obtained by manual evaluators for the same scans, and compared with an independent published histological dataset. RESULTS. Agreement among manual evaluators was moderate. Relative to manual evaluation, RefMoB reported reduced thickness and vertical shifts in band positions in a band-specific manner for both simulated and empirical data. In foveal and perifoveal scans, band 1 was thick relative to the anatomical external limiting membrane, band 2 aligned with the outer one-third of the anatomical IS ellipsoid, and band 3 (IZ, interdigitation of retinal pigment epithelium and photoreceptors) was cleanly delineated. CONCLUSIONS. RefMoB is suitable for automatic description of the location and thickness of the four outer retinal hyperreflective bands. Initial results suggest that band 2 aligns with the outer ellipsoid, thus supporting its recent designation as EZ. Automated and objective delineation of band 3 will help investigations of structural biomarkers of dark-adaptation changes in aging.
关键词： age-related macular degeneration,retina,ellipsoid,segmentation,optical coherence tomography,photoreceptors,interdigitation,reflectivity,retinal pigment epithelium
更新于2025-09-23 15:23:52
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Isorhamnetin prevents H2O2?induced oxidative stress in human retinal pigment epithelial cells
摘要： Isorhamnetin, a 3-O-methylated metabolite of quercetin, exhibits antioxidant effects. However, to the best of our knowledge, no study to date has focused on the effects of isorhamnetin on retinal pigment epithelium (RPE) cells, and its underlying molecular mechanisms. Therefore, the present study aimed to examine the potential protective effect of isorhamnetin against oxidative stress in human RPE cells. The results demonstrated that pretreatment of RPE cells with isorhamnetin significantly protected cell viability against oxidative stress. In addition, isorhamnetin pretreatment inhibited hydrogen peroxide (H2O2)-induced reactive oxygen species (ROS) production and caspase-3 activation in RPE cells. Furthermore, isorhamnetin pretreatment significantly increased the phosphorylation of phosphoinositide 3-kinase (PI3K) and AKT serine/threonine kinase 1 (Akt) in RPE cells exposed to H2O2, compared with cells treated with H2O2 alone. Taken together, the present results demonstrated that isorhamnetin protected human RPE cells from oxidative stress-induced cell death, and this effect was associated with activation of the PI3K/Akt signaling pathway. Thus, isorhamnetin may be considered as a potential antioxidant useful for the prevention of age-related macular degeneration.
关键词： age-related macular degeneration,oxidative stress,isorhamnetin,retinal pigment epithelium cells
更新于2025-09-23 15:23:52
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A spectroscopic method for quick evaluation of tint strength and tint tone of titania (rutile) pigment and factors affecting them
摘要： Titanium dioxide (TiO2) manufacturing industries measure optical properties such as brightness, colour, tint strength, tint tone, gloss, scatter coefficient, and others to ensure the quality of the product. Product characterization and process control generally focus on the optical properties, which determine its quality. In this work, titania rutile pigment with varying tint strength and tint tone is analyzed and a correlation is established between particle size and the optical properties such as tint strength and tint tone. It is observed that optical properties of titania pigment depends on the particle size as well as particle size distribution. A relatively faster evaluation of tint strength and tint tone can be made using the reflectance and particle size measurements. Analytical samples were prepared by ultrasonic dispersion of pigment in water containing calgon as dispersing agent. To verify the accuracy of the method, pigment tint strength and tint tone obtained from this study are compared with those resulting from traditional analysis. The results showed that the new method is viable.
关键词： optical properties,tint strength,reflectance,titania pigment,tint tone
更新于2025-09-23 15:23:52
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Developing cysteamine-modified SERS substrate for detection of acidic pigment with weak surface affinity
摘要： In this paper, we developed cysteamine-modified surface-enhanced Raman scattering (SERS) substrate for detecting detect trace amount of acidic pigment that shows weak affinity with gold nanoparticles (Au NPs). To realize sensitive and reproducible detection of pigment with weak affinity, the SERS substrate was prepared by attaching cysteamine (CA) to the Au NPs, the acidic pigment molecule could rapidly reached to the surface of Au NPs because of the formation of multi-hydrogen-bond and electrostatic interaction between the pigment and CA molecule. The proposed method allowed us to detect five kinds of acidic pigment with a limit of 1.0 ppm, which is below the strictest safety limit. Compared with the previous methods, the advantages of the present substrate were its simple substrate preparation, high reproducibility and good universality. Furthermore, the reliable and enough accurate results had been obtained by using of the proposed substrates in the assay of trace pigment in real samples.
关键词： surface-enhanced Raman scattering,hydrogen bond interaction,cysteamine-modified,acidic pigment,weak affinity
更新于2025-09-23 15:23:52