In this paper, we demonstrate the successful in vivo extended release of a small molecular weight therapeutic, ketotifen fumarate (MW=425), from molecularly imprinted, therapeutic contact lenses. ...This is the first time that a steady, effective concentration of drug is maintained in the tear film from a contact lens for an extended period of time for the entire duration of lens wear. Poly(HEMA-co-AA-co-AM-co-NVP-co-PEG200DMA) soft contact lenses were prepared (100±5μm thickness, diameter 11.8mm, power zero), and a constant tear film concentration of 170±30μg/mL was measured for up to 26hrs in a New Zealand white rabbit model. The results showed a dramatic increase in ketotifen mean residence time (MRT) and bioavailability compared to topical drop therapy and drug soaked lenses. The MRT for imprinted lenses was 12.47±3.99hrs, ~4 and 50 fold greater than non-imprinted lenses and 0.035% eye drops (Zaditor®), respectively. Furthermore, AUC0–26hrs was 9 and 94 fold greater for imprinted lenses than non-imprinted lenses and eye drops, respectively. The results indicate that molecular imprinting provides an exciting rational engineering strategy for sustained release. It is clear that imprinted lenses are very promising combination devices and are much more effective and efficient delivery devices than eye drops.
This is the first time that a steady, effective concentration of ketotifen fumarate is maintained in ocular tear film from an imprinted contact lens for an extended period of time. Display omitted
•Protocols for cytotoxicological assessment of 3D cell cultures must be adapted.•Collagen matrices induce a dilution of the effective cytotoxicity assay concentration.•Diffusion and bioavailability ...of test substances in 3D matrices must be considered.•Viability of immortalized cervical cells in 2D and 3D cell cultures are comparable.•Results apply to cytotoxicity assays and to exposure protocols (nanoparticles/drugs).
Comparisons of 2D and 3D cell culture models in literature have indicated differences in cellular morphology and metabolism, commonly attributed the better representation of in vivo conditions of the latter cell culture environment. Thus, interest in the use of 3D collagen gels for in vitro analysis has been growing. Although comparative studies to date have indicated an enhanced resistance of cells on collagen matrices against different toxicants, in the present study it is demonstrated that non-adapted protocols can lead to misinterpretation of results obtained from classical colorimetric dye-based cytotoxic assays. Using the well established Alamar blue assay, the study demonstrates how the transfer from 2D substrates to 3D collagen matrices can affect the uptake of the resazurin itself, affecting the outcome of the assay. Using flow cytometry, it is demonstrated that the cell viability is unaffected when cells are grown on collagen matrices, thus the difference seen in the fluorescence is a result of a dilution of the resazurin dye in the collagen matrix, and an increased uptake rate due to the larger cell surface exposed to the surrounding environment, facilitating more effective diffusion through the cellular membrane. The results are supported by a rate equation based simulation, verifying that differing uptake kinetics can result in apparently different cell viability. Finally, this work highlights the feasibility to apply classical dye-based assays on collagen based 3D cell culture models. However, the diffusion and bioavailability of test substances in 3D matrices used in in vitro toxicological assays must be considered and adaption of the protocols is necessary for direct comparison with the traditional 2D models. Moreover, the observations made based on the resazurin dye can be applied to drugs or nanoparticles which freely diffuse through the collagen matrices, thus affecting the effective concentration exposed to the cells.
Major depressive disorder (MDD) is a common complex disorder with a partly genetic etiology. We conducted a genome-wide association study of the MDD2000+ sample (2431 cases, 3673 screened controls ...and >1 M imputed single-nucleotide polymorphisms (SNPs)). No SNPs achieved genome-wide significance either in the MDD2000+ study, or in meta-analysis with two other studies totaling 5763 cases and 6901 controls. These results imply that common variants of intermediate or large effect do not have main effects in the genetic architecture of MDD. Suggestive but notable results were (a) gene-based tests suggesting roles for adenylate cyclase 3 (ADCY3, 2p23.3) and galanin (GAL, 11q13.3); published functional evidence relates both of these to MDD and serotonergic signaling; (b) support for the bipolar disorder risk variant SNP rs1006737 in CACNA1C (P=0.020, odds ratio=1.10); and (c) lack of support for rs2251219, a SNP identified in a meta-analysis of affective disorder studies (P=0.51). We estimate that sample sizes 1.8- to 2.4-fold greater are needed for association studies of MDD compared with those for schizophrenia to detect variants that explain the same proportion of total variance in liability. Larger study cohorts characterized for genetic and environmental risk factors accumulated prospectively are likely to be needed to dissect more fully the etiology of MDD.
