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)

A patient with neurofibromatosis involving the small bowel who developed adenocarcinoma in an area of the ileum showing diffuse involvement of the disease is presented. Unlike the five cases with this association previously described, the present case shows a neuroendocrine component within the adenocarcinoma. The relation between neurofibromatosis of the bowel wall and adenocarcinoma may be explained by a decreased intestinal transit time in this patient. The presence of a carcinoid tumor in the ileum is not unusual in a patient with von Recklinghausen's disease, although the location of the carcinoid in the duodenum is described more frequently in these patients. The appearance of endocrine/neuroendocrine features within an adenocarcinoma already involved by diffuse neurofibromatosis is exceptional and may not be a chance event.
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PMID:Neurofibromatosis involving the small bowel associated with adenocarcinoma of the ileum with a neuroendocrine component. 130 Jun 7

A family of growth arrest specific (Gas) genes was operationally defined on the basis of the strategy utilized to isolate them e.g. differential expression in quiescent and growing cells. Our interest in the Gas-3 gene was prompted by our previously reported localization of the gene on the mouse chromosome 11.44 +/- 1.9 cM proximal to the Trp53 locus and by the finding, by others, that it codes for a myelin protein and that a point mutation in its fourth putative transmembrane region is associated with the trembler mutation. We have isolated the human homologous of the mouse Gas-3 gene and utilized the cloned sequences as a probe to localize the gene on human chromosomes both by analysis of human-rodent somatic cell hybrids and in situ hybridization of human metaphases. We have now localized the human Gas-3 gene on chromosome 17p12-13. Its possible role in both the development of neoplasia in neurofibromatosis patients and in the myelin degenerative disease as the Charcot-Marie-Tooth is discussed.
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PMID:Isolation and mapping to 17p12-13 of the human homologous of the murine growth arrest specific Gas-3 gene. 130 10

Schwannomatosis is a rare disorder, still not quite well defined, seldom described in the literature. In this paper we report the case of male. Patient, 52 years old, who in the last 30 years developed five subcutaneous tumors within his limbs peripheral nerves, which histologically proved to be schwannomas. A brain computed tomography showed a partially calcified tumor in the left temporal lobe which most likely was a meningioma. A thorough clinical examination was unable to find signs of type I or type II neurofibromatosis. The present condition, probably a form of phacomatosis, has to be distinguished from neurofibromatosis and is considered as an independent clinical entity whose origin still awaits further detailed investigations.
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PMID:[Schwannomatosis: report of a new case]. 130 64

Membrane-bound alkaline phosphodiesterase I was investigated in control fibroblasts and tumor-derived fibroblasts from patients with neurofibromatosis. Alkaline phosphodiesterase I activity of tumor-derived cells increased in a dose response to nicotinamide (0-9 mM) in culture; 5'-thymidine p-nitrophenyl phosphate was used as substrate. The enzyme activity increased 1.7-fold after 30 h of incubation with 9 mM nicotinamide, and after 3 weeks increased 5-fold. The nicotinamide-dependent enhancement of alkaline phosphodiesterase I activity was inhibited by actinomycin D, which specifically blocks RNA synthesis, but not by cycloheximide. These results suggest that the increase in the enzyme activity caused by nicotinamide was due to induction of alkaline phosphodiesterase I at the transcriptional level in tumor-derived cells. The metabolic effect of nicotinamide on alkaline phosphodiesterase I may be related to tumorigenicity in neurofibromatosis.
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PMID:Nicotinamide-induced activity of alkaline phosphodiesterase I toward tumor-derived cultured cells from neurofibromatosis patients. 132 1

Tumors of nerves are classified into benign (schwannoma and neurofibroma) and malignant nerve sheath tumors. Schwannomas almost always occur as solitary lesions, whereas neurofibromas may occur alone or in a greater number, especially in patients with the peripheral form of von Recklinghausen's disease. Benign nerve sheath tumors often present as asymptomatic, slowly growing soft tissue masses. Although malignant nerve sheath tumors are relatively rare, a sudden increase in the size of a lesion, in particular in a patient with neurofibromatosis, should raise the suspicion of malignant change. On computed tomography (CT) and magnetic resonance imaging (MR) a benign nerve sheath tumor usually appears as a well-defined, oval, spherical or fusiform mass with smooth borders and distinct outlines, located in the subcutaneous tissue or centered at the expected anatomic location of a nerve, with displacement of adjacent soft tissues. Generally nerve sheath tumors have a low density on unenhanced CT scans. On MR they are isointense to muscle on T1-weighted images, whereas on T2-weighted images the signal intensity is high. Both on CT and MR the degree of contrast enhancement is moderate to marked and may be homogeneous or inhomogeneous. MR has become the method of choice for evaluating the anatomic location, contour, and relation of a nerve sheath tumor to adjacent neural, vascular, and muscular structures. The imaging criteria for malignant nerve sheath tumors are not specific enough to distinguish them from other malignant soft tissue tumors, so that neither CT nor MR can establish a definite diagnosis.
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PMID:Nerve sheath tumors: evaluation with CT and MR imaging. 133 65

