Covid-19 et adolescence : constats cliniques et réflexions psychopathologiques à propos de quelques incidences immédiates ou différées

Nous avons tous, enfants, adolescents, adultes subi cette pandémie qui a profondément bouleversé nos vies pendant de nombreux mois et dont les conséquences sur le long terme restent largement hypothétiques. Les mesures de confinement, les menaces pesant sur la santé des proches, les contraintes restreignant les ouvertures sociales n’ont laissé personne indifférent, mais ont particulièrement pu faire obstacle au travail de séparation des adolescents. La plupart ont su déployer leurs capacités d’adaptation, alors que pour d’autres cette situation d’exception a déclenché des réactions propres à mettre à l’épreuve, voire à inquiéter leur entourage. Certains se sont d’emblée montrés débordés par les manifestations directes ou indirectes de leur angoisse ou par leur intolérance aux consignes gouvernementales, d’autres n’ont révélé leurs difficultés qu’au moment de la réouverture des établissements scolaires, voire dans un lointain « après-coup » comme en témoignent quelques études réalisées à distance révélant une nette augmentation des idéations suicidaires. On ne s’étonnera pas des problèmes d’adaptation des plus fragiles, de ceux souffrant de troubles psychopathologiques, mais force est de constater une augmentation de la demande de soins psychiques. Les dispositifs propres à accueillir et traiter la souffrance des adolescents font état de leur perplexité face à l’accroissement des gestes auto-vulnérants, des refus scolaires anxieux, des troubles des conduites alimentaires ou des diverses formes d’addiction aux écrans… Chacun s’accorde cependant à reconnaitre le rôle crucial des parents et de l’impact de leurs propres souffrances sur celle de leurs enfants, fussent-ils jeunes adultes. Il importe naturellement que les soignants ne les oublient pas dans le soutien qu’ils cherchent à offrir à leurs jeunes patients.

Amniotic fluid peptides predict postnatal kidney survival in developmental kidney disease

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-β4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-β4 abundance was confirmed with ELISA. Knockout of thymosin-β4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin β4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable.

Should We Assess Pituitary Function in Children After a Mild Traumatic Brain Injury? A Prospective Study

Objective: The aim of this study was to evaluate the frequency of hypopituitarism following TBI in a cohort of children who had been hospitalized for mild TBI and to identify the predictive factors for this deficiency. Design: A prospective study was conducted on children between 2 and 16 years of age who had been hospitalized for mild TBI according to the Glasgow Coma Scale between September 2009 and June 2013. Clinical parameters, basal pituitary hormone assessment at 0, 6, and 12 months, as well as a dynamic testing (insulin tolerance test) 12 months after TBI were performed. Results: The study included 109 children, the median age was 8.5 years. Patients were examined 6 months (n = 99) and 12 months (n = 96) after TBI. Somatotropic deficiency (defined by a GH peak <20 mUI/l in two tests, an IGF-1 <-1SDS and a delta height <0SDS) were confirmed in 2 cases. One case of gonadotrophic deficiency occurred 1 year after TBI among 13 pubertal children. No cases of precocious puberty, 5 cases of low prolactin level, no cases of corticotropic insufficiency (cortisol peak <500 nmol/l) and no cases diabetes insipidus were recorded. Conclusion: Pituitary insufficiency was present 1year after mild TBI in about 7% of children. Based on our results, we suggest testing children after mild TBI in case of clinical abnormalities. i.e., for GH axis, IGF-1, which should be assessed in children with a delta height <0 SDS, 6 to 12 months after TBI, and a dynamic GH testing (preferentially by an ITT) should be performed in case of IGF-1 <-1SDS, with a GH threshold at 20 mUI/L. However, if a systematic pituitary assessment is not required for mild TBI, physicians should monitor children 1 year after mild TBI with particular attention to growth and weight gain.

A qualitative study on the educational needs of young people with chronic conditions transitioning from pediatric to adult care

OBJECTIVES

Although patient education is recommended to facilitate the transition from pediatric to adult care, a consensus has not been reached for a particular model. The specific skills needed for the transition to help in facilitating the life plans and health of young people are still poorly understood. This study explored the educational needs of young people with diverse chronic conditions during their transition from pediatric to adult care.

