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Biomedical subjects

J Dolezel

Publications and source records attributed to J Dolezel.

At least 19 recordsLinked to original sources
PubMed2006

Genome constitution and evolution in Lolium x Festuca hybrid cultivars (Festulolium).

Festulolium hybrids are being increasingly used worldwide as forage grasses. This is due to their superior agronomic characteristics, which combine yield performance of ryegrasses (Lolium multiflorum and L. perenne) and tolerance against abiotic stress of fescues (Festuca pratensis, F. arundinacea and F. arundinacea var. glaucescens). Despite the widespread use, only fragmentary information exists on their genomic constitution. We used genomic in situ hybridization (GISH) to analyze genomic constitution of over 600 plants from almost all commercially available cultivars of Festulolium. Our results revealed a surprisingly large range of variation in the proportions of parental genomes and in the extent of intergenomic recombination. Using fluorescence in situ hybridization (FISH) with probes for ribosomal DNA, we assessed the frequency of recombination and elimination of particular chromosomes and chromosome groups in three contrasting Festulolium cultivars. This study provides novel information that will aid in understanding the relationship between a genetic make-up and the phenotype of Festulolium hybrids. Our results indicate that GISH might be a useful tool to aid in Festulolium breeding and provide data for a more detailed description of registered cultivars.

Chromosomes, Plant↗
PubMed2006

Rare incidence of pulmonary gangrene--algorithm of the treatment.

The pulmonary gangrene is rare and serious disease. Our experience is based on the treatment of the 2 patients with pulmonary gangrene during the last twenty years. The first and lifesaving step in the treatment of sepsis is the early removal of the necrotic tissue. Next surgery succeeds usually after one week after initial treatment. Surgical treatment continues step by step, we do not advise providing of a major anatomical resection in the initial stage of the disease. This policy is effective in the treatment of this serious disease.

Algorithms↗
PubMed2005

Assessment of ploidy stability of the somatic embryogenesis process in Quercus suber L. using flow cytometry.

Flow cytometry analyses were used to verify the ploidy stability of Quercus suber L. somatic embryogenesis process. Leaf explants of two adult cork oak trees (QsG0 and QsG5) of the North of Portugal were inoculated on MS medium with 2,4-D and zeatin. After 3 months, calluses with embryogenic structures were isolated and transferred to fresh MS medium without growth regulators and somatic embryo evolution was followed. Morphologically normal somatic embryos (with two cotyledons) and abnormal somatic embryos (with one or three cotyledons) were used in this assay. Flow cytometry combined with propidium iodide staining was employed to estimate DNA ploidy levels and nuclear DNA content of somatic embryos and leaves from mother plants. No significant differences (P< or =0.05) were detected among embryos, and between the embryos and the mother plants. Also, after conversion of these embryos, no significant morphological differences were observed among the somatic embryo-derived plants. These results and further studies using converted plantlet leaves and embryogenic callus tissue indicate that embryo cultures and converted plantlets were stable with regard to ploidy level. As no major somaclonal variation was detected our primary goal of "true-to-type" propagation of cork oak using somatic embryogenesis was assured at this level. The estimation of the 2C nuclear DNA content for this species is similar to the previously obtained value.

Flow Cytometry↗
PubMed2005

Nuclear genome size and genomic distribution of ribosomal DNA in Musa and Ensete (Musaceae): taxonomic implications.

