Pathological spontaneous activity as a prognostic marker in chronic inflammatory demyelinating polyneuropathy.

BACKGROUND AND PURPOSE: Monitoring of the disease course of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) remains challenging because nerve conduction studies do not adequately correlate with functional disability. The prognostic value of pathological spontaneous activity (PSA) in needle electromyography (EMG) in different CIDP subgroups in a longitudinal context has, to date, not been analysed. We aimed to determine whether PSA was a prognostic marker or a marker of disease activity in a cohort of patients with CIDP. METHODS: A total of 127 patients with CIDP spectrum disorder were retrospectively analysed over 57 ± 47 months regarding the occurrence of PSA (fibrillations and positive sharp waves). The presence of PSA at diagnosis, newly occurring PSA, and continuously present PSA were longitudinally correlated with clinical disability using the Inflammatory Neuropathy Cause and Treatment Overall Disability Sum Score (INCAT-ODSS) and CIDP subtype. RESULTS: Pathological spontaneous activity occurred in 49.6% of all CIDP patients at first diagnosis. More frequent evidence of PSA was significantly associated with a higher INCAT-ODSS at the last follow-up. Continuous and new occurrence of PSA were associated with higher degree of disability at the last follow-up. The majority of patients with sustained evidence of PSA were characterized by an atypical phenotype, higher degree of disability, and the need for escalation of treatment. CONCLUSIONS: Pathological spontaneous activity was associated with a higher degree of disability and occurred more frequently in atypical CIDP variants according to the longitudinal data of a large cohort of patients with CIDP. Our results showed that EMG examination was an adequate marker for disease progression and should be evaluated during the disease course.

Probing the light hole/heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot.

A whole series of complementary studies have been performed on the same single nanowire containing a quantum dot: cathodoluminescence spectroscopy and imaging, micro-photoluminescence spectroscopy under magnetic field and as a function of temperature, and energy-dispersive x-ray spectrometry and imaging. The ZnTe nanowire was deposited on a Si3N4 membrane with Ti/Al patterns. The complete set of data shows that the CdTe quantum dot features the heavy-hole state as a ground state, although the compressive mismatch strain promotes a light-hole ground state as soon as the aspect ratio is larger than unity (elongated dot). A numerical calculation of the whole structure shows that the transition from the heavy-hole to the light-hole configuration is pushed toward values of the aspect ratio much larger than unity by the presence of a (Zn, Mg)Te shell, and that the effect is further enhanced by a small valence band offset between the semiconductors in the dot and around it.

Experimental setup for thermal measurements at the nanoscale using a SThM probe with niobium nitride thermometer.

Scanning Thermal Microscopy (SThM) has become an important measurement technique for characterizing the thermal properties of materials at the nanometer scale. This technique requires a SThM probe that combines an Atomic Force Microscopy (AFM) probe and a very sensitive resistive thermometer; the thermometer being located at the apex of the probe tip allows for the mapping of temperature or thermal properties of nanostructured materials with very high spatial resolution. The high interest of the SThM technique in the field of thermal nanoscience currently suffers from a low temperature sensitivity despite its high spatial resolution. To address this challenge, we developed a high vacuum-based AFM system hosting a highly sensitive niobium nitride (NbN) SThM probe to demonstrate its unique performance. As a proof of concept, we utilized this custom-built system to carry out thermal measurements using the 3ω method. By measuring the V3ω voltage on the NbN resistive thermometer under vacuum conditions, we were able to determine the SThM probe's thermal conductance and thermal time constant. The performance of the probe is demonstrated by performing thermal measurements in-contact with a sapphire sample.

Novel gel-based rapid test for non-instrumental detection of ochratoxin A in beer.

A rapid easy-to-use immunoassay was optimised for the non-instrumental detection of ochratoxin A (OTA) in beer. The analytical method involves preconcentration on the immunoaffinity layer inside a column followed by direct competitive ELISA detection in the same layer. The visual cut-off value, i.e. the lowest OTA concentration resulting in no colour development, was 0.2 microg L(-1). Assay validation was performed using samples spiked with OTA. Thirty-seven naturally contaminated samples were screened with the gel-based method developed and no false-negative results were obtained. The method described offers a simple, rapid and cost-effective screening tool, thus contributing to better health protection of consumers.

[Epidemiological and clinical study of Mycoplasma pneumoniae respiratory infections in children hospitalized in a pediatric ward between 1999 and 2005 at the Reims University Hospital]. / Etude épidémiologique et clinique des infections respiratoires àMycoplasma pneumoniae chez les enfants hospitalisés en pédiatrie entre 1999 et 2005 au CHU de Reims.

