Porcine circovirus induces B lymphocyte depletion in pigs with wasting disease syndrome

To disclose the mechanism of cellular injury following porcine circovirus (PCV) infection, 12 pigs were examined by the terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) method and immunohistochemistry. Histologically, the lymphoid tissues were characterized by marked apoptosis of lymphocytes, lymphocyte depletion, and macrophages and giant cells containing numerous inclusion bodies with or without apoptotic bodies. Immunohistochemically, there were many lysozyme-positive macrophages in the lymphoid follicles, while the number of CD79a-positive B lymphocytes was scanty. Apoptotic cells, which were proved to be TUNEL positive, revealed CD79a positivity. Although detectable mainly in the cytoplasm of macrophages, PCV antigens were found also in the nuclei of macrophages and apoptotic lymphocytes. Ultrastructurally, the presence of PCV virions was confirmed in apoptotic bodies phagocytosed by macrophages. These findings suggested that lymphocyte depletion with apoptotic death of B lymphocytes was caused by PCV, and that some of the inclusion bodies were phagolysosomes derived from the apoptosis. Thus, PCV may trigger the development of wasting disease syndrome by producing an immunocompromised state in pigs.

Intestinal spirochetosis in wild sika deer (Cervus nippon yesoensis) infected with Brachyspira species

Seven adult free-ranging sika deer (Cervus nippon yesoensis) were examined by histology, immunohistochemistry and electron microscopy for intestinal spirochetal infection. Histologically epithelial and goblet cell hyperplasia and edema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the cecum and colon in 6 of the 7 deer. Numerous argyrophilic spirochetes were present in the crypts and some had invaded epithelial and goblet cells and caused degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Brachyspira (Serpulina) hyodysenteriae and B. pilosicoli. Ultrastructurally they were 6-14 microm long, 0.2-0.3 microm wide and had 4-6 coils and 13 axial filaments per cell; such features were closely similar to those in the Brachyspira species. These results showed that the spirochetes were capable of inducing enteritis in deer and this intestinal spirochete infection might already be prevalent among wild sika deer in Japan. There is a possibility that this spirochetal colitis is a new syndrome in sika deer and that the same and/or similar spirochetes have infected ruminants, including sika deer and cattle.

Developmental changes in the protein and mRNA content of a p115/transcytosis-associated protein in the bovine mammary gland

We measured the amounts of a vesicular transport factor, p115/transcytosis-associated protein (p115/TAP) and its mRNA, in mammary glands from cows in which lactation was induced hormonally. The highest level of p115/TAP mRNA, determined by Northern blotting, was detected in the developing stage. In contrast to the mRNA level, the amount of protein, determined by immunoblot analysis using anti-p115/TAP antibodies raised against a p115/TAP-derived recombinant fusion protein, was higher during the lactating stages than at other times. Immunohistochemical study showed that p115/TAP was predominantly localized in mammary epithelial cells. The p115/TAP was also detected in tissues other than the mammary gland but, in contrast to the situation in the mammary gland, the protein and its mRNA levels in those tissues were independent of the stage of lactation. The increased level of p115/TAP mRNA during the developing stage and the maintenance of p115/TAP protein during lactation suggest that the synthesis of p115/TAP is regulated during mammary development and differentiation, and also that the protein is involved in a function related to lactation.

Myofibroblastic sarcoma of the pleura in a pig

An intrathoracic sarcoma from a 7-month-old female pig was studied by light and electron microscopy and immunohistochemistry. The tumor tissue of varied cell density consisted chiefly of spindle-shaped cells, some of which grew around blood vessels in a concentric fashion. Many tumor cells were positive for alpha smooth muscle actin and not for desmin, though some cells were reactive for both antigens. A majority of tumor cells had ultrastructural features characteristic of myofibroblasts, but a few cells resembled vascular smooth muscle cells in the synthetic state. This neoplasm may have arisen from vascular smooth muscle with features indicating a transition to myofibroblasts.

