J. M. Corpa

Differences in the immune responses in lambs and kids vaccinated against paratuberculosis, according to the age of vaccination

In order to evaluate and compare the peripheral immune responses induced by the vaccination against paratuberculosis in relation with the age of immunization, two groups of lambs and goat kids were vaccinated at 15 days and 5 months old, respectively. A heat-killed commercial vaccine was inoculated subcutaneously and humoral and cellular immune responses were measured by an ELISA and IFN-gamma assay, respectively, at 0, 30, 90, 180, 270 and 360 dpv in the lambs and 0, 30, 90 and 180 dpv in the caprine. IFN-gamma values did not show statistically significant differences between both groups, but when compared to the unvaccinated controls, this cytokine response tend to disappear earlier in animals vaccinated at 15 days old. The antibody response was always higher and more persistent in animals vaccinated at 5 months. The possibility of the incomplete degree of maturation of the immune system in 15 days old animals as the cause of the differences in the immune response to vaccination is suggested.

Mammary and Systemic Aspergillosis in Dairy Sheep

Mammary aspergillosis was diagnosed in four flocks of dairy sheep, comprising a total of 1,750 ewes. These animals had been treated prophylactically by intramammary infusion with cloxacillin 5 months prior to lambing. Mammary aspergillosis with concomitant spread to the regional lymph nodes was present in these flocks in a percentage ranging from 2% to 36.4% of treated sheep. Pathologic, bacteriologic, and mycologic studies were performed in seven of the affected ewes. Some of them also had lung, kidney, and liver involvement. The pathologic reaction within lesions ranged from the acute to subacute type, dominated by necrosis and vasculitis with thrombosis, to the chronic granulomatous type, with macrophages and giant cells. The distribution of lesions and the presence of a remarkable vasculitis with fungal thrombi in the mammary gland suggested a hematogenous dissemination of the infection from this organ. Immunologic staining with monoclonal antibody MAb-WF-AF-1, which reacts specifically with Aspergillus hyphae, identified the causative agent in histologic sections of the different affected tissues. The etiologic diagnosis was further supported by the isolation of Aspergillus fumigatus in pure culture from affected tissues and from eight samples of mammary secretions.

Control of paratuberculosis (Johne's disease) in goats by vaccination of adult animals

Correspondence to Dr Perez PARATUBERCULOSIS is a chronic wasting disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis. In Spain, the disease is present in all domestic ruminant species (Juste 1990). The infection in goats was first diagnosed in this country in 1979 (Garrido and Le6n 1979) and has been responsible for causing annual losses of greater than 10 per cent of a flock in several regions (Garcia Marin and others 1994). Conventional procedures to control paratuberculosis, based on the identification and culling of infected animals, have been very difficult in small ruminant species due to the lack of sensitivity of the majority of diagnostic tests for identifying infected animals (Kreeger 1991). However, vaccination has offered good results in controlling the disease in several countries (Sigurdsson 1960, Crowther and others 1976, Saxegaard and Fodstad 1985, Cranwell 1993, Perez and others 1995). Since paratuberculous infection is usually initiated very soon after birth, it has been recommended that vaccination should take place during the first few weeks of life (Larsen and others 1964, Saxegaard and Fodstad 1985). However, in ovine species, very good results have been achieved after vaccinating six-month-old sheep which are already likely to be infected (Sigurdsson 1960), or even adult animals (Crowther and others 1976, Perez and others 1995) in areas with a high prevalence of the disease. In all of these cases, a rapid and dramatic decrease in the presentation of new clinical cases was observed among the vaccinated animals. However, there are only a few reports dealing with vaccination of young goats, using either live (Saxegaard and Fodstad 1985, Marly and others 1988) or killed (Leslie and others 1988) vaccines. In all of the cases, a slow and progressive decrease in the prevalence of the infection and the number of clinical cases was observed over some years of follow-up. This study describes the results achieved after the vaccination of adult animals in a flock of goats with a high percentage of losses due to paratuberculosis, confirmed at least four years before the study. During the year before this study, the deaths of more than 15 per cent of animals in a flock of 189 adult, pure Guadarrama goats was recorded by a clinician, presumably due to paratuberculosis. The flock was managed in an extensive system and located in a dry and mountainous area of Madrid Community. Subsequently, paratuberculosis was diagnosed on the basis of clinical signs and by pathological methods in three culled goats, confirming the importance of the disease. A vaccination trial was established and approximately 50 per cent of the flock was vaccinated by the subcutaneous inoculation of 1 ml inactivated commercial vaccine (Gudair; cz Veterinaria) in the flank. In the remaining goats that were kept as non-vaccinated controls, 1 ml phosphatebuffered saline (PBS) was inoculated at the same site. During the following two years, a clinical follow-up was carried out and all the goats culled during this period, for any reason, were examined by pathological methods at the veterinary faculty of Leon. The animals were culled by an intravenous injecgm a S.S 7

