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 613 records · Page 34Linked to original sources
PubMed1986

Enhanced radiotolerance to ionizing radiation is correlated with increased cancer proneness of cultured fibroblasts from precursor states in neurofibromatosis patients.

We have determined the sensitivity to gamma rays of cultured fibroblasts derived from clinically defined areas on the skin of neurofibromatosis patients. Fibroblasts from skin of normal appearance were normally sensitive to gamma irradiation. Significantly, however, fibroblasts from café-au-lait lesions and from neurofibromas were abnormally radiotolerant (about twofold) to treatment with gamma rays. This was seen in specimens taken from the same patient, as well as from different patients, within four different neurofibromatosis pedigrees. In contrast, no differences in radiosensitivity have been observed between fibroblasts derived from skin of normal appearance and those obtained from melanotic freckles of individuals with no family history of cancer. The results suggest that increased propensity to cancer in this cell system is associated with increased radiotolerance to ionizing radiation.

Adult↗
PubMed1987

Neurofibromatosis in a man with a ring 22: in situ hybridization studies.

In situ hybridization with a c-sis probe was performed on peripheral lymphocytes of a man with neurofibromatosis and a ring 22 chromosome. Hybridization was observed on both the normal #22 and the ring 22, indicating that the patient is not constitutionally hemizygous for c-sis. The implications of a ring 22 constitution and the neurofibromatosis phenotype are discussed.

Adult↗
PubMed1990

Sarcomas in three generations of a family with neurofibromatosis.

The development of sarcomas in three generations of a family with neurofibromatosis (NF) is described. A 7-month-old boy developed a prostatic rhabdomyosarcoma. Family history revealed that his maternal grandmother had died of a malignant peripheral nerve sheath tumor at age 37 years and had been affected with neurofibromatosis. His mother (aged 36 years) has also developed a malignant peripheral nerve sheath tumor and NF has been confirmed in both mother and son. This family illustrates a cluster of sarcomas associated with NF and shows the importance of thorough investigation of reported family illnesses.

Adult↗
PubMed1993

Involvement of 22q12 in a neurofibrosarcoma in neurofibromatosis type 1.

We describe the cytogenetic and molecular genetic findings in a neurofibrosarcoma arising in a patient affected by neurofibromatosis type 1. Multiple chromosomal rearrangements were found but only a few of them were identified as clonal abnormalities, including a deletion of chromosome 22, which at the molecular level proved to be interstitial, mainly involving the 22q12 region. Loss of heterozygosity for markers D22S32 and MB was observed. These findings are in agreement with previous data which suggest a possible involvement of a gene located at 22q11-q13.1 during the neoplastic development of some neurofibromatosis type 1-associated tumors.

Adult↗
PubMed1982

Central neurofibromatosis.

Two patients with central form of neurofibromatosis are reported. Bilateral acoustic neuromas were diagnosed by computerized tomography (CT) scan in one and at autopsy in the other patient. The clinical and radiologic features in the first patient indicated associated bilateral optic nerve gliomas. The autopsied case in addition had multiple meningiomas and numerous nontumorous glial hamartomas. The clinical, pathologic and biochemical basis for classification of neurofibromatosis into central and peripheral forms are discussed.

Adolescent↗
PubMed1989

Anterolateral lumbar meningocele presenting as an ovarian cyst, in a patient with neurofibromatosis.

A case of an anterolateral lumbar meningocele in a patient with neurofibromatosis is presented. As anterolateral lumbar meningocele may present itself only by non-specific symptoms like low back pain or abdominal pain, such symptoms require prompt diagnostic work up in patients with neurofibromatosis. The significance of MR imaging in early recognition of this rare anomaly is emphasized.

Adult↗
PubMed1992

Nicotinamide-induced activity of alkaline phosphodiesterase I toward tumor-derived cultured cells from neurofibromatosis patients.

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.

Enzyme Induction↗
PubMed1995

MRI in neurofibromatosis type I: using fluid-attenuated inversion recovery pulse sequences.

Cranial magnetic resonance imaging results of 14 patients with neurofibromatosis type I were examined with T2-weighted fluid-attenuated inversion recovery pulse sequences, as well as conventional T2-weighted spin-echo sequences. Definition was better in 62 of 79 lesions or groups of lesions on fluid-attenuated inversion recovery images than on T2-weighted spin-echo images. The lesions were demonstrated not only in the brainstem, cerebellum, globus pallidus, and cerebral white matter, but also in the hippocampus, pulvinar thalami, and splenium of the corpus callosum. The latter 3 lesions have not been demonstrated or emphasized in previous studies. It is concluded that fluid-attenuated inversion recovery imaging is more effective in detecting multiple lesions in patients with neurofibromatosis type I than conventional T2-weighted spin-echo imaging.

Adolescent↗
PubMed1987

Genetic linkage studies of chromosome 17 RFLPs in von Recklinghausen neurofibromatosis (NF1).

