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  • Author or Editor: P. Nagy x
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Background: Monitoring the retinal nerve fibre layer thickness (RNFLT) is essential in the diagnosis and treatment of glaucoma. In a previous study we found that a decrease of the polarimetric RNFLT observed in the early period after laser-assisted in situ keratomileusis (LASIK) disappears or tends to disappear by the third post-LASIK month. Purpose: To study the stability of the “recovered” polarimetric retardation values between the third and twelfth month after LASIK. Methods: Scanning laser polarimetry (SLP) with the classic GDx Nerve Fiber Analyzer was performed on 13 consecutive healthy subjects with no eye disease who underwent LASIK for ametropia correction. Measurements were performed preoperatively, then at 3 and 12 months postoperatively. Results: Inferior, temporal and nasal average thickness as well as ellipse average thickness and average thickness showed no difference among the three time points (ANOVA, p ? 0.05). Superior average thickness was significantly smaller both at three months (Sheffe test, p = 0.008) and 12 months (p = 0.006) than before LASIK. However, no difference was seen between the values measured at three months and at 12 months after LASIK (p = 0.997). A statistically significant interaction between treatment type (myopic or hyperopic correction) and the change of retardation was found for the superior average thickness (two-way ANOVA, p = 0.016). In this quadrant the RNFLT values of the myopic eyes decreased between the baseline and the month 3 measurements but became stable after that; the retardation of the hyperopic eyes remained unchanged throughout. Conclusion: RNFLT measured with the classic GDx device after LASIK shows transient changes probably due to the LASIK-induced alteration of the polarization and the healing process. The polarimetric RNFLT values, however, become stable by the third post-LASIK month, and show no further change until the end of the first year after LASIK. Baseline SLP measurements for long-term glaucoma follow-up can be obtained from the third post-LASIK month onwards.

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Authors: J. Bognár, Gy. Sonnevend, J. Szabados and P. Nagy
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Abstract  

Various cation-exchanged montmorillonites (Li+, Na+, Ba2+, Mg2+, Ca2+, Mn2+, Co2+, Cu2+, Ag+, Cd2+, Hg2+, Al3+, Pb2+ and NH4+) were prepared from calcium montmorillonite and their properties were studied by means of X-ray diffraction and thermal analysis. The two methods give information on the cation exchange in the interlayer space only. X-ray diffraction studies at room temperature are mainly suitable for estimation of the exchange of cations of different valencies. At 500C, when the structure is completely collapsed, the d value of montmorillonite depends on the non-hydrated ionic radius of the interlayer cation, but the measurement interval is limited for fine interpretation. The thermoanalytical method is suitable for a better distinction of different exchangeable cations of higher hydration energy on the basis of the DTG or DDTG curve.

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Few researches address the compatibility of organic mulching and entomopathogenic (EPN) and slug-parasitic (SPN) nematodes, although organic mulching may provide favourable conditions for these beneficial organisms. Our aim was to examine the effect of different concentrations (0.1, 0.5, 1 and 5%) of aqueous extracts of green waste compost, the dry leaf litters of the common walnut (Juglans regia) and Norway maple (Acer platanoides) on EPN (Heterorhabditis bacteriophora, Steinernema carpocapsae, Steinernema feltiae, Steinernema kraussei) and SPN (Phasmarhabditis hermaphrodita) species. Experiments were set up in 96-well, flat-bottom microplates. After a 24-hour exposure time, the number of dead animals was counted under a transmission microscope. Green waste compost extracts caused quite low or no mortality in case of all examined species. Mortality caused by the 5% Norway maple leaf litter extract was moderate (34.6%) in the case of S. carpocapsae juveniles, while 100% of juveniles of other species died. The highest (5%) concentration of the common walnut leaf litter extract caused 100% mortality in all species. As a conclusion, green waste compost mulch seems to be more compatible with EPN and SPN species than common walnut or Norway maple leaf litter mulch.

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Long-term effects of the elevated atmospheric CO 2 on biosphere have been in focus of research since the last few decades. In this experiment undisturbed soil monoliths of loess grassland were exposed to an elevated CO 2 environment (two-times the ambient CO 2 level) for a period of six years with the aid of the open top chamber method. Control without a chamber and CO 2 elevation was applied as well. Elevated CO 2 level had very little impact on soil food web. It did not influence either root and microbial biomass or microbial and nematode community structure. The only significant response was that density of the bacterial feeder genus Heterocephalobus increased in the chamber with elevated CO 2 concentration. Application of the open top chambers initiated more changes on nematodes than the elevated CO 2 level. Open top chamber (OTC) method decreased nematode density (total and plant feeder as well) to less than half of the original level. Negative effect was found on the genus level in the case of fungal feeder Aphelenchoides , plant feeder Helicotylenchus and Paratylenchus . It is very likely that the significantly lower belowground root biomass and partly its decreased quality reflected by the increased C/N ratio are the main responsible factors for the lower density of the plant feeder nematodes in the plots of chambers. According to diversity profiles, MI and MI(2–5) parameters, nematode communities in the open top chambers (both on ambient and elevated CO 2 level) seem to be more structured than those under normal circumstances six years after start of the experiment.

