Search PubMed⌕ Search

Biomedical subjects

H Worth

Publications and source records attributed to H Worth.

At least 73 records · Page 4Linked to original sources
PubMed1994

Myocardial infarction in an adult resulting from coronary aneurysms previously documented in childhood after an acute episode of Kawasaki's disease.

Coronary aneurysms resulting from a previous episode of Kawasaki's disease are considered an important cause of myocardial infarction in children. A case of a 19-year-old man presenting with an acute myocardial infarction associated with coronary aneurysms is described. These coronary lesions were previously evaluated angiographically and echocardiographically at the age of 13 years, 5 months after the acute episode of a Kawasaki's disease.

Adolescent↗
PubMed1994

Therapy of steroid-induced bone loss in adult asthmatics with calcium, vitamin D, and a diphosphonate.

In a prospective, controlled, and randomized clinical trial, we examined the effects of treatment with vitamin D (1,000 IU/d), calcium (1 g/d), and ethane-1-hydroxy-1,1-diphosphonate (EHDP; 7.5 mg/kg body weight) on vertebral bone mass in fourteen asthmatics undergoing long-term treatment with systemically applied corticosteroids. The extent of steroid-induced bone loss was judged by vertebral bone density of the lumbar spine measured by dual-photon absorptiometry as well as by vertebral crush fracture incidence examined by conventional X-ray. Results of the measurements before treatment and after six mo were compared with those of an untreated control group of nineteen asthmatics. Bone density increased during the observation period by 5% in the treated group, compared with a decrease of 4.3% in the untreated control group (p < 0.01). Moreover, in the treated group no radiologically visible new fractures occurred; in the control group new fractures were observed in four patients. There were no serious side effects of the applied drugs during the 6-mo period. Therefore, the combination of EHDP, calcium, and vitamin D appears to be a useful regimen for the management of steroid-induced bone loss in adult asthmatics.

Adrenal Cortex Hormones↗
PubMed1994

[Does the choice of a reference system modify the analysis of ergospirometric values?].

The importance of the reference system (arbitrary abscissa units) for the analysis of the time courses of cardiopulmonary exercise test indices was assessed. Ten untrained students, 10 athletes, and 10 triathletes performed an exhaustion-limited cycling test. The courses of 20 pulmonary and hemodynamic indices were investigated with respect to the reference systems "heart rate," "relative and absolute oxygen consumption," "power," and a newly developed index "power-duration-product." Most of the significant differences were observed by reference to the power-duration-product. When using the power-duration-product as reference, the courses of eight indices differed significantly between students and triathletes, the courses of five indices between students and athletes, and the course of one index between athletes and triathletes. Since the number of the significant differences between the groups, as well as the courses themselves, depended clearly on the underlying reference system, the choice of the reference system must be considered as an important determinant for the analysis of cardiopulmonary exercise tests.

Adult↗
PubMed1994

Techniques and impact of education in adult asthmatics.

A major cause for the discrepancy between the increase of mortality and morbidity due to asthma and advances in clinical assessment and treatment of the disease is inefficient asthma management. Patient education is a powerful tool for helping patients to gain the motivation and skills to control their asthma. An effective teaching and treatment programme for asthmatics should include information about the disease, prevention and treatment of asthma attacks and bronchial infections, and training of self-management of airflow limitation by the patients. On the basis of the currently evaluated programmes for asthmatic adults, patient education diminishes the frequency of asthma attacks and decreases the disability of the patients. By a reduction of emergency treatments, hospitalizations, and days lost from work a decrease in the costs of the often life-long treatment of asthmatics can be expected. Therefore, patient education should be an integrated part of current asthma management.

Adult↗
PubMed1993

[Pharmacologic characterization of formoterol in comparison with isoprenaline, fenoterol and salbutamol in tracheal muscle strips and lung membranes of the guinea pig].

