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Biomedical subjects

Y Aigrain

Publications and source records attributed to Y Aigrain.

At least 37 records · Page 2Linked to original sources

Population pharmacokinetics of ciprofloxacin in pediatric and adolescent patients with acute infections.

The aim of the present study was to characterize the population pharmacokinetics of ciprofloxacin in patients with and without cystic fibrosis ranging in age from 1 day to 24 years and to propose a limited sampling strategy to estimate individual pharmacokinetic parameters. Patients were divided into four groups according to the treatment schedule. They received ciprofloxacin by intravenous infusion (30 min) or by the oral route. The number of samples collected from each patient ranged from 1 to 12. The population parameters were computed for an initial group of 37 patients. The data were analyzed by nonlinear mixed-effect modeling by use of a two-compartment structural model. The interindividual variability in clearance (CL) was partially explained by a dependence on age and the patient's clinical status. In addition, a significant relationship was found between weight and the initial volume of distribution. Eighteen additional patients were used for model validation and evaluation of limited sampling strategies. When ciprofloxacin was administered intravenously, sampling at a single point (12 h after the start of infusion) allowed the precise and accurate estimation of CL and the elimination half-life, as well as the ciprofloxacin concentration at the end of the infusion. It should be noted that to take into account the presence of a lag time after oral administration, a schedule based on two sampling times of 1 and 12 h is needed. The results of this study combine relationships between ciprofloxacin pharmacokinetic parameters and patient covariates that may be useful for dose adjustment and a convenient sampling procedure that can be used for further studies.

Acute Disease↗

Do prognostic factors exist for total colonic aganglionosis with ileal involvement?

BACKGROUND/PURPOSE: Total colonic aganglionosis with ileal involvement is estimated at 1 case in 50,000 living births. This pathology has a very variable prognosis, and patients often need long-term parenteral nutrition. The aim of this study is to define prognostic factors for this disease. METHODS: This is a retrospective study from 1980 to 1999, based on 26 cases of total colonic aganglionosis with ileal involvement. The authors analyzed birth term, sex, birth weight, ileal involvement in centimeters, delay to correct level enterostomy, the total parenteral nutrition duration, and the need for constant rate nutritional assistance. The authors studied the following items: Weight, height, complications, clinical state, and nutritional issues. The statistic test is: LOG RANK (analysis of censored data and comparison of survival diagram). RESULTS: The only prognostic factor is the length of ileal involvement. All the children with ileal involvement less than 50 cm, except for 2, did not need long-term nutritional assistance; for those with ileal resection over 50 cm, long-term nutritional assistance was needed. Total colonic aganglionosis is a very serious illness (2 children had a small bowel transplantation, and 2 are waiting for one). The prognosis is even worse when associated with a polymalformation syndrome (50% of the children died). CONCLUSION: The major prognostic factor is the length of small bowel not involved in the total colonic aganglionosis.

Adolescent↗

Esophageal ligature in experimental gastroschisis.

BACKGROUND/PURPOSE: Recently, the authors have shown that in human fetuses suffering from gastroschisis, there is an amniotic fluid inflammatory response and that amniotic fluid exchange designed to disrupt the inflammatory loop seems to have a favorable impact on outcome. The authors, therefore, designed in the fetal sheep a model of gastroschisis in which amnioinfusion significantly improved the deleterious process. They hypothesized that regurgitation and presence of digestive enzyme in the amniotic fluid triggers and maintains the process of inflammation. METHODS: To test this hypothesis, the authors used their model of gastroschisis in the fetal lamb combined with esophageal ligation and compared it with gastroschisis with or without amnioinfusion. RESULTS: Of 34 fetuses operated on at midgestation (days 70 through 80), 11 died in utero or were stillborn, 8 had gastroschisis and amnioinfusion, 8 had gastroschisis and no amnioinfusion, and 7 had gastroschisis and esophageal ligation. There were 9 control fetuses. Fetuses were killed at day 145 by cesarean section. Extraabdominal bowels with fibrous peel were processed for histologic examination. Thickness of bowel muscularis (micrometers) was 82.7 +/- 19 for controls, 159 +/- 56 for the nonamnioinfused fetuses, 126 +/- 21 for the amnioinfused fetuses (P =.001), and 240 +/- 225.8 for fetuses with esophageal ligature combined with gastroschisis. The same results were obtained for thickness of serous fibrosis and plasma cell infiltration. Assay of amniotic fluid ferritin, lipase, and protein showed that only amnioinfusion lowered ferritin and protein to levels similar to those of controls, thus, illustrating its preventive effect on inflammation and that esophageal ligature did not prevent digestive enzyme presence in the amniotic fluid. CONCLUSION: In this model of gastroschisis in the fetal sheep, ligature of the esophagus, which was supposed to protect the extruded bowel by preventing oral regurgitation of digestive enzymes and by creating a relative hydramnios, did not improve the inflammatory and deleterious process, which is best prevented by amnioinfusion.

