Prevention of catheter-related bacteremia with a daily ethanol lock in patients with tunnelled catheters: a randomized, placebo-controlled trial

Comparing ethanol lock therapy versus vancomycin lock in a salvation strategy for totally implantable vascular access device infections due to coagulase-negative staphylococci (the ETHALOCK study): a prospective double-blind randomized clinical trial

OBJECTIVES

Little is known about efficacy and safety of ethanol lock therapy (ELT) to treat totally implantable venous access device (TIVAD) infections. The objective of this trial was to evaluate the effectiveness and safety profile of a local treatment with ELT without removal for TIVAD infection due to coagulase-negative staphylococci.

METHODS

We performed a prospective, multicenter, double-blind, randomized clinical trial comparing the efficacy of 40% ELT versus vancomycin lock therapy (VLT) in TIVAD infections due to coagulase-negative staphylococci, complicated or not by bloodstream infection.

RESULTS

Thirty-one patients were assigned to the ELT group and 30 to the VLT arm. Concomitant bacteremia was present in 41 patients (67.2%). Treatment success was 58.1 % (18 of 31) for the ELT arm and 46.7% (14 of 30) for the VLT arm (p = 0.37). The overall treatment success was 52.5% (32). The risk of treatment failure due to uncontrolled infections, superinfections, and mechanical complications did not differ significantly between participants receiving ELT (13 out of 31 [42%]) and those receiving VLT (16 out of 30 [53%]) with a hazard ratio of 0.70 (p = 0.343; 95% CI [0.34-1.46], Cox model). Catheter malfunctions were significantly more frequent in the ELT arm (11 patients versus 2 in the VLT group, p = 0.01).

CONCLUSIONS

We found an overall high rate of treatment failure that did not differ between the ELT arm and the VLT arm. TIVAD removal must be prioritized to prevent complications (uncontrolled infections, superinfections, and catheter malfunctions) except in exceptional situations.

Reevaluation of lock solutions for Central venous catheters in hemodialysis: a narrative review

BACKGROUND

A significant proportion of incident and prevalent hemodialysis patients have central venous catheters for vascular access. No consensus is available on the prevention of catheter dysfunction or catheter-related bloodstream infections in patients undergoing hemodialysis by means of catheter lock solutions.

METHOD

We reviewed the effects of single and combined anticoagulants with antibacterial catheter lock solutions or other antimicrobials for the prevention of thrombosis or infections in hemodialysis patients. Relative risks with 95% confidence intervals for trials of the same type of catheter locking solution were pooled.

SOURCES OF INFORMATION

We included original research articles in English from PubMed, EMBASE, SpringerLink, Elsevier and Ovid using the search terms 'hemodialysis,' 'central venous catheter,' 'locking solution,' 'UFH,' 'low molecular weight heparin,' 'EDTA,' 'citrate,' 'rt-PA,' 'urokinase,' 'gentamicin,' 'vancomycin', 'taurolidine,' 'sodium bicarbonate,' 'hypertonic saline' and 'ethanol' and 'catheter'.

FINDINGS

Low-dose heparin lock solution (< 5000 U/ml) can efficiently achieve anticoagulation and will not increase the risk of bleeding. Low-concentration citrate (< 5%) combined with rt-PA can effectively prevent catheter infection and dysfunction. Catheter-related infections may be minimized by choosing the appropriate antibiotic and dose.

LIMITATIONS

There is a lack of follow-up validation data for LMWH, EDTA, taurolidine, sodium bicarbonate, ethanol, and other lock solutions.

IMPLICATIONS

Since catheterization is common in hemodialysis units, studies on long-term treatment and preventative strategies for catheter dysfunction and catheter-related infection are warranted.

Salvage of infected tunneled hemodialysis catheters using 70% ethanol lock solution: A brief report

Tunneled hemodialysis catheters are the lifeline to patients on maintenance hemodialysis with failed arteriovenous fistulas. However, thrombosis and infection are the main causes of reduced longevity of these accesses. According to IDSA guidelines, catheter-related infection with Pseudomonas and fungi are absolute indications for catheter removal. Considering the cost and difficulties in catheter replacement, for those in whom all accesses are exhausted, retaining the same catheter may be lifesaving. We would like to present two patients in whom, 70% ethanol instillation was used to eradicate infection with these organisms as confirmed by repeat cultures post procedure. Hemodialysis is being successfully continued through the same catheter.

Single-nucleus RNA sequencing of plant tissues using a nanowell-based system

Single-cell genomics provides unprecedented potential for research on plant development and environmental responses. Here, we introduce a generic procedure for plant nucleus isolation combined with nanowell-based library preparation. Our method enables the transcriptome analysis of thousands of individual plant nuclei. It serves as an alternative to the use of protoplast isolation, which is currently a standard methodology for plant single-cell genomics, although it can be challenging for some plant tissues. We show the applicability of our nucleus isolation method by using different plant materials from different species. The potential of our single-nucleus RNA sequencing method is shown through the characterization of transcriptomes of seedlings and developing flowers from Arabidopsis thaliana. We evaluated the transcriptome dynamics during the early stages of anther development, identified stage-specific activities of transcription factors regulating this process, and predicted potential target genes of these transcription factors. Our nucleus isolation procedure can be applied in different plant species and tissues, thus expanding the toolkit for plant single-cell genomics experiments.

Serological survey of SARS-CoV-2 incidence conducted at a rural West Virginia hospital

The SARS-CoV-2 pandemic has affected all types of global communities. Differences in urban and rural environments have led to varying levels of transmission within these subsets of the population. To fully understand the prevalence and impact of SARS-CoV-2 it is critical to survey both types of community. This study establishes the prevalence of SARS-CoV-2 in a rural community: Montgomery, West Virginia. Approximately 10% of participants exhibited serological or PCR-based results indicating exposure to SARS-CoV-2 within 6 months of the sampling date. Quantitative analysis of IgG levels against SARS-CoV-2 receptor binding domain (RBD) was used to stratify individuals based on antibody response to SARS-CoV-2. A significant negative correlation between date of exposure and degree of anti-SARS-CoV-2 RBD IgG (R ² = 0.9006) was discovered in addition to a correlation between neutralizing anti-SARS-CoV-2 antibodies (R ² = 0.8880) and days post exposure. Participants were confirmed to have normal immunogenic profiles by determining serum reactivity B. pertussis antigens commonly used in standardized vaccines. No significant associations were determined between anti-SARS-CoV-2 RBD IgG and age or biological sex. Reporting of viral-like illness symptoms was similar in SARS-CoV-2 exposed participants greater than 30 years old (100% reporting symptoms 30-60 years old, 75% reporting symptoms >60 years old) in contrast to participants under 30 years old (25% reporting symptoms). Overall, this axnalysis of a rural population provides important information about the SARS-CoV-2 pandemic in small rural communities. The study also underscores the fact that prior infection with SARS-CoV-2 results in antibody responses that wane over time which highlights the need for vaccine mediated protection in the absence of lasting protection.

Effect of manual and digital contact tracing on COVID-19 outbreaks: a study on empirical contact data

Non-pharmaceutical interventions are crucial to mitigate the COVID-19 pandemic and contain re-emergence phenomena. Targeted measures such as case isolation and contact tracing can alleviate the societal cost of lock-downs by containing the spread where and when it occurs. To assess the relative and combined impact of manual contact tracing (MCT) and digital (app-based) contact tracing, we feed a compartmental model for COVID-19 with high-resolution datasets describing contacts between individuals in several contexts. We show that the benefit (epidemic size reduction) is generically linear in the fraction of contacts recalled during MCT and quadratic in the app adoption, with no threshold effect. The cost (number of quarantines) versus benefit curve has a characteristic parabolic shape, independent of the type of tracing, with a potentially high benefit and low cost if app adoption and MCT efficiency are high enough. Benefits are higher and the cost lower if the epidemic reproductive number is lower, showing the importance of combining tracing with additional mitigation measures. The observed phenomenology is qualitatively robust across datasets and parameters. We moreover obtain analytically similar results on simplified models.

