The immunopathology of unilateral vasectomy in the ram.

This study investigated the relationship between the local (spermatic granuloma) and systemic events after unilateral vasectomy in six rams. Spermatic microgranulomas were first observed at 4 weeks post vasectomy (PV), at which time lymphocytes, chiefly CD4+ (helper/inducer) cells, were incorporated into the periphery of the phagocytic wall. Although plasma cells accumulated around blood vessels near these early granulomas, they were not incorporated into them. All sectioned vas deferens contained additional microscopic spermatic granulomas away from the point of sectioning, as did one-third of cauda epididymides on the vasectomised side. There were significant (P < 0.001) increases in T-lymphocytes, especially CD4 cells and plasma cells (chiefly IgG-containing) within the granulomas at each successive PV interval. Concurrent enzyme-linked immunosorbent assay indicated initial presence of IgG and IgM antisperm antibody in serum between 2 and 4 weeks PV. There were significant increases of IgG (P < 0.01) and IgM (P < 0.001) throughout the experiment but IgA antisperm antibody was negligible.

The distribution of lymphocyte subpopulations in normal and acanthotic ovine skin.

The prevalence and distribution of lymphocyte subpopulations in normal and acanthotic ovine skin were investigated using monoclonal antibody immunocytochemistry. CD8+ cells were predominant in the epidermis of both normal and acanthotic skin, but were CD8+ cells, CD4+ cells and T19+ cells infrequent in normal epidermis. Within the dermis of normal skin, there were significantly greater numbers of CD4+ and T19+ cells situated around the superficial dermal vessels than in any other region examined. The majority of the CD8+ cells adjoined vessels, but the proportion that did not was greater for CD8+ than for CD4+ or T19+ cells. The CD4+ and CD8+ subsets were represented equally in adnexa. T cells were of memory phenotype. B cells and naive T cells, both of which express the CD45RA antigen, were rarely seen and tended to be associated with vessels in both normal and acanthotic skin. None of the T19+ cells (which are gamma delta+) resembled the dendritic gamma delta cells seen in murine epidermis. Acanthotic skin was strikingly different to normal skin. There was a greater abundance of T cells, particularly CD4+ cells, in acanthotic epidermis and the numbers of CD8+ and T19+ cells, and to a greater extent CD4+ cells, were greater at the dermal-epidermal junction. There were more CD4+ and CD8+ cells in the superficial dermal stroma of acanthotic skin. Within the dermis of acanthotic skin, T cells were concentrated near vessels but the apportioning of T cells between stromal/adnexal and vessel-associated sites differed from normal. Such observations suggest that migration away from perivascular sites and into the stroma may be controlled separately for subregions of skin and for each T cell subset. The role of this altered nonrandom migration of T cells in skin chronically exposed to ultra violet radiation is uncertain.

Major histocompatibility complex antigens in normal, acanthotic and neoplastic ovine skin: an association been tumor invasiveness and low level MHC class I expression.

The distribution and density of ovine MHC class I and class II antigens in normal, acanthotic and malignantly transformed ovine skin was investigated using monoclonal antibodies and an immunoperoxidase technique. The subjects were sheep that had been exposed to high levels of sunlight for more than 6 years. The expression of MHC class II antigens in the plasma membrane of cells within the normal epidermis was restricted to basally located dendritic and mononuclear cells. Normal keratinocytes did not express MHC class II antigens. However, we observed low levels of intracellular MHC class II expression in both acanthotic and neoplastic keratinocytes. Expression of MHC class I antigens was variable in normal and acanthotic epithelium; it was usually present, but of low intensity in very early ovine squamous cell carcinoma and was increased in small, but morphologically typical, tumors. Tumors originating on the nose, which are more invasive than those on the ear, were found to express significantly less MHC class I (P < 0.05). Thus, an association between tumor invasiveness and low level expression of MHC class I was apparent. This may have diagnostic value and highlights a mechanism by which neoplastic cells may evade immune surveillance by T cells.

Immunopathology of experimental Jembrana disease in Bali cattle.

