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Abstract Objective To evaluate how pediatric indications for tonsillectomy or adenotonsillectomy relate to gender, race/ethnicity, and age. Methods Included consecutive pediatric patients who underwent tonsillectomy or adenotonsillectomy from a single tertiary academic institution between 2012 and 2019. Logistic regression analysis was used to measure association between the indication for tonsillectomy and the demographic variables gender, race/ethnicity, and age. Results Of the 1106 children included in this study, 53% were male and 47% were female. Half of the children were White, 40% were African American, 6% were Hispanic and 4% were other. The most common indication for surgery was upper airway obstruction alone (66%), followed by obstruction and infection (22%), and recurrent infections (12%). We found that male gender (OR 1.59, 95% CI 1.24–2.04), African American race (OR 2.76, 95% CI 2.08–3.65), and younger age were associated with greater odds of presenting with upper airway obstruction as the indication for tonsillectomy. Conversely, male gender (OR 0.63, 95% CI 0.44–0.92), African American race (OR 0.4, 95% CI 0.26–0.61), and younger age were associated with lower odds of presenting with recurrent infection as the indication for tonsillectomy. Conclusions Male gender, African American race, and young age are risk factors for tonsillar surgery due to airway obstruction. Female gender, White race, and older age are risk factors for tonsillar surgery due to recurrent throat infections. Level of Evidence 3

Abstract Objective We aimed to determine the rate of complications associated with autologous costal cartilage graft harvest for pediatric laryngotracheal reconstruction (LTR). Secondarily, we sought to identify risk factors associated with the harvest of autologous costal cartilage, as well as evaluate management strategies. Data Sources An electronic database search of Ovid MEDLINE, Ovid EMBASE, and PubMed was completed for articles pertaining to complications in autologous costal cartilage harvest for pediatric LTR. Review Methods This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) 2020 guidelines. The study characteristics, operative information, and patient demographics were collected. The data concerning postoperative complications, risk factors, and management strategies were collected and analyzed for patterns. Results A total of 31 manuscripts representing 745 patients were included for analysis. The reported donor site complications included pneumothorax (n = 13, 1.74%), pleural tear (n = 5, 0.67%), infection (n = 8, 1.07%), and scar‐related problems (n = 2, 0.26%). There were no reported cases of seroma, persistent pain, or chest wall deformity. Only five studies discussed the management of donor site complications, with intervention in 11 (39.28%) patients including chest tube drainage and steroid injection. Conclusion There is significant variability in the literature regarding complication rates in autologous costal cartilage harvest for pediatric LTR. The incidence of major postoperative complications is low and supports the use of autologous costal cartilage as graft material for pediatric LTR. Level of Evidence NA.

Recent advancements have established machine learning’s utility in predicting nonlinear fluid dynamics, with predictive accuracy being a central motivation for employing neural networks. However, the pattern recognition central to the networks function is equally valuable for enhancing our dynamical insight into the complex fluid dynamics. In this paper, a single-layer convolutional neural network (CNN) was trained to recognize three qualitatively different subsonic buffet flows (periodic, quasi-periodic and chaotic) over a high-incidence airfoil, and a near-perfect accuracy was obtained with only a small training dataset. The convolutional kernels and corresponding feature maps, developed by the model with no temporal information provided, identified large-scale coherent structures in agreement with those known to be associated with buffet flows. Sensitivity to hyperparameters including network architecture and convolutional kernel size was also explored. The coherent structures identified by these models enhance our dynamical understanding of subsonic buffet over high-incidence airfoils over a wide range of Reynolds numbers.

Abstract Introduction: The electronic health record (EHR) and patient portal are used increasingly for clinical research, including patient portal recruitment messaging (PPRM). Use of PPRM has grown rapidly; however, best practices are still developing. In this study, we examined the use of PPRM at our institution and conducted qualitative interviews among study teams and patients to understand experiences and preferences for PPRM. Methods: We identified study teams that sent PPRMs and patients that received PPRMs in a 60-day period. We characterized these studies and patients, in addition to the patients’ interactions with the PPRMs (e.g., viewed, responded). From these groups, we recruited study team members and patients for semi-structured interviews. A pragmatic qualitative inquiry framework was used by interviewers. Interviews were audio-recorded and analyzed using a rapid qualitative analysis exploratory approach. Results: Across ten studies, 35,037 PPRMs were sent, 33% were viewed, and 17% were responded to. Interaction rates varied across demographic groups. Six study team members completed interviews and described PPRM as an efficient and helpful recruitment method. Twenty-eight patients completed interviews. They were supportive of receiving PPRMs, particularly when the PPRM was relevant to their health. Patients indicated that providing more information in the PPRM would be helpful, in addition to options to set personalized preferences. Conclusions: PPRM is an efficient recruitment method for study teams and is acceptable to patients. Engagement with PPRMs varies across demographic groups, which should be considered during recruitment planning. Additional research is needed to evaluate and implement recommended changes by study teams and patients.

