Mechanical Actuation of Organoids in Synthetic Microenvironments.

Organoids are a powerful model system to explore the role of mechanical forces in sculpting emergent tissue cytoarchitecture. The modulation of the mechanical microenvironment is most readily performed using synthetic extracellular matrices (ECM); however, such materials provide passive, rather than active force modulation. Actuation technologies enable the active tuning of mechanical forces in both time and magnitude. Using such instruments, our group has shown that extrinsically imposed stretching on human neural tube organoids (hNTOs) enhanced patterning of the floor plate domain. Here, we provide a detailed protocol on the implementation of mechanical actuation of organoids embedded in synthetic 3D microenvironments, with additional details on methods to characterize organoid fate and behavior. Our protocol is easy to reproduce and is expected to be broadly applicable to investigate the role of active mechanics with in vitro model systems.

Comprehensive tool for a phase compensation reconstruction method in digital holographic microscopy operating in non-telecentric regime.

Quantitative phase imaging (QPI) via Digital Holographic microscopy (DHM) has been widely applied in material and biological applications. The performance of DHM technologies relies heavily on computational reconstruction methods to provide accurate phase measurements. Among the optical configuration of the imaging system in DHM, imaging systems operating in a non-telecentric regime are the most common ones. Nonetheless, the spherical wavefront introduced by the non-telecentric DHM system must be compensated to provide undistorted phase measurements. The proposed reconstruction approach is based on previous work from Kemper's group. Here, we have reformulated the problem, reducing the number of required parameters needed for reconstructing phase images to the sensor pixel size and source wavelength. The developed computational algorithm can be divided into six main steps. In the first step, the selection of the +1-diffraction order in the hologram spectrum. The interference angle is obtained from the selected +1 order. Secondly, the curvature of the spherical wavefront distorting the sample's phase map is estimated by analyzing the size of the selected +1 order in the hologram's spectrum. The third and fourth steps are the spatial filtering of the +1 order and the compensation of the interference angle. The next step involves the estimation of the center of the spherical wavefront. An optional final optimization step has been included to fine-tune the estimated parameters and provide fully compensated phase images. Because the proper implementation of a framework is critical to achieve successful results, we have explicitly described the steps, including functions and toolboxes, required for reconstructing phase images without distortions. As a result, we have provided open-access codes and a user interface tool with minimum user input to reconstruct holograms recorded in a non-telecentric DHM system.

Global Stress Detection Framework Combining a Reduced Set of HRV Features and Random Forest Model.

Approximately 65% of the worldwide adult population has experienced stress, affecting their daily routine at least once in the past year. Stress becomes harmful when it occurs for too long or is continuous (i.e., chronic), interfering with our performance, attention, and concentration. Chronic high stress contributes to major health issues such as heart disease, high blood pressure, diabetes, depression, and anxiety. Several researchers have focused on detecting stress through combining many features with machine/deep learning models. Despite these efforts, our community has not agreed on the number of features to identify stress conditions using wearable devices. In addition, most of the reported studies have been focused on person-specific training and testing. Thanks to our community's broad acceptance of wearable wristband devices, this work investigates a global stress detection model combining eight HRV features with a random forest (RF) algorithm. Whereas the model's performance is evaluated for each individual, the training of the RF model contains instances of all subjects (i.e., global training). We have validated the proposed global stress model using two open-access databases (the WESAD and SWELL databases) and their combination. The eight HRV features with the highest classifying power are selected using the minimum redundancy maximum relevance (mRMR) method, reducing the training time of the global stress platform. The proposed global stress monitoring model identifies person-specific stress events with an accuracy higher than 99% after a global training framework. Future work should be focused on testing this global stress monitoring framework in real-world applications.

Feasibility of Risk Factor-Based Screening for Posttraumatic Stress Disorder in Trauma.

