Development of an orally bioavailable mSWI/SNF ATPase degrader and acquired mechanisms of resistance in prostate cancer.

Mammalian switch/sucrose nonfermentable (mSWI/SNF) ATPase degraders have been shown to be effective in enhancer-driven cancers by functioning to impede oncogenic transcription factor chromatin accessibility. Here, we developed AU-24118, an orally bioavailable proteolysis-targeting chimera (PROTAC) degrader of mSWI/SNF ATPases (SMARCA2 and SMARCA4) and PBRM1. AU-24118 demonstrated tumor regression in a model of castration-resistant prostate cancer (CRPC) which was further enhanced with combination enzalutamide treatment, a standard of care androgen receptor (AR) antagonist used in CRPC patients. Importantly, AU-24118 exhibited favorable pharmacokinetic profiles in preclinical analyses in mice and rats, and further toxicity testing in mice showed a favorable safety profile. As acquired resistance is common with targeted cancer therapeutics, experiments were designed to explore potential mechanisms of resistance that may arise with long-term mSWI/SNF ATPase PROTAC treatment. Prostate cancer cell lines exposed to long-term treatment with high doses of a mSWI/SNF ATPase degrader developed SMARCA4 bromodomain mutations and ABCB1 (ATP binding cassette subfamily B member 1) overexpression as acquired mechanisms of resistance. Intriguingly, while SMARCA4 mutations provided specific resistance to mSWI/SNF degraders, ABCB1 overexpression provided broader resistance to other potent PROTAC degraders targeting bromodomain-containing protein 4 and AR. The ABCB1 inhibitor, zosuquidar, reversed resistance to all three PROTAC degraders tested. Combined, these findings position mSWI/SNF degraders for clinical translation for patients with enhancer-driven cancers and define strategies to overcome resistance mechanisms that may arise.

Novel MoS2-In2O3-WS2 (2D/3D/2D) ternary heterostructure nanocomposite material: Efficient photocatalytic degradation of antimicrobial agents under visible-light.

Fabrication of ternary composited photocatalytic nanomaterials with strong interaction is vital to deriving the fast charge separation for efficient photodegradation of organic contaminants in wastewater under visible light. In this work, novel ternary 2D/3D/2D MoS2-In2O3-WS2 multi-nanostructures were synthesized using facile hydrothermal processes. XRD, FTIR, and XPS results confirmed the phase, functional groups, and element composition of pure MoS2, MoS2-In2O3, and MoS2-In2O3-WS2 hybrids. UV-DRS spectra of the MoS2-In2O3-WS2 ternary hybrid indicate maximum absorption in the visible light range with a band-gap energy value of 2.4 eV. The surface of the 2D WS2 nanosheet structure tightly blends and densely disperses 2D MoS2 nanosheets and 3D In2O3 nanocubes. This confirmed the formation of the MoS2-In2O3-WS2 ternary hybrid in the form of 2D/3D/2D multi-nanostructures, which is also indicated from SEM and HR-TEM images. The synthesized MoS2-In2O3-WS2 ternary hybrid showed maximum photocatalytic activity under visible-light for antimicrobial agents such as triclosan (TCS) and trichlorocarban (TCC). The photocatalytic activity of TCS was revealed to be 95% at 90 min, while that of TCC was 93% at 100 min. The reusability and stability tests of the prepared MoS2-In2O3-WS2 ternary hybrid after four consecutive photocatalytic cycles were analyzed by FTIR and SEM, which indicated that the prepared ternary hybrid was very stable. Overall results suggested that the developed MoS2-In2O3-WS2 (2D/3D/2D) multi-nanostructures are environmentally friendly and low-cost nanocomposites as a potential photocatalyst for the removal of antimicrobial agents from wastewater.

Density functional theory study of the structure, stability, magnetic properties, and (hyper)polarizability of (sub-nm) rare-earth (RE) doped gold clusters: Au5RE with RE = Sc, Y, La-Lu.