METHODS

Qualitative semi-structured interviews were conducted with 17 young people with chronic conditions. A thematic analysis was conducted to examine the data.

RESULTS

Five themes emerged from the data, identified through the following core topics: learning how to have a new role, learning how to adopt a new lifestyle, learning how to use a new health care service, maintaining a dual relationship with pediatric and adult care, and having experience sharing with peers.

CONCLUSION

A shift in perspective takes place when the transition is examined through the words of young people themselves. To them, moving from pediatric to adult care is not viewed as the heart of the process. It is instead a change among other changes. In order to encourage a transition in which the needs of young people are met, educational measures could focus on the acquisition of broad skills, while also being person-centered.

Isolated hypospadias: The impact of prenatal exposure to pesticides, as determined by meconium analysis

Although endocrine-disrupting chemicals (EDCs, including pesticides) are thought to increase the risk of hypospadias, no compounds have been formally identified in this context. Human studies may now be possible via the assessment of meconium as a marker of chronic prenatal exposure. The objective of the present study was to determine whether or not prenatal exposure to pesticides (as detected in meconium) constitutes a risk factor for isolated hypospadias. In a case-control study performed between 2011 and 2014 in northern France, male newborns with isolated hypospadias (n = 25) were matched at birth with controls (n = 58). Newborns with obvious genetic or hormonal anomalies, undescended testis, micropenis, a congenital syndrome or a family history of hypospadias were not included. Neonatal and parental data were collected. Foetal exposure was assessed by determining the meconium concentrations of the pesticides or metabolites (organophosphates, carbamates, phenylurea, and phenoxyherbicides) most commonly used in the region. Risk factors were assessed in a multivariate analysis. The pesticides most commonly detected in meconium were organophosphates (in up to 98.6% of samples, depending on the substance) and phenylurea (>85.5%). A multivariate analysis revealed an association between isolated hypospadias and the presence in meconium of the phenylurea herbicide isoproturon and of the phenoxyherbicide 2-methyl-4-chlorophenoxyacetic acid (odds ratio [95% confidence interval]: 5.94 [1.03-34.11] and 4.75 [1.20-18.76]) respectively). We conclude that prenatal exposure to these two herbicides (as assessed by meconium analysis) was correlated with the occurrence of isolated hypospadias. The results of our case-control study (i) suggest that prenatal exposure to pesticides interferes with the development of the male genitalia, and (ii) emphasize the importance of preventing pregnant women from being exposed to EDCs in general and pesticides in particular.

Urea, Creatinine and Phosphate Kinetic Modeling during Dialysis: Application to Pediatric Hemodialysis

The kinetics of urea, creatinine and phosphate removal during dialysis were investigated in pediatric patients using a two-pool model taking into account fluid shifts and mass transfer between the two compartments. It is found that even urea must be described by a two-pool model since it presents a post dialysis rebound due to equilibration between the two compartments. Phosphate plasma concentration drops very sharply during the first hour of dialysis and rises rapidly during the rebound period. This pattern cannot be accounted for by the classical two-pool model with constant generation rate and mass transfer coefficients, but corresponds to a large time-dependent phosphate influx from the intracellular compartment in which phosphate is generated by biochemical reactions or liberated from the bones. This influx was calculated for four patients representing 8 dialysis sessions and was found to reach a plateau after 90 minutes of dialysis, dropping rapidly during the rebound period.

Maternal Exposure to Domestic Hair Cosmetics and Occupational Endocrine Disruptors Is Associated with a Higher Risk of Hypospadias in the Offspring

