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Biomedical subjects

D J Prieur

Publications and source records attributed to D J Prieur.

At least 55 records · Page 3Linked to original sources
PubMed1987

Serum susceptibility of bovine pasteurellas.

In this study, the serum sensitivity of 23 P. haemolytica isolates and 18 P. multocida isolates was determined by incubating dilutions of bacteria with equal volumes of fresh or heat-inactivated bovine serum for one, two, or three hours. Clinical isolates of both Pasteurella species were resistant to serum, whereas isolates from asymptomatic cattle varied in serum susceptibility. The classical pathway of complement appeared to be the principal means of complement mediated killing as detected by incubation in the presence or absence of EGTA-MgCl2. Lyzozyme and iron saturation of serum did not greatly affect serum susceptibility with either of the Pasteurella species.

Animals↗
PubMed1987

Neutropenia in cats with the Chediak-Higashi syndrome.

Thirteen cats with Chediak-Higashi syndrome and 22 control cats from the same colony, were evaluated for neutropenia. The absolute neutrophil counts of the Chediak-Higashi syndrome cats were significantly less (P less than 0.05) than those of the control cats. It is concluded that Chediak-Higashi syndrome cats, like Chediak-Higashi syndrome humans, have a neutropenia associated with the other manifestations of the syndrome. Lysozyme activity which was undetectable in the serum of both Chediak-Higashi syndrome and control cats was not of use for determining if the neutropenia was the result of neutrophil destruction.

Agranulocytosis↗
PubMed1986

Distribution of lysozyme in guinea pigs: implications for the function of gastrointestinal lysozyme in herbivores.

High levels of gastrointestinal lysozyme were present in the stomach of guinea pigs, but not in other portions of the gastrointestinal tract. Because the cecum is the fermentation organ of guinea pigs, these observations call into question the validity of the current hypothesis that the gastrointestinal lysozyme of herbivores functions in the digestion of bacteria from the anterior fermentation organ.

Animals↗
PubMed1986

Tissue specific deficiency of lysozyme in ruminants.

The distribution of lysozyme in tissues and fluids of ruminants was examined and it was determined that, except for a few tissues, ruminants were deficient in lysozyme activity compared with other species. The prominent exception was the abomasum of cattle, which had high levels of lysozyme activity. Mixing and extraction studies indicated that the lysozyme deficiency of ruminants was due neither to the presence of inhibitors of lysozyme in ruminant tissue nor to the binding of lysozyme in a manner that interfered with its enzymatic activity or assay. Other investigations have indicated that isozymes of lysozyme are present in ruminants and this study suggests that ruminants have only low levels of the isozyme that is the major isozyme of lysozyme in non-ruminants.

Abomasum↗
PubMed1986

Muscle lesions in beige (Chediak-Higashi syndrome) and heterozygous C57BL/6J mice.

Muscles from male and female C57BL/6J Chediak-Higashi syndrome (CHS) and phenotypically normal mice with the bgJ allele were studied microscopically and histochemically for the presence of basophilic cytoplasmic structures seen by other investigators in muscles of CHS mice of the SB/Le strain. Triceps brachii, gastrocnemius, quadriceps femoris, and biceps femoris muscles were examined. Multiple basophilic cylindrical lesions were present in hematoxylin and eosin-stained muscle from all groups. Lesions were positive for esterase, Sudan black, and periodic acid-Schiff. Lesions were only seen in type II muscle fibers. Type I muscle cells comprised less than an estimated 5% of the total muscle fibers in the four muscles examined. Scores were assigned based on the presence or absence of lesions in each muscle. Male mice of both phenotypes had significantly more lesions (P less than 0.05) than female mice. When sexes were combined, lesions were significantly (P less than 0.05) more numerous in normal mice than CHS mice for all muscles except the gastrocnemius. Lesions were significantly (P less than 0.05) more numerous in the phenotypically normal male than the CHS male mice for the triceps and quadriceps muscles. There was no significant difference (P greater than 0.05) between lesions of phenotypically normal female and female CHS mice. Basophilic cytoplasmic structures did not prove to be a manifestation of the CHS trait.

