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Biomedical subjects

A Hahn

Publications and source records attributed to A Hahn.

At least 145 records · Page 8Linked to original sources
PubMed1975

Molecur mechanism of action of the radioprotective substance WR 2721.

The radioprotective effect of WR 2721 on catalase and the type and loci of its interaction with the enzyme have been investigated by means of spectrophotometric and electron spin resonance, (ESR) methods. The radiation damage, indicated by a change in enzymatic activity and in the Soret absorption band, has been the less the larger the WR 2721 concentration. In the case of ESR investigations, addition of WR 2721 has resulted in a reduction of the spin concentration of Cu-2+. Since cysteamine has exhibited similar results, however, to a lesser extent, it can be assumed that the RS-ions are responsible for the protective effect. From the results obtained it can be concluded that (the dephosphorilized) WR 2721 forms a complex with the enzyme and acts as an electron donor.

Animals↗
PubMedDate not supplied

[Cervical myelopathy in a newborn with achondroplasia].

BACKGROUND: Patients with achondroplasia have an increased risk of apnoea due to cervical myelopathy. The indication for operative decompression can not be made by MRI alone, because signal alteration and osseous compression of the cervico-medullary region without functional relevance are frequent in this disease. CASE REPORT: We report on a male new-born with achondroplasia who displayed apnoeas from the first day of life. Two times, mask ventilation had to be performed. After exclusion of other diseases potentially causing apnoeas, an MRI of the skull and cervical spine revealed cervico-medullary compression due to foramen magnum stenosis, but no signal alterations of brain stem and cervical mark. Recording of somato-sensory evoked potentials (SSEP) of the median nerve showed normal potentials at Erb's point. By contrast, cortical potentials were distinctly abnormal during left-sided stimulation and could not be recorded during right-sided stimulation. Based on these findings, operative decompression of the craniocervical region was performed which led immediately to complete remission of clinical symptoms. At follow-up, MRI revealed a normal width of the foramen magnum and SSEP were markedly improved. CONCLUSION: In newborns with Achondroplasia, SSEP can confirm the functional relevance of osseous compression of the cervico-medullary region, and facilitate the decision for operative decompression.

Achondroplasia↗
PubMedDate not supplied

[L-2-hydroxyglutaric aciduria -- a rare cause of macrocephaly].

We report on a 9-year-old girl who was referred to our department because of increasing macrocephaly and school problems. The neurological examination disclosed mild cerebellar dysfunction and positive pyramidal tract signs. An MRI of the brain revealed extensive signal alterations of the white matter. Biochemical investigations established the diagnosis of L-2-hydroxyglutaric aciduria which has to be kept in mind as a rare cause of macrocephaly.

Adolescent↗