Possible autocrine loop of the epidermal growth factor system in patients with benign prostatic hyperplasia treated with finasteride: a placebo-controlled randomized study

OBJECTIVE

To analyse the expression of the epidermal growth factor (EGF) system in prostate tissue and secretions obtained from patients with benign prostatic hyperplasia (BPH) treated with or without finasteride (which primarily targets the androgen-sensitive secretory epithelial cells in the prostate, with little effect on basal epithelial and stromal cells).

PATIENTS AND METHODS

The expression of the EGF system was evaluated by enzyme-linked immunosorbent assay and immunohistochemistry in samples of prostate tissue and secretions from patients with BPH randomized for treatment with finasteride or placebo for 3 months before surgery.

RESULTS

Prostate tissue expressed the EGF receptor (HER1) and HER2, and the ligands EGF, transforming growth factor alpha (TGFalpha), heparin-binding (HB) EGF, betacellulin and amphiregulin. Treatment with finasteride produced greater concentrations of amphiregulin (P < 0.05) than did placebo, did not change the level of TGFalpha, HER1 and HER2, and tended to decrease the concentration of EGF, betacellulin and HB-EGF in prostate tissue. Using immunohistochemistry, HER1 and TGFalpha were both localized to the basal epithelial cells, and there was a strong positive correlation among the tissue concentrations of HER1, HER2 and TGFalpha. Amphiregulin localized to the luminal secretory epithelium. Prostate secretions contained only EGF, which was at levels approximately 150 times higher than in prostate tissue; treatment with finasteride did not affect the concentration of EGF in prostate secretion.

CONCLUSIONS

There were only minor changes in the expression of TGFalpha, HER1 and HER2 after finasteride treatment. This may represent an important system for the continuous growth and homeostasis of the androgen-independent basal epithelial cells in the prostate.

Resistive index: an experimental study of the effects of diuretic stimulation in the unobstructed porcine kidney

OBJECTIVE

To study the effects of diuretic stimulation with frusemide and mannitol on the renal resistive index (RI) of the undilated unobstructed porcine kidney.

MATERIALS AND METHODS

Experiments were carried out on 14 pigs divided into two equal groups (A and B), under general anaesthesia. In all pigs both ureters were catheterized, thereby allowing urine output to be measured on each side separately, and an indwelling catheter in a femoral artery used to continuously measure the systemic blood pressure. Furthermore, in five pigs from each group, right renal blood flow was measured by ultrasonic flow probes placed around the renal arteries. The right kidney RI was measured at baseline and at 5-min intervals after frusemide (group A) and mannitol (group B) stimulation, for 75 min.

RESULTS

Frusemide caused significant increases in diuresis (P < 0.001) and renal blood flow (P = 0.009). This was accompanied by a significant decrease in mean arterial pressure (P < 0.001). The RI was unaffected (P = 0.706), with mean values in group A of 0.58-0.65. Mannitol also caused a significant increase in diuresis (P < 0.001) and a subtle but significant decrease in mean arterial pressure (P < 0.001). However, renal blood flow was unaffected by the diuretic (P = 0.820); the mean RI values were unaffected, at 0.61-0.66 (P = 0.375).

CONCLUSIONS

These results show that diuretic stimulation with frusemide or mannitol does not affect the RI of the unobstructed undilated porcine kidney, despite significant changes in diuresis, renal blood flow and mean arterial pressure.

Reduced number of glomeruli in kidneys with neonatally induced partial ureteropelvic obstruction in pigs

PURPOSE

We quantify the structural components of the nephron in adult pig kidneys with neonatally induced unilateral hydronephrosis in comparison with nonobstructed kidneys.

MATERIALS AND METHODS

The study included 11 pigs with unilateral partial ureteropelvic obstruction induced 2 days after birth and 8 sham operated control pigs. Obstructed kidney glomerular filtration rate was significantly reduced at age 4 weeks but did not differ from control kidneys after 24 weeks. At age 24 weeks the kidneys were perfusion fixed, and the number and volume of glomeruli and tubular lengths were measured using stereological methods.

