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.

Work Ability of Health Care Shift Workers: What Matters?

This paper aims at identifying variables associated with inadequate work ability among nursing personnel at a public hospital, considering factors related to socio-demographic, lifestyles, working conditions, and health outcomes. A cross-sectional study was conducted in a university hospital in São Paulo, Brazil, as part of a larger research study on tolerance to 12 h night work. Nursing staff included registered nurses, nurse technicians, and nurse aides; in total, there were 996 healthcare workers (878 female; 118 male) at the time of the study. Some 696 workers (69.9%) of the population agreed to participate. Data collection (October 2004-July 2005) was based on a comprehensive questionnaire about living and working conditions (including incivility at work, work demands, work control, and support), mental and physical health symptoms (fatigue and sleep problems), and work ability. This report presents analyses of the adapted Brazilian version of the Work Ability Index (WAI) and associated variables. The study population worked one of the following shift schedules at this hospital: 12 h nights followed by 36 h off or 9 h or 6 h day (morning or afternoon) shifts. The mean age of the respondents was 34.9 (S.D.+/-10.4) years of age; 31.5% of the participants held two jobs. Statistical analyses using a hierarchical multiple logistic regression model were performed to evaluate the factors associated with inadequate (moderate and low scores) of the WAI. The significantly associated factors were socio-demographic (income responsibility, sole breadwinner, raising kids, age group), working conditions (thermal discomfort, organization of the workplace, and verbal abuse), and health outcomes (high body mass index, obesity, sleep problems, and fatigue). In spite of limitations of the study design, results indicate that the nursing profession is associated with stressful working conditions, contributing to inadequate WAI. This is in addition to bad living conditions and precarious work. Intervention measures, either at the workplace or at individual levels, are necessary to prevent a decrease in work ability, even in this quite young working population.

Short sleep is associated with obesity among truck drivers

Recent studies suggest that short-sleep duration is independently associated with obesity in the general population. The population of truck drivers is of particular interest, because they frequently work irregular shifts that in turn are associated with short-sleep duration. In addition, truck drivers have a high prevalence of sedentary habits, poor diet, and obesity. The present study aimed at verifying the association between sleep patterns and factors associated with obesity in this population. The study sample consisted in 4,878 truck drivers who participated in a campaign promoted by a highway company in the State of São Paulo, Brazil. This campaign offered highway truck drivers a medical and laboratorial evaluation. The truck drivers completed a questionnaire concerning demographic data, sleep duration, consumption of medications, and medical problems, such as diabetes, cardiopathy, and hypertension; as well as the Berlin questionnaire, which is able to discriminate low and high risk for obstructive sleep apnea. Blood samples were collected to measure glucose and cholesterol levels. Also, body weight and height were registered to calculate the body mass index (BMI). The mean age (+/-SD) of the truck drivers studied was 40+/-10 years. Out of the truck drivers analyzed, 28.3% (n = 1,379) had a BMI > or =30.0 Kg/m2 (obesity). Among the 4,878 drivers included in the study, 1,199 (24.6%) were on medications and 334 (6.8%) were diabetic. Drivers (26.9%) with the greater BMI had a short sleep length. The independent factors associated with obesity were sleep duration <8 h/day (OR = 1.24), age >40 years (OR = 1.20), glucose levels >200 (OR = 2.02), cholesterol levels >240 (OR = 1.57), snoring (OR = 1.74), and hypertension (OR = 2.14). Smoking was not associated with obesity (OR = 0.69), and diabetes was considered a control variable. In conclusion, this study supports the hypothesis that short sleep duration as well as age >40 years are independently associated with obesity. This particular combination (short-sleep duration and obesity) is independently associated with several healthcare problems, including high levels of cholesterol, glucose, snoring, and hypertension. However, due to the cross-sectional nature of this study, no cause-effect relationship can be drawn from these results.

Antibiotic levels in empyemic pleural fluid

OBJECTIVE

To determine the degree to which bioactive penicillin, metronidazole, ceftriaxone, clindamycin, vancomycin, and gentamicin penetrate into empyemic pleural fluid using our new rabbit model of empyema.

