Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027497 (nausea)
 23,468 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The contraceptive effect of Depo-Provera or medroxyprogesterone acetate, a long-acting injectable progestogen, has been mainly attributed to its ability to prevent ovulation through its action on the hypothalamic pituitary axis, reducing the levels of plasma gonadotropin, progesterone, and estradiol, and suppressing the midcycle surge of luteinizing hormone. Its other contraceptive effects are thickening of the cervical mucus, causing a barrier to spermatozoa, alteration in tubal ovum transport, and atrophy of the endometrium. A standard dose of 150 mg injected every 3 months is as effective as the combined oral pill and more effective than the progestogen-only pill or IUD. Contraindications to use are thrombophlebitis, liver dysfunctions, suspected breast or genital malignancy, and abnormal uterine bleeding. Reported discontinuation rates range from 7-80%. The World Health Organization (1977) reported a gross cumulative discontinuation rate of 23.4/100 women years in 8 centers. Depo-Provera has a long list of short-term (menstrual disorders, fluid retention, nausea, hair loss, and others) and long-term (delayed fertility return, congenital abnormalities, cancer others) disorders. Its advantages include: 1) convenience, 2) effectiveness, 3) no risk of infection or other side effects of the coil, 4) none of proven side effects or long-term hazards of estrogen, and 5) no inhibition of lactation. The safety of Depo-Provera has been a controversial issue which led to its banning in the U.S. Its carcinogenic potential has been reported in clinical trials with animals. Its greatest disadvantage is that it takes control of a woman's fertility firmly out of her hands into those of the doctor. Depo-Provera should not be used except as an absolute last resort. It should not be used as a long-term contraceptive in this country, and research monies should instead be channeled into the development of a safe, reliable contraceptive with no systemic side effects.
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PMID:Depo-Provera: an injectable contraceptive. 645 20

Gossypol is a phenolic compound isolated from the seeds, stems, and roots of the cotton plant. The chemical has been known for years as the toxic principle left in the cottonseed cake after cottonseed oil extraction. It is also present in the cold pressed cottonseed oil from which it may be removed through reactions with alkali. Extremely low birthrates in China's Hebeth province were traced to the use of crude cotton seed oil for cooking purposes. After prolonged investigation, it was determined that male infertility was related to the gossypol content of the oil. After a short period of animal studies, the Chinese in 1972 undertook widespread clinical trials of gossypol as a contraceptive agent. Over 4000 men have undergone treatment with the drug, some for as long as 4 years. Infertility resulted after 2 months of a daily dose of 20 mg and then the participants were maintained on 150-220 mg/month in divided doses. The drug apparently did not decrease libido in most test subjects and had not been reported to impair potency. Semen analysis at various intervals showed a decrease in motile sperm, malformed spermatozoa, and then a decrease in sperm count, leading to azoospermia. On discontinuation of the substance, the antifertility effect completely reversed itself within 3 months. No obvious toxic effects of pathological changes were observed in human and animal studies. Levels of luteinizing hormone and testosterone were unchanged and apparently indicated that gossypol does not affect hormonal balances. Adverse reactions reported to date include transient and reversible weakness in 10% of the test subjects on initiation of therapy. In addition, appetite changes, gastric discomfort, and nausea have been noted. A few cases of slight EKG changes and disturbances in potassium metabolism have occurred. No chromosomal changes have been observed nor have tests shown any mutagenic effects of the drug. In conclusion, preliminary data indicated that gossypol may offer an excellent new approach to contraception. Further testing is required to elucidate the drug's mechanism of action and to determine its adverse and possible toxic effects.
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PMID:Gossypol as an oral contraceptive for men. 692 15

CELL INJURIES DURING FREEZING AND THAWING: The aim of various cryopreservation procedures is to minimize cell injuries during the freeze-thaw cycle (cryoinjuries). Generally, the cell damage during freezing and thawing procedures may be the results of: (a) extensive cellular dehydration (solution effect) and/or (b) intracellular ice crystallization/recrystallization (mechanical cell damage). Two independent mechanisms are involved. They can act simultaneously, leading to cytolysis. The first one is expressed primarily during low rate freezing, and the second one during rapid freezing. Thus, determination and use of the optimal cooling velocity, specific for each type of isolated cells, should be considered. Finally, a higher degree of cell destruction has been documented when the transition period from liquid to solid phase (release of the fusion heat) is prolonged. CRYOPROTECTIVE AGENTS: For successful cell cryopreservation, cryoprotectants are needed. They decrease the osmotic gradient and the vapor pressure difference between the intra- and extracellular area. Adequate choice of the most suitable type and concentration of cryoprotective agent is important for the required cell recovery after thawing. There are several well known protocols for obtaining cryopreservation of isolated cells using different cryoprotectants. Glycerol, dimethyl sulfoxide (DMSO) and propanediol sucrose are commonly used as cryoprotectants, though in different concentrations. Glycerol, a trihydric alcohol, is a clear, colorless fluid. Pharmacologically, it is relatively inert. DMSO is a colorless liquid with a sulphur-like smell and has several medical uses. It is highly polar and dissolves many water- and lipid-soluble substances. DMSO given intravenously may cause nausea, vomiting, local vasospasm and an objectionable garlic-like odor and taste. HUMAN SPERM, OVA AND EMBRYOS CRYOPRESERVATION: Despite the fact that cryopreservation procedures of spermatozoa, ova and embryos are already in routine clinical use, some questions related to the optimal cooling velocity during controlled-rate freezing and the choice of the most effective, either penetrating (glycerol, dimethyl sulfoxide) and/or non-penetrating (hydroxyethyl starch) cryoprotective agent at the appropriate concentration are not resolved.
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PMID:[Current knowledge on cryopreservation of spermatozoa, ovum cells and zygotes]. 953 71

This review discusses clinical aspects and mechanism of action of various injectable steroids used for contraception. The clinical effectiveness of various injectables is presented tabularly, with the following compounds having notable failure rates: medroxyprogesterone, 400 mg, 9.5 pregnancy/100 woman years; SH 582, 200 mg, 37/100 woman years; SH 582, 2.5 mg, 30/100 woman years; oxagesterone, 50 mg, 22/100 woman years. Contraceptive efficacy of medroxyprogesterone acetate, norethindrone enanthate, and Deladroxate was confirmed. Cycle control using injectables was generally good, but oral estrogens can be used with the injectables to help cycle control if needed. Clinical side effects to pure progestogens are minimal, although headaches, dizziness, dyspepsia, or nonspecific effects have been noted. Addition of estrogen leads to breast symptoms in 9-13% of cases, and sometimes to weight gain, nausea, and vomiting. Use of injectables is particularly encouraged for postpartum women. Despite cycle irregularities associated with progestogen injectables, acceptability is good--drop-out rate is in the 25% range for the commonly used compounds. Fertility is reestablished within 5 weeks to 4 months after injections cease. Possible mechanisms of action of injectables include: inhibition of ovulation either due to inhibition of luteinizing hormone or direct effect on the ovary; effect on the endometrium; or effect on cervical mucus such that it becomes hostile to spermatozoa.
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PMID:Injectable steroids as a method of contraception. 1231 80