Amniotic Fluid↗

Follow-up of partial splenectomy in children with hereditary spherocytosis.

BACKGROUND/PURPOSE: The aim of this report is to study the short- and long-term consequences of partial splenectomy (PS) in hereditary spherocytosis (HS). METHODS: The authors reviewed the files of 5 children who underwent PS from 1993 to 1998. The data collected included clinical presentation, age, gender, indication for the operation, radiographic examination, need for blood transfusion and hematologic values, description of surgical procedure, and early- and late-occurring complications. RESULTS: From 1993 to 1998, 5 children from one year, 9 months to 7 years of age underwent PS. Indications were hypersplenism and severe anemia. The average age at the time of the operation was 3 years, 5 months. The 2 youngest children (one year, 9 months and 2 years old) needed a second operation because of the recurrence of hypersplenism. CONCLUSIONS: Subtotal splenectomy seems to preserve the immune role of the spleen and can reduce the need for blood transfusion. But PS is associated with a regrowth of the splenic remnant in children suffering from chronic hemolysis with hypersplenism and seems to be effective for a relatively short period only, especially in young children. Thus, a second operation to perform a total splenectomy can be necessary. The decision to perform a PS on young children with HS as an alternative to total splenectomy with appropriate preoperative vaccination and postoperative prophylactic antibiotics therefore should be weighed carefully, keeping in mind, however, the benefit of postponing total splenectomy in these patients.

Blood Transfusion↗

The effect of endoscopic injections of dextranomer based implants on continence and bladder capacity: a prospective study of 31 patients.

PURPOSE: A prospective study was conducted to assess the efficacy of dextranomer based implants as a new bulking agent for endoscopic treatment of pediatric structural incontinence. MATERIALS AND METHODS: A total of 33 children and adolescents 5 to 18 years old with severe incontinence due to sphincteric incompetence (exstrophy-epispadias in 13, neuropathic bladder in 16, bilateral ectopic ureters in 4) were enrolled in the study. All but 1 patient wore diapers. Preoperative evaluation consisted of medical history, pad test, urine culture, urinary tract ultrasound and videourodynamics. This evaluation was repeated 6 months and 1 year after treatment and then on a yearly basis. Of the patients 14 had 2 and 1 had 3 treatment sessions to achieve a definitive result. At each evaluation the patient was considered cured-dryness interval of 4 hours confirmed by pad test, significantly improved-minimal incontinence requiring no more than 1 pad a day with less than 10 gm. leakage during pad test; and no further treatment required, and treatment failure-no significant improvement. Videourodynamics were mainly useful to study the evolution of the bladder capacity, activity and compliance. Followup after the last injection ranged from 6 to 36 months (mean 18). RESULTS: The mean injected volume was 3.9 ml. (range 1.6 to 12) and the procedure lasted a mean of 30 minutes (10 to 60). In the postoperative period 2 patients had temporary dysuria and 10 had a nonfebrile urinary tract infection. At 1 month 24 of the 33 patients (73%) were dry or improved. Two patients were subsequently excluded from study for noncompliance with followup. At 6 months 17 of 31 patients (55%), at 1 year 13 of 28 (46%), at 2 years 10 of 23 (43%) and at 3 years 10 of 20 (50%) were dry or improved. Similar success occurred in cases of neuropathic bladder (57%) and exstrophy-epispadias complex (46%). Success rate of re-treated patients was 35%. Of 13 patients with a normal initial bladder capacity 3 had a bladder decompensation requiring augmentation after 6 months. Also an increase of at least 50% in capacity was observed in 12 of 18 patients with an initial small bladder. No side effect related to the substance was observed. CONCLUSIONS: Endoscopic treatment of pediatric structural urinary incontinence with dextranomer implant, a nontoxic, nonimmunogenic, nonmigrant synthétic substance, was effective after 3 years in half of our patients. It may also be beneficial for patients with small bladder functional capacity. As the success rate decreased during the first year of followup, the result observed at 1 year seems to remain stable subsequently.

