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Abstract Synthetic cell exoskeletons created from abiotic materials have attracted interest in materials science and biotechnology, as they can regulate cell behavior and create new functionalities. Here, a facile strategy is reported to mimic microalgal sporulation with on‐demand germination and locomotion via responsive metal–phenolic networks (MPNs). Specifically, MPNs with tunable thickness and composition are deposited on the surface of microalgae cells via one‐step coordination, without any loss of cell viability or intrinsic cell photosynthetic properties. The MPN coating keeps the cells in a dormant state, but can be disassembled on‐demand in response to environmental pH or chemical stimulus, thereby reviving the microalgae within 1 min. Moreover, the artificial sporulation of microalgae resulted in resistance to environmental stresses (e.g., metal ions and antibiotics) akin to the function of natural sporulation. This strategy can regulate the life cycle of complex cells, providing a synthetic strategy for designing hybrid microorganisms.

New materials for combating bacteria-caused infection and promoting the formation of microvascular networks during wound healing are of vital importance. Although antibiotics can be used to prevent infection, treatments that can disinfect and accelerate wound healing are scarce. Herein, we engineer a coating that is both highly compatible with current wound dressing substrates and capable of simultaneously disinfecting and revascularizing wounds using a metal-phenolic nanoplatform containing an alloyed nanostructured architecture (Ag@Cu-MPNNC). The alloyed nanostructure is formed by the spontaneous co-reduction and catalytic disproportionation reaction of multiple metal ions on a foundation metal-phenolic supramolecular layer. This synergistic presence of metals greatly improves the antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria, while demonstrating negligible cytotoxicity to normal tissue. In infected rat models, the Ag@Cu-MPNNC could kill bacteria efficiently, promoting revascularization and accelerate wound closure with no adverse side effects in infected in vivo models. In other words, this material acts as a combination therapy by inhibiting bacterial invasion and modulating bio-nano interactions in the wound.

Realizing robust underwater adhesion is challenging because a hydration layer impedes the interaction between substrates and adhesives. Here, the authors report a class of ultrastrong underwater adhesives with molecular non-canonical phenolic groups in a polymer to realize strong adhesion on various substrates.

Abstract The development of antimicrobial fabrics and textiles that can sustainably inhibit a broad spectrum of microbes is crucial for protecting against pathogens in various environments. However, engineering antimicrobial textiles is challenging due to issues with discoloration and inhibited breathability, the use of harmful or harsh reagents and synthesis conditions, and complex and/or time-consuming processing. Herein, we develop a facile and rapid approach to deposit antimicrobial coatings using universally adherent plant polyphenols and antimicrobial silver ions. Importantly, the coatings are colorless, thin (

Abstract Antibody‐nanoparticle conjugates are promising candidates for precision medicine. However, developing a controllable method for conjugating antibodies to nanoparticles without compromising the antibody activity represents a critical challenge. Here, a facile and generalizable film‐coating method is presented using zeolitic imidazole framework‐8 (ZIF‐8) to immobilize antibodies on various nanoparticles in a favorable orientation for enhanced cell targeting. Different model and therapeutic antibodies (e.g., Herceptin) are assembled on nanoparticles via a biomineralized film‐coating method and exhibited high antibody loading and targeting efficiencies. Importantly, the antibodies selectively bind to ZIF‐8 via their Fc regions, which favorably exposes the functional Fab regions to the biological target, thus improving the cell targeting ability of antibody‐coated nanoparticles. In combination, molecular dynamics simulations and experimental studies on antibody immobilization, orientation efficiency, and biofunctionality collectively demonstrate that this versatile site‐specific antibody conjugation method provides effective control over antibody orientation and leads to improved cell targeting for a variety of nanoparticles.

