Bioengineering approaches for patient-specific analysis of placenta structure and function.

The leading cause of perinatal mortality is fetal growth restriction (FGR), defined as in utero fetal growth below the 10th percentile. Insufficient exchange of oxygen and nutrients at the maternal-fetal interface is associated with FGR. This transport occurs through the vasculature of the placenta, particularly in the terminal villi, where the vascular membranes have a large surface area and are the thinnest. Altered structure of the placenta villi is thought to contribute to decreased oxygen exchange efficiency, however, understanding how the three-dimensional microstructure and properties decrease this efficiency remains a challenge. Here, a novel, multiscale workflow is presented to quantify patient-specific biophysical properties, 3D structural features, and blood flow of the villous tissue. Namely, nanoindentation, optical coherence tomography, and ultrasound imaging were employed to measure the time-dependent material properties of placenta tissue, the 3D structure of villous tissue, and blood flow through the villi to characterize the microvasculature of the placenta at increasing length scales. Quantifying the biophysical properties, the 3D architecture, and blood flow in the villous tissue can be used to infer changes in maternal-fetal oxygen transport at the villous membrane. Overall, this multiscale understanding will advance knowledge of how microvascular changes in the placenta ultimately lead to FGR, opening opportunities for diagnosis and intervention.

Epigenetic regulation of p63 blocks squamous-to-neuroendocrine transdifferentiation in esophageal development and malignancy.

While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.

What Is the Optimal Stenting Duration After Ureteroscopy and Stone Intervention? Impact of Dwell Time on Postoperative Emergency Department Visits.

PURPOSE: AUA stone management guidelines recommend stenting duration following ureteroscopy be minimized to reduce morbidity; stents with extraction strings may be used for this purpose. However, an animal study demonstrated that short dwell time results in suboptimal ureteral dilation, and a pilot clinical study showed this increases postprocedure events. Using real-world practice data we examined stent dwell time after ureteroscopy and its association with postoperative emergency department visits. MATERIALS AND METHODS: We used the Michigan Urological Surgery Improvement Collaborative registry to identify ureteroscopy and stenting procedures (2016-2019). Pre-stented cases were excluded. Stenting cohorts with and without strings were analyzed. Using multivariable logistic regression we evaluated the risk of an emergency department visit occurring on the day of, or day after, stent removal based on dwell time and string status. RESULTS: We identified 4,437 procedures; 1,690 (38%) had a string. Median dwell time was lower in patients with a string (5 vs 9 days). Ureteroscopy in younger patients, smaller stones, or renal stone location had a higher frequency of string use. The predicted probability of an emergency department visit was significantly greater in procedures with string, compared to without string, when dwell times were less than 5 days (P < .01) but were not statistically significant after. CONCLUSIONS: Patients who had ureteroscopy and stenting with a string have short dwell times. Patients are at increased risk of a postoperative emergency department visit around the time of stent removal if dwell time is ≤4 days. We recommended stenting duration of at least 5 days in nonpre-stented patients.

The development and stem cells of the esophagus.

The esophagus is derived from the anterior portion of the foregut endoderm, which also gives rise to the respiratory system. As it develops, the esophageal lining is transformed from a simple columnar epithelium into a stratified squamous cell layer, accompanied by the replacement of unspecified mesenchyme with layers of muscle cells. Studies in animal models have provided significant insights into the roles of various signaling pathways in esophageal development. More recent studies using human pluripotent stem cells (hPSCs) further demonstrate that some of these signaling pathways are conserved in human esophageal development. In addition, a combination of mouse genetics and hPSC differentiation approaches have uncovered new players that control esophageal morphogenesis. In this Review, we summarize these new findings and discuss how the esophagus is established and matures throughout different stages, including its initial specification, respiratory-esophageal separation, epithelial morphogenesis and maintenance. We also discuss esophageal muscular development and enteric nervous system innervation, which are essential for esophageal structure and function.

Beware of the sneeze.

Switch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), also known as integrase interactor 1-deficient sinonasal carcinoma, is a rare entity that was first described in 2014. Since then, there have been 39 cases published in the literature, with basaloid or plasmacytoid/rhabdoid morphology being the most common pathological subtype. We report a patient with switch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (integrase interactor 1)-deficient sinonasal carcinoma who had permanent vision loss after valsalva-induced acute hemorrhage and resultant orbital compartment syndrome.

Analysis of Periorbital Soft Tissue in Thyroid Eye Disease.

