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Biomedical subjects

O Lima

Publications and source records attributed to O Lima.

12 recordsLinked to original sources
PubMed2004

Plasma cell cheilitis.

Plasma cell cheilitis is a rare inflammatory disorder of the lip with a characteristic band-like infiltrate of plasma cells in the upper dermis. Differential diagnosis should consider allergic/irritant contact cheilitis, candidiasis, syphilis, Queyrat's erythroplasia, granulomatous cheilitis, plasmoacanthoma, plasmacytoma, squamous cell carcinoma and exfoliative or factitious cheilitis. We observed plasma cell cheilitis in a 60-year-old Caucasian female who had a partial response to topical steroids and oral griseofulvin.

Antifungal Agents↗
PubMed1996

Purification, in vitro reassembly, and preliminary sequence analysis of epiplasmins, the major constituent of the membrane skeleton of Paramecium.

The epiplasmic layer, a continuous rigid granulo-fibrillar sheet directly subtending the surface membranes of Paramecium, is one of the outermost of the various cytoskeletal networks that compose it cortex. We have previously shown that the epiplasm consists of a set of 30 to 50 protein bands on SDS-PAGE in the range 50 to 33 kDa, the epiplasmins. We report a purification procedure for the set of epiplasmic proteins, a description of their physicochemical and reassembly properties, and a preliminary characterization of their sequence. The conditions for solubilization of the epiplasm and for in vitro reassembly of its purified constituents ar described. Reassembly of the entire set of proteins and of some (but not all) subsets are shown to yield filamentous aggregates. Microsequences of two purified bands of epiplasmins reveal a striking amino acid sequence consisting of heptad repeats of only three main amino acids, P, V, and Q. These repeats were confirmed by DNA sequencing of polymerase chain reaction products. The motif is QPVQ-h, in which h is a hydrophobic residue. This may constitute the core of the epiplasmin sequence and, in view of the tendency of such a sequence to form a coiled-coil, may account for the remarkable self-aggregation properties of epiplasmins.

Amino Acid Sequence↗
PubMed1993

Lung preservation with low-potassium dextran flush in a primate bilateral transplant model.

We used a bilateral lung transplant model to confirm, in primates, the results of lung preservation studies previously obtained in a canine single-lung transplant model. The donor lungs were flushed with low-potassium dextran solution and maintained semiinflated with 100% oxygen at 10 degrees C for a planned ischemic time of 12 hours for the lung implanted first. Of eight experiments performed, results in the 6 operative survivors form the basis of this report. After bilateral lung transplantation, animals were maintained on a ventilator for 6 hours; arterial oxygen tension, pulmonary artery pressure, and pulmonary vascular resistance were determined in the recipients at 2, 4, and 6 hours after transplantation and compared with donor values, which served as controls. Arterial oxygen tension in the recipients did not differ from the controls (p = not significant), whereas the pulmonary artery pressure and pulmonary vascular resistance showed significant elevation (p < 0.05 versus control values). After the 6 hours of assessment, the animals were extubated and 3 survived for 48 to 72 hours with a mean arterial oxygen tension of 69 mm Hg on room air. These results demonstrate excellent lung function after a minimum of 12 hours of preservation in a primate model in which the animal is totally dependent on the function of transplanted lung tissue, and confirm the potential for prolonged clinical lung preservation.

Animals↗
PubMed1993

Evaluation of lung metabolism during successful twenty-four-hour canine lung preservation.

