Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration

Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here “Antennal Dorsal Organs.” Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla‐like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla‐like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed. J. Morphol. 277:128–137, 2016. © 2015 Wiley Periodicals, Inc.     

A simple and rapid method for the purification of the mitochondrial porin from mammalian tissues

A new, simple and rapid procedure for the purification of high amounts of mitochondrial porins from different tissues of mammalia is described. The method consists in a single step hydroxyapatite / celite chromatography of Triton X-100 solubilized mitochondrial membranes. For optimal purification several factors are critical such as the absence of salts, a low protein / detergent ratio and an exact hydroxyapatite / celite ratio of 2:1.     

Application of X-ray microanalysis to cell suspensions of oil palm (Elaeis guineensis Jacq.)

X-ray microanalysis has been used to determine the elemental composition of oil-palm (Elaeis guineesis) cell suspensions without the use of cryoprotectants. Results based on individual cells were gathered over a typical growth cycle of 14 d. During the log phase (5–7 d) there is an increase in the number of cells containing high concentrations of both K (400 mmol kg^-1 dry weight) and P (400 mmol kg^-1 dry weight). Morphologically these cells had thin cell walls and were frequently joined to other cells (two to five cells per clump).     

Tissue and subcellular immunolocalisation of enzymes of lignin synthesis in differentiating and wounded hypocotyl tissue of French bean (Phaseolus vulgaris L.)

Antisera raised againstl-phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), and a cationic cell-wall peroxidase, which had all been purified from suspension-cultured cells of French bean, have been used to carry out immunogold localisations in the growing plant. Immunoglobulin-G fractions were prepared from each antiserum and used to study the distribution of the enzymes in differentiating and wounded hypocotyls by immunogold techniques and visualisation by both light and electron microscopy. Following silver enhancement to amplify the signal, proteins were detected by confocal microscopy in both developing (pre-xylem/ phloem) and later metaxylem stelar tissue.l-Phenylalanine ammonia-lyase and C4H also accumulated in cells adjacent to metaxylem, presumably involved in maintaining a supply of phenylpropanoid precursors to the enucleated xylem for further lignin synthesis. In these cells, PAL subunits were cytosolic although some were associated with endomembrane. Cinnamate-4-hydroxylase was wholly associated with membrane and particularly high concentrations were found in the Golgi bodies. The cationic peroxidase accumulated in xylem at sites of secondary thickening and in the middle lamella. The three proteins are also involved in defensive lignification. Thus when visualised by light microscopy, PAL and C4H were seen to accumulate to high levels throughout the cell types in wound sites and especially in the epidermal cells. An even more intense general distribution was found upon hyperinduction of wounded cells with-aminooxy--phenylpropionic acid. At the subcellular level, PAL was found to be localised in the cytosol in the wounded cells; however, because of the loss of membrane through mechanical damage, association with membrane structures, particularly endoplasmic reticulum, in unwounded cells is not entirely ruled out. Cinnamate-4-hydroxylase was associated with membranes when these were preserved. In wounded tissue, the peroxidase was found at the growing edges of tylose-like structures in the vascular xylem.Abbreviations AOPP -aminooxy--phenylpropionic acid - C4H cinnamic acid-4-hydroxylase - CHS chalcone synthase - GRP glycine-rich glycoprotein - HRGP hydroxyproline-rich glycoprotein - Ig immunoglobulin - PAL phenylalanine ammonia-lyase G.P.B. thanks the Agicultural and Food Research Council for support.     

A distinct basic fibroblast growth factor (FGF-2)/FGF receptor interaction distinguishes urokinase-type plasminogen activator induction from mitogenicity in endothelial cells.

Basic fibroblast growth factor (FGF-2) induces cell proliferation and urokinase-type plasminogen activator (uPA) production in fetal bovine aortic endothelial GM 7373 cells. In the present paper we investigated the role of the interaction of FGF-2 with tyrosine-kinase (TK) FGF receptors (FGFRs) in mediating uPA up-regulation in these cells. The results show that FGF-2 antagonists suramin, protamine, heparin, the synthetic peptide FGF-2(112-155), and a soluble form of FGFR-1 do not inhibit FGF-2-mediated uPA up-regulation at concentrations that affect growth factor binding to cell surface receptors and mitogenic activity. In contrast, tyrosine phosphorylation inhibitors and overexpression of a dominant negative TK- mutant of FGFR-1 abolish the uPA-inducing activity of FGF-2, indicating that FGFR and its TK activity are essential in mediating uPA induction. Accordingly, FGF-2 induces uPA up-regulation in Chinese hamster ovary cells transfected with wild-type FGFR-1, -2, -3, or -4 but not with TK- FGFR-1 mutant. Small unilamellar phosphatidyl choline:cholesterol vesicles loaded with FGF-2 increased uPA production in GM 7373 cells in the absence of a mitogenic response. Liposome-encapsulated FGF-2 showed a limited but significant capacity, relative to free FGF-2, to interact with FGFR both at 4 degrees C and 37 degrees C and to be internalized within the cell. uPA up-regulation by liposome-encapsulated FGF-2 was quenched by neutralizing anti-FGF-2 antibodies, indicating that the activity of liposome-delivered FGF-2 is mediated by an extracellular action of the growth factor. Taken together, the data indicate that a distinct interaction of FGF-2 with FGFR, quantitatively and/or qualitatively different from the one that leads to mitogenicity, is responsible for the uPA-inducing activity of the growth factor.     

