Search PubMed⌕ Search

Biomedical subjects

J Hanacek

Publications and source records attributed to J Hanacek.

8 recordsLinked to original sources
PubMed2006

Effects of thorax irradiation on citric acid-induced cough in guinea pigs.

Thoracic irradiation may cause an acute lymphocytic alveolitis or hypersensitivity pneumonitis. It is well known that cough reflex is sensitized by a number of inflammatory mediators. The purpose of the present study was to investigate the effect of the thoracic irradiation on the cough response in awake guinea pigs. Guinea pigs (Trik strain) were exposed to sham irradiation (n=16), a single irradiation dose of 10 Gy (n=12), and a fractionated irradiation dose (in five fractions) of 15 Gy (n=12) delivered to the thorax. Cough was induced by citric acid aerosol inhalation in gradually increasing concentrations (0.05-1.6 M) during the first week after thoracic irradiation. The cough response was expressed as a total number of coughs induced during all citric acid challenges. Irradiated animals with single dose of 10 Gy exhibited a time- dependent significant increase of citric acid-induced cough in the 6th day after irradiation compared with control animals (P=0.005), whereas cough was not altered significantly in irradiated animals with fractionated dose of 15 Gy. This study demonstrates that the increased cough response may be a determinant of the functional changes of airway nerve-endings mediating cough in the early phase after thoracic irradiation.

Animals↗
PubMed2006

Changes of cough reflex sensitivity induced by cancer radiotherapy of chest and neck regions.

It is reasonable to suppose that airway mucosa can be damaged by irradiation applied to chest and neck regions. The inflammatory process is a consequence of an injury. Airway inflammation is one mechanism responsible for cough induction. So, one can suppose that radiotherapy (RT) focused on the patients' chest or neck may injure airway mucosa, which might change sensitivity of the nerve-endings mediating the cough reflex. The purpose of this study was to examine cough reflex sensitivity (CRS) in patients who underwent RT in the chest and neck regions. CRS test using capsaicin was performed in patients with breast cancer (Group A, n=19), and with lung or neck cancer in (Group B, n=14) who underwent RT. Capsaicin aerosol in doubled concentrations (0.49-1000 microM) was inhaled by a single breath. CRS was defined as the lowest capsaicin concentration that evoked 2 or more coughs (C2). Radiation doses ranged from 40 to 70 Gy. Capsaicin cough challenge was performed before and then in the 2(nd) and 5(th) week of RT. We observed a significantly reduced value of C2, i.e., increased cough reflex sensitivity, in Group B in the 2(nd) week of RT (P= 0.04). We conclude that CRS in the lung or neck cancer patients undergoing RT is significantly enhanced, which could result from injury to the nerve endings in airway mucosa.

Adult↗
PubMed2006

Reliability of the capsaicin cough reflex sensitivity test in healthy children.

Testing cough reflex sensitivity (CRS) in children requires suitable methodology. A CRS test performed under control of inspiratory flow rate (IFR) shows excellent reliability in children, but it is difficult to perform, especially in younger children. The aim of the present study was to find whether the capsaicin CRS test performed without direct control of constant IFR in healthy children is reliable enough for practical use. The CRS test was performed in 27 healthy children, aged 7-17 yr three times within 8 days. Cough was induced by inhalation of capsaicin aerosol in doubling concentrations (0.61-1250 micromol/l) for 400 ms each. CRS was defined as the lowest capsaicin concentration that evoked 2 or more coughs (C2). Although the intraclass correlation coefficient values showed good to excellent reliability of this test, the within-subject standard deviation values revealed lower reliability of this method compared to the CRS test performed under control of IFR. From the results obtained it is reasonable to conclude that the method using uncontrolled IFR in CRS testing provides acceptable precision only when a bigger sample size is used or more tests are performed. Good to excellent reliability of this method was found in children with higher values of C2 and in those aged 13-17 yr.

Adolescent↗
PubMed2004

The influence of hyperoxia on cough reflex intensity in guinea pigs treated with bleomycin.

