Biometric and morphological features on magnetic resonance imaging of fetal bladder in lower urinary tract obstruction: new perspectives for fetal cystoscopy.

OBJECTIVES: Incompatibility between currently available fetoscopes and the anatomical constraints of the distended fetal bladder, with the resulting curvature around the bladder neck, account for most technical difficulties during fetal cystoscopy in lower urinary tract obstruction (LUTO). The aim of this anatomical study was to assess by magnetic resonance imaging (MRI) the variation in three bladder angles (bladder-neck angle (BNA), vesicourethral angle (VUA) and angle between bladder dome and posterior urethra (DUA)), according to gestational age (GA), bladder volume and the presence of LUTO. METHODS: From our fetal medicine database, we retrieved for review 46 MRI examinations of male fetuses between 2015 and 2019, including 17 with LUTO, examined at a mean GA of 28.1 (range, 17.3-35.0) weeks and 29 age-matched controls, examined at 29.9 (range, 21.9-35.0) weeks. We measured bladder volume, bladder-wall thickness and the three bladder angles, and used the Mann-Whitney U-test to compare values between groups. Variations according to GA and bladder volume were determined using analysis of variance (ANOVA). A reliability study was performed using the Bland-Altman method and Lin's correlation coefficient was calculated. RESULTS: Both bladder volume and bladder-wall thickness were significantly greater in the LUTO group (P < 0.01). BNA was significantly larger in LUTO compared with control fetuses: the mean (range) was 127.1° (101.6-161.6°) vs 111.2° (88.5-157.3°) (P < 0.01). DUA averaged 117° and showed no difference between the groups (P = 0.92). No statistical comparison was performed on VUA since this was not measurable in most control fetuses. ANOVA showed no variation of any angle with bladder volume in both LUTO fetuses and control fetuses. BNA in LUTO fetuses was the only angle to vary with GA, being larger after, compared with at or before, 25 weeks (P = 0.04). The reliability study showed an acceptable bias for both intra- and interobserver reproducibility for all three angles. CONCLUSION: The findings that BNA is increased by approximately 15° in fetuses with LUTO and DUA averages 117° could aid in development of a customized fetal cystoscope and help to overcome the current technical challenges of fetal cystoscopy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Renal transplantation in 4 patients with methylmalonic aciduria: a cell therapy for metabolic disease.

INTRODUCTION: Patients with methylmalonic acidemia (MMA) may develop many complications despite medical treatment, in particular, severe central nervous system damage and chronic kidney disease (CKD). A kidney transplant may partially correct the metabolic dysfunctions. Liver, kidney and combined liver-kidney transplantations have been advocated but no guidelines are available to identify the most suitable organ to transplant. PATIENTS AND METHODS: Four patients with MMA (mut° phenotype) received a kidney graft because of repeated metabolic decompensations, with progression to CKD in 3 patients (end-stage kidney disease in two patients and CKD stage III in one patient with an estimated glomerular filtration rate [eGFR] of 40ml/min/1.73m(2)) but normal renal function in one (eGFR of 93ml/min/1.73m(2)) before transplantation. RESULTS: The medium age at transplantation was 7.9y (5-10.2) and the median follow-up was 2.8years (1.8-4.6). Renal transplantation improved the relevant metabolic parameters in 4/4 patients and renal function in the patients with CKD. Plasma and urinary MMA levels immediately decreased and remained normal or subnormal (mean values of plasma MMA before transplantation 1530µmol/L versus 240µmol/L after transplantation, and mean values of urine MMA before transplantation 4700mmol/mol creatinine versus 2300mmol/mol creatinine after transplantation). No further acute metabolic decompensation was observed and protein-intake was increased from 0.60 to 0.83g/Kg/day. One patient transplanted at age 9.7years developed a hepatoblastoma at age 11years with subsequent neurological complications and eventually died. The three other patients are alive. Two of them remained neurologically stable. The 3rd patient who displayed choreoathetosis transiently improved his neurological condition immediately after transplantation and then remained stable. CONCLUSION: Kidney transplantation represents an interesting alternative therapeutic option in methylmalonic aciduria, for renal complications but also as a "cellular therapy" that may significantly reduce metabolic decompensations and hospitalizations. However, further neurological impairment remains possible.

