Infectious mononucleosis and unilateral tongue writhing.
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Biomedical subjects
Publications and source records attributed to Birgit Petersen.
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The Saethre-Chotzen syndrome (SCS) is an autosomal dominant craniosynostosis syndrome with uni- or bilateral coronal synostosis and mild limb deformities. It is caused by loss-of-function mutations of the TWIST 1 gene. In an attempt to delineate functional features separating SCS from Muenke's syndrome, we screened patients presenting with coronal suture synostosis for mutations in the TWIST 1 gene, and for the Pro250Arg mutation in FGFR3. Within a total of 124 independent pedigrees, 39 (71 patients) were identified to carry 25 different mutations of TWIST 1 including 14 novel mutations, to which six whole gene deletions were added. The 71 patients were compared with 42 subjects from 24 pedigrees carrying the Pro250Arg mutation in FGFR3 and 65 subjects from 61 pedigrees without a detectable mutation. Classical SCS associated with a TWIST 1 mutation could be separated phenotypically from the Muenke phenotype on the basis of the following features: low-set frontal hairline, gross ptosis of eyelids, subnormal ear length, dilated parietal foramina, interdigital webbing, and hallux valgus or broad great toe with bifid distal phalanx. Functional differences were even more important: intracranial hypertension as a consequence of early progressive multisutural fusion was a significant problem in SCS only, while mental delay and sensorineural hearing loss were associated with the Muenke's syndrome. Contrary to previous reports, SCS patients with complete loss of one TWIST allele showed normal mental development.
We developed a quartz crystal biosensor designed to detect concentrations and ligand affinity parameters of free unlabeled proteins in real time. Using a model system with human IgE as the analyte and single-stranded DNA aptamers or an anti-IgE antibody as immobilized ligands, we could demonstrate that aptamers were equivalent to antibodies in terms of specificity and sensitivity. Both receptor types selectively detected 0.5 nmol/L of IgE. In addition, the aptamer receptors tolerated repeated affine layer regeneration after ligand binding and recycling of the biosensor with little loss of sensitivity. Because of the small size and nonprotein nature of the aptamers, they were immobilized in a dense, well-oriented manner, thus extending the linear detection range to 10-fold higher concentrations of IgE. In addition to demonstrating for the first time that an aptamer-based biosensor can specifically and quantitatively detect an analyte in various complex protein mixes, the aptamer-ligand proved to be relatively heat resistant and stable over several weeks. Since aptamers consist of nucleic acids, well-established chemistry can be applied to produce optimized affine layers on biosensors that may be developed to specifically detect proteins in solution for analysis of proteomes.
In order to gain new insight into the pathogenesis and nosography of benign partial epilepsy with occipital paroxysms (BEOP) we retrospectively analysed cases with benign focal sharp waves (SHW) of different localisations, in which analogous EEG changes had been found in at least one first degree relative. Fifty-six families were evaluated. Nineteen cases with occipital SHW (group A) were compared with 37 cases without (group B). There was a broad spectrum of symptomatology with large overlaps between the two groups. However, a number of striking differences, yielding a characteristic picture of early childhood epilepsy with occipital foci were identified: (1) Age of onset under 5 years; (2) a larger proportion of febrile convulsions (FC 47 vs. 19%); (3) a trend towards a higher rate of typical early childhood occipital seizures (26 vs. 5%); (4) a higher rate of frontal and generalizing SHW foci (32 vs. 5%; 37 vs. 11%); (5) a higher rate of generalized spikes and waves (SW) (46 vs. 14%); (6) a trend towards a higher rate of photoparoxysmal response (PPR) (57 vs. 32%). The high prevalence of independent genetic traits favours a multifactorial pathogenesis. The predisposition to FC with characteristic early seizure onset and varying patterns of generalized genetic EEG traits plays a crucial role within the complex pathogenetic network. The early-onset benign childhood occipital seizure susceptibility syndrome of Panayiotopoulos (Benign Childhood Partial Seizures and Related Epileptic Syndromes, John Libbey & Company Ltd., London (1999)) cannot be regarded as the sole representative of occipital spikes in early childhood but as an important even though rare form of occipital epilepsy.