In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2 × 10(5) cells/cm(2)) by seeding total 9 × 10(5)...

Human endothelial cells (HEC) suspended in a culture medium containing 20% human serum (CMS) adhere and spread on(to) moderately wettable polymers, such as tissue culture polystyrene (TCPS). We have previously shown that serum derived-fibronectin, which is a cell adhesion promoting protein, has a high affinity for TCPS, but that the amount of fibronectin which adsorbed from CMS was relatively s...

The differentiation of proadipocytes in vitro typically required prolonged culture of cells as a high density in high concentrations of serum and added hormones. With such culture conditions it is difficult to design experiments to determine the mechanisms that control the differentiation process. We now describe the rapid and parasynchronous growth arrest and differentiation of low density mur...

human granulocyte-colony stimulating factor (hg-csf) cdna was expressed in the methylotrophic yeast pichia pastoris under the control of the alcohol oxidase (aox1) promoter. an expression vector for hg-csf secretion was constructed using vector ppic9. higher levels of hg-csf was obtained using a p. pastoris mut+ (methanol utilization fast) phenotype. the effects of environmental factors such as...

We have studied the survival requirements of osteoblasts to test the hypothesis that osteoblasts undergo programmed cell death (PCD) or apoptosis unless they are continuously signalled by other cells not to do so. Osteoblasts survived for 6 days in culture at high cell density in the absence of other cell types, serum or exogenous proteins, but they died with the morphological features of apopt...

phytohemagglutinin (pha) is a lectin, obtained from the red kidney bean that binds to the membranes of t-cells and stimulates metabolic activity, cell division, etc. the object of this research was the comparison between self made pha (indigenous) and imported commercial one, following conventional and high resolution cell synchronization technique (hrcs) .from each blood sample of healthy indi...

It is known that cell density influences the maturation process of in vitro neuronal networks. Neuronal cultures plated with different cell densities differ in number of synapses per neuron and thus in single neuron synaptic transmission, which results in a density-dependent neuronal network activity. Although many authors provided detailed information about the effects of cell density on neuro...