Politics matters for individual attitudes toward vaccine donation: cross-national evidence from the United States and Taiwan.

BACKGROUND: Vaccine equity has been a major concern during the COVID-19 pandemic. According to the principle of vaccine equity, donor countries should apply the criterion of needs to make decisions about vaccine donation instead of considering recipient countries' economic status. We examine whether people follow the same criterion or consider other factors to decide which country to donate vaccines and how many vaccines should be delivered. METHODS: We conducted online surveys with the design of conjoint experiment in the United States and Taiwan in 2021. 1,532 American citizens and 1,587 Taiwanese citizens were interviewed. The respondents were broadly quota-matched to their respective demographic proportions on the dimensions of age, gender, and education. We estimated the average marginal component effects (AMCEs) of the conjoint attributes by using the OLS regression models with standard errors clustered at the respondent level. RESULTS: 15,320 and 15,870 decisions on vaccine donation generated by conjoint experiment respectively in the United States and Taiwan were included in the analysis. Both American and Taiwanese people tend to donate vaccines to countries that suffer severe consequences of COVID-19 and democracies compared to authoritarian countries. However, they are less willing to donate vaccines to those with higher levels of capability in response to COVID-19. Taiwanese people tend to donate vaccines to countries having formal diplomatic relations with Taiwan (AMCE 13.4%, 95% CI 11.8%-15.1%). Nonetheless, American people would rather donate vaccines to countries without formal diplomatic relations with the United States (AMCE - 4.0%, 95% CI -5.6%--2.4%). CONCLUSIONS: The findings reveal that politics plays a significant role in people's decisions about vaccine donation. Under electoral pressure, political leaders must think about how to respond to the public's preferences over vaccine donation to achieve vaccine equity and address the global health crisis.

Regulation of Aqueous Humor Secretion by Melatonin in Porcine Ciliary Epithelium.

Secretion of melatonin, a natural hormone whose receptors are present in the ciliary epithelium, displays diurnal variation in the aqueous humor (AH), potentially contributing to the regulation of intraocular pressure. This study aimed to determine the effects of melatonin on AH secretion in porcine ciliary epithelium. The addition of 100 µM melatonin to both sides of the epithelium significantly increased the short-circuit current (Isc) by ~40%. Stromal administration alone had no effect on the Isc, but aqueous application triggered a 40% increase in Isc, similar to that of bilateral application without additive effect. Pre-treatment with niflumic acid abolished melatonin-induced Isc stimulation. More importantly, melatonin stimulated the fluid secretion across the intact ciliary epithelium by ~80% and elicited a sustained increase (~50-60%) in gap junctional permeability between pigmented ciliary epithelial (PE) cells and non-pigmented ciliary epithelial (NPE) cells. The expression of MT3 receptor was found to be >10-fold higher than that of MT1 and MT2 in porcine ciliary epithelium. Aqueous pre-treatment with MT1/MT2 antagonist luzindole failed to inhibit the melatonin-induced Isc response, while MT3 antagonist prazosin pre-treatment abolished the Isc stimulation. We conclude that melatonin facilitates Cl- and fluid movement from PE to NPE cells, thereby stimulating AH secretion via NPE-cell MT3 receptors.

Inhibitors of Coronavirus 3CL Proteases Protect Cells from Protease-Mediated Cytotoxicity.