OBJECT: To determine the frequency, clinical features, and morbidity of Mycoplasma pneumoniae infections. METHOD: Retrospective study of 76 consecutive children under 16 years of age hospitalized at the Reims University Hospital from 1999 to 2005 with M. pneumoniae pneumonia. The infection was defined by the presence of M antibodies and/or an increase in G antibodies (quantitative Elisa test). RESULTS: M. pneumoniae was the cause of 16% (76/464) of hospitalized pneumonia cases. A significantly increased frequency was observed in 2004 (34%; 19/56) and 2005 (26%; 22/84) versus 11% from 1999 to 2003, p<5.10(-4). The mean age of the patients was 6 years and 8 months, with a peak at 3 years (14/76; 18% of patients). The most frequent clinical feature was cough (80%; 56/70). The chest X-ray showed typical radiological features such as peribronchial and perivascular interstitial infiltrates in only 23% (16/69). Respiratory and extrarespiratory complications were seen in 17 and 12 children, respectively. Only 1 child suffered from respiratory sequelae. CONCLUSION: M. pneumoniae pneumonia is frequent in children over 2 years of age. The diagnosis is sometimes difficult to initially assert because there are no specific features. Respiratory and extrarespiratory complications remain possible. Respiratory sequelae can still exist even if most cases evolve favorably under treatment by macrolides.

Near-field optical imaging with a CdSe single nanocrystal-based active tip.

We report near-field scanning optical imaging with an active tip made of a single fluorescent CdSe nanocrystal attached at the apex of an optical tip. Although the images are acquired only partially because of the random blinking of the semiconductor particle, our work validates the use of such tips in ultra-high spatial resolution optical microscopy.

[Ifosfamide induced encephalopathy: 15 observations]. / Encéphalopathie induite par l'ifosfamide: 15 observations.

INTRODUCTION: Ifosfamide is an alkylating agent used in the treatment of germ-cell tumors, sarcomas and lymphomas. One of its main side effects is the encephalopathy of which the incidence may reach 30% in the literature, in adults and children just as well. OBJECTIVES: Based on both our experience and a review of the literature, we propose some recommendations for the management of this complication. PATIENTS AND METHODS: We report 15 encephalopathy cases in non-brain tumor patients, which occurred between January 1987 and March 2002 in children from 2 to 17 years old, treated for solid tumors at the Institut Gustave Roussy. Ifosfamide was administered at a posology between 5.4 and 15 g/m(2)/course, associated with other antimitotics such as actinomycin D, etoposide or vincristine. RESULTS: Six patients experienced a grade III neurological toxicity according to the NCI classification, which developed as excess drowsiness lasting up to 36 hours. Six other patients developed grade IV neurotoxicity, including two comas resolving within 4 days and four short generalized convulsions. Three other children experienced grade II drowsiness. Brain MRIs were normal and EEG showed an aspecific encephalopathy tracing. This early central neurotoxicity appeared right from the first administration, and occurred immediately after the first injection or during the second or third day of treatment. It was most often reversible, usually 3 to 5 days after the last ifosfamide administration. Five patients were administered a treatment with Methylene Blue with a demonstrable efficacy in only one case. No death or neurological sequelae have been noted. Ifosfamide has been renewed after the neurological accident in 7 of those patients. Only 1 of those 7 patients developed grade IV neurotoxicity during the next course of treatment. In 2 of those 7 children, Methylene Blue was used in a prophylactic way. No neurological disorders have been noted during the next courses of treatment. DISCUSSION: In the literature, the following are described as risk factors for ifosfamide encephalopathy: advanced pelvic disease, previous cisplatyl treatment and renal failure. We have not found any of these predisposing factors in our series, but three of the fifteen patients had severe neurotoxicity associated with Vincristin during previous treatments. CONCLUSION: Facing a clinical diagnosis of ifosfamide encephalopathy, it is recommended to discontinue administration of ifosfamide and inject by intravenous route 50 mg Methylene Blue every 4 hours until the symptomatology recedes. The re-challenge of Ifosfamide is not contra-indicated and should be performed under prophylactic treatment with Methylene Blue by intravenous route at the dose of 50 mg every 6 hours.

[Neonatal diagnosis of primary ciliary dyskinesia: report of one case]. / Dyskinésie ciliaire primitive à révélation néonatale: à propos d'une observation.

