Pleural fluid tumour markers in malignant pleural effusion with inconclusive cytologic results.

BACKGROUND: The presence of tumour cells in pleural fluid or tissue defines an effusion as malignant. Cytology analysis of the pleural fluid has about 60% diagnostic sensitivity. Several tests have been proposed to improve diagnosis-among them, the concentrations of tumour markers in pleural fluid. We evaluated whether the concentrations of tumour markers in pleural fluid could improve the diagnosis of malignant pleural effusion (mpe) when cytology is doubtful. METHODS: Lymphocytic pleural fluids secondary to tuberculosis or malignancy from 156 outpatients were submitted for cytology and tumour marker quantification [carcinoembryonic antigen (cea), cancer antigen 15-3 (ca15-3), carbohydrate antigen 19-9 (ca19-9), cancer antigen 72-4 (ca72-4), cancer antigen 125 (ca125), and cyfra 21-1). Oneway analysis of variance, the Student t-test or Mann-Whitney test, and receiver operating characteristic curves were used in the statistical analysis. RESULTS: Concentrations of the tumour markers cea, ca15-3, ca125, and cyfra 21-1 were higher in mpes than they were in the benign effusions (p < 0.001), regardless of cytology results. The markers ca19-9 and ca72-4 did not discriminate malignant from benign effusions. When comparing the concentrations of tumour markers in mpes having positive, suspicious, or negative cytology with concentrations in benign effusions, we observed higher levels of cea, ca15-3, cyfra 21-1, and ca125 in malignant effusions with positive cytology (p = 0.003, p = 0.001, p = 0.002, and p = 0.001 respectively). In pleural fluid, only ca125 was higher in mpes with suspicious or negative cytology (p = 0.001) than in benign effusions. CONCLUSIONS: Given high specificity and a sensitivity of about 60%, the concentrations of tumour markers in pleural effusions could be evaluated in cases of inconclusive cytology in patients with a high pre-test chance of malignancy or a history of cancer.

Effect of temperature and storage time on cellular analysis of fresh pleural fluid samples.

OBJECTIVE: Despite the methodological variability in preparation techniques for pleural fluid cytology, it is fundamental that the cells should be preserved, permitting adequate morphological classification. We evaluated numerical and morphological changes in pleural fluid specimens processed after storage at room temperature or under refrigeration. METHODS: Aliquots of pleural fluid from 30 patients, collected in ethylenediaminetetraacetic acid-coated tubes and maintained at room temperature (21 °C) or refrigeration (4 °C) were evaluated after 2 and 6 hours and 1, 2, 3, 4, 7 and 14 days. Evaluation of cytomorphology and global and percentage counts of leucocytes, macrophages and mesothelial cells were included. RESULTS: The samples had quantitative cellular variations from day 3 or 4 onwards, depending on the storage conditions. Morphological alterations occurred earlier in samples maintained at room temperature (day 2) than in those under refrigeration (day 4). CONCLUSIONS: This study confirms that storage time and temperature are potential pre-analytical causes of error in pleural fluid cytology.

Pleural fluid cytokines correlate with tissue inflammatory expression in tuberculosis.

SETTING: A tertiary care research centre in São Paolo, Brazil. OBJECTIVE: To quantify interleukin (IL) 8, tumour necrosis factor alpha (TNF-alpha), vascular endothelial growth factor (VEGF) and transforming growth factor beta(1) (TGF-beta(1)) in pleural fluid from tuberculous patients, correlating its values with the histopathological patterns in pleural biopsies. DESIGN: Cytokines were quantified in patients with transudates secondary to congestive heart failure (n = 8) and exudates secondary to tuberculosis (TB; n = 39). In parietal pleural biopsies from TB patients, the histological patterns of the inflammatory response were quantified by morphometric analysis (stereological point-counting method). RESULTS: IL-8, TNF-alpha, VEGF and TGF-beta(1) levels were higher in TB than in transudates. A positive correlation existed between components of the fibrinoid exudative phase with pleural fluid IL-8 (R = 0.52, P = 0.004) and VEGF (R = 0.42, P = 0.0021) levels. A negative correlation existed between pleural fluid IL-8 (R = -0.37, P = 0.048) and VEGF (R = -0.44, P = 0.0015) levels with tissue components of fibroproliferation. CONCLUSION: The high pleural levels of TNF-alpha, IL-8, VEGF and TGF-beta(1) suggest the involvement of these cytokines in the TB immunological response. The positive correlation between pleural fluid IL-8 and VEGF with the components of the acute exudative phase and the negative correlation between these cytokines with the fibroproliferative components suggest a temporary inflammatory response in the pleural space.

