"The Water in Which We Swim:" A Unique, Post-Clerkship Multidisciplinary Course.

OBJECTIVE: To improve patient outcomes and promote health equity, medical students must be taught not only biomedicine, but also the social sciences to understand the larger contexts in which patients live and health care operates. Yet, most undergraduate medical education does not explicitly cover these topics in a required, longitudinal curriculum. METHODS: In January 2015 at Harvard Medical School, we created a two-part sequence (pre- and post-clerkship) of required, 4-week multidisciplinary courses-"Essentials of the Profession I and II"-to fill this gap. "Essentials of the Profession II (EOP2)" is an advanced social sciences course anchored in patient narratives and the lived experiences of students and includes clinical epidemiology and population health, healthcare delivery and leadership, health policy, medical ethics and professionalism, and social medicine that engages students to conduct structural analyses to be effective healers, advocates, and leaders. RESULTS: Per student course evaluations, the overall course rating was 1.7 (SD 0.9, 1 = excellent and 5 = poor); its overall rating has improved over time; and it has scored well even when run virtually. It was rated highly in application of critical thinking, integration of the disciplines, and relevance for clinical work. Qualitative analyses of student responses revealed the following key course strengths: breadth of topics, teaching faculty and guest speakers, and small group discussions. The weaknesses included workload, lack of diversity of opinions, repetition, and time spent in lectures. CONCLUSIONS: We argue that EOP2 is "essential" for post-clerkship medical education. It offers an opportunity to re-ignite and enhance humanism and activism; remind students why they chose the medical profession; equip them with frameworks and toolkits to help them to overcome challenges; and devise solutions to improve health care and patient outcomes that are applicable to their future training and ongoing practice of medicine.

Actin-templated Structures: Nature's Way to Hierarchical Surface Patterns (Gecko's Setae as Case Study).

The hierarchical design of the toe pad surface in geckos and its reversible adhesiveness have inspired material scientists for many years. Micro- and nano-patterned surfaces with impressive adhesive performance have been developed to mimic gecko's properties. While the adhesive performance achieved in some examples has surpassed living counterparts, the durability of the fabricated surfaces is limited and the capability to self-renew and restore function-inherent to biological systems-is unimaginable. Here the morphogenesis of gecko setae using skin samples from the Bibron´s gecko (Chondrodactylus bibronii) is studied. Gecko setae develop as specialized apical differentiation structures at a distinct cell-cell layer interface within the skin epidermis. A primary role for F-actin and microtubules as templating structural elements is necessary for the development of setae's hierarchical morphology, and a stabilization role of keratins and corneus beta proteins is identified. Setae grow from single cells in a bottom layer protruding into four neighboring cells in the upper layer. The resulting multicellular junction can play a role during shedding by facilitating fracture of the cell-cell interface and release of the high aspect ratio setae. The results contribute to the understanding of setae regeneration and may inspire future concepts to bioengineer self-renewable patterned adhesive surfaces.

Cytocompatibility Evaluation of PEG-Methylsulfone Hydrogels.

Methylsulfone derivatized poly(ethylene) glycol (PEG) macromers can be biofunctionalized with thiolated ligands and cross-linked with thiol-based cross-linkers to obtain bioactive PEG hydrogels for in situ cell encapsulation. Methylsulfonyl-thiol (MS-SH) reactions present several advantages for this purpose when compared to other thiol-based cross-linking systems. They proceed with adequate and tunable kinetics for encapsulation, they reach a high conversion degree with good selectivity, and they generate stable reaction products. Our previous work demonstrated the cytocompatibility of cross-linked PEG-MS/thiol hydrogels in contact with fibroblasts. However, the cytocompatibility of the in situ MS-SH cross-linking reaction itself, which generates methylsulfinic acid as byproduct at the cross-linked site, remains to be evaluated. These studies are necessary to evaluate the potential of these systems for in vivo applications. Here we perform an extensive cytocompatibility study of PEG hydrogels during in situ cross-linking by the methylsulfonyl-thiol reaction. We compare these results with maleimide-thiol cross-linked PEGs which are well established for cell culture and in vivo experiments and do not involve the release of a byproduct. We show that fibroblasts and endothelial cells remain viable after in situ polymerization of methylsulfonyl-thiol gels on the top of the cell layers. Cell viability seems better than after in situ cross-linking hydrogels with maleimide-thiol chemistry. The endothelial cell proinflammatory phenotype is low and similar to the one obtained by the maleimide-thiol reaction. Finally, no activation of monocytes is observed. All in all, these results demonstrate that the methylsulfonyl-thiol chemistry is cytocompatible and does not trigger high pro-inflammatory responses in endothelial cells and monocytes. These results make methylsulfonyl-thiol chemistries eligible for in vivo testing and eventually clinical application in the future.

