Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of hyaluronidase removal of the cumulus oophorus on the in vitro fertilization rate of oocytes obtained from patients with poor oocyte fertilizability has been evaluated. Eighty-eight oocytes were obtained from 13 patients undergoing in vitro fertilization and embryo transfer (IVF-ET) for indications of male-factor, immunological, and idiopathic infertility. In addition, patients in whom fertilization did not occur on previous IVF cycles were evaluated in the study. The oocytes of each individual patient were randomly assigned into a treatment (removal of the cumulus; N = 40 oocytes) or nontreatment group (control; N = 48 oocytes). Hyaluronidase was used to remove the cumulus immediately following oocyte retrieval, and insemination was performed 6-8 hr later. The overall oocyte fertilization rate (both treated and untreated) was 42%. The treatment group demonstrated a higher rate of fertilization compared to the nontreatment group (55% vs 31%; P less than 0.05). Examination of various patient groups revealed a statistically significant difference in fertilization rates between the treated and the untreated oocytes only in the "no previous fertilization" group (60% vs 28%; P less than 0.05). A higher rate of fertilization of the treated oocytes was also seen in the immunologic infertility group, however, statistical significance was not achieved (50% vs 25%; P = 0.07). Only one clinical pregnancy was achieved in this group of 13 patients. We conclude that in this group of patients, removal of the cumulus prior to insemination may, in some cases, increase the fertilization potential of the oocyte.
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PMID:Hyaluronidase removal of the cumulus oophorus increases in vitro fertilization. 323 Mar 47

Many studies in IVF practice, have tried to assess the maturity and quality of oocytes prior to insemination and relate it to IVF efficiency and to the pattern of ovarian stimulation. They were based on the indirect evaluation of the aspect of the cumulus-corona-cell complex (CCC) which was rapidly shown to be poorly correlated to the oocyte nuclear and cytoplasmic maturity in stimulated cycles. For sperm microinjection procedures, oocytes need to be peeled off from any follicular cell through hyaluronidase action in order to gain an easy access to the zona pellucida and the ooplasm. If therefore becomes possible to precisely known at recovery the nuclear status of the oocyte cohort as well as the rate of degenerative gametes. Immature oocytes can be further matured in vitro. Moreover, the ICSI procedure (intracytoplasmic sperm injection) allows a direct assessment of the cytoplasmic maturation, whatever the maturity of the ZP and its receptors and of the plasma membrane. On a preliminary evaluation of 70 ICSI cycles performed in our collaborative group from september to november 1994 and leading to a 24 % pregnancy rate per oocyte pick-up we focused on the true maturation of the oocyte cohort, its outcome and correlation with ICSI efficiency and stimulation protocol. On the 760 oocytes, 13.9% were atretic, 9% at the germinal vesicle stage (GV), 3.4% in metaphase 1 and 73.7% in metaphase 2 at recovery.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Oocyte maturity and quality: value of intracytoplasmic sperm injection. Fertility of microinjected oocytes after in vitro maturation]. 755 May 60

Intracytoplasmic sperm injection (ICSI) as treatment for male-factor infertility has been introduced worldwide in the past few years in many laboratories using assisted reproduction techniques. Some changes in the existing set-up are necessary before implementing this procedure. The equipment can be divided into two groups: that required for preparation of the microtools and that required for the microinjection procedure itself. A pipette puller, grinder and microforge are necessary for preparation of the microtools. The correct settings and use of these instruments are of crucial importance in preparing a good needle, which in turn is crucial to the injection procedure itself. The microscope has to be equipped with a heated stage, correct optics and manipulators and injectors. The correct settings and use of this equipment also influence the injection procedure and may influence the success rate. Retrospective analysis of the evolution of ICSI in our centre clearly shows a marked improvement following the introduction of some modifications into the procedure. These modifications were (i) reducing the concentration of hyaluronidase used for cumulus and corona radiata removal, (ii) selecting a motile spermatozoon that was immobilized prior to the injection and (iii) aspiration of cytoplasm to ensure rupture of the oocyte membrane. The injection procedure itself can also be influenced by oocyte characteristics. It has been reported that the reaction of the oocyte to the penetration by the pipette has an influence on the success rate. The ICSI procedure has about the same success rate as IVF in cases of non-male infertility. However, work can still be done to improve the success rate of this procedure.
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PMID:Intracytoplasmic sperm injection: laboratory set-up and injection procedure. 966 72

