Biochemical assessment of canine body cavity effusions using three bench-top analysers.

OBJECTIVES: To assess the performance of three bench-top chemistry instruments for the analysis of canine effusions. Acceptable results were compared with those obtained by a reference chemistry analyser. METHODS: Total protein, albumin, creatinine and bilirubin concentrations were measured in 74 effusions using the VetScanVS2, VetTest8008 and SpotchemEZ analysers. Cholesterol and triglyceride concentrations were also measured by the VetTest and Spotchem. Results were analysed using Westgard's error analysis, Spearman's correlation, Bland-Altman plots and Deming regression. Results were considered acceptable when observed total error (TE(obs) ) was less than allowable total error (TE(A) ). RESULTS: VetScan error analysis revealed acceptable results for total protein (TE(obs) =1.11, TE(A) =4.7) and creatinine (TE(obs) =42.2, TE(A) =78.1). Correlation was fair for protein (r(s) =0.66) and creatinine (r(s) =0.76), but poor and not significant for bilirubin (r(s) =0.01, P=0.08), precluding error analysis. VetTest error analysis was acceptable for creatinine only (TE(obs) =5.55, TE(A) =25.5). Correlation was good (r(s) =0.81). The difference plot revealed a bias (95% confidence interval) of -1.5 (-37 to 40) and four outliers. The Spotchem did not generate a precise arithmetic value in most (56.9 to 73.6%) samples, precluding further analysis. CLINICAL SIGNIFICANCE: Acceptable results were obtained for total protein (VetScan) and creatinine [Vetscan, Vettest (with good correlation)]. The Spotchem is of limited value in canine effusion analysis.

Prevalence and diagnosis of parasites of the stomach and small intestine in horses in south-west England.

Parasites were extracted from the stomach and small intestine of 118 horses at slaughter. The most abundant species was the tapeworm Anoplocephala perfoliata. Maximum likelihood analysis was used to investigate the relationship between the number of worms and their total weight, and the ability of an antibody-based elisa to diagnose the level of infection. The total weight of tapeworms increased towards a maximum as the number of worms increased, suggesting a population density-dependent constraint on the weight. The number of A perfoliata present could be predicted approximately from the results of the elisa. Although wide variation in elisa optical densities confound interpretation in individual animals, tests on groups of animals could provide a useful reflection of overall levels of infection.

Expression of the calcium binding protein calretinin in WiDr cells and its correlation to their cell cycle.

Ca2+ ions intervene during different phases of the progression of the cell cycle, but only one calcium-binding protein, calmodulin, has been shown to be associated with dividing cells. We therefore screened cancer cells for the presence of other related calcium-binding proteins. Using molecular biological and immunohistochemical techniques we show that human tumor cells of epithelial origin, express calretinin. Calretinin immunoreactivity can be demonstrated at precise moments of the cell cycle and, in particular, in phase G1 and during mitosis. During mitosis calretinin is localized both in the cytoplasm and in the mitotic spindle. In the cytoplasm we find calretinin after prophase and until telophase. In the spindle apparatus, calretinin is already present in cells in prometaphase and persists in all the succeeding mitotic phases. It is associated with the kinetochore microtubules but, in contrast to calmodulin, also with the polar microtubules. The role that calretinin plays in well-defined moments of the cell cycle of these cells is as yet unknown, but our results strongly suggest that, in collaboration with other molecules, calretinin intervenes in the dynamic phenomena regulating the separation of the chromosomes.

Clearance of a novel recombinant tissue plasminogen activator in rabbits.

The pharmacokinetic properties of hPA(B), characterized by the insertion of a urokinase kringle coding region before the double kringle of tPA plus the complete tPA coding region, were investigated and compared to those of melanoma tPA (mtPA). Mean peak plasma concentrations at the end of infusion were 4.7 micrograms/ml for hPA(B) and 4.6 micrograms/ml for mtPA. The pharmacokinetics of both hPA(B) and mtPA showed a biexponential disappearance from plasma which is consistent with a two-compartment model of t 1/2 (lambda 1) = 2 minutes, t 1/2 (lambda 2) = 58 minutes for hPA(B), and t 1/2 (lambda 1) = 2.2 minutes, t 1/2 (lambda 2) = 61 minutes for mtPA. However, this very fast decaying lambda 1 phase of mtPA lasted five times longer than that of hPA(B) which resulted in very low concentrations of mtPA. Thus, hPA(B) exhibited larger AUC, slower clearance rate, and smaller volume of distribution (P less than 0.01) than those of mtPA. The fibrinolytic activity of hPA(B) in rabbit plasma as determined by zymography lasted up to 120 minutes after the end of infusion as compared to that of 2 minutes for mtPA. This indicates that mtPA, despite its t 1/2 (lambda 2) being similar to that of hPA(B), is no longer at physiologically meaningful concentrations at the start of the lambda 2 phase.

