Search results for " present"

Dynamics of CXC group chemokine platelet factor 4 (PF4) plasma levels in non-small cell lung cancer (NSCLC)

2012

CXC chemokines display pleiotropic effects participating not only in inflammation, but regulating angiogenesis and metastatic spread in cancer. Platelet factor 4 (PF4) is a 70-amino acid protein belonging to the CXC chemokine family. PF4 is also known as CXCL4. This chemokine is released from alpha-granules of activated platelets and binds with high affinity to heparin-like molecules promoting coagulation. Megakaryocytes respond to the presence of tumors by increasing their number in the bone marrow accompanied by increase in the number of platelets in circulation, causing changes in chemokine balance.

2017

From 2000 to 2015, tsunamis and storms killed more than 430,000 people worldwide and affected a further >530 million, with total damages exceeding US$970 billion. These alarming trends, underscored by the tragic events of the 2004 Indian Ocean catastrophe, have fueled increased worldwide demands for assessments of past, present, and future coastal risks. Nonetheless, despite its importance for hazard mitigation, discriminating between storm and tsunami deposits in the geological record is one of the most challenging and hotly contended topics in coastal geoscience. To probe this knowledge gap, we present a 4500-year reconstruction of “tsunami” variability from the Mediterranean based on str…

Synaptic Scaling Enables Dynamically Distinct Short- and Long-Term Memory Formation

2013

Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling – a slow process usually associated with the maintenance of activity homeostasis – combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The inter…

Shining castles and humans of metal/floral appearance ? metaphorical language in the Palaiologan romances Kallimachos and Velthandros

2019

About eight centuries after Heliodorus, the Greek novel resurfaced in the twelfth century, in Komnenian Byzantium, and again two centuries later under the Palaiologan dynasty. This latter literary revival was due to the political stability of the imperial Byzantine government, which promoted cultural production, rhetorical education, and patronage networks. Kallimachos and Velthandros, two Palaiologan romances presented as court literature, combine ancient and medieval tropes with rhetorical artistry to blur the boundaries between the artificial and the natural. Castles and objects made of precious metals thus resemble living, natural spaces, and human characters are portrayed in metallurgi…

Direct Evidence for Viral Antigen Presentation during Latent Cytomegalovirus Infection

2021

Murine models of cytomegalovirus (CMV) infection have revealed an immunological phenomenon known as “memory inflation” (MI). After a peak of a primary CD8+ T-cell response, the pool of epitope-specific cells contracts in parallel to the resolution of productive infection and the establishment of a latent infection, referred to as “latency.” CMV latency is associated with an increase in the number of cells specific for certain viral epitopes over time. The inflationary subset was identified as effector-memory T cells (iTEM) characterized by the cell surface phenotype KLRG1+CD127−CD62L−. As we have shown recently, latent viral genomes are not transcriptionally silent. Rather, viral genes are …

Modulation of accessory cell function of immortalized bone marrow-derived macrophages by granulocyte/macrophage colony-stimulating factor.

1993

To generate cloned macrophage populations with sensitivity towards granulocyte/macrophage colony-stimulating factor (GM-CSF), bone marrow-derived macrophages (BMM phi) were immortalized by transformation with SV40. A panel of transformed clones was established. The majority of clones represented independently derived transformants, as evidenced by restriction fragment length polymorphism using genomic DNA digested with EcoRI and TaqI and the 5.2 kb SV40 DNA for hybridization analysis. The cells belong to the macrophage lineage according to several criteria, e.g. the presence of nonspecific esterase, their phagocytic capacity and their morphology. Many clones were potent antigen-presenting c…

Proliferation and MHC-unrestricted bystander lysis by virus-specific cytotoxic T cells following antigen self-presentation.

1998

Cytotoxic T cells (CTL) not only act as effector cells, but can also serve as antigen-presenting cells (APC) for other CTL due to their expression of major histocompatibility complex (MHC) class I molecules. In the present study we show that independently derived CTL lines (CTLL) with specificity for an L(d)-presented nonapeptide corresponding to amino acids 168-176 of the immediate-early 1 (IE1) protein of murine cytomegalovirus not only lyse syngeneic but also allogeneic target cells, if the peptide is present during the cytolytic assay. Whereas a short peptide pulse is sufficient to render syngeneic cells susceptible to lysis, continued presence of soluble peptide is mandatory for the ly…

Major histocompatibility complex class II binding site for streptococcal pyrogenic (erythrogenic) toxin A.

1994

Streptococcal pyrogenic exotoxin A (SPEA) is an important pathogenicity factor of group A streptococci. It is a member of the family of „superantigens” produced by Staphylococcus aureus and Streptococcus pyogenes and its T lymphocyte stimulating activity is involved into the pathogenesis of certain diseases caused by pyogenic streptococci. In this study we have produced and characterized recombinant SPEA molecules in Escherichia coli. These molecules are indistinguishable from natural SPEA in both T cell stimulatory and HLA class II binding activities. Human class II molecules are more efficient than mouse class II molecules in presenting SPEA to T cells. In binding tests to major histocomp…

Fixed Costs Per Shipment

2011

Exporting firms do not only decide how much of their products they ship abroad but also at which frequency. Doing so, they face a trade-off between saving on fixed costs per shipments (by shipping large amounts infrequently) and saving on storage costs (by delivering just in time with small and frequent shipments). The firm's optimal choice defines a mapping from size and frequency of shipments to fixed costs per shipment. We use a unique dataset of Swiss cross-border trade on the transaction level to analyze the size and shape of the underlying fixed costs. The data suggest that for the average Swiss exporter the fixed costs per shipment are economically important: 0.82 percent of the valu…

Functional cysteine-less subunits of the transporter associated with antigen processing (TAP1 and TAP2) by de novo gene assembly

2002

AbstractWithin the adaptive immune system the transporter associated with antigen processing (TAP) plays a pivotal role in loading of peptides onto major histocompatibility (MHC) class I molecules. As a central tool to investigate the structure and function of the TAP complex, we created cysteine-less human TAP subunits by de novo gene synthesis, replacing all 19 cysteines in TAP1 and TAP2. After expression in TAP-deficient human fibroblasts, cysteine-less TAP1 and TAP2 are functional with respect to adenosine triphosphate (ATP)-dependent peptide transport and inhibition by ICP47 from herpes simplex virus. Cysteine-less TAP1 and TAP2 restore maturation and intracellular trafficking of MHC c…