Value OF CT-Guided Fine Needle Aspiration in Solitary Pulmonary Nodules with Negative Fiberoptic Bronchoscopy

The usefulness of fine needle aspiration (FNA) with CT-guidance was evaluated in the diagnosis of solitary pulmonary nodules (SPN) following negative fiberoptic bronchoscopy in 84 patients. The records were analyzed for all patients with SPN who had undergone chest FNA in the years 1988 to 1990, showing previous nondiagnostic fiberoptic bronchoscopy. A final diagnosis was made by biopsy (transbronchial, thoracotomy or necropsy), response to therapy or follow-up of the lesions. The patients had medium-sized lesions, 2.87 ± 1.11 cm, adherent to the pleura in 62%. In the diagnosis of malignancy FNA showed 76% sensitivity, 100% specificity, 100% positive predictive value, 52% negative predictive value and 81% accuracy. These results were correlated with histology in 84% of the cases. One pulmonary hemorrhage, which resolved spontaneously, and 12 cases of pneumothorax, requiring a thoracic tube in 4 patients, were noted.

Amino acid determination in some edible Mexican insects

The amino acid contents of edible insects from different provinces of Mexico and reference proteins were analysed by reversed-phase high-performance liquid chromatography and ion exchange chromatography. The insect amino acid contents were higher than the adult requirements indicated by the WHO/FAO pattern.

Measurements of Tan's contact in an atomic Bose-Einstein condensate

A powerful set of universal relations, centered on a quantity called the contact, connects the strength of short-range two-body correlations to the thermodynamics of a many-body system with zero-range interactions. We report on measurements of the contact, using rf spectroscopy, for an (85)Rb atomic Bose-Einstein condensate (BEC). For bosons, the fact that contact spectroscopy can be used to probe the gas on short time scales is useful given the decreasing stability of BECs with increasing interactions. A complication is the added possibility, for bosons, of three-body interactions. In investigating this issue, we have located an Efimov resonance for (85)Rb atoms with loss measurements and thus determined the three-body interaction parameter. In our contact spectroscopy, in a region of observable beyond-mean-field effects, we find no measurable contribution from three-body physics.

Bragg spectroscopy of a strongly interacting 85Rb Bose-Einstein condensate

We report on measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate. A magnetic-field Feshbach resonance is used to tune atom-atom interactions in the condensate and to reach a regime where quantum depletion and beyond mean-field corrections to the condensate chemical potential are significant. We use two-photon Bragg spectroscopy to probe the condensate excitation spectrum; our results demonstrate the onset of beyond mean-field effects in a gaseous Bose-Einstein condensate.

Tunable miscibility in a dual-species Bose-Einstein condensate

We report on the observation of controllable phase separation in a dual-species Bose-Einstein condensate with 85Rb and 87Rb. Interatomic interactions between the different components determine the miscibility of the two quantum fluids. In our experiments, we can clearly observe immiscible behavior via a dramatic spatial separation of the two species. Furthermore, a magnetic-field Feshbach resonance is used to change them between miscible and immiscible by tuning the 85Rb scattering length. The spatial density pattern of the immiscible quantum fluids exhibits complex alternating-domain structures that are uncharacteristic of its stationary ground state.

Noninvasive measurement of the maximum relaxation rate of inspiratory muscles in patients with neuromuscular disorders

BACKGROUND

Slowing of inspiratory muscle relaxation has been used as an index for inspiratory muscle fatigue. However, maximum relaxation rate measured from oesophageal pressure traces after maximum sniff (P(oes) MRR) has limited clinical usefulness because it requires an oesophageal balloon catheter system.

OBJECTIVES

It was the aim of this study to establish whether, in neuromuscular patients, maximum relaxation rate assessed from sniff nasal pressure (P(nasal) MRR) reflects oesophageal MRR and the tension-time index of the diaphragm (TT(di)).

METHODS

Twenty patients with neuromuscular disease and 10 healthy subjects were studied. P(oes) and transdiaphragmatic pressure were measured while P(nasal) was recorded with a balloon advanced through the nose into the nasopharynx. Maximum P(oes), transdiaphragmatic pressure and P(nasal) were simultaneously measured while the patients performed maximal sniffs. The MRR (% pressure fall/10 ms) for each sniff, the TT(di) and the tension-time index of respiratory muscles were determined.

