Amine Basicity of Quinoline ATP Synthase Inhibitors Drives Antibacterial Activity against Pseudomonas aeruginosa.

Pseudomonas aeruginosa (PA), a Gram-negative pathogen, is a common cause of nosocomial infections, especially in immunocompromised and cystic fibrosis patients. PA is intrinsically resistant to many currently prescribed antibiotics due to its tightly packed, anionic lipopolysaccharide outer membrane, efflux pumps, and ability to form biofilms. PA can acquire additional resistance through mutation and horizontal gene transfer. PA ATP synthase is an attractive target for antibiotic development because it is essential for cell survival even under fermentation conditions. Previously, we developed two lead quinoline compounds that were capable of selectively inhibiting PA ATP synthase and acting as antibacterial agents against multidrug-resistant PA. Herein we conduct a structure-activity relationship analysis of the lead compounds through the synthesis and evaluation of 18 quinoline derivatives. These compounds function as new antibacterial agents while providing insight into the balance of physical properties needed to promote cellular entry while maintaining PA ATP synthase inhibition.

Quinoline Compounds Targeting the c-Ring of ATP Synthase Inhibit Drug-Resistant Pseudomonas aeruginosa.

Pseudomonas aeruginosa (PA) is a Gram-negative, biofilm-forming bacterium and an opportunistic pathogen. The growing drug resistance of PA is a serious threat that necessitates the discovery of novel antibiotics, ideally with previously underexplored mechanisms of action. Due to their central role in cell metabolism, bacterial bioenergetic processes are of increasing interest as drug targets, especially with the success of the ATP synthase inhibitor bedaquiline to treat drug-resistant tuberculosis. Like Mycobacterium tuberculosis, PA requires F1Fo ATP synthase for growth, even under anaerobic conditions, making the PA ATP synthase an ideal drug target for the treatment of drug-resistant infection. In previous work, we conducted an initial screen for quinoline compounds that inhibit ATP synthesis activity in PA. In the present study, we report additional quinoline derivatives, including one with increased potency against PA ATP synthase in vitro and antibacterial activity against drug-resistant PA. Moreover, by expressing the PA ATP synthase in Escherichia coli, we show that mutations in the H+ binding site on the membrane-embedded rotor ring alter inhibition by the reported quinoline compounds. Identification of a potent inhibitor and its probable binding site on ATP synthase enables further development of promising quinoline derivatives into a viable treatment for drug-resistant PA infection.

Bisbenzamidine and Bisbenzguanidine Ureas Act as Antibacterial Agents against Pseudomonas aeruginosa.

Due to the global rise in the number of antibiotic resistant bacterial infections over the past 20 years, there is a dire need for the development of small molecule antibiotics capable of overcoming resistance mechanisms in pathogenic bacteria. Antibiotic development against Gram-negative pathogens, such as Pseudomonas aeruginosa, is especially challenging due to their additional outer membrane which reduces antibiotic entry. Recently, it has been shown that a broad range of nitrogen functionality, including guanidines, amidines, primary amines, imidazolines, and imidazoles, promote antibiotic and adjuvant activity in Gram-negative bacteria, but few of these have been targeted towards Pseudomonas aeruginosa specifically despite this pathogen being deemed a critical threat by the United States Centers for Disease Control and Prevention. Herein, we examined a small series of known and unknown nitrogenous dimers, with guanidine, amidine, dimethyl amine, and pyridine functionality, for antibacterial activity against multidrug resistant Pseudomonas aeruginosa. We found that two, with bisbenzguanidine and bisbenzamidine functionality, are potent against clinical isolates of multidrug resistant and biofilm forming Pseudomonas aeruginosa.

Generating Publishable Data from Course-Based Undergraduate Research Experiences in Chemistry.

