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Validação de teste de reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) para detecção de aneuploidias fetais / Validation of quantitative fluorescent polymerase chain reaction (QF-PCR) test to detect fetal aneuploidiesMoraes, Renata Wendel de 14 December 2016 (has links)
A reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) é um método molecular de diagnóstico que se baseia na amplificação de pequenas sequências repetitivas do genoma (Short Tandem Repeats - STRs). Este método pode ser empregado para a detecção de aneuploidias durante a triagem pré-natal, porém, no Brasil, ainda não é utilizado nas instituições públicas. O objetivo do presente estudo foi avaliar a eficácia da QF-PCR em comparação com a citogenética na detecção de aneuploidias. Foram avaliadas 162 amostras de líquido amniótico de gestantes com risco fetal de aneuploidia aumentado. As amostras foram coletadas no Ambulatório de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O DNA fetal, para a análise do QF-PCR, foi extraído do líquido amniótico e foram utilizados 24 marcadores moleculares fluorescentes para a amplificação de genes presentes nos cromossomos 13, 18, 21, X e Y. A interpretação foi baseada na análise quantitativa dos fragmentos obtidos na amplificação. A análise citogenética foi realizada segundo metodologia convencional. A QF-PCR foi realizada às cegas, sem o conhecimento do resultado citogenético. A concordância entre os resultados obtidos pela citogenética e pela QF-PCR foi de 93,2% (151/162), com sensibilidade total de 90% e especificidade de 97,2%. Quando analisado apenas os resultados passíveis de detecção pela QF-PCR, sem os rearranjos, a concordância atinge 98,1% com sensibilidade de 98,7% e especificidade de 97,2%. O presente estudo demonstra que a QF-PCR é um método eficiente e confiável para triagem pré-natal de aneuploidias. Para a investigação de alterações cromossômicas estruturais a avaliação citogenética é necessária / Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular diagnostic method based on the amplification of short tandem repeats (STRs) present in genome. This method is widely used to detect aneuploidies in prenatal screening, but, in Brazil, it is not used in public services. We investigated the accuracy of QF-PCR for the prenatal recognition of common aneuploidies and compared these results with cytogenetic results in our laboratory. A total of 162 amniotic fluid samples of pregnancies with high risk of fetus aneuploid were collected at the Obstetric Ambulatory of Hospital das Clínicas - Universidade de São Paulo, São Paulo, Brazil. Fetal DNA was extracted and analyzed by multiplex QF-PCR kit, which contains 24 primer pairs located on chromosomes 13, 18, 21, X and Y. Cytogenetic analysis was performed based on conventional method. The results of cytogenetics test was not known while QF-PCR assay was performed. QF-PCR results were consistent with the results of cytogenetic analysis in 93.2% of all samples (151/162), with 90% total sensitivity and 97.2% specificity. When only possible results detected by QF-PCR are analyzed, without rearrangements samples, the agreement between both tests increases to 98.1%, with 98.7% sensitivity and 97.2% specificity. The present study demonstrates that QF-PCR was efficient and reliable for prenatal aneuploidy screening. This study suggests that QF-PCR can be used as a rapid diagnostic method; however, to structural chromosomal abnormalities cytogenetic analysis must be used
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A ativação da NADPH oxidase mediada pela superexpressão da Dissulfeto Isomerase proteica em células musculares lisas vasculares / Validation of quantitative fluorescent polymerase chain reaction (QF-PCR) test to detect fetal aneuploidiesGonçalves, Renata de Castro 14 December 2016 (has links)
A reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) é um método molecular de diagnóstico que se baseia na amplificação de pequenas sequências repetitivas do genoma (Short Tandem Repeats - STRs). Este método pode ser empregado para a detecção de aneuploidias durante a triagem pré-natal, porém, no Brasil, ainda não é utilizado nas instituições públicas. O objetivo do presente estudo foi avaliar a eficácia da QF-PCR em comparação com a citogenética na detecção de aneuploidias. Foram avaliadas 162 amostras de líquido amniótico de gestantes com risco fetal de aneuploidia aumentado. As amostras foram coletadas no Ambulatório de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O DNA fetal, para a análise do QF-PCR, foi extraído do líquido amniótico e foram utilizados 24 marcadores moleculares fluorescentes para a amplificação de genes presentes nos cromossomos 13, 18, 21, X e Y. A interpretação foi baseada na análise quantitativa dos fragmentos obtidos na amplificação. A análise citogenética foi realizada segundo metodologia convencional. A QF-PCR foi realizada às cegas, sem o conhecimento do resultado citogenético. A concordância entre os resultados obtidos pela citogenética e pela QF-PCR foi de 93,2% (151/162), com sensibilidade total de 90% e especificidade de 97,2%. Quando analisado apenas os resultados passíveis de detecção pela QF-PCR, sem os rearranjos, a concordância atinge 98,1% com sensibilidade de 98,7% e especificidade de 97,2%. O presente estudo demonstra que a QF-PCR é um método eficiente e confiável para triagem pré-natal de aneuploidias. Para a investigação de alterações cromossômicas estruturais a avaliação citogenética é necessária / Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular diagnostic method based on the amplification of short tandem repeats (STRs) present in genome. This method is widely used to detect aneuploidies in prenatal screening, but, in Brazil, it is not used in public services. We investigated the accuracy of QF-PCR for the prenatal recognition of common aneuploidies and compared these results with cytogenetic results in our laboratory. A total of 162 amniotic fluid samples of pregnancies with high risk of fetus aneuploid were collected at the Obstetric Ambulatory of Hospital das Clínicas - Universidade de São Paulo, São Paulo, Brazil. Fetal DNA was extracted and analyzed by multiplex QF-PCR kit, which contains 24 primer pairs located on chromosomes 13, 18, 21, X and Y. Cytogenetic analysis was performed based on conventional method. The results of cytogenetics test was not known while QF-PCR assay was performed. QF-PCR results were consistent with the results of cytogenetic analysis in 93.2% of all samples (151/162), with 90% total sensitivity and 97.2% specificity. When only possible results detected by QF-PCR are analyzed, without rearrangements samples, the agreement between both tests increases to 98.1%, with 98.7% sensitivity and 97.2% specificity. The present study demonstrates that QF-PCR was efficient and reliable for prenatal aneuploidy screening. This study suggests that QF-PCR can be used as a rapid diagnostic method; however, to structural chromosomal abnormalities cytogenetic analysis must be used
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Validação de teste de reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) para detecção de aneuploidias fetais / Validation of quantitative fluorescent polymerase chain reaction (QF-PCR) test to detect fetal aneuploidiesRenata Wendel de Moraes 14 December 2016 (has links)
A reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) é um método molecular de diagnóstico que se baseia na amplificação de pequenas sequências repetitivas do genoma (Short Tandem Repeats - STRs). Este método pode ser empregado para a detecção de aneuploidias durante a triagem pré-natal, porém, no Brasil, ainda não é utilizado nas instituições públicas. O objetivo do presente estudo foi avaliar a eficácia da QF-PCR em comparação com a citogenética na detecção de aneuploidias. Foram avaliadas 162 amostras de líquido amniótico de gestantes com risco fetal de aneuploidia aumentado. As amostras foram coletadas no Ambulatório de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O DNA fetal, para a análise do QF-PCR, foi extraído do líquido amniótico e foram utilizados 24 marcadores moleculares fluorescentes para a amplificação de genes presentes nos cromossomos 13, 18, 21, X e Y. A interpretação foi baseada na análise quantitativa dos fragmentos obtidos na amplificação. A análise citogenética foi realizada segundo metodologia convencional. A QF-PCR foi realizada