Pregnant women are exposed to various chemical products at home and at work. Some of these products contain endocrine-disrupting chemicals (EDCs) such as cosmetics, pesticides, industrial chemicals, heavy metals, plastics or medications that could alter sexual differentiation and increase the risk of hypospadias. We evaluated maternal occupational and household exposures that could constitute risk factors for hypospadias. From 2011 to 2014, we enrolled 57 full-term newborns with hypospadias and three randomly selected controls per case (162 control newborns), matched for gestational age, from 11 maternity units in Picardy, France. Neonatal and parental data were collected at birth (personal characteristics, maternal lifestyle, and medical history). Maternal occupational exposure was assessed by a job-exposure matrix for EDCs from a job history questionnaire completed by mothers. Odds ratios (OR) and 95% confidence intervals (CI) were calculated with univariate and multivariable logistic regression, and adjusted for relevant covariates. Multivariate analysis showed a strong association between hypospadias and potential maternal occupational exposure to EDCs and maternal household use of hair cosmetics (OR 6.1, 95% CI: 1.1–34.9; OR: 9.6, 95% CI: 1.4–66.1, respectively). Our results suggest that maternal occupational exposure to EDCs is a risk factor for hypospadias and suggests a possible influence of household use of hair cosmetics during early pregnancy on the incidence of hypospadias in the offspring. A larger study with more accurate exposure assessment should evaluate the impact of EDCs in hair cosmetics on the incidence of hypospadias.

[Chronic intestinal pseudo-obstruction complicated by an eating disorder]

Chronic idiopathic intestinal pseudo-obstruction is a rare and serious chronic disease starting in childhood, which can affect the entire digestive tract. It is caused by a peristalsis intestinal disorder that leads to occlusions without any obvious obstruction. Few studies have been carried out regarding the prognosis of this illness. This disease is often diagnosed by a process of elimination, but some histological anomalies have been present in the digestive wall of certain patients. This clinical case concerns a 17-year-old girl affected by CIPO and eating disorders. It seems difficult to discriminate between digestive disorders and eating disorders. What psychological effects can this severe pathology have? Are eating disorders induced by CIPO? These questions are raised in this article through the example of this patient's somatopsychic complexity and the ensuing difficulties in her overall care.

[Renal late effects in patients treated for cancer in childhood]

Impaired renal function may occur following multimodal treatment of cancer in childhood. Renal late effects caused by chemotherapy, renal surgery and/or radiotherapy are now well described; but little is known about their prevalence and time of development. Herein, we provide a synthesis of the different renal complications that may occur with their physiopathology in relation with specific treatment exposures. This review summarized the literature that supported the recommendations issued by the long-term follow-up group of the "Société française des cancers de l'enfant (SFCE)" for childhood cancer survivors at risk for nephrotoxicity (www.sfce.org ; www.soc-nephrologie.org/SNP/index.htm). We developed these monitoring elements and the lifestyle recommendations for all asymptomatic survivors.

Coping strategies associated with suicidal behaviour in adolescent inpatients with borderline personality disorder

OBJECTIVES

To compare the coping strategies of adolescents with borderline personality disorder (BPD) to the coping strategies of adolescents without BPD, and to explore the association of coping with suicidal ideation and attempts among adolescents with BPD.

METHOD

Adolescent inpatients (n = 167) aged 13 to 17 years were admitted after suicide attempts and evaluated within 10 days, using the abbreviated version of the Diagnostic Interview for Borderlines-Revised, the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version supported by a team consensus best estimate method for the primary diagnosis, the Adolescent Coping Scale, and the Columbia-Suicide Severity Rating Scale.

RESULTS

Firstly, compared with adolescents without BPD, adolescents with BPD relied more on nonproductive coping strategies, mostly avoidant strategies, and less on productive coping strategies. Secondly, coping appeared as a factor associated with suicidal ideation in adolescents with BPD. While while controlling for age, sex, and depression, multivariate analyses showed a significant positive association between the coping strategy to focusing on solving the problem and suicidal ideation.

CONCLUSION

The use of avoidant strategies by adolescents with BPD could be viewed as attempts to increase emotional regulation. Problem-solving strategies in the immediate aftermath of a suicide attempt may prevent adolescents with BPD from overcoming a crisis and may increase suicidal ideation.

Another case of idiopathic megaesophagus in a girl with growth hormone deficiency

BACKGROUND

Achalasia or idiopathic megaesophagus is rare in children, and an association with growth hormone (GH) deficiency has rarely been described.

CASE REPORT

This report is of a girl treated with recombinant GH (rGH) for isolated GH deficiency who simultaneously presented with idiopathic megaesophagus.

CONCLUSION

This case report highlights the fact that practitioners need to be aware of this possible morbid association.