Embedding Course-based Undergraduate Research Experiences (CUREs) into chemistry curricula has become a best practice due to the overwhelming evidence that these experiences deepen students' content comprehension, improve students' problem-solving skills, and increase retention within the major. For these reasons, faculty are often encouraged to develop CUREs for their courses, which typically take a substantial amount of effort and administrative/financial support. To justify these efforts, one of the most cited benefits of CURE development for faculty specifically is that they can pilot research projects and publish data produced during CUREs in scientific publications. However, there is less evidence in the literature that these benefits commonly occur. Based on direct upper-level, interdisciplinary CURE development experience and a national survey of faculty across institution types, it is clear that translating CURE data into publishable science is quite challenging due to several common barriers. Barriers identified include the need for follow up data that must be generated by either the faculty or a research student, the lack of reproducibility of data generated by novice students, and the lack of faculty time to write the manuscripts. Additionally, institution type (private vs public non-PhD granting; non-PhD granting vs PhD granting), faculty rank, and CURE level (lower vs upper-level courses), among other factors, impacted the likelihood of publication of CURE data. Based on these results and experiences, best practices for maximizing positive outcomes for both students and faculty with regard to CURE design and implementation have been developed.

Integration of Antimicrobials and Delivery Systems: Synergistic Antibiofilm Activity with Biodegradable Nanoemulsions Incorporating Pseudopyronine Analogs.

Multi-drug-resistant (MDR) bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), pose a significant challenge in healthcare settings. Small molecule antimicrobials (SMAs) such as α-pyrones have shown promise as alternative treatments for MDR infections. However, the hydrophobic nature of many SMAs limits their solubility and efficacy in complex biological environments. In this study, we encapsulated pseudopyronine analogs (PAs) in biodegradable polymer nanoemulsions (BNEs) for efficient eradication of biofilms. We evaluated a series of PAs with varied alkyl chain lengths and examined their antimicrobial activity against Gram-positive pathogens (S. aureus, MRSA, and B. subtilis). The selected PA with the most potent antibiofilm activity was incorporated into BNEs for enhanced solubility and penetration into the EPS matrix (PA-BNEs). The antimicrobial efficacy of PA-BNEs was assessed against biofilms of Gram-positive strains. The BNEs facilitated the solubilization and effective delivery of the PA deep into the biofilm matrix, addressing the limitations of hydrophobic SMAs. Our findings demonstrated that the PA2 exhibited synergistic antibiofilm activity when it was loaded into nanoemulsions. This study presents a promising platform for addressing MDR infections by combining pseudopyronine analogs with antimicrobial biodegradable nanoemulsions, overcoming challenges associated with treating biofilm infections.

Design and evaluation of poly-nitrogenous adjuvants capable of potentiating antibiotics in Gram-negative bacteria.

Antibiotic resistance has been a growing public health crisis since the 1980s. Therefore, it is essential not only to continue to develop novel antibiotics but also to develop new methods for overcoming resistance mechanisms in pathogenic bacteria so antibiotics can be reactivated towards these resistant strains. One common cause of antibiotic resistance in Gram-negative bacteria is reduced permeability of the tightly packed, negatively charged lipopolysaccharide outer membrane (OM), which dramatically reduces or even prevents antibiotic accumulation within the cell. Adjuvants that promote passive diffusion through the OM, including phenylalanine-arginine-ß-naphthylamide, tobramycin, and pentamidine, have proven useful in potentiating antibiotics against Gram-negative bacteria. Structural evaluation of these adjuvants, which all include multiple nitrogenous groups, indicates that the entry rules developed for improving antibiotic accumulation in Escherichia coli (EC), could also be used to guide adjuvant development. To this end, a series of structurally simple poly-nitrogenous diphenylsuccinamide compounds have been prepared and evaluated for their ability to potentiate a panel of classic antibiotics in wild-type EC and Pseudomonas aeruginosa (PA). Modest adjuvant activity was observed for all compounds surveyed when co-administered with known antibiotics to inhibit either wild-type EC or PA, and all were able to accumulate in both EC and PA.

