|   | 
Details
   web
Records
Author (down) Steinhoff, H.J.; Schrader, J.; Schlitter, J.
Title Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals Type Journal Article
Year 1992 Publication Biochimica et Biophysica Acta Abbreviated Journal Biochim Biophys Acta
Volume 1121 Issue 3 Pages 269-278
Keywords Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry
Abstract Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
Address Institut fur Biophysik, Ruhr-Universitat Bochum, Germany
Corporate Author 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 0006-3002 ISBN Medium
Area Expedition Conference
Notes PMID:1627604 Approved no
Call Number Equine Behaviour @ team @ Serial 3800
Permanent link to this record
 

 
Author (down) Steinhoff, H.J.; Lieutenant, K.; Redhardt, A.
Title Conformational transition of aquomethemoglobin: intramolecular histidine E7 binding reaction to the heme iron in the temperature range between 220 K and 295 K as seen by EPR and temperature-jump measurements Type Journal Article
Year 1989 Publication Biochimica et Biophysica Acta Abbreviated Journal Biochim Biophys Acta
Volume 996 Issue 1-2 Pages 49-56
Keywords Animals; Electron Spin Resonance Spectroscopy; Heme; Histidine; Horses; Humans; Hydrogen-Ion Concentration; Methemoglobin/*ultrastructure; Motion; Protein Conformation; Temperature; Thermodynamics; Water
Abstract Temperature-dependent EPR and temperature-jump measurements have been carried out, in order to examine the high-spin to low-spin transition of aquomethemogobin (pH 6.0). Relaxation rates and equilibrium constants could be determined as a function of temperature. As a reaction mechanism for the high-spin to low-spin transition, the binding of N epsilon of His E7 to the heme iron had been proposed; the same mechanism had been suggested for the ms-effect, found in temperature-jump experiments on aquomethemoglobin. A comparison of the thermodynamic quantities, deduced form the measurements in this paper, gives evidence that indeed the same reaction is investigated in both cases. Our results and most of the findings of earlier studies on the spin-state transitions of aquomethemoglobin, using susceptibility, optical, or EPR measurements, can be explained by the transition of methemoglobin with H2O as ligand (with high-spin state at all temperatures) and methemoglobin with ligand N epsilon of His E7 (with a low-spin ground state). Thermal fluctuations of large amplitude have to be postulated for the reaction to take place, so this reaction may be understood as a probe for the study of protein dynamics.
Address Institut fur Biophysik, Ruhr-Universitat Bochum, F.R.G
Corporate Author 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 0006-3002 ISBN Medium
Area Expedition Conference
Notes PMID:2544230 Approved no
Call Number Equine Behaviour @ team @ Serial 3803
Permanent link to this record
 

 
Author (down) Steinhoff, H.J.
Title A continuous wave laser T-jump apparatus and its application to chemical reactions in hemoglobin single crystals Type Journal Article
Year 1988 Publication Journal of Biochemical and Biophysical Methods Abbreviated Journal J Biochem Biophys Methods
Volume 15 Issue 6 Pages 319-330
Keywords Animals; Chemistry; Crystallization; *Heat; *Hemoglobins; Horses/blood; *Lasers; Methemoglobin; Solutions; Thermodynamics; Thiocyanates
Abstract A laser temperature jump apparatus is constructed where the T-jump is achieved by means of the direct absorption of continuous laser radiation of low intensity by a solid sample. The final temperature in the irradiated volume element is reached when the absorbed radiation power equals the dissipation of heat by heat conduction. The time range from the beginning of irradiation to the stationary state depends on the geometry of the irradiated volume element and is less than 10 ms. The heating laser beam is simultaneously used to detect the relaxation to the new chemical equilibrium in the sample. Relaxation processes with relaxation rates between 10(2) s-1 and less than 10(-3) s-1 on samples with volumes less than 10(-3) mm3 may be investigated using this T-jump method. One application of this method is the determination of reaction rates of ligand reactions in hemoglobin single crystals. Rate constants obtained for the reaction of thiocyanate with crystallized horse methemoglobin are presented.
Address Institut fur Biophysik, Ruhr-Universitat Bochum, F.R.G
Corporate Author 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 0165-022X ISBN Medium
Area Expedition Conference
Notes PMID:3379245 Approved no
Call Number Equine Behaviour @ team @ Serial 3804
Permanent link to this record
 

