Near-infrared fluorescent dyes for enhanced contrast in optical mammography: phantom experiments

Optical mammography with near-infrared (NIR) light using time-domain, frequency-domain, or continuous-wave techniques is a novel imaging modality to locate human breast tumors. By investigating excised specimens of normal and diseased mamma tissue we were able to demonstrate that differences in their scattering properties are a poor predictive parameter for normal and diseased mamma tissue. This paper describes the application of a NIR dye to improve the differentiation between breast tumors and normal tissue in a rat model. The NIR dye furnished a high tumor-to-tissue contrast ratio (6:1) in fluorescence images. Furthermore, this dye was used to develop liquid scattering phantoms with absorbing and fluorescent inhomogeneities. Using frequency-domain and time-domain instrumentation these inhomogeneities were localized at sufficient contrast by their increased absorption and fluorescence. Contrast between inhomogeneities and surrounding medium could be improved by combining fluorescence and transmittance images.     

Clinical significance of the corrected orthogonal ECG (Frank) in comparison with conventional ECG for the detection of coronary heart disease

The clinical evidence of the two derivation systems is of the same value concerning the recognition of the coronary heart disease. Their information range does not significantly differ from each other statistically, when scale and vectorial parameters of the corrected orthogonal ECG after Frank are taken into consideration. But in individual cases clear differences may be present, such as the insufficient representation of localized precordial potential losses in the corrected orthogonal ECG. With the help of the discriminance analysis the high number of falsely negative findings of the ECG after resting can be reduced from about 45% to 15% to 20%. Within a diagnostic stage programme from the recognition and care of particularly endangered patients with coronary heart disease the corrected orthogonal ECG is suited, when a discriminance-analytic valuation with scale and vectorial parameters is made. In contrast to the conventional ECG it has the advantage that it is more rapidly and less expensively to be evaluated by computers.     

Genomic and Functional Portrait of a Highly Virulent,CTX-M-15-Producing H30-Rx Subclone of Escherichia coli Sequence Type 131

Escherichia coli sequence type 131 (ST131) is a pandemic clone associated with multidrug-resistant, extraintestinal infections, attributable to the presence of the CTX-M-15 extended-spectrum β-lactamase gene and mutations entailing fluoroquinolone resistance. Studies on subclones within E. coli ST131 are critically required for targeting and implementation of successful control efforts. Our study comprehensively analyzed the genomic and functional attributes of the H30-Rx subclonal strains NA097 and NA114, belonging to the ST131 lineage. We carried out whole-genome sequencing, comparative analysis, phenotypic virulence assays, and profiling of the antibacterial responses of THP1 cells infected with these subclones. Phylogenomic analysis suggested that the strains were clonal in nature and confined entirely to a single clade. Comparative genomic analysis revealed that the virulence and resistance repertoires were comparable among the H30-Rx ST131 strains except for the commensal ST131 strain SE15. Similarly, seven phage-specific regions were found to be strongly associated with the H30-Rx strains but were largely absent in the genome of SE15. Phenotypic analysis confirmed the virulence and resistance similarities between the two strains. However, NA097 was found to be more robust than NA114 in terms of virulence gene carriage (dra operon), invasion ability (P < 0.05), and antimicrobial resistance (streptomycin resistance). RT² gene expression profiling revealed generic upregulation of key proinflammatory responses in THP1 cells, irrespective of ST131 lineage status. In conclusion, our study provides comprehensive, genome-inferred insights into the biology and immunological properties of ST131 strains and suggests clonal diversification of genomic and phenotypic features within the H30-Rx subclone of E. coli ST131.     

Limb immobilization alters muscle activation patterns during a fatiguing isometric contraction

The purpose of the study was to determine the role of excitation-contraction coupling in the increased endurance time for low-force contractions after 4 weeks of elbow joint immobilization. Twelve subjects participated in a protocol that required immobilization of the elbow joint in a fiberglass cast for 4 weeks, and 4 subjects acted as controls. Measurements of muscle strength, contractile properties, and fatigability were performed before and after 4 weeks of limb immobilization, and after 4 weeks of recovery. The immobilization intervention produced significant reductions in the daily activity of the elbow flexor muscles, a 21% decline in the maximum voluntary contraction (MVC) force, and a 31% decrease in the maximum load that could be lifted once. Seven of the immobilized subjects exhibited an unusual pattern of muscle activity during the fatiguing contraction after immobilization, which was associated with an increase in the endurance time of the elbow flexor muscles (mean = 220%) in these subjects. The unusual pattern of muscle activity involved lower relative activity of the brachialis muscle, no increase in the amplitude of the electromyogram (EMG) for the elbow flexor muscles, and intermittent rather than continuous EMG. In contrast, the force-frequency relationship of biceps brachii was not altered by immobilization in these subjects, suggesting that adaptations in excitation-contraction coupling were not the primary cause of the prolonged endurance time after immobilization. Rather, the results suggest that the prolonged endurance time exhibited by some subjects after immobilization was largely due to adaptations within the nervous system.     

Morphological study of Osteoplate 2000-extension implants after bending

Unfavorable anatomical conditions of implant sites often require the insertion of implants in a direction that may interfere with the positioning of suprastructural elements in a functionally and esthetically satisfying manner. In some implant systems, bending of the implant neck is one of the possible methods for optimizing the insertion angle for the superimposed prosthesis. The aim of this study was to investigate whether bending procedures of the implant neck cause changes in the surface properties at the implant neck area. After bending of the implant neck up to 30 degrees, scanning electron microscopy revealed changes in the surface texture of the titanium. Superficial rips approximately 5 microns wide and 100 microns long had formed. These findings were confirmed by metallographic examinations. Values of Vickers hardness testing in the implant neck area after bending of 30 degrees showed significant differences between the compression or stretched zone and the neutral zone of the bending area. Bending of the implant neck between 0 and 20 degrees may influence the surface morphology, promoting superficial rips. Plaque accumulation and mechanically induced mucosal irritations due to changes of surface morphology and properties by bending should be further analyzed.