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8 páginas, 2 figuras, 3 tablas., Sarcoptic mange is caused by the mite Sarcoptes scabiei and has been described in several species of domestic and wild mammals. Macroscopic lesions are predominantly hyperkeratotic (type I hypersensitivity) in fox, chamois and deer, but alopecic (type IV hypersensitivity) in wolf and some fox populations. To begin to understand the immune processes underlying these species differences in lesions, we examined skin biopsies from wolves (Canis lupus), foxes (Vulpes vulpes), chamois (Rupicapra rupicapra) and red deer (Cervus elaphus) naturally infested with S. scabiei. Twenty skin samples from five animals per species were used. Sections were immuno-stained with primary antibodies against Iba1 to detect macrophages, lambda chain to detect plasma cells, CD3 to detect T lymphocytes and CD20 to detect B lymphocytes. Skin lesions contained significantly more inflammatory cells in the fox than in the wolf and chamois. Macrophages were the most abundant inflammatory cells in the lesions of all the species studied, suggesting a predominantly innate, non-specific immune response. Lesions from the wolf contained higher proportions of macrophages than the other species, which may reflect a more effective response, leading to alopecic lesions. In red deer, macrophages were significantly more abundant than plasma cells, T lymphocytes and B lymphocytes, which were similarly abundant. The fox proportion of plasma cells was significantly higher than those of T and B lymphocytes. In chamois, T lymphocytes were more abundant than B lymphocytes and plasma cells, although the differences were significant only in the case of macrophages. These results suggest that all the species examined mount a predominantly innate immune response against S. scabiei infestation, while fox and chamois may also mount substantial humoral and cellular immune responses, respectively, with apparently scarce effectiveness that lead to hyperkeratotic lesions., This work was partially supported by the Principado de Asturias, PCTI 2018–220 (GRUPIN: IDI2018-000237 and FEDER). Ms. Ileana Z. Martínez was supported by a Fundación Carolina PhD scholarship (2017 call).

7 páginas, 2 tablas, 3 figuras., Spanish goat encephalitis virus (SGEV) is a novel tick-borne flavivirus subtype, closely related to the flavivirus louping ill virus (LIV). SGEV caused a severe, acute and mortal neurological disease outbreak in northern Spain in a goat herd. In order to characterize the cell population in lesions and to determine the distribution of the inflammatory cells, central nervous system (CNS) samples of nine female Alpine goats challenged subcutaneously with SGEV over the right thorax behind the elbow were evaluated using immunohistochemistry (microglia-Iba1, T lymphocytes-CD3, B lymphocytes-CD20 and astrocytes-GFAP). The number of microglia (37.8 %) and T lymphocytes (21.5 %) was greater than the number of B lymphocytes (16.8 %). Goats were classified into clusters based on the severity of histological lesions in CNS (A-mild to moderate lesions and B-severe lesions). Microglia was significantly more abundant than T and B lymphocytes in cluster B (severe lesions). The total area occupied by glial foci revealed that medulla oblongata and spinal cord were the most affected tissues. Astrogliosis (GFAP+) was present in the majority of the CNS sections being near to the pial surface. The lesion predominance on the right side of the medulla oblongata, which could be associated to the site of challenge suggestive of neurotropic route was also statistically confirmed. Results suggest that the cellular immune response would be the most important response to the SGEV infection., This work was partially supported by a grant from Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), reference number E- RTA2013-00013-C04-04 (FEDER co-funded) and the Principado de Asturias, PCTI 2018–220 (GRUPIN: IDI2018-000237 and FEDER). Ms. Ileana Z. Martínez was supported by a Fundacion Carolina PhD scholarship (2017 call). We thank Dr. Kevin P. Dalton for critically reviewing this article.

Three recombinant outer membrane proteins (rOmps) from the Haemophilus parasuis Nagasaki strain (serovar 5 reference strain), rOmpP2, rOmpP5 and rOmpD15, which have previously shown protection against H. parasuis infection in mice, were cloned, expressed and evaluated as vaccine antigens in colostrum-deprived pigs. When these animals were immunized with these rOmps and were later challenged intratracheally with 108 CFUs of the Nagasaki strain, no protection was seen in terms of survival, clinical signs, pathological results and recovery of H. parasuis. We hypothesized that a possible explanation for this lack of protection could be the low number of epitopes accessible to the immune system as a consequence of their poor exposure on the bacterial surface so that the immune response would not be able to protect against experimental infection by H. parasuis when a fully susceptible animal model, such as pigs, was used.

