The Struggle of Islam in Modern Indonesia

Regional and national histor

The Struggle of Islam in Modern Indonesia

Regional and national histor

Portion Size: What We Know and What We Need to Know

There is increasing evidence that the portion sizes of many foods have increased and in a laboratory at least this increases the amount eaten. The conclusions are, however, limited by the complexity of the phenomenon. There is a need to consider meals freely chosen over a prolonged period when a range of foods of different energy densities are available. A range of factors will influence the size of the portion size chosen: amongst others packaging, labeling, advertising, and the unit size rather than portion size of the food item. The way portion size interacts with the multitude of factors that determine food intake needs to be established. In particular, the role of portion size on energy intake should be examined as many confounding variables exist and we must be clear that it is portion size that is the major problem. If the approach is to make a practical contribution, then methods of changing portion sizes will need to be developed. This may prove to be a problem in a free market, as it is to be expected that customers will resist the introduction of smaller portion sizes, given that value for money is an important motivator

Development of in vivo muCT evaluation of neovascularisation in tissue engineered bone constructs

Due to an increasing aging population the need for innovative approaches to aid skeletal repair and reconstruction is a significant socio-economic increasing problem. The emerging discipline of tissue engineering has sort to augment the growth and repair of bone loss particularly in areas of trauma, degeneration and revision surgery. However, the initiation and development of a fully functional vascular network are critical for bioengineered bone to repair large osseous defects, whether the material is osteosynthetic (poly (d,l)-lactic acid, PLA) or natural bone allograft. Quantification and three-dimensional visualization of new vessel networks remain a problem in bone tissue engineering constructs. A novel technique utilising a radio-opaque dye and micro-computed tomography (muCT) has been developed and applied to study angiogenesis in an impaction bone graft model. Tissue-engineered constructs combining human bone marrow stromal cells (HBMSC) with natural allograft and synthetic grafts (PLA) were impacted and implanted into the subcutis of MF-1 nu/nu mice for a period of 28 days. Microfil consisting of radio-opaque polymer was perfused through the mice and scanned using a Bench Top CT system for micro-computed tomography. Analysis of three-dimensional muCT reconstructions demonstrated an increase in vessel volume and vessel number in the impacted scaffolds/HBMC compared to scaffolds alone. Vessel volume: allograft/HBMSC=0.57 mm(3)+/-0.19; allograft=0.04 mm(3)+/-0.04; PLA/HBMSC=1.19 mm(3)+/-0.31; and PLA=0.12 mm(3)+/-0.01. Penetrating vessel number: allograft/HBMSC=22.33+/-3.21; allograft=3.67+/-1.153; PLA/HBMSC=32.67+/-8.33; and PLA=7.67+/-3.06. Type 1 collagen and von Willebrand factor immunohistochemistry in scaffold/HBMSC constructs indicated the osteogenic cell phenotype, and new blood vessel formation respectively. Contrast-enhanced 3D reconstructions facilitated the visualization and quantification of neovascularisation. This novel technique has been used to demonstrate neovascularisation in impacted tissue engineered constructs providing a facile approach with wide experimental application

The application of human bone marrow stromal cells and poly(dl-lactic acid) as a biological bone graft extender in impaction bone grafting

Concerns over disease transmission, high costs and limited supply have led to interest in synthetic grafts in the field of impaction bone grafting (IBG). Poly(DL-lactic acid) (PLA) grafts are attractive alternatives due to their biocompatibility, established safety and versatile manufacturing process. This study examined the potential of PLA scaffolds augmented with human bone marrow stromal cells (HBMSCs) in IBG. In vitro and in vivo studies were performed on impacted morsellised PLA seeded with HBMSC and compared to PLA alone. In vitro samples were incubated under osteogenic conditions and in vivo samples were implanted subcutaneously into severely compromised immunodeficient mice, for 4 weeks. Biochemical, histological, mechanical and 3D micro-computed tomography analyses were performed. HBMSC viability, biochemical activity and histological evidence of osteogenic cellular differentiation, post-impaction were observed in vitro and in vivo in PLA/HBMSC samples compared to impacted PLA alone. In vitro PLA/HBMSC samples demonstrated evidence of mechanical enhancement over PLA alone. In vivo studies showed a significant increase in new bone and blood vessel formation in the PLA/HBMSC constructs compared to PLA alone. With alternatives to allograft being sought, these studies have demonstrated PLA/HBMSC living composites, to be a potential prospect as a biological bone graft extender for future use in the field of IBG