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Biomedical subjects

C Pariente

Publications and source records attributed to C Pariente.

33 records · Page 2Linked to original sources

Can growth hormone increase, after clonidine administration, predict the dose of human menopausal hormone needed for induction of ovulation?

Recent observations claimed that growth hormone (GH) administration increased the sensitivity of the ovary to gonadotropin stimulation. These findings prompted us to assess whether ovarian response to human menopausal gonadotropin (hMG) is correlated to GH reserve. Before hMG administration, 25 patients were tested for GH reserve by administration of clonidine. Of the 25 patients, 8 showed a significant increase in GH (9.2 +/- 4.5 ng/mL) and needed a significantly lower dose of hMG/human chorionic gonadotropin to elicit a good ovarian response than the 17 patients who did not respond to clonidine administration may help to estimate the initial dose range of hMG necessary for induction of ovulation.

Administration, Oral↗

Aromatase activity of human granulosa cells in patients with polycystic ovaries treated with dexamethasone.

The effect of dexamethasone (DEX) (9 alpha-Fluro-16 alpha-methyl prednisolone) on secretion of steroids by human granulosa luteinized cells was studied by culturing cells from mature follicles of women with polycystic ovarian disease and treated for infertility in the in vitro fertilization program. Patients were treated with DEX 0.5 mg/d until the day of human chorionic gonadotropin administration. The cells were cultured for 24 hours in the presence of androstenedione (10(-7)M). After incubating for 24 hours, the medium was replaced and the cells were incubated for an additional 24 hours. The medium was then harvested and assayed for estradiol (E2) and progesterone (P). Results were compared with those of a control group who was not treated with DEX. Estradiol production by cells was significantly lower in the study group treated with DEX. Progesterone production was not influenced by DEX. Follicular fluid levels, E2, and androgens did not vary with DEX treatment, whereas cortisol levels markedly decreased and P levels increased with the treatment. These findings suggest that glucocorticosteroids can directly influence granulosa luteinized cell function.

Androstenedione↗

Hormonal profiles following clomiphene citrate therapy in conception and nonconception cycles.

The hormonal profiles following clomiphene citrate (CC) administration during a single cycle were compared in infertile women who conceived and in those who did not. Of 41 treated patients, ovulation was assumed to have occurred in 28 and was confirmed by clinical pregnancy in five. In the 28 women who presumably ovulated, two distinct patterns of hormonal secretion were observed. A normal response was exhibited by 17 patients (including the five who became pregnant). The other 11 patients exhibited an abnormal response, characterized by significantly higher luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratios than in the normal response group from day 9 until the occurrence of the LH peak (days 9 and 10, P less than 0.05; days 11 and 12, P less than 0.001), and significantly higher oestradiol (E2) levels throughout the cycle (P less than 0.01). In addition, in comparison with the normal response group their LH levels during the follicular phase were significantly higher (P less than 0.05) but their LH peaks at ovulation were significantly lower (P less than 0.02). Moreover, their progesterone levels, in contrast to those in the normal response group, began to increase prior to the LH peak and remained high during the early and mid-luteal phases. None of the women who exhibited this abnormal gonadotrophin response to CC therapy achieved a clinical pregnancy. Exposure to high LH levels in the follicular phase following CC therapy seems to reduce the rate of fertilization and/or to contribute to early embryonic loss.

Clomiphene↗

Steroid secretion by granulosa cells isolated from a woman with 17 alpha-hydroxylase deficiency.

Steroid synthesis in luteal/granulosa cells harvested after follicular aspiration in a patient with 17 alpha-hydroxylase deficiency was investigated. Follicular stimulation with purified FSH after the suppression of ACTH and gonadotropin secretion by corticoid analogs and superactive GnRH agonist permitted ovum pick-up and the study of steroid synthesis in the obtained granulosa cells. Progesterone synthesis was elevated while 17 alpha-hydroxy progesterone, testosterone, androstenedione, and estrogen production was minimal. Aromatase activity was retained in these cells, as demonstrated by the 100-fold increase in estrogen levels after the addition of androgens. Progesterone levels in follicular fluids were in the normal range, while estrogen, 17 alpha-hydroxy progesterone, and androgen levels were minimal. These results provide in vitro evidence of 17 alpha-hydroxylase deficiency in the granulosa cells of this patient.

