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Biomedical subjects

S Groth

Publications and source records attributed to S Groth.

At least 55 records · Page 3Linked to original sources
PubMed1989

Technetium-99m DTPA does not break down during ultrasound nebulization.

For several years aerosolized 99Tcm-DTPA has been used for studies of pulmonary permeability. Comparable results have been obtained regardless of the 99Tcm-DTPA having been nebulized in an ultrasound nebulizer or a jet nebulizer. It was therefore surprising when in a recent study it was observed that more than 90% of a commercially available 99Tcm-DTPA (Squibb) was dissociated into 99TcmO4- and DTPA during ultrasound nebulization. To verify this observation we performed chromatography of seven commercially available DTPA-labelling kits (including that of Squibb). Four different test preparations of each of the kits were analysed: (1) stock solution of 99Tcm-DTPA; (2) heated (80 degrees C) 99Tcm-DTPA; (3) 99Tcm-DTPA nebulized by a DeVilbiss ultrasound nebulizer; (4) 99Tcm-DTPA nebulized by a Varic ultrasound nebulizer. In no case were we able to demonstrate more than 1.0% reduced pertechnetate (99TcmO2) or more than 0.9% free 99TcmO4- after either heating or ultrasound nebulization. A maximum of 5.6% 99TcmO2 could be demonstrated in the stock solution if chromatography was done immediately after the preparation, but only 15 min later no more than 0.9% 99TcmO2 was present. We conclude that there is no essential chemical breakdown of 99Tcm-DTPA during ultrasound nebulization. Caution should be taken not to use the 99Tcm-DTPA until 15 min after its preparation.

Aerosols↗
PubMed1989

Effect of change in particle number on pulmonary clearance of aerosolized 99mTc-DTPA.

Pulmonary clearance (PCl) of inhaled aerosolized 99mTc-diethylenetriamine pentaacetic acid (DTPA) across the alveolocapillary membrane is diffusion limited. Therefore, if the mixing of the 99mTc-DTPA in the aqueous hypophase underlying surfactant is slow or incomplete or if there were no hypophase, an increase in the alveolar surface area occupied by 99mTc-DTPA particles would increase the absorption rate. The aim of this study was to examine whether there is an effect on PCl of changing the number of inhaled particles. The change in particle number was accomplished by a setup of four parallel jet nebulizers feeding a central delivery chamber of 400 cm3. We performed two kinds of experiments in eight healthy nonsmokers between 28 and 52 yr of age. In the first experiment, 99mTc-DTPA in saline was nebulized in one nebulizer, while saline was nebulized in the other three. In the second experiment the number of inhaled particles containing 99mTc-DTPA was increased by a factor of four by nebulizing 99mTc-DTPA in saline in all four nebulizers simultaneously. Increasing the number of inhaled 99mTc-DTPA particles caused an increase in PCl of 24.2% (P less than 0.01). We conclude that there is a slight but significant effect of changing the number of DTPA particles on PCl and that this is probably due to an uneven mixing of the 99mTc-DTPA in the aqueous hypophase underlying the surfactant lining and the alveoli.

Adult↗
PubMed1989

Pulmonary permeability in never-smokers between 21 and 67 yr of age.

During the last 5-10 years, measurements of pulmonary clearance (PCl) of aerosolized 99mTc-labeled diethylenetriamine pentaacetic acid (99mTC-DTPA) have become increasingly used as an index of pulmonary epithelial injury. The aim of this study was to apply a carefully defined procedure for measurements of PCl in healthy nonsmoking individuals and analyze whether sex, age, and height are clinically relevant confounders contributing to the range of interindividual variation. Measurements of regional ventilation (V) and perfusion (Q) were included to analyze whether these indexes are influenced by the same confounders. We studied 39 males and females between 21 and 67 yr of age. Average PCl of the lungs was 0.85 +/- 0.25%.min-1. There was a significant difference between PCl of the central and peripheral parts of the lungs (P less than 0.01). Regional V and Q were greater in the lower than in the upper halves of the lungs (P less than 0.01). There was no relation between PCl, V, or Q and the sex, age, and height of the individuals. It is concluded that when measuring PCl in adult individuals anthropometric measurements need not be considered.

Adult↗
PubMed1989

Occupational lung function impairment in never-smoking Danish welders.

In order to study the effect of welding fumes on lung function, 74 high-exposed welders and 31 age-matched electricians were examined in 1982. None had ever smoked tobacco or been exposed to known or potentially noxious agents to the lungs. A significant difference was found between the welders and the control group in vital capacity, total lung capacity, forced expiratory volume in one second, peak expiratory flow rate, maximal expiratory flow rate at 75% of vital capacity, diffusion capacity and slope of the alveolar plateau. The lungs of the welders were physiologically 10-15 years older than those of the control group. Thirty percent of the welders had a well defined respiratory disease. Their lung function impairment was predominantly obstructive (16 persons), but restrictive patterns were also seen (6 persons).

Adult↗
PubMed1989

Screening of kidney function by plasma creatinine and single-sample 51Cr-EDTA clearance determination--a comparison.

