Peter Mattei

Effects of protein kinase C activators on germinal vesicle breakdown and polar body emission of mouse oocytes

Protein phosphorylation mediated by cAMP-dependent protein kinase is instrumental in maintaining meiotic arrest of mouse oocytes. To assess whether protein phosphorylation mediated by calcium/phospholipid-dependent protein kinase (protein kinase C) might also inhibit the resumption of meiosis, we treated oocytes with activators of this enzyme. The active phorbol esters 12-O-tetra-decanoyl phorbol-13-acetate (TPA) and 4 beta-phorbol 12,13-didecanoate (4 beta-PDD) inhibited germinal vesicle breakdown (GVBD), as did a more natural activator of protein kinase, C, sn-1,2-dioctanoylglycerol (diC8). An inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD), did not inhibit GVBD. We then examined whether protein kinase C activators inhibit a step in the cAMP-modulated pathway that regulates resumption of meiosis. TPA did not inhibit the maturation-associated decrease in oocyte cAMP. Microinjected heat-stable protein inhibitor of cAMP-dependent protein kinase failed to induce GVBD in the presence of TPA. Both TPA and diC8 partially inhibited specific changes in oocyte phosphoprotein metabolism that are tightly correlated with resumption of meiosis; these agents also induced the apparent phosphorylation of specific oocyte proteins. These results suggest that protein kinase C activators may inhibit resumption of meiosis by acting distal to a decrease in cAMP-dependent protein kinase activity, but prior to changes in oocyte phosphoprotein metabolism that are presumably required for resumption of meiosis. Finally, we compared the effects of db-cAMP and protein kinase C activators on polar body emission following GVBD. TPA, 4 beta-PDD or diC8, but not 4 alpha-PDD or db-cAMP, inhibited polar body emission in a dose-dependent manner. The morphology and cytology of oocytes in which polar body emission was inhibited by TPA or 4 beta-PDD differed from that of oocytes treated with diC8. Thirty to 60% of the former were round in shape and exhibited a clump of chromosomes but no spindle; the remainder were distended in shape and exhibited a metaphase I spindle. All oocytes treated with diC8, however, were round, had dispersed chromosomes, and no spindle. These results suggest that, in contrast to resumption of meiosis, polar body emission is inhibited by activation of protein kinase C but not cAMP-dependent protein kinase.

Effects of a phorbol ester on mouse eggs: dissociation of sperm receptor activity from acrosome reaction-inducing activity of the mouse zona pellucida protein, ZP3

Biologically active phorbol esters or a diacylglycerol induce mouse eggs to modify the zona pellucida such that sperm receptor activity is retained but the ability of bound sperm to undergo a complete acrosome reaction is lost (Y. Endo, R.M. Schultz, and G.S. Kopf. 1987. Dev. Biol. 119, 199-209). We now show that purified ZP3 from 12-O-tetradecanoyl phorbol-13-acetate (TPA)-treated eggs possesses full sperm receptor activity but has lost its ability to induce a complete acrosome reaction. The modification of the acrosome reaction-inducing activity of ZP3 from these TPA-treated eggs differs from ZP3 isolated from two-cell embryos, which cannot initiate the acrosome reaction. These results demonstrate the dissociation of the two biological activities of ZP3 and may provide a system to assess the components of ZP3 involved in the acrosome reaction.

Morbidity and mortality in patients with esophageal atresia.

BACKGROUND This study reports national estimates of population characteristics and outcomes for patients with esophageal atresia with or without tracheoesophageal fistula (EA/TEF) and evaluates the relationships between hospital volume and outcomes. METHODS Patients admitted within 30 days of life who had International Classification of Diseases, 9th Edition, Clinical Modification diagnosis and procedure codes relevant to EA/TEF during 1999-2012 were identified with the Pediatric Health Information System database. Baseline demographics, comorbidities, and postoperative outcomes, including predictors of in-hospital mortality, were examined up to 2 years after EA/TEF repair. RESULTS We identified 3,479 patients with EA/TEF treated at 43 childrens hospitals; 37% were premature and 83.5% had ≥1 additional congenital anomaly, with cardiac anomalies (69.6%) being the most prevalent. Within 2 years of discharge, 54.7% were readmitted, 5.2% had a repeat TEF ligation, 11.4% had a repeat operation for their esophageal reconstruction, and 11.7% underwent fundoplication. In-hospital mortality was 5.4%. Independent predictors of mortality included lower birth weight, congenital heart disease, other congenital anomalies, and preoperative mechanical ventilation. There was no relationship between hospital volume and mortality or repeat TEF ligation. CONCLUSION This study describes population characteristics and outcomes, including predictors of in-hospital mortality, in EA/TEF patients treated at childrens hospitals across the United States. Across these hospitals, rates of mortality or repeat TEF ligation were not dependent on hospital volume.

Use of laparoscopic cholecystectomy for biliary dyskinesia in the child.