RESULTS

Mean obstructed kidney volume did not differ from that of control kidneys. Mean number plus or minus standard deviation of glomeruli in the obstructed kidneys was reduced by 28% compared to that of control kidneys (502 +/- 163 x 103 versus 697 +/- 161 x 103, p = 0.02), whereas no difference in mean glomerular volume was observed. Mean length of the proximal or distal tubules did not differ between obstructed and control kidneys. Mean number or volume of glomeruli in nonobstructed kidneys contralateral to obstructed kidneys did not differ from that of control kidneys. The individual number of glomeruli in the obstructed kidneys was not associated with function of these kidneys.

CONCLUSIONS

Neonatally induced unilateral partial ureteropelvic obstruction causes impaired nephrogenesis with a significant reduction in the number of nephrons, which is not reflected in measurements of kidney function in this model. The reduction in the number of glomeruli suggests that congenital unilateral obstruction impairs nephrogenesis.

Distension-induced duodenal contractions vary with the phases of the canine interdigestive migrating motility complex

BACKGROUND

The aim of the study was to evaluate whether the sensitivity for distension-induced contractions in the duodenum varied with the phases of the interdigestive migrating motility complex (MMC).

METHODS

Four beagles (12-17 kg) with gastric fistulas were studied by means of perfused low-compliance manometry. A 2.5-cm-long balloon was placed in the third part of the duodenum. Side holes for pressure measurements were placed inside the balloon, 2cm proximal to the balloon, and in the antrum. Two-minute distensions with balloon pressures of 10 cmH2O were repeated in 10-min intervals during 17 MMCs. Twelve MMCs were also recorded without doing distensions.

RESULTS

Balloon distension did not affect the duration of phase III and the MMC. In the beginning of phase I, distension did not significantly affect duodenal motility whereas distension induced contractile responses in late phase I, early phase II and late phase II (p < 0.05). The highest increase from the pre-distension to distension period was observed in early phase II (average 4 contractions min(-1)). However, considering the level of pre-distension contraction frequency, the fractional increase was by far the highest in late phase I. In phase III no difference was found between the periods before and during distension (15.8 +/- 0.7 versus 15.8 +/- 0.5 contractions min(-1)). The effect of balloon distension in phase IV was difficult to evaluate due to the inconsistent nature and sometimes rapidly decreasing activity in phase IV. Duodenal distension did not change frequency and amplitude of antral phase II contractions (p > 0.5).

CONCLUSIONS

Duodenal balloon distension elicited ascending contractions in the canine duodenum in late phase I and in phase II. A refractory phase was demonstrated in the beginning of phase I while in phase III the frequency of contraction could not be increased further.

Intra-individual variability in nighttime urine production and functional bladder capacity estimated by home recordings in patients with nocturnal enuresis

PURPOSE

We evaluated the intra-individual variability and reproducibility of nighttime urine production on wet nights and functional bladder capacity estimated by long-term home recordings of monosymptomatic nocturnal enuresis. In particular, the intention was to evaluate the validity of 1 versus 2 weeks of recording when estimating urine volume on wet nights and 1 versus 2 weekends of recording when estimating functional bladder capacity.

MATERIALS AND METHODS

We analyzed 120, 2-week home recordings of nighttime urine volume from patients with monosymptomatic nocturnal enuresis 6 to 16 years old (mean age 9.1) with at least 3 wet nights per week. Most patients were nonresponders or partial responders to desmopressin. Nighttime urine volume was estimated by weighing diapers before and after sleep, and measuring morning urine volume. Of the home recordings 62 included frequency volume charts for 2 weekends, which were evaluated for functional bladder capacity defined as the largest voided volume observed.

RESULTS

No significant overall week-to-week differences were observed in average urine volume on wet nights and functional bladder capacity. There was a large intra-individual variability in all measured variables, which was most pronounced for functional bladder capacity and least pronounced for urine volume on wet nights. With regard to repeatability, the limits of agreement of urine volume on wet nights were -32% and 36% (95% confidence interval) as opposed to -54% and 48% for functional bladder capacity.

CONCLUSIONS

In this study intra-individual week-to-week estimates of average urine volume on wet nights demonstrated acceptable variability and repeatability in contrast to functional bladder capacity. A reliable estimate of urine volume on wet nights could be obtained by 7 nights of home recording, whereas 4 days of daytime recording were necessary when estimating functional bladder capacity. Similar studies of patients who respond to desmopressin are needed.

