Prognostic Value of Lymph Node-to-Primary Tumor Ratio of PET Standardized Uptake Value for Nasopharyngeal Carcinoma: A Recursive Partitioning Risk Stratification Analysis

PURPOSE/OBJECTIVE(S)

To evaluate the prognostic value of the lymph node-to-primary tumor ratio (NTR) of positron emission tomography (PET) standardized uptake value (SUV) for nasopharyngeal carcinoma (NPC) patients treated with induction chemotherapy (IC).

MATERIALS/METHODS

Four hundred and sixty-seven locoregionally advanced NPC patients with pretreatment 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) scans between September 2017 and November 2020 were retrospectively reviewed. All patients underwent IC plus intensity-modulated radiotherapy (IMRT). The receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off value of SUV NTR. Kaplan-Meier method was used to evaluate survival rates. The recursive partitioning analysis (RPA) was performed to construct a risk stratification model.

RESULTS

The optimal cut-off value of SUV NTR was 0.74. Multivariate analyses showed that SUV NTR and overall stage were independent predictors for distant metastasis-free survival (DMFS) and regional recurrent-free survival (RRFS). Therefore, an RPA model based on the endpoint of DMFS was generated and categorized the patients into three distinct risk groups: RPA I (low-risk: SUV NTR<7.4 and stage III), RPA II (medium-risk: SUV NTR<7.4 and stage IVa, or SUV NTR≥7.4 and stage III), and RPA III (high-risk: SUV NTR≥7.4 and stage IVa), with a 3-year DMFS of 98.9%, 93.4%, and 84.2%, respectively. ROC analysis showed that the RPA model had superior predictive efficacy than the SUV NTR or overall stage alone.

CONCLUSION

SUV NTR was an independent prognosticator for distant metastasis and regional recurrence in locoregionally advanced NPC. The RPA risk stratification model base on SUV NTR provides improved DMFS and RRFS prediction over the 8th edition of the TNM staging system.

Metagenomic reconstructions of caecal microbiome in Landes, Roman and Zhedong White geese

1. The caecal microbiota in geese play a crucial role in determining the host's health, disease status and behaviour, as evidenced by extensive epidemiological data. The present investigation conducted 10× metagenomic sequencing of caecal content samples obtained from three distinct goose species, namely Landes geese, Roman geese and Zhedong White geese (n = 5), to explore the contribution of the gut microbiome to carbohydrate metabolism.2. In total, 337GB of Illumina data were generated, which identified 1,048,575 complete genes and construction of 331 metagenomic bins, encompassing 78 species from nine phyla. Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Bacteria were identified as the dominant phyla while Prevotella, Bacteroides, Streptococcus, and Subdoligranulum were the most abundant genera in the caecum of geese.3. The genes were allocated to 375 pathways using the Kyoto Encyclopedia of Genes and Genome (KEGG) analysis. The most abundant classes in the caecum of geese were confirmed to be glycoside hydrolases (GHs), glycosyl transferases (GTs), as identified through the carbohydrate-active enzyme (CAZyme) database mapping. Subdoligranulum variabile and Mediterraneibacter glycyrrhizinilyticus were discovered to potentially facilitate carbohydrate digestion in geese.4. Notwithstanding, further investigation and validation are required to establish a connection between these species and CAZymes. Based on binning analysis, Mediterraneibacter glycyrrhizinilyticus and Ruminococcus sp. CAG:177 are potential species in LD geese that contribute to the production of fatty liver.

Predictive value of total ischaemic time and T1 mapping after emergency percutaneous coronary intervention in acute ST-segment elevation myocardial infarction

AIM

To investigate the predictive value of ischaemic time and cardiac magnetic resonance imaging (CMRI) T1 mapping in acute ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

A total of 127 patients with STEMI treated by primary PCI were studied. All patients underwent CMRI with native T1 and extracellular volume (ECV) measurement, 61 of whom also had 4-month follow-up data. The total ischaemic (symptom onset to balloon, S2B) time expressed in minutes was recorded. CMRI cine, T1 mapping, and late gadolinium enhancement (LGE) images were analysed to evaluate left ventricular (LV) function, T1 value, ECV, and myocardial infract (MI) scar characteristics, respectively. The correlation between S2B time and T1 mapping was evaluated. The predictive values of S2B time and T1 mapping for large final infarct size were estimated.