BACKGROUND: Posttraumatic stress disorder (PTSD) following traumatic injury can have severe psychiatric consequences. Current recommendations from the American College of Surgeons Committee on Trauma require implementing PTSD screening but specify neither who should be screened nor how. It is unknown whether narrowed screening selection criteria could identify an acceptable proportion of patients with PTSD. OBJECTIVE: This study aimed to determine the feasibility of implementing risk factor-based PTSD screening in trauma patients by evaluating the sensitivity and clinical practicality. METHODS: This is a prospective diagnostic study of a consecutive series of general ward patients at an urban Level I trauma center from December 2021 to March 2022. Screening indications included (a) interpersonal injury, (b) surgery, (c) intracranial hemorrhage, (d) less than 30 years of age, or (e) clinical suspicion. The protocol was assessed by measuring the proportion of positive screens captured by only clinical suspicion to estimate sensitivity and by qualitatively evaluating barriers to implementation. RESULTS: Among the 200 patients screened, the number of patients who screened positive was 51 (25.5%). Eight patients were screened on clinical suspicion alone, seven (87.5%) of whom had positive screens, compared with 44 of the 192 (22.9%) patients who were screened for indications. Thus, 7 of 51 (13.7%; 95% confidence interval: 6.8%-26.7%) patients with PTSD-level symptoms would not have been screened on the basis of their risk factors. There were also practical difficulties in implementation. CONCLUSION: Limiting PTSD screening to only those injured patients with additional risk factors would have reduced overall sensitivity at our center. Consequently, we have implemented universal screening instead.

Low sensitivity of the COVID-19 antigen test (PANBIO™ COVID-19 Ag rapid test) to detect asymptomatic infections in health personnel of the National Institute of Respiratory Diseases.

Background: COVID-19 requires an early diagnosis to optimize management and limit transmission. SARS-CoV-2 is able to spread effectively. Infected asymptomatic individuals have been found to be contagious. RT-qPCR is the currently recommended laboratory method for diagnosing acute infection. However, rapid antigen detection (RAD) tests are not only fast, but require less specialized training. The possibility of using RAD tests to identify asymptomatic patients is attractive, as it could effectively contribute to minimizing the hospital spread of SARS-CoV-2. The objective of the study was to determine the performance of RAD vs. RT-qPCR for the detection of asymptomatic cases in INER health personnel. Methods: In order to follow WHO guidelines, generalized tests, a test station for health care workers was implemented on demand. A rapid test was carried out and a second sample was taken to be processed by RT-qPCR. With the results of both tests we conducted a retrospective study. Sensitivity, specificity, positive predictive value, negative predictive value and negative likelihood ratios were calculated. Results: A total of 1640 RAD tests were performed in health care workers (mean age was 39, 69, 47% with a self-reported comorbidity). Participants provided 1,640 valid RAD/RT-qPCR test pairs with 2% testing positive via RT-qPCR. 12 RAD samples were positive for SARS-CoV-2. Overall sensitivity of the PANBIO ™ COVID-19 Ag Rapid Test test was 35.2%. Conclusions: RADs are not recommended for the detection of asymptomatic cases due to low performance.

Selection of Noninvasive Features in Wrist-Based Wearable Sensors to Predict Blood Glucose Concentrations Using Machine Learning Algorithms.

Glucose monitoring technologies allow users to monitor glycemic fluctuations (e.g., blood glucose levels). This is particularly important for individuals who have diabetes mellitus (DM). Traditional self-monitoring blood glucose (SMBG) devices require the user to prick their finger and extract a blood drop to measure the blood glucose based on chemical reactions with the blood. Unlike traditional glucometer devices, noninvasive continuous glucose monitoring (NICGM) devices aim to solve these issues by consistently monitoring users' blood glucose levels (BGLs) without invasively acquiring a sample. In this work, we investigated the feasibility of a novel approach to NICGM using multiple off-the-shelf wearable sensors and learning-based models (i.e., machine learning) to predict blood glucose. Two datasets were used for this study: (1) the OhioT1DM dataset, provided by the Ohio University; and (2) the UofM dataset, created by our research team. The UofM dataset consists of fourteen features provided by six sensors for studying possible relationships between glucose and noninvasive biometric measurements. Both datasets are passed through a machine learning (ML) pipeline that tests linear and nonlinear models to predict BGLs from the set of noninvasive features. The results of this pilot study show that the combination of fourteen noninvasive biometric measurements with ML algorithms could lead to accurate BGL predictions within the clinical range; however, a larger dataset is required to make conclusions about the feasibility of this approach.

