Several major lung pathologies are characterized by early modifications of the extracellular matrix (ECM) fibrillar collagen and elastin network. We report here the development of a nonlinear fiber-optic spectrometer, compatible with an endoscopic use, primarily intended for the recording of second-harmonic generation (SHG) signal of collagen and two-photon excited fluorescence (2PEF) of both c...

Fibroblasts invade the primary corneal stroma of the 6-day-old chick embryo eye. The way in which these cells build the secondary stroma has been studied by microscope examination of the stroma during the subsequent 8 Days. Eyes were embedded in low viscosity nitrocellulose, and 30-micrometer tangential sections of cornea were cut and stained with azan (giving blue collagen and red cells). Thes...

Fiber bundles are present in many tissues throughout the body. In most cases, collagen subunits spontaneously self-assemble into a fibrilar structure that provides ductility to bone and constitutes the basis of muscle contraction. Translating these natural architectural features into a biomimetic scaffold still remains a great challenge. Here, a simple strategy is proposed to engineer biomimeti...

Lymphatic invasion and accumulation of continuous collagen bundles around tumor cells are associated with poor melanoma prognosis, but the underlying mechanisms and molecular determinants have remained unclear. We show here that a copy-number gain or overexpression of the membrane-type matrix metalloproteinase MMP16 (MT3-MMP) is associated with poor clinical outcome, collagen bundle assembly ar...

Understanding the failure and damage mechanisms of soft biological tissue is critical to a sensitive and specific characterization of tissue injury tolerance and its relation to biological responses. Despite increasing experimental and analytical efforts, failure-related irreversible effects of soft biological tissue are still poorly understood. There is still no clear definition of what "damag...

The regulation of collagen fibril, bundle, and lamella formation by the corneal fibroblasts, as well as the organization of these elements into an orthogonal stroma, was studied by transmission electron microscopy and high voltage electron microscopy. Transmission and high voltage electron microscopy of chick embryo corneas each demonstrated a series of unique extracellular compartments. Collag...

Collagen is the most abundant protein in animals and is a major component of the extracellular matrix in tissues such as skin and bone. A distinctive structural feature of all collagen types is a unique triple-helical structure formed by tandem repeats of the consensus sequence Xaa-Yaa-Gly, in which Xaa and Yaa frequently are proline and hydroxyproline, respectively. Hsp47/SERPINH1 is a procoll...

A continuum hypothesis-based, biomechanical model is presented for the simulation of the collagen bundle distribution-dependent contraction and subsequent retraction of healing dermal wounds that cover a large surface area. Since wound contraction mainly takes place in the dermal layer of the skin, solely a portion of this layer is included explicitly into the model. This portion of dermal laye...

Let $p:Xlo B$ be a locally trivial principal G-bundle and $wt{p}:wt{X}lo B$ be a locally trivial principal $wt{G}$-bundle. In this paper, by using the structure of principal bundles according to transition functions, we show that $wt{G}$ is a covering group of $G$ if and only if $wt{X}$ is a covering space of $X$. Then we conclude that a topological space $X$ with non-simply connected universal...

There is controversy in the literature regarding a number of topics related to anterior cruciate ligament (ACL)reconstruction. The purpose of this article is to answer the following questions: 1) Bone patellar tendon bone (BPTB) reconstruction or hamstring reconstruction (HR); 2) Double bundle or single bundle; 3) Allograft or authograft; 4) Early or late reconstruction; 5) Rate of return to sp...