Ovarian cancer-associated lymphocyte recognition of folate binding protein peptides

BACKGROUND: Tumor-associated lymphocytes (TAL) isolated from ovarian cancer patients contain cytotoxic T lymphocytes (CTL) capable of recognizing specific HLA/peptide complexes on tumor cells leading to tumor cell lysis. Currently, HER2/neu, overexpressed in only 30% of breast and ovarian cancers, is the only known source of CTL-recognized peptides in epithelial cancers. Therefore, we have investigated peptides derived from folate binding protein (FBP), which is over-expressed in more than 90% of ovarian cancers and in the majority of other epithelial tumors. METHODS: TAL were isolated from the malignant ascites of four consecutive HLA-A2+ ovarian cancer patients and incubated in IL-2. Initial chromium-release assays were performed within 1 week. T2 cells, incubated with peptide, were used to reconstitute T cell epitopes. The FBP sequence was interrogated for HLA-A2 binding peptides, and five were synthesized (E37-41). RESULTS: Freshly cultured, unstimulated ovarian TAL recognize peptides derived from FBP. These peptides are presented in the context of HLA-A2, and are specifically recognized in a HLA class I-restricted fashion. TAL recognition of these reconstituted T cell epitopes is concentration dependent. Furthermore, the FBP peptides are shown by cold target inhibition studies to be naturally processed and presented antigens. CONCLUSIONS: FBP peptides are recognized by freshly isolated TAL from ovarian cancer patients, suggesting in vivo expression and sensitization. Because FBP is over-expressed 20-fold in most adenocarcinomas, these peptides may be used in a widely applicable peptide-based vaccine for epithelial tumors.     

A study of the effect of styrene concentration on the molecular weight of polypropylene produced using metallocene catalysts

It has been observed in the production of polypropylene nanocomposites containing silicate materials that the molecular weight of the polymer used can have a significant effect on the final quality of the composites. The availability of polypropylene over a range of molecular weights with similar material properties (e.g. melting temperature and tacticity) is limited. Therefore, the ability to use a single catalyst system to generate polypropylene with a range of molecular weights is an attractive goal. In this contribution the use of styrene as a chain‐terminating agent is explored, in order to produce materials with a range of molecular weights from a single catalyst system. It is found that the molecular weight of the polypropylene produced can be varied in the range from 120 000 to 9000 g mol^?1 using the Me₂Si(Ind)₂ZrCl₂/methylaluminoxane catalyst system. Copyright © 2011 Society of Chemical Industry     

Can the Synchrony of Nitrogen Supply and Crop Demand be Improved in Legume and Fertilizer-based Agroecosystems? A Review

Asynchrony between nitrogen (N) supply and crop demand is the source of many environmental hazards associated with excess N in the biosphere. In this review, we explore some of the complexity of the synchrony issue in agroecosystems that obtain N via legume rotations or synthetic fertilizers. Studies that have simultaneously compared the fate of both sources of N suggest that in rainfed agricultures, crops recover more N from fertilizer, but a higher proportion of the legume N is retained in the soil and N losses tend not to differ greatly from either source. However, investigations from irrigated cropping systems indicate that legume N is generally less susceptible to loss processes than fertilizers. Such general conclusions need to be qualified by acknowledging that not all comparative studies have used ȁ8best management practices’ when applying the fertilizer or legume residues. When information-intensive management approaches are used, fertilizer-based systems can potentially out-perform the synchrony achieved by legume-based rotations. We suggest that the inclusion of perennials in cropping systems may hold the greatest promise for decreasing the risk of N losses in future farming systems.     

