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Adipose tissue (AT) expands under obesogenic conditions. Yet, when the growth exceeds a certain limit, AT becomes dysfunctional and surplus lipids start depositing ectopically. Polymerase I and transcription release factor (PTRF) has been proposed as a mechanism leading to a dysfunctional AT by decreasing the adipogenic potential of human adipocyte precursors. However, whether or not PTRF can be secreted by the adipocytes into the bloodstream is not yet known. For this work, PTRF presence was investigated in plasma. We also produced a recombinant PTRF (rPTRF) and examined its impact on the functional interactions between the adipocyte and the hepatocyte in vitro. We demonstrated that PTRF can be found in human plasma, and is at least in part, carried by exosomes. In vitro treatment with rPTRF increased the hypertrophy and senescence of 3T3-L1 adipocytes. In turn, those rPTRF-treated adipocytes increased lipid accumulation in hepatocytes. Lastly, we found a positive correlation between circulating PTRF and the concentration of PTRF in the visceral fat depot. All these findings point toward the presence of an enlarged and dysfunctional visceral adipose tissue which secretes PTRF. This circulating PTRF behaves as an adipokine and may partially contribute to the well-known detrimental effects of visceral fat accumulation.

In the last years our society has shown a growing interest on the development of both new sources of clean energy and advanced devices able to store it. In this context supercapacitors (SCs) and hybrid systems have emerged to cover the power and energy demands. Most of these electrochemical devices use carbon materials as electrodes being the activated carbons (ACs) the most commonly ones. Nonetheless graphene (G) has emerged as a promising electrode either by itself or combined with ACs in composites. This work investigates the use of a low added value coal-derived liquid (anthracene oil, AO) for the production of pitch-like carbon precursors to synthesize suitable active electrode materials (ACs, G, AC/G) in SCs and hybrid systems. In addition to the well-known oxidative thermal polymerization of AO, a new alternative based on the use of microwave heating is presented as a promising clean route to obtain such carbon precursors resulting in energy saving, shortening time and specific nonthermal effects. The characteristics of the carbon materials obtained from both conventional/ unconventional technologies are compared mainly in terms of their specific surface area, surface chemistry and electrical conductivity which would allow the design of energy storage devices with an improved electrochemical performance.

A clear case for carbon fibre recovery and reuse exists on environmental grounds due to the high cost and energy use of virgin fibre production. On a specific energy basis, carbon fibres can be recovered at around 10% of the energy required to manufacture virgin fibres but the scale of the recovery process can make a large difference to overall cost effectiveness. This study will describe the technical and economic challenges associated with the recycling of carbon fibres, the state of the art in recycling technologies and the re-use of fibres in high performance composites.

The aim of this work was to investigate whether the nuclear matrix could provide the nucleation sites for dispersed parental nucleolar components to form post-mitotic prenucleolar bodies (PNBs). For this purpose, nuclear matrices from asynchronous populations of onion cells were fractionated, and the distribution of the insoluble components of the nucleolar processing complexes in the matrices were analysed by fibrillarin immunolabelling. The ultra-structural organization of the nuclear matrix of cells from late telophase to late G1, corresponding to the period of nucleolar reassembly and activation, was also analysed. Our results demonstrate that PNBs are structural components of the telophasic nuclear matrix and that this structure provides recruitment and assembly sites for the components of the nucleolar processing machinery, and suggests that the telophasic matrix network is involved in the early steps of post-mitotic nucleologenesis., This work was supported by the CICYT (Spain), project no. PB91-0124.

Cryopreservation of sheep embryos with ethylene glycol as a protectant appears to be more effective than glycerol, particularly at the morula stage, as has been demonstrated on the basis of in vitro and in vivo development rates after thawing. In this study we compare the ultrastructure of fresh morulae, thawed morulae, and blastocysts cryopreserved with either ethylene glycol or glycerol at the electron microscopic level, to look for cellular damage that could be responsible for proven differences in embryo survival after transfer. Embryos cryopreserved with glycerol showed unequal degrees of conservation even among blastomeres within a single embryo. In morulae, inner blastomeres were completely damaged, whereas external ones appeared to be intact. Both morulae and blastocysts cryopreserved with ethylene glycol showed a higher uniformity in blastomere conservation than embryos with glycerol. The most remarkable features in this experimental group were the presence of desmosomes following tight junctions between blastomeres and the presence of many microvilli on the outer surface of external blastomeres. These characteristics are similar in fresh embryos of the control group. Our results show that ethylene glycol protects membrane and cytoplasmic structures of embryonic cells from cryoinjury much better than glycerol. In vivo survival of embryos confirmed the ultrastructural observations. A limited permeability of glycerol would explain the observed ultrastructural differences in blastomere integrity, which depends on blastomere location and the differences between morulae and blastocysts. We conclude that the low reproductive yield after cryopreservation using glycerol can be attributed to the lack of protection of inner cells.

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8 p.-1 fig., Z-DNA forms transiently behind the active RNA polymerases, because of the mechanical torsional stress produced during transcription. In this paper, we explore the possibility that the distribution of Z-DNA stretches signals the sites related to nuclear transcription. To localize transcription, the in situ assay for active RNA polymerases, that allows the elongation of the already initiated transcripts but no initiation of new ones (runon experiments), was carried out in isolated nuclei of Allium cepa L. root meristems. Both nucleolar and non-nucleolar sites appeared labelled. Nucleoli were most active in transcription than the multiple non-nucleolar foci altogether. In situ immunodetection of Z-DNA provided images that were comparable to those obtained after the run-on assay, with one exception: while Z-DNA and transcription sites were scattered throughout the whole nucleus, Z-DNA also accumulated in the nuclear periphery, where no transcription foci were detected in the run-on assays. The peripheral Z-conformation signals might correspond to dsRNA segments present in the premRNA in the process of their export to cytoplasm. The Z-containing structures nearly disappeared when non-nucleolar RNA polymerase II-dependent transcription had been previously abolished by the adenosine analogue DRB (5,6- dichloro-1-b-D-ribofuranosylbenzimidazole). This inhibition selectively decreased the amount of all nucleoplasmic Z structures. On the other hand, the inhibition of the nucleolar RNA polymerase I by cordycepin (3’-deoxyadenosine) prevented the presence of Z-DNA in nucleoli. We propose to use the in situ immunodetection of Z-DNA as a marker of the transcription level in both nucleolus and non-peripheral nucleoplasmic regions of nuclei. Co-detection of Z-DNA and of intermediate filament (IF) proteins, the major components of the nuclear matrix, was also carried out. The IFA antibody recognises a conserved epitope essential for dimerization of the multiple IF proteins. They co-localized with most nucleolar Z-DNA, but not with the nucleoplasmic ones. In the nuclear periphery, the Zpositive signals were adjacent to the IF proteins constituting the lamina, though both signals did not often co-localize., The work has been partially supported by the Dirección General de Investigación del Ministerio de Ciencia y Tecnología of Spain (Project BMC 2001-2195). Adriana ˇCernà was supported by afellowship from the Spanish Agency of Internacional Cooperation (AECI), from the Ministerio de Asuntos Exteriores, Spain.