No relationship between family history of enuresis and response to desmopressin

PURPOSE

We determined the prevalence of positive family history of nocturnal enuresis in relation to response to desmopressin.

MATERIALS AND METHODS

A total of 328 children with nocturnal enuresis and 53 normal children were interviewed to determine the presence of family history of nocturnal enuresis. Response to desmopressin was confirmed in some cases by home recordings of enuresis episodes during 2 baseline weeks and 2 weeks of 20 to 40 microg. desmopressin intranasally.

RESULTS

Significantly more patients than normal children (75% versus 38%, p <0.001) reported a positive family history of enuresis (any relative). The high prevalence of a positive family history of nocturnal enuresis was present in severe/nonsevere or primary/secondary types of enuresis. Of the patients 141 completed 4 weeks of home recordings including 20 with a complete response (greater than 90% reduction in wet nights week), 25 with a partial response (50% to 90% reduction) and 96 with no response (less than 50% reduction). The prevalence of a positive family history (any relative) was no different among the response groups (80%, 84% and 78%, respectively). Similarly, family history, as defined by first order relatives only, showed no relation to treatment response.

CONCLUSIONS

A positive family history of nocturnal enuresis is more prevalent in patients with enuresis than in normal children regardless of the nature of the nocturnal enuresis. In contrast to previous reports, a positive family history failed to predict a good response to desmopressin treatment. Hereditary factors are important to consider in desmopressin responding and desmopressin resistant cases.

Partial unilateral ureteropelvic junction obstruction induced in 2-week-old piglets

PURPOSE

We examined effects on kidney function and morphology of a partial ureteropelvic junction obstruction induced late in the postnatal nephrogenesis period of the pig. We compared the results to a similar study on pigs with obstruction induced early in the nephrogenesis period.

MATERIALS AND METHODS

A total of 20 14-day-old pigs were included in the study. Fifteen animals were randomized to partial unilateral obstruction and 5 were sham operated. Kidney function and morphology were analyzed regarding glomerular filtration rate, renographic functional share and total kidney volume at the age of 4, 12 and 24 weeks.

RESULTS

At age 4 weeks hydronephrosis was found in all obstructed kidneys included in the study. Four obstructed kidneys had renographic functional share 40% or greater and 1 deteriorated to less than 40% at 24 weeks. A total of 11 obstructed kidneys had a functional share less than 40%, 5 increased to a share greater than 40% at age 24 weeks and 3 had decreasing share from age 4 to 24 weeks. Single kidney glomerular filtration rate of the contralateral kidneys was significantly increased at all ages. Volume of the contralateral kidney was significantly increased at age 4 and 12 weeks.

CONCLUSIONS

The variability and course of renographic functional share in kidneys subjected to partial obstruction at age 2 weeks was similar to findings obtained in pigs obstructed at age 2 days. In contrast to these our study showed compensatory increase in function and size of the contralateral kidney, suggesting that contralateral compensation is an ability gained late in the nephrogenesis period.

Chronic treatment with epidermal growth factor induces growth of the rat ventral prostate

OBJECTIVE

The epidermal growth factor (EGF) system is expressed in the rat prostate, and growth factors from this system induce proliferation in prostate epithelial and stromal cell cultures. The aim of the study was to investigate the possible growth-promoting effects of the system during the hyperplastic growth phase of the prostate in newborn rats.

MATERIAL AND METHODS

Newborn rats were treated for 8 weeks with EGF (150 microg/kg body weight per day), administered as daily subcutaneous injections. Sections of the prostate tissue were examined by a stereological technique to determine tissue composition.

RESULTS

Treatment with EGF increased the weight of the ventral prostate, relative to body weight, by 50% compared with placebo (p < 0.005). Neither the dorsolateral prostate, seminal vesicles nor coagulating glands were affected by EGF. Prostate tissue showed a significant increase in the volume of the prostate epithelium, the stroma and the lumen following EGF treatment, in a pattern resembling physiological growth of the ventral prostate. A significant correlation (r = 0.78, p < 0.0001) of the volume fraction of the lumen with the glandular weight of the ventral prostate was seen. Serum testosterone was not affected by chronic EGF administration.