às cegas, sem o conhecimento do resultado citogenético. A concordância entre os resultados obtidos pela citogenética e pela QF-PCR foi de 93,2% (151/162), com sensibilidade total de 90% e especificidade de 97,2%. Quando analisado apenas os resultados passíveis de detecção pela QF-PCR, sem os rearranjos, a concordância atinge 98,1% com sensibilidade de 98,7% e especificidade de 97,2%. O presente estudo demonstra que a QF-PCR é um método eficiente e confiável para triagem pré-natal de aneuploidias. Para a investigação de alterações cromossômicas estruturais a avaliação citogenética é necessária / Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular diagnostic method based on the amplification of short tandem repeats (STRs) present in genome. This method is widely used to detect aneuploidies in prenatal screening, but, in Brazil, it is not used in public services. We investigated the accuracy of QF-PCR for the prenatal recognition of common aneuploidies and compared these results with cytogenetic results in our laboratory. A total of 162 amniotic fluid samples of pregnancies with high risk of fetus aneuploid were collected at the Obstetric Ambulatory of Hospital das Clínicas - Universidade de São Paulo, São Paulo, Brazil. Fetal DNA was extracted and analyzed by multiplex QF-PCR kit, which contains 24 primer pairs located on chromosomes 13, 18, 21, X and Y. Cytogenetic analysis was performed based on conventional method. The results of cytogenetics test was not known while QF-PCR assay was performed. QF-PCR results were consistent with the results of cytogenetic analysis in 93.2% of all samples (151/162), with 90% total sensitivity and 97.2% specificity. When only possible results detected by QF-PCR are analyzed, without rearrangements samples, the agreement between both tests increases to 98.1%, with 98.7% sensitivity and 97.2% specificity. The present study demonstrates that QF-PCR was efficient and reliable for prenatal aneuploidy screening. This study suggests that QF-PCR can be used as a rapid diagnostic method; however, to structural chromosomal abnormalities cytogenetic analysis must be used
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Relação entre a medida da translucência nucal no primeiro trimestre e a presença de marcadores ultrassonográficos para a Síndrome de Down no segundo trimestre da gestação / Second trimester soft markers: relation to first trimester nuchal translucencyJavier Miguelez 25 May 2011 (has links)
A pesquisa de marcadores ultrassonográficos no segundo trimestre da gestação, após rastreamento combinado no primeiro, parece elevar substancialmente as taxas de detecção de Síndrome de Down, mas está amparada na assunção não comprovada de independência entre esses testes. O presente estudo investigou a relação entre a translucência nucal e uma série de marcadores ultrassonográficos no segundo trimestre. A medida da translucência nucal no primeiro trimestre era seguida pela realização da ultrassonografia morfológica entre 18 a 23 semanas e 6 dias de gestação, incluindo a pesquisa de três marcadores qualitativos (foco ecogênico intracardíaco, intestino hiperecogênico e defeito estrutural) e as medidas do osso nasal, da prega nucal, do comprimento do úmero, do comprimento do fêmur, do diâmetro anteroposterior das pelves renais e da espessura pré-nasal. Todas as variáveis contínuas foram expressas em múltiplos da mediana para a idade gestacional e os coeficientes de correlação entre a translucência nucal e essas variáveis (após transformação logarítmica) foram calculados. Em seguida, as frequências de marcadores clássicos no segundo trimestre, em casos com translucência nucal normal, foram comparadas àquelas com translucência nucal aumentada, usando pontos de corte definidos em múltiplos da mediana. Em população prospectiva de 1970 casos, a translucência nucal se correlacionou significativamente com todas as variáveis ultrassonográficas do segundo trimestre, em particular, com a prega nucal (r=0.10). Houve frequência significativamente maior de casos com prega nucal aumentada (10,7 versus 2,2%), definida como valor (em MoMs) acima do percentil 97,5, e intestino hiperecogênico (2,4% versus 0,1%) em casos com translucência nucal aumentada. Concluindo, a