Surface Strain on the Equine Hoof Wall In Vivo: Implications for the Material Design and Functional Morphology of the Wall

1992 ◽  
Vol 166 (1) ◽  
pp. 145-168
Author(s):  
J. J. THOMASON ◽  
A. A. BIEWENER ◽  
J. E. BERTRAM
Keyword(s):  
Weight Bearing ◽  
Material Design ◽  
Anterior Wall ◽  
Surface Strain ◽  
Biaxial Compression ◽  
Peak Strain ◽  
The Third ◽  
Principal Strains

Surface strains were recorded from four rosette gauges at different sites on the right forehooves of three ponies running on a treadmill at seven constant speeds and using three gaits. Principal strains determined from the rosette signals indicate that the hoof material is loaded predominantly in compression and that the wall is distorted in a regular, repeatable manner at all speeds and gaits. Peak principal strains reach −5000 με, compared with −2800 με reported for the equine radius under similar locomotory conditions. Orientations of peak compressive strains do not correlate strongly with microstructural axes in the material. Comparison of our in vivo strain records with previous in vitro studies of the material properties of the wall shows that hoof keratin behaves as a multidirectional composite, capable of tolerating its usual operating strains in any direction. This mechanical behaviour also allows the material to withstand many unpredictable loading situations when the hoof contacts irregular substrata. An important property of the hoof wall is its ability to resist or redirect cracks. We found that the anterior aspect of the wall is loaded in biaxial compression, which assists in preventing the formation or propagation of cracks and reduces peak strain magnitudes. The strain patterns correlate well with current models of hoof distortion during weightbearing. In these models, transmission of force between the ground and the skeleton is seen as the primary cause of compression in the material. The third phalanx, which transmits the weight, is effectively suspended from the inner surface of the hoof wall. Spreading of the posterior borders (heels) of the hoof also occurs. The combination of weight-bearing, suspension of the third phalanx and heel spreading is probably responsible for the uncommon loading condition of biaxial compression on the anterior wall.

Development and differentiation in vitro of Drosophila imaginal disc cells from dissociated early embryos

Development ◽  
1975 ◽  
Vol 33 (2) ◽  
pp. 487-498
Author(s):  
Andreas Dübendorfer ◽  
Glen Shields ◽  
James H. Sang
Keyword(s):  
Imaginal Disc ◽  
Larval Instar ◽  
Cell Types ◽  
The Third ◽  
Early Embryos ◽  
Disc Cells ◽  
Development And Differentiation ◽  
Pattern Specification

Embryos of Drosophila melanogaster, 6–8 h after oviposition, were dissociated and the cells cultured in vitro. Besides larval cell types, imaginal disc cells, assembled and growing in bloated monolayered vesicles, were obtained. The cells of these vesicles become competent to differentiate adult structures when treated with α-ecdysone or ecdysterone in vitro. Recognizable patterns of the adult fly are not formed though. If metamorphosis of imaginal cell vesicles from in vitro-cultures is induced in vivo by transplantation into host larvae of various ages within the third larval instar, recognizable patterns can differentiate provided the host larva does not metamorphose prior to 2 days after transplantation. The frequency of specific patterns in the implants can be increased by providing 9 days of culture in vivo (adult host flies) before metamorphosis. Passage through the third larval instar is not essential for these cells to produce identifiable patterns since culture in adult flies alone can achieve this. The quality of the differentiated pattern is not correlated with the extent of cell proliferation in the cultured tissues. The problem of pattern specification in vitro and in vivo is discussed.

scholarly journals Mechanism of action of the third generation benzopyrans and evaluation of their broad anti-cancer activity in vitro and in vivo

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexander J. Stevenson ◽  
Eleanor I. Ager ◽  
Martina A. Proctor ◽  
Dubravka Škalamera ◽  
Andrew Heaton ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Third Generation ◽  
The Third ◽  
Anti Cancer ◽  
Cancer Activity

scholarly journals The role of retinal photoisomerase in the visual cycle of the honeybee.

