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Biomedical subjects

L Frølund

Publications and source records attributed to L Frølund.

At least 73 records · Page 4Linked to original sources
PubMed1987

Reproducibility of challenge tests at different times.

Bronchial challenge for determination of bronchial reactivity is widely used in the diagnosis of asthma, the grading of severity, and evaluation of effect of treatment with new antiasthmatic drugs. Allergen challenge is also used for diagnosis of specific IgE-mediated asthma and evaluation of the effect of immunotherapy. A number of factors influence the result of the challenge test including the selection of patients, criteria for carrying out the challenge test, a number of technical factors concerning the challenge, the dosing schedule, pulmonary function tests carried out and analysis of the data. All these factors have to be taken into consideration before reproducible challenge tests can be performed. Detailed description of the equipment and procedures used and inclusion criteria for the patients should be included in all publications concerning challenge tests in order to be able to compare results from different laboratories. Each clinic or laboratory needs to perform reproducibility studies on bronchial challenge testing procedures and equipment used in their clinic.

Aerosols↗
PubMed1986

Thyroid function after surgical treatment of nontoxic goitre. A randomized study of postoperative thyroxine administration.

Following thyroid resection for nontoxic goitre, 29 euthyroid patients were randomly allocated to no medication or to 0.2 mg levothyroxine daily (17 and 12 patients). The two groups were comparable in age, sex, extent of surgery and thyroid pathology. The patients were free from other endocrine disorders and had no other medication. Serum TSH, T4 and T3 were measured and T3-resin test performed preoperatively and 14 days and 3, 6, 12 and 18 months postoperatively. All values were within normal range. Only at the 3-month follow-up could statistically significant intergroup differences be observed, with T4 higher in the thyroxine-treated and TSH higher in the untreated group, but the outset values were thereafter regained. The T3 values in both groups were slightly reduced immediately after the operation. There was no recurrence of goitre in the 18-month observation period, and none of the findings suggested that routine thyroxine treatment is of value after resection of nontoxic goitre "in Denmark".

Adult↗
PubMed1986

Reproducibility of standardized bronchial allergen provocation test.

Standardized bronchial allergen provocation was performed twice (with an interval of median 14 days (range 14-44)) in 19 extrinsic, well-defined asthmatic patients to study the reproducibility of the bronchial response. Smoking and medications were strictly withheld prior to the provocation. Ten-fold increasing concentrations of allergen solution 0.9 ml were inhaled by tidal volume breathing for 5 min at 10-min intervals. The actual dose given was expressed by the concentration of the solution used. Forced expiratory volume in the first second (FEV1) was used to determine responses, and the provocation continued until an allergen concentration (allergen PC20) was reached which caused at least 20% decrease of the post-saline FEV1. All provocations were followed by a bronchial reaction within clinically acceptable limits. The reproducibility was high, evaluated by the Spearman rank correlation coefficient Rho = 0.90 (P less than 0.01). It is concluded that bronchial provocation with allergens performed as outlined in this study represents a reproducible test which can be applied in routine allergy diagnostics, and in further investigations concerning specific bronchial reactivity.

Allergens↗
PubMed1986

Bronchial histamine challenge in the diagnosis of asthma. The predictive value of changes in airway resistance determined by the interrupter method.

The predictive value of a bronchial challenge with histamine was determined in a prospective survey on a population with a high prevalence of asthma (0.62). Without knowledge of the bronchial responsiveness 133 patients were classified as asthmatics (83) or non-asthmatics (50) according to variation in peak expiratory flow rate and medical history. Response to challenge was determined by the interrupter method, and the concentration of histamine inducing a 40% increase in resistance to breathing (PC40-Rt) was calculated from the log dose response curve. When defining a positive test as a test giving PC40-Rt-values below 2.00 mg/ml, the predictive value of a positive test was 0.75 and the predictive value of a negative test was 0.72. By decreasing the limit for a positive test to 0.25 mg/ml the corresponding predictive value was increased to 0.91. When further increasing the limit to 4.00 mg/ml the predictive value of a negative test in the diagnosis of asthma was increased to 0.81. The interrupter technique is suitable for diagnostic purposes in the detection and exclusion of bronchial asthma.

