Do central vestibular findings predict abnormal findings on magnetic resonance imaging?

OBJECTIVE: To determine whether central findings from vestibular tests predict abnormal findings on magnetic resonance imaging. METHOD: This study was a retrospective case series at a tertiary referral centre. The main outcome measure of this diagnostic intervention study was the positive predictive value of central vestibular findings in relation to magnetic resonance imaging abnormalities. RESULTS: Central vestibular findings had a 50.9 per cent positive predictive value for magnetic resonance imaging abnormalities across all age groups although they varied according to age group. Optokinetic nystagmus (p < 0.05) and abnormal findings on videonystagmography tests (p < 0.05) were the main predictors of magnetic resonance imaging abnormalities. White matter lesions constituted the bulk of the central lesions on magnetic resonance imaging followed by cortical and cerebellar atrophy. CONCLUSION: Central vestibular findings had a 50.9 per cent positive predictive value for magnetic resonance imaging abnormalities across all age groups. Magnetic resonance imaging is medically justified to further evaluate patients with central findings on vestibular studies. Therefore, it is reasonable to request magnetic resonance imaging in these patients.

[Backache in insurance companies : Occupational health management]. / Rückenschmerz in Versicherungsunternehmen : Betriebliches Gesundheitsmanagement.

AIM OF THE STUDY: The article examines how big German insurance companies handle back pain in terms of occupational health management (OHM). METHODOLOGY: Narrative interviews with experts from 8 out of the 20 biggest enterprises were conducted. RESULTS: Musculoskeletal diseases are the number one or number two reason for sick leave. All enterprises offer OHM; there is a variety of measures, e. g., sport, massage, advice, ergonomics, healthy food and leadership training. The measures are hardly ever evaluated. DISCUSSION: The literature is controversial whether or which OHM measures are effective. In our sample few measures were evaluated; for more evidence based treatment this should be changed.

Ligand binding to transmembrane receptors on intact cells or membrane vesicles measured in a homogeneous 1-microliter assay format.

We have developed homogeneous miniaturized assays to measure ligand binding to either intact cells or receptor-containing membrane fragments by analysis of particle brightness. As an example, the affinities and inhibition constants of fluorescently labeled interleukin-8 (IL-8) and a low-molecular-weight antagonist toward the receptors CXCR1 and CXCR2, which belong to the superfamily of G protein-coupled receptors (GPCRs), were determined. Although the results were generally comparable between the two approaches, the cell-based measurements revealed a more complex pattern of both ligand and inhibitor titration curves, pointing to the influence of intracellular regulatory events. Both the vesicle- and cell-based membrane receptor assays were successfully miniaturized to a total volume of 1 microl without compromising their sensitivity, indicating that screening of transmembrane receptors in these formats is feasible. This is the first report of a cellular ligand-binding assay performed in such low volumes. The resulting savings in reagent could potentially enable the use of primary cells for future HTS/ultra-HTS efforts.

The thermosome: archetype of group II chaperonins.

The thermosome, the chaperonin of the archaea, and its homologue from the cytosol of eukaryotes, known as TRiC or CCT, form a distinct subfamily of the chaperonins that does not depend on a co-chaperonin for protein folding activity. Recent structural data obtained by cryo- electron microscopy and X-ray crystallography provide the first insights into a novel mechanism remarkably different from that of the bacterial GroEL-GroES system.

Structure of the substrate binding domain of the thermosome, an archaeal group II chaperonin.

The crystal structure of the substrate binding domain of the thermosome, the archaeal group II chaperonin, has been determined at 2.3 A resolution. The core resembles the apical domain of GroEL but lacks the hydrophobic residues implied in binding of substrates to group I chaperonins. Rather, a large hydrophobic surface patch is found in a novel helix-turn-helix motif, which is characteristic of all group II chaperonins including the eukaryotic TRiC/CCT complex. Models of the holochaperonin, which are consistent with cryo electron microscopy data, suggest a dual role of this helical protrusion in substrate binding and controlling access to the central cavity independent of a GroES-like cochaperonin.

The thermosome: alternating alpha and beta-subunits within the chaperonin of the archaeon Thermoplasma acidophilum.

The thermosome of the archaeon Thermoplasma acidophilum is composed of two subunits, alpha and beta, which are arranged in two stacked, eight-membered rings. Electron cryo-microscopy in conjunction with image analysis revealed a 4-fold symmetry in the heterooligomeric alpha + beta thermosome isolated from Thermoplasma, but not in the homooligomeric alpha-only thermosome expressed in Escherichia coli. This indicates that alpha and beta-subunits alternate within the rings of the Thermoplasma thermosome rather than forming two different homooligomeric rings. In addition, a small subpopulation of 9-fold symmetric complexes was found among the recombinant alpha-only thermosomes, and a central mass most likely representing bound substrate molecules was observed in about half of the native and recombinant thermosome particles.

Accessory ossifications in the ulno-carpal wrist region.

Accessory ossifications in the ulno-carpal transition such as ossa styloidea or triangularia represent a rare finding, especially among younger individuals. The present results of radiological and morphological investigations show that up to 50% of the ossa are located palmar to the styloid process. Most of them have a sharply bordered contour and are less than 10 mm in length. An aetiological classification of accessory ossifications in the distal epiphyseal region is only possible when an obvious case history is available. Accessory skeletal elements are present among elderly individuals as a result of sclerotic alterations of the ulno-carpal joint elements. Among younger individuals, however, they point to a pathological aetiology and can therefore assume clinical and diagnostic relevance in cases involving inflammatory rheumatic and traumatic alterations accompanied by vague discomfort in the proximal wrist region.

Expression of an archaeal chaperonin in E. coli: formation of homo- (alpha, beta) and hetero-oligomeric (alpha+beta) thermosome complexes.

Co-expression of the two genes encoding the alpha- and beta-subunit of the Thermoplasma acidophilum thermosome in Escherichia coli yielded fully assembled hetero-oligomeric complexes (alpha+beta). Surprisingly, also separate expression of both genes resulted in formation of hexadecameric complexes (alpha, beta) in the bacterial cytoplasm. On electron micrographs these complexes were indistinguishable from each other and from the native thermosome. The recombinant alpha-complex as well as the native thermosome could be reconstituted in vitro from their dissociated subunits in the presence of Mg-ATP.