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Biomedical subjects

H T Folgering

Publications and source records attributed to H T Folgering.

At least 91 records · Page 5Linked to original sources
PubMed1990

The intercostal-to-phrenic inhibitory reflex in the human fetus near term.

Human fetal breathing movements (FBM) differ from neonatal breathing in that they are predominantly paradoxical and are not present all the time. Respiratory pauses are common in the fetus while prolonged apneas are life-threatening in the neonate. In the latter they occur during state 2 (active sleep) when paradoxical breathing is more frequent. Then the inward movement of the thoracic wall causes spreading of the caudal ribs which may elicit an intercostal-to-phrenic inhibitory reflex (IPIR) leading to apnea. This is not the case in state 1 (quiet sleep). In the fetus similar sleep states, state 2F and 1F respectively, have been identified and we investigated if the IPIR is already present before birth and if so, if the response is different between 1F and 2F. In 21 healthy fetuses between 37 and 40 weeks, two real time scanners and a cardiotocograph were used to asses the fetal behavioural state. If FBM were present, the caudo-lateral part of the fetal thoracic wall was shortly compressed manually and the period that FBM ceased measured. During the same epoch moments of sham-stimulation, i.e. control periods without actual compression were also carried out. In 15 out of 16 fetuses with FBM in 1F, and in 19 out of 19 fetuses in 2F, compressions were immediately followed by an apnea. In contrast, moments of sham-stimulation never induced apnea, indicating that the IPIR is indeed present in both behavioural states.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryonic and Fetal Development↗
PubMed1990

Psychological changes during pulmonary rehabilitation and target-flow inspiratory muscle training in COPD patients with a ventilatory limitation during exercise.

The effects of pulmonary rehabilitation (PR), target-flow inspiratory muscle training (IMT) and a combination of both treatments (PR + IMT) on psychological parameters and the physical performance were studied in a group of sixty chronic obstructive pulmonary disease (COPD) patients with a ventilatory limitation during exercise (mean age +/- 59, mean FEV1 +/- 50% of predicted). After the ten week training period scores of anxiety and depression were decreased in the PR and the PR + IMT group, but not in the IMT group. In the PR group these scores were still decreased after a one year follow up period. Maximal workload and the activities in daily life (ADL) scores were improved significantly after the training period in the PR and the PR + IMT group. Most of these improvements had disappeared after one year. The 12 min walking distance was increased in all patient groups after the training period and was still increased after the follow up period. The exercise capacity was correlated significantly to lung function parameters. The psychological well-being, however, was not correlated with lung function parameters, but was closely related to ADL scores. The improvement of the psychological parameters was not correlated to the improvement of the exercise capacity after the training period or after one year. The results indicate that the psychological well-being and the physical condition are improved by different mechanisms during a pulmonary rehabilitation programme.

Adaptation, Psychological↗
PubMed1990

Metabolic response to enteral food in different phases of cancer cachexia in rats.

The resting energy expenditure (REE) and postprandial energy expenditure (PPEE) were measured using closed-circuit indirect calorimetry in Walker 256 carcinosarcoma-bearing rats. The results were compared to the appropriate controls. The PPEE measurements were performed after oral test feeding. At the beginning of the tumor growth, the REE and PPEE were similar in all groups. In the second week, the tumor-bearing rats showed increased REE and decreased PPEE. The tumor-bearing rats lost weight and became anorectic. After day 14, the REE rapidly dropped to very low values and the body weight continued to decrease. This study makes it possible to differentiate three phases of cancer cachexia: silent or preclinical, hypermetabolic and hypometabolic.

Animals↗
PubMed1990

Variations of respiratory impedance with lung volume in bronchial hyperreactivity.

The total respiratory impedance was measured at various frequencies (4 to 52 Hz) with a pseudo-random-noise forced oscillation technique (FOT). The apparatus (Oscillaire) was connected with a spirometer forming a closed respiratory circuit in which gas concentrations were kept constant. Measurements were made in 15 healthy subjects (group 1) and in 30 asthmatic patients with bronchial hyperreactivity, subdivided into group 2 treated only with inhaled beta 2-mimetics (n = 15) and in group 3 using both beta 2-mimetics and steroids in inhalation (n = 15). No significant differences were found between the impedance data obtained with the Oscillaire alone and those obtained with the Oscillaire connected with the spirometer circuit. The impedance was measured at FRC level, and at FRC +1 L and -1 L. The relative changes of the resistance at 8 Hz were -23.2 percent (13.8) at FRC +1 L and +40.9 percent (29.3) at FRC -1 L relative to the values at resting FRC. This inverse relation between airway resistance and lung volume was similar in all groups. The average reactance decreased at FRC -1 L in all groups. However, at FRC +1 L the average reactance increased 50.6 percent in group 2 and 94.2 percent in group 3, but decreased in group 1. Concomitant changes were observed in the resonant frequency and in the frequency dependence of resistance. Because of these qualitatively different responses of the impedance data to changes in lung volume (both for the whole group and for each individual) between healthy subjects and asthmatic patients, this test might be useful for the diagnosis of bronchial hyperreactivity.

