Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Acrylamides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1975

Statistical analysis on toxicity of a nitrofuran derivative, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide.

A food additive, furylfuramide or AF-2, which had been used in Japan since 1965 and structurally is composed of 5-nitro-2-furyl radical and acrylamide, was re-examined mainly on chronic toxicity by statistically reviewing published data. The conclusions are as follows: 1) The maximum safety dosage which shows no demonstrable change in rats must be corrected at least to 1/170 of the value which has been accepted by the Ministry of Health and Welfare of Japan (MHW). 2) The minimum effective dose to bacterial growth in food can not be lowered below the standard usage level with MHW determined, because the inactivation factor in food, decreasing effectivity to 1/20, must be taken into consideration. 3) In view of these two facts, AF-2 is found to be unacceptable as a food additive. 4) Great importance must also be attached to the possibility of mutagenicity and carcinogenicity of AF-2, pointed out recently. Both neurotoxicity and dermatitis observed in tofu (soybean curd) makers are also memtioned.

Acrylamides↗
PubMed2005

Formation of acrylamide in a processed food model system, and examination of inhibitory conditions.

Acrylamide (AAm) is formed from asparagine (Asn) and reducing sugar during cooking of foods at high temperature. We examined the formation of AAm in a model system using a glass fiber filter paper, and looked for suitable conditions for inhibiting AAm formation. In frying, the formation rate was about 10 times that in a moistureless oven. Increase of frying temperature and frying time increased AAm formation when the residual moisture was 5% or less. AAm increased with increasing amount of glucose (Glc) addition up to 1:1 with respect to Asn, but then decreased. On the other hand, in the case of fructose, as the amount added was increased, AAm increased accordingly. The AAm formation rate with respect to Asn increased when valine (Val) was co-present in a Glc and Asn reaction system. Cysteine and lysine inhibited the AAm formation rate. Pathways for the formation of AAm are proposed.

Acrylamide↗
PubMedDate not supplied

[Adaptation of acrylamide producer Rhodococcus rhodochrous M8 to change in ammonium concentration in medium].

The mechanism of adaptation of the acrylamide producing strain Rhodococcus rhodochrous M8 to changes in ammonium concentrations in the medium was studied. An increase in the content of ammonium in the medium changed the activity of glutamine synthetase (GS) (EC 6.3.1.2) and glutamine dehydrogenase (GD) (EC 1.4.1.4), the enzymes of ammonium assimilation, as well as the activities of enzymes responsible for nitrile utilization: nitrile hydratase (EC 4.2.1.84) and amidase (EC 3.5.1.4). This also caused inhibition of activation of GS induced by phosphodiesterase (EC 3.1.4.1). Increases in the activities of nitrile hydratase and amidase and resistance of these enzymes to ammonium were observed in mutant of R. rhodichrous resistant to phosphotricine, an inhibitor of GS. An important role of GS in the mechanism of adaptation is suggested.

Acrylamide↗
PubMed1997

Acrylamide intoxication modifies in vitro responses of peripheral nerve axons to anoxia.

Decreased axolemmal Na+/K(+)-ATPase activity has been considered as a possible mechanism for peripheral nerve axon damage induced by acrylamide (ACR) or 2,5-hexanedione (HD). Reduced activity of this enzyme is also presumed to be the basis of peripheral nerve resistance to ischemia or hypoxia associated with other neuropathies (e.g., diabetes). In the present study, we tested the hypothesis that peripheral nerve of ACR (50 mg/kg/d x 10 d) or HD (400 mg/kg/d x 20 d) exposed rats are resistant to oxygen-limiting conditions as a result of reduced axonal Na+/K(+)-ATPase activity. As an index of resistance, effects of in vitro anoxia on subaxonal concentrations of Na, K and Ca were assessed in isolated segments of tibial nerve from control and neurotoxicant-treated animals. Results show axons from HD rats were not resistant to anoxic challenge; i.e., axons exhibited disrupted elemental composition comparable to anoxic control changes. In contrast, ACR-exposed axons displayed anoxic resistance. Ouabain-exposed tibial axons subjected to anoxic conditions were also resistant, but the corresponding elemental pattern did not resemble that associated with ACR axons. Moreover, ACR axons were capable of maintaining elemental gradients during normoxic exposure which should not be possible if Na+ pump activity is depressed. Considered together, these data are not consistent with a role for diminished Na+/K(+)-ATPase activity in neurotoxicant-induced peripheral axonopathy. We also assessed the ability of ACR- and HD-exposed tibial nerve axons to recover from anoxia. Unlike control fibers which can fully restore normal elemental composition, neurotoxicant-exposed axons were incapable of such restoration. These data suggest the axonal machinery responsible for post-anoxia recovery (e.g., energy metabolism, ion translocation, Ca2+ and free radical buffering) is compromised by ACR or HD intoxication.