METHODS

An empyema was created via the intrapleural injection of 10(8)()Pasteurella multocida bacteria into the pleural space of New Zealand white rabbits. After an empyema was verified by thoracentesis and pleural fluid analysis, penicillin, 24,000 U/kg; metronidazole, 37 mg/kg; ceftriaxone, 30 mg/kg; clindamycin, 9 mg/kg; vancomycin, 15 mg/kg; or gentamicin, 1 mg/kg, were administered IV. Antibiotic levels in samples of pleural fluid and serum, collected serially for up to 480 min, were then determined using a bioassay.

RESULTS

The degree to which the different antibiotics penetrated into the infected pleural space was highly variable. Penicillin penetrated most easily, followed by metronidazole, ceftriaxone, clindamycin, vancomycin, and gentamicin. Of the antibiotics tested, penicillin and metronidazole equilibrated the most rapidly with the infected pleural fluid. Penicillin levels remained elevated in pleural fluid even after serum levels had decreased.

CONCLUSIONS

Using this rabbit model of empyema, there was marked variation in the penetration of antibiotics into the empyemic fluid. Although there are species differences between rabbit and human pleura, the variance in degree of penetration of antibiotics into the pleural space should be considered when antibiotics are selected for the treatment of patients with empyema.

Postoperative pleural changes after coronary revascularization. Comparison between saphenous vein and internal mammary artery grafting

Coronary artery bypass grafting (CABG) is commonly performed with a saphenous vein graft (SVG) and/or an internal mammary artery graft (IMA). We hypothesized that there would be a higher incidence of pleural changes after CABG in patients who underwent IMA grafting because pleurotomy is usually performed. In the present study, the pre and the 6th postoperative day chest roentgenograms of 122 patients who received CABG were reviewed. The incidence of effusion in the patients who received only SVG was 43 percent (23/54) and did not differ significantly (p greater than 0.05) from the incidence in the patients who also had IMA 41 percent (28/68). Almost all of the patients (43/51) had unilateral left-sided pleural effusions. Most of the effusions were small and did not require treatment. The incidence of effusion was not higher in patients with enlargement of their cardiac silhouette or atelectasis and was not related to the presence of chest tubes. The incidence of pleural thickening was higher in the IMA group (49 percent) than in the SVG group (31 percent) but the difference did not achieve statistical significance (p greater than 0.05). We conclude that there is a high (approximately 40 percent) incidence of small effusions and thickening after CABG. The incidence of pleural effusion and pleural thickening do not appear to be influenced by the type of surgery (IMA vs SVG). We speculate that the effusions are due to pericardial inflammation.

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.

Arterial blood gases after coronary artery bypass surgery

Coronary artery bypass graft (CABG) surgery adversely affects arterial blood gas (ABG) determinations. The purposes of this study were to assess serial changes in ABGs following bypass surgery and identify factors that may influence these changes. Room air ABGs were obtained preoperatively and on days 1, 2, 4, 6, and 8 postoperatively on 125 patients undergoing bypass surgery. Fifty-five patients (saphenous vein grafting [SVG] group) had only SVG grafting while 70 (internal mammary artery [IMA] group) received one (60 patients) or two (10 patients) IMA grafts in addition to the SVG grafts and were subjected to pleurotomy. The mean preoperative values (+/- SD) were as follows: PaO2, 75.1 +/- 7.7 mm Hg, P(A-a)O2, 20.9 +/- 7.5 mm Hg; PaCO2, 33.6 +/- 4.1 mm Hg; pH, 7.43 +/- 0.04; hemoglobin, 14.8 +/- 1.4 g/dl; and hematocrit, 44.2 +/- 3.9 percent. There was a large decrease in the PaO2 postoperatively. The nadir for the PaO2 (55.7 +/- 6.6 mm Hg) occurred on the second postoperative day. Eight days postoperatively, there were still significant abnormalities; the PaO2 was 65.7 +/- 7.3 mm Hg, the P(A-a)O2 was 33.2 +/- 8.8 mm Hg; the hemoglobin was 10.5 +/- 1.4 g/dl; and the hematocrit was 31.7 +/- 4.0 percent. The decrease in the PaO2 was particularly noteworthy given the large decrease in the hemoglobin and hematocrit. The changes in the PaO2 were not significantly correlated with the age, number of grafts, pump time, length of anesthesia, or endotracheal intubation or smoking history. Immediately postoperatively, changes were similar in both groups (p > 0.05); on the second postoperative day, the PaO2 had decreased 26.9 percent in the SVG group and 25.5 percent in the IMA group. However, the postoperative abnormalities resolved more slowly in the IMA group (p < 0.05). These observations suggest that the additional trauma to the lungs and chest wall in the IMA group (pleurotomy, the placing of pleural drains, etc) will result in a longer recovery time in the IMA group than in SVG group.

