Oligodendroglial gliomatosis cerebri in a poodle.

Gliomatosis cerebri (GC) is a rare, diffusely infiltrating, glial cell tumour of neuroepithelial origin. This report describes a case of oligodendroglial GC in a 6-year-old male Poodle with central nervous system symptoms. Computed tomography revealed anomalous parenchyma density and ventricular asymmetry. Cerebrospinal fluid showed elevated protein (30 mg dL(-1)) and nucleated cell count (20 µL(-1)). Presumptive diagnosis of necrotizing meningoencephalitis was made. Because of rapid deterioration of the general condition of the animal, the dog was euthanized. Histologically there was an infiltration of round or ovoid neoplastic cells in the white matter of the left cerebral hemisphere and in leptomeninges. Immunohistochemistry showed that 80% of the neoplastic cells expressed Olig2 and some 50% expressed glial fibrilary acidic protein. On the basis of clinical, histological and immunohistochemical features, a diagnosis of oligodendoglial GC was done. This case represents the first report of a case of oligodendroglial GC in the canid.

A joint myxoma in a dog.

Myxomas of the joints are extremely rare in domestic animals, only four cases, all in dogs, having been reported previously. This paper describes a myxoma originating from the synovium of the right radiocarpal joint of a mature female Dobermann pinscher with right front limb lameness. The tumour was excised surgically and no recurrence was detected during a 2-year follow-up period. Immunohistochemically, the tumour cells reacted with antibodies to vimentin and S100 protein but not with antibodies to cytokeratins (high and low molecular weight) or human callus keratin.

Immunohistochemical analysis of estrogen receptors in feline mammary gland benign and malignant lesions: comparison with biochemical assay.

Estrogen receptors (ER) were determined by both the biochemical dextran-coated charcoal (DCC-ER) and the immunohistochemical Avidin biotin-peroxidase complex (IHC-ER) methods in proliferative mammary lesions collected from 37 cats: 20 malignant tumors without metastasis at first presentation, seven malignant tumors with lung and/or lymph node metastases and 10 benign tumors and dysplasias. Total number of samples analyzed by both methods was 44. The DCC-ER method was applied to frozen tissue samples and the IHC-ER method was applied to neutral buffered formalin-fixed, paraffin wax-embedded tissue samples by using the NCL-6F11 monoclonal antibody. Biochemically, 21 (47.7%) cases had equal or more than 5 fmol/mg of protein (standard positivity threshold). Immunohistochemically, 11 (25%) cases were scored positive, the percentage of positive nuclei being statistically linked to the intensity of immunostaining. Normal mammary gland tissue (13 cases) and/or dysplastic areas (5 cases) found in the surroundings of the main lesion were IHC-ER positive in 76.9% and 40% of the cases, respectively. Concordance between DCC-ER and IHC-DCC was 72.7% and the results of the DCC and the IHC-ER methods were significantly correlated (P < 0.05) by the chi2 test. Specificity (true negatives) and sensitivity (true positives) of the ICH-ER method were 95.6% and 47.6%, respectively. One out of eleven DCC-ER positive and IHC-ER negative discordant cases (9.09%) was a DCC-ER false positive, because the surrounding normal mammary gland tissue was IHC-ER positive. The remaining 10 cases had ER content values equal or lower than 23 fmol/mg of protein, a figure that could represent the sensitivity threshold of the immunohistochemical method employed.

Liver pathology and immune response in experimental Fasciola hepatica infections of goats.

The relationship between the immune response and the pathogenesis of the disease was studied in different primary and secondary experimental Fasciola hepatica infections of goats. The establishment of the infection, measured as percentage of recovered flukes at the necropsy, was similar in primarily and secondarily infected animals (between 19.7% and 24.3%), but the hepatic damage was much more severe in secondarily infected goats, as revealed by the levels of serum hepatic enzymes GGT and LDH. Primary infection evolves to chronic fasciolosis that did not induce the development of resistance, since goats were highly susceptible to secondary infection, showing severe acute and chronic hepatic lesions that led to the death of some animals in each group. The immune response to the infection was proved by the production of specific IgG antibodies to ESP of F. hepatica and the involvement of CD3+ T lymphocytes and lambda IgG+ plasma cells in the hepatic infiltrate. Secondary infection did not induce any difference in either IgG response or in the cellular composition of the infiltrate of hepatic lesions, although this was much more extended. However, neither antibodies nor cell-mediated response were protective: there was no correlation between IgG levels and fluke burden and there was no evidence of cell-mediated killing of the parasite. This suggests the existence of some immune evasion mechanisms in goat infection with F. hepatica. The parasite may depress the local inflammatory and immune response, as suggested by the scarcity of CD3+ T cells in the infiltrate surrounding acute migratory tunnels. Moreover, in secondary infected goats can be suspected an immunological damage of the liver, since a very severe infiltrate of immune cells replaced wide areas of hepatic parenchyma and an immune-mediated damage of hepatocytes could occur.

