bluuebunny/crossref_metadata_2025 huggingface dataset:
Suppression of glial glutamine release to the extracellular fluid studiedin vivoby NMR and microdialysis in hyperammonemic rat brain
Authors: Kanamori Keiko , Ross Brian D.
Published: September 2005

Release of glial glutamine (GLN) to the extracellular fluid (ECF), mainly mediated by the bidirectional system N transporter SN1, was studiedin vivoin hyperammonemic rat brain, using15N‐nuclear magnetic resonance (NMR) to monitor intracellular [5‐15N]GLN and microdialysis/gradient1H‐15N heteronuclear single‐quantum correlation NMR to analyse extracellular [5‐15N]GLN. GLNECFwas elevated to 2.4 ± 0.2 mmafter 4.5 h of intravenous ammonium acetate infusion. The [GLNi]/[GLNECF] ratio (i = intracellular) was 9.6 ± 0.9, compared with 17–20 in normal brain. GLNECFthen decreased substantially att = 4.9 ± 0.1 h. Comparison of the time‐courses of intra‐ and extra‐cellular [5‐15N]GLN strongly suggested that the observed decrease reflects partial suppression of glial GLN release to ECF. Suppression also followed elevation of GLNECFto 1.9 mm, resulting in a [GLN]i/[GLNECF] ratio of 8.4, upon perfusion ofα‐(methylamino)isobutyrate which inhibits neuronal uptake of GLNECFmediated by sodium‐coupled amino acid transporter (SAT). The results provide first evidence for bidirectional operation of SN1in vivo, and clarify the effect of transmembrane GLN gradient on glial GLN release at physiological Na+gradient. Implications of the results for SN1 as an additional regulatory site in the glutamine/glutamate cycle and utility of this approach for examining the role of GLN in an experimental model of fulminant hepatic failure are discussed.
The tissue‐specific methylation of the human Tyrosine Hydroxylase gene reveals new regulatory elements in the first exon
Authors: Arányi Tamás , Faucheux Baptiste A. , Khalfallah Olfa , Vodjdani Guilan , Biguet Nicole Faucon , Mallet Jacques , Meloni Rolando
Published: September 2005

The methylation status of CpG dinucleotides located in or near regulatory elements affects gene expression. The CpG‐rich sequence located outside the 5′ promoter region of the human Tyrosine Hydroxylase (TH) gene appears to influence the functional effect of the adjacent intronic HUMTH01 microsatellite. In order to identify new regulatory elements in this region acting on gene expression, the methylation profile of the TH CpG island was investigated using the bisulfite sequencing method. The overall methylation level of this region is correlated to TH‐expressing and non‐expressing status in cell lines and DNA demethylation treatment with 5‐azacytidine increased TH expression. Moreover, in a homogeneous background of methylated CpGs, a single CpG in the first exon of the gene is constantly either unmethylated or methylated in, respectively, TH‐expressing or non‐expressing cell lines, tissues and single cells. Further analysis ascertained that this CpG is contained in a sequence characterized by putative binding sites for the AP2, Sp1 and KAISO factors. Characterization of this sequence shows that these factors specifically bind their respective sites. Finally, the binding of KAISO, a transcriptional repressor, is conditioned by the methylation of this sequence, which may, thus, participate in the regulation of TH gene expression according to its methylation pattern.
Opposite effects of Zn on the in vitro binding of [3H]LY354740 to recombinant and native metabotropic glutamate 2 and 3 receptors
Authors: Malherbe Pari , Richards J. Grayson , Broger Clemens , Zenner Marie‐Thérèse , Messer Jürg , Kratzeisen Claudia , Nakanishi Shigetada , Mutel Vincent
Published: September 2005

We investigated the effect of Zn on agonist binding to both recombinant and native mGlu2 and mGlu3 receptors. Zn had a biphasic inhibitory effect on recombinant mGlu2 with IC50 values for the high‐ and low‐affinity components of 60 ± 10 µm and 2 ± 0.7 mm, respectively. Zn induced a complex biphasic effect of inhibition and enhancement of [3H]LY354740 binding to mGlu3. Observations with a series of chimeric mGlu2/3 receptors suggest that the Zn effect resides in the N‐terminal domain of mGlu2 and mGlu3. We observed that the His56 of mGlu2, which corresponds to Asp63 in mGlu3 was largely accountable for the second phase of the Zn effect. As revealed by quantitative receptor radioautography, the addition of up to 100 µm Zn to brain sections of wild‐type mice resulted in significant decreases in binding density in most brain regions. In particular, the mid‐molecular layer of the dentate gyrus (DGmol) and the CA1 lacunosum moleculare of hippocampus (CA1‐LMol) showed reductions of 62 and 67%, respectively. In contrast, the addition of 300 µm Zn to brain sections of mGlu2–/– mice caused large increases in binding density of 289 and 242% in DGmol and CA1‐LMol, respectively. Therefore, Zn might play a role as a physiological modulator of group II mGlu receptor function.
Subunits of the epithelial sodium channel family are differentially expressed in the retina of mice with ocular hypertension
Authors: Dyka Frank M. , May Christian A. , Enz Ralf
Published: September 2005

