Color evaluation of a dielectric mirror coating using porcine tissue and prosthetic gingival material: a comparison of two models

SummaryIn the fibrin plate assay different types of relationships between the dose of applied proteolytic enzyme and the response have been previously reported. This study was undertaken to determine whether a generally valid relationship might exist.Trypsin, chymotrypsin, papain, the plasminogen activator urokinase and all of the microbial proteases investigated, including brinase gave a linear relationship between the logarithm of the enzyme concentration and the diameter of the circular lysed zone. A similar linearity of dose-response curves has frequently been found by investigators who used enzyme plate assays with substrates different from fibrin incorporated in an agar gel. Consequently, it seems that this linearity of dose-response curves is generally valid for the fibrin plate assay as well as for other enzyme plate bioassays.Both human plasmin and porcine tissue activator of plasminogen showed deviations from linearity of semi-logarithmic dose-response curves in the fibrin plate assay.

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Separation of Plasminogen Activators from Human Uterine Tissue and a Comparison with Activators from Human Urine and Porcine Tissue

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646832 ◽

1979 ◽

Vol 41 (04) ◽

pp. 718-733 ◽

Cited By ~ 24

Author(s):

Preben Kok

Keyword(s):

Plasminogen Activator ◽

Human Urine ◽

Gel Filtration ◽

Ammonium Thiocyanate ◽

Plasminogen Activators ◽

Particle Sizes ◽

Uterine Tissue ◽

Porcine Tissue ◽

Major Activity ◽

Proliferative Phase

SummaryThree types of plasminogen activator could be distinguished in extracts from human uterine tissue. The activators differed in thermostability or in mode of inhibition by EACA.All the extracts contained stable as well as labile activators. The saline extracts were uniformly inhibited by increasing concentrations of EACA. Extracts made with 2 M ammonium thiocyanate were either uniformly inhibited by EACA or showed deflections indicating contamination with an activator, which was inhibited in a biphasic manner. It was possible to distinguish between: (1) An activator, abundantly present in the tissue, which was uniformly inhibited and stable. (2) Another uniformly inhibited activator, which was labile. (3) An activator, inhibited in a biphasic manner, similar to urokinase, which was present in varying amounts in uteri with the endometrium in the proliferative phase.Gel filtration of the uterine extracts showed two major activity peaks corresponding to particle sizes of 60,000 dalton and about 10,000 dalton.Antiserum to purified plasminogen activator, prepared from porcine ovaries, inhibited the activity of the human uterine extracts, but not the activities of human urokinase or urine. Urokinase antiserum in a concentration completely inhibiting human urine or urokinase, inhibited only 10% or less of the activities of human uterine extracts.

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Observing and controlling a Tamm plasmon at the interface with a metasurface

Nanophotonics ◽

10.1515/nanoph-2019-0514 ◽

2020 ◽

Vol 9 (4) ◽

pp. 897-903 ◽

Cited By ~ 4

Author(s):

Oleksandr Buchnev ◽

Alexandr Belosludtsev ◽

Victor Reshetnyak ◽

Dean R. Evans ◽

Vassili A. Fedotov

Keyword(s):

Liquid Crystal ◽

Metal Film ◽

Near Infrared ◽

Thin Metal Film ◽

Outer Side ◽

Spectral Position ◽

External Perturbations ◽

Dielectric Mirror ◽

Wavelength Scale ◽

Sub Wavelength

AbstractWe demonstrate experimentally that Tamm plasmons in the near infrared can be supported by a dielectric mirror interfaced with a metasurface, a discontinuous thin metal film periodically patterned on the sub-wavelength scale. More crucially, not only do Tamm plasmons survive the nanopatterning of the metal film but they also become sensitive to external perturbations as a result. In particular, by depositing a nematic liquid crystal on the outer side of the metasurface, we were able to red shift the spectral position of Tamm plasmon by 35 nm, while electrical switching of the liquid crystal enabled us to tune the wavelength of this notoriously inert excitation within a 10-nm range.

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In Situ “Humanization” of Porcine Bioprostheses: Demonstration of Tendon Bioprostheses Conversion into Human ACL and Possible Implications for Heart Valve Bioprostheses

Bioengineering ◽

10.3390/bioengineering8010010 ◽

2021 ◽

Vol 8 (1) ◽

pp. 10

Author(s):

Uri Galili ◽

Kevin R. Stone

Keyword(s):

Extracellular Matrix ◽

Heart Valves ◽

Cruciate Ligament ◽

Anticoagulation Therapy ◽

Young Patients ◽

Collagen Fibers ◽

Reconstruction Process ◽

Bioprosthetic Heart Valves ◽

Porcine Tissue ◽

Anterior Cruciate

This review describes the first studies on successful conversion of porcine soft-tissue bioprostheses into viable permanently functional tissue in humans. This process includes gradual degradation of the porcine tissue, with concomitant neo-vascularization and reconstruction of the implanted bioprosthesis with human cells and extracellular matrix. Such a reconstruction process is referred to in this review as “humanization”. Humanization was achieved with porcine bone-patellar-tendon-bone (BTB), replacing torn anterior-cruciate-ligament (ACL) in patients. In addition to its possible use in orthopedic surgery, it is suggested that this humanization method should be studied as a possible mechanism for converting implanted porcine bioprosthetic heart-valves (BHV) into viable tissue valves in young patients. Presently, these patients are only implanted with mechanical heart-valves, which require constant anticoagulation therapy. The processing of porcine bioprostheses, which enables humanization, includes elimination of α-gal epitopes and partial (incomplete) crosslinking with glutaraldehyde. Studies on implantation of porcine BTB bioprostheses indicated that enzymatic elimination of α-gal epitopes prevents subsequent accelerated destruction of implanted tissues by the natural anti-Gal antibody, whereas the partial crosslinking by glutaraldehyde molecules results in their function as “speed bumps” that slow the infiltration of macrophages. Anti-non gal antibodies produced against porcine antigens in implanted bioprostheses recruit macrophages, which infiltrate at a pace that enables slow degradation of the porcine tissue, neo-vascularization, and infiltration of fibroblasts. These fibroblasts align with the porcine collagen-fibers scaffold, secrete their collagen-fibers and other extracellular-matrix (ECM) components, and gradually replace porcine tissues degraded by macrophages with autologous functional viable tissue. Porcine BTB implanted in patients completes humanization into autologous ACL within ~2 years. The similarities in cells and ECM comprising heart-valves and tendons, raises the possibility that porcine BHV undergoing a similar processing, may also undergo humanization, resulting in formation of an autologous, viable, permanently functional, non-calcifying heart-valves.

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