Monodisperse colloidal particles with tunable properties show promise for biomedical, energy, and environmental applications and simple routes for fabricating these particles are of interest. Here, the authors report a facile strategy for fabrication of diverse particles based on the supramolecular assembly of phenols and self-polymerizable thiols

Abstract Fluorinated motifs are promising for the engineering of repellent coatings, however, a fundamental understanding of how to effectively bind these motifs to various substrates is required to improve their stability in different use scenarios. Herein, the binding of fluorinated polyhedral oligomeric silsesquioxanes (POSS) using a cyanoacrylate glue (binder) is computationally and experimentally evaluated. The composite POSS–binder coatings display ultralow surface energy (≈10 mJ m−2), while still having large surface adhesions to substrates (300–400 nN), highlighting that super‐repellent coatings (contact angles >150°) can be readily generated with this composite approach. Importantly, the coatings show super‐repellency to both corrosive liquids (e.g., 98 wt% H2SO4) and ultralow surface tension liquids (e.g., alcohols), with ultralow roll‐off angles (

The growth of oriented crystalline metal–organic frameworks is desirable to exploit their surface area and porosity, but has proven difficult. Here the authors fabricate highly-oriented and simultaneously activated free-standing MOFs by an acoustically driven microcentrifugation platform.

Abstract Droplet bouncing on repellent solid surfaces (e.g., the lotus leaf effect) is a common phenomenon that has aroused interest in various fields. However, the scenario of a droplet bouncing off another droplet (either identical or distinct chemical composition) while moving on a solid material (i.e., ricocheting droplets, droplet billiards) is scarcely investigated, despite it having fundamental implications in applications including self‐cleaning, fluid transport, and heat and mass transfer. Here, the dynamics of bouncing collisions between liquid droplets are investigated using a friction‐free platform that ensures ultrahigh locomotion for a wide range of probing liquids. A general prediction on bouncing droplet–droplet contact time is elucidated and bouncing droplet–droplet collision is demonstrated to be an extreme case of droplet bouncing on surfaces. Moreover, the maximum deformation and contact time are highly dependent on the position where the collision occurs (i.e., head‐on or off‐center collisions), which can now be predicted using parameters (i.e., effective velocity, effective diameter) through the concept of an effective interaction region. The results have potential applications in fields ranging from microfluidics to repellent coatings.

The quantity of programmed cell death-ligand 1 (PD-L1) is regarded as a predicting factor of clinical response to anti-PD-1 axis immunotherapy. However, the expression of PD-L1 and its prognostic value in hepatocellular carcinoma (HCC) patients remain debated. Meanwhile, the molecular features of PD-1's other ligand, namely PD-L2, as well as its correlation with clinicopathological parameters and HCC tumor microenvironment (TME), are still poorly understood. In this study, immunohistochemistry (IHC) data from 304 HCC patients were used to determine the clinicopathological features of PD-L1 and PD-L2 and their correlation with CD8+ T cells in HCC. Moreover, fresh clinical HCC samples were used to identify the immune cell subtypes expressing PD-L1 and PD-L2. By using The Cancer Genome Atlas (TCGA) dataset, we further assessed the correlation between mutation signature, copy number variation (CNV), number of neoepitopes, immune gene expression, immune/stromal cell infiltration to the expression of PD-L1 and PD-L2. While membrane expression of PD-L2 was observed in 19.1% of tumor samples, no obvious expression of PD-L1 was detected on tumor cell membranes. High expression of PD-L2 on tumor membranes and PD-L1 in immune stroma were both significantly associated with poorer overall survival (OS) and disease-free survival (DFS) outcomes. Flow cytometry analysis and immunofluorescence showed that macrophages were the main immune cell subtype expressing both PD-L1 and PD-L2. Moreover, positive expression of PD-Ls was correlated with higher CD8+ T cells infiltration in immune stroma. CNV analysis showed a similarity between PD-L1 and PD-L2 in affecting gene expression. In addition, higher levels of PD-Ls correlated with higher expression of immune related genes, enhanced cytolytic activity, and larger proportions of immune/stromal cell infiltration. Collectively, our study reveals the impact of both PD-L1 and PD-L2 on the HCC tumor microenvironment for the first time, providing insight for new therapeutic options.

