Biomedical subjects

Adam Rosenthal

Publications and source records attributed to Adam Rosenthal.

4 recordsLinked to original sources

PubMed2006

Quantitative modeling of dielectrophoretic traps.

We present quantitative modeling software for simulating multiple forces acting on a single particle in a microsystem. In this paper, we focus on dielectrophoretic (DEP) trapping of single cells against fluid flow. The software effectively models the trapping behavior for a range of particles including beads, mammalian cells, viruses, and bacteria. In addition, the software can be used to reveal useful information about the DEP traps - such as multipolar DEP force effects, trap size-selectivity, and effects from varying the flow chamber height. Our modeling software thus serves as a predictive tool, enabling the design of novel DEP traps with superior performance over existing trap geometries. In addition, the software can evaluate a range of trap dimensions to determine the effects on trapping behavior, thus optimizing the trap geometry before it is even fabricated. The software is freely available to the scientific community at: .

Computer Simulation↗

PubMed2005

Familial ovarian cancer screening.

Familial predisposition accounts for approximately 10% of epithelial ovarian cancer. Identification and management of at-risk families is therefore an important area that bridges gynaecological and clinical genetic practice. The efficacy of screening for ovarian cancer in both high- and low-risk populations is currently of unproven benefit and is associated with some risks related to false-positive results. In contrast to the general population, preventive surgery is a realistic proposition for many women at high-risk. Although prophylactic bilateral salpingo-oophorectomy prevents ovarian and tubal cancer and reduces the risk of breast cancer, this option is unsuitable for women who have yet to complete their families or who are unwilling to undergo surgery. There is therefore a continued demand for screening in the high-risk population. This chapter discusses the limitations of screening, the circumstances under which screening is appropriate and current screening guidelines. Ongoing and future research that should help to provide additional information about this area is also reviewed.

Adult↗

PubMed2005

Differential regulation of beta-defensin expression in human skin by microbial stimuli.

In response to infection, epithelia mount an innate immune response that includes the production of antimicrobial peptides. However, the pathways that connect infection and inflammation with the induction of antimicrobial peptides in epithelia are not understood. We analyzed the molecular links between infection and the expression of three antimicrobial peptides of the beta-defensin family, human beta-defensin (hBD)-1, hBD-2, and hBD-3 in the human epidermis. After exposure to microbe-derived molecules, both monocytes and lymphocytes stimulated the epidermal expression of hBD-1, hBD-2, and hBD-3. The induced expression of hBD-3 was mediated by transactivation of the epidermal growth factor receptor. The mechanisms of induction of hBD-1 and hBD-3 were distinct from each other and from the IL-1-dependent induction of hBD-2 expression. Thus during inflammation, epidermal expression of beta-defensins is mediated by at least three different mechanisms.

Bacterial Toxins↗

PubMed2004

Dielectrophoretic traps for single-particle patterning.

We present a novel microfabricated dielectrophoretic trap designed to pattern large arrays of single cells. Because flowing away untrapped cells is often the rate-limiting step during cell patterning, we designed the trap to be strong enough to hold particles against practical flow rates. We experimentally validated the trap strength by measuring the maximum flow rate that polystyrene beads could withstand while remaining trapped. These bead experiments have shown excellent agreement with our model predictions, without the use of fitting parameters. The model was able to provide us with a fundamental understanding of how the traps work, and additionally allowed us to establish a set of design rules for optimizing the traps for a wide range of cell sizes. We provide the foundations for an enabling technology that can be used to pattern cells in unique ways, allowing us to do novel cell biology experiments at the microscale.

Cell Culture Techniques↗