Silicone tissue expanders were inserted subcutaneously in the buttocks of nine young pigs and gradually inflated to maximum capacity over 5 weeks. On the control side the expanders were left uninflated. Island buttock flaps were then raised, the expanders removed and the flaps spread into the same sites for 10 days. The tissue was harvested. Area measurements and full thickness skin biopsies were taken 10 days after flap inset in order to study the changes in collagen composition and isotypes in the skin layers. Ten days after inset of the flap the expanded skin had a mean 47% increase in surface area, was 9% thinner (from surface to implant), mostly due to thinning of the subcutaneous zone, but was not significantly different in water content, relative to the control skin. The expanded skin had a significant 9.3% increase (p less than 0.01, t test) in collagen content of the dermis. The relative proportions of Types I and III were not significantly changed by skin expansion in either the dermal/epidermal or subcutaneous/capsular zones. It is speculated that tensile factors during expansion stimulate the biosynthetic activity and/or mitotic activity of fibroblasts in the dermis to produce this gain in collagen in the expanded compared with unexpanded tissue.
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http://dx.doi.org/10.1016/0007-1226(90)90121-f | DOI Listing |
Proc Biol Sci
January 2025
Department of Biology and Center for Stable Isotopes, University of New Mexico, Albuquerque, NM, USA.
Retrospective datasets offer essential context for conservation by revealing species' ecological roles before industrial-era human impacts. We analysed isotopic compositions of pre-industrial and modern sea otters () to reconstruct pre-extirpation ecology and offer insights for management. Our study focuses on southeast Alaska (SEAK), where sea otters are recolonizing, and northern Oregon, where translocations are being considered.
View Article and Find Full Text PDFJ Dent Sci
January 2025
School of Dentistry and Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan.
Background/purpose: The efficacy of riboflavin-ultraviolet-A (RF-UVA) treatment in crosslinking collagen and improving dentin bonding has been proven. However, biodegradation of the hybrid layer may compromise the bonding. The purpose of this study was to evaluate different RF-UVA treatments regarding their ability to preserve dentin bonding from enzymatic digestion.
View Article and Find Full Text PDFClin Cosmet Investig Dermatol
January 2025
Department of Dermatology, Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, People's Republic of China.
Dystrophic epidermolysis bullosa (DEB) is a heterogeneous and rare genetic skin disease caused by mutations in the gene, which encodes Type VII collagen. The absence or dysfunction of Type VII collagen can cause the dense lower layer of the basal membrane zone of the skin to separate from the dermis, leading to blister formation and various complications. In different DEB subtypes, the severity of the phenotype is associated, to some extent, with the outcome of Type VII collagen caused by mutations in the gene, which may be reduced in expression, remarkably reduced, or completely absent.
View Article and Find Full Text PDFMol Oral Microbiol
January 2025
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Streptococcus mutans, the principal pathogen associated with dental caries, impacts individuals across all age groups and geographic regions. Beyond its role in compromising oral health, a growing body of research has established a link between S. mutans and various systemic diseases, including immunoglobulin A nephropathy (IgAN), nonalcoholic steatohepatitis (NASH), infective endocarditis (IE), ulcerative colitis (UC), cerebral hemorrhage, and tumors.
View Article and Find Full Text PDFAdv Healthc Mater
January 2025
Nankai University Eye Institute, Nankai University, Tianjin, 300071, China.
Reproducing the microstructure of the natural cornea remains a significant challenge in achieving the mechanical and biological functionality of artificial corneas. Therefore, the development of cascade structures that mimic the natural extracellular matrix (ECM), achieving both macro-stability and micro-structure, is of critical importance. This study proposes a novel, efficient, and general photo-functionalization strategy for modifying natural biomaterials.
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