[Thrombohaemorrhagic syndrome in patients with a myeloproliferative disease with thrombocythemia]. / Trombohemoragický syndrom u nemocných s myeloproliferativním onemocnenim s trombocytemií.

Thrombohaemorrhagic syndrome is a clinical syndrome manifesting with concurrent bleeding and thrombosis. It is associated with a range of pathological states, typically with myeloproliferative diseases, paraproteinaemia, liver disease as well as disseminated intravascular coagulation and similar syndromes (so called DIC-like syndrome). Thrombohaemorrhagic syndrome might be a symptom of chronic myeloproliferations, particularly if these are associated with thrombocythemia. It is most frequently linked to essential thrombocythemia. However, in this disease, it seems that the clinical symptoms of bleeding and thrombosis might not be directly determined by the number of platelets, as it would suggest itself, but that this can be consequent to other changes. These may include predisposition to thrombophilia, cardiovascular risk, leukocytosis etc. as well as, for example, platelet dysfunction. The present study focuses on platelet dysfunction in conjunction with clinical symptoms of bleeding and thrombosis.

Cold stress and acclimation - what is important for metabolic adjustment?

As sessile organisms, plants are unable to escape from the many abiotic and biotic factors that cause a departure from optimal conditions of growth and development. Low temperature represents one of the most harmful abiotic stresses affecting temperate plants. These species have adapted to seasonal variations in temperature by adjusting their metabolism during autumn, increasing their content of a range of cryo-protective compounds to maximise their cold tolerance. Some of these molecules are synthesised de novo. The down-regulation of some gene products represents an additional important regulatory mechanism. Ways in which plants cope with cold stress are described, and the current state of the art with respect to both the model plant Arabidopsis thaliana and crop plants in the area of gene expression and metabolic pathways during low-temperature stress are discussed.

Quantification of Pyrenophora teres in infected barley leaves using real-time PCR.

Net blotch is a barley foliar disease caused by two forms of Pyrenophora teres: Pyrenophora teres f. teres (PTT) and Pyrenophora teres f. maculata (PTM). To monitor and quantify their occurrence during the growing season, diagnostic system based on real-time PCR was developed. TaqMan MGB (Minor Groove Binder) primers and probes were designed that showed high specificity for each of the two forms of P. teres. As a host plant internal standard, TaqMan MGB primers and probe based on RacB gene sequence were designed. The method was optimised on pure fungal DNA and on plasmid standard dilutions. Quantification was accomplished by comparing Ct values of unknown samples with those obtained from plasmid standard dilutions. The assay detects down to five gene copies per reaction. It is able to produce reliable quantitative data over a range of six orders of magnitude. The developed assay was used to differentiate and quantify both forms of P. teres in infected barley leaves. Correlation R(2)=0.52 was obtained between the Ct values and size of symptoms areas in early stage of infection. Application of the TaqMan MGB technology to leaf samples collected in 20 barley varieties in the region Kromeriz during the growing season of 2003 and 2004 revealed that P. teres f. teres predominated in these 2 years. The developed method is an important tool to quantify and monitor the dynamics of the two forms of P. teres during the growing season.

Coding region single nucleotide polymorphism in the barley low-pI, alpha-amylase gene Amy32b.

Barley alpha-amylase variability influences the quality of barley grain in the brewing, feed and food industries. alpha-Amylase proteins are encoded by multigene families in cereals, and this study focused on the barley Amy32b gene. We identified coding region single nucleotide polymorphism (cSNP) and insertion/deletion variation in DNA sequences, which resulted in amino acid substitution and stop codon formation, respectively. The substitution affected the beta1 strand in domain C, whereas the stop codon removed the beta5 strand. Possible effects of these changes on the protein are discussed. A cSNP in the coding region of the Amy32b gene was used as a specific marker to map Amy32b loci on chromosome 7H.

Characterization of two bifunctional Arabdopsis thaliana genes coding for mitochondrial and cytosolic forms of valyl-tRNA synthetase and threonyl-tRNA synthetase by alternative use of two in-frame AUGs.

We characterized two Arabidopsis thaliana cDNAs coding for class I valyl-tRNA synthetase and class II threonyl-tRNA synthetase. The proteins display characteristics of cytosolic enzymes, yet possess an N-terminal extension relative to their prokaryotic homologs. The proximal part of the N-terminal extension is a mitochondrial-targeting signal. Through transient expression of GFP fusions in tobacco cells, we demonstrated that both genes encode the cytosolic and mitochondrial forms of the enzymes by alternative use of two in-frame initiation codons. A long, mitochondrial form of the enzyme is translated from a first initiation codon at reduced levels because of a poor sequence context and a shorter, cytosolic form is translated from a second in-phase AUG, which is in a better context for translation initiation. Primer extension experiments revealed several transcript ends mapping upstream of the first AUG and between the two AUGs. Distal to the mitochondrial transit peptide both valyl-tRNA synthetase and threonyl tRNA synthetase possess an NH2-appended domain compared with their prokaryotic counterparts. This domain's amphiphilic helix is conserved between yeast and A. thaliana valyl-tRNA synthetase, suggesting an important role in translation. Based on the high structural similarities between yeast and A. thaliana valyl-tRNA synthetase, we propose that the acquisition of bifunctionality of valyl-tRNA synthetase predates the divergence of these two organisms.