CONCLUSIONS

EGF selectively induces growth of the ventral lobe of the prostate in newborn rats, in a pattern comparable to normal physiological growth. It may be hypothesized that the physiological growth of the prostate is directly correlated to endogenous activity of the EGF system in the rat prostate gland.

Reduced renal vascular resistance in response to verapamil during gradated ureter obstruction in pigs

Unilateral ureteral obstruction (UUO) is associated with reductions in ipsilateral renal blood flow (RBF) and glomerular filtration rate (GFR) caused by an active preglomerular vasoconstriction, where angiotensin II (ANGII) may be an important mediator. Calcium-channel blockers preferentially dilate preglomerular vessels and abolish the vasoconstrictor actions of ANGII in preglomerular arterioles of the hydronephrotic rat kidney. In this study, we, therefore, examined the effects of the calcium-channel blocker verapamil (3.65 microg/kg per minute i.v.) on RBF, GFR and renal vascular resistance (RVR) in our pig model with UUO, where ultrasonic flow probes are mounted on each renal artery and catheters placed in the abdominal aorta and both renal veins. Verapamil treatment was associated with a 34% reduction in ipsilateral RBF (from 182.6 +/- 20.5 ml/min to 120.6 +/- 12.2 ml/min, P < 0.001), which was similar to the 27% reduction in ipsilateral RBF in controls (from 194.6 +/- 13.1 ml/min to 140.6 +/- 15.2 ml/min, P < 0.001). Ipsilateral GFR was reduced by 70% in the verapamil-treated pigs (from 29.0 +/- 2.6 to 8.5 +/- 0.9 ml/min, P < 0.001) and by 73% in control animals (from 29.2 +/- 3.1 to 7.6 +/- 2.1 ml/min, p < 0.001). However, the increase in RVR was significantly attenuated in the verapamil-treated pigs. Ipsilateral RVR increased by 19% in the verapamil-treated pigs (from 0.585 +/- 0.076 to 0.726 +/- 0.081 mmHg/min/ml, P < 0.05) compared with a 34% increase in control pigs (from 0.560 +/- 0.056 to 0.854 +/- 0.091 mmHg/min per milliliter, P<0.001), suggesting that an intact calcium-channel may be important for the increase in renal vascular resistance during unilateral ureter obstruction. In conclusion, the present study shows that verapamil is able to modulate the increase in renal vascular resistance in response to increased pelvic pressure.

Downregulation of AQP1, -2, and -3 after ureteral obstruction is associated with a long-term urine-concentrating defect

Previously, we demonstrated that 24 h of bilateral ureteral obstruction (BUO) and short-term release of BUO was associated with a decrease in the expression of aquaporin-2 (AQP2), polyuria, and a reduced urinary concentrating capacity (10). The purposes of the present study were to examine whether BUO and the long-term release of BUO (BUO-R) for 3, 14, and 30 days were associated with changes in the expression of renal AQP1, AQP2, and AQP3 and whether such changes were associated with parallel changes in urinary output and urinary concentrating capacity. Rats (n = 4-7 in each group) were kept in metabolic cages for measurements of urinary output. Kidneys were removed to determine the expression levels of AQP1, AQP2, and AQP3 by semiquantitative immunoblotting. AQP2 was downregulated after 24 h of BUO (42 +/- 3%). Downregulation of AQP2 persisted 3 (43 +/- 14%; P < 0.01) and 15 days after BUO-R (48 +/- 11%; P < 0.01) but was normalized 30 days after BUO-R. AQP3 showed a similar pattern. Moreover, AQP1 was downregulated in response to BUO (65 +/- 7%) and remained downregulated 3 days after BUO-R (41 +/- 5%), 14 days after BUO-R (57 +/- 8%), and 30 days after BUO-R (59 +/- 5%). BUO-R resulted in a significant polyuria that gradually decreased, although it remained significant at day 30. Urinary concentrating capacity remained significantly impaired when determined 3, 14, and 30 days after BUO-R in response to a 24-h period of thirst (1,712 +/- 270 vs. 2,880 +/- 91 mosmol/kgH2O at day 30, P < 0.05). In conclusion, the expression of AQP1, AQP2, and AQP3 were long-term downregulated after BUO-R, suggesting that dysregulation of aquaporins located at the proximal tubule, thin descending limb of the loop of Henle, and the collecting duct may contribute to the long-term polyuria and impairment of urinary concentrating capacity associated with obstructive nephropathy.

