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SUMMARY: Cellular differentiation is a highly regulated process that has vast implications for the mechanics of the cell. The interplay between differentiation induced cytoskeletal mechanical changes and strain on the nucleus is a potential cause of gene level changes. This study explores mechanical changes in SH-SY5Y neural cells during differentiation mediated by Retinoic Acid (RA) across Days 0 through 9. Findings suggest that cellular elongation increases 1.92-fold over a 10-day differentiation period, from 48.97 ±16.85µm to 93.96 ± 31.20 µm over 3 repeated trials and across multiple cells analyzed on ImageJ. Nuclear elongation increases less substantially from 17.51 ± 2.71 µm to 23.26 ± 3.10 µm over 3 repeated trials and across multiple cells. Results are statistically significant at a significance level of α = 0.05. This study is one of the first studies to show that during the process of RA mediated neural differentiation in SH-SY5Y neural cells, nuclear elongation is initially not significantly correlated with cellular elongation, but it becomes correlated during the differentiation process with an overall correlation coefficient of 0.4498 at a significance level of α = 0.05. Given the time course of the mechanical changes and the known coupling between the cytoskeleton and nuclear lamina, this study suggests a causative and correlative relationship between neurite-driven cellular elongation and nuclear elongation during neural differentiation.

Purpose: To determine whether the early assessment of temporal lobe microstructural changes using diffusion kurtosis imaging (DKI) can predict late delayed neurocognitive decline after radiotherapy in nasopharyngeal carcinoma (NPC) patients. Methods and Materials: Fifty-four NPC patients undergoing intensity-modulated radiotherapy (IMRT) participated in a prospective DKI magnetic resonance (MR) imaging study. MR imaging was acquired prior to IMRT (-0), 1 month (-1), and 3 (-3) months after IMRT. Kurtosis (Kmean, Kax, Krad) and Diffusivity (Dmean, Dax, Drad) variables in the temporal lobe gray and white matter were computed. Neurocognitive function tests (MoCA) were administered pre-radiotherapy and at 2 years post-IMRT follow-up. All the patients were divided into neurocognitive function decline (NFD group) and neurocognitive function non-decline groups (NFND group) according to whether the MoCA score declined ≥3 2 years after IMRT. All the DKI metrics were compared between the two groups, and the best imaging marker was chosen for predicting a late delayed neurocognitive decline. Results: Kurtosis (Kmean-1, Kmean-3, Kax-1, Kax-3, Krad-1, and Krad-3) and Diffusivity (Dmean-1 and Dmean-3) of white matter were significantly different between the two groups (p

This study describes the effects of chip-scale gigahertz (GHz) ultrasound (US) and electrical stimulus on the morphology, functionality, and viability of neural cells in vitro. The GHz frequency stimulation is achieved using aluminum nitride piezoelectric transducers fabricated on a silicon wafer, operating at 1.47 GHz, corresponding to the film's thickness mode resonance. These devices are used to stimulate SH-SY5Y neural cells in vitro and observe effects on the morphology and viability of the stimulated cells. It is possible to use these devices to deliver either ultrasonic stimulus alone or US stimulus in conjunction with electrical stimulus. Viability tests demonstrated that the neurons retained structural integrity and viability across a wide range of GHz US stimulus intensities (0-1.2 W/cm

Objectives: The objective of our study was to investigate whether a phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression was associated with dynamic contrast-enhanced MRI (DCE-MRI) parameters and prognosis in nasopharyngeal carcinoma (NPC).Methods: Two hundred and forty-five (245) patients with NPC who underwent pretreatment biopsy, PTEN immunohistochemistry of biopsy, and radical intensity-modulated radiation therapy (IMRT) with or without chemotherapy were included. Tumor segmentations were delineated on pretreatment MRI manually. The pharmacokinetic parameters (Ktrans, Kep, Ve, and Vp) derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Toft’s model within the tumor segmentations were estimated. The following demographics and clinical features were assessed and correlated against each other: gender, age, TNM stage, clinical-stage, Epstein-Barr virus (EBV), pathological type, progression-free survival (PFS), and prognosis status. DCE parameter evaluation and clinical feature comparison between the PTEN positive and negative groups was performed and correlation between PTEN expression with the PFS and prognosis status using Cox regression for survival analysis was assessed.Results: A significantly lower Ktrans and Kep were found in NPC tumors in PTEN negative patients than in PTEN positive patients. Ktrans performed better than Kep in detecting PTEN expression with the ROC AUC of 0.752. PTEN negative was associated with later TNM stage, later clinical-stage, shorter PFS, and worse prognosis. Moreover, N stage, pathological type, Kep, and prognostic status can be considered as independent variables in discrimination of PTEN negative expression in NPCs. Conclusions: PTEN negative indicated a shorter PFS and worse prognosis than PTEN positive in NPC patients. Ktrans and Kep derived from DCE-MRI, which yielded reliable capability, should be considered as novel image markers that are correlated with PTEN expression and may be used to predict PTEN expression noninvasively. Combined radiological and clinical features can improve the performance of the classification of PTEN expression.

