We tested the event-indexing model proposed by Zwaan, Langston, and Graesser (1995). Participants read narratives containing target sentences that involved situational shifts. Independently of each other, continuity and shifting of the protagonist, time, and location dimensions were varied. In Experiment 1, reading times of the target sentences increased for protagonist shifts and temporal shifts, whereas the effect of spatial shifts was weak. Moreover, an interaction of protagonist shifts and spatial shifts was found. These results were replicated in Experiment 2, which also revealed strong effects of these situational shifts on coherence ratings that participants gave immediately after reading each target sentence. Experiment 3 addressed the interaction of protagonist shifts and spatial shifts, showing that it may be due to the differential involvement of unexplained protagonist motions. These experimental results support the processing load predictions of the event-indexing model and extend previous correlational results.

To study the association between vertebral deformities and subjective health outcome indicators, including back pain and disability, a cross-sectional survey with spinal radiographs and personal interviews was carried out in 36 study centres in 19 European countries on a total of 15,570 men and women aged 50-79 years (population-based stratified random samples). No interventions were done. The main outcome measures were the presence and intensity of current and previous back pain, functional capacity (ADL questionnaire) and overall subjective health. The presence and intensity of back pain and functional and health impairments varied within wide ranges with no obvious regional pattern. However, the associations between negative health outcomes and vertebral deformity were homogeneous between countries and between centres within countries. In logistic regression analyses weak but significant associations between the presence of vertebral deformities and various health indicators were demonstrated. The magnitude of the associations increased with severity and number of deformities. Compared with subjects without deformities those with low-grade deformities had no or only a weakly elevated risk for back pain, disability and impaired subjective health (odds ratios (OR) 1.2-1.3). The odds ratios increased for individuals with single severe deformities (OR 1.3-2.1) and were highest in those with multiple severe deformities (OR 1.7-4.2). The associations between vertebral deformities and negative health outcomes were stronger in men than in women. In this cross-sectional study radiologically assessed vertebral deformities were therefore weakly associated with both current and previous back pain as well as with functional and health impairments in both women and men. Multiple severe deformities were associated with severe and disabling back pain with stronger effects in men.

Riboflavin overproduction in the ascomycete Ashbya gossypii is limited by glycine, a precursor of purine biosynthesis, and therefore an indicator of glycine metabolism. Disruption of the SHM 2 gene, encoding a serine hydroxymethyltransferase, resulted in a significant increase in riboflavin productivity. Determination of the enzyme's specific activity revealed a reduction from 3 m-units/mg of protein to 0.5 m-unit/mg protein. The remaining activity was due to an isoenzyme encoded by SHM 1, which is probably mitochondrial. A hypothesis proposed to account for the enhanced riboflavin overproduction of SHM 2-disrupted mutants was that the flux from glycine to serine was reduced, thus leading to an elevated supply with the riboflavin precursor glycine. Evidence for the correctness of that hypothesis was obtained from (13)C-labelling experiments. When 500 microM 99% [1-(13)C]threonine was fed, more than 50% of the label was detected in C-1 of glycine resulting from threonine aldolase activity. More than 30% labelling determined in C-1 of serine can be explained by serine synthesis via serine hydroxymethyltransferase. Knockout of SHM 1 had no detectable effect on serine labelling, but disruption of SHM 2 led to a decrease in serine (2-5%) and an increase in glycine (59-67%) labelling, indicating a changed carbon flux.