Central venous catheter-related infections in hematology and oncology: 2020 updated guidelines on diagnosis, management, and prevention by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Cancer patients frequently require central venous catheters for therapy and parenteral nutrition and are at high risk of central venous catheter-related infections (CRIs). Moreover, CRIs prolong hospitalization, cause an excess in resource utilization and treatment cost, often delay anti-cancer treatment, and are associated with a significant increase in mortality in cancer patients. We therefore summoned a panel of experts by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) and updated our previous guideline on CRIs in cancer patients. After conducting systematic literature searches on PubMed, Medline, and Cochrane databases, video- and meeting-based consensus discussions were held. In the presented guideline, we summarize recommendations on definition, diagnosis, management, and prevention of CRIs in cancer patients including the grading of strength of recommendations and the respective levels of evidence. This guideline supports clinicians and researchers alike in the evidence-based decision-making in the management of CRIs in cancer patients.

Synergistic activity of tetrasodium EDTA, ethanol and chlorhexidine hydrochloride against planktonic and biofilm cells of clinically relevant pathogens

OBJECTIVES

Biofilms associated with implantable medical devices and wounds are clinically relevant, often requiring repeated use of antibiotics without success. A search for non-antibiotic antimicrobial and antibiofilm solutions is warranted, in line with antimicrobial stewardship. Our study aimed to evaluate the broad-spectrum antimicrobial efficacy of tetrasodium EDTA, ethanol and chlorhexidine hydrochloride (HCl) alone and in combination against clinically relevant planktonic and biofilm cells of bacterial and fungal pathogens.

METHODS

MICs and MBCs were determined for tetrasodium EDTA, ethanol and chlorhexidine HCl against planktonic cells of test pathogens. The MBEC Assay® biofilm inoculator device was used to evaluate the biofilm eradication ability of test antimicrobials alone and in combination against clinically relevant pathogens. The checkerboard microbroth dilution assay was performed to analyze the synergism between test antimicrobials.

RESULTS

Against planktonic cells, the combination of tetrasodium EDTA with ethanol or chlorhexidine HCl resulted in synergistic to indifferent activity, with no antagonism observed. Against mature biofilms, all combinations were synergistic. The MBEC of each test antimicrobial was decreased from 4- to -64-fold when used in combination as compared to when agents were used alone. We optimised the concentration of antimicrobials to achieve rapid eradication of pre-formed biofilms. A triple combination of 3% tetrasodium EDTA, 20% ethanol and 2.5 μg/mL chlorhexidine HCl completely eradicated 48-h-old biofilms of all test strains within 2 h.

CONCLUSION

All three antimicrobial agents can be used together for prevention and treatment of biofilms and biofilm-related infections. The observed in vitro efficacy should be tested further through in vivo and clinical studies.

Implications for tetraspanin-enriched microdomain assembly based on structures of CD9 with EWI-F

Crystal and single-particle cryo-EM structures reveal how the tetraspanin CD9 interacts with its prototypical partner EWI-F and provide a new concatenation model for the assembly of tetraspanin-enriched microdomains.

Tetraspanins are eukaryotic membrane proteins that contribute to a variety of signaling processes by organizing partner-receptor molecules in the plasma membrane. How tetraspanins bind and cluster partner receptors into tetraspanin-enriched microdomains is unknown. Here, we present crystal structures of the large extracellular loop of CD9 bound to nanobodies 4C8 and 4E8 and, the cryo-EM structure of 4C8-bound CD9 in complex with its partner EWI-F. CD9–EWI-F displays a tetrameric arrangement with two central EWI-F molecules, dimerized through their ectodomains, and two CD9 molecules, one bound to each EWI-F transmembrane helix through CD9-helices h3 and h4. In the crystal structures, nanobodies 4C8 and 4E8 bind CD9 at loops C and D, which is in agreement with the 4C8 conformation in the CD9–EWI-F complex. The complex varies from nearly twofold symmetric (with the two CD9 copies nearly anti-parallel) to ca. 50° bent arrangements. This flexible arrangement of CD9–EWI-F with potential CD9 homo-dimerization at either end provides a “concatenation model” for forming short linear or circular assemblies, which may explain the occurrence of tetraspanin-enriched microdomains.

Ultrasound Doppler and tenosynovial fluid analysis in tenosynovitis

OBJECTIVE

To assess Doppler ultrasound (US) and tenosynovial fluid (TSF) characteristics in tenosynovitis within common rheumatic conditions, as well as their diagnostic utility.

METHODS

Subjects with tenosynovitis underwent Doppler US and US-guided TSF aspiration for white cell count (WCC) and crystal analysis. Tenosynovial Doppler scores (DS) were semiquantitatively graded. TSF WCC and DS were compared using Kruskal-Wallis tests and logistic regression between non-inflammatory conditions (NIC), inflammatory conditions (IC) and crystal-related conditions (CRC). Receiver operating curves, sensitivity and specificity assessed the ability of WCC and DS to discriminate IC from NIC.

RESULTS

We analysed 100 subjects from 14 sites. The mean age was 62 years, 65% were female, and the mean TSF volume was 1.2 mL. Doppler signal was present in 93.7% of the IC group and was more frequent in IC than in NIC group (OR 6.82, 95% CI 1.41 to 32.97). The TSF median WCC per 10⁹/L was significantly higher in the IC (2.58, p<0.001) and CRC (1.07, p<0.01) groups versus the NIC group (0.38). A TSF cut-off of ≥0.67 WCC per 10⁹/L optimally discriminated IC versus NIC with a sensitivity and specificity each of 81.3%. In the IC group, 20 of 48 (41.7%) subjects had a TSF WCC <2.00 per 10⁹/L.

CONCLUSIONS

A negative DS helps rule out IC in tenosynovitis, but a positive DS is non-specific and merits TSF testing. Unlike synovial fluid, a lower TSF WCC better discriminates IC from NIC. US guidance facilitates aspiration of minute TSF volume, which is critical for diagnosing tenosynovial CRC.

A Randomized, Double-Blind, Placebo-Controlled Trial (TAURCAT Study) of Citrate Lock Solution for Prevention of Endoluminal Central Venous Catheter Infection in Neutropenic Hematological Patients

Infection of long-term central venous catheters (CVCs) remains a challenge in the clinical management of cancer patients. We aimed to determine whether a lock solution with taurolidine-citrate-heparin would be more effective than placebo for preventing nontunneled CVC infection in high-risk neutropenic hematologic patients. We performed a prospective, multicenter, randomized (1:1), double-blind, parallel, superiority, placebo-controlled trial involving 150 hematological patients with neutropenia carrying nontunneled CVCs who were assigned to receive CVC lock solution with taurolidine-citrate-heparin or heparin alone. The primary endpoint was bacterial colonization of the CVC hubs. Secondary endpoints were the incidence of catheter-related bloodstream infection (CRBSI), CVC removal, adverse events related to the lock solution, and the 30-day case fatality rate. CVC lock solution with taurolidine-citrate-heparin was associated with less colonization of the CVC hubs than that with placebo, with no statistically significant differences: 4.1%, versus 10.1% (relative risk [RR] = 0.41, 95% confidence interval [CI] = 0.11 to 1.52), with a cumulative incidence of 4.17 (95% CI = 0.87 to 11.70) and 10.14 (95% CI = 4.18 to 19.79), respectively. There were no significant differences regarding the secondary endpoints. Only three episodes of CRBSI occurred during the study period. No adverse events related to the administration of the lock solution occurred. In this trial involving high-risk patients carrying nontunneled CVCs, the use of taurolidine-citrate-heparin did not show a benefit over the use of placebo. Nevertheless, the safety of this prevention strategy and the trend toward less hub colonization in the taurolidine-citrate-heparin group raise the interest in assessing its efficacy in centers with higher rates of CRBSI. (This study has been registered in ISRCTN under identifier ISRCTN47102251.).

