Authentication Without Secrets

Energy Technology Data Exchange (ETDEWEB)

Pierson, Lyndon G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-11-01

This work examines a new approach to authentication, which is the most fundamental security primitive that underpins all cyber security protections. Current Internet authentication techniques require the protection of one or more secret keys along with the integrity protection of the algorithms/computations designed to prove possession of the secret without actually revealing it. Protecting a secret requires physical barriers or encryption with yet another secret key. The reason to strive for "Authentication without Secret Keys" is that protecting secrets (even small ones only kept in a small corner of a component or device) is much harder than protecting the integrity of information that is not secret. Promising methods are examined for authentication of components, data, programs, network transactions, and/or individuals. The successful development of authentication without secret keys will enable far more tractable system security engineering for high exposure, high consequence systems by eliminating the need for brittle protection mechanisms to protect secret keys (such as are now protected in smart cards, etc.). This paper is a re-release of SAND2009-7032 with new figures numerous edits.

Distribution and diversity of bacterial secretion systems across metagenomic datasets.

Science.gov (United States)

Barret, Matthieu; Egan, Frank; O'Gara, Fergal

2013-02-01

Bacteria can manipulate their surrounding environment through the secretion of proteins into other living organisms and into the extracellular milieu. In Gram stain negative bacteria this process is mediated by different types of secretion systems from type I through type VI secretion system (T1SS-T6SS). In this study the prevalence of these secretion systems in 312 publicly available microbiomes derived from a wide range of ecosystems was investigated by a gene-centric approach. Our analysis demonstrates that some secretion systems are over-represented in some specific samples. In addition, some T3SS and T6SS phylogenetic clusters were specifically enriched in particular ecological niches, which could indicate specific bacterial adaptation to these environments. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Effects of X-irradiation on gonadotropin secretion in rat anterior pituitary cells

International Nuclear Information System (INIS)

Li Xinmin; Liu Shuzheng

1988-01-01

The dispersed rat anterior pituitary cells cultured in 3 days was exposed to single doses of X-irradiation in the range of 0.5-8.0 Gy. LH and FSH contents in both the supernatant and the cells were measured. The LH secretion was significantly increased at the doses greater than 0.5 Gy and FSH secretion was also significantly enhanced at the dose of 4.0 Gy. The cellular contents of both LH and FSH remained near the control levels. It is concluded that gonadotropin secretion can be stimulated by single doses of X-rays in the range of 0.5-8.0 Gy

Stimulation of corticosterone secretion in vitro by brief ACTH exposure

International Nuclear Information System (INIS)

Keith, L.D.; Tam, B.; Greer, M.A.

1986-01-01

The authors examined the relationship between ACTH concentration and exposure duration on stimulation of corticosterone (B) secretion in vitro using perifused enzymatically dispersed rat adrenocortical cells. A modular perifusion apparatus was used that permitted evaluation of 20-24 cell chambers per experimental session. In expt 1,20-1000 pg/ml concentrations of synthetic ACTH-(1-24) were presented to cells for 1 min. In expt 2, 100 pg ACTH-(1-24) was presented to adrenal cells in five dose-duration regimens ranging from 5 pg/min for 20 min to 100 pg/min for 1 min. Perifusal rate was 1 ml/min in all sessions. B was determined by radioimmunoassay. In expt 1 (constant-duration paradigm), 1-min presentation of ACTH-(1-24) produced log-linear dose-response effects across these concentrations. In expt 2 (constant-mass paradigm), identical masses administered in different dose-duration regimens had different steroidogenic efficacies: low-dose long-duration regimens provoked greater total release than high-dose short-duration regimens. Overall, every dose-duration regimen was associated with stimulation of B secretion. These results indicate that 1) very brief exposure to physiological concentrations of ACTH-(1-24) is a significant stimulus for corticosteroid secretion; 2) variations in the dose-duration regimen over the physiological range modifies both the maximum rate of secretion and the duration of secretion, but not the response latency; and 3) ACTH-(1-24) presentation mass is not the sole determinant of B secretion

LcrG secretion is not required for blocking of Yops secretion in Yersinia pestis

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Matson Jyl S

2008-02-01

Full Text Available Abstract Background LcrG, a negative regulator of the Yersinia type III secretion apparatus has been shown to be primarily a cytoplasmic protein, but is secreted at least in Y. pestis. LcrG secretion has not been functionally analyzed and the relevance of LcrG secretion on LcrG function is unknown. Results An LcrG-GAL4AD chimera, originally constructed for two-hybrid analyses to analyze LcrG protein interactions, appeared to be not secreted but the LcrG-GAL4AD chimera retained the ability to regulate Yops secretion. This result led to further investigation to determine the significance of LcrG secretion on LcrG function. Additional analyses including deletion and substitution mutations of amino acids 2–6 in the N-terminus of LcrG were constructed to analyze LcrG secretion and LcrG's ability to control secretion. Some changes to the N-terminus of LcrG were found to not affect LcrG's secretion or LcrG's secretion-controlling activity. However, substitution of poly-isoleucine in the N-terminus of LcrG did eliminate LcrG secretion but did not affect LcrG's secretion controlling activity. Conclusion These results indicate that secretion of LcrG, while observable and T3SS mediated, is not relevant for LcrG's ability to control secretion.

Tamper-proof secret image-sharing scheme for identifying cheated secret keys and shared images

Science.gov (United States)

Chen, Chien-Chang; Liu, Chong-An

2013-01-01

A (t,n) secret image-sharing scheme shares a secret image to n participants, and the t users recover the image. During the recovery procedure of a conventional secret image-sharing scheme, cheaters may use counterfeit secret keys or modified shared images to cheat other users' secret keys and shared images. A cheated secret key or shared image leads to an incorrect secret image. Unfortunately, the cheater cannot be identified. We present an exponent and modulus-based scheme to provide a tamper-proof secret image-sharing scheme for identifying cheaters on secret keys or shared images. The proposed scheme allows users to securely select their secret key. This assignment can be performed over networks. Modulus results of each shared image is calculated to recognize cheaters of a shared image. Experimental results indicate that the proposed scheme is excellent at identifying cheated secret keys and shared images.

Wrapped up in Covers: Preschoolers' Secrets and Secret Hiding Places

Science.gov (United States)

Corson, Kimberly; Colwell, Malinda J.; Bell, Nancy J.; Trejos-Castillo, Elizabeth

2014-01-01

In this qualitative study, interviews about children's secret hiding places were conducted with 3-5-year-olds (n?=?17) in a university sponsored preschool programme using art narratives. Since prior studies indicate that children understand the concept of a secret as early as five and that they associate secrets with hiding places, the purpose of…

Salmonella-secreted Virulence Factors

Energy Technology Data Exchange (ETDEWEB)

Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

2011-05-01

In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme

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Mustafa Ulutas

2010-01-01

Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.

Effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

International Nuclear Information System (INIS)

Hochberg, Z.; Kuten, A.; Hertz, P.; Tatcher, M.; Kedar, A.; Benderly, A.

1983-01-01

Cranial irradiation has been shown to impair growth hormone secretion in children. In this study a cell culture of dispersed rat anterior pituitary cells was exposed to single doses of radiation in the range of 100 to 1500 rad. Survival curves were obtained for the different anterior pituitary cell lines, and growth hormone secretion was measured in the tissue culture medium. Both survival and growth hormone secretion curves showed an initial shoulder in the range of 0 to 300 rad, followed by a decline between 300 to 750 rad. It is concluded that growth hormone secreting acidophilic pituicytes are sensitive to radiation at single doses greater than 300 rad

Cholecystokinin inhibits gastrin secretion independently of paracrine somatostatin secretion in the pig

DEFF Research Database (Denmark)

Schmidt, P T; Hansen, L; Hilsted, L

2004-01-01

BACKGROUND: Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. The aim of the study was to test directly whether cholecystokinin inhibition of antral gastrin secretion is mediated by somatostatin....... METHODS: The effects of CCK on gastrin and somatostatin secretion were studied in isolated vascularly perfused preparations of pig antrum before and after immunoneutralization brought about by infusion of large amounts of a high affinity monoclonal antibody against somatostatin. RESULTS: CCK infusion...... at 10(-9) M and 10(-8) M decreased gastrin output to 70.5% +/- 7.6% (n = 8) and 76.3% +/- 3.6% (n = 7) of basal output, respectively. CCK at 10(-10) M had no effect (n = 6). Somatostatin secretion was dose-dependently increased by CCK infusion and increased to 268 +/- 38.2% (n = 7) of basal secretion...

Dynamic quantum secret sharing

International Nuclear Information System (INIS)

Jia, Heng-Yue; Wen, Qiao-Yan; Gao, Fei; Qin, Su-Juan; Guo, Fen-Zhuo

2012-01-01

In this Letter we consider quantum secret sharing (QSS) between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications. -- Highlights: ► We consider quantum secret sharing between a sender and a dynamic agent group, called dynamic quantum secret sharing (DQSS). ► In the DQSS, the change of the agent group is allowable during the procedure of sharing classical and quantum information. ► Two DQSS schemes are proposed based on a special kind of entangled state, starlike cluster states. ► Without redistributing all the shares, the changed agent group can reconstruct the sender's secret by their cooperation. ► Compared with the previous quantum secret sharing scheme, our schemes are more flexible and suitable for practical applications.

Secreted factors as synaptic organizers.

Science.gov (United States)

Johnson-Venkatesh, Erin M; Umemori, Hisashi

2010-07-01

A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic differentiation. Many of these factors appear to function at both the neuromuscular junction and in the central nervous system, although the specific function of the molecules differs between the two. Here we review secreted molecules that organize the synaptic compartments and discuss how these molecules shape synaptic development, focusing on mammalian in vivo systems. Their critical role in shaping a functional neural circuit is underscored by their possible link to a wide range of neurological and psychiatric disorders both in animal models and by mutations identified in human patients. © The Authors (2010). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Dual control of pituitary thyroid stimulating hormone secretion by thyroxine and triiodothyronine in athyreotic patients

Science.gov (United States)

Hoermann, Rudolf; Midgley, John E. M.; Dietrich, Johannes W.; Larisch, Rolf

2017-01-01

Background: Patient responses to levothyroxine (LT4) monotherapy vary considerably. We sought to differentiate contributions of FT4 and FT3 in controlling pituitary thyroid stimulating hormone (TSH) secretion. Methods: We retrospectively assessed the relationships between TSH and thyroid hormones in 319 patients with thyroid carcinoma through 2914 visits on various LT4 doses during follow-up for 5.5 years (median, IQR 4.2, 6.9). We also associated patient complaints with the relationships. Results: Under varying dose requirements (median 1.84 µg/kg, IQR 1.62, 2.11), patients reached TSH targets below 0.4, 0.1 or 0.01 mIU/l at 73%, 54% and 27% of visits. While intercept, slope and fit of linearity of the relationships between lnTSH and FT4/FT3 varied between individuals, gender, age, LT4 dose and deiodinase activity influenced the relationships in the cohort (all p < 0.001). Deiodinase activity impaired by LT4 dose significantly affected the lnTSH–FT4 relationship. Dose increase and reduced conversion efficiency displaced FT3–TSH equilibria. In LT4-treated patients, FT4 and FT3 contributed on average 52% versus 38%, and by interaction 10% towards TSH suppression. Symptomatic presentations (11%) accompanied reduced FT3 concentrations (–0.23 pmol/l, p = 0.001) adjusted for gender, age and BMI, their relationships being shifted towards higher TSH values at comparable FT3/FT4 levels. Conclusions: Variation in deiodinase activity and resulting FT3 levels shape the TSH–FT4 relationship in LT4-treated athyreotic patients, suggesting cascade control of pituitary TSH production by the two hormones. Consequently, measurement of FT3 and calculation of conversion efficiency may identify patients with impaired biochemistry and a resulting lack of symptomatic control. PMID:28794850

Higher Energy Intake Variability as Predisposition to Obesity: Novel Approach Using Interquartile Range.

Science.gov (United States)

Forejt, Martin; Brázdová, Zuzana Derflerová; Novák, Jan; Zlámal, Filip; Forbelská, Marie; Bienert, Petr; Mořkovská, Petra; Zavřelová, Miroslava; Pohořalá, Aneta; Jurášková, Miluše; Salah, Nabil; Bienertová-Vašků, Julie

2017-12-01

It is known that total energy intake and its distribution during the day influences human anthropometric characteristics. However, possible association between variability in total energy intake and obesity has thus far remained unexamined. This study was designed to establish the influence of energy intake variability of each daily meal on the anthropometric characteristics of obesity. A total of 521 individuals of Czech Caucasian origin aged 16–73 years (390 women and 131 men) were included in the study, 7-day food records were completed by all study subjects and selected anthropometric characteristics were measured. The interquartile range (IQR) of energy intake was assessed individually for each meal of the day (as a marker of energy intake variability) and subsequently correlated with body mass index (BMI), body fat percentage (%BF), waist-hip ratio (WHR), and waist circumference (cW). Four distinct models were created using multiple logistic regression analysis and backward stepwise logistic regression. The most precise results, based on the area under the curve (AUC), were observed in case of the %BF model (AUC=0.895) and cW model (AUC=0.839). According to the %BF model, age (p<0.001) and IQR-lunch (p<0.05) seem to play an important prediction role for obesity. Likewise, according to the cW model, age (p<0.001), IQR-breakfast (p<0.05) and IQR-dinner (p <0.05) predispose patients to the development of obesity. The results of our study show that higher variability in the energy intake of key daily meals may increase the likelihood of obesity development. Based on the obtained results, it is necessary to emphasize the regularity in meals intake for maintaining proper body composition. Copyright© by the National Institute of Public Health, Prague 2017

Quantum strongly secure ramp secret sharing

DEFF Research Database (Denmark)

Zhang, Paul; Matsumoto, Rytaro Yamashita

2015-01-01

Quantum secret sharing is a scheme for encoding a quantum state (the secret) into multiple shares and distributing them among several participants. If a sufficient number of shares are put together, then the secret can be fully reconstructed. If an insufficient number of shares are put together...... however, no information about the secret can be revealed. In quantum ramp secret sharing, partial information about the secret is allowed to leak to a set of participants, called an unqualified set, that cannot fully reconstruct the secret. By allowing this, the size of a share can be drastically reduced....... This paper introduces a quantum analog of classical strong security in ramp secret sharing schemes. While the ramp secret sharing scheme still leaks partial information about the secret to unqualified sets of participants, the strong security condition ensures that qudits with critical information can...

Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages.

Directory of Open Access Journals (Sweden)

Maaike Kockx

Full Text Available Dynamins are fission proteins that mediate endocytic and exocytic membrane events and are pharmacological therapeutic targets. These studies investigate whether dynamin II regulates constitutive protein secretion and show for the first time that pharmacological inhibition of dynamin decreases secretion of apolipoprotein E (apoE and several other proteins constitutively secreted from primary human macrophages. Inhibitors that target recruitment of dynamin to membranes (MiTMABs or directly target the GTPase domain (Dyngo or Dynole series, dose- and time- dependently reduced the secretion of apoE. SiRNA oligo's targeting all isoforms of dynamin II confirmed the involvement of dynamin II in apoE secretion. Inhibition of secretion was not mediated via effects on mRNA or protein synthesis. 2D-gel electrophoresis showed that inhibition occurred after apoE was processed and glycosylated in the Golgi and live cell imaging showed that inhibited secretion was associated with reduced post-Golgi movement of apoE-GFP-containing vesicles. The effect was not restricted to macrophages, and was not mediated by the effects of the inhibitors on microtubules. Inhibition of dynamin also altered the constitutive secretion of other proteins, decreasing the secretion of fibronectin, matrix metalloproteinase 9, Chitinase-3-like protein 1 and lysozyme but unexpectedly increasing the secretion of the inflammatory mediator cyclophilin A. We conclude that pharmacological inhibitors of dynamin II modulate the constitutive secretion of macrophage apoE as a class effect, and that their capacity to modulate protein secretion may affect a range of biological processes.

Dynamic secrets in communication security

CERN Document Server

Xiao, Sheng; Towsley, Donald

2013-01-01

Dynamic secrets are constantly generated and updated from messages exchanged between two communication users. When dynamic secrets are used as a complement to existing secure communication systems, a stolen key or password can be quickly and automatically reverted to its secret status without disrupting communication. 'Dynamic Secrets in Communication Security' presents unique security properties and application studies for this technology. Password theft and key theft no longer pose serious security threats when parties frequently use dynamic secrets. This book also illustrates that a dynamic

Intra-islet glucagon secretion and action in the regulation of glucose homeostasis.

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Qinghua eWang

2013-01-01

Full Text Available Glucagon, a key hormone in the regulation of glucose homeostasis, acts as a counter-regulatory hormone to insulin by promoting hepatic glucose output. Under normal conditions, insulin and glucagon operate in concert to maintain the glucose level within a narrow physiological range. In diabetes, however, while insulin secretion or action is insufficient, the production and secretion of glucagon are excessive, contributing to the development of diabetic hyperglycemia. Within an islet, intra-islet insulin, in cooperation with intra-islet GABA, suppresses glucagon secretion via direct modulation of -cell intracellular signaling pathways involving Akt activation, GABA receptor phosphorylation and the receptor plasma membrane translocation, while intra-islet glucagon plays an important role in modulating β-cell function and insulin secretion. Defects in the insulin-glucagon fine-tuning machinery may result in β-cell glucose incompetence, leading to unsuppressed glucagon secretion and subsequent hyperglycemia, which often occur under extreme conditions of glucose influx or efflux. Therefore, deciphering the precise molecular mechanisms underlying glucagon secretion and action will facilitate our understanding of glucagon physiology, in particular, its role in regulating islet β-cell function, and hence the mechanisms behind body glucose homeostasis.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

Energy Technology Data Exchange (ETDEWEB)

Lee, Je Min, E-mail: jemin@knu.ac.kr [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of); Department of Horticultural Science, Kyungpook National University, Daegu (Korea, Republic of); Lee, Sang-Jik [Biotechnology Institute, Nongwoo Bio Co, Ltd, Yeoju (Korea, Republic of); Department of Plant Biology, Cornell University, Ithaca, NY (United States); Rose, Jocelyn K.C. [Department of Plant Biology, Cornell University, Ithaca, NY (United States); Yeam, Inhwa [Department of Horticulture and Breeding, Andong National University, Andong (Korea, Republic of); Kim, Byung-Dong [Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul (Korea, Republic of)

2014-04-18

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening.

Mining secreted proteins that function in pepper fruit development and ripening using a yeast secretion trap (YST)

International Nuclear Information System (INIS)

Lee, Je Min; Lee, Sang-Jik; Rose, Jocelyn K.C.; Yeam, Inhwa; Kim, Byung-Dong

2014-01-01

Highlights: • Yeast secretion trap (YST) is a valuable tool for mining secretome. • A total of 80 secreted proteins are newly identified via YST in pepper fruits. • The secreted proteins are differentially regulated during pepper development and ripening. • Transient GFP-fusion assay and in planta secretion trap can effectively validate the secretion of proteins. - Abstract: Plant cells secrete diverse sets of constitutively- and conditionally-expressed proteins under various environmental and developmental states. Secreted protein populations, or secretomes have multiple functions, including defense responses, signaling, metabolic processes, and developmental regulation. To identify genes encoding secreted proteins that function in fruit development and ripening, a yeast secretion trap (YST) screen was employed using pepper (Capsicum annuum) fruit cDNAs. The YST screen revealed 80 pepper fruit-related genes (CaPFRs) encoding secreted proteins including cell wall proteins, several of which have not been previously described. Transient GFP-fusion assay and an in planta secretion trap were used to validate the secretion of proteins encoded by selected YST clones. In addition, RNA gel blot analyses provided further insights into their expression and regulation during fruit development and ripening. Integrating our data, we conclude that the YST provides a valuable functional genomics tool for the identification of substantial numbers of novel secreted plant proteins that are associated with biological processes, including fruit development and ripening

Immunoglobins in mammary secretions

DEFF Research Database (Denmark)

Hurley, W L; Theil, Peter Kappel

2013-01-01

Immunoglobulins secreted in colostrum and milk by the lactating mammal are major factors providing immune protection to the newborn. Immunoglobulins in mammary secretions represent the cumulative immune response of the lactating animal to exposure to antigenic stimulation that occurs through...... the immunoglobulins found in mammary secretions in the context of their diversity of structure, origin, mechanisms of transfer, and function....

Matroids and quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Sarvepalli, Pradeep; Raussendorf, Robert

2010-01-01

A secret-sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret-sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret-sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum-secret-sharing schemes. In addition to providing a new perspective on quantum-secret-sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum-secret-sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum-secret-sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure-state quantum-secret-sharing scheme with information rate 1.

Extracellular secretion of recombinant proteins

Science.gov (United States)

Linger, Jeffrey G.; Darzins, Aldis

2014-07-22

Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

Validity of using tri-axial accelerometers to measure human movement - Part II: Step counts at a wide range of gait velocities.

Science.gov (United States)

Fortune, Emma; Lugade, Vipul; Morrow, Melissa; Kaufman, Kenton

2014-06-01

A subject-specific step counting method with a high accuracy level at all walking speeds is needed to assess the functional level of impaired patients. The study aim was to validate step counts and cadence calculations from acceleration data by comparison to video data during dynamic activity. Custom-built activity monitors, each containing one tri-axial accelerometer, were placed on the ankles, thigh, and waist of 11 healthy adults. ICC values were greater than 0.98 for video inter-rater reliability of all step counts. The activity monitoring system (AMS) algorithm demonstrated a median (interquartile range; IQR) agreement of 92% (8%) with visual observations during walking/jogging trials at gait velocities ranging from 0.1 to 4.8m/s, while FitBits (ankle and waist), and a Nike Fuelband (wrist) demonstrated agreements of 92% (36%), 93% (22%), and 33% (35%), respectively. The algorithm results demonstrated high median (IQR) step detection sensitivity (95% (2%)), positive predictive value (PPV) (99% (1%)), and agreement (97% (3%)) during a laboratory-based simulated free-living protocol. The algorithm also showed high median (IQR) sensitivity, PPV, and agreement identifying walking steps (91% (5%), 98% (4%), and 96% (5%)), jogging steps (97% (6%), 100% (1%), and 95% (6%)), and less than 3% mean error in cadence calculations. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Semiquantum secret sharing using entangled states

International Nuclear Information System (INIS)

Li Qin; Chan, W. H.; Long Dongyang

2010-01-01

Secret sharing is a procedure for sharing a secret among a number of participants such that only the qualified subsets of participants have the ability to reconstruct the secret. Even in the presence of eavesdropping, secret sharing can be achieved when all the members are quantum. So what happens if not all the members are quantum? In this paper, we propose two semiquantum secret sharing protocols by using maximally entangled Greenberger-Horne-Zeilinger-type states in which quantum Alice shares a secret with two classical parties, Bob and Charlie, in a way that both parties are sufficient to obtain the secret, but one of them cannot. The presented protocols are also shown to be secure against eavesdropping.

Probabilistic Infinite Secret Sharing

OpenAIRE

Csirmaz, László

2013-01-01

The study of probabilistic secret sharing schemes using arbitrary probability spaces and possibly infinite number of participants lets us investigate abstract properties of such schemes. It highlights important properties, explains why certain definitions work better than others, connects this topic to other branches of mathematics, and might yield new design paradigms. A probabilistic secret sharing scheme is a joint probability distribution of the shares and the secret together with a colle...

RSA-Based Secret Handshakes

OpenAIRE

Vergnaud , Damien

2006-01-01

A secret handshake mechanism allows two entities, members of a same group, to authenticate each other secretly. This primitive was introduced recently by Balfanz, Durfee, Shankar, Smetters, Staddon and Wong and, so far, all the schemes proposed are based on discrete log systems. This paper proposes three new secret handshake protocols secure against active impersonator and detector adversaries. Inspired by two RSA-based key agreement protocols introduced by Okamoto and Tanaka in 1989 and Gira...

Efficient multiparty quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Xiao Li; Deng Fuguo; Long Guilu; Pan Jianwei

2004-01-01

In this work, we generalize the quantum-secret-sharing scheme of Hillery, Buzek, and Berthiaume [Phys. Rev. A 59, 1829 (1999)] into arbitrary multiparties. Explicit expressions for the shared secret bit is given. It is shown that in the Hillery-Buzek-Berthiaume quantum-secret-sharing scheme the secret information is shared in the parity of binary strings formed by the measured outcomes of the participants. In addition, we have increased the efficiency of the quantum-secret-sharing scheme by generalizing two techniques from quantum key distribution. The favored-measuring-basis quantum-secret-sharing scheme is developed from the Lo-Chau-Ardehali technique [H. K. Lo, H. F. Chau, and M. Ardehali, e-print quant-ph/0011056] where all the participants choose their measuring-basis asymmetrically, and the measuring-basis-encrypted quantum-secret-sharing scheme is developed from the Hwang-Koh-Han technique [W. Y. Hwang, I. G. Koh, and Y. D. Han, Phys. Lett. A 244, 489 (1998)] where all participants choose their measuring basis according to a control key. Both schemes are asymptotically 100% in efficiency, hence nearly all the Greenberger-Horne-Zeilinger states in a quantum-secret-sharing process are used to generate shared secret information

Effect of inhibition of microsomal Ca(2+)-ATPase on cytoplasmic calcium and enzyme secretion in pancreatic acini.

Science.gov (United States)

Metz, D C; Pradhan, T K; Mrozinski, J E; Jensen, R T; Turner, R J; Patto, R J; Gardner, J D

1994-01-13

We used thapsigargin (TG), 2,5-di-tert-butyl-1,4-benzohydroquinone (BHQ) and cyclopiazonic acid (CPA), each of which inhibits microsomal Ca(2+)-ATPase, to evaluate the effects of this inhibition on cytoplasmic free calcium ([Ca2+]i) and secretagogue-stimulated enzyme secretion in rat pancreatic acini. Using single-cell microspectrofluorimetry of fura-2-loaded acini we found that all three agents caused a sustained increase in [Ca2+]i by mobilizing calcium from inositol-(1,4,5)-trisphosphate-sensitive intracellular calcium stores and by promoting influx of extracellular calcium. Concentrations of all three agents that increased [Ca2+]i potentiated the stimulation of enzyme secretion caused by secretagogues that activate adenylate cyclase but inhibited the stimulation of enzyme secretion caused by secretagogues that activate phospholipase C. With BHQ, potentiation of adenylate cyclase-mediated enzyme secretion occurred immediately whereas inhibition of phospholipase C-mediated enzyme secretion occurred only after several min of incubation. In addition, the effects of BHQ and CPA on both [Ca2+]i and secretagogue-stimulated enzyme secretion were reversed completely by washing whereas the actions of TG could not be reversed by washing. Concentrations of BHQ in excess of those that caused maximal changes in [Ca2+]i inhibited all modes of stimulated enzyme secretion by a mechanism that was apparently unrelated to changes in [Ca2+]i. Finally, in contrast to the findings with TG and BHQ, CPA inhibited bombesin-stimulated enzyme secretion over a range of concentrations that was at least 10-fold lower than the range of concentrations over which CPA potentiated VIP-stimulated enzyme secretion.

Secretion management in the mechanically ventilated patient.

Science.gov (United States)

Branson, Richard D

2007-10-01

Secretion management in the mechanically ventilated patient includes routine methods for maintaining mucociliary function, as well as techniques for secretion removal. Humidification, mobilization of the patient, and airway suctioning are all routine procedures for managing secretions in the ventilated patient. Early ambulation of the post-surgical patient and routine turning of the ventilated patient are common secretion-management techniques that have little supporting evidence of efficacy. Humidification is a standard of care and a requisite for secretion management. Both active and passive humidification can be used. The humidifier selected and the level of humidification required depend on the patient's condition and the expected duration of intubation. In patients with thick, copious secretions, heated humidification is superior to a heat and moisture exchanger. Airway suctioning is the most important secretion removal technique. Open-circuit and closed-circuit suctioning have similar efficacy. Instilling saline prior to suctioning, to thin the secretions or stimulate a cough, is not supported by the literature. Adequate humidification and as-needed suctioning are the foundation of secretion management in the mechanically ventilated patient. Intermittent therapy for secretion removal includes techniques either to simulate a cough, to mechanically loosen secretions, or both. Patient positioning for secretion drainage is also widely used. Percussion and postural drainage have been widely employed for mechanically ventilated patients but have not been shown to reduce ventilator-associated pneumonia or atelectasis. Manual hyperinflation and insufflation-exsufflation, which attempt to improve secretion removal by simulating a cough, have been described in mechanically ventilated patients, but neither has been studied sufficiently to support routine use. Continuous lateral rotation with a specialized bed reduces atelectasis in some patients, but has not been shown

Incretin secretion: direct mechanisms

DEFF Research Database (Denmark)

Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich

2014-01-01

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...

Detection of B-lymphocytes secreting antibodies to Dermatophagoides antigens

DEFF Research Database (Denmark)

Sparholt, S H; Barington, T; Schou, C

1991-01-01

Alutard, showed that 1 week after injection, circulating allergen-specific antibody-secreting cells (AbSC) were detected with this assay. The ranges were between 1 and 13 IgM-, 2 and 20 IgG- and 20 and 55 IgA allergen-specific AbSC per 10(6) MNC. It is expected that this assay will help to understand more...

Shared Secrets versus Secrets Kept Private Are Linked to Better Adolescent Adjustment

Science.gov (United States)

Frijns, Tom; Finkenauer, Catrin; Keijsers, Loes

2013-01-01

It is a household notion that secrecy is bad while sharing is good. But what about shared secrets? The present research adopts a functional analysis of sharing secrets, arguing that it should negate harmful consequences generally associated with secrecy and serves important interpersonal functions in adolescence. A survey study among 790 Dutch…

Thyrotropin secreting pituitary adenoma accompanying a silent somatotropinoma.

Science.gov (United States)

Berker, Dilek; Isik, Serhat; Aydin, Yusuf; Tutuncu, Yasemin; Akdemir, Gokhan; Ozcan, Hatice Nursun; Guler, Serdar

2011-01-01

Thyroid stimulating hormone (TSH) secreting pituitary adenomas are rare tumors manifested as hyperthyroidism with goiter in the presence of elevated TSH. We present a case with pituitary adenoma secreting both TSH and growth hormone (GH) with the prominent clinical findings of hyperthyroidism but without clinical findings of acromegaly. Pituitary magnetic resonance imaging revealed a macroadenoma. Transsphenoidal surgery was performed twice. The immunohistochemical staining showed that tumor cells were strongly reactive to GH and relatively mildly reactive to TSH. Control pituitary imaging revealed a residual macroadenoma, and long acting octreotide treatment was administered. After two years of the treatment, tumor size remained the same while thyroid function tests and insulin-like growth factor 1 (IGF-I) values returned to normal ranges. In conclusion, we always recommend hormonal examinations for all patients who have pituitary adenoma without signs and symptoms of acromegaly.

Correlation of secretion of retinol and protein by the lacrimal gland

International Nuclear Information System (INIS)

Ubels, J.L.; Rismondo, V.

1986-01-01

Retinol, which is present in tears, is secreted by the lacrimal gland. Retinol secretion is stimulated by cholinergic drugs and vasoactive intestinal peptide with characteristics very similar to the exocytotic secretion of protein by the lacrimal gland, suggesting that retinol and protein are secreted by similar mechanisms. The authors investigated this by cannulating the lacrimal gland ducts of rabbits and collecting lacrimal gland fluid (LGF) under conditions of maximal flow stimulated by IV injection of pilocarpine (400 μg/kg) every 20 min for 4.5 hr. Over this period LGF protein concentration decreased 36.4% from 22.8 +/- 1.94 mg/ml to 8.29 1.86 mg/ml while retinol decreased 37% from 55.1 +/- 16.2 ng/ml to 20.4 +/- 6.5 ng/ml. The retinol/protein ratio remained constant at 2.88 ng/mg. This demonstrates a strong correlation between retinol and protein secretion, suggesting that retinol may be protein bound. To investigate binding of retinol to LGF protein, LGF was incubated with 3 H-retinol. The bound and unbound retinol were separated on a Lipidex 1000 column. Retinol binding was linear over a range of 1.25-200 nM 3 H-retinol. Binding was not inhibited by PCMBS or addition of a 100-fold excess of unlabeled retinol and was not increased by prior extraction of endogenous retinol from the LGF. This indicates that the binding of retinol to LGF protein is non-specific. Retinol therefore appears to be secreted by the lacrimal gland cells in non-specific association with protein

On alternative approach for verifiable secret sharing

OpenAIRE

Kulesza, Kamil; Kotulski, Zbigniew; Pieprzyk, Joseph

2002-01-01

Secret sharing allows split/distributed control over the secret (e.g. master key). Verifiable secret sharing (VSS) is the secret sharing extended by verification capacity. Usually verification comes at the price. We propose "free lunch", the approach that allows to overcome this inconvenience.

The relationship between thyroxine secretion rate and egg production in chicken

International Nuclear Information System (INIS)

Sri Asminah; Soewarsono, M.; Djojosoebagio, S.

1976-01-01

An experiment was carried out in 24 female White Leghorn Chickens by using 131 I as tracer. The chickens were initially and intraperitoneally injected with 10μCi of 131 I and then counted by means of a Gamma Well Type Scintillation Counter every 48 hours. A dose of 0,3 μg of thyroxine per 100 gr body weight was given as the first administration. After every two administrations of similar dose, the dose of the thyroxine was increased by 0,1 μg/100g body weight until the thyroxine secretion rate was reached. The injections were given in the neck region subcutaneously. The thyroxine secretion rate was found to be within the range from 0,5μg to 0,8μg per 100 g body weight. It also showed that the higher the thyroxine secretion rate, the higher the egg production became. This phenomenon occured both with the 7 and 9 months old chickens. However there was neither ralationship between the thyroxine secretion rate and the weight of eggs produced nor with the body weight of the chickens themselves. (author)

Trade Secrets in Life Science and Pharmaceutical Companies

Science.gov (United States)

Nealey, Tara; Daignault, Ronald M.; Cai, Yu

2015-01-01

Trade secret protection arises under state common law and state statutes. In general, a trade secret is information that is not generally known to the public and is maintained as a secret, and it provides a competitive advantage or economic benefit to the trade secret holder. Trade secrets can be worth tens or hundreds of millions of dollars, and damage awards in trade secret litigation have been high; often, there is a lot at stake. Obtaining a trade secret through “improper means” is misappropriation. If the alleged trade secret, however, was developed independently, known publicly, or not maintained as a secret, then those defenses may successfully overcome a claim for trade secret misappropriation. With today’s interconnectedness in the biotechnology and pharmaceutical fields, more collaborations, joint ventures, and outsourcing arrangements among firms, and increased mobility of employees’ careers, life science companies need to not only understand how to protect their trade secrets, but also know how to defend against a claim for trade secret theft. PMID:25414378

Trade secrets in life science and pharmaceutical companies.

Science.gov (United States)

Nealey, Tara; Daignault, Ronald M; Cai, Yu

2014-11-20

Trade secret protection arises under state common law and state statutes. In general, a trade secret is information that is not generally known to the public and is maintained as a secret, and it provides a competitive advantage or economic benefit to the trade secret holder. Trade secrets can be worth tens or hundreds of millions of dollars, and damage awards in trade secret litigation have been high; often, there is a lot at stake. Obtaining a trade secret through "improper means" is misappropriation. If the alleged trade secret, however, was developed independently, known publicly, or not maintained as a secret, then those defenses may successfully overcome a claim for trade secret misappropriation. With today's interconnectedness in the biotechnology and pharmaceutical fields, more collaborations, joint ventures, and outsourcing arrangements among firms, and increased mobility of employees' careers, life science companies need to not only understand how to protect their trade secrets, but also know how to defend against a claim for trade secret theft. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

The effect of centrifugation speed and time on pre-analytical platelet activation

DEFF Research Database (Denmark)

Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

2016-01-01

BACKGROUND: The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation....... METHODS: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean...... of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p...

Two-party secret key distribution via a modified quantum secret sharing protocol.

Science.gov (United States)

Grice, W P; Evans, P G; Lawrie, B; Legré, M; Lougovski, P; Ray, W; Williams, B P; Qi, B; Smith, A M

2015-03-23

We present and demonstrate a novel protocol for distributing secret keys between two and only two parties based on N-party single-qubit Quantum Secret Sharing (QSS). We demonstrate our new protocol with N = 3 parties using phase-encoded photons. We show that any two out of N parties can build a secret key based on partial information from each other and with collaboration from the remaining N - 2 parties. Our implementation allows for an accessible transition between N-party QSS and arbitrary two party QKD without modification of hardware. In addition, our approach significantly reduces the number of resources such as single photon detectors, lasers and dark fiber connections needed to implement QKD.

5 CFR 1312.27 - Top secret control.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Top secret control. 1312.27 Section 1312... Classified Information § 1312.27 Top secret control. The EOP Security Officer serves as the Top Secret... Top Secret material. The ATSCOs will be responsible for the accountability and custodianship of Top...

Effect of adrenal hormones on thyroid secretion and thyroid hormones on adrenal secretion in the sheep.

Science.gov (United States)

Falconer, I R; Jacks, F

1975-01-01

1. Previous work has shown that after stressful stimuli, sheep initially secrete increased amounts of thyroid hormone, at a time when adrenal secretion is also elevated. 2. This study was designed to evaluate (a) any short-term activation or inhibition of thyroid secretion by exogenous cortisol or ACTH administered in quantities comparable to those secreted after stress in sheep and (b) any short-term effect that exogenous thyroxine or triiodothyronine may have on the concentration of plasma cortisol in the sheep. 3. Thyroid activity was measured by determination of plasma protein bound 125I (PB125I) and total 125I in thyroid vein and mixed venous (jugular) blood. Plasma cortisol and thyroxine concentrations were measured by a competitive protein-binding assay at intervals for up to 5 hr after commencement of the experiment. 4. No evidence of an activation of thyroid secretion was found during cortisol or ACTH infusion, as monitored by thyroid vein PB125I. Similarly there was no evidence of any inhibition of thyroid function, as measured by continued secretion of thyroid hormones into thyroid vein blood. 5. No effect on plasma cortisol concentration due to thyroid hormone treatment was observed. 6. It was concluded that (a) elevated circulating corticosteroids in physiological concentrations have no short-term effects on thyroid activity in the sheep and (b) the short-term alterations in thyroid and adrenal cortical secretion observed during stress in the sheep could not be attributed to direct interaction of elevated thyroid hormone concentrations with adrenal cortical secretion. PMID:170400

Secretion Trap Tagging of Secreted and Membrane-Spanning Proteins Using Arabidopsis Gene Traps

Science.gov (United States)

Andrew T. Groover; Joseph R. Fontana; Juana M. Arroyo; Cristina Yordan; W. Richard McCombie; Robert A. Martienssen

2003-01-01

Secreted and membrane-spanning proteins play fundamental roles in plant development but pose challenges for genetic identification and characterization. We describe a "secretion trap" screen for gene trap insertions in genes encoding proteins routed through the secretory pathway. The gene trap transposon encodes a ß-glucuronidase reporter enzyme...

A lower isoelectric point increases signal sequence-mediated secretion of recombinant proteins through a bacterial ABC transporter.

Science.gov (United States)

Byun, Hyunjong; Park, Jiyeon; Kim, Sun Chang; Ahn, Jung Hoon

2017-12-01

Efficient protein production for industrial and academic purposes often involves engineering microorganisms to produce and secrete target proteins into the culture. Pseudomonas fluorescens has a TliDEF ATP-binding cassette transporter, a type I secretion system, which recognizes C-terminal LARD3 signal sequence of thermostable lipase TliA. Many proteins are secreted by TliDEF in vivo when recombined with LARD3, but there are still others that cannot be secreted by TliDEF even when LARD3 is attached. However, the factors that determine whether or not a recombinant protein can be secreted through TliDEF are still unknown. Here, we recombined LARD3 with several proteins and examined their secretion through TliDEF. We found that the proteins secreted via LARD3 are highly negatively charged with highly-acidic isoelectric points (pI) lower than 5.5. Attaching oligo-aspartate to lower the pI of negatively-charged recombinant proteins improved their secretion, and attaching oligo-arginine to negatively-charged proteins blocked their secretion by LARD3. In addition, negatively supercharged green fluorescent protein (GFP) showed improved secretion, whereas positively supercharged GFP did not secrete. These results disclosed that proteins' acidic pI and net negative charge are major factors that determine their secretion through TliDEF. Homology modeling for TliDEF revealed that TliD dimer forms evolutionarily-conserved positively-charged clusters in its pore and substrate entrance site, which also partially explains the pI dependence of the TliDEF-dependent secretions. In conclusion, lowering the isoelectric point improved LARD3-mediated protein secretion, both widening the range of protein targets for efficient production via secretion and signifying an important aspect of ABC transporter-mediated secretions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

22 CFR 1421.15 - Secret ballot.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Secret ballot. 1421.15 Section 1421.15 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY; GENERAL COUNSEL OF THE... THIS SUBCHAPTER § 1421.15 Secret ballot. Secret ballot means the expression by ballot, voting machine...

Alternative protein secretion: The Mam1 ABC transporter supports secretion of M-factor linked GFP in fission yeast

International Nuclear Information System (INIS)

Kjaerulff, Soren; Mueller, Sven; Jensen, Martin Roland

2005-01-01

To examine whether the fission yeast Mam1 ABC transporter can be used for secretion of heterologous proteins, thereby bypassing the classical secretion pathway, we have analyzed chimeric forms of the M-factor precursor. It was demonstrated that GFP can be exported when fused to both the amino-terminal prosequence from mfm1 and a CaaX motif. This secretion was dependent on the Mam1 transporter and not the classical secretion pathway. The secretion efficiency of GFP, however, was relatively low and most of the reporter protein was trapped in the vacuolar membranes. Our findings suggest that the Mam1 ABC protein is a promiscuous peptide transporter that can accommodate globular proteins of a relatively large size. Furthermore, our results help in defining the sequences required for processing and secretion of natural M-factor

29 CFR 401.11 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Secret ballot. 401.11 Section 401.11 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS MEANING OF TERMS USED IN THIS SUBCHAPTER § 401.11 Secret ballot. Secret ballot means the expression by...

29 CFR 1202.4 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Secret ballot. 1202.4 Section 1202.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.4 Secret ballot. In conducting such investigation, the Board is authorized to take a secret ballot of the employees involved, or...

The Secret of Future Victories

Science.gov (United States)

1992-02-01

Copy S of 320 copies AD--A25 0 718 IDA PAPER P-265 3 THE SECRET OF FUTURE VICTORIES Paul F. Gormnan General, USA (Retired) DTIC 05M February 1992 NAY...TYPE AND DATES COVERED IFebruary 1992 Final--June 1991-January 1992 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS The Secret of Future Victories C -MDA...8 2N0-102 IDA PAPER P-2653 THE SECRET OF FUTURE VICTORIES Paul F. Gorman General. LUSA (Retired) February 1992 Approved for public release

Current Therapies That Modify Glucagon Secretion

DEFF Research Database (Denmark)

Grøndahl, Magnus F.; Keating, Damien J.; Vilsbøll, Tina

2017-01-01

and provide insights into how antidiabetic drugs influence glucagon secretion as well as a perspective on the future of glucagon-targeting drugs. Recent Findings: Several older as well as recent investigations have evaluated the effect of antidiabetic agents on glucagon secretion to understand how glucagon...... may be involved in the drugs’ efficacy and safety profiles. Based on these findings, modulation of glucagon secretion seems to play a hitherto underestimated role in the efficacy and safety of several glucose-lowering drugs. Summary: Numerous drugs currently available to diabetologists are capable...... of altering glucagon secretion: metformin, sulfonylurea compounds, insulin, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors and amylin mimetics. Their diverse effects on glucagon secretion are of importance for their individual efficacy...

Characterization of a secreted Chlamydia protease

DEFF Research Database (Denmark)

Shaw, A.C.; Vandahl, B.B.; Larsen, M.R.

2002-01-01

Chlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in order...... to promote infection. Effector proteins cannot be identified by motif or similarity searches. As a new strategy for identification of secreted proteins we have compared 2D-PAGE profiles of [35S]-labelled Chlamydia proteins from whole lysates of infected cells to 2D-PAGE profiles of proteins from purified...... Chlamydia. Several secretion candidates from Chlamydia trachomatis D and Chlamydia pneumoniae were detected by this method. Two protein spots were identified among the candidates. These represent fragments of the 'chlamydial protease- or proteasome-like activity factor' (CPAF) and were clearly present in 2D...

EFFECTS OF SECRETABLE PLACENTAL FACTORS UPON SECRETION OF CYTOKINES BY THP-1 MONOCYTE-LIKE CELLS

Directory of Open Access Journals (Sweden)

Ya. S. Onokhina

2013-01-01

Full Text Available Abstract. Мonocytes in feto-placental circulation are exposed to factors secreted by placental tissue. These factors influence monocyte functions in pregnancy. In present study, an in vitro model (monocyte-like THP-1 cells was used for assessing effects of soluble placental factors obtained from women with physiological pregnancies, or preeclampsia cases. The following effects of placental factors were revealed: increased secretion of VEGF by THP-1 cells along with decreased secretion of IL-6, IL-8 and MCP-1 under the influence of placental factors from the I. trimester of pregnancy in comparison with III. trimester. Secretion of IL-6 and MCP-1 by THP-1 cells was increased, and secretion of soluble TNFRII was decreased upon co-cultivation with soluble placental factors from the women with preeclampsia, as compared with placental products from physiological pregnancies.The work is supported by grants ГК № 02.740.11.0711 from Ministry of Education and Science, and НШ-3594.2010.7 grant from the President of Russian Federation.

5 CFR 2421.15 - Secret ballot.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Secret ballot. 2421.15 Section 2421.15... FEDERAL LABOR RELATIONS AUTHORITY MEANING OF TERMS AS USED IN THIS SUBCHAPTER § 2421.15 Secret ballot. Secret ballot means the expression by ballot, voting machine or otherwise, but in no event by proxy, of a...

29 CFR 452.97 - Secret ballot.

Science.gov (United States)

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Secret ballot. 452.97 Section 452.97 Labor Regulations... OF 1959 Election Procedures; Rights of Members § 452.97 Secret ballot. (a) A prime requisite of elections regulated by title IV is that they be held by secret ballot among the members or in appropriate...

Secretive eating among youth with overweight or obesity.

Science.gov (United States)

Kass, Andrea E; Wilfley, Denise E; Eddy, Kamryn T; Boutelle, Kerri N; Zucker, Nancy; Peterson, Carol B; Le Grange, Daniel; Celio-Doyle, Angela; Goldschmidt, Andrea B

2017-07-01

Secretive eating, characterized by eating privately to conceal being seen, may reflect eating- and/or body-related shame, be associated with depression, and correlate with binge eating, which predicts weight gain and eating disorder onset. Increasing understanding of secretive eating in youth may improve weight status and reduce eating disorder risk. This study evaluated the prevalence and correlates of secretive eating in youth with overweight or obesity. Youth (N = 577) presented to five research/clinical institutions. Using a cross-sectional design, secretive eating was evaluated in relation to eating-related and general psychopathology via linear and logistic regression analyses. Secretive eating was endorsed by 111 youth, who were, on average, older than youth who denied secretive eating (mean age = 12.07 ± 2.83 versus 10.97 ± 2.31). Controlling for study site and age, youth who endorsed secretive eating had higher eating-related psychopathology and were more likely to endorse loss of control eating and purging than their counterparts who did not endorse secretive eating. Groups did not differ in excessive exercise or behavioral problems. Dietary restraint and purging were elevated among adolescents (≥13y) but not children (<13y) who endorsed secretive eating; depression was elevated among children, but not adolescents, who endorsed secretive eating. Secretive eating may portend heightened risk for eating disorders, and correlates of secretive eating may differ across pediatric development. Screening for secretive eating may inform identification of problematic eating behaviors, and understanding factors motivating secretive eating may improve intervention tailoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

Triacylglycerol secretion in rats: validation of a tracer method employing radioactive glycerol

International Nuclear Information System (INIS)

Bird, M.; Williams, M.A.; Baker, N.

1984-01-01

A two-compartment model was developed to analyze the temporal changes in plasma triacylglycerol (TG)-specific radioactivity after injection of [2- 3 H]glycerol into rats. The analysis, which yielded fractional rate constants of TG secretion, was tested in rats fed diets either adequate or deficient in essential fatty acids (EFA) and containing either glucose, fructose or sucrose as the dietary carbohydrate. The method of analysis appeared valid, first, because of a close agreement between experimental and computer-fitted TG-specific radioactivity curves, and second, because the fractional rate constants obtained were quite similar to fractional rate constants determined previously by the Triton WR-1339 technique in rats maintained on identical diets. The results show that EFA deficiency increased the fractional rate constant of TG secretion 1.7-, 1.8- and 3.3-fold and the rate of TG secretion 1.8-, 1.6- and 1.4-fold when the dietary carbohydrate was glucose, sucrose and fructose, respectively, in comparison with control rats fed diets supplying these same carbohydrates but adequate in EFA. In the latter groups, the rates of plasma TG secretion were in the range of 0.14-0.17 mg/min per 100 g body weight, and the rate of secretion in the fructose-fed rats was only 20% higher than in the glucose-fed rats

Extracellular secretion of a recombinant therapeutic peptide by Bacillus halodurans utilizing a modified flagellin type III secretion system

CSIR Research Space (South Africa)

Berger, E

2011-08-01

Full Text Available further 3.5-fold increase in the secretion of recombinant peptide fusions. Conclusions: The type III flagellar secretion system of B. halodurans has been shown to successfully secrete a therapeutic peptide as a heterologous flagellin fusion. Improvements...

Pituitary-hormone secretion by thyrotropinomas

NARCIS (Netherlands)

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M.; Biermasz, Nienke R.; Smit, Jan W.; Frolich, Marijke; Keenan, Daniel M.; Veldhuis, Johannes D.; Romijn, Johannes A.

2009-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading

In situ monitoring of PTHLH secretion in neuroblastoma cells cultured onto nanoporous membranes.

Science.gov (United States)

de la Escosura-Muñiz, Alfredo; Espinoza-Castañeda, Marisol; Chamorro-García, Alejandro; Rodríguez-Hernández, Carlos J; de Torres, Carmen; Merkoçi, Arben

2018-06-01

In this work, we propose for the first time the use of anodic aluminum oxide (AAO) nanoporous membranes for in situ monitoring of parathyroid hormone-like hormone (PTHLH) secretion in cultured human cells. The biosensing system is based on the nanochannels blockage upon immunocomplex formation, which is electrically monitored through the voltammetric oxidation of Prussian blue nanoparticles (PBNPs). Models evaluated include a neuroblastoma cell line (SK-N-AS) and immortalized keratinocytes (HaCaT) as a control of high PTHLH production. The effect of total number of seeded cells and incubation time on the secreted PTHLH levels is assessed, finding that secreted PTHLH levels range from approximately 60 to 400 ng/mL. Moreover, our methodology is also applied to analyse PTHLH production following PTHLH gene knockdown upon transient cell transfection with a specific silencing RNA (siRNA). Given that inhibition of PTHLH secretion reduces cell proliferation, survival and invasiveness in a number of tumors, our system provides a powerful tool for the preclinical evaluation of therapies that regulate PTHLH production. This nanoporous membrane - based sensing technology might be useful to monitor the active secretion of other proteins as well, thus contributing to characterize their regulation and function. Copyright © 2018 Elsevier B.V. All rights reserved.

Normal and abnormal secretion by haemopoietic cells

Science.gov (United States)

STINCHCOMBE, JANE C; GRIFFITHS, GILLIAN M

2001-01-01

The secretory lysosomes found in haemopoietic cells provide a very efficient mechanism for delivering the effector proteins of many immune cells in response to antigen recognition. Although secretion shows some similarities to the secretion of specialized granules in other secretory cell types, some aspects of secretory lysosome release appear to be unique to melanocytes and cells of the haemopoietic lineage. Mast cells and platelets have provided excellent models for studying secretion, but recent advances in characterizing the immunological synapse allow a very fine dissection of the secretory process in T lymphocytes. These studies show that secretory lysosomes are secreted from the centre of the talin ring at the synapse. Proper secretion requires a series of Rab and cytoskeletal elements which play critical roles in the specialized secretion of lysosomes in haemopoietic cells. PMID:11380687

Some Economics of Trade Secret Law

OpenAIRE

David D. Friedman; William M. Landes; Richard A. Posner

1991-01-01

Despite the practical importance of trade secrets to the business community, the law of trade secrets is a neglected orphan in economic analysis. This paper sketches an approach to the economics of trade secret law that connects it more closely both to other areas of intellectual property and to broader issues in the positive economic theory of the common law.

Physiology of bile secretion.

Science.gov (United States)

Esteller, Alejandro

2008-10-07

The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

Variations in gastric acid secretion during periods of fasting between two species of shark.

Science.gov (United States)

Papastamatiou, Yannis P; Lowe, Christopher G

2005-06-01

Vertebrates differ in their regulation of gastric acid secretion during periods of fasting, yet it is unknown why these differences occur. Elasmobranch fishes are the earliest known vertebrates to develop an acid secreting stomach and as such may make a good comparative model for determining the causative factors behind these differences. We measured gastric pH and temperature continuously during periods of fasting in captive free-swimming nurse sharks (Ginglymostoma cirratum) using autonomous pH/temperature data-loggers. All nurse sharks secreted strong gastric acids (minimum pH 0.4) after feeding; however, for most of the sharks, pH increased to 8.2-8.7, 2-3 days after feeding. Half of the sharks also exhibited periodic oscillations in pH when the stomach was empty that ranged from 1.1 to 8.7 (acid secretion ceased for 11.3 +/- 4.3 h day(-1)). This is in contrast to the gastric pH changes observed from leopard sharks (Triakis semifasciata) in a previous study, where the stomach remains acidic during fasting. The leopard shark is a relatively active, more frequently feeding predator, and continuous acid secretion may increase digestive efficiency. In contrast, the nurse shark is less active and is thought to feed less frequently. Periodic cessation of acid secretion may be an energy conserving mechanism used by animals that feed infrequently and experience extended periods of fasting.

