DNA methylation in the mouse cochlea promotes maturation of supporting cells and contributes to the failure of hair cell regeneration.

Mammalian hair cells do not functionally regenerate in adulthood but can regenerate at embryonic and neonatal stages in mice by direct transdifferentiation of neighboring supporting cells into new hair cells. Previous work showed loss of transdifferentiation potential of supporting cells is in part due to H3K4me1 enhancer decommissioning of the hair cell gene regulatory network during the first postnatal week. However, inhibiting this decommissioning only partially preserves transdifferentiation potential. Therefore, we explored other repressive epigenetic modifications that may be responsible for this loss of plasticity. We find supporting cells progressively accumulate DNA methylation at promoters of developmentally regulated hair cell genes. Specifically, DNA methylation overlaps with binding sites of Atoh1, a key transcription factor for hair cell fate. We further show that DNA hypermethylation replaces H3K27me3-mediated repression of hair cell genes in mature supporting cells, and is accompanied by progressive loss of chromatin accessibility, suggestive of facultative heterochromatin formation. Another subset of hair cell loci is hypermethylated in supporting cells, but not in hair cells. Ten-eleven translocation (TET) enzyme-mediated demethylation of these hypermethylated sites is necessary for neonatal supporting cells to transdifferentiate into hair cells. We also observe changes in chromatin accessibility of supporting cell subtypes at the single-cell level with increasing age: Gene programs promoting sensory epithelium development loses chromatin accessibility, in favor of gene programs that promote physiological maturation and function of the cochlea. We also find chromatin accessibility is partially recovered in a chronically deafened mouse model, which holds promise for future translational efforts in hearing restoration.

Left Ventricular Dysfunction Associated With Brain Death: Results From the Donor Heart Study.

BACKGROUND: Left ventricular dysfunction in potential donors meeting brain death criteria often results in nonuse of donor hearts for transplantation, yet little is known about its incidence or pathophysiology. Resolving these unknowns was a primary aim of the DHS (Donor Heart Study), a multisite prospective cohort study. METHODS: The DHS enrolled potential donors by neurologic determination of death (n=4333) at 8 organ procurement organizations across the United States between February 2015 and May 2020. Data included medications administered, serial diagnostic tests, and transthoracic echocardiograms (TTEs) performed: (1) within 48 hours after brain death was formally diagnosed; and (2) 24±6 hours later if left ventricular (LV) dysfunction was initially present. LV dysfunction was defined as an LV ejection fraction <50% and was considered reversible if LV ejection fraction was >50% on the second TTE. TTEs were also examined for presence of LV regional wall motion abnormalities and their reversibility. We assessed associations between LV dysfunction, donor heart acceptance for transplantation, and recipient 1-year survival. RESULTS: An initial TTE was interpreted for 3794 of the 4333 potential donors by neurologic determination of death. A total of 493 (13%) of these TTEs showed LV dysfunction. Among those donors with an initial TTE, LV dysfunction was associated with younger age, underweight, and higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) and troponin levels. A second TTE was performed within 24±6 hours for a subset of donors (n=224) with initial LV dysfunction; within this subset, 130 (58%) demonstrated reversibility. Sixty percent of donor hearts with normal LV function were accepted for transplant compared with 56% of hearts with reversible LV dysfunction and 24% of hearts with nonreversible LV dysfunction. Donor LV dysfunction, whether reversible or not, was not associated with recipient 1-year survival. CONCLUSIONS: LV dysfunction associated with brain death occurs in many potential heart donors and is sometimes reversible. These findings can inform decisions made during donor evaluation and help guide donor heart acceptance for transplantation.

Comparison of estimated GFR using cystatin C versus creatinine in pediatric kidney transplant recipients.