Glaucoma is a prevalent cause of blindness, resulting in the apoptotic death of retinal ganglion cells and optic nerve degeneration. The disease is often associated with elevated intraocular pressure, however, molecular mechanisms involved in ganglion cell death are poorly understood. To identify proteins contributing to this pathological process, we analysed the retinal gene expression of DBA/2J mice that develop an elevated intraocular pressure by the age of 6 months with subsequent ganglion cell loss. In this study, we identified subunits of the epithelial sodium channel (ENaC) family that are specifically expressed under elevated intraocular pressure. Using reverse transcriptase polymerase chain reaction we observed a significant increase of α‐ENaC in the neuronal retina of DBA/2J mice when compared with control animals, while β‐ENaC and γ‐ENaC were not detectable in this tissue. Specific immune sera to ENaC subunits showed up‐regulation of α‐ENaC in synaptic and nuclear layers of the retina, and in the retinal pigment epithelium. Consistent with our polymerase chain reaction data, β‐ENaC was not detected by specific antibodies in the retina, while γ‐ENaC was only present in the retinal pigment epithelium under ocular hypertension. Finally, the increase of α‐ENaC gene expression in the neuronal retina and the retinal pigment epithelium was not observed in other tissues of DBA/2J mice. Since the intraocular pressure is regulated by the transport of aqueous humour across epithelial structures of the eye that in turn is associated with ion flux, the specific up‐regulation of ENaC proteins could serve as a protecting mechanism against elevated intraocular pressure.
Differential long‐term neuroadaptations of glutamate receptors in the basolateral and central amygdala after withdrawal from cocaine self‐administration in rats
Authors: Lu Lin , Dempsey Jack , Shaham Yavin , Hope Bruce T.
Published: September 2005

Humans and laboratory animals remain highly vulnerable to relapse to cocaine‐seeking after prolonged periods of withdrawal from the drug. It has been hypothesized that this persistent cocaine relapse vulnerability involves drug‐induced alterations in glutamatergic synapses within the mesolimbic dopamine reward system. Previous studies have shown that cocaine self‐administration induces long‐lasting neuroadaptations in glutamate neurons of the ventral tegmental area and nucleus accumbens. Here, we determined the effect of cocaine self‐administration and subsequent withdrawal on glutamate receptor expression in the amygdala, a component of the mesolimbic dopamine system that is involved in cocaine seeking and craving induced by drug‐associated cues. Rats were trained for 10 days to self‐administer intravenous cocaine (6 h/day) or saline (a control condition) and were killed after one or 30 withdrawal days. Basolateral and central amygdala tissues were assayed for protein expression of the α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) receptor subunits (GluR1 and GluR2) and the NMDA receptor subunits (NR1, NR2A and NR2B). In the basolateral amygdala, GluR1 but not GluR2 levels were increased on days 1 and 30, NR2A levels were increased on day 1, and NR2B levels were decreased on day 30 of withdrawal from cocaine. In the central amygdala, GluR2 but not GluR1 levels were increased on days 1 and 30, NR1 levels were increased on day 30 and NR2A or NR2B levels were not altered after withdrawal from cocaine. These results indicate that cocaine self‐administration and subsequent withdrawal induces long‐lasting and differential neuroadaptations in basolateral and central amygdala glutamate receptors.
TYRA‐2 (F01E11.5): a Caenorhabditis elegans tyramine receptor expressed in the MC and NSM pharyngeal neurons
Authors: Rex Elizabeth , Hapiak Vera , Hobson Robert , Smith Katherine , Xiao Hong , Komuniecki Richard
Published: September 2005

Tyramine appears to regulate key processes in nematodes, such as pharyngeal pumping, and more complex behaviors, such as foraging. Recently, a Caenorhabditis elegans tyramine receptor, SER‐2, was identified that is involved in the TA‐dependent regulation of these processes. In the present study, we have identified a second C. elegans gene, tyra‐2 (F01E11.5) that encodes a tyramine receptor. This is the first identification of multiple tyramine receptor genes in any invertebrate. Membranes from COS‐7 cells expressing TYRA‐2 bind [3H]tyramine with high affinity with a Kd of 20 ± 5 nm. Other physiologically relevant biogenic amines, such as octopamine and dopamine, inhibit [3H]tyramine binding with much lower affinity (Kis of 1.55 ± 0.5 and 1.78 ± 0.6 μm, respectively), supporting the identification of TYRA‐2 as a tyramine receptor. Indeed, tyramine also dramatically increases GTPγS binding to membranes from cells expressing TYRA‐2 (EC50 of 50 ± 13 nm) and the TA‐dependent GTPγS binding is PTX‐sensitive suggesting that TYRA‐2 may couple to Gαi/o. Based on fluorescence from tyra::gfp fusion constructs, TYRA‐2 expression appears to be exclusively neuronal in the MC and NSM pharyngeal neurons, the AS family of amphid neurons and neurons in the nerve ring, body and tail. Taken together, these results suggest that TYRA‐2 encodes a second Gαi/o‐coupled tyramine receptor and suggests that TA‐dependent neuromodulation may be mediated by multiple receptors and more complex than previously appreciated.
Inhibition of phosphoinositide 3 kinase‐Akt (protein kinase B)–nuclear factor‐κB pathway by lovastatin limits endothelial–monocyte cell interaction
Authors: Prasad Ratna , Giri Shailendra , Nath Narender , Singh Inderjit , Singh Avtar K.
Published: September 2005

Integrity of the blood–brain barrier is essential for the normal functioning of CNS. Its disruption contributes to the pathobiology of various inflammatory neurodegenerative disorders. We have shown that the HMG‐CoA reductase inhibitor (lovastatin) attenuated experimental autoimmune encephalomyelitis (EAE, an inflammatory disease of CNS) in rodents by inhibiting the infiltration of mononuclear cells into the CNS. Here, using an in vitro system, we report that lovastatin inhibits endothelial–monocyte cell interaction by down‐regulating the expression of vascular cell adhesion molecule‐1 and E‐selectin by inhibiting the phosphoinositide 3 kinase (PI3‐kinase)/protein kinase B (Akt)/nuclear factor‐kappa B (NF‐κB) pathway in endothelial cells. It inhibits tumor necrosis factor alpha (TNFα)‐induced PI3‐kinase, Akt and NF‐κB activation in these cells. Co‐transfection of constitutively active forms of PI3‐kinase and Akt reversed the lovastatin‐mediated inhibition of TNFα‐induced adhesion, as well as activation of NF‐κB, indicating the involvement of the PI3‐kinase/Akt pathway in the interaction of adhesion molecules and the process of adhesion. This study reports that lovastatin down‐regulates the pathway affecting the expression and interaction of adhesion molecules on endothelial cells, which in turn restricts the migration and infiltration of mononuclear cells thereby attenuating the pathogenesis of inflammatory diseases.
Pro‐apoptotic activity of N‐myc in activation‐induced cell death of microglia
Authors: Jung Dae Young , Lee Heasuk , Suk Kyoungho
Published: September 2005

