A biomimetic orthogonal-bilayer tubular scaffold for the co-culture of endothelial cells and smooth muscle cells.

In blood vessels, endothelial cells (ECs) grow along the direction of blood flow, while smooth muscle cells (SMCs) grow circumferentially along the vessel wall. To mimic this structure, a polycaprolactone (PCL) tubular scaffold with orthogonally oriented bilayer nanofibers was prepared via electrospinning and winding. ECs were cultured on the inner layer of the scaffold with axial nanofibers and SMCs were cultured on the outer layer of the scaffold with circumferential nanofibers. Fluorescence images of the F-actin distribution of ECs and SMCs indicated that cells adhered, stretched, and proliferated in an oriented manner on the scaffold. Moreover, layers of ECs and SMCs formed on the scaffold after one month of incubation. The expression levels of platelet-endothelial cell adhesion molecule 1 (PECAM-1) and a contractile SMC phenotype marker in the EC/SMC co-culture system were much higher than those in individual culture systems, thus demonstrating that the proposed biomimetic scaffold promoted the intercellular junction of ECs and preserved the contractile phenotype of SMCs.

EIT Imaging of Intracranial Hemorrhage in Rabbit Models Is Influenced by the Intactness of Cranium.

Electrical impedance tomography (EIT) has been shown to be a promising, bedside imaging method to monitor the progression of intracranial hemorrhage (ICH). However, the observed impedance changes within brain related to ICH differed among groups, and we hypothesized that the cranium intactness (open or closed) may be the one of potential reasons leading to the difference. Therefore, the aim of this study was to investigate this effect of open or closed cranium on impedance changes within brain in the rabbit ICH model. In this study, we first established the ICH model in 12 rabbits with the open cranium and in 12 rabbits with the closed cranium. Simultaneously, EIT measurements on the rabbits' heads were performed to record the impedance changes caused by injecting the autologous nonheparinized blood into cerebral parenchyma. Finally, the regional impedance changes on EIT images and the whole impedance changes were analyzed. It was surprisingly found that when the cranium was open, the impedance of the area where the blood was injected, as well as the whole brain impedance, decreased with the amount of blood being injected; when the cranium was closed, while the impedance of the area where blood was not injected continued to increase, the impedance of the area where blood was injected decreased within 20s of the blood being injected and then remained almost unchanged, and the whole brain impedance had a small fall and then notably increased. The results have validated that the cranium completeness (open or closed) has influences on impedance changes within brain when using EIT to monitor ICH. In future study on application of EIT to monitor ICH, the cranium completeness should be taken into account for establishing an ICH model and analyzing the corresponding EIT results.

Use of electrical impedance tomography to monitor regional cerebral edema during clinical dehydration treatment.

OBJECTIVE: Variations of conductive fluid content in brain tissue (e.g. cerebral edema) change tissue impedance and can potentially be measured by Electrical Impedance Tomography (EIT), an emerging medical imaging technique. The objective of this work is to establish the feasibility of using EIT as an imaging tool for monitoring brain fluid content. DESIGN: a prospective study. SETTING: In this study EIT was used, for the first time, to monitor variations in cerebral fluid content in a clinical model with patients undergoing clinical dehydration treatment. The EIT system was developed in house and its imaging sensitivity and spatial resolution were evaluated on a saline-filled tank. PATIENTS: 23 patients with brain edema. INTERVENTIONS: The patients were continuously imaged by EIT for two hours after initiation of dehydration treatment using 0.5 g/kg intravenous infusion of mannitol for 20 minutes. MEASUREMENT AND MAIN RESULTS: Overall impedance across the brain increased significantly before and after mannitol dehydration treatment (p = 0.0027). Of the all 23 patients, 14 showed high-level impedance increase and maintained this around 4 hours after the dehydration treatment whereas the other 9 also showed great impedance gain during the treatment but it gradually decreased after the treatment. Further analysis of the regions of interest in the EIT images revealed that diseased regions, identified on corresponding CT images, showed significantly less impedance changes than normal regions during the monitoring period, indicating variations in different patients' responses to such treatment. CONCLUSIONS: EIT shows potential promise as an imaging tool for real-time and non-invasive monitoring of brain edema patients.

MicroRNA-320 inhibits osteosarcoma cells proliferation by directly targeting fatty acid synthase.

Increasing evidence has demonstrated that small noncoding microRNAs (miRNAs) could contribute to cancer development and progression. Besides, they are differentially expressed in human tumor tissues. In the current study, we found that miR-320 was significantly downregulated in human osteosarcoma tissues, compared with adjacent normal tissues. Introduction of miR-320 mimics into U2OS and MG63 cells inhibited cell proliferation, while cell apoptosis rate remained unaltered. Additionally, miR-320 overexpression could also suppress tumor growth in the nude mice. At the molecular level, our results further revealed that the expression of fatty acid synthase (FASN), a key enzyme for de novo biosynthesis of fatty acids, was negatively regulated by miR-320. Therefore, our results suggest that miR-320 may act as a tumor suppressor for osteosarcoma.

