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31.
Cell cycle progression is tightly regulated by cyclins, cyclin-dependent kinases (cdks) and related inhibitory phophatases. Here, we employed mitotic selection to synchronize the C6 glioma cell cycle at the start of the G1 phase and mapped the temporal regulation of selected cyclins, cdks and inhibitory proteins throughout the 12 h of G1 by immunoblot analysis. The D-type cyclins, D3 and D1, were differentially expressed during the C6 glioma G1 phase. Cyclin D1 was up-regulated in the mid-G1 phase (4-6 h) while cyclin D3 expression emerged only in late G1 (9-12 h). The influence of the anticonvulsant agent valproic acid (VPA) on expression of cyclins and related proteins was determined, since its teratogenic potency has been linked to cell cycle arrest in the mid-G1 phase. Exposure of C6 glioma to VPA induced a marked up-regulation of cyclin D3 and decreased expression of the proliferating cell nuclear antigen. In synchronized cell populations, increased expression of cyclin D3 by VPA was detected in the mid-G1 phase (3-5 h). Immunocytochemical localization demonstrated rapid intracellular translocation of cyclin D3 to the nucleus following VPA exposure, suggesting that VPA-induced cell cycle arrest may be mediated by precocious activation of cyclin D3 in the G1 phase. 相似文献
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Parasites of two small fish species from a Ramsar wetland in South Africa were studied in 2014–2015. The cichlid Pseudocrenilabrus philander (Weber, 1897) was parasitised by the copepod Lernaea cyprinacea Linnaeus, 1758, the monogenean Gyrodactylus thlapi Christison, Shinn & van As, 2005 and four gryporhynchid metacestode (Cyclophyllidea) species: Paradilepis scolecina (Rudolph, 1819), Paradilepis maleki Khalil, 1961, Neogryporhynchus lasiopeius Baer & Bona, 1960 and Valipora campylancristrota (Wedl, 1855). The cyprinid Enteromius paludinosus (syn. Barbus paludinosus) (Peters, 1852) was infected with the monogenean parasites Dogielius intorquens Crafford, Luus-Powell & Avenant-Oldewage, 2012, Dactylogyrus teresae Mashego, 1983, and three Dactylogyrus spp. These results represent several new locality as well as host records and further contribute information on the parasitic diversity in the Barberspan Ramsar wetland. 相似文献
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Differential Regional Effects of Methamphetamine on the Activities of
Tryptophan and Tyrosine Hydroxylase 总被引:1,自引:0,他引:1
Heather M. Haughey Annette E. Fleckenstein & Glen R. Hanson 《Journal of neurochemistry》1999,72(2):661-668
Abstract : Administration of high doses of methamphetamine (METH) produces both short- and long-term enzymatic deficits in central monoaminergic systems. To determine whether a correlative relationship exists between these acute and long-term consequences of METH treatment, in the present study we examined the regional effects of METH on tryptophan hydroxylase (TPH) and tyrosine hydroxylase (TH) activities in various regions of the caudate nucleus, nucleus accumbens, and globus pallidus. A single METH administration decreased TPH activity 1 h after treatment in the globus pallidus, in the nucleus accumbens, and throughout the caudate ; in the anterior caudate, the ventral-medial was more affected than the dorsal-lateral region. In contrast, TH activity was not decreased in either the caudate or the globus pallidus after a single METH administration ; however, it was altered in the nucleus accumbens. Seven days after multiple METH administrations, TH and TPH activities were decreased in most caudate regions but not in the nucleus accumbens or globus pallidus. These data demonstrate that (1) the effects of METH on TPH and TH vary regionally ; and (2) the short-term and long-term regional responses of TPH to METH in the caudate and globus pallidus correlated. In contrast, METH-induced acute TH responses did not predict the long-term changes in TH activity. 相似文献
34.
Factors affecting longitudinal trajectories of plasma sphingomyelins: the Baltimore Longitudinal Study of Aging 下载免费PDF全文
Michelle M. Mielke Veera Venkata Ratnam Bandaru Dingfen Han Yang An Susan M. Resnick Luigi Ferrucci Norman J. Haughey 《Aging cell》2015,14(1):112-121
Sphingomyelin metabolism has been linked to several diseases and to longevity. However, few epidemiological studies have quantified individual plasma sphingomyelin species (identified by acyl‐chain length and saturation) or their relationship between demographic factors and disease processes. In this study, we determined plasma concentrations of distinct sphingomyelin species in 992 individuals, aged 55 and older, enrolled in the Baltimore Longitudinal Study of Aging. Participants were followed, with serial measures, up to 6 visits and 38 years (3972 total samples). Quantitative analyses were performed on a high‐performance liquid chromatography‐coupled electrospray ionization tandem mass spectrometer. Linear mixed models were used to assess variation in specific sphingomyelin species and associations with demographics, diseases, medications or lifestyle factors, and plasma cholesterol and triglyceride levels. We found that most sphingomyelin species increased with age. Women had higher plasma levels of all sphingomyelin species and showed steeper trajectories of age‐related increases compared to men. African Americans also showed higher circulating sphingomyelin concentrations compared to Caucasians. Diabetes, smoking, and plasma triglycerides were associated with lower levels of many sphingomyelins and dihydrosphingomyelins. Notably, these associations showed specificity to sphingomyelin acyl‐chain length and saturation. These results demonstrate that longitudinal changes in circulating sphingomyelin levels are influenced by age, sex, race, lifestyle factors, and diseases. It will be important to further establish the intra‐individual age‐ and sex‐specific changes in each sphingomyelin species in relation to disease onset and progression. 相似文献
35.
