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971.
Michal Zeman Peter Skrobanek Monika Okuliarova 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2013,164(2):271-275
Maternally-derived yolk androgens exhibit distinct among- and within-female variations but limited data refer to inter-seasonal changes of maternal hormones in the yolk. We investigated the deposition of yolk testosterone (T) across two laying cycles in Japanese quail. To test how genetically-determined differences influence between cycle variations in yolk androgens we compared females from low (LET) and high (HET) egg T lines at the end of the first and at the beginning of the second laying cycle after an induced moult. Line differences in yolk T levels exhibited high consistency exceeding two reproductive cycles. Yolk T concentrations increased in the second laying cycle in HET but not in LET females. Plasma T levels did not differ between cycles in both lines and no line differences were found either before or after the moult indicating the presence of mechanisms limiting the increase of T concentrations in the circulation. Differences in the yolk T levels were not accompanied by changes in the egg and yolk mass. The HET quail laid eggs with heavier eggshell than the LET quail. Our results demonstrate different abilities of mothers to deposit T in their eggs over two reproductive seasons with expected consequences on the development of their progeny. 相似文献
972.
Andrew J. Kirby Regis Le Lain Farshid Maharlouie Peter Mason Paul J. Nicholls H. John Smith 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):27-33
In a search for inhibitors of all-trans retinoic acid (RA)-metabolising enzymes as potential agents for the treatment of skin conditions and cancer we have examined 2-(4-aminophenylmethyl)-6-hydroxy-3,4-dihydronaphthalen-1(2H)-one (5). Compound (5) is a moderate inhibitor of RA-metabolising enzymes in mammalian cadaverous tissue microsomes and homogenates as well as RA-induced enzymes in cultured human genital fibroblasts and HaCat cells. Overall (5) was more potent than or equipotent with ketoconazole, a standard inhibitor, in the cadaverous systems but less active towards the RA-induced cell culture systems. Examination of the data suggests that RA-induction generates metabolising enzymes not present in the cadaverous systems, which are more susceptible to inhibition by ketoconazole than (5). 相似文献
973.
Abstract 5-(N-Hydroxy) carboxamidouridine (5) and 5-(N-hydroxy) carboxamido-methyluridine (6) have been synthesized; these hydroxamic acids incorporate a radical trap into a nucleoside structure, and are designed as potential inhibitors of ribonucleotide diphosphate reductase. 相似文献
974.
Abstract The synthesis of phosphoramidites (2 and 3) derived from hypoxanthine and isoguanine N7-21-deoxyribonucleosides is described. Solid-phase synthesis furnishes oligonucleotides containing N7-glycosylated purines. New base pairs between purine N7- and N9-nucleosides are proposed. 相似文献
975.
Ravi K. Ujjinamatada Yankanagouda S. Agasimundin Peng Zhang Ramachandra S. Hosmane Roman Schuessler Peter Borowski 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1775-1788
The attempted synthesis of a ring-expanded guanosine (1) containing the imidazo[4,5-e][1,3]diazepine ring system by condensation of 1-(2′-deoxy-β-D-erythropentofuranosyl)-4-ethoxycarbonylimidazole-5-carbaldehyde (2) with guanidine resulted in the formation of an unexpected product, 1-(2′-deoxy-β-D-erythropentofuranosyl)-5-(2,4-diamino-3,6-dihydro-1,3,5-triazin-6-yl)imidazole-4-carboxamide (7). The structure as well as the pathway of formation of 7 was corroborated by isolation of the intermediate, followed by its conversion to the product. Nucleoside 7 showed promising in vitro anti-helicase activity against the West Nile virus NTPase/ helicase with an IC 50 of 3-10 μg/mL. 相似文献
976.