Adult↗
PubMed1989

Reproducibility of incremental maximal cycle ergometer tests in patients with mild to moderate obstructive lung diseases.

This study was designed to examine the reproducibility and the learning effects of incremental maximal cycle ergometer testing in patients with obstructive lung diseases who are untrained and have never done such a test before. Eleven patients were studied on 2 consecutive days with an interval of 24 h. The reproducibility (expressed in relative duplicate error) of most of the parameters tested was good: workload (watt) 4.5%, maximal oxygen consumption (VO2max 3.5%, gas exchange ratio (R) 3.4%, and heart rate 3.7%. Moderate reproducibility was found in maximal ventilation (VEmax) 6.6%, carbon dioxide production (VCO2max 6.0%, and respiration frequency (RF) 8.3%. The reproducibility of the time between the start of the test and the minimum value of VE/VO2 and VE/VCO2 was low. We concluded that in these patients the results of incremental cycle ergometer testing showed good reproducibility in a test-retest procedure. There were no learning effects.

Adult↗
PubMed1989

Effects of inhaled budesonide on the relationships between symptoms, lung function indices and airway hyperresponsiveness in patients with allergic asthma.

Fourteen patients with allergic asthma and exercise-induced bronchoconstriction (EIB) completed this study. Effects of a 6-week treatment with inhaled budesonide, daily dose 4 x 0.1 mg, were compared to the effects of treatment with placebo on patient symptom score, clinical assessment score, additional beta 2-agonist use, lung function indices, PC20 histamine and degree of EIB. Furthermore, relationships between these parameters during treatment with placebo and budesonide were analysed. Treatment with budesonide significantly improved symptom scores, FEV1 and morning peak expiratory flow rate (PEFR). A clear decrease in additional beta 2-agonist use was observed. PC20 histamine increased significantly, whereas EIB decreased significantly. Patient symptom scores and clinical assessment scores showed a significant correlation before and after treatment. No relationship was observed between these scores and other parameters, except for nocturnal dyspnoea/wheeze correlating significantly with beta 2-agonist use before treatment with budesonide. There was a significant correlation between beta 2-agonist use before treatment with budesonide and FEV1, morning PEFR, diurnal variation in PEFR, PC20 histamine and EIB. During treatment with budesonide only a significant correlation of beta 2-agonist use with PC20 histamine remained. FEV1 before treatment correlated with PEFR, diurnal variation in PEFR and EIB significantly. During treatment with budesonide the relationship of FEV1 with EIB was no longer observed. Diurnal variation in PEFR correlated with EIB significantly only before treatment. It is concluded that symptom scores are of little value in contrast to the measurement of beta 2-agonist use, lung function indices and airway hyperresponsiveness in the assessment of asthma patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1989

Effects of long-term treatment with inhaled cromoglycate and budesonide on bronchial hyperresponsiveness in patients with allergic asthma.

Twenty two allergic patients with bronchial asthma completed this study. Effects of long-term treatment with inhaled cromoglycate 4 x 2 mg.day-1 were compared to the effects of inhaled budesonide 4 x 0.1 mg.day-1 on symptoms, additional beta 2-agonist use, lung function and bronchial hyperresponsiveness measured by the provocation concentration of histamine producing a 20% fall in forced expiratory volume in one second (FEV1) (PC20 histamine) and exercise-induced fall in FEV1. The study was carried out in a double-blind way with a randomized crossover design using a double-dummy technique. After a single-blind placebo period, the two active treatment periods of 6 weeks were separated by a single-blind placebo period. Symptom score and beta 2-agonist use decreased during both active treatment periods, which showed no mutual differences. Morning and evening peak expiratory flow rates were significantly higher during treatment with budesonide versus placebo (p less than 0.01 and p less than 0.001), and also versus cromoglycate (p less than 0.02 and p less than 0.05). FEV1 showed improvement after a 6 week treatment with budesonide versus placebo (p less than 0.05), although there was no significant difference between the two active treatments. PC20 histamine did not change during treatment with cromoglycate. Budesonide showed a significant increase in PC20 histamine versus placebo (p less than 0.05) and was marginally significantly better than cromoglycate (p = 0.05). Exercise-induced fall in FEV1 was not changed by cromoglycate, but improved significantly during budesonide in comparison with placebo (p less than 0.01) and also with cromoglycate (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1989

