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Biomedical subjects

M Maizels

Publications and source records attributed to M Maizels.

At least 19 recordsLinked to original sources
PubMed1999

Single system ureteral ectopia in boys associated with bladder outlet obstruction.

PURPOSE: Ureteral ectopia is frequently associated with dysplasia of the associated renal segment in girls with ureteral duplication. However, single system ureteral ectopia is an uncommon anomaly more frequently noted in boys. We report on 6 boys with single system ureteral ectopia into the prostatic urethra above the verumontanum, who presented with radiological and clinical findings of bladder outlet obstruction. MATERIALS AND METHODS: Antenatal ultrasound in 3 boys demonstrated renal abnormalities and postnatal studies suggested the diagnosis of posterior urethral valve obstruction. Older boys presented with symptoms suggestive of bladder outlet obstruction. RESULTS: An ectopic ureter inserting into the prostatic urethra was noted in all 6 boys. The distal ureter was dilated elevating the bladder neck causing outlet obstruction. Surgical management consisted of nephrectomy and transurethral endoscopic incision of the distal ureter or nephroureterectomy with reconstruction of the prostatic urethra. In 2 younger boys voiding dysfunction with inability to empty developed. CONCLUSIONS: Single system ectopic ureters in boys may present with symptomatic and radiological findings resembling posterior urethral valves. Surgical treatment should include nephroureterectomy with reconstruction of the hypoplastic prostate. Some patients may have later voiding dysfunction.

Adolescent↗
PubMed1998

Surgery versus observation for managing obstructive grade 3 to 4 unilateral hydronephrosis: a report from the Society for Fetal Urology.

PURPOSE: The Society for Fetal Urology has undertaken the first multicenter prospective randomized study of high grade obstructive unilateral hydronephrosis to evaluate the natural history of untreated obstruction and compare it to the benefits of pyeloplasty. MATERIALS AND METHODS: Since 1991, infants with isolated unilateral Society for Fetal Urology grade 3 hydronephrosis and ipsilateral obstruction with greater than 40% differential renal function on well tempered renography were studied. Patients were randomly assigned to observation or pyeloplasty groups. Renal ultrasound and well tempered renography were performed biannually for 1 year and yearly thereafter. Crossover criteria for surgery included concurrent worsening of isotope washout and increasing grade of hydronephrosis or a greater than 10% point loss in percent differential renal function that was noted between studies. The end point of the study was the 3-year anniversary of randomization. RESULTS: A total of 32 infants from 10 centers were randomized equally to 2 groups. The starting grade of hydronephrosis and percent differential renal function were similar between the 2 groups. At 6 months and 1 year the grade of hydronephrosis was significantly reduced (p < 0.02) and well tempered renography was significantly more likely to demonstrate no obstruction (p < 0.03) in the surgical group compared with the observation group. The mean percent differential renal function remained stable and similar in both groups. Reduced hydronephrosis and resolution of obstruction in the surgery group persisted as a trend at the 2 and 3-year anniversaries. In the observation group 4 patients (25%) showed enough renal deterioration to qualify for crossover to surgery. CONCLUSIONS: Infant pyeloplasty significantly improved the grade of hydronephrosis and drainage pattern at 6 months and 1 year postoperatively, when compared with observation. Renal function stabilization was similar for either management approach. However, 25% of the patients satisfied objective criteria of status deterioration requiring pyeloplasty.

Cross-Over Studies↗
PubMed1998

The prenatal diagnosis of cloacal exstrophy.

PURPOSE: We assess and clarify diagnostic features for making the prenatal diagnosis of cloacal exstrophy. MATERIALS AND METHODS: We evaluated 9 patients born with cloacal exstrophy at our institutions (2 prospectively and 7 retrospectively) for diagnostic features on prenatal ultrasound studies. We also thoroughly reviewed the literature on 13 previous prenatally diagnosed cloacal exstrophy cases. Diagnostic criteria were assessed by combining the findings in our patients and those in previous reports. RESULTS: Of the 22 patients with prenatal ultrasound studies and cloacal exstrophy whom we analyzed 1 of our 9 and 2 in the literature had a cloacal membrane that persisted at 22 weeks of gestation. Major ultrasound criteria for diagnosing cloacal exstrophy prenatally are nonvisualization of the bladder, a large midline infraumbilical anterior wall defect or cystic anterior wall structure (persistent cloacal membrane), omphalocele and lumbosacral anomalies. Seven less frequent or minor criteria include lower extremity defects, renal anomalies, ascites, widened pubic arches, a narrow thorax, hydrocephalus and 1 umbilical artery. CONCLUSIONS: We propose major and minor criteria to assist in the prenatal diagnosis of cloacal exstrophy. Despite these major and minor criteria the certainty of establishing a prenatal diagnosis remains challenging. Persistence of the cloacal membrane beyond the first trimester in 1 patient was an exception to the classic concept of cloacal exstrophy embryogenesis. An accurate prenatal diagnosis requires validation of these criteria by further correlation of prenatal and postnatal observations.