[The Lübeck Scale of Basic Mobility : Assessment of geriatric patients with severely impaired mobility]. / Die Lübecker Skala der Basis-Mobilität : Assessment schwer in ihrer Mobilität beeinträchtigter geriatrischer Patienten.

BACKGROUND: In the geriatric assessment of mobility, the timed up and go (TUG) test is often used; however, many inpatients are unable to master this test. The Lübeck Scale of Basic Mobility (LSBM) was developed as a performance test for this target group. OBJECTIVE: The study investigated the properties of the 7­task LSBM, which has a scaling at item level based on the 5­level assessment of impairments according to the ICF. MATERIAL AND METHODS: In 77 patients who had not mastered the TUG test at acute geriatric hospital admission, the LSBM was completed at intervals of 7-18 days (t0, t1), including one rating by 2 investigators. For convergent validity, the De Morton Mobility Index (DEMMI) was used. RESULTS: The LSBM score and DEMMI score were highly correlated (-0.880, p < 0.001). A floor effect did not occur with LSBM and occurred with DEMMI in 5 patients (6.5%). The predictive validity for predicting coping with TUG test at discharge based on the sum score at t0 was -0.577 for the LSBM, and 0.542 for the DEMMI (Spearman's correlation, p = 0.001). The interrater reliability of the LSBM was 0.983 (p < 0.001), the correlation between test and retest was 0.836 (p < 0.001) and the internal consistency via Cronbach's α was 0.876. The effect size as a measure of change sensitivity was Cohen's d 0.711. CONCLUSION: The LSBM facilitates treatment goal setting and allows standardized documentation of even small improvements and deteriorations in patients with reduced basic mobility.

Referral care for high-risk pregnant women in rural Rajasthan, India: a qualitative analysis of barriers and facilitators.

OBJECTIVE: To qualitatively assess the barriers and facilitators to uptake of referral services amongst high-risk pregnant women in rural Rajasthan. METHODS: A purposive sample of pregnant women with high-risk conditions requiring referral follow-up care (severe hypertension, moderate anemia, and severe anemia) were considered for inclusion. In-depth individual interviews were conducted in the local dialect, Mewari. Interviews were transcribed, coded, and organized for thematic generation as per the analytical framework described in the socio-ecological model. RESULTS: 19 high risk pregnant women of low socioeconomic backgrounds across 15 villages were interviewed. Barriers to referral care included lack of transportation, household responsibilities, and limited awareness, education, and social support. The most prominent barrier was lack of accompaniment to the referral center by a family member or health worker. Facilitators included available husbands, engaged heath workers, supportive neighbors, and other female family members who shared past experiences. CONCLUSIONS: Social support at the interpersonal and community level was key to overcoming referral care barriers faced by high-risk pregnant women in rural Rajasthan. Interventions that enhance social support may improve uptake of referral care services by high-risk pregnant women.

[Positioning the hand to act-Validation of the 8-point reaching range test]. / Die Hand positionieren, um zu agieren ­ Validierung des 8-Punkte-Greifraum-Tests.

