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Individual Specimens (individual + specimen)
Selected AbstractsGenetic alterations of protein-o-mannosyltransferase-1 in glioneuronal and glial brain tumors with subarachnoid spreadNEUROPATHOLOGY, Issue 2 2009Julia Snoei Leptomeningeal spread is a casual but conspicuous finding in both low- and high-grade gliomas. We hypothesized a compromised integrity of the glia limitans-basal lamina complex due to glycosylation defects by loss of protein-o-mannosyltransferase-1 (POMT1) activity, also a well-known feature in developmental brain disorders with leptomeningeal heterotopia. Hypothesizing it as analogous in gliomas, we have performed a comprehensive polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of the POMT1 gene in 41 brain tumor specimens. Each specimen was subjected to laser capture microdissection analyses to dissect: (i) subarachnoid tumor components; (ii) deeply localized tumor areas; and (iii) histologically unaffected CNS fragments. In addition, leukocyte DNA of healthy Caucasians served as controls (n = 100). Sequence alterations were found in exons 7, 9, 15 and 18. Exon 7 bore two sequence alterations, one 751C > T transition with amino acid exchange of arginine by tryptophane (Arg251Trp) (n = 12/41 in Tu vs n = 7/82 in Co) and a 752G > A transition with replacement of arginine by glutamine (Arg251Gln) (n = 3/41 in Tu vs n = 0/82 in Co) that were significantly increased in the tumor specimens compared to controls (P < 0.05). A 979G > A transition in exon 9 resulted in a valine to isoleucine switch (Val327Ile) (n = 6/40 in Tu vs n = 4/84 in Co). Individual specimens revealed a 1565G > A (Arg522Lys) transition in exon 15 and a 1922C > T (Ala641Val) transition in exon 18. Two gangliogliomas only revealed sequence alterations in the superficial area but not in intraparenchymal and adjacent control specimens. We conclude that a significant increase of POMT1 missense mutations may indicate a functional role in neoplastic conditions in individual tumors. Future studies will be important to evaluate a functional impact of POMT1 alterations in human brain tumors. [source] The effect of Coca-Cola and fruit juices on the surface hardness of glass,ionomers and ,compomers'JOURNAL OF ORAL REHABILITATION, Issue 11 2004M. Aliping-McKenzie summary, The interaction of tooth-coloured dental restorative materials (a conventional glass,ionomer, two resin-modified glass,ionomers and two compomers) with acidic beverages has been studied with the aim of investigating how long-term contact affects solution pH and specimen surface hardness. For each material (ChemFil Superior, ChemFlex, Vitremer Core Build-Up/Restorative, Fuji II LC, Dyract AP and F2000) disc-shaped specimens were prepared and stored in sets of six in the following storage media: 0·9% NaCl (control), Coca-Cola, apple juice and orange juice. After time intervals of 1 day, 1 week, 1 month, 3 months, 4 months, 6 months and 1 year, solution pH and Vickers Hardness Number were determined for each individual specimen. Differences were analysed by anova followed by Student,Newman,Keuls post hoc analysis. All materials were found to reduce the pH of the 0·9% NaCl, but to increase the pH of the acidic beverages. The conventional glass,ionomers dissolved completely in apple juice and orange juice, but survived in Coca-Cola, albeit with a significantly reduced hardness after 1 year. The other materials survived in apple juice and orange juice, but showed greater reductions in surface hardness in these beverages than in Coca-Cola. Fruit juices were thus shown to pose a greater erosive threat to tooth coloured materials than Coca-Cola, a finding which is similar to those concerning dentine and enamel towards these drinks. [source] Should biomass be considered more frequently as a currency in terrestrial arthropod community analyses?JOURNAL OF APPLIED ECOLOGY, Issue 2 2007MICHEL SAINT-GERMAIN Summary 1Community structure involving large taxonomical groups is frequently used to assess changes in ecosystems along environmental gradients or in response to disturbance. For terrestrial arthropods, abundance is generally used as the response variable in community data analyses; biomass, however, is generally a better indicator of the functionality of a species within a community, as it is strongly correlated with metabolism. 2In this study, we considered whether biomass should be used more often in community analyses with terrestrial arthropod biodiversity data, particularly when asking questions involving strong functional components. We selected 10 previously published and five unpublished Coleoptera abundance data sets, and produced biomass species-by-sample matrices using body length to body mass conversion equations, and then compared the results obtained using commonly used ecological analyses. 3Correlations between species abundance and biomass varied from strong to poor, depending on the taxa considered and on the sampling method used. We show that abundance and biomass can produce different results in community data analysis and lead to alternative interpretations for data sets with poor abundance to biomass correlations. 4Synthesis and applications. When dealing with databases showing poor abundance to biomass relationships, the question of the relevance of using biomass instead of abundance emerges, and the choice of the response variable to be used in analyses should be considered carefully. At the very least, when studying terrestrial arthropod biodiversity, one should consider the use of biomass with simple conversion equations that do not require obtaining the mass of individual specimens. This approach may lead to different interpretations. For research questions in which trophic interactions may play an important role, biomass may provide a broader and more accurate picture of the processes driving changes in community structure. [source] IN FOCUS: Activation of platelets by heparin-induced thrombocytopenia antibodies in the serotonin release assay is not dependent on the presence of heparinJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2005M. M. PRECHEL Summary., The serotonin release assay (SRA) tests for antibodies responsible for heparin-induced thrombocytopenia (HIT). By definition, SRA-positive antibodies cause platelet serotonin release in vitro, in the presence of low concentrations of heparin, but not with excess heparin. Many SRA-positive sera activate platelets in the presence of saline without drug, either as a result of residual heparin in the specimen, or because