Rare-earth doped materials are of immense interest for their potential applications in linear and nonlinear photonics. There is also intense interest in sub-nanometer gold clusters due to their enhanced stability and unique optical, magnetic, and catalytic properties. To leverage their emergent properties, here we report a systematic study of the geometries, stability, electronic, magnetic, and linear and nonlinear optical properties of Au5RE (RE = Sc, Y, La-Lu) clusters using density-functional theory. Several low-energy isomers consisting of planar or non-planar configurations are identified. For most doped clusters, the non-planar configuration is energetically favored. In the case of La-, Pm-, Gd-, and Ho-doped clusters, a competition between planar and non-planar isomers is predicted. A distinct preference for the planar configuration is predicted for Au5Eu, Au5Sm, Au5Tb, Au5Tm, and Au5Yb. The distinction between the planar and non-planar configurations is highlighted by the calculated highest frequencies, with the stretching mode of the non-planar configuration predicted to be stiffer than the planar configuration. The bonding analysis reveals the dominance of the RE-d orbitals in the formation of frontier molecular orbitals, which, in turn, facilitates retaining the magnetic characteristics governed by RE-f orbitals, preventing spin-quenching of rare earths in the doped clusters. In addition, the doped clusters exhibit small energy gaps between frontier orbitals, large dipole moments, and enhanced hyperpolarizability compared to the host cluster.

A comparison of rapid cycle deliberate practice and traditional reflective debriefing on interprofessional team performance.

BACKGROUND: In simulation-based education, debriefing is necessary to promote knowledge acquisition and skill application. Rapid Cycle Deliberate Practice (RCDP) and Traditional Reflective Debriefing (TRD) are based in learning theories of deliberate practice and reflective learning, respectively. In this study, we compared the effectiveness of TRD versus RCDP on acquisition of conceptual knowledge and teamwork skills among interdisciplinary learners in the pediatric emergency department. METHODS: One hundred sixty-four learners including emergency department attending physicians, fellows, nurses, medical technicians, paramedics, and respiratory therapists, participated in 28 in-situ simulation workshops over 2 months. Groups were quasi-randomized to receive RCDP or TRD debriefing. Learners completed a multiple-choice test to assess teamwork knowledge. The TEAM Assessment Tool assessed team performance before and after debriefing. Primary outcomes were teamwork knowledge and team performance. RESULTS: Average pre-intervention baseline knowledge assessment scores were high in both groups (TRD mean 90.5 (SD 12.7), RCDP mean 88.7 (SD 15.5). Post-test scores showed small improvements in both groups (TRD mean 93.2 (SD 12.2), RCDP mean 89.9 (SD 13.8), as indicated by effect sizes (ES = 0.21 and 0.09, for TRD and RCDP, respectively). Assessment of team performance demonstrated a significant improvement in mean scores from pre-assessment to post-assessment for all TEAM Assessment skills in both TRD and RCDP arms, based on p-values (all p < 0.01) and effect sizes (all ES > 0.8). While pre-post improvements in TEAM scores were generally higher in the RCDP group based on effect sizes, analysis did not indicate either debriefing approach as meaningfully improved over the other. CONCLUSIONS: Our study did not demonstrate that either TRD versus RCDP was meaningfully better in teamwork knowledge acquisition or improving skill application and performance. As such, we propose Reflective Deliberate Practice as a framework for future study to allow learners to reflect on learning and practice in action.

Meta-QTL analysis in wheat: progress, challenges and opportunities.

Wheat, an important cereal crop globally, faces major challenges due to increasing global population and changing climates. The production and productivity are challenged by several biotic and abiotic stresses. There is also a pressing demand to enhance grain yield and quality/nutrition to ensure global food and nutritional security. To address these multifaceted concerns, researchers have conducted numerous meta-QTL (MQTL) studies in wheat, resulting in the identification of candidate genes that govern these complex quantitative traits. MQTL analysis has successfully unraveled the complex genetic architecture of polygenic quantitative traits in wheat. Candidate genes associated with stress adaptation have been pinpointed for abiotic and biotic traits, facilitating targeted breeding efforts to enhance stress tolerance. Furthermore, high-confidence candidate genes (CGs) and flanking markers to MQTLs will help in marker-assisted breeding programs aimed at enhancing stress tolerance, yield, quality and nutrition. Functional analysis of these CGs can enhance our understanding of intricate trait-related genetics. The discovery of orthologous MQTLs shared between wheat and other crops sheds light on common evolutionary pathways governing these traits. Breeders can leverage the most promising MQTLs and CGs associated with multiple traits to develop superior next-generation wheat cultivars with improved trait performance. This review provides a comprehensive overview of MQTL analysis in wheat, highlighting progress, challenges, validation methods and future opportunities in wheat genetics and breeding, contributing to global food security and sustainable agriculture.