BACKGROUND: An accurate, rapid estimate of glomerular filtration rate (GFR) in kidney transplant patients affords early detection of transplant deterioration and timely intervention. This study compared the performance of serum creatinine (Cr) and cystatin C (CysC)-based GFR equations to measured GFR (mGFR) using iohexol among pediatric kidney transplant recipients. METHODS: CysC, Cr, and mGFR were obtained from 45 kidney transplant patients, 1-18 years old. Cr- and CysC-estimated GFR (eGFR) was compared against mGFR using the Cr-based (Bedside Schwartz, U25-Cr), CysC-based (Gentian CysC, CAPA, U25-CysC), and Cr-CysC combination (CKiD Cr-CysC, U25 Cr-CysC) equations in terms of bias, precision, and accuracy. Bland-Altman plots assessed the agreement between eGFR and mGFR. Secondary analyses evaluated the formulas in patients with biopsy-proven histological changes, and K/DOQI CKD staging. RESULTS: Bias was small with Gentian CysC (0.1 ml/min/1.73 m2); 88.9% and 37.8% of U25-CysC estimations were within 30% and 10% of mGFR, respectively. In subjects with histological changes on biopsy, Gentian CysC had a small bias and U25-CysC were more accurate-both with 83.3% of and 41.7% of estimates within 30% and 10% mGFR, respectively. Precision was better with U25-CysC, CKiD Cr-CysC, and U25 Cr-CysC. Bland-Altman plots showed the Bedside Schwartz, Gentian CysC, CAPA, and U25-CysC tend to overestimate GFR when > 100 ml/min/1.72 m2. CAPA misclassified CKD stage the least (whole cohort 24.4%, histological changes on biopsy 33.3%). CONCLUSIONS: In this small cohort, CysC-based equations with or without Cr may have better bias, precision, and accuracy in predicting GFR.

Impact of Preoperative Urinary Tract Infection Screening in Asymptomatic Women Undergoing Midurethral Sling.

INTRODUCTION: There is limited information regarding the utility of preoperative urine culture (Ucx) screening to decrease postoperative UTI rates following midurethral sling (MUS). HYPOTHESIS: The primary objective of this study was to determine if the rate of postoperative UTI within the first 6 weeks after surgery is lower in women undergoing MUS when preoperative Ucx is obtained compared to when it is not. Secondary objectives were to determine clinical factors associated with postoperative UTI risk. METHODS: This is a retrospective cohort study of women who did not have symptoms of or a diagnosis of cystitis at the time of their preoperative evaluation and are undergoing MUS. Patients were grouped into those who had preoperative Ucx screening within 6 weeks preceding surgery and those who did not. UTI rates 6 weeks following surgery were compared between groups. Additionally, factors impacting the risk of developing a UTI within 6 weeks of surgery were assessed. RESULTS: Among 661 patients, 13.2% had a UTI within the first 6 weeks. There was no significant difference in UTI rates between those who did and did not have preoperative Ucx, respectively (14.9% vs 10.2%, p = 0.09). On multivariable analysis, current smoker status (OR 3.02, 95% CI 1.10-8.26), history of recurrent UTI (OR 3.00, 95% CI 1.14-7.86), and requiring postoperative SIC (OR 8.75, 95% CI 1.83-41.74) were independently associated with a UTI within 6 weeks of MUS. CONCLUSION: Obtaining preoperative Ucx in asymptomatic women prior to MUS does not appear to be associated with lower postoperative UTIs rates within 6 weeks of surgery.

POU4F3 pioneer activity enables ATOH1 to drive diverse mechanoreceptor differentiation through a feed-forward epigenetic mechanism.

During embryonic development, hierarchical cascades of transcription factors interact with lineage-specific chromatin structures to control the sequential steps in the differentiation of specialized cell types. While examples of transcription factor cascades have been well documented, the mechanisms underlying developmental changes in accessibility of cell type-specific enhancers remain poorly understood. Here, we show that the transcriptional "master regulator" ATOH1-which is necessary for the differentiation of two distinct mechanoreceptor cell types, hair cells in the inner ear and Merkel cells of the epidermis-is unable to access much of its target enhancer network in the progenitor populations of either cell type when it first appears, imposing a block to further differentiation. This block is overcome by a feed-forward mechanism in which ATOH1 first stimulates expression of POU4F3, which subsequently acts as a pioneer factor to provide access to closed ATOH1 enhancers, allowing hair cell and Merkel cell differentiation to proceed. Our analysis also indicates the presence of both shared and divergent ATOH1/POU4F3-dependent enhancer networks in hair cells and Merkel cells. These cells share a deep developmental lineage relationship, deriving from their common epidermal origin, and suggesting that this feed-forward mechanism preceded the evolutionary divergence of these very different mechanoreceptive cell types.

Optimizing Ophthalmology Patient Education via ChatBot-Generated Materials: Readability Analysis of AI-Generated Patient Education Materials and The American Society of Ophthalmic Plastic and Reconstructive Surgery Patient Brochures.