Pulmonary function after coronary artery bypass surgery

Coronary artery bypass graft surgery (CABG) adversely affects pulmonary function tests (PFTs). Although several previous studies have addressed these changes, none has measured the forced vital capacity (FVC) on a daily basis. The purpose of the present study was to assess serial changes in the FVC following CABG and to identify factors that may influence these changes. The FVC was obtained pre- and daily postoperatively (1-10 days) in 120 patients. Fifty-one patients received saphenous vein grafts (SVG group) while 69 received at least one internal mammary artery graft in addition to SVG (IMA group). On the first postoperative day, the FVC decreased to 33% of the pre-operative value in the SVG group and to 29% in the IMA group. The spirometry gradually improved, but after 10 days, the FVC remained reduced (SVG, 70%; IMA, 60%). Although the decreases in FVC tended to be greater in the IMA group, there was no significant difference in the two groups (P = 0.27). The changes in FVC were not significantly related to age (P = 0.48), smoking history (P = 0.65), anesthesia (P = 0.38) or pump time (0.09). From this study, it is concluded that after CABG, there is a significant worsening of the pulmonary function. The nadir of FVC occurs immediately after surgery and improves gradually thereafter. However, on the tenth postoperative day, the FVC still remains more than 30% below pre-operative values. Since there is only a slight tendency for patients undergoing IMA grafting to have larger decreases in their pulmonary function, patients with ventilatory impairment should not be excluded from IMA grafting.

Relationship between pleural effusion and pericardial involvement after myocardial revascularization

The explanation for the high incidence of pleural effusion after cardiac surgery is unclear. There is a high incidence of left pleural effusion with inflammatory pericardial disease. We hypothesized that after coronary artery bypass grafting (CABG) there would be a higher incidence of pleural effusions in patients with pericardial involvement. We prospectively studied 47 patients undergoing elective CABG; 17 had only saphenous vein grafts (SVG group) and 30 received at least one internal mammary artery graft (IMA group) in addition to SVG. Patients had a chest radiograph, chest ultrasound, and an echocardiogram on the 7th, 14th, and 30th postoperative days. Seven days after the surgery, 42 to 47 patients (89.4 percent) had a pleural effusion and 36 (76.6 76.6 percent) pericardial involvement. No relationship was found between the presence of a pleural effusion and a pericardial effusion (p > 0.05). On the 14th postoperative day, 36 patients (76.6 percent) had a pleural effusion while 33 patients (70.2 percent) had a pericardial effusion. There was a significant relationship between the presence of a pleural effusion and a pericardial effusion (p < 0.05). On the 30th postoperative day, 27 patients (57.4 percent) had a pleural effusion and 25 (53.2 percent) had a pericardial effusion. Again, there was a significant relationship between a pleural effusion and a pericardial effusion (p < 0.05). Finally, there was no relationship between the ejection fraction and the presence of pleural effusion at any time (p > 0.05). From this study, we conclude that there is a high prevalence of both pleural and pericardial effusion postoperatively in patients undergoing CABG. Both types of effusions tend to be asymptomatic, gradually disappear, and are more common in the IMA group. Patients who have a persistent pericardial effusion are more likely to have a persistent pleural effusion.

