Catalytic Decomposition of Peroxynitrite and Superoxide by Nafion Films Modified with Iron and Manganese Porphyrin

Nafion films alone and modified with inert electrolytes and metalloporphyrins were tested in their effectiveness of decomposition of aqueous peroxynitrite (PN) and superoxide. Films that were modified with a cationic manganese porphyrin, which has been shown to be responsible for catalytic decomposition of superoxide ion, were found to be most effective. Peroxynitrite was generated in solution by the decomposition of 3-morpholinosydnonimime (SIN-1) that generates nitric oxide and superoxide ion, which rapidly combine to form peroxynitrite. The tyrosine analogue 4-hydroxyphenylacetic (4-HPA) was used to trap the PN in pH 7.00 PBS buffer and was its nitrated product was detected by observing the change in visible absorbance at pH 10. The Nafion films modified with manganese porphyrin were active in superoxide quenching and the therefore blocking of peroxynitrite formation throughout a five week testing period. These experiments offer new strategies for disrupting superoxide and peroxynitrite in vivo

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Potential Drivers for the Re-Emergence of Canine Leptospirosis in the United States and Canada

Canine leptospirosis is an important zoonotic disease in many countries. This review examines potential drivers for increased diagnoses of canine leptospirosis in the United States and Canada, using the epidemiologic triad of agent-environment-host as a template. Leptospira spp. are classified into more than 250 serovars, but in many laboratories only 6 are routinely tested for in serologic agglutination tests of canine sera. Leptospiral infections in dogs may potentially go undetected with unemployed or currently employed diagnostic methods. Disease transmission from infected reservoir hosts usually occurs via urine-contaminated environmental sources such as water. Direct contact between infected and susceptible individuals, environmental factors such as climate changes in temperature and/or rainfall, and increasing number and urbanization of reservoir hosts may greatly increase dog exposure risks. A dog’s lifestyle may influence exposure risk to leptospirosis, but vaccination based on proper identification of circulating serogroups dramatically reduces post-exposure infections. Regrettably, resistance to vaccination by veterinarians and dog owners leaves a large number of dogs at risk for this zoonotic disease

Investigation of spatio‐temporal clusters of positive leptospirosis polymerase chain reaction test results in dogs in the United States, 2009 to 2016

Abstract Background Leptospirosis is a zoonotic disease of concern and an investigation of recent spatio‐temporal trends of leptospirosis in dogs in the United States is needed. Leptospira PCR testing has become increasingly used in veterinary clinical medicine and these data might provide information on recent trends of disease occurrence. Objectives To identify and describe clusters of PCR‐positive Leptospira test results in dogs in the United States. Animals Leptospira real‐time PCR test results from dogs (n = 40 118) in the United States from IDEXX Laboratories, Inc., between 2009 and 2016 were included in the analysis. Methods In this retrospective study, spatio‐temporal clusters for a real‐time PCR‐positive test were identified using the space‐time permutation scan statistic and the centroid of the zip code reported for each test. A maximum spatial window of 20% of the population at risk, and a maximum temporal window of 6 months were used. Results Seven statistically significant space‐time clusters of Leptospira real‐time PCR‐positive test results were identified across the United States: 1 each located within the states of Arizona (2016), California (2014‐2015), Florida (2010), South Carolina (2015), and 1 each located within the south‐central region (2015), midwest region (2014), and northeast region (2011). Clusters ranged from 3 to 108 dogs and were identified during all years under study, except 2009, 2012, and 2013. Conclusions and Clinical Importance The spatial and temporal components of leptospirosis in dogs in this study are similar to those in previous work. However, clusters were identified in new areas, demonstrating the complex epidemiology of this disease

Development of inert density mock materials for HMX

<p>Inert surrogates or mocks for high explosives are commonly used in place of the real material for complex experiments or in situations where safety is a concern. Here, several materials were tested as potential mocks for HMX in terms of density, thermal stability, and processability. Selection criteria were developed and a literature search was conducted primarily using the Cambridge Structural Database. Out of over 200 potentially acceptable materials, six were chosen for crystallization experiments and a suite of analytical characterization. Of these six, 5-iodo-2ˊ-deoxyuridine, <i>N,N</i>ˊ-bis(2,3,4,5,6-pentafluorophenyl)oxamide, and 2,3,4,5,6-pentafluorobenzamide all were found to be thermally stable at 150°C, matched HMX density as a pressed pellet, and could be crystallized to appropriate particle sizes. These three materials are considered suitable inert density mocks for HMX and will be the subject of future testing.</p