Perspectives on implementing veterinary clinical studies committees.

To address the limitations of traditional IACUC review of clinical research studies involving client-owned animals, the AVMA issued a policy describing the use of a veterinary clinical studies committee (VCSC), analogous to an institutional review board, as a way to ensure the adequate review and oversight of such studies. While IACUC composition, review, approval processes, and responsibilities are well established, uniform guidance for VCSCs is not readily available and not included in the guidance for IACUCs. In this manuscript we describe suggested best practices for scientific and ethical review of veterinary clinical research studies, regardless of the specific research setting.

CLP-induced impairment of innate immune function is caused by exposure to the cecal lumenal contents and not the tissue trauma or tissue ischemia/necrosis components.

When mice are subjected to a Pseudomonas aeruginosa challenge 5 days after cecal ligation and puncture (CLP), clearance of the Pseudomonas is diminished when compared to sham mice. The object of this study was to determine which component(s) of CLP contributed to the impairment of the innate immune response. Mice subjected to either trauma alone or cecal ischemia/necrosis alone did not have impaired ability to clear a subsequent Pseudomonas challenge (determined by colony-forming units (cfu's) after culture of spleen tissue).

Cecal ligation and puncture-induced impairment of innate immune function does not occur in the absence of caspase-1.

Mice that have been subjected to cecal ligation and puncture (CLP) have an impaired ability to clear a subsequent Pseudomonas aeruginosa challenge compared with that of sham CLP controls. We hypothesized that this outcome is dependent upon a caspase-1 mechanism and tested this hypothesis by measuring caspase-1 after CLP and by measuring clearance of a bacterial challenge in caspase-1-deficient mice after CLP. Wild-type mice subjected to CLP had increased caspase-1 activity as well as increased IL-1β and increased IL-18 production in splenocytes stimulated with heat-killed Pseudomonas and had increased plasma concentrations of IL-1β and IL-18 and impaired clearance of a P.

The role of interferon-γ in the pathogenesis of acute intra-abdominal sepsis.

Several studies indicate that IFN-γ facilitates systemic inflammation during endotoxin-induced shock. However, the pathobiology of IFN-γ in clinically relevant models of septic shock, such as CLP, is not well understood. In this study, the role of IFN-γ in the pathogenesis of CLP-induced septic shock was evaluated by examining IFN-γ production at the tissue and cellular levels.

Pretreatment with the Gram-positive bacterial cell wall molecule peptidoglycan improves bacterial clearance and decreases inflammation and mortality in mice challenged with Staphylococcus aureus.

Objective: To determine whether tolerance and enhancement of innate immune function can be induced by the Gram-positive cell wall component peptidoglycan.

Design: Controlled, in vivo laboratory study.

Subjects: Male mice, 8-12 wks (C57BL6/J; C3H/HeJ; B6.

Pretreatment with the Gram-positive bacterial cell wall molecule peptidoglycan improves bacterial clearance and decreases inflammation and mortality in mice challenged with Pseudomonas aeruginosa.

The objective of this study was to determine if inflammatory tolerance and enhancement of innate immune function could be induced by the Gram-positive cell wall component peptidoglycan (PGN). Male mice (C57BL6/J or C3H/HeJ, 8-12 weeks of age) were given intraperitoneal injections of 1mg PGN on 2 consecutive days. The mice were then challenged with lipopolysaccharide (LPS) or live Pseudomonas aeruginosa (1 x 10(8) colony-forming units) 2 days after the second pretreatment.

Endotoxin pretreatment improves bacterial clearance and decreases mortality in mice challenged with Staphylococcus aureus.

We studied the effects of tolerance induced by Escherichia coli-derived LPS on the innate immune response to a subsequent Staphylococcus aureus bacterial challenge. LPS tolerance was induced in wild-type mice by either intraperitoneal or intravenous injection of 2 microg of LPS on 2 consecutive days. Mice were challenged with an intravenous injection of live S.

Mice depleted of alphabeta but not gammadelta T cells are resistant to mortality caused by cecal ligation and puncture.