10 páginas, 4 figuras, 2 tablas., Spanish goat encephalitis virus (SGEV), a novel subtype of tick-borne flavivirus closely related to louping ill virus, causes a neurological disease in experimentally infected goats and lambs. Here, the distribution of microglia, T and B lymphocytes, and astrocytes was determined in the encephalon and spinal cord of eight Assaf lambs subcutaneously infected with SGEV. Cells were identified based on immunohistochemical staining against Iba1 (microglia), CD3 (T lymphocytes), CD20 (B lymphocytes), and glial fibrillary acidic protein (astrocytes). In glial foci and perivascular cuffing areas, microglia were the most abundant cell type (45.4% of immunostained cells), followed by T lymphocytes (18.6%) and B lymphocytes (4.4%). Thalamus, hypothalamus, corpus callosum, and medulla oblongata contained the largest areas occupied by glial foci. Reactive astrogliosis occurred to a greater extent in the lumbosacral spinal cord than in other regions of the central nervous system. Lesions were more frequent on the side of the animal experimentally infected with the virus. Lesions were more severe in lambs than in goats, suggesting that lambs may be more susceptible to SGEV, which may be due to species differences or to interindividual differences in the immune response, rather than to differences in the relative proportions of immune cells. Larger studies that monitor natural or experimental infections may help clarify local immune responses to this flavivirus subtype in the central nervous system., This work was partially supported by a FEDER co-funded grant from the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (E-RTA2013-00013-C04-04), Ministerio de Ciencia, Innovación y Universidades (MCIU) and the Agencia Estatal de Investigación (AEI) reference project RTI2018-096010-B-C21 (FEDER co-funded) and by the Principado de Asturias, PCTI 2018–220 (GRUPIN: IDI2018-000237 and FEDER). Ms. Ileana Z. Martínez was supported by a Fundación Carolina PhD scholarship (2017 call).

This study aimed to characterize the type of immune response induced by an experimental vaccine based on a mutant Haemophilus parasuis transferrin binding protein (Tbp) B (Y167A) defective in its ability to bind porcine transferrin. Clinical and pathological signs, bacterial clearance, antibody response and the cytokine profile in alveolar macrophages and spleen after the vaccination and challenge of twenty-two colostrum-deprived pigs with 10(8) CFU of H. parasuis were analysed. Pigs vaccinated with Y167A were compared to those vaccinated with native TbpB (nTbpB), those treated with a commercial bacterin (CB) against Glasser's disease, those unvaccinated challenged (CH) and those unvaccinated unchallenged (UNCH) pigs. The rectal temperatures of Y167A pigs resembled those of UNCH pigs and were significantly lower than those of the nTbpB, CB and CH animals. A major reduction in pathological changes of the challenged pigs was observed in the Y167A group. H. parasuis was cleared from 88.9% of the samples from Y167A pigs versus 60.0% and 55.6% from those of the CB and nTbpB groups, respectively. The antibody response elicited by Y167A by ELISA was notably higher than that observed for nTbpB and CB pigs and was capable of preventing the expression and secretion of IL-8. The expression of IL-4 and IL-5, which were associated with the specific antibody levels, suggests that the main mechanism of protection conferred by Y167A vaccine is based on a strong T-helper 2 response.

