The influences of chondroitin sulfate C (C6S) on size, aggregation, sedimentation, and Zeta potential of sub-micron calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystallites with mean sizes of about 330 nm were investigated using an X-ray diffractometer, nanoparticle size Zeta potential analyzer, ultraviolet spectrophotometer, and scanning electron microscope, after which the results were compared with those of micron-grade crystals. C6S inhibited the conversion of COD to COM and the aggregation of COM and COD crystallitesis; it also decreased their sedimentation rate, thus increasing their stability in aqueous solution. The smaller the size of the COD crystallites, the easier they can be converted to COM. The stability of sub-micron COD was worse than that of micron-grade crystals. C6S can inhibit the formation of calcium oxalate stones.
Human iPSC-derived cardiomyocytes (hiPSC-CMs) exhibit functional immaturity, potentially impacting their suitability for assessing drug proarrhythmic potential. We previously devised a traveling wave (TW) system to promote maturation in 3D cardiac tissue. To align with current drug assessment paradigms (CiPA and JiCSA), necessitating a 2D monolayer cardiac tissue, we integrated the TW system with a multi-electrode array. This gave rise to a hiPSC-derived closed-loop cardiac tissue (iCT), enabling spontaneous TW initiation and swift pacing of cardiomyocytes from various cell lines. The TW-paced cardiomyocytes demonstrated heightened sarcomeric and functional maturation, exhibiting enhanced response to isoproterenol. Moreover, these cells showcased diminished sensitivity to verapamil and maintained low arrhythmia rates with ranolazine—two drugs associated with a low risk of torsades de pointes (TdP). Notably, the TW group displayed increased arrhythmia rates with high and intermediate risk TdP drugs (quinidine and pimozide), underscoring the potential utility of this system in drug assessment applications.
Abstract Background Neural stem cells (NSCs) transplantation is considered a promising treatment for Parkinson's disease. But most NSCs are differentiated into glial cells rather than neurons, and only a few of them survive after transplantation due to the inflammatory environment. Methods In this study, neural stem cells (NSCs) and microglial cells both forced with the Nurr1 gene were transplanted into the striatum of the rat model of PD. The results were evaluated through reverse transcription polymerase chain reaction (RT‐PCR), Western blot, and immunofluorescence analysis. Results The behavioral abnormalities of PD rats were improved by combined transplantation of NSCs and microglia, both forced with Nurr1 . The number of tyrosine hydroxylase+ cells in the striatum of PD rats increased, and the number of Iba1+ cells decreased compared with the other groups. Moreover, the dopamine neurons differentiated from grafted NSCs could still be detected in the striatum of PD rats after 5 months. Conclusions The results suggested that transplantation of Nurr1‐overexpressing NSCs and microglia could improve the inhospitable host brain environments, which will be a new potential strategy for the cell replacement therapy in PD.
Cells display contact guidance when cultured on topographical cues. By combining standard photolithography, nanoimprint lithography, and soft lithography, we produced sophisticated patterns on two levels, including crossing microgrooves with different depth/spacing and microgrooves with superimposed submicrometer features. The results show that for narrowly spaced microgrooves, the contact guidance is more significant to the change of groove depth than to other geometry parameters. For crossing microgrooves, the shallow grooves take over the influence on cell alignment when the deeper grooves are well separated. Finally, the superimposed submicrometer features on the groove ridges decrease the efficiency of the contact guidance of microgrooves, due to increased adhesion of cells on patterned surfaces.
High-purity cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are promising for drug development and myocardial regeneration. However, most hiPSC-derived CMs morphologically and functionally resemble immature rather than adult CMs, which could hamper their application. Here, we obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on low-thickness aligned nanofibers made of biodegradable poly(D,L-lactic-co-glycolic acid) polymer. We show that multilayered and elongated CMs could be organized at high density along aligned nanofibers in a simple one-step seeding process, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We also demonstrated the potential of CTLCs for modeling engraftments in vitro and treating myocardial infarction in vivo. Thus, we established a handy framework for cardiac tissue engineering, which holds high potential for pharmaceutical and clinical applications.
