Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “NEUROFIBROMATOSIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,801 records · Page 100Linked to original sources
PubMed2001

Structural basis for neurofibromatosis type 2. Crystal structure of the merlin FERM domain.

Neurofibromatosis type 2 (NF2) is a dominantly inherited disease associated with the central nervous system. The NF2 gene product merlin is a tumor suppressor, and its mutation or inactivation causes this disease. We report here the crystal structure of the merlin FERM domain containing a 22-residue alpha-helical segment. The structure reveals that the merlin FERM domain consists of three subdomains displaying notable features of the electrostatic surface potentials, although the overall surface potentials similar to those of ezrin/radixin/moesin (ERM) proteins indicate electrostatic membrane association. The structure also is consistent with inactivation mechanisms caused by the pathogenic mutations associated with NF2.

Amino Acid Sequence↗
PubMed2005

The neurofibromatosis type 1 gene product neurofibromin enhances cell motility by regulating actin filament dynamics via the Rho-ROCK-LIMK2-cofilin pathway.

Neurofibromin is a neurofibromatosis type 1 (NF1) tumor suppressor gene product with a domain that acts as a GTPase-activating protein and functions, in part, as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation, predisposing to a variety of tumors of the peripheral and central nervous systems. We show here, using the small interfering RNA (siRNA) technique, that neurofibromin dynamically regulates actin cytoskeletal reorganization, followed by enhanced cell motility and gross cell aggregation in Matrigel matrix. NF1 siRNA induces characteristic morphological changes, such as excessive actin stress fiber formation, with elevated negative phosphorylation levels of cofilin, which regulates actin cytoskeletal reorganization by depolymerizing and severing actin filaments. We found that the elevated phosphorylation of cofilin in neurofibromin-depleted cells is promoted by activation of a Rho-ROCK-LIMK2 pathway, which requires Ras activation but is not transduced through three major Ras-mediated downstream pathways via Raf, phosphatidylinositol 3-kinase, and RalGEF. In addition, the exogenous expression of the NF1-GTPase-activating protein-related domain suppressed the NF1 siRNA-induced phenotypes. Neurofibromin was demonstrated to play a significant role in the machinery regulating cell proliferation and in actin cytoskeletal reorganization, which affects cell motility and adhesion. These findings may explain, in part, the mechanism of multiple neurofibroma formation in NF1 patients.

Actin Depolymerizing Factors↗
PubMed2000

The association of neurofibromatosis type 1 and attention deficit hyperactivity disorder.

Some research and clinical observations have linked Neurofibromatosis Type 1 (NF-1) and Attention Deficit Hyperactivity Disorder (ADHD). In order to investigate whether ADHD is part of the phenotype of NF-1 or is a separate, unrelated disorder within families, we compared the ADHD status of children affected with NF-1 to that of their unaffected-NF-1 siblings and to that of their biological parents. Results of matched-pair analyses were calculated and revealed a significant with-in pair discordance, when comparing children with NF-1 and their siblings and when comparing children with NF-1 and their biological parents (in families with a sporadic, non-familial NF-1 child). These findings suggest that ADHD may occur as a component of the NF-1 phenotype.

Adolescent↗
PubMed2004

Neurofibromatosis type 1 associated with central nervous system lymphoma.

PURPOSE: To report the occurrence of central nervous system (CNS) lymphoma in a patients with neurofibromatosis type 1 (NF1). DESIGN: Interventional case report. METHODS: A 47-year-old male with a parieto-occipital lobe lesion was referred for ocular evaluation. Skin, brain, and vitreous biopsies were performed. RESULTS: The discovery of Lisch nodules of the iris prompted a physical examination that revealed cutaneous stigmata of NF1. Biopsy of the CNS lesion revealed diffuse large B-cell lymphoma. Biopsy of papules on the back and abdomen were compatible with neurofibroma. No malignant cells were found in the vitreous specimen. A clinical diagnosis of NF1 was made. CONCLUSION: This is the first report of CNS lymphoma in a patient with NF1. Additional reports may shed more light on the possible association between the two conditions.

Antineoplastic Agents↗
PubMed1999

Heterotopic pancreas, periampullary somatostatinoma and type I neurofibromatosis: a pathogenetic proposal.

This case documents the association of ectopic pancreatic tissue with a duodenal somatostatinoma in a patient with type I neurofibromatosis. Pancreatic ducts have been noted within the centres of somatostatinomas, but little significance has been attached to this finding. Here we describe a patient in whom a separate proliferation of somatostatin cells occurred in association with the ectopic pancreatic ductular epithelium. This lesion bore a striking resemblance to the ductulo-insular or ductulo-endocrine complexes that are seen in nesidioblastosis in the pancreas. We therefore postulate that the ducts, which are sequestered within somatostatinomas, are of pathogenetic significance. The somatostatin-producing cells arise from these ducts, very much in the fashion of ductulo-endocrine complexes in nesidioblastosis.