Efforts are underway to transform regulatory toxicology and chemical safety assessment from a largely empirical science based on direct observation of apical toxicity outcomes in whole organism ...toxicity tests to a predictive one in which outcomes and risk are inferred from accumulated mechanistic understanding. The adverse outcome pathway (AOP) framework provides a systematic approach for organizing knowledge that may support such inference. Likewise, computational models of biological systems at various scales provide another means and platform to integrate current biological understanding to facilitate inference and extrapolation. We argue that the systematic organization of knowledge into AOP frameworks can inform and help direct the design and development of computational prediction models that can further enhance the utility of mechanistic and in silico data for chemical safety assessment. This concept was explored as part of a workshop on AOP-Informed Predictive Modeling Approaches for Regulatory Toxicology held September 24-25, 2015. Examples of AOP-informed model development and its application to the assessment of chemicals for skin sensitization and multiple modes of endocrine disruption are provided. The role of problem formulation, not only as a critical phase of risk assessment, but also as guide for both AOP and complementary model development is described. Finally, a proposal for actively engaging the modeling community in AOP-informed computational model development is made. The contents serve as a vision for how AOPs can be leveraged to facilitate development of computational prediction models needed to support the next generation of chemical safety assessment.
The Diels–Alder reaction, a 4 + 2 cycloaddition of a conjugated diene to a dienophile, is one of the most powerful reactions in synthetic chemistry. Biocatalysts capable of unlocking new and ...efficient Diels–Alder reactions would have major impact. Here we present a molecular-level description of the reaction mechanism of the spirotetronate cyclase AbyU, an enzyme shown here to be a bona fide natural Diels–Alderase. Using enzyme assays, X-ray crystal structures, and simulations of the reaction in the enzyme, we reveal how linear substrate chains are contorted within the AbyU active site to facilitate a transannular pericyclic reaction. This study provides compelling evidence for the existence of a natural enzyme evolved to catalyze a Diels–Alder reaction and shows how catalysis is achieved.
Reward function appears to be modulated by the circadian system, but little is known about the neural basis of this interaction. Previous research suggests that the neural reward response may be ...different in the afternoon; however, the direction of this effect is contentious. Reward response may follow the diurnal rhythm in self-reported positive affect, peaking in the early afternoon. An alternative is that daily reward response represents a type of prediction error, with neural reward activation relatively high at times of day when rewards are unexpected (i.e., early and late in the day). The present study measured neural reward activation in the context of a validated reward task at 10.00 h, 14.00 h, and 19.00 h in healthy human males. A region of interest BOLD fMRI protocol was used to investigate the diurnal waveform of activation in reward-related brain regions. Multilevel modeling found, as expected, a highly significant quadratic time-of-day effect focusing on the left putamen (
< 0.001). Consistent with the "prediction error" hypothesis, activation was significantly higher at 10.00 h and 19.00 h compared with 14.00 h. It is provisionally concluded that the putamen may be particularly important in endogenous priming of reward motivation at different times of day, with the pattern of activation consistent with circadian-modulated reward expectancies in neural pathways (i.e., greater activation to reward stimuli at unexpected times of day). This study encourages further research into circadian modulation of reward and underscores the methodological importance of accounting for time of day in fMRI protocols.
This is one of the first studies to use a repeated-measures imaging procedure to explore the diurnal rhythm of reward activation. Although self-reported reward (most often operationalized as positive affect) peaks in the afternoon, the present findings indicate that neural activation is lowest at this time. We conclude that the diurnal neural activation pattern may reflect a prediction error of the brain, where rewards at unexpected times (10.00 h and 19.00 h) elicit higher activation in reward brain regions than at expected (14.00 h) times. These data also have methodological significance, suggesting that there may be a time of day influence, which should be accounted for in neural reward studies.