Synthesis and Evaluation of Pseudomonas aeruginosa ATP Synthase Inhibitors.

New antibiotics with unique biological targets are desperately needed to combat the growing number of resistant bacterial pathogens. ATP synthase, a critical protein found in all life, has recently become a target of interest for antibiotic development due to the success of the anti-tuberculosis drug bedaquiline, and while many groups have worked on developing drugs to target bacterial ATP synthase, few have been successful at inhibiting Pseudomonas aeruginosa (PA) ATP synthase specifically. PA is one of the leading causes of resistant nosocomial infections across the world and is extremely challenging to treat due to its various antibiotic resistance mechanisms for most commonly used antibiotics. Herein, we detail the synthesis and evaluation of a series of C1/C2 quinoline analogues for their ability to inhibit PA ATP synthase and act as antibiotics against wild-type PA. From this survey, we found six compounds capable of inhibiting PA ATP synthase in vitro showing that bulky/hydrophobic C1/C2 substitutions are preferred. The strongest inhibitor showed an IC50 of 10 µg/mL and decreased activity of PA ATP synthase to 24% relative to the control. While none of the compounds were able to inhibit wild-type PA in cell culture, two showed improved inhibition of PA growth when permeability of the outer membrane was increased or efflux was knocked out, thus demonstrating that these compounds could be further developed into efficacious antibiotics.

Total synthesis and antibacterial evaluation of Empetroxepins A and B and related analogs.

Empetroxepins A and B, which are 10,11-dihydrodibenz[b,f]oxepins produced by the Black Crowberry (Empetrum nigrum), displayed weak anti-tubercular activity upon isolation, but have not been explored for antibiotic activity despite their molecular similarity to other phenolic antibacterial natural products. Herein we detail the first total synthesis of Empetroxepins A and B via a selective demethylation strategy and antibacterial structure activity relationship (SAR) study of the natural products and related analogs. Empetroxepin A was found to be weakly active against susceptible strains of Staphylococcus aureus (SA) and Bacillus subtilis (BS) with a minimum inhibitory concentration (MIC) of 256 µg/mL against both bacteria, whereas Empetroxepin B was found to be weakly active against only BS (MIC = 256 µg/mL). Neither natural product was active against Escherichia coli (EC). Antibiotic activity was improved through derivatization of the 10,11-dihydrodibenz[b,f]oxepin core with the best compound of the SAR series, 9-chloro-10,11-dihydrodibenzo[b,f]oxepine-2,3,4-triol, having MICs of 8 µg/mL, 16 µg/mL, and 256 µg/mL against SA, BS, and EC respectively.

Antifungal Resistance and the Role of New Therapeutic Agents.

Purpose of Review: Advances in health care over time have led to an evolution in the epidemiology of invasive fungal infections. There is an increasing concern for antifungal resistance and emergence of less common fungal species for which optimal therapies are not well defined. The purpose of this review is to describe mechanisms of antifungal resistance and to evaluate the modern role of new and investigational antifungals. Recent Findings: Isavuconazole and ibrexafungerp represent the two newest antifungal agents. Evidence from in vivo and in vitro studies has been published recently to help define their place in therapy and potential roles in treating resistant fungi. Isavuconazole is a broad-spectrum triazole antifungal with evidence to support its use in invasive aspergillosis and mucormycosis. Its utility in treating voriconazole-resistant Candida should be confirmed with susceptibility testing if available. Ibrexafungerp is an oral glucan synthase inhibitor with little cross-resistance among currently available antifungals, including echinocandins. It is a promising new agent for invasive candidiasis, including azole-resistant Candida species, and in combination therapy with voriconazole for aspergillosis. Multiple antifungals, some with novel mechanisms, are in development, including rezafungin, oteseconazole, olorofim, fosmanogepix, and opelconazole. Summary: Both isavuconazole and ibrexafungerp are welcome additions to the arsenal of antifungals, and the prospect of more antifungal options in the future is encouraging. Such an array of antifungals will be important as antifungal resistance continues to expand alongside evolving medical practices. However, managing resistant fungal infections will grow in complexity as the unique role of each new agent is defined.

