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Biomedical subjects

M Rozek

Publications and source records attributed to M Rozek.

At least 19 recordsLinked to original sources
PubMed2004

C-bands on chromosomes of 32 beetle species (Coleoptera: Elateridae, Cantharidae, Oedemeridae, Cerambycidae, Anthicidae, Chrysomelidae, Attelabidae and Curculionidae).

C-banding patterns of 32 beetle species from the families Elateridae, Cantharidae, Oedemeridae, Cerambycidae, Anthicidae, Chrysomelidae, Attelabidae and Curculionidae were studied using the C-banding technique. Mitotic and meiotic chromosomes were previously described for 14 species. From among 18 species that had never been cytogenetically studied, we determined the diploid and haploid chromosome numbers and the sex determination system for 12 beetles. The karyotype for 6 species is not described because of a lack of mitotic and meiotic metaphases. Results confirm that most of the beetle species possess a small amount of heterochromatin and C-positive segments are weakly visible in pachytene stages and weakly or imperceptible in mitotic and meiotic metaphases. In some species with a large amount of heterochromatin, C-bands were observed in the centromeric region in all autosomes and the X chromosome. The Y chromosome does not show C-bands with the exception of Oedemera viridis in which it possesses a small band of heterochromatin.

Animals↗
PubMed2002

Canine 5S rRNA: nucleotide sequence and chromosomal assignment of its gene cluster in four canid species.

The purpose of this study was to determine the nucleotide sequence of canine 5S rRNA and use this information to develop a molecular probe to assign the gene locus to chromosomes of the dog and three other related canid species using fluorescence in situ hybridization. The nucleotide sequence of canine liver 5S rRNA is 120 base pairs long and identical to the 5S rRNA nucleotide sequence of all other mammalian species investigated so far. A single 5S rRNA gene cluster was localized pericentromerically on chromosomes of four canid species: dog 4q1.3, red fox 4q1.3, blue fox 3q1.3 and Chinese raccoon dog 8q1.3. Chromosome arms carrying the 5S rRNA gene cluster showed striking similarities in their QFQ banding patterns, suggesting high conservation of these chromosome arms among the four species studied. The chromosomal assignments of 5S rRNA genes are among the first gene mapping results for the blue fox and the Chinese raccoon dog, and are in accordance with published data on comparative chromosome maps from human, dog, red fox, blue fox and raccoon dogs.

Animals↗
PubMed2001

Cytogenetic investigations on seven Palaearctic weevil species (Coleoptera, Curculionidae).

Cytogenetic investigations were carried out on seven species of bisexual weevils from five subfamilies. The following numbers of chromosomes were found in individual species: 2n = 22, n male = 10 + Xyp in Ptochus porcellus Boh. (Otiorhynchinae); 2n = 40, n male = 19 + Xyp in Larinodontes turbinatus Gyll. (Cleoninae); 2n = 26, n male = 12 + Xyp in Curculio pellitus (Boh.) (Curculioninae); 2n = 30, n male = 14 + Xyp in Acalles camelus (F.), Acalles echinatus (Germ.), Acalles hypocrita Boh. (Cryptorhynchinae), and 2n = 40, n male = 19 + Xyp in Cionus hortulanus (Foucr.) (Mecininae). The heterochromosomes of all the examined species form, in the first meiotic metaphase, a parachute bivalent. The chromosome number and sex determining system of six species and two genera are described for the first time.

Animals↗
PubMed2001

C-bands on chromosomes of four beetle species (Coleoptera: Carabidae, Silphidae, Elateridae, Scarabaeidae).

The C-banding pattern of Bembidion geniculatum, Silpha atrata, Prosternon tesselatum, and Epicometis hirta are presented. All analysed species have pracentromeric C-bands on autosomes and chromosome X but the widest ones are visible in the karyotype of B. geniculatum. In S. atrata, P. tesselatum, and E. hirta sex chromosome y is heterochromatic, only B. geniculatum having the Y chromosome wholly euchromatin. The results indicate that on the chromosomes of the investigated species do not have a terminal and an intercalar segments of heterochromatin.

Animals↗
PubMed2000

Karyological notes on three weevil species from Armenia (Coleoptera, Curculionidae, Cleoninae).

Karyological studies were carried out on three Armenian weevil species from the subfamily Cleoninae. The following chromosome numbers were found in individual species: 2n = 38, n Male = 18 + Xyp in Menecleonus anxius (Gyllenhal, 1824), 2n = 40, n Male = 19 + Xyp in Conorhynchus nigrivittis (Pallas, 1781) and 2n = 44, n Male = 21 + Xyp in Lixus iridis Olivier, 1807. The heterochromosomes of all the examined species form, in the first meiotic metaphase, a typical parachute bivalent.

Animals↗
PubMed2000

The C-banding technique for Coleoptera (Insecta).

The heterochromatin bands were obtained after modification of standard procedure. The modification eliminated or greatly reduced treatment in 0.2 N HCL, and prolong treatment in Ba(OH)2.(8H2O), in decreased temperature of Ba(OH)2.(8H2O) and 2xSSC.

