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In vivo and in vitro comparisons of spray-drying and solvent-evaporation preparation of microencapsulated Mycoplasma hyopneumoniae for use as an orally administered vaccine for pigs
2002
Lin, J.H. | Pan, M.J. | Liao, C.W. | Weng, C.N.
Objective-To evaluate the efficacy of an orally administered vaccine of Mycoplasma hyopneumoniae that was prepared by spray drying or solvent evaporation. Animals-Thirty 6-week-old, crossbred, specificpathogen- free (SPF) pigs. Procedure-Pigs were randomly allocated into 5 groups and housed in an SPF facility. Pigs in 2 groups (groups AQ and CAP) were fed M hyopneumoniae enteric-coated vaccine on days 0, 10, and 20. A third group (group IM) received an IM injection of M hyopneumoniae vaccine with aluminium hydroxide as an adjuvant on days 0, 10, and 20. The last 2 groups (nonvaccinated- challenged [NV-C] and nonchallenged [NC]) were fed a sham treatment. All 24 pigs in groups AQ, CAP, IM, and NV-C were challenge exposed with 5 ml of a 10% pneumonic lung suspension administered on day 40 via intubation of the trachea. All pigs were slaughtered and the lungs removed and examined for lesions on day 68. Results-In vitro studies indicated that these 2 microencapsulation techniques formed an effective shell and protected mycoplasmal antigen from gastric acid. Results of inoculation and challenge tests indicated that microencapsulated M hyopneumoniae were sufficiently potent to induce an immune response and provide good protection. Conclusions and Clinical Relevance-Orally administered microencapsulated M hyopneumoniae vaccines induced an immune response and reduced the severity of lung lesions in challengeexposed pigs. Results suggest that this novel method can be applied to other antigens, because the spray-drying process yielded an orally administered M hyopneumoniae vaccine that induced a good immune response.
Afficher plus [+] Moins [-]Purification and partial characterization of canine pepsinogen A and B
2002
Suchodolski, Jan S. | Steiner, Jörg M. | Ruaux, Craig G. | Boari, Andrea | Williams, David A.
Objective-To purify and partially characterize various isoforms of canine pepsinogen (PG) from gastric mucosa. Sample Population-Stomachs obtained from 6 euthanatized dogs. Procedure-Mucosa was scraped from canine stomachs, and a crude mucosal extract was prepared and further purified by use of weak anion-exchange chromatography, hydroxyapatite chromatography, size exclusion chromatography, and strong anionexchange chromatography. Pepsinogens were characterized by estimation of molecular weights, estimation of their isoelectric points (IEPs), and N-terminal amino acid sequencing. Results-Two different groups of canine PG were identified after the final strong anion-exchange chromatography: PG A and PG B. Pepsinogens differed in their molecular weights and IEP. Pepsinogen B appeared to be a dimer with a molecular weight of approximately 34,100 and an IEP of 4.9. Pepsinogen A separated into several isoforms. Molecular weights for the various isoforms of PG A ranged from 34,200 to 42,100, and their IEPs ranged from 4.0 to < 3.0. The N-terminal amino acid sequence for the first 25 amino acid residues for PG A and B had good homology with the amino acid sequences for these proteins in other species. Conclusions and Clinical Relevance-Canine PG B and several isoforms of canine PG A have been purified. Availability of these PGs will facilitate development of immunoassays to measure PG in canine serum as a potential diagnostic marker for gastric disorders in dogs.