ABCC8 and KCNJ11 molecular spectrum of 109 patients with diazoxide-unresponsive congenital hyperinsulinism.

BACKGROUND: Congenital hyperinsulinism (CHI) is characterised by an over secretion of insulin by the pancreatic ß-cells. This condition is mostly caused by mutations in ABCC8 or KCNJ11 genes encoding the SUR1 and KIR6.2 subunits of the ATP-sensitive potassium (K(ATP)) channel. CHI patients are classified according to their responsiveness to diazoxide and to their histopathological diagnosis (either focal, diffuse or atypical forms). Here, we raise the benefits/limits of the genetic diagnosis in the clinical management of CHI patients. METHODS: ABCC8/KCNJ11 mutational spectrum was established in 109 diazoxide-unresponsive CHI patients for whom an appropriate clinical management is essential to prevent brain damage. Relationships between genotype and radiopathological diagnosis were analysed. RESULTS: ABCC8 or KCNJ11 defects were found in 82% of the CHI cases. All patients with a focal form were associated with a single K(ATP) channel molecular event. In contrast, patients with diffuse forms were genetically more heterogeneous: 47% were associated with recessively inherited mutations, 34% carried a single heterozygous mutation and 19% had no mutation. There appeared to be a predominance of paternally inherited mutations in patients diagnosed with a diffuse form and carrying a sole K(ATP) channel mutation. CONCLUSIONS: The identification of recessively inherited mutations related to severe and diffuse forms of CHI provides an informative genetic diagnosis and allows prenatal diagnosis. In contrast, in patients carrying a single K(ATP) channel mutation, genetic analysis should be confronted with the PET imaging to categorise patients as focal or diffuse forms in order to get the appropriate therapeutic management.

[Prenatal path of care following the diagnosis of a malformation for which a novel prenatal therapy is available]. / Parcours prénatal devant une malformation pour laquelle un traitement in utero émergent est disponible.

OBJECTIVES: Fetal therapy is part of the available care offer for several severe malformations. The place of these emergent prenatal interventions in the prenatal path of care is poorly known. The objective of this study is to describe the decision-making process of patients facing the option of an emergent in utero intervention. METHODS: We have conducted a retrospective monocentric descriptive study in the department of maternal-fetal medicine of Necker Hospital. We collected data regarding eligibility or not for fetal surgery and the pregnancy outcomes of patients referred for myelomeningocele, diaphragmatic hernia, aortic stenosis and low obstructive uropathies. RESULTS: All indications combined, 70% of patients opted for fetal surgery. This rate was lower in the case of myelomeningocele with 21% consent, than in the other pathologies: 69% for diaphragmatic hernias, 90% for aortic stenoses and 76% for uropathy. When fetal intervention was declined, the vast majority of patients opted for termination of pregnancy: 86%. In 14% of the considering fetal surgery, the patient was referred too far. CONCLUSION: The acceptance rate for fetal surgeries depends on condition. It offers an additional option and is an alternative for couples for which termination of pregnancy (TOP) is not an option. Timely referral to an expert center allows to discuss the place of a fetal intervention and not to deprive couples of this possibility.

Renal transplantation in children: critical analysis of age related surgical complications.

To determine age-related risk factors of urological and vascular complications. We performed a retrospective analysis of the data of 202 renal transplantations in 193 children between 1989 and 2007 at a single institution. Out of 193 grafts (combined renal and liver grafts were excluded), we observed urological complications in 42 cases (21.7%) leading to graft loss in one case and vascular complications in 27 cases (13.9%) leading to graft loss in seven. The urological complications were VUR (n=25, 12.4%), ureteral stricture (n=10, 5%), anastomotic leak (n=4, 2%), ureteral necrosis (n=2, 1%), and incrustative pyelitis (n=1, 0.5%). Vascular complications were arterial stricture (n=14, 7.2%), arterial thrombosis (n=4, 2%), venous thrombosis (n=2, 1%), and others (n=7). Donors aged less than six yr were a risk factor of vascular complications leading to graft loss (p=0.0001), whereas patients with PUV had more urological complications (p=0.001). Overall patient and graft survival is 93.1% and 84% at five yr, respectively. Surgical complications remain a major cause of graft loss (12%) and morbidity in children's kidney transplantation (38.9%). Young age of donors is the major risk factor of early graft loss as a result of vascular complication. However, donor selection based on age is limited by the shortage of organs.