Wang Y Mackes J Chan S Haughey NJ Guo Z Ouyang X Furukawa K Ingram DK Mattson MP 《Journal of neurochemistry》2006,99(5):1425-1434
The hippocampus is a brain region critical for learning and memory processes believed to result from long-lasting changes in the function and structure of synapses. Recent findings suggest that ATP functions as a neurotransmitter or neuromodulator in the mammalian brain, where it activates several different types of ionotropic and G protein-coupled ATP receptors that transduce calcium signals. However, the roles of specific ATP receptors in synaptic plasticity have not been established. Here we show that mice lacking the P2X3 ATP receptor (P2X3KO mice) exhibit abnormalities in hippocampal synaptic plasticity that can be restored by pharmacological modification of calcium-sensitive kinase and phosphatase activities. Calcium imaging studies revealed an attenuated calcium response to ATP in hippocampal neurons from P2X3KO mice. Basal synaptic transmission, paired-pulse facilitation and long-term potentiation are normal at synapses in hippocampal slices from P2X3KO. However, long-term depression is severely impaired at CA1, CA3 and dentate gyrus synapses. Long-term depression can be partially rescued in slices treated with a protein phosphatase 1-2 A activator or by postsynaptic inhibition of calcium/calmodulin-dependent protein kinase II. Despite the deficit in hippocampal long-term depression, P2X3KO mice performed normally in water maze tests of spatial learning, suggesting that long-term depression is not critical for this type of hippocampus-dependent learning and memory. 相似文献
36.
Yujin Sun Jonathan H. Ambrose Brena S. Haughey Tyler D. Webster Sarah N. Pierrie Daniela F. Mu?oz Emily C. Wellman Shalom Cherian Scott M. Lewis Luke E. Berchowitz Gregory P. Copenhaver 《PLoS genetics》2012,8(10)
Gene conversion, the non-reciprocal exchange of genetic information, is one of the potential products of meiotic recombination. It can shape genome structure by acting on repetitive DNA elements, influence allele frequencies at the population level, and is known to be implicated in human disease. But gene conversion is hard to detect directly except in organisms, like fungi, that group their gametes following meiosis. We have developed a novel visual assay that enables us to detect gene conversion events directly in the gametes of the flowering plant Arabidopsis thaliana. Using this assay we measured gene conversion events across the genome of more than one million meioses and determined that the genome-wide average frequency is 3.5×10−4 conversions per locus per meiosis. We also detected significant locus-to-locus variation in conversion frequency but no intra-locus variation. Significantly, we found one locus on the short arm of chromosome 4 that experienced 3-fold to 6-fold more gene conversions than the other loci tested. Finally, we demonstrated that we could modulate conversion frequency by varying experimental conditions. 相似文献
37.
K.D. Feller S. Lagerholm R. Clubwala M.T. Silver D. Haughey J.M. Ryan E.R. Loew M.E. Deutschlander K.L. Kenyon 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2009,154(4):412-418
We report the expression of three visual opsins in the retina of the little brown bat (Myotis lucifugus, Vespertilionidae). Gene sequences for a rod-specific opsin and two cone-specific opsins were cloned from cDNA derived from bat eyes. Comparative sequence analyses indicate that the two cone opsins correspond to an ultraviolet short-wavelength opsin (SWS1) and a long-wavelength opsin (LWS). Immunocytochemistry using antisera to visual opsins revealed that the little brown bat retina contains two types of cone photoreceptors within a rod-dominated background. However, unlike other mammalian photoreceptors, M. lucifugus cones and rods are morphologically indistinguishable by light microscopy. Both photoreceptor types have a thin, elongated outer segment. Using microspectrophotometry we classified the absorption spectrum for the ubiquitous rods. Similar to other mammals, bat rhodopsin has an absorption peak near 500 nm. Although we were unable to confirm a spectral range, cellular and molecular analyses indicate that M. lucifugus expresses two types of cone visual pigments located within the photoreceptor layer. This study provides important insights into the visual capacity of a nocturnal microchiropteran species. 相似文献
38.
Darren M. Griffith Aisleen Haughey Helge Müller-Bunz 《Inorganica chimica acta》2010,363(10):2333-2337
Reaction of benzisothiazolinone (Bit), a well-known biocide, with the Pd(II) and Pt(II) am(m)ine precursors cis-[Pd(en)(H2O)2](NO3)2 and cis-[Pt(NH3)2(H2O)2](NO3)2 yielded cis-Pd(en)(Bit−1H)2 and cis-Pt(NH3)2(Bit−1H)2, respectively. Bit is bound to the metal centres in both cases through the deprotonated isothiazolinone N. The crystal structures of a Bit/BitO co-crystal and cis-Pd(en)(Bit−1H)2·H2O are also described. 相似文献
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Connor Black Olivier P. Chevallier Simon A. Haughey Julia Balog Sara Stead Steven D. Pringle Maria V. Riina Francesca Martucci Pier L. Acutis Mike Morris Dimitrios S. Nikolopoulos Zoltan Takats Christopher T. Elliott 《Metabolomics : Official journal of the Metabolomic Society》2017,13(12):153