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Biomedical subjects

B Skogseid

Publications and source records attributed to B Skogseid.

At least 37 records · Page 2Linked to original sources
PubMed1999

Treatment with high dose [(111)In-DTPA-D-PHE1]-octreotide in patients with neuroendocrine tumors--evaluation of therapeutic and toxic effects.

Carcinoid tumors and endocrine pancreatic tumors often express somatostatin receptors (sst). Tumor spread may be visualized by sst scintigraphy using [(111)In-DTPA-D-Phe1]-octreotide. In this study, tumor targeting therapy with [(111)In-DTPA-D-Phe1]-octreotide at high doses (6 GBq every third week) was used to treat patients with sst-expressing tumors. Five patients entered the protocol and three were evaluable for response, while all could be evaluated for toxicity. Two patient responded with a significant reduction in tumor markers (> 50%). The third patient showed increasing levels of tumor markers. Side effects were expressed as depression of bone-marrow function. In one patient a grade 4 reduction in platelet count was observed requiring several thrombocyte transfusions. In another two patients platelet counts decreased significantly. We conclude that treatment with [(111)In-DTPA-D-Phe1]-octreotide can be used in patients with neuroendocrine tumors but blood parameters have to be carefully monitored to avoid severe side effects.

Aged↗
PubMed1999

Plasma chromogranin A in patients with multiple endocrine neoplasia type 1.

Plasma chromogranin A (CgA) has been claimed to be a sensitive marker for neuroendocrine tumors, but its role in the early diagnosis of multiple endocrine neoplasia type 1 (MEN 1) pancreatic endocrine tumors has not been evaluated. We measured CgA in 36 patients with MEN 1, of whom 9 lacked pancreatic involvement, 20 had biochemical evidence of pancreatic endocrine tumors, and 7 displayed radiologically detectable pancreatic tumors. CgA was also analyzed in 25 patients with sporadic pancreatic endocrine tumors, 39 subjects with inflammatory bowel disease, 7 patients harboring nonendocrine pancreatic disease, and 19 healthy controls. Four of 9 of the MEN 1 patients without pancreatic involvement had elevated CgA. Furthermore, 60% with biochemically unequivocal tumors and all with a radiologically visible tumor showed elevations. All 25 patients with sporadic pancreatic endocrine tumor had increased CgA, as had 28% of patients with inflammatory bowel disease and 57% with nonendocrine pancreatic disease. Mean day to day CgA variation was 29% (range, 0-113%) in the neuroendocrine tumor patients and 21.0% (range, 0.0-47%, within reference range) among healthy controls. In summary, nonendocrine diseases may cause elevation of CgA, and its spontaneous variation can be considerable. Plasma chromogranin A is the most sensitive of the basal markers for neuroendocrine tumors, but cannot replace other established measures when screening for early pancreatic involvement in MEN 1.

Adult↗
PubMed1999

Genetic alterations on 3p, 11q13, and 18q in nonfamilial and MEN 1-associated pancreatic endocrine tumors.

Pancreatic endocrine tumors occur sporadically and as part of the multiple endocrine neoplasia type 1 (MEN 1) and von Hippel-Lindau (VHL) syndromes. The MEN1 locus on 11q13 and a candidate tumor suppressor locus on 3p are known to be hemi- or homozygously mutated in a subset of these tumors. Chromosome arm 18q harbors the SMAD4/DPC4 tumor suppressor gene that is frequently deleted and inactivated in tumors of the exocrine pancreas. We have analyzed 22 nonfamilial and 16 MEN 1-associated pancreatic endocrine tumors for loss of heterozygosity (LOH) at 3p, 11q13, and 18q. LOH at 3p was revealed in 45% and 36% of tumors from 31 patients with nonfamilial and MEN 1-associated disease, respectively. The corresponding proportions for 11q13 were 55% and 91%, and for 18q 27% and 25%, respectively. A striking relation between LOH at 11q13 and 3p and a malignant phenotype was found for the nonfamilial tumors. None of the six benign tumors (all of them insulinomas) had allelic loss at 3p or 11q13, whereas 92% (P < 0.01) of the malignant tumors (including malignant insulinomas) had such deletions. Besides the 11q13 abnormality, more than half of the MEN 1-associated tumors had additional genetic lesions affecting 3p or 18q. LOH analysis of several tumors from two MEN 1 patients suggested different clonal origin of the lesions. Sequencing of the SMAD4/DPC4 gene did not identify mutations in coding regions or at exon/intron boundaries in tumors with LOH at 18q. The data indicate involvement of tumor suppressor genes on 3p and 18q, in addition to the MEN1 gene at 11q13, in the tumorigenesis of both nonfamilial and MEN 1-associated pancreatic endocrine tumors.

