Regina Trollmann

Intravenous valproate in pediatric epilepsy patients with refractory status epilepticus.

Since its first clinical use in France in 1963, valproic acid (VPA) has rapidly established itself worldwide as one of the major antiepileptic drugs, with a broad efficacy for treatment of both generalized and partial seizures in children and adults.1 In October 1996, an IV VPA formulation was approved in Germany for the short-term supplementation of an established oral VPA treatment in patients with epilepsy, when oral-to-parenteral substitution becomes necessary.2 However, IV VPA also offers the opportunity to treat epileptic emergency situations such as prolonged or serial seizures, or even patients with status epilepticus (SE). We report on 41 children with therapy-resistant SE treated with IV VPA. The clinical details of our patients are listed in the table. All children had SE that was refractory to commonly recommended IV antiepileptic drugs (i.e., benzodiazepine compounds, phenytoin, and barbiturates). Whereas 22 of these children received antiepileptic long-term therapy that started before this SE event, SE was the initial presentation of an …

Spontaneous Nocturnal Leptin Secretion in Children with Myelomeningocele and Growth Hormone Deficiency

Objective: To examine the spontaneous leptin secretion in patients with myelomeningocele (MMC) and growth hormone deficiency (GHD). Methods: Serum leptin levels were studied in 10 prepubertal MMC patients with GHD (CA 6.2 ± 0.5 years), 10 patients with idiopathic GHD (IGHD; CA 7.6 ± 0.7 years) and 12 children with normal variant short stature (NVSS; CA 7.6 ± 0.5 years). Mean BMI (kg/m2) values of the groups did not differ significantly. Nocturnal leptin levels were analyzed over 10 h (blood samples every 20 min) and measured by specific radioimmunoassay. Results: Mean leptin concentrations did not correlate with BMI in MMC patients. Nocturnal leptin secretion of MMC patients was significantly different to those of children with IGHD and NVSS. Morning leptin levels did not decline as observed in both other groups. Conclusion: Since all groups were matched for BMI values, we suggest a hypothalamic dysregulation of leptin secretion in MMC patients.

The role of hypoxia-inducible transcription factors in the hypoxic neonatal brain

Hypoxia-inducible transcription factors (HIF)-1 and HIF-2, composed of an oxygen-dependent alpha-subunit and a constitutive beta-subunit, have been characterized as the most important regulators of oxygen homeostasis during physiological and pathological conditions. During embryonic, fetal and postnatal brain development, HIFs and specific HIF target genes are involved in early and highly active maturational processes by modulating cell differentiation, vascular development, angiogenesis and metabolic homeostasis. Under hypoxic conditions, activation of the HIF system reflects an immediate and cell-specific response to acute brain hypoxia. In a complementary fashion, both HIF-1 and HIF-2 modulate cerebral hypoxic stress responses and activate endogenous neuroprotective systems during acute and late stages of hypoxic/ischemic (HI) damage of the developing brain. Therefore, HIFs and their specific target genes that are expressed during brain injury are of particular interest for future diagnostic and therapeutic options in HI injury of the developing nervous system.

PRECOCIOUS PUBERTY IN CHILDREN WITH MYELOMENINGOCELE : TREATMENT WITH GONADOTROPIN-RELEASING HORMONE ANALOGUES

In patients with myelomeningocele (MMC), growth is influenced by a large number of growth‐retarding factors due to the neurological defect. Moreover, endocrine disorders have been found to contribute to short stature in MMC patients. Central precocious puberty (CPP) is a common problem. Due to growth disturbances and difficulties in obtaining standardized measurements, MMC patients have been excluded from gonadotropin‐releasing hormone (GnRH) analogue studies in the past. We report on eight patients (six female, two male) with MMC, hydrocephalus, and CPP who were treated with GnRH analogues: triptorelin intramuscularly (N=5) or leuprorelin subcutaneously (N=3). Auxological data and hormone levels were assessed before treatment and every 6 months during treatment. The median chronological ages (CA) at the start of treatment were 8.6 years (females) and 8.4 years (males). Bone age (BA) was accelerated in all cases prior to treatment and two girls were already menstruating. Elevated gonadotropin serum levels and sex steroid levels decreased during treatment, although no complete suppression to prepubertal levels was reached. Progression of pubertal development and menses stopped in all patients. The tempo of BA acceleration (ΔBA:ΔCA) decreased, but no significant improvement in height standard deviation score BA and predicted adult height resulted. No side effects during treatment were observed. CPP in MMC patients has to be considered as early as possible to enable an early diagnosis and corresponding treatment. Further prospective studies on the effects of GnRH analogues in MMC patients are necessary.

