Hydronephrosis associated with antiurothelial and antinuclear autoantibodies in BALB/c-Fcgr2b-/-Pdcd1-/- mice

Because most autoimmune diseases are polygenic, analysis of the synergistic involvement of various immune regulators is essential for a complete understanding of the molecular pathology of these diseases. We report the regulation of autoimmune diseases by epistatic effects of two immunoinhibitory receptors, low affinity type IIb Fc receptor for IgG (FcγRIIB) and programmed cell death 1 (PD-1). Approximately one third of the BALB/c-Fcgr2b^−/−Pdcd1^−/− mice developed autoimmune hydronephrosis, which is not observed in either BALB/c-Fcgr2b^−/− or BALB/c-Pdcd1^−/− mice. Hydronephrotic mice produced autoantibodies (autoAbs) against urothelial antigens, including uroplakin IIIa, and these antibodies were deposited on the urothelial cells of the urinary bladder. In addition, ∼15% of the BALB/c-Fcgr2b^−/−Pdcd1^−/− mice produced antinuclear autoAbs. In contrast, the frequency of the autoimmune cardiomyopathy and the production of anti–parietal cell autoAb, which were observed in BALB/c-Pdcd1^−/− mice, were not affected by the additional FcγRIIB deficiency. These observations suggest cross talk between two immunoinhibitory receptors, FcγRIIB and PD-1, on the regulation of autoimmune diseases.

Epidermal growth factor potentiates renal cell death in hydronephrotic neonatal mice, but cell survival in rats

BACKGROUND

Epidermal growth factor (EGF) markedly attenuates tubular apoptosis induced by unilateral ureteral obstruction (UUO) in the neonatal rat, and reduces apoptosis induced by mechanical stretch of cultured rat tubular cells.

METHODS

To investigate the role of EGF in modulating apoptosis resulting from UUO, neonatal wild type and mutant mice lacking EGF (knockout), or with diminished EGF receptor activity (waved-2 mutant) were compared to control mice for tubular apoptosis and atrophy. Rat and mouse kidneys were compared for localization of the EGF receptor. Apoptosis was also measured in cultured mouse tubular cells subjected to stretch and exposed to EGF.

RESULTS

UUO reduced endogenous renal EGF expression in wild-type mice. Unlike the rat, exogenous EGF did not decrease tubular apoptosis or atrophy in the obstructed kidney, and significantly increased stretch-induced apoptosis of cultured mouse tubular cells. Tubular apoptosis was 50% lower in the obstructed kidney of EGF knockout and waved-2 mice relative to wild type and heterozygous animals. Exogenous EGF increased tubular apoptosis and doubled atrophy in the obstructed kidney of waved-2 mice. Species differences in EGF receptor localization were detected in 3-day-old kidneys.

CONCLUSION

EGF acts as a survival factor in the neonatal rat, but potentiates tubular cell death in the neonatal mouse. Species differences are maintained in cultured cells, suggesting that differences in EGF receptor signaling underlie these opposing effects.

Lim 1 is required for nephric duct extension and ureteric bud morphogenesis

The nephric duct plays a central role in orchestrating the development of the mammalian urogenital system. Lim 1 is a homeobox gene required for head and urogenital development in the mouse but most Lim 1-deficient embryos die by embryonic day 10. To determine the role of Lim 1 in the development of the nephric duct, we conditionally removed Lim 1 in the nephric epithelium just after the nephric duct begins to form using a floxed allele of Lim 1 and Pax2-cre transgenic mice. We report that Lim 1 conditional knockout mice have renal hypoplasia and hydronephrosis. Developmental studies revealed that the caudal portion of the nephric duct did not reach the urogenital sinus at embryonic day 10.5, formation of the ureteric bud was delayed, the ureteric bud was smaller and branching of the ureteric bud reduced. We also found that the nephric duct was generally not maintained and extension of the Müllerian duct inhibited. Molecular analysis indicated that Pax2 was expressed normally but the expression of Wnt9b and E-cadherin in the nephric duct was markedly altered. These results suggest that Lim 1 influences nephric duct extension and ureteric bud outgrowth by regulating and or maintaining the differentiation of the nephric epithelium.