BACKGROUND Biliary dyskinesia (BD) is a consideration as a cause of chronic abdominal pain in the pediatric population. We sought to correlate the results of cholecystokinin-diisopropyl iminodiacetic acid (CCK-DISIDA) scanning, the basis for diagnosis of BD, with outcome after laparoscopic cholecystectomy. METHODS A retrospective review was performed of all patients who underwent a laparoscopic cholecystectomy from May 2000 through March 2007. The diagnosis of BD was based on CCK-DISIDA scan demonstrating a gallbladder ejection fraction (GBEF) of less than 35% and/or reproduction of pain on CCK administration or no filling of the gall bladder with a normal ultrasound examination. Hospital, General Surgery office, and Gastroenterology Office charts were reviewed for demographic and management data points. We used chi(2) and Mann-Whitney tests for statistical analysis. RESULTS For the period of review, 430 patients underwent a laparoscopic cholecystectomy including 75 patients with a preoperative diagnosis of BD. The mean age of the BD population was 14 (range, 9-19) years. Female to male ratio was 2.4:1. The mean body mass index was 24.4 kg/m(2). On average, patients had abdominal symptoms for 15.5 (range, 0.25-72) months. Each patient underwent nearly 2.5 studies (computed tomography, ultrasound, esophagogastroduodenoscopy, or upper gastrointestinal series) before diagnosis by CCK-DISIDA. The mean GBEF was 17.4%. When commented on (n = 41), pain on CCK administration was noted in 25 (61%) patients. Pathology revealed chronic cholecystitis in 44%. After laparoscopic cholecystectomy, 58 (77.33%) patients reported resolution of their abdominal pain (mean follow-up 4 months). Of the 17 patients without improvement, 7 were later diagnosed with other underlying pathology (Crohns, hiatal hernia, cyclic vomiting). There was no difference in GBEF, age, histopathology, or sex between the two groups. There were no complications. CONCLUSION Laparoscopic cholecystectomy is a safe and effective treatment for the majority of children diagnosed with BD. Although CCK-DISIDA was used to identify biliary dysfunction, it did not correlate with outcome.

Hepaticoduodenostomy vs hepaticojejunostomy for reconstruction after resection of choledochal cyst.

PURPOSE Roux-en-Y hepaticojejunostomy (HJ) is currently the favored reconstructive procedure after resection of choledochal cysts. Hepaticoduodenostomy (HD) has been argued to be more physiologically and technically easier but is feared to have associated complications. Here we compare outcomes of the 2 procedures. METHODS A retrospective chart review identified 59 patients who underwent choledochal cyst resection within our institution from 1999 to 2009. Demographic and outcome data were compared using t tests, Mann-Whitney U tests, and Pearson χ(2) tests. RESULTS Fifty-nine patients underwent repair of choledochal cyst. Biliary continuity was restored by HD in 39 (66%) and by HJ in 20 (34%). Open HD patients required less total operative time than HJ patients (3.9 vs 5.1 hours, P = .013), tolerated a diet faster (4.8 days compared with 6.1 days, P = .08), and had a shorter hospital stay (7.05 days for HD vs 9.05 days for HJ, P = .12). Complications were more common in HJ (HD = 7.6%, HJ = 20%, P = .21). Three patients required reoperation after HJ, but only one patient required reoperation after HD for a stricture (HD = 2.5%, HJ = 20%, P = .037). CONCLUSIONS In this series, HD required less operative time, allowed faster recovery of bowel function, and produced fewer complications requiring reoperation.

Complex vascular reconstruction of abdominal aorta and its branches in the pediatric population

BACKGROUND Subdiaphragmatic aortic diseases in children are rare and form a heterogeneous group. The pediatric patient presents unique challenges because of their size, concerns about proper timing and conduit for repair, and anticipating expected growth. METHODS We performed a retrospective review of operations involving the abdominal aorta and called branches in children between January 2003 and April 2007, focusing on the details of preoperative evaluation, operative technique, and outcomes. The pertinent literature is reviewed. RESULTS Twenty-two children (age, 2 days to 17 years) were included. Mean follow-up was 28 months. Aneurysms were seen in 5 children; the remainder had stenotic disease. Aneurysms were typically asymptomatic and diagnosed incidentally, whereas stenotic lesions most commonly presented with hypertension (HTN). Fourteen complex vascular repairs were performed. All of the children with aneurysms underwent prompt surgery. The children with stenoses had operations for poorly controlled HTN, claudication, and/or mesenteric ischemia. Most patients with stenotic disease were treated medically for HTN and were followed closely while awaiting optimal size and availability of autogenous conduit for reconstruction. Cryopreserved allograft was used in 3 of the aneurysm operations. Dacron grafts were used to repair 5 aortic stenotic lesions. Renal and mesenteric revascularizations were performed with saphenous vein grafts. Pediatric, general, and transplant surgeons and nephrologic and cardiologic teams were integral to evaluation and management. No major operative complications occurred. CONCLUSION Proper management of pediatric aortic vascular disease requires a multidisciplinary approach. It is best to use autologous grafts whenever possible. Children with stenotic disease should be treated medically for hypertension until they are large enough for an autologous graft reconstruction. Children with aneurysmal disease are at risk for embolism and thrombosis and therefore usually treated immediately using artificial graft material, if necessary.

