Prevention of air leakage by spraying vivostat fibrin sealant after lung resection in pigs.

STUDY OBJECTIVES: To evaluate Vivostat fibrin sealant in the prevention of air leakage after experimental lung resection in pigs. DESIGN: Randomized study. SETTING: University laboratory. METHODS: Six Landrace pigs were operated on in both lungs through a median sternotomy. Five different resection sites were created in each lung. INTERVENTION: Randomization was performed to either application of Vivostat fibrin sealant (ConvaTec; Skillman NJ) or human albumin 20% (control) at the resection sites. The lung parenchyma was occluded with a soft clamp for either 1, 2, 5, or 10 min in the treatment group and 10 min in the control group. After removal of the clamp, the lung was ventilated with an increasing intrabronchial pressure of 20, 30, and 45 cm H(2)O for 2 min at each step. RESULTS: At inspiratory pressures of 20 and 30 cm H(2)O air leaks were found in the control group but not in the Vivostat group (p < 0.001). At an inspiratory pressure of 45 cm H(2)O, there were two small air leaks in the Vivostat group at each clamping time (four at 5 min), compared with five small and seven large leaks in the control group. Analysis of the data after 10 min of clamping showed that the Vivostat group was superior to the human albumin group (p = 0.002). CONCLUSIONS: This randomized study shows that Vivostat fibrin sealant is effective in preventing air leakage after small lung resections in pigs, even at high inspiratory pressures.

Effects of the angiotensin-converting enzyme inhibitor quinapril on renal function in rats.

Angiotensin-converting enzyme inhibitors induce hypertrophy of renal juxtaglomerular cells in laboratory animals, and, in some studies, also produced renal tubular lesions. The objective of the present study was to evaluate the effects of the new angiotensin-converting enzyme inhibitor quinapril on renal function in normotensive rats. Male rats were dosed orally with quinapril at 0 (vehicle control) or 400 mg/kg for 1, 3, 8, 17 or 29 days. This dose of quinapril is more than 1000-fold greater than the effective antihypertensive dose in rats. Parameters of renal function were measured approximately 24 hours after dosing in order to minimize interference from acute pharmacologically mediated effects. Mean arterial blood pressure was only mildly affected at this time: 126.7 +/- 6.0 and 100.0 +/- 8.7 mm/Hg (mean +/- S.E.; day 29) for the control and quinapril-treated animals, respectively. Microscopic analysis of kidney tissue showed pronounced juxtaglomerular cell hypertrophy and hypergranularity in the quinapril-treated animals. These changes were first observed on day 7 and reached a maximum response by day 14. There were no morphologic changes in renal tubules. Quinapril had no significant effect on serum biochemistry parameters (electrolytes, urea nitrogen, creatinine). Urine output in quinapril-treated animals was increased 65% to 197% over controls during the course of the study and correlated with increased water consumption (r = 0.96). Urine osmolality was reduced 31% to 55% on days 8, 17 and 29. However, except for minimal reductions (< 15%) on day 8, there were no significant effects of quinapril on total (24 hour) urinary excretion of electrolytes or creatinine. There were also minimal effects of quinapril on direct measurements of renal function in anesthetized animals. Mean values (+/- S.E.) for control and quinapril-treated animals on day 29 were, respectively: glomerular filtration rate: 2.93 +/- 0.37 and 2.70 +/- 0.53 ml/min; effective renal plasma flow: 11.14 +/- 2.06 and 11.22 +/- 2.35 ml/min; effective renal tubular secretion: 267 +/- 63 and 261 +/- 106 micrograms/min; filtration fraction: 27.1 +/- 2.5 and 24.0 +/- 0.4%; and fractional sodium excretion: 0.25 +/- 0.04 and 0.34 +/- 0.04%. There were also no significant differences between control and quinapril-treated animals when the above parameters were measured following plasma volume expansion on day 29. The results show that quinapril had no adverse effects on renal function in rats when administered at a suprapharmacological dose for up to 4 weeks.(ABSTRACT TRUNCATED AT 400 WORDS)

Eosinophilic enteritis in a specific-pathogen-free cat.

Moderate to severe, chronic, segmental eosinophilic enteritis was diagnosed histopathologically in a 2-year-old, specific-pathogen-free cat. Peripheral eosinophilia was not observed, although eosinophilic infiltrates were found in mesenteric lymph nodes. Typical gastrointestinal signs characteristic of this disease (diarrhea, vomiting, and anorexia) were not seen; only weight loss was observed. Treatment was not instituted. Previously reported cases of feline eosinophilic enteritis have been associated with several domestic breeds having a diversity of backgrounds. The cat of this report had a known genealogy and disease-free history, was reared under barrier conditions, and was fed a restricted diet. The cause of the disease in this cat was not determined.

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.

A new portacaval shunt.

A new prosthetic, segmented polyether polyurethane portacaval shunt featuring quick-connect anastomotic ends was constructed and evaluated as part of a short-term pharmacokinetic study. The shunts were easily implanted, did not require the use of anticoagulants, and decreased the operative time normally required for this surgical preparation. There was no evidence of thrombosis or venous stasis associated with the shunts.

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.