Bioinformatics education in high school: implications for promoting science, technology, engineering, and mathematics careers.

We investigated the effects of our Bio-ITEST teacher professional development model and bioinformatics curricula on cognitive traits (awareness, engagement, self-efficacy, and relevance) in high school teachers and students that are known to accompany a developing interest in science, technology, engineering, and mathematics (STEM) careers. The program included best practices in adult education and diverse resources to empower teachers to integrate STEM career information into their classrooms. The introductory unit, Using Bioinformatics: Genetic Testing, uses bioinformatics to teach basic concepts in genetics and molecular biology, and the advanced unit, Using Bioinformatics: Genetic Research, utilizes bioinformatics to study evolution and support student research with DNA barcoding. Pre-post surveys demonstrated significant growth (n = 24) among teachers in their preparation to teach the curricula and infuse career awareness into their classes, and these gains were sustained through the end of the academic year. Introductory unit students (n = 289) showed significant gains in awareness, relevance, and self-efficacy. While these students did not show significant gains in engagement, advanced unit students (n = 41) showed gains in all four cognitive areas. Lessons learned during Bio-ITEST are explored in the context of recommendations for other programs that wish to increase student interest in STEM careers.

Activated notch supports development of cytokine producing NK cells which are hyporesponsive and fail to acquire NK cell effector functions.

Natural Killer (NK) cells are powerful effectors of cytotoxicity against "stressed" cells. They also produce cytokines and chemokines to activate the adaptive immune response. Understanding NK cell development and maturation may have implications for cancer therapy and for immunity against infections. We hypothesized that Notch signaling, critical for hematopoesis, would be involved in NK cell development. The role of constitutively activated Notch1 (ICN) on NK cell maturation was studied using human umbilical cord blood (UCB) progenitors cultured on a murine embryonic liver stroma cell line (EL08-1D2) and human cytokines. UCB CD34(+)/ICN(+) sorted cells resulted in a population of CD7(+) early lymphoid precursors and subsequent NK lineage commitment independent of stroma or IL-15. Early expression of L-selectin on ICN(+) precursors suggested their homing competence. These precursors further committed to the NK lineage, and were capable of producing cytokines and chemokines such as interleukin (IL)-13, granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha), yet poorly acquired NK inhibitory receptors and cytotoxic effector function. In the presence of stroma, ICN(+) precursors also gave rise to a population of early T lineage committed cells characterized by expression of cytoplasmic CD3 gamma, epsilon, and delta chains, RAG1/2, and production of IL-2, suggesting bona fide Th1 commitment. Importantly, signals from EL08-1D2 stroma were required for this development process. In conclusion, sustained Notch signaling can replace stroma in differentiation of a common CD7(+) lymphoid precursor from UCB CD34(+) progenitors and induce NK cell commitment. However, these NK cells are immature in their cytokine production profile, are hyporesponsive, and poorly acquire NK cell receptors involved in self-tolerance and effector function.

Imaging of murine liver tumor using microCT with a hepatocyte-selective contrast agent: accuracy is dependent on adequate contrast enhancement.

INTRODUCTION: A major limitation in using both spontaneous and implanted murine liver tumor models in cancer research is the inability to accurately detect and monitor tumor volume. Because microCT without contrast enhancement cannot accurately distinguish tumor from normal liver, we sought to determine the accuracy of contrast enhanced microCT for monitoring liver tumors in mice, performed with intravenous (i.v.) injection of ITG, a hepatocyte-selective contrast agent. METHODS: Twelve female BALB/c mice were injected with 5 x 10(5) CT26 tumor cells in two sites in the liver on day 0, resulting in 24 liver tumors. On days 3, 5, 7, and 10, three mice per day were injected with ITG (0.1 mL ITG/10 g body weight) by tail vein, followed 4 hours later by imaging with microCT (ImTek, Inc.). ITG is transported selectively to hepatocytes by an apoE receptor-mediated process that results in opacification of normal liver parenchyma after i.v. injection. Contrast enhancement on CT scans was graded as good, fair, or poor. After imaging, mice were euthanized to perform gross and histopathologic correlation of liver tumors with CT images. RESULTS: The mean tumor size on microCT and at histopathologic evaluation was 2.2 and 2.3 mm, respectively (P > 0.05). Regression analysis showed no difference between the CT-measured tumor and the actual tumor size (P > 0.05). The overall accuracy for detection of tumor on microCT was 88%, with one false-positive and two false-negative readings. All three erroneous readings on CT scan occurred in mice in which the contrast enhancement of the liver was poor due to inadequate i.v. injection. Although the overall sensitivity and specificity was 90% and 75%, respectively, this was highly dependent on the degree of contrast enhancement. CONCLUSIONS: MicroCT with ITG contrast is an excellent means to monitor tumor diameter in murine hepatic tumor models. However, adequate contrast enhancement is critical for accurate imaging.