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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.
Criteria for development of animal models of diseases of the respiratory system: the comparative approach in respiratory disease model development. Advances in the understanding of human respiratory disease can come from careful clinical studies of the diseases as they occur in man, but such studies are naturally limited in terms of experimental manipulation. In the last 2 decades, an increasingly complex plethora of experimental respiratory disease models has been developed and utilized by investigators, but relatively less attention has been paid to the naturally occurring pulmonary diseases of animals as potential models. This paper is aimed at presenting selected examples of spontaneous pulmonary disease in animals that may serve as e...
[Effect of 2 methods of demineralization on the on the preservation of glycoproteins and proteoglycans in the intertubular and peritubular dentin in the horse]. The effect of 2 methods of demineralization on the preservation of proteoglycans and glycoproteins was studied in the intertubular and peritubular dentine of the horse. The specimens embedded in Epon were demineralized with a 2% acid formic solution (Bonucci and Gheradi, 1975). Other fragments were treated with an organic solution of EDTA alkylammonium salt (Scott and Kyffin, 1979). These methods preserved in a satisfactory way these labile organic components. In the intertubular dentine, glycoproteins and proteoglycans were also identified, either associated with collagen fibres as a glue and...
Helix packing and subunit conformation in horse spleen apoferritin. An electron density map of horse spleen apoferritin at 0.28-nm (2.8 A) resolution and its preliminary interpretation have been described previously. Rigorous examination of this and newer maps at the same nominal resolution but calculated from more extensive data sets, including model building in a Richards' comparator, now allows us to report on structural features in more detail. We list inter-helical angles within and between neighbouring subunits, and describe a new short region of inter-subunit anti-parallel pleated sheet. A short section of electron density not properly accounted for in ...
[The immunological relation between human and equine Gc proteins (author’s transl)]. The immunological comparison of human and equine Gc proteins showed partial identical reactions between both species. Immunizations of goats and rabbits with horse serum produced antisera able to recognize human Gc proteins.
Comparison of milk and blood plasma progesterone concentrations in cycling and pregnant mares. Progesterone concentrations were measured in milk and blood plasma for 15 mares throughout a normal estrous cycle and early pregnancy to determine the feasibility of utilizing progesterone in milk as an indicator of pregnancy. Samples were obtained daily from foaling until diagnosis of pregnancy by rectal examination at 30 to 35 days of gestation. Progesterone in milk and blood plasma was quantified by radioimmunoassay. Mean progesterone concentrations (+/- SE) in plasma from foaling to foal heat and during estrus, luteal phase and pregnancy were .51 +/- .09 ng/ml, .53 +/- .08 ng/ml, 3.88 +/- ...
Pancreatic beta-cell function in the fetal foal and mare. Insulin secretion and the factors influencing beta-cell function were investigated in the chronically catheterized fetal foal and mare during the second half of gestation. The response of the fetal beta cells to exogenous glucose was also examined. The mean concentration of insulin in the fetal foal was 7.5 +/- 0.5 (S.E.M.) microunit./ml (n = 20) which was significantly less than the corresponding maternal value of 49.0 +/- 5.0 microunit./ml (n = 20, P < 0.01). The insulin concentration in non-pregnant horses was 24.5 +/- 1.5 microunit./ml (n = 5) which was significantly less than the value...
Attempted induction of an avian eosinophilia using various agents. A series of experiments is described in which attempts were made to produce an avian eosinophilia using various agents. Although none of the experiments was decisive, two demonstrated a slight rise in the eosinophil counts. In one experiment horse serum was injected into a group of fowls on alternate days for 42 days. No eosinophils were seen in any blood smears after this treatment. After a rest period of eight days the birds received further injections for 10 days. The mean eosinophil count rose to over 4 per cent with a range of 1 to 11 per cent. It is considered that this type of response ...
Effect of pyrrolizidine alkaloid-induced hepatic disease on plasma amino acid patterns in the horse. Plasma amino acid patterns were studied in 6 clinically normal adult horses during the course of hepatic disease induced by feeding them plants containing pyrrolizidine alkaloids. At death, there were significant (P less than 0.01) increases in glutamine, proline, tyrosine, asparagine, lysine, histidine, alanine, phenylalanine, methionine, aspartic acid, and ornithine values. There were no significant changes in glycine, valine, isoleucine tryptophan, and arginine values. There were significant (P less than 0.01) decreases in citrulline. Ammonia increased 4-fold. Alpha-Aminoadipic acid and alp...
