The aim was to investigate the haematological and blood biochemistry changes of adult rabbits after two intravenous administrations of low-doses of E. coli lipopolysacharide (LPS). Six clinically healthy rabbits were distributed through a cross over design to experimental groups: Group 1 (LPS) treated with two intravenous doses of 1 mu g/kg bw of E. coli LPS at 6 h intervals. Group 2 (Control) treated with an equivalent volume of saline solution (SS) at similar intervals. Rectal temperature (T degrees R), serum concentrations of interleukin-6 (IL-6), C-reactive protein (CRP), haemogram, and the activity of enzymes aspartate aminotransferase (AST) and gamma glutamil transferase (GGT) were measured before and after LPS or SS administration. The administration of LPS in rabbits induced significant increases in IL-6 and CRP concentrations. Leukopenia associated to significant decreases of monocytes, lymphocytes and platelet count, with no significant changes in neutrophil count, were observed at 4 and 8 h after LPS administration. There were significant increases in total leukocytes and neutrophils count at 12 and 24 h. No significant changes (P > 0.05) were observed in mean values of PCV, total proteins, albumin and in the activity of enzymes AST and GGT. The administration of low doses of E. coli LPS induces a fast increase in body temperature, haematological and biochemical shifts, which are milder and have a lower intensity and shorter than previous reports in rabbits treated with high doses of LPS. These changes seem to be consistent with an initial inflammatory response induced by a gram-negative infection.

The effect of training was evaluated by corporal temperature determination, heart rate, respiratory rate, globular volume, hemoglobine and plasmatic lactic acid in 10 Selle Francais horses between 3 and 4 years old selectionated for to participate in equestrian competition. Determinations were performed in basal conditions and each 30 days during three months submitting the animals at velocities of 240, 300 and 360 m/min, TI, T2 and T3 respectively during 4 minutes each one with a rest period of 4 minutes for doing physiological determinations and to obtain blood samples from the yujular vein. Average and standard deviation were obtained and a variance analysis was performed for to determinate if there are significative variations between each control and between months. The results obtained showed that the exercise produces significative variations (P The results showed that it is possible to evaluate the training in field conditions and lactic acid is the better test for evaluate the training.

SUMMARY An experimental inoculation of Actinobacillus pleuropneumoniae (App) was carried out with a field isolate and an ATCC serotype 5. Three groups of 15 pigs each were used. Group 1 (G1) was the control group inoculated with sterile media, Group 2 was inoculated with the serotype 5 ATCC, and Group 3 (G3) was inoculated with a field isolate (418/07). The results showed statistically significant differences (P ≤ 0.05) in the total leukocytes count between G1 v/s G2 and G1 v/s G3. The total macroscopic lung lesions scores were statistically different among the 3 groups (P ≤ 0.05). However, statistical difference was found only between G1 and G3 in the histopathological lung lesions (P ≤ 0.05). This work shows a clear difference in the hematological changes and the macroscopic and histopathological lesions between the serotype 5 ATCC and the field isolate. These facts suggest a higher virulence and pathogenicity of the national isolate. The serotypification of this App national isolate will be done in the near future.

In order to know the muscular metabolism of the Selle Francais equines the enzymes activities of aerobic and anaerobio ways were studied in biopsies taken at two depths from the Gluteus medius muscle of males and females in training and without training of different ages. The results show that the enzymes activities of CS and HM) increase with the tissue depth, with training and with the age of the animals (p KEY woRDS: Horses, muscle, enzymes. PALABRAS CLAVE: Equino, musculo, enzimas.

