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Biomedical subjects

J Mandell

Publications and source records attributed to J Mandell.

At least 37 records · Page 2Linked to original sources
PubMed1996

Reconstructive options in genitourinary rhabdomyosarcoma.

PURPOSE: We attempted to develop a rational and consistent scheme for surgical reconstruction in patients with genitourinary rhabdomyosarcoma. MATERIALS AND METHODS: We reviewed the records of 35 patients with resectable genitourinary rhabdomyosarcoma treated from 1970 to 1993. RESULTS: Primary sites included bladder in 11 cases, prostate in 13, vagina/uterus in 9 and pelvic tumors of uncertain origin in 2. A total of 33 patients underwent surgery, including partial and radical cystectomy in 17 (bowel conduit diversion in 10, continent urinary diversion in 6 and ureterosigmoidostomy in 1). Overall 30 of the 33 surgical patients are free of disease 4 months to 24 years after diagnosis. CONCLUSIONS: A nonrefluxing colon conduit is appropriate at cystectomy. Continent diversion fashioned from the original conduit may be planned as the patient achieves a durable disease-free status.

Adolescent↗
PubMed1995

Fetal suprarenal masses: sonographic appearance and differential diagnosis.

We present eight cases of suprarenal masses detected sonographically in fetuses of 20-41 weeks. The appearances of the masses included hyperechoic (n = 2, both pulmonary sequestrations), solid isoechoic (n = 1, a neuroblastoma), purely cystic (n = 3, two neuroblastomas, one enteric cyst) and mixed or complex (n = 2, one neuroblastoma and one renal cyst). Three of the fetuses with neuroblastoma had normal scans in the second trimester, and in all four the neuroblastomas were detected after 36 weeks. This study demonstrates the differential diagnosis of suprarenal masses in fetuses. Neuroblastomas can have a solid, purely cystic or complex sonographic appearance. Although not all suprarenal masses are neuroblastomas, the newborn with a prenatally detected suprarenal mass should be evaluated for the possibility of a neuroblastoma, since early diagnosis of this malignancy can be curative.

Adrenal Gland Neoplasms↗
PubMed1995

Prenatally diagnosed bilateral hyperechoic kidneys with normal amniotic fluid: postnatal outcome.

We evaluated a subset of infants with bilateral markedly hyperechoic "bright" kidneys noted prenatally in association with normal amniotic fluid volume during gestation. Prenatal ultrasound showed increased renal parenchymal echogenicity bilaterally with preservation of the medullary pyramid architecture. These children were followed for up to 3 years to determine potential changes in the sonographic appearance of the echogenic renal parenchyma and to assess renal function. In 3 years 8 cases of bilateral hyperechoic fetal kidneys were identified. During postnatal followup renal echogenicity resolved in 4 cases, diminished in 1 and remained the same in 3. The serum creatinine and electrolytes were normal in all cases followed for more than 3 months. Other renal findings included vesicoureteral reflux in 2 of 7 cases, mild pelvic ectasia in 1 and tiny medullary calcifications in 1. The specific etiology of increased echogenicity is unknown, although 1 infant appeared to have a form of autosomal recessive disease with liver hyperechogenicity as well. We conclude that fetuses with bilateral hyperechoic kidneys associated with normal amniotic fluid volume have a favorable outcome. Ultrasonographic finding of marked parenchymal hyperechogenicity appears to improve with time; in our experience renal function is normal and the infants thrive. Continued followup is necessary to determine the long-term natural history of this phenomenon, as is subsequent prenatal and postnatal evaluation of future siblings to assess genetic risk.

Amniotic Fluid↗
PubMed1995

Comparative urodynamics of appendiceal and ureteral Mitrofanoff conduits in children.

