Evaluation of the hypothalamic-pituitary-adrenal axis and its relationship with central respiratory dysfunction in children with Prader-Willi syndrome.

BACKGROUND: Children with Prader-Willi Syndrome (PWS) have been considered at risk for central adrenal insufficiency (CAI). Hypothalamic dysregulation has been proposed as a common mechanism underlying both stress-induced CAI and central respiratory dysfunction during sleep. OBJECTIVE: To evaluate CAI and sleep-related breathing disorders in PWS children. PATIENTS AND METHODS: Retrospective study of cortisol response following either insulin tolerance test (ITT) or glucagon test (GT) in 20 PWS children, and comparison with 33 non- Growth Hormone deficient (GHD) controls. Correlation between sleep related breathing disorders and cortisol response in 11 PWS children who received both investigations. RESULTS: In PWS children, the cortisol peak value showed a significant, inverse correlation with age (Kendall's τ = -0.411; p = 0.012). A similar though non-significant correlation was present between cortisol increase and age (τ = -0.232; p = 0.16). Similar correlations were found in controls. In only 1 of 20 PWS children (5 %), ITT was suggestive of CAI. Four patients had an elevated central apnea index but they all exhibited a normal cortisol response. No relationship was found between peak cortisol or cortisol increase and central apnea index (respectively p = 0.94 and p = 0.14) or the other studied polysomnography (PSG) parameters. CONCLUSIONS: CAI assessed by ITT/GT is rare in PWS children. Our data do not support a link between CAI and central respiratory dysregulation.

Concerns, expectations and perception regarding stature, physical appearance and psychosocial functioning before and during high-dose growth hormone treatment of short pre-pubertal children born small for gestational age.

BACKGROUND/AIMS: Few data are available about parental concerns and psychosocial functioning of young children born small for gestational age (SGA) treated with growth hormone (GH). The present study focused on the perception of short stature and the concerns and expectations of the parents regarding GH treatment. METHODS: Forty prepubertal short SGA children, randomized into a GH-treated and a GH-untreated group, and their parents were evaluated by a questionnaire and a semi-structured interview at start and after 2 years of follow-up. RESULTS: Before start, 85% of the parents were concerned about short stature, 76% expected an increase in adult height of > or =10 cm and 81% expected a positive impact on well-being. Half of the parents expressed fears regarding GH treatment. After 2 years, more parents of treated children reported obvious growth and physical changes, and fewer parents reported teasing because of short stature. An improvement of well-being was reported by half of the parents of treated and untreated children. Fears about GH treatment disappeared almost completely. CONCLUSION: The perspective of GH treatment induced major adult height expectations. In treated children, the physical effects of GH treatment became obvious, teasing because of short stature decreased and initial concerns about short stature and GH therapy decreased.

Renal functional changes in relation to hemodynamic parameters during exercise test in normoalbuminuric insulin-dependent children.

AIM: To examine the relationship between filtration fraction and systemic vasculopathy, in normoalbuminuric insulin-dependent diabetic adolescents. METHODS: We calculated filtration fraction from measured glomerular filtration rate and renal plasma flow during a hypotonic saline perfusion test in 30 normotensive adolescent diabetic patients (9-19 years), with a mean duration of diabetes of 7.4 years. Blood pressure and heart rate were measured in basal conditions, during a 24-h ambulatory monitoring and during a dynamic exercise test on a cycle ergometer and peripheral vascular resistance was calculated. RESULTS: Filtration fraction was increased in the diabetic children compared with controls (30+/-6% vs. 22+/-4%, p<0.001), while renal plasma flow was significantly lower (453+/-133 mL/min/1.73 m2 vs. 593+/-155 mL/min/1.73 m2, p<0.001). Peripheral vascular resistance was significantly higher at peak exercise in diabetic children compared to controls (16.3+/-1.3 mmHg/L min m2 vs. 11.4+/-0.5 mmHg/L min m2, p<0.01). CONCLUSION: These results indicate that in young patients with IDDM, without apparent nephropathy or apparent systemic vasculopathy, filtration fraction is increased, suggesting an increased intraglomerular pressure. The associated reduced decrease of peripheral vascular resistance (increased diastolic blood pressure during exercise) suggests that renal functional abnormalities may be partly explained by a systemic vasculopathy, also present in the kidney.

