An isolate of Rhizopus nigricans capable of tolerating and removing pentachlorophenol

Rhizopus nigricans, isolated from an industrial effluent (paper mill), was resistant to pentachlorophenol (PCP) in Petri dishes and in submerged cultures (100 and 25 mg l^–1 respectively). It was shown that this strain of R. nigricans can remove PCP in submerged culture. When 12.5 mg of PCPl^–1 were added at 48 h, this compound had been completely removed by 144h. Results indicated that the fungus did not produce extracellular lignin peroxidase (LiP) and laccase, but extracellular phenoloxidase production was observed. The synthesis of the latter enzyme was stimulated by the presence of PCP and/or tyrosine. These results indicate that this fungus, and probably other filamentous fungi, have an interesting potential to be used in processes for chlorophenol biodegradation.     

Cyclosporin-A Inhibits Constitutive Nitric Oxide Synthase Activity and Neuronal and Endothelial Nitric Oxide Synthase Expressions after Spinal Cord Injury in Rats

Nitric oxide (NO) plays a role in the pathophysiology of spinal cord injury (SCI). NO is produced by three types of nitric oxide synthase (NOS) enzymes: The constitutive Ca²⁺/calmodulin-dependent neuronal NOS (nNOS) and endothelial NOS (eNOS) isoforms, and the inducible calcium-independent isoform (iNOS). During the early stages of SCI, nNOS and eNOS produce significant amounts of NO, therefore, the regulation of their activity and expression may participate in the damage after SCI. In the present study, we used Cyclosporin-A (CsA) to further substantiate the role of Ca-dependent NOS in neural responses associated to SCI. Female Wistar rats were subjected to SCI by contusion, and killed 4 h after lesion. Results showed an increase in the activity of constitutive NOS (cNOS) after lesion, inhibited by CsA (2.5 mg/kg i.p.). Western blot assays showed an increased expression of both nNOS and eNOS after trauma, also antagonized by CsA administration.     

The Fatty Acid Profile Analysis of Cyperus laxus Used for Phytoremediation of Soils from Aged Oil Spill-Impacted Sites Revealed That This Is a C18:3 Plant Species

The effect of recalcitrant hydrocarbons on the fatty acid profile from leaf, basal corm, and roots of Cyperus laxus plants cultivated in greenhouse phytoremediation systems of soils from aged oil spill-impacted sites containing from 16 to 340 g/Kg total hydrocarbons (THC) was assessed to investigate if this is a C18:3 species and if the hydrocarbon removal during the phytoremediation process has a relationship with the fatty acid profile of this plant. The fatty acid profile was specific to each vegetative organ and was strongly affected by the hydrocarbons level in the impacted sites. Leaf extracts of plants from uncontaminated soil produced palmitic acid (C16), octadecanoic acid (C18:0), unsaturated oleic acids (C18:1-C18:3), and unsaturated eichosanoic (C20:2-C20:3) acids with a noticeable absence of the unsaturated hexadecatrienoic acid (C16:3); this finding demonstrates, for the first time, that C. laxus is a C18:3 plant. In plants from the phytoremediation systems, the total fatty acid contents in the leaf and the corm were negatively affected by the hydrocarbons presence; however, the effect was positive in root. Interestingly, under contaminated conditions, unusual fatty acids such as odd numbered carbons (C15, C17, C21, and C23) and uncommon unsaturated chains (C20:3n6 and C20:4) were produced together with a remarkable quantity of C22:2 and C24:0 chains in the corm and the leaf. These results demonstrate that weathered hydrocarbons may drastically affect the lipidic composition of C. laxus at the fatty acid level, suggesting that this species adjusts the cover lipid composition in its vegetative organs, mainly in roots, in response to the weathered hydrocarbon presence and uptake during the phytoremediation process.     

Locally Confined Clonal Complexes of Mycobacterium ulcerans in Two Buruli Ulcer Endemic Regions of Cameroon

Background Mycobacterium ulcerans is the causative agent of the necrotizing skin disease Buruli ulcer (BU), which has been reported from over 30 countries worldwide. The majority of notified patients come from West African countries, such as Côte d’Ivoire, Ghana, Benin and Cameroon. All clinical isolates of M. ulcerans from these countries are closely related and their genomes differ only in a limited number of single nucleotide polymorphisms (SNPs).ConclusionsOur comparative genomic analysis revealed that M. ulcerans clones diversify locally by the accumulation of SNPs. Case isolates coming from more recently emerging BU endemic areas, such as the Mapé river basin, may be less diverse than populations from longer standing disease foci, such as the Nyong river basin. Exchange of strains between distinct endemic areas seems to be rare and local clonal complexes can be easily distinguished by whole genome sequencing.     