Adolescent↗
PubMed1986

Self-administered prophylactic postoperative positive expiratory pressure in thoracic surgery.

Application of self-administered postoperative prophylactic positive expiratory pressure (S-PEP) treatment in addition to conventional physiotherapy was investigated in 75 patients undergoing thoracotomy. Twenty-nine patients used a face-mask set supplied with an expiratory resistance (S-PEP group) and 27 patients used a face-mask set without resistance (control group). The observation period and postoperative treatment with the face-mask was 3 days. In the S-PEP group 13 patients developed radiographic atelectasis during the 3 postoperative days compared to eight patients in the control group (P greater than 0.05). The postoperative PaO2 in the S-PEP group was 0.36 kPa lower than in the control group (P greater than 0.05). We conclude that application of S-PEP postoperatively after thoracotomy in addition to conventional physiotherapy including early mobilization had no beneficial effect in preventing atelectasis, as evaluated by changes in blood gas tensions and chest roentgenograms.

Adolescent↗
PubMed1986

Comparison of two aerosols containing both fenoterol and ipratropium in a high (Duovent) and low (Berodual) concentration, respectively.

Twenty-one stable asthmatic patients were randomly allocated to be treated with either Duovent (ipratropium bromide 40 micrograms and fenoterol 100 micrograms) and Berodual (ipratropium bromide 20 micrograms and fenoterol 50 micrograms) in a cross-over double-blind design over a 12-week period, each treatment period lasting for 6 weeks. During the study, patients used the test medicine 2 puffs 4 times daily. At the day of inclusion, 6 and 12 weeks after start, a dose-response curve was obtained after inhalation of the test medicine used during the previous 6-week period. Asthma symptoms were recorded in a diary card and morning and evening peak flow was measured. Berodual and Duovent showed a significant bronchodilating effect, the effect of Duovent comparatively more pronounced, but the absolute lung function values after Berodual equalized the effect of Duovent. No difference between peak flow values measured in the morning and evening could be demonstrated. We conclude that no preference between either Duovent or Berodual could be established in the treatment of asthma.

Aerosols↗
PubMed1986

A rapid challenge protocol for determination of non-specific bronchial responsiveness.

A rapid method for determination of non-specific bronchial hyperreactivity was developed. Resistance to breathing was determined by a modified expiratory airway interrupter technique and combined with a dosimeter-controlled nebulizer which made continuous determination of response possible during challenge. The patients inhaled histamine chloride 8 mg/ml at every eighth breath until resistance to breathing (Rt) was increased by 60%. The number of inhalations (NI) or the provocative concentration (PC60-Rt) of histamine increasing Rt by 60% were determined in 68 patients. The new method correlated well to a non-cumulative standard protocol and could be terminated either within 10 min or within 20 inhalations. The results of this new challenge procedure enables us to predict the responsiveness to inhaled histamine precisely enough to separate patients into hyperreactive or normal reactive patients. Furthermore, the repeatability of the new method is comparable or superior to that of standard methods. The 95% confidence interval for the difference between replicates was the observed value +/- 2.4 NI. Thus this new method will be suited for studies of drug modifying effect on bronchial hyperreactivity since individual dose titration is easily performed, and the method could be valuable in epidemiological and occupational surveys as well.

Adolescent↗
PubMed1985

Protective effect of a new anti-asthmatic agent (Minocromil) in bronchial allergen challenge tests.

Ten patients were included in a double-blind crossover trial, designed to compare the effects of a new anti-asthmatic agent Minocromil, an organic decarboxylic acid, and placebo on bronchial allergen challenge. The challenges were performed at weekly intervals. Significant differences in favour of Minocromil were found in the concentration of antigen reached at which FEV1 fell below 20% of baseline. This was confirmed by analysis of the decrease in FEV1 recorded at the highest concentrations of antigens, which showed statistically significant differences in favour of Minocromil.

Asthma↗
PubMed1985

Short and long term reproducibility of responsiveness to inhaled histamine: Rt compared to FEV1 as measurement of response to challenge.

