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Thomas Gasser

Publications and source records attributed to Thomas Gasser.

69 records · Page 4Linked to original sources
PubMed2003

State of the art review: molecular diagnosis of inherited movement disorders. Movement Disorders Society task force on molecular diagnosis.

This review is designed to provide practical help for the clinical neurologist to make appropriate use of the possibilities of molecular diagnosis of inherited movement disorders. Huntington's disease, Parkinson's disease and parkinsonian syndromes, ataxias, Wilson disease, essential tremor, dystonias, and other genetic diseases associated with a variety of movement disorders are considered separately.

Chromosome Mapping↗
PubMed2003

High-throughput tissue microarray analysis of 11q13 gene amplification (CCND1, FGF3, FGF4, EMS1) in urinary bladder cancer.

Gene amplification is a common mechanism for oncogene overexpression. High-level amplifications at 11q13 have been repeatedly found in bladder cancer by comparative genomic hybridization (CGH) and other techniques. Putative candidate oncogenes located in this region are CCND1 (PRAD1, bcl-1), EMS1, FGF3 (Int-2), and FGF4 (hst1, hstf1). To evaluate the involvement of these genes in bladder cancer, a tissue microarray (TMA) containing 2317 samples was screened by fluorescence in situ hybridization (FISH). The frequency of gains and amplifications of all genes increased significantly from stage pTa to pT1-4 and from low to high grade. In addition, amplification was associated with patient survival and progression of pT1 tumours. Among 123 tumours with amplifications, 68.3% showed amplification of all four genes; 19.5% amplification of CCND1, FGF4, and FGF3; and 0.8% co-amplification of FGF4, FGF3, and EMS1. Amplification of CCND1 alone was found in 9% of the tumours, while EMS1 alone was amplified in 1.6% and FGF4 in 0.8%. Overall, the amplification frequency decreased with increasing genomic distance from CCND1, suggesting that, among the genes examined, CCND1 is the major target gene in the 11q13 amplicon in bladder cancer.

Adenocarcinoma↗
PubMed2003

The epsilon-sarcoglycan gene (SGCE), mutated in myoclonus-dystonia syndrome, is maternally imprinted.

Myoclonus-dystonia syndrome (MDS) is a non-degenerative neurological disorder that has been described to be inherited in an autosomal dominant mode with incomplete penetrance. MDS is caused by loss of function mutations in the epsilon-sarcoglycan gene. Reinvestigation of MDS pedigrees provided evidence for a maternal imprinting mechanism. As differential methylated regions (DMRs) are a characteristic feature of imprinted genes, we studied the methylation pattern of CpG dinucleotides within the CpG island containing the promoter region and the first exon of the SGCE gene by bisulphite genomic sequencing. Our findings revealed that in peripheral blood leukocytes the maternal allele is methylated, while the paternal allele is unmethylated. We also showed that most likely the maternal allele is completely methylated in brain tissue. Furthermore, CpG dinucleotides in maternal and paternal uniparental disomy 7 (UPD7) lymphoblastoid cell lines show a corresponding parent-of-origin specific methylation pattern. The effect of differential methylation on the expression of the SGCE gene was tested in UPD7 cell lines with only a weak RT-PCR signal observed in matUPD7 and a strong signal in patUPD7. These results provide strong evidence for a maternal imprinting of the SGCE gene. The inheritance pattern in MDS families is in agreement with such an imprinting mechanism with the exception of a few cases. We investigated one affected female that inherited the mutated allele from her mother. Surprisingly, we found the paternal wild type allele expressed whereas the mutated maternal allele was not detectable in peripheral blood cDNA.

5-Methylcytosine↗
PubMed2003

Visual evoked potentials for intraoperative neurophysiologic monitoring using total intravenous anesthesia.