 
Author (down) Staniar, W.B.; Kronfeld, D.S.; Hoffman, R.M.; Wilson, J.A.; Harris, P.A.
Title Weight prediction from linear measures of growing Thoroughbreds Type Journal Article
Year 2004 Publication Equine veterinary journal Abbreviated Journal Equine Vet J
Volume 36 Issue 2 Pages 149-154
Keywords Animal Nutrition Physiology; Animals; Biometry; Body Weight/*physiology; Female; Horses/*anatomy & histology/*growth & development; Male; Mathematics; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity
Abstract REASON FOR PERFORMING STUDY: Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth. OBJECTIVE: To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs). METHODS: Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals. RESULTS: Accuracy and precision were maximised with a broken line relating calculated volumes (V(t + l)) to measured weights. Use of the broken line is a 2 step process. V(t + l) is calculated from linear measures (m) of girth (G), carpus circumference (C), and length of body (B) and left forelimb (F). V(t + I) = ([G2 x B] + 4[C2 x F]) 4pi. If V(t + l) < 0.27 m3, weight is estimated: Weight (kg) = V(t + l) x 1093. If V(t + l) > or = 0.27 m3: Weight (kg) = V(t + l) x 984 + 24. The broken line was more accurate and precise than 3 published equations predicting the weight of young TBs. CONCLUSIONS: Estimation of weight using morphometric equations requires attention to temporal changes in body shape and density; hence, a broken line is needed. Including calculated leg volume in the broken line model is another contributing factor to improvement in predictive capability. POTENTIAL RELEVANCE: The broken line maximises its value to equine professionals through its accuracy, precision and convenience.
Address Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0306, USA
Corporate Author 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:15038438 Approved no
Call Number Serial 1806
Permanent link to this record
 

 
Author (down) Stahlbaum, C.C.; Houpt, K.A.
Title The role of the Flehmen response in the behavioral repertoire of the stallion Type Journal Article
Year 1989 Publication Physiology & behavior Abbreviated Journal Physiol. Behav.
Volume 45 Issue 6 Pages 1207-1214
Keywords Animals; Behavior, Animal/*physiology; Circadian Rhythm; Discrimination (Psychology)/physiology; Estrus; Feces; Female; Horses/*physiology; Male; Sexual Behavior, Animal/*physiology; Smell/*physiology; Taste/physiology; Urine
Abstract The role of the Flehmen response in equine behavior was investigated under field and laboratory conditions. In Experiment 1, a field study made of five stallions on pasture with between three and eighteen mares each during the season indicated the following: 1) The Flehmen response was most frequently preceded by nasal, rather than oral, investigation of substances; 2) The stallions' rate of Flehmen varied with the estrous cycles of the mares; 3) The rate of Flehmen response did not show a variation with time of day; and 4) The Flehmen response was most frequently followed by marking behaviors rather than courtship behaviors. The results suggest that the Flehmen response is not an immediate component of sexual behavior, e.g., courtship of the stallion but may be involved in the overall monitoring of the mare's estrous cycle. Therefore the Flehmen response may contribute to the chemosensory priming of the stallion for reproduction. In Experiment 2 stallions were presented with urine or feces of mares in various stages of the reproductive cycle as well as with their own or other males' urine or feces. The occurrence of sniffing and Flehmen was used to determine the discriminatory ability of the stallions. Stallions can differentiate the sex of a horse on the basis of its feces alone, but cannot differentiate on the basis of urine. This ability may explain the function of fecal marking behavior of stallions.
Address New York State College of Veterinary Medicine, Cornell University, Ithaca 14853
Corporate Author 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 0031-9384 ISBN Medium
Area Expedition Conference
Notes PMID:2813545 Approved no
Call Number refbase @ user @ Serial 44
Permanent link to this record
 

 
Author (down) Stadler, P.; Rewel, A.; Deegen, E.
Title [M-mode echocardiography in dressage horses, class S jumping horses and untrained horses] Type Journal Article
Year 1993 Publication Zentralblatt fur Veterinarmedizin. Reihe A Abbreviated Journal Zentralbl Veterinarmed A
Volume 40 Issue 4 Pages 292-306
Keywords Animals; Echocardiography/*veterinary; Female; Heart Septum/ultrasonography; Heart Ventricles/ultrasonography; Horses/*anatomy & histology; Male; *Physical Conditioning, Animal; Reference Values
Abstract Heart structures of 45 warmblooded horses were measured by M-mode-echocardiography. The current training level of 15 dressage horses (group I) and 15 show-jumping horses (group II) was category “S”. In the third group were 15 untrained horses. Four standardized transducer positions were determined for the m-mode echobeam, calibrated according to the two-dimensional real time technique. End systolic and end diastolic diameters of left ventricle, right ventricle, aortic root, interventricular septum and left ventricular wall, as well as motion pattern of heart wall, mitral valve and aortic valve of all horses were measured. The dressage horses showed a significant thickening of interventricular septum and left-ventricular wall compared with the show-jumping horses and the untrained horses. The end diastolic left ventricle diameter of the show-jumping horses was significantly larger than in the other groups. Compared to the untrained horses the show-jumping horses showed a significantly larger end systolic left ventricular wall diameter measured at the level of papillary muscle. It can be concluded, that an increase in heart mass in category “S” sport horses is attributed to their level of training.
Address Klinik fur Pferde der Tierarztlichen Hochschule Hannover
Corporate Author Thesis
Publisher Place of Publication Editor
Language German Summary Language Original Title Die M-mode-Echokardiographie bei S-Dressur-, S-Springpferden und bei untrainierten Pferden
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0514-7158 ISBN Medium
Area Expedition Conference
Notes PMID:8342361 Approved no
Call Number Equine Behaviour @ team @ Serial 3749
Permanent link to this record
 