Afficher plus [+] Moins [-]Effect of oxytocin treatment in sows on umbilical cord morphology, meconium staining, and neonatal mortality of piglets
2002
Mota-Rojas, Daniel | Martínez Burnes, Julio | Trujillo-Ortega, Maria Elena | Alonso-Spilsbury, Ma Lourdes | Ramírez Necoechea, Ramiro | López, Alfonso
Objective-To evaluate the effect of 2 oxytocin products administered to sows at the onset of fetal expulsion on the integrity of umbilical cords, meconium staining, and piglet mortality. Animals-2099 neonatal pigs. Procedure-180 parturient sows were randomly assigned to 3 stratified groups of 60 sows each. Two groups of sows were injected IM at the onset of fetal expulsion with 1 of 2 oxytocin commercial products (20, 40, or 50 U for sows weighing 120 to 150 kg, 151 to 250 kg, or ≥ 251 kg, respectively). Control sows were treated IM with saline (0.9% NaCl) solution. Farrowing time, expulsion intervals, and numbers of stillborn and liveborn piglets were recorded for each sow. Piglets were evaluated for inspiratory effort, heart rates, and degree of meconium staining of skin (nonstained, and moderately or severely stained). Umbilical cords were classified as normal in appearance, edematous, congested, hemorrhagic, or ruptured. Results-Oxytocin-treated sows had a significant decrease in farrowing time and expulsion intervals and also had a significantly higher number of stillborn piglets per litter, compared with control sows. The number of piglets per litter with ruptured and hemorrhagic umbilical cords was significantly greater in oxytocin- treated sows, compared with control sows. In near-death stillborn piglets, oxytocin treatment significantly decreased inspiratory efforts at birth and increased the rate and severity of meconium staining, compared with saline treatment. Conclusions and Clinical Relevance-Oxytocin given to sows at the onset of fetal expulsion significantly increases the rate of fetal distress, anoxia, and intrapartum death in piglets.
Afficher plus [+] Moins [-]Evaluation of bacteriologic culture of pooled fecal samples for detection of Mycobacterium paratuberculosis
2002
Wells, Scott J. | Whitlock, Robert H. | Lindeman, Cynthia J. | Fyock, Terry
Objective-To compare sensitivity of several methods of bacteriologic culture of pooled bovine fecal samples for detection of Mycobacterium paratuberculosis and evaluate homogeneity in number of M paratuberculosisin pooled fecal samples. Sample Population-Feces from 10 dairy cows that shed M paratuberculosis at various concentrations and 1 dairy cow known to be free of infection with M paratuberculosis. Procedure-5 fecal pooling methods, 2 culture methods, and 2 pool sizes were evaluated. Each pooled sample contained 1 infected sample and 4 or 9 uninfected samples. Results-Sensitivity of detection of M paratuberculosis was greater with smaller pool size (5 vs 10 samples/ pool). Detection sensitivity was also associated with concentration of bacteria in the infected sample. Results indicated that, compared with concurrent bacterial culture of individual infected samples, 37 to 44% of pooled samples with low bacterial concentrations yielded positive culture results and 94% of pooled samples with high bacterial concentrations yielded positive results. Conclusions and Clinical Relevance-Bacteriologic culture of pooled fecal samples may provide a valid and cost-effective method of detecting M paratuberculosis infection in cattle herds.
Afficher plus [+] Moins [-]Hematologic and serum biochemical changes in Salmonella ser Typhimurium-infected calves
2002
Santos, Renato L. | Tsolis, Renée M. | Bäumler, Andreas J. | Adams, L Garry
Objective-To evaluate hematologic and serum biochemical changes in Salmonella ser Typhimurium infected calves. Animals-16 male 3- to 4-week-old dairy calves. Procedure-13 calves were experimentally infected with S Typhimurium (strains IR715 and CS401, which are derivatives of ATCC 14028), and 3 calves were uninfected controls. Several hematologic and serum biochemical parameters were measured. Results-Hematologic changes included increases in PCV, RBC count, and hemoglobin concentration, associated with a transitory leukopenia characterized by neutropenia and lymphopenia. Biochemical findings included hypoglycemia, increased BUN, creatinine, and fibrinogen concentrations, and decreased sodium, total CO2, calcium, total protein, and albumin concentrations. Increased total bilirubin concentration associated with decreased conjugated bilirubin concentration was also observed. No significant changes in aspartate aminotransferase, gamma-glutamyltranspeptidase, alkaline phosphatase, and creatinine kinase activities were detecte Conclusions and Clinical Relevance-Experimental salmonellosis of calves results in marked to severe dehydration, accompanied by metabolic acidosis, hypoglycemia, and an acute inflammatory response associated with increased fibrinogen concentrations and severe neutropenia immediately after inoculation.