utilização de razões de verossimilhança baseadas na presença, ou ausência, de marcadores ultrassonográficos no segundo trimestre para modificar o risco calculado, no primeiro trimestre, poderia deteriorar a precisão das estimativas. Técnicas multivariadas por meio de marcadores ultrassonográficos quantitativos seriam opção mais adequada para a implantação de estratégias de rastreamento sequenciais / Genetic sonogram following first trimester combined screening appears to substantially increase detection rates for Down syndrome but it relies on the unproved assumption of independence between these tests. In this study we have investigated the relation of first trimester nuchal translucency to a series of secondtrimester soft markers. Nuchal translucency (NT) measurement in the first trimester was followed by second trimester scan (18-23w+6 days) including search for three categorical soft-markers (intracardiac echogenic foci, hyperechogenic bowel and structural defects) and measurements of nasal bone length, nuchal fold thickness, femur length, humerus length, renal pelvices diameter and prenasal thickness. All continuous variables were expressed in multiples of the medians for gestation (MoMs) and correlation coefficients between log-transformed NT and second trimester variables were calculated. In addition, frequencies of classical soft-markers in cases with increased NT were compared to those with normal NT, using MoMs cutoffs. In a dataset of 1970 cases, NT was significantly correlated (p<0.05) to all second trimester continuous variables, in particular to nuchal fold thickness (r=0.10). There was a higher frequency of cases with second trimester nuchal fold thickness above the 95th centile (10.7% versus 2.2%) and hyperechogenic bowel (2.4% versus 0.1%) in cases with increased NT. In conclusion, straightforward reassessment of risk using likelihood ratios derived from the classical genetic sonogram might lead to inaccurate estimates. Multivariate models using continuous second-trimester variables might be preferable in sequential screening strategies
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"Fenda facial diagnosticada no pré-natal: aspectos epidemiológicos, ultra-sonográficos e pós-natais" / Antenatally diagnosed facial cleft: epidemiologic, ultrasound and postnatal findingsMarcio José Rosa Requeijo 24 May 2006 (has links)
Noventa e sete fetos portadores de fenda facial diagnosticados entre Maio de 1995 e Novembro de 2004 foram avaliados no setor de medicina fetal da Clínica Obstétrica do Hospital das clinicas da universidade de São Paulo.Houve excelente correlação entre o tipo de fenda facial diagnosticada pela ultra-sonografia no período gestacional e o tipo de fenda facial observado no pós-natal. A avaliação do palato foi o maior problema técnico para o diagnóstico da fenda facial. A idade gestacional no diagnóstico da fenda facial foi tardia. Fetos com fenda facial isolada apresentaram excelente prognóstico e fetos com outras malformações apresentaram alta taxa de mortalidade independente de presença de aneuploidia / Ninety seven fetuses presenting facial cleft diagnosed from May 1995 to November 2004 at the Fetal Medicine Unit of the Obstetric Clinic at University of São Paulo Medical School Hospital were reviewed. An excellent correlation was found between the type of prenatally diagnosed cleft and the type of cleft observed after birth. Palate integrity evaluation was the main technical limitation of prenatal ultrasound. Diagnosis of the facial cleft occurred late in pregnancy in this series. Fetuses with isolated facial cleft had an excellent prognosis and fetus with other malformations presented very high mortality rate independently of the presence of chromosomal abnormality
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A ativação da NADPH oxidase mediada pela superexpressão da Dissulfeto Isomerase proteica em células musculares lisas vasculares / Validation of quantitative fluorescent polymerase chain reaction (QF-PCR) test to detect fetal aneuploidiesRenata de Castro Gonçalves 14 December 2016 (has links)