Sequential immunohistochemical studies of the lymphoreticular responses of Bali cattle (Bos javanicus syn. Bos sondaicus) after inoculation with the Jembrana disease virus were carried out using the peroxidase-antiperoxidase test for immunoglobulin containing cell assessment and the indirect immunoperoxidase test for lymphocyte subset assessment. The prevalence of immunoglobulin G-containing cells declined during the acute phase of the disease but became significantly elevated during convalescence. This trend was consistent with serological responses previously observed using an enzyme linked immunosorbent assay. Temporary immunosuppression appeared to occur during the acute phase of the disease as indicated by a decrease in the immunoglobulin G-containing cells in the lymphoid organs and an observed decrease in the BoCD4/BoCD8 lymphocyte ratio in lymph node follicles.

Immunopathology of experimental Brucella abortus strain 19 infection of the genitalia of bulls.

Antibody responses in serum and semen, and immunoglobulin containing cell (ICC) populations in the genitalia of bulls were compared after inoculating Brucella abortus strain 19 into the seminal vesicles of two bulls (ISV route) and into testes in two other bulls (IT route). Bulls seroconverted as early as 1 week post-infection (PI). Peak serum titres as determined by the serum agglutination test (SAT), complement fixation test (CFT) and ELISA occurred at PI weeks 3, 4 and 5 respectively. Highest titres were in IT inoculated bulls. Seminal antibodies against B. arbotus S19 were demonstrated from 2 weeks PI by both the SAT and the Rose Bengal Test (RBT) and highest titres occurred at PI weeks 3 and 4. Examination of immunoglobulins (Ig) in semen, however, revealed no significant differences of Ig isotypes between infected and control animals at any examination time. When bulls were killed at 7 weeks PI, quantitation of ICC in genital sections stained by the peroxidase-anti-peroxidase method revealed an overwhelming predominance of IgG containing cells in inflamed organs. In all cases IgG1- and IgG2-containing cells were prevalent, and present in approximately equal numbers. IgA-containing cells were second in prevalence in inflamed tissues while IgM cells were always in low percentage. High prevalence of ICC in infected genitalia, associated with elevated specific seminal antibodies but not with increased seminal Ig indicates that most Ig remains localised in tissues and is not transferred into genital secretions.

The pathology of experimental Trypanosoma evansi infection in the Indonesian buffalo (Bubalus bubalis).

Six Indonesian buffaloes (Bubalus bubalis) were inoculated intravenously with 10(5) Trypanosoma evansi, examined clinically, haematologically and serologically, and then killed 1, 2, 3, 4, 8 or 12 weeks after infection for detailed pathological study. Relapsing fever was related to the waves of parasitaemia and fluctuations of pulse and respiration rates. Anaemic mucous membranes, depression, weakness, refusal to walk, loss of appetite and emaciation were seen. Body weight, packed cell volume, total platelet and red cell counts, and haemoglobin values were below those of two uninfected control buffaloes, as well as below the normal range; on the other hand antibody titres against T. evansi in infected animals were all above those in controls. Emaciation, serous atrophy of fat, hydropericardium, petechial to larger haemorrhages in the pericardium, pneumonia, congested liver and spleen, oedematous enlargement of the superficial lymph nodes and hyperplastic bone marrow were the major gross pathological changes. Histologically, the severity of the disease increased from 1 to 7 weeks after infection and became less obvious at 12 weeks. The most consistent lesions were interstitial pneumonia, interstitial myocarditis, splenic multifocal necrosis, interstitial myositis and hyperplastic bone marrow. The last three lesions appear not to have been reported previously in T. evansi infection in buffaloes or other animals. The clinicopathological findings in this study show that T. evansi is both an intravascular and extravascular parasite.

Non-effect of regional lymph node removal on growth of ovine aural squamous cell carcinoma.

The effect of ipsilateral parotid lymphadenectomy on growth of lesions of aural squamous cell carcinoma in 10 adult ewes was compared over a 6-month period, with matched, tumour-affected controls that were not subjected to parotid lymphadenectomy. There was no significant difference between groups, indicating that the regional lymph node had no influence on the growth of the tumour.

Studies on experimental Jembrana disease in Bali cattle. III. Pathology.

