Minimal methylation classifier (MIMIC): A novel method for derivation and rapid diagnostic detection of disease-associated DNA methylation signatures.

Rapid and reliable detection of disease-associated DNA methylation patterns has major potential to advance molecular diagnostics and underpin research investigations. We describe the development and validation of minimal methylation classifier (MIMIC), combining CpG signature design from genome-wide datasets, multiplex-PCR and detection by single-base extension and MALDI-TOF mass spectrometry, in a novel method to assess multi-locus DNA methylation profiles within routine clinically-applicable assays. We illustrate the application of MIMIC to successfully identify the methylation-dependent diagnostic molecular subgroups of medulloblastoma (the most common malignant childhood brain tumour), using scant/low-quality samples remaining from the most recently completed pan-European medulloblastoma clinical trial, refractory to analysis by conventional genome-wide DNA methylation analysis. Using this approach, we identify critical DNA methylation patterns from previously inaccessible cohorts, and reveal novel survival differences between the medulloblastoma disease subgroups with significant potential for clinical exploitation.

Atopic conditions and brain tumor risk in children and adolescents--an international case-control study (CEFALO).

BACKGROUND: A number of epidemiological studies indicate an inverse association between atopy and brain tumors in adults, particularly gliomas. We investigated the association between atopic disorders and intracranial brain tumors in children and adolescents, using international collaborative CEFALO data. PATIENTS AND METHODS: CEFALO is a population-based case-control study conducted in Denmark, Norway, Sweden, and Switzerland, including all children and adolescents in the age range 7-19 years diagnosed with a primary brain tumor between 2004 and 2008. Two controls per case were randomly selected from population registers matched on age, sex, and geographic region. Information about atopic conditions and potential confounders was collected through personal interviews. RESULTS: In total, 352 cases (83%) and 646 controls (71%) participated in the study. For all brain tumors combined, there was no association between ever having had an atopic disorder and brain tumor risk [odds ratio 1.03; 95% confidence interval (CI) 0.70-1.34]. The OR was 0.76 (95% CI 0.53-1.11) for a current atopic condition (in the year before diagnosis) and 1.22 (95% CI 0.86-1.74) for an atopic condition in the past. Similar results were observed for glioma. CONCLUSIONS: There was no association between atopic conditions and risk of all brain tumors combined or of glioma in particular. Stratification on current or past atopic conditions suggested the possibility of reverse causality, but may also the result of random variation because of small numbers in subgroups. In addition, an ongoing tumor treatment may affect the manifestation of atopic conditions, which could possibly affect recall when reporting about a history of atopic diseases. Only a few studies on atopic conditions and pediatric brain tumors are currently available, and the evidence is conflicting.

Patterns of exposure to infectious diseases and social contacts in early life and risk of brain tumours in children and adolescents: an International Case-Control Study (CEFALO).

BACKGROUND: Infectious diseases and social contacts in early life have been proposed to modulate brain tumour risk during late childhood and adolescence. METHODS: CEFALO is an interview-based case-control study in Denmark, Norway, Sweden and Switzerland, including children and adolescents aged 7-19 years with primary intracranial brain tumours diagnosed between 2004 and 2008 and matched population controls. RESULTS: The study included 352 cases (participation rate: 83%) and 646 controls (71%). There was no association with various measures of social contacts: daycare attendance, number of childhours at daycare, attending baby groups, birth order or living with other children. Cases of glioma and embryonal tumours had more frequent sick days with infections in the first 6 years of life compared with controls. In 7-19 year olds with 4+ monthly sick day, the respective odds ratios were 2.93 (95% confidence interval: 1.57-5.50) and 4.21 (95% confidence interval: 1.24-14.30). INTERPRETATION: There was little support for the hypothesis that social contacts influence childhood and adolescent brain tumour risk. The association between reported sick days due to infections and risk of glioma and embryonal tumour may reflect involvement of immune functions, recall bias or inverse causality and deserve further attention.

