Association of pKi-67 with satellite DNA of the human genome in early G1 cells.

PubMed

Bridger, J M; Kill, I R; Lichter, P

1998-01-01

pKi-67 is a nucleolar antigen that provides a specific marker for proliferating cells. It has been shown previously that pKi-67's distribution varies in a cell cycle-dependent manner: it coats all chromosomes during mitosis, accumulates in nuclear foci during G1 phase (type I distribution) and localizes within nucleoli in late G1 S and G2 phase (type II distribution). Although no function has as yet been ascribed to pKi-67, it has been found associated with centromeres in G1. In the present study the distribution pattern of pKi-67 during G1 in human dermal fibroblasts (HDFs) was analysed in more detail. Synchronization experiments show that in very early G1 cells pKi-67 coincides with virtually all satellite regions analysed, i.e. with centromeric (alpha-satellite), telomeric (minisatellite) and heterochromatic blocks (satellite III) on chromosomes 1 and Y (type Ia distribution). In contrast, later in the G1 phase, a smaller fraction of satellite DNA regions are found collocalized with pKi-67 foci (type Ib distribution). When all pKi-67 becomes localized within nucleoli, even fewer satellite regions remain associated with the pKi-67 staining. However, all centromeric and short arm regions of the acrocentric chromosomes, which are in very close proximity to or even contain the rRNA genes, are collocalized with anti-pKi-67 staining throughout the remaining interphase of the cell cycle. Thus, our data demonstrate that during post-mitotic reformation and nucleogenesis there is a progressive decline in the fraction of specific satellite regions of DNA that remain associated with pKi-67. This may be relevant to nucleolar reformation following mitosis.

High-level mRNA quantification of proliferation marker pKi-67 is correlated with favorable prognosis in colorectal carcinoma.

PubMed

Ihmann, Thomas; Liu, Jian; Schwabe, Wolfgang; Häusler, Peter; Behnke, Detlev; Bruch, Hans-Peter; Broll, Rainer; Windhövel, Ute; Duchrow, Michael

2004-12-01

The present study retrospectively examines the expression of pKi-67 mRNA and protein in colorectal carcinoma and their correlation to the outcome of patients. Immunohistochemistry and quantitative RT-PCR were used to analyze the expression of pKi-67 in 43 archival specimens of patients with curatively resected primary colorectal carcinoma, who were not treated with neo-adjuvant therapy. We determined a median pKi-67 (MIB-1) labeling index of 31.3% (range 10.3-66.4%), and a mean mRNA level of 0.1769 (DeltaC(T): range 0.01-0.69); indices and levels did not correlate. High pKi-67 mRNA DeltaC(T) values were associated with a significantly favorable prognosis, while pKi-67 labeling indices were not correlated to prognostic outcome. A multivariate analysis of clinical and biological factors indicated that tumor stage (UICC) and pKi-67 mRNA expression level were independent prognostic factors. Quantitatively determined pKi-67 mRNA can be a good and new prognostic indicator for primary resected colorectal carcinoma.

Evidence for small-scale heterogeneity in Earth's inner core from a global study of PKiKP coda waves

NASA Astrophysics Data System (ADS)

Koper, Keith D.; Franks, Jill M.; Dombrovskaya, Marina

2004-12-01

Recent seismic observations have provided evidence that the inner core contains strong heterogeneity at a scale-length of tens of kilometers. The corresponding lateral variations in elastic properties could be caused by pockets of partial melt, alignment of iron crystals, or variations in chemistry. However, the relevant seismic observations (precritical PKiKP coda waves) were subtle and were made using historic seismic data. Furthermore, it has been suggested that the seismic data might be explainable by scatterers in the lower mantle or by a complex inner core boundary. To address these issues, we investigate a preexisting global database of precritical PKiKP waveforms at distances of 10°-50°, and a second, newly generated global data base of PKiKP waveforms at distances of 50°-90°. We analyze the data using standard array processing techniques and identify PKiKP coda waves based on travel time, ray parameter, amplitude, and coherence. Although it remains unclear whether the scattered energy is being created within the inner core or along its boundary, we find three lines of evidence which support the idea that it is in fact related to the inner core: at smaller distances the decay rate of PKiKP coda is significantly lower than the decay rates of the corresponding PcP and ScP codas; at larger distances, we find examples of emergent, spindle-shaped PKiKP coda waves that exist without the parent PKiKP phase; and at larger distances, we infer a PKiKP coda decay rate similar to that determined from the data at the smaller distances. It is likely that many more PKiKP coda observations can be made with existing data sets, and hence seismologists possess a new, extraordinarily fine probe for inferring inner core structure.

Antitumor efficacy profile of PKI-402, a dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor.

PubMed

Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Soloveva, Veronica; Venkatesan, Aranapakam; Dehnhardt, Christoph; Delos Santos, Efren; Chen, Zecheng; Dos Santos, Osvaldo; Ayral-Kaloustian, Semiramis; Gibbons, Jay

2010-04-01

PKI-402 is a selective, reversible, ATP-competitive, equipotent inhibitor of class I phosphatidylinositol 3-kinases (PI3K), including PI3K-alpha mutants, and mammalian target of rapamycin (mTOR; IC(50) versus PI3K-alpha = 2 nmol/L). PKI-402 inhibited growth of human tumor cell lines derived from breast, brain (glioma), pancreas, and non-small cell lung cancer tissue and suppressed phosphorylation of PI3K and mTOR effector proteins (e.g., Akt at T308) at concentrations that matched those that inhibited cell growth. In MDA-MB-361 [breast: Her2(+) and PIK3CA mutant (E545K)], 30 nmol/L PKI-402 induced cleaved poly(ADP-ribose) polymerase (PARP), a marker for apoptosis. In vivo, PKI-402 inhibited tumor growth in MDA-MB-361, glioma (U87MG), and lung (A549) xenograft models. In MDA-MB-361, PKI-402 at 100 mg/kg (daily for 5 days, one round) reduced initial tumor volume of 260 mm(3) to 129 mm(3) and prevented tumor regrowth for 70 days. In MDA-MB-361 tumors, PKI-402 (100 mg/kg, single dose) suppressed Akt phosphorylation (at T308) and induced cleaved PARP. Suppression of phosphorylated Akt (p-Akt) was complete at 8 hours and still evident at 24 hours. Cleaved PARP was evident at 8 and 24 hours. In normal tissue (heart and lung), PKI-402 (100 mg/kg) had minimal effect on p-Akt, with no detectable cleaved PARP. Preferential accumulation of PKI-402 in tumor tissue was observed. Complete, sustained suppression of Akt phosphorylation may cause tumor regression in MDA-MB-361 and other xenograft models. We are testing whether dual PI3K/mTOR inhibitors can durably suppress p-Akt, induce cleaved PARP, and cause tumor regression in a diverse set of human tumor xenograft models. Mol Cancer Ther; 9(4); 976-84. (c)2010 AACR.

Protein kinase inhibitor peptide (PKI): a family of endogenous neuropeptides that modulate neuronal cAMP-dependent protein kinase function.

PubMed

Dalton, George D; Dewey, William L

2006-02-01

Signal transduction cascades involving cAMP-dependent protein kinase are highly conserved among a wide variety of organisms. Given the universal nature of this enzyme it is not surprising that cAMP-dependent protein kinase plays a critical role in numerous cellular processes. This is particularly evident in the nervous system where cAMP-dependent protein kinase is involved in neurotransmitter release, gene transcription, and synaptic plasticity. Protein kinase inhibitor peptide (PKI) is an endogenous thermostable peptide that modulates cAMP-dependent protein kinase function. PKI contains two distinct functional domains within its amino acid sequence that allow it to: (1) potently and specifically inhibit the activity of the free catalytic subunit of cAMP-dependent protein kinase and (2) export the free catalytic subunit of cAMP-dependent protein kinase from the nucleus. Three distinct PKI isoforms (PKIalpha, PKIbeta, PKIgamma) have been identified and each isoform is expressed in the brain. PKI modulates neuronal synaptic activity, while PKI also is involved in morphogenesis and symmetrical left-right axis formation. In addition, PKI also plays a role in regulating gene expression induced by cAMP-dependent protein kinase. Future studies should identify novel physiological functions for endogenous PKI both in the nervous system and throughout the body. Most interesting will be the determination whether functional differences exist between individual PKI isoforms which is an intriguing possibility since these isoforms exhibit: (1) cell-type specific tissue expression patterns, (2) different potencies for the inhibition of cAMP-dependent protein kinase activity, and (3) expression patterns that are hormonally, developmentally and cell-cycle regulated. Finally, synthetic peptide analogs of endogenous PKI will continue to be invaluable tools that are used to elucidate the role of cAMP-dependent protein kinase in a variety of cellular processes throughout the nervous

Fine Structure of the Outermost Solid Core from Analysis of PKiKP Coda Waves

NASA Astrophysics Data System (ADS)

Krasnoshchekov, D.; Kaazik, P.; Ovtchinnikov, V.

2006-05-01

Near surface heterogeneities in the Earth's inner core have recently been confirmed to exist, and pods of partial melt or variations in seismic anisotropy either due to orientation of iron crystals or changes in strength were indicated as possible sources for such peculiarities. In the same time, analysis of the phase reflected from the inner core boundary (PKiKP) predicts complex character of the reflecting discontinuity in the form of local thin transition layers resulting in mosaic structure of the Earth's inner core's surface. Precritical PKiKP waveforms and coda waves provide necessary seismological constraints to investigate fine structure of the upper part of the Earth's inner core and its boundary, and rank high among researches that detected the described specifics of the solid core. PKiKP coda studies have to do with weak amplitudes and subtle effects, which frequently requires using a reference core related seismic phase and array data processing, as well as eliminating max number of factors biasing the resulting estimates (for example, source related inaccuracies typical for earthquake analysis). In this work we report new observations of PKiKP coda waves detected on records of a group of Underground Nuclear Explosions (UNEs) carried out in USSR and recorded at distances from 6 to 95 degrees by stations of the world seismological network. Our dataset benefits from using accurate ground truth information on source parameters (locations, origin times, depths, etc.), requires no accounting for different source radiation patterns and contains records corresponding to the whole range of precritical reflection including so called transparent zone where amplitudes of direct PKiKP phase are negligible. The processed dataset incorporates records of the array of sources consisted of the same magnitude explosions closely carried out at Semipalatinsk Test Site and recorded by stations located in Eurasia, Africa and North America. We detect PKiKP coda waves on

Classification of typical and atypical antipsychotic drugs on the basis of dopamine D-1, D-2 and serotonin2 pKi values.

PubMed

Meltzer, H Y; Matsubara, S; Lee, J C

1989-10-01

The pKi values of 13 reference typical and 7 reference atypical antipsychotic drugs (APDs) for rat striatal dopamine D-1 and D-2 receptor binding sites and cortical serotonin (5-HT2) receptor binding sites were determined. The atypical antipsychotics had significantly lower pKi values for the D-2 but not 5-HT2 binding sites. There was a trend for a lower pKi value for the D-1 binding site for the atypical APD. The 5-HT2 and D-1 pKi values were correlated for the typical APD whereas the 5-HT2 and D-2 pKi values were correlated for the atypical APD. A stepwise discriminant function analysis to determine the independent contribution of each pKi value for a given binding site to the classification as a typical or atypical APD entered the D-2 pKi value first, followed by the 5-HT2 pKi value. The D-1 pKi value was not entered. A discriminant function analysis correctly classified 19 of 20 of these compounds plus 14 of 17 additional test compounds as typical or atypical APD for an overall correct classification rate of 89.2%. The major contributors to the discriminant function were the D-2 and 5-HT2 pKi values. A cluster analysis based only on the 5-HT2/D2 ratio grouped 15 of 17 atypical + one typical APD in one cluster and 19 of 20 typical + two atypical APDs in a second cluster, for an overall correct classification rate of 91.9%. When the stepwise discriminant function was repeated for all 37 compounds, only the D-2 and 5-HT2 pKi values were entered into the discriminant function.(ABSTRACT TRUNCATED AT 250 WORDS)

PKI: The DoD’s Critical Supporting Infrastructure for Information Assurance

DTIC Science & Technology

2009-12-01

Allen Hamilton,AF PKI SPO,4241 E Piedras Dr STE 210,San Antonio,TX,78228 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY...4241 E Piedras DR STE 210 San Antonio,TX 78228 Phone: (210) 925-9129 Fax: (210) 925-2644 E-mail: susan.chandler.3.ctr@ us.af.mil Jerrod Loyless is a...Professional. General Dynamics C4 Systems AF PKI SPO 4241 E Piedras DR STE 210 San Antonio,TX 78228 Phone: (210) 925-2073 Fax: (210) 925-2644 E-mail

Suppression of Zika Virus Infection and Replication in Endothelial Cells and Astrocytes by PKA Inhibitor PKI 14-22.

PubMed

Cheng, Fan; Ramos da Silva, Suzane; Huang, I-Chueh; Jung, Jae U; Gao, Shou-Jiang

2018-02-15

The recent outbreak of Zika virus (ZIKV), a reemerging flavivirus, and its associated neurological disorders, such as Guillain-Barré (GB) syndrome and microcephaly, have generated an urgent need to develop effective ZIKV vaccines and therapeutic agents. Here, we used human endothelial cells and astrocytes, both of which represent key cell types for ZIKV infection, to identify potential inhibitors of ZIKV replication. Because several pathways, including the AMP-activated protein kinase (AMPK), protein kinase A (PKA), and mitogen-activated protein kinase (MAPK) signaling pathways, have been reported to play important roles in flavivirus replication, we tested inhibitors and agonists of these pathways for their effects on ZIKV replication. We identified the PKA inhibitor PKI 14-22 (PKI) to be a potent inhibitor of ZIKV replication. PKI effectively suppressed the replication of ZIKV from both the African and Asian/American lineages with a high efficiency and minimal cytotoxicity. While ZIKV infection does not induce PKA activation, endogenous PKA activity is essential for supporting ZIKV replication. Interestingly, in addition to PKA, PKI also inhibited another unknown target(s) to block ZIKV replication. PKI inhibited ZIKV replication at the postentry stage by preferentially affecting negative-sense RNA synthesis as well as viral protein translation. Together, these results have identified a potential inhibitor of ZIKV replication which could be further explored for future therapeutic application. IMPORTANCE There is an urgent need to develop effective vaccines and therapeutic agents against Zika virus (ZIKV) infection, a reemerging flavivirus associated with neurological disorders, including Guillain-Barré (GB) syndrome and microcephaly. By screening for inhibitors of several cellular pathways, we have identified the PKA inhibitor PKI 14-22 (PKI) to be a potent inhibitor of ZIKV replication. We show that PKI effectively suppresses the replication of all ZIKV

The proliferation marker pKi-67 organizes the nucleolus during the cell cycle depending on Ran and cyclin B.

PubMed

Schmidt, Mirko H H; Broll, Rainer; Bruch, Hans-Peter; Bögler, Oliver; Duchrow, Michael

2003-01-01

The proliferation marker pKi-67 ('Ki-67 antigen') is commonly used in clinical and research pathology to detect proliferating cells, as it is only expressed during cell-cycle progression. Despite the fact that this antigen has been known for nearly two decades, there is still no adequate understanding of its function. This study has therefore identified proteins that interact with pKi-67, using a yeast two-hybrid system. A mammalian two-hybrid system and immunoprecipitation studies were used to verify these interactions. Among other cell-cycle regulatory proteins, two binding partners associated with the small GTPase Ran were identified. In addition, DNA-structural and nucleolus-associated proteins binding to pKi-67 were found. Moreover, it was demonstrated that the N-terminal domain of pKi-67 is capable of self-binding to its own repeat region encoded by exon 13. Since RanBP, a protein involved in the transport of macromolecules over the nuclear lamina, was found to be a binding partner, a possible effect of pKi-67 on the localization of cell-cycle regulatory proteins was proposed. To test this hypothesis, a tetracycline-responsive gene expression system was used to induce the pKi-67 fragments previously used for the two-hybrid screens in HeLa cells. Subsequent immunostaining revealed the translocation of cyclin B1 from cytoplasm to nucleoli in response to this expression. It is suggested that pKi-67 is a Ran-associated protein with a role in the disintegration and reformation of the nucleolus and thereby in entry into and exit from the M-phase. Copyright 2002 John Wiley & Sons, Ltd.

pKI values of prazosin and idazoxan for receptors stimulated by neuronally released transmitter in the epididymal portion of rat isolated vas deferens.

PubMed

Mackay, D; Kengatharan, M

1994-01-01

1. A new method has been used to measure pKI values of prazosin and idazoxan against neuronally-released transmitter in the epididymal portion of the rat isolated vas deferens. The most reproducible results were obtained with a prolonged antagonist equilibration time (1 h). 2. Under these conditions the pKI of prazosin was practically unaffected by addition of alpha, beta-methylene-adenosine-5'-triphosphate (10 microM) to desensitize purinoceptors. Addition of desmethylimipramine (DMI) (0.3 microM) produced a small, but statistically non-significant, reduction. 3. The same method has been used to measure the pKI of prazosin against exogenous noradrenaline. In the latter case addition of DMI (0.3 microM) and corticosterone (30 microM) together produced a statistically significant reduction in the apparent pKI of prazosin. 4. The new method for estimating pKI values shows that DMI itself acts either pseudo-irreversibly or non-competitively and may be reducing the apparent pKI of prazosin. 5. The pKI values obtained for prazosin and idazoxan against neuronally-released transmitter are in good agreement with those obtained by other workers for the actions of these drugs on alpha-adrenoceptors.

Imaging the 'mosaic' structure of ICB by pre-critical PcP-PKiKP phases

NASA Astrophysics Data System (ADS)

Shen, Z.; Ai, Y.; He, Y.; Jiang, M.

2013-12-01

Slowly growing in highly homogeneous liquid outer core, earth inner core has been thought lacking of significant heterogeneous structure. However, seismic observations of recent decades have demonstrated hierarchical heterogeneous structure as hemispherical longitudinal dichotomy superimposed by coda-generating scattering heterogeneities with diameters of tens of kilometers, indicating complicity of inner core crystallizing environment and related dynamic process. Furthermore, as boundary of phase transform and energy-material exchange, ICB has been unveiled as patchy mosaic-like surface, based on high variety of global pre-critical PcP-PKiKP amplitude ratios. From dense arrays deployed across East and South China in the year 2005~2011 and 13 earthquakes of west Pacific subduction zone, we have collected over 150 clear pre-critical PcP-PKiKP waveforms of epicenter distance range between 14~35°, providing an ideal sampling to detect possible ICB regional variation of the East Asia area. The amplitude observation exhibits good geographical coherency which is characterized as region of high density contrast (>1.0g/cm3) located beneath East China demarcated by the low (around or lower than 0.6g/cm3) on the periphery, except the southeastward stretching. This contrasting depicts vividly the claimed 'mosaic' ICB and bridges the gap between hemispherical (~1000km order) and scatter-inducing (~10km order or less) scales of heterogeneity. On the other hand, travel time residues of PcP-PKiKP in our study reveal a complex pattern north of ~18°N perturbed strongly by shallow (crust and mantle) anomalies and remarkable delay of PKiKP in the south, implicating effects of undetected ULVZ below Celebes Sea. This research is supported by the National Natural Science Foundation of China (NSFC, grant 90914011, 41125015). Distribution of PcP-PKiKP relative amplitude ratio

PKI-587 and sorafenib targeting PI3K/AKT/mTOR and Ras/Raf/MAPK pathways synergistically inhibit HCC cell proliferation.

PubMed

Gedaly, Roberto; Angulo, Paul; Hundley, Jonathan; Daily, Michael F; Chen, Changguo; Evers, B Mark

2012-08-01

Deregulated Ras/Raf/MAPK and PI3K/AKT/mTOR signaling pathways are found in hepatocellular carcinoma (HCC). This study aimed to test the inhibitory effects of PKI-587 and sorafenib as single agents or in combination on HCC (Huh7 cell line) proliferation. (3)H-thymidine incorporation and MTT assay were used to assess Huh7 cell proliferation. Phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways was detected by Western blot. We found that PKI-587 is a more potent PI3K/mTOR inhibitor than PI-103. Combination of PKI-587 and sorafenib was a more effective inhibitor of Huh7 proliferation than the combination of PI-103 and sorafenib. Combination of PKI-587 and sorafenib synergistically inhibited epidermal growth factor (EGF)-stimulated Huh7 proliferation compared with monodrug therapy. EGF increased phosphorylation of Ras/Raf downstream signaling proteins MEK and ERK; EGF-stimulated activation was inhibited by sorafenib. However, sorafenib, as a single agent, increased AKT (Ser473) phosphorylation. EGF-stimulated AKT (ser473) activation was inhibited by PKI-587. PKI-587 is a potent inhibitor of AKT (Ser473), mTOR (Ser2448), and S6K (Thr389) phosphorylation; in contrast, rapamycin stimulated mTOR complex 2 substrate AKT(Ser473) phosphorylation although it inhibited mTOR complex 1 substrate S6K phosphorylation. PKI-587, as a single agent, stimulated MEK and ERK phosphorylation. However, when PKI-587 and sorafenib were used in combination, they inhibited all the tested kinases in the Ras/Raf /MAPK and PI3K/AKT/mTOR pathways. The combination of PKI-587 and sorafenib has the advantage over monodrug therapy on inhibition of HCC cell proliferation by blocking both PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

The proliferation marker pKi-67 becomes masked to MIB-1 staining after expression of its tandem repeats.

PubMed

Schmidt, Mirko H H; Broll, Rainer; Bruch, Hans-Peter; Duchrow, Michael

2002-11-01

The Ki-67 antigen, pKi-67, is one of the most commonly used markers of proliferating cells. The protein can only be detected in dividing cells (G(1)-, S-, G(2)-, and M-phase) but not in quiescent cells (G(0)). The standard antibody to detect pKi-67 is MIB-1, which detects the so-called 'Ki-67 motif' FKELF in 9 of the protein's 16 tandem repeats. To investigate the function of these repeats we expressed three of them in an inducible gene expression system in HeLa cells. Surprisingly, addition of a nuclear localization sequence led to a complete absence of signal in the nuclei of MIB-1-stained cells. At the same time antibodies directed against different epitopes of pKi-67 did not fail to detect the protein. We conclude that the overexpression of the 'Ki-67 motif', which is present in the repeats, can lead to inability of MIB-1 to detect its antigen as demonstrated in adenocarcinoma tissue samples. Thereafter, in order to prevent the underestimation of Ki-67 proliferation indices in MIB-1-labeled preparations, additional antibodies (for example, MIB-21) should be used. Additionally, we could show in a mammalian two-hybrid assay that recombinant pKi-67 repeats are capable of self-associating with endogenous pKi-67. Speculating that the tandem repeats are intimately involved in its protein-protein interactions, this offers new insights in how access to these repeats is regulated by pKi-67 itself.

Impact of coalition interoperability on PKI

NASA Astrophysics Data System (ADS)

Krall, Edward J.

2003-07-01

This paper examines methods for providing PKI interoperability among units of a coalition of armed forces drawn from different nations. The area in question is tactical identity management, for the purposes of confidentiality, integrity and non-repudiation in such a dynamic coalition. The interoperating applications under consideration range from email and other forms of store-and-forward messaging to TLS and IPSEC-protected real-time communications. Six interoperability architectures are examined with advantages and disadvantages of each described in the paper.

Role of regulatory subunits and protein kinase inhibitor (PKI) in determining nuclear localization and activity of the catalytic subunit of protein kinase A.

PubMed

Wiley, J C; Wailes, L A; Idzerda, R L; McKnight, G S

1999-03-05

Regulation of protein kinase A by subcellular localization may be critical to target catalytic subunits to specific substrates. We employed epitope-tagged catalytic subunit to correlate subcellular localization and gene-inducing activity in the presence of regulatory subunit or protein kinase inhibitor (PKI). Transiently expressed catalytic subunit distributed throughout the cell and induced gene expression. Co-expression of regulatory subunit or PKI blocked gene induction and prevented nuclear accumulation. A mutant PKI lacking the nuclear export signal blocked gene induction but not nuclear accumulation, demonstrating that nuclear export is not essential to inhibit gene induction. When the catalytic subunit was targeted to the nucleus with a nuclear localization signal, it was not sequestered in the cytoplasm by regulatory subunit, although its activity was completely inhibited. PKI redistributed the nuclear catalytic subunit to the cytoplasm and blocked gene induction, demonstrating that the nuclear export signal of PKI can override a strong nuclear localization signal. With increasing PKI, the export process appeared to saturate, resulting in the return of catalytic subunit to the nucleus. These results demonstrate that both the regulatory subunit and PKI are able to completely inhibit the gene-inducing activity of the catalytic subunit even when the catalytic subunit is forced to concentrate in the nuclear compartment.

The pkI gene encoding pyruvate kinase I links to the luxZ gene which enhances bioluminescence of the lux operon from Photobacterium leiognathi.

PubMed

Lin, J W; Lu, H C; Chen, H Y; Weng, S F

1997-10-09

Partial 3'-end nucleotide sequence of the pkI gene (GenBank accession No. AF019143) from Photobacterium leiognathi ATCC 25521 has been determined, and the encoded pyruvate kinase I is deduced. Pyruvate kinase I is the key enzyme of glycolysis, which converts phosphoenol pyruvate to pyruvate. Alignment and comparison of pyruvate kinase Is from P. leiognathi, E. coli and Salmonella typhimurium show that they are homologous. Nucleotide sequence reveals that the pkI gene is linked to the luxZ gene that enhances bioluminescence of the lux operon from P. leiognathi. The gene order of the pkI and luxZ genes is-pk1-ter-->-R&R"-luxZ-ter"-->, whereas ter is transcriptional terminator for the pkI and related genes, and R&R" is the regulatory region and ter" is transcriptional terminator for the luxZ gene. It clearly elicits that the pkI gene and luxZ gene are divided to two operons. Functional analysis confirms that the potential hairpin loop omega T is the transcriptional terminator for the pkI and related genes. It infers that the pkI and related genes are simply linked to the luxZ gene in P. leiognathi genome.

PKI 166 induced redox signalling and apoptosis through activation of p53, MAP kinase and caspase pathway in epidermoid carcinoma.

PubMed

Das, Subhasis; Dey, Kaushik Kumar; Bharti, Rashmi; MaitiChoudhury, Sujata; Maiti, Sukumar; Mandal, Mahitosh

2012-01-01

Cellular redox changes have emerged as a pivotal and proximal event in cancer. PKI 166 is used to determine the effects of redox sensitive inhibition of EGFR, metastasis and apoptosis in epidermoid carcinoma. Cytotoxicity study of PKI 166 (IC50 1.0 microM) treated A431 cells were performed by MTT assay for 48 and 72 hrs. Morphological analysis of PKI 166 treated A431 cells for 48 hrs. revealed the cell shrinkage, loss of filopodia and lamellipodia by phase contrast and SEM images in dose dependent manner. It has cytotoxic effects through inhibiting cellular proliferation, leads to the induction of apoptosis, as increased fraction of sub-G1 phase of the cell cycle, chromatin condensation and DNA ladder. It inhibited cyclin-D1 and cyclin-E expression and induced p53, p21 expression in dose dependent manner. Consequently, an imbalance of Bax/Bcl-2 ratio triggered caspase cascade and subsequent cleavage of PARP, thereby shifting the balance in favour of apoptosis. PKI 166 treatment actively stimulated reactive oxygen species (ROS) and mitochondrial membrane depolarization. It inhibited some metastatic properties of A431 cells supressing colony formation by soft agar assay and inhibition of MMP 9 activity by gelatin zymography and western blot analysis. PKI 166 inhibited growth factor induced phosphorylation of EGFR, Akt, MAPK, JNK and colony formation in A431 cells. Thus the inhibition of proliferation was associated with redox regulation of the caspase cascade, EGFR, Akt/PI3K, MAPK/ ERK and JNK pathway. On the other hand, increased antioxidant activity leads to decreased ROS generation inhibit the anti-proliferative and apoptotic properties of PKI 166 in A431 cells. These observations indicated PKI 166 induced redox signalling dependent inhibition of cell proliferation, metastatic properties and induction of apoptotic potential in epidermoid carcinoma.

PKI-587 and sorafenib alone and in combination on inhibition of liver cancer stem cell proliferation

PubMed Central

Gedaly, Roberto; Galuppo, Roberto; Musgrave, Yolanda; Angulo, Paul; Hundley, Jonathan; Shah, Malay; Daily, Michael F.; Chen, Changguo; Cohen, Donald A.; Spear, Brett T.; Evers, B. Mark

2015-01-01

Background Deregulated Ras/Raf/mitogen-activated protein kinase and PI3 K/AKT/mTOR signaling pathways are significant in hepatocellular carcinoma proliferation (HCC). In this study we evaluated differences in the antiproliferative effect of dual PI3 K/Akt/mTOR and Ras/Raf/mitogen-activated protein kinase inhibition of non liver cancer stem cell lines (PLC and HuH7) and liver cancer stem cell (LCSC) lines (CD133, CD44, CD24, and aldehyde dehydrogenase 1-positive cells). Materials and methods Flow cytometry was performed on the resulting tumors to identify the LCSC markers CD133, CD44, CD24, and aldehyde dehydrogenase 1. Methylthiazol tetrazolium assay was used to assess cellular proliferation. Finally, a Western blot assay was used to evaluate for inhibition of specific enzymes in these two signaling pathways. Results Using flow cytometry, we found that LCSC contain 64.4% CD133 + cells, 83.2% CD44 + cells, and 96.4% CD24 + cells. PKI-587 and sorafenib caused inhibiton of LCSC and HCC cell proliferation. PLC cells were more sensitive to PKI-587 than LCSC or Huh7 (P < 0.001). Interestingly, HuH7 cells were more sensitive to sorafenib than LCSC or PLC cells. Additionally, combination therapy with PKI-587 and sorafenib caused significantly more inhibition than monotherapy in HuH7, PLC, and LCSC. Using the methylthiazol tetrazolium assay, we found that the LCSC proliferation was inhibited with sorafenib monotherapy 39% at 5 μM (P < 0.001; n = 12) and 67% by PKI-587 at 0.1 μM (P = 0.002, n = 12) compared with control. The combination of PKI-587 and sorafenib, however, synergistically inhibited LCSC proliferation by 86% (P = 0.002; n = 12). Conclusions LCSC (CD133+, CD44+, CD24+) were able to develop very aggressive tumors with low cell concentrations at 4 to 6 wk. Cells CD133+, CD44+, CD24+ demonstrated at least moderate resistance to therapy in vitro. The combination of PKI-587 and sorafenib was better than either drug alone at inhibiting of LCSC and on HCC cell

PKI-587 and sorafenib alone and in combination on inhibition of liver cancer stem cell proliferation.

PubMed

Gedaly, Roberto; Galuppo, Roberto; Musgrave, Yolanda; Angulo, Paul; Hundley, Jonathan; Shah, Malay; Daily, Michael F; Chen, Changguo; Cohen, Donald A; Spear, Brett T; Evers, B Mark

2013-11-01

Deregulated Ras/Raf/mitogen-activated protein kinase and PI3 K/AKT/mTOR signaling pathways are significant in hepatocellular carcinoma proliferation (HCC). In this study we evaluated differences in the antiproliferative effect of dual PI3 K/Akt/mTOR and Ras/Raf/mitogen-activated protein kinase inhibition of non liver cancer stem cell lines (PLC and HuH7) and liver cancer stem cell (LCSC) lines (CD133, CD44, CD24, and aldehyde dehydrogenase 1-positive cells). Flow cytometry was performed on the resulting tumors to identify the LCSC markers CD133, CD44, CD24, and aldehyde dehydrogenase 1. Methylthiazol tetrazolium assay was used to assess cellular proliferation. Finally, a Western blot assay was used to evaluate for inhibition of specific enzymes in these two signaling pathways. Using flow cytometry, we found that LCSC contain 64.4% CD133 + cells, 83.2% CD44 + cells, and 96.4% CD24 + cells. PKI-587 and sorafenib caused inhibiton of LCSC and HCC cell proliferation. PLC cells were more sensitive to PKI-587 than LCSC or Huh7 (P < 0.001). Interestingly, HuH7 cells were more sensitive to sorafenib than LCSC or PLC cells. Additionally, combination therapy with PKI-587 and sorafenib caused significantly more inhibition than monotherapy in HuH7, PLC, and LCSC. Using the methylthiazol tetrazolium assay, we found that the LCSC proliferation was inhibited with sorafenib monotherapy 39% at 5 μM (P < 0.001; n = 12) and 67% by PKI-587 at 0.1 μM (P = 0.002, n = 12) compared with control. The combination of PKI-587 and sorafenib, however, synergistically inhibited LCSC proliferation by 86% (P = 0.002; n = 12). LCSC (CD133+, CD44+, CD24+) were able to develop very aggressive tumors with low cell concentrations at 4 to 6 wk. Cells CD133+, CD44+, CD24+, which demonstrated at least moderate resistance to therapy in vitro. The combination of PKI-587 and sorafenib was better than either drug alone at inhibiting of LCSC and on HCC cell proliferation. Copyright © 2013 Elsevier Inc. All

Epidermal growth factor receptor inhibitor PKI-166 governs cardiovascular protection without beneficial effects on the kidney in hypertensive 5/6 nephrectomized rats.

PubMed

Ulu, Nadir; Mulder, Gemma M; Vavrinec, Peter; Landheer, Sjoerd W; Duman-Dalkilic, Basak; Gurdal, Hakan; Goris, Maaike; Duin, Marry; van Dokkum, Richard P E; Buikema, Hendrik; van Goor, Harry; Henning, Robert H

2013-06-01

Transactivation of epidermal growth factor receptor (EGFR) signaling by G protein-coupled receptors has been implicated in several cardiovascular (CV) conditions, including hypertension, heart failure, and cardiac and vascular hypertrophy. However, the therapeutic potential of EGFR inhibition in these conditions is currently unknown. The main objective of the present study was to investigate cardiac, vascular, and renal effects of EGFR inhibition by 4-[4-[[(1R)-1-phenylethyl]amino]-7H-pyrrolo[2,3-d]pyrimidin-6-yl]phenol (PKI-166) in the hypertensive chronic kidney disease model. Rats underwent 5/6 nephrectomy (5/6Nx) and were treated with PKI-166, lisinopril or vehicle from week 6 after disease induction until week 12. Sham animals received either PKI-166 or vehicle. Treatment with PKI-166 did not affect the development of the characteristic renal features in 5/6Nx, including proteinuria, diminished creatinine clearance, and increased glomerulosclerosis, whereas these were attenuated by lisinopril. Despite absence of effects on progressive renal damage, PKI-166 attenuated the progression of hypertension and maintained cardiac function (left ventricle end-diastolic pressure) to a similar extent as lisinopril. Also, PKI-166 attenuated the increase in phosphorylated EGFR in the heart as induced by 5/6Nx. Moreover, PKI-166 and lisinopril restored the impaired contraction of isolated thoracic aortic rings to phenylephrine and angiotensin II and impaired myogenic constriction of small mesenteric arteries in 5/6Nx rats. Blockade of the EGFR displays a CV benefit independent of limiting the progression of renal injury. Our findings extend the evidence on EGFR signaling as a target in CV disorders.

In vivo dynamics and kinetics of pKi-67: transition from a mobile to an immobile form at the onset of anaphase.

PubMed

Saiwaki, Takuya; Kotera, Ippei; Sasaki, Mitsuho; Takagi, Masatoshi; Yoneda, Yoshihiro

2005-08-01

A cell proliferation marker protein, pKi-67, distributes to the chromosome periphery during mitosis and nucleolar heterochromatin in the interphase. We report here on the structural domains of pKi-67 that are required for its correct distribution. While both the LR domain and the conserved domain were involved in localization to the nucleolar heterochromatin, both the LR domain and the Ki-67 repeat domain were required for its distribution to the mitotic chromosome periphery. Using in vivo time-lapse microscopy, GFP-pKi-67 was dynamically tracked from the mitotic chromosome periphery to reforming nucleoli via prenucleolar bodies (PNBs). The signals in PNBs then moved towards and fused into the reforming nucleoli with a thin string-like fluorescence during early G1 phase. An analysis of the in vivo kinetics of pKi-67 using photobleaching indicated that the association of pKi-67 with chromatin was progressively altered from "loose" to "tight" after the onset of anaphase. These findings indicate that pKi-67 dynamically alters the nature of the interaction with chromatin structure during the cell cycle, which is closely related to the reformation process of the interphase nucleolar chromatin.

Effective intracellular inhibition of the cAMP-dependent protein kinase by microinjection of a modified form of the specific inhibitor peptide PKi in living fibroblasts.

PubMed

Fernandez, A; Mery, J; Vandromme, M; Basset, M; Cavadore, J C; Lamb, N J

1991-08-01

In order to obtain a peptide retaining its biological activity following microinjection into living cells, we have modified a synthetic peptide [PKi(m)(6-24)], derived from the specific inhibitor protein of the cAMP-dependent protein kinase (A-kinase) in two ways: (1) substitution of the arginine at position 18 for a D-arginine; (2) blockade of the side chain on the C-terminal aspartic acid by a cyclohexyl ester group. In an in vitro assay, PKi(m) has retained a specific inhibitory activity against A-kinase as assessed against six other kinases, with similar efficiency to that of the unmodified PKi(5-24) peptide. Microinjection of PKi(m) into living fibroblasts reveals its capacity to prevent the changes in cell morphology and cytoskeleton induced by drugs which activate endogenous A-kinase, whereas the original PKi peptide failed to do so. This inhibition of A-kinase in vivo by PKi(m) lasts between 4 and 6 h after injection. In light of its effective half-life, this modified peptide opens a route for the use of biologically active peptides in vivo, an approach which has been hampered until now by the exceedingly short half-life of peptides inside living cells. By providing a direct means of inhibiting A-kinase activity for sufficiently long periods to observe effects on cellular functions in living cells, PKi(m) represents a powerful tool in studying the potential role of cAMP-dependent phosphorylation in vivo.

Cytotoxic effect of the Her-2/Her-1 inhibitor PKI-166 on renal cancer cells expressing the connexin 32 gene.

PubMed

Fujimoto, Eriko; Yano, Tomohiro; Sato, Hiromi; Hagiwara, Kiyokazu; Yamasaki, Hiroshi; Shirai, Sumiko; Fukumoto, Keiko; Hagiwara, Hiromi; Negishi, Etsuko; Ueno, Koichi

2005-02-01

We have reported that connexin (Cx) 32 acts as a tumor suppressor gene in renal cancer cells partly due to Her-2 inactivation. Here, we determined if a Her-2/Her-1 inhibitor (PKI-166) can enhance the tumor-suppressive effect of Cx32 in Caki-2 cells from human renal cell carcinoma. The expression of Cx32 in Caki-2 cells was required for PKI-166-induced cytotoxic effect at lower doses. The cyctotoxicity was dependent on the occurrence of apoptosis and partly mediated by Cx32-driven gap junction intercellular communications. These results suggest that PKI-166 further supports the tumor-suppressive effect of the Cx32 gene in renal cancer cells through the induction of apoptosis.

The dual specificity PI3K/mTOR inhibitor PKI-587 displays efficacy against T-cell acute lymphoblastic leukemia (T-ALL).

PubMed

Gazi, Mohiuddin; Moharram, Sausan A; Marhäll, Alissa; Kazi, Julhash U

2017-04-28

Although significant improvements have been made in the treatment of acute lymphoblastic leukemia (ALL), there is a substantial subset of high-risk T-cell ALL (T-ALL) patients with relatively poor prognosis. Like in other leukemia types, alterations of the PI3K/mTOR pathway are predominant in ALL which is also responsible for treatment failure and relapse. In this study, we show that relapsed T-ALL patients display an enrichment of the PI3K/mTOR pathway. Using a panel of inhibitors targeting multiple components of the PI3K/mTOR pathway, we observed that the dual-specific PI3K/mTOR inhibitor PKI-587 was the most selective inhibitor for T-ALL cells dependent on the PI3K/mTOR pathway. Furthermore, we observed that PKI-587 blocked proliferation and colony formation of T-ALL cell lines. Additionally, PKI-587 selectively abrogated PI3K/mTOR signaling without affecting MAPK signaling both in in vitro and in vivo. Inhibition of the PI3K/mTOR pathway using PKI-587 delayed tumor progression, reduced tumor load and enhanced the survival rate in immune-deficient mouse xenograft models without inducing weight loss in the inhibitor treated mice. This preclinical study shows beneficial effects of PKI-587 on T-ALL that warrants further investigation in the clinical setting. Copyright © 2017 Elsevier B.V. All rights reserved.

NES consensus redefined by structures of PKI-type and Rev-type nuclear export signals bound to CRM1.

PubMed

Güttler, Thomas; Madl, Tobias; Neumann, Piotr; Deichsel, Danilo; Corsini, Lorenzo; Monecke, Thomas; Ficner, Ralf; Sattler, Michael; Görlich, Dirk

2010-11-01

Classic nuclear export signals (NESs) confer CRM1-dependent nuclear export. Here we present crystal structures of the RanGTP-CRM1 complex alone and bound to the prototypic PKI or HIV-1 Rev NESs. These NESs differ markedly in the spacing of their key hydrophobic (Φ) residues, yet CRM1 recognizes them with the same rigid set of five Φ pockets. The different Φ spacings are compensated for by different conformations of the bound NESs: in the case of PKI, an α-helical conformation, and in the case of Rev, an extended conformation with a critical proline docking into a Φ pocket. NMR analyses of CRM1-bound and CRM1-free PKI NES suggest that CRM1 selects NES conformers that pre-exist in solution. Our data lead to a new structure-based NES consensus, and explain why NESs differ in their affinities for CRM1 and why supraphysiological NESs bind the exportin so tightly.

Authentication in Virtual Organizations: A Reputation Based PKI Interconnection Model

NASA Astrophysics Data System (ADS)

Wazan, Ahmad Samer; Laborde, Romain; Barrere, Francois; Benzekri, Abdelmalek

Authentication mechanism constitutes a central part of the virtual organization work. The PKI technology is used to provide the authentication in each organization involved in the virtual organization. Different trust models are proposed to interconnect the different PKIs in order to propagate the trust between them. While the existing trust models contain many drawbacks, we propose a new trust model based on the reputation of PKIs.

Inhibition of mTOR's Catalytic Site by PKI-587 Is a Promising Therapeutic Option for Gastroenteropancreatic Neuroendocrine Tumor Disease.

PubMed

Freitag, Helma; Christen, Friederike; Lewens, Florentine; Grass, Irina; Briest, Franziska; Iwaszkiewicz, Sara; Siegmund, Britta; Grabowski, Patricia

2017-01-01

The characteristic clinical heterogeneity and mostly slow-growing behavior of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) cause problems in finding appropriate treatments. Thus, the current therapy options are not satisfactory. PKI-587 is a highly potent, novel dual inhibitor of PI3K and mTORC1/C2. We assessed the effects of PKI-587 in different GEP-NEN tumor models, including the poorly differentiated cell line LCC-18, and compared them with those of the established mTORC1 inhibitor everolimus. We treated BON, QGP-1, KRJ-I, and LCC-18 cell lines with increasing concentrations of the inhibitor PKI-587, and compared the results with those of everolimus and DMSO. We assessed the impact of the treatments on viability (WST-1 assay), on apoptotic processes (caspase 3/7 assay, JC-1), and on cell cycle regulation (flow cytometry). We determined alterations in signaling mediators by phosphor-specific Western blot analysis and conducted multiplexed gene expression analysis (nCounter® technology). In all cell lines, PKI-587 dose-dependently inhibited proliferation, whereas everolimus was less effective. Treatment with PKI-587 led to cell cycle arrest and induction of apoptosis and successfully suppressed activity of the direct mTORC1 target 4E-BP1, a crucial factor for tumor genesis only partially inhibited by everolimus. Gene expression analyses revealed relevant changes of RAS, MAPK, STAT, and PI3K pathway genes after treatment. Treatment-dependent and cell line-characteristic effects on AKT/Rb/E2F signaling regarding cell cycle control and apoptosis are extensively discussed in this paper. PI3K/mTOR dual targeting is a promising new therapeutic approach in neuroendocrine tumor disease that should be evaluated in further clinical trials. © 2016 The Author(s) Published by S. Karger AG, Basel.

Inhibition of mTOR's Catalytic Site by PKI-587 Is a Promising Therapeutic Option for Gastroenteropancreatic Neuroendocrine Tumor Disease

PubMed Central

Freitag, Helma; Christen, Friederike; Lewens, Florentine; Grass, Irina; Briest, Franziska; Iwaszkiewicz, Sara; Siegmund, Britta; Grabowski, Patricia

2017-01-01

Background The characteristic clinical heterogeneity and mostly slow-growing behavior of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) cause problems in finding appropriate treatments. Thus, the current therapy options are not satisfactory. PKI-587 is a highly potent, novel dual inhibitor of PI3K and mTORC1/C2. Aim We assessed the effects of PKI-587 in different GEP-NEN tumor models, including the poorly differentiated cell line LCC-18, and compared them with those of the established mTORC1 inhibitor everolimus. Methods We treated BON, QGP-1, KRJ-I, and LCC-18 cell lines with increasing concentrations of the inhibitor PKI-587, and compared the results with those of everolimus and DMSO. We assessed the impact of the treatments on viability (WST-1 assay), on apoptotic processes (caspase 3/7 assay, JC-1), and on cell cycle regulation (flow cytometry). We determined alterations in signaling mediators by phosphor-specific Western blot analysis and conducted multiplexed gene expression analysis (nCounter® technology). Results In all cell lines, PKI-587 dose-dependently inhibited proliferation, whereas everolimus was less effective. Treatment with PKI-587 led to cell cycle arrest and induction of apoptosis and successfully suppressed activity of the direct mTORC1 target 4E-BP1, a crucial factor for tumor genesis only partially inhibited by everolimus. Gene expression analyses revealed relevant changes of RAS, MAPK, STAT, and PI3K pathway genes after treatment. Treatment-dependent and cell line-characteristic effects on AKT/Rb/E2F signaling regarding cell cycle control and apoptosis are extensively discussed in this paper. Conclusion PI3K/mTOR dual targeting is a promising new therapeutic approach in neuroendocrine tumor disease that should be evaluated in further clinical trials. PMID:27513674

Interoperable PKI Data Distribution in Computational Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pala, Massimiliano; Cholia, Shreyas; Rea, Scott A.

One of the most successful working examples of virtual organizations, computational grids need authentication mechanisms that inter-operate across domain boundaries. Public Key Infrastructures(PKIs) provide sufficient flexibility to allow resource managers to securely grant access to their systems in such distributed environments. However, as PKIs grow and services are added to enhance both security and usability, users and applications must struggle to discover available resources-particularly when the Certification Authority (CA) is alien to the relying party. This article presents how to overcome these limitations of the current grid authentication model by integrating the PKI Resource Query Protocol (PRQP) into the Gridmore » Security Infrastructure (GSI).« less

A PKA survival pathway inhibited by DPT-PKI, a new specific cell permeable PKA inhibitor, is induced by T. annulata in parasitized B-lymphocytes.

PubMed

Guergnon, Julien; Dessauge, Frederic; Traincard, François; Cayla, Xavier; Rebollo, Angelita; Bost, Pierre Etienne; Langsley, Gordon; Garcia, Alphonse

2006-08-01

T. annulata, an intracellular pathogenic parasite of the Aplicomplexa protozoan family infects bovine B-lymphocytes and macrophages. Parasitized cells that become transformed survive and proliferate independently of exogenous growth factors. In the present study, we used the isogenic non parasitized BL3 and parasitized TBL3 B cell lines, as a model to evaluate the contribution of two-major PI3-K- and PKA-dependent anti-apoptotic pathways in the survival of T. annulata parasitized B lymphocytes. We found that T. annulata increases PKA activity, induces over-expression of the catalytic subunit and down-regulates the pro-survival phosphorylation state of Akt/PKB. Consistent with a role of PKA activation in survival, two pharmacological inhibitors H89 and KT5720 ablate PKA-dependent survival of parasitized cells. To specifically inhibit PKA pro-survival pathways we linked the DPTsh1 peptide shuttle sequence to PKI(5-24) and we generated DPT-PKI, a cell permeable PKI. DPT-PKI specifically inhibited PKA activity in bovine cell extracts and, as expected, also inhibited the PKA-dependent survival of T. annulata parasitized TBL3 cells. Thus, parasite-dependent constitutive activation of PKA in TBL3 cells generates an anti-apoptotic pathway that can protect T. annulata-infected B cells from apoptosis. These results also indicate that DPT-PKI could be a powerful tool to inhibit PKA pathways in other cell types.

Dual PI3K/mTOR inhibitors, GSK2126458 and PKI-587, suppress tumor progression and increase radiosensitivity in nasopharyngeal carcinoma.

PubMed

Liu, Tongxin; Sun, Quanquan; Li, Qi; Yang, Hua; Zhang, Yuqin; Wang, Rong; Lin, Xiaoshan; Xiao, Dong; Yuan, Yawei; Chen, Longhua; Wang, Wei

2015-02-01

Although combined chemoradiotherapy has provided considerable improvements for nasopharyngeal carcinoma (NPC), recurrence and metastasis are still frequent. The PI3K/Akt/mTOR pathway plays a critical role in tumor formation and tumor cell survival after radiation-induced DNA damage. In the present study, we evaluated whether inhibition of PI3K/mTOR by two novel dual inhibitors, GSK2126458 and PKI-587, could suppress tumor progression and sensitize NPC cells to radiation. Four NPC cell lines (CNE-1, CNE-2, 5-8F, and 6-10B) were used to analyze the effects of GSK216458 and PKI-587 on cell proliferation, migration, invasion, clonogenic survival, amount of residual γ-H2AX foci, cell cycle, and apoptosis after radiation. A 5-8F xenograft model was used to evaluate the in vivo effects of the two compounds in combination with ionizing radiation (IR). Both GSK216458 and PKI-587 effectively inhibited cell proliferation and motility in NPC cells and suppressed phosphorylation of Akt, mTOR, S6, and 4EBP1 proteins in a concentration- and time-dependent manner. Moreover, both compounds sensitized NPC cells to IR by increasing DNA damage, enhancing G2-M cell-cycle delay, and inducing apoptosis. In vivo, the combination of IR with GSK2126458 or PKI-587 significantly inhibited tumor growth. Antitumor effect was correlated with induction of apoptosis and suppression of the phosphorylation of mTOR, Akt, and 4EBP1. These new findings suggest the usefulness of PI3K/mTOR dual inhibition for antitumor and radiosensitizing. The combination of IR with a dual PI3K/mTOR inhibitor, GSK2126458 or PKI-587, might be a promising therapeutic strategy for NPC. ©2014 American Association for Cancer Research.

Growth inhibitory effects of the dual ErbB1/ErbB2 tyrosine kinase inhibitor PKI-166 on human prostate cancer xenografts.

PubMed

Mellinghoff, Ingo K; Tran, Chris; Sawyers, Charles L

2002-09-15

Experiments with human prostate cancer cell lines have shown that forced overexpression of the ErbB2-receptor tyrosine kinase (RTK) promotes androgen-independent growth and increases androgen receptor-transcriptional activity in a ligand-independent fashion. To investigate the relationship between ErbB-RTK signaling and androgen in genetically unmanipulated human prostate cancer, we performed biochemical and biological studies with the dual ErbB1/ErbB2 RTK inhibitor PKI-166 using human prostate cancer xenograft models with isogenic sublines reflecting the transition from androgen-dependent to androgen-independent growth. In the presence of low androgen concentrations, PKI-166 showed profound growth-inhibitory effects on tumor growth, which could be partially reversed by androgen add-back. At physiological androgen concentrations, androgen withdrawal greatly enhanced the ability of PKI-166 to retard tumor growth. The level of extracellular signal-regulated kinase activation correlated with the response to PKI-166 treatment, whereas the expression levels of ErbB1 and ErbB2 did not. These results suggest that ErbB1/ErbB2 RTKs play an important role in the biology of androgen-independent prostate cancer and provide a rationale for clinical evaluation of inhibitors targeted to this pathway.

PKI-179: an orally efficacious dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor.

PubMed

Venkatesan, Aranapakam M; Chen, Zecheng; dos Santos, Osvaldo; Dehnhardt, Christoph; Santos, Efren Delos; Ayral-Kaloustian, Semiramis; Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Yu, Ker; Chaudhary, Inder; Mansour, Tarek S

2010-10-01

A series of mono-morpholino 1,3,5-triazine derivatives (8a-8q) bearing a 3-oxa-8-azabicyclo[3.2.1]octane were prepared and evaluated for PI3-kinase/mTOR activity. Replacement of one of the bis-morpholines in lead compound 1 (PKI-587) with 3-oxa-8-azabicyclo[3.2.1]octane and reduction of the molecular weight yielded 8m (PKI-179), an orally efficacious dual PI3-kinase/mTOR inhibitor. The in vitro activity, in vivo efficacy, and PK properties of 8m are discussed. Copyright © 2010. Published by Elsevier Ltd.

A PKI Approach for Deploying Modern Secure Distributed E-Learning and M-Learning Environments

ERIC Educational Resources Information Center

Kambourakis, Georgios; Kontoni, Denise-Penelope N.; Rouskas, Angelos; Gritzalis, Stefanos

2007-01-01

While public key cryptography is continuously evolving and its installed base is growing significantly, recent research works examine its potential use in e-learning or m-learning environments. Public key infrastructure (PKI) and attribute certificates (ACs) can provide the appropriate framework to effectively support authentication and…

Anomalously strong observations of PKiKP/PcP amplitude ratios on a global scale

NASA Astrophysics Data System (ADS)

Waszek, Lauren; Deuss, Arwen

2015-07-01

The inner core boundary marks the phase transition between the solid inner core and the fluid outer core. As the site of inner core solidification, the boundary provides insight into the processes generating the seismic structures of the inner core. In particular, it may hold the key to understanding the previously observed hemispherical asymmetry in inner core seismic velocity, anisotropy, and attenuation. Here we use a large PKiKP-PcP amplitude ratio and travel time residual data set to investigate velocity and density contrast properties near the inner core boundary. Although hemispherical structure at the boundary has been proposed by previous inner core studies, we find no evidence for hemispheres in the amplitude ratios or travel time residuals. In addition, we find that the amplitude ratios are much larger than can be explained by variations in density contrast at the inner core boundary or core-mantle boundary. This indicates that PKiKP is primarily observed when it is anomalously large, due to focusing along its raypath. Using data in which PKiKP is not detected above the noise level, we calculate an upper estimate for the inner core boundary (ICB) density contrast of 1.2 kg m-3. The travel time residuals display large regional variations, which differ on long and short length scales. These regions may be explained by large-scale velocity variations in the F layer just above the inner core boundary, and/or small-scale topography of varying magnitude on the ICB, which also causes the large amplitudes. Such differences could arise from localized freezing and melting of the inner core.

A structural insight into the inhibitory mechanism of an orally active PI3K/mTOR dual inhibitor, PKI-179 using computational approaches.

PubMed

Mohd Rehan

2015-11-01

The PI3K/AKT/mTOR signaling pathway has been identified as an important target for cancer therapy. Attempts are increasingly made to design the inhibitors against the key proteins of this pathway for anti-cancer therapy. The PI3K/mTOR dual inhibitors have proved more effective than the inhibitors against only single protein targets. Recently discovered PKI-179, an orally effective compound, is one such dual inhibitor targeting both PI3K and mTOR. This anti-cancer compound is efficacious both in vitro and in vivo. However, the binding mechanisms and the molecular interactions of PKI-179 with PI3K and mTOR are not yet available. The current study investigated the exact binding mode and the molecular interactions of PKI-179 with PI3Kγ and mTOR using molecular docking and (un)binding simulation analyses. The study identified PKI-179 interacting residues of both the proteins and their importance in binding was ranked by the loss in accessible surface area, number of molecular interactions of the residue, and consistent appearance of the residue in (un)binding simulation analysis. The key residues involved in binding of PKI-179 were Ala-805 in PI3Kγ and Ile-2163 in mTOR as they have lost maximum accessible surface area due to binding. In addition, the residues which played a role in binding of the drug but were away from the catalytic site were also identified using (un)binding simulation analyses. Finally, comparison of the interacting residues in the respective catalytic sites was done for the difference in the binding of the drug to the two proteins. Thus, the pairs of the residues falling at the similar location with respect to the docked drug were identified. The striking similarity in the interacting residues of the catalytic site explains the concomitant inhibition of both proteins by a number of inhibitors. In conclusion, the docking and (un)binding simulation analyses of dual inhibitor PKI-179 with PI3K and mTOR will provide a suitable multi-target model for

Alterations in brain Protein Kinase A activity and reversal of morphine tolerance by two fragments of native Protein Kinase A inhibitor peptide (PKI).

PubMed

Dalton, George D; Smith, Forrest L; Smith, Paul A; Dewey, William L

2005-04-01

Two peptide fragments of native Protein Kinase A inhibitor (PKI), PKI-(6-22)-amide and PKI-(Myr-14-22)-amide, significantly reversed low-level morphine antinociceptive tolerance in mice. The inhibition of Protein Kinase A (PKA) activity by both peptide fragments was then measured in specific brain regions (thalamus, periaqueductal gray (PAG), and medulla) and in lumbar spinal cord (LSC), which in previous studies have been shown to play a role in morphine-induced analgesia. In drug naive animals, cytosolic PKA activity was greater than particulate PKA activity in each region, while cytosolic and particulate PKA activities were greater in thalamus and PAG compared to medulla and LSC. The addition of both peptides to homogenates from each region completely abolished cytosolic and particulate PKA activities in vitro. Following injection into the lateral ventricle of the brain of drug naive mice and morphine-tolerant mice, both peptides inhibited PKA activity in the cytosolic, but not the particulate fraction of LSC. In addition, cytosolic and particulate PKA activities were inhibited by both peptides in thalamus. These results demonstrate that the inhibition of PKA reverses morphine tolerance. Moreover, the inhibition of PKA activity in specific brain regions and LSC from morphine-tolerant mice by PKI analogs administered i.c.v. is evidence that PKA plays a role in morphine tolerance.

Modeling of frequency agile devices: development of PKI neuromodeling library based on hierarchical network structure

NASA Astrophysics Data System (ADS)

Sanchez, P.; Hinojosa, J.; Ruiz, R.

2005-06-01

Recently, neuromodeling methods of microwave devices have been developed. These methods are suitable for the model generation of novel devices. They allow fast and accurate simulations and optimizations. However, the development of libraries makes these methods to be a formidable task, since they require massive input-output data provided by an electromagnetic simulator or measurements and repeated artificial neural network (ANN) training. This paper presents a strategy reducing the cost of library development with the advantages of the neuromodeling methods: high accuracy, large range of geometrical and material parameters and reduced CPU time. The library models are developed from a set of base prior knowledge input (PKI) models, which take into account the characteristics common to all the models in the library, and high-level ANNs which give the library model outputs from base PKI models. This technique is illustrated for a microwave multiconductor tunable phase shifter using anisotropic substrates. Closed-form relationships have been developed and are presented in this paper. The results show good agreement with the expected ones.

Synthesis, characterization and inhibitory activities of (4-N3[3,5-3H]Phe10)PKI(6-22)amide and its precursors: photoaffinity labeling peptides for the active site of cyclic AMP-dependent protein kinase.

PubMed

Katz, B M; Lundquist, L J; Walsh, D A; Glass, D B

1989-06-01

PKI(6-22)amide is a 17 residue peptide corresponding to the active portion of the heat-stable inhibitor of cAMP-dependent protein kinase. The peptide is a potent (Ki = 1.6 nM), competitive inhibitor of the enzyme. The photoreactive peptide analog (4-azidophenylalanine10)PKI(6-22)amide was synthesized in both its non-radiolabeled and tritiated forms by chemical modification of precursor peptides that were prepared by stepwise solid-phase synthesis. (4-Amino[3,5-3H]phenylalanine10)PKI(6-22)amide, the precursor for the radiolabeled arylazide peptide, was obtained by catalytic reduction of the corresponding peptide containing the 3,5-diiodo-4-aminophenylalanine residue at position 10. The purified PKI peptides were analyzed by HPLC, amino acid analysis, and u.v. spectra. In the dark, (4-azidophenylalanine10)PKI(6-22)amide inhibited the catalytic subunit of cAMP-dependent protein kinase with a Ki value of 2.8 nM. The photoreactivity of the arylazide peptide was demonstrated by time-dependent u.v. spectral changes on exposure to light. Photolysis of the catalytic subunit (4-azido[3,5-3H]phenylalanine10)PKI(6-22)amide complex resulted in specific covalent labeling of the enzyme. The data indicate that this peptide is a useful photoaffinity labeling reagent for the active site of the protein kinase.

J-PAKE: Authenticated Key Exchange without PKI

NASA Astrophysics Data System (ADS)

Hao, Feng; Ryan, Peter

Password Authenticated Key Exchange (PAKE) is one of the important topics in cryptography. It aims to address a practical security problem: how to establish secure communication between two parties solely based on a shared password without requiring a Public Key Infrastructure (PKI). After more than a decade of extensive research in this field, there have been several PAKE protocols available. The EKE and SPEKE schemes are perhaps the two most notable examples. Both techniques are however patented. In this paper, we review these techniques in detail and summarize various theoretical and practical weaknesses. In addition, we present a new PAKE solution called J-PAKE. Our strategy is to depend on well-established primitives such as the Zero-Knowledge Proof (ZKP). So far, almost all of the past solutions have avoided using ZKP for the concern on efficiency. We demonstrate how to effectively integrate the ZKP into the protocol design and meanwhile achieve good efficiency. Our protocol has comparable computational efficiency to the EKE and SPEKE schemes with clear advantages on security.

Higher Education Partners with the Federal Government for PKI: Both Communities Bring Substantial Expertise and Investment to the Solutions.

ERIC Educational Resources Information Center

PKI for Networked Higher Education Working Group.

2000-01-01

One barrier to Web-based education is lack of an effective system to identify and authorize involved participants, content, and institutions. PKI (public-key infrastructure) is an emerging technology that can certify the correct identity of each person and communication in Web-based learning. A June 2000 National Science Foundation workshop…

Design and implementation of a secure workflow system based on PKI/PMI

NASA Astrophysics Data System (ADS)

Yan, Kai; Jiang, Chao-hui

2013-03-01

As the traditional workflow system in privilege management has the following weaknesses: low privilege management efficiency, overburdened for administrator, lack of trust authority etc. A secure workflow model based on PKI/PMI is proposed after studying security requirements of the workflow systems in-depth. This model can achieve static and dynamic authorization after verifying user's ID through PKC and validating user's privilege information by using AC in workflow system. Practice shows that this system can meet the security requirements of WfMS. Moreover, it can not only improve system security, but also ensures integrity, confidentiality, availability and non-repudiation of the data in the system.

The dual PI3K/mTOR inhibitor PKI-587 enhances sensitivity to cetuximab in EGFR-resistant human head and neck cancer models.