We used a canine left lung allotransplantation model to evaluate 24-hour lung preservation with two different electrolyte solutions, low-potassium dextran and low-potassium dextran with 1% glucose. To investigate changes in the energy status during preservation, we analyzed the lungs for adenosine triphosphate, phosphocreatine, and several metabolites of the glycolysis pathway and the citric acid cycle: glucose, glucose-6-phosphate, lactate, citrate, and malate. We also devised and evaluated a pulmonary cooling jacket to prevent rewarming of the lung during implantation. The lungs were divided into four groups. Groups I (n = 10) and II (n = 6) were flushed with low-potassium dextran and groups III (n = 6) and IV (n = 6) were flushed with low-potassium dextran solution with 1% glucose. The cooling jacket was used for groups II and IV only. After 24-hour preservation at 10 degrees C, the left lungs were implanted into the recipient animals. Function of the transplanted left lung was assessed during temporary (10 minutes) occlusion of the contralateral pulmonary artery while both lungs were ventilated with 100% oxygen. This assessment was performed at 1 hour and at 3, 8, and 22 days after transplantation. Immediately after transplantation the arterial oxygen tension was 279 +/- 70 mm Hg in group I, 376 +/- 56 mm Hg in group II, 523 +/- 41 mm Hg in group III, and 518 +/- 50 mm Hg in group IV. The arterial oxygen tension in groups III and IV were significantly greater than in group I (p < 0.05). Of the lungs preserved with low-potassium dextran solution with 1% glucose solution, 11 of 12 (92%) showed excellent lung function (arterial oxygen tension > 300 mm Hg) at 3 days; only 10 of 16 lungs preserved with low-potassium dextran achieved this level of function. Glucose, glucose-6-phosphate, lactate, citrate and malate levels decreased significantly during 24-hour preservation with low-potassium dextran solution; they were stable with low-potassium dextran solution with 1% glucose. Adenosine triphosphate and phosphocreatine were stable for 24 hours with both low-potassium dextran and low-potassium dextran solution with 1% glucose. The cooling jacket provided uniform cooling of the lung parenchyma during implantation, and significant increase in temperature was observed in its absence, with topical cooling by cold saline solution.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗
PubMed1992

In a canine model, lung preservation at 10 degrees C is superior to that at 4 degrees C. A comparison of two preservation temperatures on lung function and on adenosine triphosphate level measured by phosphorus 31-nuclear magnetic resonance.

Techniques for organ preservation generally use hypothermia to retard metabolic requirements. However, excessive hypothermia may also produce injury. Using a canine left lung allotransplantation procedure, we compared two preservation temperatures (4 degrees and 10 degrees C) in terms of subsequent lung function measured by temporary occlusion of the right pulmonary artery after implantation of the preserved left donor lung. The lungs were flushed with low-potassium dextran electrolyte solution, inflated with 100% oxygen, and preserved for 18 hours. To investigate possible changes of energy stores at different temperatures, we performed phosphorus 31-nuclear magnetic resonance analyses of lung samples. Sequential determinations of adenosine triphosphate levels in lung tissue preserved at 4 degrees, 10 degrees, and 22 degrees C were studied. After transplantation, lungs preserved at 10 degrees C (n = 6) provided significantly better arterial oxygen tension than those preserved at 4 degrees C (n = 6), 451 +/- 46 mm Hg versus 243 +/- 86 mm Hg (p less than 0.05), and lower pulmonary vascular resistance, 581 +/- 68 dynes.sec.cm-5 versus 1006 +/- 157 dynes.sec.cm-5 (p less than 0.05). Adenosine triphosphate levels at 4 degrees and 10 degrees C were stable and did not differ from each other at the end of the 18-hour preservation period: 0.86 +/- 0.04 mumol/gm wet weight for control versus 0.86 +/- 0.07 mumol/gm wet weight for 4 degrees C and 0.93 +/- 0.06 mumol/gm wet weight for 10 degrees C after 18 hours of preservation. Preservation at 22 degrees C caused a 28% depression of adenosine triphosphate after 18 hours of preservation. These results lead us to conclude the following: (1) Optimal temperature for lung preservation is in the vicinity of 10 degrees C, and (2) lung dysfunction caused by excessive hypothermia is not due to a failure to maintain adenosine triphosphate levels. We suspect that adenosine triphosphate is generated by oxidative phosphorylation during lung preservation.

Adenosine Triphosphate↗
PubMed1983

Improved bronchial healing in canine left lung reimplantation using omental pedicle wrap.