BACKGROUND: The standardized geriatric assessment of the upper extremities is often limited to measurement of hand strength. The only other instrument mentioned in the S1 guidelines on level 2 geriatric assessment is the 20 cents test (20-C-T); however, in addition to strength and fine motor skills, successful hand placement is a prerequisite for self-care. OBJECTIVE: The 8­point reaching range test (8P-GRT) was developed for standardized separate testing of sides in a seated person concerning hand positioning relevant to daily living. The purpose of the study was to determine quality criteria of the 8P-GRT in geriatric hospital patients. MATERIAL AND METHODS: Between 31 July 2019 and 23 September 2019, a total of 82 inpatients were examined at the Hospital Red Cross Lübeck Geriatrics Center using the 8P-GRT, shoulder pain and disability index (SPADI), a questionnaire on self-care activities corresponding to the hand positions of the 8P-GRT, hand strength measurement and the 20-C­T. RESULTS: The interrater reliability was 0.99 and the retest reliability was 0.95 for the right side and 0.90 for the left side. On the individual level a ceiling effect (both sides score 8) occurred in 4.1% (n = 3) but no floor effect was observed. The internal consistency (Cronbach's alpha) of the two-factorial test according to factor analysis was 0.78 (right) and 0.76 (left). Each of the other tests correlated more closely with the 8P-GRT on the right side, whereby the correlation was highest with the abovenamed questionnaire (-0.72), followed by the SPADI (-0.60). CONCLUSION: A standardized survey of hand strength, fine motor skills and active positioning of the hand (e.g., 8P-GRT) synthesizes the main aspects of upper extremity functioning into an overall picture.

[Self-assessment of daily activities using the Duruöz Hand Index-Validation of the German translation]. / Selbstbeurteilung von Alltagsaktivitäten mittels Duruöz-Hand-Index ­ Validierung der deutschen Übersetzung.

BACKGROUND: Independence in activities of daily living depends to a large extent on the upper extremities; however, the instruments widely used in geriatrics to assess self-care abilities do not allow a focus on this body region. In order to map the fluctuating course of hand function-dependent daily living skills with a self-assessment instrument, rheumatologists have developed the Duruöz Hand Index (DHI). OBJECTIVE: The German translation authorized by Duruöz was tested for its applicability in the assessment of geriatric outpatient and day hospital patients and test quality criteria were determined. MATERIAL AND METHODS: Study participants completed the DHI three times. A postgraduate student blinded to the results performed an anamnesis and examination. The geriatric team made an inter-professional assessment of hand function-related daily living skills twice with at least 2­week intervals. RESULTS: Data collection was performed from 16 November 2016 to 27 April 2017 on 101 geriatric day hospital or outpatient patients. Retest reliability was high (0.937), as was internal consistency (Cronbach's α 0.949). Difficulty with activities of daily living correlated more closely with joint mobility (Keitel Index) and fine motor skills (20 cents test) than with hand strength. CONCLUSION: The DHI provides a survey of difficulties with activities of daily living that is focused on the upper extremities. Because about one in three patients required assistance (answering follow-up questions, reading aloud) despite the exclusion of patients with more severely impaired cognition and vision, the examiner should remain present.

The Women Before Me: My Journey Painting Honor Wall Portraits of Women Physicians.

In this article, the authors briefly review the history and status of institutional honor wall portraits at medical schools, and they highlight the implications of a lack of diversity in these portraits for current medical students and the academic medicine pipeline. The authors then describe how contemporary portrait artists have used art as a tool for advocacy. They detail the first author's empowering and intimate journey as a medical student as she identified, connected with, and painted a portrait gallery of some of her medical school's prominent alumnae of color. This unique effort highlighted the unsung accomplishments of these women physicians and served to combat the visual disparity in honor wall portraits on campus. The authors also outline the common barriers faced by the portrait subjects and the key validation they offered the first author, a fellow woman of color. The authors describe the historical and psychological significance of several artistic decisions made for these portraits in weighing the intersections of race, gender, and profession. They then emphasize the reciprocal nature of oil portraiture and how, through painting these women, the first author was able to better envision her community of mentors, deepen her commitment to diversity and inclusion, and strengthen her own career aspirations. These portraits will hang in the student center of Harvard Medical School and will serve as a lasting reminder to future trainees, especially women and people of color, that they belong in the halls of medicine.

A Longitudinal Case-Based Global Health Curriculum for the Medical Student Clerkship Year.