Acrylamide↗
PubMed2001

[Severe chronic acrylamide intoxication].

This report of a severe, occupational, long-term acrylamide intoxication with permanent peripheral neuropathy, that chemical toxicity is still a hazard at Danish workplaces.

Acrylamide↗
PubMed1979

Biological effects of some N-substituted (meth)acrylamides.

This paper reports an investigation of the biological effects of monomers of N-substituted (meth)-acrylamides used in the preparation of polymers suitable for medical purposes. By combining tests carried out on cell cultures and on living animals, we found thpheral nervous system. Tests performed on cell cultures can be used as preliminary and supplementary ones in testing the toxicity of substances on living animals.

Acrylamides↗
PubMed1979

Biological tolerance of copolymers of N-substituted (meth)acrylamides in the test organism.

The mechanical properties of hydrolphilic crosslinked polymers of N-substituted (meth)acrylamides may be improved by copolymerization with N-tertbutylacrylamide [1] so that the mechanical properties of resulting copolymers satisfy requirements on polymers used in medicine. Tests of the biological tolerance of the above copolymers have shown that the latter are completely nontoxic with respect to cell cultures and do not cause any reaction or changes in the subcutaneous implantation into a living organism.

Acrylamides↗
PubMed2003

[Neurobehavioral toxicity of acrylamide and IDPN (3,3'-iminodipropionitrile) in rats by 28-day oral administration--problems encountered in collaborative study and a commentary on conducting neurobehavioral testing].

In order to clarify technical problems in evaluating neurotoxicity of chemicals and to solve them, a collaborative study with a common protocol was conducted at 11 domestic safety research laboratories. In the collaborative study, acrylamide and IDPN (3,3'-iminodipropionitrile), which are known neurotoxicants, were used, and the chemicals were orally administered to rats for 28 days. In addition to the clinical observation done routinely, detailed clinical observation, sensory and motor function tests including grip strength and motor activity were performed to evaluate neurobehavioral toxicity with reference to Functional Observational Battery (FOB). In general, neurobehavioral toxicity of the two chemicals was detected in the collaborative study. However, we also encountered technical problems, since neurobehavioral testing was unfamiliar to us. In the present report, we describe the major problems and how to solve them, and briefly explain the neurobehavioral testing procedure.

Acrylamide↗
PubMed2004

[Acrylamide, antiparasitic agents, dioxins and more: how dangerous are contaminants and residues in food?].

Within the European Union, food safety and consumer protection are topics of highest priority. The evaluation of the safety of contaminants and residues in food is usually based on the determination of the acceptable daily intake (ADI), which in turn is the basis for maximum residue levels (MRLs). As this procedure depends on animal testing, a safety factor of 100 is usually applied to provide a margin of safety. This paper discusses the occurrence of relevant contaminants (e.g. dioxins, acrylamide) and residues (e.g. antibiotics, antiparasitic agents) in food and provides a brief assessment of the risks resulting from the consumption of food containing these substances.

Acrylamide↗
PubMed2004

[Synthesis and the drug release properties of poly(acrylamide-co-glycosylallylamide) hydrogels].

