Personal endotoxin exposure in a panel study of school children with asthma

<p>Abstract</p> <p>Background</p> <p>Endotoxin exposure has been associated with asthma exacerbations and increased asthma prevalence. However, there is little data regarding personal exposure to endotoxin in children at risk, or the relation of personal endotoxin exposure to residential or ambient airborne endotoxin. The relation between personal endotoxin and personal air pollution exposures is also unknown.</p> <p>Methods</p> <p>We characterized personal endotoxin exposures in 45 school children with asthma ages 9-18 years using 376 repeated measurements from a PM_2.5active personal exposure monitor. We also assayed endotoxin in PM_2.5samples collected from ambient regional sites (N = 97 days) and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively) in Riverside and Whittier, California. Endotoxin was measured using the Limulus Amoebocyte Lysate kinetic chromogenic assay. At the same time, we measured personal, home and ambient exposure to PM_2.5mass, elemental carbon (EC), and organic carbon (OC). To assess exposure relations we used both rank correlations and mixed linear regression models, adjusted for personal temperature and relative humidity.</p> <p>Results</p> <p>We found small positive correlations of personal endotoxin with personal PM_2.5EC and OC, but not personal PM_2.5mass or stationary site air pollutant measurements. Outdoor home, indoor home and ambient endotoxin were moderately to strongly correlated with each other. However, in mixed models, personal endotoxin was not associated with indoor home or outdoor home endotoxin, but was associated with ambient endotoxin. Dog and cat ownership were significantly associated with increased personal but not indoor endotoxin.</p> <p>Conclusions</p> <p>Daily fixed site measurements of endotoxin in the home environment may not predict daily personal exposure, although a larger sample size may be needed to assess this. This conclusion is relevant to short-term exposures involved in the acute exacerbation of asthma.</p

Muscle Loss Is Associated with Overall Survival in Patients with Metastatic Colorectal Cancer Independent of Tumor Mutational Status and Weight Loss

Background: Survival in patients with metastatic colorectal cancer (mCRC) has been associated with tumor mutational status, muscle loss, and weight loss. We sought to explore the combined effects of these variables on overall survival. Materials and methods: We performed an observational cohort study, prospectively enrolling patients receiving chemotherapy for mCRC. We retrospectively assessed changes in muscle (using computed tomography) and weight, each dichotomized as >5% or ≤5% loss, at 3, 6, and 12 months after diagnosis of mCRC. We used regression models to assess relationships between tumor mutational status, muscle loss, weight loss, and overall survival. Additionally, we evaluated associations between muscle loss, weight loss, and tumor mutational status. Results: We included 226 patients (mean age 59 ± 13 years, 53% male). Tumor mutational status included 44% wild type, 42% RAS-mutant, and 14% BRAF-mutant. Patients with >5% muscle loss at 3 and 12 months experienced worse survival controlling for mutational status and weight (3 months hazard ratio, 2.66; p 5% muscle loss with BRAF-mutational status at 6 and 12 months. Weight loss was not associated with survival nor mutational status. Conclusion: Increased muscle loss at 3 and 12 months may identify patients with mCRC at risk for decreased overall survival, independent of tumor mutational status. Specifically, >5% muscle loss identifies patients within each category of tumor mutational status with decreased overall survival in our sample. Our findings suggest that quantifying muscle loss on serial computed tomography scans may refine survival estimates in patients with mCRC. Implications for practice: In this study of 226 patients with metastatic colorectal cancer, it was found that losing >5% skeletal muscle at 3 and 12 months after the diagnosis of metastatic disease was associated with worse overall survival, independent of tumor mutational status and weight loss. Interestingly, results did not show a significant association between weight loss and overall survival. These findings suggest that muscle quantification on serial computed tomography may refine survival estimates in patients with metastatic colorectal cancer beyond mutational status

Interleukin-6 inhibitors reduce mortality in coronavirus disease-2019: An individual patient data meta-analysis from randomized controlled trials

Objective: To assess the efficacy of IL-6 inhibitors compared to standard of care (SOC) in COVID-19 patients. Data Sources: A systematic review of the MEDLINE and Scopus databases (last search: October 8th, 2021) was performed according to the PRISMA statement. Study Selection: Randomized control trials (RCTs) comparing IL-6 inhibitors to SOC in hospitalized COVID-19 patients were deemed eligible. Data Extraction and Synthesis: Individual patient data were extracted from the Kaplan-Meier curves or were obtained from authors of included studies. Additionally, the reviewers independently abstracted data and assessed study quality of each eligible report. Results: Eleven studies were identified, incorporating 7467 patients (IL-6 inhibitors: 4103, SOC: 3364). IL-6 inhibitors were associated with decreased risk for death compared to SOC at the one-stage meta-analysis (Hazard Ratio [HR]: 0.75, 95% Confidence interval [CI]: 0.69–0.82, p&lt;0.0001) and the two-stage meta-analysis (HR: 0.85, 95%CI: 0.77–0.93, p&lt;0.001, I2 = 0.0%). Meta-regression analysis revealed that the difference in OS between the two groups was not influenced by the mean age of patients. At secondary meta-analyses, IL-6 inhibitors were associated with decreased odds for intubation OR:0.74, 95%CI:0.65–0.85, p&lt;0.001, I2=0.0%). IL-6 inhibitors were associated with increased odds for discharge compared to SOC (OR:1.28, 95% CI:1.15–1.42, p&lt;0.001, I2=0.0%). Conclusions and Relevance: This meta-analysis of individual patient data from randomized trials shows that IL-6 inhibitors significantly reduce the risk of death compared to SOC. IL-6 inhibitors are also associated with better outcomes in terms of intubation and discharge rates compared to SOC. © 202