Conflicting reports on the usefulness of intraoperative monitoring of visual function by means of visual evoked potentials (VEPs) initiated this study. In 32 patients without visual problems, VEPs were recorded to evaluate the reliability for intraoperative monitoring with total intravenous anesthesia. All patients underwent noncranial surgery. Using a standard technique, VEPs were recorded preoperatively in the awake patients and after induction of anesthesia during surgery. A total of 1436 intraoperative traces were recorded and analyzed. A minor prolongation of the P100 latency of 8% and a more pronounced attenuation of the P100-N145 amplitude of 60% were observed in the anesthetized patients. In most of the anesthetized patients, a stable recording of VEPs was not obtainable. In 4 patients (12.5%), clearly identifiable VEP peaks were detected in more than 90% of the traces recorded intraoperatively. In 88% of the patients, reproducible VEPs were obtained in less than 75% of the intraoperative traces only. We concluded that with standard recording techniques and total intravenous anesthesia, intraoperative VEP monitoring in surgically anesthetized patients is not reliable.

Adult↗
PubMed2002

Prognostic relevance of MAGE-A4 tumor antigen expression in transitional cell carcinoma of the urinary bladder: a tissue microarray study.

TAAs of the MAGE family are mostly studied as targets of specific immune responses. Their potential relevance as tumor markers has also been underlined. We used a MAb, 57B, recognizing MAGE-A4 protein in paraffin-embedded sections, to evaluate its expression in bladder cancers by employing TMA including 2,317 samples from 1,849 patients. In 2,090/2,317 cases (90.2%), immunostaining yielded interpretable results. Since for some patients more than 1 sample was available, only interpretable first biopsies (n = 1,628) were considered. MAGE-A4 protein was expressed at significantly (p < 0.001) higher frequency in squamous (25/55, 45.5%) than in adeno (4/15, 26.7%), sarcomatoid (4/14, 28.6%), small cell (5/20, 25%) or transitional cell (281/1,522, 18.5%) carcinomas. In TCCs, overall MAGE-A4 positivity was significantly correlated with invasive phenotype (p < 0.001) and high tumor grade (p < 0.0001). Clinical data from 908 TCC patients were retrospectively evaluated, revealing that strong 57B staining was highly significantly associated with decreased tumor-specific survival (p < 0.0001). These data suggest that evaluation of MAGE-A4 protein expression is useful in the identification of groups of TCCs characterized by severe prognosis, thus possibly providing indications for early MAGE TAA-targeted immunotherapy.

Antibodies, Monoclonal↗
PubMed2002

Complex relationship between Parkin mutations and Parkinson disease.

Mutations in the Parkin gene cause juvenile and early onset Parkinsonism. While Parkin-related disease is presumed to be an autosomal-recessive disorder, cases have been reported where only a single Parkin allele is mutated and raise the possibility of a dominant effect. In this report, we re-evaluate twenty heterozygous cases and extend the mutation screening to include the promoter and intron/exon boundaries. Novel deletion, point and intronic splice site mutations are described, along with promoter variation. These data, coupled with a complete review of published Parkin mutations, confirms that not only is recessive loss of Parkin a risk factor for juvenile and early onset Parkinsonism but that Parkin haplo-insufficiency may be sufficient for disease in some cases.

Adolescent↗
PubMed2002

Amplification pattern of 12q13-q15 genes (MDM2, CDK4, GLI) in urinary bladder cancer.

The chromosomal region 12q13-q15 is recurrently amplified in bladder cancer. Putative target genes located in this region include MDM2, CDK4, and GLI. To evaluate the involvement of these genes in bladder cancer, we screened a tissue microarray (TMA) containing 2317 samples by fluorescence in situ hybridization (FISH). Amplification was found for MDM2 in 5.1%, for CDK4 in 1.1%, and for GLI in 0.4% of interpretable tumors. Among tumors having amplification of at least one of these 12q13-q15 genes, 76.6% had amplification of MDM2 alone and 6.4% had amplification of CDK4 alone. Coamplifications were seen of MDM2 and CDK4 in 10.6%, and of CDK4 and GLI in 6.4%. Neither coamplifications of all three genes nor isolated GLI amplifications were found. These data suggest a prominent role of MDM2 as a 12q13-q15 amplification target in bladder cancer. However, independent CDK4 amplifications do also occur suggesting either two non-overlapping amplification sites or else a minimal overlapping region between MDM2 and CDK4 perhaps containing another yet unknown oncogene. The frequency of amplification increased significantly from stage pTa to pT1-4 (P<0.04) and from low to high grade (P<0.005). These data are consistent with a high level of genetic instability in invasively growing and high-grade bladder tumors.

