Bücherschau

Ohne Zusammenfassung VDI     

N-alpha-tosyl-L-lysine chloromethylketone prevents expression of iNOS in vascular smooth muscle by blocking activation of NF-kappa B

OBJECTIVE: To demonstrate that an agreement approach to applying equations on the basis of clinical and exercise test variables is an accurate, self-calibrating, and cost-efficient method for predicting severe coronary artery disease in clinical populations. DESIGN: Retrospective analysis of consecutive patients with complete data from exercise testing and coronary angiography referred for evaluation of possible coronary artery disease. After developing an equation in a training set, this equation and two other equations developed by other investigators were validated in a test set. The study was performed at two university-affiliated Veteran's Affairs medical centers. PATIENTS: 1080 consecutive men studied between 1985 and 1995 who had coronary angiography within 3 months of the treadmill test. The population was randomly divided into a training set of 701 patients and a test set of 379 patients. Patients with previous coronary artery bypass surgery, valvular heart disease, marked degrees of resting ST depression, and left bundle branch block were excluded. MEASUREMENTS: Recording of clinical and exercise test data along with visual interpretation of the electrocardiogram recordings on standardized forms and abstraction of visually interpreted angiographic data from clinical catheterization reports. RESULTS: Simple clinical and exercise test variables improved the standard application of exercise-induced ST criteria for predicting severe coronary artery disease. By setting probability thresholds for severe disease of <20% and >40% for the three prediction equations, the agreement approach divided the test set into three groups: low risk (patients with all three equations predicting <21% probability of severe coronary disease), no agreement, and high risk (all three equations with >39% probability) for severe coronary artery disease. Because the patients in the no agreement group would be sent for further testing and would eventually be correctly classified, the sensitivity of the agreement approach was 89% and the specificity was 96%. The agreement approach appeared to be unaffected by disease prevalence, missing data, variable definitions, or even angiographic criteria. CONCLUSIONS: Requiring diagnosis of severe coronary disease to be dependent on agreement between these three equations has made them likely to function in all clinical populations. The agreement approach should be an efficient method for the evaluation of populations with varying prevalence of coronary artery disease, limiting the use of more expensive noninvasive and invasive testing to patients with a higher probability of left main or triple-vessel coronary artery disease. This approach provides a strategy that can be applied by inputting the results of basic clinical assessment into a programmable calculator or a computer to assist the practitioner in deciding when further evaluation is appropriate, thus assuring patients access to subspecialty care.     

Antagonistic effect of coryneform bacteria from red smear cheese against Listeria species

A total of 187 coryneform bacteria were isolated from red smear and screened for inhibitory effects against 16 strains of Listeria species. Culture filtrates from Brevibacterium linens (16 strains), Arthrobacter nicotianae (4 strains) and Arthrobacter nucleogenes (3 strains) showed clear zones of inhibition. The antagonistic effect was seen against 26 to 87% of 91 Listeria strains tested. A. nicotianae and A. nucleogenes were more effective against Listeria innocua and Listeria ivanovii than against Listeria monocytogenes. No species specifically was observed for B. linens, but there was a difference regarding the inhibitory activity of individual culture filtrates. When culture filtrates of the test strains were added to Listeria broth cultures, the maximum growth level was not attained. Inhibition in broth cultures was dependent on the concentration of culture filtrates. Culture filtrates from the late stationary phase had a stronger inhibitory effect on the growth of L. monocytogenes. The nature of the inhibitory effects remained unclear. Attempts to characterize the nature of the antagonism showed that the culture filtrates lost their inhibitory activity upon heating, and the molecular size of the inhibitory substances were greater than 12-14 kDa.     

Potential New Matrix Alloys for production of PM Aluminium Foams

The powder compact melting technique for aluminium foam production as practised today accepts a certain mismatch between foaming agent decomposition and matrix alloy melting temperatures. This mismatch is believed to influence the pore structure in an unfavourable way. Adjustment of TiH₂ decomposition as well as liquidus and solidus temperatures of matrix alloys can be used to counteract it. Effects of TiH₂ thermal treatments are investigated using thermal analysis. TiH₂ variants gained via annealing treatments were used to produce aluminium foam precursor materials. As matrix for these specimens, aluminium based alloys with low liquidus and solidus temperatures were selected. Alloy systems considered include established combinations of aluminium with Cu, Mg, Si and Zn as well as special quaternary mixtures of these elements. First examinations presented include thermal analysis of alloys as well as studies on expansion vs. time and temperature relationships of precursor material based on new alloys and foaming agent variants.     

Qualitätssicherung von Chemie-Email. Vergleich verschiedener Analysenverfahren

Quality Assurance for Vitreous and Porcelain Enamels: Comparison of Analysis Methods Enamelled test specimens and technical parts made by West European manufacturers of chemical apparatus were investigated by ESCA, RFA, RMA and ICP for qualitative and quantiative differences of enamel composition. It was found that for reliable information concerning the identity and quantitative composition of an enamel it is necessary to use a combination of energy-dispersive X-ray microanalysis (EDX) with optical spectral analysis (ICP).     

Problems of immuno- and mesenchyma-suppressive therapy of inflammatory liver diseases

We have studied maximal oxygen uptake, maximal heart rate, maximal exercise ventilation and the ventilatory response to exercise in 24 male and 14 female Scottish athletes. The values for maximal oxygen uptake are similar to those reported in other international studies. In eight athletes repeat measurements of maximal oxygen uptake 7-11 months after the initial study showed no change from the initial values. The values for the ventilatory response to exercise in our athletes were normal. The relationship is discussed between maximal oxygen uptake and ventilatory responses to exercise, hypoxia and hypercapnia and it is suggested that these may be related to athletic event.