4-Chloro-3-nitrocoumarin as a precursor for synthesis of 2-arylchromeno[3,4-b]pyrrol-4(3H)-ones: a case of nitro group directed reductive coupling.

A series of 2-aryl substituted chromeno[3,4-b]pyrrol-4(3H)-ones were prepared in two steps by employing 4-chloro-3-nitrocoumarin as a precursor. The reaction involved the base-mediated reductive coupling of 4-chloro-3-nitrocoumarin with α-bromoacetophenone, followed by reductive intramolecular cyclization to afford the pyrrolocoumarin ring. When α-bromoacetophenone was replaced with α-cyanoacetophenone, (E)-4-(nitromethylene)-4H-chromen-2-amine was isolated as the major product. The molecular structures of the prepared compounds were characterized by X-ray crystallography and the mechanisms for their formation were proposed.

Effect of cryopreservation and capacitation on expression patterns of ATP synthesis associated genes in bubaline spermatozoa.

This study investigated the expression patterns of certain ATP synthesis associated genes (GAPDHS, PGK2, ENO4 and MDH2) in fresh and frozen-thawed bubaline spermatozoa vis-à-vis capacitation. Eight adult Murrah buffalo bulls, aged 5-7 years, were randomly selected from a bull farm and fresh semen was collected once a week for four weeks (n = 32) from the selected bulls. Simultaneously, frozen straws of the same bulls were collected (n = 32, four straws were pooled per sample). The samples were divided into four groups i.e., fresh non capacitated (control/group 1), fresh capacitated (group 2), frozen non capacitated (group 3) and frozen capacitated (group 4). In all groups mRNA extraction was done. The mRNA expression of GAPDHS was significantly higher in group 3 compared to the other groups, whereas the expression of ENO4 was significantly up-regulated in group 2 and 3 compared to the group 4. Similarly, the mRNA expression of PGK2 was significantly up-regulated in group 3 whereas in case of MDH2, it was significantly higher in group 2, 3 and 4 compared group 1. It can be concluded from our study that freezing and capacitation has a significant effect on the expression dynamics of the ATP synthesis-associated genes warranting necessary interventions in handling procedures to minimise the adverse effect of freezing on ATP synthesis process to ensure persistence of fertilizing ability of sperm.

Can adoption of climate resilient management practices achieve carbon neutrality in traditional green revolution states of Punjab and Haryana?

Decreasing greenhouse gas (GHG) emissions and enhancing soil carbon (C) sequestration in cropland are necessary to achieve carbon neutrality at national scale. The major objective of this study is to quantify the GHG mitigation potential of adopted climate resilient (CR) practices in CR villages using Ex-ACT tool developed by Food and Agriculture Organization (FAO). Intensively cultivated area of Punjab and Haryana was selected for carrying out this study. In both the states, villages were selected by considering the climate for past 30 years. In the selected villages, a set of CR practices were implemented in annuals, perennials, irrigated rice, fertilizer use, land use change and livestock and quantified the GHG mitigation potential in these villages for next twenty years. The tool predicted that the CR practices adopted were successful in enhancing the overall sink (carbon balance) in all the study villages. The villages of Punjab had recorded higher mitigation potential as compared to the villages of Haryana. The overall sink potential in these villages ranged from -354 to -38309 Mg CO2-eq. The change in sink potential varied from 3.16 to 112% with lowest in Radauri and highest in Badhauchhi kalan village. The sink potential got doubled in Badhauchhi kalan village due to stopping rice straw burning and increase in area under perennials by 25%. The source potential varied from 6.33 to -7.44% across the study villages. Even with the implementation of NICRA, there was increase in source by 5.58 and 6.33% in Killi Nihal Singh Wala and Radauri due to irrigated rice, land use change and livestock. Majorly, rice straw burning was seen in most of the study villages, yet, with proper residue management and adoption of CR practices (mainly intermittent flooding) in rice cultivation resulted in emissions reduction up to 5-26% with enhanced productivity up to 15-18%, which can be considered for scaling up. Fertilizer management reduced the emissions by average of 13% across the study villages. Farm gate emission intensity per ton of milk and rice recorded highest emission intensity compared to annuals and perennials suggesting strict implementation of CR practices in rice cultivation and livestock sector. Implementation and scaling up of CR practices could potentially reduce the emissions and make the village C negative in intensive rice-wheat production system.

