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Content available remote Doping in Sport: New Developments
Gene doping is defined by the World Anti-Doping Agency (WADA) as "the non-therapeutic use of genes, genetic elements and/or cells that have the capacity to enhance athletic performance." The rapid development of molecular biology has enabled not only treatment of many diseases, but also improvement of athletes' fitness. Gene therapy methods can be used to modify the athlete's body by inserting genes into the target tissue. It is very possible that in near future, many genes will be used in gene doping, e.g. erythropoietin, growth hormone, insulin-like growth hormone and vascular endothelial growth factor. Functional tests conducted by many independent laboratories proved that products of these genes exert a crucial influence on the body's adaptation to exercise. The risk of gene doping is enormous. Gene therapy is currently in the phase of clinical tests so it is impossible to predict what kind of side effects it may produce. Studies on animal models showed that the uncontrolled transgene expression and insertional mutagenesis can even lead to death. At present the detection of gene doping is very difficult for a variety of reasons. The main problem is the identification of the transgene and endogenously produced protein. The only possible detection is the biopsy of the target tissue, where the exogenous genes were inserted.
Purpose. The aim of this study was to search for single nucleotide changes in the P1 promoter sequence of the IGF1 gene in both high-class athletes and subjects who do not participate in professional sports. The second rationale was to compare the polymorphism frequency in the promoter region in athletes across a variety of sport disciplines. Methods. 272 athletes from the regional sports team of Wielkopolska (Poland) took part in the study. 154 athletes practiced team sports whereas 118 trained in strength sports. The control group comprised of 122 individuals who did not practice sport professionally. Genetic material came from epithelium swabs from the oral cavity, which was then subject to DNA isolation and tested with the PCR/SSCP technique. DNA samples showing different migration in electrophoresis were then sequenced. Results. The frequency of the polymorphisms was substantially higher (p < 0.05) in the athlete group (9.2%) than in the control group (2.4%). A considerably higher frequency of the sequence changes (p < 0.05%) was observed in those athletes who participated in strength sports (11.0%) than in team sports (7.8%). Among all the individuals tested, the -147bp -475bp region was the most polymorphic, yet changes within this fragment were not detected in the control group. In the control group the most often change in the nucleotide sequence was observed at position -1089 (T/C), while in the athlete group at position -383 (C/T). Change at position -1089 (T/C), found in eight individuals, is related to a potential binding site of the AP-1 transcription factor. Change at position -361 (G/A), detected in two individuals, is probably the site for the Sp1 transcription factor. Conclusion. The conducted study found that single nucleotide polymorphism of the P1 promoter region of the IGF1 gene is more frequent in athletes than in non-athletes. We believe that the variation in the P1 promoter sequence of this gene is related to an organism's adaptation to physical (especially strength) activity.
Human papillomavirus (HPV) infection is a major risk factor for the development of cervical cancer. The HPV-induced immortalization of epithelial cell usually requires integration of the viral DNA into the host cell genome. The integration event causes disruption of the E2 gene and this is followed by overexpression of the E6 and E7 oncoproteins. The E2 protein is a transcription factor that regulates expression of the E6 and E7 oncoproteins by binding to four sites within the viral long control region. We used an in vitro cell culture model to explore the role of the E2 protein in the transcriptional control of the HPV16 long control region. Employing transient and stable transfection experiments we simulated the episomal and integrated states of the viral genome, respectively. We show that the E2 protein up-regulates E6/E7 transcription from episomal DNA but represses it in the case of integrated DNA. The activator function of the E2 protein seems to counteract the repressive chromatin structure formed over episomal DNA. Steroid hormones and retinol also modulate oncogene transcription differently depending on the physical structure of the viral DNA. Our data suggest regulatory mechanisms involving interactions between the E2 protein and nuclear hormone receptors.
Content available remote Comparative biochemical analysis of lectin and nuclease from Chelidonium majus L.