In severe asthma attacks, beta 2-sympathomimetics can lose part of their therapeutic potency possibly due to a predominance of contractile mediators. To elucidate this loss of potency, we chose tracheal smooth muscle strips as experimental model which were partially and maximally precontracted with 100 and 6,000 nmol/l carbachol, respectively, reflecting different contractile states of the smooth muscle strips. Both contractures were dose-dependently relaxed by fenoterol and salbutamol which are well established as beta 2-sympathomimetics, by a new compound (formoterol) and by isoprenaline as standard. In tracheal strips, partially precontracted with 100 nmol/l carbachol, all agonists induced maximum relaxation beyond basal tone thereby characterized as full agonists. In maximally precontracted tracheal strips beta-adrenergic relaxation was markedly attenuated for all agonists by 70-80%. Maximum relaxation by the beta 2-sympathomimetics was even smaller than that of isoprenaline. By these experiments, the beta 2-sympathomimetics were characterized as partial agonists. The intrinsic 'activities (IA) for relaxation were different for the 3 beta 2-sympathomimetics investigated. Intrinsic activities were 0.8, 0.6 and 0.6 for formoterol, fenoterol and salbutamol, respectively. In both group of experiments formoterol exhibited the lowest EC50 for relaxation, which was 20 and 50 times lower than that of fenoterol and salbutamol, respectively. To investigate, if the higher relaxant potency of formoterol correlated to a higher binding affinity for beta 2-adrenoceptors, we performed radioligand binding experiments in guinea pig lung membranes. The non-linear regression analysis of data revealed a high affinity of formoterol, which was 16- and 40-fold higher than that of fenoterol and salbutamol, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1992

Formoterol, fenoterol, and salbutamol as partial agonists for relaxation of maximally contracted guinea pig tracheae: comparison of relaxation with receptor binding.

In severe asthma attacks beta 2-sympathomimetics lose part of their therapeutic efficiency. To elucidate this loss of efficiency in an experimental model we compared the relaxant potency of salbutamol (SAL), fenoterol (FEN), formoterol (FOR), and (-)-isoprenaline (ISO) in guinea pig tracheae partially and maximally precontracted by 0.1 and 60 mumol/L carbachol, respectively. In partially precontracted tracheae the beta 2-sympathomimetics exerted maximum relaxation in comparison with ISO and low EC50S (nmol/L) for relaxation (SAL, 20; FEN, 5.6; FOR, 0.28; and ISO, 2.5). In maximally precontracted tracheae, however, the beta 2-sympathomimetics were only partial agonists for relaxation with reduced intrinsic activities (%) in comparison to ISO (SAL, 59%; FEN, 61%; FOR, 76%) and significantly increased EC50S (nmol/L) for relaxation (SAL, 130; FEN, 57; FOR, 3.0; ISO, 37). To investigate if the high relaxant potency of FOR is correlated with a higher binding affinity and/or a higher intrinsic activity for adenylate cyclase stimulation than for FEN and SAL, we performed experiments in receptor membranes from guinea pig lung. Binding competition of SAL, FEN, and FOR with [3H]ICI 118,551 for lung beta 2-adrenoceptors yielded dissociation constants (KD) of 320 (SAL), 120 (FEN), and 7.6 (FOR) nmol/L, which exhibited the same ranking as EC50S for relaxation. Concentrations of SAL, FEN, and FOR equivalent to 100 KD of the respective dissociation constants stimulated beta 2-adrenoceptor-coupled adenylate cyclase with different intrinsic activities (%) incomparison to ISO (SAL, 61%; FEN, 63%; FOR, 89%) matching intrinsic activities for relaxation. From these experiments it may be concluded that FOR might improve drug therapy of severe asthma not only due to its long mode of action discovered in clinical studies but also due to its high intrinsic activity and receptor affinity.

Adenylyl Cyclases↗
PubMed1992

The power-duration product--evaluation of a new reference system for cardiopulmonary exercise testing.

The aim of this study was to assess the discriminatory power of the new reference system, power-duration product (PDP), for the analysis of haemodynamic and metabolic variables derived from cardiopulmonary exercise tests. The PDP was calculated as the cumulative index of the product of power (W) times the duration (minutes) of each individual exercise step. The study comprised 30 healthy male volunteers, who were classified into three groups with respect to their regular physical activity: 10 untrained medical students (students), 10 sprinters and long-jumpers (athletes) and 10 endurance athletes performing triathlon (triathletes). Twenty metabolic and haemodynamic variables were recorded throughout exhaustion-limited cycling ergometry. The data were analysed with respect to five reference systems (heart rate, relative and absolute oxygen consumption/body surface area, power, and PDP). A total of 14 differences between modified time courses of haemodynamic and metabolic variables in the three groups of volunteers were observed by reference to PDP, 12 by reference to relative oxygen consumption/body surface area, 11 by reference to heart rate, 8 by reference to absolute oxygen consumption/body surface area, and 7 by reference to power. When using PDP as the reference, the time courses of 8 parameters differed significantly between students and triathletes, 5 between students and athletes, and 1 between athletes and triathletes. In addition to its discriminatory superiority for the comparison of different groups characterized by different cardiopulmonary training and endurance, it was found that PDP permitted a better characterization of the individually performed exercise than the consideration of power per se.

