SCRATCH: A programmable, open-hardware, benchtop robot that automatically scratches cultured tissues to investigate cell migration, healing, and tissue sculpting.

Despite the widespread popularity of the ' scratch assay', where a pipette is dragged through cultured tissue to create an injury gap to study cell migration and healing, the manual nature of the assay carries significant drawbacks. So much of the process depends on individual manual technique, which can complicate quantification, reduce throughput, and limit the versatility and reproducibility of the approach. Here, we present a truly open-source, low-cost, accessible, and robotic scratching platform that addresses all of the core issues. Compatible with nearly all standard cell culture dishes and usable directly in a sterile culture hood, our robot makes highly reproducible scratches in a variety of complex cultured tissues with high throughput. Moreover, we demonstrate how scratching can be programmed to precisely remove areas of tissue to sculpt arbitrary tissue and wound shapes, as well as enable truly complex co-culture experiments. This system significantly improves the usefulness of the conventional scratch assay, and opens up new possibilities in complex tissue engineering and cell biological assays for realistic wound healing and migration research.

Determining the Degree of Sulfo-tag Conjugation to AAV5 Vectors by LC-HRMS and Evaluating the Effects on Antibody Binding Affinity and Bridging Assay Sensitivity.

Pre-existing anti-AAV antibodies can be detected using ligand binding-based assay formats. One such format is the MSD-based bridging assay, which uses sulfo-tag-labeled AAV vectors as detection reagents. However, no method has been developed to accurately measure the degree of sulfo-tag labeling on AAV vectors. To fill this gap, we developed a liquid chromatography-high resolution mass spectrometry (LC-HRMS) method to assess the degree of labeling (DoL) of sulfo-tag on AAV5 vectors, enabling the measurement of the DoL on AAV5 at six increasing levels of sulfo-tag challenge ratio. In addition, a Biacore-based assay was used to evaluate the binding affinity between an anti-AAV5 monoclonal antibody and various sulfo-tag labeled AAV5 vectors. The results indicated that increased DoL of sulfo-tag labeling on AAV5 did not compromise the binding affinity.Our study further employed the MSD-bridging assay to detect the binding Signal/Noise (S/N) ratios of four anti-AAV5 monoclonal antibodies (mAbs) to various sulfo-tag-labeled AAV5 vectors. The findings revealed a strong correlation between the degree of sulfo-tag labeling and both the S/N ratios and the sensitivity of MSD bridging assays. This result underscores the importance of optimizing the labeling of detection reagents to enhance assay sensitivity for detecting anti-AAV5 antibodies.

Practice variation in the management of pediatric intussusception: a narrative review.

Ileocolic intussusception, a major cause of acute intestinal obstruction in young children, necessitates rapid diagnosis and a multidisciplinary treatment approach. A recent large study identified variations in pain management, sedation, and non-operative reduction methods in these patients. We aimed to explore variability within the diagnostic and treatment pathways of ileocolic intussusception. A narrative review of the literature was conducted for peer-reviewed articles published in English between 2004 and 2024. We searched the electronic databases Ovid, Embase, Scopus, PubMed, and the Cochrane Database. Google Scholar was searched using the search terms "intussusception," "triage," "diagnosis," emergency department," "radiology," "ultrasound," "POCUS," "reduction," "air-enema," "fluid-enema," "pneumatic," "hydrostatic," "pain," "sedation," "operating-room," "laparoscopy," and "surgery" to identify articles published in electronic journals, books, and scientific websites. Data were analyzed by a multidisciplinary team of specialists in pediatric emergency medicine, pediatric radiology, and pediatric surgery. Fifty-six papers were included in this review. Six areas of practice variation were found: pain management in triage, the use of point-of-care ultrasound in the emergency department, the use of pneumatic versus hydrostatic technique for the reduction procedure, performing the reduction procedure under sedation, patient observation after an uncomplicated reduction, and the use of open surgery or laparoscopy for patients who underwent unsuccessful reduction. CONCLUSION: This review has identified practice variations in several key areas of ileocolic intussusception management. The findings underscore the need for further research in these areas and the establishment of uniform standards aimed at improving the care of children with ileocolic intussusception. WHAT IS KNOWN: • Ileocolic intussusception necessitates rapid diagnosis and a collaborative treatment approach involving emergency medicine, radiology, surgery, and often anesthesia. • A previous study reported variations in the practice of pain management and sedation among these patients. WHAT IS NEW: • This narrative review identified practice variations in several key areas within the diagnostic and treatment pathways of ileocolic intussusception.