Adrenal Hyperplasia, Congenital↗

In vitro fertilization and primary embryonic cleavage are possible in 17 alpha-hydroxylase deficiency despite extremely low intrafollicular 17 beta-estradiol.

Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency in genotypic females is characterized by primary amenorrhea and the absence of sexual maturation due to inadequate biosynthesis of ovarian androgens and estrogens. We induced ovarian follicular development in a woman with this syndrome. Ovum pick-up, in vitro fertilization, and primary embryonic development were achieved despite undetectable plasma estradiol and extremely low ovarian androgen concentrations and minute concentrations of these hormones in the ovarian follicular fluid.

Adrenal Hyperplasia, Congenital↗

Ovarian hyperstimulation syndrome: prediction by number and size of preovulatory ovarian follicles.

Monitoring of human menopausal gonadotropin (hMG) treatment for induction of ovulation according to either preovulatory estrogen levels or the presence of a dominant ovarian follicle was found insufficient to prevent ovarian hyperstimulation syndrome (OHS). In 65 infertile patients treated with hMG and human chorionic gonadotropin (hCG), a possible correlation between the number and size of all ovarian follicles on the day of assumed ovulation and the occurrence of OHS was evaluated in order to assess the value of ultrasonography in predicting OHS. It was found that patients with OHS had significantly more follicles at the time of hCG than patients without OHS. Mild OHS was characterized by the presence of eight to nine follicles, 68.7% of which were of intermediate size (9 to 15 mm). In moderate to severe OHS 95% of the preovulatory follicles were less than 16 mm, most of them (54.7%) less than 9 mm in diameter. It can be concluded that a specific preovulatory follicular configuration characterizes mild and severe hyperstimulation. This is important information before hCG administration and emphasizes the value of ovarian ultrasonography in predicting OHS.

Chorionic Gonadotropin↗

Abolishment of the positive feedback mechanism: a criterion for temporary medical hypophysectomy by LH-RH agonist.

The hypothalamic pituitary axis was studied in patients with an abnormal pattern of gonadotropin release during chronic treatment with LH-RH agonist. Two patients had PCOD and the third demonstrated the early luteinization phenomenon. Following a well-defined gonadotropin rise with initiation of LH-RH treatment, no further response was noted. Stabilization of the LH:FSH ratio in PCOD patients was noted after 4 weeks of treatment. Administration of both native LH-RH (100 micrograms) and intravenous pulsatile LH-RH did not evoke any rise in LH. In addition to the above LH-RH challenges, the positive feedback was examined by administration of estradiol benzoate (EB). The study demonstrated that, although the pituitary did not respond to any LH-RH challenge, it may still respond by a rise in LH following EB administration. Both functions of the hypothalamic pituitary axis should be examined in order to determine the state of medical hypophysectomy.

Administration, Intranasal↗

Estrogen receptor binding material in blood of patients after clomiphene citrate administration: determination by a radioreceptor assay.

The aim of the current study was to assess whether clomiphene citrate (CC) and/or active metabolites are present at presumed time of ovulation, nidation, or steroid-sensitive organogenesis, in serum of patients receiving CC for induction of ovulation. A radioreceptor assay, based on competitive replacement of 3H-estradiol on the rat uterus estrogen receptor, by ligands present in serum of patients after CC administration, was developed. Ligands reached maximal concentration 4 to 5 hours after a single dose of CC was administered, and declined with a half-life of 4.5 to 10 hours. In patients receiving CC on day 5 to day 9 in the cycle, ligands are still present on day 14 in the cycle and in some patients on day 22 of the cycle, but no ligands were detected 60 days after CC treatment.

Amenorrhea↗

Thyroid function in attention deficit and hyperactivity disorder.

In view of the recent conflicting findings regarding the causative role of thyroid abnormalities in attention deficit hyperactivity disorder (ADHD), we performed a replication study to clarify the issue and establish clinical guidelines. Thyroid tests were performed in 43 ADHD children and 28 age- and gender-matched controls. Sixteen ADHD children showed total triiodothyronine (TT3) levels which were slightly above the upper limit of normal, but no significant difference in TT3 values was noted between the ADHD and the control groups. Moreover, none of the ADHD subjects had abnormal levels of total thyroxine, free thyroxine, thyroid stimulating hormone or total triiodothyronine reuptake. The present study supplies additional evidence for the lack of an association between thyroid function and ADHD, and counters the suggestion that thyroid function be routinely screened for in ADHD children.

Adolescent↗