Effect of 2 years of high-dose growth hormone therapy on cognitive and psychosocial development in short children born small for gestational age.

OBJECTIVE AND DESIGN: Children born small for gestational age (SGA) are not only at risk for short stature, but also for neurodevelopmental and behavioral problems. In this study, we analyzed the effects of high-dose GH therapy on cognitive development and psychosocial functioning in 34 prepubertal (3-8 years) short SGA children, equally randomized into a GH-treated group (TRG) and an untreated group (UTRG). METHODS: At start and after 2 years, children underwent standardized tests measuring the intellectual abilities (Wechsler Preschool and Primary Scale of Intelligence-Revised, or Wechsler Intelligence Scale for Children-Revised); their parents completed a standardized questionnaire evaluating psychosocial functioning (Child Behavior Checklist; CBCL). RESULTS: At start, total IQ scores were significantly (P < 0.05) lower in the SGA group than in the general population: 32% of the SGA patients had scores below 85. After 2 years, IQ scores remained unchanged in the TRG, but increased significantly (P < 0.05) in the UTRG. After exclusion of children with developmental problems, however, no significant changes in IQ scores occurred in the UTRG as well as the TRG. At baseline, 24% (8/34) children had problematic CBCL total problems scores, equally distributed among the two groups; no significant changes in the different subscale scores occurred after 2 years. CONCLUSION: No beneficial effect of 2 years of GH therapy on cognitive and behavioral profile could be observed in a cohort of rather young short SGA children presenting a variable degree of developmental delay and behavioral problems. Subsequent follow-up could reveal potential long-term effects of GH therapy on development and behavior.

Trends in age at diagnosis of Turner syndrome.

The age at diagnosis of 242 girls with Turner syndrome (TS) treated in Belgium with growth hormone between 1991 and 2002 was evaluated. The median (range) age at diagnosis was 6.6 (0-18.3) years. Patients with 45,X karyotype were diagnosed earlier than patients with other karyotypes. Compared to a previous survey, performed on 100 patients 12 years earlier, more patients were diagnosed during infancy and childhood, and less during adolescence. However, in 22% of the girls the diagnosis was made after the age of 12 years; these girls showed the largest height deficit. As early diagnosis has several potential advantages we recommend that a cytogenetic analysis should be considered in all girls with unexplained short stature with height below -2 SD of the mean for age or below the parent specific lower limit of height.

Health and psychosocial status of patients with turner syndrome after transition to adulthood: the Belgian experience.

BACKGROUND: Most girls with Turner syndrome (TS) are intensively followed by paediatricians, but are lost to follow-up when they reach adulthood. To gain insight into the adult medical and psychosocial situation, we performed a survey in young adult TS patients. PATIENTS AND METHODS: A questionnaire concerning current health status, education, occupation and living situation was sent to 160 young adult TS women, all treated during childhood with GH and oestrogen if needed. RESULTS: We received 102 completed questionnaires. Mean +/- SD age at reception of the questionnaire was 23.4 +/- 3.3 years, height 153.3 +/- 5.2 cm, body mass index 23.7 +/- 4.9 kg/m(2). Age and auxological parameters were comparable between responders and non-responders. Thirteen (12.7%) responders were not under regular medical care; 15 (14.7%) were seen by a general practitioner, while 28 (27.4%) needed several specialists. Forty-one (40.2%) patients reported health problems. The most frequently reported problem was hypertension (10.7%), followed by hypothyroidism (5.8%) and back problems (4.9%). Twenty-four (23.5%) of the 41 patients were taking medication for the indicated health problems. Twenty-six (25.5%) women had undergone spontaneous puberty; 16 of them reported spontaneous menstruations while 10 received oestrogen replacement therapy. Of the 76 women with induced puberty, 11 (14.5%) were not taking any oestrogen anymore. Compared with the general population, more TS women attended university and more obtained higher education. Forty-six women (45.1%) were working full-time, 7 (6.9%) were unemployed, and 4 (3.9%) received an allocation. Seventy (68.6%) patients were still living with their parents, while 18 (17.6%) were living together or married, and 14 (13.7%) were living alone. CONCLUSIONS: The transition of adolescents with TS to adult medical care is not optimal in Belgium. Although 40.2% of these young women reported health problems, 12.7% did not consult any physician. Many TS women did not take oestrogen replacement therapy. A specialized multidisciplinary approach for adults with TS is needed in order to optimize health and psychosocial status in these women.

