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Biomedical subjects

A Escolar

Publications and source records attributed to A Escolar.

12 recordsLinked to original sources
PubMed2004

Lung hysteresis: a morphological view.

The lung is an imperfect elastic body and for this reason dissipates energy. The energy applied to the lung in inspiration is not recovered in expiration. The property of dissipating energy receives the name of hysteresis. Lung hysteresis can be quantified because it applies to the area between the ascending and descending portions of the pressure-volume curve. Lung hysteresis comprises parenchymal hysteresis and bronchial hysteresis. Each point on the pressure-volume applies to a different morphology of the lung parenchyma. The changes that take place in the lung architecture during expiration are related to alveolar recruitment: in inspiration the lung volume increases by the opening of distal air units. In expiration the lung volume decreases due to derecruitment. The energy is dissipated mainly in the alveolar recruitment process, in which forces of molecular adhesion, such as surface tension, are at work. Bronchial hysteresis involves the dead space and the bronchial wall being greater in expiration.

Animals↗
PubMed2000

Occupation and risk of malignant pleural mesothelioma: A case-control study in Spain.

BACKGROUND: The association of mesothelioma and asbestos exposure is well known, but some data suggest that probably many people are still being exposed to asbestos without knowing it. METHODS: Between 1993 and 1996, 132 cases (77% males) of histologically confirmed malignant pleural mesothelioma and 257 controls, residents in two provinces of Spain (Barcelona and C¿adiz), were interviewed. They were classified according to their probability and intensity of occupational asbestos exposure by a panel of industrial hygienists, based on a detailed occupational history. RESULTS: Age and sex-adjusted odds ratio (OR) for the highest probability of exposure to asbestos was 13.2 (95% confidence interval 6.4-27.3), and 27.1 (9. 28-79.3) for high intensity. A dose-response trend was observed for both, probability and intensity. Overall, 61% of cases and 42% of controls had ever worked in an occupation with risk of asbestos exposure, with an OR of 2.59 (1.60-4.22). In our population 62% of cases could be attributed to occupational asbestos exposure. CONCLUSIONS: A high risk of pleural mesothelioma due to occupational asbestos exposure is confirmed, but there is still a sizeable proportion for which no evidence of occupational exposure was found. Most of these cases could be due to other sources of asbestos exposure, mainly domestic or environmental.

Adult↗
PubMed2000

Multicentric study on malignant pleural mesothelioma and non-occupational exposure to asbestos.

Insufficient evidence exists on the risk of pleural mesothelioma from non-occupational exposure to asbestos. A population-based case-control study was carried out in six areas from Italy, Spain and Switzerland. Information was collected for 215 new histologically confirmed cases and 448 controls. A panel of industrial hygienists assessed asbestos exposure separately for occupational, domestic and environmental sources. Classification of domestic and environmental exposure was based on a complete residential history, presence and use of asbestos at home, asbestos industrial activities in the surrounding area, and their distance from the dwelling. In 53 cases and 232 controls without evidence of occupational exposure to asbestos, moderate or high probability of domestic exposure was associated with an increased risk adjusted by age and sex: odds ratio (OR) 4.81, 95% confidence interval (CI) 1.8-13.1. This corresponds to three situations: cleaning asbestos-contaminated clothes, handling asbestos material and presence of asbestos material susceptible to damage. The estimated OR for high probability of environmental exposure (living within 2000 m of asbestos mines, asbestos cement plants, asbestos textiles, shipyards, or brakes factories) was 11.5 (95% CI 3.5-38.2). Living between 2000 and 5000 m from asbestos industries or within 500 m of industries using asbestos could also be associated with an increased risk. A dose-response pattern appeared with intensity of both sources of exposure. It is suggested that low-dose exposure to asbestos at home or in the general environment carries a measurable risk of malignant pleural mesothelioma.

Adult↗
PubMed1998

Predictive factors of oxygen desaturation during upper gastrointestinal endoscopy in nonsedated patients.

