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Biomedical subjects

D J Prieur

Publications and source records attributed to D J Prieur.

At least 19 recordsLinked to original sources

Comparison of the tyrosine aminotransferase cDNA and genomic DNA sequences of normal mink and mink affected with tyrosinemia type II.

Type II tyrosinemia, designated Richner-Hanhart syndrome in humans, is a hereditary metabolic disorder with autosomal recessive inheritance characterized by a deficiency of tyrosine aminotransferase activity. Mutations occur in the human tyrosine aminotransferase gene, resulting in high levels of tyrosine and disease. Type II tyrosinemia occurs in mink, and our hypothesis was that it would also be associated with mutation(s) in the tyrosine aminotransferase gene. Therefore, the transcribed cDNA and the genomic tyrosine aminotransferase gene were sequenced from normal and affected mink. The gene extended over 11.9 kb and had 12 exons coding for a predicted 454-amino-acid protein with 93% homology with human tyrosine aminotransferase. FISH analysis mapped the gene to chromosome 8 using the Mandahl and Fredga (1975) nomenclature and chromosome 5 using the Christensen et al. (1996) nomenclature. The hypothesis was rejected because sequence analysis disclosed no mutations in either cDNA or introns that were associated with affected mink. This suggests that an unlinked gene regulatory mutation may be the cause of tyrosinemia in mink.

Amino Acid Sequence↗

Distribution of tyrosine aminotransferase activity in mink (Mustela vison).

The distribution of the enzyme tyrosine aminotransferase in tissues of mink, Mustela vison, was investigated. High levels of enzymatic activity were detected only in liver, documenting the hepatic-specific nature of this enzyme in this species. Further studies disclosed that tyrosine aminotransferase is not absent from non-hepatic tissues because of the lack of the use of a stabilized buffer, sensitivity to temperature, or due to the presence of an inhibitor. Collectively, these results suggest that the enzymatic assay of tyrosine aminotransferase will be unlikely to be an efficacious approach for identifying mink that are heterozygous for the autosomal recessive deficiency of this enzyme that is common in dark mink.

Animals↗

Clinical and morphologic features of mucopolysaccharidosis type II in a dog: naturally occurring model of Hunter syndrome.

A 5-year-old male Labrador Retriever had progressive incoordination, visual impairment, and exercise intolerance. Coarse facial features, macrodactylia, unilateral corneal dystrophy, generalized osteopenia, progressive neurologic deterioration, and a positive urine spot test for acid mucopolysaccharides suggested mucopolysaccharidosis. Intracytoplasmic vacuoles were most prevalent in epithelial cells, endothelial cells, and histiocytes of liver, kidney, thyroid gland, and spleen. Ultrastructural examination disclosed electron-lucent floccular to lamellar membrane-bound storage material characteristic of mucopolysaccharides. Periodic acid-Schiff-positive intracytoplasmic material was identified in multiple neurons in the medulla, pontine nucleus, cerebellum, and spinal gray matter horns. Biochemical assays identified a deficiency in iduronate-2-sulfatase (IDS) activity in cultured dermal fibroblasts compared with normal dogs. Hair root analysis for IDS showed that the dam was a carrier of X-linked Hunter syndrome and that a phenotypically normal male littermate of the affected dog was normal. This is the first report of Hunter syndrome or mucopolysaccharidosis type II in a dog.

Animals↗

Auditory brainstem responses in cats with Chediak-Higashi syndrome.

Auditory brainstem responses ABRs were recorded in cats with Chediak-Higashi syndrome using monaural stimulation. The components appearing between 1 and 3 ms after stimulus onset were greatly attenuated in the ABRs recorded using a reference contralateral to the stimulated ear. These data suggest that abnormalities exist in the brainstem auditory pathway in the region of the superior olivary complex in cats with Chediak-Higashi syndrome.

Albinism↗

Prenatal diagnosis of Chediak-Higashi syndrome in the cat by evaluation of cultured chorionic cells.

The autosomal recessive disease Chediak-Higashi syndrome (CHS) is a progressive and generally fatal disease of humans. The underlying genetic defect in CHS is unknown and prenatal diagnostic methods have not been applied to this disease. The purpose of this study was to determine if CHS chorionic cells expressed a characteristic of CHS--enlarged lysosomes--that would permit the prenatal diagnosis of the disease. Cats with CHS, which have been shown to be homologous with human CHS, were used as the model system in this study. Chorionic tissue samples were obtained from CHS and control cat fetuses and cultures of cells were established. Acid phosphatase was utilized as a marker of lysosomes and cultures of chorionic fibroblasts from CHS and control fetuses were stained histochemically for acid phosphatase. The diameter of the largest lysosomes in 150 cells of each fetus was determined. The mean (+/- SD) diameter (in microns) of the largest lysosomes of normal fetuses was 0.9 +/- 0.13 (range 0.5-7.0 microns), whereas the mean diameter of lysosomes in CHS chorionic cells was 3.9 +/- 0.65 microns (range 0.5-25 microns). These means were significantly different (P less than 0.0001). These data suggest that it should be possible to diagnose human CHS in the first trimester by chorionic villus sampling.

