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Biomedical subjects

J Villamor

Publications and source records attributed to J Villamor.

At least 19 recordsLinked to original sources
PubMed2006

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.

Adult↗
PubMed2006

Exhaled nitric oxide and airway caliber during exercise-induced bronchoconstriction.

Data on the relationship between exercise-induced bronchoconstriction (EIB) and exhaled nitric oxide (NO) in adult patients with asthma are controversial. It is unclear whether endogenous NO may act as either a protective or stimulatory factor in the airway response to exercise or whether changes in exhaled NO simply reflect acute narrowing of the airway. The aim of this study was to assess the changes in the fraction of exhaled nitric oxide (FE(NO)) before and after exercise challenge in patients with asthma and to analyze the relationship between FE(NO) and airway obstruction. Twenty-five non-smoking, steroid-naïve, atopic, adult patients with mild persistent asthma and 12 non-smoking, nonatopic, healthy subjects (control group) performed an exercise challenge on a cycloergometer, with monitored ventilation. FEV1 and FE(NO) were measured at baseline and 1, 5, 10, 15 and 20 minutes after the exercise challenge. Eleven of the asthmatic patients had exercise-induced bronchoconstriction (EIB group) and the remaining 14 did not (non-EIB group). Baseline FE(NO) was higher in the EIB and non-EIB asthmatic groups than in the control group. In the EIB group, FE(NO) was significantly lower 5, 10 and 15 minutes after exercise, and the changes in FE(NO) correlated with variation in FEV1 10 and 15 min after exercise. A significant correlation between baseline FE(NO) and maximal post-exercise decrease in FEV1 was found in asthmatic patients (EIB group). In conclusion, exhaled nitric oxide levels transiently decrease during exercise-induced bronchoconstriction in adult patients with asthma. Baseline FE(NO) might predict the airway obstruction resulting after exercise.

Adolescent↗
PubMed2004

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.

Aged↗
PubMed2002

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.

Chemoreceptor Cells↗
PubMed2001

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.

Acromegaly↗
PubMed2001

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.

Authorship↗
PubMed2000

An evaluation of tissue polypeptide antigen (TPA) in the two bronchoalveolar lavage fractions of lung cancer patients.

BACKGROUND: It has been proven that cytokeratins (CKs) are useful tumor markers for the follow-up, treatment monitoring and prognosis evaluation of lung cancer and among these, tissue polypeptide antigen (TPA) plays an important role. Nevertheless, only a small number of studies have been reported about their diagnostic capacity. Bronchoalveolar lavage (BAL) can be divided into two fractions: bronchiolar (BF) and alveolar (AF). For the above reasons, our aims were (1) to analyze the diagnostic usefulness of TPA in the BAL of lung cancer patients and (2) to observe if, in lung cancer patients, TPA levels in the two BAL fractions are different. This should mean that the study of tumor markers in the BAL should be carried out in both fractions to increase their diagnostic capacity. METHODS: We studied 289 BALs divided into two phases. In phase I, TPA was analyzed in the BAL of six groups of subjects (healthy persons, chronic bronchitis, asthma, respiratory infections, diffuse interstitial pulmonary diseases and lung cancer). In phase II, TPA was studied in both BAL fractions of a group of patients with lung cancer. RESULTS: We observed that TPA levels were significantly higher in the BAL of patients with bronchogenic neoplasias. In these patients, TPA was increased in the BF of the lavage in relation to the AF. In smoker patients with pulmonary carcinomas, TPA was higher in the AF of the BAL than in the lavage of non-smokers. This did not occur in the BF. We found no relation between the TPA concentrations and cancer histology. CONCLUSIONS: We believe that TPA is a useful tumor marker with diagnostic capacity and this capacity is increased when it is studied in the two BAL fractions. Smoking habit may play a role in the secretion of tumor markers by the tumor cells.

Adult↗
PubMed2000

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.

Adult↗
PubMed1999

[Idiopathic pulmonary hemosiderosis in a patient of advanced age].

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease of unknown etiology characterized by hemoptysis, diffuse pulmonary infiltrates and iron-deficiency anemia. It is typically found in children and young adults. Finding that the concentration of siderophages exceeds 20% in bronchoalveolar lavage indicates a diagnosis of IPH. We report the case of a 72-year-old man with repeated diagnoses of respiratory infection, bronchiectasis and melena. Because such a clinical picture is rare for IPH, the final diagnosis was obtained by open lung biopsy.

Aged↗
PubMed1999

[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.

Adolescent↗
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

Regulation of breathing in hyperthyroidism: relationship to hormonal and metabolic changes.

We sought to examine the breathing pattern, inspiratory drive and chemosensitivity of hyperthyroid patients and to explore the interactions between their thyroid hormones, basal metabolism and chemosensitivity. We studied 15 hyperthyroid patients and 15 sex- and age-matched controls. Thyroid hormone levels, arterial blood gas tensions, lung volumes, diffusing capacity for CO, maximal respiratory pressures and oxygen uptake measurements were performed. Breathing pattern and mouth occlusion pressure (P0.1), as well as ventilatory and P0.1 responses to hyperoxic progressive hypercapnia and isocapnic progressive hypoxia, were also evaluated. Compared with the control subjects, the hyperthyroid patients showed significantly lower resting arterial CO2 tension, tidal volume and significantly higher mean inspiratory flow and P0.1. Ventilatory and P0.1 responses to CO2 and hypoxia were also greater in the hyperthyroid patients than in the control group. All these changes returned to normal after treatment. In the patients, significant relationships between tri-iodothyronine and P0.1, P0.1 response to hypoxia, and P0.1 response to hypercapnia were found. In contrast, in hyperthyroidism there was no relationship between oxygen uptake and P0.1 response to hypoxia. We conclude that hyperthyroid patients exhibit a significant relationship between their thyroid hormone levels and their increased inspiratory drive and chemosensitivity.

Adult↗
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↗