Trade-offs between acquired and innate immune defenses in humans

Immune defenses provide resistance against infectious disease that is critical to survival. But immune defenses are costly, and limited resources allocated to immunity are not available for other physiological or developmental processes. We propose a framework for explaining variation in patterns of investment in two important subsystems of anti-pathogen defense: innate (non-specific) and acquired (specific) immunity. The developmental costs of acquired immunity are high, but the costs of maintenance and activation are relatively low. Innate immunity imposes lower upfront developmental costs, but higher operating costs. Innate defenses are mobilized quickly and are effective against novel pathogens. Acquired responses are less effective against novel exposures, but more effective against secondary exposures due to immunological memory. Based on their distinct profiles of costs and effectiveness, we propose that the balance of investment in innate versus acquired immunity is variable, and that this balance is optimized in response to local ecological conditions early in development. Nutritional abundance, high pathogen exposure and low signals of extrinsic mortality risk during sensitive periods of immune development should all favor relatively higher levels of investment in acquired immunity. Undernutrition, low pathogen exposure, and high mortality risk should favor innate immune defenses. The hypothesis provides a framework for organizing prior empirical research on the impact of developmental environments on innate and acquired immunity, and suggests promising directions for future research in human ecological immunology.     

The Role of Psychological Sense of School Membership and Postcode as Predictors of Profiles of Socio-emotional Health in Primary School Children in England

School Mental Health - A dual approach to mental health in schools has been widely defended, where the assessment of psychological distress and the examination of strengths/well-being are two...     

Five Years of MBSAQIP Data: Characteristics,Outcomes, and Trends for Patients with Super-obesity

Purpose

Incidence of super obesity (SO; BMI ≥ 50 kg/m²) is growing rapidly and confers worse metabolic complications than non-SO (BMI 30–50 kg/m²). We aim to characterize bariatric surgery patients with SO, their postoperative complications, and treatment trends over the last 5 years in hopes of informing SO-specific treatment protocols.

Materials and Methods

The MBSAQIP database was analyzed, and two cohorts were compared, those with SO and non-SO. Univariate analysis was performed to determine between-group differences. Multivariable logistic regression analysis was performed to determine if SO was independently associated with serious complications or mortality.

Results

We evaluated 751,952 patients with 173,110 (23.0%) having SO. Patients with SO were younger (42.2 ± 11.8 SO vs 45.1 ± 12.0 years non-SO, p < 0.001) and less likely to be female (74.8% vs 81.1%, p < 0.001). While comorbidities seem to be decreasing overall in bariatric surgery patients, those with SO have worse functional capacity and more endocrine, pulmonary, and vascular comorbidities. Patients with SO also have worse 30-day postoperative complications, and SO was independently associated with severe complications (OR 1.08; CI 1.05–1.11, p < 0.001) and mortality (OR 2.49; CI 2.12–2.92, p < 0.001)

Conclusions

Patients with SO have significantly increased preoperative comorbidities resulting in worse postoperative outcomes. SO remains an independent risk factor for serious complications and the greatest independent risk factor for 30-day postoperative mortality. Considering the expected increase in patients with SO, substantial work is required to optimize bariatric surgery strategies specific to these patients.

Graphical abstract

     

Mind the gap: Teachers’ conceptions of student-staff partnership and its potential to enhance educational quality

Abstract

Introduction: Student-staff partnerships as a concept to improve medical education have received a growing amount of attention. Such partnerships are collaborations in which students and teachers seek to improve education by each adding their unique contribution to decision-making and implementation processes. Although previous research has demonstrated that students are favourable to this concept, teachers remain hesitant. The present study investigated teachers’ conceptions of student-staff partnerships and of the prerequisites that are necessary to render such partnerships successful and enhance educational quality.

Method: We conducted semi-structured interviews with 14 course coordinators who lead course design teams and also teach in 4 bachelor health programmes, using Bovill and Bulley’s levels of student participation as sensitising concepts during data analysis.

Results: The results pointed to three different conceptions of student-staff partnerships existing among teachers: Teachers teach and students study; teachers teach and value students’ feedback; and teachers and students co-create. The prerequisites for effective co-creation teachers identified were: Teachers must be open to involve students and create dialogues; students must be motivated and have good communication skills; the organisation must be supportive; and teachers should have the final say.

Conclusion: We conclude that teachers’ conceptions are consistent with Bovill and Bulley’s levels of student participation. Under certain conditions, teachers are willing to co-create and reach the highest levels of student participation.     

Beyond homogenization discourse: Reconsidering the cultural consequences of globalized medical education

Introduction: Global medical education standards, largely designed in the West, have been promoted across national boundaries with limited regard for cultural differences. This review aims to identify discourses on cultural globalization in medical education literature from non-Western countries.

Methods: To explore the diversity of discourses related to globalization and culture in the field of medical education, the authors conducted a critical review of medical education research from non-Western countries published in Academic Medicine, Medical Education and Medical Teacher from 2006 to 2014. Key discourses about globalization and culture emerged from a preliminary analysis of this body of literature. A secondary analysis identified inductive sub-themes.

Results: Homogenization, polarization and hybridization emerged as key themes in the literature. These findings demonstrate the existence of discourses beyond Western-led homogenization and the co-existence of globalization discourses ranging from homogenization to syncretism to resistance.

Conclusions: This review calls attention to the existence of manifold discourses about globalization and culture in non-Western medical education contexts. In refocusing global medical education processes to avoid Western cultural imperialism, it will also be necessary to avoid the pitfalls of other globalization discourses. Moving beyond existing discourses, researchers and educators should work towards equitable, context-sensitive and locally-driven approaches to global medical education.     

Comparison of respiratory inductive plethysmography versus head-out plethysmography for anesthetized nonhuman primates in an animal biosafety level 4 facility

For inhalational studies and aerosol exposures to viruses, head-out plethysmography acquisition has been traditionally used for the determination of estimated inhaled dose in anesthetized nonhuman primates prior to or during an aerosol exposure. A pressure drop across a pneumotachograph is measured within a sealed chamber during inspiration/exhalation of the nonhuman primate, generating respiratory values and breathing frequencies. Due to the fluctuation of depth of anesthesia, pre-exposure respiratory values can be variable, leading to less precise and accurate dosing calculations downstream. Although an anesthesia infusion pump may help stabilize the depth of sedation, pumps are difficult to use within a sealed head-out plethysmography chamber. Real-time, head-out plethysmography acquisition could increase precision and accuracy of the measurements, but the bulky equipment needed for head-out plethysmography precludes real-time use inside a Class III biological safety cabinet, where most aerosol exposures occur. However, the respiratory inductive plethysmography (RIP) acquisition method measures the same respiratory parameters by detecting movement of the chest and abdomen during breathing using two elastic bands within the Class III biological safety cabinet. As respiratory values are relayed to a computer for software integration and analysis real-time, adjustment of aerosol exposure duration is based on the depth of sedation of the animal. The objective of this study was to compare values obtained using two methodologies (pre-exposure head-out plethysmography and real-time RIP). Transitioning to RIP technology with real-time acquisition provides more consistent, precise, and accurate aerosol dosing by reducing reported errors in respiratory values from anesthesia variability when using pre-exposure head-out plethysmography acquisition.