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International Journal of Environmental... Jul 2021Increasing numbers of women are undergoing oocyte or tissue cryopreservation for medical or social reasons to increase their chances of having genetic children. Social... (Review)
Review
Increasing numbers of women are undergoing oocyte or tissue cryopreservation for medical or social reasons to increase their chances of having genetic children. Social egg freezing (SEF) allows women to preserve their fertility in anticipation of age-related fertility decline and ineffective fertility treatments at older ages. The purpose of this study was to summarize recent findings focusing on the challenges of elective egg freezing. We performed a systematic literature review on social egg freezing published during the last ten years. From the systematically screened literature, we identified and analyzed five main topics of interest during the last decade: (a) different fertility preservation techniques, (b) safety of freezing, (c) usage rate of frozen oocytes, (d) ethical considerations, and (e) cost-effectiveness of SEF. Fertility can be preserved for non-medical reasons through oocyte, embryos, or ovarian tissue cryopreservation, with oocyte vitrification being a new and optimal approach. Elective oocyte cryopreservation is better accepted, supports social gender equality, and enhances women's reproductive autonomy. Despite controversies, planned oocyte cryopreservation appears as a chosen strategy against age-related infertility and may allow women to feel that they are more socially, psychologically, and financially stable before motherhood.
Topics: Aged; Child; Cryopreservation; Female; Fertility; Fertility Preservation; Humans; Middle Aged; Oocytes; Reproductive Techniques, Assisted
PubMed: 34360381
DOI: 10.3390/ijerph18158088 -
Molecules (Basel, Switzerland) Jun 2018Cosmetics, like any product containing water and organic/inorganic compounds, require preservation against microbial contamination to guarantee consumer’s safety and... (Review)
Review
Cosmetics, like any product containing water and organic/inorganic compounds, require preservation against microbial contamination to guarantee consumer’s safety and to increase their shelf-life. The microbiological safety has as main goal of consumer protection against potentially pathogenic microorganisms, together with the product’s preservation resulting from biological and physicochemical deterioration. This is ensured by chemical, physical, or physicochemical strategies. The most common strategy is based on the application of antimicrobial agents, either by using synthetic or natural compounds, or even multifunctional ingredients. Current validation of a preservation system follow the application of good manufacturing practices (GMPs), the control of the raw material, and the verification of the preservative effect by suitable methodologies, including the challenge test. Among the preservatives described in the positive lists of regulations, there are parabens, isothiasolinone, organic acids, formaldehyde releasers, triclosan, and chlorhexidine. These chemical agents have different mechanisms of antimicrobial action, depending on their chemical structure and functional group’s reactivity. Preservatives act on several cell targets; however, they might present toxic effects to the consumer. Indeed, their use at high concentrations is more effective from the preservation viewpoint being, however, toxic for the consumer, whereas at low concentrations microbial resistance can develop.
Topics: Anti-Infective Agents; Cosmetics; Preservation, Biological; Preservatives, Pharmaceutical
PubMed: 29958439
DOI: 10.3390/molecules23071571 -
Current Protocols in Molecular Biology Jan 2019We provide protocols for titering and isolating bacterial colonies from single cells by serial dilutions, for streaking agar plates, and for spreading suspensions of...
We provide protocols for titering and isolating bacterial colonies from single cells by serial dilutions, for streaking agar plates, and for spreading suspensions of cells on plates. Support protocols describe replica plating and methods for storing strains as agar stabs and frozen stocks. © 2018 by John Wiley & Sons, Inc.
Topics: Agar; Bacteriological Techniques; Colony Count, Microbial; Culture Media; Escherichia coli; Preservation, Biological
PubMed: 30414382
DOI: 10.1002/cpmb.82 -
Current Protocols in Cytometry Jul 2015Human peripheral blood is often studied by flow cytometry in both the research and clinical laboratories. The methods for collection, storage, and preparation of...
