Complications of open thoracoabdominal aortic aneurysm repair
Sachinder Singh Hans, Mark F. Conrad in Vascular and Endovascular Complications, 2021
Cryopreservation of cellular tissue has been employed for decades. Similarly, it has been shown that hypothermia can reduce metabolic rate and oxygen demand in nervous tissue.15 Based on this principle, in 2000, Cambria and Davison developed a method for regional spinal cord hypothermia with epidural cooling that was successful in 97% of patients in their series, with a spinal cord ischemia rate of 7% overall (type I/II 12%, all other types, 2.3%) in the setting of a clamp-and-sew technique with selective intercostal reimplantation.29 While we no longer employ this technique routinely, we do continue to use mild permissive corporeal hypothermia (32–34°C) during repair. Deep hypothermic circulatory arrest has been used to hypothetically decrease rates of paralysis, but this is typically only used in TAAA operations that involve the distal arch or to avoid cross clamping aorta affected by connective tissue disease.15
Clinical Progresses in Regenerative Dentistry and Dental Tissue Engineering
Vincenzo Guarino, Marco Antonio Alvarez-Pérez in Current Advances in Oral and Craniofacial Tissue Engineering, 2020
One crucial feature of pulp cells is their odontoblastic differentiation potential which is why they are called odontoblastoid cells, as these cells appear to synthesize and secrete dentin matrix like the odontoblasts cells they replace. Human pulp cells can be induced in vitro to differentiate into cells of odontoblastic phenotype, characterized by polarized cell bodies and accumulation of mineralized nodules (Couble et al. 2000). DPSCs isolated with enzyme treatment of pulp tissues form CFU Fs with various characteristics (Gronthos et al. 2000; Huang et al. 2006). If seeded onto dentin, some DPSCs are capable of generating new stem cells or multilineage differentiation into odontoblasts, adipocytes and neural-like cells. This stem cell behavior occurs following cryopreservation, signifying the potential use of frozen tissues for stem cell isolation (Zhang et al. 2006). Pulp cells can proliferate and differentiate into odontoblast-like cells processes, extending into dentinal tubules when in contact with chemo-mechanically treated dentine surface in an in vitro situation. This is a requirement for the secretion of new dentine (Huang et al. 2006).
Cellular Injury Associated with Organ Cryopreservation: Chemical Toxicity and Cooling Injury
John J. Lemasters, Constance Oliver in Cell Biology of Trauma, 2020
Organ cryopreservation is a frontier discipline both in cryobiology and in pathology. Cryopreservation refers to preservation at cryogenic temperatures, which for our present purposes will be considered any temperature below about -100°C. For organ cryopreservation to succeed, it is necesary that the organ survive low-temperature exposure per se, and it appears necessary for the organ to survive exposure to certain chemical agents (known generically as cryoprotective agents [CPAs] or cryoprotectants) at concentrations so high that they preclude ice formation during cooling.1 Aqueous solutions that do not freeze upon cooling eventually revert to the glassy state, a glass being a liquid the molecular motions of which have been largely arrested.2 This conversion to the glassy state is referred to as vitrification, and organ cryopreservation in the absence of ice is referred to as organ vitrification.
Hypoxic conditions promote a proliferative, poorly differentiated phenotype in COPD lung tissue progenitor cells in vitro
Published in Experimental Lung Research, 2023
Tina P. Dale, Michael D. Santer, Mohammed Haris, Wei Zuo, Nicholas R. Forsyth
To produce feeder layers for co-culture, 3T3-J2 cells (Kerafast, US) were expanded (maximum of 12 additional passages from receipt) in 4.5 g/L DMEM supplemented with 10% iron-supplemented bovine calf serum (Seradigm, US), (1% (v/v) NEAA, 2 mM L-glutamine (Lonza, UK), 100 IU/mL penicillin,100μg/mL streptomycin, and 0.25 μg/mL amphotericin B. Media was changed twice per week and cells were passaged enzymatically as necessary with 0.05% (w/v) trypsin/0.02% (w/v) EDTA. Cells were inactivated by culture in the presence of 10 μg/mL of mitomycin C (Tocris, UK) in culture media for 2 h, followed by 3 PBS washes, trypsinization, and cryopreservation until required. Cells were recovered from cryopreservation at a density of 1.5 x 104 cells/cm2 approximately 16–24 h before being needed.
Reproductive health in transgender and gender diverse individuals: A narrative review to guide clinical care and international guidelines
Published in International Journal of Transgender Health, 2023
Kenny Rodriguez-Wallberg, Juno Obedin-Maliver, Bernard Taylor, Norah Van Mello, Kelly Tilleman, Leena Nahata
Gender affirming hormone treatments and surgical interventions provided to transgender and gender diverse people to align their bodies with their gender identity may limit or alter future reproductive options to varying degrees. It is therefore highly recommended to discuss the risk of infertility inherent to these interventions, as clearly stated in the current guidelines for gender-affirming medical treatment from the World Professional Association for Transgender Health (WPATH) (Coleman et al., 2012) and the Endocrine Society (Hembree et al., 2017). For individuals facing treatments that can affect their fertility potential several options for fertility preservation (FP) have been developed. The most used and available at nearly all reproductive medicine clinics worldwide include the cryopreservation of embryos, oocytes, and sperm, which can be offered to adult patients. These methods may be also applicable to post-pubertal adolescents (Nahata et al., 2019; Rodriguez-Wallberg et al., 2019a). Research protocols for ovarian and testicular tissue cryopreservation have also been developed at some centers and these methods can be also applied in children (Borgström et al., 2020; Nahata et al., 2019; Rodriguez-Wallberg et al., 2019a, 2019b).
Human oocyte cryopreservation: revised evidence for practice
Published in Human Fertility, 2023
Virginia N. Bolton, Catherine Hayden, Michele Robinson, Dima Abdo, Angela Pericleous-Smith
Successful cryopreservation of living cells relies on preventing the formation of ice crystals that may cause cryodamage (Mazur, 1963) and minimising the toxic effects of exposure to cryoprotectant agents (Kleinhans & Mazur, 2007). With slow freezing, this is achieved through the gradual dehydration and permeation of cells with cryoprotectants through a combination of exposure to progressively increasing concentrations of cryoprotectants and controlled slow cooling. The relative lack of success of early attempts at slow freezing oocytes compared with embryos has been attributed to several characteristics that distinguish mammalian oocytes from embryos (Friedler et al., 1988), including relatively low permeability to cryoprotectants (Edashige & Kasai, 2016), low surface area:volume ratio and high water content (K. Goldman et al., 2016), and thus their greater susceptibility to cryo damage. With vitrification, cryodamage is reduced by rapid cooling combined with brief exposure to relatively high concentrations of cryoprotectants, so that ice crystal formation is prevented, and cells achieve a glass-like state (Nakagata, 1989). Based on the large body of evidence now available for the superior efficacy of vitrification for oocyte cryopreservation, slow freezing is no longer considered appropriate for routine use in clinical practice and will not be considered further in this guideline.
Related Knowledge Centers
- Cryoprotectant
- Tissue
- Trehalose
- Metabolism
- Cell Membrane
- Cell
- Liquid Nitrogen
- Osmotic Shock
- Freezing
- Sugar