GATA factors in human neuroblastoma: distinctive expression patterns in clinical subtypes.

BACKGROUND: The aim of this study is to elucidate the expression patterns of GATA transcription factors in neuroblastoma and the developing sympathetic nervous system (SNS). METHODS: GATA-2, -3 and -4 and their cofactor friend-of-GATA (FOG)-2 were investigated in primary neuroblastoma by immunohistochemistry, real-time RT-PCR (n=73) and microarray analysis (n=251). In addition, GATA-2, -3 and FOG-2 expression was determined by northern-blot hybridisation. In the developing murine SNS, Gata-4 and Fog-2 were examined by immunohistochemistry. RESULTS: Although Gata-2, -3 and Fog-2 are expressed in the developing nervous system, Gata-4 was not detected. In contrast, protein expression of all factors was observed in human neuroblastoma. Northern-blot hybridisation and real-time RT-PCR suggested specific expression patterns of the four genes in primary neuroblastoma, but did not show unequivocal results. In the large cohort examined by microarrays, a significant association of GATA-2, -3 and FOG-2 expression with low-risk features was observed, whereas GATA-4 mRNA levels correlated with MYCN-amplification. CONCLUSION: The transcription factors GATA-2 and -3, which are essential for normal SNS development, and their cofactor FOG-2 are downregulated in aggressive but not in favourable neuroblastoma. In contrast, upregulation of GATA-4 appears to be a common feature of this malignancy and might contribute to neuroblastoma pathogenesis.

[Bipolar disorder in children and adolescents]. / Le trouble bipolaire infanto-juvénile.

Bipolar disorder affects all age categories, included children and adolescents (in this case, prepubertal and early adolescent or PEA-BP). Its diagnosis at this age is difficult for two reasons: first, clinical symptoms are different from these encountered by adults and second, an important psychiatric comorbidity is often observed (especially with attention-deficit/hyperactivity disorder or ADHD). This review presents the clinical presentation, the differential diagnosis, the familial antecedents, the comorbidity and the treatment of the PEA-BP.

Living donor kidney transplantation: impact of differentiated immunosuppressive regimen.

INTRODUCTION: Recipients of related (R) and unrelated (NR) living donor kidney transplantations (LDKTX) receive immunosuppressive (IS) therapy 5 days in advance in order to achieve low rates of acute rejection episodes. We herein report the different IS regimens for R and NR transplants as well as acute rejection and primary function rates. METHODS: Ninety-five LDKTX (69% R, 31% NR) were performed with mean cold ischemia time (CIT) of 145 +/- 32 minutes. In R-LDKTX mean age of recipients was 31 +/- 12.5 years. This cohort included 41 men and 25 women whose mean age was 50 +/- 11.1 years. The therapeutic regimen for R-LDKTX included CyA/MMF/prednisone; for NR-LDKTX, FK/MMF/prednisone. Among the recipients of NR grafts the mean recipient age was 51 +/- 8.5 years. This cohort included 23 men and 6 women whose donor mean age was 50 +/- 8.8 years. The mean HLA mismatch among R-LDKTX (2.3) was significantly less than that in the NR-LDKTX cohort (3.51). RESULTS: At a mean follow-up of 35 months, 94.7% of grafts were functioning. DGF was seen in only one recipient (1%). Three grafts were lost due to acute (R) or chronic (NR) rejection or to multiorgan failures. Two recipients died with functioning grafts. Biopsy-proven rejection episodes were observed in 17.2% of NR-LDKTX and 9% of R-LDKTX. In R-LDKTX 50% of rejection episodes were corticoid-sensitive, while 33% needed ATG, and 16% were treated by a switch to FK. In NR-LDKTX 20% of rejections were corticoid-sensitive, 40% needed ATG, and 40% were treated with rapamycin rescue therapy. CONCLUSION: Although HLA mismatching is significantly different between R- and NR-LDKTX, no difference in outcome was observed, which may be due to the specific therapeutic regimen and short CIT.