Introduction: Over 20% of U.S. medical students express interest in global health (GH) and are searching for opportunities within the field. In addition, domestic practice increasingly requires an understanding of the social factors affecting patients' health. Unfortunately, only 39% of medical schools offer formal GH education, and there is a need to incorporate more GH into medical school curricula. Methods: We designed a longitudinal case-based curriculum for the core clerkships. We conducted an institution-wide survey to determine baseline GH interest and developed three case-based sessions to incorporate into medicine, surgery, and pediatrics clerkships. The cases included clinical learning while exploring fundamental GH concepts. Cases were developed with GH faculty, and the pilot was implemented from October to December 2019 with 55 students. We used pre- and postdidactic surveys to assess interest in GH and elicit qualitative feedback. A follow-up survey assessed students' identification of barriers faced by their patients domestically. Results: Students felt that clinical management, physical exam skills, epidemiology, and social determinants of health were strengths of the sessions and that they were able to apply more critical thinking skills and cultural humility to their patients afterwards. Students felt that simulation would be a great addition to the curriculum and wanted both more time per session and more sessions overall. Discussion: Integrating GH didactics into the core clerkships has potential to address gaps in GH education and to help students make connections between clinical learning and GH, enhancing their care of patients both domestically and in future GH work.

Professional language use by alumni of the Harvard Medical School Medical Language Program.

BACKGROUND: Despite the growing number of patients with limited English proficiency in the United States, not all medical schools offer medical language courses to train future physicians in practicing language-concordant care. Little is known about the long-term use of non-English languages among physicians who took language courses in medical school. We conducted a cross-sectional study to characterize the professional language use of Harvard Medical School (HMS) alumni who took a medical language course at HMS and identify opportunities to improve the HMS Medical Language Program. METHODS: Between October and November 2019, we sent an electronic survey to 803 HMS alumni who took a medical language course at HMS between 1991 and 2019 and collected responses. The survey had questions about the language courses and language use in the professional setting. We analyzed the data using descriptive statistics and McNemar's test for comparing proportions with paired data. The study was determined not to constitute human subjects research. RESULTS: The response rate was 26% (206/803). More than half of respondents (n = 118, 57%) cited their desire to use the language in their future careers as the motivation for taking the language courses. Twenty-eight (14%) respondents indicated a change from not proficient before taking the course to proficient at the time of survey whereas only one (0.5%) respondent changed from proficient to not proficient (McNemar's p-value < 0.0001). Respondents (n = 113, 56%) reported that clinical electives abroad influenced their cultural understanding of the local in-country population and their language proficiency. Only 13% (n = 27) of respondents have worked in a setting that required formal assessments of non-English language proficiency. CONCLUSIONS: HMS alumni of the Medical Language Program reported improved language proficiency after the medical language courses' conclusion, suggesting that the courses may catalyze long-term language learning. We found that a majority of respondents reported that the medical language courses influenced their desire to work with individuals who spoke the language of the courses they took. Medical language courses may equip physicians to practice language-concordant care in their careers.

Perspectives and Solutions from Clinical Trainees and Mentors Regarding Ethical Challenges During Global Health Experiences.

Background: Clinical trainees face challenges throughout short-term experiences in global health (STEGH) that are not routinely addressed. Objectives: Describe common professional and ethical dilemmas faced by clinical trainees and identify gaps and solutions for pre, during, and post-STEGH training and mentoring. Methods: We conducted a mixed-methods study among trainees and mentors involved in global health. The study utilized focus groups with trainees (November-December 2015) and online surveys of trainees, in-country and stateside faculty mentors (October 2016-April 2017). Results: 85% (17/20) of students reported feeling prepared for their STEGH; however, 59% (23/39) of faculty felt students were unprepared. A majority of both students (90%) and faculty (77%) stated students would likely experience an ethical dilemma during STEGH. Major themes relating to meaningful global health work were elucidated: personal and inter-professional skills; interpersonal networks and collaboration; and awareness of power dynamics and bias. Conclusions: The most common challenges faced by trainees during STEGH related to leadership, bias, ethics and interprofessional collaboration. Redirecting trainee energies from a focus on 'doing' and deliverables to attitudes (e.g., humility, professionalism) that cultivate personal and professional growth will help create lifelong global health learners and leaders.

Value-Based Health Care in Undergraduate Medical Education.

