Embryo quality

Kraft mill using 100% chlorine dioxide New and old wood pulp bleaching employing various bleach sequences Coastal fish community Mesocosm and fish biomarker tests High levels of mortality and low embryo quality Elemental chlorine containing bleach sequence, CEHDED was the most toxic Sandstrom, 1994 [25] Tana et ah, 1994 [26]... 

Typical doses are in the range of 2.5-5 i.u. per mouse. Optimal dose varies by strain, age, and weight of the mouse. Extending the oocyte collection window beyond 14 h post-hCG may reduce fertilization rates and compromise embryo quality due to oocyte aging. 

In order to reduce the risk of changes in temperature and pH, oocyte collection should take no more than 5 min from euthanasia to oocyte collection (i.e., practice). Typically cervical dislocation is used to prevent possible exposure to agents that may affect oocyte or embryo quality and to reduce the time from euthanasia to oocyte collection. 

The use of a low O2 culture environment may not improve fertilization rate, but appears to improve embryo quality (20,21). 

Embryo quality is routinely used in IVF laboratories to assess which embryo(s) have the best chance of implanting and therefore need to be transferred, and embryo quality is correlated with pregnancy (S7, S25). 

The rate of cleavage during the first 2 days after fertilization is not a reliable prognosticator for embryo quality (P8). 

Blastocyst formation is correlated with age and pregnancy (W5). This is further evidence that the negative effect that age has on treatment outcome has to do with oocyte and embryo quality. 

Further improvements in embryo quality are achieved by using lower levels of 2,4-D for induction of embryo formation. By treating alfalfa cultures with 10 uM 2,4-D (instead of 50 uM) a 50% increase in embryo conversion was achieved (4). Embryos treated in this manner were morphologically more similar to zygotic embryos than were those produced after a high 2,4-D treatment. Furthermore, the biochemistry of the improved-quality embryos was altered. When the level of embryo-specific IIS storage protein was compared in 10 and 50 uM... 

Low 2,4-D treated embryos accumulated 2.4 ug each of the IIS protein found in alfalfa seed, while the 50 uM-treated embryos accumulated less than 20 ng each (Figure 4). This result indicates that the level of storage protein accumulation is related to normalization of embryo development and may represent a useful assay to assess somatic embryo quality (4). The maxiumum level of protein accumulation is less than 107o of the level expected for alfalfa seed, however, suggesting that there is additional room for improvement in somatic embryo quality. 

LIN M H, Kuo-KUANG L R, LI s H, Lu c H, SUN F J and Hwu Y M (2008) Sperm chromatin structure assay parameters are not related to fertilization rates, embryo quality, and pregnancy rates in in vitro fertilization and intracytoplasmic sperm injection, but might be related to spontaneous abortion rates. Fertil Steril, 90,352-359. 

Embryo quality Couples undergoing IVF 54 Blood Low quality embryos associated with unconjugated BPA in males Bloom et al. (201 lb)... 

Human studies also have reported associations between BPA exposures and female reproductive abnormalities, including effects on the ovary, uterus, and oocyte quality. Studies of BPA effects on ovarian morphology are limited and have focused on polycystic ovarian syndrome (PCOS). One case control study (71 women with PCOS and 100 women without) reported a positive association between serum BPA levels and PCOS (Kandaraki et al. 2011). In three studies of women undergoing in vitro fertilization (IVF), BPA exposure was associated with a decrease in peak serum estradiol levels prior to oocyte retrieval, which may have negative effects on embryo quality (Ehrlich et al. 2012b Mok-Lin et al. 2010 Bloom et al. 2011a). 

Bloom MS, Vom Saal FS, Kim D et al (2011b) Serum unconjugated bisphenol A concentrations in men may influence embryo quality indicators during in vitro fertilization. Environ Toxicol Pharmacol 32(2) 319-323... 

Leroy, J.L., G. Opsomer, S. De Vliegher, T. Vanholder, L. Goossens, A. Geldhof, P.E. Bols, A. de Kruif and A. Van Soom, 2005. Comparison of embryo quality in high-yielding dairy cows, in dairy heifers and in beef cows. Theriogenology 64, 2022-2036. 

On the other hand, the cells which Caspar Friedrich Wolff (1738- 1794) all but discovered in the chick embryo were rejected by determinists as lacking qualities required of monads.1 Following the early Eighteenth century ... 

Embryonic stem cells are derived from pre-implant-stage human embryos, usually at the blastocyst stage (the blastocyst is a thin-walled hollow structure containing a cluster of cells, known as the inner cell mass, from which the embryo arises). These embryos are invariably ones initially generated as part of in vitro fertilization procedures but which are destined to be discarded, either due to poor quality or because they are in excess to requirement. There are an estimated 400 000 in vitro fertilization-produced embryos in frozen storage in the USA alone, of which some 2.8 per cent are likely to be discarded. 

Staging material choice is of the highest importance to produce consistent, quality scans, and several options should be readily available to address the integrity of different specimen types. For example, if a particular specimen is fragile (e.g., E15 mouse embryos), a softer, more flexible material can be used, and conversely, if a particular sample is exceptionally robust (e.g., adult rat femur), a more rigid staging material would be more appropriate. 

In addition when it is necessary to process a large number of specimens per day, taking hours over a single specimen is clearly not a practical approach. The use of MRI to examine fresh, unfixed fetal rat and rabbit heads from embryo-fetal development (EFD) studies has already been proposed (6) (see Note 1) and the compromise between image quality and speed of acquisition that is necessary under these circumstances examined. MRI is now considered to have the potential to be an acceptable alternative to current methods after throughput was increased by scanning multiple specimens in parallel with careful optimization of scan parameters. 

Quality Assurance and Measurement in Diagnostic Radiology Radiation Exposure and Potentially Related Injury Radiation Received in the Decontamination of Nuclear Facilities Guidance on Radiation Received in Space Activities Effects of Radiation on the Embryo-Fetus... 

Vladimirov, V.I. (1974). Dependence of the quality of carp embryos and larvae on female age, amino acid content of eggs and the introduction of amino acid additives to water at early developmental stages (In Russian). In Different Quality of Early Ontogenesis of Fish (V.I. Vladimirov, ed.), pp. 227-254, Naukova Dumka, Kiev. 

We have found that using mature females as embryo donors is a key deviation from standard transgenic mouse production practices. The mature females typically produce fewer oocytes compared to pre-pubescent females, but the oocytes that are released tend to yield more developmentally synchronized populations of zygotes as well as zygotes of similar quality and injectibility. ... 

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