Sauna to transiently improve pulmonary function in patients with obstructive lung disease.

The influence of sauna on pulmonary functioning in patients with an obstructive pulmonary disease was studied in 12 male patients by measuring forced vital capacity (FVC) and forced expiratory volume in one second on seven measure points the day of the sauna program. Despite the fact that body cooling and changes in osmolality of bronchial liquid can induce bronchoconstriction, we measured a significant improvement of the lung function parameters: FVC values were 3.22 +/- 0.89 and 3.6 +/- 0.99 before and after the sauna program, respectively. It is concluded that patients with an obstructive pulmonary disease can take part in sauna programs without eliciting bronchoconstriction; sauna even causes transient improvement of the lung function.

Adult↗
PubMed1988

Effects of inhaled beclomethasone dipropionate on beta 2-receptor function in the airways and adrenal responsiveness in bronchial asthma.

Sixteen patients suffering from bronchial asthma, with or without chronic bronchitis, sufficiently severe to be treated with inhaled corticosteroids, were studied in a single-blind trial (blind observer) of beclomethasone dipropionate (BDP) given in three randomized dosage regimens: 500, 1000 and 2000 micrograms per day, each for 4 weeks. The beta 2-adrenergic agonist response curve showed a dose-dependent increase in FEV1 which was not affected by different doses of BDP. A small but significant reduction in basal cortisol levels was observed after BDP 500 micrograms/day. There was no significant difference between the various doses of BDP in reducing cortisol level and stimulation with tetracosactide remained unchanged. The study showed a gradual, dose-dependent improvement in lung function, statistically significant for morning peak expiratory flow rate at BDP 2000 micrograms/day. Dyspnoea score and beta 2-agonist use decreased, reflecting the anti-asthmatic effects. An increase in total leukocyte count was observed, together with a decrease in the eosinophil count. Oral candidiasis was seen in 2 out of 16 patients. It is concluded that the clinical anti-asthmatic effects of corticosteroid treatment by inhalation are not due to modulation of beta 2-receptor function in the airways.

Adrenal Glands↗
PubMed1988

The velocity step test. Its use in the evaluation of the effects of drugs in dizzy patients.

The effect of flunarizine (10 mg/day) was studied in open and double-blind clinical trials. Patients presenting the symptom of dizziness were diagnosed as having the hyperventilation syndrome. They showed vestibular hyperreactivity in the velocity step test. This test was performed before and after 4-6 weeks of treatment. The results of treatment were compared with a control or placebo group. In an open trial, 12 of 14 patients reported alleviation of dizziness during treatment and showed a significant decrease in right-left asymmetry of their velocity step responses. In a double-blind trial, no significant difference in effects or side effects was found between the drug and placebo groups.

Adolescent↗
PubMed1988

Effects of terbutaline and atenolol on large and small airways in asthmatic patients.

In order to localize the main site of action of the beta 2-adrenoceptor selective agonist terbutaline and the beta 1-adrenoceptor selective antagonist atenolol in the airways of asthmatic patients, we compared the effects of these drugs on maximal expiratory flow-volume (MEFV) curves when breathing air and when breathing a helium-oxygen (HeO2) mixture. To investigate whether a shift in localization of the bronchodilator effect occurs when terbutaline is inhaled repeatedly, dose-response curves with terbutaline were performed for parameters derived from MEFV curves when breathing air and for density dependence of expiratory airflow. By measurement of MEFV curves when the patients were breathing air alone, it was not possible to determine whether there is a difference in the bronchoconstrictor effect of atenolol between large and small airways. Inhalation of terbutaline to a cumulative dose of 2.0 mg induced a stepwise improvement in expiratory airflow parameters for large and small airways function when breathing air. Doubling the dose of inhaled terbutaline to 4 mg did not result in any further improvement of lung function. Neither atenolol nor terbutaline induced significant mean changes in density dependence of expiratory airflow. This was partly due to large inter- and intra-individual variations of this parameter. Another possibility is that atenolol and terbutaline effect large and small airways function equally.

