Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Growth hormone releasing hormone (GHRH) has recently been isolated and sequenced from pancreatic tumors secreting GHRH. Patients with untreated acromegaly due to a pituitary tumor respond to exogenous administration of GHRH with a further rise of their elevated basal growth hormone (GH) levels. For the first time, we report the effects of exogenously administered synthetic GHRH in a patient with acromegaly due to a GHRH secreting pancreatic tumor. The diagnosis was established by high peripheral IR-GHRH levels (1100 pg/ml) and an arterio- venous tumor gradient of IR-GHRH. In this patient GH failed to respond to 1 microgram/kg of exogenous GHRH with the pancreatic tumor in situ; however, further increase of serum GH levels occurred after TRH administration, hypoglycemia and oral glucose administration. After removal of the tumor, serum GH levels decreased and a normal response to GHRH and TRH were demonstrated. The extract of the tumor contained 1.7 micrograms IR-GHRH per g wet tissue. Thus, lack of response to exogenous GHRH in untreated acromegaly may indicate the presence of an ectopic GHRH producing tumor.
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PMID:Failure to respond to growth hormone releasing hormone (GHRH) in acromegaly due to a GHRH secreting pancreatic tumor: dynamics of multiple endocrine testing. 392 12

Prolactin secretion in normal adults is characterized by periods of episodic secretion which increase in magnitude during sleep. In this study, we report the 24-h mean prolactin concentrations, prolactin secretory patterns, and associated pituitary hormone function in nine patients (seven women and two men) with hyperprolactinemia of diverse etiologies. Four of the women and one of the men had clinically demonstrable pituitary tumors, one boy had a hypothalamic tumor, and the three other women had "functional" hyperprolactinemia. The 24-h mean prolactin concentrations derived from averaging the 20-min interval samples for 24 h ranged from 28.6 to 1,220 ng/ml. The plasma prolactin patterns in these patients showed persistence of episodic secretion in all and loss of the normal sleep-wake difference in plasma prolactin in seven of nine. Three of the patients with galactorrhea and comparable 24-h mean prolactin concentrations (58.3, 59.7, and 64.3 ng/ml) showed similar prolactin secretory patterns despite different etiologic mechanisms. Evaluation of the secretory patterns of luteinizing hormone (LH) in these patients showed loss of normal pulsatile LH release and a low 24-h mean LH concentration in the patient with the pituitary tumor, while the two patients without clinically demonstrable pituitary tumors ("post-pill" galactorrhea and "idiopathic" galactorrhea) showed normal LH secretory patterns and 24-h mean LH concentrations. The 24-h mean cortisol concentrations and secretory patterns were normal in five of the seven patients who had these parameters measured. The patient with the hypothalamic tumor had a low 24-h mean cortisol concentration and production rate and absent response to metyrapone. The patient with "idiopathic" galactorrhea had an elevated 24-h mean cortisol concentration but normal cortisol production rate and urinary 17-hydroxycorticoid excretion. Growth hormone secretion was abnormal in four of the patients (one with the hypothalamic tumor and three with pituitary tumors). Thyrotropin-releasing hormone (TRH) administration in four patients resulted in normal TSH release in two patients (one of whom developed galactorrhea after the test), an absent response in the patient with the hypothalamic tumor, and a blunted response in one of the women with a pituitary tumor. The two men had low 24-h mean plasma testosterone concentrations (69 and 30 ng/100 ml) and symptoms of impotence and loss of libido. Five of the women (four with pituitary tumors and one with Chiari-Frommel syndrome) had either low 24-h mean LH concentrations, abnormal LH secretory patterns, or both. These data indicate that patients with hyperprolactinemia encompassing a varied etiological range frequently show loss of the normal sleep-associated increase in prolactin secretion as well as abnormalities in the regulation of the other hypothalamic pituitary-regulated hormones. The finding that the abnormalities in LH, growth hormone, thyrotropin, and cortisol (adrenocorticotrophic) secretion were almost uniformly confined to the patients with the clinically demonstrable hypothalamic or pituitary tumors suggests that the size of the lesion is the critical factor.
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PMID:Hypothalamic-pituitary function in diverse hyperprolactinemic states. 420 70