[Cystinuria in children: A report of 4 cases]

Cystinuria is an inherited autosomal-recessive disorder of renal reabsorption of the dibasic amino acids. It is the cause of about 6% of all kidney stones observed in children. Cystine is relatively insoluble at the physiological pH of urine. Cystine stones are characteristic and frequent recurrences are observed. We report on 4 cases and describe the initial presentation (obstructive renal failure, urinary sepsis, familial screening) and the medical and surgical management. Medical management is mainly based on hyperhydration and urine alkalinization. Long-term therapy with sulfhydryl agents to prevent formation of renal stones seems to be effective but adverse side effects are frequent, requiring the withdrawal of treatment. Urological management has evolved from surgical stone removal to minimally invasive procedures (extracorporeal shock wave lithotripsy, ureteroscopy).

Effect of hydrochlorothiazide on urinary calcium excretion in dent disease: an uncontrolled trial

BACKGROUND

Thiazide doses equivalent to 1 to 2 mg/kg/d of hydrochlorothiazide (HCTZ) have been proposed to correct hypercalciuria and prevent kidney failure in patients with Dent disease. However, they can cause adverse metabolic effects in the long term. In treating hypertension in children, lower thiazide doses have been shown to be as effective and well tolerated.

STUDY DESIGN

Uncontrolled trial, with forced-titration sequential open-label study design.

SETTING & PARTICIPANTS

7 boys with genetically confirmed Dent disease and mild phenotype (neither overt sodium wasting nor kidney failure).

INTERVENTION

After a 1-month run-in period, patients sequentially received amiloride (5 mg/d) alone (1 month) and then for 3 periods of 2 months in association with increasing doses of HCTZ (<0.2, 0.2 to 0.4, and 0.4 to 0.8 mg/kg/d).

OUTCOMES

Urinary calcium excretion and extracellular volume indicators.

MEASUREMENTS

At the end of each period, 2 daily 24-hour urinary collections were performed on the days preceding admission. Blood and spot urine samples also were collected.

RESULTS

A greater HCTZ dose increased renin, aldosterone, and plasma protein concentrations. Amiloride alone had no effect on calcium excretion. The greatest HCTZ doses decreased spot urinary calcium excretion by 42% compared with baseline (median, 0.3; minimum, maximum, 0.2, 0.8 versus median, 0.8; minimum, maximum, 0.4, 1.1, respectively; P = 0.03). However, patients developed adverse reactions, including muscle cramps (n = 2), biological (n = 7) or symptomatic hypovolemia (n = 1), hypokalemia (n = 4), and hyponatremia (n = 1), which all corrected after treatment withdrawal.

LIMITATION

Small sample size and absence of a control group.

CONCLUSION

HCTZ doses greater than 0.4 mg/kg/d decreased calcium excretion, but were associated with significant adverse events. Thiazide diuretic therapy should be considered with caution in children with Dent disease.

Differential impact of complement mutations on clinical characteristics in atypical hemolytic uremic syndrome

Mutations in factor H (CFH), factor I (IF), and membrane cofactor protein (MCP) genes have been described as risk factors for atypical hemolytic uremic syndrome (aHUS). This study analyzed the impact of complement mutations on the outcome of 46 children with aHUS. A total of 52% of patients had mutations in one or two of known susceptibility factors (22, 13, and 15% of patients with CFH, IF, or MCP mutations, respectively; 2% with CFH+IF mutations). Age <3 mo at onset seems to be characteristic of CFH and IF mutation-associated aHUS. The most severe prognosis was in the CFH mutation group, 60% of whom reached ESRD or died within <1 yr. Only 30% of CFH mutations were localized in SCR20. MCP mutation-associated HUS has a relapsing course, but none of the children reached ESRD at 1 yr. Half of patients with IF mutation had a rapid evolution to ESRD, and half recovered. Plasmatherapy seemed to have a beneficial effect in one third of patients from all groups except for the MCP mutation group. Only eight (33%) of 24 kidney transplantations that were performed in 15 patients were successful. Graft failures were due to early graft thrombosis (50%) or HUS recurrence. In conclusion, outcome of HUS in patients with CFH mutation is catastrophic, and posttransplantation outcome is poor in all groups except for the MCP mutation group. New therapies are urgently needed, and further research should elucidate the unexplained HUS group.

