Disseminated histiocytic sarcoma with peripheral blood involvement in a Bernese Mountain dog

Abstract: A 6‐year‐old Bernese Mountain dog was presented with a history of lethargy and weight loss of 2 weeks duration. On physical examination the dog had pale mucous membranes and tachypnea. Ultrasound examination revealed hepatomegaly, splenomegaly, and mesenteric lymphadenomegaly. Results of a CBC included marked normocytic normochromic nonregenerative anemia, marked thrombocytopenia, and moderate leukocytosis with mild neutrophilia and a large population of unclassified round cells (6.2 × 10³/μL). The unclassified cells occasionally were bi‐ or multinucleated and had variably abundant pale basophilic cytoplasm that contained multiple irregular clear vacuoles and occasionally erythrocytes. Fine needle aspirate specimens of the mesenteric lymph nodes and spleen were composed of a population of round pleomorphic cells with the same features as the circulating cells. On flow cytometric analysis of peripheral blood, the unclassified cells expressed CD18, CD45, CD11c, CD1c, and CD14; immunocytochemical analysis of blood smears also indicated the cells were positive for CD1c, CD1a, and CD11c. The dog died a few hours after referral. The histologic interpretation of samples collected from spleen, liver, and lymph nodes was malignant neoplasia of histiocytic origin. Immunohistochemical staining yielded negative results for CD11d, a marker of red‐pulp macrophages, ruling out hemophagocytic histiocytic sarcoma. Based on clinical and pathologic findings, the final diagnosis was disseminated histiocytic sarcoma (DHS) with peripheral blood involvement. To our knowledge, DHS in a dog with evidence and immunophenotyping of neoplastic cells in peripheral blood has been reported only rarely.     

T-cell-rich B-cell lymphoma in a ring-tailed lemur (Lemur catta).

A 13-yr-old ring-tailed lemur (Lemur catta) was evaluated for depression, anorexia, polyuria, and polydipsia. The lemur was in poor body condition and was anemic, hypoalbuminemic, and hyponatremic. Cytologic examination of aspirates of the spleen, liver, and bone marrow and histopathologic examination of liver and bone marrow biopsies revealed a disseminated round cell tumor. After euthanasia, necropsy revealed hepatomegaly, splenomegaly, and mesenteric lymphadenomegaly. Neoplastic cells were present within the spleen, liver, kidneys, multiple lymph nodes, bone marrow, lung, small intestine, pancreas, and testicle and were composed of large anaplastic round cells in a background of small well-differentiated lymphocytes. Immunohistochemical analysis revealed that the small well-differentiated lymphocytes labeled for the anti-human T-cell marker, CD3, and the large anaplastic round cells labeled with the anti-human B-cell marker, CD79a. On the basis of the immunohistochemical staining results and morphologic appearance, a diagnosis of a T-cell-rich B-cell lymphoma was made.     

Multicentric t-cell lymphoma in a dromedary camel (Camelus dromedarius).

A 7-yr-old female dromedary camel (Camelus dromedarius) was evaluated for inappetence, weight loss, polyuria, and polydipsia. The animal did not respond to antibiotic and supportive therapy, became recumbent, and died. Gross examination revealed nodules in the liver, mesenteric and perirenal lymph nodes, and both kidneys, with segmental thickening of the small intestine. Histopathologic examination revealed multifocal lymphoma with moderate mitotic activity. Immunohistochemical staining of neoplastic cells was uniformly CD3-positive, indicating a T-cell lymphoma.     

B‐cell lymphoma with Mott cell differentiation in two young adult dogs

Abstract: Two young adult dogs with gastrointestinal signs were each found to have an intra‐abdominal mass based on physical examination and diagnostic imaging. On exploratory laparotomy, small intestinal masses and mesenteric lymphadenopathy were found in both dogs; a liver mass was also found in dog 1. Cytologic and histologic examination of intestinal and liver masses and mesenteric lymph nodes revealed 2 distinct lymphoid cell populations: lymphoblasts and atypical Mott cells. With Romanowsky stains, the atypical Mott cells contained many discrete, clear to pale blue cytoplasmic inclusions consistent with Russell bodies that were positive by immunohistochemistry for IgM and CD79a in both dogs and for IgG in dog 2. The Mott cells and occasional lymphoblasts stained strongly positive with periodic acid‐Schiff. Using flow cytometric immunophenotyping in dog 1, 60% of peripheral blood mononuclear cells and 85% of cells in an affected lymph node were positive for CD21, CD79a, IgM, and MCH II, indicative of B‐cells. With electron microscopy, disorganized and dilated endoplasmic reticulum was seen in Mott cells in tumors from both dogs. Antigen receptor gene rearrangement analysis of lymph node and intestinal masses indicated a clonal B‐cell population. Based on cell morphology, tissue involvement, and evidence for clonal B‐cell proliferation, we diagnosed neoplasms involving Mott cells. To the authors' knowledge, this is the second report of Mott cell tumors or, more appropriately, B‐cell lymphoma with Mott cell differentiation, in dogs. More complete characterization of this neoplasm requires further investigation of additional cases. This lymphoproliferative disease should be considered as a differential diagnosis for canine gastrointestinal tumors.     

