Recreating cellular barriers in human microphysiological systems in-vitro.

Within cellular barriers, cells are separated by basement membranes (BMs), nanometer-thick extracellular matrix layers. In existing in-vitro cellular-barrier models, cell-to-cell signaling can be preserved by culturing different cells in individual chambers separated by a semipermeable membrane. Their structure does not always replicate the BM thickness nor diffusion through it. Here, a porous polymeric nanofilm made of poly(D-L-lactic acid) (PDLLA) is proposed to recreate the BM in a microfluidic blood-brain-barrier model. Nanofilms showed an average thickness of [Formula: see text] and a maximum pore diameter of 1.6 µm. Human umbilical vein endothelial cells (HUVECs) were cultured on PDLLA. After 7 days, viability was >95% and cell morphology did not show relevant differences with HUVECs grown on control substrates. A protocol for suspending the nanofilm between 2 microfluidic chambers was identified and showed no leakage and good sealing. Clinical Relevance- Preclinical models of cellular barriers are a key step towards a deeper understanding of their roles in pathogenesis of various diseases: a physiologically relevant microfluidic model of the blood brain barrier (BBB) allows high-throughput investigations of BBB contribution in neurodegenerative diseases and cruelty-free screenings of drugs targeting the brain.

[Clinical manifestations and chest radiographic and CT findings of round pneumonia in adults].

Whereas round pneumonia in children is well known, there are few reports of this condition in adults. Chest radiographs, CT findings, clinical manifestations, and peripheral blood results in 14 cases of round pneumonia in 14 adults were evaluated. Round pneumonias ranged in size from 1 to 7 cm. Only round pneumonia was seen in 12 cases, whereas other consolidations besides round pneumonia were present in 2 cases. Eleven of 14 cases of round pneumonia were located in the lower lobes, and 8 of these 11 cases were in the superior segment of the lower lobe. Round pneumonia showed faint density in 9 cases and clear density in 5, while the margin was slightly ill-defined in 10 and well-defined in 4. No characteristic features of round pneumonia were shown on CT scan. CT showed other consolidations besides round pneumonia in 7 of 9 cases in which CT scan was carried out. Most large-sized (more than 2 cm) round pneumonias were associated with fever and elevated WBC and CRP, whereas most small (less than 2 cm) round pneumonias were associated with normal blood results and no fever. Round pneumonia in adults is not uncommon. Most round pneumonias present as slightly dense or ill-defined masses in the posterior subpleural region of the lower lobe. Round pneumonia is suggested by a history of cough, fever, elevated WBC and CRP, and a recent chest radiograph with normal findings.

Systemic arterial supply to normal basal segments of the left lung: characteristic features on chest radiography and CT.

OBJECTIVE: The purpose of this report is to present the characteristic features on chest radiography and CT of systemic arterial supply to normal basal segments of the left lung in three cases. CONCLUSION: Accurate interpretation of chest radiographs and CT scans is important in making the correct diagnosis and avoiding life-threatening lung biopsy.

The influence of materials difference on stress distribution and bone remodeling around alumina and titanium dental implants.

The long-term complications of dental implants are associated with loosening of the implant-bone interface, due to bone resorption and subsequent connective tissue interposing at the implant-bone interface. Mechanical stresses, which are induced in the surrounding bone, play a key role in the interface bone remodeling. In the present study, it is investigated how local stress patterns are associated with local bone structure. For identical geometry alumina, and titanium implants, the stress patterns, determined in the finite element models with boundary conditions, are compared with the local bone structure found in animal experiments. The results indicate that there appears to be relationship between the stress patterns and the bone remodeling at the implant-bone interface independently on the materials properties in alumina and titanium.

[Stress analysis of titanium-hydroxyapatite implant. Effect of titanium diameter on reinforcement and calculation of implant diameter].

In order to evaluate the effect of titanium diameter on reinforcement of titanium-hydroxyapatite implant and calculate the diameter of the implant under loading, stress analysis was performed using the finite element method. In finite element model, 100% or 70% of root length was supported by PMMA in place of bone and the implant was loaded 15 kgf at 45 degrees of the implant axis. The results were obtained as follows, 1. In the case of 100% support, the titanium diameter had little effect on the reinforcement of the implant, whereas in the case of 70% support, it had much effect. 2. The diameter of this implant was calculated to be more than 3.7 mm under loading. From these results and the view point of manufacturing techniques, the diameter of this implant was supposed to need 4.0 mm and that of titanium was to be 2.0 mm.

[Dynamic study of titanium-hydroxyapatite implant by finite element method].

In order to evaluate the strength of titanium-hydroxyapatite implant, adhesive tests and loading tests were performed. The results of the loading tests were compared with the computed results by finite element method. Axisymmetric 8-node quadrilateral element for arbitrary loading was used for the analysis. Implants of 3.2 mm diameter were loaded at 45 degrees of the implant axis by using an Instron testing machine at crosshead speed of 0.5 mm/min. The results were obtained as follows: 1. The mean value of the adhesive test of titanium-resin (Panavia)-hydroxyapatite was 2.3 kgf/mm2. The fracture was caused at Panavia layer. 2. The mean value of the fracture loads of implants was 10.9 kgf. The fracture was caused at Panavia layer, similarly to the result described in 1. 3. The principal stress caused at Panavia layer of the implant was approximately 2.3 kgf/mm2, which was calculated under the load of 10.9 kgf by the finite element method. This result corresponds to that of the loading test described in 1 and 2. It was ascertained by these findings that finite element method is effective for the evaluation of the strength of this implant.