Left lateral retroperitoneoscopic total nephrectomy of a horseshoe kidney in a 3-year-old boy.

The unilateral or bilateral approach for nephrectomy in horseshoe kidney by minimally invasive surgery has been described. A total binephrectomy by a unilateral retroperitoneoscopic approach was performed for congenital nephrotic syndrome. A unilateral retroperitoneoscopic approach was planned in a 3-year-old boy (13 kg) with congenital nephrotic syndrome resistant to steroids with massive protein loss. The operative time was 160 min. The postoperative course was uneventful with continued hemodialysis until renal transplant 18 months later. The unilateral retroperitoneal approach allows total nephrectomy to be completed safely in horseshoe kidney for benign disease. The retroperitoneal access preserves the abdominal cavity, should peritoneal dialysis be required.

Chromosome 11p15 paternal isodisomy in focal forms of neonatal hyperinsulinism.

CONTEXT: Focal forms of congenital hyperinsulinism are due to a constitutional heterozygous mutation of paternal origin in the ABCC8 gene, more often than the KCNJ11 gene, located in the 11p15.1 region. This mutation is associated with the loss of the maternally inherited 11p15.1 to 11p15.5 region in the lesion. We investigated the possible occurrence of a compensatory duplication of the paternal 11p15.1-11p15.5 region. MATERIALS AND METHODS: A combined immunohistochemistry and fluorescent in situ hybridization study on beta-cell interphase nuclei with probes covering two genes located in this region (ABCC8 and CDKN1C genes) was performed in four cases of focal forms of hyperinsulinism. RESULTS: beta-Cells in the lesions of four cases of focal congenital hyperinsulinism were diploid for chromosomes 11 and 13. The 11p15.1 to 11p15.2 and 11p15.4 to 11p15.5 regions containing ABCC8 and CDKN1C genes, respectively, were present with two copies. Loss of the maternal allele was confirmed in these focal lesions with microsatellite markers flanking the ABCC8 and CDKN1C genes, whereas a heterozygous mutation in the ABCC8 gene was inherited from the father. CONCLUSIONS: There is a duplication of the paternal allele on chromosome 11 in the focal forms of hyperinsulinism lesion. The paternal isodisomy observed rendered the beta-cells homozygous for ABCC8 mutation and harbored a K-channel defect in the lesion similar to that observed in diffuse forms of congenital hyperinsulinism.

Ventilation-induced pulmonary vasodilatation in lambs with congenital diaphragmatic hernia is modulated by nitric oxide.

Endogenous nitric oxide (NO) mediates pulmonary vasodilatation at birth, but inhaled NO fails to reduce pulmonary vascular resistance (PVR) in newborns with congenital diaphragmatic hernia (CDH). This study was designed to investigate the effects of ventilation, and the nature of its endogenous mediator, in fetal lambs with experimental CDH. Investigations at 138 days of gestation showed that ventilation markedly decreased PVR. Inhibition of NO synthesis reduced ventilation-induced pulmonary vasodilatation in vivo and increased in vitro isometric tension of vascular rings. Ventilation therefore reduces PVR at birth in lambs with CDH, and endogenous NO seems to contribute to this reduction.

Is intestinal transplantation the future of children with definitive intestinal insufficiency?

