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Biomedical subjects

P Tounian

Publications and source records attributed to P Tounian.

At least 19 recordsLinked to original sources
PubMed2004

Esophageal replacement in children by an isoperistaltic gastric tube: a 12-year experience.

The colonic segment is the most frequently used material for replacing the esophagus in children; however, the use of a gastric tube has become a reliable alternative operation. Since 1987, we have used an isoperistaltic gastric tube to replace the esophagus in children, and we present a series of 21 patients. Indications for operation included caustic injury (nine), esophageal atresia (eight), peptic stricture (two), congenital stricture (one), and esophageal duplication (one). There was no death or necrosis of the graft during the early postoperative period. The esophagogastric anastomosis leaked in two cases, but both of them closed spontaneously. A temporary dumping syndrome was encountered in two children. Two patients had strictures of their upper anastomosis responding to dilatations. The two patients who had a pharyngogastric anastomosis developed either intractable stricture or nonfunctioning anastomosis. One of them died 9 months later from aspiration pneumonitis. At follow-up, 16 of 21 patients could accept a normal diet (13 were entirely asymptomatic, and three suffered occasional mild dysphagia). Two patients suffered significant dysphagia (one had a durable dilation of his gastric tube), and three needed a feeding jejunostomy. Acid secretion of the gastric tube was proved in nine cases. Two patients were shown to have cervical Barrett's esophagus above the anastomosis. These findings indicate the need for lifelong endoscopic follow-up for these patients.

Child↗
PubMed2004

[Body-weight regulation in children: a key to obesity physiopathology understanding].

Body weight is regulated within a narrow, individualized range despite large daily caloric mismatches. This process which maintains a stable level of body weight is known as adipostat. Peripheral adiposity signals, mainly leptin and ghrelin, communicate the status of energy stores in the body to the hypothalamus, which in turn coordinates adaptive responses to energy imbalances via reciprocal alterations in appetite and energy expenditure. Obese individuals also display behavioral and metabolic adjustments to weight perturbations as if their adipostat attempts to maintain their elevated body-weight. Efforts to reduce the weight of obese subjects from the elevated levels they ordinarily display are frequently ineffective because their adipostat actively resists by stimulating appetite and reducing energy expenditure. These adaptive responses to weight loss may be an explanation to understand the traditional failure of obesity treatment. Strategy of directly altering the energy-regulating system may be a promising therapeutic approach.

Body Weight↗
PubMed2003

Resting energy expenditure and substrate utilisation rate in children with constitutional leanness or obesity.

BACKGROUND & AIM: The influence of energy expenditure on body weight regulation, in the absence of organic disease, has never been studied in a paediatric population covering a broad range of body weights. The aim of this study was to investigate resting energy metabolism in children with constitutional leanness, normal body weight, or common obesity. METHODS: Fourteen children with constitutional leanness, 16 children with obesity, and controls were studied. Resting energy expenditure and postabsorptive substrate utilisation rate were measured by indirect calorimetry and body composition was assessed from skinfold thicknesses. RESULTS: As compared to the predicted value calculated from the regression equation of resting energy expenditure on fat-free mass in the controls, resting energy expenditure was decreased in lean children (P=0.002), whereas no difference was found in obese children. In obese children and the overall population, fat mass was positively correlated with fat oxidation rate. In each group and in the overall population, fat oxidation rate was positively correlated to resting energy expenditure. CONCLUSIONS: Constitutionally lean children have a low resting metabolic rate, probably adaptive in nature. In obese children, resting energy expenditure is increased in proportion to the fat-free mass, and fat balance is the main determinant of energy balance. These data suggest a constitutional regulation of body weight.

Adipose Tissue↗
PubMed2001

Presence of increased stiffness of the common carotid artery and endothelial dysfunction in severely obese children: a prospective study.

BACKGROUND: Epidemiological studies suggest that obesity-induced atherosclerosis may start in childhood, but this process has never been demonstrated. We looked for arterial changes and investigated their relation to cardiovascular risk factors in obese children. METHODS: Non-invasive ultrasonographic measurements were made in 48 severely obese children and 27 controls to investigate arterial mechanics and endothelial function. Plasma lipid concentrations, indices of insulin resistance, and body composition were assessed in the obese children. FINDINGS: The obese children had significantly lower arterial compliance than the healthy controls (median 0.132 [0.022-0.273] vs 0.143 [0.112-0.237] mm(2).mm Hg; p=0.02) and lower distensibility (0.60 [0.10-1.00] vs 0.70 [0.50-1.10] mm Hg(-1).10(-2); p=0.0001). Conversely, the obese children had higher values than the controls for wall stress (3.36 [2.00-5.01] vs 2.65 [2.13-3.54] mm Hg.10(2); p=0.0001) and incremental elastic modulus (1.68 [0.72-10.8] vs 0.96 [0.64-1.47]; p=0.0001). Endothelium-dependent and independent function were also lower in the obese than in the control children. An android fat distribution was positively correlated with indices of insulin resistance and plasma triglyceride concentrations and was negatively correlated with plasma HDL-cholesterol concentration and arterial compliance. Endothelial dysfunction was correlated with low plasma apolipoprotein A-I and with insulin resistance indices. INTERPRETATION: Severe obesity in children is associated with arterial wall stiffness and endothelial dysfunction. Low plasma apolipoprotein A-I, insulin resistance, and android fat distribution may be the main risk factors for these arterial changes, which are of considerable concern as possible early events in the genesis of atheroma.

