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J T Epplen

Publications and source records attributed to J T Epplen.

At least 55 records · Page 3Linked to original sources
PubMed2004

Distribution and stability of supernumerary microchromosomes in natural populations of the Amazon molly, Poecilia formosa.

In animals, supernumerary chromosomes and their evolution have mostly been studied in sexual reproducing species. In the present study, for the first time, the natural distribution and stability of supernumerary microchromosomes were investigated in the unisexual fish species Poecilia formosa. Natural habitats throughout the range of P. formosa were screened for the presence of microchromosomes over several years. A high frequency of microchromosomes was found in the Río Purificación river system. Evidence points to the presence of the same microchromosome lineage over many generations. No supernumerary chromosomes were found elsewhere than in the Río Purificación representing a significant difference in the distribution of microchromosome-bearing individuals between the Río Purificación and all other collection sites.

Animals↗
PubMed2004

Respiratory insufficiency as a presenting symptom of LGMD2D in adulthood.

Several forms of recessive limb girdle muscular dystrophy (LGMD2C-F) are due to mutations in genes coding for sarcoglycans. Clinically, most sarcoglycanopathies present in childhood with skeletal muscle wasting and early loss of ambulation; respiratory insufficiency is rare. However, some cases of LGMD2D with a late onset and a milder course have been reported. In this study, two adult brothers, compound heterozygous for two missense mutations of the SGCA gene (Arg77Cys, Val247Met), presented with respiratory insufficiency while they were still ambulatory.

Age of Onset↗
PubMed2003

Neurophysiological findings in SPG4 patients differ from other types of spastic paraplegia.

The authors examined 12 families with autosomal dominant hereditary spastic paraplegia for phenotypic characteristics predicting the underlying genotype. They found no clinical differences between patients with or without mutations in the spastin gene (SPG4). Motor evoked potentials and nerve conduction studies were almost normal in those with SPG4. In contrast, non-SPG4 families had prolonged central motor conduction times or marked peripheral neuropathy, or both.

Adenosine Triphosphatases↗
PubMed2003

A novel splice site mutation in the TRIM37 gene causes mulibrey nanism in a Turkish family with phenotypic heterogeneity.

Mulibrey nanism (muscle-liver-brain-eye nanism; MUL) is an autosomal recessively transmitted disease characterized by severe growth delays of prenatal onset caused by mutations in the TRIM37 gene. Recent studies on the subcellular localization revealed that the TRIM37 (KIAA0898) protein is located in peroxisomes. Therefore, MUL has been classified as a new peroxisomal disorder. Up to now, four mutations have been reported, all of which lead to frameshifts and truncated proteins. In this study, mutation screening was performed for the coding region of the TRIM37 gene in a Turkish family by means of RT-PCR and direct cDNA sequencing. We have identified a novel mutation resulting in a frameshift cosegregating within the family. Finally, we report on the presence of novel splice variants observed in lymphoblastoid cells and muscle tissue of normal subjects and patients.

Base Sequence↗
PubMed2003

Modulation of disease risk according to a cathepsin D / apolipoprotein E genotype in Parkinson's disease.

Aspartyl protease Cathepsin D (CTSD) has been suggested to play a role in the pathogenesis of sporadic Alzheimer's disease (AD) due to interference with protein degradation mechanisms. A C224T (A38V) polymorphism in exon 2 of the CTSD gene is reported to be associated with an increased risk for AD. The partially overlapping pathology between AD and Parkinson's disease (PD) led us to investigate the role of this polymorphism in PD. Using association studies in 457 German PD patients and 340 controls we found no evidence for direct association between the CTSD genotype and PD. However, stratification for the apolipoprotein E (APOE) epsilon4 allele suggests a protective effect of the CTSD T-allele in PD (OR = 0.24, p = 0.002). Our findings suggest interference of CTSD and APOE polymorphisms in the pathogenesis of PD, in the sense of modulating disease risk.