PubMed

D'Amato, V; Rosa, R; D'Amato, C; Formisano, L; Marciano, R; Nappi, L; Raimondo, L; Di Mauro, C; Servetto, A; Fusciello, C; Veneziani, B M; De Placido, S; Bianco, R

2014-06-10

Cetuximab is the only targeted agent approved for the treatment of head and neck squamous cell carcinomas (HNSCC), but low response rates and disease progression are frequently reported. As the phosphoinositide 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) pathways have an important role in the pathogenesis of HNSCC, we investigated their involvement in cetuximab resistance. Different human squamous cancer cell lines sensitive or resistant to cetuximab were tested for the dual PI3K/mTOR inhibitor PF-05212384 (PKI-587), alone and in combination, both in vitro and in vivo. Treatment with PKI-587 enhances sensitivity to cetuximab in vitro, even in the condition of epidermal growth factor receptor (EGFR) resistance. The combination of the two drugs inhibits cells survival, impairs the activation of signalling pathways and induces apoptosis. Interestingly, although significant inhibition of proliferation is observed in all cell lines treated with PKI-587 in combination with cetuximab, activation of apoptosis is evident in sensitive but not in resistant cell lines, in which autophagy is pre-eminent. In nude mice xenografted with resistant Kyse30 cells, the combined treatment significantly reduces tumour growth and prolongs mice survival. Phosphoinositide 3-kinase/mammalian target of rapamycin inhibition has an important role in the rescue of cetuximab resistance. Different mechanisms of cell death are induced by combined treatment depending on basal anti-EGFR responsiveness.

Application of PKI in health care--needs, ambitions, prospects.

PubMed

Suselj, Marjan; Marcun, Tomaz; Trcek, Denis; Kandus, Gorazd

2003-01-01

Through continual development and considerable investment over the past years, Slovenia has established an information infrastructure providing efficient data links between all the health care actors. This includes furnishing all the citizens and health workers with microprocessor cards--health insurance card and health professional card. These tools have significantly simplified different procedures in the health care and brought services closer to insured persons. The know-how and experiences gathered to day have given rise to vivid discussions of further development steps: introduction of new contents on the infrastructure in place and technological upgrading, in particular progressive incorporation of the PKI concept and thereby integration of card and network solutions to provide an efficient and secure communication environment. This paper outlines key perspectives of the future developments in this segment. With the volume of health care data communications through internet growing steeply, and with the paramount importance of patient--doctor trust and confidence, security tools and solutions in the health care are a critical need.

The dual PI3K/mTOR inhibitor PKI-587 enhances sensitivity to cetuximab in EGFR-resistant human head and neck cancer models

PubMed Central

D'Amato, V; Rosa, R; D'Amato, C; Formisano, L; Marciano, R; Nappi, L; Raimondo, L; Di Mauro, C; Servetto, A; Fusciello, C; Veneziani, B M; De Placido, S; Bianco, R

2014-01-01

Background: Cetuximab is the only targeted agent approved for the treatment of head and neck squamous cell carcinomas (HNSCC), but low response rates and disease progression are frequently reported. As the phosphoinositide 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) pathways have an important role in the pathogenesis of HNSCC, we investigated their involvement in cetuximab resistance. Methods: Different human squamous cancer cell lines sensitive or resistant to cetuximab were tested for the dual PI3K/mTOR inhibitor PF-05212384 (PKI-587), alone and in combination, both in vitro and in vivo. Results: Treatment with PKI-587 enhances sensitivity to cetuximab in vitro, even in the condition of epidermal growth factor receptor (EGFR) resistance. The combination of the two drugs inhibits cells survival, impairs the activation of signalling pathways and induces apoptosis. Interestingly, although significant inhibition of proliferation is observed in all cell lines treated with PKI-587 in combination with cetuximab, activation of apoptosis is evident in sensitive but not in resistant cell lines, in which autophagy is pre-eminent. In nude mice xenografted with resistant Kyse30 cells, the combined treatment significantly reduces tumour growth and prolongs mice survival. Conclusions: Phosphoinositide 3-kinase/mammalian target of rapamycin inhibition has an important role in the rescue of cetuximab resistance. Different mechanisms of cell death are induced by combined treatment depending on basal anti-EGFR responsiveness. PMID:24823695

Public Key Infrastructure (PKI) Increment 2 Root Cause Analysis (RCA) for Performance Assessments and Root Cause Analyses (PARCA)

DTIC Science & Technology

2015-05-01

for issuing this critical change:  Inability to achieve PKI Increment 2 Full Deployment Decision ( FDD ) within five years of program initiation...March 1, 2014 deadline), and  Delay of over one year in the original FDD estimate provided to the Congress (1 March 2014 deadline). The proximate...to support a 1 March 2014 FDD .” The Director, Performance Assessments and Root Cause Analyses (PARCA), asked the Institute for Defense Analyses

Workshop on Pion-Kaon Interactions (PKI2018) Mini-Proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amaryan, M; Pal, Bilas

This volume is a short summary of talks given at the PKI2018 Workshop organized to discuss current status and future prospects of pi -K interactions. The precise data on pi K interaction will have a strong impact on strange meson spectroscopy and form factors that are important ingredients in the Dalitz plot analysis of a decays of heavy mesons as well as precision measurement of Vus matrix element and therefore on a test of unitarity in the first raw of the CKM matrix. The workshop has combined the efforts of experimentalists, Lattice QCD, and phenomenology communities. Experimental data relevant tomore » the topic of the workshop were presented from the broad range of different collaborations like CLAS, GlueX, COMPASS, BaBar, BELLE, BESIII, VEPP-2000, and LHCb. One of the main goals of this workshop was to outline a need for a new high intensity and high precision secondary KL beam facility at JLab produced with the 12 GeV electron beam of CEBAF accelerator.« less

Bias-dependent hybrid PKI empirical-neural model of microwave FETs

NASA Astrophysics Data System (ADS)

Marinković, Zlatica; Pronić-Rančić, Olivera; Marković, Vera

2011-10-01

Empirical models of microwave transistors based on an equivalent circuit are valid for only one bias point. Bias-dependent analysis requires repeated extractions of the model parameters for each bias point. In order to make model bias-dependent, a new hybrid empirical-neural model of microwave field-effect transistors is proposed in this article. The model is a combination of an equivalent circuit model including noise developed for one bias point and two prior knowledge input artificial neural networks (PKI ANNs) aimed at introducing bias dependency of scattering (S) and noise parameters, respectively. The prior knowledge of the proposed ANNs involves the values of the S- and noise parameters obtained by the empirical model. The proposed hybrid model is valid in the whole range of bias conditions. Moreover, the proposed model provides better accuracy than the empirical model, which is illustrated by an appropriate modelling example of a pseudomorphic high-electron mobility transistor device.

Plasmids encoding PKI(1-31), a specific inhibitor of cAMP-stimulated gene expression, inhibit the basal transcriptional activity of some but not all cAMP-regulated DNA response elements in JEG-3 cells.

PubMed

Grove, J R; Deutsch, P J; Price, D J; Habener, J F; Avruch, J

1989-11-25

Plasmids that encode a bioactive amino-terminal fragment of the heat-stable inhibitor of the cAMP-dependent protein kinase, PKI(1-31), were employed to characterize the role of this protein kinase in the control of transcriptional activity mediated by three DNA regulatory elements in the JEG-3 human placental cell line. The 5'-flanking sequence of the human collagenase gene contains the heptameric sequence, 5'-TGAGTCA-3', previously identified as a "phorbol ester" response element. Reporter genes containing either the intact 1.2-kilobase 5'-flanking sequence from the human collagenase gene or just the 7-base pair (bp) response element, when coupled to an enhancerless promoter, each exhibit both cAMP and phorbol ester-stimulated expression in JEG-3 cells. Cotransfection of either construct with plasmids encoding PKI(1-31) inhibits cAMP-stimulated but not basal- or phorbol ester-stimulated expression. Pretreatment of cells with phorbol ester for 1 or 2 days abrogates completely the response to rechallenge with phorbol ester but does not alter the basal expression of either construct; cAMP-stimulated expression, while modestly inhibited, remains vigorous. The 5'-flanking sequence of the human chorionic gonadotropin-alpha subunit (HCG alpha) gene has two copies of the sequence, 5'-TGACGTCA-3', contained in directly adjacent identical 18-bp segments, previously identified as a cAMP-response element. Reporter genes containing either the intact 1.5 kilobase of 5'-flanking sequence from the HCG alpha gene, or just the 36-bp tandem repeat cAMP response element, when coupled to an enhancerless promoter, both exhibit a vigorous cAMP stimulation of expression but no response to phorbol ester in JEG-3 cells. Cotransfection with plasmids encoding PKI(1-31) inhibits both basal and cAMP-stimulated expression in a parallel fashion. The 5'-flanking sequence of the human enkephalin gene mediates cAMP-stimulated expression of reporter genes in both JEG-3 and CV-1 cells. Plasmids

Increased expression of protein kinase A inhibitor alpha (PKI-alpha) and decreased PKA-regulated genes in chronic intermittent alcohol exposure.

PubMed

Repunte-Canonigo, Vez; Lutjens, Robert; van der Stap, Lena D; Sanna, Pietro Paolo

2007-03-23

Intermittent models of alcohol exposure that mimic human patterns of alcohol consumption produce profound physiological and biochemical changes and induce rapid increases in alcohol self-administration. We used high-density oligonucleotide microarrays to investigate gene expression changes during chronic intermittent alcohol exposure in three brain regions that receive mesocorticolimbic dopaminergic projections and that are believed to be involved in alcohol's reinforcing actions: the medial prefrontal cortex, the nucleus accumbens and the amygdala. An independent replication of the experiment was used for RT-PCR validation of the microarray results. The protein kinase A inhibitor alpha (PKI-alpha, Pkia), a member of the endogenous PKI family implicated in reducing nuclear PKA activity, was found to be increased in all three regions tested. Conversely, we observed a downregulation of the expression of several PKA-regulated transcripts in one or more of the brain regions studied, including the activity and neurotransmitter-regulated early gene (Ania) - 1, -3, -7, -8, the transcription factors Egr1 and NGFI-B (Nr4a1) and the neuropeptide NPY. Reduced expression of PKA-regulated genes in mesocorticolimbic projection areas may have motivational significance in the rapid increase in alcohol self-administration induced by intermittent alcohol exposure.

Authentication Architecture for Region-Wide e-Health System with Smartcards and a PKI

NASA Astrophysics Data System (ADS)

Zúquete, André; Gomes, Helder; Cunha, João Paulo Silva

This paper describes the design and implementation of an e-Health authentication architecture using smartcards and a PKI. This architecture was developed to authenticate e-Health Professionals accessing the RTS (Rede Telemática da Saúde), a regional platform for sharing clinical data among a set of affiliated health institutions. The architecture had to accommodate specific RTS requirements, namely the security of Professionals' credentials, the mobility of Professionals, and the scalability to accommodate new health institutions. The adopted solution uses short-lived certificates and cross-certification agreements between RTS and e-Health institutions for authenticating Professionals accessing the RTS. These certificates carry as well the Professional's role at their home institution for role-based authorization. Trust agreements between e-Health institutions and RTS are necessary in order to make the certificates recognized by the RTS. As a proof of concept, a prototype was implemented with Windows technology. The presented authentication architecture is intended to be applied to other medical telematic systems.

Complex inner core boundary from frequency characteristics of the reflection coefficients of PKiKP waves observed by Hi-net

NASA Astrophysics Data System (ADS)

Tanaka, Satoru; Tkalčić, Hrvoje

2015-12-01

Frequency-dependent reflection coefficients of P waves at the inner core boundary (ICB) are estimated from the spectral ratios of PKiKP and PcP waves observed by the high-sensitivity seismograph network (Hi-net) in Japan. The corresponding PKiKP reflection locations at the ICB are distributed beneath the western Pacific. At frequencies where noise levels are sufficiently low, spectra of reflection coefficients show four distinct sets of characteristics: a flat spectrum, a spectrum with a significant spectral hole at approximately 1 or 3 Hz, a spectrum with a strong peak at approximately 2 or 3 Hz, and a spectrum containing both a sharp peak and a significant hole. The variety in observed spectra suggests complex lateral variations in ICB properties. To explain the measured differences in frequency characteristics of ICB reflection coefficients, we conduct 2D finite difference simulations of seismic wavefields near the ICB. The models tested in our simulations include a liquid layer and a solid layer above the ICB, as well as sinusoidal and spike-shaped ICB topography with varying heights and scale lengths. We find that the existence of a layer above the ICB can be excluded as a possible explanation for the observed spectra. Furthermore, we find that an ICB topographic model with wavelengths and heights of several kilometers is too extreme to explain our measurements. However, restricting the ICB topography to wavelengths and heights of 1.0-1.5 km can explain the observed frequency-related phenomena. The existence of laterally varying topography may be a sign of lateral variations in inner core solidification.

PKI-based secure mobile access to electronic health services and data.

PubMed

Kambourakis, G; Maglogiannis, I; Rouskas, A

2005-01-01

Recent research works examine the potential employment of public-key cryptography schemes in e-health environments. In such systems, where a Public Key Infrastructure (PKI) is established beforehand, Attribute Certificates (ACs) and public key enabled protocols like TLS, can provide the appropriate mechanisms to effectively support authentication, authorization and confidentiality services. In other words, mutual trust and secure communications between all the stakeholders, namely physicians, patients and e-health service providers, can be successfully established and maintained. Furthermore, as the recently introduced mobile devices with access to computer-based patient record systems are expanding, the need of physicians and nurses to interact increasingly with such systems arises. Considering public key infrastructure requirements for mobile online health networks, this paper discusses the potential use of Attribute Certificates (ACs) in an anticipated trust model. Typical trust interactions among doctors, patients and e-health providers are presented, indicating that resourceful security mechanisms and trust control can be obtained and implemented. The application of attribute certificates to support medical mobile service provision along with the utilization of the de-facto TLS protocol to offer competent confidentiality and authorization services is also presented and evaluated through experimentation, using both the 802.11 WLAN and General Packet Radio Service (GPRS) networks.

Establishment and antitumor effects of dasatinib and PKI-587 in BD-138T, a patient-derived muscle invasive bladder cancer preclinical platform with concomitant EGFR amplification and PTEN deletion

PubMed Central

Lim, Joung Eun; Jeong, Da Eun; Song, Hye Jin; Kim, Sudong; Nam, Do-Hyun; Sung, Hyun Hwan; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun

2016-01-01

Muscle-invasive bladder cancer (MIBC) consists of a heterogeneous group of tumors with a high rate of metastasis and mortality. To facilitate the in-depth investigation and validation of tailored strategies for MIBC treatment, we have developed an integrated approach using advanced high-throughput drug screening and a clinically relevant patient-derived preclinical platform. We isolated patient-derived tumor cells (PDCs) from a rare MIBC case (BD-138T) that harbors concomitant epidermal growth factor receptor (EGFR) amplification and phosphatase and tensin homolog (PTEN) deletion. High-throughput in vitro drug screening demonstrated that dasatinib, a SRC inhibitor, and PKI-587, a dual PI3K/mTOR inhibitor, exhibited targeted anti-proliferative and pro-apoptotic effects against BD-138T PDCs. Using established patient-derived xenograft models that successfully retain the genomic and molecular characteristics of the parental tumor, we confirmed that these anti-tumor responses occurred through the inhibition of SRC and PI3K/AKT/mTOR signaling pathways. Taken together, these experimental results demonstrate that dasatinib and PKI-587 might serve as promising anticancer drug candidates for treating MIBC with combined EGFR gene amplification and PTEN deletion. PMID:27438149

Establishment and antitumor effects of dasatinib and PKI-587 in BD-138T, a patient-derived muscle invasive bladder cancer preclinical platform with concomitant EGFR amplification and PTEN deletion.

PubMed

Chang, Nakho; Lee, Hye Won; Lim, Joung Eun; Jeong, Da Eun; Song, Hye Jin; Kim, Sudong; Nam, Do-Hyun; Sung, Hyun Hwan; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun

2016-08-09

Muscle-invasive bladder cancer (MIBC) consists of a heterogeneous group of tumors with a high rate of metastasis and mortality. To facilitate the in-depth investigation and validation of tailored strategies for MIBC treatment, we have developed an integrated approach using advanced high-throughput drug screening and a clinically relevant patient-derived preclinical platform. We isolated patient-derived tumor cells (PDCs) from a rare MIBC case (BD-138T) that harbors concomitant epidermal growth factor receptor (EGFR) amplification and phosphatase and tensin homolog (PTEN) deletion. High-throughput in vitro drug screening demonstrated that dasatinib, a SRC inhibitor, and PKI-587, a dual PI3K/mTOR inhibitor, exhibited targeted anti-proliferative and pro-apoptotic effects against BD-138T PDCs. Using established patient-derived xenograft models that successfully retain the genomic and molecular characteristics of the parental tumor, we confirmed that these anti-tumor responses occurred through the inhibition of SRC and PI3K/AKT/mTOR signaling pathways. Taken together, these experimental results demonstrate that dasatinib and PKI-587 might serve as promising anticancer drug candidates for treating MIBC with combined EGFR gene amplification and PTEN deletion.

Scientific Grid activities and PKI deployment in the Cybermedia Center, Osaka University.

PubMed

Akiyama, Toyokazu; Teranishi, Yuuichi; Nozaki, Kazunori; Kato, Seiichi; Shimojo, Shinji; Peltier, Steven T; Lin, Abel; Molina, Tomas; Yang, George; Lee, David; Ellisman, Mark; Naito, Sei; Koike, Atsushi; Matsumoto, Shuichi; Yoshida, Kiyokazu; Mori, Hirotaro

2005-10-01

The Cybermedia Center (CMC), Osaka University, is a research institution that offers knowledge and technology resources obtained from advanced researches in the areas of large-scale computation, information and communication, multimedia content and education. Currently, CMC is involved in Japanese national Grid projects such as JGN II (Japan Gigabit Network), NAREGI and BioGrid. Not limited to Japan, CMC also actively takes part in international activities such as PRAGMA. In these projects and international collaborations, CMC has developed a Grid system that allows scientists to perform their analysis by remote-controlling the world's largest ultra-high voltage electron microscope located in Osaka University. In another undertaking, CMC has assumed a leadership role in BioGrid by sharing its experiences and knowledge on the system development for the area of biology. In this paper, we will give an overview of the BioGrid project and introduce the progress of the Telescience unit, which collaborates with the Telescience Project led by the National Center for Microscopy and Imaging Research (NCMIR). Furthermore, CMC collaborates with seven Computing Centers in Japan, NAREGI and National Institute of Informatics to deploy PKI base authentication infrastructure. The current status of this project and future collaboration with Grid Projects will be delineated in this paper.

Cell-cycle-dependent three-dimensional redistribution of nuclear proteins, P 120, pKi-67, and SC 35 splicing factor, in the presence of the topoisomerase I inhibitor camptothecin.

PubMed

Elias, Emmanuel; Lalun, Nathalie; Lorenzato, Marianne; Blache, Laurent; Chelidze, Pavel; O'Donohue, Marie-Françoise; Ploton, Dominique; Bobichon, Hélène

2003-11-15

Topoisomerase I (Topo I) is mostly known for its role in DNA relaxation, which is required for duplication and transcription. Topo I acts as a protein kinase mainly directed to the mRNA splicing factor SC35. Camptothecin is one of the specific Topo I inhibitors and is effective on the two functions of the enzyme. In this study we demonstrated that treatment of KB cells with camptothecin for only 30 min induced the 3D reorganization and redistribution of three proteins involved in the nucleus machinery, P 120, pKi-67, and SC 35, and this occurred in a cell cycle-dependent manner. Our data were obtained from confocal microscopic studies after immunolabeling, 3D reconstruction, and measurement of the nuclear components volumes. In the presence of camptothecin, P 120, which occupied the nucleolar volume, lost its reticulation and pKi-67 was redistributed within the nucleoplasm and even into the cytoplasm. Finally, for SC 35 the fusion of its dots into bigger volumes was observed specifically during the G1 phase. Variations of volumes were also observed for the nucleolus and for the nucleus. These results pointed out that, depending on the cell cycle phase, Topo I functions were selective toward the three different proteins.

Identification of cellular targets involved in cardiac failure caused by PKI in oncology: an approach combining pharmacovigilance and pharmacodynamics.

PubMed

Patras de Campaigno, Emilie; Bondon-Guitton, Emmanuelle; Laurent, Guy; Montastruc, Francois; Montastruc, Jean-Louis; Lapeyre-Mestre, Maryse; Despas, Fabien

2017-07-01

The aims of the present study were to evaluate the risk of cardiac failure (CF) associated with 15 anticancer protein kinase inhibitors (PKIs) through a case/noncase analysis and to identify which PK(s) and pathways are involved in PKI-induced CF. In order to evaluate the risk of CF, adjusted reporting odds ratios (aRORs) were calculated for the 15 anticancer PKIs in the World Health Organization safety report database (VigiBase®). We realised a literature review to identify 21 protein kinases (PKs) that were possibly involved in CF caused by PKIs. Pearson correlation coefficients (r) between aRORs and affinity data of the 15 PKIs for the 21 PKs were calculated to identify the cellular target most likely to be involved in PKI-induced CF. A total of 141 601 individual case safety reports (ICSRs) were extracted from VigiBase® for the following PKIs: afatinib, axitinib, bosutinib, crizotinib, dasatinib, erlotinib, gefitinib, imatinib, lapatinib, nilotinib, pazopanib, ruxolitinib, sorafenib, sunitinib and vandetanib. Among them, 2594 ICSRs concerned CF. The disproportionality analysis revealed that, for dasatinib, imatinib, bosutinib, sunitinib and nilotinib, disproportionality for CF was significantly higher than for other PKIs, with aRORs of 2.52 [95% CI 2.26, 2.82], 1.79 (95% CI 1.57, 2.03), 1.73 (95% CI 1.18, 2.54), 1.67 (95% CI 1.51, 1.84) and 1.38 (95% CI 1.18, 1.61), respectively. Significant values for correlation coefficients between the product of dissociation constant (pKd) and aROR were observed for two non-receptor protein kinases: ABL1 (non-phosphorylated and phosphorylated forms) and ABL2 protein kinases, with values of r = 0.83 (P = 0.0001), r = 0.75 (P = 0.0014) and r = 0.78 (P = 0.0006), respectively. We observed a higher disproportionality for CF with dasatinib, imatinib, bosutinib, sunitinib and nilotinib than with other PKIs. In addition, the study highlighted the role of ABL tyrosine kinases in CF caused by anticancer PKIs. © 2017 The British

Lead optimization of N-3-substituted 7-morpholinotriazolopyrimidines as dual phosphoinositide 3-kinase/mammalian target of rapamycin inhibitors: discovery of PKI-402.

PubMed

Dehnhardt, Christoph M; Venkatesan, Aranapakam M; Delos Santos, Efren; Chen, Zecheng; Santos, Osvaldo; Ayral-Kaloustian, Semiramis; Brooijmans, Natasja; Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Chaudhary, Inder; Yu, Ker; Gibbons, Jay; Abraham, Robert; Mansour, Tarek S

2010-01-28

Herein we describe the identification and lead optimization of triazolopyrimidines as a novel class of potent dual PI3K/mTOR inhibitors, resulting in the discovery of 3 (PKI-402). Compound 3 exhibits good physical properties and PK parameters, low nanomolar potency against PI3Kalpha and mTOR, and excellent inhibition of cell proliferation in several human cancer cell lines. Furthermore, in vitro and in vivo biomarker studies demonstrated the ability of 3 to shut down the PI3K/Akt pathway and induce apoptosis in cancer cells. In addition, 3 showed excellent in vivo efficacy in various human cancer xenografts, validating suppression of PI3K/mTOR signaling as a potential anticancer therapy.

Stereoselective synthesis of an active metabolite of the potent PI3 kinase inhibitor PKI-179.

PubMed

Chen, Zecheng; Venkatesan, Aranapakam M; Dos Santos, Osvaldo; Delos Santos, Efren; Dehnhardt, Christoph M; Ayral-Kaloustian, Semiramis; Ashcroft, Joseph; McDonald, Leonard A; Mansour, Tarek S

2010-03-05

The synthesis and stereochemical determination of 1-(4-(4-((1R,5R,6R)-6-hydroxy-3-oxa-8-azabicyclo[3.2.1]octan-8-yl)-6-morpholino-1,3,5-triazin-2-yl)phenyl)-3-(pyridin-4-yl)urea (2), an active metabolite of the potent PI3 kinase inhibitor PKI-179 (1), is described. Stereospecific hydroboration of the double bond of 2,5-dihydro-1H-pyrrole 8 gave the 2,3-trans alcohol 9 exclusively. The configuration of the 3-hydroxyl group in 9 was inverted by an oxidation and stereoselective reduction sequence to give the corresponding 2,3-cis isomer 23. Both exo (21) and endo (27) isomers of the metabolite 2 were prepared via a practical synthetic route from 9 and 23, respectively, and the stereochemistry of 2 was determined to be endo. The endo isomer (27) was separated into two enantiomers 28 and 29 by chiral HPLC. Compound 2 was found to be enantiomerically pure and identical to the enantiomer 28. The absolute stereochemistry of the enantiomer 28 was determined by Mosher's method, thus establishing the stereochemistry of the active metabolite 2.

Measuring pKa of activation and pKi of inactivation for influenza hemagglutinin from kinetics of membrane fusion of virions and of HA expressing cells.

PubMed

Mittal, Aditya; Shangguan, Tong; Bentz, Joe

2002-11-01

The data for the pH dependence of lipid mixing between influenza virus (A/PR/8/34 strain) and fluorescently labeled liposomes containing gangliosides has been analyzed using a comprehensive mass action kinetic model for hemaglutinin (HA)-mediated fusion. Quantitative results obtained about the architecture of HA-mediated membrane fusion site from this analysis are in agreement with the previously reported results from analyses of data for HA-expressing cells fusing with various target membranes. Of the eight or more HAs forming a fusogenic aggregate, only two have to undergo the "essential" conformational change needed to initiate fusion. The mass action kinetic model has been extended to allow the analysis of the pKa for HA activation and pKi for HA inactivation. Inactivation and activation of HA following protonation were investigated for various experimental systems involving different strains of HA (A/PR/8/34, X:31, A/Japan). We find that the pKa for the final protonation site on each monomer of the trimer molecule is 5.6 to 5.7, irrespective of the strain. We also find that the pKi for the PR/8 strain is 4.8 to 4.9. The inactivation rate constants for HA, measured from experiments done with PR/8 virions fusing with liposomes and X:31 HA-expressing cells fusing with red blood cells, were both found to be of the order of 10(-4) s(-1). This number appears to be the minimal rate for HA's essential conformational change at low HA surface density. At high HA surface densities, we find evidence for cooperativity in the conformational change, as suggested by other studies.

Measuring pKa of activation and pKi of inactivation for influenza hemagglutinin from kinetics of membrane fusion of virions and of HA expressing cells.

PubMed Central

Mittal, Aditya; Shangguan, Tong; Bentz, Joe

2002-01-01

The data for the pH dependence of lipid mixing between influenza virus (A/PR/8/34 strain) and fluorescently labeled liposomes containing gangliosides has been analyzed using a comprehensive mass action kinetic model for hemaglutinin (HA)-mediated fusion. Quantitative results obtained about the architecture of HA-mediated membrane fusion site from this analysis are in agreement with the previously reported results from analyses of data for HA-expressing cells fusing with various target membranes. Of the eight or more HAs forming a fusogenic aggregate, only two have to undergo the "essential" conformational change needed to initiate fusion. The mass action kinetic model has been extended to allow the analysis of the pKa for HA activation and pKi for HA inactivation. Inactivation and activation of HA following protonation were investigated for various experimental systems involving different strains of HA (A/PR/8/34, X:31, A/Japan). We find that the pKa for the final protonation site on each monomer of the trimer molecule is 5.6 to 5.7, irrespective of the strain. We also find that the pKi for the PR/8 strain is 4.8 to 4.9. The inactivation rate constants for HA, measured from experiments done with PR/8 virions fusing with liposomes and X:31 HA-expressing cells fusing with red blood cells, were both found to be of the order of 10(-4) s(-1). This number appears to be the minimal rate for HA's essential conformational change at low HA surface density. At high HA surface densities, we find evidence for cooperativity in the conformational change, as suggested by other studies. PMID:12414698

Vascular endothelial cells express isoforms of protein kinase A inhibitor.

PubMed

Lum, Hazel; Hao, Zengping; Gayle, Dave; Kumar, Priyadarsini; Patterson, Carolyn E; Uhler, Michael D

2002-01-01

The expression and function of the endogenous inhibitor of cAMP-dependent protein kinase (PKI) in endothelial cells are unknown. In this study, overexpression of rabbit muscle PKI gene into endothelial cells inhibited the cAMP-mediated increase and exacerbated thrombin-induced decrease in endothelial barrier function. We investigated PKI expression in human pulmonary artery (HPAECs), foreskin microvessel (HMECs), and brain microvessel endothelial cells (HBMECs). RT-PCR using specific primers for human PKI alpha, human PKI gamma, and mouse PKI beta sequences detected PKI alpha and PKI gamma mRNA in all three cell types. Sequencing and BLAST analysis indicated that forward and reverse DNA strands for PKI alpha and PKI gamma were of >96% identity with database sequences. RNase protection assays showed protection of the 542 nucleotides in HBMEC and HPAEC PKI alpha mRNA and 240 nucleotides in HBMEC, HPAEC, and HMEC PKI gamma mRNA. Western blot analysis indicated that PKI gamma protein was detected in all three cell types, whereas PKI alpha was found in HBMECs. In summary, endothelial cells from three different vascular beds express PKI alpha and PKI gamma, which may be physiologically important in endothelial barrier function.

An assessment of PKI and networked electronic patient record system: lessons learned from real patient data exchange at the platform of OCHIS (Osaka Community Healthcare Information System).

PubMed

Takeda, Hiroshi; Matsumura, Yasushi; Kuwata, Shigeki; Nakano, Hirohiko; Shanmai, Ji; Qiyan, Zhang; Yufen, Chen; Kusuoka, Hideo; Matsuoka, Masaki

2004-03-31

To enhance medical cooperation between the hospitals and clinics around Osaka local area, the healthcare network system, named Osaka Community Healthcare Information System (OCHIS), was established with support of a supplementary budget from the Japanese government in fiscal year 2002. Although the system has been based on healthcare public key infrastructure (PKI), there remain security issues to be solved technically and operationally. An experimental study was conducted to elucidate the central and the local function in terms of a registration authority and a time stamp authority in contract with the Japanese Medical Information Systems Organization (MEDIS) in 2003. This paper describes the experimental design and the results of the study concerning message security.

Detectability of temporal changes in fine structures near the inner core boundary beneath the eastern hemisphere

NASA Astrophysics Data System (ADS)

Yu, Wen-che

2016-04-01

The inner core boundary (ICB), where melting and solidification of the core occur, plays a crucial role in the dynamics of the Earth's interior. To probe temporal changes near the ICB beneath the eastern hemisphere, I analyze differential times of PKiKP (dt(PKiKP)), double differential times of PKiKP-PKPdf, and PKiKP coda waves from repeating earthquakes in the Southwest Pacific subduction zones. Most PKiKP differential times are within ±30 ms, comparable to inherent travel time uncertainties due to inter-event separations, and suggest no systematic changes as a function of calendar time. Double differential times measured between PKiKP codas and PKiKP main phases show promising temporal changes, with absolute values of time shifts of >50 ms for some observations. However, there are discrepancies among results from different seismographs in the same calendar time window. Negligible changes in PKiKP times, combined with changes in PKiKP coda wave times on 5 year timescales, favor a smooth inner core boundary with fine-scale structures present in the upper inner core. Differential times of PKiKP can be interpreted in the context of either melting based on translational convection, or growth based on thermochemical mantle-inner core coupling. Small dt(PKiKP) values with inherent uncertainties do not have sufficient resolution to distinguish the resultant longitudinal (melting) and latitudinal (growth) dependencies predicted on the basis of the two models on 5 year timescales.

Optimization for the blockade of epidermal growth factor receptor signaling for therapy of human pancreatic carcinoma.

PubMed

Solorzano, C C; Baker, C H; Tsan, R; Traxler, P; Cohen, P; Buchdunger, E; Killion, J J; Fidler, I J

2001-08-01

We determined the optimal administration schedule of a novel epidermal growth factor receptor (EGFR) protein tyrosine kinase inhibitor (PKI), PKI 166 (4-(R)-phenethylamino-6-(hydroxyl)phenyl-7H-pyrrolo[2.3-d]-pyrimidine), alone or in combination with gemcitabine (administered i.p.) for therapy of L3.6pl human pancreatic carcinoma growing in the pancreas of nude mice. Seven days after orthotopic implantation of L3.6pl cells, the mice received daily oral doses of PKI 166. PKI 166 therapy significantly inhibited phosphorylation of the EGFR without affecting EGFR expression. EGFR phosphorylation was restored 72 h after cessation of therapy. Seven days after orthotopic injection of L3.6pl cells, groups of mice received daily or thrice weekly oral doses of PKI 166 alone or in combination with gemcitabine. Treatment with PKI 166 (daily), PKI 166 (3 times/week), or gemcitabine alone produced a 72%, 69%, or 70% reduction in the volume of pancreatic tumors in mice, respectively. Daily oral PKI 166 or thrice weekly oral PKI 166 in combination with injected gemcitabine produced 97% and 95% decreases in volume of pancreatic cancers and significant inhibition of lymph node and liver metastasis. Daily oral PKI 166 produced a 20% decrease in body weight, whereas treatment 3 times/week did not. Decreased microvessel density, decreased proliferating cell nuclear antigen staining, and increased tumor cell and endothelial cell apoptosis correlated with therapeutic success. Collectively, our results demonstrate that three weekly oral administrations of an EGFR tyrosine kinase inhibitor in combination with gemcitabine are sufficient to significantly inhibit primary and metastatic human pancreatic carcinoma.

Expression of the proliferation marker Ki-67 during early mouse development.

PubMed

Winking, H; Gerdes, J; Traut, W

2004-01-01

In somatic tissues, the mouse Ki-67 protein (pKi-67) is expressed in proliferating cells only. Depending on the stage of the cell cycle, pKi-67 is associated with different nuclear domains: with euchromatin as part of the perichromosomal layer, with centromeric heterochromatin, and with the nucleolus. In gametes, sex-specific expression is evident. Mature MII oocytes contain pKi-67, whereas pKi-67 is not detectable in mature sperm. We investigated the re-establishment of the cell cycle-dependent distribution of pKi-67 during early mouse development. After fertilization, male and female pronuclei exhibited very little or no pKi-67, while polar bodies were pKi-67 positive. Towards the end of the first cell cycle, prophase chromosomes of male and female pronuclei simultaneously got decorated with pKi-67. In 2-cell embryos, the distribution pattern changed, presumably depending on the progress of development of the embryo, from a distribution all over the nucleus to a preferential location in the nucleolus precursor bodies (NPBs). From the 4-cell stage onwards, pKi-67 showed the regular nuclear relocations known from somatic tissues: during mitosis the protein was found covering the chromosome arms as a constituent of the perichromosomal layer, in early G1 it was distributed in the whole nucleus, and for the rest of the cell cycle it was associated with NPBs or with the nucleolus. Copyright 2004 S. Karger AG, Basel

Bis(morpholino-1,3,5-triazine) derivatives: potent adenosine 5'-triphosphate competitive phosphatidylinositol-3-kinase/mammalian target of rapamycin inhibitors: discovery of compound 26 (PKI-587), a highly efficacious dual inhibitor.

PubMed

Venkatesan, Aranapakam M; Dehnhardt, Christoph M; Delos Santos, Efren; Chen, Zecheng; Dos Santos, Osvaldo; Ayral-Kaloustian, Semiramis; Khafizova, Gulnaz; Brooijmans, Natasja; Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Yu, Ker; Gibbons, James; Abraham, Robert T; Chaudhary, Inder; Mansour, Tarek S

2010-03-25

The PI3K/Akt signaling pathway is a key pathway in cell proliferation, growth, survival, protein synthesis, and glucose metabolism. It has been recognized recently that inhibiting this pathway might provide a viable therapy for cancer. A series of bis(morpholino-1,3,5-triazine) derivatives were prepared and optimized to provide the highly efficacious PI3K/mTOR inhibitor 1-(4-{[4-(dimethylamino)piperidin-1-yl]carbonyl}phenyl)-3-[4-(4,6-dimorpholin-4-yl-1,3,5-triazin-2-yl)phenyl]urea 26 (PKI-587). Compound 26 has shown excellent activity in vitro and in vivo, with antitumor efficacy in both subcutaneous and orthotopic xenograft tumor models when administered intravenously. The structure-activity relationships and the in vitro and in vivo activity of analogues in this series are described.

Investigations into the binding affinities of different human 5-HT4 receptor splice variants.

PubMed

Irving, Helen R; Tochon-Danguy, Nathalie; Chinkwo, Kenneth A; Li, Jian G; Grabbe, Carmen; Shapiro, Marina; Pouton, Colin W; Coupar, Ian M

2010-01-01

This study examined whether the drug-receptor-binding sites of 5 selected human 5-HT(4) receptor splice variants [h5-HT4(a), h5-HT4(b), h5-HT4(c), h5-HT4(d) and h5-HT4(g)] display preferential affinities towards agonists. The agonists selected on the basis of chemical diversity and clinical relevance were: 5-HT4 benzamides, renzapride, zacopride and prucalopride; the benzimidazolones, DAU 6236 and BIMU 1; the aromatic ketone, RS67333, and the indole carbazimidamide tegaserod. The rank order of affinities ranging across the splice variants was: tegaserod (pKi: 7.38-7.91) > or = Y-36912 (pKi: 7.03-7.85) = BIMU 1 (pKi: 6.92-7.78) > or = DAU 6236 (pKi: 6.79-7.99) > or = 5-HT (pKi: 5.82-7.29) > or = 5-MeOT (pKi: 5.64-6.83) > or = renzapride (pKi: 4.85-5.56). We obtained affinity values for the 5-HT4(b), (d) and (g) variants for RS67333 (pKi: 7:48-8.29), prucalopride (pKi: 6.86-7.37) and zacopride (pKi: 5.88-7.0). These results indicate that the ligands interact with the same conserved site in each splice variant. Some splice variants have a higher affinity for certain agonists and the direction of selectivity followed a common trend of lowest affinity at the (d) variant. However, this trend was not evident in functional experiments. Our findings suggest that it may be possible to design splice variant selective ligands, which may be of relevance for experimental drugs but may be difficult to develop clinically. 2010 S. Karger AG, Basel.

Ki-67 protein is associated with ribosomal RNA transcription in quiescent and proliferating cells.

PubMed

Bullwinkel, Jörn; Baron-Lühr, Bettina; Lüdemann, Anja; Wohlenberg, Claudia; Gerdes, Johannes; Scholzen, Thomas

2006-03-01

The nuclear Ki-67 protein (pKi-67) has previously been shown to be exclusively expressed in proliferating cells. As a result, antibodies against this protein are widely used as prognostic tools in cancer diagnostics. Here we show, that despite the strong downregulation of pKi-67 expression in non-proliferating cells, the protein can nevertheless be detected at sites linked to ribosomal RNA (rRNA) synthesis. Although this finding does not argue against the use of pKi-67 as a proliferation marker, it has wide ranging implications for the elucidation of pKi-67 function. Employing the novel antibody TuBB-9, we could further demonstrate that also in proliferating cells, a fraction of pKi-67 is found at sites linked to the rRNA transcription machinery during interphase and mitosis. Moreover, chromatin immunoprecipitation (ChIP) assays provided evidence for a physical association of pKi-67 with chromatin of the promoter and transcribed region of the rRNA gene cluster. These data strongly suggest a role for pKi-67 in the early steps of rRNA synthesis. Copyright 2005 Wiley-Liss, Inc.

The temporal and spatial distribution of the proliferation associated Ki-67 protein during female and male meiosis.

PubMed

Traut, Walther; Endl, Elmar; Scholzen, Thomas; Gerdes, Johannes; Winking, Heinz

2002-09-01

We used immunolocalization in tissue sections and cytogenetic preparations of female and male gonads to study the distribution of the proliferation marker pKi-67 during meiotic cell cycles of the house mouse, Mus musculus. During male meiosis, pKi-67 was continuously present in nuclei of all stages from the spermatogonium through spermatocytes I and II up to the earliest spermatid stage (early round spermatids) when it appeared to fade out. It was not detected in later spermatid stages or sperm. During female meiosis, pKi-67 was present in prophase I oocytes of fetal ovaries. It was absent in oocytes from newborn mice and most oocytes of primordial follicles from adults. The Ki-67 protein reappeared in oocytes of growing follicles and was continuously present up to metaphase II. Thus, pKi-67 was present in all stages of cell growth and cell division while it was absent from resting oocytes and during the main stages of spermiocytogenesis. Progression through the meiotic cell cycle was associated with extensive intranuclear relocation of pKi-67. In the zygotene and pachytene stages, most of the pKi-67 colocalized with centromeric (centric and pericentric) heterochromatin and adjacent nucleoli; the heterochromatic XY body in male pachytene, however, was free of pKi-67. At early diplotene, pKi-67 was mainly associated with nucleoli. At late diplotene, diakinesis, metaphase I and metaphase II of meiosis, pKi-67 preferentially bound to the perichromosomal layer and was almost absent from the heterochromatic centromeric regions of the chromosomes. After the second division of male meiosis, the protein reappeared at the centromeric heterochromatin and an adjacent region in the earliest spermatid stage and then faded out. The general patterns of pKi-67 distribution were comparable to those in mitotic cell cycles. With respect to the timing, it is interesting to note that relocation from the nucleolus to the perichromosomal layer takes place at the G2/M-phase transition in

Deficient Gene Expression in Protein Kinase Inhibitor α Null Mutant Mice

PubMed Central

Gangolli, Esha A.; Belyamani, Mouna; Muchinsky, Sara; Narula, Anita; Burton, Kimberly A.; McKnight, G. Stanley; Uhler, Michael D.; Idzerda, Rejean L.

2000-01-01

Protein kinase inhibitor (PKI) is a potent endogenous inhibitor of the cyclic AMP (cAMP)-dependent protein kinase (PKA). It functions by binding the free catalytic (C) subunit with a high affinity and is also known to export nuclear C subunit to the cytoplasm. The significance of these actions with respect to PKI's physiological role is not well understood. To address this, we have generated by homologous recombination mutant mice that are deficient in PKIα, one of the three isoforms of PKI. The mice completely lack PKI activity in skeletal muscle and, surprisingly, show decreased basal and isoproterenol-induced gene expression in muscle. Further examination revealed reduced levels of the phosphorylated (active) form of the transcription factor CREB (cAMP response element binding protein) in the knockouts. This phenomenon stems, at least in part, from lower basal PKA activity levels in the mutants, arising from a compensatory increase in the level of the RIα subunit of PKA. The deficit in gene induction, however, is not easily explained by current models of PKI function and suggests that PKI may play an as yet undescribed role in PKA signaling. PMID:10779334

Leishmania major: effect of protein kinase A and phosphodiesterase activity on infectivity and proliferation of promastigotes.

PubMed

Malki-Feldman, Laura; Jaffe, Charles L

2009-09-01

Effect of modulators on protein kinase A (PKA) activity, promastigote growth and their ability to infect peritoneal macrophages was monitored. PKA inhibitors reduced [Protein Kinase Inhibitor (PKI) - 56%; H89 - 54.5%] kemptide phosphorylation by Leishmania major promastigote lysates, while activators increased phosphorylation (8-CPT-cAMP - 88%; Sp-cAMPS-AM - 152%). Activation was specifically inhibited by PKI. Phosphodiesterase inhibitors also increased kemptide phosphorylation (dipyridamole - 171%; rolipram - 106%; and 3-isobutyl-1-methyl-xanthine - 154%). Parasite proliferation was significantly retarded (200 nM H89; 100 microM myristoylated-PKI) or completely inhibited (500 nM H89) by culturing with PKA inhibitors. Incubation with dipyridamole or Sp-cAMPS-AM also inhibited proliferation. Brief treatment (2h) with either H89, myristoylated-PKI, dipyridamole or Sp-cAMPS-AM reduced initial macrophage infection at days 1 and 2 (>40%) and on day 3 (>78% only for 100 microM myr-PKI). Characterization of leishmanial cAMP mediated signal transduction pathways will serve as the basis for the new drug design.

Blockade of epidermal growth factor receptor signaling in tumor cells and tumor-associated endothelial cells for therapy of androgen-independent human prostate cancer growing in the bone of nude mice.

PubMed

Kim, Sun-Jin; Uehara, Hisanori; Karashima, Takashi; Shepherd, David L; Killion, Jerald J; Fidler, Isaiah J

2003-03-01

We determined whether blockade of the epidermal growth factor receptor (EGF-R) signaling pathway by oral administration of the EGF-R tyrosine kinase inhibitor (PKI 166) alone or in combination with injectable Taxol inhibits the growth of PC-3MM2 human prostate cancer cells in the bone of nude mice. Male nude mice implanted with PC-3MM2 cells in the tibia were treated with oral administrations of PKI 166 or PKI 166 plus injectable Taxol beginning 3 days after implantation. The incidence and size of bone tumors and destruction of bone were determined by digitalized radiography. Expression of epidermal growth factor (EGF), EGF-R, and activated EGF-R in tumor cells and tumor-associated endothelial cells was determined by immunohistochemistry. Oral administration of PKI 166 or PKI 166 plus injectable Taxol reduced the incidence and size of bone tumors and destruction of bone. Immunohistochemical analysis revealed that PC-3MM2 cells growing adjacent to the bone expressed high levels of EGF and activated EGF-R, whereas tumor cells in the adjacent musculature did not. Moreover, endothelial cells within the bone tumor lesions, but not in uninvolved bone or tumors in the muscle, expressed high levels of activated EGF-R. Treatment with PKI 166 and more so with PKI 166 plus Taxol significantly inhibited phosphorylation of EGF-R on tumor and endothelial cells and induced significant apoptosis and endothelial cells within tumor lesions. These data indicate that endothelial cells exposed to EGF produced by tumor cells express activated EGF-R and that targeting EGF-R can produce significant therapeutic effects against prostate cancer bone metastasis.

Blockade of epidermal growth factor receptor signaling leads to inhibition of renal cell carcinoma growth in the bone of nude mice.

PubMed

Weber, Kristy L; Doucet, Michele; Price, Janet E; Baker, Cheryl; Kim, Sun Jin; Fidler, Isaiah J

2003-06-01

Renal cell carcinoma (RCC) frequently produces metastases to the musculoskeletal system that are a major source of morbidity in the form of pain, immobilization, fractures, neurological compromise, and a decreased ability to perform activities of daily living. Patients with metastatic RCC therefore have a dismal prognosis because there is no effective adjuvant treatment for this disease. Because the epidermal growth factor receptor (EGF-R) signaling cascade is important in the growth and metastasis of RCC, its blockade has been hypothesized to inhibit tumor growth and hence prevent resultant bone destruction. We determined whether blockade of EGF-R by the tyrosine kinase inhibitor PKI 166 inhibited the growth of RCC in bone. We use a novel cell line, RBM1-IT4, established from a human RCC bone metastasis. Protein and mRNA expression of the ligands and receptors was assessed by Western and Northern blots. The stimulation of RBM1-IT4 cells with epidermal growth factor or transforming growth factor alpha resulted in increased cellular proliferation and tyrosine kinase autophosphorylation. PKI 166 prevented these effects. First, RBM1-IT4 cells were implanted into the tibia of nude mice, where they established lytic, progressively growing lesions, after which the mice were treated with PKI 166 alone or in combination with paclitaxel (Taxol). Immunohistochemical analysis revealed that tumor cells and tumor-associated endothelial cells in control mice expressed activated EGF-R. Treatment of mice with PKI 166 alone or in combination with Taxol produced a significant decrease in the incidence and size of bone lesions as compared with the results in control or Taxol-treated mice (P < 0.001). Treatment with PKI 166 also decreased the expression of phosphorylated EGF-R by tumor cells and tumor-associated endothelial cells, and this was even more pronounced with PKI 166 plus Taxol treatment. The PKI 166 plus Taxol combination produced apoptosis of tumor cells and tumor

Safety profile of protein kinase inhibitors in rheumatoid arthritis: systematic review and meta-analysis.

PubMed

Salgado, Eva; Maneiro, Jose R; Carmona, Loreto; Gomez-Reino, Juan J

2014-05-01

To summarise the adverse events (AE) reported in patients with rheumatoid arthritis (RA) treated with protein kinase inhibitors (PKi), and identify family and molecule-related AEs. Systematic review of the PKi used in clinical trials (CTs) in RA. Medline, Embase, Cochrane Library, Web of Knowledge, and international abstracts of congress were reviewed, (up to 31 October 2012). Search was limited to interventional studies of PKi used in CTs in RA, written in English, and reporting frequencies of AE. Diseases with similar comorbidity burden also were included. Frequency of AE, serious AE (SAE), death and discontinuation due to  AEs (DCAE) were recorded. Risk of bias was assessed. Meta-analysis was carried using pooled relative risk (RR) with 95% CI as effect measure. The search produced 4410 hits. Forty-one articles reporting data on 21 PKi of the Janus kinase (JAK), SYK, p38 and cKit families were selected for detailed analysis. In patients treated with p38 inhibitors, RR for dizziness was 2.36 (1.20 to 4.63), and in patients treated with c-Kit inhibitors, RR for oedema was 3.43 (1.58 to 7.42). In patients treated with the JAK inhibitor tofacitinib, RR for hypercholesterolaemia was 1.70 (1.10 to 2.63) that was dose related. In patients treated with the Syk inhibitor fostamatinib, pooled RR for hypertransaminasaemia, hypertension, diarrhoea and neutropenia were 2.93 (1.02 to 8.43), 2.80 (1.58 to 5.99), 5.20 (3.19 to 8.49) and 9.24 (2.22 to 38.42), respectively. Serious infections and malignancies were not significantly more frequent in PKi-treated patients than in comparator groups. Event rates of serious infections and malignancies with PKi are not different from biologics. In addition, PKi have a unique safety profile related to target and off-target inhibition of kinases, at times dose related.

Targeted light-inactivation of the Ki-67 protein using theranostic liposomes leads to death of proliferating cells

NASA Astrophysics Data System (ADS)

Rahmanzadeh, Ramtin; Rai, Prakash; Gerdes, Johannes; Hasan, Tayyaba

2010-02-01

Nanomedicine is beginning to impact the treatment of several diseases and current research efforts include development of integrated nano-constructs (theranostics) which serve as probes for imaging and therapy in addition to delivering macromolecules intracellularly. In cancer, there is a vital unmet need for effective alternative treatments with high specificity and low systemic toxicity. This can be achieved by targeting key molecular markers associated with cancer cells with reduced effective drug doses. Here, we show an innovative proof-of-principle approach for efficient killing of proliferating ovarian cancer cells by inactivating a protein associated with cell proliferation namely, the nuclear Ki-67 protein (pKi-67), using nanotechnology-based photodynamic therapy (PDT). Antibodies against pKi-67 are widely used as prognostic tools for tumor diagnosis. In this work, anti pKi-67 antibodies were first conjugated to fluorescein isothiocyanate (FITC) and then encapsulated inside liposomes. After incubation of OVCAR-5 ovarian cancer cells with these liposomes, confocal microscopy confirmed the localization of the antibodies to the nucleoli of the cells. Irradiation with a 488 nm laser led to a significant loss of cell viability. The specificity of this approach for pKi-67 positive cells was demonstrated in confluent human lung fibroblasts (MRC-5) where only a small population of cells stain positive for pKi-67 and only minimal cell death was observed. Taken together, our findings suggest that pKi-67 targeted with nano-platform is an attractive therapeutic target in cancer therapy.

Crystal structure of a polyhistidine-tagged recombinant catalytic subunit of cAMP-dependent protein kinase complexed with the peptide inhibitor PKI(5-24) and adenosine.

PubMed

Narayana, N; Cox, S; Shaltiel, S; Taylor, S S; Xuong, N

1997-04-15

The crystal structure of the hexahistidine-tagged mouse recombinant catalytic subunit (H6-rC) of cAMP-dependent protein kinase (cAPK), complexed with a 20-residue peptide inhibitor from the heat-stable protein kinase inhibitor PKI(5-24) and adenosine, was determined at 2.2 A resolution. Novel crystallization conditions were required to grow the ternary complex crystals. The structure was refined to a final crystallographic R-factor of 18.2% with good stereochemical parameters. The "active" enzyme adopts a "closed" conformation as found in rC:PKI(5-24) [Knighton et al. (1991a,b) Science 253, 407-414, 414-420] and packs in a similar manner with the peptide providing a major contact surface. This structure clearly defines the subsites of the unique nucleotide binding site found in the protein kinase family. The adenosine occupies a mostly hydrophobic pocket at the base of the cleft between the two lobes and is completely buried. The missing triphosphate moiety of ATP is filled with a water molecule (Wtr 415) which replaces the gamma-phosphate of ATP. The glycine-rich loop between beta1 and beta2 helps to anchor the phosphates while the ribose ring is buried beneath beta-strand 2. Another ordered water molecule (Wtr 375) is pentacoordinated with polar atoms from adenosine, Leu 49 in beta-strand 1, Glu 127 in the linker strand between the two lobes, Tyr 330, and a third water molecule, Wtr 359. The conserved nucleotide fold can be defined as a lid comprised of beta-strand 1, the glycine-rich loop, and beta-strand 2. The adenine ring is buried beneath beta-strand 1 and the linker strand (120-127) that joins the small and large lobes. The C-terminal tail containing Tyr 330, a segment that lies outside the conserved core, covers this fold and anchors it in a closed conformation. The main-chain atoms of the flexible glycine-rich loop (residues 50-55) in the ATP binding domain have a mean B-factor of 41.4 A2. This loop is quite mobile, in striking contrast to the other

Blockade of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling for therapy of metastatic human pancreatic cancer.

PubMed

Baker, Cheryl H; Solorzano, Carmen C; Fidler, Isaiah J

2002-04-01

We determined whether concurrent blockage of vascular endothelial growth factor (VEGF) receptor and epidermal growth factor (EGF) receptor signaling by two novel tyrosine kinase inhibitors, PTK 787 and PKI 166, respectively, can inhibit angiogenesis and, hence, the growth and metastasis of human pancreatic carcinoma in nude mice. Highly metastatic human pancreatic carcinoma L3.6pl cells were injected into the pancreas of nude mice. Seven days later, groups of mice began receiving oral doses of PTK 787 and PKI 166 three times weekly. Some groups of mice also received i.p. injections of gemcitabine twice a week. The mice were necropsied when the control mice became moribund. Treatment with PTK 787 and PKI 166, with gemcitabine alone, or with the combination of PTK 787, PKI 166, and gemcitabine produced 69, 50, and 97% reduction in the volume of pancreatic tumors, respectively. Administration of protein tyrosine kinase inhibitors and gemcitabine also significantly decreased the incidence of lymph node and liver metastasis. The therapeutic efficacy directly correlated with a decrease in circulating proangiogenic molecules (VEGF, interleukin-8), a decrease in microvessel density, a decrease in proliferating cell nuclear antigen staining, and an increase in apoptosis of tumor cells and endothelial cells. Therapies produced by combining gemcitabine with either PKI 166 or PTK 787 were similar to those produced by combining gemcitabine with both PKI 166 and PTK 787. These results suggest that blockade of either epidermal growth factor receptor or VEGF receptor signaling combined with chemotherapy provides an effective approach to the therapy of pancreatic cancer.

Insights into factorless translational initiation by the tRNA-like pseudoknot domain of a viral IRES.

PubMed

Au, Hilda H T; Jan, Eric

2012-01-01

The intergenic region internal ribosome entry site (IGR IRES) of the Dicistroviridae family adopts an overlapping triple pseudoknot structure to directly recruit the 80S ribosome in the absence of initiation factors. The pseudoknot I (PKI) domain of the IRES mimics a tRNA-like codon:anticodon interaction in the ribosomal P site to direct translation initiation from a non-AUG initiation codon in the A site. In this study, we have performed a comprehensive mutational analysis of this region to delineate the molecular parameters that drive IRES translation. We demonstrate that IRES-mediated translation can initiate at an alternate adjacent and overlapping start site, provided that basepairing interactions within PKI remain intact. Consistent with this, IGR IRES translation tolerates increases in the variable loop region that connects the anticodon- and codon-like elements within the PKI domain, as IRES activity remains relatively robust up to a 4-nucleotide insertion in this region. Finally, elements from an authentic tRNA anticodon stem-loop can functionally supplant corresponding regions within PKI. These results verify the importance of the codon:anticodon interaction of the PKI domain and further define the specific elements within the tRNA-like domain that contribute to optimal initiator Met-tRNA(i)-independent IRES translation.

Insights into Factorless Translational Initiation by the tRNA-Like Pseudoknot Domain of a Viral IRES

PubMed Central

Au, Hilda H. T.; Jan, Eric

2012-01-01

The intergenic region internal ribosome entry site (IGR IRES) of the Dicistroviridae family adopts an overlapping triple pseudoknot structure to directly recruit the 80S ribosome in the absence of initiation factors. The pseudoknot I (PKI) domain of the IRES mimics a tRNA-like codon:anticodon interaction in the ribosomal P site to direct translation initiation from a non-AUG initiation codon in the A site. In this study, we have performed a comprehensive mutational analysis of this region to delineate the molecular parameters that drive IRES translation. We demonstrate that IRES-mediated translation can initiate at an alternate adjacent and overlapping start site, provided that basepairing interactions within PKI remain intact. Consistent with this, IGR IRES translation tolerates increases in the variable loop region that connects the anticodon- and codon-like elements within the PKI domain, as IRES activity remains relatively robust up to a 4-nucleotide insertion in this region. Finally, elements from an authentic tRNA anticodon stem-loop can functionally supplant corresponding regions within PKI. These results verify the importance of the codon:anticodon interaction of the PKI domain and further define the specific elements within the tRNA-like domain that contribute to optimal initiator Met-tRNAi-independent IRES translation. PMID:23236506

Interaction of ABC multidrug transporters with anticancer protein kinase inhibitors: substrates and/or inhibitors?

PubMed

Hegedus, Csilla; Ozvegy-Laczka, Csilla; Szakács, Gergely; Sarkadi, Balázs

2009-05-01

Protein kinase inhibitors (PKI) are becoming key agents in modern cancer chemotherapy, and combination of PKIs with classical chemotherapeutic drugs may help to overcome currently untreatable metastatic cancers. Since chemotherapy resistance is a recurrent problem, mechanisms of resistance should be clarified in order to help further drug development. Here we suggest that in addition to PKI resistance based on altered target structures, the active removal of these therapeutic agents by the MDR-ABC transporters should also be considered as a major cause of clinical resistance. We discuss the occurring systemic and cellular mechanisms, which may hamper PKI efficiency, and document the role of selected MDR-ABC transporters in these phenomena through their interactions with these anticancer agents. Moreover, we suggest that PKI interactions with ABC transporters may modulate overall drug metabolism, including the fate of diverse, chemically or target-wise unrelated drugs. These effects are based on multiple forms of MDR-ABC transporter interaction with PKIs, as these compounds may be both substrates and/or inhibitors of an ABC transporter. We propose that these interactions should be carefully considered in clinical application, and a combined MDR-ABC transporter and PKI effect may bring a major advantage in future drug development.

(124)I-iodopyridopyrimidinone for PET of Abl kinase-expressing tumors in vivo.

PubMed

Doubrovin, Mikhail; Kochetkova, Tatiana; Santos, Elmer; Veach, Darren R; Smith-Jones, Peter; Pillarsetty, Nagavarakishore; Balatoni, Julius; Bornmann, William; Gelovani, Juri; Larson, Steven M

2010-01-01

Because of the recent development of an iodopyridopyrimidinone Abl protein kinase inhibitor (PKI), (124)I-SKI-212230 ((124)I-SKI230), we investigated the feasibility of a PET-based molecular imaging method for the direct visualization of Abl kinase expression and PKI treatment. In vitro pharmacokinetic properties, including specific and nonspecific binding of (124)I-SKI230 to its Abl kinase target and interaction with other PKIs, were assessed in cell-free medium and chronic myelogenous leukemia (CML) cells overexpressing BCR-Abl (K562), in comparison with BT-474 cells that are low in Abl expression. In a xenograft tumor model, we assessed the in vivo pharmacokinetics of (124)I-SKI230 using PET and postmortem tissue sampling. We also tested a paradigm of (124)I-SKI230 PET after treatment of the animal with a dose of Abl-specific PKI for the monitoring of the tumor response. In vitro studies confirmed that SKI230 binds to Abl kinase with nanomolar affinity, that selective uptake occurs in cell lines known to express Abl kinase, that RNAi knock-down supports specificity of cellular uptake due to Abl kinase, and that imatinib, an archetype Abl PKI, completely displaces SKI230. With SKI230, we obtained successful in vivo PET of Abl-expressing human tumors in a nude rat. We were also able to demonstrate evidence of substrate inhibition of in vivo radiotracer uptake in the xenograft tumor after treatment of the animal as a model of PKI treatment monitoring. These results support the hypothesis that molecular imaging using PET will be useful for the study of in vivo pharmacodynamics of Abl PKI molecular therapy in humans.

CrossTalk: The Journal of Defense Software Engineering. Volume 22, Number 7, Nov/Dec 2009

DTIC Science & Technology

2009-12-01

an MBA, and is a Certified Corporate Trainer. Booz Allen Hamilton AF PKI SPO 4241 E Piedras DR STE 210 San Antonio,TX 78228 Phone: (210) 925-9129...Certified Secure Software Lifecycle Professional, and a Project Management Professional. General Dynamics C4 Systems AF PKI SPO 4241 E Piedras DR STE 210

Mutation E169K in junctophilin-2 causes atrial fibrillation due to impaired RyR2 stabilization.

