Search PubMed⌕ Search

Biomedical subjects

J Mortensen

Publications and source records attributed to J Mortensen.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Various types of tobacco smoking and development of chronic obstructive pulmonary disease. Results from the Osterbro study].

On the basis of the Osterbro investigation (Copenhagen City Heart Study) which includes several thousand smokers and non-smokers, the authors have analysed the risk of developing chronic mucus hypersecretion and decrease in forced expiration volume in the first second of expiration (FEV1) in the course of a five-year period in the following groups: non-smokers, smokers of cigarettes without filters, smokers of filter cigarettes, smokers of cigarillos/cigars and pipe smokers. All of the types of tobacco investigated led to increased loss of pulmonary function and to increased risk of development of mucus hypersecretion as compared with non-smokers. The differences between the injurious effects of the types of tobacco were limited and were probably due to different inhalation habits in the various groups of smokers. It is concluded that there is no evidence that change from one type of tobacco (eg cigarettes) to another type (eg pipe or cigar tobacco) will reduce the risk of developing chronic obstructive pulmonary disease unless the change is accompanied by considerable reduction of the tobacco consumption.

Adult↗
PubMed1991

Experimental evaluation of furosemide renography in unobstructed and partially obstructed upper urinary tracts in pigs.

To evaluate the reliability and the constancy of the furosemide renography an experimental evaluation of the test has been performed. A standardized unilateral partial proximal ureteral obstruction was applied to 11 pigs. Preoperatively and again weekly in the three weeks following obstruction a furosemide renogram (FR) was done. The furosemide renography was a very constant parameter in the unobstructed kidney (85%) and in the partly obstructed kidney (85%). A type I FR pattern (O'Reilly classification) was an exact indicator of an unobstructed pelvis. After partial ureteral obstruction, an immediate change in the FR pattern was seen either into type II or type IIIa renography. In this experimental study furosemide renography was found to be a reliable tool in the differentiation between the unobstructed normal renal pelves and the partly obstructed dilated renal pelves.

Animals↗
PubMed1991

The effect of forced expirations on mucociliary clearance in patients with chronic bronchitis and in healthy subjects.

Animal studies have shown that frequent coughing may damage the mucociliary apparatus in flow-limiting segments of the central airways. To determine whether mucociliary clearance in humans is affected by repeated dynamic compression associated with forced expirations, we measured pulmonary deposition and mucociliary clearance for 2 h of inhaled [99Tcm]albumin. The subjects inhaled [99Tcm]albumin on 2 study days (randomized) using (A) slow inspirations and forced expirations, while inhalation using (B) forced inspirations and slow expirations served as control. The study was conducted using 10 patients with chronic hypersecretory/obstructive bronchitis and six normal subjects. We found that inhalation of [99Tcm]albumin by the two manoeuvres (A and B) resulted in similar patterns of aerosol deposition. There was no significant difference in retention of radioactivity in the central lung region at 1 h in the patients with chronic bronchitis after inhalation with manoeuvre A (102%) and with manoeuvre B (91.5%), or in the healthy subjects after manoeuvre A (74%) and manoeuvre B (77%). There was also no difference in the retention at 2 h or in overall mucociliary clearance in any of the groups. We conclude that dynamic compression in the central airways associated with forced expiration does not affect bronchial clearance in the airways of healthy subjects or in patients with chronic bronchitis.

Adolescent↗
PubMed1991

Effect of terbutaline on mucociliary clearance in asthmatic and healthy subjects after inhalation from a pressurised inhaler and a dry powder inhaler.