Acid Phosphatase↗

Chromosomal fragile site expression in dogs: I. Breed specific differences.

Peripheral blood lymphocytes from clinically normal Doberman pinscher and boxer dogs were cultured for folate-sensitive and, in preliminary studies, aphidicolin-inducible fragile site expression. Both autosomal and X chromosomal fragile sites were observed in canine cells cultured under folate/thymidine depletion and in cells cultured in medium containing aphidicolin. Results from the three dogs evaluated for both folate-sensitive and aphidicolin-inducible fragile site expression showed that the frequency of fragile site expression was significantly (P less than 0.05) greater in cells cultured in medium containing aphidicolin than in cells cultured in folate/thymidine-depleted medium. Cells from the boxer dog expressed a high percentage (66.67%) of aphidicolin-inducible fragile sites in contrast to the Doberman pinscher dog in which only 21.10% of the lymphocytes expressed aphidicolin-inducible fragile sites. The frequencies of spontaneous and folate-sensitive fragile site expression did not vary significantly by breed of dog. Age of dog was significantly and positively correlated with frequency of folate-sensitive fragile site expression in dogs of the boxer breed, but not in dogs of the Doberman pinscher breed. The dog X chromosome expressed three folate-sensitive and aphidicolin-inducible fragile sites. The G-band location of these three fragile sites showed homology with three recognized constitutive common fragile sites on the human X chromosome: Xp22, Xq21, and Xq27.2. Two specific autosomal fragile sites were identified, one on the distal end of the long arm of chromosome 1 and one on the distal end of the long arm of chromosome 8. Other autosomal fragile sites were also apparent but could not be assigned reliably to specific chromosomes.

Aging↗

Chromosomal fragile site expression in dogs: II. Expression in boxer dogs with mast cell tumors.

Peripheral blood lymphocytes from boxer dogs with a history of cutaneous mast cell tumors were cultured for fragile site expression. As in a control group of dogs, cells from these dogs expressed folate-sensitive autosomal and X chromosome fragile sites. Cells from boxer dogs with mast cell tumors expressed the same three common fragile sites on the X chromosome as cells from control dogs. Three folate-sensitive autosomal fragile sites not observed in cells from the control dogs were identified in cells from boxers with mast cell tumors. These included fragile sites near the telomeres of the arms of chromosomes 3 and 4 and a fragile site on the distal half of chromosome 15. Cells from boxers with mast cell tumors showed a greater frequency of fragile site expression than did cells from control dogs, but this observation was attributed to an unintended selection bias for younger boxer dogs without mast cell tumors and older boxer dogs with mast cell tumors and an increased frequency of fragile site expression with increasing age in dogs of the boxer breed.

Aging↗

Prenatal lesions in an ovine fetus with GM1 gangliosidosis.

Sheep affected with ovine GM1 gangliosidosis are normal at birth and develop clinical signs, initially ataxia, commencing at approximately 5 months of age, which progresses rapidly to recumbency. Superovulation and embryo transfer techniques were applied to a flock of carrier sheep of ovine GM1 gangliosidosis to increase the numbers of carrier and affected animals. A recipient ewe with 3 at-risk fetuses died at 4 months of gestation (normal ovine gestation is 5 months), and spectrofluorimetric assay of cerebral lysosomal beta-galactosidase of the fetuses showed that 2 were carriers and one was an affected fetus. The affected fetus had marked cytoplasmic enlargement and vacuolization of central and peripheral nervous system neuronal soma and of hepatocytes and renal epithelial cells. Lectin histochemistry indicated abnormal storage of complex carbohydrates, with terminal saccharide moieties consisting of beta-galactose, N-acetylneuraminic acid, and N-acetylgalactosamine. This case underlines the need for prenatal initiation of therapy and also demonstrates that vacuolization alone is not the cause of clinical signs in this lysosomal storage disease in that clinical signs do not commence until at least 5 months after vacuolization is histologically apparent.

Acetylgalactosamine↗

Trichinella spp.: differential expression of acid phosphatase and myofibrillar proteins in infected muscle cells.