The objective was to compare culture media for in vitro maturation of equine oocytes and for in vitro culture of zygotes produced from IVF of partially zona-removed oocytes. Cumulus-oocyte complexes from slaughterhouse-derived ovaries were washed in m-Dulbecco's PBS and cultured in TCM-199, F10-DMEM or c-F10-DMEM (50% F10-DMEM + 50% F10-DMEM conditioned medium from culture of an equine trophoblast monolayer for 3 or 4 days). All media included FSH, LH, E2, and 10% FCS. After 28 to 30 h maturation, cumulus expansion was scored from 0 (no expansion) to 4 (fully expanded). Oocytes with a 1st polar body were selected for manipulation after removing cumulus cells using hyaluronidase. About one-third of the zona pellucida was cut using a fragment of a razor blade. For fertilization, fresh stallion semen was washed twice in BGM3 (a modified Tyrode's medium) and capacitated with 0.5 mM c-AMP for 3.5 h and 100 microM ionomycin for 15 min and added to oocytes in fert-TALP at 10(6) spermatozoa/mL. After 20 h, some presumptive zygotes were stained, and the rest were cultured in 100% TCM-DMEM conditioned medium. Cumulus expansion in F10-DMEM and c-F10-DMEM was higher (P<0.05) than the TCM-199 control (3.2, 3.5 vs 1.3, on a scale of 0 to 4). However, polar body formation rates were not different among treatments (47, 52 and 50%). The fertilization rates of equine oocytes matured in TCM-199, F10-DMEM and c-F10-DMEM determined by fixing and staining were 41, 35 and 29%, with no significant differences. There were no significant differences among treatments in cleavage rates (36 to 40%), development to morula (3 to 10%), or blastocyst stages (3 to 5%). On Day 14 of culture in c-F10-DMEM treatment, one blastocyst had more than 500 nuclei, but no capsule was formed. In a further study, cleavage rates (46 to 50%) and development to morula (5 to 10%) and blastocyst stages (3 to 8%) were not different (P>0.1) between TCM-DMEM and 100% conditioned TCM-DMEM for culturing embryos. Six embryos (2 morulae and 4 blastocysts) were nonsurgically transferred to 4 recipient mares, but no pregnancy continued.
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PMID:Developmental capacity of equine oocytes matured and cultured in equine trophoblast-conditioned media. 1148 Jun 24

Conventional IVF as well as several assisted microfertilization techniques have shown limited success in the horse. After recent positive results achieved with intracytoplasmic injection of a single spermatozoon (ICSI) in human IVF, we chose to try the method in the horse. We compared conventional IVF to ICSI by fertilization rates of oocytes with compact and expanded cumuli and by developmental potential of the resulting embryos. Cumulus-oocyte complexes (COCs) were obtained by aspirating the follicular fluid from the ovaries of slaughtered mares. Complexes showing complete cumulus investment, either compact or expanded, were randomly assigned to IVF or ICSI trials and separately cultured for IVM. Frozen-thawed stallion spermatozoa were prepared for IVF with a swim-up procedure conducted in Talp-Hepes with heparin or for ICSI in Earle's balanced salt solution (EBSS) supplemented with human serum albumin (HSA). Oocytes for IVF were partially decumulated by pipetting, whereas those for ICSI were totally denuded with 80 UI/ml hyaluronidase. Oocytes were fixed, stained and examined for signs of fertilization the day after IVF or ICSI. The percentage of normally fertilized oocytes showing 2 pronuclei or cleavage was significantly higher with ICSI than IVF (29.8%, 17/57 vs 8.7%, 9/103 ; P < 0.01). Significantly higher fertilization rates were observed in oocytes retrieved with an expanded cumulus when submitted to ICSI procedure as compared with IVF (52.2%, 12/23 vs 17.1%, 6 35 ; P < 0.01), whereas in oocytes recovered with a compact cumulus, fertilization rates were low (14.7%, 5/34 with ICSI and 4.4%, 3 68 with IVF; NS). Embryonal development did not occur after culture following IVF, as indicated by absence of cleavage in any of the 93 inseminated oocytes. Following ICSI, 7 of 55 injected oocytes cleaved, 5 of which had shown expanded cumuli; of the 5, 2 were at the 16-cell stage and one each at the 8-, 3- and 2-cell stage, respectively. The other 2 fertilized oocytes, originating from compact cumuli, reached 4- and 8- cell stages, respectively. These results indicate that ICSI can be applied successfully to in-vitro matured equine oocytes to increase the fertilization rates. In addition, it seems that in vitro cytoplasmic maturation of oocytes issuing from a compact cumulus may not be complete enough to lead to a successful fertilization and that ICSI may be a tool to evaluate ooplasmic maturation.
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PMID:Intracytoplasmic sperm injection (ICSI) versus conventional IVF on abattoir-derived and in vitro-matured equine oocytes. 1672 64

