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Biomedical subjects

J Mortensen

Publications and source records attributed to J Mortensen.

At least 91 records · Page 5Linked to original sources
PubMed1989

Chronic obstructive lung disease in Copenhagen: cross-sectional epidemiological aspects.

We analysed data from the Copenhagen City Heart Study to study the prevalence, possible risk factors for, and inter-relations between bronchial hypersecretion (BH) and chronic airflow limitation. The study sample consisted of 12,698 subjects between 20 years and 90 years of age, randomly selected from the population of the city of Copenhagen. The age-adjusted overall prevalence of BH in the population of Copenhagen was estimated to be 10.1%; 12.5% in men and 8.2% in women. The overall prevalence of clinically relevant chronic airflow limitation (forced expiratory volume in 1 s less than 60% of that predicted) was 3.7% and not significantly different between sexes. Both airflow limitation and BH increased with age, smoking, alcohol consumption, short education, and low income. However, the association of airflow limitation with alcohol consumption, education and income was much weaker than the association with smoking. Regardless of smoking habits, the majority of subjects with airflow limitation did not report symptoms of bronchial hypersecretion.

Adult↗
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

Specific serum immunoglobulin D, detected by antibody capture enzyme-linked immunosorbent assay (ELISA), in cytomegalovirus infection.

An antibody capture enzyme-linked immunosorbent assay (ELISA) was developed for the detection of immunoglobulin D (IgD) antibodies to cytomegalovirus (CMV) in sera from blood donors and various groups of patients infected with CMV. This method has previously been found especially valuable in detecting specific antibodies of the IgM, IgE, IgA and IgG class in patients with CMV infection. Specific CMV IgD antibodies were found in 37% of CMV seropositive blood donors and in 47 (88%) of the 53 patients investigated, including bone marrow transplant and renal allograft transplant patients, patients with CMV mononucleosis, neonates with CMV infection and AIDS patients with CMV infection. The highest IgD reactivity was found in patients having either a primary post-transplant CMV infection or CMV mononucleosis. The IgD reactivity in patients with AIDS and in neonates was low. It was also found that in the acute phase of CMV infection the development of CMV antibodies of the IgD class was similar to the development of antibodies of the other classes. The maintenance of IgD activity in some patients together with the presence of CMV IgD antibodies in a great proportion of the blood donors indicates that the development of CMV IgD antibodies resembles that of the IgG class. Determination of specific IgD antibodies offered no advantage over determination of specific antibodies of the IgM, IgE and IgA classes in the diagnosis of CMV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Childhood tuberculosis in a developed country.

From 1975 to 1985, 25 Danish children (aged less than 15 yrs) and 40 children of immigrants were notified for tuberculosis in Copenhagen for the first time. A follow-up was undertaken in 1987. The annual rate of tuberculosis per 100,000 among the Danish children was 5 and among immigrant children 68-200 depending on the nationality. At the time of diagnosis, no significant differences were present between Danes and immigrants as regards age, sex, occurrence of symptoms or previous BCG immunization, whereas there were significantly more bacteriologically proven cases among the immigrants. All Danish children had respiratory tuberculosis only, whereas 13 immigrant children had extrapulmonary manifestations including one case of miliary and two cases of meningeal tuberculosis. At follow-up, all patients were cured for tuberculosis and had experienced a normal physical development.

Child↗
PubMed1989

Reproducibility of iodine-123-hippuran renoscintigraphy in the normal pig at various flow rates.

Twenty-two pigs with normal kidney function and upper urinary tracts were examined with renoscintigraphies once a week for 4 weeks. In order to study the influence of urine flow on the reproducibility, renoscintigraphies were undertaken during various urinary flow rates. Renal split function was reproducible at any level of and independent of the urinary flow rates. For parenchymal and pelvic mean transit times a normogram was constructed for selected urinary flow intervals. An inverse relationship to urine production was seen. Parenchymal and pelvic transit times were fully reproducible when data were compared in two or three consecutive examinations of the same kidney at the same urinary flow rate. Both parenchymal and pelvic mean transit times were however significantly different (p less than 0.001) in kidneys studied from one urinary flow rate to another. Single kidney hippuran clearance was fully reproducible when compared in the same urinary flow interval. However a significant difference was found (p less than 0.05) when single kidney hippuran clearance was compared in renographies undertaken at different urinary flow intervals. Furthermore the study suggests that the size of hippuran clearance is dependent on the urine production, since an increase in hippuran clearance was seen in relation to increase in urinary flow. In conclusion this pig study showed, that monitoring of the urinary flow rate is extremely important in this very commonly used clinical investigation, and that the investigation should be performed in the same state of hydration at any renography to obtain reproducible results.

