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Biomedical subjects

C Le Bihan

Publications and source records attributed to C Le Bihan.

At least 19 recordsLinked to original sources

Early prognostic factors for intellectual outcome in CHARGE syndrome.

CHARGE syndrome (coloboma, heart disease, atresia of the choanae, retarded growth and mental development, genital anomalies, and ear malformations and hearing loss) is a heterogeneous condition for which early prediction of intellectual outcome is important but difficult. The psychomotor milestones and intellectual outcome of a consecutive series of children with CHARGE syndrome who were observed by the same team from the neonatal period to the time of study were analyzed retrospectively. Twenty-one children (11 males and 10 females, aged from 5 to 12 years, mean 8 years 7 months, SD 2 years 5 months) were included. The influence of 19 early identifiable parameters that could be considered as deleterious for intellectual outcome was recorded. Generally, the main psychomotor milestones (0 to 4 years) were severely delayed, although intellectual outcome (at primary-school age) was satisfactory for half the children in this series. We show that extensive bilateral coloboma resulting in low vision, microcephaly, and brain malformation were the only three parameters that were predictive of poor intellectual outcome. Conversely, severe neonatal medical conditions, such as tracheotomy, conditions requiring long stays in hospital, or cardiac surgery were not predictive of poor intellectual outcome. Severe hearing loss was not found to be negatively correlated with intellectual outcome once coloboma had been taken into account.

Abnormalities, Multiple↗

Distinct effects of diazepam and NK1 receptor antagonists in two conflict procedures in rats.

Convergent data suggest that SP, through the activation of neurokinin1 receptors (NK1-R), may be involved in anxiety. In particular, NK1-R antagonists have been reported to exert anxiolytic-like effects in a variety of animal procedures in which anxiety-related behaviour is induced by novelty. The present study investigated the effects of acute blockade of NK1-R in conflict paradigms, another category of anxiety-related procedures, in which positively reinforced responses are suppressed by contingent punishment. For this purpose, three selective antagonists with nanomolar affinity for rat NK1-R, GR205171, RP67580 and [2-cyclopropoxy-5-(5-(trifluoromethyl)tetrazol-1-yl)benzyl]-(2-phenylpiperidin-3-yl)amine (Compound L), were tested in the safety signal withdrawal operant paradigm. In this procedure, suppression of lever pressing for food was induced by the withdrawal of a conditioned signal for safety, with no presentation of a conditioned signal for punishment, and no punishment. Compound L was also tested in the punished drinking test, which consists of the contingent delivery of electric footshocks upon water drinking. As expected, the reference compound, diazepam (2 mg/kg s.c.), induced an anxiolytic-like effect, as indicated by significant increases of the number of responses emitted during conflict period in the operant procedure, and footshocks received in the drinking test. In contrast, GR205171 (10 mg/kg s.c.), RP67580 (0.25-8 mg/kg s.c.) and Compound L (10 and 30 mg/kg s.c.) failed to release lever pressing during the operant conflict period. In addition, punished drinking was not affected by Compound L (3-30 mg/kg s.c.). These data show that NK1-R blockade has no anxiolytic-like effects in conflict paradigms, thereby suggesting that the anxiolytic properties of NK1-R antagonists are less broad than those reported for benzodiazepines.

Animals↗

Insulin-like growth factor I correlates with lean body mass in cystic fibrosis patients.

BACKGROUND: A major consequence of malnutrition in cystic fibrosis (CF) patients is the loss of lean body mass (LBM) and the subsequent impairment of respiratory muscle function. AIM: To determine whether insulin-like growth factor I (IGF-I) could be related to the LBM depletion and the evolution of respiratory disease in CF patients. METHODS: LBM was evaluated by dual energy x ray absorptiometry; serum concentrations of IGF-I were measured in 24 CF patients twice with a one year interval. Both values were expressed as SD score (SDS) calculated from normal data for age, sex, and pubertal stage and analysed with respect to anthropometric evaluation and disease related conditions. RESULTS: At the initial evaluation, IGF-I SDS had a mean value of -0.98 (range -3.6 to 3.2) and correlated with weight for age index, LBM SDS, and lung disease related conditions. Multiple regression analysis showed that only LBM remained independently related to IGF-I, suggesting that the relation of IGF-I to LBM was independent of weight and that the correlation between IGF-I and the respiratory conditions was related to the level of LBM. IGF-I SDS at the first evaluation was lower for the patients who lost > or =5% of weight for age index or > or =1 SD of LBM between the two evaluations. CONCLUSION: Low levels of IGF-I could be crucial for clinical outcome by impairing LBM and respiratory function. IGF-I could be a tool for nutritional evaluation by identifying the CF patients at risk of LBM depletion.