Distribution of Lymphocyte Subsets in the Small Intestine Lymphoid Tissue of 1-Month-Old Lambs

Distribution of lymphocyte subpopulations along the small intestine lymphoid tissue has been examined in 1‐month‐old lambs using flow cytometric and immunohistochemical techniques. Monoclonal antibodies against CD4, CD8, γδ, CD45R and B receptors have been employed in samples from continuous ileal Peyer’s patch (IPP), discrete jejunal Peyer’s patches (JPP), ileocaecal valve lymphoid tissue (ICVPP), mesenteric lymph node (MLN) and intra‐epithelial (IEL) and lamina propria (LPL) lymphocytes. Histological studies were also done. Differences in the lymphocyte distribution have been observed between some of the regions examined, especially between IPP and JPP for most of the markers. A remarkable feature was the existence of morphological and lymphocyte distribution differences between ICVPP and IPP, locations that had been traditionally considered as similar. The antibody against CD45R receptor used in this study, that was supposed to mark B cells and some T cells, detected cell populations located in the dome of the follicles in all the samples, whereas the centre was negative. Lymphocytes positive to the B marker employed were located mainly in the centre, suggesting that both antibodies would mark B cells in different maturation status.

Effects of S-adenosylmethionine on hepatic regeneration after partial hepatectomy in the rat

Effects of S-adenosylmethionine (SAME) on hepatic regeneration has been evaluated in hepatectomized rats. Reduced (GSH) or oxidized (GSSH) glutathione were determined and liver examined by histological methods. Liver weight, after hepatectomy, increased in SAME treated group that showed a decrease in the number of mitotic figures, suggesting some protective effect.. No changes in GSH were observed, possibly due to the short period of time elapse (48h) between the experimental procedures and GSH determination.

Adenocarcinoma of the small intestine in a goat

A case of intestinal adenocarcinoma is described in a 4-year-old dairy goat with progressive emaciation. At necropsy, a tumour was found in the middle part of the jejunum as an annular, firm white mass which resulted in stenosis and dilation of the intestine proximal to the lesion. Spread of the tumour, with thickening of the contiguous mesentery, and metastasis to the mesenteric lymph nodes were observed. Microscopically, the tumour was characterized by nests or sheets of mucin-rich cuboid or columnar epithelial cells, which formed irregular acinar structures that infiltrated all layers of the intestinal wall. In the mesentery, neoplastic cells were surrounded by an intense fibrous reaction. A diffuse inflammatory infiltrate of lymphocytes was observed both in the mesentery and in the intestinal layers. These findings are compared with those observed in sheep, in which this type of tumour occurs more frequently.

Intestinal adenocarcinoma in sheep in Spain.

White blood cells (/pl) Neutrophils (%/pl) Banded neutrophils (%/p1) Lymphocytes (%/pl) Monocytes (%/lJp) Eosinophils (%/pl) Basophils (0/p/) Red blood corpusdes (/pl) Haemoglobin (g/dl) Haematocrit (s) Mean corpuscular volume (fl) Mean corpuscular haemoglobin (pg) Mean corpuscular haemoglobin concentration (g/dl) Red cell distribution width (%) Platelets (/pl) Phosphate (mmol/litre) Iron (pmol/litre) Total protein (g/litre) Albumin (g/litre) Glucose (mmol/litre) Blood urea nitrogen (mmol/litre) Creatine (pmol/litre) Total bilirubin (mg/dl) Direct bilirubin (mg/dl) Aspartate aminotransferase (U/litre) Alanine aminotransferase (U/litre) Alkaline phosphatase (U/litre) Creatine kinase (U/litre) Cholesterol (mmolAitre) Gamma glutamyl transferase (U/litre) Uric acid concentration (mg/do Triglycerides (mmol/litre) Albumin:globulin ratio Lactic acid dehydrogenase (U/litre) 9440 50 0 24 25 1 0 5,790,000 19.5 56.5 97.5 33.7 34-6 17*7 31,300 4.83 4.9 58 33 0-6 20 69 2 0.5 801 67 251 1198 1.5 72 0-7 2-8 1:3 3895