Authors:P. V. Drion, O. Szenci, F. Ectors, D. Wirth, Zs. Perényi, P. Muller, and J. F. Beckers
The technology of reproduction progressed considerably during the last decade, leading to a certain availability of in vitro methods for fertilisation, oocyte maturation and embryo culture. The most spectacular manipulations are cloning and transgenesis. This review focuses on the early appearance of germinal cell precursors and the long-standing fate of gametes in mammals. The evident complexity and long-term programming of events in gametes and early embryos explain part of the difficulties encountered during the development of in vitro and in vivo methods such as multiple ovulation and embryo transfer (MOET), oestrus synchronisation, ovulation induction, superovulation, in vitro maturation and fertilisation, cryopreservation, transgenesis, nuclear transfer and cloning) and the occurrence of unexpected alterations of development, e.g. embryonic or fetal mortality, large-weight newborn syndrome and other dysregulations in imprinting or DNA transmission.
Authors:G. Raszewski, M. Juszczak, M. K. Lemieszek, J. Matysiak, A. Niewiadomy, and W. Rzeski
The development, optimization, and validation of a new high-performance liquid chromatography ultraviolet (HPLC-UV) method is presented for determining 2-(3-chlorophenyloamino)-5-(2,4-dihydroxy-phenyl)-1,3,4-thiadiazole (ClABT) in biological samples of rat plasma and brain tissue. ClABT was extracted directly from a plasma supernatant fraction following protein precipitation with acetonitrile and high speed centrifugation. Reverse phase HPLC separation was performed using an ODS-2 Hypersil column with the mobile phase consisting of 0.05 M triethylammonium phosphate buffer solution in acetonitrile and methanol (120:280:600, v/v/v), at room temperature, 1.2 mL min−1 flow rate, and UV-diode-array detection (DAD), at 335 nm. A linear response was obtained between 12.5 and 2000 ng mL−1 at analytically acceptable levels of precision (intra/inter-day) and accuracy. Mean recoveries ranged from 92.7% to 107.9%. It was concluded that the method was specific and precise and thus suitable for quantitative analysis in clinical pharmacokinetic studies of ClABT.
Authors:L. Goetz, E. Sabbioni, E. Marafante, J. Edel-Rade, C. Birattari, and M. Bonardi
Carrier-free201+202Tl have been produced in the cyclotron by (p, xn) reactions on mercury targets and used as a trcer for thallium in metallobiochemistry
of heavy metal pollution. The separation of201+202Tl radioisotopes from Hg involved a solvent extraction method leading to labelled univalent Tl(I) ions. This radioactive solution
was used to prepare different201+202Tl labelled compounds such as inorganic Tl(III) ions and organic dimethylthallium. Quality controls have been applied directly
on the different radioactive solutions immediately before their administrations to rats in order to ensure that thallium had
the chemical form expected. A summary of the main results concerning different aspects of the metabolic investigations on
rats such as absorption, retention, excretion, transplacental transport and influence of the different chemical forms of thallium
on its metabolism is also reported.
Authors:I. Czegle, É. Margittai, S. Senesi, A. Benedetti, and G. Bánhegyi
11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) is a NADPH dependent oxidoreductase of the endoplasmic reticulum lumen which converts cortisone to cortisol and plays a role in the pathogenesis of metabolic syndrome and type 2 diabetes. The aim of our study was to investigate the correlation between the expression/activity of 11βHSD1 and obesity. Liver and adipose tissue microsomes of an obese (Zucker) and a non-obese (Goto-Kakizaki) type 2 diabetes model rat strains were used. 11βHSD1 expression was detected at mRNA, protein and activity level. The activity of 11βHSD1 was increased in the adipose tissue and decreased in the liver of the obese Zucker rat, while its mRNA levels were significantly different only in the adipose tissue. In diabetic Goto-Kakizaki rat both the expression and the activity of 11βHSD1 were elevated in liver, but not in adipose tissue. These results suggest that the prereceptorial glucocorticoid activation is different in the liver and adipose tissue of the two diabetes models. This phenomenon might be responsible for the obese and lean phenotypes in type 2 diabetes.
Authors:N. Pilecká, M. Rakovič, F. Vîtek, J. Šilar, and M. Hyťha
An experiment on rabbits was carried out with the aim to check results obtained formerly with the help of the neutron activation analysis indicating that Na+ ions can be /by contrast to K+ ions/ only very slowly removed from the bone tissue by extraction with water. The data resulting from a radiotracer experiment with22Na are in a good agreement with the above mentioned results.
Authors:J. Crudo, M. Edreira, E. Obenaus, and S. de Castiglia
Rhenium-188 is a high energy -emitter that has a therapeutic promise. The aim of the present study was to label the anti-melanoma 14f7 monoclonal antibody (MoAb) with 188Re, using an active ester of S-benzoyl-mercaptoacetyltriglycine (S-benzoyl-MAG3) and to evaluate its tumor uptake in C57 mice bearing a B16F0 melanoma. The optimum labeling efficiency was 49.6% and the maximal tumor uptake was 8.8%ID/g at 24 hours. Quality assurance tests were performed during the entire labeling procedure and on the final radiolabeled MoAb. Stability studies in saline and human serum were also performed.
Authors:E. Bajmócy, Ibolya Turcsányi, G. Bölske, Á. Bacsadi, and I. Kiss
Varga, J., Tuboly, S. and Mészáros, J. (1999): Infectious Diseases of Domestic Animals. Veterinary Epidemiology II (in Hungarian). Mezőgazdasági Kiadó, Budapest, 1999.
Infectious Diseases of Domestic Animals