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Author Meershoek, L.S.; Schamhardt, H.C.; Roepstorff, L.; Johnston, C.
Title Forelimb tendon loading during jump landings and the influence of fence height Type Journal Article
Year 2001 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 33 Pages 6-10
Keywords Animals; Biomechanics; Forelimb/injuries/physiology; Horses/injuries/*physiology; Lameness, Animal/etiology; Ligaments, Articular/*physiology; Locomotion/*physiology; Physical Conditioning, Animal; Tendon Injuries/complications/physiopathology/veterinary; Tendons/*physiology; Weight-Bearing/physiology
Abstract Lameness in athletic horses is often caused by forelimb tendon injuries, especially in the interosseus tendon (TI) and superficial digital flexor tendon (SDF), but also in the accessory ligament (AL) of the deep digital flexor tendon (DDF). In an attempt to explain the aetiology of these injuries, the present study investigated the loading of the tendons during landing after a jump. In jumping horses, the highest forces can be expected in the trailing limb during landing. Therefore, landing kinematics and ground reaction forces of the trailing forelimb were measured from 6 horses jumping single fences with low to medium heights of 0.80, 1.00 and 1.20 m. The tendon forces were calculated using inverse dynamics and an in vitro model of the lower forelimb. Calculated peak forces in the TI, SDF and DDF + AL during landing were 15.8, 13.9 and 11.7 kN respectively. The relative loading of the tendons (landing forces compared with failure forces determined in a separate study) increased from DDF to TI to SDF and was very high in SDF. This explains the low injury incidence of the DDF and the high injury incidence of the SDF. Fence height substantially influenced SDF forces, whereas it hardly influenced TI forces and did not influence AL strain. Reduction of fence height might therefore limit the risks for SDF injuries, but not for TI and AL injuries.
Address Department of Veterinary Anatomy and Physiology, Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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Notes PMID:11721571 Approved no
Call Number Equine Behaviour @ team @ Serial 3786
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Author Meershoek, L.S.; Roepstorff, L.; Schamhardt, H.C.; Johnston, C.; Bobbert, M.F.
Title Joint moments in the distal forelimbs of jumping horses during landing Type Journal Article
Year 2001 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 33 Issue 4 Pages 410-415
Keywords Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Horses/*physiology; Joints/*physiology; Physical Conditioning, Animal; Tendons/*physiology; Weight-Bearing
Abstract Tendon injuries are an important problem in athletic horses and are probably caused by excessive loading of the tendons during demanding activities. As a first step towards understanding these injuries, the tendon loading was quantified during jump landings. Kinematics and ground reaction forces were collected from the leading and trailing forelimbs of 6 experienced jumping horses. Joint moments were calculated using inverse dynamic analysis. It was found that the variation of movement and loading patterns was small, both within and between horses. The peak flexor joint moments in the coffin and fetlock joints were larger in the trailing limb (-0.62 and -2.44 Nm/kg bwt, respectively) than in the leading limb (-0.44 and -1.93 Nm/kg bwt, respectively) and exceeded literature values for trot by 82 and 45%. Additionally, there was an extensor coffin joint moment in the first half of the stance phase of the leading limb (peak value 0.26+/-0.18 Nm/kg bwt). From these results, it was concluded that the loading of the flexor tendons during landing was higher in the trailing than in the leading limb and that there was an unexpected loading of the extensor tendon in the leading limb.
Address Department of Veterinary Anatomy and Physiology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:11469776 Approved no
Call Number Equine Behaviour @ team @ Serial 3787
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Author Abbruzzetti, S.; Viappiani, C.; Small, J.R.; Libertini, L.J.; Small, E.W.
Title Kinetics of histidine deligation from the heme in GuHCl-unfolded Fe(III) cytochrome C studied by a laser-induced pH-jump technique Type Journal Article
Year 2001 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 123 Issue 27 Pages 6649-6653
Keywords Animals; *Bacterial Proteins; Cytochrome c Group/*chemistry; Guanidine/*chemistry; Heme/*chemistry; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; *Lasers; Ligands; Protein Folding
Abstract We have developed an instrumental setup that uses transient absorption to monitor protein folding/unfolding processes following a laser-induced, ultrafast release of protons from o-nitrobenzaldehyde. The resulting increase in [H(+)], which can be more than 100 microM, is complete within a few nanoseconds. The increase in [H(+)] lowers the pH of the solution from neutrality to approximately 4 at the highest laser pulse energy used. Protein structural rearrangements can be followed by transient absorption, with kinetic monitoring over a broad time range (approximately 10 ns to 500 ms). Using this pH-jump/transient absorption technique, we have examined the dissociation kinetics of non-native axial heme ligands (either histidine His26 or His33) in GuHCl-unfolded Fe(III) cytochrome c (cyt c). Deligation of the non-native ligands following the acidic pH-jump occurs as a biexponential process with different pre-exponential factors. The pre-exponential factors markedly depend on the extent of the pH-jump, as expected from differences in the pK(a) values of His26 and His33. The two lifetimes were found to depend on temperature but were not functions of either the magnitude of the pH-jump or the pre-pulse pH of the solution. The activation energies of the deligation processes support the suggestion that GuHCl-unfolded cyt c structures with non-native histidine axial ligands represent kinetic traps in unfolding.
