Spontaneous Erythroid Leukemia in a 7-Week-Old Crl:CD (SD) Rat

A young male Crl:CD (SD) rat with erythroid leukemia that presented with emaciation, abdominal distension and a pale visible mucosal membrane was euthanized at 7 weeks of age. At necropsy, enlargement of liver, spleen and pancreatic lymph node was noted. Analysis of blood smear samples revealed many mono- or binucleated erythroblasts that had PAS-positive vacuoles in the cytoplasm. Histopathologically, neoplastic proliferation of atypical cells was observed in the hepatic sinusoids, splenic red pulp, bone marrow, pancreatic lymph node, kidney and lung. Neoplastic cells showed a round to spindle shape, and some neoplastic cells had deeply stained small nuclei and small cytoplasms and resembled erythroblasts. Immunohistochemically, many neoplastic cells were positive for hemoglobin. To our knowledge, this is the first report of erythroid leukemia in a rat of this age. The observed features were similar to those of pure erythroid leukemia in humans.     

Growth curve analyses in selected duck lines.

1. Growth patterns of male ducks from 4 lines (lines A, B, C and D) selected for market weight were analysed and compared to growth patterns of ducks in the respective line 7 generations earlier. Growth curves were analysed using procedures derived from the Weibull sigmoidal function and the linear-linear relative growth rate model and simple allometry. 2. The ducks were fed ad libitum under 24-h lighting throughout the experiment. At weekly intervals from the time of hatch through 70 d of age, 16 ducks from each line were killed to determine body, carcase, breast-muscle, leg and thigh-muscle, and abdominal fat weights. 3. Line A was the heaviest line, followed by line B, line C and line D. However, body weight, carcase weight and breast-muscle weight at 49 d of age were not significantly different between lines A and B. After 7 generations of selection, the breast-muscle yield was increased to >19% and the abdominal fat percent was reduced to <1.4% in all lines. 4. The Weibull growth curve analysis of body weight showed an increase in the asymptotes during selection, while the age of the inflection point remained constant in all lines (21.3 to 26.0 d). For breast-muscle growth, ducks reached the inflection point 12.8 to 14.3 d later than for body weight. Between line A and line B, asymptotes for body weight, asymptotes for breast-muscle weight and allometric growth coefficients of breast muscle and leg and thigh muscles from 14 to 49 d were not significantly different. 5. The relative growth rate model discriminated body and breast-muscle growth patterns of line A and line B. The initial decline in the relative body growth rate was less and the time to reach the transition was longer in line A than line B. On the other hand, the initial decline in the relative breast-muscle growth rate was greater in line A than line B.     

Cross-reactive antibodies to BLV and HTLV in bovine and human hosts with retrovirus infection

Sera of 22 cattle naturally infected with bovine leukemia virus (BLV), of 2 calves vaccinated with BLV, and of 22 patients with human T cell leukemia virus type I (HTLV-I) infection were tested to BLV and HTLV-I by enzyme-linked immunosorbent assay (ELISA) and Western blotting (WB). Sera of 22 healthy cattle and from 22 healthy persons, and mouse monoclonal antibody to BLV-gp51, to HTLV-I-p24, or to HTLV-I-p19 were also tested. Sera of virus-infected hosts gave significantly higher ELISA values than sera of healthy donors to both BLV and HTLV-I. The correlation between ELISA values of bovine sera to BLV and those to HTLV-I was r = 0.76, whereas that of human sera was r = 0.35. By WB and competitive WB assays, bovine sera that were ELISA-positive to BLV reacted with one or more of p12, p15, and p24 of BLV, and with only p24 of HTLV-I. Human sera that were ELISA-positive to HTLV-I reacted with p12 and p24 of BLV, and with one or more of p12, p15, p19, and p24 of HTLV-I. These results demonstrate that BLV and HTLV-I are capable of evoking cross-reactive immune response in at least some hosts under natural infection as well as by virus vaccination.     

