Search PubMed⌕ Search

Biomedical subjects

M Demedts

Publications and source records attributed to M Demedts.

At least 127 records · Page 7Linked to original sources
PubMed1991

Endobronchial tuberculosis mimicking lung cancer in elderly patients.

We report four elderly patients with cough who were referred with the presumptive diagnosis of bronchial carcinoma based on chest X-ray and the macroscopic view on fibreoptic bronchoscopy, but whose final diagnosis was endobronchial tuberculosis. Chest X-ray showed atypical pulmonary infiltrates in three patients, but was normal in one. Bronchoscopic examination revealed ulcerative and/or stenotic lesions. Endobronchial tuberculosis should be considered in differential diagnosis, especially in the elderly.

Aged↗
PubMed1991

Circulating immune complexes in chronic eosinophilic pneumonia.

In 9 out of 14 patients with chronic eosinophilic pneumonia (CEP), followed-up in our department, circulating immune complexes (CIC) and other immunologic indices were investigated. The diagnosis of CEP was based on the typical clinical and radiographic findings and on the demonstration of eosinophilia in serum, bronchoalveolar lavage (BAL), fiberoptic transbronchial biopsies and surgical lung biopsies. CIC measured by solid-phase monoclonal RF binding were always strongly positive during a flare-up of CEP, and CIC measured by solid-phase C1q binding were also positive in most cases. Remissions of CEP were accompanied by lowering or disappearance of CIC. CIC were significantly correlated with eosinophilia (p less than 0.001 for RF and p less than 0.02 for C1q). Other immunologic indices were normal except for increased IgE in two thirds of the patients, and a slightly positive rheumafactor without rheumatic disease in half of the patients. The CIC are thus related to disease activity, and can be used as one of the markers of it, in addition to the classical markers such as eosinophilia and chest X-ray. However, this does not imply that the CIC have a pathogenetic role in CEP; these CIC can, indeed, be an epiphenomenon only.

Adult↗
PubMed1991

Evaluation of the clinical usefulness of capnography curves during a hyperventilation provocation test in the diagnosis of hyperventilation syndrome.

We evaluated the diagnostic usefulness of capnography curves during and following a hyperventilation provocation test (HVPT) in the hyperventilation syndrome (HVS). The diagnosis of HVS was based on the Nijmegen questionnaire and on the reproduction of symptoms during HVPT. Capnography curves of 40 HVS patients, 40 non-HVS patients with psycho-somatic complaints and 26 healthy controls were analyzed. There was no difference in baseline end-tidal CO2-level (FETCO2) between the 3 groups. The spontaneous fall of FETCO2 during the adaptation phase was clearly different in HVS patients versus non-HVS patients or controls: -0.12 mmol/l (95% confidence limits -0.18 to -0.06) versus +0.01 mmol/l (95% confidence limits -0.04 to +0.16) (p = 0.002). The 3 minutes FETCO2 recovery ratio and the 5 minutes ratio were not significantly different between the groups. In conclusion, in this study the spontaneous fall of FETCO2 during the adaptation phase of the HVPT was the only valuable part of the capnography test to discriminate between HVS and non-HVS patients.

Carbon Dioxide↗
PubMed1991

Pitfalls of transthoracic needle aspiration biopsy.

Four cases are presented in whom transthoracic aspiration biopsy with the rotex needle provided a specific diagnosis, which, on thoracotomy was proved incomplete or wrong. Two cases of abscess were in fact excavated squamous cell carcinomas, one case of tuberculosis was in fact accompanied by a scar-adenocarcinoma, and a fourth case of supposed small cell carcinoma was found to be a muco-epidermoid carcinoma. In all cases, the final diagnosis after thoracotomy led to a change in therapy.

Adenocarcinoma↗
PubMed1991

Clinical spectrum of pulmonary tuberculosis in older patients: comparison with younger patients.

We compared the clinical-radiographic presentations of bacteriologically proven tuberculosis in 72 elderly (mean age: 71 yr) and 73 younger patients (mean age: 39 yrs). The tuberculin test (2 TU PPD) was positive in 55% and 92%, respectively. The prevalence of cough, dyspnea, anorexia, and weight loss was higher in the elderly (p less than .05), and night sweats were more prevalent in the younger patients (p less than .01). The radiographic pattern was not different between both groups (p greater than .10): "usual" apicoposterior lesions (with or without other abnormalities) were found in more than 70% of both groups; isolated "unusual" lesions consisted in both groups mainly of anterobasal infiltrations and sometimes of pleural effusions, rounded nodules, or miliary patterns. Yet, initially a wrong diagnosis was made more often in the elderly (p = .05). Malignancy, chronic pulmonary disease, and immunosuppression were more frequently encountered in the elderly (p less than .05), whereas alcoholism and smoking were more frequent in the younger patients (p less than .001). Tuberculosis-related mortality occurred in 6 elderly and 1 younger patient.