The present study was undertaken to determine whether the mice depleted of alphabeta or gammadelta T cells show resistance to acute polymicrobial sepsis caused by cecal ligation and puncture (CLP). T-cell receptor beta knockout (betaTCRKO) and T-cell receptor delta knockout (deltaTCRKO) mice were used. An additional group of mice was treated with an antibody against the alphabeta T-cell receptor to induce alphabeta T-cell depletion; a subset of alphabeta T cell-deficient mice was also treated with anti-asialoGM1 to deplete natural killer (NK) cells.

Improved bacterial clearance and decreased mortality can be induced by LPS tolerance and is not dependent upon IFN-gamma.

Endotoxin (LPS) tolerance is induced by exposure to sublethal doses of LPS, resulting in a suppressed proinflammatory response and an improved survival rate after challenge with a normally lethal dose of LPS. We studied the effects of tolerance induced by either Escherichia coli-derived LPS or Pseudomonas aeruginosa-derived LPS on the innate immune response to a subsequent P. aeruginosa bacterial challenge and determined if the induction of tolerance was dependent on interferon gamma (IFN-gamma) activity.

Are feeding practices associated with duodenitis-proximal jejunitis?

Reasons For Performing Study: Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study.

Objectives: To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study.

Hypothesis: The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic.

Effect of transforming growth factor-beta neutralization on survival and bacterial clearance in a murine model of Pseudomonas aeruginosa burn wound infection.

Transforming growth factor-beta (TGF-beta), a cytokine with anti-inflammatory properties, may contribute to postburn immunosuppression. This study was designed to determine whether neutralizing TGF-beta in burned mice could improve resistance to infection. C57BL/6J mice received a 35% TBSA flame burn under isoflurane anesthesia.

Bacterial clearance and mortality are not improved by a combination of IL-10 neutralization and IFN-gamma administration in a murine model of post-CLP immunosuppression.

Immunocompromise after a major injury is presumed to be a predisposing factor for sepsis. Mice subjected to sublethal cecal ligation and puncture (CLP) and challenged 5 days later with Pseudomonas aeruginosa had more bacterial growth in lung tissue, lower serum interferon gamma (IFN-gamma) and interleukin (IL) 12,and higher serum IL-10 when compared with sham CLP mice challenged with Pseudomonas. To test the functional significance of these alterations in cytokine production in the immune response to bacteria, we administered IFN-gamma and anti-IL-10 to post-CLP mice before the Pseudomonas challenge.

Endotoxin priming improves clearance of Pseudomonas aeruginosa in wild-type and interleukin-10 knockout mice.

Endotoxin (lipopolysaccharide [LPS]) tolerance is an altered state of immunity caused by prior exposure to LPS, in which production of many cytokines, including gamma interferon (IFN-gamma) and interleukin-12 (IL-12), are reduced but secretion of the anti-inflammatory cytokine IL-10 is increased in response to a subsequent LPS challenge. This pattern of cytokine production is also characteristic of postinflammatory immunosuppression. Therefore, we hypothesized that LPS-primed mice would exhibit an impaired ability to respond to systemic infection with the opportunistic pathogen Pseudomonas aeruginosa.

Glucan phosphate treatment attenuates burn-induced inflammation and improves resistance to Pseudomonas aeruginosa burn wound infection.

These studies evaluated the effects treatment with glucan phosphate, a soluble polysaccharide immunomodulator, on the inflammatory response induced by burn injury and on resistance to Pseudomonas aeruginosa burn wound infection. Mice were exposed to 35% total body surface area burns and were resuscitated with lactated Ringer's (LR) solution alone or LR supplemented with glucan phosphate (40 mg/kg). Glucan phosphate treatment attenuated burn-induced expression of interleukin (IL)-1beta, IL-6, and IL-10 mRNAs in spleen, lung, and heart.

Enhancement of dendritic cell production by fms-like tyrosine kinase-3 ligand increases the resistance of mice to a burn wound infection.

Fms-like tyrosine kinase-3 ligand (Flt3L) is a hemopoietic cytokine that stimulates the production of dendritic cells. This study evaluated the ability of Flt3L-enhanced dendritic cell production to increase the resistance of mice to a burn wound infection with Pseudomonas aeruginosa, a common source of infections in burn patients that have impaired immunity and are susceptible to opportunistic microorganisms. Treatment of mice with Flt3L for 5 days caused a significant increase in dendritic cell numbers in the spleen and significantly increased survival upon a subsequent burn wound infection.

