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The article presents recommended guidelines for a standardized approach to sample submission, tissue trimming, margin evaluation and reporting of tumor biopsies in veterinary surgical pathology. It stresses the importance of the pathology report in determining prognosis, therapeutic decisions, and overall case management. It notes that the guidelines, prepared under the auspices of the American College of Veterinary Pathologists Oncology Committee, should be viewed as an evolving document requiring continuous revision.

ABSTRACT: Villin-type headpiece domains are compact F-actin-binding motifs that have been used extensively as a model system to investigate protein folding by both experimental and computational methods. Villin headpiece (HP67) harbors a highly helical, thermostable, and autonomously folding subdomain in the C terminus (HP35), and because of this feature, HP67 is usually considered to be composed of a N- and C-terminal subdomain. Unlike the C-terminal subdomain, the N-terminal subdomain consists mainly of loops and turns, and the folding is dependent upon the presence of the C-terminal subdomain. The pH sensitivity of this subdomain is thought to arise from, at least partially, protonation of H41 buried in the hydrophobic core. Substitution of this histidine with tyrosine, another permissive residue at this position for naturally occurring sequences, increases not only the pH stability of HP67 but also the thermal stability and the cooperativity of thermal unfolding over a wide pH range (0.9-7.5). The crystal structures of wild-type HP67 and the H4 I Y mutant, determined under the same conditions, indicate that the H4IY substitution causes only localized rearrangement around the mutated residue. The F-actin- binding motif remains essentially the same after the mutation, accounting for the negligible effect of the mutation on F-actin affinity. The hydrogen bond formed between the imidazole ring of H4l and the backbone carbonyl of E14 of HP67 is eliminated by the H4IY mutation, which renders the extreme N terminus of H41Y more mobile; the hydrogen bond formed between the irnidazole ring of H41 and the backbone nitrogen of D34 is replaced with that between the hydroxyl group of Y4 I and the backbone nitrogen of D34 after the H4IY substitution. The increased hydrophobicity of tyrosine compensates for the loss of hydrogen bonds in the extreme N terminus and accounts for the increased stability and cooperativity of the H4IY mutant. [ABSTRACT FROM AUTHOR]

The article summarizes a survey of syringe exchange programs (SEP) in the U.S. in 2005 and compares the findings with other SEP surveys conducted in 2000 and 2004. The survey included questions concerning the number of syringes exchanged, the types of services offered and budgets and funding provided in 2005. The survey was conducted in California, New Mexico and Washington, among others. The indications and limitations of the survey findings are elaborated.

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Small autonomously folding proteins are of interest as model systems to study protein folding, as the same molecule can be used for both experimental and computational approaches. The question remains as to how well these minimized peptide model systems represent larger native proteins. For example, is the core of a minimized protein tolerant to mutation like larger proteins are? Also, do minimized proteins use special strategies for specifying and stabilizing their folded structure? Here we examine these questions in the 35-residue autonomously folding villin headpiece subdomain (VHP subdomain). Specifically, we focus on a cluster of three conserved phenylalanine (F) residues F47, F51, and F58, that form most of the hydrophobic core. These three residues are oriented such that they may provide stabilizing aromatic-aromatic interactions that could be critical for specifying the fold. Circular dichroism and 1D-NMR spectroscopy show that point mutations that individually replace any of these three residues with leucine were destabilized, but retained the native VHP subdomain fold. In pair-wise replacements, the double mutant that retains F58 can adopt the native fold, while the two double mutants that lack F58 cannot. The folding of the double mutant that retains F58 demonstrates that aromatic-aromatic interactions within the aromatic cluster are not essential for specifying the VHP subdomain fold. The ability of the VHP subdomain to tolerate mutations within its hydrophobic core indicates that the information specifying the three dimensional structure is distributed throughout the sequence, as observed in larger proteins. Thus, the VHP subdomain is a legitimate model for larger, native proteins. [ABSTRACT FROM AUTHOR]

This article describes a survey investigating the opinions of children's librarians on the subject of electronic books. A questionnaire was sent by post to those responsible for public library services for children at each of the 208 local government authorities in the UK. The response rate was 77 per cent. Notable conclusions include the fact that there was a positive attitude towards including electronic books as part of the children's library service, and a high proportion of libraries offered access to them, the majority through main libraries. A small majority of libraries were offering electronic books for reference use within the library, rather than lending them out like printed books. Many of the librarians believed that electronic books can attract new members to the library, and that offering electronic books will change their role. Respondents believed that electronic books are durable, and can exist alongside the printed items within the library. [ABSTRACT FROM AUTHOR]

Arc repressor bearing the N11L substitution (Arc-N11L) is an evolutionary intermediate between the wild type protein, in which the region surrounding position 11 forms a β-sheet, and a double mutant `switch Arc', in which this region is helical. Here, Arc-N11L is shown to be able to adopt either the wild type or mutant conformations. Exchange between these structures occurs on the millisecond time scale in a dynamic equilibrium in which the relative populations of each fold depend on temperature, solvent conditions and ligand binding. The N11L mutation serves as an evolutionary bridge from the β-sheet to the helical fold because in the mutant, Leu is an integral part of the hydrophobic core of the new structure but can also occupy a surface position in the wild type structure. Conversely, the polar Asn 11 side chain serves as a negative design element in wild type Arc because it cannot be incorporated into the core of the mutant fold. [ABSTRACT FROM AUTHOR]

Recent interest in ethical pluralism derives from Isaiah Berlin's reflections on the writings of Vico and Herder and their opposition to the views of the Enlightenment. I begin with two quotations from Berlin:It (pluralism) is not relativism. Members of one culture can, by the force of imaginative insight, understand … the values, the ideals, the forms of life of another culture or society, even those remote in time or space. They may find these values unacceptable, but if they open their minds sufficiently they can grasp how one might be a full human being, with whom one could communicate, and at the same time live in the light of values widely different from one's own, but which nevertheless one can see to be values, ends of life, by the realisation of which men could be fulfilled. (Berlin, 1991, p. 10) [ABSTRACT FROM PUBLISHER]