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PubMed1997

Retinoblastoma--a histologic and immunohistologic study.

Histopathology and various immunohistochemical markers were studied in 40 cases of human retinoblastoma. In histopathology, tumour type, extent and invasion were studied. In immunohistochemistry, both glial and neural markers were used to know the histogenesis of this tumour. The glial markers, glial fibrillary acidic protein and vimentin, were detected in retinal astrocytes and Muller's cells in normal retina and perivascular glia in retinoblastoma. The neural marker, neurone-specific enolase stained neurones in outer and inner nuclear layers in normal retina, Flexner-Wintersteiner rosettes in retinoblastoma and tumour cells is differentiated retinoblastoma. Another neural marker, neurofilament triplet polypeptide stained neurones in inner nuclear layer of normal retina and Flexner-Wintersteiner rosettes in well-differentiated retinoblastoma. These results support the view that retinoblastoma has predominantly neuronal origin.

Biomarkers, Tumor↗
PubMed2000

Cerebrospinal fluid purine metabolite and neuron-specific enolase concentrations after febrile seizures.

If febrile seizures cause significant compromise of neuronal metabolism (whether permanent or reversible), this should be reflected in an increase in the cerebrospinal fluid concentrations of neuron-specific enolase (NSE) and/or adenosine triphosphate (ATP) breakdown products. In the present study, AMP, IMP, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine, uric acid and NSE concentrations were determined in the cerebrospinal fluid of 90 children 1 h after febrile seizure (73 simple febrile seizures (SFS); 17 complex febrile seizures (CFS)), and in a control group of 160 children. There was no statistically significant difference between the SFS group and the control group for any of the substances determined, suggesting that SFS neither significantly depletes neuronal ATP concentration, nor significantly increases NSE concentration; thus, SFS do not appear to constitute a threat to neuronal integrity. However, patients with CFS showed significantly lower IMP concentrations and significantly higher adenine concentrations than controls, and significantly higher AMP concentrations than SFS patients; these results suggest that CFS may affect energy metabolism in the brain. However, NSE concentrations were normal in the cerebrospinal fluid of both SFS and CFS patients, suggesting that neither type of seizure causes significant neuronal damage, at least early after the seizure.

Adenosine Monophosphate↗
PubMed2005

A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities.

BACKGROUND: Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic reconstruction. RESULTS: We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space) and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP) allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. CONCLUSION: The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

Algorithms↗
PubMed2000

cDNA representational difference analysis of human neutrophils stimulated by GM-CSF.

Neutrophils are the first cell type to migrate out of the vascular space and into the inflammatory site during an acute inflammation. However, in chronic inflammatory diseases, such as chronic obstructive pulmonary disease (COPD), a lack of clearance of neutrophils, imbalance between inflammatory mediators produced by neutrophils and their natural inhibitors make these cells a potential cause of tissue destruction in lung disease. Neutrophilic inflammation is generally characterised by high levels of local expression of activating cytokines (e.g., GM-CSF). Only a few studies have been published so far that have investigated the expression of genes preferentially expressed in activated neutrophils. The isolation of such genes, however, can lead to a better understanding of inflammatory disease and the identification of potential novel therapeutic targets or markers of the disease. We performed representational difference analysis of cDNA, a sensitive PCR-based subtractive enrichment procedure, and isolated 12 genes, 1 EST clone, and 3 sequences not represented in the public databases. Differential expression for 9 of these clones was confirmed by Northern hybridisation. Of the above nine transcripts three were chosen and shown to be up-regulated in neutrophils cocultured with stimulated primary human bronchial epithelial cells using a semiquantitative RT-PCR approach. Among the known genes identified were HM-74, CIS1, Cathepsin C, alpha-enolase, CD44, and the gene Translocation Three Four (TTF), most of them previously not known to be involved in GM-CSF induced neutrophil activation. Along with its tissue and cellular distribution we also derived the complete cDNA sequence and genomic structure of CIS1 using an in silico approach. In addition, we also report the initial characterisation of a novel gene, P1-89 that is primarily expressed in granulocytes and is up-regulated in activated cells. Our results identify several important genes associated with neutrophil activation and can lead to a better understanding of the molecular mechanisms of neutrophilic inflammations.

Amino Acid Sequence↗
PubMed2004

BM88 is an early marker of proliferating precursor cells that will differentiate into the neuronal lineage.

