PubMed Health⌕ Search

Biomedical subjects

R Słomski

Publications and source records attributed to R Słomski.

At least 19 recordsLinked to original sources
PubMed2006

Generation of transgenic rabbits by the novel technique of chimeric somatic cell cloning.

A novel technique of chimeric somatic cell cloning was applied to produce a transgenic rabbit (NT20). Karyoplasts of transgenic adult skin fibroblasts with Tg(Wap-GH1) gene construct as a marker were microsurgically transferred into one, previously enucleated, blastomere of 2-cell non-transgenic embryos, while the second one remained intact. The reconstructed embryos either were cultured in vitro up to the blastocyst stage (Experiment I) or were transferred into recipient-females immediately after the cloning procedure (Experiment II). In Experiment I, 25/102 (24.5%) embryos formed blastocysts from whole embryos and 46/102 (44.12%) embryos developed to the blastocyst stage from single non-operated blastomeres, while the reconstructed blastomeres were damaged and degenerated. Thirteen (12.7%) embryos did not exceed 3- to 4-cell stages and 18 (17.7%) embryos were inhibited at the initial 2-cell stage. Out of 14 blastocysts which were subjected to molecular analysis, the transgene was detected in the cells of 4 blastocysts. In Experiment II, 163/217 (75.0%) embryos were transferred into 9 pseudopregnant recipient-rabbits (an average of 18 embryos per recipient). Four recipient-females (44.4%) became pregnant and delivered a total of 24 (14.7%) pups. Molecular analysis confirmed that two pups (1.2%), one live and one stillborn, showed a positive transgene signal. Live transgenic rabbit NT20 appeared healthy and anatomically as well as physiologically normal. The results of our experiments showed that transgenic adult skin fibroblast cell nuclei, which have been introduced into the cytoplasmic microenvironment of single enucleated blastomeres from 2-cell stage rabbit embryos, are able to direct the development of chimeric embryos not only to the blastocyst stage but also up to term.

Animals↗
PubMed2006

Germline MSH2 and MLH1 mutational spectrum including large rearrangements in HNPCC families from Poland (update study).

Germline mutations in the DNA mismatch repair genes MSH2 and MLH1 account for a significant proportion of hereditary non-polyposis colorectal cancer (HNPCC) families. One approach by which development of an efficient DNA-testing procedure can be implemented is to describe the nature and frequency of common mutations in particular ethnic groups. Two hundred and twenty-six patients from families matching the Amsterdam II diagnostic criteria or suspected HNPCC criteria were screened for MSH2 and MLH1 germline mutations. Fifty different pathogenic mutations were found, 25 in MSH2 and 25 in MLH1. Twenty-four of these had not previously been described in other populations. Among our 78 families with MSH2 or MLH1 mutations, 54 (69.2%) were affected by recurrent mutations including 38 found at least twice in our own series. Two of the most frequent alterations were a substitution of A to T at the splice donor site of intron 5 of MSH2 and a missense change (A681T) of MLH1 found in 10 and eight families, respectively. Among large deletions detected by the multiplex ligation-dependent probe amplification assay, exon 9 deletions in the MSH2 gene were found in two families. Our results indicate that a screening protocol specific for the Polish population that is limited to the detection of all reported mutations will result in the identification of the majority of changes present in MLH1 and MSH2 genes in Polish HNPCC kindreds.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Controversial aspect of using GFP as a marker for the production of transgenic cattle.

The objective of this study was to examine the feasibility of identification and selection of cattle embryos based on green fluorescence (GFP-positive) in order to obtain calves carrying an integrated transgene. The construct used (pbLGTNF-EGFP) contained the human tumor necrosis factor alpha (hTNFalpha) gene fused to the bovine beta-lactoglobulin promoter (bLG) in plasmid vector pCX-EGFP. In four experiments, 76 zygotes were injected; eight of them developed to the morulae/blastocysts stage of which only five were GFP positive (one of them 100%, one-50%, three- 25%). All of the GFP positive embryos were transferred to recipients. Two calves were born: one after transfer of the 100% GFP positive embryo and the other after transfer of one of the 25% GFP positive embryos. Both animals were healthy with normal weight when compared to two control calves. The integration of pbLGTNF-EGFP in the host genome could not be detected in either of the calves, suggesting that GFP is an unreliable marker for preimplantation screening of embryos.