BACKGROUND: beta Agonists have been shown to increase mucociliary clearance in some studies but not all. Whether the formulation of beta agonists affects mucociliary clearance is not known but may be important as the use of dry powder inhalers increases. METHODS: The effect of different methods of administration of inhaled terbutaline on mucociliary clearance and forced expiratory volume in one second (FEV1) was assessed in 10 patients with asthma and 10 healthy subjects. Terbutaline (1 mg) was administered through a metered dose inhaler with a spacer (Nebuhaler) or a dry powder inhaler (Turbuhaler), or both treatments were given, in a four way double blind, double dummy trial. Mucociliary clearance was measured by bronchoscintigraphy. RESULTS: Clearance of radioactivity from the lobar bronchi increased in the asthmatic patients by a median of 32% after terbutaline was given by metered dose inhaler and 55% after a combined dose of 2 mg from both inhalers (1 mg from each) compared with placebo but by only 9% after 1 mg of terbutaline was given by a dry powder inhaler. In the healthy subjects mucociliary clearance increased by 51% when terbutaline was given by a dry powder inhaler, by 66% when given by a metered dose inhaler, and by 66% when given by both inhalers combined. The effect of terbutaline on FEV1 was the same with each of the inhalers. CONCLUSION: Despite similar changes in FEV1 with the two formulations terbutaline increased mucociliary clearance significantly in asthmatic and healthy subjects when inhaled from a metered dose inhaler whereas when it was inhaled from a dry powder inhaler its effect was significant only in healthy subjects. The reason for the difference in asthmatic subjects is unclear, but may be associated with differences in the deposition of terbutaline.

Administration, Inhalation↗
PubMed1991

Effect of substance P on right colonic pressure: a dose response study in pigs.

The purpose of the present investigation was to elucidate the influence and mechanism of the action of substance P (SP) upon intraluminal pressure in proximal porcine colon. In 9 pigs, SP was infused intra-arterially in varying doses from 0.5 to 160 ng/kg/min. Mean baseline colonic pressure was 8.9 mm Hg increasing in a dose-dependent manner to 34.6 mm Hg at an SP dose of 40 ng/kg/min. Hereafter, the colonic pressure remained constant. In other series, SP infusion (5-80 ng/kg) was preceded by infusion of hexamethonium (0.5 mg/kg/min, continuous i.v.; n = 7), atropine (0.01 mg/kg/30 min, i.v.; n = 6), by naloxone (0.01 mg/kg/15 min, i.a.; n = 5) or tetrodotoxin (1 microgram/kg/h, i.a.; n = 7). Atropine significantly inhibited the effect of SP on colonic pressure, whereas the other blockers were without influence on the SP-induced colonic pressure. It is concluded that SP has a potent dose-dependent stimulatory effect upon right colonic intraluminal activity of the pig, mediated partly by atropine-sensitive receptors.

Animals↗
PubMed1991

The effects of postural drainage and positive expiratory pressure physiotherapy on tracheobronchial clearance in cystic fibrosis.

We studied the effects of two chest physiotherapy regimens on whole lung and regional tracheobronchial clearance (TBC) in ten patients with cystic fibrosis. The regimens were given on two separate days and consisted of 20 min of (1) postural drainage and the forced expiration technique (PD + FET), and (2) positive expiratory pressure (PEP-mask) and FET (PEP + FET). A third day served as control. The study days were randomized. Each day, the clearance of lung radioactivity was measured for 3 h by gamma camera. The number of spontaneous coughs was recorded and the sputum expectorated was sampled. We found that both PD + FET and PEP + FET improved whole lung TBC at 30 minutes and 1 h four or fivefold (p less than 0.01) compared with control, whereas at 2 h and 3 h only the improvement following PEP + FET (approximately 1.4 times) was significant (p less than 0.05). There was no significant difference in whole lung or regional TBC between the PD + FET and PEP + FET treatments. The correlations between TBC and the radioactivity content in sputum expectorated (rs2 = 0.76) and between TBC and numbers of coughs (rs2 = 0.65) were better than between TBC and the weight of sputum expectorated (Rs = 0.39). We conclude that PD or PEP when combined with FET have similar effects on short-term whole lung and regional TBC in patients with cystic fibrosis. Evaluation of TBC during chest physiotherapy when only based on the weight of sputum expectorated seems inadequate.

Adolescent↗
PubMed1990

[Tuberculosis in children in Copenhagen during 1975-1985].

