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Biomedical subjects

H Doorenbos

Publications and source records attributed to H Doorenbos.

At least 55 records · Page 3Linked to original sources
PubMed1984

Adrenal suppression by oral high-dose medroxyprogesterone acetate in breast cancer patients.

The effects of oral MPA, 300 mg t.i.d., on adrenal function in postmenopausal patients with disseminated breast cancer were evaluated. The levels of serum cortisol, ACTH, androstenedione, DHEA-S, LH, FSH, GH, and prolactin in 22 patients receiving MPA were compared with those in another group of 28 postmenopausal patients in whom levels were measured before treatment. The median morning cortisol level was 70, 10-465 nmol/l (controls 395, range 155-785 nmol/l), median androstenedione 1.09, range 0.55-3.10 nmol/l (controls 3.75, range 1.23-9.81 nmol/l), and median DHEA-S 555, range 55-1,300 nmol/l (controls 2,440, range 1,015-6,340 nmol/l). No appreciable change in ACTH levels was found. Gonadotropins were also markedly suppressed. The median LH level was 4.3 (range 0.8-18) U/l, as against 83 (range 19-116) U/l in controls. The median FSH level was 7.2 (range 0.5-27) U/l, as against 71 (range 12-262) U/l in controls. Prolactin and GH levels remained largely unchanged. The suppression of androstenedione synthesis, the main precursor of postmenopausal estrogens, may represent the major therapeutic effect of high-dose MPA in postmenopausal patients with breast cancer.

Adrenocorticotropic Hormone↗
PubMed1984

No change in plasma free testosterone ratio and plasma sex hormone-binding globulin concentration during hCG stimulation.

Plasma sex hormone-binding globulin (SHBG) levels and free testosterone ratios were determined independently after administration of hCG for 4 consecutive days to eight normal men. Correcting for nonspecific dihydrotestosterone binding, no changes in plasma SHBG were found. The free testosterone ratio, measured by equilibrium dialysis, did not change despite doubling of total plasma testosterone. The increase in plasma testosterone after hCG stimulation was due to increased production only, with equivalent changes in free testosterone concentration, and was not a result of changes in SHBG concentration.

Chorionic Gonadotropin↗
PubMed1983

Leydig cell function in patients with testicular cancer during and after chemotherapy.

In two groups of patients with disseminated testicular carcinoma the effect of combination chemotherapy on the pituitary-gonadal axis was evaluated, after unilateral orchiectomy: The two groups comprised 15 patients without hCG-producing metastases (group A), and 14 patients with hCG-producing metastases (group B). Seven patients who had received no chemotherapy were studied one year after unilateral orchiectomy as a control group (group C). In group A, serum levels of testosterone and oestradiol increased during chemotherapy, as did the levels of LH and FSH. The serum LH and FSH response to LHRH was increased following chemotherapy, whereas the serum testosterone increase after hCG stimulation remained unchanged. A rise of 316% in SHBG binding capacity was found after chemotherapy. This presumably accounted for the elevated steroid levels in the presence of high gonadotrophin levels, but unaltered Leydig cell response. The elevated serum levels of testosterone and oestradiol and the suppressed serum FSH levels normalized during disappearance of ectopic hCG production in group B patients. Leydig cell refractoriness to hCG and the FSH response to LHRH also reverted to normal. After chemotherapy, FSH, but not LH levels exceeded those of group C patients, presumably as a result of the azoospermia induced by chemotherapy. The hormonal changes associated with chemotherapy are best explained by an increase in serum binding proteins, notably SHBG.

Adolescent↗
PubMed1983

Altered Leydig cell function in patients with testicular cancer: evidence for bilateral testicular defect.

In search of an abnormality in Leydig cell function in patients with testicular cancer, serum levels of testosterone, oestradiol, LH and FSH were compared in 3 groups of men. Group I comprised 26 patients studied after recent orchidectomy for a testicular carcinoma, group II 8 patients operated for benign testicular lesions and group III 8 normal controls. In group II normal testosterone values were found as a result of increased LH release. In group I patients, however, testosterone levels often were low, despite elevated LH levels and increased LH capacity. Evidently, in these patients a partial Leydig cell insufficiency may be present, which does not recover within one year of orchidectomy. After removal of one testis for benign disease, normal testosterone levels are maintained by increased LH levels. After orchidectomy for testicular carcinoma a partial Leydig cell insufficiency may be revealed, which seems to have a permanent character. A pre-existent Leydig cell insufficiency of the remaining testis in patients with testicular cancer indicates a bilateral testicular defect.

Adolescent↗
PubMed1982

Scintigraphy with 201Tl for detection of thyroid cancer metastases.

In four patients with disseminated papillary or follicular thyroid carcinoma metastatic sites could be demonstrated by scintigraphy with 201Tl. Uptake was present during TSH suppression with thyroid hormone administration. In three of the four cases 201Tl scanning revealed metastases while 131I uptake after triiodothyronine withdrawal was absent. In one patient 201Tl demonstrated some metastatic sites while both 131I uptake and thyroglobulin levels were negative. Uptake of 201Tl in these metastases is at least partially, unrelated to the TSH and thyroglobulin levels or to the 131I-accumulating capacity. Scintigraphy using 201Tl might be helpful for the detection of metastatic thyroid carcinoma in those cases where 131I uptake is absent.

Adenocarcinoma↗