Diagnosis and management of catheter-related bloodstream infections in patients on home parenteral nutrition

Catheter-related bloodstream infections (CRBSIs) commonly arise from a parenteral nutrition catheter hub. A target for a Nutrition Support Team is to have a CRBSI rate of less than 1 per 1000. The diagnosis of CRBSI is suspected clinically by a temperature shortly after setting up a feed, general malaise or raised blood inflammatory markers. It is confirmed by qualitative and quantitative blood cultures from the catheter and peripherally. Treatment of inpatients may involve central venous catheter removal and antibiotics for patients needing short-term parenteral nutrition, but catheter salvage is generally recommended for patients needing long-term parenteral nutrition, where appropriate.

Validity of surrogate endpoints assessing central venous catheter-related infection: evidence from individual- and study-level analyses

OBJECTIVES

The prevention of catheter-related bloodstream infection (CRBSI) has been an area of intense research, but the heterogeneity of endpoints used to define catheter infection makes the interpretation of randomized controlled trials (RCTs) problematic. The aim of this study was to determine the validity of different endpoints for central venous catheter infections.

DATA SOURCES

(a) Individual-catheter data were collected from 9428 catheters from four large RCTs; (b) study-level data from 70 RCTs were identified with a systematic search. Eligible studies were RCTs published between January 1987 and October 2018 investigating various interventions to reduce infections from short-term central venous catheters or short-term dialysis catheters. For each RCT the prevalence rates of CRBSI, quantitative catheter tip colonization, catheter-associated infection (CAI) and central line-associated bloodstream infection (CLABSI) were extracted for each randomized study arm.

METHODS

CRBSI was used as the gold-standard endpoint, for which colonization, CAI and CLABSI were evaluated as surrogate endpoints. Surrogate validity was assessed as (1) the individual partial coefficient of determination (individual-pR²) using individual catheter data; (2) the coefficient of determination (study-R²) from mixed-effect models regressing the therapeutic effect size of the surrogates on the effect size of CRBSI, using study-level data.

RESULTS

Colonization showed poor agreement with CRBSI at the individual-patient level (pR² = 0.33 95% CI 0.28-0.38) and poor capture at the study level (R² = 0.42, 95% CI 0.21-0.58). CAI showed good agreement with CRBSI at the individual-patient level (pR² = 0.80, 95% CI 0.76-0.83) and moderate capture at the study level (R² = 0.71, 95% CI 0.51-0.85). CLABSI showed poor agreement with CRBSI at the individual patient level (pR² = 0.34, 95% CI 0.23-0.46) and poor capture at the study level (R² = 0.28, 95% CI 0.07-0.76).

CONCLUSIONS

CAI is a moderate to good surrogate endpoint for CRBSI. Colonization and CLABSI do not reliably reflect treatment effects on CRBSI and are consequently more suitable for surveillance than for clinical effectiveness research.

Ethanol locks for the prevention of catheter-related infection in patients with central venous catheter: A systematic review and meta-analysis of randomized controlled trials

Background

The widespread use of central venous catheters (CVCs) has exposed patients to a high risk of catheter-related infection (CRI), which is linked to substantial morbidity and mortality. Several strategies for preventing CRI, including ethanol lock prophylaxis, have been explored. This study aimed to provide a comprehensive summary of randomized controlled trials (RCTs) assessing the efficacy and safety of ethanol locks for preventing CRI in patients with CVC.

Methods

We searched six electronic databases, earlier relevant meta-analyses and the reference lists of the included studies for RCTs that assessed the effects of ethanol locks on CRI in patients with CVC versus a control group. Two authors independently assessed the methodological quality of the included studies using the Cochrane Risk of Bias tool and extracted relevant information according to a predesigned extraction form. Data were analyzed using the Cochrane Collaboration’s RevMan 5.3.

Results

Nine studies involving 2451 patients were included. Although limited in power, the results of the meta-analysis indicated a positive effect of ethanol lock prophylaxis on reducing catheter-related bloodstream infection (CRBSI) compared to heparin alone [OR = 0.53, 95% CI 0.34, 0.82, P = 0.004]. The effects on other outcomes, such as exit site infection, catheter dysfunction, catheter removal, thrombosis and mortality, were not statistically significant (P > 0.05). Moreover, although the effect of ethanol on CRBSI was in the expected direction compared to 0.9% NaCl locks, this effect was not statistically significant (P > 0.05).

Conclusions

The present data indicate that ethanol lock prophylaxis is a potential candidate for the prevention of CRBSI in patients with CVC. However, more attention should be paid to the uniform ethanol lock procedure and toxic effects after long-term ethanol lock exposure.

Diagnosis and treatment of catheter-related bloodstream infection: Clinical guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and (SEIMC) and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC)

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications.

International experience with minocycline, EDTA and ethanol lock for salvaging of central line associated bloodstream infections

BACKGROUND

The use of long-term central venous catheters (CVCs) could lead to serious bloodstream infections. Removal of the infected CVC and reinsertion of a new CVC are not always feasible and alternative lock therapy may be considered. We conducted a multicenter trial to assess the efficacy and safety of the lock therapy.

METHODS

Between October 2013 and August 2014, we prospectively enrolled 20 patients with catheter-related bloodstream infections (CRBSIs) or central line-associated bloodstream infections (CLABSIs) in our sister institutions in three countries including Brazil, Lebanon, and Japan. The 20 patients who received M-EDTA-EtOH lock therapy were compared to 24 control patients who had their CVCs removed and a new CVC inserted.

RESULTS

Both groups had comparable clinical characteristics. In the lock therapy group, 95% of the patients had microbiological eradication within 96 h after starting lock therapy versus 83% of the patients in the control group (p = .36). In the lock group, the CVC was salvaged and retained for a median of 21 days (range 7-51) from the onset of bacteremia.

CONCLUSION

Our study suggests that M-EDTA-EtOH lock therapy may be an effective intervention to salvage long-term CVCs in the setting of CLABSI/CRBSI and hemodialysis cancer patients with limited vascular access.

Ethanol lock is effective on reducing the incidence of tunneled catheter-related bloodstream infections in hemodialysis patients: a systematic review and meta-analysis

PURPOSE

The purpose of this meta-analysis is to evaluate the effect of ethanol lock on the incidence of catheter-related bloodstream infection (CRBSI) in patients with central venous catheters.

METHODS

RCTs comparing ethanol lock with another solution lock for prevention of CRBSI were obtained by searching databases of PubMed, Embase, Web of Science and Cochrane Central Register of clinical trials for eligible randomized controlled trials (inception to December 2017). Two researchers separately selected the RCTs and assessed their quality. Data on patient characteristics and ethanol protocols were collected. The primary outcome was the incidence of CRBSI, and the secondary outcomes were catheter colonization, exit infection and thrombosis.

RESULTS

A total of 2575 patients with 3375 catheters from 7 eligible RCTs were included. Overall, ethanol lock significantly decreased the risk of CRBSI, with RR 0.54 (95% CI 0.38-0.78; I2 = 0%; p = 0.001); no obvious heterogeneity was observed in the fixed-effects model (I2 = 0%). Of note, subgroup analysis demonstrated that ethanol lock conferred significant benefit in studies with tunneled catheters (RR 0.46; 95% CI 0.30-0.72) but not in studies with untunneled catheters. Only two studies provided data regarding catheter colonization, and no significant difference was found (RR, 1.09; 95% CI, 0.87-1.38; I2 = 41%; p = 0.45). Moreover, pooled data did not show significant differences between ethanol and control groups with regard to the incidence of thrombosis (RR 1.05; 95% CI 0.91-1.22; I2 = 0%; p = 0.48).

CONCLUSIONS

Our meta-analysis suggests that ethanol lock is effective on reducing the incidence of CRBSI in hemodialysis patients with tunneled central venous catheters.

