Volume 49 (2003) No. 3

Intraembryonic Avian Leukosis Virus Subgroup C (ALV-C) Inoculation Producing Wasting Disease
in Ducks Soon after Hatching
V. STEPANETS, Z. VERNEROVÁ, M. VILHELMOVÁ, J. GERYK, J. PLACHÝ, J. HEJNAR,
F. WEICHOLD, J. SVOBODA

We have studied the pathogenic changes in Khaki Campbell ducks injected in mid embryogenesis with
ALV subgroup C virus td daPR-C derived from a molecular clone. The employed duck flock was shown to
be highly genetically homogeneous and was controlled for the absence of current infections. Clear symptoms of wasting disease,
which appeared since one week post hatching, represented the early consequence of the virus infection. They were manifested by
decreased body weight, including clear involution of thymic tissue and pronounced anaemia. Microscopically, thymuses of infected animals displayed lymphatic depletion, clearly visible in the lobular cortex. Similarly, in the bursa Fabricii follicles, a marked reduction
of the cortical layer and a decrease in folicullar centres was revealed. A decrease in the antibody response correlated with bursa
Fabricii atrophy.  The clear signs of anaemia were confirmed by haematological measurements, red blood cell count, haematocrit value and haemoglobin included. On the basis of these and additional observations we propose that inoculation of duck embryos provides a
suitable model for analysis of the wasting disease produced by ALV-C.
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Influence of Lithium on Cell Function in Two Different Cell Systems
S. GABERŠČEK, M. KALIŠNIK, K. PAVLIN, M. PEZDIRC, S. HOJKE

Lithium is widely used in the treatment and prophylaxis of bipolar psychiatric disorders. It accumulates in the thyroid gland and
can cause goitre or thyroid dysfunction. The mechanisms of various effects of the lithium ion on thyroid cells have not been
completely clarified. The aim of our work was to establish whether lithium, in the presence or absence of TSH, stimulates
the synthesis of cAMP; as model systems we used a strain of rat thyroid follicular cells FRTL-5 and a line of Chinese hamster
ovary fibroblasts with the human TSH receptor (CHO-R). Lithium at concentrations of 0.35 mM, 1 mM, 1.4 mM, 1.7 mM
and 2 mM without TSH and at selected concentrations with TSH stimulation significantly increased cAMP synthesis in FRTL-5
and in CHO-R cells when compared with controls without lithium. These results are different from the published data, which
have been unable to confirm the influence of lithium on cAMP synthesis or have even reported the inhibition of cAMP synthesis.
However, in most published investigations only lithium in combination with TSH was tested. In conclusion, lithium was found to
stimulate cAMP synthesis in FRTL-5 cells and in CHO-R cells.
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Xstir Polymorphism and Absence of Sex Linkage in Xenopus laevis ME2 Gene
J. MÁCHA, T. TLAPÁKOVÁ, V. KRYLOV, V. KOPSKÝ

A fragment of ME2 cDNA from exon 2 to exon 11 was sequenced and the sequence submitted to GenBank. Analysis of the intron,
probably intron 13, revealed a polymorphism which is due to the presence of tandem repetitions of Xstir elements. Genetic analysis
of the parents and the offspring showed a standard distribution of intron variants. This distribution was not dependent on sex.  We conclude, contrary to previous reports, that the ME2 gene is not linked to sex. Consequently, the Xstir polymorphism can be used as a tool for genetic analysis.
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Review
Functional Consequences of the Glycophenotype of Squamous Epithelia – Practical Employment
K. SMETANA, Jr., J. PLZÁK, B. DVOŘÁNKOVÁ, Z. HOLÍKOVÁ