Comparative effects of fluoroquinolones on subsets of T lymphocytes in normothermic and hyperthermic mice

The subsets of T lymphocytes in thymus, spleen and mesenteric lymph nodes were investigated in normothermic and hyperthermic mice treated with fluoroquinolones administered orally six times at 24 h intervals at doses of 15 or 75 mg/kg (flumequine, norfloxacin and ciprofloxacin) and 5 or 25 mg/kg (enrofloxacin). It has been found that fluoroquinolones can modulate CD3+, CD4+ and CD8+ marker expression on thymocytes, splenocytes and lymphocytes of mesenteric lymph nodes. Flumequine (15 mg/kg) decreased the percentage of immature CD4+CD8+ thymic cells and increased the percentage of mature CD4+ and CD8+. When the dose of flumequine was increased to 75 mg/kg a reduction in the maturation of thymocytes was observed. Administration of flumequine, norfloxacin and ciprofloxacin, irrespective of doses applied, increased the percentages of CD3+ splenocytes of CD4+ spleen cells. Exposure to enrofloxacin decreased the percentage of T helper-inducer cells. Flumequine and ciprofloxacin augmented the percentage of CD3+ mesenteric lymph node cells and increased the percentage of CD8+ cells. In contrast, norfloxacin and enrofloxacin decreased the percentage of CD3+ mesenteric lymph node cells and the percentage of CD4+ cells. Lipopolysaccharide (LPS) from E. coli (25 micro g/mouse) increased the percentage of single-positive CD4+ thymocytes, but did not affect the percentage of CD3+, CD4+ and CD8+ splenocytes and mesenteric lymph node cells. Flumequine and ciprofloxacin administered to mice pior to LPS potentiated its stimulant effect on the maturation of thymic cells ( increased percentage of mature CD4+ and CD8+ thymocytes). Pre-treatment with norfloxacin or enrofloxacin either reduced or did not modify the stimulant effect of LPS on maturation of thymic cells. Flumequine, norfloxacin, enrofloxacin and ciprofloxacin administered prior to LPS decreased the percentage of CD8+ splenocytes and increased the percentage of CD4+ spleen cells. Norfloxacin and ciprofloxacin at a dose of 75 mg/kg reduced the percentage of CD8+ mesenteric lymph node cells in hyperthermic mice. Pretreatment with norfloxacin at a dose of 15 mg/kg augmented the percentage of mesenteric lymph node cells. It was concluded that the modulating effects of fluoroquinolones depends on the chemial structure of drugs, dose administered as well as immunologic status.     

Effect of vitamin E supplementation on lymphocyte distribution in gut-associated lymphoid tissues obtained from weaned piglets

Fifteen piglets were used to determine the effect of vitamin E supplementation on the number of CD4-immunoreactive (CD4+) T-lymphocytes, CD8-immunoreactive (CD8+) T-lymphocytes and IgA-immunoreactive (IgA+) B-lymphocytes per follicle in the Peyer's patch of distal ileum and the mesenteric lymph nodes of weaned piglets. Piglets, following a 3-day adaptation period after weaning, were assigned to one of three experimental groups: control (no vitamin E supplementation), vitamin E supplementation of 100 mg/kg of diet and vitamin E supplementation of 300 mg/kg of diet. Supplementation of vitamin E lasted for a period of 36 days. The basal diet contained 80 mg alpha-tocopherol/kg of diet. All piglets were killed at day 39 after weaning and samples of the distal ileum and adjacent mesenteric lymph nodes were collected. The number of cells for each lymphocyte subset was counted in the Peyer's patch and the mesenteric lymph nodes follicles, in cryostat sections processed for immunohistochemistry. Results showed that vitamin E supplementation (300 mg/kg diet) of piglets caused an increase (P < 0.05) in the number of IgA+ B-lymphocytes in the Peyer's patch, but not in the mesenteric lymph nodes, compared with the corresponding values in control animals. Vitamin E supplementation had no effect (P > 0.05) on the number of CD4+ and CD8+ T-lymphocytes in the follicles of the Peyer's patch and the adjacent mesenteric lymph nodes. Thus, vitamin E had relatively minor effects on distribution of the major immunocompetent cells in the gut. The numbers of CD4+ and CD8+ T-lymphocytes as well as IgA+ B-lymphocytes per follicle were higher by 26-77% (P < 0.05) in the mesenteric lymph nodes than the corresponding values in the Peyer's patch.     