Comparison of silver nitrate and tetracycline as pleural sclerosing agents in rabbits

The ideal agent to produce pleurodesis has not been identified. Tetracycline, the drug used most commonly in the 1980s, is no longer available. Talc either aerosolized or in a slurry is the agent used just most commonly at the present time, but there are concerns about its safety. Another possibility is silver nitrate, which was widely used in the past, but was abandoned on account of side effects. We hypothesized that lower concentrations of silver nitrate than had been used in the past would be effective in creating a pleurodesis in rabbits. The following medications in a total volume of 2 mL were instilled intrapleurally in three groups of ten anesthetized rabbits: 0.25% or 0.50% silver nitrate and 35 mg/kg tetracycline. Twenty-eight days after the injection, the animals were sacrificed and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The intrapleural injection of 0.50% silver nitrate produced an effective pleurodesis. The mean degree of gross pleurodesis in the rabbits that received 0.50% silver nitrate (3.4 +/- 1.2) did not differ significantly from that of the rabbits that received tetracycline (3.5 +/- 0.7) (scale 0 to 4). The mean degree of microscopic pleural fibrosis in the rabbits that received 0.50% silver nitrate (3.4 +/- 0.7) did not differ significantly from that of the rabbits that received tetracycline (3.9 +/- 0.3). However, 0.25% silver nitrate was ineffective in creating pleural fibrosis, either grossly or microscopically. No rabbits died after the intrapleural injection of the drugs. There were no observed side effects after the injection of silver nitrate. The present study demonstrates that 0.50% silver nitrate instilled into the pleural space is an effective agent for producing pleurodesis in the rabbit; its effect is comparable to tetracycline 35 mg/kg. This agent should be compared with tetracycline derivatives and talc in studies in humans.

Sleep and sleepiness among working and non-working high school evening students

The aim of this study was to evaluate patterns of sleepiness, comparing working and non-working students. The study was conducted on high school students attending evening classes (19:00-22:30 h) at a public school in São Paulo, Brazil. The study group consisted of working (n=51) and non-working (n=41) students, aged 14-21 yrs. The students answered a questionnaire about working and living conditions and reported health symptoms and diseases. For seven consecutive days, actigraphy measurements were recorded, and the students also filled in a sleep diary. Sleepiness ratings were given six times per day, including upon waking and at bedtime, using the Karolinska Sleepiness Scale. Statistical analyses included three-way ANOVA and t-test. The mean sleep duration during weekdays was shorter among workers (7.2 h) than non-workers (8.8 h) (t=4.34; p<.01). The mean duration of night awakenings was longer among workers on Tuesdays and Wednesdays (28.2 min) and shorter on Mondays (24.2 min) (t=2.57; p=.03). Among workers, mean napping duration was longer on Mondays and Tuesdays (89.9 min) (t=2.27; p=.03) but shorter on Fridays and Sundays (31.4 min) (t=3.13; p=.03). Sleep efficiency was lower on Fridays among non-workers. Working students were moderately sleepier than non-workers during the week and also during class on specific days: Mondays (13:00-15:00 h), Wednesdays (19:00-22:00 h), and Fridays (22:00-00:59 h). The study found that daytime sleepiness of workers is moderately higher in the evening. This might be due to a work effect, reducing the available time for sleep and shortening the sleep duration. Sleepiness and shorter sleep duration can have a negative impact on the quality of life and school development of high school students.

Systemic corticosteroids decrease the effectiveness of talc pleurodesis

Corticosteroids can inhibit the inflammatory process and the formation of fibrosis. The purpose of this study was to determine whether the concurrent use of steroids at the time of talc-slurry pleurodesis would influence the development of the pleurodesis. One group of rabbits received an intrapleural injection of talc (400 mg/kg) and an intramuscular injection of triamcinolone (0.8 mg/kg) 1 d before talc instillation and weekly thereafter, whereas a control group received only talc. Ten rabbits in each group were killed at 6 h and at 1, 2, 4, 7, 14, and 28 d after instillation. The mean volume of pleural fluid was significantly lower in the group receiving corticosteroids at 6 h through 4 d after talc slurry than in the other groups. The degree of pleural adhesion was significantly smaller in the group receiving corticosteroids from Day 2 through Day 28. At Day 28, all 10 rabbits that received talc only had a pleurodesis score of 3 or 4, whereas only four of the 10 rabbits that also received steroids had a pleurodesis score of 3 or 4. This study shows that the use of corticosteroids at the time of talc-slurry pleurodesis markedly decreases the inflammatory reaction to the talc, and essentially prevents a pleurodesis from developing.

