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)

Somatostatin receptors have been characterized on biopsy specimens from small-cell lung carcinoma (SCLC) and on cultured human SCLC cells. We recently described the in vivo visualization of various somatostatin receptor-positive tumors, such as carcinoids and endocrine pancreatic tumors, after injection of 123I-Tyr-3-octreotide, a radiolabeled somatostatin analog. In the present study, this imaging procedure using 123I-Tyr-3-octreotide is reported in 11 patients with lung tumors. In five of eight patients with SCLC (63%), we were able to demonstrate tumor deposits using 123I-Tyr-3-octreotide scintigraphy. Unexpected metastases were found in two patients. In one of three patients with SCLC in whom tumor was not visualized, nonvisualization may have been caused by tumor necrosis and recent radiotherapy. In one of two patients with malignant small-cell tumors as described by Askin, the neoplasm was visualized. Like SCLC, these tumors are thought to derive from neuroendocrine cells. In one patient, a squamous-cell carcinoma and a bronchial adenoma were not visualized. We conclude that in the majority of patients with SCLC, the tumor and its metastases can be visualized using 123I-Tyr-3-octreotide scintigraphy. However, the value of this new technique in terms of specificity and sensitivity requires further studies in a larger group of patients.
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PMID:Radioiodinated somatostatin analog scintigraphy in small-cell lung cancer. 165 97

This report describes the fine-needle aspiration (FNA) cytology of a case of adenocarcinoma resembling fetal lung in a 53-yr-old male, a very uncommon malignant tumor of the lung that is similar to an early stage of lung differentiation. FNA smears revealed relatively small, fairly uniform tumor cells appearing as cohesive cell groups and scattered, isolated cells, some of them showing a rosette or acinus pattern. In addition, clusters of larger cells with eosinophilic cytoplasm and prominent nucleoli existed contiguously with the small cells or separately. The possibilities of an unusual type of adenocarcinoma, carcinoid tumor, and pulmonary blastoma were suggested by the cytologic findings. Immunohistochemical studies performed on a resected tumor tissue showed immunoreactivity for alpha-fetoprotein, neuron-specific enolase, and somatostatin, and endocrine-type granules were found ultrastructurally. This type of adenocarcinoma is considered to have a histogenesis similar to that of pulmonary blastoma. To our knowledge this is the first reported case in the cytologic literature.
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PMID:Fine-needle aspiration cytology of pulmonary adenocarcinoma of fetal type: report of a case with immunohistochemical and ultrastructural studies. 165 59

Specific low-affinity high-capacity binding sites for gonadotropin-releasing hormone (GnRH) have recently been discovered in human breast and ovarian carcinomata. We checked whether similar binding sites are present in human endometrial cancer. Plasma membrane preparations were incubated with [125I,D-Ala6-desGly10]-GnRH-ethylamide in the presence or absence of unlabelled GnRH agonists or other peptides. GnRH-binding could be demonstrated in all 12 tumor samples tested. The mathematical analysis of the binding data was consistent with a single class of low affinity (Ka = (0.8-1.4) x 10(5) M-1) and high-capacity (Bmax = (134-142) x 10(-12) M/mg membrane protein) binding sites. Native GnRH had a similar affinity to the binding sites as the GnRH agonist used. Other peptides such as oxytocin, somatostatin and thyrotropin-releasing hormone did not crossreact with the binding sites. A photolabelled derivative of [D-Lys6]-GnRH was prepared with the bifunctional photolabile reagent (4-azidobenzyl)-N-hydroxysuccinimide. Photoaffinity labelling of endometrial carcinoma membranes and subsequent sodium dodecyl sulfate electrophoresis in 10% polyacrylamide gel revealed the presence of a single molecular mass component of 62 +/- 1.9 kDa. The appearance of this photolabelled binding site could be largely suppressed by the addition of unlabelled GnRH-agonist (10(-4) M) and thus represents the specific binding site for GnRH in endometrial cancer.
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PMID:Specific low affinity binding sites for gonadotropin-releasing hormone in human endometrial carcinomata. 165 55