Weight-Based Versus Flat Dosing of Epinephrine During Cardiac Arrest in the PICU: A Multicenter Survey.

OBJECTIVES: Pediatric Advanced Life Support (PALS) guidelines include weight-based epinephrine dosing recommendations of 0.01 mg/kg with a maximum of 1 mg, which corresponds to a weight of 100 kg. Actual practice patterns are unknown. DESIGN: Multicenter cross-sectional survey regarding institutional practices for the transition from weight-based to flat dosing of epinephrine during cardiopulmonary resuscitation in PICUs. Exploratory analyses compared epinephrine dosing practices with several institutional characteristics using Fisher exact test. SETTING: Internet-based survey. SUBJECTS: U.S. PICU representatives (one per institution) involved in resuscitation systems of care. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 137 institutions surveyed, 68 (50%) responded. Most responding institutions are freestanding children's hospitals or dedicated children's hospitals within combined adult/pediatric hospitals (67; 99%); 55 (81%) are academic and 41 (60%) have PICU fellowship programs. Among respondents, institutional roles include PICU medical director (13; 19%), resuscitation committee member (23; 34%), and attending physician with interest in resuscitation (21; 31%). When choosing between weight-based and flat dosing, 64 respondents (94%) report using patient weight, 23 (34%) patient age, and five (7%) patient pubertal stage. Among those reporting using weight, 28 (44%) switch at 50 to less than 60 kg, 17 (27%) at 60 to less than 80 kg, five (8%) at 80 to less than 100 kg, and eight (12%) at greater than or equal to 100 kg. Among those reporting using age, four (17%) switch at 14 to less than 16 years, five (22%) at 16 to less than 18, and six (26%) at greater than or equal to 18. Twenty-nine respondents (43%) report using ideal body weight when dosing epinephrine in obese patients. Using patient age in choosing epinephrine dosing is more common in institutions that require Advanced Cardiac Life Support (ACLS) certification for some/all code team responders compared with institutions that do not require ACLS certification (52% vs 22%; p = 0.02). CONCLUSIONS: The majority of PICUs surveyed report epinephrine dosing practices that are inconsistent with PALS guidelines.

Survey of Current Institutional Practices in the Use of High-Flow Nasal Cannula for Pediatric Patients.

OBJECTIVES: High-flow nasal cannula (HFNC) is an oxygen delivery device that provides heated humidified air with higher flow rates. The purpose of this survey is to look at institutional practice patterns of HFNC initiation, weaning, and disposition for pediatric patients across the United States. METHODS: Survey was sent via electronic listservs to pediatric physicians in emergency medicine, hospital medicine, critical care, and urgent care. The questionnaire was divided into demographics and HFNC practices (initiation, management, and weaning). One response per institution was included in the analysis. RESULTS: Two hundred twenty-four responses were included in the analysis, composed of 40% pediatric emergency medicine physicians, 46% pediatric hospitalists, 13% pediatric intensive care unit (PICU) physicians, and 1% pediatric urgent care physicians. Ninety-eight percent of the participants have HFNC at their institution. Thirty-seven percent of the respondents had a formal guideline for HFNC initiation. Nearly all guideline and nonguideline institutions report HFNC use in bronchiolitis. Guideline cohort is more likely to have exclusion criteria for HFNC (42% in the guideline cohort vs 17% in the nonguideline cohort; P < 0.001) and less frequently mandates PICU admissions once on HFNC (11% in the guideline cohort vs 56% in the nonguideline cohort; P < 0.001). Forty-six percent of guideline cohort had an objective scoring system to help determine the need for HFNC, and 73% had a weaning guideline. CONCLUSIONS: Although there is general agreement to use HFNC in bronchiolitis, great practice variation remains in the initiation, management, and weaning of HFNC across the United States. There is also a discordance on PICU use when a patient is using HFNC.

Whole-genome characterization and comparative genomics of a novel freshwater cyanobacteria species: Pseudanabaena punensis.

