TF-TEG using the described protocol may minimize variability in data obtained across institutions or users. However, due to the variability associated with different operators, it is recommended that each laboratory set up individual reference intervals with the personnel who will perform the assay, and that the assay protocols and data obtained are compared on a regular basis.

Although the basis for the high mortality rate for patients with mixed bacterial infections is likely to be multifactorial, there is evidence for a synergistic effect of muramyldipeptide (MDP) with lipopolysaccharide (LPS) on the synthesis of proinflammatory cytokines by mononuclear phagocytes. In this study, co-incubation of human Mono Mac 6 cells with MDP and either LPS or peptidoglycan (PGN) resulted in an apparent synergistic effect on tumor necrosis factor-␣ (TNF-␣) secretion. Although incubation of cells with MDP alone produced minimal TNF-␣, it caused significant expression of TNF-␣ mRNA. These findings suggest that the majority of TNF-␣ mRNA induced by MDP alone is not translated into protein. Furthermore, simultaneous incubation of cells with MDP and either LPS or PGN resulted in TNF-␣ mRNA expression that approximated the sum of the amounts expressed in response to MDP, LPS, and PGN individually. These findings indicate that the apparent synergistic effect of MDP on TNF-␣ production induced by either LPS or PGN is due to removal of a block in translation of the mRNA expressed in response to MDP. In subsequent studies, the effects of MDP alone and its effect on the production of TNF-␣ by LPS and PGN were determined to be independent of CD14, Toll-like receptor 2, and Toll-like receptor 4. These findings indicate that MDP acts through receptor(s) other than those primarily responsible for transducing the effects of LPS and PGN. Successful treatment of patients having mixed bacterial infections is likely to require interventions that address the mechanisms involved in responses induced by a variety of bacterial cell wall components.Bacteremia is a critical problem in intensive care units, accounting for high morbidity and mortality rates. The mortality rate associated with bacteremia exceeds 30% (1, 2). In a recent 12-year clinical study, Gram-positive and Gram-negative bacteria accounted for 46.9 and 31.5% of bacteremic episodes in an intensive care unit, respectively, with Gram-positive organisms being cultured from more patients (3). Further, the incidence of combined infections increased more than 4-fold over the 12-year period and was associated with a mortality rate exceeding 55%. Based on the fact that the majority of the deleterious effects of bacteremia are caused by inflammatory responses to specific bacterial components, these findings suggest that the patient's response to a mixture of Gram-positive and Gram-negative organisms may be heightened to the detriment of the patient.The two most commonly studied components of Gram-positive and Gram-negative bacterial cell walls are peptidoglycan (PGN) 1 and lipopolysaccharide (LPS), respectively. Although Gram-negative bacterial cell walls also contain PGN, its concentration is far greater in the walls of Gram-positive bacteria (4). Proinflammatory effects of these bacterial cell wall components occur both in vitro after treatment of mononuclear phagocytes and in in vivo after exposure of whole animals, with cells and animals being more sensitive to ...

Although studies have been performed to characterize responses of macrophages from individual anatomical sites (e.g., alveolar macrophages) or of murine-derived macrophage cell lines to microbial ligands, few studies compare these cell types in terms of phenotype and function. We directly compared the expression of cell surface markers and functional responses of primary cultures of three commonly used cells of monocyte-macrophage lineage (splenic macrophages, bone-marrow derived macrophages, and bone-marrow derived dendritic cells) with those of the murine-leukemic monocyte-macrophage cell line, RAW 264.7. We hypothesized that RAW 264.7 cells and primary bone marrow-derived macrophages would be similar in phenotype and would respond similarly to microbial ligands that bind to either Toll-like receptors 2, 3, and 4. Results indicate that RAW 264.7 cells most closely mimic bone marrow-derived macrophages in terms of cell surface receptors and response to microbial ligands that initiate cellular activation via Tolllike receptors 3 and 4. However, caution must be applied when extrapolating findings obtained with RAW 264.7 cells to those of other primary macrophage-lineage cells, primarily because phenotype and function of the former cells may change with continuous culture.

