Search results for "Precursors"
showing 10 items of 151 documents
Exogenous t-PA Administration Increases Hippocampal Mature BDNF Levels. Plasmin- or NMDA-Dependent Mechanism?
2014
International audience; Brain-derived neurotrophic factor (BDNF) through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA)/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA) receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (r)t-PA administration on brain BDNF metabo…
Behavioural and physiological effects of the trophically transmitted cestode parasite, Cyathocephalus truncatus, on its intermediate host, Gammarus p…
2007
SUMMARYSome parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. Gammarids infected by the tapeworm Cyathocephalus truncatus (Cestoda: Spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. In this study, we tested the hypothesis that C. truncatus is able to manipulate the behaviour of one of its intermediate hosts, Gammarus pulex (Crustacea: Amphipoda). To assess if any behavioural change was linked to other phenotypic alterations, we also measured the immunity of infected and u…
Immunohistochemical evidence for the presence of peptides derived from proenkephalin, prodynorphin and proopiomelanocortin in the guinea pig pineal g…
1988
By using a plethora of region-specific antisera, this light microscopic immunohistochemical study revealed that derivatives from the three opioid precursors, i.e. proenkephalin, prodynorphin and proopiomelanocortin are differentially distributed in the pineal gland of guinea pig. Various molecular forms of immunoreactive opioid peptides derived from proenkephalin or prodynorphin were present in a minority of pinealocytes as well as in nerves. In contrast to this dual distribution pattern of opioid-active peptides, the opioid-inactive derivative from proopiomelanocortin, alpha-melanocyte stimulating hormone, was exclusively present in a large proportion of pinealocytes. A multiple and differ…
Progastrin Represses the Alternative Activation of Human Macrophages and Modulates Their Influence on Colon Cancer Epithelial Cells
2014
Macrophage infiltration is a negative prognostic factor for most cancers but gastrointestinal tumors seem to be an exception. The effect of macrophages on cancer progression depends on their phenotype, which may vary between M1 (pro-inflammatory, defensive) to M2 (tolerogenic, pro-tumoral). Gastrointestinal cancers often become an ectopic source of gastrins and macrophages present receptors for these peptides. The aim of the present study is to analyze whether gastrins can affect the pattern of macrophage infiltration in colorectal tumors. We have evaluated the relationship between gastrin expression and the pattern of macrophage infiltration in samples from colorectal cancer and the influe…
Factors associated with plasma antigen carbohydrate 125 and amino-terminal pro-B-type natriuretic peptide concentrations in acute heart failure
2020
Background: Plasma amino-terminal pro-B-type natriuretic peptide and antigen carbohydrate 125 levels are positively associated with a higher risk of adverse clinical outcomes in acute heart failure. As a proxy of congestion, antigen carbohydrate 125 has also been proposed as a right-sided heart failure marker. Thus, we aimed to determine in this population the main factors – including echocardiographic right-sided heart failure parameters – associated with antigen carbohydrate 125 and amino-terminal pro-B-type natriuretic peptide. Methods and results: We prospectively included 2949 patients admitted with acute heart failure. Amino-terminal pro-B-type natriuretic peptide and antigen carbohy…
Presepsin and Midregional Proadrenomedullin in Pediatric Oncologic Patients with Febrile Neutropenia
2020
Abstract Objective In this study, we investigated the roles of presepsin (PSP) and midregional proadrenomedullin (mr-proADM) in children with febrile neutropenia (FN) due to chemotherapy. Methods We assessed 36 FN episodes in 26 children. Patients were classified into bacteremia (B) and fever of unknown origin (FUO) groups. We evaluated PSP and mr-proADM at admission (T0), after 24/48 h (T1), and after 5 days (T2). Results PSP and mr-proADM levels were elevated at T0 and significantly decreased at T2. mr-proADM levels did not significantly differ between the B and FUO groups. PSP levels significantly differed between the B and FUO groups only at T1. Both PSP and mr-proADM levels at T0 were …
Synthesis of YAG nanopowder by the co-precipitation method: Influence of pH and study of the reaction mechanisms
2012
International audience; YAG nanopowders with an average grain size of 30 nm have been successfully synthesized by the co-precipitation method using nitrates with precipitant of ammonium hydrogen carbonate. The influence of precipitation conditions such as pH, aging time and calcination temperature on the formation of secondary phases has been studied. The accurate control of pH value at every stage of precipitation process is crucial to avoid the presence of YAM (Yttrium Aluminium Monoclinic, Y4Al2O9) and yttrium oxide (Y2O3) after calcination. The reaction mechanisms have been investigated using different techniques such as infrared spectroscopy, x-ray diffraction and thermal analyses. The…
Reaction pathways for atomic layer deposition with lithium hexamethyl disilazide, trimethyl phosphate, and oxygen plasma
2020
Atomic layer deposition (ALD) of lithium-containing films is of interest for the development of next-generation energy storage devices. Lithium hexamethyl disilazide (LiHMDS) is an established precursor to grow these types of films. The LiHMDS molecule can either be used as a single-source precursor molecule for lithium or as a dual-source precursor molecule for lithium and silicon. Single-source behavior of LiHMDS is observed in the deposition process with trimethylphosphate (TMP) resulting in the deposition of crystalline lithium phosphate (Li3PO4). In contrast, LiHMDS exhibits dual-source behavior when combined with O2 plasma, resulting in a lithium silicate. Both processes were characte…
Thermal and plasma enhanced atomic layer deposition of SiO2 using commercial silicon precursors
2014
In this paper, we report ALD deposition of silicon dioxide using either thermal or plasma enhanced atomic layer deposition (PEALD). Several aminosilanes with differing structures and reactivity were used as silicon precursors in R&D single wafer ALD tools. One of the precursors was also tested on pilot scale batch ALD using O3 as oxidant and with substrates measuring 150 × 400 mm. The SiO2 film deposition rate was greatly dependent on the precursors used, highest values being 1.5-2.0 Å/cycle at 30-200°C for one precursor with an O2 plasma. According to time-of-flight-elastic recoil detection analysis measurements carbon and nitrogen impurities were relatively low, but hydrogen content i…
Cytochalasin B selectively releases ovalbumin mRNA precursors but not the mature ovalbumin mRNA from hen oviduct nuclear matrix
1987
Hen oviduct nuclear matrix-bound mature ovalbumin mRNA is released from the matrix in the presence of ATP, while the ovalbumin mRNA precursors remain bound to this structure. Detachment of the mature mRNA from the matrix by ATP as well as ATP-dependent efflux of mRNA from isolated nuclei were found to be inhibited by cytochalasin B. On the other hand, in the absence of ATP, cytochalasin B exclusively caused the release (and nucleocytoplasmic efflux) of the ovalbumin messenger precursors, but not of the mature mRNA. After cytochalasin B treatment, actin could be detected in the matrix supernatant. Phalloidin which stabilizes actin filaments did not cause RNA liberation in the absence of ATP,…