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Semen cryopreservation

From Wikipedia, the free encyclopedia

Semen cryopreservation (commonly called sperm banking or sperm freezing) is a procedure to preserve sperm cells. Semen can be used successfully indefinitely after cryopreservation. For human sperm, the longest reported successful storage is 24 years.[1] It can be used for sperm donation where the recipient wants the treatment in a different time or place, or as a means of preserving fertility for men undergoing vasectomy or treatments that may compromise their fertility, such as chemotherapy, radiation therapy or surgery.

YouTube Encyclopedic

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  • Vitrification of ovarian tissue to preserve fertility
  • Andrology Laboratory, AMRI Medical Center, Kolkata, India

Transcription

[music] Dr. Silber: Melissa you flew up here from Houston. Melissa: Yes I did. Dr. Silber: But you grew up in St. Louis. Melissa: Mmmhmm. Coincidentally my family still lives here so that worked out very well. Dr. Silber: So you’re back home in a way. Melissa: Yes. Dr. Silber: All right. So you’re a schoolteacher and everything just seemed fine, but it’s been a rough month for you. Melissa: It has been. I got divorced earlier this month and I kind of thought that I just wasn’t paying attention to things that were maybe changing in my body. I was then diagnosed with stage 4 inflammatory breast cancer. Dr. Silber: So Dr. McKenzie, who was your fertility specialist, she knew that she wasn’t going to be able to stimulate you to retrieve eggs from your ovaries. Melissa: Right. Dr. Silber: Because we don’t want anything to raise that estrogen up. Melissa: Right. Dr. Silber: Until you’re cured. And then when you’re cured you’ll be able to have a baby without a problem. As long as you still have eggs. Melissa: Right. Dr. Silber: So the idea is to freeze your ovaries. And indeed we had many beautiful follicles frozen in her ovarian cortical tissue, and a thorough search of her ovaries showed no evidence of breast cancer metastasis, so we’ll be able to transplant her tissue back later after she’s cured. We expose both ovaries though a tiny little mini-lap using a mobius retractor, which is really not much more invasive than a laparoscopy. First we ask for a GV oocytes from the antral-follicles of the contralateral ovary, which is not going to be removed. The reason for this is some cancers will metastasize to the ovary, and we’ll have to be able to GV maturation in the future to be able to get them pregnant. Then the remaining ovary on the other side is removed in total, then aspiration of the GV oocytes from the remaining ovary on the bench In Vitro is performed. So that we have a lot of GV oocytes aspirated from both ovaries and one of the ovaries has actually been removed. Now in order to freeze GV oocytes, you have to remove half of the cumulus cells so that the vitrification solution an adequately penetrate the egg, and then the freezing is no different than we do for normal oocytes and embryos using the cryotop method developed by Kuwayama. Now the reason we save half the cumulus cells is so In Vitro maturation can be performed at a later date. Note that in order to have the fastest possible lowering of temperature it’s critical not to have a droplet, but to aspirate all extra fluid away from the egg before freezing. Thawing has to be even more rapid than freezing. At the same time that all the GV oocytes are being vitrified, we begin to resect thin 1-millimeter slices of ovarian cortex in preparation for ovarian cortex vitrification, which is a different technique. We use a special tissue microtome type device, which makes it very easy to get slices that are uniformly 1 millimeter in thickness, which is necessary for the rapid penetration of the cryoprotectant and for rapid temperature drop of the ovarian tissue at 23,000 degrees centigrade per minute. If you look at fresh human tissue pre-freeze and then compare it to post-freeze tissue, you find absolutely no difference and no damage caused by the vitrification process. We continue now to go through the entire cortex and find as many as 10 to 20 pieces or cortical tissue that we are now preparing in equilibrium solution, which is 7.5 percent DMSO and 7.5 percent ethylene glycol. Then place it in the vitrification solution that is 40 percent cryoprotectant and wait until all of the pieces of tissue drop to the bottom of the test tube. Now that we know that all of the vitrification media is completely penetrated throughout the tissue, we place it on a copper grid and allow all the extra fluid to come off. Then avoiding the [phonetic] effect we were able to dump it immediately into liquid nitrogen for rapid freeze at 23,000 degrees per minute. Then it is placed in closed storage using a Kitazato cryotissue closed storage system. The thaw must be done just as rapidly as the freezing. Placed immediately in 1.0 molar sucrose at 37 degrees followed by 0.5 molar sucrose for five minute at room temperature. The frozen human tissue post-vitrification is absolutely no different than the frozen tissue pre-vitrification, and no pathologist has ever been able to tell the difference between frozen thawed tissue with vitrification or the original tissue. Now we’re preparing to quilt these tissue strips together because we are going to transplant them back to the patient – back to her raw, ovarian medulla after the dead cortex has been removed. To make that operation easier, we go through a process In Vitro of quilting and suturing these thawed pieces of ovarian cortex together with 9-0 nylon under the microscope The next step is to remove the dead cortex from the inside two ovaries. This is from a woman who had a bone marrow transplant, multiple cycles of chemotherapy and radiation. Yet we found viable ovarian medulla with good bleeding. Despite her very tiny uterus, she conceived naturally and had a healthy baby after this surgery. The dead cortex was verified by histology to have not a single viable follicle in it, and now the thawed tissue is placed on the raw medullary and we’re preparing now to suture this graft down. It’s very important to do it in such a way with 9-0 nylon interrupted under the operating microscope that there are no micro hematomas forming underneath the graft, between the graft bed and the graft. This way we get very rapid vascularization and ironically, surprisingly, no egg loss. You’ve just seen the technique of vitrification to cryopreserve ovarian tissue developed first by Kagawa and Kuwayama and myself. And you’ve been able to see the difference between this and slow-freezing techniques. With slow-freezing technique, return of ovulation and menstruation normally requires four and a half to five and a half months. We’ve always found with vitrification, however, that return of ovulation and menstruation occurs by about two months, indicating absolutely no damage to either primordial or secondary follicles. So we think that from this point on, vitrification would be a preferred method of freezing ovarian tissue without any egg loss. [music][end]