Immunohistochemical study of the local immune response to Fasciola hepatica in primarily and secondarily infected goats.

The distribution of CD2, CD4, CD8, gamma/delta T-lymphocytes, B-cells and IgG lambda-light chain (lambda-IgG) containing cells were analysed in the inflammatory infiltrate associated to hepatic lesions and gallbladder (HL), and in hepatic lymph nodes (HLN) of goats primarily and secondarily infected with Fasciola hepatica. In the HL, CD2 and CD8 T-cells were more numerous (p=0.01) in secondarily rather than in primarily infected goats, whereas CD4 T-lymphocytes were less numerous than CD8 and showed no significant change in both groups. The ratio CD4/CD8 was 0.66 and 0.39 for primarily and secondarily infected goats, respectively. In contrast, in the HLN, CD4 were more numerous than CD8 T-cells, the ratio CD4/CD8 was 2.0 in control, 1.5 and 1.3 in primary and secondary infections, respectively. Gamma/delta T-lymphocytes were scarce in the HL and moderate in the HLN of both primarily and secondarily infected animals. B-cells (IgM+, lambda-IgG+ or CD79+) varied from scarce or moderate in the HL to abundant in the HLN, where CD79+-cells were mainly located in lymphoid follicles and IgM and IgG in plasma-cells of the medullary cords, suggesting an intense local humoral immune response. However, this response did not prevent the hepatic damage in secondarily infected goats, in which hepatic lesions were more severe than in primarily infected ones.

Immunohistochemical detection of hog cholera viral glycoprotein 55 in paraffin-embedded tissues.

Formalin-fixed, paraffin embedded tissues obtained from 40 pigs inoculated with a field isolate of hog cholera virus were examined for the presence of Gp55, a major structural protein of the virus envelope, using a monoclonal antibody-based immunohistochemical test with the avidin-biotin-peroxidase complex method. Immunoreactivity was detected in hog cholera virus-infected tissues but not in control pigs tissues, African swine fever virus-infected tissues, or bovine viral diarrhea virus-infected porcine or bovine tissues. The first positive reactions were seen in lymphatic tissues, digestive tract and skin on postinoculation day (pid) 4, respiratory and urinary tissues on pid 5, nervous tissues on pid 6, and endocrine tissues on pid 7. These staining reactions persisted until the last observation on pid 18. Hog cholera virus antigen was not detected in heart tissue at any time. The highest levels of antigen detection were found in tonsils, spleen, and pancreas, although the esophageal mucosa and skin epithelial cells were also intensely and widely stained. The cellular staining pattern of Gp55 had a ubiquitous distribution. It was found in epithelial cells, macrophages and circulating monocytes, endothelial cells, lymphoid cells, and glial cells. The results showed a high specificity and high sensitivity for detecting hog cholera Gp55 in formalin-fixed, paraffin embedded tissue samples. This method allows precise association of Gp55 with specific cells, tissues, and histologic lesions, making the technique suitable for use in routine diagnosis of hog cholera.

Application of enzyme-immunohistochemistry for the diagnosis of aspergillosis, candidiasis, and zygomycosis in three lovebirds.

Aspergillosis, candidiasis, and zygomycosis were diagnosed in tissues from three lovebirds (Agapornis roseicollis) using indirect enzyme-immunohistochemical techniques. In these techniques, the first antibody was raised against fungal antigen. A second antibody, which was raised in another animal species, was added to link the first antibody to enzyme-immunocomplexes. The reactivity of specific monoclonal and polyclonal antibodies was visualized by immunoreactivity of alkaline phosphatase anti-alkaline phosphatase and peroxidase anti-peroxidase immunocomplexes. All three birds examined had dermal candidiasis. In addition, one of the birds was diagnosed with concomitant acute ocular aspergillosis, and another bird was diagnosed with chronic zygomycotic myocarditis.

Galactorrhea associated with lymphocytic adenohypophysitis. Case report.

A young woman, 14 months post partum, committed suicide when she noticed milk discharging from her nipples and thought she was pregnant. At autopsy the uterus was found to be non-gravid and the pituitary gland enlarged. Histological examination revealed lymphocytic adenohypophysitis, a rarely identified condition usually associated with hypopituitarism. Immunoperoxidase studies of the pituitary demonstrated prolactin cell hyperplasia. None of the other known causes of galactorrhea was present suggesting that this may be a new addition to the differential diagnosis of galactorrhea. To this date lymphocytic adenohypophysitis has been reported only in women, the majority within 14 months postpartum, and is usually identified only at autopsy.