Adolescent↗
PubMed1992

[Negative cortisone attitude in patients with bronchial asthma].

Patients with bronchial asthma often exhibit irrational fears of cortisone medication beyond justified worries about side-effects. A negative cortisone image, which means overemphasizing the damaging and threatening aspects of cortisone, often underlies non-compliant illness behaviour. In the present study, cortisone image was investigated in 54 patients with bronchial asthma before and after participation in the Düsseldorf Asthma treatment and teaching programme (ATTP) and one year later. By participating in ATTP, a significant reduction of the negative cortisone image and thus a more realistic view of cortisone could be achieved in most patients. This effect was also evident at the follow-up examination one year later. On the other hand, persistence of a negative cortisone image in a subgroup of patients turned out to be a potent predictor of later non-compliant illness behaviour. Psychological implications of a persistent negative cortisone image are discussed.

Adult↗
PubMed1992

[Affective-cognitive coping with attacks and illness behavior in patients with bronchial asthma].

The purpose of this study was to investigate attack-related cognitive coping styles in 80 patients with bronchial asthma and to relate them to outcome parameters of illness behaviour. All patients had participated in a 5-day-lasting asthma treatment and teaching programme (ATTP). Outcome variables to be predicted were: The number of days in hospital due to asthma during the year following the training programme and the patients' adherence to the recommendations of the programme one year later. Independent predictor variables were: pre-training attack frequency, hospitalization due to asthma, medication intensity, pulmonary function, asthma symptom anxiety, trait anxiety and attack-related cognitive coping styles. Multiple regression analyses show the importance of a "minimizing/self-confident" coping style in predicting days in hospital, while a "diverting" style predicts best a poor management of attacks in patients on oral steroids.

Adaptation, Psychological↗
PubMed1991

Evaluation of a structured treatment and teaching programme on asthma.

The objective of this study was to evaluate a structured treatment and teaching programme for adult patients with moderate to severe asthma. The design consisted of a prospective, before-after trial: the same consecutive patients were studied before and after intervention with observation periods 1 year before and 1 year after intervention. The investigation took place within a tertiary care centre (university hospital). A total of 142 consecutive patients were referred for in-patient treatment of their asthma, of whom 132 (93%) patients participated in the follow-up examination. The intervention consisted of a structured 5-d in-patient treatment and teaching programme presented by a specialized nurse educator. The aim of the programme was for the patient to assume greater responsibility for disease management, including self-monitoring of peak expiratory flow and qualified self-adaptation of drug therapy. The main outcome measures were the frequency of severe asthma attacks, hospitalization, and absenteeism from work (data provided by health insurance companies), patients' compliance and management skills. During the year before and the year after the intervention 71% and 36%, respectively of patients had one or more severe asthma attacks (mean difference 35%, 95% CI: 25-45%, P less than 0.0001). The percentage of patients who were hospitalized because of asthma decreased from 39% to 22% (mean difference 17%, 95% CI: 7-27%, P less than 0.002). The percentage of employed patients (n = 67) who were absent from work because of asthma decreased from 60% to 43% (mean difference 17%, 95% CI: 4-30%, P less than 0.04). The patients' adherence to maintenance drug therapy and their management skills improved significantly. It was concluded that the participation of patients with moderate to severe asthma in a structured treatment and teaching programme resulted in a substantial reduction in asthma morbidity in the year following the intervention.

Absenteeism↗
PubMed1990

Patient education in asthmatic adults.

Despite the advances in the understanding of the pathogenic mechanisms, clinical assessment, and medical treatment of asthma, an increase of mortality and morbidity has been observed. It is clear from several studies, however, that this discrepancy may be at least partly due to serious defects, among asthmatic patients, in the ability to judge the severity of their asthma, and in the knowledge of medication and the correct action to take, when deterioration occurred. Therefore, to effectively manage asthma, structured education programs for adult asthmatics appear to be useful including information about the disease and the medication as well as training of self-management of airflow limitation by the patients. The evaluation of the course of the disease before and after the education revealed a reduction of severe attacks, hospitalizations, and days lost from work in trained asthmatics.