Abstract Objectives: To present a rare case of Eagle Syndrome in a pediatric patient, reminding the medical community to keep this diagnosis on their differential.

β-Apocarotenoids are eccentric cleavage products of carotenoids formed by chemical and enzymatic oxidations. They occur in foods containing carotenoids and thus might be directly absorbed from the diet. However, there is limited information about their intestinal absorption. The present research examined the kinetics of uptake and metabolism of β-apocarotenoids. Caco-2 cells were grown on 6-well plastic plates until a differentiated cell monolayer was achieved. β-Apocarotenoids were prepared in Tween 40 micelles, delivered to differentiated cells in serum-free medium, and incubated at 37°C for up to 8 h. There was rapid uptake of β-apo-8′-carotenal into cells, and β-apo-8′-carotenal was largely converted to β-apo-8′-carotenoic acid and a minor metabolite that we identified as 5,6-epoxy-β-apo-8′-carotenol. There was also rapid uptake of β-apo-10′-carotenal into cells, and β-apo-10′-carotenal was converted into a major metabolite identified as 5,6-epoxy-β-apo-10′-carotenol and a minor metabolite that is likely a dihydro-β-apo-10′-carotenol. Finally, there was rapid cellular uptake of β-apo-13-carotenone, and this compound was extensively degraded. These results suggest that dietary β-apocarotenals are extensively metabolized in intestinal cells via pathways similar to the metabolism of retinal. Thus, they are likely not absorbed directly from the diet.

Consumption of the tomato carotenoid, lycopene, has been associated with favorable health benefits. Some of lycopene's biological activity may be due to metabolites resulting from cleavage of the lycopene molecule. Because of their structural similarity to the retinoic acid receptor (RAR) antagonist, β-apo-13-carotenone, the “first half” putative oxidative cleavage products of the symmetrical lycopene have been synthesized. All transformations proceed in moderate to good yield and some with high stereochemical integrity allowing ready access to these otherwise difficult to obtain terpenoids. In particular, the methods described allow ready access to the trans isomers of citral (geranial) and pseudoionone, important flavor and fragrance compounds that are not readily available isomerically pure and are building blocks for many of the longer apolycopenoids. In addition, all of the apo-11, apo-13, and apo-15 lycopenals/lycopenones/lycopenoic acids have been prepared. These compounds have been evaluated for their effect on RAR-induced genes in cultured hepatoma cells and, much like β-apo-13-carotenone, the comparable apo-13-lycopenone and the apo-15-lycopenal behave as RAR antagonists. Furthermore, molecular modeling studies demonstrate that the apo-13-lycopenone efficiently docked into the ligand binding site of RARα. Finally, isothermal titration calorimetry studies reveal that apo-13-lycopenone acts as an antagonist of RAR by inhibiting coactivator recruitment to the receptor.

The xanthophylls, lutein and zeaxanthin, are dietary carotenoids that selectively accumulate in the macula of the eye providing protection against age-related macular degeneration. To reach the macula, carotenoids cross the retinal pigment epithelium (RPE). Xanthophylls and β-carotene mostly associate with HDL and LDL, respectively. HDL binds to cells via a scavenger receptor class B1 (SR-B1)-dependent mechanism, while LDL binds via the LDL receptor. Using an in-vitro, human RPE cell model (ARPE-19), we studied the mechanisms of carotenoid uptake into the RPE by evaluating kinetics of cell uptake when delivered in serum or isolated LDL or HDL. For lutein and β-carotene, LDL delivery resulted in the highest rates and extents of uptake. In contrast, HDL was more effective in delivering zeaxanthin and meso-zeaxanthin leading to the highest rates and extents of uptake of all four carotenoids. Inhibitors of SR-B1 suppressed zeaxanthin delivery via HDL. Results show a selective HDL-mediated uptake of zeaxanthin and meso-zeaxanthin via SR-B1 and a LDL-mediated uptake of lutein. This demonstrates a plausible mechanism for the selective accumulation of zeaxanthin greater than lutein and xanthophylls over β-carotene in the retina. We found no evidence of xanthophyll metabolism to apocarotenoids or lutein conversion to meso-zeaxanthin.

