Reduced water intake: Implications for rodent developmental and reproductive toxicity studies

In developmental and reproductive toxicity studies, drinking water is a common means of delivering the test agent. Reduced consumption of toxicant-containing water raises questions about indirect effects of reduced maternal fluid consumption resulting from unpalatability, versus direct effects of the test compound. Issues to consider include: objective assessment of dehydration and thirst, the relative contributions of innate and learned behaviors to drinking behavior and flavor preference, and the objective assessment of physiologic stress. Not only do lab animals under ad lib conditions consume more water than the minimum required to maintain fluid balance, animals faced with water restriction have substantial physiologic capacity for protection of metabolic processes. Measures of blood biochemistry can provide quantifiable, objective indications of fluid balance, but changes in these parameters could result from other causes such as effects of a test toxicant. Consummatory behaviors in response to perceived need are highly influenced by learning. Hence, the drinking behavior, water intake, and flavor acceptance/preference of animals used in toxicology experiments could be subject to learning experiences with the test compound. Physiological symptoms of stress produced by water deprivation may be distinguishable from the symptoms associated with other generalized stressors, such as food deprivation, but doing so may be beyond the scope of most developmental or reproductive toxicity studies. Use of concurrent controls, paired to test groups for water consumption, could help distinguish between the direct effects of a test toxicant as opposed to effects of reduced water consumption alone. Birth Defects Res (Part B), 86:157–175, 2009. ©2009 Wiley-Liss, Inc.     

Starch Phosphate Microgels for Controlled Release of Biomacromolecules

Gel-forming starch phosphates with a content of acidic phosphate groups ranging from 2.1 to 3.8 mmol/g were obtained in a phosphoric acid-urea system. The rates of starch phosphate degradation in buffer solution in the absence of amylase and in the presence of this enzyme were investigated in vitro. Starch phosphate gels were shown to be prone to enzymatic degradation. However, the rate of biodegradation decreased gradually as the content of phosphate groups increased. The use of microgels with average particle sizes in the range of 7.8–60.1 μm for the production of controlled-release preparations of interferon-alpha 2b has been demonstrated to be possible in principle.     

Growth and characterization of epithelial cells from normal human uterine ectocervix and endocervix

Summary The human uterine cervix consists of an endocervical canal lined with a single layer of columnar mucus-secreting cells and an outer ectocervix covered by a stratified squamous epithelium. We report here the culture of human endocervical epithelial cells (HEnE) and human ectocervical epithelial cells (HEcE) in serum-free medium (KGM). Both HEnE and HEcE cultures were composed of keratinocytelike cells which formed desmosomal contacts and stratified in the presence of high concentrations of calcium ions. Cells with a pleomorphic epithelial morphology were observed in HEnE cultures, but not in HEcE cultures. Keratin 18, which is characteristic of endocervix in vivo, was detected by indirect immunofluorescent staining in all HEnE cells but was never detected in cultured HEcE. HEcE expressed keratin 13 which is characteristic of ectocervix in vivo. Although keratin 13 was never detected in primary HEnE cultures, it was expressed in passaged HEnE cultures grown in medium with high concentrations of calcium and in late passage HEnE cultures. HEnE underwent an average of 15.1 population doublings during serial culture. Mean colony-forming efficiency during Passages 2 to 3 was 14.7% and mean population doubling time was 17.8 h. HEcE cultures underwent significantly more population doublings (29.0) than HEnE cultures, whereas colony-forming efficiencies and doubling times were similar to those determined for HEnE. HEnE and HEcE cells may be useful in developing in vitro models of cervical squamous metaplasia and for exploring the interactions between target cell differentiation, carcinogens, and papillomaviruses in the development of cervical neoplasia. This study was supported in part by the Rush University Committee on Research and by the Lester B. and Francis Knight and the S. Charles and Marsha Papageorge research funds.