Adolescent↗
PubMed2001

[Obesity in children: a disease that risks the vital prognosis].

UNLABELLED: Drug consumption by adolescents causes social and health problem. OBJECTIVE: This prospective study was designed to examine reasons for and against using substances such as tobacco, alcohol, and marijuana and to discover whether or not motives to use drugs vary with the number of drugs used. METHOD: The participants were 886 adolescents from a suburban high school (Nancy, France), who answered a self-report questionnaire. RESULTS: The response rate was 95% (655 males and 175 females, mean age 17.5 +/- 2.5 years). The prevalence of current tobacco use, former tobacco use and never used was 40.7, 21.3 and 31.7%, respectively. For alcohol consumption, the results wre 85.8, 3.5 and 0.7% respectively and for marijuana consumption 34.4, 18.3 and 47.3%, respectively. Ecstasy had already been used by the respondens. The main reasons given by the adolescents to explain why they did or did not use these substances varied with the mumber of drugs used. CONCLUSION: This work shows an increasing deterioration of youths' social relations (with his/her parents and with him/herself) that seem to depend onthe number of drugs used. Further research is necessary to improve these results.

Adult↗
PubMed2001

Mutational analysis of melanocortin-4 receptor, agouti-related protein, and alpha-melanocyte-stimulating hormone genes in severely obese children.

OBJECTIVE: To search for mutations in melanocortin pathway elements, that is, the melanocortin-4 receptor (MC4R ), agouti-related protein (AGRP ), and (alpha-melanocyte-stimulating hormone (alpha MSH ) genes in children with severe obesity. STUDY DESIGN: Direct sequencing of the MC4R encoding sequence and single-strand polymorphism conformation analysis of AGRP and alpha MSH genes were performed in 63 severely obese children. Polymerase chain reaction (PCR) assays of restriction fragment length polymorphism were used to assess the frequency of each newly discovered mutation in 283 non-obese control subjects. RESULTS: Four dominantly inherited, heterozygous, missense MC4R mutations (Val50Met, Ser58Cys, Ile102Ser, and Ile170Val) were identified in 4 unrelated children and none of the control subjects. Expression of the obese phenotype was variable in mutation-positive family members. Clinical and laboratory features were similar in the obese children with and without an MC4R mutation. Two polymorphisms were detected in the AGRP -encoding sequence (a silent mutation in exon 1 and Ala67Thr in exon 2), with similar frequencies in the obese and control groups. No mutations were found in the alpha MSH gene. CONCLUSIONS: MC4R mutations may be a non-negligible cause of severe obesity in children with variable expression and penetrance. Mutations in AGRP and alpha MSH genes were not among the causes of obesity in our population.

Adolescent↗
PubMed2001

Omeprazole combined with amoxicillin and clarithromycin in the eradication of Helicobacter pylori in children with gastritis: A prospective randomized double-blind trial.

OBJECTIVES: The aim of this multicenter prospective, randomized, double-blind study was to assess the efficacy of the combination of omeprazole, amoxicillin, and clarithromycin (OAC) for the treatment of Helicobacter pylori gastritis in children. STUDY DESIGN: Seventy-three children with dyspeptic symptoms were included in the trial (mean age 10.8 years; range, 3.3 to 15.4). Patients were randomized to receive OAC or amoxicillin and clarithromycin (AC) for 7 days. H pylori status was assessed before and 4 weeks after eradication treatment, by use of the carbon 13-labeled urea breath test. RESULTS: In intent-to-treat analysis (n = 63), eradication rates were 74.2% (95% CI, 58.7 to 89.6) in the OAC group and 9.4% (95% CI, 0 to 19.5) in the AC group. In per-protocol analysis (n = 53), the eradication rate increased to 80% (95% CI, 64.3 to 95.7), remaining significantly higher than in AC group (10.7%; 95% CI, 0 to 22.2). Resistance of strains to clarithromycin was rare (3/39 = 7.7%) and was not associated with failure of treatment. Adverse events were reported in 24.6% of patients and remained mild. CONCLUSION: This study shows that 1-week OAC triple therapy results in successful eradication of H pylori in 75% of children with gastritis.

Adolescent↗
PubMed1999

Ischemic necrosis of bile ducts complicating Schönlein-Henoch purpura.

