Improvements in Maturity and Stability of 3D iPSC-Derived Hepatocyte-like Cell Cultures.

Induced pluripotent stem cell (iPSC) technology enables differentiation of human hepatocytes or hepatocyte-like cells (iPSC-HLCs). Advances in 3D culturing platforms enable the development of more in vivo-like liver models that recapitulate the complex liver architecture and functionality better than traditional 2D monocultures. Moreover, within the liver, non-parenchymal cells (NPCs) are critically involved in the regulation and maintenance of hepatocyte metabolic function. Thus, models combining 3D culture and co-culturing of various cell types potentially create more functional in vitro liver models than 2D monocultures. Here, we report the establishment of 3D cultures of iPSC-HLCs alone and in co-culture with human umbilical vein endothelial cells (HUVECs) and adipose tissue-derived mesenchymal stem/stromal cells (hASCs). The 3D cultures were performed as spheroids or on microfluidic chips utilizing various biomaterials. Our results show that both 3D spheroid and on-chip culture enhance the expression of mature liver marker genes and proteins compared to 2D. Among the spheroid models, we saw the best functionality in iPSC-HLC monoculture spheroids. On the contrary, in the chip system, the multilineage model outperformed the monoculture chip model. Additionally, the optical projection tomography (OPT) and electrical impedance tomography (EIT) system revealed changes in spheroid size and electrical conductivity during spheroid culture, suggesting changes in cell-cell connections. Altogether, the present study demonstrates that iPSC-HLCs can successfully be cultured in 3D as spheroids and on microfluidic chips, and co-culturing iPSC-HLCs with NPCs enhances their functionality. These 3D in vitro liver systems are promising human-derived platforms usable in various liver-related studies, specifically when using patient-specific iPSCs.

Local delivery of interleukin 7 with an oncolytic adenovirus activates tumor-infiltrating lymphocytes and causes tumor regression.

Cytokines have proven to be effective for cancer therapy, however whilst low-dose monotherapy with cytokines provides limited therapeutic benefit, high-dose treatment can lead to a number of adverse events. Interleukin 7 has shown promising results in clinical trials, but anti-cancer effect was limited, in part due to a low concentration of the cytokine within the tumor. We hypothesized that arming an oncolytic adenovirus with Interleukin 7, enabling high expression localized to the tumor microenvironment, would overcome systemic delivery issues and improve therapeutic efficacy. We evaluated the effects of Ad5/3-E2F-d24-hIL7 (TILT-517) on tumor growth, immune cell activation and cytokine profiles in the tumor microenvironment using three clinically relevant animal models and ex vivo tumor cultures. Our data showed that local treatment of tumor bearing animals with Ad5/3- E2F-d24-hIL7 significantly decreased cancer growth and increased frequency of tumor-infiltrating cells. Ad5/3-E2F-d24-hIL7 promoted notable upregulation of pro-inflammatory cytokines, and concomitant activation and migration of CD4+ and CD8 + T cells. Interleukin 7 expression within the tumor was positively correlated with increased number of cytotoxic CD4+ cells and IFNg-producing CD4+ and CD8+ cells. These findings offer an approach to overcome the current limitations of conventional IL7 therapy and could therefore be translated to the clinic.

Pedestrian self-reports of factors influencing the use of pedestrian bridges.

The study was designed to find out factors that influence use/non-use of pedestrian bridges. The use rate of five pedestrian bridges was observed in the central business district (CBD) of Ankara. After the observations, a survey was conducted among pedestrians using those bridges and crossing contrary to safe practice under them at street level (n=408). In the present data, the use rate of pedestrian bridges varied from 6 to 63%. The frequent use of the bridge when crossing the road concerned, and seeing bridge use as time saving and safe in general were positively related to respondents' bridge use. Frequent visits to CBD decreased the likelihood of using the bridge. Other factors accounted only for a small proportion of variance in bridge use. The study suggests that bridge use or non-use is a habit and not coincidental behaviour. For increasing the pedestrians' bridge use, escalators seem to be a good solution, but traffic signals under a bridge may deteriorate the use rate. In addition, increasing the number of legs leading to the bridge may not increase the use rate. The use rate is likely to improve, if the safety benefits and convenience of using the bridge without considerable time loss are clearly visible to pedestrians.

Effects of a rumble strip barrier line on lane keeping in a curve.

This field study was conducted along a curve where the barrier line was worn out due to encroachments by cars. Vehicles were unobtrusively video recorded with the worn barrier line, after re-painting the barrier line and after milling the rumble strip barrier line. Lateral positions and speeds of vehicles were measured. Vehicle type and traffic situation were also classified (n = 6599). It was assumed that if encroachments of barrier line and the standard deviation of lateral positions were reduced, safety would improve. The standard deviation of the lateral position of passenger cars travelling in free-flow traffic decreased from 35 cm with the worn barrier line to 28 cm after re-painting the barrier line and to 24 cm after milling the rumble strip barrier line. The mean speeds of cars in free-flow traffic did not change. No vehicle with oncoming traffic crossed the barrier line after rumble strip. Encroachments of passenger cars in free-flow traffic with no oncoming traffic fell from 9.2% to 2.5% after re-painting, with no further change after implementing the rumble strip. The improvement in visual guidance alone reduced the number of crossings. However, including rumble strips may reduce the need for frequent re-painting of barriers.

Can social psychological models be used to promote bicycle helmet use among teenagers? A comparison of the Health Belief Model, Theory of Planned Behavior and the Locus of Control.

PROBLEM: The bicycle helmet use rate is still low among teenagers despite the cumulating evidence that bicycle helmets can prevent cyclists from serious injuries and death. The objective of this study was to investigate the usefulness of the Health Belief Model (HBM; Health Education Monographs, 2 (1974) (1), Theory of Planned Behavior (TPB; Ajzen, I. (1988). Attitudes, personality and behavior. Open University Press, Milton Keynes) and Locus of Control model (LC; Psychological Monographs, (1966) (80) in understanding the intention to use bicycle helmet use among bicycle helmet owners. METHOD: Data were collected at two schools in Helsinki, Finland. Students (N=965) completed a questionnaire including three social psychological models applied to helmet use. Models were compared by structural equation modeling techniques. SUMMARY: Results showed that the TPB and LC model fitted the data well, whereas fit of the HBM model was lower than the fit of TPB and LC models. All components of TPB and external LC orientation were significantly related to the intention to use a helmet. TPB together with LC model provide a promising theoretical framework for helmet use promotion campaigns. Practical suggestions for future bicycle helmet campaigns were provided.