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Biomedical subjects

V Odlind

Publications and source records attributed to V Odlind.

86 records · Page 5Linked to original sources

Unaltered lipoprotein and carbohydrate metabolism during treatment with contraceptive subdermal implants containing ST-1435.

Nine healthy, fertile women were treated for six months with subdermal contraceptive implants of two different sizes containing a potent progestogen, ST-1435. Lipoprotein cholesterol and triglyceride concentrations were not influenced by the treatment. Similarly, the main apolipoproteins in low- and high-density lipoproteins were not changed, which further supports the interpretation that the lipoprotein metabolism is not affected by this type of treatment. An oral glucose tolerance test (OGTT) including insulin determinations was performed in five of the volunteers with the largest implants. Blood glucose and insulin concentrations during the OGTT remained unchanged during treatment, indicating that the treatment with ST-1435 did not affect carbohydrate metabolism.

Adult↗

Sexual and contraceptive experience among teenagers in Uppsala.

A questionnaire was offered to 181 sixteen-year-old boys (n = 88) and girls (n = 93) in different schools in the city of Uppsala. The questionnaire was introduced to the students by a nurse midwife during a regular lesson and included over 100 questions dealing partly with sexual education, attitudes towards sex and own experience of sex and contraception. Of the girls, 47% and of the boys, 31% answered that they had had intercourse. Twenty-eight per cent of the girls and 21.5% of the boys had had their first intercourse before the age of 15. Contraception was used at the first intercourse by 59% of the girls and by 70% of the boys. At the very first intercourse, the condom was the most commonly used contraceptive method. Increasing sexual experience changed the contraceptive pattern and at their last intercourse 48% of the girls were on the pill and 33% of the boys said that their girl friend was on the pill.

Adolescent↗

Levonorgestrel plasma levels during continuous administration with different models of subdermal implants.

Plasma concentrations of levonorgestrel were determined in women using subdermal levonorgestrel implants. One group had 6 Silastic capsules (NORPLANT), one group had 4 and one group had 6 covered Silastic rods for variable lengths of time. Levonorgestrel concentrations remained constant around 0.4 ng/ml up until 6 years of use in the Norplant group. The observation period was shorter for the covered rods; plasma concentrations were, however, constant around 0.55 ng/ml and 0.70 ng/ml for 3.5 years with the 4 rods and 6 covered rods, respectively. The difference in mean levonorgestrel concentrations between the three groups were statistically significant (p less than 0.0005). Plasma levels of levonorgestrel were twice to three times higher in blood obtained from the arm with the implants compared to the levels found in the other arm. The application of a tourniquet for variable periods before blood sampling did not influence the plasma concentrations of levonorgestrel.

Blood Specimen Collection↗

Interaction between phenytoin and norethisterone in the rhesus monkey.

The effects of phenytoin treatment on plasma concentrations of norethisterone (NET) was studied in 7 healthy female rhesus monkeys. Before phenytoin treatment was started each monkey received an oral dose of 0.5 mg NET and 2 weeks later the same dose was given intravenously. On both occasions, plasma concentrations of NET were measured at frequent intervals during 24 hours. The monkeys were given phenytoin daily orally for more than 4 weeks. The absorption of phenytoin was confirmed by plasma determinations of phenytoin. While still on phenytoin treatment, the monkeys were again given 0.5 mg NET orally and 2 weeks later i.v. and blood sampling was repeated. During phenytoin treatment, plasma NET concentrations were always below those found before treatment. Both at iv and oral administration, the areas under the plasma concentration vs time curve (AUC) were reduced to 55% of the pretreatment AUCs. No difference in plasma half-life was found during phenytoin treatment. The results of this study may suggest that women on antiepileptic treatment with phenytoin should be given an oral contraceptive with a comparatively high dose of the steroids to provide contraceptive efficacy.

Administration, Oral↗

Plasma protein binding of norethisterone.

Norethisterone (NET) is transported in the blood stream bound to plasma proteins. It is generally believed that only the part of the hormone that is not bound to plasma proteins can exert biological activity. NET binds to albumin and, like other 19-nortestosterone derived progestins, it also binds to sex hormone binding globulin (SHBG). The binding of NET to SHBG was studied in five women during a 21-day treatment cycle with an oral contraceptive containing 3 mg NET-acetate and 50 microgram ethinylestradiol. The total and SHBG-bound concentrations of NET increased in parallel with SHBG during treatment. The fraction not bound to SHBG and the free fraction of NET increased proportionately less, indicating that the total concentrations of NET measured by radioimmunoassay only in part reflect the biologically active fraction of the steroid.