Assessing Nephrotoxicity Associated With Different Vancomycin Dosing Modalities in Obese Patients at a Community Hospital.

Background: Vancomycin requires therapeutic drug monitoring (TDM) based on its pharmacokinetic properties, and guidelines have shifted to analyzing area under the curve over 24 hours (AUC24) rather than trough concentrations due to nephrotoxicity concerns and correlation to efficacy. Obesity is an established risk factor for vancomycin-induced nephrotoxicity due to increased drug exposure based on dosing calculations and volume of distribution estimation. The aim of this study is to assess the relationship between AUC-based versus trough-based dosing and nephrotoxicity among obese patients receiving vancomycin. Methods: This research project was conducted as a retrospective, observational, single-centered study which included obese adults who received at least 48 hours of vancomycin. The electronic medical record provided data for patients with vancomycin pharmacokinetic consults either evaluated with trough-only or AUC-based dosing. The primary objective was to compare the development of nephrotoxicity after vancomycin initiation, while secondary objectives included vancomycin loading dose exposure, total daily dose of vancomycin, and whether target TDM was attained. Nominal data were evaluated utilizing the chi-square test and continuous data using the independent samples t-test or Mann-Whitney test. The a priori level of significance was .05. Data analysis was performed using Microsoft Excel and SAS statistical software. Results: Two hundred fifty-four patients were included in the primary analysis. Four patients in the AUC cohort (6.3%) developed nephrotoxicity compared to 32 (17.4%) in the trough cohort (P = .035). Both cohorts received a median of 4 days of therapy; however, the median loading dose per actual body weight in the AUC cohort was 20 mg/kg as compared to 16 mg/kg in the trough cohort. Of the 130 patients with available TDM in the trough cohort, 97 (74.6%) did not meet target attainment as compared to 15 of the 57 in the AUC cohort (26.3%) (P < .001). Conclusions: AUC dosing was associated with a statistically significant reduction in AKI occurrence despite overall higher loading dose exposure as compared to the trough cohort. Though maintenance dose exposure was similar between both cohorts, patients in the AUC cohort maintained therapeutic concentrations at a higher percentage than the trough cohort.

Use and Discontinuation of Milrinone for Advanced Heart Failure in an Academic Palliative Care Unit: A Case Report and Discussion of Recommendations.

The use of intravenous inotropic medications in advanced heart failure (HF) has been shown to improve symptoms and decrease hospitalizations, prompting support for their use as a palliative measure for symptom management. Recommendations regarding inotrope management and method of discontinuation at the end of life are not specifically detailed in the literature and current guidelines. This case report describes the use of milrinone in a patient with advanced HF during the terminal phase of illness in a non-monitored palliative care unit setting, including dose reduction and discontinuation of milrinone. Increased patient anxiety during the weaning process was managed with midazolam. The provision of individualized milrinone therapy in non-monitored palliative care settings is feasible and well-tolerated using the presented detailed recommendations for its use and administration, monitoring, dose reduction and discontinuation and proactive symptom management at the end of life. Further research is needed for the optimal management of terminally ill patients with advanced HF.Supplemental data for this article is available online at here. show.

Stability of Dexmedetomidine in Polyvinyl Chloride Bags Containing 0.9% Sodium Chloride Intended for Subcutaneous Infusions.