Biomarkers, Tumor↗
PubMed1999

Multiple endocrine neoplasia type 1: clinical and genetic features.

Multiple endocrine neoplasia type 1 has intrigued clinicians since its description because of its rarity and complex presentation of tumours in disparate endocrine organs. Its unpredictable course has made the development of strategies for clinical management difficult. The frequently indolent course in some family members, punctuated by lethal, aggressively malignant disease in others, has been frustrating as we strive to develop low-morbidity schemes for the prevention of the lethal manifestations of the syndrome. The recent description of the genetic abnormality responsible for the disease in many, if not all, families, will be of great assistance, even if it only allows the cessation of diagnostic testing for kindred members who are found to not carry the genetic abnormality. In fact, there is great promise in this discovery, as it may shed light on significant aspects of neuroendocrine oncogenesis. In spite of this, the clinical management strategies for these families will require further focused attention, in order to develop rational, prospective studies to answer the many questions that remain.

Adolescent↗
PubMed1999

Positron emission tomography in neuroendocrine tumours.

Positron emission tomography is an in vivo tracer and imaging technique that utilizes short-lived positron emitting radionuclides (11C, 15O, 13N, 18F) with half-lives ranging between 2 min and 2 hours. These radionuclides are interesting from the labelling viewpoint since they are natural constituents of most biologically active compounds. The short half-life is an advantage with regard to the irradiation dose to the patient but it is also a limitation since it requires the production of these radionuclides in close vicinity to the positron emission tomography camera.

Female↗
PubMed1998

Targeted disruption of the mouse phospholipase C beta3 gene results in early embryonic lethality.

In order to investigate the biological function of phosphatidylinositol-specific phospholipase C (PLC) we generated mutant mice by gene targeting. Homozygous inactivation of PLCbeta3 is lethal at embryonic day 2.5. These mutants show poor embryonic organization as well as reduced numbers of cells. Identical phenotypes were recorded in homozygous mutants generated from two independently targeted embryonic stem cell clones. Heterozygous mutant mice, however, are viable and fertile for at least two generations. We also showed that mouse PLCbeta3 is expressed in unfertilized eggs, 3-cell and egg cylinder stages of embryos. In conclusion, these results indicate that PLCbeta3 expression is essential for early mouse embryonic development.

Animals↗
PubMed1998

Molecular cloning and characterization of a cDNA encoding mouse phospholipase C-beta3.

A cDNA encoding mouse PLC-beta3 (mPLC-beta3) was identified by screening a mouse kidney cDNA library and using the rapid amplification of cDNA ends (RACE) method. The predicted open reading frame was 3705 bp in length. The deduced 1235 amino acid (aa) sequence shares 95.3% and 92% homology with the sequences of rat and human PLC-beta3, respectively. The corresponding mRNA is highly expressed in kidney, skeletal muscle, liver, lung, heart and brain. In spleen, mPLC-beta3 mRNA was not detectable, which is in contrast to humans where there is a distinct expression. Using ultrastructural immunocytochemistry, mPLC-beta3 expression was detected in the heterochromatin of the nucleus in mouse brain neurons. The observation of PLC-beta3 nuclear localization suggests that PLC-beta3 may have intranuclear functions.

Amino Acid Sequence↗
PubMed1998

Mutation of the multiple endocrine neoplasia type 1 gene in nonfamilial, malignant tumors of the endocrine pancreas.