Analysis of chemical profiles of insect adhesion secretions by gas chromatography–mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Reitz, Manuela [Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Gerhardt, Heike [Institute of Pharmaceutical Sciences, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Schmitt, Christian; Betz, Oliver [Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen (Germany); Albert, Klaus, E-mail: klaus.albert@uni-tuebingen.de [Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Lämmerhofer, Michael, E-mail: michael.laemmerhofer@uni-tuebingen.de [Institute of Pharmaceutical Sciences, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany)

2015-01-07

Highlights: • Adhesion secretions of desert locust analyzed by GC–MS. • Insect secretions are composed of apolar and polar constituents. • Sampling simplified with contact SPME as compared to solvent sampling. • Thin-film SPME-GC–MS revealed complex alkane patterns for insect secretions. • Differences in tarsal (feet) secretions and samples from tibiae (upper legs) identified. - Abstract: This article reports on the chemical analysis of molecular profiles of tarsal secretions of the desert locust Schistocerca gregaria (Forsskål, 1775) by gas chromatography hyphenated with quadrupol mass spectrometry (GC–MS) as well as {sup 1}H-nuclear magnetic resonance ({sup 1}H NMR) spectroscopy. Special focus of this study was to elaborate on sampling methods which enable selective microscale extraction of insect secretions in a spatially controlled manner, in particular tarsal adhesive secretions and secretions located on cuticle surfaces at the tibia. Various solvent sampling procedures and contact solid-phase microextraction (SPME) methods were compared in terms of comprehensiveness and extraction efficiencies as measured by signal intensities in GC–MS. Solvent sampling with water as extraction solvent gave access to the elucidation of chemical profiles of polar compound classes such as amino acids and carbohydrates, but is extremely tedious. Contact SPME on the other hand can be regarded as a simplified and more elegant alternative, in particular for the lipophilic compound fraction. Many proteinogenic amino acids and ornithine as well as carbohydrate monomers arabinose, xylose, glucose, and galactose were detected in tarsal secretions after acid hydrolysis of aqueous extracts. Qualitatively similar but quantitatively significantly different molecular profiles were found for the lipid fraction which contained mainly n-alkanes and internally branched monomethyl-, dimethyl-, and trimethyl-alkanes in the C23–C49 range as well as long chain fatty acids and

Analysis of chemical profiles of insect adhesion secretions by gas chromatography–mass spectrometry

International Nuclear Information System (INIS)

Reitz, Manuela; Gerhardt, Heike; Schmitt, Christian; Betz, Oliver; Albert, Klaus; Lämmerhofer, Michael

2015-01-01

Highlights: • Adhesion secretions of desert locust analyzed by GC–MS. • Insect secretions are composed of apolar and polar constituents. • Sampling simplified with contact SPME as compared to solvent sampling. • Thin-film SPME-GC–MS revealed complex alkane patterns for insect secretions. • Differences in tarsal (feet) secretions and samples from tibiae (upper legs) identified. - Abstract: This article reports on the chemical analysis of molecular profiles of tarsal secretions of the desert locust Schistocerca gregaria (Forsskål, 1775) by gas chromatography hyphenated with quadrupol mass spectrometry (GC–MS) as well as 1 H-nuclear magnetic resonance ( 1 H NMR) spectroscopy. Special focus of this study was to elaborate on sampling methods which enable selective microscale extraction of insect secretions in a spatially controlled manner, in particular tarsal adhesive secretions and secretions located on cuticle surfaces at the tibia. Various solvent sampling procedures and contact solid-phase microextraction (SPME) methods were compared in terms of comprehensiveness and extraction efficiencies as measured by signal intensities in GC–MS. Solvent sampling with water as extraction solvent gave access to the elucidation of chemical profiles of polar compound classes such as amino acids and carbohydrates, but is extremely tedious. Contact SPME on the other hand can be regarded as a simplified and more elegant alternative, in particular for the lipophilic compound fraction. Many proteinogenic amino acids and ornithine as well as carbohydrate monomers arabinose, xylose, glucose, and galactose were detected in tarsal secretions after acid hydrolysis of aqueous extracts. Qualitatively similar but quantitatively significantly different molecular profiles were found for the lipid fraction which contained mainly n-alkanes and internally branched monomethyl-, dimethyl-, and trimethyl-alkanes in the C23–C49 range as well as long chain fatty acids and aldehydes

Gamma-knife surgery for secreting pituitary adenomas

International Nuclear Information System (INIS)

Morange-Ramos, I.; Andrieu, J.M.; Jaquet, P.; Regis, J.; Dufour, H.; Grisoli, F.; Peragut, J.C.

1998-01-01

We report our preliminary results concerning 25 patients with secreting pituitary adenomas treated with stereotactic radiosurgery after partial transsphenoidal surgery and followed over a 6-36 month-period. Among the 15 acromegalic patients, a decrease of 65% in mean GH levels was achieved after 6 months and of 77% at 12 months after radiosurgery. Presently, only 3 patients (20%) are considered as in remission (mean GH and IGF1 level into the normal range). A decrease of 46% and 64% was observed at 6 and 12 months after radiosurgery in 4 patients with prolactinomas although no normalization of PRL levels occurred. Presently, 3/4 patients have individual PRL levels slightly above the normal range. A normalization of Urinary Free Cortisol (UFC) was noticed in 4/6 (66%) patients with Cushing's disease within 6-12 months. No pituitary deficiency was noticed in this series with the exception of 4/25 patients (16%) who received subtotal or total pituitary irradiation for post-operative remnants of secreting adenomas poorly defined on MRI. One woman, who had undergone previously a conventional irradiation and presenting with a cavernous sinus adenoma reaching the optic nerve, developed an optic neuropathy. A second woman, with a cavernous sinus remnant, presented a cranial nerve palsy (VI) after the irradiation. We can conclude that radiosurgery using the Cobalt-60 Gamma-unit is, at least, as effective as conventional radiotherapy in the control of pituitary hormone hypersecretion from postoperative adenomas remnants with less adverse effects. (author)

Unconventional Pathways of Secretion Contribute to Inflammation

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Michael J. D. Daniels

2017-01-01

Full Text Available In the conventional pathway of protein secretion, leader sequence-containing proteins leave the cell following processing through the endoplasmic reticulum (ER and Golgi body. However, leaderless proteins also enter the extracellular space through mechanisms collectively known as unconventional secretion. Unconventionally secreted proteins often have vital roles in cell and organism function such as inflammation. Amongst the best-studied inflammatory unconventionally secreted proteins are interleukin (IL-1β, IL-1α, IL-33 and high-mobility group box 1 (HMGB1. In this review we discuss the current understanding of the unconventional secretion of these proteins and highlight future areas of research such as the role of nuclear localisation.

Proton pump inhibitors inhibit pancreatic secretion

DEFF Research Database (Denmark)

Wang, Jing; Barbuskaite, Dagne; Tozzi, Marco

2015-01-01

+/K+-ATPases are expressed and functional in human pancreatic ducts and whether proton pump inhibitors (PPIs) have effect on those. Here we show that the gastric HKα1 and HKβ subunits (ATP4A; ATP4B) and non-gastric HKα2 subunits (ATP12A) of H+/K+-ATPases are expressed in human pancreatic cells. Pumps have similar...... of major ions in secretion follow similar excretory curves in control and PPI treated animals. In addition to HCO3-, pancreas also secretes K+. In conclusion, this study calls for a revision of the basic model for HCO3- secretion. We propose that proton transport is driving secretion, and that in addition...

Hoopoes color their eggs with antimicrobial uropygial secretions

Science.gov (United States)

Soler, Juan J.; Martín-Vivaldi, M.; Peralta-Sánchez, J. M.; Arco, L.; Juárez-García-Pelayo, N.

2014-09-01

Uropygial gland secretions are used as cosmetics by some species of birds to color and enhance properties of feathers and teguments, which may signal individual quality. Uropygial secretions also reach eggshells during incubation and, therefore, may influence the coloration of birds' eggs, a trait that has attracted the attention of evolutionary biologists for more than one century. The color of hoopoe eggs typically changes along incubation, from bluish-gray to greenish-brown. Here, we test experimentally the hypothesis that dark uropygial secretion of females is responsible for such drastic color change. Moreover, since uropygial secretion of hoopoes has antimicrobial properties, we also explore the association between color and antimicrobial activity of the uropygial secretion of females. We found that eggs stayed bluish-gray in nests where female access to the uropygial secretion was experimentally blocked. Furthermore, experimental eggs that were maintained in incubators and manually smeared with uropygial secretion experienced similar color changes that naturally incubated eggs did, while control eggs that were not in contact with the secretions did not experience such color changes. All these results strongly support the hypothesis that female hoopoes use their uropygial gland secretion to color the eggs. Moreover, saturation of the uropygial secretion was associated with antimicrobial activity against Bacillus licheniformis. Given the known antimicrobial potential of uropygial secretions of birds, this finding opens the possibility that in scenarios of sexual selection, hoopoes in particular and birds in general signal antimicrobial properties of their uropygial secretion by mean of changes in egg coloration along incubation.

The role of jasmonates in floral nectar secretion.

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Venkatesan Radhika

Full Text Available Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants.

Secret-key expansion from covert communication

Science.gov (United States)

Arrazola, Juan Miguel; Amiri, Ryan

2018-02-01

Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.

Proteomic identification of secreted proteins of Propionibacterium acnes

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Holland Carsten

2010-08-01

Full Text Available Abstract Background The anaerobic Gram-positive bacterium Propionibacterium acnes is a human skin commensal that resides preferentially within sebaceous follicles; however, it also exhibits many traits of an opportunistic pathogen, playing roles in a variety of inflammatory diseases such as acne vulgaris. To date, the underlying disease-causing mechanisms remain ill-defined and knowledge of P. acnes virulence factors remains scarce. Here, we identified proteins secreted during anaerobic cultivation of a range of skin and clinical P. acnes isolates, spanning the four known phylogenetic groups. Results Culture supernatant proteins of P. acnes were separated by two-dimensional electrophoresis (2-DE and all Coomassie-stained spots were subsequently identified by MALDI mass spectrometry (MALDI-MS. A set of 20 proteins was secreted in the mid-exponential growth phase by the majority of strains tested. Functional annotation revealed that many of these common proteins possess degrading activities, including glycoside hydrolases with similarities to endoglycoceramidase, β-N-acetylglucosaminidase and muramidase; esterases such as lysophospholipase and triacylglycerol lipase; and several proteases. Other secreted factors included Christie-Atkins-Munch-Petersen (CAMP factors, glyceraldehyde 3-phosphate dehydrogenase (GAPDH, and several hypothetical proteins, a few of which are unique to P. acnes. Strain-specific differences were apparent, mostly in the secretion of putative adhesins, whose genes exhibit variable phase variation-like sequence signatures. Conclusions Our proteomic investigations have revealed that the P. acnes secretome harbors several proteins likely to play a role in host-tissue degradation and inflammation. Despite a large overlap between the secretomes of all four P. acnes phylotypes, distinct differences between predicted host-tissue interacting proteins were identified, providing potential insight into the differential virulence

Pancreatic bicarbonate secretion involves two proton pumps

DEFF Research Database (Denmark)

Novak, Ivana; Wang, Jing; Henriksen, Katrine L.

2011-01-01

Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium expres...

Gastric secretion elicited by conditioning in rats.

Science.gov (United States)

Caboclo, José Liberato Ferreira; Cury, Francico de Assis; Borin, Aldenis Albanese; Caboclo, Luís Otávio Sales Ferreira; Ribeiro, Maria Fernanda Sales Caboclo; de Freitas, Pedro José; Andersson, Sven

2009-01-01

To investigate whether interdigestive gastric acid secretion can be controlled by a possible memory-related cortical mechanism. To evaluate gastric secretion in rats, we used a methodology that allows gastric juice collection in rats in their habitual conditions (without any restraining) by pairing sound as the conditioning stimulus (CS) and food as the unconditioning stimulus (US). The levels of gastric acid secretion under basal conditions and under sound stimulation were recorded and the circulating gastrin levels determined. When the gastric juice was collected in the course of the conditioning procedure, the results showed that under noise stimulation a significant increase in gastric acid secretion occurred after 10 days of conditioning (p<0.01). The significance was definitively demonstrated after 13 days of conditioning (p<0.001). Basal secretions of the conditioned rats reached a significant level after 16 days of conditioning. The levels of noise-stimulated gastric acid secretion were the highest so far described in physiological experiments carried out in rats and there were no significant increases in the circulating gastrin levels. The results point to the important role played by cortical structures in the control of interdigestive gastric acid secretion in rats. If this mechanism is also present in humans, it may be involved in diseases caused by inappropriate gastric acid secretion during the interprandial periods.

Chemical constituents of the femoral gland secretions of male tegu lizards (Tupinambis merianae) (Family teiidae).

Science.gov (United States)

Martín, José; Chamut, Silvia; Manes, Mario E; López, Pilar

2011-01-01

In spite of the importance of chemical signals (pheromones) in the reproductive behaviour of lizards, the chemical compounds secreted by their femoral glands, which may be used as sexual signals, are only known for a few lizard species. Based on mass spectra, obtained by GC-MS, we found 49 lipophilic compounds in femoral gland secretions of male tegu lizards (Tupinambis merianae) (fam. Teiidae), including a very high proportion of carboxylic acids and their esters ranging between n-C8 and n-C20 (mainly octadecanoic and 9,12-octadecadienoic acids), with much less proportions of steroids, tocopherol, aldehydes, and squalene. We discuss the potential function of these compounds in secretions, and compare the compounds found here with those documented for other lizard species.

Air Force UAV’s: The Secret History

Science.gov (United States)

2010-07-01

iA Mitchell Institute Study i Air Force UAVs The Secret History A Mitchell Institute Study July 2010 By Thomas P. Ehrhard Report Documentation Page...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Air Force UAVs The Secret History 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c... The Secret History 2 Air Force UAVs: The Secret History2 air Force uaVs: The secret history Has any airplane in the past decade captured the public

A quantum secret-sharing protocol with fairness

International Nuclear Information System (INIS)

Liu, Feng; Qin, Su-Juan; Wen, Qiao-Yan

2014-01-01

A quantum secret-sharing (QSS) protocol consists of two main phases, called sharing and reconstruction. In the first phase, the dealer selects a secret, divides it into several shares, and sends each participant its share securely with a quantum channel. In the second phase, the participants run an interactive protocol in order to reconstruct the secret. If the participants can communicate via a broadcast channel, they can show their shares and learn the secrets simultaneously. So what happens if the channel is not simultaneous? In this paper, we propose a QSS protocol with cheaters by using partially and maximally entangled states. A secure and fair reconstruction mechanism is designed, in a way that each participant can learn or cannot learn the secret simultaneously. (papers)

Trade secrets protection mode of nuclear power plant

International Nuclear Information System (INIS)

Zeng Bin

2015-01-01

The paper analyzes the legal environment in which nuclear power enterprises are stayed, and mainly discusses the business secret protection modes of China's nuclear power enterprises. It is expected to provide a revelation and help for these enterprises to protect their business secrets. Firstly, the paper briefly expounds the legal basis of business secret protection and China's legalization status in this regard. Then it mainly puts forward the business secret management framework and postulations for nuclear power enterprises, and key points in application and protection of nuclear power business secret. (author)

High rates of intestinal bicarbonate secretion in seawater tilapia (Oreochromis mossambicus).

Science.gov (United States)

Ruiz-Jarabo, I; Gregório, S F; Gaetano, P; Trischitta, F; Fuentes, J

2017-05-01

Osmoregulation in fish is a complex process that requires the orchestrated cooperation of many tissues. In fish facing hyperosmotic environments, the intestinal absorption of some monovalent ions and the secretion of bicarbonate are key processes to favor water absorption. In the present study, we showed that bicarbonate levels in the intestinal fluid are several fold higher in seawater than in freshwater acclimated tilapia (Oreochromis mossambicus). In addition, we analyzed gene expression of the main molecular mechanisms involved in HCO 3 - movements i.e. slc26a6, slc26a3, slc4a4 and v-type H-ATPase sub C in the intestine of tilapia acclimated to both seawater and freshwater. Our results show an anterior/posterior functional regionalization of the intestine in tilapia in terms of expression patterns, which is affected by environmental salinity mostly in the anterior and mid intestine. Analysis of bicarbonate secretion using pH-Stat in tissues mounted in Ussing chambers reveals high rates of bicarbonate secretion in tilapia acclimated to seawater from anterior intestine to rectum ranging between ~900 and ~1700nmolHCO 3 - cm -2 h -1 . However, a relationship between the expression of slc26a6, slc26a3, slc4a4 and the rate of bicarbonate secretion seems to be compromised in the rectum. In this region, the low expression of the bicarbonate transporters could not explain the high bicarbonate secretion rates here described. However, we postulate that the elevated v-type H-ATPase mRNA expression in the rectum could be involved in this process. Copyright © 2017 Elsevier Inc. All rights reserved.

Ionizing radiation in secret services' conspirative actions

International Nuclear Information System (INIS)

Vogel, H.; Lotz, P.; Vogel, B.

2007-01-01

Introduction: The death of Litvinenko has been reported by the media. It has raised the question whether this case had been unique. The fall of the wall has allowed a glimpse in the planning and comporting of a secret service. Material and method: Documents of the secret service of the former German democratic republic (GDR), books of defectors, and media reports about secret service actions with radiating substances have been analyzed. Results: Since decades, secret services have been using radioactive nuclides and radiation for their tasks. Several killings with radiation have been reported. A complicated logistic had been developed. Conclusion: Only singular cases of the employment of radiating substances have become known. It is probable that the majority rests unknown. Government support seems necessary in secret services' conspirative actions with radiating substance

Regulation of glucagon secretion by incretins

DEFF Research Database (Denmark)

Holst, Jens Juul; Christensen, M; Lund, A

2011-01-01

Glucagon secretion plays an essential role in the regulation of hepatic glucose production, and elevated fasting and postprandial plasma glucagon concentrations in patients with type 2 diabetes (T2DM) contribute to their hyperglycaemia. The reason for the hyperglucagonaemia is unclear, but recent...... studies have shown lack of suppression after oral but preserved suppression after isoglycaemic intravenous glucose, pointing to factors from the gut. Gastrointestinal hormones that are secreted in response to oral glucose include glucagon-like peptide-1 (GLP-1) that strongly inhibits glucagon secretion......, and GLP-2 and GIP, both of which stimulate secretion. When the three hormones are given together on top of isoglycaemic intravenous glucose, glucagon suppression is delayed in a manner similar to that observed after oral glucose. Studies with the GLP-1 receptor antagonist, exendin 9-39, suggest...

Role of adipose secreted factors and kisspeptin in the metabolic control of gonadotropin secretion and puberty

Science.gov (United States)

Factors secreted by adipose tissue continue to be discovered. Evidence indicates a strong link between neural influences and adipocyte expression and secretion of a wide array of cytokines, neurotrophic factors, growth factors, binding proteins, and neuropeptides. These “adipokines” are linked to im...

Burkholderia cenocepacia type VI secretion system mediates escape of type II secreted proteins into the cytoplasm of infected macrophages.

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Roberto Rosales-Reyes

Full Text Available Burkholderia cenocepacia is an opportunistic pathogen that survives intracellularly in macrophages and causes serious respiratory infections in patients with cystic fibrosis. We have previously shown that bacterial survival occurs in bacteria-containing membrane vacuoles (BcCVs resembling arrested autophagosomes. Intracellular bacteria stimulate IL-1β secretion in a caspase-1-dependent manner and induce dramatic changes to the actin cytoskeleton and the assembly of the NADPH oxidase complex onto the BcCV membrane. A Type 6 secretion system (T6SS is required for these phenotypes but surprisingly it is not required for the maturation arrest of the BcCV. Here, we show that macrophages infected with B. cenocepacia employ the NLRP3 inflammasome to induce IL-1β secretion and pyroptosis. Moreover, IL-1β secretion by B. cenocepacia-infected macrophages is suppressed in deletion mutants unable to produce functional Type VI, Type IV, and Type 2 secretion systems (SS. We provide evidence that the T6SS mediates the disruption of the BcCV membrane, which allows the escape of proteins secreted by the T2SS into the macrophage cytoplasm. This was demonstrated by the activity of fusion derivatives of the T2SS-secreted metalloproteases ZmpA and ZmpB with adenylcyclase. Supporting this notion, ZmpA and ZmpB are required for efficient IL-1β secretion in a T6SS dependent manner. ZmpA and ZmpB are also required for the maturation arrest of the BcCVs and bacterial intra-macrophage survival in a T6SS-independent fashion. Our results uncover a novel mechanism for inflammasome activation that involves cooperation between two bacterial secretory pathways, and an unanticipated role for T2SS-secreted proteins in intracellular bacterial survival.

Mucous solids and liquid secretion by airways: studies with normal pig, cystic fibrosis human, and non-cystic fibrosis human bronchi

Science.gov (United States)

Martens, Chelsea J.; Inglis, Sarah K.; Valentine, Vincent G.; Garrison, Jennifer; Conner, Gregory E.

2011-01-01

To better understand how airways produce thick airway mucus, nonvolatile solids were measured in liquid secreted by bronchi from normal pig, cystic fibrosis (CF) human, and non-CF human lungs. Bronchi were exposed to various secretagogues and anion secretion inhibitors to induce a range of liquid volume secretion rates. In all three groups, the relationship of solids concentration (percent nonvolatile solids) to liquid volume secretion rate was curvilinear, with higher solids concentration associated with lower rates of liquid volume secretion. In contrast, the secretion rates of solids mass and water mass as functions of liquid volume secretion rates exhibited positive linear correlations. The y-intercepts of the solids mass-liquid volume secretion relationships for all three groups were positive, thus accounting for the higher solids concentrations in airway liquid at low rates of secretion. Predictive models derived from the solids mass and water mass linear equations fit the experimental percent solids data for the three groups. The ratio of solids mass secretion to liquid volume secretion was 5.2 and 2.4 times higher for CF bronchi than for pig and non-CF bronchi, respectively. These results indicate that normal pig, non-CF human, and CF human bronchi produce a high-percent-solids mucus (>8%) at low rates of liquid volume secretion (≤1.0 μl·cm−2·h−1). However, CF bronchi produce mucus with twice the percent solids (∼8%) of pig or non-CF human bronchi at liquid volume secretion rates ≥4.0 μl·cm−2·h−1. PMID:21622844

Visualization of glucagon secretion from pancreatic α cells by bioluminescence video microscopy: Identification of secretion sites in the intercellular contact regions

International Nuclear Information System (INIS)

Yokawa, Satoru; Suzuki, Takahiro; Inouye, Satoshi; Inoh, Yoshikazu; Suzuki, Ryo; Kanamori, Takao; Furuno, Tadahide; Hirashima, Naohide

2017-01-01

We have firstly visualized glucagon secretion using a method of video-rate bioluminescence imaging. The fusion protein of proglucagon and Gaussia luciferase (PGCG-GLase) was used as a reporter to detect glucagon secretion and was efficiently expressed in mouse pancreatic α cells (αTC1.6) using a preferred human codon-optimized gene. In the culture medium of the cells expressing PGCG-GLase, luminescence activity determined with a luminometer was increased with low glucose stimulation and KCl-induced depolarization, as observed for glucagon secretion. From immunochemical analyses, PGCG-GLase stably expressed in clonal αTC1.6 cells was correctly processed and released by secretory granules. Luminescence signals of the secreted PGCG-GLase from the stable cells were visualized by video-rate bioluminescence microscopy. The video images showed an increase in glucagon secretion from clustered cells in response to stimulation by KCl. The secretory events were observed frequently at the intercellular contact regions. Thus, the localization and frequency of glucagon secretion might be regulated by cell-cell adhesion. - Highlights: • The fused protein of proglucagon to Gaussia luciferase was used as a reporter. • The fusion protein was highly expressed using a preferred human-codon optimized gene. • Glucagon secretion stimulated by depolarization was determined by luminescence. • Glucagon secretion in α cells was visualized by bioluminescence imaging. • Glucagon secretion sites were localized in the intercellular contact regions.

29 CFR 1903.9 - Trade secrets.

Science.gov (United States)

2010-07-01

... INSPECTIONS, CITATIONS AND PROPOSED PENALTIES § 1903.9 Trade secrets. (a) Section 15 of the Act provides: “All... concerns or relates to the trade secrets, processes, operations, style of work, or apparatus, or to the...

Air Force UAVs: The Secret History

Science.gov (United States)

2010-07-01

iA Mitchell Institute Study i Air Force UAVs The Secret History A Mitchell Institute Study July 2010 By Thomas P. Ehrhard Report Documentation Page...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Air Force UAVs The Secret History 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...opening phases of Operation Enduring Freedom in Afghanistan. By Thomas P. Ehrhard a miTchEll insTiTuTE sTudy July 2010 Air Force UAVs The Secret History

THE BUFFER CAPACITY OF AIRWAY EPITHELIAL SECRETIONS

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Dusik eKim

2014-06-01

Full Text Available The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF. The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 µl volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO3- is the major buffer. Peak buffer capacity (β increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO3- secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO3- secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions.

The ESX system in Bacillus subtilis mediates protein secretion.

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Laura A Huppert

Full Text Available Esat-6 protein secretion systems (ESX or Ess are required for the virulence of several human pathogens, most notably Mycobacterium tuberculosis and Staphylococcus aureus. These secretion systems are defined by a conserved FtsK/SpoIIIE family ATPase and one or more WXG100 family secreted substrates. Gene clusters coding for ESX systems have been identified amongst many organisms including the highly tractable model system, Bacillus subtilis. In this study, we demonstrate that the B. subtilis yuk/yue locus codes for a nonessential ESX secretion system. We develop a functional secretion assay to demonstrate that each of the locus gene products is specifically required for secretion of the WXG100 virulence factor homolog, YukE. We then employ an unbiased approach to search for additional secreted substrates. By quantitative profiling of culture supernatants, we find that YukE may be the sole substrate that depends on the FtsK/SpoIIIE family ATPase for secretion. We discuss potential functional implications for secretion of a unique substrate.

Literature mining supports a next-generation modeling approach to predict cellular byproduct secretion

DEFF Research Database (Denmark)

King, Zachary A.; O'Brien, Edward J.; Feist, Adam M.

2017-01-01

metabolic byproduct secretion with bottom-up reconstructions of metabolic networks. However, owing to a lack of data, it has not been possible to validate these predictions across a wide range of strains and conditions. Through literature mining, we were able to generate a database of Escherichia coli...

Extrafloral nectar secretion from wounds of Solanum dulcamara.

Science.gov (United States)

Lortzing, Tobias; Calf, Onno W; Böhlke, Marlene; Schwachtje, Jens; Kopka, Joachim; Geuß, Daniel; Kosanke, Susanne; van Dam, Nicole M; Steppuhn, Anke

2016-04-25

Plants usually close wounds rapidly to prevent infections and the loss of valuable resources such as assimilates(1). However, herbivore-inflicted wounds on the bittersweet nightshade Solanum dulcamara appear not to close completely and produce sugary wound secretions visible as droplets. Many plants across the plant kingdom secrete sugary nectar from extrafloral nectaries(2) to attract natural enemies of herbivores for indirect defence(3,4). As ants forage on wound edges of S. dulcamara in the field, we hypothesized that wound secretions are a form of extrafloral nectar (EFN). We show that, unlike EFN from known nectaries, wound secretions are neither associated with any specific structure nor restricted to certain locations. However, similar to EFN, they are jasmonate-inducible and the plant controls their chemical composition. Wound secretions are attractive for ants, and application of wound secretion mimics increases ant attraction and reduces herbivory on S. dulcamara plants in a natural population. In greenhouse experiments, we reveal that ants can defend S. dulcamara from two of its native herbivores, slugs and flea beetle larvae. Since nectar is defined by its ecological function as a sugary secretion involved in interactions with animals(5), such 'plant bleeding' could be a primitive mode of nectar secretion exemplifying an evolutionary origin of structured extrafloral nectaries.

Incretin hormone secretion over the day

DEFF Research Database (Denmark)

Ahren, B; Carr, RD; Deacon, Carolyn F.

2010-01-01

The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years. Regulat......The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years....... Regulation of incretin hormone secretion is less well characterized. The main stimulus for incretin hormone secretion is presence of nutrients in the intestinal lumen, and carbohydrate, fat as well as protein all have the capacity to stimulate GIP and GLP-1 secretion. More recently, it has been established...... that a diurnal regulation exists with incretin hormone secretion to an identical meal being greater when the meal is served in the morning compared to in the afternoon. Finally, whether incretin hormone secretion is altered in disease states is an area with, so far, controversial results in different studies...

Exosome secretion affects social motility in Trypanosoma brucei.

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Dror Eliaz

2017-03-01

Full Text Available Extracellular vesicles (EV secreted by pathogens function in a variety of biological processes. Here, we demonstrate that in the protozoan parasite Trypanosoma brucei, exosome secretion is induced by stress that affects trans-splicing. Following perturbations in biogenesis of spliced leader RNA, which donates its spliced leader (SL exon to all mRNAs, or after heat-shock, the SL RNA is exported to the cytoplasm and forms distinct granules, which are then secreted by exosomes. The exosomes are formed in multivesicular bodies (MVB utilizing the endosomal sorting complexes required for transport (ESCRT, through a mechanism similar to microRNA secretion in mammalian cells. Silencing of the ESCRT factor, Vps36, compromised exosome secretion but not the secretion of vesicles derived from nanotubes. The exosomes enter recipient trypanosome cells. Time-lapse microscopy demonstrated that cells secreting exosomes or purified intact exosomes affect social motility (SoMo. This study demonstrates that exosomes are delivered to trypanosome cells and can change their migration. Exosomes are used to transmit stress signals for communication between parasites.

Reappraisal of bicarbonate secretion by the human oesophagus

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, J; Bukhave, Klaus

1997-01-01

BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosalbicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophagealbicarbonate secretion and thus......: The median rates (95% confidence intervals)of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203)mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and gastric bicarbonate...... be overestimated. As omeprazole and ranitidine did not affect bicarbonate secretion differently there was no evidence that omeprazole acts on icarbonate secretory cells in the oesophageal mucosa....

Indomethacin decreases gastroduodenal mucosal bicarbonate secretion in humans

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

1995-01-01

BACKGROUND: Cyclooxygenase inhibitors reduce mucosal bicarbonate secretion in the duodenum, but the evidence for their effect on bicarbonate secretion in the stomach remains controversial. We have, therefore, studied how indomethacin influences gastroduodenal bicarbonate secretion and luminal...... healthy volunteers. Bicarbonate and PGE2 were measured in the gastroduodenal effluents by back-titration and radioimmunoassay, respectively. RESULTS: Vagal stimulation and duodenal luminal acidification (0.1 M HCl; 20 ml; 5 min) increased gastroduodenal bicarbonate secretion (p ... markedly inhibited both basal and stimulated gastric and duodenal mucosal bicarbonate secretion, and this reduction was similar to the degree of cyclooxygenase inhibition estimated by the luminal release of PGE2 (p

[Secret drug tribulations and French legislation].

Science.gov (United States)

Charlot, Colette

2002-01-01

From an official Montpellier prefecture paper of 18th century, we are interested in a secret drug from Provence origin: the Irroë powder. This purgative will pass from "secret" drug status to "patent" drug. It's notoriety will come from its arrival to Paris. The law of 21th germinal year XI, the decret of 25 prairial year XIII and this of 18th 1810 imposed to give the drug composition to an official status; that examined and permit it's sale. This secret will be produce for half century.

Low cost of gastric acid secretion during digestion in ball pythons.

Science.gov (United States)

Nørgaard, Simon; Andreassen, Kim; Malte, Christian Lind; Enok, Sanne; Wang, Tobias

2016-04-01

Due to their large metabolic responses to digestion (specific dynamic action, SDA), snakes represent an interesting animal group to identify the underlying mechanisms for the postprandial rise in metabolism. The SDA response results from the energetic costs of many different processes ranging over prey handling, secretions by the digestive system, synthesis of enzymes, plasticity of most visceral organs, as well as protein synthesis and nitrogen excretion. The contribution of the individual mechanisms, however, remains elusive. Gastric acid secretion has been proposed to account for more than half of the SDA response, while other studies report much lower contributions of the gastric processes. To investigate the energetic cost of gastric acid secretion, ball pythons (Python regius) were fed meals with added amounts of bone meal (up to 25 g bone meal kg(-1) snake) to achieve a five-fold rise in the buffer capacity of the meals. Direct measurements within the stomach lumen showed similar reduction in gastric pH when buffer capacity was increased, but we found no effects on the rise in oxygen consumption over the first three days of digestion. There was, however, a slower return of oxygen consumption to resting baseline. We conclude that gastric acid secretion only contributes modestly to the SDA response and propose that post-absorptive processes, such as increased protein synthesis, are likely to underlie the SDA response. Copyright © 2016 Elsevier Inc. All rights reserved.

SECURE VISUAL SECRET SHARING BASED ON DISCRETE WAVELET TRANSFORM

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S. Jyothi Lekshmi

2015-08-01

Full Text Available Visual Cryptography Scheme (VCS is an encryption method to encode secret written materials. This method converts the secret written material into an image. Then encode this secret image into n shadow images called shares. For the recreation of the original secret, all or some selected subsets of shares are needed; individual shares are of no use on their own. The secret image can be recovered simply by selecting some subset of these n shares, makes transparencies of them and stacking on top of each other. Nowadays, the data security has an important role. The shares can be altered by an attacker. So providing security to the shares is important. This paper proposes a method of adding security to cryptographic shares. This method uses two dimensional discrete wavelet transform to hide visual secret shares. Then the hidden secrets are distributed among participants through the internet. All hidden shares are extracted to reconstruct the secret.

On Secret Sharing with Nonlinear Product Reconstruction

DEFF Research Database (Denmark)

Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego

2015-01-01

Multiplicative linear secret sharing is a fundamental notion in the area of secure multiparty computation and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees that the product of two secrets is obtained as a linear function of the vector......-necessarily-linear “product reconstruction function.” Is the resulting notion equivalent to multiplicative linear secret sharing? We show the (perhaps somewhat counterintuitive) result that this relaxed notion is strictly more general. Concretely, fix a finite field ${\\mathbb F}_q$ as the base field over which linear secret...... sharing is considered. Then we show there exists an (exotic) linear secret sharing scheme with an unbounded number of players $n$ such that it has $t$-privacy with $t = \\Omega(n)$ and such that it does admit a product reconstruction function, yet this function is necessarily nonlinear. In addition, we...

Reelin secreted by GABAergic neurons regulates glutamate receptor homeostasis.

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Cecilia Gonzalez Campo

Full Text Available BACKGROUND: Reelin is a large secreted protein of the extracellular matrix that has been proposed to participate to the etiology of schizophrenia. During development, reelin is crucial for the correct cytoarchitecture of laminated brain structures and is produced by a subset of neurons named Cajal-Retzius. After birth, most of these cells degenerate and reelin expression persists in postnatal and adult brain. The phenotype of neurons that bind secreted reelin and whether the continuous secretion of reelin is required for physiological functions at postnatal stages remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Combining immunocytochemical and pharmacological approaches, we first report that two distinct patterns of reelin expression are present in cultured hippocampal neurons. We show that in hippocampal cultures, reelin is secreted by GABAergic neurons displaying an intense reelin immunoreactivity (IR. We demonstrate that secreted reelin binds to receptors of the lipoprotein family on neurons with a punctate reelin IR. Secondly, using calcium imaging techniques, we examined the physiological consequences of reelin secretion blockade. Blocking protein secretion rapidly and reversibly changes the subunit composition of N-methyl-D-aspartate glutamate receptors (NMDARs to a predominance of NR2B-containing NMDARs. Addition of recombinant or endogenously secreted reelin rescues the effects of protein secretion blockade and reverts the fraction of NR2B-containing NMDARs to control levels. Therefore, the continuous secretion of reelin is necessary to control the subunit composition of NMDARs in hippocampal neurons. CONCLUSIONS/SIGNIFICANCE: Our data show that the heterogeneity of reelin immunoreactivity correlates with distinct functional populations: neurons synthesizing and secreting reelin and/or neurons binding reelin. Furthermore, we show that continuous reelin secretion is a strict requirement to maintain the composition of NMDARs. We propose

Melatonin Secretion Pattern in Critically Ill Patients

DEFF Research Database (Denmark)

Boyko, Yuliya; Holst, René; Jennum, Poul

2017-01-01

effect of remifentanil on melatonin secretion. We found that the risk of atypical sleep compared to normal sleep was significantly lower (p REM) sleep was only observed during the nonsedation period. We found preserved diurnal pattern of melatonin...... secretion in these patients. Remifentanil did not affect melatonin secretion but was associated with lower risk of atypical sleep pattern. REM sleep was only registered during the period of nonsedation.......Critically ill patients have abnormal circadian and sleep homeostasis. This may be associated with higher morbidity and mortality. The aims of this pilot study were (1) to describe melatonin secretion in conscious critically ill mechanically ventilated patients and (2) to describe whether melatonin...

Thymidine secretion by hybridoma and myeloma cells

International Nuclear Information System (INIS)

Spilsberg, Bjorn; Rise, Frode; Petersen, Dirk; Nissen-Meyer, Jon

2006-01-01

Secretion of thymidine appeared to be a common property of hybridoma and myeloma cells, but not of other cell types, which were tested. Of three hybridoma cell lines tested, all secreted thymidine in amounts resulting in the accumulation of thymidine to concentrations of 10-20 μM in the culture medium. Also three of five myeloma cell lines that were analyzed secrete thymidine, but none of the other cell types that were studied. Thymidine was purified to homogeneity (4 mg purified from 3 l of culture medium) and identified as such by nuclear magnetic resonance spectroscopy. The cells that secreted thymidine showed high resistance to the growth inhibitory effect of thymidine

Intermittent subglottic secretion drainage may cause tracheal damage in patients with few oropharyngeal secretions.

Science.gov (United States)

Suys, E; Nieboer, K; Stiers, W; De Regt, J; Huyghens, L; Spapen, H

2013-12-01

Injurious prolapse of tracheal mucosa into the suction port has been reported in up to 50% of intubated patients receiving continuous aspiration of subglottic secretions. We investigated whether similar injury could be inflicted by automated intermittent aspiration. Six consecutive patients, intubated with the Mallinckrodt TaperGuard Evac™ endotracheal tube, were studied. A flow sensor was placed between the vacuum regulating system and the mucus collector. Intermittent suctioning was performed at a pressure of -125 mmHg with a 25s interval and duration of 15s. After 24h, a CT scan of the tracheal region was performed. Excessive negative suction pressure, a fast drop in aspiration flow to zero, and important "swinging" movements of secretions in the evacuation line were observed in all patients. Oral instillation of antiseptic mouthwash restored normal aspiration flow and secretion mobility. CT imaging showed marked entrapment of tracheal mucosa into the suction port in all patients. In patients with few oropharyngeal secretions, automated intermittent subglottic aspiration may result in significant and potential harmful invagination of tracheal mucosa into the suction lumen. A critical amount of fluid must be present in the oropharynx to assure adequate and safe aspiration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sagnac secret sharing over telecom fiber networks.

Science.gov (United States)

Bogdanski, Jan; Ahrens, Johan; Bourennane, Mohamed

2009-01-19

We report the first Sagnac quantum secret sharing (in three-and four-party implementations) over 1550 nm single mode fiber (SMF) networks, using a single qubit protocol with phase encoding. Our secret sharing experiment has been based on a single qubit protocol, which has opened the door to practical secret sharing implementation over fiber telecom channels and in free-space. The previous quantum secret sharing proposals were based on multiparticle entangled states, difficult in the practical implementation and not scalable. Our experimental data in the three-party implementation show stable (in regards to birefringence drift) quantum secret sharing transmissions at the total Sagnac transmission loop distances of 55-75 km with the quantum bit error rates (QBER) of 2.3-2.4% for the mean photon number micro?= 0.1 and 1.7-2.1% for micro= 0.3. In the four-party case we have achieved quantum secret sharing transmissions at the total Sagnac transmission loop distances of 45-55 km with the quantum bit error rates (QBER) of 3.0-3.7% for the mean photon number micro= 0.1 and 1.8-3.0% for micro?= 0.3. The stability of quantum transmission has been achieved thanks to our new concept for compensation of SMF birefringence effects in Sagnac, based on a polarization control system and a polarization insensitive phase modulator. The measurement results have showed feasibility of quantum secret sharing over telecom fiber networks in Sagnac configuration, using standard fiber telecom components.

Analysis of secreted proteins from Aspergillus flavus.

Science.gov (United States)

Medina, Martha L; Haynes, Paul A; Breci, Linda; Francisco, Wilson A

2005-08-01

MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3-O-glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1- and 2-DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin-, five to glucose- and one to potato dextrose-grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.

Secret-key rates and privacy leakage in biometric systems

NARCIS (Netherlands)

Ignatenko, T.

2009-01-01

In this thesis both the generation of secret keys from biometric data and the binding of secret keys to biometric data are investigated. These secret keys can be used to regulate access to sensitive data, services, and environments. In a biometric secrecy system a secret key is generated or chosen

Pituitary-hormone secretion by thyrotropinomas

OpenAIRE

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M.; Biermasz, Nienke R.; Smit, Jan W.; Frolich, Marijke; Keenan, Daniel M.; Veldhuis, Johannes D.; Romijn, Johannes A.

2008-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore ev...

Peptides and neurotransmitters that affect renin secretion

Science.gov (United States)

Ganong, W. F.; Porter, J. P.; Bahnson, T. D.; Said, S. I.

1984-01-01

Substance P inhibits renin secretion. This polypeptide is a transmitter in primary afferent neurons and is released from the peripheral as well as the central portions of these neurons. It is present in afferent nerves from the kidneys. Neuropeptide Y, which is a cotransmitter with norepinephrine and epinephrine, is found in sympathetic neurons that are closely associated with and presumably innervate the juxtagolmerular cells. Its effect on renin secretion is unknown, but it produces renal vasoconstriction and natriuresis. Vasoactive intestinal polypeptide (VIP) is a cotransmitter with acetylocholine in cholinergic neurons, and this polypeptide stimulates renin secretion. We cannot find any evidence for its occurence in neurons in the kidneys, but various stimuli increase plasma VIP to levels comparable to those produced by doses of exogenous VIP which stimulated renin secretion. Neostigmine increases plasma VIP and plasma renin activity, and the VIP appears to be responsible for the increase in renin secretion, since the increase is not blocked by renal denervation or propranolol. Stimulation of various areas in the brain produces sympathetically mediated increases in plasma renin activity associated with increases in blood pressure. However, there is pharmacological evidence that the renin response can be separated from the blood pressure response. In anaesthetized dogs, drugs that increase central serotonergic discharge increase renin secretion without increasing blood pressure. In rats, activation of sertonergic neurons in the dorsal raphe nucleus increases renin secretion by a pathway that projects from this nucleus to the ventral hypothalamus, and from there to the kidneys via the sympathetic nervous system. The serotonin releasing drug parachloramphetamine also increases plasma VIP, but VIP does not appear to be the primary mediator of the renin response. There is preliminary evidence that the serotonergic neurons in the dorsal raphe nucleus are part of the

Will They or Won't They? Secret Telling in Interpersonal Interactions.

Science.gov (United States)

Kowalski, Robin Marie; Morgan, Chad Alan; Whittaker, Elizabeth; Zaremba, Brittany; Frazee, Laura; Dean, Jessica

2015-01-01

This study investigated predictors of within-gender secret telling. Eighty-eight participants were exposed to either a "positive" or a "negative" secret about another individual. Just under 20% of participants told the secret. Conscientiousness, secret condition, empathy, and the conscientiousness by secret condition interaction had effects on the rate of secret telling, χ(2) (5,82) = 17.78, p = .003, AIC = 80.60. Conscientiousness had a negative effect on secret telling among participants that told the "negative" secret.

Combined contributions of over-secreted glucagon-like peptide 1 and suppressed insulin secretion to hyperglycemia induced by gatifloxacin in rats

Energy Technology Data Exchange (ETDEWEB)

Yu, Yunli, E-mail: chrisyu1255@yahoo.com.cn [Department of Pharmaceutics, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Wang, Xinting, E-mail: wxinting1986@yahoo.com.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Can, E-mail: ltsan@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Yao, Dan, E-mail: erinyao@126.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Shanghai Institute of Materia Medica, Shanghai 201203 (China); Hu, Mengyue, E-mail: juliahmy@126.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Li, Jia, E-mail: ljbzd@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Hu, Nan, E-mail: hn_324@163.com [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Li, E-mail: liulee@cpu.edu.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China); Liu, Xiaodong, E-mail: xdliu@cpu.edu.cn [Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009 (China)

2013-02-01

Accumulating evidences have showed that gatifloxacin causes dysglycemia in both diabetic and non-diabetic patients. Our preliminary study demonstrated that gatifloxacin stimulated glucagon-like peptide 1 (GLP-1) secretion from intestinal cells. The aim of the study was to investigate the association between gatifloxacin-stimulated GLP-1 release and dysglycemia in both normal and streptozotocin-induced diabetic rats and explore the possible mechanisms. Oral administration of gatifloxacin (100 mg/kg/day and 200 mg/kg/day) for 3 and 12 days led to marked elevation of GLP-1 levels, accompanied by significant decrease in insulin levels and increase in plasma glucose. Similar results were found in normal rats treated with 3-day gatifloxacin. Gatifloxacin-stimulated GLP-1 release was further confirmed in NCI-H716 cells, which was abolished by diazoxide, a K{sub ATP} channel opener. QT-PCR analysis showed that gatifloxacin also upregulated expression of proglucagon and prohormone convertase 3 mRNA. To clarify the contradiction on elevated GLP-1 without insulinotropic effect, effects of GLP-1 and gatifloxacin on insulin release were investigated using INS-1 cells. We found that short exposure (2 h) to GLP-1 stimulated insulin secretion and biosynthesis, whereas long exposure (24 h and 48 h) to high level of GLP-1 inhibited insulin secretion and biosynthesis. Moreover, we also confirmed gatifloxacin acutely stimulated insulin secretion while chronically inhibited insulin biosynthesis. All the results gave an inference that gatifloxacin stimulated over-secretion of GLP-1, in turn, high levels of GLP-1 and gatifloxacin synergistically impaired insulin release, worsening hyperglycemia. -- Highlights: ► Gatifloxacin induced hyperglycemia both in diabetic rats and normal rats. ► Gatifloxacin enhanced GLP-1 secretion but inhibited insulin secretion in rats. ► Long-term exposure to high GLP-1 inhibited insulin secretion and biosynthesis. ► GLP-1 over-secretion may be

Combined contributions of over-secreted glucagon-like peptide 1 and suppressed insulin secretion to hyperglycemia induced by gatifloxacin in rats

International Nuclear Information System (INIS)

Yu, Yunli; Wang, Xinting; Liu, Can; Yao, Dan; Hu, Mengyue; Li, Jia; Hu, Nan; Liu, Li; Liu, Xiaodong

2013-01-01

Accumulating evidences have showed that gatifloxacin causes dysglycemia in both diabetic and non-diabetic patients. Our preliminary study demonstrated that gatifloxacin stimulated glucagon-like peptide 1 (GLP-1) secretion from intestinal cells. The aim of the study was to investigate the association between gatifloxacin-stimulated GLP-1 release and dysglycemia in both normal and streptozotocin-induced diabetic rats and explore the possible mechanisms. Oral administration of gatifloxacin (100 mg/kg/day and 200 mg/kg/day) for 3 and 12 days led to marked elevation of GLP-1 levels, accompanied by significant decrease in insulin levels and increase in plasma glucose. Similar results were found in normal rats treated with 3-day gatifloxacin. Gatifloxacin-stimulated GLP-1 release was further confirmed in NCI-H716 cells, which was abolished by diazoxide, a K ATP channel opener. QT-PCR analysis showed that gatifloxacin also upregulated expression of proglucagon and prohormone convertase 3 mRNA. To clarify the contradiction on elevated GLP-1 without insulinotropic effect, effects of GLP-1 and gatifloxacin on insulin release were investigated using INS-1 cells. We found that short exposure (2 h) to GLP-1 stimulated insulin secretion and biosynthesis, whereas long exposure (24 h and 48 h) to high level of GLP-1 inhibited insulin secretion and biosynthesis. Moreover, we also confirmed gatifloxacin acutely stimulated insulin secretion while chronically inhibited insulin biosynthesis. All the results gave an inference that gatifloxacin stimulated over-secretion of GLP-1, in turn, high levels of GLP-1 and gatifloxacin synergistically impaired insulin release, worsening hyperglycemia. -- Highlights: ► Gatifloxacin induced hyperglycemia both in diabetic rats and normal rats. ► Gatifloxacin enhanced GLP-1 secretion but inhibited insulin secretion in rats. ► Long-term exposure to high GLP-1 inhibited insulin secretion and biosynthesis. ► GLP-1 over-secretion may be involved in

Shigella IpaD has a dual role: signal transduction from the type III secretion system needle tip and intracellular secretion regulation.

Science.gov (United States)

Roehrich, A Dorothea; Guillossou, Enora; Blocker, Ariel J; Martinez-Argudo, Isabel

2013-02-01

Type III secretion systems (T3SSs) are protein injection devices essential for the interaction of many Gram-negative bacteria with eukaryotic cells. While Shigella assembles its T3SS when the environmental conditions are appropriate for invasion, secretion is only activated after physical contact with a host cell. First, the translocators are secreted to form a pore in the host cell membrane, followed by effectors which manipulate the host cell. Secretion activation is tightly controlled by conserved T3SS components: the needle tip proteins IpaD and IpaB, the needle itself and the intracellular gatekeeper protein MxiC. To further characterize the role of IpaD during activation, we combined random mutagenesis with a genetic screen to identify ipaD mutant strains unable to respond to host cell contact. Class II mutants have an overall defect in secretion induction. They map to IpaD's C-terminal helix and likely affect activation signal generation or transmission. The Class I mutant secretes translocators prematurely and is specifically defective in IpaD secretion upon activation. A phenotypically equivalent mutant was found in mxiC. We show that IpaD and MxiC act in the same intracellular pathway. In summary, we demonstrate that IpaD has a dual role and acts at two distinct locations during secretion activation. © 2013 Blackwell Publishing Ltd.

Histaminergic regulation of prolactin secretion

DEFF Research Database (Denmark)

Knigge, U P

1990-01-01

Histamine (HA), which acts as a neurotransmitter in the central nervous system, participates in the neuroendocrine regulation of prolactin (PRL) secretion. HA has a predominant stimulatory effect which is mediated via H2-receptors following central administration and via H1-receptors following...... systemic infusion of the amine. In addition, HA seems to exert a minor inhibitory effect on PRL secretion, an effect unmasked only during blockade of the receptor mediating the stimulatory effect. Following central administration the inhibitory effect is mediated via H1-receptors, while following systemic...... administration this effect is mediated via H2-receptors. In accordance with these findings, the H2-receptor antagonist cimetidine (CIM) has an inhibitory (following central administration) or stimulatory (following systemic administration) effect on PRL secretion. However, high doses of CIM possess an additional...

An unexpected knock on Corrigan's secret door.

Science.gov (United States)

Woywodt, Alexander

2010-10-01

Corrigan's secret door describes a metaphorical escape route for busy physicians. The term was derived from the successful and exceptionally busy professional life of Irish physician Dominic John Corrigan (1802-80). It is claimed that Corrigan's outpatient clinic was so busy that he required a secret door in his consulting rooms to escape from the ever-growing queue of eager patients. The origins of this charming story are unknown, and the door may have never existed. However, at present, Corrigan's secret door is often quoted when busy physicians have their own little ways in surviving a stressful professional life. Generations of British-trained doctors have grown up with Corrigan's secret door, as it was featured in the introduction of the Oxford Handbook of Clinical Medicine. Accordingly, trainees as well as more senior doctors are often reminded that having a 'secret door' is vital in surviving in the medical profession. My own escape is through classical music and the violoncello, in particular. As the name implies, my own secret door is normally invisible to colleagues and patients. This little article is about a patient who found me out, and a reflection on the role of classical music and the cello in my professional life.

Salinity Alters the Polyisoprenoid Alcohol Content and Composition of Both Salt-Secreting and Non–Salt-Secreting Mangrove Seedlings

Directory of Open Access Journals (Sweden)

Mohammad Basyuni

2017-10-01

Full Text Available The effects of salinity on the polyisoprenoid alcohol content and composition of the salt-secreting mangrove species Avicennia marina and Sonneratia alba and the non–salt-secreting species Bruguiera gymnorrhiza and Kandelia obovata were studied. The seedlings of mangroves were grown for 5 months under 0% and 3% salt concentrations. The occurrence, content, and distribution of four mangrove seedlings were analyzed by two-dimensional thin layer chromatography. The structural groups of the polyprenols and dolichols in the leaves and roots were classified into two types (I and II. In type I, dolichols predominated over polyprenols (more than 90%, whereas in type II, the occurrence of both polyprenols and dolichols was observed. Polyprenols were not detected in the leaves of A. marina and B. gymnorrhiza under 0% salt (control, but were detected in small amounts in K. obovata leaves; however, significant amounts were found in the 3% salinity group. This finding in A. marina, B. gymnorrhiza, and K. obovata leaves implies a change to the structural group: under 0% salt concentrations, the groups are classified as type I, but become type II under 3% salt concentrations. The occurrence of ficaprenol (C50–55 was found only in the leaves of the non–salt-secreting species B. gymnorrhiza and K. obovata under 3% salinity and not in the salt-secreting species A. marina or S. alba. It is noteworthy that the polyisoprenoid type in the roots of the four species showed no change under salinity; the two salt-secreting species A. marina and S. alba contained type I under 0% and 3% salt concentrations. On the other hand, type II polyisoprenoids were identified in the non–salt-secreting species B. gymnorrhiza and K. obovata under 0% and 3% salinity conditions. This finding suggested that polyisoprenoids play a protective role against salinity in the mangrove leaves of both salt-secreting and non–salt-secreting species.

Secrets and Disclosures: How Young Children Handle Secrets

Science.gov (United States)

Anagnostaki, Lida; Wright, Michael J.; Papathanasiou, Athanasia

2013-01-01

The authors examined the influence of content and verbal cues on young children's understanding of secret information and of its disclosure. Participants were 209 5- and 6-year-old children in an experiment where a puppet, named Zinc, was the protagonist. Children were asked to whom Zinc would disclose a list of pieces of information, some of…

Regulation of atrial natriuretic peptide (ANP) secretion

International Nuclear Information System (INIS)

Ruskoaho, H.; Toth, M.; Lang, R.E.; Unger, Th.; Garten, D.

1986-01-01

To investigate the role of calcium, protein kinase C and adenylate cyclase in the ANP secretion, the secretory responses from isolated perfused rat hearts to a calcium channel activator, Bay k8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluomethylphenyl)-2-pyridine-5-carboxylate), the calcium ionophore (A23187), the phorbol ester (12-0-tetradecanoylphorbol-13-acetate, TPA), and to forskolin were studied. ANP in perfusate was measured by radioimmunoassay 10 min before and during the infusion (30 min) of various agents at 2 min intervals. A23187 (5.7 x 10 -7 ) induced a sharp increase, whereas TPA (0.15 - 1.6 x 10 -7 ) caused a slowly progressive increase in ANP secretion. 4a-phorbol-12,13-didecanoate, a non-active phorbol ester, had no effect on ANP secretion. Bay k8644 (4 x 10 -7 ) and forskolin (1 x 10 -6 ) alone caused small but sustained increase in ANP secretion. The combination of TPA with Bay k8644, forskolin or A23187 stimulated ANP secretion higher than the calculated additive value for each agent. Dibuturyl-cAMP (1.6 x 10 -4 ) pretreatment also enhanced TPA-induced ANP release. 8-Bromo-cGMP (1.3 x 10 -4 ) and sodium nitroprusside (9 x 10 -5 ) alone had no effect, but both attenuated the TPA-induced ANP secretion. The results suggest that atrial cardiocytes possess at least two different secretory pathways for ANP secretion, which are probably dependent on protein kinase C and cyclic AMP

Transporter-mediated biofuel secretion.

Science.gov (United States)

Doshi, Rupak; Nguyen, Tuan; Chang, Geoffrey

2013-05-07

Engineering microorganisms to produce biofuels is currently among the most promising strategies in renewable energy. However, harvesting these organisms for extracting biofuels is energy- and cost-intensive, limiting the commercial feasibility of large-scale production. Here, we demonstrate the use of a class of transport proteins of pharmacological interest to circumvent the need to harvest biomass during biofuel production. We show that membrane-embedded transporters, better known to efflux lipids and drugs, can be used to mediate the secretion of intracellularly synthesized model isoprenoid biofuel compounds to the extracellular milieu. Transporter-mediated biofuel secretion sustainably maintained an approximate three- to fivefold boost in biofuel production in our Escherichia coli test system. Because the transporters used in this study belong to the ubiquitous ATP-binding cassette protein family, we propose their use as "plug-and-play" biofuel-secreting systems in a variety of bacteria, cyanobacteria, diatoms, yeast, and algae used for biofuel production. This investigation showcases the potential of expressing desired membrane transport proteins in cell factories to achieve the export or import of substances of economic, environmental, or therapeutic importance.