We describe a mammalian cell-based assay to identify coronavirus 3CL protease (3CLpro) inhibitors. This assay is based on rescuing protease-mediated cytotoxicity and does not require live virus. By enabling the facile testing of compounds across a range of 15 distantly related coronavirus 3CLpro enzymes, we identified compounds with broad 3CLpro-inhibitory activity. We also adapted the assay for use in compound screening and in doing so uncovered additional severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3CLpro inhibitors. We observed strong concordance between data emerging from this assay and those obtained from live-virus testing. The reported approach democratizes the testing of 3CLpro inhibitors by developing a simplified method for identifying coronavirus 3CLpro inhibitors that can be used by the majority of laboratories, rather than the few with extensive biosafety infrastructure. We identified two lead compounds, GC376 and compound 4, with broad activity against all 3CL proteases tested, including 3CLpro enzymes from understudied zoonotic coronaviruses. IMPORTANCE Multiple coronavirus pandemics have occurred over the last 2 decades. This has highlighted a need to be proactive in the development of therapeutics that can be readily deployed in the case of future coronavirus pandemics. We developed and validated a simplified cell-based assay for the identification of chemical inhibitors of 3CL proteases encoded by a wide range of coronaviruses. This assay is reporter free, does not require specialized biocontainment, and is optimized for performance in high-throughput screening. By testing reported 3CL protease inhibitors against a large collection of 3CL proteases with variable sequence similarity, we identified compounds with broad activity against 3CL proteases and uncovered structural insights into features that contribute to their broad activity. Furthermore, we demonstrated that this assay is suitable for identifying chemical inhibitors of proteases from families other than 3CL proteases.

PM2.5 exposure and risk of lung adenocarcinoma in women of Taiwan: A case-control study with density sampling.

BACKGROUND AND OBJECTIVE: The prevalence of smoking among women in Taiwan is <5%, but the incidence of lung cancer remains high. This study determined the association between PM2.5 (fine particulate matter with an aerodynamic diameter of ≤2.5 µm) exposure and lung cancer among women in Taiwan. METHODS: In total, 21,301 female lung cancer cases nationwide were newly diagnosed between 2012 and 2017. Each case was age-, sex- and calendar year-matched with four controls randomly selected from the general population. Allowing a latent period of 5 years, we estimated the PM2.5 and nitrogen dioxide (NO2 ) exposures for each individual according to the residential changes from 2000. We adopted self-reported smoking statuses for the cases, while those of controls were estimated using annual surveys in each residential county. We performed multiple logistic regression analyses to examine the associations between PM2.5 and NO2 exposures and incident lung cancer cases. RESULTS: The ORs of lung adenocarcinoma for the third (30.5-35.1 µg/m3 ), fourth (35.1-39.3 µg/m3 ) and fifth PM2.5 exposure quintiles (39.3-48.1 µg/m3 ) relative to the first quintile were 1.10 (95% CI: 1.04-1.16), 1.12 (95% CI: 1.06-1.19) and 1.10 (95% CI: 1.04-1.16), respectively, after adjusting for smoking, residence and comorbidities. A dose-response relationship (p = 0.004) was found. The associations persisted with a 10-year latency and were not detected for small-cell and squamous cell carcinoma after control for smoking. We did not observe a similar effect for NO2 exposure. CONCLUSION: Residential PM2.5 exposure higher than 30 µg/m3 was associated with an increased risk of lung adenocarcinoma in women of Taiwan.

Intraoperative Needle Tip Tracking with an Integrated Fibre-Optic Ultrasound Sensor.

Ultrasound is an essential tool for guidance of many minimally-invasive surgical and interventional procedures, where accurate placement of the interventional device is critical to avoid adverse events. Needle insertion procedures for anaesthesia, fetal medicine and tumour biopsy are commonly ultrasound-guided, and misplacement of the needle may lead to complications such as nerve damage, organ injury or pregnancy loss. Clear visibility of the needle tip is therefore critical, but visibility is often precluded by tissue heterogeneities or specular reflections from the needle shaft. This paper presents the in vitro and ex vivo accuracy of a new, real-time, ultrasound needle tip tracking system for guidance of fetal interventions. A fibre-optic, Fabry-Pérot interferometer hydrophone is integrated into an intraoperative needle and used to localise the needle tip within a handheld ultrasound field. While previous, related work has been based on research ultrasound systems with bespoke transmission sequences, the new system-developed under the ISO 13485 Medical Devices quality standard-operates as an adjunct to a commercial ultrasound imaging system and therefore provides the image quality expected in the clinic, superimposing a cross-hair onto the ultrasound image at the needle tip position. Tracking accuracy was determined by translating the needle tip to 356 known positions in the ultrasound field of view in a tank of water, and by comparison to manual labelling of the the position of the needle in B-mode US images during an insertion into an ex vivo phantom. In water, the mean distance between tracked and true positions was 0.7 ± 0.4 mm with a mean repeatability of 0.3 ± 0.2 mm. In the tissue phantom, the mean distance between tracked and labelled positions was 1.1 ± 0.7 mm. Tracking performance was found to be independent of needle angle. The study demonstrates the performance and clinical compatibility of ultrasound needle tracking, an essential step towards a first-in-human study.