PubMed

Beavers, David L; Wang, Wei; Ather, Sameer; Voigt, Niels; Garbino, Alejandro; Dixit, Sayali S; Landstrom, Andrew P; Li, Na; Wang, Qiongling; Olivotto, Iacopo; Dobrev, Dobromir; Ackerman, Michael J; Wehrens, Xander H T

2013-11-19

This study sought to study the role of junctophilin-2 (JPH2) in atrial fibrillation (AF). JPH2 is believed to have an important role in sarcoplasmic reticulum (SR) Ca(2+) handling and modulation of ryanodine receptor Ca(2+) channels (RyR2). Whereas defective RyR2-mediated Ca(2+) release contributes to the pathogenesis of AF, nothing is known about the potential role of JPH2 in atrial arrhythmias. Screening 203 unrelated hypertrophic cardiomyopathy patients uncovered a novel JPH2 missense mutation (E169K) in 2 patients with juvenile-onset paroxysmal AF (pAF). Pseudoknock-in (PKI) mouse models were generated to determine the molecular defects underlying the development of AF caused by this JPH2 mutation. PKI mice expressing E169K mutant JPH2 exhibited a higher incidence of inducible AF than wild type (WT)-PKI mice, whereas A399S-PKI mice expressing a hypertrophic cardiomyopathy-linked JPH2 mutation not associated with atrial arrhythmias were not significantly different from WT-PKI. E169K-PKI but not A399A-PKI atrial cardiomyocytes showed an increased incidence of abnormal SR Ca(2+) release events. These changes were attributed to reduced binding of E169K-JPH2 to RyR2. Atrial JPH2 levels in WT-JPH2 transgenic, nontransgenic, and JPH2 knockdown mice correlated negatively with the incidence of pacing-induced AF. Ca(2+) spark frequency in atrial myocytes and the open probability of single RyR2 channels from JPH2 knockdown mice was significantly reduced by a small JPH2-mimicking oligopeptide. Moreover, patients with pAF had reduced atrial JPH2 levels per RyR2 channel compared to sinus rhythm patients and an increased frequency of spontaneous Ca(2+) release events. Our data suggest a novel mechanism by which reduced JPH2-mediated stabilization of RyR2 due to loss-of-function mutation or reduced JPH2/RyR2 ratios can promote SR Ca(2+) leak and atrial arrhythmias, representing a potential novel therapeutic target for AF. Copyright © 2013. Published by Elsevier Inc.

Mutation E169K in junctophilin-2 causes atrial fibrillation due to impaired RyR2 stabilization

PubMed Central

Voigt, Niels; Garbino, Alejandro; Dixit, Sayali S.; Landstrom, Andrew P.; Li, Na; Wang, Qiongling; Olivotto, Iacopo; Dobrev, Dobromir; Ackerman, Michael J.; Wehrens, Xander H.T.

2013-01-01

Objectives To study the role of junctophilin 2 (JPH2) in atrial fibrillation (AF). Background JPH2 is believed to have an important role in sarcoplasmic reticulum (SR) Ca2+ handling and modulation of ryanodine receptor Ca2+ channels (RyR2). Whereas defective RyR2-mediated Ca2+ release contributes to the pathogenesis of AF, nothing is known about the potential role of JPH2 in atrial arrhythmias. Methods Screening 203 unrelated hypertrophic cardiomyopathy patients uncovered a novel JPH2 missense mutation (E169K) in 2 patients with juvenile-onset paroxysmal AF (pAF). Pseudo-knockin (PKI) mouse models were generated to determine the molecular defects underlying the development of AF caused by this JPH2 mutation. Results PKI mice expressing E169K mutant JPH2 exhibited a higher incidence of inducible AF compared with wildtype (WT)-PKI mice, while A399S-PKI mice expressing a HCM-linked JPH2 mutation not associated with atrial arrhythmias were not significantly different from WT-PKI. E169K-PKI but not A399A-PKI atrial cardiomyocytes showed an increased incidence of abnormal SR Ca2+ release events. These changes were attributed to reduced binding of E169KJPH2 to RyR2. Atrial JPH2 levels in WT-JPH2 transgenic, nontransgenic, and JPH2 knockdown mice correlated negatively with the incidence of pacing-induced AF. Ca2+ spark frequency in atrial myocytes and the open probability of single RyR2 channels from JPH2 knockdown mice was significantly reduced by a small JPH2-mimicking oligopeptide. Moreover, patients with pAF had reduced atrial JPH2 levels per RyR2 channel compared to sinus rhythm patients, and an increased frequency of spontaneous Ca2+ release events. Conclusions Our data suggest a novel mechanism by which reduced JPH2-mediated stabilization of RyR2 due to loss-of-function mutation or reduced JPH2:RyR2 ratios can promote SR Ca2+ leak and atrial arrhythmias, representing a potential novel therapeutic target for AF. PMID:23973696

The design and delivery of a PKA inhibitory polypeptide to treat SCA1.

PubMed

Hearst, Scoty M; Shao, Qingmei; Lopez, Mariper; Raucher, Drazen; Vig, Parminder J S

2014-10-01

Spinocerebellar ataxia-1 (SCA1) is a neurodegenerative disease that primarily targets Purkinje cells (PCs) of the cerebellum. The exact mechanism of PC degeneration is unknown, however, it is widely believed that mutant ataxin-1 becomes toxic because of the phosphorylation of its serine 776 (S776) residue by cAMP-dependent protein kinase A (PKA). Therefore, to directly modulate mutant ATXN1 S776 phosphorylation and aggregation, we designed a therapeutic polypeptide to inhibit PKA. This polypeptide comprised of a thermally responsive elastin-like peptide (ELP) carrier, which increases peptide half-life, a PKA inhibitory peptide (PKI), and a cell-penetrating peptide (Synb1). We observed that our therapeutic polypeptide, Synb1-ELP-PKI, inhibited PKA activity at concentrations similar to the PKI peptide. Additionally, Synb1-ELP-PKI significantly suppressed mutant ATXN1 S776 phosphorylation and intranuclear inclusion formation in cell culture. Further, Synb1-ELP-PKI treatment improved SCA1 PC morphology in cerebellar slice cultures. Furthermore, the Synb1-ELP peptide carrier crossed the blood-brain barrier and localized to the cerebellum via the i.p. or intranasal route. Here, we show the intranasal delivery of ELP-based peptides to the brain as a novel delivery strategy. We also demonstrate that our therapeutic polypeptide has a great potential to target the neurotoxic S776 phosphorylation pathway in the SCA1 disease. © 2014 International Society for Neurochemistry.

The construction of a public key infrastructure for healthcare information networks in Japan.

PubMed

Sakamoto, N

2001-01-01

The digital signature is a key technology in the forthcoming Internet society for electronic healthcare as well as for electronic commerce. Efficient exchanges of authorized information with a digital signature in healthcare information networks require a construction of a public key infrastructure (PKI). In order to introduce a PKI to healthcare information networks in Japan, we proposed a development of a user authentication system based on a PKI for user management, user authentication and privilege management of healthcare information systems. In this paper, we describe the design of the user authentication system and its implementation. The user authentication system provides a certification authority service and a privilege management service while it is comprised of a user authentication client and user authentication serves. It is designed on a basis of an X.509 PKI and is implemented with using OpenSSL and OpenLDAP. It was incorporated into the financial information management system for the national university hospitals and has been successfully working for about one year. The hospitals plan to use it as a user authentication method for their whole healthcare information systems. One implementation of the system is free to the national university hospitals with permission of the Japanese Ministry of Education, Culture, Sports, Science and Technology. Another implementation is open to the other healthcare institutes by support of the Medical Information System Development Center (MEDIS-DC). We are moving forward to a nation-wide construction of a PKI for healthcare information networks based on it.

The kinase inhibitors sunitinib and sorafenib differentially affect NK cell antitumor reactivity in vitro.

PubMed

Krusch, Matthias; Salih, Julia; Schlicke, Manuela; Baessler, Tina; Kampa, Kerstin Maria; Mayer, Frank; Salih, Helmut Rainer

2009-12-15

Sunitinib and Sorafenib are protein kinase inhibitors (PKI) approved for treatment of patients with advanced renal cell cancer (RCC). However, long-term remissions of advanced RCC have only been observed after IL-2 treatment, which underlines the importance of antitumor immune responses in RCC patients. Because PKI, besides affecting tumor cells, also may inhibit signaling in immune effector cells, we determined how Sunitinib and Sorafenib influence antitumor immunity. We found that cytotoxicity and cytokine production of resting and IL-2-activated PBMC are inhibited by pharmacological concentrations of Sorafenib but not Sunitinib. Analysis of granule-mobilization within PBMC revealed that this was due to impaired reactivity of NK cells, which substantially contribute to antitumor immunity by directly killing target cells and shaping adaptive immune responses by secreting cytokines like IFN-gamma. Analyses with resting and IL-2-activated NK cells revealed that both PKI concentration dependently inhibit cytotoxicity and IFN-gamma production of NK cells in response to tumor targets. This was due to impaired PI3K and ERK phosphorylation which directly controls NK cell reactivity. However, while Sorafenib inhibited NK cell effector functions and signaling at levels achieved upon recommended dosing, pharmacological concentrations of Sunitinib had no effect, and this was observed upon stimulation of NK cell reactivity by tumor target cells and upon IL-2 treatment. In light of the important role of NK cells in antitumor immunity, and because multiple approaches presently aim to combine PKI treatment with immunotherapeutic strategies, our data demonstrate that choice and dosing of the most suitable PKI in cancer treatment requires careful consideration.

Inner core boundary topography explored with reflected and diffracted P waves

NASA Astrophysics Data System (ADS)

deSilva, Susini; Cormier, Vernon F.; Zheng, Yingcai

2018-03-01

The existence of topography of the inner core boundary (ICB) can affect the amplitude, phase, and coda of body waves incident on the inner core. By applying pseudospectral and boundary element methods to synthesize compressional waves interacting with the ICB, these effects are predicted and compared with waveform observations in pre-critical, critical, post-critical, and diffraction ranges of the PKiKP wave reflected from the ICB. These data sample overlapping regions of the inner core beneath the circum-Pacific belt and the Eurasian, North American, and Australian continents, but exclude large areas beneath the Pacific and Indian Oceans and the poles. In the pre-critical range, PKiKP waveforms require an upper bound of 2 km at 1-20 km wavelength for any ICB topography. Higher topography sharply reduces PKiKP amplitude and produces time-extended coda not observed in PKiKP waveforms. The existence of topography of this scale smooths over minima and zeros in the pre-critical ICB reflection coefficient predicted from standard earth models. In the range surrounding critical incidence (108-130 °), this upper bound of topography does not strongly affect the amplitude and waveform behavior of PKIKP + PKiKP at 1.5 Hz, which is relatively insensitive to 10-20 km wavelength topography height approaching 5 km. These data, however, have a strong overlap in the regions of the ICB sampled by pre-critical PKiKP that require a 2 km upper bound to topography height. In the diffracted range (>152°), topography as high as 5 km attenuates the peak amplitudes of PKIKP and PKPCdiff by similar amounts, leaving the PKPCdiff/PKIKP amplitude ratio unchanged from that predicted by a smooth ICB. The observed decay of PKPCdiff into the inner core shadow and the PKIKP-PKPCdiff differential travel time are consistent with a flattening of the outer core P velocity gradient near the ICB and iron enrichment at the bottom of the outer core.

Podocyte hypertrophy precedes apoptosis under experimental diabetic conditions.

PubMed

Lee, Sun Ha; Moon, Sung Jin; Paeng, Jisun; Kang, Hye-Young; Nam, Bo Young; Kim, Seonghun; Kim, Chan Ho; Lee, Mi Jung; Oh, Hyung Jung; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Kang, Shin-Wook

2015-08-01

Podocyte hypertrophy and apoptosis are two hallmarks of diabetic glomeruli, but the sequence in which these processes occur remains a matter of debate. Here we investigated the effects of inhibiting hypertrophy on apoptosis, and vice versa, in both podocytes and glomeruli, under diabetic conditions. Hypertrophy and apoptosis were inhibited using an epidermal growth factor receptor inhibitor (PKI 166) and a pan-caspase inhibitor (zAsp-DCB), respectively. We observed significant increases in the protein expression of p27, p21, phospho-eukaryotic elongation factor 4E-binding protein 1, and phospho-p70 S6 ribosomal protein kinase, in both cultured podocytes exposed to high-glucose (HG) medium, and streptozotocin-induced diabetes mellitus (DM) rat glomeruli. These increases were significantly inhibited by PKI 166, but not by zAsp-DCB. In addition, the amount of protein per cell, the relative cell size, and the glomerular volume were all significantly increased under diabetic conditions, and these changes were also blocked by treatment with PKI 166, but not zAsp-DCB. Increased protein expression of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, together with increased Bax/Bcl-2 ratios, were also observed in HG-stimulated podocytes and DM glomeruli. Treatment with either zAsp-DCB or PKI 166 resulted in a significant attenuation of these effects. Both PKI 166 and zAsp-DCB also inhibited the increase in number of apoptotic cells, as assessed by Hoechst 33342 staining and TUNEL assay. Under diabetic conditions, inhibition of podocyte hypertrophy results in attenuated apoptosis, whereas blocking apoptosis has no effect on podocyte hypertrophy, suggesting that podocyte hypertrophy precedes apoptosis.

Information security system based on virtual-optics imaging methodology and public key infrastructure

NASA Astrophysics Data System (ADS)

Peng, Xiang; Zhang, Peng; Cai, Lilong

In this paper, we present a virtual-optical based information security system model with the aid of public-key-infrastructure (PKI) techniques. The proposed model employs a hybrid architecture in which our previously published encryption algorithm based on virtual-optics imaging methodology (VOIM) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). For an asymmetric system, given an encryption key, it is computationally infeasible to determine the decryption key and vice versa. The whole information security model is run under the framework of PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOIM security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network.

The PKI collector

NASA Astrophysics Data System (ADS)

Rice, M. P.

1982-07-01

The design and manufacturing of a solar thermal collector is discussed. The collector has three primary subsystems: concentrator, receiver/fluid loop, and controls. Identical curved reflective columns are utilized in a faceted Fresnel design to support 864 one foot square flat inexpensive second-surface, silvered glass mirrors. The columns are ganged together and rotated through their centers of gravity to provide elevation tracking. The concentrator is supported by a lightweight spaceframe structure which distributes all wind and gravity loads to the base supports. The base of the structure is a track which rotates on wheels mounted on concrete piers. A parallel tube steel heat exchanger is mounted at the concentrator focal area in a well insulated, galvanized steel housing. Two rows of vertical close-packed, staggered tubes connect a mud header and a steam header. Automatic two axis tracking and operational control is provided with a microprocessor based package. Concentrator-mounted shadowbands are the basis for active tracking. A software program provides azimuthal tracking during cloudy periods.

The PKI collector

NASA Technical Reports Server (NTRS)

Rice, M. P.

1982-01-01

The design and manufacturing of a solar thermal collector is discussed. The collector has three primary subsystems: concentrator, receiver/fluid loop, and controls. Identical curved reflective columns are utilized in a faceted Fresnel design to support 864 one foot square flat inexpensive second-surface, silvered glass mirrors. The columns are ganged together and rotated through their centers of gravity to provide elevation tracking. The concentrator is supported by a lightweight spaceframe structure which distributes all wind and gravity loads to the base supports. The base of the structure is a track which rotates on wheels mounted on concrete piers. A parallel tube steel heat exchanger is mounted at the concentrator focal area in a well insulated, galvanized steel housing. Two rows of vertical close-packed, staggered tubes connect a mud header and a steam header. Automatic two axis tracking and operational control is provided with a microprocessor based package. Concentrator-mounted shadowbands are the basis for active tracking. A software program provides azimuthal tracking during cloudy periods.

MEN16132, a novel potent and selective nonpeptide antagonist for the human bradykinin B2 receptor. In vitro pharmacology and molecular characterization.

PubMed

Cucchi, Paola; Meini, Stefania; Bressan, Alessandro; Catalani, Claudio; Bellucci, Francesca; Santicioli, Paolo; Lecci, Alessandro; Faiella, Angela; Rotondaro, Luigi; Giuliani, Sandro; Giolitti, Alessandro; Quartara, Laura; Maggi, Carlo Alberto

2005-12-28

The pharmacological characterization of the novel nonpeptide antagonist for the B2 receptor, namely MEN16132 (4-(S)-Amino-5-(4-{4-[2,4-dichloro-3-(2,4-dimethyl-8-quinolyloxymethyl)phenylsulfonamido]-tetrahydro-2H-4-pyranylcarbonyl}piperazino)-5-oxopentyl](trimethyl)ammonium chloride hydrochloride) is presented. The affinity of MEN16132 for the bradykinin B2 receptor has been investigated by means of competition studies at [3H]bradykinin binding to membranes prepared from Chinese Hamster Ovary (CHO) cells expressing the human bradykinin B2 receptor (pKi 10.5), human lung fibroblasts (pKi 10.5), guinea pig airways (pKi 10.0), guinea pig ileum longitudinal smooth muscle (pKi 10.2), or guinea pig cultured colonic myocytes (pKi 10.3). In all assays MEN16132 was as potent as the peptide antagonist Icatibant, and from 3- to 100-fold more potent than the reference nonpeptide antagonists FR173657 or LF16-0687. The selectivity for the bradykinin B2 receptor was checked at the human bradykinin B1 receptor (pKi<5), and at a panel of 26 different receptors and channels. The antagonist potency was measured in functional assays, i.e., in blocking the bradykinin induced inositolphosphates (IP) accumulation at the human (CHO: pKB 10.3) and guinea pig (colonic myocytes: pKB 10.3) B2 receptor, or in antagonizing the bradykinin induced contractile responses in human (detrusor smooth muscle: pKB 9.9) and guinea pig (ileum longitudinal smooth muscle: pKB 10.1) tissues. In both functional assay types MEN16132 exerted a different antagonist pattern, i.e., surmountable at the human and insurmountable at the guinea pig bradykinin B2 receptors. Moreover, the receptor determinants important for the high affinity interaction of MEN16132 with the human bradykinin B2 receptor were investigated by means of radioligand binding studies performed at 24 point-mutated receptors. The results obtained revealed that residues in transmembrane segment 2 (W86A), 3 (I110A), 6 (W256A), and 7 (Y295A, Y295F but

Virtual-optical information security system based on public key infrastructure

NASA Astrophysics Data System (ADS)

Peng, Xiang; Zhang, Peng; Cai, Lilong; Niu, Hanben

2005-01-01

A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.

Binding mechanism and dynamic conformational change of C subunit of PKA with different pathways

PubMed Central

Chu, Wen-Ting; Chu, Xiakun; Wang, Jin

2017-01-01

The catalytic subunit of PKA (PKAc) exhibits three major conformational states (open, intermediate, and closed) during the biocatalysis process. Both ATP and substrate/inhibitor can effectively induce the conformational changes of PKAc from open to closed states. Aiming to explore the mechanism of this allosteric regulation, we developed a coarse-grained model and analyzed the dynamics of conformational changes of PKAc during binding by performing molecular dynamics simulations for apo PKAc, binary PKAc (PKAc with ATP, PKAc with PKI), and ternary PKAc (PKAc with ATP and PKI). Our results suggest a mixed binding mechanism of induced fit and conformational selection, with the induced fit dominant. The ligands can drive the movements of Gly-rich loop as well as some regions distal to the active site in PKAc and stabilize them at complex state. In addition, there are two parallel pathways (pathway with PKAc-ATP as an intermediate and pathway PKAc-PKI as an intermediate) during the transition from open to closed states. By molecular dynamics simulations and rate constant analyses, we find that the pathway through PKAc-ATP intermediate is the main binding route from open to closed state because of the fact that the bound PKI will hamper ATP from successful binding and significantly increase the barrier for the second binding subprocess. These findings will provide fundamental insights of the mechanisms of PKAc conformational change upon binding. PMID:28855336

Binding mechanism and dynamic conformational change of C subunit of PKA with different pathways.

PubMed

Chu, Wen-Ting; Chu, Xiakun; Wang, Jin

2017-09-19

The catalytic subunit of PKA (PKAc) exhibits three major conformational states (open, intermediate, and closed) during the biocatalysis process. Both ATP and substrate/inhibitor can effectively induce the conformational changes of PKAc from open to closed states. Aiming to explore the mechanism of this allosteric regulation, we developed a coarse-grained model and analyzed the dynamics of conformational changes of PKAc during binding by performing molecular dynamics simulations for apo PKAc, binary PKAc (PKAc with ATP, PKAc with PKI), and ternary PKAc (PKAc with ATP and PKI). Our results suggest a mixed binding mechanism of induced fit and conformational selection, with the induced fit dominant. The ligands can drive the movements of Gly-rich loop as well as some regions distal to the active site in PKAc and stabilize them at complex state. In addition, there are two parallel pathways (pathway with PKAc-ATP as an intermediate and pathway PKAc-PKI as an intermediate) during the transition from open to closed states. By molecular dynamics simulations and rate constant analyses, we find that the pathway through PKAc-ATP intermediate is the main binding route from open to closed state because of the fact that the bound PKI will hamper ATP from successful binding and significantly increase the barrier for the second binding subprocess. These findings will provide fundamental insights of the mechanisms of PKAc conformational change upon binding.

Assumptions, Trust, and Names in Computer Security Protocols

DTIC Science & Technology

2011-06-01

sharing her banking credentials with a criminal, which is clearly bad . But PKI proto- cols like this one can be used in other, less risky ways. Suppose...Figure 4.5. This is similar to a failure of PKI-based protocols in which the authority signs a bad certificate. But the interesting thing is how the... Zoo Figure 4.6: Using AdultVerify. The run is as follows: 1. As the first step in Diffie-Hellman Key Exchange, Alice picks and sends the

A Proposal of TLS Implementation for Cross Certification Model

NASA Astrophysics Data System (ADS)

Kaji, Tadashi; Fujishiro, Takahiro; Tezuka, Satoru

Today, TLS is widely used for achieving a secure communication system. And TLS is used PKI for server authentication and/or client authentication. However, its PKI environment, which is called as “multiple trust anchors environment,” causes the problem that the verifier has to maintain huge number of CA certificates in the ubiquitous network because the increase of terminals connected to the network brings the increase of CAs. However, most of terminals in the ubiquitous network will not have enough memory to hold such huge number of CA certificates. Therefore, another PKI environment, “cross certification environment”, is useful for the ubiquitous network. But, because current TLS is designed for the multiple trust anchors model, TLS cannot work efficiently on the cross-certification model. This paper proposes a TLS implementation method to support the cross certification model efficiently. Our proposal reduces the size of exchanged messages between the TLS client and the TLS server during the handshake process. Therefore, our proposal is suitable for implementing TLS in the terminals that do not have enough computing power and memory in ubiquitous network.

Argyreia nervosa (Burm. f.): receptor profiling of lysergic acid amide and other potential psychedelic LSD-like compounds by computational and binding assay approaches.

PubMed

Paulke, Alexander; Kremer, Christian; Wunder, Cora; Achenbach, Janosch; Djahanschiri, Bardya; Elias, Anderson; Schwed, J Stefan; Hübner, Harald; Gmeiner, Peter; Proschak, Ewgenij; Toennes, Stefan W; Stark, Holger

2013-07-09

The convolvulacea Argyreia nervosa (Burm. f.) is well known as an important medical plant in the traditional Ayurvedic system of medicine and it is used in numerous diseases (e.g. nervousness, bronchitis, tuberculosis, arthritis, and diabetes). Additionally, in the Indian state of Assam and in other regions Argyreia nervosa is part of the traditional tribal medicine (e.g. the Santali people, the Lodhas, and others). In the western hemisphere, Argyreia nervosa has been brought in attention as so called "legal high". In this context, the seeds are used as source of the psychoactive ergotalkaloid lysergic acid amide (LSA), which is considered as the main active ingredient. As the chemical structure of LSA is very similar to that of lysergic acid diethylamide (LSD), the seeds of Argyreia nervosa (Burm. f.) are often considered as natural substitute of LSD. In the present study, LSA and LSD have been compared concerning their potential pharmacological profiles based on the receptor binding affinities since our recent human study with four volunteers on p.o. application of Argyreia nervosa seeds has led to some ambiguous effects. In an initial step computer-aided in silico prediction models on receptor binding were employed to screen for serotonin, norepinephrine, dopamine, muscarine, and histamine receptor subtypes as potential targets for LSA. In addition, this screening was extended to accompany ergotalkaloids of Argyreia nervosa (Burm. f.). In a verification step, selected LSA screening results were confirmed by in vitro binding assays with some extensions to LSD. In the in silico model LSA exhibited the highest affinity with a pKi of about 8.0 at α1A, and α1B. Clear affinity with pKi>7 was predicted for 5-HT1A, 5-HT1B, 5-HT1D, 5-HT6, 5-HT7, and D2. From these receptors the 5-HT1D subtype exhibited the highest pKi with 7.98 in the prediction model. From the other ergotalkaloids, agroclavine and festuclavine also seemed to be highly affine to the 5-HT1D

Activation of G protein-coupled estrogen receptor 1 induces coronary artery relaxation via Epac/Rap1-mediated inhibition of RhoA/Rho kinase pathway in parallel with PKA.

PubMed

Yu, Xuan; Zhang, Qiao; Zhao, Yan; Schwarz, Benjamin J; Stallone, John N; Heaps, Cristine L; Han, Guichun

2017-01-01

Previously, we reported that cAMP/PKA signaling is involved in GPER-mediated coronary relaxation by activating MLCP via inhibition of RhoA pathway. In the current study, we tested the hypothesis that activation of GPER induces coronary artery relaxation via inhibition of RhoA/Rho kinase pathway by cAMP downstream targets, exchange proteins directly activated by cAMP (Epac) as well as PKA. Our results show that Epac inhibitors, brefeldin A (BFA, 50 μM), or ESI-09 (20 μM), or CE3F4 (100 μM), all partially inhibited porcine coronary artery relaxation response to the selective GPER agonist, G-1 (0.3-3 μM); while concurrent administration of BFA and PKI (5 μM), a PKA inhibitor, almost completely blocked the relaxation effect of G-1. The Epac specific agonist, 8-CPT-2Me-cAMP (007, 1-100 μM), induced a concentration-dependent relaxation response. Furthermore, the activity of Ras-related protein 1 (Rap1) was up regulated by G-1 (1 μM) treatment of porcine coronary artery smooth muscle cells (CASMCs). Phosphorylation of vasodilator-stimulated phosphoprotein (p-VASP) was elevated by G-1 (1 μM) treatment, but not by 007 (50 μM); and the effect of G-1 on p-VASP was blocked by PKI, but not by ESI-09, an Epac antagonist. RhoA activity was similarly down regulated by G-1 and 007, whereas ESI-09 restored most of the reduced RhoA activity by G-1 treatment. Furthermore, G-1 decreased PGF2α-induced p-MYPT1, which was partially reversed with either ESI-09 or PKI; whereas, concurrent administration of ESI-09 and PKI totally prevented the inhibitory effect of G-1. The inhibitory effects of G-1 on p- MLC levels in CASMCs were mostly restored by either ESI-09 or PKI. These results demonstrate that activation of GPER induces coronary artery relaxation via concurrent inhibition of RhoA/Rho kinase by Epac/Rap1 and PKA. GPER could be a potential drug target for preventing and treating cardiovascular diseases.

Seismic velocity and attenuation structures at the top 400 km of the inner core

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.; Niu, F.

2002-12-01

Recent seismic studies reveal an ``east-west" hemispherical difference in seismic velocity and attenuation in the top of the inner core [Niu and Wen, 2001, Wen and Niu, 2002]. The PKiKP-PKIKP observations they used only allowed them to constrain the seismic structure in the top 80 km of the inner core. The question now arises as such to what depth this hemispherical difference persists. To answer this question, we combine the PKiKP-PKIKP dataset and the PKPbc-PKIKP observations at the distance range of 147o-160o to study seismic velocity and attenuation structures in the top 400 km of the inner core along the ``equatorial paths" (the paths whose ray angles > 35o from the polar direction). We select PKPbc-PKIKP waveforms from recordings in the Global Seismic Network (GSN) and several dense regional seismic arrays. We choose recordings for events from 1990 to 2000 with simple source time functions, so only those of intermediate and deep earthquakes are used. The observed PKPbc-PKIKP differential travel times and PKIKP/PKPbc amplitude ratios exhibit an ``east-west" hemispherical difference. The PKPbc-PKIKP travel time residuals are about 0.7 second larger for those sampling the ``eastern" hemisphere than those sampling the ``western" hemisphere. The PKIKP/PKPbc amplitude ratios are generally smaller for those sampling the ``eastern" hemisphere. We construct two seismic velocity and attenuation models, with one for each ``hemisphere", by iteratively modeling the observed PKiKP-PKIKP waveforms, the PKPbc-PKIKP differential travel times and the PKIKP/PKPbc amplitude ratios. For the ``eastern" hemisphere, the observations indicate that the E1 velocity gradient and Q structure, inferred from the PKiKP-PKIKP observations sampling the top 80 km of the inner core, extend at least to 230 km inside the inner core. A change of velocity gradient and Q value is required in the deeper portion of the inner core. For the ``western" hemisphere, on the other hand, W2 velocity gradient

Temporal changes of the inner core from waveform doublets

NASA Astrophysics Data System (ADS)

Yang, Y.; Song, X.

2017-12-01

Temporal changes of the Earth's inner core have been detected from earthquake waveform doublets (repeating sources with similar waveforms at the same station). Using doublets from events up to the present in the South Sandwich Island (SSI) region recorded by the station COLA (Alaska), we confirmed systematic temporal variations in the travel time of the inner-core-refracted phase (PKIKP, the DF branch). The DF phase arrives increasingly earlier than outer core phases (BC and AB) by rate of approximately 0.07 s per decade since 1970s. If we assume that the temporal change is caused by a shift of the lateral gradient from the inner core rotation as in previous studies, we estimate the rotation rate of 0.2-0.4 degree per year. We also analyzed the topography of the inner core boundary (ICB) using SSI waveform doublets recorded by seismic stations in Eurasia and North America with reflected phase (PKiKP) and refracted phases. There are clear temporal changes in the waveforms of doublets for PKiKP under Africa and Central America. In addition, for doublets recorded by three nearby stations (AAK, AML, and UCH), we observed systematic change in the relative travel time of PKiKP and PKIKP. The temporal change of the (PKiKP - PKIKP) differential time is always negative for the event pairs if both events are before 2007, while it fluctuates to positive if the later event occurs after 2007. The rapid temporal changes in space and time may indicate localized processes (e.g., freezing and melting) of the ICB in the recent decades under Africa. We are exploring 4D models consistent with the temporal changes.

Ki-67 as a molecular target for therapy in an in vitro three-dimensional model for ovarian cancer.

PubMed

Rahmanzadeh, Ramtin; Rai, Prakash; Celli, Jonathan P; Rizvi, Imran; Baron-Lühr, Bettina; Gerdes, Johannes; Hasan, Tayyaba

2010-11-15

Targeting molecular markers and pathways implicated in cancer cell growth is a promising avenue for developing effective therapies. Although the Ki-67 protein (pKi-67) is a key marker associated with aggressively proliferating cancer cells and poor prognosis, its full potential as a therapeutic target has never before been successfully shown. In this regard, its nuclear localization presents a major hurdle because of the need for intracellular and intranuclear delivery of targeting and therapeutic moieties. Using a liposomally encapsulated construct, we show for the first time the specific delivery of a Ki-67-directed antibody and subsequent light-triggered death in the human ovarian cancer cell line OVCAR-5. Photoimmunoconjugate-encapsulating liposomes (PICEL) were constructed from anti-pKi-67 antibodies conjugated to fluorescein 5(6)-isothiocyanate, as a photoactivatable agent, followed by encapsulation in noncationic liposomes. Nucleolar localization of the PICELs was confirmed by confocal imaging. Photodynamic activation with PICELs specifically killed pKi-67-positive cancer cells both in monolayer and in three-dimensional (3D) cultures of OVCAR-5 cells, with the antibody TuBB-9 targeting a physiologically active form of pKi-67 but not with MIB-1, directed to a different epitope. This is the first demonstration of (a) the exploitation of Ki-67 as a molecular target for therapy and (b) specific delivery of an antibody to the nucleolus in monolayer cancer cells and in an in vitro 3D model system. In view of the ubiquity of pKi-67 in proliferating cells in cancer and the specificity of targeting in 3D multicellular acini, these findings are promising and the approach merits further investigation. Copyright © 2010 AACR.

Ki-67 as a molecular target for therapy in an in vitro 3D model for ovarian cancer

PubMed Central

Rahmanzadeh, Ramtin; Rai, Prakash; Celli, Jonathan P.; Rizvi, Imran; Baron-Lühr, Bettina; Gerdes, Johannes; Hasan, Tayyaba

2010-01-01

Targeting molecular markers and pathways implicated in cancer cell growth is a promising avenue for developing effective therapies. Although the Ki-67 protein (pKi-67) is a key marker associated with aggressively proliferating cancer cells and poor prognosis, its full potential as a therapeutic target has never before been successfully demonstrated. In this regard, its nuclear localization presents a major hurdle because of the need for intracellular and intranuclear delivery of targeting and therapeutic moieties. Using a liposomally encapsulated construct, we demonstrate for the first time, the specific delivery of a Ki-67 directed antibody and subsequent light-triggered death in a human ovarian cancer cell line OVCAR-5. Photoimmunoconjugate encapsulating liposomes (PICELs) were constructed from anti-pKi-67 antibodies conjugated to fluorescein isothiocyanate, as a photoactivatable agent followed by encapsulation in non-cationic liposomes. Nucleolar localization of the PICELs was confirmed by confocal imaging. Photodynamic activation with PICELs specifically killed pKi-67 positive cancer cells both in monolayer and in 3D cultures of OVCAR-5 cells with the antibody TuBB-9 targeting a physiologically active form of pKi-67 but not with MIB-1, directed to a different epitope. This is the first demonstration of: - 1. the exploitation of Ki-67 as a molecular target for therapy and - 2. specific delivery of an antibody to the nucleolus in monolayer cancer cells and in an in vitro 3D model system. In view of the ubiquity of pKi-67 in proliferating cells in cancer and the specificity of targeting in 3D multicellular acini, these findings are promising and the approach merits further investigation. PMID:21045152

A Global Study of Inner Core Boundary Topography and its Temporal Variations

NASA Astrophysics Data System (ADS)

Ibourichene, A.; Romanowicz, B. A.

2015-12-01

The inner core boundary (ICB) separates the solid inner core from the surrounding liquid outer core. Its detailed properties, such as its shape, the density jump across it or its topography are key for understanding the dynamics of the core and, ultimately, the generation and sustained character of the Earth's magnetic field. The determination of the ICB topography and its variation with time could also enhance our understanding of the inner core growth and its past history.Seismology makes use of two phases to study the shallow inner core : the PKiKP, reflected at the ICB and the PKIKP, refracted into the inner core. The PKiKP/PKIKP amplitude ratio and the travel time residual of these phases characterize the vicinity of the ICB and may help constrain ICB topography. Different studies propose various wavelengths for this topography: from hundreds of meters to tens of kilometers. Several parameters can affect PKiKP/PKIKP amplitude ratios and the corresponding differential travel time, such as the quality factor of the shallow inner core, the density jump at the ICB, the geometry of the ray paths or even the reflection coefficient at the ICB. We present a global map of PKiKP/PKIKP amplitude ratios and differential travel times filtered in different pass-bands, with regional densification based, in particular, on the relatively short wavelength sampling afforded by large aperture broadband arrays, such as USArray, and discuss their spatial variability and interpretation in terms of ICB topography, as appropriate.We also have assembled a catalog of high quality doublets which provide a reference for the stability of the measurements, and point to possible time variability of the topography.

Evaluation of security algorithms used for security processing on DICOM images

NASA Astrophysics Data System (ADS)

Chen, Xiaomeng; Shuai, Jie; Zhang, Jianguo; Huang, H. K.

2005-04-01

In this paper, we developed security approach to provide security measures and features in PACS image acquisition and Tele-radiology image transmission. The security processing on medical images was based on public key infrastructure (PKI) and including digital signature and data encryption to achieve the security features of confidentiality, privacy, authenticity, integrity, and non-repudiation. There are many algorithms which can be used in PKI for data encryption and digital signature. In this research, we select several algorithms to perform security processing on different DICOM images in PACS environment, evaluate the security processing performance of these algorithms, and find the relationship between performance with image types, sizes and the implementation methods.

Activation of G protein-coupled bile acid receptor, TGR5, induces smooth muscle relaxation via both Epac- and PKA-mediated inhibition of RhoA/Rho kinase pathway.

PubMed

Rajagopal, Senthilkumar; Kumar, Divya P; Mahavadi, Sunila; Bhattacharya, Sayak; Zhou, Ruizhe; Corvera, Carlos U; Bunnett, Nigel W; Grider, John R; Murthy, Karnam S

2013-03-01

The present study characterized the TGR5 expression and the signaling pathways coupled to this receptor that mediates the relaxation of gastric smooth muscle. TGR5 was detected in gastric muscle cells by RT-PCR and Western blotting. Treatment of cells with the TGR5-selective ligand oleanolic acid (OA) activated Gαs, but not Gαq, Gαi1, Gαi2, or Gαi3, and increased cAMP levels. OA did not elicit contraction, but caused relaxation of carbachol-induced contraction of gastric muscle cells from wild-type mice, but not tgr5(-/-) mice. OA, but not a selective exchange protein activated by cAMP (Epac) ligand (8-pCPT-2'-O-Me-cAMP), caused phosphorylation of RhoA and the phosphorylation was blocked by the PKA inhibitor, myristoylated PKI, and by the expression of phosphorylation-deficient mutant RhoA (S188A). Both OA and Epac ligand stimulated Ras-related protein 1 (Rap1) and inhibited carbachol (CCh)-induced Rho kinase activity. Expression of RhoA (S188A) or PKI partly reversed the inhibition of Rho kinase activity by OA but had no effect on inhibition by Epac ligand. However, suppression of Rap1 with siRNA blocked the inhibition of Rho kinase by Epac ligand, and partly reversed the inhibition by OA; the residual inhibition was blocked by PKI. Muscle relaxation in response to OA, but not Epac ligand, was partly reversed by PKI. We conclude that activation of TGR5 causes relaxation of gastric smooth muscle and the relaxation is mediated through inhibition of RhoA/Rho kinase pathway via both cAMP/Epac-dependent stimulation of Rap1 and cAMP/PKA-dependent phosphorylation of RhoA at Ser(188). TGR5 receptor activation on smooth muscle reveals a novel mechanism for the regulation of gut motility by bile acids.

The Security Email Based on Smart Card

NASA Astrophysics Data System (ADS)

Lina, Zhang; Jiang, Meng Hai.

Email has become one of the most important communication tools in modern internet society, and its security is an important issue that can't be ignored. The security requirements of Email can be summarized as confidentiality, integrity, authentication and non-repudiation. Recently many researches on IBE (identify based encrypt) have been carried out to solve these security problems. However, because of IBE's fatal flaws and great advantages of PKI (Public Key Infrastructure), PKI is found to be still irreplaceable especially in the applications based on smart card. In this paper, a construction of security Email is presented, then the design of relatively cryptography algorithms and the configuration of certificates are elaborated, and finally the security for the proposed system is discussed.

Evidence of the immunomodulatory role of dual PI3K/mTOR inhibitors in transplantation: an experimental study in mice.

PubMed

Vilchez, Valery; Turcios, Lilia; Butterfield, David A; Mitov, Mihail I; Coquillard, Cristin L; Brandon, Ja Anthony; Cornea, Virgilius; Gedaly, Roberto; Marti, Francesc

2017-10-01

The PI3K/mTOR signaling cascade is fundamental in T-cell activation and fate decisions. We showed the distinct regulation of PI3K/mTOR in regulatory and effector T-cells and proposed the potential therapeutic benefit of targeting this pathway to control the balance between effector and regulatory T-cell activities. Substantial adverse effects in long-term clinical usage of rapamycin suggest the use of alternative treatments in restraining effector T-cell function in transplant patients. We hypothesize that dual PI3K/mTOR inhibitors may represent an immunosuppressant alternative. Here we show that dual PI3K/mTOR PI-103 and PKI-587 inhibitors interfered IL-2-dependent responses in T-cells. However, in contrast to the inhibitory effects in non-Treg T-cell proliferation and effector functions, dual inhibitors increased the differentiation, preferential expansion, and suppressor activity of iTregs. Rapamycin, PI-103, and PKI-587 targeted different signaling events and induced different metabolic patterns in primary T-cells. Similar to rapamycin, in vivo administration of PI-103 and PKI-587 controlled effectively the immunological response against allogeneic skin graft. These results characterize specific regulatory mechanisms of dual PI3K/mTOR inhibitors in T-cells and support their potential as a novel therapeutic option in transplantation. © 2017 Steunstichting ESOT.

75 FR 81249 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-27

...: By name, Social Security Number (SSN), and/or date of birth. Safeguards: System login is accomplished by DoD Common Access Card (CAC). Public Key Infrastructure (PKI) network login is required and allows...

Imaging the local crustal structure of the European Eastern Alps through teleseismic reflections from the Earth's inner core recorded during an active source experiment

NASA Astrophysics Data System (ADS)

Behm, M.

2016-12-01

The ALP2002 experiment was a large 3D active seismic experiment to reveal the crustal structure of the Eastern Alps and their neighboring tectonic provinces in Central Europe. The deployment comprised 993 autonomous Reftek Texan recorders equipped with vertical component geophones. The average station spacing was 4.5 km, and the recording instruments were distributed along 14 interlocking profiles with a total line length of 4313 km. During 5 days, 40 explosions in boreholes were fired and recorded within pre-programmed time windows. The limited memory capacity of the recorders allowed for just a few additional backup time windows. Despite the short total recording time of only 17.5 hours within 5 days, one of these backup time windows comprises the registration of the reflection from the earth's inner core (PKiKP phase) originating from an earthquake 130 km offshore Papa New Guinea. This magnitude 5.7 teleseimic event occurred in a depth of 33 km and its epicentral distance to the deployment area is 121.5°. Although the 1C geophones with a natural frequency of 4.5 Hz are not designed to capture the complete characteristics of low-frequency earthquake waveforms, the high-frequency part of the PKiKP wavelet is clearly recorded on all 993 stations. Thus the dataset represents a unique opportunity to study regional and local crustal structures from the analysis of teleseismic events, in particular since the results from the active source data provide calibration and validation. Arrival time analysis is facilitated by the sub-vertical emergence angle of the PKiKP phase. Time corrections for the near surface (< 10 km depth) and the upper mantle structure (50 - 400 km depth) are obtained from previously established seismic 3D models and allow focusing the interpretation on the lower crust and crust-mantle transition. Further, a recently developed blind deconvolution approach is applied to the data for imaging the crustal structure from surface reflections of the PKi

Activation of G protein-coupled bile acid receptor, TGR5, induces smooth muscle relaxation via both Epac- and PKA-mediated inhibition of RhoA/Rho kinase pathway

PubMed Central

Rajagopal, Senthilkumar; Kumar, Divya P.; Mahavadi, Sunila; Bhattacharya, Sayak; Zhou, Ruizhe; Corvera, Carlos U.; Bunnett, Nigel W.; Grider, John R.

2013-01-01

The present study characterized the TGR5 expression and the signaling pathways coupled to this receptor that mediates the relaxation of gastric smooth muscle. TGR5 was detected in gastric muscle cells by RT-PCR and Western blotting. Treatment of cells with the TGR5-selective ligand oleanolic acid (OA) activated Gαs, but not Gαq, Gαi1, Gαi2, or Gαi3, and increased cAMP levels. OA did not elicit contraction, but caused relaxation of carbachol-induced contraction of gastric muscle cells from wild-type mice, but not tgr5−/− mice. OA, but not a selective exchange protein activated by cAMP (Epac) ligand (8-pCPT-2′-O-Me-cAMP), caused phosphorylation of RhoA and the phosphorylation was blocked by the PKA inhibitor, myristoylated PKI, and by the expression of phosphorylation-deficient mutant RhoA (S188A). Both OA and Epac ligand stimulated Ras-related protein 1 (Rap1) and inhibited carbachol (CCh)-induced Rho kinase activity. Expression of RhoA (S188A) or PKI partly reversed the inhibition of Rho kinase activity by OA but had no effect on inhibition by Epac ligand. However, suppression of Rap1 with siRNA blocked the inhibition of Rho kinase by Epac ligand, and partly reversed the inhibition by OA; the residual inhibition was blocked by PKI. Muscle relaxation in response to OA, but not Epac ligand, was partly reversed by PKI. We conclude that activation of TGR5 causes relaxation of gastric smooth muscle and the relaxation is mediated through inhibition of RhoA/Rho kinase pathway via both cAMP/Epac-dependent stimulation of Rap1 and cAMP/PKA-dependent phosphorylation of RhoA at Ser188. TGR5 receptor activation on smooth muscle reveals a novel mechanism for the regulation of gut motility by bile acids. PMID:23275618

Temporal Change of Seismic Earth's Inner Core Phases: Inner Core Differential Rotation Or Temporal Change of Inner Core Surface?

NASA Astrophysics Data System (ADS)

Yao, J.; Tian, D.; Sun, L.; Wen, L.

2017-12-01

Since Song and Richards [1996] first reported seismic evidence for temporal change of PKIKP wave (a compressional wave refracted in the inner core) and proposed inner core differential rotation as its explanation, it has generated enormous interests in the scientific community and the public, and has motivated many studies on the implications of the inner core differential rotation. However, since Wen [2006] reported seismic evidence for temporal change of PKiKP wave (a compressional wave reflected from the inner core boundary) that requires temporal change of inner core surface, both interpretations for the temporal change of inner core phases have existed, i.e., inner core rotation and temporal change of inner core surface. In this study, we discuss the issue of the interpretation of the observed temporal changes of those inner core phases and conclude that inner core differential rotation is not only not required but also in contradiction with three lines of seismic evidence from global repeating earthquakes. Firstly, inner core differential rotation provides an implausible explanation for a disappearing inner core scatterer between a doublet in South Sandwich Islands (SSI), which is located to be beneath northern Brazil based on PKIKP and PKiKP coda waves of the earlier event of the doublet. Secondly, temporal change of PKIKP and its coda waves among a cluster in SSI is inconsistent with the interpretation of inner core differential rotation, with one set of the data requiring inner core rotation and the other requiring non-rotation. Thirdly, it's not reasonable to invoke inner core differential rotation to explain travel time change of PKiKP waves in a very small time scale (several months), which is observed for repeating earthquakes in Middle America subduction zone. On the other hand, temporal change of inner core surface could provide a consistent explanation for all the observed temporal changes of PKIKP and PKiKP and their coda waves. We conclude that

Audited credential delegation: a usable security solution for the virtual physiological human toolkit.

PubMed

Haidar, Ali N; Zasada, Stefan J; Coveney, Peter V; Abdallah, Ali E; Beckles, Bruce; Jones, Mike A S

2011-06-06

We present applications of audited credential delegation (ACD), a usable security solution for authentication, authorization and auditing in distributed virtual physiological human (VPH) project environments that removes the use of digital certificates from end-users' experience. Current security solutions are based on public key infrastructure (PKI). While PKI offers strong security for VPH projects, it suffers from serious usability shortcomings in terms of end-user acquisition and management of credentials which deter scientists from exploiting distributed VPH environments. By contrast, ACD supports the use of local credentials. Currently, a local ACD username-password combination can be used to access grid-based resources while Shibboleth support is underway. Moreover, ACD provides seamless and secure access to shared patient data, tools and infrastructure, thus supporting the provision of personalized medicine for patients, scientists and clinicians participating in e-health projects from a local to the widest international scale.

Basis for the implementation of digital signature in Argentine's health environment

NASA Astrophysics Data System (ADS)

Escobar, P. P.; Formica, M.

2007-11-01

The growth of telemedical applications and electronic transactions in health environments is paced by the constant technology evolution. This implies a big cultural change in traditional medicine and in hospital information systems' users which arrival is delayed, basically, by the lack of solid laws and a well defined role-based infrastructure. The use of digital signature as a mean of identification, authentication, confidentiality and non-repudiation is the most suitable tool for assuring the electronic transactions and patient's data protection. The implementation of a Public Key Infrastructure (PKI) in health environment allows for authentication, encryption and use of digital signature for assuring confidentiality and control of the movement of sensitive information. This work defines the minimum technological, legal and procedural basis for a successful PKI implementation and establishes the roles for the different actors in the chain of confidence in the public health environment of Argentine.

Audited credential delegation: a usable security solution for the virtual physiological human toolkit

PubMed Central

Haidar, Ali N.; Zasada, Stefan J.; Coveney, Peter V.; Abdallah, Ali E.; Beckles, Bruce; Jones, Mike A. S.

2011-01-01

We present applications of audited credential delegation (ACD), a usable security solution for authentication, authorization and auditing in distributed virtual physiological human (VPH) project environments that removes the use of digital certificates from end-users' experience. Current security solutions are based on public key infrastructure (PKI). While PKI offers strong security for VPH projects, it suffers from serious usability shortcomings in terms of end-user acquisition and management of credentials which deter scientists from exploiting distributed VPH environments. By contrast, ACD supports the use of local credentials. Currently, a local ACD username–password combination can be used to access grid-based resources while Shibboleth support is underway. Moreover, ACD provides seamless and secure access to shared patient data, tools and infrastructure, thus supporting the provision of personalized medicine for patients, scientists and clinicians participating in e-health projects from a local to the widest international scale. PMID:22670214

Forskolin increases angiogenesis through the coordinated cross-talk of PKA-dependent VEGF expression and Epac-mediated PI3K/Akt/eNOS signaling.

PubMed

Namkoong, Seung; Kim, Chun-Ki; Cho, Young-Lai; Kim, Ji-Hee; Lee, Hansoo; Ha, Kwon-Soo; Choe, Jongseon; Kim, Pyeung-Hyeun; Won, Moo-Ho; Kwon, Young-Geun; Shim, Eun Bo; Kim, Young-Myeong

2009-06-01

Forskolin, a potent activator of adenylyl cyclases, has been implicated in modulating angiogenesis, but the underlying mechanism has not been clearly elucidated. We investigated the signal mechanism by which forskolin regulates angiogenesis. Forskolin stimulated angiogenesis of human endothelial cells and in vivo neovascularization, which was accompanied by phosphorylation of CREB, ERK, Akt, and endothelial nitric oxide synthase (eNOS) as well as NO production and VEGF expression. Forskolin-induced CREB phosphorylation, VEGF promoter activity, and VEGF expression were blocked by the PKA inhibitor PKI.Moreover, phosphorylation of ERK by forskolin was inhibited by the MEK inhibitor PD98059, but not PKI. The forskolin-induced Akt/eNOS/NO pathway was completely inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, but not significantly suppressed by PKI. These inhibitors and a NOS inhibitor partially inhibited forskolin-induced angiogenesis. The exchange protein directly activated by cAMP (Epac) activator, 8CPT-2Me-cAMP, promoted the Akt/eNOS/NO pathway and ERK phosphorylation,but did not induce CREB phosphorylation and VEGF expression. The angiogenic effect of the Epac activator was diminished by the inhibition of PI3K and MEK, but not by the PKA inhibitor. Small interfering RNA-mediated knockdown of Epac1 suppressed forskolin-induced angiogenesis and phosphorylation of ERK, Akt, and eNOS, but not CREB phosphorylation and VEGF expression. These results suggest that forskolin stimulates angiogenesis through coordinated cross-talk between two distinct pathways, PKA-dependent VEGF expression and Epac-dependent ERKactivation and PI3K/Akt/eNOS/NO signaling.

HIV-1-associated PKA acts as a cofactor for genome reverse transcription

PubMed Central

2013-01-01

Background Host cell proteins, including cellular kinases, are embarked into intact HIV-1 particles. We have previously shown that the Cα catalytic subunit of cAMP-dependent protein kinase is packaged within HIV-1 virions as an enzymatically active form able to phosphorylate a synthetic substrate in vitro (Cartier et al. J. Biol. Chem. 278:35211 (2003)). The present study was conceived to investigate the contribution of HIV-1-associated PKA to the retroviral life cycle. Results NL4.3 viruses were produced from cells cultured in the presence of PKA inhibitors H89 (H89-NL4.3) or Myr-PKI (PKI-NL4.3) and analyzed for viral replication. Despite being mature and normally assembled, and containing expected levels of genomic RNA and RT enzymatic activity, such viruses showed poor infectivity. Indeed, infection generated reduced amounts of strong-strop minus strand DNA, while incoming RNA levels in target cells were unaffected. Decreased cDNA synthesis was also evidenced in intact H89-NL4.3 and PKI-NL4.3 cell free particles using endogenous reverse transcription (ERT) experiments. Moreover, similar defects were reproduced when wild type NL4.3 particles preincubated with PKA inhibitors were subjected to ERT reactions. Conclusions Altogether, our results indicate that HIV-1-associated PKA is required for early reverse transcription of the retroviral genome both in cell free intact viruses and in target cells. Accordingly, virus-associated PKA behaves as a cofactor of an intraviral process required for optimal reverse transcription and for early post-entry events. PMID:24344931

Public Key Infrastructure Study

DTIC Science & Technology

1994-04-01

commerce. This Public Key Infrastructure (PKI) study focuses on the United States Federal Government operations, but also addresses national and global ... issues in order to facilitate the interoperation of protected electronic commerce among the various levels of government in the U.S., private citizens

Myristoylated peptides potentiate the funny current (If) in sinoatrial myocytes

PubMed Central

Liao, Zhandi; St Clair, Joshua R; Larson, Eric D

2011-01-01

The funny current, If, in sinoatrial myocytes is thought to contribute to the sympathetic fight-or-flight increase in heart rate. If is produced by hyperpolarization-activated cyclic nucleotide sensitive-4 (HCN4) channels, and it is widely believed that sympathetic regulation of If occurs via direct binding of cAMP to HCN4, independent of phosphorylation. However, we have recently shown that Protein Kinase A (PKA) activity is required for sympathetic regulation of If, and that PKA can directly phosphorylate HCN4.1 In the present study, we examined the effects of a myristoylated PKA inhibitory peptide (myr-PKI) on If in mouse sinoatrial myocytes. We found that myr-PKI and another myristoylated peptide potently and specifically potentiated If via a mechanism that did not involve PKA inhibition and that was independent of the peptide sequence, Protein Kinase C or phosphatidylinositol-4,5-bisphosphate. The off-target activation of If by myristoylated peptides limits their usefulness for studies of pacemaker mechanisms in sinoatrial myocytes. PMID:21150293

K-Anonymous Multi-party Secret Handshakes

NASA Astrophysics Data System (ADS)

Xu, Shouhuai; Yung, Moti

Anonymity-protection techniques are crucial for various commercial and financial transactions, where participants are worried about their privacy. On the other hand, authentication methods are also crucial for such interactions. Secret handshake is a relatively recent mechanism that facilitates privacy-preserving mutual authentication between communicating peers. In recent years, researchers have proposed a set of secret handshake schemes based on different assumptions about the credentials used: from one-time credentials to the more general PKI-like credentials. In this paper, we concentrate on k-anonymous secret handshake schemes based on PKI-like infrastructures. More specifically, we deal with the k-anonymous m-party (m > 2) secret handshake problem, which is significantly more involved than its two-party counterpart due to the following: When an honest user hand-shakes with m - 1 parties, it must be assured that these parties are distinct; otherwise, under the mask of anonymity a dishonest participant may clone itself in a single handshake session (i.e., assuming multiple personalities).

Seismic structures in the inner and outer core constrained by the PKP observations near the caustic distance range

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.; Niu, F.

2002-05-01

We have extensively collected PKP waveforms around the PKP caustic distance range (141o - 147o) recorded in several dense regional arrays and the Global Seismic Network covering from 1990 to 2000. PKP observations at this distance range (141o - 147o) are usually purposely avoided in travel time analyses, because of the interference of various PKP branches. The observations there, however, will be extremely useful for constraining the seismic structures at both the top of the inner core and the bottom of the outer core. Moreover, because PKIKP phases sample a depth range of 100 km - 170 km below the inner-core boundary at this distant range, their observations fill the sampling depth gap between the PKiKP-PKIKP observations at the smaller distances and the PKPbc-PKIKP phases at the larger distances. Before the PKP caustics (141o - 145o), the diffracted PKP phases near the B caustics (PKPBdiff) and PKiKP phases are discernible in the long-period seismograms, and their differential travel times and waveforms could be used to constrain seismic structures at the bottom of the outer core and/or at the base of the mantle. The observed long-period PKiKP-PKPBdiff waveforms exhibit a hemispheric difference between those sampling the "eastern" and "western" hemispheres, with those sampling the "western" hemisphere showing larger time separations between the two phases. These observations can be explained by models with P velocity gradients of 0.0806 (km/s)/ 200 km for the "western" hemisphere and 0.114 (km/s)/200 km for the "eastern" hemisphere at the bottom of the outer core. Alternatively, these observations can also be explained by models with different velocity structures at the bottom 200 km of the mantle with P velocity variations in an order of 3 percent with respect to PREM. Broadband PKP observations after the PKP caustics (145o - 147o), on the other hand, provide high-quality constraints on the seismic structures at both the top of the inner core and the bottom of

GSM-PKI solution enabling secure mobile communications.

PubMed

Jelekäinen, Pekka

2004-03-31

Because of its wide distribution and ease of use, the mobile phone, as a reliable personal communications channel, offers an excellent basis for the provision of reliable electronic communications services. In Finland, ca. 75% of the citizens have a mobile phone and, at present and most likely also in the future, it is the most widely spread service channel allowing reliable electronic communications. Despite the restricted functions of the mobile phone, the citizens can use the phone also as a communications medium. In 2001, the Finns sent over 1 billion SMS messages. In Finland, TeliaSonera Finland Oyi and the Population Register Centre (PRC) have closed a co-operation agreement with the aim of creating a mobile phone service for the electronic identification of a person. The co-operation launched is a significant development project from the perspective of the citizens. As a result, the consumers will have a new alternative for reliable electronic communications and commerce in data networks in addition to the electronic identification card. In the future, it will be possible to use the services of both public administration and the private sector by means of a mobile phone more reliably than before, without a physical visit, e.g. to a health centre or to another provider of healthcare services. The possibility of identification and signature by a mobile phone allows an easier provision of versatile services irrespective of time and place, because, in addition to voice, text message, and WAP functions, the service can be utilised also in communications services through the Internet, in which case, the mobile phone acts like a card reader. From the perspective of reliable personal mobile communications, the healthcare sector is one of the most significant and challenging application areas.

Personal Knowledge Integrators

ERIC Educational Resources Information Center

White, David C.

2013-01-01

This paper discusses, in the context of personal learning environments, the need for Personal Knowledge Integrators--PKI's or Knowers. It first illustrates and establishes the need for Knowers with usage scenarios and people's requirements. It then describes the elements required to make a Knower which can exchange information with other Knowers,…

Pharmacological characterization of the bifunctional opioid ligand H-Dmt-Tic-Gly-NH-Bzl (UFP-505).

PubMed

Dietis, N; McDonald, J; Molinari, S; Calo, G; Guerrini, R; Rowbotham, D J; Lambert, D G

2012-02-01

While producing good-quality analgesia, µ-opioid (MOP) receptor activation produces a number of side-effects including tolerance. Simultaneous blockade of δ-opioid (DOP) receptors has been shown to reduce tolerance to morphine. Here, we characterize a prototype bifunctional opioid H-Dmt-Tic-Gly-NH-Bzl (UFP-505). We measured receptor binding affinity in Chinese hamster ovary (CHO) cells expressing recombinant human MOP, DOP, k-opioid (KOP), nociceptin/orphanin (NOP) receptors. For activation, we measured the binding of GTPγ(35)S to membranes from CHO(hMOP), CHO(hDOP), rat cerebrocortex, and rat spinal cord. In addition, we assessed 'end organ' responses in the guinea pig ileum and mouse vas deferens. UFP-505 bound to CHO(hMOP) and CHO(hDOP) with (binding affinity) pK(i) values of 7.79 and 9.82, respectively. There was a weak interaction at KOP and NOP (pK(i) 6.29 and 5.86). At CHO(hMOP), UFP-505 stimulated GTPγ(35)S binding with potency (pEC(50)) of 6.37 and in CHO(hDOP) reversed the effects of a DOP agonist with affinity (pK(b)) of 9.81 (in agreement with pK(i) at DOP). UFP-505 also stimulated GTPγ(35)S binding in rat cerebrocortex and spinal cord with pEC(50) values of 6.11-6.53. In the guinea pig ileum (MOP-rich preparation), UFP-505 inhibited contractility with pEC(50) of 7.50 and in the vas deferens (DOP-rich preparation) reversed the effects of a DOP agonist with an affinity (pA(2)) of 9.15. We have shown in a range of preparations and assays that UFP-505 behaves as a potent MOP agonist and DOP antagonist; a MOP/DOP bifunctional opioid. Further studies in dual expression systems and whole animals with this prototype are warranted.

End-to-End Service Oriented Architectures (SOA) Security Project

DTIC Science & Technology

2012-02-01

ActivClientforCommonAccessCards/ [CAC3] http://koji.fedoraproject.org/ koji /packageinfo?packageID=5 [CAC4] https://help.ubuntu.com/community...Ubuntu10.4-LTS-32.html [CAC8] http://dodpki.c3pki.chamb.disa.mil/rootca.html [CAC9] http://koji.fedoraproject.org/ koji /packageinfo?packageID=5 [CAC10

cAMP-dependent protein kinase (PKA) complexes probed by complementary differential scanning fluorimetry and ion mobility–mass spectrometry

PubMed Central

Byrne, Dominic P.; Vonderach, Matthias; Ferries, Samantha; Brownridge, Philip J.; Eyers, Claire E.; Eyers, Patrick A.

2016-01-01

cAMP-dependent protein kinase (PKA) is an archetypal biological signaling module and a model for understanding the regulation of protein kinases. In the present study, we combine biochemistry with differential scanning fluorimetry (DSF) and ion mobility–mass spectrometry (IM–MS) to evaluate effects of phosphorylation and structure on the ligand binding, dynamics and stability of components of heteromeric PKA protein complexes in vitro. We uncover dynamic, conformationally distinct populations of the PKA catalytic subunit with distinct structural stability and susceptibility to the physiological protein inhibitor PKI. Native MS of reconstituted PKA R2C2 holoenzymes reveals variable subunit stoichiometry and holoenzyme ablation by PKI binding. Finally, we find that although a ‘kinase-dead’ PKA catalytic domain cannot bind to ATP in solution, it interacts with several prominent chemical kinase inhibitors. These data demonstrate the combined power of IM–MS and DSF to probe PKA dynamics and regulation, techniques that can be employed to evaluate other protein-ligand complexes, with broad implications for cellular signaling. PMID:27444646

The pharmacology of GR203040, a novel, potent and selective non-peptide tachykinin NK1 receptor antagonist.

PubMed Central

Beattie, D. T.; Beresford, I. J.; Connor, H. E.; Marshall, F. H.; Hawcock, A. B.; Hagan, R. M.; Bowers, J.; Birch, P. J.; Ward, P.