Darbepoetin, effective treatment of anaemia in paediatric patients with chronic renal failure

Darbepoetin alpha (DA) is a unique long-acting treatment for anaemia in patients with chronic renal failure (CRF). This study assessed the mean dose of DA to achieve and maintain haemoglobin (Hb) levels between 11 g/dl and 13 g/dl in CRF children aged 11 years to 18 years. This observational, prospective study was conducted in 39 patients treated with DA. Twenty-nine patients were switched from recombinant human erythropoietin (r-HuEPO), and ten patients were naive to r-HuEPO. Naive patients received initial doses of 0.45 microg/kg of DA. Switched patients received a dose adjusted to the prior dose of r-HuEPO (200 IU r-HuEPO:1 microg DA). Among the switched patients, 79.3% received dialysis. No naive patients underwent dialysis. Overall, 74% of patients showed increased Hb level, with a mean value of 11.6 +/- 1.6 g/dl, using a mean DA dose of 0.63 +/- 0.48 microg/kg per week, and 66.7% patients reached the target Hb level. Hb increased in naive patients from 9.5 (95% CI: 7.7, 11.4) to 11.7 (95% CI: 10.9, 12.6) g/dl and in switched patients from 11.1 (95% CI: 10.6, 11.5) to 11.5 (95% CI: 10.8, 12.2) g/dl). Higher doses of DA were needed in the "switched" than in the "naive" patients to maintain Hb levels over 11 g/dl, respectively 0.73 (95% CI: 0.54, 0.92) and 0.34 (95% CI: 0.16, 0.52) microg/kg per week. Our results indicate the doses of DA necessary to treat CRF patients aged 11 years to 18 years. DA was an effective treatment to stabilise CRF patients at extended dosing intervals.

Obésité au temps de l'adolescence : repères pour une prise en charge

The increasing prevalence of adolescent obesity justifies widespread effort and attention of the paediatrician. In order to manage, following points are to be documented: (I) weight status assessed on the basis of body mass index (BMI)split in two levels: obesity grade I: >or=97 ème centile, obesity grade 2: level IOTFC 30; (2) complete anamnesis including age at adiposity rebound and existence of overweight in family; (3) research of associated morbidity and medical risks;(4) assessment of food intake and feeding practice; (5) assessment of physical activity; (6) talk with the adolescent to assess the psychological status, looking after depressive symptoms, anxiety, loss of self esteem. Once the items are documented, it allowed making a plan to manage the obesity in alliance with the adolescent and his family.

Prévalence des marqueurs biologiques de la maladie cœliaque dans une cohorte d’enfants et d’adolescents diabétiques de type I

The aim of this study was to determine the prevalence of celiac disease (CD) markers in a French cohort of 84 children type 1 diabetics. Detection of antitransglutaminase (AtTG), antiendomysium (AEA) and antigliadin (AGA) antibodies was performed. Group 1 included 81 (96.4%) diabetic patients with negative antibodies. Group 2 included 3 patients (3.6%) with positive serological markers: 1 AGA-AEA-AtTG and 1 AEA-AtTG with proved histological diagnosis and 1 AGA positive with negative histology. No statistically significant difference was observed between the groups with regard to age, duration of diabetes, familial target stature, and ratios Height/Age and Weight/Height. Presence of CD serological markers was related to a lower level of HbA1c. Prevalence of CD serological markers is important in this French cohort but lower than other countries.

[Central venous access for hemodialysis: use and practice with the child in France]

Central venous catheter (CVC) are being increasingly used as hemodialysis vascular access. In order to evaluate the indications, practice and uses in the pediatric population, we conducted a study in children with renal failure (RF). A questionnaire was sent to the 21 french paediatric hemodialysis centers to inquire population deserved, number, type, site and indications of CVC, procedure of management and attitude towards infection and thrombosis. A prospective survey was added to compile information about CVC during the period 7/2000-31/12/2000. Results (exhaustivity response 80%) showed 1. large diversity in choice of material with predominance of pediatric permcath QUINTON; 2. exclusive surgical insertion for 8 out of 19 centers; 3. rare use of femoral route (never and exceptionally reported, respectively by 4 and 6 centers and predominantly in acute RF; 4. heterogene attitude towards fixing, dressing, heparine locking and procedure of urokinase administration in case of thrombosis, whilst procedure towards infection was homogeneous; 5. indications of insertion of the 31 prospective study CVC were distributed in 4 subgroups a) breakdown of vascular permanent access (6 cases) or of peritoneal dialysis (2 cases), b) unexpected terminal renal failure (6 cases), c) deliberate choice to wait transplantation (4 cases) or to face breakdown of transplantation (4 cases), d) dysfunction of a previous CVC (7 cases); 6. a rate of 20% of dysfunction (flow problem); 7. a rate of replacement of 11%. AVC are effective forms of vascular access. However CVC indications should be carefully analysed and balanced if possible with alternative route such as anticipated creation of arterioveinous fistula, peritoneal dialysis and preemptive transplantation.