Mg2+ inhibition of ATP-activated current in rat nodose ganglion neurons: evidence that Mg2+ decreases the agonist affinity of the receptor

The effect of Mg2+ on ATP-activated current in rat nodose ganglion neurons was investigated with the use of the whole cell patch-clamp technique. Mg2+ decreased the amplitude of ATP-activated current in a concentration-dependent manner over the concentration range of 0.25-8 mM, with a 50% inhibitory concentration value of 1.5 mM for current activated by 10 microM ATP. Mg2+ shifted the ATP concentration-response curve to the right in a parallel manner, increasing the 50% effective concentration value for ATP from 9.2 microM in the absence of added Mg2+ to 25 microM in the presence of 1 mM Mg2+. Mg2+ increased the deactivation rate of ATP-activated current without changing its activation rate. The observations are consistent with an action of Mg2+ to inhibit ATP-gated ion channel function by decreasing the affinity of the agonist binding site on these receptors.     

Phasic firing of single neurons in the rat nucleus accumbens correlated with the timing of intravenous cocaine self-administration

To examine potential neural mechanisms involved in cocaine self-administration, the activity of single neurons in the nucleus accumbens of rats was recorded during intravenous cocaine self-administration. Lever pressing was reinforced according to a fixed-ratio 1 schedule. On a time base comparable to the interinfusion interval, half the neurons exhibited phasic firing patterns time locked to the cocaine reinforced level press. For almost all neurons, this pattern consisted of a change in firing rate postpress, typically a decrease, followed by a reversal of that change. The postpress change was closely related to the lever press. Typically, it began within the first 0.2 min postpress and culminated within the first 1.0 min postpress. For a small portion of responsive neurons, the reversal of the postpress change was punctate and occurred within 1-3 min of either the last lever press or the next lever press so that firing was stable during much of the interinfusion interval. For the majority of neurons, the reversal was progressive; it began within 2 min after the previous level press, and it was not complete until the last 0.1-2.0 min before the next lever press. The duration of this progressive reversal, but not of the postpress change, was positively correlated with the interinfusion interval. Thus, in addition to exhibiting changes in firing related to the occurrence of self-infusion, the majority of neurons also exhibited progressive changes in firing related to the spacing of infusions. In a structure that has been shown to be necessary for cocaine self-administration, such a firing pattern is a likely neurophysiological component of the mechanism that transduces declining drug levels into increased drug-related appetitive behavior. It is, thus, a neural mechanism that may contribute to compulsive drug-maintained drug taking.     

Coexistence of Low Damping and Strong Magnetoelastic Coupling in Epitaxial Spinel Ferrite Thin Films

Low‐loss magnetization dynamics and strong magnetoelastic coupling are generally mutually exclusive properties due to opposing dependencies on spin–orbit interactions. So far, the lack of low‐damping, magnetostrictive ferrite films has hindered the development of power‐efficient magnetoelectric and acoustic spintronic devices. Here, magnetically soft epitaxial spinel NiZnAl‐ferrite thin films with an unusually low Gilbert damping parameter (<3 × 10^?3), as well as strong magnetoelastic coupling evidenced by a giant strain‐induced anisotropy field (≈1 T) and a sizable magnetostriction coefficient (≈10 ppm), are reported. This exceptional combination of low intrinsic damping and substantial magnetostriction arises from the cation chemistry of NiZnAl‐ferrite. At the same time, the coherently strained film structure suppresses extrinsic damping, enables soft magnetic behavior, and generates large easy‐plane magnetoelastic anisotropy. These findings provide a foundation for a new class of low‐loss, magnetoelastic thin film materials that are promising for spin‐mechanical devices.     

Black and White student preferences for counselor roles.

28 Black and 28 White students from 2 university programs viewed a brief videotape of a counseling sesson in 1 of 4 conditions defined by (a) 2 female counselors (1 Black, 1 White); and (b) 2 counselor roles (active, passive). Analysis of Ss' ratings of counselor performances reveal (a) no differences among conditions in perceived attentiveness or friendliness; (b) significant differences between roles in perceptions of counselor behavior (as intended); (c) significantly higher ratings of competence and helpfulness for counselors in the active vs the passive role, regardless of counselor or S role; and (d) a main effect for counselor, which could not be unequivocally attributed either to counselor role performance or to counselor role. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)