Ovulation and

The concept of hormonal control of ovulation first appeared in 1921 when Ludwig Habedandt, a physiologist at the University of Iimsbmck, showed that extracts of the corpus luteum, containing progesterone [57-83-0] C2 H2q02, could inhibit ovulation and make mice and rabbits infertile (10). Subsequent research showed that this phenomenon occurred in other species as well. 

Progestational activity. Effects elicited by progestins, principally a cessation of ovulation and other genital changes related to pregnancy. 

In breast cancer patients, total PR status is measured for hormonal treatment. The presence of PR is associated with increased survival rates and hormonal responsiveness of mammary tumors. PR agonists are widely used in contraception, HRT, breast cancer, and endometrial hyperplasia. Antiprogestins such as RU486 are used for blocking ovulation and preventing implantation, and in addition they are in clinical testing for the induction of labor and to control various neoplastic transformations. 

Judy Cowan, age 28 years, has been prescribed clomiphene to induce ovulation and pregnancy. Judy is very anxious and wants desperately to become pregnant. Her husband, Jim, has come to the clinic with her. Discuss assessments the nurse would consider important before initiating treatment with clomiphene. Discuss information the nurse would include in a teaching plan for Jim and Judy. 

Consider the menstrual cycle, ovulation, and the possibility of pregnancy before beginning treatment. 

The first-line therapeutic options for PMDD include the selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, fluvoxamine, sertraline, paroxetine, and citalopram. These agents can be given either continuously or only during the luteal phase of the menstrual cycle, i.e., initiated at the time of ovulation and discontinued on the first day of menses. 

Efficacy Alleviation of acute bleeding when present ovulation and subsequent pregnancy in women desiring this reduced risk of developing the long-term complications of, for example, PCOS (e.g., diabetes and cardiovascular disease) improved quality of life. 

This material is hazardous through inhalation, skin absorption, penetration through broken skin, ingestion, and produces local skin/eye impacts. It is known to mimic estrogen in the body (hyperestrogenism). In animals, it has caused feminization of male animals and interfered with conception, ovulation, and fetal development in female animals. Specific signs and symptoms of acute high-dose exposure to zearalenone have not been established or have not been published. 

Terranova, P. 1997. Potential roles of tumor necrosis factor-alpha in follicular development, ovulation and the life-span of the corpus luteum. Domestic Animal Endocrinology 14(1), 1-15. 

In females, menotrophins and hCG are used for the treatment of anovulatory infertility. This condition is due to insufficient endogenous gonadotrophin production. Menotrophin is administered to stimulate follicular maturation, with subsequent administration of hCG to promote ovulation and corpus luteum formation. Mating at this point should lead to fertilization. 

Donath J, Nishino Y (1998) Effect of partial versus pure antiestrogens on ovulation and the pituitary-ovarian axis in the rat. J Steroid Biochem Mol Biol 66 247-254... 

Another problem is the direction of pollen tube growth, which should be considered as tropism, related to attraction by the fertile ovules. Many observations of pollen tubes in the fluorescence microscope supported this suggestion—pollen tubes pass by the sterile ovules and grow in the direction of the fertile ones. The number of ovules penetrated by a pollen tube is correlated with the number of developing seeds, which supports the hypothesis about interaction (attraction) between the ovule and pollen tube (1,2,5). 

Intermediate-duration studies with treated females show that exposure to chlordecone may result in persistent vaginal estrus, decreased ovulation, and reproductive failure. Persistent vaginal estrus was observed in female mice at doses as low as 2 mg/kg/day for 3-6 weeks (Huber 1965 Swartz and Mall 1989 Swartz et al. 1988). Increased atresia of follicles (Swartz and Mall 1989), decreased ovulation (Swartz et al. 1988), and small and medium-sized follicles (Swartz and Mall 1989) have been observed after 4 weeks of exposure to 8 mg/kg/day of chlordecone. Similarly, decreased corpora lutea have been observed following administration of 3.9 mg/kg/day for 130 days (Huber 1965). Decreased numbers of litters or complete reproductive failure have been observed after exposure of female rats to 1.62-1.71 mg/kg/day for 4.5 months or female mice to 5.2 mg/kg/day for 160 days (Huber 1965). 