RESULTS

Neuromuscular patients showed higher TT(di), lower P(oes) MRR and lower P(nasal) MRR than the control group. In patients with neuromuscular disease, the correlation coefficient of P(nasal) MRR and P(oes) MRR was 0.985 (p < 0.001). Regression analysis showed that P(oes) MRR = -1.101 + 1.113.P(nasal) MRR (r(2) = 0.929, standard error of the estimate = 0.208). Indeed, P(nasal) MRR was negatively correlated with TT(di) (r = -0.914, p < 0.001) and the tension-time index of respiratory muscles (r = -0.732, p < 0.001). In the neuromuscular group, the mean difference between P(nasal) MRR and P(oes) MRR was 0.286 +/- 0.217%/10 ms.

CONCLUSIONS

P(nasal) MRR obtained from a maximal sniff accurately reflects P(oes) MRR and TT(di) in patients with neuromuscular disorders.

Spirometric reference equations for European females and males aged 65-85 yrs

The aim of this study was to describe spirometric reference equations for healthy never-smoking European adults aged 65-85 yrs and to compare the predicted values of this sample with those from other studies including middle-aged and/or older adults. Reference equations and normal ranges for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory volume in six seconds (FEV6), FEV1/FVC ratio and FEV1/FEV6 ratio were derived from a healthy subgroup of 458 subjects aged 65-85 yrs. Spirometry examinations followed the 1994 American Thoracic Society recommendations and the quality of the data was continuously monitored and maintained. Reference values and lower limits of normal were derived using a piecewise polynomial model with age and height as predictors. The reference values of FEV1 and FVC from the present study were higher than those given by prediction equations from the European Community for Coal and Steel. By contrast, use of prediction equations from Caucasian-American elderly subjects (Cardiovascular Health Study) consistently overpredicted FVC and FEV1 in females by 8.5 and 2.1%, respectively. In males, equations from the Cardiovascular Health Study overpredicted FVC by 2.8%, whilst underpredicting FEV1 by 2.5%. In conclusion, these results underscore the importance of using prediction equations appropriate to the origin, age and height characteristics of the subjects being studied.

Usefulness of bronchial reactivity analysis in the diagnosis of bronchial asthma in patients with bronchial hyperresponsiveness

We examined the usefulness of some bronchial reactivity indices to identify bronchial asthma in patients with airway hyperresponsiveness. Eighty-eight consecutive patients with positive response to histamine bronchial challenge (> or = 20% fall in FEV1) were included in the study. Dose-response curves were characterised by their sensitivity (PD20) and reactivity. Dose-response slope, continuous index of responsiveness (CIR) and bronchial reactivity index (BRI) with respect to baseline and post-diluent baseline values were determined as reactivity indices. The clinical diagnosis remaining in the case history 2 years after the bronchial challenge was considered the definitive diagnosis. Asthmatic patients had higher baseline BRI (12.121+/-0.412 vs. 11.615+/-0.201; P<0.001) and post-diluent baseline BRI (12.054+/-0.368 vs. 11.563+/-0.531; P = 0.003) than other subjects. Area beneath their receiver operating characteristic (ROC) curve was 82.68% (standard error: 0.77) for the baseline BRI and 81.73 (standard error: 0.76). By multiple logistic regression analysis, baseline BRI was the only independent variable identified as a predictor for diagnosis of bronchial asthma (r = 0.387, P = 0.0007). A cut-off of 11.76 for baseline BRI reached an 87.2% sensitivity and an 80% specificity for bronchial asthma diagnosis. In conclusion, BRI calculated with respect to baseline FEV1 should be useful in identifying asthmatic patients among subjects with airway hyperresponsiveness.