Progression of progenitor cells towards neuronal differentiation is tightly linked with cell cycle control and the switch from proliferative to neuron-generating divisions. We have previously shown that the neuronal protein BM88 drives neuroblastoma cells towards exit from the cell cycle and differentiation into a neuronal phenotype in vitro. Here, we explored the role of BM88 during neuronal birth, cell cycle exit and the initiation of differentiation in vivo. By double- and triple-labelling with the S-phase marker BrdU or the late G2 and M-phase marker cyclin B1, antibodies to BM88 and markers of the neuronal or glial cell lineages, we demonstrate that in the rodent forebrain, BM88 is expressed in multipotential progenitor cells before terminal mitosis and in their neuronal progeny during the neurogenic interval, as well as in the adult. Further, we defined at E16 a cohort of proliferative progenitors that exit S phase in synchrony, and by following their fate for 24 h we show that BM88 is associated with the dynamics of neuron-generating divisions. Expression of BM88 was also evident in cycling cortical radial glial cells, which constitute the main neurogenic population in the cerebral cortex. In agreement, BM88 expression was markedly reduced and restricted to a smaller percentage of cells in the cerebral cortex of the Small eye mutant mice, which lack functional Pax6 and exhibit severe neurogenesis defects. Our data show an interesting correlation between BM88 expression and the progression of progenitor cells towards neuronal differentiation during the neurogenic interval.

Age Factors↗
PubMed1998

Global analysis of genomic texts: the distribution of AGCT tetranucleotides in the Escherichia coli and Bacillus subtilis genomes predicts translational frameshifting and ribosomal hopping in several genes.

Present availability of the genomic text of bacteria allows assignment of biological known functions to many genes (typically, half of the genome's gene content). It is now time to try and predict new unexpected functions, using inductive procedures that allow correlating the content of the genomic text to possible biological functions. We show here that analysis of the genomes of Escherichia coli and Bacillus subtilis for the distribution of AGCT motifs predicts that genes exist for which the mRNA molecule can be translated as several different proteins synthesized after ribosomal frameshifting or hopping. Among these genes we found that several coded for the same function in E. coli and B. subtilis. We analyzed in depth the situation of the infB gene (experimentally known to specify synthesis of several proteins differing in their translation starts), the aceF/pdhC gene, the eno gene, and the rplI gene. In addition, genes specific to E. coli were also studied: ompA, ompFand tolA (predicting epigenetic variation that could help escape infection by phages or colicins).

Acetyltransferases↗
PubMed2005

Cellular and molecular tunnels surrounding the forebrain commissures of human fetuses.

Glial cells and extracellular matrix (ECM) molecules surround developing fiber tracts and are implicated in axonal pathfinding. These and other molecules are produced by these strategically located glial cells and have been shown to influence axonal growth across the midline in rodents. We searched for similar cellular and molecular structures surrounding the telencephalic commissures of fetal human brains. Paraffin-embedded brain sections were immunostained for glial fibrillary acidic protein (GFAP) and vimentin (VN) to identify glial cells; for microtubule-associated protein-2 (MAP-2) and neuronal nuclear protein (NeuN) to document neurons; for neurofilament (NF) to identify axons; and for chondroitin sulfate (CS), tenascin (TN), and fibronectin (FN) to show the ECM. As in rodents, three cellular clusters surrounding the corpus callosum were identified by their expression of GFAP and VN (but not MAP-2 or NeuN) from 13 to at least 18 weeks postovulation (wpo): the glial wedge, the glia of the indusium griseum, and the midline sling. CS and TN (but not FN) were expressed pericellularly in these cell groups. The anterior commissure was surrounded by a GFAP+/VN+ glial tunnel from 12 wpo, with TN expression seen between the GFAP+ cell bodies. The fimbria showed GFAP+/VN+ cells at its lateral and medial borders from 12 wpo, with pericellular expression of CS. The fornix showed GFAP+ cells somewhat later (16 wpo). Because these structures are similar to those described for rodents, we concluded that the axon guiding mechanisms postulated for commissural formation in nonhuman mammals may also be operant in the developing human brain.

Axons↗
PubMed2001

Age- and concentration-dependent neuroprotection and toxicity by TNF in cortical neurons from beta-amyloid.

The induction of an inflammatory response and release of cytokines such as TNF may be involved in the age-related etiology of Alzheimer disease (AD). In the brain, microglia have been shown to produce a wide variety of immune mediators, including the pro-inflammatory cytokine tumor necrosis factor (TNF). We hypothesize that with age there is increased ability of microglia to produce TNF or that age decreases the neuroprotective effect of TNF against beta-amyloid (Abeta) toxicity in neurons. We investigated the effects of Abeta(1-40) on TNF secretion from forebrain cultures of microglia from embryonic, middle-age (9-month) and old (36-month) rats. Over the first 12 hr of exposure to 10 microM Abeta (1-40), microglia from embryonic and old rats increase TNF secretion, although microglia from middle-age rats did not produce detectable levels of TNF. When low concentrations of TNF are added to neurons together with Abeta (1-40) in the absence of exogenous antioxidants, neuroprotection for old neurons is significantly less than neuroprotection for middle-age neurons. In neurons from old rats, high levels of TNF together with Abeta are more toxic than in neurons from middle-age or embryonic rats. These results are discussed in relation to neuroprotection and toxicity of the age-related pathology of AD.