An experimental inoculation of Actinobacillus pleuropneumoniae (App) was carried out with a field isolate and an ATCC serotype 5. Three groups of 15 pigs each were used. Group 1 (G1) was the control group inoculated with sterile media, Group 2 was inoculated with the serotype 5 ATCC, and Group 3 (G3) was inoculated with a field isolate (418/07). The results showed statistically significant differences (P <= 0.05) in the total leukocytes count between G1 v/s G2 and G1 v/s G3. The total macroscopic lung lesions scores were statistically different among the 3 groups (P <= 0.05). However, statistical difference was found only between G1 and G3 in the histopathological lung lesions (P <= 0.05). This work shows a clear difference in the hematological changes and the macroscopic and histopathological lesions between the serotype 5 ATCC and the field isolate. These facts suggest a higher virulence and pathogenicity of the national isolate. The serotypification of this App national isolate will be done in the near future.

The objective of this study was to determine the infectiousness and transmission capacity of the Chilean isolate of the PRRS virus to swine susceptible via direct contact. Therefore, 30 pigs, divided into 6 groups of 5 animals each, were used, one of which (G1) was inoculated with the virus and maintained in isolation unit I for 35 days, during which period blood samples were taken at 0, 3, 7, 11, 15, 19, 23, 27, 31 and 35 days post infection (dpi) for haemogram and viral isolation. Another group (G6) was used as a control and maintained in isolation unit 3. The remaining groups (G2, G3, G4, G5) were exposed by direct contact to the animals of G1 between 3 to 7, 10 to 14, 17 to 21, and 24 to 28 dpi, respectively, and later were taken to isolation unit 2 for 7 days. These animals were sampled for the viral isolate and haemograms at 0, 5 and 12 days post contact (dpc). At slaughter of G1 and G6 (35 dpi) and the contact groups (12 dpc) samples were collected from nasal mucous, tonsils, submandibular lymph node, lung and spleen for histopathological and immunohistochemical (IHC) study and samples of the tonsils and lungs for viral isolation. Only the pigs of G1 had a transitory fever and neither respiratory symptoms nor alterations in the haematological parameters were registered in the pigs of all groups. At necropsy, lymphadenopathy was observed in all the groups. Histopathologically, all the pigs of G1 had interstitial pneumonia, although via IHC few immunostained cells were detected. In lymphatic tissues, hyperplasia and lymphatic necrosis were observed. In all the pigs, cells positive to IHC were detected, especially in G3 and G4. The virus was isolated from blood between 3 and 23 dpi in G1, and between 5 and 12 dpc in G2 and G3; however it was not isolated from the serum of G4 and G5. The virus was isolated from the tonsils of all the pigs of G1 and the contact groups, although it was not isolated from the lungs in G4. These results indicate that the inoculated pigs are capable of transmitting the disease to susceptible pigs, including in the absence of viremia during a period of 28 days.

Resumen es: El objetivo de este estudio fue determinar la capacidad de transmision e infeccion del aislado chileno del virus PRRS a cerdos susceptibles expuestos por...

The aims of this study were to characterize the haematological and bone marrow changes, gross and microscopic lesions of pigs experimentally inoculated with the Chilean isolate of porcine reproductive and respiratory syndrome virus.Twelve 3-week-old pigs were divided in 4 groups of 3, one of which corresponded to the negative control group sacrificed at 0 days post-inoculation (dpi), and the 3 remaining groups corresponded to the inoculated pigs sacrificed at 7, 14 and 21 dpi.For each sampling period blood was collected for complete haemograme and at the necropsy time gross lesions were registered and samples for both bone marrow smears and histopathology were taken.The results of this study revealed haematological alterations characterized by a significant reduction (P<0.05) in the haematocrit and a significant increase (P<0.05) in the total leukocyte count associated with an increase in the monocytes and baciliforms.The bone marrow did not show significant variations in the ratio of myeloid to erythroid cells (P>0.05).At the same time, the gross lesions were mild and mainly characterized by the presence of conjunctivitis, periocular edema and a slight increase in the size of the lymph nodes.Microscopic lesions were characterized by the presence of interstitial pneumonia, depletion and necrosis in lymphoid organs, rhinitis, hepatitis, myocarditis and non-purulent encephalitis.These findings suggest that the Chilean isolate of the vPRRS to a strain with a low virulence.