During the years 1975-1985, 25 Danish children (less than 15 years) and 40 children of immigrants in the Municipalities of Copenhagen and Frederiksberg had tuberculosis for the first time. The children were assessed at the time of diagnosis and were retraced in 1987. The incidence of tuberculosis among foreign children was 10-40 times that among Danish children. Pronounced differences in the localizations of tuberculosis in Danes and foreigners were observed. Whereas the Danish children had exclusively pulmonary tuberculosis, 13 of the foreign children had either extrapulmonary tuberculosis or pulmonary and extrapulmonary tuberculosis simultaneously. Two of the foreign children had tuberculosis meningitis and one miliary tuberculosis. Significantly more patients with bacillary tuberculosis were present among foreigners than among Danes. No significant differences were found between the occurrence of symptoms, Mantoux-positive reactions, previous Calmette vaccination or known contact with a person with tuberculosis in Danes and foreigners. Treatment was followed as prescribed and all were cured from tuberculosis. One child with tuberculosis meningitis developed slight sequelae while the remainder of the children developed somatically normally.

Adolescent↗
PubMed1990

The impact of unilateral ureteral obstruction on pelvic and parenchymal transit times in the pig kidney.

In 10 female pigs a partial unilateral ureteral obstruction was investigated for 3 weeks. The pigs were monitored with 131I-iodo-hippuran scintigraphies before obstruction and once a week during the course of obstruction. Parenchymal and pelvic mean transit times were calculated by deconvolution analysis. Before the pigs were killed, pelvic pressure and volume were measured. During the course of obstruction there was a slight, but significant (P less than or equal to 0.05) difference in renographical split function between the 2 sides. Parenchymal transit times increased moderately ipsilaterally during the 1st and 2nd week after obstruction and a significant difference (P less than 0.02) appeared in the 2nd week compared to the contralateral side, which was unchanged during the course of obstruction. Pelvic transit times increased steadily ipsilaterally during the course of obstruction and the opposite took place contralaterally. A fair correlation (r = 0.65) was found between parenchymal transit time and pelvic baseline pressure. Pelvic transit times were prolonged at any time after obstruction and significantly correlated to the presence of obstruction. The study suggests that interpretation of the obstructed renogram will encounter analysis of both parenchymal and pelvic transit times in cases where renal function is moderately reduced.

Animals↗
PubMed1990

Fractional gastrointestinal transit time: intra- and interindividual variation.

The intra- and interindividual variation in the gastrointestinal transit times was measured in 12 healthy adult test subjects using a scintigraphic method with 111In marked single unit tablets. Test conditions were semi-standardized. The variation within the same individual was as large as the variation between different subjects regarding the transit times through both the small and the large intestines. The small intestine transit time was 5 h (median) with an interquartile range of 4-7 h. The median transit time through the large intestine was 23.5 h (interquartile range 19.0-40.5 h). The coefficient of repeatability for the small intestinal and large intestinal transit time was 4 h and 33 h respectively. Our conclusion is that the 111In single unit capsule method can be used for measuring the fractional gastrointestinal transit times, but the intra- and interindividual variations are rather large and similar. From a radiation-hygienic point of view the 111In single unit capsule method is acceptable. The large inter- and intraindividual variation in gastrointestinal transit time might be an important factor in the absorption of certain drugs.

Adult↗
PubMed1990

Phlegm production in plain cigarette smokers who changed to filter cigarettes or quit smoking.

Data from a prospective epidemiological study that included 2025 plain cigarette smokers were analysed to investigate the effect of phlegm production of changing to filter cigarettes or quitting smoking. During a 5-year follow-up, 189 subjects quitted smoking, 312 changed to filter cigarettes, while 1524 continued to smoke plain cigarettes. Multiple logistic regression was used to adjust for age, duration of smoking, number of cigarettes smoked, socio-economic status and alcohol consumption. Smokers with morning phlegm at enrollment, who changed to filter cigarettes during the follow-up, had a probability ratio of 1.9 of phlegm production ceasing, compared with smokers who continued to smoke plain cigarettes (P less than 0.05). However, the probability ratio of developing morning phlegm among smokers who changed to filter cigarettes compared to those who continued to smoke plain cigarettes was 1.6 (P less than 0.05). The overall prevalence of morning phlegm at the end of the follow-up was the same in smokers who changed to filter cigarettes as in persistent plain cigarette smokers. The trends for chronic phlegm were similar, although they did not reach statistical significance. The smokers who stopped smoking had a probability ratio of 0.4 of developing morning phlegm (P less than 0.01) and a ratio of 7.7 for ceasing to produce it (P less than 0.001) compared to the smokers who continued to smoke plain cigarettes. Our results suggest that changing from plain to filter cigarettes is associated with a higher frequency of cessation of phlegm production, but offers no protection against the development of phlegm.

