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Biomedical subjects

S Groth

Publications and source records attributed to S Groth.

At least 73 records · Page 4Linked to original sources

Imaging of the airways by bronchoscintigraphy for the study of mucociliary clearance.

A method for functional imaging of the large airways (bronchoscintigraphy) has been developed. It is based on the administration of aerosolised albumin labelled with technetium-99m using a special inhalation technique to produce central airway deposition. The method was evaluated as a measure of mucociliary clearance by recording the movement of radioactivity in the airways of 11 healthy, non-smoking subjects on two separate days. A series of bronchoscintigrams was acquired at five minute intervals for two hours after termination of the inhalation. After the first bronchoscintigram 1.25 mg terbutaline or placebo was administered from a metered dose inhaler (five puffs) according to a randomised, double blind, crossover design. The scintigrams were evaluated blind. After terbutaline the segmental bronchi were no longer visible after a median time of 10 minutes, the lobar bronchi after 20 minutes and the main bronchi after 30 minutes. In six cases the trachea was cleared after two hours. After placebo the segmental bronchi disappeared after a median of 15 minutes, but at two hours half the lobar bronchi remained visible. In only two cases was it no longer possible to see the main bronchi or the trachea. It is concluded that bronchoscintigraphy can be used to examine regional mucociliary clearance in healthy subjects and that terbutaline significantly increases the clearance of the deposited radioactive aerosol.

Administration, Inhalation↗

Lung function 22-35 years after treatment of idiopathic spontaneous pneumothorax with talc poudrage or simple drainage.

The long term effects on lung function of treatment of idiopathic spontaneous pneumothorax by talc poudrage or simple chest drainage were assessed in 114 patients. Subjects were studied 22-35 years after their first pneumothorax with measurement of static and dynamic lung volumes. Eighty patients had been treated with talc pleurodesis and 34 with simple pleural drainage. At the follow up examination 17 had died from what appear to be unrelated causes and two had emigrated. Of the remainder, 75 participated fully in the study, 14 completed a postal questionnaire, and six failed to respond. The group treated with talc poudrage showed a mild restrictive impairment of lung function with a mean total lung capacity (TLC) of 89% predicted. In subjects treated with simple drainage mean TLC was 96% predicted. One subject treated with talc poudrage had extensive pleural calcification and a substantial reduction in lung function (TLC 58% predicted) with some evidence of lung fibrosis. None of the subjects had developed a mesothelioma. We conclude that, although talc poudrage may cause a mild restrictive impairment of lung function and pleural thickening on the chest radiograph, the long term outlook is good.

Adult↗

Binding and diffusion characteristics of 14C EDTA and 99mTc DTPA in respiratory tract mucus glycoprotein from patients with chronic bronchitis.

Measurement of pulmonary clearance of an inhaled aerosol of technetium-99m labelled diethylenetriaminepenta-acetate (DTPA) by external detection methods has been used widely as an index of permeability across alveolar epithelium and bronchial mucosa. To determine the applicability of the tracer to measurement of permeability in the airways the diffusion and binding characteristics of 99mTc DTPA and the chemically related ethylenediaminetetra-acetic acid labelled with carbon-14 (14C EDTA) was studied in purified respiratory tract mucus glycoprotein from patients with chronic bronchitis. The diffusion coefficients for 99mTc DTPA and 14C EDTA through mucus gels were significantly lower than those for tritiated water. Both molecules bound to the mucus gels with high affinity at two independent low capacity sites. Appreciable amounts of 99mTc DTPA or 14C EDTA are therefore unlikely to cross mucus layers of physiological thickness over periods of four or five hours. This suggests that when pulmonary clearance is determined by the 99mTc DTPA method the tracer retained in mucus lined airways will provide background activity. This study supports the assumption that pulmonary clearance measurements are mainly measuring alveolar epithelial permeability and should not be used to study bronchial epithelial permeability.

Bronchitis↗

Pulmonary function is influenced by heavy alcohol consumption.

To study the possible impact of alcohol consumption on lung function (FEV1 and FVC), we observed 11,135 men and women for 5 yr. Subjects were between 20 and 90 yr of age and were selected so that they were representative of the population of the city of Copenhagen. The study population was stratified according to smoking habits and alcohol consumption. A total of 8,765 persons did not significantly change alcohol or smoking habits during the 5 yr of observation and constituted the study sample. The study sample included 32 women and 301 men with an alcohol consumption of greater than or equal to 350 g/wk (78 were nonsmokers). Multiple regression analysis showed that alcohol consumption significantly accelerated the loss of FEV1 and the loss of FVC with time. Consumption of 350 g of alcohol/wk had an effect on FEV1 comparable to the effect of smoking 15 g of tobacco/day.

Adult↗

Long-term effects on renal function and blood pressure of treatment with cisplatin, vinblastine, and bleomycin in patients with germ cell cancer.