A Common Structural Motif in the Binding of Virulence Factors to Bacterial Secretion Chaperones

International Nuclear Information System (INIS)

Lilic, M.; Vujanac, M.; Stebbins, C.

2006-01-01

Salmonella invasion protein A (SipA) is translocated into host cells by a type III secretion system (T3SS) and comprises two regions: one domain binds its cognate type III secretion chaperone, InvB, in the bacterium to facilitate translocation, while a second domain functions in the host cell, contributing to bacterial uptake by polymerizing actin. We present here the crystal structures of the SipA chaperone binding domain (CBD) alone and in complex with InvB. The SipA CBD is found to consist of a nonglobular polypeptide as well as a large globular domain, both of which are necessary for binding to InvB. We also identify a structural motif that may direct virulence factors to their cognate chaperones in a diverse range of pathogenic bacteria. Disruption of this structural motif leads to a destabilization of several chaperone-substrate complexes from different species, as well as an impairment of secretion in Salmonella

Kinetics of alpha-amylase secretion in Aspergillus oryzae

DEFF Research Database (Denmark)

Henriksen, Anne Laurence Santerre; Carlsen, Morten; Bang de, H.

1999-01-01

-chase experiments were carried out to investigate the alpha-amylase secretion kinetics in A. oryzae. No unglycosylated alpha-amylase was detected neither intracellularly nor extracellularly demonstrating that glycosylation was not the rate controlling step in the secretory pathway. The pulse chase experiments...... indicated that there are two pools of intracellular alpha-amylase: a fast secreted and a slow secreted. The secretion of those two pools were described with a kinetic model, which was fitted to the pulse chase experiments. (C) 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 65: 76-82, 1999....

Bile Formation and Secretion

Science.gov (United States)

Boyer, James L.

2014-01-01

Bile is a unique and vital aqueous secretion of the liver that is formed by the hepatocyte and modified down stream by absorptive and secretory properties of the bile duct epithelium. Approximately 5% of bile consists of organic and inorganic solutes of considerable complexity. The bile-secretory unit consists of a canalicular network which is formed by the apical membrane of adjacent hepatocytes and sealed by tight junctions. The bile canaliculi (~1 μm in diameter) conduct the flow of bile countercurrent to the direction of portal blood flow and connect with the canal of Hering and bile ducts which progressively increase in diameter and complexity prior to the entry of bile into the gallbladder, common bile duct, and intestine. Canalicular bile secretion is determined by both bile salt-dependent and independent transport systems which are localized at the apical membrane of the hepatocyte and largely consist of a series of adenosine triphosphate-binding cassette transport proteins that function as export pumps for bile salts and other organic solutes. These transporters create osmotic gradients within the bile canalicular lumen that provide the driving force for movement of fluid into the lumen via aquaporins. Species vary with respect to the relative amounts of bile salt-dependent and independent canalicular flow and cholangiocyte secretion which is highly regulated by hormones, second messengers, and signal transduction pathways. Most determinants of bile secretion are now characterized at the molecular level in animal models and in man. Genetic mutations serve to illuminate many of their functions. PMID:23897680

Threshold quantum secret sharing based on single qubit

Science.gov (United States)

Lu, Changbin; Miao, Fuyou; Meng, Keju; Yu, Yue

2018-03-01

Based on unitary phase shift operation on single qubit in association with Shamir's ( t, n) secret sharing, a ( t, n) threshold quantum secret sharing scheme (or ( t, n)-QSS) is proposed to share both classical information and quantum states. The scheme uses decoy photons to prevent eavesdropping and employs the secret in Shamir's scheme as the private value to guarantee the correctness of secret reconstruction. Analyses show it is resistant to typical intercept-and-resend attack, entangle-and-measure attack and participant attacks such as entanglement swapping attack. Moreover, it is easier to realize in physic and more practical in applications when compared with related ones. By the method in our scheme, new ( t, n)-QSS schemes can be easily constructed using other classical ( t, n) secret sharing.

Ionizing radiation in secret services' conspirative actions

Energy Technology Data Exchange (ETDEWEB)

Vogel, H. [Asklepios Klinik St. Georg, Roentgenabteilung, Lohmuehlenstrasse 5, 20099 Hamburg (Germany)], E-mail: Hermann.vogel@ak-stgeorg.lbk-hh.de; Lotz, P.; Vogel, B. [Asklepios Klinik St. Georg, Roentgenabteilung, Lohmuehlenstrasse 5, 20099 Hamburg (Germany)

2007-08-15

Introduction: The death of Litvinenko has been reported by the media. It has raised the question whether this case had been unique. The fall of the wall has allowed a glimpse in the planning and comporting of a secret service. Material and method: Documents of the secret service of the former German democratic republic (GDR), books of defectors, and media reports about secret service actions with radiating substances have been analyzed. Results: Since decades, secret services have been using radioactive nuclides and radiation for their tasks. Several killings with radiation have been reported. A complicated logistic had been developed. Conclusion: Only singular cases of the employment of radiating substances have become known. It is probable that the majority rests unknown. Government support seems necessary in secret services' conspirative actions with radiating substance.

Weegee’s City Secrets

OpenAIRE

TRACHTENBERG, Alan

2011-01-01

En tant que photographe indépendant de meurtres, d’accidents, d’incendies, mais aussi de moments de loisirs dans la ville — de scènes de violence et de plaisir — Weegee travaillait essentiellement la nuit et utilisait un flash puissant associé à son appareil-photo de presse. Ses « secrets pour réaliser des photographies avec un flash » consistent à donner des conseils pratiques et techniques pour débutants. Mais au cœur de la rhétorique de ses « secrets » se trouvent des réflexions subtiles e...

Identification and characterization of a type III secretion-associated chaperone in the type III secretion system 1 of Vibrio parahaemolyticus.

Science.gov (United States)

Akeda, Yukihiro; Okayama, Kanna; Kimura, Tomomi; Dryselius, Rikard; Kodama, Toshio; Oishi, Kazunori; Iida, Tetsuya; Honda, Takeshi

2009-07-01

Vibrio parahaemolyticus causes human gastroenteritis. Genomic sequencing of this organism has revealed that it has two sets of type III secretion systems, T3SS1 and T3SS2, both of which are important for its pathogenicity. However, the mechanism of protein secretion via T3SSs is unknown. A characteristic of many effectors is that they require specific chaperones for efficient delivery via T3SSs; however, no chaperone has been experimentally identified in the T3SSs of V. parahaemolyticus. In this study, we identified candidate T3SS1-associated chaperones from genomic sequence data and examined their roles in effector secretion/translocation and binding to their cognate substrates. From these experiments, we concluded that there is a T3S-associated chaperone, VecA, for a cytotoxic T3SS1-dependent effector, VepA. Further analysis using pulldown and secretion assays characterized the chaperone-binding domain encompassing the first 30-100 amino acids and an amino terminal secretion signal encompassing the first 5-20 amino acids on VepA. These findings will provide a strategy to clarify how the T3SS1 of V. parahaemolyticus secretes its specific effectors.

Impaired insulin secretion in the spontaneous diabetes rats.

Science.gov (United States)

Kimura, K; Toyota, T; Kakizaki, M; Kudo, M; Takebe, K; Goto, Y

1982-08-01

Dynamics of insulin and glucagon secretion were investigated by using a new model of spontaneous diabetes rats produced by the repetition of selective breeding in our laboratories. The perfusion experiments of the pancreas showed that the early phase of insulin secretion to continuous stimulation with glucose was specifically impaired, although the response of the early phase to arginine was preserved. The glucose-induced insulin secretion in the nineth generation (F8) which had a more remarkably impaired glucose tolerance was more reduced than in the sixth generation (F5). No significant difference of glucagon secretion in response to arginine or norepinephrine was noted between the diabetes rats and control ones. The present data indicate that the defective insulin secretion is a primary derangement in a diabetic state of the spontaneous diabetes rat. This defect in the early phase of glucose-induced insulin secretion suggests the specific impairment of the recognition of glucose by the pancreatic beta-cells. The spontaneous diabetes rats are very useful as a model of disease for investigating pathophysiology of non-insulin dependent diabetes mellitus.

Bucarest, Strictement Secret

Directory of Open Access Journals (Sweden)

Ionela Mihai

2010-07-01

Full Text Available L’émission Bucarest, strictement secret représente un documentaire organisésous la forme d’une série télé, qui dépeint le Bucarest à partir de deux perspectives: de l’histoire, de la conte et du lieu. La valeur d’une cité réside dans l’existence d’une mystique, d’un romantisme abscons, à part et des caractères empruntés de drames de Shakespeare, mystérieux, serrés d’angoisse et des secrets qui assombrissent leur existence. Par conséquence, le rôle du metteur en scène est de dévoiler leur vraie identité et de remettre en place, autant que possible, la vérité.

"The Secret Garden": A Literary Journey.

Science.gov (United States)

Jordan, Anne Devereaux

1998-01-01

Outlines the life of Frances Hodgson Burnett, author of "The Secret Garden." Argues that it not only tells an enthralling tale, but takes readers on a journey through the history of English literature. Discusses the gothic tradition and romanticism of "The Secret Garden." Lists classic elements in the book and offers five ideas…

Dig It! The Secrets of Soil

Science.gov (United States)

It! The Secrets of Soil Come and Explore! Discover the amazing world of soils with images and information from the Dig It! The Secrets of Soil exhibit from the Smithsonian's National Museum of Natural and new web content will be added over the coming months including a new soil blog. New Interactives

Effect of zinc on nectar secretion of Hibiscus rosa -sinensis L.

Science.gov (United States)

Sawidis, Thomas; Papadopoulou, Alexandra; Voulgaropoulou, Maria

2014-05-01

Zinc toxicity in secretory cells caused a range of effects, mainly depending on metal concentration. Low concentrations activated nectary function increasing nectar secretion but secretion was greatly inhibited or stopped entirely by ongoing concentration. Water loss rate of zinc treated flower parts was significantly reduced whereas green sepals were dehydrated more rapidly in comparison to colored petals. The content of zinc, calcium, magnesium and manganese increased mainly in sepals under excess of zinc, but in the secreted nectar this metal was not evident. Morphological changes were observed in mucilage cells concerning the mucilage structure and appearance. The parenchymatic, subglandular cells displayed an early vacuolarization and cytoplasm condensation. Secretory hairs appeared to be thinner, the apical cell folded inwards and plasmolytic shrinkage became severe in all cells. The waxy cuticula showed an increased electron density. A plasmalemma detachment from the external cell walls was observed creating a gap between cell wall and plasmalemma. ER cisterns of all treated nectary hairs dominated the cytoplasm and electron dense deposits were seen within its profiles. A great number of other organelles were also present, showing electron dense deposits in their membranes as well. The vacuome was drastically reduced in all cells, except in the subglandular ones and electron dense membrane remnants were observed.

Intracellular mediators of potassium-induced aldosterone secretion

International Nuclear Information System (INIS)

Ganguly, A.; Chiou, S.; Davis, J.S.

1990-01-01

We have investigated the intracellular messengers of potassium in eliciting aldosterone secretion in calf adrenal glomerulosa cells since there were unresolved issues relating to the role of phosphoinositides, cAMP and protein kinases. We observed no evidence of hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) in 3 H-inositol labeled alf adrenal cells or increase of cAMP in response to potassium. Addition of calcium channel blocker, nitrendipine after stimulating adrenal glomerulosa cells with potassium, markedly inhibited aldosterone secretion. A calmodulin inhibitor (W-7) produced greater reduction of aldosterone secretion than an inhibitor of protein kinase C (H-7). These results suggest that a rise in cytosolic free calcium concentration through voltage-dependent calcium channel and calmodulin are the critical determinants of aldosterone secretion stimulated by potassium

Apparent inhibition of β-fructosidase secretion by tunicamycin may be explained by breakdown of the unglycosylated protein during secretion

International Nuclear Information System (INIS)

Faye, L.; Chrispeels, M.J.

1989-01-01

Suspension-cultured carrot (Daucus carota) cells synthesize and secrete β-fructosidase, a glycoprotein with asparagine-linked glycans. Treatment of the cells with tunicamycin completely inhibits the apparent secretion of β-fructosidase as measured by the accumulation of the 35 S-labelled protein in the cell wall or the culture medium. In the past, such a result has been interpreted as an inhibition of secretion by tunicamycin, but we suggest another explanation based on the following results. In the presence of tunicamycin, unglycosylated β-fructosidase is synthesized and is associated with an endoplasmic-reticulum-rich microsomal fraction. Pulse-chase experiments show that the unglycosylated β-fructosidase does not remain in the cells and appears to be secreted in the same way as glycosylated β-fructosidase; however, no radioactive, unglycosylated β-fructosidase accumulates extracellularly (cell wall or medium). Protoplasts obtained from carrot cells secrete β-fructosidase protein and activity, and treatment of the protoplasts with tunicamycin results in the synthesis of unglycosylated β-fructosidase. In the presence of tunicamycin, there is no accumulation of β-fructosidase activity or unglycosylated β-fructosidase polypeptide in the protoplast incubation medium. These results are consistent with the interpretation that the glycans of β-fructosidase are necessary for its stability, and that in these suspension-cultured cells, the unglycosylated enzyme is degraded during the last stage(s) of secretion, or immediately after its arrival in the wall

A new potential secretion pathway for recombinant proteins in Bacillus subtilis.

Science.gov (United States)

Wang, Guangqiang; Xia, Yongjun; Gu, Zhennan; Zhang, Hao; Chen, Yong Q; Chen, Haiqin; Ai, Lianzhong; Chen, Wei

2015-11-10

Secretion of cytoplasmic expressed proteins into growth media has significant advantages. Due to the lack of an outer membrane, Bacillus subtilis is considered as a desirable 'cell factory' for the secretion of recombinant proteins. However, bottlenecks in the classical pathway for the secretion of recombinant proteins limit its use on a wide scale. In this study, we attempted to use four typical non-classically secreted proteins as signals to export three recombinant model proteins to the culture medium. All four non-classically secreted proteins can direct the export of the intrinsically disordered nucleoskeletal-like protein (Nsp). Two of them can guide the secretion of alkaline phosphatase (PhoA). One can lead the secretion of the thermostable β-galactosidase BgaB, which cannot be secreted with the aid of typical Sec-dependent signal peptides. Our results show that the non-classically secreted proteins lead the recombinant proteins to the culture medium, and thus non-classical protein secretion pathways can be exploited as a novel secretion pathway for recombinant proteins.

A translocator-specific export signal establishes the translocator-effector secretion hierarchy that is important for type III secretion system function

Science.gov (United States)

Tomalka, Amanda G.; Stopford, Charles M.; Lee, Pei-Chung; Rietsch, Arne

2012-01-01

Summary Type III secretion systems are used by many Gram-negative pathogens to directly deliver effector proteins into the cytoplasm of host cells. To accomplish this, bacteria secrete translocator proteins that form a pore in the host-cell membrane through which the effector proteins are then introduced into the host cell. Evidence from multiple systems indicates that the pore-forming translocator proteins are exported before effectors, but how this secretion hierarchy is established is unclear. Here we used the P. aeruginosa translocator protein PopD as a model to identify its export signals. The amino-terminal secretion signal and chaperone, PcrH, are required for export under all conditions. Two novel signals in PopD, one proximal to the chaperone-binding site and one at the very C-terminus of the protein, are required for export of PopD before effector proteins. These novel export signals establish the translocator-effector secretion hierarchy, which in turn, is critical for the delivery of effectors into host cells. PMID:23121689

Expressed prostatic secretion biomarkers improve stratification of NCCN active surveillance candidates: performance of secretion capacity and TMPRSS2:ERG models.

Science.gov (United States)

Whelan, Christopher; Kawachi, Mark; Smith, David D; Linehan, Jennifer; Babilonia, Gail; Mejia, Rosa; Wilson, Timothy; Smith, Steven S

2014-01-01

Active surveillance is a viable patient option for prostate cancer provided that a clinical determination of low risk and presumably organ confined disease can be made. To standardize risk stratification schemes the NCCN (National Comprehensive Cancer Network®) provides guidelines for the active surveillance option. We determined the effectiveness of expressed prostatic secretion biomarkers for detecting occult risk factors in NCCN active surveillance candidates. Expressed prostatic secretion specimens were obtained before robot-assisted radical prostatectomy. Secretion capacity biomarkers, including total RNA and expressed prostatic secretion specimen volume, were measured by standard techniques. RNA expression biomarkers, including TXNRD1 mRNA, prostate specific antigen mRNA, TMPRSS2:ERG fusion mRNA and PCA3 mRNA, were measured by quantitative reverse-transcription polymerase chain reaction. Of the 528 patients from whom expressed prostatic secretions were collected 216 were eligible for active surveillance under NCCN guidelines. Variable selection on logistic regression identified 2 models, including one featuring types III and VI TMPRSS2:ERG variants, and one featuring 2 secretion capacity biomarkers. Of the 2 high performing models the secretion capacity model was most effective for detecting cases in this group that were up-staged or up-staged plus upgraded. It decreased the risk of up-staging in patients with a negative test almost eightfold and decreased the risk of up-staging plus upgrading about fivefold while doubling the prevalence of up-staging in the positive test group. Noninvasive expressed prostatic secretion testing may improve patient acceptance of active surveillance by dramatically reducing the presence of occult risk factors among those eligible for active surveillance under NCCN guidelines. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Standpoints and protection of business secrets

Directory of Open Access Journals (Sweden)

Brane Bertoncelj

2001-06-01

Full Text Available The human impact on an information system where data bases, containing business secretes, are stored is one of the most unreliable and unforeseeable factors. For this reason, it must not be underestimated. The results of this study indicate a correlation between behavioural intention and protection of business secretes. There is a statistically significant correlation between behavioural intention and behavioural supervision. This means that an increased level of perceived supervision over one's own behaviour is related to behavioural intention. A great majority of participants would not divulge a business secret due to internal moral factors, i.e., they possess the appropriate capabilities to determine the advantages of social moral values over personal values.

Impact of Mesenchymal Stem Cell secreted PAI-1 on colon cancer cell migration and proliferation

Energy Technology Data Exchange (ETDEWEB)

Hogan, Niamh M. [Discipline of Surgery, School of Medicine, National University of Ireland, Galway (Ireland); Joyce, Myles R. [Department of Colorectal Surgery, University College Hospital, Galway (Ireland); Murphy, J. Mary; Barry, Frank P.; O’Brien, Timothy [Regenerative Medicine Institute, National University of Ireland, Galway (Ireland); Kerin, Michael J. [Discipline of Surgery, School of Medicine, National University of Ireland, Galway (Ireland); Dwyer, Roisin M., E-mail: roisin.dwyer@nuigalway.ie [Discipline of Surgery, School of Medicine, National University of Ireland, Galway (Ireland)

2013-06-14

Highlights: •MSCs were directly co-cultured with colorectal cancer (CRC) cells on 3D scaffolds. •MSCs influence CRC protein/gene expression, proliferation and migration. •We report a significant functional role of MSC-secreted PAI-1 in colon cancer. -- Abstract: Mesenchymal Stem Cells are known to engraft and integrate into the architecture of colorectal tumours, with little known regarding their fate following engraftment. This study aimed to investigate mediators of Mesenchymal Stem Cell (MSC) and colon cancer cell (CCC) interactions. Mesenchymal Stem Cells and colon cancer cells (HT29 and HCT-116) were cultured individually or in co-culture on 3-dimensional scaffolds. Conditioned media containing all secreted factors was harvested at day 1, 3 and 7. Chemokine secretion and expression were analyzed by Chemi-array, ELISA (Macrophage migration inhibitory factor (MIF), plasminogen activator inhibitor type 1 (PAI-1)) and RQ-PCR. Colon cancer cell migration and proliferation in response to recombinant PAI-1, MSCs and MSCs + antibody to PAI-1 was analyzed using Transwell inserts and an MTS proliferation assay respectively. Chemi-array revealed secretion of a wide range of factors by each cell population, including PAI-1and MIF. ELISA analysis revealed Mesenchymal Stem Cells to secrete the highest levels of PAI-1 (MSC mean 10.6 ng/mL, CCC mean 1.01 ng/mL), while colon cancer cells were the principal source of MIF. MSC-secreted PAI-1 stimulated significant migration of both CCC lines, with an antibody to the chemokine shown to block this effect (67–88% blocking,). A cell-line dependant effect on CCC proliferation was shown for Mesenchymal Stem Cell-secreted PAI-1 with HCT-116 cells showing decreased proliferation at all concentrations, and HT29 cells showing increased proliferation in the presence of higher PAI-1 levels. This is the first study to identify PAI-1 as an important mediator of Mesenchymal Stem Cell/colon cancer cell interactions and highlights the

Impact of Mesenchymal Stem Cell secreted PAI-1 on colon cancer cell migration and proliferation

International Nuclear Information System (INIS)

Hogan, Niamh M.; Joyce, Myles R.; Murphy, J. Mary; Barry, Frank P.; O’Brien, Timothy; Kerin, Michael J.; Dwyer, Roisin M.

2013-01-01

Highlights: •MSCs were directly co-cultured with colorectal cancer (CRC) cells on 3D scaffolds. •MSCs influence CRC protein/gene expression, proliferation and migration. •We report a significant functional role of MSC-secreted PAI-1 in colon cancer. -- Abstract: Mesenchymal Stem Cells are known to engraft and integrate into the architecture of colorectal tumours, with little known regarding their fate following engraftment. This study aimed to investigate mediators of Mesenchymal Stem Cell (MSC) and colon cancer cell (CCC) interactions. Mesenchymal Stem Cells and colon cancer cells (HT29 and HCT-116) were cultured individually or in co-culture on 3-dimensional scaffolds. Conditioned media containing all secreted factors was harvested at day 1, 3 and 7. Chemokine secretion and expression were analyzed by Chemi-array, ELISA (Macrophage migration inhibitory factor (MIF), plasminogen activator inhibitor type 1 (PAI-1)) and RQ-PCR. Colon cancer cell migration and proliferation in response to recombinant PAI-1, MSCs and MSCs + antibody to PAI-1 was analyzed using Transwell inserts and an MTS proliferation assay respectively. Chemi-array revealed secretion of a wide range of factors by each cell population, including PAI-1and MIF. ELISA analysis revealed Mesenchymal Stem Cells to secrete the highest levels of PAI-1 (MSC mean 10.6 ng/mL, CCC mean 1.01 ng/mL), while colon cancer cells were the principal source of MIF. MSC-secreted PAI-1 stimulated significant migration of both CCC lines, with an antibody to the chemokine shown to block this effect (67–88% blocking,). A cell-line dependant effect on CCC proliferation was shown for Mesenchymal Stem Cell-secreted PAI-1 with HCT-116 cells showing decreased proliferation at all concentrations, and HT29 cells showing increased proliferation in the presence of higher PAI-1 levels. This is the first study to identify PAI-1 as an important mediator of Mesenchymal Stem Cell/colon cancer cell interactions and highlights the

Quantum secret sharing protocol using modulated doubly entangled photons

International Nuclear Information System (INIS)

Chuan, Wang; Yong, Zhang

2009-01-01

In this paper, we propose a quantum secret sharing protocol utilizing polarization modulated doubly entangled photon pairs. The measurement devices are constructed. By modulating the polarizations of entangled photons, the boss could encode secret information on the initial state and share the photons with different members to realize the secret sharing process. This protocol shows the security against intercept-resend attack and dishonest member cheating. The generalized quantum secret sharing protocol is also discussed. (general)

Secret Places.

Science.gov (United States)

Ridolfi, Kerry

1997-01-01

Argues that children are as deep as the ocean, with secret places inside of them waiting to be opened. Notes that it is powerful for students to learn they can make sense of the world through words, and describes inviting them into poetry as they read poetry, create poetry packets, and write and revise poems. (SR)

Lipids in airway secretions

International Nuclear Information System (INIS)

Bhaskar, K.R.; DeFeudis O'Sullivan, D.; Opaskar-Hincman, H.; Reid, L.M.

1987-01-01

Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO 2 , (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors 14 C acetate and 14 C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway. (author)

A thyrotropin‑secreting macroadenoma with positive growth ...

African Journals Online (AJOL)

A thyrotropin‑secreting macroadenoma with positive growth hormone and prolactin immunostaining: A case report and literature review. ... thyroid hormone receptor resistance syndrome. Key words: Inappropriate thyroid stimulating hormone, thyrotropin‑secreting pituitary adenoma, thyroid stimulating hormone adenoma ...

Tumor cell-macrophage interactions increase angiogenesis through secretion of EMMPRIN

Directory of Open Access Journals (Sweden)

Bat-Chen eAmit-Cohen

2013-07-01

Full Text Available Tumor macrophages are generally considered to be alternatively/M2 activated to induce secretion of pro-angiogenic factors such as VEGF and MMPs. EMMPRIN (CD147, basigin is overexpressed in many tumor types, and has been shown to induce fibroblasts and endothelial cell expression of MMPs and VEGF. We first show that tumor cell interactions with macrophages resulted in increased expression of EMMPRIN and induction of MMP-9 and VEGF. Human A498 renal carcinoma or MCF-7 breast carcinoma cell lines were co-cultured with the U937 monocytic-like cell line in the presence of TNFalpha (1 ng/ml. Membranal EMMPRIN expression was increased in the co-cultures (by 3-4 folds, p<0.01, as was the secretion of MMP-9 and VEGF (by 2-5 folds for both MMP-9 and VEGF, p<0.01, relative to the single cultures with TNFalpha. Investigating the regulatory mechanisms, we show that EMMPRIN was post-translationally regulated by miR-146a, as no change was observed in the tumoral expression of EMMPRIN mRNA during co-culture, expression of miR-146a was increased and its neutralization by its antagomir inhibited EMMPRIN expression. The secretion of EMMPRIN was also enhanced (by 2-3 folds, p<0.05, only in the A498 co-culture via shedding off of the membranal protein by a serine protease that is yet to be identified, as demonstrated by the use of wide range protease inhibitors. Finally, soluble EMMPRIN enhanced monocytic secretion of MMP-9 and VEGF, as inhibition of its expression levels by neutralizing anti-EMMPRIN or siRNA in the tumor cells lead to subsequent decreased induction of these two pro-angiogenic proteins. These results reveal a mechanism whereby tumor cell-macrophage interactions promote angiogenesis via an EMMPRIN-mediated pathway.

Identification of genes encoding the type IX secretion system and secreted proteins in Flavobacterium columnare IA-S-4

Science.gov (United States)

Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes...

VIP secreting tumours in infancy

International Nuclear Information System (INIS)

Davies, R.P.; Slavotinek, J.P.; Dorney, S.F.A.

1990-01-01

Vasoactive intestinal polypeptide (VIP) secreting neural crest tumours are an uncommon but important treatable cause of intractable childhood diarrhoea. The radiological appearances of two cases are presented with a review of radiological findings in childhood VIP secreting neural crest tumours. Twenty eight cases of childhood VIP secreting neural crest tumours were reviewed. Nineteen (68%) were ganglioneuroblastomas and nine (32%) were ganglioneuromas. The majority of tumours (66%) were in a paravertebral location in the abdomen indicating that a search for such a tumour should be initiated at this site. Eighteen of the twenty eight cases reviewed discussed relevant radiological investigations. Calcification was detected in 50% of abdominal radiographs. Gut dilatation was often a prominent feature. A mass was detected in 5 of 5 cases where ultrasound findings were reported, and seven of seven cases with CT findings reported. Prior to the availability of CT and ultrasound the most useful investigation was IVU which demonstrated evidence of a mass in 5 of 9 cases. The presence of paravertebral calcification and gut dilatation on the plain radiograph of a child with intractable diarrhoea suggests the presence of a VIP secreting neural crest tumour. If an abdominal tumour is not found in the appropriate clinical setting and VIP levels are elevated, a widespread search of the paravertebral region is indicated. (orig.)

Autophagy-dependent secretion: contribution to tumor progression

Directory of Open Access Journals (Sweden)

Tom Keulers

2016-11-01

Full Text Available Autophagy is best known as a lysosomal degradation and recycling pathway to maintain cellular homeostasis. During autophagy, cytoplasmic content is recognized and packed in autophagic vacuoles, or autophagosomes, and targeted for degradation. However, during the last years, it has become evident that the role of autophagy is not restricted to degradation alone but also mediates unconventional forms of secretion. Furthermore, cells with defects in autophagy apparently are able to reroute their cargo, like mitochondria, to the extracellular environment; effects that contribute to an array of pathologies. In this review we discuss the current knowledge of the physiological roles of autophagy-dependent secretion, i.e. the effect on inflammation and insulin/ hormone secretion. Finally, we focus on the effects of autophagy-dependent secretion on the tumour microenvironment and tumour progression. The autophagy mediated secreted factors may stimulate cellular proliferation via auto- and paracrine signaling. The autophagy mediated release of immune modulating proteins change the immunosuppresive tumor microenvironment and may promote an invasive phenotype. These effects may be either direct or indirect through facilitating formation of the mobilized vesicle, aid in anterograde trafficking or alterations in homeostasis and/or autonomous cell signaling.

Enhanced secretion of natto phytase by Bacillus subtilis.

Science.gov (United States)

Tsuji, Shogo; Tanaka, Kosei; Takenaka, Shinji; Yoshida, Ken-ichi

2015-01-01

Phytases comprise a group of phosphatases that trim inorganic phosphates from phytic acid (IP6). In this study, we aimed to achieve the efficient secretion of phytase by Bacillus subtilis. B. subtilis laboratory standard strain 168 and its derivatives exhibit no phytase activity, whereas a natto starter secretes phytase actively. The natto phytase gene was cloned into strain RIK1285, a protease-defective derivative of 168, to construct a random library of its N-terminal fusions with 173 different signal peptides (SPs) identified in the 168 genome. The library was screened to assess the efficiency of phytase secretion based on clear zones around colonies on plates, which appeared when IP6 was hydrolyzed. The pbp SP enhanced the secretion of the natto phytase most efficiently, i.e. twice that of the original SP. Thus, the secreted natto phytase was purified and found to remove up to 3 phosphates from IP6.

Applying secret sharing for HIS backup exchange.

Science.gov (United States)

Kuroda, Tomohiro; Kimura, Eizen; Matsumura, Yasushi; Yamashita, Yoshinori; Hiramatsu, Haruhiko; Kume, Naoto; Sato, Atsushi

2013-01-01

To secure business continuity is indispensable for hospitals to fulfill its social responsibility under disasters. Although to back up the data of the hospital information system (HIS) at multiple remote sites is a key strategy of business continuity plan (BCP), the requirements to treat privacy sensitive data jack up the cost for the backup. The secret sharing is a method to split an original secret message up so that each individual piece is meaningless, but putting sufficient number of pieces together to reveal the original message. The secret sharing method eases us to exchange HIS backups between multiple hospitals. This paper evaluated the feasibility of the commercial secret sharing solution for HIS backup through several simulations. The result shows that the commercial solution is feasible to realize reasonable HIS backup exchange platform when template of contract between participating hospitals is ready.

Iodine-131 saliva secretion in ablation treatment for thyroid cancer patients

International Nuclear Information System (INIS)

Nascimento, Ana C.H.; Brandao, Luis E.; Candeiro, Ricardo E.; Rebelo, Ana M.O.; Corbo, Rossana; Dutra, Janaina

2008-01-01

In general, well-differentiated thyroid cancer treatment consists in Na 131 I administration following total or a near total thyroidectomy. The activity of a single administration in the majority of nuclear centers ranges from 1 to 4 GBq for residual thyroid tissue elimination and ranges from 4 to 8 GBq for residual thyroid tissue as well as metastases elimination. The high magnitude of 131 I activities administered for thyroid cancer treatment can lead to side effects, where salivary gland dysfunctions are the most common observed. In the absence of thyroid gland, secondary tissues - iodide specific uptake, mainly the salivary glands, rise at the element body retention process. In addition, among nuclear medicine professionals, there is no consensus about suitable restrictions that must be observed by the hospital released patient to avoid 131 I contamination by saliva. The aim of this study is to evaluate qualitatively the secretion of 131 I by salivary glands after the administration of the radionuclide to thyroid cancer patients for ablation purposes. Well-differentiated thyroid cancer patients from Clementino Fraga Filho University Hospital (HUCFF) of Federal University of Rio de Janeiro (UFRJ) followed-up in the present study are female, adult and without additional health diseases detected. After 131 I administration for ablation purposes, saliva samples were collected systematically and counting rate was assessed using a NaI(Tl) scintillator detector. As the study is at an early stage, the preliminary results concern the possibility of conducting an evaluation of 131 I secreted in saliva using the proposed protocol. It can be seen that many factors have potential to influence the behaviour of 1 31 I secretion in saliva, for example the use of Na 131 I in solution or in capsules. It was observed two standards that can be defined according to these variables. (author)

The Secret of Guided Missile Re-Entry,

Science.gov (United States)

1986-06-25

I RD-PAI169 598 THE SECRET OF GUIDED MISSILE RE-ENTRY(U) FOREIGN / I TECHNOLOGY DIV NRIGHT-PATTERSON RFB OH J CHEN ET AL. I 25 JUN 96 FTD-ID(RS)T...TECHNOLOGY DIVISION THE SECRET OF GUIDED MISSILE RE-ENTRY by Chen Jingzhong, An Sehua J L 0 7 ’:;85’ ’ 0 *Approved for public release; Distribution...unlimite t d. :. 86 7 034.. FTD- ID(RS)T-0459-86 HUMAN TRANSLATION FTD-ID(RS)T-0459-86 25 June 1986 MICROFICHE NR: F - - 0Q 9? THE SECRET OF GUIDED

Impaired Follistatin Secretion in Cirrhosis

DEFF Research Database (Denmark)

Rinnov, Anders Rasmussen; Plomgaard, Peter; Pedersen, Bente Klarlund

2016-01-01

compared to healthy control participants. DESIGN, SETTING, AND PARTICIPANTS: To experimentally increase the glucagon-insulin ratio (mimicking the hormonal effect of exercise), we infused glucagon/somatostatin (to inhibit insulin secretion) and compared the acute follistatin increase in eight male cirrhosis...... controls (27.6 ± 3.8 vs 34.5 ± 2.9%, respectively; P = .001). CONCLUSIONS: Patients with cirrhosis show impaired capacity to acutely secrete follistatin. The decrease in acute follistatin release may contribute to the loss of muscle mass in liver cirrhosis....

10 CFR 1016.34 - Accountability for Secret Restricted Data.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Accountability for Secret Restricted Data. 1016.34 Section... Information § 1016.34 Accountability for Secret Restricted Data. Each permittee possessing documents containing Secret Restricted Data shall establish a document accountability procedure and shall maintain...

Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

1996-01-01

with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means...

A catalogue of human secreted proteins and its implications

Directory of Open Access Journals (Sweden)

Shivakumar Keerthikumar

2016-11-01

Full Text Available Under both normal and pathological conditions, cells secrete variety of proteins through classical and non-classical secretory pathways into the extracellular space. Majority of these proteins represent pathophysiology of the cell from which it is secreted. Recently, though more than 92% of the protein coding genes has been mapped by human proteome map project, but number of those proteins that constitutes secretome of the cell still remains elusive. Secreted proteins or the secretome can be accessible in bodily fluids and hence are considered as potential biomarkers to discriminate between healthy and diseased individuals. In order to facilitate the biomarker discovery and to further aid clinicians and scientists working in these arenas, we have compiled and catalogued secreted proteins from the human proteome using integrated bioinformatics approach. In this study, nearly 14% of the human proteome is likely to be secreted through classical and non-classical secretory pathways. Out of which, ~38% of these secreted proteins were found in extracellular vesicles including exosomes and shedding microvesicles. Among these secreted proteins, 94% were detected in human bodily fluids including blood, plasma, serum, saliva, semen, tear and urine. We anticipate that this high confidence list of secreted proteins could serve as a compendium of candidate biomarkers. In addition, the catalogue may provide functional insights in understanding the molecular mechanisms involved in various physiological and pathophysiological conditions of the cell.

Affinity of antibody secreted by a single cell

International Nuclear Information System (INIS)

Doran, D.M.

1978-01-01

It was the intention of this research to measure the affinity of antibody secreted by a single cell, and to describe the spectrum of affinities displayed in response to antigenic stimulation. The single cell secreting specific antibody was isolated by means of the hemolytic plaque assay. The amount of antibody secreted by the cell was to be measured through the use of a solid phase radioimmunoassay. The affinity of the antibody would be estimated by comparing the diameter of the plaque, and the amount of antibody secreted, with a mathematical theory of the formation of a plaque in agar. As a test system, a solid phase radioimmunoassay was developed for human serum albumin using antibody coupled to Sephadex. A sensitivity of 1 nanogram was attained with this assay. A solid phase radioimmunoassay for mouse immunoglobulin M was developed, using antibody coupled to Sepharose. The sensitivity attained with this assay was only on the order of 10 micrograms. The mouse immunoglobulin M radioimmunoassay was not sensitive enough to measure the amount of antibody secreted by a single cell. From a theoretical equation, the relationship between antibody affinity, plaque diameter and antibody secretion rate was calculated for the experimental conditions used in this research. By assuming a constant antibody secretion rate, an effective binding constant for the antibody was estimated from the average plaque diameters. This effective binding constant was observed to increase during the immune response

Humidification and secretion volume in mechanically ventilated patients.

Science.gov (United States)

Solomita, Mario; Palmer, Lucy B; Daroowalla, Feroza; Liu, Jeffrey; Miller, Dori; LeBlanc, Deniese S; Smaldone, Gerald C

2009-10-01

To determine potential effects of humidification on the volume of airway secretions in mechanically ventilated patients. Water vapor delivery from devices providing non-heated-wire humidification, heated-wire humidification, and heat and moisture exchanger (HME) were quantified on the bench. Then, patients requiring 24-hour mechanical ventilation were exposed sequentially to each of these humidification devices, and secretions were removed and measured by suctioning every hour during the last 4 hours of the 24-hour study period. In vitro water vapor delivery was greater using non-heated-wire humidification, compared to heated-wire humidification and HME. In vivo, a total of 9 patients were studied. Secretion volume following humidification by non-heated-wire humidification was significantly greater than for heated-wire humidification and HME (P=.004). The volume of secretions appeared to be linked to humidification, as greater water vapor delivery measured in vitro was associated with greater secretion volume in vivo.

Type-IVC Secretion System: A Novel Subclass of Type IV Secretion System (T4SS) Common Existing in Gram-Positive Genus Streptococcus

Science.gov (United States)

Chen, Chen; Gao, George F.

2012-01-01

A growing number of pathogens are being found to possess specialized secretion systems which they use in various ways to subvert host defenses. Type IV secretion system (T4SS) is one of versatile secretion systems essential for the virulence and even survival of some bacteria species, and they enable the secretion of protein and DNA substrates across the cell envelope. T4SS was once believed to be present only in Gram-negative bacteria. In this study, we present evidence of a new subclass of T4SS, Type-IVC secretion system and indicate its common existence in the Gram-positive bacterial genus Streptococcus. We further identified that VirB1, VirB4, VirB6 and VirD4 are the minimal key components of this system. Using genome comparisons and evolutionary relationship analysis, we proposed that Type-IVC secretion system is movable via transposon factors and mediates the conjugative transfer of DNA, enhances bacterial pathogenicity, and could cause large-scale outbreaks of infections in humans. PMID:23056296

The semantics of secrecy: young children's classification of secret content.

Science.gov (United States)

Anagnostaki, Lida; Wright, Michael J; Bourchier-Sutton, Alison J

2010-01-01

The authors explored whether young children can distinguish potential secrets from nonsecrets by their content, as can older children, adolescents, and adults. Ninety children, 4, 5, and 6 years old, rated the secrecy of items from an adult-validated list of personal information about an age- and gender-appropriate puppet. Two factors of the children's data corresponded to the adult categories of nonsecrets and secrets, and a third factor corresponded to surprises. All ages rated surprises as significantly more secret than nonsecret items; however, the surprise items contained linguistic cues to secrecy. A tendency to rate nonsecrets as secret decreased with age, but only the 6-year-olds rated secrets other than surprises as significantly more secret than nonsecrets. Thus, children acquire the implicit rules defining secret content from a somewhat later age than that reported for the cognitive or behavioral capacities for secrecy.

The Smart Grid - A saucerful of secrets?

International Nuclear Information System (INIS)

Wissner, Matthias

2011-01-01

To many, a lot of secrets are at the bottom of the often-cited catchphrase 'Smart Grid'. This article gives an overview of the options that information and communication technology (ICT) offers for the restructuring and modernisation of the German power system, in particular with a view towards its development into a Smart Grid and thus tries to reveal these secrets. After a short outline on the development of ICT in terms of technology types and their availability, the further analysis highlights upcoming challenges in all parts of the power value chain and possible solutions for these challenges through the intensified usage of ICT applications. They are examined with regard to their effectiveness and efficiency in the fields of generation, transmission, distribution and supply. Finally, potential obstacles that may defer the introduction of ICT into the power system are shown. The analysis suggests that if certain hurdles are taken, the huge potential of ICT can create additional value in various fields of the whole power value chain. This ranges from increased energy efficiency and the more sophisticated integration of decentralised (renewable) energy plants to a higher security of supply and more efficient organisation of market processes. The results are true for the German power market but can in many areas also be transferred to other industrialised nations with liberalised power markets.

Single-Cell Detection of Secreted Aβ and sAPPα from Human IPSC-Derived Neurons and Astrocytes.

Science.gov (United States)

Liao, Mei-Chen; Muratore, Christina R; Gierahn, Todd M; Sullivan, Sarah E; Srikanth, Priya; De Jager, Philip L; Love, J Christopher; Young-Pearse, Tracy L

2016-02-03

Secreted factors play a central role in normal and pathological processes in every tissue in the body. The brain is composed of a highly complex milieu of different cell types and few methods exist that can identify which individual cells in a complex mixture are secreting specific analytes. By identifying which cells are responsible, we can better understand neural physiology and pathophysiology, more readily identify the underlying pathways responsible for analyte production, and ultimately use this information to guide the development of novel therapeutic strategies that target the cell types of relevance. We present here a method for detecting analytes secreted from single human induced pluripotent stem cell (iPSC)-derived neural cells and have applied the method to measure amyloid β (Aβ) and soluble amyloid precursor protein-alpha (sAPPα), analytes central to Alzheimer's disease pathogenesis. Through these studies, we have uncovered the dynamic range of secretion profiles of these analytes from single iPSC-derived neuronal and glial cells and have molecularly characterized subpopulations of these cells through immunostaining and gene expression analyses. In examining Aβ and sAPPα secretion from single cells, we were able to identify previously unappreciated complexities in the biology of APP cleavage that could not otherwise have been found by studying averaged responses over pools of cells. This technique can be readily adapted to the detection of other analytes secreted by neural cells, which would have the potential to open new perspectives into human CNS development and dysfunction. We have established a technology that, for the first time, detects secreted analytes from single human neurons and astrocytes. We examine secretion of the Alzheimer's disease-relevant factors amyloid β (Aβ) and soluble amyloid precursor protein-alpha (sAPPα) and present novel findings that could not have been observed without a single-cell analytical platform. First, we

Engineering signal peptides for enhanced protein secretion from Lactococcus lactis.

Science.gov (United States)

Ng, Daphne T W; Sarkar, Casim A

2013-01-01

Lactococcus lactis is an attractive vehicle for biotechnological production of proteins and clinical delivery of therapeutics. In many such applications using this host, it is desirable to maximize secretion of recombinant proteins into the extracellular space, which is typically achieved by using the native signal peptide from a major secreted lactococcal protein, Usp45. In order to further increase protein secretion from L. lactis, inherent limitations of the Usp45 signal peptide (Usp45sp) must be elucidated. Here, we performed extensive mutagenesis on Usp45sp to probe the effects of both the mRNA sequence (silent mutations) and the peptide sequence (amino acid substitutions) on secretion. We screened signal peptides based on their resulting secretion levels of Staphylococcus aureus nuclease and further evaluated them for secretion of Bacillus subtilis α-amylase. Silent mutations alone gave an increase of up to 16% in the secretion of α-amylase through a mechanism consistent with relaxed mRNA folding around the ribosome binding site and enhanced translation. Targeted amino acid mutagenesis in Usp45sp, combined with additional silent mutations from the best clone in the initial screen, yielded an increase of up to 51% in maximum secretion of α-amylase while maintaining secretion at lower induction levels. The best sequence from our screen preserves the tripartite structure of the native signal peptide but increases the positive charge of the n-region. Our study presents the first example of an engineered L. lactis signal peptide with a higher secretion yield than Usp45sp and, more generally, provides strategies for further enhancing protein secretion in bacterial hosts.

The problem of using trade secrets in economic relations

Directory of Open Access Journals (Sweden)

А. О. Олефір

2015-05-01

Full Text Available Problem setting. In a market economy and increased competition between enterprises become increasingly important concepts such as business information, trade secrets, know-how, confidential information, the information with restricted access. Given the fact that only one patent protection is unable to meet the needs of researchers, in addition to formal public protection and secured legal means we would like to pay attention at private legal measures, particular, the mode of trade secrets. Recent research and publications analysis. Different aspects of the protection of trade secrets were investigated by specialists such as G. Androschuk, J. Berzhye, I. Davydov, O. Davydyuk, D. Zadyhaylo, P. Kraynov, G. Nikiforov, S. Nikiforov, V. Rubanov, E. Solovyov, L. Hoffman, V. Chaplygin, A. Cherniavsky and others. However, at present there is a lack of comprehensive research of this legal phenomenon, equally useful for innovators and businesses that actively protect corporate security. Paper objective. This article is planned to determine the legal characteristics, structural elements and mechanisms by which the use of trade secrets in business have a positive impact on innovation development and corporate security entities. Paper main body. On the basis of requirements of Art. 505 Civil Code of Ukraine and art. 39 of the TRIPS Agreement we formulated commercial information signs under which it receives legal protection as an object of intellectual property: (1 privacy (real or potential in the sense that it is as a whole or in a precise combination of aggregate and its components are not generally known or available to persons in the circles that normally deal with such information; (2 commercial value (not purely industrial or industrial, due to its secrecy; this information is unknown to others, which is a commercial interest; (3 the lawful holder of the information provides active special measures (technical, organizational, legal to preserve secrecy

A Public Secret

DEFF Research Database (Denmark)

Bregnbæk, Susanne

2011-01-01

This article is based on anthropological fieldwork undertaken at two elite universities in Beijing. It addresses the paradoxical situation of the many instances of suicide among Chinese elite university students in Beijing, which constitute a public secret. The pressure of education weighs heavily...

An unexpected knock on Corrigan’s secret door

Science.gov (United States)

Woywodt, Alexander

2010-01-01

Corrigan’s secret door describes a metaphorical escape route for busy physicians. The term was derived from the successful and exceptionally busy professional life of Irish physician Dominic John Corrigan (1802–80). It is claimed that Corrigan’s outpatient clinic was so busy that he required a secret door in his consulting rooms to escape from the ever-growing queue of eager patients. The origins of this charming story are unknown, and the door may have never existed. However, at present, Corrigan’s secret door is often quoted when busy physicians have their own little ways in surviving a stressful professional life. Generations of British-trained doctors have grown up with Corrigan’s secret door, as it was featured in the introduction of the Oxford Handbook of Clinical Medicine. Accordingly, trainees as well as more senior doctors are often reminded that having a ‘secret door’ is vital in surviving in the medical profession. My own escape is through classical music and the violoncello, in particular. As the name implies, my own secret door is normally invisible to colleagues and patients. This little article is about a patient who found me out, and a reflection on the role of classical music and the cello in my professional life. PMID:25984078

Pathophysiology of glucagon secretion

International Nuclear Information System (INIS)

Boettger, J.; Pabst, H.W.

1980-01-01

Pathophysiology of glucagon secretion is reviewed in brief separating hyperglucagonemic from hypoclucagonemic states. Many questions concerning the role of glucagon in diabetes mellitus and in other diseases are still unresolved. The clucagon RIA is of clinical significance in a few diseases like glucagonoma, which may present without symptoms of the 'glucagonoma syndrome', the probably very rare hyperglucagonemia and some of the spontaneous hypoglycemias. Glucagon secretion may be evaluated by the determination of fasting immunoreactive glucagon (IRG) and by appropriate function tests as stimulation with i.v. arginine and suppression with oral glucose. However, the glucagon RIA at present is not a routine method, although commercial kits are available. Many pitfalls of radioimmunological glucagon determination still exist. (orig.) [de

The effect of imiquimod on taste bud calcium transients and transmitter secretion.

Science.gov (United States)

Huang, Anthony Y; Wu, Sandy Y

2016-11-01

Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell-cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste-evoked ATP secretion from mouse taste buds. Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca 2+ concentrations. These Ca 2 + responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca 2 + -ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca 2 + mobilization elicited by imiquimod was dependent on release from internal Ca 2 + stores. Moreover, combining studies of Ca 2 + imaging with cellular biosensors showed that imiquimod evoked secretion of 5-HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste-evoked ATP secretion. Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5-HT signalling. © 2016 The British Pharmacological Society.

Biliary and pancreatic secretions in abdominal irradiation

International Nuclear Information System (INIS)

Becciolini, A.; Cionini, L.; Cappellini, M.; Atzeni, G.

1979-01-01

The biliary and pancreatic secretions have been determined in patients given pelvic or para-aortic irradiation, with a dose of 50 Gy in the former group and between 36 and 40 Gy in the latter. A test meal containing polyethylene glycol (PEG) as reference substance was used. Each sample of the duodenal content was assayed for volume, PEG content, amylase and trypsin activity, pH and biliary secretion. No significant modifications of biliary and pancreatic secretions were demonstrated after irradiation, suggesting that these functions are not involved in the pathogenesis of the malabsorption radiation syndrome. (Auth.)

Pancreatic bicarbonate secretion involves two proton pumps.

Science.gov (United States)

Novak, Ivana; Wang, Jing; Henriksen, Katrine L; Haanes, Kristian A; Krabbe, Simon; Nitschke, Roland; Hede, Susanne E

2011-01-07

Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium express H(+)/HCO(3)(-) transporters, which depend on gradients created by the Na(+)/K(+)-ATPase. However, the model cannot fully account for high-bicarbonate concentrations, and other active transporters, i.e. pumps, have not been explored. Here we show that pancreatic ducts express functional gastric and non-gastric H(+)-K(+)-ATPases. We measured intracellular pH and secretion in small ducts isolated from rat pancreas and showed their sensitivity to H(+)-K(+) pump inhibitors and ion substitutions. Gastric and non-gastric H(+)-K(+) pumps were demonstrated on RNA and protein levels, and pumps were localized to the plasma membranes of pancreatic ducts. Quantitative analysis of H(+)/HCO(3)(-) and fluid transport shows that the H(+)-K(+) pumps can contribute to pancreatic secretion in several species. Our results call for revision of the bicarbonate transport physiology in pancreas, and most likely other epithelia. Furthermore, because pancreatic ducts play a central role in several pancreatic diseases, it is of high relevance to understand the role of H(+)-K(+) pumps in pathophysiology.

Novel Threshold Changeable Secret Sharing Schemes Based on Polynomial Interpolation.

Science.gov (United States)

Yuan, Lifeng; Li, Mingchu; Guo, Cheng; Choo, Kim-Kwang Raymond; Ren, Yizhi

2016-01-01

After any distribution of secret sharing shadows in a threshold changeable secret sharing scheme, the threshold may need to be adjusted to deal with changes in the security policy and adversary structure. For example, when employees leave the organization, it is not realistic to expect departing employees to ensure the security of their secret shadows. Therefore, in 2012, Zhang et al. proposed (t → t', n) and ({t1, t2,⋯, tN}, n) threshold changeable secret sharing schemes. However, their schemes suffer from a number of limitations such as strict limit on the threshold values, large storage space requirement for secret shadows, and significant computation for constructing and recovering polynomials. To address these limitations, we propose two improved dealer-free threshold changeable secret sharing schemes. In our schemes, we construct polynomials to update secret shadows, and use two-variable one-way function to resist collusion attacks and secure the information stored by the combiner. We then demonstrate our schemes can adjust the threshold safely.

Catechin secretion and phytotoxicity

Science.gov (United States)

Kaushik, Shail

2010-01-01

Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the “novel weapons hypothesis (NWH).” Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1–3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin. PMID:21057643

Pathogenesis of canine cortisol-secreting adrenocortical tumors

NARCIS (Netherlands)

Kool, Miriam

2015-01-01

In dogs, hypercortisolism is one of the most frequently observed endocrine disorders, with an estimated incidence of about 1-2 cases per 1000 dogs per year. Approximately 15% of these cases is due to a cortisol-secreting adrenocortical tumor (AT). Cortisol-secreting ATs are characterized by

Quantum secret sharing with classical Bobs

International Nuclear Information System (INIS)

Li Lvzhou; Qiu Daowen; Mateus, Paulo

2013-01-01

Boyer et al (2007 Phys. Rev. Lett. 99 140501) proposed a novel idea of semi-quantum key distribution, where a key can be securely distributed between Alice, who can perform any quantum operation, and Bob, who is classical. Extending the ‘semi-quantum’ idea to other tasks of quantum information processing is of interest and worth considering. In this paper, we consider the issue of semi-quantum secret sharing, where a quantum participant Alice can share a secret key with two classical participants, Bobs. After analyzing the existing protocol, we propose a new protocol of semi-quantum secret sharing. Our protocol is more realistic, since it utilizes product states instead of entangled states. We prove that any attempt of an adversary to obtain information necessarily induces some errors that the legitimate users could notice. (paper)

Molecular Mechanisms of Insulin Secretion and Insulin Action.

Science.gov (United States)

Flatt, Peter R.; Bailey, Clifford J.

1991-01-01

Information and current ideas on the factors regulating insulin secretion, the mechanisms underlying the secretion and biological actions of insulin, and the main characteristics of diabetes mellitus are presented. (Author)

Acute effects of clonidine and growth-hormone-releasing hormone on growth hormone secretion in patients with hyperthyroidism.

Science.gov (United States)

Giustina, A; Buffoli, M G; Bussi, A R; Wehrenberg, W B

1991-01-01

Patients with hyperthyroidism have reduced growth hormone (GH) responses to pharmacological stimuli and reduced spontaneous nocturnal GH secretion. The stimulatory effect of clonidine on GH secretion has been suggested to depend on an enhancement of hypothalamic GH-releasing hormone (GHRH) release. The aim of our study was to evaluate the effects of clonidine and GHRH on GH secretion in patients with hyperthyroidism. Eight hyperthyroid females with recent diagnosis of Graves' disease (age range 20-55 years, body mass index range 19.2-26.2 kg/m2) and 6 healthy female volunteers (age range 22-35 years, body mass index range 19-25 kg/m2) underwent two experimental trials at no less than 7-day intervals: (a) an intravenous infusion of clonidine 150 micrograms in 10 ml of saline, or (b) a bolus intravenous injection of human GHRH (1-29)NH2, 100 micrograms in 1 ml of saline. Hyperthyroid patients showed blunted GH peaks after clonidine (7.1 +/- 1.7 micrograms/l) as compared to normal subjects receiving clonidine (28.5 +/- 4.9 micrograms/l, p less than 0.05). GH peaks after GHRH were also significantly lower in hyperthyroid subjects (8.0 +/- 1.7 micrograms/l) as compared to normal subjects receiving GHRH (27.5 +/- 4.4 micrograms/l, p less than 0.05). No significant differences in the GH values either after clonidine or GHRH were observed in the two groups of subjects examined. Our data demonstrate that the GH responses to clonidine as well as to GHRH in patients with hyperthyroidism are inhibited in a similar fashion with respect to normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma HDL-cholesterol and triglycerides, but not LDL-cholesterol, are associated with insulin secretion in non-diabetic subjects.

