Serological response of cattle to Chlamydophila abortus in Slovakia in 1996-2000.

In the Slovak Republic, in 1966-2000, 37,275 blood sera of cattle were investigated for the presence of antibodies against Chlamydophila abortus using the method of complement fixation. The antibody occurrence had following tendency: in 1996--3.72%; 1997--10.02%; 1998--9.15%; 1999--15.99%; 2000--9.51% of the tested sera contained the antibodies. In most cases, antibodies in low titres, 1:32-1:64, were detected. Positive serological reactions at such serum dilutions are not indicative of the clinical disease of cattle; they reflect an immune response of the host organism following contact with the Chlamydophila abortus antigen. The chlamydial antibody titres of 1:256, which were confirmed in 1998-1999, indicate the chlamydial infections.

[Immunomodulatory effect of levamisole and administration of amitraz in dogs with uncomplicated generalized demodicosis]. / Imunomodulacný efekt levamizolu pri pouzití amitrazu u psov s nekomplikovanou generalizovanou demodikózou.

The immunomodulatory effect of levamisole (Decaris tbl.) in the course of acaricide therapy with amitraz (Taktic) on the functional activity of blood neutrophils (% of phagocytizing cells and ingestion capacity) and lymphocytes (blastogenic response to Con A) in dogs with uncomplicated generalized demodicosis (NGD) was studied. The level of examined parameters was evaluated before treatment, week 3 and 7 after the first application of these preparations; and compared with the values of NGD dogs treated only with amitraz and with those in clinically healthy dogs. In comparison with healthy dogs the initial level of examined activities of both cell populations was significantly depressed. A significantly earlier (4 weeks earlier) increase (when compared with values before treatment) of investigated activities of neutrophils and lymphocytes occurred in dogs treated with amitraz and levamisole in comparison with those in dogs treated only with amitraz. It was manifested especially significantly in phagocytosis, the ingestion capacity of neutrophils at this time of therapy has reached the level of those in healthy dogs. Functional activity of lymphocytes in both groups of NGD dogs has not reached a comparable value with that in healthy dogs either at the end of observation. The presented results indicate that significantly earlier improvement of functional activity of phagocytes and lymphocytes in demodectic dogs treated with amitraz and levamisole was connected with the immunorestorative effect of levamisole.

Lymphocyte blastogenesis to concanavalin A in dogs with localized demodicosis according to duration of clinical disease.

The aim of the study was to determine the degree of Con A induced lymphocyte blastogenesis in dogs with localized demodicosis (LD) within 1-3 and 6-8 weeks from appearance of the clinical signs. Ethidium bromide fluorescence assay was used for evaluation. In observation 9 clinically normal dogs, 6 dogs with LD a 4 dogs with generalized demodicosis (GD) were used. The results showed a statistically significant depression (P < 0.01) of blastogenesis in the LD dogs in comparison with that in the healthy dogs (Fig. 1). Responses to Con A were normal in dogs with LD in 1-3 weeks. However, a significantly depressed response to Con A (P < 0.025-0.001) was demonstrated in the LD dogs in 6-8 weeks (average 6.7 weeks) and it was comparable with that in the GD dogs with the duration of clinical disease on average for 8.7 weeks (Fig. 2; Tab. II). Thus, immunosuppression is not a necessary condition for dogs to develop spontaneous clinical LD and immunosuppression develops with the clinical signs of disease.

Evaluation of canine lymphocyte blastogenesis prior and after in vitro suppression by dog demodicosis serum using ethidium bromide fluorescence assay.

