The objective of this paper was to fabricate a biodegradable tubular scaffold for small diameter (d<6 mm) blood vessel tissue engineering. The tube scaffold needed a porous wall for cell attachment, proliferation and tissue regeneration with its degradation. A novel method given in this paper was to coat a porous layer of poly (epsilon-caprolactone) (PCL) on the outside of a poly (glycolic-co-lactic acid) (PGLA with GA:LA=90:10) fiber braided tube to give a PCL-PGLA composite. The PGLA tube was fabricated using a braiding machine by inserting a Teflon tube with the desired diameter in center of the 20 spindles, which are the carriers of PGLA fibers. Changing the diameter of the Teflon tube can vary the inner diameter of a braided PGLA tube. Thermally induced phase separation method was used for PCL solution coating on the surface of the PGLA braided tube. Controlling the polymer concentration, non-solvent addition and quenching temperature generated the pore structures, with pore sizes ranging from 10-30 microm. The fibroblast cells were seeded on the tubular scaffold and cultured in vitro for the biocompatibility investigation. Histology results showed that the fibroblast cells proliferated on the interconnected pore of the PCL porous layer in 1 week.
Biocompatible Materials/chemistry , Lactic Acid/chemistry , Polyesters/chemistry , Polyglycolic Acid/chemistry , Polymers/chemistry , Tissue Engineering , 3T3 Cells , Absorbable Implants , Animals , Bioprosthesis , Blood Vessel Prosthesis , Cell Proliferation , Coated Materials, Biocompatible/chemistry , Fibroblasts/cytology , Materials Testing , Mice , Polylactic Acid-Polyglycolic Acid Copolymer , Polytetrafluoroethylene/chemistry , Porosity , Prosthesis Design , Temperature , Time Factors
The goal is to describe the structure of administration for the control of infectious diseases in the German states. Internationally there is an increasing risk of potentially global transmission of infectious diseases and therefore increasing need for improved control mechanisms which are viable locally, regionally and internationally. The international public health community must ensure that responses to infectious disease with a potential impact on more than one county entail concerted action, clear communication and decision making by diverse administration agencies. Given Germany's federal structure, the 16 states have differing protocols delineating responsibilities for infection control systems. This paper provides an overview, going into detail only with regard to the administration structure in Hesse. In 2001, the German law governing infectious disease control was amended and significantly expanded. With regard to protection of humans from infectious disease, each state must define its schedule of responsibilities on the resulting scope of duties. Each state in Germany has entrusted the local public health service at the county level with the responsibility for infection prevention and control. As a rule, at the state level both an expert agency and one or more district administration agencies have been installed; these work directly with the Ministry of Health at the state level. In addition to this, Hesse has established a "centre of competence for highly contagious diseases." In the event of an infectious emergency, this network provides special treatment of highly infectious patients and expertise for public health services and the Ministry of Health on a 24-h shift basis. In times of ongoing structural transformation, it is important to emphasize that expertise at the state level is not an alternative to maintaining enough specialised personnel in the public health services themselves. Specialized practitioners are needed to ensure professional and fast-acting responses, both for the prevention and control of infectious diseases.
Communicable Disease Control/methods , Communicable Disease Control/organization & administration , Communicable Diseases/diagnosis , Federal Government , Government Agencies/organization & administration , Health Promotion/organization & administration , National Health Programs/organization & administration , Germany , Health Policy , Health Promotion/methods , Humans , Public Health/methods , Public Health Administration/methods , Public Policy
A general principle for biohydroxylation, in which time-consuming screening and enrichment techniques are avoided, is demonstrated by the introduction of a docking/protecting group into the substrate. This facilitates acceptance by the microorganism and allows the use of a narrow range of microorganisms, for example Beauveria bassiana ATTC 7159 (B. b.), for the hydroxylation of compounds with diverse structures. After the biohydroxylation, the docking/protecting group is removed (see scheme).
