The genus Eodasycladus (Lower Jurassic dasycladalean green alga) and its relationship with Palaeodasycladus

The Lower Jurassic genus Eodasycladus is discussed according to the characters of type species and compared with the other species known in the literature. The architecture of two species attributed to the genus Palaeodasycladus, P. alanensis Soka?, and P. benceki Soka?, is examined and an alternative organization of the thallus is prospected. P. alanensis is considered a valid species, but its characters require to transfer the taxon to the genus Eodasycladus. P. benceki is considered synonymous with P. alanensis.     

An electroosmotically-driven micromixer modified for high miniaturized microchannels using surface micromachining

In order to offer the ability of smaller volumes and high throughput in Lab-On-a-Chip and micro Total Analysis Systems devices, more miniaturized components are needed. Due to a low Reynolds number on the microscale, the mixing process can be particularly troublesome. This problem is compounded by the fact that more miniaturization can be challenging in a microfluidic system. In such a case, electroosmotic (EO) force is an efficient force to perturb low Reynolds number fluid. In this paper, a novel Micro-Electro-Mechanical-Systems (MEMS) based fabrication for microfluidic devices, and a more miniaturized micromixer are presented. The proposed technology process requires the covering of excited electrode patterns by a thin Silicon-Nitride (Si₃N₄) insulator layer. Fabrication parameters such as Low Pressure Chemical Vapor Deposition (LPCVD) Si₃N₄ deposition effect, and height of the Phosphor Silicate Glass (PSG) sacrificial layer were investigated for the electroosmotically-driven mixer. Particle tracing for fluid flow was illustrated, the particles were stretched and folded for a long time, which was a proof of chaotic regime. Finite Element Analysis (FEA) revealed that the mixer with covered electrodes provides the high mixing efficiency of above 90% for a 96 μm long microchannel. Using a silicon nitride insulator layer reduces high electric field gradient at sharp corners and edges of the electrodes, leading to the elimination of unwanted electrolyte effects. Thus, the excitation and geometrical parameters were optimized for the micromixer.     

The role of stallion seminal proteins in fertilisation

Seminal plasma proteins are secretory proteins originating mainly from the epididymis and the accessory sex glands. They are involved in the remodelling of the sperm surface which occurs during sperm transit through the male genital tract and continues later at ejaculation. During this process, collectively called post-testicular sperm maturation, the spermatozoa acquire the ability to fertilise an egg. Seminal plasma proteins have been shown to contribute to early and central steps of the fertilisation sequence, e.g. the establishment of the oviductal sperm reservoir, modulation of capacitation and gamete interaction. The major equine seminal plasma proteins belong to three protein classes, which contain widely occurring protein modules. Fn-2 type proteins are characterised by two or four tandemly arranged Fn-2 modules and have been implicated in the modulation of sperm capacitation. Multiple members of the cysteine-rich secretory proteins (CRISP) have been identified in the male genital tract of a number of species. CRISP proteins have been shown to be involved in various functions related to sperm-oocyte fusion, innate host defense function and ion channel blockage. Spermadhesins occur only in ungulate species. Their carbohydrate- and zona pellucida-binding properties would suggest a role of these proteins in gamete recognition. The major proteins of equine seminal plasma have been isolated and characterised regarding their expression along the male genital tract, protein structure and their functions.     

The effect of sea anemone (H. magnifica) venom on two human breast cancer lines: death by apoptosis

Venom from the sea anemone, Heteractis magnifica, has multiple biological effects including, cytotoxic, cytolytic and hemolytic activities. In this study, cytotoxicity induced by H. magnifica venom was investigated using the crystal violet assay on human breast cancer T47D and MCF7 cell lines and normal human breast 184B5 cell line. Apoptosis was also assayed via Annexin V-flourescein isothiocyanate and propidium iodide (PI) staining followed by flow cytometric analysis. Cell cycle progression and mitochondria membrane potential were studied via flow cytometry following PI and JC-1 staining respectively. H. magnifica venom induced significant reductions in viable cell numbers and increases in apoptosis in T47D and MCF7 in dose-dependent manners. A significant apoptosis-related increase in the sub G1 peak of the cell cycle in both breast cancer cell lines was also observed. Moreover, treatment by venom cleaved caspase-8, caspase-9, and activated caspase-3. Overall, H. magnifica venom was highly cytotoxic to T47D and MCF7 human breast cancer cells, and the phenomenon could be the killing phenomenon via the death receptor-mediated and the mitochondria-mediated apoptotic pathways. Consequently, H. magnifica venom has potential for the development of a breast cancer therapeutic.     

