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Biomedical subjects

R Alvarez-Sala

Publications and source records attributed to R Alvarez-Sala.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Free radicals in the bronchoalveolar lavage].

Free radicals are usually reactive species, characterized by the possession of one or more unpaired electrons. This molleculles are involved in the pathogenesis of various respiratory diseases. Free radicals have been evaluated in the bronchoalveolar lavage to understand the importance of its role in lung cancer, adult respiratory distress syndrome, interstitial pulmonary diseases, tobacco induced pulmonary damage, hyperoxia and drug-induced lung toxicity. There are evidences suggesting that these agents play an important role in lung injury. These findings could lead the development of new, and more effective, therapeutic agents in some respiratory diseases.

Animals↗
PubMed1998

[Estimate of bibliometric indicators of the impact of +Archivos de Bronconeumología].

The main bibliographic impact factors of ARCHIVOS DE BRONCONEUMOLOGIA for the past two years are estimated. Citations of ARCHIVOS DE BRONCONEUMOLOGIA in 1996 and 1997 by Medicina Clínica and all citing journals grouped under the heading "Respiratory System" in the Science Citation Index were counted. The year the citation appeared and the year of publication of the article in ARCHIVOS DE BRONCONEUMOLOGIA were recorded. The total number of articles published by ARCHIVOS DE BRONCONEUMOLOGIA between 1994 and 1996 were also counted. Based on these data we calculated our journal's impact factor for each year studied. Relative impact factor was also figured. In 1996 the exposure factor achieved was 1.602, the half-life of articles was 2.00 years, the impact factor was 0.069 and the relative impact factor was 1.371. In 1997 the exposure index was 1.477, the citation half-life was 3.00 years and the impact factor was 0.030. In conclusion, the international impact of ARCHIVOS DE BRONCONEUMOLOGIA is modest, although our relative impact factor is greater than that of some other internal medicine publications or specialized journals listed in Journal Citation Reports.

Bibliometrics↗
PubMed1998

CT in the evaluation of the upper airway in healthy subjects and in patients with obstructive sleep apnea syndrome.

AIM: To study if the caliber of the upper airway, measured by CT, allows us to distinguish patients with obstructive sleep apnea syndrome (OSAS) from healthy people. PATIENTS AND METHODS: Sixteen OSAS patients (with an apnea-hypopnea index > 10) and 39 healthy volunteers were studied. Polysomnography and CT of the upper airways during awake periods were performed in both groups. We used third-generation equipment (Toshiba model TCT 600QT). The area of the nasopharynx, oropharynx, and hypopharynx (in inspiration and expiration), the uvula diameter, and retropharyngeal tissue were evaluated. The simultaneous identification of the variables that differentiate between control and OSAS groups was determined by a multivariate discriminant model. RESULTS: The retropharyngeal tissue in OSAS men was greater than those of the control men (10.3+/-3.6 mm vs 6.4+/-2.7 mm; p < 0.01). The multivariate analysis was performed on the 29 men (14 OSAS and 15 non-OSAS) who had information compiled in the selected parameters. The retropharyngeal tissue, expiratory hypopharynx, and uvular diameter are used to create a discriminant model (Wilks' lambda=0.556; p < 0.01). Two non-OSAS and five OSAS patients were incorrectly classified by this model as members of the other group (total rate of error, 24.14%). Therefore, the point estimates of specificity and sensitivity are 86.67% and 64.29%, respectively, for this model. The Pearson correlation coefficient between body mass index and retropharyngeal tissue is 0.63 (p < 0.001). CONCLUSIONS: CT could play an important role in studying the upper airway in patients with OSAS. The determination of the retropharyngeal tissue by CT could be a useful procedure to evaluate OSAS.

Adult↗
PubMed1998

[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.

Adolescent↗
PubMed1997

[New prospects in cystic fibrosis treatment].

Only a few years ago, cystic fibrosis (CF) was considered the most frequent genetic disease in childhood, although survival has increased considerably in recent years owing to improved treatment. We discuss treatments that are still relevant as well as others that are under investigation now, aiming for better understanding of the disease and the therapies that have improved quality of life for CF patients.

Cystic Fibrosis↗
PubMed1997

[Evolution of the bibliometric indicators of production and consumption of Archivos de Bronchopneumología in the last 20 years].

The aim of this study was to evaluate the evolution of bibliometric indicators for authorship and citation of ARCHIVOS DE BRONCONEUMOLOGIA over the past 20 years. At least 16 articles reporting new research or case reports were analyzed for every other year from 1976 to 1996. The following data were collected for each article: type of document, number of authors and their place of work and specialty, time interval between acceptance and publication, and references (including number, types, language, journal name and year of publication). The number of authors per article (collaboration index) averaged around five and has not varied significantly over the 20 years studied. Pulmonologists predominated among the authors, accounting for about 60% of the total, and most contributions came from a few provinces, mainly Barcelona and Madrid. The interval between reception and publication has gradually increased over the 20 years under review, coming to stand around 9.9 +/- 1.6 months in 1996. Most references (over 80%) cite journals and the proportion of references to books has decreased in recent years (from 12.3% in 1976 to 3.5% in 1996). The journal's index of isolation has increased (from 6.2 to 12.1%), as has the index of self-citation (from 0.4 to 6.2%). Although most cited works are in English (over 80%), the proportion of Spanish-language references increased (from 6.2 to 12.1%). In conclusion, maintenance of the number of collaborating authors, the predominance of journals and English-language sources among references are the main traits that characterize the bibliometric indicators for authorship and citation in ARCHIVOS DE BRONCONEUMOLOGIA.

Authorship↗
PubMed1997

Comparison of helium dilution and plethysmographic lung volumes in pregnant women.

The multibreath helium equilibration method is the technique recommended for routine measurement of static lung volumes in normal subjects. However, pregnancy could be an exception to this general rule, due to airway closure during the second half of gestation. The aim of this study was to compare the measurements of lung volumes by plethysmography and helium dilution during pregnancy. Twenty three healthy women were studied at 12, 24 and 36 weeks of pregnancy, and 4 months postpartum. Total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) were measured by multibreath helium equilibration (TLCHe, FRCHe and RVHe) and by plethysmography (TLCbox, FRCbox and RVbox). Only at 36 weeks were there differences between the two methods. RVbox was significantly larger than RVHe (1.01+/-0.18 vs 0.77+/-0.21 L; p<0.001). FRCbox was larger than FRCHe (1.95+/-0.32 vs 1.60+/-0.32 L; p<0.001) and TLCbox was larger than TLCHe (4.83+/-0.52 vs 4.45+/-0.51 L; p<0.05). The 95% limits of agreement for differences between lung volumes measured by the two techniques (helium dilution - plethysmography) at 36 weeks were: -0.42 to -0.06 L for RV; -0.54 to -0.17 L for FRC; and -0.66 to -0.11 L for TLC. We conclude that using the multibreath helium equilibration method to measure lung volumes in at-term pregnant women results in underestimation of functional residual capacity and total lung capacity.

Adult↗
PubMed1996

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.

Adult↗
PubMed1996

[Histiocytosis X and ankylosing spondylitis. A common pathogenesis?].

Histiocytosis X is considered a group of diseases of unknown origin. Nevertheless, the presence of certain lymphocytes disorders and immunocomplexes has permitted us to think that it is an immunologic disease. The ankylosing spondylitis is also a disease of unknown origin, but like the histiocytosis X, might be of immunologic origin. In both entities, a defect of T-lymphocytes has been demonstrated. We present a patient in whom both diseases are associated, which is not reported before in the medical literature. We think that these disorders may be related by a common immunologic alteration.

Adult↗