A radioligand-receptor system for luteinizing hormone (LH), USING transplantable mouse luteoma, was used to investigate the interactions of LH, other peptide hormones, and LH subunits. Since tumor size decreased as did production of androgenic hormones following hypophysectomy, the luteoma is believed to have been dependent on pituitary tropic hormones; posthypophysectomy histologic changes supported this conclusion. An homogenate was prepared from 1-4 gm luteomas, which had been borne by mice for 4-10 months. Ovine LH, bovine LH, and human chorionic gonadotrophin reduced the binding of iodine-125 human luteinizing hormone (125-I-hLH). Growth hormone, adrenocorticotrophic hormone, and prolactin had no capacity to interfere with binding of 125-I-hLH. Though follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) reduced the binding somewhat, the reductions were consistent with the known presence of contaminating amounts of LH in the FSH and TSH. The accumulated results of a number of experiments suggest that binding to the luteoma LH receptor requires a particular polypeptide structural conformation, one found in the native hormone but found in neither alpha nor beta subunit alone.
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PMID:Gonadotropin receptor of a mouse luteoma: interactions with luteinizing hormone (LH) and its and subunits. 435 8

Hypophysectomy was studied for its possible effects on cancer by alt eration of the endorcines at the New York Hospital-Cornell Medical Center beginning in 1953. The major effort has been the treatment of 850 cases of metastic breast cancer. In 80 patients with other types of metastatic cancer benefit was found only in 50 cases of prostatic cancer. Prolactin is mediated directly from the anterior pituitary to breast tissue where it aids and abets the growth of breast cancer; its secretion is largely dependent on the estrogen produced in ovaries and adrenals. In humans estrogen given after total hypophysectomy is found to be ineffective in altering metastases. Growth hormone is also produced in the anteriod lobe of the pituitary but its production is not dependent on an estrogen feed-back mechanism. If the primary cancer is dependent on the presence of prolactin, failures with hypophysectomy are explained the tumor having gained autonomy and being no longer so dependent. Contraindications to hypophysectomy include extensive pulmonary, liver, or brain metastases and any systemic disease that would preclude major surgery. Following a remission after oophorectomy, another remission with hypophysectomy may often be obtained. Neither the pathological type of a breast cancer nor the location of metastases alter the results. However the longer the interval between mastectomy and reactivation of the tumor, the more favorable the outlook. Maintenance substitution therapy following removal of the pituitary employs daily hydrocortisone, 17.5 mg orally, or equivalent steroid preparations. The mortality rate is 2% in the first 30 days after operation. In 88 patients evaluated 2 years after operation those who had received a remisssion lasting over 6 months survived nearly 5 times longer than those unbenefitted by the operation. The intracranial procedure is preferred. In cases of failure or when a remission terminates, male hormone therapy, chemotherapy, or radiation may have limited value.
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PMID:Hypophysectomy for metastatic cancer. 466 60

Tumors from 42 surgically resected pituitaries and from 13 autopsy cases were studied immunohistochemically with polyclonal antisera to 7 anterior pituitary hormones and with a newly developed monoclonal antibody directed against human chromogranin for evaluation of the distribution of chromogranin in normal and neoplastic pituitaries. In addition, a prospective study was done for assessment of the prevalence, morphology, and endocrine cell types of pituitary tumors in 100 autopsy subjects. When these 55 pituitary adenomas were examined with monoclonal antibody (LK2H10) directed against human chromogranin, selective staining of normal adenohypophyseal cell types and pituitary tumors was observed. Most null-cell adenomas (12/14) were positive for chromogranin, whereas all prolactin (PRL)-producing adenomas (19/19) were negative. Growth hormone (GH) adenomas were focally positive (9/9). All oncocytomas (2/2), 1 thyrotropin (TSH) adenoma, and a follicle-stimulating hormone/luteinizing hormone adenoma were positive for chromogranin. One or more adenomas were present in 14% of the autopsy cases. The tumors occurred most frequently in patients in the fifth through the seventh decades of life. Immunohistochemical staining of 13 adenomas revealed 1 TSH, 1 ACTH, and 4 PRL-producing tumors, whereas 7 other tumors, which were null-cell or undifferentiated adenomas, failed to stain for any of the seven principle pituitary hormones. These results indicate that antibody LK2H10 to human chromogranin is useful in the immunohistochemical characterization of pituitary adenomas. Incidental pituitary microadenomas from autopsy-derived pituitaries most commonly produce PRL, or they belong to the null-cell or undifferentiated tumor group.
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PMID:Pituitary adenomas. An immunohistochemical study of hormone production and chromogranin localization. 608 68