Address Dipartimento di Fisica, Universita di Parma, Istituto Nazionale per la Fisica della Materia, 43100 Parma, Italy
Corporate Author (up) Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 0002-7863 ISBN Medium
Area Expedition Conference
Notes PMID:11439052 Approved no
Call Number Equine Behaviour @ team @ Serial 3788
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Author Gulotta, M.; Gilmanshin, R.; Buscher, T.C.; Callender, R.H.; Dyer, R.B.
Title Core formation in apomyoglobin: probing the upper reaches of the folding energy landscape Type Journal Article
Year 2001 Publication Biochemistry Abbreviated Journal Biochemistry
Volume 40 Issue 17 Pages 5137-5143
Keywords Animals; Apoproteins/*chemistry; Computer Simulation; Horses; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; *Protein Folding; Protein Structure, Secondary; Protein Structure, Tertiary; Spectrometry, Fluorescence/instrumentation/methods; Thermodynamics; Tryptophan/chemistry
Abstract An acid-destabilized form of apomyoglobin, the so-called E state, consists of a set of heterogeneous structures that are all characterized by a stable hydrophobic core composed of 30-40 residues at the intersection of the A, G, and H helices of the protein, with little other secondary structure and no other tertiary structure. Relaxation kinetics studies were carried out to characterize the dynamics of core melting and formation in this protein. The unfolding and/or refolding response is induced by a laser-induced temperature jump between the folded and unfolded forms of E, and structural changes are monitored using the infrared amide I' absorbance at 1648-1651 cm(-1) that reports on the formation of solvent-protected, native-like helix in the core and by fluorescence emission changes from apomyoglobin's Trp14, a measure of burial of the indole group of this residue. The fluorescence kinetics data are monoexponential with a relaxation time of 14 micros. However, infrared kinetics data are best fit to a biexponential function with relaxation times of 14 and 59 micros. These relaxation times are very fast, close to the limits placed on folding reactions by diffusion. The 14 micros relaxation time is weakly temperature dependent and thus represents a pathway that is energetically downhill. The appearance of this relaxation time in both the fluorescence and infrared measurements indicates that this folding event proceeds by a concomitant formation of compact secondary and tertiary structures. The 59 micros relaxation time is much more strongly temperature dependent and has no fluorescence counterpart, indicating an activated process with a large energy barrier wherein nonspecific hydrophobic interactions between helix A and the G and H helices cause some helix burial but Trp14 remains solvent exposed. These results are best fit by a multiple-pathway kinetic model when U collapses to form the various folded core structures of E. Thus, the results suggest very robust dynamics for core formation involving multiple folding pathways and provide significant insight into the primary processes of protein folding.
Address Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-2960 ISBN Medium
Area Expedition Conference
Notes PMID:11318635 Approved no
Call Number Equine Behaviour @ team @ Serial 3789
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Author Abbruzzetti, S.; Crema, E.; Masino, L.; Vecli, A.; Viappiani, C.; Small, J.R.; Libertini, L.J.; Small, E.W.
Title Fast events in protein folding: structural volume changes accompanying the early events in the N-->I transition of apomyoglobin induced by ultrafast pH jump Type Journal Article
Year 2000 Publication Biophysical Journal Abbreviated Journal Biophys J
Volume 78 Issue 1 Pages 405-415
Keywords Animals; Apoproteins/*chemistry; Horses; *Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Protein Structure, Secondary; Spectrometry, Fluorescence
Abstract Ultrafast, laser-induced pH jump with time-resolved photoacoustic detection has been used to investigate the early protonation steps leading to the formation of the compact acid intermediate (I) of apomyoglobin (ApoMb). When ApoMb is in its native state (N) at pH 7.0, rapid acidification induced by a laser pulse leads to two parallel protonation processes. One reaction can be attributed to the binding of protons to the imidazole rings of His24 and His119. Reaction with imidazole leads to an unusually large contraction of -82 +/- 3 ml/mol, an enthalpy change of 8 +/- 1 kcal/mol, and an apparent bimolecular rate constant of (0.77 +/- 0.03) x 10(10) M(-1) s(-1). Our experiments evidence a rate-limiting step for this process at high ApoMb concentrations, characterized by a value of (0. 60 +/- 0.07) x 10(6) s(-1). The second protonation reaction at pH 7. 0 can be attributed to neutralization of carboxylate groups and is accompanied by an apparent expansion of 3.4 +/- 0.2 ml/mol, occurring with an apparent bimolecular rate constant of (1.25 +/- 0.02) x 10(11) M(-1) s(-1), and a reaction enthalpy of about 2 kcal/mol. The activation energy for the processes associated with the protonation of His24 and His119 is 16.2 +/- 0.9 kcal/mol, whereas that for the neutralization of carboxylates is 9.2 +/- 0.9 kcal/mol. At pH 4.5 ApoMb is in a partially unfolded state (I) and rapid acidification experiments evidence only the process assigned to carboxylate protonation. The unusually large contraction and the high energetic barrier observed at pH 7.0 for the protonation of the His residues suggests that the formation of the compact acid intermediate involves a rate-limiting step after protonation.