Evaluation of Acute Terminal Ileitis in Hospitalized Patients: Development of a Predictive Model to Distinguish Crohn's Disease from Other Etiologies.

Background/Objectives: Terminal ileitis (TI) is often identified on CT scans in emergency settings. Diagnosing Crohn's disease (CD) as a cause of TI is crucial due to its significant long-term implications. This study aimed to differentiate CD from other causes of acute TI and develop a predictive model for CD diagnosis. Methods: A retrospective case-control study was conducted at Shamir Medical Center including adults diagnosed with acute TI from January 2012 to December 2020. Patients with a history of inflammatory bowel disease or prior intestinal surgery were excluded. Patients were categorized into CD and non-CD groups based on their subsequent clinical course. A logistic regression model was developed and subsequently validated with additional patients hospitalized between 2021 and 2023. Results: Among 135 patients, 37 (27.4%) were diagnosed with CD. CD patients were younger (median age 27 vs. 39 years, p = 0.003), predominantly male (83.8% vs. 51%, p = 0.001), and had higher rates of chronic abdominal pain, diarrhea, anemia, and weight loss prior to hospitalization. Significant laboratory differences included higher platelet counts (p = 0.006) and lower mean corpuscular volume (MCV) (p = 0.001) in CD patients. Radiologic signs of complicated disease were more common in CD (35.1% vs. 4.1%, p < 0.001). The predictive model incorporating gender, abdominal pain history, and MCV showed an area under the curve (AUC) of 0.87, with a sensitivity of 100% and specificity of 63.6% in the validation group of 18 patients. Conclusions: This study identified key predictors of CD in patients presenting with acute TI and developed a predictive model with a substantial diagnostic capability. Use of this model for early identification and treatment of CD may potentially improve patient outcomes. Further prospective validation of this model is warranted.

Epidemiology and risk factors for angiodysplasias of the upper and lower gastrointestinal tract: A large population-based study.

BACKGROUND: Gastrointestinal angiodysplasia (GIAD) is a rare diagnosis among the general population. We aimed to identify risk factors for GIADs and to determine the frequency rate in the general population. METHODS: A population-based retrospective study was performed including patients diagnosed with upper (stomach/duodenum) or lower (small bowel/colon) GIADs based on diagnostic codes from a large health maintenance organization. Control groups were matched for age and gender. Additional data including demographics, comorbidities, malignancies, and medications were collected. RESULTS: 991 upper GIADs and 3336 lower GIADs were included, compared to 7217 and 32,802 controls. The overall prevalence of GIAD was 0.092 %. 88 % of the upper and 85 % of the lower GIADs were diagnosed at ages ≥60, peaking at a prevalence of 0.37 % for ages 71-80. The most significant risk factors for GIADs included liver cirrhosis (OR 4.0 for lower GIAD and OR 7.0 for upper GIAD, p < 0.001), hypertension (OR 2.3 for lower GIAD and OR 2.8 for upper GIAD, p < 0.001) and aortic stenosis (OR 2.8 for lower GIAD and OR 2.0 for upper GIAD, p < 0.001). Other significant risk factors included ischemic heart disease, chronic renal failure, female gender, and chronic obstructive pulmonary disease. Interestingly, both upper and lower GIADs were found to be significantly less frequent in patients with malignancy. CONCLUSION: Identification of the clinical conditions and demographic factors associated with GIAD may improve our understanding of the etiology and the optimal treatment modalities for this rare condition.

Building Biomaterials to Mimic 3D Cell-Cell Junctions.