Aged↗
PubMed2003

TNFA promoter polymorphisms and narcolepsy.

Narcolepsy is a debilitating sleep disorder that affects up to 0.05% of individuals in Caucasian populations. It is highly associated with the HLA-DR2 group antigen or the HLA-DRB1*1501-DQB1*0602 haplotype, respectively. However, the HLA association by itself cannot sufficiently explain the increased risk to family members, as HLA-DR2 is quite common in the general population and most people harboring the respective genotype do not develop any symptoms of narcolepsy. Situated in the HLA class II region, the TNFA gene is translated into the pro-inflammatory cytokine TNF-alpha. TNFA promoter polymorphisms have been linked to several inflammatory and autoimmune diseases. We analyzed three SNP of the TNFA promoter and one adjacent microsatellite in 103 patients and 96 controls. The T-allele of the C-857T polymorphism was strongly associated with narcolepsy in the subgroup of DRB1*15/16 (HLA-DR2 type) negative patients, but not in DRB1*15/16 positive patients. These results point towards an etiological influence of TNFA alleles in narcolepsy and support previous findings suggesting genetic heterogeneity and differences in pathophysiological characteristics of HLA-DR2 positive and negative narcolepsy.

Alleles↗
PubMed2003

Increased frequency of migraine in narcoleptic patients: a confirmatory study.

Previously we have reported an increased prevalence of migraine in narcoleptic patients. Because of the theoretical and clinical implications of this finding we recruited an independent new study sample of 100 patients with proven narcolepsy and conducted a structured 26-item interview based on the international diagnostic criteria for headache disorders, the Kiel Headache Questionnaire. Narcolepsy symptoms were measured by means of the Stanford Centre for Narcolepsy Sleep Inventory. Migraine prevalence was twofold to fourfold increased in the narcoleptic patients and amounted to 44.4% in women and 28.3% in men. The onset of narcolepsy symptoms was 12.3 +/- 11.4 years before the onset of migraine symptoms. The results might be regarded as indicative of a common pathophysiological pathway relevant to both of the two disorders.

Adult↗
PubMed2003

Different mRNA expression profile during tumor progression in a well-differentiated liposarcoma--A microdissection approach.

Like malignant fibrous histiocytoma (MFH), dedifferentiated liposarcoma represents a distinct subtype of liposarcoma and is characterized by an abrupt transition from well-differentiated liposarcoma (WDL) to highgrade dedifferentiated liposarcoma (DDL) . In addition, specific cytogenetic aberrations support the close biological relationship between WDL and DDL. Recent observations indicated the significance of cell cycle aberrations in tumor progression from the low-malignant, well differentiated to its dedifferentiated form, the prognosis of which is poor. Thus, alterations of mdm2 and p53 genes belong to the most frequently reported alterations in these two subtypes of liposarcoma. In previous investigations, we reported that loss of heterozygosity at the Rb gene locus, telomerase activity, hTERT, and c-Myc expression were associated with tumor progression in liposarcomas. In this study, we report on a case of a WD/DDL, in which both tumor components were separated using laser microdissection (P.A.L.M.) for the investigation of hTERT mRNA expression on a LightCycler. Macroscopically selected and histologically proven cryosections of low malignant and highly malignant tumor areas were cytogenetically investigated to confirm the diagnosis and to find additional chromosomal alterations with tumor progression.

Aged↗
PubMed2003

Interaction of polymorphisms in the CARD15 and CD14 genes in patients with Crohn disease.

BACKGROUND: Associations of variations in the CARD15 gene (Arg702Trp, Gly908Arg and Leu1007fsinsC) and Crohn disease (CD) have been shown recently. These variations are neither necessary nor sufficient for the genetic predisposition of CD. Further genetic and environmental factors play a crucial role in the pathogenesis of CD. METHODS: To evaluate putative interactions between the CARD15 and CD14 genes in CD, a functionally relevant polymorphism in the promoter region (T/C at position -159) has been genotyped for 650 healthy controls and 253 patients with CD by RFLP analyses. CD patients were genotyped for the variations of the CARD15 gene. RESULTS: T allele and TT genotype frequencies of the CD14 promoter were significantly increased only in CD patients with at least one variation in the CARD15 gene compared to controls (P = 0.02 and 0.0002, respectively). No significant association was found in CD patients without any of the variations. CONCLUSION: Interactions of the CARD15 and CD14 genes, both of which are involved in the recognition of lipopolysaccharides, increase the risk for developing CD.