Male fetal pig lower urinary tract function in mid second and early third trimester of gestation

PURPOSE

Routine use of ultrasound during pregnancy has emphasized the need for greater knowledge about normal and abnormal voiding function during fetal live. We describe the developmental changes in lower urinary tract function from the middle of the second to the early third trimester of gestation.

MATERIALS AND METHODS

The study included 22 male fetal pigs of 13 pregnant Goettingen minipigs (gestational period 111 to 115 days) with 11 fetuses in the middle of the second (median 61.5 days, 0.55 of term) and 11 fetuses in the beginning of the third trimester of gestation (median 80 days, 0.72 of term). With the sow under isoflurane anesthesia catheters were placed in the bladder, rectum and amniotic cavity of the fetuses, and a flow probe was placed around the distal urethra. After the sow was at light sleep urethral flow, amniotic pressure, abdominal pressure and bladder pressure were recorded a median of 241 minutes.

RESULTS

The recordings of 14 fetuses were evaluable. In the middle of the second trimester the fetuses showed an almost constant dribbling with a median flow of 0.2 ml. per minute and a median of 4 concomitant bladder contractions per minute of median 3.5 cm. H2O (detrusor pressure). At the beginning of the third trimester the fetuses had periods of staccato flow (median 0.2 ml. per minute, staccato frequency 1 to 2 Hz.) on top of contractions (median 4 contractions per minute, median detrusor pressure 5.5 cm. H2O) with no flow between voidings.

CONCLUSIONS

Development of storage and voiding function in male pigs occurs between the mid-second and early third trimester of gestation, together with emergence of striated sphincter bursting activity, which interrupts flow in the urethra during the voiding phase.

Male fetal pig lower urinary tract function in mid second and early third trimester of gestation

PURPOSE

Routine use of ultrasound during pregnancy has emphasized the need for greater knowledge about normal and abnormal voiding function during fetal live. We describe the developmental changes in lower urinary tract function from the middle of the second to the early third trimester of gestation.

MATERIALS AND METHODS

The study included 22 male fetal pigs of 13 pregnant Goettingen minipigs (gestational period 111 to 115 days) with 11 fetuses in the middle of the second (median 61.5 days, 0.55 of term) and 11 fetuses in the beginning of the third trimester of gestation (median 80 days, 0.72 of term). With the sow under isoflurane anesthesia catheters were placed in the bladder, rectum and amniotic cavity of the fetuses, and a flow probe was placed around the distal urethra. After the sow was at light sleep urethral flow, amniotic pressure, abdominal pressure and bladder pressure were recorded a median of 241 minutes.

RESULTS

The recordings of 14 fetuses were evaluable. In the middle of the second trimester the fetuses showed an almost constant dribbling with a median flow of 0.2 ml. per minute and a median of 4 concomitant bladder contractions per minute of median 3.5 cm. H2O (detrusor pressure). At the beginning of the third trimester the fetuses had periods of staccato flow (median 0.2 ml. per minute, staccato frequency 1 to 2 Hz.) on top of contractions (median 4 contractions per minute, median detrusor pressure 5.5 cm. H2O) with no flow between voidings.

CONCLUSIONS

Development of storage and voiding function in male pigs occurs between the mid-second and early third trimester of gestation, together with emergence of striated sphincter bursting activity, which interrupts flow in the urethra during the voiding phase.

The intrarenal resistive index as a pathophysiological marker of obstructive uropathy

PURPOSE

The intrarenal resistive index is a physiological parameter that indirectly reflects the degree of resistance in the intrarenal vasculature. Resistive index measurements have been advocated for the diagnostic evaluation of several renal pathologies, including obstructive uropathy. However, despite extensive research in this field during the last decade clear guidelines on the use of resistive index measurements for discriminating obstructive from nonobstructive dilatation of the upper urinary tract remain elusive. Therefore, we reviewed the literature to clarify the proper role of resistive index measurements in the context of obstructive uropathy.