Functional K(v)10.1 channels localize to the inner nuclear membrane

Ectopically expressed human K(V)10.1 channels are relevant players in tumor biology. However, their function as ion channels at the plasma membrane does not totally explain their crucial role in tumors. Both in native and heterologous systems, it has been observed that a majority of K(V)10.1 channels remain at intracellular locations. In this study we investigated the localization and possible roles of perinuclear K(V)10.1. We show that K(V)10.1 is expressed at the inner nuclear membrane in both human and rat models; it co-purifies with established inner nuclear membrane markers, shows resistance to detergent extraction and restricted mobility, all of them typical features of proteins at the inner nuclear membrane. K(V)10.1 channels at the inner nuclear membrane are not all transported directly from the ER but rather have been exposed to the extracellular milieu. Patch clamp experiments on nuclei devoid of external nuclear membrane reveal the existence of channel activity compatible with K(V)10.1. We hypothesize that K(V)10.1 channels at the nuclear envelope might participate in the homeostasis of nuclear K(+), or indirectly interact with heterochromatin, both factors known to affect gene expression.     

C-kit mutations and PKC crosstalks: PKC translocates to nucleous only in cells HMC⁵⁶⁰,⁸¹⁶

The human mast cell lines HMC‐1⁵⁶⁰ and HMC‐1^560,816 were used to study histamine release, Ca²⁺ signaling and protein kinase C (PKC) localization and expression, with phorbol 12‐myristate 13‐acetate (PMA). Both sublines carry activating mutations in the proto‐oncogene of c‐kit that cause autophosphorylation and permanent c‐kit tyrosine kinase activation. Both have the Gly‐560 → Val mutation but only the second carries the Asp‐816 → Val mutation. In this study, it was observed that the stimulation of PKC has different effects in HMC‐1⁵⁶⁰ and HMC‐1^560,816 and this would be related to the difference in activating mutations in both mast cell lines. PKC activation increases ionomycin‐induced histamine release in HMC‐1⁵⁶⁰. This article demonstrates an opposite histamine response in HMC‐1^560,816 cells, even though classical PKCs are the family of isozymes responsible for this effect in both cellular lines. Furthermore, it can be observed that upon cell stimulation with PMA, primarily cytosolic PKC translocates to the nucleous in HMC‐1^560,816 cells, but not in HMC‐1⁵⁶⁰ cell line. J. Cell. Biochem. 112: 2637–2651, 2011. © 2011 Wiley‐Liss, Inc.     

The current and potential role of urban metabolism studies to analyze the role of food in urban sustainability

Food supply chains are essential for urban sustainability. To reflect on the state of knowledge on urban food flows in urban metabolism research, and the actual and potential role of urban metabolism studies to tackle food sustainability in cities, we systematically review scientific research on food from an urban metabolism perspective and apply statistical and thematic analyses. The analysis of 89 studies provides insights as to the relation between food supply and (environmental and social dimensions of) urban sustainability. First, food is an important contributor to urban environmental impacts, if a consumption-based approach is adopted. Secondly, the social impacts of urban food supply remain scarcely studied in urban metabolism research, but emerging results on public health, malnutrition, and food waste appear promising. In parallel, we find that the findings of the studies fail to engage with debates present in the broader literature, such as that of food justice. Our analysis shows that most studies focus on large cities in high-income, data-rich countries. This limits our understanding of global urban food supply. Existing studies use innovative mixed-methods to produce robust accounts of urban food flows in data-scarce contexts; expanding these accounts is necessary to get a better understanding of how urban food supply and its diverse impacts in terms of environmental and social sustainability may vary across cities, a necessary step for the urban metabolism literature to contribute to current debates around food sustainability and justice.     

Differential Expression of Cytochrome P450 Enzymes in Normal and Tumor Tissues from Childhood Rhabdomyosarcoma

Intratumoral expression of genes encoding Cytochrome P450 enzymes (CYP) might play a critical role not only in cancer development but also in the metabolism of anticancer drugs. The purpose of this study was to compare the mRNA expression patterns of seven representative CYPs in paired tumor and normal tissue of child patients with rabdomyosarcoma (RMS). Using real time quantitative RT-PCR, the gene expression pattern of CYP1A1, CYP1A2, CYP1B1, CYP2E1, CYP2W1, CYP3A4, and CYP3A5 were analyzed in tumor and adjacent non-tumor tissues from 13 child RMS patients. Protein concentration of CYPs was determined using Western blot. The expression levels were tested for correlation with the clinical and pathological data of the patients. Our data showed that the expression levels of CYP1A1 and CYP1A2 were negligible. Elevated expression of CYP1B1 mRNA and protein was detected in most RMS tumors and adjacent normal tissues. Most cancerous samples exhibit higher levels of both CYP3A4 and CYP3A5 compared with normal tissue samples. Expression of CYP2E1 mRNA was found to be significantly higher in tumor tissue, however no relation was found with protein levels. CYP2W1 mRNA and/or protein are mainly expressed in tumors. In conclusion, we defined the CYP gene expression profile in tumor and paired normal tissue of child patients with RMS. The overexpression of CYP2W1, CYP3A4 and CYP3A5 in tumor tissues suggests that they may be involved in RMS chemoresistance; furthermore, they may be exploited for the localized activation of anticancer prodrugs.