Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To develop artificial materials for prolonged use in the vascular system, the complicated process of surface-induced thrombosis needs to be better understood. Steroidal hormones have a profound role in thrombosis and haemostasis, although adequate studies are not available to demonstrate their part in the thromboembolic phenomena that occur at the blood-foreign material interface. We studied the interfacial phenomena of five steroid hormonal drugs, Sustanon, Menstrogen, Mixogen, Durabolin and Ovral and their interaction with proteins and platelets toward an artificial surface using contact angle, polyacrylamide gel electrophoresis, trace labelling methods, etc. This study demonstrates the effect of these hormones to modulate platelet-surface attachment in the presence of platelet inducers. The addition of steroid hormones to the polymer-protein system can inhibit the level of surface-bound albumin where the fibrinogen binding to an artificial surface has been enhanced or unaltered. Steroids also increase platelet-surface attachment to variable degrees. Prolonged use of steroids or the oestrogen-containing oral contraceptive agents may not be advisable for patients having an artificial implant in contact with blood.
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PMID:Influence of steroid hormones on protein-platelet interaction at the blood-polymer interface. 261 10

Steroids diffuse through polysiloxone at a constant rate, and steroids placed in the vagina rapidly pass through the vaginal epithelium into the circulation. Combining these principles led to the development of contraceptive vaginal rings (CVR) consisting of various progestins, with and without oestrogen, placed in flexible polysiloxone, doughnut-shaped devices. As occurs with oral contraceptives, the CVRs containing progestin plus oestrogen are left in the vagina for 3 weeks and removed for 1 week to allow withdrawal bleeding, while CVRs releasing a small dose of progestins without oestrogen are left in the vagina continuously for several months. Large-scale, clinical trials were performed with a low dose levonorgestrel-releasing-only CVR by the WHO. At 1 year, continuation rates were about 50 per 100 women with 17.2 per 100 discontinuing for menstrual problems and 4.5 for pregnancy. Two sizes of a CVR containing levonorgestrel and oestradiol were studied in a multinational trial organized by the Population Council. At the end of 1 year, about half the women were continuing with the method, one-quarter had discontinued because of bleeding problems, and pregnancy rates were between 1 and 2 per 100 women. The CVR was well accepted by women and their partners, but because of lowered HDL-cholesterol levels and accelerated atherosclerosis in female monkeys, further development of this formulation was discontinued. Recently, phase II clinical trials with CVRs containing combinations of NET-acetate plus ethinyloestradiol and 3-ketodesogestrel plus ethinyloestradiol have been undertaken. These CVRs provide good bleeding control, inhibit ovulation consistently and do not have an adverse effect on serum lipids. Phase III trials with these two types of CVRs will be initiated shortly.
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PMID:Vaginal contraceptive rings. 848 60

Steroids can be administered in at least five different ways: injectables; hormone-releasing intra-uterine devices (IUDs); implants; vaginal rings; and pills. Progestogens which are synthetic steroids, are used as the main bioactive substances. Different progestogens are effective for different periods of time. Progestins in daily oral pills are effective for 24 hours. The effectiveness of a progestogen can be prolonged by incorporating it in a sustained-release system that gradually releases the hormone; therefore they can be effective up to 5 years or more. Two progestogen-only injectables are widely available in the family planning programmes, (DMPA and NET-EN) and two combined injectables, Cyclofem (DMPA + EC), and Mesigyna (NET-EN + EV). The ring is placed by the woman in her vagina, where it gradually releases hormone. Implantable contraceptives are placed just under the skin on the inside of the woman's arm. Implant capsules release the progestogen at a slow, steady rate. There are three implantables available in the market: Implanon; Norplant; and Jadelle. They are effective for 1-5 years, but then must be replaced. Natural and synthetic progestogens were first added to IUDs in the early 1970s. The main problem of long-acting progestogens is the disruption of the menstrual cycle.
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PMID:Long-acting progestogens. 1204 60