Long-term functional outcomes after traumatic spine fractures.

BACKGROUND: Traumatic spine fractures can result in chronic pain, disability, and prolonged rehabilitation. The purpose of this study is to determine the long-term effects of traumatic spine fractures on patients' functional outcomes after nonoperative and operative management. METHODS: Patients with traumatic spine fractures over a 5-year period were identified and stratified by management strategy (nonoperative and operative) and compared. Functional outcomes were measured using the Boston Activity Measure for PostAcute Care to assess basic mobility and daily activity. Multiple linear regression was used to identify predictors of functional outcome after traumatic spine fractures. RESULTS: In total, 488 patients were identified: 271 nonoperative and 217 operative. Follow-up was obtained in 168 (34%) patients: 95 nonoperative and 73 operative. Mean follow-up was 5.7 years (range 3-8 years). Mean Activity Measure for PostAcute Care scores in patients managed nonoperatively for basic mobility (68 vs 64, P = .09) and daily activity (69 vs 66, P = .26) were clinically similar to those managed operatively. Multiple linear regression identified increasing age as a predictor of decreased basic mobility (ß = -0.50, P < .0001, ß = -0.17, P = .022) and daily activity (ß = -0.58, P < .0001, ß = -0.35, P = .003) in nonoperative and operative groups, respectively. In nonoperative patients, thoracic spine fracture was predictive of both decreased basic mobility (ß = -5.88, P = .041) and daily activity (ß = -8.62, P = .043). In operative patients, lower extremity fractures (ß = -8.86, P = .012), discharge location (ß = -6.91, P = .003), and time to operative fixation (ß = -0.77, P = .040) were associated with decreased basic mobility. CONCLUSION: All patients with traumatic spine fractures displayed mild to moderate functional impairment. Age, thoracic fractures, lower extremity fractures, discharge location, and time to operative fixation were associated with poor functional outcomes.

Allogeneic hematopoietic stem cell transplant for sickle cell disease: The why, who, and what.

Allogeneic hematopoietic stem cell transplants (allo-HSCTs) from matched-related donors (MRDs), mismatched-related donors (MMRDs), and matched-unrelated donors (MUDs) are increasingly being used to treat sickle cell disease (SCD) in both pediatric and adult patients. The overall results have been extremely encouraging, especially if a MRD is available and the transplant being performed before the age of 13. Although there is a general consensus that patients with high-risk SCD, even in adults and irrespective of donor characteristics, should be offered allo-HSCT, the debates on optimal patient selection and timing of transplant have yet to be resolved. Unlike patients with hematologic malignancies, there are also a number of clinical issues that require to be addressed in patients with SCD undergoing allo-HSCT. In this review, we will discuss the reasons allo-HSCT should be offered more widely to patients with SCD, the challenges facing physicians in patient selection and timing of transplant, and the awareness of and solutions to prevent the complications that are unique or more common in SCD undergoing allo-HSCT.

Rapid-Onset Obesity Due to Impulsive Food-Seeking Behavior in a Puerto Rican Child With CHRNA7 15q13.3 Microdeletion.

A microdeletion in the 15q13.3 locus is an exceedingly rare condition affecting the CHRNA7 gene. There have been 11 pediatric cases of this mutation reported worldwide. Clinical characteristics of the 15q13.3 microdeletion are rapid-onset obesity, hypotonia, autism, seizures, congenital cardiac defects, and neuropsychiatric disorders including impulsive hyperphagia. We describe the case of a four-year-old female with CHRNA7 15q13.3 microdeletion presenting with morbid obesity due to impulsive food-seeking behavior. We have also conducted a literature review on 15q13.3 microdeletion and compared the clinical features with other rapid-onset obesity disorders in the pediatric population. The goal of this case report is to increase awareness concerning CHRNA7 15q13.3 microdeletion as part of the differential diagnosis of rapid-onset obesity associated with neuropsychiatric disorders in pediatrics.

