Students' views on the role of dreams in human life.

The present study was an attempt to investigate the subjectively perceived role of dreams. It examined the private concepts of dreams and dreaming, attitude toward dreams, and the influence of dreams on behavior, which can manifest in sharing dreams with other people, trying to interpret one's own dreams, believing they have special meaning, or behaving according to the clues given by the dream. The sample consisted of 47 participants, students ages 19-20. A structured interview, individually administered, was used. The results indicate interesting relationships between analyzed variables and gender; they also show individual differences in both common notions about dreams and the way dreams can influence other kinds of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-throughput proteomics of breast carcinoma cells: a focus on FTICR-MS

Discovery of better biomarkers for diagnosis, prognosis and therapy-response prediction is the most critical task of a scientific quest aimed at developing novel, tailormade therapies for patients with cancer. Consequently, a proteome-wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier-transform ion-cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR-MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.     

Do plants dynamically regulate nectar features through sugar sensing?

Nectar properties (volume, concentration, viscosity) change dynamically in time. As stated by Pedersen some decades ago (1958), “Nectar is not a static product remaining outside the plant once produced but is in close contact with the plant system.”¹ It is now evident that secretion may occur concomitantly with resorption and that the latter process sometimes continues after secretion has ended. The rate of the two processes may be modified dynamically by the plant in response to ecological and physiological constraints, maintaining a relatively constant nectar concentration to ensure pollinator visits (nectar homeostasis) and reallocating resources, especially during development of the ovules and pericarp after fertilization. We suspect that nectar resorption is under-estimated as a phenomenon, because it requires detailed information on the dynamics of nectar production throughout the life of the flower that is seldom available or taken into consideration. The cytological and molecular mechanisms involved in nectar resorption are almost completely unknown. Sugar sensing may have a fundamental role in nectar resorption and homeostasis. Due to direct contact with sugar solutions, nectaries may offer wide scope for insights into this phenomenon which has attracted interest as part of plant signalling systems.Key words: nectaries, nectar resorption, nectar homeostasis, nectar composition     

Aromatase expression in testes of XY, YY, and XX rainbow trout (Oncorhynchus mykiss).

The main goal of the present study was to show whether testicular cells of rainbow trout (Oncorhynchus mykiss Walbaum) either hormonally manipulated (XX males) or produced by using gamma irradiation and pressure shock (YY males, "supermales") are able to aromatize androgens into estrogens compared with the control (XY males). The expression of aromatase gene at the level of the protein and its presence in testicular tissue was investigated by means of immunohistochemistry and Western blot analysis, respectively. The positive staining for aromatase was detected in testicular cells of all trout and in efferent duct cells of XY and YY males. However, the staining intensity varied among particular trout, being strong in YY males, moderate in XY males, and weak in XX trout. It was confirmed by quantitative image analysis in which the staining intensity was expressed as relative optical density (ROD) of diaminobenzidine deposits. Significant differences were found between XY and YY trout ((**)p<0.01) and XY and XX trout ((*)p<0.05). Such differences could reflect various levels of estrogens, possibly dependent on the genetic background of the trout studied. It seems likely that differential expression of the enzyme, especially that of weak or strong intensity, causes some alterations in testicular morphology of homogametic trout. Additionally, the results indicate that an imbalance in sex hormone biosynthesis may provoke the functional alterations in testes of YY males, and, in consequence, negatively affect the fertility of "supermales".     

Rat prostate tumors express cancer procoagulant, an activator of coagulation factor X

Two common procoagulant activities associated with tumors are tissue factor and cancer procoagulant (CP), an activator of coagulation factor X. We have identified a convenient source of CP in transplanted Lobund-Wistar rat PA3 prostate tumors. CP activity was purified from 5 independent transplanted prostate tumors by column chromatography. The protein activated factor X in the absence of TF and factor VII. An antihuman CP antibody recognized rat CP in an ELISA and inactivated CP activity in a chromogenic assay. Lobund-Wistar prostate tumors may provide a convenient animal model useful in determining the role of CP in cancer development.     