A reação em cadeia da polimerase fluorescente quantitativa (QF-PCR) é um método molecular de diagnóstico que se baseia na amplificação de pequenas sequências repetitivas do genoma (Short Tandem Repeats - STRs). Este método pode ser empregado para a detecção de aneuploidias durante a triagem pré-natal, porém, no Brasil, ainda não é utilizado nas instituições públicas. O objetivo do presente estudo foi avaliar a eficácia da QF-PCR em comparação com a citogenética na detecção de aneuploidias. Foram avaliadas 162 amostras de líquido amniótico de gestantes com risco fetal de aneuploidia aumentado. As amostras foram coletadas no Ambulatório de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O DNA fetal, para a análise do QF-PCR, foi extraído do líquido amniótico e foram utilizados 24 marcadores moleculares fluorescentes para a amplificação de genes presentes nos cromossomos 13, 18, 21, X e Y. A interpretação foi baseada na análise quantitativa dos fragmentos obtidos na amplificação. A análise citogenética foi realizada segundo metodologia convencional. A QF-PCR foi realizada às cegas, sem o conhecimento do resultado citogenético. A concordância entre os resultados obtidos pela citogenética e pela QF-PCR foi de 93,2% (151/162), com sensibilidade total de 90% e especificidade de 97,2%. Quando analisado apenas os resultados passíveis de detecção pela QF-PCR, sem os rearranjos, a concordância atinge 98,1% com sensibilidade de 98,7% e especificidade de 97,2%. O presente estudo demonstra que a QF-PCR é um método eficiente e confiável para triagem pré-natal de aneuploidias. Para a investigação de alterações cromossômicas estruturais a avaliação citogenética é necessária / Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular diagnostic method based on the amplification of short tandem repeats (STRs) present in genome. This method is widely used to detect aneuploidies in prenatal screening, but, in Brazil, it is not used in public services. We investigated the accuracy of QF-PCR for the prenatal recognition of common aneuploidies and compared these results with cytogenetic results in our laboratory. A total of 162 amniotic fluid samples of pregnancies with high risk of fetus aneuploid were collected at the Obstetric Ambulatory of Hospital das Clínicas - Universidade de São Paulo, São Paulo, Brazil. Fetal DNA was extracted and analyzed by multiplex QF-PCR kit, which contains 24 primer pairs located on chromosomes 13, 18, 21, X and Y. Cytogenetic analysis was performed based on conventional method. The results of cytogenetics test was not known while QF-PCR assay was performed. QF-PCR results were consistent with the results of cytogenetic analysis in 93.2% of all samples (151/162), with 90% total sensitivity and 97.2% specificity. When only possible results detected by QF-PCR are analyzed, without rearrangements samples, the agreement between both tests increases to 98.1%, with 98.7% sensitivity and 97.2% specificity. The present study demonstrates that QF-PCR was efficient and reliable for prenatal aneuploidy screening. This study suggests that QF-PCR can be used as a rapid diagnostic method; however, to structural chromosomal abnormalities cytogenetic analysis must be used
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Διερεύνηση των μηχανισμών με τους οποίους χημικές ενώσεις με αντινεοπλασματικές ιδιότητες προκαλούν γενετικές ανωμαλίες / Investigation of the mechanisms by which antineoplasmatic compounds induce genetic instabilityΕυθυμίου, Μαρία 26 August 2010 (has links)
Οι υπερίτες του αζώτου (nitrogen mustards) συνιστούν μία αποτελεσματική ομάδα φαρμάκων που χρησιμοποιούνται στη χημειοθεραπεία του καρκίνου. Πρόσφατα ευρήματα της ερευνητικής μας ομάδας έδειξαν ότι οι υπερίτες του αζώτου μελφαλάνη (MEL), χλωραμπουκίλη (CAB) και ο δραστικός της μεταβολίτης, το PHE, επιδεικνύουν ισχυρή θραυσματογόνο δράση, αλλά επιπρόσθετα, εμφανίζουν ανευπλοειδογόνο δράση, διαταράσσοντας το χρωμοσωματικό αποχωρισμό μέσω τροποποιήσεων της δομής και λειτουργίας της μιτωτικής συσκευής. Στην παρούσα διατριβή, διερευνήθηκε περαιτέρω ο μηχανισμός της ανευπλοειδογόνου δράσης των παραπάνω δραστικών ενώσεων και πραγματοποιήθηκε σύγκριση της γενετικής δράσης δύο νέων στεροειδών αναλόγων του PHE, τα ανάλογα ΕΑ-92 και ΕΑ-97 με αυτήν των MEL, CAB και PHE. Τα στεροειδή ανάλογα σχεδιάστηκαν με στόχο την αύξηση της εκλεκτικότητας της αντινεοπλασματικής δράσης.