Recognition of Specific DNA Sequences by Stacked Pyrrole- and Imidazole- Containing Polyamides: An Efficient Screening Method Based on Competitive Dialysis

A competitive dialysis method has been developed to screen compounds for their DNA binding properties, and it is based on directly comparing the binding of polyamide molecules to a series of distinctively varied, short, synthetic deoxyribonucleotides. Relative binding ratios for each polyamideoligonucleotide pairing were calculated from the concentrations of free polyamide and total polyamide in order to quantitatively compare binding to different DNA sequences. This approach works well as a preliminary screen to determine the viability of novel small molecules, prior to investing significant resources in further characterization and development of possible sequence specific DNA targeted therapeutic agents. The trends in binding affinities of the four triamide molecules (f-ImPyIm, distamycin A, f-PyPyPy and f-ImImPy; where Im is imidazole and Py is pyrrole) correlated well with data obtained from surface plasmon resonance (SPR) studies. Results from circular dichroism studies confirmed the minor groove side-by-side stacked binding motif of the triamides, and thermal stability experiments corroborated the improved DNA stability of promising polyamide-DNA complexes. The affinity of distamycin A for its cognate DNA sequence (A3T3) was unambiguously selected over the other DNA sequences tested. Alternatively, as expected from SPR, circular dichroism and thermal melting experiments, f-ImImPy showed very poor affinity for DNA sequences tested, including its cognate DNA, TCGA. Thus, the very good (distamycin A) and very poor (f-ImImPy) DNA binders were effectively screened

Targeting the inverted CCAAT box 2 in the topoisomerase IIα promoter by \u3cstrong\u3eJH-37\u3c/strong\u3e, an imidazole-pyrrole polyamide hairpin: design, synthesis, molecular biology, and biophysical studies

The topoisomerase IIα promoter is regulated through transcription factor interactions with five inverted CCAAT boxes (ICBs). In confluent cancer cells, binding of nuclear factor Y to ICB2 represses the expression of this gene, contributing to resistance to topoisomerase II poisons. The ICB sites within the topoisomerase IIα promoter are, therefore, potential targets for the design of anticancer drugs and gene control agents. The synthesis and DNA binding properties of a hairpin polyamide molecule (JH-37) that targets 5‘-TTGGT-3‘ found in ICB2 and ICB3 sites are described. Gel shift and DNase I footprinting studies on the topoisomerase IIα promoter showed JH-37 to preferentially bind to ICB2,3 and ICB1 sites. The larger ΔTM values for ICB2,3 (8−9 °C) over ICB1,4,5 (4−5 °C) indicated a preference of JH-37 for ICB2,3. CD titration studies confirmed the binding of JH-37 to the minor groove, with a 1:1 binding stoichiometry. Results from SPR studies showed JH-37 to bind most strongly to ICB2 (K = 3 × 107 M-1), followed by ICB1, the non-ICB sequence (TGCA), and finally the ICB mutant (ICB2m). The improved binding to ICB2 is largely due to a lower dissociation rate of the compound at the preferred site. To our knowledge, this is the first example on the use of SPR for studying the interactions of hairpin polyamides with DNA. Binding of JH-37 to ICB2 was corroborated by ITC studies, in which the ΔG° of binding is driven by both enthalpy and entropy. With knowledge of the fundamental thermodynamic and kinetic properties that govern the molecular recognition of polyamides with DNA, we are poised to systematically edit the structure of JH-37 in order to further enhance its binding affinity and selectivity for ICB2,3. Our strategy for designing molecules that control gene expression is to target shorter, but multiple, binding sites that are in close array within the promoter. Binding of JH-37 to multiple ICB sites in the topoisomerase IIα promoter is an ideal test for this strategy. This approach is in contrast to the traditional strategy of targeting 15−16 base pairs, which has not been successful in actual biological systems due to poor cell uptake and distribution

Preoperative sensitivity and specificity for early-stage ovarian cancer when combining cancer antigen CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor using mixtures of multivariate normal distributions

