Translating Mechanism-Based Strategies to Break the Obesity−Cancer Link: A Narrative Review

Prevalence of obesity, an established risk factor for many cancers, has increased dramatically over the past 50 years in the United States and across the globe. Relative to normoweight cancer patients, obese cancer patients often have poorer prognoses, resistance to chemotherapies, and are more likely to develop distant metastases. Recent progress on elucidating the mechanisms underlying the obesity?cancer connection suggests that obesity exerts pleomorphic effects on pathways related to tumor development and progression and, thus, there are multiple opportunities for primary prevention and treatment of obesity-related cancers. Obesity-associated alterations, including systemic metabolism, adipose inflammation, growth factor signaling, and angiogenesis, are emerging as primary drivers of obesity-associated cancer development and progression. These obesity-associated host factors interact with the intrinsic molecular characteristics of cancer cells, facilitating several of the hallmarks of cancer. Each is considered in the context of potential preventive and therapeutic strategies to reduce the burden of obesity-related cancers. In addition, this review focuses on emerging mechanisms behind the obesity?cancer link, as well as relevant dietary interventions, including calorie restriction, intermittent fasting, low-fat diet, and ketogenic diet, that are being implemented in preclinical and clinical trials, with the ultimate goal of reducing incidence and progression of obesity-related cancers.     

Evaluation of Hydrogen Exchange Mass Spectrometry as a Stability-Indicating Method for Formulation Excipient Screening for an IgG4 Monoclonal Antibody

Antibodies are molecules that exhibit diverse conformational changes on different timescales, and there is ongoing interest to better understand the relationship between antibody conformational dynamics and storage stability. Physical stability data for an IgG4 monoclonal antibody (mAb-D) were gathered through traditional forced degradation (temperature and stirring stresses) and accelerated stability studies, in the presence of different additives and solution conditions, as measured by differential scanning calorimetry, size exclusion chromatography, and microflow imaging. The results were correlated with hydrogen exchange mass spectrometry (HX-MS) data gathered for mAb-D in the same formulations. Certain parameters of the HX-MS data, including hydrogen exchange in specific peptide segments in the C_H2 domain, were found to correlate with stabilization and destabilization of additives on mAb-D during thermal stress. No such correlations between mAb physical stability and HX-MS readouts were observed under agitation stress. These results demonstrate that HX-MS can be set up as a streamlined methodology (using minimal material and focusing on key peptide segments at key time points) to screen excipients for their ability to physically stabilize mAbs. However, useful correlations between HX-MS and either accelerated or real-time stability studies will be dependent on a particular mAb's degradation pathway(s) and the type of stresses used.     

Impact of Glycosylation on the Local Backbone Flexibility of Well-Defined IgG1-Fc Glycoforms Using Hydrogen Exchange-Mass Spectrometry

We have used hydrogen exchange–mass spectrometry to characterize local backbone flexibility of 4 well-defined IgG1-Fc glycoforms expressed and purified from Pichia pastoris, 2 of which were prepared using subsequent in vitro enzymatic treatments. Progressively decreasing the size of the N-linked N297 oligosaccharide from high mannose (Man8-Man12), to Man5, to GlcNAc, to nonglycosylated N297Q resulted in progressive increases in backbone flexibility. Comparison of these results with recently published physicochemical stability and Fcγ receptor binding data with the same set of glycoproteins provide improved insights into correlations between glycan structure and these pharmaceutical properties. Flexibility significantly increased upon glycan truncation in 2 potential aggregation-prone regions. In addition, a correlation was established between increased local backbone flexibility and increased deamidation at asparagine 315. Interestingly, the opposite trend was observed for oxidation of tryptophan 277 where faster oxidation correlated with decreased local backbone flexibility. Finally, a trend of increasing C'E glycopeptide loop flexibility with decreasing glycan size was observed that correlates with their FcγRIIIa receptor binding properties. These well-defined IgG1-Fc glycoforms serve as a useful model system to identify physicochemical stability and local backbone flexibility data sets potentially discriminating between various IgG glycoforms for potential applicability to future comparability or biosimilarity assessments.     