Acute megakaryoblastic leukemia in a German Shepherd dog

Abstract: An 11‐year‐old spayed‐female German Shepherd dog was presented to the Veterinary Medical Teaching Hospital at Kansas State University with a history of weight loss, anorexia, depression, and lethargy for 2–3 weeks. Radiographic examination revealed a mass in the spleen and several round radiodense foci in the liver. CBC results included normocytic normochromic anemia, marked thrombocytopenia, and low numbers of neoplastic cells that frequently had cytoplasmic projections or blebs. A bone marrow aspirate contained about 80% neoplastic megakaryoblasts with the same microscopic features as those observed in peripheral blood. Using flow cytometry, cells of large size were identified in peripheral blood that expressed CD41/61, CD45, CD61, and CD62P (P‐selectin) and were negative for markers of T cells, B cells, monocyte/macrophages, and dendritic cells. Because of the poor prognosis, euthanasia and subsequently necropsy were performed. On histopathologic examination, neoplastic megakaryoblasts were identified in spleen, liver, mesenteric lymph node, and the pulmonary vasculature. Using immunohistochemistry, the neoplastic megakaryoblasts weakly expressed von Willebrand factor. Based on microscopic and immunophenotypic findings, a diagnosis of acute megakaryoblastic leukemia (AMegL) was made. To our knowledge, this is the first report of AMegL in a domestic animal in which immunophenotyping by flow cytometry and a panel of antibodies against CD41/61, CD61, and CD62P were used to support the diagnosis.     

Thymic lymphosarcoma of T cell lineage in a koala (Phascolarctos cinereus)

Objective To diagnose and characterise thymic lymphosarcoma in a koala.
Design A pathological case.  

Animal

Seven-year-old female koala.
Procedure The neoplastic process was investigated macroscopically, haematologically, histologically and immunohistologically.
Results The koala had difficulty swallowing because of a medial swelling in the lower neck. Biopsy of this mass and blood examination revealed lymphosarcoma with a leukaemic manifestation; necropsy and histopathological examination showed the mass to be thymus. Palatine tonsils, cervical, axillary and mesenteric lymph nodes, spleen, liver, gut, bronchi, genitalia and bone marrow were infiltrated by neoplastic cells. Immunohistological staining of the thymic mass, cervical and mesenteric lymph nodes, bone marrow, spleen and gut revealed the neoplastic cells to be of T lymphocyte origin (positive for both anti-human CD3 and CD5).  

Conclusions

It is speculated that the neoplastic process originated in the thymus and was disseminated by bloodborne neoplastic cells: This first report of thymic lymphosarcoma in a marsupial confirms that antibodies raised originally to investigate human lymphoid neoplasia can cross-react with neoplastic lymphocytes in koalas.     

Johne's Disease (Paratuberculosis) in Goats: A Report of Eight Cases in Quebec

Johne's disease (paratuberculosis) is reported in eight goats. Clinical signs were mainly those of a chronic wasting disease which lead to emaciation, severe weakness, prostration and death. Soft pasty stool and/or profuse diarrhea were observed only after several weeks of illness, in the terminal stages of the disease, in six of the eight goats. Gross lesions were characterized by emaciation and mesenteric lymphadenopathy with more or less extensive areas of caseous necrosis and calcification. Gross lesions in the intestinal tract were limited to a mild thickening and corrugation of the mucosa of the distal small intestine, cecum and proximal parts of the colon in three of the affected animals. Caseous necrosis of Peyer's patches and ulceration were observed in two goats when small tuberculoid nodules were present in the liver of another one. Histologically, the intestinal lesions were characterized by accumulations of large foamy or vacuolated macrophages in the intestinal mucosa. Lesions were usually mild and multifocal in the proximal and middle parts of the small intestine, more diffuse and severe in the distal jejunum, ileum and proximal parts of the colon. Several of the macrophages infiltrated in the intestinal mucosa and mesenteric lymph nodes were packed with acid fast bacilli. Observations made on these animals stress the importance of a careful histological examination of the intestines and mesenteric lymph nodes of adult goats submitted to necropsy because of a chronic wasting disease.     

