1.Expert consensus on the vitrification of human oocytes and embryos.
Da LI ; Yingzhuo GAO ; Rong LI
Chinese Medical Journal 2023;136(23):2773-2775
2.Droplet freeze-thawing system based on solid surface vitrification and laser rewarming.
Wenxin ZHU ; Ping'an PAN ; Yonghua HUANG ; Wei CHEN ; Sha HAN ; Zheng LI ; Jinsheng CHENG
Journal of Biomedical Engineering 2023;40(5):973-981
Ultra-rapid cooling and rewarming rate is a critical technical approach to achieve ice-free cells during the freezing and melting process. A set of ultra-rapid solid surface freeze-thaw visualization system was developed based on a sapphire flim, and experiments on droplet freeze-thaw were carried out under different cryoprotectant components, volumes and laser energies. The results showed that the cooling rate of 1 μL mixed cryoprotectant [1.5 mol/L propylene glycol (PG) + 1.5 mol/L ethylene glycol (EG) + 0.5 mol/L trehalose (TRE)] could be 9.2×10 3 °C/min. The volume range of 1-8 μL droplets could be vitrified. After comparing the proportions of multiple cryoprotectants, the combination of equal proportion mixed permeability protectant and trehalose had the best vitrification freezing effect and more uniform crystallization characteristics. During the rewarming operation, the heating curve of glassy droplets containing gold nanoparticles was measured for the first time under the action of 400-1 200 W laser power, and the rewarming rate was up to the order of 10 6 °C/min. According to the droplet images of different power rewarming processes, the laser power range for ice-free rewarming with micron-level resolution was clarified to be 1 400-1 600 W. The work of this paper simultaneously realizes the ultra-high-speed temperature ramp-up, transient visual observation and temperature measurement of droplets, providing technical means for judging the ice free droplets during the freeze-thaw process. It is conducive to promoting the development of ultra-rapid freeze-thaw technology for biological cells and tissues.
Freezing
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Vitrification
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Cryopreservation/methods*
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Trehalose
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Gold
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Rewarming
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Metal Nanoparticles
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Cryoprotective Agents
;
Lasers
3.Intrinsically disordered proteins (IDPs) and the impact on cell stress resistance.
Ning YAN ; Hongxing LI ; Longhao WU ; Shuo YANG ; Lujiang HAO ; Xiaoming BAO
Chinese Journal of Biotechnology 2022;38(4):1490-1505
Intrinsically disordered proteins (IDPs) are proteins or protein regions that fail to get folded into definite three-dimensional structures but participate in various biological processes and perform specific functions. Defying the traditional protein "sequence-structure-function" paradigm, they enrich the protein "structure-function" diversity. Ubiquitous in organisms, they show extreme hydrophilicity, charged amino acids, and highly repetitive amino acid sequences, with simple arrangement. As a result, they feature highly variable binding affinities and high coordination, which facilitate their functions. IDPs play an important role in cell stress response, which can improve the tolerance to a variety of stresses, such as freezing, high salt, heat shock, and desiccation. In this study, we briefed the characteristics, classifications, and identification of IDPs, summarized the molecular mechanism in improving cell stress resistance, and described the potential applications.
Freezing
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Intrinsically Disordered Proteins/metabolism*
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Protein Conformation
4.Effects of vitrification and cryostorage duration on single-cell RNA-Seq profiling of vitrified-thawed human metaphase II oocytes.
Ying HUO ; Peng YUAN ; Qingyuan QIN ; Zhiqiang YAN ; Liying YAN ; Ping LIU ; Rong LI ; Jie YAN ; Jie QIAO
Frontiers of Medicine 2021;15(1):144-154
Oocyte cryopreservation is widely used for clinical and social reasons. Previous studies have demonstrated that conventional slow-freezing cryopreservation procedures, but not storage time, can alter the gene expression profiles of frozen oocytes. Whether vitrification procedures and the related frozen storage durations have any effects on the transcriptomes of human metaphase II oocytes remain unknown. Four women (30-32 years old) who had undergone IVF treatment were recruited for this study. RNA-Seq profiles of 3 fresh oocytes and 13 surviving vitrified-thawed oocytes (3, 3, 4, and 3 oocytes were cryostored for 1,2, 3, and 12 months) were analyzed at a single-cell resolution. A total of 1987 genes were differentially expressed in the 13 vitrified-thawed oocytes. However, no differentially expressed genes were found between any two groups among the 1-, 2-, 3-, and 12-month storage groups. Further analysis revealed that the aberrant genes in the vitrified oocytes were closely related to oogenesis and development. Our findings indicated that the effects of vitrification on the transcriptomes of mature human oocytes are induced by the procedure itself, suggesting that long-term cryostorage of human oocytes is safe.
Adult
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Cryopreservation
;
Female
;
Humans
;
Metaphase
;
Oocytes
;
RNA-Seq
;
Vitrification
5.Effects of Vitrification with Self-made Carriers and Slow Programmed Freezing on Ovarian Tissue of Sheep.