Late thrombosis of coronary drug-eluting stents is an infrequent but serious complication of percutaneous transluminal coronary angioplasty. The best predictor of this event is the lack of endothelialization of stent struts. The objective of this study is to characterize and quantify the time course of endothelialization of different stents implanted in nonatherosclerotic swine coronary arteries. Thirty-three Carbofilm-coated stents were implanted percutaneously in 11 anesthetized domestic, crossbred pigs (weight 25 ± 3 kg, 2 months old). Each animal received 1 stainless steel stent (SS), 1 cobalt-chromium stent (CCS), and 1 tacrolimus-eluting stent (TES) in each coronary artery. Follow-up periods were 1 day (n = 9 stents), 3 days (n = 9 stents), and 7 days (n = 15 stents). Longitudinal sections of the stented vessels were examined using scanning electron microscopy. At 1 day, there was scarce, patchy endothelialization with areas of fibrin; the endothelialization rate was similar for all the stents (SS, 29% ± 23%; CCS, 29% ± 24%; TES, 31% ± 25%; P = .9). At 3 days, there were more endothelial cells but with immature features and giant cells over fibrin; the endothelialization was greater in SS and CCS than in TES (SS, 79% ± 14%; CCS, 81% ± 17%; TES, 46% ± 9%; P = .007). At 7 days, arteries showed better endothelialization with few giant cells; the endothelialization was greater in SS and CCS than in TES (SS, 95% ± 4%; CCS, 98% ± 4%; TES, 79% ± 9%; P = .01). In conclusion, the described model is useful for the analysis of endothelialization of coronary stents and facilitates measurement of its rate of formation and characterization of the involved cell types.

A tumour located in the pectoral region and the left front flipper was observed in a 29-year-old female California sea lion (Zalophus californianus) that died following signs of respiratory disease and inappetence. Metastases were present in the lung and adrenal gland. The histological pattern of the tumour was variable. In some areas the tumour consisted of pleomorphic fibroblast-like cells arranged in a storiform pattern, while in other areas it comprised oval or polygonal cells with round to oval nuclei and some bizarre cells arranged in an alveolar pattern. Occasionally, multinucleated giant cells were observed. Immunohistochemically, the neoplastic cells only expressed vimentin. On the basis of the microscopical and immunohistochemical features the tumour was diagnosed as an undifferentiated high-grade pleomorphic sarcoma. This type of neoplasm with disseminated involvement of other organs is rare in all species and has never been reported in California sea lions.

Haemophilus parasuis is the agent responsible for causing Glässer's disease, which is characterized by fibrinous polyserositis, polyarthritis, and meningitis in pigs. In this study, we have characterized native outer membrane proteins with affinity to porcine transferrin (NPAPT) from H. parasuis serovar 5, Nagasaki strain. This pool of proteins was used as antigen to developed two vaccine formulations: one was adjuvanted with a mineral oil (Montanide IMS 2215 VG PR), while the other was potentiated with a bacterial neuraminidase from Clostridium perfringens . The potential protective effect conferred by these two vaccines was compared to that afforded by two other vaccines, consisting of recombinant transferrin-binding protein (rTbp) A or B fragments from H. parasuis , Nagasaki strain, and by a commercially available inactivated vaccine. Five groups of colostrum-deprived piglets immunized with the vaccines described above, one group per each vaccine, and a group of nonvaccinated control animals were challenged intratracheally with a lethal dose (3 × 10 8 CFU) of H. parasuis , Nagasaki strain. The two vaccines containing rTbps yielded similar results with minimal protection against death, clinical signs, gross and microscopic lesions, and H. parasuis invasion. In contrast, the two vaccines composed of NPAPT antigen and commercial bacterin resulted in a strong protection against challenge (without deaths and clinical signs), mild histopathological changes, and no recovery of H. parasuis , thus suggesting their effectiveness in preventing Glässer's disease outbreaks caused by serovar 5.

Epidermal morphogenesis was studied in vivo following prenatal exposure to retinoic acid (RA). In pregnant mice, a single oral dose of RA on day 11.5 of gestation failed to induce histological changes in fetal epidermal development except in epidermal thickness. Epidermal thickness increased from 16.5 days post-coitum (dpc) onwards, and temporal and spatial epidermal modifications in keratins K5 and K14 related to proliferative activity of keratinocytes were observed. An RA effect on cell proliferation was supported by a statistically significant increase in the number of epidermal S-phase cells, containing BrdU-incorporated DNA in RA-exposed mice compared with nonexposed animals. The prolonged in utero action of RA on epidermal proliferative activity in fetuses and newborns suggests a long-term RA effect that may play a role on the development and evolution of diseases in adult skin.

