Bioremediation of Crude Oil–Contaminated Soil By Immobilized Bacteria on an Agroindustrial Waste—Sunflower Seed Husks

This study reports the immobilization and performance of a hydrocarbon-degrading Rhodococcus sp. strain (designated as QBTo) on sunflower seed husks (SH) for the bioremediation of soils polluted with crude oil. The SH performance as inoculants carrier was compared with peat, which is a vegetal material traditionally used in carrier-based inoculants production. The stability of the immobilized culture under storage conditions was assessed by viability at different times when stored at 25°C and 10°C. The catabolic activity of immobilized and free QTBo cells introduced into sandy loam soil, freshly contaminated with crude oil, was studied in microcosms. A higher number of viable QTBo cells were recovered from the inoculants formulated with SH (QTBo-SH) after prolonged storage at 10°C and 25°C. The microcosms amended with QTBo-SH inoculants showed a removal of about 66% of total petroleum hydrocarbons (TPH), whereas in those inoculated with QTBo-peat inoculants, the decrease was of about 47%. In the control microcosms (noninoculated) and liquid culture–amended soils, the TPH removal was about 28%. SH is a waste of edible oil industry, nontoxic, and biodegradable and has demonstrated to confer to the immobilized cultures greater potential to survive not only during storage but also in the soil environment, improving bioremediation process.     

Conservation genetics of two island endemic Ribes spp. (Grossulariaceae) of Sardinia: survival or extinction?

Measuring levels of population genetic diversity is an important step for assessing the conservation status of rare or endangered plant species and implementing appropriate conservation strategies. Populations of Ribes multiflorum subsp. sandalioticum and R. sardoum, two endangered endemic species from Sardinia, representing the whole genus on the island, were investigated using ISSR and SSR markers to determine levels and structure of genetic variability in their natural populations. Results indicated medium to low genetic diversity at the population level: Nei's gene diversity for ISSR markers ranged from 0.0840 to 0.1316; the expected heterozygosity (H_E) for SSR ranged from 0.4281 to 0.7012. In addition, only one remnant population of R. sardoum showed a high level of inbreeding, in accordance with its very small size. Regarding the structure of the six R. sandalioticum populations, both principal coordinates analysis (PCoA) and STRUCTURE analysis of ISSR and SSR data highlighted low population structure, although two populations appeared to be clearly distinct from the others. The genetic pattern of the two taxa associated with their different ecological positions indicated resilience of R. sandalioticum populations in fresh and humid habitats and uncertain future resistance for the residual R. sardoum population in xeric calcareous stands. Hence, this study highlights the importance of an integrated conservation approach (genetic plus in situ and ex situ conservation studies/measures) for activating management programmes in these endemic and threatened taxa that can be considered as crop wild relatives of cultivated Ribes species.     

Increased cardenolides production by elicitation of Digitalis lanata shoots cultured in temporary immersion systems

Digitalis lanata is an important source of cardenolides such as digoxin and lanatoside C, which have been widely applied in the treatment of cardiac insufficiencies. Elicitation is one of the most effective methods to enhance the biosynthesis of several secondary metabolites in medicinal plants. We studied the effect of elicitation with Chitoplant^?, Silioplant^? and methyl jasmonate on biomass and cardenolides accumulation in shoots of D. lanata cultivated in temporary immersion systems. Morphological response of the shoots was influenced by elicitors. A reduction in length and number of shoots was evident with all MJ concentrations. Regarding biomass production, Chitoplant^? (0.1?g?l^?1) was found to impact significantly on fresh and dry weight of the shoots. HPLC analysis revealed a higher content of lanatoside C compared to digoxin in all treatments. The highest accumulation of lanatoside C was achieved with Chitoplant^? (0.1?g?l^?1), which resulted in 316???g?g-DW^?1 and with Silioplant^? (0.01?g?l^?1; 310???g?g-DW^?1), which accounted for a 2.2-fold increase in lanatoside C content compared to non-elicited shoot cultures. Additionally, elicitation of D. lanata shoots in temporary immersion systems resulted in an oxidative stress characterized by hydrogen peroxide and malondialdehyde accumulation. These observations point to a connection between hydrogen peroxide generation, lipid peroxidation and cardenolide accumulation. The optimization of elicitor treatment and culture conditions for cardenolide production as well as the advantages of TIS for this purpose are discussed.     

Effects of phosphorus and nitrogen on nodulation are seen already at the stage of early cortical cell divisions in Alnus incana

BACKGROUND AND AIMS: The present work aimed to study early stages of nodulation in a chronological sequence and to study phosphorus and nitrogen effects on early stages of nodulation in Alnus incana infected by Frankia. A method was developed to quantify early nodulation stages in intact root systems in the root hair-infected actinorhizal plant A. incana. Plant tissue responses were followed every 2 d until 14 d after inoculation. Cortical cell divisions were already seen 2 d after inoculation with Frankia. Cortical cell division areas, prenodules, nodule primordia and emerging nodules were quantified as host responses to infection. METHODS: Seedlings were grown in pouches and received different levels of phosphorus and nitrogen. Four levels of phosphorus (from 0.03 to 1 mM P) and two levels of nitrogen (0.71 and 6.45 mM N) were used to study P and N effects on these early stages of nodule development. KEY RESULTS: P at a medium concentration (0.1 mM) stimulated cell divisions in the cortex and a number of prenodules, nodule primordia and emerging nodules as compared with higher or lower P levels. A high N level inhibited early cell divisions in the cortex, and this was particularly evident when the length of cell division areas and presence of the nodulation stages were related to root length. CONCLUSIONS: Extended cortical cell division areas were found that have not been previously shown in A. incana. The results show that effects of P and N are already expressed at the stage when the first cortical cell divisions are induced by Frankia.     