Brain microglial cells are thought to undergo apoptosis following the exposure to inflammatory stimuli such as lipopolysaccharide (LPS) and IFNγ, which is considered as an autoregulatory mechanism to control their own activation state. Here, we report that N‐myc constitutes a novel apoptotic pathway of LPS/IFNγ‐activated microglia. The expression of N‐myc was synergistically enhanced by LPS and IFNγ in microglia. Tetracycline‐based conditional expression of N‐myc sensitized microglia to nitric oxide (NO)‐induced apoptosis. Knockdown of N‐myc expression using small interfering RNA (siRNA) attenuated LPS/IFNγ‐induced microglial apoptosis. An increase in N‐myc expression, however, did not affect microglial production of NO or TNFα. The synergistic effect of LPS/IFNγ on the microglial N‐myc induction was mediated through Janus kinase (JAK)/STAT1 (signal transducer and activator of transcription 1) pathway. Taken together, LPS/IFNγ‐induced N‐myc participated in the activation‐induced cell death of microglia by sensitizing the cells to NO‐induced apoptosis; however, N‐myc did not influence the processes of inflammatory activation of microglia.
mTOR/p70S6k signalling alteration by Aβ exposure as well as in APP‐PS1 transgenic models and in patients with Alzheimer's disease
Authors: Lafay‐Chebassier Claire , Paccalin Marc , Page Guylène , Barc‐Pain Stéphanie , Perault‐Pochat Marie Christine , Gil Roger , Pradier Laurent , Hugon Jacques
Published: September 2005

In Alzheimer's disease, neuropathological hallmarks include the accumulation of β‐amyloid peptides (Aβ) in senile plaques, phosphorylated tau in neurofibrillary tangles and neuronal death. Aβ is the major aetiological agent according to the amyloid cascade hypothesis. Translational control includes phosphorylation of the kinases mammalian target of rapamycin (mTOR) and p70S6k which modulate cell growth, proliferation and autophagy. It is mainly part of an anti‐apoptotic cellular signalling. In this study, we analysed modifications of mTOR/p70S6k signalling in cellular and transgenic models of Alzheimer's disease, as well as in lymphocytes of patients and control individuals. Aβ 1–42 produced a rapid and persistent down‐regulation of mTOR/p70S6k phosphorylation in murine neuroblastoma cells associated with caspase 3 activation. Using western blottings, we found that phosphorylated forms of mTOR and p70S6k are decreased in the cortex but not in the cerebellum (devoid of plaques) of double APP/PS1 transgenic mice compared with control mice. These results were confirmed by immunohistochemical methods. Finally, the expression of phosphorylated p70S6k was significantly reduced in lymphocytes of Alzheimer's patients, and levels of phosphorylated p70S6k were statistically correlated with Mini Mental Status Examination (MMSE) scores. Taken together, these findings demonstrate that the mainly anti‐apoptotic mTOR/p70S6k signalling is altered in cellular and transgenic models of Alzheimer's disease and in peripheral cells of patients, and could contribute to the pathogenesis of the disease.
Effect of N‐acetylaspartylglutamate (NAAG) on non‐quantal and spontaneous quantal release of acetylcholine at the neuromuscular synapse of rat
Authors: Malomouzh Artem I. , Nikolsky Eugen E. , Lieberman Edward M. , Sherman Jessica A. , Lubischer Jane L. , Grossfeld Robert M. , Urazaev Albert Kh.
Published: September 2005

N‐Acetylaspartylglutamate (NAAG), known to be present in rat motor neurons, may participate in neuronal modulation of non‐quantal secretion of acetylcholine (ACh) from motor nerve terminals. Non‐quantal release of ACh was estimated by the amplitude of the endplate membrane hyperpolarization (H‐effect) caused by inhibition of nicotinic receptors by (+)‐tubocurarine and acetylcholinesterase by armin (diethoxy‐p‐nitrophenyl phosphate). Application of exogenous NAAG decreased the H‐effect in a dose‐dependent manner. The reduction of the H‐effect by NAAG was completely removed when N‐acetyl‐β‐aspartylglutamate (βNAAG) or 2‐(phosphonomethyl)‐pentanedioic acid (2‐PMPA) was used to inhibit glutamate carboxypeptidase II (GCP II), a presynaptic Schwann cell membrane‐associated ectoenzyme that hydrolyzes NAAG to glutamate and N‐acetylaspartate. Bath application of glutamate decreased the H‐effect similarly to the action of NAAG but N‐acetylaspartate was without effect. Inhibition of NMDA receptors by dl‐2‐amino‐5‐phosphopentanoic acid, (+)‐5‐methyl‐10,11‐dihydro‐5H‐dibenzocyclohepten‐5,10‐imine (MK801), and 7‐chlorokynurenic acid or inhibition of muscle nitric oxide synthase (NO synthase) by NG‐nitro‐l‐arginine methyl ester and 3‐bromo‐7‐nitroindazole completely prevented the decrease of the H‐effect by NAAG. These results suggest that glutamate, produced by enzymatic hydrolysis of bath‐applied NAAG, can modulate non‐quantal secretion of ACh from the presynaptic terminal of the neuromuscular synapse via activation of postsynaptic NMDA receptors and synthesis of nitric oxide (NO) in muscle fibers. NAAG also increased the frequency of miniature endplate potentials (mEPPs) generated by spontaneous quantal secretion of ACh, whereas the mean amplitude and time constants for rise time and for decay of mEPPs did not change.
Mice lacking glutamate carboxypeptidase II are protected from peripheral neuropathy and ischemic brain injury
Authors: Bacich Dean J. , Wozniak Krystyna M. , Lu X.‐C. May , O'Keefe Denize S. , Callizot Noelle , Heston Warren D. W. , Slusher Barbara S.
Published: September 2005