PURPOSE: This study aims to compare the readability of patient education materials (PEM) of the American Society of Ophthalmic Plastic and Reconstructive Surgery to that of PEMs generated by the AI-chat bots ChatGPT and Google Bard. METHODS: PEMs on 16 common American Society of Ophthalmic Plastic and Reconstructive Surgery topics were generated by 2 AI models, ChatGPT 4.0 and Google Bard, with and without a 6th-grade reading level prompt modifier. The PEMs were analyzed using 7 readability metrics: Flesch Reading Ease Score, Gunning Fog Index, Flesch-Kincaid Grade Level, Coleman-Liau Index, Simple Measure of Gobbledygook Index Score, Automated Readability Index, and Linsear Write Readability Score. Each AI-generated PEM was compared with the equivalent American Society of Ophthalmic Plastic and Reconstructive Surgery PEM. RESULTS: Across all readability indices, PEM generated by ChatGPT 4.0 consistently had the highest readability scores, indicating that the material generated by this AI chatbot may be most difficult to read in its unprompted form (Flesch Reading Ease Score: 36.5; Simple Measure of Gobbledygook: 14.7). Google's Bard was able to generate content that was easier to read than both the American Society of Ophthalmic Plastic and Reconstructive Surgery and ChatGPT 4.0 (Flesch Reading Ease Score: 52.3; Simple Measure of Gobbledygook: 12.7). When prompted to produce PEM at a 6th-grade reading level, both ChatGPT 4.0 and Bard were able to significantly improve in their readability scores, with prompted ChatGPT 4.0 being able to consistently generate content that was easier to read (Flesch Reading Ease Score: 67.9, Simple Measure of Gobbledygook: 10.2). CONCLUSION: This study suggests that AI tools, when guided by appropriate prompts, can generate accessible and comprehensible PEMs in the field of ophthalmic plastic and reconstructive surgeries, balancing readability with the complexity of the necessary information.

Acellular Fish Skin Grafts for Treatment of Periocular Skin Defects.

PURPOSE: To describe the outcomes of acellular fish skin grafts for repair of periocular anterior lamella skin defects after Mohs surgery for skin cancers. METHODS: Following the institutional review board approval, we conducted a retrospective chart review of patients treated with acellular fish skin grafts between January 2022 and December 2023. Indication was to repair defects after Mohs excision of basal cell carcinoma and squamous cell carcinoma. Demographics, smoking and diabetes status, diagnosis, defect location, graft size, and complications were evaluated. Outcomes were analyzed using the scar cosmesis assessment and rating scale. RESULTS: Six patients (3 females and 3 males) with a mean age of 60.8 (range 44-80) had Mohs surgery for basal cell carcinoma (4) and squamous cell carcinoma (2). Location of defects included eyebrow (3 cases), lateral nasal wall (1 case), lower eyelid (1 case), and medial lower eyelid/nasal wall (1 case). Defect size ranged from 8 × 10 mm to 30 × 40 mm. Two patients had more than 1 application of xenograft. One patient developed a mild cicatricial ectropion. No other postoperative complications were seen, and all had good wound healing and cosmetically acceptable results. CONCLUSIONS: In this pilot study, acellular fish skin xenografts are shown to be promising skin graft substitutes in patients with Mohs defects and decrease the need for autologous skin harvesting or allogenic skin donation.

Kinematics of the Upper Eyelid and the Globe During Downward Excursion With Comparative Analysis in Patients With Thyroid Eye Disease.