Inspiratory neural drive response to hypoxia adequately estimates peripheral chemosensitivity in OSAHS patients

The aim of the present study was to examine the relationships between the responses to progressive isocapnic hypoxia and hypoxic withdrawal test in patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS) and to analyse the determinants of carotid body sensitivity in OSAHS. Nineteen consecutive OSAHS patients and 13 healthy subjects were selected. Ventilatory (delta V'I/Sa,O2/BSA) and inspiratory neural drive (delta P0.1/Sa,O2) responses to progressive isocapnic hypoxia were determined. Peripheral chemosensitivity was evaluated by the hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% oxygen (%delta V'I). Withdrawal response and ventilatory and inspiratory neural drive responses to hypoxia were lower in OSAHS patients than in control subjects. In patients with OSAHS, %delta V'I correlated significantly with delta V'I/Sa,O2/BSA and with delta P0.1/Sa,O2. On stepwise multiple linear regression analysis, a strong correlation between %delta V'I and delta P0.1/Sa,O2 was found. Moreover, %delta V'I, delta V'I/Sa,O2/BSA and delta P0.1/Sa,O2 were significantly correlated with minimum arterial oxygen saturation and with arousal index. Obstructive sleep apnoea-hypopnoea syndrome patients have a strong relationship between peripheral chemosensitivity and respiratory response to hypoxia, suggesting that hypoxic stimulation of central chemoreceptors is minimally relevant in obstructive sleep apnoea-hypopnoea syndrome. Moreover, sensitivity of the carotid body in patients with obstructive sleep apnoea-hypopnoea syndrome is related to sleep disruption and to nocturnal hypoxia.

Reduction of lung distensibility in acromegaly after suppression of growth hormone hypersecretion

Whether the growth of the lungs in acromegaly is due to alveolar hypertrophy or alveolar hyperplasia is a subject of debate. To discriminate these hypotheses, we compared pulmonary distensibility and diffusing capacity among 11 patients with active acromegaly and 11 matched control subjects, evaluating the response of pulmonary distensibility and diffusing capacity to suppression of growth hormone (GH) hypersecretion. We performed lineal and exponential analyses of quasistatic pressure-volume curves. Patients with active acromegaly had a greater TLC, lung compliance, and shape constant, K, than did normal subjects. We found no significant differences between the study groups in carbon monoxide diffusing capacity or diffusing capacity per unit of alveolar volume. After treatment, patients with inactive acromegaly showed a reduced TLC (6.95 +/- 1.40 [mean +/- SD] L versus 6.35 +/- 1.23 L), reduced lung compliance (3.61 +/- 0.90 L/kPa versus 2.36 +/- 0.79 L/ kPa), reduced K coefficient (2.62 +/- 0.65 kPa(-)(1) versus 1.35 +/- 0.40 kPa(-)(1)), and increased maximal recoil pressure (1.74 +/- 0.38 kPa versus 2.28 +/- 0.25 kPa). We conclude that the increased lung distensibility with normal diffusion capacity demonstrated in patients with active acromegaly, which was partly reversible after suppression of GH hypersecretion, suggests that lung growth in acromegaly may result from an increase in alveolar size.

A bibliometric evaluation of European Union research of the respiratory system from 1987-1998

This study analyses the evolution of the bibliometric indicators of productivity and repercussion of European Union (EU) research into the respiratory system during the period from 1987-1998, describing the geographical distribution. Using MedLine, a selection was made of those articles by EU authors published between 1987-1998 in 38 respiratory system journals (classification from the Institute for Scientific Information). The journals, country of origin, number of articles and the relation to socioeconomic data, productivity index, visibility index, expected impact factor (EIF) and relative impact factor (RIF) were all analysed. The number of EU publications in respiratory system journals experienced an exponential increase, going from 606 articles (14.3% of world production) in 1987, to 2,325 (33.2%) in 1998. During this same period, the EIF increased from 1,258 to 2,111. The greatest gross productivities were those of the UK, France, Italy and Germany, although when corrected for number of inhabitants, Sweden, the Netherlands, Belgium and Denmark headed the list. The countries with the greatest mean EIF were the Netherlands, the UK, Spain and Belgium. In conclusion, productivity and repercussions of European Union research of the respiratory system experienced an important increase during this period.

Maximal respiratory pressures in myasthenia gravis. Relation to single fiber electromyography

OBJECTIVES

The respiratory muscle weakness was evaluated in mild forms of myasthenia gravis (MG) and was compared with single fiber electromyography results (SFEMG) in the extensor digitorum communis muscle.

MATERIAL AND METHODS

We assessed 61 treated MG patients without clinical respiratory involvement (13 ocular forms, 28 form IIa and 20 form IIb patients) by maximal respiratory pressure (MRP) to ascertain whether they were consistent with SFEMG results.