Demonstration of In Vitro Host-Guest Complex Formation and Safety of para-Sulfonatocalix[8]arene as a Delivery Vehicle for Two Antibiotic Drugs

The macrocycle para-sulfonatocalix[8]arene, sCX[8], was examined with 2 antibiotic drugs, ciprofloxacin (CIP) and isoniazid. The drugs were shown to form complexes with sCX[8] using proton nuclear magnetic resonance, thermogravimetric analysis, fluorescence spectroscopy, and molecular modeling. Both drugs form 1:1 hydrated (H₂O: 13%-14% w/w) host-guest complexes, with sCX[8] binding around the pyridine ring of isoniazid, and around the piperazine and cyclopropane rings of CIP. From proton nuclear magnetic resonance, the binding constant of isoniazid to sCX[8] was 6.8 (±0.3) × 10³ M^?1. Addition of 2 equivalents of sCX[8] to CIP resulted in a 58% decrease in fluorescence, and time-resolved fluorescence anisotropy of CIP doubles with sCX[8]. Each drug binds into the cavity of the macrocycle, with binding stabilized via combinations of hydrogen bonding, electrostatic interactions, π-π stacking, and hydrophobic effects. The safety of sCX[8] was examined in vitro with human embryonic kidney 293 cells. The IC₅₀ of sCX[8] was 559 μM, which is a minimum of 5-fold higher than the concentration that would be used in the clinic. The in vitro effect of sCX[8] on the action of CIP was examined on a panel of bacterial lines. The results showed that sCX[8] has no inherent antibiotic activity and had no negative effect on the action of CIP.     

Dibucaine in Ionic-Gradient Liposomes: Biophysical,Toxicological, and Activity Characterization

Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of DBC.     

Effect of correcting for gestational age at birth on population prevalence of early childhood undernutrition

Background

Postmenstrual and/or gestational age-corrected age (CA) is required to apply child growth standards to children born preterm (< 37 weeks gestational age). Yet, CA is rarely used in epidemiologic studies in low- and middle-income countries (LMICs), which may bias population estimates of childhood undernutrition. To evaluate the effect of accounting for GA in the application of growth standards, we used GA-specific standards at birth (INTERGROWTH-21st newborn size standards) in conjunction with CA for preterm-born children in the application of World Health Organization Child Growth Standards postnatally (referred to as ‘CA’ strategy) versus postnatal age for all children, to estimate mean length-for-age (LAZ) and weight-for-age (WAZ) z scores at 0, 3, 12, 24, and 48-months of age in the 2004 Pelotas (Brazil) Birth Cohort.

Results

At birth (n = 4066), mean LAZ was higher and the prevalence of stunting (LAZ < ?2) was lower using CA versus postnatal age (mean ± SD): ? 0.36 ± 1.19 versus ? 0.67 ± 1.32; and 8.3 versus 11.6%, respectively. Odds ratio (OR) and population attributable risk (PAR) of stunting due to preterm birth were attenuated and changed inferences using CA versus postnatal age at birth [OR, 95% confidence interval (CI): 1.32 (95% CI 0.95, 1.82) vs 14.7 (95% CI 11.7, 18.4); PAR 3.1 vs 42.9%]; differences in inferences persisted at 3-months. At 12, 24, and 48-months, preterm birth was associated with stunting, but ORs/PARs remained attenuated using CA compared to postnatal age. Findings were similar for weight-for-age z scores.

Conclusions

Population-based epidemiologic studies in LMICs in which GA is unused or unavailable may overestimate the prevalence of early childhood undernutrition and inflate the fraction of undernutrition attributable to preterm birth.

     

Evaluation and learning in complex,rapidly changing health systems: China’s management of health sector reform

Healthcare systems are increasingly recognised as complex, in which a range of non-linear and emergent behaviours occur. China’s healthcare system is no exception. The hugeness of China, and the variation in conditions in different jurisdictions present very substantial challenges to reformers, and militate against adopting one-size-fits-all policy solutions. As a consequence, approaches to change management in China have frequently emphasised the importance of sub-national experimentation, innovation, and learning. Multiple mechanisms exist within the government structure to allow and encourage flexible implementation of policies, and tailoring of reforms to context. These limit the risk of large-scale policy failures and play a role in exploring new reform directions and potentially systemically-useful practices. They have helped in managing the huge transition that China has undergone from the 1970s onwards. China has historically made use of a number of mechanisms to encourage learning from innovative and emergent policy practices. Policy evaluation is increasingly becoming a tool used to probe emergent practices and inform iterative policy making/refining. This paper examines the case of a central policy research institute whose mandate includes evaluating reforms and providing feedback to the health ministry. Evaluation approaches being used are evolving as Chinese research agencies become increasingly professionalised, and in response to the increasing complexity of reforms. The paper argues that learning from widespread innovation and experimentation is challenging, but necessary for stewardship of large, and rapidly-changing systems.     

Health service utilization,unmet healthcare needs,and the potential of telemedicine services among Korean expatriates

Background

With the significant growth of migration and expatriation, facilitated by increased global mobility, the number of Koreans living abroad as of 2016 is approximately 7.4 million (15% of the Korean population). Healthcare utilization or health problems, especially among expatriates in developing countries, have not been well researched despite the various health risks these individuals are exposed to. Consequently, we identified the health utilization patterns and healthcare needs among Korean expatriates in Vietnam, Cambodia, and Uzbekistan.

