Living tissues, heterogeneous at the microscale, usually scatter light

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Living tissues, heterogeneous at the microscale, usually scatter light

Strong scattering is responsible for the whiteness of bones, teeth, and brain and is known to limit severely the performances of biomedical optical imaging. Transparency is also found within collagen-based extracellular tissues such as decalcified ivory, fish scales, or cornea. However, its physical origin is still poorly understood. Here, we unveil the presence of a gap of transparency in scattering fibrillar collagen matrices within a narrow range of concentration in the phase diagram. This precholesteric phase presents a three-dimensional (3D) orientational order biomimetic of that in natural tissues. By quantitatively studying the relation between the 3D fibrillar network and the optical and mechanical properties of the macroscopic matrices, we show that transparency results from structural partial order inhibiting light scattering, while preserving mechanical stability, stiffness, and nonlinearity.

The striking similarities between synthetic and natural materials provide insights for better understanding the occurring transparency.Conflict of interest statement: The authors declare no competing interest.6575. J Biol Chem. 1975 Dec 25;250(24):9304-12.Isolation and characterization of CNBr peptides of human (alpha 1 (III) )3 collagen and tissue distribution of (alpha 1 (I) )2 alpha 2 and (alpha 1 (III) [Alpha 1(III)]3 collagen was solubilized by pepsin digestion of normal human placental membranes and was purified by differential salt precipitation and carboxymethylcellulose chromatography. This collagen was digested with CNBr, and the resultant nine peptides were isolated and characterized.

The chains are cross-linked by cysteinyl residues in the COOH-terminal peptide. Isolation of peptides derived from CNBr digestion of insoluble tissues was used as an assay for the presence of [alpha 1(I)]2alpha 2 and [alpha 1(III)]3 collagens. Both types are present in human skin, intestine, liver, spleen, kidney, lung, aorta, umbilical cord, placental membranes, and myocardium. Bone and tendon contain [alpha 1(I)]2alpha 2 collagen but, unlike the other tissues, lack [alpha 1(III)]3 collagen. Both [alpha 1(I)]2alpha 2 and[alpha 1(III)]3 collagens are present in scars of human skin, myocardium, tendon, and liver and of rabbit skin. The degree of hydroxylation of proline was 4 to 5% lower in the same peptides in skin, bone, and tendon than in the other tissues. The degree of hydroxylation of lysine in the same peptides derived from different tissues Enhanced and persistent antibody response against homologous and heterologous strains elicited by a MF59-adjuvanted influenza vaccine in infants and young Research Institute, University of Melbourne, Melbourne, Australia.

Electronic BACKGROUND: Non-adjuvanted seasonal influenza vaccines show only modest efficacy in young children. This study compared the immunogenicity, reactogenicity and safety of the MF59-adjuvanted trivalent subunit vaccine (aTIV) with two non-adjuvanted trivalent vaccines, TIV-1, the non-adjuvanted version of aTIV, METHODS: 6078 children received two doses of aTIV (n=3125), TIV-1 (n=1479), or TIV-2 (n=1474) four weeks apart (Days 1 and 29). Children aged 6 to <36 months and 36 to <72 months received 05 mL and 00 mL doses, respectively.  what is squalane  was assessed by hemagglutination inhibition (HI) assay (n=2435) on Days 1, 29, 50 and 209. Safety was assessed up to Day 394.RESULTS: After the second vaccination (Day 50), the aTIV group showed significantly higher geometric mean HI titers and seroconversion rates than the TIV-1 or TIV-2 groups against all homologous and heterologous strains. The difference was enhanced at HI titers ≥110.

aTIV elicited a faster, more persistent antibody response, with significantly higher titers in the aTIV group after one vaccination (Day 29) and after six months (Day 209) than in either TIV group. aTIV was more reactogenic than were TIV-1 and TIV-2 but rates of severe adverse events were very low for all three vaccines.CONCLUSION: In infants and young children, the MF59-adjuvanted vaccine induced substantially faster (after one dose), higher, persistent HI titers than the non-adjuvanted vaccines, with consistently higher seroprotection rates at increased threshold HI titers. This trial is registered at clinicaltrials.gov: 10152/japplphysiol0944009. Epub 2009 Nov 5.Lower strength of the human posterior patellar tendon seems unrelated to mature collagen cross-linking and fibril morphology.

JO, Krogsgaard M, Kjaer M, Peter Magnusson S.Healthy Aging, University of Copenhagen, DK-2400 Copenhagen NV, Denmark.The human patellar tendon is frequently affected by tendinopathy, but the etiology of the condition is not established, although differential loading of the anterior and posterior tendon may be associated with the condition. We hypothesized that changes in fibril morphology and collagen cross-linking would parallel differences in material strength between the anterior and posterior tendon. Tendon fascicles were obtained from elective ACL surgery patients and tested micromechanically.  squalane  was used to assess fibril morphology, and collagen cross-linking was determined by HPLC and calorimetry. Anterior fascicles were markedly stronger (peak stress: 54 +/- 21 vs.