Adult↗
PubMed2006

Use of 2-tracer PET to diagnose gastrointestinal stromal tumour and pheochromocytoma in patients with Carney triad and neurofibromatosis type 1.

There is rapid evolution in the functional imaging of tumours. In two patients with concomitant pheochromocytoma and gastrointestinal stromal tumour (GIST), previously unrecognized tumours were visualized by combined 2-tracer positron emission tomography (PET), which also provided precise information about tumour type. PET imaging led to radical resection and the diagnoses were histopathologically confirmed. GISTs from the Carney patient and the patient with neurofibromatosis type 1 (NF1) both lacked KIT mutations.

Adrenal Gland Neoplasms↗
PubMed1999

Simultaneous involvement of the jejunum and the colon by type-1 neurofibromatosis.

Type-1 neurofibromatosis (NF-1) or Von Recklinghausen disease is an autosomal dominant hereditary condition that may affect the gastrointestinal tract in 25% of cases and which takes three main forms: ganglioneuromatosis, stromal tumors, and tumors in the duodenum and periampullar region. Not infrequently, these patients present with gastrointestinal bleeding. We present the case of a 48-year-old patient diagnosed as having NF-1, with relapsing episodes of gastrointestinal hemorrhage, in which we discovered the simultaneous presence of a stromal tumor in the jejunum together with polypoid and diffuse ganglioneuromatosis in the colon.

Colon↗
PubMed1987

Neurofibromatosis in Nigerian children.

A study of 14 children with multiple neurofibromatosis (Von Recklinghausen's disease) seen at the Lagos University Teaching Hospital within a 6-year period (1979-85) has been carried out. Eight were boys while six were girls. The youngest was 3 months old. The café-au-lait spots observed in all these children showed poor colour contrast, thus making it not easily discernible in infancy and early diagnosis difficult. They are therefore better called "café-sans-lait" or "blackish brown" spots in the African. Hyperpigmented patches were observed in eight children and multiple grotesque soft tissue swellings in ten others. Prolonged follow-up is mandatory in these patients in order to give them a better quality of life.

Adolescent↗
PubMed2004

Spontaneous involution of a non-optic astrocytoma in neurofibromatosis type I: serial magnetic resonance imaging evaluation.

A patient with neurofibromatosis type I (NF1) was followed-up with serial magnetic resonance imaging (MRI) studies over a period of 6 years. A contrast-enhancing lesion of the internal capsule, histologically proven to be pilocytic astrocytoma through stereotactic brain biopsy with mass effect and associated edema, was detected to reveal spontaneous involution on follow-up MRI studies. Although spontaneous regression of gliomas of the optic pathway-hypothalamus in patients with NF1 is relatively common in the literature, spontaneous involution of non-optic (i.e. areas other than optic pathways and hypothalamus) gliomas is rarely reported. Conservative management with follow-up MRI studies should be considered for non-optic glial tumors and tumor-like masses in patients with NF1, and surgical treatment should not be considered unless the lesions exhibit a rapid or unrelenting growth on serial MRI studies or produce significant clinical deterioration.

Astrocytoma↗
PubMed2005

Lhermitte-Duclos disease associated with neurofibromatosis type-1 and non-ossifying fibroma.

Lhermitte-Duclos disease (LDD) is a rare cerebellar disorder of uncertain pathogenesis characterized by enlargement of cerebellar folia. Magnetic resonance imaging is the diagnostic modality of choice and usually distinguishes the LDD by its characteristic "striated or laminated pattern" appearance. Various additional abnormalities have been reported in association with LDD. We report a case of LDD coexisting with neurofibromatosis type 1 (NF-1) and non-ossifying fibroma.

Bone Neoplasms↗
PubMed2003

Extensor digitorum brevis manus muscle in a patient with neurofibromatosis type 1.

The extensor digitorum brevis manus is an uncommon muscle on the dorsum of the hand and can be misdiagnosed, particularly when associated with other clinical conditions such as neurofibromatosis type 1. To our knowledge the two clinical pictures have never been described together. The aim of our report is to increase the clinician's familiarity with these combined conditions, to investigate the available diagnostic tools, and to achieve a correct diagnosis.

Adult↗
PubMedDate not supplied

Neurofibromatosis 1 associated with embryonal rhabdomyosarcoma of the urinary bladder.

A 10-month-old boy presented with a 6-week history of abdominal pain. The pain was due to a large, stage IV embryonal rhabdomyosarcoma of the urinary bladder. The rhabdomyosarcoma was found in association with neurofibromatosis 1 (NF1) manifesting multiple café au lait spots and bowing of the right calf. The diagnosis of NF1 had not been made before presentation. This case report is intended to heighten the awareness of the manifestations of NF1 and the possibility of developing a nonneuroectodermal tumor as a concomitant of NF1, and to emphasize the importance of timely diagnosis and treatment of such an NF1-associated malignancy. Reports of the epidemiologic evidence for rhabdomyosarcoma in children with NF1 are reviewed.