Relationship between pleural changes after myocardial revascularization and pulmonary mechanics

It is known that coronary artery bypass grafting (CABG) results in impairment of postoperative pulmonary function. There is also a high incidence of pleural changes (pleural effusion or pleural thickening) after CABG. We hypothesized that those patients with pleural changes in the postoperative period would have a greater decrease in pulmonary function test (PFTs) results. The present study reports the results of 110 male patients who underwent CABG. The chest films and the PFT results obtained preoperatively and on the sixth postoperative day were reviewed. The relationship between pleural changes and PFTs was analyzed in patients who received saphenous vein graft alone (SVG group: 50 patients) or in combination with internal mammary artery grafting (IMA group: 60 patients). In the IMA group, the patients who had pleural changes had significantly greater decreases in their pulmonary function than did the patients without pleural changes. The decrease in the FVC, TLC and FEV1 in the patients with pleural effusions (37.6, 27.8 and 36.8 percent) was similar to that in patients with pleural thickening (34.6, 28.3 and 35.0 percent) and both were significantly greater (p < 0.05) than the changes in the patients with a normal radiograph (26.1, 17.6 and 26.9 percent). In the SVG group, the presence of pleural changes was not significantly related to the decrement in pulmonary function. The values of RV, FRC, Cst, and blood gases were not affected in the SVG or IMA group by the presence of pleural changes. We conclude that the presence of pleural changes on the chest radiograph is associated with a larger decrement of pulmonary function after CABG in the IMA group. This larger decrease probably reflects added thoracic trauma and is not due to the presence of pleural changes per se.

Sleep Patterns of Day-Working, Evening High-Schooled Adolescents of São Paulo, Brazil

Children who grow up in developing countries of the world must work to help financially support their families, and they must also attend school. We investigated the impact of work on the sleep of working vs. nonworking high school students. Twenty-seven São Paulo, Brazil, public high school students (eight male and eight female working students plus six nonworking female and five nonworking male students) 14-18 yrs of age who attended school Monday-Friday between 19:00 to 22:30h participated. A comprehensive questionnaire about work and living conditions, health status, and diseases and their symptoms was also answered. The activity level and rest pattern (sleep at night and napping during the day) were continuously assessed by wrist actigraphy (Ambulatory Monitoring, USA). The main variables were analyzed by a two-factor ANOVA with application of the Tukey HSD test for multiple comparisons, and the length of sleep during weekdays vs. weekends was compared by Student t-test. Working students went to sleep earlier weekends [F(1,23)=6.1; p=0.02] and woke up earlier work days than nonworking students [F(1,23) = 17.3; p = 0.001]. The length of nighttime sleep during weekdays was shorter among all the working [F(1,23)= 16.7; p <0.001] than all the nonworking students. The sleep duration of boys was shorter than of girls during weekends [F(1,23)= 10.8; p <0.001]. During weekdays, the duration of napping by working and nonworking male students was shorter than nonworking female students. During weekdays working girls took the shortest naps [F(1,23)= 5.6; p = 0.03]. The most commonly reported sleep complaint during weekdays was difficulty waking up in the morning [F(1,23) = 6.5; p = 0.02]. During weekdays, the self-perceived sleep quality of working students was worse than nonworking students [F(1,23) = 6.2; p = 0.02]. The findings of this study show that work has negative effects on the sleep of adolescents, with the possible build-up of a chronic sleep debt with potential consequent impact on quality of life and school learning.

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.

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.

