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Topic:Comparative Study
Comparative studies in equine research involve the systematic analysis of different horse breeds, management practices, or physiological responses to identify variations and similarities. These studies are instrumental in understanding how different factors influence health, performance, and behavior in horses. Common areas of comparison include genetic traits, nutritional requirements, disease resistance, and response to training. By evaluating these differences, researchers can develop targeted strategies for breeding, healthcare, and training. This page aggregates peer-reviewed research studies and scholarly articles that focus on the methodologies, findings, and implications of comparative studies in the context of equine science.
Identification of a granulocytic Ehrlichia strain isolated from a horse in Switzerland and comparison with other rickettsiae of the Ehrlichia phagocytophila genogroup. This case report describes a 12-year-old Arabian mare with granulocytic ehrlichiosis. Clinical signs included fever, apathy, anorexia, icterus, limb edema, and reluctance to move. Examination of buffy coat smears revealed Ehrlichia organisms in neutrophils and eosinophils. A band of 1,428 bp was amplified from DNA of leukocytes via nested PCR and was identified as part of the Ehrlichia 16S rRNA gene. It differed from the gene sequences of Ehrlichia phagocytophila and E. equi at two and three positions, respectively. Interestingly, the nucleotide sequence of the 16S rRNA was 100% identical to t...
Determination of the volume changes for pressure-induced transitions of apomyoglobin between the native, molten globule, and unfolded states. The volume change for the transition from the native state of horse heart apomyoglobin to a pressure-induced intermediate with fluorescence properties similar to those of the well-established molten globule or I form was measured to be -70 ml/mol. Complete unfolding of the protein by pressure at pH 4.2 revealed an upper limit for the unfolding of the intermediate of -61 ml/mol. At 0.3 M guanidine hydrochloride, the entire transition from native to molten globule to unfolded state was observed in the available pressure range below 2.5 kbar. The volume change for the N-->I transition is relat...
Articular Cartilage Optical Properties in the Spectral Range 300-850 nm. Measurements of absolute total reflectance were recorded from weight-bearing (n=9) and nonweight-bearing (n=9) equine articular cartilage specimens from 300 to 850 nm using a spectrophotometer with integrating sphere attachment. Following correction of measured spectra for interfacial reflections and edge losses, Kubelka-Munk theory was applied to estimate absorption and scattering coefficient, one-dimensional light intensity distribution, and light penetration depth. Kubelka-Munk absorption coefficients ranged from ∼7 cm-1 at 330 nm to ∼1 cm-1 at 850 nm. A localized absorption peak wa...
Direct sequencing of the HA gene of clinical equine H3N8 influenza virus and comparison with laboratory derived viruses. Equine influenza viruses propagated in the laboratory in alternate hosts such as embryonated hens' eggs or mammalian cell culture have been analysed by HA sequencing and antigenically and their sequence compared to the original virus present in clinical material. In contrast to clinically derived human influenza virus which generally grows in MDCK cells without change, the data for equine influenza virus were less clear in that variants of equine virus were derived in both eggs and cells. The study indicated that the current use of eggs for equine influenza virus surveillance and vaccine produ...
Molecular analysis of the virulence determinants of Clostridium perfringens associated with foal diarrhoea. During an epidemiological study of foal diarrhoea, over half of the cases yielded Clostridium perfringens which was significantly associated with disease (Netherwood et al., 1996b). However, the association could not be accounted for by enterotoxigenic isolates which had a low prevalence (Netherwood et al., 1997). Nonetheless, we have hypothesized that the association may be caused by a pathogenic sub-population which would be significantly more common amongst C. perfringens-positive cases compared with C. perfringens-positive healthy controls if it acted as a pathogen when present. Conversely...
Report of the Second Equine Leucocyte Antigen Workshop, Squaw valley, California, July 1995. The final assignment of antibody clusters for leucocyte antigens and immunoglobulins, as described in detail in Sections 3 and 4, is summarized in Table 4. Together with other mAbs developed outside of ELAW II (Table 9) this pool of reagents represent a powerful array of tools for the study of equine immunity. The Second Equine Leucocyte Antigen Workshop made considerable advances in pursuing the objectives of establishing the specificities of mAbs and achieving consensus on the nomenclature for equine leucocyte and immunoglobulin molecules. Of equal importance, several productive collaboratio...
