Biomedical subjects

Y Aigrain

Publications and source records attributed to Y Aigrain.

At least 73 records · Page 4Linked to original sources

PubMed1998

CD44 variant expression in inflammatory colonic mucosa is not disease specific but associated with increased crypt cell proliferation.

AIMS: A recent study reported increased epithelial expression of CD44 variants in ulcerative colitis (UC) compared with Crohn's disease (CD). However, the use of CD44 expression for diagnostic purposes in inflammatory bowel disease has been controversial, and the meaning of the appearance of CD44 variants in epithelial colonic cells remains unknown. We investigated the relationship between CD44 isoform expression and crypt cell proliferation in paediatric colitis. METHODS AND RESULTS: The expression of CD44v3, CD44v6, and MIB1 (proliferation marker) was studied by immunohistochemistry on surgical colonic samples of UC (n = 13), CD (n = 10), colostomy resections with non-specific mucosal inflammation (NSMI) (n = 3), and normal controls (N = 5). The proliferation index (% of MIB1 positive cells) was assessed in both v6 positive and v6 negative crypts. Epithelial expression of CD44v3 and v6, negative in normal controls, was variable and focal in colitis. No preferential expression of CD44 variants was found in UC. The proliferation index was dramatically increased in v6 positive crypts compared with v6 negative crypts in UC, CD and NSMI. CONCLUSIONS: These data suggest that CD44 variant staining is not a useful marker for distinguishing paediatric UC from CD, and that CD44v6 expression in the inflamed colonic mucosa is not disease specific but is related to crypt cell proliferation.

Antigens, Nuclear↗

PubMed1998

Laparoscopic renal surgery via a retroperitoneal approach in children.

PURPOSE: Laparoscopic procedures are still not widely performed by pediatric urologists due to operative time and costs as well as the lack of indications and, thus, the lack of sufficient surgeon experience. We report our experience with the retroperitoneal approach using special inexpensive methods for various indications in children. MATERIALS AND METHODS: From 1994 to 1997 we performed 42 retroperitoneal laparoscopic procedures in 41 children with a mean age of 4 years, including 31 nephrectomies, 8 partial nephrectomies, 2 renal cystectomies and 1 pyelolithotomy. A total of 13 patients were younger than 1 year. Followup ranged from 6 months to 3 years. RESULTS: Mean operative time was 104 minutes (range 35 to 150) for nephrectomy, 153 (range 90 to 210) for upper pole nephroureterectomy, 135 for pyelolithotomy and 60 for renal cystectomy. Average postoperative stay was 2 days. Conversion was required in 2 cases of partial nephrectomy due to unidentified polar vessels, including 1 involving duodenal perforation. CONCLUSIONS: The indications for retroperitoneal laparoscopy are expanding with the experience of the surgical team. The retroperitoneal approach provides a technique comparable to that of conventional renal surgery.

Adolescent↗

PubMed1998

Postoperative outcome of Crohn's disease in 30 children.

BACKGROUND: Thirty children operated on for Crohn's disease (CD) were reviewed (1975-1994). The aim of the study was to assess their postoperative outcome. PATIENTS: 19 boys and 11 girls, aged 15.3 (2) years (range 11.3-20) at surgery were studied. RESULTS: Surgical indications were acute complications of CD and chronic intestinal illness. Six months after surgery, 11 of 12 patients had been weaned off steroids, and 22 of 23 patients were weaned off nutritional support; 17 patients without recurrence had a mean (SD) weight gain of 2.1 (8) kg and a height gain of 3.36 (3) cm. During 3.1 (2.7) years follow up, 12 patients (40%) had a recurrence of the disease after 19.4 (14) months (means (SD)): supra-anastomotic recurrence (six), severe perianal disease (two), and chronic illness (four). Six of 14 patients who were treated with mesalazine (13) or azathioprine (one) had recurrences. The postoperative recurrence rate was 50% at two years. CONCLUSION: Surgical treatment modifies the immediate outcome of severe or complicated CD, but does not prevent recurrence, despite localised resection or prophylactic postoperative treatment. Extension of the disease before surgery seems to be a major risk factor for postoperative recurrence in children.

Adolescent↗

PubMed1998

Definitive treatment of Hirschsprung's disease with a laparoscopic Duhamel pull-through procedure in childhood.

