Isachenko, VladimirIsachenko, EvgeniaMallmann, PeterRahimi, Gohar...
6页查看更多>>摘要：Cryopreservation and re-transplantation of ovarian tissue after anticancer treatment is important medical technology. Today, during a pandemic, the risk of contamination of transplanted cells with SARS-CoV-2 virus is extremely high. Data about cryo-resistance (virulence and/or infectivity) of SARS-CoV-2 are limited. Analysis and systematization of literature data allow us to draw the following conclusions: 1) The cytoplasmic membrane of somatic cell, like envelope of corona viruses, consists of lipid bilayer and this membrane, like envelope of corona virus, contains membrane proteins. Thus, we can consider the cytoplasmic membrane of an ordinary somatic cell as a model of the envelope membrane of SARS-CoV-2. It is expected that the response of the virus to cryopreservation is similar to that of a somatic cell. SARS-CoV-2 is more poor-water and more protein-rich than somatic cell, and this virus is much more cryo-resistant. 2) The exposure of somatic cells at low positive temperatures increases a viability of these cells. The safety of the virus is also in direct proportion to the decrease in temperature: the positive effect of low temperatures on SARS-CoV-2 virus has been experimentally proven. 3) Resistance of SARS-CoV-2 to cryoprotectant-free cryopreservation is extremely high. The high viability rate of SARS-CoV-2 after freezing-drying confirms its high cryo-resistance. 4) The risk of SARS-CoV-2 infection after transplantation of cryopreserved ovarian tissues that have been contaminated with this virus, increases significantly. Our own experimental data on the increase in the viability of cancer cells after cryopreservation allow us to formulate a hypothesis about increasing of viability (virulence and/or infectivity) of SARS-CoV-2 virus after cryopreservation.
原文链接:
NSTL
Elsevier
Isachenko, VladimirIsachenko, EvgeniaMallmann, PeterRahimi, Gohar...
6页查看更多>>摘要：Cryopreservation and re-transplantation of ovarian tissue after anticancer treatment is important medical technology. Today, during a pandemic, the risk of contamination of transplanted cells with SARS-CoV-2 virus is extremely high. Data about cryo-resistance (virulence and/or infectivity) of SARS-CoV-2 are limited. Analysis and systematization of literature data allow us to draw the following conclusions: 1) The cytoplasmic membrane of somatic cell, like envelope of corona viruses, consists of lipid bilayer and this membrane, like envelope of corona virus, contains membrane proteins. Thus, we can consider the cytoplasmic membrane of an ordinary somatic cell as a model of the envelope membrane of SARS-CoV-2. It is expected that the response of the virus to cryopreservation is similar to that of a somatic cell. SARS-CoV-2 is more poor-water and more protein-rich than somatic cell, and this virus is much more cryo-resistant. 2) The exposure of somatic cells at low positive temperatures increases a viability of these cells. The safety of the virus is also in direct proportion to the decrease in temperature: the positive effect of low temperatures on SARS-CoV-2 virus has been experimentally proven. 3) Resistance of SARS-CoV-2 to cryoprotectant-free cryopreservation is extremely high. The high viability rate of SARS-CoV-2 after freezing-drying confirms its high cryo-resistance. 4) The risk of SARS-CoV-2 infection after transplantation of cryopreserved ovarian tissues that have been contaminated with this virus, increases significantly. Our own experimental data on the increase in the viability of cancer cells after cryopreservation allow us to formulate a hypothesis about increasing of viability (virulence and/or infectivity) of SARS-CoV-2 virus after cryopreservation.
原文链接:- NSTL
- Elsevier
El Cury-Silva, TaynnNunes, Monique E. G.Casalechi, MairaComim, Fabio, V...
8页查看更多>>摘要：Studies on the cryopreservation of ovarian tissue usually compare slow freezing versus vitrification and aim to optimize protocols, evaluate combinations or concentrations of cryoprotectant agents (CPAs), exposure time, and the addition of synthetic polymers. This systematic review aimed to identify the different CPAs used for the vitrification of human or primate ovarian tissue and to compare their results in terms of follicular survival and functional preservation. We searched Pubmed and EMBASE for randomized clinical trials or cohort studies comparing CPAs for human and/or primate ovarian vitrification. The highest rate of morphologically normal follicles after cryopreservation was 98% and was obtained with a combination of 27% ethylene glycol (EG) plus 27% glycerol, in addition to non-permeable synthetic polymers. The use of dimethyl sulfoxide (DMSO) in relatively low concentrations combined with EG and other CPAs yielded more than 90% of intact follicles after vitrification. The methods and outcomes varied largely among studies, making it difficult to combine their results. While there is no definite answer to what is the best combination of CPAs for vitrification of human ovarian tissue, the data reviewed here suggest that current vitrification techniques are able to preserve the integrity of most follicles.
原文链接:- NSTL
- Elsevier
El Cury-Silva, TaynnNunes, Monique E. G.Casalechi, MairaComim, Fabio, V...
