Ultrastructural identification of small granule prolactin (PRL) cells in goat adenohypophysis by the colloidal-gold method

We describe ultrastructural characteristics of PRL cells with small secretory granules, immunostained with ovine antiserum, in adult Murciano-Granadina milking goats during anoestrus, the last third of gestation and lactation. This cell subtype is considered to comprise a stable population that decreases numerically during gestation and lactation, and that may change during these stages to show large granules.     

Stability study of a sulfadimidine-containing medicated premix and its mixture with farm feed

The objective of this paper was to study the stability of a medicated premix and a medicated farm feed containing sulfadimidine as the active ingredient. The medicated premix is supplied as powdered form and administered orally after mixing with animal feed. The sulfadimidine analytical method described in United States Pharmacopoeia 23 cannot be used to carry out the stability study because of its lack of specificity for different degradation products. Therefore, a high-performance liquid chromatography method was developed to assay sulfadimidine. This method was optimized and validated for the stability study. According to International Committee Harmonization (ICH) guidelines, the samples were stored under long-term testing and accelerated conditions for the stability study of the premix and the medicated farm feed. Sulfadimidine degradation was not detected in either form under any of the conditions studied.     

Arrhythmogenic right ventricular dysplasia/cardiomyopathy in a Siberian husky

A seven-month-old male Siberian husky was presented with a recent history of anorexia, hindlimb weakness and syncope. Physical examination revealed severe tachycardia, tachypnoea and dyspnoea. Mucous membranes were pale and femoral pulses were weak. An electrocardiogram showed sustained ventricular tachycardia with a left bundle branch block configuration. Thoracic radiographs revealed slight right ventricular enlargement and two-dimensional echocardiography revealed mild right ventricular dilation at the cardiac apex and some hyperechogenic areas on the right side of the interventricular septum. Administration of intravenous lignocaine converted the ventricular tachycardia to sinus rhythm. The maintenance antiarrhythmic therapy consisted of oral procainamide and propranolol. Three weeks later the dog died suddenly. On postmortem examination, the right ventricular free wall was very thin at the apex, infundibulum and caudal aspect of the right ventricular parietal wall, similar to the 'triangle of dysplasia' of human patients. Histopathological examination revealed replacement of several areas of right ventricular free wall myocardium with connective tissue and fat. The right atrium and left ventricle were less severely affected by the same lesions. The clinical and pathological findings are similar to those reported in young people with arrhythmogenic right ventricular dysplasia/cardiomyopathy.     

Immunohistochemical detection of extrinsic and intrinsic mediators of apoptosis in porcine paraffin-embedded tissues

Apoptosis is a strictly regulated mechanism of cell death that involves a complex network of biochemical pathways. Whether a cell undergoes apoptosis or not depends on a delicate balance of anti- and pro-apoptotic stimuli. This phenomenon can be induced by two different pathways: intrinsic and extrinsic pathways. The main aim of this study was to determine the ideal fixative and antigen retrieval method in porcine paraffin embedded tissues for the immunohistochemical detection of apoptosis mediators, from both extrinsic and intrinsic pathways. Tonsil, retropharyngeal lymph node and lung tissue samples were fixed in 10% neutral buffered formalin, Bouin solution and zinc salts fixative (ZSF) and different unmasking methods were carried out. Both 10% neutral buffered formalin and ZSF resulted as the fixatives of election to study apoptosis phenomena. Tween 20 (0.01% in PBS), citrate buffer (microwave, pH 6.0) and/or protease type XIV were the antigen retrieval methods which displayed better labelling. Our results allow to deep in the knowledge of apoptosis and its role in the pathogenesis of porcine diseases.     

Differences in the immune response against ruminant chlamydial strains in a murine model.

CBA/J mice were used in the present study to establish differences between the immune response to three chlamydial strains: AB7 (Chlamydia psittaci wild-type strain), 1B (C. psittaci vaccinal strain) and iB1 (C. pecorum). The evolution of chlamydial infection was evaluated in each strain by studying the clinical signs, the number of bacteria isolated from the spleen and the pathology of the liver. Three aspects of the immune response were then studied: the characterization of the infiltrate of leukocytes in the liver, the percentages of T- and B-cells, macrophages and neutrophils in the spleen, and the presence of cytokines in the serum. Infection followed a different course in the C. psittaci-infected mice; 1B-infected mice showed milder levels in all the parameters analysed than their AB7-infected counterparts. The resolution of infection was earlier in 1B-infected mice and, although the immune response to both strains was Th1-like, a more intense CD8+ T-cell response and an earlier presence of TNF-alpha in serum were observed in this group. C. pecorum infection was controlled mainly by a non-specific immune response, since these mice showed no signs of a systemic specific immune response. Neutrophil depletion experiments showed that these cells play a very limited role in the non-specific response against C. pecorum.     

Serologic response of red-legged partridges (Alectoris rufa) after oral inoculation with Toxoplasma gondii oocysts

Thirty 5-month-old red-legged partridges (Alectoris rufa) reared in battery were divided into five groups: 4 birds in group A, 14 birds in group B, 4 birds in group C, 4 birds in group D and 4 birds in group E, and were inoculated orally with 10, 50, 10(2), 10(3) and 10(4) oocysts of the OV-51/95 strain of Toxoplasma gondii, respectively. During the experiment, blood samples from all birds were drawn every 3-7 days and at necropsy. Serologic response was measured by the modified agglutination test (MAT) and the latex agglutination test (LAT). One bird from each group was killed at 44, 58, 65 and 72 days after inoculation (DAI). From 72 DAI to the end of the experiment, surviving partridges from group B were killed at weekly intervals. The last partridges were sacrified 100 DAI. MAT was the most sensitive and specific test for detecting T. gondii antibodies in the birds. First positive titers were detected by MAT in all sera on 7 DAI, but titers by LAT did not appear until 13 DAI. Antibody titers detected by MAT on 7 DAI were higher in the partridges with the largest inocula (10(3) or 10(4) oocysts) than those inoculated with 10, 50 or 10(2) oocysts. All surviving birds developed a serologic response to T. gondii, with maximum titers of 512-32,768 in the MAT on 13-17 DAI, and positive titers persisted at least until 100 DAI. To the contrary, LAT reveals only very low antibody titers even in partridges inoculated with the highest dose of T. gondii.     

Relationship between serum acute phase protein concentrations and lesions in finishing pigs

To establish the relationship between serum levels of three acute phase proteins, haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA), and the occurrence and severity of lesions at slaughter, a study was carried out using 70 fattening pigs from a finishing unit. Pigs were divided into three groups: Group 1 (25 pigs with clinical signs of disease), Group 2 (25 apparently healthy pigs with lesions at slaughter) and Group 3 (20 apparently healthy pigs with no lesions at slaughter). Serum levels of CRP, SAA and Hp were significantly higher in pigs with clinical signs of disease than in apparently healthy animals. Additionally, in apparently healthy pigs, serum levels of Hp and CRP were significantly higher in animals with lesions than those without lesions. The extent and severity of lung lesions were related to serum levels of Hp.