Adult↗

Plasma androgenic activity in women with acne vulgaris and in healthy girls before, during and after puberty.

The possible relationship between plasma androgenic activity and acne vulgaris was investigated. Plasma testosterone and sex hormone binding globulin (SHBG) levels were determined in healthy girls during different stages of puberty, in healthy adult women and in women with acne vulgaris. Testosterone increase during puberty, whereas SHBG decreased during the early stages before it increased and stabilized plasma concentrations of testosterone and SHBG. Women with severe acne vulgaris had testosterone levels in the same range but the SHBG levels were significantly lower than those of healthy women and women with mild acne. These results show a high androgenic activity in the intermediate stages of puberty, when acne vulgaris is a common complaint and an increased androgenic activity in adult women with severe acne vulgaris.

Acne Vulgaris↗

Effects of oestradiol on sex hormone binding globulin.

Sex hormone binding globulin (SHBG) levels were studied for possible effects of oestradiol-17 beta on SHBG. No change in SHBG plasma was recorded during normal menstrual cycles or during treatment with oestradiol-17 beta to menopausal women. However, gonadotrophin treatment to amenorrhoeic women to induce ovulation resulted in high oestradiol concentrations and a pronounced increase in SHBG was found during the luteal phase of these cycles. A marked increase of SHBG was also recorded in a woman with pronounced fluctuations of oestradiol during treatment with levonorgestrel sc implants for contraception. In conclusion, effects on SHBG were only found when extraordinarily high levels of plasma oestradiol were recorded.

Adult↗

Free norethisterone as reflected by saliva concentrations of norethisterone during oral contraceptive use.

Saliva and plasma concentrations of norethisterone (NET) were determined by a radioimmunoassay in 5 healthy women and in one epileptic woman on phenytoin treatment during a 21-day cycle on an oral contraceptive containing 3 mg NET-acetate and 0.05 mg ethinyloestradiol. Plasma non-protein bound concentrations of NET were determined by equilibrium dialysis. Sex hormone binding globulin (SHBG) was measured in all samples. An excellent correlation was found between plasma total, plasma non-protein bound and saliva levels of NET. Plasma non-protein bound and saliva concentrations were in the same range throughout, indicating that saliva concentrations reflect the free fraction of NET in plasma. SHBG increased considerably in all women. A slight decrease in the ratio between total and non-protein bound concentrations was found with time, possibly reflecting a slight increase in protein binding with increasing SHBG. The woman on anticonvulsant therapy had plasma total, plasma unbound and saliva NET concentrations that were only 30 per cent of those of the healthy women. The relationship between the different fractions was similar to that found in the healthy women. The non-protein bound fraction of NET was 4-5 per cent of the total in all women studied.

Adult↗

Effects on sex hormone binding globulin of different oral contraceptives containing norethisterone and lynestrenol.

Six combined oral contraceptive drugs containing ethinyloestradiol or mestranol and norethisterone or lynestrenol were studied throughout six 21-day cycles in healthy female volunteers. There was always one menstrual cycle without treatment between every treatment cycle. Plasma levels of norethisterone were determined throughout treatment by use of a specific radioimmunoassay. Sex hormone binding globulin (SHBG) was measured by an ammonium sulphate precipitation method at the beginning and at the end of each treatment cycle. The results indicated an accumulation of norethisterone in plasma when 1 to 3 mg of norethisterone or lynestrenol was given. There was no obvious accumulation during treatment with 0.5 mg norethisterone. SHBG increased during treatment with all combinations studied. However, this increase was most pronounced with the 50 microgram ethinyloestradiol/l mg lynestrenol, 50 microgram mestranol/l mg norethisterone and 35 microgram ethinyloestradiol/0.5 mg norethisterone combinations. There was no statistically significant increase in SHBG with 50 microgram ethinyloestradiol/2.5 mg lynestrenol or 50 microgram ethinyloestradiol/3 mg norethisterone acetate combinations. The results indicated that the induction of SHBG by the synthetic oestrogens was antagonized by the progestogens in a dose-dependent manner. The effect on SHBG by a combind preparation could be one assessment of the oestrogenicity or androgenicity of the preparation.

Adult↗

Subdermal norethindrone pellets -- a method for contraception?