Major alterations are induced in muscle cells infected by either Trichinella spiralis or Trichinella pseudospiralis. To investigate the response of muscle to these infections we have analyzed the expression of acid phosphatase (ACP, EC 3.1.3.2), adult skeletal muscle myosin heavy chain, and muscle tropomyosin proteins in infected mouse skeletal muscle cells. Using T. spiralis-infected cells, we provide strong evidence that the tartrate-sensitive ACP of these cells was synthesized by the infected cell and localized in lysosomes. Isoenzyme analysis indicated that the ACP activity was of host muscle cell origin and the specific activity of this ACP was 2.5 times greater than that in associated inflammatory cells. Increased ACP activity was also demonstrated in muscle cells infected by T. pseudospiralis. In synchronized muscle infections, increased ACP activity was detected at 5 days post-muscle infection for both parasites. ACP activity was further increased in infected muscle cells at later times tested. This increased infected cell ACP activity represents the earliest positive enzyme marker yet described indicating expression of the infected cell phenotype. In contrast, myofibrillar proteins were not detected in muscle cells chronically infected by T. spiralis but were detected in muscle cells infected by T. pseudospiralis. Decrease in myofibrillar protein levels was detected by 10 days post-muscle infection by T. spiralis. The data presented demonstrate significant differences and similarities in the phenotypes of muscle cells infected by these two parasites and establish criteria that could facilitate identification of parasite factors that may be involved in these phenomena.

Acid Phosphatase↗

Cytogenetic evaluation of four canine mast cell tumors.

We evaluated four canine cutaneous mast cell tumors cytogenetically. All four tumors contained both hypodiploid and hyperdiploid cells, an increase in the number of metacentric chromosomes, exchange configurations, and cells showing loss of an X chromosome. All tumors contained metaphases with chromosome gaps and breaks at frequencies greater than observed spontaneous chromosome breaks in normal cultured canine peripheral blood lymphocytes. Three of the four tumors had a normal modal chromosome number of 78. The fourth tumor had a modal chromosome number of 93, which represented 15% of the cells evaluated from this tumor.

Animals↗

The giemsa banding pattern of canine chromosomes, using a cell synchronization technique.

Cytogenetic investigations of the domestic dog, Canis familiaris, were performed on the Doberman pinscher and two Boxer dogs. Conventional homogeneously stained and G-banded metaphases from peripheral blood lymphocyte cultures synchronized with amethopterin and bromodeoxyuridine were studied. These procedures permitted the unequivocal identification of all canine chromosomes. A canine chromosome idiogram was constructed on the basis of the G-banding pattern at the haploid 327-band resolution level. The secondary constrictions and tapering of the telomeric regions characteristic of several canine chromosomes are described. Q-, C-, and NOR-banding were also performed and the salient features are described. This karyotype should enhance the value of the canine species in cytogenetic investigations.

Animals↗

A novel Robertsonian translocation in a family of Walker hounds.

A 5-year-old female Walker hound was presented to the Washington State University Veterinary Teaching Hospital as a result of a narrowing of the vulva, which prevented natural breeding. All other physical and clinical findings were normal. Cytogenetic analysis disclosed a chromosome number of 77, with three metacentric chromosomes comprised of two X chromosomes and a Robertsonian translocation of two acrocentric autosomes, chromosomes 21 and 33. Cytogenetic analysis of two full-sister siblings with histories of absence of estrus disclosed one with the same translocation and one with a normal female chromosome constitution. The propositus was artificially inseminated with semen from a karyotypically normal male Walker hound and gave birth to nine live grossly normal pups, six females and three males. Another female pup was stillborn but was grossly normal. Cytogenetic analysis of the live pups disclosed that four (three males and one female) of the nine had the same translocation in all lymphocytes. The remaining five pups (five females) had normal female chromosome constitutions. The litter size was average for this breed. This is a previously unreported Robertsonian translocation in dogs.

Animals↗

Ultrastructural lesions of ovine GM1 gangliosidosis.

