排序方式: 共有255条查询结果,搜索用时 31 毫秒
61.
Brian M. Nolen Randall E. Brand Denise Prosser Liudmila Velikokhatnaya Peter J. Allen Herbert J. Zeh William E. Grizzle Aleksey Lomakin Anna E. Lokshin 《PloS one》2014,9(4)
BackgroundThe clinical management of pancreatic cancer is severely hampered by the absence of effective screening tools.MethodsSixty-seven biomarkers were evaluated in prediagnostic sera obtained from cases of pancreatic cancer enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO).ResultsThe panel of CA 19-9, OPN, and OPG, identified in a prior retrospective study, was not effective. CA 19-9, CEA, NSE, bHCG, CEACAM1 and PRL were significantly altered in sera obtained from cases greater than 1 year prior to diagnosis. Levels of CA 19-9, CA 125, CEA, PRL, and IL-8 were negatively associated with time to diagnosis. A training/validation study using alternate halves of the PLCO set failed to identify a biomarker panel with significantly improved performance over CA 19-9 alone. When the entire PLCO set was used for training at a specificity (SP) of 95%, a panel of CA 19-9, CEA, and Cyfra 21-1 provided significantly elevated sensitivity (SN) levels of 32.4% and 29.7% in samples collected <1 and >1 year prior to diagnosis, respectively, compared to SN levels of 25.7% and 17.2% for CA 19-9 alone.ConclusionsMost biomarkers identified in previously conducted case/control studies are ineffective in prediagnostic samples, however several biomarkers were identified as significantly altered up to 35 months prior to diagnosis. Two newly derived biomarker combinations offered advantage over CA 19-9 alone in terms of SN, particularly in samples collected >1 year prior to diagnosis. However, the efficacy of biomarker-based tools remains limited at present. Several biomarkers demonstrated significant velocity related to time to diagnosis, an observation which may offer considerable potential for enhancements in early detection. 相似文献
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Aleksey V Zimin Alaina Shumate Ida Shinder Jakob Heinz Daniela Puiu Mihaela Pertea Steven L Salzberg 《Genetics》2022,220(2)
Until 2019, the human genome was available in only one fully annotated version, GRCh38, which was the result of 18 years of continuous improvement and revision. Despite dramatic improvements in sequencing technology, no other genome was available as an annotated reference until 2019, when the genome of an Ashkenazi individual, Ash1, was released. In this study, we describe the assembly and annotation of a second individual genome, from a Puerto Rican individual whose DNA was collected as part of the Human Pangenome project. The new genome, called PR1, is the first true reference genome created from an individual of African descent. Due to recent improvements in both sequencing and assembly technology, and particularly to the use of the recently completed CHM13 human genome as a guide to assembly, PR1 is more complete and more contiguous than either GRCh38 or Ash1. Annotation revealed 37,755 genes (of which 19,999 are protein coding), including 12 additional gene copies that are present in PR1 and missing from CHM13. Fifty-seven genes have fewer copies in PR1 than in CHM13, 9 map only partially, and 3 genes (all noncoding) from CHM13 are entirely missing from PR1. 相似文献
63.
The work describes features of the compressed sensing (CS) approach utilized for development of a wearable system for wrist vein recognition with single‐pixel detection; we consider this system useful for biometrics authentication purposes. The CS approach implies use of a spatial light modulation (SLM) which, in our case, can be performed differently—with a liquid crystal display or diffusely scattering medium. We show that compressed sensing combined with above‐mentioned means of SLM allows us to avoid using an optical system—a limiting factor for wearable devices. The trade‐off between the 2 different SLM approaches regarding issues of practical implementation of CS approach for wrist vein recognition purposes is discussed. A possible solution of a misalignment problem—a typical issue for imaging systems based upon 2D arrays of photodiodes—is also proposed. Proposed design of the wearable device for wrist vein recognition is based upon single‐pixel detection. 相似文献
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Yaroslav G. Gurskiy David G. Garbuz Nataliya V. Soshnikova Aleksey N. Krasnov Alexei Deikin Vladimir F. Lazarev Dmitry Sverchinskyi Boris A. Margulis Olga G. Zatsepina Vadim L. Karpov Svetlana N. Belzhelarskaya Evgenia Feoktistova Sofia G. Georgieva Michael B. Evgen’ev 《Cell stress & chaperones》2016,21(6):1055-1064
The production of major human heat shock protein Hsp70 (HSPA1A) in a eukaryotic expression system is needed for testing and possible medical applications. In this study, transgenic mice were produced containing wild-type human Hsp70 allele in the vector providing expression in the milk. The results indicated that human Hsp70 was readily expressed in the transgenic animals but did not apparently preserve its intact structure and, hence, it was not possible to purify the protein using conventional isolation techniques. It was suggested that the protein underwent glycosylation in the process of expression, and this quite common modification for proteins expressed in the milk complicated its isolation. To check this possibility, we mutated all presumptive sites of glycosylation and tested the properties of the resulting modified Hsp70 expressed in E. coli. The investigation demonstrated that the modified protein exhibited all beneficial properties of the wild-type Hsp70 and was even superior to the latter for a few parameters. Based on these results, a transgenic mouse strain was obtained which expressed the modified Hsp70 in milk and which was easy to isolate using ATP columns. Therefore, the developed construct can be explored in various bioreactors for reliable manufacture of high quality, uniform, and reproducible human Hsp70 for possible medical applications including neurodegenerative diseases and cancer. 相似文献
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Choi SH Quinti L Kazantsev AG Silverman RB 《Bioorganic & medicinal chemistry letters》2012,22(8):2789-2793
Inhibition of sirtuin 2 (SIRT2) is known to be protective against the toxicity of disease proteins in Parkinson's and Huntington's models of neurodegeneration. Previously, we developed SIRT2 inhibitors based on the 3-(N-arylsulfamoyl)benzamide scaffold, including3-(N-(4-bromophenyl)sulfamoyl)-N-(4-bromophenyl)benzamide(C2-8, 1a), which demonstrated neuroprotective effects in a Huntington's mouse model, but had low potency of SIRT2 inhibition. Here we report that N-methylation of 1a greatly increases its potency and results in excellent selectivity for SIRT2 over SIRT1 and SIRT3 isoforms. Structure-activity relationships observed for 1a analogs and docking simulation data suggest that the para-substituted amido moiety of these compounds could occupy two potential hydrophobic binding pockets in SIRT2. These results provide a direction for the design of potent drug-like SIRT2 inhibitors. 相似文献
68.