RESULTS

Maximal expiratory pressure (MEP) and maximal inspiratory pressure (MIP) were reduced below the lower limit for healthy subjects in 85% and 77% of ocular patients; in 93% and 89% of form IIa, respectively; and in 95% of form IIb. The highest percentage of MEP and MIP reduction showed a positive correlation with increased jitter (r=0.45, P<0.001; r=0.27; P<0.05 respectively) and impulse blocking (r=0.35, P<0.01; r=0.28, P<0.05 respectively).

CONCLUSION

We consider MRP measure useful for assessing respiratory muscle weakness in MG patients with subclinical respiratory involvement.

Sleep apnea and hypertension

STUDY OBJECTIVES

To examine the central inspiratory drive response to hypoxia in patients with obstructive sleep apnea (OSA), according to their circadian BP profile, and in healthy control subjects. Another objective was to evaluate the relationships among sleep architecture, hypoxic sensitivity, urinary catecholamine excretion, and BP in OSA patients.

PATIENTS AND INTERVENTIONS

Polysomnography, 24-h ambulatory BP recording, and urinary excretion of catecholamines were simultaneously examined in 24 consecutive OSA patients and 11 healthy subjects. OSA patients were categorized as being normotensive (type 1), having BP elevation only during sleep (type 2), and as being hypertensive with elevated BP at all times (type 3). The response of mouth occlusion pressure at 0.1 s after onset (P(0.1)) to progressive isocapnic hypoxic stimulation was measured.

RESULTS

There was a significant difference in the P(0.1) response to hypoxia among control subjects ([mean +/- SD] 0.353 +/- 0.129 cm H(2)O/%) and type 1 (0.228 +/- 0.062 cm H(2)O/%), type 2 (0. 345 +/- 0.106 cm H(2)O/%), and type 3 (0.508 +/- 0.118 cm H(2)O/%) OSA patients. In OSA patients, chemosensitivity was related to the apnea-hypopnea index and to the nocturnal excretion of epinephrine. Significant relationships between the nocturnal excretion of epinephrine and BP were noted. On multiple linear regression analysis, the P(0.1) response to hypoxia was the only variable significantly related to diurnal (r(2) = 0.364; p = 0.005) and nocturnal mean BP (r(2) = 0.461; p = 0.002).

CONCLUSION

The findings of the present study suggest a possible mediating role of the peripheral chemosensitivity in the association between sleep apnea and hypertension.

[An evaluation of new prevention programs for tuberculous infection. II. BCG vaccination]

Tuberculosis is an infectious disease produced by Mycobacterium tuberculosis in a 98-99% of the cases and by Mycobacterium bovis in a 1-2%. Its early diagnosis is of a great importance because permits to reduce the transmission of the infection. Until now, the diagnostic techniques used to discover the dissemination of the disease are indirect. We have the PPD skin test and, among them, Mantoux is the most common. Correctly used it has a great diagnostic and epidemiological value, because it permits to evaluate those patients who can obtain a benefit with the chemoprophylaxis when the skin test is positive. We analyse the actual via of chemoprophylaxis, when and how it must be used. We study not only the drugs for the prophylaxis, but also the good and bad utilisation of the BCG vaccine, that it starts to have its indications in other countries.

[Evaluation of new programs to prevent tuberculosis infection. I. Chemoprophylaxis]

Tuberculosis is an infectious disease produced by Mycobacterium tuberculosis in a 98-99% of the cases and by Mycobacterium bovis in a 1-2%. Its early diagnosis is of a great importance because permits to reduce the transmission of the infection. Until now, the diagnostic techniques used to discover the dissemination of the disease are indirect. We have the PPD skin test and, among them, Mantoux is the most common. Correctly used it has a great diagnostic and epidemiological value, because it permits to evaluate those patients who can obtain a benefit with the chemoprophylaxis when the skin test is positive. We analyse the actual via of chemoprophylaxis, when and how it must be used. We study not only the drugs for the prophylaxis, but also the good and bad utilisation of the BCG vaccine, that it starts to have its indications in other countries.

Nocturnal arterial oxygen desaturation secondary to a sphenoidal meningioma

We report the case of a nonobese and nonsmoking 51-year-old man with nocturnal arterial oxygen desaturation that returned to normal after sphenoidal meningioma resection. He presented an important daytime hypersomnia and episodes of nocturnal apnea, without snoring. His arterial blood gases, mechanical properties of the respiratory system pulmonary diffusing capacity and chemosensitivity were normal. The most frequent causes of nocturnal hypoxemia are examined.