Nomograms or simple formulas have been suggested for estimating the glomerular filtration rate (GFR) from either plasma creatinine (ClK) or from a single plasma sample drawn after an intravenous injection of 51Cr-EDTA (ClA/B). This study compares the precision of estimating GFR as ClK and ClA/B. A multiple plasma-sample standard method (ClSM) served as reference. The comparison was performed in 136 individuals. The variance of ClA/B on ClSM was 14.4 ml/min/1.73 m2 while the variance of ClK on ClSM was 204.5 ml/min/1.73 m2. It is concluded that the ClA/B values are more precise than the ClK values (p less than 0.01). The single-sample method for determination of 51Cr-EDTA clearance seems well-suited for evaluation and monitoring of patients with known or suspected kidney diseases. It may even be applied for screening purposes in cases where plasma creatinine would otherwise have been chosen instead of the usual resource-demanding method for determination of ClSM.

Chromium Radioisotopes↗
PubMed1989

Determination of 51Cr-EDTA clearance between 15 and 40 ml/min/1.73 m2 by a single plasma sample.

A single-sample method for calculation of 51Cr-EDTA clearance (Cl) between 15 and 40 ml/min/1.73 m2 (ClB) is introduced. It was tested in 109 consecutive patients and compared with a previously published single-sample method for calculation of Cl for Cl greater than or equal to 30 ml/min/1.73 m2 (ClA). When Cl less than 40 ml/min/1.73 m2 the results were more precise when calculated as ClB than when calculated as ClA (p greater than or equal to 0.05). The ClA values were more precise than the ClB values when Cl was greater than or equal to 40 ml/min/1.73 m2 (p less than 0.01). Used in combination (ClA/B) there was a close correlation with Cl (r = 0.98) for the whole range of tested clearance values. It is concluded that Cl can be precisely determined by combined use of the two methods, provided Cl greater than 15 ml/min/1.73 m2 and the single blood-sample is drawn between 240 and 300 min after the injection. If ClA/B less than or equal to 15 ml/min/1.73 m2 it is recommended that a second blood-sample be drawn after 24 h and that Cl is calculated by a conventional slope method.

Chromium Radioisotopes↗
PubMed1989

The effect of thoracic irradiation for cancer of the breast on ventilation, perfusion and pulmonary permeability. A one-year follow-up.

Regional and overall lung function was studied in 14 women during a one-year follow-up after postmastectomy irradiation for cancer of the breast. The dose was 40 Gy in the chest wall and 20-40 Gy in the apex of the lung. Immediately after irradiation there was a slight increase in pulmonary clearance of 99TCm-DTPA compared to baseline values. This increase, however, was not restricted to the field of irradiation. Three months after irradiation there were regional defects in the ventilation and perfusion scintigrams in 11 of the patients. At the same time there was a greater decrease in total lung capacity, vital capacity and diffusion capacity for CO than in ventilation and perfusion. One year after irradiation the lung function impairment had only insignificantly regressed. It is concluded that local lung irradiation may cause persistent regional and generalized lung function impairment. The early increase in pulmonary clearance of 99Tcm-DTPA could not be used as a predictor of subsequent lung function impairment.

Adult↗
PubMed1989

Diabetes mellitus, plasma glucose and lung function in a cross-sectional population study.

To assess possible associations between diabetes mellitus (DM), plasma glucose, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), we analysed the results from a cross-sectional study of 11,763 subjects. The subjects were 20 yrs of age or older and were representative of the population of Copenhagen City. Two hundred and eighty four of the participants had DM as assessed by questionnaire. One hundred and seven subjects who did not report having DM had a plasma concentration of glucose higher than or equal to 11.1 mmol.l-1. In all age groups of diabetic subjects there was a slight impairment of lung function. It was more prominent in diabetic subjects treated with insulin than in subjects treated with oral hypoglycaemic agents and/or diet. Even in subjects without known DM, there was a significant association between reduction in lung function and raised plasma glucose concentration. On average, FVC (and FEV1) was reduced by 334 ml (and 239 ml) in diabetic subjects treated with insulin, and by 184 ml (and 117 ml) in diabetic subjects treated with hypoglycaemic agents and/or diet compared to control subjects.

Adult↗
PubMed1989

Pulmonary permeability in primary ciliary dyskinesia.

Pulmonary clearance (Pcl) of aerosolized 99mTc-DTPA was studied in fourteen patients with primary ciliary dyskinesia (PCD), (median age 23.5 yrs, range 12-44 yrs) and nine normal individuals (median age 23 yrs, range 18-27 yrs). All had never smoked. Regional Pcl was studied for arbitrarily defined central and peripheral regions of the lung using a gamma camera method, whilst total Pcl was studied by a plasma sample method. The patients with PCD had significantly reduced total Pcl compared to the normal individuals (p less than 0.05) and also significantly lower total lung capacity (TLC), vital capacity (VC), forced expiratory volume in one second (FEV1), and FEV1/VC values (p less than 0.05). There was no correlation between Pcl and FEV1/VC. It is concluded that the reduced Pcl in the PCD patients may be associated with their small lung volumes. In addition, reduced bronchial clearance of surfactant in PCD may be associated with an increased alveolar lining fluid volume and/or an impaired movement of 99mTc-DTPA along the alveolar septa to the bronchoalveolar junction, where the epithelium may be more specialized for absorption.

