Report of first experience with endoscopic ultrasonography in Slovak Republic.

BACKGROUND: Endoscopic ultrasonography (EUS) is a method that takes the advantage of a combination of endoscopy and ultrasound, where a miniature probe that functions as a transducer (which functions as both a transmitter and a receiver of ultrasound), is incorporated in the tip of the endoscope. From the introduction, this modality has found it s uninterchangable place all over the world not only in the diagnosis, but also in the therapy of gastrointestinal diseases and the diseases of the surrounded structures and organs. Indications for EUS can be simply divided into three main categories: submucosal abnormalities, staging of tumors of the gastrointestinal tract and pancreatobiliary diseases. In December 2000 we began at the Clinic of Gastroenterology of Slovak Postgraduate Academy of Medicine at St. Cyril and Method s Hospital in Bratislava, Slovak Republic with the EUS evaluation with radial mechanical probe, as the first one in the Slovak Republic. In this article we describe our first experience with the EUS at our clinic. CONCLUSIONS: All together 64 patients were evaluated from December 2000 to the end of March 2001 from all over the Slovakia. In this article we describe in more detailed form the indications and also the findings in our group of patients.

[Use of beta-blockers in the treatment of chronic heart failure]. / Nástup betablokátorov do liecby chronického zlyhávania srdca?

Recently in the world literature with increasing frequency reports are found on clinical studies investigating the use of beta-blockers in the treatment of chronic heart failure. The authors present a review of the problem comprising pathophysiological mechanisms at a receptor level up to investigations of the effect of beta-blockers on haemodynamics, the functional state of the left ventricle and survival. Although this promising and frequently controversial treatment is not accepted universally so far, partial data in the mentioned investigations indicate that when a more accurate dosage pattern is established and indications are specified in more detail, the use of beta-blockers is one way how to approach - in addition to the use of diuretics, cardiotonics and angiotensin converting enzyme inhibitors - a comprehensive therapeutic control of chronic heart failure.

Genetic studies of frost resistance in wheat.

Genetic studies of frost resistance were performed on various wheat varieties using diallel, F2 monosomic and substitution analysis.A six-parental cross including reciprocals was carried out, and F1 hybrids and their parents were used for the freezing tests under controlled conditions. Both the general combining ability (GCA) and the specific combining ability (SCA) were significant, indicating additive and non-additive gene action in the inheritance of frost resistance. The high GCA∶SCA ratio revealed a preponderance of additive genetic variance. No significant reciprocal differences were found between the reciprocal crosses. The variance/covariance graphical analysis indicated the partial dominance of frost sensitivity. Frost sensitive varieties had the largest number of dominant genes, while frost resistant varieties had the highest proportion of recessive genes. The magnitude of the additive component of variation was higher than that of the dominance component, and the overall measure of the degree of dominance was smaller than one, so average dominance is incomplete. The increasing and decreasing alleles are not equally frequent at all loci. In this set of wheat varieties the values of narrow and broad heritability are relatively high.F2 monosomic analysis of the winter wheat variety 'Arthur' crossed with the monosomics of 'Chinese Spring' revealed that the average frost resistance of all the 21 monosomics was lower than that of the disomic. F2 monosomic hybrids 5A, 2B, 4B and 5D proved to be relatively frost resistant, while monosomics 3A, 3B and 6D were the most sensitive.The control of frost resistance in the set of chromosome substitution lines of the variety 'Cheyenne' into 'Chinese Spring' (with the exception of 2B) indicated that the genes responsible for the frost resistance of 'Cheyenne' are localised in chromosomes 5A, 7A, 4B, 5B, 4D and 5D.The genetic basis of frost resistance and problems of analysis are discussed.

Production and meiotic pairing behaviour of new hybrids of winter wheat (Triticum aestivum) x winter barley (Hordeum vulgare).

New winter wheat (Triticum aestivum L.) x winter barley (Hordeum vulgare L.) hybrids produced using cultivated varieties (wheat 'Martonvásári 9 krl'(Mv9 krl) x barley 'Igri', Mv9 krl x 'Osnova', 'Asakazekomugi' x 'Manas') were multiplied in tissue culture because of the high degree of sterility and then pollinated with wheat to obtain backcross progenies. Meiotic analysis of the hybrids Mv9 krl x 'Igri' and 'Asakazekomugi' x 'Manas' and their in vitro regenerated progenies with the Feulgen method revealed 1.59 chromosome arm associations per cell in both initial hybrids. The number of chromosome arm associations increased after in vitro culture to 4.72 and 2.67, respectively, in the two combinations. According to the genomic in situ hybridization (GISH) analysis, wheat-barley chromosome arm associations made up 3.6% of the total in the initial Mv9 krl x 'Igri' hybrid and 6.6% and 16.5% of the total in in vitro regenerated progenies of the 'Asakazekomugi' x 'Manas' and Mv9 krl x 'Igri' hybrids, respectively. The demonstration by GISH of wheat-barley chromosome pairing in the hybrids and especially in their in vitro regenerated progenies proves the possibility of producing recombinants between these two genera, and thus of transferring useful characters from barley into wheat. In vitro conditions caused an increase in chromosome arm association frequency in both combinations and in fertility in some regenerants.

Possible chromosomal location of genes determining the osmoregulation of wheat.

Stress-induced free amino acid accumulation in the presence of 0.7 M mannitol has been compared in tissue cultures of moderately stress-tolerant 'Chinese Spring' and stress-sensitive 'Cappelle Desprez' cultivars and in disomic chromosome substitution lines of 'Cappelle Desprez' into 'Chinese Spring'. The profile of amino acid accumulation was different in the two parents. The amino acid concentration of the substitution lines belonging to the A, B and D genomes, respectively, altered characteristically under stress condition. The 'Cappelle Desprez' chromosomes associated with non-ionic osmotic stress-induced free amino acid accumulation were 5A and 5D.