Regulation of breathing and perception of dyspnea in healthy pregnant women

STUDY OBJECTIVE

To examine if the perception of dyspnea during normal pregnancy may be related to an inappropriate ventilatory response to the increased metabolic rate, due to a higher chemosensitivity.

PATIENTS AND INTERVENTIONS

At weeks 12, 24, and 36 of gestation and 4 months after delivery, 11 healthy pregnant women with dyspnea and 12 asymptomatic pregnant women were studied. Progesterone plasma levels, lung volumes, diffusion capacity, maximal respiratory pressures, rest oxygen uptake, breathing pattern, and mouth occlusion pressure (P0.1) were measured. Progressive isocapnic hypoxic stimulation and progressive hyperoxic hypercapnic stimulation were performed.

RESULTS

Oxygen ventilation equivalent during pregnancy was significantly higher for the dyspneic group than for nondyspneic pregnant women. Dyspneic patients exhibited greater minute ventilation, tidal volume, and P0.1 than the nondyspneic group. The mean values of ventilatory and P0.1 slopes to hypoxia and CO2 during pregnancy were significantly greater in the patients with dyspnea than in asymptomatic subjects. These changes were not due to differences in progesterone plasma levels. A significant relation among the Borg score, inspiratory drive, and chemosensitivity was found.

CONCLUSIONS

In some pregnant women, a higher sensitivity to CO2 and hypoxia may induce excessive ventilation to metabolic demand, which would contribute to dyspnea.

The use of mouth occlusion pressure to evaluate the effect of an initial inhalation of nebulized saline in methacholine challenge

BACKGROUND

In spite of standardization of bronchial provocation tests, some methodological aspects yet are controversial. The role of saline solution inhalation is questionable. The measurement of mouth occlusion pressure 0.1 seconds after the onset of inspiration (P0.1) is a good means of detecting a response from bronchoprovocation tests.

OBJECTIVE

We investigated the value of an initial challenge with nebulized saline in subjects undergoing methacholine challenge.

METHODOLOGY

Eighty-four consecutive patients clinically suspected of bronchial asthma were studied. Bronchial methacholine challenge was performed by Chatham method. P0.1 before and three minutes after saline solution inhalation were determined by the method of Whitelaw.

RESULTS

There was no significant P0.1 change following the inhalation of the initial dose of nebulized saline either in those subjects who went on to produce a 20% decrement in FEV1 following a standardised methacholine challenge test, or in those subjects who proved to be non-reactors.

CONCLUSIONS

We shown that no modifications are present in respiratory center function when it is assessed by measurement of mouth occlusion pressure after saline solution inhalation in methacholine challenge. This may be another reason why saline solution challenge should be omitted from bronchoprovocation challenge.

Value of the peak expiratory flow in bronchodynamic tests

OBJECTIVE

To determine the accuracy of the peak expiratory flow (PEF) as an alternative parameter to the forced expiratory volume at first second (FEV1) in the bronchodynamic tests.

METHODOLOGY

We studied 84 patients, 53 males and 31 females, with average age 46 +/- 13 years, as clinic suspects of bronchial asthma. PEF was determined with a "mini-Wright peak flow meter" and a spirometry was obtained. Based on the results, 44 subjects were classified under group 1 (FEV1/FVC < 70% and FEV1 < 80% of theoretic value) and subjected to a bronchodilator test. While in group 2 subjects (normal spirometry), a methacholine challenge was performed. During each procedure, PEF readings were obtained before FEV1 determination. The usefulness of the PEF for the diagnosis of reversibility or bronchial obstruction with respect to the FEV1 was assessed in both groups.

RESULTS

In the bronchodilator tests, a cut-off point was found for the increase in the PEF > 18%, which showed a sensitivity of 85%, specificity of 79%, positive predictive value of 77% and negative predictive value of 86%, with respect to an increase in the FEV1 > 15%. In the methacholine challenge, a decrease in the PEF > 12% only achieved a sensitivity of 74% and specificity of 71%.

CONCLUSION

Peak expiratory flow may be an useful parameter in bronchodilator tests. However, it should not be used in methacholine challenge.