Cell-cell interactions typically occur in a 3D context that is distinct from conventional 2D cell-substrate interactions in a Petri dish. Here, we describe a benchtop method to combine a 2D extracellular matrix surface with a 3D, vertical boundary functionalized with the extracellular domain of E-cadherin. The methodology is suitable for any biology laboratory without requiring advanced microfabrication equipment or training. Overall, this cell-mimetic interface uniquely recapitulates key aspects of cell-cell adhesion and can serve as a versatile, reductionist technique to study general cell-cell interactions in a 3D context.

Novel measures of cognition and function for the AD spectrum in the Novel Measures for Alzheimer's Disease Prevention Trials (NoMAD) project: Psychometric properties, convergent validation, and contrasts with established measures.

INTRODUCTION: This study derived composite scores for two novel cognitive measures, the No Practice Effect (NPE) battery and the Miami Computerized Functional Skills Assessment and Training system for use in early-stage Alzheimer's disease (AD) clinical trials. Their psychometric properties and associations with AD risk markers were compared to those of well-established measures. METHODS: For 291 older adults with healthy cognition or early mild cognitive impairment, Exploratory factor analyses were used to identify the factor structure of the NPE. Factor and total scores were examined for their psychometric properties and associations with AD risk biomarkers. RESULTS: Composite scores from the novel cognitive and functional measures demonstrated better psychometric properties (distribution and test-retest reliability) and stronger associations with AD-related demographic, genetic, and brain risk markers than well-established measures, DISCUSSION: These novel measures have potential for use as primary cognitive and functional outcomes in early-stage AD clinical trials. HIGHLIGHTS: Well-established cognitive tests may not accurately detect subtle cognitive changes. No Practice Effect (NPE) and Computerized Functional Skills Assessment and Training are novel measures designed to have improved psychometric properties. NPE had Executive Function, Cognitive Control/Speed, and Episodic Memory domains. Novel measures had better psychometric properties compared to established measures. Significant associations with Alzheimer's disease biomarkers were found with novel measures.

III-nitride m-plane violet narrow ridge edge-emitting laser diodes with sidewall passivation using atomic layer deposition.

A novel deep-ridge laser structure with atomic-layer deposition (ALD) sidewall passivation was proposed that enhances the optical characteristics of 8-µm ridge width III-nitride violet lasers on freestanding m-plane GaN substrates. The internal loss was determined using the variable stripe length method, where the laser structure with ALD sidewall passivation showed lower internal loss compared to the conventional shallow-ridge laser design. ALD sidewall passivation plays a critical role in device improvements; compared to the lasers without ALD sidewall passivation, the lasers with ALD sidewall passivation yield improved optoelectrical performance and longer lifetime under continuous-wave operation at high current density. This work demonstrates the importance of ALD sidewall passivation to laser performance, which enables high energy efficiency.

Large-scale control over collective cell migration using light-controlled epidermal growth factor receptors.

Receptor tyrosine kinases (RTKs) are thought to play key roles in coordinating cell movement at single-cell and tissue scales. The recent development of optogenetic tools for controlling RTKs and their downstream signaling pathways suggested these responses may be amenable to engineering-based control for sculpting tissue shape and function. Here, we report that a light-controlled EGF receptor (OptoEGFR) can be deployed in epithelial cell lines for precise, programmable control of long-range tissue movements. We show that in OptoEGFR-expressing tissues, light can drive millimeter-scale cell rearrangements to densify interior regions or produce rapid outgrowth at tissue edges. Light-controlled tissue movements are driven primarily by PI 3-kinase signaling, rather than diffusible signals, tissue contractility, or ERK kinase signaling as seen in other RTK-driven migration contexts. Our study suggests that synthetic, light-controlled RTKs could serve as a powerful platform for controlling cell positions and densities for diverse applications including wound healing and tissue morphogenesis.

Optimal Control of Collective Electrotaxis in Epithelial Monolayers.

