The clinical efficacy of pentoxifylline and l-glutamine on ischemia and reperfusion injury in cattle with displaced abomasum: a longitudinal study

This study aimed to assess the clinical efficacy of pentoxifylline (PTX) and L-glutamine (L-Gln) treatment on ischemia and reperfusion (I/R) injury in the abomasal tissue, acute phase response (APR), oxidative stress (OS), cytokine response, hemostatic, and coagulation disorders in the 96-h period before and after surgery in displaced abomasum (DA) cases. The study sample consisted of 48 dairy cows with DA that were categorized into four groups as group S (Sham group) (9 Left displaced abomasum (LDA)+3 Right displaced abomasum (RDA), group P (PTX) (10 LDA+2 RDA), group G (L-Gln) (10 LDA+2 RDA), and group P+G (PTX+L-Gln) (10 LDA+2 RDA). Acute-phase protein (Haptoglobin), oxidative stress indicators (malondialdehyde, nitric oxide, and glutathione), cytokines (tumor necrosis factor (TNF)-α and interleukin-1β (IL-1β), coagulation factors (D-Dimer, Antithrombin (ATIII), Thrombin-antithrombin complex, Plasminogen activator inhibitor-1), and enzyme activities (lactate dehydrogenase, gamma- -glutamyl transferase, sorbitol dehydrogenase, glutamate dehydrogenase, adenosine deaminase, myeloperoxidase, and creatine phosphokinase) in blood serum samples and coagulometric analyses of blood plasma were performed in samples taken before the operation and at 30 and 60 min and 2, 5, 10, 24, 48, 72, and 96 h after the operation. In DA cases, while post-operative treatment procedures with PTX and L-Gln were effective in decreasing APR and OS, these were ineffective in prohibiting the inflammatory response coordinated by cytokines. For the treatment and prevention of I/R injury in the DA cases, PTX and L-Gln procedures hold promise with their effects on APR, OS, and hemostatic dysfunction. Additional treatment procedures are required for the suppression of inflammatory response, and the effectiveness of preconditioning treatment may be evaluated.

The evaluation of hemostatic dysfunction and disseminated intravascular coagulation in dairy cows with abomasal displacement

Disseminated intravascular coagulation (DIC) is a complex, dynamic and hemostatic disorder which develops secondarily to a disease characterized with an imbalance in the pro-coagulant and anti-coagulant components of hemostasis. The aim of the study is to evaluate hemostatic dysfunc- tion and the DIC syndrome in cattle with displaced abomasum (DA), with using the hematologic analyses and an extensive coagulation profile in the 96 hour-period including before and after surgery. The animal material of the study consisted of 12 dairy cows diagnosed with displaced abomasum (9 LDA and 3 RDA without volvulus) in the 2-4 week period after parturation and with no other post-partum disease. In dairy cows diagnosed with DA, hematological, coagulomet- ric (PT, APTT, Fibrinogen) and coagulation factor analyses [D-Dimer, TAT (thrombin-anti- thrombin complex), ATIII (antithrombin III), PAI-1 (plazminogen activator inhibitor-1] were performed in blood samples obtained before the operation as well as 30 minutes, 60 minutes and 2, 5, 10, 24, 48, 72 and 96 hours after the operation. In the DA cases, abnormalities were found in 6 of the 8 coagulation parameters. In the LDA and RDA groups, prolonged PT (sec), PT (INR) and APTT, hypofibrinogenemia, an increase in serum D-Dimer concentration at 72 and 96 hours after the operation and an increase in serum ATIII concentrations before and 30, 60 minutes and 2, 5, 72 and 96 hours after the operation was found (p⟨0.05). Hemostatic dysfunction and the risk of DIC developing in DA cases and continuing in the post-operative period was determined.

Plasma and synovial fluid pharmacokinetics of cefquinome following the administration of multiple doses in horses

The plasma and synovial fluid pharmacokinetics and safety of cefquinome, a 2-amino-5-thiazolyl cephalosporin, were determined after multiple intravenous administrations in sixteen healthy horses. Cefquinome was administered to each horse through a slow i.v. injection over 20 min at 1, 2, 4, and 6 mg/kg (n = 4 horses per dose) every 12 h for 7 days (a total of 13 injections). Serial blood and synovial fluid samples were collected during the 12 h after the administration of the first and last doses and were analyzed by a high-performance liquid chromatography assay. The data were evaluated using noncompartmental pharmacokinetic analyses. The estimated plasma pharmacokinetic parameters were compared with the hypothetical minimum inhibitory concentration (MIC) values (0.125-2 μg/mL). The plasma and synovial fluid concentrations and area under the concentration-time curves (AUC) of cefquinome showed a dose-dependent increase. After a first dose of cefquinome, the ranges for the mean plasma half-life values (2.30-2.41 h), the mean residence time (1.77-2.25 h), the systemic clearance (158-241 mL/h/kg), and the volume of distribution at steady-state (355-431 mL/kg) were consistent across dose levels and similar to those observed after multiple doses. Cefquinome did not accumulate after multiple doses. Cefquinome penetrated the synovial fluid with AUC_{synovial fluid} /AUC_plasma ratios ranging from 0.57 to 1.37 after first and thirteenth doses, respectively. Cefquinome is well tolerated, with no adverse effects. The percentage of time for which the plasma concentrations were above the MIC was >45% for bacteria, with MIC values of ≤0.25, ≤0.5, and ≤1 μg/mL after the administration of 1, 2, and 4 or 6 mg/kg doses of CFQ at 12-h intervals, respectively. Further studies are needed to determine the optimal dosage regimes in critically ill patients.