Health and persistent functional late effects in adult survivors of childhood CNS tumours: a population-based cohort study.

Survivors of central nervous system (CNS) tumours are particularly vulnerable to tumour- and treatment-related disability. We present the incidence of specific and overall functional and health-related late effects in a national adult survivor cohort. Diagnostic subgroups at particular risk for persistent sequels are identified. Data collection targeted 708 eligible >18 years old survivors, 708 parent proxies and 1000 general population controls. Functional disability including sensory and cognitive impairment, emotional status and pain was assessed using the Health Utilities Index Mark 2/3 (HUI2/3). Survivors and controls, and diagnostic subgroups were contrasted to identify the general and relative risk for late effects by sub-diagnosis. Survivors had persistent late effects in sensation, mobility, self-care and cognition. Deficits in these domains indicated clinically important disability in overall health, although indices of emotion and pain were unaffected compared to controls. Late effects tended to aggravate with time, and female survivors had poorer health. Oligodendroglioma, mixed/unspecified glioma, intracranial germ cell tumour and medulloblastoma survivors had poorest overall health. Least late effects were found for other specified/unspecified CNS tumours (including meningeoma and nerve sheath tumours), and for astrocytoma. An impact on educational, vocational and family-related outcomes, and higher utilisation of social insurance or government subsidies validated health-related sequelae in adulthood. Comparisons with controls confirm persistent disability in multiple functional domains in adult CNS tumour survivors. The heightened proportion of survivors presenting severe disability is a factor that specifically differentiates survivors from controls, although diagnostic subgroups differ significantly regarding the amount and severity of late effects.

Parental fears following their child's brain tumor diagnosis and treatment.

The objective of this study is to portray the illness-related threats experienced by parents of children after the diagnosis of central nervous system (CNS) tumor. Parents were asked to rate the extent to which they experienced a set of specific fears related to their child's brain tumor and its treatment. Outcomes for parents of CNS tumor patients (n = 82) were compared with those of reference parents of patients treated for acute lymphoblastic leukemia (n = 208). The fears about an illness recurrence and the late effects of treatment were most prominent among parents of CNS tumor patients. For 7 out of 11 kinds of fear, parents of CNS tumor patients expressed a stronger fear than the reference group. More than a quarter of the parents of children treated for CNS tumors feared a complete decline of the child. Parents of CNS tumor patients experience relatively heightened cancer related fears in several domains. The fear of devastating consequences felt by one fourth of parents signals the need of individualized psychological support and information at diagnosis and follow-up to facilitate parental coping with the posttreatment situation.

Exercise echocardiography reveals subclinical cardiac dysfunction in young adult survivors of childhood acute lymphoblastic leukemia.

OBJECTIVE: Anthracyclines (AC) have contributed significantly to increased survival rate in acute lymphoblastic leukemia (ALL), although the use of these drugs is limited due to cardiotoxicity. The aim was to evaluate heart muscle function in asymptomatic adult survivors of ALL treated in early childhood in relation to the combined effects of AC and other potential cardiotoxic factors. PROCEDURE: Twenty-three young adult ALL survivors who had all received treatment with median 120 (120-400) mg AC/m(2) before the onset of puberty were examined median 21 years after remission and compared with 12 healthy controls. Basal echocardiography including two-dimensional (2D) M-mode and Doppler examination was performed, followed by a maximal exercise stress test and stress echocardiography immediately after stress test and after 5 min recovery. RESULTS: We found significant differences in systolic function between patients and controls at maximal exercise despite absence of reported symptoms from the patients. The most marked difference was in ejection fraction at stress 59.5% (32.6-81.1) and 77.3% (66.2-85.3), respectively (P < 0.00006). Ten out of 23 patients reduced their ejection fraction at stress compared with at rest; this was not found in any of the controls. Cardiovascular risk factors such as GH deficiency and a high proportion of trunk fat did not have an impact on cardiac function. CONCLUSIONS: With very long follow up in a homogenous cohort of ALL survivors, we found subclinical cardiac dysfunction with exercise stress echocardiography even after low doses of AC.