The aims of this study were to characterize the haematological and bone marrow changes, gross and microscopic lesions of pigs experimentally inoculated with the Chilean isolate of porcine reproductive and respiratory syndrome virus. Twelve 3-week-old pigs were divided in 4 groups of 3, one of which corresponded to the negative control group sacrificed at 0 days post-inoculation (dpi), and the 3 remaining groups corresponded to the inoculated pigs sacrificed at 7, 14 and 21 dpi. For each sampling period blood was collected for complete haemograme and at the necropsy time gross lesions were registered and samples for both bone marrow smears and histopathology were taken. The results of this study revealed haematological alterations characterized by a significant reduction (P<0.05) in the haematocrit and a significant increase (P<0.05) in the total leukocyte count associated with an increase in the monocytes and baciliforms. The bone marrow did not show significant variations in the ratio of myeloid to erythroid cells (P>0.05). At the same time, the gross lesions were mild and mainly characterized by the presence of conjunctivitis, periocular edema and a slight increase in the size of the lymph nodes. Microscopic lesions were characterized by the presence of interstitial pneumonia, depletion and necrosis in lymphoid organs, rhinitis, hepatitis, myocarditis and non-purulent encephalitis. These findings suggest that the Chilean isolate of the vPRRS to a strain with a low virulence.

Porcine Reproductive and Respiratory Syndrome (PRRS), is a viral disease of swine that has been known in the United States since the 1980's. The sickness was initially characterized by rapid propagation through pork farms, spreading through almost all the United States and later Canada and European countries. in Chile, PRRS was diagnosed at the end of 1999 and is currently part of an eradication program.To contribute to the diagnosis of the disease in our environment and to characterize the distribution of the viral antigen in the tissues of inoculated pigs, using an immunohistochemical (IHC) study was carried out utilizing 12 hybrid pigs originated from a PRSS free genetic pyramid. Nine were inoculated with the national isolate of the PRRS virus and three were used as controls. The inoculated pigs received an intranasal dosage of 7.0 ml of viremic serum from inoculated pigs with a cellular culture dose of 10(5.4) TCID50 in order to reactivate its pathogenicity; they were also inoculated intramuscularly with 0.7 ml of the same serum. The pigs of the control group were sacrificed at 0 dpi and the inoculated pigs at 7, 14 and 21 dpi, At necropsy time, tonsils, retropharyngeal and mediastinal lymphatic nodes, thymus, spleen, nasal turbinates, lung, heart and liver were dissected, fixed, dehydrated and paraffin embedded. Additionally, lung alveolar macrophages were collected via a bronchoalveolar lavage. All these samples were immunostained using the monoclonal antibody SDOW-17 and the ABC complex method.Viral antigen was detected in the macrophages of all the tissues studied from 7 to 21 dpi. The organs that showed greatest intensity of reaction were the lungs and spleen. The consistent finding of greater quantity viral antigen of in these organs, these tissues suggest constitute the best source of samples for diagnosing the disease whether by IHC or other methods that detect the viral antigen or its genome.

