Water assessment using ultra-weak bioluminescence.

In this paper a method to evaluate the presence of microorganisms of the coliform group in water samples using the ultra-weak bioluminescence (UWB) is proposed. A series of UWB measurements and optical density measurements from cultures of both a set of standard E. coli strain samples, and a set of water samples from a river near Curitiba City in Brazil were performed. All samples were previously incubated at 37°C for 11h in nutritive medium before the temporal UWB emission profiles data were acquired for a period of 24h inside a dark chamber of an especially implemented instrumentation capable of doing photon counting measurements. For the optical density measurements, a spectrophotometer was used to acquire the growth kinetics of those cultures for a period of 13h, and the results compared to the UWB profiles. Periodic time-components analysis of the UWB data from both the set of standard E. coli samples and the set of the river's water samples were performed and compared to each other. The results have shown that the UWB temporal profiles resemble in some way the growth kinetics curve and the periodic time-components analysis is an effective way to discriminate between contaminated and non-contaminated samples, therefore the method may be viable for detecting coliforms in water samples in less time than usual methods.

Measurement of composite shrinkage using a fibre optic Bragg grating sensor.

Fibre Bragg grating is used to determine resin-based composite shrinkage. Two composite resins (Freedom from SDI and Z100 from 3M) were tested to determine the polymerization contraction behaviour. Each sample of resin was prepared with an embedded fibre Bragg grating. A LED activation unit with wavelength from 430 nm to 470 nm (Dabi Atlante) was used for resin polymerization. The wavelength position of the peak in the optical reflection spectra of the sensor was measured. The wavelength shift was related to the shrinkage deformation of the samples. Temperature and strain evolution during the curing phase of the material was monitored. The shrinkage in the longitudinal direction was 0.15 +/- 0.02% for resin Z100 (3M) and 0.06+/-0.01% for Freedom (SDI); two-thirds of shrinkage occurred after the first 50 s of illumination.

Aortic stent grafting: a new approach to a deadly diagnosis: one hospital's findings in defining new care processes.

Ruptured abdominal aortic aneurysm (AAA) is the 13th leading cause of death in the United States. Diagnosis is the key to prevention of death from AAA. Millions of Americans harbor this silent, potentially lethal aneurysm. For over 50 years, conventional open surgical repair has been performed for ruptured aortic abdominal aneurysm. It is a major operation with an extended hospital stay and recovery period. An alternative approach to AAA repair has evolved over the past 10 years that combines advances in catheter and stent technologies. With the AAA aortic stent graft, patients usually do not require intensive care and are discharged home within 48 hours of the procedure. This article describes the AAA aortic stent graft procedure, in the formation of a case management team to develop a clinical pathway and standing orders for these patients and defines the outcomes of care.

Identification of retinolisomers by high-performance liquid chromatography not unequivocal up to now.

Former publications dealing with high-performance liquid chromatography (HPLC) of retinol provide inconsistent results and lack evidence for the identification of isomers. For clarification of the problems in this field, the isomeric structure of the major retinol isomers in crystallized form was proven by 1H-NMR, UV absorption spectroscopy and by X-ray analysis. These identified isomeric forms of retinol were separated by HPLC with different eluent mixtures and the chromatograms compared in detail with previously published data. A conclusive assignment for HPLC separation of retinol isomers is given.

[1H-NMR spectroscopic study of cysteamine eyedrops]. / 1H-NMR-spektroskopische Untersuchung von Cysteamin-Augentropfen.

BACKGROUND: The efficiency of cysteamine eye drops in the treatment of cystinosis has been demonstrated in several studies: Corneal cystine crystals can be removed by topical cysteamine. Cysteamie 0.5% eye drops were superior to a 0.1% solution. It is not clear how fast cysteamine is oxidized to cystamine under the influence of atmospheric oxygen. MATERIAL AND METHODS: Samples of a new bottled cysteamine 0.5% solution were analysed 1H-NMR-spectroscopically over a period of several weeks (AM 400/WB-NMR-instrument, Bruker/Karlsruhe; 400.15 MHz). Samples bottled in an argon atmosphere were compared to samples bottled without inert gas. Definite samples were opened four times a day (A). The remainder of the samples was stored closed (B). RESULTS: In sample A a 1:1 weight ratio between cysteamine and cystamine was reached after 38 days. In samples B cysteamine was not oxidized to cystamine. The initial amount of cystamine was something lower in samples with argon, but argon could not prevent the decrease of the cysteamine concentration in sample A. CONCLUSIONS: The preparation of cysteamine solution in an argon atmosphere is useful. One bottle can be used for about one week, if less than 10% of the oxidation product cystamine is accepted.

Lung surfactant phospholipids associate with polymerizing fibrin: loss of surface activity.