Gamma interferon does not enhance clearance of Pseudomonas aeruginosa but does amplify a proinflammatory response in a murine model of postseptic immunosuppression.

Patients that have suffered a major injury may sustain a period of immunocompromise and altered Th1/Th2 cytokine balance that can predispose them to opportunistic infections. Pseudomonas aeruginosa is frequently a causative organism for nosocomial infections in critically ill patients and is associated with high mortality. We previously mimicked this clinical scenario by challenging mice with P.

Mice depleted of CD8+ T and NK cells are resistant to injury caused by cecal ligation and puncture.

We previously showed that beta 2 microglobulin knockout mice depleted of NK cells by treatment with anti-asialoGM1 (beta2MKO/alphaAsGM1 mice) are resistant to sepsis caused by cecal ligation and puncture (CLP). beta2MKO mice possess multiple immunological defects including depletion of CD8+ T cells. This study was designed to determine the contribution of CD8+ T and NK cell deficiency to the resistance of beta2MKO/alphaAsGM1 mice to CLP-induced injury.

Diminished bacterial clearance is associated with decreased IL-12 and interferon-gamma production but a sustained proinflammatory response in a murine model of postseptic immunosuppression.

After a major illness or injury, immune status in critically ill patients may fluctuate between a marked proinflammatory response and an immunosuppressed state. Postinflammatory immunosuppression can result in increased susceptibility to infection. Alterations of cytokine production, such as suppression of IFNgamma and elevation of the anti-inflammatory cytokine IL-10, are believed to contribute to postinflammatory immunosuppression.

Protective effect of tumor necrosis factor-alpha against subsequent endotoxemia in mice is mediated, in part, by interleukin-10.

Objective: Tumor necrosis factor (TNF)-alpha administration in large amounts can induce a state of shock similar to that observed in patients suffering from septic shock. Small doses of TNF-alpha induce only mild, transient hemodynamic alterations and can confer protection against subsequent inflammatory stimuli. The objective of this study was to determine whether this protective mechanism could be attributed to activity of the anti-inflammatory cytokine interleukin (IL)-10.

Up-regulation of the parathyroid calcium-sensing receptor after burn injury in sheep: a potential contributory factor to postburn hypocalcemia.

Objective: To test the hypothesis that the hypocalcemia and hypoparathyroidism that follow severe burn injury are related to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), which may reduce the set-point for suppression of circulating parathyroid hormone by blood calcium.

Design: A controlled but unblinded study.

Setting: An investigational intensive care unit.

Pretreatment with tumor necrosis factor-alpha attenuates arterial hypotension and mortality induced by endotoxin in pigs.

Objective: Tumor necrosis factor (TNF)-alpha administration in large amounts can induce a state of shock similar to that seen during severe sepsis. The objective of this study was to determine whether small doses of TNF-alpha might decrease the disposition for the development of shock induced by a subsequent infusion of endotoxin and to determine whether the mechanism of this protective effect of TNF-alpha pretreatment could be associated with up-regulation of the anti-inflammatory cytokine interleukin (IL)-10.

Design: Prospective, randomized, experimental study.

Long-term outcome of horses with a slab fracture of the central or third tarsal bone treated conservatively: 25 cases (1976-1993).

Objective: To determine clinical features of horses with a slab fracture of the central or third tarsal bone and to report outcome of horses in which treatment did not include surgery.

Design: Retrospective study.

Animals: 25 horses (14 Standardbreds, 6 Thoroughbreds, 5 Quarter Horses).

Cardiopulmonary and splanchnic blood flow during 48 hours of a continuous infusion of endotoxin in conscious pigs: a model of hyperdynamic shock.

Hyperdynamic shock can be modeled in pigs by chronic administration of a continuous, low-dose infusion of endotoxin. Lipopolysaccharide (LPS, E. coli 0111:B4, 80 ng/kg/min i.

Lung surfactant kinetics in conscious pigs.

The primary goal of this study was to determine the contributions of plasma free fatty acids (FFA) and de novo synthesized fatty acids (FA) to lung surfactant phosphatidylcholine (PC) synthesis. A new stable isotope tracer model was developed in which [1, 2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in nine normal overnight fasted pigs to quantify surfactant kinetics in the basal state and during low-dose glucose infusion (2 mg. kg(-1).