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Biomedical subjects

I Pilz

Publications and source records attributed to I Pilz.

59 records · Page 4Linked to original sources
PubMedDate not supplied

Phenylalanyl-tRNA synthetase from baker's yeast: structural organization of the enzyme and its complex with tRNAPhe as determined by X-ray small-angle scattering.

The quaternary structure of the phenylalanyl-tRNA synthetase and its complex with tRNAPhe was studied in dilute solutions by small angle X-ray scattering. For the free synthetase the radius of gyration was determined as 5.5 nm, the volume 523 nm3, the maximum diameter 17.5 nm and the molecular weight as 260,000 using an isopotential specific volume of 0.735. The overall shape could be best approximated by a flat cylinder with dimensions 18.2 nmx11.5 nmx4nm; the loose structure was approximated by building up the cylinder by spheres (diameter 4.2 nm). The corresponding parameters of the enzyme tRNA complex were the following: radius of gyration 5.9 nm, volume 543 nm3, maximum diameter 21 nm and molecular weight 290,000. These parameters suggest an 1:1 complex, whereby it must be assumed that the tRNA molecule is attached in the extension of the longer axis. From the difference in the distance distribution functions of the free enzyme and the complex it is evident that we have to assume a change of conformation (contraction) of the enzyme upon the binding of the specific tRNA.

Amino Acyl-tRNA Synthetases↗
PubMedDate not supplied

The Austrian version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ).

We report herein the results of the cross-cultural adaptation and validation into the Austrian language of the parentís version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. The Austrian CHAQ CHQ were adapted from the German version of the CHAQ-CHQ, and revalidated in this study. A total of 134 subjects were enrolled: 74 patients with JIA (9.5% systemic onset, 42% polyarticular onset, 9.5% extended oligoarticular subtype, and 39% persistent oligoarticular subtype) and 60 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the systemic onset, polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the Austrian version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Adolescent↗
PubMedDate not supplied

[Small-angle x-ray and sedimentation studies on alpha-haemocyanin H. pomatia (halve molecules) in glycerol and sucrose solutions (author's transl)].

The alpha-haemocyanin molecules of Helix pomatia were decomposed into halves and studied in solution by small-angle X-ray scattering. The following parameters of the molecule could be obtained: radius of gyration, volume, molecular weight, overall shape and dimensions of the molecule. With small-angle X-ray scattering fluctuations of the electron density within the protein cause parasitic scattering at larger angles. According to Stuhrmann and Kirste it is possible to eliminate it mathematically by varying the electron density of the buffer. For this purpose different quantities of glycerol respectively saccharose were added to the solvent to study the scattering of alpha-haemocyanin halves in solvents of varied electron density. The change of the isopotential specific volume of haemocyanin and the strong increase of the statistical errors of its scattering by decreasing of the excess scattering of solution over solvent per unit volume did not allow an application of the method of Stuhrmann and Kirste. The data obtained for alpha-haemocanin halves in different solvents are given. Besides also the sedimentation of the alpha-haemocyanin halves were studied in solutions containing varied amounts of glycerol and saccharose. An attempt was made to calculate the change of the partial specific volume of haemocyanin by adding glycerol or saccharose.

Animals↗