Recent localization of the gene for von Recklinghausen neurofibromatosis (NF1) to chromosome 17 has led to studies to identify additional tightly linked probes that can be used in defining the primary genetic defect in NF1. We have examined and obtained blood for DNA linkage studies on over 250 individuals from 10 multigeneration neurofibromatosis families. We have analyzed 130 members in 7 families with the available chromosome 17 NF1 linked probes, pE51, D17S71, and D17Z1, as well as two probes generated from our own chromosome 17/19 enriched library (LDR92, LDR152A). Tight linkage was found between NF1 and the centromeric probe D17Z1 (theta = 0.04) and between NF1 and D17S71 (theta = 0.08). A definite recombinant was seen for the D17Z1 marker, which previously had not exhibited crossingover. Chromosome 17 DNA markers pE51, LDR92, and LDR152A gave slightly positive scores, which were not statistically significant.

Chromosomes, Human, Pair 17↗
PubMed1991

cDNA cloning of the type 1 neurofibromatosis gene: complete sequence of the NF1 gene product.

Von Recklinghausen neurofibromatosis, or type 1 neurofibromatosis (NF1), is a common autosomal dominant disorder characterized by abnormalities in multiple tissues derived from the embryonic neural crest. Portions of the gene have been recently identified by positional cloning, and sequence analysis has shown homology to the GTPase activating protein (GAP) family. In this report we present the results of an extensive cDNA walk resulting in the cloning of the complete coding region of the NF1 transcript. Analysis of the sequences reveals an open reading frame of 2818 amino acids, although alternatively spliced products may code for different protein isoforms. The gene extends for approximately 300 kb on chromosome 17, with its promoter in a CpG-rich island.

Adult↗
PubMed1991

New markers for the neurofibromatosis-2 region generated by microdissection of chromosome 22.

To identify new DNA markers around the neurofibromatosis-2 gene on human chromosome 22, the critical region (22q12-q13.1) was microdissected and microcloned from GTG-banded metaphase chromosomes. Eighteen thousand recombinant clones were obtained. Twenty-seven of 55 clones tested (50%) detected single-copy DNA sequences. Nine of nine clones analyzed in detail were found to map to chromosome 22. Interestingly one clone (EAN04) is part of the leukemia inhibitory factor gene which has previously been mapped to 22q11.2-q13.1. Four clones (EAN01, EAN47, EAN57, and EAN68) detect DNA polymorphisms. These probes were used to compare constitutional and tumor genotypes of 41 patients with acoustic neurinoma. Loss of constitutional heterozygosity was identified in 17 of 31 informative cases (55%). From our data we conclude that the microdissection library is a valuable resource for physical and genetic mapping studies in neurofibromatosis-2.

Chromosome Mapping↗
PubMed2004

Optic radiation involvement in optic pathway gliomas in neurofibromatosis.

PURPOSE: Optic pathway gliomas (pilocytic astrocytomas) in neurofibromatosis type 1 (NF-1) typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is rare. DESIGN: This paper describes seven patients with NF-1 with gliomas involving the pregeniculate optic pathway in addition to the optic radiations. METHODS: A retrospective database review was made of all patients with NF-1 and optic pathway gliomas seen by one of the authors (G.T.L.) at the Children's Hospital of Philadelphia from July 1993 to October 2001. Patients with involvement of pregeniculate optic pathway and the optic radiations were identified. From November 2001 to February 2003, patients were sought prospectively. Cases were also identified from the practice of another author (M.C.B.) at Arkansas Children's Hospital. RESULTS: Four patients from Children's Hospital of Philadelphia (three of 83 total NF-1/optic pathway gliomas from July 1993 to October 2001 and one prospectively) and three from Arkansas Children's Hospital were identified. Two had expanding mass lesions within the white matter of the temporal or parietal lobes, which were histopathologically demonstrated to be pilocytic astrocytomas. The other five had radiographic involvement of the optic radiations but did not undergo biopsy. In three of the cases the vision was 20/200 or worse in each eye. CONCLUSIONS: Optic pathway gliomas in NF-1 may rarely involve the optic radiations. Optic radiation involvement may signal a more aggressive optic pathway glioma in patients with neurofibromatosis-1.

Child, Preschool↗
PubMed2006

Multiple malignant melanomas in association with neurofibromatosis type 1.

We present a case of multiple primary malignant melanomata occurring over a six year period in a 63-year-old Caucasian man with neurofibromatosis type 1. There is doubt regarding a definite association between these two diseases despite a number of case reports and clear, potential pathological mechanisms. This case not only strengthens support for an association but also highlights the great difficulties that arise in the management of cutaneous melanomata in patients with neurofibromatosis.

Humans↗
PubMed2005

The HMG-CoA reductase inhibitor lovastatin reverses the learning and attention deficits in a mouse model of neurofibromatosis type 1.