Comparison of Copper(II)-Ligand Complexes as Mediators for Preparing Electrochemically Modulated Nitric Oxide-Releasing Catheters

Further studies aimed at examining the activity of different Cu(II)-ligand complexes to serve as electron-transfer mediators to prepare novel antimicrobial/thromboresistant nitric oxide (NO)-releasing intravenous catheters are reported. In these devices, the NO release can be modulated by applying different potentials or currents to reduce the Cu(II)-complexes to Cu(I) species which then reduce nitrite ions into NO_(g) within a lumen of the catheter. Four different ligands are compared with respect to NO generation efficiency and stability over time using both single- and dual-lumen silicone rubber catheters: N-propanoate- N, N-bis(2-pyridylethyl)amine (BEPA-Pr), N-propanoate- N, N-bis(2-pyridylmethyl)amine (BMPA-Pr), 1,4,7-trimethyl-1,4,7-triazacyclononane (Me₃TACN), and tris(2-pyridylmethyl)amine (TPMA). Of these, the Cu(II)BEPA-Pr and Cu(II)Me₃TACN complexes provide biomedically useful NO fluxes from the surface of the catheters, >2 × 10^-10 mol·min^-1·cm^-2, under conditions mimicking the bloodstream environment. Cu(II)Me₃TACN exhibits the best stability over time with a steady and continuous NO release observed for 8 d under a nitrogen atmosphere. Antimicrobial experiments conducted over 5 d with NO-releasing catheters turned "on" electrochemically for only 3 or 6 h each day revealed >2 logarithmic units in reduction of bacterial biofilm attached to the catheter surfaces. The use of optimal Cu(II)-ligand complexes within a lumen reservoir along with high levels of nitrite ions can potentially provide an effective method of preventing/decreasing the rate of infections caused by intravascular catheters.

Ethanol locks for the prevention of catheter-related bloodstream infection: a meta-analysis of randomized control trials

Background

Current evidence regarding the efficacy of ethanol locks in preventing catheter-related bloodstream infection (CRBI) is inconclusive.

Methods

Electronic databases, including PubMed, Web of Science, Embase, and the Cochrane Library (until April 2018),were systematically searched for relevant studies. Two reviewers independently screened the retrieved records and identified RCTs that met the inclusion criteria. Relevant data were extracted for pooled analyses using Review Manager 5.3 software. Subgroup analysis was performed according to the study quality, duration of the ethanol lock, disease type and CRBI definition. Eggs’ method was applied to detect publication bias. Sensitivity analysis was conducted to check the stability of the meta-analysis results.

Results

Ten RCTs involving 2760 patients were included in the analysis. The overall pooled result indicated that ethanol locks significantly reduced the incidence of CRBI (RR 0.66, 95% CI 0.51–0.86). Subgroup analysis suggested that an ethanol lock significantly decreased the incidence of CRBI in patients with hematological diseases (RR 0.50, 95% CI 0.31–0.80). An ethanol lock significantly reduced the incidence of CRBI in a2-hour ethanol lock group (RR 0.49, 95% CI 0.33–0.73). The meta-analysis showed that an ethanol lock significantly reduced the incidence of CRBI according to analysis of high-(RR 0.66, 95% CI 0.47–0.94) or low-(RR 0.66, 95% CI 0.46–0.95) quality studies. Meta-analysis of studies with a strict CRBI definition showed that an ethanol lock can significantly prevent CRBI (RR 0.61, 95% CI 0.42–0.89). The results of sensitivity analysis suggested that the pooled result was stable. Meta-analysis of adverse events showed that an ethanol lock did not increase the incidence of thrombosis (RR 1.05, 95% CI 0.51–2.18) or mortality (RR 0.99, 95% CI 0.90–1.08) but did result in increased nausea (RR 1.54, 95% CI 1.01–2.35), dizziness (RR 4.21, 95% CI 2.40–7.39),elevated blushing rates (RR 3.27, 95% CI 2.05–5.22) and altered taste rates (RR 2.61, 95% CI 1.93–3.54).

Conclusions

An ethanol lock may play a role in the prevention of CRBI, especially in immunocompromised patients with hematological diseases.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0548-y) contains supplementary material, which is available to authorized users.

Treatment and secondary prophylaxis with ethanol lock therapy for central line-associated bloodstream infection in paediatric cancer: a randomised, double-blind, controlled trial

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) affect about 25% of children with cancer, and treatment failure is common. Adjunctive ethanol lock therapy might prevent treatment failure but high-quality evidence is scarce. We evaluated ethanol lock therapy as treatment and secondary prophylaxis for CLABSI in children with cancer or haematological disorders.

METHODS

This randomised, double-blind, placebo-controlled superiority trial, with two interim futility and efficacy analyses (done when the first 46 and 92 evaluable participants completed study requirements), was done at two paediatric hospitals in the USA and Australia. Patients aged 6 months to 24 years, inclusive, with cancer or a haematological disorder and new CLABSI were eligible. Participants were randomly assigned (1:1) to receive either ethanol lock therapy (70% ethanol) or placebo (heparinised saline) for 2-4 h per lumen daily for 5 days (treatment phase), then for up to 3 non-consecutive days per week for 24 weeks (prophylaxis phase). The primary composite outcome was treatment failure, consisting of attributable catheter removal or death, new or persistent (>72 h) infection, or additional lock therapy during the treatment phase, and recurrent CLABSI during the prophylaxis phase. This trial is registered with ClinicalTrials.gov, number NCT01472965.

FINDINGS

94 evaluable participants were enrolled between Dec 14, 2011, and Sept 12, 2016, of whom 48 received ethanol lock therapy and 46 received placebo. The study met futility criteria at the second interim analysis. Treatment failure was similar with ethanol lock therapy (21 [44%] of 48) and placebo (20 [43%] of 46; relative risk [RR] 1·0, 95% CI 0·6-1·6; p=0·98). Some adverse events, including infusion reactions and catheter occlusion, were more frequent in the ethanol lock therapy group than in the placebo group. Catheter occlusion requiring thrombolytic therapy was more common with ethanol lock therapy (28 [58%] of 48) than with placebo (15 [33%] of 46; RR 1·8, 95% CI 1·1-2·9; p=0·012). Discontinuation of lock therapy because of adverse effects or patient request occurred in a similar proportion of participants in the ethanol lock therapy (nine [19%] of 48) and placebo groups (ten [22%] of 46; p=0·72).

INTERPRETATION

Ethanol lock therapy did not prevent CLABSI treatment failure and it increased catheter occlusion. Routine ethanol lock therapy for treatment or secondary prophylaxis is not recommended in this population.

FUNDING

American Lebanese Syrian Associated Charities to St Jude Children's Research Hospital and an Australian Government Research Training Scholarship.

Administration of taurolidine-citrate lock solution for prevention of central venous catheter infection in adult neutropenic haematological patients: a randomised, double-blinded, placebo-controlled trial (TAURCAT)

Background

Catheter-related bloodstream infection (CRBSI) is one of the most frequent complications in patients with cancer who have central venous catheters (CVCs) implanted and is associated with substantial morbidity and mortality. Taurolidine is a non-antibiotic agent with broad-spectrum antimicrobial activity, which has been used as a lock solution to prevent CRBSI in some settings. However, little is known about its usefulness in high-risk adult neutropenic patients with cancer. This prospective randomised clinical trial aims to test the hypothesis that taurolidine-citrate lock solution is more effective than placebo for preventing catheter infection in neutropenic haematological patients.

Methods

This study is a prospective, multicentre, randomised, double-blinded, parallel, superiority, placebo-controlled trial. Patients with haematological cancer who are expected to develop prolonged neutropenia (> 7 days) and who have a non-tunnelled CVC implanted will be randomised to receive prophylactic taurolidine-citrate-heparin solution using a lock technique (study group) or heparin alone (placebo group). The primary endpoint will be bacterial colonisation of the CVC hubs. The secondary endpoints will be the incidence of CRBSI, CVC removal, adverse events, and 30-day case-fatality rate.