Structural and molecular characterization of equine sperm-binding fibronectin-II module proteins

Phospholipid-binding proteins in the male genital tract are characterized by differing numbers Fn-2 modules (B-domain) carrying N-terminal extensions (A-domain) of variable length. In the stallion, three different proteins were identified, SP-1, SP-2, and EQ-12. SP-1 and SP-2 of the AA'BB'- and ABB'-type, respectively, are major proteins of the seminal plasma. Here we report the cDNA sequences of SP-1, and of a new member of the SP-2 family (SPnew) and the partial characterization of their iso- and glycoforms. The phosphorylcholine (PC)-binding ability of the long Fn-2 protein, EQ-12, with four tandemly arranged Fn-2 modules was determined by PC-affinity chromatography. Expression patterns of EQ-12, and the SP-proteins were studied by means of RT-PCR, Northern blot analysis and immunological approaches indicating differential expression along the male reproductive tract. The vast majority of the short SP-1 and SP-2 proteins are produced by the ampulla whereas EQ-12 originates from the epididymis. Indirect immunofluorescence microscopy of sperm isolated from different regions of the epididymis and Western blot analysis indicate that both, the long and the short Fn-2 proteins associate to the sperm surface during post-testicular maturation. Sperm binding of Fn-2 proteins at the post-acrosome and midpiece was at first detected in the corpus epididymis. Enhanced fluorescence intensity after ejaculation point to an increased number of molecules bound to the sperm surface. The function of these proteins is discussed in regard to their structure-function relationships.     

Deciphering vascular endothelial cell growth factor/vascular permeability factor signaling to vascular permeability. Inhibition by atrial natriuretic peptide

Vascular endothelial cell growth factor (VEGF) was originally described as a potent vascular permeability factor (VPF) that importantly contributes to vascular pathobiology. The signaling pathways that underlie VEGF/VPF-induced permeability are not well defined. Furthermore, endogenous vascular peptides that regulate this important VPF function are currently unknown. We report here that VPF significantly enhances permeability in aortic endothelial cells via a linked signaling pathway, sequentially involving Src, ERK, JNK, and phosphatidylinositol 3-kinase/AKT. This leads to the serine/threonine phosphorylation and redistribution of actin and the tight junction (TJ) proteins, zona occludens-1 and occludin, and the loss of the endothelial cell barrier architecture. Atrial natriuretic peptide (ANP) inhibited VPF signaling, TJ protein phosphorylation and localization, and VPF-induced permeability. This involved both guanylate cyclase and natriuretic peptide clearance receptors. In vivo, transgenic mice that overexpress ANP showed significantly less VPF-induced kinase activation and vascular permeability compared with non-transgenic littermates. Thus, ANP acts as an anti-permeability factor by inhibiting the signaling functions of VPF that we define here and by preserving the endothelial cell TJ functional morphology.     

Purification and partial characterization of coxsackievirus B3 2A protease expressed in Escherichia coli

Reported here is the overexpression, purification and partial characterization of recombinant coxsakievirus B3 2A protease (CVB3 2A(pro)) from bacterial cells transformed with a plasmid containing the CVB3 2A(pro) cDNA sequences. The structural investigation showed that the protein contains mostly beta-strand elements and requires Zn(2+) ions as a structural component which appeared to be inhibitory if added exogenously. The purified enzyme activity was optimal at 4 degrees C and had a short half-life at physiological temperature. This feature can be the result of the presence of a high content of beta-structure and also hydrophobic residues in its structure.     

Surface plasmon resonance sensing detection of mercury and lead ions based on conducting polymer composite

A new sensing area for a sensor based on surface plasmon resonance (SPR) was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI) conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU) were obtained for PPy-CHI film due to a specific binding of chitosan with Pb(2+) and Hg(2+) ions. The Pb(2+) ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb(2+) compared to Hg(2+). The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system.