Sugar-containing monomer glycosylallylamide (AAG) was synthesized by allyl amine and delta-gluconolactone in dimethylformamide (DMF) solution. The sugar-based hydrogels were prepared by free radical crosslinking copolymerization of AAG and acrylamide (AM). The release properties of Aspirin from xerogels matrices were studied and the release mechanism of Aspirin was further identified by evaluating the n value in Peppas equation. The results indicate that the drug release decreases with the increase of the sugar content of hydrogel.

Acrylamide↗
PubMed2005

Design, synthesis and pharmacological evaluation of some novel 2-(4-nitrophenyl)-3-methylthio-3-(substituted)arylamino acrylamides as potential anti-inflammatory agents.

On the basis of structure based drug design we have designed a series of 2-(4-nitrophenyl)-3-methylthio-3-(substituted)arylamino acrylamides as potential antiinflammatory agents. Good 3D similarity was observed between the designed molecule and rofecoxib (r.m.s.d. 0.161). The effect of opening the central ring and introducing a spacer (-NH-) between one of the aryl rings and the central ring of the basic structure of the COX-2 inhibitors was also studied. The designed molecules were synthesised by thiocarbomylation of the 4-nitro-phenylacetamide with aryl isothiocyanates followed by subsequent methylation of the enethiolate salts. All compounds were screened for their antiinflammatory activity by the carrageenan induced rat paw edema method. Compounds 4 and 6 exhibited potent antiinflammatory activity, which was found to be comparable with the standard drug, rofecoxib. Both the potent molecules were also screened for their ulcerogenic potential in Albino rats. A very low ulcer index was observed with both compounds, although higher than rofecoxib.

Acrylamides↗
PubMedDate not supplied

Reduction of exposure to acrylamide: achievements, potential of optimization, and problems encountered from the perspectives of a Swiss enforcement laboratory.

The most important initiatives taken in Switzerland to reduce exposure of consumers to acrylamide are the separate sale of potatoes low in reducing sugars for roasting and frying, the optimization of the raw material and preparation of french fries, and campaigns to implement suitable preparation methods in the gastronomy and homes. Industry works on improving a range of other products. Although these measures can reduce high exposures by some 80%, they have little effect on the background exposure resulting from coffee, bread, and numerous other products for which no substantial improvement is in sight. At this stage, improvements should be achieved by supporting voluntary activity rather than legal limits. Committed and consistent risk communication is key, and the support of improvements presupposes innovative approaches.

Acrylamide↗
PubMedDate not supplied

Results from two interlaboratory comparison tests organized in Germany and at the EU level for analysis of acrylamide in food.

After the publication of high levels of acrylamide (AA) in food, many research activities started all over the world in order to determine the occurrence and the concentration of this substance in various types of food. As no validated methods were available at that time, interlaboratory studies on the determination of AA in food were of the highest priority. Under the boundary conditions of applying well-established evaluation schemes, the results of 2 studies conducted by the Federal Institute for Risk Assessment (BfR) in Germany and by the European Commission's Directorate General Joint Research Center (JRC) exhibited an overall acceptable performance of the participants in these studies. Nevertheless, many laboratories showed problems in determining AA in food with a complex matrix such as cocoa. The results of analysis also showed a broader variation of AA for samples with low AA concentrations and indicated a bias of the results obtained by gas chromatography-mass spectrometry without derivatization. Improvements of the performance of some laboratories appeared to be necessary.

Acrylamide↗
PubMed2004

[Studies on photoluminescence characteristics of curcumin in acrylamide polymer].