[Comparison between scintigraphy, B-mode, and power Doppler sonography in acute pyelonephritis in children]

PURPOSE

Comparing Power Doppler imaging versus technetium-dimercapto-succinic-acid (Tc-DMSA) scintigraphy in acute pyelonephritis of childhood.

PATIENTS AND METHODS

INCLUSION CRITERIA

First episode of urinary tract infection, clinical and biological findings suggesting an upper lesion, absence of urological malformation or obstruction, absence of reflux (or vesico-ureteral reflux inferior to grade 3). Number of patients: 49, length of the study: 26 months (from November 95 to January 98).

METHODS

Tc99m-DMSA scintigraphy (after five days), B mode and Power Doppler imaging (on the day of admission or the following day). Systematic cystography (day 5 to day 30).

RESULTS

In terms of positive diagnosis, scintigraphy was superior to Power Doppler, and the latter was superior to B mode ultrasonography. Sensitivity (scintigraphy being the gold standard) was equal for both B mode and Power DopplerUS imaging, but combined Power Doppler and B mode US provided improved results.

CONCLUSION

Currently, the results with Power Doppler imaging are insufficient to replace DMSA scintigraphy. However, Power Doppler is a good complement to B mode US.

[Prevention of vitamin D deficiency in adolescents and pre-adolescents. An interventional multicenter study on the biological effect of repeated doses of 100,000 IU of vitamin D3]

Recent studies have shown a high prevalence of calcium and vitamin D deficiencies in adolescents. The aim of this present study was to follow the changes in calcium status and 25 hydroxyvitamin D (25[OH]D) and parathyroid hormone (iPTH) levels during winter in preadolescents and adolescents from four university hospitals in northern France.

SUBJECTS AND METHODS

Two groups of teenagers and adolescents (range: 10-15 years) were followed from October 1996 to June 1997. They were given either 100,000 IU of vitamin D (treated group n = 33) or a placebo (control group n = 35) in October, January and April. Serum calcium, phosphate, 25(OH)D and iPTH levels were measured at inclusion and every three months thereafter.

RESULTS

At inclusion, plasma or serum 25(OH)D levels were < or = 10 ng/mL in 16 subjects and < 6 ng/mL in six. In control children, no significant change in 25(OH)D occurred during the study, while plasma or serum iPTH levels increased to 34 +/- 11 pg/mL. In the treated groups, 25(OH)D levels remained > 20 ng/mL in every subject; no hypercalcemia was observed; and the mean plasma or serum iPTH level was 25 +/- 14 pg/mL at the end of the study.

CONCLUSION

Teenagers presented with a high prevalence of biological vitamin D deficiency at the end of summer. The increase of iPTH during winter in the unsupplemented group suggests that this has secondary consequences on their calcium homeostasis unless they are supplemented with vitamin D. We advocate a sufficient calcium supply and a 100,000 IU vitamin D supplement given two or three times during winter to preadolescents and adolescents living in northern France.

[Use of the admission service and pediatric emergency service of a university hospital center by adolescents (12-19 years): utilization and messages]

A retrospective survey concerning all patients ages 12-19 who had registered themselves at the admitting service of the paediatric emergency unit in the university hospital centre of Amiens was carried out in 1995. 2812 adolescents were received (18% of total admissions). The male/female sex-ratio was 1 to 3. The average age was 13.2 years old. Hospitalisations were more frequent in the spring and were predominantly on Mondays (17%). More than 2/3 of the adolescents were accompanied by their parents and 20% were referred by their doctors or by the SAMU (mobile emergency medical service). Two percent arrive alone. Traumatic pathology is the main reason for admission (1960 patients). Organic pathologies represent 24% of admissions and are essentially digestive pathologies (40%). "Suffering" adolescents (defined as those requiring an intervention with a psychotherapist as a matter of priority) only represent 6% of visits to the emergency unit, of which 2/3 correspond to suicide attempts. 24% of adolescents are hospitalised at the university hospital centre of Amiens within the paediatric services or specialised services (ENT, stomatology, etc.).