Subconjunctival Acute Bilateral Hemorrhages Due to Kawasaki Disease in a Costa Rican Girl: An Unusual Clinical Manifestation of the Disease.

Kawasaki disease is an acute systemic vasculitis and is the leading cause of acquired cardiac disease in children. Among the ocular manifestations in these patients, bilateral non-suppurative conjunctival injection and uveitis are the most common. We describe a six-year-old Costa Rican girl with acute Kawasaki disease who developed severe bilateral conjunctival injection with subsequent bilateral subconjunctival hemorrhages. For her ocular involvement, she was treated expectantly, and after six weeks there was complete resolution. To our knowledge, this is the first report from Latin America and among the few in the literature of a child in whom severe bilateral subconjunctival hemorrhages occur as a manifestation of Kawasaki disease.

Advantages of Fresnel biprism-based digital holographic microscopy in quantitative phase imaging.

SIGNIFICANCE: The hallmarks of digital holographic microscopy (DHM) compared with other quantitative phase imaging (QPI) methods are high speed, accuracy, spatial resolution, temporal stability, and polarization-sensitivity (PS) capability. The above features make DHM suitable for real-time quantitative PS phase imaging in a broad number of biological applications aimed at understanding cell growth and dynamic changes occurring during physiological processes and/or in response to pharmaceutical agents. AIM: The insertion of a Fresnel biprism (FB) in the image space of a light microscope potentially turns any commercial system into a DHM system enabling QPI with the five desired features in QPI simultaneously: high temporal sensitivity, high speed, high accuracy, high spatial resolution, and PS. To the best of our knowledge, this is the first FB-based DHM system providing these five features all together. APPROACH: The performance of the proposed system was calibrated with a benchmark phase object. The PS capability has been verified by imaging human U87 glioblastoma cells. RESULTS: The proposed FB-based DHM system provides accurate phase images with high spatial resolution. The temporal stability of our system is in the order of a few nanometers, enabling live-cell studies. Finally, the distinctive behavior of the cells at different polarization angles (e.g., PS capability) can be observed with our system. CONCLUSIONS: We have presented a method to turn any commercial light microscope with monochromatic illumination into a PS QPI system. The proposed system provides accurate quantitative PS phase images in a new, simple, compact, and cost-effective format, thanks to the low cost (a few hundred dollars) involved in implementing this simple architecture, enabling the use of this QPI technique accessible to most laboratories with standard light microscopes.

Dissecting the Financial Relationship Between Industry and Academic Neurosurgery.

BACKGROUND: Established by the Centers for Medicare and Medicaid Services (CMS), the Open Payments Database (OPD) has reported industry payments to physicians since August 2013. OBJECTIVE: To evaluate the frequency, type, and value of payments received by academic neurosurgeons in the United States over a 5-yr period (2014-2018). METHODS: The OPD was queried for attending neurosurgeons from all neurosurgical training programs in the United States (n = 116). Information from the OPD was analyzed for the entire cohort as well as for comparative subgroup analyses, such as career stage, subspecialty, and geographic location. RESULTS: Of all identified neurosurgeons, 1509 (95.0%) received some payment from industry between 2014 and 2018 for a total of 106 171 payments totaling $266 407 458.33. A bimodal distribution was observed for payment number and total value: 0 to 9 (n = 438) vs > 50 (n = 563) and 0-$1000 (n = 418) vs >$10 000 (n = 653), respectively. Royalty/License was the most common type of payment overall (59.6%; $158 723 550.57). The median number (40) and value ($8958.95) of payments were highest for mid-career surgeons. The South-Central region received the most money ($117 970 036.39) while New England received the greatest number of payments (29 423). Spine surgeons had the greatest median number (60) and dollar value ($20 551.27) of payments, while pediatric neurosurgeons received the least (8; $1108.29). Male neurosurgeons received a greater number (31) and value ($6395.80) of payments than their female counterparts (11, $1643.72). CONCLUSION: From 2014 to 2018, payments to academic neurosurgeons have increased in number and value. Dollars received were dependent on geography, career stage, subspecialty and gender.