We report the cystometric and conduit pressure profilometric findings of 20 children for whom the Mitrofanoff principle was applied to the construction of 21 continent catheterizable urinary conduits. Mitrofanoff conduits were fashioned from ureter in 10 cases, appendix in 8, ileum in 1, stomach in 1 and a combination appendix and ureter in 1. Conduit pressure profiles showed that functional profile length correlated strongly with the static profile maximal Mitrofanoff closure pressure (p = 0.04) and dynamic profile maximal Mitrofanoff closure pressure (p = 0.02). There was a statistically significant difference between clinical continence rates for children above and below the functional profile length threshold of 2.0 cm. (p = 0.05). The zone of continence corresponded to the region of the conduit intramural tunnel. Only 2 of 21 conduits were incontinent but both were constructed with ureters implanted into bowel reservoirs. Compared to appendiceal conduits, ureteral conduits had a lower functional profile length (p < 0.01) and static profile maximal Mitrofanoff closure pressure (p < 0.01), indicating a possible advantage to the use of the appendix.

Adolescent↗
PubMed1995

The long-term urological response of neonates with myelodysplasia treated proactively with intermittent catheterization and anticholinergic therapy.

PURPOSE: Urinary tract management in children with myelodysplasia is controversial. Some advocate observation alone, while others believe that the prophylactic institution of intermittent catheterization and anticholinergic therapy may help to prevent deterioration. MATERIALS AND METHODS: A nonrandomized prospective study was instituted to compare the urological outcomes of a cohort of children who were at risk for urological deterioration on the basis of bladder-sphincter dyssynergia and/or high filling or voiding pressures. Those at risk were observed until deterioration occurred, or were placed on prophylactic intermittent catheterization with or without anticholinergic medication. RESULTS: Of 44 children at risk 35 followed by observation alone had urinary tract deterioration, whereas only 3 of 20 at risk treated with prophylactic intermittent catheterization had deterioration with time. CONCLUSIONS: Proactive bladder treatment significantly reduced the incidence of upper urinary tract deterioration and need for surgical intervention.

Cholinergic Antagonists↗
PubMed1995

Prenatal sonographic detection of genital malformations.

Postnatal clinical and pathological correlation of sonographically identified genital malformations in 17 fetuses was undertaken to determine the outcome of these findings. Diagnoses confirmed at autopsy or by postnatal examination and surgery included male (XY) pseudohermaphroditism in 2 cases, hypospadias with chordee in 3, microphallus in 2, cloacal anomaly in 2, congenital adrenal hyperplasia in 3, penoscrotal transposition in 2, intra-abdominal testes in 1, megalourethra in 1 and cloacal exstrophy variant in 1. Additional abnormalities included congenital heart defects, cleft palate, and renal, anorectal, cranial and cerebral malformations. Four fetuses with a sonographically abnormal appearing phallus were found to have an endocrine disorder (3 congenital adrenal hyperplasia and 1 panhypopituitarism). Outcomes included 2 abortions and 1 neonatal death with the remaining neonates undergoing medical and reconstructive treatment. Prenatal detection of genital abnormalities can be helpful in evaluating those fetuses with severe multi-system anomalies as well as lesions more amenable to correlation in the neonatal period. Detection is particularly important in neonates with endocrine disorders, and complex genitourinary and anorectal malformations.

Female↗
PubMed1995

Expression of cell growth regulated genes in the fetal kidney: relevance to in utero obstruction.

Previous studies of fetal urinary tract obstruction (bladder outlet obstruction and ureteral obstruction) in lambs have shown that obstructions created relatively early in gestation (4/10 to 6/10 term) can significantly affect growth of the developing kidney. This suggests that urinary tract obstruction in utero can alter normal mechanisms of kidney growth. However, a mechanism for these effects has not yet been proposed. In this study we have used mRNA expression analysis to characterize the temporal sequence of expression of several growth-regulated genes during normal ovine kidney development. The purpose of this study was to test the hypothesis that early obstructions, such as those believed to arise in congenital obstructive uropathy in humans, might have a disproportionate effect on hyperplastic growth if the cellular growth fraction (percent of cells in the organ undergoing DNA synthesis) was greater in the second trimester than in the last. Northern blot analysis of the cell cycle-dependent genes histone H3, c-myc and ornithine decarboxylase (ODC) indicated a progressive, gradual decline in cellular proliferation in the kidney from approximately 60 to 135 days (4/10 term to term) gestation, as evidenced by decreases in the respective mRNA levels. The greatest levels of cell proliferation occurred near the midpoint of gestation. This indirect measurement of decline in cellular growth fraction was reflected in direct measurements of change in relative kidney weight. To test whether this decline in mRNA levels occurs widely among genes expressed in the fetal kidney during this period, relative expression levels of more than 300 anonymous mRNA transcripts were evaluated by differential display analysis. This method showed that genes whose expression patterns resembled the growth-regulated genes constituted less than 5% of the expressed mRNAs identified. These data indicate that intrauterine urinary tract obstructions that arise at or near the midpoint of gestation coincide with the highest rates of cell proliferation occurring in the second and third trimesters and, therefore, might adversely affect mechanisms of cell proliferation.