Cyanobacteria are emerging as a potential source of novel, beneficial bioactive compounds. However, some cyanobacteria species can harm water quality and public health through the production of toxins. Therefore, surveying the occurrence and generating genomic resources of cyanobacteria producing harmful compounds could help develop the control methods necessary to manage their growth and limit the release contaminants into the water bodies. Here, we describe a novel strain, Pseudanabaena punensis isolated from the open ends of pipelines supplying freshwater. This isolate was characterized morphologically, biochemically and by whole-genome sequence analysis. We also provide genomic information for P. punensis to help understand and highlight the features unique to this isolate. Morphological and genetic (analysis using 16S rRNA and rbcL genes) data were used to assign this novel strain to phylogenetic and taxonomic groups. The isolate was identified as a filamentous and non-heterocystous cyanobacteria. Based on morphological and 16S rRNA phylogeny, this isolate shares characteristics with the Pseudanabaenaceae family, but remains distinct from well-characterized species suggesting its polyphyletic assemblage. The whole-genome sequence analysis suggests greater genomic and phenotypic plasticity. Genome-wide sequence and comparative genomic analyses, comparing against several closely related species, revealed diverse and important genes associated with synthesizing bioactive compounds, multi-drug resistance pathway, heavy metal resistance, and virulence factors. This isolate also produces several important fatty acids with potential industrial applications. The observations described in this study emphasize both industrial applications and risks associated with the freshwater contamination, and therefore genomic resources provided in this study offer an opportunity for further investigations.

miRNA for the assessment of lymph node metastasis in patients with oral squamous cell carcinoma: Systematic review and metanalysis.

BACKGROUND: miRNA is one of the advanced epigenetic molecular markers correlating with lymph node metastasis in patients with Oral squamous cell carcinoma (OSCC). Numerous published papers are showing correlation of miRNA with metastasis. There is a need to analyze and validate such correlation. METHOD: English language literature in major databases from the last 20 years was searched using controlled vocabulary and keywords. Strict inclusion and exclusion criteria were followed for selection of studies. The quality assessment was done as per the QUADAS tool 2 by three independent reviewers. The metanalysis was performed by using random effect model. Standardized mean difference (SMD) was considered as the effect measure. Statistical software used was STATA version 13.1. RESULTS: With all inclusion and exclusion criteria, eight studies could qualify for metanalysis. The pooled estimate is found to be 0.13 (-0.35, 0.62), P = .585, which is statistically not significant. This indicates that there is a no significant difference in the fold change between metastasis and no metastasis groups. P-value of chi-square statistic for heterogeneity is <.001 (significant), and I-squared statistic is 87.2%, which indicates that heterogeneity is present to a considerable extent. Egger's test shows there is no publication bias involved (P = .819). CONCLUSION: The metanalysis showed no significant difference in the fold change of miRNA expression between metastasis and non-metastasis OSCC patients. Future studies can be directed to eliminate the heterogeneity among the studies noted in this analysis to confirm the role of miRNA for assessment of regional metastasis with special focus on tongue squamous cell carcinoma.

A Survey Assessing Pediatric Transport Team Composition and Training.

OBJECTIVE: The aim of this study was to assess national pediatric/neonatal specialty transport teams' composition and training requirements to determine if any current standardization exists. METHODS: This was a survey of the transport teams listed with the American Academy of Pediatrics via SurveyMonkey. RESULTS: While most of the teams maintain internal criteria for team competency and training, there is large variation across team compositions. The vast majority of the teams have a nurse-led team with the addition of another nurse, medic, and/or respiratory therapist regardless of mode of transport. Many of the teams report adjusting team composition based on acuity. Fewer than 15% of teams have a physician as a standard team member. More than 80% required a minimum number of supervised intubations prior to independent practice; however, the number varied largely from as little as 3 to as many as 30. Eighty-eight percent of the teams report using simulation as part of their education program, but again there were marked differences between teams as to how it was used. CONCLUSIONS: There is tremendous variability nationally among pediatric/neonatal transport teams regarding training requirements, certifications, and team composition. The lack of standardization regarding team member qualifications or maintenance of competency among specialized transport teams should be looked at more closely, and evidence-based guidelines may help lead to further improved outcomes in the care of critically ill pediatric patients in the prehospital setting.

Characterization of Myocardial Dysfunction in Fluid- and Catecholamine-Refractory Pediatric Septic Shock and Its Clinical Significance.