Excessive glutamate release is associated with neuronal damage. A new strategy for the treatment of neuronal injury involves inhibition of the neuropeptidase glutamate carboxypeptidase II (GCP II), also known as N‐acetylated α‐linked acidic dipeptidase. GCP II is believed to mediate the hydrolysis of N‐acetyl‐aspartyl‐glutamate (NAAG) to glutamate and N‐acetyl‐aspartate, and inhibition of NAAG peptidase activity (by GCP II and other peptidases) is neuroprotective. Mice were generated in which the Folh1 gene encoding GCP II was disrupted (Folh1–/– mice). No overt behavioral differences were apparent between Folh1–/– mice and wild‐type littermates, with respect to their overall performance in locomotion, coordination, pain threshold, cognition and psychiatric behavioral paradigms. Morphological analysis of peripheral nerves, however, showed significantly smaller axons (reduced myelin sheaths and axon diameters) in sciatic nerves from Folh1–/– mice. Following sciatic nerve crush, Folh1–/– mice suffered less injury and recovered faster than wild‐type littermates. In a model of ischemic injury, the Folh1–/– mice exhibited a significant reduction (p < 0.05) in infarct volume compared with their wild‐type littermates when subjected to middle cerebral artery occlusion, a model of stroke. These findings support the hypothesis that GCP II inhibitors may represent a novel treatment for peripheral neuropathies as well as stroke.
A developmental profile of the levels of calcium pumps in chick cerebellum
Authors: Sepúlveda M. Rosario , Hidalgo‐Sánchez Matías , Mata Ana M.
Published: September 2005

The functional expression and distribution of intracellular ATPase (sarco(endo)plasmic reticulum Ca2+‐ATPase: SERCA) and plasma membrane Ca2+‐ATPase (PMCA) was analyzed in the developing chick cerebellum. The activity and Ca2+ uptake increase with development for both ATPases. However, the protein content increases with the stage of development only for SERCA, remaining constant for PMCA. Immunohistochemical assays showed that the ontogenesis of these ATPases goes along with definite stages of cerebellum histogenesis, and is complete at hatching. The SERCA is mainly distributed in Purkinje neurons, whereas the PMCA seems to be expressed initially in climbing fibers, shifting to soma and spiny branchlets of Purkinje cells at late embryonic stages. Granule cells express both ATPases according to their degree of maturity, whereas only PMCA is present in cerebellar glomeruli. These pumps are present in deep nuclei and the choroid plexus, although in this latter tissue their expression declines with development. The spatio‐temporal distribution of SERCA and PMCA must be closely related to their association with the development of specific cells and processes of the chick cerebellum.
Intracellular events mediating insulin‐like growth factor I‐induced oligodendrocyte development: modulation by cyclic AMP
Authors: Palacios Nuria , Sánchez‐Franco Franco , Fernández Miriam , Sánchez Isabel , Cacicedo Lucinda
Published: September 2005

Insulin‐like growth factor I (IGF‐I) is a potent inducer of oligodendrocyte development and myelination. Although IGF‐I intracellular signaling has been well described in several cell types, intracellular mechanisms for IGF‐I‐induced oligodendrocyte development have not been defined. By using specific inhibitors of intracellular signaling pathways, we report here that the MAPK and phosphatidylinositol 3‐kinase signaling pathways are required for the full effect of IGF‐I on oligodendrocyte development in primary mixed rat cerebrocortical cell cultures. The MAPK activation, but not the phosphatidylinositol 3‐kinase activation, leads to phosphorylation of the cAMP response element‐binding protein, which is necessary for IGF‐I to induce oligodendrocyte development. cAMP, although it does not show any effect on oligodendrocyte development, has an inhibitory effect on IGF‐I‐induced oligodendrocyte development that is mediated by the cAMP‐dependent protein kinase. Furthermore, cAMP also has an inhibitory effect on IGF‐I‐dependent MAPK activation. This is a cAMP‐dependent protein kinase‐independent effect and probably contributes to the cAMP action on IGF‐I‐induced oligodendrocyte development.
Disruption of postsynaptic GABAA receptor clusters leads to decreased GABAergic innervation of pyramidal neurons
Authors: Li Rong‐wen , Yu Wendou , Christie Sean , Miralles Celia P. , Bai Jilin , LoTurco Joseph J. , De Blas Angel L.
Published: September 2005