PURPOSE: To analyze the kinematics of the upper eyelid and the globe on downward excursion for potential use in monitoring thyroid eye disease (TED) progression in an objective manner. METHODS: Ten normal volunteers and 10 patients with TED were studied. A high-speed (240 fps) digital camera with a coaxial light source set at a constant distance from the subjects' eyes was used to record the excursion of the upper eyelid and the globe from extreme upgaze to extreme downgaze. Clinical data, including age, gender, race, thyroid function tests, Vision, Inflammation/Congestion, Strabismus/motility restriction, Appearance/exposure score (primary surgeons' preference of TED grading system), exophthalmometry, and eyelid measurements were collected for all patients with TED. Frame-by-frame analyses of the videos were performed using Python software (version 3.6) and the Open Source Computer Vision Library. Temporal resolution was obtained by measuring the number of frames from initiation of eyelid and globe movement from extreme upgaze (t 0 ) to extreme downgaze (t f ). Spatial resolution was obtained by measuring the number of pixels the eyelid margin and the globe traversed from t 0 to t f . The data were then plotted on a graph to calculate the velocity of the upper eyelid and the globe during downward excursion. RESULTS: Velocimetric calculations using high-speed photography suggests that downward excursion of the upper eyelid, and the globe occurs in 2 phases: the acceleration phase and the deceleration phase. Comparative analysis of slow-motion videography demonstrates that patients with TED were found to have attenuation in the early acceleration phase of upper eyelid excursion compared with normal subjects. In patients with TED, the difference in velocity between the eyelid and the globe occurs in the early deceleration phase. CONCLUSIONS: The upper eyelid normally synchronizes intimately with the globe during downward eye movement. Data from this study reveal that attenuation mostly in the early deceleration phase of eyelid movement relative to the globe accounts for the dynamic eyelid lag seen on clinical examination. Further analysis is needed to show if a quantified von Graefe sign can be used as an objective means of monitoring progression in TED.

The Effect of Aromatherapy on Anxiety and Pain in Patients Undergoing Oculoplastic Surgery.

PURPOSE: To determine the effect of aromatherapy on postoperative anxiety and pain in patients undergoing oculoplastic surgery. METHODS: A randomized controlled study of 60 patients who underwent monitored anesthesia care sedation for oculoplastic procedures from August 2018 to November 2020. Patients were randomized to an aromatherapy (n = 32) or placebo (n = 28) condition. Anxiety was measured with State-Trait Anxiety Inventory and visual analog scale for anxiety. Pain was measured with a visual analog scale for pain. RESULTS: Compared with control patients, aromatherapy patients had significantly lower postoperative State-Trait Anxiety Inventory state anxiety (24.1 vs. 29.1; p = 0.05) and visual analog scale pain scores (1.9 vs. 3.2; p = 0.05). Aromatherapy patients also had shorter stays in the postanesthesia care unit than control patients (57.7 vs. 79.4 minutes; p = 0.03). CONCLUSIONS: Patients who received aromatherapy reported lower postoperative anxiety and pain. Aromatherapy may be a useful adjuvant analgesic and/or anxiolytic for patients undergoing oculoplastic procedures with monitored anesthesia care sedation.

Noninvasive Temperature Measurements in Tissue-Simulating Phantoms Using a Solid-State Near-Infrared Sensor.

The monitoring of body temperature is a recent addition to the plethora of parameters provided by wellness and fitness wearable devices. Current wearable temperature measurements are made at the skin surface, a measurement that is impacted by the ambient environment of the individual. The use of near-infrared spectroscopy provides the potential for a measurement below the epidermal layer of skin, thereby having the potential advantage of being more reflective of physiological conditions. The feasibility of noninvasive temperature measurements is demonstrated by using an in vitro model designed to mimic the near-infrared spectra of skin. A miniaturizable solid-state laser-diode-based near-infrared spectrometer was used to collect diffuse reflectance spectra for a set of seven tissue phantoms composed of different amounts of water, gelatin, and Intralipid. Temperatures were varied between 20-24 °C while collecting these spectra. Two types of partial least squares (PLS) calibration models were developed to evaluate the analytical utility of this approach. In both cases, the collected spectra were used without pre-processing and the number of latent variables was the only optimized parameter. The first approach involved splitting the whole dataset into separate calibration and prediction subsets for which a single optimized PLS model was developed. For this first case, the coefficient of determination (R2) is 0.95 and the standard error of prediction (SEP) is 0.22 °C for temperature predictions. The second strategy used a leave-one-phantom-out methodology that resulted in seven PLS models, each predicting the temperatures for all spectra in the held-out phantom. For this set of phantom-specific predicted temperatures, R2 and SEP values range from 0.67-0.99 and 0.19-0.65 °C, respectively. The stability and reproducibility of the sample-to-spectrometer interface are identified as major sources of spectral variance within and between phantoms. Overall, results from this in vitro study justify the development of future in vivo measurement technologies for applications as wearables for continuous, real-time monitoring of body temperature for both healthy and ill individuals.

Synchronizing Brain Rhythms to Improve Cognition.