A new head phantom with realistic shape and spatially varying skull resistivity distribution.

Brain electrical impedance tomography (EIT) is an emerging method for monitoring brain injuries. To effectively evaluate brain EIT systems and reconstruction algorithms, we have developed a novel head phantom that features realistic anatomy and spatially varying skull resistivity. The head phantom was created with three layers, representing scalp, skull, and brain tissues. The fabrication process entailed 3-D printing of the anatomical geometry for mold creation followed by casting to ensure high geometrical precision and accuracy of the resistivity distribution. We evaluated the accuracy and stability of the phantom. Results showed that the head phantom achieved high geometric accuracy, accurate skull resistivity values, and good stability over time and in the frequency domain. Experimental impedance reconstructions performed using the head phantom and computer simulations were found to be consistent for the same perturbation object. In conclusion, this new phantom could provide a more accurate test platform for brain EIT research.

A comparative proteomic study identified calreticulin and prohibitin up-regulated in adrenocortical carcinomas.

BACKGROUND: Identifying novel tumor biomarkers to develop more effective diagnostic and therapeutic strategies for patients with ACC is urgently needed. The aim of the study was to compare the proteomic profiles between adrenocortical carcinomas (ACC) and normal adrenocortical tissues in order to identify novel potential biomarkers for ACC. METHODS: The protein samples from 12 ACC tissues and their paired adjacent normal adrenocortical tissues were profiled with two-dimensional electrophoresis; and differentially expressed proteins were identified by mass spectrometry. Expression patterns of three differently expressed proteins calreticulin, prohibitin and HSP60 in ACC, adrenocortical adenomas (ACA) and normal adrenocortical tissues were further validated by immunohistochemistry. RESULTS: In our proteomic study, we identified 20 up-regulated and 9 down-regulated proteins in ACC tissues compared with paired normal controls. Most of the up-regulated proteins were focused in protein binding and oxidoreductase activity in Gene Ontology (GO) molecular function classification. By immunohistochemistry, two biomarkers calreticulin and prohibitin were validated to be overexpressed in ACC compared with adrenocortical adenomas (ACA) and normal tissues, but also calreticulin overexpression was significantly associated with tumor stages of ACC. CONCLUSION: For the first time, calreticulin and prohibitin were identified to be novel candidate biomarkers for ACC, and their roles during ACC carcinogenesis and clinical significance deserves further investigation. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1897372598927465.

[The study of the relationship between microlymphatic vessel density and lymph metastasis in hepatocellular carcinoma].

Not Abstract.

Self-organization of hydroxyapatite nanorods through oriented attachment.

The oriented attachment of hydroxyapatite (HAP) nanorods was achieved through a hydrothermal treatment. The nanorods were arranged in order along the c-axis of the HAP. These formed ca. 3.5 slip-shaped pores between the rods. High-resolution transmission electron (HRTEM) also revealed that single crystals of HAP may grow in the [0 0 2] direction of the HAP structure. This work extends the understanding of the potential for using biomimetic principles to synthesize bone-like composite materials.

[A simulation study of electrical impedance scan-imaging based on a phantom].

OBJECTIVE: To testify the feasibility of electrical impedance scanning (EIS) imaging and to classify the factors influencing EIS imaging at the early stage of electrical impedance scanning breast imaging study. METHOD: Based on the EIS experiment workplace, a phantom to simulate the distribution of breast tissue was designed. Using NaCl solution and agar block with different conductance, three kinds of electric fields disturbances were simulated. RESULT: Different electric fields disturbance induced by different conductance distributions bring different imaging effects. CONCLUSION: The imaging based on the theory of EIS is feasible. Initiative factors influencing EIS imaging are confirmed.

Induced current electrical impedance tomography system: experimental results and numerical simulations.

In electrical impedance tomography (EIT), measurements of developed surface potentials due to applied currents are used for the reconstruction of the conductivity distribution. Practical implementation of EIT systems is known to be problematic due to the high sensitivity to noise of such systems, leading to a poor imaging quality. In the present study, the performance of an induced current EIT (ICEIT) system, where eddy current is applied using magnetic induction, was studied by comparing the voltage measurements to simulated data, and examining the imaging quality with respect to simulated reconstructions for several phantom configurations. A 3-coil, 32-electrode ICEIT system was built, and an iterative modified Newton-Raphson algorithm was developed for the solution of the inverse problem. The RMS norm between the simulated and the experimental voltages was found to be 0.08 +/- 0.05 mV (<3%). Two regularization methods were implemented and compared: the Marquardt regularization and the Laplacian regularization (a bounded second-derivative regularization). While the Laplacian regularization method was found to be preferred for simulated data, it resulted in distinctive spatial artifacts for measured data. The experimental reconstructed images were found to be indicative of the angular positioning of the conductivity perturbations, though the radial sensitivity was low, especially when using the Marquardt regularization method.