Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pancreatic islet neoplasms are rare endocrine tumours. The most common type is of beta-cell origin and is known as insulinoma, which can be either benign or malignant. The majority of insulinomas arise sporadically, but a small proportion develop as part of the hereditary multiple endocrine neoplasia type 1 (MEN1) syndrome. As for many human tumours, the genetic events that occur during the initiation and progression of insulinoma are poorly known. The men1 gene product, menin, is deficient in most hereditary cases, but is not obviously affected in the majority of sporadic tumours. Activation of the proto-oncogenes c-myc and ras has been observed during malignant progression, but their role in tumour initiation remains unproven. To address these questions, transgenic mouse models have been increasingly used to explore molecular and genetic events that might also precipitate human neoplasia. Transgenic mice expressing SV40 large T-antigen (Tag) oncogene in beta-cells develop tumours in a multi-stage progression from hyperplasia, angiogenesis, to solid encapsulated tumours. However, Tag, which inactivates the key tumour suppressors p53 and Rb, is not known to be involved in the pathogenesis of human insulinoma. The proto-oncogene, c-myc is implicated in beta-cell growth in both diabetes and tumorigenesis. Activation of Myc appears to be an early event in progression of human insulinoma. The effect of deregulated Myc expression on adult beta-cells in vivo has recently been investigated by developing transgenic mouse models in which the activity of Myc can be regulated ectopically. Although Myc activation initially promotes both proliferation and apoptosis in pancreatic beta-cells, apoptosis is the predominant outcome, giving rise to islet involution and diabetes. Importantly, inhibiting Myc-induced apoptosis (by co-expression of Bcl-x(L)) leads to significantly enlarged islets, many becoming highly vascularized, hyperplastic and invasive. These results suggest that, in the pancreatic beta-cells, early suppression of apoptosis is essential for the survival of Myc-activated beta-cells and islet neoplasia.
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PMID:Oncogenic co-operation in beta-cell tumorigenesis. 1173 27

Pancreatic islet-cell tumors (ICTs) are rare malignancies usually recognized by specific clinical endocrinopathies. The purpose of this study is to evaluate our surgical experience with functioning pancreatic ICT in an academic referral center. Twenty patients (male:female 12:8) with a mean age of 53 years (range 26-82) underwent surgery for a functioning pancreatic ICT [gastrinoma (eight), multiple endocrine neoplasia (three), insulinoma (seven), glucagonoma (four), and VI-Poma (vasoactive intestinal peptide; one)] between June 1975 and March 2001. Signs and symptoms of hormonal excess were present in 95 per cent (19 of 20). One patient (glucagonoma) presented with obstructive jaundice and mild glucose intolerance. Elevated peptide levels were detected preoperatively in 65 per cent, including all patients with an insulinoma. Curative resections were attempted in 80 per cent including three procedures for insulinoma. Palliative procedures were performed in 20 per cent--all gastrinomas. One patient with an insulinoma had diffuse nesidioblastosis. Three patients (with gastrinoma, insulinoma, and glucagonoma) had lymph node-positive disease and three patients with gastrinoma had liver metastasis. The overall 30-day morbidity rate was 30 per cent and mortality rate 0 per cent. Symptomatic improvement was achieved in 90 per cent at a mean follow-up of 44 months. Two patients developed diabetes after a subtotal and a total pancreatectomy, respectively. Sixty-three per cent of patients who underwent an attempted curative resection are alive at a mean follow-up of 47 months (range 3-231) and all patients who underwent a palliative procedure are alive at a mean follow-up of 31 months (range 27-36). Functioning pancreatic ICTs are fascinating tumors that produce distinct clinical syndromes. Symptomatic improvement is accomplished in the majority of patients after surgery and short-term palliation is achieved in patients with nonresectable disease.
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PMID:Surgical experience with functioning pancreatic neuroendocrine tumors. 1220 98

Genetic defects in genes encoding hormones, hormone receptors or polypeptides of the signaling pathways usually cause complex disease manifestations characterized by the involvement of several tissues and variable expression. Genetic aberrations, like chromosome aneuploidy, gene translocations or mutations in key regulatory proteins (even if not directly affecting genes of the endocrine system) often lead to clinical symptoms, including central endocrine functions like sexual differentiation or metabolic disturbances, like diabetes mellitus. But also minor genetic alterations like point mutations can affect the function of gene products to cause endocrine diseases. If the underlying molecular defects of endocrinopathies are known, direct molecular diagnosis can be performed. This is particularly useful if it helps to solve difficult differential diagnosis problems or if there exist effective preventive therapeutic options. The present paper presents examples for endocrine diseases in which molecular testing significantly increases the specificity and sensitivity of diagnostics and demonstrates the benefits for the patients and the healthcare system. In multiple endocrine neoplasia type 2, an unambiguous identification of gene carriers in affected families can be achieved by genetic testing. As a preventive measure to avoid medullary thyroid carcinoma, prophylactic thyroidectomy is recommended for individuals carrying the disease causing mutation. In adrenogenital syndrome, sequence analysis of the steroid 21-hydroxylase gene has become an important tool to confirm or exclude suspected late-onset forms of the disease, where hormone measurements are not informative. The major benefit, however, lies in identifying heterozygous carriers and providing a reliable prenatal test for couples carrying a defect in the 21-hydroxylase gene. Today, prenatal treatment with dexamethasone, which prevents the virilization in female fetuses, should always be based on results from molecular diagnosis performed from chorionic villus samples.
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PMID:Clinical impact of molecular diagnostics in endocrinology. Polymorphisms, mutations and DNA technologies. 1243 89