The objective of our study was to investigate whether a phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression was associated with dynamic contrast-enhanced MRI (DCE-MRI) parameters and prognosis in nasopharyngeal carcinoma (NPC). Two-hundred-and-forty-five (245) patients with NPC who underwent pretreatment biopsy, expression of PTEN detected by immunohistochemistry of biopsy, and radical intensity-modulated radiation therapy (IMRT) with or without chemotherapy were included. Tumor segmentations were delineated on pretreatment MRI manually. The pharmacokinetic parameters (Ktrans, Kep, Ve, and Vp) derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Toft’s model within the tumor segmentations were estimated. The following demographics and clinical features were assessed and correlated against each other: gender, age, TNM stage, clinical-stage, Epstein–Barr virus (EBV), pathological type, progression-free survival (PFS), and prognosis status. DCE parameter evaluation and clinical feature comparison between the PTEN positive and negative groups were performed and correlation between PTEN expression with the PFS and prognosis status using Cox regression for survival analysis were assessed. A significantly lower Ktrans and Kep were found in NPC tumors in PTEN negative patients than in PTEN positive patients. Ktrans performed better than Kep in detecting PTEN expression with the ROC AUC of 0.752. PTEN negative was associated with later TNM stage, later clinical-stage, shorter PFS, and worse prognosis. Moreover, N stage, pathological type, Kep, and prognostic status can be considered as independent variables in discrimination of PTEN negative expression in NPCs. PTEN negative indicated a shorter PFS and worse prognosis than PTEN positive in NPC patients. Ktrans and Kep derived from DCE-MRI, which yielded reliable capability, may be considered as potential imaging markers that are correlated with PTEN expression and could be used to predict PTEN expression noninvasively. Combined radiological and clinical features can improve the performance of the classification of PTEN expression.

There remains a lack of understanding of the structural changes that occur across the complex, multitissue anterior cruciate ligament (ACL)-to-bone insertion as a function of aging. The objective of this study is to provide a multiscale comparison of matrix properties across the skeletally immature and mature ACL-to-bone insertion. Using complementary imaging methods, micro- and ultrastructural analysis of the insertion revealed that collagen fiber orientation at the interface changes with age, though the degree of collagen organization is maintained over time. These changes are accompanied by a decrease in collagen fibril density and are likely driven by physiological loading. Mineral crystal structure and crystallinity are conserved over time, despite regional differences in crystallinity between the interface and bone. This suggests that mineral chemistry is established early in development and underscores its important functional role. Collectively, these findings provide new insights into interface development and set critical design benchmarks for integrative soft tissue repair.

Summary Adaptive Total Field Inversion is described for quantitative susceptibility mapping (QSM) reconstruction from total field data through a spatially adaptive suppression of shadow artifacts through spatially adaptive regularization. The regularization for shadow suppression consists of penalizing low-frequency components of susceptibility in regions of small susceptibility contrasts as estimated by R2∗ derived signal intensity. Compared with a conventional local field method and two previously proposed regularized total field inversion methods, improvements were demonstrated in phantoms and subjects without and with hemorrhages. This algorithm, named TFIR, demonstrates the lowest error in numerical and gadolinium phantom datasets. In COSMOS data, TFIR performs well in matching ground truth in high-susceptibility regions. For patient data, TFIR comes close to meeting the quality of the reference local field method and outperforms other total field techniques in both clinical scores and shadow reduction.

A novel neural stimulation system is demonstrated that is capable of delivering tunable ultrasonic stimulus at the cellular level and additionally providing feedback information towards dosage regulation. GHz aluminum nitride ultrasound transducers provide continuous wave stimulation to in vitro, retinoic acid differentiated SH-SY5Y neuroblastoma cells at 1.05 GHz. Results show stimulation of optically recorded calcium ion transients in SH-SY5Y cells, with during stimulation increases in FIFo of 1.5 ± 0.328, differing from pre-stimulation with p $a$ = 0.01.

The directionality of collagen fibers across the anterior cruciate ligament (ACL) as well as the insertion of this key ligament into bone are important for understanding the mechanical integrity and functionality of this complex tissue. Quantitative analysis of three-dimensional fiber directionality is of particular interest due to the physiological, mechanical, and biological heterogeneity inherent across the ACL-to-bone junction, the behavior of the ligament under mechanical stress, and the usefulness of this information in designing tissue engineered grafts. We have developed an algorithm to characterize Optical Coherence Tomography (OCT) image volumes of the ACL. We present an automated algorithm for measuring ligamentous fiber angles, and extracting attenuation and backscattering coefficients of ligament, interface, and bone regions within mature and immature bovine ACL insertion samples. Future directions include translating this algorithm for real time processing to allow three-dimensional volumetric analysis within dynamically moving samples.