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Biomedical subjects

J Hammerstein

Publications and source records attributed to J Hammerstein.

At least 19 recordsLinked to original sources
PubMed1994

Reproductive medicine--a field of contradictory legislation in Germany.

A brief survey is given on the German legislation concerning reproductive medicine which is contradictory both in juridical and ethical terms. Being under strong ideologic and/or populistic pressure, it favours negative family planning measures such as all kinds of birth control including induced abortion, and handicaps, on the other hand, the more sophisticated procedures of assisted fertilization to overcome infertility. Thus, legal restrictions in this country halt the scientific progress and set back the clinical standard in comparison to our neighbouring countries, all of which are more liberal in their respective legislation.

Ethics, Medical↗
PubMed1993

Pharmacokinetics and protein binding of 3-ketodesogestrel and gestodene in the serum of women during 6 cycles of treatment with two low dose oral contraceptives.

The serum concentrations of 3-ketodesogestrel (KDG) and gestodene have been measured in 30 and 31 women respectively who took low dose oral contraceptives containing 30 micrograms ethinylestradiol together with either 150 micrograms desogestrel or 75 micrograms gestodene for 6 months. On days 1, 10 and 21 of the first third and sixth treatment cycles blood samples were drawn at 0, 0.5, 1, 1.5, 2, 3, 4 and 24 h. KDG and gestodene levels were measured by radioimmunoassays and were evaluated for Cmax (peak serum concentration), tmax (time to Cmax), and AUC (area under the curve) to 4 and 24 h. The overall total gestodene concentrations were higher and the accumulation of the steroid throughout a cycle greater than that of KDG. For example, the AUC0-4 of gestodene increased in cycle 1 by a factor of 2.8 (day 10 vs. day 1) and 3.6 (day 21 vs. day 1) compared to 2.3 and 2.6 for KDG. The higher concentration of gestodene reflects a lower volume of distribution than KDG, and is consistent with gestodene binding to sex hormone binding globulin (SHBG) with a higher affinity than KDG. Concentrations of KDG and gestodene were higher on day 1 of cycles 3 and 6 than on day 1 of cycle 1. The serum concentrations of KDG and gestodene during multiple dosing cannot be predicted on the basis of single dose pharmacokinetics.

Adolescent↗
PubMed1993

Sexual behavior, contraception and the risk of contracting HIV.

Recently, concern has been expressed on a possible association between the use of oral contraceptive pills (OCs) and an increased risk of contracting the HIV infection. As a consequence it has been postulated that a low prevalence of condom use due to widespread utilization of oral contraceptive pills would result in an acceleration of the spread of AIDS. The International Committee for Research in Reproduction (ICRR) a group of eleven experts in the field of gynecology, endocrinology and contraception, wishes to comment on the concerns raised about OC use and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Effects of ethinyl estradiol on semen quality and various hormonal parameters in a eugonadal male.

OBJECTIVE: To determine the influence of estrogens on male fertility. DESIGN: A 36-year-old eugonadal male was subjected to two different regimens of treatment with ethinyl estradiol (EE2). Sperm quality, immunoreactive luteinizing hormone (LH) and follicle-stimulating Hormone (FSH), testosterone (T), estrone (E1), estradiol (E2), dehydroepiandrosterone sulfate (DHEAS), prolactin (PRL) and sex hormone-binding globulin were determined at intervals of 2 weeks for 315 days. SETTING: A gender dysphoria clinic. PATIENT: A transsexual male nurse. MAIN OUTCOME MEASURES: It was hypothesized (and confirmed) that by comparing the effects of increasing and constant dose of EE2 on fertility parameters, differences in estrogen-sensitivity would show more clearly. Furthermore, this procedure served to find the minimal dose of EE2 for complete testicular suppression. RESULTS: Low doses of EE2 (20 micrograms/d) had no negative effect on sperm motility and density for a period of approximately 4 weeks, whereas high doses (60 micrograms/d) reduced motility already after a few days and led to a pronounced decrease in sperm density after 2 weeks. After discontinuation of therapy, motility normalized faster than sperm density. Under increasing doses of EE2 there was a constant decrease of FSH that occurred several weeks earlier than that of LH. Under constant dose of EE2 (60 micrograms/d) the decrease of LH was delayed (with respect to FSH) by only a few days. The decrease in T showed a stronger correlation with that of FSH than with that of LH. Volume and fructose content of the seminal fluid correlated with the decrease in T. Rebound effects were observed for FSH, LH, T, and fructose during the therapy-free interval. Ethinyl estradiol therapy had no influence on the serum concentrations of E1, E2, and PRL. Estrone was the dominant estrogen before and after therapy with EE2. Adrenal gland activity was markedly suppressed by EE2, as reflected by the decrease in DHEAS. CONCLUSION: The suppressive effect of EE2 on FSH and sperm motility was more pronounced and consistent than on LH and sperm density. The T decrease appears to be mainly caused by a direct effect of EE2 on the testes.