Primary ciliary dyskinesia is a rare, genetic disorder resulting of an abnormal ultrastructural morphology of cilia. Such disease is rarely recognized in neonatal period. We report on a newborn who exhibited unexplained respiratory distress. The diagnosis of primary ciliary dyskinesia was suggested by the association of bilateral and multiple atelectasis and situs inversus. Diagnosis was confirmed by three months of age by ultrastructural study of cilia. Primary ciliary dyskinesia is a rare disease. Diagnosis should be considered in unexplained cases of neonatal respiratory distress, especially when situs inversus totalis and multiple atelectasis are present. Diagnosis requires ciliary studies that can be performed in newborn infants.

[Acceptability and tolerance of sodium valproate, a new sustained-action granule formulation, in monotherapy for epileptic children from 3 years old]. / Acceptabilité et tolérance du valproate de sodium, granules à libération prolongée, en monothérapie chez l'enfant épileptique à partir de trois ans.

UNLABELLED: Sodium valproate (VPA) is an anti-epileptic drug which was until now administered to children as drinkable or injectable form. A new galenic form of this compound has been developed as microgranules with prolonged release (Micropakine)LP; MPK). This new galenic form of VPA allows a greater stability of the plasmatic rates, thus limiting the risk of amount-dependent adverse effects at the time of the peaks, and of less effectiveness at the time of the fall of the circulating rates. The main objective of this study was to evaluate the acceptability of the new galenic form of VPA, in monotherapy, for epileptic children with >or=3 years old. The evaluation was performed at day (D)90 by the patients using a hedonic visual scale. The secondary objectives were to evaluate the acceptability by the parents, the treatment compliance, the percentage of patients free of seizure at D 90, and the tolerance. Finally, the authors compared all these data to those recovered at the baseline in patients already treated by the previous drinkable VPA. A total of 307 patients were involved by 76 hospital neuropediatric physicians. The population was constituted by 110 children <5 years old and 197 children from 5 to 14 years old. MPK was well accepted for total population at D 90 (<5 years old: 83.3%; >or=5 years old: 80%). For patients previously treated by drinkable form of VPA (N=199), MPK was significantly better accepted than the drinkable form at D1 (<5 years, P=0.0189; >or=5 years, P<0.0001). Less difficulties were experienced by the parents to administrate MPK when compared to the drinkable form (P<0.001), mainly due to his neutral taste. Patients free of seizure at D 90 were 77% [70,3; 82,5]. Specially, fewer epileptic seizures were evidenced for all children previously treated at D1 by drinkable form of VPA. The treatment was well respected by the patients, which were compliant in 80% of the cases. The adherence to treatment was good since the treatment compliance was 87%. MPK was well tolerated. CONCLUSION: MPK in the microgranule form significantly improves the treatment acceptability with a good tolerance. Two daily intakes and neutral taste are two major advantages to favour the compliance in children, thus contributing to the efficacy of the antiepileptic treatment.

[Bilateral frontal polymicrogyria and Ehlers-Danlos syndrome]. / Polymicrogyrie bifrontale et syndrome d'Ehlers-Danlos.

The authors describe the case of a six-year-old girl with Ehlers-Danlos syndrome associated to bilateral symmetrical frontal polymicrogyria. Several extracellular matrix components, including collagen, are directly implicated in the neuronal migration. We think that a defect in collagen or in another extracellular matrix protein during fetal development could result in this association.

Mineral-vegetal co-milling: An effective process to improve lignocellulosic biomass fine milling and to increase interweaving between mixed particles.

Fine-milling is a crucial objective for lignocellulosic biomass valorization. Co-milling appears to be a promising technique to improve its efficiency. However, the mechanisms occurring while co-milling remain poorly understood. In this study, an experimental work was performed to produce co-milled powders from both lignocellulosic (wheat, straw or pine sawdust) and mineral materials (limestone, quartzite or tile) with very contrasted physicochemical properties. The main consequences of co-milling were studied for both materials. A two-component mixing law for the prediction of the blend properties was proposed (particle sizes and true densities) to highlight the gain of this single processing step compared to separate milling and mixing. The predicted values were compared with experimental data for co-milled powders at 7 biomass contents from 0% to 100%. In all cases, co-milling leads to a reduction in particle size of lignocellulosic materials and create strong interweaving with mineral particles.

Dynamic observation of the biodegradation of lignocellulosic tissue under solid-state anaerobic conditions.