Yunis-Varon syndrome: evidence for a lysosomal storage disease.

We present clinical and neuropathological findings in a female infant with Yunis-Varon syndrome (YVS) comprising absence of thumbs and halluces, aphalangia of fingers and toes, hypoplasia of clavicles, severely undermineralized skeleton (especially skull), microcephaly, and multiple nonskeletal anomalies. The patient also had a Dandy-Walker malformation, hydrocephalus, and hypertension, which were not reported previously in YVS. The infant excreted an abnormal unidentified oligosaccharide. The patient died at day 108 with severe neurological impairment. Autopsy showed prominent intraneuronal inclusions with vacuolar degeneration, mainly in the thalamic, dentate nuclei, cerebellar cortex, and inferior olivary nuclei. No storage phenomena were observed in other tissues. These findings strongly suggest that a lysosomal storage disorder is involved in the pathogenesis of Yunis-Varon syndrome.

Potentiation of vagal contractile response by thromboxane mimetic U-46619.

We studied the effect of the thromboxane mimetic U-46619 on tracheal smooth muscle contraction caused by bilateral stimulation of the vagus nerves in 14 mongrel dogs in situ. The parasympathetic contractile response was studied isometrically after beta-adrenergic blockade with 2 mg/kg iv propranolol plus 20 micrograms X kg-1 X min-1 continuous intravenous infusion and blockade of endogenous prostaglandin synthesis with 5 mg/kg iv indomethacin. An initial frequency-response curve was generated by electrical stimulation of the caudal ends of cut cervical vagi over the range of frequencies 2-25 Hz (constant 25 V) at 15-s intervals. In five dogs, 10(-10) to 10(-8) mol of the thromboxane mimetic (15S)-hydroxyl-11 alpha,9 alpha-(epoxymethano)prosta-5Z,13E-dienoic acid (U-46619) was injected selectively into the tracheal arterial circulation, causing a transient contractile response (less than or equal to 10 g/cm). Additional frequency response studies were generated 7 min before and 1, 15, 30, 45, and 60 min after U-46619. Substantial augmentation of tracheal contraction to efferent vagal stimulation was observed after U-46619 for all frequencies greater than 4 Hz (P less than 0.02). Augmentation of vagally mediated contraction was not observed in four other dogs after equivalent tracheal contraction was elicited without U-46619. Similarly, in four separate dogs, augmentation of tracheal contraction was not observed when acetylcholine was given instead of vagal stimulation after U-46619. We conclude that the thromboxane analogue, U-46619, causes augmentation of tracheal contractile response induced by efferent vagus nerve stimulation. Potentiation is caused by a prejunctional action of U-46619 and is not induced by nonspecific precontraction with another agonist.

Erythropoietin gene expression in different areas of the developing human central nervous system.

UNLABELLED: Evidence from cell culture and animal experiments suggests a neuroprotective and neurotrophic function of erythropoietin (EPO). We have quantitated the distribution of EPO mRNA expression in the developing human central nervous system (CNS). PATIENTS AND METHODS: Up to seven biopsies from different areas of the CNS of four preterm fetuses (gestational age 23-37 weeks) were obtained at routine postmortem examinations. EPO mRNA was quantitated by competitive PCR in samples from the CNS, the kidneys, and the liver where the EPO gene is predominantly expressed at this gestational age. RESULTS: EPO mRNA was most abundant in one sample from the cerebellum (0.29 amol/microg total RNA [amol=10(-18)mol]) and two from the pituitary gland (0.23 amol/microg total RNA), but levels varied considerably. EPO mRNA in the cortex cerebri (median 0.12 amol/microg total RNA; n=4) dominated over the expression in the corpora amygdala (median 0.05 amol/microg total RNA; n=4), the hippocampus (median 0.03 amol/microg total RNA; n=4), or the basal ganglia (median 0.01 amol/microg total RNA; n=3). Only little EPO mRNA (<0.01 and 0.06 amol/microg total RNA) was found in the spinal cord. EPO mRNA levels in the cerebellum, pituitary gland, or the cerebral cortex were within the same range as in the liver (0.03-1.67 amol/microg total RNA; n=4), or the kidneys (0.06-0.79 amol/microg total RNA; n=4). CONCLUSION: We found the EPO gene expressed throughout the fetal human CNS. Our data provide the basis to discuss a function for EPO in the brain of humans as well.