[Cardiac involvement during classic hemolytic uremic syndrome]

BACKGROUND

Cardiac involvement rarely occurs in classic hemolytic uremic syndrome (HUS); it is often fatal.

CASE REPORTS

The first patient, a 21-month-old boy, developed classic HUS with acute renal failure. Peritoneal dialysis was performed for 20 days. On the 10th day of dialysis, myocardial infarction occurred, probably related to coronary thrombus. The patient was given heparin and antibiotics because of an unexplained fever. The outcome was favorable despite antero-apical cardiac necrosis, and moderated chronic renal failure. The second patient, a 24-month-old girl, also showed a classic HUS, which required peritoneal dialysis for 10 days. Dilated cardiomyopathy with cardiac failure appeared on the 4th day of dialysis, not related to the volume overload and metabolic consequences of the acute renal failure, such as systemic hypertension or ineffective dialysis. On the 5th day of dialysis neurological involvement appeared. Neurological, cardiac and renal outcome was favorable. The third patient, a 25-month-old girl, developed a classical HUS, requiring peritoneal dialysis for 25 days. No cardiac insult appeared during the acute phase of the disease. After dialysis, the child had chronic renal failure (creatinine clearance: 15 mL/min/1.73 m2). Dilated cardiomyopathy appeared 3 months later, without definite etiology. The outcome was favorable with digoxin treatment.

CONCLUSION

A cardiac involvement should also be searched for in the acute phase of HUS and several months later.

Renal osteodystrophy in dialysis patients: diagnosis and treatment

This article reviews the clinical, biological, radiological, and pathological procedures and their respective indications for the practical diagnosis of the following various histological patterns of renal osteodystrophy: osteitis fibrosa due to parathyroid hormone (PTH) hypersecretion: osteomalacia or rickets due to native vitamin D deficiency and/or aluminum overload; and adynamic bone disease (ABD) due to aluminum overload and/or PTH secretion oversuppression. Our advice regarding bone biopsy is to restrict it to patients with symptoms and hypercalcemia, especially those who have been previously exposed to aluminum. In other cases, we propose relying merely on the determination of the plasma concentrations of calcium, protide, phosphate, bicarbonate, intact PTH, aluminum, 25(OH)D3, and alkaline phosphatase (total and bony if hepatic disease is associated) to choose the appropriate treatment. Because of the danger of the desferrioxamine treatment necessary to chelate and remove aluminum, the suspicion of aluminic bone disease (osteomalacia or ABD) will always be confirmed by a bone biopsy. In the case of nonaluminic osteomalacia, correction of the vitamin D deficiency by native vitamin D or 25(OH)D3, and of the calcium deficiency and acidosis by alkaline salts of calcium and if necessary sodium bicarbonate are sufficient to cure the disease. In the case of nonaluminic ABD, the stimulation of PTH secretion by the discontinuation of 1alpha hydroxylated vitamin D and the induction of a negative calcium balance during dialysis by decreasing the calcium concentration in the dialysate will allow an increase of the CaCO3 dose to correct for hyperphosphatemia without inducing hypercalcemia. For hyperparathyroidism, i.e., plasma intact PTH levels greater than two- or four-fold the upper limit of normal levels (according to the absence or presence of previous aluminum exposure), the treatment will consist in increasing the CaCO3 dose to correct for hyperphosphatemia together with a decrease of the calcium concentration in the dialysate if the dose of CaCO3 is so high that it induces hypercalcemia. When the hyperphosphatemia has been corrected and there is still a low or normal corrected plasma calcium level, 1alpha(OH)D3 in an oral bolus 2 or 3 times a week should be given at the minimal dose of 1 microg. When the PTH level stays above 400 pg while hypercalcemia occurs and hyperphosphatemia persists, surgical subtotal parathyroidectomy is recommended or the injection of calcitriol into the big nodular hyperplastic parathyroid glands under sonography control in high surgical risk patients. Special recommendations are given for children.