Administration, Inhalation↗
PubMed1988

Extrinsic allergic alveolitis caused by spores of the oyster mushroom Pleurotus ostreatus.

Four mushroom workers have developed an extrinsic allergic alveolitis, after working with the oyster mushroom (Pleurotus ostreatus). After provocation with aerosolized spores under laboratory conditions, the four patients showed the complaints of an extrinsic allergic alveolitis; a rise of body temperature, leucocytosis and changes of lung function parameters were observed. Antibodies against the spores were assessed in the blood of these patients.

Adolescent↗
PubMed1986

Respiratory tolerance of bisoprolol and metoprolol in asthmatic patients.

The respiratory tolerance of the beta 1-adrenoceptor-selective blockers bisoprolol and metoprolol was investigated in eight male asthmatic patients. The interaction with the bronchodilatory effect of the beta 2-adrenoceptor-selective agonist terbutaline was studied to compare the beta 1-adrenoceptor selectivity of 10 and 20 mg bisoprolol and 100 mg metoprolol. The three beta-blocker doses caused a significant decrease in heart rate at rest. Systolic and diastolic blood pressure decreased significantly after administration of 20 mg bisoprolol and 100 mg metoprolol, but not after administration of 10 mg bisoprolol. Both beta-blockers caused an increase in bronchoconstriction, as measured by a significant fall in peak expiratory flow rate (PEFR). Only 10 mg bisoprolol caused a significant decrease in vital capacity (VC) and forced expiratory volume in 1 s (FEV1). Bronchoconstriction was rapidly reversed by inhalation of terbutaline in all patients. There were no differences between the responses of FEV1, VC, and PEFR to terbutaline with any of the beta-blockers, indicating a good degree of beta 1-adrenoceptor selectivity of 10 and 20 mg bisoprolol and 100 mg metoprolol in humans.

Adrenergic beta-Antagonists↗
PubMed1986

A comparative study on the ventilatory and haemodynamic effects of xamoterol and atenolol in asthmatic patients.

The effects of single oral doses of atenolol 50 mg and xamoterol 200 mg (a recently developed partial beta 1-adrenoceptor agonist) on lung function, heart rate and blood pressure were investigated in 11 patients with asthma. Xamoterol caused a significant increase in heart rate and systolic blood pressure, which changes are consistent with the partial beta 1-adrenoceptor agonist activity of this drug. Atenolol induced a significant decrease in FEV1 and the forced vital capacity (FVC); there was a non-significant change in FEV1 and FVC after xamoterol. There was no significant difference between the effects of atenolol and xamoterol of FEV1 and FVC. Bronchospasm induced by atenolol 50 mg and xamoterol 200 mg was completely reversed by inhalation of the beta 2-adrenoceptor agonist terbutaline to a cumulative dose of 4.0 mg.

Adrenergic beta-Agonists↗
PubMed1986

Vestibular hyperreactivity and hyperventilation.

In a group of 26 patients with a hyperventilation syndrome, 77% showed vestibular hyperreactivity of velocity step responses, mostly due to an increase in gain of the vestibulo-ocular reflex (VOR), apparent from an increase in initial velocity, but also due to an increase in the time constant. Similar effects were found among 11 normal subjects after forced hyperventilation. In another group of 44 patients whose primary complaint was dizziness and who showed vestibular hyperreactivity without having any other demonstrable abnormality, a hyperventilation syndrome was found in 75%. This suggests that the velocity step test without hyperventilation provocation is a useful test for the detection of a hyperventilation syndrome.

Adolescent↗
PubMed1986

[Sleep apnea syndrome, snoring and uvulopalatopharyngoplasty].

Sleep-related closure of the upper airways is the key feature of the obstructive sleep apnoea syndrome (OSAS). Excessive daytime sleepiness and loud snoring are the major signs. It is not possible to differentiate patients with the single complaint of habitual snoring from patients with sleep apnoea by their history alone; polysomnography is a mandatory procedure. Recently, uvulopalatopharyngoplasty (UPPP) has been introduced as a surgical procedure to treat OSAS and excessive snoring. This paper presents the results of UPPP in eleven patients evaluated by means of postoperative polysomnography.

Adult↗