ABSTRACT
Nanocomposites were prepared with segmented polyurethanes and Cloisite 30B by either solution mixing or in situ polymerization and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. Cytotoxicity and genotoxicity were assessed with lymphocytes while cell viability was measured by the methyl tetrazolium assay using fibroblasts. It was found that in situ polymerization rendered exfoliated nanocomposites with higher glass transition temperature, tensile modulus and thermal stability compared to nanocomposites obtained by solution mixing. The mitotic index of lymphocytes was significantly reduced at high clay concentrations (6 wt% and 10 wt%), while fibroblast viability improved in the presence of extract obtained after days 2 and 7.
Subject(s)
Bentonite/chemistry , Biocompatible Materials/chemistry , Nanocomposites/chemistry , Polyurethanes/chemistry , Bentonite/toxicity , Biocompatible Materials/toxicity , Cell Survival/drug effects , Cells, Cultured , Fibroblasts/cytology , Fibroblasts/drug effects , Humans , Lymphocytes/cytology , Lymphocytes/drug effects , Materials Testing , Microscopy, Electron, Scanning , Mitosis/drug effects , Nanocomposites/toxicity , Nanocomposites/ultrastructure , Nanotechnology , Polyurethanes/toxicity , Spectroscopy, Fourier Transform Infrared , Tensile Strength , Thermodynamics , X-Ray DiffractionABSTRACT
OBJECTIVE: To describe the main economic-healthcare indicators of Aragon Areas 2 and 5 in 1992. To quantify in economic terms the value of the medical and nursing consultations carried out by Primary Care teams. DESIGN: Cost-analysis type study (total costs). The criteria for attributing indirect costs were established by consensus. The data correspond to 1992 (real spending by each centre). The cost of the consultations was calculated in function of the overall activity undertaken and in line with the type of consultation. SETTING: Areas 2 and 5, Aragon. Calculation of the cost per consultation only for Primary Care teams (PCT). RESULTS: Spending per inhabitant and per year, both overall and broken down into care and pharmacy costs was 20,140 for PCT's (8,805 pesetas + 11,355 pes) and 23,153 pes for the traditional model (7,677 + 15,476 pes). Costs per consultation were: 1,031 pes for General Medicine plus 2,537 on Pharmacy; 1,765 pes for Paediatrics plus 716 on Pharmacy; 972 on nursing. Costs per consultation were also offered in function of the duration of each type of consultation and the health-care delivered. CONCLUSIONS: Overall, PCT's generated less expense per each insured person than the traditionally-based Consulting rooms. This situation is mainly due to Pharmacy costs, where the difference is over 4,000 pesetas. The evaluation of service costs in function of attendance supposes that, between two teams of equal composition and the same volume of spending, the more efficient will be that which produces the greater amount of services.
Subject(s)
Patient Care Team/economics , Primary Health Care/economics , Costs and Cost Analysis , Drug Therapy/economics , Humans , SpainABSTRACT
Von Willebrand factor (vWF) availability was assessed in platelet concentrates (PCs). After 5 days of storage, 82 +/- 9% of basal levels of ristocetin cofactor activity (vWF:RCo) remained in PCs. vWF antigen (vWF:Ag) increased up to 166 +/- 38% (P < 0.05) in the same period. Autoradiograph pattern of vW:Ag showed an increase in low molecular weight multimers, and fast migrating multimeric forms were visualized by crossed immunoelectrophoresis on day 5. Studies carried out in platelet free plasma stored as PCs showed similar changes in vWF:RCo but increments in vWF:Ag were not detected. These data indicate that PCs maintain vWF:RCo levels of clinical value even after 5 days of storage and suggest that vWF comes out from platelets to plasma during storage.
Subject(s)
Blood Platelets , Blood Preservation , von Willebrand Factor/analysis , Blood Platelets/chemistry , Humans , Time FactorsABSTRACT
Aggregation was studied with synergistic agents on platelets stored for 5 days. Fixed concentrations of agonist agents, capable of inducing maximum response upon platelet concentrate (PC) preparations were used, and the results were compared with those achieved from samples previously incubated in fresh autologous plasma. Platelet aggregation on day 0 ranged between 77 +/- 3% with the combination epinephrine/ADP and 72 +/- 7% with collagen/ADP, these figures decreasing by the fifth day to 14 +/- 5% and 10 +/- 4%, respectively. The other paired aggregation agents were epinephrine/collagen and arachidonic acid (AA)/ADP; with these agents, similar values were attained on day 0, along with an analogous derangement of the response by the fifth day. With the last combination, the aggregation value attained on days 3 was 14 +/- 10% in experiments with the PC plasma, as opposed to 49 +/- 15% in assays with fresh plasma (p less than 0.001). Such difference persisted on day 5 and was thought to be due to competence of the high concentration of fatty acids generated in the PC plasma by AA. No differences induced by fresh plasma on the other agonist combinations were detected. These results suggest that some derangement of platelet function, conditioned by nonreversible alterations, and measured by paired agonist aggregation, may derive from storage.
