63,483 research outputs found
Vitrification of mammalian spermatozoa in the absence of cryoprotectants: from past practical difficulties to present success
No full textDNA integrity and motility of human spermatozoa after standard slow freezing versus cryoprotectant-free vitrification
No full textAbstract
BACKGROUND:
In contrast to the technique of conventional freezing, the vitrification of spermatozoa requires high cooling rates (720 000 degrees K/min), which could be damaging for spermatozoa. The aim of our study was to compare slowly frozen and vitrified spermatozoa in terms of their post-thaw DNA integrity and motility.
METHODS:
Semen samples were prepared according to the routine swim-up technique and divided into aliquots for comparison of fresh, conventionally frozen and vitrified spermatozoa from the same ejaculate in the presence or absence of cryoprotectants. Spermatozoa motility and DNA integrity were determined.
RESULTS:
The motility of spermatozoa conventionally (slowly) frozen with a cryoprotectant was similar to that recorded for spermatozoa vitrified in the absence of cryoprotectant (47 versus 52%). The DNA integrity was unaffected by the cryopreservation method or presence of cryoprotectants.
CONCLUSION:
The vitrification of human spermatozoa in the absence of conventional cryoprotectants is indeed feasible. The DNA integrity of vitrified sperm is comparable with that shown by standard slow-frozen/thawed spermatozoa, yet the method is quick and simple and does not require special cryobiological equipment
Cryoprotectant-free cryopreservation of human spermatozoa by vitrification and freezing in vapor: effect on motility, DNA integrity, and fertilization ability
No full textAbstract
Human spermatozoa can be successfully cryopreserved avoiding the use of cryoprotectants through vitrification at very high cooling rates (up to 7.2 x 10(5) degrees C/min). This is achieved by directly plunging a copper cryoloop loaded with a sperm suspension into liquid nitrogen. After storage, vitrified spermatozoa are instantly thawed by melting in an agitated, warm medium. The goal of the present study was to compare the quality of spermatozoa cryopreserved using this rapid vitrification method with that of spermatozoa cooled relatively slowly by preexposure of the loaded cryoloop to liquid nitrogen vapor (-160 degrees C) with speed in the range 150-250 degrees C/min) before immersion into liquid nitrogen. Both cooling modes led to comparable results in terms of the motility, fertilization ability, and DNA integrity of the warmed spermatozoa. In both cases, instant thawing by melting in a warm medium was essential for successful cryopreservation. Our findings suggest that optimal regimes for the cryoprotectant-free cryopreservation of spermatozoa need not be restricted to very fast cooling before storage in liquid nitrogen, a wide range of cooling rates being acceptable. Herein, we discuss the implications of this finding in the light of the physics of extra- and intracellular vitrification
Die Werteerziehung im Lehrwerk Johannes Pauls II.
No full textAn in‑depth analysis of writings of John Paul II leads to a conclusion that the Pope cared for upbringing that would foster to values. He clearly indicated that the person is to be viewed as the foundation of the process of upbringing and also stressed the significance of upbringing towards life in the family, nation and Church. The author of this article accounts for and presents the problem of upbringing towards values, which is interpreted from the teachings of John Paul II. First, the author indicates the complementary character of education, religion and faith, then they are oriented towards the world of values and the Christian hierarchization of these values
Angiotensin II induces soluble fms-Like tyrosine kinase-1 release via calcineurin signaling pathway in pregnancy
No full textMaternal endothelial dysfunction in preeclampsia is associated with increased soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating antagonist of vascular endothelial growth factor and placental growth factor. Angiotensin II (Ang II) is a potent vasoconstrictor that increases concomitant with sFlt-1 during pregnancy. Therefore, we speculated that Ang II may promote the expression of sFlt-1 in pregnancy. Here we report that infusion of Ang II significantly increases circulating levels of sFlt-1 in pregnant mice, thereby demonstrating that Ang II is a regulator of sFlt-1 secretion in vivo. Furthermore, Ang II stimulated sFlt-1 production in a dose- and time-dependent manner from human villous explants and cultured trophoblasts but not from endothelial cells, suggesting that trophoblasts are the primary source of sFlt-1 during pregnancy. As expected, Ang II-induced sFlt-1 secretion resulted in the inhibition of endothelial cell migration and in vitro tube formation. In vitro and in vivo studies with losartan, small interfering RNA specific for calcineurin and FK506 demonstrated that Ang II-mediated sFlt-1 release was via Ang II type 1 receptor activation and calcineurin signaling, respectively. These findings reveal a previously unrecognized regulatory role for Ang II on sFlt-1 expression in murine and human pregnancy and suggest that elevated sFlt-1 levels in preeclampsia may be caused by a dysregulation of the local renin/angiotensin system
Święty Jan Paweł II o duchowości laikatu