Comparison of detomidine/ketamine and guaiphenesin/thiopentone for induction of anaesthesia in horses maintained with halothane. This prospective clinical study compared the physiological effects of two commonly used anaesthetic induction techniques in horses maintained with halothane. One hundred horses admitted for elective surgery were randomly allocated to receive either guaiphenesin (to effect) and thiopentone (5 mg/kg), or detomidine (20 microg/kg) and ketamine (2 mg/kg) for the induction of anaesthesia after acepromazine premedication. Anaesthesia was maintained with halothane in oxygen. There were no significant differences in breed, age, sex, weight, type of surgery and duration of anaesthesia between the group...
High thigh muscle strength but not bone mass in young horseback-riding females. To evaluate whether the type of weight-bearing loading subjected to the skeleton during horseback-riding was associated with differences in bone mass and muscle strength of the thigh, we investigated bone mass and isokinetic muscle strength in 20 female horse riders (age 17.9 +/- 0.6 years) who were riding 7.0 +/- 3.4 hours/week, and 20 nonactive females (age 17.8 +/- 1.1 years). The groups were matched according to age, weight, and height. Areal bone mineral density was measured in total body, head, lumbar spine, right femoral neck, Ward's triangle, and trochanter, the whole dominant and nond...
Equine monocyte-derived macrophage cultures and their applications for infectivity and neutralization studies of equine infectious anemia virus. Equine infectious anemia virus (EIAV) has been shown to infect cells of monocyte/macrophage lineage. These primary cells are intrinsically difficult to obtain, to purify and to culture in vitro for extended periods of time. As a result, most in vitro studies concerning this lentivirus make use of primary equine fibroblasts or transformed canine or feline cell lines. We describe methods that yield reproducibly pure cultures of equine blood monocytes from peripheral blood mononuclear cells. The in vitro differentiation of these cells into mature equine macrophage was verified using various cytoc...
[Equine Cushing syndrome (ECS). Case report, review of its diagnosis and therapy and substantial differences from Cushing syndrome in dogs]. Equine and canine Cushing's syndrome, both of which are the result of elevated cortisol levels, show some different pathogenetical and clinical features and require different therapeutical approaches. In older horses the equine Cushing's syndrome (ECS) is not uncommon. Nearly all cases result from excessive hormone production in cells of the pars intermedia of the pituitary. Besides elevated levels of adrenocorticotrope hormone (ACTH), high peripheral levels of pro-opiomelanocortin, beta-endorphines and alpha-melanocyte-stimulating hormone can be measured. In middle-aged and geriatric dogs, Cu...
Evidence of new cadmium binding sites in recombinant horse L-chain ferritin by anomalous Fourier difference map calculation. We refined the structure of the tetragonal form of recombinant horse L-chain apoferritin to 2.0 A and we compared it with that of the cubic form previously refined to the same resolution. The major differences between the two structures concern the cadmium ions bound to the residues E130 at the threefold axes of the molecule. Taking advantage of the significant anomalous signal (f" = 3.6 e-) of cadmium at 1.375 A, the wavelength used here, we performed anomalous Fourier difference maps with the refined model phases. These maps reveal the positions of anomalous scatterers at different locations...
Close relationship between equine and human molluscum contagiosum virus demonstrated by in situ hybridisation. To determine whether the virus responsible for human molluscum contagiosum (MCV) is the causal agent of a similar disease in horses, in situ hybridisations using cloned fragments of human MCV DNA labelled with digoxigenin were carried out on formalin-fixed biopsy sections of lesions from two horses with molluscum contagiosum-like skin lesions. In both instances there was evidence of specific hybridisation of the labelled probe to target DNA in the sections under high stringency conditions, identified by the development of a deep blue-purple stain in the cytoplasm of cells in the stratum spinos...