Neurofibromatosis Type 1 (NF1) is a common neurological disorder caused by mutations in the gene encoding Neurofibromin, a p21Ras GTPase Activating Protein (GAP). Importantly, NF1 causes learning disabilities and attention deficits. A previous study showed that the learning and memory deficits of a mouse model of NF1 (nf1+/-) appear to be caused by excessive p21Ras activity leading to impairments in long-term potentiation (LTP), a cellular mechanism of learning and memory. Here, we identify lovastatin as a potent inhibitor of p21Ras/Mitogen Activated Protein Kinase (MAPK) activity in the brain. Lovastatin is a specific inhibitor of three-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, used commonly for the treatment of hypercholesterolemia. We report that lovastatin decreased the enhanced brain p21Ras-MAPK activity of the nf1+/- mice, rescued their LTP deficits, and reversed their spatial learning and attention impairments. Therefore, these results demonstrate that lovastatin may prove useful in the treatment of Neurofibromatosis Type 1.

Analysis of Variance↗
PubMed2006

Multiple gastrointestinal stromal tumors of the ileum and neurofibromatosis type 1.

Type 1 neurofibromatosis, also known as von Recklinghausen disease, is one of the most common genetic disorders. Gastrointestinal associations have been well described in these patients, but the true incidence of gastrointestinal tumors and the proportion of these becoming clinically significant are not known. The most common gastrointestinal tumors are stromal tumors, most of which are located in the stomach and jejunum. We discuss the case of a female patient with neurofibromatosis whose initial diagnosis was an ovarian mass. During surgery the diagnosis of an intestinal stromal tumor was made. Operative findings were a multilobulated tumor arising from the ileal wall 50 cm from the ileocecal valve. The tumor did not originate from the nervous myenteric plexus or muscular layer of the small bowel wall; it originated from within the stromal cells of the intestinal wall. Mitotic count showed 3 mitoses per 10 high-power fields. Immunohistochemical stains of the tumor showed positive staining for CD117 and CD34 and negative staining for S100, alpha-smooth muscle actin, and desmin. The intestinal myenteric plexus showed positive staining for chromegranin A and S100. The histologic characteristics of this patient's tumor are compatible with an undifferentiated stromal tumor of nonneural or nonmuscular origin.

Adult↗
PubMed2004

Vasculopathy in von Recklinghausen's neurofibromatosis--a diagnostic quandary.

Vasculopathy is a not well-described presentation of neurofibromatosis type 1 in the dermatologic literature. We report a fatal case of neurofibromatosis vasculopathy in a 28-year-old woman who presented with skin ulcers and livedo racemosa; extensive gastrointestinal ulcers; and infarction of the bowel, liver, and spleen. Being alert to this manifestation may avoid unnecessary delay in diagnosis and enable, whenever possible, appropriate therapy.

Adult↗
PubMed2004

Neurofibromatosis type 1 and optic pathway gliomas: follow-up of 54 patients.

OBJECTIVE: To describe the natural history of optic pathway gliomas (OPGs) in patients with neurofibromatosis type 1 (NF1), and to evaluate the current recommended guidelines for monitoring and follow-up of OPGs in this population. DESIGN: Retrospective case series. PARTICIPANTS: Patients with OPGs and NF1 seen in the neurofibromatosis clinic at the Children's Hospital at Westmead in Sydney, Australia. METHODS: Patients with definite NF1 and confirmed OPGs were identified and their medical records searched to obtain data on demographics, details of the OPG diagnosis, and serial ophthalmic examination findings. Patients were stratified into groups according to age and mode of presentation. MAIN OUTCOME MEASURES: Visual acuity was recorded for each eye and grouped into mild (Snellen equivalent > or = 6/12), moderate (Snellen equivalent = 6/15-6/60), and severe (Snellen equivalent < 6/60) visual impairment at time of diagnosis, during follow-up, and at the most recent examination. RESULTS: Data were collected on 54 patients, the majority of whom (78%) were seen from 1990 to 2002, with an average follow-up of 8.6 years. The mean age at the time of OPG diagnosis was 5.2 years, with 32 patients having symptoms or signs at the time of diagnosis. Seventeen patients were diagnosed after the age of 6 years (range, 7-15). Twenty-two patients had tumor progression within 1 year of diagnosis, and a further 6 patients showed progression after 1 year. Most patients' conditions were managed conservatively (68.5%). At follow-up, 17 patients (31.5%) had severe visual impairment (<6/60 Snellen equivalent) in their worse eye, and 16.7% had bilateral moderate/severe visual impairment. CONCLUSIONS: Contrary to some previous reports, our results show that OPGs in patients with NF1 often present in older children and may progress some time after diagnosis. Given the potential for serious visual consequences, these findings indicate a need for regular ophthalmological monitoring of this population for a long duration.

Adolescent↗