Nuclear DNA content and genomic distributions of 5S and 45S rDNA were examined in nineteen diploid accessions of the genus Musa representing its four sections Eumusa, Rhodochlamys, Callimusa and Australimusa, and in Ensete gilletii, which was the outgroup in this study. In the Eumusa (x = 11), 2C DNA content ranged from 1.130 to 1.377 pg, M. balbisiana having the lowest DNA content of all sections. M. beccarii (x = 9), a representative of Callimusa, had the highest 2C nuclear DNA content (1.561 pg). Species belonging to Rhodochlamys (x = 11) and Australimusa (x = 10) had 2C DNA contents ranging from 1.191 to 1.299 pg and from 1.435 to 1.547 pg, respectively. E. gilletii (x = 9) had 2C DNA content of 1.210 pg. The number of 5S rDNA loci in Musa varied from 4 to 8 per diploid cell. While different numbers of 5S rDNA loci were observed within Eumusa and Rhodochlamys, four 5S rDNA loci were observed in all accessions of Australimusa. M. beccarii (Callimusa) and E. gilletii contained 5S rRNA gene clusters on five and six chromosomes, respectively. The number of 45S rDNA loci was conserved within individual sections. Hierarchical cluster analysis of genome size, number of chromosomes and 45S rDNA sites suggested a close relationship between Rhodochlamys and Eumusa; Australimusa was clearly separated as were M. beccarii and E. gilletii. Within the Eumusa-Rhodochlamys group, M. balbisiana, M. schizocarpa and M. ornata formed distinct subgroups, clearly separated from the accessions of M. acuminata, M. mannii, M. laterita and M. velutina, which formed a tight subgroup. The results expand the knowledge of genome size and genomic distribution of ribosomal DNA in Musa and Ensete. They aid in clarification of the taxonomical classification of Musa and show a need to supplement the analyses on the DNA sequence level with cytogenetic studies.

Cell Nucleus↗
PubMed2005

Peroxisome proliferator-activated receptors (PPAR) agonists affect cell viability, apoptosis and expression of cell cycle related proteins in cell lines of glial brain tumors.

The nuclear receptors PPARs (peroxisome proliferator-activated receptors) are transcription factors activated by specific ligands. PPARs play an important role in carcinogenesis, inflammation, atherosclerosis, lipid metabolism and diabetes. There is evidence that activation of PPARs by specific ligands is able to suppress the growth of different types of human cancer by mechanisms including the growth arrest, apoptosis and induction of differentiation, although the detailed signalling pathways have not been completely elucidated to date. The aim of our study was to determine whether synthetic ligands of PPARalpha and PPARgamma could affect the viability, proliferation, differentiation, apoptosis and expression of some cell cycle related proteins in glial tumor cell lines. The study was performed on human glioblastoma cell lines U-87 MG, T98G, A172 and U-118 MG. Cell lines were treated by ligands of PPARalpha (bezafibrate, gemfibrozil) and PPARgamma (ciglitazone). MTT, flow cytometry, TUNEL assay and immunoblotting were used for detection of changes in cell viability, proliferation, differentiation and apoptosis. Bezafibrate, ciglitazone and gemfibrozil inhibited viability of glioblastoma cell lines. The synthetic ligands significantly reduced or induced the expression of cyclins, p27Kip1, p21Waf1/Cip1, MDM-2, Bcl-2, Bax, PARP, Caspase 3, androgen receptors, etc. and did not affect the expression of the differentiation marker GFAP. Flow cytometry confirmed arrest of the cell cycle although the detection of apoptosis was controversial. Apart from hypolipidemic and hypoglycaemic effects, PPAR ligands may also have significant cytostatic effects of potential use in anticancer treatment.

Apoptosis↗
PubMed2004

High-resolution FISH on super-stretched flow-sorted plant chromosomes.

A novel high-resolution fluorescence in situ hybridisation (FISH) strategy, using super-stretched flow-sorted plant chromosomes as targets, is described. The technique that allows longitudinal extension of chromosomes of more than 100 times their original metaphase size is especially attractive for plant species with large chromosomes, whose pachytene chromosomes are generally too long and heterochromatin patterns too complex for FISH analysis. The protocol involves flow cytometric sorting of metaphase chromosomes, mild proteinase-K digestion of air-dried chromosomes on microscopic slides, followed by stretching with ethanol:acetic acid (3 : 1). Stretching ratios were assessed in a number of FISH experiments with super-stretched chromosomes from barley, wheat, rye and chickpea, hybridised with 45S and 5S ribosomal DNAs and the [GAA]n microsatellite, the [TTTAGGG]n telomeric repeat and a bacterial artificial chromosome (BAC) clone as probes. FISH signals on stretched chromosomes were brighter than those on the untreated control, resulting from better accessibility of the stretched chromatin and maximum observed sensitivity of 1 kbp. Spatial resolution of neighbouring loci was improved down to 70 kbp as compared to 5-10 Mbp after FISH on mitotic chromosomes, revealing details of adjacent DNA sequences hitherto not obtained with any other method. Stretched chromosomes are advantageous over extended DNA fibres from interphase nuclei as targets for FISH studies because they still retain chromosomal integrity. Although the method is confined to species for which chromosome flow sorting has been developed, it provides a unique system for controlling stretching degree of mitotic chromosomes and high-resolution bar-code FISH.