Absorptiometry, Photon↗

Refractory coeliac sprue is a diffuse gastrointestinal disease.

BACKGROUND: Refractory coeliac sprue (RCS) with an immunophenotypically aberrant clonal intraepithelial lymphocyte (IEL) population is considered a cryptic form of intestinal T cell lymphoma. AIMS: To investigate the distribution of the abnormal and monoclonal IEL population in the digestive tract of RCS patients. PATIENTS AND METHODS: We compared the frequency of lymphocytic gastritis (LG) and lymphocytic colitis (LC), together with IEL phenotype and T cell clonality, in gastric and colonic samples from 15 adults with RCS (all with aberrant CD3 intracytoplasmic(+) surface(-) CD8(-) clonal IELs on duodenojejunal biopsies), 18 patients with active coeliac disease (ACD), and 10 patients with coeliac disease (CD) on a gluten free diet (GFD-CD) by means of immunohistochemistry and multiplex polymerase chain reaction amplification of the T cell receptor gamma gene (TCR-gamma) rearrangement. Blood samples of nine RCS patients were also tested for clonality. RESULTS: LG was found in 9/14 (64%), 11/18 (61%), and 3/10 (30%) patients with RCS, ACD, and GFD-CD, respectively, while LC was found in 6/11 (55%), 3/4 (75%), and 2/3 (66%) patients. Contrary to CD, all samples from patients with LG and LC showed an aberrant IEL phenotype. Monoclonal TCR-gamma rearrangements were detected in 8/13 (62%), 8/10 (80%), and 4/9 (44%) of gastric, colonic, and blood samples, respectively, from RCS patients, while in CD patients such rearrangements were only found in 2/25 (8%) gastric samples. CONCLUSION: The immunophenotypically aberrant monoclonal IEL population present in the small intestine of patients with RCS frequently disseminates to the blood and the entire gastrointestinal epithelium, suggesting that this is a diffuse gastrointestinal disease.

Adult↗

Typical essential thrombocythaemia does not express bcr-abelson fusion transcript.

Essential thrombocythaemia (ET) is a chronic myeloproliferative disorder (MPD) characterized by an elevated platelet count and no identifiable underlying primary cause. According to the diagnostic criteria of the Polycythemia Vera Study Group (PVSG), ET lacks features diagnostic for other MPDs, including the Philadelphia chromosome (Ph) or bcr-abl rearrangement. Recently, some authors have reported bcr-abl transcript positivity in ET patients, but these findings remain controversial. The aim of this study was to investigate whether the bcr-abl transcript could be found in ET patients and to verify the hypothesis of a new ET variant. ET patients (n = 121) with a median age at diagnosis of 55 years were enrolled. The bcr-abl transcript status was examined by multiplex reverse transcription-polymerase chain reaction. Only two cases were positive for bcr-abl, one of which had the Ph at diagnosis. The positive bcr-abl transcript was associated, in both cases, with mild basophilia at diagnosis. After a median follow-up of 43 months (0-309 months), two patients in the bcr-abl-negative group developed Ph and bcr-abl-negative acute myeloid leukaemia (AML). In contrast, one of the two patients in the bcr-abl-positive group died from AML 13 years after diagnosis. In conclusion, our data on a large group of patients shows the rarity of the bcr-abl transcript in well-established ET. However, a subset of patients with apparent ET and basophilia may express the transcript and may constitute a novel entity intermediate between chronic myeloid leukaemia (CML) and typical ET. A prospective study is warranted in order to define better the clinical and biological characteristics of bcr-abl-expressing ET.

Adolescent↗

Assessment of right ventricular lipomatosis by histomorphometry in control adult autopsy cases.