Capacitation is a remarkable process whereby spermatozoa prepare themselves for engagement with the oocyte. Although the existence of this process has been appreciated as a biological phenomenon for more than half a century, its molecular underpinnings still await clarification. We know that some of the major changes involve sterol oxidation and efflux from the plasma membrane, the anterior movement of lipid rafts, changes in the surface expression of a variety of proteins including hyaluronidase and receptors for the zona pellucida, an increase in intracellular cyclic adenosine monophosphate (cAMP), the induction of tyrosine phosphorylation and the expression of hyperactivated motility. These changes are dependent on the presence of bicarbonate, to facilitate cAMP generation, maintain an alkaline intracellular pH and support an optimal level of reactive oxygen species generation and are enhanced by the presence of albumin to provide antioxidant protection to the plasma membrane and promote cholesterol efflux. In vivo, the rate at which sperm cells capacitate is carefully controlled in order to ensure that the release of capacitated spermatozoa from a post-insemination reservoir in the isthmic region of the oviduct is synchronized with ovulation. The factors that control these critical events are now being resolved, aided by proteomic studies that are providing critical definitive information on the range of receptors that exist in the sperm plasma membrane and define the manner in which these exquisitely complex cells interact with their environment. Progress in this area has been enhanced by IVF technology pioneered by Bob Edwards and will ultimately facilitate the design of safe, effective culture conditions for optimization of this revolutionary therapy.
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PMID:Sperm capacitation: a distant landscape glimpsed but unexplored. 2407 44

The presence of cumulus cells (CCs) surrounding ovulated eggs is beneficial to in vitro fertilization and preimplantation development outcomes in several mammalian species. In the mouse, this contribution has a negligible effect on the fertilization rate; however, it is not yet clear whether it has positive effects on preimplantation development. Here, we compared the rates of in vitro fertilization and preimplantation development of ovulated B6C3F1 CC-enclosed vs. CC-free eggs, the latter obtained either after a 5 min treatment in M2 medium containing hyaluronidase or after 5-25 min in M2 medium supplemented with 34.2 mM EDTA (M2-EDTA). We found that, although the maintenance of CCs around ovulated eggs does not increment their developmental rate to blastocyst, the quality of the latter is significantly enhanced. Most importantly, for the first time, we describe a further quantitative and qualitative improvement, on preimplantation development, when CC-enclosed eggs are isolated from the oviducts in M2-EDTA and left in this medium for a total of 5 min prior to sperm insemination. Altogether, our results establish an important advancement in mouse IVF procedures that would be now interesting to test on other mammalian species.
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PMID:A Brief Incubation of Cumulus-Enclosed Mouse Eggs in a Calcium-Free Medium Containing a High Concentration of Calcium-Chelator Markedly Improves Preimplantation Development. 3242 75