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Biomedical subjects

J S Dericks-Tan

Publications and source records attributed to J S Dericks-Tan.

54 records · Page 3Linked to original sources
PubMed1977

The effect of D-ser (TBU)6-LH-RH-EA10 upon gonadotropin release in normally cyclic women.

D-Ser (TBU)6-LH-RH-EA10 (HOE 766) was found to be approximately 40-times as effective as LH-RH in stimulating LH and FSH release in normally cyclic women. The most pronounced reaction was seen in the late follicular phase, the least one in the early follicular phase. Maximal serum gonadotropin levels were found 4 h after the injection of HOE 766. When 5 microgram was injected every 8 h for 3 days, the initially high release of LH and FSH declined progressively to almost nil.

Adult↗
PubMed1976

[The effect of different types of oral contraceptives upon ovarian function (author's transl)].

An investigation on the influence of different types of oral contraceptives upon serum gonadotropins, estradiol and progesterone was carried out in 10 volunteers. The effect of a change from a normophasic type preparation to a sequential preparation (Ovanon and Kombiquens) and from a combined preparation to a minipill (Neogynon and Exlutona) was studied. Two new 3-phase step-up preparations were also tested. Ovulation was inhibited in each case as the preovulatory LH-peak and the subsequent rise of serum progesterone were found to be missing. The basal LH- and FSH-secretion and serum estradiol were demonstrated to be significantly diminished in the volunteers taking combined and sequential preparations. The release of gonadotropines was not inhibited as much when the 3-phase step-up preparations (SHB 261 AB and SHB 264 AB) were used. When Exlutona was taken, the basal LH-secretion was lower than during the pre- and postovulatory phase of the normal cycle, but follicular development did not appear to be inhibited much as both FSH and estradiol were found to be in the normal range.

Adult↗
PubMed1976

[The maternal and fetal levels of human chorionic gonadotropin, human placental lactogen and prolactin during the perinatal period (author's transl)].

The levels of human chorionic gonadotropin (HCG), human placental lactogen (human choriosomatomamotropin HCS) and prolactin (PRL) were determined in the serum of 72 maternity patients and the serum of the newborn infants. The determinations were done with radioimmunologic tests (RIA). These three protein hormones were also determined in the amniotic fluid and in the maternal serum from 4-6 days prior to the delivery of the infant. The concentration of HCG or HCS in the serum of the newborn infants was a mean 0.43 or 0.37% of the level in the maternal serum. The concentration of PRL in the serum of the newborn was 118% and slightly higher than in the serum of the mothers. The concentration in the amniotic fluid was 1.5% for HCG, 5.8% for HCS, and 252% for PRL, compared to the corresponding levels in the maternal serum. The fact that the hormone concentrations in the amniotic fluid are significantly higher than in the serum of the newborn suggests excretion of the hormones from the fetal circulation via the fetal liver and the fetal kidney. The high levels of PRL in the maternal and the newborn serum may be caused by the high concentrations of estrogen or progesterone. Increased during the course of the pregnancy there was a significant sex linked difference in the level of HCG in the maternal serum correlated to the sex of the newborn infant.

Adolescent↗
PubMed1975

[Amenorrhoea after oral contraceptives].

Eleven women with amenorrhoea after taking oral contraceptives were studied. A clomiphene stimulation test was performed in ten, with six also having an LH-RH stimulation test. In most of them there was no reaction or a severely impaired response to both clomiphene and LH-RH, but bleeding episodes could be provoked in most women by continuing clomiphene treatment, and some of these ovulated when HCG was added to the therapeutic scheme. A possible relationship between preexisting psychosomatic disorders and the genesis of postcontraceptive amenorrhoea is discussed.

Adolescent↗
PubMed1975

Increased serum FSH levels correlated with low and high sperm counts in male infertile patients.

