Neurodevelopmental outcome in children with congenital cytomegalovirus infection: A prospective multicenter cohort study.

BACKGROUND: Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic. AIM: This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV. METHODS: All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed. RESULTS: Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss. CONCLUSION: Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.

Non-primary CMV infection not always innocent. A case-report and literature review.

OBJECTIVES: Cytomegalovirus (CMV) is the most common infectious cause of congenital malformations. CMV infections are frequently symptomatic in case of a primary infection during pregnancy. Generally, maternal immunity protects the newborn against a symptomatic course of the CMV infection. METHODS: We present clinical information and medical images of a neonate with non-primary congenital CMV infection. RESULTS: We report the case of a severe congenital infection in a newborn clinically presenting with diffuse petechia, facial dysmorphisms, respiratory distress, hepatomegaly and hypotonia. The girl was born to a mother with CMV immunity. Blood results demonstrated thrombocytopenia and elevated transaminases. Brain MRI revealed ventricular dilatation and germinolytic cysts, compatible with CMV infection. Auditory brain stem response testing was abnormal. CMV culture of saliva was positive. This led to the diagnosis of a severe congenital CMV infection due to a non-primary maternal infection. Antiviral treatment with valganciclovir was initiated immediately and continued for 6 months. CONCLUSION: Our case illustrates that, even when the mother was demonstrated CMV immune, congenital CMV infection is still an important differential diagnostic consideration in neonates presenting with congenital cerebral abnormalities, thrombocytopenia and/or hearing loss. ABBREVIATIONS: ABR: auditory brainstem responses; CMV: Cytomegalovirus; CPAP: Continuous Positive Airway Pressure; CRP: C-Reactive Protein; dBnHL: Decibel Above Normal Adult Hearing Level; IV: intravenously; MRI: Magnetic Resonance Imaging; SGA: Small for Gestational Age; SNHL: Sensorineural Hearing Loss.

Characterization of genetic diversity of Bacillus anthracis in France by using high-resolution melting assays and multilocus variable-number tandem-repeat analysis.

Using high-resolution melting (HRM) analysis, we developed a cost-effective method to genotype a set of 13 phylogenetically informative single-nucleotide polymorphisms (SNPs) within the genome of Bacillus anthracis. SNP discrimination assays were performed in monoplex or duplex and applied to 100 B. anthracis isolates collected in France from 1953 to 2009 and a few reference strains. HRM provided a reliable and cheap alternative to subtype B. anthracis into one of the 12 major sublineages or subgroups. All strains could be correctly positioned on the canonical SNP (canSNP) phylogenetic tree, except the divergent Pasteur vaccine strain ATCC 4229. We detected the cooccurrence of three canSNP subgroups in France. The dominant B.Br.CNEVA sublineage was found to be prevalent in the Alps, the Pyrenees, the Auvergne region, and the Saône-et-Loire department. Strains affiliated with the A.Br.008/009 subgroup were observed throughout most of the country. The minor A.Br.001/002 subgroup was restricted to northeastern France. Multiple-locus variable-number tandem-repeat analysis using 24 markers further resolved French strains into 60 unique profiles and identified some regional patterns. Diversity found within the A.Br.008/009 and B.Br.CNEVA subgroups suggests that these represent old, ecologically established clades in France. Phylogenetic relationships with strains from other parts of the world are discussed.

Reorganization of inhibitory synapses and increased PSD length of perforated excitatory synapses in hippocampal area CA1 of dystrophin-deficient mdx mice.