Summary Clinicopathological and immunohistochemical findings of two uncommon canine lipid-rich mammary carcinomas are described. The predominant histological feature in both tumours was the presence of at least 80% of cells with intracytoplasmic vacuoles which stained positively with Sudan IV but not with alcian-blue periodic acid-schiff method. In both tumours, small groups of non-vacuolated cells were identified among the vacuolated cells. However, histological and immunohistochemical differences were also found between these tumours. Thus, one of them was composed of tumour cells with a large and single vacuole, which were arranged in lobular pattern, while the other neoplasm showed an intraductal growth of tumour cells with a fine vacuolated cytoplasm. Immunohistochemically, in the first tumour most vacuolated cells were positive for CK (cytokeratin)8-7, indicating a secretory epithelial immunophenotype while CK5 and CK8-7-expressing non-vacuolated cells were associated with luminal duct immunophenotype. However, in the second tumour the expression of CK14 in most of vacuolated cells and α-smooth muscle actin (α-SMA) in non-vacuolated cells, alone or in combination with CK5 suggested a myoepithelial immunophenotype for both cell types. These results suggest heterogeneity of the cell type and growth pattern for this type of canine tumour as has been described in women but not in dogs.

The distribution of cytokeratins (CKs) and vimentin in the normal genital tract of calves and cows at different stages of the oestrous cycle and in epithelial tumours of the tract was studied immunohistochemically. Few differences in CK and vimentin immunolabelling were detected in relation to age or stage of the oestrous cycle. Coexpression of CKs in simple epithelia and in basal cells of stratified epithelia was detected in the oviduct and endocervix; this coexpression was different from that previously described in women. The demonstration of CKs but not vimentin in the neoplastic cells of a serous superficial ovarian papilloma suggested an origin from the ovarian surface epithelium, while the coexpression of CKs and vimentin in serous papillary and mucinous cystadenomas pointed to a possible origin from the rete ovarii. Studies on three uterine adenocarcinomas and the ovarian metastases from two of these showed an endometrial-CK phenotype. The intermediate filament profile of normal endometrium, conserved in uterine adenocarcinomas and their ovarian metastases, may be useful in discriminating between ovarian metastases from endometrial carcinomas and those originating from primary carcinomas in other organs.

Summary The aim of this study was to investigate the cross-resistance between Fasciola hepatica and Schistosoma bovis in lambs assessing parasitologic, gross pathologic, histopathologic and immunohistochemical changes in liver and small intestine. Thirty Castellana breed lambs were divided into five comparable groups and exposed to F. hepatica/S. bovis (group F/S), S. bovis/F. hepatica (group S/F), S. bovis (group S) or F. hepatica (group F) and six unexposed lambs were used as non-infected controls (group C). Primary patent infection with F. hepatica induced a lower number of schistosome eggs and a higher number of lymphocytes in intestinal and liver schistosome egg-induced granulomas in group F/S than in the groups S/F and S, liver damage being mainly attributed to F. hepatica. S. bovis infection followed by challenge with F. hepatica particularly increased the severity of the most significant liver alterations (cholangiohepatitis by F. hepatica and mesoendophlebitis by S. bovis) and F. hepatica seemed not to have an influence on established S. bovis infection. In addition, immunohistochemical results suggested that the predominant local immune response in both double-infected groups was different, being mainly a cell-mediated immune response in group F/S and a mucosal response in group S/F.

Introduction and objectives Paclitaxel-eluting balloons have shown high antiproliferative efficacy in the treatment and prevention of restenosis. Nevertheless, not all available devices are equally effective, which makes it interesting to compare results in a preclinical model. Our objective was to assess the preclinical efficacy and safety of different devices. Methods We implanted 51 metallic stents (Architect®, iVascular) in 17 domestic swine (mean, 25 [3] kg), inserting 1 stent per major coronary artery. Stent postdilatation was performed with different control balloons (n = 10) or paclitaxel-eluting balloons: paclitaxel-eluting balloon 1 (iVascular) (n = 15); paclitaxel-eluting balloon 2 (iVascular) (n = 16) and In.Pact Falcon® (Medtronic) (n = 10). The restenosis rate (using angiography and histomorphometry) and vascular healing parameters (balloon-related vascular injury score, endothelialization rate, and fibrin and inflammation scores) were analyzed at 28 days. Results The distinct paclitaxel-eluting balloons showed a similar degree of stenosis at follow-up, which was significantly lower than that in the control group: diameter stenosis was 9% (12%) vs 34% (18%) by angiography (P