Adult↗
PubMed1990

Peripheral neuropathies in patients with chronic obstructive pulmonary disease: a multicenter prevalence study.

To investigate the prevalence and type of peripheral neuropathies (PNP) in patients with chronic obstructive pulmonary disease (COPD), we studied lung function and blood gases, clinical signs of PNP, and neurophysiological function in 151 patients with COPD without known risk factors for PNP. Mean (SD) age was 65 (10) years, mean arterial PO2 was 59 (9) mmHg, mean ratio of forced expiratory volume in the first second to vital capacity (FEV1.0/VC) was 42 (12%). Thirty patients (20%) had clinically detectable and 6 (4%) had subclinical PNP of mild degree. Fourteen (9%) of the patients with clinically detectable PNP had symptoms due to PNP. Prevalence of PNP increased with severity of hypoxemia (p less than 0.05) and was more pronounced in the lower than in the upper limbs. Age and the degree of hypoxemia were predictors to differentiate between COPD patients with and without PNP. Although the cause of PNP in COPD patients remains unknown, our observations suggest that chronic hypoxemia may contribute to PNP.

Adult↗
PubMed1990

Comparative analysis of arterial oxygen saturations during exercise by pulse oximetry, photometric measurements, and calculation procedures.

Pulse oximetry allows non-invasive monitoring of arterial oxygen saturation (SO2). To study the validity of pulse oximetry, comparative measurements were performed. During exhaustion limited exercise SO2-values measured by pulse oximetry (SO2puls), calculated SO2-values (algorithms of Kelman, Severinghaus, and Siggaard-Andersen--SO2calc), and as "golden standard" photometric measured SO2-values (SO2meas) were compared. Fourteen triathletes performed a stepwise cycling exercise test in the supine position. SO2calc was determined on the basis of capillary actual blood gas values. SO2puls was measured continuously with a finger probe attached to the second finger. The SO2puls- and SO2calc-values differed from the SO2meas-values (p less than 0.05); however, the differences were of no clinical relevance. Performing linear regression analysis, only SO2puls correlated significantly (r = 0.47, p less than 0.001) with SO2meas. Pulse oximetry is able to replace invasive measurements of arterial oxygen saturation in athletes. It is superior to SO2-calculations and permits reliable, valid and non-invasive continuous monitoring of SO2.

Adult↗
PubMed1990

[Diagnosis, prevention and therapy of pulmonary complications in heart surgery interventions].

Pulmonary complications after cardiac surgery may be caused by preexisting disorders of the respiratory system, common risk factors (e.g., smoking), kind and duration of the surgical procedure, and the anesthesia performed. Preoperative lung function measurements do not allow a valid assessment of the frequency and severity of postoperative complications. However, the efficacy of the peroperative management with bronchodilating agents (beta 2-agonists, theophylline, corticosteroids) in patients with airflow limitation should be based on repeated lung-function testing. After coronary artery surgery, the internal mammary artery grafting produces a greater impairment of lung function than does saphenous vein grafting. In patients with mitral valve disease and pulmonary congestion without increased pulmonary vascular resistance lung-function may be improved by mitral valve replacement. Atelectasis and gas-exchange disturbances during anesthesia can be treated by ventilation with PEEP. An adequate and immediate management of postoperative pulmonary complications (atelectasis, respiratory failure, pneumonia) improves the outcome of patients after cardiac surgery. The role of perioperative physiotherapy for the reduction of pulmonary complications after cardiac surgery is not well established.

Coronary Artery Bypass↗
PubMed1990

[Long-term therapy with almitrine dimesilate has no effect on pulmonary hemodynamics at rest and during stress].

A 6-month double-blind study was conducted in 26 patients suffering from a severe obstructive disturbance of ventilation and respiratory insufficiency to find out the behaviour of blood gases and pulmonary haemodynamics under Almitrin treatment compared with placebo. The acute administration of 75 mg Almitrin resulted in a significant increase of PaO2 by 11.7 mmHg, as well as of PAPR by 4.4 mmHg. Statistical significance was seen only for the systolic pressure of the a. pulmonalis. After subsequent 6-month treatment with 3 x 25 mg Almitrin, a significantly higher PaO2 is seen at T6 than in the control group. Another additional administration of 75 mg Almitrin results in a further increase of PaO2 by 7.7 mmHg. At T6 the behaviour of pulmonary haemodynamics is identical in both groups A and P.

Almitrine↗