Comparison of antibody response by use of synthetic adjuvant system and Freund complete adjuvant in rabbits.

Two commercially available synthetic adjuvant systems, trehalose dimycolate (TDM) and TDM + monophosphoryl lipid A (MPL), were compared with Freund complete adjuvant (FCA) for the ability to stimulate antibody production in New Zealand White rabbits (Oryctolagus cuniculus). In addition, each animal was evaluated for adverse reactions. The antigen, rat liver microsomal epoxide hydrolase, was administered SC emulsified with FCA, TDM, or TDM + MPL. Serum antibody titers were stimulated with all 3 adjuvant-antigen combinations. The highest titer was produced by use of FCA; TDM + MPL produced an intermediate response, and TDM produced the lowest titer. All of the rabbits immunized with FCA developed sterile subcutaneous abscesses. Rabbits immunized with TDM or TDM + MPL developed no abscesses, and only slight reactions at the injection site. The synthetic adjuvant system TDM + MPL is recommended for use in rabbits, considering its adequate stimulation of antibody production with minimal adverse reactions.

Production of methylguanidine in dogs with acute and chronic renal failure.

1. Methylguanidine is a suspected uraemic toxin that accumulates in renal failure. 2. We measured methylguanidine in the plasma of dogs with acute ischaemic-induced renal failure and in the plasma and urine of dogs with spontaneous chronic renal insufficiency, using a highly sensitive method involving solid-phase extraction followed by h.p.l.c. with post-column fluorescence detection. 3. Constriction of the remaining renal artery of four uninephrectomized dogs for 90 min resulted in a significant (P less than 0.01) increase in plasma creatinine concentration after 24 h (from 113 +/- 3 to 303 +/- 50 mumol/l; mean +/- SEM). Over the next 14 days, plasma creatinine fell towards baseline concentrations. Plasma methylguanidine also increased significantly (P less than 0.05) 24 h after renal occlusion (from 0.16 +/- 0.04 to 0.86 +/- 0.32 mumol/l) and showed a similar pattern to the plasma creatinine concentration. 4. In a further four dogs, administration of mannitol (2 g/kg) at the time of reperfusion significantly attenuated these responses. 5. Dogs with chronic renal failure demonstrated increased plasma concentrations and urinary excretion of methylguanidine, and the levels appeared to be related to the severity of renal insufficiency. Thus, the dogs with the highest plasma creatinine concentrations and lowest creatinine clearances had the highest plasma methylguanidine concentrations. The clearance of methylguanidine exceeded that of creatinine, indicating that the toxin undergoes renal tubular secretion.

Some effects of limited exercise on purpose-bred beagles.

Amendments to the Animal Welfare Act (PL 99-198) require that an exercise program for dogs be established by the attending veterinarian. A 6-week study was conducted to determine the effects of a moderate exercise program in purpose-bred Beagles. Sixteen male Beagles (4/group) were maintained as follows: (1) standard cage without exercise; (2) standard cage with individual exercise periods (35 minutes, 3 times/week); (3) large cage without exercise; and (4) standard cage with group-release exercise periods. Blood samples were collected for CBC, serum biochemical analysis including determination of serum cortisol concentration, and immune function (lymphocyte transformation assay). Group-released dogs interacted with each other during most of the exercise time. Fighting in these dogs occurred only during the third week. Dogs had little inclination to exercise when released alone into the exercise area. Regardless of the size of the cage, dogs did not exercise unless human beings were present in the room. There were no significant differences in laboratory findings among dogs in the 4 groups. This moderate exercise program had no demonstrable effects. Similarly, continuous cage housing, without a formal exercise program, could not be determined to be detrimental to the physiologic or health status of dogs.