Mapping genes affecting flowering time and frost resistance on chromosome 5B of wheat.

Two populations of single chromosome recombinant lines were used to map genes controlling flowering time on chromosome 5B of wheat, and one of the populations was also used to map a new frost resistance gene. Genetic maps were developed, mainly using microsatellite markers, and QTL analysis was applied to phenotypic data on the performance of each population collected from growth-room tests of flowering time and frost tolerance. Using a recombinant substitution-line mapping population derived from a cross between the substitution-line 'Chinese Spring' ('Cheyenne' 5B) and 'Chinese Spring' (CS), the gene Vrn-B1, affecting vernalization response, an earliness per se locus, Eps-5BL1, and a gene, Fr-B1, affecting frost resistance, were mapped. Using a 'Hobbit Sib' ('Chinese Spring' 5BL) x 'Hobbit Sib' recombinant substitution line mapping population, an earliness per se locus, Eps-5BL2 was mapped. The Vrn-B1 locus was mapped on the distal portion of the long arm of chromosome 5B, to a region syntenous with the segments of chromosomes 5A and 5D containing Vrn-A1 and Vrn-D1 loci, respectively. The two Eps-5BL loci were mapped close to the centromere with a 16-cM distance from each other, one in agreement with the position of a homoeologous locus previously mapped on chromosome 5H of barley, and suggested by the response of 'Chinese Spring' deletion lines. The Fr-B1 gene was mapped on the long arm of chromosome 5B, 40 cM from the centromeric marker. Previous comparative mapping data with rice chromosome 9 would suggest that this gene could be orthologous to the other Fr genes mapped previously by us on chromosomes 5A or 5D of wheat, although in a more proximal position. This study completes the mapping of these homoeoallelic series of vernalization requirement genes and frost resistance genes on the chromosomes of the homoeologous group 5 in wheat.

RFLP mapping of the vernalization (Vrn1) and frost resistance (Fr1) genes on chromosome 5A of wheat.

A population of single chromosome recombinant lines was developed from the cross between a frost-sensitive, vernalization-insensitive substitution line, 'Chinese Spring' (Triticum spelta 5A) and a frost-tolerant, vernalization-sensitive line, 'Chinese Spring' ('Cheyenne' 5A), and used to map the genes Vrn1 and Fr1 controlling vernalization requirement and frost tolerance, respectively, relative to RFLP markers located on this chromosome. The Vrn1 and Fr1 loci were located closely linked on the distal portion of the long arm of 5AL, but contrary to previous observations, recombination between them was found. Three RFLP markers, Xpsr426, Xcdo504 and Xwg644 were tightly linked to both. The location of Vrn1 suggests that it is homoeologous to other spring habit genes in related species, particularly the Sh2 locus on chromosome 7 (5H) of barley and the Sp1 locus on chromosome 5R of rye.

Genetic variation at storage protein-coding loci of common wheat (cv 'Chinese Spring') induced by nitrosoethylurea and by the cultivation of immature embryos in vitro.

Electrophoretic patterns of seed storage proteins, the high-molecular-weight glutenins and gliadins, were studied in 468 plants of the common wheat cultivar 'Chinese Spring' regenerated from callus culture of immature embryos, in 115 plants grown from seeds treated with nitrosoethylurea and in 260 control plants. From 5 to 21 single grains were analysed from each plant. In these three groups, the frequency of inherited mutations causing the loss of all proteins controlled by a locus (null-mutations, probably caused by a chromosomal deficiency) was 0.69%, 2.07%, and 0.05% per locus (the differences were statistically significant), respectively, while that of mutations causing the loss of a single protein band was 0.11%, 0.33%, and 0.05%, respectively. The loss of all of the gliadins controlled by Gli-B1 or GH-B2 (mutations were probably caused by a deletion of satellites of the corresponding chromosomes), was significantly higher than the loss of gliadins controlled by genomes A and D. Gene mutations altering the electrophoretic mobility of a single protein band in the pattern were found only in the second group of plants (0.44%). Therefore, chemical mutagenesis which produced not only more mutations than cultivation of immature wheat embryos in vitro, but also a higher ratio of mutations that altered DNA sequences, can be considered as an easier and comparatively more promising way for obtaining new improved variants of loci controlling biochemical characteristics in wheat. Somaclonal variation, on the other hand, was probably mainly caused by chromosomal abnormalities and could therefore hardly be considered as a useful tool in wheat breeding.

Molecular cytogenetic analysis of Aegilops cylindrica host.

The genomic constitution of Aegilops cylindrica Host (2n = 4x = 28, DcDcCcCc) was analyzed by C-banding, genomic in situ hybridization (GISH), and fluorescence in situ hybridization (FISH) using the DNA clones pSc119, pAs1, pTa71, and pTA794. The C-banding patterns of the Dc- and Cc-genome chromosomes of Ae. cylindrica are similar to those of D-and C-genome chromosomes of the diploid progenitor species Ae. tauschii Coss. and Ae. caudata L., respectively. These similarities permitted the genome allocation and identification of the homoeologous relationships of the Ae. cylindrica chromosomes. FISH analysis detected one major 18S-5.8S-25S rDNA locus in the short arm of chromosome 1Cc. Minor 18S-5.8S-25S rDNA loci were mapped in the short arms of 5Dc and 5Cc. 5S rDNA loci were identified in the short arm of chromosomes 1Cc, 5Dc, 5Cc, and 1Dc. GISH analysis detected intergenomic translocation in three of the five Ae. cylindrica accessions. The breakpoints in all translocations were non-centromeric with similar-sized segment exchanges.