Unilateral perinephric pseudocyst secondary to hydronephrosis in a C57BL/6J mouse

A 9-month-old C57BL/6J mouse had progressive abdominal distension over a 1-week period, and a distended left renal capsule was discovered at postmortem examination. Incision of the capsule showed a tan, cloudy fluid that separated the renal capsule and the remnant left kidney. Microscopically, the capsule was significantly separated from the renal parenchyma by clear space and necrotic cellular debris. The majority of the lining of the renal capsule was composed of fibrous connective tissue and lacked an epithelial lining, consistent with a subcapsular perinephric pseudocyst. In addition, attached to intermittent portions of the renal capsule were thin rims of compressed cortical tissue lined by transitional epithelium. The finding of remnant cortical tissue lined by transitional epithelium is consistent with severe hydronephrosis and indicates that the hydronephrosis preceded the formation of the perinephric pseudocyst. To our knowledge, this is the first case report to characterize a perinephric pseudocyst secondary to severe hydronephrosis in a mouse.

Id2 haploinsufficiency in mice leads to congenital hydronephrosis resembling that in humans

Congenital hydronephrosis is one of the most common anomalies found in humans and may cause renal failure in childhood. Half of the cases are due to obstruction at the ureteropelvic junction (UPJ). Here we report that mice lacking Id2, an inhibitor of basic helix-loop-helix (bHLH) transcription factors, exhibit hydronephrosis mimicking the characteristics of human cases such as unilaterality and male preponderance. Hydronephrosis was found even in Id2+/- mice. The penetrance was 67.2% in Id2-/- males, 48.8% in Id2+/- males, 28.0% in Id2-/- females and 20.0% in Id2+/- females. Distortion or high insertion of the ureter at the UPJ was frequently observed and these morphological changes were evident in late embryogenesis. Histologically, the muscle layer, where Id2 is normally expressed, was hypertrophic and/or irregular at the UPJ. Furthermore, gene expression analysis suggested that BMP4 (bone morphogenetic protein 4), which is known to be involved in the development of hydronephrosis, appears to function as an upstream factor of Id2. Our results thus raise the possibility that Id2 is a gene responsible for the pathogenesis of hydronephrosis in man.

Renal pelvis volume during diuresis in children with hydronephrosis: implications for diagnosing obstruction with diuretic renography

PURPOSE

We measured the volume of the renal pelvis during diuretic renography (DR) in children with normal and hydronephrotic kidneys to determine if changes in pelvic volume could affect the accuracy of DR in diagnosing obstruction.

MATERIALS AND METHODS

We studied 18 patients 1 month to 10 years old with unilateral hydronephrosis ultimately proved to be either obstructive or nonobstructive. Simultaneous DR and ultrasound were performed with patients supine using the gamma camera. Ultrasound measurements of the renal pelvis in 3 dimensions, obtained before and at intervals after diuretic injection, were used to calculate renal pelvic volume. The contralateral normal kidneys were used as controls.

RESULTS

Between 15 and 60 minutes after diuretic injection the renal pelvis enlarged to a maximum volume in all hydronephrotic and normal kidneys and then gradually decreased in size. Mean average increase in volume for hydronephrotic kidneys ranged from 46% in obstructed kidneys to 88% in nonobstructed kidneys. Volume expansion caused dilution of isotope within the renal pelvis, which resulted in prolongation of elimination half-time (T1/2) in 42% of nonobstructed hydronephrotic kidneys sufficient to register an obstructed washout pattern. However, there were no differences in the initial pelvic volume or the rate or extent of increases or decreases in pelvic volume that would permit nonobstructed hydronephrotic kidneys to be distinguished from obstructed ones.