Discussion

The lock technique is a preventive strategy that inhibits bacterial colonisation in the catheter hubs, which is the initial step of endoluminal catheter colonisation and the development of infection. Taurolidine is a nontoxic agent that does not develop antibiotic resistance because it acts as an antiseptic rather than an antibiotic. Taurolidine has shown controversial results in the few trials conducted in cancer patients. These studies have important limitations due to the lack of data on adult and/or high-risk neutropenic patients, the type of catheters studied (tunnelled or ports), and the lack of information regarding the intervention (e.g. dwelling of the solution, time, and periodicity of the lock technique). If our hypothesis is proven, the study could provide important solid evidence on the potential usefulness of this preventive procedure in a population at high risk of CRBSI, in whom this complication may significantly impair patient outcome.

Trial registration

ISRCTN, ISRCTN47102251. Registered on 9 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2647-y) contains supplementary material, which is available to authorized users.

Infection of totally implantable venous access devices: A review of the literature

Totally implantable venous access devices, or ports, are essential in the therapeutic management of patients who require long-term intermittent intravenous therapy. Totally implantable venous access devices guarantee safe infusion of chemotherapy, blood transfusion, parenteral nutrition, as well as repeated blood samples. Minimizing the need for frequent vascular access, totally implantable venous access devices also improve the patient's quality of life. Nonetheless, totally implantable venous access devices are not free from complications. Among those, infection is the most relevant, affecting patients' morbidity and mortality-both in the hospital or outpatient setting-and increasing healthcare costs. Knowledge of pathogenesis and risk factors of totally implantable venous access device-related infections is crucial to prevent this condition by adopting proper insertion bundles and maintenance bundles based on the best available evidence. Early diagnosis and prompt treatment of infection are of paramount importance. As a totally implantable venous access device-related infection occurs, device removal or a conservative approach should be chosen in treating this complication. For both prevention and therapy, antimicrobial lock is a major matter of controversy and a promising field for future clinical studies. This article reviews current evidences in terms of epidemiology, pathogenesis and risk factors, diagnosis, prevention, and treatment of totally implantable venous access device-related infections.

Screening for elevated albuminuria and subsequently hypertension identifies subjects in which treatment may be warranted to prevent renal function decline

Background

We investigated whether initial population screening for elevated albuminuria with subsequent screening for hypertension in case albuminuria is elevated may be of help to identify subjects at risk for accelerated decline in kidney function.

Methods

We included subjects who participate in the PREVEND observational, general population-based cohort study and had two or more glomerular filtration rate (eGFR) measurements available during follow-up. Elevated albuminuria was defined as an albumin concentration ≥20 mg/L in a first morning urine sample confirmed by an albumin excretion ≥30 mg/day in two 24-h urines. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg or use of blood pressure-lowering drugs. eGFR was estimated with the CKD-EPI creatinine-cystatin C equation.

Results

Overall, 6471 subjects were included with a median of 4 [95% confidence interval (CI) 2-5] eGFR measurements during a follow-up of 11.3 (95% CI 4.0-13.7) years. Decline in eGFR was greater in the subgroups with elevated albuminuria. This held true, not only in subjects with known hypertension (-1.84 ± 2.27 versus -1.16 ± 1.45 mL/min/1.73 m 2 per year, P < 0.05), but also in subjects with newly diagnosed hypertension (-1.59 ± 1.55 versus -1.14 ± 1.38 mL/min/1.73 m 2 per year, P < 0.05) and in subjects with normal blood pressure (-1.18 ± 1.85 versus -0.81 ± 1.02 mL/min/1.73 m 2 per year in subjects, P < 0.05). This effect was most pronounced in the population ≥55 years of age and male subjects. In addition, subjects with elevated albuminuria had higher blood pressure than subjects with normoalbuminuria, and in subjects with elevated albuminuria as yet undiagnosed hypertension was twice as prevalent as diagnosed hypertension.

Conclusions

Initial screening for elevated albuminuria followed by screening for hypertension may help to detect subjects with increased risk for a steeper decline in kidney function.

Does Pain Predict Frailty in Older Men and Women? Findings From the English Longitudinal Study of Ageing (ELSA)

Background:

Pain has been suggested to act as a stressor during aging, potentially accelerating declines in health and functioning. Our objective was to examine the longitudinal association between self-reported pain and the development, or worsening, of frailty among older men and women.

Methods:

The study population consisted of 5,316 men and women living in private households in England, mean age 64.5 years, participating in the English Longitudinal Study of Ageing (ELSA). Data from Waves 2 and 6 of ELSA were used in this study with 8 years of follow-up. At Wave 2, participants were asked whether they were “often troubled with pain” and for those who reported yes, further information regarding the intensity of their pain (mild, moderate, or severe) was collected. Socioeconomic status (SES) was assessed using information about the current/most recent occupation and also net wealth. A frailty index (FI) was generated, with the presence of frailty defined as an FI >0.35. Among those without frailty at Wave 2, the association between pain at Wave 2 and frailty at Wave 6 was examined using logistic regression. We investigated whether pain predicted change in FI between Waves 2 and 6 using a negative binomial regression model. For both models adjustments were made for age, gender, lifestyle factors, depressive symptoms, and socioeconomic factors.

Results:

At Wave 2, 455 (19.7%) men and 856 (28.7%) women reported they often experienced moderate or severe pain. Of the 5,159 participants who were nonfrail at Wave 2, 328 (6.4%) were frail by Wave 6. The mean FI was 0.11 (standard deviation [SD] = 0.1) at Wave 2 and 0.15 (SD = 0.1) at Wave 6. After adjustment for age, gender, body mass index, lifestyle factors, and depressive symptoms, compared to participants reporting no pain at Wave 2 those reporting moderate (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 2.28, 4.16) or severe pain (OR = 3.78, 95% CI = 2.51, 5.71) were significantly more likely to be frail at Wave 6. This association persisted after further adjustment for either occupational class and/or net wealth level. Compared to those without pain, those with mild, moderate, or severe pain were also more likely to develop worsening frailty, as assessed using the FI, and this association persisted after adjustment for SES. There was no evidence that the association between pain and frailty was influenced by gender.

Conclusion:

Pain is associated with an increased risk and intensity of frailty in older men and women. Socioeconomic factors contribute to the occurrence of frailty; though in our study do not explain the relationship between pain and frailty.

Comorbidities, mortality and causes of death among patients with tuberculosis in Denmark 1998-2010: a nationwide, register-based case-control study

OBJECTIVE

To evaluate the impact of comorbidities, age and clinical presentation of TB on mortality among Danish patients with TB.

METHODS

Danish patients with an ICD-10 (International Statistical Classification of Diseases and Related Health Problems 10th Revision) diagnosis of TB in 1998-2010 were identified in the National Patient Registry and matched with controls (1:4) on age, gender, civil status and geography. Comorbid diagnoses up to 3 years before and after TB diagnosis or enrolment as control as well as survival data were obtained from national databases RESULTS: We included 8433 cases and 33 707 controls. Respiratory diseases were the most common comorbidities among cases (12.4% of cases, 3.8% of controls (p<0.001)). Overall HR of death was 2.45 (2.31; 2.59). Relative mortality was especially increased among younger adults (HR 8.70 (95% CI 5.53 to 13.69) among the 30 to 39-year-olds). While overall mortality increased with Deyo-Charlson comorbidity (DCC) score, relative mortality among cases was highest in the low-DCC group. Additionally, male gender, low income and central nervous system TB were risk factors for death among TB cases. The most common cause of death in both groups was non-lung cancers, among TB cases followed by COPD, TB and lung cancer, all being significantly more common among TB cases.

CONCLUSION

In Denmark, TB carries substantial mortality. Among those who die, 12% are reported to die from TB. A high relative mortality among younger adults underscores the importance of continually targeting high-risk TB groups in low-incidence countries.