Endocrine pancreatic tumors are rare neoplasms that occur sporadically or as part of a multiple endocrine neoplasia type 1 (MEN1) syndrome. Germ-line mutations of the MEN1 gene, located at 11q13, have been demonstrated in MEN1 kindreds, and loss of heterozygosity (LOH) on 11q13 together with somatic MEN1 mutations have been detected in 20% of nonfamilial parathyroid tumors. Here, we examine 11 non-MEN1 malignant tumors of the endocrine pancreas, 9 nonfunctioning tumors, and 2 glucagonomas. LOH of at least one informative locus on 11q13 was found in 70% of the tumors. Three tumors displayed somatic mutations of the MEN1 gene together with LOH on 11q13, whereas the corresponding germ-line DNA was normal. These findings support the hypothesis that MEN1 gene mutations contribute to the tumorigenesis of nonfamilial, malignant endocrine pancreatic tumors.

Adult↗
PubMed1998

Preoperative diagnosis and surgical management of neuroendocrine gastroenteropancreatic tumors: general recommendations by a consensus workshop.

In 1996 a consensus workshop on the preoperative diagnosis and surgical treatment of neuroendocrine tumor disease took place in Berlin. Although there was a consensus on the diagnosis and surgical treatment by world experts in neuroendocrine surgery in some areas, it became clear that certain management policies vary among centers. In large part, diverging policies reflect a lack of controlled studies. This paper summarizes the various opinions brought forward during this conference and emphasizes consensus approaches for the diagnosis and therapy of neuroendocrine neoplasms.

Gastrointestinal Neoplasms↗
PubMed1998

Limited tumor involvement found at multiple endocrine neoplasia type I pancreatic exploration: can it be predicted by preoperative tumor localization?

Radiologically demonstrable pancreatic endocrine tumors are a frequent requirement for exploration in patients with multiple endocrine neoplasia type I (MEN-I). Such delayed intervention is accompanied by a 30% to 50% incidence of pancreatic endocrine metastases. This study explores biochemical tumor markers and operative findings in relation to preoperative pancreatic radiology in 25 MEN-I patients. They underwent pancreatic surgery with (n = 19) or without (n = 6) radiologic signs of primary tumor and absence of metastases upon conventional examination, including OctreoScan testing (n = 10). Biochemical diagnosis required an increasing elevation of at least two independent pancreatic tumor markers. Tumor diameters averaged 1.1 cm (0-5 cm) and 0.9 cm (0.2-1.5 cm) in the patients with and without positive preoperative radiology, respectively. These investigations never displayed more than one of the consistently multiple tumors, and the results were falsely positive in 26%. Preoperatively unidentified regional or hepatic metastases were found at surgical exploration in 26% of patients with radiologic localization and in none of the others. Limited pancreatic tumor involvement necessitated intraoperative absence of metastases and pancreatic lesions </= 1 cm in diameter on palpation, intraoperative ultrasonography, and microscopy. It occurred in 37% and 50% of the patients with and without radiologic tumor localization, respectively. The number of positive tumor markers was similar for patients with limited and major disease (2.3 vs. 2.7), whereas four or more such markers were found in all those with malignancies. The mean marker level was higher in patients with radiologically demonstrable tumors and lower in those with limited disease, but with a substantial overlap. OctreoScan testing was negative in all cases with limited disease and was the single most sensitive method (75%) in the others. Limited pancreatic disease could not be identified preoperatively, and the present means of biochemical pancreatic tumor identification invariably involved the presence of at least one lesion >/= 7 mm in diameter. Conventional pancreatic imaging is insensitive and nonspecific for recognizing even substantial pancreatic tumors associated with MEN-I.

Adult↗
PubMed1998

The ultimate biochemical diagnosis of endocrine pancreatic tumours in MEN-1.