Use of spirometry to predict risk of pneumothorax in CT-guided needle biopsy of the lung

OBJECTIVE

Our goal was to assess the usefulness of spirometry to estimate the risk of pneumothorax in patients undergoing percutaneous needle biopsy with CT guidance for solitary pulmonary nodule (SPN).

MATERIALS AND METHODS

We studied the results of 51 consecutive percutaneous needle biopsies with CT guidance for SPN obtained between 1988 and 1990. Forty-five men and six women, aged 65 +/- 11 (36-86) years, were included in the study. All biopsies were performed under CT guidance, with 90 mm 25G needles (0.5 mm thickness) fitted into luer-type syringes. The number of needle pass attempts never exceeded three. A spirometry before biopsy was performed in all patients.

RESULTS

Pneumothorax occurred in only 10 cases (19%). The patients with pneumothorax showed lower lesion size, forced vital capacity (FVC), forced expiratory volume (FEV1), and FEV1/FVC ratio. The contribution of these factors to pneumothorax was analyzed by a logistic regression model. The FEV1 was most strongly associated with the incidence of pneumothorax. We developed an equation for predicting the risk of this complication.

CONCLUSION

We conclude that decreasing FEV1 is associated with a higher pneumothorax rate.

Six cases of pulmonary alveolar proteinosis: presentation of unusual associations

We report the cases of six patients with pulmonary alveolar proteinosis (PAP). Four of the patients were adults, two males and two females (mean age 39 +/- 19 yrs). The other two patients were children, both females, one aged 6 years and one 3 days old. The diagnosis was made by thoracotomy-lung biopsy in two subjects, autopsy in two, transbronchoscopic biopsy in one and bronchoalveolar lavage (BAL) in one. Some of our cases presented unusual associations that have not been described previously in the medical literature: renal tubular acidosis, Fanconi's disease, glioblastoma multiforme and atrioventricular septal defect. In two patients, treatment with acetylcysteine and ambroxol was unsuccessful. Therapeutic BAL improved the clinical, analytical, functional and radiological aspects of two cases. In one subject, three months after the diagnosis of PAP, pulmonary tuberculosis appeared. Both diseases disappeared with antituberculous treatment.

Value of CT-guided fine needle aspiration in solitary pulmonary nodules with negative fiberoptic bronchoscopy

The usefulness of fine needle aspiration (FNA) with CT-guidance was evaluated in the diagnosis of solitary pulmonary nodules (SPN) following negative fiberoptic bronchoscopy in 84 patients. The records were analyzed for all patients with SPN who had undergone chest FNA in the years 1988 to 1990, showing previous nondiagnostic fiberoptic bronchoscopy. A final diagnosis was made by biopsy (transbronchial, thoracotomy or necropsy), response to therapy or follow-up of the lesions. The patients had medium-sized lesions, 2.87 +/- 1.11 cm, adherent to the pleura in 62%. In the diagnosis of malignancy FNA showed 76% sensitivity, 100% specificity, 100% positive predictive value, 52% negative predictive value and 81% accuracy. These results were correlated with histology in 84% of the cases. One pulmonary hemorrhage, which resolved spontaneously, and 12 cases of pneumothorax, requiring a thoracic tube in 4 patients, were noted.

Breathing pattern and central ventilatory drive in mild and moderate generalised myasthenia gravis

BACKGROUND

Myasthenia gravis is a specific autoimmune disease characterised by weakness and fatigue. Respiratory muscle weakness has been studied using the determination of maximal respiratory pressures, but the response of respiratory centres is not well characterised. This study was undertaken to determine the breathing pattern and the central ventilatory drive in patients with mild and moderate generalised myasthenia gravis.

METHODS

Twenty four patients with myasthenia gravis were studied, divided into two groups. Group 1 included 13 subjects (eight women and five men aged 23-64) with mild generalised myasthenia gravis, and group 2 was composed of 15 patients (11 women and four men aged 23-69) with moderate generalised myasthenia gravis. A control group comprised 15 healthy persons with a similar age and sex distribution. Spirometric measurements and maximal respiratory pressures were performed under basal conditions in all subjects, and the rate and depth of breathing and the inspiratory occlusion pressure in the mouth in the first 0.1 second (P0.1) were measured.