Delay to surgery after neoadjuvant chemotherapy in head and neck squamous cell carcinoma affects oncologic outcomes.

BACKGROUND: Neoadjuvant chemotherapy (NAC) is used in head and neck squamous cell carcinoma (HNSCC) for downstaging advanced disease and decreasing distant metastasis (DM). To the authors' knowledge, no study has specifically examined the impact of a delayed time to surgery (TTS) after NAC on oncologic outcomes. They thus aimed to identify a cutoff for TTS after NAC and its effect on survival indices. METHODS: This was a retrospective review of all patients with HNSCC receiving NAC followed by surgery with curative intent between March 2016 and March 2019 at the MD Anderson Cancer Center. Receiver operating characteristic analysis was used to identify a cutoff for TTS, and this cutoff was used to analyze the overall survival (OS), locoregional recurrence rate, DM-free rate, and disease-free survival (DFS). A multivariate Cox regression analysis was performed. RESULTS: One hundred one patients were analyzed with a median follow-up of 24.7 months. The 3-year OS and locoregional recurrence rates did not differ with a TTS ≥ 34 days. However, the 3-year DM-free rate was significantly worse (56% vs 90%; P = .001) in the group with a TTS ≥ 34 days, and the 3-year DFS was significantly lower (26% vs 64%; P = .006). In a multivariate analysis, a TTS ≥ 34 days (hazard ratio [HR], 4.92; 95% confidence interval [CI], 1.84-13.13) and extracapsular extension (HR, 3.01; 95% CI, 1.13-8.00) were significant independent predictors of a poorer DM-free rate. Weight loss > 10% (HR, 5.53; 95% CI, 1.02-30.24) was the only independent predictor for a TTS ≥ 34 days. CONCLUSIONS: Emphasis should be placed on early definitive locoregional treatment after NAC, particularly in patients who do not respond to NAC. There is a need to validate these findings and establish new benchmarks for the interval between NAC and surgery.

Potential of Magnetic Hyperthermia to Stimulate Localized Immune Activation.

Magnetic hyperthermia (MH) harnesses the heat-releasing properties of superparamagnetic iron oxide nanoparticles (SPIONs) and has potential to stimulate immune activation in the tumor microenvironment whilst sparing surrounding normal tissues. To assess feasibility of localized MH in vivo, SPIONs are injected intratumorally and their fate tracked by Zirconium-89-positron emission tomography, histological analysis, and electron microscopy. Experiments show that an average of 49% (21-87%, n = 9) of SPIONs are retained within the tumor or immediately surrounding tissue. In situ heating is subsequently generated by exposure to an externally applied alternating magnetic field and monitored by thermal imaging. Tissue response to hyperthermia, measured by immunohistochemical image analysis, reveals specific and localized heat-shock protein expression following treatment. Tumor growth inhibition is also observed. To evaluate the potential effects of MH on the immune landscape, flow cytometry is used to characterize immune cells from excised tumors and draining lymph nodes. Results show an influx of activated cytotoxic T cells, alongside an increase in proliferating regulatory T cells, following treatment. Complementary changes are found in draining lymph nodes. In conclusion, results indicate that biologically reactive MH is achievable in vivo and can generate localized changes consistent with an anti-tumor immune response.

Iron intake with the risk of breast cancer among Chinese women: a case-control study.