Chromosomes, Human, Pair 12↗
PubMed2002

The human sideroflexin 5 (SFXN5) gene: sequence, expression analysis and exclusion as a candidate for PARK3.

Parkinson's disease (PD) is a common neurodegenerative disorder with clinical features of bradykinesia, rigidity and resting tremor resulting from the deficiency of dopamine in the nigrostriatal system. Previously we mapped a susceptibility gene for an autosomal dominant form of PD to a 10.6 cM region of chromosome 2p (PARK3; OMIM 602404). Here we report the identification and characterization of the human sideroflexin 5 gene (SFXN5), which maps to the critical PARK3 region. Database analysis and 5'-RACE (rapid amplification of cDNA ends) identified a 4191 bp cDNA, encoding a predicted protein of 340 amino acids. The genomic sequence and structure of SFXN5 confirmed the cDNA sequence. Northern blot analysis revealed a single SFXN5 transcript of approximately 4.3 kb, which was primarily expressed in the brain. An examination of SFXN5 expression in specific regions of the human brain revealed high levels of expression in all regions analyzed. Sequence analysis of 2p13 linked individuals affected with PD did not reveal any potentially pathogenic mutations within SFXN5, suggesting SFXN5 does not correspond to PARK3.

Amino Acid Sequence↗
PubMed2002

Complex segregation analysis of restless legs syndrome provides evidence for an autosomal dominant mode of inheritance in early age at onset families.

A strong familial component of restless legs syndrome (RLS) is known. The objective of this study therefore was to investigate the likely mode of inheritance of RLS. RLS patients and their first-degree relatives were investigated and classified in RLS affected and RLS nonaffected subjects. Assessments were based on direct, personal standardized diagnostic interviews. Complex segregation analysis was performed with the families stratified according to the mean age at onset of the disease within the families. Two hundred thirty-eight RLS patients, 537 first-degree relatives, and 133 spouses were interviewed. Two groups of families were stratified: mean age at onset up to 30 years of age (Group A) and older than 30 years (Group B; p < 0.005). In Group A, segregation analysis strongly favored a single major gene acting autosomal dominant with a multifactorial component. Parameter estimates were 0.003 for the allele frequency, 1.0 for the penetrance, and 0.005 for the phenocopy rate. In Group B, no evidence for a major gene could be elucidated. The segregation pattern found in our families argues for an autosomal allele acting dominantly in RLS families with an early age at onset of symptoms and suggests that RLS is a causative heterogeneous disease.

Adolescent↗
PubMed2002

Myoclonus-dystonia syndrome: epsilon-sarcoglycan mutations and phenotype.

Mutations in the gene for epsilon-sarcoglycan (SGCE) have been found to cause myoclonus-dystonia syndrome. We now report clinical and genetic findings in nine additional European families with myoclonus-dystonia syndrome. The clinical presentation in 24 affecteds was homogeneous with myoclonus predominantly of neck and upper limbs in 23 of them and dystonia, presenting as cervical dystonia and/or writer's cramp, in 13 cases. Six novel and one previously known heterozygous SGCE mutations were identified. SGCE deficiency seems to be the common pathogenetic mechanism in myoclonus-dystonia syndrome.

Adolescent↗
PubMed2002

VHL mutations and their correlation with tumour cell proliferation, microvessel density, and patient prognosis in clear cell renal cell carcinoma.