Dystrophin is a cytoskeletal membrane-bound protein expressed in both muscle and brain. Brain dystrophin is thought to be involved in the stabilization of gamma-aminobutyric acid (GABA)(A)-receptor (GABA(A)-R)clusters in postsynaptic densities (PSDs) at inhibitory synapses onto pyramidal cells, and its loss has been linked to cognitive impairments in Duchenne muscular dystrophy. Dystrophin-deficient mdx mice have learning deficits and altered synaptic plasticity in cornu ammonis (CA1) hippocampus, but the possibility that altered synapse morphology or distribution may underlie these alterations has not been examined. Here we used in vivo magnetic resonance imaging and histological analyses to assess brain volumetric and cytoarchitectonic abnormalities and quantitative electron microscopy to evaluate the density and ultrastructure of CA1 hippocampal synapses in mdx mice. We found that mdx mice have increased density of axodendritic symmetric inhibitory synapses and larger PSDs in perforated asymmetric excitatory synapses in the proximal, but not distal, CA1 apical dendrites that normally express dystrophin, in the absence of gross brain malformations. Data are discussed in light of the known molecular and neurophysiological alterations in mdx mice. We suggest that increased inhibitory synapse density reflects tenuous compensation of altered clustering of alpha2 subunit-containing GABA(A)-Rs in CA1 dendrites, whereas increased PSD length in perforated synapses suggests secondary alterations in excitatory synapse organization associated with enhanced synaptic excitation.

Transsynaptic expression of a presynaptic glutamate receptor during hippocampal long-term potentiation.

Repetitive activation of excitatory synapses in the hippocampus produces a persistent enhancement of synaptic efficiency known as long-term potentiation (LTP). In anesthetized and in freely moving rats, the induction of LTP in the perforant path led to a transient increase in the amount of messenger RNA (mRNA) coding for a presynaptic glutamate receptor (GR33) in dentate granule cells. The amount of GR33 mRNA was increased for at least 5 hours after the induction of LTP but was indistinguishable from control values 1 day after induction. The N-methyl-D-aspartate receptor antagonist 2-aminophosphonovalerate prevented the induction of both LTP and the increase in GR33 mRNA. The amount of GR33 protein was increased in the mossy fiber terminal zone of dentate granule cells 5 hours after the induction of LTP. These results suggest that the induction of LTP in synapses at one stage in a neural network may lead to modification in synaptic function at the next stage in the network.

Psychopathology among preterm infants using the Diagnostic Classification Zero to Three.

AIM: To compare the prevalence of psychopathology in infants born preterm with matched full-term infants at the corrected age of 1 year. METHODS: Between June 2003 and April 2005, a case-control longitudinal cohort study was conducted at the neonatal unit of the University Hospital of Antwerp, Belgium. We prospectively enrolled 123 live-born infants between 25 and 35 weeks of gestation and/or infants with a birth-weight of <1500 g. Thirty full-term infants were recruited among day care centres in the region. Diagnoses were based on the Diagnostic Classification Zero to Three (DC: 0-3), using the MacArthur Communicative Developmental Inventory Dutch version, Infant-Toddler Sensory Profile, Bayley Scales of Infant Development II, Parent Infant Relationship Global Assessment Scale and Functional Emotional Assessment Scale. RESULTS: At the (corrected) age of 12 months, 89 infants were eligible for follow-up and complete data were available for 69 (77%) infants. Fifty-four percentage of the preterm infants fulfilled one or more DC 0-3 diagnoses. Premature infants had significantly more diagnoses than full-term infants on axis I, axis III and axis V of the DC: 0-3. CONCLUSION: In this study, the prevalence of psychopathology was significantly higher among preterm infants in comparison with full-term infants. This study did not confirm previous findings of higher rates of relationship disorders among preterm infants.

Spatial and temporal changes in signal transduction pathways during LTP.

Following LTP induction in freely moving rats, in situ hybridization revealed discrete changes in the expression of one isoform in each of four families of serine/threonine kinases constitutively expressed in the dentate gyrus of the hippocampus. Expression of the alpha isoform of CaMKII showed a transient increase over the soma and a more persistent increase over the dendritic field of dentate granule cells. Of the PKC isoforms, only gamma PKC was up-regulated substantially 2 hr after LTP induction, declining to control levels 48 hr later. An increase in the expression of mRNA for ERK2 and raf-B was seen at 24 hr only. These results show that, during the maintenance phase of LTP in the hippocampus, there are selective increases in the expression of serine/threonine kinases and that these increases have specific and characteristic temporal and spatial profiles.