It is imperative to preserve the integrity of the gastrointestinal system in spite of the persistent existence of harmful chemicals and microbial flora in the gut. This is made possible by essential healing initiators called Trefoil factors which helps in mucosal reconstitution and tissue development on the gastrointestinal surface. The trefoil factors are a class of abundant secreted proteins that are essential for epithelial continuity (TFFs). Trefoil factor family (TFF) proteins are biologically active peptides that play significant role in safeguarding, restoring and continuity of the gastrointestinal tract (GIT) epithelium, through collaborative modulations with mucins in the mucosal layer. These peptides are readily produced in reaction to epithelial damage in the digestive tract, thereby contributing to the healing and restituting of the epithelial layers of the intestine. In addition, considerable evidence indicated that TFF peptides trigger proliferation, migration and angiogenesis, all which are crucial processes for wound healing. There is also increasing evidence that TFF peptides modulate the mucosal immune system. These protective properties, suggest that dietary manipulation strategies targeted at enhancing the expression and synthesis of TFF peptides at optimal levels in the GIT epithelium, may constitute a plausible alternative strategy to the use of in-feed antibiotic growth promoters to maintain epithelial integrity and promote resistance to enteric pathogens. This review describes TFF peptides, with importance to their biological functions and involvement in gastrointestinal mucosal protection and repair in food animals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fasina, Obanla, Ekunseitan, Dosu, Richardson and Apalowo.)

Objective: Firearm injury research necessitates using data from often-exploited vulnerable populations of Black and Brown Americans. In order to reduce bias against protected attributes, this study provides a theoretical framework for establishing trust and transparency in the use of AI with the general population., Methods: We propose a Model Facts template that is easily extendable and decomposes accuracy and demographics into standardized and minimally complex values. This framework allows general users to assess the validity and biases of a model without diving into technical model documentation., Examples: We apply the Model Facts template on 2 previously published models, a violence risk identification model and a suicide risk prediction model. We demonstrate the ease of accessing the appropriate information when the data are structured appropriately., Discussion: The Model Facts template is limited in its current form to human based data and biases. Like nutrition facts, it will require educational programs for users to grasp its full utility. Human computer interaction experiments should be conducted to ensure model information is communicated accurately and in a manner that improves user decisions., Conclusion: The Model Facts label is the first framework dedicated to establishing trust with end users and general population consumers. Implementation of Model Facts into firearm injury research will provide public health practitioners and those impacted by firearm injury greater faith in the tools the research provides., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Despite increasing diversity in research recruitment, research finding reporting by gender, race, ethnicity, and sex has remained up to the discretion of authors. This study developped and piloted tools to standardize the inclusive reporting of gender, race, ethnicity, and sex in health research. A modified Delphi approach was used to develop standardized tools for the inclusive reporting of gender, race, ethnicity, and sex in health research. Health research, social epidemiology, sociology, and medical anthropology experts from 11 different universities participated in the Delphi process. The tools were pilot tested on 85 health research manuscripts in top health research journals to determine inter-rater reliability of the tools. The tools each spanned five dimensions for both sex and gender as well as race and ethnicity: Author inclusiveness, Participant inclusiveness, Nomenclature reporting, Descriptive reporting, and Outcomes reporting for each subpopulation. The sex and gender tool had a median score of 6 and a range of 1-15 out of 16 possible points. The percent agreement between reviewers piloting the sex and gender tool was 82%. The interrater reliability or average Cohen's Kappa was 0.54 with a standard deviation of 0.33 demonstrating moderate agreement. The race and ethnicity tool had a median score of 1 and a range of 0-15 out of 16 possible points. Race and ethnicity were both reported in only 25.8% of studies evaluated. Most studies that reported race reported only the largest subgroups; White, Black, and Latinx. The percent agreement between reviewers piloting the race and ethnicity tool was 84 and average Cohen's Kappa was 0.61 with a standard deviation of 0.38 demonstrating substantial agreement. While the overall dimension scores were low (indicating low inclusivity), the interrater reliability measures indicated moderate to substantial agreement for the respective tools. Efforts in recruitment alone will not provide more inclusive literature without improving reporting., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Stey et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: Opioid overdoses and violent injury are leading causes of death in the United States, yet testing for novel opioids like fentanyl remains uncommon. The purpose of this investigation is to characterize a population of victims of violence who test positive for illicit fentanyl., Methods: Retrospective cohort study of patients treated at a level-one trauma center between January 31, 2019 and February 21, 2020. Data were extracted from the electronic medical record. Subjects were included if they had an encounter diagnosis for a violent or intentional injury, using the International Classification of Diseases, v10 (X92-Y09). We excluded patients who received licit fentanyl as a part of their care before testing. Those who tested positive for fentanyl exposure on our standard hospital urine drug screen were considered to have been exposed to illicit fentanyl. Those testing negative for fentanyl were considered controls., Results: Of the 1132 patients treated for intentional injuries during the study period, 366 were included in the study (32.3%). Of these, 133 (36.3%) subjects were exposed to illicit fentanyl prehospital. There were no demographic differences between cases and controls. Cases had a lower GCS voice score on arrival (median = 4, interquartile range [IQR] = 4-5 versus median = 5, IQR = 4-5, P = 0.02), higher rates of ventilator usage (32.3% versus 21.5%, P = 0.02), and more intensive care unit admissions (27.1% versus 12.0%, P = 0.005). More than half of cases tested negative for opiates (78/133, 58.6%). Cases had more trauma center encounters (26.3% had ≥2 visits versus 15.5%)., Conclusions: Exposure to illicit fentanyl was common among victims of violence in this single-center study. These patients are at increased risk of being admitted to intensive care units and repeated trauma center visits, suggesting fentanyl testing may help identify those who could benefit from violence prevention and substance abuse treatment., (Published by Elsevier Inc.)