A histomorphometry study was carried out to assess the degree of right ventricular lipomatosis in control autopsy cases and to evaluate if this was correlated with parameters such as sex, age, body mass index (BMI) and heart weight. A total of 70 adult cases were selected from cases of violent death between 1991 and 1999 and where autopsies were carried out in the Department of Pathology and Forensic Medicine in Garches. All cases with heart pathology, abnormal BMI or putrefaction were excluded. Cases with lung or liver pathology were also excluded. Furthermore, 10 adult autopsy cases who died suddenly of arrhythmogenic right ventricular cardiomyopathy (ARVC) were compared with 10 age and sex-matched control cases. Details on sex, age, BMI and heart weight were obtained from the post-mortem records. For each case one sample of the right front ventricular wall was fixed in 10% neutral saline-buffered formalin and one 5-microm-section was stained with haematoxylin and eosin. The Leica Quantimet 500 analysis system was used for the histomorphometrical study. The mean degree of lipomatosis was measured under blind conditions in the ventricular wall and epicardial fat was excluded. Covariance analysis and the Wilcoxon test were used for statistics. The mean age of the control population was 37.5 years, the sex ratio was 1.9:1 (male:female). The mean degree of lipomatosis was 17.03% and the degree of lipomatosis was significantly correlated with age (p = 0.0029) but not with sex, BMI and heart weight. There was a statistically significant increase in fat in ARVC cases compared with age and sex-matched controls (p < 0.001). Fat infiltration of the right ventricle could be an adipose involution due to an ageing process and heavy fat infiltration can be difficult to distinguish from ARVC. Our study suggests that fat infiltration is not essential for the post-mortem diagnosis of ARVC which also requires fibrosis and degenerating myocytes trapped within areas of fibrosis.

Adolescent↗

Extracellular serotonin is enhanced in the striatum, but not in the dorsal hippocampus or prefrontal cortex, in rats subjected to an operant conflict procedure.

In rats trained in an operant fixed-interval-30-s schedule of food reward (FI-30s), acute exposure to contingent footshock resulted in a response suppression that was released by diazepam (DZP; 4 mg/kg ip) but not by buspirone (0.25 or 0.50 mg/kg ip). Compared with baseline, hippocampal and cortical extracellular levels of serotonin (5-HText) did not change, regardless of operant period (punished or nonpunished) and drug. In contrast, in the striatum, an increase of 5-HText levels (535%) occurred during the punished period, counteracted by DZP. This effect was observed only in rats that were low responders during both nonpunished and punished periods, that is, those that exerted an efficacious control over responding. Uncontrollable shocks or exposure to an unfamiliar open field did not modify striatal 5-HText. Together, these results suggest that an acute activation of 5-HT neurons afferent to the striatum allows the rats to efficiently block responses that are negatively reinforced.

Animals↗

A common promoter variant of the leptin gene is associated with changes in the relationship between serum leptin and fat mass in obese girls.

Mutations in the leptin gene lead to rare obese syndromes of Mendelian inheritance in humans and rodents. However, no relevant mutations are found in the coding region of leptin gene DNA in patients with common multifactorial obesity. These obese patients tend to have an elevation of serum leptin proportional to their adiposity but with a rather wide dispersion of leptin levels for a given body fat content, which in part is attributable to sexual dimorphism. The current study, performed in two independent Caucasian cohorts of obese girls, shows that a frequent promoter variant of the leptin gene is associated with changes in the relationship between serum leptin and body fatness. Girls of comparable adiposity have different circulating leptin levels, depending on their genotype at this locus. Girls with the -/- Lep -2,549 genotype have 25% lower mean leptin levels than the girls with other genotypes, as reflected by differences in the regression slopes of leptin-to-fat mass. Therefore, genetic factors related to the leptin gene may be important in defining the set point of obese individuals (i.e., the circulating leptin level for a given degree of body fatness). This definition may be of both physiological and therapeutic relevance, although a phenotypic association with an individual single-nucleotide polymorphism is not sufficient to assign function to this particular nucleotide site.

Adipose Tissue↗

Serotonin and tolerance to delay of reward in rats.

