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David A Bloom

Publications and source records attributed to David A Bloom.

At least 37 records · Page 2Linked to original sources
PubMed2004

What is the rate of spontaneous testicular descent in infants with cryptorchidism?

PURPOSE: It has been speculated that late spontaneous testicular descent occurs in more than 70% of newborns with cryptorchidism. Based on this belief, the decision for orchiopexy is often deferred during infancy. We reviewed our 10-year experience of treating infants with cryptorchidism to document the rate of spontaneous testicular descent. MATERIALS AND METHODS: A total of 1,235 patients with cryptorchidism were referred to our pediatric urology clinic between 1990 and 2000. Of these patients 278 presented before age 12 months. The medical records were reviewed explicitly to document the rate of spontaneous testicular descent. RESULTS: Spontaneous descent occurred in only 6.9% of patients with cryptorchidism reexamined at age 1 year or beyond. All patients with eventual spontaneous descent initially presented by age 6 months. Of those initially presenting beyond age 6 months no patient had spontaneous testicular descent. CONCLUSIONS: Contrary to previous belief, spontaneous testicular descent is uncommon in infants with cryptorchidism and is rare beyond age 6 months.

Cryptorchidism↗
PubMed2004

What is the fate of the refluxing contralateral kidney in children with multicystic dysplastic kidney?

PURPOSE: We clarify the natural history of contralateral vesicoureteral reflux (VUR) in children with multicystic dysplastic kidney (MCDK), including its impact on long-term renal growth. MATERIALS AND METHODS: We performed a retrospective cohort study of 75 patients with MCDK. The primary outcomes were resolution of contralateral VUR and long-term renal growth. The Kaplan-Meier method was used to compare time to spontaneous resolution based on VUR grade. Mixed regression models were used to compare longitudinal changes in sonographic renal length. RESULTS: Contralateral VUR was present in 19 of the 75 cases (26.4%) and was low grade (I-II) in 9. After a median followup of 4.4 years spontaneous resolution was more common in patients with grades I and II (89%) versus grades III and IV VUR (50%) (p = 0.14). Median time to resolution did not differ by grade (20.1 vs 31.3 months, p = 0.3). One child underwent ureteral reimplantation and no patients had hypertension or renal insufficiency. Mixed regression analysis demonstrated no significant difference in the annual increase in renal length based on VUR status (p >0.20). CONCLUSIONS: In the largest series to date of patients with MCDK and contralateral VUR we found that spontaneous resolution in a relatively short period can be anticipated for most children. Furthermore, VUR is not a significant threat to the growth of the solitary renal unit in the first few years of life.

Cohort Studies↗
PubMed2004

Retroperitoneal malignant peripheral nerve sheath tumor: evaluation with serial FDG-PET.

Retroperitoneal malignant peripheral nerve sheath tumor (MPNST), a rare type of neurogenic tumor, was diagnosed in a 14-year-old girl with a history of neurofibromatosis type 1 (NF1). Immunochemistry demonstrated spindle cells positive for S-100 protein. The patient had multiple tumor recurrences and she was evaluated with serial F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). A tumor in the right iliac wing showed increased FDG uptake on PET. FDG-PET played an important role in therapy planning and subsequent follow up. This case emphasizes the important role FDG-PET could play in the staging, restaging, and posttherapy follow up of MPNST.

Adolescent↗
PubMed2003

Phosphorylation of Nrf2 at Ser40 by protein kinase C in response to antioxidants leads to the release of Nrf2 from INrf2, but is not required for Nrf2 stabilization/accumulation in the nucleus and transcriptional activation of antioxidant response element-mediated NAD(P)H:quinone oxidoreductase-1 gene expression.

The antioxidant response element (ARE) and transcription factor Nrf2 regulate basal expression and antioxidant induction of NAD(P)H:quinone oxidoreductase-1 (NQO1) and other detoxifying genes. Under normal conditions, Nrf2 is targeted for proteasomal degradation by INrf2. Oxidative stress causes release of Nrf2 from INrf2. Nrf2 translocates to the nucleus, binds to the ARE, and activates gene expression. In this study, we demonstrate that protein kinase C (PKC) plays a significant role in the regulation of ARE-mediated NQO1 gene expression and induction in response to t-butylhydroquinone. Treatment of HepG2 cells with the PKC inhibitors staurosporine and calphostin C repressed ARE-mediated induction of a luciferase reporter as well as that of the endogenous NQO1 gene. Similar experiments with inhibitors of MEK/ERK, p38, phosphatidylinositol 3-kinase, and tyrosine kinases failed to repress ARE-mediated gene expression. The PKC inhibitor staurosporine blocked the nuclear translocation of Nrf2, suggesting that Nrf2 might be the target for PKC regulation. A Prosite search revealed the presence of seven putative PKC sites in mouse Nrf2. The PKC site at Ser40 is conserved among species and lies in the Neh2 domain, which interacts with INrf2. We demonstrate that phosphorylation of Ser40 is necessary for Nrf2 release from INrf2, but is not required for Nrf2 stabilization/accumulation in the nucleus and transcriptional activation of ARE-mediated NQO1 gene expression. A peptide that competes with endogenous Nrf2 for INrf2 binding was able to induce ARE activity more effectively than t-butylhydroquinone, and Nrf2 that accumulated in the nucleus as a result was not phosphorylated.

Antioxidants↗
PubMed2003

Congenital piriform fossa sinus tract presenting as an asymptomatic neck mass in an infant.

