In vitro fertilization procedures

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. 

Recommended dosage and monitoring requirements Once-daily subcutaneous doses of Antagon 250 pg have been effective for prevention of premature LH surges during ovarian stimulation in in vitro fertilization procedures. 

Loumaye EEuropean Recombinant LH Study Group. Human recombinant luteinizing hormone is as effective as, but safer than, urinary human chorionic gonadotropin in inducing final follicular maturation and ovulation in in vitro fertilization procedures results of a multicenter double-blind study. J Clin Endocrinol Metab 2001 86(6) 2607-18. 

Gonadotrophins are also used in assisted reproduction procedures. Here the aim is to administer therapeutic doses of FSH that exceed individual follicular FSH threshold requirements, thus stimulating multiple follicular growth. This, in turn, facilitates harvest of multiple eggs, which are then available for in vitro fertilization. This technique is often employed when a woman has a blocked fallopian tube or some other impediment to normal fertilization of the egg by a sperm cell. After treatment, the resultant eggs are collected, incubated in vitro with her partner s sperm, incubated in culture media until the embryonic blastocyst is formed, and then implanted into the mother s uterus. 

G. Other applications Limited data show some beneficial effects of leuprolide in the treatment of breast cancer. According to Micromedex, there is good documentation that leuprolide is effective for bowel pain and nausea associated with irritable bowel syndrome. Leuprolide has been used for controlled ovarian hyperstimulation to enhance the in vitro fertilization-embryo transfer procedure. In endometriosis, the goal of treatment is pain relief and reduction of endometriotic lesions. In children with central precocious puberty, stimulated and basal gonadotropins are reduced to prepubertal levels. Testosterone and estradiol are reduced to prepubertal levels in males and females, respectively. 

Assisted reproductive techniques involve procedures that deliver a concentrated sperm sample directly to the uterus (artificial insemination), or procedures that acquire fertile ova using laparoscopic or ultrasonographic techniques and assisting fertilization in the laboratory (in vitro fertilization) or in the fallopian tubes using either gamete intrafaUopian transfer or zygote intrafaUopian transfer. In vitro fertiliza-... 

The infant girl that showed up the following July was named Louise Joy Brown. The procedure that produced her, in vitro fertilization (IVF), has since produced millions of new people around the world. Louise herself is now in her thirties, a smiling, happily married woman with a child of her own (conceived in the ordinary way). 

In view of the notion that chemotaxis is required for the selection of capacitated spermatozoa, faulty precontact sperm-egg communication may be one of the causes of male infertility, female infertility, or both. It is reasonable that, in the future, chemotaxis may be exploited as a diagnostic tool for sperm quality and male infertility and may be used as a biological sperm-selection procedure before in vitro fertilization, especially before intracytoplasmic single sperm insertion or for intrauterine insemination. Moreover, the chemotactic activity of a follicular fluid may be an effective way to monitor the possible effects of different ovulation induction protocols on the maturational status of oocytes aspirated for in vitro fertilization [2]. On the other hand, interference vwth sperm chemotaxis may represent an exciting new approach to contraception. 

In Vitro Fertilization. In vitro fertilization (IVF) is one of the most common applications of assisted reproduction technology. The Latin term in vitro literally means in glass. In vitro fertilization is a medical procedure in which egg cells are fertilized not inside the body (in vivo) but within an artihcial laboratory environment. Because this procedure is both complex and expensive, it is often employed to help couples for whom other infertility treatments have already failed. 

Zygote intrafallopian transfer (ZIFT) is a procedure that combines elements of both in vitro fertilization and GIFT. First, gametes are extracted and fertilized under controlled laboratory conditions. Next, they are inserted into the Fallopian tubes using the same method as in GIFT. Because GIFT and ZIFT... 

As previously mentioned, neither the incorporation of radioactive amino acids into embryo proteins nor the presence of amino acids in the immediate environment of the embryo necessarily indicate that free amino acids contribute significantly to the nutritional needs of the embryo. Nevertheless, it should be noted that Mintz (1964), employing autoradiography, observed in the cultured mouse embryo an increase in amino acid incorporation from fertilization to the blastocyst stage. This observation was essentially confirmed (Brinster, 1971) for the mouse when quantitative procedures for the analysis of radioactivity were used. During cleavage of the rabbit embryo in vitro (Manes and Daniel, 1969),... 

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