Prevalence and demographic features of childhood growth hormone deficiency in Belgium during the period 1986-2001.

OBJECTIVE: Since the availability of recombinant human growth hormone (rhGH) all children with growth hormone deficiency (GHD) living in Belgium are offered rhGH treatment after approval by a peer-review board. In this study, we evaluated the prevalence and demographic features of childhood GHD in Belgium during the period 1986-2001 and we compared them with the data from other countries. METHODS: Diagnostic, demographic and baseline auxological data of 714 children diagnosed as having GHD between 1986 and 2001 were retrieved from the database of the Belgian Study Group for Paediatric Endocrinology. RESULTS: The prevalence of GHD in Belgium was estimated to be 1/5600. The origin of GHD was idiopathic (idGHD) in 41% of the patients, congenital (congGHD) in 20% and acquired (acqGHD) in 35%. During the first 4 years (1986-1989) more patients were classified as idGHD; thereafter the distribution between the three aetiology groups did not change. In all groups, boys outnumbered girls but this preponderance was especially pronounced in congGHD patients (male:female=4:1) with a central malformation that associates an anterior pituitary hypoplasia, a missing, fine or normal pituitary stalk and an ectopic posterior pituitary. Thirteen percent of the patients with idGHD, 50% with congGHD and 52% with acqGHD had multiple pituitary deficiencies. Patients with congGHD were the youngest (mean+/-s.d. age: 6.5+/-4.7 years) and were the shortest (-3.0+/-1.3 standard deviation score (SDS)) at the start of rhGH treatment. There was no time trend over the studied period for age and height at onset of GH therapy. CONCLUSION: In Belgium, the prevalence of childhood GHD can be estimated as 1/5600 which is comparable to other recent surveys. The yearly number of new patients for the different aetiologies and the auxological parameters have remained relatively constant over the last 16 years.

Late or delayed induced or spontaneous puberty in girls with Turner syndrome treated with growth hormone does not affect final height.

Although it has been well established that GH treatment increases final height (FH) in girls with Turner syndrome (TS), the optimal ages to start GH therapy and introduce estrogens for pubertal induction have not been defined. We evaluated retrospectively the influence of the age at onset of GH treatment and age at onset of puberty on FH of 186 adult TS women treated during childhood with GH. Puberty started spontaneously in 38 patients, and it was induced in 148 girls with ethinyl estradiol (mean +/- SD starting dose, 66 +/- 32 ng/kg.d). Patients with spontaneous or induced puberty were divided into quartiles on the basis of age at initiation of GH treatment (3-10, 10-12, 12-14, and 14-19 yr). FH was 151.7 +/- 6.0 cm; there were no FH differences between patients with induced or spontaneous puberty, nor were there differences between the age quartiles. Puberty started earlier in the girls with spontaneous puberty than in those with induced puberty (12.4 +/- 1.3 yr vs. 14.5 +/- 1.9 yr; P < 0.0001). The age at onset of puberty was not related to FH. Pubertal growth was 15.4 +/- 4.6 cm in the girls with spontaneous puberty and 8.6 +/- 4.3 cm in the girls with induced puberty (P < 0.0001). We conclude that GH treatment results in a significant increase in FH in most TS girls. Under the conditions of GH treatment and induction of puberty that we have used, the age at start of GH treatment was not related to FH; in addition, late or delayed induced or spontaneous puberty did not affect FH.

Growth hormone (GH) secretion in patients with childhood-onset GH deficiency: retesting after one year of therapy and at final height.