Adult↗
PubMed1990

Pulmonary absorption of instilled and inhaled DTPA in smokers.

Pulmonary absorption of DTPA (diamine-triethylene-penta-acetic acid) has been widely adopted as an index of pulmonary epithelial permeability. The aim of this study was to analyse: (1) if measurements of pulmonary absorption are influenced by the amount of fluid being administered to the lungs together with the DTPA; and (2) if all DTPA administered to the lungs is equally accessible for pulmonary absorption. To this end DTPA was instilled into a lung segment of six smokers in association with a bronchoscopy. In six other subjects (five smokers and one ex-smoker) the DTPA was inhaled as an aerosol. Pulmonary absorption of DTPA was calculated from the plasma DTPA content, as determined for 4-10 h after the administration of the DTPA. We found that the mean transit time for the absorption of instilled DTPA, t(L), across the pulmonary membranes was significantly (P less than 0.05) longer (median 1498 min, range 955-2636 min) than the t(L) of the absorption of the inhaled DTPA (median 131 min, range 44-512 min). Pulmonary clearance of the inhaled aerosolized DTPA tended to be faster when determined by external detection for 4 h, than when estimated from plasma samples, suggesting that not all pulmonary DTPA may be equally accessible for absorption from the pulmonary lining fluids. We conclude that pulmonary absorption of DTPA is influenced by the volume of fluid being administered to the lungs in association with the measurements. Not all pulmonary DTPA, however, is equally accessible for absorption, rendering external detection of pulmonary clearance of DTPA sensitive to a variety of factors other than pulmonary absorption.

Aerosols↗
PubMed1990

Decline of the lung function related to the type of tobacco smoked and inhalation.

Data from a five year follow up study on 4372 smokers and 3753 non-smokers were analysed to investigate the influence of the type of tobacco smoked and whether the subjects said they inhaled or not on the decline in forced expiratory volume in one second (FEV1). The study sample comprised 1492 smokers of plain cigarettes and 1936 smokers of filter cigarettes, 1711 smokers of cheroots or cigars, and 233 male pipe smokers. Over the five years, smokers, especially those who said that they inhaled, had a higher rate of decline of FEV1 than non-smokers, in whom the average decline in FEV1 was 25 ml/year for women and 30 ml/year for men. There was no significant difference in the decline in FEV1 between filter cigarette smokers and plain cigarette smokers. The decline in FEV1 in cigar or cheroot smokers was the highest for all the smoking groups, and associated with a very high tobacco consumption in this group. Among pipe smokers who inhaled, the decline in FEV1 was slightly higher than in the cigarette smokers, whereas non-inhaling pipe smokers had a decline in FEV1 that was similar to that of non-smokers. In general, the smokers who said that they did not inhale had a smaller decline in FEV1 than those who said that they did. The effect of inhalation varied in magnitude in different smoking groups, being most pronounced in pipe smokers.

Female↗
PubMed1990

The constancy of the relation between pressure and flow in the upper urinary tract of the pig.

The long-term constancy of the pressure-flow relationship of the upper urinary tract of the pig was studied in 8 pyeloureteral units and the short-term constancy in 10 units. No constancy was found for neither pelvic baseline pressure nor for pelvic perfusion pressure with an interval of 10 weeks. Pelvic pressure is a very unstable parameter with time but variating within the normal range. Contrarily, a good constancy was found for both baseline and perfusion pressure when 3 consecutive pressure-flow procedures performed with an interval of 30 min were compared to each other. It is concluded that the short-term constancy of the pressure-flow relationship may allow in vivo investigations of the function--if any--of drugs upon the pyeloureter.

Animals↗
PubMed1990

Diabetes mellitus and ventilatory capacity: a five year follow-up study.