Background and ImportanceIn Ireland, numbers of prescribed opioids are increasing yearly, out of proportion to population increase1. Acute hospitals are a major source of initial opioid prescriptions ...into communities 2. The Health Service Executive (HSE) has published opioid prescribing guidelines for the management of acute non-cancer pain, post-operative pain and post-procedure pain, specifically addressing the use of slow-release opioids, duration of prescription and avoidance of diversion following discharge 3.At our hospital, there is no standardised approach to opioid prescribing in this population. A baseline point prevalence survey (PPS) of opioid prescribing in this population by surgical teams was conducted.Aim and Objectives• To characterise opioid prescribing for acute non-cancer pain, post-operative pain and post-procedure pain in a tertiary healthcare setting• To inform local policy development on appropriate opioid use.Material and MethodsThe PPS took place on a single day in May 2023. Approval to conduct the survey was sought from the hospital Quality and Patient Safety Dept. All adult patients admitted to our hospital under a surgical team were included. The inpatient medication prescription record and medical notes for each patient were reviewed by a clinical pharmacist. Opioid prescription details were recorded on a data collection form hosted on Microsoft Forms.Results72% of study population (n=205) were prescribed an opioid; total of 224 opioid prescriptionsMost common indication, 43%, was acute postoperative pain (97/224)27% (61/224) of prescriptions were for slow-release formulations30% (67/224) of opioid prescriptions were prescribed for > 1 week97% (218/224) of opioid prescriptions were commenced during the current admissionFigures 1 & 2 respectively, summarise the opioid agent and formulation prescribed.Conclusion and RelevanceThis 1-day snapshot audit has presented several areas for improvement at our hospital, specifically the use of slow-release opioids, treatment duration and discharge prescription. Several quality improvement initiatives are being initiated as part of a wider opioid stewardship programme in line with the HSE National Clinical Programme for Anaesthesia.References and/or Acknowledgements1. HSE PCRS Data Sources. Annual reports. https://www.sspcrs.ie/portal/annual-reporting2. US National Survey on Drug Use and Health. https://www.samhsa.gov/data/sites/default/files/cbhsqreports/NSDUHMethodsSummDefs2018/NSDUHMethodsSummDefs2018.htm3. HSE National Clinical Programme for Anaesthesia. Guidance for Opioid Prescribing for Acute Non-cancer Pain, Post-operative Pain and Post-procedure Pain, 2022.Conflict of InterestNo conflict of interest.
Sleep, depressive symptoms and circadian preference are highly interconnected processes. Evidence suggests that, especially in adolescence, all processes should be considered in the assessment and ...treatment of patients with clinically relevant psychopathology. The SCRAM (Sleep, Circadian Rhythms, and Mood) questionnaire was developed and validated in a student sample as a promising tool to conjointly measure and separate sleep, circadian preference and depression symptomatology. The present study aims to validate a German version of the SCRAM questionnaire in an adolescent psychiatric inpatient sample. A two-step analytic strategy consisting of an exploratory factor analysis EFA followed by confirmatory factor analyses (CFA) was conducted. The EFA was run in the first half of the sample (n = 422, M = 14.92, SD = 1.67). To validate the factor structure of the EFA and the original study, two CFA`s were performed in the second half of the adolescent sample (n = 438, M = 15.07, SD = 1.68). The EFA analysis revealed a 4-factor model with 12 items. Two Sleep items and one Morningness item had cross-factor loadings. The fit indices in the CFA were good using the factor model of the original study, whereas the 4-factor model of the EFA did not converge. The German SCRAM factor model seems structurally sound in an adolescent inpatient sample, but questions remain regarding the role of diagnosis, gender, external correlates, and examining the change scores of the SCRAM scores with treatment. Before this application, further research is needed to replicate the factor structure, investigate test-retest reliability, predictive and discriminant validity and test in more generalizable samples.
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