RATIONALE: Tolerance to delay of gratification, taken to reflect impulsiveness, has been proposed to be under the preferential control of central serotonin (5-HT) processes. OBJECTIVE: The present study further examined the effects of drugs which directly or indirectly alter 5-HT transmission, on behaviour controlled by a delayed positive reinforcer. METHODS: Rats were given the choice in a T-maze between two magnitudes of reward: small (two food pellets) and immediate versus large (ten pellets) but delayed. When a 15-s waiting period was imposed in the arm leading to the large reward, rats selected this arm on 65-70% of the trials. This frequency was reduced to less than 40% when the large reward was delayed by 25 s. RESULTS: In rats whose ascending 5-HT pathways had been lesioned by infusion of 5,7-dihydroxytryptamine (5,7-DHT) into the dorsal raphe, the introduction of the 15-s delay contingency resulted in a transient larger reduction of the frequency of choice of the now-delayed reward, compared to sham operated controls. In contrast, choice behaviour of rats given 5,7-DHT into the substantia nigra did not differ from controls. para-Chlorophenylalanine (pCPA, 150 mg/kg IP, daily for 3 days), a 5-HT synthesis inhibitor, bretazenil (0.5-8 mg/kg IP), a benzodiazepine (BZD) receptor partial agonist, and muscimol (0.25-1 mg/kg IP), a GABA(A) receptor agonist, induced a shift toward immediate reward. In contrast to the other BZDs, alprazolam (1-2 mg/kg IP) enhanced the frequency of choice of the large-but-25 s-delayed reward. Similar increased preference for the large-but-delayed reward was induced by the selective 5-HT reuptake inhibitors, fluoxetine (4-8 mg/kg IP) and fluvoxamine (4 mg/kg IP). The full 5-HT(1A) receptor agonist, 8-OH-DPAT (0.015-0.5 mg/kg IP) enhanced the frequency of choice of the large reward delayed by 25 s, whereas the partial agonists, buspirone (1-4 mg/kg IP), ipsapirone (0.5-1 mg/kg IP) and MDL 73005EF (1-2 mg/kg SC), and the antagonist, WAY 100635 (4 mg/kg SC), reduced the number of choices of the large reward delayed by 15 s. Unexpectedly, WAY 100635 (2 mg/kg), which had no effect on choice whatever the delay, did not counteract the increased tolerance to delay induced by 8-OH-DPAT (0.06 mg/kg) and further reduced the frequency of choice of the large-but- 15 s-delayed reward induced by ipsapirone (0.5 mg/kg). CONCLUSIONS: These effects on tolerance to delay may be accounted for by a subtle balance between the opposing functional consequences of pre- versus post-synaptic 5-HT(1A) receptor activation or blockade. Overall, the present results provide further support to the idea that 5-HT processes participate in the control of impulsive-related behaviour, as assessed from tolerance to delay of reward in this particular T-maze procedure.

5,7-Dihydroxytryptamine↗

Effects of chronic antidepressants in an operant conflict procedure of anxiety in the rat.

The effects of chronic antidepressants were investigated in an animal procedure for the study of anxiety and anxiolytics, the conditioned suppression of operant behavior in rats. In daily 18-min sessions, three periods of nonpunished lever pressing for food alternated with two 4-min periods signaled by a light-on conditioned stimulus during which 50% of the responses were randomly punished by electric foot shocks. Antidepressants were administered once daily for 7-8 weeks to trained, food-restricted rats. Desipramine (dose regimen increase from 4 to 16 mg/kg/day) induced a gradual (4-5-week latency) release of response suppression during punished periods over the course of several weeks of testing. This anxiolytic-like effect was still present 3 weeks following drug discontinuation. In contrast, chronic imipramine (dose regimen increase from 4 to 16 mg/kg/day), maprotiline (4 to 16 mg/kg/day), phenelzine (2 to 4 mg/kg/day), and fluoxetine (1 or 8 mg/kg/day; constant dose), resulted in no change in punished responding, suggesting that no anxiolytic-like effect developed in the course of chronic treatment with these compounds. The largest dose of all antidepressants studied (except fluoxetine) induced a moderate to marked reduction of nonpunished performance that disappeared within 1 week after the last injection. A transient release of conditioned response suppression emerged during the week that followed discontinuation of imipramine, maprotiline, and fluoxetine (8 mg/kg/day). This apparent anxiolytic-like activity might be due to a reduction of some adverse effect induced by the high doses used, and/or might have resulted from a new dynamic equilibrium between monoamine release, reuptake processes, and sensitivity of postsynaptic receptors. In conclusion, operant conflict procedures in rats seem not particularly able to model human anxiety sensitive to chronic antidepressant treatments.

