Subconjunctival use of allogeneic mesenchymal stem cells to treat chronic superficial keratitis in German shepherd dogs: Pilot study.

Background: Chronic superficial keratitis (CSK) is an ocular condition in dogs characterized by corneal opacification leading to visual function impairment. Control of this chronic condition requires the use of topical immunomodulators or corticosteroids daily. Regenerative medicine has shown promising results in several fields of medicine. Aim: The aim of this study was to evaluate the clinical effect of allogeneic mesenchymal stem cells (MSCs) of adipose tissue applied via subconjunctival in dogs with CSK. Methods: A series of cases of eight dogs diagnosed with CSK were divided into two groups, four dogs each; the conventional treatment group received prednisolone 1% as topical eye drops and the experimental group (EG) received allogeneic MSCs transplantation. The dogs had not previously been treated for CSK. Systemic and ophthalmologic examinations were performed to exclude other abnormalities. An administered amount of MSC (1 × 106 cells each time) was injected via subconjunctival in the peri-limbal region at 0 and 30 days. The animals were followed for 110 days for clinical evaluation, and, at the same time, the images of the corneal abnormalities were obtained and analyzed in the ImageJ software. The statistical analysis was performed in the GrandPrism 7.0 software. Results: Initial and final images revealed that areas with neovascularization, inflammatory infiltrate, and opacity regressed in most eyes in both groups (7/8 eyes in each group) at the end of the 110 days, p = 0.0391 and p = 0.0078 respectively, but this response was minor in the EG comparing to conventional group (CG) (p = 0.026). No local or systemic side effects were observed. Conclusions: Despite the small melioration, MSCs treatment suggests clinical improvement in patients with CSK after 110 days without any local or systemic side effects. However, the improvement achieved was significantly less than the observed within CG. Further studies still are needed to evaluate the use and benefits of stem cells as an adjunct treatment for CSK.

Effects of oxygen in lungs of rats.

PURPOSE: To analyze microscopically the effects of different concentrations of oxygen in the lungs of rats. METHODS: There were 20 rats distributed in three experimental groups (concentration of oxygen to 40%, 70% and 100%) and a control group. The animals were exposed to the oxygen in a chamber of acrylic during three days and after exposition, the animals were submitted to median thoracotomia to remove the lungs. The lung tissue of all of the animals was analyzed as regards presence of acute and chronic inflammation, capillary congestion, alveolar walls thick, interstitial and alveolar edema, alveolar hemorrhage, denudation capillary and alveolar endothelium areas and atelectasis. RESULTS: The analysis histopathologic revealed significant statistics difference for acute and chronic inflammation, capillary congestion, alveolar walls thick, interstitial and alveolar edema, alveolar hemorrhage, denudation capillary and alveolar epithelium areas. CONCLUSIONS: Exposition to the oxygen during 72 hours in the concentration of 40% does not produce significant histopathologic alterations in the lung tissue; in the concentration of 70%, can promotes the alveolar walls thick and capillary congestion and in the concentration of 100% can cause death and originate diffuse pulmonary lesion.

Effects of oxygen in lungs of rats

PURPOSE: To analyze microscopically the effects of different concentrations of oxygen in the lungs of rats. METHODS: There were 20 rats distributed in three experimental groups (concentration of oxygen to 40%, 70% and 100%) and a control group. The animals were exposed to the oxygen in a chamber of acrylic during three days and after exposition, the animals were submitted to median thoracotomia to remove the lungs. The lung tissue of all of the animals was analyzed as regards presence of acute and chronic inflammation, capillary congestion, alveolar walls thick, interstitial and alveolar edema, alveolar hemorrhage, denudation capillary and alveolar endothelium areas and atelectasis. RESULTS: The analysis histopathologic revealed significant statistics difference for acute and chronic inflammation, capillary congestion, alveolar walls thick, interstitial and alveolar edema, alveolar hemorrhage, denudation capillary and alveolar epithelium areas. CONCLUSIONS: Exposition to the oxygen during 72 hours in the concentration of 40% does not produce significant histopathologic alterations in the lung tissue; in the concentration of 70%, can promotes the alveolar walls thick and capillary congestion and in the concentration of 100% can cause death and originate diffuse pulmonary lesion. .