The Duhamel abdominoperineal pull-through is the authors' preferred treatment for children with Hirschsprung's disease (HD). Advances in instrumentation and technique now make laparoscopic correction possible. This procedure was successfully performed in six children aged 5 weeks to 6 years. No colostomy was performed before or after the Duhamel procedure. The technique and its potential role in the treatment of HD are discussed.

Child, Preschool↗

PubMed1998

[Urology and nuclear medicine in children. Experience from a series of 1200 renal scintigraphies].

During the last 4 years, we have performed 1200 renal scintigraphies in children under the age of 6 years: 57% of dynamic renal scintigraphies using MAG3 for antenatally diagnosed uropathies (mainly pelvic dilatations and megaureters), 36% of static renal scintigraphies using DMSA for renal sequelae of pyelonephritis with or without vesicoureteric reflux, and 6% of direct isotope cystography for follow-up of vesicoureteric reflux. Renal scintigraphy, which provides low radiation hazards (1 mSv), is now a major imaging modality for paediatric urinary tract disease.

Child, Preschool↗

PubMed1998

[First-line vesico-psoas hitch ureteroneocystostomy for primary obstructive megaureter].

Between 1989 and 1997, 23 children with primary obstructive megaureter underwent surgical repair, routinely using a vesico-psoas hitch ureteroneocystostomy. Ten of them had a antenatal diagnosis. Mean postoperative follow-up was 3 years. No postoperative obstruction and no vesicoureteric reflux occurred. Assessment of renal function on the operated side showed improvement in 7 cases and stabilization in all other cases. No bladder dysfunction was observed. Vesicopsoas hitch is an advantageous procedure in this indication. It is almost always unnecessary to perform ureteral tailoring and its specific complications can be avoided. Psoas hitch is easily performed in infants and young children and this technique is particularly appropriate in the subgroup of patients with antenatal diagnosis.

Child, Preschool↗

PubMed1998

[Ureteropyelostomy for obstructed duplicated ureter an easy and reliable operation in infants].

AIM: Ureteropyelostomy is one of the surgical options to treat obstructed duplicated ureter. We retrospectively analysed the results of this procedure in a group of young children with prenatal diagnosis. MATERIAL AND METHODS: Between 1992 and 1996, 11 children underwent ureteropyelostomy for obstructed functioning duplicated ureter using the following procedures. 7 cases were revealed by prenatal ultrasound and 4 by acute pyelonephritis; an ureterocele was identified in 7 cases. The mean age at surgery was 6 months for the whole group (3-46 weeks), while in the subgroup of prenatal diagnosis, it was 8 weeks (3-9 weeks). The follow-up ranged from 6 months to 4 years. RESULTS: There were no postoperative complications. None of the anastomoses needed revision, and the conserved segments maintained their functioning appearance, on follow-up. 3 children needed a subsequent ureterovesical reimplantation for urinary tract infections due to reflux in the lower segment ureter. DISCUSSION: Ureteropyelostomy is of great interest for the management of the obstructed dilated upper pole ureter revealed by prenatal diagnosis. This specific group of children needs early management to avoid septic complications and ureteropyelostomy is an easy and reliable method at this young age.

Humans↗

PubMed1998

[Surgical aspects of renal transplantation in children].

Review of a series of 90 renal transplantations performed in 86 children revealed 3 cases of early or late mortality and 28 cases of major surgical complications, predominantly vascular (13 cases) and urological complications (12 cases). The time to onset, the diagnosis and the management of these complications are reviewed. This study again emphasizes the importance of graft selection (donor age) and the value of living related donor renal transplantation.

Adolescent↗

PubMed1998

[Management of Hirschsprung's disease during the neonatal period].

Hirschsprung's disease is one of the common est causes of neonatal intestinal obstruction. Despite progress in the identification of genetic mutations, the pathogenesis of Hirschsprug's disease is not completely resolved. The management consists of septic complications of treatment, and a variable "pull-through" procedure, immediately or at a later date. Long-term follow-up is an important component of patient care.

Colon↗

PubMed1997

Highly differentiated teratoma and fetus-in-fetu: a single pathology?

A case of sacrococcygeal teratoma is presented with characteristics of fetus-in-fetu. This pseudo-fetus presented a rudimentary single cavity heart, which beat at a different rate to that of the affected infant. X-ray examination showed no spinal column. This case confirms that fetus in fetu can be a remarkably complex, well-differentiated, highly organized teratoma.