Animals↗
PubMed1994

Infrequent mutation of the WT1 gene in 77 Wilms' Tumors.

Homozygous deletions in Wilms' tumor DNA have been a key step in the identification and isolation of the WT1 gene. Several additional loci are also postulated to contribute to Wilms' tumor formation. To assess the frequency of WT1 alterations we have analyzed the WT1 locus in a panel of 77 Wilms' tumors. Eight tumors showed evidence for large deletions of several hundred or thousand kilobasepairs of DNA, some of which were also cytogenetically detected. Additional intragenic mutations were detected using more sensitive SSCP analyses to scan all 10 WT1 exons. Most of these result in premature stop codons or missense mutations that inactivate the remaining WT1 allele. The overall frequency of WT1 alterations detected with these methods is less than 15%. While some mutations may not be detectable with the methods employed, our results suggest that direct alterations of the WT1 gene are present in only a small fraction of Wilms' tumors. Thus, mutations at other Wilms' tumor loci or disturbance of interactions between these genes likely play an important role in Wilms' tumor development.

Amino Acid Sequence↗
PubMed1994

Prenatal diagnosis of cloacal malformation.

Cloacal malformation is a rare abnormality, occurring only in females and characterized by a direct communication between the gastrointestinal, urinary, and genital structures resulting in a single perineal opening. We report 2 cases of prenatal diagnosis of this condition with a varied ultrasonic appearance including fetal ascites, cystic retrovesical mass, ambiguous genitalia, nonvisualization of the bladder, and oligohydramnios.

Adult↗
PubMed1994

Meatal based hypospadias repair with the use of a dorsal subcutaneous flap to prevent urethrocutaneous fistula.

A technique using a dorsal dartos subcutaneous flap to wrap the neourethra after hypospadias repair is described. This method was used in a series of 204 meatal based repairs. Catheter drainage or diversion was not performed in any nontoilet trained child. The procedure was done on an ambulatory or 1-night hospitalization basis. No patient had a urethrocutaneous fistula. The additional covering of the neourethra with the dorsal subcutaneous flap appears to be excellent for avoiding the development of urethrocutaneous fistulas in patients with distal hypospadias.

Adolescent↗
PubMed1994

Management of severe hypospadias with a 2-stage repair.

From 1986 to 1993 we treated 1,437 children with hypospadias of whom 58 had scrotal or perineal hypospadias with severe chordee and a small phallus. These patients underwent a 2-stage surgical repair. The first stage of the procedure included correction of the chordee and advancement of preputial flaps ventrally and distally to the superior aspect of the glans. After 6 to 12 months the second stage of the procedure was performed using the previously transferred preputial skin to reconstruct the glans and urethra. A second layer of subcutaneous tissue or tunica vaginalis was used in several instances. A penile nerve block and a transparent biomembrane dressing (Tegaderm) allowed for early postoperative mobilization. Excellent functional and cosmetic results were achieved. There is a subset of patients with severe proximal hypospadias, chordee and a small phallus who may benefit best from a 2-stage procedure. In these children a 2-stage repair allows for a better cosmetic appearance and a lower complication rate than a 1-stage repair with a free or vascularized graft.

Child↗
PubMed1994

Prenatal findings associated with a unilateral nonfunctioning or absent kidney.

