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Fertility and Sterility Jul 2022To review the outcomes of patients who underwent autologous oocyte thaw after planned oocyte cryopreservation.
OBJECTIVE
To review the outcomes of patients who underwent autologous oocyte thaw after planned oocyte cryopreservation.
DESIGN
Retrospective cohort study.
SETTING
Large urban university-affiliated fertility center.
PATIENT(S)
All patients who underwent ≥1 autologous oocyte thaw before December 31, 2020.
INTERVENTION(S)
None.
MAIN OUTCOME MEASURE(S)
The primary outcome was the final live birth rate (FLBR) per patient, and only patients who had a live birth (LB) or consumed all remaining inventory (cryopreserved oocytes and resultant euploid/untested/no result embryos) were included. The secondary outcomes were laboratory outcomes and LB rates per transfer.
RESULT(S)
A total of 543 patients underwent 800 oocyte cryopreservations, 605 thaws, and 436 transfers. The median age at the first cryopreservation was 38.3 years. The median time between the first cryopreservation and thaw was 4.2 years. The median numbers of oocytes and metaphase II oocytes (M2s) thawed per patient were 14 and 12, respectively. Overall survival of all thawed oocytes was 79%. Of all patients, 61% underwent ≥1 transfer. Among euploid (n = 262) and nonbiopsied (n = 158) transfers, the LB rates per transfer were 55% and 31%, respectively. The FLBR per patient was 39%. Age at cryopreservation and the number of M2s thawed were predictive of LB; the FLBR per patient was >50% for patients aged <38 years at cryopreservation or who thawed ≥20 M2s. A total of 173 patients (32%) have remaining inventory.
CONCLUSION(S)
Autologous oocyte thaw resulted in a 39% FLBR per patient, which is comparable with age-matched in vitro fertilization outcomes. Studies with larger cohorts are necessary.
Topics: Cryopreservation; Fertilization in Vitro; Humans; Oocytes; Retrospective Studies; Universities
PubMed: 35597614
DOI: 10.1016/j.fertnstert.2022.04.013 -
Genes Jul 2020The ability of yeast to survive freezing and thawing is most frequently considered in the context of cryopreservation, a practical step in both industrial and research... (Review)
Review
The ability of yeast to survive freezing and thawing is most frequently considered in the context of cryopreservation, a practical step in both industrial and research applications of these organisms. However, it also relates to an evolved ability to withstand freeze-thaw stress that is integrated with a larger network of survival responses. These responses vary between different strains and species of yeast according to the environments to which they are adapted, and the basis of this adaptation appears to be both conditioned and genetic in origin. This review article briefly touches upon common yeast cryopreservation methods and describes in detail what is known about the biochemical and genetic determinants of cell viability following freeze-thaw stress. While we focus on the budding yeast , in which the freeze-thaw stress response is best understood, we also highlight the emerging diversity of yeast freeze-thaw responses as a manifestation of biodiversity among these organisms.
Topics: Adaptation, Physiological; Cryopreservation; Freezing; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins
PubMed: 32707778
DOI: 10.3390/genes11080835 -
Cryobiology Dec 2020Mesenchymal stromal cells (MSCs) have been demonstrated to possess anti-inflammatory and antimicrobial properties and are of interest in biotechnologies that will...