8页查看更多>>摘要：Studies on the cryopreservation of ovarian tissue usually compare slow freezing versus vitrification and aim to optimize protocols, evaluate combinations or concentrations of cryoprotectant agents (CPAs), exposure time, and the addition of synthetic polymers. This systematic review aimed to identify the different CPAs used for the vitrification of human or primate ovarian tissue and to compare their results in terms of follicular survival and functional preservation. We searched Pubmed and EMBASE for randomized clinical trials or cohort studies comparing CPAs for human and/or primate ovarian vitrification. The highest rate of morphologically normal follicles after cryopreservation was 98% and was obtained with a combination of 27% ethylene glycol (EG) plus 27% glycerol, in addition to non-permeable synthetic polymers. The use of dimethyl sulfoxide (DMSO) in relatively low concentrations combined with EG and other CPAs yielded more than 90% of intact follicles after vitrification. The methods and outcomes varied largely among studies, making it difficult to combine their results. While there is no definite answer to what is the best combination of CPAs for vitrification of human ovarian tissue, the data reviewed here suggest that current vitrification techniques are able to preserve the integrity of most follicles.
原文链接:- NSTL
- Elsevier
Galarza, Diego A.Landi, GabrielaMejia, EdissonSamaniego, Jorge X....
7页查看更多>>摘要：This study was aimed to assess the effectiveness of two methods for cryopreservation of dog epididymal spermatozoa, one by conventional freezing (CF) with shortening both equilibration and cooling times, and the other by ultra-rapid freezing (URF) with nonpermeable cryoprotectant. Sixty epididymides were recovered from thirty orchiectomized adult dogs and the sperm samples were retrieved by retrograde flushing using TCG-EY (tris, citric acid, glucose + 20% egg yolk) extender and then 20 pools were conformed. Each pool was divided into 2 aliquots and then cryopreserved by CF and URF methods respectively. The CF method maintained the cooled-pool samples for 2h (1h without and 1h with 5% glycerol) and then were frozen by liquid nitrogen (LN2) vapors for 2 min. The URF method cryopreserved the cooled-pool samples using TCG-EY+250 mM sucrose, equilibrating during 30 min (5 degrees C) and submerging 30-mu L drops directly in LN2. The results showed that the URF method produced a lower percentage of total and progressive motilities and acrosome integrity (P < 0.05) than the CF method. However, the kinetic variables (curvilinear and straight-line velocities, straightness, linearity, wobble, amplitude of lateral head displacement, and beat-cross frequency) and plasma membrane integrity did not differ (P > 0.05) between both cryopreservation methods. Unlike the URF method, the width, area and perimeter of sperm head were reduced after the CF method (P < 0.05). In conclusion, despite the low motility achieved after the ultra-rapid freezing method, the similar values of kinetic, viability and head morphometric dimensions to those obtained after conventional freezing, suggest that ultra-rapid freezing with sucrose may be a useful alternative for the cryopreservation of canine epididymal sperm.
原文链接:- NSTL
- Elsevier
Galarza, Diego A.Landi, GabrielaMejia, EdissonSamaniego, Jorge X....
7页查看更多>>摘要：This study was aimed to assess the effectiveness of two methods for cryopreservation of dog epididymal spermatozoa, one by conventional freezing (CF) with shortening both equilibration and cooling times, and the other by ultra-rapid freezing (URF) with nonpermeable cryoprotectant. Sixty epididymides were recovered from thirty orchiectomized adult dogs and the sperm samples were retrieved by retrograde flushing using TCG-EY (tris, citric acid, glucose + 20% egg yolk) extender and then 20 pools were conformed. Each pool was divided into 2 aliquots and then cryopreserved by CF and URF methods respectively. The CF method maintained the cooled-pool samples for 2h (1h without and 1h with 5% glycerol) and then were frozen by liquid nitrogen (LN2) vapors for 2 min. The URF method cryopreserved the cooled-pool samples using TCG-EY+250 mM sucrose, equilibrating during 30 min (5 degrees C) and submerging 30-mu L drops directly in LN2. The results showed that the URF method produced a lower percentage of total and progressive motilities and acrosome integrity (P < 0.05) than the CF method. However, the kinetic variables (curvilinear and straight-line velocities, straightness, linearity, wobble, amplitude of lateral head displacement, and beat-cross frequency) and plasma membrane integrity did not differ (P > 0.05) between both cryopreservation methods. Unlike the URF method, the width, area and perimeter of sperm head were reduced after the CF method (P < 0.05). In conclusion, despite the low motility achieved after the ultra-rapid freezing method, the similar values of kinetic, viability and head morphometric dimensions to those obtained after conventional freezing, suggest that ultra-rapid freezing with sucrose may be a useful alternative for the cryopreservation of canine epididymal sperm.