PROBLEM: Value-based health care (VBHC) is an innovative framework for redesigning care delivery to achieve better outcomes for patients and reduce cost; however, providing students with the skills to understand and engage with these topics is a challenge to medical educators. APPROACH: Here, the authors present a novel, VBHC curriculum integrated into a required course for post-core clerkship students-launched in 2018 at Harvard Medical School and taught in conjunction with Harvard Business School faculty-that highlights key principles of VBHC most relevant to undergraduate medical education. The course integrates VBHC with related health disciplines, including health policy, ethics, epidemiology, and social medicine, using a case-based method. Students practice active decision making while learning key concepts to address value in clinical practice. OUTCOMES: Since the course's inception in March 2018, 95 students (87%) completed the standardized course evaluation; the majority said VBHC content and pedagogical style (i.e., case-based learning) enhanced their learning. Students' critiques focused on too little integration with other disciplines (e.g., social medicine, ethics), the physical space, and inadequate time for debates about potential tensions between VBHC and other course disciplines. NEXT STEPS: The authors believe that by exposing medical students to the principles of VBHC, students will fulfill the expectations of graduating physicians by excelling as critical thinkers, collaborative team members, and judicious care providers throughout their residency, clinical practice, and beyond. Future VBHC curricula expansions may include elective coursework, intensive seminar series, and formal dual degrees.

The power of language-concordant care: a call to action for medical schools.

We live in a world of incredible linguistic diversity; nearly 7000 languages are spoken globally and at least 350 are spoken in the United States. Language-concordant care enhances trust between patients and physicians, optimizes health outcomes, and advances health equity for diverse populations. However, historical and contemporary trauma have impaired trust between communities of color, including immigrants with limited English proficiency, and physicians in the U.S. Threats to informed consent among patients with limited English proficiency persist today. Language concordance has been shown to improve care and serves as a window to broader social determinants of health that disproportionately yield worse health outcomes among patients with limited English proficiency. Language concordance is also relevant for medical students engaged in health care around the world. Global health experiences among medical and dental students have quadrupled in the last 30 years. Yet, language proficiency and skills to address cultural aspects of clinical care, research and education are lacking in pre-departure trainings. We call on medical schools to increase opportunities for medical language courses and integrate them into the curriculum with evidence-based teaching strategies, content about health equity, and standardized language assessments. The languages offered should reflect the needs of the patient population both where the medical school is located and where the school is engaged globally. Key content areas should include how to conduct a history and physical exam; relevant health inequities that commonly affect patients who speak different languages; cultural sensitivity and humility, particularly around beliefs and practices that affect health and wellbeing; and how to work in language-discordant encounters with interpreters and other modalities. Rigorous language assessment is necessary to ensure equity in communication before allowing students or physicians to use their language skills in clinical encounters. Lastly, global health activities in medical schools should assess for language needs and competency prior to departure. By professionalizing language competency in medical schools, we can improve patients' trust in individual physicians and the profession as a whole; improve patient safety and health outcomes; and advance health equity for those we care for and collaborate with in the U.S. and around the world.

In Vitro Entero-Capillary Barrier Exhibits Altered Inflammatory and Exosomal Communication Pattern after Exposure to Silica Nanoparticles.

The intestinal microvasculature (iMV) plays multiple pathogenic roles during chronic inflammatory bowel disease (IBD). The iMV acts as a second line of defense and is, among other factors, crucial for the innate immunity in the gut. It is also the therapeutic location in IBD targeting aggravated leukocyte adhesion processes involving ICAM-1 and E-selectin. Specific targeting is stressed via nanoparticulate drug vehicles. Evaluating the iMV in enterocyte barrier models in vitro could shed light on inflammation and barrier-integrity processes during IBD. Therefore, we generated a barrier model by combining the enterocyte cell line Caco-2 with the microvascular endothelial cell line ISO-HAS-1 on opposite sides of a transwell filter-membrane under culture conditions which mimicked the physiological and inflamed conditions of IBD. The IBD model achieved a significant barrier-disruption, demonstrated via transepithelial-electrical resistance (TER), permeability-coefficient (Papp) and increase of sICAM sE-selectin and IL-8. In addition, the impact of a prospective model drug-vehicle (silica nanoparticles, aSNP) on ongoing inflammation was examined. A decrease of sICAM/sE-selectin was observed after aSNP-exposure to the inflamed endothelium. These findings correlated with a decreased secretion of ICAM/E-selectin bearing exosomes/microvesicles, as evaluated via ELISA. Our findings indicate that aSNP treatment of the inflamed endothelium during IBD may hamper exosomal/microvesicular systemic communication.