Mesenchymal stromal cells (MSCs) have been demonstrated to possess anti-inflammatory and antimicrobial properties and are of interest in biotechnologies that will require cryopreservation. Recently, MSC-like cells were isolated from colostrum and milk. We used an interrupted slow freezing procedure to examine cryoinjury incurred during slow cooling and rapid cooling of MSC-like cells from swine colostrum. Cells were loaded with either dimethyl sulfoxide (MeSO) or glycerol, cooled to a nucleation temperature, ice-nucleated, and further cooled at 1 °C/min. At several temperatures along the cooling path, cells were either thawed directly, or plunged into liquid nitrogen for storage and later thawed. The pattern of direct-thaw and plunge-thaw responses was used to guide optimization of cryopreservation protocol parameters. We found that both 5% MeSO (0.65 M, loaded for 15 min on ice) or 5% glycerol (0.55 M, loaded for 1 h at room temperature) yielded cells with high post-thaw membrane integrity when cells were cooled to at least -30 °C before being plunged into, and stored in, liquid nitrogen. Cells cultured post-thaw exhibited osteogenic differentiation similar to fresh unfrozen control. Fresh and cryopreserved MSC-like cells demonstrated antimicrobial activity against S. aureus. Also, the antimicrobial activity of cell-conditioned media was higher when both fresh and cryopreserved MSC-like cells were pre-exposed to S. aureus. Thus, we were able to demonstrate cryopreservation of colostrum-derived MSC-like cells using MeSO or glycerol, and show that both cryoprotectants yield highly viable cells with osteogenic potential, but that cells cryopreserved with glycerol retain higher antimicrobial activity post-thaw.
Topics: Animals; Cell Survival; Colostrum; Cryopreservation; Cryoprotective Agents; Dimethyl Sulfoxide; Female; Osteogenesis; Pregnancy; Staphylococcus aureus; Swine
PubMed: 32464145
DOI: 10.1016/j.cryobiol.2020.05.010 -
Nature Communications Aug 2022Permafrost thaw can stimulate microbial decomposition and induce soil carbon (C) loss, potentially triggering a positive C-climate feedback. However, earlier...
Permafrost thaw can stimulate microbial decomposition and induce soil carbon (C) loss, potentially triggering a positive C-climate feedback. However, earlier observations have concentrated on bulk soil C dynamics upon permafrost thaw, with limited evidence involving soil C fractions. Here, we explore how the functionally distinct fractions, including particulate and mineral-associated organic C (POC and MAOC) as well as iron-bound organic C (OC-Fe), respond to permafrost thaw using systematic measurements derived from one permafrost thaw sequence and five additional thermokarst-impacted sites on the Tibetan Plateau. We find that topsoil POC content substantially decreases, while MAOC content remains stable and OC-Fe accumulates due to the enriched Fe oxides after permafrost thaw. Moreover, the proportion of MAOC and OC-Fe increases along the thaw sequence and at most of the thermokarst-impacted sites. The relatively enriched stable soil C fractions would alleviate microbial decomposition and weaken its feedback to climate warming over long-term thermokarst development.
Topics: Carbon; Climate; Minerals; Permafrost; Soil
PubMed: 36038568
DOI: 10.1038/s41467-022-32681-7 -
Tree Physiology Jan 2023Conifers inhabit some of the most challenging landscapes where multiple abiotic stressors (e.g., aridity, freezing temperatures) often co-occur. Physiological tolerance... (Review)
Review
Conifers inhabit some of the most challenging landscapes where multiple abiotic stressors (e.g., aridity, freezing temperatures) often co-occur. Physiological tolerance to multiple stressors ('poly-tolerance') is thought to be rare because exposure to one stress generally limits responses to another through functional trade-offs. However, the capacity to exhibit poly-tolerance may be greater when combined abiotic stressors have similar physiological impacts, such as the disruption of hydraulic function imposed by drought or freezing. Here, we reviewed empirical data in light of theoretical expectations for conifer adaptations to drought and freeze-thaw cycles with particular attention to hydraulic traits of the stem and leaf. Additionally, we examined the commonality and spatial distribution of poly-stress along indices of these combined stressors. We found that locations with the highest values of our poly-stress index (PSi) are characterized by moderate drought and moderate freeze-thaw, and most of the global conifer distribution occupies areas of moderate poly-stress. Among traits examined, we found diverse responses to the stressors. Turgor loss point did not correlate with freeze-thaw or drought stress individually, but did with the PSi, albeit inverse to what was hypothesized. Leaf mass per area was more strongly linked with drought stress than the poly-stress and not at all with freeze-thaw stress. In stems, the water potential causing 50% loss of hydraulic conductivity became more negative with increasing drought stress and poly-stress but did not correlate with freeze-thaw stress. For these traits, we identified a striking lack of coverage for substantial portions of species ranges, particularly at the upper boundaries of their respective PSis, demonstrating a critical gap in our understanding of trait prevalence and plasticity along these stress gradients. Future research should investigate traits that confer tolerance to both freeze-thaw and drought stress in a wide range of species across broad geographic scales.
