Search results for "toxin"

Binding Sites for Neurotoxins and Cholinergic Ligands in Peripheral and Neuronal Nicotinic Receptors Studies with Synthetic Receptor Sequencesa

1995

Further link between complement activation and blood coagulation

1977

EVIDENCE for interactions between the complement and haemostatic systems has come from two lines of research—blood platelets have been shown to interact with various complement components1–6, and more ambiguous results have been obtained with respect to the role of complement in endotoxin shock and the Shwartzman reaction7–13. We report here that the activated complement component C3b triggers a marked increase of tissue thromboplastin (factor III) activity in cultured human monocytes. Differential counting and nonspecific esterase staining14 of the final preparations regularly revealed more than 85% monocytes.

An Integrated Approach for the Valorization of Sea Bass (Dicentrarchus labrax) Side Streams: Evaluation of Contaminants and Development of Antioxidan…

2021

In this study, the presence of As, Hg, Cd, Pb, and mycotoxins in sea bass side streams (muscle, head, viscera, skin, and tailfin) was evaluated as a preliminary step to assess the effect of an innovative extraction technique (Pressurized Liquid Extraction

Influence of yeast strain on ochratoxin A content during fermentation of white and and red must

2006

Staphylococcus aureus alpha-toxin. Production of functionally intact, site-specifically modifiable protein by introduction of cysteine at positions 6…

1993

Staphylococcal alpha-toxin, the prototype of an oligomerizing, pore-forming cytotoxin, is sensitive to biochemical modifications and cannot be labeled with biotin or fluorescein under preservation of its biological activity. In this study, we have used site-directed mutagenesis to introduce cysteine residues at positions 69, 130, and 186. Each mutant was fully and rapidly reactive with several sulfhydryl-specific reagents, indicating superficial location. Coupling of SH-groups with fluorescein-maleimide or biotin-maleimide was tolerated without loss of hemolytic activity at position 130, and the formed hexamers were visible on target cells by fluorescence microscopy and could be detected on…

Variability in the cadherin gene in an Ostrinia nubilalis strain selected for Cry1Ab resistance

2008

Transgenic corn expressing Cry1Ab (a Bacillus thuringiensis toxin) is highly effective in the control of Ostrinia nubilalis. For its toxic action, Cry1Ab has to bind to specific insect midgut proteins. To date, in three Lepidoptera species resistance to a Cry1A toxin has been conferred by mutations in cadherin, a protein of the Lepidoptera midgut membrane. The implication of cadherin in the resistance of an Ostrinia nubilalis colony (Europe-R) selected with Bacillus thuringiensis Cry1Ab protoxin was investigated. Several major mutations in the cadherin (cdh) gene were found, which introduced premature termination codons and/or large deletions (ranging from 1383 to 1701bp). The contribution …

Killer-toxin-resistant kre12 mutants of Saccharomyces cerevisiae: genetic and biochemical evidence for a secondary K1 membrane receptor.

1995

The Saccharomyces cerevisiae killer toxin K1 is a secreted alpha/beta-heterodimeric protein toxin that kills sensitive yeast cells in a receptor-mediated two-stage process. The first step involves toxin binding to beta-1,6-D-glucan-components of the outer yeast cell surface; this step is blocked in yeast mutants bearing nuclear mutations in any of the KRE genes whose products are involved in synthesis and/or assembly of cell wall beta-D-glucans. After binding to the yeast cell wall, the killer toxin is transferred to the cytoplasmic membrane, subsequently leading to cell death by forming lethal ion channels. In an attempt to identify a secondary K1 toxin receptor at the plasma membrane leve…

Report of the IVth Workshop of the Spanish National Network on Mycotoxins and Toxigenic Fungi and Their Decontamination Processes (MICOFOOD), Held in…

2019

Ensiling is a practice commonly employed worldwide to preserve different kinds of crops for long periods of storage with similar nutritional values to the fresh materials. Since silages are one of the major components of the ruminant diet, these materials represent a potential source of mycotoxins as a consequence of the growth of filamentous fungi. The aim of this study was to analyse the presence of aflatoxins and Fusarium mycotoxins in different types of silages (maize, grass, alfalfa, sugar beet pulp, immature corn and ryegrass) collected in dairy farms located in four Spanish regions. Fungal populations, lactic acid bacteria, pH and water activity of the samples were also evaluated. Pe…

Impact of Minimally Invasive Surgery in the Spectrum of Current Achalasia Treatment Options

2011

Minimally invasive Heller myotomy has evolved the “gold standard” procedure for achalasia in the spectrum of current treatment options. The laparoscopic technique has proved superior to the thoracoscopic approach due to improved visualization of the esophagogastric junction. Operative controversies most recently include the length of the myotomy, especially of its fundic part, with respect to the balance between postoperative persistent dysphagia and development of gastroesophageal reflux, as well as the type of the added antireflux procedure. Perioperative mortality should approach 0%, and favorable long-term results can be achieved in > 90%.

Beta-amyloid monomers are neuroprotective

2009

The 42-aa-long β-amyloid protein—Aβ1-42—is thought to play a central role in the pathogenesis of Alzheimer's disease (AD) (Walsh and Selkoe, 2007). Data from AD brain (Shankar et al., 2008), transgenic APP (amyloid precursor protein)-overexpressing mice (Lesné et al., 2006), and neuronal cultures treated with synthetic Aβ peptides (Lambert et al., 1998) indicate that self-association of Aβ1-42monomers into soluble oligomers is required for neurotoxicity. The function of monomeric Aβ1-42is unknown. The evidence that Aβ1-42is present in the brain and CSF of normal individuals suggests that the peptide is physiologically active (Shoji, 2002). Here we show that synthetic Aβ1-42monomers support …