Dexmedetomidine is a sedative medication with co-analgesic effects that has been used primarily in critical care and anesthesia as a continuous intravenous infusion. Its utility in the treatment of refractory agitated delirium is being investigated in other settings including palliative care, but continuous intravenous infusions are not always feasible during end-of-life care. Subcutaneous infusions are more commonly used in this setting, but smaller volumes and higher concentrations are typically required. Investigations into stability at these higher concentrations are required to address preparation and administration feasibility issues. The objective of this research was to study the chemical stability of high-concentration dexmedetomidine 20 mcg/mL prepared in polyvinyl chloride bags with 0.9% sodium chloride and storage up to 9 days under refrigeration and room temperature conditions. A total of four solutions of dexmedetomidine 20 mcg/mL in 0.9% sodium chloride were prepared in polyvinyl chloride bags under sterile conditions. Two bags were stored under refrigeration and two bags at room temperature. Duplicate samples were withdrawn from each bag at hours 0, 24, 48, 72, 96, 120, 144, 168, 192, and 216 and frozen at -20°C (total of 4 samples per time point at each storage condition). These samples were thawed and transferred to glass vials prior to their analysis by high-performance liquid chromatography electrospray ionization-tandem mass spectrometry and pH testing. All samples of dexmedetomidine 20 mcg/mL met stability criteria by retaining more than 90% of the initial concentration after 9 days under refrigeration and room temperature. There was no evidence of precipitation or color change during the study period. The pH reduced slightly over time under both refrigerated (5.7 to 4.5) and room temperature conditions (5.7 to 4.6). Dexmedetomidine solutions of 20 mcg/mL intended for subcutaneous use were stable in polyvinyl chloride bags containing 0.9% sodium chloride for 9 days under refrigeration and room temperature.

Advances in antibiotic drug discovery: reducing the barriers for antibiotic development.

Antibiotic drug discovery has been an essential field of research since the early 1900s, but the threat from infectious bacteria has only increased over the decades because of the emergence of widespread multidrug resistance. In this review, we discuss the recent advances in natural product, computational and medicinal chemistry that have reinvigorated the field of antibiotic drug discovery while giving perspective on how easily, both in cost and in expertise, these methods can be implemented by other researchers with the goal of increasing the number of scientists contributing to this public health crisis.

Short chain α-pyrones capable of potentiating penicillin G against Pseudomonas aeruginosa.

The dramatic increase in bacterial resistance over the past three decades has greatly reduced the effectiveness of nearly all clinical antibiotics, bringing infectious disease to the forefront as a dire threat to global health. To combat these infections, adjuvant therapies have emerged as a way to reactivate known antibiotics against resistant pathogens. Herein, we report the evaluation of simplified α-pyrone adjuvants capable of potentiating penicillin G against Pseudomonas aeruginosa, a Gram-negative pathogen whose multidrug-resistant strains have been labeled by the Centers for Disease Control and Prevention as a serious threat to public health.

Association of Common Genetic Variants in the CPSF7 and SDHAF2 Genes with Canine Idiopathic Pulmonary Fibrosis in the West Highland White Terrier.

Canine idiopathic pulmonary fibrosis (CIPF) is a chronic fibrotic lung disease that is observed at a higher frequency in the West Highland White Terrier dog breed (WHWT) and may have molecular pathological overlap with human lung fibrotic disease. We conducted a genome-wide association study (GWAS) in the WHWT using whole genome sequencing (WGS) to discover genetic variants associated with CIPF. Saliva-derived DNA samples were sequenced using the Riptide DNA library prep kit. After quality controls, 28 affected, 44 unaffected, and 1,843,695 informative single nucleotide polymorphisms (SNPs) were included in the GWAS. Data were analyzed both at the single SNP and gene levels using the GEMMA and GATES methods, respectively. We detected significant signals at the gene level in both the cleavage and polyadenylation specific factor 7 (CPSF7) and succinate dehydrogenase complex assembly factor 2 (SDHAF2) genes (adjusted p = 0.016 and 0.024, respectively), two overlapping genes located on chromosome 18. The top SNP for both genes was rs22669389; however, it did not reach genome-wide significance in the GWAS (adjusted p = 0.078). Our studies provide, for the first time, candidate loci for CIPF in the WHWT. CPSF7 was recently associated with lung adenocarcinoma, further highlighting the potential relevance of our results because IPF and lung cancer share several pathological mechanisms.