BACKGROUND: A 5-month-old girl with an asymptomatic left-sided neck mass was demonstrated by ultrasound and upper gastrointestinal series (UGI), and confirmed at surgery, to have a congenital piriform fossa sinus tract (CPFST) that communicated with an intrathyroidal cyst. OBJECTIVE: To demonstrate a case of CPFST presenting as an asymptomatic neck mass. Nearly all cases of CPFST present with infection or pain, making this case unique. MATERIALS AND METHODS: Case report and review of the literature. CONCLUSIONS: CPFST with an associated cyst should be added to the differential diagnosis of asymptomatic cystic neck masses in infants, especially if the cyst is intrathyroidal by ultrasound.

Branchial Region↗
PubMed2003

The cremasteric reflex: a useful but imperfect sign in testicular torsion.

The cremaster reflex has been reported to be absent in 100% of cases of testicular torsion, making it a useful sign in this difficult diagnosis. The authors report a case of surgically confirmed testicular torsion in which the cremasteric reflex clearly was present at presentation. The background of this sign and its utility in the evaluation of the acute scrotum are discussed.

Child, Preschool↗
PubMed2003

Pediatric renal pelvic fullness: an ultrasonographic dilemma.

PURPOSE: We conducted a prospective study to define normal renal pelvic size in children. MATERIALS AND METHODS: Institutional Review Board approved consent was obtained to perform renal ultrasound during excretory urography (IVP) scheduled for medical management. Mean patient age (17 females, 11 males) was 5.2 years. Renal ultrasound was conducted concurrent with 10-minute IVP. RESULTS: Fifty kidneys were imaged with 51 collecting systems. IVP defined 44 collecting systems as normal. Mean anteroposterior pelvic diameter on sonography for these 44 systems was 3.3 mm. One normal collecting system on IVP had a diameter greater than 10 mm on ultrasound (14 mm). No sonographic caliceal dilatation was seen in any kidney appearing normal on IVP. The 7 dilated systems on IVP had a mean ultrasound diameter of 17.1 mm. Two dilated collecting systems smaller than 10 mm in diameter on sonography had caliceal distention on ultrasound. CONCLUSIONS: Normal renal pelvis threshold diameter was 10 mm in asymptomatic children. We recommend further evaluation in children with caliceal dilatation and/or dilatation of the anteroposterior renal pelvis greater than 10 mm. Using these criteria, no system appearing abnormal on IVP would have been missed.

Adolescent↗
PubMed2003

Temporary perineal urethrostomy for external sphincter dilation in a male patient with high risk myelomeningocele.

PURPOSE: We describe our use of perineal urethrostomy to facilitate serial external sphincter dilations in a male child with high risk myelomeningocele. MATERIALS AND METHODS: A 5-month-old boy with lumbar myelomeningocele presented with poor bladder compliance, increased detrusor leak point pressure and high grade vesicoureteral reflux. Urodynamic parameters failed to improve with clean intermittent catheterization and anticholinergic therapy. Given the persistent risk to the upper urinary tract, perineal urethrostomy was performed to facilitate external sphincter dilation in a serial fashion. RESULTS: The patient underwent 2 aggressive external sphincter dilations (30Fr) under direct vision. The second dilation was performed in the outpatient clinic without anesthesia. Subsequent cystometrographic evaluation revealed dramatic improvement in bladder storage properties with improved compliance and a safe detrusor leak point pressure. Moreover, followup imaging demonstrated complete resolution of vesicoureteral reflux. CONCLUSIONS: Creation and maintenance of perineal urethrostomy is a valuable innovation in the treatment of some boys with high risk myelomeningocele. This easily reversible diversion allows aggressive, sequential external sphincter dilation and produces substantial improvements in bladder storage properties.

Dilatation↗
PubMed2002

Non-contrast thin-section helical CT of urinary tract calculi in children.

BACKGROUND: Non-contrast thin-section helical CT has gained acceptance for the diagnosis of urinary tract calculi in adults, but experience with the technique in children is limited. PURPOSE: To evaluate the utility of non-contrast thin section helical CT for the diagnosis of urinary tract calculi in children. MATERIALS AND METHODS: Radiology databases at three pediatric institutions were searched to identify all pediatric patients evaluated by "renal stone" protocol CT scans (no oral or intravenous contrast, scans covering the entire urinary tract obtained in helical mode with narrow collimation (< 5 mm)). CT scans were reviewed for the primary finding of urinary tract calculi, for secondary signs of acute urinary tract obstruction and for evidence of alternative diagnoses. Medical records were reviewed to determine clinical presentation and to confirm the eventual diagnosis. RESULTS: One hundred thirty-seven scans of 113 children (mean age: 11.2 years) were studied. Thirty-eight of 94 examinations (40%) performed on 82 children for acute pain and/or hematuria showed ureteral calculi. Alternative diagnoses were suggested by CT on 16 scans (17%). Twenty-eight scans were performed on 10 asymptomatic children with known calculus disease confirming renal stone burden on 21 scans (75%) and persistent ureteral calculi on 6 scans (21%). Upper tract calculi were demonstrated on 10 of 15 scans (67%) performed to evaluate for calculi in patients with known non-calculus genitourinary tract abnormalities. CONCLUSIONS: Non-contrast thin section helical CT is a useful method to diagnose urinary tract calculi in children. Radiation dose in this retrospective study may exceed the lowest possible radiation dose for diagnostic accuracy. Further research is needed to optimize CT imaging parameters, while maintaining diagnostic accuracy and minimizing radiation dose.

Adolescent↗