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D Jan

Publications and source records attributed to D Jan.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Genetics of Hirschsprung disease].

Hirschsprung's disease (HD) is one of the commonest gastrointestinal malformations, as it affects one child out of 5,000 births. It classically induces severe neonatal intestinal obstruction requiring surgical treatment which currently ensures a favourable prognosis for most of the affected children. Although the great majority of cases are sporadic, the existence of familial forms (10% of cases) has allowed localization and then identification of an autosomal dominant gene on chromosome 10, the RET proto-oncogene, responsible for 50% of familial forms and 15% of sporadic cases. A second gene has been recently localized on chromosome 13, the endothelium beta receptor (EDNRB) gene. Two homozygous mutations of the EDNRB gene have been identified in two consanguineous families, in which HD is associated with Waardenburg's syndrome (WS). Other heterozygous mutations have been identified in patients presenting with isolated HD and an 5% of cases of HD can be considered to present mutations of this gene. Finally, the authors have recently identified a mutation of the endothelium gene 3 (EDN3), one of the EDNRB ligands in a patient presenting with a combination of HD and WS. This mutation, present at the homozygous state in this patient, is predictive of complete absence of EDN3 protein: this is therefore the third known gene responsible for HD.

Drosophila Proteins↗
PubMed1996

[Value of cyclosporine in the treatment of the recurrence of nephrosis after renal transplantation].

From May 1992 to December 1994, 14 children with end stage renal failure secondary to steroid-resistant idiopathic nephrotic syndrome received a cadaver kidney graft. Immediate recurrence of the nephrotic syndrome occurred in four patients. In the four patients, a complete remission was observed shortly after the start of intravenous cyclosporin; two children received in addition methylprednisolone pulses for secondary rejection. Two children were still protein-free 9 and 15 months after transplantation. In the third patient, proteinuria relapsed after 9 months of complete remission and persisted in spite of the reintroduction of intravenous cyclosporin. The fourth graft was lost at 3.5 month from irreversible rejection. The creatinine clearance of the 3 functioning grafts was respectively: 73, 76 and 92 ml/mn/1.73 m2 16, 10 and 15 months after transplantation. Intravenous cyclosporin started shortly after the recurrence, maintaining blood levels between 200 and 300 ng/ml, may induce a remission in recurrent nephrotic syndrome after renal transplantation in childhood.

Child, Preschool↗
PubMed1995

Liver transplantation in two cases of propionic acidaemia.

Orthotopic liver transplantation (OLT) was performed in two patients with propionic acidaemia, a 7-year-old boy and a 9-year-old girl, diagnosed with a severe neonatal form with high risk of metabolic decompensation. In both cases the metabolic liver functions recovered within the 12 postoperative hours; no clinical symptoms of propionic acid toxicity, metabolic acidosis, severe hyperammonaemia, hyperglycinaemia or haematological abnormalities were observed. In both cases insulin-dependent diabetes mellitus occurred early after OLT (persisting in the boy's case). Severe post-transplantation complications were observed (acute rejection and CMV infection in both patients) which did not trigger metabolic decompensation. The boy developed chronic rejection and vanishing bile duct syndrome due to incomplete hepatic arterial thrombosis. He required permanent in-patient care with chronic hyperammonaemia and neurological sequelae involving the basal ganglia and died 15 months after OLT. The girl left hospital after 2 months and is presently leading a normal life with almost no dietary protein restriction (40 g protein per day). Urinary urea excretion and daily protein intake increased after liver transplantation. Propionyl- and tiglylglycine disappeared immediately after OLT. Urinary methylcitrate and 3-hydroxypropionate remained at concentrations corresponding to those before OLT. However, the total of all characteristic metabolites of organic acid analysis was reduced to 50-60% of the values before OLT in both patients. Propionylcarnitine was still detected at significant concentrations. Plasma odd-chain fatty acid concentrations decreased continuously after OLT only in the girl's case. Tissue of both transplanted livers showed increased odd-chain fatty acid concentrations 9 and 15 months after OLT, respectively, in both patients. We consider that at present OLT should only be performed in severe forms of propionic acidaemia.

Acidosis↗
PubMed1995

Small bowel transplantation in children: an immunohistochemical study of intestinal grafts.

Seven children with short bowel syndrome underwent small bowel allografting. Episodes of early rejection were observed in five patients who received a graft from paediatric or adult donors but not in two patients who received a neonatal graft. This study aimed, firstly, to define immunohistochemical parameters accompanying rejection and, secondly, to compare immunohistochemical parameters in neonatal grafts with those in grafts from older donors. An immunohistochemical analysis was performed on 85 intestinal biopsy specimens taken for monitoring the transplant. Acute histological rejection was associated with pericryptic infiltrates of CD3+TcR alpha beta + T cells containing clusters of CD8+ cells, numerous CD25+ cells, and increased numbers of CD68+ macrophages. These changes were associated with the appearance of major histocompatibility (MHC) class II antigens on crypt enterocytes and with an appreciable increase in the expression of E-selectin on mucosal endothelial cells. Immunohistochemistry was useful in predicting rejection by showing the appearance of pericryptic CD25+ T cells 48 hours before the first histological lesions of crypt necrosis. Comparison of neonatal grafts with grafts from older donors did not show any significant difference in the density of CD68+ macrophages or in the endothelial expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, or E-selectin. In contrast to grafts from older donors, however, neonatal grafts did not express MHC class II antigens on epithelial cells and contained very low numbers of intraepithelial lymphocytes. These data indicate, firstly, that immunohistochemistry is useful for monitoring intestinal transplants and, secondly, that the better clinical tolerance of neonatal allografts may be related to the lower immunogenicity of the neonatal epithelium.