Experimental infection of Bali cattle (Bos sondaicus) with blood from a case of Jembrana disease caused a well-defined pathological response. The disease was generalized except for the central nervous system which did not show significant cellular reactive changes. Following a general lymphoreticular reaction in the first week (Phase 1), the predominant effect was an intense non-follicular proliferative response by reticulum (dendritic) cells and lymphoblastoid cells in lymphoid organs (Phase 2) and a similar infiltrative and proliferative process in liver, kidneys, adrenal medulla and elsewhere. In the kidneys, glomerular hypercellular swelling occurred which was associated with uraemia. Pulmonary alveolar cells reacted strongly to infection by swelling and proliferation especially in the anterior lobes. Mononuclear cell infiltration accompanied this response. In lymph nodes and spleen, a marked lymphoid follicular reaction and plasma cell formation developed from the fifth week of infection (Phase 3). The cytology and histological distribution of proliferative changes in the lymphoid system suggests that, during the acute phase of the disease, a predominantly T lymphocytic reaction takes place which may be associated with transient immunosuppression. Residual lesions occurred up to day 60 post-infection. In all affected tissues pleomorphic basophilic, intracytoplasmic inclusions occurred, especially from the second week until about the fifth week of infection, but persisted in small numbers for more than 2 months. By light microscopy both minute basophilic granular forms (Type 1) and large intravascuolar (Type 2) inclusions were consistently found in reticular cells, lymphoblasts, macrophages including Kupffer cells, pulmonary alveolar cells and occasionally in vascular endothelium. These structures appear to be of diagnostic value.

A study of immunoglobulin-containing and other cells in ovine aural squamous cell carcinoma.

The peroxidase-antiperoxidase method was used to quantify immunoglobulin (Ig)-containing cells at the host-tumour interface in ovine aural squamous cell carcinoma lesions at various stages of development. IgM-containing cells were never observed; only scattered, but strongly staining, IgA-containing cells were present. IgG-containing cells predominated; their prevalence increased from 0.17 +/- 0.34 cells per high power field (hpf; mean +/- standard deviation) in precursor lesions to a maximum of 13.6 +/- 2.6 cells per hpf in overt tumours which had not metastasized. Their prevalence in overt tumours which had metastasized was 4.6 +/- 3.9 cells per hpf. Quantitation of pyroninophils in sections stained by the methyl green-pyronin method showed a greater prevalence of plasma cells than IgG-containing cells, but a similar pattern of change was apparent. Mast cells were most prevalent in early stages, but no significant change in eosinophil numbers was observed.

A quantitative histological study of changes in the bovine testis and epididymis associated with age.

Quantitative histological studies were performed on the testis and epididymis of 80 normal bulls from beef herds in tropical Australia. Four age groups, ranging from nine months to over 10 years were established. Volumetric proportions of parenchymal and collagenous tissues, and tubular or duct surface to tissue volume ratios were determined at the dorsal, middle and ventral testicular regions and at the head, body and tail of the epididymis for each group. Detailed volumetric analyses of the relative volumes of particular parenchymal and stromal elements were made a the middle testicular region. Lymphoid and plasma cell populations were compared in all regions, including the efferent ducts. Differences in the distribution of testicular parenchyma and collagen were found; the dorsal region had more parenchyma and less collagen than the middle and ventral areas. Progressive intertubular fibrosis attributed to age was quantified; it was most marked ventrally. Reductions in the relative volumes of germinal cells, Sertoli cells, tubular cytoplasm and parenchyma, and in tubular surface to testis volume ratios with advancing age, indicated a decrease in the capacity per unit volume of testis to produce sperm. Increased immunocyte populations in the efferent duct region in young bulls were attributed to initial antigenic exposure. Increased antigenic exposure, in association with senile degenerative changes of the genitalia, might have caused the increased immunocyte populations seen in very old bulls.

Age associated morphological changes in the lymphoid system of tropical cattle.