Shannon K. Flood-Nichols Deborah Tinnemore Mark A. Wingerd Ali I. Abu-Alya Peter G. Napolitano Jonathan D. Stallings Danielle L. Ippolito 《Molecular & cellular proteomics : MCP》2013,12(1):55-64
Minimally invasive diagnostic tests are needed in obstetrics to identify women at risk for complications during delivery. The apolipoproteins fluctuate in complexity and abundance in maternal plasma during pregnancy and could be incorporated into a blood test to evaluate this risk. The objective of this study was to examine the relative plasma concentrations of apolipoproteins and their biochemically modified subtypes (i.e. proteolytically processed, sialylated, cysteinylated, dimerized) over gestational time using a targeted mass spectrometry approach. Relative abundance of modified and unmodified apolipoproteins A-I, A-II, C-I, C-II, and C-III was determined by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry in plasma prospectively collected from 11 gravidas with uncomplicated pregnancies at 4–5 gestational time points per patient. Apolipoproteins were readily identifiable by spectral pattern. Apo C-III2 and Apo C-III1 (doubly and singly sialylated Apo C-III subtypes) increased with gestational age (r2>0.8). Unmodified Apo A-II, Apo C-I, and Apo C-III0 showed no correlation (r2 = 0.01–0.1). Pro-Apo C-II did not increase significantly until third trimester (140 ± 13% of first trimester), but proteolytically cleaved, mature Apo C-II increased in late pregnancy (702 ± 130% of first trimester). Mature Apo C-II represented 6.7 ± 0.9% of total Apo C-II in early gestation and increased to 33 ± 4.5% in third trimester. A label-free, semiquantitative targeted proteomics approach was developed using LTQ-Orbitrap mass spectrometry to confirm the relative quantitative differences observed by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry in Apo C-III and Apo C-II isoforms between first and third trimesters. Targeted apolipoprotein screening was applied to a cohort of term and preterm patients. Modified Apo A-II isoforms were significantly elevated in plasma from mothers who delivered prematurely relative to term controls (p = 0.02). These results support a role for targeted proteomics profiling approaches in monitoring healthy pregnancies and assessing risk of adverse obstetric outcomes.The maternal physiology during pregnancy is characterized by inflammation and hyperlipidemia. Plasma protein composition fluctuates dynamically throughout gestation to reflect these physiological changes. Apolipoproteins, a diverse subset of triglyceride transport proteins, contribute to the hyperlipidemia of pregnancy by modulating lipid homeostasis in maternal plasma (1–3). Exaggerated hyperlipidemia and peripheral apolipoprotein burden are associated with inflammatory insult and signal obstetric complications (4–5). Numerous post-translationally modified apolipoprotein isoforms are reported in plasma, but it is unclear how these modifications affect apolipoprotein function and plasma distribution. For example, changes in the glycosylation status of apolipoprotein variants predate the onset of clinical symptoms in patients with preeclampsia, a hypertensive disorder of pregnancy with clinical features in common with cardiovascular disease (6–8). The identification and functional characterization of plasma apolipoprotein isoforms and their post-translationally modified subtypes may reveal important diagnostic and/or therapeutic targets for hypertensive disorders of pregnancy (6).Mass spectrometry and targeted proteomics analyses afford unprecedented sensitivity and specificity for detecting apolipoproteins and their numerous isoforms and subtypes (9–12). Mass spectrometry approaches overcome limitations inherent in biochemical approaches (e.g. ELISA [enzyme-linked immunosorbant assays] and Western blot analysis), especially the lack of specificity of antibodies for post-translationally modified variants of plasma proteins. The objective of this study was to longitudinally evaluate maternal plasma apolipoprotein profile over gestational time by SELDI-TOF-MS (surface-enhanced laser desorption/ionization-time of flight-mass spectrometry)1 analysis of intact proteins and a complementary targeted LTQ-Orbitrap XL MS approach. We evaluate changes in 13 post-translationally modified subtypes of the plasma apolipoproteins A-II, C-I, C-II, and C-III over gestational time. 相似文献
977.
Jessica Cruz de Leon Nicole Scheumann Wandy Beatty Josh R. Beck Johnson Q. Tran Candace Yau Peter J. Bradley Keith Gull Bill Wickstead Naomi S. Morrissette 《Eukaryotic cell》2013,12(7):1009-1019
SAS-6 is required for centriole biogenesis in diverse eukaryotes. Here, we describe a novel family of SAS-6-like (SAS6L) proteins that share an N-terminal domain with SAS-6 but lack coiled-coil tails. SAS6L proteins are found in a subset of eukaryotes that contain SAS-6, including diverse protozoa and green algae. In the apicomplexan parasite Toxoplasma gondii, SAS-6 localizes to the centriole but SAS6L is found above the conoid, an enigmatic tubulin-containing structure found at the apex of a subset of alveolate organisms. Loss of SAS6L causes reduced fitness in Toxoplasma. The Trypanosoma brucei homolog of SAS6L localizes to the basal-plate region, the site in the axoneme where the central-pair microtubules are nucleated. When endogenous SAS6L is overexpressed in Toxoplasma tachyzoites or Trypanosoma trypomastigotes, it forms prominent filaments that extend through the cell cytoplasm, indicating that it retains a capacity to form higher-order structures despite lacking a coiled-coil domain. We conclude that although SAS6L proteins share a conserved domain with SAS-6, they are a functionally distinct family that predates the last common ancestor of eukaryotes. Moreover, the distinct localization of the SAS6L protein in Trypanosoma and Toxoplasma adds weight to the hypothesis that the conoid complex evolved from flagellar components. 相似文献
978.
