Laboratory experiments have documented the effects of hormones and endocrine-disrupting compounds on mammary development in mammals. However, few observations of mammary hyperplasia have been ...presented for wild rodents. We describe hyperplastic mammary glands in a wild-caught white-footed mouse (Peromyscus leucopus) from an area contaminated with heavy metals.
Laboratory-raised cotton rats (
Sigmodon hispidus), outbred white mice (
Mus musculus), and C57BL/6J-Lyst
bg-J/J mice (
M. musculus) that were administered approximately 50 sporulated oocysts of
...Hepatozoon americanum (AF176836) by gavage developed inflammatory lesions containing parasitic cystozoites in cardiac and skeletal muscle, kidney, and lung. Sprague–Dawley rats (
Rattus norvegicus) similarly exposed showed no evidence of infection. Cystozoites were first detected by histopathologic examination four weeks after exposure to oocysts. Globular, PAS-positive material accumulated around the cystozoites as the duration of infection lengthened. Nested PCR analysis of tissues collected 16
weeks post-exposure was positive for the 18S rRNA
Hepatozoon sp. gene and the DNA sequence of the fragment amplified was 99.6% and 99.8% identical to
H. americanum sequences previously reported from naturally-infected dogs (AF176836 and AY864676, respectively). Merogonous and gamontogonous stages of the parasite were not detected in any of the cystozoite-infected rodents.
Anaplasma phagocytophilum, first identified as a pathogen of ruminants in Europe, has more recently been recognized as an emerging tick-borne pathogen of humans in the U.S. and Europe. A. ...phagocytophilum is transmitted by Ixodes spp., but the tick developmental cycle and pathogen/vector interactions have not been fully described. In this research, we report on the experimental infection of sheep with the human NY-18 isolate of A. phagocytophilum which then served as a host for infection of I. scapularis nymphs and adults. A. phagocytophilum was propagated in the human promyelocytic cell line, HL-60, and the infected cell cultures were then used to infect sheep by intravenous inoculation. Infections in sheep were confirmed by PCR and an Anaplasma-competitive ELISA. Clinical signs were not apparent in any of the infected sheep, and only limited hematologic and mild serum biochemical abnormalities were identified. While A. phagocytophilum morulae were rarely seen in neutrophils, blood film evaluation revealed prominent large granular lymphocytes, occasional plasma cells, and rare macrophages. Upon necropsy, gross lesions were restricted to the lymphoid system. Mild splenomegaly and lymphadenomegaly with microscopic evidence of lymphoid hyperplasia was observed in all infected sheep. Female I. scapularis that were allowed to feed and acquire infection on each of the 3 experimentally infected sheep became infected with A. phagocytophilum as determined by PCR of guts (80-87%) and salivary glands (67-100%). Female I. scapularis that acquired infection as nymphs on an experimentally infected sheep transmitted A. phagocytophilum to a susceptible sheep, thus confirming transstadial transmission. Sheep proved to be a good host for the production of I. scapularis infected with this human isolate of A. phagocytophilum, which can be used as a model for future studies of the tick/pathogen interface.
Dendritic cell leukemia in a Golden Retriever Allison, Robin W.; Brunker, Jill D.; Breshears, Melanie A. ...
Veterinary clinical pathology,
June 2008, 2008-Jun, 2008-06-00, 20080601, Letnik:
37, Številka:
2
Journal Article
Recenzirano
: An 8‐year‐old castrated male Golden Retriever was evaluated for decreased appetite, lethargy, and labored breathing of 1‐week duration. Bilateral pulmonary infiltrates, hepatomegaly, and ...splenomegaly were present. Results of a CBC revealed marked leukocytosis (62,600/μL; reference interval 4000–15,500/μL) and large numbers of atypical cells (30,700/μL) with abundant cytoplasm. There was no concurrent anemia, neutropenia, or thrombocytopenia. Morphology of the atypical cells was most consistent with a histiocytic origin. Similar cells were identified in bone marrow aspirates, and were morphologically suggestive of the macrophage variant of disseminated histiocytic sarcoma. However, flow cytometry of the abnormal circulating cells revealed CD1c, CD11c, and major histocompatibility complex (MHC) Class II expression without expression of CD11d or lymphoid markers, consistent with myeloid dendritic antigen‐presenting cells. At necropsy, the splenic architecture was effaced by neoplastic histiocytes that were also infiltrating lung, liver, an abdominal lymph node, myocardium, an bone marrow. Immunohistochemistry of the splenic neoplastic cells confirmed dendritic cell origin (CD1c+, CD11c+, MHC II+, no expression of CD11d and lymphoid markers). To the authors' knowledge, this is the first report of canine dendritic cell leukemia—in this instance accompanied by marked tissue infiltration.
A novel species of
Hepatozoon
was recently reported in cotton rats (
Sigmodon hispidus
) collected from an area of Oklahoma where American canine hepatozoonosis is endemic. In this study, the various ...stages of merogony of the parasite were characterized by light and electron microscopy. Meronts occurred within parasitophorous vacuoles in hepatocytes and ranged from mononucleated spherical forms to large, mature forms in vacuoles that contained approximately 50 peripherally arranged merozoites. Developing merozoites had characteristic apicomplexan organelles, including anterior and posterior polar rings, a conoid, microtubules, rhoptries, micronemes, and a trilaminar membrane. As the meronts matured, numerous curvilinear merozoites budded from a residual body. This morphologic characterization extends our understanding of this novel
Hepatozoon
and adds information about the hepatozoa, apicomplexan parasites that infect numerous species.
Pathology in Practice Breshears, Melanie A.; Brunker, Jill D.
Journal of the American Veterinary Medical Association,
03/2011, Letnik:
238, Številka:
6
Journal Article
Pathology in practice. Chronic kidney failure Breshears, Melanie A; Brunker, Jill D
Journal of the American Veterinary Medical Association,
2011-Mar-15, 20110315, Letnik:
238, Številka:
6
Journal Article
To identify any adverse effects on health or performance in young dairy calves fed clinoptilolite mixed with milk replacer.
26 male Holstein calves (1 to 7 days old).
Twice daily for 28 days, calves ...were fed milk replacer with no clinoptilolite (control group; n=8), 0.5% clinoptilolite (low-dosage group; 9), or 2% clinoptilolite (high-dosage group; 9); each calf consumed approximately 12% of its body weight (based on the replacer solids in the milk replacer mixture)/d. For each calf, subjective health assessments, weight and rectal temperature measurements, and CBC and serum biochemical analyses were performed at intervals. All calves underwent necropsy.
2 calves were euthanized during the experiment because of bronchopneumonia or enteritis. Body weight and average daily gain did not differ among treatment groups. The percentage of monocytes and serum total protein concentration in the low-dosage group were higher than values in the control and high-dosage groups. Compared with values for either clinoptilolite-treated group, BUN concentration was greater in the control group. Serum globulin concentration differed significantly among groups (2.77, 2.50, and 2.36 g/dL in the low-dosage, control, and high-dosage groups, respectively). At necropsy, gross lesions associated with clinoptilolite treatment were not detected in any of the calves.
Even under stressful conditions, clinoptilolite fed at low or high dosages did not affect the performance of dairy calves and had no negative effect on WBC count and blood metabolite concentrations and enzyme activities. Clinoptilolite ingestion was not associated with treatment-specific gross changes.
What Is Your Diagnosis? Simpson, Katharine M.; Streeter, Robert N.; Wall, Corey R. ...
Journal of the American Veterinary Medical Association,
11/2013, Letnik:
243, Številka:
10
Journal Article