A dinucleotide mutation in the endothelin-B receptor gene is associated with lethal white foal syndrome (LWFS); a horse variant of Hirschsprung disease. Lethal white foal syndrome (LWFS) is a congenital anomaly of horses characterized by a white coat colour and aganglionosis of the bowel, which is similar to Hirschsprung disease (HSCR). We decided to investigate possible mutations of the endothelin-B receptor gene ( EDNRB ) in LWFS as recent studies in mutant rodents and some patients have demonstrated EDNRB defects. First, we identified a full-length cDNA for horse EDNRB . This cDNA fragment contained a 1329 bp open reading frame which encoded 443 amino acid residues. The predicted amino acid sequence was 89, 91 and 85% identical to human, bo...
Cloning of equine interleukin 1 receptor antagonist and determination of its full-length cDNA sequence. To clone equine interleukin 1 receptor antagonist (IL-1ra) and determine its full-length cDNA sequence. Methods: A cDNA library derived from lipopolysaccharide-stimulated equine monocytes was screened by means of plaque hybridization to radiolabeled equine IL-1ra DNA probes generated by means of the polymerase chain reaction. The cDNA nucleotide sequence for equine IL-1ra was determined by use of the dideoxy chain termination technique, analyzed by use of computer software for sequence characteristics, and compared with sequences reported for IL-1ra of other species. Results: The cDNA of equin...
Skeletal muscle glycolytic capacity and phosphofructokinase regulation in horses with polysaccharide storage myopathy. To determine whether polysaccharide storage myopathy (PSSM) in Quarter Horses is attributable to a defect in glycolysis or in the allosteric regulation of phosphofructokinase (PFK) enzyme. Methods: Muscle biopsy specimens were obtained from 6 Quarter Horses with PSSM and 8 Quarter Horse or Thoroughbred control horses. Methods: Maximal activity of glycogenolytic and glycolytic enzymes was determined spectrophotometrically. Maximal activity of PFK was determined for each horse at pH 8.0, and at pH 7.0 when variable concentrations of the activators, fructose 6 phosphate, fructose 2,6 bisphosphate...
Electromyographic activity of the long digital extensor muscle in the exercising Thoroughbred horse. Surface electrodes were used to record electromyographic (EMG) activity of the long digital extensor muscle on the right hindlimb of 8 Thoroughbred horses for 8 s at the walk and 8 s at the trot before (unfatigued) and after (fatigued) an exercise test. The exercise test was performed on a motorised treadmill set on a 10% grade. Each test started at a speed of 6 m/s which was increased by 1 m/s each minute until the horse fatigued as indicated by its inability to keep pace with the treadmill with minimal encouragement. Observations were made on the horses prior to conditioning (untrained state...
Quantitative assessment of motor neuron loss in equine motor neuron disease (EMND). The mean number of motor neurons was assessed in the C7 spinal cord segment of 5 EMND and 5 control horses. Mean number per section in EMND horses was reduced significantly (P<0.001). The mean neuronal loss was estimated at 31%. Each of the 5 affected horses had a mean neuronal count below the 95% confidence interval for control horses. The statistically significant difference between the 2 groups was consistent in the cranial, middle and caudal thirds of the C7 segment (P<0.001). The results of regression analysis indicated an association between neuronal reduction in EMND horses and th...
Force, speed, and oxygen consumption in thoroughbred and draft horses. Thoroughbred (TB) and draft horses (DH) have long been selected for tasks of very different intensities and force-speed relationships. To study their adaptations, we measured O2 consumption and related variables in three TB and four DH during progressive exercise tests on a level treadmill. The horses exerted a draft force of 0, 5, 10, 15, or 20% of their body weight at speeds that increased by 2 m/s every 3 min until they could not maintain that speed. We found that TB could exert the same draft forces as DH and, at each force, TB achieved about twice the speed, twice the external power, and ...
Tapeworm infection is a significant risk factor for spasmodic colic and ileal impaction colic in the horse. The association between the equine intestinal tapeworm Anoplocephala perfoliata and specific types of intestinal disease was investigated by matched case-control study using coprological and serological diagnosis. We have previously shown that the host IgG(T) response to 12/13 kDa antigens of A. perfoliata correlates well with infection intensity, therefore this antibody response was used to investigate the risk of colic at different levels of parasite infection intensity. One hundred and three spasmodic colic cases with an equal number of controls matched for age, breed and gender, and 20 ile...