OBJECTIVE: The current study evaluated the associations between different forms and sources of Fe and breast cancer risk in Southern Chinese women. DESIGN: Case-control study. We collected data on the consumption of Fe from different forms and food sources by using a validated FFQ. Multivariable logistic regression and restricted cubic spline (RCS) analysis was used to reveal potential associations between Fe intake and breast cancer risk. SETTING: A case-control study of women at three major hospitals in Guangzhou, China. PARTICIPANTS: From June 2007 to March 2019, 1591 breast cancer cases and 1622 age-matched controls were recruited. RESULTS: In quartile analyses, Fe from plants and Fe from white meat intake were inversely associated with breast cancer risk, with OR of 0·65 (95 % CI 0·47, 0·89, Ptrend = 0·006) and 0·76 (95 % CI 0·61, 0·96, Ptrend = 0·014), respectively, comparing the highest with the lowest quartile. No associations were observed between total dietary Fe, heme or non-heme Fe, Fe from meat or red meat and breast cancer risk. RCS analysis demonstrated J-shaped associations between total dietary Fe, non-heme Fe and breast cancer, and reverse L-shaped associations between heme Fe, Fe from meat and Fe from red meat and breast cancer. CONCLUSION: Fe from plants and white meat were inversely associated with breast cancer risk. Significant non-linear J-shaped associations were found between total dietary Fe, non-heme Fe and breast cancer risk, and reverse L-shaped associations were found between heme Fe, Fe from meat or red meat and breast cancer risk.

Impact of neoadjuvant chemotherapy on perioperative morbidity after major surgery for head and neck cancer.

BACKGROUND: Neoadjuvant chemotherapy (NAC) has been used in patients with advanced head and neck cancers (HNCs) with the intent of downstaging tumors and suppressing distant metastases. However, to the authors' knowledge, the perioperative impact of NAC has not been systematically explored in patients with HNC. The objective of the current study was to compare perioperative outcomes with surgery upfront compared with patients treated with NAC. METHODS: Between March 1, 2016, and March 31, 2019, patients undergoing surgery for HNC with flap reconstruction at The University of Texas MD Anderson Cancer Center in Houston were included. Data were extracted from the prospectively maintained National Surgical Quality Improvement Program database. Postoperative complications, return to operating room, and readmission rates were compared. Univariate and multivariate analyses of length of stay and overall and wound complications were performed. RESULTS: A total of 834 patients were analyzed, 687 of whom (82.4%) underwent surgery upfront and 147 of whom (17.6%) received NAC. A total of 631 cases (75.7%) involved the upper aerodigestive tract whereas 203 cases (24.3%) were cutaneous. A total of 317 patients (38.0%) had recurrent disease. The NAC group was younger (P < .001) and had less hypertension (P = .011), but had more advanced clinical stage tumors (P < .001) and surgeries with multiple flap reconstruction (P = .007). Patient groups did not differ with regard to wound complications (P = .47), return to operating room (P = .31), or readmission rates (P = .49). The NAC group received more blood transfusions (P < .001) but was found to have a lower risk of overall complications on multivariate analysis (odds ratio, 0.50; 95% CI, 0.30-0.83). The overall complication rate was unchanged with surgery performed ≤21 days after the last chemotherapy cycle. CONCLUSIONS: Patients undergoing NAC appear to have a higher disease burden but tend to be younger and healthier. Within the context of this inherent selection bias, NAC does not appear to increase perioperative morbidity among patients undergoing surgery for HNC.

Improved Modeling of Cation-π and Anion-Ring Interactions Using the Drude Polarizable Empirical Force Field for Proteins.

Cation-π interactions are noncovalent interactions between a π-electron system and a positively charged ion that are regarded as a strong noncovalent interaction and are ubiquitous in biological systems. Similarly, though less studied, anion-ring interactions are present in proteins along with in-plane interactions of anions with aromatic rings. As these interactions are between a polarizing ion and a polarizable π system, the accuracy of the treatment of these interactions in molecular dynamics (MD) simulations using additive force fields (FFs) may be limited. In the present work, to allow for a better description of ion-π interactions in proteins in the Drude-2013 protein polarizable FF, we systematically optimized the parameters for these interactions targeting model compound quantum mechanical (QM) interaction energies with atom pair-specific Lennard-Jones parameters along with virtual particles as selected ring centroids introduced to target the QM interaction energies and geometries. Subsequently, MD simulations were performed on a series of protein structures where ion-π pairs occur to evaluate the optimized parameters in the context of the Drude-2013 FF. The resulting FF leads to a significant improvement in reproducing the ion-π pair distances observed in experimental protein structures, as well as a smaller root-mean-square differences and fluctuations of the overall protein structures from experimental structures. Accordingly, the optimized Drude-2013 protein polarizable FF is suggested for use in MD simulations of proteins where cation-π and anion-ring interactions are critical. © 2019 Wiley Periodicals, Inc.

