Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery.     

Phylogenetics of the brachyuran crabs (Crustacea: Decapoda): the status of Podotremata based on small subunit nuclear ribosomal RNA

The true crabs, the Brachyura, are generally divided into two major groups: Eubrachyura or 'advanced' crabs, and Podotremata or 'primitive' crabs. The status of Podotremata is one of the most controversial issues in brachyuran systematics. The podotreme crabs, best recognised by the possession of gonopores on the coxae of the pereopods, have variously been regarded as mono-, para- or polyphyletic, or even as non-brachyuran. For the first time, the phylogenetic positions of the podotreme crabs were studied by cladistic analysis of small subunit nuclear ribosomal RNA sequences. Eight of 10 podotreme families were represented along with representatives of 17 eubrachyuran families. Under both maximum parsimony and Bayesian Inference, Podotremata was found to be significantly paraphyletic, comprising three major clades: Dromiacea, Raninoida, and Cyclodorippoida. The most 'basal' is Dromiacea, followed by Raninoida and Cylodorippoida. Notably, Cyclodorippoida was identified as the sister group of the Eubrachyura. Previous hypotheses that the dromiid crab, Hypoconcha, is an anomuran were unsupported, though Dromiidae as presently composed could be paraphyletic. Topologies constrained for podotreme monophyly were found to be significantly worse (P < 0.04) than unconstrained topologies under Templeton and S-H tests. The clear pattern of podotreme paraphyly and robustness of topologies recovered indicates that Podotremata as a formal concept is untenable. Relationships among the eubrachyurans were generally equivocal, though results indicate the majoids or dorippoids were the least derived of the Eubrachyura. A new high level classification of the Brachyura is proposed.     

Verification of endometrial tissue biomarkers previously discovered using mass spectrometry-based proteomics by means of immunohistochemistry in a tissue microarray format

Verification of candidate protein biomarkers is a necessary step in moving from the initial discovery to application. Here, we report results of a verification exercise involving six candidate endometrial cancer biomarkers previously discovered using mass-tagging and multidimensional liquid chromatography/tandem mass spectrometry (DeSouza L., et al. J. Proteome Res. 2005, 4, 377-386) on a cohort of 148 patient samples by means of immunohistochemistry on a tissue microarray format. A panel of the three best-performing biomarkers, chaperonin 10, pyruvate kinase M2, and alpha-1-antitrypsin, achieved a sensitivity of 0.85, specificity of 0.93, predictive value of 0.90, and positive predictive value of 0.88 in discriminating malignant from benign endometrium. The ruggedness of this panel of biomarkers was verified in a 2/3-training-set-1/3-test-set cross-validation analysis by randomly splitting the cohort in 10 ways. The roles of chaperonin 10 and pyruvate kinase M2 in tumorigenesis confirm them as credible cancer biomarkers.     

Resolvin D1 and its aspirin-triggered 17R epimer. Stereochemical assignments, anti-inflammatory properties, and enzymatic inactivation

We recently uncovered two new families of potent docosahexaenoic acid-derived mediators, termed D series resolvins (Rv; resolution phase interaction products) and protectins. Here, we assign the stereochemistry of the conjugated double bonds and chirality of alcohols present in resolvin D1 (RvD1) and its aspirin-triggered 17R epimer (AT-RvD1) with compounds prepared by total organic synthesis. In addition, docosahexaenoic acid was converted by a single lipoxygenase in a "one-pot" reaction to RvD1 in vitro. The synthetic compounds matched the physical and biological properties of those enzymatically generated. RvD1 proved to be 7S,8R,17S-trihydroxy-4Z,9E,11E,13Z,15E,19Z-docosahexaenoic acid, AT-RvD1 matched 7S,8R,17R-trihydroxy-4Z,9E,11E,13Z,15E,19Z-docosahexaenoic acid, and they both stopped transendothelial migration of human neutrophils (EC(50) approximately 30 nM). In murine peritonitis in vivo, RvD1 and AT-RvD1 proved equipotent (at nanogram dosages), limiting polymorphonuclear leukocyte infiltration in a dose-dependent fashion. RvD1 was converted by eicosanoid oxidoreductase to novel 8-oxo- and 17-oxo-RvD1 that gave dramatically reduced bioactivity, whereas enzymatic conversion of AT-RvD1 was sharply reduced. These results establish the complete stereochemistry and actions of RvD1 and AT-RvD1 as well as demonstrate the stereoselective basis for their enzymatic inactivation. RvD1 regulates human polymorphonuclear leukocyte transendothelial migration and is anti-inflammatory. When its carbon 17S alcohol is enzymatically converted to 17-oxo-RvD1, it is essentially inactive, whereas the 17R alcohol configuration in its aspirin-triggered form (AT-RvD1) resists rapid inactivation. These results may contribute to the beneficial actions of aspirin and omega-3 fish oils in humans.     