Cloaca↗
PubMed1998

The clinician's approach to the management of headache.

Headache is a ubiquitous complaint, yet it is one that often elicits anxiety in both patients and physicians. When a patient presents with headache, the clinician must answer the following questions: (1) Is the headache "worrisome" (secondary to underlying disease)? (2) If the headache is benign, what type is it? (3) How is the acute headache best treated? and (4) How may future headaches be prevented? The following review is intended to aid primary care physicians in answering these questions.

Headache↗
PubMed1997

Management considerations for treating vesicoureteral reflux in children with solitary kidneys.

OBJECTIVES: To evaluate the management approach for vesicoureteral reflux (reflux) into a solitary kidney. METHODS: Outcomes of all children with solitary kidneys and reflux managed between 1981 and 1996 were reviewed. Solitary kidneys were documented by nuclear renography and ultrasonography; reflux was graded after cystography. Management consisted of observation and antimicrobial prophylaxis or surgery by ureteroneocystostomy or subureteric injection of polytetrafluoroethylene (STING). Follow-up ranged from 3 months to 14 years and included serial cystography, sonography, and serum creatinine measurement. RESULTS: Twenty-one patients with a median follow-up of 26 months were identified. Etiologies included contralateral renal agenesis (14 children), multicystic dysplastic kidney (5 children), or nonfunctioning ureteropelvic junction obstruction (2 children). Low-grade (I to II) reflux was identified in 6 children, and high grade (III to V) was identified in 15. Reflux resolved in 20 patients. Five children with low-grade reflux were managed without surgery and demonstrated reflux resolution after a mean of 20.5 months. Renal function deteriorated in only 1 child. Ureteroneocystostomy was performed in 13 children with grades III to V reflux, and STING was performed in 1 child with grade II reflux. Every surgical patient maintained stable renal function and was infection-free during a mean follow-up of 56 months. Management by observation in 2 children with grades IV to V reflux resulted in spontaneous resolution in one and stable grade IV in the other. CONCLUSIONS: Reflux into the solitary functioning kidney may be managed by the same strategies used to manage unilateral reflux in children with two normally functioning kidneys: low-grade reflux by observation/ chemoprophylaxis until spontaneous resolution occurs, and higher grades by surgery to protect renal function; however, chemoprophylaxis and serial imaging may be used until well-defined indications for surgery are satisfied. Renal function should be monitored diligently.

Child↗
PubMed1997

Captopril (an inhibitor of angiotensin converting enzyme) inhibits obstructive changes in the neonatal rabbit bladder.

OBJECTIVES: To investigate whether angiotensin II has a role in the regulation of bladder smooth muscle growth and function, we developed a model of bladder neck obstruction (BNO) in the neonatal rabbit and investigated the effect of captopril (angiotensin converting enzyme inhibitor) on the obstructive changes in the developing bladder. METHODS: Partial BNO was induced in a group of 2-day-old rabbits (n = 8) by placing a loose 2-0 silk ligature around the vesicourethral junction. A second group of rabbits subjected to the identical partial BNO procedure (n = 8) was given captopril (1 mg/kg/day). Twelve days postobstruction, bladders from these animals, along with paired controls (n = 8), were harvested and assayed for total protein, DNA, and collagen content. RESULTS: Partial BNO resulted in a 170% increase in wet weight (P < 0.05), 132% increase in protein/deoxyribonucleic acid (DNA) ratio (P < 0.05), 75% increase in total DNA (P < 0.05), and 115% increase in total collagen (P < 0.05). When compared with obstructed animals, captopril administration significantly inhibited the increase in total DNA (P < 0.05) and reduced the amount of total collagen (P = 0.054). Examination of histology specimens demonstrated that captopril inhibited the serosal hyperplasia and collagen deposition associated with obstruction. CONCLUSIONS: These data demonstrate that captopril partially inhibits the changes in the neonatal rabbit bladder associated with obstruction, supporting the hypothesis that angiotensin II is involved in the regulation of bladder smooth muscle growth and collagen production.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Urine levels of transforming growth factor-beta 1 in children with ureteropelvic junction obstruction.