Impaired cognition is common in many neuropsychiatric disorders and severely compromises quality of life. Synchronous electrophysiological rhythms represent a core mechanism for sculpting communication dynamics among large-scale brain networks that underpin cognition and its breakdown in neuropsychiatric disorders. Here, we review an emerging neuromodulation technology called transcranial alternating current stimulation that has shown remarkable early results in rapidly improving various domains of human cognition by modulating properties of rhythmic network synchronization. Future noninvasive neuromodulation research holds promise for potentially rescuing network activity patterns and improving cognition, setting groundwork for the development of drug-free, circuit-based therapeutics for people with cognitive brain disorders.

Tripterygium wilfordii derivative celastrol, a YAP inhibitor, has antifibrotic effects in systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is characterised by extensive tissue fibrosis maintained by mechanotranductive/proadhesive signalling. Drugs targeting this pathway are therefore of likely therapeutic benefit. The mechanosensitive transcriptional co-activator, yes activated protein-1 (YAP1), is activated in SSc fibroblasts. The terpenoid celastrol is a YAP1 inhibitor; however, if celastrol can alleviate SSc fibrosis is unknown. Moreover, the cell niches required for skin fibrosis are unknown. METHODS: Human dermal fibroblasts from healthy individuals and patients with diffuse cutaneous SSc were treated with or without transforming growth factor ß1 (TGFß1), with or without celastrol. Mice were subjected to the bleomycin-induced model of skin SSc, in the presence or absence of celastrol. Fibrosis was assessed using RNA Sequencing, real-time PCR, spatial transcriptomic analyses, Western blot, ELISA and histological analyses. RESULTS: In dermal fibroblasts, celastrol impaired the ability of TGFß1 to induce an SSc-like pattern of gene expression, including that of cellular communication network factor 2, collagen I and TGFß1. Celastrol alleviated the persistent fibrotic phenotype of dermal fibroblasts cultured from lesions of SSc patients. In the bleomycin-induced model of skin SSc, increased expression of genes associated with reticular fibroblast and hippo/YAP clusters was observed; conversely, celastrol inhibited these bleomycin-induced changes and blocked nuclear localisation of YAP. CONCLUSIONS: Our data clarify niches within the skin activated in fibrosis and suggest that compounds, such as celastrol, that antagonise the YAP pathway may be potential treatments for SSc skin fibrosis.

Complete spectrum of adverse events associated with chimeric antigen receptor (CAR)-T cell therapies.

Chimeric antigen receptor (CAR)-T cell therapies have been approved by FDA to treat relapsed or refractory hematological malignancies. However, the adverse effects of CAR-T cell therapies are complex and can be challenging to diagnose and treat. In this review, we summarize the major adverse events, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and CAR T-cell associated HLH (carHLH), and discuss their pathophysiology, symptoms, grading, and diagnosis systems, as well as management. In a future outlook, we also provide an overview of measures and modifications to CAR-T cells that are currently being explored to limit toxicity.

The impact of diabetes mellitus on pelvic organ prolapse recurrence after robotic sacrocolpopexy.

INTRODUCTION AND HYPOTHESIS: Data examining the effect of diabetes mellitus (DM) on prolapse recurrence after sacrocolpopexy (SCP) is limited. The primary objective of this study was to determine if DM affects prolapse recurrence after robotic SCP. METHODS: This was a retrospective cohort study of women who underwent robotic SCP between 2012 and 2019 at Kaiser Permanente Southern California. The cohort was divided into women with and without DM at the time of SCP. The primary outcome was composite failure. Secondary outcomes included recurrent compartment-specific prolapse, reoperation rates, and surgical complications. RESULTS: Of 547 patients included, 100 had DM. Women with DM were older, had higher BMI, higher parity, and were more likely to be nonwhite. Women with DM had more advanced prolapse at baseline but were not more likely to undergo concomitant procedures at the time of SCP. Over a median follow-up of 2.1 years (IQR 1.3, 3.4), women with DM had significantly increased risk of anterior vaginal prolapse (AVP) recurrence (13% vs 3%, p<0.01), but not composite failure (21% vs 14%, p=0.14). On multivariate regression, women with DM were almost 4 times as likely to experience AVP recurrence over time (AVP hazard ratio (HR) 3.93, 95% CI 1.29-12.03, p=0.02). CONCLUSION: In our cohort, DM was a risk factor for AVP recurrence but not composite failure after robotic SCP.