Carrier Proteins↗
PubMed2002

Mutation analysis of the spastin gene (SPG4) in patients in Germany with autosomal dominant hereditary spastic paraplegia.

Hereditary spastic paraplegias (HSP) comprise a genetically and clinically heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and hyperreflexia of the lower limbs. Autosomal dominant hereditary spastic paraplegia 4 linked to chromosome 2p (SPG4) is the most common form of autosomal dominant hereditary spastic paraplegia. It is caused by mutations in the SPG4 gene encoding spastin, a member of the AAA protein family of ATPases. In this study the spastin gene of HSP patients from 161 apparently unrelated families in Germany was analyzed. The authors identified mutations in 27 out of the 161 HSP families; 23 of these mutations have not been described before and only one mutation was found in two families. Among the detected mutations are 14 frameshift, four nonsense, and four missense mutations, one large deletion spanning several exons, as well as four mutations that affect splicing. Most of the novel mutations are located in the conserved AAA cassette-encoding region of the spastin gene. The relative frequency of spastin gene mutations in an unselected group of German HSP patients is approximately 17%. Frameshift mutations account for the majority of SPG4 mutations in this population. The proportion of splice mutations is considerably lower than reported elsewhere.

Adenosine Triphosphatases↗
PubMed2002

Mutation analysis and association studies of nuclear factor-kappaB1 in sporadic Parkinson's disease patients.

Biochemical and morphological studies revealed that oxidative stress and apoptosis play a role in neurodegeneration in Parkinson's disease (PD). Reactive oxygen species may be directly involved in apoptosis or via upregulation of toxic cytokines, i.e. tumor necrosis factor alpha (TNFalpha). We recently demonstrated that the TNFalpha pathway contributes to the pathogenesis of sporadic PD using a genetic approach. These signalling pathways converge to the transcription factor nuclear factor kappaB (NF-kappaB), which has been found activated in affected neurons in PD. We performed a detailed mutation analysis of the p50 subunit of NF-kappaB (NFKB1 gene) in 96 sporadic PD patients. Previously, positive association was demonstrated in this cohort to chromosome 4q21-23 containing the NFKB1 gene. We identified three base exchanges not affecting the amino acid sequence, which were found at similar frequencies in controls. Our study does not support a genetically definable role of NFKB1 in the pathogenesis of sporadic PD.

Amino Acid Sequence↗
PubMed2002

A null mutation within the ciliary neurotrophic factor (CNTF)-gene: implications for susceptibility and disease severity in patients with multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Impaired remyelination and axonal degeneration may account for progressive disability in MS patients. As ciliary neurotrophic factor (CNTF) takes part in myelogenesis, we examined the frequency of a CNTF-null mutation in 349 MS patients with respect to their clinical presentation and in comparison with 434 healthy controls. Similar genotype frequencies for the CNTF mutation were obtained in MS patients (genotype 0101=74.8%, 0102=22.3%, 0202=2.9%) and controls (genotype 0101=71.7%, 0102=26.5%, 0202=1.8%) even after stratification for the HLA-DRB1*15 allele. In addition, there was no significant correlation of CNTF genotypes to age at onset, course or severity of the disease. We therefore conclude, that the requirement for CNTF in myelogenesis or cell survival may be bypassed by a second ligand or redundancy of functional activity of other neurotrophic factors.

Ciliary Neurotrophic Factor↗
PubMed2002

Inhibitors in the NFkappaB cascade comprise prime candidate genes predisposing to multiple sclerosis, especially in selected combinations.