Animals↗

ICAM-3 and E-selectin endothelial cell expression differentiate two phases of angiogenesis in infantile hemangiomas.

Cellular adhesion molecules are newly identified mediators of angiogenesis. Infantile hemangiomas, characterized in the early stages by a proliferation of poorly differentiated vessels followed in the late stages by a vascular differentiation and regression of the tumor, represent an interesting model to study angiogenesis. We studied by immunohistochemistry the distribution of HLA-DR and three adhesion molecules ICAM-3, E-selectin and VCAM-1 on endothelial cells in different stages of vessel differentiation in infantile hemangiomas. We found high levels of ICAM-3 expression on proliferating vessels, while its expression was low or undetectable on well differentiated vessels. A different set of E-selectin antibodies showed a more heterogenous pattern of distribution and VCAM-1 antigens were found in both proliferating and differentiated vessels. HLA-DR expression on endothelial cells was inversely correlated to the vascular differentiation. Our results are consistent with the hypothesis that ICAM-3 plays a role in the early stages of vessel formation. Our results also suggest that variation of E-selectin and HLA-DR expression may be related either to vessel differentiation or may reflect the acquisition of an activated endothelial cell status.

Antigens, CD↗

[A clinical study of chronic perennial and permanent rhino-sinusal dysfunction. II. Clinical pattern of different pathologies].

Following a univariate analysis of the clinical features of chronic perannual and permanent rhinosinus dysfunction, the aim of this work was to complete the study by a multivariate analysis. The analysis was based on the three main pathologies retained (chronic sinusitis, bilateral symmetrical pansinusitis, anterior facial sinusitis). Each pathological situation was divided into subgroups, Phadiatop positive or negative chronic rhinitis, bilateral symmetrical chronic panethmoiditis or stage I, II or III naso-sinus polyposis, maxillary sinusitis or anterior facial pansinusitis. The clinical features of these different entities were detailed (number, quality and laterality of the symptoms, results of the physical examination). This clinical description was compared with paraclinical findings, particularly computed tomography of the face.

Cerebrospinal Fluid Rhinorrhea↗

Harmful long-term impact of hepatitis C virus infection in kidney transplant recipients.

BACKGROUND: The long-term impact of hepatitis C virus (HCV) infection in renal transplant recipients remains controversial. We report here our experience, in a homogeneous single center, of 499 patients with a fairly long follow-up. METHODS: We retrospectively studied 499 hepatitis B virus-negative patients who received an initial cadaver donor kidney transplantation at Necker Hospital between January 1, 1979 and December 31, 1994, with a graft or patient survival of at least 6 months. Anti-HCV antibodies were detected at time of transplantation in 112 patients (22%). Patient survival and causes of death were compared among anti-HCV-positive and -negative patients RESULTS: Our results clearly indicate that first cadaver kidney transplant recipients with anti-HCV antibodies had a significantly shorter patient and graft long-term survival than recipients without anti-HCV antibodies (P<0.01 and P<0.0001 respectively). Mean follow-up time after transplantation was 79+/-2 months in the former group and 81+/-5 months in the latter (NS). Increased mortality was primarily caused by liver disease (P<0.001) and sepsis (P<0.01). In a multivariate analysis, HCV infection significantly affected the mortality rate (odds ratio: 2.8). CONCLUSIONS: These results suggest that HCV infection has a harmful long-term impact on the survival of kidney transplant recipients.

Adult↗

[Semiologic study of chronic perennial and permanent paranasal sinus dysfunction. Prevalence of symptoms].

Rhino-sinus dysfunction is associated with several symptoms: nasal obstruction, anterior and posterior rhinorrhea, episodes of sneezing, painful or heavy feeling in the face, taste and smell disorders. Certain manifestations have an impact on the pharynx, the larynx or the tracheobronchial tree. This prospective study was conducted in 449 consecutive patients who consulted over an 18-months period from November 1995 to May 1997. The objective was to determine the symptom pattern, main disease of the nasal cavities and paranasal sinuses which were involved: chronic rhinitis, anterior sinusitis, bilateral and symmetric pansinusitis with or without nasosinus polyps. In the first part of the study, the frequency of different symptoms were determined for the main nasosinus diseases. Statistical analysis of the correlations between symptoms and diseases provided a specific approach to symptoms.