Remus TP Zima AV Bossuyt J Bare DJ Martin JL Blatter LA Bers DM Mignery GA 《The Journal of biological chemistry》2006,281(1):608-616
Phosphoinositides participate in many signaling cascades via phospholipase C stimulation, which hydrolyzes phosphatidylinositol 4,5-bisphosphate, producing second messengers diacylglycerol and inositol 1,4,5-trisphosphate (InsP3). Destructive chemical approaches required to measure [InsP3] limit spatiotemporal understanding of subcellular InsP3 signaling. We constructed novel fluorescence resonance energy transfer-based InsP3 biosensors called FIRE (fluorescent InsP3-responsive element) by fusing plasmids encoding the InsP3-binding domain of InsP3 receptors (types 1-3) between cyan fluorescent protein and yellow fluorescent protein sequences. FIRE was expressed and characterized in COS-1 cells, cultured neonatal cardiac myocytes, and incorporated into an adenoviral vector for expression in adult cardiac ventricular myocytes. FIRE-1 exhibits an approximately 11% increase in the fluorescence ratio (F530/F480) at saturating [InsP3] (apparent K(d) = 31.3 +/- 6.7 nm InsP3). In COS-1 cells, neonatal rat cardiac myocytes and adult cat ventricular myocytes FIRE-1 exhibited comparable dynamic range and a 10% increase in donor (cyan fluorescent protein) fluorescence upon bleach of yellow fluorescent protein, indicative of fluorescence resonance energy transfer. In FIRE-1 expressing ventricular myocytes endothelin-1, phenylephrine, and angiotensin II all produced rapid and spatially resolved increases in [InsP3] using confocal microscopy (with free [InsP3] rising to approximately 30 nm). Local entry of intracellular InsP3 via membrane rupture by a patch pipette (containing InsP3)in myocytes expressing FIRE-1 allowed detailed spatiotemporal monitoring of intracellular InsP3 diffusion. Both endothelin-1-induced and direct InsP3 application (via pipette rupture) revealed that InsP3 diffusion into the nucleus occurs with a delay and blunted rise of [InsP3] versus cytosolic [InsP3]. These new biosensors allow studying InsP3 dynamics at high temporal and spatial resolution that will be powerful in under-standing InsP3 signaling in intact cells. 相似文献
69.
Maxim A. Timofeyev Zhanna M. Shatilina Marina V. Protopopova Darya S. Bedulina Vasiliy V. Pavlichenko Aleksey V. Kolesnichenko C.E.W. Steinberg 《Journal of thermal biology》2009,34(6):281-285
This study comparatively evaluated small heat shock proteins (sHSP) (related to α-crystallin) and antioxidant enzymes such as peroxidase (POD), catalase (CAT), glutathione S-transferase (GST) as anti-thermal stress response in two contrasting freshwater amphipods, the stenoecious Baikalean endemic Eulimnogammarus cyaneus and the Palearctic Gammarus lacustris.The thermal stress modulated the activity of antioxidant enzymes as well as the sHSP synthesis in both species. In both species, only the declining POD activity showed a clear dependency on exposure time.The most expressed response to elevated temperatures has been the activation of sHSP synthesis, with clear differences in the patterns: in G. lacustris, sHSP concentrations peaked after 12 h with a subsequent decline, while they increased steadily in E. cyaneus. Hence, the stenoecious species did not acclimate to the thermal stress within the given exposure time as the euryecious did. 相似文献
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Sergey S. Alekseyev Mikhail V. Mina Ella M. Smirina Aleksey A. Sokolov 《Environmental Biology of Fishes》2009,86(4):487-505
In some polymorphic populations of Arctic charr in Transbaikalia, an individual can transform from a smaller to larger size
form during their lifetime as a result of accelerated growth that follows a period of slow growth and reproduction as a small
size form. Alternating periods of slow and fast growth are reflected in growth layer patterns visible in fin ray cross sections.
Stained microtome fin ray cross sections were used to reveal the incidence of transformations from one form to another. Data
were collected from 14 northern Transbaikalian lakes containing two or three sympatric Arctic charr forms (‘dwarf’, ‘small’,
and ‘large’) exhibiting varying levels of morphological separation. Individuals recruited from the dwarf or small form were
found in varying proportions among the small and/or large form in 12 lakes. Small or large form charr that grew without noticeable
acceleration to the adult size typical of the form or experienced accelerated growth as juveniles prior to maturation were
also observed. There were no transformations between sympatric forms that differed in the length and number of gill rakers
and in some other meristic characters. Results indicate that in the region under study, transformations of sympatric Arctic
charr size forms are a widespread, but not a ubiquitous, phenomenon. Such transformations reflect the plasticity of the developmental
channels of the forms. In the course of intra-lacustrine form divergence and genetic differentiation, the frequency of the
observed transformations decreases to zero. 相似文献