Rheological investigation on dynamic and structure of separated phases in polymer mixture–ionic surfactant ternary system

Ternary systems composed of 0.30% sodium carboxymethyl cellulose (NaCMC), 0.70% hydroxypropylmethyl cellulose (HPMC), and sodium dodecylsulfate (SDS) of various concentrations (0.00–2.00%), were investigated by oscillatory and flow shear rheometry. The investigation on binary mixtures of HPMC/SDS (0.7% HPMC, 0.00–2.00% SDS) and HPMC/NaCMC (1.00% polymer mixtures with HPMC/NaCMC mass ratio ranging from 1/0 to 0/1) was also carried out. In the examined systems, various interactions between HPMC–NaCMC, HPMC–SDS and NaCMC–(HPMC–SDS) take place. The interactions may bring about phase separation in the ternary system into HPMC–SDS complex rich phase (coacervate), and NaCMC rich phase (supernatant). The possibility of employing the interactions in the ternary system to vary structural properties of the coacervate, in terms of viscoelasticity and shear rate influence, was investigated. Rheological properties of the ternary system, as well as of the separated coacervate and the supernatant were tested. Influence of shear rate on the interactions taking place in both the binary and the ternary mixtures was examined. It was found that the applied shear rate can influence the interactions. Molecular mechanisms determining the rheological properties of the coacervate were suggested. It was found that complex intermolecular interactions in the ternary system can be employed to attain control over the structural properties of the coacervate phase.     

Platelet-Rich Plasma,Especially When Combined with a TGF-β Inhibitor Promotes Proliferation,Viability and Myogenic Differentiation of Myoblasts In Vitro

Regeneration of skeletal muscle after injury is limited by scar formation, slow healing time and a high recurrence rate. A therapy based on platelet-rich plasma (PRP) has become a promising lead for tendon and ligament injuries in recent years, however concerns have been raised that PRP-derived TGF-β could contribute to fibrotic remodelling in skeletal muscle after injury. Due to the lack of scientific grounds for a PRP -based muscle regeneration therapy, we have designed a study using human myogenic progenitors and evaluated the potential of PRP alone and in combination with decorin (a TGF-β inhibitor), to alter myoblast proliferation, metabolic activity, cytokine profile and expression of myogenic regulatory factors (MRFs). Advanced imaging multicolor single-cell analysis enabled us to create a valuable picture on the ratio of quiescent, activated and terminally committed myoblasts in treated versus control cell populations. Finally high-resolution confocal microscopy validated the potential of PRP and decorin to stimulate the formation of polynucleated myotubules. PRP was shown to down-regulate fibrotic cytokines, increase cell viability and proliferation, enhance the expression of MRFs, and contribute to a significant myogenic shift during differentiation. When combined with decorin further synergistc effects were identified. These results suggest that PRP could not only prevent fibrosis but could also stimulate muscle commitment, especially when combined with a TGF-β inhibitor.     

The Cerebro-oculo-facio-skeletal Syndrome Point Mutation F231L in the ERCC1 DNA Repair Protein Causes Dissociation of the ERCC1-XPF Complex

The ERCC1-XPF heterodimer, a structure-specific DNA endonuclease, is best known for its function in the nucleotide excision repair (NER) pathway. The ERCC1 point mutation F231L, located at the hydrophobic interaction interface of ERCC1 (excision repair cross-complementation group 1) and XPF (xeroderma pigmentosum complementation group F), leads to severe NER pathway deficiencies. Here, we analyze biophysical properties and report the NMR structure of the complex of the C-terminal tandem helix-hairpin-helix domains of ERCC1-XPF that contains this mutation. The structures of wild type and the F231L mutant are very similar. The F231L mutation results in only a small disturbance of the ERCC1-XPF interface, where, in contrast to Phe²³¹, Leu²³¹ lacks interactions stabilizing the ERCC1-XPF complex. One of the two anchor points is severely distorted, and this results in a more dynamic complex, causing reduced stability and an increased dissociation rate of the mutant complex as compared with wild type. These data provide a biophysical explanation for the severe NER deficiencies caused by this mutation.     

Atmospheric conditions during high ragweed pollen concentrations in Zagreb,Croatia

We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002–2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m³) for our analysis: period A (3–4 September 2002) and period B (6–7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002–2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m³. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.     

Matrix metalloprotease-1a promotes tumorigenesis and metastasis

Matrix metalloprotease-1 (MMP1), a collagenase and activator of the G protein-coupled protease activated receptor-1 (PAR1), is an emerging new target implicated in oncogenesis and metastasis in diverse cancers. However, the functional mouse homologue of MMP1 in cancer models has not yet been clearly defined. We report here that Mmp1a is a functional MMP1 homologue that promotes invasion and metastatic progression of mouse lung cancer and melanoma. LLC1 (Lewis lung carcinoma) and primary mouse melanoma cells harboring active BRAF express high levels of endogenous Mmp1a, which is required for invasion through collagen. Silencing of either Mmp1a or PAR1 suppressed invasive stellate growth of lung cancer cells in three-dimensional matrices. Conversely, ectopic expression of Mmp1a conferred an invasive phenotype in epithelial cells that do not express endogenous Mmp1a. Consistent with Mmp1a acting as a PAR1 agonist in an autocrine loop, inhibition or silencing of PAR1 resulted in a loss of the Mmp1a-driven invasive phenotype. Knockdown of Mmp1a on tumor cells resulted in significantly decreased tumorigenesis, invasion, and metastasis in xenograft models. Together, these data demonstrate that cancer cell-derived Mmp1a acts as a robust functional homologue of MMP1 by conferring protumorigenic and metastatic behavior to cells.     