PURPOSE: To investigate periorbital tissue enlargement in thyroid eye disease (TED) by 3-dimensional CT volumetric analysis. METHODS: Twenty-four adult subjects, 16 with TED and 8 controls, were studied. Three-dimensional volumetric calculations were performed on CT imaging of the orbit and face, focusing on the retroorbicularis oculi fat, suborbicularis oculi fat, facial muscles in periorbital region, orbital fat, extraocular muscles, and orbital volume. Analysis was performed using JMP version 12 software. Each measure was compared between the TED and control groups using Wilcoxon rank sum test. Correlations were investigated between periorbital and orbital tissue using the Spearman's correlation coefficient method. RESULTS: A statistically significant increase in volume was measured in TED patients in the superior and inferior periorbital fat tissue (p = 0.0044, p = 0.047), including the retroorbicularis oculi fat (p = 0.0011), suborbicularis oculi fat (p = 0.0093), and a decrease in facial muscle of superior periorbital region (p = 0.035). Strong positive correlation was noted between the muscles of superior and inferior periorbital region (rs = 0.65; p = 0.0006), and between the suborbicularis oculi fat and retroorbicularis oculi fat (rs = 0.50; p = 0.013). No correlation was observed between orbital and periorbital tissue, except between the orbital fat and the inferior periorbital fat tissue (p = 0.047). CONCLUSIONS: Facial fat in the periorbital region is enlarged in TED, with the superior component correlating with orbital fat tissue expansion. These findings may assist in the clinical evaluation and management of disfigurement in TED patients.Superior and inferior periorbital fat is enlarged in thyroid eye disease with the superior periorbital fat expansion correlating with orbital fat expansion.

Single Suture Müeller Muscle Conjunctival Resection (ssMMCR): A Modified Technique for Ptosis Repair.

PURPOSE: To evaluate the efficacy in degree of ptosis correction achieved by single suture Müeller muscle conjunctival resection (ssMMCR) when compared with that of traditional MMCR. METHODS: A retrospective chart analysis of patients who underwent either ssMMCR or traditional MMCR at 2 institutions. Single suture MMCR was performed after using a ptosis clamp to imbricate conjunctiva and Müeller muscle. Margin-to-reflex distance 1 was measured pre- and postoperatively, and the change in margin-to-reflex distance 1 was analyzed for both groups. Patients were monitored in follow up for postoperative complications including lagophthalmos, corneal abrasions, and change in visual acuity. Statistical analysis was performed using the Microsoft Excel and Stata software programs. RESULTS: Twenty-seven and 30 patients underwent single suture and traditional MMCR, respectively. The ssMMCR and MMCR groups were followed postoperatively for approximately 4.2 and 9.7 months, respectively and the average margin-to-reflex distance 1 increased by 2.93 mm and 2.81 mm, respectively. Notably, there was no statistically significant difference in the means identified by t test. Of the 94 eyelid surgeries evaluated, 1 ssMMCR and 3 MMCR eyelids required further surgical revision for persistent ptosis, and 1 ssMMCR developed a transient corneal epithelial abrasion. Surgical revisions were rare with both procedures, and patient satisfaction was high. CONCLUSIONS: Single suture MMCR is an efficient and effective method for ptosis repair. It results in comparable outcomes including elevation in margin-to-reflex distance 1, safety profile, and reoperation rates, when compared with traditional MMCR.

Accurate definition of control strategies using cross validated stepwise regression and Monte Carlo simulation.

Drug manufacturing processes must consistently deliver safe and effective product. A key part of achieving this is process validation utilizing Quality by Design (QbD) principles. To meet process validation requirements, process characterization (PC) studies are often performed to expand process understanding and establish an appropriate control strategy that enables the manufacturing process to consistently deliver a target product profile. Two key elements of the control strategy resulting from PC work are a list of critical process parameters (CPPs) and defined operating ranges (ORs). These are frequently derived based on mathematical models describing the relationship between process parameters and critical quality attributes (CQAs). Risk assessment and design of experiments (DOE) techniques are effectively deployed in the industry to identify parameters to study and build process understanding. However, traditional data analysis techniques do not fully utilize the data produced by these studies. In particular, stepwise regression algorithms based on p-values are prone to generate false positives and overfit data, potentially leading to unnecessarily complex control strategies. Many of the deficiencies of traditional stepwise regression can be alleviated by applying cross validation to stepwise regression algorithms, as well as Monte Carlo simulations to estimate model accuracy and predict CQA distributions. These methods can greatly enhance process understanding and assist in the selection of CPPs. A series of PC studies were performed in bioreactors to evaluate a process to produce a recombinant monoclonal antibody. The studies examined process parameters such as dissolved oxygen, pH, temperature, inoculation density, as well as cell density at two key process steps. The resulting data were analyzed using several Monte Carlo based methods. First, cross validation was used to determine model size and select parameters to be included in the model. Next, Monte Carlo cross validation was used to compare the accuracy of different models. Finally, simulated CQA profiles were generated to validate proposed ORs. This workflow provides greater process understanding based on a given PC data set and provides higher statistical confidence in both CPP selection and establishment of a control strategy.

Complete Excision of a Simple Dacryops Using Fibrin Sealant and Trypan Blue Mixture.

A 69-year-old woman presented to the oculofacial plastic service with a painless superotemporal subconjunctival mass in the OS. Over the past year, the lesion had been progressively enlarging, resulting in horizontal diplopia with lateral gaze. Visual acuity was within normal limits with no evidence of optic neuropathy. On examination, the lesion was tense, transilluminated, and was clinically consistent with a simple dacryops. Complete excision of the lesion was planned under local anesthesia with monitored care. To facilitate complete removal of the lesion, fibrinogen and a mixture of thrombin and trypan blue were injected to fill the cyst cavity. This blue-stained fibrin clot allowed for easy visualization of the border and ensured complete excision without collateral damage to surrounding normal tissue. Simple dacryops is often difficult to remove completely with its capsule intact and this technique allows for clear delineation of the cyst and preservation of epithelial integrity for complete and efficient removal.