Innovation, Royalties, and Introduction of the Patent Hirsch Index within U.S. Academic Neurosurgery.

BACKGROUND: Historically, practicing neurosurgeons have been key drivers of neurosurgical innovation. We sought to describe the patents held by U.S. academic neurosurgeons and to explore the relationship between patents and royalties received. METHODS: The Centers for Medicare and Medicaid CMS Open Payments Data was used to identify academic neurosurgeons who had received royalties and royalty amounts during a 5-year period (2013-2017). Online patent databases were used to gather patent details. Patent citations and 5-year individual and departmental patent Hirsch (h)-indexes were calculated. Royalties were correlated with the number of patents, patent citations, and patent h-index. RESULTS: We found that 119 academic neurosurgeons (7.8%) from 57 U.S. teaching programs (48.3%) had received royalty payments; 72 (60.5%) had published 648 patents. All surgeons were men, with approximately one half in the "late" stages of their career (45.3%) and subspecializing in spinal surgery (50.4%). The patented products or devices were most commonly used for spinal surgery (72.1%), with 2010-2019 the most productive period (n = 455; 70.2%). The median number of citations per patent was 32 (range, 0-620), with 33% having ≥100 citations. The highest individual and institutional patent h-index was 95; 25 (34.7%) neurosurgeons had a patent h-index of ≥5. The median total royalty payment per individual neurosurgeon was $111,011 (range, $58.05-$76,715,750.34). Royalties were correlated with the number of patents (Spearman r = 0.37; P ≤ 0.001), citations (Spearman r, 0.38; P ≤ 0.001), and inventor h-index (Spearman r = 0.38; P ≤ 0.001). CONCLUSIONS: Few U.S. academic neurosurgeons (7.8%) receive royalties and hold patents (4.7%), with an even smaller select group having a patent h-index of ≥5 (1.6%).

Sleep characteristics of the parents of children admitted to a pediatric intensive care unit: risk factors and repercussion on their daily life activities.

OBJECTIVE: to analyze the sleep characteristics of the parents of children admitted to a pediatric intensive care unit (PICU), the possible risk factors and impact of sleep quality on their daily life activities. METHODS: Parents of children admitted to PICU for at least 48 h filled in a survey. Demographic data, sleep characteristics before and during admission and its impact on daily life activities measured by the FOSQ-10 questionnaire, were collected. RESULTS: 100 surveys from parents of 53 children admitted to the PICU were collected. Most children (74%) were cardiac patients. 55% of them had had previous PICU admissions. 45% of parents lived in a different city. They spent a median of 14 h a day (IQR 12-16) at the hospital and 89.2% did not attend work. Parents had significantly worse subjective sleep quality (p = 0.001), less sleeping hours/day (p = 0.001), more difficulty falling asleep (p = 0.001) and more night arousals (p = 0.001) during PICU admission than before. 77% of parents also had a bad FOSQ-10 score. Perceived sleep quality and FOSQ-10 score had a good correlation (p = 0.00, Kappa 0.43). Significant risk factors were living in a different city (p = 0.03), programmed admissions (p = 0.001), previous PICU admissions (p = 0.001), prolonged PICU length of stay (p = 0.03) and longer distance from home (p = 0.03). CONCLUSIONS: Three quarters of the parents of children admitted to PICU suffer from sleep disorders, which negatively affects their personal lives. Perceived sleep quality had a good correlation with FOSQ-10 score. Institutional support is needed to optimize parents' resting conditions during their child's hospitalization.

How Boundaries Form: Linked Nonautonomous Feedback Loops Regulate Pattern Formation in Yeast Colonies.