Amnion↗

PubMed1997

Down-regulation of CD95 (Fas/Apo-1) in the epithelia of adenovirus-infected appendices.

AIMS: Adenoviral inclusions are commonly seen in appendices from infants with intussusception. They are associated with focal epithelial budding and less frequently with epithelial shedding. These morphological changes could depend on the opposing effects of adenoviral gene products on CD95-mediated apoptosis. METHODS AND RESULTS: Appendices from intussusceptions with viral inclusions (n = 4) and normal appendices (n = 10) were studied by immunochemistry with anti-adenovirus, anti-CD95 and anti-HLA-DR antibodies. Apoptosis was studied by the TUNEL method. The mucosa of normal appendices contained no adenoviral protein. CD95 was present in all epithelial cells except Paneth cells. HLA-DR was absent in epithelial cells and apoptosis was seen only in germinal centres and in a few surface epithelial cells. The epithelium of appendices from intussusceptions contained nuclear inclusions labelled with anti-adenovirus antibody, always found in the epithelial buds. The epithelial CD95 pattern was drastically altered in adenovirus-infected appendices. CD95 was absent from the budding foci. In these foci, HLA-DR was overexpressed. There was also increased epithelial apoptosis in areas remote from those lacking CD95 antigen. CONCLUSIONS: The appearance of epithelial budding or shedding in appendices from intussusception could be due to focal in situ differences in the expression of adenoviral genes.

Adenoviridae Infections↗

PubMed1997

Cystic dysplasia of the testis with ipsilateral renal agenesis. A case report and review of the literature.

While cystic dysplasia of the testis is rare, the awareness of the benign and malformative nature of this lesion is important to consider among other cystic testicular and para testicular lesions, first neoplasm. Its sonographic appearance and the recognition of simultaneously occurring renal anomalies should allow for prompt recognition in children with scrotal swelling or testicular enlargement. We describe a 10-year-old boy with right testicular swelling who underwent orchiectomy for cystic dysplasia of the testis.

Abnormalities, Multiple↗

PubMed1997

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.

Cross Infection↗

PubMed1997

In situ Rantes and interferon-gamma gene expression in pediatric small bowel Crohn's disease.

BACKGROUND: Rantes (regulated upon activation, normal T cell expressed and secreted) is a chemotactic cytokine for memory T lymphocytes, monocytes, and eosinophils. The cytokine interferon-gamma (IFN-gamma) plays a key in the immune response. Their distributions and possible roles in the selective accumulation of inflammatory cells in Crohn's disease (CD) were examined by determining the expression of Rantes and IFN-gamma genes in patients with CD using in situ hybridization (ISH) on frozen and paraffin-embedded tissue sections. METHODS: Intestinal and mesenteric lymph node samples from 9 children who had undergone ileal resection for CD were examined for the presence of epithelioid-giant cell granulomas (EGCG) and Rantes and IFN-gamma messenger RNA (mRNA). Normal pediatric intestine (n = 5) and lymph nodes (n = 2) served as controls. RESULTS: Many cells in all CD specimens in the epithelial compartment, lamina propria, and the EGCG gave positive signal with the Rantes antisense probe. Labelled cells were identified on paraffin sections as lymphocytes, macrophages, and epithelioid cells. There were Rantes-positive cells in the control intestinal tissues, but many Rantes-positive cells in control lymph nodes that showed follicular hyperplasia. IFN-gamma-positive cells were present in all CD ileal and lymph node specimens, predominantly in close contact with EGCC. No positive signal was obtained with the Rantes and IFN-gamma sense control probes. CONCLUSIONS: These findings suggest that Rantes and IFN-gamma contribute to the selective accumulation of macrophages and memory T helper lymphocytes inside the granulomas and inflammatory infiltrates that are characteristic of CD.

Adolescent↗

PubMed1997

[Adenovirus and intranuclear inclusions in the appendix in children with acute intussusception].

One hundred and five appendices removed at the time of surgical reduction of intussusception in children were studied by light microscopy after routine procedures to search for aetiological factors involved in intussusception. Normal pediatric appendix specimens served as controls (n = 30). Light microscopic examination showed viral inclusions in epithelial cells in 48 of 105 appendices (45%) from the cases of intussusception. No viral inclusion was observed in controls. Immunohistochemistry performed on 21 appendices from intussusception with a monoclonal antibody against adenovirus showed intranuclear positivity in all appendices with viral inclusions. Viral inclusions seen in epithelial cells of appendices from cases of intussusception are caused by virus and in particularly by adenovirus. The etiological factors involved in intussusception without viral inclusion in appendix remain unknown.