Human peripheral blood is often studied by flow cytometry in both the research and clinical laboratories. The methods for collection, storage, and preparation of peripheral blood will vary depending on the cell lineage to be examined as well as the type of assay to be performed. This unit presents protocols for collection of blood, separation of leukocytes from whole blood by lysis of erythrocytes, isolating mononuclear cells by density gradient separation, and assorted non-flow sorting methods, such as magnetic bead separations, for enriching specific cell populations, including monocytes, T lymphocytes, B lymphocytes, neutrophils, and platelets, prior to flow cytometric analysis. A protocol is also offered for cryopreservation of cells, since clinical research often involves retrospective flow cytometric analysis of samples stored over a period of months or years.
Topics: Ammonium Chloride; Antibodies; Anticoagulants; Blood Cells; Blood Platelets; Blood Specimen Collection; Cell Adhesion; Cell Fractionation; Cell Separation; Centrifugation, Density Gradient; Complement System Proteins; Cryopreservation; Erythrocytes; Humans; Indicators and Reagents; Leukocytes; Lymphocytes; Magnetic Phenomena; Microspheres; Monocytes; Plastics; Preservation, Biological; Staining and Labeling
PubMed: 26132177
DOI: 10.1002/0471142956.cy0501s73 -
Cryobiology Jun 2017Cryopreservation has become a central technology in many areas of clinical medicine, biotechnology, and species conservation within both plant and animal biology.... (Review)
Review
Cryopreservation has become a central technology in many areas of clinical medicine, biotechnology, and species conservation within both plant and animal biology. Cryoprotective agents (CPAs) invariably play key roles in allowing cells to be processed for storage at deep cryogenic temperatures and to be recovered with high levels of appropriate functionality. As such, these CPA solutes possess a wide range of metabolic and biophysical effects that are both necessary for their modes of action, and potentially complicating for cell biological function. Early successes with cryopreservation were achieved by empirical methodology for choosing and applying CPAs. In recent decades, it has been possible to assemble objective information about CPA modes of action and to optimize their application to living systems, but there still remain significant gaps in our understanding. This review sets out the current status on the biological and chemical knowledge surrounding CPAs, and the conflicting effects of protection versus toxicity resulting from the use of these solutes, which are often required in molar concentrations, far exceeding levels found in normal metabolism. The biophysical properties of CPAs that allow them to facilitate different approaches to cryogenic storage, including vitrification, are highlighted. The topics are discussed with reference to the historical background of applying CPAs, and the relevance of cryoprotective solutes in natural freeze tolerant organisms. Improved cryopreservation success will be an essential step in many future areas such as regenerative medicine, seed banking, or stem cell technology. To achieve this, we will need to further improve our understanding of cryobiology, where better and safer CPAs will be key requirements.
Topics: Animals; Antifreeze Proteins; Cell Physiological Phenomena; Cryopreservation; Cryoprotective Agents; Freezing; Humans; Ice; Organ Preservation; Solutions; Vitrification
PubMed: 28428046
DOI: 10.1016/j.cryobiol.2017.04.004 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2015In northern Europe during the Iron Age, many corpses were deposited in bogs. The cold, wet and anaerobic environment leads in many cases to the preservation of soft...
In northern Europe during the Iron Age, many corpses were deposited in bogs. The cold, wet and anaerobic environment leads in many cases to the preservation of soft tissues, so that the bodies, when found and excavated several thousand years later, are remarkably intact. Since the 19th century the bog bodies have been studied using medical and natural scientific methods, and recently many bog bodies have been re-examined using especially modern, medical imaging techniques. Because of the preservation of soft tissue, especially the skin, it has been possible to determine lesions and trauma. Conversely, the preservation of bones is less good, as the mineral component has been leached out by the acidic bog. Together with water-logging of collagenous tissue, this means that if the bog body is simply left to dry out when found, as was the case pre-19th century, the bones may literally warp and shrink, leading to potential pitfalls in paleopathological diagnostics. Bog bodies have in several instances been crucial in determining the last meal, as gut contents may be preserved, and thus augment our knowledge on pre-historic diet by adding to, for example, stable isotope analyses. This article presents an overview of our knowledge about the taphomic processes as well as the methods used in bog body research.
