Cervical implant

As under most circumstances progesterone action will hold primacy over estrogenic effects, the cervical mucus, endometrium, and probably the fallopian tubes reflect progestational stimulation. The cervical mucus becomes thick and viscous and thus impervious to spermatozoa. The endometrium is in a state that is not receptive for implantation of a fertilized egg. Probably, the progestational impact on the secretory activity and peristalsis in the fallopian tubes also assists the general contraceptive effect. It is difficult, however, to assess the relative contribution of the various effects to the... 

Although suppression of FSH and LH is the primary mechanism by which combined oral contraceptives prevent ovulation, there are other mechanisms by which these hormones work to prevent pregnancy. Other mechanisms include reduced penetration of the egg by sperm, reduced implantation of fertilized eggs, thickening of cervical mucus to prevent sperm penetration into the upper genital tract, and slowed tubal motility, which may delay transport of sperm.1 Thus, in... 

Combination OCs - Combination OCs inhibit ovulation by suppressing the gonadotropins, FSH, and LH. Additionally, alterations in the genital tract, including cervical mucus (which inhibits sperm penetration) and the endometrium (which reduces the likelihood of implantation), may contribute to contraceptive effectiveness. 

These combined contraceptives seem to function by inducing feedback inhibition of gonadotrophin secretion which, in turn, inhibits the process of ovulation (Chapter 8). They also induce alterations in the endometrial tissue that may prevent implantation. Furthermore, the progestogen promotes thickening of the cervical mucus, which renders it less hospitable to sperm cells. This combination of effects is quite effective in preventing pregnancy. 

The progestogen-only pill, which contains progestogen alone. The pill is taken daily without interruption. It makes the cervical mucus inhospitable to sperm. It may also change the endometrium to discourage implantation, and modify the coordinated contractions of the Fallopian tubes. 

Combined oestrogen-progestogen oral contraceptives have been extensively used since 1956. The principal mechanism is inhibition of ovulation (4, above) through inhibition of gonadotrophin secretion from the h3 othalamus. In addition the endometrium is altered, so that implantation is less likely (7, above) and cervical mucus becomes more viscous and impedes the passage of the spermatozoa (5, above). 

Progestagens used alone inhibit ovulation in up to 40% of cycles, render cervical mucus less easily penetrable by sperm and induce a premature secretory change in the endometrium so that implantation does not occur. There is liable to be break-through bleeding and some are a cause of raised blood pressure and an adverse trend in blood lipids and arterial disease. 

The addition of ketamine to bupivacaine for spinal anesthesia has been studied in 60 patients undergoing spinal anesthesia for insertion of intracavitary brachyther-apy implants for cervical carcinoma (8). They were randomly assigned to receive either bupivacaine 10 mg or bupivacaine 7.5 mg plus ketamine 25 mg. Motor recovery was significantly quicker in the ketamine group. Blood pressure was significantly lower in the bupivacaine group 5 minutes after administration, and perioperative... 

Taking a product from development to successful PMA usually requires at least seven years. The average time to FDA approval once all required testing is completed and submitted for review is 2-5 years [2. Lewin, N. Faster approvals seen for drug and device combination products. BBI Newsletter 2003 26(9).] Given the time and expense involved, a company must try to predict whether their product, nearly a decade in the future, will fill a significant market need and be profitable. Examples of PMA devices approved in the past include an artificial urinary sphincter a penile infiatable implant and electro-optical sensors for in vivo detection of cervical cancer. [3. http //www.fda.gov/cdrh/devadvice/pma/ (accessed October 2005).]... 

On day 61 after surgeiy, the rats were sacrificed by anaesthetizing them with carbon dioxide (C02) gas, followed by cervical dislocation. Immediately after the animal was dead, an incision of about 1 cm at the sample location was made using a scalpel blade and the hydrogel implants were removed with forceps. The... 

Alter cervical mucus, interfere with implantation, and may suppress ovulation. They are indicated in the prevention of pregnancy. 

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