Adolescent↗

[Isolated antenatal pyelic dilatation: postnatal follow-up and care for vesico-ureteral reflux].

OBJECTIVE: To assess the risk of aneuploidia in case of isolated antenatal pyelic dilatation and to detail urological care for these children. METHODS: Prenatal and postnatal follow-up was analyzed in 350 cases. RESULTS: The overall rate of chromosome anomalies was 1.3%. Trisomy 21 was found alone in one case (0.3%). The sex ratio was 26% girls and 74% boys. Vesico-ureteral reflux was similar in both sexes (13%). CONCLUSION: The question of proposing karyotyping in case of isolated pyelic dilatation remains unsolved because minimal subjective signs such as slightly excessive amniotic fluid can completely change the assessment of the risk of aneuploidia. The frequency of postnatal vesico-ureteral reflux associated with prenatal pyelic dilatation warrants complete prenatal ultrasound screening.

Adult↗

Definitive treatment of extended Hirschsprung's disease or total colonic form.

BACKGROUND: Between December 1990 and March 1999, five laparoscopic Duhamel pull-through procedures for extended or total aganglionosis were performed in our department, one of which had a rectosigmoid form with a short bowel and a colonic resection due to a volvulus. METHODS: The aim of this study was to show that even when the extended form of Hirschprung's disease or anatomic difficulties such as a short bowel and anterior colonic resection are encountered, the laparoscopic approach is possible and total colectomy is feasible. The procedure has been described previously. We used one camera port and three working ports. The sigmoid, transverse, and right colon up to the last ileal cove were mobilized laparoscopically. A standard posterior ileo-anal anastomosis was performed, and an endo-GIA stapler was used for the anterior anastomosis. RESULTS: A total of five patients underwent laparoscopic surgery for Hirschprung's disease. There were three total colonic forms, one rectosigmoid form with a short bowel and colon resection attributed to a volvulus, and one transverse variant that required a Deloyers' maneuver for the pull-through. Three of the infants required total parenteral nutrition (TPN) for an average of 49 days (range, 28-60) from diversion until the time of the definitive procedure. Only one patient did not receive TPN. Postoperatively, there were two complications-one wound infection and one hectic fever. The clinical results were good, with no soiling or stool incontinence and no constipation. CONCLUSION: The laparoscopic procedure for total aganglionosis or the extended form of Hirschprung's disease is safe, feasible, and reproducible.

Feasibility Studies↗

Mediastinal pancreatic pseudocyst in a child. A thoracoscopic approach.

Mediastinal pancreatic pseudocyst is a rare occurrence in children and may be difficult to diagnose. Internal drainage via a cystenterostomy and a simple external drainage are two of the treatment options that are currently employed. We describe the case of an 11-year-old boy with a mediastinal pseudocyst who was treated via a thoracoscopic approach using an original pulmonary exclusion. The pseudocyst disappeared in 15 days and there has been no recurrence. No adjuvant treatment was necessary. Endoscopic retrograde cholangiopancreatography (ERCP) was useful in establishing the etiology (pancreas divisum). We believe that the thoracoscopic approach is a reproducible, simple, and safe procedure for the treatment of mediastinal pseudocysts. The technique may represent a valid alternative to cystogastrostomy.