SUMMARY Porcine Reproductive and Respiratory Syndrome (PRRS), is a viral disease of swine that has been known in the United States since the 1980’s. The sickness was initially characterized by rapid propagation through pork farms, spreading through almost all the United States and later Canada and European countries. In Chile, PRRS was diagnosed at the end of 1999 and is currently part of an eradication program. To contribute to the diagnosis of the disease in our environment and to characterize the distribution of the viral antigen in the tissues of inoculated pigs, using an immunohistochemical (IHC) study was carried out utilizing 12 hybrid pigs originated from a PRSS free genetic pyramid. Nine were inoculated with the national isolate of the PRRS virus and three were used as controls. The inoculated pigs received an intranasal dosage of 7.0 ml of viremic serum from inoculated pigs with a cellular culture dose of 10 5.4 TCID 50 in order to reactivate its pathogenicity; they were also inoculated intramuscularly with 0.7 ml of the same serum. The pigs of the control group were sacrificed at 0 dpi and the inoculated pigs at 7, 14 and 21 dpi, At necropsy time, tonsils, retropharyngeal and mediastinal lymphatic nodes, thymus, spleen, nasal turbinates, lung, heart and liver were dissected, fixed, dehydrated and paraffin embedded. Additionally, lung alveolar macrophages were collected via a bronchoalveolar lavage. All these samples were immunostained using the monoclonal antibody SDOW-17 and the ABC complex method. Viral antigen was detected in the macrophages of all the tissues studied from 7 to 21 dpi. The organs that showed greatest intensity of reaction were the lungs and spleen. The consistent finding of greater quantity viral antigen of in these organs, these tissues suggest constitute the best source of samples for diagnosing the disease whether by IHC or other methods that detect the viral antigen or its genome.

Resumen en: Biopsies were taken at a depth of 4cm from the Gluteus medius muscle of 16 horses. The animals were 6 years old and had not been trained during 3 months ...

Biopsies were taken at a depth of 4cm from the Gluteus medius muscle of 16 horses. The animals were 6 years old and had not been trained during 3 months before the study. The samples were analized by mATPase miofibrillar technique to determine the fibrillar composition by NADH-TR technique to determine the oxidative capacity of the fibres and immunohistochemistry to determine the fibre type.The histochemical study revealed an average fibrillar composition of 14, 39, 30 and 17 % for fibres typed I. IIA, IIX oxidative and IIX no oxidative and the inmunohistochemistry study showed 16, 35, 29 y 20% for fibres type I, IIA, IIX and IIA-IIX.The statistical analyses showed a good relationship between the histochemical and inmunohistochemical method in the determination of fiber types,The immunohistochemical method allows a good identification of the fiber in adult horses.

Biopsies were taken at a depth of 3 and 6 cm from the Gluteus medius muscle of 7 mares and 3 castrated male horses. The animals were 4 years aid and submitted to a previous specific training program for jumping during 6 months. The samples were analysed by the mATPase miofibrillar technique to determine the fibrillar composition, and by the NADH-TR technique to determine the oxidative capacity of the fibres. In addition, the fibre metabolic activity was determined by enzyme activities of the citrate synthetase (CS), 3-OH-acil CoA dehydrogenase (HAD), lactic dehydrogenase (LDH) and creatinkinase (CK).The averages obtained far the fibrillar composition were 14, 28, 41 and 17% at 3 cm depth and 25, 30, 34 and 10% at 6 cm depth for oxidative type I, IIA, IIB and non oxidative IIB fibres, respectively. The fibrillar composition varied in relation to the depth of the biopsy. Type 1 and type II B fibre percentages showed significant differences between 3 and 6 cm. Type IIA fibres were similar in percentage at both depths whilst, oxidative and non oxidative fibres type IIB showed a statistically significant difference in percentage of fibrillar composition at both biopsy depths. The area of the muscle fibres at 3 cm depth was 2191; 3466 and 5578 mm(2) for fibres type I, IIA and IIB, respectively and the lesser diameters were 19; 24 and 30 for fibres type 1, IIA and IIB, respectively. The area of the fibres at 6 cm depth was 2433; 3929 y 5558 mm(2) and the lesser diameters were 20; 25 y 30 for fibres I, IIA and IIB, respectively.The activity of CS, HAD, LDH, and CK enzymes was 817, 243, 1.20 and 1.80 U/mg protein at 3 cm depth and 1479, 542, 1.58 and 3.30 at 6 cm depth. The activities of CS and HAD enzymes were significantly different between depths during the training period.These results show that the training produced changes in the fibrillar composition and metabolic capacity of the Gluteus medius in horses prepared for jumping competition.Significant differences were obtained in the fibrillar composition and enzymatic activities when comparing pre-training and post-training data.