CONCLUSIONS

The renal pelvis enlarges during diuresis in children with hydronephrosis. This enlargement causes dilution of isotope within the renal pelvis during DR, which prolonged the isotope washout rate or T1/2 sufficiently to produce an obstructed washout pattern in more than 40% of hydronephrotic kidneys that were ultimately proved to be nonobstructed. This misdiagnosis of obstruction is particularly likely to occur in children younger than 2 years because pelvic volume expansion is so exaggerated. Consequently, T1/2 appears to be particularly vulnerable to inaccuracy in diagnosing obstruction in this age group, and, therefore, it should not be relied on as an operative determinant.

Hydronephrosis as a prognostic factor in pelvic recurrence from rectal and colon carcinomas

BACKGROUND

After multimodal treatment estimated 5-year survival of locally recurrent rectal cancer is about 25%. Hydronephrosis secondary to pelvic recurrence of colorectal cancer is a condition claimed to represent a contraindication to surgery due to a dismal prognosis.

METHODS

Prospective registration of 193 consecutive patients operated for pelvic recurrence in rectal or colon cancer from January 1991 until March 2002 at a tertiary referral hospital, 121 men and 72 women, median age 67 years, all given irradiation preoperatively. Twenty-three of 193 had hydronephrosis prior to preoperative irradiation for recurrent disease.

RESULTS

R-0 stage resection was obtained in 22% of patients with hydronephrosis and in 41% without. The median survival times in patients without metastasis were 27 and 32 months, respectively, and 5-year survival rates were 11% and 25%.

CONCLUSIONS

An aggressive surgical approach offers patients with pelvic recurrence from rectal and colon cancer the best potential for survival. The presence of hydronephrosis probably indicates a lower chance for complete surgical resection of the recurrence, but local control and improved survival may still be achieved, and about two thirds of patients may benefit from the operation.

Congenital unilateral hydronephrosis: a review of the impact of diuretic renography on clinical treatment

PURPOSE

The natural history of and optimal treatment for asymptomatic congenital hydronephrosis is unknown, mainly because most published series are nonrandomized or retrospective with nonstandardized followup regimens. In this survey we provide an overview of the different strategies used for the treatment of congenital unilateral hydronephrosis.

MATERIALS AND METHODS

A comprehensive literature review of clinical studies of asymptomatic congenital unilateral hydronephrosis is presented.

RESULTS

Different criteria for surgical intervention and different followup regimens have been used. Identification of the population at risk has been attempted but results are ambiguous. Surgery is done in approximately 25% of cases when using deteriorating differential function, symptoms and/or increasing hydronephrosis as criteria for operation. A nonstandardized renographic assessment does not compromise evaluation of the ideal followup but it may compromise the functional outcome.

CONCLUSIONS

More studies of kidneys with decreased function, severe hydronephrosis or poor drainage investigated with a standardized protocol are needed to clarify the natural history and establish optimal guidelines for treatment and followup.

Outcome of fetal renal pelvic dilatation diagnosed during the third trimester

OBJECTIVES

The aim of this study was to evaluate renal function and the need for postnatal treatment--antibiotic therapy and/or surgery--in relation to the grade of fetal renal pelvic dilatation (RPD) found on third-trimester ultrasound examination.

METHODS

The retrospective study included 78 children, born between 1995 and 2000, with 115 dilated fetal renal pelvic units. The children were allocated to three groups based on pelvic anteroposterior diameter (APD) detected on third-trimester ultrasound: APDs of 7-9.9 mm, 10-14.9 mm and > or = 15 mm were classified as mild dilatation, moderate hydronephrosis and severe hydronephrosis, respectively. Renal function was assessed by scintigraphy.

RESULTS

None of the 20 children with mild dilatation experienced a urinary tract infection (UTI) or underwent surgery; two had associated renal or urinary tract abnormalities. In contrast, five out of 22 (23%) children with moderate hydronephrosis and 23 out of 36 (64%) with severe hydronephrosis had either a UTI or required surgery (P < 0.001); associated abnormalities were also more common (6 out of 22 and 15 out of 36, respectively). There was no significant correlation between the grade of antenatal RPD and postnatal ipsilateral renal function.