Bone mineral density and bone turnover in young adult survivors of childhood acute lymphoblastic leukaemia.

OBJECTIVE: Treatment for childhood leukaemia induces many risk factors for development of decreased bone mineral density (BMD). Physical activity is also known to affect BMD. The aim was to study BMD and markers of bone turnover in a well-defined group of survivors of acute lymphoblastic leukaemia (ALL) who had all reached final height as well as peak bone mass, taking both previous treatment and physical activity into consideration. DESIGN: All patients treated for ALL before the onset of puberty in the region of western Sweden, between 1973 and 1985, in first remission were included. Thirty-five out of forty-seven patients aged 20-32 years participated. Nineteen patients had received cranial radiotherapy, and the median follow-up time was 20 years. METHODS: BMD was assessed using dual-energy X-ray absorptiometry (DEXA). Serum concentrations of markers of bone turnover were analysed. Physical performance was measured using a performance exercise capacity stress test. RESULTS: BMD was slightly reduced in lumbar spine (-0.4 SD), but not in femoral neck or total body. BMD in femoral neck was correlated to physical performance and dose of corticosteroid, but no correlation was found with spontaneous growth hormone (GH) secretion. Markers of bone turnover were also correlated to physical performance, but not to GH secretion. CONCLUSIONS: Physical fitness seems to be the most important factor in developing and preserving normal bone mineral density in ALL patients. We propose that lifestyle education promoting physical activity is encouraged from an early point in time for these patients.

Body composition in young adult survivors of childhood acute lymphoblastic leukaemia.

OBJECTIVE: Obesity is frequently reported in patients treated for childhood leukaemia. Obesity, particularly abdominal obesity, is one of the main characteristics of the metabolic syndrome and a risk factor for cardiovascular disease and non-insulin-dependent diabetes mellitus (NIDDM). DESIGN: All patients treated for acute lymphoblastic leukaemia (ALL) before the onset of puberty in the region of western Sweden, between 1973 and 1985, and in first remission, were included. 35 out of 47 patients aged 20-32 years participated. 19 patients had received cranial radiotherapy, and the median follow-up time was 20 years. The focus of this report was to study body composition and signs of the metabolic syndrome and correlate the findings to spontaneous growth hormone (GH) secretion. METHODS: Body composition was assessed using dual-energy X-ray absorbtiometry (DEXA). We analyzed serum concentrations of insulin, glucose, leptin and lipids. RESULTS: No patient was obese according to World Health Organization criteria (body mass index, BMI > or = 30 kg/m2) but one-third were overweight (BMI 25-29.9 kg/m2). The maximal GH peak during 24 h (GHmax) was correlated to percentage of total body fat (r = -0.42; P = 0.017), trunk fat (r = -0.5; P = 0.005) and fat-free mass (r = 0.42; P = 0.017). GHmax was also correlated to s-triglycerides (r = -0.54; P = 0.001), low-density lipoprotein-cholesterol (r = -0.382; P = 0.024) and high-density lipoprotein-cholesterol (r = 0.45; P = 0.007). CONCLUSIONS: We found little effect on BMI but an increased percentage of total body fat, especially trunk fat, and a tendency for an unfavourable lipid profile in adult survivors of childhood leukaemia. These findings were related to low endogenous GH secretion due to cranial irradiation.

Irradiation-induced progenitor cell death in the developing brain is resistant to erythropoietin treatment and caspase inhibition.

One hemisphere of postnatal day 8 (P8) rats or P10 mice was irradiated with a single dose of 4-12 Gy, and animals were killed from 2 h to 8 weeks after irradiation (IR). In the subventricular zone (SVZ) and the granular cell layer (GCL) of the dentate gyrus, harboring neural and other progenitor cells, nitrosylation and p53 peaked 2-12 h after IR, followed by markers for active caspase-3, apoptosis-inducing factor and TUNEL (6-24 h). Ki67-positive (proliferating) cells had disappeared by 12 h and partly reappeared by 7 days post-IR. The SVZ and GCL areas decreased approximately 50% 7 days after IR. The development of white matter was hampered, resulting in 50-70% less myelin basic protein staining. Pretreatment with erythropoietin did not confer protection against IR. Caspase inhibition by overexpression of XIAP prevented caspase-9 and caspase-3 activation but not cell death, presumably because of increased caspase-independent cell death.