Superficial (superficial cervical , subiliac) and deep (medial iliac) lymph nodes, tracheobronchial and mesenteric lymph nodes, Peyer's patches, thymus and spleen were collected from 165 apparently normal animals ranging from fetuses of six months gestational age to cows approximately 10 years old. Additionally, palatine tonsils were collected from 58 other animals of comparable ages. Weights of animals and most of the above organs were obtained and in 39 animals, representing seven age groups, quantitative histological studies were made on Peyer's patches or lymph nodes to ascertain any differences attributed to age or anatomical location of node. With the exception of thymus, weights of all lymphoid organs increased with age until puberty or maturity after which a levelling of organ weights was apparent. Organ weight-bodyweight ratios, however, were highest in fetuses or young animals after which they decreased (somewhat irregularly) with age. Few trends were observed relating histological findings to age. Depth of Peyer's patches and the follicular-non-follicular ratio (FNFR) in the cortices of superficial cervical plus subiliac nodes, however, increased rapidly (to approximately nine months and three years of age, respectively), reached a plateau, and then decreased. Pigment deposition in all nodes tended to increase with age. In regard to anatomical location, the medial iliac node (probably because of its deep location) tended to have the lowest corticomedullary ratio and FNFR, smallest germinal centre size and least pigment.

Immunocyte populations in the mammary gland of the rat at different stages of pregnancy and lactation.

Immunocyte populations of apparently normal rat mammary glands were examined at different stages of lactation using immunofluorescence techniques. IgA-and IgG-containing cells were present before parturition; IgA-containing cells were numerous than IgG- or IgM-containing cells during the entire period from pregnancy through parturition and lactation to involution.

Quantitative macroscopic and histological study of testicular hypoplasia in Bos indicus strain bulls.

Forty-six bulls between 17 and 23 months old were used in an investigation of testicular hypoplasia in Bos indicus strain bulls. Testes diagnosed as either unilaterally or bilaterally hypoplastic or normal were obtained at castration and were examined macroscopically and by quantitative histological methods. Estimations of sperm per gram of testis (spg) were made on these 46 bulls and two others. Testis weight was greatest in the 'normal of unilateral' group (106 g). The mean epididymis:testis weight ratio was 0.12 and did not differ significantly between groups. Increased basement membrane thickness, increased vacuolation and giant cells were not features of testicular hypoplasia per se. Seminiferous tubule diameter varied from 118 micrometer in bilaterally hypoplastic testes to 171 micrometer in normal testes. A mean tubule diameter of about 150 micrometer was considered useful for differentiating hypoplastic from normal testes in young post-puberal B indicus crossbred bulls. There was a significant correlation between tubular diameter and spg (r = 0.68, P less than 0.001) suggesting that tubular diameter measurements in histological sections could be used to predict sperm production. Although there was good agreement between clinical diagnosis and spg values, high spg values were found in several small testes which were considered hypoplastic on clinical examination. Examination of both unilaterally and bilaterally hypoplastic testes showed an interesting variation in the ratio of nucleus to cytoplasm in the interstitial cells. This was significantly (p less than 0.05) lower in the testes of normal bulls than in the other clinical groups.

A fatal case of salmonellosis in a dugong.

Salmonella lohbruegge was isolated from the kidney and the liver of a captive dugong calf (Dugong dugon) which died after an illness of at least several weeks. Clinical signs included diarrhoea and anorexia and were apparent for a week before death. Necropsy and histopathologic examination revealed thickening of the intestinal mucosa, epithelial degeneration, and epithelioid cell infiltration of mucosa, submucosa and contiguous smooth muscle. Enlargement of intestinal lymphoid tissue was apparent, and occasional focal granulomas were found in the liver. The source of the Salmonella infection was not ascertained.

Pathology of mucormycosis of cane toads in Australia.