Humans↗
PubMed2004

Neurofibromatosis type II presenting as vertical diplopia.

Neurofibromatosis type II (NF II) is rare and most commonly presents with hearing loss, tinnitus and/or vestibular disturbance in the third decade of life. The authors describe a rare case presenting with NF II with vertical diplopia due to IV(th) nerve palsy. The patient was otherwise asymptomatic despite multiple extensive lesions on MRI.

Adult↗
PubMed2006

Neurofibromatosis type I and smoldering multiple myeloma: a case report.

We present a case of a 64-year-old woman with neurofibromatosis (NF1) and smoldering multiple myeloma (SMM). SMM was diagnosed 9 years ago when the asymptomatic patient was found to have mild anemia, IgA paraproteinemia, hypogammaglobulinemia, osteopenia without any lytic bone lesions and bone marrow plasmacytosis. During follow-up period she remained stable in an excellent clinical condition without requiring any therapy for almost 4 years. Forty-two months after diagnosis she had a femoral fracture and since then biphosphonates have been administered intravenously, once monthly. Subsequent evaluations of the disease showed a dramatic reduction of IgA paraprotein to below half the initial value. We will discuss the probable pathogenesis of plasma cell dyscrasia in NF1 patients, as well as the likely antimyeloma activity of biphoshonates.

Bone Density Conservation Agents↗
PubMed2006

Parvovirus B-19 induced acute pure red cell aplasia in patients with chronic lymphocytic leukemia and neurofibromatosis type-1.

Parvovirus B19 induced pure red cell aplasia (PRCA) has been previously reported in a variety of settings. We present two cases, an adult patient with chronic lymphocytic leukemia (CLL) and a child with neurofibromatosis type-1 (NF-1), where the abrupt appearance of severe anemia raised ominous clinical suspicions. Evidence of recent parvovirus B19 infection in association with the selective erythroid precursor deficiency in marrow helped exclude other etiologies. We emphasize the importance of bearing this infectious agent in mind, even when there are associated disorders (such as CLL) that may independently cause PRCA. An association of NF-1 with acute PRCA has not been described in indexed English literature in the past.

Acute Disease↗
PubMed1991

[Type I neurofibromatosis (von Recklinghausen's disease) associated with abdominal neurofibrosarcoma and pheochromocytoma. Apropos of a case].

Neoplasia and endocrine disorders are common complications of neurofibromatosis 1 (NF1--von Recklinghausen disease). We report here a case of NF1 in a 31-year-old woman presenting simultaneously with an abdominal neurofibrosarcoma and a pheochromocytoma. The prevalence of secondary neoplasia and endocrine tumors in NF1 is also discussed.

Abdominal Neoplasms↗
PubMedDate not supplied

Retroperitoneal neurofibrosarcoma in a patient with neurofibromatosis. 2: A case report and review of the literature.

Neurofibromatosis (NF) type I (NF1) is the most common familial cancer-predisposing syndrome in humans, while type 2 (NF2) accounts for an extremely small percentage of the total cases of NF. Tumors occurring in patients with NF1 are primarily peripheral neurofibromas, while NF2 patients present with central schwannomas. Malignant transformation has been described in NF1 patients; however, in NF2 the risk of malignant transformation is extremely rare. In this case report, the authors document a retroperitoneal neurogenic sarcoma occurring in a 20-year-old woman with NF2 (bilateral acoustic schwannomas, meningioma, and multiple intraspinal tumors).

Adult↗
PubMed1996

Distinct cellular and subcellular patterns of expression imply distinct functions for the Drosophila homologues of moesin and the neurofibromatosis 2 tumor suppressor, merlin.

Interest in members of the protein 4.1 super-family, which includes the ezrin-radixin-moesin (ERM) group, has been stimulated recently by the discovery that the human neurofibromatosis 2 (NF2) tumor suppressor gene encodes an ERM-like protein, merlin. Although many proteins in this family are thought to act by linking the actin-based cytoskeleton to transmembrane proteins, the cellular functions of merlin have not been defined. To investigate the cellular and developmental functions of these proteins, we have identified and characterized Drosophila homologues of moesin (Dmoesin) and of the NF2 tumor suppressor merlin (Dmerlin). Using specific antibodies, we show that although these proteins are frequently coexpressed in developing tissues, they display distinct subcellular localizations. While Dmoesin is observed in continuous association with the plasma membrane, as is typical for an ERM family protein, Dmerlin is found in punctuate structures at the membrane and in the cytoplasm. Investigation of Dmerlin cultured cells demonstrates that it is associated with endocytic compartments. As a result of these studies, we propose that the merlin protein has unique functions in the cell which differ from those of other ERM family members.

Amino Acid Sequence↗

Refine your search to explore more results.