The switch from fetal to adult erythropoiesis.

The story of the developmental changes in erythropoiesis is the history of oxygenation in the developing organism. The individual components of the switch from embryonic to adult erythropoiesis are developmentally regulated, and their interaction with one another is complex. Basic defects, such as absence of Epo production, lead to early embryonic or fetal death. Other defects, such as abnormalities in the switch from the fetal to adult erythropoiesis, are less catastrophic but result in hematologic abnormalities. Understanding the many aspects of the switch from embryonic to fetal to adult erythropoiesis can lead to an improved awareness of many of the problems typical of preterm infants, inborn errors resulting in hematologic diseases, and aspects important for transplantation medicine.

Cost-effectiveness analysis of basixilimab induction and calcineurin-sparing protocols in "old to old" programs using Markov models.

INTRODUCTION: Markov models are employed in economic analyses to evaluate all possible expectations in a dilemna. The introduction of a new clinical protocol (basiliximab induction with calcineurin-sparing protocols) for a group of kidney transplant recipients receiving organs from marginal donors was validated with a Markov simulation model. HYPOTHESIS: Calcineurin-sparing protocols using anti-IL-2/antibody induction (Simulect) show a beneficial effect on initial kidney function, reducing transplantation costs reception based upon mean length of stay, mean admission cost, and incidences of delayed graft function and complications during the first month after transplant. PATIENTS AND METHODS: A Markov simulation model was established following three different chains. A calcineurin-free regimen with basiliximab induction (chain A), a calcineurin-sparing protocol with basiliximab induction (chain B), and a conventional immunosuppressive regimen (chain C). After designing the Markov chain and cohorts, 31 patients from the "old to old" program were assigned to each chain eight to chain A, (eight to chain B, and 15 to chain C). A month after transplantation a cost-benefit study was performed guided by the three branches of the Markov model. RESULTS: The Markov model showed a benefit of induction therapies in elderly patients. A cost-benefit model showed that after a month there was a clear benefit from Calcineurin=free plus basiliximab induction therapies, with a slight benefit from calcineurin-sparing protocols. CONCLUSIONS: Markov models are extremely useful when introducing new clinical therapies. In our transplant program, a cost-effective analysis of outcomes in old patients using the Markov model showed a clear benefit of calcineurin-sparing protocols with basixilimab induction.

Calcineurin-free protocols with basiliximab induction allow patients included in "old to old" programs achieve standard kidney transplant function.

INTRODUCTION: The EuroTransplant "old to old" program establishes that patients older than 60 years can receive offers of organs from donors older than 60 years. The compromised function of these organs makes it a priority to preserve their initial kidney function. HYPOTHESIS: Calcineurin-sparing protocols using anti-IL-2 receptor (IL-2R) antibody induction (Simulect) may benefit initial kidney function in these patients, as assessed by the rates of delayed graft function and of rejection during the first month after transplant. PATIENTS AND METHODS: A cohort of 15 consecutive elderly patients were prospectively compared with 30 cadaveric kidney transplants in younger recipients. Study patients were induced with Simulect (20 mg, 30 minutes before reperfusion and 4 days after transplantation) and steroids, delaying the introduction of CsA until the serum creatinine was below 3 mg/dL. The other cohort of patients were immunosuppressed with tacrolimus (trough 8 to 12), mycophenolats mofetil (MMF, 1 g/d), and an identical taper of steroids. The analysis compared donor and recipient ages, mean cold ischemic time, incidence of initial kidney function (diuresis in the first 24 h) serum creatinine levels, glomerular filtration rate (GFR), number of dialysis sessions, and rejection rate in the two groups. RESULTS: Except for the donor and recipient ages (72 vs 54 in donors, and 67 versus 52 years in recipients), no significant differences were observed between the groups among the rates of acute rejection (6.6% vs 13.2%), delayed graft function (13.2% required dialysis), or infection (6.6%). Within 1 month all 45 grafts showed primary function with equal creatinine levels (mean 1.65). CONCLUSIONS: Calcineurin-free protocols using IL-2 therapy as the initial suppression allow patients in the "old to old" ET program to display equal results to cadaveric kidney transplants with initial treatment with calcineurin antagonists.

