-Using-atomic-force-microscopy-the-transparent-membrane-was-determined-to-contain-fibrils-having-an-average-diameter-of-76--14-nm-whereas-the-opaque-membrane-comprised-fibrils-with-an-average-diameter-of-391--99-nm-a

As the acidity of the membranes must be neutralized before they can serve as cell culture substrates, the structure and piezoelectric properties of the membranes were measured under ambient conditions before and after the neutralization process. A crimp structure (19 ± 07 µm in width) perpendicular to the fibril alignment became apparent in the transparent membrane when the pH was adjusted from acidic (pH = 2) to neutral (pH = 7) conditions. In addition, a 15-fold increase was observed in the amplitude of the shear piezoelectricity of the transparent membrane. The structure and piezoelectric properties of the opaque membrane were not significantly affected by the neutralization process. The results highlight the presence of an additional translational order in the transparent membrane in the direction perpendicular to the fibril alignment. The piezoelectric response of both membrane types was found to be an order of magnitude lower than that of collagen fibrils in rat tail tendon.

This reduced response is attributed to less-ordered molecular assembly than is present in D-periodic collagen fibrils, as evidenced by the absence of D-periodicity in the membranes.Osteogenesis imperfecta (lethal) bones contain types III and V collagens.Pope FM, Nicholls AC, Eggleton C, Narcissi P, Hey EN, Parkin JM.Lethal osteogenesis imperfecta (OI-L) and normal fetal bones contain types I and V collagen with relatively more type V in OI-L bones. The latter, unlike normal fetal bone, also contain some type III collagen. Such altered collagen ratios could directly produce the bony fragility and radiotranslucency of OI-L bones. Since this is an inherited osteoporosis similar alterations in acquired Qualitative and quantitative evaluation of total and types I and III collagens AIM: The purpose of this study was to evaluate the amount of total and types I and III collagens of samples from the linea alba in patients with hernias (epigastric, umbilical, and incisional) on the anterior wall of the abdomen, comparing them to findings obtained from a cadaver control group without MATERIALS AND METHODS: Samples of the linea alba aponeurosis from 26 patients with hernias on the anterior abdominal wall and from 32 cadavers without hernias were analyzed and compared for qualitative and quantitative evaluation of the total and the types I and III collagens.

Sirius-red staining was used to evaluate the total collagen, and for types I and III collagens, immunohistochemistry was used with monoclonal antibody anticollagen types I and RESULTS: The amount of total collagen was 185% smaller in patients with hernias than in cadavers (p<05). Type I collagen was 200% smaller in patients than in cadavers (p<05). There was no significant difference in the amount of type III collagen between cases and controls (p=083).CONCLUSION: The results of this study indicate a relationship between hernias of the anterior abdominal wall and smaller amounts of total and type I collagens.Collagen XII mediated cellular and extracellular mechanisms regulate establishment of tendon structure and function.States; Okayama University of Science, Ehime, Japan. Electronic address: Department of Dermatology, Center for Molecular Medicine Cologne, University of Tendons have a uniaxially aligned structure with a hierarchical organization of collagen fibrils crucial for tendon function.

Collagen XII is expressed in tendons and has been implicated in the regulation of fibrillogenesis. It is a non-fibrillar collagen belonging to the Fibril-Associated Collagens with Interrupted Triple Helices (FACIT) family. Mutations in COL12A1 cause myopathic Ehlers Danlos Syndrome with a clinical phenotype involving both joints and tendons supporting critical role(s) for collagen XII in tendon development and function. Here we demonstrate the molecular function of collagen XII during tendon development using a Col12a1 null mouse model. Col12a1 deficiency altered tenocyte shape, formation of interacting cell processes, and organization resulting in impaired cell-cell communication and disruption of hierarchal structure as well as decreased tissue stiffness. Immuno-localization revealed that collagen XII accumulated on the tenocyte surface and connected adjacent tenocytes by building matrix bridges between the cells, suggesting that collagen XII regulates intercellular communication. In addition, there was a decrease in fibrillar collagen I in collagen XII deficient tenocyte cultures compared with controls suggesting collagen XII signaling specifically alters tenocyte biosynthesis.

This suggests that collagen XII provides feedback to tenocytes regulating extracellular collagen I. Together, the data indicate dual roles for collagen XII in determination of tendon structure and function. Through association with fibrils it functions in fibril packing, fiber assembly and stability. In Snag it now , collagen XII influences tenocyte organization required for assembly of higher order structure; intercellular communication necessary to coordinate long range order and feedback on tenocytes influencing collagen synthesis.