1995-01-01

1. The in vitro and in vivo pharmacology of GR203040 ((2S, 3S)-2-methoxy-5-tetrazol-1-yl-benzyl-(2-phenyl-piperidin-3-y l)-amine), a novel, highly potent and selective non-peptide tachykinin NK1 receptor antagonist, was investigated in the present study. 2. GR203040 potently inhibited [3H]-substance P binding to human NK1 receptors expressed in Chinese hamster ovary (CHO) and U373 MG astrocytoma cells, and NK1 receptors in ferret and gerbil cortex (pKi values of 10.3, 10.5, 10.1 and 10.1 respectively). GR203040 had lower affinity at rat NK1 receptors (pKi = 8.6) and little affinity for human NK2 receptors (pKi < 5.0) in CHO cells and NK3 receptors in guinea-pig cortex (pKi < 6.0). With the exception of the histamine H1 receptor (pIC50 = 7.5). GR203040 had little affinity (pIC50 < 6.0) at all non-NK1 receptors and ion channels examined. Furthermore, GR203040 produced only weak inhibition of Na+ currents in SH-SY5Y neuroblastoma and superior cervical ganglion cells (pIC50 values < 4.0). GR203040 produced only weak antagonism of Ca(2+)-evoked contractions of rat isolated portal vein (pKn = 4.1). The enantiomer of GR203040, GR205608 (2R, 3R)-2-methoxy-5-tetrazol-1-yl-benzyl-(2-phenyl-piperidin-3-y l)-amine), had 10,000 fold lower affinity at the human NK1 receptor expressed in CHO cells (pKi = 6.3). 3. In gerbil ex vivo binding experiments, GR203040 produced a dose-dependent inhibition of the binding of [3H]-substance P to cerebral cortical membranes (ED50 = 15 micrograms kg-1 s.c. and 0.42 mg kg-1 p.o.). At 10 micrograms kg-1 s.c., the inhibition of [3H]-substance P binding was maintained for > 6 h. In the rat, GR203040 was less potent (ED50 = 15.4 mg kg-1 s.c.) probably reflecting, at least in part, its lower affinity at the rat NK1 receptor. 4. In guinea-pig isolated ileum and dog isolated middle cerebral and basilar arteries, GR203040 produced a rightward displacement of the concentration-effect curves to substance P methyl ester (SPOMe) with suppression of the

Defense Message System Way Ahead: Conclusions and Recommendations from the Industry Advisory Panel

DTIC Science & Technology

2000-03-01

access terminals • Increasing requirement for authentication and data security for conducting business • Mergers and acquisitions in Internet space...market, used to carry PKI certificates for all types of security services including access control, confidentiality, integrity, and non-repudiation...Wireless access widespread § Unified messaging pervasive § Security /privacy dependent on service provider Long-term § Highly reliable systems

Certificate Revocation Using Fine Grained Certificate Space Partitioning

NASA Astrophysics Data System (ADS)

Goyal, Vipul

A new certificate revocation system is presented. The basic idea is to divide the certificate space into several partitions, the number of partitions being dependent on the PKI environment. Each partition contains the status of a set of certificates. A partition may either expire or be renewed at the end of a time slot. This is done efficiently using hash chains.

Improved security monitoring method for network bordary

NASA Astrophysics Data System (ADS)

Gao, Liting; Wang, Lixia; Wang, Zhenyan; Qi, Aihua

2013-03-01

This paper proposes a network bordary security monitoring system based on PKI. The design uses multiple safe technologies, analysis deeply the association between network data flow and system log, it can detect the intrusion activities and position invasion source accurately in time. The experiment result shows that it can reduce the rate of false alarm or missing alarm of the security incident effectively.

Cardiotoxic and Cardioprotective Features of Chronic β-adrenergic Signaling

PubMed Central

Zhang, Xiaoying; Szeto, Christopher; Gao, Erhe; Tang, Mingxin; Jin, Jianguo; Fu, Qin; Makarewich, Catherine; Ai, Xiaojie; Li, Ying; Tang, Allen; Wang, Jenny; Gao, Hui; Wang, Fang; Ge, Xinyi Joy; Kunapuli, Satya P.; Zhou, Lin; Zeng, Chunyu; Xiang, Kevin Yang; Chen, Xiongwen

2012-01-01

Rationale In the failing heart, persistent β-adrenergic receptor (βAR) activation is thought to induce myocyte death by protein kinase A (PKA)-dependent and PKA-independent activation of calcium/calmodulin-dependent kinase II (CaMKII). β-Adrenergic signaling pathways are also capable of activating cardioprotective mechanisms. Objective This study used a novel PKA inhibitor peptide (PKI) to inhibit PKA activity to test the hypothesis that βAR signaling causes cell death through PKA-dependent pathways and cardioprotection through PKA-independent pathways. Methods and Results In PKI transgenic mice, chronic isoproterenol (ISO) failed to induce cardiac hypertrophy, fibrosis, myocyte apoptosis and depressed cardiac function. In cultured adult feline ventricular myocytes (AFVMs), PKA inhibition protected myocytes from death induced by β1-AR agonists by preventing cytosolic and SR Ca2+ overload and CaMKII activation. PKA inhibition revealed a cardioprotective role of β-adrenergic signaling via cAMP/EPAC /Rap1/Rac/ERK pathway. Selective PKA inhibition causes protection in the heart after myocardial infarction (MI) that was superior to β-blocker therapy. Conclusion These results suggest that selective block of PKA could be a novel heart failure therapy. PMID:23104882

A transmission security framework for email-based telemedicine.

PubMed

Caffery, Liam J; Smith, Anthony C

2010-01-01

Encryption is used to convert an email message to an unreadable format thereby securing patient privacy during the transmission of the message across the Internet. Two available means of encryption are: public key infrastructure (PKI) used in conjunction with ordinary email and secure hypertext transfer protocol (HTTPS) used by secure web-mail applications. Both of these approaches have advantages and disadvantages in terms of viability, cost, usability and compliance. The aim of this study was develop an instrument to identify the most appropriate means of encrypting email communication for telemedicine. A multi-method approach was used to construct the instrument. Technical assessment and existing bodies of knowledge regarding the utility of PKI were analyzed, along with survey results from users of Queensland Health's Child and Youth Mental Health Service secure web-mail service. The resultant decision support model identified that the following conditions affect the choice of encryption technology: correspondent's risk perception, correspondent's identification to the security afforded by encryption, email-client used by correspondents, the tolerance to human error and the availability of technical resources. A decision support model is presented as a flow chart to identify the most appropriate encryption for a specific email-based telemedicine service.

Ensemble cryo-EM uncovers inchworm-like translocation of a viral IRES through the ribosome

PubMed Central

Abeyrathne, Priyanka D; Koh, Cha San; Grant, Timothy; Grigorieff, Nikolaus; Korostelev, Andrei A

2016-01-01

Internal ribosome entry sites (IRESs) mediate cap-independent translation of viral mRNAs. Using electron cryo-microscopy of a single specimen, we present five ribosome structures formed with the Taura syndrome virus IRES and translocase eEF2•GTP bound with sordarin. The structures suggest a trajectory of IRES translocation, required for translation initiation, and provide an unprecedented view of eEF2 dynamics. The IRES rearranges from extended to bent to extended conformations. This inchworm-like movement is coupled with ribosomal inter-subunit rotation and 40S head swivel. eEF2, attached to the 60S subunit, slides along the rotating 40S subunit to enter the A site. Its diphthamide-bearing tip at domain IV separates the tRNA-mRNA-like pseudoknot I (PKI) of the IRES from the decoding center. This unlocks 40S domains, facilitating head swivel and biasing IRES translocation via hitherto-elusive intermediates with PKI captured between the A and P sites. The structures suggest missing links in our understanding of tRNA translocation. DOI: http://dx.doi.org/10.7554/eLife.14874.001 PMID:27159452

32-channel single photon counting module for ultrasensitive detection of DNA sequences

NASA Astrophysics Data System (ADS)

Gudkov, Georgiy; Dhulla, Vinit; Borodin, Anatoly; Gavrilov, Dmitri; Stepukhovich, Andrey; Tsupryk, Andrey; Gorbovitski, Boris; Gorfinkel, Vera

2006-10-01

We continue our work on the design and implementation of multi-channel single photon detection systems for highly sensitive detection of ultra-weak fluorescence signals, for high-performance, multi-lane DNA sequencing instruments. A fiberized, 32-channel single photon detection (SPD) module based on single photon avalanche diode (SPAD), model C30902S-DTC, from Perkin Elmer Optoelectronics (PKI) has been designed and implemented. Unavailability of high performance, large area SPAD arrays and our desire to design high performance photon counting systems drives us to use individual diodes. Slight modifications in our quenching circuit has doubled the linear range of our system from 1MHz to 2MHz, which is the upper limit for these devices and the maximum saturation count rate has increased to 14 MHz. The detector module comprises of a single board computer PC-104 that enables data visualization, recording, processing, and transfer. Very low dark count (300-1000 counts/s), robust, efficient, simple data collection and processing, ease of connectivity to any other application demanding similar requirements and similar performance results to the best commercially available single photon counting module (SPCM from PKI) are some of the features of this system.

Ascl1-induced neuronal differentiation of P19 cells requires expression of a specific inhibitor protein of cAMP-dependent protein kinase

PubMed Central

Huang, Holly S.; Turner, David L.; Thompson, Robert C.; Uhler, Michael D.

2011-01-01

cAMP-dependent protein kinase (PKA) plays a critical role in nervous system development by modulating sonic hedgehog and bone morphogenetic protein signaling. In the current studies, P19 embryonic carcinoma cells were neuronally differentiated by expression of the proneural basic helix-loop-helix transcription factor Ascl1. After expression of Ascl1, but prior to expression of neuronal markers such as microtubule associated protein 2 and neuronal β-tubulin, P19 cells demonstrated a large, transient increase in both mRNA and protein for the endogenous protein kinase inhibitor (PKI)β. PKIβ-targeted shRNA constructs both reduced the levels of PKIβ expression and blocked the neuronal differentiation of P19 cells. This inhibition of differentiation was rescued by transfection of a shRNA-resistant expression vector for the PKIβ protein, and this rescue required the PKA-specific inhibitory sequence of the PKIβprotein. PKIβ played a very specific role in the Ascl1-mediated differentiation process since other PKI isoforms were unable to rescue the deficit conferred by shRNA-mediated knockdown of PKIβ. Our results define a novel requirement for PKIβ and its inhibition of PKA during neuronal differentiation of P19 cells. PMID:21623794

Public Key Infrastructure Increment 2 (PKI Inc 2)

DTIC Science & Technology

2016-03-01

DoD - Department of Defense DoDAF - DoD Architecture Framework FD - Full Deployment FDD - Full Deployment Decision FY - Fiscal Year IA...experienced due to a delay in achieving the FDD . The Critical Change Report was provided to Congress on July 11, 2014. Firm, Fixed-Price Feasibility...to a delay in achieving the FDD . To support the Critical Change Report, the NSA Cost Estimating organization prepared a cost estimate that was

PDE4 and mAKAPβ are nodal organizers of β2-ARs nuclear PKA signaling in cardiac myocytes.

PubMed

Bedioune, Ibrahim; Lefebvre, Florence; Lechêne, Patrick; Varin, Audrey; Domergue, Valérie; Kapiloff, Michael S; Fischmeister, Rodolphe; Vandecasteele, Grégoire

2018-05-03

β1- and β2-adrenergic receptors (β-ARs) produce different acute contractile effects on the heart partly because they impact on different cytosolic pools of cAMP-dependent protein kinase (PKA). They also exert different effects on gene expression but the underlying mechanisms remain unknown. The aim of this study was to understand the mechanisms by which β1- and β2-ARs regulate nuclear PKA activity in cardiomyocytes. We used cytoplasmic and nuclear targeted biosensors to examine cAMP signals and PKA activity in adult rat ventricular myocytes upon selective β1- or β2-ARs stimulation. Both β1- and β2-AR stimulation increased cAMP and activated PKA in the cytoplasm. While the two receptors also increased cAMP in the nucleus, only β1-ARs increased nuclear PKA activity and up-regulated the PKA target gene and pro-apoptotic factor, inducible cAMP element repressor (ICER). Inhibition of PDE4, but not Gi, PDE3, GRK2 nor caveolae disruption disclosed nuclear PKA activation and ICER induction by β2-ARs. Both nuclear and cytoplasmic PKI prevented nuclear PKA activation and ICER induction by β1-ARs, indicating that PKA activation outside the nucleus is required for subsequent nuclear PKA activation and ICER mRNA expression. Cytoplasmic PKI also blocked ICER induction by β2-AR stimulation (with concomitant PDE4 inhibition). However, in this case nuclear PKI decreased ICER up-regulation by only 30%, indicating that other mechanisms are involved. Down-regulation of mAKAPβ partially inhibited nuclear PKA activation upon β1-AR stimulation, and drastically decreased nuclear PKA activation upon β2-AR stimulation in the presence of PDE4 inhibition. β1- and β2-ARs differentially regulate nuclear PKA activity and ICER expression in cardiomyocytes. PDE4 insulates a mAKAPβ-targeted PKA pool at the nuclear envelope that prevents nuclear PKA activation upon β2-AR stimulation.

Pharmacological characterization of the bradykinin B2 receptor: inter-species variability and dissociation between binding and functional responses

PubMed Central

Paquet, J -L; Luccarini, J -M; Fouchet, C; Defrêne, E; Loillier, B; Robert, C; Bélichard, P; Cremers, B; Pruneau, D

1999-01-01

The present study addresses the differences in binding profiles and functional properties of the human and rat bradykinin (BK) B2 receptor using various kinin receptor peptide derivatives as well as the non-peptide receptor antagonists WIN 64338 (phosphonium, [[4-[[2-[[bis(cyclohexylamino)methylene]amino]-3-(2-naphtalenyl)1-oxopropyl]amino]-phenyl]-methyl]tributyl, chloride, monohydro-chloride), and FR173657 (E)-3-(6-acetamido-3-pyridyl)-N-[-N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl)oxymethyl]-phenyl]N-methylamino carbonyl methyl] acrylamide. [3H]-BK bound with a similar affinity to membranes of Chinese hamster ovary cells (CHO-K1) expressing the cloned human (hB2-CHO) or rat (rB2-CHO) B2 receptor, human embryonic intestine cells (INT407) expressing the native B2 receptor, human umbilical vein (HUV) and rat uterus (RU). WIN 64338 and FR173657 bound with a 3.8–6.6 fold and 7.0–16.3 fold higher affinity the rat than the human B2 receptor, respectively. The affinity values of BK derivatives as well as non-peptide antagonists were reduced by 6–23 fold in physiological HBSS compared to low ionic strength TES binding buffer. BK (0.01–3000 nM) increased inositol triphosphates (IP3) levels in hB2-CHO, rB2-CHO and INT407 cells. The B2 receptor antagonist, Hoe 140 (D-Arg0-[ Hyp3, Thi5, D-Tic7, Oic8]-BK) at 10−7 M, significantly shifted to the right the IP3 response curves to BK giving apparent pKB values of 8.56, 9.79 and 8.84 for hB2-CHO, rB2-CHO and INT407 cells, respectively. In human isolated umbilical vein, Hoe 140, D-Arg0-[Hyp3, D-Phe7, Leu8]-BK and NPC 567 had a lower potency in functional assays (pKB 8.18, 5.77 and 5.60, respectively) than expected from their affinity in binding studies (pKi 10.52, 8.64 and 8.27, respectively). FR173657 behaved as a high affinity ligand with pKi values of 8.59 and 9.81 and potent competitive antagonist with pKB values of 7.80 and 8.17 in HUV and RU, respectively. FR173657 bound with a similar affinity the cloned and

Object Signing in Bamboo

DTIC Science & Technology

2000-03-01

Dynamics. Numerous smaller companies have entered the market in just the past year offering similar PKI security solutions in an effort to take advantage...web of social , legal and business interactions that, in some cases, have taken generations to mature. We use common instruments to establish trust...types of digital certificates on the market today. However, with the recent development of object signing tools, some of the later browsers are incapable

Simultaneous Time, Wavelength and Intensity Measurement of Optical Memory Subsystems

DTIC Science & Technology

1998-07-01

SIMULTANEOUS TIME, WAVELENGTH AND INTENSITY MEASUREMENT PE - 61102F OF OPTICAL MEMORY SUBSYSTEMS PR - 2300 6. AUTHOR( S ) TA - 06 WU -03 Joseph Osman and...Rebecca Bussjager 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER AFRL/SNDP25 letnic AFRL-SN-RS-TR- 1998...12025 Electronic Pky Rome, NY 13441-4515 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY REPORT NUMBER

Federated Ground Station Network Model and Interface Specification

DTIC Science & Technology

2014-12-01

interface definition language JSON JavaScript Object Notation LEO low Earth orbit LNA low-noise amplifier MC3 Mobile CubeSat Command and Control...Naval Research Laboratory OQPSK offset quadrature phase-shift keying xviii P2P peer-to-peer PKI public key infrastructure REST Representational...enhanced our work being performed on the Mobile CubeSat Command and Control (MC3) ground station network. You also provided crucial guidance from

Information Sharing for Medical Triage Tasking During Mass Casualty/Humanitarian Operations

DTIC Science & Technology

2009-12-01

military patrol units or surreptitious " cloak and dagger " fact gathering missions to gain photographic/video graphic data for dissemination to the...fractured command and control organization and retarded deployment of resources. Tragedies such as Hurricane Katrina in 2005, the September 11 attacks of...with PKI certificates and HMAC protection from replay attacks and UDP flooding [17]. 3. Triage Graphical User Interface (GUI) Currently the GUI for

Prototype Military Message Form (P772) and Mail List Agent (MLA) for National MMHS

DTIC Science & Technology

2006-12-01

Bakanliklar Ankara TURKEY murat.ucuncu@tr.net A. Betul SASIOGLU National Research Institute of Electronics and Cryptology ( TUBITAK – UEKAE) PK.74...Electronics and Cryptology ( TUBITAK – UEKAE) was used in the system. 3. THE PROTOTYPE NATIONAL MAMF ARCHITECTURE The new national military message...System” [2] ACP 123, "Common Messaging Strategy and Procedures” [3] MA3 ASYA, “PKI Software Developed by Turkish TUBITAK UEKAE” [4] ITU-T X.500

Three Types of Earth's Inner Core Boundary

NASA Astrophysics Data System (ADS)

Tian, D.; Wen, L.

2017-12-01

The Earth's inner core boundary (ICB) is the site where the liquid outer core solidifies and the solid inner core grows. Thus, the fine-scale structure of the ICB is important for our understanding of the thermo-compositional state of the Earth's core. In this study, we collect a large set of seismic records with high-quality pre-critical PKiKP and PcP phase pairs, recorded by two dense seismic arrays, Hi-net in Japan and USArray in US. This dataset samples the ICB regions beneath East Asia, Mexico and the Bering Sea. We use differential travel times, amplitude ratios and waveform differences between PKiKP and PcP phases to constrain fine-scale structure of the ICB. The sampled ICB can be grouped into three types based on their seismic characteristics: (1) a simple ICB with a flat and sharp boundary, (2) a bumpy ICB with topographic height changes of 10 km, and (3) a localized mushy ICB with laterally varying thicknesses of 4-8 km. The laterally varying fine-scale structure of the ICB indicates existence of complex small-scale forces at the surface and a laterally varying solidification process of the inner core due to lateral variation of thermo-compositional condition near the ICB.

Unified Communications: Simplifying DoD Communication Methods

DTIC Science & Technology

2013-04-18

private key to encrypt the hash. The encrypted hash, together with some other information, such as the hashing algorithm , is known as a digital...virtual private network (VPN). The use of a VPN would allow users to access corporate data while encrypting traffic.35 Another layer of protection would...sign and encrypt emails as well as controlling access to restricted sites. PKI uses a combination of public and private keys for encryption and

Common Criteria for Information Technology Security Evaluation: Department of Defense Public Key Infrastructure and Key Management Infrastructure Token Protection Profile (Medium Robustness)

DTIC Science & Technology

2002-03-22

may be derived from detailed inspection of the IC itself or from illicit appropriation of design information. Counterfeit smart cards can be mass...Infrastructure (PKI) as the Internet to securely and privately exchange data and money through the use of a public and a private cryptographic key pair...interference devices (SQDIS), electrical testing, and electron beam testing. • Other attacks, such as UV or X-rays or high temperatures, could cause erasure

Securing Wireless Local Area Networks with GoC PKI

DTIC Science & Technology

2007-10-01

de réseau privé virtuel (RPV) sans fil sur un banc d’essai dans le laboratoire des Opérations d’information de réseau (OIR) pour des ...locaux sans fil (WLAN) dans les réseaux d’entreprise du gouvernement. Dans ce rapport, on présente les résultats de travaux complémentaires qui tirent...mutuelle, l’autorisation, la protection et l’intégrité des données, ainsi que la gestion et la diffusion des politiques sur les

Recent Developments: PKI Square Dish for the Soleras Project

NASA Technical Reports Server (NTRS)

Rogers, W. E.

1984-01-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

Recent developments: PKI square dish for the Soleras Project

NASA Astrophysics Data System (ADS)

Rogers, W. E.

1984-03-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

Research in DRM architecture based on watermarking and PKI

NASA Astrophysics Data System (ADS)

Liu, Ligang; Chen, Xiaosu; Xiao, Dao-ju; Yi, Miao

2005-02-01

Analyze the virtue and disadvantage of the present digital copyright protecting system, design a kind of security protocol model of digital copyright protection, which equilibrium consider the digital media"s use validity, integrality, security of transmission, and trade equity, make a detailed formalize description to the protocol model, analyze the relationship of the entities involved in the digital work copyright protection. The analysis of the security and capability of the protocol model shows that the model is good at security and practicability.

Seismic Structure in the Vicinity of the Inner Core Boundary beneath northeastern Asia

NASA Astrophysics Data System (ADS)

Ibourichene, A. S.; Romanowicz, B. A.

2016-12-01

The inner core boundary (ICB) separates the solid inner core from the liquid outer core. The crystallization of iron occurring at this limit induces the expulsion of lighter elements such as H, O, S, Si into the outer core, generating chemically-driven convection, which provides power for the geodynamo. Both the F layer, right above the ICB, and the uppermost inner core, are affected by this process so that their properties provide important constraints for a better understanding of core dynamics and, ultimately, the generation and sustained character of the earth's magnetic field. In this study, we investigate the evolution of model parameters (P-velocity, density and quality factor) with depth in the vicinity of the ICB. For this purpose, we combine observations of two body wave phases sensitive to this region: the PKP(DF) phase refracted in the inner core and the PKiKP reflected on the ICB. Variations in the PKP(DF)/PKiKP amplitude ratio and PKP(DF)-PKiKP differential travel times can be related to structure around the ICB. We use waveform data from earthquakes located in Sumatra and recorded by the dense USArray seismic network, which allows us to sample ICB structure beneath northeastern Asia. Observed waveforms are compared to synthetics computed using the DSM method (e.g., Geller et Takeuchi, 1995) in model AK135 (e.g., Montagner & Kennett, 1996) in order to measure amplitude and travel time anomalies. Previous studies (e.g., Tanaka, 1997 ; Cao and Romanowicz, 2004, Yu and Wen, 2006; Waszek and Deuss, 2011) have observed an hemispherical pattern in the vicinity of the ICB exhibiting a faster and more attenuated eastern hemisphere compared to the western hemisphere. The region studied is located in the eastern hemisphere. We find that, on average, travel time anomalies are consistent with previous studies of the eastern hemisphere, however, amplitude ratios are not. We conduct a parameter search for the 1D model that best fits our data. We also consider

MEN15596, a novel nonpeptide tachykinin NK2 receptor antagonist.

PubMed

Cialdai, Cecilia; Tramontana, Manuela; Patacchini, Riccardo; Lecci, Alessandro; Catalani, Claudio; Catalioto, Rose-Marie; Meini, Stefania; Valenti, Claudio; Altamura, Maria; Giuliani, Sandro; Maggi, Carlo Alberto

2006-11-07

The pharmacological profile of MEN15596 or (6-methyl-benzo[b]thiophene-2-carboxylic acid [1-(2-phenyl-1R-{[1-(tetrahydropyran-4-ylmethyl)-piperidin-4-ylmethyl]-carbamoyl}-ethylcarbamoyl)-cyclopentyl]-amide), a novel potent and selective tachykinin NK2 receptor antagonist endowed with oral activity, is described. At the human recombinant tachykinin NK2 receptor, MEN15596 showed subnanomolar affinity (pKi 10.1) and potently antagonized (pKB 9.1) the neurokinin A-induced intracellular calcium release. MEN15596 selectivity for the tachykinin NK2 receptor was assessed by binding studies at the recombinant tachykinin NK1 (pKi 6.1) and NK3 (pKi 6.4) receptors, and at a number of 34 molecular targets including receptors, transporters and ion channels. In isolated smooth muscle preparations MEN15596 showed a marked species selectivity at the tachykinin NK2 receptor with the highest antagonist potency in guinea-pig colon, human and pig bladder (pKB 9.3, 9.2 and 8.8, respectively) whereas it was three orders of magnitude less potent in the rat and mouse urinary bladder (pKB 6.3 and 5.8, respectively). In agreement with binding experiments, MEN15596 showed low potency in blocking selective NK1 or NK3 receptor agonist-induced contractions of guinea-pig ileum preparations (pA2

JPRS Report, East Asia, Southeast Asia.

DTIC Science & Technology

1988-08-31

Defends Foreign Aid, Loans 2 Regional Governments Instructed To Trace PKI Remnants 2 Biographic Items on Military, Government Leaders 3 Brig...DAP Leader Briefs Auckland’s Malaysian Students on National Issues 17 Minister Sees Lessening of School Requirements, Discrimination Against Chinese...Vietnamese Refugees Economic Migrants !!.."!"!"""""" 21 Opinion Leaders Debate Over Petition to King !.!"""""."."!."."!."!"!""! 22 Columnist

Domain Name Server Security (DNSSEC) Protocol Deployment

DTIC Science & Technology

2014-10-01

all the time. For mobile devices, end-system validation is much more difficult due to the state of their networks, many of which do not allow...way to distribute keying information than the current public-key infrastructure (PKI) allows. In addition, it will take work to convince CDNs and...Control Protocol (TCP) or even DNS over Secure Sockets Layer (SSL). One of the important outcomes of our work is the realization that that a " mobile

AliEn—ALICE environment on the GRID

NASA Astrophysics Data System (ADS)

Saiz, P.; Aphecetche, L.; Bunčić, P.; Piskač, R.; Revsbech, J.-E.; Šego, V.; Alice Collaboration

2003-04-01

AliEn ( http://alien.cern.ch) (ALICE Environment) is a Grid framework built on top of the latest Internet standards for information exchange and authentication (SOAP, PKI) and common Open Source components. AliEn provides a virtual file catalogue that allows transparent access to distributed datasets and a number of collaborating Web services which implement the authentication, job execution, file transport, performance monitor and event logging. In the paper we will present the architecture and components of the system.

Synthesis and biological evaluation of a series of aminoalkyl-tetralones and tetralols as dual dopamine/serotonin ligands.

PubMed

Carro, Laura; Torrado, María; Raviña, Enrique; Masaguer, Christian F; Lage, Sonia; Brea, José; Loza, María I

2014-01-01

A series of novel α-tetralone and α-tetralol derivatives was synthesized, and their binding affinities for 5-HT(2A) and D₂ receptors, the most important targets implicated in the anti-schizophrenia drug action, were evaluated to elucidate how substitutions in the aromatic ring of the pharmacophore affect to the affinity or selectivity for these receptors. The replacement of the H-7 in the tetrahydronaphthalene system by an amino group resulted in privileged 5-HT(2A) affinity of the 6-fluorobenzo[d]isoxazol derivative 36 and the alcohol 25 both showing a pK(i) value for 5-HT(2A) higher than 8.3 and good binding affinities for D₂ receptor leading to a Meltzer's ratio characteristic of an atypical antipsychotic profile. Additionally, a small collection of 3-aminomethyltetralone derivatives was prepared and examined here for their affinities and selectivities as 5-HT(2A)/D₂ dual ligands. Compound 11 shows the best profile with good pKi values for 5-HT(2A) and D₂ receptors leading to a Meltzer's ratio characteristic of a typical antipsychotic behaviour. These three compounds behaved as competitive antagonists of both 5-HT(2A) and D₂ receptors, and might be promising pharmacological tools for the investigation of the dual function of the 5HT(2A)-D₂ ligands. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

A DNA-Inspired Encryption Methodology for Secure, Mobile Ad Hoc Networks

NASA Technical Reports Server (NTRS)

Shaw, Harry

2012-01-01

Users are pushing for greater physical mobility with their network and Internet access. Mobile ad hoc networks (MANET) can provide an efficient mobile network architecture, but security is a key concern. A figure summarizes differences in the state of network security for MANET and fixed networks. MANETs require the ability to distinguish trusted peers, and tolerate the ingress/egress of nodes on an unscheduled basis. Because the networks by their very nature are mobile and self-organizing, use of a Public Key Infra structure (PKI), X.509 certificates, RSA, and nonce ex changes becomes problematic if the ideal of MANET is to be achieved. Molecular biology models such as DNA evolution can provide a basis for a proprietary security architecture that achieves high degrees of diffusion and confusion, and resistance to cryptanalysis. A proprietary encryption mechanism was developed that uses the principles of DNA replication and steganography (hidden word cryptography) for confidentiality and authentication. The foundation of the approach includes organization of coded words and messages using base pairs organized into genes, an expandable genome consisting of DNA-based chromosome keys, and a DNA-based message encoding, replication, and evolution and fitness. In evolutionary computing, a fitness algorithm determines whether candidate solutions, in this case encrypted messages, are sufficiently encrypted to be transmitted. The technology provides a mechanism for confidential electronic traffic over a MANET without a PKI for authenticating users.

Security on Cloud Revocation Authority using Identity Based Encryption

NASA Astrophysics Data System (ADS)

Rajaprabha, M. N.

2017-11-01

As due to the era of cloud computing most of the people are saving there documents, files and other things on cloud spaces. Due to this security over the cloud is also important because all the confidential things are there on the cloud. So to overcome private key infrastructure (PKI) issues some revocable Identity Based Encryption (IBE) techniques are introduced which eliminates the demand of PKI. The technique introduced is key update cloud service provider which is having two issues in it and they are computation and communication cost is high and second one is scalability issue. So to overcome this problem we come along with the system in which the Cloud Revocation Authority (CRA) is there for the security which will only hold the secret key for each user. And the secret key was send with the help of advanced encryption standard security. The key is encrypted and send to the CRA for giving the authentication to the person who wants to share the data or files or for the communication purpose. Through that key only the other user will able to access that file and if the user apply some invalid key on the particular file than the information of that user and file is send to the administrator and administrator is having rights to block that person of black list that person to use the system services.

Global shape mimicry of tRNA within a viral internal ribosome entry site mediates translational reading frame selection

PubMed Central

Au, Hilda H.; Cornilescu, Gabriel; Mouzakis, Kathryn D.; Ren, Qian; Burke, Jordan E.; Lee, Seonghoon; Butcher, Samuel E.; Jan, Eric

2015-01-01

The dicistrovirus intergenic region internal ribosome entry site (IRES) adopts a triple-pseudoknotted RNA structure and occupies the core ribosomal E, P, and A sites to directly recruit the ribosome and initiate translation at a non-AUG codon. A subset of dicistrovirus IRESs directs translation in the 0 and +1 frames to produce the viral structural proteins and a +1 overlapping open reading frame called ORFx, respectively. Here we show that specific mutations of two unpaired adenosines located at the core of the three-helical junction of the honey bee dicistrovirus Israeli acute paralysis virus (IAPV) IRES PKI domain can uncouple 0 and +1 frame translation, suggesting that the structure adopts distinct conformations that contribute to 0 or +1 frame translation. Using a reconstituted translation system, we show that ribosomes assembled on mutant IRESs that direct exclusive 0 or +1 frame translation lack reading frame fidelity. Finally, a nuclear magnetic resonance/small-angle X-ray scattering hybrid approach reveals that the PKI domain of the IAPV IRES adopts an RNA structure that resembles a complete tRNA. The tRNA shape-mimicry enables the viral IRES to gain access to the ribosome tRNA-binding sites and form intermolecular contacts with the ribosome that are necessary for initiating IRES translation in a specific reading frame. PMID:26554019

[Role of caveolin-1 in pulmonary microvascular endothelial cells injury induced by lipopolysaccharide in rat].

PubMed

You, Qing-hai; Zhang, Dan; Sun, Geng-yun; Yue, Yang; Xu, Xiu-juan

2013-12-01

To investigate the role of caveolin-1 (Cav-1) in the modulation of rat pulmonary microvascular endothelial cells (RPMVEC) injury induced by lipopolysaccharide (LPS). Cultured RPMVEC were randomly divided into time-dependent injury group induced by LPS and intervention group in which cells were pretreated by protein kinase A inhibitor (PKI). In the time-dependent injury group, monolayers of cells were constructed to determine permeability changes after 10 μg/mL LPS challenge for 0, 1, 3, 6, 12 and 24 hours with the method of Evans blue-labeled albumin flux across the monolayer (Pd). Western blotting was used to determine the Cav-1 expression after LPS stimulation and the phosphorylation-Cav-1 (p-Cav-1) expression after LPS challenge for 0, 10, 30, 60, 90, 120 minutes. In the intervention group, after pre-treatment with 10 μmol/L PKI for 30 minutes, RPMVECs were challenged with 10 μg/mL LPS, and the expression of p-Cav-1 was determined 30 minutes after LPS challenge, the permeability and the Cav-1 protein expression were assessed by Pd and Western blotting, respectively. Non-stimulation group and single PKI simulation group served as controls. Western blotting revealed that the expression of Cav-1 protein was elevated at 1 hour (2.97 ± 0.07), peaking at 3 hours (3.77 ± 0.37), then it lowered gradually, but it was still higher at 24 hours (1.45 ± 0.18) when compared with 0 hour group (1.12±0.08) with significant differences (F=178.047, P=0.000). After RPMVEC monolayers were challenged by LPS for different periods (0, 1, 3, 6, 12 and 24 hours), there were significant increases in a time-dependent manner in Cav-1 expression in the permeability as measured by Pd [(99.67 ± 4.32)%, (118.17 ± 2.32)%, (159.00 ± 2.61)%, (141.17 ± 2.64)%, (120.17 ± 2.79)% and (108.83 ± 2.04)%, F=345.869, P=0.000] which was similar to the changes in Cav-1 expression. LPS also increased Cav-1 phosphorylation in a time-dependent manner occurring at 10 minutes (2.41 ± 0.11), peaking

3,4-Dihydro-2H-benzoxazinones are 5-HT(1A) receptor antagonists with potent 5-HT reuptake inhibitory activity.

PubMed

Atkinson, Peter J; Bromidge, Steven M; Duxon, Mark S; Gaster, Laramie M; Hadley, Michael S; Hammond, Beverley; Johnson, Christopher N; Middlemiss, Derek N; North, Stephanie E; Price, Gary W; Rami, Harshad K; Riley, Graham J; Scott, Claire M; Shaw, Tracey E; Starr, Kathryn R; Stemp, Geoffrey; Thewlis, Kevin M; Thomas, David R; Thompson, Mervyn; Vong, Antonio K K; Watson, Jeannette M

2005-02-01

Starting from a high throughput screening hit, a series of 3,4-dihydro-2H-benzoxazinones has been identified with both high affinity for the 5-HT(1A) receptor and potent 5-HT reuptake inhibitory activity. The 5-(2-methyl)quinolinyloxy derivative combined high 5-HT(1A/1B/1D) receptor affinities with low intrinsic activity and potent inhibition of the 5-HT reuptake site (pK(i)8.2). This compound also had good oral bioavailability and brain penetration in the rat.

AFRRI (Armed Forces Radiobiology Research Institute) Reports, January- March 1986

DTIC Science & Technology

1986-03-01

cells , calculated from —50 to —40 mV, wap 101 nS4:0-12 (mean+ 8.E. of mean, n = 22 ). 480 E. K. GAL UN AND P. A. SHEEH Y Effect of adherence on zero...and Hagan, M. Effect of radiation on the regulation of sodium-dependent glucose transport in LLC-PKi epithelial cell line: Possible model for...epithelial cells . SR86-9: Mullin, M. J., and Hunt, W. A. Actions of ethanol on voltage-sensitive sodium channels: Effects on neurotoxin-stimulated

Wireless Technology Infrastructures for Authentication of Patients: PKI that Rings

PubMed Central

Sax, Ulrich; Kohane, Isaac; Mandl, Kenneth D.

2005-01-01

As the public interest in consumer-driven electronic health care applications rises, so do concerns about the privacy and security of these applications. Achieving a balance between providing the necessary security while promoting user acceptance is a major obstacle in large-scale deployment of applications such as personal health records (PHRs). Robust and reliable forms of authentication are needed for PHRs, as the record will often contain sensitive and protected health information, including the patient's own annotations. Since the health care industry per se is unlikely to succeed at single-handedly developing and deploying a large scale, national authentication infrastructure, it makes sense to leverage existing hardware, software, and networks. This report proposes a new model for authentication of users to health care information applications, leveraging wireless mobile devices. Cell phones are widely distributed, have high user acceptance, and offer advanced security protocols. The authors propose harnessing this technology for the strong authentication of individuals by creating a registration authority and an authentication service, and examine the problems and promise of such a system. PMID:15684133

Efficient Transmission of DoD PKI Certificates in Tactical Networks

DTIC Science & Technology

2010-01-01

011 the COlll- mand line. To extract individual fields from cert ifica tes, we used the X.509 subset of the C API included with OpenSSL (vl.O.0-bcta2...www.disa.mil/nces. [17J NSA Suite Il Cryptogt"aphy. http://vvv . nsa.gov/ial programs/suiteb_cryptography/index.shtml. [18J OpenSSL : The Open Source toolk

Wireless technology infrastructures for authentication of patients: PKI that rings.

PubMed

Sax, Ulrich; Kohane, Isaac; Mandl, Kenneth D

2005-01-01

As the public interest in consumer-driven electronic health care applications rises, so do concerns about the privacy and security of these applications. Achieving a balance between providing the necessary security while promoting user acceptance is a major obstacle in large-scale deployment of applications such as personal health records (PHRs). Robust and reliable forms of authentication are needed for PHRs, as the record will often contain sensitive and protected health information, including the patient's own annotations. Since the health care industry per se is unlikely to succeed at single-handedly developing and deploying a large scale, national authentication infrastructure, it makes sense to leverage existing hardware, software, and networks. This report proposes a new model for authentication of users to health care information applications, leveraging wireless mobile devices. Cell phones are widely distributed, have high user acceptance, and offer advanced security protocols. The authors propose harnessing this technology for the strong authentication of individuals by creating a registration authority and an authentication service, and examine the problems and promise of such a system.

76 FR 48807 - Public Key Infrastructure (PKI) Certificate Action Form

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-09

...) Certificate Action Form ACTION: Proposed collection; comment request. SUMMARY: The United States Patent and... Certificate Action Form (PTO-2042), which is used by the public to request a new digital certificate, the... applicant. The Certificate Action Form has an accompanying subscriber agreement to ensure that customers...

Identification of protein–protein interfaces by decreased amide proton solvent accessibility

PubMed Central

Mandell, Jeffrey G.; Falick, Arnold M.; Komives, Elizabeth A.

1998-01-01

Matrix-assisted laser desorption ionization–time-of-flight mass spectrometry was used to identify peptic fragments from protein complexes that retained deuterium under hydrogen exchange conditions due to decreased solvent accessibility at the interface of the complex. Short deuteration times allowed preferential labeling of rapidly exchanging surface amides so that primarily solvent accessibility changes and not conformational changes were detected. A single mass spectrum of the peptic digest mixture was analyzed to determine the deuterium content of all proteolytic fragments of the protein. The protein–protein interface was reliably indicated by those peptides that retained more deuterons in the complex compared with control experiments in which only one protein was present. The method was used to identify the kinase inhibitor [PKI(5–24)] and ATP-binding sites in the cyclic-AMP-dependent protein kinase. Three overlapping peptides identified the ATP-binding site, three overlapping peptides identified the glycine-rich loop, and two peptides identified the PKI(5–24)-binding site. A complex of unknown structure also was analyzed, human α-thrombin bound to an 83-aa fragment of human thrombomodulin [TMEGF(4–5)]. Five peptides from thrombin showed significantly decreased solvent accessibility in the complex. Three peptides identified the anion-binding exosite I, confirming ligand competition experiments. Two peptides identified a new region of thrombin near the active site providing a potential mechanism of how thrombomodulin alters thrombin substrate specificity. PMID:9843953

Relationship of D'' structure with the velocity variations near the inner-core boundary

NASA Astrophysics Data System (ADS)

Luo, Sheng-Nian; Ni, Sidao; Helmberger, Don

2002-06-01

Variations in regional differential times between PKiKP (i) and PKIKP (I) have been attributed to hemispheric P-velocity variations of about 1% in the upper 100 km of the inner core (referred to as HIC). The top of the inner core appears relatively fast beneath Asia where D'' is also fast. An alternative interpretation could be the lateral variation in P velocity at the lowermost outer core (HOC) producing the same differential times. To resolve this issue, we introduce the diffracted PKP phase near the B caustic (Bdiff) in the range of 139-145° epicenter distances, and the corresponding differential times between Bdiff and PKiKP and PKIKP as observed on broadband arrays. Due to the long-wavelength nature of Bdiff, we scaled the S-wave tomography model with k values (k ≡ dlnVs/dlnVp) to obtain large-scale P-wave velocity structure in the lower mantle as proposed by earlier studies. Waveform synthetics of Bdiff constructed with small k's predict complex waveforms not commonly observed, confirming the validity of large scaling factor k. With P-velocity in lower mantle constrained at large scale, the extra travel-time constraint imposed by Bdiff helps to resolve the HOC-HIC issue. Our preliminary results suggest k > 2 for the lowermost mantle and support HIC hypothesis. An important implication is that there appears to be a relationship of D'' velocity structures with the structures near the inner core boundary via core dynamics.

Software Acquisition in the Age of Cyber Warfare

DTIC Science & Technology

2011-05-01

s c h o o l o f S Y S T E M S a n d L O G I S T I C S education service research Software Acquisition in the Age of Cyber Warfare Maj...DATE MAY 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Software Acquisition in the Age of Cyber Warfare 5a...AFIT Cyber 200/300 Courses Cyber Warfare IDE Program 34 Special Emphasis On… Enterprise Integration (Active Directory, PKI) Security

Report of the Defense Science Board Summer Study Task Force on Defense Manufacturing Enterprise Strategy

DTIC Science & Technology

1993-09-01

mapped against the desired results. "What To Do" Recomendations PrawnProe Based on reviw of 28 prior sh"(Sa Pki gffs f’orce reconmendafins a’: Q𔃺 Oak...sponsored by the UndAr Secretary of Defense (Acquisition). Mr. Edwin L. Big•ers and Mr. Gordon K . England will serve as Co-Chairmen. ARPA will provide the...sectors, and identify key pilot programs where acquisition and management reforms can be applied. C-8 "What To Do" Rcu-manedadow 1.%% k ~r Tedduce

PKPass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamson, Ryan M.

Password management solutions exist, but few are designed for enterprise systems administrators sharing oncall rotations. Due to the Multi-Factor Level of Assurance 4 effort, DOE is now distributing PIV cards with cryptographically signed certificate and private key pairs to administrators and other security-significant users. We utilize this public key infrastructure (PKI) to encrypt passwords for other recipients in a secure way. This is cross platform (works on OSX and Linux systems), and has already been adopted internally by the NCCS systems administration staff to replace their old password book system.

DAT/SERT Selectivity of Flexible GBR 12909 Analogs Modeled Using 3D-QSAR Methods

PubMed Central

Gilbert, Kathleen M.; Boos, Terrence L.; Dersch, Christina M.; Greiner, Elisabeth; Jacobson, Arthur E.; Lewis, David; Matecka, Dorota; Prisinzano, Thomas E.; Zhang, Ying; Rothman, Richard B.; Rice, Kenner C.; Venanzi, Carol A.

2007-01-01

The dopamine reuptake inhibitor GBR 12909 (1-{2-[bis(4-fluorophenyl)methoxy]ethyl}-4-(3-phenylpropyl)piperazine, 1) and its analogs have been developed as tools to test the hypothesis that selective dopamine transporter (DAT) inhibitors will be useful therapeutics for cocaine addiction. This 3D-QSAR study focuses on the effect of substitutions in the phenylpropyl region of 1. CoMFA and CoMSIA techniques were used to determine a predictive and stable model for the DAT/serotonin transporter (SERT) selectivity (represented by pKi (DAT/SERT)) of a set of flexible analogs of 1, most of which have eight rotatable bonds. In the absence of a rigid analog to use as a 3D-QSAR template, six conformational families of analogs were constructed from six pairs of piperazine and piperidine template conformers identified by hierarchical clustering as representative molecular conformations. Three models stable to y-value scrambling were identified after a comprehensive CoMFA and CoMSIA survey with Region Focusing. Test set correlation validation led to an acceptable model, with q2 = 0.508, standard error of prediction = 0.601, two components, r2 = 0.685, standard error of estimate = 0.481, F value = 39, percent steric contribution = 65, and percent electrostatic contribution = 35. A CoMFA contour map identified areas of the molecule that affect pKi (DAT/SERT). This work outlines a protocol for deriving a stable and predictive model of the biological activity of a set of very flexible molecules. PMID:17127069

Heparin binding epidermal growth factor in renal ischaemia/reperfusion injury.

PubMed

Mulder, Gemma M; Nijboer, Willemijn N; Seelen, Marc A; Sandovici, Maria; Bos, Eelke M; Melenhorst, Wynand B W H; Trzpis, Monika; Kloosterhuis, Niels J; Visser, Lydia; Henning, Rob H; Leuvenink, Henri G D; Ploeg, Rutger J; Sunnarborg, Susan W; van Goor, Harry

2010-06-01

The epidermal growth factor (EGF) receptor and its ligands are crucially involved in the renal response to ischaemia. We studied the heparin binding-epidermal growth factor (HB-EGF), a major ligand for the EGF receptor, in experimental and human ischaemia/reperfusion injury (IRI). HB-EGF mRNA and protein expression was studied in rat kidneys and cultured human tubular (HK-2) cells that were subjected to IRI and in human donor kidneys during transplantation. The effect of EGF receptor inhibition was investigated in vivo and in vitro. Furthermore, urinary HB-EGF protein excretion was studied after renal transplantation. Finally, HB-EGF KO and WT mice were subjected to IRI to study the role of HB-EGF in renal injury. HB-EGF mRNA was significantly up-regulated in the early phase of IRI in rats, cells, and human donor biopsies. Treatment with PKI-166 reduces macrophage accumulation and interstitial alpha-SMA in the early phase of IRI in rats. In vitro, PKI-166 causes a marked reduction in HB-EGF-induced cellular proliferation. Urinary HB-EGF is increased after transplantation compared with control urines from healthy subjects. HB-EGF KO mice subjected to IRI revealed significantly less morphological damage after IRI, compared with WT mice. We conclude that IRI results in early induction of HB-EGF mRNA and protein in vivo and in vitro. Absence of HB-EGF and inhibition of the EGF receptor in the early phase of IRI has protective effects, suggesting a modulating role for HB-EGF.

Matrix-specific protein kinase A signaling regulates p21 activated kinase activation by flow in endothelial cells

PubMed Central

Funk, Steven Daniel; Yurdagul, Arif; Green, Jonette M.; Jhaveri, Krishna A.; Schwartz, Martin Alexander; Orr, A. Wayne

2010-01-01

Rationale Atherosclerosis is initiated by blood flow patterns that activate inflammatory pathways in endothelial cells. Activation of inflammatory signaling by fluid shear stress is highly dependent on the composition of the subendothelial extracellular matrix. The basement membrane proteins laminin and collagen found in normal vessels suppress flow-induced p21 activated kinase (PAK) and NF-κB activation. By contrast, the provisional matrix proteins fibronectin and fibrinogen found in wounded or inflamed vessels support flow-induced PAK and NF-κB activation. PAK mediates both flow-induced permeability and matrix-specific activation of NF-κB. Objective To elucidate the mechanisms regulating matrix-specific PAK activation. Methods and Results We now show that matrix composition does not affect the upstream pathway by which flow activates PAK (integrin activation, Rac). Instead basement membrane proteins enhance flow-induced protein kinase A (PKA) activation, which suppresses PAK. Inhibiting PKA restored flow-induced PAK and NF-κB activation in cells on basement membrane proteins, whereas stimulating PKA inhibited flow-induced activation of inflammatory signaling in cells on fibronectin. PKA suppressed inflammatory signaling through PAK inhibition. Activating PKA by injection of the PGI2 analog iloprost reduced PAK activation and inflammatory gene expression at sites of disturbed flow in vivo, whereas inhibiting PKA by PKI injection enhanced PAK activation and inflammatory gene expression. Inhibiting PAK prevented the enhancement of inflammatory gene expression by PKI. Conclusions Basement membrane proteins inhibit inflammatory signaling in endothelial cells via PKA-dependent inhibition of PAK. PMID:20224042

Inhibition of mRNA export in vertebrate cells by nuclear export signal conjugates

PubMed Central

Pasquinelli, Amy E.; Powers, Maureen A.; Lund, Elsebet; Forbes, Douglass; Dahlberg, James E.

1997-01-01

Leucine-rich nuclear export signals (NESs) are recognized by the NES receptor exportin 1 and are central to the export of multiple shuttling proteins and RNAs. The export of messenger RNA in vertebrates was, however, thought to occur by a different pathway, because inhibition by injection of a synthetic Rev NES conjugate could not be demonstrated. Here we find that peptide conjugates composed of the NES of either protein kinase A inhibitor protein (PKI) or the HIV-1 Rev protein, when coupled to human serum albumin, are potent inhibitors of mRNA and small nuclear RNA export. These results provide direct evidence that mRNA export in vertebrates depends on interactions between an NES and its cognate NES receptors. PKI NES conjugates are significantly more efficient at inhibiting RNA export than are REV NES conjugates, indicating that different NESs may have different abilities to promote protein and RNA export. Surprisingly, an expected control conjugate containing the mutant Rev NES sequence M10 strongly inhibited the export of intronless dihydrofolate reductase mRNA. Nuclear injection of NES peptide conjugates led to mislocalization to the nucleus of 10–20% of the cytoplasmic Ran GTPase-binding protein (RanBP1) indicating that RanBP1 shuttles between the nucleus and the cytoplasm via an NES pathway. These results demonstrate that in vertebrates the export of mRNA, like that of small nuclear RNA, 5S rRNA, and transport factors such as RanBP1, employs NES-mediated molecular machinery. PMID:9405623

Inner core structure behind the PKP core phase triplication

NASA Astrophysics Data System (ADS)

Blom, Nienke A.; Deuss, Arwen; Paulssen, Hanneke; Waszek, Lauren

2015-06-01

The structure of the Earth's inner core is not well known between depths of ˜100-200 km beneath the inner core boundary. This is a result of the PKP core phase triplication and the existence of strong precursors to PKP phases, which hinder the measurement of inner core compressional PKIKP waves at epicentral distances between roughly 143 and 148°. Consequently, interpretation of the detailed structure of deeper regions also remains difficult. To overcome these issues we stack seismograms in slowness and time, separating the PKP and PKIKP phases which arrive simultaneously but with different slowness. We apply this method to study the inner core's Western hemisphere beneath South and Central America using paths travelling in the quasi-polar direction between 140 and 150° epicentral distance, which enables us to measure PKiKP-PKIKP differential traveltimes up to greater epicentral distance than has previously been done. The resulting PKiKP-PKIKP differential traveltime residuals increase with epicentral distance, which indicates a marked increase in seismic velocity for polar paths at depths greater than 100 km compared to reference model AK135. Assuming a homogeneous outer core, these findings can be explained by either (i) inner core heterogeneity due to an increase in isotropic velocity or (ii) increase in anisotropy over the studied depth range. Although this study only samples a small region of the inner core and the current data cannot distinguish between the two alternatives, we prefer the latter interpretation in the light of previous work.

Framework Design of Unified Cross-Authentication Based on the Fourth Platform Integrated Payment

NASA Astrophysics Data System (ADS)

Yong, Xu; Yujin, He

The essay advances a unified authentication based on the fourth integrated payment platform. The research aims at improving the compatibility of the authentication in electronic business and providing a reference for the establishment of credit system by seeking a way to carry out a standard unified authentication on a integrated payment platform. The essay introduces the concept of the forth integrated payment platform and finally put forward the whole structure and different components. The main issue of the essay is about the design of the credit system of the fourth integrated payment platform and the PKI/CA structure design.

Long-Term Holding Capacity of Statically Loaded Anchors in Cohesive Soils

DTIC Science & Technology

1979-01-01

Kos .,es. Hanoiver NH A.RMY~ I-N( IVIN’NLEI)-S. HunmsIlle AL: Finded-Sr. Huintsville. Al. ARMY L.N( \\%AAURWAY S EXP SIA ILihrar%. Vicksburg NIS ARNMY 1...8217CHNOIOG6Y long Beach. C’A(%\\ agnert P()RT11I.ANI) CLNI ENT ASSOC. SKO KIE. 11. )C0REL.Yt: Skokie It. (Rsch & Ic\\ Ilab. lib.) 57 Pki SCON CORP IO~ SON...Sa~ brook CTI R.Q. PALNMER Kaitua. HI ENERGY R&I ADI)N H. Sko \\% ho. %Aashington. DC( -1..’%. NI ERNIEI. %%ashingion D)C \\kNI lAI.BOT Orange CA 58

The 1965 coup and reformasi 1998: two critical moments in Indonesia-Malaysia relations during and after the Cold War.

PubMed

Maksum, Ali; Bustami, Reevany

2014-01-01

This article discusses the significant impact of the two crucial moments in Indonesia namely, the 1965 coup and reformasi (reformation) in May 1998 and the impact towards the Indonesia-Malaysia relationship. History had demonstrated that both events were followed by some changes in the bilateral relationship. The 1965 coup for instance resulted the fall of Sukarno and the collapse of PKI, while reformasi brought the fall of Suharto and the collapse of New Order. However, it was undeniable that the demands of international situation especially during and after the Cold War were significant factor in driving of those events.

PKI solar thermal plant evaluation at Capitol Concrete Products, Topeka, Kansas

NASA Astrophysics Data System (ADS)

Hauger, J. S.; Borton, D. N.

1982-07-01

A system feasibility test to determine the technical and operational feasibility of using a solar collector to provide industrial process heat is discussed. The test is of a solar collector system in an industrial test bed plant at Capitol Concrete Products in Topeka, Kansas, with an experiment control at Sandia National Laboratories, Albuquerque. Plant evaluation will occur during a year-long period of industrial utilization. It will include performance testing, operability testing, and system failure analysis. Performance data will be recorded by a data acquisition system. User, community, and environmental inputs will be recorded in logs, journals, and files. Plant installation, start-up, and evaluation, are anticipated for late November, 1981.

PKI solar thermal plant evaluation at Capitol Concrete Products, Topeka, Kansas

NASA Technical Reports Server (NTRS)

Hauger, J. S.; Borton, D. N.

1982-01-01

A system feasibility test to determine the technical and operational feasibility of using a solar collector to provide industrial process heat is discussed. The test is of a solar collector system in an industrial test bed plant at Capitol Concrete Products in Topeka, Kansas, with an experiment control at Sandia National Laboratories, Albuquerque. Plant evaluation will occur during a year-long period of industrial utilization. It will include performance testing, operability testing, and system failure analysis. Performance data will be recorded by a data acquisition system. User, community, and environmental inputs will be recorded in logs, journals, and files. Plant installation, start-up, and evaluation, are anticipated for late November, 1981.

Increased sensitivity to ionizing radiation by targeting the homologous recombination pathway in glioma initiating cells.

PubMed

Lim, Yi Chieh; Roberts, Tara L; Day, Bryan W; Stringer, Brett W; Kozlov, Sergei; Fazry, Shazrul; Bruce, Zara C; Ensbey, Kathleen S; Walker, David G; Boyd, Andrew W; Lavin, Martin F

2014-12-01

Glioblastoma is deemed the most malignant form of brain tumour, particularly due to its resistance to conventional treatments. A small surviving group of aberrant stem cells termed glioma initiation cells (GICs) that escape surgical debulking are suggested to be the cause of this resistance. Relatively quiescent in nature, GICs are capable of driving tumour recurrence and undergo lineage differentiation. Most importantly, these GICs are resistant to radiotherapy, suggesting that radioresistance contribute to their survival. In a previous study, we demonstrated that GICs had a restricted double strand break (DSB) repair pathway involving predominantly homologous recombination (HR) associated with a lack of functional G1/S checkpoint arrest. This unusual behaviour led to less efficient non-homologous end joining (NHEJ) repair and overall slower DNA DSB repair kinetics. To determine whether specific targeting of the HR pathway with small molecule inhibitors could increase GIC radiosensitivity, we used the Ataxia-telangiectasia mutated inhibitor (ATMi) to ablate HR and the DNA-dependent protein kinase inhibitor (DNA-PKi) to inhibit NHEJ. Pre-treatment with ATMi prior to ionizing radiation (IR) exposure prevented HR-mediated DNA DSB repair as measured by Rad51 foci accumulation. Increased cell death in vitro and improved in vivo animal survival could be observed with combined ATMi and IR treatment. Conversely, DNA-PKi treatment had minimal impact on GICs ability to resolve DNA DSB after IR with only partial reduction in cell survival, confirming the major role of HR. These results provide a mechanistic insight into the predominant form of DNA DSB repair in GICs, which when targeted may be a potential translational approach to increase patient survival. Copyright © 2014. Published by Elsevier B.V.

Novel, customizable scoring functions, parameterized using N-PLS, for structure-based drug discovery.

PubMed

Catana, Cornel; Stouten, Pieter F W

2007-01-01

The ability to accurately predict biological affinity on the basis of in silico docking to a protein target remains a challenging goal in the CADD arena. Typically, "standard" scoring functions have been employed that use the calculated docking result and a set of empirical parameters to calculate a predicted binding affinity. To improve on this, we are exploring novel strategies for rapidly developing and tuning "customized" scoring functions tailored to a specific need. In the present work, three such customized scoring functions were developed using a set of 129 high-resolution protein-ligand crystal structures with measured Ki values. The functions were parametrized using N-PLS (N-way partial least squares), a multivariate technique well-known in the 3D quantitative structure-activity relationship field. A modest correlation between observed and calculated pKi values using a standard scoring function (r2 = 0.5) could be improved to 0.8 when a customized scoring function was applied. To mimic a more realistic scenario, a second scoring function was developed, not based on crystal structures but exclusively on several binding poses generated with the Flo+ docking program. Finally, a validation study was conducted by generating a third scoring function with 99 randomly selected complexes from the 129 as a training set and predicting pKi values for a test set that comprised the remaining 30 complexes. Training and test set r2 values were 0.77 and 0.78, respectively. These results indicate that, even without direct structural information, predictive customized scoring functions can be developed using N-PLS, and this approach holds significant potential as a general procedure for predicting binding affinity on the basis of in silico docking.

In silico optimization of pharmacokinetic properties and receptor binding affinity simultaneously: a 'parallel progression approach to drug design' applied to β-blockers.

PubMed

Advani, Poonam; Joseph, Blessy; Ambre, Premlata; Pissurlenkar, Raghuvir; Khedkar, Vijay; Iyer, Krishna; Gabhe, Satish; Iyer, Radhakrishnan P; Coutinho, Evans

2016-01-01

The present work exploits the potential of in silico approaches for minimizing attrition of leads in the later stages of drug development. We propose a theoretical approach, wherein 'parallel' information is generated to simultaneously optimize the pharmacokinetics (PK) and pharmacodynamics (PD) of lead candidates. β-blockers, though in use for many years, have suboptimal PKs; hence are an ideal test series for the 'parallel progression approach'. This approach utilizes molecular modeling tools viz. hologram quantitative structure activity relationships, homology modeling, docking, predictive metabolism, and toxicity models. Validated models have been developed for PK parameters such as volume of distribution (log Vd) and clearance (log Cl), which together influence the half-life (t1/2) of a drug. Simultaneously, models for PD in terms of inhibition constant pKi have been developed. Thus, PK and PD properties of β-blockers were concurrently analyzed and after iterative cycling, modifications were proposed that lead to compounds with optimized PK and PD. We report some of the resultant re-engineered β-blockers with improved half-lives and pKi values comparable with marketed β-blockers. These were further analyzed by the docking studies to evaluate their binding poses. Finally, metabolic and toxicological assessment of these molecules was done through in silico methods. The strategy proposed herein has potential universal applicability, and can be used in any drug discovery scenario; provided that the data used is consistent in terms of experimental conditions, endpoints, and methods employed. Thus the 'parallel progression approach' helps to simultaneously fine-tune various properties of the drug and would be an invaluable tool during the drug development process.

Measuring the seismic velocity in the top 15 km of Earth's inner core

NASA Astrophysics Data System (ADS)

Godwin, Harriet; Waszek, Lauren; Deuss, Arwen

2018-01-01

We present seismic observations of the uppermost layer of the inner core. This was formed most recently, thus its seismic features are related to current solidification processes. Previous studies have only constrained the east-west hemispherical seismic velocity structure in the Earth's inner core at depths greater than 15 km below the inner core boundary. The properties of shallower structure have not yet been determined, because the seismic waves PKIKP and PKiKP used for differential travel time analysis arrive close together and start to interfere. Here, we present a method to make differential travel time measurements for waves that turn in the top 15 km of the inner core, and measure the corresponding seismic velocity anomalies. We achieve this by generating synthetic seismograms to model the overlapping signals of the inner core phase PKIKP and the inner core boundary phase PKiKP. We then use a waveform comparison to attribute different parts of the signal to each phase. By measuring the same parts of the signal in both observed and synthetic data, we are able to calculate differential travel time residuals. We apply our method to data with ray paths which traverse the Pacific hemisphere boundary. We generate a velocity model for this region, finding lower velocity for deeper, more easterly ray paths. Forward modelling suggests that this region contains either a high velocity upper layer, or variation in the location of the hemisphere boundary with depth and/or latitude. Our study presents the first direct seismic observation of the uppermost 15 km of the inner core, opening new possibilities for further investigating the inner core boundary region.

Selective blockade by nicergoline of vascular responses elicited by stimulation of alpha 1A-adrenoceptor subtype in the rat.

PubMed

Alvarez-Guerra, M; Bertholom, N; Garay, R P

1999-01-01

The alpha 1-adrenergic blocking activity of nicergoline was re-examined in rats, with a particular emphasis on alpha 1-adrenoceptor subtypes. In pithed rats, nicergoline and prazosin infused at a single small dose (0.5 microgram/kg/min i.v.) produced a substantial and identical shift to the right of the control dose pressor response curve to the specific alpha 1-agonist cirazoline (ED50 = 4.0 +/- 0.1, 4.0 +/- 0.1 and 0.9 +/- 0.01 microgram/kg i.v. for nicergoline, prazosin and vehicle respectively). In the isolated perfused mesenteric vascular bed, nicergoline strongly inhibited the pressor responses elicited by cirazoline, with approximately 40-fold higher potency (pA2 = 11.1 +/- 0.3) than prazosin (pA2 = 9.5 +/- 0.3). Conversely, nicergoline was 20-fold less potent than prazosin to antagonize the contractile effects of cirazoline in isolated endothelium-denuded aorta (pA2 = 8.6 +/- 0.2 and 9.9 +/- 0.2 for nicergoline and prazosin respectively). Pretreatment of mesenteric vascular beds with chloroethylclonidine did not significantly modify nicergoline antagonistic potency (pA2 = 10.6 +/- 0.2). Nicergoline displaced [3H]-prazosin bound to rat forebrain membranes pretreated with chloroethylclonidine (pKi = 9.9 +/- 0.2) at concentrations 60-fold lower than in rat liver membranes (pKi = 8.1 +/- 0.2). Finally, of the nicergoline metabolites studied, lumilysergol acted as a modest alpha 1 antagonist (bromonicotinic acid was devoid of alpha 1 antagonist activity). In conclusion, nicergoline is a potent and selective alpha 1A-adrenoceptor subtype antagonist, an alpha 1-adrenoceptor subtype which is mainly represented in resistance arteries.