Detailed finite element modelling of deep needle insertions into a soft tissue phantom using a cohesive approach

Detailed finite element modelling of needle insertions into soft tissue phantoms encounters difficulties of large deformations, high friction, contact loading and material failure. This paper demonstrates the use of cohesive elements in high-resolution finite element models to overcome some of the issues associated with these factors. Experiments are presented enabling extraction of the strain energy release rate during crack formation. Using data from these experiments, cohesive elements are calibrated and then implemented in models for validation of the needle insertion process. Successful modelling enables direct comparison of finite element and experimental force–displacement plots and energy distributions. Regions of crack creation, relaxation, cutting and full penetration are identified. By closing the loop between experiments and detailed finite element modelling, a methodology is established which will enable design modifications of a soft tissue probe that steers through complex mechanical interactions with the surrounding material.     

How Skill Expertise Shapes the Brain Functional Architecture: An fMRI Study of Visuo-Spatial and Motor Processing in Professional Racing-Car and Na?ve Drivers

The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI), we measured brain activity while eleven Formula racing-car drivers and eleven ‘naïve’ volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD) signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both ‘quantitative’ and ‘qualitative’ modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased ‘neural efficiency’ in the brain of highly skilled individuals.     

Genetic and molecular characterization of the human Osteosarcoma 3AB‐OS cancer stem cell line: A possible model for studying osteosarcoma origin and stemness

Finding new treatments targeting cancer stem cells (CSCs) within a tumor seems to be critical to halt cancer and improve patient survival. Osteosarcoma is an aggressive tumor affecting adolescents, for which there is no second‐line chemotherapy. Uncovering new molecular mechanisms underlying the development of osteosarcoma and origin of CSCs is crucial to identify new possible therapeutic strategies. Here, we aimed to characterize genetically and molecularly the human osteosarcoma 3AB‐OS CSC line, previously selected from MG63 cells and which proved to have both in vitro and in vivo features of CSCs. Classic cytogenetic studies demonstrated that 3AB‐OS cells have hypertriploid karyotype with 71–82 chromosomes. By comparing 3AB‐OS CSCs to the parental cells, array CGH, Affymetrix microarray, and TaqMan® Human MicroRNA array analyses identified 49 copy number variations (CNV), 3,512 dysregulated genes and 189 differentially expressed miRNAs. Some of the chromosomal abnormalities and mRNA/miRNA expression profiles appeared to be congruent with those reported in human osteosarcomas. Bioinformatic analyses selected 196 genes and 46 anticorrelated miRNAs involved in carcinogenesis and stemness. For the first time, a predictive network is also described for two miRNA family (let‐7/98 and miR‐29a,b,c) and their anticorrelated mRNAs (MSTN, CCND2, Lin28B, MEST, HMGA2, and GHR), which may represent new biomarkers for osteosarcoma and may pave the way for the identification of new potential therapeutic targets. J. Cell. Physiol. 228: 1189–1201, 2013. © 2012 Wiley Periodicals, Inc.     

Computational, spectroscopic, and resonant mirror biosensor analysis of the interaction of adrenodoxin with native and tryptophan-modified NADPH-adrenodoxin reductase

In steroid hydroxylation system in adrenal cortex mitochondria, NADPH-adrenodoxin reductase (AR) and adrenodoxin (Adx) form a short electron-transport chain that transfers electrons from NADPH to cytochromes P-450 through FAD in AR and [2Fe-2S] cluster in Adx. The formation of [AR/Adx] complex is essential for the electron transfer mechanism in which previous studies suggested that AR tryptophan (Trp) residue(s) might be implicated. In this study, we modified AR Trps by N-bromosuccinimide (NBS) and studied AR binding to Adx by a resonant mirror biosensor. Chemical modification of tryptophans caused inhibition of electron transport. The modified protein (AR*) retained the native secondary structure but showed a lower affinity towards Adx with respect to AR. Activity measurements and fluorescence data indicated that one Trp residue of AR may be involved in the electron transferring activity of the protein. Computational analysis of AR and [AR/Adx] complex structures suggested that Trp193 and Trp420 are the residues with the highest probability to undergo NBS-modification. In particular, the modification of Trp420 hampers the correct reorientation of AR* molecule necessary to form the native [AR/Adx] complex that is catalytically essential for electron transfer from FAD in AR to [2Fe-2S] cluster in Adx. The data support an incorrect assembly of [AR*/Adx] complex as the cause of electron transport inhibition.