Distribution of porcine circovirus 2 cap antigen in the lymphoid tissue of pigs affected by postweaning multisystemic wasting syndrome

The lymphatic organs of 50 pigs from a total of eight farms located at different sites in the epizootiological region of North Ba?ka County were studied to obtain data on the prevalence of circoviral infections in Serbia. All of the pigs examined had clinical signs suggestive of postweaning multisystemic wasting syndrome (PMWS). All pigs underwent necropsy and tissue samples were taken for histopathological, immunohistochemical (IHC) and PCR analysis. The presence of porcine circovirus 2 (PCV2) was established by PCR analysis in the organs of the pigs tested. The most frequent histopathological lesions of lymphoid tissue linked with the presence of positive immunostaining for PCV2 Cap antigen confirmed the existence of PMWS in all farms tested in North Ba?ka County. Using PCR, histopathological and IHC techniques, the presence of PMWS was proved in the Republic of Serbia. During necropsy, generalised enlargement of the lymph nodes was evident. The most common histopathological finding was lymphocyte depletion in the follicular and perifollicular areas of lymph nodes. Infiltration by macrophages was also recorded. By IHC analysis, the cytoplasm of macrophages was shown to contain a large amount of the ORF2-coded Cap antigen of PCV2. Lymphocyte depletion and large numbers of macrophages were recorded in the tonsils, spleen, intestinal lymphatic tissue, Peyer's patches and ileocaecal valve. The presence of typical granulomatous lesions with multinuclear giant cells (MGCs) was also recorded in the lymphatic tissue. Cap antigen was shown to be present in macrophages and less often in lymphocytes.     

Biomechanical comparison of orthofix pins and cortical bone screws in a canine humeral condylar fracture model

OBJECTIVE: To compare shear stability of simulated humeral lateral condylar fractures reduced with either a self-compressing pin or cortical bone screw. STUDY DESIGN: In vitro biomechanical tests. SAMPLE POPULATION: Bilateral cadaveric canine humeri (n=18) without evidence of elbow disease. METHODS: Lateral condylar fracture was simulated by standardized osteotomy. Bone fragments were stabilized with a self-compressing pin or a cortical bone screw (2.7 or 3.5 mm) inserted in lag fashion. Specimens were mounted in a materials testing system and the condylar fragment displaced in a proximal direction until failure. Mechanical testing variables derived from load-deformation curves were compared between stabilization methods using a Student's paired t-test. RESULTS: There were no statistically significant differences for mechanical testing variables between pin and screw stabilized specimens at expected walk and trot loads. Three yield points subjectively coincided with yield of the interfragmentary interface (Y1), bone at the implant interface (Y2), and implant deformation (Y3). Displacements at Y1 were 48-156% greater for pin than screw stabilized specimens. Y2 and Y3 loads were higher for screw than pin stabilized specimens, but likely supraphysiologic for dogs convalescing after surgical repair. CONCLUSIONS: A self-compressing pin or a cortical bone screw inserted in lag fashion both provided adequate strength in applied shear to sustain expected physiologic loads through the repaired canine elbow during postoperative convalescence. CLINICAL RELEVANCE: Because self-compressing pins were easy to implant and mechanical properties were not significantly different than cortical screws at expected physiologic loads, pins should be considered for the repair of traumatic humeral condylar fractures.     

Relationship between concentration of citrate and ketone bodies in cow's milk

The authors' hypothesis is that the members of the tricarboxylic acid cycle (TCA cycle) such as citrate decrease in association with increased ketone body formation. To prove this hypothesis the connection between ketone bodies and citrate formation of milk was studied. A fluorimetric method was used to determine citrate and a headspace sampling gas chromatographic (GC) method was developed for determination of ketone bodies. Under real conditions of milk sampling, transport and storage, preserved milk samples of 119 clinically healthy dairy cows obtained in the 48 hours after milking were investigated. A low level of acetoacetate (ACAC) was found in all samples. This fact can be explained by the spontaneous decarboxylation of acetoacetate during sample storage (previously decarboxylised acetoacetate = pdACAC) and, consequently, the majority of the amount of acetoacetate in the samples (AC + pdACAC) appeared in the measured acetone concentrations. Based on the measured acetone concentration of milk samples two groups were formed retrospectively: HA (high-acetone) group (n = 41) with an AC + pdACAC concentration of > 0.4 mmol/l and a LA (low-acetone) group (n = 78) with an AC + pdACAC level of < or = 0.4 mmol/l. In the milk of cows of Group HA a positive correlation (r = +0.623) and linear connection between acetone (AC + pdACAC) and beta-hydroxybutyrate (BOHB) levels was found [BOHB = 2.491 + 0.586 x (pdAC + ACAC)]. Furthermore, in this group a negative correlation between citrate and BOHB and AC + pdACAC was also established (r = -0.579). Focusing on the results of this group the authors found a significant drop of AC + pdACAC and citrate during the metabolically critical first 1-4 weeks of lactation. For this reason they suggest that simple, easy, automated methods (i.e. flow injection analysis, Fourier transformation infrared analysis) should be introduced for the simultaneous determination of acetone and citrate concentration in milk to make the evaluation of the energy status of high-producing dairy cows easier and more certain.     

Structure-activity relationships in a series of new antifungal nitroalcohol derivatives

The structure-antifungal activity correlations of 23 new nitroalcohol derivatives (1-substituted-2-nitropropane-1, 3-diols, their ethers and esters) were investigated using a generalised quantitative structure-activity relationships (QSAR) method, combining Golender and Rozenblit's logico-structural approach and the Free-Wilson and Hansch analyses. Based on results obtained from principal component analysis, the in-vitro activities against Helminthosporium sativum, the inhibition of germination and of growth could be assumed to be governed by a common mechanism. It is suggested that the antifungal activity of the compounds studied is determined mainly by the presence or absence of an aromatic ring (unsubstituted, or bearing a hydrophobic group that is small in bulk and electron-attracting) at position 1, of a (potential) double bond between carbon atoms 1 and 2, and of an acyloxy group at position 3. Among these factors, the double bond seems to be the most important, and the mechanism of the antifungal action is probably dependent on the reactivity of this bond towards thiol groups of endogenous substances.