Laparoscopic Adrenalectomy in Children: A Multicenter Experience

INTRODUCTION Laparoscopic adrenalectomy is now being recognized as the standard approach for adrenalectomy for benign lesions in adults. The published experience in children and adolescents has been limited to sporadic small case series. Therefore, we conducted a large multicenter review of children who have undergone laparoscopic adrenalectomy. METHODS After Institutional Review Boards approval, a retrospective review was conducted on all patients who have undergone laparoscopic adrenalectomy at 12 institutions over the past 10 years. Operative times included unilateral adrenalectomy without concomitant procedures. RESULTS About 140 patients were identified (70 males [50%]). Laterality included 76 (54.3%) left-sided lesions, 59 (42.1%) right, and 5 (3.6%) bilateral. Mean operative time was 130.2 ± 63.5 minutes (range 43-406 minutes). The most common pathology was neuroblastoma in 39 cases (27.9%), of which 23 (59.0%) had undergone preoperative chemotherapy. Other common pathology included 30 pheochromocytomas (21.4%), 22 ganglioneuromas (15.7%), and 20 adenomas (14.3%). There were 13 conversions to an open operation (9.9%). Most conversions were because of tumor adherence to surrounding organs, and tumor size was not different in converted cases (P=.97). A blood transfusion was required in 2 cases. The only postoperative complication was renal infarction after resection of a large neuroblastoma that required skeletonization of the renal vessels. At a median follow-up of 18 months, there was only one local recurrence, which was in a patient with a pheochromocytoma. CONCLUSIONS The laparoscopic approach can be applied for adrenalectomy in children for a wide variety of conditions regardless of age with a 90% chance of completing the operation without conversion. The risk for significant blood loss or complications is low, and it should be considered the preferred approach for the majority of adrenal lesions in children.

Rapid regression of duodenal inflammatory myofibroblastic tumor after intravenous ketorolac: case report and review of the literature.

Inflammatory myofibroblastic tumors are known to sometimes regress spontaneously or in response to treatment with antiinflammatory drugs. We present the case of a 13-year-old boy with an inflammatory myofibroblastic tumor of the proximal duodenum, which regressed rapidly within days of an open surgical biopsy, resulting in perforation of the duodenum. Ketorolac was administered intravenously after the biopsy and is implicated as a potential cause of the rapid regression of the tumor. We discuss the surgical management of this patient and present a review of the literature.

Minimally invasive surgery in the diagnosis and treatment of abdominal pain in children

Purpose of review Children with abdominal pain sometimes require surgical intervention, and laparoscopy is increasingly the preferred approach for the diagnosis and treatment of both acute and chronic abdominal pain in children. This review describes the current state of the art and recent developments in the application of minimally invasive surgical techniques for the treatment of children with various abdominal pain syndromes. Recent findings Laparoscopy provides distinct advantages over traditional open surgery, including less pain, shorter recovery and improved cosmesis. Cumulative experience and ongoing outcomes research continue to substantiate the safety and efficacy of the approach when applied thoughtfully and by experienced practitioners. In fact, as minimally invasive surgery is being applied to treat more wide-ranging disorders, it is becoming apparent that for many conditions laparoscopy should be adopted as the standard of care. Summary Recent advances in minimally invasive surgery have clearly benefited children with abdominal pain who need surgery, and as techniques improve and instruments get smaller we can expect this trend to continue into the future.

Bilateral Pheochromocytomas, Hemihyperplasia, and Subtle Somatic Mosaicism: The Importance of Detecting Low-Level Uniparental Disomy

We report on a patient with early onset pediatric bilateral pheochromocytomas caused by mosaic chromosome 11p15 paternal uniparental isodisomy (UPD). Hemihyperplasia of the arm was diagnosed in a 4‐month‐old female and clinical methylation testing for 11p15 in the blood was normal, with a reported detection threshold for mosaicism of 20%. She was subsequently diagnosed at 18 months with bilateral pheochromocytomas. Single‐nucleotide polymorphism (SNP) array analysis of pheochromocytoma tissue demonstrated mosaic deletions of 8p12pter, 21q21.1qter, 22q11.23qter; commonly seen in pheochromocytomas. In addition, mosaic 11p15.3pter homozygosity was noted. Molecular testing for other causes of pheochromocytomas was normal, suggesting that 11p15 homozygosity was the primary event. Subsequent SNP array analysis of skin fibroblasts from the hyperplastic side demonstrated 5% mosaic paternal UPD for 11p15. We have subsequently used SNP array analysis to identify four patients with subtle hemihyperplasia with low‐level mosaic UPD that was not detected by methylation analysis. Given the increased sensitivity of SNP array analysis to detect UPD along with the increased incidence of tumorigenesis in these UPD patients, we suggest that it has high utility in the clinical work‐up of hemihyperplasia. The present case also suggests that 11p15 paternal UPD may be an under‐detected mechanism of sporadic pheochromocytoma in the pediatric population. Furthermore, a review of the literature suggests that patients with 11p15 paternal UPD may present after 8 years of age with pheochromocytoma and raises the possibility that ultrasound screening could be considered beyond 8 years of age in this subset of hemihyperplasia and Beckwith–Wiedemann syndrome patients.