Science.gov (United States)

Natali, Andrea; Baldi, Simona; Bonnet, Fabrice; Petrie, John; Trifirò, Silvia; Tricò, Domenico; Mari, Andrea

2017-04-01

Experimental data support the notion that lipoproteins might directly affect beta cell function, however clinical data are sparse and inconsistent. We aimed at verifying whether, independently of major confounders, serum lipids are associated with alterations in insulin secretion or clearance non-diabetic subjects. Cross sectional and observational prospective (3.5yrs), multicentre study in which 1016 non-diabetic volunteers aged 30-60yrs. and with a wide range of BMI (20.0-39.9kg/m 2 ) were recruited in a setting of University hospital ambulatory care (RISC study). baseline fasting lipids, fasting and OGTT-induced insulin secretion and clearance (measured by glucose and C-peptide modeling), peripheral insulin sensitivity (by the euglycemic clamp). Lipids and OGTT were repeated in 980 subjects after 3.5years. LDL-cholesterol did not show independent associations with fasting or stimulated insulin secretion or clearance. After accounting for potential confounders, HDL-cholesterol displayed negative and triglycerides positive independent associations with fasting and OGTT insulin secretion; neither with insulin clearance. Low HDL-cholesterol and high triglycerides were associated with an increase in glucose-dependent and a decrease in non-glucose-dependent insulin secretion. Over 3.5years both an HDL-cholesterol decline and a triglycerides rise were associated with an increase in fasting insulin secretion independent of changes in body weight or plasma glucose. LDL-cholesterol does not seem to influence any major determinant of insulin bioavailability while low HDL-cholesterol and high triglycerides might contribute to sustain the abnormalities in insulin secretion that characterize the pre-diabetic state. Copyright © 2017 Elsevier Inc. All rights reserved.

Investment in secreted enzymes during nutrient-limited growth is utility dependent.

Science.gov (United States)

Cezairliyan, Brent; Ausubel, Frederick M

2017-09-12

Pathogenic bacteria secrete toxins and degradative enzymes that facilitate their growth by liberating nutrients from the environment. To understand bacterial growth under nutrient-limited conditions, we studied resource allocation between cellular and secreted components by the pathogenic bacterium Pseudomonas aeruginosa during growth on a protein substrate that requires extracellular digestion by secreted proteases. We identified a quantitative relationship between the rate of increase of cellular biomass under nutrient-limiting growth conditions and the rate of increase in investment in secreted proteases. Production of secreted proteases is stimulated by secreted signals that convey information about the utility of secreted proteins during nutrient-limited growth. Growth modeling using this relationship recapitulated the observed kinetics of bacterial growth on a protein substrate. The proposed regulatory strategy suggests a rationale for quorum-sensing-dependent stimulation of the production of secreted enzymes whereby investment in secreted enzymes occurs in proportion to the utility they confer. Our model provides a framework that can be applied toward understanding bacterial growth in many environments where growth rate is limited by the availability of nutrients.

A secreted factor represses cell proliferation in Dictyostelium

OpenAIRE

Brock, Debra A.; Gomer, Richard H.

2005-01-01

Many cells appear to secrete factors called chalones that limit their proliferation, but in most cases the factors have not been identified. We found that growing Dictyostelium cells secrete a 60 kDa protein called AprA for autocrine proliferation repressor. AprA has similarity to putative bacterial proteins of unknown function. Compared with wild-type cells, aprA-null cells proliferate faster, while AprA overexpressing cells proliferate slower. Growing wild-type cells secrete a factor that i...

Neurotrophin Signaling Is Required for Glucose-Induced Insulin Secretion.

Science.gov (United States)

Houtz, Jessica; Borden, Philip; Ceasrine, Alexis; Minichiello, Liliana; Kuruvilla, Rejji

2016-11-07

Insulin secretion by pancreatic islet β cells is critical for glucose homeostasis, and a blunted β cell secretory response is an early deficit in type 2 diabetes. Here, we uncover a regulatory mechanism by which glucose recruits vascular-derived neurotrophins to control insulin secretion. Nerve growth factor (NGF), a classical trophic factor for nerve cells, is expressed in pancreatic vasculature while its TrkA receptor is localized to islet β cells. High glucose rapidly enhances NGF secretion and increases TrkA phosphorylation in mouse and human islets. Tissue-specific deletion of NGF or TrkA, or acute disruption of TrkA signaling, impairs glucose tolerance and insulin secretion in mice. We show that internalized TrkA receptors promote insulin granule exocytosis via F-actin reorganization. Furthermore, NGF treatment augments glucose-induced insulin secretion in human islets. These findings reveal a non-neuronal role for neurotrophins and identify a new regulatory pathway in insulin secretion that can be targeted to ameliorate β cell dysfunction. Copyright © 2016 Elsevier Inc. All rights reserved.

Cholinergic and VIPergic effects on thyroid hormone secretion in the mouse

International Nuclear Information System (INIS)

Ahren, B.

1985-01-01

The thyroid gland is known to harbor cholinergic and VIPergic nerves. In the present study, the influences of cholinergic stimulation by carbachol, cholinergic blockade by methylatropine and stimulation with various VIP sequences on basal, TSH-induced and VIP-induced thyroid hormone secretion were investigated in vivo in mice. The mice were pretreated with 125 I and thyroxine; the subsequent release of 125 I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was inhibited by both carbachol and methylatropine. Furthermore, TSH-induced radioiodine secretion was inhibited already by a low dose of carbachol. Moreover, a high dose of carbachol could inhibit VIP-induced radioiodine secretion. Methylatropine did not influence TSH- or VIP-stimulated radioiodine secretion, but counteracted the inhibitory action of carbachol on TSH- and VIP-induced radioiodine release. In addition, contrary to VIP, six various synthesized VIP fragments had no effect on basal or stimulated radioiodine release. It is concluded that basal thyroid hormone secretion is inhibited by both cholinergic activation and blockade. Furthermore, TSH-induced thyroid hormone secretion is more sensitive to inhibition with cholinergic stimulation than is VIP-induced thyroid hormone secretion. In addition, the VIP stimulation of thyroid hormone secretion seems to require the full VIP sequence

Discovery of the type VII ESX-1 secretion needle?

Science.gov (United States)

Ates, Louis S; Brosch, Roland

2017-01-01

Mycobacterium tuberculosis, the etiological agent of human tuberculosis, harbours five ESAT-6/type VII secretion (ESX/T7S) systems. The first esx gene clusters were identified during the genome-sequencing project of M. tuberculosis H37Rv. Follow-up studies revealed additional genes playing important roles in ESX/T7S systems. Among the latter genes, one can find those that encode Pro-Glu (PE) and Pro-Pro-Glu (PPE) proteins as well as a gene cluster that is encoded >260 kb upstream of the esx-1 locus and encodes ESX-1 secretion-associated proteins EspA (Rv3616c), EspC (Rv3615c) and EspD (Rv3614c). The espACD cluster has been suggested to have an important function in ESX-1 secretion since EspA-EspC and EsxA-EsxB are mutually co-dependent on each other for secretion. However, the molecular mechanism of this co-dependence and interaction between the substrates remained unknown. In this issue of Molecular Microbiology, Lou and colleagues show that EspC forms high-molecular weight polymerization complexes that resemble selected components of type II, III and/or IV secretion systems of Gram-negative bacteria. Indeed, EspC-multimeric complexes form filamentous structures that could well represent a secretion needle of ESX-1 type VII secretion systems. This exciting observation opens new avenues for research to discover and characterize ESX/T7S components and elucidates the co-dependence of EsxA/B secretion with EspA/C. © 2016 John Wiley & Sons Ltd.

Proteomic Identification of Novel Secreted Antibacterial Toxins of the Serratia marcescens Type VI Secretion System*

Science.gov (United States)

Fritsch, Maximilian J.; Trunk, Katharina; Diniz, Juliana Alcoforado; Guo, Manman; Trost, Matthias; Coulthurst, Sarah J.

2013-01-01

It has recently become apparent that the Type VI secretion system (T6SS) is a complex macromolecular machine used by many bacterial species to inject effector proteins into eukaryotic or bacterial cells, with significant implications for virulence and interbacterial competition. “Antibacterial” T6SSs, such as the one elaborated by the opportunistic human pathogen, Serratia marcescens, confer on the secreting bacterium the ability to rapidly and efficiently kill rival bacteria. Identification of secreted substrates of the T6SS is critical to understanding its role and ability to kill other cells, but only a limited number of effectors have been reported so far. Here we report the successful use of label-free quantitative mass spectrometry to identify at least eleven substrates of the S. marcescens T6SS, including four novel effector proteins which are distinct from other T6SS-secreted proteins reported to date. These new effectors were confirmed as antibacterial toxins and self-protecting immunity proteins able to neutralize their cognate toxins were identified. The global secretomic study also unexpectedly revealed that protein phosphorylation-based post-translational regulation of the S. marcescens T6SS differs from that of the paradigm, H1-T6SS of Pseudomonas aeruginosa. Combined phosphoproteomic and genetic analyses demonstrated that conserved PpkA-dependent threonine phosphorylation of the T6SS structural component Fha is required for T6SS activation in S. marcescens and that the phosphatase PppA can reverse this modification. However, the signal and mechanism of PpkA activation is distinct from that observed previously and does not appear to require cell–cell contact. Hence this study has not only demonstrated that new and species-specific portfolios of antibacterial effectors are secreted by the T6SS, but also shown for the first time that PpkA-dependent post-translational regulation of the T6SS is tailored to fit the needs of different bacterial

Secret rate - Privacy leakage in biometric systems

NARCIS (Netherlands)

Ignatenko, T.; Willems, F.M.J.

2009-01-01

Ahlswede and Csiszár [1993] introduced the concept of secret sharing. In their source model two terminals observe two correlated sequences. It is the objective of the terminals to form a common secret by interchanging a public message (helper data) in such a way that the secrecy leakage is

Security of the AES with a Secret S-Box

DEFF Research Database (Denmark)

Tiessen, Tyge; Knudsen, Lars Ramkilde; Kölbl, Stefan

2015-01-01

How does the security of the AES change when the S-box is replaced by a secret S-box, about which the adversary has no knowledge? Would it be safe to reduce the number of encryption rounds? In this paper, we demonstrate attacks based on integral cryptanalysis which allow to recover both the secret...... key and the secret S-box for respectively four, five, and six rounds of the AES. Despite the significantly larger amount of secret information which an adversary needs to recover, the attacks are very efficient with time/data complexities of 217/216, 238/240 and 290/264, respectively. Another...

Heterologous protein secretion in Lactococcus lactis: a novel antigen delivery system

Directory of Open Access Journals (Sweden)

Langella P.

1999-01-01

Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria and are generally regarded as safe (GRAS organisms. Therefore, LAB could be used for heterologous protein secretion and they are good potential candidates as antigen delivery vehicles. To develop such live vaccines, a better control of protein secretion is required. We developed an efficient secretion system in the model LAB, Lactococcus lactis. Staphylococcal nuclease (Nuc was used as the reporter protein. We first observed that the quantity of secreted Nuc correlated with the copy number of the cloning vector. The nuc gene was cloned on a high-copy number cloning vector and no perturbation of the metabolism of the secreting strain was observed. Replacement of nuc native promoter by a strong lactococcal one led to a significant increase of nuc expression. Secretion efficiency (SE of Nuc in L. lactis was low, i.e., only 60% of the synthesized Nuc was secreted. Insertion of a synthetic propeptide between the signal peptide and the mature moiety of Nuc increased the SE of Nuc. On the basis of these results, we developed a secretion system and we applied it to the construction of an L. lactis strain which secretes a bovine coronavirus (BCV epitope-protein fusion (BCV-Nuc. BCV-Nuc was recognized by both anti-BCV and anti-Nuc antibodies. Secretion of this antigenic fusion is the first step towards the development of a novel antigen delivery system based on LAB-secreting strains.

Human renin biosynthesis and secretion in normal and ischemic kidneys

International Nuclear Information System (INIS)

Pratt, R.E.; Carleton, J.E.; Richie, J.P.; Heusser, C.; Dzau, V.J.

1987-01-01

The pathway of renin biosynthesis and secretion in normal and ischemic human kidneys has been investigated by pulse-labeling experiments. The results indicate that in normal human kidney, preprorenin is rapidly processed to 47-kDa prorenin. Microradiosequencing showed that this molecule was generated by cleavage between Gly-23 and Leu-24, yielding a 43-amino acid proregion. Analysis of prorenin secreted by the kidney tissue yielded an identical sequence, indicating that prorenin is secreted without any further proteolysis. An examination of the kinetics of processing and secretion suggested that a majority of the newly synthesized prorenin is quickly secreted, while only a small fraction is processed intracellularly to the mature renin. The differences in secretion kinetics between prorenin and mature renin and the selective inhibition of prorenin secretion by monensin suggest that they are secreted independently via two pathways: a constitutive pathway probably from the Golgi or protogranules that rapidly release prorenin and a regulated pathway that secretes mature renin from the mature granules. A comparison of the kinetics of processing between normal and ischemic tissues suggests that renal ischemia leads to an overall increase in the rate of processing or prorenin to mature renin. In addition, prolonged biosynthetic labeling of renin in the ischemic kidney yielded two smaller molecular weight immunoreactive forms suggestive of renin fragments that may be degradative products. These fragments were not detected in normal kidney tissue labeled for similar lengths of time

Constitutive protein secretion from the exocrine pancreas of fetal rats

International Nuclear Information System (INIS)

Arvan, P.; Chang, A.

1987-01-01

Two general kinds of exocytotic secretion of proteins are known: that which is stimulated by secretagogues; and constitutive exocytosis, which is unable to be stimulated. The exocrine pancreas has often been cited as a model system for the first kind of secretion. However, the release of digestive enzymes from the exocrine pancreas of 1-day prenatal rats cannot be stimulated by secretagogues; therefore, its secretion is constitutive. To gain insight into the intracellular pathways which mediate secretion in the fetal gland, we examined the kinetics of release of newly synthesized proteins. We find that fetal pancreas in a steady state of secretion releases pulse-labeled secretory proteins in two kinetically distinct phases. The first phase occurring during 0-6.5 h of chase comprises approximately 12% of total incorporated radioactivity, the second phase beginning at greater than 7 h of chase comprises the remainder. Based on analysis by electron microscope autoradiography, radiolabel is localized during the first phase of secretion in immature granules/condensing vacuoles, Golgi compartments, and few mature granules. The second phase of secretion occurs when radiolabel is predominantly in mature granules. We propose that secretion occurs via (at least) 2 exocytotic routes, both of which are constitutive in fetal pancreatic tissue

Characterization of the macula densa stimulus for renin secretion

DEFF Research Database (Denmark)

Lorenz, J N; Weihprecht, H; Schnermann, J

1990-01-01

These studies utilize the isolated perfused rabbit juxtaglomerular apparatus (JGA) to study the macula densa signal for renin secretion in the absence of the confounding influences of intravascular pressure and renal nerve activity. In the first experimental series, JGAs were perfused alternately...... and decreases in macula densa NaCl concentration, and these changes are rapid and largely reversible, 2) the full renin response occurs within the concentration range normally occurring at the macula densa, i.e., below 80 mM Na+ and 61 mM Cl-, and 3) RSR responds with a larger change to alterations in Na...

Multiparty Quantum Secret Sharing of Quantum States Using Entanglement States

International Nuclear Information System (INIS)

Ying, Guo; Da-Zu, Huang; Gui-Hua, Zeng; Ho, Lee Moon

2008-01-01

A multi-partite-controlled quantum secret sharing scheme using several non-orthogonal entanglement states is presented with unconditional security. In this scheme, the participants share the secret quantum state by exchanging the secret polarization angles of the disordered travel particles. The security of the secret quantum state is also guaranteed by the non-orthogonal multi-partite-controlled entanglement states, the participants' secret polarizations, and the disorder of the travelling particles. Moreover, the present scheme is secure against the particle-number splitting attack and the intercept-and-resend attack. It may be still secure even if the distributed quantum state is embedded in a not-so-weak coherent-state pulse

Adaptive Secret Sharing for Color Images

Directory of Open Access Journals (Sweden)

Jia-Hong Li

2011-10-01

Full Text Available A secret sharing model can secure a secret over multiple noise-like shadows and remain recoverable despite multiple shadow failures. Even if some of the shadows are compromised, the secret will not be revealed as long as the number of the compromised shadows is smaller than a pre-determined threshold. Moreover, there are some necessary details of concerns: the malicious tampering on shadows must be detectable; the shadows must be concealed in a camouflage image with adequate quality to reduce suspicion and possible attack; color image properties must be considered. In addition to these concerns, in this paper, an adaptable mechanism is further designed to balance the hiding quantity and the quality of camouflage images depending on different applications.This is an important and interesting aspect that has never been discussed in previous research.

LcrQ and SycH function together at the Ysc type III secretion system in Yersinia pestis to impose a hierarchy of secretion.

Science.gov (United States)

Wulff-Strobel, Christine R; Williams, Andrew W; Straley, Susan C

2002-01-01

LcrQ is a regulatory protein unique to Yersinia. Previous study in Yersinia pseudotuberculosis and Yersinia enterocolitica prompted the model in which LcrQ negatively regulates the expression of a set of virulence proteins called Yops, and its secretion upon activation of the Yop secretion (Ysc) type III secretion system permits full induction of Yops expression. In this study, we tested the hypothesis that LcrQ's effects on Yops expression might be indirect. Excess LcrQ was found to exert an inhibitory effect specifically at the level of Yops secretion, independent of production, and a normal inner Ysc gate protein LcrG was required for this activity. However, overexpression of LcrQ did not prevent YopH secretion, suggesting that LcrQ's effects at the Ysc discriminate among the Yops. We tested this idea by determining the effects of deletion or overexpression of LcrQ, YopH and their common chaperone SycH on early Yop secretion through the Ysc. Together, our findings indicated that LcrQ is not a negative regulator directly, but it acts in partnership with SycH at the Ysc gate to control the entry of a set of Ysc secretion substrates. A hierarchy of YopH secretion before YopE appears to be imposed by SycH in conjunction with both LcrQ and YopH. LcrQ and SycH in addition influenced the deployment of LcrV, a component of the Yops delivery mechanism. Accordingly, LcrQ appears to be a central player in determining the substrate specificity of the Ysc.

Dietary factors and fibroblast growth factor-23 levels in young adults with African ancestry.

Science.gov (United States)

Kosk, Dominique; Kramer, Holly; Luke, Amy; Camacho, Pauline; Bovet, Pascal; Rhule, Jacob Plange; Forrester, Terrence; Wolf, Myles; Sempos, Chris; Melamed, Michal L; Dugas, Lara R; Cooper, Richard; Durazo-Arvizu, Ramon

2017-11-01

Fibroblast growth factor-23 (FGF23), a phosphaturic hormone secreted mainly by osteocytes, maintains serum phosphate levels within a tight range by promoting phosphaturia. Previous studies have mainly focused on the link between FGF23 levels and dietary intake of phosphate, but other dietary factors may also influence FGF23 levels. This cross-sectional study pooled three populations of young adults with African ancestry (452 in Chicago, IL, USA; 477 in Victoria, Seychelles; and 482 in Kumasi, Ghana) with estimated glomerular filtration rate >80 ml/min/1.73 m 2 to examine the association of dietary factors based on two 24-h recalls with FGF23 levels measured using a C-terminal assay. Linear regression was used to examine the association between log-transformed FGF23 levels and quartiles of calorie-adjusted dietary factors with adjustment for covariates. In the pooled sample of 1411 study participants, the mean age was 35.2 (6.2) years and 45.3% were male. Median plasma C-terminal FGF23 values in relative units (RU)/ml were 59.5 [interquartile range (IQR) 44.1, 85.3] in the USA, 43.2 (IQR 33.1, 57.9) in Seychelles, and 34.0 (IQR 25.2, 50.4) in Ghana. With adjustment for covariates, increasing quartiles of calcium and animal protein and decreasing quartiles of vegetable protein, fiber, and magnesium intake were associated with significantly higher FGF23 levels compared to the lowest quartile. After further adjustment for dietary factors, significant trends in FGF23 levels were noted only for quartiles of calcium, fiber, and magnesium intake (P young adults.

MONA Implementation Secrets

DEFF Research Database (Denmark)

Klarlund, Nils; Møller, Anders; Schwartzbach, Michael Ignatieff

2002-01-01

a period of six years. Compared to the first naive version, the present tool is faster by several orders of magnitude. This speedup is obtained from many different contributions working on all levels of the compilation and execution of formulas. We present a selection of implementation "secrets" that have...

Autophagy Mediates Interleukin-1β Secretion in Human Neutrophils

Directory of Open Access Journals (Sweden)

Leonardo Iula

2018-02-01

Full Text Available Interleukin-1β (IL-1β, a major pro-inflammatory cytokine, is a leaderless cytosolic protein whose secretion does not follow the classical endoplasmic reticulum-to-Golgi pathway, and for which a canonical mechanism of secretion remains to be established. Neutrophils are essential players against bacterial and fungi infections. These cells are rapidly and massively recruited from the circulation into infected tissues and, beyond of displaying an impressive arsenal of toxic weapons effective to kill pathogens, are also an important source of IL-1β in infectious conditions. Here, we analyzed if an unconventional secretory autophagy mechanism is involved in the exportation of IL-1β by these cells. Our findings indicated that inhibition of autophagy with 3-methyladenine and Wortmannin markedly reduced IL-1β secretion induced by LPS + ATP, as did the disruption of the autophagic flux with Bafilomycin A1 and E64d. These compounds did not noticeable affect neutrophil viability ruling out that the effects on IL-1β secretion were due to cell death. Furthermore, VPS34IN-1, a specific autophagy inhibitor, was still able to reduce IL-1β secretion when added after it was synthesized. Moreover, siRNA-mediated knockdown of ATG5 markedly reduced IL-1β secretion in neutrophil-differentiated PLB985 cells. Upon LPS + ATP stimulation, IL-1β was incorporated to an autophagic compartment, as was revealed by its colocalization with LC3B by confocal microscopy. Overlapping of IL-1β-LC3B in a vesicular compartment peaked before IL-1β increased in culture supernatants. On the other hand, stimulation of autophagy by cell starvation augmented the colocalization of IL-1β and LC3B and then promoted neutrophil IL-1β secretion. In addition, specific ELISAs indicated that although both IL-1β and pro-IL-1β are released to culture supernatants upon neutrophil stimulation, autophagy only promotes IL-1β secretion. Furthermore, the serine proteases inhibitor

31 CFR 401.1 - Secret Service agents authorized to make seizures.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Secret Service agents authorized to... Finance (Continued) SECRET SERVICE, DEPARTMENT OF THE TREASURY SEIZURE AND FORFEITURE OF VESSELS, VEHICLES... Secret Service agents authorized to make seizures. All officers of the U.S. Secret Service engaged in the...

Uteroglobin, an apically secreted protein of the uterine epithelium, is secreted non-polarized form MDCK cells and mainly basolaterally from Caco-2 cells

DEFF Research Database (Denmark)

Vogel, L K; Suske, G; Beato, M

1993-01-01

A complete cDNA encoding rabbit uteroglobin was constructed and expressed in MDCK and Caco-2 cells. The MDCK cells secrete uteroglobin in approximately equal amounts to the apical and the basolateral side, whereas the Caco-2 cells secrete uteroglobin mainly to the basolateral side. Both MDCK...... and Caco-2 cells thus secrete uteroglobin in a non-sorted manner. It has, however, previously been shown that uteroglobin is secreted exclusively at the apical membrane in primary cell culture of endometrial epithelial cells [S.K. Mani et al. (1991) Endocrinology 128, 1563-1573]. This suggests that either...... the endometrial epithelium has an apical default pathway or recognises a sorting signal not recognised by MDCK cells and Caco-2 cells. Our data thus show that a soluble molecule can be secreted at the apical, the basolateral or both membranes depending on the cell type....

Excreted/Secreted Proteins from Trypanosome Procyclic Strains

Directory of Open Access Journals (Sweden)

Celestine Michelle Atyame Nten

2010-01-01

Full Text Available Trypanosoma secretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in the Glossina midgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains of T. brucei gambiense and T. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized in T. brucei brucei and T. brucei gambiense secretomes, respectively; 35% and 42% of the corresponding secretome proteins were specifically secreted by T. brucei brucei and T. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.

Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans

DEFF Research Database (Denmark)

Mertz-Nielsen, Anette; Hillingsø, J; Bukhave, Klaus

1996-01-01

this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n=17) and after pretreatment with high......H 6.9 v 6.8; p>0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mu mol/h; pstimulated (834 (72) v 474 (66) mu mol/h; pstimulated (3351 (678) v 2550 (456) mu mol/h; p>0.05) duodenal bicarbonate secretion compared with control...... experiments. Also the combination of omeprazole and ranitidine increased (p=0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid...

The Effects of Secret Instructions and Yes/no Questions on Maltreated and Non-maltreated Children's Reports of a Minor Transgression.

Science.gov (United States)

Ahern, Elizabeth C; Stolzenberg, Stacia N; McWilliams, Kelly; Lyon, Thomas D

2016-11-01

This study examined the effects of secret instructions (distinguishing between good/bad secrets and encouraging disclosure of bad secrets) and yes/no questions (DID: "Did the toy break?" versus DYR: "Do you remember if the toy broke?") on 262 maltreated and non-maltreated children's (age range 4-9 years) reports of a minor transgression. Over two-thirds of children failed to disclose the transgression in response to free recall (invitations and cued invitations). The secret instruction increased disclosures early in free recall, but was not superior to no instruction when combined with cued invitations. Yes/no questions specifically asking about the transgression elicited disclosures from almost half of the children who had not previously disclosed, and false alarms were rare. DYR questions led to ambiguous responding among a substantial percentage of children, particularly younger children. The findings highlight the difficulties of eliciting transgression disclosures without direct questions. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Salivary Gland Secretion.

Science.gov (United States)

Dorman, H. L.; And Others

1981-01-01

Describes materials and procedures for an experiment utilizing a live dog to demonstrate: (1) physiology of the salivary gland; (2) parasympathetic control of the salivary gland; (3) influence of varying salivary flow rates on sodium and potassium ions, osmolarity and pH; and (4) salivary secretion as an active process. (DS)

The effect of imiquimod on taste bud calcium transients and transmitter secretion

Science.gov (United States)

Wu, Sandy Y

2016-01-01

Background and Purpose Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell–cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. Experimental Approach Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste‐evoked ATP secretion from mouse taste buds. Key Results Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca2+ concentrations. These Ca2 + responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca2 +‐ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca2 + mobilization elicited by imiquimod was dependent on release from internal Ca2 + stores. Moreover, combining studies of Ca2 + imaging with cellular biosensors showed that imiquimod evoked secretion of 5‐HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste‐evoked ATP secretion. Conclusion and Implications Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5‐HT signalling. PMID:27464850

Computed tomographic study of hormone-secreting microadenomas

International Nuclear Information System (INIS)

Hemminghytt, S.; Kalkhoff, R.K.; Daniels, D.L.; Williams, A.L.; Grogan, J.P.; Haughton, V.M.

1983-01-01

A review was made of the computed tomographic (CT) studies of 33 patients with hormone-secreting microadenomas that had been verified by transsphenoidal surgery and endocrinologic evaluation. In previous studies in small series of patients, the CT appearance of pituitary microadenomas has been reported as hypodense, isodense, and hyperdense. In this study, CT showed a region of diminished enhancement and ususally an enlarged pituitary gland in cases of prolactin-secreting adenomas. HGH- or ACTH-secreting adenomas were less consistently hypodense. It is concluded that hypodensity and enlargement in the pituitary gland are the most useful criteria for identification of microadenomas. Some technical factors that may affect the CT appearance of microadenomas and lead to conflicting reports are discussed

Exploring Quantum Supremacy in Access Structures of Secret Sharing by Coding Theory

OpenAIRE

Matsumoto, Ryutaroh

2018-01-01

We consider secret sharing schemes with a classical secret and quantum shares. One example of such schemes was recently reported whose access structure cannot be realized by any secret sharing schemes with classical shares. In this paper, we report further quantum secret sharing schemes whose access structures cannot be realized by any classical secret sharing schemes.

Weegee’s City Secrets

Directory of Open Access Journals (Sweden)

Alan TRACHTENBERG

2010-03-01

Full Text Available En tant que photographe indépendant de meurtres, d’accidents, d’incendies, mais aussi de moments de loisirs dans la ville — de scènes de violence et de plaisir — Weegee travaillait essentiellement la nuit et utilisait un flash puissant associé à son appareil-photo de presse. Ses « secrets pour réaliser des photographies avec un flash » consistent à donner des conseils pratiques et techniques pour débutants. Mais au cœur de la rhétorique de ses « secrets » se trouvent des réflexions subtiles et convaincantes révélant la relation entre la lumière et l’obscurité, et plus particulièrement la manière dont la lumière du flash permet de rendre visible l’obscurité. Dans le récit de Weegee, le flash confère à la photographie le pouvoir d’écrire — d’écrire avec la lumière, un mode de représentation singulièrement approprié pour enregistrer des instants de vie dans les rues nocturnes de la ville.As a freelance photographer of crime, accidents, fires, and also of the recreational life of the city—scenes of violence and of pleasure—Weegee worked mainly at night and employed a powerful photoflash attachment to his press camera. His "secrets of shooting with photoflash" consist of practical technical advice for beginners. But within the rhetoric of his "secrets" there lie cogent and subtle reflections on the relation of light to darkness, especially on the way the flash of light makes darkness visible. In Weegee’s account, the photoflash gives photography the power of writing—writing with light, a mode of picturing uniquely suited to recording instants of life on city streets at night.

Biliary cholesterol secretion : More than a simple ABC

NARCIS (Netherlands)

Dikkers, Arne; Tietge, Uwe J. F.

2010-01-01

Biliary cholesterol secretion is a process important for 2 major disease complexes, atherosclerotic cardiovascular disease and cholesterol gallstone disease With respect to cardiovascular disease, biliary cholesterol secretion is regarded as the final step for the elimination of cholesterol

5 CFR 1312.26 - Control of secret and confidential material.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Control of secret and confidential... Accountability of Classified Information § 1312.26 Control of secret and confidential material. Classified... Document Control, will be used to establish accountability controls on all Secret material received or...

Secret quality of love.

Science.gov (United States)

Strachan-Hall, Elaine

2016-09-01

Many of us can recite three Donabedian dimensions of the quality of care of structure, process and outcome. Recently, I was introduced to another of Avedis Donabedian's quotes about the 'secret quality of love'.

Vote Markets, Latent Opportunism, and the Secret Ballot

DEFF Research Database (Denmark)

Justesen, Mogens Kamp; Bøttkjær, Louise Thorn; Gates, Scott

The secret ballot is a cornerstone of modern democracy because it protects voter autonomy and allows voters to express their political preferences freely without fear of repercussions. In theory, the secret ballot is supposed to prevent vote buying – the exchange of votes for money or material...... goods – from operating during elections. Yet, empirical evidence from surveys around the world suggests that vote buying is a common feature of elections in new democracies. Indeed, a fundamental puzzle concerns why political parties use vote buying to mobilize electoral support when the secret ballot...... allows voters to renege on their commitments and vote as they please. In this paper, we address this puzzle by arguing that voter perceptions of ballot secrecy affect their responses to vote buying offers. Theoretically, we develop a game theoretical model, where voter beliefs in the secret ballot guide...

Cryptanalysis of 'less short' RSA secret exponents

NARCIS (Netherlands)

Verheul, E.R.; Tilborg, van H.C.A.

1997-01-01

In some applications of RSA, it is desirable to have a short secret exponent d. Wiener [6], describes a technique to use continued fractions (CF) in a cryptanalytic attack on an RSA cryptosystem having a ‘short’ secret exponent. Let n=p¿·¿q be the modulus of the system. In the typical case that

Measurement of secretion in nasal lavage

DEFF Research Database (Denmark)

Bisgaard, H; Krogsgaard, O W; Mygind, N

1987-01-01

1. The amount of admixture in nasal lavage fluids was determined by addition of 99mTc labelled albumin, providing a correction factor for measurements of cellular material and humoral substances in nasal lavage return as well as a quantitative measure of nasal secretions. 2. Albumin was chosen...... secretion to be carried out on the whole sample of lavage fluid, thereby avoiding the necessity of complete admixture between marker and lavage fluid which would be pertinent to marker molecules measured chemically. The radiation from a nasal lavage is minimal and the procedure is fully acceptable...... of the nose, yet not the oropharynx. 5. A dose related increase in nasal secretion harvested by the nasal lavage in 10 persons challenged with histamine chloride could be demonstrated by this technique. 6. It is concluded that the use of 99mTc-albumin in a nasal washing provides a safe, simple and quick...

Apical secretion of apolipoproteins from enterocytes

DEFF Research Database (Denmark)

Danielsen, E M; Hansen, Gert Helge; Poulsen, Mona Dam

1993-01-01

Synthesis and secretion of apolipoproteins in pig small intestine was studied by pulse-chase labeling of jejunal segments, kept in organ culture. Apo A-1 and apo B-48 were the two major proteins released, constituting 25 and 10%, respectively, of the total amount of labeled protein in the mucosal...... in the soluble fraction, suggesting a basolateral secretion into the intercellular space, and both this accumulation and the release to the medium was prevented by culture at 20 degrees C. The specific radioactivity of apo A-1 and apo B-48 released to the medium was significantly higher than...... that enterocytes release most of their newly made free apo A-1 and a significant portion of apo B-48 by exocytosis via the brush border membrane into the intestinal lumen. Fat absorption reduced apolipoprotein secretion to the medium and induced the formation of chylomicrons, containing apo A-1 at their surface...

Human placenta secretes apolipoprotein B-100-containing lipoproteins

DEFF Research Database (Denmark)

Munk-Madsen, Eva; Lindegaard, Marie Louise Skakkebæk; Andersen, Claus B

2004-01-01

Supply of lipids from the mother is essential for fetal growth and development. In mice, disruption of yolk sac cell secretion of apolipoprotein (apo) B-containing lipoproteins results in embryonic lethality. In humans, the yolk sac is vestigial. Nutritional functions are instead established very...... lipoproteins secreted from placental tissue showed spherical particles with a diameter of 47 +/- 10 nm. These results demonstrate that human placenta expresses both apoB and MTP and consequently synthesize and secrete apoB-100-containing lipoproteins. Placental lipoprotein formation constitutes a novel pathway...

Ranitidine has no influence on tubular creatinine secretion

NARCIS (Netherlands)

van den Berg, J. G.; Koopman, M. G.; Arisz, L.

1996-01-01

Oral cimetidine competitively inhibits tubular secretion of creatinine. We investigated the potential of oral ranitidine, a comparable H2-receptor antagonist, to block tubular creatinine secretion. In 10 healthy subjects, clearances of inulin and endogenous creatinine were simultaneously measured

42 CFR 405.215 - Confidential commercial and trade secret information.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Confidential commercial and trade secret information. 405.215 Section 405.215 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... trade secret information. To the extent that CMS relies on confidential commercial or trade secret...

Overexpressing key component genes of the secretion pathway for enhanced secretion of an Aspergillus niger glucose oxidase in Trichoderma reesei.

Science.gov (United States)

Wu, Yilan; Sun, Xianhua; Xue, Xianli; Luo, Huiying; Yao, Bin; Xie, Xiangming; Su, Xiaoyun

2017-11-01

Vast interest exists in developing T. reesei for production of heterologous proteins. Although rich genomic and transcriptomic information has been uncovered for the T. reesei secretion pathway, little is known about whether engineering its key components could enhance expression of a heterologous gene. In this study, snc1, a v-SNARE gene, was first selected for overexpression in T. reesei. In engineered T. reesei with additional copies of snc1, the Aspergillus niger glucose oxidase (AnGOD) was produced to a significantly higher level (2.2-fold of the parental strain). hac1 and bip1, two more component genes in the secretion pathway, were further tested for overexpression and found to be also beneficial for AnGOD secretion. The overexpression of one component gene more or less affected the expression of the other two genes, suggesting a complex regulating mechanism. Our study demonstrates the potential of engineering the secretion pathway for enhancing heterologous gene production in T. reesei. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimal Black-Box Secret Sharing over Arbitrary Abelian Groups

DEFF Research Database (Denmark)

Cramer, Ronald; Fehr, Serge

2002-01-01

A black-box secret sharing scheme for the threshold access structure T t,n is one which works over any finite Abelian group G. Briefly, such a scheme differs from an ordinary linear secret sharing scheme (over, say, a given finite field) in that distribution matrix and reconstruction vectors...... are defined over ℤ and are designed independently of the group G from which the secret and the shares are sampled. This means that perfect completeness and perfect privacy are guaranteed regardless of which group G is chosen. We define the black-box secret sharing problem as the problem of devising......, for an arbitrary given T t,n , a scheme with minimal expansion factor, i.e., where the length of the full vector of shares divided by the number of players n is minimal. Such schemes are relevant for instance in the context of distributed cryptosystems based on groups with secret or hard to compute group order...

Threshold secret sharing scheme based on phase-shifting interferometry.

Science.gov (United States)

Deng, Xiaopeng; Shi, Zhengang; Wen, Wei

2016-11-01

We propose a new method for secret image sharing with the (3,N) threshold scheme based on phase-shifting interferometry. The secret image, which is multiplied with an encryption key in advance, is first encrypted by using Fourier transformation. Then, the encoded image is shared into N shadow images based on the recording principle of phase-shifting interferometry. Based on the reconstruction principle of phase-shifting interferometry, any three or more shadow images can retrieve the secret image, while any two or fewer shadow images cannot obtain any information of the secret image. Thus, a (3,N) threshold secret sharing scheme can be implemented. Compared with our previously reported method, the algorithm of this paper is suited for not only a binary image but also a gray-scale image. Moreover, the proposed algorithm can obtain a larger threshold value t. Simulation results are presented to demonstrate the feasibility of the proposed method.

Share Conversion, Pseudorandom Secret-Sharing and Applications to Secure Computation

NARCIS (Netherlands)

R.J.F. Cramer (Ronald); I.B. Damgård (Ivan); Y. Ishai

2005-01-01

htmlabstractWe present a method for converting shares of a secret into shares of the same secret in a different secret-sharing scheme using only local computation and no communication between players. In particular, shares in a replicated scheme based on a CNF representation of the access structure

Multiparty secret sharing of quantum information based on entanglement swapping

International Nuclear Information System (INIS)

Li Yongmin; Zhang Kuanshou; Peng Kunchi

2004-01-01

A protocol of multiparty secret sharing of quantum information based on entanglement swapping is analyzed. In this protocol, Bell states are needed in order to realize the quantum information secret sharing and it is convenient to realize the quantum secret sharing among the members of any subset of users

On the diversity-multiplexing tradeoff of secret-key agreement over multiple-antenna channels

KAUST Repository

Zorgui, Marwen

2014-09-01

We consider secret-key agreement with public discussion over Rayleigh fading quasi-static channels. First, the secret-key diversity gain and the secret-key multiplexing gain are defined. Then, the secret-key diversity multiplexing tradeoff (DMT) is established. The eavesdropper is shown to \\'steal\\' only transmit antennas. We show that likewise the DMT without secrecy constraint, the secret-key DMT is the same either with or without full channel state information (CSI) at the transmitter (CSI-T). This insensitivity of secret-key DMT toward CSI-T highlights a fundamental difference between secret-key agreement and the wiretap channel whose secret DMT depends crucially on CSI-T. Several secret-key DMT-achieving schemes are presented in case of full CSI-T.

On the diversity-multiplexing tradeoff of secret-key agreement over multiple-antenna channels

KAUST Repository

Zorgui, Marwen; Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

2014-01-01

We consider secret-key agreement with public discussion over Rayleigh fading quasi-static channels. First, the secret-key diversity gain and the secret-key multiplexing gain are defined. Then, the secret-key diversity multiplexing tradeoff (DMT) is established. The eavesdropper is shown to 'steal' only transmit antennas. We show that likewise the DMT without secrecy constraint, the secret-key DMT is the same either with or without full channel state information (CSI) at the transmitter (CSI-T). This insensitivity of secret-key DMT toward CSI-T highlights a fundamental difference between secret-key agreement and the wiretap channel whose secret DMT depends crucially on CSI-T. Several secret-key DMT-achieving schemes are presented in case of full CSI-T.

Secret Sharing Schemes and Advanced Encryption Standard

Science.gov (United States)

2015-09-01

25 4.7 Computational Example . . . . . . . . . . . . . . . . . . . . . 26 5 Side-Channel Effect on Advanced Encryption Standard ( AES ) 31...improvements, and to build upon them to discuss the side-channel effects on the Advanced Encryption Standard ( AES ). The following questions are asked...secret sharing scheme? • Can the improvements to the current secret sharing scheme prove to be beneficial in strengthening/weakening AES encryption

Lifestyle, mental health status and salivary secretion rates.

Science.gov (United States)

Toda, Masahiro; Morimoto, Kanehisa; Fukuda, Sanae; Hayakawa, Kazuo

2002-01-01

The relations between salivary variables, lifestyle and mental health status were investigated for 61 healthy female university students. The salivary secretion rates were significantly higher in the good lifestyle groups compared with the poor lifestyle groups. Among the 8 lifestyle items tested. "eating breakfast" and "mental stress" were significantly related to the salivary secretion rates. The present findings suggest that the acquisition of a good lifestyle is also very important from the viewpoint of the prevention of oral disease.A highly significant correlation (r=0.97; p<0.01) between the salivary cortisol levels and the cortisol secretion rates when controlled for the salivary secretion rates was also observed. This suggests that there is a high correlation between the intact salivary cortisol levels and the total cortisol quantity per unit time. Therefore, both these values can be used as a good index for the salivary cortisol determination.

Six secrets of champagne

Science.gov (United States)

Liger-Belair, Gérard

2015-12-01

Popping open a bottle of champagne is one of life's great delights, but how much do you really know about the science behind this greatest of wines? Gérard Liger-Belair reveals his six favourite champagne secrets.

Sur les usages publics du secret : les archives du Service Secret Communiste Roumain

Directory of Open Access Journals (Sweden)

Andi Mihalache

2009-10-01

Full Text Available L’étude s’occupe des dossiers de l’ancienne police politique du régime communiste de Roumanie, la Securitate. Il a comme point de départ le fait que la mémoire sociale, le contexte politique et les débats publics actuels influencent la recherche historique, modifiant les perceptions sur le document d’archive. Ce dernier n’est plus vu seulement comme source principale de la recherche historique, devenant outil redoutable dans les disputes électorales, car, en base des informations extraites d’un dossier de la Securitate, l’on peut évincer un adversaire incommode. Se montrant utile à dénoncer la collaboration de quelqu’un sous le régime communiste, le document d’archive a acquis des mises symboliques imprévues, étant caché, protégé, volé, racheté, truqué, perdu et redécouvert à commande. Toutes ces pratiques compromettent de plus en plus les chances des historiens de reconstituer de manière crédible l’histoire récente des Roumains. On obtient difficilement l’accès aux dossiers de la Securitate, la patrimonialisation excessive des documents - en vérité leur trésorisation - étant conséquence directe du prestige idéologique et social que le secret détenait au temps communiste.This article focuses on the Securitate files as a political stake, but also as first rank sources for academic research, not from the current perspective of recent history, but from that of cultural history. In post-communist Romania, silence is the secret’s poor relative and confidentiality its respectable form. Ironically or not, we could state that in our country the secrets of communist repression are literally protected by law. The secret is an unbidden, illegitimate competence. In its ethics it does not matter what is good and what is bad, what is true and what is false. The main interest is what is said and what isn’t. The secret being a convention, a pact, the gesture of not saying seems to be more important than

Security of a kind of quantum secret sharing with entangled states.

Science.gov (United States)

Wang, Tian-Yin; Liu, Ying-Zhao; Wei, Chun-Yan; Cai, Xiao-Qiu; Ma, Jian-Feng

2017-05-30

We present a new collusion attack to a kind of quantum secret sharing schemes with entangled states. Using this attack, an unauthorized set of agents can gain access to the shared secret without the others' cooperation. Furthermore, we establish a general model for this kind of quantum secret sharing schemes and then give some necessary conditions to design a secure quantum secret sharing scheme under this model.

A linear construction of perfect secret sharing schemes

NARCIS (Netherlands)

Dijk, van M.; Santis, De A.

1995-01-01

In this paper, we generalize the vector space construction due to Brickell [5]. This generalization, introduced by Bertilsson [1], leads to perfect secret sharing schemes with rational information rates in which the secret can be computed efficiently by each qualified group. A one to one

Secretion of Flavins by Three Species of Methanotrophic Bacteria▿ †

OpenAIRE

Balasubramanian, Ramakrishnan; Levinson, Benjamin T.; Rosenzweig, Amy C.

2010-01-01

We detected flavins in the growth medium of the methanotrophic bacterium Methylocystis species strain M. Flavin secretion correlates with growth stage and increases under iron starvation conditions. Two other methanotrophs, Methylosinus trichosporium OB3b and Methylococcus capsulatus (Bath), secrete flavins, suggesting that flavin secretion may be common to many methanotrophic bacteria.

Clinical characteristics of patients with thyrotropin-secreting pituitary adenoma.

Science.gov (United States)

Wu, Yung-Yen; Chang, Hung-Yu; Lin, Jen-Der; Chen, Kwang-Wen; Huang, Yu-Yao; Jung, Shih-Ming

2003-03-01

Thyroid-stimulating hormone (thyrotropin, TSH)-secreting pituitary adenoma is a very rare cause of hyperthyroidism. Diagnosis of this condition is often delayed due to lack of availability of TSH radioimmunoassay (RIA), the failure to recognize the utility of RIA and the incorrect attribution of the condition to other causes of thyrotoxicosis. This retrospective study analyzed the clinical characteristics of patients with this disorder treated from 1991 to 2002. Seven patients (6 females, 1 male; mean age, 48 years; range, 33 to 72 years) with a diagnosis of TSHsecreting pituitary adenoma based on detectable TSH levels with high serum free thyroid hormone or triiodothyronine concentrations and pituitary lesions found on neuroimaging were included in this study. Patient records including clinical features, endocrine studies, immunohistochemistry studies, and response to treatment were reviewed. All 7 patients had hyperthyroidism, elevated free thyroxine or triiodothyronine levels, and unsuppressed levels of TSH. Imaging studies demonstrated a pituitary mass or lesion in all patients. Six patients had macroadenomas and 1 patient had a microadenoma. One of the patients had coexisting acromegalic features and hypersecretion of growth hormone was diagnosed. All of the patients had been treated with thionamides or thyroidectomy for presumed primary hyperthyroidism. Serum alpha-subunit level was uncharacteristically normal in 2 patients and elevated in 1 patient. Alpha-subunit/TSH molar ratios were elevated in 3 patients. Five patients underwent transsphenoidal adenomectomy but only one of them remained well-controlled at follow-up. Three patients received administration of somatostatin analogs and they achieved normalization of serum TSH and free thyroid hormones during the period of therapy. TSH immunoassay has an important role in the evaluation of hyperthyroid patients to determine the presence of inappropriate secretion. TSH-secreting pituitary adenoma exhibits

Analysis of Secreted Proteins Using SILAC

DEFF Research Database (Denmark)

Henningsen, Jeanette; Blagoev, Blagoy; Kratchmarova, Irina

2014-01-01

Secreted proteins serve a crucial role in the communication between cells, tissues, and organs. Proteins released to the extracellular environment exert their function either locally or at distant points of the organism. Proteins are secreted in a highly dynamic fashion by cells and tissues...... in the body responding to the stimuli and requirements presented by the extracellular milieu. Characterization of secretomes derived from various cell types has been performed using different quantitative mass spectrometry-based proteomics strategies, several of them taking advantage of labeling with stable...

Information Theoretic Secret Key Generation: Structured Codes and Tree Packing

Science.gov (United States)

Nitinawarat, Sirin

2010-01-01

This dissertation deals with a multiterminal source model for secret key generation by multiple network terminals with prior and privileged access to a set of correlated signals complemented by public discussion among themselves. Emphasis is placed on a characterization of secret key capacity, i.e., the largest rate of an achievable secret key,…

Cell secretion machinery: Studies using the AFM

International Nuclear Information System (INIS)

Jena, Bhanu P.

2006-01-01

A new field in biology, 'nano-cell biology', has emerged from the successful use of force microscopy in understanding the structure and dynamics of cells and biomolecules, at nm resolution and in real time. Atomic force microscopy, in combination with conventional tools and approaches (electron microscopy, electrophysiology, X-ray diffraction, photon correlation spectroscopy, mass spectroscopy, biochemistry, and molecular biology), has revealed for the first time, the universal molecular machinery and mechanism of secretion in cells. Secretion occurs in all living cells and involves the delivery of intracellular products to the cell exterior. Secretory products are packaged and stored in membranous sacs or vesicles within the cell. When the cell needs to secrete these products, the secretory vesicles containing them, dock and fuse at plasma membrane-associated supramolecular structures called Porosome, to release their contents. Specialized cells for neurotransmission, enzyme secretion, or hormone release utilize a highly regulated secretory process. During secretion, swelling of secretory vesicles results in a build-up of intravesicular pressure, allowing expulsion of vesicular contents. The extent of vesicle swelling dictates the amount of vesicular contents expelled. The discovery of the porosome as the universal secretory machinery, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution into artificial lipid membrane, have been determined. The molecular mechanism of secretory vesicle swelling, and the fusion of opposing bilayers, i.e., the fusion of secretory vesicle membrane at the base of the porosome membrane, has also been resolved

Variable effects of soman on macromolecular secretion by ferret trachea

International Nuclear Information System (INIS)

McBride, R.K.; Zwierzynski, D.J.; Stone, K.K.; Culp, D.J.; Marin, M.G.

1991-01-01

The purpose of this study was to examine the effect of the anticholinesterase agent, soman, on macromolecular secretion by ferret trachea, in vitro. We mounted pieces of ferret trachea in Ussing-type chambers. Secreted sulfated macromolecules were radiolabeled by adding 500 microCi of 35 SO 4 to the submucosal medium and incubating for 17 hr. Soman added to the submucosal side produced a concentration-dependent increase in radiolabeled macromolecular release with a maximal secretory response (mean +/- SD) of 202 +/- 125% (n = 8) relative to the basal secretion rate at a concentration of 10 - 7 M. The addition of either 10 -6 M pralidoxime (acetylcholinesterase reactivator) or 10 -6 M atropine blocked the response to 10 -7 M soman. At soman concentrations greater than 10 -7 M, secretion rate decreased and was not significantly different from basal secretion. Additional experiments utilizing acetylcholine and the acetylcholinesterase inhibitor, physostigmine, suggest that inhibition of secretion by high concentrations of soman may be due to a secondary antagonistic effect of soman on muscarinic receptors

Trade Secrets in the Legal Studies Curriculum--A Case Study

Science.gov (United States)

Evans, Michelle

2012-01-01

Trade secrets can be a valuable company asset because of their potential to last forever. Unfortunately, along with such a significant benefit, there is also a significant risk--the risk that the trade secret can be lost in an instant if it is not sufficiently protected. Companies must be vigilant in protecting these secrets. However, the law is…

Multiple Factors Related to the Secretion of Glucagon-Like Peptide-1

Directory of Open Access Journals (Sweden)

XingChun Wang

2015-01-01

Full Text Available The glucagon-like peptide-1 is secreted by intestinal L cells in response to nutrient ingestion. It regulates the secretion and sensitivity of insulin while suppressing glucagon secretion and decreasing postprandial glucose levels. It also improves beta-cell proliferation and prevents beta-cell apoptosis induced by cytotoxic agents. Additionally, glucagon-like peptide-1 delays gastric emptying and suppresses appetite. The impaired secretion of glucagon-like peptide-1 has negative influence on diabetes, hyperlipidemia, and insulin resistance related diseases. Thus, glucagon-like peptide-1-based therapies (glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are now well accepted in the management of type 2 diabetes. The levels of glucagon-like peptide-1 are influenced by multiple factors including a variety of nutrients. The component of a meal acts as potent stimulants of glucagon-like peptide-1 secretion. The levels of its secretion change with the intake of different nutrients. Some drugs also have influence on GLP-1 secretion. Bariatric surgery may improve metabolism through the action on GLP-1 levels. In recent years, there has been a great interest in developing effective methods to regulate glucagon-like peptide-1 secretion. This review summarizes the literature on glucagon-like peptide-1 and related factors affecting its levels.

Cooperative Secret Sharing Using QR Codes and Symmetric Keys

Directory of Open Access Journals (Sweden)

Yang-Wai Chow

2018-04-01

Full Text Available Secret sharing is an information security technique where a dealer divides a secret into a collection of shares and distributes these to members of a group. The secret will only be revealed when a predefined number of group members cooperate to recover the secret. The purpose of this study is to investigate a method of distributing shares by embedding them into cover Quick Response (QR codes in a secure manner using cryptographic keys. The advantage of this approach is that the shares can be disseminated over public channels, as anyone who scans the QR codes will only obtain public information. Only authorized individuals who are in possession of the required keys will be able to recover the shares. This also means that when group members cooperate to recover a secret, the group can determine the presence of an illegitimate participant if the person does not produce a valid share. This study proposes a protocol for accomplishing this and discusses the underlying security of the protocol.

Multiparty Quantum Secret Sharing of Secure Direct Communication Using Teleportation

International Nuclear Information System (INIS)

Wang Jian; Zhang Quan; Tang Chaojing

2007-01-01

We present an (n,n) threshold quantum secret sharing scheme of secure direct communication using Greenberger-Horne-Zeilinger state and teleportation. After ensuring the security of the quantum channel, the sender encodes the secret message directly on a sequence of particle states and transmits it to the receivers by teleportation. The receivers can recover the secret message by combining their measurement results with the sender's result. If a perfect quantum channel is used, our scheme is completely secure because the transmitting particle sequence does not carry the secret message. We also show our scheme is secure for noise quantum channel.

Post-translational processing and secretion of atrial natriuretic factor

International Nuclear Information System (INIS)

Shields, P.P.

1988-01-01

The post-translational processing and regulated secretion of atrial natriuretic factor (ANF) were studied in primary cultures of rat cardiac myocytes. Cultures were established from neonatal rat atria or ventricles, and were maintained for 7-14 days in complete serum free medium. The cultures contained high and constant levels of ANF-(1-126), the known storage form of the hormone in vivo. The cultures also secreted ANF-(1-126), instead of the known circulating form of the hormone, ANF-(99-126). However, the inclusion of the glucocorticoids dexamethasone or hydrocortisone in the culture medium increased the levels of ir-ANF contained and secreted by the cultures, and caused both atrial and ventricular cultures to secrete principally ANF-(99-126) instead of ANF-(1-126). The secreted peptide was shown to be authentic ANF-(99-126) by chromatographic, amino acid composition and radiosequence analysis, thus confirming that the cultures were accurately processing ANF to the in vivo circulating form in the presence of glucocorticoids. Glucocorticoids also caused an increase in size and clustering of atrial myocytes as determined by immunocytochemical analysis, but the morphological effects could be dissociated from the stimulation of ANF-(99-126) secretion by manipulating the timing of glucocorticoid exposure. The location of ANF-(99-126) formation was investigated using biosynthetically labeled 35 S-Cys-ANF-(1-126) in conjunction with actively processing cultures

[Secretion of growth hormone in hyperthyroidism].