This work outlines the endocrine abnormalities associated with intracranial germinomas (14 patients before treatment). Diabetes insipidus of various intensity was present in all cases. Adipsia is often present as well. In six patients, the first neuroradiologic examination after the onset of DI was normal. Growth hormone secretion was deficient in 11 of 13 patients. Abnormalities of TSH response to TRH were present in nine of ten (four insufficient and five exaggerated responses to TRH). Anterior pituitary dysfunction could not be predicted by the tumor site as determined by radiologic criteria. Tumoral markers have also been studied. Elevated plasma tumoral markers were found in four patients of 11 studied. Tumoral germinoma cells were present in CSF in five patients of ten, in one of them before radiologic confirmation. Pertinent endocrine evaluation and search for tumoral markers was of great value in systematic follow-up of patients with central diabetes insipidus, and could lead to early diagnosis and treatment of the tumor.
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PMID:Endocrine aspects and tumoral markers in intracranial germinoma: an attempt to delineate the diagnostic procedure in 14 patients. 618 Jan 56

Growth hormone (GH)-releasing activity has been detected in extracts of carcinoid and pancreatic islet tumors from three patients with GH-secreting pituitary tumors and acromegaly. Bioactivity was demonstrated in 2 N acetic acid extracts of the tumors using dispersed rat adenohypophyseal cells in primary monolayer culture and a rat anterior pituitary perifusion system. The GH-releasing effect was dose responsive and the greatest activity was present in the pancreatic islet tumor. Small amounts of activity were also found in two other tumors (carcinoid and small cell carcinoma of lung) unassociated with GH hypersecretion. Each of the tumors contained somatostatin-like immunoreactivity but the levels did not correlate with the net biologic expression of the tumor. Sephadex G-75 gel filtration indicated the GH-releasing activity to have an apparent molecular size of slightly greater than 6,000 daltons. The GH-releasing activity was adsorbed onto DEAE-cellulose at neutral pH and low ionic strength, from which it could be eluted by increasing ionic strength. The GH-releasing activity was further purified by high pressure liquid chromatography using an acetonitrile gradient on a cyanopropyl column to yield a preparation that was active at 40 ng protein/ml. Partially purified GH-releasing activity, from which most of the bioactive somatostatin had been removed, increased GH release by pituitary monolayer cultures to five times base line. Enzymatic hydrolysis studies revealed that the GH-releasing activity was resistant to carboxypeptidase, leucine-aminopeptidase, and pyroglutamate-amino-peptidase but was destroyed by trypsin and chymotrypsin, indicating that internal lysine and/or arginine and aromatic amino acid residues are required for biologic activity and that the NH2-terminus and CO9H-terminus are either blocked or not essential. The results provide an explanation for the presence of GH-secreting tumors in some patients with the multiple endocrine neoplasia syndrome, type I, and warrant the addition of GH-releasing activity to the growing list of hormones secreted by tumors of amine precursor uptake and decarboxylation cell types.
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PMID:Partial purification and characterization of a peptide with growth hormone-releasing activity from extrapituitary tumors in patients with acromegaly. 624 40

