SERS of cylindrospermopsin cyanotoxin: Prospects for quantitative analysis in solution and in fish tissue.

Cylindrospermopsin (CYN), a cyanotoxin occurring in environmental waters as a cyanobacteria metabolite, has recently raised increased interest both in the scientific community and the environmental, food control and health care bodies due to the incidence of poisoning reports and the lack of prompt, effective detection and monitoring techniques. Here we report comprehensive Raman and SERS spectroscopy data on CYN cyanotoxin and provide a detailed characterization of the vibrational Raman signal based on DFT calculation as well as the adsorption properties with respect to the silver nanoparticles surface. Quantitative SERS analysis was achieved for concentrations range from 0.218 nM to 2.18 µM in aqueous solution. We further investigated the SERS discrimination of artificially intoxicated fish tissue from normal one, using linear discriminant analysis. Significant changes in SERS signal of toxic tissue compared to normal one allowed clear and fast differentiation of toxic tissue with 100% specificity/sensitivity. The cross-validation procedure provided 100% clear separation based on the SERS data. The results open reliable perspectives for SERS monitoring the environmental water bodies.

Assessment of cerebral tissue oxygen saturation in septic patients during acetazolamide provocation - a near infrared spectroscopy study.

UNLABELLED: Sepsis-associated encephalopathy is a multifactorially determined process of the brain parenchyma. Among other factors, vasogenic causes have been shown to play a role in its development. The aim of the present work was to assess whether cerebral tissue oxygen saturation is influenced by administration of acetazolamide in septic patients compared to controls. PATIENTS AND METHODS: 15 patients with severe sepsis and 10 healthy controls were studied. Cerebral oxygen saturation was assessed by INVOS 51 OOC Cerebral Oxymeter (NIRS) before and after administration of 15 mg/kg BW acetazolamide in both groups. RESULTS: The maximal rise that has been found in the partial pressure of CO(2) in the arterial blood of septic patients after administration of acetazolamide was from 35 ± 5 mmHg to 41.1 ± 6.3 mmHg. For the partial pressure of O(2) the observed increase was from 123.7 ± 47.1 mmHg to 139.9 ± 49 mmHg. Vasodilatory stimulus resulted in a similar maximal increase in cerebral oxygen saturation in septic patients and in controls (8.9 ± 6.5% for septic patients and 9.2 ± 4.6% for healthy persons, respectively). CONCLUSIONS: Cerebral vasoreactivity to acetazolamide is preserved in patients with severe sepsis.

Comparison of two depth of anaesthesia monitors during general anaesthesia: electrophysiological and clinical assessment.

UNLABELLED: Cerebral state monitor (CSM) is a recently developed anaesthesia depth monitor based on EEG measurement. Medline search confirmed that the accuracy of this monitor has already been compared with BIS monitoring; however, we did not find any studies comparing CSM monitor with AEP monitoring. Therefore, the aim of our study was to investigate the correlation between AAI using AEP monitor and CSI (cerebral state index) using CSM monitor. METHODS: Prospective, observational study involving 39 ASA I-III patients undergoing lumbar discuss hernia operation. Simultaneous registration of CSI and AAI was performed during general anaesthesia. The identical values were off-line analysed. Additionally in 20 patients parallel registration of CSI and AAI was undertaken while anaesthesia was guided based on routine clinical signs. RESULTS: While analysing the data in the superficial, ideal and deep anaesthesia zones, we found that a relationship between CSI and AAI is weak. Our patients spent roughly the half of the clinical anaesthesia in the ideal zone based on the AAI index and less than 50% based on CSI. Almost one fifth of clinical anaesthesia based on AAI and nearly 40% based on CSI was spent in the deep anaesthesia zones. A superficial anaesthesia has been detected in 27% of time based on AAI and 17% based on CSI. CONCLUSIONS: CSI and AAI weakly correlated to each other. Depth of anaesthesia monitors may be useful in detecting patients who spend valuable time within the deep anaesthetic zone.