Modulatory effects of chitosan adipate on the T and B lymphocyte subsets in mice

This study examined the subsets of T lymphocytes in the thymus, spleen and mesenteric lymph nodes as well as the subsets of B lymphocytes in the spleen and mesenteric lymph nodes in mice administered chitosan adipate (20 mg/kg) intraperitoneally once or four times at 24 h intervals. The results showed that chitosan adipate decreased the percentage of immature CD4⁺CD8⁺ thymic T cells and increased the percentage of mature CD4⁺ and CD8⁺ thymocytes. The most significant stimulating effect was observed after four injections. A single exposure to chitosan adipate increased the percentage of CD4⁺ mesenteric lymph node cells, but four injections of the drug increased the percentage of CD4⁺ and CD8⁺ mesenteric lymph node cells. Chitosan adipate had no effect on the subset of splenic T cells. In contrast, chitosan adipate administered either once or four times increased the percentage of CD19⁺ splenocytes but had no effect on the percentage of CD19⁺ mesenteric lymph node cells. Overall, chitosan adipate induces the maturation and differentiation of thymocytes, and regulates the number of B splenic cells and lymph node T cells irrespective of the number of doses.     

Influence of bestatin, an inhibitor of aminopeptidases, on T and B lymphocyte subsets in mice

Bestatin, a low-molecular weight dipeptide, is a potent inhibitor of aminopeptidase N which has been demonstrated to have antitumor and immunomodulatory effects. The effects of bestatin (10, 1 and 0.1 mg/kg) administered intraperitoneally once, five or ten times to mice on the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets (CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes were studied. It has been found that bestatin administered ten times at doses of 10, 1 and 0.1 mg/kg increased the total number of thymocytes, splenocytes and lymphocytes of mesenteric lymph nodes. Bestatin also changed the percentage and the absolute number of T cell subsets in the thymus and T and B lymphocytes in the peripheral lymphatic organs. Five and ten exposures to bestatin (10, 1 and 0.1 mg/kg) increased the absolute count of both immature CD4+CD8+ and CD4-CD8- thymic cells. Moreover, both a single and multiple administration of bestatin (1 and 0.1 mg/kg) decreased the percentage and absolute count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Both a single and multiple administration of bestatin at all the doses under investigation augmented the percentage and the absolute count of CD19+ (B lymphocytes) in the peripheral lymphatic organs. The results of the study show that there is a relationship between the effect induced by bestatin and the dose of the drug as well as the number of doses applied. The strongest effect on the T and B lymphocyte subsets was noted after five injections of bestatin at doses of 1 and 0.1 mg/kg.     

Influence of betulinic acid on lymphocyte subsets and humoral immune response in mice

Betulinic acid is a pentacyclic triterpene found in many plant species, among others, in the bark of white birch Betula alba. Betulinic acid was reported to display a wide range of biological effects, including antiviral, antiparasitic, antibacterial, anticancer and anti-inflammatory activities. The effects of betulinic acid (50, 5, 0.5 mg/kg) administered orally five times at 24 hours intervals to non-immunized and red blood cells (SRBC)-immunized mice were determined. The present study examined the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes, and the percentage of subsets of T cells (CD4+CD8+, CD4CD8, CD4+, CD8+) in thymus,T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes, as well as white blood cell (WBC) and differential leukocyte counts in non-immunized mice, and humoral immune response in SRBC-immunized mice. SRBC was injected 24 hours after administration of the last dose of betulinic acid. It was found that betulinic acid administered orally five times at the dose of 0.5 mg/kg increased the total number of thymocytes, splenocytes, lymphocytes of mesenteric lymph node cells, and the weight ratio of the spleen and mesenteric lymph nodes in non-immunized mice. Betulinic acid also changed the percentage of T cell subsets in the thymus and T and B lymphocytes in peripheral lymphatic organs. The effects of betulinic acid on T and B cell subpopulations depended on the dose applied. The strongest stimulating effect of betulinic acid was observed when the drug was administered at the dose of 0.5 mg/kg. Five exposures to betulinic acid (0.5 mg/kg) decreased the percentage of immature CD4+CD8+ thymic cells with corresponding increases in the percentage and absolute count of mature, single-positive CD4+ thymocytes and decreased the percentage and total count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Multiple administration of betulinic acid at the investigated doses augmented the percentage and absolute count of CD19+ cells in the peripheral lymphatic organs. Moreover, betulinic acid at the dose of 5 mg/kg administered prior to SRBC immunization increased the number of plaque forming cells (PFC) but decreased the production of anti-SRBC antibodies on day 4 after priming. Thus, betulinic acid is a potential biological response modifier and may strengthen the immune response of its host.     