Animals↗
PubMed1986

Age-related changes of the retinal pigment epithelium of cats with Chediak-Higashi syndrome.

The eyes of 7, 9, and 11-year-old Chediak-Higashi syndrome (CHS)-affected cats were examined by light, fluorescence, and electron microscopy. Numerous round to oval bodies of various sizes were associated with the retinal pigment epithelium (RPE). These bodies stained positively with periodic acid-Schiff. They also displayed a bright yellow autofluorescence and stained positively with a prolonged Ziehl-Neelsen acid-fast method for demonstration of lipofuscin, suggesting that they contained lipofuscin or a lipofuscin-like material. Ultrastructural examination disclosed the bodies to be secondary lysosomes and large to giant-sized residual bodies. Many of the residual bodies were extracellular and formed drusen-like mounds, covered by deposits of basal lamina, beneath the RPE. Also evident were scattered degenerated RPE cells and other RPE cells that had detached and migrated into the interphotoreceptor space. The presence of drusenoid bodies, and the loss of cells from the RPE monolayer in CHS eyes have not been reported previously. Many of the changes in the CHS cat eyes resemble those in non-CHS aging eyes of man and other species.

Aging↗
PubMed1986

Prospective study of familial canine dermatomyositis. Correlation of the severity of dermatomyositis and circulating immune complex levels.

Familial canine dermatomyositis in collie dogs is a newly recognized spontaneous disease that resembles dermatomyositis in children. A litter of 9 collie dogs was studied from birth to 7.5 months of age. The onset and severity of dermatitis and myositis correlated with elevated serum levels of circulating immune complexes (CICs) and IgG. The immunoglobulin component of the CICs consisted principally of IgG. All dogs developed elevated levels of CIC before or concurrent with the onset of dermatitis. Myositis developed later. The CIC tended to peak between 14-18 weeks of age in all dogs except the most severely affected dog, in which the CICs continued to increase to 238 micrograms/ml (controls 30 micrograms/ml) at 7 months of age. In the moderately affected dogs the CICs tended to stabilize at the levels reached at 14-18 weeks, and in the mildly affected dogs the CICs tended to decrease to normal levels after 14-18 weeks. Although the dogs had electromyographic and repetitive nerve stimulation abnormalities, the abnormalities did not correlate with severity of dermatomyositis or degree of elevation of CICs or IgG. Necropsy at 7.5 months of age revealed that all dogs had myositis and 8 of 9 had dermatitis. Except for 1 dog, the severity of dermatomyositis correlated positively with higher levels of CICs. A strong positive association between elevated levels of CICs and IgG, but not IgM or IgA, was generally present. Elevated levels of CICs appear to be involved in the mechanisms that control the development, severity, and progression of dermatomyositis in collie dogs.

Animals↗
PubMed1986

Postmortem findings in four litters of dogs with familial canine dermatomyositis.

Postmortem evaluations were performed on 20 juvenile to young adult collie and collie-Labrador retriever crossbred dogs with dermatomyositis and 10 neonatal collies. Cutaneous, muscular, and vascular lesions were present in the juvenile and adult dogs and were most severe in areas of the head and distal extremities. In more severely affected dogs, lesions were more generalized, including myositis of esophageal muscle and arteritis of skin, muscle, bladder, and spermatic cord. Although viruses were not isolated from muscle, crystalline viral-like structures were present in cytoplasm of endothelial cells within skeletal muscle. The dogs with dermatitis and myositis consistently had lymphoid hyperplasia, especially of peripheral lymph nodes. More severely affected dogs were smaller than less severely affected littermates, and the more severely affected males had reduced weight of testicles and prostate glands, compared with body weight. The reduced weight of genital organs correlated positively with reduced fertility. A few lymphoid aggregates were present in or around thyroid glands of 6 of the 20 dogs. There was no histologic evidence of glomerular disease in any of the dogs. The neonatal collies had no evidence of dermatomyositis.

Animals↗
PubMed1985

Lysozyme activity in female genital tissues of normal and genetically lysozyme-deficient rabbits.