RESULTS

No difference was detected for parameters of breathing pattern between patients in group 1 and control subjects, although P0.1 was higher in those in group 1. Subjects in group 2 had a lower tidal ventilation, shorter inspiratory time, and a higher frequency with a higher P0.1 than control subjects.

CONCLUSIONS

Mild myasthenia gravis causes increased neuromuscular drive with a normal breathing pattern. Moderate myasthenia gravis is characterised by a more rapid shallow breathing pattern.

[3 nonidiopathic forms of bronchiolitis obliterans organizing pneumonia]

Bronchiolitis obliterans organizing pneumonia is the most serious disease of the bronchioli. An idiopathic form of the disease important for differential diagnosis in incipient forms of pulmonary fibrosis has been reported in the literature, along with other forms associated to drug use, infections, and collagen and localized diseases. We describe 3 patients with bronchiolitis obliterans organizing pneumonia, one associated with rheumatoid arthritis and consumption of gold salts, one with HIV infection and one localized form associated with pulmonary hydatidosis.

[CT-guided fine-needle thoracic aspiration puncture. Its cost effectiveness and complications]

OBJECTIVE

To study the profitability and complications of the puncture aspiration with thoracic thin-needle (PATTN).

METHODOLOGY

The results of 160 PATTN, performed under TC control in 131 men and 29 women, average age 61.24 +/- 15.17 years were analyzed. The diagnosis obtained by PATTN was compared with the definitive diagnosis made with biopsy (bronchial, thoracotomy, or mediastinoscopy), the evolution or response to treatment, or at autopsy. Factor related to greater diagnostic reliability and risk of pneumothorax were analyzed.

RESULTS

For the diagnosis of non-tumoral pathology, the technique achieved a sensitivity (S) of 90 percent, specificity (E) of 96.06 percent, and reliability (F) of 91.71 percent, while in malignant processes, S 72.4 percent, E 100 percent and F 88.52 percent, with a histological correlation of 72.72 percent in the first case and 68.80 percent in the second. The localization in superior lobes, radiological pattern of multiple or cavitied nodules, and size > 2 cm were identified as factors which significantly increased reliability. Pneumothorax was produced in 24 cases (15 percent) and was more common in patients diagnosed of COPD, with a lesion < 2.1 cm, and not attached to the pleura.

CONCLUSIONS

The PATTN offers considerable profitability for the diagnosis of thoracic lesions of any localization and nature, at low costs and with few serious complications.

[The predictive parameters in the response to almitrine treatment]

Almitrine bimesylate (AB) improves hypoxemia in an undetermined number of patients with respiratory failure. Our objective was to try to identify the patients likely to benefit from this treatment. We undertook a double blind study of AB (50-100 mg/day) vs placebo in 21 randomly chosen patients diagnosed as having chronic obstructive bronchitis who were receiving oxygen therapy in the home. The study lasted 3 months (T0 to T3). PaO2 rose from 51 +/- 5.3 to 58.5 +/- 10 mmHg (6.8 +/- 0.7 to 7.8 +/- 1.3 Kpa) in the 12 patients taking AB (p < 0.05). The remaining gasometric variables and results of functional respiratory exploration were unchanged. The 7 patients receiving AB who were defined as responding-whose PaO2 rose more than 5 mmHg (0.66 Kpa)-presented T0 values lower than those of the 7 non-responding patients in the same group, with respect to CO2 occlusion pressure, mean inspiratory flow and minute ventilation for both air and CO2. These variables can serve as predictors for gasometric response to AB.

[Elevated negative predictive value of angiotensin converting enzyme in the diagnosis of active sarcoidosis]

OBJECTIVE

To evaluate the usefulness of angiotensin converting enzyme (ACE) in the differential diagnosis of active sarcoidosis in action with other interstitial and granulomatous processes.

METHODS

The study involved 30 patients with a histological diagnosis of sarcoidosis, 38 subjects with anatomopathologically and/or microbiologically confirmed pleuropulmonary tuberculosis, and 12 subjects with idiopathic pulmonary fibrosis confirmed by histological studies. Following the technique developed by Rohatgi and Ryan, a radioenzymatic system was used to determine the activity of serum ACE. In patients with sarcoidosis, levels of ACE were measured in active cases as well as those in remission. Our laboratory reference values for those over 20 years of age are 39.84 +/- 9.19 mumol/min/l.

