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Biomedical subjects

J Mortensen

Publications and source records attributed to J Mortensen.

At least 109 records · Page 6Linked to original sources
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

Pelvic pressure measurements in the totally obstructed pyeloureter of the pig in 4 weeks.

The pelvic pressure was measured with a noninvasive technique in 7 pigs with a total unilateral obstruction of the ureter lasting 4 weeks. Pressure measurements were performed once a week. Although there was a wide pressure variation both intra- and interindividually during the 4 weeks, all systems had an elevated pressure (greater than 25 cm H2O) after 4 weeks. This study shows that the pelvic pressure can remain elevated in the chronically totally obstructed pyeloureter.

Animals↗
PubMed1988

Preoperative symptomatology and diagnostic findings in relation to outcome of pyeloplasty in patients with primary hydronephrosis.

Sixty-seven patients, aged 3-71 years, with primary hydronephrosis were operated at our department during a 5-year period. All patients had Anderson-Hynes pyeloplasty. The primary clinical result of surgery was excellent in 63 patients (94%). Of the patients with reduced renographic uptake fraction preoperatively, 38% had a significant gain 6 months after reconstruction, while only 1 patient had a reduction. There was no correlation between the outcome of reconstruction and preoperative history, degree of hydronephrosis on IVP, preoperative functional share on renography or the peroperative finding of aberrant vessels compressing the ureter. It was concluded that surgery should be undertaken on rather wide indications as reconstruction leads to stable or improved renal function regardless of preoperative symptoms or diagnostic findings.

Adolescent↗
PubMed1988

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↗
PubMed1987

Dynamics of the upper urinary tract: II. The effect of variations of peristaltic frequency and bladder pressure on pyeloureteral pressure/flow relations.

The dynamics of pyeloureteral flow is described when there is no peristalsis and for peristalsis of high and intermediate frequencies, on the assumption that the ureter is uniform except in the mid-ureter and at the outlet. The possibility of upstream transmission of bladder pressure variations to the renal pelvis is considered. The overall behaviour depends on three principal variables, the maximum tube pressure in the contraction waves, the intrinsic peristaltic carrying capacity and the peristaltic frequency f, expressed in the form fT where T is the time for a peristaltic contraction wave to sweep through the ureter. At intermediate peristaltic frequencies (fT less than but comparable with one) oscillatory flow patterns can occur, in which periods of peristaltically driven flow alternate with extraperistaltic periods of flow through the open ureter. The kidney is better isolated from bladder pressure variations when the peristaltic frequency is high, but high peristaltic frequency can by itself lead to elevated renal pelvic pressure if the flow rate is high. Experimental observations in pigs are presented to support these conclusions.

Animals↗
PubMed1986

Proximal tubular atrophy: qualitative and quantitative structural changes in chronic obstructive nephropathy in the pig.

Kidneys of pigs with various degrees of induced chronic obstructive nephropathy were studied by light- and electron microscopy to assess the structural changes of proximal convoluted tubules with increasing degrees of atrophy. A particular aim was to evaluate the quantitative relationship between proximal tubular and interstitial changes in early tubular atrophy. The kidneys were subjected to varying degrees of ureteral obstruction and were fixed by in vivo vascular perfusion. Quantitative (morphometric) analyses were carried out on montages of electron micrographs representing randomly selected cortical areas and cross sections of individual proximal convoluted tubules. The results demonstrated that ureteral obstruction was followed by significant reductions in proximal tubular epithelium, in volume of proximal tubular mitochondria and in surface area of proximal tubular basolateral membranes. These changes were present even in the absence of any demonstrable increase in cortical interstitium or alterations in the relationships between proximal tubules and peritubular capillaries. With increase in the volume of cortical interstitium the proximal tubules were further simplified in ultrastructure with a reduced number of interdigitating lateral cell processes. Concomitantly there were significant quantitative changes in the spatial associations between tubules and capillaries due to increase in tubulo-capillary distances. The present study shows that ultrastructural changes in proximal tubules during early atrophy precede the volume increase in cortical interstitium associated with chronic obstructive nephropathy. It is suggested that the early tubular changes are due to decreased functional loads, whereas the further progression of tubular atrophy may be a result of impaired nourishment of the tubular cells due to increased interstitial tissue and altered relationships between tubules and capillaries.

Animals↗
PubMed1986

The pressure-volume relationship of the pig renal pelvis.

In five pigs weighing approximately 85 kg. the pelvic pressure-volume relationship was investigated. Through a catheter introduced into the renal pelvis from the ureter with ligation at the ureteropelvic junction, a continuous filling of one ml./minute was established. After drainage of the pelvis filling was begun showing an exponential relationship between pressure and volume. Fillings in all of the units confined the equation y = a + bx + cx2. Emptying showed unanimously clockwise hysteresis although 1/3 of the fillings revealed active contractile forces with an inverted S-shaped emptying curve. The normal multicalyceal renal pelvis in pigs of the same size showed a wide range of pressure-volume relationships both between individuals and between the two investigations. This wide range might be of importance in the development of dilatations due to obstruction.