CONCLUSIONS

The need for postnatal treatment increased significantly with the grade of antenatal RPD. Children with antenatal mild dilatation were discharged early from follow-up whereas those with moderate and severe fetal hydronephrosis needed close follow-up by a multidisciplinary team.

Adriamycin-induced fetal hydronephrosis

INTRODUCTION

At the end of pregnancy, the amniotic fluid (AF) depends basically on renal function, corresponding to fetal urine. Changes in AF, especially oligohydramnios, are reported in association with fetal hydronephrosis (FH). The experimental model using adriamycin in pregnant female rats has a teratogenic effect and has been classically employed to study esophageal atresia. Nevertheless, adriamycin promotes FH with high frequency as well. In the present study, using this animal model, we tried to identify the incidence and microscopic changes of FH, as well as its correlation with AF weight.

MATERIALS AND METHODS

Eight Spreague-Dawley pregnant female rats received adriamycin 2.2 mg/kg on the 8th and 9th gestational days (considering term gestation = 22 days). Those fetuses that received adriamycin (Adriamycin Group) were compared with fetuses from 2 female rats (Control Group), which received 0.9% saline solution. On the 21.5 gestational day, the fetuses were collected by cesarean incision, sacrificed, and examined for macro and microscopic changes in kidneys and ureters. Fetuses with bilateral hydronephrosis formed the Hydronephrosis Group. AF weight was determined as well.

RESULTS

Hydronephrosis occurred in 70 (95%) of the 74 fetuses in the adriamycin group against none of the 21 fetuses from the control group. The amniotic fluid weight was increased in the adriamycin group in relation to the control group (p < 0.001). The histomorphometric study revealed dilation of the renal pelvis and reduction of renal parenchyma in the hydronephrosis group in relation to the control group. Severe cortical atrophy, cortical tubular atrophy and medullar atrophy were observed in the hydronephrosis group.

CONCLUSIONS

Slight renal lesions were in agreement with changes in AF weight, since they suggest that there was production of urine with the maintenance of AF.

Prenatal diagnosis and management of mild fetal pyelectasis: implications for neonatal outcome and follow-up

OBJECTIVES

To describe the natural history of pyelectasis from its detection in the second trimester to delivery, its capability to predict renal pathology and whether prenatal development of pelvic dilatation is correlated to its postnatal evolution.

STUDY DESIGN

A retrospective analysis involving 375 fetuses with a complete urological follow-up. Prenatal ultrasound was correlated with the results of postnatal investigation and frequency of postnatal surgery was established.

RESULTS

Two-hundred and eighty cases underwent at least two examinations before birth. 73.1% were male fetuses. 57.4% had a bilateral pyelectasis. Prenatal evolution of pelvic dilatation was the following:18.6% of the cases normalized, in 34.6% of the cases the dilatation reduced but did not disappear, in 30.7% it remained unchanged, while it worsened in 16.4%. One case from the first group, three cases from the second, seven cases from the third and 11 cases from the fourth needed surgical treatment. 1.9, 7.2, 18.6, 23.9% of cases respectively worsened after birth in the four groups (trend: P=0.001).

CONCLUSIONS

Prenatal diagnosis of pyelectasis improves the outcome of these children due to a surgical approach that avoids renal damage. There is a good correlation between prenatal evolution and postnatal outcome, although a postnatal follow-up is opportune in those cases that normalized before birth.

Selective decrease in urinary aquaporin 2 and increase in prostaglandin E2 excretion is associated with postobstructive polyuria in human congenital hydronephrosis

