Economic demand analysis of within-session dose-reduction during nicotine self-administration.

BACKGROUND: This study determined if a within-session dose-reduction design sufficiently captures elasticity of demand for nicotine in male and female rats using environmental enrichment to manipulate demand elasticity. METHODS: Male and female Sprague-Dawley rats were trained to self-administer nicotine (60 µg/kg/infusion). In Experiment 1, rats began daily dose-reduction for nine sessions following acquisition. Rats then underwent a minimum of five within-session dose-reduction sessions where each dose was available for 10 min. In Experiment 2, rats were reared in isolated, social, or enriched housing followed by acquisition of nicotine self-administration. Rats then underwent within-session dose-reduction. Housing environments were then switched, followed by additional testing sessions. Consumption was calculated for each dose and exponential demand curves were fit. RESULTS: No sex differences in acquisition of nicotine self-administration were detected for either experiment. In experiment 1, demand intensity (Q0; estimated intake if nicotine were freely available), was higher with between- compared to within-session dose-reduction, although elasticity of demand (α; rate of decline in nicotine intake as a function of increasing unit price), was lower. In Experiment 2, animals reared in enrichment had fewer infusions during acquisition compared to animals in isolation. Enriched males had reduced demand intensity compared to both isolated and social males, whereas isolated females had reduced intensity compared to enriched females. CONCLUSIONS: The within-session dose-reduction procedure for nicotine self-administration replicated effects of environmental enrichment on consumption behaviors. Additionally, this procedure captured differences in nicotine demand due to sex, laying important groundwork for future translational research on mechanisms of nicotine dependence.

Overlapping Surgery in Plastic Surgery: An Analysis of Patient Safety and Clinical Outcomes.

BACKGROUND: Overlapping surgery is an important and controversial health care issue. To date, there is minimal evidence on the safety of overlapping surgery in plastic surgery. The purpose of this study was to evaluate and compare outcomes for patients undergoing overlapping surgery versus nonoverlapping surgery in plastic surgery. METHODS: This is a retrospective cohort study of consecutive patients undergoing plastic surgery procedures at a tertiary academic center between January of 2016 and January of 2018. Demographic and procedural characteristics, clinical outcomes, and adverse events were analyzed for patients undergoing overlapping versus nonoverlapping surgery. An a priori power analysis was performed, and chi-square, Wilcoxon rank sum, and bivariate logistic regression tests were used for analyses. RESULTS: Eight hundred sixty-six patients constituted the study population: 555 (64.1 percent) underwent nonoverlapping surgery and 311 (35.9 percent) underwent overlapping surgery. There was no significant difference (p > 0.050) in mean age, body mass index, tobacco use, American Society of Anesthesiologists rating, or Charlson Comorbidity Index score between cohorts. Comparison of nonoverlapping and overlapping cases revealed no differences in complications (12.1 percent versus 11.9 percent; p = 0.939), reoperations (6.1 percent versus 6.8 percent; p = 0.717), readmissions (3.6 percent versus 3.5 percent; p = 0.960), or emergency room visits (4.7 percent versus 4.8 percent; p = 0.927). Stratification by procedure demonstrated no difference (p > 0.050) in complications between cohorts. Median operative time was significantly longer for overlapping operations (105 minutes versus 83 minutes; p = 0.004). CONCLUSIONS: This study supports the safety of overlapping surgery in plastic surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Immediate Implant-Based Breast Reconstruction with Acellular Dermal Matrix: A Comparison of Sterile and Aseptic AlloDerm in 2039 Consecutive Cases.