Intraalveolar fibrin formation is a hallmark of many acute and chronic lung inflammatory processes. We investigated the influence of fibrin polymerization on biochemical and biophysical properties of a calf lung surfactant extract (CLSE) used for therapy of neonatal distress syndrome. Thrombin-induced coagulation of human fibrinogen (range, 0.04 to 4 mg/ml) in the presence of CLSE (2 mg/ml phospholipids) resulted in progressive loss of surface tension-lowering properties and adsorption facilities of this surfactant preparation; the CLSE-inhibitory capacity of desAABB-fibrin surpassed that of fibrinogen by more than two orders of magnitude. In parallel with the loss of surface activity, association of the predominant surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) (14C-labeled, admixed to 2 mg/ml CLSE) with polymerizing desAABB-fibrin occurred. A volume of 0.3 mg/ml insoluble fibrin effected a approximately 50% loss, and 0.6 mg/ml a > 90% loss, of DPPC from the aqueous phase. Dioleoylphosphatidylcholine, dipalmitoylphosphatidic acid, stearic acid, palmitic acid, and arachidonic acid, admixed to CLSE as labeled compounds, as well as total CLSE phospholipids were retained in polymerizing desAABB-fibrin with dose-effect curves superimposable to that of DPPC; no fibrin association was noted for 14C-glycerol-3-phosphate. Polymerizing desAA-fibrin, generated by incubation of CLSE-fibrinogen mixtures with arvin, captured DPPC and resulted in loss of surface properties at even lower concentrations, compared with desAABB-fibrin. In contrast, CLSE incubation with preformed desAABB- and desAA-fibrin polymers did not cause substantial phospholipid coupling with the clot material or loss of surface properties. Microtiter plate-immobilized fibrinogen and desAABB- and desAA-fibrinomonomers did not bind CLSE phospholipids enriched with 14C-DPPC.(ABSTRACT TRUNCATED AT 250 WORDS)

Spin relaxation of iron in mixed state hemoproteins.

In hemoproteins the relaxation mechanism of iron is Orbach for high spin (HS) and Raman for low spin (LS). We found that in met-hemoglobin and met-myoglobin, under conditions in which the two spin states coexist, both the HS and the LS states relax to the lattice through Orbach-like processes. Alos, very short (approximately 1 ns) and temperature independent transverse relaxation times T2 were estimated. This may result from the unusual electronic structure of mixed states hemoproteins that allows thermal equilibrium and interconversion of the spin states.

High and low spin state mixture in methemoglobin and metmyoglobin.

The mixture of low and high iron spin states is studied by electron spin resonance in methemoglobin and in metmyoglobin between 6K and 100K. The crystals contain iron (Fe3) exclusively in the high spin state, while powdered samples show a mixture of high and low spin iron. We detected, for the first time, the low spin state in metmyoglobin at low temperatures. The ratio of high to low spin concentrations (k-1) varies exponentially with inverse of temperature in both proteins, only the absolute value is greater in myoglobin. The slope of K-1 depends on the cooling rate and on the temperature range. The results are qualitatively explained assuming a temperature dependent distribution of crystical field around the cristal value, delta c.

Quantification of extracorporeal fibrin deposits in haemodialysis with minimal and conventional heparinization.

The effects of minimal intermittent heparinization and of conventional heparinization on endogen fibrinogen concentration as well as on fibrin deposits were studied on 17 on patients hemodialysis. It was shown that the minimal intermittent heparinization did non reduce dialysis efficiency and that a total heparin dosage of 6,000 units is the lowest safe limit.

Paraffin oil pneumonia. Analysis of saturated hydrocarbons in different human tissue.

Temperature-programmed gas chromatographic analysis on columns packed with Apiezon L as stationary phase is shown to be the best method for the qualitative and quantitative analysis of simple and complex hydrocarbon mixtures when compared with all the other applicable techniques (thin-layer chromatography, column chromatography, ultraviolet spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry) described in this paper. Using the method in a patient with mineral oil pneumonia it could be demonstrated that he expectorated a maximum of 79.5 mg liquid paraffin daily and also transported equally complex saturated hydrocarbons in a concentration of 1.3 mg% in plasma and of 1.6 mg% in the cellular blood components. In an additional experiment the direct determination of liquid paraffin resorbed from the gastrointestinal tract was possible in a patient with a left chyle fistula in the neck. After a dose of 50 g liquid paraffin administered as a laxative, 246 ml chyle was collected within the following 14 h which yielded a total of 4.5 mg liquid paraffin. Its composition was identical with the administered laxative. Assuming a daily lymph volume of 1.51, the resorbed amount would correspond to a resorption rate of 0.5 (see article) liquid paraffin. The importance of these results as well as the diagnostic consequences arising from the described analytical technique are discussed in detail.