Preservation of feline anti-Toxoplasma gondii antibody activity using blood absorbed on filter paper stored under different conditions

The present study deals with the successful long-term preservation of feline anti-Toxoplasma gondii antibody activity on filter paper strips stored with silica gel. When filter paper strips were kept at 25 degrees C with silica gel, antibody activity in blood samples was preserved for at least six months.     

The first record of sucking louse, Neohaematopinus callosciuri, infesting pallas squirrels in Japan

A species of sucking louse, Neohaematopinus callosciuri, was found for the first time in Japan. The species was found on an invasive species of squirrel, Pallas squirrel, Callosciurus erythraeus, in the Kamakura district, Kanagawa Prefecture, Japan. A total of 52 lice were obtained from 22 of 104 squirrels captured. The lice were about three times more prevalent in male squirrels than in females and were detected most frequently in the winter. As N. callosciuri has never been reported on wild animals in Japan, this species probably was introduced into Japan along with their host, Pallas squirrels.     

Molecular cloning of canine mucosal addressin cell adhesion molecule-1 cDNA and its expression in normal tissues

A cDNA encoding canine mucosal addressin cell adhesion molecule-1 (MAdCAM-1) was cloned. The entire open reading frame of canine MAdCAM-1 cDNA comprises 1137 bp, corresponding to 378 amino acid residues. The deduced amino acid sequence of canine MAdCAM-1 was 55.2%, 53.7%, and 52.4% identical to rat, mouse, and human MAdCAM-1, respectively. Canine MAdCAM-1 appeared to contain two immunoglobulin-like domains at the N-terminus, followed by a mucin-like domain and a third immunoglobulin-like domain. The structures of the dog, rat, and mouse proteins are likely similar because all of the cysteine residues in the immunoglobulin-like domains were conserved. Canine MAdCAM-1 mRNA was confirmed to express extremely in the mesenteric lymph node by RT-PCR.     

Cloning of canine Toll-like receptor 7 gene and its expression in dog tissues

Toll-like receptor 7 (TLR7) is activated by single strand RNA and imidazoquinoline compounds, and induces interferon production. In this study, canine TLR7 cDNA was cloned and sequenced. The full-length cDNA of canine TLR7 gene was 3419bp, encoding 1032 amino acids. The similarities of canine TLR7 with human and mouse TLR7 were 84 and 80% at the nucleotide sequence level, and 86 and 79% at amino acid sequence level, respectively. Further, the expression of TLR7 mRNA was investigated in canine normal tissues by semiquantitative RT-PCR analysis. The common expression level of TLR7 mRNA in tissues from three dogs examined was in large intestine, lung, pancreas, small intestine and skin, though the expression level in each tissue was varied among these healthy dogs. In other tissues (kidney, liver, lymph node, spleen, adrenal gland, and PBMCs), the level of TLR7 mRNA expression was different in individuals.     

C-reactive protein concentration in dogs with various diseases

To investigate the clinical utility of C-reactive protein (CRP) determination in dogs, its plasma concentration was measured by a laser nephelometric method in 928 dogs with various diseases, and was compared with other inflammatory parameters. CRP concentration was elevated in various inflammatory diseases, this was most frequently observed in cases with neoplastic and immune-mediated diseases. All cases of pyometra, panniculitis, acute pancreatitis, polyarthritis, and hemangiosarcoma showed significantly elevated CRP concentrations. On the other hand, the CRP concentration was elevated only in few cases of neurological diseases such as epilepsy, meningoencephalitis, and hydrocephalus and endocrine diseases such as hypothyroidism, hyperadrenocorticism, and diabetes mellitus. Only a weak correlation was observed between the CRP concentration and white blood cell (WBC) counts (r=0.44) but no correlation with band neutrophil counts. There was no correlation between the CRP and albumin concentrations, but a weak negative correlation (r=-0.40) when excluding chronic intestinal diseases and nephrotic syndrome, which can cause protein loss. Thus, CRP can be useful to detect inflammations that cannot be detected by WBC and, or band neutrophil counts, suggesting that the examination of CRP concentration is essential as routine diagnostic test.