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Recently, our group demonstrated that immobilized VEGF can capture flowing endothelial cells (ECs) from the blood in vitro and promote endothelialization and patency of acellular tissue-engineered vessels (A-TEVs) into the arterial system of an ovine animal model. Here, we demonstrate implantability of submillimeter diameter heparin and VEGF-decorated A-TEVs in a mouse model and discuss the cellular and immunologic response. At 1 mo postimplantation, the graft lumen was fully endothelialized, as shown by expression of EC markers such as CD144, eNOS, CD31, and VEGFR2. Interestingly, the same cells coexpressed leukocyte/macrophage (Mϕ) markers CD14, CD16, VEGFR1, CD38, and EGR2. Notably, there was a stark difference in the cellular makeup between grafts containing VEGF and those containing heparin alone. In VEGF-containing grafts, infiltrating monocytes (MCs) converted into anti-inflammatory M2-Mϕs, and the grafts developed well-demarcated luminal and medial layers resembling those of native arteries. In contrast, in grafts containing only heparin, MCs converted primarily into M1-Mϕs, and the endothelial and smooth muscle layers were not well defined. Our results indicate that VEGF may play an important role in regulating A-TEV patency and regeneration, possibly by regulating the inflammatory response to the implants.-Smith, R. J., Jr., Yi, T., Nasiri, B., Breuer, C. K., Andreadis, S. T. Implantation of VEGF-functionalized cell-free vascular grafts: regenerative and immunological response.

An off-the-shelf, small diameter tissue engineered vascular graft (TEVG) would be transformative to surgeons in multiple subspecialties. Herein, we report the results of a small diameter (ID ≈ 1 mm) vascular graft constructed from resorbable, amino acid-based poly(ester urea) (PEU). Electrospun PEU grafts of two different wall thicknesses (type A: 250 μm; type B: 350 μm) were implanted as abdominal infra-renal aortic grafts in a severe combined immune deficient (SCID)/beige (Bg) mouse model and evaluated for vessel remodeling over 1 year. Significantly, the small diameter TEVG does not rupture or lead to acute thrombogenic events during the intervals tested. The pilot TEVG in vivo shows long term patency and extensive tissue remodeling with type A grafts. Extensive tissue remodeling in type A grafts leads to the development of well-circumscribed neovessels with an endothelial inner lining, a neointima containing smooth muscle cells. However, due to slow degradation of the PEU scaffold materials in vivo, the grafts remain after 1 year. The type B grafts, which have 350 μm thick walls, experience occlusion over the 1 year interval due to intimal hyperplasia. This study affords significant findings that will guide the design of future generations of small diameter vascular grafts.

The equibiaxial elongational viscosity of six commercially available polymer melts is measured using a novel technique known as continuous lubricated squeezing flow. This technique is a modification of simple lubricated squeezing flow. The systems were chosen in order to investigate the dependence of equibiaxial elongational viscosity on molecular structure. Three of the melts are polyethylene with long chain branching, two are polyethylene with short chain branching, and one is polyisobutylene with linear chains. Each polymer was subjected to strain rates ranging from 0.003 to 0.1 s−1 and compared to the linear viscoelastic prediction so that the degree of strain hardening could be determined. For a modestly branched polymer, comparison of rheological behavior in both uniaxial and equibiaxial deformations was possible. POLYM. ENG. SCI., 55:1012–1017, 2015. © 2014 Society of Plastics Engineers

Nonlinear rheological properties of polyolefins have long been studied and predicted by using the Larson model with the damping function generally obtained from the stress relaxation measurements. In this study, we investigate the nonlinear rheological properties of high density polyethylene (HDPE) and polypropylene (PP) using the Larson model with damping functions obtained from either the dynamic frequency sweep or the stress relaxation test. Experimental measurements and their corresponding model predictions for the rheological parameters were then compared to evaluate the applicability of the Larson model to the nonlinear rheology, and the following conclusions could be achieved. The steady shear viscosity could be satisfactorily described by the Larson model with the damping functions obtained from the two different methods, except at shear rates higher than 103 s−1. The predicted first normal stresses also account for the measured data, except for those using the stress relaxation data showing a little deviation for the PP sample. In addition, the predictions for elongation viscosity are also in good agreement with the experimental results within the short range of elongation rate achieved in this work. POLYM. ENG. SCI., 54:2354–2361, 2014. © 2013 Society of Plastics Engineers