CD3 Complex↗
PubMed1994

Biofeedback re-education of faecal continence in children.

The purpose of this prospective study was to see if pretreatment anorectal motility can predict successful correction of faecal incontinence with biofeedback. Forty-seven consecutive children, aged 5 to 18 years, were treated. They had been treated for idiopathic constipation with faecal impaction, but had remained incontinent (n = 15), had been operated for congenital anorectal malformations of high (n = 19) or low (n = 2) type, or had a number of organic congenital pelvic abnormalities (n = 11). This consecutive series represents our entire experience with biofeedback for faecal incontinence, in the period from January 1 1983 to December 31 1989. In each patient, at the first session, anorectal manometry was performed. Resting pressures in the rectum, upper anal canal and lower anal canal were measured. The threshold of rectal sensation during distension, the maximal pressure during voluntary sphincteric contraction and the time to half decrease of sphincteric pressure because of muscular fatigue were also noted. The patient was then asked to make a voluntary sphincteric contraction, while the rectum was being distended with the volume at threshold for rectal sensation. In subsequent sessions, the rectum was also distended but without warning the patient, who was congratulated when he or she contracted the sphincter immediately after onset of rectal distension. Full continence was the criterion used to classify re-education as a success. Improvement or no change in continence was considered as failure of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Long segment and short segment familial Hirschsprung's disease: variable clinical expression at the RET locus.

Hirschsprung's disease (aganglionic megacolon, HSCR) is a frequent condition of unknown origin (1/5000 live births) resulting in intestinal obstruction in neonates and severe constipation in infants and adults. In the majority of cases (80%), the aganglionic tract involves the rectum and the sigmoid colon only (short segment HSCR), while in 20% of cases it extends toward the proximal end of the colon (long segment HSCR). In a previous study, we mapped a gene for long segment familial HSCR to the proximal long arm of chromosome 10 (10q11.2). Further linkage analyses in familial HSCR have suggested tight linkage of the disease gene to the RET protoncogene mapped to chromosome 10q11.2. Recently, nonsense and missense mutations of RET have been identified in HSCR patients. However, the question of whether mutations of the RET gene account for both long segment and short segment familial HSCR remained unanswered. We have performed genetic linkage analyses in 11 long segment HSCR families and eight short segment HSCR families using microsatellite DNA markers of chromosome 10q. In both anatomical forms, tight pairwise linkage with no recombinant events was observed between the RET proto-oncogene locus and the disease locus (Zmax = 2.16 and Zmax = 5.38 for short segment and long segment HSCR respectively at 0 = 0%) Multipoint linkage analyses performed in the two groups showed that the maximum likelihood estimate was at the RET locus. Moreover, we show that point mutations of the RET proto-oncogene occur either in long segment or in short segment HSCR families and we provide evidence for incomplete penetrance of the disease causing mutation. These data suggest that the two anatomical forms of familial HSCR, which have been separated on the basis of clinical and genetic criteria, may be regarded as the variable clinical expression of mutations at the RET locus.

Chromosome Mapping↗
PubMed1993

Congenital cystic adenomatoid malformation of the lung: prenatal management and prognosis.

Thirty-two cases of congenital cystic adenomatoid malformation of the lung diagnosed antenatally are reported. Antenatal diagnosis has made it possible to document the progress of the condition in utero and the postnatal prognosis. It has been possible to advise on termination and intrauterine intervention, to counsel the parents, and to plan arrangements for delivery and postnatal care among obstetricians, neonatologists, and pediatric surgeons. According to Stocker's classification there were 12 cases of type I, 15 of type II, and 5 of type III. Five pregnancies were terminated. Antenatal drainage of a cyst was performed in four patients with two survivors. Thirteen babies showed relative regression of the cyst as pregnancy progressed. After delivery the extent of the cystic malformation was assessed by chest x-rays and computed tomography scanning in 25 and angiography in 6. Treatment consisted of observation in 4, embolization in 2, operation as an emergency in 3, and electively around 4 months in 15.

Cystic Adenomatoid Malformation of Lung, Congenita↗
PubMed1992

Pheochromocytoma in children: 15 cases.

Pheochromocytoma is an uncommon tumor in childhood; nevertheless, 20% of all pheochromocytomas are found in the pediatric population. Fifteen children have been treated in our institution from 1962 to 1990. One percent of patients referred over the same period for investigation of high blood pressure were found to have a pheochromocytoma. The majority of patients have hypertension. It varies in intensity and is paroxysmal in about half the patients. Many pediatric cases of unilateral, bilateral, extra-adrenal, familial, and recurrent pheochromocytomas have been reported. We reviewed our 28 years experience with this tumor and concentrated on the diagnosis, the preoperative and operative management, and the occurrence of the multiple endocrine neoplasia syndromes.

Adolescent↗