A Novel Nonantibiotic Nitroglycerin-Based Catheter Lock Solution for Prevention of Intraluminal Central Venous Catheter Infections in Cancer Patients

For long-term central lines (CL), the lumen is the major source of central line-associated bloodstream infections (CLABSI). The current standard of care for maintaining catheter patency includes flushing the CL with saline or heparin. Neither agent has any antimicrobial activity. Furthermore, heparin may enhance staphylococcal biofilm formation. We evaluated the safety and efficacy of a novel nonantibiotic catheter lock solution for the prevention of CLABSI. Between November 2015 and February 2016, we enrolled 60 patients with hematologic malignancies who had peripherally inserted central catheters (PICC) to receive the study lock solution. The study lock consisted of 15 or 30 μg/ml of nitroglycerin in combination with 4% sodium citrate and 22% ethanol. Each lumen was locked for at least 2 h once daily prior to being flushed. After enrollment of 10 patients at the lower nitroglycerin dose without evidence of toxicity, the dose was escalated to the higher dose (30 μg/ml). There were no serious related adverse events or episodes of hypotension with lock administration. Two patients experienced mild transient adverse events (one headache and one rash) possibly related to the lock and that resolved without residual effect. The CLABSI rate was 0 on lock days versus 1.6/1,000 catheter days (CD) off lock prophylaxis, compared with a rate of 1.9/1,000 CD at the institution in the same patient population. In conclusion, the nitroglycerin-based lock prophylaxis is safe and well tolerated. It may prevent CLABSI when given daily to cancer patients. Large, prospective, randomized clinical trials are needed to validate these findings. (This study has been registered at ClinicalTrials.gov under identifier NCT02577718.).

Catheter-related infections in patients with haematological malignancies: novel preventive and therapeutic strategies

Central venous catheters are essential for the treatment of patients with haematological malignancies and the recipients of stem-cell transplant. This patient population is, however, at high risk for catheter-related bloodstream infections that can result in substantial morbidity, mortality, and health-care-associated costs. Efficient prevention, early diagnosis, and effective treatment are essential to providing the best care to these patients. Although confirming the catheter as a source of infection remains challenging, the Infectious Diseases Society of America definition of catheter-related bloodstream infection remains the most precise definition to use in these patients. Gram-positive bacteria, particularly coagulase-negative Staphylococcus spp, remain the leading cause of catheter-related bloodstream infection, although an increase in Gram-negative bacteria as the causative agent has been noted. Although removal of the line and appropriate intravenous antibiotics remain the mainstay of treatment in most cases, novel technologies, including exchange with antibiotic-coated catheters and treatment with lock solutions, are particularly relevant in this patient population. In this Review we present the types of central venous catheters used in this patient population and analyse the different definitions of catheter-related infections, with an overview of their prevention and management.

Randomized controlled trials in central vascular access devices: A scoping review

BACKGROUND

Randomized controlled trials evaluate the effectiveness of interventions for central venous access devices, however, high complication rates remain. Scoping reviews map the available evidence and demonstrate evidence deficiencies to focus ongoing research priorities.

METHOD

A scoping review (January 2006-December 2015) of randomized controlled trials evaluating the effectiveness of interventions to improve central venous access device outcomes; including peripherally inserted central catheters, non-tunneled, tunneled and totally implanted venous access catheters. MeSH terms were used to undertake a systematic search with data extracted by two independent researchers, using a standardized data extraction form.

RESULTS

In total, 178 trials were included (78 non-tunneled [44%]; 40 peripherally inserted central catheters [22%]; 20 totally implanted [11%]; 12 tunneled [6%]; 6 non-specified [3%]; and 22 combined device trials [12%]). There were 119 trials (68%) involving adult participants only, with 18 (9%) pediatric and 20 (11%) neonatal trials. Insertion-related themes existed in 38% of trials (67 RCTs), 35 RCTs (20%) related to post-insertion patency, with fewer trials on infection prevention (15 RCTs, 8%), education (14RCTs, 8%), and dressing and securement (12 RCTs, 7%). There were 46 different study outcomes reported, with the most common being infection outcomes (161 outcomes; 37%), with divergent definitions used for catheter-related bloodstream and other infections.

CONCLUSION

More high quality randomized trials across central venous access device management are necessary, especially in dressing and securement and patency. These can be encouraged by having more studies with multidisciplinary team involvement and consumer engagement. Additionally, there were extensive gaps within population sub-groups, particularly in tunneled devices, and in pediatrics and neonates. Finally, outcome definitions need to be unified for results to be meaningful and comparable across studies.

The Health Burden of Invasive Meningococcal Disease: A Systematic Review

OF KEY POINTS

Although relatively rare, invasive meningococcal disease continues to be a health concern, especially in young children. This systematic review clearly delineates both the near- and long-term morbidities that can occur after, and persist beyond, the period of acute illness.

BACKGROUND

Although rare, invasive meningococcal disease (IMD) continues to be a health concern in high-income countries because of its severe morbidity and relatively high case fatality rate, especially in young children. However, studies measuring sequelae of IMD across the spectrum of invasive syndromes have not been systematically reviewed. We conducted a systematic review of sequelae attributable to IMD and quality of life (QoL) in IMD survivors in high-income countries.

METHODS

We searched Medline, Embase, and HealthSTAR for primary studies that assessed sequelae or QoL in individuals of any age with and without IMD. Two independent reviewers screened articles, abstracted data, and performed quality appraisal. The findings were summarized qualitatively.

RESULTS

Of 1884 citations screened, 17 studies were included. The most commonly assessed sequelae were hearing impairment, cognitive impairment, and psychological problems. In general, children with IMD had a greater incidence of hearing loss and psychological disorders, including attention-deficit/hyperactivity disorder. However, its effects on intelligence in children remain unclear. No statistical differences in overall cognitive function in adults were reported. The odds of death were significantly increased with IMD at hospital discharge and up to 30 years after disease. Lower overall QoL was observed in those who had IMD versus controls.

CONCLUSIONS

The results of this systematic review delineate both the short- and long-term morbidities that can occur after, and persist beyond, the period of acute illness. A better understanding of the full spectrum of IMD sequelae is critical for assessing the burden of IMD and supporting healthcare planning and decision making in light of new vaccines.

Loss of AKAP150 promotes pathological remodelling and heart failure propensity by disrupting calcium cycling and contractile reserve

AIMS

Impaired Ca^2 +cycling and myocyte contractility are a hallmark of heart failure triggered by pathological stress such as hemodynamic overload. The A-Kinase anchoring protein AKAP150 has been shown to coordinate key aspects of adrenergic regulation of Ca²⁺cycling and excitation-contraction in cardiomyocytes. However, the role of the AKAP150 signalling complexes in the pathogenesis of heart failure has not been investigated.

METHODS AND RESULTS

Here we examined how AKAP150 signalling complexes impact Ca²⁺cycling, myocyte contractility, and heart failure susceptibility following pathological stress. We detected a significant reduction of AKAP150 expression in the failing mouse heart induced by pressure overload. Importantly, cardiac-specific AKAP150 knockout mice were predisposed to develop dilated cardiomyopathy with severe cardiac dysfunction and fibrosis after pressure overload. Loss of AKAP150 also promoted pathological remodelling and heart failure progression following myocardial infarction. However, ablation of AKAP150 did not affect calcineurin-nuclear factor of activated T cells signalling in cardiomyocytes or pressure overload- or agonist-induced cardiac hypertrophy. Immunoprecipitation studies showed that AKAP150 was associated with SERCA2, phospholamban, and ryanodine receptor-2, providing a targeted control of sarcoplasmic reticulum Ca²⁺regulatory proteins. Mechanistically, loss of AKAP150 led to impaired Ca²⁺cycling and reduced myocyte contractility reserve following adrenergic stimulation or pressure overload.

CONCLUSIONS

These findings define a critical role for AKAP150 in regulating Ca²⁺cycling and myocardial ionotropy following pathological stress, suggesting the AKAP150 signalling pathway may serve as a novel therapeutic target for heart failure.