We have used RNA interference (RNAi) to knock down the expression of the γ2 subunit of the GABAA receptors (GABAARs) in pyramidal neurons in culture and in the intact brain. Two hairpin small interference RNAs (shRNAs) for the γ2 subunit, one targeting the coding region and the other one the 3′‐untranslated region (UTR) of the γ2 mRNA, when introduced into cultured rat hippocampal pyramidal neurons, efficiently inhibited the synthesis of the GABAA receptor γ2 subunit and the clustering of other GABAAR subunits and gephyrin in these cells. More significantly, this effect was accompanied by a reduction of the GABAergic innervation that these neurons received. In contrast, the γ2 shRNAs had no effect on the clustering of postsynaptic α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptors, postsynaptic density protein 95 (PSD‐95) or presynaptic glutamatergic innervation. A γ2‐enhanced green fluorescent protein (EGFP) subunit construct, whose mRNA did not contain the 3′‐UTR targeted by γ2 RNAi, rescued both the postsynaptic clustering of GABAARs and the GABAergic innervation. Decreased GABAAR clustering and GABAergic innervation of pyramidal neurons in the post‐natal rat cerebral cortex was also observed after in utero transfection of these neurons with the γ2 shRNAs. The results indicate that the postsynaptic clustering of GABAARs in pyramidal neurons is involved in the stabilization of the presynaptic GABAergic contacts.
Adenosine A2A receptors and metabotropic glutamate 5 receptors are co‐localized and functionally interact in the hippocampus: a possible key mechanism in the modulation of N‐methyl‐d‐aspartate effects
Authors: Tebano M. T. , Martire A. , Rebola N. , Pepponi R. , Domenici M. R. , Grò M. C. , Schwarzschild M. A. , Chen J. F. , Cunha R. A. , Popoli P.
Published: September 2005

Hippocampal metabotropic glutamate 5 receptors (mGlu5Rs) regulate both physiological and pathological responses to glutamate. Because mGlu5R activation enhances NMDA‐mediated effects, and given the role played by NMDA receptors in synaptic plasticity and excitotoxicity, modulating mGlu5R may influence both the physiological and the pathological effects elicited by NMDA receptor stimulation. We evaluated whether adenosine A2A receptors (A2ARs) modulated mGlu5R‐dependent effects in the hippocampus, as they do in the striatum. Co‐application of the A2AR agonist CGS 21680 with the mGlu5R agonist (RS)‐2‐chloro‐s‐hydroxyphenylglycine(CHPG) synergistically reduced field excitatory postsynaptic potentials in the CA1 area of rat hippocampal slices. Endogenous tone at A2ARs seemed to be required to enable mGlu5R‐mediated effects, as the ability of CHPG to potentiate NMDA effects was antagonized by the selective A2AR antagonist ZM 241385 in rat hippocampal slices and cultured hippocampal neurons, and abolished in the hippocampus of A2AR knockout mice. Evidence for the interaction between A2ARs and mGlu5Rs was further strengthened by demonstrating their co‐localization in hippocampal synapses. This is the first evidence showing that hippocampal A2ARs and mGlu5Rs are co‐located and act synergistically, and that A2ARs play a permissive role in mGlu5R receptor‐mediated potentiation of NMDA effects in the hippocampus.
Novel targets for valproic acid: up‐regulation of melatonin receptors and neurotrophic factors in C6 glioma cells
Authors: Rincón Castro Lyda M. , Gallant Michel , Niles Lennard P.
Published: September 2005

Valproic acid (VPA) is a potent anti‐epileptic and effective mood stabilizer. It is known that VPA enhances central GABAergic activity and activates the mitogen‐activated protein kinase–extracellular signal‐regulated kinase (MAPK–ERK) pathway. It can also inhibit various isoforms of the enzyme, histone deacetylase (HDAC), which is associated with modulation of gene transcription. Recent in vivo studies indicate a neuroprotective role for VPA, which has been found to up‐regulate the expression of brain‐derived neurotrophic factor (BDNF) in the rat brain. Given the interaction between the pineal hormone, melatonin, and GABAergic systems in the central nervous system, the effects of VPA on the expression of the mammalian melatonin receptor subtypes, MT1 and MT2, were examined in rat C6 glioma cells. The effects of VPA on the expression of glial cell line‐derived neurotrophic factor (GDNF) and BDNF were also examined. RT‐PCR studies revealed a significant induction of melatonin MT1 receptor mRNA in C6 cells following treatment with 3 or 5 mm VPA for 24 h or 5 mm VPA for 48 h. Western analysis and immunocytochemical detection confirmed that the VPA‐induced increase in MT1 mRNA results in up‐regulation of MT1 protein expression. Blockade of the MAPK–ERK pathway by PD98059 enhanced the effect of VPA on MT1 expression, suggesting a negative role for this pathway in MT1 receptor regulation. In addition, significant increases in BDNF, GDNF and HDAC mRNA expression were observed after treatment with VPA for 24 or 48 h. Taken together, the present findings suggest that the neuroprotective properties of VPA involve modulation of neurotrophic factors and receptors for melatonin, which is also thought to play a role in neuroprotection. Moreover, the foregoing suggests that combinations of VPA and melatonin could provide novel therapeutic strategies in neurological and psychiatric disorders.
Commentary on cellulite: skin mechanobiology and the waist‐to‐hip ratio
Authors: Piérard Gérald E
Published: September 2005

Cellulite is a gender‐related condition which is the clinical expression of conformational changes taking place in the fibrous strands partitioning the hypodermis. The affected skin areas are those where fat deposition is under the influence of estrogens. Some hypodermal fibrous strands become enlarged and others become loose and look similar to striae distensae. Cellulite is not a result of increased body mass, but its aspect may be influenced by the waist‐to‐hip ratio.
Capillaroscopy and videocapillaroscopy assessment of skin microcirculation: dermatologic and cosmetic approaches
Authors: Humbert Philippe , Sainthillier Jean‐Marie , Mac‐Mary Sophie , Petitjean Adeline , Creidi Pierre , Aubin François
Published: September 2005

Background Different noninvasive bioengineering techniques exist to study the microvasculature of the skin and the dynamics of the microcirculation. The goal of these techniques is to visualize the skin capillary circulation easily and directly. Indeed, this information is irreplaceable to study the physiology and physiopathology of the skin capillary circulation efficiently.

Aims Capillaroscopy and video‐capillaroscopy techniques are presented with different methods to study the capillary structure of the skin.

Methods he methods presented in this work include image processing analysis combining morphology, statistics, geometry, and neural network detection designed to quantify the microcirculation and to follow its evolution. To illustrate the combination of these techniques and methods, different examples of their application are described, in dermatology (hypertension, venous insufficiency, age‐related changes) as well as in cosmetology (rosacea and erythrosis assessment).

