17β-estradiol protects 7-day old rats from acute brain injury and reduces the number of apoptotic cells

To test a possible neuroprotective activity of 17β-estradiol in the neonatal rat brain exposed to hypoxic-ischemia (controlled hypoxia after unilateral carotid artery ligation).

Development of a genotyping microarray for Usher syndrome

BACKGROUND: Usher syndrome, a combination of retinitis pigmentosa (RP) and sensorineural hearing loss with or without vestibular dysfunction, displays a high degree of clinical and genetic heterogeneity. Three clinical subtypes can be distinguished, based on the age of onset and severity of the hearing impairment, and the presence or absence of vestibular abnormalities. Thus far, eight genes have been implicated in the syndrome, together comprising 347 protein-coding exons. METHODS: To improve DNA diagnostics for patients with Usher syndrome, we developed a genotyping microarray based on the arrayed primer extension (APEX) method. Allele-specific oligonucleotides corresponding to all 298 Usher syndrome-associated sequence variants known to date, 76 of which are novel, were arrayed. RESULTS: Approximately half of these variants were validated using original patient DNAs, which yielded an accuracy of >98%. The efficiency of the Usher genotyping microarray was tested using DNAs from 370 unrelated European and American patients with Usher syndrome. Sequence variants were identified in 64/140 (46%) patients with Usher syndrome type I, 45/189 (24%) patients with Usher syndrome type II, 6/21 (29%) patients with Usher syndrome type III and 6/20 (30%) patients with atypical Usher syndrome. The chip also identified two novel sequence variants, c.400C>T (p.R134X) in PCDH15 and c.1606T>C (p.C536S) in USH2A. CONCLUSION: The Usher genotyping microarray is a versatile and affordable screening tool for Usher syndrome. Its efficiency will improve with the addition of novel sequence variants with minimal extra costs, making it a very useful first-pass screening tool.

Different amino acid substitutions at the same position in rhodopsin lead to distinct phenotypes

PURPOSE: Identification of a novel rhodopsin mutation in a family with retinitis pigmentosa and comparison of the clinical phenotype to a known mutation at the same amino acid position. METHODS: Screening for mutations in rhodopsin was performed in 78 patients with retinitis pigmentosa. All exons and flanking intronic regions were amplified by PCR, sequenced, and compared to the reference sequence derived from the National Center for Biotechnology Information (NCBI, Bethesda, MD) database. Patients were characterized clinically according to the results of best corrected visual acuity testing (BCVA), slit lamp examination (SLE), funduscopy, Goldmann perimetry (GP), dark adaptometry (DA), and electroretinography (ERG). Structural analyses of the rhodopsin protein were performed with the Swiss-Pdb Viewer program available on-line (http://www.expasy.org.spdvbv/ provided in the public domain by Swiss Institute of Bioinformatics, Geneva, Switzerland). RESULTS: A novel rhodopsin mutation (Gly90Val) was identified in a Swiss family of three generations. The pedigree indicated autosomal dominant inheritance. No additional mutation was found in this family in other autosomal dominant genes. The BCVA of affected family members ranged from 20/25 to 20/20. Fundus examination showed fine pigment mottling in patients of the third generation and well-defined bone spicules in patients of the second generation. GP showed concentric constriction. DA demonstrated monophasic cone adaptation only. ERG revealed severely reduced rod and cone signals. The clinical picture is compatible with retinitis pigmentosa. A previously reported amino acid substitution at the same position in rhodopsin leads to a phenotype resembling night blindness in mutation carriers, whereas patients reported in the current study showed the classic retinitis pigmentosa phenotype. The effect of different amino acid substitutions on the three-dimensional structure of rhodopsin was analyzed by homology modeling. Distinct distortions of position 90 (shifts in amino acids 112 and 113) and additional hydrogen bonds were found. CONCLUSIONS: Different amino acid substitutions at position 90 of rhodopsin can lead to night blindness or retinitis pigmentosa. The data suggest that the property of the substituted amino acid distinguishes between the phenotypes.

The syndromology of anorectal malformations revisited: from patterns of associated malformations to the recognition of syndromes

ackground: Although the frequency of associated malformation is high, the incidence of inheritable syndromes is widely underestimated in children with anorectal malformation (ARM). Data sources: OMIM database, patient records and charts of the Department of Pediatric Surgery, Johannes Gutenberg-University, Mainz, Germany. Methods: We analyzed all associations, sequences and syndromes listed in the OMIM database that can be accompanied by ARM. A large cohort of children born with ARM was then retrospectively investigated as to the type of ARM, presence of additional malformations and possible categorization as a syndrome, sequence or association. For this process a syndrome finder was developed and employed. This simplistic tool allows for a rapid first check of possible syndromes before a more complex analysis is started using the OMIM database and consulting specialists. Results: Among 317 children with ARM, associated malformations were present in 77.7% of 127 children with high ARM, in 68.7% of 32 with intermediate ARM, and in 25.3% of 158 with a low type ARM. Three or more organ systems were involved in 29.1% children with high type ARM and 25% with intermediate ARM and 8.2% with a low type ARM. An association of the vertebral anal tracheo-esophageal renal (VATER) and vertebral anal cardiac tracheo-esophageal renal limb (VACTERL) type was found in a total of 35 patients. Before analysis, 11 syndromes and 35 associations which were not clear previously in this patient cohort were described. In other 17 patients, 14 syndromes and 3 associations were identified. Conclusions: The high number of only retrospectively identified syndromes suggests that a routine search is necessary in every patient with ARM and additional malformations.