Deficiency of ECHS1 causes mitochondrial encephalopathy with cardiac involvement.

Short‐chain enoyl‐CoA hydratase (ECHS1) is a multifunctional mitochondrial matrix enzyme that is involved in the oxidation of fatty acids and essential amino acids such as valine. Here, we describe the broad phenotypic spectrum and pathobiochemistry of individuals with autosomal‐recessive ECHS1 deficiency.

Oligoclonal bands predict multiple sclerosis in children with optic neuritis

We retrospectively evaluated predictors of conversion to multiple sclerosis (MS) in 357 children with isolated optic neuritis (ON) as a first demyelinating event who had a median follow‐up of 4.0 years. Multiple Cox proportional‐hazards regressions revealed abnormal cranial magnet resonance imaging (cMRI; hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 3.39–10.39, p < 0.001), presence of cerebrospinal fluid immunoglobulin G oligoclonal bands (OCB; HR = 3.69, 95% CI = 2.32–5.86, p < 0.001), and age (HR = 1.08 per year of age, 95% CI = 1.02–1.13, p = 0.003) as independent predictors of conversion, whereas sex and laterality (unilateral vs bilateral) had no influence. Combined cMRI and OCB positivity indicated a 26.84‐fold higher HR for developing MS compared to double negativity (95% CI = 12.26−58.74, p < 0.001). Accordingly, cerebrospinal fluid analysis may supplement cMRI to determine the risk of MS in children with isolated ON. Ann Neurol 2015;77:1076–1082

HIF-1-regulated vasoactive systems are differentially involved in acute hypoxic stress responses of the developing brain of newborn mice and are not affected by levetiracetam.

Hypoxia-inducible transcription factor-1 (HIF-1) is critically involved in adaptive endogenous mechanisms to hypoxic brain injury by transcriptional activation of specific target genes that restore oxygen supply. Exogenously, neuroprotective properties of levetiracetam (LEV) have been suggested in experimental cerebral ischemia and epilepsy. We aimed to elucidate 1) effects of acute hypoxic distress on HIF-1 and vasoactive target genes, and 2) effects of LEV on HIF-1-regulated mechanisms in the brain at early developmental stages. To this end, we studied the impact of hypoxia in the presence or absence of LEV on the O2-dependent HIF-1alpha subunit as well as on VEGF and iNOS in the developing brain of normoxic and hypoxic mice. C57BL/6 mice (P0, P7) were treated with saline or LEV (i.p.; 50 mg/kg) 1 h before exposure to either normoxia (21% O2; N) or hypoxia (8% O2 of 6 h; H) without reoxygenation. HIF-1alpha was analyzed by Western blot and immunohistochemistry and mRNA levels were quantified by TaqMan RT-PCR. Hypoxia led to prominent accumulation of cerebral HIF-1alpha protein in cortical neurons and glial cells and significant up-regulation of VEGF mRNA at P0 (N, 0.018+/-0.002, vs. H, 0.031+/-0.003, n=6; p<0.05) and P7 (N, 0.096+/-0.032, vs. H, 0.873+/-0.069, n=7; p<0.001). Interestingly, we detected a significant decrease of iNOS mRNA levels in hypoxic brains. LEV treatment did not alter HIF-1alpha accumulation either in normoxic or hypoxic brains (P0, P7). Moreover, significant changes of VEGF and NOS mRNA levels did not occur with the exception that hypoxia-induced decreased iNOS levels were not observed in P0 brains. We conclude that acute systemic hypoxia differentially affects expression of HIF-1-regulated vasoactive factors in the newborn mouse brain. Of clinical importance, LEV treatment did not alter crucial HIF-1-regulated neuroprotective mechanisms.

