Fabrication of three-dimensional multi-protein microstructures for cell migration and adhesion enhancement

In this study, three-dimensional (3D) multi-component microstructures were precisely fabricated via multiphoton excited photochemistry using a femtosecond laser direct-writing system with proposed repetition positioning and vector scanning techniques. Extracellular matrix (ECM) proteins, such as fibronectin (FN), are difficult to stack and form 3D structures larger than several-hundred microns in height due to the nature of their protein structure. Herein, to fabricate complex 3D microstructures with FN, a 3D scaffold was designed and formed from bovine serum albumin (BSA), after which human FN was inserted at specific locations on the BSA scaffold; in this manner, the fabricated ECM microstructure can guide cells in a 3D environment. A human breast cancer cell line, MDA-MB-231, was used to investigate the behavior of cell migration and adhesion on the fabricated human FN and BSA protein structures. Experimental results indicate that many cells are not able to attach or climb on a 3D structure’s inclined plane without FN support; hence, the influence of cell growth in a 3D context with FN should being taken into consideration. This 3D multi-protein fabrication technique holds potential for cell studies in designed complex 3D ECM scaffolds.OCIS codes: (160.1435) Biomaterials, (190.4180) Multiphoton processes, (110.3960) Microlithography, (220.4000) Microstructure fabrication     

Demand-oriented and demand-driven health care: the development of a typology

In most European countries, there is an increasing demand for demand-oriented and demand-driven approaches in the development of health care policy and the organization of health care services. Both approaches, in which the main focus is on 'the demand', are seen as counterparts of the supply-oriented approach, that has 'the supply' as point of departure. However, there is much confusion about the definition of the concepts. To identify the different views, and to examine to what extent there is consensus in the Netherlands about the concepts of demand-orientation and demand-driven care, a Delphi study was done among 26 experts; scientists, health care insurance companies, health care suppliers, the government, independent advisory bodies and client interest groups. The study resulted in a typology. The similarities and differences between the two concepts were demonstrated in five dimensions; responsibility, control, need-determination, formal embedment of vision in organization and choice. Furthermore, the typology was used to identify existing types of services as being either demand-oriented or demand-driven services. The typology provides an understanding of the similarities and differences between the two concepts, and appears to be a useful tool in identifying services to the extent that they are demand oriented or demand driven.     

The disappearance of a low molecular weight heparin fraction (CY 216) differs from standard heparin in rabbits

In previous studies, we have reported that standard heparin (SH) was cleared by two mechanisms, a saturable mechanism which predominated at low doses (<100 anti-factor Xa U/kg) and a non-saturable mechanism which predominated at higher doses, when the first mechanism became saturated. In this study, we examined the importance of these two mechanisms in the disappearance of a low molecular weight heparin fraction (LMWH) (CY 216), by comparing the pharmacokinetics and the pharmacodyna-mics of a wide range of doses of SH and CY 216 (1.5 to 500 anti-factor Xa U/kg) Pharmacokinetics was measured as the disappearance of ¹²⁵I-radiolabelled SH or CY 216. Pharmacodynamics was measured as the disappearance of the anti-factor Xa activity of SH and CY 216. We found that the saturable mechanism contributed little to the disappearance of CY 216 and that it was cleared predominantly by the non-saturable mechanism at all doses tested. Thus, at low doses (<100 anti-factor Xa U/kg), SH was cleared more rapidly than CY 216, whereas at higher doses, CY 216 was cleared more rapidly than SH. We conclude that the mechanism of disappearance of LMWH's differ significantly from those of SH, and that this difference may explain the apparent prolonged anticoagulant activity of LMWH's within the therapeutic range doses.     

Predictive value of EEG in neonates with periventricular leukomalacia

The aim of this study was to evaluate whether EEG (i.e. positive Rolandic sharp waves) can be used to predict neurodevelopment in newborn infants with periventricular leukomalacia and compare the predictive value with that of MRI. A sequential cohort of neonates (n=45; 33 males, 12 females; mean gestational age 31.2 weeks, SD 2.7, range 27 to 37.8 weeks; mean birthweight 1592 g, SD 601 g) with periventricular hyperechogenicities on cranial ultrasound was recruited for this study. EEGs were analyzed for positive Rolandic sharp waves. Neurodevelopment was evaluated at the ages of 12 and 18 months. In the whole group the probability of a poor outcome was 24% and the probability of any impairment was 33%. If the number of positive Rolandic sharp waves was no more than 0.1 per minute, the probability of a poor outcome was reduced to 9% (95% confidence interval [95%CI] 2 to 27%) and the probability of any impairment was reduced to 13% (95%CI 4 to 32%). In all infants with more than 0.1 positive Rolandic sharp waves per minute the probability of a poor outcome was 41% (95%CI 23 to 61%) and of any impairment was 55% (95%CI 34 to 73%). In these infants MRI identified infants with a poor outcome with a sensitivity of 1.00 (95%CI 0.70 to 1.00) and a specificity of 0.92 (95%CI 0.67 to 0.99), and infants with any impairment with a sensitivity of 0.83 (95%CI 0.55 to 0.95) and a specificity of 1.00 (95%CI 0.72 to 1.00). Results suggest that if an EEG of an infant with periventricular leukomalacia contains no more than 0.1 positive Rolandic sharp waves per minute the probability of a normal or mildly delayed development is high (0.91, 95%CI 0.73 to 0.98). MRI enhances the accuracy of the outcome prediction slightly; however, owing to a wide confidence interval, this advantage is negligible. However, if the frequency of the positive Rolandic sharp waves exceeds 0.1per minute, MRI can significantly enhance the precision of the prediction of outcome.