Erwinia amylovora type three-secreted proteins trigger cell death and defense responses in Arabidopsis thaliana.

Erwinia amylovora is the bacterium responsible for fire blight, a necrotic disease affecting plants of the rosaceous family. E. amylovora pathogenicity requires a functional type three secretion system (T3SS). We show here that E. amylovora triggers a T3SS-dependent cell death on Arabidopsis thaliana. The plants respond by inducing T3SS-dependent defense responses, including salicylic acid (SA)-independent callose deposition, activation of the SA defense pathway, reactive oxygen species (ROS) accumulation, and part of the jasmonic acid/ethylene defense pathway. Several of these reactions are similar to what is observed in host plants. We show that the cell death triggered by E. amylovora on A. thaliana could not be simply explained by the recognition of AvrRpt2 ea by the resistance gene product RPS2. We then analyzed the role of type three-secreted proteins (T3SPs) DspA/E, HrpN, and HrpW in the induction of cell death and defense reactions in A. thaliana following infection with the corresponding E. amylovora mutant strains. HrpN and DspA/E were found to play an important role in the induction of cell death, activation of defense pathways, and ROS accumulation. None of the T3SPs tested played a major role in the induction of SA-independent callose deposition. The relative importance of T3SPs in A. thaliana is correlated with their relative importance in the disease process on host plants, indicating that A. thaliana can be used as a model to study their role.

A requirement for the immediate early gene Zif268 in the expression of late LTP and long-term memories.

The induction of long-term potentiation (LTP) in the dentate gyrus of the hippocampus is associated with a rapid and robust transcription of the immediate early gene Zif268. We used a mutant mouse with a targeted disruption of Zif268 to ask whether this gene, which encodes a zinc finger transcription factor, is required for the maintenance of late LTP and for the expression of long-term memory. We show that whereas mutant mice exhibit early LTP in the dentate gyrus, late LTP is absent when measured 24 and 48 hours after tetanus in the freely moving animal. In both spatial and non-spatial learning tasks, short-term memory remained intact, whereas performance was impaired in tests requiring long-term memory. Thus, Zif268 is essential for the transition from short- to long-term synaptic plasticity and for the expression of long-term memories.

[CSF: diagnosis of neurosyphilis in a patient hospitalized for an acute brain stroke]. / LCR : diagnostic d'une neurosyphilis lors d'une hospitalisation pour un accident vasculaire cérébral.

We report the case of a sixty-eight years old patient, who was admitted to the emergency for paresthesis associated with dysarthra and speech complaints. Neuroimaging revealed the presence of stenosis caused by arteritis. The notion of history of syphilis infection led to diagnosis of neurosyphilis. Diagnosis is difficult due to its clinical polymorphism and requires using several tests in the cerebrospinal fluid (CSF) because infection involving the central nervous system. Neurosyphilis is diagnosed by finding elevated cell count (80 leukocytes/mm3), high protein level (1.07 g/L) and positive IgG oligoclonal bands. In addition CSF and blood should be titrated with the VDRL and TPHA tests which are difficult to interpret. The diagnosis of active neuro-syphilis requires positive, non specific and specific inflammatory tests.

Beta-amyloid pathology in the entorhinal cortex of rats induces memory deficits: implications for Alzheimer's disease.

