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Introduction: Setting the Stage I. The Governance Crisis in Context A. Setting the Stage: Land and People of the Mountains B. The North Caucasus Federal District: Adding Fuel to a [...]

Objectives. Recurrent hypoxemia has been proposed as an important pathophysiological mechanism underlying sudden infant death syndrome (SIDS). However, conflicting results emerged when xanthines were used as markers for hypoxia. The vascular endothelial growth factor (VEGF) gene is highly sensitive to changes in tissue partial oxygen tension, and changes in genomic and protein expression occur even after changes in oxygenation within the physiologic range. Methods. For determining whether hypoxia precedes SIDS, VEGF levels were measured using an enzyme-linked immunosorbent assay in the cerebrospinal fluid (CSF) of 51 SIDS infants and in 33 additional control infants who died of an identifiable cause. In addition, 6 rats that had a chronically implanted catheter in the lateral ventricle were exposed to a short hypoxic challenge, and VEGF concentrations were measured in CSF at various time points for 24 hours. Another set of 6 rats were killed with a pentobarbital overdose, and VEGF CSF levels were obtained at different time points after death. Results. Mean VEGF concentrations in CSF were 308.2 [+ or -] 299.1 pg/dL in the SIDS group and 85.1 [+ or -] 82.9 pg/dL in those who died of known causes. Mean post-mortem delay averaged 22 hours for both groups. In rat experiments, hypoxic exposures induced time-dependent increases in VEGF, peaking at 12 hours and returning to baseline at 24 hours. Postmortem duration in the animals was associated with gradual increases in VEGF that reached significance only at 36 hours. Conclusions. We conclude that VEGF CSF concentrations are significantly higher in infants who die of SIDS. We postulate that hypoxia is a frequent event that precedes the sudden and unexpected death of these infants. Pediatrics 2003;111:358-363; hypoxia, sudden infant death syndrome, vascular endothelial growth factor., ABBREVIATIONS. SIDS, sudden infant death syndrome; VEGF, vascular endothelial growth factor; CSF, cerebrospinal fluid; SD, standard deviation. In recent years, the incidence of sudden infant death syndrome (SIDS) has decreased [...]

Lung epithelial cells were cultured with polymorphonuclear neutrophils (PMNs) with greater than normal levels of superoxide to find out if cystic fibrosis and acute respiratory distress syndrome lungs have higher amounts of nitrate or peroxynitrate. Murine LA-4 epithelial cell lines were incubated in Ham's F-12 medium with 10% fetal calf serum, L-glutamine and penicillin-streptomycin until confluent. Results show that when PMNs were stimulated to produce superoxide, the level of nitric oxide went down. There was also an increase in nitrate but nitrite values remained the same.

Membranes used for water treatment are subject to organic fouling, caused by organic matter in source water. Characterizing organic matter has the potential to improve fouling prediction since the development of an organic fouling layer on the membrane is dependent on the specific characteristics of the organic matter. A field study was performed at a full‐scale reverse osmosis water treatment plant that treats secondary wastewater effluent for industrial reuse at a power plant. Samples were collected at various points within the treatment process and were analyzed for turbidity, total organic carbon (TOC), conductivity, and fluorescence Excitation Emission Matrices (EEM). Parallel factor analysis (PARAFAC) was used to generate representative fluorescence measurements of the organic matter. Results indicate that TOC and fluorescence measurements were effective in differentiating between two observed fouling periods at multiple locations within the treatment plant. However, none of the water quality measurements were effective in tracking treatability of organic matter throughout pretreatment. The results of this case study provide important information about the relationship between fluorescence NOM signals and membrane fouling that can be used in future online detection systems. Practitioner points: TOC and fluorescence measurements were effective in differentiating between the high fouling and low fouling periods.Water quality measurements were not effective in tracking changes in organic matter throughout pretreatment.Implementation of online fluorescence monitoring of fouling potential could be used for real‐time process control. [ABSTRACT FROM AUTHOR]