BACKGROUND: Recent studies have shown that many patients treated with growth hormone (GH) during childhood because of idiopathic GH deficiency (GHD) are no longer GH deficient when retested after cessation of GH therapy when final height is achieved. These patients are labelled as transient GHD. We hypothesized that normalization of GH secretion in transient GHD could occur earlier during the course of GH treatment, which could allow earlier cessation of GH treatment. METHODS: In a retrospective study, GH secretion was re-evaluated after cessation of GH treatment at final height in 43 patients diagnosed during childhood as idiopathic GHD (10 with multiple pituitary hormonal deficiencies (MPHD) and 33 with isolated GHD (IsGHD)). In a prospective study, GH secretion was re-assessed after interruption of GH treatment given for 1 year in 18 children with idiopathic GHD (2 MPHD, 16 IsGHD). GH secretion was evaluated by glucagon or insulin stimulation tests. RESULTS: In the retrospective study, all the 10 patients with MPHD and 64% of the 33 patients with IsGHD were still deficient at re-evaluation using the paediatric criteria to define GHD (GH peak <10 ng/ml at provocative test). The proportion of persisting deficiency was greater in patients with complete IsGHD (86%, 12/14 patients) than in patients with partial IsGHD (47%, 9/19 patients). With the criteria proposed in adulthood (GH peak <3 ng/ml), all the 10 patients with MPHD were still considered to be deficient. In contrast, only 15% (5/33 patients) with IsGHD had a maximal GH value <3 ng/ml (36% of the 14 patients with complete IsGHD and none of the 19 patients with partial IsGHD). In the prospective study, after interruption of GH therapy given for 1 year, the 2 patients with MPHD were still GHD at re-evaluation and they resumed GH treatment. Among the 16 patients with IsGHD, 13 (81%) were still deficient (peak response <10 ng/ml) after 1 year. Two of the 3 patients in whom GHD was not confirmed at retesting after 1 year GH showed again a deficient response at second retesting. CONCLUSIONS: Although many patients diagnosed with IsGHD during childhood have a normalized GH secretory capacity when retested during adulthood, early retesting after interruption of GH treatment given for 1 year during childhood does not enable to determine if GH therapy has to be discontinued before cessation of growth.

Ophthalmologic and systemic features of the Alström syndrome: report of 9 cases.

The Alström syndrome is a rare autosomal recessive disorder characterized by pigmentary retinopathy, diabetes mellitus, sensorineural deafness and obesity. A normal intelligence is often present. We report 9 patients.

Final height in children with idiopathic growth hormone deficiency treated with recombinant human growth hormone: the Belgian experience.

BACKGROUND: The growth response to recombinant hGH (rhGH) treatment and final height of 61 Belgian children (32 boys) with idiopathic growth hormone deficiency (GHD) were studied. PATIENTS/METHODS: Two patient groups were compared: Group 1 with spontaneous puberty (n = 49), Group 2 with induced puberty (n = 12). The patients were treated with daily subcutaneous injections of rhGH in a dose of 0.5-0.7 IU/kg/week (0.17-0.23 mg/kg/week) from the mean +/- SD age of 11.9 +/- 3.1 years during 5.1 +/- 2.1 years. RESULTS: rhGH treatment induced a doubling of the height velocity during the first year and resulted in a normalisation of height in 53 (87%) patients. Final height was -0.7 +/- 1.1 SDS, being 170.4 +/- 7.2 cm in boys and 158.0 +/- 6.4 cm in girls. Corrected for mid-parental height, final height was 0.0 +/- 1.1 SDS. Ninety-two percent of the patients attained an adult height within the genetically determined target height range. Although height gain during puberty was smaller in the patients with induced puberty (boys: 17.1 +/- 7.0 cm vs. 27.5 +/- 6.6 cm (p < 0.005); girls: 9.6 +/- 7.4 cm vs. 22.2 +/- 6.1 cm (p < 0.005)), no differences in final height after adjustment for mid-parental height were found between patients with spontaneous or induced puberty. CONCLUSIONS: We conclude that patients with idiopathic GHD treated with rhGH administered as daily subcutaneous injections in a dose of 0.5-0.7 IU/kg/week reach their genetic growth potential, resulting in a normalisation of height in the majority of them, irrespective of spontaneous or induced puberty.

Sexual precocity after immigration from developing countries to Belgium: evidence of previous exposure to organochlorine pesticides.