Gastrointestinal complications of Schönlein-Henoch purpura are frequent and sometimes severe. However, there seem to be no reports of liver involvement. A child is described in whom Schönlein-Henoch purpura was complicated by bile duct lesions, resulting in biliary cirrhosis and requiring liver transplantation. At surgical removal, the liver had lesions of bile ducts and of adjacent small blood vessels in the hilum, very similar to those complicating hepatic artery thrombosis after liver transplantation. These findings suggest that Schönlein-Henoch purpura can be complicated by vasculitis of the peribiliary vessels resulting in ischemic necrosis of the bile ducts. Schönlein-Henoch purpura can be added to the list of causes of ischemic cholangiopathies.

Bile Ducts↗
PubMed1999

Stability and compatibility of teicoplanin in parenteral nutrition solutions used in pediatrics.

AIMS: To investigate teicoplanin added to pediatric parenteral nutrition solutions in terms of its stability, its compatibility with parenteral nutrition solution components, and its diffusion through an antibacterial filter material. METHODS: Three binary solutions with and without teicoplanin were studied. Different solution compositions and teicoplanin concentrations were used: A (98.3 +/- 8.2 mg/l), B (116.3 +/- 12.4 mg/l), and C (162.7 +/- 16.2 mg/l). Concentrations of teicoplanin and of solution components, osmolality, and pH of each solution were measured at H0, after 24 h at room temperature, after 24 h at +4 degrees C followed by 24 h at room temperature, and after 144 h at +4 degrees C followed by 24 h at room temperature (H168). Teicoplanin concentrations were also measured before and after passage of each solution through a 0.22 micro filter. RESULTS: Teicoplanin concentrations remained unchanged from H0 to H168 in solutions A (99.6 +/- 8.3 mg/l), B (116.9 +/- 12. 3 mg/l), and C (162.4+12.9 mg/l). During the H0-H168 interval, iron and methionine were the only components that showed significant decreases, which were similar in solutions without teicoplanin [iron, -6.1% (A), -6.8% (B), and -4.5% (C); methionine, -7.3% (A) and -8. 7% (B)] and in those with teicoplanin [iron, -6.2% (A), -7.1% (B), and -4.0% (C, nonsignificant); methionine, -10.5% (A) and -10.7% (B)], indicating that they were not dependent on the presence of teicoplanin. Teicoplanin levels after filtration were identical to prefiltration values in solutions A (86.4 +/- 5.0 vs 89.8 +/- 3.4 mg/l) and B (112.6 +/- 4.3 vs 115.3 +/- 9.0 mg/l) but were 10.0% lower in solution C (161.6 +/- 3.9 vs 145.4 +/- 4.0; P << 0.001). CONCLUSIONS: Teicoplanin can be added to pediatric parenteral nutrition solutions to treat central venous catheter-related infections due to teicoplanin-susceptible organisms since its concentrations and those of solution components remain stable over time.

Anti-Bacterial Agents↗
PubMed1999

[Allergy to cow's milk protein hydrolysates: apropos of 8 cases].

BACKGROUND: The use of extensively hydrolyzed protein formulas is the best alternative for children with cow's milk allergy, though cases of allergies to hydrolyzed proteins have been reported. The aim of this study was to clarify from our experience the diagnostic, evolutive and therapeutic aspects of allergies to extensively hydrolyzed protein formulas. PATIENTS AND METHODS: We report eight cases of allergy to extensively hydrolyzed protein formulas seen between 1985 and 1998. The diagnostic criteria for allergy were either the appearance of immediate anaphylactic reactions after the ingestion of protein hydrolysate or a positive challenge test with the protein hydrolysate. RESULTS: Four children developed immediate anaphylactic symptoms after ingesting protein hydrolysate, and four children demonstrated subacute or chronic gastrointestinal symptoms. All children who developed acute anaphylactic symptoms had positive skin tests and specific IgF, antibodies (RAST) to cow's milk and/or hydrolyzed proteins. Conversely, in the four children with chronic gastrointestinal symptoms, skin tests and specific IgE antibodies were negative in three cases, but intestinal histology was abnormal in all of them when they were fed with a protein hydrolysate; this became normal after excluding the hydrolysate (data available in only two cases). Three children tolerated another protein hydrolysate form (whey vs. casein), four children had a favourable outcome when fed with human milk, and an amino-acid-based formula was successfully used in the most recent case. Nonhydrolyzed cow's milk proteins were tolerated after the age of 18 months in six children. Other atopic symptoms were observed in six children. CONCLUSION: Allergy to cow's milk protein hydrolysate is rare. The diagnosis is usually easy in children who develop acute anaphylactic symptoms, though intestinal histology is generally necessary for the diagnosis of allergy with chronic gastrointestinal symptoms. Treatment is based on the use of either another protein hydrolysate form (whey vs. casein) or an amino-acid-based formula.

Age Factors↗