Quantitative methods for scoring cell migration and invasion in filter-based assays

The ability of cells to traverse pores in a biocompatible filter provides means for examining cell chemoattraction. Filter-based assays also permit rapid, quantitative assessment of the in vitro migratory and invasive potential of tumor cells. Scoring migration has relied on visual counting of stained cells which appear on the underside of the filter and determining a true percentage score involves arduous counting of cells on both filter surfaces. Visual counting of random fields may be unreliable, and counting all fields is laborious. In the present study we developed and compared two alternative methods for scoring cell numbers in filter-based assays, a colorimetric assay of toluidine blue binding, and a radioassay of cells prelabeled with [3H]thymidine. Each method was evaluated for sensitivity, variability, ease of use and efficiency, and suitability for use in assays of cell migration and invasion. The radiolabeling method proved to be sensitive and reliable and was the most efficient technique. Although less sensitive and specific, the colorimetric dye method offered a rapid and reliable, nonradioactive alternative with the distinct advantage of preserving intact cultures for follow-up visual assessments. We conclude that colorimetric and radiolabel scoring of filter-based assays are reliable and efficient semiautomated methods which provide means to obtain more complete assessments of cell migration and invasion.     

Medium and substitution pattern effects on the action of hydroxyflavones as photoprotectors against singlet molecular oxygen-mediated photooxidation of fats

The ability of mono-, di-, tri-and tetra-hydroxyflavones (7-and 3-hy-droxyflavones, 7, 8-dihydroxyflavone, baicalein and fisetin) to act as photoprotectors against singlet molecular oxygen [O²(Δ_g)]-initiated photooxidation of fats has been established by a kinetic study. The overall quenching rate constants for a series of five hydroxyflavones perfectly parallel their respective behaviour as inhibitors of the sensitized photooxidation of linoleic acid. The best antioxidative effect was exerted by 7-hydroxyflavone which does not chemically react with O²(¹Δ_g). Nevertheless for the remaining flavonoids of the series, the physical deactivation of O²(¹Δ_g) largely prevails over the chemical process. As for the cases of phenols and related hydroxy-aromatic derivatives, the ionization of the -OH group in the flavones, dramatically accelerates the rate of photooxidation. Under these conditions, the 7-hydroxyflavone also reacts effectively with O²(¹Δ_g). Given that flavonoids are natural oil components, this medium effect should be taken into account during the oil-refining process, in order to avoid the flavonoid photodestruction.     

Molecular dynamics simulations of polyphosphazenes: poly[bis(chloro)phosphazene][NPCl2] n

Suitable parameter sets for the CHARMm force field were derived for the structural units in polychlorophosphazene [P=N, P N, P Cl] using the Dinur Hagler energy second derivative procedure based on quantum mechanical SCI calculations using the 6–31G^* basis set. To validate the reliability of the parameter set, structural results obtained with CHARMm for the adopted model compounds (OP₂NCl₅ and OP₃N₂Cl₅) were compared with those derived fromab initio quantum mechanics using the 6–31G^* basis set. Application of molecular dynamics (MD) simulations in combinatioin with the available X-ray diffraction data provided structural and conformational information on the polymer. The calculation made using the periodic boundary conditions (PBC) agree well with the polychlorophosphazene ordered in a monoclinic unit cell (a=5.98,b=12.99,c=4.92 A; β=111.7). This model was stabilized mainly by the image atoms contribution to the electrostatic energy term and had aquasi-planar conformation of the backbone chain (glide symmetry). The MD calculations also provided evidence that the difference between single and double PN bonds is less marked than that measured experimentally. This result is, however, in agreement with more recent and accurate X-ray studies on poly(methylphosphazene). Validation of the polymer model provided a complete picture, otherwise experimentally inaccessible, of the internal fluctuations of the polymeric chains.     

Bulk modification of styrene–butadiene–styrene triblock copolymer with maleic anhydride

The bulk modification of SBS rubber with maleic anhydride in a mixing chamber of a Haake rheomixer was studied. The effect of temperature, maleic anhydride, and benzoyl peroxide concentrations on the grafting efficiency was evaluated. High grafting efficiency was achieved when the ratio of peroxide and maleic anhydride concentration was high. On the other hand, on this condition high insoluble fraction was generated. The addition of a diamine, 4,4′‐diaminediphenylmethane to the reaction mixture minimizes the amount of insoluble polymer. However, the grafted MAH content also decreases. The graft copolymer was characterized by infrared spectroscopy and the grafting extension was determined by titration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2953–2960, 2002; DOI 10.1002/app.10355     

The Simon effect occurs relative to the direction of an attention shift.

We investigated whether the Simon effect depends on the orienting of attention. In Experiment 1, participants were required to execute left-right discriminative responses to 2 patterns that were presented to the left or right of fixation. The 2 patterns were similar, and the discrimination was difficult. A letter at fixation signaled whether the current trial was a catch trial. The results showed a reversal of the Simon effect. That is, spatially noncorresponding responses were faster than spatially corresponding responses. In Experiment 2, the discrimination of the relevant stimulus attribute was easy. In Experiment 3, the discrimination of the relevant stimulus attribute was difficult, but the stimulus exposure time was long. In either experiment, the regular Simon effect was reinstated. In Experiment 4, the letter that signaled a catch trial appeared to the left or right of the imperative stimulus. The Simon effect occurred relative to the position of the letter. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ionomer composites based on sepiolite/hydrogenated poly(styrene butadiene) block copolymer systems

Ionomeric composites based on sepiolite and hydrogenated poly(styrene butadiene) block copolymer were obtained and characterized from a microstructural and electrical point of view. Before blending, because of the high silanol group concentration in the sepiolite, the latter could be organophilized with suitable coupling agents. The resulting materials were easily processed into thin films or membranes 0.2–0.4 mm thick, their conductivity in some cases approaching 10^?1 S/cm. Their suitability for film formation and good electrical properties indicate potential applications as electrolytes in polymer fuel cells. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3512–3519, 2002     

Primary lymphoma of the breast. Three cases of non-Hodgkin lymphoma

Primary and sole breast lymphoma is a very rare disease. With the review of our series of 616 cases operated on for breast cancer, only 3 cases (0.48%) of primary breast non-Hodgkin lymphoma (LNH) have been observed. The authors outline the problems concerning diagnosis and therapy of this rare disease: pathological and immunohistochemical aspects are discussed. They stress the importance of staging in order to plan a correct multidisciplinary approach.     

Feminist identity and feminist therapy behaviors of women psychotherapists.

Investigated whether (1) feminist identity development for women therapists was related to their use of feminist therapy behaviors (FTBs) and (2) feminist identity development and use of FTBs for women therapists were related to self-identification as a feminist therapist. 153 women psychologists (aged 30–77 yrs) were administered a women's issues in therapy questionnaire, which included a short version of the Feminist Identity Scale (FIS; K. M. Rickard, 1989, 1990). Ss were categorized into stages of feminine identity development according to their scores on 4 subscales of the FIS: Passive-Acceptance (PA), Revelation (REV), Embeddedness (EMB), and Synthesis (SYN). Ss scoring high on SYN and REV, and low on PA, reported greater use of FTBs; scores on the EMB were not related to the use of FTBs. All 4 subscales were predictive of women therapists who self-identified as feminist therapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)