Production and characterization of Ehrlichia risticii, the agent of Potomac horse fever, from snails (Pleuroceridae: Juga spp.) in aquarium culture and genetic comparison to equine strains. We report on the production and characterization of Ehrlichia risticii, the agent of Potomac horse fever (PHF), from snails (Pleuroceridae: Juga spp.) maintained in aquarium culture and compare it genetically to equine strains. Snails were collected from stream waters on a pasture in Siskiyou County, Calif., where PHF is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. Upon exposure to temperatures above 22 degrees C the snails released trematode cercariae tentatively identified as virgulate cercariae. Fragments of three different genes (genes for 16S rRN...
[Lysozyme activity in the milk of sucking mares during lactation]. It was the aim of this project to investigate the changes of the lysozyme activity in the milk of mares during the lactation period. Further on the influence of race, date of conception and foaling, age and number of lactations on the lysozyme activities in milk was analysed. Milk samples were collected from 44 mares (trotters, warmblood, quarter horses) from eight farms between the 1st and 90th day p. p. The activity of the lysozyme was measured by a turbidometric method. Summarizing the following results are obtained: Lysozyme activities in mare milk of the 1st and 3rd day p. p. were higher ...
Comparisons of three probability formulae for parentage exclusion. Three general formulae calibrate the average capability of marker systems to dispute falsely reported pedigree records in uniparous species. The most familiar exclusion formula applies to paternity, although the same formula applies equally to maternity. Another formula faults the relationship of a single offspring with its putative parent; for example, where the genotype of the other parent is not available. The remaining formulae excludes both of the falsely recorded parents of a substituted offspring. Simplified forms of the three general formulae facilitate the calculation of maximal avera...
Objectivity of two methods of differentiating fibre types and repeatability of measurements by application of the TEMA image analysis system. The objectivity of two of the most widely used methods for differentiation of fibre types, i.e. 1) the myosin ATP-ase method (Brooke and Kaiser, 1970a,b) and 2) the combined method, by which the myosin ATP-ase reaction is used to differentiate between fast and slow twitch fibres and NADH-tetrazolium reductase activity is used to identify the subgroups of fast twitch fibres (Ashmore and Doerr, 1970, Peter et al., 1972), was assessed in muscle samples from horses, calves and pigs. We also assessed the objectivity of the alpha-amylase-PAS preparation for the visualisation of capillaries (Andersen...
A conserved structural element in horse and mouse IGF2 genes binds a methylation sensitive factor. The equine IGF2 gene has been cloned and characterised. It spans a 9 kb region, which is substantially less than the corresponding human gene. Three coding exons and three untranslated leader exons, all highly homologous to those in other species, were identified. Downstream of the polyadenylation site in exon 6, a dinucleotide repeat sequence was identified. Three putative promoters (P1-P3) were localised in the 5' region of the gene. RNase protection analysis revealed two active promoters in fetal tissues, P2 and P3, whereas P3 was the only promoter active in adult tissues. This represents a...
Further characterization of equine brain gangliosides: the presence of GM3 having N-glycolyl neuraminic acid in the central nervous system. Equine brain gangliosides were isolated and their structures were characterized, to examine whether equine brain has N-glycolyl neuraminic acid in gangliosides, since other mammals predominantly possess N-acetyl neuraminic acid in brain gangliosides, and equine erythrocytes and organs except the brain have gangliosides exclusively containing N-glycolyl neuraminic acid. The gangliosides purified from the brain were identified by proton NMR spectroscopy and mass spectrometry, as well as GLC, resulting in their identification as GM4, GM3, GM2, GM1, GD1a, GD1b, and GT1b. Of these gangliosides, GM3...
The effects of equivalent doses of tromethamine or sodium bicarbonate in healthy horses. To describe the effects of tromethamine, a putative treatment for metabolic acidosis, and to compare its biochemical effects with those of sodium bicarbonate. Methods: Randomized intervention study with repeated measures. Methods: 16 healthy horses, 3 to 17 years old, weighing 391 to 684 kg. Methods: Ten horses received 3 mEq/kg tromethamine and six received 3 mEq/kg sodium bicarbonate. Samples of venous blood and cerebrospinal fluid (CSF) were collected at intervals before and after drug administration. Heart rate and breathing rate were also recorded at intervals. Results: Median standard ba...