This study was undertaken to determine the role of aquaporin 2 (AQP2) in the impaired urinary concentrating capacity observed in patients who underwent pyeloplasty because of congenital unilateral hydronephrosis as a result of pyeloureteral junction disease. Twelve children (mean age, 8 +/- 2 mo) were examined in the study. From day 1 to day 5 after surgery, the urine was collected separately from pyelostomy draining only from the postobstructed kidney and from the bladder catheter draining mostly from the contralateral kidney used as internal control. After pyeloplasty, the postobstructed kidney was characterized by a reduced urinary excretion of AQP2 (approximately 54%) associated with polyuria that persisted from day 1 to day 5 (433 +/- 58 versus 310 +/- 74 ml/24 h at day 1; 326 +/- 44 versus 227 +/- 26 ml/24 h at day 5). In parallel, urine osmolality from the postobstructed kidney was significantly reduced compared with the contralateral kidney (111 +/- 12 versus 206 +/- 49 at day 1; 136 +/- 24 versus 235 +/- 65 mOsm/kg at day 5). Creatinine clearance from the postobstructed kidney was not significantly different compared with the contralateral kidney throughout the 4 d after surgery. However, on day 5, creatinine clearance from the postobstructed kidney became significantly lower. Prostaglandin E2 in the urine from postobstructed kidneys was found to be twofold higher than in the contralateral samples (26.0 +/- 6.7 versus 13.5 +/- 2.5 at day 5). It is concluded that (1) the selective downregulation of AQP2 in postobstructed kidney may account for the higher excretion of hypotonic urine, and (2) the local increase in prostaglandin E2 synthesis in postobstructed kidney may be involved in AQP2 downregulation and in maintaining a GFR similar to that of the contralateral kidney.

Role of protein kinase C in Ca channel blocker-induced renal arteriolar dilation in spontaneously hypertensive rats

The present study examined the role of L-/T-type Ca channels and the interaction between these channels and protein kinase C (PKC) in hypertension. The isolated perfused hydronephrotic rat kidney model was used to visualize directly the renal microvascular effects of L-/T-type Ca channel blockers (nifedipine and mibefradil, respectively). Nifedipine reversed the angiotensin II-induced constriction of afferent, but not efferent, arterioles in kidneys from Wistar-Kyoto rats (WKY), and similar magnitude in dilation was observed in spontaneously hypertensive rats (SHR). Although mibefradil elicited dilation of both arterioles, the afferent arteriolar dilation was less in SHR than in WKY (57+/-5% vs. 80+/-4% reversal at 1 micrommol/L). The pretreatment with staurosporine did not alter the angiotensin II-induced afferent arteriolar constriction in WKY, but attenuated this response in SHR. Furthermore, staurosporine enhanced the nifedipine-induced afferent arteriolar dilation (62+/-3% vs. 50+/-3% reversal at 10 nmol/L), and restored the attenuated afferent arteriolar response to mibefradil in SHR. The pretreatment with thapsigargin (a blocker of IP3-mediated intracellular calcium release) prevented the angiotensin II-induced afferent arteriolar constriction in WKY, but caused a significant constriction of afferent arterioles in SHR and efferent arterioles in WKY and SHR; in this setting, mibefradil did not alter efferent arteriolar tone. In conclusion, although both L-type (nifedipine) and T-type Ca channel blockers (mibefradil) exerted potent vasodilation of rat renal microvessels, these actions were modified by PKC, which determined the afferent arteriolar sensitivity to these blockers in SHR. Furthermore, the enhancement in nifedipine-induced afferent arteriolar dilation by staurosporine in SHR suggests that L-type Ca channel activity is augmented in hypertensive animals.

Idiopathic Neurohypophysial Diabetes Insipidus: Reversibility of Structural and Functional Renal Abnormalities after Treatment

OBJECTIVE

To present a case of untreated long-term idiopathic neurohypophysial diabetes insipidus (DI) with structural and functional renal abnormalities that regressed after treatment.

METHODS

We describe the clinical course, biochemical data, and imaging findings in a man with idiopathic neurohypophysial DI in whom structural and functional abnormalities involving the urinary tract diminished after treatment. The patient underwent intravenous pyelography, retrograde pyelography, computed tomographic (CT) scanning of the kidneys and abdomen, iodohippurate renal scanning, and voiding cystourethrography. Ultrasonography of the kidneys at presentation and at 8-year followup and serial determinations of serum creatinine for a period of 9 years were also done.