Young adult survivors of childhood acute lymphoblastic leukemia: spontaneous GH secretion in relation to CNS radiation.

BACKGROUND: Young adults who are long-term survivors of acute lymphoblastic leukaemia (ALL) in early childhood usually do well and do not have to go to regular medical checkups. Many of these survivors did receive prophylactic cranial radiotherapy during their oncological treatment. The effect of cranial irradiation on the hypothalamus is considered to be progressive. Therefore, late effects, such as reduced growth hormone (GH) secretion, may remain undetected until adulthood. PROCEDURE: Records from all patients treated for ALL before the onset of puberty in the region of West Sweden, between 1 January 1973 and 31 December 1985 were included, provided they were in first remission with a minimum follow-up time of 15 years, and a minimum age of 20. These criteria were met by 47 young adults aged 20-32 years, of whom 35 agreed to participate. We studied spontaneous GH secretion over 24 hr, IGF-I and IGFBP-3, final height and BMI. The patients had been treated according to three consecutive Swedish childhood leukaemia group protocols. The median follow-up time was 20 years, and 19 of the patients had been treated with cranial irradiation (CRT+), 16 had not (CRT-). RESULTS: CRT+ patients had significantly lower maximal peaks of GH than CRT- patients. Fifty percent of the CRT+ patients had a GH(max) below the cut-off level (3.3 microg/l), for GH treatment. CRT- patients all had GH(max) levels considered within the normal range. Final height of all the patients, except one CRT+ women, was in the range of expected midparental height, the median loss in final height in the CRT+ patients was 0.8 standard deviation (SD). No patient in this study was obese by definition (BMI <30 kg/m(2)). IGF-I and IGFBP-3 concentrations did not correlate to variations in spontaneous GH secretion in these patients. CONCLUSIONS: In spite of the little effect on final height, we found impaired spontaneous GH secretion in 79% of young adults 20-32 years of age, and GH deficiency (GHD) in 47% after low-dose cranial irradiation in early childhood. The consequences of this low-GH secretion need to be investigated.

Prepubertal growth and growth hormone secretion in children after treatment for hematological malignancies, including autologous bone marrow transplantation.

Prepubertal growth standards were used to assess growth in 20 children who had undergone autologous bone marrow transplantation (ABMT) as part of their treatment for hematological malignancy. Most of the patients (16 of 20) were transplanted after a relapse of their disease. A negative change in height standard deviation score (H-SDS) was seen only in the group of patients (n = 7) who had received both cranial irradiation therapy (CRT) and 7.5-Gy single-fraction total body irradiation (TBI). Height changes in this group were observed from the time of diagnosis. In contrast, the groups of patients conditioned with chemotherapy only (n = 3) or both chemotherapy and TBI, without preceding CRT (n = 10), did not demonstrate a significant loss in H-SDS. Weight related to height demonstrated large individual differences over time. Spontaneous growth hormone (GH) secretion, as measured by a four-point sleep curve, was followed longitudinally and an increasing proportion of patients with low peak levels was seen in all patient groups. In summary, prepubertal growth was suppressed only in patients who received cranial irradiation before ABMT. Despite low GH peak levels, normal prepubertal growth was found in patients with no CRT before ABMT.

Regional cerebral blood flow and neuron-specific enolase in cerebrospinal fluid in children with acute lymphoblastic leukemia during induction treatment.

