The pharmacokinetics and protein-binding of fusidic acid in patients with severe renal failure requiring either haemodialysis or continuous ambulatory peritoneal dialysis

Antibiotic treatment options for Burkholderia cepacia infection are limited because of high intrinsic resistance. The problem is complicated by development of cross-resistance between antibiotics of different classes. We isolated antibiotic-resistant mutants by stepwise exposure to chloramphenicol (Chlor) and to trimethoprim/sulphamethoxazole (T/S) for four B. cepacia strains: ATCC13945, Per (clinical isolate), Cas and D4 (environmental isolates). Chlor(r) mutants did not produce chloramphenicol acetyl-transferase. Cross-resistance, defined as greater than four-fold increase in MIC by microtitre dilution method, was consistently seen in both types of mutants. For chloramphenicol-resistant (Chlor[r]) and trimethoprim/sulphamethoxazole-resistant (Tr/Sr) mutants of B. cepacia ATCC13945 and Cas, no MIC change was seen for piperacillin, ceftazidime, rifampicin, gentamicin, tobramycin, polymyxin B or azithromycin. B. cepacia-Per and -D4 mutants showed cross-resistance to ceftazidime and to piperacillin. Comparison of outer membrane protein (OMP) profiles of B. cepacia and their mutants by SDS-PAGE revealed Tr/Sr) mutants to be deficient in a major OMP (molecular weight 39-47 kDa). Tr/Sr mutants also expressed additional OMPs not found in wild type strains at 75-77 kDa for B. cepacia-ATCC13945 and -Cas, and 20-21 kDa in B. cepacia-D4 and -Per. No OMP changes occurred in Chlor(r) mutants. Lipopolysaccharide (LPS) profiles of each type of mutant showed new high and low molecular weight LPS bands. Cross-resistance seems to be mediated by alterations in porin and LPS for Tr/Sr mutants, but only by LPS in Chlor(r) mutants.     

Context-specific adaptation of vertical vergence to correlates of eye position

Vertical phoria (vertical vergence in the absence of binocular feedback) can be trained to vary with non-visual cues such as vertical conjugate eye position, horizontal conjugate eye position and horizontal vergence. These prior studies demonstrated a low-level association or coupling between vertical vergence and several oculomotor cues. As a test of the potential independence of multiple eye-position cues for vertical vergence, context-specific adaptation experiments were conducted in three orthogonal adapting planes (midsagittal, frontoparallel, and transverse). Four vertical disparities in each of these planes were associated with various combinations of two specific components of eye position. Vertical disparities in the plane were associated with horizontal vergence and vertical conjugate eye position; vertical disparities in the frontoparallel plane were associated with horizontal and vertical conjugate eye position; and vertical disparities in the transverse plane were associated with horizontal vergence and horizontal conjugate eye position. The results demonstrate that vertical vergence can be adapted to respond to specific combinations of two different sources of eye-position information. The results are modeled with an association matrix whose inputs are two classes of eye position and whose weighted output is vertical vergence.     

PROBLEM-SOLVING SUPPORT FOR TQM A Hypertext Approach

New IS technology is contributing to continuous quality improvement throughout the organization. Hypertext and hypermedia offer new ways for decision makers to gain easy and relevant access to information. By combining hypertext with total quality tools, decision makers are able to explore the richness of data bases in more creative and useful ways. This article describes how you can develop a hypertext system that can help employees improve their job performance through better problem solving.     

Displacement control crack-growth instability in an elastic-softening material

The criterion for crack growth instability in an elastic-softening material that is subjected to displacement control loading conditions is examined. A theoretical analysis of the model of a solid containing two symmetrically situated deep cracks and with tensile loading of the remaining ligament, defines the criterion for crack growth instability. The criterion is expressed in terms of the material's softening characteristics and the solid's geometrical parameters. The analysis covers the complete spectrum of material behaviour from the case where the softening zone is very small to the case where instability does not occur until the softening zone traverses the ligament between the crack tips.     

“Metallisation” of oxide surfaces observed by in situ high-resolution electron microscopy

Intense irradiation (25–40 A/cm²) at intermediate energy (400 keV) has been found to cause “metallisation” of tungsten oxide and titanium niobate crystal surfaces. The possible mechanisms and the likely consequences for high-resolution imaging of clean oxide surfaces are briefly discussed.