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Biomedical subjects

H Koskela

Publications and source records attributed to H Koskela.

6 recordsLinked to original sources
PubMed1998

Responsiveness to mannitol in asthmatic subjects with exercise- and hyperventilation-induced asthma.

We investigated airway responsiveness to mannitol, a new hyperosmolar challenge, in persons hyperresponsive to airway drying. We studied 36 asthmatic subjects, 18 to 40 yr of age, responsive to exercise (n = 23) and eucapnic hyperventilation (n = 28) defined by a 10% fall in FEV1. Fifteen subjects performed both challenges. All subjects performed a challenge with dry powder mannitol, encapsulated and delivered via a Dinkihaler until a 15% decrease in FEV1 was documented or a cumulative dose of 635 mg was delivered. All subjects responsive to eucapnic hyperventilation and all but one subject responsive to exercise were responsive to mannitol. Sixty-nine percent of subjects had a positive response to mannitol after less than 155 mg (6 capsules) and 94% less than 320 mg (10 capsules). The provoking dose of mannitol required to cause a 15% fall in FEV1 (PD15) was related to the severity of the response to exercise (Pearson's correlation coefficient [rp] = 0.68, p < 0.01) and eucapnic hyperventilation (rp = 0.68, p < 0.01) in subjects who were not taking inhaled corticosteroids. The mean (+/- SD) maximum percent fall in FEV1 after mannitol was 24.4 +/- 6.2% and recovery to bronchodilator occurred within 10 min in most subjects. The mannitol test is simple, inexpensive, faster to perform than hyperpnea with dry air and could become an office-based test. Further studies are now required to determine the sensitivity of mannitol to identify exercise-induced asthma in a random population.

Adolescent↗
PubMed1998

Effect of cold air on exercise capacity in COPD: increase or decrease?

STUDY OBJECTIVE: To clarify the effect of cold air on exercise capacity in COPD. DESIGN: Cycle ergometer tests under different environmental conditions. SETTING: Pulmonary function laboratory and an environmental chamber at a university hospital. PARTICIPANTS: Eighteen patients with stable COPD; 14 completed the study. INTERVENTIONS: A preliminary cycle ergometer test followed by two incremental, symptom-limited cycle ergometer tests, one at 24 degrees C and the other at -20 degrees C. MEASUREMENTS: On the first study day: arterial blood gas analysis, 12 to 15 s maximal voluntary ventilation, maximal expiratory flow-volume curves before and 1 h after inhalation of 80 microg of ipratropium bromide, and diffusion capacity of the lung. During the exercise challenges: spirometric indices, minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), facial skin temperature, and heart rate. The feeling of dyspnea was assessed with a visual analogue scale. RESULTS: The maximal work load was 87.5+/-7.3 W at -20 degrees C compared with 96.4+/-6.9 W at 24 degrees C (p<0.05). Accordingly, the exercise duration was shorter in the cold. Exercise dyspnea was more severe in the cold at equal work loads. The shortening of exercise duration induced by cold air correlated with the enhancement of exercise dyspnea. Furthermore, cold air cooled the facial skin and induced immediate bronchoconstriction. VE, VO2, VCO2, and heart rate did not differ between the warm and cold challenges. CONCLUSIONS: Cold air decreases exercise capacity in COPD, probably by increasing exercise dyspnea.

Adult↗
PubMed1995

Facial cooling, but not nasal breathing of cold air, induces bronchoconstriction: a study in asthmatic and healthy subjects.

Reflex-mediated bronchoconstriction in cold climates may be more important than it has previously been thought. This issue has seldom been studied using physiological methods. We wanted to investigate, using physiological methods, what triggers the bronchoconstriction occurring at cold ambient temperature during resting nasal ventilation: cooling of the skin of the face or cooling of the nasal cavity. Three experiments were carried out in 15 stable asthmatics and 10 healthy volunteers: 1) a whole-body exposure to subfreezing temperature in an environmental chamber, during which the subjects breathed cold air through the nose; 2) a similar exposure to subfreezing temperature except that the subjects now breathed warm air through the mouth from outside the chamber; and 3) nasal breathing of subfreezing air from a heat exchanger whilst the subjects sat at room temperature. Spirometric values and facial skin temperature were measured both during and after the exposures. Maximal decrements (means +/- standard errors) of forced expiratory volume in one second (FEV1) in experiments 1, 2 and 3 were: 5.8 +/- 0.8, 5.1 +/- 0.7 and 2.1 +/- 0.5%, respectively (p < 0.001). Only the two experiments in the environmental chamber induced significant bronchoconstriction. All responses were of similar magnitude in the asthmatic and the healthy subjects. The cooling of the skin of the face seems to be the trigger for the bronchoconstriction during resting nasal ventilation at cold ambient temperature both in asthmatic and nonasthmatic subjects.

Adult↗
PubMed1994

Effect of whole-body exposure to cold and wind on lung function in asthmatic patients.

To assess the effect of subfreezing temperature and wind on lung function in asthmatic patients, an exposure to subfreezing temperature at rest, a moderate exercise challenge at subfreezing temperature, and a similar exercise challenge at room temperature were performed in 19 stable asthmatic subjects in an environmental chamber with an artificial wind. The mean maximal falls in FEV1 were 5.3, 11.7, and 4.8 percent, respectively. The two challenges at subfreezing temperature caused statistically significant changes in FEV1, but the exercise challenge at room temperature had no effect. A large variation in the sensitivity to cold was found. The time courses of the responses varied between the challenges, suggesting at least partially different mechanisms. The results indicate that even moderate exercise can cause severe bronchoconstriction in certain stable asthmatic subjects at climatic conditions similar to the Scandinavian winter. The importance of reflex mechanisms causing bronchoconstriction in physiologic conditions is discussed.

Adult↗
PubMedDate not supplied

Prevalence and risk factors of genital human papillomavirus (HPV) infections in healthy males: a study on Finnish conscripts.

BACKGROUND AND OBJECTIVES: Prevalence of genital human papillomavirus (HPV) infection in the general population is not known. No one test alone can detect all HPV infections. GOAL OF THIS STUDY: To determine the prevalence of and risk factors for genital human papillomavirus (HPV) infections in healthy males. Voluntary Finnish Army conscripts were examined using peniscopy, cytology (PAP smear) and polymerase chain reaction (PCR) in brush cytology samples. STUDY DESIGN: A total of 1,471 (99.6%) males completed the questionnaire soliciting their sexual habits, and 432 of them enrolled in the clinical study. RESULTS: The study group differed from the nonattenders in that they reported more often genitourinary symptoms (P < 0.001), had more casual sexual partners (P = 0.002), and previous STDs (P < 0.001). Classical genital warts were present in 24/432 (5.6%) and papular lesions in 8/432 (1.9%) males. Acetowhite lesions were disclosed in 151/432 (35.0%) cases, of which 61 (14.1%) had peniscopically typical flat HPV lesions. Koilocytes were found in 13/201 (6.5%) PAP smears. HPV DNA was disclosed by PCR in 16.5% (47/285) of the adequate cell smears, and in 7.1% of the males with no peniscopic abnormalities. When considering the men with HPV-positive PCR findings and/or typical peniscopic pattern as HPV-infected (26.2%), many casual partners, previous STDs and no use of condom were significant risk factors for genital HPV infections in the logistic regression analysis. CONCLUSIONS: The reliable assessment of the prevalence of genital HPV infections in healthy males is not only skewed by the selection of the study group by symptoms and promiscuity, but also by the lack of a universally acceptable screening method. The data confirm sexual promiscuity as the most important risk factor for genital HPV infections.

Adult↗