Ovine GM1 gangliosidosis, an inherited disease of sheep with deficiencies of beta-galactosidase and alpha-neuraminidase, storage of GM1 ganglioside, asialo-GM1 and neutral long chain oligosaccharides in the brain, autosomal recessive inheritance, and histopathologic lesions typical of lysosomal storage diseases, has been described recently. Selected tissues from two sheep with the condition and an age-matched control were examined by transmission electron microscopy to characterize the ultrastructural lesions. In all central and peripheral neurons, the majority of the cytoplasmic space was occupied by membrane-limited enlarged bodies judged to be lysosomes, with a resultant displacement of normal organelles. The neuronal lysosomes usually contained stacks and concentric whorls of lamellae of stored material with a periodicity of 25 to 75 nM. Individual lamellae consisted of fine, multilayered (three to 10, and occasionally more) bands. Less commonly, enlarged neuronal lysosomes contained fibrillogranular or electron dense material. Central nervous system microglia and peripheral nervous system satellite cells had less extensive storage of similar material within enlarged lysosomes, whereas oligodendrocytes, astrocytes, and Schwann cells were relatively unaffected. Hepatocytes and renal epithelial cells also had storage of less quantity than neurons, but within even larger lysosomes. In contrast to neuronal storage material, visceral storage consisted of vesicles containing fibrillogranular or electron dense material within a mostly electron lucent matrix with only occasional lamellae. Kupffer cells and macrophages from bone marrow were affected similarly to but less severely than hepatocytes and renal epithelial cells, whereas hematopoietic cells and chondrocytes were unaffected. Both neuronal and visceral storage were evident, but the neuronal storage was much more extensive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Primary and secondary lysosomes in megakaryocytes and platelets from cattle with the Chediak-Higashi syndrome.

The ultrastructure of lysosomes from megakaryocytes (MK) and platelets of cattle with the Chediak-Higashi syndrome (CHS) was characterized using acid phosphatase histochemistry with beta-glycerophosphate as substrate and cerium as a capturing agent. Acid phosphatase was localized in the trans aspect of the Golgi complex and/or granules in MK at all stages of maturation. Morphometric analysis of the diameter of each lysosome was performed on MK from CHS cattle and compared to MK from normal cattle. Lysosomes in CHS MK were neither enlarged nor different with respect to classification as secondary lysosomes, which composed 35% of the lysosomes in CHS MK. Lysosomes were demonstrated in 22% of the CHS platelet sections and appeared similar to those from normal cattle, 56% of them being classified as secondary lysosomes. Why lysosomes are not enlarged in bovine CHS MK and platelets, whereas they are enlarged in most other cell types, remains unknown.

Acid Phosphatase↗

Demonstration of secondary lysosomes in bovine megakaryocytes and platelets using acid phosphatase cytochemistry with cerium as a trapping agent.

The ultrastructure of lysosomes from bovine megakaryocytes (MK) and platelets was characterized using acid phosphatase cytochemistry with beta-glycerophosphate as substrate and cerium as a trapping agent. The technique was easily reproducible; cerium-phosphate precipitates were uniform, readily visualized, and there was a virtual absence of nonspecific reaction product. Acid phosphatase was localized in the trans aspect of the Golgi complex and/or granules of less than 50 nm to 650 nm diameters in MK at all stages of maturation. Forty percent of the MK lysosomes contained inclusions of variable shapes, sizes and electron-density and were classified as secondary lysosomes. Twenty-four percent of the platelet sections contained acid phosphatase-positive granules. Fifty-four percent of these were secondary lysosomes. This is the initial report demonstrating secondary lysosomes in either resting MK or platelets using acid phosphatase cytochemistry. These findings suggest that MK and platelet lysosomes have an intracellular function in resting MK and platelets.

Acid Phosphatase↗

Chediak-Higashi syndrome in the cat: prenatal diagnosis by evaluation of amniotic fluid cells.

Chediak-Higashi syndrome (CHS) is an autosomal recessive disease in humans, cats, and 8 other species. The homology of CHS in humans and cats has been demonstrated. Since human CHS is a progressive, serious, and eventually fatal disease, a method for prenatal diagnosis would be desirable. This study was designed to determine whether CHS could be diagnosed prenatally by examination of amniotic fluid cells. The amniotic fluid samples were obtained from CHS and control cat fetuses on the 45th day of gestation and cultures of cells were established. Because the underlying enzyme deficiency in CHS has not been identified, it was necessary to use a secondary manifestation of the syndrome in these studies. The secondary manifestation used was the characteristic enlargement of lysosomes associated with the disease. The lysosomes of these cells were stained by acid phosphatase histochemistry and the diameter of the largest lysosome in each cell was measured by light microscopy with a calibrated ocular micrometer. The diameters of the largest lysosomes in cells of normal fetuses ranged from 0.5 to 7.0 micron (means ranged from 0.9 to 1.8 micron), whereas the diameter of the largest lysosomes in the cells of CHS fetuses ranged from 0.5 to 30 microns (means ranged from 6.4 to 12.8 microns). The approximate t-test for independent samples with unequal variances disclosed that the largest acid phosphatase-positive lysosomes in amniotic fluid cells of CHS cat fetuses were significantly larger than the lysosomes in the cells of normal cat fetuses (P less than 0.0001). This information should, by extrapolation, provide the basis for the prenatal diagnosis of human CHS by amniocentesis.

Acid Phosphatase↗