1991 ◽  
Vol 97 (1) ◽  
pp. 143-165 ◽  
Author(s):  
W C Smith ◽  
T H Goldsmith
Keyword(s):  
Visual Pigment ◽  
Compound Eye ◽  
Rod Outer Segments ◽  
Visual Cycle ◽  
In Vitro Techniques ◽  
The Third ◽  
Isomerization Processes

The compound eye of the honeybee has previously been shown to contain a soluble retinal photoisomerase which, in vitro, is able to catalyze stereospecifically the photoconversion of all-trans retinal to 11-cis retinal. In this study we combine in vivo and in vitro techniques to demonstrate how the retinal photoisomerase is involved in the visual cycle, creating 11-cis retinal for the generation of visual pigment. Honeybees have approximately 2.5 pmol/eye of retinal associated with visual pigments, but larger amounts (4-12 pmol/eye) of both retinal and retinol bound to soluble proteins. When bees are dark adapted for 24 h or longer, greater than 80% of the endogenous retinal, mostly in the all-trans configuration, is associated with the retinal photoisomerase. On exposure to blue light the retinal is isomerized to 11-cis, which makes it available to an alcohol dehydrogenase. Most of it is then reduced to 11-cis retinol. The retinol is not esterified and remains associated with a soluble protein, serving as a reservoir of 11-cis retinoid available for renewal of visual pigment. Alternatively, 11-cis retinal can be transferred directly to opsin to regenerate rhodopsin, as shown by synthesis of rhodopsin in bleached frog rod outer segments. This retinaldehyde cycle from the honeybee is the third to be described. It appears very similar to the system in another group of arthropods, flies, and differs from the isomerization processes in vertebrates and cephalopod mollusks.

Does endotoxaemia contribute to osteoarthritis in obese patients?

2012 ◽  
Vol 123 (11) ◽  
pp. 627-634 ◽  
Author(s):  
David Metcalfe ◽  
Alison L. Harte ◽  
Mina Olga Aletrari ◽  
Nasser M. Al Daghri ◽  
Dara Al Disi ◽  
...  
Keyword(s):  
Inflammatory Mediators ◽  
Weight Bearing ◽  
Innate Immune ◽  
Low Grade ◽  
Obese Patients ◽  
Markers Of Inflammation ◽  
Gut Mucosa ◽  
Biomechanical Factors

OA (osteoarthritis) is a degenerative condition associated with obesity. A number of metabolic explanations have been proposed to explain the association between obesity and OA in non-weight-bearing joints; however, none of these hypotheses have been demonstrated empirically. In the present Hypothesis article, we recognize that obesity is associated with compromised gut mucosa, translocation of microbiota and raised serum LPS (lipopolysaccharide). The consequent activation of the innate immune response leads to increased serum titres of inflammatory mediators in obese patients, with both local and systemic markers of inflammation associated with onset and progression of OA. Furthermore, a number of workers have shown that articular cartilage repair is impaired by a range of inflammatory mediators, both in vitro and in vivo. We propose that metabolic endotoxaemia, caused by impaired gastric mucosa and low-grade chronic inflammation, may contribute to the onset and progression of OA in obese patients. This may account for the association between obesity and OA at non-weight-bearing joints which cannot be explained by biomechanical factors.

Hybrid Chitosan Membranes Tested in Sheep for Guided Tissue Regeneration

2007 ◽  
Vol 361-363 ◽  
pp. 1265-1268 ◽  
Author(s):  
P.P. Cortez ◽  
Yuki Shirosaki ◽  
C.M. Botelho ◽  
M.J. Simões ◽  
F. Gartner ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Tissue Regeneration ◽  
Chitosan Solution ◽  
Clinical Applications ◽  
Histological Evaluation ◽  
Sheep Model ◽  
The Third ◽  
Chitosan Membranes

Previous in vitro studies confirmed an improved cytocompatibility of chitosan-silicate hybrid membranes over chitosan membranes. The main goal of this study was to assess the in vivo histocompatibility of both membranes through subcutaneous implantations at different time periods, 1 week, 1, 2 and 3 months, using a sheep model. Chitosan membranes elicited an exuberant inflammatory response and were consequently rejected. The hybrid chitosan membranes were not rejected and the degree of inflammatory response decreased gradually until the third month of implantation. Histological evaluation also showed that these membranes can be resorbed in vivo. This study demonstrates that the incorporation of silicate into the chitosan solution improves its histocompatibility, indicating that the hybrid chitosan-silicate membranes are suitable candidates to be used in clinical applications.