It has been recently recognized that lectins exhibit other activities besides hemagglutination. Previously we have found that purified lectin from Chelidonium majus showed DNase activity (Fik, Goździcka-Józefiak & Kędzia, 1995, Herba Polon. 41, 84-95). Comparison of lectin and DNase from the sap from leaves and roots of Chelidonium majus proved that both these compounds are composed of 24 kDa monomer subunits which have an identical N-terminal sequence but differ in amino-acid composition and degree of glycosylation. Possible interrelationship between lectin and DNase is discussed.
Introduction: Retinoids are essential for the maintenance of epithelial differentiation and play a fundamental role in chemoprevention of epithelial carcinogenesis. Retinoids exert their biological functions through nuclear receptors, retinoic acid receptor (RAR) and retinoid X receptor (RXR). The present study made an effort to analyze serum blood concentration of retinoids in women with cervical cancer as well as to assess an expression of RARs and RXRs in postoperative cervical cancer tissues HPV 16/18 positive. Material and methods: The study material included tissue samples of 42 squamous cell carcinoma, 7 samples of adenocarcinoma cervix uteri and 26 samples carcinoma in situ. The assessment of serum level of retinol, expression of retinoid receptors and presence of HPVs genome was performed. Results and conclusions: The mean retinol content in blood serum of patients with cervical cancer associated with HPV infection type 16 and/or 18 was lower than in controls. The level of RARα, RARβ and RXRβ mRNA expression was significantly decreased in the study group of women with CIS, squamous cell carcinoma and adenocarcinoma cervix to compare morphologically to the control women. In squamous cell carcinoma and carcinoma in situ were found to exhibit a decreased expression of RARα by about 75%, RARβ by 90%, RXRβ by 70% and 83% respectively compared to the control tissues. Among adenocarcinomas RARα, RARβ, RXRβ were expressed in 10%. In the study cancer tissues RARγ, RXRα and RXRγ were expressed on the same level as in the control tissues.
Wprowadzenie: Retinoidy są ważnymi czynnikami biorącymi udział w regulacji różnicowania i proliferacji komórek nabłonkowych, a także odgrywają ważną rolę w ich chemioprofilaktyce i nowotworzeniu. Retinoidy wywierają swój efekt biologiczny poprzez receptory jądrowe RAR i RXR. Cel pracy: Celem przeprowadzonych badań była analiza stężenia retinolu w surowicy krwi kobiet z rakiem szyjki macicy oraz ocena ekspresji mRNA RAR i RXR w komórkach raka szyjki macicy zakażonych wirusem brodawczaka ludzkiego (HPV) typu 16. i 18. Materiał i metoda: Materiał badany obejmował 42 skrawki pooperacyjne tkanek raka płaskonabłonkowego, 7 skrawków gruczolakoraka szyjki macicy, a także 26 skrawków raka przedinwazyjnego. U osób, od których pochodziły skrawki tkanek, oceniono surowiczy poziom retinolu, a w tkankach ekspresję receptorów retinoidowych na poziomie mRNA i obecność sekwencji genomu HPV z zastosowaniem technik PCR. Wyniki i wnioski: Średnia zawartość retinolu w surowicy krwi pacjentek z rakiem szyjki macicy z towarzyszącym zakażeniem wirusem HPV typu 16. i 18. była niższa niż w grupie kontrolnej, ale nie znamienna statystycznie. Poziom RARα, RARβ oraz ekspresja mRNA dla RXRβ były znamiennie niższe w grupie badanej – u pacjentek z rakiem przedinwazyjnym (CIS), z rakiem płaskonabłonkowym i z gruczolakorakiem szyjki macicy, w porównaniu z kobietami z grupy kontrolnej. W przypadku raka płaskonabłonkowego i raka przedinwazyjnego stwierdzono zmniejszenie ekspresji RARα mniej więcej o 75%, RARβ o 90%, a RXRβ odpowiednio o 70% i 83% w porównaniu z komórkami tkanek kontrolnych. W przypadku gruczolakoraków ekspresja RARγ, RXRα and RXRγ była na poziomie takim jak w tkankach grupy kontrolnej.
Content available remote Chloroplast-specific leucine tRNAs from wheat
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