Evidence of porcine circovirus infection in pigs with wasting disease syndrome from 1985 to 1999 in Hokkaido, Japan

An epizootiological survey with histopathological methods was conducted for porcine circovirus in 220 diseased pigs (1-200 days old) in 49 farms from 1985 to 1999. Histopathological lesions containing PCV antigen were detected mainly in the lymphoid tissues from 42 of 189 diseased pigs (22.2%) in 4 of 45 farms (8.9%) from 1990 to 1999. The rate of positive pigs gradually increased from 1997 onward and PCV infection was found in 50% of diseased pigs in 1999. Histopathologically, the lesions in the lymphoid tissues (including lymph nodes, Peyer's patches, tonsil and spleen) were highly correlated with the presence of numerous spherical basophilic intracytoplasmic inclusion bodies with PCV antigen, and consisted of lymphocellular depletion and infiltration of macrophages. Although most affected cells showed cytoplasmic reactivity for PCV, intranuclear antigen was also seen in the lymphocytes, macrophages and ileal epithelial cells. Ultrastructurally, macrophages and giant cells contained electron-dense, round to ovoid lysosomal bodies, in which there were concentric circle or paracrystalline arrays of small nonenveloped icosahedral viral particles, approximately 15-17 nm in diameter. Other consistent infectious agents were present in 90.5% of cases, and porcine reproductive and respiratory syndrome virus infection was in 52.4% of the cases with PCV. The histopathological findings suggested that PCV induced systemic immunosuppression in the infected pigs and made them more susceptible to infection of the organisms. Because of the presence of PCV antigens in the intestinal epithelium, feces may play a significant role in dissemination of PCV.

Myeloblastic leukemia with massive neoplastic infiltration of the skin and mediastinum in a cow

An acute myeloblastic leukemia was found in a 3.5-year-old Holstein cow. The neoplasm was characterized by massive tumor growths, and there were multiple tumor nodules in the dermis or subcutis and a large tumor mass in the mediastinum. This tumor showed negative reactivity for CD3, CD79a, major histocompatibility complex class II and myeloid/histiocyte antigen. Ultrastructural features such as dispersed cytoplasmic granules and poorly developed organelles were compatible with those of early promyelocytes.

Long-term follow-up study of patients with cavernous sinus aneurysm treated by proximal occlusion

Proximal occlusion of the internal carotid artery (ICA) is still the treatment of choice for a large cavernous sinus aneurysm. Endovascular occlusion or trapping of the ICA with or without an extracranial-intracranial bypass is sometimes performed. We analyzed the results of the long-term follow up of 11 patients with a giant or large cavernous sinus aneurysm treated by only proximal occlusion between 1975 and 1989. Proximal occlusion of the carotid artery was performed by Selverstone clamping. The follow-up period ranged from 6 to 21 years (mean 13.9 years). Eight of the 11 patients showed improvement of cranial nerves paresis or headache, and four became asymptomatic. None of the original aneurysms ruptured. The final outcomes were nine good recovery, one moderately disabled, and one severely disabled by the Glasgow Outcome Scale. The causes of morbidity were early ischemia and subarachnoid hemorrhage from a newly formed aneurysm. Late complications included ischemia in two patients, and new formation and enlargement of aneurysms at a site other than the original aneurysm in two patients, 13 and 17 years later. Therapeutic carotid artery occlusion requires strict test ICA occlusion. In addition, long-term follow up by periodical cerebral angiography using magnetic resonance, computed tomography, or digital subtraction angiography is necessary, and postoperative medical treatment is important to reduce the risk of late complications.

Melanotic neurofibroma in a steer

A melanotic neurofibroma in a steer was investigated histologically, immunohistochemically and ultrastructurally. A very large tumor mass was located in the region of the head and right cheek. The tumor tissue consisted of an admixture of cells resembling Schwann cells and spindle-shaped cells, and they frequently contained melanin granules. Neoplastic Schwann cells were positive for S100 protein, with variation in intensity of staining, but most spindled cells were S100 negative. The tumor cells displayed ultrastructural features similar to those of Schwann cells or perineurial cells. The presence of melanosomes in varying stages of melanization in both cell types suggests that they have a common origin. This is a tumor of neural crest origin showing schwannian and perineurial differentiation, with ectopic production of melanin granules.

Myofibroblastoma of the neck in a heifer

A 1.5-year-old Holstein heifer had a subcutaneous tumor mass (20 cm diameter) on the ventral portion of the neck, and the tumor was diagnosed as a locally invasive myofibroblastoma. It consisted of moderately cellular fibrous tissue, and the interlobular septum of the thymus was invaded by tumor cells. The neoplastic cells were positive for alpha smooth muscle actin and vimentin, but not for desmin. Electron microscopy disclosed the presence of moderately developed rough endoplasmic reticulum and microfilaments with focal densities.