UNLABELLED: Intestinal transplantation (IT) is the newest and most difficult of organ transplantations. The first ever (1987) and the longest surviving (1989) IT were performed in our institution. However, IT still has to demonstrate its benefit to children on long-term parenteral nutrition (PN). We tried to clarify this aspect by looking back at our 13 years' experience. PATIENTS: From 1994 to December 2007, 74 IT were performed in 69 children, 39 with an isolated small bowel (IT), 35 combined with a liver transplant (LITx). The indications were: short bowel syndrome (n = 25), congenital mucosal diseases (n = 22), and motility disorders (n = 22). Median age at transplantation was 5 years (1 - 17 years). Follow-up was 1 to 12 years (median 5 years). RESULTS: Thirty-one children have a functioning graft (42 %), 15/39 IT, 16/35 LITx. They are at home without PN, with a good quality of life. One child is PN-dependent 1.5 years post IT. Post IT, 16 children were detransplanted: 12 early on (1 for mechanical complications, 11 because of resistant rejection; 3 less than 3 years, one 9 years post SBT (chronic rejection). In 2 noncompliant teenagers, PN was reintroduced (one was detransplanted later on). Several years post LITx, 2 children underwent bowel detransplantation due to an acute viral infection complicated with rejection. Twenty-two children died (32 %, 8 IT, 14 LITx), 18 early on from infectious or surgical complications, 4 more than 1 year post IT, 3 after retransplantation (1 in another unit). Bad prognostic factors are multiple previous surgeries, an older age (> 7 y), and chronic intestinal pseudo-obstruction. DISCUSSION: Complications post IT are frequent and life-threatening, especially early on: rejection (IT), infections (LITx). Later on, the rate of complications decreases but remains significant, especially in noncompliant patients. However we describe here a 13-year learning curve; the recent results are encouraging with regard to control of rejection and viral infections. CONCLUSION: Intestinal transplantation is indicated only in selected patients in whom long-term PN cannot be performed safely any more. In every child with intestinal insufficiency, the therapeutic strategy must be discussed early on in order to perform IT at the right time under optimal conditions. IT should evolve from being a "rescue" procedure to becoming a true therapeutic option.

Neonatal hyperinsulinism: clinicopathologic correlation.

Neonatal hyperinsulinism is a life-threatening disease that, when treated by total pancreatectomy, leads to diabetes and pancreatic insufficiency. A more conservative approach is now possible since the separation of the disease into a nonrecurring focal form, which is cured by partial surgery, and a diffuse form, which necessitates total pancreas removal only in cases of medical treatment failure. The pathogenesis of the disease is now divided into K-channel disease (hyperinsulinemic hypoglycemia, familial [HHF] 1 and 2), which can mandate surgery, and other metabolic causes, HHF 3 to 6, which are treated medically in most patients. The diffuse form is inherited as a recessive gene on chromosome 11, whereas most cases of the focal form are caused by a sulfonylurea receptor 1 defect inherited from the father, which is associated with a loss of heterozygosity on the corresponding part of the mother's chromosome 11. The rare bifocal forms result from a maternal loss of heterozygosity specific to each focus. Paternal disomy of chromosome 11 is a rare cause of a condition similar to Beckwith-Wiedemann syndrome. A preoperative PET scan with fluorodihydroxyphenylalanine and perioperative frozen-section confirmation are the types of studies done before surgery when needed. Adult variants of the disease are less well defined at the present time.

Gastrointestinal complications of post-diarrheal hemolytic uremic syndrome.

PURPOSE: Whereas gastrointestinal symptoms such as vomiting, diarrhea and abdominal pain are common in children suffering from the so-called post-diarrheal form (D+) of hemolytic uremic syndrome (HUS), more serious gastrointestinal complications are rare. We tried to define factors predictive of the severity of gastrointestinal complications post D+ HUS. METHODS: We reviewed the files of all children admitted to our hospital for D+ HUS between 1988 and 2000. We retained those cases with gastrointestinal complications and analyzed the consequences of these complications on the evolution of the children's conditions. RESULTS: Sixty-five children with D+ HUS were admitted to our hospital during this period. Sixteen children developed gastrointestinal complications involving one or more digestive organs: necrosis of the colon or ileum, hemorrhagic colitis, pancreatitis, transient diabetes, hepatic cytolysis and cholestasis, peritonitis and prolapse of the rectum. One child died. CONCLUSION: Gastrointestinal complications of D+ HUS are rare, but they can be lethal, and early surgery may sometimes prove necessary. However, we were not able to demonstrate a correlation between the severity of the gastrointestinal manifestations and the clinical or biological signs accompanying D+ HUS.

Gastroschisis and omphalocele: retrospective study of initial postoperative management in the ICU.