Clinical outcomes and transfusion management following intracranial hemorrhage in patients with acute leukemia.

BACKGROUND: There is little evidence to guide management of patients with acute leukemia and intracranial hemorrhage (ICH). Predictors of long-term outcome following ICH are unknown. STUDY DESIGN AND METHODS: This study included adult patients with acute leukemia and ICH over an 8-year period. The primary outcome was data regarding 90-day mortality. Secondary outcomes included data related to the proportion of patients receiving post-remission therapy and predictors of 90-day mortality. RESULTS: ICH occurred in 101 patients; 12 patients died within 72 hours. For the 89 others, 90-day mortality was 40%. Of 43 patients who received induction, 30 achieved remission and 26 received post-remission therapy. Older age (p = 0.03) and higher white count (p = 0.02) at the time of ICH were predictive of inferior survival. During 90-day follow-up, median platelet count was 37 x 109 /L (0-1526 x 109 /L). Lower platelet count during follow-up was predictive of 90-day mortality (p = <0.01). Twenty-one percent of platelet transfusions were provided when the platelet count was less than 10 x 109 /L, 54% between 10 and 29 x 109 /L, and 25% greater than 30 x 109 /L. New or progressive ICH occurred in 23 patients. There was no difference in the median platelet transfusion trigger between patients who had new or progressive ICH and those who did not. CONCLUSION: In patients with acute leukemia, survival following ICH is poor. Older age and higher white count is associated with increased mortality, perhaps reflecting higher risk disease. Following ICH in acute leukemia platelet transfusions do not appear to alter the risk of progressive bleeding or mortality.

Clinical Interventions to Prevent Tumour Lysis Syndrome in Hematologic Malignancy: A Multisite Retrospective Chart Review.

BACKGROUND: Tumour lysis syndrome (TLS) occurs when lysis of malignant cells causes electrolyte disturbances and potentially organ dysfunction. Guidelines recommending preventive therapy according to TLS risk are based on low-quality evidence. OBJECTIVES: The primary objective was to characterize utilization of TLS preventive strategies through comprehensive description of current practice. Secondary objectives were to determine TLS incidence, to compare use of preventive strategies among intermediate- and high-risk patients, and to describe TLS treatment strategies. METHODS: This retrospective chart review examined data for patients with newly diagnosed hematologic malignancy who were admitted to an oncology centre and/or affiliated intensive care unit between October 2015 and September 2016 in Toronto, Ontario, Canada. RESULTS: Fifty-eight patients (29 at intermediate risk, 29 at high risk) were eligible for inclusion. Use of preventive allopurinol, IV bicarbonate, and furosemide was similar between groups. Rasburicase was more frequently used for high-risk patients (3% [1/29] of intermediate-risk patients versus 36% [9/25] of high-risk patients; p = 0.003). In 4 (14%) of the intermediate-risk patients and 2 (8%) of the high-risk patients, TLS developed during the admission. TLS was observed in 10% (1/10) of patients who received preventive rasburicase and 11% (5/44) of those who did not (p > 0.99), and in 9% (4/45) of patients who received preventive IV bicarbonate and 25% (2/8) of those who did not (p = 0.22). Treatment strategies included rasburicase, IV bicarbonate, furosemide, and renal replacement therapy. CONCLUSIONS: In this retrospective chart review, rasburicase was more commonly used for high-risk patients, whereas the use of other agents was similar between risk groups. This pattern of use is inconsistent with guidelines, which recommend that all high-risk patients receive rasburicase. There was no difference in TLS incidence between patients who did and did not receive preventive rasburicase or IV bicarbonate. Further prospective studies are needed to inform management of patients with malignancies who are at intermediate or high risk of TLS.