RESULTS

The incidence of microvascular obstruction (MVO) increased with the prolongation of ischaemia time. Regardless of MVO or not, ECV in myocardial infarction (ECVMI) was significantly correlated with S2B time (r=0.61, p<0.001), while native T1 in MI (T1MI) was not (r=-0.19, p=0.029). In the 4-month follow-up, native T1MI was improved (1385.1 ± 90.4 versus 1288.6 ± 74 ms, p<0.001). Furthermore, ECVMI was independently associated with final larger infarct size (AUC = 0.89, 95% confidence interval [CI] = 0.81-0.98, p<0.001) in multivariable regression analysis.

CONCLUSION

ECVMI was correlated with total ischaemic time and was an independent predictor of final larger infarct size.

Patterns of Failure in Pediatric and Young Adult Rhabdomyosarcoma

PURPOSE/OBJECTIVE(S)

To characterize patterns of failure in pediatric and young adult patients with rhabdomyosarcoma (RMS) from a single institution with over 20 years of experience.

MATERIALS/METHODS

Patients diagnosed with RMS from 2000 to 2022 were identified retrospectively. Time to failure was calculated from diagnosis. Local only failure was defined as first failure at the primary site without distant failure. Distant failure was defined as first failure outside of the primary site with or without local failure. Cumulative incidence (CI) of failure was calculated using death as a competing risk. Fine-Gray regression was used to evaluate impact of prognostic factors.

RESULTS

Ninety-five patients were eligible. Median age was 7.28 years (range 0 - 35 years), 41% of patients were >10 years old. Median follow up was 33.3 months. Approximately half (n = 47, 49.5%) of the tumors demonstrated alveolar histology. FOXO1 fusion status was available in 76 (80%) patients, of which 7 out of 37 alveolar tumors (18.9%) were FOXO1 fusion negative. The majority of tumors presented with unfavorable primary site (n = 72, 75.8%) and advanced stage (Stage III and IV, n = 72, 75.8%). The 5-yr CI of local only failure and distant failure for the entire cohort was 19.0% (95% CI 11.3, 28.3) and 34.6% (24.0, 45.5%), respectively. The predominant pattern of failure by Group was: Groups 1&2: Local only (5yr CI 14.8%), Group 3: Distant (5yr CI: 25.9%), Group 4: Distant (5yr CI: 67.6%). CI of distant failure by primary site was higher in perianal/gluteal (n = 2/5, 5yr CI 60.0%) and extremity (n = 8/19, 5yr CI 45.9%) sites. Of the 28 distant failures, 10 (36%) also had a local failure component. CI of local only failure by primary site was higher in parameningeal head and neck (n = 6/25, 5yr CI 30%) and bladder/prostate (n = 2/12, 5yr CI 23%) sites. The following were associated with an increased CI of distant failures: increasing age (HR 1.08, p<0.01), alveolar vs. embryonal histology (HR 3.01, p = 0.0095), FOXO1 fusion positive vs. negative (HR 2.8, p = 0.02) and Group IV vs. Groups I/II (HR 7.7, p = 0.0007). FOXO1 fusion and alveolar histology were associated with older age and Group IV, both of which were independently associated with increased distant failure on multivariate analysis.

CONCLUSION

Failures were predominantly distant in older patients and patients with Group IV RMS, both of which were associated with FOXO1 fusion and alveolar histology, highlighting the need to improve therapies in this population. Local only failures were highest in parameningeal head and neck and bladder/prostate primaries, highlighting the need to improve local control strategies at these sites.

Progression-Free Survival as a Surrogate Endpoint of Overall Survival in Patients with Locally Advanced Non-Small Cell Lung Cancer Treated with Chemoradiotherapy: Trial-Level Meta-Analysis and Individual-Level Analysis of NRG/RTOG 0617 and PROCLAIM

PURPOSE/OBJECTIVE(S)

Overall Survival (OS) is the gold standard endpoint in randomized clinical trials (RCTs) of Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC). Intermediate endpoints that can be observed at earlier time points and predict OS would improve trial efficiency and expedite the adoption of proven interventions.