Multiple endocrine neoplasia type 1 (MEN-1) is a well characterized hereditary syndrome with the occurrence of primary hyperparathyroidism (HPT) in combination with pancreatic-duodenal endocrine and anterior pituitary tumours. The diagnosis of MEN-1, the possible probands, necessitates the recognition of at least two or three lesions classically associated with the syndrome whilst only one of them is required for individuals belonging to established MEN-1 kindreds. A distinct feature of MEN-1 comprises the multiplicity of organ involvement, the multicentricity of tumours within the affected organs as well as the complex pattern of the clinical signs of these tumours and their sometimes temporarily variable profile of hormone excess. Thorough screening studies have demonstrated that the MEN-1 trait is biochemically detectable virtually two decades prior to clinically overt disease. The primary biochemical screening programme for MEN-1 includes serum prolactin and insulin growth factor 1 (IGF-1) for pituitary lesions, intact PTH and albumin corrected total serum calcium for the parathyroids and for duodenal/pancreatic tumours serum glucose, insulin, proinsulin, pancreatic polypeptide, glucagon, gastrin and plasma chromogranin A. Furthermore a standardized meal stimulatory test analysing serum polypeptides (PP) and gastrin is recommended. Our current primary screening procedure has yielded about 10% false positives when compared with RFLP data. Pancreatic endocrine tumour diagnosis must be biochemically established since radiology fails to show lesions in half of the patients. Pancreatic involvement in young MEN-1 patients is most consistently demonstrated by analysing serum insulin, proinsulin, PP as well as plasma glucagon chromogranin A levels, which have exhibited sensitivities of 56, 67, 37 and 60%, respectively. Serum PP is a non-specific marker of islet cell tumours that should be applied in conjunction with other peptide markers. Elevation of basal serum gastrin generally indicates the presence of advanced pancreatic tumour involvement or duodenal carcinoids. Early diagnosis of pancreatic endocrine tumours in MEN-1 is enhanced by the use of a standardized meal stimulation test with measurements of serum PP and gastrin response. This test was the most sensitive test and substantiated the presence of tumour in 75% of individuals whose mean age was 25 years. False-positive stimulation due to the meal test has been found in about 10% of previous investigated individuals. The diagnosis of MEN-1 pancreatic tumours is based on biochemical screening alone and it has been substantiated that an unequivocal rise in pancreatic tumour markers precedes radiological detection of these lesions by at least five years.

Biomarkers, Tumor↗
PubMed1998

Thymic carcinoids in multiple endocrine neoplasia type 1.

OBJECTIVE: To study the clinical, pathologic, and genetic features of thymic carcinoids in the setting of multiple endocrine neoplasia type 1 (MEN1) and to study means for detection and prevention of this tumor in patients with MEN1. SUMMARY BACKGROUND DATA: Thymic carcinoid is a rare malignancy, with approximately 150 cases reported to date. It may be associated with MEN1 and carries a poor prognosis, with no effective treatment. Its underlying etiology is unknown. METHODS: Ten patients with MEN1 from eight families with anterior mediastinal tumors were included in a case series study at tertiary referring hospitals. Clinicopathologic studies were done on these patients, with a review of the literature. Mutation analysis was performed on the MEN1 gene in families with clusterings of the tumor to look for genotype-phenotype correlation. Loss of heterozygosity was studied in seven cases to look for genetic abnormalities. RESULTS: Histologic studies of all tumors were consistent with the diagnosis of thymic carcinoid. Clustering of this tumor was found in some of the families-three pairs of brothers and three families with first- or second-degree relatives who had thymic carcinoid. All patients described here were men, with a mean age at detection of 44 years (range 31 to 66). Most of the patients had chest pain or were asymptomatic; none had Cushing's or carcinoid syndrome. All tumors were detected by computed tomography (CT) or magnetic resonance imaging (MRI) of the chest. The results of octreoscans performed in three patients were all positive. Histopathologic studies were consistent with the diagnosis of thymic carcinoid and did not stain for ACTH. Mutation analysis of the families with clustering revealed mutations in different exons/introns of the MEN1 gene. Loss of heterozygosity (LOH) studies of seven tumors did not show LOH in the MEN1 region, but two tumors showed LOH in the 1p region. CONCLUSIONS: MEN1-related thymic carcinoids constitute approximately 25% of all cases of thymic carcinoids. In patients with MEN1, this is an insidious tumor not associated with Cushing's or carcinoid syndrome. Local invasion, recurrence, and distant metastasis are common, with no known effective treatment. We propose that CT or MRI of the chest, as well as octreoscanning, should be considered as part of clinical screening in patients with MEN1. We also propose performing prophylactic thymectomy during subtotal or total parathyroidectomy on patients with MEN1 to reduce the risks of thymic carcinoid and recurrence of hyperparathyroidism. Its male predominance, the absence of LOH in the MEN1 region, clustering in close relatives, and the presence of different MEN1 mutations in these families suggest the involvement of modifying genes in addition to the MEN1 gene. A putative tumor suppressor gene in 1p may be involved.