Background: Patient-physician communication is key to better clinical outcomes and patient well-being. Communication between trauma patients and their physicians remains relatively unexplored. We aimed to identify and characterize the range of strengths and challenges in patient-physician communication in the setting of trauma care., Methods: A qualitative, grounded theory approach was used to explore communication strengths and challenges for patients and residents. Patients previously admitted to the trauma service for violent injuries were recruited and interviewed in-person during their trauma clinic appointments. Surgical residents were recruited via email and interviewed virtually via Zoom. Anonymous, semistructured interviews were conducted until thematic saturation was reached., Results: Twenty-nine interviews with patients and 14 interviews with residents were conducted. Patients reported feeling ignored and misunderstood and having inadequate communication with physicians. Residents cited lack of time, patients' lack of health literacy, differences in background, and emotional responses to trauma as barriers to effective communication with patients. Patients and residents reported an understanding of each other's stressors, similar emotional experiences regarding traumatic stress, and a desire to communicate with each other in greater depth both inside and outside of the hospital., Conclusion: Trauma patients and residents can feel disconnected due to the lack of time for thorough communication and differences in background; however, they understand each other's stressors and share similar emotional responses regarding trauma and a desire for increased communication, connection, and solidarity. Leveraging these shared values to guide interventions, such as a resident curriculum, may help bridge disconnects and improve their communication., Level of Evidence: Therapeutic/Care Management; Level IV., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: The Black Lives Matter (BLM) protests against racialized police violence represents the most prolific mass social movement in modern times. It has been met by sustained and repressive violence by state authorities and right-wing groups. This review seeks to synthesize existing scholarly, journalistic, case report, and crowd sourced data on violence directed against BLM protestors., Recent Findings: Data from various sources suggests that police disproportionately target BLM protests for violent intervention. There is also mounting evidence of organized and vigilante right-wing violence targeting BLM protestors. While police frequently use chemical irritants and projectiles, right-wing protestors often use car ramming to bluntly injure protestors. The true scale and nature of injuries affecting BLM protestors remains unknown though injuries resulting in the need for intensive care, operative intervention, permanent morbidity, and mortality have been reported., Summary: State and conservative civilian violence against BLM protestors represents an ongoing threat to the right to organize and publicly dissent. The use of force manifested by police and right-wing groups against BLM protestors resulted in significant injury and mortality., Competing Interests: Conflict of InterestMihir J Chaudhary and Joseph Richardson Jr. have no conflicts of interest or financial disclosures., (© The Author(s) 2022.)

Recent high-profile incidents involving the deadly application of force in the United States sparked worldwide protests and renewed scrutiny of police practices as well as scrutiny of relations between police officers and minoritized communities. In this report, we consider the inappropriate use of force by police from the perspective of behavioral and social science inquiry related to aggression, violence, and intergroup relations. We examine the inappropriate use of force by police in the context of research on modern policing as well as critical race theory and offer five recommendations suggested by contemporary theory and research. Our recommendations are aimed at policymakers, law enforcement administrators, and scholars and are as follows: (1) Implement public policies that can reduce inappropriate use of force directly and through the reduction of broader burdens on the routine activities of police officers. (2) For officers frequently engaged in use-of-force incidents, ensure that best practice, evidence-based treatments are available and required. (3) Improve and increase the quality and delivery of noncoercive conflict resolution training for all officers, along with police administrative policies and supervision that support alternatives to the use of force, both while scaling back the militarization of police departments. (4) Continue the development and evaluation of multicomponent interventions for police departments, but ensure they incorporate evidence-based, field-tested components. (5) Expand research in the behavioral and social sciences aimed at understanding and managing use-of-force by police and reducing its disproportionate impact on minoritized communities, and expand funding for these lines of inquiry., (© 2021 Wiley Periodicals LLC.)