Adult↗
PubMed1991

[The demonstration of the patency of the uterine tubes with color-coded duplex sonography in combination with ultrasonic contrast media].

Tubal patency was studied in 17 sterile women by means of colour-coded duplex sonography (CCDS) with local injection of an ultrasonic contrast medium. The results were compared with a conventional hysterosalpingogram. CCDS demonstrated all the soft tissues and their mobility. The ultrasonic contrast medium was SH U 454 (Schering). The colour signals generated by the air bubbles makes it possible to demonstrate tubal patency on both sides. The combination of an ultrasonic contrast medium and CCDS provides a simple, rapid, accurate and safe method for demonstrating tubal patency. Tubal patency can be demonstrated in the presence of anatomical complications and requires only a small amount of contrast medium.

Adult↗
PubMed1991

Increased concentrations of eicosanoids and platelet-activating factor in menstrual blood from women with primary dysmenorrhea.

Prostanoids, leukotrienes and platelet-activating factor were measured by radioimmunoassay in menstrual blood of seven women with primary dysmenorrhea and five healthy controls. The eicosanoids and PAF concentrations in dysmenorrheic patients were significantly higher than those found in healthy women (P less than 0.005 for PGF2 alpha, 11-dehydro-TXB2, 2,3-dinor-TXB2 and LTC4/D4; P less than 0.001 for PAE; P less than 0.05 for PGE2 and 2,3-dinor-6-keto-PGF1 alpha). Whereas no relationship could be found between the concentrations of PGF2 alpha, PGE2, 11-dehydro- and 2,3-dinor-TXB2 and severity of primary dysmenorrhea, a close correlation between LTC4/D4 and PAF and severity of the disease was observed, particularly in patients who responded poorly to therapy with prostaglandin synthetase inhibitors. We conclude that the hyperstimulation of myometrial activity is not caused by selective stimulation of one metabolic pathway of arachidonic acid, but rather by an overall stimulation of phospholipid metabolism. The assessment of prostanoids, leukotrienes and PAF in menstrual blood many be useful as a direct index of primary dysmenorrhea, and the development of their antagonists may have therapeutic implications in improved treatment of the disease.

Adult↗
PubMed1990

Prodrugs: advantage or disadvantage?

Our knowledge of the peculiarities of prohormones is rather limited, both pharmacologically and clinically. Generalizations cannot be made except that the lapse of time until peak blood values of the active drug have been reached are always greater after intake of the prodrug than after intake of the drug. This finding is presumably of no clinical importance. If pharmacokinetic differences are limited to the phase of distribution, bioequivalence may be assumed. If, on the other hand, the area under the curve during the elimination phase is smaller for the prodrug than for the drug, the potency of the former should be decreased. A shift in the spectrum of endocrine actions as a result of the biotransformation of the prodrug into the active drug is rather the exception than the rule, and so is a change in side effects. If there are major differences in this respect, metabolic pathways in addition to those leading to the respective active drug must also be taken into consideration.

Biotransformation↗
PubMed1987

[Oral contraceptives: clinical pharmacology, composition, choice of preparation].

Following introductory terminological clarifications, the pharmacological peculiarities of the synthetic estrogens and progestogens used in oral contraception are outlined. With the low-dose formulations containing less than 50 micrograms estrogen per pill ("micropill") coming in preferential use, the definite differences between the profiles of effects of the three major progestational categories--estranes, gonanes and pregnanes--lost much of their impact on clinical tolerance. Within the three classes of progestogens, the profiles of effects of the various compounds are, anyhow, very similar with major deviations occurring only exceptionally. As to the contraceptive estrogens, ethinyl estradiol differs from mestranol, if any, in quantitative but not in qualitative respect, the latter substance not being commonly used in Europe any longer. Besides potencies and profiles of effects of the individual contraceptive steroids, the quantitative estrogen/progestogen relationship of a "pill" is another variable of great importance for the development of unwanted side effects in the field of lipid and carbohydrate metabolism as well as of blood coagulation. Due to the lack of influence on lipid metabolism, progestogens of the pregnane series, being driven into an outsider position since long, deserve increasing attention again. As a general principle, women of all age groups should at least try to use the "micropill"--either combination-type or tristep formulations--in order to minimize risks. Only a few indications are left for the primary prescription of high-dose combination-type, sequential and step-up preparations as well as for the progestogen-only "minipill". With "micropill" becoming the oral contraceptives of the first choice, also rational reasons for changing formulations have become rare.(ABSTRACT TRUNCATED AT 250 WORDS)

Contraceptives, Oral, Hormonal↗