PURPOSE: To investigate possible side effects on the central nervous system from intrathecal methotrexate given during induction treatment for acute lymphoblastic leukemia in childhood. PATIENTS AND METHODS: Twenty-five children with acute lymphoblastic leukemia were examined by cerebral single photon emission computed tomography at the beginning of treatment (16 untreated, 9 during the first week) and after 4 weeks of treatment. Cerebrospinal fluid was sampled for analyses of neuron-specific enolase on four occasions in 54 patients. RESULTS: Regional cerebral blood flow became impaired during treatment in all patients. The single photon emission computed tomography score for nonhomogeneous perfusion increased from 6.4/50 to 16.6/50. Hypoperfusion was global without any clear preference for any lobe. The cerebellum was not affected. Neuron-specific enolase increased significantly during treatment, with a peak after 1 week, followed by a gradual decrease, but it was still significantly elevated after 4 weeks. CONCLUSIONS: Nonhomogeneous cerebral hypoperfusion was found in all patients during induction treatment, including repeated intrathecal administration of methotrexate, but before systemic high-dose methotrexate. Signs of neuronal injury, in the form of a moderate increase in neuron-specific enolase in the cerebrospinal fluid, were found early in the treatment. Follow-up is needed to evaluate the long-term impact of these findings.

Increased incidence rates but no space-time clustering of childhood astrocytoma in Sweden, 1973-1992: a population-based study of pediatric brain tumors.

BACKGROUND: Incidence patterns, trends, and spatial and/or temporal clustering of childhood brain tumors were analyzed in the population-based national cancer registry of Sweden. METHODS: Temporal trends were analyzed by a logistic regression procedure in which the average annual percentages of change in incidence rates and the corresponding 95% confidence intervals (CIs) were calculated. Spatial and/or temporal clustering were investigated by using a geographic information system and analyzed with a modified version of the Knox test and a spatial scan statistic. RESULTS: Primary brain tumors in 1223 children ages 0-15 years were registered during 1973-1992. In 80% of cases, the tumor was classified as malignant. Conclusive histopathology was classified in 1142 cases. The age-adjusted incidence rate for all subtypes of brain tumors was 35.9 cases per million children, and for malignant brain tumors 28.6. A statistically significant increasing temporal trend was observed for the group of malignant brain tumors as a whole (P=0.0001) and the astrocytoma subgroup (P=0.0001). The annual average increases were 2.6% (95% CI=1.5-3.8) and 3.0%, respectively (95% CI=1.6-4.4). The increase in astrocytoma cases was significantly larger for girls than for boys (P=0.021) and was most striking for girls ages 6-15 years, with an annual average increase of 4.7%. Rates had not increased for the primitive neuroectodermal tumor (PNET)/medulloblastoma or ependymoma subgroups. The geographic distribution of astrocytoma cases was homogenous. No statistically significant space-time interaction or local clusters in space and/or time were found for astrocytomas only or when astrocytomas were grouped with PNETs/medulloblastomas and ependymomas. CONCLUSIONS: The results show statistically increased incidence rates of childhood astroglial tumors, predominantly for girls, in Sweden during the period 1973-1992, but no clustering in space or time.

Increased LH and FSH secretion after cranial irradiation in boys.

The effect of high-dose cranial- and craniospinal irradiation and chemotherapy on the gonadotropin-sex steroid axis was studied during different stages of puberty by measuring pulsatile secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone. The patients were thirteen boys who had been treated for malignant brain tumor residing well away from the hypothalamo-pituitary region. The median time to follow-up was 9 (1-16) years. The onset of puberty was early in the patients, median 10.5 years, compared to the average age for Swedish boys, which is at median 12.4 years. There was, before puberty, no significant difference in LH and FSH secretion between patients and a control group of normal boys. In early, mid- and late stages of puberty, however, LH and FSH secretion was increased in the patients overall, whereas testosterone secretion was maintained within the normal range in spite of signs of gonadotoxocity with small testicular volumes. These results indicate that the vulnerable parts of the gonadotropin releasing hormone (GnRH)-gonadotropin (LH, FSH)-gonadal axis are the regulatory system that determines the timing of pubertal induction and the gonads. The GnRH-LH, FSH-releasing neurons appear relatively resistant to cranial irradiation as they are able to respond with supranormal LH and FSH levels for long periods of time after treatment.