BACKGROUND: Sterile ready-to-use acellular dermal matrix, introduced as an alternative to aseptic freeze-dried acellular dermal matrix for implant-based breast reconstruction, has been investigated in a limited number of studies. This study compared outcomes in implant-based breast reconstruction with ready-to-use and freeze-dried acellular dermal matrix. METHODS: The authors analyzed patients undergoing implant-based breast reconstruction with either freeze-dried or ready-to-use acellular dermal matrix, including demographics, clinical variables, and outcomes. An a priori power analysis was performed and logistic regression modeling was used to quantify the effect of acellular dermal matrix on outcomes while controlling for potential confounders. RESULTS: A total of 1285 consecutive patients undergoing 2039 immediate prosthetic breast reconstructions constituted the population: 612 (n = 910 breasts) with freeze-dried matrix and 673 (n = 1129 breasts) with ready-to-use acellular dermal matrix. The freeze-dried matrix cohort had a significantly higher rate of explantation compared with the ready-to-use matrix cohort (18.0 percent versus 12.0 percent; p = 0.0036), but surgical-site infection, wound dehiscence, mastectomy flap necrosis, seroma, and hematoma did not differ significantly between groups. On multivariate regression, patients undergoing reconstruction with freeze-dried matrix, compared to ready-to-use matrix, did not have higher odds of experiencing surgical-site infections (OR, 1.064; p = 0.7455), but did have higher odds of explantation (OR, 1.570; p = 0.0161). Tobacco use (OR, 2.809; p = 0.0002) and body mass index (OR, 1.054; p < 0.0001) were also independent predictors of explantation. CONCLUSION: Immediate implant-based breast reconstruction with sterile ready-to-use acellular dermal matrix has a comparable overall safety profile and a lower rate of prosthetic explantations compared with aseptic freeze-dried acellular dermal matrix. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Social Influences on Nicotine-Related Behaviors.

Cigarette smoking is the leading preventable cause of death in the United States. The number of new smokers, specifically among adolescents, has risen rapidly in recent years. Thus, understanding the role of social influences on patterns of nicotine and tobacco use is important. Clinical studies have addressed the impact social relationships such as family members and peers have on smoking acquisition and susceptibility. As well, preclinical animal models have examined the impact of social factors on drug intake, acquisition, maintenance, and relapse. For example, environmental enrichment (EE) is a multi-faceted model that includes social factors, exercise, and novelty, among others. This model has elucidated addiction-related neurobehavioral effects of these different factors. However, there is a dearth of literature examining the impact of social partners on nicotine addiction and underlying neural mechanisms. Here we discuss the importance of social factors on nicotine addiction vulnerability, and propose new directions for addiction research that integrate social aspects of nicotine use.

Microgravity modulation of syncytin-A expression enhance osteoclast formation.

Microgravity (µXg) experienced by astronauts during space flights causes accelerated bone loss. However, the molecular basis of µXg induced bone loss in space is unclear. Osteoclast (OCL) is the primary bone-resorbing cell. We previously demonstrated that simulated µXg promotes OCL formation. In this study, we identified that µXg induces syncytin-A expression in RAW264.7 preosteoclast cells without RANKL stimulation. We further tested the effect of osteotropic factors such as CXCL5 and 1,25(OH)2 D3 to regulate the syncytin-A expression in preosteoclast cells subjected to µXg compared to ground based (Xg) cultures. CXCL5 (25 ng/mL) and 1,25(OH)2 D3 (10 ng/mL) increased syncytin-A expression under Xg conditions. However, µXg alone upregulates syncytin-A expression compared to Xg control preosteoclast cells. Confocal microscopy using Lyso-Tracker identified syncytin-A expression co-localized with lysosomes in preosteoclast cells. Acridine orange staining showed RANKL elevated autophagy activity in these cells. Further, siRNA suppression of syncytin-A significantly inhibits autophagy activity in RAW264.7 cells. In addition, knockdown of syncytin-A expression inhibits µXg increased OCL formation in mouse bone marrow cultures. Thus, our findings suggest that targeting syncytin-A expression may be an effective countermeasure to control bone loss under microgravity conditions.

Covalent Incorporation of Heparin Improves Chondrogenesis in Photocurable Gelatin-Methacryloyl Hydrogels.

Multicomponent gelatin-methacryloyl (GelMA) hydrogels are regularly adopted for cartilage tissue engineering (TE) applications, where optimizing chemical modifications for preserving biofunctionality is often overlooked. This study investigates the biological effect of two different modification methods, methacrylation and thiolation, to copolymerize GelMA and heparin. The native bioactivity of methacrylated heparin (HepMA) and thiolated heparin (HepSH) is evaluated via thromboplastin time and heparan sulfate-deficient myeloid cell-line proliferation assay, demonstrating that thiolation is superior for preserving anticoagulation and growth factor signaling capacity. Furthermore, incorporating either HepMA or HepSH in chondrocyte-laden GelMA hydrogels, cultured for 5 weeks under chondrogenic conditions, promotes cell viability and chondrocyte phenotype. However, only GelMA-HepSH hydrogels yield significantly greater differentiation and matrix deposition in vitro compared to GelMA. This study demonstrates that thiol-ene chemistry offers a favorable strategy for incorporating bioactives into gelatin hydrogels as compared to methacrylation while furthermore highlighting GelMA-HepSH hydrogels as candidates for cartilage TE applications.