MATERIALS/METHODS

Atrial-level meta-analysis was conducted using a weighted regression analysis to quantify the correlation between PFS and OS hazard ratios (HRs). Large (n≥ 100) contemporary RCTs in LA-NSCLC that used platinum-based chemoradiation were included. An individual-level surrogacy analysis based on Prentice criteria was performed to evaluate if PFS could reliably predict OS using NRG/RTOG 0617 (NCT00533949), a phase III RCT of dose escalated CRT. The individual-level correlation between PFS and OS was validated using PROCLAIM (NCT00686959) control arm.

RESULTS

Nineteen RCTs comprising a total of 5525 patients (pts) were included in the trial-level meta-analysis. A moderately high correlation was observed between PFS HR and OS HR (R2 = 0.68, 95% CI = 0.42-0.94). Individual-level analysis of NRG/RTOG 0617 showed that, as reported, RT dose was associated with OS (HR = 1.28, 95% CI = 1.04-1.58, p = 0.02) and PFS (HR = 1.21, 95% CI = 0.99-1.46, p = 0.06). Progressive disease (PD) was highly associated with OS, where pts having PD within 6mo or 12mo had a significantly higher mortality risk than those not having PD within 6mo or 12 mo, respectively, in landmark analysis (PD within 6mo: HR = 2.56, 95% CI = 1.82-3.59, p<0.0001; PD within 12mo: HR = 3.18, 95% CI = 2.45-4.12, p<0.0001). Accounting for PD moderately reduced RT dose effect on OS (HR = 1.21, 95% CI = 0.98-1.49), suggesting RT dose effect on OS may be mediated partially through PD. The association between OS and PD occurrence within 6mo or 12mo was similar in PROCLAIM control arm (PD within 6mo: HR = 2.06, 95% CI = 1.48-2.86, p<0.0001; PD within 12mo: HR = 2.02, 95% CI = 1.38-2.95, p<0.0001).

CONCLUSION

A moderately high trial-level surrogacy between PFS and OS was identified in trial-level meta-analysis. PD occurrence also reliably predicted OS at the individual patient level in both NRG/RTOG 0617 and PROCLAIM. These results support the use of PFS as a valid endpoint in clinical trials of LA-NSCLC.

Radiotherapy Alone vs. Concurrent or Adjuvant Chemoradiotherapy for Nasopharyngeal Carcinoma Patients with Negative Epstein-Barr Virus DNA Post-Induction Chemotherapy

PURPOSE/OBJECTIVE(S)

Induction chemotherapy (IC) plus concurrent chemoradiotherapy has been recommended as the standard treatment for locoregionally advanced nasopharyngeal carcinoma (LA-NPC). However, concurrent chemotherapy was associated with increased toxicities, poor tolerance, and low completion rates. The aim of this study was to compare the efficacy and toxicity of IC+ radiotherapy (RT) and IC+ concurrent or adjuvant chemoradiotherapy (IC+CCRT/AC) in patients with negative post-IC EBV DNA.

MATERIALS/METHODS

A total of 547 NPC patients with negative plasma EBV DNA post-IC were included. Patients were classified into the IC+RT group and the IC+ concurrent or adjuvant chemoradiotherapy (IC+CCRT/AC) group. Locoregional relapse-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS), and progression-free survival (PFS) were estimated and compared using the Kaplan-Meier method. Propensity-score matching (PSM) was performed to balance the variables.

RESULTS

The median follow-up time was 37 months. The 3-year LRFS, DMFS, OS, and PFS rates for the whole group were 92.2%, 92.4%, 96.4%, and 84.4%, respectively. There was no significant difference in LRFS, DMFS, OS, and PFS between the IC+RT and the IC+CCRT/AC group both before PSM (3-year rates of 91.1% vs. 92.6%, p = 0.94; 95.6% vs. 91.5%, p = 0.08; 95.2% vs. 96.8%, p = 0.80; 85.9% vs. 84.0%, p = 0.38) and after PSM (90.7% vs. 92.7%, p = 0.77; 96.8% vs. 93.7%, p = 0.29; 94.5% vs. 93.9%, p = 0.57; 84.7% vs. 85.6%, p = 0.96). Multivariate analysis demonstrated that treatment schedule was not an independent predictor for survival rates. Patients in the IC+RT group had fewer treatment-related acute toxicities and better tolerance.