Multiple sclerosis (MS) is an autoimmune disease displaying different clinical courses. In this multifactorial disease complex environmental as well as genetic predisposition factors contribute to the disease manifestation. Following the candidate gene approach we analysed several genes of the NFkappaB cascade, which are prime candidates for MS because of their involvement in almost all immunological reactions. MS association was excluded for the NFKB1 and NFKB3 genes, which show remarkably low degrees of polymorphism. The genes of NFkappaB inhibitors exhibit more sequence variations. In the IKBL gene a predisposing allele was identified (13.1% vs 7.5% in the control group, P < 0.001). This difference in the allelic distribution was even increased in the group of MS patients with a relapsing remitting course of the disease (14.9%, P < 0.0001). A protecting allele was found in the NFKBIA promotor for the patients with primary progressive MS (15.4% vs 28.4% in the control group, P < 0.01). Given predisposing alleles increase MS risk dramatically in certain combinations.

Adaptor Proteins, Signal Transducing↗
PubMed2002

A polymorphism in the IL11 gene is associated with ulcerative colitis.

Inflammatory bowel diseases (IBD) are multifactorial disorders characterised by the host's inability to limit the inflammatory response to luminal antigens. The association of polymorphisms in the CARD15 gene with Crohn's disease (CD) demonstrates the relevance of activated transcription factor NF(kappa)B in mononuclear cells. Interleukin 11 (IL11) mediates anti-inflammatory effects and is able to downregulate LPS-induced NF(kappa)B activation. The IL11 gene is therefore a good candidate involved in genetic predisposition to IBD. To evaluate the role of the IL11 gene in IBD, two polymorphisms, including a dinucleotide repeat in the promoter region, have been genotyped in 222 patients with CD, 152 patients with ulcerative colitis (UC) and 400 healthy controls. PCR-SSCP analysis of the coding region revealed a single polymorphism in exon 4 leading to an amino acid exchange (G335A; R112H), not significantly associated with either disease. Dinucleotide repeat frequencies of the IL11.A1 allele and of IL11.A1 homozygous individuals were significantly increased among the patients with UC (P < 0.002 and (P < 0.003, respectively) but not with CD. Altered expression of IL11 appears to be involved in the genetic predisposition of UC.

Alleles↗
PubMed2002

Chorea Huntington: a rare case with childhood onset.

Chorea Huntington (CH) is a dominantly inherited, neurodegenerative disease usually with adult onset. The course of CH is characterized by movement disturbances, psychiatric symptoms and it may lead to dementia. Typically death occurs after 10 to 20 years of CH duration. Invariably, the underlying mutation concerns an expansion of a polymorphic (CAG) n stretch in the huntingtin gene. Statistically, larger expansions lead to earlier onset of the disease. We report on a girl with a huntingtin allele of > 140 (CAG) n repeats. Unspecific neurological symptoms were noted at the age of 4.3 years followed by rapid disease progression with psychomotor deterioration.

Alleles↗
PubMed2002

A polymorphism in the CD14 gene is associated with Crohn disease.

BACKGROUND: Inflammatory bowel diseases (IBD) are multifactorial disorders, characterized by failure to limit the inflammatory response to luminal antigens. Although genetic factors play an important role in the pathogenesis, little is known about the genes accountable. Immune response to intestinal bacteria seems to be crucial in the pathogenesis of IBD. METHODS: To evaluate the role of the CD14 gene in IBD, a functionally relevant polymorphism in the promoter region (T/C at position -159) has been genotyped in 219 patients with Crohn disease (CD), 142 patients with ulcerative colitis (UC) and 410 healthy controls by RFLP analysis. RESULTS: T allele and TT genotype frequencies were found increased in CD patients compared to controls (Pc=0.044 and 0.005, respectively). CONCLUSION: An altered immune response to LPS seems to play a role in the genetic predisposition to CD but not to UC.

Alleles↗