In a retrospective auxological study of 145 patients seen in Belgium during a 9-year period for treatment of precocious puberty, 28% appeared to be foreign children (39 girls, one boy) who immigrated 4 to 5 years earlier from 22 developing countries, without any link to a particular ethnic or country background. The patients were either adopted (n = 28) or non-adopted (n = 12), the latter having normal weight and height at immigration and starting early puberty without evidence of earlier deprivation. This led to the hypothesis that the mechanism of precocious puberty might involve previous exposure to oestrogenic endocrine disrupters. A toxicological plasma screening for eight pesticides detected p,p'-DDE, which is derived from the organochlorine pesticide DDT. Median p,p'-DDE concentrations were respectively 1.20 and 1.04 ng/ml in foreign adopted (n = 15) and non-adopted (n = 11) girls with precocious puberty, while 13 out of 15 Belgian native girls with idiopathic or organic precocious puberty showed undetectable concentrations (<0.1 ng/ml). A possible relationship between transient exposure to endocrine disrupters and sexual precocity is suggested, and deserves further studies in immigrant children with non-advanced puberty.

Quality of life and retrospective perception of the effect of growth hormone treatment in adult patients with childhood growth hormone deficiency.

Divergent findings on the quality of life (QoL) and the psychosocial functioning of adults treated during childhood with growth hormone (GH) because of GH deficiency (GHD) have been reported. In the present study we evaluated the QoL and the perception of the effect of former GH treatment in Belgian young adults with childhood GHD. Thirty-six patients (22 males) were included in the study. They all were treated during childhood with GH for GHD. QoL was evaluated with a standardised questionnaire: the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA). Psychosocial functioning, sexual experience and schooling were evaluated by semi-structured interviews and questionnaires. The influence of gender, type of hormone deficiency (isolated GHD vs multiple pituitary hormone deficiencies [MPHD]), age at the start of GH therapy (before 12 yr vs after 12 yr) and the height deficit at the start of GH therapy (< -3 SDS vs > -3 SDS) were studied. In addition, the patients' and parents' perception of height and of the effect of GH treatment was retrospectively evaluated by semi-structured interviews. Age (mean +/- SD) at the time of evaluation was 20.0 +/- 1.3 yr and final height was -0.5 +/- 0.9 SDS, comparable to mid-parental height (-0.6 +/- 0.8 SDS). The QoL-AGHDA score was 9 +/- 6. About half of the patients, especially those in whom GH treatment was started after the age of 12 years, complained of retrospective difficulties with self-confidence and social contact, and about one-quarter of the patients had current difficulties with self-confidence, social contact, contact with the opposite sex and with emotional life. Only 44% of the patients had had sexual intercourse--none of those with MPHD. According to the parents, the patients had and still have more difficulties with self-confidence and social contact than their siblings and/or peers, and they needed and still need more emotional support. In one out of four patients the parents expected difficulties in finding a job, in one out of three patients parents expected difficulties in leaving home or in having a stable relationship. The educational level of patients with a height deficit < -3 SDS at start of GH therapy was lower than in patients with a height deficit > -3 SDS. According to the parents, about half of the patients, especially those with MPHD, had more study problems compared to siblings. In all patients, satisfaction with final height and GH therapy was obvious. In conclusion, the psychosocial outcome of young adults with childhood GHD was more satisfying than in previous studies. This could be due to a more adequate GH treatment with better final height results. Nevertheless, more difficulties with respect to psychosocial functioning were observed in patients with MPHD, in patients in whom GH treatment was started after 12 years of age and in patients with a height deficit < -3 SDS at the start of GH therapy, underlining the need for early diagnosis and treatment of childhood GHD, and of continuing medical follow-up and psychosocial counselling, particularly in these subgroups of patients with GHD.

The endothelial monocyte-activating polypeptide II (EMAP II) is a substrate for caspase-7.

Endothelial monocyte-activating polypeptide II (EMAP II) is a proinflammatory cytokine and a chemoattractant for leukocytes. The mature cytokine is formed in apoptotic cells by cleavage of the precursor proEMAP II. Here we show that caspase-7 is capable of cleaving proEMAP II in vitro. A proEMAP II mutant, in which the ASTD cleavage site was changed to the sequence ASTA, was not processed by caspase-7. The caspase-7-mediated generation and release of mature EMAP II may provide a mechanism for leukocyte recruitment to sites of programmed cell death, and thus may link apoptosis to inflammation.