Cytokine profile in pleural fluid and serum after lung transplantation.

BACKGROUND: Lung transplantation is the procedure of choice in several end-stage lung diseases. Despite improvements in surgical techniques and immunosuppression, early postoperative complications occur frequently. OBJECTIVE: To evaluate the pleural inflammatory response after surgery. PATIENTS AND METHODS: Twenty patients aged 18 to 63 years underwent unilateral or bilateral lung transplantation between August 2006 and March 2008. Proinflammatory cytokines interleukin (IL)-1beta, IL-6, and IL-8 and vascular endothelial growth factor in pleural fluid and serum were analyzed. For cytokine evaluation, 20-mL samples of pleural fluid and blood (right, left, or both chest cavities) were obtained at 6 hours after surgery and daily until removal of the chest tube or for a maximum of 10 days. Data were analyzed using analysis of variance followed by the Holm-Sidak test. RESULTS: All effusions were exudates according to Light's criteria. Pleural fluid cytokine concentrations were highest at 6 hours after surgery. Serum concentrations were lower than those in pleural fluid, and IL-1beta, IL-6, and IL-8 were undetectable at all time points. CONCLUSIONS: There is a peak concentration of inflammatory cytokines in the first 6 hours after transplantation, probably reflecting the effects of surgical manipulation. The decrease observed from postoperative day 1 and thereafter suggests the action of the immunosuppression agents and a temporal reduction in pleural inflammation.

Acute inflammatory response secondary to intrapleural administration of two types of talc.

Intrapleural instillation of talc has been used in the treatment of recurrent pleural effusions but can, in rare instances, result in respiratory failure. Side-effects seem to be related to composition, size and inflammatory power of talc particles. The aim of this study was to evaluate the inflammatory response to intrapleural injection of talc containing small particles (ST) or talc containing particles of mixed size (MT). 100 rabbits received intrapleural talc, 50 with ST (median 6.41 mum) and 50 with MT (median 21.15 mum); the control group was composed of 35 rabbits. Cells, lactate dehydrogenase, C-reactive protein (CRP), interleukin (IL)-8 and vascular endothelial growth factor were evaluated in serum and bronchoalveolar lavage at 6, 24, 48, 72 and 96 h. Lung histology and the presence of talc were also analysed. Statistics were performed using ANOVA and an unpaired t-test. Most of the parameters showed greater levels in the animals injected with talc than in the controls, suggesting a systemic and pulmonary response. Higher serum levels of CRP and IL-8 were observed in the animals injected with ST. Talc particles were observed in both lungs with no differences between groups. Lung cell infiltrate was more evident in the ST group. In conclusion, talc with larger particles should be the preferred choice in clinical practice in order to induce safer pleurodesis.

Evidence that mesothelial cells regulate the acute inflammatory response in talc pleurodesis.

Intrapleural instillation of talc is used to produce pleurodesis in cases of recurrent malignant pleural effusions. The mechanisms by which pleurodesis is produced remain unknown but may involve either injury or activation of the mesothelium. The aim of the current study was to assess the inflammatory response of pleural mesothelial cells to talc in an experimental model in rabbits. A group of 10 rabbits were injected intrapleurally with talc (200 mg.kg(-1)) and undiluted pleural fluid was collected after 6, 24 or 48 h for measurement of interleukin (IL)-8, vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta1. Samples of pleura were studied to assess the inflammatory infiltrate and mesothelial cell viability. The pleural fluid IL-8 concentration peaked at 6 h, whereas VEGF and TGF-beta1 concentrations increased steadily over 48 h. Immunohistochemistry for cytokeratin showed a preserved layer of mesothelial cells despite the intense inflammatory pleural reaction. In conclusion, it is proposed that the mesothelial cell, although injured by the talc, may actively mediate the primary inflammatory pleural response in talc-induced pleurodesis.