Catheterization↗

Bronchial trifurcation in a congenital pulmonary venolobar syndrome.

Congenital malformations of the tracheobronchal tree and the related arterial blood supply are a complex group of lesions in which there are abnormalities of the venous drainage and lung parenchyma. These malformations are examples of congenital pulmonary venolobar syndrome (CPVS). Tracheal trifurcation is an extremely rare anomaly associated with CPVS. We report on an unusual case of lower right extralobar sequestration connected to the trachea, plus a type I posterior laryngeal cleft, an aberrant systemic artery, and an anomalous route of the phrenic nerve. This paper discusses the place of this unusual abnormality in the spectrum of congenital bronchopulmonary vascular malformations.

Abnormalities, Multiple↗

GDNF expression in Wilms tumor.

PURPOSE: Wilms tumor or nephroblastoma is a developmental tumor of the kidney and one of the most frequent solid tumors in childhood. It derives from metanephrotic blastema and mimics nephrogenesis in a disorganized manner, offering an adequate model for study of human nephrogenesis. GDNF (glial cell line derived neurotrophic factor), a potent proliferation and survival factor of dopaminergic neurons, has recently been shown to have an early and major role in nephrogenesis. We studied the expression of GDNF in Wilms tumor. MATERIALS AND METHODS: The study included 20 patients with nephroblastoma whose age at surgery ranged from 2 months to 13 years. Expression of GDNF protein was analyzed by an immunohistochemical technique using anti-GDNF antibody. Presence of GDNF-messenger (m)RNA and receptors GFRalpha1 and GFRalpha2-mRNA was analyzed by reverse transcription polymerase chain reaction. Specimens were also studied to evaluate apoptosis, proliferation index and Bcl-2 expression. RESULTS: GDNF expression was mainly found in the epithelial cells of the most differentiated tubes, GDNF and co-receptors mRNA were found in specimens and proliferative activity was found on the same tubes as GDNF expression. Bcl-2 was expressed strongly in epithelial cells, in an intermediate fashion in the blastema and faintly in mesenchyma. Apoptosis was of low frequency in structures strongly expressing GDNF. CONCLUSIONS: We have shown that GDNF is expressed by nephroblastoma tissue of human kidneys. This expression is mainly in the differentiated epithelial component of the nephroblastoma. We have also shown that tissue strongly expressing GDNF is positively proliferative and has less apoptotic activity. We speculate that the role of GDNF may not be limited to normal nephrogenesis but may interact with other factors in the process of proliferation and apoptosis involved in nephroblastoma tumorigenesis.

Adolescent↗

[Laparoscopic splenectomy in children: experience and results].

UNLABELLED: Pediatric laparoscopic splenectomy is a relatively new surgical procedure. Advances in instrumentation and technique now make this procedure possible. Splenectomy is frequently performed in children for various hematologic and autoimmune diseases. PATIENTS AND METHODS: This article reviews the indication for splenectomy, the technique of laparoscopic splenectomy and our results. Between January 1996 and January 2000, 23 children underwent laparoscopic splenectomy. Three of them also had a concomitant cholecystectomy. Their ages ranged from three to 14 years. Nine children had hereditary spherocytosis, four were affected by sickle cell disease, three had an idiopathic thrombocytopenia and three a hemolytic disease. One patient was converted. RESULTS: Mean operative time was 170 min (range, 115-230 min). Hospital stay ranged from three to 15 days (median, 6). Five patients had complications (three pneumonia and two deep abscesses). Median follow-up was 20 months (two months to four years) without problems regarding procedure. CONCLUSION: Regarding the low complication rate for this type of patient and the advantages of a small abdominal trauma in the postoperative period, the laparoscopic approach for elective splenectomy in hematological disorders is the technique of choice.

Adolescent↗

Scintigraphic screening for renal damage in siblings of children with symptomatic primary vesico-ureteric reflux.

