Authors:A. Raymond, W. Müller, R. Gens, M. Gili, A. Morales, and A. Yates
Beginning in 1991 (and continuing until 1995) a research program has been undertaken involving the participation of six Western European countries, focusing on the following main objectives: (i) comparison of operational analytical methods for long-lived radionuclides and application to real waste samples; (ii) improvement of existing procedures and/or development of some alternative analytical methods; (iii) computation of correlation factors between long-lived radionuclides and easily-measured key radionuclides, through the analysis of some of the main waste streams from the participants' countries. Some preliminary and significant results that have been obtained in the framework of this project are presented and discussed.
Authors:D. Varga, T. Müller, A. Specziár, H. Fébel, Cs. Hancz, Gy. Bázár, B. Urbányi, and A. Szabó
Fatty acid (FA) composition of the fillet and the intestinal content of dwarf common carp (Cyprinus carpio carpio) living in Lake Hévíz was determined in wintertime collected samples and results were compared to widespread literature data on carp. Fillet FA profile of the thermally adapted (28 °C) Hévíz dwarf carps differed from profiles originated from divergent culture and feeding conditions in the overall level of saturation. Fillet myristic acid proportions largely exceeded all literature data in spite of poor dietary supply. Fillet fatty acid results indicate the effects of thermal adaptation (high saturation level) and the correlative effects of feed components rich in omega-3 fatty acids, with special respect to docosahexaenoic acid. With the application of discriminant factor analysis the Hévíz sample was accurately differentiated from the literature data on carp fillet fatty acid profile, mostly based on C14:0, C18:1 n9, C18:2 n6, C20:1 n9 and C20:4 n6 FAs. In summary, fillet FA profile suggested thermal adaptation, location specificity and the ingestion of algal and bacterial material.
Authors:M. Trenovszki, V. Lebovics, T. Müller, T. Szabó, Á. Hegyi, B. Urbányi, L. Horváth, and A. Lugasi
The aim of present study was to survey the fatty acid composition and fat content in common carp (Cyprinus carpio L.) fillet captured in five different fish farms located in Hungary. Lipid peroxidation characteristics (conjugated dienes and malondialdehyde levels) were also determined in fish muscle. Data on fatty acid composition of common carp has shown that different methods of rearing and feeding cause significant differences in the proportions of n-6 and n-3 polyunsaturated fatty acids of this fish species. According to present results, it seems that the feeding practice of the last month before capture has determined the fatty acid profile of fillet, therefore the technology of carp nutrition should be divided into two main periods: first a growth and weight gain period; and a second one when the nutritional quality of the fillet composition can be improved.
Authors:M. Arnal, V. Balsamo, G. Ronca, A. Sánchez, A. Müller, E. Cañizales, and C. Urbina de Navarro
A new technique to thermally fractionate polymers using DSC has been recently developed in our laboratory. The applications of the novel successive self-nucleation and annealing (SSA) technique to characterize polyolefins with very dissimilar molecular structures are presented as well as the optimum conditions to thermally fractionate any suitable polymer sample with SSA. For ethylene/-olefin copolymers, the SSA technique can give information on the distribution of short chain branching and lamellar thickness. In the case of functionalized polyolefins, detailed examinations of SSA results can help to establish possible insertion sites of grafted molecules. The application of the technique to characterize crosslinked polyethylene and crystallizable blocks within ABC triblock copolymers is also presented.
Authors:G. Szabó, T. Müller, M. Bercsényi, B. Urbányi, B. Kucska, and Á. Horváth
Experiments were carried out on the sperm cryopreservation of artificially induced eels. The effects of several extenders and two cryoprotectants on the motility of spermatozoa were investigated. The highest post-thaw motility was observed with the combination of Tanaka's extender and DMSO as cryoprotectant. Further dilution after thawing resulted in complete loss of motility in samples frozen in presence of DMSO while sperm frozen with methanol as cryoprotectant retained its motility after further dilution.
Authors:A. Vos, T. Müller, P. Schuster, T. Selhorst, and U. Wenzel
The objective of the study was to examine possible maternally transferred antibodies (maAb) against rabies in raccoon dogs. Ten cubs born from a rabiesimmune animal were bled on days 31, 36, 43, 50, 57 and 64 post partum. The geometric mean titres of the cubs were 1.19, 1.18, 0.45, 0.25, 0.25 and 0.16 IU/ml, respectively. Up to 36 days post partum maAb were detected in all cubs at levels ≥ 0.5 IU/ml and at day 56 post partum all animals had maAb levels < 0.5 IU/ml. Based on the results of this study, it is suggested that vaccine baits should not be distributed before July if the vaccination campaign is aimed at immunizing young raccoon dogs as well.