MATERIALS AND METHODS

We reviewed the recent literature on the use of resistive index measurements for the diagnostic evaluation of obstructive uropathy.

RESULTS

Despite a continuously growing body of literature the resistive index has yet to be recognized as a dependable parameter when it comes to resolving the long-standing dilemma of the dilated upper urinary tract. While proponents have observed that this method has sensitivity and specificity that supersede those of conventional methods, opponents have reported that the resistive index is an unreliable parameter that is prone to systemic and local influences.

CONCLUSIONS

Resistive index measurements are still in a developmental phase. Additional studies are needed before this technique may be used reliably for the diagnosis of obstructive uropathy.

Clinical options for imipramine in the management of urinary incontinence

Urinary incontinence is a common disorder in both childhood and adulthood. Proper treatment depends on insight into the pathophysiology and pharmacology of the lower urinary tract. This article reviews the mechanism of action of an old but commonly used drug, the tricyclic antidepressant agent imipramine, in nocturnal enuresis and stress and urge incontinence with reference to neuropharmacology and the relevant pathophysiology.

Smokeless nicotinergic stimulation of vasopressin secretion in patients with persisting nocturnal enuresis and controls

OBJECTIVE

This study aimed to evaluate the effect of nicotine stimulation on pituitary release of plasma arginine vasopressin (P(AVP)) in patients with primary monosymptomatic nocturnal enuresis (PMNE) and healthy control subjects.

MATERIAL AND METHODS

Postpubertal teenagers and adult enuretics as well as control subjects were enrolled into the study and admitted to hospital for measurements of P(AVP) in relation to intake of orally administered nicotine. Sixteen patients with PMNE (9 females, 7 males; aged 15-51 years, mean 23.5) and nine normal subjects (4 females, 5 males; aged 24-31 years, mean 27.3) were studied. The enuretics were characterized prior to investigation as either 1-desamino-8-D-arginine vasopressin (DDAVP) responders (n = 8; 16-51 years, mean 28.9) or DDAVP non-responders (n = 8; 15-24 years, mean 18.1) based on the reduction in the number of wet nights. P(AVP), mean arterial blood pressure (MAP) and heart rate (HR) were measured 0, 5, 10, 15 and 30 min, and plasma osmolality (P(osm)) 0 and 30 min after receiving 4 mg nicotine (Nicorette, Pharmacia & Upjohn) chewing gum.

RESULTS

In the compiled material a slight but statistically significant increase was observed in P(AVP) at 30 min compared with baseline levels, concurrent with significant rises in MAP and HR above baseline levels at 15 and 30 min. No difference was seen in P(osm) before and after nicotine administration. No other significant variation over time, assessed by an ANOVA, was detected. No difference was encountered in any measured parameter between controls and enuretics or between DDAVP responders and non-responders.

CONCLUSION

Smokeless nicotine chewing gum induces non-osmotic vasopressin release in humans. The secretory AVP capacity to this stimulation is normal in PMNE.

Renal function outcome in unilateral hydronephrosis in newborn pigs. II. Function and volume of contralateral kidneys

PURPOSE

We evaluated the compensatory response of contralateral kidney growth and function in pigs with unilateral hydronephrosis.

MATERIALS AND METHODS

Unilateral partial ureteral obstruction causing severe hydronephrosis was induced at age 2 days in 12 piglets, while 10 underwent sham operation. At ages 4, 12 and 24 weeks single kidney function was assessed using 99mtechnetium diethylenetriaminepentaacetic acid differential uptake on renography combined with the glomerular filtration rate estimated from the plasma clearance of 99mtechnetium diethylenetriaminepentaacetic acid. Kidney size was measured in parallel by magnetic resonance imaging.

RESULTS

At 4 weeks the glomerular filtration rate and volume of the contralateral kidneys did not differ from those in controls, although obstructed kidney function was significantly decreased. At 12 weeks the mean glomerular filtration rate plus or minus standard error of mean of the contralateral kidneys significantly increased to 1.60 +/- 0.11 versus 1.33 +/- 0.11 ml. per minute per kg. (p <0. 05), whereas kidney volume did not differ from that in sham operated controls. At 24 weeks the glomerular filtration rate and volume of the contralateral kidneys did not differ from those in controls. Glomerular filtration rate and volume of the contralateral kidneys did not correlate at 4 weeks but they correlated at 12 and 24 weeks (r = 0.94 and 0.89, respectively).