Approach to spatial information security based on digital certificate

NASA Astrophysics Data System (ADS)

Cong, Shengri; Zhang, Kai; Chen, Baowen

2005-11-01

With the development of the online applications of geographic information systems (GIS) and the spatial information services, the spatial information security becomes more important. This work introduced digital certificates and authorization schemes into GIS to protect the crucial spatial information combining the techniques of the role-based access control (RBAC), the public key infrastructure (PKI) and the privilege management infrastructure (PMI). We investigated the spatial information granularity suited for sensitivity marking and digital certificate model that fits the need of GIS security based on the semantics analysis of spatial information. It implements a secure, flexible, fine-grained data access based on public technologies in GIS in the world.

Distributed intrusion detection system based on grid security model

NASA Astrophysics Data System (ADS)

Su, Jie; Liu, Yahui

2008-03-01

Grid computing has developed rapidly with the development of network technology and it can solve the problem of large-scale complex computing by sharing large-scale computing resource. In grid environment, we can realize a distributed and load balance intrusion detection system. This paper first discusses the security mechanism in grid computing and the function of PKI/CA in the grid security system, then gives the application of grid computing character in the distributed intrusion detection system (IDS) based on Artificial Immune System. Finally, it gives a distributed intrusion detection system based on grid security system that can reduce the processing delay and assure the detection rates.

Efficient Authorization of Rich Presence Using Secure and Composed Web Services

NASA Astrophysics Data System (ADS)

Li, Li; Chou, Wu

This paper presents an extended Role-Based Access Control (RBAC) model for efficient authorization of rich presence using secure web services composed with an abstract presence data model. Following the information symmetry principle, the standard RBAC model is extended to support context sensitive social relations and cascaded authority. In conjunction with the extended RBAC model, we introduce an extensible presence architecture prototype using WS-Security and WS-Eventing to secure rich presence information exchanges based on PKI certificates. Applications and performance measurements of our presence system are presented to show that the proposed RBAC framework for presence and collaboration is well suited for real-time communication and collaboration.

Symmetric Key Services Markup Language (SKSML)

NASA Astrophysics Data System (ADS)

Noor, Arshad

Symmetric Key Services Markup Language (SKSML) is the eXtensible Markup Language (XML) being standardized by the OASIS Enterprise Key Management Infrastructure Technical Committee for requesting and receiving symmetric encryption cryptographic keys within a Symmetric Key Management System (SKMS). This protocol is designed to be used between clients and servers within an Enterprise Key Management Infrastructure (EKMI) to secure data, independent of the application and platform. Building on many security standards such as XML Signature, XML Encryption, Web Services Security and PKI, SKSML provides standards-based capability to allow any application to use symmetric encryption keys, while maintaining centralized control. This article describes the SKSML protocol and its capabilities.

Characterization of NK1 and NK2 tachykinin receptors in guinea-pig and rat bronchopulmonary and vascular systems.

PubMed Central

Floch, A.; Fardin, V.; Cavero, I.

1994-01-01

1. NK1 and NK2 tachykinin receptors were characterized in guinea-pig and rat bronchopulmonary systems and in the vasculature of the rat by use of radioligand binding and/or functional studies. 2. The radioligands for NK1 and NK2 receptors ([3H]-SP and [3H]-pNKA, respectively) did not label tachykinin receptors in homogenates of rat lungs or bronchi. In contrast, in the guinea-pig, [3H]-SP bound with high affinity to these tissues (KD = 0.23 +/- 0.08 nM and 0.34 +/- 0.05 nM, for lungs and bronchi, respectively). The total number of binding sites was 4.6 fold greater in bronchus (Bmax = 135 +/- 27 fmol mg-1 protein) than in lung homogenates (Bmax = 29.3 +/- 0.1 fmol mg-1 protein). Furthermore, this binding was markedly displaced by CP-96,345 (pKi = 9.5 +/- 0.1) and RP 67580 (pKi = 7.6 +/- 0.1), antagonists of NK1 receptors, slightly displaced by SR 48968 (pKi = 6.6 +/- 0.1), but not affected by actinomycin D or L-659,877, antagonists of NK2 receptors. Specific binding of [3H]-pNKA, detected in guinea-pig bronchi (KD = 5.2 +/- 0.1 nM, and Bmax = 203 +/- 19 fmol mg-1 protein) but not in lungs, was similarly (40 to 53%) displaced by RP 67580 (1 microM), CP-96,345 (10 and 100 nM) or SR 48968 (10 and 100 nM). The displacement approximately doubled (87 to 91%) when SR 48968 (10 nM) was combined with either RP 67580 (1 microM) or CP-96,345 (10 nM), but not when RP 67580 was combined with CP-96,345. 3. In urethane-anaesthetized guinea-pigs, i.v. injections of the NK1 receptor agonists SP, [Pro9]-SP, [Sar9,Met(O2)11]-SP and septide, as well as the NK2 receptor agonists NKA and [Lys5,MeLeu9,NLeu10]-NKA(4-10) (0.1-10 micrograms kg-1, i.v.), dose-dependently increased lung inflation pressure. The most potent of these peptides were septide and [Lys5, MeLeu9,NLeu10]-NKA(4-10) (EC50 = 0.38 +/- 0.07 and 0.07 +/- 0.02 microgram kg-1, respectively). Interestingly, septide was 130 fold less potent than SP in displacing [3H]-SP from its binding sites in the guinea-pig lung, whereas it

PKI Layer Cake: New Collision Attacks against the Global X.509 Infrastructure

NASA Astrophysics Data System (ADS)

Kaminsky, Dan; Patterson, Meredith L.; Sassaman, Len

Research unveiled in December of 2008 [15] showed how MD5's long-known flaws could be actively exploited to attack the real-worldCertification Authority infrastructure. In this paper, we demonstrate two new classes of collision, which will be somewhat trickier to address than previous attacks against X.509: the applicability of MD2 preimage attacks against the primary root certificate for Verisign, and the difficulty of validating X.509 Names contained within PKCS#10 Certificate Requests.We also draw particular attention to two possibly unrecognized vectors for implementation flaws that have been problematic in the past: the ASN.1 BER decoder required to parsePKCS#10, and the potential for SQL injection fromtext contained within its requests. Finally, we explore why the implications of these attacks are broader than some have realized - first, because Client Authentication is sometimes tied to X.509, and second, because Extended Validation certificates were only intended to stop phishing attacks from names similar to trusted brands. As per the work of Adam Barth and Collin Jackson [4], EV does not prevent an attacker who can synthesize or acquire a "low assurance" certificate for a given name from acquiring the "green bar" EV experience.

Towards Trustable Digital Evidence with PKIDEV: PKI Based Digital Evidence Verification Model

NASA Astrophysics Data System (ADS)

Uzunay, Yusuf; Incebacak, Davut; Bicakci, Kemal

How to Capture and Preserve Digital Evidence Securely? For the investigation and prosecution of criminal activities that involve computers, digital evidence collected in the crime scene has a vital importance. On one side, it is a very challenging task for forensics professionals to collect them without any loss or damage. On the other, there is the second problem of providing the integrity and authenticity in order to achieve legal acceptance in a court of law. By conceiving digital evidence simply as one instance of digital data, it is evident that modern cryptography offers elegant solutions for this second problem. However, to our knowledge, there is not any previous work proposing a systematic model having a holistic view to address all the related security problems in this particular case of digital evidence verification. In this paper, we present PKIDEV (Public Key Infrastructure based Digital Evidence Verification model) as an integrated solution to provide security for the process of capturing and preserving digital evidence. PKIDEV employs, inter alia, cryptographic techniques like digital signatures and secure time-stamping as well as latest technologies such as GPS and EDGE. In our study, we also identify the problems public-key cryptography brings when it is applied to the verification of digital evidence.

Characterization of SB-271046: A potent, selective and orally active 5-HT6 receptor antagonist

PubMed Central

Routledge, Carol; Bromidge, Steven M; Moss, Stephen F; Price, Gary W; Hirst, Warren; Newman, Helen; Riley, Graham; Gager, Tracey; Stean, Tania; Upton, Neil; Clarke, Stephen E; Brown, Anthony M; Middlemiss, Derek N

2000-01-01

SB-271046, potently displaced [3H]-LSD and [125I]-SB-258585 from human 5-HT6 receptors recombinantly expressed in HeLa cells in vitro (pKi 8.92 and 9.09 respectively). SB-271046 also displaced [125I]-SB-258585 from human caudate putamen and rat and pig striatum membranes (pKi 8.81, 9.02 and 8.55 respectively). SB-271046 was over 200 fold selective for the 5-HT6 receptor vs 55 other receptors, binding sites and ion channels. In functional studies on human 5-HT6 receptors SB-271046 competitively antagonized 5-HT-induced stimulation of adenylyl cyclase activity with a pA2 of 8.71. SB-271046 produced an increase in seizure threshold over a wide-dose range in the rat maximal electroshock seizure threshold (MEST) test, with a minimum effective dose of ⩽0.1 mg kg−1 p.o. and maximum effect at 4 h post-dose. The level of anticonvulsant activity achieved correlated well with the blood concentrations of SB-271046 (EC50 of 0.16 μM) and brain concentrations of 0.01–0.04 μM at Cmax. These data, together with the observed anticonvulsant activity of other selective 5-HT6 receptor antagonists, SB-258510 (10 mg kg−1, 2–6 h pre-test) and Ro 04-6790 (1–30 mg kg−1, 1 h pre-test), in the rat MEST test, suggest that the anticonvulsant properties of SB-271046 are likely to be mediated by 5-HT6 receptors. Overall, these studies demonstrate that SB-271046 is a potent and selective 5-HT6 receptor antagonist and is orally active in the rat MEST test. SB-271046 represents a valuable tool for evaluating the in vivo central function of 5-HT6 receptors. PMID:10928964

Inhibition of vascular smooth muscle growth via signaling crosstalk between AMP-activated protein kinase and cAMP-dependent protein kinase

PubMed Central

Stone, Joshua D.; Narine, Avinash; Tulis, David A.

2012-01-01

Abnormal vascular smooth muscle (VSM) growth is central in the pathophysiology of vascular disease yet fully effective therapies to curb this growth are lacking. Recent findings from our lab and others support growth control of VSM by adenosine monophosphate (AMP)-based approaches including the metabolic sensor AMP-activated protein kinase (AMPK) and cAMP-dependent protein kinase (PKA). Molecular crosstalk between AMPK and PKA has been previously suggested, yet the extent to which this occurs and its biological significance in VSM remain unclear. Considering their common AMP backbone and similar signaling characteristics, we hypothesized that crosstalk exists between AMPK and PKA in the regulation of VSM growth. Using rat primary VSM cells (VSMC), the AMPK agonist AICAR increased AMPK activity and phosphorylation of the catalytic Thr172 site on AMPK. Interestingly, AICAR also phosphorylated a suspected PKA-inhibitory Ser485 site on AMPK, and these cumulative events were reversed by the PKA inhibitor PKI suggesting possible PKA-mediated regulation of AMPK. AICAR also increased PKA activity in a reversible fashion. The cAMP stimulator forskolin increased PKA activity and completely ameliorated Ser/Thr protein phosphatase-2C activity, suggesting a potential mechanism of AMPK modulation by PKA since inhibition of PKA by PKI reduced AMPK activity. Functionally, AMPK inhibited serum-stimulated cell cycle progression and cellular proliferation; however, PKA failed to do so. Moreover, AMPK and PKA reduced PDGF-β-stimulated VSMC migration. Collectively, these results show that AMPK is capable of reducing VSM growth in both anti-proliferative and anti-migratory fashion. Furthermore, these data suggest that AMPK may be modulated by PKA and that positive feedback may exist between these two systems. These findings reveal a discrete nexus between AMPK and PKA in VSM and provide basis for metabolically-directed targets in reducing pathologic VSM growth. PMID:23112775

Public key infrastructure for DOE security research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aiken, R.; Foster, I.; Johnston, W.E.

This document summarizes the Department of Energy`s Second Joint Energy Research/Defence Programs Security Research Workshop. The workshop, built on the results of the first Joint Workshop which reviewed security requirements represented in a range of mission-critical ER and DP applications, discussed commonalties and differences in ER/DP requirements and approaches, and identified an integrated common set of security research priorities. One significant conclusion of the first workshop was that progress in a broad spectrum of DOE-relevant security problems and applications could best be addressed through public-key cryptography based systems, and therefore depended upon the existence of a robust, broadly deployed public-keymore » infrastructure. Hence, public-key infrastructure ({open_quotes}PKI{close_quotes}) was adopted as a primary focus for the second workshop. The Second Joint Workshop covered a range of DOE security research and deployment efforts, as well as summaries of the state of the art in various areas relating to public-key technologies. Key findings were that a broad range of DOE applications can benefit from security architectures and technologies built on a robust, flexible, widely deployed public-key infrastructure; that there exists a collection of specific requirements for missing or undeveloped PKI functionality, together with a preliminary assessment of how these requirements can be met; that, while commercial developments can be expected to provide many relevant security technologies, there are important capabilities that commercial developments will not address, due to the unique scale, performance, diversity, distributed nature, and sensitivity of DOE applications; that DOE should encourage and support research activities intended to increase understanding of security technology requirements, and to develop critical components not forthcoming from other sources in a timely manner.« less

Studies on molecular properties prediction and histamine H3 receptor affinities of novel ligands with uracil-based motifs.

PubMed

Lipani, Luca; Odadzic, Dalibor; Weizel, Lilia; Schwed, Johannes-Stephan; Sadek, Bassem; Stark, Holger

2014-10-30

The histamine H3 receptor (H3R) plays a role in cognitive and memory processes and is involved in different neurological disorders, including Alzheimer's disease, schizophrenia, and narcolepsy. Therefore, several hH3R antagonists/inverse agonists entered clinical phases for a broad spectrum of mainly centrally occurring diseases. However, many other promising candidates failed due to their pharmacokinetic profile, mostly because of their strong lipophilicity accompanied with low solubility. Analysis of previous potential H3R selective antagonists/inverse agonists, e.g. pitolisant, revealed promising results concerning physicochemical properties and drug-likeness. Herein, a series of new hH3R ligands 8-20 consisting of piperidin-1-yl or piperidin-1-yl-propoxyphenyl coupled to different uracil, thymine, and 5,6-dimethyluracil related moieties, were synthesized, evaluated on their binding properties at the hH3R and the estimation of different physicochemical and drug-likeness properties. Due to the coupling to various positions at pyrimidine-2,4-(1H,3H)-dione, affinity at hH3Rs and drug-likeness parameters have been improved. For instance, compound 9 showed in addition to high affinity at the hH3R (pKi (hH3R) = 8.14) clog S, clog P, LE, LipE, and drug-likeness score values of -4.36, 3.47, 0.34, 4.63, and 1.54, respectively. Also, the methyl substituted analog 17 (pKi (hH3R) = 8.15) revealed LE, LipE and drug-likeness score values of -3.29, 2.47, 0.49, 5.52, and 1.76, respectively. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Dynamic mitochondrial–nuclear redistribution of the immunophilin FKBP51 is regulated by the PKA signaling pathway to control gene expression during adipocyte differentiation

PubMed Central

Toneatto, Judith; Guber, Sergio; Charó, Nancy L.; Susperreguy, Sebastián; Schwartz, Jessica; Galigniana, Mario D.; Piwien-Pilipuk, Graciela

2013-01-01

Summary Glucocorticoids play an important role in adipogenesis through the glucocorticoid receptor (GR) that forms a heterocomplex with Hsp90•Hsp70 and one high molecular weight immunophilin, either FKBP51 or FKBP52. When 3T3-L1 preadipocytes are induced to differentiate, FKBP51 expression progressively increases, whereas FKBP52 decreases, and Hsp90, Hsp70, p23 and Cyp40 remain unchanged. Interestingly, FKBP51 rapidly translocates from mitochondria to the nucleus where it is retained upon its interaction with chromatin and the nuclear matrix. FKBP51 nuclear localization is transient, and after 48 hours it cycles back to mitochondria. Importantly, this dynamic FKBP51 mitochondrial–nuclear shuttling depends on PKA signaling, because its inhibition by PKI or knockdown of PKA-cα by siRNA, prevented FKBP51 nuclear translocation induced by IBMX. In addition, the electrophoretic pattern of migration of FKBP51 is altered by treatment of cells with PKI or knockdown of PKA-cα, suggesting that FKBP51 is a PKA substrate. In preadipocytes, FKBP51 colocalizes with PKA-cα in mitochondria. When adipogenesis is triggered, PKA-cα also moves to the nucleus colocalizing with FKBP51 mainly in the nuclear lamina. Moreover, FKBP51 and GR interaction increases when preadipocytes are induced to differentiate. GR transcriptional capacity is reduced when cells are incubated in the presence of IBMX, forskolin or dibutyryl-cAMP, compounds that induced FKBP51 nuclear translocation, but not by a specific activator of EPAC. FKBP51 knockdown facilitates adipogenesis, whereas ectopic expression of FKBP51 blocks adipogenesis. These findings indicate that the dynamic mitochondrial–nuclear shuttling of FKBP51 regulated by PKA may be key in fine-tuning the transcriptional control of GR target genes required for the acquisition of adipocyte phenotype. PMID:24101724

Key exchange using biometric identity based encryption for sharing encrypted data in cloud environment

NASA Astrophysics Data System (ADS)

Hassan, Waleed K.; Al-Assam, Hisham

2017-05-01

The main problem associated with using symmetric/ asymmetric keys is how to securely store and exchange the keys between the parties over open networks particularly in the open environment such as cloud computing. Public Key Infrastructure (PKI) have been providing a practical solution for session key exchange for loads of web services. The key limitation of PKI solution is not only the need for a trusted third partly (e.g. certificate authority) but also the absent link between data owner and the encryption keys. The latter is arguably more important where accessing data needs to be linked with identify of the owner. Currently available key exchange protocols depend on using trusted couriers or secure channels, which can be subject to man-in-the-middle attack and various other attacks. This paper proposes a new protocol for Key Exchange using Biometric Identity Based Encryption (KE-BIBE) that enables parties to securely exchange cryptographic keys even an adversary is monitoring the communication channel between the parties. The proposed protocol combines biometrics with IBE in order to provide a secure way to access symmetric keys based on the identity of the users in unsecure environment. In the KE-BIOBE protocol, the message is first encrypted by the data owner using a traditional symmetric key before migrating it to a cloud storage. The symmetric key is then encrypted using public biometrics of the users selected by data owner to decrypt the message based on Fuzzy Identity-Based Encryption. Only the selected users will be able to decrypt the message by providing a fresh sample of their biometric data. The paper argues that the proposed solution eliminates the needs for a key distribution centre in traditional cryptography. It will also give data owner the power of finegrained sharing of encrypted data by control who can access their data.

Phosphodiesterase 4 regulates the migration of B16-F10 melanoma cells.

PubMed

Watanabe, Yoshihiro; Murata, Taku; Shimizu, Kasumi; Morita, Hiroshi; Inui, Madoka; Tagawa, Toshiro

2012-08-01

Phosphodiesterases (PDEs) are important regulators of signal transduction processes. Eleven PDE gene families (PDE1-11) have been identified and several PDE isoforms are selectively expressed in various cell types. PDE4 family members specifically hydrolyze cyclic AMP (cAMP). Four genes (PDE4A-D) are known to encode PDE4 enzymes, with additional diversity generated by the use of alternative mRNA splicing and the use of different promoters. While PDE4 selective inhibitors show therapeutic potential for treating major diseases such as asthma and chronic obstructive pulmonary disease, little is known concerning the role of PDE4 in malignant melanoma. In this study, we examined the role of PDE4 in mouse B16-F10 melanoma cells. In these cells, PDE4 activity was found to be ∼60% of total PDE activity. RT-PCR detected only PDE4B and PDE4D mRNA. Cell growth was inhibited by the cAMP analog, 8-bromo-cAMP, but not by the specific PDE4 inhibitors, rolipram and denbufylline, which increased intracellular cAMP concentrations. Finally, migration of the B16-F10 cells was inhibited by the PDE4 inhibitors and 8-bromo-cAMP, while migration was increased by a protein kinase A (PKA) inhibitor, PKI(14-22), and was not affected by 8-pCPT-2'-O-Me-cAMP, which is an analog of exchange protein activated by cAMP (Epac). The inhibitory effect of rolipram on migration was reversed by PKI(14-22). Based on these results, PDE4 appears to play an important role in the migration of B16-F10 cells, and therefore may be a novel target for the treatment of malignant melanoma.

Scalable Authenticated Tree Based Group Key Exchange for Ad-Hoc Groups

NASA Astrophysics Data System (ADS)

Desmedt, Yvo; Lange, Tanja; Burmester, Mike

Task-specific groups are often formed in an ad-hoc manner within large corporate structures, such as companies. Take the following typical scenario: A director decides to set up a task force group for some specific project. An order is passed down the hierarchy where it finally reaches a manager who selects some employees to form the group. The members should communicate in a secure way and for efficiency, a symmetric encryption system is chosen. To establish a joint secret key for the group, a group key exchange (GKE) protocol is used. We show how to use an existing Public Key Infrastructure (PKI) to achieve authenticated GKE by modifying the protocol and particularly by including signatures.

An eCK-Secure Authenticated Key Exchange Protocol without Random Oracles

NASA Astrophysics Data System (ADS)

Moriyama, Daisuke; Okamoto, Tatsuaki

This paper presents a (PKI-based) two-pass authenticated key exchange (AKE) protocol that is secure in the extended Canetti-Krawczyk (eCK) security model. The security of the proposed protocol is proven without random oracles (under three assumptions), and relies on no implementation techniques such as a trick by LaMacchia, Lauter and Mityagin (so-called the NAXOS trick). Since an AKE protocol that is eCK-secure under a NAXOS-like implementation trick will be no more eCK-secure if some realistic information leakage occurs through side-channel attacks, it has been an important open problem how to realize an eCK-secure AKE protocol without using the NAXOS tricks (and without random oracles).

Secure and Authenticated Data Communication in Wireless Sensor Networks.

PubMed

Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

2015-08-10

Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes.

Secure and Authenticated Data Communication in Wireless Sensor Networks

PubMed Central

Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

2015-01-01

Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes. PMID:26266413

Bacterial cellulose production by Gluconacetobacter sp. PKY5 in a rotary biofilm contactor.

PubMed

Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

2007-04-01

A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

Verification testing of the PKI collector at Sandia National Laboratories, Albuquerque, New Mexico

NASA Technical Reports Server (NTRS)

Hauger, J. S.; Pond, S. L.

1982-01-01

Verification testing of a solar collector was undertaken prior to its operation as part of an industrial process heat plant at Capitol Concrete Products in Topeka, Kansas. Testing was performed at a control plant installed at Sandia National Laboratory, Albuquerque, New Mexico (SNLA). Early results show that plant performance is even better than anticipated and far in excess of test criteria. Overall plant efficiencies of 65 to 80 percent were typical during hours of good insolation. A number of flaws and imperfections were detected during operability testing, the most important being a problem in elevation drive alignment due to a manufacturing error. All problems were corrected as they occurred and the plant, with over 40 hours of operation, is currently continuing operability testing in a wholly-automatic mode.

Verification testing of the PKI collector at Sandia National Laboratories, Albuquerque, New Mexico

NASA Astrophysics Data System (ADS)

Hauger, J. S.; Pond, S. L.

1982-07-01

Verification testing of a solar collector was undertaken prior to its operation as part of an industrial process heat plant at Capitol Concrete Products in Topeka, Kansas. Testing was performed at a control plant installed at Sandia National Laboratory, Albuquerque, New Mexico (SNLA). Early results show that plant performance is even better than anticipated and far in excess of test criteria. Overall plant efficiencies of 65 to 80 percent were typical during hours of good insolation. A number of flaws and imperfections were detected during operability testing, the most important being a problem in elevation drive alignment due to a manufacturing error. All problems were corrected as they occurred and the plant, with over 40 hours of operation, is currently continuing operability testing in a wholly-automatic mode.

Modeling, Simulation and Analysis of Public Key Infrastructure

NASA Technical Reports Server (NTRS)

Liu, Yuan-Kwei; Tuey, Richard; Ma, Paul (Technical Monitor)

1998-01-01

Security is an essential part of network communication. The advances in cryptography have provided solutions to many of the network security requirements. Public Key Infrastructure (PKI) is the foundation of the cryptography applications. The main objective of this research is to design a model to simulate a reliable, scalable, manageable, and high-performance public key infrastructure. We build a model to simulate the NASA public key infrastructure by using SimProcess and MatLab Software. The simulation is from top level all the way down to the computation needed for encryption, decryption, digital signature, and secure web server. The application of secure web server could be utilized in wireless communications. The results of the simulation are analyzed and confirmed by using queueing theory.

Architecture for networked electronic patient record systems.

PubMed

Takeda, H; Matsumura, Y; Kuwata, S; Nakano, H; Sakamoto, N; Yamamoto, R

2000-11-01

There have been two major approaches to the development of networked electronic patient record (EPR) architecture. One uses object-oriented methodologies for constructing the model, which include the GEHR project, Synapses, HL7 RIM and so on. The second approach uses document-oriented methodologies, as applied in examples of HL7 PRA. It is practically beneficial to take the advantages of both approaches and to add solution technologies for network security such as PKI. In recognition of the similarity with electronic commerce, a certificate authority as a trusted third party will be organised for establishing networked EPR system. This paper describes a Japanese functional model that has been developed, and proposes a document-object-oriented architecture, which is-compared with other existing models.

Partially Key Distribution with Public Key Cryptosystem Based on Error Control Codes

NASA Astrophysics Data System (ADS)

Tavallaei, Saeed Ebadi; Falahati, Abolfazl

Due to the low level of security in public key cryptosystems based on number theory, fundamental difficulties such as "key escrow" in Public Key Infrastructure (PKI) and a secure channel in ID-based cryptography, a new key distribution cryptosystem based on Error Control Codes (ECC) is proposed . This idea is done by some modification on McEliece cryptosystem. The security of ECC cryptosystem obtains from the NP-Completeness of block codes decoding. The capability of generating public keys with variable lengths which is suitable for different applications will be provided by using ECC. It seems that usage of these cryptosystems because of decreasing in the security of cryptosystems based on number theory and increasing the lengths of their keys would be unavoidable in future.

Making grandma's data secure: a security architecture for home telemedicine.

PubMed Central

Starren, J.; Sengupta, S.; Hripcsak, G.; Ring, G.; Klerer, R.; Shea, S.

2001-01-01

Home telemedicine presents special challenges for data security and privacy. Experience in the Informatics for Diabetes Education And Telemedicine (IDEATel) project has demonstrated that data security is not a one-size-fits-all problem. The IDEATel users include elderly patients in their homes, nurse case managers, physicians, and researchers. The project supports multiple computer systems that require a variety of user interactions, including: data entry, data review, patient education, videoconferencing, and electronic monitoring. To meet these various needs, a number of different of security solutions were utilized, including: UserID/Password, PKI certificates, time-based tokens, IP filtering, VPNs, symmetric and asymmetric encryption schemes, firewalls and dedicated connections. These were combined in different ways to meet the needs of each user groups. PMID:11825267

Reconsideration of F-layer seismic model in the south polar region

NASA Astrophysics Data System (ADS)

Ohtaki, T.; Kaneshima, S.

2017-12-01

Previously, we analyzed the seismic structure near the inner core boundary beneath Antarctica (Ohtaki et al., 2012). In the study, we determined the velocity of the lowermost outer core (F-layer) using amplitude ratio observations between the inner-core phase (PKIKP) and the inner-core grazing/diffracted phase (PKPbc/c-diff). Because the observations are not so sensitive to the F-layer structure, a constant velocity is assumed in the layer to simplify the model. The obtained model (SPR) has a flat velocity zone with a 75 km thick on the inner core boundary. With this F-layer structure and using travel times of these phases as well as the phase that reflects at the boundary, we determined the seismic structure of the inner core in the south polar region. However, a constant velocity layer is unrealistic, although it is reasonable assumption.Recently, we determined F-layer velocity structures more accurately using the combined observations of PKiKP-PKPbc differential travel times and of PKPbc/c-diff dispersion (Ohtaki et al., 2015, 2016). The former observation is sensitive to average velocity in the F-layer; the latter to velocity gradient in the layer. By analyzing these two observations together, we can determine the detailed velocity structure in the F-layer. The surveyed areas are beneath the Northeast Pacific and Australia. The seismic velocity models obtained are quite different between the two regions. Thus our results require laterally heterogeneous F-layer, and show that F-layer is more complicated than we ever imagined.Then there is one question; which structure is that of the south polar region close to? Unfortunately, the seismic waveforms that we analyzed in the previous study may not have quality high enough to analyze the PKiKP-PKPbc or PKPbc dispersion. However, it would be meaningful to reanalyze the amplitude data and reconsider the F-layer velocity there. And we also estimate how large slope of velocity can be acceptable for the F-layer velocity

Electronic Voting Protocol Using Identity-Based Cryptography.

PubMed

Gallegos-Garcia, Gina; Tapia-Recillas, Horacio

2015-01-01

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps.

Electronic Voting Protocol Using Identity-Based Cryptography

PubMed Central

Gallegos-Garcia, Gina; Tapia-Recillas, Horacio

2015-01-01

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps. PMID:26090515

Distributed Trust Management for Validating SLA Choreographies

NASA Astrophysics Data System (ADS)

Haq, Irfan Ul; Alnemr, Rehab; Paschke, Adrian; Schikuta, Erich; Boley, Harold; Meinel, Christoph

For business workflow automation in a service-enriched environment such as a grid or a cloud, services scattered across heterogeneous Virtual Organizations (VOs) can be aggregated in a producer-consumer manner, building hierarchical structures of added value. In order to preserve the supply chain, the Service Level Agreements (SLAs) corresponding to the underlying choreography of services should also be incrementally aggregated. This cross-VO hierarchical SLA aggregation requires validation, for which a distributed trust system becomes a prerequisite. Elaborating our previous work on rule-based SLA validation, we propose a hybrid distributed trust model. This new model is based on Public Key Infrastructure (PKI) and reputation-based trust systems. It helps preventing SLA violations by identifying violation-prone services at service selection stage and actively contributes in breach management at the time of penalty enforcement.

State of the Art in Trust and Reputation Models in P2P networks

NASA Astrophysics Data System (ADS)

Mármol, Félix Gómez; Pérez, Gregorio Martínez

Ensuring security in a distributed environment such as P2P networks is a critical issue nowadays. Nevertheless, it is in those kind of scenarios in which entities can enter or leave the community whenever they want, where traditional mboxsecurity schemes can not always be applied. Specifically, the use of a PKI (Public Key Infrastructure) may be unacceptable within highly distributed systems. Therefore, modeling concepts like trust and reputation may result very helpful and useful when trying to gain a certain level of security and confidence among inter-operating entities. Thus, this chapter presents a review of some of the most representative trust and reputation models for P2P networks, discussing their main characteristics and also their weaknesses and deficiencies. Open issues and challenges associated with them will be also covered.

Synthesis and conformational study of 3,4-carbocyclic bridged indole melatonin and serotonin analogues.

PubMed

Bedini, Annalida; Di Giacomo, Barbara; Gatti, Giuseppe; Spadoni, Gilberto

2005-08-01

Tetrahydrobenz[cd]indole, has been usually assumed to be a rigid scaffold of arylethylamines of pharmaceutical interest, such as melatonin and serotonin. A series of molecules containing this scaffold has been synthesized and their conformation in solution has been determined by 1H NMR. The values of the coupling constants show that the carbocycle fused with the indole ring is a mixture of the two conformers with substituent in equatorial or axial orientation. The molar fraction of the conformers appears to be sensibly affected by the bulkiness of the C-2 indole substituent. A pseudo-axial orientation of the C-3 alkylamido side chain is important for melatonin ligands to access the binding site and exhibit potent in vitro affinity, as illustrated for melatonin ligand 1 (pK(i)=9.32).

Developing Access Control Model of Web OLAP over Trusted and Collaborative Data Warehouses

NASA Astrophysics Data System (ADS)

Fugkeaw, Somchart; Mitrpanont, Jarernsri L.; Manpanpanich, Piyawit; Juntapremjitt, Sekpon

This paper proposes the design and development of Role- based Access Control (RBAC) model for the Single Sign-On (SSO) Web-OLAP query spanning over multiple data warehouses (DWs). The model is based on PKI Authentication and Privilege Management Infrastructure (PMI); it presents a binding model of RBAC authorization based on dimension privilege specified in attribute certificate (AC) and user identification. Particularly, the way of attribute mapping between DW user authentication and privilege of dimensional access is illustrated. In our approach, we apply the multi-agent system to automate flexible and effective management of user authentication, role delegation as well as system accountability. Finally, the paper culminates in the prototype system A-COLD (Access Control of web-OLAP over multiple DWs) that incorporates the OLAP features and authentication and authorization enforcement in the multi-user and multi-data warehouse environment.

Kinetics of acrylodan-labelled cAMP-dependent protein kinase catalytic subunit denaturation.

PubMed

Kivi, Rait; Loog, Mart; Jemth, Per; Järv, Jaak

2013-10-01

Fluorescence spectroscopy was used to study denaturation of cAMP-dependent protein kinase catalytic subunit labeled with an acrylodan moiety. The dye was covalently bound to a cystein residue introduced into the enzyme by replacement of arginine in position 326 in the native sequence, located near the enzyme active center. This labeling had no effect on catalytic activity of the enzyme, but provided possibility to monitor changes in protein structure through measuring the fluorescence spectrum of the dye, which is sensitive to changes in its environment. This method was used to monitor denaturation of the protein kinase catalytic subunit and study the kinetics of this process as well as influence of specific ligands on stability of the protein. Stabilization of the enzyme structure was observed in the presence of adenosine triphosphate, peptide substrate RRYSV and inhibitor peptide PKI[5-24].

Design and Development of a Web-Based DOD PKI Common Access Card (CAC) Instruction Tool

DTIC Science & Technology

2004-03-01

institute internal training programs…to help educate the appropriate personnel” (p. 269). This section indicates the need for training when...of “digital certificates” that provide for the integrity and authenticity of the user to public key value binding. • Though public keys can be...known as a digest) is a unique, fixed- length mathematical value that is determined by the content of the message and the ‘hashing’ algorithm used

76 FR 126 - Requirement for Commercial Users To Use Commercial Public Key Information (PKI) Certificate

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

..., SDDC will require all commercial accounts accessing transportation systems and applications to use a...: Department of Defense Instruction number 8520.2, 1 April 2004, 4.4 Joint Task Force-Global Network Operations..._8520.2.pdf ). Randy Moore, CAPT, USN, Division Chief, G6, Information Management/CIO. [FR Doc. 2010...

A dual-specificity isoform of the protein kinase inhibitor PKI produced by alternate gene splicing.

PubMed

Kumar, Priyadarsini; Walsh, Donal A

2002-03-15

We have previously shown that the protein kinase inhibitor beta (PKIbeta) form of the cAMP-dependent protein kinase inhibitor exists in multiple isoforms, some of which are specific inhibitors of the cAMP-dependent protein kinase, whereas others also inhibit the cGMP-dependent enzyme [Kumar, Van Patten and Walsh (1997), J. Biol. Chem. 272, 20011-20020]. We have now demonstrated that the switch from a cAMP-dependent protein kinase (PKA)-specific inhibitor to one with dual specificity arises as a consequence of alternate gene splicing. We have confirmed using bacterially produced pure protein that a single inhibitor species has dual specificity for both PKA and cGMP-dependent protein kinase (PKG), inhibiting each with very high and closely similar inhibitory potencies. The gene splicing converted a protein with 70 amino acids into one of 109 amino acids, and did not change the inhibitory potency to PKA, but changed it from a protein that had no detectable PKG inhibitory activity to one that now inhibited PKG in the nanomolar range.

Modulation of P-glycoprotein activity by novel synthetic curcumin derivatives in sensitive and multidrug-resistant T-cell acute lymphoblastic leukemia cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ooko, Edna

Background: Multidrug resistance (MDR) and drug transporter P-glycoprotein (P-gp) represent major obstacles in cancer chemotherapy. We investigated 19 synthetic curcumin derivatives in drug-sensitive acute lymphoblastic CCRF–CEM leukemia cells and their multidrug-resistant P-gp-overexpressing subline, CEM/ADR5000. Material and methods: Cytotoxicity was tested by resazurin assays. Doxorubicin uptake was assessed by flow cytometry. Binding modes of compounds to P-gp were analyzed by molecular docking. Chemical features responsible for bioactivity were studied by quantitative structure activity relationship (QSAR) analyses. A 7-descriptor QSAR model was correlated with doxorubicin uptake values, IC{sub 50} values and binding energies. Results: The compounds displayed IC{sub 50} values between 0.7more » ± 0.03 and 20.2 ± 0.25 μM. CEM/ADR5000 cells exhibited cross-resistance to 10 compounds, collateral sensitivity to three compounds and regular sensitivity to the remaining six curcumins. Molecular docking studies at the intra-channel transmembrane domain of human P-gp resulted in lowest binding energies ranging from − 9.00 ± 0.10 to − 6.20 ± 0.02 kcal/mol and pKi values from 0.24 ± 0.04 to 29.17 ± 0.88 μM. At the ATP-binding site of P-gp, lowest binding energies ranged from − 9.78 ± 0.17 to − 6.79 ± 0.01 kcal/mol and pKi values from 0.07 ± 0.02 to 0.03 ± 0.03 μM. CEM/ADR5000 cells accumulated approximately 4-fold less doxorubicin than CCRF–CEM cells. The control P-gp inhibitor, verapamil, partially increased doxorubicin uptake in CEM/ADR5000 cells. Six curcumins increased doxorubicin uptake in resistant cells or even exceeded uptake levels compared to sensitive one. QSAR yielded good activity prediction (R = 0.797 and R = 0.794 for training and test sets). Conclusion: Selected derivatives may serve to guide future design of novel P-gp inhibitors and collateral sensitive drugs to combat MDR. - Highlights: • Novel derivatives of curcumin in

Characterisation of the Novel Mixed Mu-NOP Peptide Ligand Dermorphin-N/OFQ (DeNo)

PubMed Central

Bird, Mark F.; Malfacini, Davide; Vezzi, Vanessa; Molinari, Paola; Micheli, Laura; Mannelli, Lorenzo Di Cesare; Ghelardini, Carla; Guerrini, Remo; Calò, Girolamo; Lambert, David G.

2016-01-01

Introduction Opioid receptors are currently classified as Mu (μ), Delta (δ), Kappa (κ) plus the opioid related nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP). Despite compelling evidence for interactions and benefits of targeting more than one receptor type in producing analgesia, clinical ligands are Mu agonists. In this study we have designed a Mu-NOP agonist named DeNo. The Mu agonist component is provided by dermorphin, a peptide isolated from the skin of Phyllomedusa frogs and the NOP component by the endogenous agonist N/OFQ. Methods We have assessed receptor binding profile of DeNo and compared with dermorphin and N/OFQ. In a series of functional screens we have assessed the ability to (i) increase Ca2+ in cells coexpressing recombinant receptors and a the chimeric protein Gαqi5, (ii) stimulate the binding of GTPγ[35S], (iii) inhibit cAMP formation, (iv) activate MAPKinase, (v) stimulate receptor-G protein and arrestin interaction using BRET, (vi) electrically stimulated guinea pig ileum (gpI) assay and (vii) ability to produce analgesia via the intrathecal route in rats. Results DeNo bound to Mu (pKi; 9.55) and NOP (pKi; 10.22) and with reasonable selectivity. This translated to increased Ca2+ in Gαqi5 expressing cells (pEC50 Mu 7.17; NOP 9.69), increased binding of GTPγ[35S] (pEC50 Mu 7.70; NOP 9.50) and receptor-G protein interaction in BRET (pEC50 Mu 8.01; NOP 9.02). cAMP formation was inhibited and arrestin was activated (pEC50 Mu 6.36; NOP 8.19). For MAPK DeNo activated p38 and ERK1/2 at Mu but only ERK1/2 at NOP. In the gpI DeNO inhibited electrically-evoked contractions (pEC50 8.63) that was sensitive to both Mu and NOP antagonists. DeNo was antinociceptive in rats. Conclusion Collectively these data validate the strategy used to create a novel bivalent Mu-NOP peptide agonist by combining dermorphin (Mu) and N/OFQ (NOP). This molecule behaves essentially as the parent compounds in vitro. In the antonocicoeptive assays employed in this

Inner Core Anisotropy in Attenuation

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.

2004-12-01

It is now well established that the compressional velocity in the Earth's inner core varies in both direction and geographic location. The compressional waves travel faster along the polar directions than along the equatorial directions. Such polar-equatorial difference is interpreted as a result of inner core anisotropy in velocity (with a magnitude of about 3%) and such anisotropy appears to be stronger in the ``western hemisphere" (180oW -40oE) than in the ``eastern hemisphere" (40oE-180oE). Along the equatorial paths, the compressional velocity also exhibits a hemispheric pattern with the eastern hemisphere being about 1% higher than the western hemisphere. Possible explanations for the causes of the velocity in anisotropy and the hemispheric difference in velocity along the equatorial paths include different geometric inclusions of melt or different alignments of iron crystals which are known to be anisotropic in velocities. Here, we report an observation of ubiquitous correlation between small (large) amplitude and fast (slow) travel time of the PKIKP waves sampling the top 300 km of the inner core. We study this correlation by jointly analyzing the differential travel times and amplitude ratios of the PKiKP-PKIKP and the PKPbc-PKIKP phases recorded by the Global Seismographic Network (1990-2001), various regional seismic networks (BANJO, BLSP, FREESIA, GEOFON, GEOSCOPE, Kazakhstan, Kyrgyz, MEDNET, and OHP), and several PASSCAL Networks deployed in Alaska and Antarctica (XE: 1999-2001, XF: 1995-1996, and YI: 1998-1999). Our dataset consists of 310 PKiKP-PKIKP and 240 PKPbc-PKIKP phases, selected from a total of more than 16,000 observations. PKIKP waves exhibit relatively smaller amplitudes for those sampling the eastern hemisphere along the equatorial paths and even smaller amplitudes for those sampling the polar paths in the western hemisphere. One simple explanation for the velocity-attenuation relation is that the inner core is anisotropic in attenuation

Pharmacological profile of DA-6886, a novel 5-HT4 receptor agonist to accelerate colonic motor activity in mice.

PubMed

Lee, Min Jung; Cho, Kang Hun; Park, Hyun Min; Sung, Hyun Jung; Choi, Sunghak; Im, Weonbin

2014-07-15

DA-6886, the gastrointestinal prokinetic benzamide derivative is a novel 5-HT4 receptor agonist being developed for the treatment of constipation-predominant irritable bowel syndrome (IBS-C). The purpose of this study was to characterize in vitro and in vivo pharmacological profile of DA-6886. We used various receptor binding assay, cAMP accumulation assay, organ bath experiment and colonic transit assay in normal and chemically constipated mice. DA-6886 exhibited high affinity and selectivity to human 5-HT4 receptor splice variants, with mean pKi of 7.1, 7.5, 7.9 for the human 5-HT4a, 5-HT4b and 5-HT4d, respectively. By contrast, DA-6886 did not show significant affinity for several receptors including dopamine D2 receptor, other 5-HT receptors except for 5-HT2B receptor (pKi value of 6.2). The affinity for 5-HT4 receptor was translated into functional agonist activity in Cos-7 cells expressing 5-HT4 receptor splice variants. Furthermore, DA-6886 induced relaxation of the rat oesophagus preparation (pEC50 value of 7.4) in a 5-HT4 receptor antagonist-sensitive manner. The evaluation of DA-6886 in CHO cells expressing hERG channels revealed that it inhibited hERG channel current with an pIC50 value of 4.3, indicating that the compound was 1000-fold more selective for the 5-HT4 receptor over hERG channels. In the normal ICR mice, oral administration of DA-6886 (0.4 and 2mg/kg) resulted in marked stimulation of colonic transit. Furthermore, in the loperamide-induced constipation mouse model, 2mg/kg of DA-6886 significantly improved the delay of colonic transit, similar to 10mg/kg of tegaserod. Taken together, DA-6886 is a highly potent and selective 5-HT4 receptor agonist to accelerate colonic transit in mice, which might be therapeutic agent having a favorable safety profile in the treatment of gastrointestinal motor disorders such as IBS-C and chronic constipation. Copyright © 2014 Elsevier B.V. All rights reserved.

Isoform-specific PKA dynamics revealed by dye-triggered aggregation and DAKAP1alpha-mediated localization in living cells.

PubMed

Martin, Brent R; Deerinck, Thomas J; Ellisman, Mark H; Taylor, Susan S; Tsien, Roger Y

2007-09-01

The tetracysteine sequence YRECCPGCCMWR fused to the N terminus of green fluorescent protein (GFP) self-aggregates upon biarsenical labeling in living cells or in vitro. Such dye-triggered aggregates form temperature-dependent morphologies and are dispersed by photobleaching. Fusion of the biarsenical aggregating GFP to the regulatory (R) or catalytic (C) subunit of PKA traps intact holoenzyme in compact fluorescent puncta upon biarsenical labeling. Contrary to the classical model of PKA activation, elevated cAMP does not allow RIalpha and Calpha to diffuse far apart unless the pseudosubstrate inhibitor PKI or locally concentrated substrate is coexpressed. However, RIIalpha releases Calpha upon elevated cAMP alone, dependent on autophosphorylation of the RIIalpha inhibitory domain. DAKAP1alpha overexpression induced R and C outer mitochondrial colocalization and showed similar regulation. Overall, effective separation of type I PKA is substrate dependent, whereas type II PKA dissociation relies on autophosphorylation.

A novel expression system for intracellular production and purification of recombinant affinity-tagged proteins in Aspergillus niger.

PubMed

Roth, Andreas H F J; Dersch, Petra

2010-03-01

A set of different integrative expression vectors for the intracellular production of recombinant proteins with or without affinity tag in Aspergillus niger was developed. Target genes can be expressed under the control of the highly efficient, constitutive pkiA promoter or the novel sucrose-inducible promoter of the beta-fructofuranosidase (sucA) gene of A. niger in the presence or absence of alternative carbon sources. All expression plasmids contain an identical multiple cloning sequence that allows parallel construction of N- or C-terminally His6- and StrepII-tagged versions of the target proteins. Production of two heterologous model proteins, the green fluorescence protein and the Thermobifida fusca hydrolase, proved the functionality of the vector system. Efficient production and easy detection of the target proteins as well as their fast purification by a one-step affinity chromatography, using the His6- or StrepII-tag sequence, was demonstrated.

Expecting the Unexpected: Towards Robust Credential Infrastructure

NASA Astrophysics Data System (ADS)

Xu, Shouhuai; Yung, Moti

Cryptographic credential infrastructures, such as Public key infrastructure (PKI), allow the building of trust relationships in electronic society and electronic commerce. At the center of credential infrastructures is the methodology of digital signatures. However, methods that assure that credentials and signed messages possess trustworthiness and longevity are not well understood, nor are they adequately addressed in both literature and practice. We believe that, as a basic engineering principle, these properties have to be built into the credential infrastructure rather than be treated as an after-thought since they are crucial to the long term success of this notion. In this paper we present a step in the direction of dealing with these issues. Specifically, we present the basic engineering reasoning as well as a model that helps understand (somewhat formally) the trustworthiness and longevity of digital signatures, and then we give basic mechanisms that help improve these notions.

Secure Remote Access Issues in a Control Center Environment

NASA Technical Reports Server (NTRS)

Pitts, Lee; McNair, Ann R. (Technical Monitor)

2002-01-01

The ISS finally reached an operational state and exists for local and remote users. Onboard payload systems are managed by the Huntsville Operations Support Center (HOSC). Users access HOSC systems by internet protocols in support of daily operations, preflight simulation, and test. In support of this diverse user community, a modem security architecture has been implemented. The architecture has evolved over time from an isolated but open system to a system which supports local and remote access to the ISS over broad geographic regions. This has been accomplished through the use of an evolved security strategy, PKI, and custom design. Through this paper, descriptions of the migration process and the lessons learned are presented. This will include product decision criteria, rationale, and the use of commodity products in the end architecture. This paper will also stress the need for interoperability of various products and the effects of seemingly insignificant details.

Secure Payload Access to the International Space Station

NASA Technical Reports Server (NTRS)

Pitts, R. Lee; Reid, Chris

2002-01-01

The ISS finally reached an operational state and exists for local and remote users. Onboard payload systems are managed by the Huntsville Operations Support Center (HOSC). Users access HOSC systems by internet protocols in support of daily operations, preflight simulation, and test. In support of this diverse user community, a modem security architecture has been implemented. The architecture has evolved over time from an isolated but open system to a system which supports local and remote access to the ISS over broad geographic regions. This has been accomplished through the use of an evolved security strategy, PKI, and custom design. Through this paper, descriptions of the migration process and the lessons learned are presented. This will include product decision criteria, rationale, and the use of commodity products in the end architecture. This paper will also stress the need for interoperability of various products and the effects of seemingly insignificant details.

Regional Variations in the Earth's upper inner core

NASA Astrophysics Data System (ADS)

Stroujkova, A.; Cormier, V. F.

2003-12-01

Strong regional variations in seismic velocity and attenuation have been observed in the uppermost layer of the inner core. Different studies suggest hemispherical differences within this transitional layer, with eastern hemisphere faster than the western (e.g. Garcia, 2002; Wen and Niu, 2002). The scale and the depth dependence of the heterogeneities are still in debate. In order to systematically study smaller scale heterogeneities we selected a data set of PKIKP and PKiKP phases with epicentral distances between 120\\deg and 140\\deg. The upper layer of the inner core was divided into `bins' and the seismograms were gathered into these bins according to the ray turning points. After correcting for source, site and propagation effects we stacked traces with close epicentral distance within each bin to improve signal-to-noise ratio. Finally we performed full 3D modeling of the obtained waveforms.

A Secure and Robust Object-Based Video Authentication System

NASA Astrophysics Data System (ADS)

He, Dajun; Sun, Qibin; Tian, Qi

2004-12-01

An object-based video authentication system, which combines watermarking, error correction coding (ECC), and digital signature techniques, is presented for protecting the authenticity between video objects and their associated backgrounds. In this system, a set of angular radial transformation (ART) coefficients is selected as the feature to represent the video object and the background, respectively. ECC and cryptographic hashing are applied to those selected coefficients to generate the robust authentication watermark. This content-based, semifragile watermark is then embedded into the objects frame by frame before MPEG4 coding. In watermark embedding and extraction, groups of discrete Fourier transform (DFT) coefficients are randomly selected, and their energy relationships are employed to hide and extract the watermark. The experimental results demonstrate that our system is robust to MPEG4 compression, object segmentation errors, and some common object-based video processing such as object translation, rotation, and scaling while securely preventing malicious object modifications. The proposed solution can be further incorporated into public key infrastructure (PKI).

ESnet authentication services and trust federations

NASA Astrophysics Data System (ADS)

Muruganantham, Dhivakaran; Helm, Mike; Genovese, Tony

2005-01-01

ESnet provides authentication services and trust federation support for SciDAC projects, collaboratories, and other distributed computing applications. The ESnet ATF team operates the DOEGrids Certificate Authority, available to all DOE Office of Science programs, plus several custom CAs, including one for the National Fusion Collaboratory and one for NERSC. The secure hardware and software environment developed to support CAs is suitable for supporting additional custom authentication and authorization applications that your program might require. Seamless, secure interoperation across organizational and international boundaries is vital to collaborative science. We are fostering the development of international PKI federations by founding the TAGPMA, the American regional PMA, and the worldwide IGTF Policy Management Authority (PMA), as well as participating in European and Asian regional PMAs. We are investigating and prototyping distributed authentication technology that will allow us to support the "roaming scientist" (distributed wireless via eduroam), as well as more secure authentication methods (one-time password tokens).

Anomalous top layer in the inner core beneath the eastern hemisphere

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.; Niu, F.

2003-12-01

Recent studies reported hemispheric variations in seismic velocity and attenuation in the top of the inner core. It, however, remains unclear how the inner core hemisphericity extends deep in the inner core. Here, we analyze PKPbc-PKIKP and PKiKP-PKIKP waveforms collected from the Global Seismographic Network (GSN), regional recordings from the German Regional Seismic Network (GRSN) and Graefenberg (GRF) sampling along the equatorial path (the ray path whose ray angle is larger than 35o from the Earth's rotation axis). The observed global and regional PKPbc-PKIKP differential traveltimes and PKIKP/PKPbc amplitude ratios suggest a simple W2 model (Wen/Niu:2002) in the western hemisphere with a constant velocity gradient of 0.049(km/sec)/100km and a Q value of 600 in the top 400 km of the inner core. In the eastern hemisphere, the data require a change of velocity gradient and Q value at about 235 km below the inner core boundary (ICB). Based on forward modeling, we construct radial velocity and attenuation models in the eastern hemisphere which can explain both the PKiKP-PKIKP and PKPbc-PKIKP observations. The inner core in the eastern hemisphere has a flat velocity gradient extending to about 235 km below the ICB. We test two solutions for the velocity models in the deeper portion of the inner core, with one having a first-order discontinuity at 235 km below the ICB with a velocity jump of 0.07(km/sec) followed by the PREM gradient, and the other having a gradual velocity transition with 0.1(km/sec)/100km gradient extended from 235 km to 375 km below the ICB followed by the PREM gradient. The observed traveltimes exclude the sharp discontinuity velocity model, as it predicts a kink in differential traveltimes at distance of 151o-152o which is not observed in the global and regional datasets. The observed PKIKP/PKPbc amplitude ratios can be best explained by a step function of attenuation with a Q value of 250 at the top 300 km and a Q value of 600 at 300-400 km

PCCEServer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perry, Marcia; Agarwal, Deb

2003-03-17

The PCCEServer application is a server that should be used in conjunction with the LBNLSecureMessaging user interface to enable secure synchronous and asynchronous messaging. It provides authentication and authorization services for members of a collaboration group via PKI/SSL and maintains an access control list. Members of collaboration groups using the LBNLSecureMessaging client must register identifying information. including usemame and password and an optional X.509 certificate, with the PCCEServer. This registration not only restricts access to instant messaging, but augments the LBNLSecureMessaging's IRC-based chat facility with persistence. Users register permanent unique user ids by which they are knowTl to other usersmore » in the system and create permanent venues intended for group conversations on a tong-term or continuous basis. In addition, the PCCEServer enhances instant messaging with presence and awareness information such as user availability, and it allows users to leave notes asynchronously for other users who are online or offline. Written in Java, it is a standalone application that can run on any platform that supports a Java Virtual Machine.« less

CernVM WebAPI - Controlling Virtual Machines from the Web

NASA Astrophysics Data System (ADS)

Charalampidis, I.; Berzano, D.; Blomer, J.; Buncic, P.; Ganis, G.; Meusel, R.; Segal, B.

2015-12-01

Lately, there is a trend in scientific projects to look for computing resources in the volunteering community. In addition, to reduce the development effort required to port the scientific software stack to all the known platforms, the use of Virtual Machines (VMs)u is becoming increasingly popular. Unfortunately their use further complicates the software installation and operation, restricting the volunteer audience to sufficiently expert people. CernVM WebAPI is a software solution addressing this specific case in a way that opens wide new application opportunities. It offers a very simple API for setting-up, controlling and interfacing with a VM instance in the users computer, while in the same time offloading the user from all the burden of downloading, installing and configuring the hypervisor. WebAPI comes with a lightweight javascript library that guides the user through the application installation process. Malicious usage is prohibited by offering a per-domain PKI validation mechanism. In this contribution we will overview this new technology, discuss its security features and examine some test cases where it is already in use.

Pharmacological evaluation of halogenated and non-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles as D(2) and 5-HT(2A) receptor ligands.

PubMed

Tomić, Mirko; Vasković, Djurdjica; Tovilović, Gordana; Andrić, Deana; Penjišević, Jelena; Kostić-Rajačić, Sladjana

2011-05-01

Five groups of previously synthesized and initially screened non-substituted and 4-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles were estimated for their in-vitro binding affinities at the rat D(2) , 5-HT(2A) , and α(1) -adrenergic receptors. Among all these compounds, 2-methoxyphenyl and 2-chlorophenyl piperazines demonstrate the highest affinities for the tested receptors. The effects of 4-halogenation of benzimidazoles reveal that substitution with bromine may greatly increase the affinity of the compounds for the studied receptors, while the effect of substitution with chlorine is less remarkable. Most of the tested components show 5-HT(2A)/D(2) pK(i) binding ratios slightly above or less than 1, while only 4-chloro-6-(2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)-1H-benzimidazole expresses an appropriate higher binding ratio (1.14), which was indicated for atypical neuroleptics. This compound exhibits a non-cataleptic action in rats and prevents d-amphetamine-induced hyperlocomotion in mice, which suggest its atypical antipsychotic potency. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activation of G-protein-coupled receptor 30 increases T-type calcium currents in trigeminal ganglion neurons via the cholera toxin-sensitive protein kinase A pathway.

PubMed

Yue, Jingxia; Zhang, Yi; Li, Xuemin; Gong, Shan; Tao, Jin; Jiang, Xinghong

2014-11-01

G protein-coupled receptor 30 (GPR30) is a seven transmembrane domain G protein coupled receptor. In our study, GPR30 expression was found in trigeminal ganglia (TG) in mice, detected by RT-PCR and western blotting. We examined the effects of GPR30 activation on T-type calcium channels using GPR30-specific compound 1 (G-1), a GPR30-selective agonist, in TG neurons and demonstrated that G-1 induced an increase in T-type calcium channel currents (T-currents) in TGs. Intracellular infusion of GDP-β-S and pre-treatment of the neurons with cholera toxin (CTX) blocked the effects of G-1, suggesting that the G(s)-protein was involved. Intracellular application of the protein kinase A (PKA) inhibitor PKI 6-22 or pretreatment of the neurons with H89 abolished G-1 -induced enhancement of T-currents in TG neurons. However, incubation with PKC inhibitor elicited no such effects. In conclusion, our study shows that activation of GPR30 by G-1 increases T-currents via the CTX-sensitive and PKA-dependent pathway.

Cellular and behavioural profile of the novel, selective neurokinin1 receptor antagonist, vestipitant: a comparison to other agents.

PubMed

Brocco, Mauricette; Dekeyne, Anne; Mannoury la Cour, Clotilde; Touzard, Manuelle; Girardon, Sylvie; Veiga, Sylvie; de Nanteuil, Guillaume; deJong, Trynke R; Olivier, Berend; Millan, Mark J

2008-10-01

This study characterized the novel neurokinin (NK)(1) antagonist, vestipitant, under clinical evaluation for treatment of anxiety and depression. Vestipitant possessed high affinity for human NK(1) receptors (pK(i), 9.4), and potently blocked Substance P-mediated phosphorylation of Extracellular-Regulated-Kinase. In vivo, it occupied central NK(1) receptors in gerbils (Inhibitory Dose(50), 0.11 mg/kg). At similar doses, it abrogated nociception elicited by formalin in gerbils, and blocked foot-tapping and locomotion elicited by the NK(1) agonist, GR73632, in gerbils and guinea pigs, respectively. Further, vestipitant attenuated fear-induced foot-tapping in gerbils, separation-induced distress-vocalizations in guinea pigs, marble-burying behaviour in mice, and displayed anxiolytic actions in Vogel conflict and fear-induced ultrasonic vocalization procedures in rats. These actions were mimicked by CP99,994, L733,060 and GR205,171 which acted stereoselectively vs its less active isomer, GR226,206. In conclusion, vestipitant is a potent NK(1) receptor antagonist: its actions support the utility of NK(1) receptor blockade in the alleviation of anxiety and, possibly, depression.

Virtual Application of Darul Arif Palace from Serdang Sultanate using Virtual Reality

NASA Astrophysics Data System (ADS)

Syahputra, M. F.; Annisa, T.; Rahmat, R. F.; Muchtar, M. A.

2017-01-01

Serdang Sultanate is one of Malay Sultanate in Sumatera Utara. In the 18th century, many Malay Aristocrats have developed in Sumatera Utara. Social revolution has happened in 1946, many sultanates were overthrown and member of PKI (Communist Party of Indonesia) did mass killing on members of the sultanate families. As the results of this incident, many cultural and historical heritage destroyed. The integration of heritage preservation and the digital technology has become recent trend. The digital technology is not only able to record, preserve detailed documents and information of heritage completely, but also effectively bring the value-added. In this research, polygonal modelling techniques from 3D modelling technology is used to reconstruct Darul Arif Palace of Serdang Sultanate. After modelling the palace, it will be combined with virtual reality technology to allow user to explore the palace and the environment around the palace. Virtual technology is simulation of real objects in virtual world. The results in this research is that virtual reality application can run using Head-Mounted Display.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, N.M.; Costall, B.; Egli, P.

The angiotensin converting enzyme (ACE) inhibitor ({sup 3}H)SQ29,852 identified a single high affinity recognition site (defined by 10.0 microM captopril) in the human temporal cortex (pKD 8.62 +/- 0.03; Bmax 248 +/- 24 fmol mg-1 protein, mean +/- S.E.M., n = 4). ACE inhibitors and thiorphan competed to a similar level for the ({sup 3}H)SQ29,852 binding site in the human temporal cortex with a rank order of affinity (pKi values mean +/- S.E.M., n = 3), lisinopril (9.49 +/- 0.02), captopril (9.16 +/- 0.08), SQ29,852 (8.58 +/- 0.04), epicaptopril (7.09 +/- 0.08), fosinopril (7.08 +/- 0.05) and thiorphan (6.40 +/-more » 0.04). Since this rank order of affinity is similar to the affinity of these compounds to inhibit brain ACE activity it is concluded that ({sup 3}H)SQ29,852 selectively labels the inhibitor recognition site of ACE in the human temporal cortex.« less

Structure-activity relationships studies on weakly basic N-arylsulfonylindoles with an antagonistic profile in the 5-HT6 receptor

NASA Astrophysics Data System (ADS)

Mella, Jaime; Villegas, Francisco; Morales-Verdejo, César; Lagos, Carlos F.; Recabarren-Gajardo, Gonzalo

2017-07-01

We recently reported a series of 39 weakly basic N-arylsulfonylindoles as novel 5-HT6 antagonists. Eight of the compounds exhibited moderate to high binding affinities, with 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol 16 showing the highest binding affinity (pKi = 7.87). Given these encouraging results and as a continuation of our research, we performed an extensive step-by-step search for the best 3D-QSAR model that allows us to rationally propose novel molecules with improved 5-HT6 affinity based on our previously reported series. A comparative molecular similarity indices analysis (CoMSIA) model built on a docking-based alignment was developed, wherein steric, electrostatic, hydrophobic and hydrogen bond properties are correlated with biological activity. The model was validated internally and externally (q2 = 0.721; r2pred = 0.938), and identified the sulfonyl and hydroxyl groups and the piperazine ring among the main regions of the molecules that can be modified to create new 5-HT6 antagonists.