Alzheimer's disease is characterized by the presence of senile plaques in the brain, composed mainly of aggregated amyloid-beta peptide (Abeta), which plays a central role in the pathogenesis of Alzheimer's disease and is a potential target for therapeutic intervention. Amyloid plaques occur in an increasing number of brain structures during the progression of the disease, with a heavy load in regions of the temporal cortex in the early phases. Here, we investigated the cognitive deficits specifically associated with amyloid pathology in the entorhinal cortex. The amyloid peptide Abeta(1-42) was injected bilaterally into the entorhinal cortex of rats and behavioral performance was assessed between 10 and 17 days after injection. We found that parameters of motor behavior in an open-field as well as spatial working memory tested in an alternation task were normal. In contrast, compared with naive rats or control rats injected with saline, rats injected with Abeta(1-42) showed impaired recognition memory in an object recognition task and delayed acquisition in a spatial reference memory task in a water-maze, despite improved performance with training in this task and normal spatial memory in a probe test given 24 h after training. This profile of behavioral deficits after injection of Abeta(1-42) into the entorhinal cortex was similar to that observed in another group of rats injected with the excitotoxic drug, N-methyl-d-aspartate. Immunohistochemical analysis after behavioral testing revealed that Abeta(1-42) injection induced a reactive astroglial response and plaque-like deposits in the entorhinal cortex. These results show that experimentally-induced amyloid pathology in the entorhinal cortex induces selective cognitive deficits, resembling those observed in early phases of Alzheimer's disease. Therefore, injection of protofibrillar-fibrillar Abeta(1-42) into the entorhinal cortex constitutes a promising animal model for investigating selective aspects of Alzheimer's disease and for screening drug candidates designed against Abeta pathology.

Maturation of cerebral electrical activity and development of cortical folding in young very preterm infants.

OBJECTIVE: The aim of this study was to examine the relationship between cortical development and cerebral electrical activity at early gestational ages. METHODS: We obtained EEGs (7.2+/-3.8 days) and MR brain images (3.2+/-2.9 days) after birth in 17<30 week gestation infants without evidence of focal brain injury The EEGs were assessed for discontinuity and characteristic maturational features (delta brush, occipital and temporal sawtooth); cortical development was quantified from MR scans using a specially designed computer programme to measure cortical folding. RESULTS: The inter-burst interval shortened and cortical folding increased with increasing post-menstrual age (PMA). In contrast, the minimum duration of bursts was independent of PMA and cortical folding. Delta brush (8-20 Hz activities) was seen at all PMAs; temporal and occipital sawtooth activities were always more prominent than delta brush but were seen less frequently with increasing PMA and complexity of cortical folding. CONCLUSION: There was a positive correlation between some but not all maturational features of the preterm neonatal EEG and the complexity of whole brain cortical folding and PMA. These relationships were strong for the inter-burst interval, a global measure of maturation, but not strongly seen for regional features such as occipital and temporal sawtooth within this gestational age range. SIGNIFICANCE: Combining neurophysiological examination with detailed neuroimaging gives insights into developmental changes occurring in the very preterm brains and suggests further comparative studies focusing on measures of focal brain development at different gestational ages.

Generation of aggregated beta-amyloid in the rat hippocampus impairs synaptic transmission and plasticity and causes memory deficits.

We injected a combination of the beta-amyloids (Abetas) Abeta40 and Abeta43 to "seed" formation of amyloid deposits in the dorsal dentate gyrus of rats in vivo, on the basis of a theory of Jarrett and Landsbury (1993). Rats were tested on several different learning tasks, and synaptic transmission and plasticity were assessed in vivo. Between 7 and 16 weeks after injection, we found aggregated amyloid material, reactive astrocytosis, microgliosis, and cell loss around the sites of injection. Rats were impaired specifically in working memory type tasks in accordance with the type of memory deficit observed in the early stages of Alzheimer's disease. Synaptic transmission and long-term potentiation, a candidate cellular mechanism for memory, were severely impaired in vivo. Injections of the same dose of fragments individually did not induce these effects. These findings suggest that aggregated amyloid material induces cognitive deficits similar to those observed in the early phases of Alzheimer's disease via an alteration in neuronal transmission and plasticity.

Gene control of synaptic plasticity and memory formation: implications for diseases and therapeutic strategies.

