The aim of this study was to compare treatment with cultured bone marrow stromal cells (cBMSCs), bone marrow Mononucleated Cells (BMMNCs), and placebo to repair collagenase-induced tendinitis in horses. In six adult Standardbred horses, 4000 IU of collagenase were injected in the superficial digital flexor tendon (SDFT). Three weeks after collagenase treatment, an average of either5.5×106cBMSCs or1.2×108BMMNCs, fibrin glue, and saline solution was injected intralesionally in random order. In cBMSC- and BMMNCS-treated tendons, a high expression of cartilage oligomeric matrix protein (COMP) and type I collagen, but low levels of type III collagen were revealed by immunohistochemistry, with a normal longitudinally oriented fiber pattern. Placebo-treated tendons expressed very low quantities of COMP and type I collagen but large numbers of randomly oriented type III collagen fibers. Both cBMSC and BMMNCS grafts resulted in a qualitatively similar heling improvement of tendon extracellular matrix, in terms of the type I/III collagen ratio, fiber orientation, and COMP expression.

Objective—To compare the effect of 2 concentrations of oxygen in inspired gas (fraction of inspired oxygen [FIO₂] 1.0 or 0.4) on pulmonary aeration and gas exchange in dogs during inhalation anesthesia. Animals—20 healthy dogs. Procedures—Following administration of acepromazine and morphine, anesthesia was induced in each dog with thiopental and maintained with isoflurane in 100% oxygen (100% group; n = 10) or a mixture of 40% oxygen and air (40% group; 10). Dogs were placed in dorsal recumbency and were mechanically ventilated. After surgery, spiral computed tomography (CT) of the thorax was performed and PaO₂, PaCO₂, and the alveolar-arterial oxygen tension difference (P_[A–a]O₂) were assessed. The lung CT images were analyzed, and the extent of hyperinflated (−1,000 to −901 Hounsfield units [HUs]), normally aerated (−900 to −501 HUs), poorly aerated (−500 to −101 HUs), or nonaerated (−100 to +100 HUs) areas was determined. Results—Compared with the 100% oxygen group, the normally aerated lung area was significantly greater and the poorly aerated and nonaerated areas were significantly smaller in the 40% oxygen group. The time to CT (duration of surgery) was similar in both groups. Although PaCO₂ was similar in both groups, PaO₂ and P_(A–a)O₂ were significantly higher in the 100% oxygen group. In both groups, pulmonary atelectasis developed preferentially in caudal lung fields. Conclusion and Clinical Relevance—In isoflurane-anesthetized dogs, mechanical ventilation with 40% oxygen appeared to maintain significantly better lung aeration and gas exchange than ventilation with 100% oxygen.

In this study we evaluated the performance of Skelite, a resorbable bioceramic based on silicon stabilized tricalcium phosphate (Si-TCP), in promoting the repair of a large-sized, experimentally induced defect in a weight-bearing long bone sheep model. Eighteen 2-year-old ewes were used in this study. Animals were sacrificed at 3, 6, and 12 months. One animal entered a very prolonged followup and was sacrificed 2 years after surgery. Bone formation and scaffold resorption were evaluated by sequential x-ray studies, CT scans, histology, immunohistology, microradiography, and quantitative analysis of x-ray studies (optical density) and microradiographs (percentage of bone and scaffold area). Our data show an excellent implant integration and significant bone regeneration within the bone substitute over the course of the experiment. Progressive osteoclastic resorption of the biomaterial was also evident. At 1 year from surgery, the remaining scaffold was approximately 10–20% of the scaffold initially implanted, while after 2 years it was essentially completely resorbed. At the end of the observation period, the segmental defect was filled with newly formed, highly mineralized, lamellar bone.

Rationale: The open lung strategy aims at reopening (recruitment) of nonaerated lung areas in patients with acute respiratory distress syndrome, avoiding tidal alveolar hyperinflation in the limited area of normally aerated tissue (baby lung). Objectives: We tested the hypothesis that recruited lung areas do not resume elastic properties of adjacent baby lung. Methods: Twenty-five anesthetized, mechanically ventilated pigs were studied. Four lung-healthy pigs served as controls and the remaining 21 were divided into three groups (n = 7 each) in which lung injury was produced by surfactant lavage, lipopolysaccharide infusion, or hydrochloride inhalation. Computed tomography scans, respiratory mechanics, and gas exchange parameters were recorded under three conditions: at baseline, during lung recruitment maneuver, and at end-expiration and end-inspiration when ventilating after an open lung protocol. Measurements and Main Results: During recruitment maneuver and open lung protocol, the gas volume entering the insufficiently aerated compartment was 96% (75–117%) and 48% (41–63%) (median [interquartile range]) of the functional residual capacity measured before and at zero end-expiratory pressure, respectively. Nonetheless, the volume of hyperinflated lung increased during both recruitment maneuver (by 1–28% of total lung volume; P < 0.01) and open lung protocol ventilation at end-inspiration (by 1–15% of total lung volume; P < 0.01). Regional elastance of recruited lung tissue was consistently higher than that of the baby lung regardless of the ARDS model (P < 0.01). Conclusions: Alveolar recruitment is not protective against hyperinflation of the baby lung because lung parenchyma is inhomogeneous during ventilation with the open lung strategy.