[Extrinsic allergic alveolitis. Clinical experience at the Instituto National de Enfermedades Respiratorias (INER)]. / Alveolitis alérgica extrínseca. Experiencia clínica del INER.

Extrinsic allergic alveolitis is an interstitial lung disease caused by exposure to a variety of inhaled antigens. In Mexico, the most frequent form is due to the inhalation of avian antigens, markedly pigeon proteins. Depending on type and time exposure, the disease presents different clinical forms usually characterized by progressive dyspnea, ground glass or reticulonodular images on chest x rays, a restrictive functional pattern, rest hypoxemia worsening with exercise, and increase of T lymphocytes in bronchoalveolar lavage with an inversion in the helper/suppressor ratio. In this paper, we discuss a 15-year experience with this pathological problem in Mexico, emphasizing the differences with this disorder in Caucasian populations. Generally, our patients display a chronic form of the disease, which evolves to fibrosis in about one-half of the patients. In this sense, the diagnostic, prognostic, and therapeutic focusing exhibit different elements, and thus the development of clinical and basic research is strongly required.

Diagnostic methods of primary tuberculous pleural effusion in a region with high prevalence of tuberculosis. A study in Mexican population.

STUDY OBJECTIVES: 1) To determine the age distribution of the patients with pleural tuberculosis in a region with high prevalence of tuberculosis; and 2) to evaluate the efficiency of the methods used in its diagnosis. SETTING: The National Institute of Respiratory Diseases in Mexico City, a tertiary reference center for pulmonary diseases. DESIGN: A retrospective study. PATIENTS: 452 consecutive inpatients with diagnosis of pleural effusion from January 1991 to September 1996 were reviewed: 133 patients had a diagnosis of tuberculous pleural effusion of primary origin without parenchymal abnormalities by chest roetgenogram. The others were excluded because of reactivated tuberculosis or non-tuberculous effusion. MEASUREMENTS AND RESULTS: The patients had a mean age of 42 +/- 17 years (98 male, 35 female). Pleural granulomas in the morphological study were found in 87% whereas the baciloscopy and the culture of the fluid were positive in only 8% and 19% respectively. The determination of adenosine deaminase (ADA) gave a diagnostic yield of 84%. CONCLUSIONS: 1) Primary tuberculosis pleural effusion, reported in the English literature, was also present in our adults; 2) the pleural biopsy continued to be the most effective method in the diagnosis of the pathology; and 3) the determination of ADA in an area with high prevalence of the disease was a reliable and unexpensive diagnostic method.

PIP: It is often difficult to diagnose tuberculosis (TB) pleural effusion because the search for Mycobacterium tuberculosis in fluid, or the identification of historical alterations in the pleural biopsy are often false negative. The diagnosis, however, must be timely since 43-65% of patients may develop an active pulmonary TB in the next 3-5 years. To determine the age distribution of patients with pleural TB, the authors reviewed the charts of 452 consecutive inpatients from January 1991 to September 1996 hospitalized at Mexico's National Institute of Respiratory Diseases with a diagnosis of the condition. 133 patients were diagnosed with TB pleural effusion of primary origin without parenchymal abnormalities according to chest roentgenogram. These 98 men and 35 women were of mean age 42 years. Pleural granulomas were identified in 87% of subjects while fluid baciloscopy and culture were positive in only 8% and 19%, respectively. The determination of adenosine deaminase (ADA) produced a diagnostic yield of 84%. Based upon their findings, the authors stress that primary TB pleural effusion may also be seen in adults, closed pleural biopsy remains the most effective diagnostic method, and ADA level is a cheap diagnostic method in countries with a high prevalence of TB.

[Validation of a visual analog scale to measure dyspnea in patients with diffuse interstitial lung disease]. / Validación de una escala análoga visual para medir disnea en pacientes con enfermedad pulmonar intersticial difusa.

In order to validate a form of measuring dyspnea, a visual analog scale (VAS) was applied to 27 patients with different types of interstitial lung diseases (ILD). The test was done in two days with an interval of one month (dyspnea1 and dyspnea2). Additionally, the forced vital capacity (FVC) was obtained on these occasions (FVC1, FVC2). Nineteen patients with a recent diagnosis of ILD (RD) and eight with a previous diagnosis of ILD (PD) were included. In patients with RD, dyspnea1 correlated with FVC1 (r = -0.66, p < 0.01). A month after the initial treatment with steroids, dyspnea (mean +/- SD) decreased from 38 +/- 25 mm to 17 +/- 19 mm (p < 0.03), while the FVC increased from 1086 +/- 464 mL to 1350 +/- 536 mL (p < 0.05). Likewise, dyspnea2 correlated with FVC2 (r = -0.47, p < 0.05). As expected, patients with PD did not exhibit significant changes in the analysis of dyspnea on the second evaluation. The inter-observer coefficient of variation for the 8 patients with PD was of 5% and 9% for the first and second evaluations respectively, while the intraclass correlation coefficient was 0.92 and 0.91 respectively. The intra-observer coefficient of variation of two different observers was of 15% and 16% respectively, while the intraclass correlation coefficient was 0.69 and 0.62 respectively. These results suggest that the use of a VAS might be useful for the initial evaluation and during the follow-up of patients with ILD.