Bronchial complications are a major problem following lung transplantation. Ischemia of the donor bronchus is an important underlying cause of these complications. We have previously demonstrated the ability of an omental pedicle flap to revascularize the donor bronchus as early as 4 days following canine left lung reimplantation. In the present study, omental pedicle wraps markedly improved the healing of the bronchial anastomoses 23 days following canine left lung reimplantation. In dogs in which omentum was used (n = 6), the bronchial mucosal appearance was more normal and the degree of bronchostenosis was significantly less when compared with dogs without omental flaps (n = 10). These experiments suggest that the use of omental pedicle flaps may significantly reduce bronchial complications following lung transplantation.

Animals↗
PubMed1983

A comparison between cyclosporin A and methylprednisolone plus azathioprine on bronchial healing following canine lung autotransplantation.

The effects of two low-dose immunosuppressive therapies upon the healing of the bronchial anastomosis and skin wounds following lung autotransplantation were evaluated. Autotransplantation was performed in three groups of dogs: Group 1 (nine dogs) received no immunosuppression, Group 2 (seven dogs) received postoperative immunosuppression with methylprednisolone (2 mg/kg) and azathioprine (1.5 mg/kg), and Group 3 (four dogs) received postoperative immunosuppression with cyclosporin A (20 mg/kg/day). Skin incisions 7 cm in length were made in the dorsal region of each dog. Dogs were put to death 23 days postoperatively, and the breaking strength of the bronchial anastomoses and skin wounds was evaluated with the Instron Universal Testing Machine, with a cross-head speed of 0.5 cm/min. Bronchial breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Skin breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Scanning electron microscopic (SEM) studies of both skin and bronchial wounds showed normal formation of collagen bundles in Groups 1 and 3 but a disorganized pattern in Group 2. Our results suggest that low-dose immunosuppression with methylprednisolone and azathioprine significantly affects wound healing and breaking strength of both bronchial anastomoses and healed skin incisions following canine lung autotransplantation. Immunosuppression with cyclosporin A had no adverse effect on either bronchial or skin healing.

Animals↗
PubMed1982

Successful revascularization of totally ischemic bronchial autografts with omental pedicle flaps in dogs.

In 10 dogs, the left lung was removed and a closed stump of bronchus, comprising the distal main and lobar bronchi, was reanastomosed to the main bronchus. This totally ischemic cul-de-sac of bronchus was wrapped by an omental flap in five of the 10 dogs. All dogs without an omental wrap died of graft necrosis within 5 days. Injection studies into the bronchial arteries failed to demonstrate any revascularization of the bronchial grafts. In contrast, those dogs with omental wraps, when put to death at 23 days, displayed healthy viable bronchial grafts with full revascularization from the omental vessels. In another three dogs the revascularization via the omentum was demonstrated as early as 4 days and well established at 8 days. The ability of the omentum to rapidly revascularize the bronchus may be of value in potentially ischemic bronchial anastomoses such as in lung transplantation.

Animals↗
PubMed1981

Effects of methylprednisolone and azathioprine on bronchial healing following lung autotransplantation.

The effect of low-dose immunosuppressive therapy upon the healing of the bronchial anastomosis and skin wound following lung autotransplantation was evaluated. Autotransplantation was performed in two groups of dogs: Group 1 (15 dogs) received no immunosuppression and Group 2 (13 dogs) received postoperative immunosuppression with methylprednisolone (2 mg/kg) and azathioprine (1.5 mg/kg). Two to four skin incisions 7 cm in length were made in the dorsal region of each dog. Dogs were put to death at 4, 9, 16, and 23 days postoperatively and the bronchial anastomoses and skin wounds were evaluated by breaking strength measurements. Bronchus and skin breaking strength increased with time in both groups. Bronchus breaking strength was similar in the two groups at day 4 and day 9. However, by day 23 bronchus breaking strength was significantly higher in Group 1 (p less than 0.001). Skin breaking strength was significantly higher in Group 1 on days 9 and 16 (p less than 0.005) and on day 23 (p less than 0.001). Our results suggest that low-dose methylprednisolone and azathioprine significantly affect the breaking strength of both bronchial anastomoses and healing skin incisions following canine lung autotransplantation.

Animals↗