Topics: Humans; Mummies; Paleopathology; Tissue Preservation; Wetlands
PubMed: 25998635
DOI: 10.1002/ar.23138 -
Malaria Journal May 2021Mosquito species from the Anopheles gambiae complex and the Anopheles funestus group are dominant African malaria vectors. Mosquito microbiota play vital roles in...
BACKGROUND
Mosquito species from the Anopheles gambiae complex and the Anopheles funestus group are dominant African malaria vectors. Mosquito microbiota play vital roles in physiology and vector competence. Recent research has focused on investigating the mosquito microbiota, especially in wild populations. Wild mosquitoes are preserved and transported to a laboratory for analyses. Thus far, microbial characterization post-preservation has been investigated in only Aedes vexans and Culex pipiens. Investigating the efficacy of cost-effective preservatives has also been limited to AllProtect reagent, ethanol and nucleic acid preservation buffer. This study characterized the microbiota of African Anopheles vectors: Anopheles arabiensis (member of the An. gambiae complex) and An. funestus (member of the An. funestus group), preserved on silica desiccant and RNAlater solution.
METHODS
Microbial composition and diversity were characterized using culture-dependent (midgut dissections, culturomics, MALDI-TOF MS) and culture-independent techniques (abdominal dissections, DNA extraction, next-generation sequencing) from laboratory (colonized) and field-collected mosquitoes. Colonized mosquitoes were either fresh (non-preserved) or preserved for 4 and 12 weeks on silica or in RNAlater. Microbiota were also characterized from field-collected An. arabiensis preserved on silica for 8, 12 and 16 weeks.
RESULTS
Elizabethkingia anophelis and Serratia oryzae were common between both vector species, while Enterobacter cloacae and Staphylococcus epidermidis were specific to females and males, respectively. Microbial diversity was not influenced by sex, condition (fresh or preserved), preservative, or preservation time-period; however, the type of bacterial identification technique affected all microbial diversity indices.
CONCLUSIONS
This study broadly characterized the microbiota of An. arabiensis and An. funestus. Silica- and RNAlater-preservation were appropriate when paired with culture-dependent and culture-independent techniques, respectively. These results broaden the selection of cost-effective methods available for handling vector samples for downstream microbial analyses.
Topics: Animals; Anopheles; Bacteria; Microbiota; Mosquito Vectors; Preservation, Biological; South Africa; Specimen Handling
PubMed: 34022891
DOI: 10.1186/s12936-021-03754-7 -
Journal of Physiology and Pharmacology... Jun 2023Cryopreservation is a procedure of a long-term storage of cells and/or tissues at a temperature that prevents cell divisions and metabolic processes. Due to ability to... (Review)
Review
Cryopreservation is a procedure of a long-term storage of cells and/or tissues at a temperature that prevents cell divisions and metabolic processes. Due to ability to self-renewal and differentiation into more specialised cells, stem cells may be helpful in repairing of other damaged organs or tissues. Cryopreservation allows the frozen genetic material to maintain its biological properties for a long time. Therefore, there is a real chance for some samples to be used in the future therapy of the pathological conditions that at present remain incurable because of the current state of knowledge. The purpose of this review is to describe the modern methods of extraction, preservation, and storage of dental stem cells at low temperatures in particular procedure of collecting and transporting tissues intended for freezing, precise characteristics of stem cells of dentary origin and methods of their isolation using Enzymatic Digestion and Spontaneous Outgrowth. In the paper are also presented technical details of the protocols of rapid rate freezing, controlled rate milling and freezing in a magnetic field (magnetic freezing) which provides precise information about procedures of thawing cells and unfavourable effect of negative temperature on the biological properties of stem cells. Dental tissues may constitute a rich source of stem cells. The inexpensive, simple and quick procedure of their extraction is minimally invasive and does not pose a threat to the donor's organism. Transferring autologous cells within the same organism does not present a potential risk of transplant rejection and thereof does not raise ethical controversies. Laboratory procedures including cell preparation, its characteristics and genetic features, basics on the process of freezing, thawing, as well as quality control essentials have been also outlined.
