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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the interaction between dopamine and estradiol on PRL release by cultured normal and tumorous PRL-secreting cells prepared from human pituitaries. If pituitary glands were obtained within 3 h after sudden death of previously normal individuals, the viability of isolated pituitary cells prepared by dispersion with dispase was more than 75%. After 4 days of culture, dopamine (500 nM) inhibited PRL release by cells prepared from four normal pituitaries by 24 +/- 3% (+/- SEM). Pretreatment of the cells with 100 nM estradiol did not alter dopamine-mediated inhibition of PRL release. Estradiol alone increased basal PRL release and cell PRL content. Cultured PRL-secreting pituitary tumor cells, obtained by transsphenoidal operation from four patients, were similarly sensitive to dopamine. Estradiol stimulated tumor cell PRL release and content, but significantly diminished the inhibitory effect of dopamine. The estrogen receptor blocker tamoxifen did not alter PRL release, but it did reverse the estradiol-induced insensitivity of the prolactinoma cells to the dopamine agonist bromocriptine. In conclusion, these in vitro results indicate that estrogens do not antagonize the effect of dopamine on normal human PRL-secreting pituitary cells. In human pituitary tumor cells, however, estradiol decreased the sensitivity of PRL release to dopamine (agonists), and the estrogen action can be acutely reversed by tamoxifen.
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PMID:Differences in the interaction between dopamine and estradiol on prolactin release by cultured normal and tumorous human pituitary cells. 378 22

The effect of chronic hyperestrogenism on gonadal function was studied in three men who had estrogen-secreting Leydig cell tumors before unilateral orchidectomy and for 11-43 months after surgery. All three men had low plasma gonadotropin and testosterone levels and increased estradiol levels. Impairment of testicular steroidogenesis was also suggested by increased progesterone to 17-hydroxyprogesterone and 17-hydroxyprogesterone to androstenedione ratios in both spermatic venous plasma and the medium of Leydig tumor cells from one patient incubated in vitro. Before surgery, spermatogenesis was abnormal in two men. Testicular endocrine function and spermatogenesis did not return to normal after surgery. During the follow-up period, plasma gonadotropin levels were high in all three men, and testosterone was low normal. Estradiol levels decreased to normal immediately after surgery and then returned to the upper normal limit. The response to hCG stimulation in one man was subnormal. We conclude that chronic hyperestrogenism produced hypothalamo-pituitary inhibition as well as direct steroidogenic blockade at the testicular level. Long term impairment of both endocrine and exocrine testicular functions may be secondary to slowly reversible (or irreversible) estrogen-induced damage to tubular and Leydig cells.
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PMID:Feminizing testicular Leydig cell tumor: hormonal profile before and after unilateral orchidectomy. 381 98

This article presents the case of a 30-year-old woman who developed halo cutaneous melanoma. She had been taking oral contraceptives (Norinyl) for about 5 years before diagnosis. Following wide excision of the melanoma, the patient remained clinically free of tumor for 5 years. However, in a subsequent pregnancy, she developed metastases to the liver that became evident in the immediate postpartum period. Long-term survival associated with cutaneous hypopigmentation has been reported and occurred in this patient. There is considerable debate as to whether oral contraceptives or pregnancy can influence the occurrence and course of melanoma. Also unclear is whether oral contraceptive use or a subsequent pregnancy in women with a history of melanoma will accelerate the growth of latent metastases, stimulate a benign pigmented lesion to become malignant, or cause a previously removed melanoma to recur and metastasize. Given the lack of uncertainty in this area, it is recommended that women with a history of melanoma use a nonhormonal method of contraception. Frequent follow up and thorough physical examinations during pregnancy are essential, and any suspicious skin lesions should be biopsied early. To better answer the questions raised by cases such as this, establishment of an organized mechanism for the registry of patients with melanoma who subsequently become pregnant is suggested. A cooperative prospective melanoma study could accumulate the necessary data on tumor site and thickness, staging, parity, and the use of hormonal contraception.
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PMID:Pregnancy and hormonal influences on malignant melanoma. 381 62

