Mineralogical, geochemical, and geotechnical features of lateritic soils from termite mounds in two contrasting savannah areas (central Cameroon) as raw materials for brick making.

Termite mound soils (TMS) from humid savannah (HS) and dry savannah (DS) were evaluated as raw materials for compressed earth bricks (CEB) and fired bricks. Mineralogy and major elements geochemistry were performed by X-Ray Diffraction and X-Ray Fluorescence, respectively. Physico-mechanical characteristics of unfired and fired bricks at 900, 950, 1000, 1050, and 1100 °C after 7 curing days were evaluated. The studied TMS are made up of quartz, muscovite, anatase, kaolinite, hematite, and goethite. Illite is present in humid savannah while in DS gibbsite appears. These materials are rich in SiO2 (58.96-61.79 wt%), Al2O3 (16.93-18.78 wt%), and Fe2O3 (7.41-10.33 wt%). The TMS from both HS and DS are sandy clay. Those from DS are silty (13%) than those from HS (<5.7%). Termite mound materials in DS are moderately plastic, while those in HS are highly plastic. Flexural strength values vary between 2.20 and 2.38 MPa for unfired bricks and between 2.41 and 3.26 MPa for fired bricks, respectively at 1100 and 1050 °C. Compressive strength values are ranged from 2.01 to 3.50 MPa for unfired bricks and 2.44 (1100 °C) to 11.08 MPa (1050 °C), with the best values in the DS area. Water absorption and linear shrinkage values are less than 25% and 5%, respectively, in the studied fired and unfired bricks. The physical and mechanical properties of unfired and fired bricks show that the studied TMS can be used for dense brick manufacturing. Materials from dry savannah exhibit better characteristics as construction materials due to relatively high weathering intensity leading to a spread-out particle size distribution, sintering, which promotes densification by reducing the porosity, and the conversion of metakaolinite into primary mullite upon temperature increase.

Risk assessment of trace metals in Mefou River sediments, West-Africa.

This study focuses on risk assessment of Cr, V, Ni, Co, Pb, Cu, and Zn in the Mefou River sediments located at Yaoundé, West-Africa. Sediment samples were collected from five stations in the downstream of the Mefou River, which drains the urban area of Yaoundé between latitudes 3°30' and 3°58' North and longitudes 11°20' and 11°40' East. The geochemistry data were analyzed statistically and the pollution indices were calculated in order to identify and estimate the sources of metal contamination in the Mefou River sediments. The results obtained show that the average concentrations of trace metals are almost higher than those of the upper continental crust (UCC) and the metal average in the Simbock Lake cores. However, the concentrations of Ni, Cu, Pb, and Zn in sediments located in most urbanized sites are lower than those of the UCC and the average of Simbock Lake sediments. The pollution indices such as enrichment factor (EF), geo-accumulation index (Igeo), and pollution load index (PLI) showed that trace metals were mainly influenced by human sources, except for Pb, Cu, and Zn, which stemmed from natural sources. The sediments of the Mefou River would therefore be affected with low to moderate pollution levels. The low values of potential ecological risk (RI: 22.36-41.53) suggest a low potential ecological risk effect. The multivariate statistical analysis indicates that Ni, Cu, Pb, Co, and Zn have been derived mainly from natural sources, while V and Cr would partially derive from human activities. The results of this research can be a reference for trace metal pollution along an African urbanized river corridor. This can be considered as an act of prevention of urban watercourses in Cameroon and in other parts of the world, especially in major African urban metropolis.

Correction: Brain region-specific alterations of RNA editing in PDE8A mRNA in suicide decedents.

Author forgot to attach a supplementary doc file which includes the supplementary methods and supplementary figure legends.

Brain region-specific alterations of RNA editing in PDE8A mRNA in suicide decedents.

Phosphodiesterases (PDE) are key modulators of signal transduction and are involved in inflammatory cell activation, memory and cognition. There is a two-fold decrease in the expression of phosphodiesterase 8A (PDE8A) in the temporal cortex of major depressive disorder (MDD) patients. Here, we studied PDE8A mRNA-editing profile in two architectonically distinct neocortical regions in a clinically well-characterized cohort of age- and sex-matched non-psychiatric drug-free controls and depressed suicide decedents. By using capillary electrophoresis single-stranded conformational polymorphism (CE-SSCP), a previously validated technique to identify A-to-I RNA modifications, we report the full editing profile of PDE8A in the brain, including identification of two novel editing sites. Editing of PDE8A mRNA displayed clear regional difference when comparing dorsolateral prefrontal cortex (BA9) and anterior cingulate cortex (BA24). Furthermore, we report significant intra-regional differences between non-psychiatric control individuals and depressed suicide decedents, which could discriminate the two populations. Taken together, our results (i) highlight the importance of immune/inflammatory markers in major depressive disorder and suicide and (ii) establish a direct relationship between A-to-I RNA modifications of peripheral markers and A-to-I RNA editing-related modifications in brain. This work provides the first immune response-related brain marker for suicide and could pave the way for the identification of a blood-based biomarker that predicts suicidal behavior.

In vitro screening for drug-induced depression and/or suicidal adverse effects: a new toxicogenomic assay based on CE-SSCP analysis of HTR2C mRNA editing in SH-SY5Y cells.