BACKGROUND: Hypoxemia can occur during upper gastrointestinal endoscopy with or without pharmacologic sedation. We investigated possible predictive factors of severe oxygen desaturation (SaO2 < 90%) in nonsedated patients undergoing endoscopy. METHODS: A total of 481 patients who underwent upper gastrointestinal endoscopy without sedation were monitored with continuous pulse oximetry. Multivariate logistic regression analysis was used to identify factors related to the patient, the examination, and the monitoring data that would predict severe desaturation. RESULTS: Mild desaturation (SaO2 between 90% and 94%) was found in 23.7% of the patients, and severe desaturation (SaO2 < 90%) was found in 6.4%. The variables found to predict severe desaturation were basal SaO2 < 95% (odds ratio 67.7), respiratory disease (odds ratio 30.5), more than one attempt needed for intubation (odds ratio 39.4), emergency procedure (odds ratio 14.9), and American Society of Anesthesiologists score of III or IV (odds ratio 3.9). CONCLUSIONS: The predictive variables analyzed in this study can be used to identify patients who are at increased risk for desaturation. Such patients require very close monitoring (pulse oximetry at a minimum). Endoscopists and assistants should be especially alert to the possibility of respiratory depression in these patients.

Adult↗
PubMed1991

Tobacco smoke inhalation pattern, tobacco type, and bladder cancer in Spain.

The association between tobacco smoking and bladder cancer was investigated in a multicenter case-control study conducted in five provinces of Spain between 1983 and 1986. A matched analysis was carried out in males, based on 430 histologically confirmed cases, 405 hospital controls, and 386 population controls, matched by age and place of residence. An increased risk was found for smokers as compared with nonsmokers (odds ratio (OR) = 3.79, 95% confidence intervals (CI) 2.41-5.97), and this increase was significantly associated with the intensity of smoking. Smokers of filter-tipped cigarettes had a reduced risk as compared with smokers of non-filter-tipped cigarettes (OR = 0.57, 95% CI 0.32-1.02). A diminution of risk was also observed for smokers of low-tar and low-nicotine ("light") cigarettes. Depth of inhalation was strongly associated with illness. No difference was shown in the logistic regression model between smokers of black tobacco and smokers of blond tobacco after controlling for depth of inhalation. Although the number of persons who smoked blond tobacco exclusively was small, the results suggest that it is important to consider inhalation patterns when studying risk variations between smokers of black tobacco and smokers of blond tobacco. The age at which a person started to smoke did not appear to affect risk. An analysis of the decrease in risk associated with years since quitting smoking suggested that different components of cigarette smoke may play a role at different stages of the carcinogenic process.

Female↗
PubMed1991

Diet and bladder cancer in Spain: a multi-centre case-control study.

A multi-centre case-control study on bladder cancer and diet was carried out in 5 regions of Spain. We report results on 432 male cases and 792 matched controls. Usual dietary habits were investigated by means of an interview-based dietary history questionnaire. Bladder-cancer cases were selected from the registers of 12 hospitals located in the study areas. Each case was matched by sex, age and area of residence to 2 controls, one identified in the same hospital and one drawn from population lists. Descriptive analyses indicated that the average dietary pattern was typical of Mediterranean populations: a high P/S ratio, high intake of fish, fruits and vegetables and moderate or low intake of meat and dairy products. Relative risks for specific foods and nutrients were adjusted for tobacco smoking and energy intake. Subjects in the highest quarter of intake of saturated fat had a significantly increased risk of bladder cancer (RR for highest quarter = 2.25; 95% CI = 1.42 to 3.55). Moderate increases in risk for high intake of mono-unsaturated fats and calcium, and a slight decrease for iron were also found, but these disappeared after adjustment for saturated fat. Intake of vitamin E was related to slightly reduced risk (RR for highest quarter = 0.72; 95% CI = 0.48 to 1.09) which was not modified by adjustment for fat. No association was found with intake of retinol or carotene. These results, along with those of previous studies, suggest that saturated fat intake may influence the occurrence of bladder cancer.

Calcium↗
PubMed1991

Urinary infection, renal lithiasis and bladder cancer in Spain.

A case-control study on bladder cancer was carried out in 12 hospitals located in 4 regions of Spain. The study included 497 cases and 530 population controls, matched by sex, age and residence. The present paper reports the results regarding the risk for bladder cancer in relation to history of infections and lithiasis of the urinary tract. Increased risk was found for infections starting 4 years or less before diagnosis (OR = 15.00; 95% CL: 6.07-51.66) but no statistically significant increase in risk was observed for infections starting 5 or more years before (OR = 1.44; 95% CL: 0.86-2.47). Our data suggest that the association of urinary infections with bladder cancer is probably not causal and is more likely to be a consequence of cancer, although a weak causal association cannot be excluded. A small but not statistically significant increase in risk was found to be associated with a history of renal lithiasis.

Adolescent↗
PubMed1989

[Design and implementation of a multicenter case-control study on bladder cancer in Spain].