The genus Lasinus Sharp, 1874 of the Pselaphodes complex of genera (Pselaphitae: Tyrini: Tyrina) is revised. The three so far known species, Lasinus mandarinus Raffray, 1890, Lasinus monticola Sawada, 1961 and Lasinus spinosus Sharp, 1874 are redescribed. Eight new species, Lasinus sinicus
sp. n. from China, Lasinus mikado
sp. n., Lasinus yamamotoi
sp. n., Lasinus inexpectatus
sp. n., Lasinus yakushimanus
sp. n., Lasinus amamianus
sp. n., Lasinus saoriae
sp. n., and Lasinus okinawanus
sp. n. from Japan, are described. And all species are illustrated. Lectotypes are designated for Lasinus mandarinus and Lasinus spinosus. An identification key to species of the genus Lasinus is provided. 相似文献
979.
Brendan P. Kelaher Melanie J. Bishop Jaimie Potts Peter Scanes Greg Skilbeck 《Global Change Biology》2013,19(6):1909-1918
Global losses of seagrasses and mangroves, eutrophication‐driven increases in ephemeral algae, and macrophyte invasions have impacted estuarine detrital resources. To understand the implications of these changes on benthic ecosystem processes, we tested the hypotheses that detrital source richness, mix identity, and biomass influence benthic primary production, metabolism, and nutrient fluxes. On an estuarine muddy sandflat, we manipulated the availability of eight detrital sources, including mangrove, seagrass, and invasive and native algal species that have undergone substantial changes in distribution. Mixes of these detrital sources were randomly assigned to one of 12 treatments and dried detrital material was added to seventy‐two 0.25 m2 plots (n = 6 plots). The treatments included combinations of either two or four detrital sources and high (60 g) or low (40 g) levels of enrichments. After 2 months, the dark, light, and net uptake of NH4+, dissolved inorganic nitrogen, and the dark efflux of dissolved organic nitrogen were each significantly influenced by the identity of detrital mixes, rather than detrital source richness or biomass. However, gross and net primary productivity, average oxygen flux, and net NOX and dissolved inorganic phosphorous fluxes were significantly greater in treatments with low than with high detrital source richness. These results demonstrate that changes in detrital source richness and mix identity may be important drivers of estuarine ecosystem performance. Continued impacts to estuarine macrophytes may, therefore, further alter detritus‐fueled productivity and processes in estuaries. Specific tests that address predicted future changes to detrital resources are required to determine the consequences of this significant environmental problem. 相似文献
980.
Jie Ni Paul Cozzi Jingli Hao Julia Beretov Lei Chang Wei Duan Sarah Shigdar Warick Delprado Peter Graham Joseph Bucci John Kearsley Yong Li 《The international journal of biochemistry & cell biology》2013,45(12):2736-2748
Prostate cancer (CaP) is the second leading malignancy in men. The role of epithelial cell adhesion molecule (EpCAM), also known as CD326, in CaP progression and therapeutic resistance is still uncertain. Here, we aimed to investigate the roles of EpCAM in CaP metastasis and chemo/radioresistance. Expression of EpCAM in CaP cell lines and human CaP tissues was assessed using immunofluorescence and immunohistochemistry, respectively. EpCAM was knocked down (KD) in PC-3, DU145 and LNCaP-C4-2B cells using small interfering RNA (siRNA), and KD results were confirmed by confocal microscope, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Cell growth was evaluated by proliferation and colony formation assays. The invasive potential was assessed using a matrigel chamber assay. Tumorigenesis potential was measured by a sphere formation assay. Chemo-/radiosensitivity were measured using a colony formation assay. Over-expression of EpCAM was found in primary CaP tissues and lymph node metastases including cancer cells and surrounding stromal cells. KD of EpCAM suppressed CaP proliferation and invasive ability, reduced sphere formation, enhanced chemo-/radiosensitivity, and down-regulated E-cadherin, p-Akt, p-mTOR, p-4EBP1 and p-S6K expression in CaP cells. Our findings suggest that EpCAM plays an important role in CaP proliferation, invasion, metastasis and chemo-/radioresistance associated with the activation of the PI3K/Akt/mTOR signaling pathway and is a novel therapeutic target to sensitize CaP cells to chemo-/radiotherapy. 相似文献