Effect of a bovine collagen matrix on tendon adhesions during the repair of rat Achilles tendon.

Adhesion after a tendon injury is one of the major problems following upper extremity surgery. In the present study, we evaluated a new material that is clinically usable as an adhesion barrier. Twenty-four male Wistar albino rats were used in the study. These rats (48 legs) were divided into three groups: sham, control, and experimental. No surgical intervention was performed in the sham group. After making a full-thickness cut through the right Achilles tendon, the tendon was repaired using the modified Kessler technique in the control group, while bovine collagen matrix was wrapped around the surgically repaired tendon using the modified Kessler technique in the experimental group. Two months after surgery, the operated and non-operated tendons were resected and analyzed through biomechanical, macroscopic, and histopathological examinations. The results of the biomechanical testing did not differ significantly between the control and experimental groups. Macroscopic examination of the adhesions revealed less adhesions in the experimental group but this difference was not statistically significant. Moreover, the results of the histopathological examination, which was performed based on five criteria, did not differ significantly between the two groups. Our study's results indicate that a bovine collagen matrix can be used to prevent tendon adhesion; however, larger studies are needed to verify these findings.

Occurrence and Identification of Phytophthora spp. Pathogenic to Pear Fruit in Irrigation Water in the Wenatchee River Valley of Washington State.

ABSTRACT Seven hundred forty-nine isolates of Phytophthora spp. were obtained from irrigation canals in eastern Washington State during the 1992 to 1995 and 1999 growing seasons. Isolates were retrieved using pear baiting techniques. All isolates were pathogenic to pear and were present in irrigation water beginning early in fruit development. Over the course of the 5 year study, 10 and 5% of isolates were identified as P. cactorum and P. citricola, respectively, using morphological criteria. The remaining isolates could not be identified using morphological criteria. Colony morphology of these isolates was characterized during all years of the study. In 1999, more detailed studies utilizing polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis of entire internal transcribed spacer (ITS) regions (ITS1, 5.8S, and ITS2) of ribosomal DNA for 180 isolates, and sequence analysis of ITS2 for 50 isolates, were used to investigate genetic variation and phylogenetic relationships among isolates. Isolates were divided into 12 groups based on their growth type on corn meal agar. Restriction digestion of the entire ITS region with three enzymes revealed 11 restriction digestion patterns among 180 isolates. PCR-RFLP and sequence data were obtained for 12 reference Phytophthora spp. (two species in each of Waterhouse's six morphological groups). Phylogenetic analysis of ITS2 regions revealed nine clades, each with strong bootstrap support. Molecular analyses revealed 23 isolates that were in the P. gonapodyides clade, 9 in the P. parasitica clade, 1 in the P. cactorum clade, 7 in the P. citricola/capsici clade, and 4 in the P. cambivora/pseudotsugae clade. The three isolates comprising clade 5 were significantly distinct from all other Phytophthora spp. in the databases and may represent a new Phytophthora sp. Colony morphology was not consistently correlated to PCR-RFLP pattern or ITS2 phylogeny, suggesting that the former criterion is insufficient for species identification. The results of this study indicate that at least nine phylogenetically distinct taxa of Phytophthora pathogenic to pear are present in irrigation water in North Central Washington.