RESULTS

A 43-year-old man had polyuria for 30 years attributable to untreated idiopathic neurohypophysial DI. He presented with bilateral flank pain and a high serum creatinine level (156 mmol/L). Ultrasonography, intravenous pyelography, retrograde pyelography, and CT scan of the kidneys demonstrated severe bilateral hydronephrosis, notably dilated and tortuous ureters, a distended bladder, and atrophy of the left renal cortex. Retrograde pyelography and voiding cystourethrography confirmed the absence of mechanical obstruction or urinary reflux. A renal scan study showed bilaterally impaired function. Treatment with intranasally administered desmopressin and clean intermittent straight bladder catheterization resulted in resolution of flank pain, improvement of renal function, normalization of serum creatinine levels, and decreased hydronephrosis during 9 years of follow-up.

CONCLUSION

This case provides information about renal abnormalities in the natural history of a long-term polyuric state, idiopathic neurohypophysial DI, before and after treatment. Reversibility of renal structural and functional abnormalities after treatment is documented. Recognition of renal abnormalities associated with untreated neurohypophysial DI is important for prevention and treatment of such complications.

Functional sodium magnetic resonance imaging of the intact rat kidney

BACKGROUND

Renal fluid homeostasis depends to a large extent on the sodium concentration gradient along the corticomedullary axis. The spatial distribution and extent of this gradient were previously determined by invasive methods, which yielded a range of results. We demonstrate here the capacity of sodium magnetic resonance imaging (MRI) to quantify non-invasively renal sodium distribution in the intact kidney.

METHODS

Sodium MRI was applied to study normal, diuretic, and obstructed rat kidneys in vivo. The images were recorded at 4.7 Tesla using a 3-dimensional gradient echo sequence, with high spatial and temporal resolution. The tissue sodium concentration (TSC) was obtained by taking into account the measured nuclear relaxation rates and MRI visibility relative to a reference saline solution.

RESULTS

The corticomedullary sodium gradient increased linearly from the cortex to the inner medulla by approximately 31 mmol/L/mm, from a TSC of approximately 60 mmol/L to approximately 360 mmol/L. Furosemide induced a 50% reduction in the inner-medulla sodium and a 25% increase in the cortical sodium. The kinetics of these changes was related to the specific site and mechanism of the loop diuretic. Distinct profiles of the sodium gradient were observed in acute obstructed kidneys, as well as spontaneously obstructed kidneys. The changes in the sodium gradient correlated with the extent of damage and the residual function of the kidneys.

CONCLUSION

Quantitative assessment of the renal corticomedullary sodium gradient by high resolution sodium MRI may help verify new aspects of the kidney concentrating mechanism and serve as a non-invasive diagnostic method of renal function.

MR Imaging of Maternal Diseases of the Abdomen and Pelvis during Pregnancy and the Immediate Postpartum Period

Magnetic resonance (MR) imaging provides multiplanar large field-of-view images of the body with excellent soft-tissue contrast and without ionizing radiation. As a result, MR imaging is increasingly being used to image the maternal abdomen and pelvis during and immediately after pregnancy. Results of rapid T1- and T2-weighted imaging are often diagnostic, and blood vessels, ductal structures, and the urinary tract can frequently be visualized without intravenous administration of contrast material. Until more conclusive safety data become available, MR imaging should be reserved for cases in which results of ultrasonography are inconclusive and patient care depends on further imaging. In the setting of acute abdomen during pregnancy, MR imaging allows identification of areas of inflammation, abscess formation, hemorrhage, and bowel obstruction. MR imaging also helps determine the organ of origin, extent, and composition of maternal neoplasms and is useful in evaluation of müllerian duct anomalies and abnormalities of placental formation, position, and implantation. Many postpartum complications such as retained products of conception and uterine dehiscence may be diagnosed with MR imaging when results of other modalities are indeterminate.

Increased nephron volume is not a cause of supranormal renographic differential renal function in patients with ureteropelvic junction obstruction

PURPOSE

Increasing clinical importance is being placed on the role of differential renal function (DRF) in the management of congenital ureteropelvic junction obstruction. Supranormal DRF of the hydronephrotic kidney on renal scan is a puzzling phenomenon and is hypothesized to be due to an increase in single nephron filtration or nephron volume without sound evidence. We studied the histopathological changes of hydronephrotic kidneys to determine whether glomerular hypertrophy underlies supranormal DRF.

