Tendon and bone responses to a collagen-coated suture material.

Tendon to bone integration after rotator cuff repair is not a reproducible process. During repair, bioabsorbable and nonabsorbable suture material is universally used to facilitate the procedure. Improving the biological architecture of inert suture might aid in overall tendon to bone healing. The objective of our study is to enhance the bone to tendon union by absorbing type I collagen onto high strength nonabsorbable polyester/polyethylene suture commonly used in rotator cuff surgery. Our purpose was to evaluate the tendon and bone cellular response to this novel coated suture compared to uncoated suture. Primary human osteoblasts (HOBs) and tenocytes were plated onto polyester/polyethylene suture that was either uncoated or coated with type I bovine collagen. Cell adhesion to the sutures was assayed at 24 hours. Proliferation was determined at 48 hours by measuring [3H]- Thymidine incorporation in cells attached to the sutures. At 24 and 48 hours, respectively, cells grown on the collagen-coated suture showed a significantly greater response measured by adhesion and proliferation than cells grown on uncoated suture. At five days of culture, alkaline phosphatase activity and protein synthesis was significantly greater on the collagen-coated suture compared to uncoated. Collagen-coated polyester/polyethylene suture appears to stimulate adhesion, proliferation alkaline phosphatase, and protein synthesis more than uncoated sutures, and therefore may aid in the tendon to bone incorporation process critical to rotator cuff repair.

Effect of crop rotation distance on populations of Colorado potato beetle (Coleoptera: Chrysomelidae): development of areawide Colorado potato beetle pest management strategies.

The Colorado potato beetle, Leptinotarsa decemlineata (Say), overwinters adjacent to field edges and infests nearby fields in the spring, primarily by walking. Crop rotation is known to be an effective cultural control against Colorado potato beetle populations limiting spring infestations. Spatial separation is an important consideration in optimizing the rotational effect because long-distance rotations have been shown to reduce Colorado potato beetle infestations. To determine the effect of long-distance rotations on Colorado potato beetle populations in commercial Wisconsin potato production, a geographic area of >18,200 ha (>45,000) acres in southern Portage County, Wisconsin, was selected as an experimental area for areawide pest management of the Colorado potato beetle. From 1997 to 1999, beetle populations at edges within each potato field in this region were determined by spring and fall field sampling. The rotational distance between current and previous potato fields was measured and analysis was run between the distance and Colorado potato beetle populations. Long-distance rotations of >400 m were an effective cultural control management strategy to limit adult beetle infestations in the spring. This strategy can be optimized when collaborating growers are able to maximize their rotational distances by coordinating their rotational schemes within large areawide, geographic locations. Deploying long-distance rotations within a geographic area over many years would limit Colorado potato beetle populations and could result in a significantly reduced Colorado potato beetle populations entering fields in the spring.