Modulatory effects of calf thymus extract on the subset of T lymphocytes in Trichinella spiralis-infected mice

The immunotropic properties of calf thymus extract (TFX-Jelfa) is connected with the mimic action of the thymus to modulate the differentiation, maturation and function of prothymocytes and mature thymus dependent (T) cells. The studies were carried out on CFW male mice aged 3 months. The animals were infected per os with 200 larvae of Trichinella spiralis. TFX-Jelfa was administered i.p. at a dose of 10 mg/kg seven times at 24 hour intervals prior to infection. The percentage of CD4+ and CD8+ in suspension of splenocytes and mesenteric lymphonode cells by flow cytometry using monoclonal antibodies coupled with fluorescein isothiocyanate (FITC) or phycoerythrin (PE) were determined. At the same time, cryostat preparations, made from jejunum and muscle samples, were examined by the direct immunofluorescence method using FITC-labeled antibody to mouse CD4+ and CD8+. It has been found that infection with T. spiralis in mice decreases the percentage of CD8+ splenocytes, while the percentage of CD8+ mesenteric lymphonode cells does not change. However, in infected mice the percentage of CD4+ spleen cells and mesenteric lymphonode cells is increased. It has been also found that during the course of infection an increase in the number of CD8+ and CD4+ cells in the basal lamina propria of the intestines was observed. In infected mice, CD4+ lymphocytes were visible in the inflammatory infiltrates of the muscle tissue on the 14th day, whereas CD8+ lymphocytes were first observed a week later. Pretreatment with TFX does not change the inhibitory effect of infection on the percentage of CD8+ splenocytes, but potentiates the percentage of CD4+ spleen cells and mesenteric lymphonode cells increased by infection. Furthermore, administration of TFX prior to infection also potentiates the stimulatory effect of T. spiralis on the number of CD8+ and CD4+ in the basal lamina propria of the jejunum, and on the number of CD8+ cells in the inflammatory infiltrates of the muscle tissue.     

Comparative studies on the distribution and population of immunocompetent cells in bovine hemal node, lymph node and spleen

The distribution and population of immunocompetent cells in bovine hemal node, mesenteric lymph node and spleen were analyzed comparatively by immunohistochemistry and flow cytometry. Many CD8(+) cells, CD172a(+) cells and γδ T cells were found in the lymphatic cord along the sinus of the hemal node and the splenic red pulp. A few CD8(+) cells and γδ T cells were distributed diffusely in the paracortex and medullary cord of the mesenteric lymph node. Many germinal centers were recognized in the lymphatic regions such as the cortex and white pulp of these lymphoid organs. The populations of CD8(+) cells and γδ T cells in the hemal node and the spleen were higher than those of the mesenteric lymph node. In addition, the populations of CD21(+) cells and MHC class II(+) cells in the hemal node and the mesenteric lymph node were higher than those of the spleen. The results suggest that the hemal node has an important role in both cellular and humoral immunity as well as the lymph node and the spleen in cattle.     

Nonsuppurative meningoencephalitis associated with Aleutian mink disease parvovirus infection in ranch mink.

Severe nonsuppurative meningoencephalitis associated with Aleutian mink disease parvovirus (ADV) infection was observed in adult ranch mink. Brain lesions included severe, locally extensive to coalescing lymphoplasmacytic meningoencephalitis with accompanying gliosis, satellitosis, and mild extension of inflammation into the leptomeninges. ADV was identified in mesenteric lymph node, spleen, brain, and liver of affected mink by polymerase chain reaction techniques. Sequences of the ADV isolate (TH5) revealed 2 unique residues in the region of the viral genome that determines pathogenicity. These findings suggest that certain strains of ADV may preferentially cause disease in the nervous system. ADV infection should be considered in the differential diagnosis of neurologic disorders in mink.     