Airflow obstruction and airway lesions in hypersensitivity pneumonitis.

Peripheral airways of lung biopsies from patients with HP commonly show several morphologic changes, including inflammation, fibrosis, or both. In most cases, damage of the airways is parallel to damage of surrounding parenchyma and the functional result is lung restriction, perhaps with alterations in the so-called "small airway tests." Chronic cough and phlegm also are more common in subjects exposed to organic antigens. Overt airflow obstruction is present in a number of patients with HP, and they usually have other risk factors, such as asthma, cigarette smoking, or dust inhalation. There are limited studies of patients who have HP and CAO but not concomitant risk factors for CAO, making it difficult to reach any firm conclusion about their association. In most cases, the lesion that could explain severe airflow obstruction seems to be located in bronchioles but, based on several clinical reports, there is the possibility that HP occasionally ends in emphysema.

Human amniotic fluid modulation of collagenase production in cultured fibroblasts. A model of fetal membrane rupture.

The participation of a mechanical factor as the only cause of rupture of fetal membranes during normal labor or premature rupture has been criticized, and the involvement of an enzymatic mechanism has been proposed. In this study we analyzed the effect of human amniotic fluids at different gestational ages on the collagenase synthesis of cultured fibroblasts. Our results show that term amniotic fluids are capable of inducing the synthesis of collagenase and other proteases in fibroblasts, as revealed by selective increases in collagenase activity and in immunoreactive collagenase. Nonterm amniotic fluids failed to do the same. This phenomenon is proposed as a model for studying the collagen degradation of fetal membranes during term gestation.

[Early respiratory function disorders secondary to tobacco smoking]. / Alteraciones funcionales respiratorias tempranas secundarias al tabaquismo.

The volume of isoflow (VisoV) in 29 asymptomatic smokers with normal radiographic and pulmonary function studies was studied, with the purpose of investigating the presence of early alterations of the transitional airways in a group of 256 chronic smokers. The VisoV was measured using a body test plethysmograph, and two flow-volume curves with air and with helium were performed. 13 out of the 29 subjects (45%) showed an abnormal VisoV of between 17 and 39 per cent (normal 0-10%). This findings suggest that smoking initially damages the small transitional airways and that VisoV is an useful procedure for investigating early damage in this zone.

Tuberculous anergic sera or purified protein derivative treatment induces modification in lymphocyte transformation of cells from patients with tuberculosis.

Peripheral blood mononuclear cells from 20 purified protein derivative (PPD)-reactive (PPD+) tuberculous patients were cultured in autologous, tuberculous anergic, or normal serum. After 12 h of incubation, the serum was eliminated and lymphocyte transformation with PPD was performed. Transformation was inhibited only in cells incubated with anergic serum. In contrast, cells from 11 anergic tuberculous (PPD-) individuals recovered the ability to respond to an optimal PPD dose after treatment with high PPD concentrations followed by several washings. The cells which recovered returned to their initial anergic state when incubated with sera from anergic patients. Under both conditions, incubation with sera did not abolish the response to the mitogen phytohemagglutinin. Cells from healthy PPD+ or PPD- individuals were used as controls. The most important finding derived from serum analysis was the increased levels of specific immunoglobulins G and A in anergic patients.

A latent collagenase in human aqueous humor.

It has been suggested that the trabecular meshwork may be involved in the pathogenesis of open-angle glaucoma, and some authors have pointed out that disorders of the extracellular matrix components may play a role; nevertheless, nothing is known about the normal metabolism of connective tissue molecules in this particular tissue. We recently initiated some studies in this field and have focused on the in vitro effects of aqueous humor on collagen metabolism. We report the finding of a latent collagenase of low molecular weight in aqueous humor obtained from cataractous patients; the enzyme was identified through several methods, including its in vitro activity against radiolabelled type I collagen and additionally with a zymogram technique. It was partially characterized by high-performance liquid chromatography.

Diagnosis and treatment of amebic "empyema": report of eighty-eight cases.

To prevent pleural soilage, early diagnosis and adequate treatment of amebic abscess of the liver are mandatory. Therapy includes administration of amebicidal drugs, drainage of the chest cavity, and treatment of associated respiratory, circulatory, and systemic derangements.