Long-term effects of cisplatin on renal function were investigated in 34 patients with germ cell cancer observed for a median of 65 months (range, 43 to 97 months). All patients achieved a complete remission after treatment with cisplatin (median dose 583 mg/m2), vinblastine, and bleomycin. None of the patients relapsed during follow-up. During treatment the glomerular filtration rate (GFR) decreased by 18% (P less than .05). During follow-up kidney function recovered in ten patients and partly improved in eight patients. Changes in plasma creatinine did not consistently correspond to alterations in GFR. The mean increase in systolic blood pressure during follow-up did not differ from the increase seen in a group of age-matched healthy men. The mean increase in diastolic pressure, however, was significant (P less than .05), but was entirely due to hypertension observed in six patients. Renography of these patients was normal. We conclude that the decrease in GFR observed during treatment with cisplatin is partly reversible. Cisplatin-treated patients have an increased risk of developing hypertension years after treatment.

Adult↗

Health effects due to occupational exposure to cobalt blue dye among plate painters in a porcelain factory in Denmark.

Forty-six plate painters, heavily exposed to cobalt blue dye, took part in this cross-sectional study, and 51 top-glaze painters served as the referents. The study comprised a questionnaire, a health examination, a lung function test, and the determination of the blood and urinary cobalt levels. The plate painters were examined twice, at the end of a workfree period and after resuming work. More plate painters complained of irritation from the mucous membranes in the mouth and throat, cough, and expectoration than the referents. The symptoms increased after the plate painters resumed work. The cobalt level of the plate-painting group after six weeks off work was twice as high in the blood and five times higher in the urine than the corresponding values of the reference group. After the plate painters resumed work, the blood and urinary levels increased approximately 4 and 15 times, respectively. Increased airflow resistance was found in the plate group when compared with the referents, and signs of small airway obstruction increased after the plate painters resumed work. The pulse rate was higher among the plate painters, and minor changes in the red blood cell picture were observed. None of these adverse health effects were associated with the cobalt levels in the blood or urine.

Air Pollutants, Occupational↗

Bronchial effects of leukotriene D4 inhalation in normal human lung.

The aim of the study was to investigate whether inhaled leukotriene (LT) D4 could mimic the characteristics of asthmatic patients after allergen-induced attack, i.e. a prolonged subclinical bronchial obstruction, an increased reactivity of the airways and a late reaction. The effects of LTD4 were compared with those of histamine and the mechanism of action sought. Thirty-three non-atopic individuals participated in the study. The two drugs were inhaled as an aerosol of small particles causing a relative peripheral deposition pattern in order to mimic the preferential involvement of peripheral airways in asthmatic patients out of attack. LTD4 caused a dose-dependent obstruction of the airways as measured by partial flow-volume curves and volume of trapped gas, yet only minor changes in forced expiratory volume in 1 s (FEV1) and peak expiratory flow rate. LTD4 was 1900-7000 times more potent than histamine. LTD4 inhalations were almost symptomless as opposed to the irritative and dyspnoeic symptoms seen after inhalation of histamine. The time duration for the induced change in partial flow-volume curves was the same for the two drugs. Approximately 30 min elapsed until the bronchial obstruction had decreased by 50% of the maximum effect, and no delayed reaction was observed within 10 h. The reactivity of the airways did not change during 10 h after inhalation of LTD4 as tested by repeated exercise challenges. Pretreatment with ipratropium bromide prevented the effect of LTD4 on FEV1, yet not on partial flow-volume curves. Pretreatment with either cimetidine and mepyramine or with indomethacin, did not affect the bronchial obstruction after LTD4.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗

Regional lung function in long-term survivors after chemotherapy for small cell lung cancer.

In order to evaluate the regional lung function in patients with small cell lung cancer with long-term survival, we measured the regional lung function in 17 patients. We studied the patients with 81m-krypton ventilation scans and 99m-technetium perfusion scans, as well as measurements of static lung volumes (VC, RV, TLC), flow volume indices (FEV1, FVC, MEF50), and carbon monoxide diffusing capacity (DLCO). We found both the ventilation and the perfusion of the affected lung to be slightly but significantly lower (P less than 0.05), while no obvious ventilation or perfusion defects could be identified at the former tumor site. The static volumes of the lungs, the FVC and the FEV1 were within predicted normal values, while a significant decrease was seen in the PEF, MEF50, and DLCO. It is concluded that patients with small cell lung cancer who obtain complete remission with normalization of the chest X-ray and long-term survival after 18 months of intensive chemotherapy also have a nearly normal lung function.

Aged↗

Mucociliary clearance in early simple chronic bronchitis.