SUMMARY Caecal fluid samples collected 8 and 24 hours after carbohydrate overload were quantitatively compared to control samples in terms of aerobic and anaerobic bacteria. Concomitant increases in lactic acid‐producing bacteria and decreases in Gram negative bacteria were substantiated during the onset of acute laminitis. Progressive decreases in caecal fluid pH were also quantitated. Although endotoxin assays of caecal fluid and blood were not done, the caecal flora changes suggest its presence during the onset of acute laminitis. RÉSUMÉ Des échantillons de fluide coecal recueillis 8 et 24 heures apràs une surcharge digestive en hydrates de carbone furent comparés à des échantillons témoins pour apprécier les modifications de la flore aérobie et anaérobie. On constata une augmentation des bactéries productrices d'acide lactique et une diminution des bactéries Gram—avec installation des signes de fourbure aigue. Une diminution progressive du Ph du liquide coecal fut également remarquée. On ne contrôla point la présence d'antoxines dans le liquide coecal ni dans le sang. Mais les variations de la flore coecale laissent penser à l'existence de telles toxines au début de la fourbure aigue. ZUSAMMENFASSUNG Blinddarminhalt wurde 8 und 24 Stunden nach Kohlenhydratüberfütterung entnommen und quantitativ verglichen mit Kontrollproben (Zahl der aeroben und anaeroben Bakterien). Beim Eintritt einer akuten Hufrehe kommt es gleichzeitig zu einer Vermehrung von Lactat‐produzierenden Bakterien und zu einer Verminderung von Gram‐negativen Keimen. Ein zunehmender Abfall des pH im Blindarminhalt konnte ebenfalls quantitativ erhärtet werden. Obgleich Endotoxinbestimmungen in der Blinddarmflüssigkeit und im Blut nicht vorgenommen werden konnten, kann das Vorhandensein von Endotoxin aufgrund der Veränderungen der Flora beim Eintritt einer akuten Rehe vermutet werden.

Background: Coagulopathies in horses with gastrointestinal disease are frequently identified and associated with morbidity and fatality.Objective: Determine if thrombelastography (TEG) identifies abnormalities associated with lesion type, presence of systemic inflammatory response syndrome (SIRS), morbidity, and fatality more consistently than traditional coagulation testing.Animals: One-hundred and one horses examined for gastrointestinal disease and 20 healthy horses. Methods: TEG, tissue factor (TF)-TEG, and traditional coagulation panels parameters and percentages of horses with coagulopathies were compared for lesion type, presence of SIRS, complications, and survival.Results: Changes in individual parameters and increased incidence of coagulopathies were associated with fatality (R, P 5 .007; k-value [K], P 5 .004; clot lysis [CL]30, P 5 .037; CL60, P 5 .050; angle [Ang], P 5 .0003; maximum amplitude [MA], P 5 .006; lysis [Ly]30, P 5 .042; Ly60, P 5 .027; CI, P 5 .0004; ! 2 TEG coagulopathies, P 5 .013; ! 3 TEG coagulopathies, P 5 .038; TF-R, P 5 .037; TF-K, P 5 .004; TF-CL30, P o .0001; TF-CL60, P o .0001; TF-Ang, P 5 .005; TF-Ly30, P 5 .0002; TF-Ly60, P o .0001; TF-CI, P 5 .043; ! 1 TF-TEG coagulopathies, P 5 .003; ! 2 TF-TEG coagulopathies, P 5 .0004; prothrombin tme [PT], P o .0001; activated partial throboplastin time [aPTT], P 5 .021), inflammatory lesions (MA, P 5 .013; TF-CL30, P 5 .033; TF-CL60, P 5 .010; TF-Ly60, P 5 .011; ! 1 TF-TEG coagulopathy, P 5 .036; ! 2 TF-TEG coagulopathy, P 5 .0007; PT, P 5 .0005; fibrinogen, P 5 .019), SIRS (MA, P 5 .004; TF-CL30, P 5 .019; TF-CL60, P 5 .013; TF-Ly30, P 5 .020; TF-Ly60, P 5 .010; PT, P o .0001; aPTT, P 5 .032; disseminated intravascular coagulation, P 5 .005), and complications (ileus: aPTT, P 5 .020; diarrhea: TF-CL30, P 5 .040; TF-Ly30, P 5 .041; thrombophlebitis: ! 1 TF-TEG coagulopathy, P 5 .018; laminitis: MA, P 5 .004; CL60, P 5 .045; CI, P 5 .036; TF-MA, P 5 .019; TF-TEG CI, P 5 .019). Abnormalities in TEG and TF-TEG parameters were indicative of hypocoagulation and hypofibrinolysis.Conclusions and Clinical Importance: TEG identifies changes in coagulation and fibrinolysis associated with lesion type, SIRS, morbidity, and fatality in horses with gastrointestinal disease.

