Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2003-5-28
pubmed:abstractText
Embryo freezing has been a successful practice, but oocyte cryopreservation formerly achieved poorer results. This was mainly due to low rates of survival, fertilization, and development. The major dissimilarities for oocytes to embryos are the character of the plasma membrane, the presence of cortical granules, at the metaphase of meiosis II with the spindle system. In addition, the oocytes must be fertilized by sperm at the appropriate time. To improve the survival rate, a refined slow freezing method with increased sucrose concentration would dehydrate oocytes more sufficiently. Vitrification is another approach to prevent ice crystal formation. Intracytoplasmic sperm injection is used to overcome possible zona hardening from the release of cortical granules. The microtubules of meiotic spindles are vulnerable to the thermal changes and would depolymerize. Cryopreserved oocytes exhibited serious disturbances of the microtubules immediately after thawing. Fertilization of oocytes with disorganized spindles could lead to chromosomal aneuploidy, digyny, and arrest of cleavage. After incubation, the microtubules would repolymerize in a time-dependent way. Normal fertilization and development of cryopreserved oocytes improved after appropriate incubation and timing of insemination, compatible with recovery of the spindles. With the improvement of survival, fertilization, and cleavage, oocyte cryopreservation would gain an imperative role.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
202
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
101-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Effects of cryopreservation on meiotic spindles of oocytes and its dynamics after thawing: clinical implications in oocyte freezing--a review article.
pubmed:affiliation
Department of Obstetrics and Gynecology, College of Medicine and University Hospital, National Taiwan University, No. 7 Chung-Shan South Road, Taipei, Taiwan.
pubmed:publicationType
Journal Article, In Vitro, Review