The mitogen induced blastogenic response of lymphocytes from normal dogs and dogs with generalized demodicosis (GD) was measured by the ethidium bromide (EB) fluorescence assay. Serum from GD dogs significantly suppressed the in vitro reactivity to Con A of peripheral blood lymphocytes (PBL) from normal dogs and GD dogs, however with a different percentage of suppression 40.6 and 81.2%, respectively. As a result, the degree of lymphocyte blastogenesis suppression in GD dogs did not parallel the immunosuppressive potency of their serum (Tab. IV). The data indicate that PBL obtained from GD dogs did not respond to Con A as well in the presence of serum from normal dogs as did PBL from normal dogs (Tab. IV). In one third of examined GD dogs a similar situation was described also by Hirsh et al. (1975). The basis for this cellular modified response is unknown. It does not appear that the age or the chronicity of the disease are related to this observation. Further studies are necessary to elucidate this relation. The GD dogs showed not only a significant depression of the lymphocyte response to Con A but also enhancement of the ability of unstimulated cells to proliferate was also observed (Tab. IV). Similar observation was reported by others (Barriga et al., 1992). The meaning of this is not clear at present. This finding is discussed in the light of proposed different effects of the parasite or the host's reactivity to the parasite on different subsets of lymphocytes. No significant difference of PBL responsiveness to Con A between healthy dogs with respect to the age (Tab. III) and the time of examination (compare results in Tabs. I and IV) was observed. Autologous serum showed a better responsiveness of normal canine lymphocytes to Con A than fetal calf serum (FCS). It is suggested that the use of FCS might lead to an erroneous judgement (Tab. I). Both lectins, Con A and PHA induced cell proliferation of healthy dogs in very similar amount (Tab. II). Our results indicated that EB fluorescence assay is a useful method for detection a respondence of canine lymphocyte blastogenesis.

Tissue macrophages of calves after high doses of glucan.

Relatively high doses of the soluble form of fungal glucan (50 mg/kg of body weight) were administered to two clinically healthy calves. Hepatosplenomegaly was not observed. Quantitative and significant qualitative changes were seen in macrophages in the medulla of lymph nodes as compared to the control animals. Both the fibrillar and the granular components in the vacuoles of phagocytosing cells appeared to be positive in the periodic acid-Schiff reaction (PAS); an amorphous component was PAS negative. Quantitative changes occurred also in the expression of IgM molecules on the surface of B lymphocytes. The results indicate that glucan can be used in ruminants also in a single high dose.

Effect of vitamin E on some leucocytic parameters and functions in transported calves.

The objective of this investigation was to determine the effect of vitamin E administration on leucocyte parameters and some of their functions in transported calves. In the study 8 calves, aged approx. 10 days, divided into two groups, were used. 20 mg of tocopheryl-acetate per kg body weight were administered orally to each of the 4 experimental calves 24 hours before loading. The calves were transported by road for 3 hours. Blood samples collected before and after the transportation were examined for total and differential leucocyte counts, T-lymphocyte subpopulation, phagocytic activity, leucocyte migration, serum immunoglobulin levels, and for plasma vitamin E and cortisol levels. The animals showed a leucocytosis with neutrophilia and lymphopenia after transportation. The administration of vitamin E led to a decrease of cortisol level in 24 hours. There was no difference between groups in cortisol reaction due to transportation stress. Leucocyte migration has been less inhibited in the control group after unloading. A mild decline in phagocytic activity was observed 3 hours after transportation. Serum immunoglobulins were unaffected by both vitamin E administration and transportation. Vitamin E had no significant effect on leucocyte function and cortisol levels in present study.

[The effect of primary BHV-1 infection on the dynamics of T and B lymphocytes in the peripheral blood and levels of specific serum antibodies in calves treated with glucan]. / Efekt primárnej BHV-1 infekcie na dynamiku T a B lymfocytov periférnej krvi a hladinu specifických sérových protilátok u teliat osetrených glukánom.