The growing use of analytics has increased the demand for more highly data literate graduates. Awareness of ambiguity in data has been suggested as a new data literacy skill. Here, we describe a student-centered semester-long project that can be used to teach this skill in an introductory analytics or database course. The project requires students to anticipate and collect survey data about themselves and their fellow students that can be used to predict student exam performance later in the course. We summarize relevant prior research on ambiguity, describe the project in which ambiguity is explained and applied, present a preliminary analysis of the lesson's impact on student awareness of ambiguity, and discuss implications and future research.

Vitamin A was recognized as an essential nutrient 100 years ago. In the 1930s, it became clear that dietary β-carotene was cleaved at its central double to yield vitamin A (retinal or β-apo-15′-carotenal). Thus a great deal of research has focused on the central cleavage of provitamin A carotenoids to form vitamin A (retinoids). The mechanisms of formation and the physiological role(s) of noncentral (eccentric) cleavage of both provitamin A carotenoids and nonprovitamin A carotenoids has been less clear. It is becoming apparent that the apocarotenoids exert unique biological activities themselves. These compounds are found in the diet and thus may be absorbed in the intestine, or they may form from enzymatic or nonenzymatic cleavage of the parent carotenoids. The mechanism of action of apocarotenoids in mammals is not fully worked out. However, as detailed in this review, they have profound effects on gene expression and work, at least in part, through the modulation of ligand-activated nuclear receptors. Understanding the interactions of apocarotenoids with other lipid-binding proteins, chaperones, and metabolizing enzymes will undoubtedly increase our understanding of the biological roles of these carotenoid metabolites.

Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11’,12’-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination.

The intestinal absorption and metabolism of β-carotene is of vital importance in humans, especially in populations that obtain the majority of their vitamin A from provitamin A carotenoids. MS has provided a better understanding of the absorption of β-carotene, the most potent provitamin A carotenoid, through the use of stable isotopes of β-carotene. We report here an HPLC-MS method that eliminates the need for complicated sample preparation and allows us to detect and quantify newly absorbed d8-β-carotene as well as its d4-retinyl ester metabolites in human plasma and chylomicron fractions. Both retinoids and β-carotene were recovered in a single simple extraction that did not involve saponification, thus allowing subsequent quantitation of individual fatty acyl esters of retinol. Separation of d8-β-carotene and its d4-retinyl ester metabolites was achieved using the same C30 reversed-phase liquid chromatography followed by mass spectrometry in selected ion monitoring and negative atmospheric pressure chemical ionization modes, respectively. Total time for the two successive runs was 30 min. This HPLC-MS method allowed us to quantify the absorption of intact d8-β-carotene as well as its extent of conversion to d4-retinyl esters in humans after consumption of a single 5 mg dose of d8-β-carotene.

The purpose of this study was to investigate the mechanisms by which carotenoids [xanthophylls vs. β-carotene(β-C)] are taken up by retinal pigment epithelial (RPE) cells. The human RPE cell line, ARPE-19, was used. When ARPE-19 cells were fully differentiated (7–9 weeks), the xanthophylls lutein (LUT) and zeaxanthin (ZEA) were taken up by cells to an extent 2-fold higher than β-C (P < 0.05). At 9 weeks, cellular uptakes were 1.6, 2.5, and 3.2%, respectively, for β-C, LUT, and ZEA. Similar extents were observed when carotenoids were delivered in either Tween 40 or “chylomicrons” produced by Caco-2 cells. Differentiated ARPE-19 cells did not exhibit any detectable β-C 15,15′-oxygenase activity or convert exogenous β-C into vitamin A. When using specific antibodies against the lipid transporters cluster determinant 36 (CD36) and scavenger receptor class B type I (SR-BI), cellular uptake of β-C and ZEA were significantly decreased (40–60%) with anti-SR-BI but not with anti-CD36. Small interfering RNA transfection for SR-BI led to marked knockdown of SR-BI protein expression (∼90%), which resulted in decreased β-C and ZEA uptakes by 51% and 87%, respectively. Thus, the present data show that RPE cells preferentially take up xanthophylls versus the carotene by a process that appears to be entirely SR-BI-dependent for ZEA and partly so for β-C. This mechanism may explain, in part, the preferential accumulation of xanthophylls in the macula of the retina.