Conclusion The determination of structural or dynamic changes in the cutaneous microcirculation belongs to the noninvasive techniques of the biometrological domain. Thus, every capillary modification resulting from topical cosmetic products, or chemical agents can be observed. In pathology, numerous conditions can be better examined with this system. Associated with the potential of numerical image analysis, capillaroscopy techniques will probably extend their application fields to the assessment of the influence of arterial and venous diseases on the skin nutritional circulation.
Treatment of palmar hyperhidrosis with botulinum toxin type A: 44 months of experience
Authors: Pérez‐Bernal Ana María , Avalos‐Peralta Patricia , Moreno‐Ramírez David , Camacho Francisco
Published: September 2005

Background  Palmar hyperhidrosis (PH) can produce social and occupational difficulties and reduce the quality of life of those who suffer from this kind of problem. When dealing with focal hyperhidrosis, the patients’ attitudes and their subjective approaches regarding the process may influence the objective evaluation of the disorder.

Objective  To evaluate, by means of a scale, the subjective improvement of sweat production after treatment with botulinum toxin type A (BTX‐A) in a group of patients with severe, invalidating PH.

Patients and methods  Over a period of 44 months, 69 patients were treated and followed‐up, 27 patients had to be treated twice, and 11 patients required a third application; 80–100 U was injected in each palm. Regional nerve block was performed before the procedure. The patients were asked to evaluate their improvement at 1, 3, 6, 9, and 12 months of baseline.

Results  At 1 month, 53.6% of the patients reported an excellent improvement. Three months later, results were still excellent in 33.3% of the patients, and acceptable in 29%. From then on there was a statistically significant decrease of BTX‐A effectiveness. A second application was carried out at an interval of 7.5 ± 2.6 months, and a third one at 9 ± 4.4 months. The following complications could be observed: transitory weakness of hand muscles in 13 patients, wrist pain in 5 patients, and cramps in 1 patient.

Conclusions  Botulinum toxin is an effective alternative for the treatment of severe, invalidating PH. The maximum improvement persists up to 3 months; from then on, the effects slowly diminish. In our experience, there were no statistically significant differences with further applications of BTX‐A. The patients’ subjective assessment can be used to evaluate the sweat production after treatment with BTX‐A in those medical centers where a more objective evaluation becomes difficult or impossible.
Clinical efficacy assessment in photodamaged skin of 0.5% and 1.0% idebenone
Authors: McDaniel DH , Neudecker BA , DiNardo JC , Lewis JA , Maibach HI
Published: September 2005

Idebenone is an antioxidant lower molecular weight analogue of coenzyme Q10. Previously, idebenone was shown to be a very effective antioxidant in its ability to protect against cell damage from oxidative stress in a variety of biochemical, cell biological, and in vivo methods, including its ability to suppress sunburn cell (SBC) formation in living skin. However, no clinical studies have been previously conducted to establish the efficacy of idebenone in a topical skincare formulation for the treatment of photodamaged skin. In this nonvehicle control study, 0.5% and 1.0% idebenone commercial formulations were evaluated in a clinical trial for topical safety and efficacy in photodamaged skin. Forty‐one female subjects, aged 30–65, with moderate photodamaged skin were randomized to use a blind labelled (either 0.5% or 1.0% idebenone in otherwise identical lotion bases) skincare preparation twice daily for six weeks. Blinded expert grader assessments for skin roughness/dryness, fine lines/wrinkles, and global improvement in photodamage were performed at baseline, three weeks and six weeks. Electrical conductance readings for skin surface hydration and 35 mm digital photography were made at baseline after six weeks. Punch biopsies were taken from randomly selected subjects, baseline and after six weeks, and stained for certain antibodies (interleukin IL‐6, interleukin IL‐1b, matrixmetalloproteinase MMP‐1, collagen I) using immunofluorescence microscopy. After six weeks’ use of the 1.0% idebenone formula, a 26% reduction in skin roughness/dryness was observed, a 37% increase in skin hydration, a 29% reduction in fine lines/wrinkles, and a 33% improvement in overall global assessment of photodamaged skin. For the 0.5% idebenone formulation, a 23% reduction in skin roughness/dryness was observed, a 37% increase in skin hydration, a 27% reduction in fine lines/wrinkles, and a 30% improvement in overall global assessment of photodamaged skin. The immunofluorescence staining revealed a decrease in IL‐1b, IL‐6, and MMP‐1 and an increase in collagen I for both concentrations.
Striae distensae in darker skin types: the influence of melanocyte mechanobiology
Authors: Piérard‐Franchimont C , Hermanns J F , Hermanns‐Lê T , Piérard G E
Published: September 2005

Introduction   Striae distensae in White people are commonly described as being reddish at first and turning white in time. This dual perception has been challenged. Indeed, the color difference between striae distensae and their surrounding skin varies on a wide range in part depending upon typology.

Aim   To study striae nigrae that are found only in subjects of darker complexion.

Materials and methods   In the present study conducted in 44 darker skin adults, dermoscopy was combined to reflectance colorimetry.

Results   Striae nigrae exhibited hypermelanosis of the epidermal rete ridges crossing transversally the lesions in a laddering pattern. By contrast, striae albae showed only faint melanotic networks.