Η ικανότητα των MEL, CAB και PHE να προκαλούν φαινόμενα χρωμοσωματικής καθυστέρησης μελετήθηκε σε σύγκριση με τα στεροειδή ανάλογα ΕΑ-92 και ΕΑ-97. Η μελέτη πραγματοποιήθηκε σε ανθρώπινα λεμφοκύτταρα in vitro με τη μέθοδο αναστολής της κυτταροκίνησης (CBMN) σε συνδυασμό με τη μέθοδο FISH και τη χρήση πανκεντρομερικού ανιχνευτή. Επιβεβαιώθηκε η θραυσματογόνος και ανευπλοειδογόνος δράση των ενώσεων MEL, CAB και PHE, ενώ φάνηκε ότι τα στεροειδή ανάλογα ΕΑ-92 και ΕΑ-97 προκαλούν αποκλειστικά χρωμοσωματική θραύση. Το φαινόμενο της χρωμοσωματικής καθυστέρησης μελετήθηκε επίσης με τη μέθοδο CREST στην κυτταρική σειρά ποντικού C2C12. Με τη μέθοδο αυτή, επιβεβαιώθηκε η διπλή γενετική δράση των ενώσεων MEL, CAB και PHE. Τα στεροειδή ανάλογα ΕΑ-92 και ΕΑ-97 εμφανίστηκαν ως οι ηπιότεροι επαγωγείς ΜΝ και προκαλούν κυρίως χρωμοσωματική θραύση, ενώ ήπια ανευπλοειδογόνο δράση παρουσίασε μόνο το ανάλογο ΕΑ-92. Ακολούθως, εξετάσθηκε η ικανότητα των υπό εξέταση χημικών ενώσεων ΕΑ-92 και ΕΑ-97, να επηρεάζουν τη δομή και λειτουργία της μιτωτικής συσκευής σε σχέση με αυτήν των ενώσεων MEL, CAB, PHE, με διπλό ανοσοφθορισμό για τη β- και γ-τουμπουλίνη. Παρατηρήθηκε ότι όλες οι ενώσεις, εκτός από το στεροειδές ΕΑ-97 προκαλούν τη δημιουργία πολυπολικών μεταφάσεων, ενώ όλες οι ενώσεις επάγουν το σχηματισμό μεσοφασικών κυττάρων με ανώμαλο αριθμό κεντροσωμάτων. Όλες οι υπό εξέταση χημικές ενώσεις εμφανίζουν κυτταροτοξικότητα και καθυστέρηση του κυτταρικού κύκλου σε καλλιέργειες ανθρώπινων λεμφοκυττάρων και στα κύτταρα ποντικού C2C12.
Στη συνέχεια διερευνήθηκε η ικανότητα των υπό εξέταση ενώσεων να επάγουν την απόπτωση και μελετήθηκε ο ρόλος της απόπτωσης στην εκδήλωση της γενετικής δράσης των ενώσεων MEL, CAB και PHE. Η μελέτη αυτή πραγματοποιήθηκε στα κύτταρα C2C12 με τη μέθοδο της διπλής χρώσης Αννεξίνης V/Ιωδιούχου προπιδίου και το διπλό ανοσοφθορισμό β- και γ-τουμπουλίνης, ανεξάρτητα, σε κύτταρα ποντικού C2C12, παρουσία του γενικού αναστολέα της δράσης των κασπασών, Z-VAD-FMK, αλλά και αναστολέων της δράσης συγκεκριμένων κασπασών. Όλες οι υπό εξέταση ενώσεις επάγουν χαμηλά ποσοστά απόπτωσης. Οι κασπάσες-3, -6 και -8 συμμετέχουν στην επαγόμενη από τη MEL απόπτωση αλλά δεν συμμετέχουν στην απομάκρυνση των κυττάρων με μικροπυρήνες που επάγονται από τη δράση της ίδιας ένωσης. Η απόπτωση αποτελεί μηχανισμό απομάκρυνσης των κυττάρων με μικροπυρήνες και κανονικό κεντροσωματικό αριθμό που επάγονται από τις ενώσεις MEL, CAB και PHE. Αντίθετα, τα κύτταρα με υπεράριθμα κεντροσώματα, που προκύπτουν από τη δράση των παραπάνω ενώσεων δεν απομακρύνονται μέσω απόπτωσης.