Contents

Freezing

The most common cryoprotectant used for semen is glycerol (10% in culture medium). Often sucrose or other di-, trisaccharides are added to glycerol solution. Cryoprotectant media may be supplemented with either egg yolk or soy lecithin, with the two having no statistically significant differences compared to each other regarding motility, morphology, ability to bind to hyaluronate in vitro, or DNA integrity after thawing.[2]

Additional cryoprotectants can be used to increase sperm viability and fertility rates post-freezing. Treatment of sperm with heparin binding proteins prior to cryopreservation showed decreased cryoinjury and generation of ROS.[3] The addition of nerve growth factor as a cryoprotectant decreases sperm cell death rates and increased motility after thawing.[4] Incorporation of cholesterol into sperm cell membranes with the use of cyclodextrins prior to freezing also increases sperm viability.[5]

Semen is frozen using either a controlled-rate, slow-cooling method (slow programmable freezing or SPF) or a newer flash-freezing process known as vitrification. Vitrification gives superior post-thaw motility and cryosurvival than slow programmable freezing.[6]

Thawing

Thawing at 40 °C seems to result in optimal sperm motility. On the other hand, the exact thawing temperature seems to have only minor effect on sperm viability, acrosomal status, ATP content, and DNA.[7] As with freezing, various techniques have been developed for the thawing process, both discussed by Di Santo et al. (2012)[8]

Refreezing

In terms of the level of sperm DNA fragmentation, up to three cycles of freezing and thawing can be performed without causing a level of risk significantly higher than following a single cycle of freezing and thawing. This is provided that samples are refrozen in their original cryoprotectant and are not going through sperm washing or other alteration in between, and provided that they are separated by density gradient centrifugation or swim-up before use in assisted reproduction technology.[9]

Effect on quality

Some evidence suggests an increase in single-strand breaks, condensation and fragmentation of DNA in sperm after cryopreservation. This can potentially increase the risk of mutations in offspring DNA. Antioxidants and the use of well-controlled cooling regimes could potentially improve outcomes.[10]

In long-term follow-up studies, no evidence has been found either of an increase in birth defects or chromosomal abnormalities in people conceived from cryopreserved sperm compared with the general population.[10]

See also

References

  1. ^ Planer NEWS and Press Releases > Child born after 22 year semen storage using Planer controlled rate freezer 14/10/2004
  2. ^ Reed ML; et al. (2009). "Soy lecithin replaces egg yolk for cryopreservation of human sperm without adversely affecting postthaw motility, morphology, sperm DNA integrity, or sperm binding to hyaluronate". Fertility and Sterility. 92 (5): 1787–1790. doi:10.1016/j.fertnstert.2009.05.026.
  3. ^ Patel, M., Gandotra, V. K., Cheema, R. S., Bansal, A. K., & Kumar, A. (2016). Seminal Plasma Heparin Binding Proteins Improve Semen Quality by Reducing Oxidative Stress during Cryopreservation of Cattle Bull Semen. Asian-Australasian Journal of Animal Sciences, 29(9), 1247–1255.
  4. ^ Saeednia S, Bahadoran H, Amidi F, Asadi MH, Naji M, Fallahi P, Nejad NA (2015). "Nerve growth factor in human semen: Effect of nerve growth factor on the normozoospermic men during cryopreservation process". Iranian Journal of Basic Medical Sciences. 18 (3): 292–299.
  5. ^ Purdy PH, Graham JK (2004a). "Effect of cholesterol-loaded cyclodextrin on the cryosurvival of bull sperm". Cryobiology. 48: 36–45. doi:10.1016/j.cryobiol.2003.12.001.
  6. ^ Vutyavanich T, Piromlertamorn W, Nunta S (April 2010). "Rapid freezing versus slow programmable freezing of human spermatozoa". Fertil. Steril. 93 (6): 1921–8. doi:10.1016/j.fertnstert.2008.04.076. PMID 19243759.
  7. ^ Calamera JC, Buffone MG, Doncel GF, et al. (December 2008). "Effect of thawing temperature on the motility recovery of cryopreserved human spermatozoa". Fertil. Steril. 93 (3): 789–794. doi:10.1016/j.fertnstert.2008.10.021. PMID 19059590.
  8. ^ Di Santo M, Tarozzi N, Nadalini M, and Borini A (2012). "Human Sperm Cryopreservation: Update on Techniques, Effect on DNA Integrity, and Implications for ART (Review)". Adv. Urology. 2012: 854837. doi:10.1155/2012/854837. PMC 3238352. PMID 22194740.
  9. ^ Thomson LK, Fleming SD, Barone K, Zieschang JA, Clark AM (March 2010). "The effect of repeated freezing and thawing on human sperm DNA fragmentation". Fertil Steril. 93 (4): 1147–1156. doi:10.1016/j.fertnstert.2008.11.023. PMID 19135665.
  10. ^ a b Kopeika, J.; Thornhill, A.; Khalaf, Y. (2014). "The effect of cryopreservation on the genome of gametes and embryos: principles of cryobiology and critical appraisal of the evidence". Human Reproduction Update. 21 (2): 209–227. doi:10.1093/humupd/dmu063. ISSN 1355-4786. PMID 25519143.
This page was last edited on 17 August 2018, at 09:19
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