Intake of total cruciferous vegetable and its contents of glucosinolates and isothiocyanates, glutathione S-transferases polymorphisms and breast cancer risk: a case-control study in China.

Cruciferous vegetables contain high levels of glucosinolates (GSL) and isothiocyanates (ITC). ITC are known to induce glutathione S-transferases (GST) and thus exert their anticarcinogenic effects. This study explored the combined effects of cruciferous vegetable, GSL and ITC intake and GST polymorphisms on breast cancer risk. A total of 737 breast cancer cases and 756 controls were recruited into this case-control study. OR and 95 % CI were assessed by multivariable logistic regression. Higher cruciferous vegetable, GSL and ITC intakes were inversely associated with breast cancer risk, with adjusted OR of 0·48 (95 % CI 0·35, 0·65), 0·54 (95 % CI 0·40, 0·74) and 0·62 (95 % CI 0·45, 0·84), respectively. Compared with women carrying the GSTP1 rs1695 wild AA genotype and high cruciferous vegetable, GSL or ITC intake, carriers of the AA genotype with low cruciferous vegetable, GSL and ITC intake had greater risk of breast cancer, with adjusted OR of 1·43 (95 % CI 1·01, 1·87), 1·34 (95 % CI 1·02, 1·75) and 1·37 (95 % CI 1·05, 1·80), respectively. Persons with the GSTM1-null genotype and lower intake of cruciferous vegetables, GSL and ITC had higher risk of breast cancer than those with the GSTM1-present genotype and higher intake, with OR of 1·42 (95 % CI 1·04, 1·95), 1·43 (95 % CI 1·05, 1·96) and 1·45 (95 % CI 1·06, 1·98), respectively. Among women possessing the GSTT1-present genotype, low intake of cruciferous vegetables, GSL or ITC was associated with higher risk of breast cancer. But these interactions were non-significant. This study indicated that there were no significant interactions between cruciferous vegetable, GSL or ITC intake and GST polymorphisms on breast cancer risk.

Personality and individual attitudes toward vaccination: a nationally representative survey in the United States.

BACKGROUND: Although past studies have identified factors associated with individual perceptions of vaccination, limited attention has been paid to the role of personality in individual attitudes toward vaccination. This study aimed to evaluate the effect of personality as measured by the Big Five personality traits on individual attitudes toward vaccination using a nationally representative survey in the United States. METHODS: A cross-sectional study was conducted with a sample of 3276 American citizens who were aged 18 and above and lived in 50 U.S. states and Washington D.C. from the American National Election Studies. The survey was collected through face-to-face and online interviews using structured questionnaires in 2016. The multistage stratified cluster sampling procedure was used for face-to-face interview, whereas the USPS DSF was used to select the sample for online interview. Multivariable ordinal logistic regression was used to assess how personality traits (extraversion, agreeableness, conscientiousness, emotional stability, and openness to experience) as main explanatory variables influence the outcome variables - individual attitudes toward health benefits of vaccination and support for school vaccination. RESULTS: More than two-thirds of respondents perceive health benefit of vaccination and support vaccination requirements for school entry, whereas about one-tenth of respondents have safety concerns about vaccination and oppose the vaccination requirements. After adjusting for ideology, insurance status, and demographic variables, the traits of agreeableness, conscientiousness and emotional stability remain significantly associated with attitude toward vaccination; conscientiousness is significantly associated with support for school vaccination. The odds of reporting health benefits of vaccination associated with one-point increase in agreeableness, conscientiousness and emotional stability are 1.05 (95% confidence intervals [CI] = 1.01-1.08), 1.05 (95% CI = 1.02-1.09) and 1.03 (95% CI = 1.00-1.06), respectively. For a one-point increase in conscientiousness, the odds of supporting school vaccination increase by 1.08 (95% CI = 1.05-1.12). CONCLUSIONS: People high in agreeableness, conscientiousness and emotional stability are more likely to regard vaccination as beneficial, whereas those high in conscientiousness are more likely to support school-based vaccine requirement. This study highlights the importance of personality in shaping individual attitudes toward vaccination. More research is needed to understand the role of personality in individual health attitudes and behavior.

