Biomedical subjects
Publications and source records attributed to J Mortensen.
Three different tests are now widely used in evaluating hydronephrosis, a renal pelvic puncture with perfusion test, the furosemide urography and the furosemide renography. A case is reported in which the different tests result in different diagnosis concerning the degree of pyelourethral obstruction.
The upper urinary tract of the pig was subjected to acute standardized obstructions, size 10-F, 8-F and 6-F, in both the proximal and the distal part of the ureter. Each obstruction was followed by measurements of the renal pelvic pressure-flow relationship between 0 and 20 ml/ureter/min. The study showed that the mean baseline pressure in the renal pelvis changed due to the obstruction with an increase related to the degree of obstruction. When the flow was increased a pressure-flow relationship in essence similar to the normal pressure-flow relationship was revealed. Thus phase 1, which is the pressure-flow relationship at low flow rate with urine flowing into a relaxed ureter, was practically eliminated and phase 2 was shifted to the left. The linear pressure-flow relationship in phase 3 was preserved but there was tendency for higher increments with increasing degree of obstruction. Even in cases of severe obstruction both baseline measurements and perfusion pressure measurements showed results well within the normal accepted limits of renal pelvic pressure. It was furthermore shown that the overlap was smallest at the low flow rates between 0 and 2 ml/ureter/min. All degrees of distal obstruction had a lower pressure at flow rates below 10 ml/ureter/min than proximal obstruction, a pressure difference which could be attributed to the peristaltic activity of the ureter.(ABSTRACT TRUNCATED AT 250 WORDS)
In a study of the dynamic function of the urinary tract in infravesically obstructed pigs with vesicoureteric reflux, 5 pigs with 6 refluxing ureters evidenced urinary tract infection after 8 and 10 weeks of obstruction. Examination showed that the median ureteric baseline activity had decreased to 0.0 A.P./min (action potentials/min). During bladder filling, no increase in activity was seen, although there was pressure equilibration between the bladder and the renal pelvis, when the reflux producing bladder pressure was reached. Only a few episodes of retrograde activity were recorded during the bladder filling. 46% of the ureteric contractions were incomplete and stopped in the mid-third of ureter. The study showed the severe, irreversible impairment of ureteric function when subjected to not only reflux and obstruction but also infection.
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In a long-term multicenter open randomized study of 103 patients with glaucoma or intraocular hypertension, oral propranolol combined with 2% pilocarpine was compared with 0.5% topical timolol also combined with 2% pilocarpine, with respect to the effects on intraocular pressure and other signs of glaucoma. The results showed that the hypotensive effects were highly significant and equal for both treatments. There were no significant differences between the 2 groups in the amount of cupping of the nerve head or the visual field defects developing during treatment. An additive hypotensive effect was recorded when both propranolol and timolol were combined with pilocarpine, which indicates the development of tolerance to both beta-blockers. Pulse rate and blood pressure were moderately reduced in both groups, both significantly more so in the propranolol group. The investigation indicates that when combined with pilocarpine the 2 adrenergic beta-receptor blockers are equally effective. We believe that oral propranolol can improve drug compliance in the treatment of glaucoma.
In 10 female pigs, the proximal part of the left ureter was obstructed for 10 weeks by implantation of the ureter into the psoas muscle. After 9 weeks of obstruction, 6 systems showed delayed or impaired drainage at renographic examination. Renal function was slightly impaired in 1 case. At operation, 4 systems were macroscopically normal while the rest showed slight to moderate dilatation. The intrapelvic resting pressure was normal in 8 of 9 cases. At perfusion, all systems responded within the normal limits at 8 cm3/min while high-pressure responses were found in 4 units above 8 cm3/min. No correlation was found between the resting pressure and the pressure response and the degree of dilatation or impairment of renal function.
The relationship between pressure and flow of the multicalyceal renal pelvis of the pig was investigated in 10 units. The relationship was studied in the intact system and after three consecutive transsections of the ureter 3 cm proximal to the ureterovesical junction, at the lower pole of the kidney and as proximal on the renal pelvis as possible. The mean resting renal pelvic pressure changed from 7.3 to 8.8 cm H2O when a distal transsection was performed. The resting pressure after proximal transsection and pelvic transsection was 8.0 and 6.5 cm H2O respectively. During perfusion the intact system as well as the distal transsection showed a three-phased relationship. In the latter the phases showed a shift to the right and the renal pelvic pressure was significantly decreased at flow rates from 4-10 ml/ureter/min. Perfusion after proximal transsection and pelvic transsection caused only minor increases in the renal pelvic pressure approximating a linear relationship. The study confirms a three-phased relationship between pressure and flow in renal pelvis and a resistance to high flow rates depending on the length of the ureter.