Serum S100A6 Concentration Predicts Peritoneal Tumor Burden in Mice with Epithelial Ovarian Cancer and Is Associated with Advanced Stage in Patients

Background

Ovarian cancer is the 5th leading cause of cancer related deaths in women. Five-year survival rates for early stage disease are greater than 94%, however most women are diagnosed in advanced stage with 5 year survival less than 28%. Improved means for early detection and reliable patient monitoring are needed to increase survival.

Methodology and Principal Findings

Applying mass spectrometry-based proteomics, we sought to elucidate an unanswered biomarker research question regarding ability to determine tumor burden detectable by an ovarian cancer biomarker protein emanating directly from the tumor cells. Since aggressive serous epithelial ovarian cancers account for most mortality, a xenograft model using human SKOV-3 serous ovarian cancer cells was established to model progression to disseminated carcinomatosis. Using a method for low molecular weight protein enrichment, followed by liquid chromatography and mass spectrometry analysis, a human-specific peptide sequence of S100A6 was identified in sera from mice with advanced-stage experimental ovarian carcinoma. S100A6 expression was documented in cancer xenografts as well as from ovarian cancer patient tissues. Longitudinal study revealed that serum S100A6 concentration is directly related to tumor burden predictions from an inverse regression calibration analysis of data obtained from a detergent-supplemented antigen capture immunoassay and whole-animal bioluminescent optical imaging. The result from the animal model was confirmed in human clinical material as S100A6 was found to be significantly elevated in the sera from women with advanced stage ovarian cancer compared to those with early stage disease.

Conclusions

S100A6 is expressed in ovarian and other cancer tissues, but has not been documented previously in ovarian cancer disease sera. S100A6 is found in serum in concentrations that correlate with experimental tumor burden and with clinical disease stage. The data signify that S100A6 may prove useful in detecting and/or monitoring ovarian cancer, when used in concert with other biomarkers.     

Ceramide-induced activation of cytosolic NADH/cytochrome c electron transport pathway: An additional source of energy for apoptosis

We have investigated whether increase in the oxidation rate of exogenous cytochrome c (cyto-c), induced by long-chain ceramides, might be due to an increased rate of cytosolic NADH/cyto-c electron transport pathway. This process was identified in isolated liver mitochondria and has been studied in our laboratory for many years. Data from highly specific test of sulfite oxidase prove that exogenous cyto-c both in the absence and presence of ceramide cannot permeate through the mitochondrial outer membrane. However, the oxidation of added NADH, mediated by exogenous cyto-c and coupled to the generation of a membrane potential supporting the ATP synthesis, can also be stimulated by ceramide. The results obtained suggest that ceramide molecules, by increasing mitochondrial permeability, with the generation of either raft-like platforms or channels, may have a dual function. They can promote the release of endogenous cyto-c and activate, with an energy conserving process, the oxidation of cytosolic NADH either inducing the formation of new respiratory contact sites or increasing the frequency of the pre-existing porin contact sites. In agreement with the data in the literature, an increase of mitochondrial ceramide molecules level may represent an efficient strategy to activate and support the correct execution of apoptotic program.     

Cancer hallmarks in induced pluripotent cells: New insights

Studies are beginning to emerge that demonstrate intriguing differences between human‐induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs). Here, we investigated the expression of key members of the Nodal embryonic signaling pathway, critical to the maintenance of pluripotency in hESCs. Western blot and real‐time RT‐PCR analyses reveal slightly lower levels of Nodal (a TGF‐β family member) and Cripto‐1 (Nodal's co‐receptor) and a dramatic decrease in Lefty (Nodal's inhibitor and TGF‐β family member) in hiPSCs compared with hESCs. The noteworthy drop in hiPSC's Lefty expression correlated with an increase in the methylation of Lefty B CpG island. Based on these findings, we addressed a more fundamental question related to the consequences of epigenetically reprogramming hiPSCs, especially with respect to maintaining a stable ESC phenotype. A global comparative analysis of 365 microRNAs (miRs) in two hiPSC versus four hESC lines ultimately identified 10 highly expressed miRs in hiPCSs with >10‐fold difference, which have been shown to be cancer related. These data demonstrate cancer hallmarks expressed by hiPSCs, which will require further assessment for their impact on future therapies. J. Cell. Physiol. 225: 390–393, 2010. © 2010 Wiley‐Liss, Inc.     

Altered effective connectivity network of the amygdala in social anxiety disorder: a resting-state FMRI study

The amygdala is often found to be abnormally recruited in social anxiety disorder (SAD) patients. The question whether amygdala activation is primarily abnormal and affects other brain systems or whether it responds "normally" to an abnormal pattern of information conveyed by other brain structures remained unanswered. To address this question, we investigated a network of effective connectivity associated with the amygdala using Granger causality analysis on resting-state functional MRI data of 22 SAD patients and 21 healthy controls (HC). Implications of abnormal effective connectivity and clinical severity were investigated using the Liebowitz Social Anxiety Scale (LSAS). Decreased influence from inferior temporal gyrus (ITG) to amygdala was found in SAD, while bidirectional influences between amygdala and visual cortices were increased compared to HCs. Clinical relevance of decreased effective connectivity from ITG to amygdala was suggested by a negative correlation of LSAS avoidance scores and the value of Granger causality. Our study is the first to reveal a network of abnormal effective connectivity of core structures in SAD. This is in support of a disregulation in predescribed modules involved in affect control. The amygdala is placed in a central position of dysfunction characterized both by decreased regulatory influence of orbitofrontal cortex and increased crosstalk with visual cortex. The model which is proposed based on our results lends neurobiological support towards cognitive models considering disinhibition and an attentional bias towards negative stimuli as a core feature of the disorder.