Erik S. Wallen

The Function of Annotations in the Comprehension of Scientific Texts: Cognitive Load Effects and the Impact of Verbal Ability

Students participated in a study (n=98) investigating the effectiveness of three types of annotations on three learning outcome measures. The annotations were designed to support the cognitive processes in the comprehension of scientific texts, with a function to aid either the process of selecting relevant information, organizing the information in memory, or integrating information with prior knowledge. Learning outcomes were measured by assessing student recall of facts, comprehension of the text, and mental model construction. Results show that different types of annotations facilitate different learning outcomes. In addition, we found that, compared to having only one type of annotation available, multiple types of annotations resulted in a higher cognitive load that resulted in lower performance, especially in tests of higher-level processing. This effect was stronger for low-verbal-ability learners, who showed lower peformance in treatments with multiple types of annotations than high-verbal-ability learners.

Effects of combined treatment of chemotherapeutics and hyperthermia on survival and the regulation of heat shock proteins in dunning R3327 prostate carcinoma cells

Hyperthermia can enhance the clinical response of chemotherapeutic agents in prostate cancer, but optimal sequencing of this combination therapy needs to be developed. Given the role of heat shock proteins (HSPs) in the development of resistance (thermotolerance) to subsequent hyperthermic stresses as well as to certain chemotherapeutics, the study of HSP regulation is important in the establishment of effective schedules in multimodal treatment strategies.

Heat Shock Protein (HSP72) Surface Expression Enhances the Lysis of a Human Renal Cell Carcinoma by IL-2 Stimulated NK Cells

Patients with advanced renal cell carcinoma (RCC) have a poor prognosis due to the failure of this tumor entity to respond to conventional therapeutic approaches such as irradiation or chemotherapy. Since the introduction of interleukin-2 based immunotherapy by Rosenberg et al. there has been some clinical progress in the treatment of metastatic RCC [1].

Heat shock protein 70 and glycoprotein 96 are differentially expressed on the surface of malignant and nonmalignant breast cells

Abstract Heat shock proteins (HSPs), which are important for a number of different intracellular functions, are occasionally found on the surface of cells. The function of heat shock protein on the cell surface is not understood, although it has been shown to be greater in some tumor cells and some virally infected cells. Surface expression of both glycoprotein 96 (gp96) and Hsp70 occurs on tumor cells, and this expression correlates with natural killer cell killing of the cells. We examined the surface expression of gp96 and Hsp70 on human breast cell lines MCF7, MCF10A, AU565, and HS578, and in primary human mammary epithelial cells by immunofluorescence microscopy and flow cytometry. The nonmalignant cell lines HS578, MCF10A, and HMEC showed no surface expression of gp96, whereas malignant cell lines MCF7 and AU565 were positive for gp96 surface expression. All of the breast cell lines examined showed Hsp70 surface expression. These results also confirm previous studies, demonstrating that Hsp70 is on the plasma membrane of tumor cell lines. Given the involvement of heat shock proteins, gp96 and Hsp70, in innate and adaptive immunity, these observations may be important in the immune response to tumor cells.

A computer program to aid in visual concept development in dentistry

Beginning dental students normally receive their first exposure to the study of tooth forms (morphology) through a dental anatomy laboratory course in which they are required to reproduce tooth morphology, usually with wax. The fabrication of a tooth in wax requires proper visual recognition skills and fine eye-hand coordination. Many students struggle with one or both of these. A computer program, designed to teach recognition concepts, was delivered to three groups of beginning freshman dental students in conjunction with their dental anatomy laboratory course while a group of their classmates served as the controls. This study investigated (1) instructional design and interface improvement and (2) the best method to implement the computer program. Experimental and control groups all received normal daily critiques of their course project work. After completion of the computer program, all groups were tested with a recognition-based examination as well as with a practical examination, requiring the reproduction of a tooth in wax. All experimental groups scored better than the control group on both examinations. Results indicated that computer-based instruction may be a useful means to foster visual concept development. An expanded program, using better graphics, animation and movies is currently under development.

β-Galactosidase as a marker of HSP70 promoter induction in Dunning R3327 prostate carcinoma cells

Hyperthermia is known to improve the response of tumors to radiation or chemotherapeutic treatment when combined in multimodal strategies. The cellular response to hyperthermia is associated with the synthesis of heat shock proteins (HSP). To study the stress response in prostate cancer we have developed a clone of Dunning R3327 rat prostate carcinoma cells stably transfected with a gene construct containing theE. coli β-galactosidase gene driven by theDrosophila HSP70 promoter. The measurement of β-galactosidase serves as a rapid and semiquantitative assay of HSP70 gene activation. The Dunning cell clone showed evidence of incorporation of the HSP70/β-galactosidase construct within the genomic DNA by Southern blot analysis. When compared to mock-transfected control cells, the clone showed minimal baseline β-galactosidase activity, which significantly increased following a hyperthermic stress. The time course of β-galactosidase elevation following heat stress paralleled the time course of cellular HSP70 elevation by Western blot analysis. These stably transfected Dunning R3327 cells may provide a useful tool to study the effects of hyperthermia, radiation, and chemotherapeutic agents on the cellular stress response and in the establishment of HSP70 as a marker of cellular resistance in the multimodal treatment of prostate cancer.

Repression of thermotolerance in Dunning R3327 prostate carcinoma cells by 2-deoxy-glucose

The transient addition of the cytosolic energy depletor 2-deoxy-glucose to cultures of rat prostate carcinoma cells blunted the induction of Hsp70 protein following exposure to elevated temperatures in a manner that appeared to parallel its effects on energy metabolism. While the reduction in stress-induced heat-shock protein expression by treatment with 2-deoxy-glucose had no effects on the acute loss of cellular viability after exposure to heat, the acquisition of thermotolerance in response to a conditioning stimulus was specifically repressed. Therefore, 2-deoxy-glucose will be a useful tool in the investigation of mechanisms that mediate immediate versus chronic responses to cellular stress, including the specific roles played by members of the heat-shock protein family of proteins. These results might have important implications in the design of protocols for the hyperthermic treatment of tumours.