Matrix metalloproteinases 2 and 9 activity in bovine synovial fluids

Matrix metalloproteinases (MMPs) are important enzymes found in connective tissues and thought to be involved in cartilage degradation. They are detectable in bovine synovial fluid and may play a destructive role in bovine septic arthritis. The MMP gelatinase enzymes were detected by gelatin zymography using image analysis of the gels. The active gelatinase levels were determined by a gelatin degradation enzyme-linked immunosorbent assay (ELISA). Increased concentrations of MMP-9 activity were found in the synovial fluids of cows with septic arthritis (P < 0.001) in comparison with fluids from normal joints. Using the gelatin degradation ELISA the net active gelatinases were measured, and significant increases were found in gelatinase bioactivities in synovial fluids from septic joint disease cases (P < 0.001). Increased concentrations of MMP-2 activity were found in the synovial fluids of cows with aseptic arthritis, which appeared to be playing an important role in degradation of articular cartilage in joint disease. This finding required further investigation.

Metalloproteinases in canine experimental traumatic keratoconjunctivitis

Matrix metalloproteinases (MMPs) are thought to be involved in eye disease and may be present in tears. MMP activity was measured by gelatine zymography. Active gelatinase levels were determined by a gelatine degradation ELISA. Potential MMP-9 (gelatinase-B) monomer enzyme activity was elevated (P < 0.001) in keratoconjunctivitis in comparison to normal tears. MMP-9, dimer form, enzyme activity was elevated (P < 0.001) in fluids from keratoconjunctivitis cases in comparison to fluids from normal eyes. Significant increases in gelatinase bioactivities were seen in tears from keratoconjunctivitis disease cases (P < 0.01). Enzymes in dogs with eye disease were biologically active indicating that both the active forms of the enzyme were present. Hence, they could be an important indicator in deterioration of the cornea during eye disease.

Osteocalcin in canine joint diseases

Markers of joint disease are much sought after in human and veterinary rheumatology. This study investigated the relationship between markers of bone and cartilage turnover in sera and synovial fluids in naturally occurring canine joint diseases. Osteocalcin (OC) was measured by radioimmunoassay; enzyme-linked immunosorbent assays were used to measure keratan sulphate, chondroitin sulphate, hyaluronan and antibodies to collagen I and II. Dimethylmethylene blue binding assay was used for the estimation of sulphated glycosaminoglycans. Compared to normal dogs significantly higher serum OC was seen in dogs with osteoarthritis (P < 0.005), rheumatoid arthritis (RA) (P < 0.01) and rupture/stretching of cranial cruciate ligament (P < 0.02). Reduced OC was found in RA synovial fluids but this finding is probably of little value as there was too much overlap with normal joint data. Apart from a weak correlation between synovial fluid OC and keratan sulphate, there were generally no correlations between markers of bone and cartilage turnover probably reflecting the lack of any relationship between bone and cartilage metabolism in most canine arthropathies.

Increased metabolism of collagen VI in canine osteoarthritis

The integrity of joint function depends on both the extracellular matrix and the chondrocytes of articular cartilage. It has been suggested that there is a reciprocal relationship between these two components, which is altered in osteoarthritis. The immunohistochemical distribution of type VI collagen in normal and osteoarthritic canine cartilage was investigated by immunofluorescence and immunoelectron microscopy. Immunogold labelling showed that in normal cartilage type VI collagen was concentrated in the capsule adjacent to the chondrocyte complex. However, in osteoarthritic cartilage, type VI collagen was also observed throughout the cartilage matrix and was greatly increased in the territorial matrix and pericellular capsule surrounding the chondrocytes. Naturally occurring canine osteoarthritis provides a useful model for the study of the human disease, particularly the early stages. The changes in type VI collagen observed in osteoarthritis suggest an attempt at cartilage repair, resulting in the reorganization of the matrix.

Hyaluronan in canine arthropathies

Soluble hyaluronan (HA), which has been considered as a marker for joint disease in man, was measured in serum and synovial fluid (SF) from dogs with osteoarthritis (OA), rheumatoid arthritis (RA), and rupture of the cranial cruciate ligament (CCL) and from normal dogs (control). Dogs with OA and RA had significantly increased serum HA (P < 0.001) and decreased synovial fluid HA (P < 0.001), as did dogs with CCL rupture (serum, P < 0.05; synovial fluid, P < 0.005). In OA, HA was lower in the SF from the affected joint than in that from the clinically normal (inactive) contralateral joint; no such difference was seen in dogs with CCL rupture. Dogs with liver disease (portocaval shunts, viral infectious hepatitis, metastatic neoplasm and disease secondary to diabetes mellitus) had increased serum HA concentrations (P < 0.001). There was a significant overlap of HA values in the diseased and normal dogs. Therefore, it is unlikely that the measurement of this cartilage breakdown product would be of value for diagnosis or prognosis in canine arthropathies.

Measurement of glycosaminoglycans and keratan sulphate in canine arthropathies

Glycosaminoglycans (GAG) and keratan sulphate (KS) were measured in sera and synovial fluids from dogs with either osteoarthritis (OA) or rupture of the cranial cruciate ligament (CCL) and normal dogs. The dogs with OA had higher synovial fluid GAG levels (P < 0.002) and serum KS (P < 0.03) compared to the normal dogs. No significant differences in serum GAG were found in either group. In both OA and rupture of the CCL, GAG levels were increased in the synovial fluid from the affected joint compared with the clinically normal (inactive) contralateral joint. Neither GAG nor KS measurements correlated with serum and synovial fluid antibodies to collagen type II, synovial fluid white cell count or age of dog. It is unlikely that the measurement of these cartilage breakdown products is of value for diagnostic or prognostic use in canine arthropathies.