Comparative electrocardiographic, autonomic and systemic inflammatory responses to soy biodiesel and petroleum diesel emissions in rats

CONTEXT

Biodiesel fuel represents an alternative to high particulate matter (PM)-emitting petroleum-based diesel fuels, yet uncertainty remains regarding potential biodiesel combustion emission health impacts.

OBJECTIVE

The purpose of this study was to compare cardiovascular responses to pure and blended biodiesel fuel emissions relative to petroleum diesel exhaust (DE).

MATERIALS AND METHODS

Spontaneously hypertensive rats were exposed for 4 h per day for four days via whole body inhalation to combustion emissions (based on PM concentrations 50, 150 or 500 μg/m(3) or filtered air) from pure (B100) or blended (B20) soy biodiesel, or to pure petroleum DE (B0). Electrocardiogram (ECG) and heart rate variability (HRV, an index of autonomic balance) were monitored before, during and after exposure while pulmonary and systemic inflammation were assessed one day after the final exposure. ECG and HRV data and inflammatory data were statistically analyzed using a linear mixed model for repeated measures and an analysis of variance, respectively.

RESULTS

B100 and B0, but not B20, increased HRV during all exposure days at the highest concentration indicating increased parasympathetic tone. Electrocardiographic data were mixed. B100 and B0, but not B20, caused significant changes in one or more of the following: serum C-reactive protein, total protein, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol, and blood urea nitrogen (BUN) and plasma angiotensin converting enzyme (ACE) and fibrinogen.

DISCUSSION AND CONCLUSIONS

Although responses to emissions from all fuels were mixed and relatively mild, some findings point to a reduced cardiovascular impact of blended biodiesel fuel emissions.

Prevention of meticillin-resistant Staphylococcus aureus bloodstream infections in European hospitals: moving beyond policies

BACKGROUND

There is evidence that meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia can be reduced with improved infection control and antibiotic stewardship.

AIM

To survey infection control and antibiotic stewardship practices within European hospitals and to identify initiatives that correlate with reduced MRSA prevalence.

METHODS

Online questionnaires were sent to European hospitals about their surveillance, hand hygiene, intravenous device management, admission screening, isolation, antibiotic prescribing, hospital demographics and MRSA blood culture isolates during 2010.

FINDINGS

In all, 269 replies were received from hospitals in 29 European countries. Lower MRSA prevalence showed significant association with presence of incidence surveillance, performance of root cause analysis, mandatory training requirements for hand hygiene, accountability measures for persistent non-compliance, and multi-stakeholder teamwork in antibiotic prescribing. Presence of policies on intravenous catheter insertion and management showed no variation between different MRSA prevalence groups. However, low-prevalence hospitals reported more competency assessment programmes in insertion and maintenance of peripheral and central venous catheters. Hospitals from the UK and Ireland reported the highest uptake of infection control and antibiotic stewardship practices that were significantly associated with low MRSA prevalence, whereas Southern European hospitals exhibited the lowest. In multiple regression analysis, isolation of high-risk patients, performance of root cause analysis, obligatory training for nurses in hand hygiene, and undertaking joint ward rounds including microbiologists and infectious disease physicians remained significantly associated with lower MRSA prevalence.

CONCLUSION

Proactive infection control and antibiotic stewardship initiatives that instilled accountability, ownership, teamwork, and validated competence among healthcare workers were associated with improved MRSA outcomes.

Truth Be Told—Perspectives on Openness

In the field of oncology, [...]

Antimicrobial drug resistance patterns among cattle- and human-associated Salmonella strains

During the year 2004, 178 human and 158 bovine clinical Salmonella isolates were collected across New York State to better understand the transmission dynamics and genetic determinants of antimicrobial resistance among human and bovine hosts. Serotyping, sequence typing, and pulsed-field gel electrophoresis typing results have been reported previously. Here we tested all isolates for phenotypic susceptibility to 15 antimicrobial drugs that are part of the National Antimicrobial Monitoring System bovine susceptibility panel. PCR was performed on a representative subset of unique isolates (n = 53) to screen for the presence of 21 known antimicrobial resistance genes (i.e., ampC, blaTEM-1, blaCMY-2, blaPSE-1, cat1, cat2, cmlA, flo, aadA1, aadA2, aacC2, strA, strB, aphA1-IAB, dhrfI, dhrfXII, sulI, sulII, tetA, tetB, and tetG); selected fluoroquinolone- and nalidixic acid-resistant (n = 3) and -sensitive (n = 6) isolates were also tested for known resistance-conferring mutations in gyrA and parC. Genes responsible for antimicrobial resistance were shared among isolates of human and bovine origin. However, bovine isolates were significantly more likely than human isolates to be multidrug resistant (P < 0.0001; Fisher's exact test). Our analyses showed perfect categorical agreement between phenotypic and genotypic resistance for beta-lactam and chloramphenicol. Our data confirm that resistance profiles of amoxicillin-clavulanic acid, chloramphenicol, kanamycin, and tetracycline were strongly associated with the presence of blaCMY or ampC, flo, aphA1-IAB, and tetA, respectively. Our findings provide evidence for the clinical value of genotypic resistance typing if incorporating multiple known genes that can confer a phenotypic resistance profile.