Science.gov (United States)

Hervás, F; Morreale de Escobar, G; Escobar Del Rey, F; Pozuelo, V

1976-01-01

The authors studied growth hormone (GH) secretion in a group of adult controls and another group of hyperthyroid patients after stimulation with intravenous insulin-induced (0,1 IU/kg) hypoglycemia, aiming to clear out the problem of discrepancies in literature concerning GH secretion in hyperthyroidism. They concluded that in this syndrome, GH levels are significantly higher than those of controls. The GH releasing response is normal, though it could be expected to be decreased due to decreased pituitary GH contents as a result of permanent somatotrophic cell stimulation.

The Confidentiality of Medical Secrets of Patients by the Nursing Staff

Directory of Open Access Journals (Sweden)

Chalkias Theodoros

2010-01-01

Full Text Available In this article you will find a critical discussion about the significance of confidentiality of "medical secrets" (keeping the secrets of ill people by nurses. Special cases are mentioned regarding the need to keep, or reveal the secret.

Characterization of Pseudomonas aeruginosa chitinase, a gradually secreted protein.

Science.gov (United States)

Folders, J; Algra, J; Roelofs, M S; van Loon, L C; Tommassen, J; Bitter, W

2001-12-01

The gram-negative bacterium Pseudomonas aeruginosa secretes many proteins into its extracellular environment via the type I, II, and III secretion systems. In this study, a gene, chiC, coding for an extracellular chitinolytic enzyme, was identified. The chiC gene encodes a polypeptide of 483 amino acid residues, without a typical N-terminal signal sequence. Nevertheless, an N-terminal segment of 11 residues was found to be cleaved off in the secreted protein. The protein shows sequence similarity to the secreted chitinases ChiC of Serratia marcescens, ChiA of Vibrio harveyi, and ChiD of Bacillus circulans and consists of an activity domain and a chitin-binding domain, which are separated by a fibronectin type III domain. ChiC was able to bind and degrade colloidal chitin and was active on the artificial substrates carboxymethyl-chitin-Remazol Brilliant Violet and p-nitrophenyl-beta-D-N,N',N"-triacetylchitotriose, but not on p-nitrophenyl-beta-D-N-acetylglucosamine, indicating that it is an endochitinase. Expression of the chiC gene appears to be regulated by the quorum-sensing system of P. aeruginosa, since this gene was not expressed in a lasIR vsmI mutant. After overnight growth, the majority of the ChiC produced was found intracellularly, whereas only small amounts were detected in the culture medium. However, after several days, the cellular pool of ChiC was largely depleted, and the protein was found in the culture medium. This release could not be ascribed to cell lysis. Since ChiC did not appear to be secreted via any of the known secretion systems, a novel secretion pathway seems to be involved.

Probing into the Secret of the Chinese Air Force.

Science.gov (United States)

1983-11-30

Ri35 968 PROBING INTO THE SECRET OF THE CHINESE AIR FOREE(IJ 1/2 FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON RFB OH 9 38 NOV 83 FTD-ID(,RS)T 1088 3...FOREIGN TECHNOLOGY DIVISION. PROBING INTO THE SECRET OF THE CHINESE AIRFORCE CL1 Approved for public re.lease; distribution unlimited C=)X ~ EET...MICROFICHE NR: FTD-83-C-001469 PROBING INTO THE SECRET OF THE CHINESE AIRFORCE -" -English pages: 111 Source: Enclosure to IR 6 842 0088 83-Booklet

Analysis of an acyl-CoA binding protein in Aspergillus oryzae that undergoes unconventional secretion.

Science.gov (United States)

Kwon, Hee Su; Kawaguchi, Kouhei; Kikuma, Takashi; Takegawa, Kaoru; Kitamoto, Katsuhiko; Higuchi, Yujiro

2017-11-04

Acyl-CoA binding protein (ACBP) plays important roles in the metabolism of lipids in eukaryotic cells. In the industrially important filamentous fungus Aspergillus oryzae, although we have previously demonstrated that the A. oryzae ACBP (AoACBP) localizes to punctate structures and exhibits long-range motility, which is dependent on autophagy-related proteins, the physiological role of AoACBP remains elusive. Here, we describe identification and characterization of another ACBP from A. oryzae; we named this ACBP as AoAcb2 and accordingly renamed AoACBP as AoAcb1. The deduced amino acid sequence of AoAcb2 lacked a signal peptide. Phylogenetic analysis classified AoAcb2 into a clade that was same as the ACBP Acb1 of the model yeast Saccharomyces cerevisiae, but was different from that of AoAcb1. In contrast to punctate localization of AoAcb1, AoAcb2 was found to be dispersedly distributed in the cytoplasm, as was previously observed for the S. cerevisiae Acb1. Since we could not generate an Aoacb2 disruptant, we created an Aoacb2 conditional mutant that exhibited less growth under Aoacb2-repressed condition, suggesting that Aoacb2 is an essential gene for growth. Moreover, we observed that A. oryzae AoAcb2, but not A. oryzae AoAcb1, was secreted under carbon-starved condition, suggesting that AoAcb2 might be secreted via the unconventional protein secretion (UPS) pathway, just like S. cerevisiae Acb1. We also demonstrated that the unconventional secretion of AoAcb2 was dependent on the t-SNARE AoSso1, but was independent of the autophagy-related protein AoAtg1, suggesting that the unconventional secretion of AoAcb2, unlike that of S. cerevisiae Acb1, via the UPS pathway, is not regulated by the autophagy machinery. Thus, the filamentous fungus A. oryzae harbors two types of ACBPs, one of which appears to be essential for growth and undergoes unconventional secretion. Copyright © 2017 Elsevier Inc. All rights reserved.

Autocrine effect of Zn²⁺ on the glucose-stimulated insulin secretion.

Science.gov (United States)

Slepchenko, Kira G; Daniels, Nigel A; Guo, Aili; Li, Yang V

2015-09-01

It is well known that zinc (Zn(2+)) is required for the process of insulin biosynthesis and the maturation of insulin secretory granules in pancreatic beta (β)-cells, and that changes in Zn(2+) levels in the pancreas have been found to be associated with diabetes. Glucose-stimulation causes a rapid co-secretion of Zn(2+) and insulin with similar kinetics. However, we do not know whether Zn(2+) regulates insulin availability and secretion. Here we investigated the effect of Zn(2+) on glucose-stimulated insulin secretion (GSIS) in isolated mouse pancreatic islets. Whereas Zn(2+) alone (control) had no effect on the basal secretion of insulin, it significantly inhibited GSIS. The application of CaEDTA, by removing the secreted Zn(2+) from the extracellular milieu of the islets, resulted in significantly increased GSIS, suggesting an overall inhibitory role of secreted Zn(2+) on GSIS. The inhibitory action of Zn(2+) was mostly mediated through the activities of KATP/Ca(2+) channels. Furthermore, during brief paired-pulse glucose-stimulated Zn(2+) secretion (GSZS), Zn(2+) secretion following the second pulse was significantly attenuated, probably by the secreted endogenous Zn(2+) after the first pulse. Such an inhibition on Zn(2+) secretion following the second pulse was completely reversed by Zn(2+) chelation, suggesting a negative feedback mechanism, in which the initial glucose-stimulated Zn(2+) release inhibits subsequent Zn(2+) secretion, subsequently inhibiting insulin co-secretion as well. Taken together, these data suggest a negative feedback mechanism on GSZS and GSIS by Zn(2+) secreted from β-cells, and the co-secreted Zn(2+) may act as an autocrine inhibitory modulator.

Multi-group dynamic quantum secret sharing with single photons

Energy Technology Data Exchange (ETDEWEB)

Liu, Hongwei [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Ma, Haiqiang, E-mail: hqma@bupt.edu.cn [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Wei, Kejin [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Yang, Xiuqing [School of Science, Beijing Jiaotong University, Beijing 100044 (China); Qu, Wenxiu; Dou, Tianqi; Chen, Yitian; Li, Ruixue; Zhu, Wu [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

2016-07-15

In this letter, we propose a novel scheme for the realization of single-photon dynamic quantum secret sharing between a boss and three dynamic agent groups. In our system, the boss can not only choose one of these three groups to share the secret with, but also can share two sets of independent keys with two groups without redistribution. Furthermore, the security of communication is enhanced by using a control mode. Compared with previous schemes, our scheme is more flexible and will contribute to a practical application. - Highlights: • A multi-group dynamic quantum secret sharing with single photons scheme is proposed. • Any one of the groups can be chosen to share secret through controlling the polarization of photons. • Two sets of keys can be shared simultaneously without redistribution.

Hyperinsulinemia in the physiologic range is not superior to short-term fasting in suppressing insulin secretion in obese men.

Science.gov (United States)

Pincelli, A I; Brunani, A; Caumo, A; Scacchi, M; Pasqualinotto, L; Tibaldi, A; Dubini, A; Bonadonna, S; Cavagnini, F

2001-01-01

The negative-feedback control exerted by plasma insulin on beta-cell insulin release in normal-weight and obese subjects is still a matter of debate. Subjects submitted to a euglycemic insulin clamp undergo a suppression of insulin secretion that is due to both the infused insulin and the 2- to 3-hour fast during the procedure. We elected to elucidate the role of physiologic hyperinsulinemia per se in the insulin negative autofeedback in obese men. Ten men with massive uncomplicated obesity (age, 18 to 37 years; body mass index [BMI], 41 +/- 1.15 kg/m2) and 6 normal-weight healthy men (age, 22 to 30 years; BMI, 22 +/- 0.28 kg/m2) underwent 2 studies in random order: (1) a euglycemic-hyperinsulinemic glucose clamp with an insulin infusion rate of 1 mU/kg/min and (2) a control study with saline infusion. Serum C-peptide concentrations were significantly higher in obese versus control subjects at baseline (2.54 +/- 0.178 v 1.63 +/- 0.256 ng/mL, P < .05). Exogenous insulin infusion significantly suppressed serum C-peptide at steady state ([SS] last 30 minutes of insulin or saline infusion) in controls (mean of the last 4 measurements from 120 minutes to 150 minutes, 0.86 +/- 0.306 ng/mL, P < .05 vbaseline) but not in obese patients (2.03 +/- 0.26 ng/mL, nonsignificant [NS] v baseline). During the saline infusion studies, C-peptide levels slightly and similarly declined over time in both groups (2.71 +/- 0.350 at baseline v 2.31 +/- 0.300 ng/mL at SS in obese patients, NS, and 1.96 +/- 0.189 v 1.62 +/- 0.150 ng/mL in controls, NS). This study shows that in obese men hyperinsulinemia within the postprandial range is not superior to a 2.5-hour fast for the suppression of beta-cell activity, suggesting an impairment of the insulin negative autofeedback in this clinical condition.

31 CFR Appendix D to Subpart A of... - United States Secret Service

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false United States Secret Service D...—United States Secret Service 1. In general. This appendix applies to the United States Secret Service. 2. Public reading room. The United States Secret Service will provide a room on an ad hoc basis when...

psycho-social correlates of students' involvement in secret cults

African Journals Online (AJOL)

PROF EKWUEME

as constituting general threat to peace in institutions of higher learning. (Fawole ... involvement in secret cults, and to investigate if peer group do influence students involvement in secret cults. .... be of benefit to students, teachers, parents,.

[Dynamics of hormone secretion during chronic emotional stress].

Science.gov (United States)

Amiragova, M G; Kovalev, S V; Svirskaia, R I

1979-05-01

Study of spontaneous secretion of corticosteroids and thyroid hormones and the direct hormonal response to stress revealed the pathogenic effect of chronic combined emotional stress upon the hormonal function of adrenal glands. The hippocampus takes part in formation of the emotional tension in response to stress stimulus and of the following hormonal secretion.

Preliminary observation of genital secretions, growth rate and ...

African Journals Online (AJOL)

Cane rats are large terrestial rodents which have the potential to increase animal protein intake. There is paucity of information on the genital secretions and growth rate of caged cane rats. This study observed the genital secretions, growth rate, feeds, feeding and the behaviour of caged cane rats. When animals adjusted to ...

Surfactant secretion and clearance in the newborn

International Nuclear Information System (INIS)

Stevens, P.A.; Wright, J.R.; Clements, J.A.

1989-01-01

Pregnant rabbits (30 days) were injected intravenously with [3H]choline 8 h before delivery. The fetuses were delivered, and lung lavage and lamellar body phospholipids (PL) were analyzed. Some newborns also received radioactively labeled surfactant intratracheally on delivery and were permitted to breathe. With time, intratracheal label decreased in lavage and appeared in the lamellar body fraction, and intravenous label accumulated in both pools. Using a tracer analysis for non-steady state, we calculated surfactant secretion and clearance rates for the newborn period. Before birth, both rates rose slightly from 1.8 micrograms PL.g body wt-1.h-1 at 6 h before birth to 7.3 at birth. Immediately after birth, secretion rate rose to 37.7 micrograms PL.g body wt-1.h-1. Between 1.5 and 2 h after birth it fell to a minimum of 1.8 micrograms PL.g body wt-1.h-1 and then rose slowly to 6.0 at 12 h. After birth, clearance rate increased less than secretion rate (maximum 24.7 micrograms PL.g body wt-1.h-1 shortly after birth) then followed the same pattern but did not balance secretion rate in the 1st day

Bidirectional regulation of bakuchiol, an estrogenic-like compound, on catecholamine secretion

International Nuclear Information System (INIS)

Mao, Haoping; Wang, Hong; Ma, Shangwei; Xu, Yantong; Zhang, Han; Wang, Yuefei; Niu, Zichang; Fan, Guanwei; Zhu, Yan; Gao, Xiu Mei

2014-01-01

Excess or deficiency of catecholamine (CA) secretion was related with several diseases. Recently, estrogen and phytoestrogens were reported to regulate the activity of CA system. Bakuchiol is a phytoestrogen isolated from the seeds of Psoralea corylifolia L. (Leguminosae) which has been used in Traditional Chinese medicine as a tonic or aphrodisiac. In the present study, bovine adrenal medullary cells were employed to investigate the effects and mechanisms of bakuchiol on the regulation of CA secretion. Further, its anti-depressant like and anti-stress effects were evaluated by using behavioral despair and chronic immobilization stress models. Our results indicated that bakuchiol showed bidirectional regulation on CA secretion. It stimulated basal CA secretion in a concentration dependent manner (p + (p + induced CA secretion was related with reduction of intracellular calcium rise. In vivo experiments, we found that bakuchiol significantly reduced immobilization time in behavioral despair mouse (p < 0.05 or 0.01), and plasma epinephrine (E) and norepinephrine (NE) levels in chronic immobilization stress (p < 0.05). Overall, these results present a bidirectional regulation of bakuchiol on CA secretion which indicated that bakuchiol may exert anti-stress and the potential anti-depressant-like effects. - Highlights: • Bakuchiol stimulated basal catecholamine secretion. • Bakuchiol inhibited various secretagogues induced catecholamine secretion. • Bakuchiol may have anti-stress and the potential anti-depression-like effects

Aerosol Optical Properties at the Lulin Atmospheric Background Station in Taiwan and the Influences of Long-Range Transport of Air Pollutants

Science.gov (United States)

Hsiao, Ta-Chih; Chen, Wei-Nai; Ye, Wei-Cheng; Lin, Neng-Huei; Tsay, Si-Chee; Lin, Tang-Huang; Lee, Chung-Te; Chuang, Ming-Tung; Pantina, Peter; Wang, Sheng-Hsiang

2016-01-01

The Lulin Atmospheric Background Station (LABS, 23.47 deg. N 120.87 deg. E, 2862 m ASL) in Central Taiwan was constructed in 2006 and is the only high-altitude background station in the western Pacific region for studying the influence of continental outflow. In this study, extensive optical properties of aerosols, including the aerosol light scattering coefficient [Sigma(sub s)] and light absorption coefficient [Sigma(sub a)], were collected from 2013 to 2014. The intensive optical properties, including mass scattering efficiency [Sigma(sub s)], mass absorption efficiency [Sigma(sub a)] single scattering albedo (Omega), scattering Angstrom exponent (A), and backscattering fraction (b), were determined and investigated, and the distinct seasonal cycle was observed. The value of [Alpha(sub a)] began to increase in January and reached a maximum in April; the mean in spring was 5.89 m(exp. 2) g(exp. -1) with a standard deviation (SD) of 4.54 m(exp. 2) g(exp. -1) and a 4.48 m(exp. 2) g(exp. -1) interquartile range (IQR: 2.95-7.43 m(exp. 2) g(exp. -1). The trend was similar in [Sigma(sub a)], with a maximum in March and a monthly mean of 0.84 m(exp. 2) g(exp. -1). The peak values of Omega (Mean = 0.92, SD = 0.03, IQR: 0.90 - 0.93) and A (Mean = 2.22, SD = 0.61, IQR: 2.12 = 2.47) occurred in autumn. These annual patterns of optical properties were associated with different long-range transport patterns of air pollutants such as biomass burning (BB) aerosol in spring and potential anthropogenic emissions in autumn. The optical measurements performed at LABS during spring in 2013 were compared with those simultaneously performed at the Doi Ang Kang Meteorology Station, Chiang Mai Province, Thailand (DAK, 19.93 deg. N, 99.05 deg. E, 1536 m a.s.l.), which is located in the Southeast Asia BB source region. Furthermore, the relationships among [Sigma(sub s)], [Sigma(sub a)], and (b) were used to characterize the potential aerosol types transported to LABS during different

Aerosol optical properties at the Lulin Atmospheric Background Station in Taiwan and the influences of long-range transport of air pollutants

Science.gov (United States)

Hsiao, Ta-Chih; Chen, Wei-Nai; Ye, Wei-Cheng; Lin, Neng-Huei; Tsay, Si-Chee; Lin, Tang-Huang; Lee, Chung-Te; Chuang, Ming-Tung; Pantina, Peter; Wang, Sheng-Hsiang

2017-02-01

The Lulin Atmospheric Background Station (LABS, 23.47°N 120.87°E, 2862 m ASL) in Central Taiwan was constructed in 2006 and is the only high-altitude background station in the western Pacific region for studying the influence of continental outflow. In this study, extensive optical properties of aerosols, including the aerosol light scattering coefficient (σs) and light absorption coefficient (σa), were collected from 2013 to 2014. The intensive optical properties, including mass scattering efficiency (αs), mass absorption efficiency (αa), single scattering albedo (ω), scattering Ångstrӧm exponent (Å), and backscattering fraction (b), were determined and investigated, and the distinct seasonal cycle was observed. The value of αs began to increase in January and reached a maximum in April; the mean in spring was 5.89 m2 g-1 with a standard deviation (SD) of 4.54 m2 g-1 and a 4.48 m2 g-1 interquartile range (IQR: 2.95-7.43 m2 g-1). The trend was similar in αa, with a maximum in March and a monthly mean of 0.84 m2 g-1. The peak values of ω (Mean = 0.92, SD = 0.03, IQR: 0.90-0.93) and Å (Mean = 2.22, SD = 0.61, IQR: 2.12-2.47) occurred in autumn. These annual patterns of optical properties were associated with different long-range transport patterns of air pollutants such as biomass burning (BB) aerosol in spring and potential anthropogenic emissions in autumn. The optical measurements performed at LABS during spring in 2013 were compared with those simultaneously performed at the Doi Ang Kang Meteorology Station, Chiang Mai Province, Thailand (DAK, 19.93°N, 99.05°E, 1536 m a.s.l.), which is located in the Southeast Asia BB source region. Furthermore, the relationships among αs, αa, and b were used to characterize the potential aerosol types transported to LABS during different seasons, and the data were inspected according to the HYSPLIT 5-day backward trajectories, which differentiate between different regions of air mass origin.

Secret Sharing of a Quantum State.

Science.gov (United States)

Lu, He; Zhang, Zhen; Chen, Luo-Kan; Li, Zheng-Da; Liu, Chang; Li, Li; Liu, Nai-Le; Ma, Xiongfeng; Chen, Yu-Ao; Pan, Jian-Wei

2016-07-15

Secret sharing of a quantum state, or quantum secret sharing, in which a dealer wants to share a certain amount of quantum information with a few players, has wide applications in quantum information. The critical criterion in a threshold secret sharing scheme is confidentiality: with less than the designated number of players, no information can be recovered. Furthermore, in a quantum scenario, one additional critical criterion exists: the capability of sharing entangled and unknown quantum information. Here, by employing a six-photon entangled state, we demonstrate a quantum threshold scheme, where the shared quantum secrecy can be efficiently reconstructed with a state fidelity as high as 93%. By observing that any one or two parties cannot recover the secrecy, we show that our scheme meets the confidentiality criterion. Meanwhile, we also demonstrate that entangled quantum information can be shared and recovered via our setting, which shows that our implemented scheme is fully quantum. Moreover, our experimental setup can be treated as a decoding circuit of the five-qubit quantum error-correcting code with two erasure errors.

KATP channels are not essential for pressure-dependent control of renin secretion

DEFF Research Database (Denmark)

Jensen, B L; Gambaryan, S; Scholz, H

1998-01-01

(IPRK). Cromakalim (0.1-10 muM) stimulated basal renin secretion up to threefold and caused vasorelaxation in the IPRK. Both effects of cromakalim were attenuated by glibenclamide. Cromakalim stimulated renin secretion from isolated juxtaglomerular (JG) cells and from microdissected afferent arterioles......This study aimed to investigate the functional role of ATP-sensitive K+ (KATP) channels in the control of renin secretion by renal perfusion pressure. We studied the effect of openers and blockers of KATP-channels on basal- and low-pressure-induced renin secretion from isolated perfused rat kidneys......, all of which suggests that KATP channel openers stimulate renin secretion at the level of JG cells. A decrease in the perfusion pressure from 13.3 to 9.33 kPa (100 mmHg to 70 mmHg) increased renin secretion twofold, and cromakalim further increased renin secretion. At 5.33 kPa (40 mmHg) renin...

Type VI secretion system.

Science.gov (United States)

Salomon, Dor; Orth, Kim

2015-03-30

Bacteria employ a variety of tools to survive in a competitive environment. Salomon and Orth describe one such tool-the Type 6 Secretion Systems used by bacteria to deliver a variety of toxins into competing cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Diversity-Multiplexing Tradeoff of Secret-Key Agreement over Multiple-Antenna Channels

KAUST Repository

Zorgui, Marwen; Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

2015-01-01

We study the problem of secret-key agreement between two legitimate parties, Alice and Bob, in presence an of eavesdropper Eve. There is a public channel with unlimited capacity that is available to the legitimate parties and is also observed by Eve. Our focus is on Rayleigh fading quasi-static channels. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge of their channels. We study the system in the high-power regime. First, we define the secret-key diversity gain and the secret-key multiplexing gain. Second, we establish the secret-key diversity multiplexing tradeoff (DMT) under no channel state information (CSI) at the transmitter (CSI-T). The eavesdropper is shown to “steal” only transmit antennas. We show that, likewise the DMT without secrecy constraint, the secret-key DMT is the same either with or without full channel state information at the transmitter. This insensitivity of secret-key DMT toward CSI-T features a fundamental difference between secret-key agreement and the wiretap channel, in which secret DMT depends heavily on CSI-T. Finally, we present several secret-key DMT-achieving schemes in case of full CSI-T. We argue that secret DMT-achieving schemes are also key DMT-achieving. Moreover, we show formally that artificial noise (AN), likewise zero-forcing (ZF), is DMT-achieving. We also show that the public feedback channel improves the outage performance without having any effect on the DMT.

The Diversity-Multiplexing Tradeoff of Secret-Key Agreement over Multiple-Antenna Channels

KAUST Repository

Zorgui, Marwen

2015-10-26

We study the problem of secret-key agreement between two legitimate parties, Alice and Bob, in presence an of eavesdropper Eve. There is a public channel with unlimited capacity that is available to the legitimate parties and is also observed by Eve. Our focus is on Rayleigh fading quasi-static channels. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge of their channels. We study the system in the high-power regime. First, we define the secret-key diversity gain and the secret-key multiplexing gain. Second, we establish the secret-key diversity multiplexing tradeoff (DMT) under no channel state information (CSI) at the transmitter (CSI-T). The eavesdropper is shown to “steal” only transmit antennas. We show that, likewise the DMT without secrecy constraint, the secret-key DMT is the same either with or without full channel state information at the transmitter. This insensitivity of secret-key DMT toward CSI-T features a fundamental difference between secret-key agreement and the wiretap channel, in which secret DMT depends heavily on CSI-T. Finally, we present several secret-key DMT-achieving schemes in case of full CSI-T. We argue that secret DMT-achieving schemes are also key DMT-achieving. Moreover, we show formally that artificial noise (AN), likewise zero-forcing (ZF), is DMT-achieving. We also show that the public feedback channel improves the outage performance without having any effect on the DMT.

Production, secretion, and stability of human secreted alkaline phosphatase in tobacco NT1 cell suspension cultures.

Science.gov (United States)

Becerra-Arteaga, Alejandro; Mason, Hugh S; Shuler, Michael L

2006-01-01

Tobacco NT1 cell suspension cultures secreting active human secreted alkaline phosphatase (SEAP) were generated for the first time as a model system to study recombinant protein production, secretion, and stability in plant cell cultures. The SEAP gene encodes a secreted form of the human placental alkaline phosphatase (PLAP). During batch culture, the highest level of active SEAP in the culture medium (0.4 U/mL, corresponding to approximately 27 mg/L) was observed at the end of the exponential growth phase. Although the level of active SEAP decreased during the stationary phase, the activity loss did not appear to be due to SEAP degradation (based on Western blots) but due to SEAP denaturation. The protein-stabilizing agents polyvinylpirrolidone (PVP) and bacitracin were added extracellularly to test for their ability to reduce the loss of SEAP activity during the stationary phase. Bacitracin (100 mg/L) was the most effective treatment at sustaining activity levels for up to 17 days post-subculture. Commercially available human placental alkaline phosphatase (PLAP) was used to probe the mechanism of SEAP deactivation. Experiments with PLAP in sterile and conditioned medium corroborated the denaturation of SEAP by factors generated by cell growth and not due to simple proteolysis. We also show for the first time that the factors promoting activity loss are heat labile at 95 degrees C but not at 70 degrees C, and they are not inactivated after a 5 day incubation period under normal culture conditions (27 degrees C). In addition, there were no significant changes in pH or redox potential when comparing sterile and cell-free conditioned medium during PLAP incubation, indicating that these factors were unimportant.

FluG affects secretion in colonies of Aspergillus niger.

Science.gov (United States)

Wang, Fengfeng; Krijgsheld, Pauline; Hulsman, Marc; de Bekker, Charissa; Müller, Wally H; Reinders, Marcel; de Vries, Ronald P; Wösten, Han A B

2015-01-01

Colonies of Aspergillus niger are characterized by zonal heterogeneity in growth, sporulation, gene expression and secretion. For instance, the glucoamylase gene glaA is more highly expressed at the periphery of colonies when compared to the center. As a consequence, its encoded protein GlaA is mainly secreted at the outer part of the colony. Here, multiple copies of amyR were introduced in A. niger. Most transformants over-expressing this regulatory gene of amylolytic genes still displayed heterogeneous glaA expression and GlaA secretion. However, heterogeneity was abolished in transformant UU-A001.13 by expressing glaA and secreting GlaA throughout the mycelium. Sequencing the genome of UU-A001.13 revealed that transformation had been accompanied by deletion of part of the fluG gene and disrupting its 3' end by integration of a transformation vector. Inactivation of fluG in the wild-type background of A. niger also resulted in breakdown of starch under the whole colony. Asexual development of the ∆fluG strain was not affected, unlike what was previously shown in Aspergillus nidulans. Genes encoding proteins with a signal sequence for secretion, including part of the amylolytic genes, were more often downregulated in the central zone of maltose-grown ∆fluG colonies and upregulated in the intermediate part and periphery when compared to the wild-type. Together, these data indicate that FluG of A. niger is a repressor of secretion.

32 CFR 9.9 - Protection of State secrets.

Science.gov (United States)

2010-07-01

... FOR TRIALS BY MILITARY COMMISSIONS OF CERTAIN NON-UNITED STATES CITIZENS IN THE WAR AGAINST TERRORISM § 9.9 Protection of State secrets. Nothing in this part shall be construed to authorize disclosure of... 32 National Defense 1 2010-07-01 2010-07-01 false Protection of State secrets. 9.9 Section 9.9...

Insulin secretion and action in North Indian women during pregnancy.

Science.gov (United States)

Arora, G P; Almgren, P; Thaman, R G; Pal, A; Groop, L; Vaag, A; Prasad, R B; Brøns, C

2017-10-01

The relative roles(s) of impaired insulin secretion vs. insulin resistance in the development of gestational diabetes mellitus depend upon multiple risk factors and diagnostic criteria. Here, we explored their relative contribution to gestational diabetes as defined by the WHO 1999 (GDM1999) and adapted WHO 2013 (GDM2013) criteria, excluding the 1-h glucose value, in a high-risk Indian population from Punjab. Insulin secretion (HOMA2-B) and insulin action (HOMA2-IR) were assessed in 4665 Indian women with or without gestational diabetes defined by the GDM1999 or adapted GDM2013 criteria. Gestational diabetes defined using both criteria was associated with decreased insulin secretion compared with pregnant women with normal glucose tolerance. Women with gestational diabetes defined by the adapted GDM2013, but not GDM1999 criteria, were more insulin resistant than pregnant women with normal glucose tolerance, and furthermore displayed lower insulin secretion than GDM1999 women. Urban habitat, illiteracy, high age and low BMI were independently associated with reduced insulin secretion, whereas Sikh religion, increasing age and BMI, as well as a family history of diabetes were independently associated with increased insulin resistance. Gestational diabetes risk factors influence insulin secretion and action in North Indian women in a differential manner. Gestational diabetes classified using the adapted GDM2013 compared with GDM1999 criteria is associated with more severe impairments of insulin secretion and action. © 2017 Diabetes UK.

A secreted factor represses cell proliferation in Dictyostelium.

Science.gov (United States)

Brock, Debra A; Gomer, Richard H

2005-10-01

Many cells appear to secrete factors called chalones that limit their proliferation, but in most cases the factors have not been identified. We found that growing Dictyostelium cells secrete a 60 kDa protein called AprA for autocrine proliferation repressor. AprA has similarity to putative bacterial proteins of unknown function. Compared with wild-type cells, aprA-null cells proliferate faster, while AprA overexpressing cells proliferate slower. Growing wild-type cells secrete a factor that inhibits the proliferation of wild-type and aprA- cells; this activity is not secreted by aprA- cells. AprA purified by immunoprecipitation also slows the proliferation of wild-type and aprA- cells. Compared with wild type, there is a higher percentage of multinucleate cells in the aprA- population, and when starved, aprA- cells form abnormal structures that contain fewer spores. AprA may thus decrease the number of multinucleate cells and increase spore production. Together, the data suggest that AprA functions as part of a Dictyostelium chalone.

Testosterone-secreting adrenal adenoma in a peripubertal girl

International Nuclear Information System (INIS)

Kamilaris, T.C.; DeBold, C.R.; Manolas, K.J.; Hoursanidis, A.; Panageas, S.; Yiannatos, J.

1987-01-01

A 15-year-old girl who presented with primary amenorrhea and virilization had an adrenocortical adenoma that secreted predominantly testosterone. To the authors' knowledge, she is the first peripubertal and second youngest patient with a testosterone-secreting adrenal tumor described. Serum dehydroepiandrosterone sulfate and urinary 17-ketosteroid an 17-hydroxycorticosteroid levels were normal. A tumor was located by a computed tomographic (CT) scan and by uptake of 6-β-[ 75 Se] selenomethylnorcholesterol. Microscopic examination of the tumor showed typical features of an adrenocortical adenoma with no histologic features characteristic of Leydig cells. Postoperatively, her hirsutism regressed, she rapidly went through puberty, and regular monthly menstruation started four months later. Finding the source of testosterone in a virilized patient can be difficult. Eleven of the 14 previously described patients with testosterone-secreting adrenal tumors initially underwent misdirected surgery on the ovaries. Review of these cases revealed that results of hormone stimulation and suppression tests are unreliable and that these tumors are usually large. Therefore, CT scanning of the adrenal glands is recommended in all patients suspected of having a testosterone-secreting tumor

Testosterone-secreting adrenal adenoma in a peripubertal girl

Energy Technology Data Exchange (ETDEWEB)

Kamilaris, T.C.; DeBold, C.R.; Manolas, K.J.; Hoursanidis, A.; Panageas, S.; Yiannatos, J.

1987-11-13

A 15-year-old girl who presented with primary amenorrhea and virilization had an adrenocortical adenoma that secreted predominantly testosterone. To the authors' knowledge, she is the first peripubertal and second youngest patient with a testosterone-secreting adrenal tumor described. Serum dehydroepiandrosterone sulfate and urinary 17-ketosteroid an 17-hydroxycorticosteroid levels were normal. A tumor was located by a computed tomographic (CT) scan and by uptake of 6-..beta..-(/sup 75/Se) selenomethylnorcholesterol. Microscopic examination of the tumor showed typical features of an adrenocortical adenoma with no histologic features characteristic of Leydig cells. Postoperatively, her hirsutism regressed, she rapidly went through puberty, and regular monthly menstruation started four months later. Finding the source of testosterone in a virilized patient can be difficult. Eleven of the 14 previously described patients with testosterone-secreting adrenal tumors initially underwent misdirected surgery on the ovaries. Review of these cases revealed that results of hormone stimulation and suppression tests are unreliable and that these tumors are usually large. Therefore, CT scanning of the adrenal glands is recommended in all patients suspected of having a testosterone-secreting tumor.

Central effects of humanin on hepatic triglyceride secretion.

Science.gov (United States)

Gong, Zhenwei; Su, Kai; Cui, Lingguang; Tas, Emir; Zhang, Ting; Dong, H Henry; Yakar, Shoshana; Muzumdar, Radhika H

2015-08-01

Humanin (HN) is an endogenous mitochondria-associated peptide that has been shown to protect against various Alzheimer's disease-associated insults, myocardial ischemia-reperfusion injury, and reactive oxygen species-induced cell death. We have shown previously that HN improves whole body glucose homeostasis by improving insulin sensitivity and increasing glucose-stimulated insulin secretion (GSIS) from the β-cells. Here, we report that intraperitoneal treatment with one of HN analogs, HNG, decreases body weight gain, visceral fat, and hepatic triglyceride (TG) accumulation in high-fat diet-fed mice. The decrease in hepatic TG accumulation is due to increased activity of hepatic microsomal triglyceride transfer protein (MTTP) and increased hepatic TG secretion. Both intravenous (iv) and intracerebroventricular (icv) infusion of HNG acutely increase TG secretion from the liver. Vagotomy blocks the effect on both iv and icv HNG on TG secretion, suggesting that the effects of HNG on hepatic TG flux are centrally mediated. Our data suggest that HN is a new player in central regulation of peripheral lipid metabolism. Copyright © 2015 the American Physiological Society.

Inhibition of type VI secretion by an anti-TssM llama nanobody.

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Van Son Nguyen

Full Text Available The type VI secretion system (T6SS is a secretion pathway widespread in Gram-negative bacteria that targets toxins in both prokaryotic and eukaryotic cells. Although most T6SSs identified so far are involved in inter-bacterial competition, a few are directly required for full virulence of pathogens. The T6SS comprises 13 core proteins that assemble a large complex structurally and functionally similar to a phage contractile tail structure anchored to the cell envelope by a trans-membrane spanning stator. The central part of this stator, TssM, is a 1129-amino-acid protein anchored in the inner membrane that binds to the TssJ outer membrane lipoprotein. In this study, we have raised camelid antibodies against the purified TssM periplasmic domain. We report the crystal structure of two specific nanobodies that bind to TssM in the nanomolar range. Interestingly, the most potent nanobody, nb25, competes with the TssJ lipoprotein for TssM binding in vitro suggesting that TssJ and the nb25 CDR3 loop share the same TssM binding site or causes a steric hindrance preventing TssM-TssJ complex formation. Indeed, periplasmic production of the nanobodies displacing the TssM-TssJ interaction inhibits the T6SS function in vivo. This study illustrates the power of nanobodies to specifically target and inhibit bacterial secretion systems.

Trade Secret Law and Information Systems: Can Your Students Keep a Secret?

Science.gov (United States)

Willey, Lorrie; Ford, Janet C.; White, Barbara Jo; Clapper, Danial L.

2011-01-01

The impact of intellectual property (IP) law on information systems (IS) professionals in business cannot be overstated. The IS 2010 model curriculum guidelines for undergraduate IS programs stress the importance of information security and knowledge about IP. While copyright and patents are the most well-known types of IP, another, trade secrets,…

Cryptanalysis of quantum secret sharing based on GHZ states

International Nuclear Information System (INIS)

Liu Xiaofen; Pan Rijing

2011-01-01

In a recent paper (Hwang et al 2011 Phys. Scr. 83 045004), a subtle quantum secret sharing (QSS) protocol was proposed. One major advantage of this protocol is its high efficiency; that is, it is more efficient than other QSS protocols using the Greenberger-Horne-Zeilinger states. However, we analyzed the security of this protocol and found that it is insecure for one agent who may deduce half of the information about the deal's secret directly just by his/her piece of secret. Finally, a feasible improvement of this QSS protocol is put forward.

Acidity enhances the effectiveness of active chemical defensive secretions of sea hares, Aplysia californica, against spiny lobsters, Panulirus interruptus.

Science.gov (United States)

Shabani, Shkelzen; Yaldiz, Seymanur; Vu, Luan; Derby, Charles D

2007-12-01

Sea hares such as Aplysia californica, gastropod molluscs lacking a protective shell, can release a purple cloud of chemicals when vigorously attacked by predators. This active chemical defense is composed of two glandular secretions, ink and opaline, both of which contain an array of compounds. This secretion defends sea hares against predators such as California spiny lobsters Panulirus interruptus via multiple mechanisms, one of which is phagomimicry, in which secretions containing feeding chemicals attract and distract predators toward the secretion and away from the sea hare. We show here that ink and opaline are highly acidic, both having a pH of approximately 5. We examined if the acidity of ink and opaline affects their phagomimetic properties. We tested behavioral and electrophysiological responses of chemoreceptor neurons in the olfactory and gustatory organs of P. interruptus, to ink and opaline of A. californica within their natural range of pH values, from approximately 5 to 8. Both behavioral and electrophysiological responses to ink and opaline were enhanced at low pH, and low pH alone accounted for most of this effect. Our data suggest that acidity enhances the phagomimetic chemical defense of sea hares.

BIOCHEMISTRY CHARACTERIZATION OF EXCRETION / SECRETION PRODUCT OF Cochliomyia hominivorax LARVAE (DIPTERA : CALLIPHORIDAE

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Denise Gonçalves Teixeira

2016-10-01

Full Text Available The species Cochliomyia hominivorax, also known as screwworm fly, is an obligate parasite of warm- blooded animals and its geographic range extends thoughout South America, except Chile. This fly causes significant economic losses and has great importance in Brazil. Few studies have focused on the excretion and secretion products of this species, and this research aimed to study the enzymes present in the secretion and excretion (E/S products of the three larval instars of C. hominivorax. The E/S profile of proteins was obtained by polyacrylamide gel electrophoresis and proteolytic activity was analyzed using gelatin, azocasein and Na-benzoyl-arginine-nitroanilide as substrates.  In E/S products of the three instars, proteins were detected with an apparent molecular weight ranging between 116 and 20 kDa. In the azocasein assay, at different pH ranges, the major proteolytic activity occurred at pH 7.5 for all larval instars. Assays were performed using the same substrates   in which the samples were treated with the inhibitors Benzamidine, Pepstatin A, 4-(2-Aminoethyl benzenesulfonyl fluoride hydrochloride (AEBSF, N-α-tosyl-L-lysine chloromethyl ketone (TLCK, N-α- tosyl-L-phenylalanine chloromethyl ketone (TPCK, Ethylenediamine tetraacetic acid (EDTA, and Leupeptin-trans-Epoxysuccinyl-leucylamido(4-guanidino butane (E-64. Proteinases present in the E/S product of first larvae instar are mostly serine trypsin and chymotrypsin proteases, whereas for second and third instars serine proteases and aspartyl proteases were predominantly observed. Biochemical characterization of E/S products of all larval stages of C. hominivorax helps to improve the understanding of the physiology and the interaction of this parasite with host tissues. Keywords: Enzyme; fly; myiasis; parasites.

14 CFR 121.550 - Secret Service Agents: Admission to flight deck.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Secret Service Agents: Admission to flight... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.550 Secret Service Agents: Admission to flight deck. Whenever an Agent of the Secret Service who is assigned the duty...

Inappropriate Antidiuretic Hormone Secretion

African Journals Online (AJOL)

1974-06-08

Jun 8, 1974 ... with Addison's disease, diarrhoea or salt-losing nephritis. (asymptomatic hyponatraemia).~ Schwartz et al.3 stud;ed two patients with anaplastic bronchus carcinoma and hyponatraemia in 1957, and they suggested that there was an inappropriate secretion of antidiuretic hormone (ADH). It is now well ...

Comment on "Dynamic quantum secret sharing"

Science.gov (United States)

Liao, Ci-Hong; Yang, Chun-Wei; Hwang, Tzonelish

2013-10-01

Hsu et al. (Quantum Inf Process 12:331-344,2013) proposed a dynamic quantum secret sharing (DQSS) protocol using the entanglement swapping of Bell states for an agent to easily join (or leave) the system. In 2013, Wang and Li (Quantum Inf Process 12(5):1991-1997, 2013) proposed a collusion attack on Hsu et al.'s DQSS protocol. Nevertheless, this study points out a new security issue on Hsu et al.'s DQSS protocol regarding to the honesty of a revoked agent. Without considering this issue, the DQSS protocol could be failed to provide secret sharing function.

Maturation processes and structures of small secreted peptides in plants

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Ryo eTabata

2014-07-01

Full Text Available In the past decade, small secreted peptides have proven to be essential for various aspects of plant growth and development, including the maintenance of certain stem cell populations. Most small secreted peptides identified in plants to date are recognised by membrane-localized receptor kinases, the largest family of receptor proteins in the plant genome. This peptide-receptor interaction is essential for initiating intracellular signalling cascades. Small secreted peptides often undergo post-translational modifications and proteolytic processing to generate the mature peptides. Recent studies suggest that, in contrast to the situation in mammals, the proteolytic processing of plant peptides involves a number of complex steps. Furthermore, NMR-based structural analysis demonstrated that post-translational modifications induce the conformational changes needed for full activity. In this mini review, we summarise recent advances in our understanding of how small secreted peptides are modified and processed into biologically active peptides and describe the mature structures of small secreted peptides in plants.

Seasonal prolactin secretion and its role in seasonal reproduction: a review.

Science.gov (United States)

Curlewis, J D

1992-01-01

The majority of seasonally breeding mammals show a seasonal pattern of prolactin secretion with peak concentrations in spring or summer and a nadir in autumn or winter. Photoperiod influences prolactin secretion via its effects on the secretion of the pineal hormone melatonin. Preliminary evidence suggests that the effects of melatonin on both prolactin and gonadotrophin secretion are via a common target area, possibly within the anterior hypothalamus, and that differences in response to photoperiod may be due to differences in the processing and/or interpretation of the melatonin signal. In contrast to seasonal gonadotrophin secretion, the seasonal changes in prolactin are not due to changes in the sensitivity of a feedback loop and so must be due to direct effects on the hypothalamic pathways that control prolactin secretion. Little else can be said with confidence about the neuroendocrine mechanisms that lead to the seasonal changes in prolactin secretion. Dopamine and noradrenaline turnover in the arcuate nucleus and median eminence decrease under short daylength. If catecholamine turnover in these structures is positively correlated with catecholamine concentrations in the long or short hypophysial portal vessels, it is unlikely that the decrease in prolactin concentration in winter is due to the effects of increased concentrations of dopamine or noradrenaline in the portal vessels. There is, however, evidence for increased pituitary sensitivity to dopamine under short daylength, so increased dopamine concentrations may not be required for suppression of prolactin secretion at this time. In addition to the diminished secretion of prolactin under short daylength, rate of prolactin synthesis and pituitary content of prolactin also decline although the mechanisms that regulate these changes are poorly understood. Although all seasonal breeders show a seasonal change in prolactin secretion, there are continuously breeding species in which prolactin secretion is

Ability of multicellular salt glands in Tamarix species to secrete Na+ and K+ selectively.

Science.gov (United States)

Ma, Haiyan; Tian, Changyan; Feng, Gu; Yuan, Junfeng

2011-03-01

The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands. Using a hydroponic culture system, the secretion and accumulation of Na(+) and K(+) in Tamarix ramosissima and T. laxa under different salt stresses (NaCl, KCl and NaCl+KCl) were studied. Additionally, the effects of salt gland inhibitors (orthovanadate, Ba(2+), ouabain, tetraethylammonium (TEA) and verapamil) on Na(+) and K(+) secretion and accumulation were examined. Treatment with NaCl (at 0-200 mmol L(-1) levels) significantly increased Na(+) secretion, whereas KCl treatment (at 0-200 mmol L(-1) levels) significantly increased K(+) secretion. The ratio of secretion to accumulation of Na(+) was higher than that of K(+). The changes in Na(+) and K(+) secretion differed after adding different ions into the single-salt solutions. Addition of NaCl to the KCl solution (at 100 mmol L(-1) level, respectively) led to a significant decrease in K(+) secretion rate, whereas addition of KCl to the NaCl solution (at 100 mmol L(-1) level, respectively) had little impact on the Na(+) secretion rate. These results indicated that Na+ secretion in Tamarix was highly selective. In addition, Na(+) secretion was significantly inhibited by orthovanadate, ouabain, TEA and verapamil, and K(+) secretion was significantly inhibited by ouabain, TEA and verapamil. The different impacts of orthovanadate on Na(+) and K(+) secretion might be the primary cause for the different Na(+) and K(+) secretion abilities of multicellular salt glands in Tamarix.

Role of taurine on acid secretion in the rat stomach

Science.gov (United States)

2011-01-01

Background Taurine has chemical structure similar to an inhibitory neurotransmitter, γ-aminobutyric acid (GABA). Previous studies on GABA in the stomach suggest GABAergic neuron is involved in acid secretion, but the effects of taurine are poor understood. Methods The effects of taurine on acid secretion, signal transduction, and localization of taurinergic neurons were determined in the rat stomach using everted whole stomach, RIA kit and immunohistochemical methods. Results We used antibodies against taurine-synthesizing enzyme, cysteine sulfuric acid decarboxylase (CSAD), and taurine. CSAD- and taurine-positive cells were found in the muscle and mucosal layers. Distributions of CSAD- and taurine-positive cells in both mucosal and muscle layers were heterogeneous in the stomach. Taurine at 10-9~10-4 M induced acid secretion, and the maximum secretion was at 10-5 M, 1.6-fold higher than the spontaneous secretion. Taurine-induced acid secretion was completely inhibited by bicuculline and atropine but not by cimetidine, proglumide, or strychnine. Atropine and tetrodotoxin (TTX) completely inhibited the acid secretion induced by low concentrations of taurine and partially inhibited induced by high concentrations. Verapamil, a calcium blocker agent, inhibited acid output elicited by taurine. We assumed all Ca2+ channels involved in the response to these secretagogues were equally affected by verapamil. Intracellular cAMP (adenosine 3', 5'-monophosphat) in the stomach significantly increased with taurine treatment in a dose-dependent manner. High correlation (r=0.859, p taurine concentrations with cAMP was observed. Conclusions Our results demonstrated for the first time in taurine-induced acid secretion due to increase intracellular calcium may act through the A type of GABA receptors, which are mainly located on cholinergic neurons though cAMP pathway and partially on nonneuronal cells in the rat stomach. PMID:21294907

Role of taurine on acid secretion in the rat stomach

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Ho Jau-Der

2011-02-01

Full Text Available Abstract Background Taurine has chemical structure similar to an inhibitory neurotransmitter, γ-aminobutyric acid (GABA. Previous studies on GABA in the stomach suggest GABAergic neuron is involved in acid secretion, but the effects of taurine are poor understood. Methods The effects of taurine on acid secretion, signal transduction, and localization of taurinergic neurons were determined in the rat stomach using everted whole stomach, RIA kit and immunohistochemical methods. Results We used antibodies against taurine-synthesizing enzyme, cysteine sulfuric acid decarboxylase (CSAD, and taurine. CSAD- and taurine-positive cells were found in the muscle and mucosal layers. Distributions of CSAD- and taurine-positive cells in both mucosal and muscle layers were heterogeneous in the stomach. Taurine at 10-9~10-4 M induced acid secretion, and the maximum secretion was at 10-5 M, 1.6-fold higher than the spontaneous secretion. Taurine-induced acid secretion was completely inhibited by bicuculline and atropine but not by cimetidine, proglumide, or strychnine. Atropine and tetrodotoxin (TTX completely inhibited the acid secretion induced by low concentrations of taurine and partially inhibited induced by high concentrations. Verapamil, a calcium blocker agent, inhibited acid output elicited by taurine. We assumed all Ca2+ channels involved in the response to these secretagogues were equally affected by verapamil. Intracellular cAMP (adenosine 3', 5'-monophosphat in the stomach significantly increased with taurine treatment in a dose-dependent manner. High correlation (r=0.859, p Conclusions Our results demonstrated for the first time in taurine-induced acid secretion due to increase intracellular calcium may act through the A type of GABA receptors, which are mainly located on cholinergic neurons though cAMP pathway and partially on nonneuronal cells in the rat stomach.

Regulation of hormone release by cultured cells from a thyrotropin-growth hormone-secreting pituitary tumor. Direct inhibiting effects of 3,5,3'-triiodothyronine and dexamethasone on thyrotropin secretion.

Science.gov (United States)

Lamberts, S W; Oosterom, R; Verleun, T; Krenning, E P; Assies, H

1984-08-01

The regulation of TSH and GH secretion was investigated in cultured tumor cells prepared from a mixed TSH/GH secreting pituitary tumor. The tumor tissue had been removed transsphenoidally from a patient with hyperthyroidism and inappropriately high serum TSH levels and acromegaly. TSH and GH secretion by cultured cells were stimulated in a parallel way by TRH (300 nM) and LHRH (50 nM), but were unaffected by bromocriptine (10 nM). Exposure of the tumor cells to dexamethasone (0.1 microM) or T3 (50 nM) had differential effects on hormone secretion. GH secretion was greatly stimulated by dexamethasone, but unaffected by T3. TSH secretion was inhibited both by T3 and by dexamethasone. So, T3 and glucocorticoids inhibit TSH release by the human pituitary tumor cells studied at least partly by means of a direct effect.

40 CFR 370.64 - What information can I claim as trade secret or confidential?

Science.gov (United States)

2010-07-01

... secret or confidential? 370.64 Section 370.64 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... secret or confidential? (a) Trade secrets. You may be able to withhold the name of a specific chemical... trade secret. The requirements for withholding trade secret information are set forth in EPCRA section...

Longitudinal Associations between Keeping a Secret and Psychosocial Adjustment in Adolescence

Science.gov (United States)

Frijns, Tom; Finkenauer, Catrin

2009-01-01

Increasing bodies of evidence suggest that keeping secrets may be detrimental to well-being and adjustment, whereas confiding secrets may alleviate the detriments of secrecy and benefit well-being and adjustment. However, few studies have addressed the consequences of keeping and confiding secrets simultaneously, and even fewer have done so…

Induction of insulin secretion in engineered liver cells by nitric oxide

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Özcan Sabire

2007-10-01

Full Text Available Abstract Background Type 1 Diabetes Mellitus results from an autoimmune destruction of the pancreatic beta cells, which produce insulin. The lack of insulin leads to chronic hyperglycemia and secondary complications, such as cardiovascular disease. The currently approved clinical treatments for diabetes mellitus often fail to achieve sustained and optimal glycemic control. Therefore, there is a great interest in the development of surrogate beta cells as a treatment for type 1 diabetes. Normally, pancreatic beta cells produce and secrete insulin only in response to increased blood glucose levels. However in many cases, insulin secretion from non-beta cells engineered to produce insulin occurs in a glucose-independent manner. In the present study we engineered liver cells to produce and secrete insulin and insulin secretion can be stimulated via the nitric oxide pathway. Results Expression of either human insulin or the beta cell specific transcription factors PDX-1, NeuroD1 and MafA in the Hepa1-6 cell line or primary liver cells via adenoviral gene transfer, results in production and secretion of insulin. Although, the secretion of insulin is not significantly increased in response to high glucose, treatment of these engineered liver cells with L-arginine stimulates insulin secretion up to three-fold. This L-arginine-mediated insulin release is dependent on the production of nitric oxide. Conclusion Liver cells can be engineered to produce insulin and insulin secretion can be induced by treatment with L-arginine via the production of nitric oxide.

Secretion of pancreastatins from the porcine digestive tract

International Nuclear Information System (INIS)

Boerglum Jensen, T.D.; Holst, J.J.; Fahrenkrug, J.

1994-01-01

Pancreastatin, a 49-amino acid peptide with a COOH-terminal glycine amide, was originally isolated from porcine pancreas, but pancreastatin immunoreactivity has been found in several neuroendocrine tissues. There are strong indications that pancreastatin is derived from chromogranin A, since the amino acid sequence 240-288 in porcine chromogranin A corresponds to pancreastatin flanked by typical signals for proteolytic processing. The authors studied the effect of electric stimulation of the nervous supply to perfused porcine pancreas, antrum, nonantral stomach, and small intestine on the release of immunoreactive pancreastatin, and they have characterized the molecular nature of the secreted immunoreactivity by using a radioimmunoassay specific for the COOH-terminal glycine amide of porcine pancreastatin in combination with chromatography. In all tissues nerve stimulation significantly increased the release of immunoreactive pancreastatin. The secreted immunoreactive pancreastatin was heterogeneous, consisting of pancreastatin itself, a COOH-terminal pancreastatin fragment, and NH 2 -terminally extended pancreastatin forms. Pancreastatin predominated in the perfusate from pancreas and antrum, whereas mainly NH 2 -terminally extended molecular forms were secreted from the antrectomized stomach and small intestine. The different molecular forms of pancreastatin were secreted from the perfused organs in the same molar ratio as they occur in extracts of the corresponding tissues. Thus, pancreastatin and other chromogranin A-derived peptides in organ-specific proportions regularly accompany the secretion of the peptide hormones from the gastrointestinal tissues on appropriate stimulation. 40 refs., 5 figs

Pancreatic exocrine secretion in atomic bomb survivors

International Nuclear Information System (INIS)

Hiraoka, Masataka; Kawanishi, Masahiro; Ohtaki, Megu

1989-01-01

This study was designed to examine the effect of A-bombing on pancreatic exocrine secretion in 6 A-bomb survivors (an average age of 57 years) and the age- and sex-matched non-exposed 6 persons (an average age of 58 years). Six A-bomb survivors consisted of: three who had been directly exposed to A-bombing, one who had entered the city within 3 days after bombing, one who had worked in caring for A-bomb survivors, and one who had later entered the city. Caerulein-Secretin test revealed no significant difference in the total secretion of lipase, maximum bicarbonate, amylase output, or lipase output between the exposed and non-exposed groups. The concentration of lipase ten min after stimulation was significantly decreased in the exposed group than the control group. This suggests that radiation may be responsible for abnormality in the ability of pancreatic exocrine secretion. (N.K.)