Thiol-Ene Clickable Gelatin: A Platform Bioink for Multiple 3D Biofabrication Technologies.

Bioprinting can be defined as the art of combining materials and cells to fabricate designed, hierarchical 3D hybrid constructs. Suitable materials, so called bioinks, have to comply with challenging rheological processing demands and rapidly form a stable hydrogel postprinting in a cytocompatible manner. Gelatin is often adopted for this purpose, usually modified with (meth-)acryloyl functionalities for postfabrication curing by free radical photopolymerization, resulting in a hydrogel that is cross-linked via nondegradable polymer chains of uncontrolled length. The application of allylated gelatin (GelAGE) as a thiol-ene clickable bioink for distinct biofabrication applications is reported. Curing of this system occurs via dimerization and yields a network with flexible properties that offer a wider biofabrication window than (meth-)acryloyl chemistry, and without additional nondegradable components. An in-depth analysis of GelAGE synthesis is conducted, and standard UV-initiation is further compared with a recently described visible-light-initiator system for GelAGE hydrogel formation. It is demonstrated that GelAGE may serve as a platform bioink for several biofabrication technologies by fabricating constructs with high shape fidelity via lithography-based (digital light processing) 3D printing and extrusion-based 3D bioprinting, the latter supporting long-term viability postprinting of encapsulated chondrocytes.

Regression of devil facial tumour disease following immunotherapy in immunised Tasmanian devils.

Devil facial tumour disease (DFTD) is a transmissible cancer devastating the Tasmanian devil (Sarcophilus harrisii) population. The cancer cell is the 'infectious' agent transmitted as an allograft by biting. Animals usually die within a few months with no evidence of antibody or immune cell responses against the DFTD allograft. This lack of anti-tumour immunity is attributed to an absence of cell surface major histocompatibility complex (MHC)-I molecule expression. While the endangerment of the devil population precludes experimentation on large experimental groups, those examined in our study indicated that immunisation and immunotherapy with DFTD cells expressing surface MHC-I corresponded with effective anti-tumour responses. Tumour engraftment did not occur in one of the five immunised Tasmanian devils, and regression followed therapy of experimentally induced DFTD tumours in three Tasmanian devils. Regression correlated with immune cell infiltration and antibody responses against DFTD cells. These data support the concept that immunisation of devils with DFTD cancer cells can successfully induce humoral responses against DFTD and trigger immune-mediated regression of established tumours. Our findings support the feasibility of a protective DFTD vaccine and ultimately the preservation of the species.

Spending on Hospital Care and Pediatric Psychology Service Use Among Adolescents and Young Adults With Cancer.

Objective: To examine the relationship between need-based pediatric psychology service use and spending on hospital care among adolescents and young adults (AYAs) with cancer. Methods: Billing data were obtained from 48 AYAs with cancer receiving need-based pediatric psychology services and a comparison cohort of 48 AYAs with cancer not receiving services. A factorial analysis of covariance examined group differences in spending for hospital care. Pending significant findings, a multivariate analysis of covariance was planned to examine the relationship between need-based pediatric psychology service use and spending for inpatient admissions, emergency department (ED) visits, and outpatient visits. Results: Spending for hospital care was higher among AYAs receiving need-based pediatric psychology services than in the comparison cohort (p < .001, ωPartial2 = .11). Group differences were driven by significantly higher spending for inpatient admissions and ED visits among AYAs receiving need-based pediatric psychology services. Conclusions: The behavioral and psychosocial difficulties warranting need-based pediatric psychology services may predict higher health care spending.

Mitogen-activated Tasmanian devil blood mononuclear cells kill devil facial tumour disease cells.