Twenty-four-hour profiles of luteinizing hormone, follicle-stimulating hormone, testosterone, and estradiol levels: a semilongitudinal study throughout puberty in healthy boys.

To follow and correlate gonadotropin and sex steroid changes throughout puberty, 24-h profiles of LH, FSH, testosterone, and estradiol were taken on several occasions for between 2-9.5 yr in 12 healthy boys, aged 8.7-18.2 yr. Serum concentrations of LH and FSH were measured every 20 min, whereas testosterone and estradiol were measured every 2-4 h during the 24-h period. The prepubertal boys (Tanner stage 1) were subdivided into two groups: Pre 1, with a testicular volume of 1-2 mL, and Pre 2, with a testicular volume of 3 mL. Pubertal stages were classified, according to testicular volume, as early puberty (pubertal stage 2; 4-9 mL), midpuberty (pubertal stages 3-4; 10-15 mL), and late puberty (pubertal stage 5; > or = 16 mL). Mean levels of LH and FSH increased with pubertal development, although the increase in LH was greater than that in FSH. These increases were due to elevated basal levels of LH and FSH as well as to increases in the number of peaks and the peak amplitudes of LH. No diurnal rhythm was found in boys at stage Pre 1. Thereafter, a clear diurnal rhythm appeared for LH, and later in puberty, an ultradian rhythm was superimposed, as shown by time-sequence analyses. A diurnal rhythm also existed for FSH, but was much less marked than that for LH despite a clear covariation between LH and FSH, as shown from cross-correlation studies. Testosterone also showed diurnal variations from the late prepubertal stage, followed by increasing levels during both day and night in puberty. We conclude that during puberty, gonadotropin levels rise differently for LH and FSH, which may be due to the development of differences in feedback mechanisms. Despite covariation between LH and FSH, only LH showed a clear diurnal variation. In parallel, nocturnal variations in testosterone and estradiol were found. Changes in mean levels of LH, testosterone, and estradiol as well as their mean daytime and nighttime levels follow each other from the prepubertal stages to late puberty.

Studies of cerebral blood flow in children with acute lymphoblastic leukemia: case reports of six children treated with methotrexate examined by single photon emission computed tomography.

PURPOSE: Cranial irradiation has been widely used in order to prevent central nervous system (CNS) relapse of acute lymphoblastic leukemia (ALL) in childhood. Owing to the risk of late side effects, the Nordic Society for Pediatric Hematology and Oncology (NOPHO) replaced CNS irradiation with systemic high-dose methotrexate (HDMTX) in 1992. A prospective study of the effects of HDMTX and intrathecal MTX on CNS function is in progress at our center. PATIENTS AND METHODS: Six ALL patients underwent (99m)Tc-HMPAO single-photon emission computed tomography (SPECT) examination of regional cerebral blood flow (rCBF): three owing to neurological symptoms during treatment for ALL and the other three as part of the study. RESULTS: All the patients had various degrees of disturbed rCBF, which was more pronounced in the patients with neurological symptoms. One patient had severe symptoms and impaired rCBF after three intrathecal injections of MTX but before administration of HDMTX. CONCLUSIONS: Impaired cerebral perfusion was found in patients with and without neurological symptoms during treatment for ALL. The impact of these findings is still unknown, from both the long- and the short-term perspective. The possibility that intrathecal MTX alone or in combination with HDMTX may affect rCBF through vascular damage should be further investigated, in terms of both mechanisms and clinical significance.

[Radical or conservative surgery in craniopharyngioma? Importance of individualized treatment!]. / Radikal eller konservativ kirurgi vid kraniofaryngiom? Individualiserad behandling viktig!