The aim of this work was to study a retrospective case series of acute degenerative myopathy, which caused high mortality in adult horses grazing in a specific region of Spain, in relation to a possible etiopathogenesis. Outbreaks of myopathy occurred in December of 1999, 2003, 2009, and 2011 after an abrupt fall in temperatures and the first snowfalls. Ten horses were necropsied, and an exhaustive gross and histopathological examination was performed using specific histochemical stainings to evaluate muscle and cardiac damage. Intense myodegeneration, affecting the postural and respiratory muscles and the muscles involved in swallowing, was the main finding. A further consistent finding was necrosis of Purkinje fibers in the myocardium. Serum concentration values of creatine kinase, selenium, and vitamin E, as well as blood concentration values of glutathione peroxidase activity, were determined in 10 horses clinically affected and in another 12 horses with no clinical signs. In the affected horses, creatine kinase was high and reached values over 10,000 U/L. Selenium values were deficient in the horses affected, ranging from 4.2 to 10.5 mu g/g (reference range: >50 mu g/L) in selenium-untreated horses, and also, selenium values in 11 horses with no clinical signs were below the reference range. Glutathione peroxidase activity was below the reference range in all the analyzed sera, and vitamin E values were also below the reference range in four horses. The severe selenium deficiency together with a sudden arrival of unfavorable weather conditions seemed to provoke the arising of this disease. The presence of Eupatorium cannabinum in this valley is discussed as a possible source of the phytotoxin associated with rhabdomyolysis., Ministerio de Educación: AP2007-02007

The morphological development of the fetal mouse testis exposed to alpha-zearalanol (zeranol) or diethylstilboestrol (DES) was evaluated as part of an examination of the effects of transplacental exposure to non-steroid oestrogens on susceptible tissues. On days 9 and 10 of gestation, pregnant NMRI mice were given subcutaneous injections of ethyl oleate alone (0.1 ml) or zeranol or DES (150 micrograms/kg body weight) in ethyl oleate. The mice were killed from days 12 to 18 of gestation and the male fetuses were examined. Microscopical examination of the gonads indicated that the onset of testicular differentiation was earlier in the oestrogen-treated fetuses than in controls. Abnormal differentiation of gonocytes and foci of hyperplasia of fetal Leydig cells were observed in the oestrogen-treated mice. Male fetuses from female mice treated with DES showed a delay in testicular descent and progressive decrease in reactivity for cytokeratin (CK) 8 in fetal Sertoli cells. These morphological findings suggest that prenatal exposure to zeranol or DES induces abnormal testicular differentiation in the mouse.

Background: Second-generation drug eluting stents (DES) have shown a high efficacy in terms of restenosis prevention, like first-generation DES, with reduced rates of stent thrombosis, especially late stent thrombosis. The suggested mechanism for this superiority is a better morphological and functional healing response. The objective of this study is to compare the efficacy and safety results of 2 different, first and second-generation, DES in a swine model of normal coronary arteries. Methods: In 9 domestic juvenile swine (25 3 kg), one stent per coronary artery was implanted with an intended stent-to-artery ratio 1.1. We used 9 bare metal stents (BMS), 9 permanent-polymer paclitaxel eluting stents (PES) and 9 biodegradable-polymer biolimus eluting stents (BES). Quantitative coronary angiography was performed after 28 days to assess the in-stent % stenosis and the endothelium-dependent vasomotor response of the distal vessel (Acetylcholine 10-6M). We performed morphometric analyses of the in-stent % area stenosis and the endothelialization rate (haematoxylin-eosin stain, extent of luminal surface coverage with endothelial cells) at 3 levels of each stent sample. The eNOS endothelialization index measures the proportion of the whole luminal surface covered by eNOS endothelial cells. Results: All the stents were implanted as per-protocol, with a final stent:artery ratio 1.17 0.15. No baseline differences were observed between groups. The Table shows the restenosis and the functional healing parameters analyzed in each group.