The rpg4-mediated resistance to wheat stem rust (Puccinia graminis) in barley (Hordeum vulgare) requires Rpg5, a second NBS-LRR gene, and an actin depolymerization factor

The rpg4 gene confers recessive resistance to several races of wheat stem rust (Puccinia graminis f. sp. tritici) and Rpg5 provides dominant resistance against isolates of the rye stem rust (P. graminis f. sp. secalis) in barley. The rpg4 and Rpg5 genes are tightly linked on chromosome 5H, and positional cloning using high-resolution populations clearly separated the genes, unambiguously identifying Rpg5; however, the identity of rpg4 remained unclear. High-resolution genotyping of critical recombinants at the rpg4/Rpg5 locus, designated here as rpg4-mediated resistance locus (RMRL) delimited two distinct yet tightly linked loci required for resistance, designated as RMRL1 and RMRL2. Utilizing virus-induced gene silencing, each gene at RMRL1, i.e., HvRga1 (a nucleotide-binding site leucine-rich repeat [NBS-LRR] domain gene), Rpg5 (an NBS-LRR-protein kinase domain gene), and HvAdf3 (an actin depolymerizing factor-like gene), was individually silenced followed by inoculation with P. graminis f. sp. tritici race QCCJ. Silencing each gene changed the reaction type from incompatible to compatible, indicating that all three genes are required for rpg4-mediated resistance. This stem rust resistance mechanism in barley follows the emerging theme of unrelated pairs of genetically linked NBS-LRR genes required for specific pathogen recognition and resistance. It also appears that actin cytoskeleton dynamics may play an important role in determining resistance against several races of stem rust in barley.

Ethanol flush for the prevention of catheter occlusion

Catheter occlusion by lipid material has been associated with the use of compounded nutrient solutions containing lipid. We have studied the incidence of catheter occlusion when either a saline or an ethanol flush has been used prior to the application of a heparin lock following an overnight infusion of such nutrients. Lipid occlusion occured in 13 of 23 catheters when a saline flush preceeded the application of a heparin lock, whereas the use of a 20% ethanol solution before the application of the heparin lock resulted in only 2 occlusoins in 28 catheters (p < 0.001). In addition there was significantly longer catheter survival in the ethanol group (p < 0.01). It is concluded that an ethanol flush may significantly reduce the incidence of catheter occlusion during the use of lipid mixes.

Distal embolization from medial cystic degeneration of the popliteal artery

This is the first reported case of medial cystic degeneration of the popliteal artery presenting as distal embolization and contains a high-definition photo of the cyst in situ. Duplex ultrasound and magnetic resonance angiography are useful adjuncts to diagnosis. Based on the published literature, resection and interposition grafting appears to be the most efficacious treatment modality.

Adequacy of thyroid hormone replacement in a general population

BACKGROUND

Suboptimal thyroid hormone replacement may carry harmful health consequences.

AIMS

Our objectives were to determine the prevalence and factors associated with inadequate replacement in patients receiving treatment with levothyroxine.

DESIGN

Retrospective general practice audit.

METHODS

We identified levothyroxine users through electronic searches of primary care records in all 11 practices within a county borough. The adequacy of thyroid hormone replacement was determined from the current serum, serum thyrotropin (TSH) as: (i) adequate replacement (normal TSH; 0.4-4.0 mU/l); (ii) over replacement (low TSH; <0.4 mU/l); and (iii) under replacement (high TSH; >4.0 mU/l).

RESULTS

Out of a registered patient population of 58 567, we identified 1037 patients who were first included in the hypothyroidism disease register between January 2004 and December 2009 (mean age 62.4 ± 15.9 years; female 85.9%, male 14.1%). Inadequate replacement was seen in 385 patients (37.2%), comprising 205 patients (19.8%) with over replacement and 180 patients (17.4%) with under replacement. Step-wise logistic regression showed that the factors associated with under replacement were male gender [odds ratio (OR) 2.85, confidence interval (CI) 1.86-4.38; P < 0.001 and younger age (OR 0.88, CI 0.80-0.98; P = 0.02 per 10 year increase in age) while longer duration of treatment was associated with over-treatment (OR 1.06, CI 1.01-1.10). A thyroid function test was performed in the preceding 12 months in 914 patients (88.1%) and appropriate dose adjustments had been made in 81.0% (312/385) of patients with abnormal results.

CONCLUSION

Despite frequent monitoring and dose adjustment activities, inadequate thyroid hormone replacement remained a problem in over a third of levothyroxine users in this population.