Purpose In CA-125–based ovarian cancer screening trials, overall specificity and screening sensitivity of ultrasound after an elevated CA-125 exceeded 99.6% and 70%, respectively, thereby yielding a positive predictive value (PPV) exceeding 10%. However, sensitivity for early-stage disease was only 40%. This study aims to increase preoperative sensitivity for early-stage ovarian cancer while maintaining the annual referral rate to ultrasound at 2% by combining information across CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor (M-CSF). For direct comparisons between marker panels, all sensitivity results correspond to a 98% fixed first-line specificity (referral rate 2%). Patients and Methods Logistic regression, classification tree, and mixture discriminant analysis (MDA) models were fit to a training data set of preoperative serum measurements (63 patients, 126 healthy controls) from one center. Estimates from the training set applied to an independent validation set (60 stage I to II patients, 98 healthy controls) from two other centers provided unbiased estimates of sensitivity. Results Preoperative sensitivities for early-stage disease of the optimal panels were 45% for CA-125II; 67% for CA-125II and CA 72-4; 70% for CA-125II, CA 72-4, and M-CSF; and 68% for all four markers (latter two results using MDA). Conclusion Efficiently combining information on CA-125II, CA 72-4, and M-CSF significantly increased preoperative early-stage sensitivity from 45% with CA-125II alone to 70%, while maintaining 98% first-line specificity. Screening trials with these markers using MDA followed by referral to ultrasound may maintain previously high levels of specificity and PPV, while significantly increasing early-stage screening sensitivity. MDA is a useful, biologically justified method for combining biomarkers

Sentinel lymph node biopsy at the time of mastectomy does not increase the risk of lymphedema: implications for prophylactic surgery

Women diagnosed with or at high risk for breast cancer increasingly choose prophylactic mastectomy. It is unknown if adding sentinel lymph node biopsy (SLNB) to prophylactic mastectomy increases the risk of lymphedema. We sought to determine the risk of lymphedema after mastectomy with and without nodal evaluation. 117 patients who underwent bilateral mastectomy were prospectively screened for lymphedema. Perometer arm measurements were used to calculate weight-adjusted arm volume change at each follow-up. Of 234 mastectomies performed, 15.8 % (37/234) had no axillary surgery, 63.7 % (149/234) had SLNB, and 20.5 % (48/234) had axillary lymph node dissection (ALND). 88.0 % (103/117) of patients completed the LEFT-BC questionnaire evaluating symptoms associated with lymphedema. Multivariate analysis was used to assess clinical characteristics associated with increased weight-adjusted arm volume and patient-reported lymphedema symptoms. SLNB at the time of mastectomy did not result in an increased mean weight-adjusted arm volume compared to mastectomy without axillary surgery (p = 0.76). Mastectomy with ALND was associated with a significantly greater mean weight-adjusted arm volume change compared to mastectomy with SLNB (p < 0.0001) and without axillary surgery (p = 0.0028). Patients who underwent mastectomy with ALND more commonly reported symptoms associated with lymphedema compared to those with SLNB or no axillary surgery (p < 0.0001). Patients who underwent mastectomy with SLNB or no axillary surgery reported similar lymphedema symptoms. Addition of SLNB to mastectomy is not associated with a significant increase in measured or self-reported lymphedema rates. Therefore, SLNB may be performed at the time of prophylactic mastectomy without an increased risk of lymphedema

Extending the language of DNA molecular recognition by polyamides: unexpected influence of imidazole and pyrrole arrangement on binding affinity and specificity

Pyrrole (Py) and imidazole (Im) polyamides can be designed to target specific DNA sequences. The effect that the pyrrole and imidazole arrangement, plus DNA sequence, have on sequence specificity and binding affinity has been investigated using DNA melting (DeltaT(M)), circular dichroism (CD), and surface plasmon resonance (SPR) studies. SPR results obtained from a complete set of triheterocyclic polyamides show a dramatic difference in the affinity of f-ImPyIm for its cognate DNA (K(eq) = 1.9 x 10(8) M(-1)) and f-PyPyIm for its cognate DNA (K(eq) = 5.9 x 10(5) M(-1)), which could not have been anticipated prior to characterization of these compounds. Moreover, f-ImPyIm has a 10-fold greater affinity for CGCG than distamycin A has for its cognate, AATT. To understand this difference, the triamide dimers are divided into two structural groupings: central and terminal pairings. The four possible central pairings show decreasing selectivity and affinity for their respective cognate sequences: -ImPy \u3e -PyPy- \u3e -PyIm- approximately -ImIm-. These results extend the language of current design motifs for polyamide sequence recognition to include the use of words for recognizing two adjacent base pairs, rather than letters for binding to single base pairs. Thus, polyamides designed to target Watson-Crick base pairs should utilize the strength of -ImPy- and -PyPy- central pairings. The f/Im and f/Py terminal groups yielded no advantage for their respective C/G or T/A base pairs. The exception is with the -ImPy- central pairing, for which f/Im has a 10-fold greater affinity for C/G than f/Py has for T/A