Feline large granular lymphocyte (LGL) lymphoma with secondary leukemia: primary intestinal origin with predominance of a CD3/CD8(alpha)(alpha) phenotype

Clinicopathologic and immunophenotypic characteristics of large granular lymphocyte (LGL) neoplasia in 21 cats were examined. All cats were domestic short (19) or long hair (2) with a mean age of 9.3 years at diagnosis. Increased peripheral blood LGL counts were present in 18/21 cats. Neutrophilia (12/21 cats) and increased serum liver enzymes (7/12), total and direct bilirubin (7/13), BUN (5/14), and creatinine (2/14) were observed. Cats usually presented with advanced disease and none survived longer than 84 days (mean 18.8 days) postdiagnosis. Cytologically, LGLs had a mature (6/21), immature (13/21), or mixed (2/21) morphology. Necropsy lesions consisted of neoplastic lymphoid infiltrates in the jejunum, ileum, and duodenum in decreasing order of frequency. In the small intestine, mucosal ulceration (9/13) and epitheliotropism of neoplastic cells (9/13) were common. Neoplastic infiltrates were also present in the mesenteric lymph nodes (13/13), liver (12/13), spleen (8/13), kidneys (5/7), and bone marrow (5/7). A T cell phenotype (CD3epsilon+) characterized LGL neoplasia in 19/21 cases. A CD8alphaalpha+ cytotoxic/suppressor phenotype was present in 12/19 T cell tumors, 2 had a CD4+CD8alphaalpha phenotype, 3 had a CD4-CD8- phenotype, and 2 were CD4+ helper T cells. CD8beta chain expression was not detected in any instance. In two cats, a B or T cell origin could not be established. CD103 was expressed by 11 of 19 (58%) of the lymphomas tested. The immunophenotypic features shared by neoplastic LGLs in the cat and feline intestinal intraepithelial lymphocytes (IELs) support a small intestinal IEL origin for feline LGL lymphoma.     

The effects of florfenicol on lymphocyte subsets and humoral immune response in mice

Florfenicol is a broad-spectrum bacteriostatic antibiotic used in domestic animals. The aim of the study was to determine the effect of florfenicol on the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets (CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the peripheral lymphatic organs in non-immunized mice and humoral immune response in sheep red blood cells (SRBC)-immunized mice. Florfenicol was administered orally at a dose of 30 mg/kg six times at 24 h intervals to non-immunized mice and four or seven times at 24 h intervals to SRBC-immunized mice. SRBC was injected 2 hours prior to the first dose of the drug. Florfenicol increased the percentage of CD4CD8- thymocytes and the absolute number of CD4+ and CD8+ thymocytes on day 7. The increased percentage and absolute number of CD3+, CD4+ and CD8+ lymphocytes in mesenteric lymph nodes and decreased percentage of lymphocytes B were also observed 24 hours from the last administration of florfenicol. Florfenicol administered after SRBC immunization reduced the number of plaque forming cells (PFC) and the production of anti-SRBC antibodies on days 4 and 7 after priming.     

Cross-reactivity of human and bovine antibodies in striped dolphin paraffin wax-embedded tissues

This study evaluates the cross-reactivity of seven anti-human and one anti-bovine antibodies in formalin-fixed, paraffin-embedded tissue samples of liver and mesenteric lymph nodes of 13 striped dolphins (Stenella coeruleoalba). Four antibodies (CD3, IgG, lysozyme and S100 protein) reacted with striped dolphin lymph nodes in a similar pattern to that observed in the species of origin. The anti-human MHC class II mAb reacted strongly with macrophages and dendritic-like cells of striped dolphins, whereas a small number of lymphocytes were labelled with this antibody. These antibodies were used to study the immunophenotype of the inflammatory infiltrated in non-specific chronic reactive hepatitis (eight cases) and chronic parasite cholangitis (two cases) and normal liver (three cases) of striped dolphins. Non-specific chronic reactive hepatitis was composed of inflammatory infiltration of CD3+ T lymphocytes and IgG+ plasma cells in portal spaces and hepatic sinusoids. Lymphonodular aggregates observed in chronic parasitic cholangitis showed a cellular distribution similar to that found in lymph node cortex, including the presence of S100+ and MHC class II+ dendritic-like cells in lymphoid follicles and interfollicular areas. This result suggests that those inflammatory infiltrates are highly organised to enhance antigen presentation to B and T cells.