CONCLUSION

IC+RT displayed similar survival outcomes as IC+CCRT/AC for NPC patients with negative post-IC EBV DNA. Our current data seems not to support the routine use of concurrent or adjuvant chemotherapy after IC for unselected patients.

Association of Overall Survival Benefit Profile of Radiotherapy with Progression-Free Survival after Chemotherapy for Diffuse Large B-Cell Lymphoma

PURPOSE/OBJECTIVE(S)

Benefit of radiotherapy (RT) after chemotherapy (CT) of diffuse large B-cell lymphoma (DLBCL) remains controversial. It is unknown whether improved progression-free survival (PFS) by RT translate into an overall survival (OS) benefit. To address this question, our research comprehensively evaluated the risk-benefit assessment of RT in DLBCL through an in-depth examination of previously reported data from randomized controlled trials (RCTs) and retrospective comparative studies.

MATERIALS/METHODS

After screening and quality control, this study included 7 randomized controlled trials and 52 retrospective studies of combined-modality therapy (CMT) versus CT alone. The correlation between PFS and OS was evaluated using the Pearson linear correlation coefficient at trial- and study arm-level. A risk-benefit assessment to describe the OS benefit of RT was performed in meta-analyses of pooled HROS with PFS patterns.

RESULTS

In RCTs, strong correlations were found between HRPFS and HROS at trial-level (r = 0.876), and PFS and OS at treatment arm-level, regardless of treatments (r = 0.945-0.964 for all, CMT or CT). In retrospective studies, similar correlations between HRPFS and HROS (r = 0.639-0.650), and PFS and OS rates (r = 0.882-0.910) were observed, independent of treatments or rituximab. Adding RT into rituximab-based CT increased the average PFS rate from 63.6 ± 18.9% to 81.5 ± 10.6% (P<0.001), with differential OS benefits of RT between studies. Patients can be stratified into four PFS patterns (>80%, >60-80%, >40-60%, and ≤40%); absolute gain in OS from RT ranged from ≤5% at PFS >80% to ∼21% at PFS ≤40%, with pooled-HROS from 0.70 (95% CI, 0.51-0.97) to 0.48 (95% CI, 0.36-0.63) after rituximab-based CT. Linear analysis revealed an OS advantage of CMT over CT alone in a PFS-dependent manner.

CONCLUSION

We demonstrate a varied OS benefit profile of RT upon different PFS patterns, and provide valuable evidence for making treatment decisions and designing clinical trials. Future strategies to select the use of RT will need careful tailoring in clinical practice or within RCT to optimize outcome.

Inulin has a beneficial effect by modulating the intestinal microbiome in a BALB/c mouse model

Food allergy is an important health problem that affects human quality of life and socioeconomic development, and its treatment requires improvement. Intestinal flora dysbiosis is closely associated with food allergies. A sensitised mouse model was established by the intraperitoneal injection of ovalbumin (OVA). The mice were randomly divided into four groups: control, model, high-dose (H), and low-dose (L) inulin. The mice were administered water containing different concentrations of inulin four weeks before the OVA injection. Body weight changes were monitored. After the last OVA injection, the mice were scored for allergic reactions. The levels of total immunoglobulin E (IgE) and diamine oxidase (DAO) in the serum and secretory IgA (sIgA) in the small intestinal mucus were measured, and 16S rRNA sequencing of the faecal flora was performed to evaluate microbial parameters. The intestinal flora biomarkers, correlations between them, and biochemical indicators were analysed. Inulin treatment had no effect on the body weight of OVA-sensitised mice but attenuated allergic reactions and intestinal injury in mice. Compared with the control group, the model group had significantly higher levels of serum DAO and IgE and significantly lower levels of intestinal mucus IgA. IgA levels in the intestinal mucus of mice treated with inulin prior to OVA sensitisation were higher than those in non-inulin-treated OVA-sensitised mice. Furthermore, analysis of operational taxonomic units showed that inulin treatment decreased the abundance of Alloprevotella, Rikenellaceae RC9, Eubacterium siraeum, and Eubacterium xylanophilum, and increased the abundance of Blautia and Lachnospiraceae. Serum DAO levels were positively associated with Eubacterium siraeum, Alloprevotella, Eubacterium xylanophilum, and Odoribacter and negatively associated with Blautia, Tyzzerella, Alistipes, Desulfovibrionaceae, and Ruminococcaceae UCG005. In addition, IgE levels were positively associated with Eubacterium siraeum, Alloprevotella, Eubacterium xylanophilum, Odoribacter, and Citrobacter and negatively associated with Blautia, unclassified Ruminococcaceae, and Alistipes. IgA exhibited significant positive correlation with Blautia, norank_f_Eubacterium coprostanoligenes, Alistipes, norank Desulfovibrionaceae, Muribaculum, and Ruminococcaceae U C G 005 and significant negative correlation with Eubacterim siraeum, Eubacterium xylanophilum, Odoribacter, and Citrobacter. Inulin exerts a protective effect against food allergies in mice, which is partially mediated by alterations in the gut microbiota.

Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central ^{3}He+Au, d+Au and p+Au Collisions at sqrt[s_{NN}]=200 GeV

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200  GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

Observation of Directed Flow of Hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in sqrt[s_{NN}]=3 GeV Au+Au Collisions at RHIC

We report here the first observation of directed flow (v_{1}) of the hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in mid-central Au+Au collisions at sqrt[s_{NN}]=3  GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×10^{6} events in 5%-40% centrality, about 8400 _{Λ}^{3}H and 5200 _{Λ}^{4}H candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v_{1} slopes of _{Λ}^{3}H and _{Λ}^{4}H follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au+Au collisions.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}^{2}) in Au+Au Collisions at RHIC

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200  GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Pharmacokinetics and safety of Padsevonil in healthy Chinese subjects and comparison of two sampling methods for Padsevonil quantification

OBJECTIVE

Padsevonil (PSL) is a novel antiepileptic drug candidate that inhibits seizure activity in both presynaptic and postsynaptic ways. The pharmacokinetic (PK) profiles and volumetric absorptive microsampling (VAMS) application of PSL in the Chinese population are limited. The objectives of this study were to evaluate the PK profile of PSL and its 2 metabolites, the safety of PSL, and compare the PK profile of PSL from samples collected using the VAMS technique with that of conventional venous samples in healthy Chinese subjects.

SUBJECTS AND METHODS

In this randomized, double-blind, placebo-controlled single-dose study, the participants received either 200 mg PSL or placebo. Blood samples for the PK variables were collected using both the traditional venous method and the VAMS Mitra® technique at the scheduled time points. The PK parameters of PSL and 2 metabolites were calculated, and the concentration agreement of VAMS and venous samples were also evaluated.

RESULTS

A total of 14 subjects were enrolled. The concentration-time profile of PSL showed rapid absorption with a median tmax of 1.25 h (range: 0.5 to 3.0), followed by an apparent biphasic disposition. For PSL, the geometric means of AUC(0-t), AUC, Cmax, and t1/2 were 6,573 h*ng/mL, 6,588 h*ng/mL, 1,387 ng/mL, and 5.275 h, respectively. The geometric mean body weight-normalized AUC(0-t), AUC, and Cmax were 5,712 h*ng/mL, 5,725 h*ng/mL, and 1,205 ng/mL, respectively. The AUC(0-t), AUC, Cmax of PSL and metabolites in VAMS-dried blood were all lower than those in plasma. The Passing-Bablok regression showed that the PSL and metabolite concentrations obtained by VAMS analysis were comparable to those obtained by plasma at some time points. The most frequently reported treatment-emergent adverse events (TEAEs) were somnolence and dizziness. There were no serious TEAEs, severe TEAEs, discontinuations due to TEAEs, or deaths reported during this study. No clinically significant laboratory, vital signs, electrocardiograph (ECG), or physical examination results were reported.

CONCLUSIONS

PSL has a favorable PK profile after single-dose oral administration and good safety properties in healthy Chinese volunteers. The regression analysis results of VAMS and plasma indicated that the application of VAMS for therapeutic drug monitoring in novel antiepileptic drug development is promising and needs further validation.