CONTEXTE: Le syndrome de lyse tumorale (SLT) se produit lorsque la lyse de cellules malignes provoque des perturbations électrolytiques et la dysfonction potentielle d'un organe. Les lignes directrices préconisant une thérapie préventive basée sur le risque de SLT se fondent sur des éléments de preuve de piètre qualité. OBJECTIFS: L'objectif principal consistait à décrire l'adoption des stratégies de prévention du SLT en décrivant précisément la pratique actuelle. Les objectifs secondaires consistaient, quant à eux, à déterminer l'incidence du SLT, à comparer l'utilisation des stratégies de prévention pour les patients présentant un risque élevé et moyen et à décrire les stratégies de traitement du SLT. MÉTHODES: Cet examen rétrospectif a permis d'examiner les données de patients ayant récemment reçu un diagnostic d'hémopathie maligne et ayant été admis dans un centre d'oncologie ou une unité de soins intensifs affiliée, entre octobre 2015 et septembre 2016 à Toronto (Ontario), au Canada. RÉSULTATS: Cinquante-huit patients (29 présentant un risque moyen et 29 un risque élevé) étaient admissibles. L'utilisation d'allopurinol à titre préventif, de bicarbonate par voie intraveineuse et de furosémide était similaire d'un groupe à l'autre. Le rasburicase était plus fréquemment utilisé pour les patients présentant un risque élevé (3 % [1/29] de patients présentant un risque moyen contre 36 % [9/25] de patients présentant un risque élevé; p = 0.003). Quatre (14 %) patients présentant un risque moyen et deux (8 %) présentant un risque élevé ont développé un SLT pendant l'admission. Le SLT a été observé chez 10 % (1/10) des patients ayant reçu du rasburicase à titre préventif et chez 11 % (5/44) des patients qui n'en avaient pas reçu (p > 0,99); il a aussi été observé chez 9 % (4/45) des patients ayant reçu du bicarbonate par voie intraveineuse à titre préventif et chez 25 % (2/8) des patients qui n'en avaient pas reçu (p = 0.22). Les stratégies de traitement comprenaient le rasburicase, le bicarbonate par voie intraveineuse, le furosémide et la thérapie de remplacement rénal. CONCLUSIONS: Dans cet examen rétrospectif des dossiers, l'usage du rasburicase était plus fréquent pour les patients présentant un risque élevé, tandis que celui d'autres agents était similaire entre les groupes à risque. Ce schéma d'utilisation n'est pas conforme aux lignes directrices, qui recommandent que tous les patients présentant un risque élevé reçoivent du rasburicase. Aucune différence n'est apparue dans l'incidence du SLT parmi les patients ayant reçu du rasburicase ou du bicarbonate par voie intraveineuse à titre préventif et parmi ceux qui n'en avaient pas reçu. Davantage d'études prospectives sont nécessaires pour mieux connaitre la gestion des patients à haut risque ou ceux qui présentent des risques moyens de SLT, mais qui ont des malignités.

Development of a Robust and Quantitative High-Throughput Screening Method for Antibiotic Production in Bacterial Libraries.

Over the past 30 years, there has been a dramatic rise in the number of infections caused by multidrug-resistant bacteria, which have proliferated due to the misuse and overuse of antibiotics. Over this same time period, however, there has also been a decline in the number of antibiotics with novel mechanisms of action coming to market. Therefore, there is a growing need for an increase in the speed at which new antibiotics are discovered and developed. Natural products produced by bacteria have been and continue to be a robust source of novel antibiotics; however, new and complementary methods for screening large bacterial libraries for novel antibiotic production are needed due to the current agar methods being limited in scope, time consuming, and prone to error. Herein, we describe a rapid, robust, and quantitative high-throughput liquid culture screening method for antibiotic production by bacteria. This method has the ability to screen both mono- and coculture mixtures of bacteria in vitro and be adapted to other phenotypic natural product analyses. Over 260 bacterial species were screened in monoculture, and 38 and 34% were found to produce antibiotics capable of inhibition of Staphylococcus aureus or Escherichia coli, respectively, with 8 and 4% being classified as strong producers (≥30% growth inhibition), respectively. Bacteria found to not produce antibiotics in monoculture were also screened in coculture using an adaptation of this method. Of the more than 270 cocultures screened, 14 and 30% were found to produce antibiotics capable of inhibition of S. aureus or E. coli, respectively. Of those bacteria found to produce antibiotics in monoculture, 43 bacteria were subjected to 16S rRNA sequencing and found to be majority Pseudomonas (37%), Serratia (19%), and Bacillus (14%) bacteria, but two novel producers, Herbaspirillum and Kluyvera, were also found.