Για την περαιτέρω διερεύνηση του μηχανισμού με τον οποίο οι δραστικές ενώσεις MEL και CAB εκφράζουν τις ανευπλοειδογόνες ιδιότητες τους, μελετήθηκε η επίδραση τους στην έκφραση των πρωτεϊνών Aurora-B, survivin, Aurora-A και γ-τουμπουλίνη σε κύτταρα ποντικού C2C12, με τη μέθοδο της ανοσοαποτύπωσης των πρωτεϊνών. Παράλληλα μελετήθηκε η ένωση ΕΑ-97, η οποία σύμφωνα με τα ευρήματα μας, εμφάνισε αποκλειστικά θραυσματογόνο δράση. Οι ενώσεις MEL και CAB, εκδηλώνουν τις ανευπλοειδογόνες ιδιότητες τους προκαλώντας μείωση της έκφρασης των πρωτεϊνών Aurora-B και survivin και επάγοντας την αύξηση της έκφρασης της πρωτεΐνης Aurora-A. Επιπρόσθετα, η ένωση MEL, προκαλεί αύξηση της έκφρασης της γ-τουμπουλίνης. Τα ευρήματα αυτά υποδεικνύουν τη συμμετοχή των παραπάνω πρωτεϊνών στην εκδήλωση της ανευπλοειδογόνου δράσης των ενώσεων που μελετήθηκαν. Αντίθετα το στεροειδές ανάλογο ΕΑ-97 που εμφανίζει αποκλειστικά θραυσματογόνο δράση, δεν μεταβάλλει την έκφραση των παραπάνω πρωτεϊνών. / Nitrogen mustards represent an effective class of drugs that are used in chemotherapy. Recent findings of our group have shown that nitrogen mustard analogues, melphalan (MEL), chlorambucil (CAB) and PHE, in addition to their clastogenic activity, they exert their aneugenic potential by affecting chromosome segregation due to modifications of mitotic apparatus. In the present study, we investigated the mechanism by which the above compounds display their aneugenicity in comparison with two new steroidal analogues of PHE, EA-92 and EA-97, which were designed aiming at most effective antineoplasmatic activity.
The ability of MEL, CAB and PHE to induce chromosome delay events was studied in comparison with the steroidal analogues EA-92 and EA-97. The mechanism of micronucleation was determined by Cytokinesis Block Micronucleus assay (CBMN assay) in combination with Fluorescence In Situ Hybridization (FISH) using pancentromeric DNA probe. It was confirmed that MEL, CAB and PHE generated MNi by two mechanisms, chromosome breakage and chromosome delay, while EA-92 and EA-97 induced the formation of MN originated exclusively from chromosome breakage events. The ability of the tested compounds to induce chromosome delay was also investigated in C2C12 mouse cells by CREST analysis. The dual genetic activity of MEL, CAB, and PHE was confirmed in a different biological system. The analogues EA-92 and EA-97 appeared as weaker MN inducers and they induced mainly chromosome breakage, while a weak aneugenic activity was observed for EA-92. The ability of the nitrogen mustard analogues to affect the organization of mitotic apparatus was investigated in comparison with MEL, CAB and PHE by double immunofluorescence of β- and γ-tubulin in C2C12 mouse cells. It was observed that all compounds, except EA-97, induced mutlipolar metaphases, and also generated interphase cells with abnormal centrosome number. All compounds displayed increased cytotoxicity and they caused cell cycle delay in human lymphocyte cultures and in C2C12 mouse cells.
The ability of the tested compounds to induce apoptosis was studied by Annexin V/PI assay. It was revealed that all compounds induced apoptosis. The effect of apoptosis on the genetic activity of MEL, CAB and PHE was investigated by inhibition of apoptosis in the presence of the inhibitor Z-VAD-FMK and the use of specific inhibitors for caspase -3, -6, -8 and -1. For this reason Annexin V/PI assay and double immunofluorescence of β- and γ-tubulin were performed, independently in C2C12 mouse cells. Caspases -3, -6 and -8 are involved in melphalan-induced apoptosis, but they are not involved in the elimination of cells in the presence of melphalan. Apoptosis is the responsible mechanism for the exclusion of cells with MNi and normal centrosome number that are induced by MEL, CAB and PHE. On the contrary, cells exerting supernumerary centrosomes are not eliminated by apoptosis in the presence of the above compounds.
To further elucidate the mechanisms by which MEL and CAB exert their aneugenic potential, we examined the ability of the compounds to alter the expression of proteins having important role in chromosome segregation, such as the proteins Aurora-B, survivin, Aurora-A and γ-tubulin. The analysis was performed by Western blot method in C2C12 mouse cells. We also studied the steroid analogue EA-97, which according to our findings acts as a pure clastogen and do not exert aneugenic potential as opposed to MEL and CAB. MEL and CAB exert their aneugenic potential by the reduction of Aurora-B and survivin expression and by enhancing the expression of Aurora-A. γ-tubulin was upregulated in the presence of MEL. These findings show the implication of these proteins in chromosome delay events induced by MEL and CAB. On the other hand, the analogue EA-97 did not affect the expression of the above proteins.