Zwitterionic biphenyl quinone methides in photodehydration reactions of 3-hydroxybiphenyl derivatives: laser flash photolysis and antiproliferation study

In aqueous media, photochemical excitation to S(1) of 3-phenylphenols 4-8 leads to deprotonation of the phenol OH, coupled with protonation of the benzyl alcohol and overall dehydration that delivers zwitterions 17-21. The zwitterions react with nucleophiles (CH(3)OH, CF(3)CH(2)OH and ethanolamine) converting them in high quantum yields to the corresponding adducts and photosolvolysis products (for photomethanolysis Φ~0.1-0.5). Zwitterions 20 and 21 were characterized by laser flash photolysis in CH(3)CN-H(2)O (τ~7.5 and 25 μs, respectively) and the associated quenching rate constants with nucleophiles azide and ethanolamine determined. In vitro studies of antiproliferative activity of the photochemicaly generated QMs and zwitterions formed from 2-, 3- and 4-phenylphenols were carried out on three human cancer cell lines HCT 116 (colon), MCF-7 (breast), and H 460 (lung). Irradiation of cells incubated with 3, 6, and 26 showed enhanced antiproliferative activity compared to the cells that were not irradiated.     

Synthesis and immunostimulating properties of novel adamant-1-yl tripeptides

The aim of this work was to prepare L- and D-(adamant-1-yl)-Gly-L-Ala-D-isoGln peptides in order to study their adjuvant (immunostimulating) activities. Adjuvant activity of adamant-1-yl tripeptides was tested in the mouse model using ovalbumin as an antigen and in comparison to the peptidoglycan monomer (PGM; β-D-GlcNAc-(1→4)-D-MurNAc-L-Ala-D-isoGln-mesoDAP(εNH(2) )-D-Ala-D-Ala) and structurally related adamant-2-yl tripeptides.     

The Differences in the Cellular and Plasma Antioxidative Capacity Between Transient and Defined Focal Brain Ischemia: Does it Suggest Supporting Time-Dependent Neuroprotection Therapy?

There are many opened questions about the precocious role of oxidative stress in the physiopathology of the early stage of transitory ischemic attack (TIA) and defined focal brain ischemia, as well as about its correlation with clinical severity, short-lasting and clinical outcome prediction in these conditions. The study evaluates the values of glutathione (GSH), glutathione peroxidase, and superoxide dismutase (SOD) in hemolysates and total thiol content (–SH), advanced oxidation protein products (AOPP), SOD, and malondialdehyde (MDA) in plasma, in TIA and stroke patients in the early stage of their neurological onset. The results are interpreted in view of the potential relationship between tested parameters and clinical severity and clinical outcome prediction. Better hemolysates’ and total antioxidant profile with higher values of AOPP were observed in TIA compared to stroke patients (p < 0.05). The stroke patients with initially better clinical presentation showed better antioxidant profile with lower values of AOPP (p < 0.05). In TIA patients, this was observed for GSH, –SH content, and AOPP (p < 0.05), which correlated with a short risk for stroke occurrence in this group (p < 0.01). Beyond MDA values, all tested parameters showed correlation with clinical outcome in stroke patients (p < 0.05). The measurement of oxidative stress in TIA and stroke patients would be important for identifying patients’ subgroups which might receive supporting therapy providing better neurological recovery and clinical outcome. That approach might give us an additional view of a short-lasting risk of stroke occurrence after TIA, and its clinical outcome and prognosis.     

Modulation of urokinase plasminogen activator system by poly(ADP-ribose)polymerase-1 inhibition

The urokinase plasminogen activator (uPA) system is a complex regulator of extracellular proteolysis which is involved in various physiological and pathological processes. The major components of this system are the serine protease uPA, two inhibitors PAI-1 and PAI-2, and the receptor uPAR. It has been previously shown by several groups that the uPA system has an important role in cancer progression and therefore its possible prognostic and therapeutic value has been evaluated. The aim of this study is to tackle the role of poly(ADP-ribosyl)ation in the induction of uPA activity in a glioblastoma cell line, A1235. This cell line is sensitive to alkylation damage and is a model for drug treatment. The components of the uPA system and the level of DNA damage were analyzed after alkylation agent treatment in combination with poly(ADP-ribose)polymerase-1 (PARP-1) inhibition. Here we show that the increase in uPA activity results from the net balance change between uPA and its inhibitor at mRNA level. Further, PARP-1 inhibition exerts its influence on uPA activity through DNA damage increase. Involvement of several signaling pathways, as well as cell specific regulation influencing the uPA system are discussed.