AIM OF THE STUDY: The purpose of this study is to describe the management of infants with gastroschisis (G) and omphalocele (O) during the first 7 days after surgery. METHODS: A retrospective review of all cases of O or G managed at the ICU of the Robert Debré Teaching Hospital between January 1993 and July 2000 was carried out. PATIENTS: 29 infants with G, 15 with O (12 unruptured O [UO] and 3 ruptured O [RO]). RESULTS: Ventilatory support consisted of conventional mechanical ventilation (46 %) and/or in high-frequency oscillatory ventilation (61 %). After day 4, ventilatory requirements evaluated by mean airway pressure (MAP) differed significantly between G (n = 10/29) and O (n = 7/15; group vs. day of life, p = 0.04). The average of MAP measured on days 5, 6, and 7 was significantly higher in O than in G (14.7 +/- 3.0 versus 10.9 +/- 2.8, p < 0.01, respectively). Volume expansion was required at least once in 90 % of patients. Mean fluid requirements were significantly lower in UO than in G and in RO (41 +/- 31 ml/kg, 91 +/- 73 ml/kg, and 137 +/- 25 ml/kg, respectively; p = 0.02 for each comparison). Patients with G were significantly more likely to receive norepinephrine (59 % vs. 20 %, p = 0.027) than patients with O. Twenty-six infants with G (90 %) and 11 with O (73 %) were discharged alive from ICU. CONCLUSIONS: Haemodynamic instability can be expected in patients with G or RO, and ventilatory requirements were higher in infants with O than in infants with G during the first week after surgery.

Crohn's disease in children. Preliminary experience with a laparoscopic approach.

BACKGROUND: Laparoscopic surgery in patients with Crohn's disease (CD) has been demonstrated to have advantages over a conventional approach in children. The aim of this study was to review the children treated for CD with a laparoscopic approach, to report our indications, the surgical procedure, the complications, and to compare the children with pancolitis or ileocaecal (segmental) Crohn's disease. PATIENTS AND METHOD: We reviewed the files of 11 children treated for CD in a single institution between 1999 and 2004 for a retrospective study of clinical and surgical data. Mann-Whitney U-test was used for statistical analysis of nonparametric data. RESULTS: Eleven children were operated. The average age when initial clinical symptoms became apparent was 12.1 years (range 6.6 - 15), and surgery was performed after an average of 3.4 years of disease (range 1 - 7.6). The surgical indications were stenosis in 6 cases, failure to thrive in 1 case (segmental CD, SCD group) and pancolitis refractory to medical treatment in 4 cases (pancolitis group, PCD group). Mean operative time was 207 minutes (range 140 - 270) for the SCD group and 285 minutes (range 260 - 300) for the PCD group (p < 0.05). Three cases needed a conversion to open surgery (2 in PCD group, one in SCD group), mainly in relation to anastomosis performed with an EEA stapler. The average length of surgical unit stay was 6.5 days (range 4 - 8) for the PCD group and 6.4 days (range 4 - 8) for the SCD group; average follow-up was 16 months (range 3 - 38). Two patients had a relapse of CD (stenosis of the anastomosis in one, skin fistula in the other). CONCLUSION: A laparoscopic approach for ileocolic resection in Crohn's disease is a feasible procedure, even in cases of pancolitis. We recommend an extra-corporeal anastomosis because, in relation to the inflammatory bowel, the mechanical anastomosis is not a safe procedure in cases of pancolitis.

[Rhabdomyosarcoma of the genitourinary sinus in children]. / Rhabdomyosarcomes du sinus urogénital de l'enfant.

Genitourinary rhabdomyosarcoma (RMS) accounts for approximately 25% of all rhabdomyosarcomas. Management of RMS at this site has changed during the last 5 consecutive Intergroup Rhabdomyosarcoma (IRS) trials, with increasing emphasis of bladder and vaginal conservation. As more effective treatment regimens has improved survival, surgical approaches have evolved to less aggressive management of the primary tumour to improve conservation. Various combinations of chemotherapy, irradiation and surgery have resulted in a decreased late sequelae in the group of patients with sarcoma arising in the genitourinary tract.

Left thoracoscopic thymectomy in children.