Animals↗
PubMed2000

C-banding patterns in chromosomes and sperm of Strophosoma capitatum (De Geer, 1775) (Coleoptera: Curculionidae, Brachyderinae).

An analysis was made of the C-banded karyotype of Strophosoma capitatum (Deg.). The results indicate that the chromosome number is 2n = 22 and n Male = 10 + Xyp. The examined karyotype shows a pericentromeric position of constitutive heterochromatin in all autosomes. The shorter arm of the X chromosome is heterochromatic while the y chromosome is wholly euchromatic. Successive stages of spermatogenesis were analysed.

Animals↗
PubMed1998

Modular evolution of the Glx-tRNA synthetase family--rooting of the evolutionary tree between the bacteria and archaea/eukarya branches.

The accuracy of protein biosynthesis generally rests on a family of 20 aminoacyl-tRNA synthetases, one for each amino acid. In bacteria, archaea and eukaryotic organelles, the formation of Gln-tRNA(Gln) is prevalently accomplished by a transamidation pathway, aminoacylation of tRNA(Gln) with Glu by glutamyl-tRNA synthetase (GluRS) followed by a tRNA-dependent transamidation of Glu from Glu-tRNA(Gln). A few bacterial species, such as Escherichia coli, possess a glutaminyl-tRNA synthetase (GlnRS), responsible for Gln-tRNA(Gln) formation. Phylogenetic analysis of the GluRS or GlnRS families (GlxRS) suggested that GlnRS has a eukaryotic origin and was horizontally transferred to a restricted set of bacteria. We have now isolated an additional GlnRS gene from the plant Lupinus luteus and analyzed in more details the modular architecture of the paralogous enzymes GluRS and GlnRS, starting from a large data set of 33 GlxRS sequences. Our analysis suggests that the ancestral GluRS-like enzyme was solely composed of the catalytic domain bearing the class-defining motifs of aminoacyl-tRNA synthetases, and that the anticodon-binding domain of GlxRSs was independently acquired in the bacteria and archaea branches of the universal tree of life, the eukarya sub-branch arising as a sister group of archaea. The transient capture of UAA and UAG codons could have favored the emergence of a GlnRS in early eukaryotes.

Amino Acid Sequence↗
PubMed1998

[Combined hemostatic defects in family members of symptomatic carriers of Leiden mutations of factor V].

The aim of the study was to determine the frequency of additional prothrombotic defect in family members of 14 symptomatic, heterozygous carriers of factor V Leiden mutation (FV Leiden). The FV Leiden was found in fifty-five from among 127 persons (43%). Thirty-two from 53 (68%) family carriers of FV Leiden had venous thromboembolic disease at the time of examination. Combined defects were found in 6 out of 14 families (in 4 families coexistence of FV Leiden mutation with protein S deficiency, in 1 with G20210 A mutation of prothrombin gene and in 1 with antithrombin III deficiency). Until now 63% (7/11) of combined defect carriers (mean age 48.5 years) and 59% (24/42) of heterozygous FV Leiden carriers (mean age 52.2 years) have been symptomatic. The thrombosis-free survival (Kaplan-Maier analysis) was comparable in combined and in single defect carriers groups.

Antithrombin III Deficiency↗
PubMed1997

An alternative method for identifying the factor V gene Leiden mutation.

The recently described point mutation of nucleotide 1691 of the factor V gene is responsible for the factor V resistance to a cleavage with an activated protein C (APC-resistance). Despite the high sensitivity and specificity of the APC-resistance test as a screening method for the detection of the factor V APC-resistance, there is still a necessity to develop a simple, cheap and accurate DNA-based assay. Herein, two different ASO-PCR methods were used for the detection of the Leiden mutation. The first involved a direct ASO-PCR with a consensus FV N1 primer and a sequence specific primer for the 1691 bp "G" normal allele (FV G1) or a specific primer for the 1691 bp "A" mutant allele (FV A1). The second method consisted of direct ASO-PCR by using the consensus FV N1 primer and one of two primers with an additional T-->G mismatch at the penultimate position from the 3'-end. One primer was specific for the 1691 bp "G" normal allele (FV G2) and the other was specific for the 1691 bp "A" mutant allele (FV A2). These permit clear and easy distinctions between homozygous normal and heterozygous and homozygous mutant probands. We also tested a T-->A mismatched primer to compare our method with that recently reported by Bellisimo et al. We found that within a large range of PCR conditions, T-->G mismatched oligonucleotides discriminated better than T-->A mismatched between three factor V 1691 position genotypes. We therefore recommend our method for the screening of a single 1691G-->A nucleotide mutation in the factor V gene.

Alleles↗
PubMed1997

Cellular adhesion molecules changes in myocardium during first year post heart transplant.

