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941.
Yusuf Abou-Jawdah Hagop Atamian Georges Nemer Linda Kfoury Nancy Choukrallah Lucia Hanna 《Biocontrol Science and Technology》2008,18(6):573-581
A Lebanese isolate of a Beauveria species originally isolated from a hymenopterous insect pest was found to be very effective against the pine processionary moth Thaumetopoea wilkinsoni. In laboratory bioassays, high mortality rates of the five larval stages were attained with spore concentrations of about 5000–50,000 spores/larva. The efficacy of kill on the first three larval stages was similar to the growth regulator diflubenzuron, but it was significantly higher on the fourth and fifth larval stages. Sequences of the DNA lyase gene and the EF-1α gene were used for molecular characterisation of this Beauveria isolate. The DNA lyase gene showed more polymorphism than the previously reported ITS region and EF-1α gene. This constitutes the first report on the possibility of using the DNA lyase gene as a molecular tool in fungal taxonomy. 相似文献
942.
Georges Lorans James M. Phang 《Biochemical and biophysical research communications》1981,101(3):1018-1025
Pyrroline-5-carboxylate (P5C) reductase not only catalyzes the final step in proline biosynthesis but also mediates redox regulation. We examined these dual functions in human lymphoblastoid cell lines (REH, LHN13) one of which (REH) is deficient in proline synthesis. In spite of the deficiency in proline synthesis in REH, the PC-mediated redox effect was relatively intact. The dissociation of these functions was due to qualitative as well as quantitative differences in the REH enzyme relative to its utilization of NADPH and NADH. 相似文献
943.
944.
Joseph F. Georges Xiaowei Liu Jennifer Eschbacher Joshua Nichols Michael A. Mooney Anna Joy Robert F. Spetzler Burt G. Feuerstein Mark C. Preul Trent Anderson Hao Yan Peter Nakaji 《PloS one》2015,10(4)
Improved tools for providing specific intraoperative diagnoses could improve patient care. In neurosurgery, intraoperatively differentiating non-operative lesions such as CNS B-cell lymphoma from operative lesions can be challenging, often necessitating immunohistochemical (IHC) procedures which require up to 24-48 hours. Here, we evaluate the feasibility of generating rapid ex vivo specific labeling using a novel lymphoma-specific fluorescent switchable aptamer. Our B-cell lymphoma-specific switchable aptamer produced only low-level fluorescence in its unbound conformation and generated an 8-fold increase in fluorescence once bound to its target on CD20-positive lymphoma cells. The aptamer demonstrated strong binding to B-cell lymphoma cells within 15 minutes of incubation as observed by flow cytometry. We applied the switchable aptamer to ex vivo xenograft tissue harboring B-cell lymphoma and astrocytoma, and within one hour specific visual identification of lymphoma was routinely possible. In this proof-of-concept study in human cell culture and orthotopic xenografts, we conclude that a fluorescent switchable aptamer can provide rapid and specific labeling of B-cell lymphoma, and that developing aptamer-based labeling approaches could simplify tissue staining and drastically reduce time to histopathological diagnoses compared with IHC-based methods. We propose that switchable aptamers could enhance expeditious, accurate intraoperative decision-making. 相似文献
945.
Demographic analysis of cemetery data can be a useful complement to archaeological studies. Skeletal remains, when they comprise a representative sample, can serve to define certain relationships between the cultural and biological aspects of human adaptation. Furthermore, differential mortuary practices often mirror the status system of a society.Specifically, this paper examines the status system and mortality pattern of the community of Meinarti in the Sudan. Stationary life table analysis shows age, sex, and an additional factor (reflected in survival) as determinants of status. In addition, the analysis of mortality supports Adam's hypothesis of village growth and decline. 相似文献
946.
The potential kinetic complexity of polymeric regulatory enzymes does not seem to be often expressed in nature. Most of these enzymes exhibit in fact a rather simple kinetic behaviour. This functional simplicity is probably the consequence of constraints between rate constants or of blocking of some reaction steps. Functional simplicity is believed to have emerged in the course of neo-Darwinian evolution as a consequence of a trend towards an improved functional efficiency. Functional efficiency may be reached, in polymeric regulatory enzymes, when either of the two sets of conditions are met. The first set of conditions implies the occurrence of the unicity of enzyme conformation in any transition state, a loose coupling between subunits and an exact balance of the driving forces exerted by the enzyme in the forward and backward directions of the catalytic step. This situation results in constraints between rate constants which allow degenerescence of the steady state rate equation. The second set of conditions involves again the unicity of enzyme conformation in any of the transition states, associated with a tight coupling of subunits, and a driving force exerted by the enzyme much strongly in the forward than in the backward direction of the catalytic step. These conditions imply blocking of some reaction steps and again degenerescence of the corresponding rate equation. The most frequent types of quaternary structure and subunit interactions, namely loose coupling between subunits, and tight coupling associated with conservation of at least one symmetry axis, have probably emerged as molecular organizations, which precisely allow both functional efficiency and simplicity to occur. Indeed these situations probably represent the term of two different evolutionary trends. Therefore enzymes that have not reached this state usually exhibit more complex kinetic behaviour. Wavy curves, “bumps” and turning points may be considered as manifestations of the ancestral character of an enzyme. 相似文献
947.
948.
949.
Pelargonidin 3-malonylsophoroside was characterized as a flower pigment in a red form of the Iceland poppy, Papaver nudicaule. 相似文献
950.
Mathieu Tramoni Jerome Gilleron Khadija Tahiri Diane Carette Marie-Therese Corvol Dominique Segretain Georges Pointis Jean-Francois Savouret 《Biochimie》2009,91(11-12):1366-1375
The potential health impact of pharmaceutical waste is now a growing concern. Contraceptive steroids are prominent environmental contaminants and thus may act as endocrine disruptors. Numerous xenobiotics hamper Sertoli cells junctional communication which is known to participate in spermatogenesis control. This has been associated with male subfertility and testicular cancer. We investigated three contraceptive molecules found in the environment for their potential impact on Sertoli cells gap junction functionality: 17a-ethynylestradiol, medroxyprogesterone acetate and levonorgestrel. Four other non-steroid drugs also found in the environment were included in the study. Communication disruption was analyzed in vitro in murine seminiferous tubules and the 42GPA9 Sertoli cell line. Steroids modulated connexin43 trafficking and impaired junctional communication through rapid effects apparently acting on the cell membrane but not on Cx43 expression. The 4 non-steroid compounds showed no effect. Longer exposure to steroids increased gap junction impairment, which was associated in part with Na/K ATPase internalization. Estrogen receptors (ER) did not appear to be involved in gap junction disruption: Sertoli cells are devoid of ERα and only express the cytoplasmic β isoform. ERβ localization was not modified by either steroid. The threshold level was surprisingly low, around 10?16 M. We conclude that steroidal pollutants disrupt Sertoli cells junctional communication in vitro at concentrations that can be found in the environment. 相似文献