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Biomedical subjects

R Schnabel

Publications and source records attributed to R Schnabel.

At least 127 records · Page 7Linked to original sources
PubMed1983

Archaebacteria and eukaryotes possess DNA-dependent RNA polymerases of a common type.

DNA-dependent RNA polymerases of archaebacteria not only resemble the nuclear RNA polymerases of eukaryotes rather than the eubacterial enzymes in their complex component patterns but also show striking immunochemical, i.e., structural, homology with the eukaryotic polymerases at the level of single components. Thus, eukaryotic and archaebacterial RNA polymerases are indeed of the same type, distinct from the eubacterial enzymes, which, however, are also derived from a common ancestral structure.

Archaea↗
PubMed1983

Karyotype 47,XXY,18p--in a newborn child with holoprosencephaly.

This may be the first reported case of a 47,XXY,18p--("Klinefelter-de Grouchy I syndrome"), in a post-term male neonate. The child had a dysmorphic facies, a small nose with a single orifice, cranial malformations and an alobar holoprosencephaly. These symptoms corresponded with the known phenotypic variants of the simple 18p--anomaly. The karyotypes of both parents were normal.

Abnormalities, Multiple↗
PubMed1982

Component E of the DNA-dependent RNA polymerase of the archaebacterium Thermoplasma acidophilum is required for the transcription of native DNA.

The role of component E of the DNA-dependent RNA polymerase of the archaebacterium Thermoplasma acidophilum in the transcription of Thermoplasma DNA has been analyzed. Component E (Mr 22000) is released upon formation of the binary complex of the polymerase with the DNA. Enzyme not containing component E is inactive on DNA but active on poly[d(A-T) X d(A-T)]. The activity on DNA can be restored by addition of component E. Two states of the binding complex between RNA polymerase and DNA, differing in their ionic strength stabilities, have been distinguished both in the presence and absence of component E. The transition temperature between the two states is 43 degrees C. Component E appears to open productive binding sites in native DNA in addition to the non-productive strong binding sites available for component-E-deficient enzyme.

Bacterial Proteins↗
PubMed1982

Halobacterium halobium phage øH.

Phage øH, a novel virus of the archaebacterium Halobacterium halobium, resembles in size and morphology two other Halobacterium phages. One-step growth curves show a 5.5 h eclipse, a latent period of 7 h, and an apparent burst size of 170. Phage øH contains linear, double-stranded DNA which has a molecular weight of 39 x 10 and a GC content of 65%. A packaging model accounting for the partial circular permutation and terminal redundancy of øH DNA is suggested. Partial homology of øH DNA with the DNA of H. halobium, predominantly with the AT-rich satellite DNA, was observed. The presence of minor restriction fragments of øH DNA which could be removed by purification of phage from single plaques suggests the existence of phage variants with rearranged DNA. A strain of H. halobium containing øH DNA was isolated which is resistant to infection by phage øH.

Journal Article↗
PubMed1981

Histopathological findings in adrenoleukodystrophy autopsy report of a boy aged 11 years and 11 months.

Clinical and pathohistological findings of a boy who died of adrenoleukodystrophy at the age of 11 years and 11 months are reported. Special features are the advanced diffuse demyelination of cerebral and cerebellar white matter as well as the "burnt-out" stage of myelin breakdown with fibrous gliosis. The leukodystrophic process is accompanied by secondary loss of axons with marked atrophy of grey matter in the whole of the brain stem, dentates and cerebellar cortex of the Purkinje cell type. The degeneration of nerve fibres is considered as a complex mechanism, which is not restricted to the Wallerian type. -- Only free cholesterol was shown by histochemical tests in the preserved myelin sheaths. Free and esterified cholesterol was found in the adrenal cortical cells. The lack of detectable cholesteryl esters in the sparse sudanophilic macrophages was unexpected. This finding may be attributed to the sensitivity of the histochemical method or to interference by achromogenic 7-ketocholesterol.

Adrenal Insufficiency↗