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F S Vargas

Publications and source records attributed to F S Vargas.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Low concentration silver nitrate pleurodesis in rabbits: optimal concentration for rapid and complete sclerosing effect.

Pleurodesis is a useful therapeutic tool when local treatment of a recurrent malignant pleural effusion or pneumothorax is needed. We have previously demonstrated that the intrapleural injection of 0.5% silver nitrate (SN) produces a significant pleurodesis, while 0.25% SN has no sclerosing effect in a rabbit model. The objective of this study was to determine the minimum concentration of SN needed to induce pleurodesis in our experimental model. One hundred twenty male New Zealand white rabbits received 0.3, 0.4, or 0.5% SN (40 animals per group) in a total volume of 2 mL instilled intrapleurally. These animals were sacrificed 3, 7, 14 or 28 days after the intrapleural injection (n = 10 animals per group), and the pleural spaces were then assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. By 28 days, all concentrations of SN had produced a pleurodesis. There was evidence of a gross pleurodesis 7 days post-injection in animals that received 0.5% SN (score of 2.8 +/- 0.2 on a scale of 0-4). After 14 days, significant pleural adhesions were evident in the groups that received 0.4 or 0.5% SN. We conclude that SN concentrations as low as 0.3% can effectively produce a pleurodesis within 28 days of intrapleural injection. However, the precocious pleurodesis development observed 7 days after the intrapleural injection of 0.5% SN suggests that this concentration may be optimal when a fast result is necessary.

Animals↗
PubMedDate not supplied

Effectiveness of silver nitrate compared to talc slurry as pleural sclerosing agent in rabbits. Influence of concomitant intrapleural lidocaine.

UNLABELLED: The ideal agent for producing pleurodesis has not been identified. Talc, the most commonly used, poses several problems. Another possibility is silver nitrate, which was widely used in the past. PURPOSE: To determine the influence of the intrapleural instillation of lidocaine in producing a pleurodesis with silver nitrate, to define the effect of lidocaine in the maturation of the collagen fibers, and to confirm that the pleurodesis after silver nitrate is stronger than after talc. METHODS: We studied three groups of 8 rabbits. Two groups received 0.5% silver nitrate; in one we had previously injected 0.5 ml of 2% lidocaine. The third group received 400 mg/kg talc (2 ml). The animals were sacrificed 28 days after the injection, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of inflammation and fibrosis. The total amount of pleural collagen and the distribution of thick and thin collagen fibers were quantified. Collagen was identified using picrosirius red stain. RESULTS: In the two groups that received silver nitrate (without lidocaine: 3.5 + 03 and with lidocaine: 3.2 + 0.3), the macroscopic pleurodesis (scale 0 - 4) was significantly (p = 0.001) better than that resulting from talc (1.6 + 0.2). The mean degree of pleural fibrosis induced by silver nitrate (3.5 + 0.2) was significantly (p = 0.004) higher than that induced by talc (1.9 + 0.1). The previous instillation of lidocaine resulted in a tendency for decreased amounts of fibrosis (3.1 + 0.4). The mean amount (10(3)mm2) of pleural collagen was significantly (p = 0.009) greater in the rabbits that received silver nitrate (116.9 + 22.7) than in those that received talc (10.7 + 3.4). The injection of lidocaine slightly reduced the collagen (80.1 + 30.3). The distribution of collagen fibers did not differ among the groups. CONCLUSION: This rabbit model clearly confirms that intrapleural silver nitrate is more effective than talc for producing pleurodesis. The previous intrapleural instillation of lidocaine results in a decreasing trend in the amount of collagen, but does not change the effectiveness of the pleural fusion or modify the process of collagen maturation.

Anesthetics, Local↗
PubMedDate not supplied

[Value of lamellar body quantification in leukocytes in amiodarone toxicity].

Amiodarone is an amphiphilic drug that penetrates easily through the plasmatic membrane and can induce the production of lysosome lamellar bodies in virtually all cells of the organism, independently of toxic effects. This study determines the value of searching for lamellar bodies in peripheric leucocytes as a method of prevention of pulmonary toxic effects in long term amiodarone treated patients. The rate of leucocytes with lamellar bodies was determined in three groups of patients. The group I was composed of 8 patients with amiodarone induced pneumonia who were taking the drug for an average of 16.88 months (average of 386.60 mg a day). The group II was composed of 19 patients not presenting any toxic effects, and who were taking amiodarone for an average of 38.32 months (average of 260.62 mg a day). The group III consisted by 8 healthy volunteers. The leucocyte layer was sampled from centrifuged peripheric blood and examined by transmission electron microscopy. The average percentage of leucocytes with lamellar bodies was 1.82 in group I, 1.65 in group II and 3.47 in group III. The lamellar inclusions were seen in all groups. There were no significant qualitative or quantitative differences between the groups. The inclusions couldn't be differentiated from other previously described non amiodarone lamellar bodies, such as artifacts and those produced by cellular degeneration. Although lamellar bodies can be observed in leucocytes of patients taking amiodarone, the determination of the rate of affected leucocytes is of no help for predicting amiodarone pulmonary toxicity.

Adult↗
PubMedDate not supplied

[Influence of the combination of theophylline and beta 2 agonists by oral route on pulmonary function of patients with chronic obstructive lung disease].

