Visualization and Quantification of 3D Tumor Cell Migration under Extracellular Stimulation.

To investigate tumor cell migration capability, the scratch/wound healing assay and the Transwell assay are the most commonly used assays in the current biomedical research laboratory. However, both assays have their limitations and may mislead the interpretation of the results. In the current study, visualization and quantification of tumor cell migration process was realized in a three-dimensional (3D) environment. The tumor cells horizontally migrated along a Matrigel-filled microchannel under extracellular stimulation. The cell migration process was visualized under a microscope, and the migration speed could be calculated based on the traveling distance of the cells and the time required. Here, three demonstrations were conducted, respectively, including cells attracted by nutrient gradient, stimulated by cytokine, and coculturing with fibroblasts. The results revealed that the cell migration capability could be visually and quantitatively correlated to the extracellular stimulation. The current protocol is compatible to the existing laboratory setup and provides a persuasive result for the study of the 3D cell migration process. Understanding of the molecular and intercellular mechanism of cancer metastasis can potentially develop effective therapeutic strategy.

Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography.

Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.

A Taiwanese Mandarin Main Concept Analysis (TM-MCA) for quantification of aphasic oral discourse.

BACKGROUND: Various quantitative systems have been proposed to examine aphasic oral narratives in English. A clinical tool for assessing discourse produced by Cantonese-speaking persons with aphasia (PWA), namely Main Concept Analysis (MCA), was developed recently for quantifying the presence, accuracy and completeness of a narrative. Similar tools for Mandarin speakers are currently absent. AIMS: The first aim is to develop and establish the validity of the Taiwanese Mandarin Main Concept Analysis (TM-MCA) for the Mandarin-speaking population in Taiwan, given the paucity of related investigations. Another aim is to establish the influence of age and education level on Taiwanese Mandarin speakers' oral narrative abilities. The third purpose is to examine how well the TM-MCA could distinguish between native speakers with and without aphasia in Taiwan. The final aim is to examine the reliability and validity of the TM-MCA. METHODS & PROCEDURES: Eight speech-language pathologists (SLPs) and eight neurologically intact participants were involved to establish the TM-MCA main concepts. Another 36 neurologically intact participants and 10 PWA participated to validate the TM-MCA by contrasting their performance. OUTCOMES & RESULTS: Both age and educational level affected the oral discourse performance among the neurologically intact adults. Significant differences on the TM-MCA measures were noted between the control group and the group with aphasia. Moreover, the degree of aphasia significantly affected the oral discourse of PWA. CONCLUSIONS & IMPLICATIONS: The TM-MCA is a culturally appropriate quantitative system for the Taiwanese Mandarin population. It can be used to supplement standardized aphasia tests to help SLPs make more informative decisions not only on clinical diagnosis but also on treatment planning.

The life cycle of the policy for preventing road accidents: an empirical example of the policy for reducing drunk driving crashes in Taipei.

The purpose of this paper is to examine the temporal variation of the effect of preventive policy on reducing traffic accidents. The life cycle theory was introduced to describe the safety effect of the intervening policy over time. Poisson regression models with dummy-based and time-based specifications were used to evaluate the effect of an intervening policy over an observation period following its implementation. The policy of "Criminal sanction for drunk driving (CSFDD)" in Taipei city was evaluated as an empirical example to determine whether the temporal variation of safety effect happened to the CSFDD policy. The study results showed that alcohol consumption, arresting the drunk driving offenders, and the implementation of the CSFDD were the significant factors affecting the rate of occurrence of fatal accidents involving drunk driving. The effect of the CSFDD policy appeared to be a rapid initial response followed by a lower rate of decay. The existence of the life cycle implies that employing different observation periods following the implementation of a specific policy to evaluate its performance may obtain different effects. The results of this study are crucial for policy evaluation. The effects of safety policy should be carefully interpreted in order to avoid misleading the relevant authorities in coming to the wrong conclusions and as such make the wrong decisions.