Chromosomes, Artificial, Bacterial↗
PubMed2004

Intraabdominal pressure after rectal resections.

The mean correlation curves of the intraabdominal pressure over time were evaluated by regression analysis (value 0.05) in both groups. The curves had a rising character in both groups, but in the control group the curve rose more steeply and reached a higher level than the curve of studied group. The onset of peristalsis, first flatus and stool took a shorter time in the studied group. (Tab. 1, Fig. 5, Ref. 5.)

Abdomen↗
PubMed2003

Development of a composite map in Vicia faba, breeding applications and future prospects.

A composite map of the Vicia faba genome based on morphological markers, isozymes, RAPDs, seed protein genes and microsatellites was constructed. The map incorporates data from 11 F(2) families for a total of 654 individuals all sharing the common female parent Vf 6. The integrated map is arranged in 14 major linkage groups (five of which were located in specific chromosomes). These linkage groups include 192 loci and cover 1559 cM with an overall average marker interval of 8 cM. By joining data of a new F(2) population segregating for resistance to ascochyta, broomrape and others traits of agronomic interest, have been saturated new areas of the genome. The combination of trisomic segregation, linkage analysis among loci from different families with a recurrent parent, and the analysis of new physically located markers, has allowed the establishment of the present status of the V. faba map with a wide coverage. This map provides an efficient tool in breeding applications such as disease-resistance mapping, QTL analyses and marker-assisted selection.

Agriculture↗
PubMed2003

Analysis and sorting of rye (Secale cereale L.) chromosomes using flow cytometry.

Procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) were developed for rye (Secale cereale L.). Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity obtained after the analysis of DAPI-stained chromosomes (flow karyotypes) were characterized and the chromosome content of the DNA peaks was determined. Chromosome 1R could be discriminated on a flow karyotype of S. cereale 'Imperial'. The remaining rye chromosomes (2R-7R) could be discriminated and sorted from individual wheat-rye addition lines. The analysis of lines with reconstructed karyotypes demonstrated a possibility of sorting translocation chromosomes. Supernumerary B chromosomes could be sorted from an experimental rye population and from S. cereale 'Adams'. Flow-sorted chromosomes were identified by fluorescence in situ hybridization (FISH) with probes for various DNA repeats. Large numbers of chromosomes of a single type sorted onto microscopic slides facilitated detection of rarely occurring chromosome variants by FISH with specific probes. PCR with chromosome-specific primers confirmed the identity of sorted fractions and indicated suitability of sorted chromosomes for physical mapping. The possibility to sort large numbers of chromosomes opens a way for the construction of large-insert chromosome-specific DNA libraries in rye.

Cell Separation↗
PubMed2003

Videomediastinoscopy for the diagnosis of the diseases of the lung and mediastinum.

BACKGROUND: The biopsy of the mediastinum by mediastinoscopy is established as the most accurate method especially in the lung cancer staging, but helps also in the diagnosis of various diseases of the lung and mediastinum. The videomediastinoscopic equipment offers more precise procedure and shorter learning curve in comparison with classical technique due to the sharing of the procedure with other (more experienced) surgeon. The aim of our work was to confirm the safety and reliability of the videomediastionoscopy in our department, where the use of the traditional technique was exceptional. METHODS: Patients with expansion in the mediastinum (or enlargement of the mediastinal lymph nodes) of the unknown aetiology accessible by videomediastinoscopy according to CT were included. Standard videomediastinoscopic technique was used. The attempt to take biopsy of the mediastinal tumor and/or the lymph nodes in stations 1, 2, 4, 7 according the UICC regional lymph node mapping was done. RESULTS: There were 126 patients operated by videomediastinoscopy between January 1998 and June 2003. There were 83 men with a mean age of 50.43 years (range 14 to 78 years) and 43 women with a mean age of 50.79 years (range 18 to 77 years). The diagnosis defined by explicit morphology was made in 95 cases (75.40%). In 25 cases (19.84%) the result of the biopsy was either normal lymphatic tissue or slight inflammatory changes. In three cases (2.38%) the pathologist expressed strong suspicion of the malignant disease, without clear morphology. In two cases (1.59%) all tissue samples were completely necrotic. No biopsy was done once (0.77%). There were four major groups of patients with positive histology: Patients with sarcoidosis, patients with metastases of the epithelial malignity to the mediastinal lymph nodes, patients with lymphoma and the group containing patients with a diagnosis of a low frequency (tuberculosis, sarcoma, Castleman's disease and others). No mortality was related to the procedure. We had one serious surgical complication: bleeding from the right innominate artery successfully treated by suture. CONCLUSION: Videomediastinoscopy is a safe and accurate method with a short learning curve. The key point of the diagnostic success is a proper indication for the procedure. Videomediastinoscopic equipment and its use is to be recommend to each department of general thoracic surgery.