BACKGROUND: In the management of autoimmune myasthenia, thymectomy is recognized as effective surgical therapy. The necessity of complete radical thymectomy to achieve maximal improvement has been emphasized. Video-assisted thoracoscopic surgery has been successfully used for thymectomy in adults, and more recently in children, and has been described as achieving the same radicality and functional improvement as median sternotomy or as transcervical thymectomy. The aim of this work is to report our first thoracoscopic experience in this indication. METHODS: Patients with myasthenia gravis on anticholinesterase drugs and/or steroids are discussed for surgery in case of clinical deterioration despite increasing doses of medication or in case of no improvement. We decided to perform thoracoscopic thymectomies by a left-sided approach. Preoperative localization of thymic tissue is done by a thoracic CT exam. Patients are placed on their right side with a thoracic tilt under the thorax. Four thoracoscopic ports are used, a 10-mm for the camera and three 5-mm operating ports. The left lung was collapsed by selective intubation (double-lumen endotrachial intubation). RESULTS: Two boys, 7.5 and 14 years old, were addressed by the department of neurology for radical thymectomy. They presented an ocular myasthenia gravis for 2 years and a mild general myasthenia gravis for 7 years. The operative times were 120 and 240 min. There was no intraoperative or postoperative complication. Duration of thoracic drainage was 2 days. The children were discharged on the third postoperative day. For the second procedure, an ultrasound exam during surgery was necessary to localize the thymus exactly, thus enabling its complete resection without the need for a conversion. The follow-up is 19 and 7 months with a clinical improvement enabling the diminution of medication for both children, the end of ptosis for the first child, and the general improvement of muscle strength for the second. CONCLUSIONS: Thoracoscopic thymectomy in children with juvenile myasthenia gravis seems to offer a complete surgical resection, as do open techniques. In case of difficulties in finding the thymus, an ultrasound exam is feasible to enable complete resection. The left-sided thoracoscopic approach gives a good mediastinal and cervical exposition. Furthermore, being less painful in the postoperative period, it presents a less pronounced impairment of pulmonary function, and it presents good cosmetic effect.

Open vs thorascopic surgical management of bronchogenic cysts.

BACKGROUND: The aim of this study was to compare the operative outcome in children undergoing open vs thoracoscopic resection of bronchogenic cysts. METHODS: The medical records of children who underwent the resection of bronchogenic cysts from 1990 through 2000 were reviewed. Four cyst resections were performed by the open technique and five using a thoracoscopic procedure. The age of the patients, length of hospital stay, duration of drainage, operating time, and outcome were investigated. RESULTS: The mean age of patients undergoing the open procedure was 3 years and 3 months; the mean age for thoracoscopy patients was 7 years and 10 months (p < 0.05). The operating time for the open procedure was 70 +/- 25 min; for the laparoscopic procedure, it was 78 +/- 6 min (p, NS), except in one case with a main bronchial tail that required conversion (320 min). Duration of surgical drainage was 6.5 +/- 3 days for the open procedure and 2.5 +/- 1 days for the thoracoscopic one (p < 0.05). Hospital stay for open patients was 12 days +/- 0 days; it was 6 +/- 1.6 days for thoracoscopic patients (p < 0.01). There were no deaths. The thoracoscopic procedure failed once due to a main bronchial tail and had to be converted to an open procedure. Other early complications included a bronchopulmonary infection after an open cyst excision and an atelectasis after a thoracoscopic cyst excision. Late complications included one reoperation for incomplete excision in each of the two groups. CONCLUSION: Bronchogenic cyst resection can be performed safely. For complete treatment of these patients, total excision of the wall cyst is needed. In selected patients, the thoracoscopic procedure may decrease the duration of surgical drainage and length of hospital stay without increasing the operating time or MSK for complications.

[Imaging strategy for children after a first episode of pyelonephritis]. / Explorations morphologiques après un premier épisode de pyélonéphrite chez l'enfant.

Pyelonephritis is a common bacterial disease in young children and is a serious infection because of its potential to produce renal scarring. One of the concerns of physicians is therefore the diagnosis of uropathy at risk for recurrence of pyelonephritis, especially high-grade reflux. There are no French recommendations on imaging evaluation after a first episode of pyelonephritis. Voiding cystography was systematically proposed years ago and recommended by the American Academy of Pediatrics until 1999. This systematic strategy exposed all children to a painful, irradiating exam, and exposed them to urinary tract infection. The American recommendations changed in 2011 and cystography is now only proposed to children with recurrence of pyelonephritis or with ultrasound abnormalities. A collaborative review of the literature involving the Pediatric Emergency, Nephrology and Surgery Departments at Necker-Enfants-Malades Hospital led us to propose an algorithm for imaging after the first episode of pyelonephritis in children. This algorithm was based on data from the past medical history (results of prenatal ultrasonography or recurrence of pyelonephritis), the results of the ultrasound exam at the time of diagnosis, and the procalcitonin concentration, to limit the indications for voiding cystography, limiting risk for delaying high-grade reflux diagnosis. Children with low risk for high-grade reflux can be followed up with an ultrasound exam 6 months after acute infection.

