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Biomedical subjects

R Olmos

Publications and source records attributed to R Olmos.

8 recordsLinked to original sources
PubMed1992

Pulmonary perfusion during lung transplant rejection and experimental pneumonia.

Six left lung allotransplants were performed in healthy mongrel dogs. Immunosuppression was established with cyclosporine (15 mg/kg/day p.o.) from the day of transplantation for 30 days. Another group of animals (n = 3) was used to produce acute experimental pneumonia by instilling 4-6 ml of a 10(8) CFU suspension of Pseudomonas aeruginosa into the right lower lobe. Dynamic perfusory lung scintigraphy (DPLS) was performed before transplant/pneumonia (control), during acute rejection/pneumonia as detected radiologically, and after treatment with methylprednisolone (1 g/day for 3 days i.v.) (transplant group) or antibiotics (pneumonia group). Seroalbumin macroaggregates (5-8 McI) marked with 99-mTc were injected into the cephalic vein and the percentage of perfusion to each lung was determined. Eight acute rejection episodes were detected. DPLS showed similar perfusion to each lung, whereas during acute rejection perfusion was significantly reduced by almost 30%. Perfusion was reestablished to control levels after treatment with methylprednisolone. Reduction in perfusion correlated with radiological rejection grading. No reduction in left lung perfusion was detected in pneumonia animals. In conclusion, acute rejection reduces perfusion to the transplanted lung as measured by DPLS. Treatment restores normal perfusion.

Animals↗
PubMedDate not supplied

Inflammatory cells and ferruginous bodies in bronchoalveolar lavage in urban dogs.

OBJECTIVE: To investigate whether high levels of atmospheric pollution modify the inflammatory cell count of the canine lung and to detect the presence of ferruginous bodies (FB) in the respiratory system. STUDY DESIGN: Bronchoalveolar lavage (BAL) was performed on dogs from four different areas of Mexico City and a rural area. With the BAL fluid recovered, total and differential cell counts were made, and ferruginous bodies were isolated by sodium hypochlorite digestion. They were counted by light microscopy and evaluated as a marker of exposure to particulate pollutants. RESULTS: There was no significant difference in the total cell count or in the macrophage number between the five groups. The neutrophil count was statistically higher in dogs from the southwest area as compared to the northeast and rural areas (P < .05). The lymphocyte count was significantly greater in the southwest, also. The northeast part of the city showed the highest number of FB in BAL fluids. CONCLUSION: The most polluted areas, in terms of particulate matter, were the northeast and the northwest; those are the locations of heavy industry. In contrast, in the southwest, where more inflammation was seen, the highest levels of ozone were registered during the year.

Animals↗
PubMedDate not supplied

Pulmonary arterial contribution to airway blood flow after lung transplantation in dogs.

Despite the improved success of lung transplantation, ischemia of the donor bronchus continues to be the most important factor influencing airway healing. Recent studies have shown that at the level of the mainstem bronchi the pulmonary contribution to the airway blood flow may be equivalent to or greater than the systemic contribution and could therefore assist early healing of the newly anastomosed bronchus and, in addition, might facilitate the improved healing associated with omentopexy. The aim of this study was to measure the pulmonary contribution to airway blood flow in dogs after allotransplantation of the left lung and to determine whether omentopexy might improve the healing process. Using the radioactive microsphere technique, we measured the pulmonary contribution to airway blood flow in 25 dogs 1 week after allotransplantation of the left lung. Half the dogs had an omental wrap around the anastomotic site. Results showed that pulmonary blood flow increased progressively from lower trachea to distal mainstem bronchus and supplied the left mainstem bronchus above as well as below the anastomotic site. Omentopexy did not increase flow or enhance healing.

Animals↗
PubMedDate not supplied

Thoracoabdominal wall repair with glutaraldehyde-preserved bovine pericardium.

Glutaraldehyde-preserved bovine pericardium (GPBP) is evaluated as a bioprosthesis for the reconstruction of surgical defects in the thoracoabdominal wall. The mechanical properties of bovine pericardium preserved at different concentrations of glutaraldehyde were studied. Samples preserved in 0.5% glutaraldehyde showed a significantly higher tensile strength (11.7 +/- 0.8 N/mm2) than samples preserved in 2.5, 5, or 10% (similar to pericardium preserved in normal saline). The percentage of elongation was significantly lower than samples preserved in 1, 2.5, and 5% glutaraldehyde. GPBP at 0.5% was used to repair experimentally induced defects of the abdominal wall (n = 9), chest wall (n = 6), diaphragm (n = 6), and sternum (n = 7). All animals presented adequate tolerance to the material used and no case of infection or rejection of the material was seen in any of the animals. Finally, 0.5% GPBP was used clinically in a series of 40 patients: postincisional abdominal hernia (n = 30), inguinal hernia (n = 8), diaphragmatic hernia (n = 1), and congenital pelvic defect with prolapse of abdominal organs (n = 1). Surgical use showed that GPBP was a very manageable material and long-term results were good in 37 patients with a mean follow up of 18 months (range 5-35 months). Six patients presented seroma formation (all abdominal hernia patients), three of which eventually developed infection and had the GPBP patch removed at 3, 5, and 7 months postoperatively. The rest of the patients presented good scar formation with adequate resistance at the area of implantation. GPBP is a biological material with sufficient resistance to be used surgically in the repair of thoracoabdominal defects. Ideal concentration of glutaraldehyde to be used in the preparation-preservation of the material is 0.5% since higher concentration negatively affect its tensile rupture strength and elongation.

Abdominal Muscles↗
PubMedDate not supplied

[Repair of thoracoabdominal wall defects in dogs using a bovine pericardium bioprosthesis].

OBJECTIVES: To evaluate the in-vitro resistance of a pericardial tissue bioprothesis as well as its use for the reconstruction of surgical defects in the thoracoabdominal wall. MATERIALS AND METHODS: The prosthesis were preserved for 15 days in different concentrations of glutaraldehyde (0.5% to 10%). Normal saline and Hanks solution were used as controls. Tensile strength and percent elongation were measured using an Instrom 1011 automatic equipment; polypropilene (Marlex) and polyester (Mersilene) mesh samples were included. Also, the 0.5% glutaraldehyde-preserved pericardium was used to repair defects experimentally produced in the abdominal wall (n = 12), chest wall (n = 6), diaphragm (n = 6), and sternum (n = 7) of mongrel dogs. RESULTS: The samples preserved in 0.5% glutaraldehyde showed a significantly higher tensile strength (11.7 N/mm2, SEM = 0.8) than samples preserved in other concentrations as well as in the mesh samples. Percent elongation in 0.5% glutaraldehyde was 56% (SEM = 5.8) which was similar to the meshes' elongation but significantly lower than that seen for the 1%, 2.5% and 5% glutaraldehyde-preserved samples. The dogs showed good tolerance to the 0.5% preparation and the histopathology showed formation of a fibroblast layer with collagen deposits and development of scar tissue. There was no case of infection or rejection in the animals, and all the microbiological cultures of the preparations were negative. CONCLUSION: Pericardial bioprothesis is a resistant material which can be used surgically in the repair of thoracoabdominal defects.

Abdominal Muscles↗