The gross and microscopic pathology of a fungal septicaemia caused by the zygomycete. Mucor amphibiorum in 27 free-ranging cane toads, Bufo marinus, in Australia is described. Seven of the 27 toads had clinical signs of illness when discovered and five of these seven were moribund. Multiple granulomas were found in many organs, and in massive infections granulomas tended to coalesce. Liver, spleen, kidneys, urinary bladder, heart and lung were most commonly involved, but granulomas also occurred in subcutaneous lymph spaces, skin, gastro-intestinal tract, voluntary muscle, bone, cranial cavity and the oral cavity. Single lesions appeared grossly as a lemon coloured nodule < or = 5 mm in diameter. Histologically, the primary lesion was a granuloma composed of multinucleate giant cells, macrophages, occasional lymphocytes and eosinophils surrounding the distinctive sphaerules of M. amphibiorum. Fibroblasts occurred in greater numbers at the periphery and collagen formed a dense fibrous capsule around some nodules. A less common lesion resembled a microabscess and consisted of mononuclear cells, neutrophils and eosinophils surrounded by macrophages. Many of the centrally placed mixed inflammatory cells appeared necrotic. This reaction appeared to be more acute. Both types of lesions sometimes occurred concurrently, but the latter was less common. The pattern of lesions and natural history of M. amphibiorum suggested that ingestion of contaminated soil may have been the route of infection.

Metastatic phycomycosis in a horse.

Extensive subcutaneous phycomycosis of the lower hindlimb developed over a period of 8 months in a Thoroughbred filly. There was no response to treatments such as trichlorphon, sodium iodide, or etisazole. Extension of the limb lesion over the following 3 months was associated with an enlarged inguinal lymph node, which was removed. Characteristic phycomycotic lesions were observed in the node, and a fungus having the morphologic features of Hyphomyces destruens was isolated from both the limb and nodal lesions.

Congenital abnormalities of the genitalia of cattle, sheep, goats, and pigs.

The essential steps in embryology of the genitalia and its sexual differentiation, are briefly reviewed. The major intersex states in domestic ruminants and pigs are briefly considered. Major attention is directed to anomalies of the reproductive organs of mature female and male animals that are likely to compromise fertility. Emphasis is placed on clinical and pathologic findings and on occurrence and pathogenesis of recorded defects.

Diseases in young farmed crocodiles in Irian Jaya.

Thirty-eight young crocodiles that were emaciated and were euthanased or were found dead on 12 farms in Irian Jaya were examined post mortem. Major diseases were coccidiosis (nine crocodiles), pentastomiasis (four), visceral gout (two) and bacterial pneumonia and septicaemia (two). Other diseases and infections were steatitis, fungal pneumonia, gastric capillariasis, haemogregarine infection, ascariasis, filarioid infection and the presence of flukes in the intestine, kidney and blood. Multiple parasitism due to the collection of hatchlings in the wild was considered the primary cause of the ill-thrift and death of the crocodiles.

Diseases of young captive crocodiles in Papua New Guinea.

To identify causes of mortality in young captive crocodiles, detailed necropsy and laboratory examination was done on 54 (30 Crocodylus porosus, 22 C. novaeguineae, 2 of unrecorded species). Although multiple infections often confounded interpretation it was concluded that the major infectious diseases, of approximately equal importance, were coccidiosis, bacterial septicaemia with Gram-negative organisms, and metazoan parasitism including ascariasis and pentastomiasis. A range of other lesions and agents was recognised, including keratitis, enteritis of unknown aetiology, non-suppurative encephalitis, traumatic peritonitis and trematodes located in renal tubules, gut and blood vessels. Some crocodiles in poor condition had only mild lesions associated with metazoan parasites and the cause of death or illness could not be clearly determined, although it was considered likely that adaptation failure was a contributing factor.

Residues of endosulfan in the tissues of lactating goats.

The sites of tissue accumulation in lactating goats of the organochlorine insecticide endosulfan were studied. Twelve lactating goats were dosed orally with endosulfan (1 mg/kg body weight per day) for 28 days. Groups of 3 animals were killed on days 1, 8, 15, and 21 after endosulfan treatment ended and their tissues examined for the presence of endosulfan. Total residues of alpha and beta endosulfan and endosulfan sulphate (mg/kg) were detected in kidney (0.29), gastro-intestinal tract (0.20), liver (0.12), brain (0.06), muscle and spleen (0.04), lung and heart (0.01) and milk (0.02) on the first sampling day but within 15 days, concentrations had fallen to < 0.01 mg/kg in all tissues except kidney (0.20). Endosulfan could not be detected in animals 21 days after dosing had ceased. The residue in milk could only be detected on day 1 of sampling. This study indicates that kidney rather than fatty tissue should be used to monitor the presence of endosulfan in animals intended for human consumption.