The purpose of this study was to compare the mechanisms of intestinal retinol (ROL) and carotenoid transport. When differentiated Caco-2 cells were incubated with ROL for varying times, cellular ROL plateaued within 2 h, whereas retinyl ester (RE) formation increased continuously. ROL and RE efflux into basolateral medium (BM) increased linearly with time, ROL in the nonlipoprotein fraction and REs in chylomicrons (CMs). In contrast to carotenoids, ROL uptake was proportional to ROL concentration (0.5–110 μM). ROL efflux into BM occurred via two processes: a) a saturable process at low concentrations (

In presence of oleate and taurocholate, differentiated CaCo-2 cell monolayers on membranes were able to assemble and secrete chylomicrons. Under these conditions, both cellular uptake and secretion into chylomicrons of β-carotene (β-C) were curvilinear, time-dependent (2–16 h), saturable, and concentration-dependent (apparent Km of 7–10 μM) processes. Under linear concentration conditions at 16 h incubation, the extent of absorption of all-trans β-C was 11% (80% in chylomicrons), while those of 9-cis- and 13-cis-β-C were significantly lower (2–3%). The preferential uptake of the all-trans isomer was also shown in hepatic stellate HSC-T6 cells and in a cell-free system from rat liver (microsomes), but not in endothelial EAHY cells or U937 monocyte-macrophages. Moreover, extents of absorption of α-carotene (α-C), lutein (LUT), and lycopene (LYC) in CaCo-2 cells were 10%, 7%, and 2.5%, respectively. Marked carotenoid interactions were observed between LYC/β-C and β-C/α-C.The present results indicate that β-C conformation plays a major role in its intestinal absorption and that cis isomer discrimination is at the levels of cellular uptake and incorporation into chylomicrons. Moreover, the kinetics of cellular uptake and secretion of β-C, the inhibition of the intestinal absorption of one carotenoid by another, and the cellular specificity of isomer discrimination all suggest that carotenoid uptake by intestinal cells is a facilitated process.

Retinyl esters (RE) have been used extensively as markers to study chylomicron (CM) catabolism because they are secreted in the postprandial state with CM and do not exchange with other lipoproteins in the plasma. To understand the mechanism of secretion of RE by the intestine under the fasting and postprandial states, differentiated Caco-2 cells were supplemented with radiolabeled retinol under conditions that support or do not support CM secretion. We observed that these cells assimilate vitamin A by a rapid uptake mechanism. After uptake, cells store retinol in both esterified and unesterified forms. Under fasting conditions, cells do not secrete RE but secrete free retinol unassociated with lipoproteins. Under postprandial conditions, cells secrete significant amounts of RE only with CM. The secretion of RE with CM was independent of the rate of uptake of retinol and intracellular free and esterified retinol levels, and was absolutely dependent on the assembly and secretion of CM. The secretion of RE was correlated with the secretion of CM and not with the secretion of total apolipoprotein B. Inhibition of CM secretion by Pluronic L81 decreased the secretion of RE and did not result in their increased secretion with smaller lipoproteins. These data strongly suggest that RE secretion by the intestinal cells is a specific and regulated process that occurs in the postprandial state and is dependent on the assembly and secretion of CM. We propose that RE are added to CM during final stages of lipoprotein assembly and may serve as signposts for these steps. —Nayak, N., E. H. Harrison, and M. M. Hussain. Retinyl ester secretion by intestinal cells: a specific and regulated process dependent on assembly and secretion of chylomicrons.