Extra- and intracellular volume monitoring by impedance during haemodialysis using Cole-Cole extrapolation

A method is presented for monitoring the relative variation of extracellular and intracellular fluid volumes using a multifrequency impedance meter and the Cole-Cole extrapolation technique. It is found that this extrapolation is necessary to obtain reliable data for the resistance of the intracellular fluid. The extracellular and intracellular resistances can be approached using frequencies of, respectively, 5 kHz and 1000 kHz, but the use of 100 kHz leads to unacceptable errors. In the conventional treatment the overall relative variation of intracellular resistance is found to be relatively small.

Continuous measurements by impedance of haematocrit and plasma volume variations during dialysis

A technique for continuous measurements of haematocrit and plasma volume in the arterial line of dialysed patients has been tested in vitro and in vivo. This method uses impedance measurements at 5 kHz and requires a single haematocrit measurement. It relies on two assumptions: that plasma resistivity does not change during dialysis and that blood resistivity obeys Hanai's model. Both assumptions are verified during in vitro tests. Haematocrits measured in vivo by this method are found to be in good agreement with direct measurements from blood samples. The haematocrit variation is then used to monitor changes in plasma volume, assuming conservation of erythrocyte volume. In addition, it is possible to obtain the variation in interstitial volume by combining these data with body impedance measurements.

Phosphate end dialysis value: a misleading parameter of hemodialysis efficiency. French Society for Pediatric Nephrology

Despite low end dialysis serum phosphate levels (Pe) the control of phosphate retention remains often unsatisfactory in dialyzed patients. In order to assess the value of Pe in dialyzed children as an indicator of dialytic phosphate removal, we studied serum phosphate kinetics over the period of dialysis and post dialysis and compared these with urea kinetics. A multicenter study was conducted in the 21 French pediatric hemodialysis units and included 144 children under 15 years of age. Blood urea and phosphate concentrations were measured at the beginning, at 45 min later, at the end of dialysis, and 30 min post dialysis. At 60 min and at 360 min post dialysis measurements were made only for a subgroup of 12 children. From the serum levels, reduction ratios for urea (URR) and phosphate (PRR) and post dialysis rebound for urea (PDUR) and phosphate (PDPR) were calculated. URR (over the dialysis session, 72% +/- 9%) was higher than PRR (47% +/- 12%). Moreover, urea removal continued throughout the dialysis period, while most of the reduction in phosphate occurred in the initial dialysis period. Post dialysis urea rebound was limited to the 60th min post dialysis, whereas post dialysis phosphate rebound occurred until the 360th min post dialysis; by this time the serum phosphate levels had almost reached the predialysis levels. In summary, serum phosphate kinetics over dialysis and post dialysis periods in children appear to be misleading for the quantification of phosphate removal, i.e., phosphate clearance is a poor indicator of dialytic phosphate removal.

Possible person-to-person transmission of Escherichia coli O111--associated hemolytic uremic syndrome

Over a 3-month period, ten children (aged 1-13 years) from a 15-km radius in southern Picardy developed typical D+ hemolytic uremic syndrome (HUS). Polymerase chain reaction, using two pairs of verocytotoxin 1-(VT1) and VT2-specific oligonucleotide primers and an internal control was used to detect VT genes directly from stools samples. VT2 gene was detected in seven of nine patients' stools and in 5 of 14 contacts' stool samples. A VT2-producing Escherichia coli (VTEC) O111 was isolated from five of nine children's stools and in 3 adults' stools of the 14 tested. A retrospective case-control study was performed which showed a higher rate of absence in school A, where the first four cases were detected, compared with a control school. The odds ratio for the whole school was 2.77 (confidence interval 1.46-5.26), and 15 (confidence interval 2.54-115.6) if only the nursery classes were considered. A culture of all food samples from households was always negative for VTEC. A retrospective cohort study performed in 89% of children attending school A showed no linkage between food or drink and gastroenteritis. These findings emphasize the potential for person-to-person transmission of VT2-producing E. coli O111, since the only salient risk factor was close contact.