Afficher plus [+] Moins [-]Evaluation of tartrate-resistant acid phosphatase and cathepsin K in ruptured cranial cruciate ligaments in dogs
2002
Muir, Peter | Hayashi, Kei | Manley, Paul A. | Colopy, Sara A. | Hao, Zhengling
Objective-To determine localization of tartrate-resistant acid phosphatase (TRAP) and cathepsin K in ruptured and healthy cranial cruciate ligaments (CCL) in dogs. Animals-30 dogs with ruptured CCL, 8 aged dogs without ruptured CCL, and 9 young dogs without ruptured CCL. Procedure-The CCL was examined histologically and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively. Results-Cathepsin K and TRAP were detected within the same cells, principally within the epiligamentous region and to a lesser extent in the core region of ruptured CCL. Numbers of cells containing TRAP and cathepsin K were significantly greater in ruptured CCL, compared with CCL from young or aged dogs, and numbers of such cells were greater in CCL from aged dogs, compared with those of young dogs. In aged dogs, small numbers of cells containing TRAP and cathepsin K were seen in intact CCL associated with ligament fascicles in which there was chondroid transformation of ligament fibroblasts and disruption of the extracellular matrix. Conclusion and Clinical Relevance-Ruptured CCL contain greater numbers of cells with the proteinases TRAP and cathepsin K than CCL from healthy, young, or aged dogs. Results suggest that cell-signaling pathways that regulate expression of these proteinases may form part of the mechanism that leads to upregulation of collagenolytic ligament remodeling and progressive structural failure of the CCL over time.
Afficher plus [+] Moins [-]Changes in concentrations of neuroendocrine hormones and catecholamines in dogs with myocardial failure induced by rapid ventricular pacing
2002
Roche, Brian M. | Schwartz, Denise | Lehnhard, Robert A. | McKeever, Kenneth H. | Nakayama, Tomohiro | Kirby, Timothy E. | Robitaille, Pierre-Marie L. | Hamlin, Robert L.
Objective-To describe neuroendocrine responses that develop in dogs subjected to prolonged periods of ventricular pacing. Animals-14 adult male hound-type dogs. Procedure-Samples were obtained and neuroendocrine responses measured before (baseline) and after 3 periods of ventricular pacing. A pacemaker was used to induce heart rates of 180, 200, and 220 beats/min (BPM). Each heart rate was maintained for 3 weeks before increasing to the next rate. Atrial natriuretic peptide, antidiuretic hormone, aldosterone, norepinephrine, epinephrine, and dopamine concentrations and plasma renin activity were measured. Severity of left ventricular compromise was estimated. Results-Shortening fraction decreased significantly with increasing heart rates (mean +/- SE, 35.5 +/- 1.4, 25.0 +/- 1.4, 19.5 +/- 1.9, and 12.2 +/- 2.3 for baseline, 180 BPM, 200 BPM, and 220 BPM, respectively). Atrial natriuretic peptide concentrations increased significantly at 180 BPM (44.1 +/- 3.0 pg/mL) and 200 BPM (54.8 +/- 5.5 pg/mL), compared with baseline concentration (36.8 +/- 2.6 pg/mL). Dopamine concentration increased significantly at 200 BPM (70.4 +/- 10.4 pg/mL), compared with baseline concentration (44.2 +/- 7.3 pg/mL). Norepinephrine concentrations increased significantly from baseline concentration (451 +/- 46.2 pg/mL) to 678 +/- 69.8, 856 +/- 99.6, and 1,003 +/- 267.6 pg/mL at 180, 200, and 220 BPM, respectively. Conclusions and Clinical Relevance-Dogs subjected to ventricular pacing for 9 weeks developed neuroendocrine responses similar to those that develop in humans with more chronic heart failure and, except for epinephrine concentrations, similar to those for dogs subjected to ventricular pacing for < 6 weeks.
Afficher plus [+] Moins [-]Blood meal acquisition by ticks; molecular advances and implications for vaccine development
2002
Mulenga, A. (Hokkaido Univ., Sapporo (Japan)) | Tsuda, A. | Sugimoto, C. | Onuma, M.
