Clostridium difficile in the ICU

Clostridium difficile has become an increasingly common infectious agent in the healthcare setting. It is generally associated with antibiotic use and causes diarrhea as well as other complications such as pseudomembranous colitis (PMC) and toxic megacolon. This organism poses a serious threat to patients in the intensive care unit (ICU) as it increases hospital length of stay, morbidity, and mortality. Recurrence rates are typically higher in the ICU population as those patients usually have immunocompromised systems, more exposure to antibiotics and proton pump inhibitors, loss of normal nutritional balance, and alterations in their colonic flora. Emergence of more virulent and pathogenic strains has made combating the infection even more difficult. Newer therapies, chemotherapeutic agents, and vaccinations are on the horizon. However, the most effective treatments to date are ceasing the inciting agent, reduction in the use of proton pump inhibitors, and prevention of the disease. In this chapter, we will explore the risk factors, diagnosis, treatment, and prevention of C. difficile infections (CDI) in the ICU

Measurement of Hepatic Protein Fractional Synthetic Rate with Stable Isotope Labeling Technique in Thapsigargin Stressed HepG2 Cells

Severe burn-induced liver damage and dysfunction is associated with endoplasmic reticulum (ER) stress. ER stress has been shown to regulate global protein synthesis. In the current study, we induced ER stress in vitro and estimated the effect of ER stress on hepatic protein synthesis. The aim was two-fold: (1) to establish an in vitro model to isotopically measure hepatic protein synthesis and (2) to evaluate protein fractional synthetic rate (FSR) in response to ER stress. Human hepatocellular carcinoma cells (HepG2) were cultured in medium supplemented with stable isotopes 1,2-13C2-glycine and L-[ring-13C6]phenylalanine. ER stress was induced by exposing the cells to 100 nM of thapsigargin (TG). Cell content was collected from day 0 to 14. Alterations in cytosolic calcium were measured by calcium imaging and ER stress markers were confirmed by Western blotting. The precursor and product enrichments were detected by GC-MS analysis for FSR calculation. We found that the hepatic protein FSR were 0.97±0.02 and 0.99±0.05%/hr calculated from 1,2-13C2-glycine and L-[ring-13C6]phenylalanine, respectively. TG depleted ER calcium stores and induced ER stress by upregulating p-IRE-1 and Bip. FSR dramatically decreased to 0.68±0.03 and 0.60±0.06%/hr in the TG treatment group (p<0.05, vs. control). TG-induced ER stress inhibited hepatic protein synthesis. The stable isotope tracer incorporation technique is a useful method for studying the effects of ER stress on hepatic protein synthesis

Transpulmonary thermodilution for hemodynamic measurements in severely burned children

Abstract Introduction Monitoring of hemodynamic and volumetric parameters after severe burns is of critical importance. Pulmonary artery catheters, however, have been associated with many risks. Our aim was to show the feasibility of continuous monitoring with minimally invasive transpulmonary thermodilution (TPTD) in severely burned pediatric patients. Methods This prospective cohort study was conducted in patients with severe burns over 40% of the total body surface area (TBSA) who were admitted to the hospital within 96 hours after sustaining the injury. TPTD measurements were performed using the PiCCO system (Pulsion Medical Systems, Munich, Germany). Cardiac Index (CI), Intrathoracic Blood Volume Index (ITBVI) (Stewart-Hamilton equation), Extravascular Lung Water Index (EVLWI) and Systemic Vascular Resistance Index (SVRI) measurements were recorded twice daily. Statistical analysis was performed using one-way repeated measures analysis of variance with the post hoc Bonferroni test for intra- and intergroup comparisons. Results Seventy-nine patients with a mean age (±SD) of 9 ± 5 years and a mean TBSA burn (±SD) of 64% ± 20% were studied. CI significantly increased compared to level at admission and was highest 3 weeks postburn. ITBVI increased significantly starting at 8 days postburn. SVRI continuously decreased early in the perioperative burn period. EVLWI increased significantly starting at 9 days postburn. Young children (0 to 5 years old) had a significantly increased EVLWI and decreased ITBVI compared to older children (12 to 18 years old). EVLWI was significantly higher in patients who did not survive burn injury. Conclusions Continuous PiCCO measurements were performed for the first time in a large cohort of severely burned pediatric patients. The results suggest that hyperdynamic circulation begins within the first week after burn injury and continues throughout the entire intensive care unit stay

The evaluation and specification development of alternate modified asphalt binders in South Carolina : final report.

SPR 703In this research project, asphalt binders containing various polymer modifiers were investigated throughexamining both binder and mixture properties.\ua0\ua0Two additional topics were also investigated, including: a) theeffects of liquid anti\u2010strip additives on asphalt mixtures; and b) the effects of natural sands in asphalt mixtures.\ua0\ua0The asphalt binder modifiers in this project included: two plastomers; an elastomer; PPA+SBS; terminallyblended ground tire rubber (GTR) binder; and a lab\u2010prepared GTR binder.\ua0\ua0The binder properties of 16 bindercombinations were obtained (e.g., viscosity, DSR, etc.) and compared.\ua0\ua0In addition, these modified binders wereused in mixtures with two aggregate sources, three anti\u2010strip additives, and varying RAP contents.\ua0\ua0There were32 different Superpave mix designs conducted for this project.\ua0\ua0Many engineering properties of the mixtureswere obtained, including: indirect tensile strength, tensile strength retained, rutting, and AMPT values.\ua0\ua0TheAMPT testing was conducted at different temperatures and frequencies.\ua0\ua0The results indicated that, in general,many of the alternate modified binders could be utilized in South Carolina hot mix asphalt (HMA) mixtures.\ua0\ua0Theresults also indicated that RAP and natural sand could be utilized, in limited quantities, in many mixtures usedon South Carolina secondary roads.\ua0\ua0In addition, the mixtures made with liquid anti\u2010strip additives in this projectin many cases produced moisture susceptibility values (e.g., ITS, TSR) that were compatible with those obtainedwith mixtures containing hydrated lime