Topics: Freezing; Tracheophyta; Droughts; Cold Temperature; Plant Leaves; Water; Cycadopsida
PubMed: 36094836
DOI: 10.1093/treephys/tpac102 -
Genes Mar 2021Sperm chemotaxis, which guide sperm toward oocyte, is tightly associated with sperm capacitation, motility, and fertility. However, the molecular mechanism of sperm... (Review)
Review
Sperm chemotaxis, which guide sperm toward oocyte, is tightly associated with sperm capacitation, motility, and fertility. However, the molecular mechanism of sperm chemotaxis is not known. Reproductive odorant and taste receptors, belong to G-protein-coupled receptors (GPCR) super-family, cause an increase in intracellular Ca concentration which is pre-requisite for sperm capacitation and acrosomal reaction, and result in sperm hyperpolarization and increase motility through activation of Ca-dependent Cl channels. Recently, odorant receptors (ORs) in olfactory transduction pathway were thought to be associated with post-thaw sperm motility, freeze tolerance or freezability and cryo-capacitation-like change during cryopreservation. Investigation of the roles of odorant and taste receptors (TRs) is important for our understanding of the freeze tolerance or freezability mechanism and improve the motility and fertility of post-thaw sperm. Here, we reviewed the roles, mode of action, impact of odorant and taste receptors on sperm chemotaxis and post-thaw sperm quality.
Topics: Animals; Chemotaxis; Cryopreservation; Humans; Male; Receptors, G-Protein-Coupled; Receptors, Odorant; Sperm Capacitation; Sperm Motility; Spermatozoa
PubMed: 33801624
DOI: 10.3390/genes12040488 -
Environmental Microbiology Dec 2022Climate warming has increased permafrost thaw in arctic tundra and extended the duration of annual thaw (number of thaw days in summer) along soil profiles. Predicting...
Climate warming has increased permafrost thaw in arctic tundra and extended the duration of annual thaw (number of thaw days in summer) along soil profiles. Predicting the microbial response to permafrost thaw depends largely on knowing how increased thaw duration affects the composition of the soil microbiome. Here, we determined soil microbiome composition from the annually thawed surface active layer down through permafrost from two tundra types at each of three sites on the North Slope of Alaska, USA. Variations in soil microbial taxa were found between sites up to ~90 km apart, between tundra types, and between soil depths. Microbiome differences at a site were greatest across transitions from thawed to permafrost depths. Results from correlation analysis based on multi-decadal thaw surveys show that differences in thaw duration by depth were significantly, positively correlated with the abundance of dominant taxa in the active layer and negatively correlated with dominant taxa in the permafrost. Microbiome composition within the transition zone was statistically similar to that in the permafrost, indicating that recent decades of intermittent thaw have not yet induced a shift from permafrost to active-layer microbes. We suggest that thaw duration rather than thaw frequency has a greater impact on the composition of microbial taxa within arctic soils.
Topics: Permafrost; Soil; Tundra; Soil Microbiology; Arctic Regions; Microbiota
PubMed: 36135820
DOI: 10.1111/1462-2920.16218 -
BMC Plant Biology Mar 2022The freeze-thaw of early spring in China's Qinghai-Tibet Plateau is often accompanied by severe droughts. Artemisia annua, widely distributed in China, releases...