Interleukin-6 and interleukin-1 beta production in a pediatric plasma cell granuloma of the lung.

Plasma cell granuloma (PCG) is a pseudotumor of unknown origin. It is frequently accompanied by acute-phase clinical and biological signs that resume after complete surgical removal, suggesting production of soluble mediators. We therefore investigated the role of cytokines in a previously healthy 10-year-old boy with a PCG of the lung and systemic symptoms. In this case, very high serum levels of interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were found before tumor excision, associated with inflammatory signs including major hyper-gamma-globulinemia. Pathologic analysis of the tumor showed an accumulation of fibroblasts and plasma cells producing immunoglobulins. Local production of IL-1 beta and IL-6 could be demonstrated at the messenger RNA (mRNA) level by the reverse transcriptase polymerase chain reaction and could be attributed to inflammatory cells by in situ hybridization and immunohistochemistry, whereas plasma cells exhibited membrane expression of the IL-6 receptor. Postsurgery follow-up showed rapid normalization of serum IL-1 beta and IL-6, whereas inflammatory protein levels decreased. This confirms the local production of cytokine within the PCG and raises the question of whether a dysregulation of cytokine production initiates the disease.

Enrichment of MLR-activated human suppressor cells by discontinuous density-gradient centrifugation.

6-day allogeneic mixed lymphocyte cultures (MLR) were fractionated on a four-step discontinuous Percoll gradient. The various fractions were added as regulatory cells to freshly established micro-MLRs between the original or third-party cell donors. Unspecific suppressor activity was highly enriched in gradient fraction III (density 1.069--1.062 g/ml), consisting mainly of blast-like cells. Suppressor cells were non-adherent T cells as determined by their spontaneous rosette formation with sheep erythrocytes and their susceptibility to lysis by anti-T-cell globulin plus complement. Mitomycin C treatment diminished their inhibitory capacity. In addition, gradient fraction III was also enriched with alloantigen-activated memory cells. By contrast, unprimed alloreactive cells were recovered from gradient fraction IV (density greater than or equal to 1.070 g/ml), consisting mainly of small, resting lymphocytes.

Molecular markers for differentiation of multiresistant Klebsiella pneumoniae isolates in a pediatric hospital.

OBJECTIVE: To study the spread of extended-spectrum beta-lactamase-producing, but aminoglycoside-susceptible, Klebsiella pneumoniae strains in our hospital over an 8-month period, by using two genotypic markers. DESIGN: Ribotyping (using two endonucleases) and randomly amplified polymorphic DNA analysis (RAPD; using two different 10-mer primers) were applied to the epidemiological typing of clinical K pneumoniae isolates from stools, ileal fluid, or urine of hospitalized children. SETTING AND PATIENTS: The surgical intensive-care ward (S1: 9 patients, 17 isolates), surgical unit (S2: 2 patients, 2 isolates), and gastroenterology ward (GE: 1 patient, 1 isolate) of the Robert Debré Hospital of Paris, France. RESULTS: Ribotyping of the 20 clinical isolates, the type strain of the species, and two epidemiologically unrelated isolates with EcoRI and HindIII revealed 6 and 5 different patterns, respectively. Six ribotypes were identified by using these two enzymes. RAPD generated 6 distinct patterns, in complete agreement with ribotyping. Our genotypic results showed that 11 patients from wards S1, S2, and GE harbored genotypically related strains, suggesting nosocomial transmission and cross-colonization between and within the three wards. CONCLUSIONS: Ribotyping and RAPD appear to be reliable methods for distinguishing K pneumoniae strains. The spread of one strain of K pneumoniae in different units of our hospital was demonstrated by both methods. However, RAPD has the advantage of simplicity and rapidity conferred by polymerase chain reaction.