In the present study we investigated the dynamics of circulating T and B lymphocytes and serum specific antibodies in calves experimentally infected with IBR virus (I group) and in calves administered glucan (seven days before infection) and the infected (GI group). The percentages of T and B lymphocytes in the peripheral blood were determined from analyses by rosette methods; the titer of serum anti-IBR antibodies was determined by virus-neutralizing test on cell cultures. The dynamics of the percentage of circulating T lymphocytes showed a similar decreasing trend in both groups, with significant values on days 3 to 5 after infection (AI). In comparison with the calves of I group, the outset of T cell reduction was found to be less pronounced (within the first two days after infection), with a statistically significant difference on day 2 AI (P < 0.05), Fig. 1. A decrease in the percentage of T lymphocytes was related to an increase in the percentage of circulating B lymphocytes, with maximum on days 3 and 4 AI (P < 0.05), Fig. 1. All the calves before experiment beginning were free of serum anti-BHV 1 antibodies. They started responding to the experimental infection with IBR virus by production of serum antibodies between week 1 and 2 AI. The dynamics of serum anti-IBR antibodies showed an identical course in both experimental groups, with the more pronounced outset (P > 0.05) of immunological response in the calves of GI group (Fig. 2).(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of indicators of cellular immunity in experimental infectious bovine rhinotracheitis virus infection in calves treated with glucan]. / Hodnotenie niektorých ukazovatel'ov bunecnej imunity po experimentálnej infekcii vírusom IBR u teliat osetrených glukánom.

Some parameters of cell-mediated immunity (phagocytic activity PA and phagocytic index PI, metabolic activity and migration-inhibitive factor MIF of blood leucocytes) were investigated in calves experimentally infected with IBR virus (group II) and in calves premedicated with glucan seven days before infection (group I). A significant increase in the percentage of phagocytizing cells was observed in both groups of animals on days 2-4 of the experiment (P < 0.01) in comparison with the values before infection. If the two groups of animals were confronted with each other, there was a significant difference in the percentage of phagocytizing cells on days 1 and 2 after infection (P < 0.05), with the higher average values in the calves which were only infected. An evaluation of PI showed a statistically significant difference only in the glucan-treated calves on day 7 after its administration (P < 0.05), i.e. on day zero of the experiment. The inhibition of leucocyte migration ability was found on day 1 after infection, and it persisted for four days, without any significant differences between the groups. An evaluation of the metabolic activity of leucocytes (INT-test) showed a decrease in the calves of both groups in comparison with the initial value, without any significant differences when the values were confronted with each other.

[Delayed hypersensitivity and the primary antibody reaction after administration of infectious bovine rhinotracheitis inactivated oil vaccine to calves premedicated with glucan]. / Uroven oneskorenej precitlivelosti a primárnej protilátkovej odpovede po aplikácii inaktivovanej olejovej IBR vakcíny u teliat premedikovaných glukánom.

The level of delayed skin hypersensitivity (DSH) to DNFB and of the primary immune reaction was evaluated in the calves immunized with an inactivated oil IBR vaccine (V group) and in the calves premedicated with glucan (seven days before vaccine administration) and subsequently immunized with the mentioned vaccine (GV group). The DSH test did not reveal an alteration of cellular immunological reactivity in the calves immunized with an inactivated oil IBR vaccine; after the vaccine administration there was no significant difference in the DSH level from the value before vaccine administration nor in comparison with the value of control calves (K group), Tab. I. But in the immunized calves which were glucan-premedicated (from Pleurotus ostreatus; 10 mg/kg l.w.) a significantly higher DSH level was determined not only in comparison with the initial value (P < 0.05) before glucan administration but also with the value of control calves (P < 0.05), Tab. I. The categorization of calves according to the DSH level also points to the immunomodulating effect of glucan in this sense (Fig. 1); while the value of skin test ranged from 3.6 to 6.5 mm in the highest percentage of the calves of V and K groups on the dates before and after administration of the mentioned preparations, a marked increase (on the date after administration) in the number of calves (from 22 to 67%) with the value of skin test higher than 6.5 mm was observed in the calves of GV group. The vaccine administration in itself (V group) did not induce the production of measurable amounts of serum IBR antibodies till day 14 after immunization.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of an insoluble fungal glucan on indicators of immunity in calves]. / Vplyv nerozpustného fungálneho glukánu na niektoré ukazovatele imunity teliat.