In their quest for a blood meal, hematophagous arthropods must first defeat the host's hemostatic defense. Following injury as it occurs when hematophagous arthropods insert their proboscis into host skin to feed, the host will attempt to stop excessive blood loss through its hemostatic defense mechanism involving platelet aggregation, blood clotting and vasoconstriction. To acquire a full blood meal hematophagous arthropods inject an arsenal of bioactive enzymes which ultimately overpower the host's hemostatic defense. We have looked at a selected number of studies on the molecular biology of arthropod anti-hemostatic proteins and developed commentaries on the suitability of these molecules as target tick vaccine antigens.
Afficher plus [+] Moins [-]Taenia taeniaeformis larval product induces gastric mucosal hyperplasia in SCID mice
2002
Lagapa, J.T.G. (Hokkaido Univ., Sapporo (Japan)) | Oku, Y. | Nonaka, N. | Kamiya, M.
The effects of intraperitoneal implantation of Taenia taeniaeformis larvae and inoculation of in vitro larval products on gastric mucosa of SCID mice were investigated in this study. Mice surgically implanted with T, taeniaeformis larvae developed slight and moderate gastric hyperplasia. When in vitro cultured T. taeniaeformis larval excretory-secretory (TtLES) products containing 1 mg of protein were injected daily into mice, they caused gastropathy after 5-7 days. Mice injected daily with 0.5 mg of TtLES products also showed slight gastric hyperplasia after day 14 and 28. The gastropathy was characterized by reduction of both parietal and zymogenic cell number and increased number of alcian blue-periodic acid Schiff (AB-PAS)-positive cells and by two-fold extension of proliferative zone of gastric units. Larval implantation demonstrated a more potent effect in inducing gastropathy than did in vitro larval culture products. Significant decrease in number of parietal cells with con-comitant increase of tive zone and AB-PAS-positive cell number indicated their important roles in inducing the hyperplastic lesion. Similarities with other gastropathies indicated that there is a common fundamental regulatory mechanism involved, and that the host response may not be specific to parasites. Present study validated the induction of gastric mucosal hyperplasia by larval ES products of T. taeniaeformis. This proved the hypothesis of previous studies suggesting the role of larvae-derived products in inducing gastric mucosal hyperplasia in T. taeniaeformis-infected rats.
Afficher plus [+] Moins [-]Efficiency of fecal steroid hormone measurement for assessing reproductive function in the Hokkaido brown bear (Ursus arctos yesoensis)
2002
Ishikawa, A. (Hokkaido Univ., Sapporo (Japan)) | Kikuchi, S. | Katagiri, S. | Sakamoto, H. | Takahashi, Y.
The present study aimed to establish simple systems for measuring fecal steroid hormones in order to monitor the reproductive profiles of captive Hokkaido brown bears. The efficiency of fecal sample processing at the steps of dehydration and extraction and the correlation between steroid concentrations in matched fecal and blood samples were studied. Then, monthly changes in fecal estradiol-17beta and progesterone in female bears, and testosterone in male bears were examined. The procedure was finalized as follows. Fecal samples were dried at 100degC for 3 hr and extracted with diethyl ether. The diethyl ether in the extracts was evaporated and residues were reconstituted in ethanol for the assays. Hormone concentrations were quantified using enzyme immunoassays. Concentrations of progesterone and testosterone in fecal and plasma samples were correlated in the systems. The changes in fecal progesterone and testosterone concentrations were similar to those in serum concentrations of bears as reported previously. In contrast, fecal estradiol concentrations did not correlate with plasma levels probably because of the time lag in excretion. However, the changes in estradiol-17beta concentrations in feces in the present study were similar to those reported in serum. In conclusion, fecal progesterone and testosterone assay systems appear practical for monitoring ovarian and testicular activities without immobilization, though methodological improvements and further validation may be required. For the fecal estradiol-17beta assay, there is a need to solve the problem of excretion time lag before the system can be used in the study of reproductive physiology.
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