Using the device-oriented subjective outcome (DOSO) scale to measure outcomes of different hearing aids.

OBJECTIVE: The device-oriented subjective outcome (DOSO) is a device-oriented questionnaire, intended to minimise the influence of personality on self-reported measures. The aim of this study was to provide normative data with 2015-era hearing aid technologies. DESIGN: This retrospective study evaluated data from records of three clinical trials. The DOSO was administered for the participants' own devices as a part of the intake and after using research devices in the field. STUDY SAMPLE: The DOSO data were collected from 132 experienced bilateral hearing aid wearers who participated in the clinical trials. RESULTS: The DOSO data collected with the participants' own devices were compared to the interim normative data collected between 2004 and 2005. The DOSO subscale scores from the participants' own devices were significantly higher than those from the interim norms, except Listening Effort subscale. To demonstrate the utility of the new norms, a separate set of DOSO data collected from the same participants after using research hearing aids were contrasted to the new normative data. After accounting for possible placebo effects, the DOSO data with research devices revealed additional self-reported benefit of technological advancements. CONCLUSIONS: Norms for the DOSO are recommended for evaluating hearing aids with more recent technologies.

Transcriptome response of human skeletal muscle to divergent exercise stimuli.

Aerobic (AE) and resistance exercise (RE) elicit unique adaptations in skeletal muscle that have distinct implications for health and performance. The purpose of this study was to identify the unique transcriptome response of skeletal muscle to acute AE and RE. In a counterbalanced, crossover design, six healthy, recreationally active young men (27 ± 3 yr) completed acute AE (40 min of cycling, ∼70% maximal HR) and RE [8 sets, 10 reps, ∼65% 1-repetition maximum (1RM)], separated by ∼1 wk. Muscle biopsies (vastus lateralis) were obtained before and at 1 and 4 h postexercise. Whole transcriptome RNA sequencing (HiSeq2500; Illumina) was performed on cDNA synthesized from skeletal muscle RNA. Sequencing data were analyzed using HTSeq, and differential gene expression was identified using DESeq2 [adjusted P value (FDR) <0.05, >1.5-fold change from preexercise]. RE resulted in a greater number of differentially expressed genes at 1 (67 vs. 48) and 4 h (523 vs. 221) compared with AE. We identified 348 genes that were differentially expressed only following RE, whereas 48 genes were differentially expressed only following AE. Gene clustering indicated that AE targeted functions related to zinc interaction, angiogenesis, and ubiquitination, whereas RE targeted functions related to transcription regulation, cytokine activity, cell adhesion, kinase activity, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. ESRRG and TNFSRF12A were identified as potential targets related to the specific response of skeletal muscle to AE and RE, respectively. These data describe the early postexercise transcriptome response of skeletal muscle to acute AE and RE and further highlight that different forms of exercise stimulate unique molecular activity in skeletal muscle. NEW & NOTEWORTHY Whole transcriptome RNA sequencing was used to determine the early postexercise transcriptome response of skeletal muscle to acute aerobic (AE) and resistance exercise (RE) in untrained individuals. Although a number of shared genes were stimulated following both AE and RE, several genes were uniquely responsive to each exercise mode. These findings support the need for future research focused to better identify the role of exercise mode as it relates to targeting specific cellular skeletal muscle abnormalities.