Address Dipartimento di Fisica, Universita di Parma, 43100 Parma, Italia
Corporate Author (up) Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3495 ISBN Medium
Area Expedition Conference
Notes PMID:10620304 Approved no
Call Number Equine Behaviour @ team @ Serial 3792
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Author Grandin, T.
Title Safe handling of large animals Type Journal Article
Year 1999 Publication Occupational Medicine (Philadelphia, Pa.) Abbreviated Journal Occup Med
Volume 14 Issue 2 Pages 195-212
Keywords Accidents, Occupational/*prevention & control/statistics & numerical data; Aggression/physiology/psychology; Animal Husbandry/*methods; Animals; *Behavior, Animal/physiology; Cattle; Conditioning, Operant/physiology; Crowding/psychology; Fear/physiology/psychology; Female; *Horses/physiology/psychology; Humans; Male; Movement/physiology; *Occupational Health; Risk Factors; *Ruminants/physiology/psychology
Abstract The major causes of accidents with cattle, horses, and other grazing animals are: panic due to fear, male dominance aggression, or the maternal aggression of a mother protecting her newborn. Danger is inherent when handling large animals. Understanding their behavior patterns improves safety, but working with animals will never be completely safe. Calm, quiet handling and non-slip flooring are beneficial. Rough handling and excessive use of electric prods increase chances of injury to both people and animals, because fearful animals may jump, kick, or rear. Training animals to voluntarily cooperate with veterinary procedures reduces stress and improves safety. Grazing animals have a herd instinct, and a lone, isolated animal can become agitated. Providing a companion animal helps keep an animal calm.
Address Department of Animal Science, Colorado State University, Fort Collins 80526, USA
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ISSN 0885-114X ISBN Medium
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Notes PMID:10329901 Approved no
Call Number Equine Behaviour @ team @ Serial 3793
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Author Birch, H.L.; Bailey, A.J.; Goodship, A.E.
Title Macroscopic 'degeneration' of equine superficial digital flexor tendon is accompanied by a change in extracellular matrix composition Type Journal Article
Year 1998 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 30 Issue 6 Pages 534-539
Keywords Animals; Collagen/analysis; DNA/analysis; Extracellular Matrix/*chemistry; Glycosaminoglycans/analysis; Horses/injuries/*physiology; Immunohistochemistry; Rupture/veterinary; Tendon Injuries/metabolism/pathology/veterinary; Tendons/chemistry/*pathology; Water/analysis
Abstract Injuries to the superficial digital flexor tendon are common in horses required to gallop and jump at speed. Partial rupture of this tendon usually occurs in the central core of the midmetacarpal region and may be preceded by localised degenerative changes. Post mortem examination of apparently normal equine flexor tendons has revealed an abnormal macroscopic appearance in the central core, characterised by a reddish discolouration. We have previously shown that there is also physical damage to the collagen fibres. In the present study we tested the hypothesis that the abnormal appearance is accompanied by changes in the composition of the extracellular matrix of the tendon. Biochemical analysis of the extracellular matrix demonstrated an increase in total sulphated glycosaminoglycan content, increase in the proportion of type III collagen and decrease in collagen linked fluorescence in the central core of 'degenerated' tendons relative to tissue from the peripheral region of the same tendon. Dry matter content and total collagen content were not significantly different between tendon zones or normal and 'degenerated' tendons. These changes suggest a change in cell metabolism and matrix turnover in the central core of the tendon and are likely to contribute to a decrease in mechanical properties in this part of the tendon, predisposing to the characteristic partial rupture of the tendon.