Anaplastic gangliocytoma with eosinophilic cytoplasmic granules in a cow

In a 3-year-old Holstein cow, a tumor mass replaced the left olfactory bulb. The tumor was highly or moderately cellular, and consisted of tumor cells showing pleomorphism and anaplasia, sometimes with intracytoplasmic granules. The tumor showed weak reactivity for neurofilaments (NF) in most cells with distinct staining in a minority, and it was extremely rare to see neoplastic cells with positivity for glial fibrillary acidic protein (GFAP). The neoplastic cells displayed some ultrastructural features reminiscent of ganglionic cells, and the cytoplasmic granularity was due to the presence of numerous lysosomes. This tumor expressing both NF and GFAP may be histogenetically related to brain tumors of pluripotential cell origin in calves.

Thymic carcinoma with neuroendocrine differentiation in a calf

A neuroendocrine carcinoma originating in the thymus was found in a 7-month-old, castrated male, Japanese Black calf. The neoplasm consisted largely of very primitive cells, characterized by the paucity of cytoplasmic organelles, but a few cells were immunoreactive for somatostatin or neurofilaments. The expression of both cytokeratin and neurofilament protein was a feature of neuroendocrine differentiation. This neoplasm considered to be a tumor of a thymic stem cell, with little but indubitable evidence of differentiation into somatostatin-producing cells.

Differentiated embryonal rhabdomyosarcoma in a cow

An embryonal rhabdomyosarcoma was found in the pleura of a 2-year-old Holstein cow after first delivery. The most predominant cells in the tumor were relatively small in size, but considerable numbers of more differentiated cells of larger sizes mingled with the small cells. The most differentiated cells were characterized by multinucleation, abundant cytoplasm containing cross-striated fibrils, intense immunoreactivity for desmin, and weak or negative reactivity for vimentin. Such cells, lacking mitotic activity and displaying weak or no reactivity for proliferating cell nuclear antigen, were considered to be malignant counterparts of myotubes or muscle fibers. This neoplasm seems to follow normal skeletal muscle embryogenesis, and to be capable of differentiation into the final stage of muscle development.

Thymic carcinoma of the thymic hormone secretory type in a cow

An 8-year-old Holstein cow had tumor nodules and enlarged lymph nodes in the mediastinum, and metastatic tumor masses in the pelvic cavity. The neoplastic cells were characterized by squamous features and intracytoplasmic vacuoles carrying microvilli, some of which contained periodic acid Schiff-positive globular cores, but tubular structures or goblet cells were absent. Many neoplastic cells stained positively for keratin, and occasional cells were positive for thymosin. The presence of secretory granules in the cytoplasm was confirmed by electron microscopy. This neoplasm was considered to be of thymic hormone-secreting epithelial cell origin.

Pancreatic endocrine carcinoma with multiple hormone production in a raccoon (Procyon lotor)

A pancreatic endocrine carcinoma with lung metastases was found in a 15-year-old male raccoon. This tumour was characterized by great variation in cell size and production of multiple polypeptide hormones. Endocrine markers expressed by the neoplastic cells were, in descending order of frequency, chromogranin A, pancreatic polypeptide (PP), glucagon, somatostatin and insulin. Co-expression of PP and glucagon, somatostatin or insulin was demonstrated immunohistochemically with consecutive sections, and cells with both glucagon and insulin were also observed. The pattern of co-expression was similar to that in the earliest stages of murine pancreatic development. Amyloid deposits in the islets of Langerhans, which reacted with antibody to islet amyloid polypeptide, were thought to be associated with age.

Heading injury precipitating subdural hematoma associated with arachnoid cysts--two case reports

A 14-year-old boy and a 11-year-old boy presented with subdural hematomas as complications of preexisting arachnoid cysts in the middle cranial fossa, manifesting as symptoms of raised intracranial pressure. Both had a history of heading the ball in a soccer game about 7 weeks and 2 days before the symptom occurred. There was no other head trauma, so these cases could be described as "heading injury." Arachnoid cysts in the middle cranial fossa are often associated with subdural hematomas. We emphasize that mild trauma such as heading of the ball in a soccer game may cause subdural hematomas in patients with arachnoid cysts.

T-cell lymphoma in a savanna monkey (Cercopithecus aethiops) probably related to simian T-cell leukemia virus infection

Lymphoma was seen in an 11-year-old female savanna monkey (Ceropithecus aethiops). The superficial inguinal and visceral lymph nodes were markedly enlarged, and their architecture was completely effaced by neoplastic cells. The neoplastic cells, which were highly pleomorphic, resembled those in adult T-cell lymphoma-leukemia in humans. Ultrastructurally the neoplastic cells were characterized by nuclear irregularity and clustered dense bodies, and almost all cells showed positivity for CD3. The animal had been reared with her family, and her mother and 2 brothers had antibodies reactive to human T-cell leukemia virus. This virus serologically cross-reacts with simian T-cell leukemia virus, which may be the causative agent of the present neoplasm.