Floral Longevity and Nectar Secretion of Platanthera chlorantha (Custer) Rchb. (Orchidaceae)

OpenAIRE

STPICZYŃSKA, MAŁGORZATA

2003-01-01

Flowering and nectar secretion were studied in Platanthera chlorantha in two years. Nectar was secreted and accumulated in this orchid’s spur, originating from part of the labellum. The nectary spur was, on average, 32 mm long. It produced 6·86 µl nectar in 1999 and 7·84 µl in 2000. The number of flowers per inflorescence and the volume of nectar secreted per flower were not correlated. Nectar secretion and flower longevity differed depending on pollination and flower position in the inflores...

Pituitary tumour causing gigantism. Morphology and in vitro hormone secretion.

Science.gov (United States)

Anniko, M; Ritzén, E M

1986-01-01

True gigantism with overproduction of growth hormone (GH) and prolactin (PRL) was diagnosed in a 13-year-old boy. The clinical history indicated that the tumour had caused an oversecretion of GH since the age of 4-5 years. At diagnosis, the sella turcica was markedly enlarged. No infiltrative growth was noted at surgery. Endocrine investigations showed elevated GH and PRL secretion. Light and electron microscopy of tumour tissue revealed densely packed pleomorphic cells of both GH and PRL type. In addition, oncocyte-like cells were observed. Organ culture of pieces of tumour tissue demonstrated continued secretion of GH and PRL into the medium for more than 5 days in vitro. Addition of bromocriptine to the medium caused a rapid decline in PRL secretion while GH secretion remained the same. X-ray irradiation in vitro also caused a decrease in PRL secretion. These effects of bromocriptine and X-ray on hormone secretion in vitro mirrored the corresponding effect of treatment, when the patient showed signs of tumour recurrence after pituitary surgery. It is concluded that also in childhood, the in vitro response of tumour tissue to various treatments may be explored as a possible way to predict the efficacy of pharmacological or irradiation treatment of pituitary tumours.

Social and cognitive factors associated with children's secret-keeping for a parent.

Science.gov (United States)

Gordon, Heidi M; Lyon, Thomas D; Lee, Kang

2014-01-01

This study examined children's secret-keeping for a parent and its relation to trust, theory of mind, secrecy endorsement, and executive functioning (EF). Children (N = 107) between 4 and 12 years of age participated in a procedure wherein parents broke a toy and asked children to promise secrecy. Responses to open-ended and direct questions were examined. Overall, secret-keeping increased with age and promising to keep the secret was related to fewer disclosures in open-ended questioning. Children who kept the secret in direct questioning exhibited greater trust and better parental ratings of EF than children who disclosed the secret. Findings highlight the importance of both social and cognitive factors in secret-keeping development. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

Science.gov (United States)

Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

2014-01-01

The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

Renal renin secretion as regulator of body fluid homeostasis

DEFF Research Database (Denmark)

Damkjær, Mads; Isaksson, Gustaf L; Stubbe, Jane

2013-01-01

The renin-angiotensin system is essential for body fluid homeostasis and blood pressure regulation. This review focuses on the homeostatic regulation of the secretion of active renin in the kidney, primarily in humans. Under physiological conditions, renin secretion is determined mainly by sodium...

Bidirectional regulation of bakuchiol, an estrogenic-like compound, on catecholamine secretion

Energy Technology Data Exchange (ETDEWEB)

Mao, Haoping; Wang, Hong; Ma, Shangwei; Xu, Yantong; Zhang, Han; Wang, Yuefei [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China); Niu, Zichang [First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin (China); Fan, Guanwei; Zhu, Yan [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China); Gao, Xiu Mei, E-mail: gaoxiumei@tjutcm.edu.cn [Tianjin State Key Laboratory of Modern Chinese Medicine, Key Laboratory of Pharmacology of Traditional Chinese Medicine Formulae (China); Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin (China)

2014-01-01

Excess or deficiency of catecholamine (CA) secretion was related with several diseases. Recently, estrogen and phytoestrogens were reported to regulate the activity of CA system. Bakuchiol is a phytoestrogen isolated from the seeds of Psoralea corylifolia L. (Leguminosae) which has been used in Traditional Chinese medicine as a tonic or aphrodisiac. In the present study, bovine adrenal medullary cells were employed to investigate the effects and mechanisms of bakuchiol on the regulation of CA secretion. Further, its anti-depressant like and anti-stress effects were evaluated by using behavioral despair and chronic immobilization stress models. Our results indicated that bakuchiol showed bidirectional regulation on CA secretion. It stimulated basal CA secretion in a concentration dependent manner (p < 0.01), while it reduced 300 μM acetylcholine (ACh) (p < 0.01), 100 μM veratridine (Ver) (p < 0.01) and 56 mM K{sup +} (p < 0.05) induced CA secretion, respectively. We also found that the stimulation of basal CA secretion by bakuchiol may act through estrogen-like effect and the JNK pathway in an extra-cellular calcium independent manner. Further, bakuchiol elevated tyrosine hydroxylase Ser40 and Ser31 phosphorylation (p < 0.01) through the PKA and ERK1/2 pathways, respectively. Bakuchiol inhibited ACh, Ver and 56 mM K{sup +} induced CA secretion was related with reduction of intracellular calcium rise. In vivo experiments, we found that bakuchiol significantly reduced immobilization time in behavioral despair mouse (p < 0.05 or 0.01), and plasma epinephrine (E) and norepinephrine (NE) levels in chronic immobilization stress (p < 0.05). Overall, these results present a bidirectional regulation of bakuchiol on CA secretion which indicated that bakuchiol may exert anti-stress and the potential anti-depressant-like effects. - Highlights: • Bakuchiol stimulated basal catecholamine secretion. • Bakuchiol inhibited various secretagogues induced catecholamine secretion

Secure direct communication based on secret transmitting order of particles

International Nuclear Information System (INIS)

Zhu Aidong; Zhang Shou; Xia Yan; Fan Qiubo

2006-01-01

We propose the schemes of quantum secure direct communication based on a secret transmitting order of particles. In these protocols, the secret transmitting order of particles ensures the security of communication, and no secret messages are leaked even if the communication is interrupted for security. This strategy of security for communication is also generalized to a quantum dialogue. It not only ensures the unconditional security but also improves the efficiency of communication

Family secrets: Law and understandings of openness in everyday relationships

OpenAIRE

Smart, Carol

2009-01-01

Uncovering old or historical family secrets has become an enjoyable pastime yet in contemporary families the keeping of secrets, especially those relating to reproduction and paternity, is seen increasingly as undesirable. This article explores these issues and the growing tendency for family law and policy to favour exposing genetic truths seeing this form of scientific veracity as crucial to child welfare and equality. The article explores the changing contexts of family secrets (using data...

Proprotein Convertases Process Pmel17 during Secretion*

Science.gov (United States)

Leonhardt, Ralf M.; Vigneron, Nathalie; Rahner, Christoph; Cresswell, Peter

2011-01-01

Pmel17 is a melanocyte/melanoma-specific protein that traffics to melanosomes where it forms a fibrillar matrix on which melanin gets deposited. Before being cleaved into smaller fibrillogenic fragments the protein undergoes processing by proprotein convertases, a class of serine proteases that typically recognize the canonical motif RX(R/K)R↓. The current model of Pmel17 maturation states that this processing step occurs in melanosomes, but in light of recent reports this issue has become controversial. We therefore addressed this question by thoroughly assessing the processing kinetics of either wild-type Pmel17 or a secreted soluble Pmel17 derivative. Our results demonstrate clearly that processing of Pmel17 occurs during secretion and that it does not require entry of the protein into the endocytic system. Strikingly, processing proceeds even in the presence of the secretion inhibitor monensin, suggesting that Pmel17 is an exceptionally good substrate. In line with this, we find that newly synthesized surface Pmel17 is already quantitatively cleaved. Moreover, we demonstrate that Pmel17 function is independent of the sequence identity of its unconventional proprotein convertase-cleavage motif that lacks arginine in P4 position. The data alter the current view of Pmel17 maturation and suggest that the multistep processing of Pmel17 begins with an early cleavage during secretion that primes the protein for later functional processing. PMID:21247888

Developmental co-expression of small molecular weight apolipoprotein B synthesis and triacylglycerol secretion

International Nuclear Information System (INIS)

Coleman, R.A.; Haynes, E.B.; Sand, T.M.; Davis, R.A.

1987-01-01

The development of the liver's ability to coordinately express the synthesis and secretion of the two major components of very low density lipoproteins (VLDL): triacylglycerol (TG) and apolipoprotein B (apo B) was examined in cultured hepatocytes obtained from fetal, suckling and adult rats. Hepatocytes from fetal and suckling rats synthesized and secreted TG at rates lower than that displayed by adult cells. When TG synthesis was equalized by adding oleic acid to the culture medium, fetal cells still secreted only 39% as much TG as did adult cells. To determine the basis for the apparent defect in VLDL assembly/secretion displayed by fetal cells, the synthesis and secretion of [ 35 S]methionine-labeled apo B was quantified by immunoprecipitation. Although adult and fetal cells synthesized and secreted large molecular weight apo B at similar rates, the synthesis and secretion of small molecular weight apo B was 2-fold greater in adult cells. These data suggest that the ability to assemble/secrete VLDL triacylglycerol varies in parallel with the developmental expression of small molecular weight apo B. Furthermore, these studies show the usefulness of the cultured rat hepatocyte model for examining the ontogeny and regulation of VLDL assembly/secretion

Thyrotropin Secretion in Mild and Severe Primary Hypothyroidism Is Distinguished by Amplified Burst Mass and Basal Secretion with Increased Spikiness and Approximate Entropy

NARCIS (Netherlands)

Roelfsema, Ferdinand; Pereira, Alberto M.; Adriaanse, Ria; Endert, Erik; Fliers, Eric; Romijn, Johannes A.; Veldhuis, Johannes D.

2010-01-01

Context: Twenty-four-hour TSH secretion profiles in primary hypothyroidism have been analyzed with methods no longer in use. The insights afforded by earlier methods are limited. Objective: We studied TSH secretion in patients with primary hypothyroidism (eight patients with severe and eight

Radioimmunologic study of insulin secretion during acute radiation sickness

International Nuclear Information System (INIS)

Barkalaya, A.I.

1977-01-01

Insulin secretion in irradiated (750 R) albino rats has been studied radioimmunologically. The data obtained were correlated with the corticosterone and glucose contents of blood. It has been shown that there is a risk of relative incompetence of insulin secretion during the hypercorticoidism and hyperglycemia

Radioimmunologic study of insulin secretion during acute radiation sickness

Energy Technology Data Exchange (ETDEWEB)

Barkalaya, A I

1977-01-01

Insulin secretion in irradiated (750 R) albino rats has been studied radioimmunologically. The data obtained were correlated with the corticosterone and glucose contents of blood. It has been shown that there is a risk of relative incompetence of insulin secretion during the hypercorticoidism and hyperglycemia.

Climate change reduces nectar secretion in two common Mediterranean plants.

Science.gov (United States)

Takkis, Krista; Tscheulin, Thomas; Tsalkatis, Panagiotis; Petanidou, Theodora

2015-09-15

Global warming can lead to considerable impacts on natural plant communities, potentially inducing changes in plant physiology and the quantity and quality of floral rewards, especially nectar. Changes in nectar production can in turn strongly affect plant-pollinator interaction networks-pollinators may potentially benefit under moderate warming conditions, but suffer as resources reduce in availability as elevated temperatures become more extreme. Here, we studied the effect of elevated temperatures on nectar secretion of two Mediterranean Lamiaceae species-Ballota acetabulosa and Teucrium divaricatum. We measured nectar production (viz. volume per flower, sugar concentration per flower and sugar content per flower and per plant), number of open and empty flowers per plant, as well as biomass per flower under a range of temperatures selected ad hoc in a fully controlled climate chamber and under natural conditions outdoors. The average temperature in the climate chamber was increased every 3 days in 3 °C increments from 17.5 to 38.5 °C. Both study species showed a unimodal response of nectar production (volume per flower, sugar content per flower and per plant) to temperature. Optimal temperature for sugar content per flower was 25-26 °C for B. acetabulosa and 29-33 °C for T. divaricatum. According to our results, moderate climate warming predicted for the next few decades could benefit nectar secretion in T. divaricatum as long as the plants are not water stressed, but have a moderate negative effect on B. acetabulosa. Nevertheless, strong warming as predicted by climate change models for the end of the 21st century is expected to reduce nectar secretion in both species and can thus significantly reduce available resources for both wild bees and honeybees in Mediterranean systems. Published by Oxford University Press on behalf of the Annals of Botany Company.

Cryptanalysis of quantum secret sharing based on GHZ states

Energy Technology Data Exchange (ETDEWEB)

Liu Xiaofen; Pan Rijing, E-mail: liuxiaofen23@fjnu.edu.cn [School of Mathematics and Computer Science, Fujian Normal University, Fuzhou 350007 (China); Key Laboratory of Network Security and Cryptography, Fujian Normal University, Fuzhou 350007 (China)

2011-10-15

In a recent paper (Hwang et al 2011 Phys. Scr. 83 045004), a subtle quantum secret sharing (QSS) protocol was proposed. One major advantage of this protocol is its high efficiency; that is, it is more efficient than other QSS protocols using the Greenberger-Horne-Zeilinger states. However, we analyzed the security of this protocol and found that it is insecure for one agent who may deduce half of the information about the deal's secret directly just by his/her piece of secret. Finally, a feasible improvement of this QSS protocol is put forward.

Matryoshka: Hiding Secret Communication in Plain Sight

OpenAIRE

Safaka, Iris; Fragouli, Christina; Argyraki, Katerina

2016-01-01

We want to enable a pair of communicating users to exchange secret messages while hiding the fact that secret communication is taking place. We propose a linguistic steganography approach, where each human message is hidden in another human-like message. A hard open question is how to keep the steganographic message small -- existing related tools tend to blow up its size, thereby revealing the use of steganography. We encrypt by compressing each message, mapping it to a plausible sequence of...

Percolation of secret correlations in a network

OpenAIRE

Leverrier, Anthony; García-Patrón, Raúl

2011-01-01

In this work, we explore the analogy between entanglement and secret classical correlations in the context of large networks, more precisely the question of percolation of secret correlations in a network. It is known that entanglement percolation in quantum networks can display a highly nontrivial behavior depending on the topology of the network and on the presence of entanglement between the nodes. Here we show that this behavior, thought to be of a genuine quantum nature, also occurs in a...

Percolation of secret correlations in a network

Energy Technology Data Exchange (ETDEWEB)

Leverrier, Anthony; Garcia-Patron, Raul [ICFO-Institut de Ciencies Fotoniques, 08860 Castelldefels (Barcelona) (Spain); Research Laboratory of Electronics, MIT, Cambridge, MA 02139 (United States) and Max-Planck Institut fur Quantenoptik, Hans-Kopfermann Str. 1, D-85748 Garching (Germany)

2011-09-15

In this work, we explore the analogy between entanglement and secret classical correlations in the context of large networks--more precisely, the question of percolation of secret correlations in a network. It is known that entanglement percolation in quantum networks can display a highly nontrivial behavior depending on the topology of the network and on the presence of entanglement between the nodes. Here we show that this behavior, thought to be of a genuine quantum nature, also occurs in a classical context.

Percolation of secret correlations in a network

International Nuclear Information System (INIS)

Leverrier, Anthony; Garcia-Patron, Raul

2011-01-01

In this work, we explore the analogy between entanglement and secret classical correlations in the context of large networks--more precisely, the question of percolation of secret correlations in a network. It is known that entanglement percolation in quantum networks can display a highly nontrivial behavior depending on the topology of the network and on the presence of entanglement between the nodes. Here we show that this behavior, thought to be of a genuine quantum nature, also occurs in a classical context.

'Secret' Shuttle payloads revealed

Science.gov (United States)

Powell, Joel W.

1993-05-01

A secret military payload carried by the orbiter Discovery launched on January 24 1985 is discussed. Secondary payloads on the military Shuttle flights are briefly reviewed. Most of the military middeck experiments were sponsored by the Space Test Program established at the Pentagon to oversee all Defense Department space research projects.

Pharmacokinetics of natural and engineered secreted factors delivered by mesenchymal stromal cells.

Directory of Open Access Journals (Sweden)

Jessica S Elman

Full Text Available Transient cell therapy is an emerging drug class that requires new approaches for pharmacological monitoring during use. Human mesenchymal stem cells (MSCs are a clinically-tested transient cell therapeutic that naturally secrete anti-inflammatory factors to attenuate immune-mediated diseases. MSCs were used as a proof-of-concept with the hypothesis that measuring the release of secreted factors after cell transplantation, rather than the biodistribution of the cells alone, would be an alternative monitoring tool to understand the exposure of a subject to MSCs. By comparing cellular engraftment and the associated serum concentration of secreted factors released from the graft, we observed clear differences between the pharmacokinetics of MSCs and their secreted factors. Exploration of the effects of natural or engineered secreted proteins, active cellular secretion pathways, and clearance mechanisms revealed novel aspects that affect the systemic exposure of the host to secreted factors from a cellular therapeutic. We assert that a combined consideration of cell delivery strategies and molecular pharmacokinetics can provide a more predictive model for outcomes of MSC transplantation and potentially other transient cell therapeutics.

Epidermal growth factor (EGF) inhibits stimulated thyroid hormone secretion in the mouse

International Nuclear Information System (INIS)

Ahren, B.

1987-01-01

It is known that epidermal growth factor (EGF) inhibits iodide uptake in the thyroid follicular cells and lowers plasma levels of thyroid hormones upon infusion into sheep and ewes. In this study, the effects of EGF on basal and stimulated thyroid hormone secretion were investigated in the mouse. Mice were pretreated with 125 I and thyroxine; the subsequent release of 125 I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was not altered by intravenous injection of EGF (5 micrograms/animal). However, the radioiodine secretion stimulated by both TSH (120 microU/animal) and vasoactive intestinal peptide (VIP; 5 micrograms/animal) were inhibited by EGF (5 micrograms/animal). At a lower dose level (0.5 microgram/animal), EGF had no influence on stimulated radioiodine secretion. In conclusion, EGF inhibits stimulated thyroid hormone secretion in the mouse

Influence of Flavonoids on Mechanism of Modulation of Insulin Secretion.

Science.gov (United States)

Soares, Juliana Mikaelly Dias; Pereira Leal, Ana Ediléia Barbosa; Silva, Juliane Cabral; Almeida, Jackson R G S; de Oliveira, Helinando Pequeno

2017-01-01

The development of alternatives for insulin secretion control in vivo or in vitro represents an important aspect to be investigated. In this direction, natural products have been progressively explored with this aim. In particular, flavonoids are potential candidates to act as insulin secretagogue. To study the influence of flavonoid on overall modulation mechanisms of insulin secretion. The research was conducted in the following databases and platforms: PubMed, Scopus, ISI Web of Knowledge, SciELO, LILACS, and ScienceDirect, and the MeSH terms used for the search were flavonoids, flavones, islets of Langerhans, and insulin-secreting cells. Twelve articles were included and represent the basis of discussion on mechanisms of insulin secretion of flavonoids. Papers in ISI Web of Knowledge were in number of 1, Scopus 44, PubMed 264, ScienceDirect 511, and no papers from LILACS and SciELO databases. According to the literature, the majority of flavonoid subclasses can modulate insulin secretion through several pathways, in an indication that corresponding molecule is a potential candidate for active materials to be applied in the treatment of diabetes. The action of natural products on insulin secretion represents an important investigation topic due to their importance in the diabetes controlIn addition to their typical antioxidant properties, flavonoids contribute to the insulin secretionThe modulation of insulin secretion is induced by flavonoids according to different mechanisms. Abbreviations used: K ATP channels: ATP-sensitive K + channels, GLUT4: Glucose transporter 4, ERK1/2: Extracellular signal-regulated protein kinases 1 and 2, L-VDCCs: L-type voltage-dependent Ca +2 channels, GLUT1: Glucose transporter 1, AMPK: Adenosine monophosphate-activated protein kinase, PTP1B: Protein tyrosine phosphatase 1B, GLUT2: Glucose transporter 2, cAMP: Cyclic adenosine monophosphate, PKA: Protein kinase A, PTK: Protein tyrosine kinase, CaMK II: Ca 2+ /calmodulin

Increased VLDL-triglyceride secretion precedes impaired control of endogenous glucose production in obese, normoglycemic men.

Science.gov (United States)

Sørensen, Lars P; Søndergaard, Esben; Nellemann, Birgitte; Christiansen, Jens S; Gormsen, Lars C; Nielsen, Søren

2011-09-01

To assess basal and insulin-mediated VLDL-triglyceride (TG) kinetics and the relationship between VLDL-TG secretion and hepatic insulin resistance assessed by endogenous glucose production (EGP) in obese and lean men. A total of 12 normoglycemic, obese (waist-to-hip ratio >0.9, BMI >30 kg/m(2)) and 12 lean (BMI 20-25 kg/m(2)) age-matched men were included. Ex vivo-labeled [1-(14)C]VLDL-TGs and [3-(3)H]glucose were infused postabsorptively and during a hyperinsulinemic-euglycemic clamp to determine VLDL-TG kinetics and EGP. Body composition was determined by dual X-ray absorptiometry and computed tomography scanning. Energy expenditure and substrate oxidation rates were measured by indirect calorimetry. Basal VLDL-TG secretion rates were increased in obese compared with lean men (1.25 ± 0.34 vs. 0.86 ± 0.34 μmol/kg fat-free mass [FFM]/min; P = 0.011), whereas there was no difference in clearance rates (150 ± 56 vs. 162 ± 77 mL/min; P = NS), resulting in greater VLDL-TG concentrations (0.74 ± 0.40 vs. 0.38 ± 0.20 mmol/L; P = 0.011). The absolute insulin-mediated suppression of VLDL-TG secretion was similar in the groups. However, the percentage reduction (-36 ± 18 vs. -54 ± 10%; P = 0.008) and achieved VLDL-TG secretion rates (0.76 ± 0.20 vs. 0.41 ± 0.19 μmol/kg FFM/min; P lean men (-17 ± 18 vs. 7 ± 20%; P = 0.007), resulting in less percentage reduction of VLDL-TG concentrations in obese men (-22 ± 20 vs. -56 ± 11%; P < 0.001). Insulin-suppressed EGP was similar (0.4 [0.0-0.8] vs. 0.1 [0.0-1.2] mg/kg FFM/min (median [range]); P = NS), and the percentage reduction was equivalent (-80% [57-98] vs. -98% [49-100], P = NS). Insulin-mediated glucose disposal was significantly reduced in obese men. Basal VLDL-TG secretion rates are increased in normoglycemic but insulin-resistant, obese men, resulting in hypertriglyceridemia. Insulin-mediated suppression of EGP is preserved in obese men, whereas suppression of VLDL-TG secretion is less pronounced in obese

Nitrogen: Unraveling the Secret to Stable Carbon-Supported Pt-Alloy Electrocatalysts

Science.gov (United States)

2013-10-01

release; distribution is unlimited. Nitrogen: unraveling the secret to stable carbon-supported Pt- alloy electrocatalysts The views, opinions and/or...Nitrogen: unraveling the secret to stable carbon-supported Pt-alloy electrocatalysts Report Title Nitrogen functionalities significantly improve...design and optimization of next generation high performance catalyst materials. Nitrogen: unraveling the secret to stable carbon-supported Pt-alloy

Extracellular vesicles secreted from cancer cell lines stimulate secretion of MMP-9, IL-6, TGF-β1 and EMMPRIN.

Directory of Open Access Journals (Sweden)

Jasmina S Redzic

Full Text Available Extracellular vesicles (EVs are key contributors to cancer where they play an integral role in cell-cell communication and transfer pro-oncogenic molecules to recipient cells thereby conferring a cancerous phenotype. Here, we purified EVs using straightforward biochemical approaches from multiple cancer cell lines and subsequently characterized these EVs via multiple biochemical and biophysical methods. In addition, we used fluorescence microscopy to directly show internalization of EVs into the recipient cells within a few minutes upon addition of EVs to recipient cells. We confirmed that the transmembrane protein EMMPRIN, postulated to be a marker of EVs, was indeed secreted from all cell lines studied here. We evaluated the response to EV stimulation in several different types of recipient cells lines and measured the ability of these purified EVs to induce secretion of several factors highly upregulated in human cancers. Our data indicate that purified EVs preferentially stimulate secretion of several proteins implicated in driving cancer in monocytic cells but only harbor limited activity in epithelial cells. Specifically, we show that EVs are potent stimulators of MMP-9, IL-6, TGF-β1 and induce the secretion of extracellular EMMPRIN, which all play a role in driving immune evasion, invasion and inflammation in the tumor microenvironment. Thus, by using a comprehensive approach that includes biochemical, biological, and spectroscopic methods, we have begun to elucidate the stimulatory roles.

The Secret Driving Force Behind Mongolia’s Successful Democracy

Science.gov (United States)

2016-03-01

the nation’s democracy movement its earliest stages. Courtesy of the Democratic Union of Mongolia PRISM 6, no. 1 FROM THE FIELD | 141 The Secret Driving...assistance and trade. Our state budget PRISM 6, no. 1 FROM THE FIELD | 143 THE SECRET DRIVING FORCE BEHIND MONGOLIA’S SUCCESSFUL DEMOCRACY collapsed; we...O yungerel Tsedevdam ba (2006) PRISM 6, no. 1 FROM THE FIELD | 145 THE SECRET DRIVING FORCE BEHIND MONGOLIA’S SUCCESSFUL DEMOCRACY significantly as

Hiding secret data into a carrier image

Directory of Open Access Journals (Sweden)

Ovidiu COSMA

2012-06-01

Full Text Available The object of steganography is embedding hidden information in an appropriate multimedia carrier, e.g., image, audio, or video. There are several known methods of solving this problem, which operate either in the space domain or in the frequency domain, and are distinguished by the following characteristics: payload, robustness and strength. The payload is the amount of secret data that can be embedded in the carrier without inducing suspicious artefacts, robustness indicates the degree in which the secret data is affected by the normal processing of the carrier e.g., compression, and the strength indicate how easy the presence of hidden data can be detected by steganalysis techniques. This paper presents a new method of hiding secret data into a digital image compressed by a technique based on the Discrete Wavelet Transform (DWT [2] and the Set Partitioning In Hierarchical Trees (SPIHT subband coding algorithm [6]. The proposed method admits huge payloads and has considerable strength.

Antifungal activity of epithelial secretions from selected frog species ...

African Journals Online (AJOL)

This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions ...

The mechanism of biliary lipid secretion and its defects

NARCIS (Netherlands)

Elferink, R. P.; Groen, A. K.

1999-01-01

Biliary lipid secretion is an important physiological event; not only for the disposal of cholesterol from the body, but also for the protection of cells lining the biliary tree against bile salts. Insight into the (patho)physiological role of biliary lipid secretion has been recently expanded

Characterization of Pseudomonas aeruginosa Chitinase, a Gradually Secreted Protein

NARCIS (Netherlands)

Folders, J. (Jindra); Algra, J. (Jon); Roelofs, M.S. (Marc); Loon, L.C. van; Tommassen, J.P.M.; Bitter, Wilbert

2001-01-01

The gram-negative bacterium Pseudomonas aeruginosa secretes many proteins into its extracellular environment via the type I, II, and III secretion systems. In this study, a gene, chiC, coding for an extracellular chitinolytic enzyme, was identified. The chiC gene encodes a polypeptide of 483 amino

DNA Delivery and Genomic Integration into Mammalian Target Cells through Type IV A and B Secretion Systems of Human Pathogens

Directory of Open Access Journals (Sweden)

Dolores L. Guzmán-Herrador

2017-08-01

Full Text Available We explore the potential of bacterial secretion systems as tools for genomic modification of human cells. We previously showed that foreign DNA can be introduced into human cells through the Type IV A secretion system of the human pathogen Bartonella henselae. Moreover, the DNA is delivered covalently attached to the conjugative relaxase TrwC, which promotes its integration into the recipient genome. In this work, we report that this tool can be adapted to other target cells by using different relaxases and secretion systems. The promiscuous relaxase MobA from plasmid RSF1010 can be used to deliver DNA into human cells with higher efficiency than TrwC. MobA also promotes DNA integration, albeit at lower rates than TrwC. Notably, we report that DNA transfer to human cells can also take place through the Type IV secretion system of two intracellular human pathogens, Legionella pneumophila and Coxiella burnetii, which code for a distantly related Dot/Icm Type IV B secretion system. This suggests that DNA transfer could be an intrinsic ability of this family of secretion systems, expanding the range of target human cells. Further analysis of the DNA transfer process showed that recruitment of MobA by Dot/Icm was dependent on the IcmSW chaperone, which may explain the higher DNA transfer rates obtained. Finally, we observed that the presence of MobA negatively affected the intracellular replication of C. burnetii, suggesting an interference with Dot/Icm translocation of virulence factors.

Secret-Key Agreement with Public Discussion subject to an Amplitude Constraint

KAUST Repository

Zorgui, Marwen

2016-04-06

This paper considers the problem of secret-key agreement with public discussion subject to a peak power constraint A on the channel input. The optimal input distribution is proved to be discrete with finite support. To overcome the computationally heavy search for the optimal discrete distribution, several suboptimal schemes are proposed and shown numerically to perform close to the capacity. Moreover, lower and upper bounds for the secret-key capacity are provided and used to prove that the secret-key capacity converges for asymptotic high values of A, to the secret-key capacity with an average power constraint A2. Finally, when the amplitude constraint A is small (A ! 0), the secret-key capacity is proved to be asymptotically equal to the capacity of the legitimate user with an amplitude constraint A and no secrecy constraint.

Secret-Key Agreement with Public Discussion subject to an Amplitude Constraint

KAUST Repository

Zorgui, Marwen; Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

2016-01-01

This paper considers the problem of secret-key agreement with public discussion subject to a peak power constraint A on the channel input. The optimal input distribution is proved to be discrete with finite support. To overcome the computationally heavy search for the optimal discrete distribution, several suboptimal schemes are proposed and shown numerically to perform close to the capacity. Moreover, lower and upper bounds for the secret-key capacity are provided and used to prove that the secret-key capacity converges for asymptotic high values of A, to the secret-key capacity with an average power constraint A2. Finally, when the amplitude constraint A is small (A ! 0), the secret-key capacity is proved to be asymptotically equal to the capacity of the legitimate user with an amplitude constraint A and no secrecy constraint.

Diversity and subcellular distribution of archaeal secreted proteins

Directory of Open Access Journals (Sweden)

Mechthild ePohlschroder

2012-07-01

Full Text Available Secreted proteins make up a significant percentage of a prokaryotic proteome and play critical roles in important cellular processes such as polymer degradation, nutrient uptake, signal transduction, cell wall biosynthesis and motility. The majority of archaeal proteins are believed to be secreted either in an unfolded conformation via the universally conserved Sec pathway or in a folded conformation via the Twin arginine transport (Tat pathway. Extensive in vivo and in silico analyses of N-terminal signal peptides that target proteins to these pathways have led to the development of computational tools that not only predict Sec and Tat substrates with high accuracy but also provide information about signal peptide processing and targeting. Predictions therefore include indications as to whether a substrate is a soluble secreted protein, a membrane or cell-wall anchored protein, or a surface structure subunit, and whether it is targeted for post-translational modification such as glycosylation or the addition of a lipid. The use of these in silico tools, in combination with biochemical and genetic analyses of transport pathways and their substrates, has resulted in improved predictions of the subcellular localization of archaeal secreted proteins, allowing for a more accurate annotation of archaeal proteomes, and has led to the identification of potential adaptations to extreme environments, as well as archaeal kingdom-specific pathways. A more comprehensive understanding of the transport pathways and post-translational modifications of secreted archaeal proteins will also generate invaluable insights that will facilitate the identification of commercially valuable archaeal enzymes and the development of heterologous systems in which to efficiently express them.

Diversity and subcellular distribution of archaeal secreted proteins.

Science.gov (United States)

Szabo, Zalan; Pohlschroder, Mechthild

2012-01-01

Secreted proteins make up a significant percentage of a prokaryotic proteome and play critical roles in important cellular processes such as polymer degradation, nutrient uptake, signal transduction, cell wall biosynthesis, and motility. The majority of archaeal proteins are believed to be secreted either in an unfolded conformation via the universally conserved Sec pathway or in a folded conformation via the Twin arginine transport (Tat) pathway. Extensive in vivo and in silico analyses of N-terminal signal peptides that target proteins to these pathways have led to the development of computational tools that not only predict Sec and Tat substrates with high accuracy but also provide information about signal peptide processing and targeting. Predictions therefore include indications as to whether a substrate is a soluble secreted protein, a membrane or cell wall anchored protein, or a surface structure subunit, and whether it is targeted for post-translational modification such as glycosylation or the addition of a lipid. The use of these in silico tools, in combination with biochemical and genetic analyses of transport pathways and their substrates, has resulted in improved predictions of the subcellular localization of archaeal secreted proteins, allowing for a more accurate annotation of archaeal proteomes, and has led to the identification of potential adaptations to extreme environments, as well as phyla-specific pathways among the archaea. A more comprehensive understanding of the transport pathways used and post-translational modifications of secreted archaeal proteins will also facilitate the identification and heterologous expression of commercially valuable archaeal enzymes.

Secretion clearance strategies in Australian and New Zealand Intensive Care Units.

Science.gov (United States)

Ntoumenopoulos, George; Hammond, Naomi; Watts, Nicola R; Thompson, Kelly; Hanlon, Gabrielle; Paratz, Jennifer D; Thomas, Peter

2017-06-26

To describe the processes of care for secretion clearance in adult, intubated and mechanically ventilated patients in Australian and New Zealand Intensive Care Units (ICUs). A prospective, cross-sectional study was conducted through the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS CTG) Point Prevalence Program. Forty-seven ICUs collected data from 230 patients intubated and ventilated on the study day. Secretion clearance techniques beyond standard suctioning were used in 84/230 (37%) of patients during the study period. Chest wall vibration 34/84 (40%), manual lung hyperinflation 24/84 (29%), chest wall percussion 20/84 (24%), postural drainage/patient positioning 17/84 (20%) and other techniques including mobilisation 15/84 (18%), were the most common secretion clearance techniques employed. On average (SD), patients received airway suctioning 8.8 (5.0) times during the 24-h study period. Mucus plugging events were infrequent (2.7%). The additional secretion clearance techniques were provided by physiotherapy staff in 24/47 (51%) ICUs and by both nursing and physiotherapy staff in the remaining 23/47 (49%) ICUs. One-third of intubated and ventilated patients received additional secretion clearance techniques. Mucus plugging events were infrequent with these additional secretion clearance approaches. Prospective studies must examine additional secretion clearance practices, prevalence of mucus plugging episodes and impact on patient outcomes. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Secret Sharing and Secure Computing from Monotone Formulae

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre; Kölker, Jonas; Miltersen, Peter Bro

2012-01-01

We present a construction of log-depth formulae for various threshold functions based on atomic threshold gates of constant size. From this, we build a new family of linear secret sharing schemes that are multiplicative, scale well as the number of players increases and allows to raise a shared...... of our scheme for pseudorandom secret sharing as defined by Cramer, Damgård and Ishai...

Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

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Reid, Ian A.

1994-01-01

Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric

Social and cognitive factors associated with children’s secret-keeping for a parent

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Gordon, Heidi M.; Lyon, Thomas D.; Lee, Kang

2014-01-01

This study examined children’s secret-keeping for a parent and its relationship to trust, theory of mind, secrecy endorsement, and executive functioning (EF). Children (N = 107) between 4 and 12 years of age participated in a procedure wherein parents broke a toy and asked children to promise secrecy. Responses to open-ended and direct questions were examined. Overall, secret-keeping increased with age and promising to keep the secret was related to fewer disclosures in open-ended questioning. Children who kept the secret in direct questioning exhibited greater trust and better parental ratings of EF than children who disclosed the secret. Findings highlight the importance of both social and cognitive factors in secret-keeping development. PMID:25291258

[Abnormal vaginal secretion: sensitivity, specificity and concordance between clinical and cytological diagnosis].

Science.gov (United States)

de Camargo, Kélvia Cristina; Alves, Rosane Ribeiro Figueiredo; Baylão, Luciano Augusto; Ribeiro, Andrea Alves; Araujo, Nadja Lindany Alves de Souza; Tavares, Suelene Brito do Nascimento; dos Santos, Sílvia Helena Rabelo

2015-05-01

To estimate the prevalence of bacterial vaginosis (BV), candidiasis and trichomoniasis and compare the findings of physical examination of the vaginal secretion with the microbiological diagnosis obtained by cytology study of a vaginal smear using the Papanicolaou method. A cross-sectional study of 302 women aged 20 to 87 years, interviewed and submitted to a gynecology test for the evaluation of vaginal secretion and collection of a cytology smear, from June 2012 to May 2013. Sensitivity analyses were carried out and specificity, positive predictive value (PPV) and negative predictive value (NPV) with their respective 95%CI were determined to assess the accuracy of the characteristics of vaginal secretion in relation to the microbiological diagnosis of the cytology smear . The kappa index (k) was used to assess the degree of agreement between the clinical features of vaginal secretion and the microbiological findings obtained by cytology. RESULTS The prevalence of BV, candidiasis and trichomoniasis was 25.5, 9.3 and 2.0%, respectively. The sensitivity, specificity, PPV and NPV of the clinical characteristics of vaginal secretion for the cytological diagnosis of BV were 74, 78.6, 54.3 and 89.9%, respectively. The sensitivity, specificity, PPV and the NPV of the clinical characteristics of vaginal secretion for the cytological diagnosis of candidiasis were 46.4, 86.2, 25.5 and 94%, respectively. The correlation between the clinical evaluation of vaginal secretion and the microbiological diagnosis of BV, candidiasis and trichomoniasis, assessed by the kappa index, was 0.47, 0.23 and 0.28, respectively. CONCLUSION The most common cause of abnormal vaginal secretion was BV. The clinical evaluation of vaginal secretion presented amoderate to weak agreement with the microbiological diagnosis, indicating the need for complementary investigation of the clinical findings of abnormal vaginal secretion.

Secretion and activation of the Serratia marcescens hemolysin by structurally defined ShlB mutants.

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Pramanik, Avijit; Könninger, Ulrich; Selvam, Arun; Braun, Volkmar

2014-05-01

The ShlA hemolysin of Serratia marcescens is secreted across the outer membrane by the ShlB protein; ShlB belongs to the two-partner secretion system (type Vb), a subfamily of the Omp85 outer membrane protein assembly and secretion superfamily. During secretion, ShlA is converted from an inactive non-hemolytic form into an active hemolytic form. The structure of ShlB is predicted to consist of the N-terminal α-helix H1, followed by the two polypeptide-transport-associated domains POTRA P1 and P2, and the β-barrel of 16 β-strands. H1 is inserted into the pore of the β-barrel in the outer membrane; P1 and P2 are located in the periplasm. To obtain insights into the secretion and activation of ShlA by ShlB, we isolated ShlB mutants impaired in secretion and/or activation. The triple H1 P1 P2 mutant did not secrete ShlA. The P1 and P2 deletion derivatives secreted reduced amounts of ShlA, of which P1 showed some hemolysis, whereas P2 was inactive. Deletion of loop 6 (L6), which is conserved among exporters of the Omp85 family, compromised activation but retained low secretion. Secretion-negative mutants generated by random mutagenesis were located in loop 6. The inactive secreted ShlA derivatives were complemented in vitro to active ShlA by an N-terminal ShlA fragment (ShlA242) secreted by ShlB. Deletion of H1 did not impair secretion of hemolytic ShlA. The study defines domains of ShlB which are important for ShlA secretion and activation. Copyright © 2013 Elsevier GmbH. All rights reserved.

Competition of organic anions for furosemide and p-aminohippurate secretion in the rabbit

International Nuclear Information System (INIS)

Bidiville, J.; Roch-Ramel, F.

1986-01-01

The excretion of [ 14 C]- or [ 35 S]furosemide and [ 3 H]-p-aminohippurate (PAH) injected within 4 min into the left renal artery of rabbits was measured under brisk mannitol diuresis. The estimated rate of furosemide secretion during the first pass through the left kidney was lower than that of PAH when neither of the two transport processes were saturated: 7.9 and 12.9% of the total amounts injected were secreted per minute, respectively. Different competitive inhibitors were injected i.v. Probenecid (50 mg/kg) inhibited furosemide and PAH secretion by 95 and 80%, respectively. Pyrazinoate at plasma concentrations of 3 to 5 mM had no effect on either anion. Indomethacin (10 mg/kg) depressed furosemide secretion by 24% but had no effect on PAH secretion. PAH at a concentration of 9 to 17 mM in plasma depressed furosemide secretion by only 44 to 66%. Furosemide did not inhibit PAH secretion when infused into the left renal artery at a rate 5000 times higher than PAH. It was concluded that furosemide is secreted partly by the transport system secreting PAH, for which it had only a low affinity, and partly by a transport system for which indomethacin had some affinity. This latter transport system, in turn, differs from that secreting pyrazinoate. The furosemide-induced natriuresis, in both kidneys, was proportional to the urinary excretion rate of furosemide until the fractional excretion of Na+ reached an apparent maximum of 20 to 30%

Beta-amyloid peptides undergo regulated co-secretion with neuropeptide and catecholamine neurotransmitters.

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Toneff, Thomas; Funkelstein, Lydiane; Mosier, Charles; Abagyan, Armen; Ziegler, Michael; Hook, Vivian

2013-08-01

Beta-amyloid (Aβ) peptides are secreted from neurons, resulting in extracellular accumulation of Aβ and neurodegeneration of Alzheimer's disease. Because neuronal secretion is fundamental for the release of neurotransmitters, this study assessed the hypothesis that Aβ undergoes co-release with neurotransmitters. Model neuronal-like chromaffin cells were investigated, and results illustrate regulated, co-secretion of Aβ(1-40) and Aβ(1-42) with peptide neurotransmitters (galanin, enkephalin, and NPY) and catecholamine neurotransmitters (dopamine, norepinephrine, and epinephrine). Regulated secretion from chromaffin cells was stimulated by KCl depolarization and nicotine. Forskolin, stimulating cAMP, also induced co-secretion of Aβ peptides with peptide and catecholamine neurotransmitters. These data suggested the co-localization of Aβ with neurotransmitters in dense core secretory vesicles (DCSV) that store and secrete such chemical messengers. Indeed, Aβ was demonstrated to be present in DCSV with neuropeptide and catecholamine transmitters. Furthermore, the DCSV organelle contains APP and its processing proteases, β- and γ-secretases, that are necessary for production of Aβ. Thus, Aβ can be generated in neurotransmitter-containing DCSV. Human IMR32 neuroblastoma cells also displayed regulated secretion of Aβ(1-40) and Aβ(1-42) with the galanin neurotransmitter. These findings illustrate that Aβ peptides are present in neurotransmitter-containing DCSV, and undergo co-secretion with neuropeptide and catecholamine neurotransmitters that regulate brain functions. Copyright © 2013 Elsevier Inc. All rights reserved.

Cortisol Secretion and Change in Sleep Problems in Early Childhood: Moderation by Maternal Overcontrol

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Kiel, Elizabeth J.; Hummel, Alexandra C.; Luebbe, Aaron M.

2015-01-01

Childhood sleep problems are prevalent and relate to a wide range of negative psychological outcomes. However, it remains unclear how biological processes, such as HPA activity, may predict sleep problems over time in childhood in the context of certain parenting environments. Fifty-one mothers and their 18–20 month-old toddlers participated in a short-term longitudinal study assessing how shared variance among morning levels, diurnal change, and nocturnal change in toddlers’ cortisol secretion predicted change in sleep problems in the context of maternal overprotection and critical control. A composite characterized by low variability in, and, to a lesser extent, high morning values of cortisol, predicted increasing sleep problems from age 2 to age 3 when mothers reported high critical control. Results suggest value in assessing shared variance among different indices of cortisol secretion patterns and the interaction between cortisol and the environment in predicting sleep problems in early childhood. PMID:25766262

Uric Acid Secretion from Adipose Tissue and Its Increase in Obesity*

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Tsushima, Yu; Nishizawa, Hitoshi; Tochino, Yoshihiro; Nakatsuji, Hideaki; Sekimoto, Ryohei; Nagao, Hirofumi; Shirakura, Takashi; Kato, Kenta; Imaizumi, Keiichiro; Takahashi, Hiroyuki; Tamura, Mizuho; Maeda, Norikazu; Funahashi, Tohru; Shimomura, Iichiro

2013-01-01

Obesity is often accompanied by hyperuricemia. However, purine metabolism in various tissues, especially regarding uric acid production, has not been fully elucidated. Here we report, using mouse models, that adipose tissue could produce and secrete uric acid through xanthine oxidoreductase (XOR) and that the production was enhanced in obesity. Plasma uric acid was elevated in obese mice and attenuated by administration of the XOR inhibitor febuxostat. Adipose tissue was one of major organs that had abundant expression and activities of XOR, and adipose tissues in obese mice had higher XOR activities than those in control mice. 3T3-L1 and mouse primary mature adipocytes produced and secreted uric acid into culture medium. The secretion was inhibited by febuxostat in a dose-dependent manner or by gene knockdown of XOR. Surgical ischemia in adipose tissue increased local uric acid production and secretion via XOR, with a subsequent increase in circulating uric acid levels. Uric acid secretion from whole adipose tissue was increased in obese mice, and uric acid secretion from 3T3-L1 adipocytes was increased under hypoxia. Our results suggest that purine catabolism in adipose tissue could be enhanced in obesity. PMID:23913681

Effect of dietary roughage level on chewing activity, ruminal pH, and saliva secretion in lactating Holstein cows.

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Jiang, F G; Lin, X Y; Yan, Z G; Hu, Z Y; Liu, G M; Sun, Y D; Liu, X W; Wang, Z H

2017-04-01

Increasing dietary roughage level is a commonly used strategy to prevent subacute ruminal acidosis. We hypothesized that high-roughage diets could promote chewing activity, saliva secretion, and hence more alkaline to buffer rumen pH. To verify the hypothesis, 12 multiparous Holstein cows in mid lactation were randomly allocated to 4 treatments in a triplicated 4 × 4 Latin square experiment with one cow in each treatment surgically fitted with a ruminal cannula. Treatments were diets containing 40, 50, 60, or 70% of roughage on a DM basis. Increasing dietary roughage level decreased DM, CP, OM, starch, and NE L intake, increased ADF intake, and decreased milk yield linearly. Intake of NDF was quite stable across treatments and ranged from 7.8 to 8.1 kg/d per cow. Daily eating time increased linearly with increased roughage level. The increase in eating time was due to increased eating time per meal but not number of meals per day, which was stable and ranged from 8.3 to 8.5 meals per day across treatments. Increasing dietary roughage level had no effect on ruminating time (min/d), the number of ruminating periods (rumination periods per d), and chewing time per ruminating period (min/ruminating period). Ruminating time per kilogram of NDF intake and total chewing time per kilogram of ADF intake were similar across treatments (57.4 and 183.8 min/kg, respectively). Increasing dietary roughage level linearly increased daily total chewing time; linearly elevated the mean, maximum, and minimum ruminal pH; and linearly decreased total VFA concentration and molar proportion of propionate in ruminal fluid. Saliva secretion during eating was increased, the secretion during rumination was unaffected, but the secretion during resting tended to decrease with increased dietary roughage level. As a result, total saliva secretion was not affected by treatments. In conclusion, the results of the present study did not support the concept that high-roughage diets elevated ruminal p

Pirenzepine block of ACh-induced mucus secretion in tracheal submucosal gland cells

International Nuclear Information System (INIS)

Farley, J.M.; Dwyer, T.M.

1991-01-01

Muscarinic stimulation of mucus secretion, as measured by the release of [ 3 H]glycoprotein, was studied in explants from the tracheal epithelium of weanling swine. The mucus glycoprotein secretion was transient, ceasing within the first 10 min of a continuous exposure to 100 μM ACh. Increasing the solutions' osmotic pressure did not alter basal mucus glycoprotein secretion. Mucus glycoprotein secretion was inhibited by 2-10 μM PZP, indicting that the M 3 muscarinic receptors mediate cholinergic stimulation of mucus production

Ly108 expression distinguishes subsets of invariant NKT cells that help autoantibody production and secrete IL-21 from those that secrete IL-17 in lupus prone NZB/W mice.

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Tang, Xiaobin; Zhang, Bo; Jarrell, Justin A; Price, Jordan V; Dai, Hongjie; Utz, Paul J; Strober, Samuel

2014-05-01

Lupus is a systemic autoimmune disease characterized by anti-nuclear antibodies in humans and genetically susceptible NZB/W mice that can cause immune complex glomerulonephritis. T cells contribute to lupus pathogenesis by secreting pro-inflammatory cytokines such as IL-17, and by interacting with B cells and secreting helper factors such as IL-21 that promote production of IgG autoantibodies. In the current study, we determined whether purified NKT cells or far more numerous conventional non-NKT cells in the spleen of NZB/W female mice secrete IL-17 and/or IL-21 after TCR activation in vitro, and provide help for spontaneous IgG autoantibody production by purified splenic CD19(+) B cells. Whereas invariant NKT cells secreted large amounts of IL-17 and IL-21, and helped B cells, non-NKT cells did not. The subset of IL-17 secreting NZB/W NKT cells expressed the Ly108(lo)CD4(-)NK1.1(-) phenotype, whereas the IL-21 secreting subset expressed the Ly108(hi)CD4(+)NK1.1(-) phenotype and helped B cells secrete a variety of IgG anti-nuclear antibodies. α-galactocylceramide enhanced the helper activity of NZB/W and B6.Sle1b NKT cells for IgG autoantibody secretion by syngeneic B cells. In conclusion, different subsets of iNKT cells from mice with genetic susceptibility to lupus can contribute to pathogenesis by secreting pro-inflammatory cytokines and helping autoantibody production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intraoperative Magnetic Resonance Imaging During Endoscopic Transsphenoidal Surgery of Growth Hormone-Secreting Pituitary Adenomas.

Science.gov (United States)

Netuka, David; Májovský, Martin; Masopust, Václav; Belšán, Tomáš; Marek, Josef; Kršek, Michal; Hána, Václav; Ježková, Jana; Hána, Václav; Beneš, Vladimír

2016-07-01

The effect of intraoperative magnetic resonance imaging (iMRI) on the extent of sellar region tumors treated endonasally has been described in previous research. However, the effects of iMRI on endocrinologic outcome of growth hormone-secreting adenomas have been studied in only a few small cohort studies. Inclusion criteria were primary transsphenoidal surgery for growth hormone-secreting adenoma from January 2009 to December 2014, a minimum follow-up of 1 year, complete endocrinologic data, at least 1 iMRI, and at least 2 postoperative magnetic resonance images. The cohort consisted of 105 patients (54 females, 51 males) with a mean age of 48.3 years (range, 7-77 years). There were 16 microadenomas and 89 macroadenomas. Endocrinologic remission in the whole cohort was achieved in 64 of the patients (60.9%). Resection after iMRI was attempted in 22 of the cases (20.9%). Resection after iMRI led to hormonal remission in 9 cases (8.6%). Endocrinologic postoperative deficit was observed in 10 cases (12.5%). Postoperative cerebrospinal fluid leakage indicated the necessity to reoperate in 3 cases (3.8%). No neurologic deterioration was observed. iMRI influences not only the morphologic extent of pituitary adenomas resection but also the endocrinologic results. We encourage the routine application of iMRI in pituitary adenoma surgery, including hormone-secreting pituitary tumors. Copyright © 2016 Elsevier Inc. All rights reserved.

Comment on 'Quantum secret sharing between multiparty and multiparty without entanglement'

International Nuclear Information System (INIS)

Li, C.-M.; Hwang, T.; Chang, C.-C.

2006-01-01

Recently, Yan and Gao [Phys. Rev. A 72, 012304 (2005)] presented a quantum secret sharing protocol which allows a secret message to be shared between two groups of parties (m parties in group 1 and n parties in group 2). Their protocol is claimed to be secure that, except with the cooperation of the entire group 1 or group 2, no subgroup of either group 1 or group 2 can extract the secret message. However, this study points out that the mth party (the last party to process the quantum state) of group 1 can maliciously replace the secret message with an arbitrary message without the detection of the other parties

Behavior of temperature dependent SRAM-PUFs, and consequences for secret-key capacity

NARCIS (Netherlands)

Kusters, C.J.; Ignatenko, T.; Willems, F.M.J.

2017-01-01

Physical Unclonable Functions (PUFs) are a resource for generating and sharing secret keys. The mutual information between two respective observations of the same PUF gives an upper bound for the achievable secret-key rate of a secret-sharing scheme that relies on this PUF. This mutual information

Bottleneck in secretion of α-amylase in Bacillus subtilis.

Science.gov (United States)

Yan, Shaomin; Wu, Guang

2017-07-19

Amylase plays an important role in biotechnology industries, and Gram-positive bacterium Bacillus subtilis is a major host to produce heterogeneous α-amylases. However, the secretion stress limits the high yield of α-amylase in B. subtilis although huge efforts have been made to address this secretion bottleneck. In this question-oriented review, every effort is made to answer the following questions, which look simple but are long-standing, through reviewing of literature: (1) Does α-amylase need a specific and dedicated chaperone? (2) What signal sequence does CsaA recognize? (3) Does CsaA require ATP for its operation? (4) Does an unfolded α-amylase is less soluble than a folded one? (5) Does α-amylase aggregate before transporting through Sec secretion system? (6) Is α-amylase sufficient stable to prevent itself from misfolding? (7) Does α-amylase need more disulfide bonds to be stabilized? (8) Which secretion system does PrsA pass through? (9) Is PrsA ATP-dependent? (10) Is PrsA reused after folding of α-amylase? (11) What is the fate of PrsA? (12) Is trigger factor (TF) ATP-dependent? The literature review suggests that not only the most of those questions are still open to answers but also it is necessary to calculate ATP budget in order to better understand how B. subtilis uses its energy for production and secretion.

Adrenocorticotropic Hormone Secreting Pheochromocytoma Underlying Glucocorticoid Induced Pheochromocytoma Crisis

Directory of Open Access Journals (Sweden)

Gil A. Geva

2018-01-01

Full Text Available Context. Pheochromocytomas are hormone secreting tumors of the medulla of the adrenal glands found in 0.1–0.5% of patients with hypertension. The vast majority of pheochromocytomas secrete catecholamines, but they have been occasionally shown to also secrete interleukins, calcitonin, testosterone, and in rare cases adrenocorticotropic hormone. Pheochromocytoma crisis is a life threatening event in which high levels of catecholamines cause a systemic reaction leading to organ failure. Case Description. A 70-year-old man was admitted with acute myocardial ischemia following glucocorticoid administration as part of an endocrine workup for an adrenal mass. Cardiac catheterization disclosed patent coronary arteries and he was discharged. A year later he returned with similar angina-like chest pain. During hospitalization, he suffered additional events of chest pain, shortness of breath, and palpitations following administration of glucocorticoids as preparation for intravenous contrast administration. Throughout his admission, the patient demonstrated both signs of Cushing’s syndrome and high catecholamine levels. Following stabilization of vital parameters and serum electrolytes, the adrenal mass was resected surgically and was found to harbor an adrenocorticotropic hormone secreting pheochromocytoma. This is the first documented case of adrenocorticotropic hormone secreting pheochromocytoma complicated by glucocorticoid induced pheochromocytoma crisis. Conclusion. Care should be taken when administering high doses of glucocorticoids to patients with suspected pheochromocytoma, even in a patient with concomitant Cushing’s syndrome.