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Authors: L. Mesarčová, S. Marcinčák, J. Nagy, P. Popelka, M. Bača, P. Jevinová and D. Marcinčáková

Frozen fillets of Atlantic herrings (Clupea harengus) were used to evaluate the effect of glaze with or without addition of selected herbal extracts on lipid oxidation and sensory properties during 8 months of freezing storage under −14 °C. Fillets were divided into four groups: control non-glazed group, glazed group without addition of herbal extracts, and glazed groups with addition of hawthorn (Crataegus oxyacantha L.) extract (0.3%) and agrimony (Agrimonia eupatoria L.) extract (0.3%). The antioxidant activity and total phenolic content in hawthorn and agrimony extracts, and their effect on lipid deterioration expressed as thiobarbituric acid reactive substances were measured. The results showed that the herbal extracts of hawthorn and agrimony are effective antioxidants and good sources of total phenols. Significant influence of herbal extracts added into glaze on the extent of lipid oxidation changes has been obvious within 4 months storage of herring fillets under freezing conditions. Finally, positive influence of glaze and herbal extracts on organoleptic characteristics of fish fillets was found.

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Authors: Á. Horváth, P. Sántha, V. Horváth, Nóra Török, I. Nagy, G. Jancsó, Cs. Vágvölgyi and F. Somogyvári

A new, rapid method is described which permits the genotyping of genetically modified animals from a microlitre volume of whole blood samples via one step polymerase chain reaction amplification. The major advantage of the presented method is the exclusion of a DNA preparation step, which significantly reduces the time expenditure and work load of the genetic testing. Pilot studies indicate, that this method is efficient and applicable also on tissue biopsies and larger amount of blood providing a rapid and reliable new technique over conventional genotyping approaches.

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The pharmacokinetics and the influence of food on the kinetic profile and bioavailability of doxycycline was studied after a single intravenous (i.v.) and oral dose of 10.0 mg/kg body weight in 7-week-old broiler chickens. Following i.v. administration the drug was rapidly distributed in the body with a distribution half-life of 0.21 ± 0.01 h. The elimination half-life of 6.78 ± 0.06 h was relatively long and resulted from both a low total body clearance of 0.139 ± 0.007 L/h·kg and a large volume of distribution of 1.36 ± 0.06 L/kg. After oral administration to fasted chickens, the absorption of doxycycline was quite fast and substantial as shown by the absorption half-life of 0.39 ± 0.03 h, the maximal plasma concentration of 4.47 ± 0.16 —g/mL and the time to reach the Cmax of 1.73 ± 0.06 h. The distribution and the final elimination of the drug were slower than after i.v. administration. The absolute bioavailability was 73.4 ± 2.5%. The presence of food in the intestinal tract reduced and extended the absorption (t1/2a = 1.23 ± 0.21 h; Cmax = 3.07 ± 0.23 µg/mL; tmax = 3.34 ± 0.21 h). The absolute bioavailability was reduced to 61.1% ± 4.4%.

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Authors: Judit Juhász, P. Nagy, Margit Kulcsár, G. Szigeti, J. Reiczigel and Gy. Huszenicza

The effect of 10-day zearalenone administration starting 10 days after ovulation was studied in 6 cycling trotter mares in the summer period. After an entire oestrous cycle (Cycle 1), mares were given 7 mg purified zearalenone per os daily (1 mg/ml in ethyl alcohol) beginning on Day 10 of Cycle 2. Toxin exposure was continued until the subsequent ovulation. Luteal function and follicular activity were monitored daily by rectal palpation, ultrasonography and blood sampling for progesterone. During toxin exposure, all animals were in good physical condition. The toxin had no effect on the length of the interovulatory intervals, luteal and follicular phases. It did not influence significantly the plasma progesterone profiles (logistic curve parameters A1 to A6), the follicular activity (growth rate, maximum size of the ovulatory follicles, maximum number and the time of first increase in the number of large follicles) and the uterine oedema. It is concluded that in cyclic mares the methods used in this study could not detect any adverse effect of zearalenone (administered at a low dose similar to natural exposure) on reproduction.

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Authors: Sz. Nagy, A. Kovács, T. Zubor, Z. Zomborszky, J. Tóth and P. Horn

A simultaneous live/dead and acrosome staining, originally described for domestic mammals, was successfully applied on red deer (Cervus elaphus) and fallow deer (Dama dama) spermatozoa collected from the cauda epididymidis and vas deferens of shot stags. The staining is simple enough for routine application. Seven classes of spermatozoa were distinguished in the smears of frozen/thawed semen samples. Morphology, including cytoplasmic droplets, was evaluated as well. Percentage of live cells with intact acrosomes and with no other morphological aberrations might be a practical index of semen quality.

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