A Novel Porcine Model of Ischemia-Reperfusion Injury After Cross-Clamping the Thoracic Aorta Revealed Substantial Cardiopulmonary, Thromboinflammatory and Biochemical Changes Without Effect of C1-Inhibitor Treatment.

Ischemic injury worsens upon return of blood and innate immunity including the complement system play a central role in ischemia-reperfusion injury (IRI) as in thoracic aortic surgery. Complement component1 inhibitor (C1-INH) has been shown to reduce IRI and is a broad-acting plasma cascade inhibitor. We established a new porcine model of IRI by cross-clamping the thoracic aorta and evaluated the global changes occurring in organ function, systemic inflammatory response and organ damage with or without treatment with C1-INH-concentrate. Twenty-four piglets (8.8-11.1 kg) underwent 45 minutes clamping of the thoracic aorta at the Th8 level. Upfront 12 piglets received human saline and 12 received C1-INH (250 IU/kg) intravenously. Three sham animals received thoracic opening without clamping. Reperfusion lasted 5 hours. We studied ten cardiorespiratory markers, three hematologic markers, eleven inflammatory markers, and twelve organ damage markers over the whole experimental period. Postmortem tissue homogenates from seven organs were examined for inflammatory markers and analysed by two-way repeated-measures ANOVA, area under the curve or unpaired t-tests. By excluding sham and combining treated and untreated animals, the markers reflected a uniform, broad and severe organ dysfunction. The mean and range fold change from before cross-clamp onset to maximum change for the different groups of markers were: cardiorespiratory 1.4 (0.2-3.7), hematologic 1.9 (1.2-2.7), plasma inflammatory 19.5 (1.4-176) and plasma organ damage 2.9 (1.1-8.6). Treatment with C1-INH had only a marginal effect on the IRI-induced changes, reaching statistical significance only for the plasma complement activation product TCC (p=0.0083) and IL-4 (p=0.022) and INF-α (p=0.016) in the colon tissue. In conclusion, the present novel model of porcine global IRI is forceful with regards to central markers and could generally be applicable for pathophysiological studies. C1-INH treatment had no significant effect, but the model allows for future testing of other drugs attenuating IRI globally.

Plantar puncture wounds in children: analysis of 80 hospitalized patients and late sequelae.

BACKGROUND: Puncture wounds in the feet of children present a clinical dilemma. OBJECTIVES: To evaluate our approach, we reviewed the charts and all available images of 80 children admitted to our institution because of plantar punctures from 1988 to 1999. METHODS: The charts of 80 children were reviewed retrospectively. RESULTS: Three groups of patients were found: 59 with superficial cellulitis, 11 with retained foreign bodies, and 10 with osteoinyelitis and/or septic arthritis. There was a significant presentation delay in patients from the second and third groups. Most common organisms were Staphylococcus aureus or Group A Streptococcus. Of the 80 children, 34 were treated surgically and 46 were treated with antibiotic therapy alone. All patients with osteomyelitis and septic arthritis were re-examined; at follow-up, all but one were asymptomatic apart from residual radiologic sequelae in four. CONCLUSIONS: Patients with an established infection 24-36 hours after a plantar puncture should be admitted to hospital for parenteral antibiotic therapy. Delayed presentation is a significant marker for deep-seated infection. Further infection or relapse after initial improvement suggests the presence of osteomyelitis or a retained foreign body. A bone scan is advisable in all patients with suspected osteomyelitis: a positive bone scan necessitates aggressive early debridement combined with appropriate antibiotics; while negative bone scan, X-ray and exploration suggest that the infection is due to a foreign body, which can be detected by computed tomography.

The effects of enoxaparin on the reparative processes in experimental osteonecrosis of the femoral head of the rat.

The blood supply of one femoral head of 6-month-old rats was severed by incising the periosteum of the neck and cutting the ligamentum teres. The rats were killed on the 30th postoperative day and the femoral bones were obtained for semiquantification of the reparative processes in the necrotic heads. Fourteen rats were treated with enoxaparin and 14 untreated animals served as controls. Statistically, the amounts of necrotic bone in the epiphysis were less, the extent of remodeling of the femoral heads was milder, and the articular cartilage degeneration was slighter in the enoxaparin-treated than untreated rats. There was no significant difference in the quantities of newly formed bone in femoral heads of treated and untreated rats. These findings are in agreement with the known effects of unfractionated and low-molecular-weight heparins which enhance osteoclastic bone resorption and angiogenesis and decrease osteoblastic bone formation. The former activities, operative in minimizing the structural distortion of the femoral head, oppose the crucial event in the pathogenesis of post-osteonecrotic osteoarthritis.