There has been nearly a century of interest in the idea that information is stored in the brain as changes in the efficacy of synaptic connections between neurons that are activated during learning. The discovery and detailed report of the phenomenon generally known as long-term potentiation opened a new chapter in the study of synaptic plasticity in the vertebrate brain, and this form of synaptic plasticity has now become the dominant model in the search for the cellular and molecular bases of learning and memory. Accumulating evidence suggests that the rapid activation of the genetic machinery is a key mechanism underlying the enduring modification of neural networks required for the laying down of memory. Here we briefly review these mechanisms and illustrate with a few examples of animal models of neurological disorders how new knowledge about these mechanisms can provide valuable insights into identifying the mechanisms that go awry when memory is deficient, and how, in turn, characterisation of the dysfunctional mechanisms offers prospects to design and evaluate molecular and biobehavioural strategies for therapeutic prevention and rescue.

Inter-rater agreement on identification of electrographic seizures and periodic discharges in ICU EEG recordings.

OBJECTIVE: This study investigated inter-rater agreement (IRA) among EEG experts for the identification of electrographic seizures and periodic discharges (PDs) in continuous ICU EEG recordings. METHODS: Eight board-certified EEG experts independently identified seizures and PDs in thirty 1-h EEG segments which were selected from ICU EEG recordings collected from three medical centers. IRA was compared between seizure and PD identifications, as well as among rater groups that have passed an ICU EEG Certification Test, developed by the Critical Care EEG Monitoring Research Consortium (CCEMRC). RESULTS: Both kappa and event-based IRA statistics showed higher mean values in identification of seizures compared to PDs (k=0.58 vs. 0.38; p<0.001). The group of rater pairs who had both passed the ICU EEG Certification Test had a significantly higher mean IRA in comparison to rater pairs in which neither had passed the test. CONCLUSIONS: IRA among experts is significantly higher for identification of electrographic seizures compared to PDs. Additional instruction, such as the training module and certification test developed by the CCEMRC, could enhance this IRA. SIGNIFICANCE: This study demonstrates more disagreement in the labeling of PDs in comparison to seizures. This may be improved by education about standard EEG nomenclature.

Long-term Activation of Phosphoinositide Turnover Associated with Increased Release of Amino Acids in the Dentate Gyrus and Hippocampus Following Classical Conditioning in the Rat.

The release of amino acids and the hydrolysis of inositol phospholipids were examined in parallel in three hippocampal areas following classical conditioning. Paired or unpaired tone(CS) - shock(US) presentations were given to animals engaged in a previously acquired food-motivated lever-pressing task. Conditioned suppression of lever-pressing was the behavioural measure of conditioning. Twenty-four hours after the last conditioning session, the dentate gyrus and areas CA3 and CA1 of the hippocampus were removed bilaterally from conditioned and pseudoconditioned animals, and slices cut and stored in liquid nitrogen for subsequent analysis. Crude synaptosomal pellets were prepared to investigate: (i) potassium-stimulated release of preloaded [3H]glutamate and [14C]aspartate in the presence and absence of extracellular Ca2+; (ii) [3H]inositol labelling of phosphoinositides and inositol phosphates; and (iii) [14C]arachidonic acid labelling of 1,2-diacylglycerol (1,2-DG). Potassium-stimulated, Ca2+-dependent release of [3H]glutamate in synaptosomes prepared from the dentate gyrus and area CA3 was significantly greater in conditioned animals than in pseudoconditioned animals. In area CA1, K+-stimulated, Ca2+-dependent release of [14C]aspartate was significantly increased in conditioned animals. These results confirm in synaptosomes, and extend to a period of 24 h our previous report of an increased release of transmitter in the dentate gyrus and hippocampus associated with classical conditioning. In parallel with the increased release of amino acids, learning was associated with a significant increase in labelling of phosphoinositides and inositol phosphates by [3H]inositol and a significant increase in labelling of 1,2-DG by [14C]arachidonic acid in the three hippocampal areas examined. It is suggested that a long-lasting presynaptic activation of inositol lipid metabolism may contribute to the learning-dependent increase in the capacity of hippocampal terminals to release transmitter and hence to the maintenance of a neurochemical trace which may, at least in part, underlie lasting changes in synaptic function built up during associative learning.