Chen H-L, Tsang LL-C, Concejero AM, Huang T-L, Chen T-Y, Ou H-Y, Yu C-Y, Chen C-L, Cheng Y-F. Segmental regeneration in right-lobe liver grafts in adult living donor liver transplant. Abstract: Our aim is to evaluate the relationship and impact of right-lobe (RL) liver grafts procured with or without the middle hepatic vein (MHV) trunk and MHV tributary reconstruction on segmental regeneration of these grafts in adult living donor liver transplantation (ALDLT). Patients underwent primary ALDLT using a RL liver graft were divided into three groups according to graft type: with MHV tributary reconstruction (group I), without MHV tributary reconstruction (group II), and with inclusion of the MHV trunk (group III). The overall graft volume and the volumes of the anterior and posterior segments of the grafts six months post-transplant, evaluated using computed tomography, were calculated as the regeneration indices. Optimal regeneration of the RL liver graft was achieved in the three groups of patients. There was no significant difference in the regeneration indices between groups I (149.4%) and III (143.6%). However, in group II (112.4%) without MHV or tributary reconstruction, the anterior regenerative index was lower than the other two groups and exhibited transient prolonged hyperbilirubinemia. Segmental graft regeneration is maximized by adequate venous drainage. Inclusion of the MHV trunk or MHV tributary reconstruction influences segmental liver regeneration and preclude transient hyperbilirubinemia in the early post-liver transplant phase.

Research has shown that mechanical loading affects matrix biosynthesis of intervertebral disc (IVD) cells; however the pathway(s) to this effect is currently unknown. Cellular matrix biosynthesis is an energy demanding process. The objective of this study was to investigate the effects of static and dynamic compressive loading on energy metabolism of IVD cells. Porcine annulus fibrosus (AF) and nucleus pulposus (NP) cells seeded in 2% agarose were used in this experiment. Experimental groups included 15% static compression and 0.1 and 1 Hz dynamic compression at 15% strain magnitude for 4 hours. ATP, lactate, glucose and nitric oxide (NO) contents in culture media, and ATP content in cell-agarose construct were measured using biochemical assays. While the total ATP content of AF cells was promoted by static and dynamic loading, only 1 Hz dynamic loading increased total ATP content of NP cells. Increases in lactate production and glucose consumption of AF cells suggest that ATP production via glycolysis is promoted by dynamic compression. ATP release and NO production of AF and NP cells were significantly increased by dynamic loading. Thus, this study clearly illustrates that static and dynamic compressive loading affect IVD cell energy production while cellular responses to mechanical loading were both cell type and compression type dependent.

The purpose of this study is to test whether ectopic expression of Sox-9 can induce adipose tissue-derived stem cells (ASCs) to function as real nucleus pulposus (NP) cells in vitro. Adenoviral vectors expressing Sox-9 were reported to infect the chondroblastic and human disc cells, which resulted in increased Sox-9 and type II collagen production. ASCs were isolated from rat inguinal adipose pad, characterized, and transduced in vitro with a retroviral vector encoding the Sox-9 gene. Sox-9-engineered ASCs (ASCs/Sox-9) were induced for the chondrocyte-like cell differentiation by 3D cultured in alginate beads and TGF-β3 for 2 weeks. Expression of exogenous Sox-9 protein was detected. Type II collagen and Aggrecan gene expressions of induced ASCs/Sox-9 were measured using real-time PCR; proteoglycans expressions were measured by checking the glycosaminoglycan content and type II collagen production by enzyme-linked immunosorbent assay. Isolated ASCs were CD 29(+) /CD44(+) /C-Kit(-) /Lin(-) /CD34(-) /CD45(-) . ASCs/Sox-9 expressed marked increase in exogenous Sox-9 protein. After induction, type II collagen gene expression was sevenfold higher in mRNA levels, with an approximately twofold increase in protein levels of ASCs/Sox-9 compared to ASCs. Type II collagen and proteoglycan productions were significantly increased in the ASCs/Sox-9 compared to the ASCs. In addition, co-culture of induced ASCs/Sox-9 with matured NP cells resulted in enhanced increase in proteoglycan and type II collagen production. Constitutive retroviral expression of Sox-9 could efficiently induce ASCs differentiation into chondrocyte-like cells. This novel approach may provide a practicable system for a simple and rapid differentiation of ASCs into chondrocyte-like cells which may be potentially used as a stem cell-based therapeutic tool for the treatment of degenerative disc diseases.

Understanding learners’ behaviour, perceptions and influence in terms of learner performance is crucial to predict the use of electronic learning systems. By integrating the task-technology fit (TTF) model and the theory of planned behaviour (TPB), this paper investigates the online learning utilisation of Taiwanese students. This paper provides a better understanding of individual, technological and social factors regarding online learning system performance. A total of 870 students who were earlier introduced to e-learning were surveyed after a period of exposure to the system. The results of the research model were analysed using a structural equation modelling approach to verify 10 hypotheses; support was found for eight of them. This paper offers a new perspective on the mechanisms through the TTF and TPB model constructs, which facilitates e-learning learner performance and offers important implications for understanding learner performance in online learning environments.