Improved Modeling of Halogenated Ligand-Protein Interactions Using the Drude Polarizable and CHARMM Additive Empirical Force Fields.

Halogenated ligands can participate in nonbonding interactions with proteins via halogen bond (XB) or halogen-hydrogen bond donor (X-HBD) interactions. In the context of molecular dynamics (MD) simulations, the accuracy of the simulations depends strongly on the force field (FF) used. To ensure good reproduction of XB and X-HBD interactions with proteins, we optimized the previously developed additive CHARMM36/CHARMM General force field (CGenFF) and Drude polarizable force field by including atom pair-specific Lennard-Jones parameters for aromatic halogen-protein interactions. The optimization targeted quantum mechanical interaction energy surfaces with the developed parameters then examined for their ability to reproduce experimental halogen-containing ligand-protein interactions in MD simulations. The calculated halogenated ligand interaction geometries were in good overall agreement with the experimental crystal data for both the polarizable and additive FFs, showing that these models can accurately treat both XB and X-HBD interactions. Analysis of the ligand-protein interactions shows significant contributions of polarizability to binding occurring in the Drude FF, with self-polarization energy making both favorable and unfavorable contributions to binding. Further analysis of the dipole moments from aqueous solution to protein indicates the polarizable FF accounts for subtle changes of the environment of the ligands that can impact binding. The present work demonstrates the utility of the updated additive CHARMM36/CGenFF and polarizable Drude FFs for the study of halogenated ligand-protein interactions in computer-aided drug design.

Combining the polarizable Drude force field with a continuum electrostatic Poisson-Boltzmann implicit solvation model.

In this work, we have combined the polarizable force field based on the classical Drude oscillator with a continuum Poisson-Boltzmann/solvent-accessible surface area (PB/SASA) model. In practice, the positions of the Drude particles experiencing the solvent reaction field arising from the fixed charges and induced polarization of the solute must be optimized in a self-consistent manner. Here, we parameterized the model to reproduce experimental solvation free energies of a set of small molecules. The model reproduces well-experimental solvation free energies of 70 molecules, yielding a root mean square difference of 0.8 kcal/mol versus 2.5 kcal/mol for the CHARMM36 additive force field. The polarization work associated with the solute transfer from the gas-phase to the polar solvent, a term neglected in the framework of additive force fields, was found to make a large contribution to the total solvation free energy, comparable to the polar solute-solvent solvation contribution. The Drude PB/SASA also reproduces well the electronic polarization from the explicit solvent simulations of a small protein, BPTI. Model validation was based on comparisons with the experimental relative binding free energies of 371 single alanine mutations. With the Drude PB/SASA model the root mean square deviation between the predicted and experimental relative binding free energies is 3.35 kcal/mol, lower than 5.11 kcal/mol computed with the CHARMM36 additive force field. Overall, the results indicate that the main limitation of the Drude PB/SASA model is the inability of the SASA term to accurately capture non-polar solvation effects. © 2018 Wiley Periodicals, Inc.

Glucosinolate and isothiocyanate intakes are inversely associated with breast cancer risk: a case-control study in China.

