Fabrication and Testing of a Bi-2223 Test Coil for High Field NMR Magnets.

In 2005 the Committee on Opportunities in High Magnetic Fields (COHMAG) issued a challenge to develop a 30 T high-resolution NMR magnet. In response, the National High Magnetic Field Laboratory (NHMFL) is investigating all three commercially available high-temperature superconductors (HTS) including REBCO, Bi-2212 and most recently, a reinforced Bi-2223 conductor supplied by Sumitomo Electric, designated Type HT-NX. Recent investigations of Type HT-NX conductor at the NHMFL and by others suggest that operation at hoop stress above 400 MPa, and total strain above 0.7% may be feasible. We have fabricated a test coil from a single 240 m length of HT-NX. The coil was successfully operated to 19.5 T in a 14 T background field, with a total applied strain of 0.8% and coil current density of 243 A/mm2. The coil was cycled 20 times from half the design current to full current without observed degradation.

Variants of the CNTNAP2 5' promoter as risk factors for autism spectrum disorders: a genetic and functional approach.

Contactin-associated protein-like 2 gene (CNTNAP2), a member of the Neurexin gene superfamily, is one of the best-replicated risk genes for autism spectrum disorders (ASD). ASD are predominately genetically determined neurodevelopmental disorders characterized by impairments of language development, social interaction and communication, as well as stereotyped behavior and interests. Although CNTNAP2 expression levels were proposed to alter ASD risk, no study to date has focused on its 5' promoter. Here, we directly sequenced the CNTNAP2 5' promoter region of 236 German families with one child with ASD and detected four novel variants. Furthermore, we genotyped the three most frequent variants (rs150447075, rs34712024, rs71781329) in an additional sample of 356 families and found nominal association of rs34712024G with ASD and rs71781329GCG[7] with language development. The four novel and the three known minor alleles of the identified variants were predicted to alter transcription factor binding sites (TFBS). At the functional level, the respective sequences spanning these seven variants were bound by nuclear factors. In a luciferase promoter assay, the respective minor alleles showed cell line-specific and differentiation stage-dependent effects at the level of promoter activation. The novel potential rare risk-variant M2, a G>A mutation -215 base pairs 5' of the transcriptional start site, significantly reduced promoter efficiency in HEK293T and in undifferentiated and differentiated neuroblastoid SH-SY5Y cells. This variant was transmitted to a patient with autistic disorder. The under-transmitted, protective minor G allele of the common variant rs34712024, in contrast, increased transcriptional activity. These results lead to the conclusion that the pathomechanism of CNTNAP2 promoter variants on ASD risk is mediated by their effect on TFBSs, and thus confirm the hypothesis that a reduced CNTNAP2 level during neuronal development increases liability for ASD.

[The oral vitamin E tolerance test--an attempt at standardization]. / Der orale Vitamin-E-Belastungstest--Versuch einer Standardisierung.

Chronic vitamin E deficiency causes various neurological symptoms such as cerebellar ataxia, hypoesthesia, areflexia, pigmentary retinopathy, nystagmus and muscle weakness. This is commonly caused by malabsorption of vitamin E, which is either a result of malabsorption of fat or occurs as an isolated vitamin E deficiency. The oral vitamin E tolerance test is suitable for the assessment of vitamin E reabsorption and elimination. However, standardised normal parameters have not yet been defined. We investigated 61 healthy individuals aged 18-70 years (mean age, 45.0 years). Each person involved in the trial received 100 IU of all-rac-alpha-tocopherol in 200 millilitres of whole milk. The vitamin E in the serum was then analysed 0, 3, 6, 9, 12, 24, 36, 48, 60, 72 hours after vitamin E was given, using high pressure liquid chromatography. The ratio of vitamin E to the sum of cholesterol and triglycerides was calculated. The 90% CI for the ratio of serum vitamin E to the sum of cholesterol plus triglycerides at the indicated time points was: t = 0 h: 2.0-6.3 micrograms/mg, t = 6 h: 4.2-15.3 micrograms/mg, t = 12 h: 3.0-13.0 micrograms/mg, t = 24 h: 3.8-14.4 micrograms/mg, t = 36 h: 2.9-10.5 micrograms/mg, t = 72 h: 2.1-8.7 micrograms/mg. The serum concentration of vitamin E correlated predominantly with the sum of cholesterol and triglycerides (r = 0.73). The ratio of these parameters is therefore most suitable for diagnosing vitamin E deficiency without relying on false normal serum vitamin E concentrations as a result of abnormally high serum lipid concentrations.