To study the local regulatory mechanisms involving steroid hormones in steroidogenic cells, the effect of estradiol on steroidogenesis was investigated using MA-10 Leydig tumor cells. Estradiol inhibited progesterone biosynthesis in MA-10 cells in a dose-dependent manner. Inhibition of progesterone biosynthesis by estradiol was associated with a concomitant accumulation of pregnenolone in the incubation medium. Estradiol inhibited the activity of 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase by a chemical mechanism which is not mediated through the cellular estrogen receptor. Thus, the estrogen receptor agonist diethylstilbestrol did not inhibit this enzyme activity, nor could this agent block the effect of estradiol on the enzyme. Furthermore, estradiol inhibited enzyme activity in isolated microsomes which do not contain estradiol receptor protein. Kinetic analysis of the inhibitory effect of estradiol on 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase revealed that this steroid hormone functions as a competitive inhibitor of the enzyme, with an average apparent Ki of 1.8 microM.
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PMID:Estradiol acts as a competitive inhibitor of the 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase enzyme of cultured Leydig tumor cells. 386 77

A patient with gynecomastia and a nonpalpable testicular Leydig cell tumor is presented. Estradiol and progesterone levels were elevated whereas serum testosterone was reduced. Following removal of the tumor the hormonal values returned to normal with reduction of gynecomastia. Tumor tissue was maintained in culture for 9 days during which high estradiol levels as well as lesser quantities of testosterone and progesterone were demonstrated in the culture medium. Elevation of progesterone supports a block of 17 alpha-hydroxylase activity caused by increased endogenous estradiol. This is the first case of a cultured feminizing testicular Leydig cell tumor in which hormone production was demonstrated. The freshly removed tumor as well as the cultured tissue material were studied by immunocytochemical methods and biochemical analysis of cytoskeletal proteins. These methods revealed vimentin as the exclusive type intermediate sized filament in both. This is the first demonstration of vimentin in a Leydig cell tumor, in agreement with its occurrence in normal Leydig cells.
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PMID:Characterization of a feminizing testicular Leydig cell tumor by hormonal profile, immunocytochemistry, and tissue culture. 389 59

The role of prolactin (PRL) in supporting the growth of human breast cancer is still unclear. The ability to grow primary breast cancer specimens in the soft agar clonogenic assay in the absence of serum gave us the opportunity to evaluate the growth-promoting effect of PRL and to compare it to that of estradiol in the same tumor samples. PRL was tested both at physiological concentrations (20 ng/ml) as well as in pharmacological amounts (200 ng/ml) comparable to circulating blood levels in hyperprolactinemic states. Estradiol was simultaneously tested in physiological amounts (10(-8)M). In 17 infiltrating ductal carcinomas, the lower dose of PRL stimulated colony formation to 126 +/- 5.2% (SE) of control, while the higher dose increased colony number to 159 +/- 10.4% of control. This latter effect was comparable to that observed with estradiol (159 +/- 8.5% of control). The effect of PRL was more pronounced in estrogen receptor-positive tumors. Nine of ten estrogen receptor-positive tumors were PRL sensitive, while three of seven estrogen receptor-negative tumors exhibited a clear response to PRL administration. PRL did not stimulate colony formation in a malignant cystosarcoma phylloides and in two benign lesions (fibroadenoma and fibrocystic disease). We conclude that, at least under the conditions of the soft agar clonogenic assay, PRL exerts a dose-dependent growth-promoting effect on human breast cancer. Such effect is comparable to that of estradiol when PRL is added in concentrations similar to circulating blood levels in hyperprolactinemic patients.
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PMID:Promotion by prolactin of the growth of human breast neoplasms cultured in vitro in the soft agar clonogenic assay. 394 57

Human prostatic cancer (HONDA) serially transplanted in nude mice grew well in male mice but not at all in untreated female mice or in castrated male mice. Progressive growth in female mice was obtained by i.m. administration of 1 mg of testosterone twice a week. Estradiol inhibited the growth of the tumor in male mice to some extent; however, some growth was observed. The tumor in untreated male mice retained the histological features of poorly differentiated adenocarcinoma. Tumors in castrated male mice showed reduction in size of tumor cell nests with relative overgrowth of stroma. The tumor in androgenized female mice consisted of columnar epithelial cells with large nuclei and more abundant cytoplasms and a large glandular lumen, showing histology of moderately differentiated adenocarcinoma. High levels of human prostatic acid phosphatase (PAP) were detected in sera from untreated male mice. Testosterone markedly increased the content of serum PAP of androgenized female mice. Estradiol reduced the levels of PAP in sera from untreated male mice regardless of the tumor weight. High-affinity androgen receptors were present in cytosol and in nuclear extract of the tumor in untreated male mice. No measurable amount of progesterone or estrogen receptors was present in cytosol from untreated male mice.
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PMID:Hormone dependency of a serially transplantable human prostatic cancer (HONDA) in nude mice. 402 85

