Red Blood Cell Stability in Uremic Rats

Determining the fragility of the red blood cell (RBC) is important for the diagnosis of and evaluation for treatment of several RBC diseases. In part RBC production is controlled through the hormone erythropoietin secreted by the kidney. In a previous study from this laboratory, it was found that RBC were more stable in uremic male rats compared to controls. In this experiment, uremia was induced in four groups of female rats through a two stage nephrectomy. The nephrectomy involved the removal of two-thirds of the left kidney, followed by the removal of the entire right kidney one week later. The animals were divided into three groups; NX-(5/6 nephrectomy), SH-(sham surgery), and PF-(sham surgery, but were fed the same food weight as the NX animals). The samples obtained in Trial I and Trial II were divided into two categories; initial and final. The initial samples were collected 14 days after the sham and five- sixth nephrectomy surgeries. The final sample were collected at the time of sacrifice. The samples obtained in Trial 11 consisted only of initial samples, taken fourteen days after the five-sixth nephrectomy and sham surgeries were completed. The samples in Trial IV were final samples, obtained at the time of sacrifice. Decreasing hypotonic %NaCl solutions were used to determine the hemolysis of RBC from the rats. RBC hemolysis was determined spectrophotometrically by monitoring hemoglobin absorbance at 540nm in the supernatant fluid. Analytic precision experiments using multiple assays of the same blood sample for 50% RBC hemolysis showed a coefficient of variation of only 1.1%. Analysis of the %NaCl at 50% RBC hemolysis did not differ significantly between the three groups of animals suggesting that although the NX animals were uremic, the RBC did not differ in stability to hypoosmotic shock. Future direction for this type of research will be extended to human studies where kidney failure patients (dialysis patients) can have both the age of the RBC and their fragility determined under therapy. The erythrocyte hemolysis peroxide test (HPT) was also performed on rat blood samples from Trial IV and on five human blood samples, in order to determine hemolysis in the RBC. A 2% H2O2 solution was used to determine RBC stability and %Hemolysis was calculated by dividing the value for hemolysis due to H2O2 by the 100% hemolysis value and multiplying by 100. Analysis of the %Hemolysis by HPT for each animal sample also showed no significant difference between the three subgroups of animals. Future direction for this type of research will be extended to include all four trials of animals as well as human studies involving patients with kidney failure (dialysis patients)

New technologies to prevent intravascular catheter-related bloodstream infections.

Most intravascular catheter-related infections are associated with central venous catheters. Technologic advances shown to reduce the risk for these infections include a catheter hub containing an iodinated alcohol solution, short-term chlorhexidine-silver sulfadiazine- impregnated catheters, minocycline-rifampin-impregnated catheters, and chlorhexidine- impregnated sponge dressings. Nontechnologic strategies for reducing risk include maximal barrier precautions during catheter insertion, specialized nursing teams, continuing quality improvement programs, and tunneling of short-term internal jugular catheters

In Vitro Activities of Telavancin and Vancomycin against Biofilm-Producing Staphylococcus aureus, S. epidermidis, and Enterococcus faecalis Strains

We investigated the activities of telavancin and vancomycin against biofilm-producing Staphylococcus and Enterococcus strains. At clinically attainable concentrations, telavancin was active against bacteria embedded in biofilm (minimal biofilm eradication concentration [MBEC], 0.125 to 2 μg/ml) and inhibited biofilm formation at concentrations below the MIC. Vancomycin did not demonstrate the same activity (MBEC, ≥512 μg/ml) against Staphylococcus aureus and Enterococcus faecalis. Telavancin may have a unique role in biofilm-associated infections

Comparison of Telavancin and Vancomycin Antibiotic Lock Solutions in the Eradication of Biofilm-Producing Staphylococci and Enterococci from Central Venous Catheters

Purpose: Results of a study of the activity of antibiotic lock solutions of vancomycin and telavancin against biofilm-forming strains of Staphylococcus epidermidis, Enterococcus faecalis, and Staphylococcus aureus are reported. Methods: An established in vitro central venous catheter model was used to evaluate lock solutions containing vancomycin (5 mg/mL) or telavancin (5 mg/mL), with and without preservative-containing heparin sodium (with 0.45% benzyl alcohol) 2500 units/mL, heparin, and 0.9% sodium chloride solution. Lock solutions were introduced after 24-hour bacterial growth in catheters incubated at 35 °C. After 72 hours of exposure to the lock solutions, catheters were drained, flushed, and cut into segments for quantification of colony-forming units. Results: Against S. epidermidis, vancomycin and telavancin (with or without heparin) had similar activity. Against E. faecalis, vancomycin alone was more active than telavancin alone (p \u3c 0.01). Against S. aureus, vancomycin plus heparin had activity than telavancin (p \u3c 0.02). The addition of heparin was associated with reduced activity of the vancomycin lock solution against S. epidermidis and E. faecalis (p \u3c 0.01). Telavancin activity was not significantly changed with the addition of heparin. Conclusion: In a central venous catheter model, vancomycin and telavancin activity was similar in reducing biofilm-producing S. epidermidis. However, vancomycin was more active than telavancin against E. faecalis and S. aureus. None of the tested agents eradicated biofilm-forming strains. The addition of preservative-containing heparin sodium 2500 units/mL to vancomycin was associated with reduced activity against S. epidermidis and E. faecalis

