Search PubMed⌕ Search

Biomedical subjects

L Prieto

Publications and source records attributed to L Prieto.

132 records · Page 8Linked to original sources
PubMedDate not supplied

Measurement of response to methacholine inhalation challenge in asthma and allergic rhinitis. PC20 or PC35FEV1?

It has been widely accepted that significant bronchial responsiveness is demonstrated by a 20% fall in the FEV1 during the course of a methacholine challenge (PC20 or PD20FEV1). However, many subjects with allergic rhinitis may have a positive reaction, as evidenced by attaining a PC20 or PD20FEV1, and then demonstrate a plateau. When the PC35FEV1 is used, individuals with this plateau versus individuals with asthma can clearly be differentiated. We thus decided to assess bronchial responsiveness to methacholine with PC20 and PC35FEV1 in asthmatics and patients with allergic rhinitis. Bronchial challenge with methacholine by the method described by Cockcroft et al., with a Hudson 1720 nebulizer (output: 0.198 +/- 0.017 ml/min) was performed on 57 asthmatics and on 56 patients with allergic rhinitis. At the time of the study, they had an FEV1 and FVC greater than or equal to 80% of their predicted normal value and a FEV1FVC% greater than or equal to 70%. Results were expressed as the provocative concentration of methacholine required to produce a 20% and 35% fall in FEV1 (PC20 and PC35FEV1). A plateau was considered if 3 or more consecutive doses of methacholine produced no fall in FEV1 greater than 5%. By the PC20FEV1, bronchial responsiveness was increased (PC20 less than or equal to 18 mg/ml) in 98% of patients with bronchial asthma and in 28% of patients with allergic rhinitis. By the PC35FEV1, bronchial hyperexcitability (PC35FEV1 less than or equal to 40 mg/ml) was detected in 93% of patients with bronchial asthma and in 12% of patients with allergic rhinitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Oral challenge test with sodium metabisulfite in steroid-dependent asthmatic patients.

Oral challenge tests were carried out with sodium metabisulfite solution doses of 0.5, 1, 10, 25, 50 mg and encapsulated doses of 100 and 200 mg, as well as with lactose-placebo, on 44 non-atopic patients with steroid-dependent bronchial asthma, without clinical evidence of intolerance to these agents. Only those patients with an acceptable and not very labile pulmonary function were tested. A single-blind challenge protocol was performed in 22 patients (sodium metabisulfite solutions at pH 2.2 to 2.6) and the positive responses were confirmed by double-blind challenge. The other 22 were tested directly in a double-blind manner (pH4). Initially, 6/44 presented a positive reaction. However, a careful analysis and the confirmation by double-blind challenge of the positive responses obtained with the single-blind test, allowed us to identify 4 false positive responses. Thus, the true prevalence of sulfite sensitivity in our population is 4.5%. A patient with intolerance to sulfite agents also suffered aspirin-induced asthma. The labile tendency of the pulmonary function of the asthmatic patients may have contributed to some false positive reactions and probably explain the very high prevalence found in some studies. It does not appear that the variations of pH decisively influence the result of the challenge test.

Administration, Oral↗
PubMedDate not supplied

Clinical utility of the single point method for theophylline maintenance dose prediction.

In this work, we tried to correlate the usefulness of the Koup nomogram for dosage prediction of continuous theophylline Dm therapy as compared with the usual method of dosification. To do this, a first group of 20 patients (5 with chronic bronchitis and 15 with bronchial asthma) without clinical or biochemical evidence of hepatic or heart disease (3 with smoking habit), were chosen. They were given a loading dose of theophylline 5 mg/kg over 30 min (as aminophylline). A blood sample was then taken after six hours. The result of this value and in accordance with the nomogram determines the individual oral dose of theophylline administered to attain a serum concentration of 10 mg/ml. The oral dose of theophylline, based according to Hendeles was given to another group of 16 asthmatic patients without smoking habit and clinical or biochemical signs of hepatic or heart disease. Two commercial preparations of theophylline were chosen (Theolair or Theodur). We concluded that: 1) Koup's nomogram is useful in estimating the dose requirement of oral theophylline to reach 10 mcg/ml (Css) at steady state, although it could not be useful in greater Css. 2) Among the patients given the dose according to Hendeles, 37.5% showed toxic serum concentrations. 3) Therapeutic serum concentrations could be obtained in the greater number of patients with twice daily doses, independently of the commercial product. 4) A great number of subjects showed the side effects (discomfort of the stomach, irritability, headache) which appeared to have little direct relationship to serum concentration.

Administration, Oral↗
PubMedDate not supplied

[Rhinitis with intolerance to non-steroidal anti-inflammatory agents. Report of 3 cases].

Lumry described 6 patients who presented hypertrophic rhinosinusitis, positive nasal eosinophilia and intolerance to nonsteroidal antiinflammatory drugs, manifested exclusively with naso-ocular symptomatology. We present three patients with clinical manifestations of chronic rhinitis who had noticed before their first visit that several nonsteroidal antiinflammatory drugs precipitated their nasal symptomatology. None of them had ever presented with asthma symptoms. All of them had nasal polyps. The nasal smear showed eosinophilia of 20 to 45%. All three had sinusitis radiologically. The spirometric values were within normal limits (V.C., FEV1, MMEF25-75%). Skin tests with different inhalants antigens using the prick test technique as well as skin tests with pyrazolones (Phenyldimetrylpyrazolone: 25 and 250 mg./ml.; dipyrone: 4 and 44 mg./ml.; amidopyrine: 2.2 and 22 mg./ml.) using the intradermal technique were negative. Serum IgE (Phadezym IgE-Pharmacia) showed values of 23.9, 17.1 and 25.8 IU/ml. respectively. The bronchial inhalation challenge test with methacholine was positive with PD20FVE1 of 14 and 4.8 mg./ml. in two of our patients. Different nonsteroidal antiinflammatory drugs were administered to each patient in different days orally, with intervals of 7 and 25 days (aspirin 500 mg., dipyrone 575 mg., indomethacin 25 mg., naproxen 500 mg.) as well as tartrazine (50 mg.), paracetamol (500 mg.) and lactose as placebo. With 30 minutes intervals and up to three hours after drug administration, the symptoms were observed and spirometry was carried out. Steroids and antihistamines were suspended at least 48 hours before the test. Acetyl-salicylic acid, dipyrone, indomethacin and naproxen produced naso-ocular symptomatology without any objective reduction of FEV1; but paracetamol and tartrazine were well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