The internal genitalia of female normal rabbits and mutant lysozyme-deficient rabbits, which lack genetically the leukocytic isozyme of lysozyme, were assayed for lysozyme activity. The ovaries, uteri, and vaginas of the lysozyme-deficient rabbits had less than 20% of the lysozyme activity of normals. The oviducts, and in particular the caudal portions of the oviducts, had lysozyme activities up to 71% of the levels in normals. These observations suggest that the lysozymes of oviduct and leukocytes of rabbits are under the control of different genes.

Animals↗
PubMed1985

Animal model. Light and electron microscopy of hepatocytes of cats with Chediak-Higashi syndrome.

Cats with a condition resembling human Chediak-Higashi syndrome (CHS) are the most recently described of five species of animals with similar syndromes. In this study, hepatocytes of cats with CHS were examined by light microscopy, histochemistry, and transmission electron microscopy. Enlarged cytoplasmic granules, morphologically consistent with lysosomes, were present in many of the CHS cat hepatocytes. The enlarged lysosomes were generally larger and more numerous in centrilobular hepatocytes and were generally larger in older cats. The lesions were similar to those reported in other species with CHS suggesting that CHS cats are a valid animal model of human CHS.

Animals↗
PubMed1985

Aberrant melanosome development in the retinal pigmented epithelium of cats with Chediak-Higashi syndrome.

The Chediak-Higashi syndrome is a genetic disorder characterized by greatly enlarged cytoplasmic granules, including lysosomes and melanosomes. Eyes of humans and animals with Chediak-Higashi syndrome are hypopigmented to various degrees. Intraocular melanin granules vary in size, with some being massively enlarged. Electron microscopic examination of retinal pigmented epithelium of kittens with Chediak-Higashi syndrome disclosed a number of abnormalities of premelanosomes and melanosomes. Few premelanosomes were present. Most of the melanin granules were giant sized, but their structures varied. Some of the giant granules were composed of several premelanosomes and melanosomes in different stages of maturation. Others contained randomly oriented melanofilaments between melanosomes. There were also complex giant granules consisting of both melanosomal and lysosomal components. Inappropriate fusion of cytoplasmic granules appears to be the most likely mechanism for formation of the giant granules. Fusion of premelanosomes with lysosomes and resultant destruction of the premelanosomes probably is a major cause of the ocular hypopigmentation of Chediak-Higashi syndrome.

Aging↗
PubMed1985

Serum susceptibility of Haemophilus somnus from bovine clinical cases and carriers.

The serum susceptibility of 64 isolates of Haemophilus somnus from cattle was determined in a bactericidal assay with undiluted fresh or inactivated bovine serum with serial dilutions of bacterial suspension in RPMI 1640 medium. A total of 27 strains isolated from cattle with clinical disease (4 with thromboembolic meningoencephalitis, 13 with pneumonia, and 10 with reproductive failure) were compared with 35 strains from asymptomatic carriers (11 from the vagina and 24 from the prepuce). Essentially, all clinical isolates were serum resistant, whereas approximately 25% of preputial isolates were serum susceptible, as judged after 1 h of incubation in serum; a majority of vaginal isolates showed delayed serum susceptibility. Lysozyme played no role in serum killing, and the alternative complement pathway played only a minor role. Iron saturation, however, appeared to impart greater serum resistance to serum-susceptible strains from the vagina and prepuce. Perhaps the serum-susceptible strains from carriers would be useful vaccine candidates, but resistant strains from carriers may be pathogenic.

Animals↗
PubMed1985

Tapetal degeneration in cats with Chediak-Higashi syndrome.