CONCLUSIONS

Initially kidneys contralateral to obstructed kidneys with decreased function had no increased growth or function. Furthermore, function and volume of the contralateral kidneys were not associated at the early age. Thus, the results of our study imply that determining the size (growth) or function of the contralateral kidney at an early age does not predict function decrease in a partially obstructed kidney in this pig model.

Current trends, diagnosis, and treatment of enuresis

This survey describes the evolution of our concept of monosymptomatic bedwetting over the last decades. It takes you briefly through psychology and enuresis. The minor role of bladder pathology is described ending up with focusing on the mismatch between bladder capacity at night-time and urine production. Monosymptomatic bedwetting should currently be regarded as an umbrella diagnosis allocated to children where daytime urinary problems have been excluded. Within the diagnosis of monosymptomatic bedwetting we can nowadays identify at least two groups. One is related to children who have a large night-time urine production and a normal bladder capacity, and the other is related to children who have a large night-time production, but a bladder capacity too small for the normal urine production. The genetic aspects are currently investigated. The results and this kind of research will probably end up in a further subgrouping.

A 14-year follow-up of conservative treatment for vesico-ureteric reflux

OBJECTIVE

To determine renal function in patients with vesico-ureteric reflux (VUR) during 14 years of conservative treatment (no surgery).

PATIENTS AND METHODS

Sixty patients with VUR were consecutively included between 1981 and 1982. The degree of VUR was determined by conventional voiding cysto-uretherography (VCUG) after 3 months of prophylactic antibiotics. The VUR was grade I-IV, with grades III and IV characterized as high-grade VUR. In all patients, any urinary tract infections and bladder-urethral dysfunction were treated. Renal function and reflux were monitored by renal and bladder scintigraphy using 123I-hippuran and the glomerular filtration rate (GFR) was determined using the plasma clearance of 51Cr-ethylaminediamine tetra-acetic acid.

RESULTS

Of the 60 patients who entered the study, 51 were followed for a mean of 13.7 years; nine patients were lost to follow-up. None of the patients underwent antireflux surgery. All patients were in good health and normotensive (except two with borderline hypertension). Of the 51 patients 21 had low-grade, 21 unilateral high-grade and nine bilateral high-grade reflux. In those with low-grade reflux both the mean renal split function on the most refluxing kidney and the GFR remained stable during the whole monitoring period. Eighteen patients who had a persistent reduction in renal split function or initially had had a significantly reduced functional share to the most refluxing kidney had their GFR re-assessed in adolescence. However, the body surface-corrected GFR remained constant. Total GFR and single kidney GFR increased significantly.

CONCLUSION

A conservative treatment regimen in patients with VUR can ensure stable kidney function, although kidneys with a lower renal function at referral seem to have an impaired functional growth potential.

Cystometry techniques in female infants and children

Cystometry is increasingly used in children, being an important diagnostic tool for congenital and acquired malformations such as neurogenic bladder, vesicoureteric reflux, urinary tract infection, urge syndrome, nocturnal enuresis, urinary incontinence and anorectal malformations. During cystometry bladder storage and voiding function can be evaluated. Carefully conducted urodynamic studies provide an insight into the pathophysiologic mechanisms involved in voiding dysfunctions that cannot be obtained by any other diagnostic technique. A variety of methods are available, the most sophisticated being filling and voiding cystometry with flowmetry and electromyography (EMG) under fluoroscopy, i.e. videocystometry. A detailed home recording of the frequency and volume of micturition can provide important clues as to the underlying bladder dysfunction, and can significantly aid in the choice of appropriate investigative techniques, as well as in the interpretation of subsequent urodynamic findings. It must be realized that urodynamic studies are invasive procedures and that artifacts may occur and influence the correct interpretation of the results. Infants and children have a different spectrum of bladder dysfunctions from adults and are generally much less cooperative during a urodynamic study. Therefore, cystometric techniques must be significantly modified. This article reviews cystometry techniques and their application in female infants and children. Cystometry/flow/EMG studies with or without fluoroscopy, ambulatory urodynamics and telemetric urodynamic measurement and their application are outlined.