Effect of the In Vitro Boundary Conditions on the Surface Strain Experienced by the Vertebral Body in the Elastic Regime

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Valentina Danesi ◽  
Paolo Erani ◽  
Nicola Brandolini ◽  
Mateusz M. Juszczyk ◽  
Luca Cristofolini
Keyword(s):  
Boundary Conditions ◽  
Axial Loading ◽  
Surface Strain ◽  
Strain Gauges ◽  
Nondestructive Tests ◽  
Elastic Regime ◽  
Vertebral Strength ◽  
Strain Magnitude ◽  
Principal Strains

The vertebral strength and strain can be assessed in vitro by both using isolated vertebrae and sets of three adjacent vertebrae (the central one is loaded through the disks). Our goal was to elucidate if testing single-vertebra-specimens in the elastic regime provides different surface strains to three-vertebrae-segments. Twelve three-vertebrae sets were extracted from thoracolumbar human spines. To measure the principal strains, the central vertebra of each segment was prepared with eight strain-gauges. The sets were tested mechanically, allowing comparison of the surface strains between the two boundary conditions: first when the same vertebra was loaded through the disks (three-vertebrae-segment) and then with the endplates embedded in cement (single-vertebra). They were all subjected to four nondestructive tests (compression, traction, torsion clockwise, and counterclockwise). The magnitude of principal strains differed significantly between the two boundary conditions. For axial loading, the largest principal strains (along vertebral axis) were significantly higher when the same vertebra was tested isolated compared to the three-vertebrae-segment. Conversely, circumferential strains decreased significantly in the single vertebrae compared to the three-vertebrae-segment, with some variations exceeding 100% of the strain magnitude, including changes from tension to compression. For torsion, the differences between boundary conditions were smaller. This study shows that, in the elastic regime, when the vertebra is loaded through a cement pot, the surface strains differ from when it is loaded through the disks. Therefore, when single vertebrae are tested, surface strain should be taken with caution.

Introduction to the complement system

1984 ◽  
Vol 306 (1129) ◽  
pp. 279-281 ◽  
Keyword(s):  
Humoral Immunity ◽  
Complement System ◽  
Bacterial Infections ◽  
Cross Linking ◽  
Complement Components ◽  
The Third ◽  
Effector Mechanism ◽  
The Complement System

Complement is the essential effector mechanism in humoral immunity to infection. Combination of antibody with antigen causes cross-linking, leading to precipitation of soluble antigens and agglutination of particular antigens, but no more. Unless complement is also present, agglutinated microorganisms can, in appropriate media in vitro grow out and form as lethal a culture as if not reacted with antibody. That this is also true in vivo is apparent from experience with patients with inherited deficiencies in complement components. The pattern is complex because of the presence of two pathways of activation, but in the rare cases of deficiency of the third component, C3, which is central to both pathways, the individuals are susceptible to repeated bacterial infections similar to aggammaglobulinaemics who are unable to synthesize antibodies. Both antibodies and complement are essential for effective humoral immunity.

scholarly journals The toxofilin–actin–PP2C complex of Toxoplasma: identification of interacting domains

2007 ◽  
Vol 401 (3) ◽  
pp. 711-719 ◽  
Author(s):  
Gaelle Jan ◽  
Violaine Delorme ◽  
Violaine David ◽  
Celine Revenu ◽  
Angelita Rebollo ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Actin Filaments ◽  
Function Analysis ◽  
Protozoan Parasite ◽  
Actin Binding ◽  
Protein Protein Interactions ◽  
The Third ◽  
Parasite Motility

