Biomedical subjects

P Trávník

Publications and source records attributed to P Trávník.

At least 19 recordsLinked to original sources

PubMed2003

[Preimplantation genetic diagnosis (PGD) of chromosomal aberrations using the fluorescence in situ hybridization method (FISH)--introduction to problems, sampling methods and examination techniques].

OBJECTIVE: Presentation of preimplantation genetic diagnosis and the set of laboratory processes like aspiration, preparation and evaluation of polar bodies, sperm cells and blastomeres using FISH method (fluorescent in situ hybridization) in ART. DESIGN: Review. SETTING: Sanatorium REPROMEDA, Brno, Veterinary Research Institute, Brno. METHODS: Overview of published data and own clinical experience with the cell aspiration methods, evaluated sample preparation and the proper chromosomes visualisation using FISH method. CONCLUSION: The review brings an overview of conditions and methods including sample obtaining, FISH analysis preparation and implementation, processed during PGD.

Chromosome Disorders↗

PubMed1997

[The effect of spermatozoal ultrastructure on the outcome of fertilization in vitro].

UNLABELLED: The ultrastructure of sperm cells in cumulus oophorus of the human oocyte 20 hrs after in vitro fertilization (IVF) was studied. MATERIALS AND METHODS: Mechanically removed cumular cells were processed for electron microscopy and the spermatozoa deposited in the intracellular spaces as well as those penetrating into follicular cells were evaluated. The samples were divided into three groups. Group I contained cumuli from unfertilized oocytes, group II involved those from fertilized oocytes, but not pregnancy after embryo transfer. Group III was formed by cumuli from fertilized oocytes of patients, where pregnancy had been achieved. RESULTS: In group I numerous anomalies of spermatozoal ultrastructure were found, such as head malformations, incompleted chromatin condensation, large cytoplasmatic droplets, etc. In groups II and III, about 70% normal sperm cells were found. CONCLUSIONS: These findings provide evidence of the important role of the morphological quality of spermatozoa in the failure of in vitro fertilization, also in cases where anomalies could not be detected by the usual methods of sperm examination.

Female↗

PubMed1996

[Assisted hatching--a useful micromanipulation technic in women after repeated failure of embryo transfer].

One reason for the low implantation rate after IVF/ET is the limiting ability of blastocysts to escape from the zona pellucida, and of nidation. This procedure can be assisted by the creation of an artificial opening in the zona pellucida before the transfer (assisted hatching). An artificial slot in the zona of 58 embryos (20 patients) was created mechanically by using Leitz Fluovert microscope and Narishige micromanipulators. From 20 embryo transfers 6 clinical pregnancies resulted (30.0% clin. preg. rate). In 4 cases women with three or more unsuccessful transfers were involved. This method should be used in classical IVF, specially in cases of repeated high quality embryo transfers which failed.

Embryo Transfer↗

PubMed1996

[Prolonged culture of human embryos: comparison of coculture on human tubal epithelium and culture in synthetic media].

UNLABELLED: The aim of this work was to evaluate prolongation of cultivation time of human embryos. The prolongation above the standard limit was implemented (1) by coculture of embryos on a monolayer of human epithelial cells and (2) by using a synthetic medium. MATERIAL AND METHODS: Ovarian stimulation, oocyte recovery, insemination and cultivation up to the pronuclear stage were done in our centre in the usual way. Group I: 104 women, prolonged culture by the coculture method. The zygotes were placed on the monolayer and cultivated for an other 24 or 48 hours. Group II: 249 women, prolonged culture in a synthetic medium. The zygotes were cultivated up to the 2- to 4-cell stage in standard IVF medium, and then put into M3 medium for the next 24 or 48 hours. A transfer of a maximum of 4 embryos was done. RESULTS: In group I in 104 women from 341 zygotes 181 embryos (53.1%) reached the eight- and more than eight-cell stage, and 76 transfers were done. 15 pregnancies were achieved (19.4% pregnancy rate). In group II in 249 patients from 672 embryos 49.7% of them reached 8- and more than 8-cell stage. 51 pregnancies were achieved (22.6 pregnancy rate). In the control group of 250 IVF after 48 hours cultivation 165 transfers (66.0%) were done, and 16.4% pregnancies were achieved, i.e. 6.2% less compared to synthetic medium and 3.3% less than in cocultivation. CONCLUSION: There is evidence of better IVF/ET results in case of prolonged culture time. The experience in our centre has shown the need of reevaluation of the coculture method. The exacting character of its preparation and manipulation will have to be replaced by synthetic media in spite of their high price.

Cells, Cultured↗

PubMed1994

Determination of intracytoplasmic filaments in the chondrocytes of articular cartilage.

Intracytoplasmic filaments were demonstrated in the chondrocytes of articular cartilage of cattle at 82 days post partum and at 3 and 4 years of age using transmission electron microscopy and immunocytochemistry. Samples of cartilage for electron microscopy were processed in a standard way. Immunocytochemical procedures were performed with semithin sections made from the material prepared for electron microscopy after embedding medium and osmium compounds had been eliminated. Vimentin filaments were demonstrated by means of anti-vimentin monoclonal antibody visualized by peroxidase-labelled immunoglobulin. Both techniques showed that intracytoplasmic filaments were situated around the nucleus and only occasionally at the cell periphery, e.g. in cell projections.