A predisposition to the development of certain specific and familial cancers is associated with the inheritance of a single mutated gene. In the best-characterized cases, this primary mutation is a loss of function mutation consistent with viability but resulting in neoplastic change consequent to the acquisition of a second somatic mutation at the same locus. Such genes are referred to as tumor-suppressor genes. Classical examples are the Rb-1 gene associated with the development of retinoblastoma and the p53 gene, which is associated with a wider range of neoplasms, including breast cancer. Other tumor-suppressor genes have been isolated which are associated with Wilms' tumor, neurofibromatosis, and inherited and sporadic forms of colorectal cancer. Some of these genes appear to act as negative regulators of mitotic cycle genes, and others may have different properties. The nature of these genes is discussed, as is the evidence for the involvement of tumor-suppressor genes in other inherited, and sporadic, forms of cancer. Some recent data on the Wilms' tumor gene, WT1, and on the involvement of the p53 gene in breast cancer are presented, and the importance of genomic imprinting in contributing to the excess of suppressor gene mutations in chromosomes of paternal origin is considered.
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PMID:Tumor-suppressor genes: cardinal factors in inherited predisposition to human cancers. 133 26

Pheochromocytoma is a cause of hypertension that frequently can be cured by surgery. The aim of this paper, based on 5 cases of pheochromocytoma, is to relate our experience in diagnosis and treatment in this pathology. In four of 5 patients with pheochromocytoma we observed unusual characteristics of the disease. Association with neurofibromatosis in one case, with rheumatic mitral regurgitation in another; and in a third case the tumor was malignant. One patient had catecholamine-mediated electrocardiographic changes which disappeared with treatment. Since symptoms of adrenergic hyperactivity were present in all cases, the rise in the levels of vanilmandelic acid and urinary metanephrines were useful in confirming the diagnosis. Computed tomography and I-131 meta-benzylguanidine for radioisotopic imaging, displayed not only all tumoral masses but also bone metastases in the malignant case. During the follow-up period, from the sixth month to the fourth year after surgery, four patients were asymptomatic, and have normal urinary catecholamine metabolite levels. The patient with a malignant form of pheochromocytoma continued to show elevated catecholamines release and remained hypertensive in spite of adrenal mass resection.
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PMID:[Pheochromocytoma. Its diagnostic and therapeutic characteristics]. 134 Jul 39

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).
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PMID:Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis. 134 57

Pheochromocytomas occur sporadically or in individuals affected by inherited syndromes including multiple endocrine neoplasia (MEN) type 2A and 2B, neurofibromatosis, and the von Hippel-Lindau syndrome (vHL). Medullary thyroid carcinomas (MTCs) also occur sporadically or as part of MEN 2A, MEN 2B, and familial MTC. Little is known of the molecular genetic background of these tumors. We have shown previously that activation of the N-ras, H-ras, and K-ras oncogenes does not occur in these tumors, but that deletions of the short arm of chromosome 1 are extremely common (> 60%) and may indicate loss of a suppressor gene in the chromosomal region 1p31-36. We have examined the structure and expression of N-myc, c-myc, L-myc, c-mos, nerve growth factor (beta-NGF), and the low affinity nerve growth factor receptor (LNGFR) in a series of pheochromocytomas and MTCs from patients with hereditary and sporadic diseases. Southern analysis, using radiolabeled DNA probes, revealed no evidence of amplification or rearrangement of these genes in any normal or tumor tissues except for loss of heterozygosity at the L-myc locus (1p32) in 9 pheochromocytomas from patients with MEN 2A or MEN 2B, in 5 of 11 non-MEN pheochromocytomas, and in 3 of 24 non-MEN MTCs. Gene expression at the RNA level was examined by Northern analysis or ribonuclease protection assay (RPA) using radiolabeled DNA or cRNA probes. C-myc transcripts were detectable at low levels in all tumors tested.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oncogene and growth factor expression in MEN 2 and related tumors. 136 25

Two cases of subependymoma in the cervical spinal cord associated with stigmata of neurofibromatosis are reported. Magnetic resonance (MR) imaging showed one tumor with a sharp margin, which was well-demarcated intraoperatively and was totally removed. MR imaging showed the other tumor with an irregular margin, which was partly invasive at operation. Subependymomas are rare in the spinal cord and these are the first reported associations with neurofibromatosis.
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PMID:Intramedullary subependymoma with neurofibromatosis--report of two cases. 137 43


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