Enhanced energy harvesting in commercial ferroelectric materials

NASA Astrophysics Data System (ADS)

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-04-01

Ferroelectric materials are used in a number of applications ranging from simple sensors and actuators to ferroelectric random access memories (FRAMs), transducers, health monitoring system and microelectronics. The multiphysical coupling ability possessed by these materials has been established to be useful for energy harvesting applications. However, conventional energy harvesting techniques employing ferroelectric materials possess low energy density. This has prevented the successful commercialization of ferroelectric based energy harvesting systems. In this context, the present study aims at proposing a novel approach for enhanced energy harvesting using commercially available ferroelectric materials. This technique was simulated to be used for two commercially available piezoelectric materials namely PKI-552 and APCI-840, soft and hard lead-zirconate-titanate (PZT) pervoskite ceramics, respectively. It was observed that a maximum energy density of 348 kJm-3cycle-1 can be obtained for cycle parameters of (0-1 ton compressive stress and 1-25 kV.cm-1 electric field) using APCI-840. The reported energy density is several hundred times larger than the maximum energy density reported in the literature for vibration harvesting systems.

Structural insights of a PI3K/mTOR dual inhibitor with the morpholino-triazine scaffold

NASA Astrophysics Data System (ADS)

Takeda, Takako; Wang, Yanli; Bryant, Stephen H.

2016-04-01

Stimulation of the PI3K/Akt/mTOR pathway, which controls cell proliferation and growth, is often observed in cancer cell. Inhibiting both PI3K and mTOR in this pathway can switch off Akt activation and hence, plays a powerful role for modulating this pathway. PKI-587, a drug containing the structure of morpholino-triazines, shows a dual and nano-molar inhibition activity and is currently in clinical trial. To provide an insight into the mechanism of this dual inhibition, pharmacophore and QSAR models were developed in this work using compounds based on the morpholino-triazines scaffold, followed by a docking study. Pharmacophore model suggested the mechanism of the inhibition of PI3Kα and mTOR by the compounds were mostly the same, which was supported by the docking study showing similar docking modes. The analysis also suggested the importance of the flat plane shape of the ligands, the space surrounding the ligands in the binding pocket, and the slight difference in the shape of the binding sites between PI3Kα and mTOR.

The Density Jump at the Inner Core Boundary in the Eastern and Western Hemispheres

NASA Astrophysics Data System (ADS)

Krasnoshchekov, D. N.; Ovtchinnikov, V. M.

2018-02-01

The results of analysis of more than 1300 new PKiKP/PcP amplitude ratios measured in Southeast Asia and South America at the epicentral distances of 3.2°-35.2° are presented. The density jump in the Eastern Hemisphere of the Earth's inner core (IC) is 0.3 g/cm3, and it is 0.9 g/cm3 in the Western one. Taking the large discrepancy in the obtained estimates into consideration, maintenance of such large lateral variations in the mosaic properties of the IC reflecting surface requires considerable variations in the thermodynamic parameters (mostly temperature) of the inner-outer core transition. However, if the observed asymmetry in the density jump distribution is of a global character, the data presented support the translation model of the IC dynamics. This model implies IC crystallization in the Western Hemisphere and melting in the Eastern one, not vice versa, as suggested by another geodynamic model based on thermochemical convection in the outer core and the thermal balance of the core-mantle system.

Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation

PubMed Central

Meduru, Harika; Wang, Yeng-Tseng; Tsai, Jeffrey J. P.; Chen, Yu-Ching

2016-01-01

Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes. PMID:27304951

Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation.

PubMed

Meduru, Harika; Wang, Yeng-Tseng; Tsai, Jeffrey J P; Chen, Yu-Ching

2016-06-13

Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes.

Chemical mechanism of D-amino acid oxidase from Rhodotorula gracilis: pH dependence of kinetic parameters.

PubMed Central

Ramón, F; Castillón, M; De La Mata, I; Acebal, C

1998-01-01

The variation of kinetic parameters of d-amino acid oxidase from Rhodotorula gracilis with pH was used to gain information about the chemical mechanism of the oxidation of D-amino acids catalysed by this flavoenzyme. d-Alanine was the substrate used. The pH dependence of Vmax and Vmax/Km for alanine as substrate showed that a group with a pK value of 6.26-7.95 (pK1) must be unprotonated and a group with a pK of 10.8-9.90 (pK2) must be protonated for activity. The lower pK value corresponded to a group on the enzyme involved in catalysis and whose protonation state was not important for binding. The higher pK value was assumed to be the amino group of the substrate. Profiles of pKi for D-aspartate as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 8.4 becomes unprotonated; this basic group was not detected in Vmax/Km profiles suggesting its involvement in binding of the beta-carboxylic group of the inhibitor. PMID:9461524

Genomic Imbalances Are Confined to Non-Proliferating Cells in Paediatric Patients with Acute Myeloid Leukaemia and a Normal or Incomplete Karyotype

PubMed Central

Ballabio, Erica; Regan, Regina; Garimberti, Elisa; Harbott, Jochen; Bradtke, Jutta; Teigler-Schlegel, Andrea; Biondi, Andrea; Cazzaniga, Giovanni; Giudici, Giovanni; Wainscoat, James S.; Boultwood, Jacqueline; Bridger, Joanna M.; Knight, Samantha J. L.; Tosi, Sabrina

2011-01-01

Leukaemia is often associated with genetic alterations such as translocations, amplifications and deletions, and recurrent chromosome abnormalities are used as markers of diagnostic and prognostic relevance. However, a proportion of acute myeloid leukaemia (AML) cases have an apparently normal karyotype despite comprehensive cytogenetic analysis. Based on conventional cytogenetic analysis of banded chromosomes, we selected a series of 23 paediatric patients with acute myeloid leukaemia and performed whole genome array comparative genome hybridization (aCGH) using DNA samples derived from the same patients. Imbalances involving large chromosomal regions or entire chromosomes were detected by aCGH in seven of the patients studied. Results were validated by fluorescence in situ hybridization (FISH) to both interphase nuclei and metaphase chromosomes using appropriate bacterial artificial chromosome (BAC) probes. The majority of these copy number alterations (CNAs) were confirmed by FISH and found to localize to the interphase rather than metaphase nuclei. Furthermore, the proliferative states of the cells analyzed by FISH were tested by immunofluorescence using an antibody against the proliferation marker pKi67. Interestingly, these experiments showed that, in the vast majority of cases, the changes appeared to be confined to interphase nuclei in a non-proliferative status. PMID:21694761

Expression and purification of isotopically labeled peptide inhibitors and substrates of cAMP-dependant protein kinase A for NMR analysis.

PubMed

Masterson, Larry R; Bortone, Nadia; Yu, Tao; Ha, Kim N; Gaffarogullari, Ece C; Nguyen, Oanh; Veglia, Gianluigi

2009-04-01

Extensive X-ray crystallographic studies carried out on the catalytic-subunit of protein kinase A (PKA-C) enabled the atomic characterization of inhibitor and/or substrate peptide analogues trapped at its active site. Yet, the structural and dynamic transitions of these peptides from the free to the bound state are missing. These conformational transitions are central to understanding molecular recognition and the enzymatic cycle. NMR spectroscopy allows one to study these phenomena under functionally relevant conditions. However, the amounts of isotopically labeled peptides required for this technique present prohibitive costs for solid-phase peptide synthesis. To enable NMR studies, we have optimized both expression and purification of isotopically enriched substrate/inhibitor peptides using a recombinant fusion protein system. Three of these peptides correspond to the cytoplasmic regions of the wild-type and lethal mutants of the membrane protein phospholamban, while the fourth peptide correspond to the binding epitope of the heat-stable protein kinase inhibitor (PKI(5-24)). The target peptides were fused to the maltose binding protein (MBP), which is further purified using a His(6) tag approach. This convenient protocol allows for the purification of milligram amounts of peptides necessary for NMR analysis.

Structure- and ligand-based structure-activity relationships for a series of inhibitors of aldolase.

PubMed

Ferreira, Leonardo G; Andricopulo, Adriano D

2012-12-01

Aldolase has emerged as a promising molecular target for the treatment of human African trypanosomiasis. Over the last years, due to the increasing number of patients infected with Trypanosoma brucei, there is an urgent need for new drugs to treat this neglected disease. In the present study, two-dimensional fragment-based quantitative-structure activity relationship (QSAR) models were generated for a series of inhibitors of aldolase. Through the application of leave-one-out and leave-many-out cross-validation procedures, significant correlation coefficients were obtained (r²=0.98 and q²=0.77) as an indication of the statistical internal and external consistency of the models. The best model was employed to predict pKi values for a series of test set compounds, and the predicted values were in good agreement with the experimental results, showing the power of the model for untested compounds. Moreover, structure-based molecular modeling studies were performed to investigate the binding mode of the inhibitors in the active site of the parasitic target enzyme. The structural and QSAR results provided useful molecular information for the design of new aldolase inhibitors within this structural class.

Late Pleistocene Environments of the Central Ukraine

NASA Astrophysics Data System (ADS)

Rousseau, Denis-Didier; Gerasimenko, Natalia; Matviischina, Zhanna; Kukla, George

2001-11-01

The Vyazivok loess sequence from the Dnieper Plain, Ukraine, documents regional environmental changes during the late Pleistocene and Holocene. Pedological and palynological analyses and low-field magnetic susceptibility document changes from dense temperate forest during the last interglacial maximum to open, harsh, loess-steppe during the latest Pleistocene. The Vyazivok section overlies hillwash derived from a lower Pleistocene terrace and consists of two stratified soil complexes (Kaydaky and Pryluky; marine isotope stage [MIS] 5 equivalent) separated by a layer of eolian dust (Tyasmyn silt). The lower soils in both complexes formed within forest. These soils are overlain by the Uday (MIS4) and Bug (MIS2) loess units, which are separated by boreal soils of the Vytachiv (MIS3) complex. The coldest conditions within the record occurred in the youngest loess. Holocene soils cap the Bug loess. The Vyazivok section shows remarkable similarities with other classical loess sequences in western Europe, the Czech Republic, and Austria. The Kaydaky, Pryluky, and Vytachiv deposits, correlate with the PKIII, PKII, and PKI soil complexes, respectively, of the Czech Republic. The Tyasmyn and Prylyky silt layers correspond to marker horizons from central Europe.

β-Agonist-mediated Relaxation of Airway Smooth Muscle Is Protein Kinase A-dependent*

PubMed Central

Morgan, Sarah J.; Deshpande, Deepak A.; Tiegs, Brian C.; Misior, Anna M.; Yan, Huandong; Hershfeld, Alena V.; Rich, Thomas C.; Panettieri, Reynold A.; An, Steven S.; Penn, Raymond B.

2014-01-01

Inhaled β-agonists are effective at reversing bronchoconstriction in asthma, but the mechanism by which they exert this effect is unclear and controversial. PKA is the historically accepted effector, although this assumption is made on the basis of associative and not direct evidence. Recent studies have asserted that exchange protein activated by cAMP (Epac), not PKA, mediates the relaxation of airway smooth muscle (ASM) observed with β-agonist treatment. This study aims to clarify the role of PKA in the prorelaxant effects of β-agonists on ASM. Inhibition of PKA activity via expression of the PKI and RevAB peptides results in increased β-agonist-mediated cAMP release, abolishes the inhibitory effect of isoproterenol on histamine-induced intracellular calcium flux, and significantly attenuates histamine-stimulated MLC-20 phosphorylation. Analyses of ASM cell and tissue contraction demonstrate that PKA inhibition eliminates most, if not all, β-agonist-mediated relaxation of contracted smooth muscle. Conversely, Epac knockdown had no effect on the regulation of contraction or procontractile signaling by isoproterenol. These findings suggest that PKA, not Epac, is the predominant and physiologically relevant effector through which β-agonists exert their relaxant effects. PMID:24973219

Distributed generation of shared RSA keys in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Liu, Yi-Liang; Huang, Qin; Shen, Ying

2005-12-01

Mobile Ad Hoc Networks is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner, independent of fixed physical infrastructure and centralized administrative infrastructure. However, the nature of Ad Hoc Networks makes them very vulnerable to security threats. Generation and distribution of shared keys for CA (Certification Authority) is challenging for security solution based on distributed PKI(Public-Key Infrastructure)/CA. The solutions that have been proposed in the literature and some related issues are discussed in this paper. The solution of a distributed generation of shared threshold RSA keys for CA is proposed in the present paper. During the process of creating an RSA private key share, every CA node only has its own private security. Distributed arithmetic is used to create the CA's private share locally, and that the requirement of centralized management institution is eliminated. Based on fully considering the Mobile Ad Hoc network's characteristic of self-organization, it avoids the security hidden trouble that comes by holding an all private security share of CA, with which the security and robustness of system is enhanced.

Glial interleukin-1β upregulates neuronal sodium channel 1.7 in trigeminal ganglion contributing to temporomandibular joint inflammatory hypernociception in rats.

PubMed

Zhang, Peng; Bi, Rui-Yun; Gan, Ye-Hua

2018-04-20

The proinflammatory cytokine interleukin-1β (IL-1β) drives pain by inducing the expression of inflammatory mediators; however, its ability to regulate sodium channel 1.7 (Nav1.7), a key driver of temporomandibular joint (TMJ) hypernociception, remains unknown. IL-1β induces cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). We previously showed that PGE2 upregulated trigeminal ganglionic Nav1.7 expression. Satellite glial cells (SGCs) involve in inflammatory pain through glial cytokines. Therefore, we explored here in the trigeminal ganglion (TG) whether IL-1β upregulated Nav1.7 expression and whether the IL-1β located in the SGCs upregulated Nav1.7 expression in the neurons contributing to TMJ inflammatory hypernociception. We treated rat TG explants with IL-1β with or without inhibitors, including NS398 for COX-2, PF-04418948 for EP2, and H89 and PKI-(6-22)-amide for protein kinase A (PKA), or with adenylate cyclase agonist forskolin, and used real-time PCR, Western blot, and immunohistofluorescence to determine the expressions or locations of Nav1.7, COX-2, cAMP response element-binding protein (CREB) phosphorylation, and IL-1β. We used chromatin immunoprecipitation to examine CREB binding to the Nav1.7 promoter. Finally, we microinjected IL-1β into the TGs or injected complete Freund's adjuvant into TMJs with or without previous microinjection of fluorocitrate, an inhibitor of SGCs activation, into the TGs, and evaluated nociception and gene expressions. Differences between groups were examined by one-way analysis of variance (ANOVA) or independent samples t test. IL-1β upregulated Nav1.7 mRNA and protein expressions in the TG explants, whereas NS398, PF-04418948, H89, or PKI-(6-22)-amide could all block this upregulation, and forskolin could also upregulate Nav1.7 mRNA and protein expressions. IL-1β enhanced CREB binding to the Nav1.7 promoter. Microinjection of IL-1β into the TGs or TMJ inflammation both induced hypernociception of TMJ region

Observation of core sensitive phases: Constraints on the velocity and attenuation profile in the vicinity of the inner-core boundary

NASA Astrophysics Data System (ADS)

Adam, J. M.-C.; Ibourichène, A.; Romanowicz, B.

2018-02-01

We measured more than three thousand differential travel-times and amplitude ratios of PKPBC , PKPBC-diff , PKPAB and PKPDF phases in the epicentral distance range [149°-171°], from high quality records of globally distributed broadband stations. In particular, this is the largest collection of differential measurements of PKPBC-diff compared to PKPDF , extending by ∼ 10 ° the epicentral distance range in which the diffracted PKPBC phase has been observed globally. We used forward modelling of waveforms using the Direct Solution Method combined with a grid-search approach to explore attenuation and P-velocity structure in the vicinity of the inner core boundary (ICB) that can explain our observations. We find that, in order to simultaneously explain differential travel times and amplitude ratios of PKPBC , PKPBC-diff with respect to PKPDF out to distances of 165 ° , while fitting PKPAB /PKPDF within measurement errors, it is necessary to introduce a ∼ 450km zone of reduced bulk quality factor (Qκ ∼ 600) at the base of the outer core, while Qκ is close to 200 in a layer ∼ 150km thick at the top of the inner core. Concurrently, the P-velocity in the last 100 km of the outer-core is on average about 0.5 % slower than in the reference model AK 135 , while it is about 0.5 % faster in the top 150 km of the inner-core, resulting in a P-velocity jump at the inner core boundary slightly higher than in model AK 135 . However, this model underpredicts PKPBC-diff /PKPDF amplitude ratios at distances larger than 165 ° . Reducing Qκ even further in the last 100 km of the outer-core (down to Qκ = 50) provides a good fit to these data but it is not compatible with measurements of PKiKP/PKPDF amplitude ratios in the distance range 120-140°. We also considered a previously assembled global collection of "M phase" data. The M phase is a large energy in the coda of the PKPBC and PKPBC-diff that is not predicted by current 1 D reference seismic models, but most likely

Comparative receptor mapping of serotoninergic 5-HT3 and 5-HT4 binding sites*

NASA Astrophysics Data System (ADS)

López-Rodríguez, María L.; Morcillo, María José; Benhamú, Bellinda; Rosado, María Luisa

1997-11-01

The clinical use of currently available drugs acting at the5-HT4 receptor has been hampered by their lack of selectivityover 5-HT3 binding sites. For this reason, there is considerableinterest in the medicinal chemistry of these serotonin receptor subtypes, andsignificant effort has been made towards the discovery of potent and selectiveligands. Computer-aided conformational analysis was used to characterizeserotoninergic 5-HT3 and 5-HT4 receptorrecognition. On the basis of the generally accepted model of the5-HT3 antagonist pharmacophore, we have performed a receptormapping of this receptor binding site, following the active analog approach(AAA) defined by Marshall. The receptor excluded volume was calculated as theunion of the van der Waals density maps of nine active ligands(pKi ≥ 8.9), superimposed in pharmacophoric conformations.Six inactive analogs (pKi < 7.0) were subsequently used todefine the essential volume, which in its turn can be used to define theregions of steric intolerance of the 5-HT3 receptor. Five activeligands (pKi ≥ 9.3) at 5-HT4 receptors wereused to construct an antagonist pharmacophore for this receptor, and todetermine its excluded volume by superimposition of pharmacophoricconformations. The volume defined by the superimposition of five inactive5-HT4 receptor analogs that possess the pharmacophoric elements(pKi ≤ 6.6) did not exceed the excluded volume calculated forthis receptor. In this case, the inactivity may be due to the lack of positiveinteraction of the amino moiety with a hypothetical hydrophobic pocket, whichwould interact with the voluminous substituents of the basic nitrogen ofactive ligands. The difference between the excluded volumes of both receptorshas confirmed that the main difference is indeed in the basic moiety. Thus,the 5-HT3 receptor can only accommodate small substituents inthe position of the nitrogen atom, whereas the 5-HT4 receptorrequires more voluminous groups. Also, the basic nitrogen is located at ca

The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation

PubMed Central

Lin, Tsung-Chieh; Su, Chia-Yi; Wu, Pei-Yu; Lai, Tsung-Ching; Pan, Wen-An; Jan, Yi-Hua; Chang, Yu-Chang; Yeh, Chi-Tai; Chen, Chi-Long; Ger, Luo-Ping; Chang, Hong-Tai; Yang, Chih-Jen; Huang, Ming-Shyan; Liu, Yu-Peng; Lin, Yuan-Feng; Shyy, John Y-J; Tsai, Ming-Daw; Hsiao, Michael

2016-01-01

Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation. DOI: http://dx.doi.org/10.7554/eLife.11288.001 PMID:26984280

β-Agonist-mediated relaxation of airway smooth muscle is protein kinase A-dependent.

PubMed

Morgan, Sarah J; Deshpande, Deepak A; Tiegs, Brian C; Misior, Anna M; Yan, Huandong; Hershfeld, Alena V; Rich, Thomas C; Panettieri, Reynold A; An, Steven S; Penn, Raymond B

2014-08-15

Inhaled β-agonists are effective at reversing bronchoconstriction in asthma, but the mechanism by which they exert this effect is unclear and controversial. PKA is the historically accepted effector, although this assumption is made on the basis of associative and not direct evidence. Recent studies have asserted that exchange protein activated by cAMP (Epac), not PKA, mediates the relaxation of airway smooth muscle (ASM) observed with β-agonist treatment. This study aims to clarify the role of PKA in the prorelaxant effects of β-agonists on ASM. Inhibition of PKA activity via expression of the PKI and RevAB peptides results in increased β-agonist-mediated cAMP release, abolishes the inhibitory effect of isoproterenol on histamine-induced intracellular calcium flux, and significantly attenuates histamine-stimulated MLC-20 phosphorylation. Analyses of ASM cell and tissue contraction demonstrate that PKA inhibition eliminates most, if not all, β-agonist-mediated relaxation of contracted smooth muscle. Conversely, Epac knockdown had no effect on the regulation of contraction or procontractile signaling by isoproterenol. These findings suggest that PKA, not Epac, is the predominant and physiologically relevant effector through which β-agonists exert their relaxant effects. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Complex Conjugated certificateless-based signcryption with differential integrated factor for secured message communication in mobile network

PubMed Central

Rajagopalan, S. P.

2017-01-01

Certificateless-based signcryption overcomes inherent shortcomings in traditional Public Key Infrastructure (PKI) and Key Escrow problem. It imparts efficient methods to design PKIs with public verifiability and cipher text authenticity with minimum dependency. As a classic primitive in public key cryptography, signcryption performs validity of cipher text without decryption by combining authentication, confidentiality, public verifiability and cipher text authenticity much more efficiently than the traditional approach. In this paper, we first define a security model for certificateless-based signcryption called, Complex Conjugate Differential Integrated Factor (CC-DIF) scheme by introducing complex conjugates through introduction of the security parameter and improving secured message distribution rate. However, both partial private key and secret value changes with respect to time. To overcome this weakness, a new certificateless-based signcryption scheme is proposed by setting the private key through Differential (Diff) Equation using an Integration Factor (DiffEIF), minimizing computational cost and communication overhead. The scheme is therefore said to be proven secure (i.e. improving the secured message distributing rate) against certificateless access control and signcryption-based scheme. In addition, compared with the three other existing schemes, the CC-DIF scheme has the least computational cost and communication overhead for secured message communication in mobile network. PMID:29040290

Aqueous Molecular Dynamics Simulations of the M. tuberculosis Enoyl-ACP Reductase-NADH System and Its Complex with a Substrate Mimic or Diphenyl Ethers Inhibitors

PubMed Central

da Silva Lima, Camilo Henrique; de Alencastro, Ricardo Bicca; Kaiser, Carlos Roland; de Souza, Marcus Vinícius Nora; Rodrigues, Carlos Rangel; Albuquerque, Magaly Girão

2015-01-01

Molecular dynamics (MD) simulations of 12 aqueous systems of the NADH-dependent enoyl-ACP reductase from Mycobacterium tuberculosis (InhA) were carried out for up to 20–40 ns using the GROMACS 4.5 package. Simulations of the holoenzyme, holoenzyme-substrate, and 10 holoenzyme-inhibitor complexes were conducted in order to gain more insight about the secondary structure motifs of the InhA substrate-binding pocket. We monitored the lifetime of the main intermolecular interactions: hydrogen bonds and hydrophobic contacts. Our MD simulations demonstrate the importance of evaluating the conformational changes that occur close to the active site of the enzyme-cofactor complex before and after binding of the ligand and the influence of the water molecules. Moreover, the protein-inhibitor total steric (ELJ) and electrostatic (EC) interaction energies, related to Gly96 and Tyr158, are able to explain 80% of the biological response variance according to the best linear equation, pKi = 7.772 − 0.1885 × Gly96 + 0.0517 × Tyr158 (R2 = 0.80; n = 10), where interactions with Gly96, mainly electrostatic, increase the biological response, while those with Tyr158 decrease. These results will help to understand the structure-activity relationships and to design new and more potent anti-TB drugs. PMID:26457706

Complex Conjugated certificateless-based signcryption with differential integrated factor for secured message communication in mobile network.

PubMed

Alagarsamy, Sumithra; Rajagopalan, S P

2017-01-01

Certificateless-based signcryption overcomes inherent shortcomings in traditional Public Key Infrastructure (PKI) and Key Escrow problem. It imparts efficient methods to design PKIs with public verifiability and cipher text authenticity with minimum dependency. As a classic primitive in public key cryptography, signcryption performs validity of cipher text without decryption by combining authentication, confidentiality, public verifiability and cipher text authenticity much more efficiently than the traditional approach. In this paper, we first define a security model for certificateless-based signcryption called, Complex Conjugate Differential Integrated Factor (CC-DIF) scheme by introducing complex conjugates through introduction of the security parameter and improving secured message distribution rate. However, both partial private key and secret value changes with respect to time. To overcome this weakness, a new certificateless-based signcryption scheme is proposed by setting the private key through Differential (Diff) Equation using an Integration Factor (DiffEIF), minimizing computational cost and communication overhead. The scheme is therefore said to be proven secure (i.e. improving the secured message distributing rate) against certificateless access control and signcryption-based scheme. In addition, compared with the three other existing schemes, the CC-DIF scheme has the least computational cost and communication overhead for secured message communication in mobile network.

Flip-flop of hydroxy fatty acids across the membrane as monitored by proton-sensitive microelectrodes.

PubMed

Pohl, Elena E; Voltchenko, Anna M; Rupprecht, Anne

2008-05-01

Hydroxyl group-containing fatty acids play an important role in anti-inflammatory action, neuroprotection, bactericide and anti-cancer defense. However, the mechanism of long-chain hydroxy fatty acids (HFA) transport across plasma membranes is still disputed. Two main hypotheses have been suggested: firstly, that protonated HFAs traverse across the membranes spontaneously and, secondly, that the transport is facilitated by proteinaceous carriers. Here, we demonstrate that the protonated HFA are able to move across planar lipid bilayers without protein assistance. This transport step is accompanied by the acidification of the buffer in receiving compartment and the pH augmentation in the donating compartment. The latter contained liposomes doped with HFA. As revealed by scanning pH-sensitive microelectrodes, the pH shift occurred only in the immediate vicinity of the membrane, while bulk pH remained unchanged. In concurrence with the theoretical model of weak acid transport, the pH value at maximum proton flux was almost equal to the pK of the studied HFA. Intrinsic pKi values were calculated from the electrophoretic mobilities of HFA-containing liposomes and were 5.4, 6.5, 6.9 and 6.3 for 2-hydroxyhexadecanoic, 16-hydroxyhexadecanoic, 12-hydroxydodecanoic and 9,10,16-trihydroxyhexadecanoic acids, respectively.

Adrenaline Stimulates Glucagon Secretion by Tpc2-Dependent Ca2+ Mobilization From Acidic Stores in Pancreatic α-Cells.

PubMed

Hamilton, Alexander; Zhang, Quan; Salehi, Albert; Willems, Mara; Knudsen, Jakob G; Ringgaard, Anna K; Chapman, Caroline E; Gonzalez-Alvarez, Alejandro; Surdo, Nicoletta C; Zaccolo, Manuela; Basco, Davide; Johnson, Paul R V; Ramracheya, Reshma; Rutter, Guy A; Galione, Antony; Rorsman, Patrik; Tarasov, Andrei I

2018-06-01

Adrenaline is a powerful stimulus of glucagon secretion. It acts by activation of β-adrenergic receptors, but the downstream mechanisms have only been partially elucidated. Here, we have examined the effects of adrenaline in mouse and human α-cells by a combination of electrophysiology, imaging of Ca 2+ and PKA activity, and hormone release measurements. We found that stimulation of glucagon secretion correlated with a PKA- and EPAC2-dependent (inhibited by PKI and ESI-05, respectively) elevation of [Ca 2+ ] i in α-cells, which occurred without stimulation of electrical activity and persisted in the absence of extracellular Ca 2+ but was sensitive to ryanodine, bafilomycin, and thapsigargin. Adrenaline also increased [Ca 2+ ] i in α-cells in human islets. Genetic or pharmacological inhibition of the Tpc2 channel (that mediates Ca 2+ release from acidic intracellular stores) abolished the stimulatory effect of adrenaline on glucagon secretion and reduced the elevation of [Ca 2+ ] i Furthermore, in Tpc2-deficient islets, ryanodine exerted no additive inhibitory effect. These data suggest that β-adrenergic stimulation of glucagon secretion is controlled by a hierarchy of [Ca 2+ ] i signaling in the α-cell that is initiated by cAMP-induced Tpc2-dependent Ca 2+ release from the acidic stores and further amplified by Ca 2+ -induced Ca 2+ release from the sarco/endoplasmic reticulum. © 2018 by the American Diabetes Association.

Simple group password-based authenticated key agreements for the integrated EPR information system.

PubMed

Lee, Tian-Fu; Chang, I-Pin; Wang, Ching-Cheng

2013-04-01

The security and privacy are important issues for electronic patient records (EPRs). The goal of EPRs is sharing the patients' medical histories such as the diagnosis records, reports and diagnosis image files among hospitals by the Internet. So the security issue for the integrated EPR information system is essential. That is, to ensure the information during transmission through by the Internet is secure and private. The group password-based authenticated key agreement (GPAKE) allows a group of users like doctors, nurses and patients to establish a common session key by using password authentication. Then the group of users can securely communicate by using this session key. Many approaches about GAPKE employ the public key infrastructure (PKI) in order to have higher security. However, it not only increases users' overheads and requires keeping an extra equipment for storing long-term secret keys, but also requires maintaining the public key system. This investigation presents a simple group password-based authenticated key agreement (SGPAKE) protocol for the integrated EPR information system. The proposed SGPAKE protocol does not require using the server or users' public keys. Each user only remembers his weak password shared with a trusted server, and then can obtain a common session key. Then all users can securely communicate by using this session key. The proposed SGPAKE protocol not only provides users with convince, but also has higher security.

Gate crashing arbuscular mycorrhizas: in vivo imaging shows the extensive colonization of both symbionts by Trichoderma atroviride.

PubMed

Lace, Beatrice; Genre, Andrea; Woo, Sheridan; Faccio, Antonella; Lorito, Matteo; Bonfante, Paola

2015-02-01

Plant growth-promoting fungi include strains of Trichoderma species that are used in biocontrol, and arbuscular mycorrhizal (AM) fungi, that enhance plant nutrition and stress resistance. The concurrent interaction of plants with these two groups of fungi affects crop performance but has only been occasionally studied so far. Using in vivo imaging of green fluorescent protein-tagged lines, we investigated the cellular interactions occurring between Trichoderma atroviride PKI1, Medicago truncatula and two Gigaspora species under in vitro culture conditions. Trichoderma atroviride did not activate symbiotic-like responses in the plant cells, such as nuclear calcium spiking or cytoplasmic aggregations at hyphal contact sites. Furthermore, T. atroviride parasitized G. gigantea and G. margarita hyphae through localized wall breaking and degradation - although this was not associated with significant chitin lysis nor the upregulation of two major chitinase genes. Trichoderma atroviride colonized broad areas of the root epidermis, in association with localized cell death. The infection of both symbionts was also observed when T. atroviride was applied to a pre-established AM symbiosis. We conclude that - although this triple interaction is known to improve plant growth in agricultural environments - in vitro culture demonstrate a particularly aggressive mycoparasitic and plant-colonizing behaviour of a biocontrol strain of Trichoderma. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

The relation between xyr1 overexpression in Trichoderma harzianum and sugarcane bagasse saccharification performance.

PubMed

da Silva Delabona, Priscila; Rodrigues, Gisele Nunes; Zubieta, Mariane Paludetti; Ramoni, Jonas; Codima, Carla Aloia; Lima, Deise Juliana; Farinas, Cristiane Sanchez; da Cruz Pradella, José Geraldo; Seiboth, Bernhard

2017-03-20

This work investigates the influence of the positive regulator XYR1 of Trichoderma harzianum on the production of cellulolytic enzymes, using sugarcane bagasse as carbon source. Constitutive expression of xyr1 was achieved under the control of the strong Trichoderma reesei pki1 promoter. Five clones with xyr1 overexpression achieved higher xyr1 expression and greater enzymatic productivity when cultivated under submerged fermentation, hence validating the genetic construction for T. harzianum. Clone 5 presented a relative expression of xyr1 26-fold higher than the parent strain and exhibited 66, 37, and 36% higher values for filter paper activity, xylanase activity, and β-glucosidase activity, respectively, during cultivation in a stirred-tank bioreactor. The overexpression of xyr1 in T. harzianum resulted in an enzymatic complex with significantly improved performance in sugarcane bagasse saccharification, with an enhancement of 25% in the first 24h. Our results also show that constitutive overexpression of xyr1 leads to the induction of several important players in biomass degradation at early (24h) and also late (48h) timepoints of inoculation. However, we also observed that the carbon catabolite repressor CRE1 was upregulated in xyr1 overexpression mutants. These findings demonstrate the feasibility of improving cellulase production by modifying regulator expression and suggest an attractive approach for increasing total cellulase productivity in T. harzianum. Copyright © 2017 Elsevier B.V. All rights reserved.

Network-based reading system for lung cancer screening CT

NASA Astrophysics Data System (ADS)

Fujino, Yuichi; Fujimura, Kaori; Nomura, Shin-ichiro; Kawashima, Harumi; Tsuchikawa, Megumu; Matsumoto, Toru; Nagao, Kei-ichi; Uruma, Takahiro; Yamamoto, Shinji; Takizawa, Hotaka; Kuroda, Chikazumi; Nakayama, Tomio

2006-03-01

This research aims to support chest computed tomography (CT) medical checkups to decrease the death rate by lung cancer. We have developed a remote cooperative reading system for lung cancer screening over the Internet, a secure transmission function, and a cooperative reading environment. It is called the Network-based Reading System. A telemedicine system involves many issues, such as network costs and data security if we use it over the Internet, which is an open network. In Japan, broadband access is widespread and its cost is the lowest in the world. We developed our system considering human machine interface and security. It consists of data entry terminals, a database server, a computer aided diagnosis (CAD) system, and some reading terminals. It uses a secure Digital Imaging and Communication in Medicine (DICOM) encrypting method and Public Key Infrastructure (PKI) based secure DICOM image data distribution. We carried out an experimental trial over the Japan Gigabit Network (JGN), which is the testbed for the Japanese next-generation network, and conducted verification experiments of secure screening image distribution, some kinds of data addition, and remote cooperative reading. We found that network bandwidth of about 1.5 Mbps enabled distribution of screening images and cooperative reading and that the encryption and image distribution methods we proposed were applicable to the encryption and distribution of general DICOM images via the Internet.

Protein Kinase Inhibitor γ reciprocally regulates osteoblast and adipocyte differentiation by downregulating Leukemia Inhibitory Factor

PubMed Central

Chen, Xin; Hausman, Bryan S.; Luo, Guangbin; Zhou, Guang; Murakami, Shunichi; Rubin, Janet; Greenfield, Edward M.

2013-01-01

The Protein Kinase Inhibitor (Pki) gene family inactivates nuclear PKA and terminates PKA-induced gene expression. We previously showed that Pkig is the primary family member expressed in osteoblasts and that Pkig knockdown increases the effects of parathyroid hormone and isoproterenol on PKA activation, gene expression, and inhibition of apoptosis. Here, we determined whether endogenous levels of Pkig regulate osteoblast differentiation. Pkig is the primary family member in MEFs, murine marrow-derived mesenchymal stem cells, and human mesenchymal stem cells. Pkig deletion increased forskolin-dependent nuclear PKA activation and gene expression and Pkig deletion or knockdown increased osteoblast differentiation. PKA signaling is known to stimulate adipogenesis; however, adipogenesis and osteogenesis are often reciprocally regulated. We found that the reciprocal regulation predominates over the direct effects of PKA since adipogenesis was decreased by Pkig deletion or knockdown. Pkig deletion or knockdown simultaneously increased osteogenesis and decreased adipogenesis in mixed osteogenic/adipogenic medium. Pkig deletion increased PKA-induced expression of Leukemia Inhibitory Factor (Lif) mRNA and LIF protein. LIF neutralizing antibodies inhibited the effects on osteogenesis and adipogenesis of either Pkig deletion in MEFs or PKIγ knockdown in both murine and human mesenchymal stem cells. Collectively, our results show that endogenous levels of Pkig reciprocally regulate osteoblast and adipocyte differentiation and that this reciprocal regulation is mediated in part by LIF. PMID:23963683

Identifying the binding mode of a molecular scaffold

NASA Astrophysics Data System (ADS)

Chema, Doron; Eren, Doron; Yayon, Avner; Goldblum, Amiram; Zaliani, Andrea

2004-01-01

We describe a method for docking of a scaffold-based series and present its advantages over docking of individual ligands, for determining the binding mode of a molecular scaffold in a binding site. The method has been applied to eight different scaffolds of protein kinase inhibitors (PKI). A single analog of each of these eight scaffolds was previously crystallized with different protein kinases. We have used FlexX to dock a set of molecules that share the same scaffold, rather than docking a single molecule. The main mode of binding is determined by the mode of binding of the largest cluster among the docked molecules that share a scaffold. Clustering is based on our `nearest single neighbor' method [J. Chem. Inf. Comput. Sci., 43 (2003) 208-217]. Additional criteria are applied in those cases in which more than one significant binding mode is found. Using the proposed method, most of the crystallographic binding modes of these scaffolds were reconstructed. Alternative modes, that have not been detected yet by experiments, could also be identified. The method was applied to predict the binding mode of an additional molecular scaffold that was not yet reported and the predicted binding mode has been found to be very similar to experimental results for a closely related scaffold. We suggest that this approach be used as a virtual screening tool for scaffold-based design processes.

Authentication of digital video evidence

NASA Astrophysics Data System (ADS)

Beser, Nicholas D.; Duerr, Thomas E.; Staisiunas, Gregory P.

2003-11-01

In response to a requirement from the United States Postal Inspection Service, the Technical Support Working Group tasked The Johns Hopkins University Applied Physics Laboratory (JHU/APL) to develop a technique tha will ensure the authenticity, or integrity, of digital video (DV). Verifiable integrity is needed if DV evidence is to withstand a challenge to its admissibility in court on the grounds that it can be easily edited. Specifically, the verification technique must detect additions, deletions, or modifications to DV and satisfy the two-part criteria pertaining to scientific evidence as articulated in Daubert et al. v. Merrell Dow Pharmaceuticals Inc., 43 F3d (9th Circuit, 1995). JHU/APL has developed a prototype digital video authenticator (DVA) that generates digital signatures based on public key cryptography at the frame level of the DV. Signature generation and recording is accomplished at the same time as DV is recorded by the camcorder. Throughput supports the consumer-grade camcorder data rate of 25 Mbps. The DVA software is implemented on a commercial laptop computer, which is connected to a commercial digital camcorder via the IEEE-1394 serial interface. A security token provides agent identification and the interface to the public key infrastructure (PKI) that is needed for management of the public keys central to DV integrity verification.

Network Computing Infrastructure to Share Tools and Data in Global Nuclear Energy Partnership

NASA Astrophysics Data System (ADS)

Kim, Guehee; Suzuki, Yoshio; Teshima, Naoya

CCSE/JAEA (Center for Computational Science and e-Systems/Japan Atomic Energy Agency) integrated a prototype system of a network computing infrastructure for sharing tools and data to support the U.S. and Japan collaboration in GNEP (Global Nuclear Energy Partnership). We focused on three technical issues to apply our information process infrastructure, which are accessibility, security, and usability. In designing the prototype system, we integrated and improved both network and Web technologies. For the accessibility issue, we adopted SSL-VPN (Security Socket Layer-Virtual Private Network) technology for the access beyond firewalls. For the security issue, we developed an authentication gateway based on the PKI (Public Key Infrastructure) authentication mechanism to strengthen the security. Also, we set fine access control policy to shared tools and data and used shared key based encryption method to protect tools and data against leakage to third parties. For the usability issue, we chose Web browsers as user interface and developed Web application to provide functions to support sharing tools and data. By using WebDAV (Web-based Distributed Authoring and Versioning) function, users can manipulate shared tools and data through the Windows-like folder environment. We implemented the prototype system in Grid infrastructure for atomic energy research: AEGIS (Atomic Energy Grid Infrastructure) developed by CCSE/JAEA. The prototype system was applied for the trial use in the first period of GNEP.

PKIX Certificate Status in Hybrid MANETs

NASA Astrophysics Data System (ADS)

Muñoz, Jose L.; Esparza, Oscar; Gañán, Carlos; Parra-Arnau, Javier

Certificate status validation is a hard problem in general but it is particularly complex in Mobile Ad-hoc Networks (MANETs) because we require solutions to manage both the lack of fixed infrastructure inside the MANET and the possible absence of connectivity to trusted authorities when the certification validation has to be performed. In this sense, certificate acquisition is usually assumed as an initialization phase. However, certificate validation is a critical operation since the node needs to check the validity of certificates in real-time, that is, when a particular certificate is going to be used. In such MANET environments, it may happen that the node is placed in a part of the network that is disconnected from the source of status data at the moment the status checking is required. Proposals in the literature suggest the use of caching mechanisms so that the node itself or a neighbour node has some status checking material (typically on-line status responses or lists of revoked certificates). However, to the best of our knowledge the only criterion to evaluate the cached (obsolete) material is the time. In this paper, we analyse how to deploy a certificate status checking PKI service for hybrid MANET and we propose a new criterion based on risk to evaluate cached status data that is much more appropriate and absolute than time because it takes into account the revocation process.

Chirality measures of α-amino acids.

PubMed

Jamróz, Michał H; Rode, Joanna E; Ostrowski, Sławomir; Lipiński, Piotr F J; Dobrowolski, Jan Cz

2012-06-25

To measure molecular chirality, the molecule is treated as a finite set of points in the Euclidean R(3) space supplemented by k properties, p(1)((i)), p(2)((i)), ..., p(k)((i)) assigned to the ith atom, which constitute a point in the Property P(k) space. Chirality measures are described as the distance between a molecule and its mirror image minimized over all its arbitrary orientation-preserving isometries in the R(3) × P(k) Cartesian product space. Following this formalism, different chirality measures can be estimated by taking into consideration different sets of atomic properties. Here, for α-amino acid zwitterionic structures taken from the Cambridge Structural Database and for all 1684 neutral conformers of 19 biogenic α-amino acid molecules, except glycine and cystine, found at the B3LYP/6-31G** level, chirality measures have been calculated by a CHIMEA program written in this project. It is demonstrated that there is a significant correlation between the measures determined for the α-amino acid zwitterions in crystals and the neutral forms in the gas phase. Performance of the studied chirality measures with changes of the basis set and computation method was also checked. An exemplary quantitative structure–activity relationship (QSAR) application of the chirality measures was presented by an introductory model for the benchmark Cramer data set of steroidal ligands of the sex-hormone binding globulin.

[Advenella kashmirensis subsp. methylica PK1, a facultative methylotroph from carex rhizosphere].

PubMed

Poroshina, M N; Doronina, N V; Kaparullina, E N; Trotsenko, Iu A

2015-01-01

A strain (PK1) of facultative methylobacteria growing on methanol as a carbon and energy source was isolated from carex rhizosphere (Pamukkale National Park, Turkey). The cells were nonmotile gram-negative rods propagating by binary fission. The organism was a strict anaerobe, oxidase- and catalase-positive. Optimal growth occurred at 29°C, pH 8.0-8.5, and 0.5% NaCl; no growth occurred at 2% NaCl. The organism used the ribulose bisphosphate pathway of C1 assimilation. Predominant fatty acids were 11-octodecenoic (18:1ω7) and cis-hexadecenoic (16:1ω7c). Phosphatidylethanolamine and diphosphatidylglycerol were the dominant phospholipids. Q8 was the main ubiquinone. DNA G+C content was 55.4 mol % (mp). Sequencing of the 16S rRNA gene revealed that strain PK1 belonged to the genus Advenella with 98.8 and 99.2% similarity to the type strains A. incenata CCUG 45225T and A. kashmirensis WT001T, respectively. DNA-DNA homology of strain PK1 and A. kashmirensis WT001T was 70%. While MALDI analysis confirmed their close clusterization, RAPD analysis revealed the differences between strain PKI and other Advenella strains. Based on its geno- and phenotypic properties, the isolate PK1 was classified as A. kashmirensis subsp. methylica PK1 (VKM-B 2850 = DSM 27514), the first known methylotroph of the genus Advenella.

Structural characterization of ribosome recruitment and translocation by type IV IRES.

PubMed

Murray, Jason; Savva, Christos G; Shin, Byung-Sik; Dever, Thomas E; Ramakrishnan, V; Fernández, Israel S

2016-05-09

Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts tvhe otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation.

Isolation and characterization at cholinergic nicotinic receptors of a neurotoxin from the venom of the Acanthophis sp. Seram death adder.

PubMed

Wickramaratna, Janith C; Fry, Bryan G; Loiacono, Richard E; Aguilar, Marie-Isabel; Alewood, Paul F; Hodgson, Wayne C

2004-07-15

The present study describes the isolation of the first neurotoxin (acantoxin IVa) from Acanthophis sp. Seram death adder venom and an examination of its activity at nicotinic acetylcholine receptor (nAChR) subtypes. Acantoxin IVa (MW 6815; 0.1-1.0 microM) caused concentration-dependent inhibition of indirect twitches (0.1 Hz, 0.2 ms, supramaximal V) and inhibited contractile responses to exogenous nicotinic agonists in the chick biventer cervicis nerve-muscle, confirming that this toxin is a postsynaptic neurotoxin. Acantoxin IVa (1-10 nM) caused pseudo-irreversible antagonism at skeletal muscle nAChR with an estimated pA2 of 8.36+/-0.17. Acantoxin IVa was approximately two-fold less potent than the long-chain (Type II) neurotoxin, alpha-bungarotoxin. With a pKi value of 4.48, acantoxin IVa was approximately 25,000 times less potent than alpha-bungarotoxin at alpha7-type neuronal nAChR. However, in contrast to alpha-bungarotoxin, acantoxin IVa completely inhibited specific [3H]-methyllycaconitine (MLA) binding in rat hippocampus homogenate. Acantoxin IVa had no activity at ganglionic nAChR, alpha4beta2 subtype neuronal nAChR or cytisine-resistant [3H]-epibatidine binding sites. While long-chain neurotoxin resistant [3H]-MLA binding in hippocampus homogenate requires further investigation, we have shown that a short-chain (Type I) neurotoxin is capable of fully inhibiting specific [3H]-MLA binding.

Structural characterization of ribosome recruitment and translocation by type IV IRES

PubMed Central

Murray, Jason; Savva, Christos G; Shin, Byung-Sik; Dever, Thomas E; Ramakrishnan, V; Fernández, Israel S

2016-01-01

Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts the otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation. DOI: http://dx.doi.org/10.7554/eLife.13567.001 PMID:27159451

Extending key sharing: how to generate a key tightly coupled to a network security policy

NASA Astrophysics Data System (ADS)

Kazantzidis, Matheos

2006-04-01

Current state of the art security policy technologies, besides the small scale limitation and largely manual nature of accompanied management methods, are lacking a) in real-timeliness of policy implementation and b) vulnerabilities and inflexibility stemming from the centralized policy decision making; even if, for example, a policy description or access control database is distributed, the actual decision is often a centralized action and forms a system single point of failure. In this paper we are presenting a new fundamental concept that allows implement a security policy by a systematic and efficient key distribution procedure. Specifically, we extend the polynomial Shamir key splitting. According to this, a global key is split into n parts, any k of which can re-construct the original key. In this paper we present a method that instead of having "any k parts" be able to re-construct the original key, the latter can only be reconstructed if keys are combined as any access control policy describes. This leads into an easily deployable key generation procedure that results a single key per entity that "knows" its role in the specific access control policy from which it was derived. The system is considered efficient as it may be used to avoid expensive PKI operations or pairwise key distributions as well as provides superior security due to its distributed nature, the fact that the key is tightly coupled to the policy, and that policy change may be implemented easier and faster.

Prediction of N-Methyl-D-Aspartate Receptor GluN1-Ligand Binding Affinity by a Novel SVM-Pose/SVM-Score Combinatorial Ensemble Docking Scheme

NASA Astrophysics Data System (ADS)

Leong, Max K.; Syu, Ren-Guei; Ding, Yi-Lung; Weng, Ching-Feng

2017-01-01

The glycine-binding site of the N-methyl-D-aspartate receptor (NMDAR) subunit GluN1 is a potential pharmacological target for neurodegenerative disorders. A novel combinatorial ensemble docking scheme using ligand and protein conformation ensembles and customized support vector machine (SVM)-based models to select the docked pose and to predict the docking score was generated for predicting the NMDAR GluN1-ligand binding affinity. The predicted root mean square deviation (RMSD) values in pose by SVM-Pose models were found to be in good agreement with the observed values (n = 30, r2 = 0.928-0.988,  = 0.894-0.954, RMSE = 0.002-0.412, s = 0.001-0.214), and the predicted pKi values by SVM-Score were found to be in good agreement with the observed values for the training samples (n = 24, r2 = 0.967,  = 0.899, RMSE = 0.295, s = 0.170) and test samples (n = 13, q2 = 0.894, RMSE = 0.437, s = 0.202). When subjected to various statistical validations, the developed SVM-Pose and SVM-Score models consistently met the most stringent criteria. A mock test asserted the predictivity of this novel docking scheme. Collectively, this accurate novel combinatorial ensemble docking scheme can be used to predict the NMDAR GluN1-ligand binding affinity for facilitating drug discovery.

GEMSS: privacy and security for a medical Grid.

PubMed

Middleton, S E; Herveg, J A M; Crazzolara, F; Marvin, D; Poullet, Y

2005-01-01

The GEMSS project is developing a secure Grid infrastructure through which six medical simulations services can be invoked. We examine the legal and security framework within which GEMSS operates. We provide a legal qualification to the operations performed upon patient data, in view of EU directive 95/46, when using medical applications on the GEMSS Grid. We identify appropriate measures to ensure security and describe the legal rationale behind our choice of security technology. Our legal analysis demonstrates there must be an identified controller (typically a hospital) of patient data. The controller must then choose a processor (in this context a Grid service provider) that provides sufficient guarantees with respect to the security of their technical and organizational data processing procedures. These guarantees must ensure a level of security appropriate to the risks, with due regard to the state of the art and the cost of their implementation. Our security solutions are based on a public key infrastructure (PKI), transport level security and end-to-end security mechanisms in line with the web service (WS Security, WS Trust and SecureConversation) security specifications. The GEMSS infrastructure ensures a degree of protection of patient data that is appropriate for the health care sector, and is in line with the European directives. We hope that GEMSS will become synonymous with high security data processing, providing a framework by which GEMSS service providers can provide the security guarantees required by hospitals with regard to the processing of patient data.

Watermarking protocols for authentication and ownership protection based on timestamps and holograms

NASA Astrophysics Data System (ADS)

Dittmann, Jana; Steinebach, Martin; Croce Ferri, Lucilla

2002-04-01

Digital watermarking has become an accepted technology for enabling multimedia protection schemes. One problem here is the security of these schemes. Without a suitable framework, watermarks can be replaced and manipulated. We discuss different protocols providing security against rightful ownership attacks and other fraud attempts. We compare the characteristics of existing protocols for different media like direct embedding or seed based and required attributes of the watermarking technology like robustness or payload. We introduce two new media independent protocol schemes for rightful ownership authentication. With the first scheme we ensure security of digital watermarks used for ownership protection with a combination of two watermarks: first watermark of the copyright holder and a second watermark from a Trusted Third Party (TTP). It is based on hologram embedding and the watermark consists of e.g. a company logo. As an example we use digital images and specify the properties of the embedded additional security information. We identify components necessary for the security protocol like timestamp, PKI and cryptographic algorithms. The second scheme is used for authentication. It is designed for invertible watermarking applications which require high data integrity. We combine digital signature schemes and digital watermarking to provide a public verifiable integrity. The original data can only be reproduced with a secret key. Both approaches provide solutions for copyright and authentication watermarking and are introduced for image data but can be easily adopted for video and audio data as well.

x509-free access to WLCG resources

NASA Astrophysics Data System (ADS)

Short, H.; Manzi, A.; De Notaris, V.; Keeble, O.; Kiryanov, A.; Mikkonen, H.; Tedesco, P.; Wartel, R.

2017-10-01

Access to WLCG resources is authenticated using an x509 and PKI infrastructure. Even though HEP users have always been exposed to certificates directly, the development of modern Web Applications by the LHC experiments calls for simplified authentication processes keeping the underlying software unmodified. In this work we will show a solution with the goal of providing access to WLCG resources using the user’s home organisations credentials, without the need for user-acquired x509 certificates. In particular, we focus on identity providers within eduGAIN, which interconnects research and education organisations worldwide, and enables the trustworthy exchange of identity-related information. eduGAIN has been integrated at CERN in the SSO infrastructure so that users can authenticate without the need of a CERN account. This solution achieves x509-free access to Grid resources with the help of two services: STS and an online CA. The STS (Security Token Service) allows credential translation from the SAML2 format used by Identity Federations to the VOMS-enabled x509 used by most of the Grid. The IOTA CA (Identifier-Only Trust Assurance Certification Authority) is responsible for the automatic issuing of short-lived x509 certificates. The IOTA CA deployed at CERN has been accepted by EUGridPMA as the CERN LCG IOTA CA, included in the IGTF trust anchor distribution and installed by the sites in WLCG. We will also describe the first pilot projects which are integrating the solution.

Stargate GTM: Bridging Descriptor and Activity Spaces.

PubMed

Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

2015-11-23

Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.

Scattering - a probe to Earth's small scale structure

NASA Astrophysics Data System (ADS)

Rost, S.; Earle, P.

2009-05-01

Much of the short-period teleseismic wavefield shows strong evidence for scattered waves in extended codas trailing the main arrivals predicted by ray theory. This energy mainly originates from high-frequency body waves interacting with fine-scale volumetric heterogeneities in the Earth. Studies of this energy revealed much of what we know about Earth's structure at scale lengths around 10 km throughout the Earth from crust to core. From these data we can gain important information about the mineral-physical and geochemical constitution of the Earth that is inaccessible to many other seismic imaging techniques. Previous studies used scattered energy related to PKP, PKiKP, and Pdiff to identify and map the small-scale structure of the mantle and core. We will present observations related to the core phases PKKP and P'P' to study fine-scale mantle heterogeneities. These phases are maximum travel-time phases with respect to perturbations at their reflection points. This allows observation of the scattered energy as precursors to the main phase avoiding common problems with traditional coda phases which arrive after the main pulse. The precursory arrival of the scattered energy allows the separation between deep Earth and crustal contributions to the scattered wavefield for certain source-receiver configurations. Using the information from these scattered phases we identify regions of the mantle that shows increased scattering potential likely linked to larger scale mantle structure identified in seismic tomography and geodynamical models.

Behavioral stress accelerates prostate cancer development in mice

PubMed Central

Hassan, Sazzad; Karpova, Yelena; Baiz, Daniele; Yancey, Dana; Pullikuth, Ashok; Flores, Anabel; Register, Thomas; Cline, J. Mark; D’Agostino, Ralph; Danial, Nika; Datta, Sandeep Robert; Kulik, George

2013-01-01

Prostate cancer patients have increased levels of stress and anxiety. Conversely, men who take beta blockers, which interfere with signaling from the stress hormones adrenaline and noradrenaline, have a lower incidence of prostate cancer; however, the mechanisms underlying stress–prostate cancer interactions are unknown. Here, we report that stress promotes prostate carcinogenesis in mice in an adrenaline-dependent manner. Behavioral stress inhibited apoptosis and delayed prostate tumor involution both in phosphatase and tensin homolog–deficient (PTEN-deficient) prostate cancer xenografts treated with PI3K inhibitor and in prostate tumors of mice with prostate-restricted expression of c-MYC (Hi-Myc mice) subjected to androgen ablation therapy with bicalutamide. Additionally, stress accelerated prostate cancer development in Hi-Myc mice. The effects of stress were prevented by treatment with the selective β2-adrenergic receptor (ADRB2) antagonist ICI118,551 or by inducible expression of PKA inhibitor (PKI) or of BCL2-associated death promoter (BAD) with a mutated PKA phosphorylation site (BADS112A) in xenograft tumors. Effects of stress were also blocked in Hi-Myc mice expressing phosphorylation-deficient BAD (BAD3SA). These results demonstrate interactions between prostate tumors and the psychosocial environment mediated by activation of an adrenaline/ADRB2/PKA/BAD antiapoptotic signaling pathway. Our findings could be used to identify prostate cancer patients who could benefit from stress reduction or from pharmacological inhibition of stress-induced signaling. PMID:23348742

Specific labelling of serotonin 5-HT(1B) receptors in rat frontal cortex with the novel, phenylpiperazine derivative, [3H]GR125,743. A pharmacological characterization.

PubMed

Millan, M J; Newman-Tancredi, A; Lochon, S; Touzard, M; Aubry, S; Audinot, V

2002-04-01

Although several tritiated agonists have been used for radiolabelling serotonin (5-hydroxytryptamine, 5-HT)(1B) receptors in rats, data with a selective, radiolabelled antagonist have not been presented. Inasmuch as [3H]GR125,743 specifically labels cloned, human and native guinea pig 5-HT(1B) receptors and has been employed for characterization of cerebral 5-HT(1B) receptor in the latter species [Eur. J. Pharmacol. 327 (1997) 247.], the present study evaluated its utility for characterization of native, cerebral 5-HT(1B) sites in the rat. In homogenates of frontal cortex, [3H]GR125,743 (0.8 nM) showed rapid association (t(1/2)=3.4 min), >90% specific binding and high affinity (K(d)=0.6 nM) for a homogeneous population of receptors with a density (B(max)) of 160 fmol/mg protein. In competition binding studies, affinities were determined for 15 chemically diverse 5-HT(1B) agonists, including 2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl]-1H-indole-3-yl]ethylamine (L694,247; pK(i), 10.4), 5-carboxamidotryptamine (5-CT; 9.7), 3-[3-(2-dimethylamino-ethyl)-1H-indol-6-yl]-N-(4-methoxybenzyl)acrylamide (GR46,611; 9.6), 5-methoxy-3-(1,2,5,6-tetrahydro-4-pyridinyl)-1H-indole (RU24,969; 9.5), dihydroergotamine (DHE; 8.6), 5-H-pyrrolo[3,2-b]pyridin-5-one,1,4-dihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl (CP93,129; 8.4), anpirtoline (7.9), sumatriptan (7.4), 1-[2-(3-fluorophenyl)ethyl]-4-[3-[5-(1,2,4-triazol-4-yl)-1H-indol-3-yl]propyl]piperazine (L775,606; 6.4) and (minus sign)-1(S)-[2-[4-(4-methoxyphenyl)piperazin-1-yl]ethyl]-N-methyl-3,4-dihydro-1H-2-benzopyran-6-carboxamide (PNU109,291; <5.0). Similarly, affinities were established for 13 chemically diverse antagonists, including N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-3-methyl-4-(4-pyridyl)benzamide (GR125,743; pK(i), 9.1), (-)cyanopindolol (9.0), (-)-tertatolol (8.2), N-(4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiozol-3-yl)biphenyl-4-carboxamide (GR127,935; 8.2), N-[3

Study of the mechanism of the relaxant action of (+)-glaucine in rat vas deferens.

PubMed Central

Orallo, F.; Fernández Alzueta, A.; Loza, M. I.; Vivas, N.; Badía, A.; Campos, M.; Honrubia, M. A.; Cadavid, M. I.

1993-01-01

1. Effects of the aporphinoid alkaloid, (+)-glaucine, on rat vas deferens were investigated. 2. (+)-Glaucine (2-18 microM) competitively inhibited contractions induced by noradrenaline and methoxamine with a pA2 value of about 6. 3. (+)-Glaucine (2 and 18 microM) did not change the accumulation of tritium during incubation of the vas deferens with [3H]-noradrenaline. 4. (+)-Glaucine (0.3 nM-0.1 mM) inhibited specific [3H]-prazosin binding to membranes from rat vas deferens with a pKi value of 6.63, which is close to the pA2 value obtained against noradrenaline and methoxamine in functional studies. 5. In electrically-stimulated rat vas deferens, (+)-glaucine (0.3-10 microM) enhanced twitch contractions and competitively antagonized the inhibitory effect of clonidine with a pA2 value of 5.91. 6. In tissues incubated in depolarizing calcium-free high-potassium medium, (+)-glaucine (30-80 microM) inhibited Ca(2+)-induced contractions with depression of the maximal response at higher doses and with a pD'2 value of 3.65. Furthermore, (+)-glaucine (50 microM) did not modify basal 45Ca uptake but strongly inhibited the influx of 45Ca induced by K+. 7. These results suggest that (+)-glaucine has non-selective alpha 1- and alpha 2-adrenoceptor blocking properties. At higher doses, (+)-glaucine shows calcium antagonist activity which may be responsible, at least in part, for the inhibition of the contractions induced by Ca2+ in calcium-free high-potassium medium. PMID:8298818

Finland's strategy and implementation of citizens' access to health information.

PubMed

Ruotsalainen, Pekka; Iivari, Anna-Kaisa; Doupi, Persephone

2008-01-01

The strategy for utilizing information technology in the field of social welfare and health care in Finland was published in 1996. It was redefined in the year 2006. This updated strategy defined basic principles how digitized EHRs should be stored, accessed, disclosed and archived. The strategy together with new legislation opened the right to patients and citizens to access their own EHRs, ePrescriptions and audit-logs via the Internet. A national WEB-service platform forms the base for both public and private eHealth applications. National identification and PKI-services cover health professionals, patients and entities. Citizen's consent management is provided at national level. The access to personal health information is managed using rules derived from legislation. The roll-out of the national health information infrastructure with citizen access to personal health information should by law be finalized before the end of 2011. The implementation of the NHII is demanding, but the real challenge is to clearly understand what the impacts of citizen access to personal health information are and to what direction this kind of services should be developed. At the present state, the Finnish EHR-archive contains only information created by a health professional. Citizens' eHealth services can not be limited to the use of regulated EHR data and ePrescriptions. For health promotion, proactive prevention and health prediction more comprehensive information is needed. Therefore the next step is to develop legislation and to build a trusted environment for the use and access of heterogeneous health and welfare information.

Sustained ligand-activated preconditioning via δ-opioid receptors.