Age Factors↗
PubMed2006

Temporally specific proliferation events are induced in the hippocampus following acute focal injury.

In models of global brain injury, such as stroke or epilepsy, a large increase in neurogenesis occurs in the dentate gyrus (DG) days after the damage is induced. In contrast, more focal damage in the DG produces an increase in neurogenesis within 24 hr. To determine how cell proliferation and differentiation differs in the DG after acute injury in the DG, focal electrolytic lesions were made and mitotic activity was assessed at early (1 day) and late (5 day) time points. At the early time point, bromodeoxyuridine (BrdU)-positive cells were diffusely spread throughout the extent of the hippocampus that was ipsilateral to the lesion. No significant increase in the subgranular zone (SGZ) of the DG was observed. When BrdU was administered at the later time point, the number of BrdU+ cells in the SGZ of the DG was significantly increased. This fourfold increase in BrdU+ cells also resulted in a significant increase in neurogenesis, as measured 6 weeks following BrdU administration. This increase in neurogenesis was not observed when BrdU was administered at the early time point. These results indicate that focal injury in the DG activates two temporally specific proliferation events and that enhanced neurogenesis is observed only following a latent period after the lesion is made.

Animals↗
PubMed1988

31P magnetization transfer in the phosphoglyceromutase-enolase coupled enzyme system.

The rate of exchange of phosphoryl groups between 2-phosphoglycerate, 3-phosphoglycerate and phosphoenolpyruvate by the coupled phosphoglyceromutase-enolase enzyme system using one- and two-dimensional 31P NMR spectroscopy was measured. Magnetization exchange in one-dimensional experiments was achieved by saturation transfer with selective irradiation at both one and two sites in this three-site exchange system using the DANTE pulse sequence. The two-dimensional magnetization exchange experiment avoids the need to selectively saturate at one or more frequencies which may be difficult in complex exchange systems. Analysis of the two-dimensional exchange experiment by the back transformation method yielded exchange rate constants in good agreement with the saturation transfer method.

Animals↗
PubMed1991

Immunohistochemical characterization of primitive neuroectodermal tumors and their possible relationship to the stepwise ontogenetic development of the central nervous system. 1. Ontogenetic studies.

Aim of the present study was to establish different immunohistochemical staining patterns for a subsequent comparison with those of primitive neuroectodermal (PNET) subsets, i.e. PNET-NOS (not otherwise specified) or PNET with focal neuronal, astrocytic or ependymal differentiation, to relate neoplastic to embryonal development. Tissue of the developing central nervous system, with special emphasis on the stepwise development of the rhombencephalon, the cerebellar and the retinal anlage, from 20 different human embryos and fetuses ranging from 3 to 30 weeks of gestational age (GA) was examined. Six neuronal markers, synaptophysin, chromogranin A, neuron-specific enolase (NSE), neurofilament protein (NFP; 160 kDa, 200 kDa, 70 and 200 kDa) and six other markers, glial fibrillary acidic protein (GFAP), S-100 protein, vimentin, myoglobin, desmin, cytokeratin, were assessed immunohistochemically. GFAP and S-100 protein appeared at the 6th week of GA in primitive glial cells of the cerebellar anlage, brain stem, rhombencephalon, and developing spinal cord, together with--as first neuronal marker--chromogranin A, then NFP (70 and 200 kDa, and 160 kDa) from the 8th week onward. NSE started in the 11th week and synaptophysin not earlier than the 16th week of GA. Interestingly, the differentiation of the retinal anlage started rather late with NSE positivity beginning from the 16th week and positive reactions to synaptophysin and NFPs only from the 25th and chromogranin A from the 28th week of GA onward.

Central Nervous System↗
PubMed1988

Immunohistochemical study of the early human fetal brain.