In vivo measurements of relaxivities in the rat kidney cortex

The aim of this study was to implement a novel noninvasive method to derive the in vivo T1 relaxivity (R1) and T2 relaxivity (R2) in the rat kidney cortex. A two-compartment gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) distribution model was established to estimate the bolus and infusion dosages of Gd-DTPA necessary for obtaining the required steady-state concentration levels. After a single bolus injection of (99m)Tc-DTPA, several blood samples were collected. Based on considerations from the applied two-compartment model, a steady-state concentration was predicted approximately 5-10 minutes after the bolus injection. The plasma concentration levels of Gd-DTPA were measured by simultaneous injection of (99m)Tc-DTPA. Three regions in the cortex (upper, central, and lower) of both rat kidneys were used. A statistical evaluation resulted in the following in vivo relaxivities found at 7 T: R1 = 1.04 +/- 0.08 mM(-1)s(-1) and R2 = 10.78 +/- 0.83 mM(-1)s(-1). Using a 95% confidence interval, no intracortical differences were detected. The relaxivities R1 and R2 calculated in the intact rat kidney cortex were distinctly different from relaxivities found in human plasma: (22 degrees C) 4.42 +/- 0.07 mM(-1)s(-1) (r2> 0.98) and R2 = 5.75 +/- 0.17 mM(-1)s(-1) (r2> 0.98), respectively. The measurements showed a marked difference between in vitro and in vivo relaxivities. Comparison of the distribution rates in pig, human, and rats shows a distinct proportionality between size and renal function.

Renal functional outcome in unilateral hydronephrosis in newborn pigs

PURPOSE

We followed the course of neonatally induced, partial unilateral ureteral obstruction in pigs and established whether early function or morphological evaluation of the hydronephrotic kidney is predictive of outcome.

MATERIALS AND METHODS

In 25 piglets unilateral partial ureteropelvic obstruction was induced 2 days after birth, while 11 underwent sham operation. Only obstructed kidneys with significant dilatation at 4 weeks were included for further study. Renal function was assessed on renography using (99m)technetium-diaminetriaminepentaacetic acid differential uptake. According to the plasma clearance of (99m)technetium-diaminetriaminepentaacetic acid the glomerular filtration rate was determined at ages 4, 12 and 24 weeks. Kidney morphology was studied in parallel by magnetic resonance imaging.

RESULTS

A total of 12 obstructed kidneys with grade 3 or 4 hydronephrosis fulfilled study inclusion criteria. Of 6 kidneys with a functional share of 40% or greater at age 4 weeks 2 deteriorated to less than 40% at 24 weeks, while 4 of 6 with a share of less than 40% at age 4 weeks improved to greater than 40% at 24 weeks. The single kidney glomerular filtration rate at 4 weeks did not correlate with that at 12 or 24 weeks but the rate at 12 weeks correlated with that at 24 weeks (r2 = 0.8140, p <0.001). Neither relative volume of the obstructed kidney nor length of the contralateral nonobstructed kidney correlated with functional share of the obstructed kidney at any age.

CONCLUSIONS

Early evaluation of kidney function or volume, or contralateral kidney length did not predict the outcome of neonatally induced unilateral hydronephrosis in pigs.

[Urinary incontinence and pregnancy, vaginal childbirth and obstetric interventions]

The aim was to examine the association between pregnancy, vaginal childbirth (VC) and obstetric techniques, and the prevalence of urinary incontinence (UI). A cross-sectional survey enrolled a random population sample of 6240 women aged 20-59 years, who were mailed a self-administered questionnaire on UI and, among other things, experience of VC and obstetric intervention. More than 75% responded. The present analysis includes 4345 women. Multivariate UI prevalence odds ratios were increased in relation to UI during pregnancy, UI following immediately after a VC, and age 30 or more at the second VC. No multivariate association was found in relation to forceps delivery or vacuum extraction delivery, episiotomy or perineal suturing. In conclusions, not only the process of childbirth itself but also processes during pregnancy seem to be strongly associated with prevalent UI. Perineal suturing may be associated with prevalent UI, whereas other obstetric techniques inspected do not seem to be so.