Field trials of a formulation containing moxidectin and 6 in 1 vaccines for sheep

Objective: To assess the efficacy and safety of a formulation containing moxidectin and 6 in 1 vaccine in sheep under field conditions.
Design: Efficacy and safety study.
Animals: Two hundred and five crossbred Merino lambs and two hundred and eight Merino ewes were used in the studies.
Procedure: A formulation was made for the simultaneous treatment of sheep with moxidectin and immunisation against clostridial diseases and caseous lymphadenitis. The efficacy against nematodes, vaccine response and safety were assessed.
Results: Effective control of nematodes and responses to antigens were achieved following subcutaneous administration. The formulation was safe to administer; occasional minor tissue reactions were evident, but no other adverse effects of treatment were observed in either pregnant ewes or lambs, using either the recommended dose, or an overdose of the formulation.
Conclusion: Administration of a formulation containing moxidectin, five clostridial antigens and caseous lymphadenitis antigen proved safe and efficacious under field conditions.     

Definition of the specificity of monoclonal antibodies against porcine CD45 and CD45R: report from the CD45/CD45R and CD44 subgroup of the Second International Swine CD Workshop

Swine cell binding analyses of a set of 48 monoclonal antibodies (mAbs), including eleven standards, assigned to the CD44 and CD45 subset group of the Second International Swine CD Workshop yielded 13 clusters. Although none of these corresponded to CD44, seven mAbs formed a cluster which was identified as being specific for restricted epitopes of CD45 (CD45R). In addition, a T-cell subset specific cluster comprised of four mAbs was also identified. Two mAbs (STH106 and SwNL 554.1) reacted exclusively with CD8 bright lymphocytes, the other two (2B11 and F01G9) with a subset of CD4 lymphocytes. The other 10 clusters were either specific for MHC-class I like molecules or overlapped with clusters identified by the adhesion molecule subgroup and are therefore just briefly discussed in this report. The specificity of all the mAbs in the CD45R cluster was verified by their ability to immunoprecipitate distinct proteins and to react with CHO cells expressing individual isoforms of CD45. Three CD45R mAbs (3a56, MIL5, −a2) did react with a 210 kDa isoform(s), while another three (STH267, FG2F9, 6E3/7) only recognized a 226 kDa isoform(s). The remaining one (MAC326) precipitated both a 210 and 226 kDa protein. The specificity of all the mAbs in the CD45R cluster, and of the CD45 common mAbs, was confirmed by their reactivity with CHO cells transfected with cDNAs encoding the extracellular and transmembrane portions of distinct CD45R isoforms. Those mAbs recognizing a 210 kDa protein reacted with CHO cells expressing the CD45RC isoform, while those capable of precipitating a 226 kDa, but not the 210 kDa, polypeptide recognized CHO cells expressing either the CD45RAC and the relatively rare CD45RA isoform. MAC326 was unique in its inability to react with CHO cells engineered to produce the CD45RC and CD45RAC isoforms. Thus, three mAbs (6E3/7, STH267, and FG2F9) appear to be specific for an epitope(s) encoded by the A exon, while one (MAC326) recognizes a determinant encoded by the C exon. The remaining three mAbs (3a56, −a2, MIL5) are apparently specific for an epitope(s) which results from the fusion of the C exon to the invariant leader sequence and is destroyed by inclusion of the A exon. All three CD45 common mAbs, K252.1E4, MAC323 and 74.9.3, did react with the CHO cells lines expressing either the CD45RA, CD45RC, CD45RAC or CD45RO isoforms, but not with untransfected CHO cells. When the natural expression of CD45 isoforms was examined by reacting lymphocytes with CD45R mAbs, a high level expression of isoforms containing the A exon-generated domain was detected in all B cells while the majority of CD4⁺ T cells had undetectable or lower expression density of this protein than B cells. In contrast, the density of expression of the CD45 isoform(s) containing the C exon-generated domain ranged from undetectable to high in CD4⁺ T cells whereas the amounts were approximately ten-fold lower in B cells. Overall this panel of CD45 mAbs will be very useful in analyzing the maturation and differentiation of swine lymphoid cells subsets.     