Sequence of the low activity equine erythrocyte carbonic anhydrase and delineation of the amino acid substitutions in various polymorphic forms. the sequence of the low activity form of equine erythrocyte carbonic anhydrase has been determined. The most common electrophoretic form, designated D, has been found to have five substitutions. Amino acid exchanges in the electrophoretic variants known as A1, A2, B, and T have been found at six other positions. The data do not permit calculation of the number of polymorphic forms of this enzyme. The equine D isozyme and the analogous human enzyme are quite homologous, 211 of their 260 residues, or 81%, being identical.
Histochemical properties of muscle fibres types and enzyme activities in skeletal muscles of Standardbred trotters of different ages. Fibre characteristics and enzyme activities were determined for the gluteus, semitendinosus, vastus lateralis and triceps brachii muscles of 55 Standardbred trotters of different ages. Four fibre types (I, IIA, IIB, IIC) were demonstrated by histochemical staining of myofibrillar adenosine triphosphatase after preincubation at different pH values. Type II fibres predominated in all the muscles and the type IIA/IIB ratio was higher in horses over 5 years than in younger horses, except in the vastus in which the IIA/IIB ratio did not change with age. The vastus had the highest proportion of type...
Turnover of 131I-labelled albumin in horses with gastrointestinal disease. Four horses with a history of chronic diarrhoea and weight loss were studied. Three of them revealed malabsorption, as indicated by decreased absorption of D(+)-xylose. Three patients had distinct hypoalbuminaemia, and 131I-albumin turnover rates of these three horses were increased, compared to two normal control horses. However, the increases were not very marked, probably because actual signs of enteric disease were few in the patients, all of which were studied during convalescence. It is suggested that the observed hypoalbuminaemia is due to a gastrointestinal protein loss during the chro...
Smooth muscle cells in the testicular capsule of the horse, pig and sheep. Smooth muscle cells are present in the tunica albuginea testis of the horse, pig and sheep. typical fusiform muscle cells constitute a distinct layer up to 0.3 micrometer thick in the horse; there are fewer muscle cells, mainly of the branched form, in the pig; whereas in the sheep the muscle component is least well developed, with some cells intermediate in form between smooth muscle cells and fibroblasts (myofibroblasts). Attention is drawn to the continuity of this capsular muscle with the smooth muscle associated with the vasculature of the spermatic cord in the horse. This association sug...
Equine connective tissue tumors contain unintegrated bovine papilloma virus DNA. Bovine papilloma virus (BPV) appears to be the etiological agent of common equine connective tissue tumors. We investigated the physical state of the viral DNA within such tumors and found no indication for integration into the host genome. The BPV genomes were present as free circular episomes. Two equine sarcoids were shown to contain multiple copies of free circular BPV type 1 (BPV-1) DNA. When the tumors were digested with several single-cut restriction enzymes, there were only form III BPV-1 DNA sequences could be revealed. One of the sarcoids contained, apart from wild-type BPV-1 DNA, a ...
A survey of Clostridium perfringens enterotoxin antibody in human and animal sera in western Canada. Sera from human, cattle, sheep, swine, and horse populations in western Canada were tested for the presence of Clostridium perfringens enterotoxin antibody by the passive hemagglutination (PHA) test, supplemented by an immunodiffusion test and by counterimmunoelectrophoresis. A total of 224 human, 345 cattle, 165 sheep, 620 swine, and 768 horse serum samples were examined. Low-titer reactions in the PHA test were detected in human, cattle, horse, and swine sera, in that order, with no titers demonstrated in sheep. The titers in human sera ranged up to 1:128 and three of these samples were also...
Studies on the physiopathology of chronic obstructive pulmonary disease in the horse. II. Right heart haemodynamics. Pressure curves obtained by cardiac catheterization of the pulmonary artery, right ventricle and right atrium of 9 horses and ponies with chronic obstructive pulmonary disease (COPD) were compared with those similarly recorded from 6 clinically normal control subjects. The mean pulmonary peak systolic, pulmonary minimum diastolic and ventricular peak systolic pressures of the COPD subjects were significantly higher (P less than 0,01) than the corresponding mean pressures of the clinically normal control subjects. The mean pressure calculated from pressure curves obtained from 8 Thoroughbreds i...
On the natural history and comparative pathology of the blue naevus. In man the epidermis is the final destination for most of the melanocytes which are of neural crest origin, and they migrate to a variety of sites. Dermal melanocytic distribution, conspicuous in some lower animals, has a very restricted normal distribution in man, and of the variety of anomalies which exist the blue naevus is the most frequently encountered. It is comparable to the common melanocytoma of dog and hamster. More widespread dermal melanocytoses are rare, and a unique case in which death from melanoma supervened, recently recorded by the author, is an example of a syndrome the onl...