Animals↗
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

Long term sequelae after talc pleurodesis for spontaneous pneumothorax.

After talc pleurodesis performed between 1954 and 1964 because of spontaneous pneumothorax during thoracoscopy, 99 patients were followed up. Only 2 patients experienced a pneumothorax relapse. Mesothelioma was not observed in any case, X-ray changes in the Pleura were moderate, and lung function did not show any significant restriction. It is concluded therefrom that the method is effective and does also not produce any noticeable side effects on long-term observation.

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

Renal blood flow and pelvic pressure after 4 weeks of total upper urinary tract obstruction in the pig. The effect of a TxA2 synthetase inhibitor on active preglomerular vasoconstriction.

In 8 female pigs complete unilateral ureteral obstruction was investigated over a 4 weeks period. The pigs were monitored with intrapelvic pressure measurements and by 131-I-hippuran scintigraphy twice a week; one group without and one with TxA2 blocking, UK-38,485 [3-(1H-imidazol-1-yl-methyl)-2-methyl-1H-indol-1-propanoic acid], which is a well-known selective thromboxane synthetase inhibitor. During the course of obstruction there was an ipsilateral linear reduction of split function to background level and a net reduction in total hippuran clearance in both groups. On the obstructed side there was a linear reduction of hippuran clearance from 116 +/- 26 ml/min to 11 +/- 3 ml/min during the first 2 weeks of obstruction. The TxA2 synthetase inhibitor, 5 mg/kg reduced se-TxB2 to almost zero for at least one hour after i.v. administration. One week after obstruction the pelvic pressure was 45 +/- 5 cm H2O) administration of the TxA2 synthetase inhibitor. The pelvic pressure remained elevated throughout the period of observation. The study confirmed earlier work which showed that total ureteral obstruction caused complete cessation of kidney function within a few weeks, but contradicts previous studies because there was no increase in renal blood flow after thromboxane blockade. These differences may be explained by several mechanisms. The continuing increase in pelvic pressure suggested that it was not only a preglomerular vasoconstriction which was responsible for the renal flow reduction, but that there was also a postglomerular vasoconstriction.

Animals↗
PubMed1988

The influence of pyeloureteral peristalsis on pelvic pressure during increase in flow rate.

Thirty-nine normal pig pyeloureters were perfused with 0, 2, 4, 6, 8, 10 and 20 ml/min during continuous measurement of the pelvic pressure. A phasic pressure response was identified with the highest pressure increase between 2 and 4 ml/min. Two groups were analyzed. One consisting of the 10 pyeloureters with the highest pressure increase and the other of the 10 pyeloureters with the lowest pressure increase to a perfusion rate of 4 ml/min. The peristaltic frequency was significantly higher (about 6/min) in the high pressure group than in the low pressure group (about 3.5/min). It is concluded that a high peristaltic frequency is at least partly responsible for the high pressure response to increasing flow because the peristaltic contraction ring opposes the filling flow through ureter.

Animals↗
PubMed1988

Pelviometry in the normal and the partially obstructed porcine kidney: recordings before and three weeks after application of ureteral obstruction.

In 11 pigs a standardized proximal ureteric obstruction was applied. The effect of the obstruction was examined three weeks later. In both the normal and the obstructed systems the pressure-volume relationship was exponential. Mean pelvic capacity increased from 6.5 ml. to 44.1 ml. (p less than 0.002). Mean intrapelvic baseline pressure increased from 10.0 to 16.8 cm. H2O (p less than 0.02), and this parameter correlated positively to volume (rS = 0.79 - p less than 0.05). There was a slight decrease in the relative function of the obstructed kidney on renography (from 49% to 39% of the total renal function), but this was not significant. The decrease in function was correlated to the increase in capacity (rS = -0.69 - p less than 0.05). In this series renal deterioration occurred in the hydronephrotic kidneys, and at least in this model of acute ureteral obstruction there was no support for the theory that hydronephrotic transformation is a compensatory mechanism which protects the kidney when the upper urinary tract is obstructed.

Animals↗