Devil facial tumour disease (DFTD) is a transmissible cancer that has brought the host species, the Tasmanian devil, to the brink of extinction. The cancer cells avoid allogeneic immune recognition by downregulating cell surface major histocompatibility complex (MHC) I expression. This should prevent CD8(+) T cell, but not natural killer (NK) cell, cytotoxicity. The reason why NK cells, normally reactive to MHC-negative cells, are not activated to kill DFTD cells has not been determined. The immune response of wild devils to DFTD, if it occurs, is uncharacterised. To investigate this, we tested 12 wild devils with DFTD, and found suggestive evidence of low levels of antibodies against DFTD cells in one devil. Eight of these devils were also analysed for cytotoxicity, however, none showed evidence for cytotoxicity against cultured DFTD cells. To establish whether mimicking activation of antitumour responses could induce cytotoxic activity against DFTD, Tasmanian devil peripheral blood mononuclear cells (PBMCs) were treated with either the mitogen Concanavalin A, the Toll-like receptor agonist polyinosinic:polycytidylic acid or recombinant Tasmanian devil IL-2. All induced the PBMC cells to kill cultured DFTD cells, suggesting that activation does not occur after encounter with DFTD cells in vivo, but can be induced. The identification of agents that activate cytotoxicity against DFTD target cells is critical for developing strategies to protect against DFTD. Such agents could function as adjuvants to induce functional immune responses capable of targeting DFTD cells and tumours in vivo.

Medication adherence decision-making among adolescents and young adults with cancer.

PURPOSE: Nearly half of all adolescents and young adults (AYAs) with cancer struggle to adhere to oral chemotherapy or antibiotic prophylactic medication included in treatment protocols. The mechanisms that drive non-adherence remain unknown, leaving health care providers with few strategies to improve adherence among their patients. The purpose of this study was to use qualitative methods to investigate the mechanisms that drive the daily adherence decision-making process among AYAs with cancer. METHODS: Twelve AYAs (ages 15-31) with cancer who had a current medication regimen that included oral chemotherapy or antibiotic prophylactic medication participated in this study. Adolescents and young adults completed a semi-structured interview and a card sorting task to elucidate the themes that impact adherence decision-making. Interviews were transcribed verbatim and coded twice by two independent raters to identify key themes and develop an overarching theoretical framework. RESULTS: Adolescents and young adults with cancer described adherence decision-making as a complex, multi-dimensional process influenced by personal goals and values, knowledge, skills, and environmental and social factors. Themes were generally consistent across medication regimens but differed with age, with older AYAs discussing long-term impacts and receiving physical support from their caregivers more than younger AYAs. CONCLUSIONS: The mechanisms that drive daily adherence decision-making among AYAs with cancer are consistent with those described in empirically-supported models of adherence among adults with other chronic medical conditions. These mechanisms offer several modifiable targets for health care providers striving to improve adherence among this vulnerable population.

New Visible-Light Photoinitiating System for Improved Print Fidelity in Gelatin-Based Bioinks.

Oxygen inhibition is a phenomenon that directly impacts the print fidelity of 3D biofabricated and photopolymerized hydrogel constructs. It typically results in the undesirable physical collapse of fabricated constructs due to impaired cross-linking, and is an issue that generally remains unreported in the literature. In this study, we describe a systematic approach to minimizing oxygen inhibition in photopolymerized gelatin-methacryloyl (Gel-MA)-based hydrogel constructs, by comparing a new visible-light initiating system, Vis + ruthenium (Ru)/sodium persulfate (SPS) to more conventionally adopted ultraviolet (UV) + Irgacure 2959 system. For both systems, increasing photoinitiator concentration and light irradiation intensity successfully reduced oxygen inhibition. However, the UV + I2959 system was detrimental to cells at both high I2959 concentrations and UV light irradiation intensities. The Vis + Ru/SPS system yielded better cell cyto-compatibility, where encapsulated cells remained >85% viable even at high Ru/SPS concentrations and visible-light irradiation intensities for up to 21 days, further highlighting the potential of this system to biofabricate cell-laden constructs with high shape fidelity, cell viability, and metabolic activity.

Immunology of a Transmissible Cancer Spreading among Tasmanian Devils.