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.

Cholesterol in the separation of transudates and exudates.

The Light criteria represent the most acceptable method to separate transudates and exudates. However, approximately 10% of patients with transudates, especially those with congestive heart disease, are misdiagnosed with these criteria. To improve diagnostic accuracy, many biochemical markers have been proposed as alternatives to differentiate transudates and exudates. Cholesterol has raised particular interest because only pleural fluid is needed, which makes blood samples unnecessary and simplifies the procedure. In most clinical studies, cholesterol has been shown to be as sensitive as the Light criteria, although it is less specific. Other randomized studies are necessary to determine the real potential value of pleural-fluid cholesterol measurements. Studies of pleural-fluid cholesterol are aimed at better understanding the mechanisms by which cholesterol enters the pleural cavity and its role in diseases. The ideal cutoff point of cholesterol to differentiate transudates and exudates is still unknown. Recently, aspects of the cholesterol turnover in diseases have raised great interest. Cholesterol generated great interest after it was related to coronary artery diseases. The involvement of cholesterol in the atherosclerotic process is well known, although its importance in body cavities is still unclear.

Experimental pleurodesis in rabbits induced by silver nitrate or talc: 1-year follow-up.

STUDY OBJECTIVE: To compare the pleurodesis results from the intrapleural injection of silver nitrate and talc slurry over an observation period of 12 months in rabbits. DESIGN: Rabbits were randomized to receive 2 mL of 0.5% silver nitrate or 400 mg/kg of talc slurry in 2 mL intrapleurally. Ten rabbits in each group were killed at 1 month, 2 months, 4 months, 6 months, 8 months, 10 months, and 12 months after intrapleural injection. The degree of gross pleurodesis and the amount of microscopic pleural fibrosis and inflammation were graded on a scale of 0 to 4. RESULTS: The mean +/- SEM gross pleurodesis score in the 70 rabbits that received silver nitrate was 3.34 +/- 0.08, which was significantly higher than the score of 2.32 +/- 0.09 in the 70 rabbits that received talc. The mean gross pleurodesis score was significantly higher at each of the observation times (p < 0.05), except at 2 months, in the rabbits that received silver nitrate. The pleurodesis was distributed throughout the thorax in the rabbits that received silver nitrate, while it was only in the ventral thorax in the rabbits that received talc slurry. The gross pleurodesis scores showed no tendency to decrease during the 12-month observation period in either treatment group. The persistence of talc in the pleural space did not lead to chronic inflammatory changes because the inflammation scores were similar in both groups at all observation times. The microscopic pleural fibrosis score tended to decrease with time in the silver nitrate group but not in the talc slurry group. CONCLUSIONS: The intrapleural injection of 2 mL of 0.5% silver nitrate produces a better pleurodesis than does the intrapleural injection of 400 mg/kg of talc slurry in rabbits. The pleurodesis induced by silver nitrate persists for at least 1 year. The efficacy of silver nitrate as a sclerosing agent in humans should be evaluated.

Transforming growth factor-beta2 induces pleurodesis significantly faster than talc.