Adolescent↗
PubMed2002

Rapid detection of aneuploidy in Musa using flow cytometry.

We report a procedure for the rapid and convenient detection of aneuploidy in triploid Musa using DNA flow cytometry. From a population of plants derived from gamma-irradiated shoot tips, plants were selected based on aberrant morphology and their chromosome numbers were counted. Aneuploids plants with chromosome numbers 2n=31 or 32 were found as well as the expected triploid plants (2n=3x=33). At the same time, the nuclear DNA content of all plants was measured using flow cytometry. The flow cytometric assay involved the use of nuclei isolated from chicken red blood cells (CRBC), which served as an internal reference standard. The relative DNA content of individual plants was expressed as a ratio of DNA content of CRBC and Musa (DNA index). In order to estimate the chromosome number using flow cytometry, the relative DNA content of plants with unknown ploidy was expressed as a percentage of the DNA content of triploid plants. The classification based on flow cytometry fully agreed with the results obtained by chromosome counting. The results indicated that flow cytometry is a convenient and rapid method for the detection of aneuploidy in Musa.

Aneuploidy↗
PubMed2002

Isolation, characterization and chromosome localization of repetitive DNA sequences in bananas (Musa spp.).

Partial genomic DNA libraries were constructed in Musa acuminata and M. balbisiana and screened for clones carrying repeated sequences, and sequences carrying rDNA. Isolated clones were characterized in terms of copy number, genomic distribution in M. acuminata and M. balbisiana, and sequence similarity to known DNA sequences. Ribosomal RNA genes have been the most abundant sequences recovered. FISH with probes for DNA clones Radkal and Radka7, which carry different fragments of Musa 26S rDNA, and Radka14, for which no homology with known DNA sequences has been found, resulted in clear signals at secondary constrictions. Only one clone carrying 5S rDNA, named Radka2, has been recovered. All remaining DNA clones exhibited more or less pronounced clustering at centromeric regions. The study revealed small differences in genomic distribution of repetitive DNA sequences between M. acuminata and M. balbisiana, the only exception being the 5S rDNA where the two Musa clones under study differed in the number of sites. All repetitive sequences were more abundant in M. acuminata whose genome is about 12% larger than that of M. balbisiana. While, for some sequences, the differences in copy number between the species were relatively small, for some of them, e.g. Radka5, the difference was almost thirty-fold. These observations suggest that repetitive DNA sequences contribute to the difference in genome size between both species, albeit to different extents. Isolation and characterization of new repetitive DNA sequences improves the knowledge of long-range organization of chromosomes in

Chromosome Mapping↗
PubMed2002

Development of flow cytogenetics and physical genome mapping in chickpea (Cicer arietinum L.).

Procedures for flow cytometric analysis and sorting of mitotic chromosomes (flow cytogenetics) have been developed for chickpea (Cicer arietinum). Suspensions of intact chromosomes were prepared from root tips treated to achieve a high degree of metaphase synchrony. The optimal protocol consisted of a treatment of roots with 2 mmol/L hydroxyurea for 18 h, a 4.5-h recovery in hydroxyurea-free medium, 2 h incubation with 10 micromol/L oryzalin, and ice-water treatment overnight. This procedure resulted in an average metaphase index of 47%. Synchronized root tips were fixed in 2% formaldehyde for 20 min, and chromosome suspensions prepared by mechanical homogenization of fixed root tips. More than 4 x 10(5) morphologically intact chromosomes could be isolated from 15 root tips. Flow cytometric analysis of DAPI-stained chromosomes resulted in histograms of relative fluorescence intensity (flow karyotypes) containing eight peaks, representing individual chromosomes and/or groups of chromosomes with a similar relative DNA content. Five peaks could be assigned to individual chromosomes (A, B, C, G, H). The parity of sorted chromosome fractions was high, and chromosomes B and H could be sorted with 100% purity. PCR on flow-sorted chromosome fractions with primers for sequence-tagged microsatellite site (STMS) markers permitted assignment of the genetic linkage group LG8 to the smallest chickpea chromosome H. This study extends the number of legume species for which flow cytogenetics is available, and demonstrates the potential of flow cytogenetics for genome mapping in chickpea.