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Nové ultrazvukové markery aneuploidií v prvém trimestru gravidity / New Aneuploidy Ultrasound Markers in First Trimester of PregnancyBřešťák, Miroslav January 2015 (has links)
Prenatal diagnostics is headed in several directions - towards visualization of fetuses and biochemical, cytogenetic and molecular genetic diagnostics in laboratories. Whereas visualization of fetuses does not a priori represent any direct risk for pregnancy and does not increase the number of potential pregnancy complications, this is not always the case with the laboratory testing. There are known risks connected with invasive methods of prenatal diagnostics. The number of potential unintentional pregnancy complications and losses as well as the technical and economic aspects of invasive prenatal diagnostics lead to attempts of identifying ways of detecting any potentially affected individuals by screening methods, thus minimizing the undesirable impact of invasive diagnostics on the pregnant population. The more precise the selective criteria, the lesser the number of pregnant women exposed to invasive exams. Another way of decreasing the number of unintentional complications in relation to invasive diagnostics is to simplify and improve the fetal samples harvesting methods during pregnancy. The work primarily focused on two areas: Determination of the relation between fraction shortening of the left and right ventricles and a fetal chromosomal complement, and verification of reliability of a new method...
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Molekulárně genetická charakterizace vzácných nádorů urogenitálního traktu. / Molecular genetic characterization of the rare tumours of the urogenital tract.Šteiner, Petr January 2011 (has links)
The aim of this study was molecular characterization of four types of renal tumours (papillary renal cell carcinoma [PRCC], tubulocystic renal carcinoma [TCRC], pseudorossette forming renal carcinoma [PRRC] and unclassified renal carcinomas [URC]) and two types of rare tumours of the testes (Adult type of granulosa cell tumours [ATGCTs] and Incompletely differentiated sex cord stromal tumours [ISCSTs]). In case of TCRC the activity of signalling pathways involved in angiogenesis was studied. The aim was to determine the suitability of antiangiogenic agents for treatment of TCRC. Next, the methylation profile of 24 tumor suppressor genes was studied in TCRC and PRCC in order to analyze their similarity. Eventual differences could be helpful tool in differential diagnostics. Also, spectrum of chromosomal aberrations was analyzed by array-CGH in one case of PRRC and two cases of URC. Any unique aberration found would be useful in differential diagnostics of these tumors. Last, but not least, the specificity of mutation c.402C>G of FOXL2 gene for ovarian ATGCTs was verified by studying its occurrence in testicular ATGCTs and ISCSTs. Analysis of mRNA levels did not reveal any enhanced activity of the studied signalling pathways. Cluster analysis of methylation profiles showed close relationship between PRCC a...
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Nové ultrazvukové markery aneuploidií v prvém trimestru gravidity / New Aneuploidy Ultrasound Markers in First Trimester of PregnancyBřešťák, Miroslav January 2015 (has links)
Prenatal diagnostics is headed in several directions - towards visualization of fetuses and biochemical, cytogenetic and molecular genetic diagnostics in laboratories. Whereas visualization of fetuses does not a priori represent any direct risk for pregnancy and does not increase the number of potential pregnancy complications, this is not always the case with the laboratory testing. There are known risks connected with invasive methods of prenatal diagnostics. The number of potential unintentional pregnancy complications and losses as well as the technical and economic aspects of invasive prenatal diagnostics lead to attempts of identifying ways of detecting any potentially affected individuals by screening methods, thus minimizing the undesirable impact of invasive diagnostics on the pregnant population. The more precise the selective criteria, the lesser the number of pregnant women exposed to invasive exams. Another way of decreasing the number of unintentional complications in relation to invasive diagnostics is to simplify and improve the fetal samples harvesting methods during pregnancy. The work primarily focused on two areas: Determination of the relation between fraction shortening of the left and right ventricles and a fetal chromosomal complement, and verification of reliability of a new method...
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