Epithelial monolayers are some of the best-studied models for collective cell migration due to their abundance in multicellular systems and their tractability. Experimentally, the collective migration of epithelial monolayers can be robustly steered e.g. using electric fields, via a process termed electrotaxis. Theoretically, however, the question of how to design an electric field to achieve a desired spatiotemporal movement pattern is underexplored. In this work, we construct and calibrate an ordinary differential equation model to predict the average velocity of the centre of mass of a cellular monolayer in response to stimulation with an electric field. We use this model, in conjunction with optimal control theory, to derive physically realistic optimal electric field designs to achieve a variety of aims, including maximising the total distance travelled by the monolayer, maximising the monolayer velocity, and keeping the monolayer velocity constant during stimulation. Together, this work is the first to present a unified framework for optimal control of collective monolayer electrotaxis and provides a blueprint to optimally steer collective migration using other external cues.

Ankle mechanics during jump landings across different foot positions in professional ballet dancers.

This study aimed to investigate the effect foot position on ankle joint mechanics and vertical ground reaction forces (vGRF) across jump landings in professional ballet dancers. Twenty-seven professional ballet dancers (men: 14; women: 13) attended one data collection session, completing five maximal countermovement jumps in parallel, first, second, fourth, and fifth positions. Three-dimensional ankle mechanics, landing vGRF variables, and jump height were recorded via a seven-camera motion capture system and one force platform. A repeated measures multivariate analysis of variance was used to assess the main effects foot position across all target variables. A linear discriminate analysis was conducted to investigate target variables across foot positions. Frontal and transverse plane ankle mechanics had the largest impact when discriminating between foot positions. Ankle power in the transverse plane during jump landing in fourth was double that of all other positions. Our findings suggest that ankle range of motion should be restored before returning to jumps in fourth and fifth positions following distal lower extremity injury. The multiplanar energy transfer observed indicates a need for specific exercises to develop multiplanar force and rate of force development of local structures around the ankle.

Quantifying cell cycle regulation by tissue crowding.

The spatiotemporal coordination and regulation of cell proliferation is fundamental in many aspects of development and tissue maintenance. Cells have the ability to adapt their division rates in response to mechanical constraints, yet we do not fully understand how cell proliferation regulation impacts cell migration phenomena. Here, we present a minimal continuum model of cell migration with cell cycle dynamics, which includes density-dependent effects and hence can account for cell proliferation regulation. By combining minimal mathematical modeling, Bayesian inference, and recent experimental data, we quantify the impact of tissue crowding across different cell cycle stages in epithelial tissue expansion experiments. Our model suggests that cells sense local density and adapt cell cycle progression in response, during G1 and the combined S/G2/M phases, providing an explicit relationship between each cell-cycle-stage duration and local tissue density, which is consistent with several experimental observations. Finally, we compare our mathematical model's predictions to different experiments studying cell cycle regulation and present a quantitative analysis on the impact of density-dependent regulation on cell migration patterns. Our work presents a systematic approach for investigating and analyzing cell cycle data, providing mechanistic insights into how individual cells regulate proliferation, based on population-based experimental measurements.

Hematuria Cancer Risk Score with Ultrasound Informs Cystoscopy Use in Patients with Hematuria.

BACKGROUND: Hematuria is a cardinal symptom of urinary tract cancer and would require further investigations. OBJECTIVE: To determine the ability of renal bladder ultrasound (RBUS) with the Hematuria Cancer Risk Score (HCRS) to inform cystoscopy use in patients with hematuria. DESIGN, SETTING, AND PARTICIPANTS: The development cohort comprised 1984 patients with hematuria from 40 UK hospitals (DETECT 1; ClinicalTrials.gov: NCT02676180) who received RBUS. An independent validation cohort comprised 500 consecutive patients referred to secondary care for a suspicion of bladder cancer. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Sensitivity and true negative of the HCRS and RBUS were assessed. RESULTS AND LIMITATIONS: A total of 134 (7%) and 36 (8%) patients in the development and validation cohorts, respectively, had a diagnosis of urinary tract cancer. Validation of the HCRS achieves good discrimination with an area under the receiver operating characteristic curve of 0.727 (95% confidence interval 0.648-0.800) in the validation cohort with sensitivity of 95% for the identification of cancer. Utilizing the cutoff of 4.500 derived from the HCRS in combination with RBUS in the development cohort, 680 (34%) patients would have been spared cystoscopy at the cost of missing a G1 Ta bladder cancer and a urinary tract cancer patient, while 117 (25%) patients would have avoided cystoscopy at the cost of missing a single patient of G1 Ta bladder cancer with sensitivity for the identification of cancer of 97% in the validation cohort. CONCLUSIONS: The HCRS with RBUS offers good discriminatory ability in identifying patients who would benefit from cystoscopy, sparing selected patient cohorts from an invasive procedure. PATIENT SUMMARY: The hematuria cancer risk score with renal bladder ultrasound allows for the triage of patients with hematuria who would benefit from visual examination of the bladder (cystoscopy). This resulted in 25% of patients safely omitting cystoscopy, which is an invasive procedure, and would lead to health care cost savings.