The solid-state anaerobic digestion (SS-AD) of wheat straw was characterized under low inoculated batch tests during 244 days. High levels of degradation of the cellulose (52%±1) and hemicelluloses (55%±2) were observed at the final stages and associated to a methane yield of 204±16 NmL gTS(-1). Ultrastructural observations, using transmission electronic microscopy, indicated that microorganisms degraded wheat straw from the central to the outer tissue (i.e. parenchyma to epidermis), depending on cell chemical, physical accessibility and the degree of lignification. Furthermore, major degradation of sclerenchyma secondary walls was observed. The bioaccessibility of lignocellulosic structures of wheat straw is mainly limited by the external waxy layer (cuticle), tertiary cell walls, high silica content and access to the cell lumen.

Genotypic subtypes of HIV-1 in Cameroon.

OBJECTIVE: The only two HIV-1 strains (ANT70 and MVP5180) reported to date from Cameroon are members of the outlier clade (group O). In this study, we assessed the prevalence of group O viruses and other HIV-1 subtypes in Cameroon. DESIGN: A phylogenetic analysis of 18 HIV-1 strains isolated from seropositive individuals from Yaoundé and Douala, Cameroon. METHODS: A 900 base-pair fragment of the env gene coding for V3, V4, V5, and the beginning of gp41 of 17 out of 18 HIV-1 isolates from Cameroon was amplified, cloned and sequenced using polymerase chain reaction. A phylogenetic tree was constructed. RESULTS: The overall env nucleotide sequence divergence among the Cameroon isolates ranged from 6.1 to 27.5%. In a phylogenetic tree, six subtypes were identified when compared with 23 reference strains of different geographic origin. Of these 17 Cameroonian strains, 11 (61%) were of subtype A of which the interpatient distances at the sequence level varied from 6.1% to 18.3% (average, 11.9%). Three (17%) strains were of subtype F, and the other three strains (6% each) belonged to subtypes B, E and H, respectively. The remaining isolate was classified as belonging to group O, on the basis of the sequence of part of the pol gene. A very broad spectrum of different tetrameric amino-acid sequences was observed at the apex of the V3 loop. Eleven strains contained the tetrameric globally predominant GPGQ sequence at the tip of the V3 motif. Two strains had the GPGR sequence typical of the American and European HIV-1 strains. The remaining tetrameric sequences included GPGS, GSGQ, GRGQ, and GLGR. CONCLUSION: These findings on a limited number of viruses suggest extensive env gene diversity of HIV-1 strains from Cameroon, and could have implications for vaccine development in Africa.

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Collaborative study of the molecular epidemiology of Tay-Sachs disease in Europe.

Tay-Sachs disease is a lipidosis due to the deficiency of the lysosomal hexosaminidase A. In order to understand the molecular mechanisms of this enzyme deficiency we studied 42 patients of different ethnic origins diagnosed in Europe. The strategy used consists in HEXA cDNA amplification followed by allele-specific oligonucleotide analysis for the frequent mutations, and by chemical cleavage mismatch and denaturing gradient gel electrophoresis for the detection of new mutations. 90% of alleles were clarified in this way, showing a high heterogeneity of HEXA lesions in Tay-Sachs disease. 28 different mutations were found, 20 being identified for the first time in this group of patients.

X-linked malformations of neuronal migration.

Malformations of neuronal migration such as lissencephaly (agyria-pachygyria spectrum) are well-known causes of mental retardation and epilepsy that are often genetic. For example, isolated lissencephaly sequence and Miller-Dieker syndrome are caused by deletions involving a lissencephaly gene in chromosome 17p13.3, while many other malformation syndromes have autosomal recessive inheritance. In this paper, we review evidence supporting the existence of two distinct X-linked malformations of neuronal migration. X-linked lissencephaly and subcortical band heterotopia (XLIS) presents with sporadic or familial mental retardation and epilepsy. The brain malformation varies from classical lissencephaly, which is observed in males, to subcortical band heterotopia, which is observed primarily in females. The XLIS gene is located in chromosome Xq22.3 based on the breakpoint of an X-autosomal translocation. Bilateral periventricular nodular heterotopia (BPNH) usually presents with sporadic or familial epilepsy with normal intelligence, primarily in females, although we have evaluated two boys with BPNH and severe mental retardation. The gene for BPNH has been mapped to chromosome Xq28 based on linkage studies in multiplex families and observation of a subtle structural abnormality in one of the boys with BPNH and severe mental retardation.

Genetic variability of HIV type 1 in Kenya.

