Antimicrobial peptide LL-37 and recombinant human mannose-binding lectin express distinct age- and pathogen-specific antimicrobial activity in human newborn cord blood in vitro

Background: There is a need to prevent and treat infection in newborns. One approach is administration of antimicrobial proteins and peptides (APPs) such as LL-37, a membrane-active cathelicidin antimicrobial peptide, and mannose-binding lectin (MBL), a pattern-recognition protein that binds to microbial surface polysaccharides resulting in opsonization and complement activation. Low plasma/serum levels of LL-37 and of MBL have been correlated with infection and exogenous administration of these agents may enhance host defense. Methods: The antimicrobial activity of LL-37 (15 µg/ml) or rMBL (0.5, 2 and 10 µg/ml) was tested in hirudin-anticoagulated preterm and term human cord blood (N = 12-14) against Staphylococcus aureus (SA) USA 300 (2x10 4 CFU/ml), Staphylococcus epidermis (SE) 1457 (2x10 4 CFU/ml) and Candida albicans (CA) SC5314 (1x10 4 CFU/ml). After incubation (1, 45, or 180 min), CFUs were enumerated by plating blood onto agar plates. Supernatants were collected for measurement of MBL via ELISA. Results: Preterm cord blood demonstrated impaired endogenous killing capacity against SA and SE compared to term blood. Addition of LL-37 strongly enhanced antimicrobial/antifungal activity vs SA, SE and CA in term blood and SE and CA in preterm blood. By contrast, rMBL showed modest fungistatic activity vs CA in a sub-analysis of term newborns with high basal MBL levels. Baseline MBL levels varied within preterm and term cohorts with no correlation to gestational age. In summary, exogenous LL-37 demonstrated significant antimicrobial activity against SA, SE and CA in term and SE and CA in preterm human blood tested in vitro. rMBL demonstrated modest antifungal activity in term cord blood of individuals with high baseline MBL levels. Conclusions: To the extent that our in vitro results predict the effects of APPs in vivo, development of APPs for prevention and treatment of infection should take into account host age as well as the target pathogen

Pertanggung jawaban hukum terhadap pelaksanaan Perjanjian pemberangkatan ibadah haji antara Biro penyelenggara ibadah haji khusus Dengan calon jamaah haji plus (studi kasus di pt. Nur ramadhan wisata cabang yogyakarta)

Penelitian ini bertujuan untuk mengetahui hak serta kewajiban antara PT. Nur Ramadhan Wisata Cabang Yogyakarta terhadap Calon Jamaah Haji yang akan melakukan ibadah haji di Tanah Suci, untuk mengetahui pelaksanaan perjanjian PT. Nur Ramadhan Wisata Cabang Yogyakarta terhadap pemberangkatan calon jamaah Haji Plus, dan untuk mengetahui bagaimana tanggung jawab hukum yang dilakukan apabila salah satu pihak melakukan wanprestasi. Metode penelitian yang digunakan bersifat yuridis empiris yang bersifat deskriptif yakni pada Kantor PT. Nur Ramadhan Wisata Cabang Yogyakarta. Sumber data terdiri dari data primer dan data sekunder. Sedangkan metode pengumpulan data melalui tiga tahap yaitu kepustakaan, observasi dan wawancara dengan narasumber yakni pimpinan PT. Nur Ramadhan Wisata Cabang Yogyakarta. Hasil penelitian menunjukkan bahwa hak penyelenggara adalah menetapkan biaya dan menerima biaya pemberangkatan Haji Plus, sedangkan kewajiban penyelenggara adalah melayani calon jemaah haji dari mulai pemberangkatan sampai memulangkan jemaah haji. Adapun pelaksanaan perjanjian pemberangkatan Ibadah Haji Plus antara Biro Penyelenggara Ibadah Haji Khusus dengan calon jamaah Haji plus secara tertulis agar masing-masing mendapatkan suatu perlindungan, serta untuk mengantisipasi adanya wanprestasi antara kedua belah pihak, serta tanggung jawab hukum yang dilakukan apabila salah satu pihak melakukan wanprestasi dapat diselesaikan dengan damai yakni musyawarah dan apabila belum dapat menerima tentang pelanggaran dapat melakukan tuntutan di Pengadilan