 
Author (down) Stachurska, A.; Pieta, M.; Nesteruk, E.
Title Which obstacles are most problematic for jumping horses? Type Journal Article
Year 2002 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 77 Issue 3 Pages 197-207
Keywords Horses; Jumping events; Obstacles; Behaviour
Abstract The objective of this study was to examine the behaviour of horses jumping over variously designed obstacles, i.e. which obstacles are easy for them and jumped willingly or which cause difficulties. This was judged by scoring two main faults at jumping events: the number of knock-downs and run-outs with refusals. The data concerned 609 rounds made at regional competitions of various classes for 100-140 cm obstacle height. They included 5639 jumps at 343 obstacles, in total. Seventy-two horses participated in the competitions. The number of faults at a particular obstacle depended on the obstacle-type, height, colour and arrangement. Uprights and oxers were the most frequently knocked-down, while the walls were the most often run-out. When the height was increased, more obstacles were knocked-down but the number of run-outs did not change significantly. The obstacles of two contrasting colours were jumped without fault more often, whereas, those of one colour, light or dark, caused most of the faults. The least number of faults was committed at the second obstacle in a combination compared with the first, third and single ones. The third and fourth obstacles in the courses were faulty jumps most often. The results suggest that most of the factors examined, which differentiate the obstacle and course design, may influence the horse's behaviour. In consequence, the horses make more or fewer faults jumping over various obstacles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-1591 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number refbase @ user @ Serial 3971
Permanent link to this record
 

 
Author (down) Spadavecchia, C.; Arendt-Nielsen, L.; Spadavecchia, L.; Mosing, M.; Auer, U.; van den Hoven, R.
Title Effects of butorphanol on the withdrawal reflex using threshold, suprathreshold and repeated subthreshold electrical stimuli in conscious horses Type Journal Article
Year 2007 Publication Veterinary anaesthesia and analgesia Abbreviated Journal Vet Anaesth Analg
Volume 34 Issue 1 Pages 48-58
Keywords Analgesics, Opioid/pharmacology; Animals; Butorphanol/*pharmacology; Consciousness; Electric Stimulation; Electromyography; Female; Forelimb/physiology; Horses/*physiology; Male; Pain/veterinary; Pain Threshold/*drug effects; Reflex/*drug effects
Abstract OBJECTIVE: To assess the effects of a single intravenous dose of butorphanol (0.1 mg kg(-1)) on the nociceptive withdrawal reflex (NWR) using threshold, suprathreshold and repeated subthreshold electrical stimuli in conscious horses. STUDY DESIGN: 'Unblinded', prospective experimental study. ANIMALS: Ten adult horses, five geldings and five mares, mean body mass 517 kg (range 487-569 kg). METHODS: The NWR was elicited using single transcutaneous electrical stimulation of the palmar digital nerve. Repeated stimulations were applied to evoke temporal summation. Surface electromyography was performed to record and quantify the responses of the common digital extensor muscle to stimulation and behavioural reactions were scored. Before butorphanol administration and at fixed time points up to 2 hours after injection, baseline threshold intensities for NWR and temporal summation were defined and single suprathreshold stimulations applied. Friedman repeated-measures analysis of variance on ranks and Wilcoxon signed-rank test were used with the Student-Newman-Keul's method applied post-hoc. The level of significance (alpha) was set at 0.05. RESULTS: Butorphanol did not modify either the thresholds for NWR and temporal summation or the reaction scores, but the difference between suprathreshold and threshold reflex amplitudes was reduced when single stimulation was applied. Upon repeated stimulation after butorphanol administration, a significant decrease in the relative amplitude was calculated for both the 30-80 and the 80-200 millisecond intervals after each stimulus, and for the whole post-stimulation interval in the right thoracic limb. In the left thoracic limb a decrease in the relative amplitude was found only in the 30-80 millisecond epoch. CONCLUSION: Butorphanol at 0.1 mg kg(-1) has no direct action on spinal Adelta nociceptive activity but may have some supraspinal effects that reduce the gain of the nociceptive system. CLINICAL RELEVANCE: Butorphanol has minimal effect on sharp immediate Adelta-mediated pain but may alter spinal processing and decrease the delayed sensations of pain.
Address Anesthesiology Section, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, Berne, Switzerland. claudia.spadavecchia@veths.no
Corporate Author 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 1467-2987 ISBN Medium
Area Expedition Conference
Notes PMID:17238962 Approved no
Call Number refbase @ user @ Serial 92
Permanent link to this record
 