An Evaluation of the Honey Bee (Hymenoptera: Apidae) Safety Profile of a New Systemic Insecticide, Flupyradifurone, Under Field Conditions in Florida

Flupyradifurone (Sivanto) is a novel systemic insecticide from the butenolide class developed by Bayer. Based on available data (USEPA 2014), this insecticide appears to have a favorable safety profile for honey bee colonies. As a result, the label permits the product to be applied during prebloom and bloom in various crops, including citrus, except when mixed with azole fungicides during the blooming period. We placed 24 honey bee (Apis mellifera L.) colonies adjacent to eight flowering buckwheat (Fagopyrum esculentum Moench) fields that either had been sprayed with the maximum label rate of flupyradifurone or with water only (control fields), with three colonies placed adjacent to each field. We conducted colony strength assessments during which the number of adult bees, eggs, uncapped brood cells, capped brood cells, food storage cells, and weights of honey supers and brood chambers were determined prior to, during, and after the flowering period. We also analyzed bee-collected pollen and nectar for flupyradifurone residues. Overall, there were no differences in any colony strength parameter for colonies placed at control and flupyradifurone-treated buckwheat fields. Residue analyses showed that pollen (x =  565.8 ppb) and nectar (x  =  259.4 ppb) gathered by bees on fields treated with flupyradifurone contained significantly higher flupyradifurone residues than did bee bread and unprocessed nectar collected by bees from control fields (75% of samples <LOD). Within the conditions set forth by our experimental design, our collective data suggest no adverse effects of flupyradifurone on honey bee colonies when following label directions.

Does Arterial Flow Rate Affect the Assessment of Flow-Diverter Stent Performance?

BACKGROUND AND PURPOSE

Our aim was to assess the performance of flow-diverter stents. The pre- and end-of-treatment angiographies are commonly compared. However, the arterial flow rate may change between acquisitions; therefore, a better understanding of its influence on the local intra-aneurysmal hemodynamics before and after flow-diverter stent use is required.

MATERIALS AND METHODS

Twenty-five image-based aneurysm models extracted from 3D rotational angiograms were conditioned for computational fluid dynamics simulations. Pulsatile simulations were performed at different arterial flow rates, covering a wide possible range of physiologic flows among 1-5 mL/s. The effect of flow-diverter stents on intra-aneurysmal hemodynamics was numerically simulated with a porous medium model. Spatiotemporal-averaged intra-aneurysmal flow velocity and flow rate were calculated for each case to quantify the hemodynamics after treatment. The short-term flow-diverter stent performance was characterized by the relative velocity reduction inside the aneurysm.

RESULTS

Spatiotemporal-averaged intra-aneurysmal flow velocity before and after flow-diverter stent use is linearly proportional to the mean arterial flow rate (minimum R² > 0.983 of the linear regression models for untreated and stented models). Relative velocity reduction asymptotically decreases with increasing mean arterial flow rate. When the most probable range of arterial flow rate was considered (3-5 mL/s), instead of the wide possible flow range, the mean SD of relative velocity reduction was reduced from 3.6% to 0.48%.

CONCLUSIONS

Both intra-aneurysmal aneurysm velocity and flow-diverter stent performance depend on the arterial flow rate. The performance could be considered independent of the arterial flow rates within the most probable range of physiologic flows.

Efficacy of ethanol locks to reduce the incidence of catheter-related bloodstream infections for home parenteral nutrition pediatric patients: comparison of therapeutic treatment with prophylactic treatment

PURPOSE

Children with intestinal failure (IF) requiring central venous catheters (CVCs) often experience frequent catheter-related bloodstream infections (CRBSIs), which is a serious and life-threatening complication. To reduce the incidence of CRBSI, prophylactic ethanol lock therapy (ELT) was initiated.

METHODS

Patients with IF received home parenteral nutrition via a silicone tunneled CVC. All of them had received therapeutic ELT from January 2009 (first period) and prophylactic ELT from December 2012 (second period). Prophylactic ELT refers to ethanol lock for 2 h during the monthly hospital visit. We compared the CRBSI rate and number of CVC replacements between both periods.

RESULTS

Four patients received 19 CVCs for a total of 5623 catheter days. In the first period, there were 12 CRBSIs in 1823 catheter days (rate 6.77 per 1000 catheter days). In the second period, there were 9 CRBSIs in 3800 catheter days (rate 3.13 per 1000 catheter days). Overall, the rate of CVC replacement decreased from 4.92 to 1.72 per 1000 catheter days (p = 0.04). No adverse reactions were experienced during ethanol instillation.

CONCLUSION

Monthly prophylactic ELT for IF patients is considered to be a safe and effective modality for reducing the replacement of CVCs due to CRBSIs.

Green infrastructure and ecosystem services - is the devil in the detail?

BACKGROUND

Green infrastructure is a strategic network of green spaces designed to deliver ecosystem services to human communities. Green infrastructure is a convenient concept for urban policy makers, but the term is used too generically and with limited understanding of the relative values or benefits of different types of green space and how these complement one another. At a finer scale/more practical level, little consideration is given to the composition of the plant communities, yet this is what ultimately defines the extent of service provision. This paper calls for greater attention to be paid to urban plantings with respect to ecosystem service delivery and for plant science to engage more fully in identifying those plants that promote various services.

SCOPE

Many urban plantings are designed based on aesthetics alone, with limited thought on how plant choice/composition provides other ecosystem services. Research is beginning to demonstrate, however, that landscape plants provide a range of important services, such as helping mitigate floods and alleviating heat islands, but that not all species are equally effective. The paper reviews a number of important services and demonstrates how genotype choice radically affects service delivery.

CONCLUSIONS

Although research is in its infancy, data are being generated that relate plant traits to specific services, thereby helping identify genotypes that optimize service delivery. The urban environment, however, will become exceedingly bland if future planting is simply restricted to monocultures of a few 'functional' genotypes. Therefore, further information is required on how to design plant communities where the plants identified (1) provide more than a single benefit (multifunctionality), (B) complement each other in maximizing the range of benefits that can be delivered in one location, and (3) continue to maintain public acceptance through diversity. The identification/development of functional landscape plants is an exciting and potentially high-impact arena for plant science.

In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections

The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment.

Y-Chromosome Structural Diversity in the Bonobo and Chimpanzee Lineages

The male-specific regions of primate Y-chromosomes (MSY) are enriched for multi-copy genes highly expressed in the testis. These genes are located in large repetitive sequences arranged as palindromes, inverted-, and tandem repeats termed amplicons. In humans, these genes have critical roles in male fertility and are essential for the production of sperm. The structure of human and chimpanzee amplicon sequences show remarkable difference relative to the remainder of the genome, a difference that may be the result of intense selective pressure on male fertility. Four subspecies of common chimpanzees have undergone extended periods of isolation and appear to be in the early process of subspeciation. A recent study found amplicons enriched for testis-expressed genes on the primate X-chromosome the target of hard selective sweeps, and male-fertility genes on the Y-chromosome may also be the targets of selection. However, little is understood about Y-chromosome amplicon diversity within and across chimpanzee populations. Here, we analyze nine common chimpanzee (representing three subspecies: Pan troglodytes schweinfurthii, Pan troglodytes ellioti, and Pan troglodytes verus) and two bonobo (Pan paniscus) male whole-genome sequences to assess Y ampliconic copy-number diversity across the Pan genus. We observe that the copy number of Y chromosome amplicons is variable among chimpanzees and bonobos, and identify several lineage-specific patterns, including variable copy number of azoospermia candidates RBMY and DAZ. We detect recurrent switchpoints of copy-number change along the ampliconic tracts across chimpanzee populations, which may be the result of localized genome instability or selective forces.

Disrupted Network Topology in Patients with Stable and Progressive Mild Cognitive Impairment and Alzheimer's Disease

Recent findings suggest that Alzheimer's disease (AD) is a disconnection syndrome characterized by abnormalities in large-scale networks. However, the alterations that occur in network topology during the prodromal stages of AD, particularly in patients with stable mild cognitive impairment (MCI) and those that show a slow or faster progression to dementia, are still poorly understood. In this study, we used graph theory to assess the organization of structural MRI networks in stable MCI (sMCI) subjects, late MCI converters (lMCIc), early MCI converters (eMCIc), and AD patients from 2 large multicenter cohorts: ADNI and AddNeuroMed. Our findings showed an abnormal global network organization in all patient groups, as reflected by an increased path length, reduced transitivity, and increased modularity compared with controls. In addition, lMCIc, eMCIc, and AD patients showed a decreased path length and mean clustering compared with the sMCI group. At the local level, there were nodal clustering decreases mostly in AD patients, while the nodal closeness centrality detected abnormalities across all patient groups, showing overlapping changes in the hippocampi and amygdala and nonoverlapping changes in parietal, entorhinal, and orbitofrontal regions. These findings suggest that the prodromal and clinical stages of AD are associated with an abnormal network topology.

