Use of polypentapeptides of elastin to prevent postoperative adhesions: efficacy in a contaminated peritoneal model.

We investigated the use of a sheet of polypentapeptide of elastin as a physical barrier to adhesion formation in a contaminated peritoneal wound model. A total of 88 rats were studied with random assignment of animals to three study groups; control (29), polypentapeptide steam sterilized (30), and polypentapeptide gas sterilized (29). Animals were anesthetized and a laparotomy was conducted to reveal the cranial portion of the ileum. The abdominal wall muscle peritoneum was excoriated until hemorrhage was noted. In sham animals, there was no physical barrier placed between bowel loop and the abdominal wall. In two of the study groups, the polypentapeptide sheet was placed directly over the excoriated area. The intestinal loop was then loosely secured to excoriated area with 2-O nylon (stay suture) which was tied subcutaneously in all groups. Four puncture wounds were made with a 20-gauge hypodermic needle in the bowel that was apposed to the excoriated peritoneal musculature which allowed leakage of intestinal contents and contamination. On Day 7 postsurgery, the animals were anesthetized and the stay suture was removed. On Day 14, all animals were sacrificed and adhesions were graded. The incidence of significant adhesions was 28% for the barrier group versus 90% for control animals (P < 0.05). The results of this study indicate that the polypentapeptide of elastin sheet is an effective physical barrier in this surgically induced contaminated wound model.

Awake porcine model of intraperitoneal sepsis and altered oxygen utilization.

We have characterized an awake swine model of septic shock. Hemodynamic, serum chemistry, and oxygen metabolism parameters were compared between eight septic and five sham animals. Eight male Yucatan miniature swine, weighing 20-28 kg, were anesthetized and catheters were placed in the pulmonary artery, external jugular, and the carotid artery. On day 2, 1.1-4.0 x 10(10) cfu Escherichia coli/kg were administered via an intraperitoneal catheter. Hemodynamic parameters were monitored hourly for 6 hours in awake animals. The animals were then placed back into the animal holding facility for clinical observation until the 24 hour post infusion measurements were taken. Septic animals were initially hypodynamic, with a decrease in cardiac index (CI) from a baseline value of 152.8 +/- 24.8 to 87.9 +/- 17.8 ml/kg/min (P less than .05) and an increased systemic vascular resistance index (SVRI) from a control value of 48.1 +/- 9.5 to 65.0 +/- 16.7 dynes*sec*cm-5/kg. At 24 hours post infusion, the animals were hyperdynamic with the CI increased to 211.0 +/- 27.2 ml/kg/min (P less than .05) and a decreased SVRI to 30.64 +/- 3.9 dynes*sec*cm-5/kg (P less than .05). Oxygen utilization (VO2) increased during sepsis from 6.6 +/- 0.8 to 8.1 +/- 0.8 ml/kg/min at 6 hours (P less than .05) and remained elevated at 24 hours at 7.7 +/- 0.4 (P less than .05). Increased oxygen consumption was attained with an increase in oxygen extraction (O2 ext) from 0.34 +/- 0.03 to 0.56 +/- 0.07 (P less than .05) during the first 6 hours of sepsis. At 24 hours, increased oxygen utilization was maintained by high oxygen delivery state. Significant alterations in serum chemistries in conjunction with post mortem evidence of multiple organ system failure were observed. Mortality on or before 4 days post infusion was 50% and positive blood cultures were obtained in 38% of the animals studied. This awake swine model serves as an excellent model to study metabolic pathophysiology and the treatment of septic shock.

Acute sarcocystosis-like disease in a dog.

Two of 8 littermate Rottweiler dogs developed persistent diarrhea at 6.5 weeks of age. Dog 1 was euthanatized at 14 weeks of age and had hepatitis characterized by necrosis and mixed leukocyte infiltrations in association with a previously unrecognized Sarcocystis-like protozoon. The organism was free in the hepatocyte cytoplasm without a parasitophorous vacuole, had divided by schizogony, and stained with anti-Sarcocystis serum, but did not stain with anti-Toxoplasma gondii or anti-Neospora caninum serum in an immunohistochemical test. Dog 2 was euthanatized at 10 weeks of age. This dog had large necrotic, hemorrhagic mesenteric lymph nodes. Numerous T gondii tachyzoites were observed in association with these lesions. The organism divided by endodyogeny and stained specifically with anti-T gondii serum.