Efeitos do trabalho sobre a saúde de adolescentes

O estudo analisa conseqüências do trabalho para as condições de vida, saúde e desenvolvimento psicossocial de adolescentes. Participaram do estudo 354 estudantes de 14 a 18 anos, do ensino médio, período noturno. A análise das representações foi realizada a partir da coleta de evocações livres. Os dados sobre sono foram obtidos por meio de questionários, sobre auto-percepções acerca das condições de vida e trabalho, sintomas de saúde e doenças. A análise de dados foi realizada com o software EVOC 2000 e SPSS. Constataram-se diferenças significativas na duração média de sono entre os adolescentes: os trabalhadores relataram menores médias de duração de sono. Entre os trabalhadores, referiram dormir menos os que sentem sono no trabalho e nas aulas, têm maiores exigências psicológicas no trabalho, ganham acima de 1 salário mínimo mensal, jornadas acima de 6 horas diárias ou acima de 20 horas semanais, trabalham em local barulhento e com presença de gases e vapores. As representações do trabalho entre os jovens apontam contradição entre o seu reconhecimento como valor moral positivo para o desenvolvimento psicossocial e a construção da identidade, e as conseqüências negativas decorrentes da exposição a cargas físicas e psicológicas precocemente.

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.

Futuro e liberdade: o trabalho e a instituição escolar nas representações sociais de adolescentes

Este estudo objetivou a análise das relações estabelecidas entre o trabalho do adolescente e o processo de escolarização, em duas cidades de São Paulo, apoiado na teoria das representações sociais. Foram pesquisados 778 adolescentes, trabalhadores e não trabalhadores, com idades entre 11 e 18 anos, que freqüentavam as escolas públicas das localidades, no período de 1998 a 2000. Foram realizados 18 grupos focais e a coleta de evocações livres. Para a análise de conteúdo dos grupos focais foi utilizado o software ALCESTE 4.5; as evocações livres foram analisadas a partir da teoria do núcleo central. Os resultados indicam que a relação trabalho-escola está estruturada numa relação de contradição entre as dimensões moral, de saber e das conseqüências do trabalho, permeadas pela possibilidade e pela impossibilidade de futuro. Como conclusão observou-se que, apesar do trabalho representar um risco para a escolarização, este é legitimado pelas representações dos próprios jovens, ora justificando-o, ora legitimando-o.

Transforming growth factor beta2 induced pleurodesis is not inhibited by corticosteroids

BACKGROUND

Talc and tetracyclines induce pleurodesis by directly injuring the pleura. The injury results in intense inflammation which subsequently leads to fibrosis. Corticosteroids can inhibit talc pleurodesis by reducing the inflammatory process. We hypothesised that transforming growth factor beta2 (TGFbeta2), a fibrogenic cytokine with immunomodulatory functions, could induce effective pleurodesis without generating significant pleural inflammation and therefore remain effective despite co-administration of corticosteroids.

METHODS

Thirty rabbits were divided into two groups. Rabbits in the steroid group received weekly intramuscular injections of triamcinolone diacetate (0.8 mg/kg). Ten rabbits in each group were given 5.0 microg TGFbeta2 intrapleurally via a chest tube while the remaining five received 1.7 microg TGFbeta2. Pleurodesis was graded macroscopically after 14 days from 1 (none) to 8 (>50% symphysis).

RESULTS

TGFbeta2 produced excellent pleurodesis at both 5.0 microg and 1.7 microg doses. The pleural effusions produced after the injection were low in all inflammatory markers. No significant differences were seen between the steroid group and controls in macroscopic pleurodesis scores (7.2 (1.3) v 7.1 (1.2)), levels of inflammatory markers in the pleural fluids (leucocyte 1107 (387)/mm(3) v 1376 (581)/mm(3); protein 3.1 (0.3) mg/dl v 2.9 (0.3) mg/dl, and LDH 478 (232) IU/l v 502 (123) IU/l), and the degree of microscopic pleural fibrosis and pleural inflammation.

CONCLUSIONS

TGFbeta2 can induce effective pleurodesis and remains effective in the presence of high dose parenteral corticosteroids.

Experimental Pleurodesis in Rabbits Induced by Silver Nitrate or Talc

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.

Comparison between self-reported sleep duration and actigraphy among adolescents: gender differences

INTRODUCTION

There are only few agreement studies between subjective measures of sleep and actigraphy among adolescents.

OBJECTIVE

To compare self-reported sleep and actigraphy in this age group, by studying gender differences and, using a new graphical approach, the survival agreement plot.

METHODS

Thirty-seven subjects, aged 12 to 17 years, answered questions about nocturnal sleep duration and used actigraphy for seven days. The mean and median differences between the informed sleep and the recorded one, the intraclass correlation coefficient, the Bland-Altman plot and the survival-agreement plot were used.