Sphingosine-1-phosphate and interleukin-1 independently regulate plasminogen activator inhibitor-1 and urokinase-type plasminogen activator receptor expression in glioblastoma cells: implications for invasiveness

Glioblastoma multiforme is an invasive primary brain tumor, which evades the current standard treatments. The invasion of glioblastoma cells into healthy brain tissue partly depends on the proteolytic and nonproteolytic activities of the plasminogen activator system proteins, including the urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1), and a receptor for uPA (uPAR). Here we show that sphingosine-1-phosphate (S1P) and the inflammatory mediator interleukin-1 (IL-1) increase the mRNA and protein expression of PAI-1 and uPAR and enhance the invasion of U373 glioblastoma cells. Although IL-1 enhanced the expression of sphingosine kinase 1 (SphK1), the enzyme that produces S1P, down-regulation of SphK1 had no effect on the IL-1-induced uPAR or PAI-1 mRNA expression, suggesting that these actions of IL-1 are independent of S1P production. Indeed, the S1P-induced mRNA expression of uPAR and PAI-1 was blocked by the S1P(2) receptor antagonist JTE013 and by the down-regulation of S1P(2) using siRNA. Accordingly, the inhibition of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1/2 and Rho-kinase, two downstream signaling cascades activated by S1P(2), blocked the activation of PAI-1 and uPAR mRNA expression by S1P. More importantly, the attachment of glioblastoma cells was inhibited by the addition of exogenous PAI-1 or siRNA to uPAR, whereas the invasion of glioblastoma cells induced by S1P or IL-1 correlated with their ability to enhance the expression of PAI-1 and uPAR. Collectively, these results indicate that S1P and IL-1 activate distinct pathways leading to the mRNA and protein expression of PAI-1 and uPAR, which are important for glioblastoma invasiveness.     

Marked differences in differentiation propensity among human embryonic stem cell lines

The differentiation potential of 17 human embryonic stem (hES) cell lines was compared. Some lines exhibit a marked propensity to differentiate into specific lineages, often with >100-fold differences in lineage-specific gene expression. For example, HUES 8 is best for pancreatic differentiation and HUES 3 for cardiomyocyte generation. These non-trivial differences in developmental potential among hES cell lines point to the importance of screening and deriving lines for lineage-specific differentiation.     

Monomethylarsonate (MMAv) exerts stronger effects than arsenate on the structure and thermotropic properties of phospholipids bilayers

Methylation of inorganic arsenic has been regarded as a detoxification mechanism because its metabolites monomethylarsonic acid (MMA(v)) and dimethylarsinic acid (DMA(v)) are supposed to be less toxic than inorganic arsenite and arsenate. In recent years, however, this interpretation has been questioned. Additionally, there are insufficient reports concerning the effects of arsenic compounds on cell membrane structure and functions. With the aim to better understand the molecular mechanisms of the interaction of MMA(v) and arsenate with cell membranes, we have utilized molecular models consisting in bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of many cell membranes including that of the human erythrocyte. The capacity of MMA(v) and arsenate to perturb the bilayer structures of DMPC and DMPE was evaluated by X-ray diffraction; the modifications of their thermotropic behavior were followed by differential scanning calorimetry (DSC), while DMPC large unilamellar vesicles (LUV) were studied by fluorescence spectroscopy. It was found that MMA(v) and arsenate did not structurally perturb DMPC bilayers; however, DMPE bilayers did suffer structural perturbations by MMA(v). DSC measurements also revealed that DMPE's thermotropic properties were significantly affected by arsenicals, where MMA(v) was more effective than arsenate, whilst only slight modifications were observed in the case of DMPC-MMA(v) system.     

Variability in the sculpture of the shell aperture of Ruthenica filograna (Rossmassler, 1836) (Gastropoda: Clausiliidae) in specimens from natural populations and from laboratory breeding

An analysis of variability in the sculpture of shell apertureswas carried out for 1,087 specimens of Ruthenica filograna from33 localities and for 20 laboratory-bred individuals rearedfrom parents from a single locality. Nine patterns of aperturesculpture were distinguished. There are usually two kinds ofsculpture: with one plica in the aperture being an extensionof the inferior lamella, and without plicae in the aperture.Sporadically, the subcolumellar lamella may be connected withthe lip of the aperture by a plica. Additional plicae occurin the aperture only rarely. All populations examined showedvariations in the number and arrangement of plicae. The coefficientof variation in the number of plicae in the shell aperture rangedfrom 32.6% to 121.8% within localities. No consistent relationshipwas found between the geographical location and the shell sculpturepattern. Specimens bred in the laboratory developed shell apertureswith a variety of sculptural patterns, including one presentneither in the parents, nor in the population from which itcame. This characteristic is probably phenotypically plastic.It cannot be used for taxonomic purposes, and it is suggestedthat great caution is needed before using similar charactersin other species. (Received 27 March 2007; accepted 4 February 2008)