Analysis of in vitro secretion profiles from adipose-derived cell populations

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Blaber Sinead P

2012-08-01

Full Text Available Abstract Background Adipose tissue is an attractive source of cells for therapeutic purposes because of the ease of harvest and the high frequency of mesenchymal stem cells (MSCs. Whilst it is clear that MSCs have significant therapeutic potential via their ability to secrete immuno-modulatory and trophic cytokines, the therapeutic use of mixed cell populations from the adipose stromal vascular fraction (SVF is becoming increasingly common. Methods In this study we have measured a panel of 27 cytokines and growth factors secreted by various combinations of human adipose-derived cell populations. These were 1. co-culture of freshly isolated SVF with adipocytes, 2. freshly isolated SVF cultured alone, 3. freshly isolated adipocytes alone and 4. adherent adipose-derived mesenchymal stem cells (ADSCs at passage 2. In addition, we produced an ‘in silico’ dataset by combining the individual secretion profiles obtained from culturing the SVF with that of the adipocytes. This was compared to the secretion profile of co-cultured SVF and adipocytes. Two-tailed t-tests were performed on the secretion profiles obtained from the SVF, adipocytes, ADSCs and the ‘in silico’ dataset and compared to the secretion profiles obtained from the co-culture of the SVF with adipocytes. A p-value of  Results A co-culture of SVF and adipocytes results in a distinct secretion profile when compared to all other adipose-derived cell populations studied. This illustrates that cellular crosstalk during co-culture of the SVF with adipocytes modulates the production of cytokines by one or more cell types. No biologically relevant differences were detected in the proteomes of SVF cultured alone or co-cultured with adipocytes. Conclusions The use of mixed adipose cell populations does not appear to induce cellular stress and results in enhanced secretion profiles. Given the importance of secreted cytokines in cell therapy, the use of a mixed cell population such as the

Two-partner secretion systems of Neisseria meningitidis associated with invasive clonal complexes

NARCIS (Netherlands)

van Ulsen, Peter; Rutten, Lucy; Feller, Moniek; Tommassen, Jan; van der Ende, Arie

2008-01-01

The two-partner secretion (TPS) pathway is widespread among gram-negative bacteria and facilitates the secretion of very large and often virulence-related proteins. TPS systems consist of a secreted TpsA protein and a TpsB protein involved in TpsA transport across the outer membrane. Sequenced

Regulated Mucin Secretion from Airway Epithelial Cells

Directory of Open Access Journals (Sweden)

Kenneth Bruce Adler

2013-09-01

Full Text Available Secretory epithelial cells of the proximal airways synthesize and secrete gel-forming polymeric mucins. The secreted mucins adsorb water to form mucus that is propelled by neighboring ciliated cells, providing a mobile barrier which removes inhaled particles and pathogens from the lungs. Several features of the intracellular trafficking of mucins make the airway secretory cell an interesting comparator for the cell biology of regulated exocytosis. Polymeric mucins are exceedingly large molecules (up to 3x10^6 D per monomer whose folding and initial polymerization in the ER requires the protein disulfide isomerase Agr2. In the Golgi, mucins further polymerize to form chains and possibly branched networks comprising more than 20 monomers. The large size of mucin polymers imposes constraints on their packaging into transport vesicles along the secretory pathway. Sugar side chains account for >70% of the mass of mucins, and their attachment to the protein core by O-glycosylation occurs in the Golgi. Mature polymeric mucins are stored in large secretory granules ~1 um in diameter. These are translocated to the apical membrane to be positioned for exocytosis by cooperative interactions among MARCKS, cysteine string protein (CSP, HSP70 and the cytoskeleton. Mucin granules undergo exocytic fusion with the plasma membrane at a low basal rate and a high stimulated rate. Both rates are mediated by a regulated exocytic mechanism as indicated by phenotypes in both basal and stimulated secretion in mice lacking Munc13-2, a sensor of the second messengers calcium and diacylglycerol (DAG. Basal secretion is induced by low levels of activation of P2Y2 purinergic and A3 adenosine receptors by extracellular ATP released in paracrine fashion and its metabolite adenosine. Stimulated secretion is induced by high levels of the same ligands, and possibly by inflammatory mediators as well. Activated receptors are coupled to phospholipase C by Gq, resulting in the

Impaired insulin secretion and glucose intolerance in synaptotagmin-7 null mutant mice

DEFF Research Database (Denmark)

Gustavsson, Natalia; Lao, Ye; Maximov, Anton

2008-01-01

and insulin release. Here, we show that synaptotagmin-7 is required for the maintenance of systemic glucose tolerance and glucose-stimulated insulin secretion. Mutant mice have normal insulin sensitivity, insulin production, islet architecture and ultrastructural organization, and metabolic and calcium...... secretion in pancreatic beta-cells. Of these other synaptotagmins, synaptotagmin-7 is one of the most abundant and is present in pancreatic beta-cells. To determine whether synaptotagmin-7 regulates Ca(2+)-dependent insulin secretion, we analyzed synaptotagmin-7 null mutant mice for glucose tolerance...... responses but exhibit impaired glucose-induced insulin secretion, indicating a calcium-sensing defect during insulin-containing secretory granule exocytosis. Taken together, our findings show that synaptotagmin-7 functions as a positive regulator of insulin secretion and may serve as a calcium sensor...

Heterogeneity and compartmental properties of insulin storage and secretion in rat islets

International Nuclear Information System (INIS)

Gold, G.; Landahl, H.D.; Gishizky, M.L.; Grodsky, G.M.

1982-01-01

To investigate compartmental properties of insulin storage and secretion, isolated rat islets were used for pulse-labeling experiments, after which proinsulin and insulin were purified rigorously. Processing of proinsulin to insulin neared completion by 3 h without additional loss of either radioactive peptide by cellular or extracellular proteolysis. The amount of labeled hormone rapidly diminished in islets; it was secreted at a higher fractional rate than immunoreactive insulin, resulting in secreted insulin's having a higher specific activity than the average cellular insulin. Newly synthesized insulin, therefore, was secreted preferentially. Changes in the specific activity of secreted and cellular insulin with time were consistent with changes predicted for islets containing 33% of their total insulin in a glucose-labile compartment. Predictions were based on steady-state analysis of a simple storage-limited representation of B cell function. Islets from either the dorsal or ventral part of the pancreas also contained 33% of their total insulin in a glucose-labile compartment. The same compartment was mobilized by 20 mM glucose, 50 mM potassium + 2 mM glucose, or 20 MM glucose + 1 mM 3-isobutylmethylxanthine as indicated by the specific activity ratio of secreted vs. cellular insulin, even though average secretion rates with these stimuli differed by more than threefold. In the absence of calcium, the effectiveness of 20 mM glucose as a secretagogue declined markedly, and the older stored insulin was preferentially mobilized because secreted insulin had a lower rather than a higher specific activity than cellular insulin. Results provide insight into the mechanisms of nonrandom mobilization and secretion of insulin form the B cell

Activated platelets enhance IL-10 secretion and reduce TNF-α secretion by monocytes

DEFF Research Database (Denmark)

Gudbrandsdottir, Sif; Hasselbalch, Hans C; Nielsen, Claus H

2013-01-01

), Escherichia coli LPS, or intact Porphyromonas gingivalis. Addition of platelets activated by thrombin-receptor-activating peptide enhanced IL-10 production induced by LPS (p gingivalis (p ....05), and P. gingivalis (p gingivalis-stimulated cultures (p ... of activated platelets. Adherence of platelets increased TG- and TT-induced IL-10 secretion by monocytes (p gingivalis (p

Exosome secretion by eosinophils: A possible role in asthma pathogenesis.

Science.gov (United States)

Mazzeo, Carla; Cañas, José Antonio; Zafra, Maria Paz; Rojas Marco, Ainara; Fernández-Nieto, Mar; Sanz, Veronica; Mittelbrunn, María; Izquierdo, Manuel; Baixaulli, Francesc; Sastre, Joaquín; Del Pozo, Victoria

2015-06-01

Eosinophils secrete several granules that are involved in the propagation of inflammatory responses in patients with pathologies such as asthma. We hypothesized that some of these granules are exosomes, which, when transferred to the recipient cells, could modulate asthma progression. Eosinophils were purified from peripheral blood and cultured with or without IFN-γ or eotaxin. Multivesicular bodies (MVBs) in eosinophils were studied by using fluorescence microscopy, transmission electron microscopy (TEM), and flow cytometry. Exosome secretion was measured and exosome characterization was performed with TEM, Western blotting, and NanoSight analysis. Generation of MVBs in eosinophils was confirmed by using fluorescence microscopy and flow cytometry and corroborated by means of TEM. Having established that eosinophils contain MVBs, our aim was to demonstrate that eosinophils secrete exosomes. To do this, we purified exosomes from culture medium of eosinophils and characterized them. Using Western blot analysis, we demonstrated that eosinophils secreted exosomes and that the discharge of exosomes to extracellular media increases after IFN-γ stimulation. We measured exosome size and quantified exosome production from healthy and asthmatic subjects using nanotracking analysis. We found that exosome production was augmented in asthmatic patients. Our findings are the first to demonstrate that eosinophils contain functional MVBs and secrete exosomes and that their secretion is increased in asthmatic patients. Thus exosomes might play an important role in the progression of asthma and eventually be considered a biomarker. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The dynamics of secretion during sea urchin embryonic skeleton formation

International Nuclear Information System (INIS)

Wilt, Fred H.; Killian, Christopher E.; Hamilton, Patricia; Croker, Lindsay

2008-01-01

Skeleton formation involves secretion of massive amounts of mineral precursor, usually a calcium salt, and matrix proteins, many of which are deposited on, or even occluded within, the mineral. The cell biological underpinnings of this secretion and subsequent assembly of the biomineralized skeletal element is not well understood. We ask here what is the relationship of the trafficking and secretion of the mineral and matrix within the primary mesenchyme cells of the sea urchin embryo, cells that deposit the endoskeletal spicule. Fluorescent labeling of intracellular calcium deposits show mineral precursors are present in granules visible by light microscopy, from whence they are deposited in the endoskeletal spicule, especially at its tip. In contrast, two different matrix proteins tagged with GFP are present in smaller post-Golgi vesicles only seen by electron microscopy, and the secreted protein are only incorporated into the spicule in the vicinity of the cell of origin. The matrix protein, SpSM30B, is post-translationally modified during secretion, and this processing continues after its incorporation into the spicule. Our findings also indicate that the mineral precursor and two well characterized matrix proteins are trafficked by different cellular routes

Peptidomic analysis of skin secretions supports separate species status for the tailed frogs, Ascaphus truei and Ascaphus montanus

Science.gov (United States)

Conlon, J.M.; Bevier, C.R.; Coquet, L.; Leprince, J.; Jouenne, T.; Vaudry, H.; Hossack, B.R.

2007-01-01

The tailed frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue and Wallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the products of orthologous ascaphin genes in electrically-stimulated skin secretions from inland range specimens. Structural characterization of the peptides demonstrated that ascaphins from the inland range contained the following amino acid substitutions compared with orthologs from the coastal range frogs: ascaphin-1 (Ala12 → Glu), ascaphin-3 (Asp4 → Glu), ascaphin-4 (Ala19 → Ser), ascaphin-5 (Lys12 → Thr), and ascaphin-7 (Gly8 → Ser and Ser20 → Asn). Orthologs of ascaphins-2, -6, and -8 were not identified but a paralog of ascaphin-5, identical to ascaphin-5 from coastal range frogs, was found. The data support the claims, derived from analysis of the nucleotide sequences of mitochondrial genes, that the inland populations of the tailed frog should be recognized as a distinct species, the Rocky Mountain tailed frog Ascaphus montanus and that the divergence of the species from A. truei probably occurred in the late Miocene (approximately 10 Mya).

Secret Key Agreement: Fundamental Limits and Practical Challenges

KAUST Repository

Rezki, Zouheir

2017-02-15

Despite the tremendous progress made toward establishing PLS as a new paradigm to guarantee security of communication systems at the physical layerthere is a common belief among researchers and industrials that there are many practical challenges that prevent PLS from flourishing at the industrial scale. Most secure message transmission constructions available to date are tied to strong assumptions on CSI, consider simple channel models and undermine eavesdropping capabilities; thus compromising their practical interest to a big extent. Perhaps arguably, the most likely reasonable way to leverage PLS potential in securing modern wireless communication systems is via secret-key agreement. In the latter setting, the legitimate parties try to agree on a key exploiting availability of a public channel with high capacity which is also accessible to the eavesdropper. Once a key is shared by the legitimate parties, they may use it in a one-time pad encryption, for instance. In this article, we investigate two performance limits of secret-key agreement communications; namely, the secret-key diversity-multiplexing trade-off and the effect of transmit correlation on the secretkey capacity. We show via examples how secretkey agreement offers more flexibility than secure message transmissions. Finally, we explore a few challenges of secret-key agreement concept and propose a few guidelines to overturn them.

A Phytase-Based Reporter System for Identification of Functional Secretion Signals in Bifidobacteria

Science.gov (United States)

Osswald, Annika; Westermann, Christina; Sun, Zhongke; Riedel, Christian U.

2015-01-01

Health-promoting effects have been attributed to a number of Bifidobacterium sp. strains. These effects as well as the ability to colonise the host depend on secreted proteins. Moreover, rational design of protein secretion systems bears the potential for the generation of novel probiotic bifidobacteria with improved health-promoting or therapeutic properties. To date, there is only very limited data on secretion signals of bifidobacteria available. Using in silico analysis, we demonstrate that all bifidobacteria encode the major components of Sec-dependent secretion machineries but only B. longum strains harbour Tat protein translocation systems. A reporter plasmid for secretion signals in bifidobacteria was established by fusing the coding sequence of the signal peptide of a sialidase of Bifidobacterium bifidum S17 to the phytase gene appA of E. coli. The recombinant strain showed increased phytase activity in spent culture supernatants and reduced phytase levels in crude extracts compared to the control indicating efficient phytase secretion. The reporter plasmid was used to screen seven predicted signal peptides in B. bifidum S17 and B. longum E18. The tested signal peptides differed substantially in their efficacy to mediate protein secretion in different host strains. An efficient signal peptide was used for expression and secretion of a therapeutically relevant protein in B. bifidum S17. Expression of a secreted cytosine deaminase led to a 100-fold reduced sensitivity of B. bifidum S17 to 5-fluorocytosine compared to the non-secreted cytosine deaminase suggesting efficient conversion of 5-fluorocytosine to the cytotoxic cancer drug 5-fluorouracil by cytosine deaminase occurred outside the bacterial cell. Selection of appropriate signal peptides for defined protein secretion might improve therapeutic efficacy as well as probiotic properties of bifidobacteria. PMID:26086721

A Phytase-Based Reporter System for Identification of Functional Secretion Signals in Bifidobacteria.

Directory of Open Access Journals (Sweden)

Annika Osswald

Full Text Available Health-promoting effects have been attributed to a number of Bifidobacterium sp. strains. These effects as well as the ability to colonise the host depend on secreted proteins. Moreover, rational design of protein secretion systems bears the potential for the generation of novel probiotic bifidobacteria with improved health-promoting or therapeutic properties. To date, there is only very limited data on secretion signals of bifidobacteria available. Using in silico analysis, we demonstrate that all bifidobacteria encode the major components of Sec-dependent secretion machineries but only B. longum strains harbour Tat protein translocation systems. A reporter plasmid for secretion signals in bifidobacteria was established by fusing the coding sequence of the signal peptide of a sialidase of Bifidobacterium bifidum S17 to the phytase gene appA of E. coli. The recombinant strain showed increased phytase activity in spent culture supernatants and reduced phytase levels in crude extracts compared to the control indicating efficient phytase secretion. The reporter plasmid was used to screen seven predicted signal peptides in B. bifidum S17 and B. longum E18. The tested signal peptides differed substantially in their efficacy to mediate protein secretion in different host strains. An efficient signal peptide was used for expression and secretion of a therapeutically relevant protein in B. bifidum S17. Expression of a secreted cytosine deaminase led to a 100-fold reduced sensitivity of B. bifidum S17 to 5-fluorocytosine compared to the non-secreted cytosine deaminase suggesting efficient conversion of 5-fluorocytosine to the cytotoxic cancer drug 5-fluorouracil by cytosine deaminase occurred outside the bacterial cell. Selection of appropriate signal peptides for defined protein secretion might improve therapeutic efficacy as well as probiotic properties of bifidobacteria.

Improvement of Secret Image Invisibility in Circulation Image with Dyadic Wavelet Based Data Hiding with Run-Length Coded Secret Images of Which Location of Codes are Determined with Random Number

OpenAIRE

Kohei Arai; Yuji Yamada

2011-01-01

An attempt is made for improvement of secret image invisibility in circulation images with dyadic wavelet based data hiding with run-length coded secret images of which location of codes are determined by random number. Through experiments, it is confirmed that secret images are almost invisible in circulation images. Also robustness of the proposed data hiding method against data compression of circulation images is discussed. Data hiding performance in terms of invisibility of secret images...

Quantum secret information equal exchange protocol based on dense coding

Science.gov (United States)

Jiang, Ying-Hua; Zhang, Shi-Bin; Dai, Jin-Qiao; Shi, Zhi-Ping

2018-04-01

In this paper, we design a novel quantum secret information equal exchange protocol, which implements the equal exchange of secret information between the two parties with the help of semi-trusted third party (TP). In the protocol, EPR pairs prepared by the TP are, respectively, distributed to both the communication parties. Then, the two parties perform Pauli operation on each particle and return the new particles to TP, respectively. TP measures each new pair with Bell basis and announces the measurement results. Both parties deduce the secret information of each other according to the result of announcement by TP. Finally, the security analysis shows that this protocol solves the problem about equal exchange of secret information between two parties and verifies the security of semi-trusted TPs. It proves that the protocol can effectively resist glitch attacks, intercept retransmission attacks and entanglement attack.

The teacher-disciple tradition and secret teaching in Chinese medicine.

Science.gov (United States)

Solos, Ioannis; Liang, Yuan; Yue, Guang-xin

2014-01-01

The ancient teacher-disciple tradition is regarded as one of the most celebrated practices within the Chinese medicine world. Such traditions of secrecy, private wisdom and honor are deeply rooted in the theories of Confucianism. This paper only explores the surface of this ancient culture, by investigating relevant popular ancient texts and common Chinese proverbs, as well as utilizing personal experiences, in order to reflect on how the ancient Chinese perceived such practices within their own society and how secret teaching was passed on from teacher to student, including the revelation of secret formulas and their importance and how that tradition differs from our modern-day perspectives. Various rare manuscripts from the author's personal library are employed in order to provide relative examples of the importance of secret knowledge, and how these secrets applied in the traditional healing.

Systematic high-yield production of human secreted proteins in Escherichia coli

International Nuclear Information System (INIS)

Dai Xueyu; Chen Qiang; Lian Min; Zhou Yanfeng; Zhou Mo; Lu Shanyun; Chen Yunjia; Luo Jingchu; Gu Xiaocheng; Jiang Ying; Luo Ming; Zheng Xiaofeng

2005-01-01

Human secreted proteins play a very important role in signal transduction. In order to study all potential secreted proteins identified from the human genome sequence, systematic production of large amounts of biologically active secreted proteins is a prerequisite. We selected 25 novel genes as a trial case for establishing a reliable expression system to produce active human secreted proteins in Escherichia coli. Expression of proteins with or without signal peptides was examined and compared in E. coli strains. The results indicated that deletion of signal peptides, to a certain extent, can improve the expression of these proteins and their solubilities. More importantly, under expression conditions such as induction temperature, N-terminus fusion peptides need to be optimized in order to express adequate amounts of soluble proteins. These recombinant proteins were characterized as well-folded proteins. This system enables us to rapidly obtain soluble and highly purified human secreted proteins for further functional studies

Authenticated quantum secret sharing with quantum dialogue based on Bell states

International Nuclear Information System (INIS)

Abulkasim, Hussein; Hamad, Safwat; El Bahnasy, Khalid; Rida, Saad Z

2016-01-01

This work proposes a scheme that combines the advantages of a quantum secret sharing procedure and quantum dialogue. The proposed scheme enables the participants to simultaneously make mutual identity authentications, in a simulated scenario where the boss, Alice, shares a secret with her two agents Bob and Charlie. The secret is protected by checking photons to keep untrustworthy agents and outer attacks from getting useful information. Before the two agents cooperate to recover Alice’s secret, they must authenticate their identity using parts of a pre-shared key. In addition, the whole pre-shared key is reused as part of recovering the secret data to avoid any leaks of information. In comparison with previous schemes, the proposed method can efficiently detect eavesdropping and it is free from information leaks. Furthermore, the proposed scheme proved to be secure against man-in-the-middle attacks, impersonation attacks, entangled-and-measure attacks, participant attacks, modification attacks and Trojan-horse attacks. (paper)

Associations Between Secret-Keeping and Quality of Life in Older Adults.

Science.gov (United States)

Maas, Joyce; Wismeijer, Andreas A J; Van Assen, Marcel A L M

2018-01-01

This study examined the effects of secrecy on quality of life in a sample consisting of older adults (>50 years; N = 301). Three key components of secrecy were examined with the Tilburg Secrecy Scale-25 (TSS25; possession of a secret, self-concealment, and cognitive preoccupation). The TSS25 distinguishes between the tendency to conceal personal information (self-concealment) and the tendency to worry or ruminate about the secret (cognitive preoccupation), thereby enabling investigation of the effects of secrecy on quality of life in detail. Confirming previous findings in younger samples, we found a positive effect of possession of a secret on quality of life, after controlling for both TSS25's self-concealment and cognitive preoccupation. This suggests that keeping secrets may have a positive association with quality of life in older adults as well, as long as they do not have the tendency to self-conceal and are not cognitively preoccupied with their secret.

Secret Sharing over Fast-Fading MIMO Wiretap Channels

Directory of Open Access Journals (Sweden)

Bloch Matthieu

2009-01-01

Full Text Available Secret sharing over the fast-fading MIMO wiretap channel is considered. A source and a destination try to share secret information over a fast-fading MIMO channel in the presence of an eavesdropper who also makes channel observations that are different from but correlated to those made by the destination. An interactive, authenticated public channel with unlimited capacity is available to the source and destination for the secret sharing process. This situation is a special case of the "channel model with wiretapper" considered by Ahlswede and Csiszár. An extension of their result to continuous channel alphabets is employed to evaluate the key capacity of the fast-fading MIMO wiretap channel. The effects of spatial dimensionality provided by the use of multiple antennas at the source, destination, and eavesdropper are then investigated.

GLUT2 and the incretin receptors are involved in glucose-induced incretin secretion

DEFF Research Database (Denmark)

Cani, Patrice D; Holst, Jens Juul; Drucker, Daniel J

2007-01-01

to those described for beta-cells, brain and hepatoportal sensors. We determined the role of GLUT2, GLP-1 or GIP receptors in glucose-induced incretins secretion, in the corresponding knockout mice. GLP-1 secretion was reduced in all mutant mice, while GIP secretion did not require GLUT2. Intestinal GLP-1...... content was reduced only in GIP and GLUT2 receptors knockout mice suggesting that this impairment could contribute to the phenotype. Intestinal GIP content was similar in all mice studied. Furthermore, the impaired incretins secretion was associated with a reduced glucose-stimulated insulin secretion...

Mucus glycoprotein secretion by tracheal explants: effects of pollutants

International Nuclear Information System (INIS)

Last, J.A.; Kaizu, T.

1980-01-01

Tracheal slices incubated with radioactive precursors in tissue culture medium secrete labeled mucus glycoproteins into the culture medium. We have used an in vivtro approach, a combined method utilizing exposure to pneumotoxins in vivo coupled with quantitation of mucus secretion rates in vitro, to study the effects of inhaled pollutants on mucus biosynthesis by rat airways. In addition, we have purified the mucus glycoproteins secreted by rat tracheal explants in order to determine putative structural changes that might by the basis for the observed augmented secretion rates after exposure of rats to H2SO4 aerosols in combination with high ambient levels of ozone. After digestion with papain, mucus glycoproteins secreted by tracheal explants may be separated into five fractions by ion-exchange chromatography, with recovery in high yield, on columns of DEAE-cellulose. Each of these five fractions, one neutral and four acidic, migrates as a single unique spot upon cellulose acetate electrophoresis at pH values of 8.6 and 1.2. The neutral fraction, which is labeled with [3H] glucosamine, does not contain radioactivity when Na2 35SO4 is used as the precursor. Acidic fractions I to IV are all labeled with either 3H-glucosamine or Na2 35SO4 as precursor. Acidic fraction II contains sialic acid as the terminal sugar on its oligosaccharide side chains, based upon its chromatographic behavior on columns of wheat-germ agglutinin-Agarose. Treatment of this fraction with neuraminidase shifts its elution position in the gradient to a lower salt concentration, coincident with acidic fraction I. After removal of terminal sialic acid residues with either neuraminidase or low pH treatment, the resultant terminal sugar on the oligosaccharide side chains is fucose. These results are identical with those observed with mucus glycoproteins secreted by cultured human tracheal explants and purified by these same techniques

The role of women's secret societies in cameroon's contemporary ...

African Journals Online (AJOL)

Although there are many secret societies, most of which belong to the male folk in the North West Province of Cameroon, little was and/or is known about their activities. However, Takumbeng, a women's secret society from the North West Province of Cameroon came to prominence in the 1990's during the political upheaval ...

Momordica charantia Administration Improves Insulin Secretion in Type 2 Diabetes Mellitus.

Science.gov (United States)

Cortez-Navarrete, Marisol; Martínez-Abundis, Esperanza; Pérez-Rubio, Karina G; González-Ortiz, Manuel; Villar, Miriam Méndez-Del

2018-02-12

An improvement in parameters of glycemic control has been observed with Momordica charantia in patients with type 2 diabetes mellitus (T2DM). It is unknown whether this improvement is through a modification of insulin secretion, insulin sensitivity, or both. We hypothesized that M. charantia administration can improve insulin secretion and/or insulin sensitivity in patients with T2DM, without pharmacological treatment. The objective of the study was to evaluate the effect of M. charantia administration on insulin secretion and sensitivity. A randomized, double-blinded, placebo-controlled, clinical trial was carried out in 24 patients who received M. charantia (2000 mg/day) or placebo for 3 months. A 2-h oral glucose tolerance test (OGTT) was done before and after the intervention to calculate areas under the curve (AUC) of glucose and insulin, total insulin secretion (insulinogenic index), first phase of insulin secretion (Stumvoll index), and insulin sensitivity (Matsuda index). In the M. charantia group, there were significant decreases in weight, body mass index (BMI), fat percentage, waist circumference (WC), glycated hemoglobin A1c (A1C), 2-h glucose in OGTT, and AUC of glucose. A significant increase in insulin AUC (56,562 ± 36,078 vs. 65,256 ± 42,720 pmol/L/min, P = .043), in total insulin secretion (0.29 ± 0.18 vs. 0.41 ± 0.29, P = .028), and during the first phase of insulin secretion (557.8 ± 645.6 vs. 1135.7 ± 725.0, P = .043) was observed after M. charantia administration. Insulin sensitivity was not modified with any intervention. In conclusion, M. charantia administration reduced A1C, 2-h glucose, glucose AUC, weight, BMI, fat percentage, and WC, with an increment of insulin AUC, first phase and total insulin secretion.

Incidence and prognostic value of serotonin secretion in pancreatic neuroendocrine tumours.

Science.gov (United States)

Zandee, Wouter T; van Adrichem, Roxanne C; Kamp, Kimberly; Feelders, Richard A; van Velthuysen, Marie-Louise F; de Herder, Wouter W

2017-08-01

Serotonin secretion occurs in approximately 1%-4% of patients with a pancreatic neuroendocrine tumour (PNET), but the incidence is not well defined. The aim of this study was to determine the incidence of serotonin secretion with and without carcinoid syndrome and the prognostic value for overall survival (OS). Data were collected from 255 patients with a PNET if 24-hours urinary 5-hydroxyindoleacetic acid excretion (5-HIAA) was assessed. Patients were diagnosed with serotonin secretion if 24-hours urinary 5-HIAA excretion was more than 3× the upper limit of normal (ULN) of 50 μmol/24 hours during follow-up. The effect of serotonin secretion on OS was estimated with uni- and multivariate analyses using a Cox regression. Two (0.8%) patients were diagnosed with carcinoid syndrome, and another 20 (7.8%) had a serotonin-secreting PNET without symptoms. These patients mostly had ENETS stage IV disease with high chromogranin A (CgA). Serotonin secretion was a negative prognostic factor in univariate analysis (HR 2.2, 95% CI: 1.27-3.81), but in multivariate analysis, only CgA>10× ULN (HR: 1.81, 95% CI: 1.10-2.98) and neuron-specific enolase (NSE) >ULN (HR: 3.51, 95% CI: 2.26-5.46) were predictors for OS. Immunohistochemical staining for serotonin was positive in 28.6% of serotonin-secreting PNETs (one with carcinoid syndrome) and negative in all controls. Carcinoid syndrome is rare in patients with a PNET, but serotonin secretion occurs often. This is a negative prognostic factor for OS, but after correction for CgA and NSE, it is no longer a predictor and probably only a "not-so innocent bystander" in patients with high tumour burden. © 2017 John Wiley & Sons Ltd.

Sec-mediated secretion of bacteriocin enterocin P by Lactococcus lactis

NARCIS (Netherlands)

Herranz, C; Driessen, AJM

Most lactic acid bacterium bacteriocins utilize specific leader peptides and dedicated machineries for secretion. In contrast, the enterococcal bacteriocin enterocin P (EntP) contains a typical signal peptide that directs its secretion when heterologously expressed in Lactococcus lactis. Signal

Device-independent secret-key-rate analysis for quantum repeaters

Science.gov (United States)

Holz, Timo; Kampermann, Hermann; Bruß, Dagmar

2018-01-01

The device-independent approach to quantum key distribution (QKD) aims to establish a secret key between two or more parties with untrusted devices, potentially under full control of a quantum adversary. The performance of a QKD protocol can be quantified by the secret key rate, which can be lower bounded via the violation of an appropriate Bell inequality in a setup with untrusted devices. We study secret key rates in the device-independent scenario for different quantum repeater setups and compare them to their device-dependent analogon. The quantum repeater setups under consideration are the original protocol by Briegel et al. [Phys. Rev. Lett. 81, 5932 (1998), 10.1103/PhysRevLett.81.5932] and the hybrid quantum repeater protocol by van Loock et al. [Phys. Rev. Lett. 96, 240501 (2006), 10.1103/PhysRevLett.96.240501]. For a given repeater scheme and a given QKD protocol, the secret key rate depends on a variety of parameters, such as the gate quality or the detector efficiency. We systematically analyze the impact of these parameters and suggest optimized strategies.

Lipoidal Labellar Secretions in Maxillaria Ruiz & Pav. (Orchidaceae)

OpenAIRE

DAVIES, K. L.; TURNER, M. P.; GREGG, A.

2003-01-01

The labella of Maxillaria acuminata Lindl., M. cerifera Barb. Rodr. and M. notylioglossa Rchb.f., all members of the M. acuminata alliance, produce a viscid wax‐like secretion. Histochemical analysis revealed that the chemical composition of the secretion is similar in all three species, consisting largely of lipid and protein. Light microscopy and low‐vacuum scanning electron microscopy were used to investigate the secretory process. In a fourth taxon, M. cf. notylioglossa, transmission elec...

Lifestyle, mental health status and salivary secretion rates

OpenAIRE

Toda, Masahiro; Morimoto, Kanehisa; Fukuda, Sanae; Hayakawa, Kazuo

2002-01-01

The relations between salivary variables, lifestyle and mental health status were investigated for 61 healthy female university students. The salivary secretion rates were significantly higher in the good lifestyle groups compared with the poor lifestyle groups. Among the 8 lifestyle items tested. “eating breakfast” and “mental stress” were significantly related to the salivary secretion rates. The present findings suggest that the acquisition of a good lifestyle is also very important from t...

Cryptanalysis of Multiparty Quantum Secret Sharing of Quantum State Using Entangled States

International Nuclear Information System (INIS)

Su-Juan, Qin; Qiao-Yan, Wen; Fu-Chen, Zhu

2008-01-01

Security of a quantum secret sharing of quantum state protocol proposed by Guo et al. [Chin. Phys. Lett. 25 (2008) 16] is reexamined. It is shown that an eavesdropper can obtain some of the transmitted secret information by monitoring the classical channel or the entire secret by intercepting the quantum states, and moreover, the eavesdropper can even maliciously replace the secret message with an arbitrary message without being detected. Finally, the deep reasons why an eavesdropper can attack this protocol are discussed and the modified protocol is presented to amend the security loopholes

Multiparty quantum secret sharing of classical messages based on entanglement swapping

International Nuclear Information System (INIS)

Zhang Zhanjun; Man Zhongxiao

2005-01-01

A multiparty quantum secret sharing (QSS) protocol of classical messages (i.e., classical bits) is proposed by using swapping quantum entanglement of Bell states. The secret messages are imposed on Bell states by local unitary operations. The secret messages are split into several parts, and each part is distributed to a separate party so that no action of a subset of all the parties without the cooperation of the entire group is able to read out the secret messages. In addition, dense coding is used in this protocol to achieve a high efficiency. The security of the present multiparty QSS against eavesdropping has been analyzed and confirmed even in a noisy quantum channel

Ectosomes: a new mechanism for non-exosomal secretion of tau protein.

Directory of Open Access Journals (Sweden)

Simon Dujardin

Full Text Available Tau is a microtubule-associated protein that aggregates in neurodegenerative disorders known as tauopathies. Recently, studies have suggested that Tau may be secreted and play a role in neural network signalling. However, once deregulated, secreted Tau may also participate in the spreading of Tau pathology in hierarchical pathways of neurodegeneration. The mechanisms underlying neuron-to-neuron Tau transfer are still unknown; given the known role of extra-cellular vesicles in cell-to-cell communication, we wondered whether these vesicles could carry secreted Tau. We found, among vesicles, that Tau is predominately secreted in ectosomes, which are plasma membrane-originating vesicles, and when it accumulates, the exosomal pathway is activated.

Proteins are secreted from heterogeneous prestored sources in the exocrine pancreas

International Nuclear Information System (INIS)

Miller, P.E.; Adelson, J.W.

1987-01-01

Recent studies demonstrating nonparallel regulated secretion of prestored digestive enzymes in tightly linked groups consistent with the exocytosis mechanisms led the authors to predict that digestive enzymes would be found to be secreted from heterogeneous sources within the exocrine pancreas. They explored whether the gland was heterogeneous with respect to its sources of prestored secretory proteins with a double isotopic label method not dependent on activity of secreted digestive enzymes. Rabbit pancreatic proteins were double labeled in vivo by injection of each animal with chemically identical but isotopically distinct mixtures of 3 H- and 14 C-labeled amino acids, which were administered separately or together on consecutive days after partial depletion of prestored proteins by administration of cholecystokinin (CCK), methacholine chloride, or saline in a protocol in which order of both isotope and secretagogue administration was varied. Three days after labeling, proteins were recovered by collection from cannulated pancreatic ducts of anesthetized animals after stimulation with alternating increasing doses of CCK and methacholine chloride. Correlation and regression analysis of isotopic outputs and variance analysis of specific radioactivities of secreted proteins showed sequestration into and secretion from heterogeneous pools of secretory proteins, directly confirming the hypothesis. These results provide a cell biological mechanism explaining regulated nonparallel secretion of digestive enzymes

Analysis of the outer membrane proteome and secretome of Bacteroides fragilis reveals a multiplicity of secretion mechanisms.

Directory of Open Access Journals (Sweden)

Marlena M Wilson

Full Text Available Bacteroides fragilis is a widely distributed member of the human gut microbiome and an opportunistic pathogen. Cell surface molecules produced by this organism likely play important roles in colonization, communication with other microbes, and pathogenicity, but the protein composition of the outer membrane (OM and the mechanisms used to transport polypeptides into the extracellular space are poorly characterized. Here we used LC-MS/MS to analyze the OM proteome and secretome of B. fragilis NCTC 9343 grown under laboratory conditions. Of the 229 OM proteins that we identified, 108 are predicted to be lipoproteins, and 61 are predicted to be TonB-dependent transporters. Based on their proximity to genes encoding TonB-dependent transporters, many of the lipoprotein genes likely encode proteins involved in nutrient or small molecule uptake. Interestingly, protease accessibility and biotinylation experiments indicated that an unusually large fraction of the lipoproteins are cell-surface exposed. We also identified three proteins that are members of a novel family of autotransporters, multiple potential type I protein secretion systems, and proteins that appear to be components of a type VI secretion apparatus. The secretome consisted of lipoproteins and other proteins that might be substrates of the putative type I or type VI secretion systems. Our proteomic studies show that B. fragilis differs considerably from well-studied Gram-negative bacteria such as Escherichia coli in both the spectrum of OM proteins that it produces and the range of secretion strategies that it utilizes.

Secrets of over-indebted people

Directory of Open Access Journals (Sweden)

Valérie BILLAUDEAU

2013-12-01

Full Text Available Today, the economic and financial crisis is brought to light and it is now clear that many people are directly impacted by this phenomenon. However, a lot of situations are obviously hidden and in particular those concerning over-indebted people. These people often find that it is difficult to express the hardship they are going through and keep silent because is more comfortable for them. The media also does not tackle this burning issue because the complexity of some situations complicates the message. Therefore, a giant gap has appeared leaving over-indebted people entrapped in their secret. Starting from this hypothesis, this article will examine the results of a research conducted on the over-indebted people (survey on written press, analysis of TV broadcasts, analysis of records related to person in debts and responses of people in debts and the secrets that this phenomenon involves.

Application of native signal sequences for recombinant proteins secretion in Pichia pastoris

DEFF Research Database (Denmark)

Borodina, Irina; Do, Duy Duc; Eriksen, Jens C.

Background Methylotrophic yeast Pichia pastoris is widely used for recombinant protein production, largely due to its ability to secrete correctly folded heterologous proteins to the fermentation medium. Secretion is usually achieved by cloning the recombinant gene after a leader sequence, where...... alpha‐mating factor (MF) prepropeptide from Saccharomyces cerevisiae is most commonly used. Our aim was to test whether signal peptides from P. pastoris native secreted proteins could be used to direct secretion of recombinant proteins. Results Eleven native signal peptides from P. pastoris were tested...... by optimization of expression of three different proteins in P. pastoris. Conclusions Native signal peptides from P. pastoris can be used to direct secretion of recombinant proteins. A novel USER‐based P. pastoris system allows easy cloning of protein‐coding gene with the promoter and leader sequence of choice....

Mucin secretion induced by titanium dioxide nanoparticles.

Directory of Open Access Journals (Sweden)

Eric Y T Chen

2011-01-01

Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

Reduced ghrelin secretion in the hypothalamus of rats due to cisplatin-induced anorexia.

Science.gov (United States)

Yakabi, Koji; Sadakane, Chiharu; Noguchi, Masamichi; Ohno, Shino; Ro, Shoki; Chinen, Katsuya; Aoyama, Toru; Sakurada, Tomoya; Takabayashi, Hideaki; Hattori, Tomohisa

2010-08-01

Although chemotherapy with cisplatin is a widely used and effective cancer treatment, the undesirable gastrointestinal side effects associated with it, such as nausea, vomiting, and anorexia, markedly decrease patients' quality of life. To elucidate the mechanism underlying chemotherapy-induced anorexia, focusing on the hypothalamic ghrelin secretion-anorexia association, we measured hypothalamic ghrelin secretion in fasted and cisplatin-treated rats. Hypothalamic ghrelin secretion changes after vagotomy or administration of cisplatin. Cisplatin + rikkunshito, a serotonin 2C receptor antagonist or serotonin 3 receptor antagonist, was investigated. The effects of intracerebroventricular (icv) administration of ghrelin or the serotonin 2C receptor antagonist SB242084 on food intake were also evaluated in cisplatin-treated rats. Hypothalamic ghrelin secretion significantly increased in 24-h-fasted rats compared to freely fed rats and was markedly reduced 24 and 48 h after cisplatin treatment in cisplatin-treated rats compared to saline-treated rats, although their plasma ghrelin levels were comparable. In cisplatin-treated rats, icv ghrelin administration reversed the decrease in food intake, vagotomy partially restored hypothalamic ghrelin secretion, and hypothalamic serotonin 2C receptor mRNA expression increased significantly. Administration of rikkunshito (an endogenous ghrelin enhancer) or a serotonin 2C receptor antagonist reversed the decrease in hypothalamic ghrelin secretion and food intake 24 h after cisplatin treatment. Cisplatin-induced anorexia is mediated through reduced hypothalamic ghrelin secretion. Cerebral serotonin 2C receptor activation partially induces decrease in hypothalamic ghrelin secretion, and rikkunshito suppresses cisplatin-induced anorexia by enhancing this secretion.

Onset of apoprotein E secretion during differentiation of mouse bone marrow-derived mononuclear phagocytes

International Nuclear Information System (INIS)

Werb, Z.; Chin, J.R.

1983-01-01

A number of macrophage functions were sequentially expressed when the bone marrow precursors of mononuclear phagocytes differentiated in culture in the presence of a specific growth factor, colony-stimulating factor-1. The authors defined the expression of apoprotein E (ApoE), a major secreted protein of resident peritoneal macrophages, during maturation of adherent bone marrow-derived mononuclear phagocytes into macrophages. By 5 d the bone marrow macrophages were active secretory cells, but few cells contained intracellular immunoreactive ApoE, and little, if any, ApoE was secreted. ApoE secretion was initiated at 9 d, and this correlated with an increase in the percentage of macrophages containing intracellular ApoE. The onset of ApoE secretion was selective, and little change occurred in the other major secreted proteins detected by [ 35 S]methionine incorporation. In parallel, the high rate of plasminogen activator secretion, which peaked at 7 d, decreased markedly. ApoE secretion was not associated with altered expression of the macrophage surface antigen, la, or with secretion of fibronectin. Virtually all cells in independent colonies of bone marrow-derived macrophages eventually expressed ApoE. The proliferating monocyte/macrophage-like cell lines P388D1, J774.2, WHEI-3, RAW 264.1, and MGI.D + secreted little or no ApoE. These data establish that ApoE secretion is developmentally regulated

Neural regulation of glucagon-like peptide-1 secretion in pigs

DEFF Research Database (Denmark)

Hansen, Lene; Lampert, Sarah; Mineo, Hitoshi

2004-01-01

Glucagon-like peptide (GLP)-1 is secreted rapidly from the intestine postprandially. We therefore investigated its possible neural regulation. With the use of isolated perfused porcine ileum, GLP-1 secretion was measured in response to electrical stimulation of the mixed, perivascular nerve supply...

Multiplexed Quantitation of Intraphagocyte Mycobacterium tuberculosis Secreted Protein Effectors

Directory of Open Access Journals (Sweden)

Fadel Sayes

2018-04-01

Full Text Available Summary: The pathogenic potential of Mycobacterium tuberculosis largely depends on ESX secretion systems exporting members of the multigenic Esx, Esp, and PE/PPE protein families. To study the secretion and regulation patterns of these proteins while circumventing immune cross-reactions due to their extensive sequence homologies, we developed an approach that relies on the recognition of their MHC class II epitopes by highly discriminative T cell receptors (TCRs of a panel of T cell hybridomas. The latter were engineered so that each expresses a unique fluorescent reporter linked to specific antigen recognition. The resulting polychromatic and multiplexed imaging assay enabled us to measure the secretion of mycobacterial effectors inside infected host cells. We applied this novel technology to a large panel of mutants, clinical isolates, and host-cell types to explore the host-mycobacteria interplay and its impact on the intracellular bacterial secretome, which also revealed the unexpected capacity of phagocytes from lung granuloma to present mycobacterial antigens via MHC class II. : Sayes et al. develop an approach to express distinct fluorescent reporters that is based on the recognition of specific Mycobacterium tuberculosis MHC class II epitopes by highly discriminative T cell hybridomas. This multiplexed technology allows the study of secretion, subcellular location, and regulation patterns of these instrumental protein members. Keywords: mycobacterium tuberculosis, type VII secretion systems, intracellular bacteria, T-cell hybridomas, mycobacterial virulence factors, bacterial antigen presentation, lentiviral vectors, reporter T cells, in vivo antigen presentation, protein localization

Role of pancreatic polypeptide in the regulation of pancreatic exocrine secretion in dogs

International Nuclear Information System (INIS)

Shiratori, Keiko; Lee, K.Y.; Chang, Tamin; Jo, Y.H.; Coy, D.H.; Chey, W.Y.

1988-01-01

The effect of intravenous infusion of synthetic human pancreatic polypeptide (HPP) or a rabbit anti-PP serum on pancreatic exocrine secretion was studied in 10 dogs with gastric and Thomas duodenal cannulas. The infusion of HPP, achieved a plasma PP concentration that mimicked the peak plasma concentration of PP in both interdigestive and postprandial states. This dose of HPP significantly inhibited pancreatic secretion in the interdigestive state. By contrast, immunoneutralization of circulating PP by a rabbit anti-PP serum resulted in significant increases in both interdigestive and postprandial pancreatic secretion, including water, bicarbonate, and protein. The increase in the pancreatic secretion paralleled a decrease in circulating PP level, which lasted for as long as 5 days. Furthermore, the anti-PP serum blocked the inhibitory action of exogenous HPP on pancreatic exocrine secretion. The present study indicates that endogenous PP plays a significant role in the regulation of the pancreatic exocrine secretion in both interdigestive and digestive states. Thus the authors conclude that PP is another hormone regulating pancreatic exocrine secretion in dogs

Contraction induced secretion of VEGF from skeletal muscle cells is mediated by adenosine

DEFF Research Database (Denmark)

Høier, Birgitte; Olsen, Karina; Nyberg, Michael Permin

2010-01-01

and that the contraction induced secretion of VEGF is partially mediated via adenosine acting on A(2B) adenosine receptors. Moreover, the contraction induced secretion of VEGF protein from muscle is dependent on both PKA and MAPK activation, but only the MAPK pathway appears to be adenosine dependent.......The role of adenosine and contraction for secretion of VEGF in skeletal muscle was investigated in human subjects and rat primary skeletal muscle cells. Microdialysis probes were inserted into the thigh muscle of seven male subjects and dialysate was collected at rest, during infusion of adenosine...... and contraction caused secretion of VEGF (pcontraction induced secretion of VEGF protein was abolished by the A(2B) antagonist enprofyllin and markedly reduced by inhibition of PKA or MAPK. The results demonstrate that adenosine causes secretion of VEGF from human skeletal muscle cells...

Effect of metabolic control on parathyroid hormone secretion in diabetic patients

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Paula F.J.A.

2001-01-01

Full Text Available The metabolic derangement caused by diabetes mellitus may potentially affect bone mineral metabolism. In the present study we evaluated the effect of diabetes metabolic control on parathyroid hormone (PTH secretion during stimulation with EDTA infusion. The study was conducted on 24 individuals, 8 of them normal subjects (group N: glycated hemoglobin - HbA1C = 4.2 ± 0.2%; range = 3.5-5.0%, 8 patients with good and regular metabolic control (group G-R: HbA1C = 7.3 ± 0.4%; range = 6.0-8.5%, and 8 patients with poor metabolic control (group P: HbA1C = 12.5 ± 1.0%; range: 10.0-18.8%. Blood samples were collected at 10-min intervals throughout the study (a basal period of 30 min and a 2-h period of EDTA infusion, 30 mg/kg body weight and used for the determination of ionized calcium, magnesium, glucose and intact PTH. Basal ionized calcium levels were slightly lower in group P (1.19 ± 0.01 mmol/l than in group N (1.21 ± 0.01 mmol/l and group G-R (1.22 ± 0.01 mmol/l. After EDTA infusion, the three groups presented a significant fall in calcium, but with no significant difference among them at any time. Basal magnesium levels and levels determined during EDTA infusion were significantly lower (P<0.01 in group P than in group N. The induction of hypocalcemia caused an elevation in PTH which was similar in groups N and G-R but significantly higher than in group P throughout the infusion period (+110 min, N = 11.9 ± 2.1 vs G-R = 13.7 ± 1.6 vs P = 7.5 ± 0.7 pmol/l; P<0.05 for P vs N and G-R. The present results show that PTH secretion is impaired in patients with poorly controlled diabetes.

Unraveling the Wnt secretion pathway

NARCIS (Netherlands)

Harterink, M.

2011-01-01

The Wnt family of signaling proteins has essential functions in development and adult tissue homeostasis throughout the animal kingdom. Although signaling cascades triggered by Wnt proteins have been extensively studied, much remains to be learned about how Wnts are produced and secreted and how

The importance of microbiological tests of vaginal secretion during reproductive period

Directory of Open Access Journals (Sweden)

Arsić-Arsenijević Valentina S.

2004-01-01

Full Text Available Vaginal infections, during reproductive period are frequent and although not life treating, they can affect their normal functions. They can also affect wommen's fertility as well as the course of pregnancy. The outcome of pregnancy can be endangered due to the possibility of infection of newborn while passing trough birth canal of the infected mother. As statistically shown, bacterial vaginosis is considerably more often found with the patients having precancerous changes on cervix, or diagnosed cancer of cervix, comparing with women with healthy cervix. It can also cause the apperance of postoperative pelvic cellulitis after hysterectomy. On the other side, the presence of S. agalactiae in vaginal secretion may cause very serious and lethal infections of the newborn such as meningitis, pneumonia and sepsis. As for protozoa T. vaginalis it has been shown that it could cause reduced fertility ability and that during pregnancy it could demage fetal membranes and bring to its premature rupture and premature birth. There is also increased risk of cervix cancer. During reproductive period of women especially if risk factors are existing such as hormone therapy, diabetes mellitus type 1 and applications of wide range antibiotics, vaginal fungal infections caused by Candida can frequently appear. These infection apart from the discomfort like itch and affluent secretion they can also mean diagnostic and therapeutical problem. Regular microbiological test of women are highly recommended during reproductive period as standard for bacterial vaginosis, fungal and trichomonas infections. If those results appear negative, further microbiological tests are necessary. Such tests which are more elaborate, more timely and more expensive are referring to tests on chlamidia, micoplasma and some viruses that can also be the cause of vaginal secretion disbalance in women during reproductive period.

[Importance of microbiologic examination of vaginal secretions in the reproductive period].

Science.gov (United States)

Arsić-Arsenijević, Valentina; Radonjić, Ivana; Mijac, Vera; Cirković, Ivana

2004-01-01

Vaginal infections, during reproductive period are frequent and although not life treating, they can affect their normal functions. They can also affect women's fertility as well as the course of pregnancy. The outcome of pregnancy can be endangered due to the possibility of infection of newborn while passing trough birth canal of the infected mother. As statistically shown, bacterial vaginosis is considerably more often found with the patients having precancerous changes on cervix, or diagnosed cancer of cervix, comparing with women with healthy cervix. It can also cause the appearance of postoperative pelvic cellulitis after hysterectomy. On the other side, the presence of S. agalactiae in vaginal secretion may cause very serious and lethal infections of the newborn such as meningitis, pneumonia and sepsis. As for protozoa T. vaginalis it has been shown that it could cause reduced fertility ability and that during pregnancy it could damage fetal membranes and bring to its premature rupture and premature birth. There is also increased risk of cervix cancer. During reproductive period of women especially if risk factors are existing such as hormone therapy, diabetes mellitus type 1 and applications of wide range antibiotics, vaginal fungal infections caused by Candida can frequently appear. These infection apart from the discomfort like itch and affluent secretion they can also mean diagnostic and therapeutical problem. Regular microbiological test of women are highly recommended during reproductive period as standard for bacterial vaginosis, fungal and trichomonas infections. If those results appear negative, further microbiological tests are necessary. Such tests which are more elaborate, more timely and more expensive are referring to tests on chlamydia, microplasma and some viruses that can also be the cause of vaginal secretion disbalance in women during reproductive period.

Cigarette company trade secrets are not secret: an analysis of reverse engineering reports in internal tobacco industry documents released as a result of litigation.

Science.gov (United States)

Velicer, Clayton; Lempert, Lauren K; Glantz, Stanton

2015-09-01

Use previously secret tobacco industry documents to assess tobacco companies' routine claims of trade secret protection for information on cigarette ingredients, additives and construction made to regulatory agencies, as well as the companies' refusal to publicly disclose this information. We analysed previously secret tobacco industry documents available at (http://legacy.library.ucsf.edu) to identify 100 examples of seven major tobacco companies' reverse engineering of their competitors' brands between 1937 and 2001. These reverse engineering reports contain detailed data for 142 different measurements for at least two companies, including physical parameters of the cigarettes, tobacco types, humectants, additives, flavourings, and smoke constituents of competitors' cigarettes. These 100 documents were distributed to 564 employees, including top managers in domestic and foreign offices across multiple departments, including executive leadership, research and design, product development, marketing and legal. These documents reported new competitors' products, measured ingredient changes over time, and informed companies' decisions regarding ingredients in their own products. Because cigarette companies routinely analyse their competitors' cigarettes in great detail, this information is neither secret nor commercially valuable and, thus, does not meet the legal definition of a 'trade secret.' This information is only being kept 'secret' from the people consuming cigarettes and the scientific community. Public agencies should release this detailed information because it would provide valuable information about how ingredients affect addictiveness and toxicity, and would help the public health community and consumers better understand the impact of cigarette design on human health. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A Finite Equivalence of Verifiable Multi-secret Sharing

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Hui Zhao

2012-02-01

Full Text Available We give an abstraction of verifiable multi-secret sharing schemes that is accessible to a fully mechanized analysis. This abstraction is formalized within the applied pi-calculus by using an equational theory which characterizes the cryptographic semantics of secret share. We also present an encoding from the equational theory into a convergent rewriting system, which is suitable for the automated protocol verifier ProVerif. Based on that, we verify the threshold certificate protocol in ProVerif.