PubMed

Peart, Jason N; Hoe, Louise E See; Gross, Garrett J; Headrick, John P

2011-01-01

We have previously described novel cardioprotection in response to sustained morphine exposure, efficacious in young to aged myocardium and mechanistically distinct from conventional opioid or preconditioning (PC) responses. We further investigate opioid-dependent sustained ligand-activated preconditioning (SLP), assessing duration of protection, opioid receptor involvement, additivity with conventional responses, and signaling underlying preischemic induction of the phenotype. Male C57BL/6 mice were treated with morphine (75-mg subcutaneous pellet) for 5 days followed by morphine-free periods (0, 3, 5, or 7 days) before ex vivo assessment of myocardial tolerance to 25-min ischemia/45-min reperfusion. SLP substantially reduced infarction (by ∼50%) and postischemic contractile dysfunction (eliminating contracture, doubling force development). Cardioprotection persisted for 5 to 7 days after treatment. SLP was induced specifically by δ-receptor and not κ- or μ-opioid receptor agonism, was eliminated by δ-receptor and nonselective antagonism, and was additive with adenosinergic but not acute morphine- or PC-triggered protection. Cotreatment during preischemic morphine exposure with the phosphoinositide-3 kinase (PI3K) inhibitor wortmannin, but not the protein kinase A (PKA) inhibitor myristoylated PKI-(14-22)-amide, prevented induction of SLP. This was consistent with shifts in total and phospho-Akt during the induction period. In summary, data reveal that SLP triggers sustained protection from ischemia for up to 7 days after stimulus, is δ-opioid receptor mediated, is induced in a PI3K-dependent/PKA-independent manner, and augments adenosinergic protection. Mechanisms underlying SLP may be useful targets for manipulation of ischemic tolerance in young or aged myocardium.

In vitro pharmacological characterization of CJ-042794, a novel, potent, and selective prostaglandin EP(4) receptor antagonist.

PubMed

Murase, Akio; Taniguchi, Yasuhito; Tonai-Kachi, Hiroko; Nakao, Kazunari; Takada, Junji

2008-01-16

Activation of the prostaglandin E(2) (PGE(2)) EP(4) receptor, a G-protein-coupled receptor (GPCR), results in increases in intracellular cyclic AMP (cAMP) levels via stimulation of adenylate cyclase. Here we describe the in vitro pharmacological characterization of a novel EP(4) receptor antagonist, CJ-042794 (4-{(1S)-1-[({5-chloro-2-[(4-fluorophenyl)oxy]phenyl}carbonyl)amino]ethyl}benzoic acid). CJ-042794 inhibited [(3)H]-PGE(2) binding to the human EP(4) receptor with a mean pK(i) of 8.5, a binding affinity that was at least 200-fold more selective for the human EP(4) receptor than other human EP receptor subtypes (EP(1), EP(2), and EP(3)). CJ-042794 did not exhibit any remarkable binding to 65 additional proteins, including GPCRs, enzymes, and ion channels, suggesting that CJ-042794 is highly selective for the EP(4) receptor. CJ-042794 competitively inhibited PGE(2)-evoked elevations of intracellular cAMP levels in HEK293 cells overexpressing human EP(4) receptor with a mean pA(2) value of 8.6. PGE(2) inhibited the lipopolysaccharide (LPS)-induced production of tumor necrosis factor alpha (TNFalpha) in human whole blood (HWB); CJ-042794 reversed the inhibitory effects of PGE(2) on LPS-induced TNFalpha production in a concentration-dependent manner. These results suggest that CJ-042794, a novel, potent, and selective EP(4) receptor antagonist, has excellent pharmacological properties that make it a useful tool for exploring the physiological role of EP(4) receptors.

Global teleseismic earthquake relocation with improved travel times and procedures for depth determination

USGS Publications Warehouse

Robert, Engdah E.; Van Hilst, R. D.; Buland, Raymond P.

1998-01-01

We relocate nearly 100, 000 events that occurred during the period 1964 to 1995 and are well-constrained teleseismically by arrival-time data reported to the International Seismological Centre (ISC) and to the U. S. Geological Survey's National Earthquake Information Center (NEIC). Hypocenter determination is significantly improved by using, in addition to regional and teleseismic P and S phases, the arrival times of PKiKP, PKPdf, and the teleseismic depth phases pP, pwP, and sP in the relocation procedure. A global probability model developed for later-arriving phases is used to independently identify the depth phases. The relocations are compared to hypocenters reported in the ISC and NEIC catalogs and by other sources. Differences in our epicenters with respect to ISC and NEIC estimates are generally small and regionally systematic due to the combined effects of the observing station network and plate geometry regionally, differences in upper mantle travel times between the reference earth models used, and the use of later-arriving phases. Focal depths are improved substantially over most other independent estimates, demonstrating (for example) how regional structures such as downgoing slabs can severely bias depth estimation when only regional and teleseismic P arrivals are used to determine the hypocenter. The new data base, which is complete to about Mw 5. 2 and includes all events for which moment-tensor solutions are available, has immediate application to high-resolution definition of Wadati-Benioff Zones (WBZs) worldwide, regional and global tomographic imaging, and other studies of earth structure.

Crystal structure of the Xpo1p nuclear export complex bound to the SxFG/PxFG repeats of the nucleoporin Nup42p.

PubMed

Koyama, Masako; Hirano, Hidemi; Shirai, Natsuki; Matsuura, Yoshiyuki

2017-10-01

Xpo1p (yeast CRM1) is the major nuclear export receptor that carries a plethora of proteins and ribonucleoproteins from the nucleus to cytoplasm. The passage of the Xpo1p nuclear export complex through nuclear pore complexes (NPCs) is facilitated by interactions with nucleoporins (Nups) containing extensive repeats of phenylalanine-glycine (so-called FG repeats), although the precise role of each Nup in the nuclear export reaction remains incompletely understood. Here we report structural and biochemical characterization of the interactions between the Xpo1p nuclear export complex and the FG repeats of Nup42p, a nucleoporin localized at the cytoplasmic face of yeast NPCs and has characteristic SxFG/PxFG sequence repeat motif. The crystal structure of Xpo1p-PKI-Nup42p-Gsp1p-GTP complex identified three binding sites for the SxFG/PxFG repeats on HEAT repeats 14-20 of Xpo1p. Mutational analyses of Nup42p showed that the conserved serines and prolines in the SxFG/PxFG repeats contribute to Xpo1p-Nup42p binding. Our structural and biochemical data suggest that SxFG/PxFG-Nups such as Nup42p and Nup159p at the cytoplasmic face of NPCs provide high-affinity docking sites for the Xpo1p nuclear export complex in the terminal stage of NPC passage and that subsequent disassembly of the nuclear export complex facilitates recycling of free Xpo1p back to the nucleus. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Prediction of N-Methyl-D-Aspartate Receptor GluN1-Ligand Binding Affinity by a Novel SVM-Pose/SVM-Score Combinatorial Ensemble Docking Scheme

PubMed Central

Leong, Max K.; Syu, Ren-Guei; Ding, Yi-Lung; Weng, Ching-Feng

2017-01-01

The glycine-binding site of the N-methyl-D-aspartate receptor (NMDAR) subunit GluN1 is a potential pharmacological target for neurodegenerative disorders. A novel combinatorial ensemble docking scheme using ligand and protein conformation ensembles and customized support vector machine (SVM)-based models to select the docked pose and to predict the docking score was generated for predicting the NMDAR GluN1-ligand binding affinity. The predicted root mean square deviation (RMSD) values in pose by SVM-Pose models were found to be in good agreement with the observed values (n = 30, r2 = 0.928–0.988,  = 0.894–0.954, RMSE = 0.002–0.412, s = 0.001–0.214), and the predicted pKi values by SVM-Score were found to be in good agreement with the observed values for the training samples (n = 24, r2 = 0.967,  = 0.899, RMSE = 0.295, s = 0.170) and test samples (n = 13, q2 = 0.894, RMSE = 0.437, s = 0.202). When subjected to various statistical validations, the developed SVM-Pose and SVM-Score models consistently met the most stringent criteria. A mock test asserted the predictivity of this novel docking scheme. Collectively, this accurate novel combinatorial ensemble docking scheme can be used to predict the NMDAR GluN1-ligand binding affinity for facilitating drug discovery. PMID:28059133

PKA catalytic subunit compartmentation regulates contractile and hypertrophic responses to β-adrenergic signaling

PubMed Central

Yang, Jason H.; Polanowska-Grabowska, Renata K.; Smith, Jeffrey S.; Shields, Charles W.; Saucerman, Jeffrey J.

2014-01-01

β-adrenergic signaling is spatiotemporally heterogeneous in the cardiac myocyte, conferring exquisite control to sympathetic stimulation. Such heterogeneity drives the formation of protein kinase A (PKA) signaling microdomains, which regulate Ca2+ handling and contractility. Here, we test the hypothesis that the nucleus independently comprises a PKA signaling microdomain regulating myocyte hypertrophy. Spatially-targeted FRET reporters for PKA activity identified slower PKA activation and lower isoproterenol sensitivity in the nucleus (t50 = 10.60±0.68 min; EC50 = 89.00 nmol/L) than in the cytosol (t50 = 3.71±0.25 min; EC50 = 1.22 nmol/L). These differences were not explained by cAMP or AKAP-based compartmentation. A computational model of cytosolic and nuclear PKA activity was developed and predicted that differences in nuclear PKA dynamics and magnitude are regulated by slow PKA catalytic subunit diffusion, while differences in isoproterenol sensitivity are regulated by nuclear expression of protein kinase inhibitor (PKI). These were validated by FRET and immunofluorescence. The model also predicted differential phosphorylation of PKA substrates regulating cell contractility and hypertrophy. Ca2+ and cell hypertrophy measurements validated these predictions and identified higher isoproterenol sensitivity for contractile enhancements (EC50 = 1.84 nmol/L) over cell hypertrophy (EC50 = 85.88 nmol/L). Over-expression of spatially targeted PKA catalytic subunit to the cytosol or nucleus enhanced contractile and hypertrophic responses, respectively. We conclude that restricted PKA catalytic subunit diffusion is an important PKA compartmentation mechanism and the nucleus comprises a novel PKA signaling microdomain, insulating hypertrophic from contractile β-adrenergic signaling responses. PMID:24225179

Structure-activity relationship of ibogaine analogs interacting with nicotinic acetylcholine receptors in different conformational states.

PubMed

Arias, Hugo R; Feuerbach, Dominik; Targowska-Duda, Katarzyna M; Jozwiak, Krzysztof

2011-09-01

The interaction of ibogaine analogs with nicotinic acetylcholine receptors (AChRs) in different conformational states was studied by functional and structural approaches. The results established that ibogaine analogs: (a) inhibit (±)-epibatidine-induced Ca²⁺ influx in human embryonic muscle AChRs with the following potency sequence (IC(50) in μM): (±)-18-methylaminocoronaridine (5.9±0.3)∼(±)-18-methoxycoronaridine (18-MC) (6.8±0.8)>(-)-ibogaine (17±3)∼(+)-catharanthine (20±1)>(±)-albifloranine (46±13), (b) bind to the [³H]TCP binding site with higher affinity when the Torpedo AChR is in the desensitized state compared to that in the resting state. Similar results were obtained using [³H]18-MC. These and docking results suggest a steric interaction between TCP and ibogaine analogs for the same site, (c) enhance [³H]cytisine binding to resting but not to desensitized AChRs, with desensitizing potencies (apparent EC₅₀) that correlate very well with the pK(i) values in the desensitized state, and (d) there are good bilinear correlations between the ligand molecular volumes and their affinities in the desensitized and resting states, with an optimal volume of ∼345 ų for the ibogaine site. These results indicate that the size of the binding sites for ibogaine analogs, located between the serine and nonpolar rings and shared with TCP, is an important structural feature for binding and for inducing desensitization. Copyright © 2011 Elsevier Ltd. All rights reserved.

PYK2: A Calcium-sensitive Protein Tyrosine Kinase Activated in Response to Fertilization of the Zebrafish Oocyte

PubMed Central

Sharma, Dipika; Kinsey, William H.

2012-01-01

Fertilization begins with binding and fusion of a sperm with the oocyte, a process that triggers a high amplitude calcium transient which propagates through the oocyte and stimulates a series of preprogrammed signal transduction events critical for zygote development. Identification of the pathways downstream of this calcium transient remains an important step in understanding the basis of zygote quality. The present study demonstrates that the calcium-calmodulin sensitive protein tyrosine kinase PYK2 is a target of the fertilization-induced calcium transient in the zebrafish oocyte and that it plays an important role in actin-mediated events critical for sperm incorporation. At fertilization, PYK2 was activated initially at the site of sperm-oocyte interaction and was closely associated with actin filaments forming the fertilization cone. Later PYK2 activation was evident throughout the entire oocyte cortex, however activation was most intense over the animal hemisphere. Fertilization-induced PYK2 activation could be blocked by suppressing calcium transients in the ooplasm via injection of BAPTA as a calcium chelator. PYK2 activation could be artificially induced in unfertilized oocytes by injection of IP3 at concentrations sufficient to induce calcium release. Functionally, suppression of PYK2 activity by chemical inhibition or by injection of a dominant-negative construct encoding the N-terminal ERM domain of PKY2 inhibited formation of an organized fertilization cone and reduced the frequency of successful sperm incorporation. Together, the above findings support a model in which PYK2 responds to the fertilization-induced calcium transient by promoting reorganization of the cortical actin cytoskeleton to form the fertilization cone. PMID:23084926

[The dynamic mitochondria-nuclear redistribution of FKBP51 during the process of adipocyte differentiation is regulated by PKA].

PubMed

Toneatto, Judith; Charó, Nancy L; Susperreguy, Sebastián; Piwien-Pilipuk, Graciela

2013-01-01

Glucocorticoids play an important role in adipogenesis via the glucocorticoid receptor (GR) that forms a heterocomplex with Hsp90-Hsp70 and a high molecular weight immunophilin FKBP51 or FKBP52. We have found that FKBP51 level of expression progressively increases, FKBP52 decreases, whereas Hsp90, Hsp70, and p23 remain unchanged when 3T3-L1 preadipocytes differentiate. Interestingly, FKBP51 translocates from mitochondria to the nucleus at the onset of adipogenesis. FKBP51 transiently concentrates in the nuclear lamina, at a time that this nuclear compartment undergoes its reorganization. FKBP51 nuclear localization is transient, after 48 h it cycles back to mitochondria. We found that the dynamic FKBP51 mitochondrial-nuclear shuttling is regulated by glucocorticoids and mainly on cAMP-PKA signaling since PKA inhibition by myristoilated-PKI, abrogated FKBP51 nuclear translocation induced by 3-isobutyl-1-methylxanthine (IBMX). It has been reported that PKA interacts with GR in a ligand dependent manner potentiating its transcriptional capacity. GR transcriptional capacity is reduced when cells are incubated in the presence of IBMX, forskolin or dibutyryl-cAMP, compounds that induced nuclear translocation of FKBP51, therefore PKA may exert a dual role in the control of GR. In summary, the presence of FKBP51 in the nucleus may be critical for GR transcriptional control, and possibly for the control of other transcription factors that are not members of the nuclear receptor family but are regulated by PKA signaling pathway, when transcription has to be strictly controlled to succeed in the acquisition of the adipocyte phenotype.

Characterization of a new muscarinic toxin from the venom of the Brazilian coral snake Micrurus lemniscatus in rat hippocampus.

PubMed

da Silva, Daniel Coelho; de Medeiros, Wyara Aparecida Araújo; Batista, Isabel de Fátima Correia; Pimenta, Daniel Carvalho; Lebrun, Ivo; Abdalla, Fernando Maurício Francis; Sandoval, Maria Regina Lopes

2011-12-19

We have isolated a new muscarinic protein (MT-Mlα) from the venom of the Brazilian coral snake Micrurus lemniscatus. This small protein, which had a molecular mass of 7,048Da, shared high sequence homology with three-finger proteins that act on cholinergic receptors. The first 12 amino acid residues of the N-terminal sequence were determined to be: Leu-Ile-Cys-Phe-Ile-Cys-Phe-Ser-Pro-Thr-Ala-His. The MT-Mlα was able to displace the [(3)H]QNB binding in the hippocampus of rats. The binding curve in competition experiments with MT-Mlα was indicative of two types of [(3)H]QNB-binding site with pK(i) values of 9.08±0.67 and 6.17±0.19, n=4, suggesting that various muscarinic acetylcholine receptor (mAChR) subtypes may be the target proteins of MT-Mlα. The MT-Mlα and the M(1) antagonist pirenzepine caused a dose-dependent block on total [(3)H]inositol phosphate accumulation induced by carbachol. The IC(50) values for MT-Mlα and pirenzepine were, respectively, 33.1 and 2.26 nM. Taken together, these studies indicate that the MT-Mlα has antagonist effect on mAChRs in rat hippocampus. The results of the present study show, for the first time, that mAChRs function is drastically affected by MT-Mlα since it not only has affinity for mAChRs but also has the ability to inhibit mAChRs. Copyright © 2011 Elsevier Inc. All rights reserved.

Identification of the dopamine autoreceptor in the guinea-pig retina as D2 receptor using novel subtype-selective antagonists

PubMed Central

Weber, Bernd; Schlicker, Eberhard; Sokoloff, Pierre; Stark, Holger

2001-01-01

Dopamine release in the retina is subject to modulation via autoreceptors, which belong to the D2 receptor family (encompassing the D2, D3 and D4 receptors). The aim of the present study was to determine the receptor subtype (D2 vs D3) involved in the inhibition of dopamine release in guinea-pig retinal discs, using established (haloperidol, (S)-nafadotride) and novel dopamine receptor antagonists (ST-148, ST-198). hD2L and hD3 receptors were expressed in CHO cells and the pKi values determined in binding studies with [125I]-iodosulpride were: haloperidol 9.22 vs 8.54; ST-148 7.85 vs 6.60; (S)-nafadotride 8.52 vs 9.51; ST-198 6.14 vs 7.92. The electrically evoked tritium overflow from retinal discs preincubated with [3H]-noradrenaline (which represents quasi-physiological dopamine release) was inhibited by the dopamine receptor agonists B-HT 920 (talipexole) and quinpirole (maximally by 82 and 71%; pEC50 5.80 and 5.83). The concentration-response curves of these agonists were shifted to the right by haloperidol (apparent pA2 8.69 and 8.23) and ST-148 (7.52 and 7.66). (S)-Nafadotride 0.01 μM and ST-198 0.32 μM did not affect the concentration-response curve of B-HT 920. The dopamine autoreceptor in the guinea-pig retina can be classified as a D2 receptor. ST-148 and ST-198 show an improved selectivity for D2 and D3 receptors when compared to haloperidol and (S)-nafadotride, respectively. PMID:11498509

MicroRNA-155 Is Required for Mycobacterium bovis BCG-Mediated Apoptosis of Macrophages

PubMed Central

Ghorpade, Devram Sampat; Leyland, Rebecca; Kurowska-Stolarska, Mariola; Patil, Shripad A.

2012-01-01

Pathogenic mycobacteria, including Mycobacterium tuberculosis and Mycobacterium bovis, cause significant morbidity and mortality worldwide. However, the vaccine strain Mycobacterium bovis BCG, unlike virulent strains, triggers extensive apoptosis of infected macrophages, a step necessary for the elicitation of robust protective immunity. We here demonstrate that M. bovis BCG triggers Toll-like receptor 2 (TLR2)-dependent microRNA-155 (miR-155) expression, which involves signaling cross talk among phosphatidylinositol 3-kinase (PI3K), protein kinase Cδ (PKCδ), and mitogen-activated protein kinases (MAPKs) and recruitment of NF-κB and c-ETS to miR-155 promoter. Genetic and signaling perturbations presented the evidence that miR-155 regulates PKA signaling by directly targeting a negative regulator of PKA, protein kinase inhibitor alpha (PKI-α). Enhanced activation of PKA signaling resulted in the generation of PKA C-α; phosphorylation of MSK1, cyclic AMP response element binding protein (CREB), and histone H3; and recruitment of phospho-CREB to the apoptotic gene promoters. The miR-155-triggered activation of caspase-3, BAK1, and cytochrome c translocation involved signaling integration of MAPKs and epigenetic or posttranslational modification of histones or CREB. Importantly, M. bovis BCG infection-induced apoptosis was severely compromised in macrophages derived from miR-155 knockout mice. Gain-of-function and loss-of-function studies validated the requirement of miR-155 for M. bovis BCG's ability to trigger apoptosis. Overall, M. bovis BCG-driven miR-155 dictates cell fate decisions of infected macrophages, strongly implicating a novel role for miR-155 in orchestrating cellular reprogramming during immune responses to mycobacterial infection. PMID:22473996

First and second generation antipsychotics influence hippocampal gamma oscillations by interactions with 5-HT3 and D3 receptors

PubMed Central

Schulz, Steffen B; Heidmann, Karin E; Mike, Arpad; Klaft, Zin-Juan; Heinemann, Uwe; Gerevich, Zoltan

2012-01-01

BACKGROUND AND PURPOSE Disturbed cortical gamma band oscillations (30–80 Hz) have been observed in schizophrenia: positive symptoms of the disease correlate with an increase in gamma oscillation power, whereas negative symptoms are associated with a decrease. EXPERIMENTAL APPROACH Here we investigated the effects of first and second generation antipsychotics (FGAs and SGAs, respectively) on gamma oscillations. The FGAs haloperidol, flupenthixol, chlorpromazine, chlorprothixene and the SGAs clozapine, risperidone, ziprasidone, amisulpride were applied on gamma oscillations induced by acetylcholine and physostigmine in the CA3 region of rat hippocampal slices. KEY RESULTS Antipsychotics inhibited the power of gamma oscillations and increased the bandwidth of the gamma band. Haloperidol and clozapine had the highest inhibitory effects. To determine which receptor is responsible for the alterations in gamma oscillations, the effects of the antipsychotics were plotted against their pKi values for 19 receptors and analysed for correlation. Our results indicated that 5-HT3 receptors have an enhancing effect on gamma oscillations whereas dopamine D3 receptors inhibit them. To test this prediction, m-chlorophenylbiguanide, PD 128907 and CP 809101, selective agonists at 5-HT3, D3 and 5-HT2C receptors were applied and revealed that 5-HT3 receptors indeed enhanced the gamma power whereas D3 receptors reduced it. As predicted, 5-HT2C receptors had no effects on gamma oscillations. CONCLUSION AND IMPLICATIONS Our data suggest that antipsychotics alter hippocampal gamma oscillations by interacting with 5-HT3 and dopamine D3 receptors. Moreover, a correlation of receptor affinities with the biological effects can be used to predict targets for the pharmacological effects of multi-target drugs. PMID:22817643

Design and synthesis of novel sulfonamide-containing bradykinin hB2 receptor antagonists. 1. Synthesis and SAR of alpha,alpha-dimethylglycine sulfonamides.

PubMed

Fattori, Daniela; Rossi, Cristina; Fincham, Christopher I; Berettoni, Marco; Calvani, Federico; Catrambone, Fernando; Felicetti, Patrizia; Gensini, Martina; Terracciano, Rosa; Altamura, Maria; Bressan, Alessandro; Giuliani, Sandro; Maggi, Carlo A; Meini, Stefania; Valenti, Claudio; Quartara, Laura

2006-06-15

We recently published the extensive in vivo pharmacological characterization of MEN 16132 (J. Pharmacol. Exp. Ther. 2005, 616-623; Eur. J. Pharmacol. 2005, 528, 7), a member of the sulfonamide-containing human B(2) receptor (hB(2)R) antagonists. Here we report, in detail, how this family of compounds was designed, synthesized, and optimized to provide a group of products with subnanomolar affinity for the hB(2)R and high in vivo potency after topical administration to the respiratory tract. The series was designed on the basis of indications from the X-ray structures of the key structural motifs A and B present in known antagonists and is characterized by the presence of an alpha,alpha-dialkyl amino acid. The first lead (17) of the series was submitted to extensive chemical work to elucidate the structural requirements to increase hB(2) receptor affinity and antagonist potency in bioassays expressing the human B(2) receptor (hB(2)R). The following structural features were selected: a 2,4-dimethylquinoline moiety and a piperazine linker acylated with a basic amino acid. The representative lead compound 68 inhibited the specific binding of [(3)H]BK to hB(2)R with a pKi of 9.4 and antagonized the BK-induced inositolphosphate (IP) accumulation in recombinant cell systems expressing the hB(2)R with a pA(2) of 9.1. Moreover, compound 68 when administered (300 nmol/kg) intratracheally in the anesthetized guinea pig, was able to significantly inhibit BK-induced bronchoconstriction for up to 120 min after its administration, while having a lower and shorter lasting effect on hypotension.

First-in-Human Study of PF-05212384 (PKI-587), a Small-Molecule, Intravenous, Dual Inhibitor of PI3K and mTOR in Patients with Advanced Cancer.

PubMed

Shapiro, Geoffrey I; Bell-McGuinn, Katherine M; Molina, Julian R; Bendell, Johanna; Spicer, James; Kwak, Eunice L; Pandya, Susan S; Millham, Robert; Borzillo, Gary; Pierce, Kristen J; Han, Lixin; Houk, Brett E; Gallo, Jorge D; Alsina, Maria; Braña, Irene; Tabernero, Josep

2015-04-15

To evaluate safety (primary endpoint), tolerability, pharmacokinetics, pharmacodynamic profile, and preliminary activity of the intravenous, pan-class I isoform PI3K/mTOR inhibitor PF-05212384 in patients with advanced solid tumors. Part 1 of this open-label phase I study was designed to estimate the maximum-tolerated dose (MTD) in patients with nonselected solid tumors, using a modified continual reassessment method to guide dose escalation. Objectives of part 2 were MTD confirmation and assessment of preliminary activity in patients with selected tumor types and PI3K pathway dysregulation. Seventy-seven of the 78 enrolled patients received treatment. The MTD for PF-05212384, administered intravenously once weekly, was estimated to be 154 mg. The most common treatment-related adverse events (AE) were mucosal inflammation/stomatitis (58.4%), nausea (42.9%), hyperglycemia (26%), decreased appetite (24.7%), fatigue (24.7%), and vomiting (24.7%). The majority of patients treated at the MTD experienced only grade 1 treatment-related AEs. Grade 3 treatment-related AEs occurred in 23.8% of patients at the MTD. No treatment-related grade 4-5 AEs were reported at any dose level. Antitumor activity was noted in this heavily pretreated patient population, with two partial responses (PR) and an unconfirmed PR. Eight patients had long-lasting stable disease (>6 months). Pharmacokinetic analyses showed a biphasic concentration-time profile for PF-05212384 (half-life, 30-37 hours after multiple dosing). PF-05212384 inhibited downstream effectors of the PI3K pathway in paired tumor biopsies. These findings demonstrate the manageable safety profile and antitumor activity of the PI3K/mTOR inhibitor PF-05212384, supporting further clinical development for patients with advanced solid malignancies. ©2015 American Association for Cancer Research.

Nazca-South America Subduction Zone Reflectivity from P'P' Precursors

NASA Astrophysics Data System (ADS)

Gu, Y. J.; Schultz, R.

2012-12-01

Much of what is known about mantle owes to the interpretation of its reflectivity structure. On the global scale mantle stratifications have been attributed to mineralogical phase changes of olivine; two widely observed examples are the 410 and 660 km discontinuities. Among the various seismological tools, results from longer-period SS/PP precursors and high frequency receiver functions are routinely compared to increase the confidence of the recovered mantle stratifications. The former are lower frequency approaches with complex Fresnel zones, while constraints on receiver distribution hinder analysis in oceanic regions for the latter. P'P' precursors are a promising high frequency alternative, capable of resolving small-scale structures (resolution of ~5 km vertically, 200 km laterally) in the mantle, owing to its short-period nature (~1Hz), shallow angle of incidence and nearly symmetric Fresnel zone. However, P'P' precursors are known for several complications: phase triplication (PKiKPPKiKP, PKIKPPKIKP, PKPPKPab and PKPPKPbc) and the maximum-phase Fresnel zones result in strong scattering and asymmetric arrivals. Much of these concerns are alleviated through revamped processing techniques involving stacking, deconvolution, Radon transform and migration. We utilize P'P' precursors to constrain the mantle structure and layering beneath the Nazca-South America subduction zone. Our migration profiles reveal both olivine (e.g., 410, 520, 660) and garnet related transitions in the mantle, with constraints on the sharpness of these transitions. Observations of a depressed 660 are attributed to thermal variations, showing the spatial extent of the impinging Nazca slab. Prominent 520 arrivals near subducted slab material suggest this transition is sharpened to a thickness resonant with P'P' (~10km). The possibility of chemical heterogeneity is evidenced near the top of the mantle transition zone through complicated 410 amplitudes. The existence, depth, sharpness and

Analysis of the actions of the novel dopamine receptor-directed compounds (S)-OSU6162 and ACR16 at the D2 dopamine receptor

PubMed Central

Kara, Elodie; Lin, Hong; Svensson, Kjell; Johansson, Anette M; Strange, Philip G

2010-01-01

BACKGROUND AND PURPOSE The two phenylpiperidines, OSU6162 and ACR16, have been proposed as novel drugs for the treatment of brain disorders, including schizophrenia and Huntington's disease, because of their putative dopamine stabilizing effects. Here we evaluated the activities of these compounds in a range of assays for the D2 dopamine receptor in vitro. EXPERIMENTAL APPROACH The affinities of these compounds for the D2 dopamine receptor were evaluated in competition with [3H]spiperone and [3H]NPA. Agonist activity of these compounds was evaluated in terms of their ability to stimulate [35S]GTPγS binding. KEY RESULTS Both compounds had low affinities for inhibition of [3H]spiperone binding (pKi vs. [3H]spiperone, ACR16: <5, OSU6162: 5.36). Neither compound was able to stimulate [35S]GTPγS binding when assayed in the presence of Na+ ions, but if the Na+ ions were removed, both compounds were low-affinity, partial agonists (Emax relative to dopamine: ACR16: 10.2%, OSU6162:54.3%). Schild analysis of the effects of OSU6162 to inhibit dopamine-stimulated [35S]GTPγS binding indicated Schild slopes of ∼0.9, suggesting little deviation from competitive inhibition. OSU6162 was, however, able to accelerate [3H]NPA dissociation from D2 dopamine receptors, indicating some allosteric effects of this compound. CONCLUSIONS AND IMPLICATIONS The two phenylpiperidines were low-affinity, low-efficacy partial agonists at the D2 dopamine receptor in vitro, possibly exhibiting some allosteric effects. Comparing their in vitro and in vivo effects, the in vitro affinities were a reasonable guide to potencies in vivo. However, the lack of in vitro–in vivo correlation for agonist efficacy needs to be further addressed. PMID:20804495

The novel non-imidazole histamine H3 receptor antagonist DL77 reduces voluntary alcohol intake and ethanol-induced conditioned place preference in mice.

PubMed

Bahi, Amine; Sadek, Bassem; Nurulain, Syed M; Łażewska, Dorota; Kieć-Kononowicz, Katarzyna

2015-11-01

It has become clear that histamine H3 receptors (H3R) have been implicated in modulating ethanol intake and preference in laboratory animals. The novel non-imidazole H3R antagonist DL77 with excellent selectivity profile shows high in-vivo potency as well as in-vitro antagonist affinity with ED50 of 2.1 ± 0.2 mg/kg and pKi=8.08, respectively. In the present study, and applying an unlimited access two-bottle choice procedure, the anti-alcohol effects of the H3R antagonist, DL77 (0, 3, 10 and 30 mg/kg; i.p.), were investigated in adult mice. In this C57BL/6 line, effects of DL77 on voluntary alcohol intake and preference, as well as on total fluid intake were evaluated. Results have shown that DL77, dose-dependently, reduced both ethanol intake and preference. These effects were very selective as both saccharin and quinine, used to control for taste sensitivity, and intakes were not affected following DL77 pre-application. More importantly, systemic administration of DL77 (10 mg/kg) during acquisition inhibited ethanol-induced conditioned-place preference (EtOH-CPP) as measured using an unbiased protocol. The anti-alcohol activity observed for DL77 was abrogated when mice were pretreated with the selective H3R agonist R-(α)-methyl-histamine (RAMH) (10 mg/kg), or with the CNS penetrant H1R antagonist pyrilamine (PYR) (10mg/kg). These results suggest that DL77 has a predominant role in two in vivo effects of ethanol. Therefore, signaling via H3R is essential for ethanol-related consumption and conditioned reward and may represent a novel therapeutic pharmacological target to tackle ethanol abuse and alcoholism. Copyright © 2015 Elsevier Inc. All rights reserved.

Ser123 Is Essential for the Water Channel Activity of McPIP2;1 from Mesembryanthemum crystallinum*

PubMed Central

Amezcua-Romero, Julio C.; Pantoja, Omar; Vera-Estrella, Rosario

2010-01-01

The increased expression of McPIP2;1 (MipC), a root-specific aquaporin (AQP) from Mesembryanthemum crystallinum, under salt stress has suggested a role for this AQP in the salt tolerance of the plant. However, whether McPIP2;1 transports water or another solute and how its activity is regulated are so far unknown. Therefore, wild type (wt) or mutated McPIP2;1 protein was expressed in Xenopus laevis oocytes. Then, the osmotic water permeability (Pf) of the oocytes membrane was assessed by hypotonic challenges. Selectivity of McPIP2;1 to water was determined by radiolabeled glycerol or urea uptake assays. Moreover, swelling and in vitro phosphorylation assays revealed that both water permeation and phosphorylation status of McPIP2;1 were significantly increased by the phosphorylation agonists okadaic acid (OA), phorbol myristate acetate (PMA), and 8-Br-cAMP, and markedly decreased by the inhibitory peptides PKI 14-22 and PKC 20-28, inhibitors of protein kinases A (PKA) and C (PKC), respectively. Substitution of Ser123 or both, Ser123 and Ser282, abolished the water channel activity of McPIP2;1 while substitution of Ser282 only partially inhibited it (51.9% inhibition). Despite lacking Ser123 and/or Ser282, the McPIP2;1 mutant forms were still phosphorylated in vitro, which suggests that phosphorylation may have a dual role on this AQP. Our results indicate that McPIP2;1 water permeability depends completely on Ser123 and is positively regulated by PKA- and PKC-mediated phosphorylation. Regulation of the phosphorylation status of McPIP2;1 may contribute to control water transport through root cells when the plant is subjected to high salinity conditions. PMID:20332086

5D-QSAR for spirocyclic sigma1 receptor ligands by Quasar receptor surface modeling.

PubMed

Oberdorf, Christoph; Schmidt, Thomas J; Wünsch, Bernhard

2010-07-01

Based on a contiguous and structurally as well as biologically diverse set of 87 sigma(1) ligands, a 5D-QSAR study was conducted in which a quasi-atomistic receptor surface modeling approach (program package Quasar) was applied. The superposition of the ligands was performed with the tool Pharmacophore Elucidation (MOE-package), which takes all conformations of the ligands into account. This procedure led to four pharmacophoric structural elements with aromatic, hydrophobic, cationic and H-bond acceptor properties. Using the aligned structures a 3D-model of the ligand binding site of the sigma(1) receptor was obtained, whose general features are in good agreement with previous assumptions on the receptor structure, but revealed some novel insights since it represents the receptor surface in more detail. Thus, e.g., our model indicates the presence of an H-bond acceptor moiety in the binding site as counterpart to the ligands' cationic ammonium center, rather than a negatively charged carboxylate group. The presented QSAR model is statistically valid and represents the biological data of all tested compounds, including a test set of 21 ligands not used in the modeling process, with very good to excellent accuracy [q(2) (training set, n=66; leave 1/3 out) = 0.84, p(2) (test set, n=21)=0.64]. Moreover, the binding affinities of 13 further spirocyclic sigma(1) ligands were predicted with reasonable accuracy (mean deviation in pK(i) approximately 0.8). Thus, in addition to novel insights into the requirements for binding of spirocyclic piperidines to the sigma(1) receptor, the presented model can be used successfully in the rational design of new sigma(1) ligands. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Chronic 5-HT6 receptor modulation by E-6837 induces hypophagia and sustained weight loss in diet-induced obese rats

PubMed Central

Fisas, Angels; Codony, Xavier; Romero, Gonzalo; Dordal, Alberto; Giraldo, Jesus; Mercé, Ramon; Holenz, Jörg; Heal, David; Buschmann, Helmut; Pauwels, Petrus Johan

2006-01-01

E-6837 is a novel, selective and high-affinity 5-HT6 receptor ligand (pKi: 9.13) which in vitro demonstrates partial agonism at a presumably silent rat 5-HT6 receptor and full agonism at a constitutively active human 5-HT6 receptor by monitoring the cAMP signaling pathway. The effects of chronic treatment with E-6837 were determined in diet-induced obese (DIO)-rats on changes in body weight, food and water intake, plasma indices of comorbid risk factors, and weight regain on compound withdrawal. The centrally acting antiobesity drug, sibutramine, was used as the reference comparator. Sustained body weight loss and decreased cumulative food intake of DIO-rats was observed with E-6837 (30 mg kg−1, p.o., twice a day) during the 4-week treatment period. The onset of the E-6837 effect on body weight was slower than that of sibutramine (5 mg kg−1, p.o.), while its maximal effect was greater, that is −15.7 versus −11.0%. E-6837-induced weight loss was exclusively mediated by a decrease (31.7%) in fat mass, with a concomitant reduction (49.6%) in plasma leptin. Reduced obesity was also reflected in improved glycemic control. Although weight regain occurred after withdrawal from either compound, the body weights after E-6837 (−6.6%) remained lower than after sibutramine (−3.8%) indicating that the greater efficacy of the former did not result in profound rebound hyperphagia/weight gain. These results show that the 5-HT6 receptor partial agonist, E-6837, is a promising new approach to the management of obesity with the potential to produce greater sustained weight loss than sibutramine. PMID:16783408

Pharmacological and biochemical analysis of FPL 67156, a novel, selective inhibitor of ecto-ATPase.

PubMed Central

Crack, B E; Pollard, C E; Beukers, M W; Roberts, S M; Hunt, S F; Ingall, A H; McKechnie, K C; IJzerman, A P; Leff, P

1995-01-01

1. FPL 67156 (6-N,N-diethyl-beta, gamma-dibromomethylene-D-ATP), is a newly synthesized analogue of ATP. 2. In a rabbit isolated tracheal epithelium preparation, measuring P2U-purinoceptor-dependent chloride secretion, FPL 67156 was discovered to potentiate the responses to UTP but not those to ATP-gamma-S. UTP agonist-concentration effect (E/[A]) curves were shifted to the left by 5-fold in the presence of 100 microM FPL 67156. The differential effect of FPL 67156 on UTP and ATP-gamma-S was hypothesized to be due to the greater susceptibility of UTP to enzymatic dephosphorylation and the ability of FPL 67156 to inhibit this process. 3. FPL 67156 was tested as an ecto-ATPase inhibitor in a human blood cell assay, measuring [gamma 32P]-ATP dephosphorylation. The compound inhibited [gamma 32P]-ATP degradation with a pIC50 of 4.6. 4. FPL 67156 was then tested for its effects on ATP and alpha, beta-methylene-ATP responses at P2X-purinoceptors in the rabbit isolated ear artery. In the concentration range 30 microM-1 mM, the compound potentiated the contractile effects of ATP but not those of alpha, beta-methylene-ATP. At 1 mM, FPL 67156 produced a 34-fold leftward shift of ATP E/[A] curves. 5. The effects of FPL 67156 on ATP E/[A] curves in the rabbit ear artery were analyzed using a theoretical model (Furchgott, 1972) describing the action of an enzyme inhibitor on the effects of a metabolically unstable agonist. This analysis provided an estimate of the pKi for FPL 67156 as an ecto-ATPase inhibitor of 5.2.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7533620

Electronic medical archives: a different approach to applying re-signing mechanisms to digital signatures.

PubMed

Chen, Tzer-Long; Lin, Frank Y S

2011-08-01

Electronic medical records can be defined as a digital format of the traditionally paper-based anamneses, which contains the history of a patient such as his somewhat illness, current health problems, and his chronic treatments. An electronic anamnesis is meant to make the patient's health information more conveniently accessible and transferable between different medical institutions and also easier to be kept quite a long time. Because of such transferability and accessibility of electronic anamneses, we can use less resource than before on storing the patients' medical information. This also means that medical care providers could save more funds on record-keeping and access a patient's medical background directly since shown on the computer screen more quickly and easily. Overall, the service quality has seemingly improved greatly. However, the usage of electronic anamneses involves in some concerned issues such as its related law declaration, and the security of the patient's confidential information. Because of these concerns, a secure medical networking scheme is taking into consideration. Nowadays, the administrators at the medical institutions are facing more challenges on monitoring computers and network systems, because of dramatic advances in this field. For instance, a trusted third party is authorized to access some medical records for a certain period of time. In regard to the security purpose, all the electronic medical records are embedded with both of the public-key infrastructure (PKI) cryptography and the digital signature technique so as to ensure the records well-protected. Since the signatures will be invalid due to the revocation or time expiration, the security of records under this premise would turn into vulnerable. Hence, we propose a re-signing scheme, whose purpose is to make a going-expired digital signature been resigned in time, in keeping with the premise of not conflicting with the laws, morals, and privacy while maintaining the

RSA-Based Password-Authenticated Key Exchange, Revisited

NASA Astrophysics Data System (ADS)

Shin, Seonghan; Kobara, Kazukuni; Imai, Hideki

The RSA-based Password-Authenticated Key Exchange (PAKE) protocols have been proposed to realize both mutual authentication and generation of secure session keys where a client is sharing his/her password only with a server and the latter should generate its RSA public/private key pair (e, n), (d, n) every time due to the lack of PKI (Public-Key Infrastructures). One of the ways to avoid a special kind of off-line (so called e-residue) attacks in the RSA-based PAKE protocols is to deploy a challenge/response method by which a client verifies the relative primality of e and φ(n) interactively with a server. However, this kind of RSA-based PAKE protocols did not give any proof of the underlying challenge/response method and therefore could not specify the exact complexity of their protocols since there exists another security parameter, needed in the challenge/response method. In this paper, we first present an RSA-based PAKE (RSA-PAKE) protocol that can deploy two different challenge/response methods (denoted by Challenge/Response Method1 and Challenge/Response Method2). The main contributions of this work include: (1) Based on the number theory, we prove that the Challenge/Response Method1 and the Challenge/Response Method2 are secure against e-residue attacks for any odd prime e (2) With the security parameter for the on-line attacks, we show that the RSA-PAKE protocol is provably secure in the random oracle model where all of the off-line attacks are not more efficient than on-line dictionary attacks; and (3) By considering the Hamming weight of e and its complexity in the. RSA-PAKE protocol, we search for primes to be recommended for a practical use. We also compare the RSA-PAKE protocol with the previous ones mainly in terms of computation and communication complexities.

Inner Core Structure Behind the PKP Core Phase Triplication

NASA Astrophysics Data System (ADS)

Blom, N.; Paulssen, H.; Deuss, A. F.; Waszek, L.

2015-12-01

Despite its small size, the Earth's inner core plays an important role in the Earth's dynamics. Because it is slowly growing, its structure - and the variation thereof with depth - may reveal important clues about the history of the core, its convection and the resulting geodynamo. Learning more about this structure has been a prime effort in the past decades, leading to discoveries about anisotropy, hemispheres and heterogeneity in the inner core in general. In terms of detailed structure, mainly seismic body waves have contributed to these advances. However, at depths between ~100-200 km, the seismic structure is relatively poorly known. This is a result of the PKP core phase triplication and the existence of strong precursors to PKP phases, whose simultaneous arrival hinders the measurement of inner core waves PKIKP at epicentral distances between roughly 143-148°. As a consequence, the interpretation of deeper structure also remains difficult. To overcome these issues, we stack seismograms in slowness and time, separating PKP and PKIKP phases which arrive simultaneously, but with different slowness. We apply this method to study the inner core's Western hemisphere between South and Central America using paths travelling in the quasi-polar direction between epicentral distances of 140-150°. This enables us to measure PKiKP-PKIKP differential travel times up to greater epicentral distance than has previously been done. The resulting differential travel time residuals increase with epicentral distance, indicating a marked increase in seismic velocity with depth compared to reference model AK135 for the studied polar paths. Assuming a homogeneous outer core, these findings can be explained by either (i) inner core heterogeneity due to an increase in isotropic velocity, or (ii) increase in anisotropy over the studied depth range. Our current data set cannot distinguish between the two hypotheses, but in light of previous work we prefer the latter interpretation.

Negative feedback exerted by cAMP-dependent protein kinase and cAMP phosphodiesterase on subsarcolemmal cAMP signals in intact cardiac myocytes: an in vivo study using adenovirus-mediated expression of CNG channels.

PubMed

Rochais, Francesca; Vandecasteele, Grégoire; Lefebvre, Florence; Lugnier, Claire; Lum, Hazel; Mazet, Jean-Luc; Cooper, Dermot M F; Fischmeister, Rodolphe

2004-12-10

Intracardiac cAMP levels are modulated by hormones and neuromediators with specific effects on contractility and metabolism. To understand how the same second messenger conveys different information, mutants of the rat olfactory cyclic nucleotide-gated (CNG) channel alpha-subunit CNGA2, encoded into adenoviruses, were used to monitor cAMP in adult rat ventricular myocytes. CNGA2 was not found in native myocytes but was strongly expressed in infected cells. In whole cell patch-clamp experiments, the forskolin analogue L-858051 (L-85) elicited a non-selective, Mg2+ -sensitive current observed only in infected cells, which was thus identified as the CNG current (ICNG). The beta-adrenergic agonist isoprenaline (ISO) also activated ICNG, although the maximal efficiency was approximately 5 times lower than with L-85. However, ISO and L-85 exerted a similar maximal increase of the L-type Ca2+ current. The use of a CNGA2 mutant with a higher sensitivity for cAMP indicated that this difference is caused by the activation of a localized fraction of CNG channels by ISO. cAMP-dependent protein kinase (PKA) blockade with H89 or PKI, or phosphodiesterase (PDE) inhibition with IBMX, dramatically potentiated ISO- and L-85-stimulated ICNG. A similar potentiation of beta-adrenergic stimulation occurred when PDE4 was blocked, whereas PDE3 inhibition had a smaller effect (by 2-fold). ISO and L-85 increased total PDE3 and PDE4 activities in cardiomyocytes, although this effect was insensitive to H89. However, in the presence of IBMX, H89 had no effect on ISO stimulation of ICNG. This study demonstrates that subsarcolemmal cAMP levels are dynamically regulated by a negative feedback involving PKA stimulation of subsarcolemmal cAMP-PDE.

A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors.

PubMed

Petri, Doris; Schlicker, Eberhard

2016-07-01

The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with (3)H-noradrenaline and hippocampal slices with (3)H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration-response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus. This article is part of the Special Issue entitled 'Histamine Receptors'. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antiaggregant and antivasospastic properties of the new thromboxane A2 receptor antagonist sodium 4-[[1-[[[(4-chlorophenyl)sulfonyl]amino]methyl]cyclopentyl] methyl]benzeneacetate.

PubMed

Lardy, C; Rousselot, C; Chavernac, G; Depin, J C; Guerrier, D

1994-11-01

LCB 2853 (sodium 4-[[1-[[[(4-chlorophenyl)sulfonyl]amino]methyl]cyclopentyl] methyl]benzeneacetate, CAS 141335-11-7) was demonstrated to be a potent thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor antagonist in in vitro, ex vivo and in vivo experiments. The specific mechanism of action was studied in [3H]SQ 29548 receptor binding studies (pKi = 7.93) and was shown to be of competitive nature in U 46619-induced platelet aggregation (pA2 = 6.82). TXA2-dependent platelet rich plasma (PRP) aggregation (U 46619, arachidonic acid (AA), collagen, ADP or serotonin second phase) was inhibited in vitro in humans (IC50:0.037-0.65 mumol/l) and different animal species, as well as ex vivo i.v. rat and p.o. guinea-pig AA-induced aggregation (ED50 = 48 and 57 micrograms/kg). The U 46619-induced contractions of aorta, caudal artery and trachea were inhibited in a dose-dependent way (IC50 = 0.07, 0.02 and 0.5 mumol/l respectively). In vivo, both against platelet aggregation and vasoconstriction, LCB 2853 showed an ED50 lower than 1 mg/kg i.v. in rat AA-induced thrombocytopenia or U 46619-induced hypertension (ED50 = 0.25 and 0.16 mg/kg) as well as in AA-induced sudden death in the mouse (ED50 = 0.44 mg/kg). The U 46619-induced bronchoconstriction was blocked after i.v. administration of LCB 2853 (ED50 = 18.4 micrograms/kg). The duration of action observed in different models was 6 h by oral route and between 3 and 5 h by intravenous route. These properties in TXA2-dependent models led to further investigations of the antithrombotic activity of this novel TXA2 antagonist.

Radioligand binding characterization of the bradykinin B(2) receptor in the rabbit and pig ileal smooth muscle.

PubMed

Meini, Stefania; Cucchi, Paola; Catalani, Claudio; Bellucci, Francesca; Santicioli, Paolo; Giuliani, Sandro; Maggi, Carlo Alberto

2010-06-10

Several species-related differences have been reported in kinin B(2) receptor pharmacology. The present study aimed to evaluate the affinity of the bradykinin B(2) receptor antagonist MEN16132 for the rabbit and pig B(2) receptor, and radioligand binding experiments using [(3)H]bradykinin and membranes of rabbit and pig ileum smooth muscle were conducted. The [(3)H]bradykinin binding was characterized by homologous displacement curves indicating K(d) values of 0.65 and 0.33nM in rabbit and pig, respectively. The B(2) receptor specificity of [(3)H]bradykinin binding was shown by the low affinity (>microM) displayed by agonists ([desArg(9)]bradykinin and Lys[desArg(9)]bradykinin) and antagonists [Leu(8),desArg(9)]bradykinin and Lys[Leu(8),desArg(9)]bradykinin) selective for the B(1) receptor. The affinity of MEN16132 and other antagonists was determined by inhibition curves (pK(i) values in the rabbit and pig assay, respectively): MEN16132 (10.4 and 10.3) and peptide compounds such as icatibant (10.1 and 9.9) and MEN11270 (10.3 and 10.1) displayed subnanomolar potency in both assays; the nonpeptide LF16-0687 (8.4 and 8.5) and FR173657 (8.2 and 9.1) exhibited a different affinity pattern, whereas WIN64338 displayed low affinity (5.7 and

In vitro modulation of the interaction between HA95 and LAP2beta by cAMP signaling.

PubMed

Martins, Sandra B; Marstad, Anne; Collas, Philippe

2003-09-09

The nuclear envelope mediates key functions by interacting with chromatin. We recently reported an interaction between the chromatin- and nuclear matrix-associated protein HA95 and the inner nuclear membrane integral protein LAP2beta, implicated in initiation of DNA replication (Martins et al. (2003) J. Cell Biol. 160, 177-188). Here, we show that in vitro, interaction between HA95 and LAP2beta is modulated by cAMP signaling via PKA. Exposure of an anti-HA95 immune precipitate from interphase HeLa cells to a mitotic extract promotes ATP-dependent release of LAP2beta from the HA95 complex. This coincides with Ser and Thr phosphorylation of HA95 and LAP2beta. Inhibition of PKA with PKI abolishes phosphorylation of HA95 and dissociation of LAP2beta from HA95, although LAPbeta remains phosphorylated. Antagonizing cAMP signaling in mitotic extract also abolishes the release of LAP2beta from HA95; however, disrupting PKA anchoring to A-kinase anchoring proteins has no effect. Inhibition of CDK activity in the extract greatly reduces LAP2beta phosphorylation but does not prevent LAP2beta release from HA95. Inhibition of PKC, MAP kinase, or CaM kinase II does not affect mitotic extract-induced dissociation of LAP2beta from HA95. PKA phosphorylates HA95 but not LAP2beta in vitro and elicits a release of LAP2beta from HA95. CDK1 or PKC phosphorylates LAP2beta within the HA95 complex, but neither kinase induces LAP2beta release. Our results indicate that in vitro, the interaction between HA95 and LAP2beta is influenced by a PKA-mediated phosphorylation of HA95 rather than by CDK1- or PKC-mediated phosphorylation of LAP2beta. This suggests an additional level of regulation of a chromatin-nuclear envelope interaction in dividing cells.

Kunitz Proteinase Inhibitors Limit Water Stress Responses in White Clover (Trifolium repens L.) Plants.

PubMed

Islam, Afsana; Leung, Susanna; Nikmatullah, Aluh; Dijkwel, Paul P; McManus, Michael T

2017-01-01

The response of plants to water deficiency or drought is a complex process, the perception of which is triggered at the molecular level before any visible morphological responses are detected. It was found that different groups of plant proteinase inhibitors (PIs) are induced and play an active role during abiotic stress conditions such as drought. Our previous work with the white clover ( Trifolium repens L.) Kunitz Proteinase Inhibitor ( Tr-KPI ) gene family showed that Tr-KPIs are differentially regulated to ontogenetic and biotic stress associated cues and that, at least some members of this gene family may be required to maintain cellular homeostasis. Altered cellular homeostasis may also affect abiotic stress responses and therefore, we aimed to understand if distinct Tr-PKI members function during drought stress. First, the expression level of three Tr-KPI genes, Tr-KPI1 , Tr-KPI2 , and Tr-KPI5 , was measured in two cultivars and one white clover ecotype with differing capacity to tolerate drought. The expression of Tr-KPI1 and Tr-KPI5 increased in response to water deficiency and this was exaggerated when the plants were treated with a previous period of water deficiency. In contrast, proline accumulation and increased expression of Tr-NCED1 , a gene encoding a protein involved in ABA biosynthesis, was delayed in plants that experienced a previous drought period. RNAi knock-down of Tr-KPI1 and Tr-KPI5 resulted in increased proline accumulation in leaf tissue of plants grown under both well-watered and water-deficit conditions. In addition, increased expression of genes involved in ethylene biosynthesis was found. The data suggests that Tr-KPIs , particularly Tr-KPI5 , have an explicit function during water limitation. The results also imply that the Tr-KPI family has different in planta proteinase targets and that the functions of this protein family are not solely restricted to one of storage proteins or in response to biotic stress.

Kunitz Proteinase Inhibitors Limit Water Stress Responses in White Clover (Trifolium repens L.) Plants

PubMed Central

Islam, Afsana; Leung, Susanna; Nikmatullah, Aluh; Dijkwel, Paul P.; McManus, Michael T.

2017-01-01

The response of plants to water deficiency or drought is a complex process, the perception of which is triggered at the molecular level before any visible morphological responses are detected. It was found that different groups of plant proteinase inhibitors (PIs) are induced and play an active role during abiotic stress conditions such as drought. Our previous work with the white clover (Trifolium repens L.) Kunitz Proteinase Inhibitor (Tr-KPI) gene family showed that Tr-KPIs are differentially regulated to ontogenetic and biotic stress associated cues and that, at least some members of this gene family may be required to maintain cellular homeostasis. Altered cellular homeostasis may also affect abiotic stress responses and therefore, we aimed to understand if distinct Tr-PKI members function during drought stress. First, the expression level of three Tr-KPI genes, Tr-KPI1, Tr-KPI2, and Tr-KPI5, was measured in two cultivars and one white clover ecotype with differing capacity to tolerate drought. The expression of Tr-KPI1 and Tr-KPI5 increased in response to water deficiency and this was exaggerated when the plants were treated with a previous period of water deficiency. In contrast, proline accumulation and increased expression of Tr-NCED1, a gene encoding a protein involved in ABA biosynthesis, was delayed in plants that experienced a previous drought period. RNAi knock-down of Tr-KPI1 and Tr-KPI5 resulted in increased proline accumulation in leaf tissue of plants grown under both well-watered and water-deficit conditions. In addition, increased expression of genes involved in ethylene biosynthesis was found. The data suggests that Tr-KPIs, particularly Tr-KPI5, have an explicit function during water limitation. The results also imply that the Tr-KPI family has different in planta proteinase targets and that the functions of this protein family are not solely restricted to one of storage proteins or in response to biotic stress. PMID:29046678

Circulating aldosterone induces the apical accumulation of the proton pumping V-ATPase and increases proton secretion in clear cells in the caput epididymis.

PubMed

Roy, Jeremy W; Hill, Eric; Ruan, Ye Chun; Vedovelli, Luca; Păunescu, Teodor G; Brown, Dennis; Breton, Sylvie

2013-08-15

Clear cells express the vacuolar proton-pumping H(+)-ATPase (V-ATPase) and acidify the lumen of the epididymis, a process that is essential for male fertility. The renin-angiotensin-aldosterone system (RAAS) regulates fluid and electrolyte balance in the epididymis, and a previous study showed binding of aldosterone exclusively to epididymal clear cells (Hinton BT, Keefer DA. Steroid Biochem 23: 231-233, 1985). We examined here the role of aldosterone in the regulation of V-ATPase in the epididymis. RT-PCR showed expression of the mineralocorticoid receptor [MR; nuclear receptor subfamily 3, group C member 2 (NR3C2)] and 11-β-dehydrogenase isozyme 2 (HSD11β2) mRNAs specifically in clear cells, isolated by fluorescence-activated cell sorting from B1-enhanced green fluorescent protein (EGFP) mice. Tail vein injection of adult rats with aldosterone, 1,2-dioctanoyl-sn-glycerol (DOG), or 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) induced V-ATPase apical membrane accumulation and extension of V-ATPase-labeled microvilli in clear cells in the caput epididymis but not in the cauda. V-ATPase activity was measured in EGFP-expressing clear cells using the intracellular pH (pHi)-sensing dye seminaphthorhodafluor-5F-5-(and 6)-carboxylic acid, acetoxymethyl ester acetate (SNARF-5F). Aldosterone induced a rapid increase in the rate of Na(+)- and bicarbonate-independent pHi recovery following an NH4Cl-induced acid load in clear cells isolated from the caput but not the cauda. This effect was abolished by concanamycin A, spironolactone, and chelerythrine but not myristoylated-protein kinase inhibitor (mPKI) or mifepristone. Thus aldosterone increases V-ATPase-dependent proton secretion in clear cells in the caput epididymis via MR/NR3C2 and PKC activation. This study, therefore, identifies aldosterone as an active member of the RAAS for the regulation of luminal acidification in the proximal epididymis.

Efficacy of antipsychotic agents at human 5-HT(1A) receptors determined by [3H]WAY100,635 binding affinity ratios: relationship to efficacy for G-protein activation.

PubMed

Newman-Tancredi, A; Verrièle, L; Touzard, M; Millan, M J

2001-10-05

5-HT(1A) receptors are implicated in the aetiology of schizophrenia. Herein, the influence of 15 antipsychotics on the binding of the selective 'neutral' antagonist, [3H]WAY100,635 ([3H]N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)-cyclo-hexanecarboxamide), was examined at human 5-HT(1A) receptors expressed in Chinese Hamster Ovary cells. In competition binding experiments, 5-HT displayed biphasic isotherms which were shifted to the right in the presence of the G-protein uncoupling agent, GTPgammaS (100 microM). In analogy, the isotherms of ziprasidone, quetiapine and S16924 (((R-2-[1-[2-(2,3-dihydro-benzo[1,4]dioxin-5-yloxy)-ethyl]-pyrrolidin-3yl]-1-(4-fluoro-phenyl)-ethanone), were displaced to the right by GTPgammaS, consistent with agonist actions. Binding of several other antipsychotics, such as ocaperidone, olanzapine and risperidone, was little influenced by GTPgammaS. Isotherms of the neuroleptics, haloperidol, chlorpromazine and thioridazine were shifted to the left in the presence of GTPgammaS, suggesting inverse agonist properties. For most ligands, the magnitude of affinity changes induced by GTPgammaS (alteration in pK(i) values) correlated well with their previously determined efficacies in [35S]GTPgammaS binding studies [Eur. J. Pharmacol. 355 (1998) 245]. In contrast, the affinity of the 'atypical' antipsychotic agent, clozapine, which is a known partial agonist at 5-HT(1A) receptors, was less influenced by GTPgammaS. When the ratio of high-/low-affinity values was plotted against efficacy, hyperbolic isotherms were obtained, consistent with a modified ternary complex model which assumes that receptors can adopt active conformations in the absence of agonist. In conclusion, modulation of [3H]-WAY100,635 binding by GTPgammaS differentiated agonist vs. inverse agonist properties of antipsychotics at 5-HT(1A) receptors. These may contribute to differing profiles of antipsychotic activity.

Investigation of the prejunctional α2-adrenoceptor mediated actions of MDMA in rat atrium and vas deferens

PubMed Central

Lavelle, Aisling; Honner, Valerie; Docherty, J R

1999-01-01

We have investigated the effects of methylenedioxymethamphetamine (MDMA, ‘ecstasy') on peripheral noradrenergic neurotransmission in the rat.In rat atrial slices pre-incubated with [3H]-noradrenaline and in the presence of desipramine (1 μM) to prevent effects of MDMA on basal outflow of tritium, MDMA (10 μM) significantly inhibited the release of tritium evoked by short trains of six pulses at 100 Hz every 10 s for 3 min. This effect did not occur in the presence of the α2-adrenoceptor antagonist yohimbine (1 μM).In epididymal portions of rat vas deferens in the presence of nifedipine (10 μM), MDMA produced a concentration-dependent inhibition of single pulse nerve stimulation-evoked contractions with a pD2 of 5.88±0.16 (n=4). Inhibitory effects of MDMA were antagonized by the α2-adrenoceptor antagonist yohimbine (0.3 μM), but not by the 5-hydroxytryptamine receptor antagonist cyanopindolol in a concentration (1 μM) which markedly antagonized the inhibitory actions of the 5-HT-1 receptor agonist 5-carboxamidotryptamine.In prostatic portions of rat vas deferens in the presence of cocaine (3 μM), MDMA produced a concentration-dependent inhibition of single pulse nerve stimulation-evoked contractions with a pD2 of 5.12±0.21 (n=4). In the absence of cocaine, only the highest concentration of MDMA (30 μM) produced an inhibition, but the α2-adrenoceptor antagonist yohimbine (0.3 μM) converted the response to MDMA from inhibition to potentiation of the stimulation-evoked contraction.In radioligand binding studies, MDMA showed similar affinities for α2B, α2C and α2D-adrenoceptor sites, with pKi values of 5.14±0.16, 5.11±0.05 and 5.31±0.14, respectively.It is concluded that MDMA has significant α2-adrenoceptor agonist actions. PMID:10556934

NPOESS Field Terminal Updates

NASA Astrophysics Data System (ADS)

Heckmann, G.; Route, G.

2009-12-01

downlinks identifying differences between the direct broadcast downlinks including the variability of the LRD downlink and NPOESS management and distribution of decryption keys to approved field terminals using Public Key Infrastructure (PKI) AES standard with 256 bit encryption and elliptical curve cryptography.