Complications and survival rates of subtrochanteric fractures are similar between short and long intramedullary nail fixation and independent of weight-bearing.

PURPOSE: Intertrochanteric fractures are treated surgically, allowing rapid weight-bearing to improve ambulation and lower complications and mortality. Subtrochanteric fractures are mechanically less stable and are traditionally treated with a non-weight approach and longer intramedullary nails. This study compared immediate weight-bearing versus limited weight-bearing and different intramedullary nail lengths regarding patient outcomes. METHODS: We analyzed all consecutive cases of low-energy subtrochanteric fractures treated surgically at our institution between January 2016 and November 2020. One hundred and nine patients were found. We compared nail length and immediate versus delayed weight-bearing concerning the length of stay, time to painless ambulation, time to radiographic fracture union, and revision rates. Fracture severity was also examined using the Seinsheimer classification. RESULTS: Length of stay and time to painless ambulation were shorter in the immediate weight-bearing group. Time to radiographic union and rate of complications were lower; however, they were not statistically significant. Conversely, no significant difference in revision rates was found. Regarding nail length, the length of stay was shorter, and the time to painless ambulation was faster in the short-length group. The rate of complications and time to union were similar. No difference in revision rate was found. Seinsheimer classification of the fracture did not influence the decision to allow weight-bearing or nail selection (p = 0.65). CONCLUSIONS: This study demonstrates that immediate weight-bearing as tolerated and short intramedullary nails allow a quicker time for painless ambulation and hospitalization, with possibly fewer perioperative complications and faster radiographic union, without increasing complications.

Sleep-wake behavior, perceived fatigability, and cognitive reserve in older adults.

INTRODUCTION: The effects of sleep-wake behavior on perceived fatigability and cognitive abilities when performing daily activities have not been investigated across levels of cognitive reserve (CR). METHODS: CR Index Questionnaire (CRIq) data were collected and subjected to moderated mediation analysis. RESULTS: In amnestic mild cognitive impairment (aMCI; n = 41), CR moderated sleep-related impairments (SRIs), and fatigability at low CR (CRIq < 105.8, p = 0.004) and mean CR (CRIq = 126.9, p = 0.03) but not high CR (CRIq > 145.9, p = 0.65) levels. SRI affected cognitive abilities mediated by fatigability at low CR (p < 0.001) and mean CR (p = 0.003) levels. In healthy controls (n = 13), SRI in fatigability did not alter cognitive abilities across CR levels; controls had higher leisure scores than patients with aMCI (p = 0.003, effect size = 0.93). DISCUSSION: SRI can amplify impaired cognitive abilities through exacerbation of fatigability in patients with aMCI with below-mean CR. Therefore, improving sleep-wake regulation and leisure activities may protect against fatigability and cognitive decline. HIGHLIGHTS: Clinical fatigue and fatigability cannot be alleviated by rest. Clinical fatigability disrupts daily activities during preclinical Alzheimer's. High cognitive reserve mitigates sleep-wake disturbance effects. High cognitive reserve attenuates clinical fatigability effects on daily functioning. Untreated obstructive sleep apnea potentiates Alzheimer's pathology in the brain.

Etiologies of bloody diarrhea in children presenting with acute gastroenteritis to US emergency departments.