PURPOSE:: Myocardial dysfunction is a known complication in patients with pediatric septic shock (PSS); however, its clinical significance remains unclear. The purpose of this study was to characterize left ventricular (LV) and right ventricular (RV) dysfunction and their prevalence in patients with PSS using echocardiography (echo) and to investigate their associations with the severity of illness and clinical outcomes. METHODS:: Retrospective chart review between 2010 and 2015 from 2 tertiary care pediatric intensive care units. Study included 78 patients (mean age 9.3 ± 7 years) from birth up to 21 years who fulfilled criteria for fluid- and catecholamine-refractory septic shock. Echocardiographic parameters of systolic, diastolic, and global function were measured offline. They were correlated with admission Pediatric Risk of Mortality III (PRISM III) and Pediatric Logistic Organ Dysfunction scores, vasoactive-inotrope score (VIS), ß-type natriuretic peptide (BNP), lactate, type of shock, duration of mechanical ventilation (MV), intensive care unit and hospital length of stay, and mortality. RESULTS:: Overall, 28-day mortality was 26%, and 88% patients required MV. Prevalence of LV dysfunction was 72% and RV dysfunction was 63%. LV systolic dysfunction (fractional shortening z score <-2) was significantly associated with PRISM III, VIS, and BNP. RV systolic dysfunction (tricuspid annular plane systolic excursion z score <-2) was significantly associated with cold shock. LV and RV diastolic dysfunction did not have any significant clinical associations. No echocardiographic measures were associated with mortality. CONCLUSION:: Myocardial dysfunction is highly prevalent in PSS but is not associated with mortality. LV systolic dysfunction is associated with a higher severity of illness, use of vasoactives, and BNP, whereas RV systolic dysfunction is associated with cold shock. Further studies are needed to determine the utility of echo in the bedside management of patients with PSS.

Rapid Cycle Deliberate Practice Versus Reflective Debriefing for Pediatric Septic Shock Training.

OBJECTIVES: Rapid cycle deliberate practice is a simulation training method that cycles between deliberate practice and directed feedback to create perfect practice; in contrast to reflective debriefing where learners are asked to reflect on their performance to create change. The aim of this study is to compare the impact of rapid cycle deliberate practice versus reflective debriefing training on resident application and retention of the pediatric sepsis algorithm. DESIGN: Prospective, randomized-control study. SETTING: A tertiary care university children's hospital simulation room, featuring a high-fidelity pediatric patient simulator. SUBJECTS: Forty-six upper-level pediatric residents. INTERVENTIONS: Simulation training using rapid cycle deliberate practice or reflective debriefing. MEASUREMENTS AND MAIN RESULTS: Knowledge was assessed with a quiz on core sepsis management topics. The application of knowledge was assessed with a sepsis management checklist during the simulated scenario. The residents were assessed before and after the intervention and again at a follow-up session, 3-4 months later, to evaluate retention. Both groups had similar pre-intervention scores. Post-intervention, the rapid cycle deliberate practice group had higher checklist scores (rapid cycle deliberate practice 18 points [interquartile range, 18-19] vs reflective debriefing 17 points [interquartile range, 15-18]; p < 0.001). Both groups had improved quiz scores. At follow-up, both groups continued to have higher scores compared with the pre-intervention evaluation, with the rapid cycle deliberate practice group having a greater change in checklist score from pre-intervention to follow-up (rapid cycle deliberate practice 5 points [interquartile range, 3.5-7] vs reflective debriefing 3 points [interquartile range, 1.5-4.5]; p = 0.019). Both groups reported improved confidence in diagnosing and managing septic shock. CONCLUSIONS: Both rapid cycle deliberate practice and reflective debriefing are effective in training pediatric residents to apply the sepsis algorithm and in improving their confidence in the management of septic shock. The rapid cycle deliberate practice method was superior immediately post-training; however, it is unclear if this advantage is maintained over time. Both methods should be considered for training residents.

Gold Nanoparticles as Boron Carriers for Boron Neutron Capture Therapy: Synthesis, Radiolabelling and In vivo Evaluation.

