Treatment of Severe Sepsis: Where Next? Current and Future Treatment Approaches After the Introduction of Drotrecogin Alfa

Severely septic patients continue to experience excessive morbidity and mortality despite recent advances in critical care. Although significant resources have been invested in new treatments, almost all have failed to improve outcomes. An improved understanding of sepsis pathophysiology, including the complex interactions between inflammatory, coagulation, and fibrinolytic systems, has accelerated the development of novel treatments. Recombinant human activated protein C (rhAPC), or drotrecogin alfa (activated) (DAA), is currently the only US Food and Drug Administration (FDA)-approved medicine for the treatment of severe sepsis, and only in patients with a high risk of death. This review will discuss the treatment of severe sepsis, focusing on recent discoveries and unresolved questions about DAA's optimal use. Increasing pharmacological experience has generated enthusiasm for investigating medicines already approved for other indications as treatments for severe sepsis. Replacement doses of hydrocortisone and vasopressin may reduce mortality and improve hypotension, respectively, in a subgroup of patients with catecholamine-refractory septic shock. In addition to discussing these new indications, this review will detail the provocative preliminary data from four promising treatments, including two novel modalities: antagonizing high mobility group box protein and inhibiting tissue factor (TF). Observational data from the uncontrolled administration of heparin or statins in septic patients will also be reviewed

Young Stars with SALT

We present a spectroscopic and kinematic analysis of 79 nearby M dwarfs in 77 systems. All are low-proper-motion southern hemisphere objects and were identified in a nearby star survey with a demonstrated sensitivity to young stars. Using low-resolution optical spectroscopy from the Red Side Spectrograph (RSS) on the South African Large Telescope (SALT), we have determined radial velocities, H-alpha, Lithium 6708\AA, and Potassium 7699\AA~equivalent widths linked to age and activity, and spectral types for all our targets. Combined with astrometric information from literature sources, we identify 44 young stars. Eighteen are previously known members of moving groups within 100 parsecs of the Sun. Twelve are new members, including one member of the TW Hydra moving group, one member of the 32 Orionis moving group, nine members of Tucana-Horologium, one member of Argus, and two new members of AB Doradus. We also find fourteen young star systems that are not members of any known groups. The remaining 33 star systems do not appear to be young. This appears to be evidence of a new population of nearby young stars not related to the known nearby young moving groups.Comment: 23 pages, 11 figures, 6 tables. Accepted to Ap

Improving Biomethanation of Chicken Manure by Co-Digestion with Ethanol Plant Effluent

As the global production of chicken manure has steadily increased, its proper management has become a challenging issue. This study examined process effluent from a bioethanol plant as a co-substrate for efficient anaerobic digestion of chicken manure. An anaerobic continuous reactor was operated in mono- and co-digestion modes by adding increasing amounts of the ethanol plant effluent (0%, 10%, and 20% (v/v) of chicken manure). Methanogenic performance improved significantly in terms of both methane production rate and yield (by up to 66% and 36%, respectively), with an increase in organic loading rate over the experimental phases. Correspondingly, the specific methanogenic activity was significantly higher in the co-digestion sludge than in the mono-digestion sludge. The reactor did not suffer any apparent process imbalance, ammonia inhibition, or nutrient limitation throughout the experiment, with the removal of volatile solids being stably maintained (56.3???58.9%). The amount of ethanol plant effluent appears to directly affect the rate of acidification, and its addition at ???20% (v/v) to chicken manure needs to be avoided to maintain a stable pH. The overall results suggest that anerobic co-digestion with ethanol plant effluent may provide a practical means for the stable treatment and valorization of chicken manure

Economic impact of soybean aphid

Since its introduction to Iowa in 2000, the soybean aphid has firmly established itself as a pest of soybean. In 2003, the largest infestations of this pest occurred in Iowa. Current research is examining accurate sampling methods, refining economic thresholds, and providing farmers with effective management options. In addition, research has been conducted to determine the economic impact of this insect pest, especially during an outbreak year

Mobility and Degradation of Pesticides and Their Degradates in Intact Soil Columns

Laboratory studies were conducted to determine the mobility of parent pesticides and degradation products through the use of large undisturbed soil columns. The influence of vegetation on the mobility of pesticide adjuvants was also investigated. Modifications to the laboratory setup of soil columns for studying various pesticides, degradation products, and adjuvants were done to fit the needs of the particular compound being studied. To improve mass balances of volatile parent compounds, such as methyl bromide, as well as biodegradable (mineralizable) pesticide degradation products such as deethylatrazine, modifications of columns to accommodate isolation of volatile degradation products were accomplished by enclosure of the column head space and use of flow-through systems. Evidence of preferential flow of atrazine, deethylatrazine, metolachlor, and methyl bromide were indicated by the presence of either the 14C-compound or Br-(in the case of methyl bromideapplied soil columns) after the first leaching event. Diffusion through the soil matrix was also evident with a peak of14C in the leachate several weeks after pesticide (or degradate) application to the soil column. Deethylatrazine, a major degradate of atrazine, was more mobile than the parent compound. Vegetation had a significant positive effect on reducing the mobility of the adjuvants propylene glycol and ethylene glycol

Effect of Sediment on the Fate of Metolachlor and Atrazine in Surface Water

In aquatic environments, pesticides can partition between the dissolved phase and particulate phase depending on the type of suspended sediment present and the physical and chemical properties of the pesticides and water. Particulate matter and sediment can alter the bioavailability of contaminants to organisms and therefore influence their toxicity and availability for microbial degradation. Experiments were conducted to determine the degradation of atrazine (6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine) and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(methooxyprop-2-yl)acetamide) in surface water, and to evaluate the contribution of sediment to their dissipation. Sediment significantly reduced concentrations of atrazine and metolachlor in the surface water as a result of greater degradation, evident by increased quantities of degradates in the surface water, and the partitioning of the herbicide or herbicide degradates in the sediment. First-order 50% dissipation time (DT50) values for atrazine and metolachlor were 42 and 8 d in the surface water-sediment incubation systems, which were almost four times less than the DT50s calculated for the sediment-free systems. The results of this research illustrate the importance of sediment in the fate of pesticides in surface water. Greater comprehension of the role of sediment to sequester or influence degradation of agrichemicals in aquatic systems will provide a better understanding of the bioavailability and potential toxicity of these contaminants to aquatic organisms

Fate of Methyl Bromide in Fumigated Soils

Recent controversy over the potential role of methyl bromide (MeBr) in damaging the ozone layer has spurred interest in increasing our understanding of the transformation and movement of this fumigant after it is applied to soil. Our research indicates MeBr is rapidly volatilized from fumigated soil (within the first 24 hours) and volatility significantly increases with temperature (35° C \u3e 25° C = 15° C) and moisture (0.03 bar \u3e 0.3 bar \u3e 1 bar \u3e 3 bar). Degradation of MeBr, measured by production of bromide ion (Br-), was also directly related to temperature and moisture. Undisturbed soil column studies indicated that MeBr rapidly volatilized (\u3e 50% of the MeBr flux occurred in 48 h) but did not leach into subsurface soil. Residual MeBr was degraded in the soil column, evident by the high concentrations of Br- in the leachate water. In field studies, MeBr also volatilized rapidly from soil, but a significant portion of the MeBr was degraded (30% after 2 d). These studies provide pertinent information for assessing the fate of MeBr in soil, which should lead to more informed decisions regulating its use