Adolescent↗
PubMed1991

Total respiratory resistance and reactance in patients with asthma, chronic bronchitis, and emphysema.

A comparison was made of total respiratory resistance (Rrs) and reactance (Xrs) determined between 6 and 26 Hz by means of a forced oscillation technique in 27 patients with asthma (group A), 28 patients with chronic bronchitis (group B), and 20 patients with emphysema (group E) to examine whether the method can provide data capable of distinguishing among these diseases. The three groups demonstrated a similar reduction in the FEV1. In addition, static and dynamic lung volumes, maximal expiratory flows, diffusing capacity for CO, airway resistance (Raw), and elastic lung recoil were measured. The observed alterations of Rrs and Xrs consisted of an increase in Rrs, a decrease in Rrs with frequency, and a decrease in Xrs. However, significant differences were found between the three groups: Rrs at 6 Hz and average Rrs were most increased in group A, whereas the negative frequency dependence of Rrs and the decrease in Xrs were least pronounced in group E. In all groups Rrs at 6 Hz, the average slope of Rrs, and the average level of Xrs were tightly interrelated and showed in addition a high correlation with airway resistance; the correlations with FEV1 were less satisfactory. Discriminant analysis performed on the complete set of data, excluding diffusing capacity and elastic lung recoil, which were used as selection criteria, demonstrated that forced oscillation parameters were the most important factors discriminating among the groups.

Adult↗
PubMed1991

Indices of oxidative stress in hamster lung following exposure to cobalt(II) ions: in vivo and in vitro studies.

Cobalt, a metal with numerous industrial applications, has been associated with lung disease, an extreme form of which is an interstitial fibrosis. The biochemical mechanisms underlying this toxicity are not understood. In vitro studies have suggested that cobalt(II) ions are able to generate reactive oxidant species (possibly hydroxyl radical) in a reaction with hydrogen peroxide, and we have hypothesized that the occurrence of such an event in lung tissue, and the subsequent development of oxidative damage, may contribute to this pulmonary toxicity. The intratracheal instillation of CoCl2 into hamster lungs resulted after 3 h in decreased levels of reduced glutathione and increases in levels of oxidized glutathione and in the activity of the pentose phosphate pathway. These changes, which are compatible with the generation of oxidative stress, were reversed by 48 h at low Co2+ doses (1.0 to 1,000 micrograms/kg). Irreversible changes at higher doses coincided with the onset of pulmonary edema. Incubation of lung slices with CoCl2 (0.1 to 10 mM) resulted in time- and Co2+ concentration-dependent increases in levels of oxidized glutathione and protein-mixed disulfides and a decrease in reduced glutathione. A concentration-dependent stimulation of the pentose phosphate pathway was also observed. These changes preceded the detection of overt cell toxicity, as assessed by various biochemical parameters. These data indicate that thiol oxidation constitutes an early event in the pulmonary toxicity of cobalt(II) ions and are compatible with the hypothesis that the generation of oxidative stress may be of significance to the toxic process.

Animals↗
PubMed1991

Total respiratory resistance and reactance in ankylosing spondylitis and kyphoscoliosis.

Ankylosing spondylitis and kyphoscoliosis both alter the function of the lung by modifying the mechanical properties of the thoracic cage. The purpose of the present study was to assess the changes in total respiratory resistance (Rrs) and reactance (Xrs) in these patients and to compare these data with conventional pulmonary function tests. In 16 patients with ankylosing spondylitis and seven with kyphoscoliosis we measured lung volumes, maximal flows, diffusing capacity, airway resistance, lung compliance and Rrs and Xrs between 2-26 Hz by means of the forced oscillation technique (FOT). In the patients with ankylosing spondylitis mean total lung capacity was 83% predicted (range 60-105%). Mean values of Rrs were normal; there was a small decrease in Xrs at the lowest frequency. In the patients with kyphoscoliosis mean total lung capacity (TLC) was 41% predicted for arm span (range 26-75%). Mean Rrs was elevated with a negative frequency dependence, and mean Xrs was decreased. The observed differences in Rrs and Xrs between the two groups of patients are related to differences in severity of the restriction. There is evidence that the changes in Rrs and Xrs in both groups are mainly attributable to an increase in chest wall resistance and a decrease in chest wall compliance, while in the patients with kyphoscoliosis an increase in airway resistance and a decrease in lung compliance also intervenes.

Aged↗
PubMed1991

Diagnostic tests of hyperventilation syndrome.