Devil facial tumor disease (DFTD) is a transmissible cancer that has killed most of the Tasmanian devil (Sarcophilus harrissii) population. Since the first case appeared in the mid-1990s, it has spread relentlessly across the Tasmanian devil's geographic range. As Tasmanian devils only exist in Tasmania, Australia, DFTD has the potential to cause extinction of this species. The origin of DFTD was a Schwann cell from a female devil. The disease is transmitted when devils bite each other around the facial areas, a behavior synonymous with this species. Every devil that is 'infected' with DFTD dies from the cancer. Once the DFTD cells have been transmitted, they appear to develop into a cancer without inducing an immune response. The DFTD cancer cells avoid allogeneic recognition because they do not express MHC class I molecules on the cell surface. A reduced genetic diversity and the production of immunosuppressive cytokines may also contribute.

Topical Review: Theoretical Frameworks in Pediatric Adherence-Promotion Interventions: Research Findings and Methodological Implications.

OBJECTIVE: To summarize the guiding theoretical frameworks included in pediatric adherence-promotion interventions and characterize targeted domains using the theoretical domains framework (TDF), a standardized system developed by adult behavior change researchers. METHODS: A systematic review of PubMed, PsycINFO, and CINAHL databases identified 47 articles describing pediatric adherence-promotion interventions. Data extraction was completed independently by two authors. Targeted intervention domains were classified using the TDF. RESULTS: The majority of interventions did not cite a guiding theoretical framework or cited multiple theories with overlapping domains. The TDF was a reliable categorization system and suggested that pediatric adherence-promotion interventions most commonly target knowledge, skills, and social influences. CONCLUSIONS: Pediatric adherence-promotion interventions draw from a variety of theories and lack a consistent language for describing targeted domains. The adapted TDF proposed here is one method of reducing variability in intervention development and reporting and may facilitate efforts to identify the processes that improve adherence.

Mouse Model of Devil Facial Tumour Disease Establishes That an Effective Immune Response Can be Generated Against the Cancer Cells.

The largest carnivorous marsupial in Australia, the Tasmanian devil (Sarcophilus harrisii) is facing extinction in the wild due to a transmissible cancer known as Devil Facial Tumour Disease (DFTD). DFTD is a clonal cell line transmitted from host to host with 100% mortality and no known immunity. While it was first considered that low genetic diversity of the population of devils enabled the allograft transmission of DFTD recent evidence reveals that genetically diverse animals succumb to the disease. The lack of an immune response against the DFTD tumor cells may be due to a lack of immunogenicity of the tumor cells. This could facilitate transmission between devils. To test immunogenicity, mice were injected with viable DFTD cells and anti-DFTD immune responses analyzed. A range of antibody isotypes against DFTD cells was detected, indicating that as DFTD cells can induce an immune response they are immunogenic. This was supported by cytokine production, when splenocytes from mice injected with DFTD cells were cultured in vitro with DFTD cells and the supernatant analyzed. There was a significant production of IFN-γ and TNF-α following the first injection with DFTD cells and a significant production of IL-6 and IL-10 following the second injection. Splenocytes from naïve or immunized mice killed DFTD cells in in vitro cytotoxicity assays. Thus, they are also targets for immunological destruction. We conclude that as an immune response can be generated against DFTD cells they would be suitable targets for a vaccine.

Natural killer cell mediated cytotoxic responses in the Tasmanian devil.

The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against DFTD cells and foreign tumour cells. The two Tasmanian devils immunised with irradiated DFTD cells did not form cytotoxic or humoral responses against DFTD cells, even after multiple immunisations. However, following immunisation with xenogenic K562 cells, devils did produce cytotoxic responses and antibodies against this foreign tumour cell line. The cytotoxicity appeared to occur through the activity of natural killer (NK) cells in an antibody dependent manner. Classical NK cell responses, such as innate killing of DFTD and foreign cancer cells, were not observed. Cells with an NK-like phenotype comprised approximately 4 percent of peripheral blood mononuclear cells. The results of this study suggest that Tasmanian devils have NK cells with functional cytotoxic pathways. Although devil NK cells do not directly recognise DFTD cancer cells, the development of antibody dependent cell-mediated cytotoxicity presents a potential pathway to induce cytotoxic responses against the disease. These findings have positive implications for future DFTD vaccine research.