"We're trained to trust our patients": a qualitative study on the general practitioners' trust in patients for colorectal cancer shared care.

BACKGROUND: In a therapeutic partnership, physicians rely on patients to describe their health conditions, join in shared decision-making, and engage with supported self-management activities. In shared care, the patient, primary care, and specialist services partner together using agreed processes and outputs for the patient to be placed at the centre of their care. However, few empirical studies have explored physicians' trust in patients and its implications for shared care models. AIM: To explore trust in patients amongst general practitioners (GPs), and the impacts of trust on GPs' willingness to engage in new models of care, such as colorectal cancer shared care. METHODS: GP participants were recruited through professional networks for semi-structured interviews. Transcripts were integrity checked, coded inductively, and themes developed iteratively. RESULTS: Twenty-five interviews were analysed. Some GPs view trust as a responsibility of the physician and have a high propensity for trusting patients. For other GPs, trust in patients is developed over successive consultations based on patient characteristics such as honesty, reliability, and proactivity in self-care. GPs were more willing to engage in colorectal cancer shared care with patients with whom they have a developed, trusting relationship. CONCLUSIONS: Trust plays a significant role in the patient's access to shared care. The implementation of shared care should consider the relational dynamics between the patient and health care providers.

In a therapeutic partnership, physicians rely on patients to describe their health conditions, join in shared decision-making and engage with supported self-management activities. In shared care, the patient, primary care, and specialist services partner together using agreed processes and outputs for the patient to be placed at the centre of their care. Trust is key to this partnership. However, few studies have explored the physicians' trust in patients and its implications for shared care models. This study aims to explore trust in patients amongst general practitioners (GPs), and the impacts of trust on GPs' willingness to engage in new models of care, such as colorectal cancer shared care. After analysing 25 interview transcripts with GPs, we found some GPs view trust as a responsibility of the physicians, while in others, trust in patients developed over successive consultations based on patient characteristics such as honesty, reliability, and proactivity in self-care. GPs were more willing to engage in colorectal cancer shared care with patients whom they have a developed, trusting relationship. Trust plays a significant role in the patient's access to shared care. The rollout of shared care should consider the relational dynamics between the patient and health care providers.

Ambient intelligence-based monitoring of staff and patient activity in the intensive care unit.

BACKGROUND: Caregiver workload in the ICU setting is difficult to numerically quantify. Ambient Intelligence utilises computer vision-guided neural networks to continuously monitor multiple datapoints in video feeds, has become increasingly efficient at automatically tracking various aspects of human movement. OBJECTIVES: To assess the feasibility of using Ambient Intelligence to track and quantify allpatient and caregiver activity within a bedspace over the course of an ICU admission and also to establish patient specific factors, and environmental factors such as time ofday, that might contribute to an increased workload in ICU workers. METHODS: 5000 images were manually annotated and then used to train You Only LookOnce (YOLOv4), an open-source computer vision algorithm. Comparison of patientmotion and caregiver activity was then performed between these patients. RESULTS: The algorithm was deployed on 14 patients comprising 1762800 framesof new, untrained data. There was a strong correlation between the number ofcaregivers in the room and the standardized movement of the patient (p < 0.0001) withmore caregivers associated with more movement. There was a significant difference incaregiver activity throughout the day (p < 0.05), HDU vs. ICU status (p < 0.05), delirious vs. non delirious patients (p < 0.05), and intubated vs. not intubated patients(p < 0.05). Caregiver activity was lowest between 0400 and 0800 (average .71 ± .026caregivers per hour) with statistically significant differences in activity compared to 0800-2400 (p < 0.05). Caregiver activity was highest between 1200 and 1600 (1.02 ± .031 caregivers per hour) with a statistically significant difference in activity comparedto activity from 1600 to 0800 (p < 0.05). The three most dominant predictors of workeractivity were patient motion (Standardized Dominance 78.6%), Mechanical Ventilation(Standardized Dominance 7.9%) and Delirium (Standardized Dominance 6.2%). CONCLUSION: Ambient Intelligence could potentially be used to derive a single standardized metricthat could be applied to patients to illustrate their overall workload. This could be usedto predict workflow demands for better staff deployment, monitoring of caregiver workload, and potentially as a tool to predict burnout.

Can membrane composition traffic toxins? Mycolactone and preferential membrane interactions.