 
Author (down) Spadavecchia, C.; Arendt-Nielsen, L.; Andersen, O.K.; Spadavecchia, L.; Doherr, M.; Schatzmann, U.
Title Comparison of nociceptive withdrawal reflexes and recruitment curves between the forelimbs and hind limbs in conscious horses Type Journal Article
Year 2003 Publication American journal of veterinary research Abbreviated Journal Am J Vet Res
Volume 64 Issue 6 Pages 700-707
Keywords Animals; Consciousness; Female; Forelimb/*physiology; Hindlimb/*physiology; Horses/*physiology; Male; Nociceptors/physiology; Pain/*physiopathology/*veterinary; Pain Threshold/physiology; Recruitment, Neurophysiological/physiology; Reflex/*physiology
Abstract OBJECTIVE: To compare nociceptive withdrawal reflexes (NWRs) evoked from the distal aspect of the left forelimb and hind limb in conscious standing horses and to investigate NWR recruitment for graded electrical stimulation intensities. ANIMALS: 20 adult horses. PROCEDURE: Surface electromyographic (EMG) activity evoked by transcutaneous electrical stimulation of the digital palmar (or plantar) nerve was recorded from the common digital extensor and cranial tibial muscles. Stimuli consisted of 25-millisecond train-of-5 constant current pulses. Current intensity was gradually increased until NWR threshold intensity was reached. The EMG signal was analyzed for quantification of the NWR. Behavioral responses accompanying the reflex were scored (scale, 0 to 5). The NWR recruitment curves were determined at 0.9, 1.1, 1.2, and 1.3 times the NWR threshold intensity. RESULTS: The NWR threshold was significantly higher for the hind limb (median value, 6.6 mA; range, 3 to 10 mA) than the forelimb (median, 3 mA; range, 1.7 to 5.5 mA). The NWR of the hind limb had a significantly longer latency (median, 122.8 milliseconds; range, 106 to 172 milliseconds), compared with the forelimb (median, 98 milliseconds; range, 86 to 137 milliseconds), and it was associated with significantly stronger behavioral reactions. Gradual increase of NWR amplitude was evident at increasing stimulation intensities and supported by the behavioral observations. CONCLUSIONS AND CLINICAL RELEVANCE: We documented NWRs evoked from the forelimb and hind limb and their recruitment with stimuli of increasing intensity in horses. These results provide a basis for use of NWRs in studies on nociceptive modulation in horses.
Address Department of Clinical Veterinary Sciences, University of Berne, Switzerland
Corporate Author 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 0002-9645 ISBN Medium
Area Expedition Conference
Notes PMID:12828255 Approved no
Call Number refbase @ user @ Serial 93
Permanent link to this record
 

 
Author (down) Sondergaard, E.; Ladewig, J.
Title Group housing exerts a positive effect on the behaviour of young horses during training Type Journal Article
Year 2004 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 87 Issue 1-2 Pages 105-118
Keywords Horses; Housing; Human-animal relationship; Social environment; Training; Learning
Abstract In an experiment on the effects of social environment and training on the human-animal relationship, 20 horses were handled according to a defined schedule. Eight horses were housed singly and 12 horses were housed in four groups of 3 horses. Horses were handled three times per week in 10 min sessions from an age of 6 months until 2 years of age during two winter periods. A total of 50 and 70 sessions were given in the first and second period, respectively. Five randomly allocated people performed the training. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horse had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had “passed” a stage or after 10 min of training. In the second winter period, horses would start off at stage 1 again, and when they “passed” a stage they went on to the next stage within the same training session. Because of the change in training procedure results were analysed separately for the two winter periods. There was a significant difference between trainers in the number of times they allowed a horse to “pass” a stage within each winter period (χ32, P<0.05; χ32, P<0.001 for the first and the second winter period, respectively). Group housed horses “passed” more stages than single housed horses (17 versus 14; 27 versus 18 in the first and second winter period, respectively; P<0.05 for the interaction). Singly housed horses bit the trainer more frequently than did group housed horses (P<0.01). The responses of group housed horses to training clearly demonstrate the benefits of raising young horses in groups.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number refbase @ user @ Serial 724
Permanent link to this record