Leptin-dependent Phosphorylation of PTEN Mediates Actin Restructuring and Activation of ATP-sensitive K+ Channels

Leptin activates multiple signaling pathways in cells, including the phosphatidylinositol 3-kinase pathway, indicating a degree of cross-talk with insulin signaling. The exact mechanisms by which leptin alters this signaling pathway and how it relates to functional outputs are unclear at present. A previous study has established that leptin inhibits the activity of the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome 10), an important tumor suppressor and modifier of phosphoinositide signaling. In this study we demonstrate that leptin phosphorylates multiple sites on the C-terminal tail of PTEN in hypothalamic and pancreatic β-cells, an action not replicated by insulin. Inhibitors of the protein kinases CK2 and glycogen synthase kinase 3 (GSK3) block leptin-mediated PTEN phosphorylation. PTEN phosphorylation mutants reveal the critical role these sites play in transmission of the leptin signal to F-actin depolymerization. CK2 and GSK3 inhibitors also prevent leptin-mediated F-actin depolymerization and consequent ATP-sensitive K+ channel opening. GSK3 kinase activity is inhibited by insulin but not leptin in hypothalamic cells. Both hormones increase N-terminal GSK3 serine phosphorylation, but in hypothalamic cells this action of leptin is transient. Leptin, not insulin, increases GSK3 tyrosine phosphorylation in both cell types. These results demonstrate a significant role for PTEN in leptin signal transmission and identify GSK3 as a potential important signaling node contributing to divergent outputs for these hormones

Loss of AMP-activated protein kinase alpha 2 subunit in mouse beta-cells impairs glucose-stimulated insulin secretion and inhibits their sensitivity to hypoglycaemia

AMPK (AMP-activated protein kinase) signalling plays a key role in whole-body energy homoeostasis, although its precise role in pancreatic β-cell function remains unclear. In the present stusy, we therefore investigated whether AMPK plays a critical function in β-cell glucose sensing and is required for the maintenance of normal glucose homoeostasis. Mice lacking AMPKα2 in β-cells and a population of hypothalamic neurons (RIPCreα2KO mice) and RIPCreα2KO mice lacking AMPKα1 (α1KORIPCreα2KO) globally were assessed for whole-body glucose homoeostasis and insulin secretion. Isolated pancreatic islets from these mice were assessed for glucose-stimulated insulin secretion and gene expression changes. Cultured β-cells were examined electrophysiologically for their electrical responsiveness to hypoglycaemia. RIPCreα2KO mice exhibited glucose intolerance and impaired GSIS (glucose-stimulated insulin secretion) and this was exacerbated in α1KORIPCreα2KO mice. Reduced glucose concentrations failed to completely suppress insulin secretion in islets from RIPCreα2KO and α1KORIPCreα2KO mice, and conversely GSIS was impaired. β-Cells lacking AMPKα2 or expressing a kinase-dead AMPKα2 failed to hyperpolarize in response to low glucose, although KATP (ATP-sensitive potassium) channel function was intact. We could detect no alteration of GLUT2 (glucose transporter 2), glucose uptake or glucokinase that could explain this glucose insensitivity. UCP2 (uncoupling protein 2) expression was reduced in RIPCreα2KO islets and the UCP2 inhibitor genipin suppressed low-glucose-mediated wild-type mouse β-cell hyperpolarization, mimicking the effect of AMPKα2 loss. These results show that AMPKα2 activity is necessary to maintain normal pancreatic β-cell glucose sensing, possibly by maintaining high β-cell levels of UCP2

LINK-GUARD: an effective and scalable security framework for link discovery in SDN networks