Repeatability (123 min) and reproducibility (65 days) of response to inhaled histamine were tested in a selected group of stable asthmatics and non-asthmatics by means of FEV1 and breathing resistance (Rt) determined by the interruptor method. Variation in prechallenge FEV1 and Rt was kept within a +/- 10% and +/- 40% range, respectively. We found the PC20-FEV1 highly repeatable after 123 min. The 95% confidence interval for a single determination was the measured value +/- 1.72 two-fold concentration differences. Reproducibility was significantly lower (p less than 0.05). Both repeatability and reproducibility of PC30-Rt were significantly lower than that of PC20-FEV1. Interruptor method determined PC30-Rt was found repeatable within 4 two-fold concentration differences which is not acceptable for clinical and research purposes. The poor repeatability of PC30-Rt could be due to changes in functional residual capacity during challenge.

Adolescent↗
PubMed1984

Recurrence of nontoxic goitre with and without postoperative thyroxine medication.

The incidence of postoperative recurrence of nontoxic goitre was evaluated in 175 patients. The average observation period was 8.8 years. Levothyroxine (Eltroxin) had been taken by 104 of these patients as long-term prophylaxis against goitre recurrence. Ten (9.5%) of the 104 had recurrence. The other 71 patients received no or only brief thyroxine medication postoperatively. In this group there were eight recurrences (11.3%). The difference was not significant, nor did the two groups differ significantly in regard to sex and age distribution, pathologic anatomy and observation time. Routine long-term administration of thyroxine after thyroid resection is not justified from the results of this study.

Adult↗
PubMed1980

Effect of ketone body infusion on plasma catecholamine and substrate concentrations during acute hypoglycemia in man.

Experimental studies have shown that ketone body infusion inhibits the catecholamine response to hypoglycemia. We have studied six men during insulin-induced hypoglycemia who were concomitantly infused with saline or 3-hydroxybutyrate at dose rates of 4 and 13 mg/kg.min. The mean blood concentrations of 3-hydroxybutyrate increased to about 0.45 and 3 mmol/liter, respectively. The results show that the glucose response to insulin; hypoglycemic symptoms; and the adrenaline, noradrenaline, and cortisol responses to hypoglycemia were not influenced by ketone infusion at any dose rate.

3-Hydroxybutyric Acid↗
PubMedDate not supplied

Allergic contact sensitization in an adult Danish population: two cross-sectional surveys eight years apart (the Copenhagen Allergy Study).

In 1990 and 1998 15-41-year-old people were patch-tested in 2 cross-sectional studies of random samples of the population in the western part of Copenhagen County, Denmark. In 1990, 290 subjects and in 1998, 469 subjects were patch-tested. The participation rates were 69% and 51%, respectively. Contact sensitivity to one or more haptens was found in 15.9% and 18.6% in 1990 and 1998, respectively. Nickel sensitivity is still the most common contact sensitivity. The risk of contact sensitivity to the cosmetic-related haptens included in the series (formaldehyde was not included) increased significantly from 2.4% in 1990 to 5.8% in 1998 (odds ratio 2.44, 95% confidence interval 1.04-5.73). The prevalence of contact sensitivity to cosmetic-related allergens has been doubled between 1990 and 1998.

Adolescent↗
PubMedDate not supplied

Comparison between different techniques for measuring nasal patency in a group of unselected patients.

Many techniques for measuring nasal patency have been developed in search for a reliable, easily performed and reproducible method. Rhinomanometry is easily performed in the clinic but daily records of nasal blocking cannot be obtained. In this study we examined the correlation between posterior rhinomanometry (PR), nasal peak flow (nPF), the ratio nasal patency index (NPI), and the opening interrupter method (Rtn) for measuring nasal patency. Twenty-eight subjects with no symptoms of rhinitis and 20 patients with diagnosed rhinitis were investigated. A significant (p less than 0.05) correlation was found between PR and nPF after stratification according to the diagnosis of rhinitis and between nPF, PR, and height. All other correlations tested proved non-significant. We conclude that PR is the method which ought to be used in the hospital, but nPF is an easy way to measure nasal patency and might even be used by the patient at home.

Adult↗