Conclusions   As striae distensae are in part under the influence of skin stretching, their colors are likely to be controlled by some mechanobiological process activating or inhibiting melanogenesis in people of darker complexion. No argument involving an inflammatory mechanism is supported by the present observations.
An Investigation of FRAXA Intermediate Allele Phenotype in A Longitudinal Sample
Authors: Ennis S. , Murray A. , Youings S. , Brightwell G. , Herrick D. , Ring S. , Pembrey M. , Morton N. E. , Jacobs P. A. ,   The ALSPAC Study Team
Published: September 2005

The FRAXA trinucleotide repeat at Xq27.3 gives rise to fragile X syndrome when fully expanded, and both premature ovarian failure (POF) and fragile X tremor and ataxia syndrome (FXTAS) when in the premutation range. Reports of phenotypic effects extending into the intermediate repeat range are inconsistent but some studies suggest that these smaller expansions predispose to special educational needs (SEN). This study utilises the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort to investigate cognitive and behavioural variables that might be associated with FRAXA intermediate alleles.

The current study failed to find any strong evidence of association of FRAXA intermediate alleles with SEN, behavioural problems or cognitive difficulties. However, our findings illustrate some of the difficulties encountered in identifying individuals with SEN. The power to identify specific components of cognitive and behavioural difficulties was reduced due to elective drop‐out, which is characteristic of longitudinal studies. Our findings demonstrate the non‐random loss of participants from this cohort and highlight problems that may arise when such data are used in genetic association studies.
Companion planting – behaviour of the cabbage root fly on host plants and non‐host plants
Authors: Morley Kate , Finch Stan , Collier Rosemary H.
Published: September 2005

Six‐hundred individual female cabbage root flies (Delia radicum L.) (Diptera: Anthomyiidae) were each observed for 20 min under laboratory conditions to record how they behaved after landing on a host or a non‐host plant. Fly movements were recorded on host plants [cabbage –Brassica oleracea var. capitata (Cruciferae)] and non‐host plants [clover –Trifolium subterraneum L. (Papilionaceae)] surrounded by bare soil and on cabbage surrounded by clover. The most frequently observed behaviours made by the flies were (1) hops/spiral flights and (2) walks/runs. In the bare soil situation, the 50 individual flies observed in each treatment made 66 hops/spiral flights on the cabbage and 94 on the clover. When the two plants were tested together the movements were not additive as, instead of the expected 160 hops/spiral flights in the mixed plant treatment, the flies made 210 hops/spiral flights when they landed initially on cabbage but only 130 when they landed initially on clover. Few of the flies that landed initially on clover moved onto the host plant, even though the host plant was only a few centimetres away. The duration of the individual walks and runs made by the cabbage root flies were similar on both the host and non‐host plants. The only differences were the numbers of walks/runs made and the time the flies remained inactive. On the host plants, the females made four walks/runs, each of about 12 s duration, interspersed by rest periods that totalled 1.5 min. In contrast, on the non‐host plants the females made 10 walks/runs, each of about 9 s duration, interspersed by rest periods that totalled 7 min. Therefore, after landing on a plant, the flies, on average, left the host plant after 2.25 min and the non‐host plant after 8.5 min. Our conclusion is that the protracted time spent on the non‐host plants is the mechanism that disrupts insects from finding host plants in diverse plantings. Hence, the flies were arrested by non‐host plants rather than being repelled or deterred as suggested in earlier studies.
Maternal effects increase survival probability in Drosophila subobscura larvae
Authors: Rohlfs Marko , Hoffmeister Thomas S.
Published: September 2005

Drosophilid flies breeding on ephemeral resource patches (e.g., decaying fruits) are assumed to transfer yeasts to their oviposition sites, presumably in order to positively affect offspring development. We tested this hypothesis with Drosophila subobscura Collin (Diptera: Drosophilidae) by manipulating their nutritional (yeast‐fed vs. non‐yeast‐fed) and reproductive status (mated vs. non‐mated). Flies were then released into vials containing decaying fruits (either sloes, crab apples, or Syrian plums). After a constant residence time in the vials, the flies were removed, 16 first‐instar larvae were transferred to the fruits and their survival probability to the adult stage was recorded. Whereas previous exposure of the larval substrate to yeast‐fed males and virgin females (yeast‐fed and non‐yeast‐fed) had no effect on survivorship, exposure to yeast‐fed and mated females that deposited eggs on the fruits (subsequently removed) led to a significant increase in the survival probability of the transferred larvae to the adult stage. Although the exact mechanism of yeast transmission remains to be determined, we suggest an active inoculation of the breeding substrates with yeast by ovipositing females. In agreement with previous studies, we found a negative effect of mould growth on larval survival, which, however, depended on the fruit type. We discuss various scenarios of yeast involvement in benefits to the insect larvae and suggest that insect–mould interactions should be examined in detail in order to better understand the behavioural and life‐history traits of insects that depend on ephemeral resources.
In vitro cultivation of parthenogenesis‐inducing Wolbachia in an Aedes albopictus cell line
Authors: Kubota Masako , Morii Tomohiro , Miura Kazuki
Published: September 2005

Parthenogenesis‐inducing (PI) Wolbachia, infecting the parasitoid wasp Trichogramma kaykai Pinto and Stouthamer (Hymenoptera: Trichogrammatidae), were successfully maintained and cultivated in a mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), cell line, NIAS‐AeAl‐2. A parthenogenesis‐inducing (PI) Wolbachia strains with wasp ovaries were introduced into flasks with cultures of the cell line. The PI Wolbachia proliferated in NIAS‐AeAl‐2 as confirmed using a quantitative polymerase chain reaction method. Our final goal is to induce parthenogenesis in other hymenopteran species of commercial interest through the artificial transfer of PI Wolbachia. As a step towards this goal, we microinjected pupae of Trichogramma with PI Wolbachia culture in NIAS‐AeAl‐2 cells and PI Wolbachia was detected from recipient by PCR with Wolbachia specific primers (wsp gene).
β‐eudesmol‐induced aggression in the leaf‐cutting ant Atta sexdens rubropilosa
Authors: Marinho C. G. S. , Della Lucia T. M. C. , Guedes R. N. C. , Ribeiro M. M. R. , Lima E. R.
Published: September 2005