MATERIALS AND METHODS

We retrospectively evaluated the records of 3 females and 32 males with unilateral congenital hydronephrosis who underwent pyeloplasty. Mean patient age at operation was 12.6 months (range 0.1 to 144). Needle biopsies from 3 different sites at the lower pole of the kidney were performed during surgery. To evaluate the presence of glomerular hypertrophy, the maximal planar area of glomeruli was measured under light microscopy using an image analyzer. Tissue samples obtained from kidneys without a history of urinary tract disease at autopsy were used as controls. The mean glomerular areas of the patient and control groups were evaluated according to DRF and age.

RESULTS

The mean glomerular area values of the patient group were smaller than those of the control group, except for 4 patients. The glomerular areas of the hydronephrotic kidneys with supranormal DRF were not significantly different from those of the control group. Instead, the probability of larger renal glomeruli increased with decreasing DRF (p = 0.1155).

CONCLUSIONS

Increased nephron volume can be discounted as a cause of supranormal DRF.

WHEN CAN PERSISTENT HYDROURETERONEPHROSIS IN POSTERIOR URETHRAL VALVE DISEASE BE CONSIDERED RESIDUAL STRETCHING?

PURPOSE

Persistent hydroureteronephrosis (HUN) is often seen in boys with a history of a posterior urethral valve even years after valve ablation and it is often assumed to represent residual stretching. We determined the association of HUN with urodynamic abnormalities, the effect on HUN of treating these abnormalities and when persistent HUN could be considered residual stretching.

MATERIALS AND METHODS

Of 71 patients with a posterior urethral valve evaluated after valve ablation 20 (28.2%) had persistent HUN in a total of 32 renal units (RUs). The degree of HUN was graded as mild, moderate or severe. Videourodynamics were performed in all patients with persistent HUN and abnormal urodynamic findings were aggressively treated. HUN was then reassessed and categorized as resolved, improved or unchanged.

RESULTS

Abnormal urodynamic findings, primarily hypocompliance and instability, were noted in all 20 patients with HUN. All patients compliant with treatment showed dramatic improvement or complete resolution of abnormal urodynamic parameters. The 32 RUs with persistent HUN were initially graded as mild (8), moderate (13) and severe (11). HUN resolved in 15 RUs and improved to a lower grade in 11 in 26 of the 27 RUs (96.3%) in the 17 patients compliant with treatment. The 3 boys (5 RUs) who were noncompliant with treatment had neither decreased HUN nor improved urodynamic parameters. The 12 of 27 RUs (44.4%) in the treatment group in which HUN failed to resolve completely had no distal ureteral obstruction or identifiable persistent urodynamic abnormality and, thus, they can be labeled as having residual stretching.

CONCLUSIONS

Persistent HUN following valve ablation should not be considered residual dilatation until a thorough urodynamic evaluation has been done and any abnormal parameters are addressed. With correction of these abnormal parameters one can expect significant lessening of HUN and hopefully improved long-term preservation of renal function.

Giant hydronephrosis with increased carbohydrate antigen 19-9 both in serum and fluid

We report a case of right giant hydronephrosis. A 68-year-old man was admitted to our hospital with chief complaints of general fatigue, loss of appetite and a one-year history of progressive fullness on whole abdomen. Abdominal computed tomography scan exhibited a huge, homogeneous, low density mass originating from the right kidney. We performed right percutaneous nephrostomy and drained over 6,500 ml bloody fluid. Cytological examination of the drained fluid revealed atypical nuclear appearance defined as class III. Increased values of carbohydrate antigen 19-9 were observed both in the fluid as well as in the serum. We performed right nephrectomy. Macroscopic appearance of the resected kidney showed marked stenosis at the portion of ureteropelvic junction. Histological analysis of the stenotic portion demonstrated marked fibrosis without findings of malignancy.