The binding of 123I-Tyr-3-octreotide (SDZ-204-090; specific activity 1 mCi/nmol), a new somatostatin-receptor binding radiopharmaceutical, to human tumour membrane fractions was evaluated in presence of unlabeled Tyr-3-octreotide and octreotide (SMS-201-995; Sandostatin). Tumour tissue was obtained intraoperatively from 15 patients with different endocrine tumours (insulinoma, carcinoide, phaechromocytoma, hypophysal adenoma) and breast cancer. In equilibrium experiments, membrane fractions (200 micrograms protein/ml) were incubated with increasing concentrations of 123I-Tyr-3-octreotide (0.03-30 nM) in presence or absence of 5 microM of unlabeled agonist. Binding capacities ranged from 1-20 pmol/mg protein (Kd 4-100 nM). The IC50 values (2.5-112 nM versus 0.02-69 nM) were different for the octreotide and Tyr-3-octreotide indicating that octreotide was the better competitor as Tyr-3-octreotide for 123I-Tyr-3-octreotide binding sites. In ductal breast cancer high numbers of in vitro binding sites for the radiolabel were found. In initial clinical studies 123I-Tyr-3-octreotide was i.v.-injected (3 mCi) to 5 acromegaly patients with hypophyseal adenomas. Following rapid uptake by the liver, positive tumour imaging was obtained in 3 patients which correlated to computer tomographic findings. Positive images were obtained just some minutes after injection. Our results support recent data suggesting that the 123I-Tyr-3-octreotide would be a suitable receptor-radiopharmaceutical for the localization of endocrine tumours.
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PMID:Evaluation of somatostatin receptors in human cancer. 166

We report a patient with acromegaly who had severe, intractable headache unrelated to tumor size which dramatically resolved with the somatostatin analog octreotide. The analgesic effects of octreotide were neither related to significant inhibition of growth hormone nor influenced by naloxone. Our data suggest that octreotide should be considered in patients with intractable headache associated with pituitary adenomas. Mechanisms other than tumor size or interaction with the opioid system, such as non-opioid algesic peptide secretion, may be the explanation for severe head pain in some pituitary adenomas.
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PMID:Analgesic effect of octreotide in headache associated with acromegaly is not mediated by opioid mechanisms. Case report. 166 9

A rare case of small cell carcinoma (SCC) of the gallbladder combined with adenocarcinoma is reported. The patient was a 70-year-old Japanese man, who died of the disease shortly after the onset of symptoms. Autopsy disclosed a small tumor (1.0 cm in longest diameter) in the fundus of the gallbladder, with widespread metastasis. Histochemically, the tumor cells showed negative reactions for argyrophilic and argentaffin stainings, a weak immunohistochemical reaction only for neuron-specific enolase, and negative reactions for all of the other neurosecretory markers used, including neurofilament, chromogranin, somatostatin, gastrin and leu-7. However, electron microscopic examination revealed a few typical neurosecretory granules (NSG) in the cytoplasm of some tumor cells. We suggest that: 1. The presence of NSG in the cytoplasm of tumor cells is the most reliable diagnostic criterion for SCC. 2. SCC, at least the combined type, arises from a multipotential stem cell.
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PMID:Small cell carcinoma of the gallbladder combined with adenocarcinoma. 166 37

We present a case report on a 35-year-old patient in whom a malignant sympathetic paraganglioma of the organ of Zuckerkandl was the cause of severe hypertension with excessive perspiration at night. Since curative surgery was not possible medical treatment was initiated. Interferon alfa 2b (Intron A, Essex Pharma) and the somatostatin-analogue SMS 201-995 (Sandostatin, Sandoz) had no effect on catecholamine production and progression of the tumor. Treatment with alpha-methyl-para-tyrosin (MPT, [Metyrosin], Demser, MSD) turned out to be an effective and well tolerable therapy in this patient with peritoneal carcinosis. Clinical and hormonal progression of the paraganglioma resumed only after two years of therapy, which constitutes the longest documented period of time of successful MPT treatment. The superior efficacy of MPT in our patient should encourage postoperative medical treatment with MPT in malignant pheochromocytoma or malignant paraganglioma, particularly when the tumor turns out to be resistent to alpha blocking drugs.
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PMID:[Therapy of a malignant sympathetic paraganglioma of the organ of Zuckerkandl--a case report]. 166 29