Animals↗
PubMed1986

Tuberculosis in a developed country.

All 515 patients notified for tuberculosis for the first time in 1972, 1977 and 1982 in Copenhagen have been studied. Changes during the period and differences between Danes and immigrants were looked for. The percentage of immigrants increased during the period. The immigrants had a different age distribution, higher frequency of extrapulmonary tuberculosis with a distribution different from that of Danes, fewer complicating diseases and they drank less alcohol. No significant changes in the patient population took place in the decade studied, except for a decreasing number of Danes with tuberculosis, a decreasing number of abacillary patients and an increase in the percentage of extrapulmonary tuberculosis. At follow-up in 1983, none of the immigrants, but 147 of 407 Danes had died, mainly from complicating diseases. Life expectancy for the Danes, who survived the initial phase, was not significantly different from that for the population at large. None of the patients were bacillary at the time of the follow-up.

Adult↗
PubMed1986

Renal pelvic peristalsis in pigs during standardized flow rate variations.

In the multicalyceal kidney of the pig renal pelvic pressure waves were investigated in 15 units. The pelvis was perfused with bodywarm saline gradually increased from 0-20 ml/min. The study showed a predominantly unimodal activity but all systems showed periods of instability which were characterized by coupled pressure waves, high frequencies and cascade emptying. The amplitude of the pressure waves increased with increasing flow and the study showed correlation between low amplitude and high frequency and vice versa.

Animals↗
PubMed1985

Peristaltic activity in the normal renal pelvis of the pig during standardized perfusions.

The peristaltic activity in 36 normal pig pyeloureters in 19 pigs was investigated during various steady flow rates. Flow rates of 2, 4, 6, 8, 10 and 20 ml/ureter/min resulted in a mean frequency of 4.5, 4.9, 4.4, 4.2, 4.2 and 5.1 peristaltic events/min respectively. The frequency of peristalsis was thus independent of flow rate and also of baseline pressure but showed a weak relation to the magnitude of the mean perfusion pressure. The peristaltic activity is generally constant at all physiological flow rates in the steady state. This standardized study therefore confirms previous observations in showing that urine transport mainly is regulated by changes in the bolus size.

Animals↗
PubMed1985

Hydrodynamics of the normal multicalyceal pyeloureter in pigs: the pelvic pressure response to increasing flow rates, its normal ranges and intraindividual variations.

In 39 normal pig pyeloureters, pelvic pressure was measured at the following perfusion rates: 0, 2, 4, 6, 8, 10 and 20 ml./min. The mean pelvic pressure increased from 7.09 to 21.53 cm. H2O. This increase showed 4 different phases. The first was a low pressure phase between 0 to 2 ml./min. where transport took place by peristalsis. The second was a high pressure phase between 2 and 4 ml./min. where the peristalsis opposed the passive interperistaltic filling of ureter. In the third phase, between 4 and 6 ml./min., a decreasing pressure increment was seen, probably caused by leakage through the contraction ring. In the fourth phase, between 6 and 20 ml./min., the pressure was proportional to the flow rate and ureter functioned hydrodynamically as a tube. The measurements were performed bilaterally in 19 animals. Fourteen animals showed a difference either in baseline pressure or in mean perfusion pressure between the 2 sides; in effect, no coherence in pressure exists between the pyeloureters in the individual pig. Ninety-five per cent confidence limits of the pelvic pressure were calculated at the different flow rates. The limits of the baseline pressure were 1.43 and 12.75 cm. H2O, respectively. During perfusion the upper limit of normal pressures increased markedly in the flow range 0 to 4 ml./min. being 25.46 cm. H2O at 4 ml./min. A further increase in flow rate caused only a modest increase in the upper limit. It is concluded that a comprehensive study of the pressure flow relationship provides new information concerning fluid transport in the upper urinary tract.

Anesthesia, General↗
PubMed1985

Effect of postoperative extradural morphine on lower urinary tract function.

The effect of postoperative extradurally administered morphine on lower urinary tract function was studied in female patients undergoing uterine surgery. Urodynamic measurements were made on the day before and on the day after the operation, using a DISA 2-channel carbon dioxide (CO2) cystomictrograph. In ten patients without postoperative urinary retention no changes in cystometry were found during morphine administration, while two patients who developed acute urinary retention had a marked increase in bladder capacity and of detrusor pressure. In contrast, the urethral pressure profile was unchanged in both groups of patients. Intravenously administered naloxone tended to normalize the bladder capacity in the patients with urinary retention. These findings seem to indicate a marked effect in some patients of extradurally administered morphine and the acute urinary retention, following morphine administration, may be treated with naloxone.

Adult↗