Although previous studies have investigated the association of cruciferous vegetable consumption with breast cancer risk, few studies focused on the association between bioactive components in cruciferous vegetables, glucosinolates (GSL) and isothiocyanates (ITC), and breast cancer risk. This study aimed to examine the association between consumption of cruciferous vegetables and breast cancer risk according to GSL and ITC contents in a Chinese population. A total of 1485 cases and 1506 controls were recruited into this case-control study from June 2007 to March 2017. Consumption of cruciferous vegetables was assessed using a validated FFQ. Dietary GSL and ITC were computed by using two food composition databases linking GSL and ITC contents in cruciferous vegetables with responses to the FFQ. The OR and 95 % CI were assessed by unconditional logistic regression after adjusting for the potential confounders. Significant inverse associations were found between consumption of cruciferous vegetables, GSL and ITC and breast cancer risk. The adjusted OR comparing the highest with the lowest quartile were 0·51 (95 % CI 0·41, 0·63) for cruciferous vegetables, 0·54 (95 % CI 0·44, 0·67) for GSL and 0·62 (95 % CI 0·50, 0·76) for ITC, respectively. These inverse associations were also observed in both premenopausal and postmenopausal women. Subgroup analysis by hormone receptor status found inverse associations between cruciferous vegetables, GSL and ITC and both hormone-receptor-positive or hormone-receptor-negative breast cancer. This study indicated that consumption of cruciferous vegetables, GSL and ITC was inversely associated with breast cancer risk among Chinese women.

Polarizable Force Field for Molecular Ions Based on the Classical Drude Oscillator.

Development of accurate force field parameters for molecular ions in the context of a polarizable energy function based on the classical Drude oscillator is a crucial step toward an accurate polarizable model for modeling and simulations of biological macromolecules. Toward this goal we have undertaken a hierarchical approach in which force field parameter optimization is initially performed for small molecules for which experimental data exists that serve as building blocks of macromolecular systems. Small molecules representative of the ionic moieties of biological macromolecules include the cationic ammonium and methyl substituted ammonium derivatives, imidazolium, guanidinium and methylguanidinium, and the anionic acetate, phenolate, and alkanethiolates. In the present work, parameters for molecular ions in the context of the Drude polarizable force field are optimized and compared to results from the nonpolarizable additive CHARMM general force field (CGenFF). Electrostatic and Lennard-Jones parameters for the model compounds are developed in the context of the polarizable SWM4-NDP water model, with emphasis on assuring that the hydration free energies are consistent with previously reported parameters for atomic ions. The final parameters are shown to be in good agreement with the selected quantum mechanical (QM) and experimental target data. Analysis of the structure of water around the ions reveals substantial differences between the Drude and additive force fields indicating the important role of polarization in dictating the molecular details of aqueous solvation. The presented parameters represent the foundation for the charged functionalities in future generations of the Drude polarizable force field for biological macromolecules as well as for drug-like molecules.

Conformational dynamics of cathepsin D and binding to a small-molecule BACE1 inhibitor.

BACE1 is a major therapeutic target for prevention and treatment of Alzheimer's disease. Developing inhibitors that can selectively target BACE1 in favor of other proteases, especially cathepsin D (CatD), has presented significant challenges. Here, we investigate the conformational dynamics and protonation states of BACE1 and CatD using continuous constant pH molecular dynamics with pH replica-exchange sampling protocol. Despite similar structure, BACE1 and CatD exhibit markedly different active site dynamics. BACE1 displays pH-dependent flap dynamics that controls substrate accessibility, while the CatD flap is relatively rigid and remains open in the pH range 2.5-6. Interestingly, although each protease hydrolyzes peptide bonds, the protonation states of the catalytic dyads are different within the active pH range. The acidic and basic components of the BACE1 catalytic dyad are clear, while either aspartic acid of the CatD catalytic dyad could play the role of acid or base. Finally, we investigate binding of the inhibitor LY2811376 developed by Eli Lilly to BACE1 and CatD. Surprisingly, in the enzyme active pH range, LY2811376 forms a stronger salt bridge with the catalytic dyad in CatD than in BACE1, which might explain the retinal toxicity of the inhibitor related to off-target inhibition of CatD. This work highlights the complexity and challenge in structure-based drug design where receptor-ligand binding induces protonation state change in both the protein and the inhibitor. © 2017 Wiley Periodicals, Inc.