RESULTS

A mean difference of about one hour (SD = 2.1; median = 0.5; p < 0.01) was found between both strategies, which was higher among boys, 1.9 hours (SD = 2.8; median = 1.6; p < 0.05), than among girls, 0.5 hours (SD = 1.4; median = 0.3; p = 0.11). The graphical evaluation showed similar results, as well as the intraclass correlation coefficient: 0.06 (95%CI = -0.33 - 0.46; p = 0.489) for boys and 0.43 (95%CI = 0.12 - 0.83; p < 0.001) for girls.

CONCLUSIONS

Our data are consistent with previous studies as to non-agreement between the two methods. These results are relevant because this is the first study of concordance between subjective measures of sleep and actigraphy among Brazilian adolescents, as far as we know. In addition, they reinforce the need of a careful use of nocturnal sleep measures among adolescents, mainly among boys.

Influence of atelectasis on pulmonary function after coronary artery bypass grafting

The purpose of this study was to determine the influence of atelectasis on pulmonary function 6 days following coronary artery bypass grafting (CABG). After 6 days, 30 patients had normal chest radiographs, 38 had atelectasis, and 57 had pleural changes. In 11 patients, atelectasis only was observed in the radiograph, and in 27 it was in combination with pleural changes. The decrease in FVC and FEV1 in the patients with atelectasis was 33.4 and 33.5 percent in the SVG group and 34.8 and 34.3 percent in the IMA group, while in those patients with a normal radiograph, the decrements were 26.3 and 26.9 percent in SVG group and 26.1 and 26.9 percent in IMA group, respectively. Thus, patients with atelectasis on the 6th postoperative day have a larger decrement in pulmonary function post CABG than the patients with normal chest radiograph and this reduction reflects a higher degree of thoracic trauma.

Teen at work: the burden of a double shift on daily activities

The purpose of this study was to the evaluate time spent by working and nonworking adolescents on daily activities (work, home duties, school, transportation, other activities, leisure, sleep, and naps). Twenty-seven students, 8 male workers, 8 female workers, 5 male nonworkers, and 6 female nonworkers, ages 14-18 yrs participated in the study. They attended evening classes Monday-Friday (19:00-22:30h) in a public school in the city of São Paulo, Brazil. The students answered a comprehensive questionnaire on the characterization of their life, work, and health conditions. Simultaneously, they wore actigraphs (Ambulatory Monitoring, Inc.) and completed a diary of their daily activities (time spent at work, on home duties, commuting, leisure, other activities) for a minimum of 10 to a maximum of 17 consecutive days. The means of the variables were tested for differences by a two-factor (work and sex) ANOVA and Student-t test applied to pair-wise samples (weekdays and weekends). The average duration during weekdays of working time was 7 h 09 min and home duties 0 h 48 min. As for commuting time, there was a work effect [F(1,23) = 4.9; p = 0.04]; mean commuting time was 2 h 22 min for workers (males and females) and 1 h 25 min for nonworkers. There was a significant difference between workers and nonworkers [F(1,23) = 4.6; p = 0.04] regarding extra-cirricular class activities; workers spent a mean of 3 min/day on them as opposed to 1 h 14 min by nonworkers. The average daily time spent on leisure activities by workers was 6h 31 min; whereas, for nonworkers it was 7h 38min. Time spent in school amounted to 2h 47min for workers in comparison to 3h 22min by nonworkers. There was a significant work effect upon sleep [F(1,23)= 10.0; p <0.01]. The work effect upon nighttime sleep duration was significant [F(1,23)= 16.7; p <0.01]. Male workers showed a mean night sleep of 6 h 57 min and female workers 07h 15min. The average nighttime sleep duration for nonworkers was 9 h 06 min. There was a significant interactive effect between work and sex [F(1,23)= 5.6; p=0.03] for naps. Female workers showed took shortest nap on average (36 min; SD = 26 min), and female nonworkers the longest naps (1 h 45min; SD= 35min). Study and employment exert significant impact on the life and activities of high school students. Work affects sleep and nap duration plus the amount of time spent in school and other extra-curricular activities.