Search results for "Fragment"

Fibril formation and toxicity of the non-amyloidogenic rat amylin peptide.

2012

Full-length native rat amylin 1-37 has previously been widely shown to be unable to form fibrils and to lack the toxicity of the human amylin form leading to its use as a non-amyloidogenic control peptide. A recent study has suggested that rat amylin 1-37 forms amyloidogenic β-sheet structures in the presence of the human amylin form and suggested that this property could promote toxicity. Using TEM analysis we show here fibril formation by synthetic rat amylin 1-37 and 8-37 peptides when the lyophilized HPLC purified peptides are initially dissolved in 20 mM Tris-HCl. Dissolution of synthetic rat amylin 1-37 and 8-37 peptides in H(2)O or phosphate buffered saline failed to produce fibrils.…

New biological aspects of Chromogranin A-derived peptides: Focus on vasostatins

2007

Chromogranin A (CgA), one component of the granin family, represents the major soluble protein co-stored and co-released with catecholamines, within chromaffin cells secretory granules. It is considered a diagnostic and prognostic marker of several diseases, including a variety of tumours and cardiac heart failure. It also represents a precursor of biologically active fragments, generated after proteolytic cleavage at the level of the multiple pairs of dibasic sites which enrich its sequence. CgA, and its derived fragments show an old evolutionary history being ubiquitously present throughout the animal word, from mammals to invertebrates. Their biological functions include control of hormo…

APOPTOTIC ANALYSIS OF CUMULUS CELLS FOR THE SELECTION OF COMPETENT OOCYTES TO BE FERTILIZED BY INTRACYTOPLASMIC SPERM INJECTION (ICSI)

2015

Oocyte quality is one of the main factors for the success of in vitro fertilization protocols. Apoptosis is known to affect oocyte quality and may impair subsequent embryonic development and implantation. The aim of this study was to investigate the apoptosis rate of single and pooled cumulus cells of cumulus cell–oocyte complexes (COCs), as markers of oocyte quality, prior to intracytoplasmatic sperm injection (ICSI).We investigated the apoptosis rate by TUNEL assay (DNA fragmentation) and caspase-3 immunoassay of single and pooled cumulus cells of COCs. The results showed that DNA fragmentation in cumulus cells was remarkably lower in patients who achieved a pregnancy than in those who di…

Human recombinant vasostatin-1 may interfere with cell-extracellular matrix interactions

2006

Vasostatin-1 (VS-1), the N-terminal fragment derived from the cleavage of chromogranin A (CgA), has been shown to exert several biological activities on several tissues and organs. Recently, it has been reported that human recombinant VS-1 (STA-CGA(1-78)) may alter myocardial contractility in eel, frog., and rat hearts. In this article we have explored if STA-CGA(1-78) can induce intracellular cascades interacting both with adhesion molecules and/or extracellular matrix (ECM), components, that is, involvement of the heat shock protein 90 (HSP90) and the endothelial NOS (eNOS), known to be implicated in signal transduction mechanisms affecting myocardial contractility. We used 3D cultured ad…

Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations.

2007

Abstract A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro , the effects of the recombinant vasostatin 1–78 (VS-1), CGA 7–57 and CGA 47–66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7–57 and CGA 47–66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53–57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), b…

Antioxidants in ICSI

2013

Male factor infertility can be caused by reasons, either related or not with total sperm production. Among causes of male infertility in cases of normal sperm count and motility, oxidative stress is one of the most relevant processes influencing fertility in vivo or in assisted reproduction treatments’ results. This chapter provides the most updated information regarding the oxidative stress situation in sperm and the relevance of antioxidants use in intracytoplasmic sperm injection results.

Genetic diversity in the wild : cyclic population dynamics and population isolation

2013

Comparing the Climatic and Landscape Risk Factors for Lyme Disease Cases in the Upper Midwest and Northeast United States

2020

Lyme disease, recognized as one of the most important vector-borne diseases worldwide, has been increasing in incidence and spatial extend in United States. In the Northeast and Upper Midwest, Lyme disease is transmitted by Ixodes scapularis. Currently, many studies have been conducted to identify factors influencing Lyme disease risk in the Northeast, however, relatively few studies focused on the Upper Midwest. In this study, we explored and compared the climatic and landscape factors that shape the spatial patterns of human Lyme cases in these two regions, using the generalized linear mixed models. Our results showed that climatic variables generally had opposite correlations with Lyme d…

Unrest at the Nevados de Chillán volcanic complex: a failed or yet to unfold magmatic eruption?

2018

Resuming erupting activity at volcanoes that have been long quiescent poses a significant challenge to hazard assessment, as it require assessment of whether the change in activity is an isolated event or the beginning of a new eruptive sequence. Such inception is often poorly characterised as quiescent volcanoes tend to be poorly equipped and not extensively monitored, especially with respect to gas geochemistry. Here, we report gas composition and flux measurements from a newly opened vent at the very onset of eruptive activity at the Nevados de Chillán volcanic complex (Chile) in January-February 2016. The molar proportions of H2O, CO2, SO2, H2S and H2 gases are found to be 98.4, 0.97, 0…

Upper Caraş River (Danube watershed) fish populations fragmentation – technical rehabilitation proposal

2017

Abstract We propose a technical solution for fish movement based on the flow of water over a spill threshold. Such barriers are common in the Danube system. The proposed system has a range of operating components which are easily detachable from the spill threshold, are resistant to corrosion and will not harm the fish. In fact, if designed to complement swimming abilities of target fish, it should provide adequate passage for both adults and juveniles. If implemented correctly, the design may offer a solution to help displaced fish recolonize upstream habitats.