Approximately 25% of postprandial retinoid is cleared from the circulation by extrahepatic tissues. Little is known about physiologic factors important to this uptake. We hypothesized that lipoprotein lipase (LpL) contributes to extrahepatic clearance of chylomicron vitamin A. To investigate this, [3H]retinyl ester-containing rat mesenteric chylomicrons were injected intravenously into induced mutant mice and nutritionally manipulated rats. The tissue sites of uptake of 3H label by wild type mice and LpL-null mice overexpressing human LpL in muscle indicate that LpL expression does influence accumulation of chylomicron retinoid. Skeletal muscle from mice overexpressing human LpL accumulated 1.7- to 2.4-fold more 3H label than wild type. Moreover, heart tissue from mice overexpresssing human LpL, but lacking mouse LpL, accumulated less than half of the 3H-label taken up by wild type heart. Fasting and heparin injection, two factors that increase LpL activity in skeletal muscle, increased uptake of chylomicron [3H] retinoid by rat skeletal muscle. Using [3H]retinyl palmitate and its non-hydrolyzable analog retinyl [14C]hexadecyl ether incorporated into Intralipid emulsions, the importance of retinyl ester hydrolysis in this process was assessed. We observed that 3H label was taken up to a greater extent than 14C label by rat skeletal muscle, suggesting that retinoid uptake requires hydrolysis. In summary, for each of our experiments, the level of lipoprotein lipase expression in skeletal muscle, heart, and/or adipose tissue influenced the amount of [3H]retinoid taken up from chylomicrons and/ or their remnants. —van Bennekum, A. M., Y. Kako, P. H. Weinstock, E. H. Harrison, R. J. Deckelbaum, I. J. Goldberg, and W. S. Blaner. Lipoprotein lipase expression level influences tissue clearance of chylomicron retinyl ester. J. Lipid Res. 1999. 40: 565–574.

Carotenoids and α-tocopherol are dietary, lipophilic antioxidants that may protect plasma lipoproteins from oxidation, a process believed to contribute to atherogenesis. Previous work demonstrated that after the Cu(II)-initiated oxidation of human low density lipoprotein (LDL) in vitro, carotenoids and α-tocopherol were destroyed before significant lipid peroxidation took place, and that α-tocopherol was destroyed at a much faster rate than were the carotenoids. Additionally, in vitro enrichment of LDL with β-carotene, but not with lutein or lycopene, inhibited LDL oxidation. In the present studies the impact of LDL carotenoid and α-tocopherol content on LDL oxidation by human endothelial cells (EaHy-1) in culture was assessed. LDL isolated from 11 individual donors was incubated at 0.25 mg protein/mL with EaHy-1 cells in Ham's F-10 medium for up to 48 h. Formation of lipid hydroperoxides was assessed by chemical analysis and the contents of lutein, β-cryptoxanthin, lycopene, β-carotene and α-tocopherol were determined by high performance liquid chromatography. The extent of lipid peroxidation correlated with the endogenous α-tocopherol content of the LDL but not with its content of carotenoids. As in the Cu(II)-initiated system, carotenoids and α-tocopherol were destroyed before significant peroxidation took place, but, in the cell-mediated system, α-tocopherol and the carotenoids were destroyed at comparable rates. Also, like the Cu(II)-initiated oxidation, enrichment of the LDL with β-carotene protected it from oxidation by the endothelial cells. However, enrichment with either lutein or lycopene actually enhanced the cell-mediated oxidation of the LDL. Thus, the specific content of carotenoids in low density lipoprotein (LDL) clearly modulates its susceptibility to oxidation, but individual carotenoids may either inhibit or promote LDL oxidation.— Dugas, T. R., D. W. Morel, and E. H. Harrison. Impact of LDL carotenoid and α-tocopherol content on LDL oxidation by endothelial cells in culture. J. Lipid Res. 1998. 39: 999–1007.

At the core of every teacher is a set of beliefs and knowledge regarding teaching and learning. As a teacher develops her expertise, curricular practices are refined and self-efficacy is enhanced. Teachers possess varying degrees of efficacy and perceptions that impact literacy instruction within their classrooms. Yet, often times they are mandated to teach in certain ways to achieve desirable student outcomes, even when they may not agree with the methods or processes wholeheartedly. The purpose of this study is to explore some of the issues that change teachers’ instructional practices in the classroom and to reveal some of the issues that influence as well as hinder instructional reform within that setting. This qualitative case study uses observations, interviews, and questionnaires to highlight teacher efficacy from four first-grade teachers. Testing data indicate students achieve both because of instruction and teachers’ willingness to implement the reading program with fidelity. Findings from this study can assist in setting up professional development, serving as a guide for providing warranted support for student learning and teacher knowledge, and fostering considerations for including teachers in the important stages regarding the planning and implementation of classroom literacy instruction.