Yan Ting CUI ; Lu Kai YANG ; Jin LIU ; Yi Long HAN ; Chao CHEN ; Xiao Hui DENG ; Li Gang JIANG
Acta Academiae Medicinae Sinicae 2021;43(2):193-198
Objective To investigate the effects of self-made carriers on the cryopreservation of ovarian tissue of sheep. Methods Thirty-two ovaries were randomly assigned to fresh group,programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group.The morphology,proliferation,apoptosis,and estrogen level of the ovarian tissue in each group were observed. Results After cryopreservation,the morphology normal rate of the primordial follicles in programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group were 74.2%,72.8%,and 72.3%,respectively,lower than that(83.7%)in the fresh group(χ
Animals
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Cryopreservation
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Female
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Freezing
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Ovarian Follicle
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Ovary
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Sheep
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Vitrification
6.Stability of IgE in Postmortem Plasma and Hemolyzed Samples.
Tian Qi WANG ; Tian Fang WANG ; Yu Qing JIA ; Zhi Peng CAO ; Bao Li ZHU
Journal of Forensic Medicine 2021;37(1):11-14
Objective To investigate the stability of IgE in postmortem plasma and hemolyzed samples under different storage conditions and freezing-thawing. Methods Thirty nine cardiac blood samples were collected from non-frozen corpses with the postmortem interval of less than 48 hours, including 20 plasma samples and 19 hemolyzed samples taken from whole blood. The samples were stored at -20 ℃, 4 ℃ and 25 ℃ for 28 d and at -80 ℃ for 1 year to evaluate the stability of IgE under different storage conditions. Repeated freezing-thawing treatment was conducted for 5 times to explore the stability of IgE in postmortem plasma and hemolyzed samples. IgE concentration in plasma and hemolyzed samples was detected by electroluminescence before and after treatment. Results The degradation rates of IgE in plasma samples under the three storage conditions, -20 ℃, 4 ℃ and 25 ℃ were close. After 28 d, the mean value was about 15%, the degradation speed of IgE in hemolyzed samples was faster than that of plasma under the same condition (P<0.05) and the degradation rate was faster than other two conditions under 25 ℃ (P<0.05). The differences in the concentration of plasma samples after freezing at -80 ℃ for 1 year and that before freezing had no statistical significance ( P>0.05), while the concentration of hemolyzed samples was degraded after freezing at -80 ℃ for 1 year (P<0.05). The differences between the detection results of plasma and hemolyzed samples after repeated freezing-thawing for 5 times and that before freezing-thawing showed no statistical significance ( P>0.05). Conclusion IgE has good freezing-thawing stability in postmortem plasma and hemolyzed samples. Stability of IgE is better in postmortem plasma samples than hemolyzed samples, thus it is recommended to separate plasma from postmortem blood samples as soon as possible in forensic practice.
Autopsy
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Forensic Medicine
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Freezing
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Immunoglobulin E
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Plasma
7.Corneal Collagen Cross-linking for Corneal Ulcer from Moraxella Group
Journal of the Korean Ophthalmological Society 2020;61(2):200-204
PURPOSE: To report a case of corneal collagen cross-linking for corneal ulcer caused by the Moraxella group.CASE SUMMARY: A 77-year-old male had decreased visual acuity for several days in his right eye. The patient showed severe stromal ring infiltrates with a corneal epithelial defect measuring (5.0 × 7.0 mm), a corneal endothelial plaque, and a hypopyon measuring less than 1.0 mm in height in the anterior chamber of the right eye. There was no abnormal finding in the right eye using B-scan ultrasonography. Before starting treatment, a corneal culture was conducted. The culture tests showed the presence of the Moraxella group. Because the patient was diagnosed with a corneal ulcer caused by the Moraxella group, corneal collagen cross-linking (CXL) was performed. The antimicrobial susceptibility test confirmed that this Moraxella group was sensitive to ceftazidime, so the patient was treated with 5% ceftazidime eye drops and 0.5% moxifloxacin eye drops every 2 hours for 9 months after corneal collagen CXL. The uncorrected visual acuity was 0.1 in the right eye, and there was almost no corneal stromal melting on anterior segment optical coherence tomography.CONCLUSIONS: This is the first known case of a corneal ulcer, in the Republic of Korea, caused by the Moraxella group and treated with corneal collagen CXL. Corneal collagen CXL should be considered as a surgical treatment for patients who have an impending corneal perforation due to a corneal ulcer because it is a simple procedure and causes fewer serious complications than other treatments.
Aged
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Anterior Chamber
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Ceftazidime
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Collagen
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Cornea
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Corneal Perforation
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Corneal Ulcer
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Freezing
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Humans
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Male
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Moraxella
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Ophthalmic Solutions
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Republic of Korea
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Tomography, Optical Coherence
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Ultrasonography
;
Visual Acuity
8.Pregnancy outcomes of the first thawing cycle in "freeze-all" strategy of infertility patients with fever during oocyte recruitment: a matched-pair study.