The freeze-thaw of early spring in China's Qinghai-Tibet Plateau is often accompanied by severe droughts. Artemisia annua, widely distributed in China, releases allelopathic substances, mainly artemisinin, to the environment and exerts a wide range of effects on crops. This paper studied the physiological effects of highland barley under freeze-thaw, drought, and artemisinin stress through indoor simulation experiments. The physiological response characteristics of superoxide dismutase (SOD) activity, catalase (POD) activity, net photosynthetic rate, relative water content (RWC), relative electrical conductivity, malondialdehyde (MDA) content, and soluble protein content in highland barley were analyzed. The results showed that artemisinin and drought contributed to the increase of SOD activity and the decrease of POD activity. Under the freeze-thaw stress, the SOD and POD activities both decreased firstly and then increased, but the effect of compound stress on POD was more complicated. Either artemisinin, drought, or low temperature could reduce the net photosynthetic rate of highland barley. Low temperature had more significant impacts on photosynthesis, and compound stress would show a single stress superimposed effect. Artemisinin, drought, and low temperature could reduce the RWC of highland barley, and increase the relative electrical conductivity and the concentration of soluble protein (except for low temperature stress above zero, which reduces the concentration of soluble protein). However, the effect of compound stress on soluble protein is more complex. The single stress of artemisinin and drought had no obvious effect on MDA content, while the MDA content was increased significantly under the freeze-thaw stress and the compound stress of artemisinin and drought, and the MDA content reached its peak at T1. The results are helpful to explore the effects of freeze-thaw, drought and artemisinin stress on the growth of highland barley under the background of the aridification of the Qinghai-Tibet Plateau, and provide ideas for rational agricultural management.
Topics: Artemisinins; Droughts; Freezing; Hordeum; Photosynthesis
PubMed: 35300590
DOI: 10.1186/s12870-022-03520-0 -
FEMS Microbiology Ecology Oct 2023Permafrost soils store a substantial part of the global soil carbon and nitrogen. However, global warming causes abrupt erosion and gradual thaw, which make these stocks...
Permafrost soils store a substantial part of the global soil carbon and nitrogen. However, global warming causes abrupt erosion and gradual thaw, which make these stocks vulnerable to microbial decomposition into greenhouse gases. Here, we investigated the microbial response to abrupt in situ permafrost thaw. We sequenced the total RNA of a 1 m deep soil core consisting of up to 26 500-year-old permafrost material from an active abrupt erosion site. We analysed the microbial community in the active layer soil, the recently thawed, and the intact permafrost, and found maximum RNA:DNA ratios in recently thawed permafrost indicating a high microbial activity. In thawed permafrost, potentially copiotrophic Burkholderiales and Sphingobacteriales, but also microbiome predators dominated the community. Overall, both thaw-dependent and long-term soil properties significantly correlated with changes in community composition, as did microbiome predator abundance. Bacterial predators were dominated in shallower depths by Myxococcota, while protozoa, especially Cercozoa and Ciliophora, almost tripled in relative abundance in thawed layers. Our findings highlight the ecological importance of a diverse interkingdom and active microbial community highly abundant in abruptly thawing permafrost, as well as predation as potential biological control mechanism.
Topics: Permafrost; Soil; Bacteria; Microbiota; Carbon; RNA; Soil Microbiology
PubMed: 37796894
DOI: 10.1093/femsec/fiad123 -
Scientific Reports Feb 2022The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in...
The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in studying extracellular vesicles (EVs) and cell-free messenger RNA (cf-mRNA) as potential biomarkers, how blood processing and freeze/thaw impacts the profiles of these analytes in plasma was not thoroughly understood. We utilized flow cytometric analysis to examine the effect of differential centrifugation and a freeze/thaw cycle on EV profiles. Utilizing flow cytometry postacquisition analysis software (FCMpass) to calibrate light scattering and fluorescence, we revealed how differential centrifugation and post-freeze/thaw processing removes and retains EV subpopulations. Additionally, cf-mRNA levels measured by RT-qPCR profiles from a panel of housekeeping, platelet, and tissue-specific genes were preferentially affected by differential centrifugation and post-freeze/thaw processing. Critically, freezing plasma containing residual platelets yielded irreversible ex vivo generation of EV subpopulations and cf-mRNA transcripts, which were not removable by additional processing after freeze/thaw. Our findings suggest the importance of minimizing confounding variation attributed to plasma processing and platelet contamination.
Topics: Blood; Cell-Free Nucleic Acids; Cryopreservation; Extracellular Vesicles; Flow Cytometry; Humans; RNA, Messenger
PubMed: 35136102
DOI: 10.1038/s41598-022-06088-9