The role of cytokines and hot flashes in perimenopausal depression

<p>Abstract</p> <p>Background</p> <p>An imbalance in the production of proinflammatory and anti-inflammatory cytokines may play a role in the pathophysiology of perimenopausal depression. The aim of this study was to examine serum levels of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNFα), and the anti-inflammatory cytokine IL-10, in perimenopausal women suffering from depression. Furthermore, to assess whether serum cytokine levels are associated with the presence of hot flashes or the use of selective serotonin reuptake inhibitors (SSRIs). We also evaluated the possible association of hot flashes and perimenopausal depression.</p> <p>Methods</p> <p>Serum samples from 65 perimenopausal women, 41 with depression and 24 without depression, were assessed for serum IL-6, TNFα and IL-10 by conventional enzyme-linked immunosorbent assays. Depression was evaluated by the 17-item Hamilton Depression Rating Scale (HAM-D 17) and a psychiatric interview. The presence and severity of hot flashes were examined using the Menopause Rating Scale (MRS).</p> <p>Results</p> <p>Serum levels cytokines did not differ between depressed women and normal controls. Serum levels of cytokines did not change significantly in depressed women with hot flashes or in depressed women treated with SSRIs. Hot flashes were strongly associated (<it>P </it>< 0.0001) with perimenopausal depression.</p> <p>Conclusion</p> <p>The study supports the hypothesis that perimenopausal depression is not characterized by increased proinflammatory cytokines and decreased anti-inflammatory cytokines. Women with perimenopausal depression suffer from more severe and more frequent hot flashes than women without perimenopausal depression.</p

Mobilisation of arsenic from bauxite residue (red mud) affected soils: effect of pH and redox conditions

The tailings dam breach at the Ajka alumina plant, western Hungary in 2010 introduced ~1 million m3 of red mud suspension into the surrounding area. Red mud (fine fraction bauxite residue) has a characteristically alkaline pH and contains several potentially toxic elements, including arsenic. Aerobic and anaerobic batch experiments were prepared using soils from near Ajka in order to investigate the effects of red mud addition on soil biogeochemistry and arsenic mobility in soil–water experiments representative of land affected by the red mud spill. XAS analysis showed that As was present in the red mud as As(V) in the form of arsenate. The remobilisation of red mud associated arsenate was highly pH dependent and the addition of phosphate to red mud suspensions greatly enhanced As release to solution. In aerobic batch experiments, where red mud was mixed with soils, As release to solution was highly dependent on pH. Carbonation of these alkaline solutions by dissolution of atmospheric CO2 reduced pH, which resulted in a decrease of aqueous As concentrations over time. However, this did not result in complete removal of aqueous As in any of the experiments. Carbonation did not occur in anaerobic experiments and pH remained high. Aqueous As concentrations initially increased in all the anaerobic red mud amended experiments, and then remained relatively constant as the systems became more reducing, both XANES and HPLC–ICP-MS showed that no As reduction processes occurred and that only As(V) species were present. These experiments show that there is the potential for increased As mobility in soil–water systems affected by red mud addition under both aerobic and anaerobic conditions

Microbially mediated reduction of FeIII and AsV in Cambodian sediments amended with 13C-labelled hexadecane and kerogen

Microbial activity is generally accepted to play a critical role, with the aid of suitable organic carbon substrates, in the mobilisation of arsenic from sediments into shallow reducing groundwaters. The nature of the organic matter in natural aquifers driving the reduction of AsV to AsIII is of particular importance but is poorly understood. In this study, sediments from an arsenic rich aquifer in Cambodia were amended with two 13C-labelled organic substrates. 13C-hexadecane was used as a model for potentially bioavailable long chain n-alkanes and a 13C-kerogen analogue as a proxy for non-extractable organic matter. During anaerobic incubation for 8 weeks, significant FeIII reduction and AsIII mobilisation were observed in the biotic microcosms only, suggesting that these processes were microbially driven. Microcosms amended with 13C-hexadecane exhibited a similar extent of FeIII reduction to the non-amended microcosms, but marginally higher AsIII release. Moreover, gas chromatography–mass spectrometry analysis showed that 65 % of the added 13C-hexadecane was degraded during the 8-week incubation. The degradation of 13C-hexadecane was microbially driven, as confirmed by DNA stable isotope probing (DNA-SIP). Amendment with 13C-kerogen did not enhance FeIII reduction or AsIII mobilisation, and microbial degradation of kerogen could not be confirmed conclusively by DNA-SIP fractionation or 13C incorporation in the phospholipid fatty acids. These data are, therefore, consistent with the utilisation of long chain n-alkanes (but not kerogen) as electron donors for anaerobic processes, potentially including FeIII and AsV reduction in the subsurface

Biomarker-indicated extent of oxidation of plant-derived organic carbon (OC) in relation to geomorphology in an arsenic contaminated Holocene aquifer, Cambodia

