Search

Bone quality parameters (BQPs) calculated from computed tomography (CT) and micro-computed tomography (μCT) images have been applied in clinical to diagnose and prevent osteoporotic fractures. However, the BQPs calculated from CT and μCT images are at different scales and incomparable due to the differences in image resolutions and accounted bone compositions. In this study, we proposed a novel method to convert HU values of CT images into the BQPs that were originally calculated using different tools. By using the standard bone composition of human bones, the BQPs of bone volume fractions (BV/TV) and volumetric bone mineral densities (vBMD) of the bones were calculated using different accounted compositions of bones and mathematical relationships defined in this study. In addition, the HU values of the bones were estimated using a parametric physical model and spectrum characteristic parameters. Relationships for converting HU values into BQPs were determined by linear fitting the calculated BQPs and estimated HU values. Cadaveric and patient studies show that the micro-scale bone volumes and macro-scale vBMDs of vertebrae calculated from CT images using the conversion relationships determined by the proposed method were close to those calculated from the μCT images and quantitative CT, respectively, with mean percent errors lower than 5%. The proposed method could be applied in clinical to accurately compute micro- and macro-scale BQPs from CT images for assessing the bone quality of patients. • Calculating bone quality parameters of varying accounted compositions at different scales. • Defining conversion relationships between bone quality parameters. • Estimating photon attenuation properties of human bones. • Accurately calculating micro-scale BV/TVs and macro-scale vBMDs of vertebrae. • Assisting accurate calculations of various bone quality parameters in clinical. [ABSTRACT FROM AUTHOR]

• Mean diffusivity (MD) was subject to anesthesia regimens. • The estimated MD was higher under isoflurane anesthesia than that under alpha-chloralose anesthesia. • Fractional anisotropy (FA) quantitation was also influenced by the anesthesia regimens. • Compared with the alpha-chloralose protocol, the isoflurane protocol resulted in the lower FA. Diffusion tensor imaging (DTI) in animal models are essential for translational neuroscience studies. A critical step in animal studies is the use of anesthetics. Understanding the influence of specific anesthesia regimes on DTI-derived parameters, such as fractional anisotropy (FA) and mean diffusivity (MD), is imperative when comparing results between animal studies using different anesthetics. Here, the quantification of FA and MD under different anesthetic regimes, alpha-chloralose and isoflurane, is discussed. We also used a range of b-values to determine whether the anesthetic effect was b-value dependent. The first group of rats (n = 6) was anesthetized with alpha-chloralose (80 mg/kg), whereas the second group of rats (n = 7) was anesthetized with isoflurane (1.5%). DTI was performed with b-values of 500, 1500, and 1500s/mm2, and the MD and FA were assessed individually. Anesthesia-specific differences in MD were apparent, as manifested by the higher estimated MD under isoflurane anesthesia than that under alpha-chloralose anesthesia (P < 0.001). MD values increased with decreasing b-value in all regions studied, and the degree of increase when rats were anesthetized with isoflurane was more pronounced than that associated with alpha-chloralose (P < 0.05). FA quantitation was also influenced by anesthesia regimens to varying extents, depending on the brain regions and b-values. In conclusion, both scanning parameters and the anesthesia regimens significantly impacted the quantification of DTI indices. [ABSTRACT FROM AUTHOR]

Purpose To measure wall shear stress (WSS) in the common carotid arteries (CCA) of a spontaneously hypertensive rat (SHR) model and a normotensive Wistar Kyoto rat (WKY) model by 2D phase-contrast magnetic resonance imaging (PC-MRI). Materials and methods PC-MRI was performed on 7 SHR and 7 WKY at ages of 4 and 7 months at a 7 T scanner. Images in the middle CCA (CCA mid ) and in the bifurcation of CCA (CCA bifur ) were acquired. The WSS values for differentiating characteristics between two models were calculated. Further, its location-specific change, regional distribution along the CCA circumference, and the reproducibility were evaluated. Results In the 4-month-old rats, SHR showed lower temporal averaged WSS (WSS avg ) and peak systolic WSS (WSS s ) in the CCA bifur in comparison with WKY (WSS avg : 0.95 ± 0.18 vs. 1.30 ± 0.36 N/m 2 ( P < 0.01); WSS s : 1.68 ± 0.70 vs. 3.22 ± 2.49 N/m 2 ( P < 0.05)). We observed the same trends in the 7-month-old rats. In the SHR model, the WSS avg was lower in the CCA bifur than in the CCA mid . The regional distribution of WSS avg along the circumference of CCA showed lower values in WKY, particularly in posterior segments of CCA bifur . The intra-observer, intra-scan and inter-scan reproducibility was acceptable and the disagreements were ranged from − 0.05 to 0.06 N/m 2 . Conclusion This study evaluated WSS in SHR and WKY models by 2D PC-MRI. High reproducibility analyses further indicated the reliability of measurements of WSS in the CCA of SHR and WKY models using PC-MRI at 7 T. [ABSTRACT FROM AUTHOR]