Collagen type I α-1 chain (COL1A1) is closely involved in the advancement of various tumors, yet the role of COL1A1 in the progression of glioma is not clear. Herein, we evaluated the effect of COL1A1 on glioma cell proliferation. The effect of COL1A1 on glioma cell proliferation was assessed through overexpression or knockdown of COL1A1. The CCK-8 and colony formation assays, as well as immunohistochemistry (IHC) were used to detect COL1A1 expression in different glioma grades. U-87MG as well as U-251MG cells were stably-inserted with lentivirus containing COL1A1 through transfection, we additionally used qRT-PCR as well as Western blot assay to validate their overexpression efficiencies. COL1A1 mRNA and protein levels were upregulated in the high-grade glioma (HGG) compared to the low-grade glioma (LGG). COL1A1 IHC score was remarkably higher in HGG than LGG. The staining index (SI) further showed that COL1A1 protein levels were higher in HGG than LGG. The Kaplan–Meier analysis showed that elevated COL1A1 mRNA levels were obviously correlated with lower overall survival (OS) and disease-free survival (DFS) for brain glioma patients. COL1A1 mRNA and protein levels were markedly upregulated in human glioma cell lines when compared with brain astrocyte cell lines. The high expression level of COL1A1 facilitated glioma cell proliferation. COL1A1 knockdown remarkably inhibited glioma cell proliferation. Thus, this research shows that COL1A1 promotes glioma cell proliferation and is closely related to glioma prognosis.
In this study, we has utilized electrochemically reduced graphene oxide and nafion co-modified glassy carbon electrode as a novel and sensitive electrochemical sensor for ascorbic acid in weak acid buffer solution. The modern voltammetric technique was chosen for studying the redox property of Fe(CN)63-electrochemical probe and electrochemical behavior of ascorbic acid at this modified carbon electrode surface. We have also proposed a possible mechanism to better understand how to facilitate the electron transfer between ascorbic acid and modified electrode surface. The electrochemical results have suggested that ascorbic acid exhibited a very sensitive anodic peak at about 0.3 V on as-prepared modified electrode, and its anodic peak current was enhanced about two-times more than that on the bare glassy carbon electrode. A reasonable linear relationship between the anodic peak current and the ascorbic acid concentration (0.1~100 mM) and a low detection limit of 10 μM were obtained using the prepared modified electrode. More importantly, here the proposed method can be successfully applied to the practical samples with excellent sensitivity and reproducibility.
Abstract Objectives To explore the application value of body mass index (BMI)-based kilovoltage peak (kVp) selection and contrast injection protocol combined with different adaptive statistical iterative reconstruction V (ASIR-V) strengths in renal computed tomography angiography (CTA) in reducing radiation and contrast medium (CM) doses. Methods One-hundred renal CTA patients were prospectively enrolled and were divided into individualized kVp group (group A, n = 50) and conventional 100 kVp group (group B, n = 50), both with automatic tube current modulation and CM of Iohexol at 350 mgI/mL concentration. Group A: 70 kVp, noise index (NI) of 18 and CM dose rate of 17 mgI/kg/s for 10 s for BMI <25 kg/m2 patients; 80 kVp, NI = 17, and CM dose rate of 19 mgI/kg/s for 10 s for 25 kg/m2≤BMI≤30 kg/m2 patients. Group B: 100 kVp, 50 mL of CM at the flow rate of 4.5 mL/s. The objective image quality, effective radiation dose, CM dose, injection rate, and image quality were compared between the 2 groups. Results There was no significant difference in patient characteristics between the 2 groups (P > .05). Compared to group B, group A significantly reduced effective radiation dose by 28.4%, CM dose by 27.2%, and injection rate by 22.7% (all P < .001). The 2 groups had similar SD values in erector spine (P > .05). Group A had significantly higher CT values, SNR, and CNR values of the renal arteries than group B (all P < .001). The 2 radiologists had excellent agreement (Kappa value > 0.8) in the subjective scores of renal CTA images and showed no statistically significant difference between the 2 groups (4.57 ± 0.42 vs 4.41 ± 0.49) (P > .05). Conclusions BMI-based scan and reconstruction protocol in renal CTA significantly reduces radiation and contrast doses while maintaining diagnostic image quality. Advances in knowledge (i) BMI-based individualized tube voltage selection and contrast injection protocol in renal CTA reduces both radiation and contrast doses over conventional protocol. (ii) The combination of lower kVp and higher weight ASIR-V maybe used to improve image quality in terms of contrast enhancement and image noise under lower radiation and contrast dose conditions. (iii) Renal CTA of normal size (BMI ≤ 30 kg/m2) patients acquired at low radiation dosage and low iodine contrast dose through the combination of low tube voltage and ASIR-V algorithm achieves excellent diagnostic image quality with a good inter-rater agreement.
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