Adolescent↗
PubMed1989

Bronchoscintigraphic visualization of the acute effect of tobacco exposure and terbutaline on mucociliary clearance in smokers.

The aim of this study was to examine the acute effect of tobacco smoke exposure and inhaled terbutaline on mucociliary clearance in 9 healthy smokers. It was based on a recently described method for scintigraphic visualization of the bronchi (bronchoscintigraphy). After an initial bronchoscintigram had been made by having the subjects inhale aerosolized 99mTc-albumin, they inhaled either terbutaline or placebo from a metered-dose inhaler. Subsequently, data acquisition for production of bronchoscintigrams was repeated at 10 min intervals for 120 min, and the mucociliary clearance was estimated from the movement of radioactivity in the series of bronchoscintigrams thus obtained. On two study days the subjects remained tobacco abstinent, while on two occasions they chain-smoked during the examination. Acute tobacco exposure resulted in an increased clearance rate in the lobar bronchi in 8 of the 9 smokers (p less than 0.03), while in the main bronchi and the trachea the effect was inconsistent. In all subjects terbutaline systematically increased the clearance rate in all visible bronchial structures compared to placebo (p less than 0.04). The combination of smoking and terbutaline caused a faster clearance rate in the lobar bronchi in most subjects than tobacco smoke or terbutaline alone. It is concluded that both acute tobacco exposure and terbutaline increase mucociliary clearance in healthy smokers.

Adult↗
PubMed1989

Effects of smoking and changes in smoking habits on the decline of FEV1.

The aim of this study was to examine the effects of cigarette smoking and changes in smoking habits on the decline of forced expiratory volume in the first second of expiration (FEV1). We studied 7,764 men and women for 5 yrs. The subjects were grouped according to self-reported smoking habits during the observation period. We found that persistent cigarette smoking, in particular heavy smoking, accelerated the decline in FEV1. In 310 subjects who quitted smoking during the observation period, the decline of FEV1 was less pronounced than the decline observed in persistent smokers. In subjects younger than 55 yrs of age, smoking reduction was associated with a less pronounced FEV1 decline, while in the elderly subjects smoking reduction had no effect on the FEV1 decline. An increase in the number of cigarettes smoked was generally associated with a more rapid decline of FEV1, while the beginning of smoking during the 5 yrs of observation did not seem to influence the decline of FEV1. We conclude that smoking cessation or reduction may lead to a demonstrable beneficial effect on the FEV1 decline within a few years.

Age Factors↗
PubMed1988

High-dose local steroid treatment in bronchopulmonary aspergillosis. A pilot study.

Two patients with allergic bronchopulmonary aspergillosis (ABPA) have been treated with a high dose (1600 micrograms daily) of inhaled corticosteroid for 18 months. A beneficial effect with regard to asthmatic symptoms was observed in both patients. During the first 14 months of the observation period no significant changes were observed in lung function parameters. Bronchial histamine challenge showed decreased hyperreactivity. IgE decreased in both patients, while specific IgE and IgG remained the same. After 14 months of treatment one of the patients developed severe, acute exacerbation of the ABPA and was treated with high-dose prednisolone and local steroid. The patient is now fully recovered and has continued on local steroid therapy. The other patient had no episodes of exacerbation and remains stable on this treatment.

Administration, Topical↗
PubMed1988

Determination of the mean transit time for the transport of aerosolized 99mTc-DTPA across the pulmonary epithelial membrane. A plasma sample method.

During the last decade it has been customary to estimate pulmonary epithelial permeability (P-P) as the pulmonary clearance of inhaled nebulized 99mTc-DTPA from a time-activity (t-a) curve registered externally by monitoring over the chest. The t-a curve, however, is not defined by the degree of P-P alone but also by factors such as the deposition of the 99mTc-DTPA in the lungs. To avoid these problems a plasma sample method was derived. It describes P-P by the mean transit time (t) for the transport of 99mTc-DTPA across the pulmonary epithelial membrane, t(L). The calculation of t(L) involves two steps. Following the inhalation of Tc-DTPA the plasma t-a curve is defined and used to calculate t for the transport for 99mTc-DTPA across the pulmonary epithelial membrane, through the ECV and until elimination by the kidneys, t(L+ECV). Subsequently, 99mTc-DTPA is injected as a bolus i.v. and the new t-a curve is used to calculate t for the transport of 99mTc-DTPA through ECV to the kidneys, t(ECV). Finally t(L) is calculated as t(L) = -t(L + ECV) t(ECV). We applied the method in nine non-smoking individuals (median age 25.5 years, range 20-28) and compared the results to t as calculated from the initial slope of an externally derived t-a curve. The individual t(L) values were systematically greater than those of the external detection method (P less than 0.05). It is concluded that the initial slope method overestimates total PC1 as measured by the plasma sample method. When choosing between the two methods, special interest should be paid to the inherent problems of the methods.

Adult↗