In 90 patients referred to the pulmonary function laboratory for evaluation of hyperventilation syndrome (HVS) and in whom somatic causes of the complaints had been excluded, we investigated the degree of concordance between three widely applied diagnostic methods: 1) the standardized Nijmegen questionnaire on major daily complaints; 2) the reproduction of the same symptoms during the hyperventilation provocation test (HVPT); and 3) the responses of end-tidal CO2 fraction (FETCO2) during the HVPT. In 86% of the patients a concordance was found between Nijmegen questionnaire (i.e. score of 24/64 or more) and symptom reproduction during HVPT (i.e. recognition of at least 2 major daily complaints). Based on these combined data we made a definite diagnosis of HVS in 37 patients, of non-HVS in 40 patients, and we retained only a possible HVS in 13 patients. Each of the 16 complaints in the questionnaire contributed significantly to the distinction between HVS and non-HVS patients, and a striking similarity in rank order of daily complaints and reproduced symptoms was found. The responses in FETCO, during HVPT had little additional diagnostic value. A spontaneous fall of at least 0.25% FETCO2 during the 5 min adaptation period before the HVPT, was most reliably correlated with the aforementioned diagnostic criteria of HVS: specificity 83%, sensitivity 57%, and accuracy 70%. Neither the 3 min FETCO2 ratio nor the 5 min FETCO2 ratio during recovery after the HVPT showed a good correlation with the other diagnostic criteria. The response of FETCO2 during HVPT did especially not provide additional useful diagnostic information in the 13 patients with only possible HVS.

Activities of Daily Living↗
PubMed1991

Isolated intrathoracic tuberculous lymphadenopathy.

We report an 82 yr old man with isolated intrathoracic lymphadenopathy of tuberculous origin, which is an extremely uncommon presentation of tuberculosis especially in elderly Caucasian patients. The diagnosis was suggested by the computerized tomographic (CT)-scan showing central hypodense areas after contrast, and was subsequently proved by mediastinoscopic biopsy with histological and microbiological analysis. The atypical presentation of tuberculosis together with a negative two-step 5 international units of purified protein derivative (IU-PPD) tuberculin skin test and a frequent contact with a cavernous index case points towards a primary infection in this patient.

Aged↗
PubMed1990

Clinical spectrum of endobronchial tuberculosis in elderly patients.

We describe 11 elderly patients with bacteriologically proved endobronchial tuberculosis, representing 15% of our 73 geriatric patients with pulmonary tuberculosis in the period 1980 to 1987. In seven (64%) of the 11 patients, an incorrect diagnosis was initially made. Cough, mostly nonproductive, was invariably present, and general symptoms (fever, anorexia, weight loss) predominated over specific pulmonary symptoms. The radiographic features were rather "unusual": in only two (18%) of the 11 cases, apicoposterior consolidations with or without cavitation were found. Fiberoptic bronchoscopy showed a range of endobronchial abnormalities that included ulcerations, mass lesions, and fibrostenoses. Antituberculous treatment generally led to satisfactory results. Still, residual bronchostenosis was observed in four (57%) of seven patients in whom a control bronchoscopy was done. In one of these four patients, a pneumonectomy had to be performed for uncontrollable retro-obstructive infections, and in another, repeated endoscopic dilatations were effective. In elderly patients, endobronchial tuberculosis should be considered in the differential diagnosis, especially in the presence of chronic cough. In these patients, the chest roentgenogram may be clear or suggestive of bronchial carcinoma or pneumonitis.

Aged↗
PubMed1990

Effects of acetazolamide on medullary extracellular pH and PCO2 and on ventilation in peripherally chemodenervated cats.

The responses of ventilation and of medullary extracellular fluid (ECF) pH and PCO2, to an intravenous (i.v.) infusion of 50 mg/kg acetazolamide (an inhibitor of carbonic anhydrase), were measured in cats anaesthetized with chloralose and urethane, in which both bilateral vagotomy and carotid nerve section had been performed. After 2 h, it was observed that: acetazolamide caused an acidosis in medullary ECF which was still developing after 2 h, reflected by a progressive fall in pH (mean = 0.215 pH units in 2 h), while ECF PCO2 showed an insignificant rise of about 1 kPa; acetazolamide caused a considerable rise in ventilation, which largely developed in the first 15 min after drug infusion; the direction of the ECF acid-base responses in the first 15 min varied, whereas that of the ventilatory response did not. Furthermore, the time course of the former developed quite differently from the latter. It was therefore concluded that the observed changes in medullary ECF pH and PCO2 can not explain the large and fast ventilatory response of acetazolamide.

Acetazolamide↗