Search

Your search keyword '"Niżański, Wojciech"' showing total 403 results
Start Over Author "Niżański, Wojciech"
403 results on '"Niżański, Wojciech"'

29. Cat presumptive zygotes assessment in relation to their development.

Author

Kij-Mitka, Barbara, Gabryś, Julia, Kochan, Joanna, Nowak, Agnieszka, Szmatoła, Tomasz, Prochowska, Sylwia, Niżański, Wojciech, and Bugno-Poniewierska, Monika

Subjects
ZYGOTES, ZONA pellucida, CATS, OVUM, CAT diseases, BLASTOCYST
Abstract

The evaluation of oocytes and zygotes, based on their size, shape and morphology, is a valuable tool for predicting subsequent embryo development. While this assessment is non-invasive and made possible with time-lapse monitoring systems, not all the assessment criteria used for zygotes with pale cytoplasm can be used for domestic cat zygotes, which have dark cytoplasm. In this study, feline presumptive zygotes were evaluated for shape, size, and morphology. Measurements were also made of the diameter of the entire zygote, its cytoplasm, and the zona pellucida. Differences in the dataset were assessed using the generalized linear model (GLM) procedure. While there was no relationship between a combination of the tested parameters with the potential for cleavage, blastocyst development, and hatching, the parameters of the shape and size of the entire oocyte, and of the zona pellucida, were related to the development potential. The results presented in this study indicate that the assessment procedure for human zygotes has to be adjusted to be used in the cat model, however the relationship between measurements of the diameter of presumptive feline zygotes and the thickness of zona pellucida with their developmental potential deserves further investigation to optimize assessment of cat presumptive zygotes. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

32. ARTs in wild felid conservation programmes in Poland and in the world

Author

Kochan Joanna, Niżański Wojciech, Moreira Nei, Cubas Zalmir Silvino, Nowak Agnieszka, Prochowska Sylwia, Partyka Agnieszka, Młodawska Wiesława, and Skotnicki Józef

Subjects
wild felids, assisted reproduction technology, conservation, biodiversity, Veterinary medicine, SF600-1100
Abstract

With the exception of the domestic cat, all felid species (Felidae) are currently threatened with extinction in their natural habitat. To develop effective and optimal wild cat conservation programmes with assisted reproductive technology (ART) it is necessary to combine advances from different disciplines of science, starting from the biology of the species, through research into the population and habitat, assisted reproductive technologies, establishment of gene banks, developing bioinformatic systems, and ending with biodiversity and endangered species management. In the last few years knowledge of felid reproduction has expanded considerably thanks to comparative studies utilising the domestic cat as a research model for endangered wild cats. Basic reproductive techniques utilised in both domestic cat breeding and rescuing wild felid populations that are threatened with extinction include semen collection and cryopreservation, artificial insemination, oocyte collection, in vitro maturation, in vitro fertilisation, somatic cloning, and embryo transfer. The main directions in which assisted reproductive technologies are being developed in wild cat conservation implementations and the contribution of Polish research centres in advancing these methods are presented.

Published
2019
Full Text
View/download PDF

40. Effect of serum starvation and contact inhibition on dermal fibroblast cell cycle synchronization in two species of wild felids and domestic cat

Author

Młodawska, Wiesława, Mrowiec, Patrycja, Bochenek, Michał, Wnęk, Katarzyna, Kochan, Joanna, Nowak, Agnieszka, Niżański, Wojciech, Prochowska, Sylwia, and Pałys, Marcin

Subjects
contact inhibition, fibroblasts, cell cycle, feline, serum starvation
Abstract

Cell cycle synchronization of donor cells is an important step in mammalian somatic cell nuclear transfer (SCNT). This study was designed to compare the efficiency of serum starvation (Ss) and contact inhibition (cI) on cell cycle synchronization of jaguarundi, manul, and domestic cat skin fibroblasts, in the production of G0/G1 cells suitable for SCNT in felids. Ss was performed after the growing (G) cells reached 40–50% (G50+Ss), 60–70% (G70+Ss) and full confluency (Fc), i.e. in association with cI (cI+Ss). Frozen-thawed cells were cultured to the given state of confluency (d0; controls), and subjected to Ss or cI for 1, 3, and 5 days (d). In manul, the effect of Ss on arresting fibroblasts in the G0/G1 phase was noted after just 1d of culture at G70 confluence, while G50+Ss and cI+Ss were effective after 5d of treatment. In jaguarundi, 1–5d of G50+Ss and 5d of G70+Ss increased the percentage of G0/G1 cells versus d0 (P93% of cells were already in G0/G1 phase at d0 of Fc, suggesting that culture to Fc could be also a valuable method for fibroblast cell cycle synchronization in this species. In contrast to cI, prolonged Ss generated cell loss and could induce apoptosis and/or necrosis. In conclusion, Ss was the more efficient method for skin fibroblast cell cycle synchronization at the G0/G1 phase in manul, jaguarundi and the domestic cat. The response of cells to the treatments was species-specific, depending on cell confluence and duration of culture. This research may find application in preparing donor karyoplasts for SCNT in felids.

Published
2022

45. The influence of manual semen collection in male trained dogs (Canis familiaris), in the presence or absence of a female in estrus, on the concentrations of cortisol, oxytocin, prolactin and testosterone

Author

Woszczyło, Martyna, primary, Szumny, Antoni, additional, Knap, Piotr, additional, Jezierski, Tadeusz, additional, Niżański, Wojciech, additional, Kokocińska, Agata, additional, Skwark, Marcin J., additional, and Dzięcioł, Michał, additional

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results