SUMMARY Blood lactate levels were evaluated in 36 horses (43 cases) presented with colic. A correlation between increasing blood lactate levels and decreasing percentage survival has been shown. An appreciable anion gap was found in 7 of 10 cases analyzed in detail but in each case the entire gap could not be accounted for by lactate alone. Proposals are offered to account for the unmeasured anions. Blood lactate determination is suggested as a prognostic rather than a diagnostic aid for the equine practitioner and should be used to augment other clinical findings in the horse exhibiting colic. RÉSUMÉ On a évalué le taux du lactate dans le sang de 36 chevaux (43 cas) atteints de coliques. On a établi une correlation entre les taux de lactate sanguin accrus et le pourcentage décroissant de survie. Dans 7 des 10 cas analysés en détail, on a constaté une appréciable déficience des anions; toutefois l'augmentation des lactates n'était pas responsable entièrement. La détermination du taux de lactate semble avoir en pratique une valeur plus pronostique que diagnostique et constitue un élement clinique complémentaire. ZUSAMMENFASSUNG Blut‐Laktatspiegel wurden bei 36 Pferden (43 Fälle) mit Kolik untersucht. Es konnte eine Beziehung zwischen ansteigenden Laktatwerten und abnehmender Ueberlebenschance hergestellt werden. Eine bedeutende Anionenlücke bestand in 7 von 10 genauer untersuchten Fällen, aber sie konnte nicht dem Laktat allein zugeschrieben werden. Ueber die Natur der ungemessenen Anionen werden Vermutungen angestellt. Die Blut‐Laktatbestimmungen werden eher als prognostisches denn als diagnostisches Hilfsmittel für den Praktiker angesehen; sie sollten beim Kolikpatienten durchgeführt werden zur Bereicherung der klinischen Befunde.

One hundred thirteen of 172 horses (66%) undergoing exploratory celiotomy for a small intestinal lesion survived 4 or more days after surgery. Intra-abdominal adhesions causing clinical problems requiring additional surgery or euthanasia were documented in 25 horses (22.1%). Problems developed in significantly more males than females. The most common initial small bowel lesion was ileal impaction (12 horses); 21 horses underwent small intestinal resection or bypass. However, there was no significant difference in the incidence of intra-abdominal adhesions between horses that underwent intestinal resection or bypass and those that did not. Only 4 of the 25 horses (16%) with problems associated with postoperative adhesions survived. The mean interval between surgical procedures or between the initial procedure and euthanasia for all horses was 84 days (range, 7-512 days; median, 25 days). However, 70% of the subsequent celiotomies were performed within 60 days of the previous surgery. The mean interval between celiotomies was 221 days (range, 9-512 days) for the survivors and 61 days (range, 7-358 days) for the nonsurvivors. These results indicated that most of the problems related to postoperative intra-abdominal adhesions occurred within 2 months of the initial small intestinal surgery. Furthermore, the earlier development of postoperative adhesions was associated with a poorer prognosis for survival.

Results suggest that IL-1beta mRNA is expressed by perivascular cells in the laminar tissues of horses in the prodromal stage of experimentally induced laminitis. This provides evidence of an inflammatory process during the prodromal stage of laminitis, indicating that local digital proinflammatory cytokine expression may be an initiating factor in laminitis.