The Chediak-Higashi syndrome (CHS) is a genetic disorder of man, cats, and four other animal species. Enlarged cytoplasmic granules, including lysosomes and melanosomes, characterize the syndrome. Cats affected with CHS lack funduscopically visible tapeta. In normal cats, the tapetum is the light reflecting cellular layer located in the choroid. The tapetal cells contain bundles of parallel cytoplasmic rods. In this study, eyes from CHS and control cats were examined by light microscopy and transmission electron microscopy. The CHS kittens up to 14 days of age had tapeta which appeared similar to those of the controls. By 28 days of age some of the CHS tapetal rods had degenerated. Degeneration of the tapetal rods progressed rapidly and by 56 days of age there was a dramatic difference in the ultrastructural appearance of the tapetal cells. All the rods had degenerated and the contents of the tapetal cells were disorganized. The tapetal layer gradually thinned over a period of several months until the layer was absent or nearly so in CHS cats over one year of age. This study demonstrated that there is a previously overlooked degenerative component of the Chediak-Higashi syndrome.

Aging↗
PubMed1985

Familial canine dermatomyositis: clinicopathologic, immunologic, and serologic studies.

Laboratory studies were performed on 3 Collies with familial canine dermatomyositis, 6 progeny from a breeding of 2 of the Collies (incross litter), and 4 progeny from the breeding of an affected Collie male and a normal Labrador Retriever (outcross litter). Hematologic abnormalities were leukogram changes consistent with inflammation, and, in 2 severely affected incross dogs, anemia of inflammatory disease. Serum muscle enzyme activities were not markedly increased. High concentrations of immune complexes and proportionally increased total immunoglobulin G were present in the sera of moderately and severely affected incross dogs. The same dogs had weakly positive direct Coombs' tests, and 1 affected outcross dog had a strongly positive direct Coombs' test. Rheumatoid factor was present in a severely affected incross dog. A few dogs had polyclonal globulin increases that were attributed to inflammation. Low antibody titers to canine calicivirus were present in 3 dogs and a low titer to canine coronavirus was present in 1 dog.

Animals↗
PubMed1985

Familial canine dermatomyositis: clinical, electrodiagnostic, and genetic studies.

Three Collies with a skin disorder, 6 progeny from a breeding of 2 of the Collies (incross litter), and the 4 progeny from the breeding of an affected Collie male and a normal Labrador Retriever female (outcross litter) were examined. By 7 to 11 weeks of age, all 6 dogs in the incross litter developed a qualitatively similar, but variably severe, dermatitis of the ears, face, lips, tip of the tail, and over bony prominences of limbs. Later, myopathic signs characterized by bilaterally symmetrical skeletal muscle atrophy of the head, neck, trunk, and extremities; facial palsy; decreased jaw tone; stiff gait; and hyperreflexia were observed in the dogs more severely affected by the dermatitis. Of the 4 dogs in the outcross litter, 3 had similar, but milder, clinical manifestations of the dermatitis and myopathy. Cutaneous lesions consisted of intraepidermal and subepidermal vesicles or pustules with intradermal infiltration by leukocytes. Muscle lesions included myositis; myofiber degeneration, regeneration, and atrophy; and fibrosis. A generalized myopathy in the severely affected dogs was indicated by abnormal readings on needle electromyograms and normal motor nerve conduction velocities. Spontaneous needle electromyogram abnormalities were fibrillation potentials, positive sharp waves, and bizarre high-frequency discharges. Retrospective and prospective genetic analyses disclosed a definite familial tendency and indicated the condition has an autosomal dominant component.

Animals↗
PubMed1984

Secretion of colonic isozyme of lysozyme in association with cecotrophy of rabbits.

The relation between the rabbit gastrointestinal (colonic) isozyme of lysozyme and the unique circadial coprophagic behavior of rabbits, termed "cecotrophy," was investigated. We found that lysozyme activity was very low in all segments of the rabbit gastrointestinal tract proximal to the fusus coli. However, the distal or nonsacculated colon, located distal to the fusus coli, had very high lysozyme activity throughout. It was determined, furthermore, that the lysozyme in the wall of the nonsacculated colon was secreted circadially into the colonic lumen in association with the circadial production of soft feces that were destined for reingestion by cecotrophy. The colonic lysozyme, therefore, was transferred to the stomach. These observations suggest that rabbit colonic lysozyme may have a possible function in the upper gastrointestinal tract and be analogous to ruminant abomasal-duodenal lysozyme.

Animals↗