[The "Lübeck Worlds of Movement Model"-results of the effects evaluation]. / Das "Lübecker Modell Bewegungswelten" ­ Ergebnisse der Effektevaluation.

BACKGROUND: There are few standardized and evaluated intervention programs for elderly people in need of care that consider motor, cognitive and social aspects. Therefore, the "Lübeck Worlds of Movement Model" was developed by the Lübeck Geriatrics Research Group as a multidimensional standardized intervention program for continuous use in the nursing home. OBJECTIVES: The model was evaluated for its effects over the course of one year in the areas of self-care competence (primary endpoint), mobility, coordination, flexibility, strength, endurance, and cognition. The results are presented in this article. MATERIALS AND METHODS: The sample recruitment took place in 6 nursing homes in Kiel (control group) and 10 in Lübeck (intervention group). Care-dependent senior citizens from the neighborhood were also allowed to participate. Inclusion criteria were the ability to walk at least 6 m independently and the cognitive and sensory capacities to follow the group training. The evaluation study had 255 subjects. To verify the effects of the intervention, various tests were performed at baseline and after 3, 6, 9, and 12 months: Barthel Index, Timed Up and Go, 4­meter walk test, Romberg stand, one-leg stand, 20-Cents Test, 8­Point Reach Test, hand force, 5­Chair-Rise Test, 2­Minute Step Test, and Six-Item Screener. RESULTS: Comparison of the control group with the subjects who had participated in at least half of the training sessions (per-protocol analysis) showed the highest effect size in the multivariate analysis of variance after one year for the Barthel index, followed by the Timed Up and Go, cumulated over all times for the Romberg stand and 5­Chair-Rise Test. The maximum effect measured over the entire assessment occurred after 6 months (partial eta square ηp2 = 0.332). CONCLUSIONS: The model developed preventive effects on all investigated dimensions over the course of a year, but with differences in intensity and time of maximum effect. The motivation for long-term participation was high.

Human Co- and Triple-Culture Model of the Alveolar-Capillary Barrier on a Basement Membrane Mimic.

The development of an in vitro model resembling the alveolar-capillary barrier might be a highly beneficial tool to study lung physiology as well as the immune response of the lung to infection or after exposure to nanoparticles. This study is based on an in vitro alveolar barrier developed on a basement membrane mimic, composed of ultrathin nanofiber meshes generated via electrospinning using bioresorbable poly(ɛ-caprolactone). As cellular components, NCI H441, resembling the alveolar epithelial cells, and ISO-HAS-1, an endothelial cell line, were used to perform bipolar coculture experiments for a total cultivation period of 14 days. In addition to immunohistochemical and immunofluorescent studies, transepithelial electrical resistance (TER) and transport capabilities of the in vitro model system were investigated. Alveolar barrier function could be clearly determined for the postulated bipolar coculture system on the basement membrane mimic, since TER increased during the course of bipolar cultivation. Furthermore, to gain first insights into possible lung inflammatory reactions in vitro, this coculture model was further expanded by a human leukemia monocyte cell line (THP-1). This triple-culture system was able to maintain adequately the barrier properties of the bipolar coculture, thus making this in vitro model consisting of epithelial, endothelial, and immune cells on a basement membrane mimic a promising basis for further studies in tissue engineering.

Human CD8+ T Cells Damage Noninfected Epithelial Cells during Influenza Virus Infection In Vitro.

During severe influenza A virus (IAV) infections, a large amount of damage to the pulmonary epithelium is the result of the antiviral immune response. Specifically, whilst CD8+ T cells are important for killing IAV-infected cells, during a severe IAV infection, they can damage uninfected epithelial cells. At present, the mechanisms by which this occurs are unclear. Here, we used a novel in vitro coculture model of human NCl-H441 cells and CD8+ T cells to provide a new insight into how CD8+ T cells may affect uninfected epithelial cells during severe IAV infections. Using this model, we show that human IAV-specific CD8+ T cells produce soluble factors that reduce the barrier integrity of noninfected epithelial cells (referred to as "bystander damage"). We show that this bystander damage is the result of a combination of TNF-α and IFN-γ. This bystander damage occurred in the absence of widespread epithelial cell death and was instead associated with decreased expression of epithelial cell ion channels and pumps. Together, these data suggest that ameliorating the function of epithelial cell ion channels and pumps may help reduce immunopathology during severe IAV infections.