Many drugs in clinical trials, or already on the market, can have psychiatric side effects, independently of their therapeutic indication (e.g., Acomplia, Taranabant, and Roaccutane). There is currently no in vitro or in vivo approved test for the detection/prediction of such adverse effects, and the Food and Drugs Administration (FDA) can only issue general alerts on specific therapeutic classes. The development of a screening assay is therefore of real interest. The anti-viral and anti-tumor action of human interferon-alpha (hIFNα) is associated with a variety of neuropsychiatric side effects, including major depression, suicidal ideation and suicide. RNA editing of the serotonin 2C receptor (HTR2C) by adenosine deaminases acting on RNA (ADARs) is a post-transcriptional modification, the regulation of which is altered in depressed suicide victims. In this study, we show that in the SH-SY5Y neuroblastoma cell line, hIFNα specifically activates the ADAR1a isoform and thereby modifies the HTR2C mRNA editing profile. As this hIFNα-induced altered profile partly overlaps with that observed in the brain of depressed suicide victims, we investigated whether it could be used as a signature to identify drugs with depression and/or suicidal side effects. By means of the Biocortech proprietary screening assay, which allows the relative quantification of all the edited HTR2C isoforms in a sample, we blind-tested the effect of 50 marketed molecules on HTR2C mRNA editing in SH-SY5Y cells and identified 17 compounds with an IFN-like editing profile. This new toxicogenomic assay can identify compounds with potential psychiatric adverse events with a positive predictive value of 90 %.

[Tongue necrosis under corticosteroids]. / Nécrose de langue sous corticoïdes.

INTRODUCTION: The tongue is a common location for Horton necrotic injuries. But some herpetic lesions can show similar symptoms to the disease and complicate the diagnosis. CASE REPORT: A 67-year-old woman, treated by corticosteroids for Horton disease, presented a central, deep, and very painful ulceration of the tongue. The spreading of necrosis despite treatment was an indication for biopsy, giving the diagnosis of herpetic infection. Valacyclovir was efficient within 15 days. DISCUSSION: This necrotic injury looks like herpetic stomatitis presented by severely immunodeficient AIDS patients. No case under corticosteroids had been described so far. The tongue-limited location is exceptional.

Inverse agonist and neutral antagonist actions of antidepressants at recombinant and native 5-hydroxytryptamine2C receptors: differential modulation of cell surface expression and signal transduction.

Despite the importance of 5-hydroxytryptamine (5-HT)(2C) (serotonin) receptors in the control of depressive states, actions of antidepressants at these receptors remain poorly characterized. This issue was addressed both in human embryonic kidney (HEK)-293 cells coexpressing unedited human 5-HT(2CINI) receptors and Galpha(q) protein and in cultured mouse cortical neurons. Indicative of constitutive activity, the inverse agonist SB206,553 decreased basal inositol phosphate (IP) production in HEK-293 cells. The tetracyclic antidepressants mirtazapine and mianserin likewise suppressed basal IP formation. Conversely, the tricyclics amitriptyline and clomipramine, the m-chlorophenylpiperazine derivatives trazodone and nefazodone, and the 5-HT reuptake inhibitors fluoxetine and citalopram were inactive alone, although they blocked 5-HT-induced IP production. Inverse agonist actions of 5-methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2,3-f]indole (SB206,553) and mirtazapine were abolished by the neutral antagonist 6-chloro-5-methyl-1-[6-(2-methylpyridin-3-yloxy)pyridin-3-ylcarbamoyl]indoline (SB242,084), which was inactive alone. As assessed by confocal microscopy and enzyme-linked immunosorbent assay, prolonged treatment of HEK-293 cells with SB206,553, mirtazapine, or mianserin, but not the other antidepressants, enhanced cell surface expression of 5-HT(2C) receptors: 5-HT-induced IP production was also increased, and both these actions were blocked by SB242,084. Cortical neurons were shown by reverse transcription-polymerase chain reaction to predominantly express constitutively active 5-HT(2C) receptor isoforms. Prolonged pretreatment with SB206,553 or mirtazapine triggered an otherwise absent 5-HT-induced elevation in cytosolic Ca(2+) concentrations. SB242,084, which was inactive alone, abolished these effects of SB206,553 and mirtazapine. In conclusion, the tetracyclic antidepressants mirtazapine and mianserin, but not other clinically established antidepressants, suppress constitutive activity at recombinant and native 5-HT(2C) receptors. The clinical significance of inverse agonist versus neutral antagonist properties both during and after drug administration will be of interest to elucidate.

Identification and relative quantification of adenosine to inosine editing in serotonin 2c receptor mRNA by CE.

A new method has been developed allowing the identification and relative quantification of different forms of mRNA after RNA editing. This method was applied to the serotonin 2c receptor mRNA that potentially exhibits 32 different forms after adenosine to inosine editing at five different sites located in a row of 13 nucleotides. CE was used to characterize fluorescently labeled ssDNA molecules on the basis of their conformational polymorphism. The relative amount of these 32 mRNA forms has been estimated by measuring the fluorescence intensity of each individual DNA strand. Accuracy of quantification was established by diluting one form into another or into a mixture of cDNA, showing linear and precise proportion of each form (0.06