A 31-year-old patient with a clinical picture of obstructive jaundice had surgical treatment, and a primary carcinoid of the ampulla of Vater (VA) was found. The tumor was studied with light microscopy, immunohistochemistry, and electron microscopy. The neoplasm had histopathologic and cytopathologic features similar to those encountered in typical neuroendocrine neoplasms. It is interesting that immunohistochemical techniques disclosed the presence of vasointestinal polypeptide, cholecystokinin, and bombesin; however, unlike most neuroendocrine neoplasms arising in VA, no somatostatin-immunoreactive cells were found.
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PMID:Neuroendocrine carcinoma of the ampulla of vater. A case of absence of somatostatin in a vasoactive intestinal polypeptide-, bombesin-, and cholecystokinin-producing tumor. 167 Sep 74

Somatostatin is a naturally occurring cyclic tetradecapeptide that inhibits release of growth hormone and all gastrointestinal hormones. The beneficial effect of somatostatin in the treatment of certain hypersecretory disorders of hormone excess in well recognized; however its clinical usefulness has been limited in the past by its extremely short plasma half-life. The development of long-acting somatostatin analogues has provided clinically useful agents for treatment of hormone-producing tumors. In addition to well-known inhibiting effects on hormone release and actions, recent studies using experimental tumor models have demonstrated an antiproliferative effect of somatostatin and its analogues on growth of a variety of neoplasms. The exact role of somatostatin analogues in cancer therapy has yet to be established; however studies suggest that these agents could provide a useful and relatively nontoxic adjuvant therapy in the treatment of certain tumors. In this review, the oncologic application of somatostatin and possible mechanism of action are examined and current clinical and experimental studies are summarized.
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PMID:Somatostatin and analogues in the treatment of cancer. A review. 167 11

To investigate cAMP-dependent regulation of somatostatin secretion and gene expression in the islets of Langerhans, we have correlated the effects of forskolin, theophylline, and (Bu)2cAMP (dbcAMP) on the secretion of somatostatin-like immunoreactivity (SLI), cAMP generation, and somatosatin mRNA (S-mRNA) accumulation by cultured rat islet cells and a rat somatostatin-producing islet tumor cell line (1027 B2). Additionally, we have compared these effects with those of phorbol esters. Forskolin induced large acute increases in cAMP levels in islet cells, whereas theophylline produced modest sustained elevations in cAMP. During 4-h exposure to islets cells, forskolin, theophylline, and dbcAMP produced time- and dose-related increases of up to 14-fold in SLI release and up to 5-fold in S-mRNA levels. The rate of increase in S-mRNA paralleled secretion and occurred with the following order of potency: forskolin greater than dbcAMP greater than theophylline. The analog 1,9-dideoxyforskolin, which is unable to activate adenylyl cyclase, produced a small increase in SLI release without affecting S-mRNA. The effects of short term increases in islet cAMP levels and SLI release on long term changes in S-mRNA accumulation were investigated in a 48-h study with forskolin. Pretreatment of islet cells for 30 min with forskolin evoked large acute increases in cAMP levels and SLI release. S-mRNA rose in a biphasic pattern, with an acute increase at 30 min followed by a secondary increase at 12-48 h. In 1027B2 cells, forskolin and theophylline generated large increases in cAMP levels. Despite this, the two agents as well as dbcAMP produced only slight (20-35%) stimulation of SLI release and S-mRNA accumulation. Phorbol 12-myristate 13-acetate and phorbol 12,13-dibutyrate evoked dose-dependent stimulation of SLI secretion of up to 4-fold from islet cells without altering S-mRNA. Both secretion and S-mRNA were unresponsive to phorbol esters in 1027 B2 cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Regulation of islet somatostatin secretion and gene expression: selective effects of adenosine 3',5'-monophosphate and phorbol esters in normal islets of Langerhans and in a somatostatin-producing rat islet clonal cell line 1027 B2. 167 73


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