Serial electroconvulsive Seizure alters dendritic complexity and promotes cellular proliferation in the mouse dentate gyrus; a role for Egr3

BACKGROUND

Despite being one of the safest, most effective treatments for severe mood disorders, the therapeutic mechanisms of electroconvulsive therapy remain unknown. Electroconvulsive seizure (ECS) induces rapid, high-level expression of immediate early genes (IEGs) and brain-derived neurotrophic factor (BDNF), in addition to stimulation of neurogenesis and dendritic remodeling of dentate gyrus (DG) neurons. We have previously shown that this upregulation of BDNF fails to occur in the hippocampus of mice lacking the IEG Egr3. Since BDNF influences neurogenesis and dendritic remodeling, we hypothesized that Egr3-/- mice will exhibit deficits in neurogenesis and dendritic remodeling in response to ECS.

OBJECTIVE

To test this hypothesis, we examined dendritic remodeling and cellular proliferation in the DG of Egr3-/- and wild-type mice following repeated ECS.

METHODS

Mice received 10 daily ECSs. Dendritic morphology was examined in Golgi-Cox-stained tissue and cellular proliferation was analyzed through bromodeoxyuridine (BrdU) immunohistochemistry and confocal imaging.

RESULTS

Serial ECS in mice results in dendritic remodeling, increased spine density, and cellular proliferation in the DG. Loss of Egr3 alters the dendritic remodeling induced by serial ECS but does not change the number of dendritic spines or cellular proliferation consequences of ECS.

CONCLUSION

Egr3 influences the dendritic remodeling induced by ECS but is not required for ECS-induced proliferation of hippocampal DG cells.

Measurement of Sequential ϒ Suppression in Au+Au Collisions at sqrt[s_{NN}]=200 GeV with the STAR Experiment

We report on measurements of sequential ϒ suppression in Au+Au collisions at sqrt[s_{NN}]=200  GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0%-60% centrality class, the nuclear modification factors (R_{AA}), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for ϒ(1S) and ϒ(2S) are 0.40±0.03(stat)±0.03(sys)±0.09(norm) and 0.26±0.08(stat)±0.02(sys)±0.06(norm), respectively, while the upper limit of the ϒ(3S) R_{AA} is 0.17 at a 95% confidence level. This provides experimental evidence that the ϒ(3S) is significantly more suppressed than the ϒ(1S) at RHIC. The level of suppression for ϒ(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited ϒ states.

Beam Energy Dependence of Fifth- and Sixth-Order Net-Proton Number Fluctuations in Au+Au Collisions at RHIC

We report the beam energy and collision centrality dependence of fifth and sixth order cumulants (C_{5}, C_{6}) and factorial cumulants (κ_{5}, κ_{6}) of net-proton and proton number distributions, from center-of-mass energy (sqrt[s_{NN}]) 3 GeV to 200 GeV Au+Au collisions at RHIC. Cumulant ratios of net-proton (taken as proxy for net-baryon) distributions generally follow the hierarchy expected from QCD thermodynamics, except for the case of collisions at 3 GeV. The measured values of C_{6}/C_{2} for 0%-40% centrality collisions show progressively negative trend with decreasing energy, while it is positive for the lowest energy studied. These observed negative signs are consistent with QCD calculations (for baryon chemical potential, μ_{B}≤110  MeV) which contains the crossover transition range. In addition, for energies above 7.7 GeV, the measured proton κ_{n}, within uncertainties, does not support the two-component (Poisson+binomial) shape of proton number distributions that would be expected from a first-order phase transition. Taken in combination, the hyperorder proton number fluctuations suggest that the structure of QCD matter at high baryon density, μ_{B}∼750  MeV at sqrt[s_{NN}]=3  GeV is starkly different from those at vanishing μ_{B}∼24  MeV at sqrt[s_{NN}]=200  GeV and higher collision energies.

[Levofloxacin combined with cellulase can eradicate bacille Calmette-Guerin biofilm infection]

OBJECTIVE

To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro.

METHODS

The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy.

RESULTS

The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 μg/mL, 8 μg/mL and 1024 μg/mL, respectively. The combined treatment with 1/4×MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001).

CONCLUSION

LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.