Benchmark dose (BMD) and the lower confidence limit on the benchmark dose (BMDL) of blood lead were estimated to explore the biologic exposure limits for renal dysfunction caused by lead. One hundred thirty-five workers from one storage battery plant were selected as lead exposure group while 143 mechanics as the control. The relationship between the blood lead concentration and the urinary excretion of total protein (TP), β2-microglobulin (β2-MG), and N-acetyl-β-D-glucosaminidase (NAG) was studied. The quantal linear logistic regression model (BMDS Version 1.3.1) was used to calculate BMD and BMDL of blood lead. The results showed that the levels of NAG, β2-MG, and TP in lead-exposed workers were higher than those of control group and elevated along with rising length of employment. The levels of three indices for renal dysfunction increased with the elevated blood lead. The BMD and BMDL of blood lead for renal dysfunction were from 299.4 to 588.7 μg/L and from 253.4 to 402.3 μg/L, respectively. The BMDL of blood lead was ranged from high to low as TP, β2-MG, and NAG. It is suggested that the urinary NAG activity could be a sensitive and early biomarker of renal tubular dysfunction induced by lead. When assessing renal function in workers occupationally exposed to lead, a blood lead level of 250 μg/L could serve as a warning signal. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 229–233, 2007.

The CPW-fed configurations of dual-mode ring resonator (DMRR) are introduced to improve the performance of the dual-mode double ring resonator (DMDRR). To obtain low insertion loss (1.65 dB at TM110 mode and 0.91 dB at TM210 mode) and high out-of-band rejection level (−51.95 dB) and wider band (BW 13.09% at TM110 and 16.14% at TM210 mode) filters, using voltage-couples and dual-mode perturbations are proposed here. Simulation results including surface current distributions and frequency responses are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1217–1221, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22397

A unique case of Wilms' tumor with monophasic epithelial histology in the bone metastasis at initial presentation in an 18-year-old Taiwanese girl is presented. Histologically, a purely differentiated epithelial component in the L1-3 vertebrae was noted, which is consistent with the epithelial component in primary Wilms' tumor of the kidney by both microscopy and immunohistochemistry. Hence, Wilms' tumor should be included in the differential diagnosis of a metastatic lesion presenting a purely epithelial histology in a young adult or a child.

Pathologic changes of the recipient native portal venous system may cause thrombosis of the portal vein, especially in pediatric living donor liver transplantation (LDLT). This study assessed the utility of Doppler ultrasound (US) for the detection of intraoperative portal vein occlusion and identification of predisposing risk factors in the recipients. Seventy-three pediatric recipients who underwent LDLT at Chang Gung Memorial Hospital, Taiwan, from 1994 to 2002 were included. Preoperative and intraoperative Doppler US evaluation of the portal vein was performed. Age, body weight, native liver disease, type of graft, graft recipient weight ratio (GRWR), type of portal anastomosis, portal velocity, portal venous size and presence of portosystemic shunt were analyzed for statistical significance of predisposing risk factors. Eight episodes of intraoperative portal vein thrombosis, with typical findings of absent Doppler flow in portal vein and prominent hepatic artery with a resistant index lower than 0.5 (p0.001), were detected during transplantation, which was then corrected by thrombectomy and re-anastomosis. Children ageor =1 yr (p = 0.025), weightor =10 kg (p = 0.024), low portal flowor =7 cm/s (p = 0.021), portal venous sizeor =4 mm (p = 0.001), and GRWR3 (p0.017) were all risk factors for intraoperative portal vein thrombosis. Doppler US is essential in the preoperative evaluation, early detection and monitoring of outcome of the portal vein in liver transplant.

We evaluated the anatomic variations of the middle right hepatic vein (MRHV) and inferior right hepatic vein (IRHV) and their clinical application to the possibility of right subtotal hepatectomy. In 400 of normal livers studied with ultrasound, the IRHV was found to drain segment 6 of the liver and flow into the inferior vena cava (IVC) in 72 (18%) cases. In 22 (5.5%) cases, the MRHV was found to drain segment 5 of the liver and flow into the IVC. The size of the IRHV ranged from 0.1 cm to 0.8 cm with an average of 0.46 cm. For the MRHV, the sizes ranged from 0.1 cm to 0.9 cm with an average of 0.34 cm. In 10/79 (12.6%) cases the IRHV and in 4/ 22 (18.1%) cases the MRHV were bigger than the right hepatic vein (RHV). The distance between the RHV and IRHV ranged from 3 cm to 5 cm with an average of 3.7 cm. The distance between the RHV and MRHV ranged from 3 cm to 3.3 cm with an average of 3.1 cm. A hyperechoic edge, similar to that of the portal vein, was observed at the wall of the hypertrophic IRHV and was 0.3 cm or larger in size. Preoperative delineation of this complex venous anatomy is very important. It provides vital information in the preoperative evaluation needed before performing a right subtotal hepatectomy with preservation of segment 6 or segment 5 of the liver, and with RHV resection. Prior to undertaking a right hepatectomy, clamping the hypertrophic MRHV and IRHV electively may minimize intra-operative blood loss and extrahepatic spread of the malignancy.

Objective Pericytes are critical cellular components of the microvasculature that play a major role in vascular development and pathologies, yet their study has been hindered by lack of a standardized method for their isolation and growth. Here we report a method for culturing human pericytes from a readily available tissue source, placenta, and provide a thorough characterization of resultant cell populations.