原文链接:- NSTL
- Elsevier
Ostler, TimothyWoolley, Thomas E.Swann, KarlThomson, Andrew...
10页查看更多>>摘要：Vitrification is the most common method of cryopreservation of gametes in fertility clinics due to its improved survival rates compared to slow freezing techniques. For the Open Cryotop (R) vitrification device, the number of oocytes, or embryos, mounted onto a single device can vary. In this work, a mathematical model is developed for the cooling of oocytes and embryos (samples). The model is solved computationally, to investigate whether varying the number of samples mounted onto the Open Cryotop (R) affects the cooling rates, and consequently the survival rates, of vitrified samples. Several realistic spatial arrangements of samples are examined, determining their temperature over time. In this way we quantify the effect of spatial arrangement on the cooling rate. Our results indicate that neither the spatial arrangement nor the number of mounted samples has a large effect on cooling rates, so long as the volume of the cryoprotectant remains minimal. The time taken for cooling is found to be on the order of half a second, or less, regardless of the spatial arrangement or number of mounted samples. Hence, rapid cooling can be achieved for any number or arrangement of samples, as long as device manufacturer guidelines are adhered to.
原文链接:- NSTL
- Elsevier
Ostler, TimothyWoolley, Thomas E.Swann, KarlThomson, Andrew...
10页查看更多>>摘要：Vitrification is the most common method of cryopreservation of gametes in fertility clinics due to its improved survival rates compared to slow freezing techniques. For the Open Cryotop (R) vitrification device, the number of oocytes, or embryos, mounted onto a single device can vary. In this work, a mathematical model is developed for the cooling of oocytes and embryos (samples). The model is solved computationally, to investigate whether varying the number of samples mounted onto the Open Cryotop (R) affects the cooling rates, and consequently the survival rates, of vitrified samples. Several realistic spatial arrangements of samples are examined, determining their temperature over time. In this way we quantify the effect of spatial arrangement on the cooling rate. Our results indicate that neither the spatial arrangement nor the number of mounted samples has a large effect on cooling rates, so long as the volume of the cryoprotectant remains minimal. The time taken for cooling is found to be on the order of half a second, or less, regardless of the spatial arrangement or number of mounted samples. Hence, rapid cooling can be achieved for any number or arrangement of samples, as long as device manufacturer guidelines are adhered to.
原文链接:- NSTL
- Elsevier
Kovalov, Gennadiy O.Shustakova, Galyna, VGordiyenko, Eduard YuFomenko, Yuliya, V...
7页查看更多>>摘要：The purpose of this study was to assess the possibilities of intraoperative control of the current parameters of frozen biological tissues in the cryoablation area, including the instant location of primary necrosis isotherm, based on the dynamics of thermal fields on skin surface. Cryoablation of skin was performed in 30 rats with exposure durations of 0.5, 1 and 2 min. The contact cryoprobe actively cooled with liquid nitrogen was used. The dynamics of animal's skin thermal field during freeze/thaw cycle was quantitatively controlled by the original infrared camera with an extended range of measurable temperatures. The obtained by us ratio of the maximal diameters of primary necrosis and ice spots was 0.64 +/- 0.03 for cryoexposure durations of 0.5 and 1 min. During thawing, a quasi-stable stage was observed both in the dynamics of ice spot diameters and their temperature distribution. The effect is presumably associated with structural rearrangements of ice in the frozen tissue volume. The results indicate that thermal imaging can be effectively used for quantitative control of freezing and warming of biological tissues in vivo, including current control of the position of necrotic and cryoscopic isotherms, distortion of their thermal symmetry, thermal response of other skin areas, etc.
原文链接:- NSTL
- Elsevier
Kovalov, Gennadiy O.Shustakova, Galyna, VFomenko, Yuliya, VGlushchuk, Mykola, I...
7页查看更多>>摘要：The purpose of this study was to assess the possibilities of intraoperative control of the current parameters of frozen biological tissues in the cryoablation area, including the instant location of primary necrosis isotherm, based on the dynamics of thermal fields on skin surface. Cryoablation of skin was performed in 30 rats with exposure durations of 0.5, 1 and 2 min. The contact cryoprobe actively cooled with liquid nitrogen was used. The dynamics of animal's skin thermal field during freeze/thaw cycle was quantitatively controlled by the original infrared camera with an extended range of measurable temperatures. The obtained by us ratio of the maximal diameters of primary necrosis and ice spots was 0.64 +/- 0.03 for cryoexposure durations of 0.5 and 1 min. During thawing, a quasi-stable stage was observed both in the dynamics of ice spot diameters and their temperature distribution. The effect is presumably associated with structural rearrangements of ice in the frozen tissue volume. The results indicate that thermal imaging can be effectively used for quantitative control of freezing and warming of biological tissues in vivo, including current control of the position of necrotic and cryoscopic isotherms, distortion of their thermal symmetry, thermal response of other skin areas, etc.
原文链接:- NSTL
- Elsevier