Compatibility of Injectable Anticoagulant Agents in Ethanol; In Vitro Antibiofilm Activity and Impact on Polyurethane Catheters of Enoxaparin 400 U/mL in 40% v/v Ethanol

Background and Objectives

Interdialytic lock solutions should maintain catheter patency and prevent catheter infections. We aimed to determine in which conditions injectable anticoagulant agents (IAAs) combined with ethanol are compatible and to assess the antibiofilm activity of the selected combination and its effects on dialysis catheters (DC).

Methods

The solubility and compatibility of unfractionated heparin (UFH), low molecular weight heparins (LMWHs), heparinoids and fondaparinux (50 to 2,500 U/mL) in 30 to 70% ethanol were determined by visual observation. The stability of enoxaparin in ethanol and the ethanol content were assessed by high performance liquid chromatography (HPLC) and titrimetric control, respectively. The bactericidal effect was determined on 24h-old biofilms embedded in silicone-DC. The integrity of polyurethane-DC immersed in anticoagulant-ethanol was assessed by gas chromatography-mass spectrometry (GC-MS) and compared with previously published results.

Results

The compatibility of IAAs and ethanol varied according to IAA type and concentration, and ethanol content. UFH in 40% ethanol was not compatible, whatever the UFH concentration used. Established limits of compatibility of enoxaparin, nadroparin, dalteparin and tinzaparin in 40% ethanol were 1350, 575, 307 and 207 U/ml, respectively, and up to 300 U/ml for danaparoid and 1 mg/mL for fondaparinux. Enoxaparin 400 U/mL in 40% ethanol (Enox/Eth) eradicated biofilm after 4 hours of exposure for Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans and after 24 hours for Klebsiella pneumoniae and S. aureus. Aliphatic carbonate and alcohol compounds were released by polyurethane-DC after Enox/Eth exposure, as after 40% ethanol or saline exposure. There was no significant difference between the amounts released after 30 minutes of exposure to Enox/Eth and 15 days to saline.

Conclusions

A 40% ethanol solution can be combined with all IAAs but UFH. Enox/Eth was effective as an anti-biofilm agent with minor impacts on DC integrity and could be a useful interdialytic lock solution.

Successful Salvage of Central Venous Catheters in Patients with Catheter-Related or Central Line-Associated Bloodstream Infections by Using a Catheter Lock Solution Consisting of Minocycline, EDTA, and 25% Ethanol

In cancer patients with long-term central venous catheters (CVC), removal and reinsertion of a new CVC at a different site might be difficult because of the unavailability of accessible vascular sites. In vitro and animal studies showed that a minocycline-EDTA-ethanol (M-EDTA-EtOH) lock solution may eradicate microbial organisms in biofilms, hence enabling the treatment of central line-associated bloodstream infections (CLABSI) while retaining the catheter in situ Between April 2013 and July 2014, we enrolled 30 patients with CLABSI in a prospective study and compared them to a historical group of 60 patients with CLABSI who had their CVC removed and a new CVC inserted. Each catheter lumen was locked with an M-EDTA-EtOH solution for 2 h administered once daily, for a total of 7 doses. Patients who received locks had clinical characteristics that were comparable to those of the control group. The times to fever resolution and microbiological eradication were similar in the two groups. Patients with the lock intervention received a shorter duration of systemic antibiotic therapy than that of the control patients (median, 11 days versus 16 days, respectively; P < 0.0001), and they were able to retain their CVCs for a median of 74 days after the onset of bacteremia. The M-EDTA-EtOH lock was associated with a significantly decreased rate of mechanical and infectious complications compared to that of the CVC removal/reinsertion group, who received a longer duration of systemic antimicrobial therapy. (This study has been registered at ClinicalTrials.gov under registration no. NCT01539343.).

Strategies to Prevent Central Line-Associated Bloodstream Infections in Acute Care Hospitals: 2014 Update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their central line-associated bloodstream infection (CLABSI) prevention efforts. This document updates “Strategies to Prevent Central Line-Associated Bloodstream Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

αB-Crystallin overexpression in astrocytes modulates the phenotype of the BACHD mouse model of Huntington's disease

Huntington's disease (HD) is caused by an expanded polyglutamine (polyQ) tract in the huntingtin (htt) protein. The polyQ expansion increases the propensity of htt to aggregate and accumulate, and manipulations that mitigate protein misfolding or facilitate the clearance of misfolded proteins are predicted to slow disease progression in HD models. αB-crystallin (αBc) or HspB5 is a well-characterized member of the small heat shock protein (sHsp) family that reduces mutant htt (mhtt) aggregation and toxicity in vitro and in Drosophila models of HD. Here, we determined if overexpressing αBc in vivo modulates aggregation and delays the onset and progression of disease in a full-length model of HD, BACHD mice. Expression of sHsps in neurodegenerative disease predominantly occurs in non-neuronal cells, and in the brain, αBc is mainly found in astrocytes and oligodendrocytes. Here, we show that directed αBc overexpression in astrocytes improves motor performance in rotarod and balance beam tests and improves cognitive function in the BACHD mice. Improvement in behavioral deficits correlated with mitigation of neuropathological features commonly observed in HD. Interestingly, astrocytic αBc overexpression was neuroprotective against neuronal cell loss in BACHD brains, suggesting αBc might be acting in a non-cell-autonomous manner. At the protein level, αBc decreased the level of soluble mhtt and decreased the size of mhtt inclusions in BACHD brain. Our results support a model in which elevating astrocytic αBc confers neuroprotection through a potential non-cell-autonomous pathway that modulates mhtt aggregation and protein levels.

The mRNA-bound proteome of the early fly embryo

Early embryogenesis is characterized by the maternal to zygotic transition (MZT), in which maternally deposited messenger RNAs are degraded while zygotic transcription begins. Before the MZT, post-transcriptional gene regulation by RNA-binding proteins (RBPs) is the dominant force in embryo patterning. We used two mRNA interactome capture methods to identify RBPs bound to polyadenylated transcripts within the first 2 h of Drosophila melanogaster embryogenesis. We identified a high-confidence set of 476 putative RBPs and confirmed RNA-binding activities for most of 24 tested candidates. Most proteins in the interactome are known RBPs or harbor canonical RBP features, but 99 exhibited previously uncharacterized RNA-binding activity. mRNA-bound RBPs and TFs exhibit distinct expression dynamics, in which the newly identified RBPs dominate the first 2 h of embryonic development. Integrating our resource with in situ hybridization data from existing databases showed that mRNAs encoding RBPs are enriched in posterior regions of the early embryo, suggesting their general importance in posterior patterning and germ cell maturation.

Anti-biofilm Activity as a Health Issue

The formation and persistence of surface-attached microbial communities, known as biofilms, are responsible for 75% of human microbial infections (National Institutes of Health). Biofilm lifestyle confers several advantages to the pathogens, notably during the colonization process of medical devices and/or patients’ organs. In addition, sessile bacteria have a high tolerance to exogenous stress including anti-infectious agents. Biofilms are highly competitive communities and some microorganisms exhibit anti-biofilm capacities such as bacterial growth inhibition, exclusion or competition, which enable them to acquire advantages and become dominant. The deciphering and control of anti-biofilm properties represent future challenges in human infection control. The aim of this review is to compare and discuss the mechanisms of natural bacterial anti-biofilm strategies/mechanisms recently identified in pathogenic, commensal and probiotic bacteria and the main synthetic strategies used in clinical practice, particularly for catheter-related infections.