Transforming growth factor-beta2 (TGF-beta2) has recently been shown to produce effective pleurodesis in rabbits. Conventional pleurodesing agents such as talc act by inducing pleural injury, which results in acute inflammation and fibrosis. TGF-beta2 is a profibrotic cytokine capable of producing fibrosis without inducing significant pleural inflammation. We hypothesize that intrapleural administration of TGF-beta2 would (1) produce an effective pleurodesis faster; (2) stimulate more collagen deposition, and (3) induce less inflammation when compared with intrapleural injection of talc. Thirty rabbits were divided into two groups and given either TGF-beta(2) (1.7 microg) or talc slurry (400 mg/kg) via a chest tube. Five rabbits from each group were killed at Days 1, 4, and 7. Gross pleurodesis was graded from 1 (none) to 8 (complete symphysis). The microscopic pleural inflammation and fibrosis were graded from 0 to 4. Pleural thickening and the total area of collagen deposition were compared. Intrapleural injection of TGF-beta2 produced effective pleurodesis within 7 d (median pleurodesis score = 7 at Day 7). At Day 7, TGF-beta2 induced significantly more collagen deposition (19.4 +/- 19.6% versus 4.6 +/- 2.9% of total area of pleura at Day 7), higher pleural fibrosis score (3.0 +/- 1.0 versus 1.8 +/- 0.5), and pleural thickness (286 +/- 191 versus 85 +/- 37 microm) than did talc. There was no difference in the degree of pleural inflammation between the two groups at Day 7 (2.6 +/- 0.9 for TGF-beta2 versus 2.4 +/- 0.6 for talc) or at any other time points. In conclusion, the intrapleural administration of TGF-beta2 produced excellent pleurodesis in rabbits at a rate faster than talc slurry and all other pleurodesing agents investigated before. TGF-beta2 stimulated more collagen deposition without inducing excess inflammation when compared with talc slurry. TGF-beta2 may have advantages over talc slurry in the management of recurrent pleural effusion and pneumothorax.

Thoracoscopy talc poudrage : a 15-year experience.

OBJECTIVES: To review our experience with thoracoscopy and talc poudrage during the previous 15 years with regards to efficacy, side effects, morbidity, and mortality. METHODS: Six hundred fourteen consecutive patients (58.6% female; mean age, 54.5 years) underwent thoracoscopy with talc poudrage from August 1983 to May 1999. Of these, 457 patients had malignant pleural effusions, 108 patients had benign pleural effusions, and 49 patients had spontaneous pneumothorax. RESULTS: Sixty-four patients were excluded from evaluation for efficacy: 30 patients (4.9%) because the lung did not expand at the time of the procedure and 34 patients (5.5%) because they died within 30 days of the thoracoscopy. All exclusions were in the malignant group. The overall success rate of the 393 patients with malignant pleural effusions was 93.4%, while the overall success for the 108 patients with benign effusions was 97%, although 7 patients (7%) with benign effusions required a second thoracoscopy. The success rate with pneumothorax was 100%. Major morbidity included empyema in 4%, reexpansion pulmonary edema in 2.2%, and respiratory failure 1.3%. CONCLUSION: Thoracoscopy with talc poudrage is effective in producing a pleurodesis in malignant and benign pleural effusion and in spontaneous pneumothorax. However, it should be noted that the insufflation of talc has a systemic distribution associated with a low rate of morbidity and perhaps does induce ARDS, which is sometimes fatal in a small percentage of patients. Because of these side effects, the search for a better agent should be continued.

Relationship between pleural fluid and serum cholesterol levels.

INTRODUCTION: Since the criteria of Light and colleagues for differentiating transudates and exudates were described, other tests, including the pleural fluid (PF) cholesterol test, have been proposed for the same purpose. However, the factors influencing PF cholesterol levels have not been clearly delineated. PURPOSE: To analyze the relationships among total cholesterol (CHOL), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides (TRIG) in serum (S) and PF. METHODS: PF and S from 99 patients (transudates, 13 patients; exudates, 86 patients) were analyzed for CHOL, HDL, LDL, TRIG, apolipoprotein AI, apolipoprotein B, and protein. The relationship between the PF and S level for each of these measurements was analyzed with linear regression and multiple regression using the ratio of PF to S protein for that measurement as a second independent variable. RESULTS: This study demonstrated that CHOL levels in PF are related to S cholesterol levels and to the permeability of the pleura (r = 0.88; p < 0.001). However, the percentage of CHOL associated with LDL and HDL (56%) in the PF was much lower than that associated with LDL and HDL in S (93%), suggesting that lipoproteins are modified once they enter the pleural space. The PF TRIG was not closely related to its S level or to the PF/S protein ratio (r = 0.49). CONCLUSION: PF cholesterol levels can be closely predicted from the S cholesterol levels and the permeability of the pleura, as reflected by the ratio of PF protein to S protein. Therefore, the CHOL ratio should not provide additional information to that provided by the protein ratio when trying to differentiate transudates from exudates. PF lipoproteins (LDL and HDL) undergo metabolic alterations once they enter the pleural space. PF TRIG levels are not closely related to S levels or to the permeability of the pleura.