The increased presence of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) in the myocardium after orthotropic heart transplantation (OHT) has been implicated in early and late organ rejection. The aim of this study was to investigate the changes in ICAM-1 and VCAM-1 during the first years post-OHT. Accordingly, we studied multiple endomyocardial biopsy specimens collected from 11 randomly selected patients (all males, mean age 46 +/- 11 years). Qualification criteria for OHT included: ischemic cardiomyopathy in 6 pts (55%) and idiopathic dilated cardiomyopathy in 5 pts (45%). All patients were receiving triple immunosuppressive regimen. The therapy consisted of cyclosporine, azathioprine, and prednisolone. Multiple endomyocardial biopsy specimens were collected at 7, 30, 90 and 360 days post OHT from all patients (pts), and examined routinely for histologic signs of organ rejection. To assess levels of adhesion molecules we used monoclonal antibodies (murine anti-human ICAM-1 and VCAM-1) on frozen sections. Immunoreactivity (IR) was detected using a commercially available kit. Intensity of IR was assessed based on a semiquantitative scoring system. In this study, IR scores > or = 2 + were considered positive for ICAM-1, and scores > or = 1 + were considered positive for VCAM-1. IR scores in specimens obtained from consecutive biopsies were compared with the initial biopsy collected at the day 7. The results were analyzed using nonparametric statistics. The routine evaluation revealed histological signs of organ rejection (> or = 2) in 2 pts at 7 days, in 5 pts at 30 days, in 3 pts at 90 days, and in 1 patient at 360 days. On the other hand, ICAM-1 and VCAM-1 expression were absent in the majority of patients at 7, 30 and 90 days, but their presence was significantly increased at 360 days (p < 0.05). Absence of the early expression of ICAM-1 and VCAM-1 may be related to the protective effect of triple immunosuppressive therapy in these patients. The expression of ICAM-1 and VCAM-1 strongly emerging at 1 year post OHT may reflect chronic rejection in myocardium. In conclusion, the immunohistological monitoring of the adhesion molecules in biopsy specimens during routine biopsy schedule may be helpful for the discovery of chronic rejection.

Adult↗
PubMed1996

[Point mutation G-->A nucleotide 1691 factor V gene as a cause of developing thrombotic complications in a family with plasma resistance to activated protein C].

The presence of point mutation G-->A of nucleotide 1691 of Factor V gene (Leiden mutation) is responsible for the resistance of factor Va to activated protein C (APC-resistance) and is associated with an increased risk for thrombosis. Herein, we reported on a case of 20 year male with a two years history of recurrent, extensive deep vein thrombosis. His family history showed grand-mother from mother side, who died from thromboembolic disease many years ago. His laboratory investigation reveals abnormal results of APC-resistance test (R = 1.80) and normalized APC-resistance test sensitivity ratio (0.57). Moreover, on the basis of a sequence specific primer polymerase chain reaction (SSP-PCR) a heterozygous from (G/A at 1691 position) of Leiden mutation was found. Family study showed two between 8 others asymptomatic persons with abnormal results of APC-resistance test and heterozygous genotype.

Adult↗
PubMed1996

[Similar risk of thrombosis complications in heterozygous carriers of Leiden mutation and in patients with idiopathic thromboembolic disease].

The aim of the study was to evaluate the thrombosis free survival in unrelated 24 heterozygous carriers for Leiden mutation and in unrelated 26 patients with "idiopathic" thromboembolic disease. The subjects with coexisting antithrombin III, protein C, S deficiency, obesity, antiphospholipid antibodies, cancer or taking oral contraceptives were excluded from analysis. The clinical manifestations of thrombosis were comparable in both investigated group, similarly the mean age of the first episode occurrence (37.2 vs 41.5 years). The probability for development of thrombosis in Kaplan-Meier analysis was not different between two groups. Moreover, during six months of observation period thrombosis reoccurrence rate was similar (1/24 vs 1/26).

Adult↗
PubMed1995

Cloning and sequencing of the first plant GlnRS and GluRS genes.

We have cloned and sequenced glutamate-tRNA synthetase (GluRS) and glutaminyl-tRNA synthetase (GlnRS) from Arabidopsis thaliana. They have conservative motifs found in all known GlxRS genes. For Lupinus luteus we found only one gene of GlxRS. At the moment we do not know exactly, whether it corresponds to GlnRS or GluRS.

Amino Acid Sequence↗
PubMed1992

Induction of micronuclei in tadpoles of Rana temporaria and Xenopus laevis by the pyrethroid Fastac 10 EC.

The mutagenic properties of the pyrethroid Fastac 10 EC were estimated using the micronucleus test in tadpoles of Rana temporaria and Xenopus laevis. The frequency of erythrocytes with micronuclei was examined in blood smears obtained from animals kept for 14 days in water containing 3 different concentrations of Fastac 10 EC. The study was accompanied by a positive control using the known mutagens cyclophosphamide and N-methyl-N-nitrosourea. The results obtained showed that at high concentrations Fastac 10 EC has a clastogenic activity and/or damages the mitotic spindle, as manifested by a significant increase in the frequency of the micronucleated red blood cells. It was also demonstrated that tadpoles of Rana temporaria are more sensitive to the mutagenic effect of the pyrethroid than are those of Xenopus laevis.

Animals↗
PubMed1990

Health screening goes to work.

On-site health risk assessment and screening can be more than just an employee relations gesture. These screenings at least have the potential to help control health care costs.

Contract Services↗