Aging↗

PubMed1990

[Gamete and embryo transfer in conjunction with microsurgical treatment of sterility].

The authors evaluate the results of the programme of transfer of gametes into the oviduct or of embryos into the uterus in conjunction with microsurgery of sterile women. During the period between August 1981 and December 1988 a total of 211 microsurgical operations were made in stimulated cycles. The ovaries were stimulated with clomiphene citrate or in combination with human menopausal gonadotropin. The operation was made 36 hours after administration of human choriogonadotropic hormone. In 146 women at least one oocyte was obtained. A total of 72 gametotransfers into the oviduct were made and in eight, i. e. 11.1%; pregnancy was achieved. Of 43 embryotransfers five pregnancies were achieved, i. e. 11.6%. A total of 13 pregnancies were achieved with four spontaneous deliveries, seven miscarriages and two extrauterine pregnancies. The combination of selected cases of microsurgery of sterility with the IVF programme increases the rate of successful operations without a further burden for the patient, and it extends the possibilities of sterility treatment.

Adult↗

PubMed1989

Specific antibody against the Aujeszky's disease virus in the complex cumulus oophorus-oocyte of sows.

Oocytes collected from sows vaccinated and revaccinated with an inactivated vaccine against Aujeszky's disease (AD) were examined for the presence of specific antibodies of the IgG class against AD virus in the complex cumulus oophorus-oocyte by means of immunocytochemical methods. No specific antibody of the IgG class was detected in the cumulus-oocyte complexes collected from sows before vaccination. On the other hand, the specific IgG antibody was found in all immunocytochemically examined complexes cumulus-oocyte collected from revaccinated sows. The specific antibody of the IgG class against AD virus and the porcine IgG were immunocytochemically visualized under both light and electron microscopes as a fine granular product disseminated in oocytes and follicular cells.

Animals↗

PubMed1989

[Initial experience with cryopreservation of human embryos].

We present our first experience with human embryo cryopreservation. In our hands the best results were obtained with cryopreservation of pronuclear-staged embryos using propanediol as cryoprotectant. In this group 3 embryos out of 4 continued their development after thawing. The advantages of embryo cryopreservation in IVF programs are discussed.

Cryopreservation↗

PubMed1989

[Developmental capacity of human embryos after cryopreservation in the unicellular zygote stage].

This study deals with the developmental competence of human embryos after cryopreservation at the one-cell stage using propanediol as cryoprotectant. From 11 frozen zygotes, nine underwent cleavage after thawing. The occurrence of multinuclear blastomeres was the most frequent abnormality which, however, can often be observed in fresh embryos as well. The results of an ultrastructural analysis of the developing frozen-thawed embryos, with special attention to markers of embryonic genome expression, did not show any noticeable impairment of the developmental competence of these embryos as compared with parameters previously described for unfrozen embryos. The findings are discussed with particular reference to current freezing policies in human in-vitro fertilization programmes.

Cryopreservation↗

PubMed1989

[A simple microphotographic method for the evaluation of sperm motility].

A simple objective method for examination of sperm quality, both for practical and research purposes, is described. The results obtained show that the evaluation of samples must be performed by 15 minutes after the removal of the spermatozoa from the culture system and by 5 minutes after the placement on the microscope slide, in order to avoid the influence of external conditions on sperm motility. From the comparison of parameters examined (percentage of sperm motility, mean velocity, lateral head displacement, number of waves per second, distribution in individual speed intervals) it follows that media used for sperm incubation (B2 and F 10) do not affect negatively sperm motility and may be exchanged with each other if necessary. The results contribute to the improvement of diagnostic and treatment of andrological disturbances. The study will be used in our programme of treatment of infertile couples.

Humans↗

PubMed1988

Zona pellucida resistance to sperm penetration before the completion of human oocyte maturation.

Human oocytes exposed to capacitated spermatozoa in vitro when at metaphase of the 1st meiotic division (metaphase I) were not penetrated, even though some subsequently progressed to metaphase of the 2nd meiotic division (metaphase II). When the non-penetrated oocytes that had reached metaphase II during the incubation with spermatozoa were freed from the zona pellucida and reinseminated, two or more pronuclei developed in most of them. By contrast, no penetration was observed when the oocytes were reinseminated in the zona-intact state. When compared with metaphase II oocytes, metaphase I oocytes had a similar zona-binding capacity for spermatozoa, but fewer spermatozoa were found within the zona. These results indicate that the zona pellucida of human oocytes undergoes important maturational changes during the transition from metaphase I to metaphase II. Ultrastructural and previous histochemical findings suggest that these changes involve secretions from both the oocyte and cumulus cells and that the increased zona resistance at metaphase I may be due to relative insufficiency of cumulus cell-secreted 'softening' factors. If the integrity of the cumulus oophorus is disturbed at this stage, this condition becomes irreversible.

Female↗

PubMed1987