OBJECTIVES: To determine if there are measurable quantities of transforming growth factor-beta 1 (TGF-beta 1) in the urine of children with either normal or pathologic conditions of the urinary tract, specifically vesicoureteral reflux (VUR) and ureteropelvic junction obstruction (UPJO). We also sought to determine if the urine TGF-beta level could distinguish between renal obstruction and no obstruction. METHODS: Preoperative bladder urine from consecutive patients undergoing pyeloplasty (UPJO group; n = 13), ureteral reimplantation (VUR group; n = 11), or circumcision/orchiopexy (control group; n = 19) as well as urine from the renal pelvis of the UPJO group was collected. The urine level of TGF-beta 1 was measured using a quantitative sandwich enzyme immunoassay technique. RESULTS: Urine level of TGF-beta 1 was detected in each group: control (26.6 +/- 6.3 pg/mL), reflux (22.1 +/- 9.6), UPJO-pelvic urine (82.4 +/- 19.3), UPJO-bladder urine (31.2 +/- 8.2). The urine TGF-beta 1 concentration in pelvic urine in the UPJO group was significantly higher than that in bladder urine in children in the UPJO group (p = 0.03). TGF-beta 1 concentrations were similar from the bladder of children in all three study groups (p = NS). CONCLUSIONS: Urine TGF-beta 1 is detectable in children with normal and pathologic urinary tracts. The level of this urine marker is elevated in the renal pelvis of children with UPJO compared to the level in the bladder of either obstructed or nonobstructed upper urinary tracts.

Biomarkers↗
PubMed1997

The influence of surgical approach and intraoperative venography on successful varicocelectomy in adolescents.

PURPOSE: We evaluated the importance of intraoperative venography and surgical approach on varicocele recurrence after surgical varicocelectomy in male adolescents. MATERIALS AND METHODS: The analysis was done using local data and composite data from the literature. We reviewed the records of patients undergoing varicocele ligation between 1986 and 1995 at our institution. Data were stratified by surgical approach and performance of venography, and compared by cross table analysis. Data were then compiled from the literature from series that included cases stratified according to surgical approach and/or performance of venography. The impact of these parameters on recurrence rates was assessed by computing success rates and cross table analysis. RESULTS: At our institution 33 boys underwent ligation via a suprainguinal (27) or inguinal (8) approach. Intraoperative post-ligation venography was performed in 16 cases and omitted in 19. Neither surgical approach nor performance of venography influenced the recurrence rate in these patients (not statistically significant). Similarly, venography did not affect the recurrence rate after stratification by surgical approach (not significant). The overall success rate was 97% (34 of 35 cases). These data were added to those of 3 published studies, totaling 252 varicoceles with comparable groupings. Mean success rate after a suprainguinal and inguinal approach was 95.6 (93.2 to 97.4) and 88.3% (82.7 to 100%), respectively. Recurrence tended to be less common after a suprainguinal than an inguinal approach (p = 0.06). Post-ligation venography did not statistically affect the success rate after stratification according to surgical approach but it was associated with a higher success rate when performed with the inguinal approach. CONCLUSIONS: Irrespective of the performance of venography, the suprainguinal surgical approach yields higher success rates than the inguinal approach to varicoceles in adolescents. Post-ligation intraoperative venography fails to affect significantly the success of varicocele ligation but it may be useful during an inguinal approach.

Adolescent↗
PubMed1996

Isolated fetal pyelectasis: assessment of risk for postnatal uropathy and Down syndrome.

Eight-two consecutive fetuses with ultrasound evidence of isolated pyelectasis (defined as dilation in the antero-posterior renal pelvic dimension of > or = 4 mm) were prospectively followed to determine the risk of postnatal uropathy and Down syndrome. In 98 (60%) kidneys, isolated pyelectasis was shown to be the first manifestation of a pathophysiological process that evolved into a gamut of postnatal uropathies (defined as urological conditions requiring remedial surgery or extended medical surveillance). Data quantifying the risk for postnatal uropathy in fetuses with varying degrees of isolated pyelectasis, at different gestational ages, are presented in figure format to facilitate prenatal counselling. Bivariate analysis showed that the evolution of isolated pyelectasis to uropathy was statistically significant when in utero progression was noted or in conjunction with other findings including contralateral pyelectasis (p < 0.01), male gender (p < 0.01) and increased kidney length (p < 0.001). Importantly, 55% of the infants requiring corrective surgery demonstrated in utero progression of pyelectasis (p < 0.002). Serial ultrasound examinations were necessary to evaluate progression or regression in the extent of pyelectasis. Finally, isolated pyelectasis was associated with an increase risk for Down syndrome, beginning at maternal age of 31 years, in the interval of 16-20 week's gestation.