Adult↗
PubMed1998

Clinical symptoms, hormone profiles, treatment, and prognosis in patients with gastric carcinoids.

BACKGROUND: Type 1 gastric carcinoids are associated with hypergastrinaemia and chronic atrophic gastritis, type 2 occur in patients with multiple endocrine neoplasia type 1 combined with Zollinger-Ellison syndrome, and type 3 lack any relation to hypergastrinaemia. Type 1 tumours are usually benign whereas type 3 are highly malignant. AIMS: To identify possible tumour markers in patients with gastric carcinoids. PATIENTS/METHOD: Nine patients with type 1, one with type 2, and five with type 3 were evaluated with regard to symptoms, hormone profile, and prognosis. RESULTS: Plasma chromogranin A was increased in all patients but was higher (p < 0.01) in those with type 3 than those with type 1 carcinoids. All patients with type 3 carcinoids died from metastatic disease, but none of the type 1 patients died as a result of their tumours. One type 1 patient with a solitary liver metastasis received interferon alpha and octreotide treatment. Nine months later, the metastasis was no longer detectable. She is still alive eight years after diagnosis, without recurrent disease. This represents the only reported case of foregut carcinoid with an unresectable liver metastasis that seems to be have been cured by biotherapy. CONCLUSIONS: Plasma chromogranin A appears to be a valuable tumour marker for all types of gastric carcinoid. Combination therapy with interferon alpha and octreotide may be beneficial in patients with metastasising type 1 gastric carcinoids.

Adult↗
PubMed1998

Parathyroid MEN1 gene mutations in relation to clinical characteristics of nonfamilial primary hyperparathyroidism.

Biochemical signs and severity of symptoms of primary hyperparathyroidism (pHPT) differ among patients, and little is known of any coupling of clinical characteristics of nonfamilial pHPT to genetic abnormalities in the parathyroid tumors. Mutations in the recently identified MEN1 gene at chromosome 11q13 have been found in parathyroid tumors of nonfamilial pHPT. Using microsatellite analysis for loss of heterozygosity (LOH) at 11q13 and DNA sequencing of coding exons, the MEN1 gene was studied in 49 parathyroid lesions of patients with divergent symptoms, operative findings, histopathological diagnosis, and biochemical signs of nonfamilial pHPT. Allelic loss at 11q13 was detected in 13 tumors, and 6 of them demonstrated previously unrecognized somatic missense and frameshift deletion mutations of the MEN1 gene. Many of the detected mutations would most likely result in a nonfunctional menin protein, consistent with a tumor suppressor mechanism. Clinical and biochemical characteristics of HPT were apparently unrelated to the presence or absence of LOH and the MEN1 gene mutations. However, the demonstration of LOH at 11q13 and MEN1 gene mutations in small parathyroid adenomas of patients with slight hypercalcemia and normal serum PTH levels suggest that altered MEN1 gene function may also be important for the development of mild sporadic pHPT.

Adenoma↗
PubMed1998

Mutation analysis of the MEN1 gene in multiple endocrine neoplasia type 1, familial acromegaly and familial isolated hyperparathyroidism.

