Transepithelial electrical resistance (TEER): a functional parameter to monitor the quality of oviduct epithelial cells cultured on filter supports

Cultivation of oviduct epithelial cells on porous filters fosters in vivo-like morphology and functionality. However, due to the optical properties of the filter materials and the cells’ columnar shape, cell quality is hard to assess via light microscopy. In this study, we aim to evaluate transepithelial electrical resistance (TEER) measurement as a prognostic quality indicator for the cultivation of porcine oviduct epithelial cells (POEC). POEC were maintained in four different types of media for 3 and 6 w to achieve diverse culture qualities, and TEER was measured before processing samples for histology. Culture quality was scored using morphological criteria (presence of cilia, confluence and cell polarity). We furthermore analyzed the correlation between cellular height (as a measure of apical–basal polarization) and TEER in fully differentiated routine cultures (biological variation) and in cultures with altered cellular height due to hormonal stimulation. Fully differentiated cultures possessed a moderate TEER between 500 and 1100 Ω*cm2. Only 5 % of cultures which exhibited TEER values in this defined range had poor quality. Sub-differentiated cultures showed either very low or excessively high TEER. We unveiled a highly significant (P < 0.0001) negative linear correlation between TEER and epithelial height in well-differentiated cultures (both routine and hormone stimulated group). This may point toward the interaction between tight junction assembly and epithelial apical–basal polarization. In conclusion, TEER is a straightforward quality indicator which could be routinely used to monitor the differentiation status of oviduct epithelial cells in vitro

Long-term culture of primary porcine oviduct epithelial cells: Validation of a comprehensive in vitro model for reproductive science

Recently, we established a protocol for the cultivation of primary porcine oviduct epithelial cells (POEC), which promoted tissue-like morphology for a prolonged culture period. The present study focuses on developing this model into a comprehensive, standardized culture system, as a candidate tool for reproductive toxicity testing and basic research. We cultivated POEC isolated from 25 animals in our culture system for both 3 and 6 weeks and systematically analyzed effects of medium conditioning, supplementation with standardized sera, and culture duration in both freshly isolated and cryopreserved cells. The differentiation status was evaluated via histomorphometry, transepithelial electrical resistance (TEER) measurement, and expression analyses. The culture system possessed high reproducibility, more than 95% of cultures achieved a fully differentiated phenotype. Cells recapitulated in vivo–like morphology and ultrastructure from 3 to 6 weeks. Cryopreservation of the cells prior to cultivation did not affect culture quality of POEC. Employment of conditioned medium ensured optimal promotion of POEC differentiation, and different standardized sera induced fully differentiated phenotypes. Consistent TEER establishment indicated the presence and maintenance of cell type–specific intercellular junctions. The functionality of POEC was proven by consistent mucin secretion and stable expression of selected markers over the whole culture duration. We conclude that POEC are suitable for experiments from 3 weeks up to at least 6 weeks of culture. Therefore, this culture system could be used for in vitro estrous cycle simulation and long-term investigation of toxic effects on oviduct epithelium

Paying the Price: How Health Insurance Premiums Are Eating Up Middle-Class Incomes

Analyzes state-by-state trends in insurance premium costs and as a share of household income. Compares projected cost increases by 2015 and 2020 under three scenarios for growth depending on the effects of healthcare reform. Discusses policy implications

Rite of Passage? Why Young Adults Become Uninsured and How New Policies Can Help, 2008 Update

Assesses the increase in young adults without health insurance -- their demographics and income levels, causes and implications, and federal and state actions taken -- and suggests targeted policy options to cover students and recent graduates

Rite of Passage? Why Young Adults Become Uninsured and How New Policies Can Help

Assesses the scope of the health insurance problem facing young adults, its causes and implications, and offers policy changes that could help them stay insured as they make the transition to independent living

Health Coverage for Aging Baby Boomers: Findings From The Commonwealth Fund Survey of Older Adults

Examines healthcare quality and access by baby boomers in working families. Offers recommendations for expanding coverage, including options for savings accounts and early participation in Medicare

Establishment and characterization of a differentiated epithelial cell culture model derived from the porcine cervix uteri

<p>Abstract</p> <p>Background</p> <p>Cervical uterine epithelial cells maintain a physiological and pathogen-free milieu in the female mammalian reproductive tract and are involved in sperm-epithelium interaction. Easily accessible, differentiated model systems of the cervical epithelium are not yet available to elucidate the underlying molecular mechanisms within these highly specialized cells. Therefore, the aim of the study was to establish a cell culture of the porcine cervical epithelium representing <it>in vivo</it>-like properties of the tissue.</p> <p>Results</p> <p>We tested different isolation methods and culture conditions and validated purity of the cultured cells by immunohistochemistry against keratins. We could reproducibly culture pure epithelial cells from cervical tissue explants. Based on a morphology score and the WST-1 Proliferation Assay, we optimized the growth medium composition. Primary porcine cervical cells performed best in conditioned Ham's F-12, containing 10% FCS, EGF and insulin. After cultivation in an air-liquid interface for three weeks, the cells showed a discontinuously multilayered phenotype. Finally, differentiation was validated via immunohistochemistry against beta catenin. Mucopolysaccharide production could be shown via alcian blue staining.</p> <p>Conclusions</p> <p>We provide the first suitable protocol to establish a differentiated porcine epithelial model of the cervix uteri, based on easily accessible cells using slaughterhouse material.</p

Bending the Curve: Options for Achieving Savings and Improving Value in Health Spending

Analyzes the potential of fifteen federal health policy options to lower spending over the next ten years and yield higher value on investments in health care

Rite of Passage? Why Young Adults Become Uninsured and How New Policies Can Help, 2009 Update

Provides an annual assessment of the uninsurance of 19- to 29-year-olds and their demographics, incomes, and health status. Outlines federal and state actions to expand access to coverage and suggests policy options to address the impact of the recession