Adult↗
PubMed1996

Angiotensin II and basic fibroblast growth factor induce neonatal bladder stromal cell mitogenesis.

PURPOSE: Our aims were to establish primary stromal cell cultures from the neonatal rabbit bladder and investigate the potential mitogenic effects of angiotensin II and basic fibroblast growth factor on these cells. MATERIALS AND METHODS: Primary bladder stromal cell cultures were obtained from 3-day-old rabbits, plated at a density of 3 x 10(4) cells per ml. and allowed to grow for 24 hours. Subconfluent cells were growth arrested in serum deficient (0.25% newborn calf serum) or serum-free media for 24 hours and then stimulated with 10(-7) M. angiotensin II or 10 ng./ml. basic fibroblast growth factor for an additional 48 hours. Cell counts and [3H] thymidine incorporation were done to measure cellular proliferation and deoxyribonucleic acid synthesis. RESULTS: Angiotensin II and basic fibroblast growth factor each stimulated neonatal bladder stromal cell proliferation and [3H] thymidine incorporation under serum deficient conditions. Angiotensin II provoked an average 26% increase in cell number (p < 0.01) and 35% increase in [3H] thymidine incorporation (p < 0.01) compared to control values. Basic fibroblast growth factor was an even more potent mitogen with a 47% increase in cell number (p < 0.01) and 180% increase in [3H] thymidine incorporation (p < 0.01) compared to controls. In contrast, angiotensin II and basic fibroblast growth factor each failed to have significant stimulatory effects under serum-free conditions. CONCLUSIONS: Angiotensin II and basic fibroblast growth factor induce a mitogenic response to neonatal bladder stromal cells in vitro. These mitogenic effects require the presence of serum factors. Whether angiotensin II and basic fibroblast growth factor are involved in the in vivo regulation of bladder growth associated with obstructive uropathy requires further investigation.

Angiotensin II↗
PubMed1996

TGF-beta mRNA expression in the renal pelvis after experimental and clinical ureteropelvic junction obstruction.

PURPOSE: The renal parenchymal expression of transforming growth factor-beta (TGF-beta) is increased in experimental obstructive uropathy. To better understand the pathophysiology of hydronephrosis, we pursued this observation by determining if the expression of TGF-beta is also increased in the obstructed renal pelvis. MATERIALS AND METHODS: The expression of TGF-beta mRNA was evaluated in experimental and clinical ureteropelvic junction obstruction by reverse transcriptase polymerase chain reaction (RT-PCR). Southern blot analysis with labeled human cDNA probes for TGF-beta was then done to verify the results. RESULTS: Experimentally, pelves subjected to ureteral constriction showed significantly higher TGF-beta mRNA expression than normals. After reversal of obstruction, the expression of TGF-beta remained significantly higher than normals but was not different from pelves with ongoing obstruction. Clinically, there was a significantly higher level of TGF-beta mRNA expression in obstructed pelves than in nonobstructed ureters. High levels of TGF-beta mRNA expression correlated significantly with good clinical outcome, good renal function, muscle hypertrophy and acute onset of obstruction. CONCLUSIONS: There is increased TGF-beta mRNA expression in the renal pelvis following clinical and experimental ureteropelvic junction obstruction. These data implicate TGF-beta in the adaptive molecular responses that increase muscle and collagen elaboration seen in hydronephrosis.

Animals↗
PubMed1994

Outcome of nonspecific hydronephrosis in the infant: a report from the Registry of the Society for Fetal Urology.