Intestinal atresia and stenosis in animals: a report of 34 cases. Intestinal atresia was found in 29 animals and stenosis in five. Atresia was found in the duodenum in one pup; in the jejunum in nine calves, two lambs and one piglet; in the ileum in one pup, one lamb and one piglet; and in the colon in one foal, seven calves, one lamb, one piglet and three kittens. Stenosis was found in the duodenum of a foal, in the jejunum in two calves and one pup, and in both the ileum and the colon of a kitten. One lamb showed ileal atresia as well as ileal stenosis. We classified the atresia as type 1, membrane atresia (four cases); type 2, cord atresia (six cases); an...
Response of plasma LH and FSH to gonadotropin-releasing hormone in pony foals and ovariectomized pony mares. Plasma FSH and LH response to a synthetic GnRH analog was measured in adult ovariectomized pony mares (OVX) and in pony foals (<70 days of age) during late spring (May-June). FSH and LH responded in a similar fashion (200% increase) in the OVX mare, which is different from other reports for intact mares. There was a greater mean response to a comparable dose of GnRH in the prepubertal foal for both FSH (500%) and LH (900%) than in the OVX mare. There was a positive correlation between age and the maximum FSH response to GnRH in male and female foals. The LH response was positively correlate...
Comparison of muscle fiber types from 2-year-old fillies of the Belgian, Standardbred, Thoroughbred, Quarter horse and Welsh breeds. The percentages of three muscle fiber types in the biceps femoris and triceps brachii were determined in five breeds of horses: Belgians, Standardbreds, Thoroughbreds, Quarter Horses and Welsh ponies. Biopsies were taken from the two muscles from each of four 2-year-old untrained fillies of each breed. Percentages of red, white and intermediate fiber types were determined from tissues stained for succinic dehydrogenase activity. Intermediate fibers were the most numerous for all breeds. The difference between red and white fibers varied significantly with breed. Thoroughbreds had the highest p...
Maturation of equine epididymal spermatozoa. Spermatozoa from four regions of the epididymis and from ejaculated semen were evaluated for their resistance to cold shock, progressive motility, and structural stability. Spermatozoa were incubated at 38 C and their percentage of eosinophilia was compared with that of spermatozoa cooled to 0 C in 2 minutes, 10 C in 12 minutes, or 4 C in 22 minutes. Spermatozoa motility was estimated visually under phase-contrast microscopy and was recorded by cinematography. Structural stability of spermatozoa incubated in 0.05 M sodium borate buffer, 0.035 M sodium dodecyl sulfate (SDS), 0.002 M dithiothrei...
Assembly of intra- and interspecies hybrid apoferritins. An intraspecies hybrid apoferritin was assembled by mixing subunits of horse heart ferritin, which consists mainly of H-type subunits, and horse spleen ferritin, in which L-type subunits predominate. Interspecies hybrid apoferritins were reconstituted from subunits of human liver-horse spleen ferritins and from rat liver-horse spleen ferritins. All the hybrid ferritins migrated as single zones with electrophoretic mobilities intermediate between those of the parent ferritins. Isoelectric focusing data and immunological patterns were consistent with the view that the reassembled apoferritins we...
Incidence and morphology of equine and murine chondrocytic cilia. The incidence and structure of equine and murine chondrocytic cilia were studied using serial sections and transmission electron microscopy. Overall, 96% of all equine chondrocytes and 100% of all murine chondrocytes had one cilium. The structure of these cilia included rootlets, basal feet, alar sheets, and an axoneme of nine peripheral doublets which progressively bent and terminated as they coursed towards the tip of the ciliary shaft. Together with the previous studies on neonatal and adult canine chondrocytic cilia, we conclude that the structure and incidence of chondrocytic cilia does n...
[The effect of the age of stallions and mares on their fertility]. The study was based on the documentation of the Napajedla Stud Farm of the English Thoroughbred horse for 1888-1972. Evaluating the effect of the age of stallions on their fertility (leaving aside the variability of the age of their mothers), such an effect was found to be significant only in four out of the 26 studs evaluated. In 65% of the selected stallions, the correlation coefficients were found to be negative, but without statistical significance. However, the objective of the study was to evaluate stallions and mares parallelly as to their age variability and fertility. The relationship...