Software-Defined Networking (SDN) is an emerging networking paradigm that creates new opportunities for future generations of networks. The main characteristic of SDN is its ability to centralise control through the decoupling of control decisions from the network switches to make the network more flexible, programmable, and scalable. As part of this centralised control management, the SDN controller maintains a holistic view of the underlying network. Therefore, topology discovery in SDN is an essential service for topology-aware applications, such as routing, load balancing, mobility, and tracking. However, during the SDN topology discovery process, the controllers, without proper protection, are vulnerable to topology poisoning attacks, most notably Link Fabrication Attacks (LFAs). LFAs may be mounted due to a leak of packet source authentication, the lack of packet integrity checks, or the reuse of static packets. In this paper, we describe an effective and scalable security framework, LINK-GUARD, used for facilitating secure link discoveries in an SDN network. LINK-GUARD is designed to detect and thwart LFAs, thus reducing the risks of network topology poisoning. The framework has been implemented and evaluated on a Mininet emulator with an RYU controller. The security analysis indicates that LINK-GUARD can effectively and efficiently secure topology discoveries against both host-based and switch-based link fabrication attacks. Performance evaluation results show that the legitimacy of new links can be verified nearly real-time, taking approximately 30 milliseconds, and fake links can be detected within as low as 6 milliseconds, with a negligible runtime overhead. These results show that LINK-GUARD is a scalable solution for dynamic and large SDN networks

ZFP36L1 negatively regulates plasmacytoid differentiation of BCL1 cells by targeting BLIMP1 mRNA

The ZFP36/Tis11 family of zinc-finger proteins regulate cellular processes by binding to adenine uridine rich elements in the 3′ untranslated regions of various mRNAs and promoting their degradation. We show here that ZFP36L1 expression is largely extinguished during the transition from B cells to plasma cells, in a reciprocal pattern to that of ZFP36 and the plasma cell transcription factor, BLIMP1. Enforced expression of ZFP36L1 in the mouse BCL1 cell line blocked cytokine-induced differentiation while shRNA-mediated knock-down enhanced differentiation. Reconstruction of regulatory networks from microarray gene expression data using the ARACNe algorithm identified candidate mRNA targets for ZFP36L1 including BLIMP1. Genes that displayed down-regulation in plasma cells were significantly over-represented (P = <0.0001) in a set of previously validated ZFP36 targets suggesting that ZFP36L1 and ZFP36 target distinct sets of mRNAs during plasmacytoid differentiation. ShRNA-mediated knock-down of ZFP36L1 in BCL1 cells led to an increase in levels of BLIMP1 mRNA and protein, but not for mRNAs of other transcription factors that regulate plasmacytoid differentiation (xbp1, irf4, bcl6). Finally, ZFP36L1 significantly reduced the activity of a BLIMP1 3′ untranslated region-driven luciferase reporter. Taken together, these findings suggest that ZFP36L1 negatively regulates plasmacytoid differentiation, at least in part, by targeting the expression of BLIMP1

Impact of Hash Value Truncation on ID Anonymity in Wireless Sensor Networks

Hash functions have been used to address security requirements such as integrity, message authentication and non-repudiation. In WSNs, these functions are also used to preserve sensor nodes' identity (ID) anonymity, i.e., they are used to generate and verify dynamic pseudonyms that are used to identify sensor nodes in a communication session. In this latter application, there is an open issue as to how long the output of a hash function (i.e. hash value) we should use in pseudonym generation. The longer the hash value, the longer is the pseudonym, thus the harder it is to guess a pseudonym that is generated by using a hash function. On the other hand, the use of a longer hash value also means that the bandwidth and energy costs in transmitting the pseudonym will be higher. As sensor nodes typically have limited resources and are battery powered, the balance between the protection level of ID anonymity and performance and energy costs incurred in providing such a protection is an open issue. This paper inves- tigates the use of hash value truncation in preserving ID anonymity in WSNs and the impact of hash value truncation on four criteria attributes (security against brute force attacks, probability of pseudonym collisions, energy trade- off and end-to-end packet delivery delay). It reports the possible impacts of other factors including the type and usage of hash functions, sensor node capabilities, adversary capabilities, ability to resolve pseudonym collisions, network density and data collection rate. The results show that the impacts of these factors may be contradictory. Therefore, the determination of an optimal level of hash value truncation should consider all trade-offs brought by these factors