Search results for "Cholin"
showing 10 items of 1261 documents
Cardiovascular control and time domain granger causality: Insights from selective autonomic blockade
2013
We studied causal relations among heart period (HP), systolic arterial pressure (SAP) and respiration (R) according to the definition of Granger causality in the time domain. Autonomic pharmacological challenges were used to alter the complexity of cardiovascular control. Atropine (AT), propranolol and clonidine (CL) were administered to block muscarinic receptors, β-adrenergic receptors and centrally sympathetic outflow, respectively. We found that: (i) at baseline, HP and SAP interacted in a closed loop with a dominant causal direction from HP to SAP; (ii) pharmacological blockades did not alter the bidirectional closed-loop interactions between HP and SAP, but AT reduced the dominance of…
Cholinesterase variants: rapid characterisation by PCR/SSCP and evidence for molecular homogeneity.
1995
We have applied the technique of PCR-SSCP (polymerase chain reaction-single stranded conformation polymorphism) to characterise the molecular basis of cholinesterase deficiency and variants in a Jordanian family. PCR-SSCP proved to be a quick and sensitive method of screening cholinesterase variants in a clinical setting. An AG insertion at position 351 was found to cause a silent allele, for which the parents were heterozygous and three children homozygous. In addition, the father and two sons were heterozygous for an A to G transition at position 209, known to cause the dibucaine resistant variant. No linkage to the K variant was found, which has been reported previously in white populati…
Cellular distribution of nicotinic acetylcholine receptor subunit mRNAs in the human cerebral cortex as revealed by non-isotopic in situ hybridizatio…
1994
The pharmacology of telencephalic nicotinic acetylcholine receptors (nAChRs) has become an important issue in recent years. While in the human brain a direct pharmacological assessment is difficult to achieve the visualization of nAChRs has been enabled by histochemical techniques providing an ever increasing and improving resolution. Receptor autoradiography was used to visualize binding sites on the level of cortical layers whereas immunohistochemistry has allowed for the cell type-specific and ultrastructural localization of receptor protein. Further investigations have to elucidate the cellular sites of NAChR biosynthesis by visualizing subunit-specific transcripts. Using autopsy sample…
Determination of acetylcholine, nitrostigmine and acetylcholinesterase activity in four patients with severe nitrostigmine (E 605 forte) intoxication.
1974
Concentrations of acetylcholine and nitrostigmine as well as acetylcholinesterase activity were determined in 4 patients with severe nitrostigmine intoxication. In the acute phase of the intoxication, acetylcholine levels up to 36 and 55 ng/ml were found in blood plasma and cerebrospinal fluid, respectively. At the same time no activity of acetylcholinesterase in plasma and erythrocytes was detected. Acetylcholinesterase activity gradually recovered at the end of the second week. In the first 3 days after the ingestion plasma nitrostigmine concentrations ranged from 409 to 86 ng/ml. At the end of the third week nitrostigmine was still found in a concentration of about 1 ng/ml plasma. Redist…
External and internal exposure of wine growers spraying methyl parathion.
2005
Organophosphates, used in agriculture, are readily absorbed through the skin. We investigated the relationship between dermal and inhalative methyl parathion exposure and the plasma levels. Twenty-three healthy wine growers sprayed the insecticide for 50 min. Fluorescent brilliant sulfoflavin was added to the spraying fluids and filter papers were fixed on the subjects. The filter papers were used to evaluate the amount of brilliant sulfoflavine on the unprotected skin fluorometrically. Inhalative exposure was measured with personal air sampler. Plasma concentrations of methyl parathion and its metabolite methyl paraoxon were determined with gas chromatography. Cholinesterase activity in se…
Evidence against preserved syntactic comprehension in healthy aging.
2018
We investigated age-related differences in syntactic comprehension in young and older adults. Most previous research found no evidence of age-related decline in syntactic processing. We investigated elementary syntactic comprehension of minimal sentences (e.g., I cook), minimizing the influence of working memory. We also investigated the contribution of semantic processing by comparing sentences containing real verbs (e.g., I cook) versus pseudoverbs (e.g., I spuff). We measured the speed and accuracy of detecting syntactic agreement errors (e.g., I cooks, I spuffs). We found that older adults were slower and less accurate than younger adults in detecting syntactic agreement errors for both…
Illusory inferences from a disjunction of conditionals: a new mental models account
2000
(Johnson-Laird, P.N., & Savary, F. (1999, Illusory inferences: a novel class of erroneous deductions. Cognition, 71, 191-229.) have recently presented a mental models account, based on the so-called principle of truth, for the occurrence of inferences that are compelling but invalid. This article presents an alternative account of the illusory inferences resulting from a disjunction of conditionals. In accordance with our modified theory of mental models of the conditional, we show that the way individuals represent conditionals leads them to misinterpret the locus of the disjunction and prevents them from drawing conclusions from a false conditional, thus accounting for the compelling char…
Associative and semantic priming effects occur at very short stimulus-onset asynchronies in lexical decision and naming
1997
Abstract Prior research has found significant associative/semantic priming effects at very short stimulus-onset asynchronies (SOAs) in experimental tasks such as lexical decision, but not in naming tasks (however, see Lukatela and Turvey, 1994 ). In this paper, the time course of associative priming effects was analyzed at several very short SOAs (33, 50, and 67 ms), using the masked priming paradigm ( Forster and Davis, 1984 ), both in lexical decision (Experiment 1) and naming (Experiment 2). The results show small—but significant—associative priming effects in both tasks. Additionally, using the masked priming procedure at the 67 ms SOA, Experiments 3 and 4, shows facilitatory priming ef…
The formation of structurally relevant units in artificial grammar learning
2002
A total of 78 adult participants were asked to read a sample of strings generated by a finite state grammar and, immediately after reading each string, to mark the natural segmentation positions with a slash bar. They repeated the same task after a phase of familiarization with the material, which consisted, depending on the group involved, of learning items by rote, performing a short term matching task, or searching for the rules of the grammar. Participants formed the same number of cognitive units before and after the training phase, thus indicating that they did not tend to form increasingly large units. However, the number of different units reliably decreased, whatever the task that…
Intoxication with a tropenol ester.
2012
BACKGROUND While the effects of medicinal products are investigated in depth before approval, often very little is known about the intermediates occurring during synthesis. The pharmacological properties of these intermediates can differ substantially from those of the end product. AIMS To describe a work accident involving intoxication with such an intermediate, tropenol ester. CASE REPORT A healthy 40-year-old chemical-technical operative erroneously used a scrubbing brush that had just been used to clear up tropenol ester, contaminating his work clothes. Presumably, contact was made with his skin when removing his work clothes later. Shortly thereafter, he developed signs of anticholiner…