A deficiency in growth hormone depresses growth and leads to dwarfism. The cause of hypopituitarism may be the destruction of the hypothalamus by a tumor infection or trauma. Birth trauma is often the underlying cause. Genetic forms or cerebral defects have also been described. Growth hormone may be completely lacking or partially reduced. Neurohormonal dysfunction is of particular interest. Administration, either intramuscular or subcutaneously, of human growth hormone leads initially to "catch-up" growth and to subsequent normal growth. Early treatment should be instituted if normal adult height is to be achieved.
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PMID:[Therapy of endocrine diseases in childhood and adolescence. 4: Hypophyseal dwarfism]. 643 53

A 28-year-old man was admitted to the Kyushu University Hospital with an episode of severe headache. When driving a car, he suddenly developed severe headache and this was followed by nausea and vomiting. he had been quite well except for slightly decreased libido before this episode. On admission, he showed galactorrhea. The pubic and axillary hairs appeared normal and the development of the external genital organs seemed normal. However, the movement of the sperma was decreased. Ophthalmologic examination was negative. Endocrinological studies revealed hyperprolactinemia of 697 ng/ml, and the serum prolactin level was suppressed by bromocriptine and L-DOPA loading test. The serum testosterone level was 282 ng/dl. Growth hormone and gonadotropin levels were normal. Plain films of the skull and tomograms of the sella showed double floor and slight ballooning. CT scan showed an isodensity mass in and above the sella, and this mass was slightly enhanced with contrast media. The suprasellar extension was better demonstrated by metrizamide cisternography and CT. The diagnosis of prolactinoma was made, and a radical removal of the tumor was done through the transsphenoidal route. During surgery, dark reddish fluid was aspirated in an amount of 1.8 ml. Histologically the tumor was chromophobe adenoma, and immunohistochemical stain revealed prolactin granules in the majority of the tumor cells. Postoperative serum prolactin level decreased to 150 ng/ml and finally returned to normal by administration of 2.5 mg of bromocriptine. The serum testosterone level was slightly elevated. The movement of the sperma showed no improvement. There were no postoperative complications such as hypopituitarism and CSF rhinorrhea. The usefulness of combination therapy of operation and medication with bromocriptine was suggested.
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PMID:[A case of prolactinoma with galactorrhea in man]. 654 Mar 73

Growth hormone (GH) is a potent antagonist of insulin action, and this resistance occurs primarily at a post-binding step(s). To elucidate the underlying mechanisms, the effects of chronic GH excess on the structure and function of insulin receptors partially purified from the liver were examined in rats harboring GH-secreting tumors. Insulin resistance was established in this animal model of GH hypersecretion by a hyperinsulinemic euglycemic clamp. Specific binding of 125I-insulin and receptor number were reduced in tumor animals by 40% and 62%, respectively, reflecting downregulation of the insulin receptor by hyperinsulinemia in these animals. Receptors from tumor animals showed a 50% increase in beta-subunit phosphorylation and in the kinase activity toward the synthetic polypeptide Glu4:Tyr1 when measured in vitro in the absence of insulin; however, the incremental stimulation by insulin (170 nmol/L) of the phosphorylation of either the beta-subunit or Glu4:Tyr1 was not different between control and experimental animals. There was no difference between the two groups in Glu4:Tyr1 phosphorylation measured after immunodepletion of receptors by antibodies to the insulin receptor, indicating that the observed alteration in the kinase activity of tumor animals was intrinsic to the insulin receptor. Exposure to chronic GH excess did not alter insulin receptor structure, as evidenced by electrophoretic mobility under reducing and nonreducing conditions. The enhanced basal kinase activity of the receptor from tumor animals may reflect a more highly phosphorylated state of the receptor (and hence elevated enzyme activity) in these animals due to elevated serum insulin levels. These results demonstrate that the hepatic insulin resistance in rats chronically exposed to GH excess is not due to impaired insulin receptor kinase activity.
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PMID:Insulin resistance in rats harboring growth hormone-secreting tumors: decreased receptor number but increased kinase activity in liver. 785 69


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