Cell Cycle↗
PubMed2002

[Sacral deafferentation and neurostimulation of anterior spinal roots in the treatment of neurogenic bladder in patients with complete transverse spinal lesions--initial clinical experience].

Of those patients who survived the first years after traumatic severing of the spinal cord 85% die from urological complications, their life span being significantly reduced unless they are adequately treated. Sacral deafferentation and electrostimulation of the urinary bladder is in recent years one of the most effective therapeutic methods of neuropathic urinary bladder caused by suprasacral transverse spinal lesions: rhizotomy permanently increases the compliance of the bladder, eliminates hyperreflexion of the detrusor and detrusor-sphincteric dyssynergy--the main causes of nephropathy and urinary incontinence; implantation of a stimulator of the anterior spinal roots enables the patient to control micturition, possibly also defaecation and erection. In countries of the former eastern European bloc the method was not used so far. From January to September 2001 in the Faculty Hospital Brno six patients were operated with complete suprasacral spinal lesions caused by injuries of the spine (from C4 to Th9). All patients recovered without complications. In five patients complete continence was restored, in all six hyperreflexia of the detrusor disappeared completely, four patients use from the second week a neurostimulator for micturition whereby the micturition pressure does not exceed physiological values and the post-micturition residue is negligible. One of the two patients where the response of the bladder to stimulation disappeared during the first week started to use the stimulator again during the 7th month after surgery. Another patient waits now for 5 months for complete regeneration of motor pathways and urinates using intermittent catheterization. Four patients use from the very beginning a neurostimulator for defaecation and one for assisted defaecation. Four patients evaluate the result of surgery as excellent, one as good and he expects further improvement from the effect of stimulation, he objects to the stress incontinence of urine. One patient appreciates the restored urinary continence, but awaits the restored effect of stimulation and therefore is not yet satisfied with the operation.

Adult↗
PubMed2002

Significance of a prolonged postoperative bowel paralysis in complete dehiscence of laparotomy wound.

We performed 910 laparotomies in the years 1998-1999. Complete dehiscence of a laparotomy wound was observed in 18 cases. We compare the duration of postoperative bowel paralysis in patients with and without eventration. The statistical comparison of the two groups was performed with the Wilcoxon test, the level of significance was set to 5%. We have found that the duration of postoperative bowel paralysis was significantly longer in the group of patients with eventration. (Tab. 4, Ref. 5.).

Aged↗
PubMed2001

Heterogeneity of rDNA distribution and genome size in Silene spp.

Genus Silene L. (Caryophyllaceae) contains about 700 species divided into 44 sections. According to recent taxonomic classification this genus also includes taxa previously classified in genera Lychnis and Melandrium. In this work, four Silene species belonging to different sections were studied: S. latifolia (syn. Melandrium album, Section Elisanthe), S. vulgaris (Inflatae), S. pendula (Erectorefractae), and S. chalcedonica (syn. Lychnis chalcedonica, Lychnidiformes). Flow cytometric analysis revealed a genome size of 2.25 and 2.35 pg/2C for S. vulgaris and S. pendula and of 5.73 and 6.59 pg/2C for S. latifolia and S. chalcedonica. All four species have the same chromosome number including the pair of sex chromosomes of the dioecious S. latifolia (2n = 2x = 24). Double target fluorescence in-situ hybridization revealed the chromosomal locations of 25S rDNA and 5S rDNA. A marked variation in number and localization of rDNA loci but no correlation between the numbers of rDNA clusters and genome size was found. FISH and genome size data indicate that nuclear genomes of Silene species are highly diversified as a result of numerous DNA amplifications and translocations.

Cell Nucleolus↗