Among 111 children presenting with bloody diarrhea in a multicenter study of molecular testing in US emergency departments, we found viral pathogens in 18%, bacteria in 48%, protozoa in 2%, and no pathogens detected in 38%.

The association of range of motion, lower limb strength, and load during jump landings in professional ballet dancers.

This study aimed to investigate the associations between peak plantarflexion ankle joint moments and vertical ground reaction forces (vGRF) during jump landings, and static ankle dorsiflexion range of motion (ROM), three-dimensional ankle excursions, and lower extremity strength in professional ballet dancers. Twenty-seven professional ballet dancers volunteered to participate (men = 14, women = 13). Participants attended one data collection session to measure dorsiflexion ROM and isometric lower extremity strength. Two further sessions were used to establish ankle mechanics and vGRFs during countermovement jump landings in seven foot positions, via a seven-camera motion capture system and piezoelectric force platform. Two linear mixed-effects models were used to investigate associations between the target variables and strength, dorsiflexion ROM, and ankle excursions. Dancer identification, sex, and foot position were entered as random effects. Model fit, when considered independent of random effects, was generally poor with the predictor variables explaining little of the variance of peak plantarflexion ankle joint moments (R2 = 0.02) or vGRF (R2 = 0.01). Model fit improved when random effects were considered (R2 = 0.65 & 0.34). Frontal plane ankle excursion was the only predictor variable with a significant negative association with peak plantarflexion ankle joint moments (p = .016), although coefficient estimates were small. Strength, static ankle dorsiflexion ROM, and three-dimensional ankle excursions are poor predictors of load experienced at a joint and system level in professional ballet dancers. Differences between individuals, sex, and foot position may be better indicators of the load experienced during jump landings.

Bioelectric stimulation controls tissue shape and size.

Epithelial tissues sheath organs and electro-mechanically regulate ion and water transport to regulate development, homeostasis, and hydrostatic organ pressure. Here, we demonstrate how external electrical stimulation allows us to control these processes in living tissues. Specifically, we electrically stimulate hollow, 3D kidneyoids and gut organoids and find that physiological-strength electrical stimulation of ∼ 5 - 10 V/cm powerfully inflates hollow tissues; a process we call electro-inflation. Electro-inflation is mediated by increased ion flux through ion channels/transporters and triggers subsequent osmotic water flow into the lumen, generating hydrostatic pressure that competes against cytoskeletal tension. Our computational studies suggest that electro-inflation is strongly driven by field-induced ion crowding on the outer surface of the tissue. Electrically stimulated tissues also break symmetry in 3D resulting from electrotaxis and affecting tissue shape. The ability of electrical cues to regulate tissue size and shape emphasizes the role and importance of the electrical micro-environment for living tissues.

Switching from Intravenous to Subcutaneous Biological Therapy for Inflammatory Bowel Disease Patients Remains a Challenge.

Biological inflammatory bowel disease (IBD) medications, once limited to intravenous (IV) administration, can now be administered both via IV and subcutaneously (SC). This study investigates patient preferences, willingness to switch from IV to SC, and associated factors. A questionnaire covering demographics, disease-related inquiries, quality of life, and IBD medication preferences was distributed via email, the Israeli Crohn's Disease and Ulcerative Colitis Foundation, infusion centers, and clinics. From 454 IBD patients (median age: 42 years; 55.7% female), responses revealed a preference for SC every 8 weeks, which is comparable to daily oral dosing. Both options were significantly favored over IV every 8 weeks and SC every 2 weeks, with no statistically significant differences between the latter two. However, among patients who were experienced with both SC and IV administration, a clear preference for SC administration every 2 weeks over IV every 8 weeks surfaced. Among IV-treated patients, 54.5% resisted switching to SC. Key reasons for this included medical staff presence (57.7%), a fear of needles (46.4%), belief in infusion efficacy (37.1%), and longer intervals between infusions (36.1%). Findings suggest that transitioning from IV to SC treatment is challenging due to patient resistance, which is influenced by specific factors. Identifying and addressing these obstacles is crucial for optimizing IBD management.