In a retrospective study of 36 children aged 3-16 years, undergoing 'radical' surgery for craniopharyngioma, postoperative radiography showed tumour excision to have been complete in 25 cases and partial in 11 cases. The recurrence rate was 40% among those treated with surgery alone (N = 27), whereas there were no recurrences among those given adjunctive radiotherapy (RT) (N = 9). Although surgery in the hypothalamic region carries a high risk of severe lasting sequelae, long-term follow-up (mean duration 15 years) showed no difference in this respect between the RT and non-RT subgroups. Until large, preferably international, prospective studies may resolve the lack of consensus regarding the optimal treatment of craniopharyngioma, the authors advocate a more individualised approach, the choice between different treatment modalities and combinations being based on tumour size, location and structure.

Reduced growth hormone secretion with maintained periodicity following cranial irradiation in children with acute lymphoblastic leukaemia.

OBJECTIVE: Low dose cranial irradiation in children with acute lymphoblastic leukaemia (ALL) has been reported to reduce GH secretion in puberty. A recent study also reported a disturbed periodicity of GH secretion during puberty. We have focused on the different stages of puberty in studying these two parameters of GH secretion and have also compared the effects of 18 vs 24 Gy radiation dose. PATIENTS AND MEASUREMENTS: Thirty-four children previously treated for ALL were compared with a control group of 208 healthy normally growing children. GH secretion was measured as 24-hour profiles. RESULTS: In children treated for ALL, GH secretion rate and GH peak amplitude were below the median values for controls, both before puberty and during all stages of puberty. The difference between patients and controls was most pronounced in late puberty. Radiation with 18 or 24 Gy gave similar results. However, time sequence analysis showed a similar periodicity of GH secretion in both patient and control groups before, as well as during, puberty. Thus, before puberty a broad range of cycles per 24 hours was seen. These synchronized during puberty to a predominant GH peak frequency of one every 3-4 hours. CONCLUSIONS: After low dose cranial irradiation with 18 or 24 Gy, the total amount of GH secreted is reduced both before and during puberty. We could not confirm previous findings of impaired periodicity of GH secretion in these children.

Long-term use of central venous catheters in paediatric oncology treatment.

During a 26-month period, 158 central venous catheters were inserted in 114 children (median age: 4.5 years) with malignant diseases. Polyurethane catheters were used, inserted either using a cut-down procedure or percutaneously in the external or internal jugular vein. All catheters were tunnelled from the point of insertion to the midpoint of the manubrium or upper sternum. The catheter tip reached the superior caval vein or the right atrium in 94% of the cases. The catheters were used for all infusions, including total parenteral nutrition, and for blood sampling. The median catheter duration was 104 days (range 5-835 days). Sixty-eight (43%) of the catheters were removed as they were no longer needed, and 31 (20%) were removed due to local infection or septicaemia. During a total of 23,486 catheter days (64.4 years), 110 episodes of septicaemia occurred. This represents one episode per 214 catheter days. In 43 of the 110 episodes of septicaemia, blood cultures showed growth of bacteria of the kind usually found in the gastrointestinal and respiratory tracts. All septicaemias were treated with intravenous broad-spectrum antibiotics and in 21 cases the catheters were removed due to septicaemia. Thirty-four (22%) catheters were removed accidentally. There were two cases of subclavian vein thrombosis.

A longitudinal study of growth and growth hormone secretion in children during treatment for acute lymphoblastic leukemia.

Diminished growth rate during treatment for acute lymphoblastic leukemia (ALL) is of the multifactorial etiology. Effects on GH secretion have been shown after discontinuation of treatment including prophylactic CNS irradiation. Seventeen children treated for ALL with three different CNS preventive schedules were followed longitudinally with repeated estimations of the spontaneous GH secretion during a 24-month period. No difference was found in GH secretion during this time between patients who had received no radiotherapy and those who had received 18 or 24 Gy as CNS prophylaxis. During dexamethasone treatment the GH secretion was completely suppressed, which can be a mediator for the diminished growth rate during the first 2 years of ALL treatment. We conclude that there is no clinical reason to perform GH analysis within the first 24 months of treatment for ALL.