Use of a pool-raft system for recovery of horses from general anesthesia: 393 horses (1984-2000)

OBJECTIVE: To describe the pool-raft recovery system protocol and to evaluate the clinical outcome in horses that underwent recovery from general anesthesia using this system. DESIGN: Retrospective study. ANIMALS: 393 horses that underwent recovery from general anesthesia in the pool-raft system. PROCEDURE: Anesthetic records were examined from horses recovered from anesthesia in the pool-raft system between January 1984 and December 2000. Complete medical records of horses were examined when available. Information regarding the anesthetic and recovery period was recorded. Horses first recovered from general anesthesia in the pool-raft and, once awake, were transported to a recovery stall and lowered to the floor in a standing position. RESULTS: 351 horses underwent 1 pool-raft recovery, and 42 horses underwent multiple pool-raft recoveries. Most horses were recovered from general anesthesia within the pool-raft system to safeguard repair of a major orthopedic injury. During 471 pool-raft recoveries, 34 (7%) horses had complications within the recovery pool and 62 (13%) had complications within the recovery stall. Deaths resulted from complete failure of internal fixation, pulmonary dysfunction, or a combination of pulmonary dysfunction and fixation failure in 2% (10/471) of horses that underwent pool-raft recoveries. CONCLUSIONS AND CLINICAL RELEVANCE: The pool-raft system is a good option for recovery from general anesthesia. Although not a fail-safe system, it appears to decrease the complications of recovering horses in a high-risk category. Potential disadvantages of this system are added expense and manpower necessary in building, maintenance, and usage, as well as size limitations of the raft itself.     

Porcine antimicrobial peptides: new prospects for ancient molecules of host defense

Antimicrobial peptides (AMPs) are small, endogenous, polycationic molecules that constitute a ubiquitous and significant component of innate immunity. These natural antibiotics have broad microbicidal activity against various bacteria, fungi, and enveloped viruses. Because most AMPs kill bacteria by physical disruption of cell membranes, which may prevent microorganisms from developing resistance against these agents, they are being explored as possible alternatives to conventional antibiotics. Pigs, like many other mammals, produce an impressive array of AMPs, which are synthesized predominantly by host leukocytic phagocytes or mucosal epithelial cells. Currently, more than a dozen distinct porcine AMPs have been identified and a majority belongs to the cathelicidin family. This review briefly summarizes recent advances in porcine AMP research with an emphasis on the diverse biological functions of each peptide. Mechanisms of action of these AMPs and their role in the resistance to infections are considered. Finally, the current status of pharmaceutical and agricultural uses of AMPs as well as future prospects for their application in the food animal industry is discussed.     

Interactions of Mycoplasma hyopneumoniae membranes with porcine lymphocytes

Nonspecific mitogenicity of Mycoplasma hyopneumoniae membranes for blood lymphocytes (BL) and bronchial lymph node lymphocytes (LNL) from swine was investigated. Additionally, the influence of respiratory tract exposure to the same membrane preparation on responsiveness of these cells was evaluated. Membranes utilized in lymphocyte transformation tests and for inoculation of swine were prepared by osmotic lysis of mycoplasma cells. Conventionally reared and cesarean-derived, colostrum-deprived swine were given membranes intratracheally and responses of BL and LNL to membranes were assessed from postinoculation day 0 to 14. Utilizing a stimulation index of 3 as the cutoff, heated (56 C) M hyopneumoniae membranes exerted moderate nonspecific stimulation of BL 11 of 12 times when BL were collected from normal (control or preinoculation) swine. Similarly, LNL from conventionally reared and control groups of swine were stimulated nonspecifically 4 of 6 times by the same membrane preparations. Exposure of the respiratory tract to membranes appeared to have no influence on stimulation responses of BL at postinoculation days 6 or 13, whereas moderate to marked increases in responsiveness of LNL were detected when collected at necropsy on postinoculation days 7 or 14. These findings indicated that compartmentalization of lymphocyte sensitization in the bronchial lymph nodes resulted from respiratory tract exposure to mycoplasmal membranes. Results obtained confirm that M hyopneumoniae has a moderate nonspecific stimulatory effect on porcine lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphologic features and hydrophobicity of the cell surface of Mycoplasma hyopneumoniae.

Cell surface hydrophobicity of Mycoplasma hyopneumoniae was evaluated by phase partitioning in a hydrocarbon-aqueous mixture, by hydrophobic interaction chromatography, and by salting out with ammonium sulfate. Results obtained by use of these techniques gave evidence that the cell surface of M hyopneumoniae is weakly hydrophobic, compared with strongly hydrophobic Staphylococcus aureus Cowan I and hydrophilic Klebsiella pneumoniae. After treatment of the organisms with trypsin, M hyopneumoniae became less hydrophobic as measured by hydrophobic interaction chromatography. Significant changes in hydrophobicity were not seen after periodate treatment. Electron microscopy of M hyopneumoniae treated with polycationic ferritin revealed an intermediate, compact, unlabeled layer between the cytoplasmic membrane and an external, heavily labeled layer. Electron microscopy of ferritin-labeled M hyopneumoniae after treatment with trypsin or periodate revealed the intermediate layer to be composed of a trypsin-sensitive protein(s). The outer layer was made of periodate-sensitive carbohydrate(s). Therefore, it appears that proteins in the intermediate layer confer at least part of the total hydrophobicity of the mycoplasmal cell and may contribute to adherence of M hyopneumoniae to target respiratory cells by hydrophobic interactions.     

Metabolic effects of porcine somatotropin: nitrogen and energy balance and characterization of the temporal pattern of blood metabolites and hormones

Twelve barrows (61 kg) received daily injections of either pituitary-derived porcine somatotropin (pST; 120 micrograms/kg body weight) or an equivalent volume of excipient. Blood samples were taken 1 d before initiation and on d 9 of treatment to characterize the temporal patterns of blood hormones and metabolites. Nitrogen (N) and energy (E) balances were performed on d 14 through 19 of treatment. Pigs treated with pST retained more N than controls (38.4 vs 23.0 g/d, P less than .01) and had a slightly higher apparent digestibility of N and E (88 vs 84% and 88 vs 85%, respectively, P less than .05). However, this improvement in apparent digestibility was probably a consequence of the lower feed intake (23% reduction) rather than a direct effect of pST. Treatment with pST resulted in chronic elevations in circulating concentrations of insulin-like growth factor I (406 vs 171 ng/ml), glucose (114 vs 86 mg/dl), insulin (3.9 vs 1.6 ng/ml), and nonesterified fatty acids (NEFA; 135 vs 59 mu Eq/liter). Diurnal patterns of glucose, insulin, and NEFA were also altered in pST-treated pigs. Plasma urea N levels were decreased with pST treatment (9.6 vs 24.0 mg/dl), but the diurnal pattern was unaltered. Our results indicate that the effect of pST is primarily on postabsorptive use of nutrients. In growing pigs, pST exerts a profound effect on N metabolism and on circulating concentrations of hormones and metabolites.     

Surgical management of duodenal obstruction in an adult horse

A 3-year-old Standardbred stallion was admitted for treatment of acute enterocolitis. The horse improved in response to empiric treatment, but subsequently developed ventral edema, scrotal abscessation, and severe laminitis. Improvement again was seen, but on day 29 of hospitalization, the horse developed rapid heart rate and signs of abdominal pain. Exploratory celiotomy revealed complete obstruction of the descending portion of the duodenum, 20 cm caudal to the duodenal sigmoidal flexure. Three-tier duodenojejunostomy and jejunojejunostomy were performed to bypass the duodenal obstruction.