During a five year observation period, declines of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were investigated in 200 subjects with diabetes mellitus (DM), 126 subjects who developed DM during that period and 9,051 nondiabetic subjects. After statistical adjustment for age, sex, height, and tobacco consumption we found that the subjects who developed DM during the observation period had the steepest declines of ventilatory function. Their annual declines of FVC (and FEV1) were on average 29 ml (and 25 ml) greater than the declines observed among the nondiabetic subjects. The subjects who had DM during the whole observation period experienced a decline of ventilatory function which was not significantly greater than the decline among the nondiabetic subjects. Our results suggest that DM, at its onset, is associated with a significantly accelerated decline of ventilatory function. If DM has been present for some years, its impact on the decline of ventilatory function is small.

Blood Glucose↗
PubMed1989

Emergence of isolates resistant to ampicillin.

Clinical isolates of Streptococcus faecium demonstrating ampicillin resistance were recovered from eight pediatric patients. Sites of isolation included blood, surgical wound, bile drainage, urine, burns, and peritoneal fluid. Seven patients had prolonged hospitalization, and all had been treated with broad-spectrum antibiotics prior to isolation of the resistant enterococcus. One isolate was from an ill, bacteremic patient; the others were in mixed culture and were not considered causes of disease. The isolates were not epidemiologically related. Minimal inhibitory concentrations for various antibiotics included ampicillin (16 to 32 mg/L), penicillin (128 mg/L), gentamicin (16 mg/L), and vancomycin (2 mg/L). Three isolates demonstrated high-level resistance (greater than 2000 mg/L) to streptomycin; none did so to gentamicin. In vitro synergy testing performed on seven available isolates for ampicillin and gentamicin demonstrated no synergy to this combination. None produced beta-lactamase. Combined antibiogram and plasmid data showed at least five distinct patterns. These strains present a new clinical problem in their high level of resistance to ampicillin and to the combination of ampicillin and gentamicin.

Ampicillin Resistance↗
PubMed1989

Pyeloureteral dynamics. Pelvic pressure and kidney function in partial long-term ureteric obstruction.

In 10 pigs with reno-scintigraphically proven normal upper urinary tracts, a standardized partial obstruction of the left ureter was created at the lower kidney pole level. Three weeks later kidney function was scintigraphically reassessed and the pressure flow relationship in the flow range 0-20 ml/min outlined. The partially obstructed pelvic baseline pressure varied from 9.0 to 32.0 cmH2O. During perfusion small increases in pelvic pressure were seen at all flow rates in the individual cases and there was a linear relationship between pressure and flow. Compared to previous results of a similar but acute obstruction the results were identical in pressure ranges and pressure flow profile. This demonstrates, that a longitudinal stability in transport mechanism qualities is present also during the course of obstruction. The pelvic pressure at low flow rates was significantly correlated to kidney function depression, whereas perfusion pressures at high flow rates did not show any correlation, except at 20 ml/min. This clearly indicates, that the pelvic pressure at normal urine flow rate is an important factor in the pathogenesis of obstructive nephropathy.

Animals↗
PubMed1989

Determinants of chronic mucus hypersecretion in a general population with special reference to the type of tobacco smoked.

Data from a prospective study of 3884 smokers and 3676 non-smokers followed for five years were analysed to investigate the determinants of chronic mucus hypersecretion (CMH). During the follow-up 414 (10.7%) smokers and 140 (3.8%) non-smokers developed CMH. The influence of the type of tobacco smoked (plain cigarettes, filter cigarettes, pipe and cheroots/cigars), lifetime tobacco consumption, age, alcohol consumption, and socioeconomic status on the development of CMH was assessed in men and women separately using multiple logistic regression. In smokers of both sexes, the risk of developing CMH increased significantly with lifetime tobacco consumption and almost significantly with age. In male smokers, the risk of developing CMH increased with alcohol consumption but was not significantly related to the type of tobacco smoked. In female smokers, the risk of CMH increased significantly with short school education and was, after adjustment for the amount of tobacco smoked, approximately twice as high in cigarette smokers as in cheroot smokers. However, as female cheroot smokers on the average consumed much more tobacco than female cigarette smokers the incidence of CMH was almost the same in the two groups. Among current non-smokers, the risk of developing CMH increased with age and previous tobacco consumption. It is concluded that although a number of factors are associated with the development of CMH, tobacco smoking, regardless of the type of tobacco, is a major determinant of CMH.

Adult↗