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  • Author or Editor: P. Nagy x
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Mixed population of different biotypes of C. arvense can be found in the cereal fields in Eastern Europe. Three biotypes were identified taxonomically: var. arvense; var. horridum, and var. vestitum. Out of the three identified biotypes, only var. arvense showed more sensitivity to chlorsulfuron, while the other two biotypes were less sensitive. There was no difference in the germination behaviour of the biotypes, thus all varieties can be present on the field at the same time. The less sensitive biotypes have a thicker cuticle and less stoma on the leaves than the more sensitive one. There is no significant difference between sensitive and resistant biotypes in absorption and translocation of the 14C chlorsulfuron and florasulam. Sensitivity of the ALS-enzyme was significantly reduced in the resistant biotypes, although the enzyme still functions. Since that cereal fields in Eastern Europe are infested with C. arvense biotypes with different susceptibilities to chlorsulfuron, it is important to consider resistance management when selecting herbicides. Selection pressure for ALS resistance can be reduced by including other herbicides with an alternative mode of action; as tank mixes, premixes, or separate applications.

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The anaphase promoting complex or cyclosome (APC/C) is a large protein complex with an ubiquitin ligase activity which specifically targets mitotic regulatory proteins for proteasomal degradation. The APC/C contains at least 11 subunits, most of which are evolutionarily conserved from yeasts to humans. We have isolated and characterized mutant alleles of the gene that codes for the APC10/Doc1 subunit of the Drosophila APC/C. Loss of function APC10/Doc1 mutants have rudimentary imaginal discs and arrest their development as prepupae. Larval neuroblasts from these mutants show gross mitotic defects including high mitotic index, chromosome overcondensation, metaphase-like arrest and frequent aneuploid and polyploid cells. Mitotically arrested cells accumulate one of the main substrates of APC/C, cyclin B, most likely due to disabled ubiquitination activity. Our results suggest that the Apc10/Doc1 subunit has an essential role in establishing E3 ubiquitin ligase activity of APC/C in Drosophila .

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An amperometric biosensor for the detection of organophosphorus and carbamate type pesticides was developed. Acetylcholinesterase enzyme (electric eel) was immobilized in a thin-layer enzyme cell, and acetylthiocholine chloride (AcTCh) was used as substrate. Amperometric detection with glassy carbon electrode was performed in a stopped-flow FIA system. The inhibition effect of dichlorvos (DDVP), carbofuran, methomyl, and pirimicarb were examined: the linear measuring ranges were 0.001–0.1 μmol l−1, 0.001–0.1 μmol l−1, 0.2-1 μmol l−1, and 0.1–10 μmol l−1, respectively. Soil extract and apple juice were measured with spiking method. It was concluded that the biosensor can be used for screening pesticide residues in food and environmental samples.

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The clinical significance of the oral candidiasis (either as independent disorder, or as a part of another disease) is increasing with time. The diagnosis and local treatment of the oral candidiasis may not be satisfactory, this disorder cannot be eliminated without the correct diagnosis and management of the underlying disease. At the same time, some disorders, such as Candida induced leukoplakia, may significantly enhance tumor development. Fungal infection of the mouth is often the initial sign of several immunodeficiency diseases. It is, therefore, very important to clarify the background of a fungal infection, since this may be critical regarding the prognosis.

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Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is one of the most important pests of greenhouse pepper in Hungary. It has a hidden lifestyle, a short generation interval and a high reproductive rate. Due to these characteristics it is difficult to obtain an effective, environment-friendly and harmless control of the pest. Previous studies have shown that under caged plant conditions, the common crab spider, Xysticus kochi (Thorell) (Araneae: Thomisidae) is effective against western flower thrips. In this study, we examined some of the technological questions of the use of spider larvae.We investigated the necessary amount and number of applications of spider larvae under caged plant conditions. The efficiency of spiders at the whole greenhouse level was also studied. While the ratio of damaged surface of peppers treated with X . kochi was significantly lower than that of non-treated plants, increasing the amount of spider larvae did not improve the effectiveness of thrips control. Although whole greenhouse experiences showed a similar, significant decrease in the rate of damaged surface in the case of peppers treated with spider larvae, when compared to untreated control; the efficiency of spiders remained below the level of economic acceptance.

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Authors: M. Nagy-Gasztonyi, Á. Kardos-Neumann and P. Á. Biacs

Blanching of vegetables before freezing has some advantages as well as a number of disadvantages. Process optimization involves measuring the rate of enzyme destruction, such that the blanching time is just long enough to destroy the indicator enzyme. Eventually, peroxidases were almost universally the enzymes of choice, as they are usually the most heat-stable enzymes found in vegetables and fruits, so by the time they are inactivated no other enzymes or micro-organisms remain. But there is no evidence that peroxidases are involved in deteriorative reactions in the food. The aim of this work was to improve blanching technology in Hungarian frozen food industry with special emphasis on broccoli treatment. Instead of peroxidases, lipoxygenases were chosen to determine the adequate blanching parameters. Usually, lipoxygenases accompany lipases, so lipase activity is measured, too. On the basis of model blanching experiments, the conclusion is that lipoxygenase could be used as indicator enzyme. Being less heat stable than peroxidase, this enzyme requires shorter heat treatment, hence its inactivation should result in minimum quality deterioration and economic loss.

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The concentration (in mg kg–1 fresh weight) of two main hydroxamates, 2,4-dihydroxy- 7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA), and their temporal changes were simultaneously investigated using HPLC analysis in the leaves and roots of five Pioneer® maize (Zea mays L.) hybrids to select hybrids with higher hydroxamate contents. Although significant differences were found among hybrids in leaves, youngest leaves and roots, none of them showed unambiguously higher hydroxamate contents. However, the age of the organs and the plants significantly affected hydroxamate content. DIMBOA content of leaves decreased with increasing organ and plant age. DIBOA content varied among the hybrids, but generally decreased in the initial phase and then increased. In the roots, DIMBOA content decreased during the 21-day study and although DIBOA content did not show a clear temporal tendency, differences among hybrids were detected. According to current results, hydroxamate content temporally decreases in hybridspecific patterns, which should be considered when establishing a proper sampling time frame.

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The activity of the transient receptor potential vanilloid type 1 ion channel (TRPV1) that is expressed by the great majority of polymodal nociceptors is pivotal for the development of inflammatory heat hyperalgesia. The responsiveness of TRPV1 is regulated by a series of intracellular signalling molecules including the cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA); increased or decreased PKA activity results in TRPV1 sensitisation or desensitisation, respectively. Activation of the cannabinoid 1 (CB1) receptor that is expressed by the majority of the TRPV1-expressing primary sensory neurons reduces PKA activity. Therefore, here we studied whether activation of the CB1 receptor resulted in reduced TRPV1-mediated responses in cultured rat primary sensory neurons. We found that TRPV1-mediated whole-cell currents were significantly reduced respectively, by 50% and 25% by 10 nM and 30 nM of the endogenous CB1 receptor agonist, anandamide. The PKA inhibitor, H89 (10 μM) also had a significant inhibitory effect on TRPV1-mediated currents (∼70%). These findings suggest that activation of the CB1 receptor can reduce the activity of TRPV1 in primary sensory neurons, and that this inhibitory effect could be mediated through the reduction of PKA-mediated phosphorylation of TRPV1

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