Developmental biology of thrombopoietin in the human fetus and neonate.

UNLABELLED: This review focuses on the biology of thrombopoietin (Tpo) during human development. It summarizes the current understanding on molecular biological aspects of Tpo, cellular effects of Tpo on fetal and neonatal megakaryopoiesis, regulation of Tpo production, and circulating Tpo concentrations in human fetuses and neonates. Some important aspects on the developmental biology of Tpo are highlighted. They include the finding of high Tpo gene expression in the bone marrow during the onset of medullary hematopoiesis, higher circulating Tpo concentrations in fetuses and neonates than in children or adults, and a higher sensitivity of neonatal megakaryocyte progenitor cells to Tpo. However, other aspects of the developmental biology of Tpo are incompletely understood. CONCLUSION: More carefully designed studies are needed to provide the necessary background for an optimal treatment of fetal and neonatal thrombocytopenia.

Low immature platelet fraction suggests decreased megakaryopoiesis in neonates with sepsis or necrotizing enterocolitis.

OBJECTIVE: In order to conclude on the megakaryopoietic activity during thrombocytopenia in sepsis or necrotizing enterocolitis (NEC), we analyzed the immature platelet fraction (IPF). STUDY DESIGN: Serial measurements of platelet counts and IPF in neonates with blood culture-proven late-onset sepsis (n=21) or surgical NEC (n=12) at T0: prior to the diagnosis of sepsis/NEC; T1: at diagnosis; T2: days 3 to 5 after onset; T3: days 8 to 12 after onset. RESULT: In parallel to declining platelet counts, the median absolute IPF significantly decreased between T0 and T2 in neonates with sepsis or NEC. We found a significant positive correlation between the platelet count and absolute IPF (r=0.71; P<0.001). In patients with low IPF (<2 per nl), the platelet count did not subsequently increase. Neonates with NEC who died exhibited significantly lower IPF compared with survivors (P<0.05). CONCLUSION: Low absolute IPF values during the course of neonatal sepsis/NEC suggest suppression of megakaryopoietic activity.

Thrombopoietin in thrombocytopenias of childhood.

This review summarizes the biology of thrombopoietin (TPO) in childhood. Studies on TPO and its receptor (c-mpl) have improved the understanding of inherited and acquired thrombocytopenias in childhood. Data are presented in this review regarding the molecular biology of TPO, differences in cellular effects on megakaryopoiesis, the regulation of TPO production, and TPO concentrations in health and disease. For neonatal thrombocytopenia, the focus is on early-onset thrombocytopenia associated with maternal diabetes, pregnancy-induced hypertension, intrauterine growth retardation, hypoxia, and sepsis. Fetal alloimmune thrombocytopenia allows insight into the biology of TPO when fetal megakaryopoiesis is chronically stimulated. In the thrombocytopenia absent radii syndrome and congenital amegakaryocytic thrombocytopenia, thrombocytopenia is caused by a disorder in the signal transduction at the c-mpl level and respectively directly on c-mpl. TPO concentrations in other inherited thrombocytopenias such as Fanconi anemia, Shwachman syndrome, Wiskott-Aldrich syndrome, and Bernard-Soulier syndrome are discussed. For acquired thrombocytopenias, data on TPO in aplastic anemia, immune thrombocytopenia, human immunodeficiency virus infection, and liver disease are given. Possible indications for a treatment with recombinant TPO in childhood are discussed, but the criteria to identify patients who would benefit need detailed evaluation.