Under conditions in which budding yeast form colonies and then undergo meiosis/sporulation, the resulting colonies are organized such that a sharply defined layer of meiotic cells overlays a layer of unsporulated cells termed "feeder cells." This differentiation pattern requires activation of both the Rlm1/cell-wall integrity pathway and the Rim101/alkaline-response pathway. In the current study, we analyzed the connection between these two signaling pathways in regulating colony development by determining expression patterns and cell-autonomy relationships. We present evidence that two parallel cell-nonautonomous positive-feedback loops are active in colony patterning, an Rlm1-Slt2 loop active in feeder cells and an Rim101-Ime1 loop active in meiotic cells. The Rlm1-Slt2 loop is expressed first and subsequently activates the Rim101-Ime1 loop through a cell-nonautonomous mechanism. Once activated, each feedback loop activates the cell fate specific to its colony region. At the same time, cell-autonomous mechanisms inhibit ectopic fates within these regions. In addition, once the second loop is active, it represses the first loop through a cell-nonautonomous mechanism. Linked cell-nonautonomous positive-feedback loops, by amplifying small differences in microenvironments, may be a general mechanism for pattern formation in yeast and other organisms.

Postgraduate publishing output in pediatric neurosurgery: correlation with fellowship site and individual scholars.

OBJECTIVE: The objective of this study was to analyze the publication output of postgraduate pediatric neurosurgery fellows for a 10-year period as well as identify 25 individual highly productive pediatric neurosurgeons. The correlation between academic productivity and the site of fellowship training was studied. METHODS: Programs certified by the Accreditation Council for Pediatric Neurosurgery Fellowships that had 5 or more graduating fellows from 2006 to 2015 were included for analysis. Fellows were queried using Scopus for publications during those 10 years with citation data through 2017. Pearson correlation coefficients were calculated, comparing program rankings of faculty against fellows using the revised Hirsch index (r-index; primary) and Hirsch index (h-index; secondary). A list of 25 highly accomplished individual academicians and their fellowship training locations was compiled. RESULTS: Sixteen programs qualified with 152 fellows from 2006 to 2015; 136 of these surgeons published a total of 2009 articles with 23,735 citations. Most publications were pediatric-specific (66.7%) clinical articles (93.1%), with middle authorship (55%). Co-investigators were more likely from residency than fellowship. There was a clustering of the top 7 programs each having total publications of around 120 or greater, publications per fellow greater than 12, more than 1200 citations, and adjusted ir10 (revised 10-year institutional h-index) and ih10 (10-year institutional h-index) values of approximately 2 or higher. Correlating faculty and fellowship program rankings yielded correlation coefficients ranging from 0.53 to 0.80. Fifteen individuals (60%) in the top 25 (by r5 index) list completed their fellowship at 1 of these 7 institutions. CONCLUSIONS: Approximately 90% of fellowship-trained pediatric neurosurgeons have 1 or more publications, but the spectrum of output is broad. There is a strong correlation between where surgeons complete their fellowships and postgraduate publications.

A regioselective etherification of pyridoxine via an ortho-pyridinone methide intermediate.

The catalyst-free, regioselective synthesis of 4'-O-substituted pyridoxine derivatives under solventless conditions is described. The methodology relies on the highly regioselective formation of the ortho-pyridinone methide from pyridoxine and subsequent oxa-Michael addition of alcohol nucleophiles. This methodology provides good to excellent yields for primary and secondary alcohols and moderate yields for tertiary alcohols.

Community-wide evaluation of methods for predicting the effect of mutations on protein-protein interactions.

Community-wide blind prediction experiments such as CAPRI and CASP provide an objective measure of the current state of predictive methodology. Here we describe a community-wide assessment of methods to predict the effects of mutations on protein-protein interactions. Twenty-two groups predicted the effects of comprehensive saturation mutagenesis for two designed influenza hemagglutinin binders and the results were compared with experimental yeast display enrichment data obtained using deep sequencing. The most successful methods explicitly considered the effects of mutation on monomer stability in addition to binding affinity, carried out explicit side-chain sampling and backbone relaxation, evaluated packing, electrostatic, and solvation effects, and correctly identified around a third of the beneficial mutations. Much room for improvement remains for even the best techniques, and large-scale fitness landscapes should continue to provide an excellent test bed for continued evaluation of both existing and new prediction methodologies.