The mode of action of compressed pellets containing 85 per cent norethindrone (NET) and 15 per cent cholesterol was studied. Four pellets were inserted subcutaneously, in each of five healthy volunteers and left in place for 200--229 days. The NET content of the pellets varied between 23.9 mg and 25.6 mg; and the cholesterol content between 4.2 mg and 4.5 mg. Plasma levels of NET, estradiol and progesterone were determined by radioimmunoassays. Plasma levels of NET varied mostly between 1--2 ng/ml the first month after insertion. After two months plasma levels of NET ranged between 0.5 ng/ml and 1 ng/ml in all volunteers and there was a gradual decrease of the plasma NET levels throughout treatment. Pronounced day-to-day variations in plasma NET levels were recorded. The release rates of NET was calculated to be between 187 micrograms/day and 243 micrograms/day among the five volunteers. Ovulations occurred in four out of five subjects during treatment. This study indicates that the release of gestagen from four NET pellets was only initially high enough to completely inhibit ovulation and that to accomplish full contraceptive efficacy, a higher dose, i.e. more pellets, would have to be inserted.

Adult↗

Plasma levels of norethindrone and effect upon ovarian function during treatment with silastic implants containing norethindrone.

The study was made to evaluate the effect upon the ovarian steroid pattern during treatment with subcutaneously implanted silastic rods containing norethindrone. Four rods, each containing 37 mg norethindrone (NET), were implanted subcutaneously in five women and left in place for 135--200 days. Plasma levels of NET, estradiol and progesterone were determined by radioimmunoassays. After an initial peak found in all subjects, the plasma level of NET declined. Great day-to-day variations of NET were found. Ovulations were suppressed during treatment in three subjects. One subject had regular ovulations throughout treatment and in one subject a single ovulation was recorded. Peaks of estradiol without subsequent ovulation were found in two subjects. The bleeding pattern was irregular; three subjects had varying degrees of spotting and bleeding, two subjects were amenorrheic. The average daily release rate was 300/micrograms, calculated from the amount of steroids lost from the removed rods. This study indicates that the release of steroid from four NET rods is high enough only initially to completely inhibit ovulation.

Adult↗

Plasma levels of norethindrone after single oral dose administration of norethindrone and lynestrenol.

Single oral doses of 0.3 mg, 0.5 mg and 5 mg Norethindrone (NET) and 0.5 mg and 5 mg Lynestrenol (lyn) were given to five women. Lynestrenol is probably metabolized through NET and exerts its main biological activity as NET. Plasma concentrations of NET were determined by a radioimmunoassay at different intervals after administration of the tablets. Peak concentrations of NET were found within two hours after intake of each table. The plasma half life of Net after NET and lyn administration for the period 8-24 h was 8-11 h. No significant difference was found between the half life of NET and the NET tablets and after the lyn tablets. When 5 mg NET was given the plasma half life of NET for the period 24-72 h was around 10 h and this was significantly shorter than the half-life of NET after 5 mg lyn, which was 16 1/2 h. The systemic availability of the drugs was estimated by calculating and comparing the areas under the plasma concentration versus time curve (AUC). 0-24 H. The AUC 0.24 after 0.3 MG NET was almost identical to the AUC 0.24 after 0.5 mg lyn. The AUC 0-24 after 0.5 mg NET was significantly larger than after 0.5 lyn. No difference was found between the AUC 0-24 after 5 mg lyn and 5 mg NET. This study supports the concept of a conversion from lyn to NET. It also shows that there were only minor pharmacokinetic differences between the drugs when all samples were measured as NET.

Administration, Oral↗

Evaluation of a direct fluorescence assay as a screening method in asymptomatic young women.

The purpose of the study was to evaluate one rapid antigen test (DFA), in comparison to culture, for the detection of Chlamydia trachomatis in young, asymptomatic women. C. trachomatis was isolated from specimens of 8.6% of the patients studied, and 11.3% had 10 or more elementary bodies (EBs) in their specimens. A lowered cut-off point of the DFA did not affect the sensitivity of the method, but the predictive value of a positive test decreased markedly when the cut-off point was lowered. Patients with symptoms of genital infection, signs of genital infection, or both had a higher DFA sensitivity than those who were asymptomatic. Patients whose specimens yielded 1-9 EBs were reexamined three times, once every fourth week. We found little evidence that those patients should be regarded as falsely negative in culture, since most of them remained negative. In order to minimize the social consequences of a false positive test, the DFA method should not be substituted for culture as a diagnostic tool, especially for screening of asymptomatic groups with a low prevalence of C. trachomatis.

Adolescent↗