Erythropoietin concentrations and erythropoiesis in newborns suffering from renal agenesis and congenital kidney diseases.

UNLABELLED: We studied serum concentrations of erythropoietin (EPO) in the cord blood of 31 newborns. In patients with renal agenesis (n = 6), the EPO levels were 68.2 (23-177) mU/ml (median, range). These values are clearly above EPO levels in the reference groups (median/range: < 30 weeks 11.0 (5.5-17.5) mU/ml; 30-32 weeks 18.1 (5.5-136) mU/ml; 33-34 weeks 17.7 (8.3-423) mU/ml; 35-37 weeks 17.3 (5.5-272) mU/ml; > or = 38 weeks 17.8 (8.7-40.3) mU/ml). Neonates with polycystic kidney diseases (n = 12, EPO 23.5 (9.7-491) mU/ml) and with severe bilateral hydronephrosis due to obstructive uropathy (n = 13, 18.6 (7.5-30.7) mU/ml) showed no difference to the reference groups. In all groups there were only slight differences in haemoglobin/haematocrit values. CONCLUSION: In spite of renal agenesis and severe congenital kidney diseases, erythropoiesis is sufficiently maintained during fetal life. The liver of congenitally kidney-damaged fetuses is sufficiently able to compensate the reduction in--or lack of--renal EPO production.

The biology of erythropoietin in the central nervous system and its neurotrophic and neuroprotective potential.

This review summarizes published as well as preliminary data on the biology of erythropoietin (Epo) in the developing and mature human central nervous system (CNS). Both Epo receptor (Epo-R) and Epo gene expression underlie developmental changes and a brain-specific regulation. These features suggest a different role of Epo in normal brain development than in neuroprotection and neuronal tissue repair after brain injury. Epo concentrations in the cerebrospinal fluid may have primary paracrine effects. While the transport of Epo across the intact blood brain barrier (BBB) is generally limited in humans, systemically produced or administrated Epo may cross during BBB dysfunction. Summarized data of the in vivo and in vitro effects of Epo in the CNS show significant neuroprotective and neurotrophic effects of this molecule. These effects are mediated by several mechanisms, including the activation of a variety of genes and their consecutive protein production. Therapeutic strategies involving activation of the CNS Epo-R are discussed, including the potential use of Epo mimetic peptides.

Longitudinal data for intrauterine levels of fetal IGF-I and IGF-II.

OBJECTIVE: An increasing body of evidence supports a major role for the insulin-like growth factors (IGFs) in the control of human fetal growth. Individual data at various times of pregnancy suggest that IGF-I and IGF-II levels remain stable up to the 33rd week of pregnancy. Thereafter, both increase to reach values 2-3 times higher at term. In order to provide an accurate reflection of fetal IGFs in utero, we sampled fetal blood from the umbilical cord by cordocentesis. METHODS: We measured IGF-I and IGF-II in 12 fetuses longitudinally for up to 5 times between the 21st week of gestation and delivery. RESULTS: All patients showed a progressive increase in IGF-I and IGF-II levels. Data determined during different time intervals (before 29th, 29th to 32nd, after 32nd week) were compared and the main increase was found after the 32nd week. The median for IGF-I before the 29th week was 33.5 ng/ml (range 19-40.5) and increased to 41 ng/ml (32-59) between the 29th to 32nd and further to 54.1 ng/ml (range 17-70) thereafter. During the same time interval, the median for IGF-II increased from 217 ng/ml (86-326) to 349 ng/ml (227-467). In 7 patients, cord blood after delivery was available. For IGF-II a further increase was consistently found after birth (from 282 ng/ml (175-511) to 393 ng/ml (297-513)), whereas only 2 fetuses showed an increase in IGF-I. CONCLUSION: We conclude that in human fetuses, IGF-I and IGF-II levels increase longitudinally throughout pregnancy. Therefore, they may become important markers of healthy fetal development.