Silver nitrate is superior to talc slurry in producing pleurodesis in rabbits.

STUDY OBJECTIVE: The ideal agent for producing pleurodesis has not been identified. Although talc is the agent most commonly used at the present time, there are concerns about its safety. Silver nitrate is a possible alternative agent. The purpose of the present study was to compare the effectiveness of intrapleural silver nitrate and talc slurry in producing pleurodesis in rabbits. Additionally, the total amount of pleural collagen and the distribution of thick and thin collagen fibers were studied. DESIGN: Two groups of 10 rabbits received either 0.50% silver nitrate or 400 mg/kg talc in a total volume of 2 mL intrapleurally. The animals were killed 28 days after injection, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of inflammation and fibrosis. Collagen was assessed with the van Gieson's and picrosirius stains. RESULTS: The macroscopic pleurodesis (scale, 0 to 4; mean +/- SEM) resulting from the intrapleural injection of silver nitrate (3.4+/-0.2) was significantly better (p<0.001) than that resulting from talc (1.6+/- 0.1). The mean degree of microscopic pleural fibrosis induced by silver nitrate (3.3+/-0.3) was significantly higher (p = 0.003) than that induced by talc (1.8+/-0.1). The mean amount of microscopic pleural collagen (van Gieson's) was significantly greater (p<0.001) in the rabbits that received silver nitrate (3.0+/-0.2) than in those that received talc (1.6+/-0.2). The distribution of thick and thin collagen fibers did not differ between the groups. CONCLUSIONS: We conclude that, in our rabbit model, intrapleural silver nitrate was more effective than talc in producing a pleurodesis.

A new look at old agents for pleurodesis: nitrogen mustard, sodium hydroxide, and silver nitrate.

In this review we analyze the evolution of pleurodesis. In spite of the fact that this procedure started in the beginning of the 20th century, the ideal sclerosing agent is not yet known. Emphasis is placed on the current tendency toward minimally invasive procedures in which insertion of catheters is favored over surgical procedures such as placement of chest tubes or thoracoscopy. Among the sclerosing agents, talc is preferred throughout the world. However, the possible development of acute respiratory distress syndrome, which is sometimes fatal, caused the awakening of interest in other drugs. Nitrogen mustard induces pleurodesis but causes important side effects. Sodium hydroxide and silver nitrate are effective and may be used in humans beings.

Systemic distribution of talc after intrapleural administration in rats.

STUDY OBJECTIVES: Many reports have shown the efficacy of talc to induce an effective pleurodesis. However, there is little information about the side effects related to this sclerosing agent. The objective of this experimental study is to recognize the systemic distribution of talc after its instillation into the pleural space of rats. DESIGN: Forty animals were assigned to receive talc through a catheter placed in a left minimal thoracotomy. They were randomly divided in two groups: group 1 received 20 mg of talc and group 2 received 10 mg in the same total volume of 1 mL of saline solution. Half of the animals in each group were killed 24 h and the other half 48 h after the procedure. BAL was collected and histologic sections of both lungs, chest wall, liver, kidneys, spleen, heart, and brain were examined. Crystals were tracked using polarized light and we have used a "birefringent particles index of deposition" in an attempt to quantify the amount or talc encountered in different organs. RESULTS: Talc crystals were found in every organ of all animals studied (100%). There was no statistical difference either on the dose of talc used or in the time of death. The amount of talc was statistically different in the organs, which made us divagate about a route of absorption. CONCLUSIONS: We conclude that there is a progressive deposition of talc particles in the organs examined after its administration into the pleural space of normal rats. This report suggests that there is a rapid absorption of talc through the pleural surface and that the systemic distribution thereafter is not dose related. Further studies are necessary to assess the amount of crystals and the clinical correlation to these findings.

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.

Effectiveness of ethanolamine oleate as a pleural sclerosing agent in rabbits.