No full textThe author of this article shows input of saint John Paul II in the understanding of spirituality of lay people. The article proves that the papal teaching about the laity is a continuation of the teaching of The Second Vatican Council and also brings some new elements. The particular attention paid to the communion dimension of the Church should be emphasized. The author also discusses the participation of lay people in the threefold office of the Christ, incarnational dimension of the lay spirituality and the question of the common call to sanctity.Autor artykułu ukazuje wkład św. Jana Pawła II w rozumienie duchowości ludzi świeckich. Udowadnia, że nauczanie papieża na temat laikatu stanowi kontynuację nauczania Soboru Watykańskiego II, ale wnosi też nowe akcenty. Na podkreślenie zasługuje szczególny akcent położony na komunijny wymiar Kościoła. Autor omawia też udział świeckich w potrójnym urzędzie Chrystusa, inkarnacyjny wymiar duchowości laikatu i kwestię powszechnego powołania do świętości
Święty Jan Paweł II o duchowości chrześcijańskiego Wschodu
No full textThe author of the article shows the major themes of the teaching of Saint John Paul II on Eastern Christian spirituality. He indicates the pope’s personal interest in the culture, especially philosophy and art developed in the orthodox environment. The article also presents the pope’s ecumenical efforts and the related difficulties. On the broader theological basis the author elaborates the most important elements of the orthodox spirituality, which the Slavic pope pointed out during his long pontificate.Autor artykułu ukazuje główne linie nauczania św. Jana Pawła II na temat duchowości chrześcijańskiego Wschodu. Wskazuje na osobiste zainteresowania papieża kulturą, zwłaszcza filozofią i sztuką rozwijaną w kręgu prawosławia. Ukazuje również wysiłki ekumeniczne i związane z nimi trudności. Na szerszym fundamencie teologicznym autor rozwija główne elementy duchowości prawosławnej, na jakie zwracał uwagę słowiański papież w czasie swego długiego pontyfikatu
Rola cudu w apologetyce przed II soborem watykańskim. Refleksja na podstawie analizy ówczesnych podręczników akademickich
No full textIn this article, the author made a reflection on the role of miracle in apologetics lecture before The Second Vatican Council. Looking for answers to this question, firstly the author presented the teaching of The First Vatican Council on miracle and its role. Then he analyzed several Polish academic textbooks of apologetics that had appeared before The Second Vatican Council in order to examine the function of miracle in relation to the Revelation.W niniejszym artykule autor podjął refleksję nad tym, jaka była rola cudu w wykładzie podręcznikowym apologetyki przed Vaticanum II. Szukając odpowiedzi na to pytanie, najpierw przedstawił nauczanie I Soboru Watykańskiego na temat cudu i jego roli. Następnie poddał analizie kilka polskojęzycznych podręczników akademickich do apologetyki, jakie pojawiły się przed II soborem watykańskim, aby zbadać w nich funkcję cudu w relacji do Objawienia
Uniwersytecka „melodia”. Tarnowski przyczynek do współpracy międzynarodowej Uniwersytetu Papieskiego Jana Pawła II w Krakowie
No full textThe Erasmus exchange programme is one of the greatest culture and education programs, which helps students, teachers and administrative staff to explore and to grow their potential. Programme offers a chance to gain professional development through studying, teaching or training in a partner Higher Education Institution in Europe. Nine students and ten academic teachers from the Faculty of Theology, Section in Tarnow of the Pontifical University of John Paul II in Krakow have participated in programme since 2007. The author of this article presents contribution of the Faculty of Theology, Section in Tarnow to the international cooperation and development of the Pontifical University of John Paul II in Krakow.The Erasmus exchange programme is one of the greatest culture and education programs, which helps students, teachers and administrative staff to explore and to grow their potential. Programme offers a chance to gain professional development through studying, teaching or training in a partner Higher Education Institution in Europe. Nine students and ten academic teachers from the Faculty of Theology, Section in Tarnow of the Pontifical University of John Paul II in Krakow have participated in programme since 2007. The author of this article presents contribution of the Faculty of Theology, Section in Tarnow to the international cooperation and development of the Pontifical University of John Paul II in Krakow
Clean technique for cryoprotectant-free vitrification of human spermatozoa
No full textHuman spermatozoa can be successfully cryopreserved without the use of cryoprotectants through vitrification at very high warming rates. This is achieved by plunging a small amount of frozen sperm suspension into a warming medium, or a large amount of sperm suspension into an agitated warming medium. The aim of the present study was to compare the motility of human spermatozoa cryopreserved using four different methodologies of cooling and warming: cryoloops, droplets, open-pulled straws and standard open straws. Evaluation of two parameters, motility and viability rate of spermatozoa, suggests that all four methods are suitable for use in assisted reproductive technology. However, only the use of open-pulled straws as well as standard open straws allows the isolation of spermatozoa from liquid nitrogen with low potential risk of microbial contamination during freezing and storage, and is thereby a clean method of vitrification
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