In a cystometrographic study in 36 young pigs the importance of ageing, of the submucosal part of ureter, and of infravesical obstruction in the vesico-ureteral reflux pathogenesis was investigated. Spontaneous vesico-ureteral reflux was found in 13 of the pigs (23 ureters). As the pigs grew older, the reflux disappeared, but if an infravesical obstruction was superimposed the reflux was maintained in half of the pigs. When the intravesical submucosal ureter was unroofed, vesico-ureteral reflux was present 10 weeks later in half of the cases. If an infravesical obstruction was superimposed all the pigs had sustained reflux 10 weeks later. The reflux producing bladder pressures decreased after induction of an infravesical obstruction. This suggests irreversible damage to the valve function due to the obstruction. In conclusion, the present study confirms ageing and the valve function as important factors preventing reflux. Additionally, it stresses the importance of normal bladder urethral function in preventing reflux.
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The renal pelvic pressure/volume relationship was investigated in 8 pigs with a 10-week total unilateral obstruction. The pressure in the totally obstructed pelves was significantly increased to a mean value of 44 cm H2O (30.5-64). After emptying, the renal pelves were refilled continuously at a rate of 8 cc per minute to a maximal pressure of 80 cm H2O. The relationship between pressure and volume showed a cystometric configuration. Capacity at the maximal pressure varied from 32 to 167 ml. The difference in capacity was not related to differences in the pelvic wall connective tissue fraction or the wall thickness. Neither was any relation between resting pressure and capacity found. The investigation demonstrates that total supposedly uniform obstructions exhibit a broad variation in compliance. The broad variation in compliance might be an important factor in the pathogenesis of progression in hydronephrosis.
The peristaltic activity of the upper urinary tract was investigated by means of a simple videodensitometric system. Through a transparenchymally placed catheter contrast medium was infused into the renal pelvis with perfusion rates increasing from 1 to 15 ml/min. Sequences of 3-5 min were recorded by means of a Siemens image amplifier on videotape for later analysis. Photodiodes were placed on the screen over the calyces, renal pelvis and ureter at a distance of 5 cm. An amplifying system and a UV recorder were used for registration. Peristaltic frequency, transmission velocity and average bolus volume were measurable in 8 out of 10 pyeloureteral units. Additionally, calyceal activity was detectable in one case. The tracings obtained by videodensitometry were reproducible and easy to analyse. Conversion of videorecordings to analogue signals for analysis might be a possible future clinical diagnostic method.
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The renal pelvis pressure flow relationship of 40 normal pig upper urinary tract was investigated. During standardized studies it was disclosed that the resting pressure has a normal distribution with wide 95% confidence limits (0.3-14.7 cmH2O). When perfusion was introduced, pelvic pressure increased, the normal distribution was lost, and the 95% confidence limits were broadened to more than 30 cmH2O. A normal distribution was regained at higher flow rates. The mean increment beyond 8 ml/minute was small, only 3.7 cmH2O from 8 ml/minute to 20 ml/minute. The wide variation found in pressure responses to high flow rates and the spread of pressures at higher flow rates imply major difficulties in distinguishing, between normal and abnormal pressure flow relationships in renal pelvis.
The pressure-flow relationship of the normal pyeloureter was investigated in 10 pigs. From a mean baseline pressure in the pelvis of 7.5 cm H2O, the pressure increased during perfusion. The pressure increase from baseline to 8 ml/min was significant. It was noticeable that a perfusion rate of 8 ml/min resulted in intrapelvic pressures of more than 27 cm H2O in 4 of the 10 pigs. A further increase in perfusion rate gave only a slight, additional increase in pressure with linear relationship between flow rate and pressure. The steep rise in pressure from baseline values of 8 ml/min and the slight additional increase in pressure hereafter was probably caused by a transformation of peristalsis to a continuous flow.
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In two patients with cryptorchism orchidectomy was performed because of testicular atrophy and torsion respectively. From the macroscopic appearance malignancy was not expected in either of the cases, but histological examination showed invasive carcinoma. This indicates that biopsies should be taken whenever operations are performed on cryptorchid testes, and it may be of importance to biopt all cryptorchid testes at a certain age.
In an 81-year-old woman acute colonic pseudo-obstruction occurred 3 days after operation for right femoral neck fracture. When conservative treatment failed, ultrasonographically guided percutaneous drainage of the caecum was performed to relieve progressive caecal dilatation. Bowel function was thereafter restored. The method may be a therapeutic option for acute colonic pseudo-obstruction in selected cases.
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