Adolescent↗

[The role of the national education physician in the management of child abuse].

The school physician is in a key position to detect and to report cases of child ill-treatment. He has opportunities to listen to the child himself, to collect information upon his life at school as well as on his brothers and sisters; therefore he can get an accurate knowledge of the situation of that child. Afterwards, he will meet the child's parents. Through his relationships with many partners, such as the family physician, the hospital, educators, social workers and even justice, the school physician can clear up some facts, in order to complete his view on the case. Due to his particular responsibility to cope with situations of child distress, the school physician, as an adviser inside school, shall take an active part in terms of prevention.

Child↗

Genetic transmission of susceptibility to cancer in families of children with soft tissue sarcomas.

BACKGROUND: This article presents analysis of clinical and family data for 239 patients with childhood soft tissue sarcoma (STS) treated at the Institut Gustave Roussy in Villejuif. METHODS: A molecular study was performed to detect germline p53 mutations in the 44 families in which at least 1 relative developed cancer before the age of 46 or in which the proband had a second neoplasm. Mutations were found in five families. Standardized incidence ratio calculation and segregation analysis were used to study cancer occurrence in 4448 relatives, including first- and second-degree relatives and first cousins. RESULTS: An excess of brain tumors was observed in all relatives, and of breast carcinoma and STS in first-degree relatives of patients with STS. An excess of breast carcinoma was observed only in young mothers of patients with rhabdomyosarcoma. This excess might be mostly linked to the presence of a germline p53 mutation because it was no more significant when excluding families in which such a mutation existed. No association between breast carcinoma in the mother and rhabdomyosarcoma of the genitourinary tract in the proband was observed. This should be kept in mind when developing a screening strategy for breast carcinoma in mothers of patients with STS. Segregation analysis showed evidence for transmission of an autosomal dominant gene with complete penetrance by the age of 84. The genetic component was explained primarily by p53 germline mutations. CONCLUSIONS: These results show that most relatives of patients with STS are at the same risk for cancer as the general population.

Adult↗

Cancers in relatives of children with non-Hodgkin's lymphoma.

We undertook a family study of children treated at the Institute Gustave-Roussy in France to investigate a familial aggregation of cancer in the families of children with non-Hodgkin's lymphoma (NHL). We obtained family dat for 284 children with NHL. Using the Standardized Incidence Ratio, we compared the observed and expected number of families with at least one proband relative affected by cancer at a young age (before 46 years). We found a small but non-significant excess of all tumors in first-degree relatives (SIR = 1.3, 95% CI = 0.7-2.3) explained by a small but non-significant excess of hematological malignancies (SIR = 1.5, 95% CI = 0.2-5.5), particularly Hodgkin's disease and leukemia, and of osteosarcoma (SIR = 7.5, 95% CI = 0.1-41.4). This is probably a lower bound of the SIR, because the expected number of families was estimated from cancer incidence in France between 1978 and 1982, whereas most cancers occurred before this period. Other tumors were not in excess in first-degree relatives.

Adolescent↗

ARCAD: a method for estimating age-dependent disease risk associated with mutation carrier status from family data.

We present ARCAD, a method to estimate the disease risk associated with mutation carrier status using data on families ascertained by affected individuals, in which a germline mutation has been detected. Because the event of interest, the age of onset, is a censored variable, the method uses the survival analysis approach to formulate the likelihood. Provided that selection criteria are clearly defined, the ascertainment bias is removed by including a correction term in the likelihood computation. We simulated family data and selected those with a proband affected before age 17, and at least one or at least two relatives affected before age 46. We show that including the correction for the ascertainment provides reliable estimates of the risk, even when many individuals are not tested for the mutation. An application to cancer risk and germline p53 mutations is presented. We routinely investigate the p53 status for all the children treated in the Department of Pediatric Oncology at the Institute Gustave Roussy, whose family displays at least one relative affected by cancer before age 46. We identified 5 families with an inherited germline p53 mutation. The risk for any cancer for a mutation carrier estimated by ARCAD was 42% within the age class 0-16 years, 38% within the age class 17-45 years, and 63% after 45 years, with a lifetime risk of 85%. These risks are almost entirely explained by the occurrence of the six most frequent cancers encountered in the Li-Fraumeni syndrome.

Adolescent↗