PIP: The AIDS epidemic is a rapidly growing problem in Nairobi, where the seroprevalence in pregnant women increased from 4% in 1988 to over 10% in 1991. 22 HIV-1-seropositive pregnant women and 1 HIV-1-infected baby (K88) attending the Pumwani Maternity Hospital of Nairobi between 1990 and 1992 were studied as part of a cohort study of maternal risk factors in mother-to-child transmission. A 250-base pair (bp) fragment of the env gene encoding C2V3 was amplified mostly from DNA isolated from primary peripheral blood mononuclear cells and subsequently sequenced. The 23 newly determined HIV env sequences were aligned with 23 previously known sequences of HIV-1 isolates of diverse geographical origin and the sequence of the HIV-1-related chimpanzee isolate SIVcpz-gab, on the basis of primary structure. Distance calculation, tree construction, and bootstrap analysis were realized with the software package TREECON. In the tree, 8 major branches could be observed containing sequences representative of 8 different subtypes A, B, C, D, E, F, G, and H, besides the outlier group O. 19 of 23 Kenyan isolates clustered with D687, Z321, U455, and SF170, which were members of genetic subtype A. Phylogenetic analyses favored positioning of K976 as a divergent A subtype strain. For 4 strains (K29, K88, K98, and K112) the subtype A classification based on the gag gene was also observed on the basis of phylogenetic analysis of the C2V3 coding part of the env gene. The predicted amino acid sequence of the V3 region for these strains was also presented. The finding that among 23 HIV-1 isolates collected in Nairobi, 19 were classified in subtype A versus 3 in subtype D, together with a much larger variation between subtype A strains as compared to subtype D strains, suggests an earlier introduction of a subtype A strain, multiple introductions of subtype A strains, and/or faster diversification of subtype A strains as compared to subtype D strains.^ieng

Genetic and antigenic variability of HIV type 1 in Brazil.

Six Brazilian strains of human immunodeficiency virus type 1 (HIV-1) were isolated from infected individuals residing in different regions of Brazil between 1987 and 1989. Phylogenetic analysis based on an 860-base pair env fragment, including V3, V4, V5, and the beginning of gp41, classified the Brazilian strains significantly in genotype B, with interhost distances between 5.9 and 13.1% (mean value, 10%). Amino acid sequence analysis of the V3 loop revealed that three strains contained the North American/European GPGR motif as the tip of the loop whereas in the other three strains proline (P) was substituted by tryptophan (W), methionine (M), or phenylalanine (F). A consensus peptide, Bra-cons, was designed containing GWGR as the tip of the loop. Serological reactivity to the Bra-cons peptide and other V3 peptides (MN, SF2, HBX2, RF, MAL, ELI, Z6, and a Côte d'Ivoire peptide, CI-cons) was compared for 114 HIV-1-positive sera from Rio de Janeiro. Sixty-nine sera (60.5%) reacted with peptides belonging to genotype B, of which 10 sera also reacted with peptides belonging to genotype A (n = 7) and D (n = 3). Eighteen sera (15.8%) had binding antibodies to the Bra-cons peptide. A high number of sera (n = 43; 37.7%) had no antibodies to any of the V3 peptides tested. This result suggests that HIV-1 variants with aberrant V3 loops may circulate in Rio de Janeiro.

Effects of pentylenetetrazol-induced status epilepticus on c-Fos and HSP72 immunoreactivity in the immature rat brain.

Pentylenetetrazol (PTZ)-induced status epilepticus (SE) leads to acute and long-term metabolic decreases in specific brain regions of rats at 10 (P10) or 21 days after birth (P21). These decreases are not related to apparent neuronal damage. Therefore, to better understand the neuronal activation and stress response to PTZ in immature rats, we mapped the expression of c-Fos and of the 72 kDa heat-shock protein (HSP72) in the same model of severe SE induced by the repetitive i.p. injections of subconvulsive doses of PTZ. Rats were sacrificed either at 2 or 24 h after the onset of SE in order to reveal c-Fos immunoreactivity, and at 24 and 72 h for HSP72 expression. Hematoxylin-eosin staining was performed at 24, 72 and 144 h after SE. The expression of c-Fos at 2 h after SE was more marked at P21 than at P10 and was prominent at both ages in the hippocampal dentate gyrus, cerebral cortex and amygdala. Some immunoreactivity was also present in the hypothalamus, thalamus and a few brainstem and cerebellar regions at both ages. There was a good relation between the regions expressing c-Fos and those exhibiting acute metabolic decreases at P21. Conversely, PTZ seizures did not lead to any expression of c-Fos at 24 h after SE or of HSP72 at 24 or 72 h at any age. Cell density was not affected by PTZ-induced SE at any age and at any time. These results suggest that c-Fos is a useful marker of neuronal activation induced by severe and prolonged seizures in the immature brain. The lack of HSP72 and of late c-Fos expression likely reflect the absence of neuronal damage in this model of PTZ-induced SE in the immature rat.