Address Veterinary Basic Sciences, Royal Veterinary College, North Mymms, Hatfield, UK
Corporate Author (up) Thesis
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Series Editor Series Title Abbreviated Series Title
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ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:9844973 Approved no
Call Number Equine Behaviour @ team @ Serial 3794
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Author Gilmanshin, R.; Callender, R.H.; Dyer, R.B.
Title The core of apomyoglobin E-form folds at the diffusion limit Type Journal Article
Year 1998 Publication Nature Structural Biology Abbreviated Journal Nat Struct Biol
Volume 5 Issue 5 Pages 363-365
Keywords Animals; Apoproteins/*chemistry; Diffusion; Horses; Myoglobin/*chemistry; *Protein Folding; Spectroscopy, Fourier Transform Infrared; Temperature
Abstract The E-form of apomyoglobin has been characterized using infrared and fluorescence spectroscopies, revealing a compact core with native like contacts, most probably consisting of 15-20 residues of the A, G and H helices of apomyoglobin. Fast temperature-jump, time-resolved infrared measurements reveal that the core is formed within 96 micros at 46 degrees C, close to the diffusion limit for loop formation. Remarkably, the folding pathway of the E-form is such that the formation of a limited number of native-like contacts is not rate limiting, or that the contacts form on the same time scale expected for diffusion controlled loop formation.
Address
Corporate Author (up) Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1072-8368 ISBN Medium
Area Expedition Conference
Notes PMID:9586997 Approved no
Call Number Equine Behaviour @ team @ Serial 3795
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Author Barrey, E.; Galloux, P.
Title Analysis of the equine jumping technique by accelerometry Type Journal Article
Year 1997 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 23 Pages 45-49
Keywords *Acceleration; Analysis of Variance; Animals; Forelimb/physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Movement/physiology; Time Factors
Abstract The purpose of this study was to demonstrate the relationships between jumping technique and dorsoventral acceleration measured at the sternum. Eight saddle horses of various jumping abilities competed on a selective experimental show jumping course including 14 obstacles. An accelerometric belt fastened onto the thorax continuously measured the dorsoventral acceleration during the course. At each jump, 11 locomotor parameters (acceleration peaks, durations and stride frequency) were obtained from the dorsoventral acceleration-time curves. The type of obstacle significantly influenced the hindlimb acceleration peak at take-off and the landing acceleration peak (P<0.01). The poor jumpers exhibited a higher mean forelimb acceleration peak at take-off, a higher forelimb/hindlimb ratio between peaks of acceleration (F/H), and a lower approach stride frequency than good jumpers. Knocking over an obstacle was significantly associated with a low hindlimb acceleration peak at take-off and a high F/H ratio (P<0.01). In order to observe the continuous changes in the frequency domain of the dorsoventral acceleration during the approach and take-off phase, a Morlet's wavelet analysis was computed for each horse jumping over a series of 3 vertical obstacles. Different patterns of time-frequency images obtained by wavelet analysis were found when the horse either knocked over a vertical obstacle or cleared it. In the latter case, the image pattern showed an instantaneous increase in stride frequency at the end of the approach phase, and a marked energy content in the middle frequency range at take-off.
Address INRA Station de Genetique Quantitative et Appliquee, Groupe cheval, Jouy-en-Josas, France
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Notes PMID:9354288 Approved no
Call Number Equine Behaviour @ team @ Serial 3796
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Author Galloux, P.; Barrey, E.
Title Components of the total kinetic moment in jumping horses Type Journal Article
Year 1997 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 23 Pages 41-44
Keywords Algorithms; Animals; Exertion/*physiology; Female; Gravitation; Horses/*physiology; Kinetics; Locomotion/*physiology; Male; Models, Biological; Movement/*physiology; Video Recording
Abstract Thirty horses were filmed with a panning camera operating at 50 frames/s as they jumped over a 1.20 x 1.20 m fence. The markers of 9 joints on the horse and 7 joints on the rider were tracked in 2D with the TrackEye system. The centre of gravity and moment of inertia of each segment were calculated using a geometric algorithm and a cylindric model, respectively. The kinetic moment of each part of the horse was calculated after filtering, and resampling of data. This method showed the relative contribution of each body segment to the body overall rotation during the take-off, jump and landing phases. It was found that the trunk, hindlimbs and head-neck had the greatest influence. The coordination between the motion of the body segments allowed the horse to control its angular speed of rotation over the fence. This remained nearly constant during the airborne phase (120 +/- 5 degrees/s). During the airborne phase, the kinetic moment was constant because its value was equal to the moment of the external forces (722 +/- 125 kg x m2/s).
Address Ecole Nationale d'Equitation, Terrefort, Saumur, France
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Notes PMID:9354287 Approved no
Call Number Equine Behaviour @ team @ Serial 3797
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