Acute Disease↗

PubMed1996

[Primary vesico-ureteral reflux. Current data and perspectives].

Primary vesicoureteral reflux is a frequent condition threatening the renal parenchyma. This severe disease can lead to renal dysplasia and scarring. When revealed by acute urinary tract infection, parenchymal damage has, in most cases, already occurred so medical or surgical care comes too late. Ideally, the population should be screened at birth for vesicoureteral reflux, but unfortunately, no biological test is yet available. At the present time, it would be reasonable to propose cystography to "at risk" populations, first in newborns with pyelocaliceal dilation detected antenatally then in siblings of patients treated for vesicoureteral reflux. Bladder dysfunction, also often associated with primary vesicoureteral reflux, should be identified early and treated. Finally there are several, often opposing, patterns of clinical expression. Antenatally detected vesicoureteral reflux predominates in the male population. Congenital parenchymal lesions, even in the absence of urinary tract infection, are associated with a small capacity hyperactive bladder. Primary vesicoureteral reflux in the school-age girl is associated with post-infectious renal scarring and with a large bladder incompletely emptied during micturition. Early diagnosis, screening of high-risk populations and prevention of infection together with better management of bladder dysfunction should help reduce the incidence of parenchymal damage due to primary vesicoureteral reflux.

Anti-Infective Agents, Urinary↗

PubMed1996

[Contribution of endosonography to the diagnosis and follow-up of pediatric gastric neurofibroma revealing von Recklinghausen's disease].

BACKGROUND: Gastrointestinal involvement in von Recklinghausen's disease (RD) is rare during childhood; its symptoms are late and its prognosis is poor, related to local recurrence and risk of malignant transformation. CASE REPORT: A 13 year-old boy was admitted for hematemesis revealing gastric ulcer. A second episode of hematemesis led to identify a sessile gastric tumor in this patient having numerous skin café-au-lait spots. Recurrent bleeding required laparotomy that showed diffuse infiltration into the anterior gastric wall: histological examination of the excised piece showed characteristic features of neurofibromatosis. The patient was not compliant to the endosonographic survey so that a symptomatic relapse led to total gastrectomy: histological examination did not show malignant transformation. CONCLUSION: Endoscopy is a major tool for identifying gastrointestinal localization of RD but endosonography is necessary to precise the extent of the tumor.

Adolescent↗

PubMed1996

Resting energy expenditure before and after surgical resection of gut lesions in pediatric Crohn's disease.

In pediatric Crohn's disease (CD), resection of gut lesions is necessary to remove stenoses and when frequent relapses occur despite nutritional support and medical treatment. After surgery, improved nutritional status and accelerated growth usually follow increased nutritional intake and lower doses of steroids. The aim of this study was to compare energy balance before and after surgery while nutritional intake and steroid therapy were unchanged. Eleven patients, aged 14.5 +/- 2.5 years and with mildly active CD, were explored 1 week before and 1 month after gut resection for stenosis (n = 7) and medical treatment failure (n = 4). Eleven matched children participated in the study as controls. Disease activity was assessed by the Pediatric Crohn's Disease Activity Index and serum orosomucoid concentration. Resting energy expenditure (REE) was measured by indirect calorimetry, and fat-free body mass (FFM) was measured by anthropometry. The patients' mean REE decreased from 46.6 +/- 10.5 kcal/kg FFM/day before surgery to 42.6 +/- 10.3 kcal/kg FFM/day after surgery, while the controls' mean REE was 39 +/- 7 kcal/kg FFM/day (analysis of variance, p = 0.02). After surgery, body weights were not significantly different, but the mean protein oxidation rate was reduced and arm muscle area was increased. Changes in REE per kilogram of FFM per day were not correlated with changes in orosomucoid serum concentrations (r2 = 0.35; p = 0.4). In conclusion, in children with mildly active CD, while nutritional intake and steroid therapy were maintained at preoperative levels, a significant decrease in REE and improved nitrogen utilisation were observed 1 month after resection of the CD gut lesion. This finding suggests better use of energy substrates when CD lesions are removed.

Adolescent↗