The End of the State of Autonomies? An Analysis of the Controversy Surrounding the 2010 Spanish Constitutional Court Ruling on Catalonia\u27s 2006 Statute of Autonomy

In recent years, many citizens in the Spanish region of Catalonia have mobilized in favor of independence, a desire previously far outside the mainstream. As of the spring of 2016, separatists control the majority of seats in Catalan parliament. This study seeks to explain why independence is so widely supported in Catalonia, and focuses specifically on the region’s 2006 Statute of Autonomy, which the Spanish Constitutional Court modified in a 2010 ruling. The struggles that the statute faced both before and after the court’s 2010 ruling provided a crucial turning point in the debate over Catalan independence. The political rhetoric and media reactions surrounding the court’s ruling serve as manifestations of longstanding conflicts within Spanish society and, in doing so, frame the larger issue of Catalan separatism. So, the controversy surrounding Catalonia’s 2006 Statute of Autonomy provides a useful case study for understanding the ideological disputes within Spain that allowed for the current situation

Ethanol and Isopropyl Alcohol Exposure Increases Biofilm Formation in Staphylococcus aureus and Staphylococcus epidermidis

Introduction Alcohols, including ethanol and isopropyl alcohol, are used in clinical practice for disinfection and infection prevention. Recent studies, however, demonstrate that alcohols may enhance biofilm production in Staphylococci. Methods We quantified biofilm formation in the presence of ethanol and isopropyl alcohol in six different, well-characterized strains of Staphylococcus epidermidis and Staphylococcus aureus. After 24 h of biofilm development, each strain was exposed to normal saline (NS), ethanol, or isopropyl alcohol (40%, 60%, 80% and 95%) for additional 24 h incubation. Adherent biofilms were stained and optical density was determined. Viability of strains was also determined after alcohol exposure. Results Ethanol increased biofilm formation in all six strains compared to normal saline (p \u3c 0.05). There was increased biofilm formation with increasing ethanol concentration. Isopropyl alcohol also increased biofilm formation with increasing alcohol concentration in all six strains (p \u3c 0.01 vs NS). The slime-negative, chemical mutant strain of S. epidermidis increased biofilm formation after exposure to both alcohols, likely reverting back its primary phenotype through modulation of the intercellular adhesin repressor. All strains demonstrated viability after exposure to each alcohol concentration, though viability was decreased. Conclusion Ethanol and isopropyl alcohol exposure increases biofilm formation of S. aureus and S. epidermidis at concentrations used in clinical settings. Ethanol and isopropyl alcohol did not eradicate viable Staphylococci from formed biofilm

Antibiotic Resistance Rates for Pseudomonas aeruginosa Clinical Respiratory and Bloodstream Isolates Among the Veterans Affairs Healthcare System from 2009 to 2013

Pseudomonas aeruginosa is a major cause of healthcare-associated infections and resistance among isolates is an increasing burden. The study purpose was to describe national resistance rates for clinical P. aeruginosa respiratory and bloodstream cultures and the prevalence of multidrug-resistant (MDR) P. aeruginosa within the Veterans Affairs (VA). MDR was defined as non-susceptibility to at least one drug in at least 3 of the following 5 categories: carbapenems, extended-spectrum cephalosporins, aminoglycosides, and piperacillin/tazobactam. We reviewed 24,562 P. aeruginosa respiratory and bloodstream isolates across 126 VA facilities between 2009 to 2013. Most isolates were collected from inpatient settings (82%). Resistance was highest in fluoroquinolones (33%) and exceeded 20% for all classes assessed (carbapenems, extended-spectrum cephalosporins, aminoglycosides, and piperacillin/tazobactam). Resistance was higher in inpatient settings and in respiratory isolates. Prevalence of MDR was 20% overall (22% for inpatient isolates, 11% outpatient, 21% respiratory, 17% bloodstream). Our findings are consistent with previous surveillance report