Proinflammatory Cytokine Infusion Attenuates LH's Feedforward on Testosterone Secretion: Modulation by Age

Science.gov (United States)

Yang, Rebecca; Roelfsema, Ferdinand; Takahashi, Paul

2016-01-01

Context: In the experimental animal, inflammatory signals quench LH's feedforward drive of testosterone (T) secretion and appear to impair GnRH-LH output. The degree to which such suppressive effects operate in the human is not known. Objective: To test the hypothesis that IL-2 impairs LH's feedforward drive on T and T's feedback inhibition of LH secretion in healthy men. Setting: Mayo Center for Translational Science Activities. Patients or Other Participants: A total of 35 healthy men, 17 young and 18 older. Interventions: Randomized prospective double-blind saline-controlled study of IL-2 infusion in 2 doses with concurrent 10-minute blood sampling for 24 hours. Main Outcome Measures: Deconvolution analysis of LH and T secretion. Results: After saline injection, older compared with young men exhibited reduced LH feedforward drive on T secretion (P feedback inhibition of LH secretion (P feedforward onto T secretion declined markedly especially in young subjects (P feedback on LH secretion especially in older volunteers. Conclusion: This investigation confirms combined feedforward and feedback deficits in older relative to young men given saline and demonstrates 1) joint mechanisms by which IL-2 enforces biochemical hypogonadism, viz, combined feedforward block and feedback amplification; and 2) unequal absolute inhibition of T and LH secretion by IL-2 in young and older men. These outcomes establish that the male gonadal axis is susceptible to dual-site suppression by a prototypic inflammatory mediator. Thus, we postulate that selected ILs might also enforce male hypogonadism in chronic systemic inflammation. PMID:26600270

The RhoGAP Stard13 controls insulin secretion through F-actin remodeling

Directory of Open Access Journals (Sweden)

Heike Naumann

2018-02-01

Full Text Available Objective: Actin cytoskeleton remodeling is necessary for glucose-stimulated insulin secretion in pancreatic β-cells. A mechanistic understanding of actin dynamics in the islet is paramount to a better comprehension of β-cell dysfunction in diabetes. Here, we investigate the Rho GTPase regulator Stard13 and its role in F-actin cytoskeleton organization and islet function in adult mice. Methods: We used Lifeact-EGFP transgenic animals to visualize actin cytoskeleton organization and dynamics in vivo in the mouse islets. Furthermore, we applied this model to study actin cytoskeleton and insulin secretion in mutant mice deleted for Stard13 selectively in pancreatic cells. We isolated transgenic islets for 3D-imaging and perifusion studies to measure insulin secretion dynamics. In parallel, we performed histological and morphometric analyses of the pancreas and used in vivo approaches to study glucose metabolism in the mouse. Results: In this study, we provide the first genetic evidence that Stard13 regulates insulin secretion in response to glucose. Postnatally, Stard13 expression became restricted to the mouse pancreatic islets. We showed that Stard13 deletion results in a marked increase in actin polymerization in islet cells, which is accompanied by severe reduction of insulin secretion in perifusion experiments. Consistently, Stard13-deleted mice displayed impaired glucose tolerance and reduced glucose-stimulated insulin secretion. Conclusions: Taken together, our results suggest a previously unappreciated role for the RhoGAP protein Stard13 in the interplay between actin cytoskeletal remodeling and insulin secretion. Keywords: F-actin, Insulin secretion, Islet, Pancreas, Lifeact, Stard13

Interaction of corneal nociceptive stimulation and lacrimal secretion.

Science.gov (United States)

Situ, Ping; Simpson, Trefford L

2010-11-01

To investigate the interaction between corneal stimuli at different positions and tear secretion and to establish relationships between nociceptive stimuli detection thresholds and stimulated tearing. Using a computerized Belmonte-esthesiometer, mechanical and chemical stimuli, from 0% to 200% of the threshold in 50% steps, were delivered (in random order) to the central and peripheral (approximately 2-mm inside the limbus) cornea during four separate sessions to 15 subjects. Immediately after each stimulus, tear meniscus height (TMH) was measured using optical coherence tomography to quantify the amount of lacrimal secretion, and subjects reported whether they felt tears starting to accumulate in their eyes. Thresholds (50% detection) for detection of tearing were estimated. TMH increased with increasing stimulus intensity (P lacrimation reflex. Central mechanical corneal stimulation is the most effective stimulus-position pairing and appears to be the major sensory driving force for reflex tear secretion by the lacrimal functional unit.

Adult Hematology and Clinical Chemistry Laboratory Reference Ranges in a Zimbabwean Population.

Science.gov (United States)

Samaneka, Wadzanai P; Mandozana, Gibson; Tinago, Willard; Nhando, Nehemiah; Mgodi, Nyaradzo M; Bwakura-Dangarembizi, Mutsawashe F; Munjoma, Marshall W; Gomo, Zvenyika A R; Chirenje, Zvavahera M; Hakim, James G

2016-01-01

Laboratory reference ranges used for clinical care and clinical trials in various laboratories in Zimbabwe were derived from textbooks and research studies conducted more than ten years ago. Periodic verification of these ranges is essential to track changes over time. The purpose of this study was to establish hematology and chemistry laboratory reference ranges using more rigorous methods. A community-based cross-sectional study was carried out in Harare, Chitungwiza, and Mutoko. A multistage sampling technique was used. Samples were transported from the field for analysis at the ISO15189 certified University of Zimbabwe-University of California San Francisco Central Research Laboratory. Hematology and clinical chemistry reference ranges lower and upper reference limits were estimated at the 2.5th and 97.5th percentiles respectively. A total of 769 adults (54% males) aged 18 to 55 years were included in the analysis. Median age was 28 [IQR: 23-35] years. Males had significantly higher red cell counts, hemoglobin, hematocrit, and mean corpuscular hemoglobin compared to females. Females had higher white cell counts, platelets, absolute neutrophil counts, and absolute lymphocyte counts compared to males. There were no gender differences in eosinophils, monocytes, and absolute basophil count. Males had significantly higher levels of urea, sodium, potassium, calcium, creatinine, amylase, total protein, albumin and liver enzymes levels compared to females. Females had higher cholesterol and lipase compared with males. There are notable differences in the white cell counts, neutrophils, cholesterol, and creatinine kinase when compared with the currently used reference ranges. Data from this study provides new country specific reference ranges which should be immediately adopted for routine clinical care and accurate monitoring of adverse events in research studies.

Bidrag til "Life begins at 100 - Secrets of the supercentenarians"

DEFF Research Database (Denmark)

von Bornemann Hjelmborg, Jacob

2009-01-01

Bidrag til: "Life begins at 100 - Secrets of the supercentenarians". Uddrag fra Human Genetics, vol. 119 p 1432. Udgivelsesdato: 5 september......Bidrag til: "Life begins at 100 - Secrets of the supercentenarians". Uddrag fra Human Genetics, vol. 119 p 1432. Udgivelsesdato: 5 september...

Salivary Secretion and Composition in Malaria: A Case-control Study

African Journals Online (AJOL)

Summary: No previous studies have documented changes in salivary secretion in patients with malaria. This study aimed to compare salivary secretion and composition in malaria positive and malaria negative individuals. Ninety participants composed of 40 malaria parasite positive and 50 malaria parasite negative ...

The relationship between bone turnover and insulin sensitivity and secretion

DEFF Research Database (Denmark)

Frost, Morten; Balkau, Beverley; Hatunic, Mensud

2018-01-01

Bone metabolism appears to influence insulin secretion and sensitivity, and insulin promotes bone formation in animals, but similar evidence in humans is limited. The objectives of this study are to explore if bone turnover markers were associated with insulin secretion and sensitivity and to det...

The secreted L-arabinose isomerase displays anti-hyperglycemic effects in mice.

Science.gov (United States)

Rhimi, Moez; Bermudez-Humaran, Luis G; Huang, Yuan; Boudebbouze, Samira; Gaci, Nadia; Garnier, Alexandrine; Gratadoux, Jean-Jacques; Mkaouar, Héla; Langella, Philippe; Maguin, Emmanuelle

2015-12-21

The L-arabinose isomerase is an intracellular enzyme which converts L-arabinose into L-ribulose in living systems and D-galactose into D-tagatose in industrial processes and at industrial scales. D-tagatose is a natural ketohexose with potential uses in pharmaceutical and food industries. The D-galactose isomerization reaction is thermodynamically equilibrated, and leads to secondary subproducts at high pH. Therefore, an attractive L-arabinose isomerase should be thermoactive and acidotolerant with high catalytic efficiency. While many reports focused on the set out of a low cost process for the industrial production of D-tagatose, these procedures remain costly. When compared to intracellular enzymes, the production of extracellular ones constitutes an interesting strategy to increase the suitability of the biocatalysts. The L-arabinose isomerase (L-AI) from Lactobacillus sakei was expressed in Lactococcus lactis in fusion with the signal peptide of usp45 (SP(Usp45)). The L-AI protein and activity were detected only in the supernatant of the induced cultures of the recombinant L. lactis demonstrating the secretion in the medium of the intracellular L. sakei L-AI in an active form. Moreover, we showed an improvement in the enzyme secretion using either (1) L. lactis strains deficient for their two major proteases, ClpP and HtrA, or (2) an enhancer of protein secretion in L. lactis fused to the recombinant L-AI with the SP(Usp45). Th L-AI enzyme secreted by the recombinant L. lactis strains or produced intracellularly in E. coli, showed the same functional properties than the native enzyme. Furthermore, when mice are fed with the L. lactis strain secreting the L-AI and galactose, tagatose was produced in vivo and reduced the glycemia index. We report for the first time the secretion of the intracellular L-arabinose isomerase in the supernatant of food grade L. lactis cultures with hardly display other secreted proteins. The secreted L-AI originated from the food

The anionic basis of fluid secretion by the rabbit mandibular salivary gland

DEFF Research Database (Denmark)

Case, R M; Hunter, M; Novak, I

1984-01-01

The role played by anions in salivary secretion has been studied in experiments on the isolated, perfused mandibular gland of the rabbit, in which perfusate Cl- and/or HCO3- were replaced by other anions. Replacement of Cl- with Br- had no significant effect on salivary secretion rate, but replac......The role played by anions in salivary secretion has been studied in experiments on the isolated, perfused mandibular gland of the rabbit, in which perfusate Cl- and/or HCO3- were replaced by other anions. Replacement of Cl- with Br- had no significant effect on salivary secretion rate...

Regulation of gut hormone secretion. Studies using isolated perfused intestines

DEFF Research Database (Denmark)

Svendsen, Berit; Holst, Jens Juul.

2016-01-01

hormones is highly increased after gastric bypass operations, which have turned out to be an effective therapy of not only obesity but also type 2 diabetes. These effects are likely to be due, at least in part, to increases in the secretion of these gut hormones (except GIP). Therefore, stimulation...... of the endogenous hormone represents an appealing therapeutic strategy, which has spurred an interest in understanding the regulation of gut hormone secretion and a search for particularly GLP-1 and PYY secretagogues. The secretion of the gut hormones is stimulated by oral intake of nutrients often including...

Type VI Secretion System Toxins Horizontally Shared between Marine Bacteria.

Directory of Open Access Journals (Sweden)

Dor Salomon

2015-08-01

Full Text Available The type VI secretion system (T6SS is a widespread protein secretion apparatus used by Gram-negative bacteria to deliver toxic effector proteins into adjacent bacterial or host cells. Here, we uncovered a role in interbacterial competition for the two T6SSs encoded by the marine pathogen Vibrio alginolyticus. Using comparative proteomics and genetics, we identified their effector repertoires. In addition to the previously described effector V12G01_02265, we identified three new effectors secreted by T6SS1, indicating that the T6SS1 secretes at least four antibacterial effectors, of which three are members of the MIX-effector class. We also showed that the T6SS2 secretes at least three antibacterial effectors. Our findings revealed that many MIX-effectors belonging to clan V are "orphan" effectors that neighbor mobile elements and are shared between marine bacteria via horizontal gene transfer. We demonstrated that a MIX V-effector from V. alginolyticus is a functional T6SS effector when ectopically expressed in another Vibrio species. We propose that mobile MIX V-effectors serve as an environmental reservoir of T6SS effectors that are shared and used to diversify antibacterial toxin repertoires in marine bacteria, resulting in enhanced competitive fitness.

Identification and characterization of secreted proteins in Eimeria tenella

Science.gov (United States)

Ramlee, Intan Azlinda; Firdaus-Raih, Mohd; Wan, Kiew-Lian

2015-09-01

Eimeria tenella is a protozoan parasite that causes coccidiosis, an economically important disease in the poultry industry. The characterization of proteins that are secreted by parasites have been shown to play important roles in parasite invasion and are considered to be potential control agents. In this study, 775 proteins potentially secreted by E. tenella were identified. These proteins were further filtered to remove mitochondrial proteins. Out of 763 putative secreted proteins, 259 proteins possess transmembrane domains while another 150 proteins have GPI (Glycosylphosphatidylinositol) anchors. Homology search revealed that 315 and 448 proteins have matches with known and hypothetical proteins in the database, respectively. Within this data set, previously characterized secretory proteins such as micronemes, rhoptry kinases and dense granules were detected.

77 FR 34037 - Agency Information Collection Activities; Proposed Collection; Comment Request; Trade Secret...

Science.gov (United States)

2012-06-08

... Activities; Proposed Collection; Comment Request; Trade Secret Claims for Emergency Planning and Community... Planning and Community Right-to- Know Act (EPCRA). Title: Trade Secret Claims for Emergency Planning and...). Estimated total number of potential respondents: 481. Frequency of response: Trade secret claims are...

Amylase and chymotrypsinogen synthesis and secretion by the anesthetized rat pancreas

International Nuclear Information System (INIS)

Iovanna, J.; Giorgi, D.; Dagorn, J.C.

1987-01-01

To investigate the origin of nonparallel secretion, pancreatic juice was collected in the anesthetized rat, during infusion of [ 3 H]phenylalanine. In the basal state, the amylase to chymotrypsinogen ratios of activities and of [ 3 H] incorporations were 3.5 and 2.5 times higher than in the homogenate, respectively. Both ratios decreased to the value in the homogenate upon caerulein stimulation (600 ng/kg). Inhibition of protein synthesis by cycloheximide (15 ng/kg) did not alter enzyme secretion ratios, and depressed basal protein output only partly, suggesting similar secretory pathways for basal and stimulated secretion. Finally, when [ 3 H]phenylalanine was given before anesthesia, the amylase to chymotrypsinogen ratio of incorporations was again higher in basal secretion than in homogenate, even when further protein synthesis was blocked by cycloheximide before urethane injection. Hence, basal secretion comes from a pancreatic compartment which is functional, although minor, in the conscious animal, and shows a higher rate of amylase synthesis, compared to chymotrypsinogen, than the rest of the gland. It could consist of a subpopulation of acinar cells

Adrenergic effects on secretion of amylase from the rat salivary glands

DEFF Research Database (Denmark)

Poulsen, Steen Seier; Nexø, Ebba

1988-01-01

The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly. The res......The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly....... The result of infusion of alpha- and beta-adrenergic antagonists as well as noradrenaline and isoproterenol showed that secretion of salivary amylase is predominantly mediated by stimulation of beta-adrenergic receptors, especially of the beta 1-subtype. Investigation of the isoenzyme pattern in saliva......, pancreatic juice and serum demonstrated that the major component in serum is salivary amylase. This study has shown that beta-adrenergic agents stimulate secretion of amylase from the salivary glands in rats. Though the secretion is mainly exocrine small amounts of amylase is found in serum, which seems...

A protein secretion system linked to bacteroidete gliding motility and pathogenesis

Science.gov (United States)

Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J.; Rhodes, Ryan G.; Nakayama, Koji

2009-01-01

Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum. PMID:19966289

Melatonin and Angelman Syndrome: Implications and Mathematical Model of Diurnal Secretion

Directory of Open Access Journals (Sweden)

Justyna Paprocka

2017-01-01

Full Text Available The main aim of the study was to compare the melatonin rhythms in subjects with Angelman syndrome (n=9 and in children with (n=80 and without (n=40 epilepsy (nonepileptic patients diagnosed with peripheral nerve palsies, myopathy, and back pain using our mathematical model of melatonin circadian secretion. The characteristics describing the diurnal hormone secretion such as minimum melatonin concentration, release amplitude, phase shift of melatonin release, and sleep duration as well as the dim light melatonin onset (DLMO of melatonin secretion and the γ shape parameter allow analyzing the fit and deducing about how much the measured melatonin profile differs from a physiological bell-shaped secretion. The estimated sleep duration and phase shift of melatonin release as well as the DMLO offsets at 25% and 50% relative thresholds are the key characteristic of Angelman syndrome children. As revealed from the γ shape parameter, the melatonin secretion profiles are disturbed in majority of the AG subjects revealing rather a triangular course instead of the bell-like one.

Efficient secretion of small proteins in mammalian cells relies on Sec62-dependent posttranslational translocation

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Lakkaraju, Asvin K. K.; Thankappan, Ratheeshkumar; Mary, Camille; Garrison, Jennifer L.; Taunton, Jack; Strub, Katharina

2012-01-01

Mammalian cells secrete a large number of small proteins, but their mode of translocation into the endoplasmic reticulum is not fully understood. Cotranslational translocation was expected to be inefficient due to the small time window for signal sequence recognition by the signal recognition particle (SRP). Impairing the SRP pathway and reducing cellular levels of the translocon component Sec62 by RNA interference, we found an alternate, Sec62-dependent translocation path in mammalian cells required for the efficient translocation of small proteins with N-terminal signal sequences. The Sec62-dependent translocation occurs posttranslationally via the Sec61 translocon and requires ATP. We classified preproteins into three groups: 1) those that comprise ≤100 amino acids are strongly dependent on Sec62 for efficient translocation; 2) those in the size range of 120–160 amino acids use the SRP pathway, albeit inefficiently, and therefore rely on Sec62 for efficient translocation; and 3) those larger than 160 amino acids depend on the SRP pathway to preserve a transient translocation competence independent of Sec62. Thus, unlike in yeast, the Sec62-dependent translocation pathway in mammalian cells serves mainly as a fail-safe mechanism to ensure efficient secretion of small proteins and provides cells with an opportunity to regulate secretion of small proteins independent of the SRP pathway. PMID:22648169

The role of somatostatin in GLP-1-induced inhibition of glucagon secretion in mice

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Ørgaard, Anne; Holst, Jens J

2017-01-01

AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) receptor agonists are currently used for the treatment of type 2 diabetes. Their main mechanism of action is enhancement of glucose-induced insulin secretion (from increased beta cell glucose sensitivity) and inhibition of glucagon secretion...... on glucagon secretion is heavily debated. Glucagon inhibition is also said to be glucose-dependent, although it is unclear what is meant by this. We hypothesise here that GLP-1 does not inhibit glucagon secretion during hypoglycaemia because the inhibition depends on somatostatin secretion, which in turn...

Dermatoxin and phylloxin from the waxy monkey frog, Phyllomedusa sauvagei: cloning of precursor cDNAs and structural characterization from lyophilized skin secretion.

Science.gov (United States)

Chen, Tianbao; Walker, Brian; Zhou, Mei; Shaw, Chris

2005-07-15

Amphibian skin is a morphologically, biochemically and physiologically complex organ that performs the wide range of functions necessary for amphibian survival. Here we describe the primary structures of representatives of two novel classes of amphibian skin antimicrobials, dermatoxin and phylloxin, from the skin secretion of Phyllomedusa sauvagei, deduced from their respective precursor encoding cDNAs cloned from a lyophilized skin secretion library. A degenerate primer, designed to a highly conserved domain in the 5'-untranslated region of analogous peptide precursor cDNAs from Phyllomedusa bicolor, was employed in a 3'-RACE reaction. Peptides with molecular masses coincident with precursor-deduced mature toxin peptides were identified in LC/MS fractions of skin secretion and primary structures were confirmed by MS/MS fragmentation. This integrated experimental approach can thus rapidly expedite the primary structural characterization of amphibian skin peptides in a manner that circumvents specimen sacrifice whilst preserving robustness of scientific data.

Small-Molecule Inhibitors of the Type III Secretion System

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Lingling Gu

2015-09-01

Full Text Available Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS, existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess many highly conserved main structural components comprised of about 20 proteins. Many Gram-negative bacteria carry T3SS as a major virulence determinant, and using the T3SS, the bacteria secrete and inject effector proteins into target host cells, triggering disease symptoms. Therefore, T3SS has emerged as an attractive target for antimicrobial therapeutics. In recent years, many T3SS-targeting small-molecule inhibitors have been discovered; these inhibitors prevent the bacteria from injecting effector proteins and from causing pathophysiology in host cells. Targeting the virulence of Gram-negative pathogens, rather than their survival, is an innovative and promising approach that may greatly reduce selection pressures on pathogens to develop drug-resistant mutations. This article summarizes recent progress in the search for promising small-molecule T3SS inhibitors that target the secretion and translocation of bacterial effector proteins.

Sodium arsenite impairs insulin secretion and transcription in pancreatic β-cells

International Nuclear Information System (INIS)

Diaz-Villasenor, Andrea; Sanchez-Soto, M. Carmen; Cebrian, Mariano E.; Ostrosky-Wegman, Patricia; Hiriart, Marcia

2006-01-01

Human studies have shown that chronic inorganic arsenic (iAs) exposure is associated with a high prevalence and incidence of type 2 diabetes. However, the mechanism(s) underlying this effect are not well understood, and practically, there is no information available on the effects of arsenic on pancreatic β-cells functions. Thus, since insulin secreted by the pancreas plays a crucial role in maintaining glucose homeostasis, our aim was to determine if sodium arsenite impairs insulin secretion and mRNA expression in single adult rat pancreatic β-cells. Cells were treated with 0.5, 1, 2, 5 and 10 μM sodium arsenite and incubated for 72 and 144 h. The highest dose tested (10 μM) decreased β-cell viability, by 33% and 83%, respectively. Insulin secretion and mRNA expression were evaluated in the presence of 1 and 5 μM sodium arsenite. Basal insulin secretion, in 5.6 mM glucose, was not significantly affected by 1 or 5 μM treatment for 72 h, but basal secretion was reduced when cells were exposed to 5 μM sodium arsenite for 144 h. On the other hand, insulin secretion in response to 15.6 mM glucose decreased with sodium arsenite in a dose-dependent manner in such a way that cells were no longer able to distinguish between different glucose concentrations. We also showed a significant decrease in insulin mRNA expression of cells exposed to 5 μM sodium arsenite during 72 h. Our data suggest that arsenic may contribute to the development of diabetes mellitus by impairing pancreatic β-cell functions, particularly insulin synthesis and secretion

Conazole fungicides inhibit Leydig cell testosterone secretion and androgen receptor activation in vitro

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Maarke J.E. Roelofs

2014-01-01

Full Text Available Conazole fungicides are widely used in agriculture despite their suspected endocrine disrupting properties. In this study, the potential (anti-androgenic effects of ten conazoles were assessed and mutually compared with existing data. Effects of cyproconazole (CYPRO, fluconazole (FLUC, flusilazole (FLUS, hexaconazole (HEXA, myconazole (MYC, penconazole (PEN, prochloraz (PRO, tebuconazole (TEBU, triadimefon (TRIA, and triticonazole (TRIT were examined using murine Leydig (MA-10 cells and human T47D-ARE cells stably transfected with an androgen responsive element and a firefly luciferase reporter gene. Six conazoles caused a decrease in basal testosterone (T secretion by MA-10 cells varying from 61% up to 12% compared to vehicle-treated control. T secretion was concentration-dependently inhibited after exposure of MA-10 cells to several concentrations of FLUS (IC50 = 12.4 μM or TEBU (IC50 = 2.4 μM in combination with LH. The expression of steroidogenic and cholesterol biosynthesis genes was not changed by conazole exposure. Also, there were no changes in reactive oxygen species (ROS formation that could explain the altered T secretion after exposure to conazoles. Nine conazoles decreased T-induced AR activation (IC50s ranging from 10.7 to 71.5 μM and effect potencies (REPs were calculated relative to the known AR antagonist flutamide (FLUT. FLUC had no effect on AR activation by T. FLUS was the most potent (REP = 3.61 and MYC the least potent (REP = 0.03 AR antagonist. All other conazoles had a comparable REP from 0.12 to 0.38. Our results show distinct in vitro anti-androgenic effects of several conazole fungicides arising from two mechanisms: inhibition of T secretion and AR antagonism, suggesting potential testicular toxic effects. These effects warrant further mechanistic investigation and clearly show the need for accurate exposure data in order to perform proper (human risk assessment of this class of compounds.

Hybrid threshold adaptable quantum secret sharing scheme with reverse Huffman-Fibonacci-tree coding.

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Lai, Hong; Zhang, Jun; Luo, Ming-Xing; Pan, Lei; Pieprzyk, Josef; Xiao, Fuyuan; Orgun, Mehmet A

2016-08-12

With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost for the real world use. This paper proposes a novel hybrid threshold adaptable quantum secret sharing scheme, using an m-bonacci orbital angular momentum (OAM) pump, Lagrange interpolation polynomials, and reverse Huffman-Fibonacci-tree coding. To be exact, we employ entangled states prepared by m-bonacci sequences to detect eavesdropping. Meanwhile, we encode m-bonacci sequences in Lagrange interpolation polynomials to generate the shares of a secret with reverse Huffman-Fibonacci-tree coding. The advantages of the proposed scheme is that it can detect eavesdropping without joint quantum operations, and permits secret sharing for an arbitrary but no less than threshold-value number of classical participants with much lower bandwidth. Also, in comparison with existing quantum secret sharing schemes, it still works when there are dynamic changes, such as the unavailability of some quantum channel, the arrival of new participants and the departure of participants. Finally, we provide security analysis of the new hybrid quantum secret sharing scheme and discuss its useful features for modern applications.

The highly virulent variola and monkeypox viruses express secreted inhibitors of type I interferon

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Fernández de Marco, María del Mar; Alejo, Alí; Hudson, Paul; Damon, Inger K.; Alcami, Antonio

2010-01-01

Variola virus (VARV) caused smallpox, one of the most devastating human diseases and the first to be eradicated, but its deliberate release represents a dangerous threat. Virulent orthopoxviruses infecting humans, such as monkeypox virus (MPXV), could fill the niche left by smallpox eradication and the cessation of vaccination. However, immunomodulatory activities and virulence determinants of VARV and MPXV remain largely unexplored. We report the molecular characterization of the VARV- and MPXV-secreted type I interferon-binding proteins, which interact with the cell surface after secretion and prevent type I interferon responses. The proteins expressed in the baculovirus system have been purified, and their interferon-binding properties characterized by surface plasmon resonance. The ability of these proteins to inhibit a broad range of interferons was investigated to identify potential adaptation to the human immune system. Furthermore, we demonstrate by Western blot and activity assays the expression of the type I interferon inhibitor during VARV and MPXV infections. These findings are relevant for the design of new vaccines and therapeutics to smallpox and emergent virulent orthopoxviruses because the type I interferon-binding protein is a major virulence factor in animal models, vaccination with this protein induces protective immunity, and its neutralization prevents disease progression.—Fernández de Marco, M. M., Alejo, A., Hudson, P., Damon, I. K., Alcami, A. The highly virulent variola and monkeypox viruses express secreted inhibitors of type I interferon. PMID:20019241

Sugary secretions of wasp galls: a want-to-be extrafloral nectar?

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Aranda-Rickert, Adriana; Rothen, Carolina; Diez, Patricia; González, Ana María; Marazzi, Brigitte

2017-11-10

The most widespread form of protective mutualisms is represented by plants bearing extrafloral nectaries (EFNs) that attract ants and other arthropods for indirect defence. Another, but less common, form of sugary secretion for indirect defence occurs in galls induced by cynipid wasps. Until now, such galls have been reported only for cynipid wasps that infest oak trees in the northern hemisphere. This study provides the first evidence of galls that exude sugary secretions in the southern hemisphere and asks whether they can be considered as analogues of plants' EFNs. The ecology and anatomy of galls and the chemical composition of the secretion were investigated in north-western Argentina, in natural populations of the host trees Prosopis chilensis and P. flexuosa . To examine whether ants protect the galls from natural enemies, ant exclusion experiments were conducted in the field. The galls produce large amounts of sucrose-rich, nectar-like secretions. No typical nectary and sub-nectary parenchymatic tissues or secretory trichomes can be observed; instead there is a dense vascularization with phloem elements reaching the gall periphery. At least six species of ants, but also vespid wasps, Diptera and Coleoptera, consumed the gall secretions. The ant exclusion experiment showed that when ants tended galls, no differences were found in the rate of successful emergence of gall wasps or in the rate of parasitism and inquiline infestation compared with ant-excluded galls. The gall sugary secretion is not analogous to extrafloral nectar because no nectar-producing structure is associated with it, but is functionally equivalent to arthropod honeydew because it provides indirect defence to the plant parasite. As in other facultative mutualisms mediated by sugary secretions, the gall secretion triggers a complex multispecies interaction, in which the outcome of individual pair-wise interactions depends on the ecological context in which they take place. © The Author

Syntaxin-4 is essential for IgE secretion by plasma cells

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Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland); Loughran, Sinéad T.; Walls, Dermot [School of Biotechnology and National Centre for Sensor Research, Dublin City University (Ireland); Loscher, Christine E., E-mail: christine.loscher@dcu.ie [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland)

2013-10-11

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients.

Syntaxin-4 is essential for IgE secretion by plasma cells

International Nuclear Information System (INIS)

Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben; Loughran, Sinéad T.; Walls, Dermot; Loscher, Christine E.

2013-01-01

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients

Assessment of the storz video Macintosh laryngoscope for use in difficult airways: A human simulator study.

Science.gov (United States)

Bair, Aaron E; Olmsted, Kalani; Brown, Calvin A; Barker, Tobias; Pallin, Daniel; Walls, Ron M

2010-10-01

Video laryngoscopy has been shown to improve glottic exposure when compared to direct laryngoscopy in operating room studies. However, its utility in the hands of emergency physicians (EPs) remains undefined. A simulated difficult airway was used to determine if intubation by EPs using a video Macintosh system resulted in an improved glottic view, was easier, was faster, or was more successful than conventional direct laryngoscopy. Emergency medicine (EM) residents and attending physicians at two academic institutions performed endotracheal intubation in one normal and two identical difficult airway scenarios. With the difficult scenarios, the participants used video laryngoscopy during the second case. Intubations were performed on a medium-fidelity human simulator. The difficult scenario was created by limiting cervical spine mobility and inducing trismus. The primary outcome was the proportion of direct versus video intubations with a grade I or II Cormack-Lehane glottic view. Ease of intubation (self-reported via 10-cm visual analog scale [VAS]), time to intubation, and success rate were also recorded. Descriptive statistics as well as medians with interquartile ranges (IQRs) are reported where appropriate. The Wilcoxon matched pairs signed-rank test was used for comparison testing of nonparametric data. Participants (n = 39) were residents (59%) and faculty. All had human intubation experience; 51% reported more than 100 prior intubations. On difficult laryngoscopy, a Cormack-Lehane grade I or II view was obtained in 20 (51%) direct laryngoscopies versus 38 (97%) of the video-assisted laryngoscopies (p < 0.01). The median VAS score for difficult airways was 50 mm (IQR = 28–73 mm) for direct versus 18 mm (IQR = 9–50 mm) for video (p < 0.01). The median time to intubation in difficult airways was 25 seconds (IQR = 16–44 seconds) for direct versus 20 seconds (IQR = 12–35 seconds) for video laryngoscopy (p < 0.01). All intubations were successful without

Secretion of salivary statherin is compromised in uncontrolled diabetic patients

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Masahiro Izumi

2015-06-01

Conclusions and general significance: The results show that synthesis and secretion of statherin is reduced in diabetics and this reduction is salivary gland specific. As compromised salivary statherin secretion leads to increased oral health risk, this study indicates that routine oral health assessment of these patients is warranted.

Skin pathology and medical prognosis in medieval Europe: the secrets of Hippocrates.

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Ackerman Smoller, L

2000-12-01

This article analyzes a medieval text known as The Secrets of Hippocrates. Neither secret (because of its wide circulation in manuscript and print) nor by Hippocrates, the work offered readers a means of offering a prognosis of impending death based on observable signs on the skin. Although the aphorisms that make up the text make little sense in a modern medical understanding, the Secrets of Hippocrates fits well within three medieval traditions: the tradition of secrets literature, the medieval medical tradition, and the tradition of medieval Christian views about the body. First, like other books of secrets, a genre to whose conventions the text closely adheres, the Secrets of Hippocrates offered a shortcut to socially useful knowledge: the ability to offer an accurate medical prognosis. Second, the treatise corresponded to the medieval physician's concern for the so-called nonnaturals, such as diet and exercise. Third, it fit with a medieval Christian notion that sickness and sin were related, as were sin and ugliness. Just as a leper's deformities were a window to his sinful soul, so skin pathologies could clue a medieval physician to the lethal disease hidden inside the body.

Unconventional secretion of tissue transglutaminase involves phospholipid-dependent delivery into recycling endosomes.

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Evgeny A Zemskov

2011-04-01

Full Text Available Although endosomal compartments have been suggested to play a role in unconventional protein secretion, there is scarce experimental evidence for such involvement. Here we report that recycling endosomes are essential for externalization of cytoplasmic secretory protein tissue transglutaminase (tTG. The de novo synthesized cytoplasmic tTG does not follow the classical ER/Golgi-dependent secretion pathway, but is targeted to perinuclear recycling endosomes, and is delivered inside these vesicles prior to externalization. On its route to the cell surface tTG interacts with internalized β1 integrins inside the recycling endosomes and is secreted as a complex with recycled β1 integrins. Inactivation of recycling endosomes, blocking endosome fusion with the plasma membrane, or downregulation of Rab11 GTPase that controls outbound trafficking of perinuclear recycling endosomes, all abrogate tTG secretion. The initial recruitment of cytoplasmic tTG to recycling endosomes and subsequent externalization depend on its binding to phosphoinositides on endosomal membranes. These findings begin to unravel the unconventional mechanism of tTG secretion which utilizes the long loop of endosomal recycling pathway and indicate involvement of endosomal trafficking in non-classical protein secretion.

Fibromyalgia--a syndrome associated with decreased nocturnal melatonin secretion.

Science.gov (United States)

Wikner, J; Hirsch, U; Wetterberg, L; Röjdmark, S

1998-08-01

Most patients with fibromyalgic syndrome (FMS) complain of sleep disturbances, fatigue, and pain. These symptoms might be a consequence of changed melatonin (MT) secretion, since MT is known to have sleep promoting properties. Moreover, serum concentrations of two MT precursors (tryptophan and serotonin)--affecting both sleep and pain perception--appear to be low in patients with FMS. Therefore, the objective of this investigation was to study whether serum MT (s-MT) level is also low in these patients. Eight patients with FMS and 8 healthy sex-, BMI-, and age-matched controls were included in the study. s-MT concentrations were determined every second hour between 1800 and 0800 h. Urine was collected between 2200 and 0700 h for determination of urinary MT excretion. To evaluate total MT secretion between 1800 and 0800 h and MT secretion during the hours of darkness (between 23 and 07 h) individual MT areas under the curve (AUC) were calculated and expressed as group means. The FMS patients had a 31% lower MT secretion than healthy subjects during the hours of darkness (MT AUC 2300-0700 h (mean +/- SEM): 1.70 +/- 0.17 vs 2.48 +/- 0.38 nmol/l; P < 0.05). Also the s-MT peak value was significantly lower in the patient group: 0.28 +/- 0.03 vs 0.44 +/- 0.06 nmol/l; P < 0.05). Patients with fibromyalgic syndrome have a lower melatonin secretion during the hours of darkness than healthy subjects. This may contribute to impaired sleep at night, fatigue during the day, and changed pain perception.

Incretins, insulin secretion and Type 2 diabetes mellitus

DEFF Research Database (Denmark)

Vilsbøll, Tina; Holst, Jens Møller

2004-01-01

the genes encoding their receptors have been deleted. In patients with Type 2 diabetes, the incretin effect is either greatly impaired or absent, and it is assumed that this could contribute to the inability of these patients to adjust their insulin secretion to their needs. In studies of the mechanism...... of the impaired incretin effect in Type 2 diabetic patients, it has been found that the secretion of GIP is generally normal, whereas the secretion of GLP-1 is reduced, presumably as a consequence of the diabetic state. It might be of even greater importance that the effect of GLP-1 is preserved whereas...... the effect of GIP is severely impaired. The impaired GIP effect seems to have a genetic background, but could be aggravated by the diabetic state. The preserved effect of GLP-1 has inspired attempts to treat Type 2 diabetes with GLP-1 or analogues thereof, and intravenous GLP-1 administration has been shown...

Incretins, insulin secretion and Type 2 diabetes mellitus

DEFF Research Database (Denmark)

Vilsbøll, T; Holst, Jens Juul

2004-01-01

the effect of GIP is severely impaired. The impaired GIP effect seems to have a genetic background, but could be aggravated by the diabetic state. The preserved effect of GLP-1 has inspired attempts to treat Type 2 diabetes with GLP-1 or analogues thereof, and intravenous GLP-1 administration has been shown...... the genes encoding their receptors have been deleted. In patients with Type 2 diabetes, the incretin effect is either greatly impaired or absent, and it is assumed that this could contribute to the inability of these patients to adjust their insulin secretion to their needs. In studies of the mechanism...... of the impaired incretin effect in Type 2 diabetic patients, it has been found that the secretion of GIP is generally normal, whereas the secretion of GLP-1 is reduced, presumably as a consequence of the diabetic state. It might be of even greater importance that the effect of GLP-1 is preserved whereas...

Anvendelse af video som forberedelse til stationsbaseret eksamen i medicin og kirurgi

DEFF Research Database (Denmark)

Subhi, Yousif; Bitsch, Mikael

2014-01-01

aspects. On a Likert scale from 1 to 7 our video was rated 4 (interquartile range (IQR): 4-6). An informatory lecture was rated 4 (IQR: 3-5) and a rehearsal OSCE was rated 6 (IQR: 5-7). Video use peaked in the days up to OSCE. Accessibility should be improved by reaching out using the appropriate tools...

Sphingomyelin synthases regulate protein trafficking and secretion.

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Marimuthu Subathra

Full Text Available Sphingomyelin synthases (SMS1 and 2 represent a class of enzymes that transfer a phosphocholine moiety from phosphatidylcholine onto ceramide thus producing sphingomyelin and diacylglycerol (DAG. SMS1 localizes at the Golgi while SMS2 localizes both at the Golgi and the plasma membrane. Previous studies from our laboratory showed that modulation of SMS1 and, to a lesser extent, of SMS2 affected the formation of DAG at the Golgi apparatus. As a consequence, down-regulation of SMS1 and SMS2 reduced the localization of the DAG-binding protein, protein kinase D (PKD, to the Golgi. Since PKD recruitment to the Golgi has been implicated in cellular secretion through the trans golgi network (TGN, the effect of down-regulation of SMSs on TGN-to-plasma membrane trafficking was studied. Down regulation of either SMS1 or SMS2 significantly retarded trafficking of the reporter protein vesicular stomatitis virus G protein tagged with GFP (VSVG-GFP from the TGN to the cell surface. Inhibition of SMSs also induced tubular protrusions from the trans Golgi network reminiscent of inhibited TGN membrane fission. Since a recent study demonstrated the requirement of PKD activity for insulin secretion in beta cells, we tested the function of SMS in this model. Inhibition of SMS significantly reduced insulin secretion in rat INS-1 cells. Taken together these results provide the first direct evidence that both enzymes (SMS1 and 2 are capable of regulating TGN-mediated protein trafficking and secretion, functions that are compatible with PKD being a down-stream target for SMSs in the Golgi.

Choline or methionine reverses impaired secretion of VLDL by hepatocytes from choline-deficient rats

International Nuclear Information System (INIS)

Yao, Z.; Vance, D.E.

1987-01-01

Male rats fed a choline-deficient (CD) diet for three days accumulated triacylglycerol (TG) in the liver. Hepatocytes from these rats were cultured and maintained in a medium + choline. The rate of secretion of TG was reduced by 50% in the CD cells. Correspondingly, [ 3 H]oleate and [ 3 H]glycerol were incorporated at a 2-fold higher rate into TG secreted by choline-supplemented cells compared to CD cells. Isolation of lipoprotein fractions by ultracentrifugation showed that the reduced secretion of TG by CD hepatocytes was mainly due to an impaired secretion of very low density lipoprotein (VLDL). Incorporation of [ 3 H]leucine into secreted apoB/sub H/, apoB/sub L/ and apoE was markedly reduced in CD cells compared to choline-supplemented cells. Secretion of high density lipoprotein was not reduced in the CD hepatocytes. Normal secretion of VLDL was resumed upon addition of methionine to the CD cells

Gastrin is not a physiological regulator of pancreatic exocrine secretion in the dog

International Nuclear Information System (INIS)

Koehler, E.; Beglinger, C.; Eysselein, V.; Groetzinger, U.; Gyr, K.

1987-01-01

The role of gastrin as a regulator of exocrine pancreatic secretion has not been proven adequately. In the present study the authors therefore compared the relative molar potencies of sulfated and unsulfated gastrin 17 with structurally related CCK peptides (synthetic CCK-8 and natural porcine CCK-33) in stimulating exocrine pancreatic secretion in conscious dogs. Dose response curves were constructed for pancreatic and gastric acid secretion. Plasma gastrin levels after exogenous gastrin 17-I and -II were compared with postprandial gastrin concentrations. The molar potency estimates calculated with synthetic CCK8 as standard for pancreatic protein secretion were natural porcine 50% pure CCK-33 1.60, gastrin 17-I 0.12, and gastrin 17-II 0.16. All four peptides induced a dose-dependent increase in pancreatic bicarbonate output. However, the blood concentrations needed to stimulate pancreatic secretion were above the postprandial gastrin levels. The data indicate that both gastrin 17 peptides are not physiological regulators of pancreatic enzyme secretion in dogs

Por secretion system-dependent secretion and glycosylation of Porphyromonas gingivalis hemin-binding protein 35.

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Mikio Shoji

Full Text Available The anaerobic Gram-negative bacterium Porphyromonas gingivalis is a major pathogen in severe forms of periodontal disease and refractory periapical perodontitis. We have recently found that P. gingivalis has a novel secretion system named the Por secretion system (PorSS, which is responsible for secretion of major extracellular proteinases, Arg-gingipains (Rgps and Lys-gingipain. These proteinases contain conserved C-terminal domains (CTDs in their C-termini. Hemin-binding protein 35 (HBP35, which is one of the outer membrane proteins of P. gingivalis and contributes to its haem utilization, also contains a CTD, suggesting that HBP35 is translocated to the cell surface via the PorSS. In this study, immunoblot analysis of P. gingivalis mutants deficient in the PorSS or in the biosynthesis of anionic polysaccharide-lipopolysaccharide (A-LPS revealed that HBP35 is translocated to the cell surface via the PorSS and is glycosylated with A-LPS. From deletion analysis with a GFP-CTD[HBP35] green fluorescent protein fusion, the C-terminal 22 amino acid residues of CTD[HBP35] were found to be required for cell surface translocation and glycosylation. The GFP-CTD fusion study also revealed that the CTDs of CPG70, peptidylarginine deiminase, P27 and RgpB play roles in PorSS-dependent translocation and glycosylation. However, CTD-region peptides were not found in samples of glycosylated HBP35 protein by peptide map fingerprinting analysis, and antibodies against CTD-regions peptides did not react with glycosylated HBP35 protein. These results suggest both that the CTD region functions as a recognition signal for the PorSS and that glycosylation of CTD proteins occurs after removal of the CTD region. Rabbits were used for making antisera against bacterial proteins in this study.

Sensibilidade corneana e secreção lacrimal após LASIK Corneal sensivity and tear secretion after LASIK

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Marcelo Guimarães Brandão Rêgo

2003-01-01

.29. Corneal sensitivity was measured with a Cochet-Bonnet esthesiometer in the central region of the cornea. Tear secretion was evaluated by the Schirmer test, basal secretion, breakup time test and symptoms. Examinations were performed before and 7, 30, 90, 180, and 270 days after surgery, or until full recovery. RESULTS: Median preoperative corneal sensitivity was 60 mm (range, 50 to 60 mm; median Schirmer test was 21.5 mm (range, 10 to 30 mm; median basal secretion was 11.5 mm (range, 6 to 20 mm; median breakup time test was 16.0 seconds (range, 8 to 22 seconds. All patients recovered their preoperative corneal sensitivity and tear secretion values between 90 to 180 days after surgery. During 9 months of follow-up, 5 patients (10 eyes did not present any dry eye symptom. CONCLUSION: After LASIK, the corneal sensitivity and tear secretion are decreased as long as for 6 months. During the postoperative period, 73.6% of the patients had dry eye symptoms. Further studies are required to best evaluate the effects on the corneal physiology.

Increases in cellular calcium concentration stimulate pepsinogen secretion from dispersed chief cells

International Nuclear Information System (INIS)

Raufman, J.P.; Berger, S.; Cosowsky, L.; Straus, E.

1986-01-01

Intracellular calcium concentration ([Ca]i) and pepsinogen secretion from dispersed chief cells from guinea pig stomach were determined before and after stimulation with calcium ionophores. [Ca]i was measured using the fluorescent probe quin2. Basal [Ca]i was 105 +/- 4 nM. Pepsinogen secretion was measured with a new assay using 125 I-albumin substrate. This assay is 1000-fold more sensitive than the widely-used spectrophotometric assay, technically easy to perform, rapid, and relatively inexpensive. The kinetics and stoichiometry of ionophore-induced changes in [Ca]i and pepsinogen secretion were similar. These data support a role for calcium as a cellular mediator of pepsinogen secretion

Catechin secretion and phytotoxicity: Fact not fiction.

Science.gov (United States)

Bais, Harsh P; Kaushik, Shail

2010-09-01

Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the "novel weapons hypothesis (NWH)." Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1-3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin.

Alkaline pH Is a signal for optimal production and secretion of the heat labile toxin, LT in enterotoxigenic Escherichia coli (ETEC.

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Lucia Gonzales

Full Text Available Enterotoxigenic Escherichia coli (ETEC cause secretory diarrhea in children and travelers to endemic areas. ETEC spreads through the fecal-oral route. After ingestion, ETEC passes through the stomach and duodenum before it colonizes the lower part of the small intestine, exposing bacteria to a wide range of pH and environmental conditions. This study aimed to determine the impact of external pH and activity of the Cyclic AMP receptor protein (CRP on the regulation of production and secretion of heat labile (LT enterotoxin. ETEC strain E2863wt and its isogenic mutant E2863ΔCRP were grown in LBK media buffered to pH 5, 7 and 9. GM1 ELISA, cDNA and cAMP analyses were carried out on bacterial pellet and supernatant samples derived from 3 and 5 hours growth and from overnight cultures. We confirm that CRP is a repressor of LT transcription and production as has been shown before but we show for the first time that CRP is a positive regulator of LT secretion both in vitro and in vivo. LT secretion increased at neutral to alkaline pH compared to acidic pH 5 where secretion was completely inhibited. At pH 9 secretion of LT was optimal resulting in 600 percent increase of secreted LT compared to unbuffered LBK media. This effect was not due to membrane leakage since the bacteria were viable at pH 9. The results indicate that the transition to the alkaline duodenum and/or exposure to high pH close to the epithelium as well as activation of the global transcription factor CRP are signals that induce secretion of the LT toxin in ETEC.

Baseline Goblet Cell Mucin Secretion in the Airways Exceeds Stimulated Secretion over Extended Time Periods, and Is Sensitive to Shear Stress and Intracellular Mucin Stores.

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Yunxiang Zhu

Full Text Available Airway mucin secretion studies have focused on goblet cell responses to exogenous agonists almost to the exclusion of baseline mucin secretion (BLMS. In human bronchial epithelial cell cultures (HBECCs, maximal agonist-stimulated secretion exceeds baseline by ~3-fold as measured over hour-long periods, but mucin stores are discharged completely and require 24 h for full restoration. Hence, over 24 h, total baseline exceeds agonist-induced secretion by several-fold. Studies with HBECCs and mouse tracheas showed that BLMS is highly sensitive to mechanical stresses. Harvesting three consecutive 1 h baseline luminal incubations with HBECCs yielded equal rates of BLMS; however, lengthening the middle period to 72 h decreased the respective rate significantly, suggesting a stimulation of BLMS by the gentle washes of HBECC luminal surfaces. BLMS declined exponentially after washing HBECCs (t1/2 = 2.75 h, to rates approaching zero. HBECCs exposed to low perfusion rates exhibited spike-like increases in BLMS when flow was jumped 5-fold: BLMS increased >4 fold, then decreased within 5 min to a stable plateau at 1.5-2-fold over control. Higher flow jumps induced proportionally higher BLMS increases. Inducing mucous hyperplasia in HBECCs increased mucin production, BLMS and agonist-induced secretion. Mouse tracheal BLMS was ~6-fold higher during perfusion, than when flow was stopped. Munc13-2 null mouse tracheas, with their defect of accumulated cellular mucins, exhibited similar BLMS as WT, contrary to predictions of lower values. Graded mucous metaplasia induced in WT and Munc13-2 null tracheas with IL-13, caused proportional increases in BLMS, suggesting that naïve Munc13-2 mouse BLMS is elevated by increased mucin stores. We conclude that BLMS is, [i] a major component of mucin secretion in the lung, [ii] sustained by the mechanical activity of a dynamic lung, [iii] proportional to levels of mucin stores, and [iv] regulated differentially from agonist

Baseline Goblet Cell Mucin Secretion in the Airways Exceeds Stimulated Secretion over Extended Time Periods, and Is Sensitive to Shear Stress and Intracellular Mucin Stores

Science.gov (United States)

Doyle, Sean P.; Nguyen, Kristine; Ribeiro, Carla M. P.; Vasquez, Paula A.; Forest, M. Gregory; Lethem, Michael I.; Dickey, Burton F.; Davis, C. William

2015-01-01

Airway mucin secretion studies have focused on goblet cell responses to exogenous agonists almost to the exclusion of baseline mucin secretion (BLMS). In human bronchial epithelial cell cultures (HBECCs), maximal agonist-stimulated secretion exceeds baseline by ~3-fold as measured over hour-long periods, but mucin stores are discharged completely and require 24 h for full restoration. Hence, over 24 h, total baseline exceeds agonist-induced secretion by several-fold. Studies with HBECCs and mouse tracheas showed that BLMS is highly sensitive to mechanical stresses. Harvesting three consecutive 1 h baseline luminal incubations with HBECCs yielded equal rates of BLMS; however, lengthening the middle period to 72 h decreased the respective rate significantly, suggesting a stimulation of BLMS by the gentle washes of HBECC luminal surfaces. BLMS declined exponentially after washing HBECCs (t1/2 = 2.75 h), to rates approaching zero. HBECCs exposed to low perfusion rates exhibited spike-like increases in BLMS when flow was jumped 5-fold: BLMS increased >4 fold, then decreased within 5 min to a stable plateau at 1.5–2-fold over control. Higher flow jumps induced proportionally higher BLMS increases. Inducing mucous hyperplasia in HBECCs increased mucin production, BLMS and agonist-induced secretion. Mouse tracheal BLMS was ~6-fold higher during perfusion, than when flow was stopped. Munc13-2 null mouse tracheas, with their defect of accumulated cellular mucins, exhibited similar BLMS as WT, contrary to predictions of lower values. Graded mucous metaplasia induced in WT and Munc13-2 null tracheas with IL-13, caused proportional increases in BLMS, suggesting that naïve Munc13-2 mouse BLMS is elevated by increased mucin stores. We conclude that BLMS is, [i] a major component of mucin secretion in the lung, [ii] sustained by the mechanical activity of a dynamic lung, [iii] proportional to levels of mucin stores, and [iv] regulated differentially from agonist-induced mucin

A genome-wide RNAi screen identifies regulators of cholesterol-modified hedgehog secretion in Drosophila.

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Reid Aikin

Full Text Available Hedgehog (Hh proteins are secreted molecules that function as organizers in animal development. In addition to being palmitoylated, Hh is the only metazoan protein known to possess a covalently-linked cholesterol moiety. The absence of either modification severely disrupts the organization of numerous tissues during development. It is currently not known how lipid-modified Hh is secreted and released from producing cells. We have performed a genome-wide RNAi screen in Drosophila melanogaster cells to identify regulators of Hh secretion. We found that cholesterol-modified Hh secretion is strongly dependent on coat protein complex I (COPI but not COPII vesicles, suggesting that cholesterol modification alters the movement of Hh through the early secretory pathway. We provide evidence that both proteolysis and cholesterol modification are necessary for the efficient trafficking of Hh through the ER and Golgi. Finally, we identified several putative regulators of protein secretion and demonstrate a role for some of these genes in Hh and Wingless (Wg morphogen secretion in vivo. These data open new perspectives for studying how morphogen secretion is regulated, as well as provide insight into regulation of lipid-modified protein secretion.

Glutamine-Elicited Secretion of Glucagon-Like Peptide 1 Is Governed by an Activated Glutamate Dehydrogenase.

Science.gov (United States)

Andersson, Lotta E; Shcherbina, Liliya; Al-Majdoub, Mahmoud; Vishnu, Neelanjan; Arroyo, Claudia Balderas; Aste Carrara, Jonathan; Wollheim, Claes B; Fex, Malin; Mulder, Hindrik; Wierup, Nils; Spégel, Peter

2018-03-01

Glucagon-like peptide 1 (GLP-1), secreted from intestinal L cells, glucose dependently stimulates insulin secretion from β-cells. This glucose dependence prevents hypoglycemia, rendering GLP-1 analogs a useful and safe treatment modality in type 2 diabetes. Although the amino acid glutamine is a potent elicitor of GLP-1 secretion, the responsible mechanism remains unclear. We investigated how GLP-1 secretion is metabolically coupled in L cells (GLUTag) and in vivo in mice using the insulin-secreting cell line INS-1 832/13 as reference. A membrane-permeable glutamate analog (dimethylglutamate [DMG]), acting downstream of electrogenic transporters, elicited similar alterations in metabolism as glutamine in both cell lines. Both DMG and glutamine alone elicited GLP-1 secretion in GLUTag cells and in vivo, whereas activation of glutamate dehydrogenase (GDH) was required to stimulate insulin secretion from INS-1 832/13 cells. Pharmacological inhibition in vivo of GDH blocked secretion of GLP-1 in response to DMG. In conclusion, our results suggest that nonelectrogenic nutrient uptake and metabolism play an important role in L cell stimulus-secretion coupling. Metabolism of glutamine and related analogs by GDH in the L cell may explain why GLP-1 secretion, but not that of insulin, is activated by these secretagogues in vivo. © 2017 by the American Diabetes Association.

Radioimmunoassay of glicagon secretion in diabetes mellitus

International Nuclear Information System (INIS)

Milanova, St.; Koparanova, O.; Milkov, V.; Visheva, N.; Kurtev, I.; Maleeva, A.

1988-01-01

Radioimunoassay of glucagon, lh, fsh, aldosterone, cortisol, acth, sth and lth was performed using preparations from the firms SORIN, AMERSHAM and HOECHST. The basal glucagon secretion was estimated in 403 diabetic patients and 84 normal subjects. It was transitorily suppressed by glucose. The alpha-cellular reactivity in diabetic patients was stimulated by insulin-induced hypoglycemia and with arginine and vasopressin. The tested group of diabetic patients had absolute hyperglucagonemia, despite the hyperglycemia, which is an evidence of abnormal alpha-cellular function. The insulin-dependent nature of hyperglucagonemia in diabetes mellitus and the hyperreactivity of glucagon secretion after protein stimulation was demonstrated. The correlation of these results leads to essential diagnostic inferences

A new (k,n verifiable secret image sharing scheme (VSISS

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Amitava Nag

2014-11-01

Full Text Available In this paper, a new (k,n verifiable secret image sharing scheme (VSISS is proposed in which third order LFSR (linear-feedback shift register-based public key cryptosystem is applied for the cheating prevention and preview before decryption. In the proposed scheme the secret image is first partitioned into several non-overlapping blocks of k pixels. Every k pixel is then used to form m=⌈k/4⌉+1 pixels of one encrypted share. The original secret image can be reconstructed by gathering any k or more encrypted shared images. The experimental results show that the proposed VSISS is an efficient and safe method.

Noncoherent capacity of secret-key agreement with public discussion

KAUST Repository

Agrawal, Anurag

2011-09-01

We study the noncoherent capacity of secret-key agreement with public discussion over independent identically distributed (i.i.d.) Rayleigh fading wireless channels, where neither the sender nor the receivers have access to instantaneous channel state information (CSI). We present two results. At high signal-to-noise ratio (SNR), the secret-key capacity is bounded in SNR, regardless of the number of antennas at each terminal. Second, for a system with a single antenna at both the legitimate and the eavesdropper terminals and an arbitrary number of transmit antennas, the secret-key capacity-achieving input distribution is discrete, with a finite number of mass points. Numerically we observe that at low SNR, the capacity achieving distribution has two mass points with one of them at the origin. © 2011 IEEE.

Noncoherent capacity of secret-key agreement with public discussion