Background: Boron Neutron Capture Therapy (BNCT) is a binary approach to cancer therapy that requires accumulation of boron atoms preferentially in tumour cells. This can be achieved by using nanoparticles as boron carriers and taking advantage of the enhanced permeability and retention (EPR) effect. Here, we present the preparation and characterization of size and shape-tuned gold NPs (AuNPs) stabilised with polyethylene glycol (PEG) and functionalized with the boron-rich anion cobalt bis(dicarbollide), commonly known as COSAN. The resulting NPs were radiolabelled with 124I both at the core and the shell, and were evaluated in vivo in a mouse model of human fibrosarcoma (HT1080 cells) using positron emission tomography (PET). Methods: The thiolated COSAN derivatives for subsequent attachment to the gold surface were synthesized by reaction of COSAN with tetrahydropyran (THP) followed by ring opening using potassium thioacetate (KSAc). Iodination on one of the boron atoms of the cluster was also carried out to enable subsequent radiolabelling of the boron cage. AuNPs grafted with mPEG-SH (5 Kda) and thiolated COSAN were prepared by ligand displacement. Radiolabelling was carried out both at the shell (isotopic exchange) and at the core (anionic absorption) of the NPs using 124I to enable PET imaging. Results: Stable gold nanoparticles simultaneously functionalised with PEG and COSAN (PEG-AuNPs@[4]-) with hydrodynamic diameter of 37.8 ± 0.5 nm, core diameter of 19.2 ± 1.4 nm and ξ-potential of -18.0 ± 0.7 mV were obtained. The presence of the COSAN on the surface of the NPs was confirmed by Raman Spectroscopy and UV-Vis spectrophotometry. PEG-AuNPs@[4]- could be efficiently labelled with 124I both at the core and the shell. Biodistribution studies in a xenograft mouse model of human fibrosarcoma showed major accumulation in liver, lungs and spleen, and poor accumulation in the tumour. The dual labelling approach confirmed the in vivo stability of the PEG-AuNPs@[4]-. Conclusions: PEG stabilized, COSAN-functionalised AuNPs could be synthesized, radiolabelled and evaluated in vivo using PET. The low tumour accumulation in the animal model assayed points to the need of tuning the size and geometry of the gold core for future studies.

Exposure of Staphylococcus aureus to Targocil Blocks Translocation of the Major Autolysin Atl across the Membrane, Resulting in a Significant Decrease in Autolysis.

Peptidoglycan (PG) and wall teichoic acid (WTA) are the major staphylococcal cell wall components, and WTA biosynthesis has recently been explored for drug development. Targocil is a novel agent that targets the TarG subunit of the WTA translocase (TarGH) that transports WTA across the membrane to the wall. Previously we showed that targocil treatment of a methicillin-susceptible Staphylococcus aureus strain led to a rapid shut down of cellular autolysis. Targocil II, which targets the TarH subunit of TarGH, also resulted in a drastic decrease in autolysis. Here, we address the mechanism of targocil-mediated decreased autolysis. The mechanism is WTA dependent since targocil treatment decreased autolysis in methicillin-resistant strains but not in a WTA-deficient mutant. Similar to cellular autolysis, autolysin-retaining crude cell walls isolated from targocil-treated cells had vastly decreased autolytic activity compared to those from untreated cells. Purified cell walls from control and targocil-treated cells, which lack autolytic activity, were similarly susceptible to lysozyme and lysostaphin and had similar O-acetyl contents, indicating that targocil treatment did not grossly alter PG structure and chemistry. Purified cell walls from targocil-treated cells were highly susceptible to autolysin extracts, supporting the notion that targocil treatment led to decreased autolysin in the crude cell walls. Quantitative real-time PCR analysis revealed that the decrease in autolysis in the targocil-exposed cells was not due to transcriptional repression of the autolysin genes atl, lytM, lytN, and sle1 Zymographic analysis of peptidoglycan hydrolase profiles showed a deficiency of cell surface autolysins in targocil-treated cells but higher activity in cell membrane fractions. Here, we propose that the untranslocated WTA molecules in the targocil-exposed cells sequester Atl at the membrane, resulting in significantly decreased autolysis.

An Intraoperative Visualization System Using Hyperspectral Imaging to Aid in Brain Tumor Delineation.