Beneficial Effect of Educational and Nutritional Intervention on the Nutritional Status and Compliance of Gastric Cancer Patients Undergoing Chemotherapy: A Randomized Trial.

Surgery combined with chemotherapy is the standard treatment for gastric cancer (GC); however, chemotherapy-relative adverse effects are common and result in malnutrition and a poor prognosis. In addition, compliance to postoperative chemotherapy remains a problem. This study aimed to prospectively investigate the effect of educational and nutritional interventions on the nutritional status and compliance of GC patients undergoing postoperative chemotherapy. A total of 144 GC patients were randomized into an intervention group that received intensive individualized nutritional and educational interventions during the entire course of chemotherapy and control group that received basic nutrition care and health education during hospitalization. The nutritional status and compliance between the two groups were compared. The interventions significantly improved calorie and iron intake within 24 h after the first chemotherapy session, and improved patients' weight, hemoglobin, total serum protein, and albumin levels during the entire course of chemotherapy. The compliance rate with chemotherapy was significantly higher in the intervention group than in the control group (73.61% vs. 55.56%, P = 0.024). A combination of nutritional and educational interventions provided beneficial effect on the nutrition status and compliance of gastric patients undergoing postoperative chemotherapy, which is worthy of clinical application.

A higher Dietary Inflammatory Index score is associated with a higher risk of breast cancer among Chinese women: a case-control study.

Previous studies have investigated the association between dietary inflammatory potential and the development of cancer. For breast cancer the results have been equivocal. The present study aimed to investigate whether higher Dietary Inflammatory IndexTM (DII) scores were associated with increased risk of breast cancer among Chinese women. A total of 867 cases and 824 controls were recruited into the present case-control study from September 2011 to February 2016. DII scores were computed based on baseline dietary intake assessed by a validated 81-item FFQ. The OR and 95 % CI were assessed by multivariable logistic regression after adjusting for various potential confounders. DII scores in this study ranged from -5·87 (most anti-inflammatory score) to +5·71 (most proinflammatory score). A higher DII score was associated with a higher breast cancer risk (adjusted ORquartile 4 v. 1 2·28; 95 % CI 1·71, 3·03; adjusted ORcontinuous 1·40; 95 %CI 1·25, 1·39). In stratified analyses, positive associations also were observed except for underweight women or women with either oestrogen receptor+ or progesterone receptor+ status (but not both). Results from this study indicated that higher DII scores, corresponding to more proinflammatory diets, were positively associated with breast cancer risk among Chinese women.

Drude polarizable force field for aliphatic ketones and aldehydes, and their associated acyclic carbohydrates.

The majority of computer simulations exploring biomolecular function employ Class I additive force fields (FF), which do not treat polarization explicitly. Accordingly, much effort has been made into developing models that go beyond the additive approximation. Development and optimization of the Drude polarizable FF has yielded parameters for selected lipids, proteins, DNA and a limited number of carbohydrates. The work presented here details parametrization of aliphatic aldehydes and ketones (viz. acetaldehyde, propionaldehyde, butaryaldehyde, isobutaryaldehyde, acetone, and butanone) as well as their associated acyclic sugars (D-allose and D-psicose). LJ parameters are optimized targeting experimental heats of vaporization and molecular volumes, while the electrostatic parameters are optimized targeting QM water interactions, dipole moments, and molecular polarizabilities. Bonded parameters are targeted to both QM and crystal survey values, with the models for ketones and aldehydes shown to be in good agreement with QM and experimental target data. The reported heats of vaporization and molecular volumes represent a compromise between the studied model compounds. Simulations of the model compounds show an increase in the magnitude and the fluctuations of the dipole moments in moving from gas phase to condensed phases, which is a phenomenon that the additive FF is intrinsically unable to reproduce. The result is a polarizable model for aliphatic ketones and aldehydes including the acyclic sugars D-allose and D-psicose, thereby extending the available biomolecules in the Drude polarizable FF.