Serum FSH, LH and testosterone were measured in 57 (42) normal men and in 80 male infertile patients. In the former, mean (x) FSH was found to be 2.5 ng/ml with a range (x +/- 2 SD) from 0.25 ng/ml to 5.3 ng/ml, mean LH was 2.2 ng/ml with a range from 0.5 ng/ml to 5.6 ng/ml, and mean testosterone was 540 ng/100 ml with a range from 190 mg/ml to 890 ng/100 ml. Immunoassayable FSH was found to be elevated in 17 out of 42 presumably infertile males with sperm counts below 20 million/ml, and in 5 out of 12 men with sperm counts above 120 million/ml. There was no correlation between testosterone and sperm number, motility, and seminal fructose content. The concurrence of depressed spermatogenesis and elevated FSH levels seems to be a relatively good indicator for the presence of organic disorders of the testis.

Adolescent↗
PubMed1975

Kinetic study of the enzymatic inactivation of progestogens by rat liver microsomes.

The kinetics of enzymatic hydrogenation of synthetic progestogens by female rat liver microsomes with NADPH as hydrogen donor were investigated by means of an optical test. Steroids with high progestational activity (Clauberg test) showed a low hydrogenation rate (Vmax). There also seemed to be a certain correlation between molecular structure and Vmax. The metabolites from incubation with the progestogens were isolated from the micro-preparations, and identified by infrared spectroscopy. It was found that the hydrogenation of the olefinic and carbonylic groups involved the uptake of hydrogen from NADPH.

Animals↗
PubMed1975

Measurement of rat LH with a double-antibody solid-phase radioimmunoassay: effect of LH-RH and of testosterone oenanthate in castrated animals.

A double-antibody solid-phase radioimmunoassay for the measurement of rat LH was described. The use of a solid-phase method for the second incubation resulted in a considerable saving of time as compared to the conventional double-antibody method. The sensitivity and accuracy of the method were not affected by this modification. It was found that there was a cross-reaction between the NIAMD-anti-rat-LH-serum-1 used and NIAMD-rat-FSH-RP-1. This indicates that the test system does not specifically measure rat LH but gonadotrophic activity. The RIA was tested under different experimental conditions. In male rats, the effect of castration and of subsequent treatment with testosterone oenanthate upon serum LH, and upon the weight of the seminal vesicles, the ventral prostate, and the levator ani, was examined. Serum LH rose rapidly after castration and reached 2 to 4 weeks after orchidectomy a maximum (8-9 fold increase). Subsequent treatment with testosterone oenanthate caused a rapid decrease of serum LH. The accessory sex organs showed reciprocal changes of weight. In oophorectomized rats whose pituitaries had been blocked with oestradiol monobenzoate and progesterone, a linear log-dose response of plasma LH was found after administration of various doses of synthetic LH-RH.

Animals↗
PubMedDate not supplied

Evaluation of proteohormon concentrations in serum and seminal fluid and its relationship with sperm count.

The measurement of FSH, LH, and PRL in serum and seminal fluid of 105 men attending a male infertility clinic and 21 men of proven fertility (controls) did not reveal an interrelationship between the spermatozoal count and the level of the proteo-hormones in both biological fluid except for FSH, which was significantly higher in the serum of men with low as compared to normal sperm count (p less than 0.01). FSH in seminal fluid was significantly lower (p less than 0.01), and LH-like activity significantly higher (p less than 0.01) than in serum, while there was no difference between the respective levels of PRL. These results could be confirmed in 4 patients with azoospermia due to occlusive disease, and in 1 out of 2 vasectomized men. It was demonstrated for the first time that the higher concentration of "LH" in seminal fluid as compared to serum was due to the presence of HCG-beta or a HCG-like material cross-reacting with the antiserum against LH.

Adult↗
PubMedDate not supplied

[Alpha fetoprotein in maternal serum in pregnancies with trisomy 18].

Maternal serum alpha-fetoprotein (MS-AFP) was assayed before amniocentesis in 2441 pregnancies of women age 35 or over and of women with prior birth of a child with a chromosome anomaly. Ten cases of trisomy 18 and 25 cases of trisomy 21 were detected. In trisomy 18 without neural tube defect we found MS-AFP levels significantly lower than in trisomy 21.

Adult↗