The rationale for studying nuclear DNA may be its direct relationship to the aggressiveness of cancer. Recent flow cytometric studies (FCM) of cancer cells show the limitation of the current methods for the accurate determination of the degree of aneuploidy or proliferative characteristics of a tumor cell. Here we report a new methodology for a computerized determination which is well correlated with relative mean DNA content in cell populations analyzed by FCM (heterogeneity index, HI). A total of seventy-six tissue samples were examined. Twenty-two specimens were benign tissue while fifty-four were histologically malignant bladder tumors. Forty tumors were grade (G)I-II, ten G-III, and four carcinoma in situ. The samples were mechanically minced into a single cell suspension and stained with propidium iodide. An Ortho system 50-H multiparameter flow cytometer equipped with an Ortho 2150 computer was used to determine DNA content and cell number. HI was calculated using the following formulas: (formula; see text) The mean HIS of twenty-two normal and benign tissues was 9.805 +/- 5.6. The forty G-II tumors had a mean HIS of 23.576 +/- 26.519. Statistical differences were observed between benign tissue and G-I-II tumors (P = 0.0196). G-III tumors had a marked increase in HIS of 160.965 +/- 63.404. The limited study of four carcinoma in situ tumors showed a mean HIS of 45.4 +/- 9.5. Our computer extrapolation of flow cytometric DNA analysis quantifies an objective description of FCM characteristics and histochemical index which may distinguish the degree of tumor malignancy.
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PMID:Heterogeneity index score (HIS). New computerized method for classification of human bladder carcinomas using flow cytometry. 404 13

Estradiol and progesterone receptor levels were measured in 130 patients with stage III breast tumors before treatment and following preoperative radiation or chemotherapy. The data were evaluated versus the morphologic features of posttreatment pathomorphosis of tumor. Standard fractionated radiation (total dose of 70 Gy) was followed by pronounced postradiation pathomorphosis and a decrease in the level and incidence of steroid receptors in 72.7-87.5%. The essentially unchanged receptor profile of tumor following large-fraction (total dose-20 Gy) irradiation as well as presence of estradiol and progesterone receptors in the originally receptor-negative neoplasms after chemotherapy were matched by a slight degree of pathomorphosis.
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PMID:[Degree of manifestation of therapeutic pathomorphosis and the nature of the change in the estrogen and progesterone receptors after the radiation and chemotherapy of breast cancer]. 408 10

7 case reports of women with benign hepatic adenoma suggest that, since all of the women were taking oral contraceptives (OCs), there may be an association between ingestion of exogenous hormones and development of benign hepatoma of the liver. The cases were rapidly diagnosed by using hepatic arteriography; prompt, precise diagnosis is emphasized because, though the tumors are benign, they may cause serious, if not fatal, hemorrhage if left unchecked. Case 1 was a 26-year-old woman who had taken Enovid for 2 years, who presented with acute abdomen and impending shock. Coliotomy was performed, in which a left-lobe hepatic tumor was found; she underwent left hepatectomy and cholecystectomy and no evidence of recurrence was found 1 year later. Case 2 had been taking Oracon for a unknown time. Case 3, on OCs for 6 years, had a pedunculated mobile tumor removed. Case 4, 25 years old, had been taking Ovral for 6 months before diagnosis and excision of a right lobe liver tumor. Case 5, 5 years on combined OCs, required surgical intervention for a hypervascular mass. Case 6, taking a total of 8 years of OC therapy, was operated on for an hepatic mass which was a white-to-yellow hemorrhagic mass. Case 7, taking Enovid for 7 years, yielded a surgical specimen that was hemorrhagic, partly necrotic, and yellow-tan, about 10 cm in diameter.
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PMID:Possible association between benign hepatomas and oral contraceptives. 412 57


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