Since 1988 the Society for Fetal Urology has worked to evaluate if there is consensus on management of infants with nonspecific hydronephrosis. Initially, multicenter agreement on the criteria to grade hydronephrosis and method of diuretic renography were developed to promote similarities in how infant kidneys with nonspecific hydronephrosis were profiled for grade (0 to 4), per cent differential function by diuretic renography and drainage response by diuretic renography (obstructed, not obstructed or indeterminate). Between 1989 and 1992 a total of 33 pediatric urologists from 21 cities registered 464 cases (582 kidneys) of hydronephrosis. Of the cases 275 (59%) were managed by observation and 189 (41%) were treated surgically. The operated kidneys showed profiles (hydronephrosis grade 3 or greater and diuretic renography obstructed) that were significantly different from the profiles of observed kidneys (hydronephrosis grade 2 or less and diuretic renography no obstruction) (p < 0.001 each). Six months postoperatively the mean grade of hydronephrosis (1.8) and diuretic renography diagnosis (no obstruction) were significantly better than they were preoperatively (p < 0.001 each). In addition, postoperatively the mean grade of hydronephrosis, diuretic renography diagnosis and per cent differential function were similar to age matched observed kidneys. We conclude that when radiographic tests are done similarly, there is consensus in the management of infant hydronephrosis by surgery or observation.

Databases, Factual↗
PubMed1993

Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology.

The Society for Fetal Urology (SFU) was founded in 1988 to study the postnatal evolution of prenatally detected anomalies of the urinary tract by following those neonates whose prenatal studies have brought them to medical attention while asymptomatic. The SFU has attempted to standardize methods of performing and grading the ultrasound and radionuclide examinations in this population. A system to grade upper tract dilatation or hydronephrosis (HN) imaged by ultrasound has been developed and is being used by SFU members in 36 institutions. The appearance of the calices, renal pelvis and renal parenchyma are key in determining the grade of HN and are illustrated in this article.

Female↗
PubMed1993

Use of kidney internal splint/stent (KISS) catheter in urinary diversion after pyeloplasty.

We report on the use of a new catheter, the kidney internal splint/stent (KISS), to facilitate renal urine drainage following pyeloplasty. The catheter combines the desirable qualities of nephrostomy tube diversion, anastomotic stent, and trocar placement in a single tube. The special construction of its lumen diminishes the likelihood of obstructed drainage. Our experience using the KISS catheter with 31 patients undergoing pyeloplasty shows it provides effective internal and external urinary diversion.

Adolescent↗
PubMed1993

Does early pyeloplasty really avert loss of renal function? A retrospective review.

We reviewed 75 cases of isolated, unilateral pediatric ureteropelvic junction obstruction and 167 diuretic radionuclide renograms performed during the last 8 years. Differential function of the affected kidney was calculated using scintillation count data at 1 and 3 minutes, and the area under the renogram curve between 1 and 3 minutes. There was no significant difference among the 3 measures of per cent differential function for a given patient. Per cent differential function on the first renogram preoperatively neither declined as age at presentation advanced nor did it vary according to the clinical presentation. Similarly, the changes in postoperative per cent differential function were unaffected by the age at initial presentation, manner of presentation, occurrence of postoperative complications or the surgeon. These data do not support the concept that pyeloplasty for the isolated, unilateral ureteropelvic junction obstruction should be performed early to avert loss of renal function.

Adolescent↗
PubMed1993

Response of the newborn ureteropelvic junction complex to induced and later reversed partial ureteral obstruction in the rabbit model.

The clinical controversy regarding the timing of surgery for asymptomatic newborns with obstructed hydronephrosis was addressed using a model of reversible partial ureteral obstruction in the newborn rabbit. The histomorphometric changes in the ureteropelvic junction complex (for example, pelvis, ureteropelvic junction and upper ureter) and kidney in 44 normal cases were determined and compared with the effects of 47 cases of ongoing partial obstruction and timed reversal of partial obstruction at 1 week in 9 cases, at 2 weeks in 10 or at 4 weeks in 10 (end of the study at age 8 weeks). After partial obstruction hydronephrosis appeared by 1 week postoperatively. There were progressive increases in the thickness of the lamina muscularis and mass index of smooth muscle and collagen (all p < 0.001). However, since the per cent surface area of smooth muscle did not change significantly in comparison to normal, there was disproportionately more collagen. For reversals at 1 week the muscle and collagen in the lamina muscularis were not significantly different from normal. For reversals at 2 weeks the mass index of collagen was greater than normal (p < 0.05) and reversal at 1 week (p < 0.05). For reversals at 4 weeks the lamina muscularis was thicker, and the mass index of collagen and muscle was greater than the earlier reversal groups and normal (all p < 0.05). In conclusion, partial ureteral obstruction causes progressive thickening of the lamina muscularis by collagen and muscle with a disproportionately greater increase in collagen than muscle. The earlier the obstruction can be reversed, the more normal is the ureteropelvic junction complex histology. The functional significance of these changes needs to be determined.

Animals↗