3 páginas, 2 figuras.-- et al., Although louping ill affects mainly sheep, a 2011 outbreak in northern Spain occurred among goats. Histopathologic lesions and molecular genetics identified a new strain of louping ill virus, 94% identical to the strain from Britain. Surveillance is needed to minimize risk to domestic and wildlife species and humans., This article was partially funded by a grant from the Spanish National Institute for Agriculture and Food Research and Technology (INIA) (RTA2011-00010-00-00). A.B. is a recipient of a ‘Contrato de Investigación para Doctores’ grant from INIA. N.M. received a fellowship for prospective research from the Swiss National Science Foundation.

Haemophilus parasuis is the etiological agent of Glasser's disease, which is characterized by fibrinous polyserositis, polyarthritis and meningitis in pigs. This study was focused on the characterization of the acute-phase response after immunization and infection of colostrum-deprived pigs with H. parasuis serovar 5, by measuring serum concentrations of three positive acute-phase proteins (APPs) (pig major acute-phase protein pig, MAP; haptoglobin, HPG; C-reactive protein, CRP) and one negative APP (apolipoprotein A-I, ApoA-I). Six experimental groups were established: a non-immunized but infected control group (CTL); two groups immunized with either a recombinant transferrin-binding protein (Tbp) A or TbpB fragment from H. parasuis Nagasaki strain (rTbpA and rTbpB, respectively); two groups immunized with native outer membrane proteins with affinity to porcine transferrin (NPAPT), one of them inoculated intramuscularly (NPAPTim) and the other intratracheally (NPAPTit), and the last group receiving a commercially available bacterin (PG). The greatest concentrations of the three positive APPs and the lowest concentration of the negative APP were detected in CTL group, as well as in those animals belonging to rTbpA or rTbpB groups that died in response to challenge. Significant differences (P

CD44 is an adhesion molecule implicated in the progression of human breast cancer. The purpose of this study was to describe CD44 antigen expression in canine mammary carcinomas and to evaluate its prognostic significance in relation to other clinico-pathological variables. A reduction in CD44 expression was significantly related to variables such as tumour size and adherence to underlying tissues but was not related to tumour location or to ulceration of the overlying skin. Complex (grade I) and anaplastic (grade III) carcinomas exhibited more intense expression of this antigen than did some tubulopapillary and most solid carcinomas (grade II). Although reduced CD44 expression was associated with infiltrative growth and vascular invasion in solid carcinomas, intense expression was also observed in anaplastic tumours. Although overall these findings suggest a role for this adhesion factor in canine mammary tumour development and progression, the complexity and apparently paradoxical nature of some of the findings currently limit the use of this immunohistochemical marker as a prognostic indicator.

We investigated in vivo the histological and immunohistochemical responses of mouse hair pelage follicle morphogenesis to prenatal exposure to a potentially nonteratogenic dose of all-trans-retinoic acid (RA), as a basis studying the preventive effect of RA on adult mouse skin carcinogenesis. In pregnant mice, a single oral dose of RA at 30 mg kg-1 body weight given on day 11.5 of gestation caused no RA-induced changes in the morphology or temporal expression patterns of keratins during pelage hair follicle morphogenesis. The only differential effect of RA was a statistically significant increase in the number of BrdU-positive nuclei in hair bulbs from RA exposed fetuses compared with nonexposed mice. The absence of adverse RA effects suggests that this experimental design may represent a valuable protocol for use in studies on the in vivo effects of this retinoid on different skin diseases.