Ming-Mei LIN ; Zi-Ru NIU ; Hua ZHANG ; Rong LI
Chinese Medical Journal 2020;134(7):800-805
BACKGROUND:
It is currently unknown whether patients with a fever after controlled ovulation during egg retrieval could increase the risk of pelvic infection or not, and fever itself may affect endometrial receptivity or embryo quality with poor pregnancy outcomes. The aim of this study was to analyze the outcomes of patients with fever during oocyte retrieval after the first frozen-thawed embryo transfer (FET) cycle.
METHODS:
This was a 1:3 retrospective paired study matched for age. In this study, 58 infertility patients (Group 1) had a fever during the control ovulation, and the time of the oocyte retrieval was within 72 hours, they underwent ovum pick up and whole embryo freezing ("freeze-all" strategy). The control subjects (Group 2) are 174 patients matched for age who underwent whole embryo freezing for other reasons. The baseline characteristics, clinical data of ovarian stimulation, and outcomes, such as the clinical pregnancy rate, ongoing clinical pregnancy rate were compared between the two groups in the subsequent FET cycle.
RESULTS:
All patients had no pelvic inflammatory disease after oocyte retrieval. Anti-Mullerian hormone (AMH) levels (4.2 vs. 2.2, P <0.001) were higher in group 2, and the number of oocytes retrieved, and fertilization rate were lower in group 1 (P < 0.001), but the endometrial thickness, the number of embryo transfers, and the type of luteal support supplementation were similar between the two groups. Regarding pregnancy outcomes in the subsequent FET cycle, the implantation rate, clinical pregnancy rate, early spontaneous rate, ectopic pregnancy rate, and ongoing pregnancy rate were all not significantly different. Further regression analyses showed that the clinical pregnancy rate and ongoing pregnancy rate were also not significantly different.
CONCLUSIONS
Transvaginal ultrasound-guided follicular puncture for oocyte retrieval is a safe and minimally invasive method for patients with fever. Moreover, the fever had almost no effect on embryo quality.
Cryopreservation
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Female
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Fertilization in Vitro
;
Freezing
;
Humans
;
Infertility
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Oocyte Retrieval
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Oocytes
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Ovulation Induction
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Pregnancy
;
Pregnancy Outcome
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Pregnancy Rate
;
Retrospective Studies
9."High" on Muscle Spray - Ethyl Chloride Abuse.
Annals of the Academy of Medicine, Singapore 2019;48(2):67-68
Anesthetics, Local
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chemistry
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pharmacology
;
toxicity
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Central Nervous System
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drug effects
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Ethyl Chloride
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chemistry
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pharmacology
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toxicity
;
Humans
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Inhalation
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Male
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Medical History Taking
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Neurologic Examination
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Patient Care Management
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methods
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Psychotropic Drugs
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chemistry
;
pharmacology
;
toxicity
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Substance-Related Disorders
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etiology
;
physiopathology
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psychology
;
therapy
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Treatment Outcome
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Volatilization
;
Young Adult
10.Optimization of preparation of rat kidney decellularized scaffold by combining freeze-thawing with perfusion.
Dong HU ; Deying ZHANG ; Bo LIU ; Yu ZHOU ; Yihang YU ; Lianju SHEN ; Chunlan LONG ; Xing LIU ; Tao LIN ; Dawei HE ; Guanghui WEI
Chinese Journal of Biotechnology 2019;35(2):307-318
We explored the improved method to prepare decellularized kidney scaffold and provide experimental basis for kidney tissue engineering and renal pathology and toxicology in vitro research. We perfused rat kidneys with PBS (group control) and prepared the decellularized kidney scaffolds with sodium dodecyl sulfate (SDS) (group S), Triton X-100 combined with SDS (group TS), and Triton X-100 combined with SDS after repeated freezing and thawing (group FTS) in different flow velocity. Meanwhile we measured their fluid distributions and vascular resistance. We examined the degree of decellularization of acellular scaffolds by HE, DAPI staining and DNA quantification. We examined the retention of main composition and structural integrity of decellularized scaffolds by Masson, PAS and immunohistochemical staining. We also detected the ultrastructure, cytotoxicity and the level of growth factor of the scaffolds by scanning electron microscope, MTT and ELISA, respectively. The results showed that the time of decellularization in group FTS was less than that in group S and TS. The vascular resistance of scaffolds decellularized at 10 mL/min flow velocity was lower. The fluid distribution in groups S, TS and FTS was different from that in control group. No residual cell was detected by HE and DAPI staining. DNA content was less than 50 ng/mg. Masson, PAS and immunohistochemical staining results showed that there was extracellular collagen, polysaccharide, type I collagen, type IV collagen, fibronectin and laminin in the decellularized scaffolds, and the scanning electron microscope result showed the scaffolds had the honeycomb structure. The cytotoxicity level of decellularized scaffolds was between grade 0 to 1. The level of VEGF, EGF, IGF-1 and PDGF-BB in group FTS were significantly higher than those in group S and TS. In concluding, combining freeze-thawing with perfusion can produce more ideal and effective whole organ decellularized scaffold of rat kidney, and make a foundation for the study of kidney tissue engineering and in vitro pathology and toxicology of kidney.
Animals
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Collagen
;
Extracellular Matrix
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Freezing
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Kidney
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Perfusion
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Rats
;
Tissue Engineering
;
Tissue Scaffolds

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