Novel Mechanism for Regulation of Epidermal Growth Factor Receptor Endocytosis Revealed by Protein Kinase A Inhibition

PubMed Central

Salazar, Gloria; González, Alfonso

2002-01-01

Current models put forward that the epidermal growth factor receptor (EGFR) is efficiently internalized via clathrin-coated pits only in response to ligand-induced activation of its intrinsic tyrosine kinase and is subsequently directed into a lysosomal-proteasomal degradation pathway by mechanisms that include receptor tyrosine phosphorylation and ubiquitylation. Herein, we report a novel mechanism of EGFR internalization that does not require ligand binding, receptor kinase activity, or ubiquitylation and does not direct the receptor into a degradative pathway. Inhibition of basal protein kinase A (PKA) activity by H89 and the cell-permeable substrate peptide Myr-PKI induced internalization of 40–60% unoccupied, inactive EGFR, and its accumulation into early endosomes without affecting endocytosis of transferrin and μ-opioid receptors. This effect was abrogated by interfering with clathrin function. Thus, the predominant distribution of inactive EGFR at the plasma membrane is not simply by default but involves a PKA-dependent restrictive condition resulting in receptor avoidance of endocytosis until it is stimulated by ligand. Furthermore, PKA inhibition may contribute to ligand-induced EGFR endocytosis because epidermal growth factor inhibited 26% of PKA basal activity. On the other hand, H89 did not alter ligand-induced internalization of EGFR but doubled its half-time of down-regulation by retarding its segregation into degradative compartments, seemingly due to a delay in the receptor tyrosine phosphorylation and ubiquitylation. Our results reveal that PKA basal activity controls EGFR function at two levels: 1) residence time of inactive EGFR at the cell surface by a process of “endocytic evasion,” modulating the accessibility of receptors to stimuli; and 2) sorting events leading to the down-regulation pathway of ligand-activated EGFR, determining the length of its intracellular signaling. They add a new dimension to the fine-tuning of EGFR function

Complex Inner Core of the Earth

NASA Astrophysics Data System (ADS)

Tkalcic, H.; Pachhai, S.; Tanaka, S.; Mattesini, M.; Stephenson, J.

2015-12-01

Recent studies have revealed an increasingly complex structure of the Earth's inner core (IC) in properties such as seismic velocity, attenuation, anisotropy, and differential rotation. In addition, the inner core boundary (ICB) has proven to be more complex than just a dividing boundary between the liquid outer core and the solid IC. On one hand, these advancements have been achieved due to the availability of new data. On the other hand, this is due to better computational facilities, the introduction of new mathematical techniques to this field of study, and a multidisciplinary approach. Through first principles treatment of global seismological differential travel time data, it is possible to acquire a complex mineralogical structure of the IC, consisting of at least three different phases of iron. This has the potential to unify seismological observations and interpretation of IC anisotropy with mineral physics and recent geodynamical scenarios suggesting a predominant degree 1 structure in the IC, although a new complexity emerges from recent attenuation and isotropic velocity studies. A number of studies have recently shown lateral variability of these properties in the uppermost IC, to an increasingly more complex extent than a simple harmonic degree 1. While large earthquakes recorded on individual stations constrain established ray-path corridors through the IC, large arrays provide an unprecedented and overwhelming number of deep Earth-sensitive data. For example, the most complete collection of empirical travel time curves of core phases, from simultaneous recordings of a distant individual earthquake on hundreds of stations is now within reach. Similarly, we can recover hundreds of simultaneous observations of PKiKP and PcP waves from more proximate earthquakes. Traditionally, these have been used to study the sharpness of the ICB by a far more modest number of data points in the time domain. A new study of these observations in the frequency domain

Security and privacy in electronic health records: a systematic literature review.

PubMed

Fernández-Alemán, José Luis; Señor, Inmaculada Carrión; Lozoya, Pedro Ángel Oliver; Toval, Ambrosio

2013-06-01

To report the results of a systematic literature review concerning the security and privacy of electronic health record (EHR) systems. Original articles written in English found in MEDLINE, ACM Digital Library, Wiley InterScience, IEEE Digital Library, Science@Direct, MetaPress, ERIC, CINAHL and Trip Database. Only those articles dealing with the security and privacy of EHR systems. The extraction of 775 articles using a predefined search string, the outcome of which was reviewed by three authors and checked by a fourth. A total of 49 articles were selected, of which 26 used standards or regulations related to the privacy and security of EHR data. The most widely used regulations are the Health Insurance Portability and Accountability Act (HIPAA) and the European Data Protection Directive 95/46/EC. We found 23 articles that used symmetric key and/or asymmetric key schemes and 13 articles that employed the pseudo anonymity technique in EHR systems. A total of 11 articles propose the use of a digital signature scheme based on PKI (Public Key Infrastructure) and 13 articles propose a login/password (seven of them combined with a digital certificate or PIN) for authentication. The preferred access control model appears to be Role-Based Access Control (RBAC), since it is used in 27 studies. Ten of these studies discuss who should define the EHR systems' roles. Eleven studies discuss who should provide access to EHR data: patients or health entities. Sixteen of the articles reviewed indicate that it is necessary to override defined access policies in the case of an emergency. In 25 articles an audit-log of the system is produced. Only four studies mention that system users and/or health staff should be trained in security and privacy. Recent years have witnessed the design of standards and the promulgation of directives concerning security and privacy in EHR systems. However, more work should be done to adopt these regulations and to deploy secure EHR systems. Copyright

Tonic 5nM DA Stabilizes Neuronal Output by Enabling Bidirectional Activity-Dependent Regulation of the Hyperpolarization Activated Current via PKA and Calcineurin

PubMed Central

Krenz, Wulf-Dieter C.; Rodgers, Edmund W.; Baro, Deborah J.

2015-01-01

Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA) at type 1 DA receptors (D1Rs) are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h). In the presence but not absence of 5nM DA, I h maximal conductance (G max) was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP), which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation). Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP’s first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output. PMID

Tonic 5nM DA stabilizes neuronal output by enabling bidirectional activity-dependent regulation of the hyperpolarization activated current via PKA and calcineurin.

PubMed

Krenz, Wulf-Dieter C; Rodgers, Edmund W; Baro, Deborah J

2015-01-01

Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA) at type 1 DA receptors (D1Rs) are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h). In the presence but not absence of 5nM DA, I h maximal conductance (G max) was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP), which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation). Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP's first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output.

Characteristics of AMPA receptor-mediated responses of cultured cortical and spinal cord neurones and their correlation to the expression of glutamate receptor subunits, GluR1-4

PubMed Central

Dai, Wei-Min; Egebjerg, Jan; Lambert, John D C

2001-01-01

Electrophysiological recordings have been used to characterize responses mediated by AMPA receptors expressed by cultured rat cortical and spinal cord neurones. The EC50 values for AMPA were 17 and 11 μM, respectively.Responses of cortical neurones to AMPA were inhibited competitively by NBQX (pKi=6.6). Lower concentrations of NBQX (⩽1 μM) also potentiated the plateau responses of spinal cord neurones to AMPA, which could be attributed to a depression of desensitization to AMPA.GYKI 52466 inhibited responses of spinal cord neurones to AMPA to about twice the extent of responses of cortical neurones.Blockade of AMPA receptor desensitization by cyclothiazide (CTZ) potentiated responses of spinal cord neurones (6.8 fold) significantly more than responses of cortical neurones (4.8 fold). Responses of cortical neurones to KA were potentiated 3.5 fold by CTZ, while responses of spinal cord neurones were unaffected.Ultra-fast applications of AMPA to outside-out patches showed responses of spinal cord neurones desensitized by 97.5% and exhibit marked inward rectification, whereas cortical neurones desensitized by 91% and exhibited slight outward rectification. The time constants of deactivation and desensitization were about twice as fast in spinal cord than cortical neurones.In cortical neurones, single-cell RT – PCR showed GluR2 and GluR1 accounted for 91% of all subunits and were expressed together in 67% of neurones, predominantly as the flip variants (78%). GluR2 was detected alone in 24% of neurones. GluR3 and GluR4 were present in only 14 and 29% of neurones, respectively. For spinal cord neurones, GluR4o was detected in 81% of neurones, whereas predominantly flop versions of GluR1, 2 and 3 were detected in 38, 13 and 13% of neurones, respectively. These expression patterns are related to the respective pharmacological and mechanistic properties. PMID:11309259

Modafinil inhibits K(Ca)3.1 currents and muscle contraction via a cAMP-dependent mechanism.

PubMed

Choi, Shinkyu; Kim, Moon Young; Joo, Ka Young; Park, Seonghee; Kim, Ji Aee; Jung, Jae-Chul; Oh, Seikwan; Suh, Suk Hyo

2012-07-01

Modafinil has been used as a psychostimulant for the treatment of narcolepsy. However, its primary mechanism of action remains elusive. Therefore, we examined the effects of modafinil on K(Ca)3.1 channels and vascular smooth muscle contraction. K(Ca)3.1 currents and channel activity were measured using a voltage-clamp technique and inside-out patches in mouse embryonic fibroblast cell line, NIH-3T3 fibroblasts. Intracellular adenosine 3',5'-cyclic monophosphate (cAMP) concentration was measured, and the phosphorylation of K(Ca)3.1 channel protein was examined using western blotting in NIH-3T3 fibroblasts and/or primary cultured mouse aortic smooth muscle cells (SMCs). Muscle contractions were recorded from mouse aorta and rat pulmonary artery by using a myograph developed in-house. Modafinil was found to inhibit K(Ca)3.1 currents in a concentration-dependent manner, and the half-maximal inhibition (IC(50)) of modafinil for the current inhibition was 6.8 ± 0.7 nM. The protein kinase A (PKA) activator forskolin also inhibited K(Ca)3.1 currents. The inhibitory effects of modafinil and forskolin on K(Ca)3.1 currents were blocked by the PKA inhibitors PKI(14-22) or H-89. In addition, modafinil relaxed blood vessels (mouse aorta and rat pulmonary artery) in a concentration-dependent manner. Modafinil increased cAMP concentrations in NIH-3T3 fibroblasts or primary cultured mouse aortic SMCs and phosphorylated K(Ca)3.1 channel protein in NIH-3T3 fibroblasts. However, open probability and single-channel current amplitudes of K(Ca)3.1 channels were not changed by modafinil. From these results, we conclude that modafinil inhibits K(Ca)3.1 channels and vascular smooth muscle contraction by cAMP-dependent phosphorylation, suggesting that modafinil can be used as a cAMP-dependent K(Ca)3.1 channel blocker and vasodilator. Copyright © 2012 Elsevier Ltd. All rights reserved.

Outstanding scientist of the year 2006: Rogel Patawaran, BS.

PubMed

Rubin, Robert A; Hazirjian, Courtney L

2006-01-01

further reports that out of 100 hospital patients, five or six will be the victim of a preventable error. He states that medication errors alone kill 7000 people each year, adding $2 billion to the overall cost of healthcare. He stresses that these 7000 needless deaths are not only unacceptable but un-American as well. During the 1990s, the pharmaceutical industry sought help from the Food and Drug Administration (FDA) to develop a standard by which a paperless system could be adopted for healthcare. In March of 1997, the FDA issued its final ruling, which established the criteria for which the FDA will recognize the transmission of authenticity within electronic data as well as establishing standards of authenticity for electronic data equivalent to the validity of signatures on paper documents and records. The FDA also recognizes the growth that can be experienced by converting healthcare technology to a paperless system, such as the expediting of patient files in a more organized manner, increasing the speed of file transfer of such documents, reducing prescription errors, enabling computer-generated data analysis and statistics, and reducing storage space. Rogel Patawaran and his colleagues also realized that electronic healthcare technology using the highest standard of data encryption to transfer data could also dramatically improve the safety of patients in our nation and the world. To answer the needs within healthcare technology, Rogel Patawaran created a system for healthcare providers using the most superior encryption methods, and in the process creating iQSolutions, Inc. Its web mail system uses the Public Key Infrastructure (PKI) format, which is the strongest known encryption format. PKI is used in combination with the Advance Encryption Standard (AES) digital encryption algorithm, which is the current algorithm used by banks and government agencies, thereby protecting the privacy and accuracy of the information. Rogel Patawaran's remarkable contributions

Novel antipsychotics activate recombinant human and native rat serotonin 5-HT1A receptors: affinity, efficacy and potential implications for treatment of schizophrenia.

PubMed

Newman-Tancredi, Adrian; Assié, Marie-Bernadette; Leduc, Nathalie; Ormière, Anne-Marie; Danty, Nathalie; Cosi, Cristina

2005-09-01

Serotonin 5-HT1A receptors are promising targets in the management of schizophrenia but little information exists about affinity and efficacy of novel antipsychotics at these sites. We addressed this issue by comparing binding affinity at 5-HT1A receptors with dopamine rD2 receptors, which are important targets for antipsychotic drug action. Agonist efficacy at 5-HT1A receptors was determined for G-protein activation and adenylyl cyclase activity. Whereas haloperidol, thioridazine, risperidone and olanzapine did not interact with 5-HT1A receptors, other antipsychotic agents exhibited agonist properties at these sites. E(max) values (% effect induced by 10 microM of 5-HT) for G-protein activation at rat brain 5-HT1A receptors: sarizotan (66.5), bifeprunox (35.9), SSR181507 (25.8), nemonapride (25.7), ziprasidone (20.6), SLV313 (19), aripiprazole (15), tiospirone (8.9). These data were highly correlated with results obtained at recombinant human 5-HT1A receptors in determinations of G-protein activation and inhibition of forskolin-stimulated adenylyl cyclase. In binding-affinity determinations, the antipsychotics exhibited diverse properties at r5-HT1A receptors: sarizotan (pK(i)=8.65), SLV313 (8.64), SSR181507 (8.53), nemonapride (8.35), ziprasidone (8.30), tiospirone (8.22), aripiprazole (7.42), bifeprunox (7.19) and clozapine (6.31). The affinity ratios of the ligands at 5-HT1A vs. D2 receptors also varied widely: ziprasidone, SSR181507 and SLV313 had similar affinities whereas aripiprazole, nemonapride and bifeprunox were more potent at D2 than 5-HT1A receptors. Taken together, these data indicate that aripiprazole has low efficacy and modest affinity at 5-HT1A receptors, whereas bifeprunox has low affinity but high efficacy. In contrast, SSR181507 has intermediate efficacy but high affinity, and is likely to have more prominent 5-HT1A receptor agonist properties. Thus, the contribution of 5-HT1A receptor activation to the pharmacological profile of action of the

Putative β4-adrenoceptors in rat ventricle mediate increases in contractile force and cell Ca2+: comparison with atrial receptors and relationship to (−)-[3H]-CGP 12177 binding

PubMed Central

Sarsero, Doreen; Molenaar, Peter; Kaumann, Alberto J; Freestone, Nicholas S

1999-01-01

We identified putative β4-adrenoceptors by radioligand binding, measured increases in ventricular contractile force by (−)-CGP 12177 and (±)-cyanopindolol and demonstrated increased Ca2+ transients by (−)-CGP 12177 in rat cardiomyocytes.(−)-[3H]-CGP 12177 labelled 13–22 fmol mg−1 protein ventricular β1, β2-adrenoceptors (pKD ∼9.0) and 50–90 fmol mg−1 protein putative β4-adrenoceptors (pKD ∼7.3). The affinity values (pKi) for (β1,β2-) and putative β4-adrenoceptors, estimated from binding inhibition, were (−)-propranolol 8.4, 5.7; (−)-bupranolol 9.7, 5.8; (±)-cyanopindolol 10.0,7.4.In left ventricular papillary muscle, in the presence of 30 μM 3-isobutyl-1-methylxanthine, (−)-CGP 12177 and (±)-cyanopindolol caused positive inotropic effects, (pEC50, (−)-CGP 12177, 7.6; (±)-cyanopindolol, 7.0) which were antagonized by (−)-bupranolol (pKB 6.7–7.0) and (−)-CGP 20712A (pKB 6.3–6.6). The cardiostimulant effects of (−)-CGP 12177 in papillary muscle, left and right atrium were antagonized by (±)-cyanopindolol (pKP 7.0–7.4).(−)-CGP 12177 (1 μM) in the presence of 200 nM (−)-propranolol increased Ca2+ transient amplitude by 56% in atrial myocytes, but only caused a marginal increase in ventricular myocytes. In the presence of 1 μM 3-isobutyl-1-methylxanthine and 200 nM (−)-propranolol, 1 μM (−)-CGP 12177 caused a 73% increase in Ca2+ transient amplitude in ventricular myocytes. (−)-CGP 12177 elicited arrhythmic transients in some atrial and ventricular myocytes.Probably by preventing cyclic AMP hydrolysis, 3-isobutyl-1-methylxanthine facilitates the inotropic function of ventricular putative β4-adrenoceptors, suggesting coupling to Gs protein-adenylyl cyclase. The receptor-mediated increases in contractile force are related to increases of Ca2+ in atrial and ventricular myocytes. The agreement of binding affinities of agonists with cardiostimulant potencies is consistent with mediation

The GENIUS Grid Portal and robot certificates: a new tool for e-Science

PubMed Central

Barbera, Roberto; Donvito, Giacinto; Falzone, Alberto; La Rocca, Giuseppe; Milanesi, Luciano; Maggi, Giorgio Pietro; Vicario, Saverio

2009-01-01

Background Grid technology is the computing model which allows users to share a wide pletora of distributed computational resources regardless of their geographical location. Up to now, the high security policy requested in order to access distributed computing resources has been a rather big limiting factor when trying to broaden the usage of Grids into a wide community of users. Grid security is indeed based on the Public Key Infrastructure (PKI) of X.509 certificates and the procedure to get and manage those certificates is unfortunately not straightforward. A first step to make Grids more appealing for new users has recently been achieved with the adoption of robot certificates. Methods Robot certificates have recently been introduced to perform automated tasks on Grids on behalf of users. They are extremely useful for instance to automate grid service monitoring, data processing production, distributed data collection systems. Basically these certificates can be used to identify a person responsible for an unattended service or process acting as client and/or server. Robot certificates can be installed on a smart card and used behind a portal by everyone interested in running the related applications in a Grid environment using a user-friendly graphic interface. In this work, the GENIUS Grid Portal, powered by EnginFrame, has been extended in order to support the new authentication based on the adoption of these robot certificates. Results The work carried out and reported in this manuscript is particularly relevant for all users who are not familiar with personal digital certificates and the technical aspects of the Grid Security Infrastructure (GSI). The valuable benefits introduced by robot certificates in e-Science can so be extended to users belonging to several scientific domains, providing an asset in raising Grid awareness to a wide number of potential users. Conclusion The adoption of Grid portals extended with robot certificates, can really

Dual PI3K/mTOR inhibitors induce rapid over-activation of the MEK/ERK pathway in human pancreatic cancer cells through suppression of mTORC2

PubMed Central

Soares, Heloisa P.; Ming, Ming; Mellon, Michelle; Young, Steven H.; Han, Liang; Sinnet-Smith, James; Rozengurt, Enrique

2015-01-01

PI3K/AKT/mTOR pathway which is aberrantly stimulated in many cancer cells, has emerged as a target for therapy. However, mTORC1/S6K also mediates negative feedback loops that attenuate upstream signaling. Suppression of these feedback loops opposes the growth-suppressive effects of mTOR inhibitors and leads to drug resistance. Here, we demonstrate that treatment of PANC-1 or MiaPaCa-2 pancreatic ductal adenocarcinoma (PDAC) cells with the dual PI3K/mTOR kinase inhibitor (PI3K/TOR-KI) NPV-BEZ235 blocked mTORC1/S6K activation (scored by S6 phosphorylation at Ser240/244), mTORC1/4E-BP1 (assayed by 4E-BP1 phosphorylation at Thr37/46) and mTORC2-mediated AKT phosphorylation at Ser473, in a concentration-dependent manner. Strikingly, NPV-BEZ235 markedly enhanced the MEK/ERK pathway in a dose-dependent manner. Maximal ERK over-activation coincided with complete inhibition of phosphorylation of AKT and 4E-BP1. ERK over-activation was induced by other PI3K/TOR-KIs, including PKI-587 and GDC-0980. The MEK inhibitors U126 or PD0325901 prevented ERK over-activation induced by PI3K/TOR-KIs. The combination of NPV-BEZ235 and PD0325901 caused a more pronounced inhibition of cell growth than that produced by each inhibitor individually. Mechanistic studies assessing PI3K activity in single PDAC cells indicate that PI3K/TOR-KIs act through a PI3K-independent pathway. Doses of PI3K/TOR-KIs that enhanced MEK/ERK activation coincided with those that inhibited mTORC2-mediated AKT phosphorylation on Ser473, suggesting a role of mTORC2. Knockdown of Rictor via transfection of siRNA markedly attenuated the enhancing effect of NVP-BEZ235 on ERK phosphorylation. We propose that dual PI3K/mTOR inhibitors suppress a novel negative feedback loop mediated by mTORC2 thereby leading to enhanced MEK/ERK pathway activity in pancreatic cancer cells. PMID:25673820

The GENIUS Grid Portal and robot certificates: a new tool for e-Science.

PubMed

Barbera, Roberto; Donvito, Giacinto; Falzone, Alberto; La Rocca, Giuseppe; Milanesi, Luciano; Maggi, Giorgio Pietro; Vicario, Saverio

2009-06-16

Grid technology is the computing model which allows users to share a wide pletora of distributed computational resources regardless of their geographical location. Up to now, the high security policy requested in order to access distributed computing resources has been a rather big limiting factor when trying to broaden the usage of Grids into a wide community of users. Grid security is indeed based on the Public Key Infrastructure (PKI) of X.509 certificates and the procedure to get and manage those certificates is unfortunately not straightforward. A first step to make Grids more appealing for new users has recently been achieved with the adoption of robot certificates. Robot certificates have recently been introduced to perform automated tasks on Grids on behalf of users. They are extremely useful for instance to automate grid service monitoring, data processing production, distributed data collection systems. Basically these certificates can be used to identify a person responsible for an unattended service or process acting as client and/or server. Robot certificates can be installed on a smart card and used behind a portal by everyone interested in running the related applications in a Grid environment using a user-friendly graphic interface. In this work, the GENIUS Grid Portal, powered by EnginFrame, has been extended in order to support the new authentication based on the adoption of these robot certificates. The work carried out and reported in this manuscript is particularly relevant for all users who are not familiar with personal digital certificates and the technical aspects of the Grid Security Infrastructure (GSI). The valuable benefits introduced by robot certificates in e-Science can so be extended to users belonging to several scientific domains, providing an asset in raising Grid awareness to a wide number of potential users. The adoption of Grid portals extended with robot certificates, can really contribute to creating transparent access to

The effect of PKA-mediated phosphorylation of ryanodine receptor on SR Ca2+ leak in ventricular myocytes.

PubMed

Bovo, Elisa; Huke, Sabine; Blatter, Lothar A; Zima, Aleksey V

2017-03-01

Functional impact of cardiac ryanodine receptor (type 2 RyR or RyR2) phosphorylation by protein kinase A (PKA) remains highly controversial. In this study, we characterized a functional link between PKA-mediated RyR2 phosphorylation level and sarcoplasmic reticulum (SR) Ca 2+ release and leak in permeabilized rabbit ventricular myocytes. Changes in cytosolic [Ca 2+ ] and intra-SR [Ca 2+ ] SR were measured with Fluo-4 and Fluo-5N, respectively. Changes in RyR2 phosphorylation at two PKA sites, serine-2031 and -2809, were measured with phospho-specific antibodies. cAMP (10μM) increased Ca 2+ spark frequency approximately two-fold. This effect was associated with an increase in SR Ca 2+ load from 0.84 to 1.24mM. PKA inhibitory peptide (PKI; 10μM) abolished the cAMP-dependent increase of SR Ca 2+ load and spark frequency. When SERCA was completely blocked by thapsigargin, cAMP did not affect RyR2-mediated Ca 2+ leak. The lack of a cAMP effect on RyR2 function can be explained by almost maximal phosphorylation of RyR2 at serine-2809 after sarcolemma permeabilization. This high RyR2 phosphorylation level is likely the consequence of a balance shift between protein kinase and phosphatase activity after permeabilization. When RyR2 phosphorylation at serine-2809 was reduced to its "basal" level (i.e. RyR2 phosphorylation level in intact myocytes) using kinase inhibitor staurosporine, SR Ca 2+ leak was significantly reduced. Surprisingly, further dephosphorylation of RyR2 with protein phosphatase 1 (PP1) markedly increased SR Ca 2+ leak. At the same time, phosphorylation of RyR2 at serine 2031 did not significantly change under identical experimental conditions. These results suggest that RyR2 phosphorylation by PKA has a complex effect on SR Ca 2+ leak in ventricular myocytes. At an intermediate level of RyR2 phosphorylation SR Ca 2+ leak is minimal. However, complete dephosphorylation and maximal phosphorylation of RyR2 increases SR Ca 2+ leak. Copyright © 2017 Elsevier

Identification of Dmt-D-Lys-Phe-Phe-OH as a highly antinociceptive tetrapeptide metabolite of the opioid-neurotensin hybrid peptide PK20.

PubMed

Kleczkowska, Patrycja; Bojnik, Engin; Leśniak, Anna; Kosson, Piotr; Van den Eynde, Isabelle; Ballet, Steven; Benyhe, Sandor; Tourwé, Dirk; Lipkowski, Andrzej W

2013-01-01

Recently, we presented a novel compound (PK20, Dmt-D-Lys-Phe-Phe-Lys-Lys-Pro-Phe-Tle-Leu-OH) that targets single entity opioid and neurotensin pharmacophores. This endomorphin-2-like opioid peptide was introduced as a highly active analgesic because it elicited a strong dose- and time-dependent antinociceptive response when administered centrally and peripherally. Its pain-relieving activity was observed as rapidly as 5 min after drug injection. Such promising results led us to perform further studies, such as determining the resistance to enzymatic degradation, which resulted in obtaining a very stable opioid pharmacore PK20 metabolite. The synthesis of PK20 and its N-terminal tetrapeptide fragment has been accomplished using solid phase peptide chemistry. The biological stability of peptides has been measured in human serum and analyzed by HPLC/MS. Peptides were pharmacologically characterized in in vitro MOP and DOP receptor binding as well as [(35)S]GTPγS receptor binding assays. Antinociceptive properties of compounds were measured by in vivo assays in C57Bl6 mice after intravenous or intrathecal applications. Dmt-D-Lys-Phe-Phe-OH (PK20M), an N-terminal tetrapeptide metabolite of the opioid-neurotensin hybrid peptide PK20, is characterized by a long duration of action, as demonstrated by a preserved, long-lasting analgesic effect even 2 h post-injection (average % MPE = 69.33). In rat brain membranes, PK20M efficiently displaced both the MOP and DOP receptor selective radioprobes [(3)H]DAMGO and [(3)H]DIDI (pKi of 9.52 and 7.86, respectively) and potently stimulated [(35)S]GTPγS binding, proving full agonism at both receptor types. In the [(35)S]GTPγS assay, which measured the agonist-mediated G protein activation, PK20M together with PK20 and Met-enkephalin were potent stimulators of the regulatory G proteins. The relative affinities of PK20M for the μ and δ receptor subtypes revealed μ-receptor selectivity. The novel MOP receptor selective metabolite

Seismic velocity and attenuation structures in the Earth's inner core

NASA Astrophysics Data System (ADS)

Yu, Wen-Che

2007-12-01

I study seismic velocity and attenuation structures in the top 400 km of the Earth's inner core along equatorial paths, velocity-attenuation relationship, and seismic anisotropy in the top of the inner core beneath Africa. Seismic observations exhibit "east-west" hemispheric differences in seismic velocity, attenuation, and anisotropy. Joint modeling of the PKiKP-PKIKP and PKPbc-PKIKP phases is used to constrain seismic velocity and attenuation structures in the top 400 km of the inner core for the eastern and western hemispheres. The velocity and attenuation models for the western hemisphere are simple, having a constant velocity gradient and a Q value of 600 in the top 400 km of the inner core. The velocity and attenuation models for the eastern hemisphere appear complex. The velocity model for the eastern hemisphere has a small velocity gradient in the top 235 km, a steeper velocity gradient at the depth range of 235 - 375 km, and a gradient similar to PREM in the deeper portion of the inner core. The attenuation model for the eastern hemisphere has a Q value of 300 in the top 300 km and a Q value of 600 in the deeper portion of the inner core. The study of velocity-attenuation relationship reveals that inner core is anisotropic in both velocity and attenuation, and the direction of high attenuation corresponding to that of high velocity. I hypothesize that the hexagonal close packed (hcp) iron crystal is anisotropic in attenuation, with the axis of high attenuation corresponding to that of high velocity. Anisotropy in the top of the inner core beneath Africa is complex. Beneath eastern Africa, the thickness of the isotropic upper inner core is about 0 km. Beneath central and western Africa, the thickness of the isotropic upper inner core increases from 20 to 50 km. The velocity increase across the isotropic upper inner core and anisotropic lower inner core boundary is sharp, laterally varying from 1.6% - 2.2%. The attenuation model has a Q value of 600 for the

GW627368X ((N-{2-[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetyl} benzene sulphonamide): a novel, potent and selective prostanoid EP4 receptor antagonist

PubMed Central

Wilson, Richard J; Giblin, Gerard M P; Roomans, Susan; Rhodes, Sharron A; Cartwright, Kerri-Ann; Shield, Vanessa J; Brown, Jason; Wise, Alan; Chowdhury, Jannatara; Pritchard, Sara; Coote, Jim; Noel, Lloyd S; Kenakin, Terry; Burns-Kurtis, Cynthia L; Morrison, Valerie; Gray, David W; Giles, Heather

2006-01-01

N-{2-[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetyl}benzene sulphonamide (GW627368X) is a novel, potent and selective competitive antagonist of prostanoid EP4 receptors with additional human TP receptor affinity. At recombinant human prostanoid EP4 receptors expressed in HEK293 cells, GW627368X produced parallel rightward shifts of PGE2 concentration–effect (E/[A]) curves resulting in an affinity (pKb) estimate of 7.9±0.4 and a Schild slpoe not significantly different from unity. The affinity was independent of the agonist used. In rings of phenylephrine precontracted piglet saphenous vein, GW627368X (30–300 nM) produced parallel rightward displacement of PGE2 E/[A] curves (pKb=9.2±0.2; slope=1). GW627368X appears to bind to human prostanoid TP receptors but not the TP receptors of other species. In human washed platelets, GW627368X (10 μM) produced 100% inhibition of U-46619 (EC100)-induced aggregation (approximate pA2 ∼7.0). However, in rings of rabbit and piglet saphenous vein and of guinea-pig aorta GW627368X (10 μM) did not displace U-46619 E/[A] curves indicating an affinity of <5.0 for rabbit and guinea-pig prostanoid TP receptors. In functional assays GW627368X is devoid of both agonism and antagonist affinity for prostanoid CRTH2, EP2, EP3, IP and FP receptors. At prostanoid EP1 receptors, GW627368X was an antagonist with a pA2 of 6.0, and at prostanoid IP receptors the compound increased the maximum effect of iloprost by 55%. At rabbit prostanoid EP2 receptors the pA2 of GW627368X was <5.0. In competition radioligand bioassays, GW627368X had affinity for human prostanoid EP4 and TP receptors (pKi=7.0±0.2 (n=10) and 6.8 (n=2), respectively). Affinity for all other human prostanoid receptors was <5.3. GW627368X will be a valuable tool to explore the role of the prostanoid EP4 receptor in many physiological and pathological settings. PMID:16604093

Nuclear Physics Science Network Requirements Workshop, May 2008 - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tierney, Ed., Brian L; Dart, Ed., Eli; Carlson, Rich

2008-11-10

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the US Department of Energy Office of Science, the single largest supporter of basic research in the physical sciences in the United States of America. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 20 years. In May 2008, ESnet and the Nuclear Physics (NP) Program Office of the DOEmore » Office of Science organized a workshop to characterize the networking requirements of the science programs funded by the NP Program Office. Most of the key DOE sites for NP related work will require significant increases in network bandwidth in the 5 year time frame. This includes roughly 40 Gbps for BNL, and 20 Gbps for NERSC. Total transatlantic requirements are on the order of 40 Gbps, and transpacific requirements are on the order of 30 Gbps. Other key sites are Vanderbilt University and MIT, which will need on the order of 20 Gbps bandwidth to support data transfers for the CMS Heavy Ion program. In addition to bandwidth requirements, the workshop emphasized several points in regard to science process and collaboration. One key point is the heavy reliance on Grid tools and infrastructure (both PKI and tools such as GridFTP) by the NP community. The reliance on Grid software is expected to increase in the future. Therefore, continued development and support of Grid software is very important to the NP science community. Another key finding is that scientific productivity is greatly enhanced by easy researcher-local access to instrument data. This is driving the creation of distributed repositories for instrument data at collaborating institutions, along with a corresponding increase in demand for network-based data transfers and the

Naftopidil inhibits 5-hydroxytryptamine-induced bladder contraction in rats.

PubMed

Sakai, Takumi; Kasahara, Ken-ichi; Tomita, Ken-ichi; Ikegaki, Ichiro; Kuriyama, Hiroshi

2013-01-30

Naftopidil is an α(1D) and α(1A) subtype-selective α(1)-adrenoceptor antagonist that has been used to treat lower urinary tract symptoms of benign prostatic hyperplasia. In this study, we investigated the effects of naftopidil on 5-hydroxytryptamine (5-HT)-induced rat bladder contraction (10(-8)-10(-4) M). Naftopidil (0.3, 1, and 3 μM) inhibited 5-HT-induced bladder contraction in a concentration-dependent manner. On the other hand, other α(1)-adrenoceptor antagonists, tamsulosin, silodosin or prazosin, did not inhibit 5-HT-induced bladder contraction. The 5-HT-induced bladder contraction was inhibited by both ketanserin and 4-(4-fluoronaphthalen-1-yl)-6-propan-2-ylpyrimidin-2-amine (RS127445), serotonin 5-HT(2A) and 5-HT(2B) receptor antagonists, respectively. In addition, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and α-methyl-5-HT, 5-HT(2A) and 5-HT(2) receptor agonists, respectively, induced bladder contraction. The 5-HT-induced bladder contraction was not inhibited by N-[2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl]-N-pyridin-2-yl-cyclohexanecarboxamide (WAY-100635), [1-[2[(methylsulfonyl)amino]ethyl]-4-piperidinyl]methyl-1-methyl-1H-indole-3-carboxylate (GR113808) or (R)-3-[2-[2-(4-methylpiperidin-1-yl)ethyl]pyrrolidine-1-sulphonyl]phenol (SB269970), 5-HT(1A), 5-HT(4) and 5-HT(7) receptor antagonists, respectively. Naftopidil inhibited both the 5-HT(2A) and 5-HT(2) receptor agonists-induced bladder contractions. Naftopidil binds to the human 5-HT(2A) and 5-HT(2B) receptors with pKi values of 6.55 and 7.82, respectively. These results suggest that naftopidil inhibits 5-HT-induced bladder contraction via blockade of the 5-HT(2A) and 5-HT(2B) receptors in rats. Furthermore, 5-HT-induced bladder contraction was enhanced in bladder strips obtained from bladder outlet obstructed rats, with this contraction inhibited by naftopidil. The beneficial effects of naftopidil on storage symptoms such as urinary frequency and nocturia in patients with benign

Imidazoquinolinone, imidazopyridine, and isoquinolindione derivatives as novel and potent inhibitors of the poly(ADP-ribose) polymerase (PARP): a comparison with standard PARP inhibitors.

PubMed

Eltze, Tobias; Boer, Rainer; Wagner, Thomas; Weinbrenner, Steffen; McDonald, Michelle C; Thiemermann, Christoph; Bürkle, Alexander; Klein, Thomas

2008-12-01

We have identified three novel structures for inhibitors of the poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA and implicated in DNA repair, apoptosis, organ dysfunction or necrosis. 2-[4-(5-Methyl-1H-imidazol-4-yl)-piperidin-1-yl]-4,5-dihydro-imidazo[4,5,1-i,j]quinolin-6-one (BYK49187), 2-(4-pyridin-2-yl-phenyl)-4,5-dihydro-imidazo[4,5,1-i,j]quinolin-6-one (BYK236864), 6-chloro-8-hydroxy-2,3-dimethyl-imidazo-[1,2-alpha]-pyridine (BYK20370), and 4-(1-methyl-1H-pyrrol-2-ylmethylene)-4H-isoquinolin-1,3-dione (BYK204165) inhibited cell-free recombinant human PARP-1 with pIC(50) values of 8.36, 7.81, 6.40, and 7.35 (pK(i) 7.97, 7.43, 5.90, and 7.05), and murine PARP-2 with pIC(50) values of 7.50, 7.55, 5.71, and 5.38, respectively. BYK49187, BYK236864, and BYK20370 displayed no selectivity for PARP-1/2, whereas BYK204165 displayed 100-fold selectivity for PARP-1. The IC(50) values for inhibition of poly(ADP-ribose) synthesis in human lung epithelial A549 and cervical carcinoma C4I cells as well in rat cardiac myoblast H9c2 cells after PARP activation by H(2)O(2) were highly significantly correlated with those at cell-free PARP-1 (r(2) = 0.89-0.96, P < 0.001) but less with those at PARP-2 (r(2) = 0.78-0.84, P < 0.01). The infarct size caused by coronary artery occlusion and reperfusion in the anesthetized rat was reduced by 22% (P < 0.05) by treatment with BYK49187 (3 mg/kg i.v. bolus and 3 mg/kg/h i.v. during 2-h reperfusion), whereas the weaker PARP inhibitors, BYK236864 and BYK20370, were not cardioprotective. In conclusion, the imidazoquinolinone BYK49187 is a potent inhibitor of human PARP-1 activity in cell-free and cellular assays in vitro and reduces myocardial infarct size in vivo. The isoquinolindione BYK204165 was found to be 100-fold more selective for PARP-1. Thus, both compounds might be novel and valuable tools for investigating PARP-1-mediated effects.

Land Cover Change Community-based Processing and Analysis System (LC-ComPS): Lessons Learned from Technology Infusion

NASA Astrophysics Data System (ADS)

Masek, J.; Rao, A.; Gao, F.; Davis, P.; Jackson, G.; Huang, C.; Weinstein, B.

2008-12-01

The Land Cover Change Community-based Processing and Analysis System (LC-ComPS) combines grid technology, existing science modules, and dynamic workflows to enable users to complete advanced land data processing on data available from local and distributed archives. Changes in land cover represent a direct link between human activities and the global environment, and in turn affect Earth's climate. Thus characterizing land cover change has become a major goal for Earth observation science. Many science algorithms exist to generate new products (e.g., surface reflectance, change detection) used to study land cover change. The overall objective of the LC-ComPS is to release a set of tools and services to the land science community that can be implemented as a flexible LC-ComPS to produce surface reflectance and land-cover change information with ground resolution on the order of Landsat-class instruments. This package includes software modules for pre-processing Landsat-type satellite imagery (calibration, atmospheric correction, orthorectification, precision registration, BRDF correction) for performing land-cover change analysis and includes pre-built workflow chains to automatically generate surface reflectance and land-cover change products based on user input. In order to meet the project objectives, the team created the infrastructure (i.e., client-server system with graphical and machine interfaces) to expand the use of these existing science algorithm capabilities in a community with distributed, large data archives and processing centers. Because of the distributed nature of the user community, grid technology was chosen to unite the dispersed community resources. At that time, grid computing was not used consistently and operationally within the Earth science research community. Therefore, there was a learning curve to configure and implement the underlying public key infrastructure (PKI) interfaces, required for the user authentication, secure file

Kynurenic acid analogues with improved affinity and selectivity for the glycine site on the N-methyl-D-aspartate receptor from rat brain.

PubMed

Foster, A C; Kemp, J A; Leeson, P D; Grimwood, S; Donald, A E; Marshall, G R; Priestley, T; Smith, J D; Carling, R W

1992-05-01

The glycine site on the N-methyl-D-aspartate (NMDA) subtype of receptors for the excitatory neurotransmitter glutamate is a potential target for the development of neuroprotective drugs. We report here two chemical series of glycine site antagonists derived from kynurenic acid (KYNA), with greatly improved potency and selectivity. Disubstitution with chlorine or bromine in the 5- and 7-positions of KYNA increased affinity for [3H]glycine binding sites in rat cortex/hippocampus P2 membranes, with a parallel increase of potency for antagonism of NMDA-evoked responses in the rat cortical wedge preparation. The optimal compound was 5-I,7-Cl-KYNA, with an IC50 for [3H]glycine binding of 29 nM and an apparent Kb in the cortical wedge preparation of 0.41 microM. Reduction of the right-hand ring of 5,7-diCl-KYNA reduced affinity by 10-fold, but this was restored by substitution in the 4-position with the trans-phenylamide and further improved in the trans-benzylamide. The optimal compound was the transphenylurea (L-689,560), with an IC50 of 7.4 nM and an apparent Kb of 0.13 microM. Both series of compounds displayed a high degree of selectivity for the glycine site, having IC50 values of greater than 10 microM versus radioligand binding to the glutamate recognition sites of NMDA, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), and kainate receptors and the strychnine-sensitive glycine receptor. Selectivity versus AMPA receptor-mediated responses was also apparent in the rat cortical wedge and in patch-clamp recordings of cortical neurons in culture. Experiments using [3H]dizocilpine (MK-801) binding indicated that 5,7-diBr-KYNA, 5,7-diCl-KYNA, 5-I,7-Cl-KYNA, and L-689,560 all behaved as full antagonists and were competitive with glycine. Patch-clamp recordings of cortical neurons in culture also indicated that NMDA-induced currents were antagonized by competition for the glycine site, and gave no evidence for partial agonist activity. pKi values for 5,7-di

Inferences on the Physical Nature of Earth's Inner Core Boundary Region from Observations of Antipodal PKIKP and PKIIKP Waves

NASA Astrophysics Data System (ADS)

Cormier, V. F.; Attanayake, J.; Thomas, C.; Koper, K. D.; Miller, M. S.

2017-12-01

The Earth's Inner Core Boundary (ICB) is considered a uniform and sharp liquid-to-solid transition in standard Earth models such as PREM and AK135-F. By analysing seismic wave reflections emanating from the ICB, this hypothesis of a simple ICB can be tested. Observed absolute and relative amplitudes and coda of the PKiKP phase that is reflected on the topside of the ICB suggest that the ICB is neither uniform nor has a simple structure. Similarly, waves that are reflected from the underside of the ICB - PKIIKP phase - can be used to determine the physical nature of the region immediately below the ICB. Using high-frequency synthetic waveform experiments, we confirm that antipodal PKIIKP amplitudes can discriminate the state of the uppermost 10 km of the inner core: A standard liquid-to-solid ICB (high shear velocity/shear modulus discontinuity) produces a maximum PKIIKP amplitude equal to only a factor of 0.14 of the PKIKP amplitude, whereas a non-standard liquid-to-near liquid ICB (low shear velocity/shear modulus discontinuity) can produce PKIIKP amplitudes comparable to PKIKP. We searched for PKIIKP in individual and stacked array waveforms in the 170° - 180° distance range for the 2000 to 2016 time period globally to compare with our synthetic results. We attribute a lack of PKIIKP detection in the stacked array recordings due to (1) ranges closer to 170° and not 180°, where the PKIIKP signal-to-noise ratio is very poor; (2) scattered coda following PKIKP masking the PKIIKP phase; and (3) large azimuthal variations of array recordings closer to 180° preventing the formation of an accurate beam. Envelopes of individual recordings in the 178° - 180° distance range, however, clearly show energy peaks correlating with the travel time of PKIIKP phase. Our global set of PKIIKP/PKIKP energy ratio measurements vary between 0.1 and 1.1, indicating significant structural complexity immediately below the ICB. While a complex inner core anisotropy structure and ICB

The role of small molecule platelet-derived growth factor receptor (PDGFR) inhibitors in the treatment of neoplastic disorders.

PubMed

Roskoski, Robert

2018-03-01

Platelet-derived growth factor (PDGF) was discovered as a serum-derived component necessary for the growth of smooth muscle cells, fibroblasts, and glial cells. The PDGF family is a product of four gene products and consists of five dimeric isoforms: PDGF-AA, PDGF-BB, PDGF-CC, PDGF-DD, and the PDGF-AB heterodimer. This growth factor family plays an essential role in embryonic development and in wound healing in the adult. These growth factors mediate their effects by binding to and activating their receptor protein-tyrosine kinases, which are encoded by two genes: PDGFRA and PDGFRB. The functional receptors consist of the PDGFRα/α and PDGFRβ/β homodimers and the PDGFRα/β heterodimer. Although PDGF signaling is most closely associated with mesenchymal cells, PDGFs and PDGF receptors are widely expressed in the mammalian central nervous system. The PDGF receptors contain an extracellular domain that is made up of five immunoglobulin-like domains (Ig-d1/2/3/4/5), a transmembrane segment, a juxtamembrane segment, a protein-tyrosine kinase domain that contains an insert of about 100 amino acid residues, and a carboxyterminal tail. Although uncommon, activating mutations in the genes for PDGF or PDGF receptors have been documented in various neoplasms including dermatofibrosarcoma protuberans (DFSP) and gastrointestinal stromal tumors (GIST). In most neoplastic diseases, PDGF expression and action appear to involve the tumor stroma. Moreover, this family is pro-angiogenic. More than ten PDGFRα/β multikinase antagonists have been approved by the FDA for the treatment of several neoplastic disorders and interstitial pulmonary fibrosis (www.brimr.org/PKI/PKIs.htm). Type I protein kinase inhibitors interact with the active enzyme form with DFG-D of the proximal activation segment directed inward toward the active site (DFG-D in ). In contrast, type II inhibitors bind to their target with the DFG-D pointing away from the active site (DFG-D out ). We used the Schr

The 6th International Conference on Computer Science and Computational Mathematics (ICCSCM 2017)

NASA Astrophysics Data System (ADS)

2017-09-01

The ICCSCM 2017 (The 6th International Conference on Computer Science and Computational Mathematics) has aimed to provide a platform to discuss computer science and mathematics related issues including Algebraic Geometry, Algebraic Topology, Approximation Theory, Calculus of Variations, Category Theory; Homological Algebra, Coding Theory, Combinatorics, Control Theory, Cryptology, Geometry, Difference and Functional Equations, Discrete Mathematics, Dynamical Systems and Ergodic Theory, Field Theory and Polynomials, Fluid Mechanics and Solid Mechanics, Fourier Analysis, Functional Analysis, Functions of a Complex Variable, Fuzzy Mathematics, Game Theory, General Algebraic Systems, Graph Theory, Group Theory and Generalizations, Image Processing, Signal Processing and Tomography, Information Fusion, Integral Equations, Lattices, Algebraic Structures, Linear and Multilinear Algebra; Matrix Theory, Mathematical Biology and Other Natural Sciences, Mathematical Economics and Financial Mathematics, Mathematical Physics, Measure Theory and Integration, Neutrosophic Mathematics, Number Theory, Numerical Analysis, Operations Research, Optimization, Operator Theory, Ordinary and Partial Differential Equations, Potential Theory, Real Functions, Rings and Algebras, Statistical Mechanics, Structure Of Matter, Topological Groups, Wavelets and Wavelet Transforms, 3G/4G Network Evolutions, Ad-Hoc, Mobile, Wireless Networks and Mobile Computing, Agent Computing & Multi-Agents Systems, All topics related Image/Signal Processing, Any topics related Computer Networks, Any topics related ISO SC-27 and SC- 17 standards, Any topics related PKI(Public Key Intrastructures), Artifial Intelligences(A.I.) & Pattern/Image Recognitions, Authentication/Authorization Issues, Biometric authentication and algorithms, CDMA/GSM Communication Protocols, Combinatorics, Graph Theory, and Analysis of Algorithms, Cryptography and Foundation of Computer Security, Data Base(D.B.) Management & Information

Muscarinic receptor subtypes involved in carbachol-induced contraction of mouse uterine smooth muscle.

PubMed

Kitazawa, Takio; Hirama, Ryuichi; Masunaga, Kozue; Nakamura, Tatsuro; Asakawa, Koichi; Cao, Jinshan; Teraoka, Hiroki; Unno, Toshihiro; Komori, Sei-ichi; Yamada, Masahisa; Wess, Jürgen; Taneike, Tetsuro

2008-06-01

Functional muscarinic acetylcholine receptors present in the mouse uterus were characterized by pharmacological and molecular biological studies using control (DDY and wild-type) mice, muscarinic M2 or M3 single receptor knockout (M2KO, M3KO), and M2 and M3 receptor double knockout mice (M2/M3KO). Carbachol (10 nM-100 microM) increased muscle tonus and phasic contractile activity of uterine strips of control mice in a concentration-dependent manner. The maximum carbachol-induced contractions (Emax) differed between cervical and ovarian regions of the uterus. The stage of the estrous cycle had no significant effect on carbachol concentration-response relationships. Tetrodotoxin did not decrease carbachol-induced contractions, but the muscarinic receptor antagonists (11-[[2-[(diethylaminomethyl)-1-piperidinyl]acetyl]-5,11-dihydro-6H-pyrido[2,3-b[2,3-b][1,4]benzodiazepin6-one (AF-DX116), N-[2-[2-[(dipropylamino)methyl]-1-piperidinyl]ethyl]-5,6-dihydro-6-oxo-11H-pyrido[2,3-b][1,4] benzodiazepine-11-carboxamide (AF-DX384), 4-diphenylacetoxy-N-methyl-piperidine(4-DAMP), para-fluoro-hexa hydro-sila-diphenidol (p-F-HHSiD), himbacine, methoctramine, pirenzepine, and tropicamide) inhibited carbachol-induced contractions in a competitive fashion. The pKb values for these muscarinic receptor antagonists correlated well with the known pKi values of these antagonists for the M3 muscarinic receptor. In uterine strips isolated from mice treated with pertussis toxin (100 microg/kg, i.p. for 96 h), Emax values for carbachol were significantly decreased, but effective concentration that caused 50% of Emax values (EC50) remained unchanged. In uterine strips treated with 4-DAMP mustard (30 nM) and AF-DX116 (1 microM), followed by subsequent washout of AF-DX116, neither carbachol nor N,N,N,-trimethyl-4-(2-oxo-1-pyrolidinyl)-2-butyn-1-ammonium iodide (oxotremorine-M) caused any contractile responses. Both M2 and M3 muscarinic receptor messenger RNAs were detected in the mouse uterus via

Mechanism of Ca2+-influx and Ca2+/calmodulin-dependent protein kinase IV activity during in utero hypoxia in cerebral cortical neuronal nuclei of the guinea pig fetus at term.

PubMed

Vibert, Yanick M; Ashraf, Qazi M; Mishra, Om P; Delivoria-Papadopoulos, Maria

2008-08-08

Previously we showed that following hypoxia there is an increase in nuclear Ca(2+)-influx and Ca(2+)/calmodulin-dependent protein kinase IV activity (CaMK IV) in the cerebral cortex of term guinea pig fetus. The present study tests the hypothesis that clonidine administration will prevent hypoxia-induced increased neuronal nuclear Ca(2+)-influx and increased CaMK IV activity, by blocking high-affinity Ca(2+)-ATPase. Studies were conducted in 18 pregnant guinea pigs at term, normoxia (Nx, n=6), hypoxia (Hx, n=6) and clonidine with Hx (Hx+Clo, n=6). The pregnant guinea pig was exposed to a decreased FiO(2) of 0.07 for 60 min. Clonidine, an imidazoline inhibitor of high-affinity Ca(2+)-ATPase, was administered 12.5 microg/kg IP 30 min prior to hypoxia. Hypoxia was determined biochemically by ATP and phosphocreatine (PCr) levels. Nuclei were isolated and ATP-dependent (45)Ca(2+)-influx was determined. CaMK IV activity was determined by (33)P-incorporation into syntide 2 for 2 min at 37 degrees C in a medium containing 50mM HEPES (pH 7.5), 2mM DTT, 40muM syntide 2, 0.2mM (33)P-ATP, 10mM magnesium acetate, 5 microM PKI 5-24, 2 microM PKC 19-36 inhibitor peptides, 1 microM microcystine LR, 200 microM sodium orthovanadate and either 1mM EGTA (for CaMK IV-independent activity) or 0.8mM CaCl(2) and 1mM calmodulin (for total activity). ATP (mumoles/gbrain) values were significantly different in the Nx (4.62+/-0.2), Hx (1.65+/-0.2, p<0.05 vs. Nx), and Hx+Clo (1.92+/-0.6, p<0.05 vs. Nx). PCr (mumoles/g brain) values in the Nx (3.9+/-0.1), Hx (1.10+/-0.3, p<0.05 vs. Nx), and Hx+Clo (1.14+/-0.3, p<0.05 vs. Nx). There was a significant difference between nuclear Ca(2+)-influx (pmoles/mg protein/min) in Nx (3.98+/-0.4), Hx (10.38+/-0.7, p<0.05 vs. Nx), and Hx+Clo (7.35+/-0.9, p<0.05 vs. Nx, p<0.05 vs. Hx), and CaM KIV (pmoles/mg protein/min) in Nx (1314.00+/-195.4), Hx (2315.14+/-148.5, p<0.05 vs. Nx), and Hx+Clo (1686.75+/-154.3, p<0.05 vs. Nx, p<0.05 vs. Hx). We conclude that the

Applying the Earth System Grid Security System in a Heterogeneous Environment of Data Access Services

NASA Astrophysics Data System (ADS)

Kershaw, Philip; Lawrence, Bryan; Lowe, Dominic; Norton, Peter; Pascoe, Stephen

2010-05-01

CEDA (Centre for Environmental Data Archival) based at STFC Rutherford Appleton Laboratory is host to the BADC (British Atmospheric Data Centre) and NEODC (NERC Earth Observation Data Centre) with data holdings of over half a Petabyte. In the coming months this figure is set to increase by over one Petabyte through the BADC's role as one of three data centres to host the CMIP5 (Coupled Model Intercomparison Project Phase 5) core archive of climate model data. Quite apart from the problem of managing the storage of such large volumes there is the challenge of collating the data together from the modelling centres around the world and enabling access to these data for the user community. An infrastructure to support this is being developed under the US Earth System Grid (ESG) and related projects bringing together participating organisations together in a federation. The ESG architecture defines Gateways, the web interfaces that enable users to access data and data serving applications organised into Data Nodes. The BADC has been working in collaboration with US Earth System Grid team and other partners to develop a security system to restrict access to data. This provides single sign-on via both OpenID and PKI based means and uses role based authorisation facilitated by SAML and OpenID based interfaces for attribute retrieval. This presentation will provide an overview of the access control architecture and look at how this has been implemented for CEDA. CEDA has developed an expertise in data access and information services over several years through a number of projects to develop and enhance these capabilities. Participation in CMIP5 comes at a time when a number of other software development activities are coming to fruition. New services are in the process of being deployed alongside services making up the system for ESG. The security system must apply access control across this heterogeneous environment of different data services and technologies. One strand

Effective Sharing of Health Records, Maintaining Privacy: A Practical Schema

PubMed Central

Neame, Roderick

2013-01-01

, context etc.). For added security, as well as for trustworthiness, a method of verifying authenticity, integrity and authorship is required, which can be provided using a public key infrastructure (PKI) for cryptography (2). The second part of the solution is to give control over record access and sharing to the patient (or their identified representative), enabling them to authorise access by providing the index and access keys to their records. This can be done using a token (fe.g. smart card) or a secure online index which holds these details: this serves to relieve the formal record keeper of responsibility for external access control and privacy (internal access control and privacy can remain an institutional responsibility). The third part of the solution is to process the content of the stored records such that there is a ‘plain English’ copy, as well as an electronic copy which is coded and marked up using XML tags for each data element to signify ‘type’ (e.g. administrative, financial, operational, clinical etc.) and sub-types (e.g. diagnosis, medication, procedure, investigation result etc.). This ensures that the recipient can always read the data using a basic browser, but can readily manipulate and re-arrange the data for display and storage if they have a more sophisticated installation. PMID:23923101

Effective sharing of health records, maintaining privacy: a practical schema.

PubMed

Neame, Roderick

2013-01-01

.). For added security, as well as for trustworthiness, a method of verifying authenticity, integrity and authorship is required, which can be provided using a public key infrastructure (PKI) for cryptography (2). The second part of the solution is to give control over record access and sharing to the patient (or their identified representative), enabling them to authorise access by providing the index and access keys to their records. This can be done using a token (fe.g. smart card) or a secure online index which holds these details: this serves to relieve the formal record keeper of responsibility for external access control and privacy (internal access control and privacy can remain an institutional responsibility). The third part of the solution is to process the content of the stored records such that there is a 'plain English' copy, as well as an electronic copy which is coded and marked up using XML tags for each data element to signify 'type' (e.g. administrative, financial, operational, clinical etc.) and sub-types (e.g. diagnosis, medication, procedure, investigation result etc.). This ensures that the recipient can always read the data using a basic browser, but can readily manipulate and re-arrange the data for display and storage if they have a more sophisticated installation.

Actions of alpha2 adrenoceptor ligands at alpha2A and 5-HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for alpha2A adrenoceptors.

PubMed

Newman-Tancredi, A; Nicolas, J P; Audinot, V; Gavaudan, S; Verrièle, L; Touzard, M; Chaput, C; Richard, N; Millan, M J

1998-08-01

This study examined the activity of chemically diverse alpha2 adrenoceptor ligands at recombinant human (h) and native rat (r) alpha2A adrenoceptors compared with 5-HT1A receptors. First, in competition binding experiments at h alpha2A and h5-HT1A receptors expressed in CHO cells, several compounds, including the antagonists 1-(2-pyrimidinyl)piperazine (1-PP), (+/-)-idazoxan, benalfocin (SKF 86466), yohimbine and RX 821,002, displayed preference for h alpha2A versus h5-HT1A receptors of only 1.4-, 3.6-, 4-, 10- and 11-fold, respectively (based on differences in pKi values). Clonidine, brimonidine (UK 14304), the benzopyrrolidine fluparoxan and the guanidines guanfacine and guanabenz exhibited intermediate selectivity (22- to 31-fold) for h alpha2A receptors. Only the antagonist atipamezole and the agonist dexmedetomidine (DMT) displayed high preference for alpha2 adrenoceptors (1290- and 91-fold, respectively). Second, the compounds were tested for their ability to induce h5-HT1A receptor-mediated G-protein activation, as indicated by the stimulation of [35S]GTPgammaS binding. All except atipamezole and RX 821,002 exhibited agonist activity, with potencies which correlated with their affinity for h5-HT1A receptors. Relative efficacies (Emax values) were 25-35% for guanabenz, guanfacine, WB 4101 and benalfocin, 50-65% for 1-PP, (+/-)-idazoxan and clonidine, and over 70% for fluparoxan, oxymetazoline and yohimbine (relative to 5-HT = 100%). Yohimbine-induced [35S]GTPgammaS binding was inhibited by the selective 5-HT1A receptor antagonist WAY 100,635. In contrast, RX 821,002 was the only ligand which exhibited antagonist activity at h5-HT1A receptors, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Atipamezole, which exhibited negligeable affinity for 5-HT1A receptors, was inactive. Third, the affinities for r alpha2A differed considerably from the affinities for h alpha2A receptors whereas the affinities for r5-HT1A differed much less from the affinities for h5-HT

Constraints on seismic anisotropy of the innermost inner core from observations of antipode PKIIKP phases

NASA Astrophysics Data System (ADS)

Niu, F.

2006-12-01

While the existence of seismic anisotropy in the inner core is well accepted, its magnitude and depth variations are still debated. Besides seismic anisotropy, there is growing evidence that suggests the top several hundred kilometers of the inner core exhibits a hemispherical variation in both velocity (the isotropic wave speed and the magnitude of anisotropy) and attenuation structure. When the PKIKP wave propagates through the uppermost ~400 km of the inner core and reaches a distance less than ~155°, there are two other phases, PKiKP and PKPbc, which have mantle ray paths very close to it. The former is a P wave that reflects off the inner-core boundary (ICB) and the latter is P wave that travels above the ICB. These two phases are usually used as reference phases to infer the uppermost structure of the inner core. As the result, the top ~400 km of the inner core is relatively well studied and its structure is well known. On the other hand to study the deeper ~800 km of the inner core, one must use PKIKP arrivals observed at greater distances where there is no regular phase can be used as a suitable reference phase to remove mantle anomalies. PKPab is sometime used as the reference, but it is generally considered to be a poor reference phase as it has a very different ray path from PKIPK in the mantle and it also travels along the core-mantle boundary (CMB) where very strong lateral heterogeneities are known to exist. Another approach is to use a 3D global mantle velocity model to correct the mantle anomalies in the PKIKP travel time residuals. Using this approach Ishii and Dziewonski (2002) found that the innermost ~300 km exhibits a distinct seismic anisotropy from the rest of body, which they used to argue that the Earth's center might have a unique early history in the core's formation and evolution. Here we report on an observation of the PKIIKP phase, an underside reflected P wave at the ICB, for both the major- and minor-arc ray paths. The major

Receptor specificity and trigemino-vascular inhibitory actions of a novel 5-HT1B/1D receptor partial agonist, 311C90 (zolmitriptan).

PubMed

Martin, G R; Robertson, A D; MacLennan, S J; Prentice, D J; Barrett, V J; Buckingham, J; Honey, A C; Giles, H; Moncada, S

1997-05-01

endogenous agonist 5-HT is explained by the additional presence of 5-HT2A receptors. 4. 311C90 displayed high affinity at human recombinant 5-HT1D (formerly 5-HT1D alpha) and 5-HT1B (formerly 5-HT1D beta) receptors in transfected CHO-K1 cell membranes (pIC50 values = 9.16 +/- 0.12 and 8.32 +/- 0.09, respectively). In intact cells, the drug produced concentration-dependent inhibition of forskolin-stimulated adenylyl cyclase (p[A50] = 9.9 and 9.5, respectively) achieving the same maximum effect as 5-HT. Excepting human recombinant 5-HT1A and 5-ht1F receptors at which the drug behaved as an agonist with modest affinity (pIC50 = 6.45 +/- 0.11 and 7.22 +/- 0.12, respectively), 311C90 exhibited low, or no detectable affinity (pKi or pKB < or = 5.5) at numerous other monoamine receptors, including other 5-HT receptor subtypes. 5. When administered to anaesthetized guinea-pigs ten minutes before unilateral electrical stimulation of the trigeminal ganglion (1.2 mA, 5 Hz, 5 ms, 5 min), 311C90 (3-30 micrograms kg-1, i.v.) caused a dose-dependent inhibition of [125I]-albumin extravasation within the ipsilateral dura mater. At the same doses, the drug also produced dose-dependent falls in cranial vascular conductance (32.3 +/- 7.5% at 30 micrograms kg-1), as measured in the ear by laser doppler flowmetry. 6. These results show that 311C90, a novel member of the 5-HT1B/1D agonist drug class, exhibits a high degree of pharmacological specificity. Its potent partial agonist action at "5-HT1B-like' receptors in intracranial arteries, coupled with potent agonism at 5-HT1D and 5-HT1B receptors and an ability to inhibit neurogenic plasma protein extravasation in the dura, are consistent with its utility as an effective acute treatment for migraine.

Rivers of Carbon: Carbon Fluxes in a Watershed Context

NASA Astrophysics Data System (ADS)

Wohl, E.; Tom, B.; Hovius, N.

2017-12-01

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