Adenocarcinoma of the lung in a Steller sea lion (Eumetopias jubatus)

The histological and ultrastructural characteristics of an adenocarcinoma of the lung are described in an about 16-year-old female Steller sea lion with a 1.5 month history of cough and anorexia. The animal had multiple neoplastic nodules in the lungs and diaphragmatic pleura. The bronchial and mediastinal lymph nodes were replaced by neoplastic tissue, and there were several metastatic lesions in the liver and spleen. The lung tumor was characterized by accumulations of encapsulated lesions with central necrosis, and the neoplastic cells showing a papillary growth pattern produced small amounts of mucin. Ultrastructurally, some cells contained basal bodies, and cilia were rarely seen. This neoplasm was considered to be of ciliated bronchial or bronchiolar epithelium origin.

Haemangiopericytoma in a calf

After castration, a Japanese Black male calf developed subcutaneous tumours near the scrotum. They were surgically excised, and no recurrence was detected two years after surgery. The tumours were characterised by neoplastic cells concentrically arranged around blood vessels of various sizes. The neoplastic cells contained many cytofilaments, and the majority of the cells expressed smooth muscle actin, but focal densities were not found. On the basis of the immunohistochemical and ultrastructural features, the tumours were considered to be of pericyte origin.

Myeloproliferative disease in a calf

A myeloproliferative disease was found in a 128-day-old Holstein female calf. The tumour consisted chiefly of primitive cells, and more mature cells, many of which were positive for haemoglobin, were admixed with them. Binucleated cells at various stages of maturation were occasionally seen, and siderosomes were confirmed in both primitive cells and more mature cells by electron microscopy. The primitive cells resembled proerythroblasts, and this tumour, thought to be an acute type neoplasm of the erythroid system, was distinguishable from chronic erythremic myelosis and polycythemia vera.

Characterization of [3H]5-hydroxytryptamine and [3H]spiperone binding sites in clathrin-coated vesicles from bovine brain

Coated vesicles prepared from bovine brain cerebral cortex exhibited [3H]5-hydroxytryptamine (5-HT, serotonin) and [3H]spiperone binding activities. The binding activities were localized in the inner core vesicles. Binding reached an equilibrium level by 30-45 min at 30 degreesC, and was reversed by the addition of 100 microM 5-HT for [3H]5-HT binding or 10 microM ketanserin for [3H]spiperone binding. The saturation binding experiments indicated a single class of binding sites for [3H]5-HT and [3H]spiperone with apparent Kd values of 2.4 and 1.75 nM, respectively. The binding of [3H]5-HT was displaced by 5-HT and 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), but not by ketanserin. The binding of [3H]spiperone was displaced by spiperone and ketanserin but not by 5-HT or 8-OH-DPAT even at 1 mM. The coated vesicles were shown by immunoblotting assay to contain alpha-subunits of GTP-binding proteins, Galphas, Galphai2, Galphai3, Galphao and Galphaq/11. Forskolin-stimulated adenylate cyclase activity in the coated vesicles was inhibited to 80% of the control level by 5-HT or 8-OH-DPAT. These results suggested that 5-HT1A and 5-HT2A receptors are present in bovine brain coated vesicles and that the 5-HT1A receptors are coupled to adenylate cyclase activity via GTP binding proteins.

New guiding catheter for transrad PTCA

A new guiding catheter for PTCA is described. In our department, 302 patients (405 lesions) underwent transradial coronary angioplasty using the 6 Fr Kimny guiding catheter since January 1996. The total engagement rate using the Kimny guiding catheter was 91.3% (370/405). The engagement rate after the modified Kimny guiding catheter was introduced in May 1996 increased to 96.0% (243/253). The stent delivery success rate was 98.4%. We had two dislodged stents. PTCA for both left and right coronary arteries in a single procedure with the Kimny guiding catheter was performed via the radial artery in 27 patients. In 24 of these patients (89%) we engaged both coronaries successfully. In the remaining 3 patients we switched to another catheter. Except for 4 patients with non-Q-wave myocardial infarction, no major cardiac complications were encountered. No major entry site-related complications were seen, and no patient required vascular surgery or blood transfusions. In one patient the Kimny guiding catheter tip caused a minor dissection of the LMT, but no ischemic event occurred as a result. In conclusion, the Kimny device is a useful PTCA guiding catheter for routine angioplasty and stenting.