Disposition of a novel recombinant tissue plasminogen activator, delta 2-89 TPA, in mice.

The pharmacokinetic characteristics of delta 2-89 tPA, characterized by the deletion of the first 89 amino acids at the NH2-terminus of tPA, were evaluated and compared to those of recombinant tPA (rtPA). When they were administered intravenously to mice, a biexponential disposition curve was observed for both tPAs. The plasma half-lives of lambda 1 and lambda 2 phases of delta 2-89 tPA were 15 minutes and 180 minutes which are significantly higher than those of rtPA. A zymogram of mouse plasma taken at various time intervals showed that delta 2-89 tPA retained fibrinolytic activity up to 30 minutes, whereas rtPA could be detected only up to 5 minutes after injection. Autoradiography revealed that most of 125I-delta 2-89 tPA was associated with plasma protein complex.

Therapeutic efficacy of cefpiramide-ciprofloxacin combination in experimental Pseudomonas infections in neutropenic mice.

The therapeutic efficacy of cefpiramide and ciprofloxacin alone and in combination was investigated and compared with that of ticarcillin plus tobramycin against pseudomonal infections in mice made neutropenic by administration of cyclosphosphamide. Therapy with cefpiramide plus ciprofloxacin was significantly more effective than that by either antibiotic alone. These results were consistent with in-vitro synergistic effects. At a higher dose of ciprofloxacin (4 mg/kg) plus cefpiramide (50 mg/kg), the combination therapy protected all neutropenic mice from fatal bacteraemia, and was more protective than ticarcillin (200 mg/kg) plus tobramycin (1 mg/kg). The peak serum concentration of cefpiramide in infected neutropenic mice was 51 mg/l when they were given 50 mg/kg subcutaneously. Ciprofloxacin attained a peak serum concentration of 1.2 mg/l and a serum half-life of 34 min.

Synergistic activity of apalcillin and gentamicin in a combination therapy in experimental Pseudomonas bacteraemia of neutropenic mice.

The therapeutic activity of a combination of apalcillin and gentamicin was evaluated in experimental Pseudomonas aeruginosa infection in neutropenic mice. Mice made neutropenic by administration of cyclophosphamide were more susceptible to P. aeruginosa infection than normal mice. At both challenge levels of 2LD50 and 20LD50, therapy with gentamicin alone was more effective than that with apalcillin or piperacillin. However, therapy with apalcillin-gentamicin combinations was significantly more effective than that by either component alone, and was as active as that with piperacillin-gentamicin. These in-vivo findings correlated with those of in-vitro studies, thus establishing a synergistic effect when apalcillin and gentamicin were combined. The results show that apalcillin when combined with gentamicin is effective in treating serious P. aeruginosa bacteraemia in neutropenic mice.

Therapeutic efficacy of cefpiramide and cefoperazone alone and in combination with gentamicin against pseudomonal infections in neutropenic mice.

Cefpiramide and cefoperazone alone and in combination with gentamicin were compared for therapeutic efficacy against pseudomonal infections in normal mice and in mice made neutropenic by administration of cyclophosphamide. Neutropenic mice were more susceptible to infection with Pseudomonas aeruginosa than normal mice. At all challenge doses, combination therapy with either cefpiramide-gentamicin or cefoperazone-gentamicin was more effective than that with a single agent. Therapy with the cefpiramide-gentamicin combination was significantly more active than that with the cefoperazone-gentamicin combination in protecting mice from fatal bacteremia. Pharmacokinetic studies in mice showed that cefpiramide attained a peak serum concentration of 12 micrograms/ml and a serum half-life of 40 min, which are higher than attained by cefoperazone with values of 4 micrograms/ml and 18 min. These factors may have caused the combined cefpiramide-gentamicin therapy to result in significantly improved survival rates in mice as well as in higher bactericidal titers than the cefoperazone-gentamicin combination. The results show that cefpiramide when combined with gentamicin is effective in treating serious infections with P. aeruginosa in neutropenic mice.