The aim of a case-control design is to make a measurement of the highest possible accuracy, reducing to a minimum the possible selection, information and confusion biases. The design, methods and procedures of a multicentric study carried out in 14 hospitals from 4 autonomous communities in Spain are discussed. Overall 254 incident cases, 243 prevalent cases, 583 hospital controls and 530 population controls were included. The proportion of nonresponders was somewhat higher in population controls, particularly in large cities. Statistically significant differences between cases and controls were not found for socioeconomic levels, educational level, number of jobs, degree of response, duration of the interview, and errors of transcription and codification of information. Also, significant differences were not found between the population and hospital controls regarding diet habits and cigarette smoking. It is considered that a non-biased measurement of the association can be obtained from cases and hospital controls. The collected information was satisfactory. In spite of the lack of adequate facilities for research in hospitals, the development of multicentric etiologic studies is feasible.

Adenocarcinoma↗
PubMed1989

Geographical patterns of cancer mortality in Spain.

This report discusses the methodology and main findings of the Atlas of Cancer Mortality in Spain with special reference to some major forms of cancer. The mortality for all cancers and specifically lung cancer, for both sexes, is highest in the peripheral regions of Spain. This agrees basically with the level of urbanization and industrialization which has developed during the past several decades. Madrid is the outstanding exception to these relationships. The mortality pattern for stomach cancer is directly opposite to that of lung cancer, the more rural inland provinces having higher mortalities and most Mediterranean provinces showing lower mortalities. For breast cancer areas of higher mortality are some northern and some Mediterranean provinces. A similar pattern is shown by other uterus cancer with areas of higher mortality in the Mediterranean provinces. Considered individually, the province of Cádiz shows the greatest risk of death from cancer, being ranked first for the following cancers: lung, oral cavity and pharynx, esophagus, larynx, and prostate for males and esophagus, other uterus, and bone for females. All these findings definitely produce more questions than answers. Future research on analytical epidemiology of cancer in Spain is strongly recommended.

Cluster Analysis↗
PubMed1989

Occupation and bladder cancer in Spain: a multi-centre case-control study.

A case-control study on bladder cancer was carried out in four regions of Spain. The study included 497 cases (438 males and 59 females), 583 hospital controls and 530 population controls matched by sex, age and residence. The present paper reports the results of the analyses on occupational history. Among men, an increased risk of bladder cancer was found for textile workers (OR = 1.97, 95% CL 1.2-3.3), mechanics and maintenance workers (OR = 1.86, 95% CL 1.2-2.8), workers in the printing industry (OR = 2.06, 95% CL 1.0-4.3) and for managers (OR = 2.03, 95% CL 1.2-3.5). The risk was highest among those first employed in the textile industry before the age of 25 and prior to 1960. Among mechanics the risk was highest for those who started after the age of 25 and later than 1960. The OR for smokers who had also been employed in one of the high risk occupations was 7.82 (95% CL 4.4-14.0) which is compatible with a multiplicative effect of joint exposure to tobacco and occupational hazards.

Aged↗
PubMed1980

[Use of antibiotics in a general hospital (author's transl)].

The utilization of antibiotics at a general hospital has been assessed by retrospectively studying the clinical histories of all patients admitted during the month of April 1978 to the Residencia General de la Ciudad Sanitaria Virgen de la Arrixaca (Murcia, Spain). Medical records were reviewed according to a preestablished protocol. Out of 1.057 patients admitted antibiotics were used in 419 (46%), of whom 189 belonged to the medical services and 302 to the surgical ones. Overall, the surgical services utilized more antibiotics and had less bacteriologic data on their patients. Antibiotics more utilized were ampicillin, which use was generally correct, followed by gentamicin, the G-penicillins, and trimethoprim-sulfamethoxazol. Undesirable side-effects of antibiotic treatment were found in 13 cases (2,6%). Infectious disease of bacterial origin was correctly diagnosed in 40% of the cases, while the diagnosis was doubtful or incorrect in the remaining 60% of cases treated with antibiotics. Appropriate bacteriological data were obtained only in 164 cases (33,4%), with positive results in 75 (49,9%). Independent antibiotics were given in association in 157 cases (31,9%). From this study it can be concluded that the more frequent causes of improper antibiotic utilization were the incorrect clinical diagnosis of bacterial infectious disease, the prophylactic use of antibiotics and the scarcity of bacteriological data. It is therefore suggested that systems of supervision of in-hospital antibiotic prescription be updated and continuous education programs for hospital staff be instituted.

Anti-Bacterial Agents↗