Early diagnosis of medullary thyroid carcinoma (MTC) can improve long-term prognosis. MTC can be detected at an early stage by calcitonin screening in all patients with thyroid nodules. This approach, however, is controversial due to high costs and a limited specificity of calcitonin. It was the aim of the present study to investigate whether ultrasonography may contribute to the diagnosis of MTC in patients with thyroid nodules. The study included 19 patients with newly diagnosed MTC. Ten patients had sporadic MTC, 7 had multiple endocrine neoplasia (MEN) type 2A, and 2 patients had MEN 2B. In all subjects conventional ultrasound, and in 14 patients color Doppler sonography were performed before primary surgery. For comparison, ultrasound appearance of 139 benign thyroid nodules was evaluated. In conventional ultrasound, MTC in 17/19 (89%) patients were hypoechoic, contained intranodular calcifications, and had no "halo sign". The combination of these criteria were found in only 8/139 (6%) of benign thyroid nodules. Intranodular blood flow was found in 11/14 patients with MTC (79%), perinodular blood flow in 7/14 MTC (50%). In conclusion, conventional ultrasound reveals a combination of hypoechogenicity, intranodular calcifications, and absence of "halo sign" in the vast majority of MTC. Since this sonographic pattern only rarely occurs in benign thyroid nodules, the results indicate that thyroid ultrasound can contribute to the diagnosis of MTC. In addition, the findings may have implications for calcitonin screening in nodular thyroid disease.
Exp Clin Endocrinol Diabetes 2002 Nov
PMID:Role of conventional ultrasound and color Doppler sonography in the diagnosis of medullary thyroid carcinoma. 1251 51

Premalignant conditions of the pancreas include benign tumours of the pancreas, intraepithelial neoplasia arising within pancreatic ducts, and tumours of the neuroendocrine cells of the pancreas. In addition, there is a variety of rare genetic conditions that predispose to pancreatic exocrine malignancies such as Peutz-Jeghers syndrome, hereditary non-polyposis colorectal cancer syndrome, familial pancreatitis, germline BRCA2 mutations, and pancreatic endocrine malignancies such as type 1 neurofibromatosis (von Recklinghausen's disease) and multiple endocrine neoplasia type 1. More controversial is the concept of chronic pancreatitis and diabetes mellitus as conditions that increase the risk of pancreatic cancer. However, there is no doubt that smoking is a potentiating factor for pancreatic cancer, especially in people who have familial/genetic risk factors. This review will include the recently proposed new nomenclature and classification system for intraepithelial neoplasia in the pancreatic ducts, an overview of the various familial syndromes that are associated with an increased risk of pancreatic tumours, the surveillance programmes that have been introduced to monitor such families, and methods for early diagnosis.
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PMID:Premalignant conditions of the pancreas. 1255 88

Hypermethylation of CpG island promoters is associated with transcriptional inactivation of tumor suppressor genes in neoplasia. Inactivation of p16 and Pten was related to the development of pheochromocytomas. In this report, we investigated the methylation status of the p16INK4a cell cycle inhibitor gene and other prominent tumor-related genes ( PTEN, RASSF1 A, CDH1, MSH2, MLH1, VHL, and TIMP3) in sporadic and multiple endocrine neoplasia type 2 (MEN2) pheochromocytomas by methylation-specific PCR. Hypermethylation was detected in 48 % of pheochromocytomas for RASSF1 A, 24 % for p16, 36 % for MSH2, 16 % for CDH1, and 8 % for PTEN. No VHL, MLH1, and TIMP3 methylation was observed. Interestingly, the frequency of p16 inactivation in familial tumors was higher (5 out of 12, 42 %) than in sporadic tumors (1 out of 13, 8 %; p = 0.047) and RASSF1 A inactivation was more common in the hereditary tumors (58 %) compared to the sporadic tumors (38 %). Combined methylation of RASSF1 A and p16 was found only in MEN2-related pheochromocytomas. Thus, a subset of hereditary pheochromocytomas displays preferential methylation of p16 and RASSF1 A.
Exp Clin Endocrinol Diabetes 2005 Jan
PMID:Frequent promoter methylation of tumor-related genes in sporadic and men2-associated pheochromocytomas. 1566 88