The ideal pleural sclerosing agent should be easily administered, without significant side effects, inexpensive, and widely available. None of the agents presently used meets all of these criteria. Ethanolamine oleate (ETH) is a sclerosing agent used in the sclerotherapy treatment of varicose veins of the legs and esophagus. The objective of the present study was to assess the efficacy of ETH as a pleural sclerosant in rabbits. An additional objective was to assess if better results were obtained when dextrose 50% (D50) as opposed to saline was used as the diluent. Each group of 10 rabbits received a total volume of 2 ml intrapleurally. The eight treatments were as follows: (1) 2 ml saline; (2) 2 ml D50; (3) 25 mg ETH plus 1.5 ml saline; (4) 25 mg ETH plus 1.5 ml D50; (5) 50 mg ETH plus 1.0 ml saline; (6) 50 mg ETH plus 1 ml D50; (7) 75 mg ETH plus 0.5 ml D50, and (8) 100 mg ETH. The rabbits were sacrificed 28 days after the injection. The intrapleural instillation of ETH resulted in evident pleurodesis, which was dose-dependent; 100 mg ETH induced significantly (p<0.05) more adhesions than did any other treatment. The selection of the diluent had no effect on the pleurodesis. The microscopic examination of the right visceral pleura showed that the mean degree of fibrosis after 100 mg ETH was significantly (p<0.05) greater than that after the other solutions. The mean degree of pleural inflammation, lung inflammation and lung fibrosis was minimal in all the groups. From this study we conclude that undiluted ETH produces pleurodesis in our experimental model. At the doses used, the pleurodesis was less than that produced after talc, tetracycline derivatives or silver nitrate in the same model.

[Cardiopulmonary exercise testing for evaluation of muscle diseases]. / Teste de esforço cardiopulmonar na avaliação de doenças musculares.

PURPOSE: To evaluate the cardiopulmonary exercise testing (CPX) for the diagnosis of myopathies. METHODS: 27 patients with myopathy were submitted to CPX testing (symptom limited bike protocol). RESULTS: Dystrophic patients and patients with mitochondrial disease, compared with controls, showed significant differences for the power of work perfomed (watt) and the maximum oxygen consumption (VO2 max). Patients with mitochondrial disease presented significantly lower values of anaerobic threshold when compared to controls and elevation of exercise peak respiratory exchange ratio (RER) values when compared to the others groups. CONCLUSIONS: CPX testing may be useful in evaluating degree of physical limitation of patients with myopathy at inicial stage as well on follow-up examinations. Power of work performed, VO2 max, anaerobic threshold and RER at exercise peak may suggest the diagnosis of myopathy and its sub-types and therefore exclude psychologic causes of limitation.

Acute and chronic pleural changes after the intrapleural instillation of mitoxantrone in rabbits.

A previous study demonstrated that the intrapleural injection of 2 mg/kg mitoxantrone in rabbits resulted in a degree of pleurodesis which is comparable to that seen after 35 mg/kg tetracycline but that the animals had a high mortality rate after this dose of mitoxantrone. The objective of the present study was to assess the acute pleural fluid findings, the acute gross and microscopic pleural findings, and the chronic gross and microscopic findings in rabbits that received mitoxantrone. Mitoxantrone, 1.5 mg/kg, was instilled intrapleurally in 70 lightly anesthetized male rabbits. Groups of rabbits were sacrificed 1, 2, 4, 7, 15, 28, and 60 days after the injection. The intrapleural injection of mitoxantrone resulted in an exudative effusion on day 1. The pleural fluid contained predominantly neutrophils and had a mean lactate dehydrogenase (LDH) level that exceeded 4,000 IU/liter. Over the following week the volume of fluid diminished, the predominant cell became the macrophage, and the LDH levels decreased to less than 400 IU/liter. Macroscopic examination of the pleural space revealed that the mean degree of pleurodesis increased progressively over the 60-day observation period. With microscopy, the mean degree of pleural fibrosis also increased progressively. There were also substantial fibrosis and inflammation of the underlying lung and the contralateral lung. The mortality rates were low in the first 28 days (3/70) but subsequently increased and exceeded 80% in the period between 60 and 120 days. This experimental model of pleurodesis should be useful in future studies directed toward uncovering the mechanisms of pleurodesis.