To assess the cytogenesis of the central nervous system we studied the spinal cord and the cerebrum in 11 human embryos and fetuses of gestation age 7-25 weeks immunohistochemically using anti-vimentin, anti-neurofilament protein (NFP), anti-neuron-specific enolase (NSE), anti-glial fibrillary acidic protein (GFAP), anti-S-100 protein, anti-Leu 7 and anti-myelin basic protein (MBP) antibodies. Vimentin was demonstrated in ventricular cells at 7 weeks and older. NFP-68-kDa and -160-kDa components were observed in neuroblastic cells of the neural tube at 7 weeks. NFP (68 and 160 kDa) was mainly located in the marginal zone of the spinal cord and the cerebrum at 8-9 weeks. NSE was not found in the neural tube at 7 weeks, although NSE was demonstrable at 9 weeks both in the spinal cord and in the cerebrum. GFAP-positive cells started to appear at 9 weeks in the spinal cord and at 15 weeks in the cerebrum, respectively. S-100 immunoreactivity was almost coincident with GFAP. S-100, however, was observed in more numerous glioblastic cells. Leu 7 was detected at 7 weeks and located in the neuropil of the central nervous tissue. MBP was not demonstrable in this study. Our study indicates that neuronal differentiation occurs much earlier than glial differentiation in the human brain and that neuronal and glial cell classes do not coexist in the ventricular zone of the early human fetal brain.

Brain↗
PubMed1990

Cerebrospinal fluid markers in neurological disorders.

Cerebrospinal fluid (CSF) markers are a useful tool for determining disease progression or activity in some neurological disorders which need parameters both for evaluating treatments and investigating pathobiological evolution in research-oriented follow-up. A number of CSF proteins are reviewed with data on biological properties, analytical methods, clinical usefulness of: myelin basic protein, S-100 protein, glial fibrillary acidic protein, neural-cell adhesion molecule, neuron-specific enolase and others.

Biomarkers↗
PubMed1986

Reaggregation of fetal rat brain cells in a stationary culture system. I: Methodology and cell identification.

A stationary tissue culture system for reaggregation cultures of rat brain cells is described. Aggregates were formed by placing cells at high concentration in liquid overlay cultures on a nonadherent nutrient agar surface. No physical stress in the form of rotation or shaking was applied to the aggregating cell population. Transmission electron microscopy and immunohistochemistry showed that the cells developed from homogeneously dispersed, immature cells in Day 4 aggregates, to mature astrocytes, oligodendrocytes, and neurons in Day 20 aggregates. Twenty days older aggregates had a tightly packed neuropil which was most prominent in a cell-sparse outer layer of the aggregates. When the aggregates were allowed to adhere to a substrate, both glial fibrillary acidic protein (GFAP) positive and negative cells were observed migrating out from the aggregates. Cells giving a positive reaction for neuron specific enolase (NSE) were also present. This reaggregation procedure, with transfer of selected brain cell aggregates into agar-coated multiwells is an alternative three-dimensional culture system which can be potentially useful in the study of morphogenesis and cell interactions in the nervous system.

Animals↗
PubMed2004

Value and limits of immunohistochemistry in differential diagnosis of clear cell primary brain tumors.

Clear cell histology is the hallmark of oligodendroglioma (OG) but also characterizes clear cell ependymoma (CCE) and central neurocytoma (CN). Immunohistochemistry for glial and neuronal proteins may support differential diagnosis. We investigated systematically diagnostic value and limits of immunohistochemistry using representative tumor specimens (>1 cm in diameter) of well-defined OGs, CCEs, and CNs (n=10, respectively). Antibodies comprised anti-neuron specific nuclear protein (NEUN), anti-synaptophysin, anti-neuron-specific enolase, anti-microtubule-associated protein 2, anti-phosphorylated neurofilament protein, anti-non-phosphorylated neurofilament protein, anti-glial fibrillary acidic protein (GFAP), anti-S100 protein, anti-vimentin (VIM), and anti-epithelial membrane antigen (EMA). Among the panel of antibodies anti-NEUN, anti-VIM and anti-EMA proved most useful for differential diagnosis. Prominent (>90%) anti-NEUN immunolabeling of tumor cells clearly distinguished CNs from OGs and CCEs. Anti-VIM immunolabeling and a characteristic cytoplasmic dot-like anti-EMA immunoreactivity pattern of tumor cells were detectable only in OGs and CCEs. Furthermore, prominent anti-VIM immunoreactivity and anti-EMA cell membrane staining including ring-like staining pattern is characteristic for CCEs. Additionally, a widespread gliofibrillary and minigemistocytic cytoplasmic anti-GFAP immunostaining pattern is restricted to some OGs. Our data indicate that immunohistochemistry using anti-NEUN, anti-VIM, and anti-EMA on representative tumor specimens allows clear-cut distinction of CNs vs OGs and CCEs. Anti-VIM, anti-EMA, and anti-GFAP support differential diagnosis of OGs vs CCEs. Nevertheless, it is noted that due to focal expression of glial proteins in CNs and, conversely, of neuronal proteins in OGs and CCEs, immunohistochemistry is of limited value on small tumor specimens.

Biomarkers, Tumor↗