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.

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.

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.

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.

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.

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.

Pathogenesis of feline gastric chlamydial infection.

Studies were conducted to determine whether the gastric chlamydiae that have been observed recently in cats are of pathologic significance. Chlamydiae were isolated in mouse L cell cultures from the homogenized pooled gastric mucosa of 3 cats that had been identified, by histopathologic examination, to have gastric chlamydiosis. Ten specific-pathogen-free kittens were exposed by aerosol and oral inoculation to the harvested feline gastric chlamydiae cell-culture media.

Ocular melanin pigmentation anomalies in cats, cattle, mink, and mice with Chediak-Higashi syndrome: histologic observations.

The Chediak-Higashi syndrome (CHS) is a hereditary disorder of man, with the homologous condition reported in five animal species. Multiple defects, including oculocutaneous hypopigmentation, are present in individuals with this syndrome. Giant cytoplasmic granules, including melanosomes and lysosomes, are characteristic.

Genetics of the fawn-hooded rat strain. The coat color dilution and platelet storage pool deficiency are pleiotropic effects of the autosomal recessive red-eyed dilution gene.

The inheritance of coat color, hooded-coat pattern, and platelet storage pool deficiency of fawn-hooded rats was studied by crossing fawn-hooded rats with rats of other strains. It was determined that the tan coat color and the platelet storage pool deficiency were pleiotropic effects of the autosomal recessive red-eyed dilution (r) gene. The hooded-coat pattern was determined to be the effect of a different autosomal recessive gene.

Familial canine dermatomyositis. Initial characterization of the cutaneous and muscular lesions.

Familial canine dermatomyositis is a recently identified disease of collie dogs that resembles human juvenile dermatomyositis. The lesions in the skin and muscles obtained by biopsy from two litters of dogs were characterized for the purpose of determining the similarity of the lesions to those of human dermatomyositis. The cutaneous lesions began between 7 and 11 weeks of age and were present on the face, lips, ears, and skin over bony prominences of the limbs, feet, sternum, and tip of the tail.

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.

Auricular chondritis in fawn-hooded rats. A spontaneous disorder resembling that induced by immunization with type II collagen.

A spontaneous apparently unique auricular chondritis in the pinna of fawn-hooded rats is described. The chondritis was bilateral, with adult onset, and resulted in a marked thickening of the auricular cartilage. Microscopically, islands of proliferative cartilage were present, and at the margins between the normal cartilage and the thickened abnormal cartilage a marked cellular inflammatory response was present.

Inheritance of congenital myasthenia gravis in smooth fox terrier dogs.

The phenotypes with respect to congenital myasthenia gravis of 132 smooth fox terrier dogs from 25 matings were analyzed. These included both prospective and retrospective matings. It was determined that congenital myasthenia gravis in the smooth fox terrier dog breed is inherited in an autosomal recessive manner with complete penetrance.

Secondary amyloidosis in a bull with Chediak-Higashi syndrome.

A ten year old Hereford bull with Chediak-Higashi syndrome was examined at necropsy after a lifelong history of recurrent bacterial infections. Amyloidosis, which has not been previously reported in Chediak-Higashi, was identified in liver, spleen and kidney.

Maltese dilution of domestic cats. A generalized cutaneous albinism lacking ocular involvement.

The Maltese dilution is an autosomal recessive trait of cats that dilutes black cats to blue, and orange cats to cream. The pigmented cutaneous and ocular tissues of Maltese dilution and control cats were examined and compared by light microscopy. Most of the melanin granules in all of the pigmented cutaneous tissues of the Maltese dilution cats were aggregated together into large clumps.

[3H]-imipramine binding sites in fawn-hooded rats.

The existence of high-affinity [3H]-imipramine recognition sites was demonstrated in membranes prepared from the cerebral cortex, hypothalamus and platelets obtained from fawn-hooded rats. The Bmax and Kd values for [3H]-imipramine binding to cerebral cortical membranes were virtually identical to those obtained with cortical membrane preparations of Sprague-Dawley rats. An NBR strain of rats, genetically related to fawn-hooded rats, was found to have significantly higher levels of [3H]-imipramine binding sites in cerebral cortical membranes when compared to fawn-hooded and Sprague-Dawley rats.

Natural killer cell activity in fawn-hooded rats.

Fawn-hooded (FH) rats were shown to lack the genetically conditioned defect of natural killer (NK) activity hypothesized to be present by analogy with the Chediak-Higashi syndrome (CHS) in mice and human beings. In 4-h 51Cr release assays, splenic NK cells from FH rats killed YAC-1, RL male l and G1-TC tumor targets without deficiency based upon comparison with cells from BD-IV, BD-IX and NBR inbred rat strains. Progeny of BD X FH F1 rats backcrossed to FH failed to reveal a correlation of reduced NK activity and dilute coat color.

Chlamydial infection of the gastric mucosa in twelve cats.

Twelve cats, all from research or commercial breeding colonies, had unidentified, intracellular organisms in the gastric mucosa. Histochemical staining and ultrastructural features provided the basis for identification of the organism as a Chlamydia sp. Ultrastructural observations were restricted to one of the 12 infected cats.

Prevalence, lesions, and differential diagnosis of Ollulanus tricuspis infection in cats.

Ollulanus tricuspis were found in the stomachs of 26 of 201 cats which were mainly from Washington and Idaho. Twenty-four of the cats were from research or commercial breeding colonies (catteries) and two were pets. Twenty-seven percent of colony cats were infected with O.

Abnormal retinal projections in cats with the Chediak-Higashi syndrome.

The Chediak-Higashi syndrome (CHS) occurs in mammals, including humans and cats. The CHS is characterized by decreased oculocutaneous pigmentation, enlarged cytoplasmic granules, increased susceptibility to infections, and a hemorrhagic tendency. Ocular anomalies include pale irides and albinotic or subalbinotic fundi.

Ultrastructure of resting and activated storage pool deficient platelets from animals with the Chédiak-Higashi syndrome.

The ultrastructural of platelets from Chédiak-Higashi (CH) and normal cattle, mink, and cats at rest was studied. Platelets from CH animals had a virtual absence of platelet dense granules. Alpha granules, amorphous membrane-surrounded structures, mitochondria, and microtubules of CH bovine platelets were similar in number and appearance to those in normal bovine platelets.