The poisoning of rural populations in South and Southeast Asia due to high groundwater arsenic concentrations is one of the world’s largest ongoing natural disasters. It is important to consider environmental processes related to the release of geogenic arsenic, including geomorphological and organic geochemical processes. Arsenic is released from sediments when iron-oxide minerals, onto which arsenic is adsorbed or incorporated, react with organic carbon (OC) and the OC is oxidised. In this study we build a new geomorphological framework for Kandal Province, a highly studied arsenic affected region of Cambodia, and tie this into wider regional environmental change throughout the Holocene. Analyses shows that the concentration of OC in the sediments is strongly inversely correlated to grainsize. Furthermore, the type of OC is also related to grain size with the clay containing mostly (immature) plant derived OC and sand containing mostly thermally mature derived OC. Finally, analyses indicate that within the plant derived OC relative oxidation is strongly grouped by stratigraphy with the older bound OC more oxidised than younger OC

Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue

Highly reactive nano-scale biogenic magnetite (BnM), synthesized by the Fe(III)-reducing bacterium Geobacter sulfurreducens, was tested for the potential to remediate alkaline Cr(VI) contaminated waters associated with chromite ore processing residue (COPR). The performance of this biomaterial, targeting aqueous Cr(VI) removal, was compared to a synthetic alternative, nano-scale zero valent iron (nZVI). Samples of highly contaminated alkaline groundwater and COPR solid waste were obtained from a contaminated site in Glasgow, UK. During batch reactivity tests, Cr(VI) removal from groundwater was inhibited by ~25% (BnM) and ~50% (nZVI) when compared to the treatment of less chemically complex model pH 12 Cr(VI) solutions. In both the model Cr(VI) solutions and contaminated groundwater experiments the surface of the nanoparticles became passivated, preventing complete coupling of their available electrons to Cr(VI) reduction. To investigate this process, the surfaces of the reacted samples were analyzed by TEM-EDX, XAS and XPS, confirming Cr(VI) reduction to the less soluble Cr(III) on the nanoparticle surface. In groundwater reacted samples the presence of Ca, Si and S was also noted on the surface of the nanoparticles, and is likely responsible for earlier onset of passivation. Treatment of the solid COPR material in contact with water, by addition of increasing weight % of the nanoparticles, resulted in a decrease in aqueous Cr(VI) concentrations to below detection limits, via the addition of ≥5% w/w BnM or ≥1% w/w nZVI. XANES analysis of the Cr K edge, showed that the % Cr(VI) in the COPR dropped from 26% to a minimum of 4-7% by the addition of 5% w/w BnM or 2% w/w nZVI, with higher additions unable to reduce the remaining Cr(VI). The treated materials exhibited minimal re-mobilization of soluble Cr(VI) by re-equilibration with atmospheric oxygen, with the bulk of the Cr remaining in the solid fraction. Both nanoparticles exhibited a considerable capacity for the remediation of COPR related Cr(VI) contamination, with the synthetic nZVI demonstrating greater reactivity than the BnM. However, the biosynthesized BnM was also capable of significant Cr(VI) reduction and demonstrated a greater efficiency for the coupling of its electrons towards Cr(VI) reduction than the nZVI

The potential impact of anaerobic microbial metabolism during the geological disposal of intermediate-level waste.

AbstractMicrobial metabolism has the potential to control the biogeochemistry of redox-active radionuclides in a range of geodisposal scenarios. In this study, sediments from a high pH lime workings site were incubated under carefully controlled anaerobic conditions, at a range of alkali pH values with added electron donors and electron acceptors, to explore the limits and rates of bioreduction in a sediment system analogous to intermediate-level nuclear waste. There was a clear succession in the utilization of electron acceptors (in the order nitrate &gt; Fe(III)-citrate &gt; Fe(III) oxyhydroxide &gt; sulfate), in accordance with calculated free energy yields and Eh values over the pH range 10–12. The rate and extent of bioreduction decreased at higher pH, with an upper limit for the processes studied at pH 12. The biochemical limits for such processes are discussed, alongside the potential impact of such forms of microbial metabolism on the solubility of a range of redox active radionuclides that will feature heavily in the safety case for the geological disposal of intermediate-level nuclear waste.</jats:p

Serum Leptin Levels in Patients with Alzheimer’s Disease

Introduction: Leptin receptors have been identified in many peripheral tissues as well as the CNS including thehippocampus, which is particularly vulnerable in Alzheimer’s disease (AD). Animal data shows that leptin may beimplicated in the pathophysiology of AD. The aim of this study was to examine if there is any differences in serumleptin levels between patients with AD and normal controls.Material and methods: Ninety patients with AD and 95 normal controls matched for age and gender wereincluded. The diagnosis of Alzheimer dementia was based on standard criteria provided by the ICD-10 system.Blood samples were frozen at -80oC until analysis. Leptin levels were measured using a human leptin enzymelinked immunosorbent assay (ELISA) kit.Differences in leptin levels were assessed between the two groups using the Mann–Whitney method. Linearregression analysis was also used to adjust for characteristics shown to be associated with leptin and cognitivedecline.Results: From the patients with AD, 74 were women and 16 were men (mean age 80.53±6.03, mean body weight71.49±8.33) and from the control group 78 were women and 17 men (mean age 79.27±6.86, mean body weight70.23±6.73). Linear regression revealed that the use of antipsychotic drugs was associated with serum levels ofleptin (p<0.001). Serum leptin levels were, also, significantly lower in patients with AD compared to normalcontrols (17.89±23.59 in AD patients vs 26.82±17.77 in normal controls, p<0.0001, Mann-Whitney U).Conclusion: Our study, in accordance with the findings of studies in animal models, provides evidence that leptinmay be implicated in the pathophysiology of AD