Toxofilin is a 27 kDa protein isolated from the human protozoan parasite Toxoplasma gondii, which causes toxoplasmosis. Toxofilin binds to G-actin, and in vitro studies have shown that it controls elongation of actin filaments by sequestering actin monomers. Toxofilin affinity for G-actin is controlled by the phosphorylation status of its Ser53, which depends on the activities of a casein kinase II and a type 2C serine/threonine phosphatase (PP2C). To get insights into the functional properties of toxofilin, we undertook a structure–function analysis of the protein using a combination of biochemical techniques. We identified a domain that was sufficient to sequester G-actin and that contains three peptide sequences selectively binding to G-actin. Two of these sequences are similar to sequences present in several G- and F-actin-binding proteins, while the third appears to be specific to toxofilin. Additionally, we identified two toxofilin domains that interact with PP2C, one of which contains the Ser53 substrate. In addition to characterizing the interacting domains of toxofilin with its partners, the present study also provides information on an in vivo-based approach to selectively and competitively disrupt the protein–protein interactions that are important to parasite motility.

scholarly journals Gamma Irradiation Treatment of Bactrocera dorsalis Hendel (Diptera: Tephritidae) in Snake Fruit

2019 ◽  
Vol 23 (2) ◽  
pp. 242
Author(s):  
Novi Kusumaning Astuti ◽  
Suputa Suputa ◽  
Nugroho Susetyo Putra ◽  
Murni Indarwatmi
Keyword(s):  
Gamma Ray ◽  
Fruit Fly ◽  
Bactrocera Dorsalis ◽  
The Third ◽  
Minimum Dose ◽  
Irradiation Treatment ◽  
Gamma Ray Irradiation

Snake fruit (Salacca zalacca) is a unique fruit and it has decadent prospects to be developed as an export commodity. Nevertheless, oriental fruit fly, Bactrocera dorsalis Hendel seems to decrease the quantity and quality of this fruit. On the other side, irradiation has been developed as a standard quarantine treatment to disinfest fruit fly on fruit. The objective of this research was to determine impact of irradiation by Cobalt-60 gamma-ray on the development and survivorship of eggs and the third instar of fruitfly larvae using in-vitro and in-vivo approaches and minimum dose of Cobalt-60 gamma rays applied for snake fruit. Six doses of gamma-ray, i.e. 0 (control), 25, 50, 75, 100, 125 and 150 Gy were used in this experiment. The results showed that Cobalt-60 disturbed development and survivor rate of B. dorsalis. The development of eggs into pupa was failed when treated with Cobalt-60 at any doses, while the third instar larvae failed to become adult when irradiated with 75, 100 and 150 Gy of gamma-ray. The impacts were increased with the increment of dose. Furthermore, impact of gamma-ray irradiation was greater on eggs compared to the third instar of larvae. The minimum dose of irradiation to prevent adults emerge was 118 Gy.

scholarly journals ANTIPSYCHOTICS: FROM THE FIRST TO THE THIRD GENERATION

2020 ◽  
Author(s):  
Nataliia N. Petrova ◽  
Alexander G. Sofronov
Keyword(s):  
Comparative Analysis ◽  
Negative Symptoms ◽  
Third Generation ◽  
Antipsychotic Therapy ◽  
Persistent Symptoms ◽  
D3 Receptors ◽  
The Third ◽  
Personalized Approach

The review is devoted to comparative analysis of antipsychotics of three generations. When writing the review, a systematic search in the databases PubMed, Medline, Elsevier was carried out, a simple filter for keywords was used. Pharmacological and clinical issues of antipsychotic therapy were considered, the mechanisms of action of antipsychotics of different generations were revealed. Current trends in the development of approaches to the therapy of schizophrenia and the concept of atypicality of antipsychotics were discussed. A comparative analysis of indications for use, tolerance (safety of use) and efficacy of various antipsychotic drugs with an emphasis on the effect on negative (primary, persistent) symptoms has been conducted. The hypothesis underlying new approaches to the therapy of schizophrenia, based on the effect on dopamine autoreceptors, consisting of a high density of D2 and low density of D3 receptors, has been presented. It has been shown that antipsychotics of the third generation open up new possibilities in the therapy of psychosis within the framework of a personalized approach in psychiatry with the achievement of functional recovery of patients. The characteristics of the drugs representatives of the third generation of antipsychotics aripiprazole and cariprazine were given. The uniqueness of cariprazine as the only drug that inhibits D3 receptors in vitro, as well as in vivo in patients with schizophrenia was emphasized. The data of evidence-based studies of the effectiveness of cariprazine in the treatment of negative, including predominant negative symptoms were presented.

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