Na⁺ and Cl^– currents were studied in primary cultures of human nasal epithelium derived from non-cystic fibrosis (non-CF) and cystic fibrosis (CF) patients. We found that Na⁺ absorption dominates transepithelial transport and the Na⁺ current contains an amiloride-sensitive and amiloride-insensitive component. In non-CF tissue both components contribute about equally to the entire short-circuit current (I_SC), whereas in CF tissues the major part of the current is amiloride-sensitive. Na⁺ removal reduced I_SC to values close to zero. Several Cl^– channel blockers were used to identify the remaining tiny Na⁺-independent current. Under unstimulated, physiological conditions in the presence of Cl^– on both sides and amiloride on the apical side of the epithelium diphenylamine-2-carboxic acid (DPC), 4,4′-diisothiocyanatostilbene-2,2′- disulfonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) failed to induce clearcut inhibition of I_SC. cAMP as well as ATP did not affect I_SC either in CF or in non-CF epithelia. Reduction of apical Cl^– increased I_SC and depolarized transepithelial potential; however, the observed increase was insensitive to DIDS, DPC and NPPB. From these data we conclude that Cl^– conductances in primary cultures of human nasal epithelium derived from CF patients as well as from non-CF patients are present only in low numbers or do not contribute significantly to transepithelial ion transport.

Alanine : glyoxylate aminotransferase is one of three different enzymes used for glycine synthesis in Saccharomyces cerevisiae. The open reading frame YFL030w (named AGX1 in the following), encoding this enzyme, was identified by comparing enzyme specific activities in knockout strains. While 100% activity was detectable in the parental strain, 2% was found in a YFL030w::kanMX4 strain. The ORF found at that locus was suspected to encode alanine : glyoxylate aminotransferase because its predicted amino acid sequence showed 23% identity to the human homologue. Since the YFL030w::kanMX4 strain showed no glycine auxtrophic phenotype, AGX1 was replaced by KanMX4 in a GLY1 SHM1 SHM2 background. These background mutations, which cause inactivation of threonine aldolase, mitochondrial and cytosolic serine hydroxymethyltransferase, respectively, lead to a conditional glycine auxotrophy. This means that growth is not possible on glucose but on ethanol as the sole carbon source. Additional disruption of AGX1 revealed a complete glycine auxotrophy. Complementation was observed by transformation with a plasmidencoded AGX1.

Solitary enchondroma is a benign bone tumor with a doubtful prognosis changing by topical but not by clinical, roentgenological or histological characteristics. Therefore benign solitary enchondroma should be subdivided in such of peripheral and such of central localisation. Both forms of enchondroma normally show an asymptomatic development. Diagnostic problems occur in central enchondroma because of its radiological, angiographical and szintigraphical aspects. Peripheral enchondroma should be treated by local excision. Recurrences after local treatment are extremely rare. In treatment of central enchondroma bone resection should be performed following common principles of onkological radicality. Local excision is not sufficient; amputation should be reserved for treatment of chondroma close to the trunk or chondrosarcoma.

Fractures of osteoporotic vertebral bodies are increasingly stabilized with bone cement. The effects of vertebral-body stiffness before and after augmentation with bone cement and of wedge-shaped vertebral body fractures on intradiscal pressure are insufficiently known. In a finite element model of the lumbar spine the elastic modulus of cancellous bone as well as the amount and the elastic modulus of bone cement were varied and the dependency of intradiscal pressure on these parameters was calculated. In addition, a wedge-shaped vertebral-body fracture was simulated. The bulge of the vertebral-body endplate and thus the intradiscal pressure depends strongly on the grade of osteoporosis in the vertebral body. The influence of amount and elastic modulus of bone cement on intradiscal pressure is small. A wedge-shaped vertebral-body fracture causes an anterior shift of upper-body centre of gravity. If this shift is not compensated, it leads to an increased flexion moment that has to be balanced by muscle forces. In addition, this shift leads to a stronger increase of intradiscal pressure than the augmentation of the vertebral body with bone cement.

The current operative approaches and technical possibilities in the operative treatment of spinal metastases are manifold which enables an individual operative strategy adapted to the patient's condition. Maintaining quality of life is the primary goal in the treatment of these patients. The therapeutic goals, such as pain control, avoidance of neurological deficits and the achievement of spinal stability have to be attained with as little morbidity as possible. From this perspective the available operative techniques ranging from minimally invasive approaches to complex reconstructive surgery will be addressed and discussed in this article.