Leaf‐cutting ants are highly polyphagous insects, but some plants escape their attack due to the presence of secondary metabolites that are toxic to the ant–fungus symbiosis. Previous studies have demonstrated that the terpenoid β‐eudesmol extracted from Eucalyptus species (Myrtaceae) is responsible for the deleterious behavior in colonies of leaf‐cutting ant species. The objective of this study was to evaluate the effect of β‐eudesmol on workers of the leaf‐cutting ant Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae). This chemical caused behavioral modification in the colonies, leading to mutilation and death of workers. It is suggested that β‐eudesmol interferes with colony nestmate recognition. As a consequence, colony cohesion may be disrupted by β‐eudesmol what could be used as an additional control tactic against this important pest ant.
Structural and morphometrical study in glandular parenchyma from alcoholic sialosis
Authors: Carranza M. , Ferraris M. E. , Galizzi M.
Published: September 2005

Background:  The aim of this work was to determine morphometrical changes in lingual, labial and submaxillar salivary glands from alcoholic chronics.

Methods:  Five samples of each type of gland were obtained from autopsies of chronic alcoholics and equal number of samples from individuals whose death cause was accidental (controls). Serous acini in von Ebner and submaxillar glands and mucous acini in labial and Blandin–Nühn glands were analysed. In the ductal system, intra and interlobular striated ducts were studied. A digital‐image analyser was used to measure different parameters in the acini and ducts.

Results:  Statistical analysis revealed that lingual and submaxillar salivary glands presented a significant acinar hypertrophy and hyperplasy. These changes were not observed in labial salivary glands. All studied glands showed significant structural modifications in the striated ducts.

Conclusion:  These results indicate that the significant variations together with the histological qualitative pattern could be useful as confident indicators for the differential histopathological diagnosis with other sialosis from different aetiology.
Risk factors associated with denture stomatitis in the United States
Authors: Shulman J. D. , Rivera‐Hidalgo F. , Beach M. M.
Published: September 2005

Background:  This study reports denture stomatitis (DS) prevalence from a large USA probability sample from the National Health and Nutrition Examination Survey, 1988–1994 (NHANES III).

Methods:  Oral examinations were performed on 3450 individuals 18–90+ years of age (mean: 59.2; SD: 0.50 years), 57.7% male and 42.3% female. Multivariable logistic regression models were fitted for DS using sociodemographic, denture quality, blood analytes, alcohol and tobacco use, history of diabetes, and current antibiotic use as covariates. Odds ratios (OR), adjusted for other covariates in each model (AOR) are presented.

Results:  Of 3450 removable denture wearers, 963 (27.9%) had DS. DS prevalence was associated with wearing maxillary (AOR: 6.20) and mandibular (AOR: 5.21) complete dentures continuously; smoking ≥15 cigarettes day (maxillary complete: AOR = 1.31; mandibular complete: AOR = 1.50; maxillary partial: AOR = 2.04); vitamin A deficiency (mandibular complete: AOR = 5.97; maxillary partial: AOR = 5.67; mandibular partial: AOR = 24.42). Maxillary dentures with inadequate relines had approximately half the OR of DS than those with adequate relines (maxillary complete: AOR = 0.42; mandibular complete: AOR = 0.50).

Conclusions:  Denture stomatitis prevalence is associated with the amount of tissue covered by dentures, low vitamin A levels, cigarette smoking, and constant denture wear.
Tumor necrosis factor‐α increases chemokine gene expression and production in synovial fibroblasts from human temporomandibular joint
Authors: Ogura Naomi , Tobe Makiko , Sakamaki Hiroyuki , Nagura Hideaki , Abiko Yoshimitsu , Kondoh Toshirou
Published: September 2005

Background:  Synovitis, which is characterized by infiltration of inflammatory cells, often accompanies progression of clinical symptoms of the temporomandibular joint (TMJ). Synovial fibroblasts of the TMJ are believed to play important roles in progression of synovitis. The purpose of this study was to examine production and gene expression of chemokines by synovial fibroblasts stimulated by tumor necrosis factor‐α (TNF‐α).

Methods:  Protein levels of chemokines were measured by enzyme‐linked immunosorbent assay (ELISA). Gene expression of chemokines was analyzed by real‐time polymerase chain reaction (PCR).

Results:  Production of interleukin (IL)‐8, growth‐related oncogene (GRO)‐α, monocyte chemoattractant protein (MCP)‐1, and regulated upon activation normal T‐cell expressed and secreted (RANTES) protein by synovial fibroblasts was increased by TNF‐α. In contrast, stromal cell‐derived factor (SDF)‐1α, macrophage inflammatory protein (MIP)‐1α and ‐1β were not detectable in conditioned media of synovial fibroblasts, with or without TNF‐α treatment. Increases in gene expression of IL‐8, GRO‐α, MCP‐1, and RANTES in response to TNF‐α treatment were detected.

Conclusions:  Increased protein production and gene expression of chemokines by synovial fibroblasts in response to TNF‐α treatment appears to play an important role in recruitment of inflammatory cells into synovium and the progression of synovitis in the TMJ.
Cystic lesion of the parotid following drug‐induced toxic epidermal necrolysis (Lyell's syndrome)
Authors: Paquet P. , Jacob E. , Piérard G. E.
Published: September 2005

A 32‐year‐old woman developed a unilateral cyst of the duct of parotid gland 4 months after severe oral involvement of drug‐induced toxic epidermal necrolysis (TEN). The pathomechanism leading to the TEN epidermal destruction had presumably involved the salivary epithelium as well, leading to the development of the cystic lesion. The patient had low serum lipase levels, but high serum amylase levels at the time of TEN. These serological markers could represent a clue for the risk of developing cystic lesions of the large salivary glands following TEN.