Immunomodulative effect of insoluble fungous glucan (IFG) was observed on nine accidentally chosen calves, which were in the age from 4.5-5.5 months. The following items were observed: T, B lymphocytes, white blood cell count, index and activity of phagocytosis, induction and determination of interferon from leukocytes. In the experimental group there was a decrease in B-rosseting cells observed. On the 28-th day and on the 42-th day of experiment duration a significant increase in B-rosseting cells in comparison with control group has been observed. Average values were significantly different on the levels P < 0.01 and P < 0.05. Percentages of T-rosseting cells were almost the same during the whole experiment. In the experimental group on the 7-th and on the 14-th day the decrease has been observed. By the Student's t-test a significant difference in favour of group, where IFG was applicated, has been observed. Percentage of white blood cell count was from 47 to 72 in both groups. When phagocytic activity was evaluated, there was the higher percentage of phagocytic cells in the 7th, 14-th, 21-st, 28-th and 42-th day of experiment when compared with the 0-day value. Concerning the phagocyte index a statistical difference was observed, when compared to the initial value in favour of the experimental group. The initial disbalanced values of interferon, which have been observed during the period from the 7-th to the 21-st day, increased on the 28-th and the 42-nd day of experiment which was statistically confirmed on the following levels: P < 0.05 and P < 0.01.

[The effect of administration of non-soluble fungal glucan on the level of delayed skin hypersensitivity and phagocytic activity of leukocytes in the blood of calves]. / Vplyv aplikácie nerozpustného fugálneho glukánu na úroven oneskorenej koznej precitlivelosti a fagocytárnu aktivitu krvných leukocytov u teliat.

The level of delayed skin hypersensitivity (DSH) was evaluated in vivo after dinitrofluorobenzene induction (3rd and 7th week of the experimental) while the level of phagocytic activity (FA) of blood leucocytes (in weekly intervals during six weeks of observation) was evaluated in calves (4.5 to 5.5 months of age) after administration of particular fungal glucane (from oyster mushroom) at a dose of 10 mg/kg live weight. In calves which were administered glucane (abbr. G), a significantly stronger cell-mediated immune response was recorded by means of DSH test in the 3rd week of observation, namely in comparison with its starting value (P < 0.01) and also with the value of control animals (P < 0.01; K group)-Tab. I. In the seventh week of the experiment there was not a statistical difference in the average values of DSH any more (Tab. I). But at that time 100 percent of calves showed a skin reaction above 6.5 mm (mean = 7.64 +/- 0.55) evoked by the used sensibilizer in the G group; this reaction was significantly higher (P < 0.01) in comparison with the value of DSH in a majority (80%) of calves of the K group (mean = 6.15 +/- 0.21)-Fig.1. The immunostimulating effect of the used glucane on the FA of blood leucocytes was less significant.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of Zindep on B-lymphocyte levels in pregnant cows]. / Vplyv prípravku Zindep na hladinu B-lymfocytov u gravidných kráv.

In the present study the immunomodulation effects of the Zindep preparation, based on elementary zinc and zinc oxide, were followed on the humoral response of gravid cows in the 8th and 9th months, a week after parturition and in calves immediately after parturition and on day 15 of their life. An increased level of B-lymphocytes was observed on days 2, 5, 8, 15, 30 and 50 of the experiment. The highest average values were recorded in the experimental group on days 8 and 15 of the experiment. The mentioned values were statistically significant (T-test) at the level 0.05 and 0.01. The average values of B-lymphocytes in cows after parturition reached 22.3% in the cows of the experimental group and 20.5% in the control group. No pronounced differences in the number of B-lymphocytes in the calves of both followed groups were recorded. The statistical evaluation of the values obtained in the cows after parturition as well as in the calves was not carried out due to a small number of samplings.

Immunogold silver staining method for light microscopic detection of peripheral blood lymphocyte surface antigens with monoclonal antibodies.

Labelling of peripheral blood Lymphocytes surface antigens was carried out using the method of colloidal gold, enhanced with silver staining. Instead of PBS the minimal essential medium (MEM) according the Eagle, pH 7.2, was used rinsing of isolated lymphocytes. Visibility of positive reactions on lymphocytes at application of both mentioned media was the same. Positive reaction at demonstration of p24 BLV on cells acquired the from of black cap while the IgG expression was observed in the from of diffuse dispersion of colloidal gold on cells. Differences between the application of individual media were observed in the shape of peripheral lymphocytes in smears. Utilization of Eagle's MEM resulted in more uniform shapes and optically smooth surfaces when viewed under a light microscope.