Ratiometric luminescence 2D in vivo imaging and monitoring of mouse skin oxygenation

Tissue oxygenation plays a critical role in the pathogenesis of various diseases, but non-invasive, robust and user-friendly methods for its measurement in vivo still need to be established. Here, we are presenting an in vivo oxygen-detection system that uses ratiometric luminescence imaging (RLI) as a readout scheme to determine the skin oxygen tension of mouse hind footpads via side-by-side comparison with more established techniques including luminescence-lifetime imaging using planar sensor films and the polarographic electrode as the gold standard. We also demonstrate that this technology allows the detection of changes in mouse skin tissue oxygenation induced by subjecting mice to systemic hypoxia. The data demonstrate oxygen imaging based on RLI to be a most useful tool for reliably and easily analyzing and monitoring skin tissue oxygenation in vivo. This technology will advance our understanding of local regulation of skin tissue oxygenation in various disease conditions.

Short-term effects of pharmacologic HIF stabilization on vasoactive and cytotrophic factors in developing mouse brain.

Hypoxia-inducible transcription factors (HIFs) are crucially involved in brain development and cellular adaptation to hypoxia and ischemia. Degradation of HIF is regulated under normoxia by oxygen-dependent hydroxylation of specific prolyl residues on the labile alpha-subunit by HIF prolyl hydroxylases (PHD). Prolyl-4-hydroxylase inhibitors (PHI) have shown protective effects in vitro and in vivo in adult kidney and brain. The aim of the present study was to investigate in vivo short-term effects of a novel low molecular weight PHI, FG-4497, on HIF-regulated cytotrophic and vasoactive factors in developing mouse brain. Neonatal (P7, n=26) C57/BL6 mice were treated with PHI FG-4497 (30-100 mg/kg, i.p., duration 6 h). Gene expression was analyzed by TaqMan RT-PCR in kidney and developing brain in comparison to controls (NaCl 0.9% and non-treated animals). HIF-1alpha protein was quantified by Western blot analysis. Dose-response studies revealed prominent effects of FG-4497 at a dose of 100 mg/kg as assessed by significant up-regulation of mRNA in both kidney and brain of the following HIF-dependent genes: vascular endothelial growth factor, adrenomedullin and erythropoietin. Organ-specific transcriptional regulation was evident from analysis of hexokinase 2, inducible NO synthase and PHD3 mRNA concentrations. In the brain, HIF-1alpha and HIF-2alpha protein markedly accumulated in response to FG-4497. Besides vasoactive factors, PHI significantly increased cerebral chemokine receptor CXCR-4 mRNA levels. In conclusion, the novel PHI FG-4497 activates HIFs at an early stage of brain maturation and modulates neurotrophic processes known to be crucially involved in brain development and hypoxia-induced brain pathology.

Late-gestational systemic hypoxia leads to a similar early gene response in mouse placenta and developing brain

Late-gestational intrauterine hypoxia represents a well-known risk factor of acquired perinatal brain injury. Cell type and age-specific sensitivity of hypoxia-responsive genes to low-oxygen partial pressure is to be considered in the screening for early indicators of fetoplacental tissue hypoxia. To identify early hypoxia-induced alterations in gene expression during late-gestational hypoxia (6% O(2), 6 h; gestational day 20) we compared primary mouse placenta and brain transcriptomes using high-density oligonucleotide microarrays. Upregulation of candidate marker genes for hypoxia was confirmed by quantitative RT-PCR and immunohistochemistry. Both developing brain and placenta were highly responsive to systemic hypoxia at the level of gene expression involving hypoxia-inducible transcription factor (HIF)-dependent genes and immediate early genes (IEG) (Fos, Jun, Egr1, Bhlhb2), apoptosis-promoting factors (Bnip3, Dusp1, Ier3) that were all upregulated, and genes modulating RNA binding and translation (Rbm3, Thap2, Lig4, Rbm12b) that mainly were downregulated. Functional activity of the HIF system was obvious from elevated expression of various known HIF target genes (Adm, Vegf, Hk2, Pdk1, Bnip3, Ier3, Dusp-1), indicating immediate availability among early response to acute hypoxia. In addition, genes not yet described as being hypoxia related were identified that are involved in angiogenesis/cell differentiation (Gna13, Gab2), mRNA processing, and embryonic development. RT-PCR of placenta and brain tissues confirmed upregulation of selected HIF target genes and IEG. These data indicate that the early hypoxia-induced genomic response of the placenta mirrors that of developing brain in a temporally parallel manner. Our observations implicate future diagnostic options to identify fetal and cerebral tissue hypoxia.