Animals↗
PubMed2003

Quantitative mRNA analysis of IL-1 gene system in human testis.

PROBLEM: There is a growing body of evidence that interleukins exhibit modulatory activity on development of reproductive cells. In this context, there appears to be a role for IL-1, which is also produced in human testis. We have analysed transcripts of IL-1 gene system (IL-1alpha, IL-1beta, IL-1RI, IL-1RII and IL-1RA) to evaluate the possible link between the level of gene(s) transcription and their function. METHOD OF STUDY: To determine the activity of gene transcription, a quantitative PCR with isotopic and/or nonisotopic detection was applied. RESULTS AND CONCLUSIONS: We have detected differential expression of IL-1alpha and IL-1beta genes in separate functional compartments of a male gonad. A strong expression of IL-1alpha gene in an intratubular cell fraction was shown, while the IL-1beta expression seemed to be dominant in extratubular compartment of the male gonad. Abundant amounts of IL-1RA mRNA in gametogenic cells fraction slightly higher than in interstitium have also been found. IL-1RA is the most important regulatory molecule in IL-1 system, which down-regulates activity of both interleukins. Looking more closely at gene(s) differential expression it appears that IL-1alpha can be preferentially down-regulated by IL-1RA gene in intratubular fraction while the IL-1beta, through the "false" IL-1RII receptor in the interstitium. Genes coding for both receptors (IL-1RI and IL-1RII) showed, however, relatively low levels of transcription in both studied compartments. IL-1 genes system creates a complex intragonadal environment and the function of these genes is reflected by their respective distribution in the two main functional compartments of the testis.

Base Sequence↗
PubMed2001

Yellow lupine cyclophilin transcripts are highly accumulated in the nodule meristem zone.

Cyclophilin (CyP) is one of the enzymes that act as peptidylprolyl cis-trans isomerases (EC 5.2.1.8). The cDNA and an intronless gene coding for cytosolic CyP have been isolated from yellow lupine. The deduced amino acid sequence of the characterized open reading frame shows approximately 80% homology with cytosolic CyP from other organisms. Southern blots of genomic DNA indicate that there is a small family of genes for CyP-related genes in the yellow lupine genome. RNA blot analyses demonstrate that CyP genes are expressed in all plant organs. The amount of CyP transcripts is dramatically increased in root nodules. In situ hybridization experiments indicate that CyP transcripts are localized mainly in meristematic tissues, with the highest level observed in the nodule meristem zone. The promoter of the sequenced gene contains 5' AAAGAT 3' and AT-rich motifs that are characteristic for some nodulin promoters.

Base Sequence↗
PubMed1996

[Analysis of angiotensin converting enzyme (ACE) polymorphism in patients with myocardial infarction in the Polish population].

Analysis is presented of polymorphism of gene specifying angiotensin converting enzyme in Polish population and its comparison with results obtained for control group. Insertion/deletion polymorphism was detected by polymerase chain reaction. Frequencies of I/D alleles in control group were similar to those reported in French population but different frequencies were observed in patients with myocardial infarction.

Base Sequence↗
PubMed1995

[Repeats of DNA].

Explore the source record for details and available documents.

Base Sequence↗
PubMed1989

Application of non-radioactive methods of DNA detection in analysis of human genetic disorders.

We have applied two non-radioactive methods for detection of unique sequences in human genome: 1 polymerase chain reaction, 2 hybridization with digoxigenin-deoxyuridine 5-triphosphate labeled probes. With the polymerase chain reaction technique we were able to amplify short segments of genes coding for coagulation factors VIII and IX. Electrophoretical analysis of products of polymerase chain reaction enabled us to detect deletions causing hemophilia A or B. To analyse deletions in dystrophin gene, the most frequent cause of Duchenne muscular dystrophy, we have amplified several different fragments of this gene simultaneously. We have studied restriction fragment length polymorphism closely linked to the cystic fibrosis locus with digoxigenin-deoxyuridine 5 -triphosphate labeled probe p3.11 with sensitivity comparable to methods involving the use of radioisotopes.

Cystic Fibrosis↗