Effects of Interferon‐Tau and Steroids on Cytochrome P450 Activity in Bovine Endometrial Epithelial Cells

The objective of the current study was to examine cyclooxygenase (COX), cytochrome P450 1A (CYP1A) and 2C (CYP2C) activity in bovine endometrial cell cultures following exposure to oxytocin (OT), interferon‐τ (IFN), estradiol (E2) and/or progesterone (P4). Bovine endometrial epithelial cells were treated with OT, IFN, a combination of OT+IFN or control (CON) media for 24 h. For the second experiment, cells were treated with E2, P4, a combination of E2 + P4 or CON media for 24 h. Treatments were performed in triplicate, and the experiment was repeated four times (n = 12 per treatment). Treatment with OT alone increased (p < 0.01) activity of COX compared with CON; however, OT alone did not alter activity of CYP1A (p = 0.55) or CYP2C (p = 0.46) compared with CON. Activity of CYP1A and CYP2C was decreased in cells exposed to IFN (p < 0.01) or OT+IFN (p < 0.01) compared with CON. Treatment with E2 alone did not alter activity of CYP1A (p = 0.64) or CYP2C (p = 0.06) compared with CON. Activity of CYP1A and CYP2C was decreased (p < 0.01) in P4 vs CON. In summary, IFN exposure, irrespective of OT treatment, decreased the activity of CYP1A and CYP2C. Activity of CYP1A was decreased following P4 treatment alone, while that of CYP2C was decreased following both P4 and E2 + P4 treatment. The mixed function monooxygenase enzymes, CYP1A and CYP2C, have been implicated in synthesizing embryotoxic compounds; therefore, downregulation in the endometrium may be necessary during maternal recognition of pregnancy.     

The effect of time between doses on serological response to a recombinant multivalent pilus vaccine against footrot in sheep

SUMMARY The response of sheep to a recombinant multivalent footrot vaccine containing pilus antigens was examined after the administration of two doses of vaccine at Intervals ranging from 2 to 52 weeks. Agglutinating antibody titres were measured 3 weeks after the second vaccination and showed that lengthening of the interdose interval results in higher agglutinin titres. The capability of sheep to mount an increasingly strong immune response as the interval between doses is increased provides an opportunity to maximise the usefulness of vaccination by administering the first dose well before an expected footrot transmission period. This advantage of increasing the interdose interval has not been reported for traditional, whole-cell footrot vaccines, and use of the new pilus vaccine in this manner may improve prospects for disease control. Furthermore, sheep given a third dose either 6 or 12 months after their initial two-dose vaccination program achieved significantly higher titres than those elicited after the second dose, suggesting the likelihood of further improvement in disease control in successive seasons.     

Fixation technique influences the monotonic properties of equine mandibular fracture constructs

OBJECTIVE: To determine the optimal fixation technique for equine interdental space fractures by evaluating the biomechanical characteristics of 4 fixation techniques. STUDY DESIGN: In vitro randomized block design. SAMPLE POPULATION: Twenty-seven adult equine mandibles. METHODS: Mandibles with interdental osteotomies were randomly divided into 4 fixation groups (n = 6/group). Fixation techniques were the following: (1) dynamic compression plates (DCP), (2) external fixator (EF), (3) external fixator with interdental wires (EFW), and (4) intraoral splint with interdental wires (ISW). Three intact (nonosteotomized) mandibles were tested as controls. Mandibles were subjected to monotonic cantilever bending until failure. Angular displacement data (radians) were derived from continuously recorded gap width measurements provided by extensometers placed across the osteotomy site. Osteotomy gap width data (mm) at 50 and 100 Nm were selected for standardized comparison of gap width before the yield point and failure point, respectively of all constructs tested. Stiffness (Nm/radian), yield strength (Nm), and failure strength (Nm) were determined from bending moment-angular displacement curves and were compared using ANOVA with appropriate post hoc testing when indicated. Radiographs were obtained prefixation, postfixation, and posttesting. RESULTS: Bending stiffness, yield, and ultimate failure loads were greatest for intact mandibles. Among osteotomized mandibles, stiffness was greatest for DCP constructs (P <.05) and was not significantly different among EF, EFW, and ISW constructs. Yield load was greatest for ISW constructs (P <.05) and was not significantly different among DCP and EFW constructs. Yield and ultimate failure loads were lowest (P <.05) and osteotomy gap width at 50 and 100 Nm were greatest for EF constructs (P =.09 and P <.05, respectively). There was no significant difference in failure loads and osteotomy gap widths among DCP, EFW, and ISW constructs (P <.05). Failure occurred through the screw-bone interface (DCP), acrylic splint (ISW), acrylic connecting bar and/or pin-bone interface (EF, EFW), and wire loosening (EFW). All 3 intact mandibles fractured through the vertical ramus at its attachment to the testing apparatus. CONCLUSIONS: Among osteotomized mandibles, DCP fixation had the greatest stiffness under monotonic bending to failure; however, the relatively low yield value may predispose it to earlier failure in fatigue testing without supplemental fixation. Techniques using tension-band wiring (EFW and ISW) were similar to DCP constructs in yield, failure, and osteotomy displacement, whereas EF constructs were biomechanically inferior to all other constructs. CLINICAL RELEVANCE: DCP fixation is most likely the most stable form of fixation for comminuted interdental space fractures. However, for simple interdental space fractures, ISW fixation may provide adequate stability with minimal invasiveness and decreased expense. Tension-band wiring significantly enhances the strength of type II external skeletal fixators and should be used to augment mandibular fracture repairs.     