Authors:Z. Bokor, T. Müller, M. Bercsényi, L. Horváth, B. Urbányi, and Á. Horváth
Experiments were carried out on sperm cryopreservation of two European percid fish species, the pikeperch
and the Volga pikeperch
. Two experiments were conducted on pikeperch sperm. In the first, the effects of three extenders (Glucose, KCl, Sucrose) and two cryoprotectants (dimethyl-sulfoxide: DMSO, methanol: MeOH) were tested on motility and fertilization. In the second, the effects of two dilution ratios (1: 1, 1: 9) and two cryoprotectants (DMSO, MeOH) on hatching were investigated. In the experiment on Volga pikeperch the suitability of using cryopreservation for fertilization was investigated. In the first experiment on pikeperch the highest post-thaw motility (28 ± 21%) and fertilization rate (43 ± 12%) was found with DMSO as cryoprotectant in combination with Glucose extender. In the second, the highest hatch rate (41 ± 22%) was observed with MeOH as cryoprotectant and 1: 1 sperm dilution ratio, however no significant difference was found among the results. In the experiment on Volga pikeperch hatch rates with cryopreserved sperm (60 ± 2%) did not significantly differ from the control (60 ± 6%). Contamination of sperm with urine seems to be a key problem in the success of sperm cryopreservation of these species.
Authors:Andreja Urbanek-Krajnc, B. Zechmann, G. Zellnig, A. Wonisch, and Maria Müller
Thiols are known to play crucial roles in plant defense responses, e.g. against pathogens. In the present study, the efficiency of these molecules was evaluated in regenerated
Greb. plants in response to compatible
Zucchini yellow mosaic virus
infection. Thiol contents were modulated by applying the cysteine precursor L-2-oxothiazolidine-4-carboxylic acid (OTC) to callus cells. Cytological and biochemical methods were used for determination of glutathione within callus cells and leaves of plants regenerated via somatic embryogenesis. Reduced glutathione levels (GSH) significantly increased in callus cells one week after 1.0 mM OTC treatment by about 56% and resulted in enhanced GSH levels throughout the investigation period of 13 weeks. Three weeks after ZYMV infection untreated plants regenerated from callus culture exhibited stunted growth forms, yellowing, mosaic and blistering on the leaves whereas 68% of 1.0 mM OTC pretreated regenerated plants were characterized by a complete absence of symptoms. Treatment with OTC stimulated the synthesis, conversion and translocation of thiols during advanced ZYMV infection. Compared to untreated infected leaves, a graduate increase in cysteine (cys) and γ-glutamyl-cysteine (γ-glucys) contents was measured in 0.5 mM and 1.0 mM OTC treated older leaves, whereas total glutathione (tGSH) decreased significantly after infection. In OTC treated younger leaves cys and tGSH concentrations remained at control levels and were unaffected by ZYMV. In contrast, OTC treatment caused a dramatic induction of γ-glucys, up to 191% in younger infected leaves. The results show that altered levels of thiols by OTC were accompanied by enhanced tolerance against ZYMV, suppression of ZYMV induced symptoms as well as delayed symptom development.
Authors:J. Harrison, S. Krishnan, C. Muller, A. Strauss, S. Mukherjee, and W. Sturtridge
The accuracy of dual energy X-ray absorptiometry (DEXA) for measurement of bone mass carried out by quantitative digital radiography (Hologic Inc.) was compared to results with neutron activation analysis (NAA) on 106 subjects. The accuracy with DEXA was further investigated by measurements on aluminium samples of known composition. DEXA measured 4 lumbar vertebrae by spine scan. The central third of the skeleton also was measured by whole body scan to obtain data on the same large part of the skeleton as measured by NAA. Results suggested that DEXA spine scans were more reliable than whole body scans. In addition, the measurement of total mineral content (BMC) was more reliable than the normalization of BMC to bone surface area (BMC/Area) or bone mineral density (BDM). Since the proportion of bone below detection would increase with development of osteoporosis, with osteoporosis the BMC would be increasingly underestimated, but to only a small extent, while the BMD would be more significantly overestimated.
Authors:T. Müller, T. Molnár, A. Szabó, E. Yamaha, Éva Járási, M. Bercsényi, A. Specziár, B. Urbányi, and R. Romvári
The present study aimed in vivo tracking of maturation of male eel by computed tomography (CT). Additionally, individually monitored testes sizes were correlated with the conventionally used external maturity indicators (i.e. eye and nose indexes) in order to test and improve their usefulness at individual level. Testes could be clearly identified with the CT from the end of the third week of hCG administration routinely used to induce maturation in fish. The volume of testes increased exponentially during hormone treatment, and by the end of the sixth week of maturation procedure all males produced motilable spermatozoa. Present results prove that testes size can noninvasively be monitored with CT from maturity level where testes size rich 3000 mm3 volume. Eye and nose indexes are in close correlation with testes volume and thus can also be effectively used to monitor maturaty level of male eel, but preferably only at stock level. However, due to their high individual variability, these indexes can be applied only with caution at individual level and should be supplemented with other noninvasive techniques such as CT.