Molecular phylogeography of the fruit bat genus Melonycteris in northern Melanesia

Aim To investigate patterns of genetic divergence between populations of the fruit bat genus Melonycteris Dobson 1877 in relation to the possible effects on dispersal of the geological history of water barriers within and between northern Melanesian archipelagos. Location The genus is found only in the Bismarck Archipelago and Solomon Islands of northern Melanesia. Methods Up to 935 aligned bases of cytochrome b and cytochrome c oxidase subunit I DNA sequences were determined for specimens of most species and subspecies of Melonycteris. Measures of genetic distance, analysis of molecular variation and phylogenetic investigations (using maximum parsimony, maximum likelihood and Bayesian approaches) were conducted to assess the evolutionary relationships amongst populations. Results The deepest divergences within Melonycteris separate the genus into two reciprocally monophyletic clades from first, the Bismarck Archipelago, and secondly, the Solomon Islands. Within the Solomon Islands, five major clades received strong support. Listed in a generally north‐western to south‐eastern direction these were: (1) specimens from Choiseul and Santa Isabel; (2) specimens from New Georgia and Kolombangara; (3) specimens from Malaita; (4) specimens from Guadalcanal; and (5) specimens from Makira. Outgroup rooting suggested that the clade from Makira was the most basal within the Solomon Islands, being shown as the sister group to all other Melonycteris from this archipelago. Main conclusions Patterns of genetic variation within Melonycteris were generally consistent, given current knowledge of northern Melanesian geological history, with the hypothesis that the dispersal of these fruit bats is strongly inhibited by water barriers. Within the Solomon Islands the main genetic clades were each restricted to a single island or to a group of islands that are thought to have belonged to larger landmasses (Greater Gatumbangara and Greater Bukida) formed by land bridges during the Pleistocene. The high genetic distance between specimens from the Bismarck Archipelago and from the Solomon Islands reflects the persistently large geographic distance between these archipelagos. The unexpected phylogenetic position of the Makira specimens suggests either that this island was the first colonized by Melonycteris in the Solomon Islands or that this population is the relict of a clade that was previously more widely distributed.     

Marsupial MHC class II beta genes are not orthologous to the eutherian beta gene families

The major histocompatibility complex (MHC) class II DRB, DQB, DPB, and DOB gene clusters are shared by different eutherian orders. Such an orthologous relationship is not seen between the beta genes of birds and eutherians. A high degree of uncertainty surrounds the evolutionary relationship of marsupial class II beta sequences with eutherian beta gene families. In particular, it has been suggested that marsupials utilize the DRB gene cluster. A cDNA encoding an MHC class II beta molecule was isolated from a brushtail possum mesenteric lymph node cDNA library. This clone is most similar to Macropus rufogriseus DBB. Our analysis suggests that all known marsupial beta-chain genes, excluding DMB, fall into two separate clades, which are distinct from the eutherian DRB, DQB, DPB, or DOB gene clusters. We recommend that the DAB and DBB nomenclature be reinstated. DAB and DBB orthologs are not present in eutherians. It appears that the marsupial and eutherian lineages have retained different gene clusters following gene duplication events early in mammalian evolution.     

Dileucine motif is sufficient for internalization and synaptic vesicle targeting of vesicular acetylcholine transporter

Efficient cholinergic transmission requires accurate targeting of vesicular acetylcholine transporter (VAChT) to synaptic vesicles (SVs). However, the signals that regulate this vesicular targeting are not well characterized. Although previous studies suggest that the C-terminus of the transporter is required for its SV targeting, it is not clear whether this region is sufficient for this process. Furthermore, a synaptic vesicle-targeting motif (SVTM) within this sequence remains to be identified. Here we use a chimeric protein, TacA, between an unrelated plasma membrane protein, Tac, and the C-terminus of VAChT to demonstrate the sufficiency of the C-terminus for targeting to synaptic vesicle-like vesicles (SVLVs) in PC12 cells. TacA shows colocalization and cosedimentation with the SV marker synaptophysin. Deletion mutation analysis of TacA demonstrates that a short, dileucine motif-containing sequence is required and sufficient to direct this targeting. Dialanine mutation analysis within this sequence suggests indistinguishable signals for both internalization and SV sorting. Using additional chimeras as controls, we confirm the specificity of this region for SVLVs targeting. Therefore, we suggest that the dileucine-containing motif is sufficient as a dual signal for both internalization and SV targeting during VAChT trafficking.