The role of the concurrent use of theophylline and beta-adrenergic agents for relief of bronchial obstruction is controversial. For this reason, we studied the lung function of 9 patients with chronic obstructive pulmonary disease, whose ages ranged from 51 to 69 (average 60.6 +/- 6.6) years, after the oral administration of theophylline and theophylline plus salbutamol. After withdrawal of all bronchodilators for 24 hours, the basal values of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were obtained. Oral slow release theophylline (600 mg/day) was then administered for 7 days, followed by 7 days of the concurrent use of the same dose of theophylline plus salbutamol (16 mg/day). Spirometry was reevaluated at the end of each week. Pretreatment FVC ranged from 0.85 to 2.57 (average 1.78 +/- 0.64) liters, FEV1 from 0.70 to 1.64 (average 1.15 +/- 0.30) liters and theophylline serum levels from 0.1 to 3.1 (average 1.81 +/- 1.01) micrograms/ml. At the end of the first week, FVC was 1.38 to 3.26 (average 2.03 +/- 0.65) liters, FEV1 0.85 to 1.73 (average, 1.40 +/- 0.29) liters and theophylline serum levels 8.1 to 21.0 (average 13.40 +/- 4.18) micrograms/ml. With the concurrent use of theophylline and salbutamol FVC ranged from 1.24 to 2.57 (average 1.90 +/- 0.50) liters and FEV1 from 0.96 to 1.90 (average 1.46 +/- 0.33) liters, values not statistically different from theophylline alone.

Administration, Oral↗
PubMedDate not supplied

[Effects of adrenergic beta 2 agonists by oral route on theophylline blood levels].

Several drugs interfere with theophylline pharmacokinetics, inducing changes on it's serum levels. With the purpose of determining a possible influence of oral administered beta-2-adrenergics agents on theophylline serum levels ten patients with bronchial obstruction, whose ages ranged from 51 to 69 (average 59.90 +/- 6.67) years, were analysed. After a period of 24 hours without any medication, the patients received 600 mg of oral slow release theophylline per day, for 7 days, followed by 7 days of the same dose of theophylline combined with 16 mg of oral salbutamol. Blood samples were drawn after the 24 hours without medication and at the 4th hour after the morning dose of theophylline, at the end of each week. The serum levels were, respectively, 2.08 +/- 1.20 micrograms/ml, 15.18 +/- 6.87 micrograms/ml and 11.45 +/- 5.15 micrograms/ml. The levels of the phase (theophylline alone) were significantly higher than those obtained after the concurrent use of theophylline and salbutamol. It can be concluded that this association interferes on theophylline pharmacokinetics. We suggest that in patients taking these drugs the serum levels of theophylline shall be measured to permit an eventual correction of the dose of theophylline being administered.

Administration, Oral↗
PubMedDate not supplied

[Pneumoconiosis in abrasive industry workers].

Occupational lung disease is uncommon in workers of abrasive industries. Twenty-two workers of these industries presenting radiological lung lesions were analysed. All were males with ages ranging from 29 to 59 years. Nineteen worked in the production of silicon carbide, three in the production of aluminum dioxide and one in both for a period of 8 to 27 years. In 20 patients the predominant radiological changes (ILO-80) were small opacities. Association of small and large opacities was observed in one case and isolated large opacities in another one. The small opacities were predominantly round and diffuse. The large opacities in both patients were classified as being of category B. It is concluded that the workers in abrasive industries are at a higher risk of developing occupational lung disease produced by silicon carbide.

Adult↗
PubMedDate not supplied

[Forced mid-expiratory flow rate (FEF 25-75%): a critical analysis of its value in recognizing diseases of the small airways].

A total of 245 patients submitted to lung function test were studied. They were divided in 2 groups: A--FEV1.0/FVC greater than or equal to 75% and B--FEF25-75% less than 75%. These groups were further subdivided according to the age of the patients--subgroup 1 less than or equal to 50 years and subgroup 2 greater than 50 years. Patients with restrictive disorders were not included. The spirometric equipment employed was Hewlett-Packard Inc. Pulmonary Function Analyzer 47402-A. The results were obtained through a digital system and calculated from a graph impressed in a xy register. Results were automatically corrected to BTPS. In each group FVC and FEV1.0 were normal. In group A FVC and FEV1.0 were, respectively: A1-99.63 +/- 13.33 and 101.11 +/- 12.24, A2-97.60 +/- 11.06 and 98.81 +/- 12.18, expressed as percentage of predicted values. In group B the results were: B1-97.61 +/- 13.55% and 81.71 +/- 14.44%; B2-100.28 +/- 13.98% and 83.10 +/- 16.42%. The differences were not statistically significant at 5%. In subgroup A1 X FEV1.0/CVF was 83.41 +/- 5.63% and in subgroup A2, 79.42 +/- 4.23%. Maximum mid-expiratory flow rate was 88.64 +/- 24.39% in subgroup A1 and 65.26 +/- 17.88% in subgroup A2. These differences were statistically significant at 1%. In group B, FEV1.0/FVC was always less than 75%. In subgroup B1 it was 68.24 +/- 10.43% and in B2, 64.90 +/- 10.43% and values for FEF25-75% were 48.13 +/- 16.48% and 42.79 +/- 17.68%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