Non-affected Dogs Research Articles

Osmotic stress in red blood cells from Beagles with hemolytic anemia

Summary Red blood cell populations separated by density centrifugation were compared in a dynamic assay of osmotic stress. Red blood cells from Beagles genotypically normal and nonanemic (nonaffected), Beagles with inherited hemolytic anemia (anemic), and Beagles presumed to be carriers of the anemia trait (trait carriers) were examined for rate and extent of swelling after exposure to the ionophore A23187 in a medium containing calcium and potassium chloride. Comparisons were made between rbc populations separated on the basis of density. Significant differences were observed in the rates of cell swelling in rbc populations separated by density between nonaffected and anemic Beagles. The response of rbc from Beagles presumed to carry the anemia trait was similar to that of rbc from nonaffected dogs. One phenotypic expression of this inherited abnormality of rbc in Beagles was an accelerated rate of rbc swelling under osmotic stress, and this swelling response diminished with increasing rbc density.

Biomechanical properties of skin and wounds in Ehlers-Danlos syndrome.

The biomechanical properties of wounded and nonwounded skin were studied in three dogs and three cats affected with type I Ehlers-Danlos syndrome. Three nonaffected dogs and one nonaffected cat served as controls. Samples of wounded skin and adjacent normal skin were harvested at days 75, 138, 141, 144, 147, and 150. Samples were subjected to uniaxial tensile strength testing. Tensile strength, energy absorbed, and site of failure were recorded. In the dogs with Ehlers-Danlos syndrome, there was an increase in tensile strength in samples containing a scar over adjacent intact skin. In nonaffected dogs, affected cats and the nonaffected cat, the nonwounded skin samples had greater tensile strength. The energy absorbed by the skin samples during testing was highly correlated with tensile strength.

Cutaneous wound healing in Ehlers-Danlos syndrome.

Wound healing in five dogs and five cats affected with a connective tissue dysplasia resembling Ehlers-Danlos syndrome of humans was compared with wound healing in 10 nonaffected animals. Six skin incisions on the lateral aspects of the thorax and abdomen of each animal were sutured and assessed daily for 75 days for evidence of healing. All wounds in nonaffected dogs, affected cats, and nonaffected cats healed by first intention. Three incisions in affected dogs had dehiscence of all or part of the incision line and healed by granulation, contraction, and epithelialization. Biopsies taken at 3, 6, 9, 12, 15, and 75 days were compared histologically to determine if there were any differences in rates of healing between affected and nonaffected animals. Epidermal thickening and scab formation were noted at days 3 and 6 in both affected and nonaffected animals. Infiltration with mononuclear cells and fibroplasia steadily increased from day 6 to day 15 in all groups. Collagen fibril formation was evident by day 9. At day 75, incision sites were recognized by fine, more compact collagen bundles and lack of adnexal structures, as compared with the adjacent dermis in both affected and nonaffected animals. Although delayed wound healing has been reported to be a complication of Ehlers-Danlos syndrome in humans, using clinical and histologic criteria, wound healing in dogs and cats with Ehlers-Danlos syndrome appears to be similar to nonaffected animals.

Retinal degenerations in the dog: IV. Early retinal degeneration ( erd) in Norwegian elkhounds

A new early onset hereditary retinal degeneration is characterized in Norwegian elkhound dogs. This disease, termed early retinal degeneration (erd), was studied in 10 affected dogs, from 30 days- to 7 years old, clinically, by electroretinography, and by light- and electron-microscopic morphology. Control studies were performed on 49 non-affected dogs. Affected dogs are initially nightblind, and become totally blind between 12- and 18 months of age. The postnatal development of their rod and cone photoreceptors is abnormal both structurally and functionally. Morphologically, rod and cone inner- and outer-segment growth occurs but appears uncoordinated. Adjacent rods become very disparate in the size and proportions of their inner- and outer segments. Prominent villiform processes extend from the inner segments of rods and, to a lesser extent, cones. Synaptic terminals of rods and cones fail to develop properly. The b-wave of the electroretinogram fails to develop and the electroretinogram (ERG) remains a-wave-dominated. Subsequent to these abnormalities of development, the rods and cones degenerate, rapidly at first and later more gradually. In normal dogs, development of the ERG a- and b-waves is shown to follow, respectively, morphologic development of the photoreceptor outer segments and synaptic terminals. Similarly the abnormal development and subsequent degeneration of photoreceptor outer segments and synaptic terminals in affected dogs, correspond in time course to development and degeneration of the ERG a- and b-waves.

Isolation of collagen from the skins of Ehlers-Danlos syndrome-affected dogs by acetic acid extraction and pepsin digestion

Collagen was isolated by acetic acid extraction in the presence of protease inhibitors and also by pepsin digestion from the skins of dogs affected with the Ehlers-Danlos syndrome and the skins on non-affected dogs. The collagen preparations isolated by acetic acid extraction from the Ehlers-Danlos syndrome-affected dog skin contained a greater proportion of alpha-chains than the collagen preparations from the normal dog skin. When the collagen from the Ehlers-Danlos syndrome-affected dog skin was reduced with NaBH4 before heat denaturation, and electrophoresis, there was a greater proportion of beta-chains present. The collagen isolated from the normal dog skin was not affected by the NaBH4 reduction. Collagen preparations isolated by pepsin digestion from both the Ehlers-Danlos syndrome-affected dog skin and the non-affected dog skin contained the same quantity of alpha- and beta-chains. In addition, collagen from both affected and non-affected dog skins isolated by pepsin digestion contained 10-11% type III collagen as determined by the interrupted sodium dodecyl sulfate polyacrylamide gel electrophoresis method. Pepsin digestion of the collagens isolated by acetic acid extraction in the presence of protease inhibitors from the skins of affected and non-affected dogs eliminated the differences between the alpha:beta ratios of the affected and non-affected collagen preparations.

The relationship of serotonin to a motor disorder of scottish terrier dogs

Serotonin (5-HT) content in brain and whole blood, 5-hydroxy-indoleacetic acid (5-HIAA) concentration in urine and cisternal cerebrospinal fluid (CSF) were determined in normal dogs and Scottish terrier dogs affected with an inherited motor disorder. In addition, the increases in CSF 5-HIAA following probenecid administration were measured in affected and nonaffected dogs at rest, during diethyl ether anesthesia and following p-chloro-phenylalanine administration. There was not a significant difference between the two groups of dogs in any of the mentioned measurements. These data suggest that the primary biochemical defect does not directly involve 5-HT.