It is known that topical all-trans-retinoic acid (RA) modulates growth and differentiation of skin and its cutaneous appendages. To examine whether a pre-natal exposure to a potentially non-teratogenic dosage of all-trans-RA had any effect on vibrissal follicle development, the histologic and immunohistochemical responses to RA during its morphogenesis in NMRI mouse were investigated. After a single oral dose of 30 mg/kg body weight of all-trans-RA on day 11.5 of gestation, no fetal malformations were detected and the histological features and the distribution of keratin (K) proteins in comparable stages of vibrissal development were similar for the untreated, vehicle-treated and RA-treated mice. The absence of teratogenic response and of adverse effects on the vibrissae under the experimental conditions indicates that this protocol may be useful for investigation of the effects of pre-natal exposure to RA on the post-natal development of experimental tumours in the mouse skin.

Actinobacillus seminis isolates were cultured from the semen (two isolates) and the left testis (one isolate) of two one-year-old rams in Leon, Spain. One animal showed lesions of chronic unilateral orchitis and epididymitis while the other appeared to suffer a subclinical infection and only a moderate number of pleomorphic rods and inflammatory cells were present in its semen. The isolates were biochemically similar to the A. seminis type strain NCTC 10851 and two other European A. seminis isolates, except that they produced acid from sorbitol; their identity was confirmed by arbitrarily primed polymerase chain reaction. The isolates were also tested against 30 antimicrobial agents, and only marbofloxacin was found active against all of them. As far as is known, this is the first report of A. seminis isolation from rams in southern Europe.

The purpose of this study was to advance our knowledge of the histogenesis of spontaneous mammary tumours in laboratory mice. Normal mammary tissue and 19 spontaneous mammary tumours from adult female mice Were examined using monoclonal and polyclonal antibodies differing in their recognition of various cytokeratin intermediate filament proteins ( CK s). All neoplasms were intraductal and were invasive carcinomas with a tubular, papillary, cystic or solid growth pattern. CK 8-positive reactions Were detected in the normal alveolar and ductal epithelia and CK 5- and CK 14-positive reactions were seen in myoepithelial cells of nonlactating mammary glands. Positive staining for CK 5 and CK 8 was detected in all tumours and CK 14 was expressed in those with a papillary pattern. Comparisons between non-lactating glands and tumours indicated that the neoplasms were well or moderately differentiated, there was no squamoid differentiation and that they arose from the alveoli and duct system, not the myoepithelial cells.

Non-motile, Gram-negative rods, isolated from the intestinal tract and kidney of several dead animals in a gerbil colony, were identified as Citrobacter rodentium (formerly included in C. freundii species) on the basis of 31 biochemical tests. The isolates were tested against 40 antimicrobial agents and were all susceptible to ticarcillin plus clavulanate, ceftazidime and most of the quinolones studied, but were all resistant to most of the penicillins and aminoglycosides tested, and to fosfomycin, metronidazole and tiamulin. This bacterial species has been primarily associated with transmissible murine colonic hyperplasia, and this appears to be the first report of an epidemic infection in a gerbil colony with a fatal outcome in most of the animals affected.

6 pages, 2 figures, 1 table.-- PMID: 9839209 [PubMed]., The pathological response of sheep to two dose levels (400 or 10,000 cercariae) of Schistosoma bovis was evaluated 24 weeks after infection. The results confirmed that a single low or high dose causes lesions in the liver and intestine, and that the lungs, lymph nodes, pancreas and abomasum are affected in sheep given a single high dose. In addition, the study showed that pathological changes (mainly a granulomatous inflammatory reaction) were induced not only by eggs but also by adult worms, and that their severity was in general related to the dose of S. bovis. Hoeppli reaction product, observed on the surface of adult schistosomes in some parasitic granulomas, showed no immunoreaction for IgG, IgA or IgM.

Summary A statistical and pathological study on uterine tumours during the examination of 1489 female bovines at slaughter was carried out. A 0.4% (n = 6) incidence of uterine neoplasms, being 50% adenocarcinomas and the other 50% leiomyomas, was diagnosed. With regard to age groups, tumours were more frequent in the 11–15-year-old group. Two animals affected by adenocarcinoma were not fertile and they had ovarian metastasis that, to the authors' knowledge, has been cited as extremely rare in cows. An ultrastructural study of these carcinomas and their metastasis was also made. Two leiomyomas were intramural and another one was pedunculated and subserous located. All leiomyomas showed the features of old tumours.