Increased incidence of spontaneous malformations in pups and increased litter size from pinealectomized dams

The aim of the present study was to clarify whether maternal pinealectomy increases: (i) the incidence of spontaneous malformations in offspring; and (ii) litter size. More than 30 female rats in each of the control groups (normal and sham-pinealectomized) and the pinealectomized group were mated repeatedly with normal male rats and pups were autopsied mostly before weaning. No malformations were seen in offspring from the normal and sham-pinealectomized groups (n = 350 and n = 736, respectively). In contrast, in offspring from pinealectomized mothers (n = 1123), spontaneous malformations were found in five (taillessness in three and unilateral hydronephrosis or large renal cyst in the other two) or maybe six (unilateral renal hypoplasia in another) pups. This increased incidence of malformations in the latter group was statistically significant (P < 0.034 or 0.017 (Fisher's exact test), respectively). The frequency of still-born cases was not higher in pups born from pinealectomized mothers. The mean litter size was larger in the pinealectomized group compared with the control groups (P < 0.005-0.001, Student's t-test) at the first delivery (at approximately 100 days of age), but was not different at later deliveries at older ages. Our results suggest that the maternal pineal hormone suppresses: (i) the incidence of spontaneous malformations in offspring until mothers reach an old age; and (ii) litter size during the reproductively maturational phase of life.

Ureteral leiomyoma causing hydronephrosis in Type 1 multiple endocrine neoplasia

A rare case of leiomyoma of the ureter in a patient with type 1 multiple endocrine neoplasia (MEN) is reported. The case is of a Japanese man in his forties who had a past history of parathyroid gland hyperplasia, pancreatic islet cell tumors, and bilateral adrenocortical nodular hyperplasia. The leiomyoma, measuring 15 x 13 x 12 mm, was located in the right upper ureter, obstructing the lumen and causing hydronephrosis. Three small leiomyomas were also detected in the lower portion. Furthermore, histological examination revealed three tiny leiomyomatous nodules embedded in the muscular layer. It has been reported that type 1 MEN is often complicated by multiple leiomyoma in many organs, including the esophagus, stomach, lung, uterus, and skin. However, it is believed that this is the first report of leiomyomatosis of the ureter occurring in a patient with type 1 MEN. It should be recognized that multiple ureteral leiomyomas may develop in patients of type 1 MEN and can potentially result in hydronephrosis. The multiple development of leiomyoma suggests a causal relationship to MEN1 gene alteration.

Urolithiasis associated with experimental lymphocytic choriomeningitis virus inoculation in Lewis rats

A high frequency of struvite urolithiasis, hydronephrosis, and other urinary tract lesions developed in a group of Lewis rats inoculated intracranially with lymphocytic choriomeningitis virus (LCMV). Initially, clinically ill rats were referred to necropsy: 30 rats over 3 years. These rats had high frequency of urolithiasis (8/30, 27%), hydronephrosis (12/30, 40%), cystitis (9/30, 30%), transitional cell carcinoma (4/30, 13%), and pyelonephritis (19/30, 63%). Lesions were more common in LCMV-inoculated rats. After this trend was noted, all rats on this protocol were necropsied as part of a cohort study (n = 144). Although the apparent frequency of disease was lower due to increased sampling, there still was a high number of urolithiasis (9/144, 6%) and hydronephrosis (40/144, 28%) cases. All cases of urolithiasis developed in rats inoculated with LCMV (9/44, 20%), as did most cases of hydronephrosis (31/44, 70%). Although sham-injected and uninoculated control rats also had high frequency of hydronephrosis (6/57 [11%] and 3/43 [7%], respectively), LCMV-inoculated rats had a significantly higher frequency of disease than did sham inoculated (P < 0.0001) and uninoculated (P < 0.0001) controls. These results suggest that Lewis rats may be predisposed to developing lesions of the urinary tract, and that intracranial inoculation of rats with LCMV augments this tendency, leading to formation of struvite calculi and associated urinary tract disease.