Tracheobronchial mucociliary clearance was measured in 37 patients with early simple chronic bronchitis. A non-invasive radio-aerosol technique with inhalation of 99Tcm labelled 5-microns polystyrene particles followed by assessment of radio-nuclide distribution by posterior gamma-camera scans was employed. The mucociliary clearance of the bronchitics was significantly lower than clearance of a non-smoker control group. An interim analysis of the effect of treatment with a surfactant stimulating drug, ambroxol, suggested a dosage-dependent tendency to a faster mucociliary clearance than seen in placebo-treated bronchitics.

Adult↗

Acute and long-term nephrotoxicity of cis-platinum in man.

To detect whether the nephrotoxicity of cis-diamminedichloroplatinum (DDP) is acute and can be demonstrated at an early stage in man, a method for estimating the function of the kidneys during intensive hydration was devised. The method includes a calculation of the clearance of 125I-orthoiodohippurate and an estimation of the glomerular filtration rate (GFR) from fast changes of the extracellular volume (ECV) and the mean transit time of 99mTc-DTPA in this volume. We examined nine patients with testicular cancer on 2 consecutive days for acute nephrotoxicity while they were undergoing treatment with cis-platinum. Placebo was given on day 1, cis-platinum on day 2. On both days the patients were hydrated with 4 l saline, glucose, and mannitol (0.51) over a period of 4 h, which resulted in an increase of 125I-orthoiodohippurate clearance on both days (P less than 0.01). The increase was, however, lower on the day of treatment with cis-platinum than on the day with placebo (P less than 0.05). There were no acute changes in the GFR. This indicates that treatment with DDP inhibits the active transport of 125I-orthoiodohippurate in the tubules; that is to say there is an acute effect on the kidney function. There were no acute changes in the GFR, but in the long-term followup study we found that the GFR had decreased significantly (P less than 0.05) after 2 months of treatment. During the first year after the initiation of treatment the GFR changes were found to progress. A significant increase in se-creatinine was not observed until 6 months after the initiation of treatment (P less than 0.05). The degree of chronic nephrotoxicity did not correlate in individual patients with the acute changes in kidney function.

Acute Disease↗

Assessment of the relative safety of the beta-blockers ICI 141,292 and atenolol in patients with bronchial asthma.

ICI 141,292 is a beta-blocker with beta 1-selective partial agonist activity. To study its cardioselectivity in humans, comparable beta-blocking doses of 200 mg ICI 141,292 and 100 mg atenolol were given to 12 patients with stable bronchial asthma. Both drugs significantly reduced the midexpiratory flow rate at 50% of vital capacity, whereas no significant reduction in FEV1 or peak expiratory flow rate were observed. It is concluded that the cardioselectivity of ICI 141,292 did not differ significantly from that of atenolol. Since they both had a measurable effect on respiratory mechanics, they should probably not be prescribed in bronchial asthma, or only with the greatest possible caution.

Adult↗

Determination of 99mTc-DTPA clearance by a single plasma sample method.

To derive a formula for determination of 99mTc-DTPA clearance (Cl) from the radioactivity in a single plasma sample, the relation Cl = ECV/t was used, where ECV is the extracellular volume and t is the mean transit time of the tracer in the organism. By studying 99mTc-DTPA time activity curves of 45 consecutive patients we found that ECV could be estimated from the body surface area, and that t could be calculated from the radioactivity in a single plasma sample. Cl calculated by the single sample method was almost identical to Cl calculated by a standard multiple sample method (r = 0.987). It is concluded that the single sample method is accurate and that it may prove useful as a routine method provided that the method is not used in patients with 99mTc-DTPA clearance less than 30 ml min-1, since this investigation includes only patients with Cl greater than 30 ml min-1; the method is not used for children, since the test material did not contain any children; the method is only used for plasma samples drawn at 180 less than or equal to t less than or equal to 300 min.

Adult↗

Regional lung function impairment following post-operative radiotherapy for breast cancer using direct or tangential field techniques.

We have compared the effect of tangential and direct irradiation on regional lung function in 22 consecutive patients with breast cancer, who had been treated by post-operative irradiation 3 months prior to the examination. The tangential technique (total dose 32-36 Gy, less than 5 Gy of the lung) was employed in eight of the patients, while the direct technique (total dose 40 Gy, 5-20 Gy to the lung) was used in the other 14. In the group that had been treated by the tangential technique, there was no impairment of the ventilation or perfusion of the irradiated lung compared with the contralateral lung. The radiographs of the thorax were all normal. In the group that had been treated by the direct technique, there was a reduction in both the ventilation and the perfusion in 12 of the patients (p less than 0.01). The radiographs of the thorax were abnormal in only seven of these 12 patients. In both groups the regional leakiness of the lungs was evaluated as the pulmonary clearance of inhaled nebulised 99Tcm-DTPA. Due to differences in smoking habits between and within the groups, the results were not conclusive. It is concluded that the regional lung function was not significantly affected by the tangential technique, in contrast to a pronounced and harmful effect of the direct technique.

Aged↗