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disease characterized by neoplasia of the parathyroid glands, the endocrine pancreas, and the anterior pituitary gland. In addition, families with isolated endocrine neoplasia, notably familial isolated hyperparathyroidism (FIHP) and familial acromegaly, have also been reported. However, whether these families constitute MEN 1 variants or separate entities remains speculative as the genetic bases for these diseases are unclear. The gene for MEN 1 has recently been cloned and characterized. Using single strand conformation analysis (SSCA) and sequencing, we performed mutation analysis in: a) a total of 55 MEN 1 families from 7 countries, b) 13 isolated MEN 1 cases without family history of the disease, c) 8 acromegaly families, and d) 4 FIHP families. Mutations were identified in 27 MEN 1 families and 9 isolated cases. The 22 different mutations spread across most of the 9 translated exons and included frameshift (11), nonsense (6), splice (2), missense mutations (2), and in-frame deletions (1). Among the 19 Finnish MEN 1 probands, a 1466del12 mutation was identified in 6 families with identical 11q13 haplotypes and in 2 isolated cases indicating a common founder. One frameshift mutation caused by 359del4 (GTCT) was found in 1 isolated case and 4 kindreds of different origin and haplotypes; this mutation therefore represents a common "warm" spot in the MEN1 gene. By analyzing the DNA of the parents of an isolated case one mutation was confirmed to be de novo. No mutation was found in any of the acromegaly and small FIHP families, suggesting that genetic defects other than the MEN1 gene might be involved and that additional such families need to be analyzed.

Acromegaly↗
PubMed1998

Primary and reoperative parathyroid operations in hyperparathyroidism of multiple endocrine neoplasia type 1.

BACKGROUND: Operation and reoperation for hyperparathyroidism in multiple endocrine neoplasia type 1 (MEN 1) is controversial regarding surgical strategy, preoperative localization, and biochemical indexes of recurrence. METHODS: Fifty patients with MEN 1 with hyperparathyroidism were followed up 2 to 27 years after subtotal (SPX; n = 35) or total parathyroidectomy with forearm autografiing (TPX; n = 15), including 24 who underwent 28 reoperations because of persistent or recurrent hyperparathyroidism. RESULTS: Persistent or recurrent hyperparathyroidism was seen in 66% and 20% of patients after SPX involving extirpation of at least 3 glands and TPX, respectively, and 100% after single-gland excision as a primary procedure. After reoperation, hypercalcemia was reversed in 33% of patients by SPX and 61% by intended TPX procedures. All patients received vitamin D substitution after TPX, but restricted thyroid function allowed withdrawal in all but 10 patients (36%). Intact serum parathyroid hormone levels in nongrafted and grafted arms rose with time, but only exceptional ratios localized graft recurrence. Localization of recurrent hyperparathyroidism was achieved with 11C-labeled methionine positron emission tomography. CONCLUSION: MEN 1 hyperparathyroidism has a high risk of recurrence, and operation may include primarily SPX of at least 3 glands or TPX, although the latter includes a higher risk of long-term hypoparathyroidism. Reoperation should involve TPX with recognition of the enhanced recurrence rate in individuals with postoperative hyperparathyroidism.

Adolescent↗
PubMed1996

Definition of the minimal MEN1 candidate area based on a 5-Mb integrated map of proximal 11q13. The European Consortium on Men1, (GENEM 1; Groupe d'Etude des Néoplasies Endocriniennes Multiples de type 1).

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with a high penetrance characterized by tumors of the parathyroid glands, the endocrine pancreas, and the anterior pituitary. The MEN1 gene, a putative tumor suppressor gene, has been mapped to a 3- to 8-cM region in chromosome 11q13 but it remains elusive as yet. We have combined the efforts and resources from four laboratories to form the European Consortium on MEN1 with the aims of establishing the genetic and the physical maps of 11q13 and of further narrowing the MEN1 region. A 5-Mb integrated map of the region was established by fluorescence in situ hybridization on both metaphase chromosomes and DNA fibers, by hybridization to DNA from somatic cell hybrids containing various parts of human chromosome 11, by long-range restriction mapping, and by characterization of YACs and cosmids. Polymorphic markers were positioned and ordered by physical mapping and genetic linkage in 86 MEN1 families with 452 affected individuals. Two critical recombinants identified in two affected cases placed the MEN1 gene in an approximately 2-Mb region around PYGM, flanked by D11S1883 and D11S449.

Animals↗