Mycolactone is a cytotoxic and immunosuppressive macrolide produced by Mycobacterium ulcerans and the sole causative agent of the neglected tropical skin disease Buruli ulcer. The toxin acts by invading host cells and interacting with intracellular targets to disrupt multiple fundamental cellular processes. Mycolactone's amphiphilic nature enables strong interactions with lipophilic environments, including cellular membranes; however, the specificity of these interactions and the role of membranes in the toxin's pathogenicity remain unknown. It is likely that preferential interactions with lipophilic carriers play a key role in the toxin's distribution in the host, which, if understood, could provide insights to aid in the development of needed diagnostics for Buruli ulcer disease. In this work, molecular dynamics simulations were combined with enhanced free-energy sampling to characterize mycolactone's association with and permeation through models of the mammalian endoplasmic reticulum (ER) and plasma membranes (PMs). We find that increased order in the PMs not only leads to a different permeation mechanism compared with that in the ER membrane but also an energetic driving force for ER localization. Increased hydration, membrane deformation, and preferential interactions with unsaturated lipid tails stabilize the toxin in the ER membrane, while disruption of lipid packing is a destabilizing force in the PMs.

Challenges encountered in conducting donor-based research: Lessons learned from the Donor Heart Study.

Solid organ transplantation continues to be constrained by a lack of suitable donor organs. Advances in donor management and evaluation are needed to address this shortage, but the performance of research studies in deceased donors is fraught with challenges. Here we discuss several of the major obstacles we faced in the conduct of the Donor Heart Study-a prospective, multi-site, observational study of donor management, evaluation, and acceptance for heart transplantation. These included recruitment and engagement of participating organ procurement organizations, ambiguities related to study oversight, obtaining authorization for donor research, logistical challenges encountered during donor management, sustaining study momentum, and challenges related to study data management. By highlighting these obstacles encountered, as well as the solutions implemented, we hope to stimulate further discussion and actions that will facilitate the design and execution of future donor research studies.

Quantitative contributions of TNF receptor superfamily members to CD8+ T-cell responses.

T-cell responses to infections and cancers are regulated by co-signalling receptors grouped into the binary categories of co-stimulation or co-inhibition. The co-stimulation TNF receptor superfamily (TNFRSF) members 4-1BB, CD27, GITR and OX40 have similar signalling mechanisms raising the question of whether they have similar impacts on T-cell responses. Here, we screened for the quantitative impact of these TNFRSFs on primary human CD8+ T-cell cytokine production. Although both 4-1BB and CD27 increased production, only 4-1BB was able to prolong the duration over which cytokine was produced, and both had only modest effects on antigen sensitivity. An operational model explained these different phenotypes using shared signalling based on the surface expression of 4-1BB being regulated through signalling feedback. The model predicted and experiments confirmed that CD27 co-stimulation increases 4-1BB expression and subsequent 4-1BB co-stimulation. GITR and OX40 displayed only minor effects on their own but, like 4-1BB, CD27 could enhance GITR expression and subsequent GITR co-stimulation. Thus, different co-stimulation receptors can have different quantitative effects allowing for synergy and fine-tuning of T-cell responses.

Human CD8+ T Cells Exhibit a Shared Antigen Threshold for Different Effector Responses.

T cells recognizing cognate pMHC Ags become activated to elicit a myriad of cellular responses, such as target cell killing and the secretion of different cytokines, that collectively contribute to adaptive immunity. These effector responses have been hypothesized to exhibit different Ag dose and affinity thresholds, suggesting that pathogen-specific information may be encoded within the nature of the Ag. In this study, using systematic experiments in a reductionist system, in which primary human CD8+ T cell blasts are stimulated by recombinant peptides presented on MHC Ag alone, we show that different inflammatory cytokines have comparable Ag dose thresholds across a 25,000-fold variation in affinity. Although costimulation by CD28, CD2, and CD27 increased cytokine production in this system, the Ag threshold remained comparable across different cytokines. When using primary human memory CD8+ T cells responding to autologous APCs, equivalent thresholds were also observed for different cytokines and killing. These findings imply a simple phenotypic model of TCR signaling in which multiple T cell responses share a common rate-limiting threshold and a conceptually simple model of CD8+ T cell Ag recognition, in which Ag dose and affinity do not provide any additional response-specific information.