Sillen-Tullberg, B. and Mailer, A. P. (1993). The relationship between concealed ovulation and mating systems in anthropoid primates a phylogenetic analysis. American Naturalist 141, 1-25. 

Humans are the only species that do not show any visually observable physical sign of ovulation, and human female sexual cripsis is thought to be complete. In this preliminary approach we tried to find out if female body movements change qualitatively during cycle. In order to accomplish this 150 video clips (duration four seconds each) of a female... 

Figure 19.6 A 28-day menstrual cycle. The approximate number of days for menstruation, ovulation and the follicular and luteal phases are shown.

An anti-progesterone (mifepristone, RU 486) pill is used to inhibit ovulation and implantation. 

The olfactory system of the male is extremely sensitive to 17,20jSP. The fish respond to a concentration of 5 x 10 ° mol/1. This amount(3 x 10 molecules) is released by a 90 mm female fish into 1 liter water. The females are also very sensitive to 17,20/3P. It may stimulate ovulation. Of 47 vitellogenic females 13 ovulated when 17,20/3P was added to the water, while only 1 of 43 did so in untreated water (Dulka etal, 1987). Both sexes probably release 17,20/3P. Ecologically, this bisexual pheromone is thought to synchronize milt production with ovulation and thus coordinate spawning in local populations (Dulka etal, 1987 Sorensen and Stacey, 1990). 

Under certain conditions, ovulation and plasma gonadotropin levels can be stimulated by ovarian fluid from other ovulated females. The African catfish, Clariasgaricpinus, is an example. It lives in muddy water and spawns at night, conditions expected to favor pheromone commimication. Moreover, this species is a seasonal breeder, spawning after rainfall. The sudden mass spawning requires synchronization. Water from males or ovulated females, and also ovarian fluid of ovulated females, experimentally induced ovulation in 67% of females. Plasma gonadotropin was also increased by these treatments (Resink etal., 1989c). 

In grouped female mice ovulation and estrus are suppressed (Champlin, 1971) and pseudopregnancies occur (van der Lee and Boot, 1955). The odor of crowded female mice (eight per cage) inhibited ovulation in other females. The hormonal control of this effect has been difficult to explain. Early studies indicated that ovariectomized mice were not able to inhibit other females but in other studies, ovariectomized females still inhibited estrus in other females (Marchlewska-Koj, 1990). 

Estradiol subsequently builds up in the blood and first (within 2 to 12 hours) reduces the levels of follicle-stimulating hormone (FSH) and the amplitude of LH pulses, then (within 12 to 48 hours) causes preovulatory surges of LH and FSH. The former promotes ovulation and development of a corpus luteum (reviewed in Martin et ah, 1986). Two compounds have been indicated in the effect of the odor of ram s fleece on LH secretion in anestrous ewes. These are 1,2-hexadecanediol and 1,2-octadecanediol. In Merino sheep at least, maximum stimulation of ovulation requires full exposure to a ram, such as fenceline contact in pastures. Olfactory cues from the ram s wool, presented in a facemask for the ewe, are ineffective by themselves visual and tactile stimuli are also important. The Merino breed does not rely as much on olfactory cues as other breeds of sheep (Pearce and Oldham, 1988). The effect is not necessarily species specific hair extract from male goats stimulates LH release in ewes. For this effect, the accessory olfactory system is not necessary (Signoret etah, 1989). 

Females are dosed 14 days before mating (N.B. there are 5 days between ovulations) and through to lactation. 

In mice and male rats, the oral LD50 was approximately 4g/kg symptoms of toxicity were ataxia and hyperactivity followed by inactivity, loss of muscular tone, labored breathing, clonic convulsions, and death within 2-7 days. Daily administration of 132mg/kg body weight in the diet for 13 weeks decreased the fertility of CD rats 14 days at 96mg/kg altered the estrous cycle of females." In female rats 50 mg/kg injected intraperitoneally on the day of proestrus delayed ovulation and resulted in a lower fertility rate, a reduction of live fetuses, an increase in resorptions, and a slower rate of fetal development. Gavage doses in rats of... 

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