Inhalation of high concentration of oxygen produces a lung injury in men and experimental animals. In our previous experiment we have found suppression of cough reflex in healthy guinea pigs after an exposure to 100% O2 for 60 hours. This study was designed to find the effect of hyperoxia on cough reflex in guinea pigs with lungs damaged by bleomycin. We used 48 animals (300-400 g) in two separated experiments. 32 of them were intratracheally injected with 1.5 mg bleomycin (Bleocin, Nippon Kayaku Co., Ltd., Tokyo, Japan) for induction of lung damage according to the method described by Parizada et al (20). 16 animals were given saline, only (control). Animals of experimental group were divided into two subgroups according to the lapse of time from bleomycin application. 13 days after bleomycin application animals of the 1st subgroup (16) were exposed to 100% O2 (8) or to room air (8) for 48 h. Similarly, 20 days after bleomycin application guinea pigs of the 2nd subgroup (16) were exposed to 100% O2 (8) or air (8), respectively. Cough was provoked in conscious animals placed in bodyplethysmograph box by inhalation of citric acid aerosol (0.3 mol/L) before, then 13 or 20 days after bleomycin application, and finally at the end of 48-h exposition to 100% O2 (air). The number of coughs was counted from airflow trace recorded by pneumotachograph. Cough was also induced by mechanical stimulation of laryngopharyngeal (LPh) and tracheobronchial (TBr) region in anaesthetized animals (Urethane, 1.1 g/kg, i.p.) just after the end of oxygen exposition and was evaluated from the interpleural pressure record. The results have shown a tendency to inhibition of citric acid cough reflex in animals 13 days treated with bleomycin and exposed to 100% O2, and significant decrease in citric acid induced cough in animals 20 days treated with bleomycin and exposed to 100% O2. Significant changes were present in cough intensity induced by mechanical stimulation of TBr region of the guinea pigs airway treated with bleomycin and exposed to oxygen, too. (Tab. 1, Fig. 3, Ref: 29.)

Animals↗
PubMed2001

Undergraduate medical education in Slovakia--present state and future needs.

There is a lot of problems related to undergraduate medical education (UME) at Slovak medical schools, e.g. low level co-ordination and integration of curriculum, isolation of teaching subjects, amateurish teaching methods, low level of management, which result in low level of effectivity, late and insufficient reactions to the needs of medical practice. There is urgent need for complex reform of UME if we like to be able to complete with high quality medical schools in Europe. The reform should be focused to the content of curriculum--to integrate preventive and acute medicine into the UME, to improve training of medical students for service in primary health care, to start with renaissance of humanistic education of medical students, to improve research training and teaching of medical informatics. For improving organisation of UME it is necessary to prepare modern profile of graduates from medical school, and from the profile to derive co-ordinated and integrated system of UME. The teachers at medical school should be professionals not only in medical specialization, but in pedagogy, psychology and management, too. Passive forms of education (e.g. lectures) should be partly substituted by active methods, e.g. problem--based learning. More attention should be devoted to elaboration of criteria for evaluation quality of teaching process. The reform of UME have to be done if we like to have a chance to be as good as the best medical schools in Europe. I believe, we want it all! (Ref. 31.)

Education, Medical, Undergraduate↗
PubMed1991

Cough reflex in rabbits 24-h and 48-h after sulphur dioxide breathing.

The cough reflex elicitability (CRE), cough reflex strength (CRS) and Hering-Breuer inflation reflex (HBIR) were studied in 51 anaesthetized (Pentobarbital Spofa, 30 mg/kg, i.v.) female rabbits 24-h and 48-h after SO2 breathing. To provoke cough, the interior of the trachea and carina were stroked with a polyethylene catheter. To elicit the HBIR, the lungs were inflated to 1.0 kPa intratracheal pressure. Intrapleural and systemic blood pressures were recorded. The CRE, CRS and HBIR obtained 24-h and 48-h after SO2 breathing were compared with correspondent values of control animals. It was found, that CRE and HBIR were fully recovered 24-h after SO2 breathing, but the CRS was still decreased, however, there were no significant differences in CRE, CRS and HBIR between animals 48-h after SO2 breathing and control animals. It can be concluded, that decrease of the CRS 24-h after SO2 breathing is not due to slowly adapting stretch receptors block of airways.

Administration, Inhalation↗