Mangrove expansion and population structure at a planted site,East London,South Africa

Avicennia marina (Forrsk.) Vierh. was planted in 1969 at Nahoon Estuary, East London, followed a few years later by the planting of Bruguiera gymnorrhiza (L.) Lam. and Rhizophora mucronata (L.) among the larger A. marina trees. This study tested the hypothesis that mangroves have expanded and replaced salt marsh over a 33-year period (1978–2011). It provides important information on mangroves growing at higher latitudes, where they were thought to not occur naturally due to lower annual average temperatures. It further provides insights on future scenarios of possible shifts in vegetation types due to climate change at one of the most southerly distribution sites worldwide. The expansion of mangroves was measured using past aerial photographs and Esri ArcGIS Desktop 10 software. In addition, field surveys were completed in 2011 to determine the population structure of the present mangrove forest and relate this to environmental conditions. The study showed that mangrove area cover increased linearly at a rate of 0.06 ha y^?1, while the salt marsh area cover also increased (0.09 ha y^?1) but was found to be variable over time. The mangrove area is still relatively small (<2 ha) and expanded mostly over a bare sandflat area. Avicennia marina was the dominant species and had high recruitment (seedling density was 33 822 ± 16 364 ha^?1). Only a few Bruguiera gymnorrhiza and Rhizophora mucronata individuals were found (<10 adult trees), although observations indicate that some young plants are becoming established away from the parent plants. The site provides opportunities for studies on mangrove/salt marsh interactions in response to a changing climate. Mangroves should not be planted in non-native areas as they may become invasive outside their natural range. However, future increases in temperature will certainly lead to a southerly expansion of mangoves in South African estuaries.     

Induction of Chitinase and β-1,3-Endoglucanase Proteins by UV Irradiation and Wounding in Grapefruit Peel Tissue

UV irradiation enhanced the resistance of grapefruit against the development of green mold décay caused byPenicillium digitatum, the main postharvest pathogen of citrus fruit, and significantly inhibited the fungus’ growth at the fruit wound sites. Immunoblotting analysis using specific citrus chitinase and β-1,3-endoglucanase antibodies, showed that UV irradiation, wounding of the fruit, or a combination of these two treatments, induced the accumulation of a 25 kD chitinase protein in the fruit’s peel tissue. On the other hand, UV irradiation or wounding of the fruit alone was unable to induce the accumulation of 39 and 43 kD β-1,3-endoglucanase proteins, but the combination of the two treatments increased these protein levels. It is suggested that both chitinase and β-1,3-endoglucanase may play a role in the UV-induced resistance of grapefruit againstP. digitatum. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 403/99. http://www.phytoparasitica.org posting June 3, 1999.     

Methods of detection of Chlamydia psittaci in domesticated and wild birds

OBJECTIVE: To study the occurrence of Chlamydia psittaci in domesticated and wild birds and compare the sensitivity of molecular detection with cell culture isolation. DESIGN: Study of cell culture isolation and PCR detection of C psittaci in avian samples. PROCEDURE: Samples were obtained from 485 birds. Domesticated birds were selected at random from pet shops, private aviaries and zoos, while wild birds were captured locally, sampled, and immediately released. Swabs were collected from choanal slit, conjunctiva and cloaca of each bird and pooled. Samples were divided into equal portions for use in PCR dot-blot and cell culture detection. PCR and dot-blot detection was based on the ompB gene. RESULTS: Prevalence of infection varied markedly between flocks of captive birds. It was highest where there were frequent changes in the flock members or where there were many birds confined in small areas. C psittaci was not detected in wild birds or water birds. The sensitivity of cell culture compared to PCR dot-blot detection was 68%. All samples positive by cell culture were also positive by PCR. CONCLUSIONS: PCR-dot blot detection of C psittaci in birds appears to be more sensitive than cell culture isolation in this study. C psittaci infection of birds may occur in clinically normal captive birds.