Methods

This cross-sectional survey examined 429 Korean expatriates living in Vietnam (n?=?208), Cambodia (n?=?60), and Uzbekistan (n?=?161) who had access to the Internet and were living abroad for at least 6?months. A 67-item questionnaire was used, and feedback was received via an online survey program. Stepwise logistic regression analyses were performed to evaluate factors associated with unmet healthcare needs and preferences of certain type of telemedicine.

Results

We found that 45.5% (195/429) of respondents had used medical services in their country of stay. Among those who visited health institutions >?3 times, the most popular choice was general hospitals (39.4%, 15/38); however, they initially visited Korean doctors’ or local doctors’ offices. The most essential criteria for healthcare service facilities was a “skilled professional” (39.3%, 169/429), 42% wanted a health program for chronic disease management, and 30% wanted specialized internal medicine. A substantial number wanted to access telemedicine services and were willing to pay for this service. They were particularly interested in experts’ second opinion (61.5%, 264/429) and quick, 24-h medical consultations (60.8%, 261/429). Having unmet healthcare needs and being younger was strongly associated with all types of telemedicine networks.

Conclusions

Nearly half of the expatriates in developing countries had unmet healthcare needs. Telemedicine is one potential solution to meet these needs, especially in developing countries.

     

Ukrainian health care system and its chances for successful transition from Soviet legacies

Background

Ukraine, one of the largest states formed on the rubble of the Soviet Union, is widely perceived as a country that has lost its opportunities. Being devastated by corruption, it shows incapable to modernize and enter the economic path of sustainable growth. Similarly in the health care system no deeper reform efforts have been taken in the entire post-soviet period, leaving the system in bonds of ineffective solutions taken out of the Soviet era.

Main body

The recent geopolitical and economic crisis seem to favor the introduction of radical solutions that might lead to a rapid change in the organizational paradigm of the economic system, as well as in health care in Ukraine. In this paper we aim to highlight the key features of the ongoing health reform in Ukraine, identify basic challenges for it, and assess rationality and feasibility of the reform. We found that the projected scope and schedule of changes in the Ukrainian health system give promising prognosis regarding its final effect.

Conclusions

The final success of health reform in Ukraine is dependent on a number of factors, including the financial foundation arising of economic stability of the country, balance assurance between public and private spending for health and ability to eliminate the long-lasting practices, particularly when they are connected with activities of lobbying groups occupying particular positions in the health system. A consequence of actions taken by the political decision-makers in the longer perspective are also to highly determine the reform’s chances for success.

     

Exploring motivations behind pollution-mask use in a sample of young adults in urban China

Background

Wearing a pollution mask is an effective, practical, and economic way to prevent the inhalation of dangerous particulate matter (PM). However, it is not uncommon to observe negligence in adopting such behaviour, and this especially among young segments of the population. Using the Theory of Planned Behaviour (TPB) as conceptual framework, this study explores the role of socio-cognitive factors that affect the decision of wearing a pollution mask in the context of young educated people. This is done by selecting a sample of college students in urban China, a country that has seen air quality as one of the major challenges in the last decades. While young urban college students might be expected to be receptive to standard attempts to be influenced through reason-based cognitive stimuli, it is often found that this is not the case. The empirical analysis was articulated it in two steps. Structural Equation Modelling (SEM) was first used to examine the relationships among the conceptual constructs derived from the TPB conceptual model, and second Step-Wise Ordinary Least Squares Regressions (SWOLS) were employed to observe the partial effect played by each item on the decision to wear a mask.

Results

Results show that, while reason-based stimuli play a role, attitude, social norm, and self-efficacy were the most important predictors of the behavioural intention (p?<?0.01). The role of past behaviour was also acknowledged as strongly associated with the dependent variable (p?<?0.01). Overall, the likelihood of wearing a pollution mask increases with the importance of others socio-cognitive and psychological factors, which could help understand behavioural biases, and explain the relative role of several mechanisms behind the decision to wear a mask.

Conclusions

While tackling pollution requires multiple and synergic approaches, encouraging self-prevention using pollution mask is a simple and effective action, implementable at negligible costs. Resistance among younger, well-educated cohorts to wear masks can be overcome by stressing the social desirability of action and the sense of empowerment derived from its usage. This study has the potential to inform policies aimed at changing suboptimal behavioural attitudes by identifying triggers for change, and it could serve in improving the tailoring of health promotion messages aimed at nudging healthy behaviour.