Prenatal findings in infants who were postnatally found to have a unilaterally nonfunctioning cystic, dysplastic or absent kidney were evaluated to understand better the prenatal pathophysiology of these conditions. Of the 38 cases in which prenatal and postnatal renal imaging studies were done fetal renal conditions leading to postnatal dysplasia or absence included small echogenic kidneys in 3, typical multicystic dysplasia in 30, obstructive uropathy in 4 and perinephric urinoma in 1. Abnormalities were noted on postnatal imaging in 30% of the contralateral kidneys. Vesicoureteral reflux was the most commonly identified abnormality, occurring in 23% of the cases.

Female↗
PubMed1994

Urinary levels of the renal tubular enzyme N-acetyl-beta-D-glucosaminidase in unilateral obstructive uropathy.

Elevated urinary levels of the renal tubular enzyme, N-acetyl-beta-D-glucosaminidase (NAG), have been shown to be associated with reversible tubular damage and, therefore, may serve as an indicator of tubular damage in the setting of presumed obstruction uropathy. This study compares urinary NAG levels in children with apparent upper tract obstruction with normal children to assess the sensitivity of this assay for the detection of possible renal tubular damage. The study included 40 children 3 weeks to 16 years old with unilateral ureteropelvic junction obstruction (30) or primary obstructive megaureter (10). Urine was obtained from the bladder in all children and from the renal pelvis or ureter in 30 patients at surgery. Pelvic and ureteral urinary NAG levels were consistently higher than bladder levels. In patients with ureteropelvic junction obstruction NAG levels were 7 times higher than normal (76 units per mg., p < 0.0001) and 3 times higher than normal in patients with obstructive megaureter (29 units per mg., p < 0.001). The mean bladder urinary NAG levels in patients with ureteropelvic junction obstruction (17.6 units per mg. creatinine, standard error of mean 2.01, p < 0.001) and megaureters (19.2 units per mg. creatinine, standard error of mean 3.6, p < 0.049) were elevated above control patients (10.6 units per mg. creatinine, standard error of mean 1.02). Elevated urinary NAG levels in the renal pelvis, ureter and bladder may be helpful in identifying upper tract obstruction, which if left untreated, might cause progressive renal deterioration.

Acetylglucosaminidase↗
PubMed1994

Laparoscopic evaluation of the nonpalpable tests: a prospective assessment of accuracy.

To assess diagnostic accuracy, laparoscopy and surgical exploration were prospectively performed in 104 children with 126 nonpalpable testes. Laparoscopic localization of the testis was correct in 90% (114 of 126 testes) and was nondiagnostic in 8% largely due to preperitoneal insufflation. No surgical complications occurred. Using the criteria of blind-ending vas deferens and spermatic vessels as diagnostic of an intra-abdominal vanishing testis, the accuracy of diagnosis was 100% but the inability to identify either vas or vessels was associated with intra-abdominal testes in 2 of 3 cases. Identification of canalicular vas deferens and spermatic vessels was associated with testes in 36 of 75 cases (48%). Bilateral nonpalpable testes were significantly less likely to have an absent testes (5%) than a unilateral nonpalpable testis (59%), suggesting the possibility of different pathophysiological mechanisms in those entities. Diagnosis and surgical management of nonpalpable testes were directly impacted by laparoscopy in 42 of 117 testes (36%) by identifying intra-abdominal vanishing testis, the location of an intra-abdominal testes or the need for retroperitoneal exploration when vas deferens and spermatic vessels were not found. Accurate knowledge of testis location in 97% of the testes facilitated development of an appropriate surgical strategy (that is laparoscopic/laparoscopic assisted versus open procedure).

Adolescent↗
PubMed1994

Prenatal and postnatal findings in monochorionic, monoamniotic twins discordant for bilateral renal agenesis-dysgenesis (perinatal lethal renal disease).

We report on a male twin born with no functional renal tissue and without the extrarenal manifestations of Potter facies, skin changes, club feet and pulmonary hypoplasia. The monoamniotic co-twin had normal renal function, thereby maintaining sufficient amniotic fluid to avoid the classic presentation of Potter's syndrome. Prenatal diagnosis of this condition allowed prompt confirmation of these findings and support for the parents without unnecessary intervention. This experiment of nature demonstrates the necessity of normal renal function in the maintenance of amniotic fluid and its relationship to the proper development of the pulmonary and integumentary systems.

Adult↗