Long-term potentiation of hippocampal afferents and efferents to prefrontal cortex: implications for associative learning.

It has been proposed that the physical substrate of memory resides in alterations of the strengths or weights of modifiable synaptic connections. In recent years, the hypothesis that the mechanisms underlying a particular form of synaptic plasticity, known as long-term potentiation, or LTP, are activated during learning and may actually subserve the formation of associative memories, has gained much empirical support. This paper reviews experimental studies suggesting that changes in synapse physiology and chemistry are involved in the formation of neural associative representation in hippocampal networks during classical conditioning. Recent experiments investigating LTP and learning-induced synaptic changes at hippocampal outputs to the prefrontal cortex are reported. The results provide a working framework within which the dynamics of information storage in hippocampal and prefrontal cortical networks is profiled.

Activation of metabotropic glutamate receptors induce differential effects on synaptic transmission in the dentate gyrus and CA1 of the hippocampus in the anaesthetized rat.

Activation of ACPD-sensitive metabotropic receptors induced differential effects on synaptic transmission and the induction of LTP in CA1 and the dentate gyrus of the hippocampus i.c.v. injections of (1.S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid [(1S,3R)-ACPD] induced enduring potentiation of the fEPSP in CA1, which occluded tetanically induced LTP. In contrast, ACPD induced a dose-dependent biphasic effect on the fEPSP in the dentate gyrus, consisting of an initial short lasting potentiation, followed by enduring depression of the response, and blockade of LTP. These two effects are likely to be mediated by two different classes of the receptor as in the dentate gyrus the selective class I agonist, (RS)-3,5-dihydroxyphenylglycine (DHPG) induced sustained potentiation of the fEPSP, whereas the mixed mGluR2 agonist-mGluR1 antagonist, (S)-4-carboxy-3-hydrophenylglycine((S)-4C3H-PG) induced only depression. Increasing the concentration of calcium directly in the dentate gyrus prior to, and in conjunction with, injections of ACPD induced sustained potentiation rather than depression. The differential effects indicate that the second messenger cascades the subtypes of receptors are linked with, mediate different forms of synaptic plasticity within the hippocampus and have important implications for their role in learning.

Linear relation between the magnitude of long-term potentiation in the dentate gyrus and associative learning in the rat. A demonstration using commissural inhibition and local infusion of an N-methyl-D-aspartate receptor antagonist.

Field potentials were recorded in the dentate gyrus of freely-moving rats in a classical conditioning paradigm in which high-frequency stimulation of the perforant path served as a conditioned stimulus. Paired or unpaired perforant path stimulus-footshock presentations were given to animals engaged in a previously acquired food-motivated lever-pressing task. Conditioned suppression of lever-pressing was the behavioural measure of conditioning. Perforant path stimulus trains at an intensity above spike threshold induced long-term potentiation of synaptic transmission in the dentate gyrus. In this condition, animals learned the perforant path stimulus-shock association. Three strategies were employed to block the induction or reduce the magnitude of long-term potentiation induced by the conditioned stimulus: (1) reduction of the intensity of the stimulus below the spike threshold resulted in no long-term potentiation and a failure by the animals to learn the perforant path stimulus-shock association; (2) inhibitory modulation of long-term potentiation by high-frequency activation of commissural input to the dentate gyrus resulted in learning deficits; (3) chronic infusion of DL-2-amino-5-phosphonovalerate, a selective antagonist of the N-methyl-D-aspartate subtype of glutamate receptor, blocked the induction of long-term potentiation and prevented associative learning. A highly significant linear relation emerged from a correlational analysis between the magnitude of the change in synaptic efficacy at the activated synapses and the amount the animals learned about the perforant path stimulus-shock association. The results presented in this paper are consistent with the hypothesis that associative learning depends on the development of lasting changes in synaptic function. We propose that the activation of N-methyl-D-aspartate receptors in the dentate gyrus is involved in this process and that the more change in synaptic efficacy is produced in the activated network, the more the animals learn.