Rationale: Given the widespread availability of firearms, high prevalence of gun violence in the U.S., and the intersection of race, cumulative violence and adverse mental health outcomes, it is important to understand the mental health consequences of exposure to gun violence fatality on racially/ethnically diverse secondary victims., Objective: The aims of this study were to examine 1) the prevalence and demographic differences in exposure to gun violence fatality; 2) the associations between exposure and depression, psychological distress, suicidal ideation and psychosis-like experiences; and 3) the interaction between race and exposure in relation to depression, psychological distress, suicidal ideation and psychotic experiences., Methods: Participants (n=1615) were adult community residents from Baltimore, New York, Philadelphia, and Washington, D.C, who participated in the online Survey of Police-Public Encounters. Chi-square, linear, and logistic regression were used to test study aims., Results: Twenty-four percent of respondents reported exposure to gun violence fatality. Black, Latinx, younger, and those of lower income and education were disproportionately exposed. Exposed respondents had significantly higher levels of psychological distress, depression, suicidal ideation and/or psychotic experiences compared to those not exposed. There was a significantly stronger association between exposure and depression among Latinxs and "other" races relative to Whites., Conclusions: Findings suggest that vicarious exposure to gun violence fatality is widespread, disproportionately experienced by racial/ethnic minorities, and related to a higher prevalence of mental health symptoms. Implications of these findings are that clinicians should attend to the mental health needs of people vicariously exposed to gun violence fatality, and that gun violence reduction interventions may positively impact community-level mental health. Given that Blacks and Latinxs are disproportionately exposed to gun violence, a more extensive examination of exposure to gun violence fatality as a social determinant of mental health is warranted using longitudinal and nationally representative data., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Sporadic literature reports describe isolates of pathogenic bacteria that harbor an antibiotic resistance determinant but remain susceptible to the corresponding antibiotic as a consequence of a genetic defect. Such strains represent a source from which antibiotic resistance may reemerge to cause treatment failure in patients. Here, we report a systematic investigation into the prevalence and nature of this phenomenon, which we term s ilencing of a ntibiotic r esistance by m utation (SARM). Instances of SARM were detected among 1,470 Staphylococcus aureus isolates through side-by-side comparison of antibiotic resistance genotype (as determined by whole-genome sequencing) versus phenotype (as assessed through susceptibility testing). Of the isolates analyzed, 152 (10.3%) harbored a silenced resistance gene, including 46 (3.1%) that exhibited SARM to currently deployed antistaphylococcal drugs. SARM resulted from diverse mutational events but most commonly through frameshift mutation of resistance determinants as a result of point deletion in poly(A) tracts. The majority (∼90%) of SARM strains reverted to antibiotic resistance at frequencies of ≥10 -9 ; thus, while appearing antibiotic sensitive in the clinical microbiology laboratory, most S. aureus isolates exhibiting SARM will revert to antibiotic resistance at frequencies achievable in patients. In view of its prevalence in a major pathogen, SARM represents a significant potential threat to the therapeutic efficacy of antibiotics. IMPORTANCE Antibiotic resistance hinders the treatment of bacterial infection. To guide effective therapy, clinical microbiology laboratories routinely perform susceptibility testing to determine the antibiotic sensitivity of an infecting pathogen. This approach relies on the assumption that it can reliably distinguish bacteria capable of expressing antibiotic resistance in patients, an idea challenged by the present study. We report that the important human pathogen Staphylococcus aureus frequently carries antibiotic resistance genes that have become inactivated ("silenced") by mutation, leading strains to appear antibiotic sensitive. However, resistance can rapidly reemerge in most such cases, at frequencies readily achievable in infected patients. Silent antibiotic resistance is therefore prevalent, transient, and evades routine detection, rendering it a significant potential threat to antibacterial chemotherapy., (Copyright © 2019 Kime et al.)