of intrinsic features of the HIT antibodies. The present experiments show that neither exhaustive heparinase treatment, nor chromatographic removal of heparin abrogates the spontaneous platelet activation caused by these HIT antibodies. This is the first study to systematically demonstrate that in vitro activity of HIT antibodies can be independent of heparin. In addition, T-gel chromatography demonstrated differences among fractions of enzyme-linked-immunosorbent assay (ELISA)-positive HIT antibodies within individual specimens. Certain ELISA-positive fractions had SRA activity while others did not, and the SRA activity was not proportional to HIT antibody ELISA titer. These data suggest that antibodies formed as a result of heparin treatment are heterogeneous, and that some can contribute to the pathogenesis of HIT even when heparin is no longer present. [source] A geometric morphometric analysis of the shape of the first upper molar in mice of the genus Mus (Muridae, Rodentia)JOURNAL OF ZOOLOGY, Issue 4 2006M. Macholán Abstract Phenotypic variation in the shape of the first upper molar among 595 mice, representing nine extant and three extinct taxa of the genus Mus, was studied with thin-plate spline analysis. The reliability of classification of individual specimens into known groups based on their molars varied from 75 to 100%, depending on group and method used. Including 13 sliding semilandmarks to the analysis improved the detection of different kinds of size and shape variation as well as visualization of shape differences between studied groups. Correlation between phylogenetic and morphometric distances suggested about 80% contribution of phylogenetic inertia to the molar shape variation; moreover, the importance of localized versus global shape changes was similar in the detection of phylogenetic signals. Finally, shape changes along individual evolutionary lineages were revealed, suggesting a few cases of reversals, convergence and/or retention of ancestral shape. The evolution of mouse molars has thus been driven by random effects of drift together with stabilizing selection and convergence. [source] Gene trees: A powerful tool for exploring the evolutionary biology of species and speciationPLANT SPECIES BIOLOGY, Issue 3 2000Alan R. Templeton Abstract Evolutionary trees can be constructed from the haplotypes observed with molecular surveys of sequence or restriction site variation. Such gene trees can be constructed regardless of whether or not all of the individual specimens came from one or many species. Hence, these gene trees can straddle the species/population interface, thereby providing a powerful tool for studying the meaning of species and the process of speciation. We illustrate how historical approaches using gene trees can be used to separate the effects of population structure from population history, in order to rigorously test the species status of a group, and to test hypotheses about the process of speciation. A worked example of species status in the Piriqueta caroliniana complex is presented. Species status is evaluated under the cohesion species concept that defines a species as an evolutionary lineage with boundaries arising from the forces that create reproductive communities. Such forces are collectively called cohesion mechanisms and consist of two main subtypes: (i) genetic exchangeability, and (ii) ecological interchangeability. To make this definition operational, populations that behave as separate evolutionary lineages are first identified. A method is reviewed for inferring lineages using explicit statistical criteria from geographic overlays upon gene trees. Once lineages have been identified, the next step is to use the cohesion mechanisms to identify candidate traits that should contribute to genetic exchangeability and/or ecological interchangeability. The cohesion species are then identified by performing overlays upon gene trees in order to identify significant transitions in the candidate traits. Cohesion species are recognized only when statistically significant reproductive/ecological transitions occur that are concordant with the lineages defined earlier. This data-rich method of recognizing species automatically generates much information about the biogeography, population structure, historical events, and ecology and/or reproductive biology of the group under study. In turn, this information provides much insight into the process of speciation. It also makes the criteria, data, methods of analysis and degree of support for the species inference completely explicit, thereby avoiding confusion, inconsistency and artificial controversies that plague much of the literature on species concepts. [source] The expression of androgen-responsive genes is Up-Regulated in the epithelia of benign prostatic hyperplasiaTHE PROSTATE, Issue 16 2009Katherine J. O'Malley Abstract BACKGROUND Benign prostatic hyperplasia (BPH) is one of the most common diseases among aging men in the United States. In addition to aging, the presence of androgens is another major risk factor in BPH development. However, whether androgen signaling is altered in BPH remains unclear. To determine androgen signaling in BPH, we characterized the expression of four different androgen-responsive genes, Eaf2/U19, ELL2, FKBP5, and PSA, in BPH and adjacent normal glandular epithelial cells. METHODS A set of 17 BPH specimens were resected from patients over 60 years of age with clinical symptoms of BPH. Laser-capture microdissection (LCM) was used to isolate glandular epithelial cells from BPH areas and adjacent normal areas, separately. LCM isolated cells from individual specimens were lysed and RNA isolation, reverse transcription, and real-time PCR were performed using CellsDirectÔ One-Step qRT-PCR Kit (Invitrogen, Carlsbad, CA). RESULTS All of the assayed genes displayed increased expression, from ,2- to ,6-fold, in BPH as compared to the adjacent normal epithelial cells. We also generated a composite androgen response index based on the expression levels of the four genes, which provides a reliable readout for overall androgen action. Our study showed that the composite androgen response index in BPH is ,4-fold as compared to that in the adjacent normal tissues. CONCLUSIONS Androgen signaling is significantly elevated in BPH relative to the adjacent normal prostate. Understanding the mechanisms causing elevated androgen signaling may lead to novel approaches for prevention and/or treatment of BPH. Prostate 69: 1716,1723, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||