The proteolytic procaspase activation network: an in vitro analysis.

In general, apoptotic stimuli lead to activation of caspases. Once activated, a caspase can induce intracellular signaling pathways involving proteolytic activation of other caspase family members. We report the in vitro processing of eight murine procaspases by their enzymatically active counterparts. Caspase-8 processed all procaspases examined. Caspase-1 and -11 processed the effector caspases procaspase-3 and -7, and to a lesser extent procaspase-6. However, vice versa, none of the caspase-1-like procaspases was activated by the effector caspases. This suggests that the caspase-1 subfamily members either act upstream of the apoptosis effector caspases or else are part of a totally separate activation pathway. Procaspase-2 was maturated by caspase-8 and -3, and to a lesser extent by caspase-7, while the active caspase-2 did not process any of the procaspases examined, except its own precursor. Hence, caspase-2 might not be able to initiate a wide proteolytic signaling cascade. Additionally, cleavage data reveal not only proteolytic amplification between caspase-3 and -8, caspase-6 and -3, and caspase-6 and -7, but also positive feedback loops involving multiple activated caspases. Our results suggest the existence of a hierarchic proteolytic procaspase activation network, which would lead to a dramatic increase in multiple caspase activities once key caspases are activated. The proteolytic procaspase activation network might allow that different apoptotic stimuli result in specific cleavage of substrates responsible for typical processes at the cell membrane, the cytosol, the organelles, and the nucleus, which characterize a cell dying by apoptosis.

GAL4 is a substrate for caspases: implications for two-hybrid screening and other GAL4-based assays.

Yeast two-hybrid technology as well as mammalian reporter assays use fusions between a protein of interest and the GAL4 DNA-binding domain (GAL4DB). We demonstrate that expression of a GAL4DB/caspase-1 chimeric protein in yeast leads to autoproteolytic cleavage of GAL4DB. Moreover, recombinant GAL4DB is a good in vitro substrate for recombinant caspase-1 and several other caspases. Cleavage sites map at the C-terminus of GAL4DB and result in release of the fused protein. The finding that GAL4DB can be cleaved by caspases has important implications for the use of caspases in two-hybrid analysis and in the interpretation of mammalian assays based on GAL4-dependent reporter gene expression.

Caspase-induced proteolysis of the cyclin-dependent kinase inhibitor p27Kip1 mediates its anti-apoptotic activity.

The caspase-mediated cleavage of a limited number of cellular proteins is a common feature of apoptotic cell death. This cleavage usually inhibits the function of the target protein or generates peptides that actively contribute to the death process. In the present study, we demonstrate that the cyclin-dependent kinase inhibitor p27Kip1 is cleaved by caspases in human leukemic cells exposed to apoptotic stimuli. We have shown recently that p27Kip1 overexpression delayed leukemic cell death in response to cytotoxic drugs. In transient transfection experiments, the p23 and the p15 N-terminal peptides generated by p27Kip1 proteolysis demonstrate an anti-apoptotic effect similar to that induced by the wild-type protein, whereas cleavage-resistant mutants have lost their protective effect. Moreover, stable transfection of a cleavage-resistant mutant of p27Kip1 sensitizes leukemic cells to drug-induced cell death. Altogether, these results indicate that proteolysis of p27Kip1 triggered by caspases mediates the anti-apoptotic activity of the protein.

Proteolytic cleavage of beta-catenin by caspases: an in vitro analysis.

Cleavage of structural proteins by caspases has been associated with the severe morphological changes occurring during the apoptotic process. One of the proteins regulating the connection of the actin filament with cadherins in a cell-cell adhesion complex is beta-catenin. During apoptosis, both an N-terminal and a small C-terminal part are removed from beta-catenin. Removal of the N-terminal part may result in a disconnection of the actin filament from a cadherin cell-cell adhesion complex. We demonstrate that caspase-8, -3 and -6 directly proteolyse beta-catenin in vitro. However, the beta-catenin cleavage products generated by caspase-8 were different from those generated by caspase-3 or caspase-6. Caspase-1, -2, -4/11 and -7 did not or only very inefficiently cleave beta-catenin. These data suggest that activation of procaspase-3, -6 or -8 by different stimuli in the cell might result in a differential proteolysis of beta-catenin.