Search results for "cryopreservation"
showing 10 items of 148 documents
Preservation of Multiple Mammalian Tissues to Maximize Science Return from Ground Based and Spaceflight Experiments.
2016
Background Even with recent scientific advancements, challenges posed by limited resources and capabilities at the time of sample dissection continue to limit the collection of high quality tissues from experiments that can be conducted only infrequently and at high cost, such as in space. The resources and time it takes to harvest tissues post-euthanasia, and the methods and duration of long duration storage, potentially have negative impacts on sample quantity and quality, thereby limiting the scientific outcome that can be achieved. Objectives The goals of this study were to optimize methods for both sample recovery and science return from rodent experiments, with possible relevance to b…
Effect of oocyte vitrification on embryo quality: time-lapse analysis and morphokinetic evaluation.
2017
To analyze whether oocyte vitrification may affect subsequent embryo development from a morphokinetic standpoint by means of time-lapse imaging.Observational cohort study.University-affiliated private IVF center.Ovum donation cycles conducted with the use of vitrified (n = 631 cycles; n = 3,794 embryos) or fresh oocytes (n = 1,359 cycles; n = 9,935 embryos) over 2 years.None.Embryo development was analyzed in a time-lapse imaging incubator. The studied variables included time to 2 cells (t2), 3 cells (t3), 4 cells (t4), 5 cells (t5), morula (tM), and cavitated, early, and hatching blastocyst (tB, tEB, tHB) as well as 2nd cell cycle duration (cc2 = t3 - t2). All of the embryos were classifie…
Randomized controlled trial comparing embryo culture in two incubator systems: G185 K-System versus EmbryoScope
2017
Objective To study whether the closed culture system, as compared with a benchtop incubator with similar culture conditions, has a positive impact on intracytoplasmic sperm injection (ICSI) outcomes. Design Randomized controlled trial. Setting University hospital. Patient(s) A total of 386 patients undergoing ICSI cycles with at least six mature oocytes were randomized. Intervention(s) Of these patients, 195 were assigned to the group with culture in a time-lapse imaging (TLI) system (EmbryoScope) and 191 to the group with culture in the G185 K-System (G185). Main Outcome Measure(s) Rate of implantation (primary endpoint) and embryo morphology grade. Result(s) No significant differences wer…
Theory about the Embryo Cryo‐Treatment
2017
Background To create hypothesis, which can give a logical explanation related to the benefits of freezing/thawing embryos. Cryopreservation is not only a technology used for storing embryos, but also a method of embryo treatment that can potentially improve the success rate in infertile couples. Methods From the analysis of multiple results in assisted reproductive technology, which have no satisfactory explanation to date, we found evidence to support a ‘therapeutic’ effect of the freezing/thawing of embryos on the process of recovery of the embryo and its subsequent implantation. Results Freezing/thawing is a way to activate the endogenous survival and repair responses in preimplantation …
An in vitro model for the study of human parathyroid gland tissue: Single cell suspensions and monolayer cultures
1982
An in vitro model for studies of parathyroid physiology is described using single cell suspensions and adherent monolayer cultures of human parathyroid tissue. The isolated cells were viable and maintained functional properties tested by calcium and magnesium sensitivity. Parathyroid hormone (PTH) secretion could be suppressed by rising calcium and magnesium concentrations. The secretory behaviour of the cells was not altered by cultivation or cryopreservation. The morphological integrity of the individual cells after mechanical and enzymatic preparation was confirmed by light and electron microscopy.
A Good Breath of Oxygen for Beta-Like Cells Obtained From Porcine Exocrine Pancreatic Tissue
2011
Ischemia is the most important factor that affects organ survival during harvesting. The two-layer method (TLM) is one of several cold storage solutions that seeks to preserve organs and cells avoiding in vivo and in vitro ischemia. We compared the retrieval of beta-like elements from exocrine pancreatic cells using TLM versus University of Wisconsin (UW) solutions. For this purpose pancreata laparoscopically harvested from 20 female pigs were preserved in UW solution or TLM before digestion. The resulting exocrine cells were divided into 2 groups: the first was cultured in a designed medium to allow differentiation into beta-like cells and the second was cryopreserved before the differenti…
Prediction of embryo survival and live birth rates after cryotransfers of vitrified blastocysts
2020
Which pre-vitrification parameters are the most predictive of survival and live birth in vitrified-warmed blastocyst transfer cycles?A retrospective study including 11,936 warmed blastocysts. Pre-vitrification morphological parameters analysed for blastocysts included day of vitrification; blastocyst expansion degree; trophoectoderm grade (A, B and C); and inner cell mass grade (A, B and C). Univariate and multivariate generalized estimating equations models were used to analyse survival, clinical pregnancy and live birth rate. A stepwise regression analysis was conducted to select and classify by order which outcomes were the most predictive.The odds of survival increased almost twice for …
False positive rate of an arrayCGH platform for single-cell preimplantation genetic screening and subsequent clinical application on day-3
2013
In this work, false positive rate of an arrayCGH platform for its use in day-3 single-blastomere analysis was calculated. For this purpose, 38 embryos diagnosed as abnormal on day-3 by FISH were re-biopsied on day-4. Single-cell day-4 arrayCGH diagnosis was then performed. A successful amplification was obtained in 97.4 % (37/38) of the day-4 cells analysed by arrayCGH. Day-3 FISH and day-4 arrayCGH diagnosis were concordant in 35/37 cases. The two discordant embryos were spread and all the cells from each embryo were re-analysed by FISH on day 5. The same error rate (2.7 %) for day-3 FISH and day-4 arrayCGH was obtained when comparing day-5 FISH re-analysis. After this pre-clinical phase, …
The Use of Frozen-Thawed Platelet-Derived Phospholipids as a Confirmatory Test for the Diagnosis of Lupus Anticoagulants. Comparison with Two Commerc…
1999
Lupus anticoagulants (LAs) belong to acquired circulating anticoagulants interfering with phospholipid-dependent coagulation tests. Owing to the remarkable variability among patients, SSC guidelines recommend more than one test to detect and confirm the presence of LAs. However, this is an expensive procedure and greatly raises the work load of the laboratory. A standardised platelet-derived phospholipid preparation was obtained and platelet neutralisation (PNP) procedures with APTT and DRVVT reagents were performed on plasmas from 16 patients with LAs and from 41 control subjects. In comparisons, STAclot-PNP and DVVconfirm clotting assays were conducted. PNP by using APTT or DRVVT reagents…
Cryopreservation and autotransplantation of human ovarian tissue prior to cytotoxic therapy – A technique in its infancy but already successful in fe…
2008
Increasing survival rates in young cancer patients, new reproductive techniques and the growing interest in quality of life after gonadotoxic cancer therapies have placed fertility preservation as an important issue to oncologists, fertility specialists and patients. Several techniques are now available for fertility preservation in these patients. A new promising method is cryopreservation and transplantation of ovarian cortex. Ovarian tissue can be extracted by laparoscopy without any significant delay of gonadotoxic therapy. The tissue can be cryopreserved by specialised centres of reproductive medicine and transplanted in case the women experience premature ovarian failure (POF). This r…