A photoluminescence polymer was prepared using acrylamide as a monomer, a large excess of ethyleneglycol dimethacrylate as the cross-linking agent, and curcumin as a fluorescence additive. The polymer was ground into powder and screened in order to get even powder, whose diameter was from 40 to 75 microm. The emission spectra of curcumin in solid powder polymer show a strong blue shift compared with that of curcumin in C2H5OH solution. Meanwhile, rhodamine 6G, tetraiodofluorescein and phloxin have the same phenomenon of blue shift. Based on these facts, we speculate that the mechanism is probably singlemolecular luminescence because of the limit effect in three dimension space of the polymer. The molecule fluorescence peak was also depending on its environment because the surrounding electron field affected the molecule luminescence in polymer.

Acrylamide↗
PubMedDate not supplied

[Gel-producing properties of exopolysaccharide acrylamide in composition with agar-agar].

A possibility to use a new polymer--exopolysaccharide acrylamide (EPAA)--for partial substitution of agar-agar in solid nutrient media in microbiology has been studied. It has been established than the EPAA in concentration 6.0-12.0 g/l with agar in concentration 10.0 g/l produce gel which is so strong as agar in concentration 15.0-20.0 g/l. Quality of gels produced depends an the method of EPAA mixing with agar. It has been shown that usage of EPAA in nutrient media does not affect growth, colony and cell morphology and biochemical properties of microorganisms. The use of EPAA to prepare nutrient media permits us to reduce expenditures for agar.

Acrylamide↗
PubMed2005

[Mutational spectra in the tk gene of mouse lymphoma cells induced by acrylamide].

OBJECTIVE: To investigate the mechanism of acrylamide (AA)-induced mutational spectra in the tk gene of mouse lymphoma cells. METHODS: L5178Y3.2.7c-tk(+/-) cells were treated with AA at different concentrations. Mutational spectra of tk locus were analyzed by the mouse lymphoma assay (microtiter procedure), and frequency of loss of heterozygosity (LOH) analysis with allele special PCR. Subsequently determined the DNA sequence of negative LOH's colonies induced by AA. RESULTS: The LOH of mutants derived from AA induction was 78.8%, and showed a good dose-response relationship in large colonies. The occurrence of LOH of large colonies at lower doses (150 microg/ml and 300 microg/ml) were 25.0% and 33.3% respectively which were significantly different from those of control (66.7%), and at higher doses (600 microg/ml and 750 microg/ml) were 77.8% and 85.7%. By Sequence analysis showed that AA-induced point mutations were mainly base substitutions, and most of them were T:G-->G:T transversions. CONCLUSION: Functional tk allele gene loss is major mutational event in both spontaneous and induced tk mutants. And point mutations were base substitution.

Acrylamide↗
PubMedDate not supplied

Evaluation of results of an interlaboratory comparison test on determination of acrylamide in crispbread samples.

The European Commission's Directorate General Joint Research Centre has organized several proficiency tests on the determination of acrylamide (AA) in food. This paper presents the results and outcome of a proficiency test that focused on the determination of AA in crispbread samples. One of the goals was the identification of the influence of different parameters such as analyte extraction or instrument calibration on the analytical results. A set of samples, containing 3 different crispbread samples as well as extracts of one crispbread sample and AA standard solutions, was shipped to each participant. A total of 42 European laboratories reported analytical results that were evaluated by applying internationally accepted protocols and procedures. The study found that, for each sample, the results of 4-8 laboratories were outside the range formed by the target value plus or minus the 2-fold of the target standard deviation; thus, they did not perform satisfactorily. In transferring this knowledge to the data of monitoring databases of AA in food, care must be taken that data are quality controlled, as it is likely that some of them may be biased.

Acrylamide↗
PubMed2006

[Analytical methods for the determination of acrylamide in food products].

In April 2002, researchers in Swedish reported that they had found high level acrylamide (AA) in carbohydrate-rich foods during cooking at high temperature, which shocked scientists worldwide. Because AA has been identified as being carcinogenic, neurotoxic and genotoxic, researchers had developed methods to determinate the AA level in kinds of foods. The review is based on the achievement and progress of AA analysis in foods in recent years which contains the samples' extraction, clean-up, derivatization and determination by chromatography coupled with mass spectrometer.

Acrylamide↗