The goal of prophylactic surgery is to prevent malignant growth in patients with hereditary tumor predisposition. The pancreas presents as particularly challenging, due to the difficulty of operation and comparatively high risk of morbidity and even mortality. In addition, partial operative procedures and, more significantly, total resection lead to exocrine pancreas insufficiency and secondary diabetes, with grave consequences for the patient. Hereditary tumor predisposition syndromes that can result in pancreaticoduodenal endocrine tumors (PET) include multiple endocrine neoplasia type 1 syndrome and von Hippel-Lindau syndrome. As penetrance is maximally 70-80% and the 10-year survival rate over 80%, prophylactic pancreatic resection without evidence of a tumor is not indicated. However, prophylactic extension of a resection would be advised, should a PET be diagnosed. Patients predisposed to developing ductal pancreatic carcinoma (PC) are at risk of familial pancreatic cancer syndrome (FPC), hereditary pancreatitis, and other hereditary tumor predisposition syndromes such as Peutz-Jeghers syndrome and familial atypical multiple mole-melanoma syndrome. As the gene defect responsible for FPC has yet to be identified and the penetrance of PC in the other tumor predisposition syndromes is low or unknown, a prophylactic pancreatectomy based on today's knowledge is not indicated. Prophylactic extension of the resection is advisable should PC or high-grade PanIN lesions be diagnosed, as these patients often present with multifocal dysplasia and even carcinoma.
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PMID:[Prophylactic pancreas surgery]. 1630 89

Multiple endocrine neoplasia (MEN) embodies a group of diseases in human patients and domestic animals that are characterized by hyperplasia or neoplasia, or both, of two or more endocrine tissues. The MEN-1 syndrome is associated with menin gene mutations that induce various combinations of parathyroid, pituitary, and pancreatic endocrine tumors in humans. Two male, Domestic Shorthair cats developed symmetric alopecia, insulin-resistant diabetes mellitus, and pituitary-dependent hyperadrenocorticism at 12 and 13 years of age. Examination of skin biopsy specimens revealed atrophic dermatosis associated with hyperadrenocorticism. In one cat, cutaneous lesions consistent with paraneoplastic alopecia associated with pancreatic adenocarcinoma also were evident. Multiple invasive pancreatic beta cell carcinomas, pituitary corticotroph adenomas, and thyroid C-cell and parathyroid chief cell hyperplasia were diagnosed on the basis of results of gross, histologic, and immunohistochemical findings in both cats. Pancreatic exocrine adenocarcinoma was diagnosed in both cats. One cat also had hepatocellular carcinoma. Exons 1-8 of the feline menin gene were sequenced and were found to bear 93% homology with the human gene sequence, and the corresponding amino acid sequences shared 98% homology. Purification of total RNA and amplification of cDNA from lesional tissues to document mutations in the feline menin gene sequence were unsuccessful. The combination of lesions observed was consistent with the diagnosis of MEN-1-like syndrome in both cats.
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PMID:Multiple endocrine neoplasia type-I-like syndrome in two cats. 1667 81

Pheochromocytoma may infrequently lead to dilated cardiomyopathy, which may reverse partially or completely after treatment. Progressive dyspnea, palpitations, and paroxysmal attacks of severe hypertension leading to cardiac failure had developed in a 25-yr-old woman. Chest radiography and echocardiography revealed a massive 4-chamber dilatation of the heart with an ejection fraction of 12%. Twenty-four-h urinary vanillylmandelic acid and metanephrine levels were elevated. Magnetic resonance imaging detected a large mass lesion in the right adrenal gland. Oral glucose tolerance testing revealed diabetes mellitus. Medical drug therapy with alpha-blocker, angiotensin converting enzyme inhibitor, beta-blocker, digoxin, and diuretic rapidly improved her cardiac condition. Repeat echocardiogram showed that the left ventricular function had improved substantially. The clinical condition of excess catecholaminemia (and thus, arterial hypertension and the abnormality of the glucose metabolism) subsided with complete resolution of the congestive heart failure following the surgical removal of the tumor. Evaluation for medullary thyroid carcinoma (MTC) revealed an elevated calcitonin level demonstrated by fine needle aspiration biopsy. There were no biochemical evidences for primary hyperparathyroidism. Multiple endocrine neoplasia 2 (MEN 2A) syndrome was diagnosed. An overwhelming secretion of catecholamine might cause severe cardiomyopathy and impair glucose metabolism, as evidenced by the improvement of both conditions following the medical treatment of catecholaminemia and surgical resection of the tumor.
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PMID:Severe reversible dilated cardiomyopathy in a patient with multiple endocrine neoplasia 2A syndrome. 1669 5

Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.
Exp Clin Endocrinol Diabetes 2006 Apr
PMID:Double germline mutations in the RET Proto-oncogene in MEN 2A and MEN 2B kindreds. 1670 52


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