Gastric cancer contributes to cancer-related fatalities. Conventional chemotherapy faces challenges due to severe adverse effects, prompting recent research to focus on postbiotics, which are safer biomolecules derived from nonviable probiotics. Despite promising in vitro results, efficient in vivo delivery systems remain a challenge. This study aimed to design a potential nanoparticle (NP) formulation encapsulating the Lacticaseibacillus paracasei GMNL-133 (SGMNL-133) isolate to enhance its therapeutic efficacy in treating gastric cancer. We successfully isolated GMNL-133 (SGMNL-133) by optimizing the lysate extraction and column elution processes for L. paracasei GMNL-133, resulting in substantial enhancement of its capacity to inhibit the proliferation of gastric cancer cells. Additionally, we developed a potential NP utilizing arginine-chitosan and fucoidan encapsulating SGMNL-133. This innovative approach protected the SGMNL-133 from degradation by gastric acid, facilitated its penetration through the mucus layer, and enabled interaction with gastric cancer cells. Furthermore, in vivo experiments demonstrated that the encapsulation of SGMNL-133 in NPs significantly enhanced its efficacy in the treatment of orthotopic gastric tumors while simultaneously reducing tissue inflammation levels. Recent research highlights postbiotics as a safe alternative, but in vivo delivery remains a challenge. Our study optimized the extraction of the lysate and column elution of GMNL-133, yielding SGMNL-133. We also developed NPs to protect SGMNL-133 from gastric acid, enhance mucus penetration, and improve the interaction with gastric cancer cells. This combination significantly enhanced drug delivery and anti-gastric tumor activity. Recent research highlights postbiotics as a safer alternative, yet in vivo delivery remains a challenge. Our study optimizes lysate extraction and column elution for Lacticaseibacillus paracasei GMNL-133, yielding GMNL-133 (SGMNL-133). We've also developed nanoparticles to protect SGMNL-133 from gastric acid, enhance mucus penetration, and improve interaction with gastric cancer cells. This combination significantly enhances drug delivery and anti-gastric tumor activity. [Display omitted] [ABSTRACT FROM AUTHOR]

Diabetic patients often experience chronic inflammation and fibrosis in their cardiac tissues, highlighting the pressing need for the development of sensitive diagnostic methods for longitudinal assessment of diabetic cardiomyopathy. This study aims to evaluate the significance of an inflammatory marker known as translocator protein (TSPO) in a positron emission tomography (PET) protocol for longitudinally monitoring cardiac dysfunction in a diabetic animal model. Additionally, we compared the commonly used radiotracer, 18F-fluoro-2-deoxy- d -glucose (18F-FDG). Fourteen 7-week-old female Sprague-Dawley rats were used in this study. Longitudinal PET experiments were conducted using 18F- N -2-(2-fluoroethoxy)benzyl)- N -(4-phenoxypyridin-3-yl)acetamide (18F-FEPPA) (n = 3), the TSPO radiotracer, and 18F-FDG (n = 3), both before and after the onset of diabetes. Histological and immunohistochemical staining assays were also conducted in both the control (n = 4) and diabetes (n = 4) groups. Results indicated a significant increase in cardiac tissue uptake of 18F-FEPPA after the onset of diabetes (P < 0.05), aligning with elevated TSPO levels observed in diabetic animals according to histological data. Conversely, the uptake of 18F-FDG in cardiac tissue significantly decreased after the onset of diabetes (P < 0.05). These findings suggest that 18F-FEPPA can function as a sensitive probe for detecting chronic inflammation and fibrosis in the cardiac tissues of diabetic animals. [Display omitted] [ABSTRACT FROM AUTHOR]