Topics: Cryopreservation; Stem Cells; Cold Temperature; Cell Differentiation
PubMed: 37661179
DOI: 10.26402/jpp.2023.3.02 -
PloS One 2022Although 37.5-51% of transgender adults state they would've considered freezing gametes before gender-affirming therapy if offered and 24-25.8% of transgender...
Although 37.5-51% of transgender adults state they would've considered freezing gametes before gender-affirming therapy if offered and 24-25.8% of transgender adolescents express interest in having biological children, less than 5% of transgender adolescents have opted for fertility preservation. We sought to assess fertility preservation utilization in our multidisciplinary adolescent gender clinic. We also aimed to identify fertility preservation utilization and interest among non-binary adolescents and young adults. A retrospective review was conducted of patients seen in the Stanford Pediatric & Adolescent Gender Clinic from October 2015 through March 2019 who were >10 years of age at initial visit. All individuals with documented discussion of fertility preservation were offered referral for formal fertility preservation consultation but only 24% of patients accepted. Only 6.8% of individuals subsequently underwent fertility preservation (n = 9). Transfeminine adolescents are more likely to pursue fertility preservation than transmasculine adolescents (p = 0.01). The rate of fertility preservation in non-binary adolescents did not significantly differ from those in transfeminine adolescents (p = 1.00) or transmasculine adolescents (p = 0.31). Although only one non-binary individual underwent fertility preservation, several more expressed interest with 36% accepting referral (n = 4) and 27% being seen in consultation (n = 3). Despite offering fertility preservation with designated members of a gender clinic team, utilization remains low in transgender adolescents. Additionally, non-binary adolescents and their families are interested in fertility preservation and referrals should be offered to these individuals. Further studies and advocacy are required to continue to address fertility needs of transgender adolescents.
Topics: Adolescent; Child; Cryopreservation; Fertility; Fertility Preservation; Humans; Transgender Persons; Transsexualism; Young Adult
PubMed: 35275955
DOI: 10.1371/journal.pone.0265043 -
Andrology Nov 2020The sperm vitrification developed by this group is based on the ultrarapid freezing of a vitrification solution composed of a non-permeable cryoprotectant (saccharides... (Review)
Review
BACKGROUND
The sperm vitrification developed by this group is based on the ultrarapid freezing of a vitrification solution composed of a non-permeable cryoprotectant (saccharides and protein), in which previously selected spermatozoa are resuspended, free of seminal plasma, and then plunged directly into liquid nitrogen. Compared to traditional sperm freezing, vitrification does not cause chemical or physical damage to the intracellular structures and reduces the damage to the plasma membrane because no ice crystals form, thus preserving motility and DNA integrity.
OBJECTIVES
This manuscript is a review of the vitrification methodology developed by the authors' research group, including studies showing the application in human reproduction therapy.
MATERIALS AND METHODS
The authors perform a review of the work initiated more than a decade ago by this research group, on the implementation of sperm vitrification, a more effective technique for cryopreservation of human spermatozoa, discussing the results obtained by other authors and the projection of this technique.
RESULTS AND DISCUSSION
The vitrification technique has been developed in selected spermatozoa free of seminal plasma supplemented with saccharides such as sucrose, trehalose, and dextran, together with albumin, providing a high motility rate and protective structures of the cytoskeleton. In patients, it can be used to preserve their fertility for oncological reasons, genetics, inflammatory diseases, or reproductive medicine techniques. The possibility that vitrified spermatozoa can be preserved at temperatures of -80°C can simplify sample storage, optimizing the space and time as well as operator safety.
CONCLUSION
Vitrification techniques have demonstrated the preservation of selected spermatozoa without seminal plasma and with non-permeable cryoprotectants and protein. Currently, it is one of the most effective ways to maintain sperm function and has been used in in vitro fertilization or intrauterine insemination in humans, achieving healthy live births.
Topics: Cryopreservation; Cryoprotective Agents; Diffusion of Innovation; Female; Fertility; Fertility Preservation; Humans; Infertility; Male; Pregnancy; Risk Factors; Semen Preservation; Spermatozoa; Treatment Outcome; Vitrification
PubMed: 32598551
DOI: 10.1111/andr.12847