There is a body of research over the last three decades that has focused on the etiology of violence among victims of violent injury. This body of literature indicates that Black men are disproportionately represented among victims of violent injury seen in emergency departments and trauma centers across the country. Despite the disproportionate number of low-income young Black men treated for violent injury in urban trauma units and the growing body of literature accompanying it, little is known about the unique methodological challenges violent injury researchers face when conducting research on this vulnerable population in a clinical setting. This article describes the unique and often nuanced methodological difficulties a research team encountered while conducting a longitudinal qualitative study on risk factors for repeat violent injury among low-income young Black male victims of violent injury treated at a Level II trauma center in the Eastern United States. Four methodological challenges are identified: (a) the identification and screening of participants, (b) recruitment and interviewing, (c) understanding hospital culture, policies, and procedures, and (d) retention and attrition of sample. Recommendations to overcome these challenges are offered.

Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstrate a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm(2) with 60 °C temperature difference between the hot side and cold side. The highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications.

Criminal justice involvement (CJI) disrupts social and sexual networks, and sexually transmitted infections (STIs) thrive on network disruption. Adolescent CJI may be a particularly important determinant of STI because experiences during adolescence influence risk trajectories into adulthood. We used Wave III (2001-2002: young adulthood) of the National Longitudinal Study of Adolescent Health (N = 14,322) to estimate associations between history of adolescent (younger than 18 years) CJI and adult STI risk. Respondents who reported a history of repeat arrest in adolescence, adolescent conviction, and arrest both as an adolescent and an adult (persistent arrest) had between two to seven times the odds of STI (biologically confirmed infection with chlamydia, gonorrhea, or trichomoniasis) in adulthood and between two to three times the odds of multiple partnerships and inconsistent condom use in the past year in adulthood. In analyses adjusting for sociodemographic and behavioral factors, history of having six or more adolescent arrests was associated with more than five times the odds of STI (adjusted odds ratio (AOR) 5.44, 95 % confidence interval (CI) 1.74-17.1). Both adolescent conviction and persistent CJI appeared to remain independent correlates of STI (conviction: AOR 1.90, 95 % CI 1.02-3.55; persistent CJI: AOR 1.60, 95 % CI 0.99-2.57). Adolescents who have repeat arrests, juvenile convictions, and persist as offenders into adulthood constitute priority populations for STI treatment and prevention. The disruptive effect of adolescent CJI may contribute to a trajectory associated with STI in adulthood.

Limited information exists regarding soft tissue and hard tissue responses to abutments with different material composition. The aim of this study is to evaluate soft and hard tissue responses to titanium and polymer healing abutments over a 3-month period. Sixteen patients were included in this prospective trial. Implants were provisionalized with either titanium or polymer healing abutments. Changes of marginal bone level and soft tissue dimensions were recorded at implant installation and at 3 months.

Actinobacillus actinomycetemcomitans is a facultatively intracellular pathogen and the aetiological agent of localized aggressive periodontitis. Screening of the genome of A. actinomycetemcomitans for in vivo-induced antigen determinants previously demonstrated that the proteome of this organism differs in laboratory culture compared with conditions found during active infection. The aim of the present study was to determine whether the bacterial gene expression pattern inferred with in vivo-induced antigen technology (IVIAT) in human infections was consistent with the gene expression pattern occurring upon epithelial cell association. To this end, a real-time PCR method was developed and used to quantify absolute and relative bacterial gene expression of A. actinomycetemcomitans grown extra- and intracellularly in two human epithelial cell lines (HeLa and IHGK). The amount of template used in the assay was normalized using the total count of viable bacteria (c.f.u.) as a reference point and performed in duplicate in at least two independent experiments. Controls for this experiment included 16S rRNA and gapdh. Transcription of all eight ORFs tested increased significantly (P < 0.05) in HeLa and IHGK cells compared with bacteria grown extracellularly. The concurrence of gene expression patterns found in the two models suggests that these epithelial cells are valid in vitro models of infection for the genes tested. IVIAT is an experimental platform that can be used as a validation tool to assess the reliability of animal and other models of infection and is applicable to most pathogens.