Hyperspectral imaging (HSI) allows for the acquisition of large numbers of spectral bands throughout the electromagnetic spectrum (within and beyond the visual range) with respect to the surface of scenes captured by sensors. Using this information and a set of complex classification algorithms, it is possible to determine which material or substance is located in each pixel. The work presented in this paper aims to exploit the characteristics of HSI to develop a demonstrator capable of delineating tumor tissue from brain tissue during neurosurgical operations. Improved delineation of tumor boundaries is expected to improve the results of surgery. The developed demonstrator is composed of two hyperspectral cameras covering a spectral range of 400-1700 nm. Furthermore, a hardware accelerator connected to a control unit is used to speed up the hyperspectral brain cancer detection algorithm to achieve processing during the time of surgery. A labeled dataset comprised of more than 300,000 spectral signatures is used as the training dataset for the supervised stage of the classification algorithm. In this preliminary study, thematic maps obtained from a validation database of seven hyperspectral images of in vivo brain tissue captured and processed during neurosurgical operations demonstrate that the system is able to discriminate between normal and tumor tissue in the brain. The results can be provided during the surgical procedure (~1 min), making it a practical system for neurosurgeons to use in the near future to improve excision and potentially improve patient outcomes.

Interrelationships between Fatty Acid Composition, Staphyloxanthin Content, Fluidity, and Carbon Flow in the Staphylococcus aureus Membrane.

Fatty acids play a major role in determining membrane biophysical properties. Staphylococcus aureus produces branched-chain fatty acids (BCFAs) and straight-chain saturated fatty acids (SCSFAs), and can directly incorporate exogenous SCSFAs and straight-chain unsaturated fatty acids (SCUFAs). Many S. aureus strains produce the triterpenoid pigment staphyloxanthin, and the balance of BCFAs, SCSFAs and staphyloxanthin determines membrane fluidity. Here, we investigated the relationship of fatty acid and carotenoid production in S. aureus using a pigmented strain (Pig1), its carotenoid-deficient mutant (Pig1ΔcrtM) and the naturally non-pigmented Staphylococcus argenteus that lacks carotenoid biosynthesis genes and is closely related to S. aureus. Fatty acid compositions in all strains were similar under a given culture condition indicating that staphyloxanthin does not influence fatty acid composition. Strain Pig1 had decreased membrane fluidity as measured by fluorescence anisotropy compared to the other strains under all conditions indicating that staphyloxanthin helps maintain membrane rigidity. We could find no evidence for correlation of expression of crtM and fatty acid biosynthesis genes. Supplementation of medium with glucose increased SCSFA production and decreased BCFA and staphyloxanthin production, whereas acetate-supplementation also decreased BCFAs but increased staphyloxanthin production. We believe that staphyloxanthin levels are influenced more through metabolic regulation than responding to fatty acids incorporated into the membrane.

Resuscitation With Balanced Fluids Is Associated With Improved Survival in Pediatric Severe Sepsis.

OBJECTIVE: To evaluate outcomes in patients receiving balanced fluids for resuscitation in pediatric severe sepsis. DESIGN: Observational cohort review of prospectively collected data from a large administrative database. SETTING: PICUs from 43 children's hospitals. PATIENTS: PICU patients diagnosed with severe sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We reviewed data from the Pediatric Health Information System database from 2004 to 2012. Children with pediatric severe sepsis receiving balanced fluids for resuscitation in the first 24 and 72 hours of treatment were compared to those receiving unbalanced fluids. Thirty-six thousand nine hundred eight patients met entry criteria for analysis. Two thousand three hundred ninety-eight patients received exclusively balanced fluids at 24 hours and 1,641 at 72 hours. After propensity matching, the 72-hour balanced fluids group had lower mortality (12.5% vs 15.9%; p = 0.007; odds ratio, 0.76; 95% CI, 0.62-0.93), lower prevalence of acute kidney injury (16.0% vs 19.2%; p = 0.028; odds ratio, 0.82; 95% CI, 0.68-0.98), and fewer vasoactive infusion days (3.0 vs 3.3 d; p < 0.001) when compared with the unbalanced fluids group. CONCLUSIONS: In this retrospective analysis carried out by propensity matching, exclusive use of balanced fluids in pediatric severe sepsis patients for the first 72 hours of resuscitation was associated with improved survival, decreased prevalence of acute kidney injury, and shorter duration of vasoactive infusions when compared with exclusive use of unbalanced fluids.