Mutations of the von Hippel-Lindau (VHL) gene are considered critical for the initiation of clear cell renal cell carcinoma. The VHL protein is involved in regulation of the cell cycle and neo-vascularization. In this study, the association of VHL mutations with tumour cell proliferation, angiogenesis, and clinical outcome was analysed in 113 clear cell renal cell carcinomas. The degree of angiogenesis and tumour cell proliferation was immunohistochemically determined by counting microvessels (microvessel density, anti-CD34 antibody) and cells with proliferating activity (Ki-67 labelling index, MIB-1 antibody). Forty-eight different VHL sequence alterations were found in 38 of 113 patients (34%) by direct sequencing. Nineteen VHL mutations were frameshifts and nonsense mutations, predicted to change the open reading frame of VHL. These 'loss-of-function' mutations correlated with worse prognosis in univariate analysis (p=0.02). Tumour grade, stage, microvessel density, and tumour cell proliferation were not associated with VHL alterations. These findings may indicate that 'loss-of-function' VHL mutations are involved in the progression of a clear cell renal cell carcinoma subset, whereas regulation of angiogenesis and proliferation of renal carcinoma in vivo is apparently not directly influenced by VHL alterations.

Analysis of Variance↗
PubMed2002

Lipid-mediated glial cell line-derived neurotrophic factor gene transfer to cultured porcine ventral mesencephalic tissue.

Transplantation of dopaminergic ventral mesencephalic (VM) tissue into the basal ganglia of patients with Parkinson's disease (PD) shows at best moderate symptomatic relief in some of the treated cases. Experimental animal studies and clinical trials with allogenic and xenogenic pig-derived VM tissue grafts to PD patients indicate that one reason for the poor outcome of neural transplantation is the low survival and differentiation of grafted dopaminergic neurons. To improve dopaminergic cell survival through a gene-therapeutic approach we have established and report here results of lipid-mediated transfer of the gene for human glial cell line-derived neurotrophic factor (GDNF) to embryonic (E27/28) porcine VM tissue kept as organotypic explant cultures. Treatment of the developing VM with two mitogens, basic fibroblast growth factor and epidermal growth factor, prior to transfection significantly increased transfection yields. Expression of human GDNF via an episomal vector could be detected by in situ hybridization and by the measuring of GDNF protein secreted into the culture medium. When compared to mock-transfected controls, VM tissue expressing recombinant GDNF contained significantly higher numbers of tyrosine hydroxylase-positive neurons in the cultured VM tissue. We conclude that lipid-mediated gene transfer employed on embryonic pig VM explant cultures is a safe and effective method to improve survival of dopaminergic neurons and may become a valuable tool to improve allo- and xenotransplantation treatment in Parkinson's disease.

Animals↗
PubMed2002

PARK6-linked parkinsonism occurs in several European families.

The Parkin gene on 6q25.2-27 is responsible for about 50% of autosomal recessive juvenile parkinsonism and less than 20% of sporadic early-onset cases. We recently mapped a novel locus for early-onset parkinsonism (PARK6) on chromosome 1p35-p36 in a large family from Sicily. We now confirm linkage to PARK6 in eight additional families with Parkin-negative autosomal recessive juvenile parkinsonism from four different European countries. The maximum cumulative pairwise LOD score was 5.39 for marker D1S478. Multipoint linkage analysis gave the highest cumulative LOD score of 6.29 for marker D1S478. Haplotype construction and determination of the smallest region of homozygosity in one consanguineous family has reduced the candidate interval to a 9cM region between markers D1S483 and D1S2674. No common haplotype could be detected, excluding a common founder effect. These families share some clinical features with the phenotype reported for European Parkin-positive cases, with a wide range of ages at onset (up to 68 yrs) and slow progression. However, features typical of autosomal recessive juvenile parkinsonism, including dystonia at onset and sleep benefit, were not observed in PARK6-linked families, thus making the clinical presentation of late-onset cases indistinguishable from idiopathic Parkinson's disease. PARK6 appears to be an important locus for early-onset parkinsonism in European Parkin-negative patients.

Adult↗