RESULTS

Levels of ACE were significantly higher (p < 0.001) in active sarcoidosis (67.71 +/- 17.73 mumol/min/l) than during inactivity (41.18 +/- 16.00 mumol/min/l), tuberculosis (46.99 +/- 13.65 mumol/min/l), or fibrosis (35.87 +/- 11.36 mumol/mol/l). A cut-off point of 59 mumol/min/l shows a significant association with the diagnosis of active sarcoidosis (p < 0.001) and reaches a negative predictive value of 90.90%.

CONCLUSION

The usefulness of serum ACE in the differential diagnosis of sarcoidosis should be reconsidered.

[Idiopathic pulmonary fibrosis: new diagnostic and therapeutic perspectives]

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology affecting alveolo-interstitial structures. It is clinically characterized by progressive dyspnea and dry cough. In the physical exploration, crakles at the pulmonary bases and acropachies are usually detected. Its diagnosis has been a major clinical problem. Currently, a definitive diagnosis can be established with high resolution computerized axial tomography, bronchoalveolar lavage and open pulmonary biopsy. The next clinical problem is the assessment of activity, since it allows to differentiate subsidiary patients for receiving treatment. The description of new therapeutical alternatives has brought new perspectives in the management of these patients. Corticotherapy associated to immunosuppressors has allowed to reduce side effects and to obtain dramatic improvements. Lung transplantation, currently under study, will be the therapy of the future.

Lung function and bronchial response to methacholine in young adults who had asthma in childhood

Lung function and bronchial response to methacholine were studied in 47 young adults who had had childhood asthma, and after a period of 14-21 years, showed a different clinical evolution. At present, these subjects have been classified in four clinical groups: asymptomatic, rhinitic, asthmatic only due to exercise, and asthmatic. The same study was performed in 23 healthy individuals without personal histories of respiratory or allergic pathology. We found low spirometric basal values in both the asthmatic group (FEV1 and FEF25-75) and in the group with asthmatic responses to exercise (FEF25-75). No significant differences were found among asymptomatic, rhinitic, and control groups. While airway hyperreactivity was observed in patients who still had asthma, the bronchial response to methacholine in asymptomatic and rhinitic groups was not different from the control group. We conclude that both lung function and bronchial response to methacholine in most of the adults who had asthma in infancy and had been without asthmatic symptoms for many years are similar to those observed in the general population.

[Sarcoidosis and Whipple's disease: an association or a relationship?]

Whipple's disease is a rare, systemic disorder characterized by arthritis, serositis, diarrhea, malabsorption, lymphadenopathies, weight loss, fever, cutaneous hyperpigmentation and central and peripheral nervous system disorders. There are approximately 60 published cases with pulmonary involvement, in general pleuritis, hilar adenopathies and interstitial affectation. In some occasions, sarcoidosis has been diagnosed prior to WD, postulating either a causal association between both entities, or a relationship between them, existing in WD and initial phase which mimics sarcoidosis. We present a patient diagnosed of sarcoidosis who during the evolution of the disease developed gastrointestinal symptoms compatible with WD.

[Evaluation of respiratory muscle function (maximal respiratory pressures) in myasthenia gravis]

In myasthenia gravis (MG) the status of respiratory function has a paramount importance and a careful evaluation is recommended. The weakness of respiratory muscles has been demonstrated in several studies. However, a reliable simple method for the evaluation of this muscular group was lacking until recently, when the usefulness of the maximum respiratory pressures, expiratory (MEP) and inspiratory (MIP), was demonstrated. We evaluated with this method a series of 23 patients with a diagnosis of MG (16 females and 7 males), with a mean age of 46 years (22-68 years), clinically stable and without symptomatic dyspnea. They were distributed in: grade I (5), grade II A (12), and grade II B (6). All of them were evaluated with flow-volume curves, pletysmography, gas transfer, MEP and MIP. The resulting values were then correlated with the expected ones, a reduction greater than one SD being considered as abnormal. The results showed that respiratory function was normal without a restrictive pattern. However, the force of respiratory muscles was reduced in the following proportions of patients in the different groups: grade I: MIP 40%, MEP 60%; in grades II A and II B both MEP and MIP were reduced in 84% of patients. When a statistical comparison with the expected values was carried out it was found that MEP and MIP, considered as a group, were reduced to 53% of the expected values (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)