A responsive human triple-culture model of the air-blood barrier: incorporation of different macrophage phenotypes.

Current pulmonary research underlines the relevance of the alveolar macrophage (AM) integrated in multicellular co-culture-systems of the respiratory tract to unravel, for example, the mechanisms of tissue regeneration. AMs demonstrate a specific functionality, as they inhabit a unique microenvironment with high oxygen levels and exposure to external hazards. Healthy AMs display an anti-inflammatory phenotype, prevent hypersensitivity to normally innocuous contaminants and maintain tissue homeostasis in the alveolus. To mirror the actual physiological function of the AM, we developed three different polarized [classically activated (M1) and alternatively activated (M2wh , wound-healing; M2reg , regulatory)] macrophage models using a mixture of differentiation mediators, as described in the current literature. To test their immunological impact, these distinct macrophage phenotypes were seeded on to the epithelial layer of an established in vitro air-blood barrier co-culture, consisting of alveolar epithelial cells A549 or H441 and microvascular endothelial cells ISO-HAS-1 on the opposite side of a Transwell filter-membrane. IL-8 and sICAM release were measured as functionality parameters after LPS challenge. The M1 model itself already provoked a severe inflammatory-like response of the air-blood barrier co-culture, thus demonstrating its potential as a useful in vitro model for inflammatory lung diseases. The two M2 models represent a 'non-inflammatory' phenotype but still showed the ability to trigger inflammation following LPS challenge. Hence, the latter could be used to establish a quiescent, physiological in vitro air-blood model. Thus, the more complex differentiation protocol developed in the present study provides a responsive in vitro triple-culture model of the air-blood-barrier that mimics AM features as they occur in vivo. © 2015 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.

The role of the intestinal microvasculature in inflammatory bowel disease: studies with a modified Caco-2 model including endothelial cells resembling the intestinal barrier in vitro.

The microvascular endothelium of the gut barrier plays a crucial role during inflammation in inflammatory bowel disease. We have modified a commonly used intestinal cell model based on the Caco-2 cells by adding microvascular endothelial cells (ISO-HAS-1). Transwell filters were used with intestinal barrier-forming Caco-2 cells on top and the ISO-HAS-1 on the bottom of the filter. The goal was to determine whether this coculture mimics the in vivo situation more closely, and whether the model is suitable to evaluate interactions of, for example, prospective nanosized drug vehicles or contrast agents with this coculture in a physiological and inflamed state as it would occur in inflammatory bowel disease. We monitored the inflammatory responsiveness of the cells (release of IL-8, soluble intercellular adhesion molecule 1, and soluble E-selectin) after exposure to inflammatory stimuli (lipopolysaccharide, TNF-α, INF-γ, IL1-ß) and a nanoparticle (Ba/Gd: coprecipitated BaSO4 and Gd(OH)3), generally used as contrast agents. The barrier integrity of the coculture was evaluated via the determination of transepithelial electrical resistance and the apparent permeability coefficient (Papp) of NaFITC. The behavior of the coculture Caco-1/ISO-HAS-1 was compared to the respective monocultures Caco-2 and ISO-HAS-1. Based on transepithelial electrical resistance, the epithelial barrier integrity of the coculture remained stable during incubation with all stimuli, whereas the Papp decreased after exposure to the cytokine mixture (TNF-α, INF-γ, IL1-ß, and Ba/Gd). Both the endothelial and epithelial monocultures showed a high inflammatory response in both the upper and lower transwell-compartments. However, in the coculture, inflammatory mediators were only detected on the epithelial side and not on the endothelial side. Thus in the coculture, based on the Papp, the epithelial barrier appears to prevent a potential inflammatory overreaction in the underlying endothelial cells. In summary, this coculture model exhibits in vivo-like features, which cannot be observed in conventional monocultures, making the former more suitable to study interactions with external stimuli.