Background: Immortalized human endothelial cells are widely used as in vitro models for debilitating conditions such as cancer, cardiovascular and ocular diseases. Human microvascular endothelial cell (HMEC-1) is immortalized via stable transfection with a gene encoding SV40 large antigen whilst telomerase-immortalized human microvascular endothelial (TIME) cells is immortalized by engineering the human telomerase catalytic protein (hTERT) into primary microvascular endothelial cells. Here, we established a three-dimensional (3D) spheroid invasion assay with HMEC-1 and TIME and compared the difference in their ability to invade through the collagen matrix in response to exogenous growth factors, namely vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Methods: TIME and HMEC-1 spheroids were embedded in a collagen matrix. The spheroids were stimulated with exogenous growth factors, namely VEGF (50ng/mL) and bFGF (200ng/mL). Twelve points of invasion length from a spheroid was measured using image analysis software, Image J. Three independent experiments were conducted and data was analysis by GraphPad Instat software, version 3.05. Results: TIME spheroid invasion was 16.5 fold higher with exogenous VEGF (50ng/mL) and bFGF (200ng/mL) treatment as compared to those cultured in complete growth medium only. In contrast, no significant difference was observed between HMEC-1 spheroids stimulated with and without exogenous growth factors, VEGF and bFGF. Conclusions: This is the first report on the establishment of a 3D-spheroid invasion assay with TIME cells. The requirement of VEGF and bFGF for TIME spheroids invasion is a novel finding. In addition, this assay offers an advantage over HMEC-1 for testing novel angiogenic agents since it is not affected by endogenously secreted growth factors.

INTRODUCTIONIntertrochanteric (IT) fractures are associated with significant morbidity and mortality in the elderly population. We aim to compare the clinical outcome of unstable with stable IT fractures after treatment with dynamic hip screw (DHS).

MATERIALS AND METHODSPatients with IT fractures treated with DHS at National University Hospital between 2003 and 2005 were included in the study. Patients were divided into 2 groups: stable and unstable IT fractures. Clinical outcome parameters include perioperative complications, functional outcomes, and incidence of morbidity and mortality.

RESULTSOne hundred and thirty-six patients were analysed. Mean age was 77 years. There were 61 stable and 78 unstable fractures. Average length of follow-up was 30 months. The rates of local complications were not significantly different between the 2 groups. The incidence of malunion and excessive impaction were significantly higher in the unstable group. The ambulatory status at one year post-surgery was not significantly different between the 2 groups. In terms of general postoperative complications and one year mortality rate, there was no significant difference between the 2 groups. The need for blood transfusion was significantly higher in the unstable group.

CONCLUSIONIn summary, DHS fixation provides comparable postoperative outcomes in unstable IT fractures with relatively low rates of complications. Although it was associated with a higher incidence of malunion and excessive impaction in the unstable fracture group, there was no difference in functional status at one-year compared to the stable group.

Aged ; Aged, 80 and over ; Bone Screws ; Female ; Fracture Fixation, Internal ; Hip Fractures ; surgery ; Humans ; Male ; Postoperative Complications ; epidemiology ; Retrospective Studies ; Singapore ; epidemiology ; Treatment Outcome