OBJECTIVE: To define prospectively the incidence of renal parenchymal lesions in the siblings of patients treated at one institution for primary vesico-ureteric reflux (VUR). PATIENTS AND METHODS: From January 1997 to October 1998, a prospective study including renal scintigraphy (using dimercaptosuccinic acid, DMSA) and a radionuclide cystogram was proposed systematically to the asymptomatic siblings of children treated for primary VUR. The radionuclide cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or with no renal defect. RESULTS: Fifty-five families gave informed consent, of whom 46 completed the study (eight refused secondarily and one was omitted by exclusion criteria), representing 46 symptomatic patients and 65 siblings. There were 17 siblings with VUR (26%) including two of 13 infants and 15 of 52 children aged > 18 months. One radionuclide cystogram failed. Of the 17 refluxing siblings, four had a history of symptomatic urinary tract infection; 62 of the 65 siblings had a DMSA scan, of which 56 were normal and six (10%) showed abnormalities (five asymmetrical differential function and one parenchymal defect). Only one of these six patients had VUR at the time of the evaluation and only one had a small kidney detected by ultrasonography on one side (and no VUR). There were no adverse effects associated with screening. CONCLUSION: This study confirms a significant overall incidence of VUR (26%) in the asymptomatic siblings of patients treated for primary VUR. From the results of the DMSA scan (only one sibling had a parenchymal defect), the systematic screening of asymptomatic siblings does not appear to be beneficial.

Adolescent↗

Postnatal management of cystic neuroblastoma.

Cystic adrenal neuroblastoma (NB) is highly unusual. We report two cases of cystic NB, detected antenatally and emphasize postnatal strategy management. Case 1: a right cystic mass was detected in a foetus in the 34th week of pregnancy, and checked as the same in the 36th week. Postnatal ultrasonography confirmed the presence of a growing adrenal cystic mass. MRI and MIBG scintigraphy suggested an isolated adrenal tumour, without catecholamine secretion. Surgical resection was decided upon and pathological examination confirmed the diagnosis of cystic NB. Follow-up found a recurrence at 10 months and the patient underwent excision after chemotherapy. Histology confirmed the metastatic origin from NB. Case 2: a right adrenal cystic mass was detected during pregnancy, with no regression of tumour size on postnatal US. MRI, MIBG scintigraphy, and catechol plasma and urinalysis led to the conclusion of an isolated non-secreting lesion. A right adrenalectomy was performed at 1 month. Pathologic examination diagnosed a cystic NB. We would suggest serial US examinations and early removal of any cystic mass with characteristic US signs (thick complex wall) or without regression on one month follow-up. Prenatal diagnosis may provide the best chances for neonatal excision and good prognosis.

Adrenal Gland Neoplasms↗

Elective laparoscopic cholecystectomy.

BACKGROUND: Gallbladder stones are very common in patients with sickle cell disease and are the cause of recurrent abdominal pain. Their management has been highly controversial, especially for children. Nonoperated patients and those treated on an emergency basis have a very high rate of morbidity (>50%). METHODS: We performed a retrospective review of a series of 29 homozygous SS sickle cell children who underwent laparoscopic cholecystectomy between 1991 and April 1998. RESULTS: Only in one case a conversion was necessary (early in the series). Exploration of the common bile duct was done via intraoperative cholangiography. There were no mortalities. The morbidity rate was 17%; (however, of the five patients concerned, four suffered from hyperthermia for 2 days. All of the children were improved and enjoyed resolution of their abdominal pain. CONCLUSIONS: We believe that elective laparoscopic cholecystectomy at the earliest time possible, along with correct perioperative management, is the treatment of choice for cholelithiasis in children with sickle cell disease.

Abdominal Pain↗

Situs inversus and bowel malrotation: contribution of prenatal diagnosis and laparoscopy.

The authors report 3 different cases of prenatal diagnosis of situs inversus associated with bowel malrotation. Heterotaxy existed in 2 cardiosplenic syndromes (1 left and 1 right isomerism), and 1 isolated situs inversus. Bowel malrotation was detected at birth by ultrasonography and intestinal contrast study. Patients underwent laparoscopic LADD's procedure and abdominal exploration in the neonatal period. The authors advocate neonatal screening and early surgical management of bowel malrotation in prenatally diagnosed heterotaxic syndromes.

Adult↗